Science.gov

Sample records for laboratory conditions similar

  1. Pathogenesis of Malaria and Clinically Similar Conditions

    PubMed Central

    Clark, Ian A.; Alleva, Lisa M.; Mills, Alison C.; Cowden, William B.

    2004-01-01

    There is now wide acceptance of the concept that the similarity between many acute infectious diseases, be they viral, bacterial, or parasitic in origin, is caused by the overproduction of inflammatory cytokines initiated when the organism interacts with the innate immune system. This is also true of certain noninfectious states, such as the tissue injury syndromes. This review discusses the historical origins of these ideas, which began with tumor necrosis factor (TNF) and spread from their origins in malaria research to other fields. As well the more established proinflammatory mediators, such as TNF, interleukin-1, and lymphotoxin, the roles of nitric oxide and carbon monoxide, which are chiefly inhibitory, are discussed. The established and potential roles of two more recently recognized contributors, overactivity of the enzyme poly(ADP-ribose) polymerase 1 (PARP-1) and the escape of high-mobility-group box 1 (HMGB1) protein from its normal location into the circulation, are also put in context. The pathogenesis of the disease caused by falciparum malaria is then considered in the light of what has been learned about the roles of these mediators in these other diseases, as well as in malaria itself. PMID:15258091

  2. Anonymous indexing of health conditions for a similarity measure.

    PubMed

    Song, Insu; Marsh, Nigel V

    2012-07-01

    A health social network is an online information service which facilitates information sharing between closely related members of a community with the same or a similar health condition. Over the years, many automated recommender systems have been developed for social networking in order to help users find their communities of interest. For health social networking, the ideal source of information for measuring similarities of patients is the medical information of the patients. However, it is not desirable that such sensitive and private information be shared over the Internet. This is also true for many other security sensitive domains. A new information-sharing scheme is developed where each patient is represented as a small number of (possibly disjoint) d-words (discriminant words) and the d-words are used to measure similarities between patients without revealing sensitive personal information. The d-words are simple words like "food,'' and thus do not contain identifiable personal information. This makes our method an effective one-way hashing of patient assessments for a similarity measure. The d-words can be easily shared on the Internet to find peers who might have similar health conditions.

  3. 42 CFR 493.1230 - Condition: General laboratory systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Condition: General laboratory systems. 493.1230... SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for Nonwaived Testing General Laboratory Systems § 493.1230 Condition: General laboratory systems. Each laboratory...

  4. 42 CFR 493.1230 - Condition: General laboratory systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Condition: General laboratory systems. 493.1230... SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for Nonwaived Testing General Laboratory Systems § 493.1230 Condition: General laboratory systems. Each laboratory...

  5. 42 CFR 493.1230 - Condition: General laboratory systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: General laboratory systems. 493.1230... SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for Nonwaived Testing General Laboratory Systems § 493.1230 Condition: General laboratory systems. Each laboratory...

  6. 42 CFR 493.1230 - Condition: General laboratory systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Condition: General laboratory systems. 493.1230... SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for Nonwaived Testing General Laboratory Systems § 493.1230 Condition: General laboratory systems. Each laboratory...

  7. 42 CFR 493.1230 - Condition: General laboratory systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Condition: General laboratory systems. 493.1230... SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for Nonwaived Testing General Laboratory Systems § 493.1230 Condition: General laboratory systems. Each laboratory...

  8. Conditional Granger causality and partitioned Granger causality: differences and similarities.

    PubMed

    Malekpour, Sheida; Sethares, William A

    2015-12-01

    Neural information modeling and analysis often requires a measurement of the mutual influence among many signals. A common technique is the conditional Granger causality (cGC) which measures the influence of one time series on another time series in the presence of a third. Geweke has translated this condition into the frequency domain and has explored the mathematical relationships between the time and frequency domain expressions. Chen has observed that in practice, the expressions may return (meaningless) negative numbers, and has proposed an alternative which is based on a partitioned matrix scheme, which we call partitioned Granger causality (pGC). There has been some confusion in the literature about the relationship between cGC and pGC; some authors treat them as essentially identical measures, while others have noted that some properties (such as the relationship between the time and frequency domain expressions) do not hold for the pGC. This paper presents a series of matrix equalities that simplify the calculation of the pGC. In this simplified expression, the essential differences and similarities between the cGC and the pGC become clear; in essence, the pGC is dependent on only a subset of the parameters in the model estimation, and the noise residuals (which are uncorrelated in the cGC) need not be uncorrelated in the pGC. The mathematical results are illustrated with a simulation, and the measures are applied to an EEG dataset.

  9. Similarity

    NASA Technical Reports Server (NTRS)

    Apostol, Tom M. (Editor)

    1990-01-01

    In this 'Project Mathematics! series, sponsored by the California Institute for Technology (CalTech), the mathematical concept of similarity is presented. he history of and real life applications are discussed using actual film footage and computer animation. Terms used and various concepts of size, shape, ratio, area, and volume are demonstrated. The similarity of polygons, solids, congruent triangles, internal ratios, perimeters, and line segments using the previous mentioned concepts are shown.

  10. 42 CFR 493.1441 - Condition: Laboratories performing high complexity testing; laboratory director.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... testing; laboratory director. 493.1441 Section 493.1441 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1441 Condition: Laboratories performing high complexity testing; laboratory director. The laboratory must have...

  11. 42 CFR 493.1403 - Condition: Laboratories performing moderate complexity testing; laboratory director.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Condition: Laboratories performing moderate complexity testing; laboratory director. 493.1403 Section 493.1403 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity...

  12. 42 CFR 493.1403 - Condition: Laboratories performing moderate complexity testing; laboratory director.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Condition: Laboratories performing moderate complexity testing; laboratory director. 493.1403 Section 493.1403 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity...

  13. 42 CFR 493.1403 - Condition: Laboratories performing moderate complexity testing; laboratory director.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Condition: Laboratories performing moderate complexity testing; laboratory director. 493.1403 Section 493.1403 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity...

  14. 42 CFR 493.1403 - Condition: Laboratories performing moderate complexity testing; laboratory director.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Condition: Laboratories performing moderate complexity testing; laboratory director. 493.1403 Section 493.1403 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity...

  15. 42 CFR 493.1403 - Condition: Laboratories performing moderate complexity testing; laboratory director.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Laboratories performing moderate complexity testing; laboratory director. 493.1403 Section 493.1403 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity...

  16. Composition and acidification of the culture medium influences chronological aging similarly in vineyard and laboratory yeast.

    PubMed

    Murakami, Christopher J; Wall, Valerie; Basisty, Nathan; Kaeberlein, Matt

    2011-01-01

    Chronological aging has been studied extensively in laboratory yeast by culturing cells into stationary phase in synthetic complete medium with 2% glucose as the carbon source. During this process, acidification of the culture medium occurs due to secretion of organic acids, including acetic acid, which limits survival of yeast cells. Dietary restriction or buffering the medium to pH 6 prevents acidification and increases chronological life span. Here we set out to determine whether these effects are specific to laboratory-derived yeast by testing the chronological aging properties of the vineyard yeast strain RM11. Similar to the laboratory strain BY4743 and its haploid derivatives, RM11 and its haploid derivatives displayed increased chronological life span from dietary restriction, buffering the pH of the culture medium, or aging in rich medium. RM11 and BY4743 also displayed generally similar aging and growth characteristics when cultured in a variety of different carbon sources. These data support the idea that mechanisms of chronological aging are similar in both the laboratory and vineyard strains.

  17. 42 CFR 493.1355 - Condition: Laboratories performing PPM procedures; laboratory director.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Condition: Laboratories performing PPM procedures; laboratory director. 493.1355 Section 493.1355 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY...

  18. 42 CFR 493.1355 - Condition: Laboratories performing PPM procedures; laboratory director.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Laboratories performing PPM procedures; laboratory director. 493.1355 Section 493.1355 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY...

  19. 42 CFR 493.1355 - Condition: Laboratories performing PPM procedures; laboratory director.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Condition: Laboratories performing PPM procedures; laboratory director. 493.1355 Section 493.1355 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY...

  20. 42 CFR 493.1355 - Condition: Laboratories performing PPM procedures; laboratory director.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Condition: Laboratories performing PPM procedures; laboratory director. 493.1355 Section 493.1355 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY...

  1. 42 CFR 493.1355 - Condition: Laboratories performing PPM procedures; laboratory director.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Condition: Laboratories performing PPM procedures; laboratory director. 493.1355 Section 493.1355 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY...

  2. On triatomines, cockroaches and haemolymphagy under laboratory conditions: new discoveries

    PubMed Central

    Durán, Pamela; Siñani, Edda; Depickère, Stéphanie

    2016-01-01

    For a long time, haematophagy was considered an obligate condition for triatomines (Hemiptera: Reduviidae) to complete their life cycle. Today, the ability to use haemolymphagy is suggested to represent an important survival strategy for some species, especially those in genus Belminus. As Eratyrus mucronatus and Triatoma boliviana are found with cockroaches in the Blaberinae subfamily in Bolivia, their developmental cycle from egg to adult under a “cockroach diet” was studied. The results suggested that having only cockroach haemolymph as a food source compromised development cycle completion in both species. Compared to a “mouse diet”, the cockroach diet increased: (i) the mortality at each nymphal instar; (ii) the number of feedings needed to molt; (iii) the volume of the maximum food intake; and (iv) the time needed to molt. In conclusion, haemolymph could effectively support survival in the field in both species. Nevertheless, under laboratory conditions, the use of haemolymphagy as a survival strategy in the first developmental stages of these species was not supported, as their mortality was very high. Finally, when Triatoma infestans, Rhodnius stali and Panstrongylus rufotuberculatus species were reared on a cockroach diet under similar conditions, all died rather than feeding on cockroaches. These results are discussed in the context of the ecology of each species. PMID:27706376

  3. On triatomines, cockroaches and haemolymphagy under laboratory conditions: new discoveries.

    PubMed

    Durán, Pamela; Siñani, Edda; Depickère, Stéphanie

    2016-10-01

    For a long time, haematophagy was considered an obligate condition for triatomines (Hemiptera: Reduviidae) to complete their life cycle. Today, the ability to use haemolymphagy is suggested to represent an important survival strategy for some species, especially those in genus Belminus. As Eratyrus mucronatus and Triatoma boliviana are found with cockroaches in the Blaberinae subfamily in Bolivia, their developmental cycle from egg to adult under a "cockroach diet" was studied. The results suggested that having only cockroach haemolymph as a food source compromised development cycle completion in both species. Compared to a "mouse diet", the cockroach diet increased: (i) the mortality at each nymphal instar; (ii) the number of feedings needed to molt; (iii) the volume of the maximum food intake; and (iv) the time needed to molt. In conclusion, haemolymph could effectively support survival in the field in both species. Nevertheless, under laboratory conditions, the use of haemolymphagy as a survival strategy in the first developmental stages of these species was not supported, as their mortality was very high. Finally, when Triatoma infestans, Rhodnius stali and Panstrongylus rufotuberculatus species were reared on a cockroach diet under similar conditions, all died rather than feeding on cockroaches. These results are discussed in the context of the ecology of each species.

  4. 29 CFR 1620.18 - Jobs performed under similar working conditions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 4 2014-07-01 2014-07-01 false Jobs performed under similar working conditions. 1620.18... THE EQUAL PAY ACT § 1620.18 Jobs performed under similar working conditions. (a) In general. In order for the equal pay standard to apply, the jobs are required to be performed under similar...

  5. 29 CFR 1620.18 - Jobs performed under similar working conditions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 4 2013-07-01 2013-07-01 false Jobs performed under similar working conditions. 1620.18... THE EQUAL PAY ACT § 1620.18 Jobs performed under similar working conditions. (a) In general. In order for the equal pay standard to apply, the jobs are required to be performed under similar...

  6. 29 CFR 1620.18 - Jobs performed under similar working conditions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Jobs performed under similar working conditions. 1620.18... THE EQUAL PAY ACT § 1620.18 Jobs performed under similar working conditions. (a) In general. In order for the equal pay standard to apply, the jobs are required to be performed under similar...

  7. 29 CFR 1620.18 - Jobs performed under similar working conditions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 4 2012-07-01 2012-07-01 false Jobs performed under similar working conditions. 1620.18... THE EQUAL PAY ACT § 1620.18 Jobs performed under similar working conditions. (a) In general. In order for the equal pay standard to apply, the jobs are required to be performed under similar...

  8. 29 CFR 1620.18 - Jobs performed under similar working conditions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 4 2011-07-01 2011-07-01 false Jobs performed under similar working conditions. 1620.18... THE EQUAL PAY ACT § 1620.18 Jobs performed under similar working conditions. (a) In general. In order for the equal pay standard to apply, the jobs are required to be performed under similar...

  9. Environmental monitoring programs vs Good Laboratory Practice (GLP) programs: differences and similarities.

    PubMed

    Bentley, R E

    1995-12-01

    Environmental monitoring and Good Laboratory Practice programs are similar when looked at empirically. Both address quality issues, human or environmental safety, and have set procedures to assure the concomitant results. However, when compared at the operational level, they can be best described as very different. Good Laboratory Practice programs deal basically with two governmental agencies and their divisions- the Environmental Protection Agency and Food and Drug Administration. These are administered from the federal level involving no state resources. These programs are objective driven with the procedures being defined in study plans, protocols, and standard operating procedures. The environmental monitoring testing programs deal with a profusion of federal legislation including CERCLA (also known as CLP), RCRA, CWA, CAA, SDWA, NPDES and others. These acts require analysis by specific procedures mandated by the statutes. States operate many of these programs and have been given the authority by the federal government. Many of the states require separate certifications to conduct these analyses. Environmental monitoring testing laboratories often must acquire multiple state certifications to participate in multiple state programs. This is not cost effective and often leads to conflicting requirements. Much of the direction for having a national certification program comes from problems associated with these state-operated programs.

  10. 42 CFR 493.1441 - Condition: Laboratories performing high complexity testing; laboratory director.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Condition: Laboratories performing high complexity testing; laboratory director. 493.1441 Section 493.1441 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION...

  11. 42 CFR 493.1441 - Condition: Laboratories performing high complexity testing; laboratory director.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Condition: Laboratories performing high complexity testing; laboratory director. 493.1441 Section 493.1441 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION...

  12. 42 CFR 493.1441 - Condition: Laboratories performing high complexity testing; laboratory director.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Condition: Laboratories performing high complexity testing; laboratory director. 493.1441 Section 493.1441 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION...

  13. 42 CFR 493.1441 - Condition: Laboratories performing high complexity testing; laboratory director.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Laboratories performing high complexity testing; laboratory director. 493.1441 Section 493.1441 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION...

  14. 42 CFR 494.130 - Condition: Laboratory services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Laboratory services. 494.130 Section 494.130 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION CONDITIONS FOR COVERAGE FOR END-STAGE RENAL DISEASE...

  15. 42 CFR 494.130 - Condition: Laboratory services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 5 2014-10-01 2014-10-01 false Condition: Laboratory services. 494.130 Section 494.130 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION CONDITIONS FOR COVERAGE FOR END-STAGE RENAL DISEASE...

  16. 42 CFR 494.130 - Condition: Laboratory services.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Condition: Laboratory services. 494.130 Section 494.130 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION CONDITIONS FOR COVERAGE FOR END-STAGE RENAL DISEASE...

  17. 42 CFR 494.130 - Condition: Laboratory services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Condition: Laboratory services. 494.130 Section 494.130 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION CONDITIONS FOR COVERAGE FOR END-STAGE RENAL DISEASE...

  18. 42 CFR 494.130 - Condition: Laboratory services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 5 2012-10-01 2012-10-01 false Condition: Laboratory services. 494.130 Section 494.130 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION CONDITIONS FOR COVERAGE FOR END-STAGE RENAL DISEASE...

  19. Extension of laboratory-measured soil spectra to field conditions

    NASA Technical Reports Server (NTRS)

    Stoner, E. R.; Baumgardner, M. F.; Weismiller, R. A.; Biehl, L. L.; Robinson, B. F.

    1982-01-01

    Spectral responses of two glaciated soils, Chalmers silty clay loam and Fincastle silt loam, formed under prairie grass and forest vegetation, respectively, were measured in the laboratory under controlled moisture equilibria using an Exotech Model 20C spectroradiometer to obtain spectral data in the laboratory under artificial illumination. The same spectroradiometer was used outdoors under solar illumination to obtain spectral response from dry and moistened field plots with and without corn residue cover, representing the two different soils. Results indicate that laboratory-measured spectra of moist soil are directly proportional to the spectral response of that same field-measured moist bare soil over the 0.52 micrometer to 1.75 micrometer wavelength range. The magnitudes of difference in spectral response between identically treated Chalmers and Fincastle soils are greatest in the 0.6 micrometers to 0.8 micrometer transition region between the visible and near infrared, regardless of field condition or laboratory preparation studied.

  20. Life cycle of Amblyomma integrum (Acari: Ixodidae) under laboratory conditions.

    PubMed

    Bandaranayaka, K O; Apanaskevich, D A; Rajakaruna, R S

    2016-07-01

    Amblyomma integrum is a hard tick infesting mainly buffalo and cattle and has been identified as an agent of human otoacariasis in Sri Lanka. Data on the life cycle pattern of A. integrum were collected by experimental infestation on New Zealand white rabbits under laboratory conditions. Wild-caught females laid 55-7389 eggs for 2-35 days after spending a latent period of 10-25 days. Egg incubation period was 31-105 days and the newly emerged larvae started feeding after 4-11 days. Larvae dropped off after feeding and they moulted into nymphs after 10-16 days. Nymphs actively fed on rabbits for 4-8 days and dropped off. Engorged nymphs took 11-25 days for moulting before emerging as adults. The male:female sex ratio of the adults moulted under laboratory conditions was 11:9. All the stages showed periodicity in engorgement and dropping off. The three-host life cycle was completed within 74-245 days with an average of 152.9 days. The mean Reproductive Efficiency Index (REI) and Reproductive Aptitude Index (RAI) were 3.6 and 1.1, respectively. Females hatched in the laboratory did not successfully feed on New Zealand white rabbits. The wild-caught females which fed on buffaloes had prolonged pre-oviposition and oviposition periods, low REI, low RAI and low eclosion under controlled laboratory conditions compared to other tick species. Although larva and nymphs of A. integrum successfully fed on New Zealand white rabbits under laboratory conditions, full life cycle was not completed because the adult females did not feed on rabbits.

  1. Conditioned context aversion learning in the laboratory mouse.

    PubMed

    Kislal, Sezen; Blizard, David A

    2016-12-01

    It is well known that pairing of large contextual changes with illness can cause conditioned context aversion in laboratory rats. The aim of present study was to develop a paradigm to study this phenomenon in laboratory mice, a species widely employed in neurobehavioral studies. Genetically heterogeneous mice, drinking from plastic bottles in the colony room, learned to avoid glass bottles after a single conditioning trial when drinking from these was paired with injections of lithium chloride. The aversion was independent of any difference in the taste of water in plastic vs. glass bottles. When the variation in the visual stimulus was less distinct, development of a strong aversion required two conditioning trials and was not retained as well. The results also showed that conditioned context aversion, just like conditioned taste aversion, could also be developed across a 30-minute CS-UCS delay. The fact that taste was not a factor in distinguishing drinking from glass and plastic water bottles raises the possibility that, contextual stimuli, not taste, may have been the CS when rats (in Garcia's original experiments) avoided drinking from plastic bottles that had been paired with radiation. The development of contextual aversion conditioning protocols for mice will enable the molecular resources available for this species to be exploited. Furthermore, representation of the CS by discrete rather than the multimodal CSs typically used in most studies on contextual conditioning offers more focus when considering its neuroanatomical basis.

  2. Seal formation in arid soil under natural and laboratory conditions

    NASA Astrophysics Data System (ADS)

    Sarah, Pariente; Sachs, Eyal

    2013-04-01

    Runoff is of considerable importance in the functioning of a desert ecosystem. The hydrological characteristics of runoff developing on arid soil under natural field conditions and those of runoff occurring in laboratory-controlled rain simulation experiments using the same type of soil were investigated. Runoff and erosion measurements were carried out in small plots (0.2-0.8 m2) on a south-facing hillslope in the northern Negev, Israel (90 mm ave. annual rainfall). Soil from the area near to the runoff plots was collected for the rain simulation experiments conducted in the laboratory. The soil was collected from 0-1 cm and 1-5 cm depths, and then placed within boxes (1.16 m long and 0.55 m wide) in the laboratory in the same order as they had been in the field. Representative surface stones were collected in the field and scattered randomly on the soil surface in the laboratory boxes. In some of the laboratory experiments soil, 5 cm in depth, was placed on a geotechnical sheet on a metal screen, while in other experiments, soil of 5 cm depth was placed on a Terzaghi filter. Rain simulator used had a rotating disk with a tilted nozzle to simulate raindrop size dispersion and kinetic energy of natural rain. The sprinkling intensity was set at a rate of 18 mm/hour. Soil crusts in the field were more stable than those created in the lab for two standard tests: Emerson - immersion test, and the 'single water drop' test. Whereas weak activity of microphytes was found in the field there was no such activity in the lab. The rain depth until runoff in the field was less than under laboratory conditions, while the sediment yield was greater in the field than in the laboratory (8.64 g/m2 versus 0.58 g/m2). The rain simulator experiments that had included a Terzaghi filter showed significantly higher final infiltration rate (7.5 mm/h versus 4.2 mm/h), shorter accumulated watering depth until stabilization of soil seal formation (100-200 mm versus 50 mm), and smaller

  3. Life cycle of Nosomma monstrosum (Acari: Ixodidae) under laboratory conditions.

    PubMed

    Bandaranayaka, K O; Apanaskevich, D A; Rajakaruna, R S

    2016-05-01

    Nosomma monstrosum (Nuttall & Warburton) is a hard tick infesting mainly buffalo and cattle in Sri Lanka. Biological data on the life cycle pattern of N. monstrosum were collected using experimental infestation on New Zealand white rabbits under laboratory conditions. The three-host life cycle was completed within 64-102 days. Eggs hatched after 20-29 days of incubation and the larvae hatched out started feeding which lasted for 2-4 days. After a moulting period of 8-11 days nymphs emerge and they actively fed for 2-4 days. Subsequently the nymphs took 15-18 days for moulting before emerging as adults. Freshly moulted females fed for 7-8 days and remained latent for 4-5 days before starting the oviposition. Females laid 3864-12,520 eggs for 11-17 days. The male: female sex ratio was 8:3 in the adults which were moulted under laboratory conditions. Strong positive correlations were found in female weight with number of eggs laid and REI. Females raised from the first generation of eggs had higher oviposition periods, higher REI, laid ten times more eggs, and lower pre-oviposition periods compared to those collected from the wild. When a suitable host is given, N. monstrosum could successfully complete its three-host life cycle under laboratory conditions.

  4. Laboratory experiments duplicate conditions in the Earth’s crust

    USGS Publications Warehouse

    Peselnick, L.; Dieterich, J.H.; Stewart, R.M.

    1974-01-01

    An experimental device that simulates conditions in the Earth's crust at depths of up to 30 kilometers has been constructed by geophysicists working at the U.S Geological Survey laboratories in Menlo Park, California. A high pressure "bomb" is being used to experimentally measure the velocity of seismic waves in different types of rock at various confining pressures and temperatures. The principal purpose of these measurements is to determine the elastic and non-elastic properties of rocks and minerals under conditions of high-pressure such as exist deep in the Earth's crust. 

  5. Laboratory simulations of NAT formation approaching stratospheric conditions

    NASA Technical Reports Server (NTRS)

    Marti, James; Mauersberger, Konrad

    1994-01-01

    Previous laboratory studies have established the stability conditions of nitric acid trihydrate (NAT), of which type 1 polar stratospheric cloud (PSC 1) particles are thought to be composed. However, NAT samples in lab studies were almost always formed under conditions very different from those of the stratosphere. In order to better understand the in situ growth of PSC 1 particle populations, samples of water and nitric acid were deposited under conditions of temperature and pressure which more closely approximate the polar stratosphere. The compositions of the solids, measured shortly after deposition, depended on the H2O:HNO3 ratio in the vapor from which the solids were condensed. Solids formed from vapor mixtures that approached stratospheric contained significantly less HNO3 than the 25 mol percent expected of NAT.

  6. Cable condition monitoring research activities at Sandia National Laboratories

    SciTech Connect

    Jacobus, M.J.; Zigler, G.L.; Bustard, L.D.

    1988-01-01

    Sandia National Laboratories is currently conducting long-term aging research on representative samples of nuclear power plant cables. The objectives of the program are to determine the suitability of these cables for extended life (beyond 40 year design basis) and to assess various cable condition monitoring techniques for predicting remaining cable life. The cables are being aged for long times at relatively mild exposure conditions with various condition monitoring techniques to be employed during the aging process. Following the aging process, the cables will be exposed to a sequential accident profile consisting of high dose rate irradiation followed by a simulated design basis loss-of-coolant accident (LOCA) steam exposure. 12 refs., 1 fig., 1 tab.

  7. Microbial surfactant-enhanced mineral oil recovery under laboratory conditions.

    PubMed

    Bordoloi, N K; Konwar, B K

    2008-05-01

    Microbial enhanced oil recovery (MEOR) is potentially useful to recover incremental oil from a reservoir being beyond primary and secondary recovery operations. Effort has been made to isolate and characterize natural biosurfactant produced by bacterial isolates collected from various oil fields of ONGC in Assam. Production of biosurfactant has been considered to be an effective major index for the purpose of enhanced oil recovery. On the basis of the index, four promising bacterial isolates: Pseudomonas aeruginosa (MTCC7815), P. aeruginosa (MTCC7814), P. aeruginosa (MTCC7812) and P. aeruginosa (MTCC8165) were selected for subsequent testing. Biosurfactant produced by the promising bacterial isolates have been found to be effective in the recovery of crude oil from saturated column under laboratory conditions. Two bacterial strains: P. aeruginosa (MTCC7815) and P. aeruginosa (MTCC7812) have been found to be the highest producer of biosurfactant. Tensiometer studies revealed that biosurfactants produced by these bacterial strains could reduce the surface tension (sigma) of the growth medium from 68 to 30 mN m(-1) after 96 h of growth. The bacterial biosurfactants were found to be functionally stable at varying pH (2.5-11) conditions and temperature of 100 degrees C. The treatment of biosurfactant containing, cell free culture broth in crude oil saturated sand pack column could release about 15% more crude oil at 90 degrees C than at room temperature and 10% more than at 70 degrees C under laboratory condition.

  8. Helium at White Dwarf Photospheric Conditions: Preliminary Laboratory Results

    NASA Astrophysics Data System (ADS)

    Schaeuble, M.; Falcon, R. E.; Gomez, T. A.; Winget, D. E.; Montgomery, M. H.; Bailey, J. E.

    2017-03-01

    We present preliminary results of an experimental study exploring helium at photospheric conditions of white dwarf stars. These data were collected at Sandia National Laboratories' Z-machine, the largest x-ray source on earth. Our helium results could have many applications ranging from validating current DB white dwarf model atmospheres to providing accurate He pressure shifts at varying temperatures and densities. In a much broader context, these helium data can be used to guide theoretical developments in new continuum-lowering models for two-electron atoms. We also discuss future applications of our updated experimental design, which enables us to sample a greater range of densities, temperatures, and gas compositions.

  9. [Biological aspects of Blatella germanica (Dictyoptera: Blattellidae) in laboratory conditions].

    PubMed

    Aguilera, L; Marquetti, M C; Fuentes, O; Navarro, A

    1996-01-01

    In a study of Blatella germanica (L) 1767 (Dictyoptera: Blattellidae) carried out in laboratory conditions, 6 nymphal stages were found in a period of 114.71 days, at 29 +/- 1 degrees C and 80-90% of relative humidity. Times of appearence and eclosion of every ovipositted ootheca, as well as the offspring average of each one, were determined. Females ovipositted up to 5 oothecas during their life. The maximum average of eggs found per ootheca was 29.22. The average longevity of males was lower that that of females (77.23 and 98.40 days, respectively) (t = 2.21; p < 0.05).

  10. Distinct stress conditions result in aggregation of proteins with similar properties

    PubMed Central

    Weids, Alan J.; Ibstedt, Sebastian; Tamás, Markus J.; Grant, Chris M.

    2016-01-01

    Protein aggregation is the abnormal association of proteins into larger aggregate structures which tend to be insoluble. This occurs during normal physiological conditions and in response to age or stress-induced protein misfolding and denaturation. In this present study we have defined the range of proteins that aggregate in yeast cells during normal growth and after exposure to stress conditions including an oxidative stress (hydrogen peroxide), a heavy metal stress (arsenite) and an amino acid analogue (azetidine-2-carboxylic acid). Our data indicate that these three stress conditions, which work by distinct mechanisms, promote the aggregation of similar types of proteins probably by lowering the threshold of protein aggregation. The proteins that aggregate during physiological conditions and stress share several features; however, stress conditions shift the criteria for protein aggregation propensity. This suggests that the proteins in aggregates are intrinsically aggregation-prone, rather than being proteins which are affected in a stress-specific manner. We additionally identified significant overlaps between stress aggregating yeast proteins and proteins that aggregate during ageing in yeast and C. elegans. We suggest that similar mechanisms may apply in disease- and non-disease settings and that the factors and components that control protein aggregation may be evolutionary conserved. PMID:27086931

  11. Distinct stress conditions result in aggregation of proteins with similar properties.

    PubMed

    Weids, Alan J; Ibstedt, Sebastian; Tamás, Markus J; Grant, Chris M

    2016-04-18

    Protein aggregation is the abnormal association of proteins into larger aggregate structures which tend to be insoluble. This occurs during normal physiological conditions and in response to age or stress-induced protein misfolding and denaturation. In this present study we have defined the range of proteins that aggregate in yeast cells during normal growth and after exposure to stress conditions including an oxidative stress (hydrogen peroxide), a heavy metal stress (arsenite) and an amino acid analogue (azetidine-2-carboxylic acid). Our data indicate that these three stress conditions, which work by distinct mechanisms, promote the aggregation of similar types of proteins probably by lowering the threshold of protein aggregation. The proteins that aggregate during physiological conditions and stress share several features; however, stress conditions shift the criteria for protein aggregation propensity. This suggests that the proteins in aggregates are intrinsically aggregation-prone, rather than being proteins which are affected in a stress-specific manner. We additionally identified significant overlaps between stress aggregating yeast proteins and proteins that aggregate during ageing in yeast and C. elegans. We suggest that similar mechanisms may apply in disease- and non-disease settings and that the factors and components that control protein aggregation may be evolutionary conserved.

  12. Observed turbulence characteristics in unstable conditions over the city of Tehran based on similarity theory

    NASA Astrophysics Data System (ADS)

    Pegahfar, N.; Zawar-Reza, P.

    2016-10-01

    In a previous study, applicability of Monin-Obukhov similarity theory (MOST) was established for stable and relatively neutral conditions for Tehran, based on local scaling approach. This paper extends the application of MOST to unstable conditions for Tehran using SODAR data and five 2-D sonic anemometers. Normalized standard deviations of three components of wind velocity (σ_{u, v, w} /u_{*} , u_{*} is friction velocity) as functions of ζ = (z - zd )/Λ stability parameter (where Λ is the local Obukhov length, z is the height of measurement and z_d is the zero-plane displacement height) have been computed and analyzed at various levels. Only the parameters measured at 105 m height provided sufficient accuracy for MOST evaluation and also reliable universal similarity relations, while those at the lower heights (45 and 75 m) did not match MOST. Near zero dependence of σ_{ w} /u_{*} on ζ motivated further investigation using convective velocity scale and also another stability parameter (defined using mixed-layer height). Applying the second scaling parameters leads to more suitable similarity functions. For the present research, we demonstrate that under unstable conditions, normalized values of σ_{u, v, w} could be collapsed into the similarity expressions, but are highly dependent on proper selection of scale and vertical position. So for the case of Tehran, transformation from one kind of similarity scale to another one is possible, as suggested by Hu and Zhang (Sci Atmos Sin 17:10-20, 1993), with the provision that it only works for certain focused variables and vertical position. In addition, we show significant differences in empirical constants between Tehran and the values reported for the other cities in the literature (from the other surface types). This is most likely due to the local effects of the underlying surface (both urban area and topographical features) in Tehran.

  13. 42 CFR 493.1415 - Condition: Laboratories performing moderate complexity testing; clinical consultant.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... complexity testing; clinical consultant. 493.1415 Section 493.1415 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1415 Condition: Laboratories performing moderate complexity testing; clinical consultant....

  14. 42 CFR 493.1421 - Condition: Laboratories performing moderate complexity testing; testing personnel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... complexity testing; testing personnel. 493.1421 Section 493.1421 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1421 Condition: Laboratories performing moderate complexity testing; testing personnel....

  15. 42 CFR 493.1409 - Condition: Laboratories performing moderate complexity testing; technical consultant.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... complexity testing; technical consultant. 493.1409 Section 493.1409 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1409 Condition: Laboratories performing moderate complexity testing; technical consultant....

  16. 42 CFR 493.1421 - Condition: Laboratories performing moderate complexity testing; testing personnel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... complexity testing; testing personnel. 493.1421 Section 493.1421 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1421 Condition: Laboratories performing moderate complexity testing; testing personnel....

  17. 42 CFR 493.1409 - Condition: Laboratories performing moderate complexity testing; technical consultant.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... complexity testing; technical consultant. 493.1409 Section 493.1409 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1409 Condition: Laboratories performing moderate complexity testing; technical consultant....

  18. 42 CFR 493.1415 - Condition: Laboratories performing moderate complexity testing; clinical consultant.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... complexity testing; clinical consultant. 493.1415 Section 493.1415 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity Testing § 493.1415 Condition: Laboratories performing moderate complexity testing; clinical consultant....

  19. Reproduction of Omalonyx matheroni (Gastropoda: Succineidae) under laboratory conditions.

    PubMed

    Montresor, Lângia; Teixeira, Ana; Paglia, Adriano; Vidigal, Teofânia

    2012-06-01

    The life histories of succineids have received relatively little attention. To evaluate life history characteristics of Omalonyx matheroni, we studied a Brazilian population (Reserva Particular do Patrimônio Natural Feliciano Miguel Abdala, in Caratinga, Minas Gerais, Brazil) under laboratory conditions. The aims of the present study were (1) to describe in detail an appropriate rearing method; (2) to investigate the effects of different temperature and photoperiod conditions; and (3) to assess the effects of self and cross-fertilization on the reproductive biology of these mollusks. We studied the oviposition site, the time to sexual maturity and the influences of photoperiod and temperature on reproductive parameters of O. matheroni reared under laboratory conditions. We tested three combinations of temperature and photoperiod, designated A, B and C (A: 25degreeC, 24 hours of light; B: environmental conditions of temperature and photoperiod, characterized as follows: average maximum temperature=27.1 degreeC, average minimum temperature=18.3 degreeC, average day length=12.06 hours; and C: 25 degreeC, zero hours of light) and two rearing densities (I: isolated and G: grouped) on reproductive parameters (number of eggs per egg mass, number of unviable eggs per mass, egg mass incubation period, and duration of the hatching period). A total of 186 individuals and 565 egg masses were studied. Data were analyzed by Student's t-test, two-way ANOVA and Chi-Square test. Eight generations were produced (March/2004-March/2006), from 35 field specimens, 91% of 3 197 eggs hatched. The time to sexual maturity was approximately three months for individuals reared in groups or in isolation (Student's t-test: t=1.41, df=31, p=0.16); however, they differed significantly in weight (Student's t-test: t=3.6, df=31, p<0.001). Regarding the influences of temperature and photoperiod on reproductive parameters, under natural environmental conditions, individuals produced a greater number

  20. Laboratory-based electrical conductivity at Martian mantle conditions

    NASA Astrophysics Data System (ADS)

    Verhoeven, Olivier; Vacher, Pierre

    2016-12-01

    Information on temperature and composition of planetary mantles can be obtained from electrical conductivity profiles derived from induced magnetic field analysis. This requires a modeling of the conductivity for each mineral phase at conditions relevant to planetary interiors. Interpretation of iron-rich Martian mantle conductivity profile therefore requires a careful modeling of the conductivity of iron-bearing minerals. In this paper, we show that conduction mechanism called small polaron is the dominant conduction mechanism at temperature, water and iron content conditions relevant to Mars mantle. We then review the different measurements performed on mineral phases with various iron content. We show that, for all measurements of mineral conductivity reported so far, the effect of iron content on the activation energy governing the exponential decrease in the Arrhenius law can be modeled as the cubic square root of the iron content. We recast all laboratory results on a common generalized Arrhenius law for iron-bearing minerals, anchored on Earth's mantle values. We then use this modeling to compute a new synthetic profile of Martian mantle electrical conductivity. This new profile matches perfectly, in the depth range [100,1000] km, the electrical conductivity profile recently derived from the study of Mars Global Surveyor magnetic field measurements.

  1. Amygdaloid lesions produced similar contextual fear conditioning disruption in the Carioca high- and low-conditioned freezing rats.

    PubMed

    de Castro Gomes, Vitor; Landeira-Fernandez, J

    2008-10-03

    Rats selectively bred for high or low levels of emotionality represent an important and powerful tool to investigate the role of genetic variables in the occurrence of different anxiety disorders. In the present study, albino rats were selectively bred for differences in defensive freezing behavior in response to contextual cues previously associated with footshock, an animal model of general anxiety disorder. The results indicate that these two new lines of rats, which we refer to as Carioca High-Freezing (CHF) and Carioca Low-Freezing (CLF), show a reliable difference in conditioned freezing after three generations of selection. CHF and CLF rats did not present any differences during baseline or post-shock periods. Males from both lines consistently exhibit more conditioned freezing to contextual cues than females. A second experiment used male rats from the fourth generation to investigate the participation of the amygdala during contextual fear conditioning in the CHF and CLF lines. The results indicate that post-training amygdaloid electrolytic lesions lead to similar disruptions in conditioned freezing behavior in both animal lines.

  2. Growth of Heterostegina depressa under natural and laboratory conditions

    PubMed Central

    Eder, Wolfgang; Briguglio, Antonino; Hohenegger, Johann

    2016-01-01

    The use of micro-computed tomography (μCT) provides a unique opportunity to look inside the shells of larger benthic foraminifera to investigate their structure by measuring linear and volumetric parameters. For this study, gamonts/schizonts and agamonts of the species Heterostegina depressa d'Orbigny were examined by μCT; each single chamber's volume was digitally measured. This approach enables cell growth to be recognised in terms of chamber volume sequence, which progressively increases until reproduction occurs. This sequence represents the ontogeny of the foraminiferal cell and has been used here to investigate controlling factors potentially affecting the process of chamber formation. This is manifested as instantaneous or periodic deviations of the realised chamber volumes derived from modelled growth functions. The results obtained on naturally grown specimens show oscillations in chamber volumes which can be modelled by sums of sinusoidal functions. A set of functions with similar periods in all investigated specimens points to lunar and tidal cycles. To determine whether such cyclic signals are genuine and not the effects of a theoretical model, the same analysis was conducted on specimens held in a closed laboratory facility, as they should not be affected by natural environmental effects. Surprisingly, similar cyclicities were observed in such samples. However, a solely genetic origin of these cycles couldn't be verified either. Therefore, detailed analysis on the phase equality of these growth oscillations have been done. This approach is pivotal for proving that the oscillatory patterns discovered in LBF are indeed genuine signals, and on how chamber growth might be influenced by tidal currents or lunar months. PMID:28100933

  3. Verification of the karst flow model under laboratory controlled conditions

    NASA Astrophysics Data System (ADS)

    Gotovac, Hrvoje; Andric, Ivo; Malenica, Luka; Srzic, Veljko

    2016-04-01

    Karst aquifers are very important groundwater resources around the world as well as in coastal part of Croatia. They consist of extremely complex structure defining by slow and laminar porous medium and small fissures and usually fast turbulent conduits/karst channels. Except simple lumped hydrological models that ignore high karst heterogeneity, full hydraulic (distributive) models have been developed exclusively by conventional finite element and finite volume elements considering complete karst heterogeneity structure that improves our understanding of complex processes in karst. Groundwater flow modeling in complex karst aquifers are faced by many difficulties such as a lack of heterogeneity knowledge (especially conduits), resolution of different spatial/temporal scales, connectivity between matrix and conduits, setting of appropriate boundary conditions and many others. Particular problem of karst flow modeling is verification of distributive models under real aquifer conditions due to lack of above-mentioned information. Therefore, we will show here possibility to verify karst flow models under the laboratory controlled conditions. Special 3-D karst flow model (5.6*2.6*2 m) consists of concrete construction, rainfall platform, 74 piezometers, 2 reservoirs and other supply equipment. Model is filled by fine sand (3-D porous matrix) and drainage plastic pipes (1-D conduits). This model enables knowledge of full heterogeneity structure including position of different sand layers as well as conduits location and geometry. Moreover, we know geometry of conduits perforation that enable analysis of interaction between matrix and conduits. In addition, pressure and precipitation distribution and discharge flow rates from both phases can be measured very accurately. These possibilities are not present in real sites what this model makes much more useful for karst flow modeling. Many experiments were performed under different controlled conditions such as different

  4. Development cycle of Panstrongylus rufotuberculatus (Hemiptera: Reduviidae) under laboratory conditions.

    PubMed

    Wolff, Marta; Cuartas, Eliana; Velásquez, Carlos; Jaramillo, Nicolás

    2004-11-01

    Determinant aspects of the development cycle of Panstrongylus rufotuberculatus (Champion, 1899) were evaluated under laboratory conditions. Fertility, duration of life cycle, mortality rate, feeding time, defecation time, thermal reaction time to food source, and volume of blood ingested were studied. From an initial cohort of fifth instars, nine adult pairs were formed, the females of which oviposited 2,338 eggs over 231 d. The eclosion rate was 84.4%; female and male progeny lived 223.56 (14.41) and 180.78 (14.41) d, respectively. The average total life cycle of immature stages (138.82+/-51.42 d) was distributed as egg, 24.22+/-0.42 d; nymph I, 18.94+/-5.15 d; nymph II, 15.80+/-3.29 d; nymph III, 16.55+/-4.36 d; nymph IV, 25.50+/-7.32 d; and nymph V, 36.71+/-2.75 d. Given these values, 2.6 generations per year are possible. Because of its longevity, rapid response to the presence of a host, large volume of blood ingested, and frequent defecation during feeding, this species constitutes a potentially important vector of Chagas' disease in nonendemic rural areas.

  5. Asiatic cotton can generate similar economic benefits to Bt cotton under rainfed conditions.

    PubMed

    Romeu-Dalmau, Carla; Bonsall, Michael B; Willis, Katherine J; Dolan, Liam

    2015-06-01

    American cotton (Gossypium hirsutum L.), transformed with Bacillus thuringiensis Cry genes (Bt G. hirsutum) that confer resistance to lepidopteran pests, is extensively cultivated worldwide. In India, transgenic Bt G. hirsutum was commercially released in 2002 and by 2014 95% of farmers had adopted Bt G. hirsutum(1). The economic benefits of Bt G. hirsutum over non-Bt G. hirsutum are well documented and include increase in yields, increase in farmers' net revenue and reduction in pesticide application against lepidopteran pests(2-9). However, it is unclear to what extent irrigation influences the performance of Bt G. hirsutum on smallholder farming in India, and if, in the absence of irrigation, growing Bt G. hirsutum provides greater economic benefits for Indian smallholder farmers compared with growing the Asiatic cotton Gossypium arboreum L. Here, we compare the economic impact of growing Bt G. hirsutum with growing G. arboreum under rainfed conditions in the Indian state of Maharashtra, and show that G. arboreum can generate similar net revenue, and thus similar economic benefits for smallholder farmers compared with growing Bt G. hirsutum. We also compare the economic impact of growing Bt G. hirsutum under rainfed conditions with growing Bt G. hirsutum under irrigated conditions and show that even though Bt G. hirsutum yields increase with irrigation, the net revenue does not significantly increase because farmers using irrigation spend significantly more than farmers growing Bt G. hirsutum without irrigation. We conclude that our data provide a broader insight into how socio-economic data needs to be incorporated into agro-ecological data when planning strategies to improve cotton farming in India.

  6. Hoxb8 conditionally immortalised macrophage lines model inflammatory monocytic cells with important similarity to dendritic cells.

    PubMed

    Rosas, Marcela; Osorio, Fabiola; Robinson, Matthew J; Davies, Luke C; Dierkes, Nicola; Jones, Simon A; Reis e Sousa, Caetano; Taylor, Philip R

    2011-02-01

    We have examined the potential to generate bona fide macrophages (MØ) from conditionally immortalised murine bone marrow precursors. MØ can be derived from Hoxb8 conditionally immortalised macrophage precursor cell lines (MØP) using either M-CSF or GM-CSF. When differentiated in GM-CSF (GM-MØP) the resultant cells resemble GM-CSF bone marrow-derived dendritic cells (BMDC) in morphological phenotype, antigen phenotype and functional responses to microbial stimuli. In spite of this high similarity between the two cell types and the ability of GM-MØP to effectively present antigen to a T-cell hybridoma, these cells are comparatively poor at priming the expansion of IFN-γ responses from naïve CD4(+) T cells. The generation of MØP from transgenic or genetically aberrant mice provides an excellent opportunity to study the inflammatory role of GM-MØP, and reduces the need for mouse colonies in many studies. Hence differentiation of conditionally immortalised MØPs in GM-CSF represents a unique in vitro model of inflammatory monocyte-like cells, with important differences from bone marrow-derived dendritic cells, which will facilitate functional studies relating to the many 'sub-phenotypes' of inflammatory monocytes.

  7. Understanding Nutrient Processing Under Similar Hydrologic Conditions Along a River Continuum

    NASA Astrophysics Data System (ADS)

    Garayburu-Caruso, V. A.; Mortensen, J.; Van Horn, D. J.; Gonzalez-Pinzon, R.

    2015-12-01

    Eutrophication is one of the main causes of water impairment across the US. The fate of nutrients in streams is typically described by the dynamic coupling of physical processes and biochemical processes. However, isolating each of these processes and determining its contribution to the whole system is challenging due to the complexity of the physical, chemical and biological domains. We conducted column experiments seeking to understand nutrient processing in shallow sediment-water interactions along representative sites of the Jemez River-Rio Grande continuum (eight stream orders), in New Mexico (USA). For each stream order, we used a set of 6 columns packed with 3 different sediments, i.e., Silica Cone Density Sand ASTM D 1556 (0.075-2.00 mm), gravel (> 2mm) and native sediments from each site. We incubated the sediments for three months and performed tracer experiments in the laboratory under identical flow conditions, seeking to normalize the physical processes along the river continuum. We added a short-term pulse injection of NO3, resazurin and NaCl to each column and determined metabolism and NO3 processing using the Tracer Additions for Spiraling Curve Characterization method (TASCC). Our methods allowed us to study how changes in bacterial communities and sediment composition along the river continuum define nutrient processing.

  8. Morphometric changes of Triatoma flavida Neiva, 1911 (Hemiptera:Triatominae) in the transition from sylvatic to laboratory conditions.

    PubMed

    Rodríguez Rodríguez, Jinnay; Fuentes González, Omar; Nodarse, Jorge Fraga; Monzote Fidalgo, Lianet; Dujardin, Jean-Pierre

    2007-01-01

    The one-generational metric changes occurring in Triatoma flavida (Hemiptera: Triatominae) when carried from its wild habitat (caves) to laboratory, were examined using traditional morphometric techniques. As for other species of Triatoma, Rhodnius or Panstrongylus studied in similar conditions, a significant reduction of head, thorax and wing size was observed. Sexual dimorphism of the wings, while present in the wild sample, was not detected anymore in the laboratory individuals. Biological significance and epidemiological importance are discussed.

  9. Comparative bionomics of four populations of Meccus longipennis (Hemiptera: Reduviidae: Triatominae) under laboratory conditions.

    PubMed

    Martínez-Ibarra, José Alejandro; Nogueda-Torres, Benjamín; Licón-Trillo, Ángel; Villagrán-Herrera, María Elena; de Diego-Cabrera, José Antonio; Montañez-Valdez, Oziel Dante; Rocha-Chávez, Gonzalo

    2013-04-01

    The values of biological parameters related to the life cycles of four populations of Meccus longipennis (Reduviidae: Triatominae) were evaluated. Cohorts of each of the four studied populations from different geographical areas of Mexico were maintained under similar laboratory conditions and then compared. The population from El Saucito de Araujo was different from the other three studied populations, which could help explain the secondary importance of M. longipennis in the state of Chihuahua. This paper also supports the proposition that biological traits are important criteria for determining relationships between populations.

  10. Comparative bionomics of four populations of Meccus longipennis (Hemiptera: Reduviidae: Triatominae) under laboratory conditions

    PubMed Central

    Martínez-Ibarra, José Alejandro; Nogueda-Torres, Benjamín; Licón-Trillo, Ángel; Villagrán-Herrera, María Elena; de Diego-Cabrera, José Antonio; Montañez-Valdez, Oziel Dante; Rocha-Chávez, Gonzalo

    2013-01-01

    The values of biological parameters related to the life cycles of four populations of Meccus longipennis (Reduviidae: Triatominae) were evaluated. Cohorts of each of the four studied populations from different geographical areas of Mexico were maintained under similar laboratory conditions and then compared. The population from El Saucito de Araujo was different from the other three studied populations, which could help explain the secondary importance of M. longipennis in the state of Chihuahua. This paper also supports the proposition that biological traits are important criteria for determining relationships between populations. PMID:23579806

  11. DO TIE LABORATORY BASED METHODS REALLY REFLECT FIELD CONDITIONS

    EPA Science Inventory

    Sediment Toxicity Identification and Evaluation (TIE) methods have been developed for both interstitial waters and whole sediments. These relatively simple laboratory methods are designed to identify specific toxicants or classes of toxicants in sediments; however, the question ...

  12. The Design of Research Laboratories. Part I: A General Assessment. Part II: Air Conditioning and Conditioned Rooms.

    ERIC Educational Resources Information Center

    Legget, R. F.; Hutcheon, N. B.

    Design factors in the planning of research laboratories are described which include--(1) location, (2) future expansion, (3) internal flexibility, (4) provision of services, (5) laboratory furnishing, (6) internal traffic, (7) space requirements, and (8) building costs. A second part discusses air-conditioning and conditioned rooms--(1)…

  13. 42 CFR 493.1481 - Condition: Laboratories performing high complexity testing; cytotechnologist.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... testing; cytotechnologist. 493.1481 Section 493.1481 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1481 Condition: Laboratories performing high complexity testing; cytotechnologist. For the subspecialty...

  14. 42 CFR 493.1481 - Condition: Laboratories performing high complexity testing; cytotechnologist.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... testing; cytotechnologist. 493.1481 Section 493.1481 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1481 Condition: Laboratories performing high complexity testing; cytotechnologist. For the subspecialty...

  15. Comparison of meat quality between eland (Taurotragus oryx) and cattle (Bos taurus) raised under similar conditions.

    PubMed

    Bartoň, Luděk; Bureš, Daniel; Kotrba, Radim; Sales, James

    2014-01-01

    Physical, chemical and sensory characteristics of meat were compared between non-domestic eland (Taurotragus oryx) bulls (n=6) and domestic Fleckvieh (Bos taurus) bulls (n=6) which were finished under controlled conditions of feeding and management. Musculus longissimus lumborum from eland were darker and less yellow in colour, with a higher pH24 and lower contents of intramuscular fat and total collagen, compared to cattle. Contents (mg/100 g muscle tissue) and proportions (g/100 g of FA determined) of SFA and MUFA were higher (P<0.01) in cattle. Although the proportion of total PUFA were higher (P<0.001) in eland, contents of PUFA were similar between species. Meat from cattle was consistently scored higher (P<0.05) for sensory texture characteristics, juiciness, flavour, and overall acceptance. We concluded that bulls of eland provided low-fat meat with a beneficial fatty acid composition from a human nutrition perspective, but with lower sensory scores, compared to bull beef.

  16. Exposure to tebuconazol in rice field and laboratory conditions induces oxidative stress in carp (Cyprinus carpio).

    PubMed

    Toni, Cândida; Loro, Vania Lucia; Santi, Adriana; de Menezes, Charlene Cavalheiro; Cattaneo, Roberta; Clasen, Bárbara Estevão; Zanella, Renato

    2011-01-01

    Pesticides can have an effect on the biochemical and physiological functions of living organisms. The changes seen in fish and their response to pesticides can be used as an example for vertebrate toxicity. In this study, carp fish (Cyprinus carpio) were exposed to different concentrations of tebuconazol fungicide, by rice field (31.95 μg/L) and laboratory (33.47 and 36.23 μg/L) conditional testing, during a 7 day period. Parameters such thiobarbituric acid-reactive substance levels (TBARS), protein carbonyl, catalase, glutathione S-transferase and acetylcholinesterase activities were studied, using the liver, brain and white muscle of the fish. The field experiment showed that the TBARS levels were increased in all the analyzed tissues. Similarly, the protein carbonyl of the liver and the brain AChE activity increased after 7 days. The laboratory experiment demonstrated that the TBARS levels in the liver were increased in both of the concentration tests. TBARS levels in the muscle increased only by the lowest test concentration. On the other hand, the protein carbonyl was increased only by the highest concentration. The results indicate that the tebuconazol exposure from the field and laboratory conditions directly affected the health of the fish, showing the occurrence of oxidative stress.

  17. 19 CFR 113.67 - Commercial gauger and commercial laboratory bond conditions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Commercial gauger and commercial laboratory bond... SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS BONDS Customs Bond Conditions § 113.67 Commercial gauger and commercial laboratory bond conditions. Commercial Gauger Bond Conditions (a) Commercial gauger...

  18. 19 CFR 113.67 - Commercial gauger and commercial laboratory bond conditions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 1 2011-04-01 2011-04-01 false Commercial gauger and commercial laboratory bond... SECURITY; DEPARTMENT OF THE TREASURY CUSTOMS BONDS Customs Bond Conditions § 113.67 Commercial gauger and commercial laboratory bond conditions. Commercial Gauger Bond Conditions (a) Commercial gauger...

  19. Daily rhythmicity and hibernation in the Anatolian ground squirrel under natural and laboratory conditions.

    PubMed

    Kart Gür, Mutlu; Refinetti, Roberto; Gür, Hakan

    2009-02-01

    We studied daily rhythmicity of body temperature (T(b)) before and during hibernation in Anatolian ground squirrels (Spermophilus xanthoprymnus) under natural and laboratory conditions using surgically implanted temperature loggers. Under both conditions, robust daily T(b) rhythmicity with parameters comparable to those of other ground squirrel species was observed before but not during hibernation. Euthermic animals had robust daily T(b) rhythms with a mean of 37.0 degrees C and a range of excursion of approximately 4 degrees C. No T(b) rhythm was detected during torpor bouts, either because T(b) rhythmicity was absent or because the daily range of excursion was smaller than 0.2 degrees C. The general patterns of hibernation that we observed in Anatolian ground squirrels were similar to those previously observed by other investigators in other species of ground squirrels.

  20. Exploring the nature of collisionless shocks under laboratory conditions

    PubMed Central

    Stockem, A.; Fiuza, F.; Bret, A.; Fonseca, R. A.; Silva, L. O.

    2014-01-01

    Collisionless shocks are pervasive in astrophysics and they are critical to understand cosmic ray acceleration. Laboratory experiments with intense lasers are now opening the way to explore and characterise the underlying microphysics, which determine the acceleration process of collisionless shocks. We determine the shock character – electrostatic or electromagnetic – based on the stability of electrostatic shocks to transverse electromagnetic fluctuations as a function of the electron temperature and flow velocity of the plasma components, and we compare the analytical model with particle-in-cell simulations. By making the connection with the laser parameters driving the plasma flows, we demonstrate that shocks with different and distinct underlying microphysics can be explored in the laboratory with state-of-the-art laser systems. PMID:24488212

  1. [Life table for Selenothrips rubrocinctus (Thripidae: Panchaetothripinae) under laboratory conditions].

    PubMed

    Soto-Rodriguez, Gerardo A; Retana-Salazar, Axel P

    2005-01-01

    The tropical thrip Selenothrips rubrocinctus Giard is a polyphagous species sometimes found in commercially important crops that include cocoa and cotton. Laboratory data from specimens collected in Psidium friedrichsthalianum trees in Costa Rica were used to prepare a life table. There was a high mortality in the egg (72.5%) and larva II (18.4%) stages. On leaves, inmature stages presented subvascular distribution and pupae presented submarginal distribution.

  2. 42 CFR 493.1447 - Condition: Laboratories performing high complexity testing; technical supervisor.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... testing; technical supervisor. 493.1447 Section 493.1447 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1447 Condition: Laboratories performing high complexity testing; technical supervisor. The laboratory must have...

  3. 42 CFR 493.1447 - Condition: Laboratories performing high complexity testing; technical supervisor.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... testing; technical supervisor. 493.1447 Section 493.1447 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1447 Condition: Laboratories performing high complexity testing; technical supervisor. The laboratory must have...

  4. 42 CFR 493.1467 - Condition: Laboratories performing high complexity testing; cytology general supervisor.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... testing; cytology general supervisor. 493.1467 Section 493.1467 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1467 Condition: Laboratories performing high complexity testing; cytology general supervisor. For...

  5. 42 CFR 493.1361 - Condition: Laboratories performing PPM procedures; testing personnel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...; testing personnel. 493.1361 Section 493.1361 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Personnel for Nonwaived Testing Laboratories Performing Provider-Performed Microscopy (ppm) Procedures § 493.1361 Condition: Laboratories performing PPM procedures; testing personnel. The laboratory must have...

  6. 42 CFR 493.1487 - Condition: Laboratories performing high complexity testing; testing personnel.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... testing; testing personnel. 493.1487 Section 493.1487 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1487 Condition: Laboratories performing high complexity testing; testing personnel. The laboratory has...

  7. 42 CFR 493.1487 - Condition: Laboratories performing high complexity testing; testing personnel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... testing; testing personnel. 493.1487 Section 493.1487 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1487 Condition: Laboratories performing high complexity testing; testing personnel. The laboratory has...

  8. 42 CFR 493.1487 - Condition: Laboratories performing high complexity testing; testing personnel.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... testing; testing personnel. 493.1487 Section 493.1487 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1487 Condition: Laboratories performing high complexity testing; testing personnel. The laboratory has...

  9. 42 CFR 493.1361 - Condition: Laboratories performing PPM procedures; testing personnel.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...; testing personnel. 493.1361 Section 493.1361 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Personnel for Nonwaived Testing Laboratories Performing Provider-Performed Microscopy (ppm) Procedures § 493.1361 Condition: Laboratories performing PPM procedures; testing personnel. The laboratory must have...

  10. 42 CFR 493.1467 - Condition: Laboratories performing high complexity testing; cytology general supervisor.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... testing; cytology general supervisor. 493.1467 Section 493.1467 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1467 Condition: Laboratories performing high complexity testing; cytology general supervisor. For...

  11. 42 CFR 493.1487 - Condition: Laboratories performing high complexity testing; testing personnel.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... testing; testing personnel. 493.1487 Section 493.1487 Public Health CENTERS FOR MEDICARE & MEDICAID... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1487 Condition: Laboratories performing high complexity testing; testing personnel. The laboratory has...

  12. Investigation of influence of hypomagnetic conditions closely similar to interplanetary magnetic filed on behavioral and vegetative reactions of higher mammals

    NASA Astrophysics Data System (ADS)

    Krivova, Natalie; Trukhanov, Kiril; Zamotshina, Tatyana; Zaeva, Olga; Khodanovich, Marina; Misina, Tatyana; Tukhvatulin, Ravil; Suhko, Valery

    To study the influence of long being under reduced magnetic field on behavioral and vegetative reactions of higher mammals the white rat males were put into the 700-1000 times reduced geomagnetic field (50-70 nT) for 25 days. Such field was obtained by using automatic compensation of the horizontal and vertical components of the GMF at a frequencies up to 10 Hz by means of solenoids of the experimental magnetic system. Control animals were located in the same room under usual laboratory GMF conditions (52 uT). Two days before the experiment the behavioral reactions were studied in the "open field" by means of a set of tests, characterizing the level of emotionality, moving and orientational-investigative activities of the animals under conditions of unimpeded behavior. 60 white underbred rat males with the initial body mass of 200 g were divided into three clusters. Animals with average indices were selected for the experiment. We have judged behavioral reaction disturbances of the rats under hypomagnetic conditions using videotape recordings carried out in the entire course of the chronic experiment. According to the obtained results during the period of maximum activity (from 230 to 330 a.m.) the number of interrelations between the individuals increased appreciably for experimental rats including interrelations with aggressive character. This was real during all 25 days of observation. We observed a certain dynamics of this index differed from that of the control group. We have also analyzed the final period of observation from the 21th to the 25th days. In this period we studied the 24 hours' dynamics of interrelations which were noted during 5 minutes in every hour around the clock. In the control group the number of interrelation was at a constantly low level. For experimental animals the number of interrelations was higher in the night hours than in the day ones. Moreover it exceeded the similar indexes observed from the 1st to the 20th day. For example from

  13. Biological and photochemical degradation of cytostatic drugs under laboratory conditions.

    PubMed

    Franquet-Griell, Helena; Medina, Andrés; Sans, Carme; Lacorte, Silvia

    2017-02-05

    Cytostatic drugs, used in chemotherapy, have emerged as new environmental contaminants due to their recurrent presence in surface waters and genotoxic effects. Yet, their degradability and environmental fate is largely unknown. The aim of this study was to determine the degradation kinetics of 16 cytostatic drugs, prioritized according to their usage and occurrence in hospital and wastewater treatment plants (WWTP) effluents, through the following laboratory scale processes: hydrolysis, aerobic biodegradation, UV-C photolysis, UV-C/H2O2 and simulated solar radiation. Some drugs were unstable in milli-Q water (vincristine, vinblastine, daunorubicin, doxorubicin and irinotecan); others were photodegraded under UV-C light (melphalan and etoposide) but some others were found to be recalcitrant to biodegradation and/or UV-C, making necessary the use of advanced oxidation processes (AOPs) such as UV-C/H2O2 for complete elimination (cytarabine, ifosfamide and cyclophosphamide). Finally, radiation in a solar box was used to simulate the fate of cytostatic drugs in surface waters under natural radiation and complete removal was not observed for any drug. The degradation process was monitored using liquid chromatography coupled to high resolution mass spectrometry and pseudo-first order kinetic degradation constants were calculated. This study provides new data on the degradability of cytostatic compounds in water, thus contributing to the existing knowledge on their fate and risk in the environment.

  14. Weathering rates of marble in laboratory and outdoor conditions

    SciTech Connect

    Yerrapragada, S.S.; Chirra, S.R.; Jaynes, J.H.; Bandyopadhyay, J.K.; Gauri, K.L.; Li, S.

    1996-09-01

    In the modern urban atmosphere SO{sub 2} and NO{sub 2} attack calcite (CaCO{sub 3}) in marble exposed at rain-sheltered surfaces creating largely gypsum (CaSO{sub 4}{center_dot}2H{sub 2}O) crusts that eventually exfoliate. In combination with CO{sub 2} these gases erode the marble at unsheltered surfaces. the authors report the development of mathematical models to predict the rate of growth of crust and the rate of surface recession. To determine the rate of growth of crust the kinetic rate constant, diffusion rate, and the order of reaction were determined by the application of the shrinking-core model applied to data generated in laboratory experiments. Based on these parameters /and average ambient levels of 10 parts per billion (ppb) SO{sub 2} and 25 ppb NO{sub 2} in Louisville, Ky., the rate of crust formation for this metro area was calculated to be 1.8 {micro}m in the first year. However, the rate of recession was modeled from data obtained by exposing marble slabs to rainfalls. A surface recession of 15 {micro}m/yr was calculated. The models predicted well the rate of growth of crust observed at several sites in Louisville and the predicted surface recession compared well with values reported in the literature.

  15. Yersinia pestis infection and laboratory conditions alter flea-associated bacterial communities.

    PubMed

    Jones, Ryan T; Vetter, Sara M; Montenieiri, John; Holmes, Jennifer; Bernhardt, Scott A; Gage, Kenneth L

    2013-01-01

    We collected Oropsylla montana from rock squirrels, Spermophilus varigatus, and infected a subset of collected fleas with Yersinia pestis, the etiological agent of plague. We used bar-tagged DNA pyrosequencing to characterize bacterial communities of wild, uninfected controls and infected fleas. Bacterial communities within Y. pestis-infected fleas were substantially more similar to one another than communities within wild or control fleas, suggesting that infection alters the bacterial community in a directed manner such that specific bacterial lineages are severely reduced in abundance or entirely eliminated from the community. Laboratory conditions also significantly altered flea-associated bacterial communities relative to wild communities, but much less so than Y. pestis infection. The abundance of Firmicutes decreased considerably in infected fleas, and Bacteroidetes were almost completely eliminated from both the control and infected fleas. Bartonella and Wolbachia were unaffected or responded positively to Y. pestis infection.

  16. A comparative analysis of Painleve, Lax pair, and similarity transformation methods in obtaining the integrability conditions of nonlinear Schroedinger equations

    SciTech Connect

    Al Khawaja, U.

    2010-05-15

    We derive the integrability conditions of nonautonomous nonlinear Schroedinger equations using the Lax pair and similarity transformation methods. We present a comparative analysis of these integrability conditions with those of the Painleve method. We show that while the Painleve integrability conditions restrict the dispersion, nonlinearity, and dissipation/gain coefficients to be space independent and the external potential to be only a quadratic function of position, the Lax Pair and the similarity transformation methods allow for space-dependent coefficients and an external potential that is not restricted to the quadratic form. The integrability conditions of the Painleve method are retrieved as a special case of our general integrability conditions. We also derive the integrability conditions of nonautonomous nonlinear Schroedinger equations for two- and three-spacial dimensions.

  17. Amphetamine-induced sensitization and reward uncertainty similarly enhance incentive salience for conditioned cues.

    PubMed

    Robinson, Mike J F; Anselme, Patrick; Suchomel, Kristen; Berridge, Kent C

    2015-08-01

    Amphetamine and stress can sensitize mesolimbic dopamine-related systems. In Pavlovian autoshaping, repeated exposure to uncertainty of reward prediction can enhance motivated sign-tracking or attraction to a discrete reward-predicting cue (lever-conditioned stimulus; CS+), as well as produce cross-sensitization to amphetamine. However, it remains unknown how amphetamine sensitization or repeated restraint stress interact with uncertainty in controlling CS+ incentive salience attribution reflected in sign-tracking. Here rats were tested in 3 successive phases. First, different groups underwent either induction of amphetamine sensitization or repeated restraint stress, or else were not sensitized or stressed as control groups (either saline injections only, or no stress or injection at all). All next received Pavlovian autoshaping training under either certainty conditions (100% CS-UCS association) or uncertainty conditions (50% CS-UCS association and uncertain reward magnitude). During training, rats were assessed for sign-tracking to the CS+ lever versus goal-tracking to the sucrose dish. Finally, all groups were tested for psychomotor sensitization of locomotion revealed by an amphetamine challenge. Our results confirm that reward uncertainty enhanced sign-tracking attraction toward the predictive CS+ lever, at the expense of goal-tracking. We also reported that amphetamine sensitization promoted sign-tracking even in rats trained under CS-UCS certainty conditions, raising them to sign-tracking levels equivalent to the uncertainty group. Combining amphetamine sensitization and uncertainty conditions did not add together to elevate sign-tracking further above the relatively high levels induced by either manipulation alone. In contrast, repeated restraint stress enhanced subsequent amphetamine-elicited locomotion, but did not enhance CS+ attraction.

  18. Laboratory measurements of materials in extreme conditions; The use of high energy radiation sources for high pressure studies

    SciTech Connect

    Cauble, R.; Remington, B.A.

    1998-06-01

    High energy lasers can be used to study material conditions that are appropriate fort inertial confinement fusion: that is, materials at high densities, temperatures, and pressures. Pulsed power devices can offer similar opportunities. The National Ignition Facility (NIF) will be a high energy multi-beam laser designed to achieve the thermonuclear ignition of a mm-scale DT-filled target in the laboratory. At the same time, NE will provide the physics community with a unique tool for the study of high energy density matter at states unreachable by any other laboratory technique. Here we describe how these lasers and pulsed power tools can contribute to investigations of high energy density matter in the areas of material properties and equations of state, extend present laboratory shock techniques such as high-speed jets to new regimes, and allow study of extreme conditions found in astrophysical phenomena.

  19. Large and meso scale eddy structures forced by a river flow in the west Mediterranean under rotating conditions: Numerical and laboratory experiments.

    NASA Astrophysics Data System (ADS)

    Carrillo, J.; Redondo, J.; Fraunie, P.; Durand, N.

    2003-04-01

    This work presents the results of two laboratory and numerical experiments. The characteristic induced structures by stationer typical conditions from spring, summer, fall and winter. Laboratory experiences were developed on a five meters turntable (SINTEF facilities) obeys the Froude-Rossby similarities. While, the meso-escale numerical model was developed in the LSEET laboratory. This work evidences complementary results from the vortex sort characteristic by radius from both experimental and model methods. Additionally numerical model has a better representation from the conditions in the first 15km and the laboratory model represent the resolution between the large and the meso scale boundary.

  20. Resin-based composite light-cured properties assessed by laboratory standards and simulated clinical conditions.

    PubMed

    Ilie, N; Bauer, H; Draenert, M; Hickel, R

    2013-01-01

    SUMMARY The following parameters were varied: 1) irradiation technique: top and bottom polymerization according to the ISO standard, and polymerization from only the top, simulating clinical situations; 2) polymerization time: 5, 10, 20, and 40 seconds; 3) storage conditions: 24 hours in distilled water, thermocycling followed by storage for four weeks in artificial saliva or alcohol. Flexural strength (FS), flexural modulus (Eflexural), indentation modulus (E), Vickers hardness (HV), and degree of conversion (DC) were measured. The laboratory results were similar to those measured by mimicking clinical conditions only at high polymerization times and mild storage conditions (20 seconds and 40 seconds and storage for 24 hours in water, and 40 seconds with aging and storing in saliva). Significantly higher DC values were measured on the top than on the bottom of a 2-mm layer for all polymerization times. Overall, 5-second and 10-second irradiation times induced significantly lower DC values compared to the currently recommended polymerization times of 20 and 40 seconds at both the top and bottom of the samples. The initial DC differences as a function of irradiation time are leveled at 24 hours of storage but seem to do well in predicting long-term material behavior. A minimum irradiation time of 20 seconds is necessary clinically to achieve the best mechanical properties with modern high-intensity light emitting diode (LED) units.

  1. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1985-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and Earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often lead to significant misinterpretation of available opacity data. Steffes and Eshleman showed that under environmental conditions corresponding to the middle atmosphere of Venus, the microwave absorption due to atmospheric SO2 was 50 percent greater than that calculated from Van Vleck-Weiskopff theory. Similarly, the opacity from gaseous H2SO4 was found to be a factor of 7 greater than theoretically predicted for conditions of the Venus middle atmosphere. The recognition of the need to make such measurements over a range of temperatures and pressures which correspond to the periapsis altitudes of radio occultation experiments, and over a range of frequencies which correspond to both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements.

  2. Hind limb unloading, a model of spaceflight conditions, leads to decreased B lymphopoiesis similar to aging.

    PubMed

    Lescale, Chloé; Schenten, Véronique; Djeghloul, Dounia; Bennabi, Meriem; Gaignier, Fanny; Vandamme, Katleen; Strazielle, Catherine; Kuzniak, Isabelle; Petite, Hervé; Dosquet, Christine; Frippiat, Jean-Pol; Goodhardt, Michele

    2015-02-01

    Within the bone marrow, the endosteal niche plays a crucial role in B-cell differentiation. Because spaceflight is associated with osteoporosis, we investigated whether changes in bone microstructure induced by a ground-based model of spaceflight, hind limb unloading (HU), could affect B lymphopoiesis. To this end, we analyzed both bone parameters and the frequency of early hematopoietic precursors and cells of the B lineage after 3, 6, 13, and 21 d of HU. We found that limb disuse leads to a decrease in both bone microstructure and the frequency of B-cell progenitors in the bone marrow. Although multipotent hematopoietic progenitors were not affected by HU, a decrease in B lymphopoiesis was observed as of the common lymphoid progenitor (CLP) stage with a major block at the progenitor B (pro-B) to precursor B (pre-B) cell transition (5- to 10-fold decrease). The modifications in B lymphopoiesis were similar to those observed in aged mice and, as with aging, decreased B-cell generation in HU mice was associated with reduced expression of B-cell transcription factors, early B-cell factor (EBF) and Pax5, and an alteration in STAT5-mediated IL-7 signaling. These findings demonstrate that mechanical unloading of hind limbs results in a decrease in early B-cell differentiation resembling age-related modifications in B lymphopoiesis.

  3. 42 CFR 493.1453 - Condition: Laboratories performing high complexity testing; clinical consultant.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... testing; clinical consultant. 493.1453 Section 493.1453 Public Health CENTERS FOR MEDICARE & MEDICAID... Condition: Laboratories performing high complexity testing; clinical consultant. The laboratory must have a clinical consultant who meets the requirements of § 493.1455 of this subpart and provides...

  4. 42 CFR 493.1415 - Condition: Laboratories performing moderate complexity testing; clinical consultant.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... complexity testing; clinical consultant. 493.1415 Section 493.1415 Public Health CENTERS FOR MEDICARE... § 493.1415 Condition: Laboratories performing moderate complexity testing; clinical consultant. The laboratory must have a clinical consultant who meets the qualification requirements of § 493.1417 of...

  5. Training of astronauts in laboratory-aircraft under weightless conditions for work in space

    NASA Technical Reports Server (NTRS)

    Khrunov, Y. V.; Chekidra, I. F.; Kolosov, I. A.

    1975-01-01

    Analyses of occupational activities of astronauts in laboratory-aircraft flights simulating weightlessness conditions permit the development of training methods and optimization of the interaction of man with various spacecraft designs.

  6. Place, not race: disparities dissipate in southwest Baltimore when blacks and whites live under similar conditions.

    PubMed

    LaVeist, Thomas; Pollack, Keshia; Thorpe, Roland; Fesahazion, Ruth; Gaskin, Darrell

    2011-10-01

    Much of the current health disparities literature fails to account for the fact that the nation is largely segregated, leaving racial groups exposed to different health risks and with variable access to health services based on where they live. We sought to determine if racial health disparities typically reported in national studies remain the same when black and white Americans live in integrated settings. Focusing on a racially integrated, low-income neighborhood of Southwest Baltimore, Maryland, we found that nationally reported disparities in hypertension, diabetes, obesity among women, and use of health services either vanished or substantially narrowed. The sole exception was smoking: We found that white residents were more likely than black residents to smoke, underscoring the higher rates of ill health in whites in the Baltimore sample than seen in national data. As a result, we concluded that racial differences in social environments explain a meaningful portion of disparities typically found in national data. We further concluded that when social factors are equalized, racial disparities are minimized. Policies aimed solely at health behavior change, biological differences among racial groups, or increased access to health care are limited in their ability to close racial disparities in health. Such policies must address the differing resources of neighborhoods and must aim to improve the underlying conditions of health for all.

  7. Climate Twins - a tool to explore future climate impacts by assessing real world conditions: Exploration principles, underlying data, similarity conditions and uncertainty ranges

    NASA Astrophysics Data System (ADS)

    Loibl, Wolfgang; Peters-Anders, Jan; Züger, Johann

    2010-05-01

    To achieve public awareness and thorough understanding about expected climate changes and their future implications, ways have to be found to communicate model outputs to the public in a scientifically sound and easily understandable way. The newly developed Climate Twins tool tries to fulfil these requirements via an intuitively usable web application, which compares spatial patterns of current climate with future climate patterns, derived from regional climate model results. To get a picture of the implications of future climate in an area of interest, users may click on a certain location within an interactive map with underlying future climate information. A second map depicts the matching Climate Twin areas according to current climate conditions. In this way scientific output can be communicated to the public which allows for experiencing climate change through comparison with well-known real world conditions. To identify climatic coincidence seems to be a simple exercise, but the accuracy and applicability of the similarity identification depends very much on the selection of climate indicators, similarity conditions and uncertainty ranges. Too many indicators representing various climate characteristics and too narrow uncertainty ranges will judge little or no area as regions with similar climate, while too little indicators and too wide uncertainty ranges will address too large regions as those with similar climate which may not be correct. Similarity cannot be just explored by comparing mean values or by calculating correlation coefficients. As climate change triggers an alteration of various indicators, like maxima, minima, variation magnitude, frequency of extreme events etc., the identification of appropriate similarity conditions is a crucial question to be solved. For Climate Twins identification, it is necessary to find a right balance of indicators, similarity conditions and uncertainty ranges, unless the results will be too vague conducting a

  8. Similar and Promising Outcomes in Lymphoma Patients Treated with Myeloablative or Nonmyeloablative Conditioning and Allogeneic Hematopoietic Cell Transplantation

    PubMed Central

    Tomblyn, Marcie; Brunstein, Claudio; Burns, Linda J.; Miller, Jeffrey S.; MacMillan, Margaret; DeFor, Todd E.; Weisdorf, Daniel J.

    2008-01-01

    We compared the outcomes of 141 consecutive patients who received allogeneic transplantation with either myeloablative (MA) or nonmyeloablative/reduced intensity (NMA) conditioning for non-Hodgkin and Hodgkin lymphoma at the University of Minnesota. All patients were transplanted between 1997 and 2004. NMA transplant recipients were older and received umbilical cord blood grafts more frequently (MA: 6 [9%]; NMA: 33 [43%], P < .001). NMA patients had more advanced disease and 30 (39%) patients had undergone prior autologous transplantation. The 4-year overall survival (OS) (MA: 46% versus NMA: 49%; p = .34) and the 3-year progression-free survival (PFS) (MA: 44% versus NMA: 31%; P = 0.82) were similar after MA or NMA conditioning. However, MA conditioning resulted in significantly higher 1-year treatment-related mortality (TRM) (MA: 43% versus NMA: 17%; P < .01) but a lower risk of relapse at 3 years (MA: 11% versus NMA: 36%; P < .01). We conclude that similar transplant outcomes are achieved after allogeneic hematopoietic stem cell transplantation using MA conditioning in younger patients and NMA conditioning in older patients or those with prior autologous transplantation not eligible for MA conditioning. Modifications to refine patient assignment to the preferred conditioning intensity and reduce relapse risks with NMA approaches are needed. PMID:18410896

  9. Cross-polarization microwave radar return at severe wind conditions: laboratory model and geophysical model function.

    NASA Astrophysics Data System (ADS)

    Troitskaya, Yuliya; Abramov, Victor; Ermoshkin, Alexey; Zuikova, Emma; Kazakov, Vassily; Sergeev, Daniil; Kandaurov, Alexandr

    2014-05-01

    (friction velocity and roughness height) were retrieved by velocity profiling and subsequent data processing based on self-similarity of the turbulent boundary layer and 10-m wind speed was calculated. The wind wave field parameters in the flume were measured by three wire gauges. The measured data on wind waves were used for estimation of the short wave spectra and slope probability density function for "long waves" within composite Bragg theory of microwave radar return. Estimations showed that for co-polarized radar returns the difference between measurements and the predictions of the model is about 1-2 dB and it can be explained by our poor knowledge about the short wave part of the spectrum. For cross-polarized return the difference exceeds 10 dB, and it indicates that some non-Bragg mechanisms (short-crested waves, foam, sprays, etc) are responsible for the depolarization of the returned signal. It seems reasonable then to suppose that the cross-polarized radar return in X- and C-bands will demonstrate similar dependence on wind speed. We compared the dependence of cross-polarized X-band radar cross-section on 10-m wind speed obtained in laboratory conditions with the similar dependence obtained in [2] from the field data for C-band radar cross-section and found out that the laboratory data follow the median of the field data with the constant bias -11 dB. Basing on laboratory data an empirical polynomial geophysical model function was suggested for retrieving wind speed up to 40 m/s from cross-polarized microwave return, which is in good agreement with the direct measurements. This work was carried out under financial support of the RFBR (project codes ¹ 13-05-00865, 12-05-12093) and by grant from the Government of the Russian Federation (project code 11.G34.31.0048). References [1] B. Zhang, W. Perrie Bull. Amer. Meteor. Soc., 93, 531-541, 2012. [2] G.-J. van Zadelhoff, et.al. Atmos. Meas. Tech. Discuss., 6, 7945-7984, doi:10.5194/amtd-6-7945-2013, 2013.

  10. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1987-01-01

    Laboratory measurements were conducted to evaluate properties of atmospheric gases under simulated conditions for the outer planets. A significant addition to this effort was the capability to make such measurements at millimeter wavelengths. Measurements should soon be completed on the millimeter wave absorption from ammonia under Jovian conditions. Also studied will be the feasibility of measuring the microwave and millimeter wave properties of phosphine (PH3) under simulated Jovian conditions. Further analysis and application of the laboratory results to microwave and millimeter wave absorption data for the outer planet, such as Voyager Radio Occultation experiments, will be pursued.

  11. Memory Elicited by Courtship Conditioning Requires Mushroom Body Neuronal Subsets Similar to Those Utilized in Appetitive Memory

    PubMed Central

    Montague, Shelby A.; Baker, Bruce S.

    2016-01-01

    An animal’s ability to learn and to form memories is essential for its survival. The fruit fly has proven to be a valuable model system for studies of learning and memory. One learned behavior in fruit flies is courtship conditioning. In Drosophila courtship conditioning, male flies learn not to court females during training with an unreceptive female. He retains a memory of this training and for several hours decreases courtship when subsequently paired with any female. Courtship conditioning is a unique learning paradigm; it uses a positive-valence stimulus, a female fly, to teach a male to decrease an innate behavior, courtship of the female. As such, courtship conditioning is not clearly categorized as either appetitive or aversive conditioning. The mushroom body (MB) region in the fruit fly brain is important for several types of memory; however, the precise subsets of intrinsic and extrinsic MB neurons necessary for courtship conditioning are unknown. Here, we disrupted synaptic signaling by driving a shibirets effector in precise subsets of MB neurons, defined by a collection of split-GAL4 drivers. Out of 75 lines tested, 32 showed defects in courtship conditioning memory. Surprisingly, we did not have any hits in the γ lobe Kenyon cells, a region previously implicated in courtship conditioning memory. We did find that several γ lobe extrinsic neurons were necessary for courtship conditioning memory. Overall, our memory hits in the dopaminergic neurons (DANs) and the mushroom body output neurons were more consistent with results from appetitive memory assays than aversive memory assays. For example, protocerebral anterior medial DANs were necessary for courtship memory, similar to appetitive memory, while protocerebral posterior lateral 1 (PPL1) DANs, important for aversive memory, were not needed. Overall, our results indicate that the MB circuits necessary for courtship conditioning memory coincide with circuits necessary for appetitive memory. PMID

  12. Hydrologic conditions at the Idaho National Engineering Laboratory, Idaho, emphasis; 1974-1978

    USGS Publications Warehouse

    Barraclough, Jack T.; Lewis, Barney D.; Jensen, Rodger G.

    1981-01-01

    Aqueous chemical and radioactive wastes have been discharged to shallow ponds and to shallow or deep wells on the Idaho National Engineering Laboratory (INEL) since 1952 and has affected the quality of the ground water in the underlying Snake River Plain aquifer. Ongoing studies conducted from 1974 through 1978 have shown the perpetuation of a perched ground-water zone in the basalt underlying the waste disposal ponds at the INEL 's Test Reactor Area and of several waste plumes in the regional aquifer created by deep well disposal at the Idaho Chemical Processing Plant (ICPP). The perched zone contains tritium, chromium-51, cobalt-60, strontium-90, and several nonradioactive chemicals. Tritium has formed the largest waste plume south of the ICPP, and accounts for 95 percent of the total radioacticity disposed of through the ICPP disposal well. Waste plumes with similar configurations and flowpaths contain sodium, chloride, and nitrate. Strontium-90, iodine-129, and cesium-137 are also discharged through the well but they are sorbed from solution as they move through the aquifer or are discharged in very small quantities. Strontium-90 and iodine-129 have formed small waste plumes and cesium-137 is not detectable in ground-water samples. Radionuclide plume size and concentrations therein are controlled by aquifer flow conditions, the quantity discharged, radioactive decay, sorption, dilution by dispersion, and perhaps other chemical reactions. Chemical wastes are subject to the same processes except for radioactive decay. (USGS)

  13. An assessment of Hyalella azteca burrowing activity under laboratory sediment toxicity testing conditions.

    PubMed

    Doig, Lorne E; Liber, Karsten

    2010-09-01

    Burrowing of the freshwater amphipod Hyalella azteca was evaluated under laboratory conditions similar to those recommended for standard sediment toxicity testing in Canada (EPS 1/RM/33; Environment Canada, 1997) and the United States (EPA/600/R-99/064; US EPA, 2000). Sediment type, time of day (light versus dark), size of animal, and the presence or absence of food were varied to assess their effects on burrowing activity. Hyalella azteca were found to burrow rapidly in fine, organic-rich sediments, but were slower to burrow in a sandy sediment. There was no increase in the number of animals occupying the sediment surface of a fine, organic-rich sediment after 4h of darkness compared to the previous 4h of light. Over a 9- to 10-d duration, a higher percentage of animals occupied the surface of the sandy sediment. The addition of food promoted burrowing in sandy sediment, as did using smaller animals. Overall, longer-duration tests involving older animals and coarse sediments may require formal observation to confirm burrowing and ensure adequate sediment exposure. The addition of food during a test may promote the burrowing of larger animals in coarse sediments, but may not be necessary in field-collected sediments that are not excessively sandy.

  14. Communities of different plant diversity respond similarly to drought stress: experimental evidence from field non-weeded and greenhouse conditions.

    PubMed

    Lanta, Vojtěch; Doležal, Jiří; Zemková, Lenka; Lepš, Jan

    2012-06-01

    Accelerating rate of species loss has prompted researchers to study the role of species diversity in processes that control ecosystem functioning. Although negative impact of species loss has been documented, the evidence concerning its impact on ecosystem stability is still limited. Here, we studied the effects of declining species and functional diversity on plant community responses to drought in the field (open to weed colonization) and greenhouse conditions. Both species and functional diversity positively affected the average yields of field communities. However, this pattern was similar in both drought-stressed and control plots. No effect of diversity on community resistance, biomass recovery after drought and resilience was found because drought reduced biomass production similarly at each level of diversity by approximately 30%. The use of dissimilarity (characterized by Euclidean distance) revealed higher variation under changing environments (drought-stressed vs. control) in more diverse communities compared to less species-rich assemblages. In the greenhouse experiment, the effect of species diversity affected community resistance, indicating that more diverse communities suffered more from drought than species-poor ones. We conclude that our study did not support the insurance hypothesis (stability properties of a community should increase with species richness) because species diversity had an equivocal effect on ecosystem resistance and resilience in an environment held under non-weeded practice, regardless of the positive relationship between sown species diversity and community biomass production. More species-rich communities were less resistant against drought-stressed conditions than species-poor ones grown in greenhouse conditions.

  15. Communities of different plant diversity respond similarly to drought stress: experimental evidence from field non-weeded and greenhouse conditions

    NASA Astrophysics Data System (ADS)

    Lanta, Vojtěch; Doležal, Jiří; Zemková, Lenka; Lepš, Jan

    2012-06-01

    Accelerating rate of species loss has prompted researchers to study the role of species diversity in processes that control ecosystem functioning. Although negative impact of species loss has been documented, the evidence concerning its impact on ecosystem stability is still limited. Here, we studied the effects of declining species and functional diversity on plant community responses to drought in the field (open to weed colonization) and greenhouse conditions. Both species and functional diversity positively affected the average yields of field communities. However, this pattern was similar in both drought-stressed and control plots. No effect of diversity on community resistance, biomass recovery after drought and resilience was found because drought reduced biomass production similarly at each level of diversity by approximately 30 %. The use of dissimilarity (characterized by Euclidean distance) revealed higher variation under changing environments (drought-stressed vs. control) in more diverse communities compared to less species-rich assemblages. In the greenhouse experiment, the effect of species diversity affected community resistance, indicating that more diverse communities suffered more from drought than species-poor ones. We conclude that our study did not support the insurance hypothesis (stability properties of a community should increase with species richness) because species diversity had an equivocal effect on ecosystem resistance and resilience in an environment held under non-weeded practice, regardless of the positive relationship between sown species diversity and community biomass production. More species-rich communities were less resistant against drought-stressed conditions than species-poor ones grown in greenhouse conditions.

  16. Mechanical design, analysis, and laboratory testing of a dental implant with axial flexibility similar to natural tooth with periodontal ligament.

    PubMed

    Pektaş, Ömer; Tönük, Ergin

    2014-11-01

    At the interface between the jawbone and the roots of natural teeth, a thin, elastic, shock-absorbing tissue, called the periodontal ligament, forms a cushion which provides certain flexibility under mechanical loading. The dental restorations supported by implants, however, involve comparatively rigid connections to the jawbone. This causes overloading of the implant while bearing functional loading together with neighboring natural teeth, which leads to high stresses within the implant system and in the jawbone. A dental implant, with resilient components in the upper structure (abutment) in order to mimic the mechanical behavior of the periodontal ligament in the axial direction, was designed, analyzed in silico, and produced for mechanical testing. The aims of the design were avoiding high levels of stress, loosening of the abutment connection screw, and soft tissue irritations. The finite element analysis of the designed implant revealed that the elastic abutment yielded a similar axial mobility with the natural tooth while keeping stress in the implant at safe levels. The in vitro mechanical testing of the prototype resulted in similar axial mobility predicted by the analysis and as that of a typical natural tooth. The abutment screw did not loosen under repeated loading and there was no static or fatigue failure.

  17. Recreation of Marine Atmospheric Corrosion Condition on Weathering Steel in Laboratory

    NASA Astrophysics Data System (ADS)

    Guchhait, S. K.; Dewan, S.; Saha, J. K.; Mitra, P. K.

    2014-04-01

    Salt spray test, autoclave corrosion test, SO2 salt spray test, and Relative humidity test are generally used to assess atmospheric corrosion in laboratories at accelerated rates. However, no test can absolutely simulate the service condition. One can get only approximate corrosion rates using the aforesaid tests which serve as an indicative of corrosion behavior of the material in a service condition. The present work is aimed at creating specific environmental condition in laboratory to get the corrosion test done in short duration to compare with on field exposure test which would otherwise take years to complete. In this work recreation of atmospheric environment of Digha was tried and it was simulated in such a manner that the results of laboratory test could be compared with long time field exposure at Digha. Weathering steel (WS) was taken for experimentations. Potentiostatic electrochemical tests route was adopted to simulate atmospheric condition of Digha. Laboratory test results compared well with 18 month field exposure data in terms of corrosion rate, SEM and Ramon Spectroscopy matching.

  18. A novel method for condition monitoring of rotating machinery based on statistical linguistic analysis and weighted similarity measures

    NASA Astrophysics Data System (ADS)

    Lin, Jinshan; Dou, Chunhong

    2017-03-01

    Defective rotating machinery generally produces complex fluctuations due to non-stationary and nonlinear properties of dynamical systems. Consequently, dynamical structures of vibration data from rotating machinery are hard to disclose. As a result, condition monitoring of rotating machinery is fairly challenging. In this paper, statistical linguistic analysis (SLA), a novel tool for time series analysis, was introduced to analyze dynamical mechanisms hidden in vibration data of rotating machinery. SLA maps original vibration data from rotating machinery to a binary symbolic sequence by exploiting potential of increase and decreases of time intervals. Next, by sliding a window and identifying the elements in each window as a "word", a group of words is created. Then, by counting the occurrence of each word type, the binary symbolic sequence can be converted into a word frequency sequence. Next, a weighted similarity measure (WSM) defined in this paper serves to detect a change of running conditions of rotating machinery. As a result, this paper proposed a novel method for condition monitoring of rotating machinery based on SLA and WSM. Afterwards, the performance of the proposed method was validated using vibration data from both gearboxes and rolling bearings. Also, the proposed method was compared with conventional temporal statistical parameters, Approximate Entropy and Sample Entropy. The results indicate that the proposed method performs better than the other methods in condition monitoring of rotating machinery. Also, compared with either of Correlation Coefficients and Standardized Euclidean Distances, the WSM gives a somewhat better performance in reflecting a change of dynamical structures.

  19. Sandy beach macrofaunal communities on the western coast of Portugal - Is there a steady structure under similar exposed conditions?

    NASA Astrophysics Data System (ADS)

    Gonçalves, Sílvia C.; Anastácio, Pedro M.; Pardal, Miguel A.; Cardoso, Patrícia G.; Ferreira, Susana M.; Marques, João C.

    2009-03-01

    The structure of macrofaunal communities at two similar exposed sandy beaches on the western coast of Portugal was monitored for approximately 18 months by sampling all the beach area, from the shoreline to the base of the dunes. The beaches' physical environment, as well as community density and composition, seasonal variations and the potential relationships between biological data and environmental parameters were studied. The two beaches had similar exposure to wave action, but differed in terms of sediment grain size, extent of the intertidal area, sediment moisture content and, especially, in the potential food availability in the form of allochthonous debris. Differences were observed with regard to the communities' structure, namely regarding composition and relative contribution of the dominant species. Seasonality, especially temperature variations, and the interaction between seasons and the beach zones (supralittoral vs. intertidal) also had a strong influence on communities: controlling dominant species' density and the horizontal distribution of the dominant species, and promoting a differential utilization of the beach by several resident macrofaunal animals. The present study allows the identification of key species in exposed sandy beaches of western Portugal and demonstrates that a steady community structure does not persist in the similarly exposed conditions observed, which may be mainly a response to distinct detritus subsidies, combined with differences in sediment grain size, sediment moisture content and extent of the intertidal area.

  20. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1991-01-01

    Laboratory measurements of microwave and millimeter wave properties of the simulated atmosphere of the outer planets and their satellites has continued. One of the focuses is on the development of a radiative transfer model of the Jovian atmosphere at wavelengths from 1 mm to 10 cm. This modeling effort led to laboratory measurements of the millimeter wave opacity of hydrogen sulfide (H2S) under simulated Jovian conditions. Descriptions of the modeling effort, the Laboratory experiment, and the observations are presented. Correlative studies of measurements with Pioneer-Venus radio occultation measurements with longer wavelength emission measurements have provided new ways for characterizing temporal and spatial variations in the abundance of both gases H2SO4 and SO2, and for modeling their roles in the subcloud atmosphere. Laboratory measurements were conducted on 1.35 cm (and 13 cm) opacity of gaseous SO2 and absorptivity of gaseous SO2 at the 3.2 mm wavelength under simulated Venus conditions. Laboratory measurements were completed on millimeter wave dielectric properties of liquid H2SO4, in order to model the effects of the opacity of the clouds of Venus onto millimeter wave emission spectrum.

  1. Longevity and survival curves of Rhinella icterica (Anura, Bufonidae) under laboratory conditions.

    PubMed

    Lima, M S C S; Pederassi, J; Souza, C A S

    2014-05-01

    Life tables and survival curves of tadpoles from Rhinella icterica species were studied in the laboratory, under abiotic conditions controlled by a purification filter, a timer and a chiller. The survival curve for larval stage confirms a great mortality trend in the initial stages, which decreases when reaching the mature morphological condition (r = -0.94). Stages 37, 38, 39, 40 and 41 showed gradual values for their age structures, while stages 42, 43 and 44 presented high variations. Based on the results under laboratory conditions, it can be concluded that the maturity of R. icterica tadpoles development between 37 and 44 stages has a negative correlation and their predicted life expectancy is a logarithmic growth curve (y=-761.96Ln(x)+5298.5).

  2. Individuals Maintain Similar Rates of Protein Synthesis over Time on the Same Plane of Nutrition under Controlled Environmental Conditions

    PubMed Central

    McCarthy, Ian D.; Owen, Stewart F.; Watt, Peter W.; Houlihan, Dominic F.

    2016-01-01

    Consistent individual differences in animal performance drive individual fitness under variable environmental conditions and provide the framework through which natural selection can operate. Underlying this concept is the assumption that individuals will display consistent levels of performance in fitness-related traits and interest has focused on individual variation and broad sense repeatability in a range of behavioural and physiological traits. Despite playing a central role in maintenance and growth, and with considerable inter-individual variation documented, broad sense repeatability in rates of protein synthesis has not been assessed. In this study we show for the first time that juvenile flounder Platichthys flesus reared under controlled environmental conditions on the same plane of nutrition for 46 days maintain consistent whole-animal absolute rates of protein synthesis (As). By feeding meals containing 15N-labelled protein and using a stochastic end-point model, two non-terminal measures of protein synthesis were made 32 days apart (d14 and d46). As values (mass-corrected to a standard mass of 12 g) showed 2- to 3-fold variation between individuals on d14 and d46 but individuals showed similar As values on both days with a broad sense repeatability estimate of 0.684 indicating significant consistency in physiological performance under controlled experimental conditions. The use of non-terminal methodologies in studies of animal ecophysiology to make repeat measures of physiological performance enables known individuals to be tracked across changing conditions. Adopting this approach, repeat measures of protein synthesis under controlled conditions will allow individual ontogenetic changes in protein metabolism to be assessed to better understand the ageing process and to determine individual physiological adaptive capacity, and associated energetic costs of adaptation, to global environmental change. PMID:27018996

  3. Comparison of the acceptability ratings of appetizers under laboratory, base level and high altitude field conditions.

    PubMed

    Premavalli, K S; Wadikar, D D; Nanjappa, C

    2009-08-01

    The relationship between laboratory and field ratings was investigated for six different appetizers, including four ready-to-reconstitute mixes and two ready-to-eat munches. Liking ratings on a 5-point hedonic scale were obtained from an Indian Army field study at base level as well as at an altitude of 11,500 ft above sea level and for the same appetizers in the laboratory. The field trials of the six products were conducted in two phases and results revealed that the products were more acceptable at altitude, with increased liking scores as compared to base level. Subjective ratings for hunger revealed that at altitude, appetizer consumption had stimulated the appetite of the soldiers. The ability of laboratory ratings to predict acceptability of foods consumed under realistic conditions appears to depend on the convenience of the appetizer as well as the environmental conditions and the psycho-physiological status of the participants. The appetizers received higher ratings at altitude because of the pungent and spicy nature of appetizer mixes as compared with base field and laboratory conditions. However, for all the appetizers the pungent and sweet taste of the appetizer munches was highly preferred.

  4. Life cycle of Ornithodoros rostratus (Acari: Argasidae) ticks feeding on mice under laboratory conditions.

    PubMed

    Costa, Gabriel Cerqueira Alves; Soares, Adriana Coelho; Pereira, Marcos Horácio; Gontijo, Nelder Figueiredo; Sant'Anna, Maurício Roberto Viana; Araujo, Ricardo Nascimento

    2015-05-01

    Ornithodoros rostratus Aragão is an argasid tick found in Bolivia, Paraguay, Argentina and Brazil. Only limited studies about O. rostratus have been conducted and several aspects of their life cycle differ among studies or remain unexplored. In order to better elucidate the biology of O. rostratus, the present work describes its life cycle when feeding on mice under laboratory conditions. To complete their life cycle on mice, O. rostratus goes through a larval stage, 3-6 nymphal instars (nymph 1-6) and adult male and female. Adults can be originated from nymph 3-6. Nymphs 4 with higher weight after feeding tend to originate adults. Adults originated from early instars tended to be lighter. Females tended to be heavier than males. Larvae needed on average 2.7 days to complete their blood meal whereas other instars ranged from 17.3 to 78.3 min. The capacity to ingest blood was higher in larvae and females in comparison to males. The preecdysis period ranged from 5 to 12.5 days. After one blood meal, females remain on average 15.2 ± 5.8 days laying 276.8 ± 137.2.9 eggs. Females originated from nymph 4 had similar oviposition time, egg incubation and conversion ingested blood/number of eggs produced, but presented lower initial weigh and weigh gain, generating fewer eggs. Our results added novel information on O. rostratus biology and was discussed considering the variability of argasid populations and in context with the differences about their life cycle described in previous works.

  5. Do laboratory rearing conditions affect auditory and mechanosensory development of zebrafish (Danio rerio)?

    NASA Astrophysics Data System (ADS)

    Poling, Kirsten R.; Jaworski, Eva; Fantetti, Kristen R.; Higgs, Dennis M.

    2005-04-01

    The effect of anthropogenic noise on the fish auditory system has become of increasing concern due to possible detrimental effects of intense sounds on auditory function and structures. This is especially problematic when raising fish in laboratory and aquaculture settings using filtration and aeration, which increase sound levels. To assess the effects of laboratory rearing conditions, one group of zebrafish (Danio rerio) embryos (``controls'') were placed into aerated aquaria in a normal laboratory rearing environment. A second set of embryos (``quiet'') were reared in aquaria with no aeration or filtration in a sound-resistant room. The intensity difference between the two sets of tanks was over 30 dB. Preliminary data show that there was no affect of differential rearing environments on saccular hair cell numbers or on hearing ability in fish up to 25 mm total length. However, rearing environment did affect neuromast number. ``Quiet'' fish had higher numbers of both cephalic and trunk superficial neuromasts, relative to controls. This difference was maintained up to 11 mm total length (the size at which canal formation begins). This suggests that acoustic environments normally found in the laboratory do not affect development of hearing in zebrafish, although laboratory acoustics may affect mechanosensory development.

  6. Laboratory analysis of gas hydrate cores for evaluation of reservoir conditions. Final report

    SciTech Connect

    Holder, G.D.

    1984-06-01

    Methodology and procedures for the study of hydrate cores are detailed. Topics discussed are the (1) equipment and procedures for the formation and evaluation of hydrate cores in the laboratory, (2) the thermodynamic properties of gas hydrates, (3) the enthalpy of hydrate dissociation, (4) conditions in the earth where hydrates can form, (5) kinetics of hydrate formation and dissociation, and (6) heat transfer to gas hydrates. Empirical correlations for these properties and kinetic behavior are given. 24 references, 39 figures, 10 tables.

  7. The effectiveness of jute and coir blankets for erosion control in different field and laboratory conditions

    NASA Astrophysics Data System (ADS)

    Kalibová, Jana; Jačka, Lukáš; Petrů, Jan

    2016-03-01

    Vegetation cover is found to be an ideal solution to most problems of erosion on steep slopes. Biodegradable geotextiles (GTXs) have been proved to provide sufficient protection against soil loss in the period before vegetation reaches maturity, so favouring soil formation processes. In this study, 500 g m-2 jute (J500), 400 g m-2 (C400), and 700 g m-2 coir (C700) GTXs were first installed on a 9° slope under "no-infiltration" laboratory conditions, then on a 27° slope under natural field conditions. The impact of GTXs on run-off and soil loss was investigated to compare the performance of GTXs under different conditions. Laboratory run-off ratio (percentage portion of control plot) equalled 78, 83, and 91 %, while peak discharge ratio equalled 83, 91, and 97 % for J500, C700, and C400 respectively. In the field, a run-off ratio of 31, 62, and 79 %, and peak discharge ratio of 37, 74, and 87 % were recorded for C700, J500, and C400 respectively. All tested GTXs significantly decreased soil erosion. The greatest soil loss reduction in the field was observed for J500 (by 99.4 %), followed by C700 (by 97.9 %) and C400 (by 93.8 %). Irrespective of slope gradient or experimental condition, C400 performed with lower run-off and peak discharge reduction than J500 and C700. The performance ranking of J500 and C700 in the laboratory differed from the field, which may be explained by different slope gradients, and also by the role of soil, which was not included in the laboratory experiment.

  8. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1985-01-01

    Radio absorptivity data for the Venus middle atmosphere (1 to 6 atm, temperatures from 500 to 575K) obtained from spacecraft radio occultation experiments (at 3.6 to 13.4 cm wavelengths) and earth-based radio astronomical observations (1 to 3 cm wavelength range) are compared to laboratory observations at the latter wavelength range under simulated Venus conditions to infer abundances of microwave-absorbing atmospheric constituents, i.e. H2SO4 in a CO2 atmosphere.

  9. Feeding and breeding aspects of Pseudolynchia canariensis (Macquart, 1839) (Diptera, Hippoboscidae) under laboratory conditions.

    PubMed

    Arcoverde, Alessandro Roberto; Rodrigues, André Flávio Soares Ferreira; Daemon, Erik

    2009-01-01

    This study was aimed at making the bionomic aspects of Pseudolynchia canariensis (Macquart 1839) clear and at providing ways for keeping this diptera under laboratory conditions. A hundred and seventy-four flies were collected, of which 30% did not show hematophagy under laboratory conditions. The others were split into two groups with feeding intervals of 24 and 48 h. The individuals fed within a 24-h interval were found to live longer than the ones fed within a 48-h interval and blood meal time was decreased as feeding interval was increased. In the 48-h-feeding-interval group, females were found to live longer than the males, what could not be shown for the 24-h-feeding-interval group. Copulation was not observed in vitro, even after exposure to pigeon feathers and scraped skin. Data from this study suggest that daily feeding makes it possible to keep P. canariensis under laboratory conditions for a period of time longer than the one found for the 48-h feeding interval.

  10. Extreme temperatures increase the deleterious consequences of inbreeding under laboratory and semi-natural conditions.

    PubMed

    Kristensen, Torsten N; Barker, J Stuart F; Pedersen, Kamilla S; Loeschcke, Volker

    2008-09-07

    The majority of experimental studies of the effects of population bottlenecks on fitness are performed under laboratory conditions, which do not account for the environmental complexity that populations face in nature. In this study, we test inbreeding depression in multiple replicates of inbred when compared with non-inbred lines of Drosophila melanogaster under different temperature conditions. Egg-to-adult viability, developmental time and sex ratio of emerging adults are studied under low, intermediate and high temperatures under laboratory as well as semi-natural conditions. The results show inbreeding depression for egg-to-adult viability. The level of inbreeding depression is highly dependent on test temperature and is observed only at low and high temperatures. Inbreeding did not affect the developmental time or the sex ratio of emerging adults. However, temperature affected the sex ratio with more females relative to males emerging at low temperatures, suggesting that selection against males in pre-adult life stages is stronger at low temperatures. The coefficient of variation (CV) of egg-to-adult viability within and among lines is higher for inbred flies and generally increases at stressful temperatures. Our results contribute to knowledge on the environmental dependency of inbreeding under different environmental conditions and emphasize that climate change may impact negatively on fitness through synergistic interactions with the genotype.

  11. Enteropathogenic Escherichia coli protein secretion is induced in response to conditions similar to those in the gastrointestinal tract.

    PubMed Central

    Kenny, B; Abe, A; Stein, M; Finlay, B B

    1997-01-01

    The pathogenicity of enteropathogenic Escherichia coli (EPEC) is associated with the expression and secretion of specific bacterial factors. EspB is one such secreted protein which is required to trigger host signaling pathways resulting in effacement of microvilli and cytoskeletal rearrangements. These events presumably contribute to the ensuing diarrhea associated with EPEC infections. EPEC encounters several environmental changes and stimuli during its passage from the external environment into the host gastrointestinal tract. In this paper we show that the secretion of EspB is subject to environmental regulation, and maximal secretion occurs under conditions reminiscent of those in the gastrointestinal tract. Thus, secretion is maximal at 37 degrees C, pH 7, and physiological osmolarity. In addition, maximal secretion requires the presence of sodium bicarbonate and calcium and is stimulated by millimolar concentrations of Fe(NO3)3. The secretion of the four other EPEC-secreted proteins appears to be modulated in a manner similar to that of EspB. Our results also show that secretion is not dependent on CO2, as originally reported by Haigh et al. (FEMS Microbiol. Lett. 129: 63-67, 1995), but that CO2 more likely acts as a component of the medium buffering system, since CO2 dependence was abolished by the use of alternative buffers. PMID:9199427

  12. Laboratory simulations of acid-sulfate weathering under volcanic hydrothermal conditions: Implications for early Mars

    PubMed Central

    Marcucci, Emma C; Hynek, Brian M

    2014-01-01

    We have completed laboratory experiments and thermochemical equilibrium models to investigate secondary mineral formation under conditions akin to volcanic, hydrothermal acid-sulfate weathering systems. Our research used the basaltic mineralogy at Cerro Negro Volcano, Nicaragua, characterized by plagioclase, pyroxene, olivine, and volcanic glass. These individual minerals and whole-rock field samples were reacted in the laboratory with 1 molal sulfuric acid at varying temperatures (65, 150, and 200°C), fluid:rock weight ratios (1:1, 4:1, and 10:1), and durations (1–60 days). Thermochemical equilibrium models were developed using Geochemist's Workbench. To understand the reaction products and fluids, we employed scanning electron microscopy/energy dispersive spectroscopy, X-ray diffraction, and inductively coupled plasma-atomic emission spectroscopy. The results of our experiments and models yielded major alteration minerals that include anhydrite, natroalunite, minor iron oxide, and amorphous Al-Si gel. We found that variations in experimental parameters did not drastically change the suite of minerals produced; instead, abundance, size, and crystallographic shape changed. Our results also suggest that it is essential to separate phases formed during experiments from those formed during fluid evaporation to fully understand the reaction processes. Our laboratory reacted and model predicted products are consistent with the mineralogy observed at places on Mars. However, our results indicate that determination of the formation conditions requires microscopic imagery and regional context, as well as a thorough understanding of contributions from both experiment precipitation and fluid evaporation minerals. PMID:26213665

  13. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1988-01-01

    In the first half of this grant year, laboratory measurements were conducted on the millimeter-wave properties of atmospheric gases under simulated conditions for the outer planet. Significant improvements in the current system have made it possible to accurately characterize the opacity from gaseous NH3 at longer millimeter wavelengths (7 to 10 mm) under simulated Jovian conditions. In the second half of the grant year, it is hoped to extend such measurements to even shorter millimeter-wavelengths. Further analysis and application of the laboratory results to microwave and millimeter-wave absorption data for the outer planets, such as results from Voyager Radio Occultation experiments and earth-based radio astronomical observations will be continued. The analysis of available multispectral microwave opacity data from Venus, including data from the most recent radio astronomical ovservations in the 1.3 to 3.6 cm wavelength range and newly obtained Pioneer-Venus Radio Occulatation measurements at 13 cm, using the laboratory measurements as an interpretative tool will be pursued.

  14. Laboratory Evaluation and Application of Microwave Absorption Properties Under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1997-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurements completed under this grant (NAGW-533), have shown that the opacity from, SO2 under simulated Venus conditions is best described by a different lineshape than was previously used in theoretical predictions. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  15. Consequences of keeping Mytilus in the laboratory as assessed by different cellular condition indices

    NASA Astrophysics Data System (ADS)

    Cajaraville, M. P.; Díez, G.; Marigómez, I. A.; Angulo, E.

    1991-12-01

    Mytilus galloprovincialis Lmk. were maintained in the laboratory for three months in a semicontinuous water flow system. Animals were fed a commercial filter-feeder food and sampled after 0, 21, 35, 49, 77, and 91 days. In order to establish whether laboratory conditions and the food used were deleterious to mussels, their health status was assessed by quantifying different histological parameters of the digestive gland tissue. It was concluded that mussels kept for more than 35 days under the described laboratory conditions showed signs of stress presumably caused by the reproductive state of the mussels investigated. The food used and the nutrition-related health status of the animals were adequate, as shown by transmission electron microscopical studies after the 91-day maintenance period. A stress response was also evoked by a 10-day starvation period, which was reflected by an increased proportion of type I and type IV digestive tubules, and a reduced “Mean Epithelial Thickness” (MET). Finally, the results demonstrate the sensitivity of quantitative histological diagnosis in comparison to subjective tubule grading procedures in the assessment of the degree of stress experienced by mussels.

  16. Laboratory simulations of acid-sulfate weathering under volcanic hydrothermal conditions: Implications for early Mars.

    PubMed

    Marcucci, Emma C; Hynek, Brian M

    2014-03-01

    We have completed laboratory experiments and thermochemical equilibrium models to investigate secondary mineral formation under conditions akin to volcanic, hydrothermal acid-sulfate weathering systems. Our research used the basaltic mineralogy at Cerro Negro Volcano, Nicaragua, characterized by plagioclase, pyroxene, olivine, and volcanic glass. These individual minerals and whole-rock field samples were reacted in the laboratory with 1 molal sulfuric acid at varying temperatures (65, 150, and 200°C), fluid:rock weight ratios (1:1, 4:1, and 10:1), and durations (1-60 days). Thermochemical equilibrium models were developed using Geochemist's Workbench. To understand the reaction products and fluids, we employed scanning electron microscopy/energy dispersive spectroscopy, X-ray diffraction, and inductively coupled plasma-atomic emission spectroscopy. The results of our experiments and models yielded major alteration minerals that include anhydrite, natroalunite, minor iron oxide, and amorphous Al-Si gel. We found that variations in experimental parameters did not drastically change the suite of minerals produced; instead, abundance, size, and crystallographic shape changed. Our results also suggest that it is essential to separate phases formed during experiments from those formed during fluid evaporation to fully understand the reaction processes. Our laboratory reacted and model predicted products are consistent with the mineralogy observed at places on Mars. However, our results indicate that determination of the formation conditions requires microscopic imagery and regional context, as well as a thorough understanding of contributions from both experiment precipitation and fluid evaporation minerals.

  17. Laboratory simulations of acid-sulfate weathering under volcanic hydrothermal conditions: Implications for early Mars

    NASA Astrophysics Data System (ADS)

    Marcucci, Emma C.; Hynek, Brian M.

    2014-03-01

    We have completed laboratory experiments and thermochemical equilibrium models to investigate secondary mineral formation under conditions akin to volcanic, hydrothermal acid-sulfate weathering systems. Our research used the basaltic mineralogy at Cerro Negro Volcano, Nicaragua, characterized by plagioclase, pyroxene, olivine, and volcanic glass. These individual minerals and whole-rock field samples were reacted in the laboratory with 1 molal sulfuric acid at varying temperatures (65, 150, and 200°C), fluid:rock weight ratios (1:1, 4:1, and 10:1), and durations (1-60 days). Thermochemical equilibrium models were developed using Geochemist's Workbench. To understand the reaction products and fluids, we employed scanning electron microscopy/energy dispersive spectroscopy, X-ray diffraction, and inductively coupled plasma-atomic emission spectroscopy. The results of our experiments and models yielded major alteration minerals that include anhydrite, natroalunite, minor iron oxide, and amorphous Al-Si gel. We found that variations in experimental parameters did not drastically change the suite of minerals produced; instead, abundance, size, and crystallographic shape changed. Our results also suggest that it is essential to separate phases formed during experiments from those formed during fluid evaporation to fully understand the reaction processes. Our laboratory reacted and model predicted products are consistent with the mineralogy observed at places on Mars. However, our results indicate that determination of the formation conditions requires microscopic imagery and regional context, as well as a thorough understanding of contributions from both experiment precipitation and fluid evaporation minerals.

  18. Hydrochemical differences between Carpathian streams with similar physico-geographical conditions of catchments (the Polish Flysch Carpathians)

    NASA Astrophysics Data System (ADS)

    Bucała, Anna; Wiejaczka, Łukasz

    2014-05-01

    The study was conducted during one hydrological year (2012/2013) in two Jaszcze and Jamne catchments (11.39 km2 and 8.95 km2, respectively) located in the Gorce Mountains with environmental features representative for the Western Flysch Carpathians (in 2012/2013 hydrological year). The Jaszcze and Jamne streams (9.3 km and 6.4 km long, respectively), are left tributaries of the Ochotnica river. Both catchments are in the range of the Magura nappe of the Carpathian Flysch. The Jaszcze and Jamne valleys are located in two climatic vertical zones: 1) a temperate cold zone (of a mean annual temperature of 4-6 ºC) and 2) a cold zone (2-4ºC), above 1,100 m a.s.l. Mean annual precipitation for this region in the years 1958-2008 was 841 mm. The aim of the research was to determine differences in the physicochemical properties between streams, the valleys of which are characterised by similar physico-geographical conditions. The discussed valleys are alike because of their proximity, and the similarity manifests itself through the occurrence of the same geology, relief and exposure of both valleys, as well as inclination and soil cover. The climatic conditions and circulation of groundwater are also similar. In both valleys, forest is the dominant land use form (the Jaszcze catchment - 77% and the Jamne - 55%). The research showed that the Jaszcze stream is characterised by a higher discharge throughout the year than the Jamne stream. In spring, the mean water flow rate calculated for the entire longitudinal profile of the Jaszcze stream was 1.6 times higher than the rate obtained for the Jamne stream. In summer and autumn, this rate was respectively 1.8 and 2.2 times higher in the Jaszcze stream than in the Jamne stream. The mean annual temperature of water in the Jamne stream is higher by 0.8 °C than the temperature of water in the Jaszcze stream. This is caused by the higher temperature of groundwater (even by up to 2-3 °C) and the lower discharge (the temperature

  19. Unification and extension of the similarity scaling criteria and mixing transition for studying astrophysics using high energy density laboratory experiments or numerial simulations

    SciTech Connect

    Zhou, Y

    2006-08-21

    The Euler similarity criteria for laboratory experiments and time-dependent mixing transition are important concepts introduced recently for application to prediction and analysis of astrophysical phenomena. However Euler scaling by itself provides no information on the distinctive spectral range of high Reynolds number turbulent flows found in astrophysics situations. On the other hand, time-dependent mixing transition gives no indication on whether a flow that just passed the mixing transition is sufficient to capture all of the significant dynamics of the complete astrophysical spectral range. In this paper, a new approach, based on additional insight gained from review of Navier-Stokes turbulence theory, is developed. It allows for revelations about the distinctive spectral scale dynamics associated with high Reynolds number astrophysical flows. From this perspective, we caution that the energy containing range of the turbulent flow measured in a laboratory setting must not be unintentionally contaminated in such a way that the interactive influences of this spectral scale range in the corresponding astrophysical situation cannot be faithfully represented. In this paper we introduce the concept of a minimum state as the lowest Reynolds number turbulent flow that a time-dependent mixing transition must achieve to fulfill this objective. Later in the paper we show that the Reynolds number of the minimum state may be determined as 1.6 x 10{sup 5}. Our efforts here can be viewed as a unification and extension of the concepts of both similarity scaling and transient mixing transition concepts. At the last the implications of our approach in planning future intensive laser experiments or massively parallel numerical simulations are discussed. A systematic procedure is outlined so that as the capabilities of the laser interaction experiments and supporting results from detailed numerical simulations performed in recently advanced supercomputing facilities increase

  20. Evaluation of Cyantraniliprole and Other Commercial Fly Baits under Laboratory and Field Conditions

    PubMed Central

    Parker, Casey; Baldwin, Rebecca; Pereira, Roberto; Koehler, Philip

    2015-01-01

    Laboratory and field trials were performed to evaluate the attractiveness and efficacy of commercial baits (cyantraniliprole; methomyl + (Z)-9-tricosene; dinotefuran + (Z)-9-tricosene; imidacloprid granular + (Z)-9-tricosene; and imidacloprid liquid + (Z)-9-tricosene). In choice tests; flies were most attracted to cyantraniliprole bait > dinotefuran + (Z)-9 > methomyl + (Z)-9 bait > imidacloprid granular + (Z)-9 bait > imidacloprid liquid + (Z)-9 bait. Significant degradation in bait efficacy was observed after two weeks of aging excluding imidacloprid granular; which began to degrade in field conditions after one week. Cyantraniliprole; the new fly bait active ingredient in Zyrox®; had the longest time to knockdown in the laboratory tests; but on susceptible flies; achieved 95%–100% knockdown within an hour of exposure. Zyrox® was resistant to weathering for a week; and was more attractive to flies in the field when compared to methomyl + (Z)-9 bait. PMID:26610575

  1. The impact of standard preparation practice on the runoff and soil erosion rates under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Khaledi Darvishan, Abdulvahed; Homayounfar, Vafa; Hamidreza Sadeghi, Seyed

    2016-09-01

    The use of laboratory methods in soil erosion studies, rainfall simulation experiments, Gerlach troughs, and other measurements such as ring infiltrometer has been recently considered more and more because of many advantages in controlling rainfall properties and high accuracy of sampling and measurements. However, different stages of soil removal, transfer, preparation and placement in laboratory plots cause significant changes in soil structure and, subsequently, the results of runoff, sediment concentration and soil loss. Knowing the rate of changes in sediment concentration and soil loss variables with respect to the soil preparation for laboratory studies is therefore inevitable to generalize the laboratory results to field conditions. However, there has been little attention given to evaluate the effects of soil preparation on sediment variables. The present study was therefore conducted to compare sediment concentration and soil loss in natural and prepared soil. To achieve the study purposes, 18 field 1 × 1 m plots were adopted in an 18 % gradient slope with sandy-clay-loam soil in the Kojour watershed, northern Iran. A portable rainfall simulator was then used to simulate rainfall events using one or two nozzles of BEX: 3/8 S24W for various rainfall intensities with a constant height of 3 m above the soil surface. Three rainfall intensities of 40, 60 and 80 mm h-1 were simulated on both prepared and natural soil treatments with three replications. The sediment concentration and soil loss at five 3 min intervals after time to runoff were then measured. The results showed the significant increasing effects of soil preparation (p ≤ 0.01) on the average sediment concentration and soil loss. The increasing rates of runoff coefficient, sediment concentration and soil loss due to the study soil preparation method for laboratory soil erosion plots were 179, 183 and 1050 % (2.79, 2.83 and 11.50 times), respectively.

  2. Interoceptive conditioning with the nicotine stimulus: extinction learning as a method for assessing stimulus similarity across doses.

    PubMed

    Polewan, Robert J; Savala, Stephanie A; Bevins, Rick A

    2013-02-01

    Interoceptive conditioning involving the nicotine stimulus likely contributes to chronic tobacco use. To better understand the nature of this interoceptive conditioning, we compared generalization during repeated extinction with generalization in a 'transfer of extinction' test using a wide range of test doses. Rats were first trained in the discriminated goal-tracking task in which nicotine (0.2 or 0.4 mg/kg), but not saline, was paired with repeated intermittent access to sucrose. Across sessions, nicotine acquired control of approach behavior directed at the location of previous sucrose deliveries. Extinction followed with eight 20-min sessions without sucrose access; extinction doses of nicotine ranged from 0.05 to 0.6 mg/kg. In rats trained with 0.4 mg/kg, the 0.1, 0.2, and 0.6 mg/kg doses evoked comparable responding across extinction sessions; substitution was only partial at 0.05 and 0.075 mg/kg (i.e. above saline controls, but less than the training dose). With the 0.2 mg/kg training dose, complete generalization was seen only at the 0.1 and 0.4 mg/kg doses. After extinction, rats were given a transfer test with their training dose. Rats trained with 0.4 mg/kg showed full transfer of extinction learning with 0.1, 0.2, and 0.6 mg/kg (i.e. responding comparable with extinction with the training dose). Partial transfer was observed at 0.075 mg/kg. With the 0.2 mg/kg nicotine dose, only 0.4 mg/kg fully generalized; 0.075, 0.1, and 0.6 mg/kg showed partial transfer. Extinction with 0.05 mg/kg dose did not show transfer to either training dose. These findings indicated that conclusions regarding stimulus similarity across nicotine doses can vary with testing protocol.

  3. The effects of changing deposition conditions on the similarity of sputter-deposited fluorocarbon thin films to bulk PTFE

    NASA Astrophysics Data System (ADS)

    Zandona, Philip

    Solid lubrication of space-borne mechanical components is essential to their survival and the continued human exploration of space. Recent discoveries have shown that PTFE when blended with alumina nanofillers exhibits greatly improved physical performance properties, with wear rates being reduced by several orders of magnitude. The bulk processes used to produce the PTFE-alumina blends are limiting. Co-sputter deposition of PTFE and a filler material overcomes several of these limitations by enabling the reduction of particle size to the atomic level and also by allowing for the even coating of the solid lubricant on relatively large areas and components. The goal of this study was to establish a baseline performance of the sputtered PTFE films as compared to the bulk material, and to establish deposition conditions that would result in the most bulk-like film possible. In order to coax change in the structure of the sputtered films, sputtering power and deposition temperature were increased independently. Further, post-deposition annealing was applied to half of the deposited film in an attempt to affect change in the film structure. Complications in the characterization process due to increasing film thickness were also examined. Bulk-like metrics for characterization processes the included Fourier transform infrared spectroscopy (FTIR), X-ray spectroscopy (XPS), nanoindentation via atomic force microscopy, and contact angle of water on surface measurements were established. The results of the study revealed that increasing sputtering power and deposition temperature resulted in an increase in the similarity between the fluorocarbon films and the bulk PTFE, at a cost of affecting the potential of the film thicknesses, either by affecting the deposition process directly, or by decreasing the longevity of the sputtering targets.

  4. Crystallization of a three-dimensional complex plasma under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Steinmüller, B.; Dietz, C.; Kretschmer, M.; Thoma, M. H.

    2017-03-01

    The influence of neutral gas pressure for crystallization of cylindrical complex plasmas under laboratory conditions is investigated. For the analysis of the complex plasma structure, different methods are adopted: First, the pair correlation and a criterion based on the shape of the Voronoi cells are applied. Besides this, a new implementation, which connects the Minkowski structure metric with the benefits from the scalar product of the local bond order parameter, is presented. In addition, the bcc sensitive Minkowski structure metric is used to identify the crystalline structures. All criteria display the same behavior: Decreasing the neutral pressure leads to crystallization. This is the opposite behavior to that observed in former ground based experiments.

  5. Scaling methane oxidation: from laboratory incubation experiments to landfill cover field conditions.

    PubMed

    Abichou, Tarek; Mahieu, Koenraad; Chanton, Jeff; Romdhane, Mehrez; Mansouri, Imane

    2011-05-01

    Evaluating field-scale methane oxidation in landfill cover soils using numerical models is gaining interest in the solid waste industry as research has made it clear that methane oxidation in the field is a complex function of climatic conditions, soil type, cover design, and incoming flux of landfill gas from the waste mass. Numerical models can account for these parameters as they change with time and space under field conditions. In this study, we developed temperature, and water content correction factors for methane oxidation parameters. We also introduced a possible correction to account for the different soil structure under field conditions. These parameters were defined in laboratory incubation experiments performed on homogenized soil specimens and were used to predict the actual methane oxidation rates to be expected under field conditions. Water content and temperature corrections factors were obtained for the methane oxidation rate parameter to be used when modeling methane oxidation in the field. To predict in situ measured rates of methane with the model it was necessary to set the half saturation constant of methane and oxygen, K(m), to 5%, approximately five times larger than laboratory measured values. We hypothesize that this discrepancy reflects differences in soil structure between homogenized soil conditions in the lab and actual aggregated soil structure in the field. When all of these correction factors were re-introduced into the oxidation module of our model, it was able to reproduce surface emissions (as measured by static flux chambers) and percent oxidation (as measured by stable isotope techniques) within the range measured in the field.

  6. Scaling methane oxidation: From laboratory incubation experiments to landfill cover field conditions

    SciTech Connect

    Abichou, Tarek; Mahieu, Koenraad; Chanton, Jeff; Romdhane, Mehrez; Mansouri, Imane

    2011-05-15

    Evaluating field-scale methane oxidation in landfill cover soils using numerical models is gaining interest in the solid waste industry as research has made it clear that methane oxidation in the field is a complex function of climatic conditions, soil type, cover design, and incoming flux of landfill gas from the waste mass. Numerical models can account for these parameters as they change with time and space under field conditions. In this study, we developed temperature, and water content correction factors for methane oxidation parameters. We also introduced a possible correction to account for the different soil structure under field conditions. These parameters were defined in laboratory incubation experiments performed on homogenized soil specimens and were used to predict the actual methane oxidation rates to be expected under field conditions. Water content and temperature corrections factors were obtained for the methane oxidation rate parameter to be used when modeling methane oxidation in the field. To predict in situ measured rates of methane with the model it was necessary to set the half saturation constant of methane and oxygen, K{sub m}, to 5%, approximately five times larger than laboratory measured values. We hypothesize that this discrepancy reflects differences in soil structure between homogenized soil conditions in the lab and actual aggregated soil structure in the field. When all of these correction factors were re-introduced into the oxidation module of our model, it was able to reproduce surface emissions (as measured by static flux chambers) and percent oxidation (as measured by stable isotope techniques) within the range measured in the field.

  7. Anaerobic respiration and antioxidant responses of Corythucha ciliata (Say) adults to heat-induced oxidative stress under laboratory and field conditions.

    PubMed

    Ju, Rui-Ting; Wei, He-Ping; Wang, Feng; Zhou, Xu-Hui; Li, Bo

    2014-03-01

    High temperature often induces oxidative stress and antioxidant response in insects. This phenomenon has been well documented under controlled laboratory conditions, but whether it happens under fluctuating field conditions is largely unknown. In this study, we used an invasive lace bug (Corythucha ciliata) as a model species to compare the effects of controlled thermal treatments (2 h at 33-43 °C with 2 °C intervals in the laboratory) and naturally fluctuating thermal conditions (08:00-14:00 at 2-h intervals (29.7-37.2 °C) on a hot summer day in a field in Shanghai, China) on lipid peroxidation (malondialdehyde (MDA) was the marker) and anaerobic respiration (lactate dehydrogenase (LDH) was the marker), as well as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), and glutathione reductase (GR). The results show that MDA concentration increased significantly in response to heat stresses with similar trend in the laboratory and field. LDH activities did not significantly vary across temperatures in the laboratory-exposed individuals, but they significantly increased by rising temperature in the field. The activities or concentrations of SOD, CAT, GSH, and GR all significantly increased with increasing temperature in the two populations. These findings indicate that high temperature induces oxidative stress, resulting in high anaerobic respiration and antioxidant defenses in C. ciliata under both the laboratory and field conditions, which likely provide a defense mechanism against oxidative damage due to the accumulation of ROS.

  8. Laboratory emissivity measurements of the plagioclase solid solution series under varying environmental conditions

    NASA Astrophysics Data System (ADS)

    Donaldson Hanna, K. L.; Thomas, I. R.; Bowles, N. E.; Greenhagen, B. T.; Pieters, C. M.; Mustard, J. F.; Jackson, C. R. M.; Wyatt, M. B.

    2012-11-01

    New laboratory thermal infrared emissivity measurements of the plagioclase solid solution series over the 1700 ˜ 400 cm-1 (6-25 μm) spectral range are presented. Thermal infrared (TIR) spectral changes for fine-particulate samples (0-25 μm) are characterized for the first time under different laboratory environmental conditions: ambient (terrestrial-like), half-vacuum (Mars-like), vacuum, and vacuum with cooled chamber (lunar-like). Under all environmental conditions the Christiansen Feature (CF) is observed to vary in a systematic way with Na-rich end-member (albite) having a CF position at the highest wave number (shortest wavelength) and the Ca-rich end-member (anorthite) having a CF position with the lowest wave number (longest wavelength). As pressure decreases to <10-3 mbar four observations are made: (1) the CF position shifts to higher wave numbers, (2) the spectral contrast of the CF increases relative to the RB, (3) the spectral contrast of the RB in the ˜1200-900 spectral range decreases while the spectral contrast of the RB in the ˜800-400 spectral range either increases or remains the same and (4) the TF disappears. A relationship between the wavelength position of the CF measured under simulated lunar conditions and plagioclase composition (An#) is developed. Although its exact form may evolve with additional data, this linear relationship should be applied to current and future TIR data sets of the Moon. Our new spectral measurements demonstrate how sensitive thermal infrared emissivity spectra of plagioclase feldspars are to the environmental conditions under which they are measured and provide important constraints for interpreting current and future thermal infrared data sets.

  9. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1992-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, laboratory measurements performed by Fahd and Steffes have shown that the opacity from gaseous SO2 under simulated Venus conditions can be well described by the Van Vleck-Weisskopf lineshape at wavelengths shortward of 2 cm, but that the opacity of wavelengths greater than 2 cm is best described by a different lineshape that was previously used in theoretical predictions. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  10. Feeding and breeding aspects of Stomoxys calcitrans (Diptera: Muscidae) under laboratory conditions

    PubMed Central

    Salem, A.; Franc, M.; Jacquiet, P.; Bouhsira, E.; Liénard, E.

    2012-01-01

    Bionomic aspects of Stomoxys calcitrans (Linnaeus, 1758) (Diptera: Muscidae) were studied under laboratory conditions. For this reason, laboratory-rearing techniques were optimized at the National Veterinary School of Toulouse. The colony was maintained at 25 ± 2 °C, 50 ± 10% RH under a 12-hour light cycle and observed daily. The size of each adult cage is 30 x 30 x 30 cm and designed to house about 500-1,000 flies. The average cycle from egg to adult was 19.2 ± 1.7 days. The mean longevity of imagos was 9.3 ± 5.8 days and not significantly different between sexes. Stable flies were split into two groups; the first was fed with blood, honey and water, and the second was fed only with honey and water. The mean weight of a blood meal was 11.1 ± 3.8 mg with no significant differences between males and females. The mean longevity of non-blood fed flies was found to be significantly higher (10.4 ± 3.9 days) than those fed with blood. The maximum lifespan was shorter for non-blood fed males (17 days) and females (18 days) than for those fed with blood (females: 24 days, males: 23 days). Under these laboratory conditions, S. calcitrans rearing was successfully established. In the end, the number of expected generations of S. calcitrans and the net reproduction rate were estimated to be 11.8 generations/year and 16.2 living females per female respectively. PMID:23193515

  11. Laboratory Evaluation and Application of Microwave Absorption Properties Under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1998-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties taken under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. For example, laboratory measurements completed recently by Kolodner and Steffes (ICARUS 132, pp. 151-169, March 1998, attached as Appendix A) under this grant (NAGS-4190), have shown that the opacity from gaseous H2SO4 under simulated Venus conditions is best described by a different formalism than was previously used. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both spacecraft entry probe and orbiter radio occultation experiments and by radio astronomical observations, and over a range of frequencies which correspond to those used in such experiments, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  12. Laboratory Evaluation and Application of Microwave Absorption Properties under Simulated Conditions for Planetary Atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    2002-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments, entry probe radio signal absorption measurements, and earth-based or spacecraft-based radio astronomical (emission) observations can be used to infer abundances of microwave absorbing constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically-derived microwave absorption properties for such atmospheric constituents, or the use of laboratory measurements of such properties taken under environmental conditions that are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. Laboratory measurements have shown that the centimeter-wavelength opacity from gaseous phosphine (PH3) under simulated conditions for the outer planets far exceeds that predicted from theory over a wide range of temperatures and pressures. This fundamentally changed the resulting interpretation of Voyager radio occultation data at Saturn and Neptune. It also directly impacts planning and scientific goals for study of Saturn's atmosphere with the Cassini Radio Science Experiment and the Rossini RADAR instrument. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both spacecraft entry probe and orbiter (or flyby) radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations

  13. Dynamics of genetic variability in Anastrepha fraterculus (Diptera: Tephritidae) during adaptation to laboratory rearing conditions

    PubMed Central

    2014-01-01

    Background Anastrepha fraterculus is one of the most important fruit fly plagues in the American continent and only chemical control is applied in the field to diminish its population densities. A better understanding of the genetic variability during the introduction and adaptation of wild A. fraterculus populations to laboratory conditions is required for the development of stable and vigorous experimental colonies and mass-reared strains in support of successful Sterile Insect Technique (SIT) efforts. Methods The present study aims to analyze the dynamics of changes in genetic variability during the first six generations under artificial rearing conditions in two populations: a) a wild population recently introduced to laboratory culture, named TW and, b) a long-established control line, named CL. Results Results showed a declining tendency of genetic variability in TW. In CL, the relatively high values of genetic variability appear to be maintained across generations and could denote an intrinsic capacity to avoid the loss of genetic diversity in time. Discussion The impact of evolutionary forces on this species during the adaptation process as well as the best approach to choose strategies to introduce experimental and mass-reared A. fraterculus strains for SIT programs are discussed. PMID:25471362

  14. Developmental biology of Argas neghmei Kohls & Hoogstraal (Acari: Argasidae) under laboratory conditions.

    PubMed

    González-Acuña, Daniel; Vargas, Pamela; Ardiles, Karen; Parra, Luis; Guglielmone, Alberto

    2010-01-01

    In order to describe the developmental biology of the tick Argas neghmei Kohls & Hoogstraal under laboratory conditions, 40 females and 40 males were collected from chicken coops located in Calama (II Region, Chile). They were fed on chickens and maintained under two laboratory conditions: one group at 30 +/- 5 degrees C and 35 +/- 5 % RH and another at 27 +/- 5 degrees C and 80 +/- 5 % RH, both at 12: 12 h L:D photoperiod. The ticks were observed daily to determine larval feeding periods, preoviposition, oviposition, egg incubation as well as the frequency of egg laying, number of eggs laid, and percentage of larval hatching. Females did not lay eggs at 80 +/- 5% RH, and data on the biology of this tick was obtained only at 35 +/- 5% RH. The life cycle of A. neghmei lasted an average of 269 days. Feeding period of each nymphal stage as well as of adult females between oviposition events lasted less than a day. Females laid on average 1.8 egg batches and egg-laying period lasted on average 14 days, during which about 96 eggs were laid per female.

  15. The sleep of the baboon, Papio papio, under natural conditions and in the laboratory.

    PubMed

    Bert, J; Balzamo, E; Chase, M; Pegram, V

    1975-12-01

    The sleep pattern of sixteen baboons (Papio papio) was studied under two very different conditions: (1) in a laboratory at Marseilles, the monkey being immobilized in a restraining chair in a soundproof cubicle; (2) in an African reserve, the monkey being housed in a large cage placed in its natural environment. Some very marked differences emerged. Sleep in the laboratory was longer (by 24 min) and richer in stage 3 and paradoxical sleep. In Africa, however, the sleep showed much more stage 1, was more fragmented and stages 2 and 3 and paradoxical sleep episodes were of shorter duration. Records made in Africa indicate that sleep is independent of slight environmental changes (day length, brightness of the moon, variations in temperature, calls of predators). But the comparison of the two series of results reveals the reorganization which occurs when the monkey is exposed to such different conditions. This adaptation to the environment affects, unequally, the various slow sleep stages and paradoxical sleep. In fact, the major modifications occur in stages 1 and 3 of slow sleep and in paradoxical sleep, while stage 2 appears to constitute the stable, unmodifiable nucleus of sleep.

  16. Survival, food consumption and growth of Norway lobster (Nephrops norvegicus) kept in laboratory conditions.

    PubMed

    Mente, Elena

    2010-09-01

    Successful commercial aquaculture of crustacean species is dependent on satisfying their nutritional requirements and on producing rapidly growing and healthy animals. The results of the present study provide valuable information for feeding habits and growth of Nephrops norvegicus L., 1758) under laboratory conditions. The aim of the present study was to examine food consumption, growth and physiology of the Norway lobster N. norvegicus under laboratory conditions. N. norvegicus (15 g wet weight) were distributed into 1001 tanks consisting of five numbered compartments each. They were fed the experimental diets (frozen mussels and pellets) for a period of 6 months. A group of starved Nephrops was stocked and fasted for 8 months. Although Nephrops grew well when fed the frozen mussels diet, feeding on a dry pellet feed was unsatisfactory. The starvation group, despite the fact that showed the highest mortality (50%), exhibited a remarkable tolerance to the lack of food supply. The study offers further insight by correlating the amino acid profiles of Nephrops tail muscle with the two diets. The deviations from the mussel's diet for asparagine, alanine and glutamic acid suggest a deficiency of these amino acids in this diet. The results of the present study showed that the concentrations of free amino acids are lower in relative amount than those of protein-bound amino acids, except for arginine, proline and glycine. The present study contributes to the improvement of our knowledge on nutritional requirements of the above species.

  17. Biodegradation of soluble aromatic compounds of jet fuel under anaerobic conditions: laboratory batch experiments.

    PubMed

    Zheng, Z; Breedveld, G; Aagaard, P

    2001-11-01

    Laboratory batch experiments were performed with contaminated aquifer sediments and four soluble aromatic components of jet fuel to assess their biodegradation under anaerobic conditions. The biodegradation of four aromatic compounds, toluene, o-xylene, 1,2,4-trimethylbenzene (TMB), and naphthalene, separately or together, was investigated under strictly anaerobic conditions in the dark for a period of 160 days. Of the aromatic compounds, toluene and o-xylene were degraded both as a single substrate and in a mixture with the other aromatic compounds, while TMB was not biodegraded as a single substrate, but was biodegraded in the presence of the other aromatic hydrocarbons. Substrate interaction is thus significant in the biodegradation of TMB. Biodegradation of naphthalene was not observed, either as a single substrate or in a mixture of other aromatic hydrocarbons. Although redox conditions were dominated by iron reduction, a clear relation between degradation and sulfate reduction was observed. Methanogenesis took place during the later stages of incubation. However, the large background of Fe(II) masked the increase of Fe(II) concentration due to iron reduction. Thus, although microbial reduction of Fe(III) is an important process, the evidence is not conclusive. Our results have shown that a better understanding of the degradation of complex mixtures of hydrocarbons under anaerobic conditions is important in the application of natural attenuation as a remedial method for soil and groundwater contamination.

  18. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1986-01-01

    After long arduous work with the simulator, measurements of the refractivity and absorptivity of nitrogen under conditions similar to those for Titan were completed. The most significant measurements, however, were those of the microwave absorption from gaseous ammonia under simulated conditions for the Jovian atmospheres over wavelengths from 1.3 to 22 cm. The results of these measurements are critical in that they confirm the theoretical calculation of the ammonia opacity using the Ben-Reuven lineshape. The application of both these results, and results obtained previously, to planetary observations at microwave frequencies were especially rewarding. Applications of the results for ammonia to radio astronomical observations of Jupiter in the 1.3 to 20 cm wavelength range and the application of results for gaseous H2SO4 under simulated Venus conditions are discussed.

  19. The life cycle of the root borer, Oryctes agamemnon, under laboratory conditions.

    PubMed

    Soltani, Rasmi; Chaieb, Ikbel; Ben Hamouda, Med Habib

    2008-01-01

    The root borer, Oryctes agamemnon Burmeister (Coleoptera: Scarabaeidae), has become a serious pest of date palm trees in southwest Tunisia. Under natural conditions, mated females lay eggs in different parts of palm tree: between the hairy roots, all along the stem at the leaf axils and at the base of cut branches. Larvae bore into targeted places of the plant and were never seen outside. Pupation takes place in the plant and emergence of the adults begins in June. Larval feeding causes extensive damage to the respiratory roots. To examine the life cycle more closely, the O. agamemnon life cycle was studied under laboratory conditions. Different larval stages were collected from infested oases in Tozeur and placed in plastic boxes with natural food that was collected from the oases. After emergence, adults were paired in opaque plastic boxes for mating with the same food substrate which also served as an oviposition site. Eggs were collected daily and isolated in new boxes. Hatched eggs were recorded. The number of larval instars was determined by measuring the width of cephalic capsules. Under laboratory conditions (23 +/- 2'C and 55 +/- 6% RH)embryogenesis took 14.3 +/- 1.42 days and the first, second and third larval instars were 33.1 +/- 2.69, 63.88 +/- 6.6 and 118.3 +/- 13.38 days respectively. The pupal period lasted 24.1 +/- 3.02 days and the adult 65.27 +/- 9.48 days. These facts indicated that O. agamemnon is univoltine.

  20. Effects of Multiple Contexts and Context Similarity on the Renewal of Extinguished Conditioned Behaviour in an ABA Design with Humans

    ERIC Educational Resources Information Center

    Balooch, Siavash Bandarian; Neumann, David L.

    2011-01-01

    The ABA renewal procedure involves pairing a conditional stimulus (CS) and an unconditional stimulus (US) in one context (A), presenting extinction trials of the CS alone in a second context (B), and nonreinforced test trials of the CS in the acquisition context (A). The renewal of extinguished conditioned behaviour is observed during test. The…

  1. Structure of high-molecular carbonaceous compound in carbonaceous chondrites and formation of IR-spectroscopically similar compounds in the laboratory

    NASA Astrophysics Data System (ADS)

    Murae, T.

    1997-05-01

    Main components of carbonaceous matter in carbonaceous chondrites are high molecular organic matter. Examinations of the compounds using pyrolysis GC/MS and FT-IR indicated the structural resemblance of major part of the molecule for all of the compounds from different types of carbonaceous chondrites (8 Antarctic and 2 none-Antarctic meteorites). A carbonaceous matter derived from graphite on a shock experiment using a rail gun (1g projectile at 7 km/s) showed similar IR spectrum to those of the meteoritic high-molecular organic matter. C-60 fulleren also gave a similar compound (with minor differences in IR spectra) on a shock experiment under the same conditions. A shock experiment using coronene also examined.

  2. Conditioned Attraction, Similarity, and Evaluative Meaning. Language, Personality, Social, and Cross-Cultural Study and Measurement of the Human A-R-D (Motivational) System.

    ERIC Educational Resources Information Center

    Stalling, Richard B.

    Recent stimulus-response formulations have indicated that similarity between persons functions as an unconditioned stimulus (UCS) and that interpersonal attraction is a classically conditioned evaluative response. The thesis of this study is that similarity is a correlate of evaluative meaning and that the latter rather than the former is…

  3. A laboratory study of the nucleation kinetics of nitric acid hydrates under stratospheric conditions

    NASA Astrophysics Data System (ADS)

    James, Alexander D.; Murray, Benjamin J.; Plane, John M. C.

    2016-04-01

    Measurements of the kinetics of crystallisation of ternary H2O-H2SO4-HNO3 mixtures to produce nitric acid hydrate phases, as occurs in the lower stratosphere, have been a long-standing challenge for investigators in the laboratory. Understanding polar stratospheric chlorine chemistry and thereby ozone depletion is increasingly limited by descriptions of nucleation processes. Meteoric smoke particles have been considered in the past as heterogeneous nuclei, however recent studies suggest that these particles will largely dissolve, leaving mainly silica and alumina as solid inclusions. In this study the nucleation kinetics of nitric acid hydrate phases have been measured in microliter droplets at polar stratospheric cloud (PSC) temperatures, using a droplet freezing assay. A clear heterogeneous effect was observed when silica particles were added. A parameterisation based on the number of droplets activated per nuclei surface area (ns) has been developed and compared to global model data. Nucleation experiments on identical droplets have been performed in an X-Ray Diffractometer (XRD) to determine the nature of the phase which formed. β-Nitric Acid Trihydrate (NAT) was observed alongside a mixture of Nitric Acid Dihydrate (NAD) phases. It is not possible to determine whether NAT nucleates directly or is formed by a phase transition from NAD (likely requiring the presence of a mediating liquid phase). Regardless, these results demonstrate the possibility of forming NAT on laboratory timescales. In the polar stratosphere, sulfuric acid (present at several weight percent of the liquid under equilibrium conditions) could provide such a liquid phase. This study therefor provides insight into previous discrepancies between phases formed in the laboratory and those observed in the atmosphere. It also provides a basis for future studies into atmospheric nucleation of solid PSCs.

  4. Residual bioassay to assess the toxicity of Acaricides against Aceria guerreronis (Acari: Eriophyidae) under laboratory conditions.

    PubMed

    Monteiro, Vaneska B; Lima, Debora B; Gondim, Manoel G C; Siqueira, Herbert A A

    2012-08-01

    Aceria guerreronis Keifer (Acari: Eriophyidae) is considered a major pest of the coconut (Cocos nucifera L.), and the use of pesticides is the current method to control it. However, no standard toxicological tests exist to select and assess the efficiency of molecules against the coconut mite. The aim of this study was to develop a methodology that allows for the evaluation of the relative toxicity of acaricides to A. guerreronis through rapid laboratory procedures. We confined A. guerreronis on arenas made out of coconut leaflets and tested two application methods: immersing the leaf fragments in acaricides and spraying acaricides on the leaf fragments under a Potter spray tower. In the latter application method, we sprayed leaf fragments both populated with and devoid of mites. We evaluated the comparative toxicity of two populations (Itamaracá and Petrolina, Pernambuco, Brazil) by spraying on leaflets without mites and submitted the mortality data to probit analysis after 24 h of exposure. No difference was observed in the LC50, regardless of whether the leaflets were immersed or sprayed with acaricide (abamectin, chlorfenapyr or fenpyroximate). The toxicity of chlorfenapyr and fenpyroximate did not differ, irrespective of whether it was applied directly to the leaflet or to the mite; however, the toxicity of abamectin was higher when applied directly to the mite. Chlorpyrifos and abamectin toxicities were lower for the Petrolina population than for the Itamaracá population. Immersing and spraying coconut leaflets can be used to assess the mortality of A. guerreronis under laboratory conditions.

  5. Repellency of aerosol and cream products containing fennel oil to mosquitoes under laboratory and field conditions.

    PubMed

    Kim, Soon-Il; Chang, Kyu-Sik; Yang, Young-Cheol; Kim, Byung-Seok; Ahn, Young-Joon

    2004-11-01

    The repellency of fennel (Foeniculum vulgare Miller)-containing products (5% aerosol and 8% cream) against mosquitoes was compared with those of citronella oil, geranium oil and deet, as well as three commercial repellents, Baby Keeper cream containing IR3535, MeiMei cream containing citronella and geranium oils, and Repellan S aerosol containing 19% N,N-diethyl-m-toluamide (deet) under laboratory and field conditions. In a laboratory study with female Aedes aegypti (L), fennel oil exhibited good repellency in a release-in-cage test and repellency in skin and patch tests of the oil was comparable with those of citronella and geranium oils. In paddy field tests with five human volunteers, 5% and 8% fennel oil-containing aerosol and cream produced 84% and 70% repellency, respectively, at 90 min after exposure, whereas Baby Keeper cream and MeiMei cream gave 71% and 57% repellency at 90 min after exposure, respectively, and Repellan S aerosol gave 89% repellency at 210 min. The species and ratio of mosquitoes collected were the genera Culex (44.1%), Anopheles (42.2%), Aedes (7.8%) and Armigeres (5.9%). Fennel oil-containing products could be useful for protection from humans and domestic animals from vector-borne diseases and nuisance caused by mosquitoes.

  6. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1992-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The use of theoretically derived microwave absorption properties for such atmospheric constituents, or using laboratory measurements of such properties under environmental conditions which are significantly different than those of the planetary atmosphere being studied, often leads to significant misinterpretation of available opacity data. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. The goal of this investigation was to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  7. Testing shields in the Argonne National Laboratory fuel conditioning facility support areas.

    PubMed

    Courtney, J C; Klann, R T

    1997-01-01

    Testing has been completed for two lightly shielded areas that support operations in the Fuel Conditioning Facility at the Argonne National Laboratory site at the Idaho National Engineering Laboratory. Operational requirements dictated the use of a radiography source containing 0.44 TBq (12 Ci) of 192Ir to challenge reinforced concrete and steel shields that surround a decontamination, maintenance, and repair area for contaminated equipment used in hot cell operations. A more intense source containing 0.89 TBq (24 Ci) of 192Ir was used to test lead shot and steel shields around tanks in a radioactive liquid waste system and the boundaries of the room that contained it. Measurement procedures were developed to find design flaws and construction deficiencies while minimizing radiation exposure to test participants. While the shields are adequate to limit gamma ray deep dose equivalents to 10 mSv y(-1) (1 rem y(-1)) or less to facility personnel, several modifications were necessary to assure that the attenuation is adequate to keep dose rates less than 5 microSv h(-1) (0.5 mrem h(-1)) in normally occupied areas.

  8. Effect of Three Entomopathogenic Fungi on Three Species of Stingless Bees (Hymenoptera: Apidae) Under Laboratory Conditions.

    PubMed

    Toledo-Hernández, R A; Ruíz-Toledo, J; Toledo, J; Sánchez, D

    2016-05-04

    Development of alternative strategies for pest control with reduced effect on beneficial organisms is a priority given the increasing global loss of biodiversity. Biological control with entomopathogenic fungi arises as a viable option to control insect pests. However, few studies have focused on the consequences of using these organisms on pollinators other than the honey bee (Apis mellifera L.) or bumble bees (Bombus spp). We evaluated the pathogenicity of commercial formulations of three widely used entomopathogenic fungi, Metarhizium anisopliae (Metschnikoff) Sorokin, Beauveria bassiana Vuillemin, and Isaria fumosorosea (Wize), to three species of stingless bees: Tetragonisca angustula Latreille, Scaptotrigona mexicana Guérin-Meneville, and Melipona beecheii Bennett. Bioassays consisted of exposing groups of bees to the recommended field concentration of each fungus using a microspray tower under laboratory conditions. Susceptibility to fungi varied greatly among species. Isaria fumosorosea (strain Ifu-lu 01) and the two formulations of B. bassiana (Bea-TNK and BotanicGard) caused <30.3% mortality in all bee species. Metarhizium anisopliae (Meta-TNK and strain Ma-lu 01) was highly active against T. angustula (94.2% mortality) and moderately active against M. beecheii (53.0% mortality) and S. mexicana (38.9% mortality). Though our laboratory-derived results suggest a moderate to high impact of these entomopathogenic fungi on stingless bees, further field studies are required to support this finding.

  9. A Comprehensive Subcellular Proteomic Survey of Salmonella Grown under Phagosome-Mimicking versus Standard Laboratory Conditions

    SciTech Connect

    Brown, Roslyn N.; Sanford, James A.; Park, Jea H.; Deatherage, Brooke L.; Champion, Boyd L.; Smith, Richard D.; Heffron, Fred; Adkins, Joshua N.

    2012-06-01

    Towards developing a systems-level pathobiological understanding of Salmonella enterica, we performed a subcellular proteomic analysis of this pathogen grown under standard laboratory and infection-mimicking conditions in vitro. Analysis of proteins from cytoplasmic, inner membrane, periplasmic, and outer membrane fractions yielded coverage of over 30% of the theoretical proteome. Confident subcellular location could be assigned to over 1000 proteins, with good agreement between experimentally observed location and predicted/known protein properties. Comparison of protein location under the different environmental conditions provided insight into dynamic protein localization and possible moonlighting (multiple function) activities. Notable examples of dynamic localization were the response regulators of two-component regulatory systems (e.g., ArcB, PhoQ). The DNA-binding protein Dps that is generally regarded as cytoplasmic was significantly enriched in the outer membrane for all growth conditions examined, suggestive of moonlighting activities. These observations imply the existence of unknown transport mechanisms and novel functions for a subset of Salmonella proteins. Overall, this work provides a catalog of experimentally verified subcellular protein location for Salmonella and a framework for further investigations using computational modeling.

  10. Redox conditions and the efficiency of chlorinated ethene biodegradation: Laboratory studies

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.

    2000-01-01

    The potential for biodegradation of highly reduced groundwater contaminants is greatest under aerobic conditions and least under CO2-reducing (methanogenic) conditions. Laboratory studies conducted using [1,2-14C] vinyl chloride (VC) indicate the same pattern applies to the anaerobic oxidation of relatively reduced chloroethylenes. Recent studies, showing that CH4 can be a significant product of microbial degradation of VC under methanogenic conditions, clarified mechanisms underlying anaerobic VC mineralization and emphasized the redox dependence of this process. A microcosm study conducted with stream bed sediments demonstrated rapid degradation of [1,2-14C] VC and simultaneous production of 14CO2 and 14CH4. The results of acetate mineralization studies indicated that these sediments contained active acetotrophic methanogens. VC degradation involved an initial transformation to acetate via oxidative acetogenesis followed by acetotrophic methanogenesis to yield CO2 and CH4 as final products. Based on these recent results, a conceptual model for anaerobic microbial degradation of VC to non-chlorinated products can be proposed.

  11. Fate of thiodicarb and its metabolite methomyl in sandy loam soil under laboratory conditions.

    PubMed

    Bisht, Sushma; Chauhan, Reena; Kumari, Beena; Singh, Rajvir

    2015-07-01

    Fate of thiodicarb and its major metabolite in sandy loam soil were studied by applying thiodicarb (Larvin 75 WP) at 500 and 1000 g a. i. ha(-1) under laboratory conditions. Samples drawn periodically were analysed on GC-FTD equipped with capillary column. The average initial deposits of total thiodicarb (thiodicarb and methomyl) were 0.025 and 0.035 mg kg(-1) at single and double dosages, respectively. Residues of thiodicarb reached below the determination level (BDL) of 0.005 mg kg(-1) after 15 days. Half-life periods for total thiodicarb were calculated to be 5.90 and 8.29 days at two doses, respectively, following first-order kinetics.

  12. Mass wasting triggered by seasonal CO2 sublimation under Martian atmospheric conditions: Laboratory experiments

    NASA Astrophysics Data System (ADS)

    Sylvest, Matthew E.; Conway, Susan J.; Patel, Manish R.; Dixon, John C.; Barnes, Adam

    2016-12-01

    Sublimation is a recognized process by which planetary landscapes can be modified. However, interpretation of whether sublimation is involved in downslope movements on Mars and other bodies is restricted by a lack of empirical data to constrain this mechanism of sediment transport and its influence on landform morphology. Here we present the first set of laboratory experiments under Martian atmospheric conditions which demonstrate that the sublimation of CO2 ice from within the sediment body can trigger failure of unconsolidated, regolith slopes and can measurably alter the landscape. Previous theoretical studies required CO2 slab ice for movements, but we find that only frost is required. Hence, sediment transport by CO2 sublimation could be more widely applicable (in space and time) on Mars than previously thought. This supports recent work suggesting CO2 sublimation could be responsible for recent modification in Martian gullies.

  13. Interpreting EChO's future data: biological laboratory extimates under M star's planetary surface conditions

    NASA Astrophysics Data System (ADS)

    Erculiani, Marco S.; Claudi, Riccardo U.; Giro, Enrico; Galletta, Giuseppe; D'Alessandro, Maurizio; Farisato, Giancarlo; Lessio, Luigi; Micela, Giuseppina; Billi, Daniela

    2014-08-01

    The EChO Exoplanet Atmosphere Characterization mission will have in the midst of its main targets, planets that orbit M stars in their or very close to their habitable zone. In this framework at the Astronomical Observatory of Padova (INAF) we are going to perform experiments that will give us an idea about the possible modification of the atmosphere by photosynthetic biota present on the planet surface. In the framework of the project "Atmosphere In a Test Tube", planetary environmental conditions are being performed. The bacteria that are being studied are Acaryochloris marina, Chroococcidiopsis sp., Cyanidium Caldarium and Halomicronema hongdechloris and tests are being performed with LISA ambient simulator in the laboratory of the Padova Astronomical Observatory.

  14. Laboratory experiment on poroelastic behavior of Berea sandstone under two-phase fluid flow condition

    NASA Astrophysics Data System (ADS)

    Goto, H.; Aichi, M.; Tokunaga, T.; Yamamoto, H.; Ogawa, T.; Aoki, T.

    2013-12-01

    Coupled two-phase fluid flow and deformation of Berea sandstone was discussed through laboratory experiments and numerical simulation. In the experiment, a triaxial compression apparatus with flow pipes to pass fluids through a rock sample was used. The experimental procedures were as follows. Firstly, external stresses close to hydrostatic condition were applied to a water saturated cylindrical Berea sandstone sample. Then, compressed air was infiltrated from the bottom of the sample. During the experiment, both axial and circumferential strains at half the height of the sample and volumetric discharge of water at the outlet were measured. Both strains showed sudden extensions after a few seconds, and monotonically extended thereafter. The volumetric discharge of water showed that air breakthrough occurred in around 100 seconds after the commencement of the air injection. Numerical simulations based on thermodynamically consistent constitutive equations were conducted in order to quantitatively analyze the experimental results. In a simulation in which the material was assumed to be homogeneous isotropic, the axial strain at half the height of the sample and the volumetric discharge of water at the outlet were reproduced well by using reasonable parameters, while that was not the case with the circumferential strain at half the height of the sample. On the other hand, in a simulation in which anisotropy of the material was introduced, all experimental data were reproduced well by using reasonable parameters. This result is reasonable because Berea sandstone is well known to be anisotropic under such Terzaghi effective stress condition as used in our experiment, i.e., 3.0 MPa (Hart and Wang, 1999; Hart, 2000). Our results indicate that the theory of poroelasticity for two-phase fluid system can explain the strain behavior of porous media for two-phase fluid flow observed in laboratory experiments.

  15. Vital statistics of Triatominae (Hemiptera: Reduviidae) under laboratory conditions: III. Rhodnius neglectus.

    PubMed

    Rabinovich, Jorge Eduardo; Nieves, Eliana Lorena

    2011-07-01

    Five cohorts of 100 eggs of Rhodnius neglectus Lent 1954 (Hemiptera Reduviidae) were reared simultaneously in the laboratory under constant conditions (26 +/- 1 degrees C and 60 +/- 10% RH), with mortality and fecundity data recorded weekly. We calculated stage-specific developmental times, age-specific mortality and fecundity, stage-specific and total preadult mortality, and the intrinsic rate of natural increase (r0 = 0.21), the finite population growth rate (h = 1.23), the net reproductive rate (R0 = 314.24), and the generation time (T = 21.45 wk). Elasticity analysis showed that the dominant life-history traits determining lamda were the adult female survival, and the survival of instar V nymphs (molting into adult females). Adult females dominated the stage-specific reproductive value, and the egg stage dominated the stable stage distribution (SSD). The damping ratio (p = 1.11) suggests a relatively rapid period of recovery to a disturbed SSD. Results were compared with previous values from the literature and conform relatively well, considering that environmental conditions were not always the same. Compared with two other species of the same genus, Rhodnius neivai Lent 1953 and Rhodnius prolixus Stål 1859, R. neglectus ranked higher in fecundity (total eggs/ female /life) and in female longevity, intermediate in the intrinsic rate of natural increase (r0), and lower in developmental time and mortality. By fitting a logistic model of population growth to the density field values of a spontaneous colonization of two field experimental chicken coops we estimated the intrinsic rate of natural increase and carrying capacity parameters, and compared the former with our laboratory results.

  16. Laboratory facility to create reference radon + thoron atmosphere under dynamic exposure conditions.

    PubMed

    Pressyanov, D; Mitev, K; Georgiev, S; Dimitrova, I; Kolev, J

    2017-01-01

    Radon ((222)Rn) and thoron ((220)Rn) levels in the environment are typically subject to significant random and systematic variations. Creation in the laboratory of reproducible and controlled exposure conditions close to that in the real environment can be useful for testing (222)Rn and (220)Rn detectors and for research. In this report the design and performance of a novel laboratory facility with such functionality is presented. The facility allows the exposure of detectors under controlled dynamic as well as static activity concentrations of (222)Rn and (220)Rn (pure and mixed) and temperature. The temperature is measured and regulated within -15 °C ÷ +60 °C by a dedicated programmable thermostat. Different reference activity concentrations in the exposure vessel are made by regulating the flow-rate of the air that flushes (222)Rn/(220)Rn activity from the sources towards the exposure vessel. Reference atmospheres that contain (222)Rn, (220)Rn or a specified ratio of the two can be created. Pilot experiments that demonstrate the feasibility of the approach are presented. They include follow-up of a pre-defined temperature profile (in the range -5 °C ÷ +35 °C), test of the correspondence between planned and measured (222)Rn and (220)Rn activity concentrations, follow-up of a pre-defined dynamic profile of (220)Rn concentrations and test of the possibility to create mixed (220)Rn/(222)Rn atmospheres (experimentally checked for ratio of the activity concentrations from 0.27 to 4.5). The results from the experimental tests are in agreement with the values obtained by the developed theoretical model. The proposed approach can be used to plan and create stationary and dynamic reference exposure conditions that are close to the real exposure regimes in the environment.

  17. IMAGE Project: Results of Laboratory Tests on Tracers for Supercritical Conditions.

    NASA Astrophysics Data System (ADS)

    Brandvoll, Øyvind; Opsahl Viig, Sissel; Nardini, Isabella; Muller, Jiri

    2016-04-01

    The use of tracers is a well-established technique for monitoring dynamic behaviour of water and gas through a reservoir. In geothermal reservoirs special challenges are encountered due to high temperatures and pressures. In this work, tracer candidates for monitoring water at supercritical conditions (temperature > 374°C, pressure ca 218 bar), are tested in laboratory experiments. Testing of tracers at supercritical water conditions requires experimental set-ups which tolerate harsh conditions with respect to high temperature and pressure. In addition stringent HES (health, environment and safety) factors have to be taken into consideration when designing and performing the experiments. The setup constructed in this project consists of a pressure vessel, high pressure pump, instrumentation for pressure and temperature control and instrumentation required for accurate sampling of tracers. In order to achieve accurate results, a special focus has been paid to the development of the tracer sampling technique. Perfluorinated cyclic hydrocarbons (PFCs) have been selected as tracer candidates. This group of compounds is today commonly used as gas tracers in oil reservoirs. According to the literature they are stable at temperatures up to 400°C. To start with, five PFCs have been tested for thermal stability in static experiments at 375°C and 108 bar in the experimental setup described above. The tracer candidates will be further tested for several months at the relevant conditions. Preliminary results indicate that some of the PFC compounds show stability after three months. However, in order to arrive at conclusive results, the experiments have to be repeated over a longer period and paying special attention to more accurate sampling procedures.

  18. Survival potential and photosynthetic activity of lichens under Mars-like conditions: a laboratory study.

    PubMed

    de Vera, Jean-Pierre; Möhlmann, Diedrich; Butina, Frederike; Lorek, Andreas; Wernecke, Roland; Ott, Sieglinde

    2010-03-01

    Lichens were repetitively exposed over 22 days to thermophysical Mars-like conditions at low-and mid-latitudes. The simulated parameters and the experimental setup are described. Natural samples of the lichen Xanthoria elegans were used to investigate their ability to survive the applied Mars-like conditions. The effects of atmospheric pressure, CO(2) concentration, low temperature, water availability, and light on Mars were also studied. The results of these experiments indicate that no significant decrease in the vitality of the lichen occurred after exposure to simulated martian conditions, which was demonstrated by confocal laser scanning microscopy analysis, and a 95% CO(2) atmosphere with 100% humidity, low pressure (partial pressure of CO(2) was 600 Pa), and low temperature has a balancing effect on photosynthetic activity as a function of temperature. This means a starting low photosynthetic activity at high CO(2) concentrations with Earth-like pressure has a reduction of 60%. But, if the simulated atmospheric pressure is reduced to Mars-like conditions with the maintenance of the same Mars-like 95% CO(2) concentration, the photosynthetic activity increases and again reaches similar values as those exhibited under terrestrial atmospheric pressure and concentration. Based on these results, we presume that, in any region on Mars where liquid water might be available, even for short periods of time, a eukaryotic symbiotic organism would have the ability to survive, at least over weeks, and to temporarily photosynthesize.

  19. Damage of natural stone tablets exposed to exhaust gas under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Farkas, Orsolya; Szabados, György; Török, Ákos

    2016-04-01

    Natural stone tablets were exposed to exhaust gas under laboratory conditions to assess urban stone damage. Cylindrical test specimens (3 cm in diameter) were made from travertine, non-porous limestone, porous limestone, rhyolite tuff, sandstone, andesite, granite and marble. The samples were exposed to exhaust gas that was generated from diesel engine combustion (engine type: RÁBA D10 UTSLL 160, EURO II). The operating condition of the internal combustion engine was: 1300 r/m (app 50%). The exhaust gas was diverted into a pipe system where the samples were placed perpendicular to main flow for 1, 2, 4, 8 and 10 hours, respectively. The exhaust emission was measured by using AVL particulate measurement technology; filter paper method (AVL 415). The stone samples were documented and selective parameters were measured prior to and after exhaust gas exposure. Density, volume, ultrasonic pulse velocity, mineral composition and penetration depth of emission related particulate matter were recorded. The first results indicate that after 10 hours of exposure significant amount of particulate matter deposited on the stone surface independently from the surface properties and porosity. The black soot particles uniformly covered all types of stones, making hard to differentiate the specimens.

  20. Practical Application of Electrochemical Nitrate Sensor under Laboratory and Forest Nursery Conditions

    PubMed Central

    Caron, William-Olivier; Lamhamedi, Mohammed S.; Viens, Jeff; Messaddeq, Younès

    2016-01-01

    The reduction of nitrate leaching to ensure greater protection of groundwater quality has become a global issue. The development of new technologies for more accurate dosing of nitrates helps optimize fertilization programs. This paper presents the practical application of a newly developed electrochemical sensor designed for in situ quantification of nitrate. To our knowledge, this paper is the first to report the use of electrochemical impedance to determine nitrate concentrations in growing media under forest nursery conditions. Using impedance measurements, the sensor has been tested in laboratory and compared to colorimetric measurements of the nitrate. The developed sensor has been used in water-saturated growing medium and showed good correlation to certified methods, even in samples obtained over a multi-ion fertilisation season. A linear and significant relationship was observed between the resistance and the concentration of nitrates (R2 = 0.972), for a range of concentrations of nitrates. We also observed stability of the sensor after exposure of one month to the real environmental conditions of the forest nursery. PMID:27483266

  1. Assessment of aliphatic-aromatic copolyester biodegradable mulch films. Part II: laboratory simulated conditions.

    PubMed

    Kijchavengkul, Thitisilp; Auras, Rafael; Rubino, Maria; Ngouajio, Mathieu; Fernandez, R Thomas

    2008-04-01

    In a previous paper, we demonstrated that the main mechanism of degradation of poly(butylene adipate-co-terephthalate) (PBAT) biodegradable mulch films when exposed to field conditions was crosslinking due to the photodegradation from solar radiation. The aim of this work was to determine the effect of crosslinking on the biodegradability of PBAT samples. PBAT films were subjected to UV photodegradation in laboratory simulated conditions to investigate the effects of crosslinking and other major changes in the structure and mechanical properties of the films. Crosslinking caused the films to become more brittle and produced a reduction of the tensile strength and percent elongation. Besides the crosslinking degradation mechanism, chain scission also occurred in the samples. After 45d of biodegradation test, the non-crosslinked PBAT sample reached 60% of mineralization. However, the percent mineralization was reduced when samples were crosslinked. The percent mineralization of samples with 10%, 30%, 50%, and 70% gel content was 36%, 43%, 21%, and 24%, respectively. Our results indicate that crosslinking is a key process underlying the degradation of the PBAT film and did affect the biodegradability of the films, since the samples with greater amount of gel content generally showed less percent mineralization in the biodegradation tests.

  2. Laboratory experiments on solute transport in bimodal porous media under cyclic precipitation-evaporation boundary conditions

    NASA Astrophysics Data System (ADS)

    Cremer, Clemens; Neuweiler, Insa

    2016-04-01

    Flow and solute transport in the shallow subsurface is strongly governed by atmospheric boundary conditions. Erratically varying infiltration and evaporation cycles lead to alternating upward and downward flow, as well as spatially and temporally varying water contents and associated hydraulic conductivity of the prevailing materials. Thus presenting a highly complicated, dynamic system. Knowledge of subsurface solute transport processes is vital to assess e.g. the entry of, potentially hazardous, solutes to the groundwater and nutrient uptake by plant roots and can be gained in many ways. Besides field measurements and numerical simulations, physical laboratory experiments represent a way to establish process understanding and furthermore validate numerical schemes. With the aim to gain a better understanding and to quantify solute transport in the unsaturated shallow subsurface under natural precipitation conditions in heterogeneous media, we conduct physical laboratory experiments in a 22 cm x 8 cm x 1 cm flow cell that is filled with two types of sand and apply cyclic infiltration-evaporation phases at the soil surface. Pressure at the bottom of the domain is kept constant. Following recent studies (Lehmann and Or, 2009; Bechtold et al., 2011a), heterogeneity is introduced by a sharp vertical interface between coarse and fine sand. Fluorescent tracers are used to i) qualitatively visualize transport paths within the domain and ii) quantify solute leaching at the bottom of the domain. Temporal and spatial variations in water content during the experiment are derived from x-ray radiographic images. Monitored water contents between infiltration and evaporation considerably changed in the coarse sand while the fine sand remained saturated throughout the experiments. Lateral solute transport through the interface in both directions at different depths of the investigated soil columns were observed. This depended on the flow rate applied at the soil surface and

  3. Laboratory investigation of spray generation mechanism in wind-wave interaction under strong wind conditions

    NASA Astrophysics Data System (ADS)

    Kandaurov, Alexander; Troitskaya, Yuliya; Sergeev, Daniil; Ermakova, Olga; Kazakov, Vassily

    2015-04-01

    The sea spray is considered as a possible mechanism of the reduction of sea surface aerodynamic drag coefficient at hurricane conditions [1]. In this paper the mechanism of generation of spray in the near-surface layer of the atmosphere in a strong wind through the mechanism of «bag-breakup instability» was investigated in laboratory conditions with the help of high-speed video shooting. The laboratory experiments were performed on the Thermostratified Wind-Wave Channel of the IAP RAS (length 10 m, cross section of air channel 0.4 x 0.4 m, wind velocity up to 24 m/s) [2]. Experiments were carried out for the wind speeds from 14 to 22 m/s. In this range spray generation characteristics change dramatically from almost no spray generation to so called catastrophic regime with multiple cascade breakups on each crest. Shooting was performed with High-speed digital camera NAC Memrecam HX-3 in two different setups to obtain both statistical data and detailed spray generation mechanism overview. In first setup bright LED spotlight with mate screen the side of a channel was used for horizontal shadow-method shooting. Camera was placed in semi-submerged box on the opposite side of the channel. Shooting was performed at the distance of 7.5 m from the beginning of the working section. Series of short records of the surface evolution were made at 10 000 fps with 55 to 119 µm/px scale revealed the dominant mechanism of spray generation - bag-breakup instability. Sequences of high resolution images allowed investigating the details of this "bags" evolution. Shadow method provided better image quality for such conditions than side illumination and fluorescence methods. To obtain statistical data on "bags" sizes and densities vertical shadow method was used. Submerged light box was created with two 300 W underwater lamps and mate screen places at the fetch of 6.5 m. Long records (up to 8 seconds) were made with 4500 fps at 124-256 µm/px scales. Specially developed software

  4. The formation of sulfate and elemental sulfur aerosols under varying laboratory conditions: implications for early earth.

    PubMed

    DeWitt, H Langley; Hasenkopf, Christa A; Trainer, Melissa G; Farmer, Delphine K; Jimenez, Jose L; McKay, Christopher P; Toon, Owen B; Tolbert, Margaret A

    2010-10-01

    The presence of sulfur mass-independent fractionation (S-MIF) in sediments more than 2.45 × 10(9) years old is thought to be evidence for an early anoxic atmosphere. Photolysis of sulfur dioxide (SO(2)) by UV light with λ < 220 nm has been shown in models and some initial laboratory studies to create a S-MIF; however, sulfur must leave the atmosphere in at least two chemically different forms to preserve any S-MIF signature. Two commonly cited examples of chemically different sulfur species that could have exited the atmosphere are elemental sulfur (S(8)) and sulfuric acid (H(2)SO(4)) aerosols. Here, we use real-time aerosol mass spectrometry to directly detect the sulfur-containing aerosols formed when SO(2) either photolyzes at wavelengths from 115 to 400 nm, to simulate the UV solar spectrum, or interacts with high-energy electrons, to simulate lightning. We found that sulfur-containing aerosols form under all laboratory conditions. Further, the addition of a reducing gas, in our experiments hydrogen (H(2)) or methane (CH(4)), increased the formation of S(8). With UV photolysis, formation of S(8) aerosols is highly dependent on the initial SO(2) pressure; and S(8) is only formed at a 2% SO(2) mixing ratio and greater in the absence of a reductant, and at a 0.2% SO(2) mixing ratio and greater in the presence of 1000 ppmv CH(4). We also found that organosulfur compounds are formed from the photolysis of CH(4) and moderate amounts of SO(2). The implications for sulfur aerosols on early Earth are discussed. Key Words: S-MIF-Archean atmosphere-Early Earth-Sulfur aerosols.

  5. Temperature management during semen processing: Impact on boar sperm quality under laboratory and field conditions.

    PubMed

    Schulze, M; Henning, H; Rüdiger, K; Wallner, U; Waberski, D

    2013-12-01

    Freshly collected boar spermatozoa are sensitive to a fast reduction in temperature because of lipid phase transition and phase separation processes. Temperature management during semen processing may determine the quality of stored samples. The aim of this study was to evaluate the influence of isothermic and hypothermic semen processing protocols on boar sperm quality under laboratory and field conditions. In the laboratory study, ejaculates (n = 12) were first diluted (1:1) with Beltsville Thawing Solution (BTS) at 32 °C, then processed either with isothermic (32 °C) or hypothermic (21 °C) BTS, stored at 17 °C, and assessed on days 1, 3, and 6. Temperature curves showed that 150 minutes after the first dilution, semen doses of both groups reached the same temperature. Two-step hypothermic processing resulted in lower sperm motility on days 1 and 6 (P < 0.05). Concomitantly, hypothermally processed samples contained less membrane intact sperm on days 3 and 6 (P < 0.05). Using AndroStar Plus extender instead of BTS reduced the negative effect of hypothermic processing. In the field study, 15 semen samples from each of 23 European artificial insemination studs were evaluated as part of an external quality control program. Semen quality based on motility, membrane integrity, mitochondrial activity, and a thermoresistance test was higher for stations using one-step isothermic dilutions (n = 7) compared with artificial insemination centers using two-step hypothermic protocols (n = 16). Both studies show that chilling injury associated with hypothermic dilution results in lower quality of stored boar semen compared with isothermic dilution and that the type of semen extender affects the outcomes.

  6. A design of optical measurement laboratory for space-based illumination condition emulation

    NASA Astrophysics Data System (ADS)

    Xu, Rong; Zhao, Fei; Yang, Xin

    2015-10-01

    Space Objects Identification(SOI) and related technology have aroused wide attention from spacefaring nations due to the increasingly severe space environment. Multiple ground-based assets have been employed to acquire statistical survey data, detect faint debris, acquire photometric and spectroscopic data. Great efforts have been made to characterize different space objects using the statistical data acquired by telescopes. Furthermore, detailed laboratory data are needed to optimize the characterization of orbital debris and satellites via material composition and potential rotation axes, which calls for a high-precision and flexible optical measurement system. A typical method of taking optical measurements of a space object(or model) is to move light source and sensors through every possible orientation around it and keep the target still. However, moving equipments to accurate orientations in the air is difficult, especially for those large precise instruments sensitive to vibrations. Here, a rotation structure of "3+1" axes, with a three-axis turntable manipulating attitudes of the target and the sensor revolving around a single axis, is utilized to emulate every possible illumination condition in space, which can also avoid the inconvenience of moving large aparatus. Firstly, the source-target-sensor orientation of a real satellite was analyzed with vectors and coordinate systems built to illustrate their spatial relationship. By bending the Reference Coordinate Frame to the Phase Angle plane, the sensor only need to revolve around a single axis while the other three degrees of freedom(DOF) are associated with the Euler's angles of the satellite. Then according to practical engineering requirements, an integrated rotation system of four-axis structure is brought forward. Schemetic diagrams of the three-axis turntable and other equipments show an overview of the future laboratory layout. Finally, proposals on evironment arrangements, light source precautions

  7. The Formation of Sulfate and Elemental Sulfur Aerosols Under Varying Laboratory Conditions: Implications for Early Earth

    NASA Technical Reports Server (NTRS)

    DeWitt, H. Langley; Hasenkopf, Christa A.; Trainer, Melissa G.; Farmer, Delphine K.; Jimenez, Jose L.; McKay, Christopher P.; Toon, Owen B.; Tolbert, Margaret A.

    2010-01-01

    The presence of sulfur mass-independent fractionation (S-MIF) in sediments more than 2.45 x 10(exp 9) years old is thought to be evidence for an early anoxic atmosphere. Photolysis of sulfur dioxide (SO2) by UV light with lambda < 220 nm has been shown in models and some initial laboratory studies to create a S-MIF; however, sulfur must leave the atmosphere in at least two chemically different forms to preserve any S-MIF signature. Two commonly cited examples of chemically different sulfur species that could have exited the atmosphere are elemental sulfur (S8) and sulfuric acid (H2S04) aerosols. Here, we use real-time aerosol mass spectrometry to directly detect the sulfur-containing aerosols formed when SO2 either photolyzes at wavelengths from 115 to 400 nm, to simulate the UV solar spectrum, or interacts with high-energy electrons, to simulate lightning. We found that sulfur-containing aerosols form under all laboratory conditions. Further, the addition of a reducing gas, in our experiments hydrogen (H2) or methane (CH4), increased the formation of S8. With UV photolysis, formation of S8 aerosols is highly dependent on the initial SO2 pressure; and S8 is only formed at a 2% SO2 mixing ratio and greater in the absence of a reductant, and at a 0.2% SO2 mixing ratio and greater in the presence of 1000 ppmv CH4. We also found that organosulfur compounds are formed from the photolysis of CH4 and moderate amounts of SO2, The implications for sulfur aerosols on early Earth are discussed.

  8. Performance of transient limiters under laboratory, simulated, and rocket-triggered lightning conditions

    SciTech Connect

    Hasbrouck, R.T.; Johnson, J.P.; Breitmeier, J.

    1989-07-02

    We have designed and tested a prototype system that implements a lightning-protection method referred to as the ''fortress concept.'' The fortress, a structure similar to a Faraday cage, protects the critical system by surrounding it with a continuous metallic skin. Each electrical conductor that must enter the fortress is enclosed within a cable, which is, in turn, enclosed in a metallic shield that terminates at the entry point and is electrically bonded to the fortress' outer metallic surface. Within the fortress, each penetrating conductor is protected by a transient limiter. The system was tested by means of full-threat-level simulated lightning and actual lightening triggered by rockets. Several limited components were subsequently tested by using a laboratory-type surge generator to investigate certain anomalous responses. This paper reviews the fortress concept, discusses the operation of the limiters, and examines their performance. Explanations are offered for the anomalous responses, and several important design considerations and trade-offs are offered. 3 refs., 15 figs.

  9. Stress, deformation and micromorphological aspects of soil freezing under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Jetchick, Elizabeth

    In this thesis, frost heave is viewed as a process resulting from the interactions between thermodynamic conditions, soil environment controls such as texture, stress/deformation conditions and soil microstructure. A series of laboratory experiments was devised to investigate the links between these aspects. Because a limited number of studies exist on the development of internal stresses and strains in freezing soil, the work focussed on obtaining rheological data using conventional soil strain gauges and prototype stress transducers. A fine-grained unstructured silt was placed in a column (30 cm diameter by 100 cm length) and subjected to freezing and freeze-thaw cycles from the top down, lasting up to three months. Heat and water flows, as well as stresses and strains were monitored. The frozen soil was sectioned at the end of four of the experiments to examine the soil fabrics that had developed. From the experimental results, schematic stress and strain curves are proposed. For a single freeze cycle, compressive normal and tensile normal stresses were recorded simultaneously by the measuring devices within the freezing soil profile. Ice lens inception took place when the stress field changed, a condition which occurred either at the frost front level or at the base of the growing ice lens. Negative and positive strains reflected the different stress states that were sustained below and above the freezing front. Negative strains or soil consolidation took place as stresses increased before the passage of the frost line. Negligible soil strains were recorded as maximum soil consolidation was attained, before soil expansion. Distinct positive strain patterns indicating secondary and continuing heave, were recorded simultaneously throughout a thickness of soil, over a range of temperatures. Ice lens growth mostly took place as secondary frost heave, but continuing heave was measured, and the temperature conditions for both types of heave were determined. During

  10. Effects of 2 fungicide formulations on microbial and macroinvertebrate leaf decomposition under laboratory conditions

    USGS Publications Warehouse

    Elskus, Adria; Smalling, Kelly L.; Hladik, Michelle; Kuivila, Kathryn

    2016-01-01

    Aquatic fungi contribute significantly to the decomposition of leaves in streams, a key ecosystem service. However, little is known about the effects of fungicides on aquatic fungi and macroinvertebrates involved with leaf decomposition. Red maple (Acer rubrum) leaves were conditioned in a stream to acquire microbes (bacteria and fungi), or leached in tap water (unconditioned) to simulate potential reduction of microbial biomass by fungicides. Conditioned leaves were exposed to fungicide formulations QUILT (azoxystrobin + propiconazole) or PRISTINE (boscalid + pyraclostrobin), in the presence and absence of the leaf shredder, Hyalella azteca (amphipods; 7-d old at start of exposures) for 14 d at 23 °C. QUILT formulation (~ 0.3 μg/L, 1.8 μg/L, 8 μg/L) tended to increase leaf decomposition by amphipods (not significant) without a concomitant increase in amphipod biomass, indicating potential increased consumption of leaves with reduced nutritional value. PRISTINE formulation (~ 33 μg/L) significantly reduced amphipod growth and biomass (p<0.05), effects similar to those observed with unconditioned controls. The significant suppressive effects of PRISTINE on amphipod growth, and the trend towards increased leaf decomposition with increasing QUILT concentration, indicate the potential for altered leaf decay in streams exposed to fungicides. Further work is needed to evaluate fungicide effects on leaf decomposition under conditions relevant to stream ecosystems, including temperature shifts and pulsed exposures to pesticide mixtures.

  11. Measuring ignitability for in situ burning of oil spills weathered under Arctic conditions: from laboratory studies to large-scale field experiments.

    PubMed

    Fritt-Rasmussen, Janne; Brandvik, Per Johan

    2011-08-01

    This paper compares the ignitability of Troll B crude oil weathered under simulated Arctic conditions (0%, 50% and 90% ice cover). The experiments were performed in different scales at SINTEF's laboratories in Trondheim, field research station on Svalbard and in broken ice (70-90% ice cover) in the Barents Sea. Samples from the weathering experiments were tested for ignitability using the same laboratory burning cell. The measured ignitability from the experiments in these different scales showed a good agreement for samples with similar weathering. The ice conditions clearly affected the weathering process, and 70% ice or more reduces the weathering and allows a longer time window for in situ burning. The results from the Barents Sea revealed that weathering and ignitability can vary within an oil slick. This field use of the burning cell demonstrated that it can be used as an operational tool to monitor the ignitability of oil spills.

  12. The similarities and diversities of signal pathways leading to consolidation of conditioning and consolidation of extinction of fear memory.

    PubMed

    Lin, Chih-Hung; Yeh, Shiu-Hwa; Lu, Hsin-Yi; Gean, Po-Wu

    2003-09-10

    It is generally believed that consolidation of long-term memory requires activation of protein kinases, transcription of genes, and new protein synthesis. However, little is known about the signal cascades involved in the extinction of memory, which occurs when the conditioned stimulus is no longer followed by the unconditioned stimulus. Here, we show for the first time that an intra-amygdala injection of transcription inhibitor actinomycin D at the dose that blocked acquisition failed to affect extinction of a learned response. Conversely, protein synthesis inhibitor anisomycin blocked both acquisition and extinction. Extinction training-induced expression of calcineurin was blocked by anisomycin but not by actinomycin D. NMDA receptor antagonist, phosphatidylinositol 3-kinase (PI-3 kinase), and MAP kinase inhibitors that blocked the acquisition also blocked the extinction of conditioned fear. Likewise, PI-3 kinase inhibitor blocked fear training-induced cAMP response element-binding protein (CREB) phosphorylation as well as extinction training-induced decrease in CREB phosphorylation, the latter of which was associated with calcineurin expression and could be reversed by a specific calcineurin inhibitor. Thus, molecular processes that underlie long-term behavioral changes after acquisition and extinction share some common mechanisms and also display different characteristics.

  13. Assessing the role of spanwise roughness heterogeneity and establishing conditions for application of Townsend's hypothesis of outer-layer similarity

    NASA Astrophysics Data System (ADS)

    Yang, Jianzhi; Anderson, William

    2016-11-01

    In the present work, turbulent secondary flows in turbulent channel flows are forced by virtue of passive-actuator-like topographic features. The topographies are constructed with streamwise-repeating pyramidal topographic elements which create "rows" with infinite streamwise extent; then, the spacing between such rows is systematically varied. The spanwise spacing is varied from 0.2 to 6.4. For spanwise spacing exceeding double the channel half-height, free domain-scale secondary flows are observed. The domain-scale secondary flows exist in the Reynolds-averaged statistics, and remain permanently positioned such that downwelling and upwelling occurs above the elements and flat region, respectively (i.e., we have introduced low- and high-momentum pathways; Ken Christensen et al.). At the element scale, counter-rotating vortices flank the roughness elements, with rotational sign opposite to the larger-scale circulations. When spanwise spacing is less than double the channel half-height, the domain-scale secondary flows attenuate, while the element-scale secondary flows remain for all spacings. Since the domain-scale circulations alter the outer-layer turbulence statistics, we are working to assess spacing as a control on the efficacy of Townsend's hypothesis of outer-layer similarity in turbulent channel flow. Air Force Office of Scientific Research, Grant # FA9550-14-1-0394.

  14. Laboratory Investigations of a Low-Swirl Injector with H2 and CH4 at Gas Turbine Conditions

    SciTech Connect

    Cheng, R. K.; Littlejohn, D.; Strakey, P.A.; Sidwell, T.

    2008-03-05

    Laboratory experiments were conducted at gas turbine and atmospheric conditions (0.101 < P{sub 0} < 0.810 MPa, 298 < T{sub 0} < 580K, 18 < U{sub 0} < 60 m/s) to characterize the overall behaviors and emissions of the turbulent premixed flames produced by a low-swirl injector (LSI) for gas turbines. The objective was to investigate the effects of hydrogen on the combustion processes for the adaptation to gas turbines in an IGCC power plant. The experiments at high pressures and temperatures showed that the LSI can operate with 100% H{sub 2} at up to {phi} = 0.5 and has a slightly higher flashback tolerance than an idealized high-swirl design. With increasing H{sub 2} fuel concentration, the lifted LSI flame begins to shift closer to the exit and eventually attaches to the nozzle rim and assumes a different shape at 100% H{sub 2}. The STP experiments show the same phenomena. The analysis of velocity data from PIV shows that the stabilization mechanism of the LSI remains unchanged up to 60% H{sub 2}. The change in the flame position with increasing H{sub 2} concentration is attributed to the increase in the turbulent flame speed. The NO{sub x} emissions show a log linear dependency on the adiabatic flame temperature and the concentrations are similar to those obtained previously in a LSI prototype developed for natural gas. These results show that the LSI exhibits the same overall behaviors at STP and at gas turbine conditions. Such insight will be useful for scaling the LSI to operate at IGCC conditions.

  15. Laboratory measurements of basalts electrical resistivity under deep oceanic crustal conditions

    NASA Astrophysics Data System (ADS)

    Violay, M. E.; Gibert, B.; Azais, P.; Pezard, P. A.; Flovenz, O. G.; Asmundsson, R.

    2009-12-01

    For sixty years, electrical resistivity soundings have been used to explore geothermal resources in Iceland. They have generally revealed two zones of high electrical conductivity, one at shallow depths (Flovenz et al., 1985) and another at 10-30 km depth (Beblo and Björnsson, 1978). The interpretation of these conductive zones in terms of composition and in-situ physical conditions is often ambiguous, as various parameters can explain these observations like temperature, partial melting, change in minerals and type of pore fluid. Accurate interpretations of resistivity data needed for geothermal exploration require laboratory measurements of electrical conductivities performed on rock samples at different conditions. We present here a method to measure electrical conductivity of rocks under deep crustal conditions for oceanic crustal rock, i.e. at temperatures up to 600°C, confining pressures up to 200 MPa and pore fluid pressures up to 50 MPa. The method has been developed in a internally heated, gas pressure apparatus (Paterson press). Electrical conductivity is measured on large cylindrical samples (15 to 22 mm in diameter and 10 to 15 mm in length) in a two parallel electrodes geometry. Such experiments require that the fluid saturated sample is sleeved in an impermeable and deformable jacket serving to separate the confining pressure medium (high pressure argon) from the pore fluid saturated sample. At temperature above 200°C a metal sleeve must be used, although it induces high leakage currents that could affect electrical measurements. The leakage currents are reduced using addition of 2 guard-ring parallel electrodes (Glover, 1995). The electrical impedance of basalt has been measured over a frequency range from 10 -1 to 106 Hertz. Five different types of low porosity basalts were selected to cover a range in alteration grade, from albitic to granulite facies. Application of this method will provide data on electrical conductivity of fresh and altered

  16. Amplified DNAs in laboratory stocks of Leishmania tarentolae: extrachromosomal circles structurally and functionally similar to the inverted-H-region amplification of methotrexate-resistant Leishmania major

    SciTech Connect

    Petrillo-Peixoto, M.L.; Beverley, S.M. )

    1988-12-01

    We describe the structure of amplified DNA that was discovered in two laboratory stocks of the protozoan parasite Leishmania tarentolae. Restriction mapping and molecular cloning revealed that a region of 42 kilobases was amplified 8- to 30-fold in these lines. Southern blot analyses of digested DNAs or chromosomes separated by pulsed-field electrophoresis showed that the amplified DNA corresponded to the H region, a locus defined originally by its amplification in methotrexate-resistant Leishmania major. Similarities between the amplified DNA of the two species included (i) extensive cross-hybridization; (ii) approximate conservation of sequence order; (iii) extrachromosomal localization; (iv) an overall inverted, head-to-head configuration as a circular 140-kilobase tetrameric molecule; (v) two regions of DNA sequence rearrangement, each of which was closely associated with the two centers of the inverted repeats; (vi) association with methotrexate resistance; and (vii) phenotypically conservative amplification, in which the wild-type chromosomal arrangement was retained without apparent modification. Our data showed that amplified DNA mediating drug resistance arose in unselected L. tarentolae, although the pressures leading to apparently spontaneous amplification and maintenance of the H region are not known. The simple structure and limited extent of DNA amplified in these and other Leishmania lines suggests that the study of gene amplification in Leishmania spp. offers an attractive model system for the study of amplification in cultured mammalian cells and tumors. We also introduced a method for measuring the size of large circular DNAs, using gamma-irradiation to introduce limited double-strand breaks followed by sizing of the linear DNAs by pulsed-field electrophoresis.

  17. Effects of PCB contamination on the reproduction of the DAB Limanda limanda L. under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Fonds, Mark; Casal, Elizabeth; Schweizer, Dominik; Boon, Jan P.; Van der Veer, Henk W.

    The effect of PCB contamination on the reproduction of female dab was studied under laboratory conditions. Females were contaminated during gonad maturation by multiple oral administration of capsules containing the technical PCB mixture Clophen A40. PCB contamination resulted in increased levels in the eggs, with concentrations of selected PCB congeners of 35 to 86 μg·g -1 lipid for PCB-exposed fish, 10 μg·g -1 lipid for eggs from fish fed with mussel meat and fish fed with shrimp. A statistically significant dose-effect relationship was found between the PCB content of the eggs and the PCB dose ingested by the fish. For eggs from the PCB-treated fish the mean fertilization rate was 61% and mean hatching 45%, compared to 67% fertilization and 59% hatching for eggs from untreated fish. Rate of development and survival of the eggs and mortality of the larvae after hatching were mainly related to incubation temperature. No statistically significant differences between untreated and PCB-treated fish could be found in egg production, egg quality, fertilization rate, hatching rate and survival of larvae.

  18. Turbulent dispersivity under conditions relevant to airborne disease transmission between laboratory animals

    NASA Astrophysics Data System (ADS)

    Halloran, Siobhan; Ristenpart, William

    2013-11-01

    Virologists and other researchers who test pathogens for airborne disease transmissibility often place a test animal downstream from an inoculated animal and later determine whether the test animal became infected. Despite the crucial role of the airflow in pathogen transmission between the animals, to date the infectious disease community has paid little attention to the effect of airspeed or turbulent intensity on the probability of transmission. Here we present measurements of the turbulent dispersivity under conditions relevant to experimental tests of airborne disease transmissibility between laboratory animals. We used time lapse photography to visualize the downstream transport and turbulent dispersion of smoke particulates released from a point source downstream of an axial fan, thus mimicking the release and transport of expiratory aerosols exhaled by an inoculated animal. We show that for fan-generated turbulence the plume width is invariant with the mean airspeed and, close to the point source, increases linearly with downstream position. Importantly, the turbulent dispersivity is insensitive to the presence of meshes placed downstream from the point source, indicating that the fan length scale dictates the turbulent intensity and corresponding dispersivity.

  19. Photodegradation of organic pollutants on the spruce needle wax surface under laboratory conditions.

    PubMed

    Dolinová, Jindriska; Klánová, Jana; Klán, Petr; Holoubek, Ivan

    2004-12-01

    The photochemistry of selected organic compounds, including common pollutants, on the paraffin (as a model matrix) and spruce wax surfaces was studied under laboratory conditions. Two model transformations were evaluated: (1) intramolecular rearrangements of valerophenone and 2-nitrobenzaldehyde, and (2) hydrogen abstraction between an excited benzophenone and the hydrocarbon paraffin/wax chains. The steric or polar influence of the solid matrix on conformational and translational motion, its optical properties, hydrogen abstraction probabilities, and consequences of the guest-molecule segregation are discussed in this work. Furthermore, the photochemical reactivity of some common anthropogenic pollutants, such as chlorinated biphenyls (4-chlorobiphenyl, 2,4-dichlorobiphenyl, and 4,4'-dichlorobiphenyl), 4-chlorophenol, and DDT, was evaluated. The surface of spruce wax is presented as probable reaction medium for photochemical transformations. Although the matrix presents certain restrictions for bimolecular reactions, common photodegradations should be generally feasible in nature. In addition, paraffin was found to be a suitable model matrix for the studies of possible photochemical transformations that can occur on natural plant surfaces.

  20. Life history of the sand fly vector Lutzomyia cruciata in laboratory conditions.

    PubMed

    Castillo, A; Serrano, A K; Mikery, O F; Pérez, J

    2015-12-01

    Lutzomyia cruciata Coquillet (Diptera: Psychodidae: Phlebotominae) is a potential vector of Leishmania sp.; its geographical distribution in Mexico is widespread, but its life history is unknown. The present study gives relevant information on the life cycle, morphology, survival and reproduction of Lu. cruciata observed over successive generations under laboratory conditions. Seven successive generations were produced. A total of 975 adults were obtained in a sexual proportion of 1.1 : 1 (female : male). Each Lu. cruciata female produced 20.7 eggs and 1.9 adults, approximately, with a proportion of eggs per female of 2.7% (first generation) and 21.3% (second generation). The life cycle of Lu. cruciata, from egg to adult, occurred in 52.7 ± 0.52 days. The largest percentage of mortality occurred during the egg stage (48.5%) and the first larval instar (26.5%), whereas in the pupal stage mortality was the lowest (9.1%). Lutzomyia cruciata exhibits sexual dimorphism based on size, which is exhibited as of the second larval instar, males being smaller than females. The maximum survival of females and males was 10 and 15 days, respectively. An overview of the immature stages of the species made with an electronic scanning microscope is included. This paper contributes basic information on aspects of Lu. cruciata that were previously unknown related to its life history.

  1. Turbulent dispersivity under conditions relevant to airborne disease transmission between laboratory animals

    NASA Astrophysics Data System (ADS)

    Halloran, Siobhan; Wexler, Anthony; Ristenpart, William

    2014-11-01

    Virologists and other researchers who test pathogens for airborne disease transmissibility often place a test animal downstream from an inoculated animal and later determine whether the test animal became infected. Despite the crucial role of the airflow in modulating the pathogen transmission, to date the infectious disease community has paid little attention to the effect of airspeed or turbulence intensity on the probability of transmission. Here we present measurements of the turbulent dispersivity under conditions relevant to experimental tests of airborne disease transmissibility between laboratory animals. We used time lapse photography to visualize the downstream transport and turbulent dispersion of smoke particulates released from a point source downstream of a standard axial fan, thus mimicking the release and transport of expiratory aerosols exhaled by an inoculated animal. We demonstrate that the fan speed counterintuitively has no effect on the downstream plume width, a result replicated with a variety of different fan types and configurations. The results point toward a useful simplification in modeling of airborne disease transmission via fan-generated flows.

  2. [Life tables of Blattella germanica (Dictyoptera: Blattellidae) under laboratory conditions and their importance for its control].

    PubMed

    Aguilera, L; Marquetti, M C; Gutiérrez, A; Navarro, A

    1997-01-01

    A study of the life tables of Blatella germanica (L.) 1767 was conducted under laboratory conditions. 3 treatments were used a according to the number of individuals in each breeding flask (A = 9 flasks with 20-25 individuals, B = 17 flasks with 30-35 individuals, and C = 30 flasks with a newly hatched nymph each). The main parameters of the population growth were calculated by the TABVID software . The respective values for treatments A and B were the following: net reproduction rate (Ro 2.23 and 2.37), natural increase finite rate (lambda = 1.06), natural increase intrinsic rate (r = 0.06), and mean generational time (T = 13.89 and 15.64). The behaviour of the survival probability by age, the fertility rate, and the mortality rate were graphically registered. Life expectancy for treatment C was 16.47 and the survival rate for this treatment was represented by a graph. Graphics of the growth curve of this species and of the survival rate for treatments A and B were shown. The latter was concave, which means that mortality is higher during the young stages. This study provides esential cuantitative basic date that allow to carry out a more efficient control if fight is directed to the period where the highest natural mortality was found, that is, at the step from nymph 6 to adult in treatments A and B.

  3. Comparison of several traps for catching German cockroaches (Dictyoptera: Blattellidae) under laboratory conditions.

    PubMed

    Smith, L M; Appel, A G

    2008-02-01

    German cockroach, Blattella germanica (L.) (Dictyoptera: Blattellidae), catch by five types of traps and modifications of each, were tested under controlled laboratory conditions. Cockroach catch differed significantly among traps. Lo-line trap caught the greatest number of cockroaches in the test arena for each size class (23% small nymphs, 39% of gravid females, and 60% of other size classes in the experimental arena). Jar traps caught the least number of cockroaches in the test arena for each size class (range, 7-23% of each size class trapped). Modifications of traps also altered catch of cockroaches. Food bait tablets increased catch significantly; however, increases were small (<10%). Size of traps did not affect catch; whole traps or half traps caught the same number of cockroaches. Jar traps were much less effective than sticky traps, catching only half the number of cockroaches as sticky traps. A thin layer of petrolatum was a more effective barrier in jar traps to cockroach escape than powdered Olancha clay. Traps with petrolatum caught about twice as many cockroaches as traps with clay. Trapping of any of six life stages was not significantly affected by catch of any of the other stages. Rather, trap catch of each life stage was dependent on the number of that life stage available in the experimental arenas. In conclusion, of the traps tested, the Lo-line trap was the most sensitive for measuring cockroach catch, whereas the Detector trap (one third of trap) was the most economical trap (greatest sensitivity for lowest cost).

  4. [The effect of chromium removal by algae-bacteria Bostrychia calliptera (Rhodomelaceae) consortia under laboratory conditions].

    PubMed

    Rengifo-Gallego, Ana Lucía; Peña-Salamanca, Enrique; Benitez-Campo, Neyla

    2012-09-01

    Water pollution is one of the most important environmental problems worldwide. Recently, biotechnology studies have oriented efforts to study algae-bacterium consortia with the aim to understand the mechanisms to find a possible solution in environmental sciences. This study determined the percentage of chromium removal by the alga-bacterium association exposed to a set of different chromium concentrations under controlled in vitro conditions. Wild plants of Bostrychia calliptera associated with bacterial populations were collected from Dagua River, Pacific coast of Colombia, and were monitored in the laboratory. The trial was conducted with synthetic seawater in bioreactors at two chromium levels: 5 and 10mg/L, and four different experimental treatments: i) algae-bacteria (AB), ii) algae with antibiotic (AA), iii) algal surface sediment, Natural Bacterial Consortium (CBN), and iv) the control without algae or bacteria. The experimental design followed a model of two factors (chromium concentration x combination types) with repeated measures using one factor. The microbial population behavior and the chromium concentration percentage were monitored by using atomic absorption spectroscopy (AAS). According to the data, Algae-bacteria (AB) treatment was the most efficient combination at 10mg/L (87%), whereas the bacterial consortia (CBN) was the most efficient at 5mg/L (62.85%). The results showed significant differences of chromium uptake between algae-bacteria (AB) and natural bacterial consortia (CBN), meaning the importance of those treatments in the chromium removal from coastal waters.

  5. Demographic fitness of Belminus ferroae (Hemiptera: Triatominae) on three different hosts under laboratory conditions

    PubMed Central

    Sandoval, Claudia Magaly; Medone, Paula; Nieves, Elsa Evelia; Jaimes, Diego Alexander; Ortiz, Nelcy; Rabinovich, Jorge Eduardo

    2013-01-01

    Triatominae are widely recognised for their role as vectors of Trypanosoma cruzi. One of the main biological characteristics of this subfamily is their obligate haematophagous condition. However, previous studies on Belminus herreri and Belminus ferroae suggested that cockroaches are their principal hosts in domiciles. Due to this peculiar behaviour, the aim of this study was to analyse several demographic and reproductive parameters of B. ferroae fed on three different hosts (mice, cockroaches and Rhodnius prolixus) and relate B. ferroae fitness to these alternative hosts. The cohorts were reared under constant conditions. The egg hatching rate was similar for cohorts fed on cockroaches (69.4%) and R. prolixus (63.8%), but was much lower for the cohort fed on mice (16%). The development time from the nymph to adult stage and the average age of first reproduction (α) presented lower values in the cohort fed on cockroaches, which is consistent with the higher population growth rate associated with this host. Demographic parameters [intrinsic rate of natural increase, finite rate of population growth, net reproductive rate and damping ratio] showed statistically significant differences between the cohorts. Analysis of the life history of B. ferroae revealed a higher fitness related to the cockroach. The implications of these results for the origin of the subfamily are discussed. PMID:24141961

  6. Photochemical degradation of a brominated flame retardant (tetrabromobisphenol A) in ice under field and laboratory conditions

    NASA Astrophysics Data System (ADS)

    Waligroski, G.; Grannas, A. M.

    2013-12-01

    environmentally-relevant photosensitizer, has the potential to cause indirect photochemical degradation of TBBPA and this degradation pathway was also evaluated under laboratory conditions. The potential for both commercially-derived DOM and DOM isolated from Arctic snow samples to photosensitize TBBPA degradation in liquid and ice will be evaluated and discussed.

  7. Infestation of the clam Chione fluctifraga by the burrowing worm Polydora sp. nov. in laboratory conditions.

    PubMed

    Tinoco-Orta, Gissel Dalila; Cáceres-Martínez, Jorge

    2003-07-01

    Burrowing worms that belong to Polydora spp. infest marine mollusks cultured worldwide, causing problems for production and marketing. The clam Chione fluctifraga is semi-cultured in Bahía Falsa, Baja California, NW Mexico, and some clams harbor burrowing worms. The present study was carried out to determine the identity of the worm species infesting the clam, the infesting process by cohabitation of infested and non-infested clams in aquaria with a variety of substrates (fine sand, gross sand, plastic bag used for clam culture, and aquarium without substrate) and turbulence conditions, and the occurrence of architomy phenomena in connection with infestation of the clam. The burrowing worm was considered as a nova species due to its singular limbate neurosetae and notosetae in the setiger 5, hooks in the setiger 6, eyes not present, and general pigmentation, among other characteristics. Infestation was similar in all substrates and turbulence conditions, but it was more abundant on clams previously infested than on those free of worms, showing a preferential settlement of worm infesting stages on pre-infested clams. Regeneration was observed in all segments of the worm: anterior (metastomium), medium, and posterior (prostomium); the complete regeneration time occurred in 40 days. This is the first record of architomy in a species of Polydora and this phenomenon could account for the increase of infestation intensity in pre-infested clams at the end of the study period. Infestation of clams by settling polichaete in the conditions studied, and the architomy process in this worm species, shows its great infesting capacity.

  8. Degradation of Cry1Ac protein within transgenic Bacillus thuringiensis rice tissues under field and laboratory conditions.

    PubMed

    Li, Yunhe; Wu, Kongming; Zhang, Yongjun; Yuan, Guohui

    2007-10-01

    To clarify the environmental fate of the Cry1Ac protein from Bacillus thuringiensis subsp. kurstaki (Bt) contained in transgenic rice plant stubble after harvest, degradation was monitored under field conditions using an enzyme-linked immunosorbent assay. In stalks, Cry1Ac protein concentration decreased rapidly to 50% of the initial amount during the first month after harvest; subsequently, the degradation decreased gradually reaching 21.3% when the experiment was terminated after 7 mo. A similar degradation pattern of the Cry1Ac protein was observed in rice roots. However, when the temperature increased in April of the following spring, protein degradation resumed, and no protein could be detected by the end of the experiment. In addition, a laboratory experiment was conducted to study the persistence of Cry1Ac protein released from rice tissue in water and paddy soil. The protein released from leaves degraded rapidly in paddy soil under flooded conditions during the first 20 d and plateaued until the termination of this trial at 135 d, when 15.3% of the initial amount was still detectable. In water, the Cry1Ac protein degraded more slowly than in soil but never entered a relatively stable phase as in soil. The degradation rate of Cry1Ac protein was significantly faster in nonsterile water than in sterile water. These results indicate that the soil environment can increase the degradation of Bt protein contained in plant residues. Therefore, plowing a field immediately after harvest could be an effective method for decreasing the persistence of Bt protein in transgenic rice fields.

  9. A Comparison of Entomopathogenic Nematode Longevity in Soil under Laboratory Conditions.

    PubMed

    Shapiro-Ilan, David I; Stuart, Robin J; McCoy, Clayton W

    2006-03-01

    We compared the longevity of 29 strains representing 11 entomopathogenic nematode species in soil over 42 to 56 d. A series of five laboratory experiments were conducted with six to eight nematode strains in each and one or more nematode strains in common, so that qualitative comparisons could be made across experiments. Nematodes included Heterorhabditis bacteriophora (four strains), H. indica (Homl), H. marelatus (Point Reyes), H megidis (UK211), H. mexicana (MX4), Steinernema carpocapsae (eight strains), S. diaprepesi, S. feltiae (SN), S. glaseri (NJ43), S. rarum (17C&E), and S. riobrave (nine strains). Substantial within-species variation in longevity was observed in S. carpocapsae, with the Sal strain exhibiting the greatest survival. The Sal strain was used as a standard in all inter-species comparisons. In contrast, little intra-species variation was observed in S. riobrave. Overall, we estimated S. carpocapsae (Sal) and S. diaprepesi to have the highest survival capability. A second level of longevity was observed in H. bacteriophora (Lewiston), H. megidis, S. feltiae, and S. riobrave (3-3 and 355). Lower levels of survivability were observed in other H. bacteriophora strains (Hb, HP88, and Oswego), as well as S. glaseri and S. rarum. Relative to S. glaseri and S. rarum, a lower tier of longevity was observed in H. indica and H. marelatus, and in H. mexicana, respectively. Although nematode persistence can vary under differing soil biotic and abiotic conditions, baseline data on longevity such as those reported herein may be helpful when choosing the best match for a particular target pest.

  10. Corrosion of aluminum and copper thin films under simulated atmospheric conditions in laboratory tests

    SciTech Connect

    Li, W.; Raman, A.; Diwan, R.; Bhattacharya, P.K.

    1998-12-31

    Corrosion characteristics of Al and Cu thin films have been studied in cyclic fog tests using tap water fog and fog created with 0.1% NaCl solution in tap water. Likewise, their corrosion features have been analyzed in continuous immersion testing in the laboratory in distilled water, tap water, in 0.1% NaCl and 3.5% NaCl solutions in distilled water. The corrosion potentials and the corrosion currents of these thin films change and reach steady state values after some time. However, steady state is not realized in 3.5% NaCl solutions. The corrosion current density data have been used to calculate lifetime of 1 {mu}m thick thin films of Al and Cu in the various tests, and assuming that the fog test data would hold under normal exposure conditions, life spans for these thin film sensor elements in actual exterior exposure have also been calculated. According to estimates, an Al-TF of about 1 {mu}m would last about 9 months in exterior exposure in chloride containing atmospheres, such as in the coastal regions, but would survive nearly 2 years in normal atmospheres not having acidic or chloride pollutants. On the contrary, 1 {mu}m thick Cu-TF would last only for about 2.5 months in chloride-laden environments, but would last for about 2 years in normal atmospheres. However, Cu-TF would be corroded off faster in slightly alkaline atmospheric condensate under total immersion situation. Lifetime estimates are presented and discussed.

  11. Laboratory study of CH4-N2 clathrate hydrates applied to Titan's surface conditions

    NASA Astrophysics Data System (ADS)

    Nna Mvondo, D.; Tobie, G.; Le Menn, E.; Bollengier, O.; Grasset, O.

    2013-12-01

    It is proposed that clathrate hydrates may be present at the surface of Titan (Choukroun et al., 2013, 2010). At Titan's surface pressure, pure methane and ethane hydrate (as well as other guests) could exist in the sI structure and nitrogen hydrate as sII structure. The large reservoir of several guest compounds in Titan's atmosphere is expected to result in the formation of multicomponent (compound) clathrate hydrates, as sII or sH structures, stable relative to water ice on the surface of Titan, and with faster expected growth kinetics relative to pure hydrate (Osegovic et al., 2005). Compound hydrate could be a likely sink for many chemicals occurring on Titan's surface. We note that experimental studies on the formation and thermodynamics of the methane-water system, at low and high pressures applied to Titan have been carried out (Lunine and Stevenson; 1985; Choukroun et al., 2013, 2010 and references therein). However, laboratory work on mixing of methane with other compounds in the clathrate phase (ethane, N2, CO2, etc...) applied to Titan conditions (and other icy moons) has still to be addressed. In this context, we have studied the formation and spectral signatures of CH4-N2 clathrate hydrates at temperature and pressure conditions relevant for Titan's surface. Clathrate hydrates samples have been synthesized in an autoclave combined with a cooling system and a multi-gas mixer. Few ml of deionized water was introduced in the autoclave and pressurized with the N2 and CH4 gaseous species for a couple of days, at controlled low temperature and low pressure of the formation and stability of clathrate hydrates. Their formation has been monitored by gas chromatography. Their spectral characterization at low temperature was performed by infrared (FTIR) reflectance spectroscopy. Raman spectroscopy was also used to give constraints on the composition, structure and cage occupancy of the formed clathrates. Here we present the results obtained for different mixing

  12. PROTOCOL FOR LABORATORY TESTING OF CRUDE-OIL BIOREMEDIATION PRODUCTS IN FRESHWATER CONDITIONS

    EPA Science Inventory

    In 1993, the Environmental Protection Agency, National Risk Management Research Laboratory (EPA, NRMRL), with the National Environmental Technology Application Center (NETAC), developed a protocol for evaluation of bioremediation products in marine environments. The marine proto...

  13. Moving from the laboratory to the field: Adding natural environmental conditions to toxicology testing

    EPA Science Inventory

    While laboratory toxicology tests are generally easy to perform, cost effective and readily interpreted, they have been criticized for being unrealistic. In contrast, field tests are considered realistic while producing results that are difficult to interpret and expensive. To ...

  14. Assessing the Exposure and Relative Sensitivity of Native Freshwater Mussels to Environmental Stressors and Laboratory Conditions

    EPA Science Inventory

    1. Expands the database for pesticide toxicity on native freshwater mussels. 2. Aids in determining any potential differences in toxic sensitivity of gravid female mussel attributed to age and laboratory holding times. 3. Aids in determining potential differences in juvenile ...

  15. Do Laboratory Results Concerning High-Viscosity Glass-Ionomers versus Amalgam for Tooth Restorations Indicate Similar Effect Direction and Magnitude than that of Controlled Clinical Trials? - A Meta-Epidemiological Study

    PubMed Central

    Mickenautsch, Steffen; Yengopal, Veerasamy

    2015-01-01

    Background A large percentage of evidence concerning dental interventions is based on laboratory research. The apparent wealth of laboratory evidence is sometimes used as basis for clinical inference and recommendations for daily dental practice. In this study two null-hypotheses are tested: whether trial results from laboratory and controlled clinical trials concerning the comparison of high-viscosity glass-ionomer cements (HVGIC) to amalgam for restorations placed in permanent posterior teeth have: (i) similar effect direction and (ii) similar effect magnitude. Methods 7 electronic databases were searched, as well as reference lists. Odds ratios (OR) and Standardised Mean Differences (SMD) with 95% Confidence intervals were computed for extracted dichotomous and continuous data, respectively. Pooled effect estimates for laboratory and clinical data were computed to test for effect direction. Odds ratios were converted into SMDs. SMDs from laboratory and clinical data were statistically compared to test for differences in effect magnitude. The analysed results were further investigated within the context of potential influencing or confounding factors using a Directed acyclic graph. Results Of the accepted eight laboratory and nine clinical trials, 13 and 21 datasets could be extracted, respectively. The pooled results of the laboratory datasets were highly statistically significant in favor of amalgam. No statistically significant differences, between HVGICs and amalgam, were identified for clinical data. For effect magnitude, statistically significant differences between clinical and laboratory trial results were found. Both null-hypotheses were rejected. Conclusion Laboratory results concerning high-viscosity glass-ionomers versus amalgam for tooth restorations do not indicate similar effect direction and magnitude than that of controlled clinical trials. PMID:26168274

  16. 42 CFR 410.32 - Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 2 2013-10-01 2013-10-01 false Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions. 410.32 Section 410.32 Public Health CENTERS FOR MEDICARE... (SMI) BENEFITS Medical and Other Health Services § 410.32 Diagnostic x-ray tests, diagnostic...

  17. 42 CFR 410.32 - Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 2 2011-10-01 2011-10-01 false Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions. 410.32 Section 410.32 Public Health CENTERS FOR MEDICARE... (SMI) BENEFITS Medical and Other Health Services § 410.32 Diagnostic x-ray tests, diagnostic...

  18. 42 CFR 410.32 - Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 2 2012-10-01 2012-10-01 false Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions. 410.32 Section 410.32 Public Health CENTERS FOR MEDICARE... (SMI) BENEFITS Medical and Other Health Services § 410.32 Diagnostic x-ray tests, diagnostic...

  19. 42 CFR 410.32 - Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 2 2014-10-01 2014-10-01 false Diagnostic x-ray tests, diagnostic laboratory tests, and other diagnostic tests: Conditions. 410.32 Section 410.32 Public Health CENTERS FOR MEDICARE... (SMI) BENEFITS Medical and Other Health Services § 410.32 Diagnostic x-ray tests, diagnostic...

  20. Numerical Simulation of Rock Fracturing under Laboratory True-Triaxial Stress Conditions

    NASA Astrophysics Data System (ADS)

    Ghofrani Tabari, Mehdi; Hazzard, Jim; Young, R. Paul

    2016-04-01

    A True-triaxial test (TTT) also known as polyaxial test was carried out on saturated Fontainebleau sandstone to elevate our knowledge about the role of the intermediate principal stress on deformation, fracturing and failure patterns of the rock using acoustic emission (AE) monitoring. The induced AE activities were studied by location of the AE events and mapping them on the captured features in the post-mortem CT scan images of the failed sample. The time-lapse monitoring of the velocity structure and AE activity in the sample portrayed a deformational path which led to propagation of fractures and formation of failure patterns in the rock. Having these experimental results, we aimed at running a numerical model of our true-triaxial testing system using an Itasca software based on three-dimensional explicit finite-difference method called FLAC3D. The loads were applied at the end of each platen while the steel platens transferred the stress to the surface of the cubic specimen. In order to simulate the failure, randomly distributed strength demonstrated by Mohr-Columb failure criterion was implemented in the spatial elements of the model representing the random distribution of the micro-cracks. During the experiment, pseudo-boundary surfaces were formed along the minimum and intermediate principal stress axes in the rock due to non-uniform distribution of stress as a result of geometrical constraints including the corner effects and friction on the platen-rock surfaces. Both the real AE data as well as the numerical simulation verified that coalescence of micro-cracks mainly occurred around these pseudo-boundaries with highest stress gradients as well as highest velocity gradients in the rock specimen and formed curvi-planar fractures. The rock specimen strength and brittleness in the macro-scale was also obtained from the stress-strain curve which was consistent with the experimental laboratory measurements. Eventually, the failure of the rock specimen was

  1. Comparative performances, under laboratory conditions, of seven pyrethroid insecticides used for impregnation of mosquito nets.

    PubMed Central

    Hougard, Jean-Marc; Duchon, Stéphane; Darriet, Frédéric; Zaim, Morteza; Rogier, Christophe; Guillet, Pierre

    2003-01-01

    OBJECTIVE: To compare the efficacy of seven pyrethroid insecticides for impregnation of mosquito nets, six currently recommended by WHO and one candidate (bifenthrin), under laboratory conditions. METHODS: Tests were conducted using pyrethroid-susceptible and pyrethroid-resistant strains of Anopheles gambiae and Culex quinquefasciatus. Knock-down effect, irritancy and mortality were measured using standard WHO cone tests. Mortality and blood-feeding inhibition were also measured using a baited tunnel device. FINDINGS: For susceptible A. gambiae, alpha-cypermethrin had the fastest knock-down effect. For resistant A. gambiae, the knock- down effect was slightly slower with alpha-cypermethrin and much reduced following exposure to the other insecticides, particularly bifenthrin and permethrin. For susceptible C. quinquefasciatus, the knock-down effect was significantly slower than in A. gambiae, particularly with bifenthrin, and no knock-down effect was observed with any of the pyrethroids against the resistant strain. Bifenthrin was significantly less irritant than the other pyrethroids to susceptible and resistant A. gambiae but there was no clear ranking of pyrethroid irritancy against C. quinquefasciatus. In tunnels, all insecticides were less toxic against C. quinquefasciatus than against A. gambiae for susceptible strains. For resistant strains, mortality was significant with all the pyrethroids with A. gambiae but not with C. quinquefasciatus. Inhibition of blood-feeding was also high for susceptible strains of both species and for resistant A. gambiae but lower for resistant C. quinquefasciatus; bifenthrin had the greatest impact. CONCLUSIONS: Efficacy for impregnation of mosquito nets against A. gambiae was greatest with alpha-cypermethrin. Bifenthrin is likely to have a significant comparative advantage over other pyrethroids in areas with pyrethroid resistance because of its much stronger impact on the nuisance mosquito, C. quinquefasciatus, despite its

  2. Juvenile roach (Rutilus rutilus) increase their anaerobic metabolism in response to copper exposure in laboratory conditions.

    PubMed

    Maes, Virginie; Betoulle, Stéphane; Jaffal, Ali; Dedourge-Geffard, Odile; Delahaut, Laurence; Geffard, Alain; Palluel, Olivier; Sanchez, Wilfried; Paris-Palacios, Séverine; Vettier, Aurélie; David, Elise

    2016-07-01

    This study aims to determine the potential impairment of cell energy synthesis processes (glycolysis and respiratory chain pathways) by copper in juvenile roach at different regulation levels by using a multi-marker approach. Juvenile roach were exposed to 0, 10, 50, and 100 µg/L of copper for 7 days in laboratory conditions. The glycolysis pathway was assessed by measuring the relative expression levels of 4 genes encoding glycolysis enzymes. The respiratory chain was studied by assessing the electron transport system and cytochrome c oxidase gene expression. Muscle mitochondria ultrastructure was studied, and antioxidant responses were measured. Furthermore, the main energy reserves-carbohydrates, lipids, and proteins-were measured, and cellular energy was evaluated by measuring ATP, ADP, AMP and IMP concentrations. This study revealed a disturbance of the cell energy metabolism due to copper exposure, with a significant decrease in adenylate energy charge in roach exposed to 10 μg/L of copper after 1 day. Moreover, ATP concentrations significantly decreased in roach exposed to 10 μg/L of copper after 1 day. This significant decrease persisted in roach exposed to 50 µg/L of copper after 7 days. AMP concentrations increased in all contaminated fish after 1 day of exposure. In parallel, the relative expression of 3 genes encoding for glycolysis enzymes increased in all contaminated fish after 1 day of copper exposure. Focusing on the respiratory chain, cytochrome c oxidase gene expression also increased in all contaminated fish at the two time-points. The activity of the electron transport system was not disturbed by copper, except in roach exposed to 100 µg/L of copper after 1 day. Copper induced a metabolic stress. Juvenile roach seemed to respond to the ensuing high energy demand by increasing their anaerobic metabolism, but the energy produced by the anaerobic metabolism is unable to compensate for the stress induced by copper after 7

  3. Laboratory experiments to explore the sediment transport capacity of carbon dioxide sublimation under martian conditions

    NASA Astrophysics Data System (ADS)

    Sylvest, Matthew; Conway, Susan; Patel, Manish; Dixon, John; Barnes, Adam

    2015-04-01

    Every spring, the solid carbon dioxide deposited over the martian high latitudes sublimates. Several, unusual surface features, including dark spots and flows on sand dunes, as well as recent activity in martian gullies, have been associated with this CO2 sublimation. Water and/or brines have also been proposed as potential agents for these events, but the timing of these phenomena suggest CO2 sublimation is more likely. However, the exact mechanism by which CO2 sublimation moves sediment is not fully understood, and this understanding is required to validate the CO2 hypothesis. Here we present the results of the first ever laboratory simulations of this process under martian conditions, and show that significant quantities of loose sediment can be transported. The centrepiece of the apparatus is a 1m diameter, 2m long Mars simulation chamber, housed at The Open University, UK. JSC Mars-1A regolith simulant was formed into a slope, inside a box, ~30 cm long, 23 cm wide by 12 cm deep. The box is constructed of coiled, copper tubing to allow cooling of the regolith by liquid nitrogen. The experimental procedure consists of four stages: 1) establishment of a dry atmosphere in the chamber, 2) cooling the regolith sufficiently to support condensation of CO2 frost at reduced pressure, 3) introduction of cooled CO2 gas above the regolith to deposit as frost, and 4) video recording the surface evolution under radiant heating (~100 mins). Two High Definition digital video cameras were mounted above the box and image pairs taken from the videos were then used to create digital elevation models (DEMs) in Agisoft Photoscan at regular intervals. In our initial experiments we performed four experimental runs where the slope was set at or near the angle of repose (~30°). In each case we observed mass wasting events triggered by the sublimation of the deposited CO2 over the whole duration of the insolation. The highest levels of activity occurred in the first third of the run

  4. A comparison of factors involved in starch degradation in barley germination under laboratory and malting conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grains of the malting barley cultivar Legacy were laboratory germinated (LG) or micromalted (MM) and sampled daily from 0 to 5 days after imbibition/steeping. Alpha-amylase and beta-amylase activities and protein levels along with starch, osmolyte concentration (OC), and sugar (glucose, sucrose, fr...

  5. Use of filter paper as a transport medium for laboratory diagnosis of cholera under field conditions.

    PubMed

    Page, Anne-Laure; Alberti, Kathryn P; Guénolé, Alain; Mondongue, Vital; Lonlas Mayele, Sylvaine; Guerin, Philippe J; Quilici, Marie-Laure

    2011-08-01

    Confirmation of a cholera epidemic is based on bacteriological identification of the agent and requires the sending of samples to a culture laboratory, often in countries with limited resources. Comparison of the use of filter paper with the use of Cary-Blair reference medium for stool transport showed that this simple transport medium is appropriate for the recovery of Vibrio cholerae.

  6. Behavioral responses of Aedes aegypti to DUETTM and its two components under laboratory conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DUETTM is an insecticide composed of two active ingredients (1% prallethrin and 5% sumithrin) that is applied as an ultra low volume (ULV) spray to kill adult mosquitoes. It has previously been shown to activate Culex quinquefasciatus females in the laboratory resulting in greater mortality. Formu...

  7. Temporary inhibition of dorsal or ventral hippocampus by muscimol: distinct effects on measures of innate anxiety on the elevated plus maze, but similar disruption of contextual fear conditioning.

    PubMed

    Zhang, Wei-Ning; Bast, Tobias; Xu, Yan; Feldon, Joram

    2014-04-01

    Studies in rats, involving hippocampal lesions and hippocampal drug infusions, have implicated the hippocampus in the modulation of anxiety-related behaviors and conditioned fear. The ventral hippocampus is considered to be more important for anxiety- and fear-related behaviors than the dorsal hippocampus. In the present study, we compared the role of dorsal and ventral hippocampus in innate anxiety and classical fear conditioning in Wistar rats, examining the effects of temporary pharmacological inhibition by the GABA-A agonist muscimol (0.5 ug/0.5 ul/side) in the elevated plus maze and on fear conditioning to a tone and the conditioning context. In the elevated plus maze, dorsal and ventral hippocampal muscimol caused distinct behavioral changes. The effects of ventral hippocampal muscimol were consistent with suppression of locomotion, possibly accompanied by anxiolytic effects, whereas the pattern of changes caused by dorsal hippocampal muscimol was consistent with anxiogenic effects. In contrast, dorsal and ventral hippocampal muscimol caused similar effects in the fear conditioning experiments, disrupting contextual, but not tone, fear conditioning.

  8. Laboratory appraisal of optimal gaseous conditions for growth of zoonotic Helicobacter felis ATCC 49179.

    PubMed

    Shiohara, Mayumi; Kawakubo, Masatomo; Matsumoto, Takehisa; Kumagai, Toshiko; Yamauchi, Kazuyoshi; Oana, Kozue; Ota, Hiroyoshi; Kawakami, Yoshiyuki

    2009-05-01

    An attempt was made to assess the hitherto undescribed optimal gaseous conditions for growth of zoonotic Helicobacter felis, focusing on the ratio of spiral-forms amongst the whole cells examined. The largest mean colony diameter was obtained under the gaseous condition of O(2) 12% and CO(2) 10%. In analyzing the five day old colonies, the highest percentage of spiral forms (85.5%) was observed under the condition of O(2) 18% and CO(2) 5%. In contrast, the lowest percentage of spiral forms (2.3%) was demonstrated under the condition of O(2) 1% and CO(2) 10%. The condition of O(2) 12% and CO(2) 10% was concluded to be optimal for obtaining cells with the largest colony sizes, although colonies proliferated under such conditions definitely contain many more coccoid cells than spiral forms. In culturing H. felis strains, optimal gaseous conditions should be employed according to the purposes or preferences of study designs.

  9. Spawning of zebra mussels (Dreissena polymorpha) and rearing of veligers under laboratory conditions

    USGS Publications Warehouse

    Nichols, S. Jerrine; Nalepa, Thomas F.; Schloesser, Donald W.

    1992-01-01

    The spawning cycle of the zebra mussel, Dreissena polymorpha, is amenable to laboratory manipulations. Techniques are presented that can be used to initiate spawning and rear veligers from fertilized egg to settlement stage. Spawning can be induced in sexually mature mussels by temperature flucuations or by the addition of ripe gametes. Embryonic survival is excellent until the straight-hinge stage when the first wave of mortality occurs, usually due to improper food. The second critical stage of development occurs just prior to settlement when mortality increases again. Veliger mortality averaged over 90% from egg to settlement. The results indicate that obtaining large numbers of veligers for laboratory experiments to be conducted year-round is difficult.

  10. Employee motivation in laboratory animal science: creating the conditions for a happy and productive staff.

    PubMed

    Chick, John F

    2006-01-01

    High rates of employee turnover are the source of a considerable loss of time and resources, but managers are not always aware of the reasons that motivate employees to stay in their positions. The author compares prominent theories of employee motivation and then puts them to the test by surveying 82 cagewashers, animal caretakers, animal technicians, and supervisors working in a laboratory animal facility to determine the job characteristics that motivate them.

  11. Reproductive and post-reproductive life history of wild-caught Drosophila melanogaster under laboratory conditions.

    PubMed

    Klepsatel, P; Gáliková, M; De Maio, N; Ricci, S; Schlötterer, C; Flatt, T

    2013-07-01

    The life history of the fruit fly (Drosophila melanogaster) is well understood, but fitness components are rarely measured by following single individuals over their lifetime, thereby limiting insights into lifetime reproductive success, reproductive senescence and post-reproductive lifespan. Moreover, most studies have examined long-established laboratory strains rather than freshly caught individuals and may thus be confounded by adaptation to laboratory culture, inbreeding or mutation accumulation. Here, we have followed the life histories of individual females from three recently caught, non-laboratory-adapted wild populations of D. melanogaster. Populations varied in a number of life-history traits, including ovariole number, fecundity, hatchability and lifespan. To describe individual patterns of age-specific fecundity, we developed a new model that allowed us to distinguish four phases during a female's life: a phase of reproductive maturation, followed by a period of linear and then exponential decline in fecundity and, finally, a post-ovipository period. Individual females exhibited clear-cut fecundity peaks, which contrasts with previous analyses, and post-peak levels of fecundity declined independently of how long females lived. Notably, females had a pronounced post-reproductive lifespan, which on average made up 40% of total lifespan. Post-reproductive lifespan did not differ among populations and was not correlated with reproductive fitness components, supporting the hypothesis that this period is a highly variable, random 'add-on' at the end of reproductive life rather than a correlate of selection on reproductive fitness. Most life-history traits were positively correlated, a pattern that might be due to genotype by environment interactions when wild flies are brought into a novel laboratory environment but that is unlikely explained by inbreeding or positive mutational covariance caused by mutation accumulation.

  12. Conditions for building a community of practice in an advanced physics laboratory

    NASA Astrophysics Data System (ADS)

    Irving, Paul W.; Sayre, Eleanor C.

    2014-06-01

    We use the theory of communities of practice and the concept of accountable disciplinary knowledge to describe how a learning community develops in the context of an upper-division physics laboratory course. The change in accountable disciplinary knowledge motivates students' enculturation into a community of practice. The enculturation process is facilitated by four specific structural features of the course and supported by a primary instructional choice. The four structural features are "paucity of instructor time," "all in a room together," "long and difficult experiments," and "same experiments at different times." The instructional choice is the encouragement of the sharing and development of knowledge and understanding by the instructor. The combination of the instructional choice and structural features promotes the development of the learning community in which students engage in authentic practices of a physicist. This results in a classroom community that can provide students with the opportunity to have an accelerated trajectory towards being a more central participant of the community of a practice of physicists. We support our claims with video-based observations of laboratory classroom interactions and individual, semistructured interviews with students about their laboratory experiences and physics identity.

  13. 42 CFR 416.49 - Condition for coverage-Laboratory and radiologic services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... HEALTH AND HUMAN SERVICES (CONTINUED) MEDICARE PROGRAM AMBULATORY SURGICAL SERVICES Specific Conditions... services from a Medicare approved facility to meet the needs of patients. (2) Radiologic services must...

  14. Molecular similarity and property similarity.

    PubMed

    Barbosa, Frédérique; Horvath, Dragos

    2004-01-01

    This paper reviews the main efforts undertaken up to date in order to understand, rationalize and apply the similarity principle (similar compounds=>similar properties) as a computational tool in modern drug discovery. The best suited mathematical expression of this classical working hypothesis of medicinal chemistry needs to be carefully chosen (out of the virtually infinite possible implementations in terms of molecular descriptors and molecular similarity metrics), in order to achieve an optimal validation of the hypothesis that molecules that are neighbors in the Structural Space will also display similar properties. This overview will show why no single "absolute" measure of molecular similarity can be conceived, and why molecular similarity scores should be considered tunable tools that need to be adapted to each problem to solve.

  15. Organic intermediates in the anaerobic biodegradation of coal to methane under laboratory conditions

    USGS Publications Warehouse

    Orem, W.H.; Voytek, M.A.; Jones, E.J.; Lerch, H.E.; Bates, A.L.; Corum, M.D.; Warwick, P.D.; Clark, A.C.

    2010-01-01

    Organic intermediates in coal fluids produced by anaerobic biodegradation of geopolymers in coal play a key role in the production of methane in natural gas reservoirs. Laboratory biodegradation experiments on sub-bituminous coal from Texas, USA, were conducted using bioreactors to examine the organic intermediates relevant to methane production. Production of methane in the bioreactors was linked to acetate accumulation in bioreactor fluid. Long chain fatty acids, alkanes (C19-C36) and various low molecular weight aromatics, including phenols, also accumulated in the bioreactor fluid and appear to be the primary intermediates in the biodegradation pathway from coal-derived geopolymers to acetate and methane. ?? 2010.

  16. Pressure-Water Content Relations for a Sandy, Granitic Soil Under Field and Laboratory Conditions

    NASA Astrophysics Data System (ADS)

    Chandler, D. G.; McNamara, J. M.; Gribb, M. M.

    2001-12-01

    A new sensor was developed to measure soil water potential in order to determine the predominant mechanisms of snowmelt delivery to streamflow. The sensors were calibrated for +50 to -300 cm for application on steep granitic slopes and deployed at three depths and 2 locations on a slope in a headwater catchment of the Idaho Batholith throughout the 2001 snowmelt season. Soil moisture was measured simultaneously with Water Content Reflectometers (Cambell Scientific, Logan, UT), that were calibrated in situ with Time Domain Reflectometry measurements. Sensor performance was evaluated in a laboratory soil column via side-by-side monitoring during injection of water with a cone permeameter. Soil characteristic curves were also determined for the field site by multi-step outflow tests. Comparison of the results from the field study to those from the laboratory experiment and to the characteristic curves demonstrate the utility of the new sensor for recording dynamic changes in soil water status. During snowmelt, the sensor responded to both matric potential and bypass-flow pore potential. Large shifts in the pressure record that correspond to changes in the infiltration flux indicate initiation and cessation of macropore flow. The pore pressure records may be used to document the frequency, timing and duration of bypass flow that are not apparent from the soil moisture records.

  17. Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Steffes, Paul G.

    1989-01-01

    Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. Work performed has shown that laboratory measurements of the millimeter-wave opacity of ammonia between 7.5 mm and 9.3 mm and also at the 3.2 mm wavelength require a different lineshape to be used in the theoretical prediction for millimeter-wave ammonia opacity than was previously used. The recognition of the need to make such laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressures which correspond to the altitudes probed by both radio occultation experiments and radio astronomical observations, and over a range of frequencies which correspond to those used in both radio occultation experiments and radio astronomical observations, has led to the development of a facility at Georgia Tech which is capable of making such measurements. It has been the goal of this investigation to conduct such measurements and to apply the results to a wide range of planetary observations, both spacecraft and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres.

  18. Evaluating Membrane Processes for Air Conditioning; Highlights in Research and Development, NREL (National Renewable Energy Laboratory)

    SciTech Connect

    2015-06-01

    This NREL Highlight discusses a recent state-of-the-art review of membrane processes for air conditioning that identifies future research opportunities. This highlight is being developed for the June 2015 S&T Alliance Board meeting.

  19. The Effects of Outer Flow Conditions on the Emergence and Evolution of Geometrical Self Similarity of a Bluff Body during Ablation

    NASA Astrophysics Data System (ADS)

    Allard, Michael; White, Christopher M.

    2016-11-01

    The ablation process (i.e., erosion) of a bluff body, low-temperature ablator is investigated. Two experimental configurations in a heated open-circuit thermal boundary layer wind tunnel are considered: (a) the bluff body is supported in the free stream or (b) placed within the boundary layer growing on the bottom wall of the tunnel. These two configurations were chosen to investigate the effects of outer flow conditions (i.e. uniform in the free stream and varying with the boundary layer) on the emergence and evolution of geometrical self similarity during ablation. A time sequence of streamwise-transverse and streamwise-wall normal images were recorded. The images were analyzed to investigate the temporal evolution of the bluff body's projected area, perimeter, and curvature. The results were compared to similar studies where the erosion was caused from fluid shear force and chemical dissolution both of which scaled-similarly. The insights gained from this study can be used to progress towards physics-based models of bluff body ablation. This work is supported by the NSF (CBET-0967224).

  20. Assessing the Fate of Litter Mercury during Decomposition under Controlled Laboratory Conditions

    NASA Astrophysics Data System (ADS)

    Pokharel, A. K.; Obrist, D.

    2009-12-01

    The goal of this research is to assess the fate of mercury (Hg) in forest litter during decomposition under controlled laboratory incubations and in the field. During decomposition, Hg may be lost to the atmosphere by gaseous elemental mercury evasion, may become soluble and subject to runoff, or may remain sequestered in the remaining litter pool. We are conducting a laboratory incubation study over 18 months to monitor total litter dry mass, carbon, nitrogen, and Hg mass and concentrations, and the respective stochiometric ratios, of 100 well characterized litter samples. Fresh surface litter samples (~ 30 g) of four different forest types (mixed deciduous, aspen, pine, and blue Oak) were incubated in acid-cleaned glass jars covered by Teflon filters to allow gas exchange while avoiding particulate and dust deposition. Litter samples were kept at 25 degree celcius in the dark and kept moist by occasional addition of Hg free water. Samples were also extracted for soluble Hg to assess how decomposition may affect aqueous-phase Hg mobility. Additional litter samples were placed in the field to compare laboratory results to in situ field decomposition. Initial results after six months of decomposition show that dry mass of the four litter types decreased by 2-8% after 3 months and 3-11% after 6 months as compared to initial dry mass. Total Hg mass showed inconsistent patterns after 3 months (+3% to -6% mass change), but started to show consistent decreases (from 2 to 16%) after 6 months of incubation. Total amounts of soluble Hg extracted from litter samples showed decreasing solubility of Hg with increasing duration of incubation. Hence, our results show that dry mass and C losses during decomposition (through losses of CO2) did not lead to equal losses of atmospheric Hg during initial stages of decomposition, but that some losses of Hg are becoming visible after six months, albeit strongly dependent on litter types. Decomposition of surface litter may hence be

  1. Laboratory Measurements on Heterogeneous Nucleation and Growth of Water Vapor on Meteor Smoke Particle Analogues under Conditions of the Mesopause

    NASA Astrophysics Data System (ADS)

    Duft, D.; Nachbar, M.; Wilms, H.; Rapp, M.; Leisner, T.

    2014-12-01

    Heterogeneous nucleation of water vapor on charged nanometer sized (radius< 2nm) meteor smoke particles (MSP) is believed to be the dominating nucleation process in the mesopause region leading to the formation of polar mesospheric clouds (PMC). However, application of classical nucleation theory to the cold conditions of the polar summer mesopause comprises large uncertainties giving rise to strongly variant model predictions of PMC formation. To reduce these uncertainties laboratory measurements of nucleation and growth rates are required. We use an electrodynamic trap to investigate the nucleation and growth of water vapor on singly charged sub-3nm MSP analogues in the laboratory under mesospheric conditions typical during PMC growth initiation. The particles are created in a microwave plasma particle source and stored in a quadrupole ion trap under mesospheric pressure and temperature, where they are subjected to the high supersaturation necessary for nucleation and growth on nanometer sized particles. The particle mass and mass change by water accretion is monitored with a time-of-flight mass spectrometer as a function of residence time under supersaturated conditions. In this contribution we present for the first time measurements of nucleation and growth rates of water vapor on MSP analogues with an initial radius between 1.5nm and 3 nm. Contact parameter, sticking coefficient as well as charge effects on vapor pressure of small particles at mesospheric conditions are presented. These parameters are essential for the microphysical understanding and further global model calculations of PMC formation.

  2. Marks caused by the scavenging activity of Necrobia rufipes (Coleoptera: Cleridae) under laboratory conditions.

    PubMed

    Zanetti, Noelia I; Visciarelli, Elena C; Centeno, Néstor D

    2015-07-01

    Insects are an important group involved in carrion consumption and are thus of forensic interest. In the laboratory we studied the taphonomic marks that Necrobia rufipes (Cleridae) can produce. Pig trotters were exposed to adult beetles at 21 ± 3 °C and 12:12 h day/night cycle. We made observations and took photographs every 4-5 days for 12 months. Marks were noted after a month. We found scratches, pits, holes, and tunnels in several kinds of tissue such as integumental, connective and muscular. This work contributes preliminary data of significant application in biology, ecology, anthropology and forensics. Until now, no study has provided taphonomic information with N. rufipes.

  3. Predation by odonate nymphs on larval razorback suckers (Xyrauchen texanus) under laboratory conditions

    USGS Publications Warehouse

    Horn, Michael J.; Marsh, Paul C.; Mueller, Gordon; Burke, Tom

    1994-01-01

    High larval mortality has plagued efforts to raise razorback suckers (Xyrauchen texanus) in a Lake Mohave, Arizona-Nevada backwater. Observations indicate odonate nymph densities may be high enough to impact larval survival. In laboratory tests conducted in aquaria, damselfly (Coenagrionidae: Enallagma sp.) and dragonfly (Libellulidae: Tramea sp.) nymphs consumed 81% and 76% respectively of 11.8 ± 0.7 mm total length larval razorbacks in 7 days compared to 12% mortality in controls. Larger razorback larvae (14 to 15 mm TL) were less susceptible than smaller fish, showing 53% mortality versus 18% in controls. Extensive growth of sago pondweed (Potamogeton pectinatus) may exacerbate predation effects in the backwater, by allowing odonates access to more of the water column.

  4. Snapping shrimp prefer natural as opposed to artificial materials as their habitat in laboratory conditions

    NASA Astrophysics Data System (ADS)

    Sim, Lai Kean; Ghazali, Shahriman M.

    2014-09-01

    This study analyzed the habitat selection behavior of the snapping shrimp, Alpheus spp., comparing natural shelters (Rocks with oysters attached on the surface Sh; rocks with smooth surface, Ro and coral rubble, Co with plastic bottle. Controlled laboratory experiments were conducted to assess the habitat preference, effect of photoperiod and shrimp orientation at shelter. The current study indicated that snapping shrimp preferred natural materials but rejected plastic bottle as their shelter. Among the natural shelters, coral rubble was the most preferred habitat followed by shell and rock. Photoperiod showed minimum effect on the shrimp where they spend most of the time inside and underneath the shelters. In conclusion the current study showed that snapping shrimp preferred coral rubble as opposed to other natural material and plastic bottle. The result also suggested that plastic debris in the marine environment is not an alternative habitat for snapping shrimp.

  5. Effect of population density on reproduction in Microtus fortis under laboratory conditions.

    PubMed

    Han, Qunhua; Zhang, Meiwen; Guo, Cong; Shen, Guo; Wang, Yong; Li, Bo; Xu, Zhenggang

    2014-06-01

    Between December 2011 and March 2012, the reproductive characteristics of Microtus fortis reared in the laboratory at different population densities were assessed. In all, 258 male and female voles were randomly divided into 4 groups and reared at densities of 2, 4, 6, and 8 animals per cage (sex ratio: 1:1). The results showed that the pregnancy rate (χ2 = 21.671, df = 3, P < 0.001) and first farrowing interval (F = 12.355, df = 3, P < 0.001) were significantly different among the different population density groups, but the mean litter size (mean ± SD) was not (F = 2.669, df = 3, P > 0.05). In particular, the reproductive index and sex hormone levels showed a significant difference among the different density groups studied.

  6. Population analysis of Aedes albopictus (Skuse) (Diptera:Culicidae) under uncontrolled laboratory conditions.

    PubMed

    Nur Aida, H; Abu Hassan, A; Nurita, A T; Che Salmah, M R; Norasmah, B

    2008-08-01

    A semi laboratory experiment using 3 cohorts of Aedes albopictus adults was performed to obtain age-specific mortality and fecundity information and to derive statistical estimates of some population growth parameters. Life expectancy was calculated for both males and females. The following population parameters were estimated: intrinsic rate of increase (rm= 0.21), net reproductive (replacement) rate (Ro= 68.70), age at mean cohort reproduction (To=10.55 days), birth rate (B=0.23), death rate (D=0.02) and generation time (G=20.14 days). The high rm/B (0.91) and B/D (11.50) ratios indicated the high colonizing ability of Ae. albopictus in nature.

  7. Parametrization of turbulence models using 3DVAR data assimilation in laboratory conditions

    NASA Astrophysics Data System (ADS)

    Olbert, A. I.; Nash, S.; Ragnoli, E.; Hartnett, M.

    2013-12-01

    In this research the 3DVAR data assimilation scheme is implemented in the numerical model DIVAST in order to optimize the performance of the numerical model by selecting an appropriate turbulence scheme and tuning its parameters. Two turbulence closure schemes: the Prandtl mixing length model and the two-equation k-ɛ model were incorporated into DIVAST and examined with respect to their universality of application, complexity of solutions, computational efficiency and numerical stability. A square harbour with one symmetrical entrance subject to tide-induced flows was selected to investigate the structure of turbulent flows. The experimental part of the research was conducted in a tidal basin. A significant advantage of such laboratory experiment is a fully controlled environment where domain setup and forcing are user-defined. The research shows that the Prandtl mixing length model and the two-equation k-ɛ model, with default parameterization predefined according to literature recommendations, overestimate eddy viscosity which in turn results in a significant underestimation of velocity magnitudes in the harbour. The data assimilation of the model-predicted velocity and laboratory observations significantly improves model predictions for both turbulence models by adjusting modelled flows in the harbour to match de-errored observations. Such analysis gives an optimal solution based on which numerical model parameters can be estimated. The process of turbulence model optimization by reparameterization and tuning towards optimal state led to new constants that may be potentially applied to complex turbulent flows, such as rapidly developing flows or recirculating flows. This research further demonstrates how 3DVAR can be utilized to identify and quantify shortcomings of the numerical model and consequently to improve forecasting by correct parameterization of the turbulence models. Such improvements may greatly benefit physical oceanography in terms of

  8. Containment testing of laboratory hoods in the as-used condition.

    PubMed

    Greenley, P L; Billings, C E; DiBerardinis, L J; Edwards, R W; Barkley, W E

    2000-02-01

    Airborne contaminants generated inside laboratory fume hoods during use leak into the breathing zone of the user. Concentration of the leakage is unknown and variable depending on laboratory design, work practices, arrangement of internal apparatus, face velocity, and sash height. Surrogate tracer gas tests have been developed using sulfur hexafluoride (SF6) and a manikin to estimate leakage. This study presents results of hood leakage tests using SF6 with a manikin and then a live operator performing a phenol:chloroform (P:C) extraction. Four hoods were tested in each of three institutions during normal work hours with the lab occupied. The purpose of the study was to determine leakage concentrations for the SF6-manikin with effects of sash height, hood contents as found and after being cleaned out, face velocity, and the actual P:C and SF6 exposure concentrations of the user during work. Results indicate P:C was not detectable in the breathing zone of the 12 operators (< 0.1 ppm) at their selected operating sash heights (7 to 15 inches). Simultaneous SF6 concentrations were also minimal (average 0.06 ppm). Average leakage was 0.02 percent for SF6 and less than 2 percent based on chloroform concentrations measured in the breathing zone of the operator and inside the hood. SF6 percent leakage was greater when sash height was above the breathing zone of the manikin (average 2.09 percent) and lower leakage (average 0.02 percent) when below the breathing zone (26 inches or less). Average face velocity did not appear to be a predictor of average hood leakage. Cleaning out the hoods did not reduce leakage in most tests. The data from this study shows that when providing training on proper work practices for lab hood use, lowering the sash should be stressed as being the major factor in reducing hood leakage.

  9. Laboratory evaluation of 10 heat and moisture exchangers using simulated aeromedical evacuation conditions.

    PubMed

    Suliman, Huda S; Fecura, Stephen E; Baskin, Jonathan; Kalns, John E

    2011-06-01

    Heat and moisture exchangers (HMEs) are used for airway humidification in mechanically ventilated patients and have been evaluated only under hospital conditions. U.S. Air Force aeromedical evacuation transports are performed under rugged conditions further complicated by the cold and dry environment in military aircrafts, and HMEs are used to provide airway humidification for patients. This study evaluated 10 commercial HMEs using a test system that simulated aeromedical evacuation conditions. Although the American National Standards Institute recommends inspired air to be at an absolute humidity value of > or = 30 mg/L for mechanically ventilated patients, the highest absolute humidity by any HME was approximately 20 mg/L. Although none of the HMEs were able to maintain a temperature high enough to achieve the humidity standard of the American National Standards Institute, the clinical significance of this standard may be less important than the relative humidity maintained in the respired air, especially on evacuation flights of short duration.

  10. Evaluation of efficacy of 18 strains of entomopathogenic nematodes (Rhabditida) against Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) under laboratory conditions.

    PubMed

    Barbosa Negrisoli, Carla Ruth de Carvalho; Negrisoli Júnior, Aldomario Santo; Botton, Marcos; Garcia, Mauro Silveira; Bernardi, Daniel

    2013-07-01

    Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) is an important plant virus vector in grapevine crops in Brazil and other countries. The mealybug grows in roots and leaves of the grapes. Entomopathogenic nematodes (EPNs) are efficient control agents against insects associated to the soil and could be applied with the same equipment used for chemical insecticides. The aim of this study was to select effective EPNs for controlling P. citri females in laboratory conditions (25±1°C, UR 60±10%). We tested 17 native [Steinernema rarum (6 strains), Steinernema glaseri, Steinernema feltiae, Steinernema riobrave, Steinernema sp., Heterorhabditis bacteriophora (7 strains)] and only one exotic strain (Steinernema carpocapsae ALL). The bioassays were done on Petri dishes infested with females of P. citri, which were sprayed with EPNs juveniles. The strain with larger pathogenicity and virulence in laboratory was H. bacteriophora RS33 (from 69.0% to 92.2% of mortality), native of Rio Grande do Sul.

  11. Survey of prevalence of overweight body condition in laboratory-housed cynomolgus macaques (Macaca fascicularis).

    PubMed

    Bauer, Sharon A; Leslie, Ken E; Pearl, David L; Fournier, Jocelyn; Turner, Patricia V

    2010-07-01

    Excessive weight gain has been reported to occur in captive cynomolgus macaques with little to no change in diet. Overweight body condition can result in development of hyperglycemia and type 2 diabetes and should be avoided. The purpose of this survey was to assess the prevalence of overweight cynomolgus macaques in North American research facilities, including breeding colonies and short-term and long-term facilities, and to describe current methods used to assess body condition. The survey consisted of 51 questions covering animal population demographics, body weight and body condition scoring, feeding, and behavior. Voluntary participants included veterinarians and animal care managers. Respondents from 13 facilities completed the survey, and information was collected on 17,500 cynomolgus macaques. The majority of surveyed facilities housed juvenile and young adult macaques. The reported prevalence of overweight (greater than 10% of ideal body weight) animals ranged between 0% and 20% and reportedly was more frequent in animals younger than 10 y. Most facilities had weight reduction strategies in place. Despite these programs, a significant proportion of animals were reported as being overweight. The results of this survey demonstrate that most North American facilities housing cynomolgus macaques recognize the importance of tracking body condition regularly. However, implementing effective weight reduction programs may be difficult in captive housing environments. Because of the potential for adverse health effects, facilities should have a means of regularly tracking body weight as well as an action plan for managing overweight animals.

  12. The impact of insecticides to local honey bee colony Apis cerana indica in laboratory condition

    NASA Astrophysics Data System (ADS)

    Putra, Ramadhani E.; Permana, Agus D.; Nuriyah, Syayidah

    2014-03-01

    Heavy use of insecticides considered as one of common practice at local farming systems. Even though many Indonesian researchers had stated the possible detrimental effect of insecticide on agriculture environment and biodiversity, researches on this subject had been neglected. Therefore, our purpose in this research is observing the impact of insecticides usage by farmer to non target organisme like local honey bee (Apis cerana indica), which commonly kept in area near agriculture system. This research consisted of field observations out at Ciburial, Dago Pakar, Bandung and laboratory tests at School of Life Sciences and Technology, Institut Teknologi Bandung. The field observations recorded visited agriculture corps and types of pollen carried by bees to the nest while laboratory test recorderd the effect of common insecticide to mortality and behavior of honey bees. Three types of insecticides used in this research were insecticides A with active agent Chlorantraniliprol 50 g/l, insecticide B with active agent Profenofos 500 g/l, and insecticides C with active agent Chlorantraniliprol 100 g/l and λ-cyhalotrin 50g/l. The results show that during one week visit, wild flower, Wedelia montana, visited by most honey bees with average visit 60 honey bees followed by corn, Zea mays, with 21 honey bees. The most pollen carried by foragers was Wedelia montana, Calliandra callothyrsus, and Zea mays. Preference test show that honeybees tend move to flowers without insecticides as the preference to insecticides A was 12.5%, insecticides B was 0%, and insecticides was C 4.2%. Mortality test showed that insecticides A has LD50 value 0.01 μg/μl, insecticide B 0.31 μg/μl, and insecticides C 0.09 μg/μl which much lower than suggested dosage recommended by insecticides producer. This research conclude that the use of insecticide could lower the pollination service provide by honey bee due to low visitation rate to flowers and mortality of foraging bees.

  13. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory.

    PubMed

    Ikeda, S; Kumaki, M; Kanesue, T; Okamura, M

    2016-02-01

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  14. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory

    NASA Astrophysics Data System (ADS)

    Ikeda, S.; Kumaki, M.; Kanesue, T.; Okamura, M.

    2016-02-01

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  15. Functional response analysis of Anisops sardea (Hemiptera: Notonectidae) against Culex quinquefasciatus in laboratory condition

    PubMed Central

    Mondal, Rajendra Prasad; Ghosh, Anupam; Bandyopadhyay, Subhasis; Chandra, Goutam

    2014-01-01

    Background & objectives: Culex quinquefasciatus is the principal vector of lymphatic filariasis (LF). Application of alternative vector control methodologies are aimed at reduction of mosquito breeding sites and biting activity through the use of biological control methods. In the present study, functional response of aquatic Hemipteran backswimmer, Anisops sardea was assessed against Cx. quinquefasciatus larvae in laboratory bioassay. Methods: The functional respons of A. sardea was assessed against IIIrd instar larvae of Cx. quinquefasciatus. Respective handling times and coefficient of attack rates were determined by a non linear polynomeal regression equation. Results: The results of rates of predation in variable prey densities exhibited a ‘linear rise to plateau curve’, associated with ‘Type -II’ functional response. The logistic regression estimated a significant negative linear parameter (P1<0) which also supported the same observation. Associated ‘attack rates’ and ‘handling times’ were also calculated using the Holling Disc Equation. Interpretation & conclusions: The results of present experiments indicate that A. sardea can be used as a biocontrol agent against the larval forms of Cx. quinquefasciatus in temporarily available breeding places of mosquito with relatively clear water. However, a detailed field study has to be done to confirm these findings. PMID:25488451

  16. Effect of soil invertebrates on the formation of humic substances under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Frouz, J.; Li, X.; Brune, A.; Pizl, V.; Abakumov, E. V.

    2011-08-01

    The complete polymerization of phenols and proteins (one of the processes involved in the formation of humic substances) was explained. It was shown that fly ( Bibio marci) larvae and earthworms ( Aporrectodea caliginosa) participate in the complete polymerization of phenols and proteins. In a laboratory experiment, invertebrates participated in the degradation of organic matter and the synthesis of humic substances, which was proved in experiments with 14C-labeled phenols and proteins. The same organic substances (phenols and proteins) without the impact of invertebrates were used as the control substances. The distributions of the 14C isotope in alkaline extracts separated by solubility in acids (humic and fulvic acids) was compared to those of the control substances. The portion of the 14C isotope in the humic acids in the excrements of Bibio marci was higher than that in the control substances. The content of 14C-labeled humic substances in the excrements of the earthworm Aporrectodea caliginosa exceeded the control values only in the experiment with proteins. When clay material was added to the organic substances, the portion of the 14C isotope in the humic acids increased in both experiments with phenols and proteins. When these substrates passed through the digestive tracts of the invertebrates, the polymerization of organic substances and the inclusion of proteins and phenols into humic acids occurred.

  17. Host Selection, Growth, and Survival of Melonworm (Lepidoptera: Crambidae) on Four Cucurbit Crops Under Laboratory Conditions

    PubMed Central

    Panthi, B. R.; Seal, D. R.; Capinera, J. L.; Nuessly, G. S.; Martin, C. G.

    2016-01-01

    The melonworm, Diaphania hyalinata L. (Lepidoptera: Crambidae), is one of the most serious insect problems affecting cucurbit production. We evaluated the relative preference and suitability of yellow squash, zucchini, cucumber, and watermelon to melonworm by measuring its oviposition, larval feeding preference, survivorship, and developmental responses in the laboratory. Whole plants were used for oviposition study, whereas host leaf discs were used for all the other studies. Watermelon feeding resulted in the longest larval development period (14.3 d), greatest prepupal weights and survivals rates (92%; first instar to adult) among the four crops. However, for watermelon, adult oviposition preference (199.5 eggs/♀), egg survival (70%), and larval feeding (4.1% defoliation) were numerically or statistically lowest, and larval head capsule widths and whole-body lengths were smallest. When differences occurred among these variables, yellow squash, zucchini, and cucumber were each typically higher (or quicker to develop) than watermelon. So why do melonworm adults not prefer watermelon, or at least select it as frequently as squash and cucumber when ovipositing? The answer likely is that there might be some variation in the important chemical components among these cucurbits. We suggest that comparison of kairomones and allomones from watermelon and related cucurbits would be very useful for determining the combination resulting in the lowest risk of damage to the more susceptible cucurbits (assuming the levels can be modified without seriously affecting the crops). PMID:27400704

  18. Sediment transport dynamics in the swash zone under large-scale laboratory conditions

    NASA Astrophysics Data System (ADS)

    Ruju, Andrea; Conley, Daniel; Masselink, Gerd; Puleo, Jack

    2016-06-01

    A laboratory experiment was carried out to study sediment transport dynamics occurring in the swash zone of a coarse-sandy beach built in a large-scale wave flume. Hydro- and morpho-dynamic as well as sediment transport data were collected using sensors mounted on a scaffold rig deployed in the lower swash zone close to the moving bed. The high resolution of near-bed data permitted quantitative evaluation of suspended and sheet flow contributions to the total sediment transport. Although sheet flow sediment fluxes were higher than suspended fluxes, the vertically integrated suspended sediment load overcame the sheet flow load during uprush and it was on the same order of magnitude during backwash. The observed cumulative sediment transport was generally larger than the morphological changes occurring shoreward of the rig location implying either an underestimation of the offshore sediment transport or an overestimation of the onshore fluxes obtained from concentration and velocity profile data. Low correlations were found between net swash profile changes and runup parameters suggesting that local hydrodynamic parameters provide little or no predictability of accretion and erosion of an upper beach which is near equilibrium. The balance between erosion and deposition induced by individual swash events brought a dynamic equilibrium with small differences between the profiles measured at the start and at the end of the run.

  19. Effect of the solenoid in various conditions of the laser ion source at Brookhaven National Laboratory

    SciTech Connect

    Ikeda, S.; Kumaki, M.; Kanesue, T.; Okamura, M.

    2016-02-15

    In the laser ion source (LIS) at the Brookhaven National Laboratory (BNL), a solenoid is used to guide the laser ablation plasma and modulate the extracted beam current. Many types of ion species are guided. In some cases, the plasma plume is injected into the solenoid away from the solenoidal axis. To investigate the effects of the solenoid on the beam extracted from the plasma that has different properties, the beam current was measured in the setup of the LIS at the BNL. The beam current of Li, Al, Si, Fe, and Au increased when the magnetic field was applied. For most of the species the peak current and the total charge within a single beam pulse increased around 10 times with a magnetic field less than 100 G. In addition, for some species the rate of increase of the peak currents became smaller when the magnetic flux densities were larger than certain values depending on the species. In this case, the current waveforms were distorted. At the same magnetic field value, the field was more effective on lighter species than on heavier ones. When plasma was injected offset from the axis of the solenoid, peak current and total charge became half of those without offset. The experimental data are useful for the operation of the LIS at the BNL.

  20. Horizontal transmission of Beauveria bassiana in Anastrepha ludens (Diptera: Tephritidae) under laboratory and field cage conditions.

    PubMed

    Toledo, Jorge; Campos, Sergio E; Flores, Salvador; Liedo, Pablo; Barrera, Juan F; Villaseñior, Antonio; Montoya, Pablo

    2007-04-01

    The virulence of two products of the fungus Beauveria bassiana (LCPP and Bassianil) on adult Anastrepha ludens (Loew) (Diptera: Tephritidae) and their effect on the mating performance of infected males was evaluated in laboratory and field cage tests. The horizontal transmission capacity of the fungus during copulation or attempted copulation also was quantified using inoculated males as well as the impact of infection on female fecundity and longevity. Both fungal products were found to be highly virulent (LCPP, mortality = 98.7% at 1 x 10(8) conidia per ml, LT50 = 4.20 d, LC50 = 9.35 x 10(5) conidia per ml; Bassianil, mortality = 99.3% at 1 X 10(8) conidia per ml, LT50 = 4.04 d, LC50 = 2.69 x 10(7) conidia per ml). Mating success of inoculated males was not affected compared with the control group during the 3 d postinoculation. Horizontal transmission to females during the first day was 80.6 and 84.3% through mating and 15.4 and 21.6% through attempts to mate and contact during courtship for the LCPP and Bassianil products, respectively. The fertility of infected females was notably reduced, and longevity did not extend beyond 15 d. Our results suggest the possibility of using sterile flies as fungus vectors in sterile insect technique programs, but the potential benefits and shortcomings of this approach require further investigation.

  1. Comparison of linuron degradation in the presence of pesticide mixtures in soil under laboratory conditions.

    PubMed

    Swarcewicz, Maria; Gregorczyk, Andrzej; Sobczak, Justyna

    2013-10-01

    It is widely recognised that complex interactions occur between chemicals in mixtures. In many agricultural situations, the use of tank mixes and complex spray programs is a common practice. Insecticides, fungicides and a herbicide being applied in potato protection were used in this research. Interactions between linuron and insecticides, such as thiamethoxam or clothianidin, and fungicides, such as mancozeb or chlorothalonil, were examined in soil. The degradation rate of linuron in soil during laboratory incubation in six treatments was studied. Mixtures of linuron with mancozeb in sandy loam and clay loam soils had a significant effect on the persistence of this herbicide. For example, for the same herbicide, t 1/2 values for linuron were from 37 days in sandy loam to 44 days in clay loam. These values changed (64-67 days) when thiamethoxam and mancozeb were in soil. When mancozeb was added only, the half-life values were from 59 to 62 days, respectively. Other mixtures with chlorothalonil, thiamethoxam and clothianidin did not have any effect. In order to compare linuron degradation rates in soils, a single first-order model and expanded statistical analysis were used.

  2. Activity, aggression, and habitat use of ruffe (Gymnocephalus cernuus) and round goby (Apollonia melanostoma) under laboratory conditions

    USGS Publications Warehouse

    Savino, J.F.; Riley, S.C.; Holuszko, M.J.

    2007-01-01

    Potential negative ecological interactions between ruffe Gymnocephalus cernuus and round gobyApollonia melanostoma (formerly Neogobius melanostomus) might affect the colonization dynamics of these invasive species where they are sympatric in the Great Lakes. In order to determine the potential for ecological interactions between these species, we examined the activity, aggression, and habitat use of round gobies and ruffe in single species and mixed species laboratory experiments. Trials included conditions in which food was concentrated (in light or darkness) or scattered. Results showed that ruffe were more active than gobies, particularly when food was scattered. Activity of both species was significantly lower during darkness. Round gobies were significantly more aggressive than ruffe, and total aggression was lower in mixed species trials. Habitat use by ruffe and round gobies overlapped considerably, but we observed significant differences between species in their use of specific habitats that depended on experimental conditions. Overall, ruffe used open habitats more often than did round gobies, primarily when food was scattered. Round gobies used rocks significantly more frequently than did ruffe, but their use of rock habitat decreased during dark conditions. Ruffe were found more often in plant habitats and less often near the wall of the pool in trials during daylight with concentrated food. Activity and habitat use of ruffe and round goby did not significantly differ between single and mixed species trials. Overall, we found little evidence for negative ecological interactions between ruffe and round goby in these laboratory experiments.

  3. Similarity Solution for Combined Free-Forced Convection Past a Vertical Porous Plate in a Porous Medium with a Convective Surface Boundary Condition

    NASA Astrophysics Data System (ADS)

    Garg, P.; Purohit, G. N.; Chaudhary, R. C.

    2016-12-01

    This paper studies the mathematical implications of the two dimensional viscous steady laminar combined free-forced convective flow of an incompressible fluid over a semi infinite fixed vertical porous plate embedded in a porous medium. It is assumed that the left surface of the plate is heated by convection from a hot fluid which is at a temperature higher than the temperature of the fluid on the right surface of the vertical plate. To achieve numerical consistency for the problem under consideration, the governing non linear partial differential equations are first transformed into a system of ordinary differential equations using a similarity variable and then solved numerically under conditions admitting similarity solutions. The effects of the physical parameters of both the incompressible fluid and the vertical plate on the dimensionless velocity and temperature profiles are studied and analysed and the results are depicted both graphically and in a tabular form. Finally, algebraic expressions and the numerical values are obtained for the local skin-friction coefficient and the local Nusselt number.

  4. Visual search for real world targets under conditions of high target-background similarity: Exploring training and transfer in younger and older adults.

    PubMed

    Neider, Mark B; Boot, Walter R; Kramer, Arthur F

    2010-05-01

    Real world visual search tasks often require observers to locate a target that blends in with its surrounding environment. However, studies of the effect of target-background similarity on search processes have been relatively rare and have ignored potential age-related differences. We trained younger and older adults to search displays comprised of real world objects on either homogenous backgrounds or backgrounds that camouflaged the target. Training was followed by a transfer session in which participants searched for novel camouflaged objects. Although older adults were slower to locate the target compared to younger adults, all participants improved substantially with training. Surprisingly, camouflage-trained younger and older adults showed no performance decrements when transferred to novel camouflage displays, suggesting that observers learned age-invariant, generalizable skills relevant for searching under conditions of high target-background similarity. Camouflage training benefits at transfer for older adults appeared to be related to improvements in attentional guidance and target recognition rather than a more efficient search strategy.

  5. Influence of blood meal and mating in reproduction patterns of Triatoma brasiliensis females (Hemiptera: Reduviidae) under laboratory conditions.

    PubMed

    Daflon-Teixeira, Natália Faria; Carvalho-Costa, Filipe Aníbal; Chiang, Ralem Gary; Lima, Marli Maria

    2009-11-01

    The influence of blood meal and mating on Triatoma brasiliensis (Neiva) female fecundity, fertility, life-span and the preoviposition period were investigated under laboratory conditions. Nourishment increased fecundity, fertility and adult lifespan, whereas mating increased fecundity, fertility and decreased the preoviposition period. Females also required more than one mating to reach their full reproductive potential. Results indicate that both nourishment and mating are important in T. brasiliensis proliferation. Such information will help towards developing effective control strategies of this vector of Chagas disease.

  6. Egg-to-fry survival of two strains of Atlantic salmon (Salmo salar) in stream incubators under laboratory conditions

    USGS Publications Warehouse

    Johnson, James H.

    2003-01-01

    Egg-to-fry survival of two strains of Atlantic salmon (Salmo salar) was evaluated under laboratory conditions in two commercial stream egg incubators. The survival was also examined based on egg developmental stage (i.e., green eggs, eyed egggs, advanced eggs). There was no significant difference in survival of eggs in the Jordan-Scotty and Whitlock-Vibert incubators. However, the survival of Sebago strain Atlantic slamon eggs was significantly higher than that of Penobscot stream eggs, and survival increased with advanced egg developmental stage.

  7. A Comparison of the Availability and Failure Modes of the BaBar Superconducting Solenoid with Similar Magnets at Other High Energy Physics Laboratories

    SciTech Connect

    Knodel, Mallory

    2003-09-05

    One of the key technologies in the BaBar detector is the 1.5 T superconducting solenoid. It is imperative that this device operate reliably at its nominal current to allow data taking. While this system is available for physics 98.8% of the time, further improvements are desirable. The object of this project is to survey similar magnet systems, for example those at KEK (Belle), Fermilab (D0 and CDF), DESY (H1 and ZEUS), and CERN (ALEPH and DELPHI), to see how often such magnets stop functioning properly and what the root causes of the failures are. A survey was carried out via e-mail and telephone calls. Information was obtained regarding the operation of superconducting magnets, specifically the BaBar magnet and its ancillary systems, as well as an overview of the use of other such magnets both in the US and overseas. In this work, failure modes will be investigated and compared to the BaBar operational experience. Future investigations can now assess the feasibility of reducing the time the BaBar magnet is nonoperational and unavailable for physics research.

  8. Evaluation of the Ott Hydromet Qliner for measuring discharge in laboratory and field conditions

    USGS Publications Warehouse

    McVay, Jason C.

    2015-01-01

    The U.S. Geological Survey, in collaboration with the University of Iowa IIHR – Hydroscience and Engineering, evaluated the use of the Ott Hydromet Qliner using laboratory flume tests along with field validation tests. Analysis of the flume testing indicates the velocities measured by the Qliner at a 40-second exposure time results in higher dispersion of velocities from the mean velocity of data collected with a 5-minute exposure time. The percent data spread from the mean of a 100-minute mean of Qliner velocities for a 40-second exposure time averaged 16.6 percent for the entire vertical, and a 5-minute mean produced a 6.2 percent data spread from the 100-minute mean. This 16.6 percent variation in measured velocity would result in a 3.32 percent variation in computed discharge assuming 25 verticals while averaging 4 bins in each vertical. The flume testing also provided results that indicate the blanking distance of 0.20 meters is acceptable when using beams 1 and 2, however beam 3 is negatively biased near the transducer and the 0.20-meter blanking distance is not sufficient. Field testing included comparing the measured discharge by the Qliner to the discharge measured by a Price AA mechanical current meter and a Teledyne RDI Rio Grande 1200 kilohertz acoustic Doppler current profiler. The field tests indicated a difference between the discharges measured with the Qliner and the field reference discharge between -14.0 and 8.0 percent; however the average percent difference for all 22 field comparisons was 0.22, which was not statistically significant.

  9. Hydrologic conditions at the Idaho National Engineering Laboratory, 1982 to 1985

    USGS Publications Warehouse

    Pittman, J.R.; Fischer, P.R.; Jensen, R.G.

    1988-01-01

    Aqueous chemical and radioactive wastes discharged since 1952 to unlined ponds and wells at the INEL (Idaho National Engineering Laboratory) have affected water quality in perched groundwater zones and in the Snake River Plain Aquifer. Routine waste water disposal was changed from deep injection wells to ponds at the ICPP (Idaho Chemical Processing Plant) in 1984. During 1982-85, tritium concentrations increased in perched groundwater zones under disposal ponds, but cobalt-60 concentrations decreased. In 1985, perched groundwater under TRA disposal ponds contained up to 1,770 +or-30 pCi/mL (picocuries/milliliter) of tritium and 0.36+or-0.05 pCi/mL of cobalt-60. During 1982-85, tritium concentrations in water in the Snake River Plain aquifer decreased as much as 80 pCi/mL near the ICPP. In 1985, measurable tritium concentrations ranged from 0.9+or-0.3 to 93.4 +or-2.0 pCi/mL. Tritium was detected in groundwater near the southern boundary of the INEL, 9 miles south of the ICPP and TRA. Strontium-90 concentrations in groundwater, up to 63 +or-5 pCi/L (picocuries per liter) near the ICPP, generally were smaller than 1981 concentrations. Cesium-137 concentrations in groundwater near the ICPP ranged from 125 +or-14 to 237 +or-45 pCi/L. Maximum concentrations of plutonium-238 and plutonium-239 , -240 (undivided) were 1.31 +or-.0019 pCi/ml and 1.9 +or-0.00003 pCi/L. Sodium and chloride generally decreased during 1982-85. Nitrate concentrations increased near the TRA and NRF (Naval Reactors Facility) and decreased near the ICPP. (USGS)

  10. Developmental and reproductive patterns of Triatoma brasiliensis infected with Trypanosoma cruzi under laboratory conditions.

    PubMed

    Oliveira, Tiago G; Carvalho-Costa, Filipe A; Gomes, Taís F; Sarquis, Otília; Sposina, Ricardo; Lima, Marli M

    2010-12-01

    The aim of this work was to study the interaction between Trypanosoma cruzi-1 and Triatoma brasiliensis. A group of 1st instar nymphs was initially fed on T. cruzi-infected mice and a control group was fed on uninfected mice. From the second feeding onwards, both groups were otherwise fed on non-infected mice. The resulting adults were grouped in pairs: infected male/uninfected female, uninfected male/infected female, infected male and female and uninfected male/uninfected female. The infection affected only the 1st instar nymphs, which took significantly more time to reach the 2nd instar than uninfected nymphs. The differences in the molting time between the infected and uninfected nymphs from the 2nd to the 5th instars were not statistically significant. Both groups presented similar rates of nymphal mortality and reproductive performance was not significantly affected by infection in any of the treatments.

  11. The importance of environmental conditions in reflectance spectroscopy of laboratory analogs for Mars surface materials

    NASA Technical Reports Server (NTRS)

    Bishop, J.; Murchie, S.; Pratt, S.; Mustard, J.; Pieters, C.

    1993-01-01

    Reflectance spectra are presented here for a variety of particulate, ferric-containing analogs to Martian soil (Fe(3+)-doped smectites and palagonites) to facilitate interpretation of remotely acquired spectra. The analog spectra were measured under differing environmental conditions to evaluate the influence of exposure history on water content and absorption features due to H2O in these samples. Each of these materials contains structural OH bonded to metal cations, adsorbed H2O, and bound H2O (either in a glass, structural site, or bound to a cation). Previous experiments involving a variety of Mars analogs have shown that the 3 micron H2O band in spectra of palagonites is more resistant to drying than the 3 micron H2O band in spectra of montmorillonites. Other experiments have shown that spectra of ferrihydrite and montmorillonites doped with ferric sulfate also contain sufficient bound H2O to retain a strong 3 micron band under dry conditions. Once the effects of the environment on bound water in clays, oxides, and salts are better understood, the hydration bands measured via reflectance spectroscopy can be used to gain information about the chemical composition and moisture content of real soil systems. Such information would be especially useful in interpreting observations of Mars where subtle spatial variations in the strengths of metal-OH and H2O absorptions have been observed in telescopic and ISM spectra. We measured bidirectional reflectance spectra of several Mars soil analogs under controlled environmental conditions to assess the effects of moisture content on the metal-OH and H2O absorptions. The samples analyzed include chemically altered montmorillonites, ferrihydrite. and palagonites from Hawaii and Iceland. Procedures for preparation of the cation-exchanged montmorillonites, ferric-salt doped montmorillonites, and ferric oxyhydroxides are described in detail elsewhere.

  12. Evaluation of Geochemical Fracture Conductivity Alterations in Shale under Laboratory Conditions

    NASA Astrophysics Data System (ADS)

    Radonjic, M.; Olabode, A.

    2015-12-01

    In large scale subsurface injection of carbondioxide as obtainable in carbon sequestration programs and in environmentally friendly hydraulic fracturing processes (using supercritical CO2), rock-fluid interaction can affect reservoir and seal rocks properties which are essential in monitoring the progress of these operations. The mineralogical components of sedimentary rocks are geochemically active particularly under enormous earth stresses. While geomechanical properties such as rock stiffness, Poisson's ratio and fracture geometry largely govern fluid flow characteristics in deep fractured formations, the effect of mineralization can lead to flow impedance in the presence of favorable geochemical and thermodynamic conditions. Experimental works which employed the use of analytical tools such as ICP-OES, XRD, SEM/EDS, TOC and BET techniques in investigating diagenetic and micro-structural properties of crushed shale caprock/CO2-brine system concluded that net precipitation reaction processes can affect the distribution of petrophysical nanopores in the shale as a result of rock-fluid interactions. Simulation results previously reported, suggest that influx-induced mineral dissolution/precipitation reactions within clay-based sedimentary rocks can continuously close micro-fracture networks, though injection pressure and effective-stress transformation first rapidly expand these fractures. This experimental modelling research investigated the impact of in-situ geochemical precipitation on conductivity of fractures under geomechanical stress conditions. Conductivity is measured as differential-pressure drop equivalence, using a pressure pulse-decay liquid permeametry/core flooding system, as geochemically saturated-fluid is transported through composite cores with embedded micro-tubings that mimic fractures. The reactive fluid is generated from crushed shale rocks of known mineralogical composition when flooded with aqueous CO2 at elevated temperature and pressure

  13. The inheritance of female colour polymorphism in Ischnura genei (Zygoptera: Coenagrionidae), with observations on melanism under laboratory conditions

    PubMed Central

    Cordero-Rivera, Adolfo

    2016-01-01

    Current research on female colour polymorphism in Ischnura damselflies suggests that a balanced fitness trade-off between morphotypes contributes to the maintenance of polymorphism inside populations. The genetic inheritance system constitutes a key factor to understand morph fluctuation and fitness. Ischnura genei, an endemic species of some Mediterranean islands, has three female colour morphs, including one androchrome (male-coloured) and two gynochromes. In this study, we reared two generations of I. genei under laboratory conditions and tested male behavioural responses to female colour morphs in the field. We recorded ontogenetic colour changes and studied morph frequency in three populations from Sardinia (Italy). Morph frequencies of laboratory crosses can be explained by a model based on an autosomal locus with three alleles and sex-restricted expression, except for one crossing of 42 families with unexpected offspring. The allelic dominance relationship was androchrome > infuscans > aurantiaca. Old individuals reared in the laboratory exhibited different levels of melanism in variable extent depending on sex and morph. Results of model presentations indicate a male preference for gynochrome females and the lack of recognition of androchromes as potential mates. Aurantiaca females were the most frequent morph in the field (63–87%). Further studies in other populations and islands are needed to understand the maintenance of this polymorphism. PMID:27635344

  14. The inheritance of female colour polymorphism in Ischnura genei (Zygoptera: Coenagrionidae), with observations on melanism under laboratory conditions.

    PubMed

    Sanmartín-Villar, Iago; Cordero-Rivera, Adolfo

    2016-01-01

    Current research on female colour polymorphism in Ischnura damselflies suggests that a balanced fitness trade-off between morphotypes contributes to the maintenance of polymorphism inside populations. The genetic inheritance system constitutes a key factor to understand morph fluctuation and fitness. Ischnura genei, an endemic species of some Mediterranean islands, has three female colour morphs, including one androchrome (male-coloured) and two gynochromes. In this study, we reared two generations of I. genei under laboratory conditions and tested male behavioural responses to female colour morphs in the field. We recorded ontogenetic colour changes and studied morph frequency in three populations from Sardinia (Italy). Morph frequencies of laboratory crosses can be explained by a model based on an autosomal locus with three alleles and sex-restricted expression, except for one crossing of 42 families with unexpected offspring. The allelic dominance relationship was androchrome > infuscans > aurantiaca. Old individuals reared in the laboratory exhibited different levels of melanism in variable extent depending on sex and morph. Results of model presentations indicate a male preference for gynochrome females and the lack of recognition of androchromes as potential mates. Aurantiaca females were the most frequent morph in the field (63-87%). Further studies in other populations and islands are needed to understand the maintenance of this polymorphism.

  15. The Rearing and Biology of the Desert Beetle, Microdera punctipennis, Under Laboratory Conditions

    PubMed Central

    Wang, Yan; Liu, Xiaoning; Zhao, Jia; Rexili, Kelaimu; Ma, Ji

    2011-01-01

    Microdera punctipennis Kasz (Coleoptera: Tenebrionidae) is a unique species that lives in the desert region of Central Asia and has adopted a nocturnal habit to survive the desert environment. Female adults are larger in size than male adults. The female/male ratio was 1.04:1. A rearing method using reused plastic bottles was used. The rearing conditions were 30 ± 0.5°C, 30 ± 6% relative humidity (RH), and 16:8 L:D photoperiod. Cabbage was provided as food. Cannibalism was avoided by rearing one larva in a bottle. A complete life cycle was obtained under these conditions. The viability of eggs, larvae, prepupae, pupae, and teneral adults was 93.54%, 83.71%, 84.76%, 87.64%, and 93.59%, respectively. Embryogenesis took 7.35 days on average. The larval duration in each instar was 2.25 days. The mean duration of the larvae, prepupae, pupae, and teneral adult was 49.27, 7.05, 9.95, and 10.12 days, respectively. The coloration of each developmental stage gradually changed from creamy white to light brownish or black. Females commenced oviposition when their body color became black. On average, each female produced 568 eggs. PMID:21529250

  16. Daily rhythms of physiological parameters in the dromedary camel under natural and laboratory conditions.

    PubMed

    Al-Haidary, Ahmed A; Abdoun, Khalid A; Samara, Emad M; Okab, Aly B; Sani, Mamane; Refinetti, Roberto

    2016-08-01

    Camels are well adapted to hot arid environments and can contribute significantly to the economy of developing countries in arid regions of the world. Full understanding of the physiology of camels requires understanding of the internal temporal order of the body, as reflected in daily or circadian rhythms. In the current study, we investigated the daily rhythmicity of 20 physiological variables in camels exposed to natural oscillations of ambient temperature in a desert environment and compared the daily temporal courses of the variables. We also studied the rhythm of core body temperature under experimental conditions with constant ambient temperature in the presence and absence of a light-dark cycle. The obtained results indicated that different physiological variables exhibit different degrees of daily rhythmicity and reach their daily peaks at different times of the day, starting with plasma cholesterol, which peaks 24min after midnight, and ending with plasma calcium, which peaks 3h before midnight. Furthermore, the rhythm of core body temperature persisted in the absence of environmental rhythmicity, thus confirming its endogenous nature. The observed delay in the acrophase of core body temperature rhythm under constant conditions suggests that the circadian period is longer than 24h. Further studies with more refined experimental manipulation of different variables are needed to fully elucidate the causal network of circadian rhythms in dromedary camels.

  17. Molecular response of Saccharomyces cerevisiae wine and laboratory strains to high sugar stress conditions.

    PubMed

    Jiménez-Martí, E; Zuzuarregui, A; Gomar-Alba, M; Gutiérrez, D; Gil, C; del Olmo, M

    2011-01-31

    One of the stress conditions that can affect Saccharomyces cerevisiae cells during their growth is osmotic stress. Under particular environments (for instance, during the production of alcoholic beverages) yeasts have to cope with osmotic stress caused by high sugar concentrations. Although the molecular changes and pathways involved in the response to saline or sorbitol stress are widely understood, less is known about how cells respond to high sugar concentrations. In this work we present a comprehensive study of the response to this form of stress which indicates important transcriptomic changes, especially in terms of the genes involved in both stress response and respiration, and the implication of the HOG pathway. We also describe several genes of an unknown function which are more highly expressed under 20% (w/v) glucose than under 2% (w/v) glucose. In this work we focus on the YHR087w (RTC3) gene and its encoded protein. Proteomic analysis of the mutant deletion strain reveals lower levels of several yeast Hsp proteins, which establishes a link between this protein and the response to several forms of stress. The relevance of YHR087W for the response to high sugar and other stress conditions and the relationship of the encoded protein with several Hsp proteins suggest applications of this gene in biotechnological processes in which response to stress is important.

  18. Clinicopathological differences exist between CALR- and JAK2-mutated myeloproliferative neoplasms despite a similar molecular landscape: data from targeted next-generation sequencing in the diagnostic laboratory.

    PubMed

    Agarwal, Rishu; Blombery, Piers; McBean, Michelle; Jones, Kate; Fellowes, Andrew; Doig, Ken; Forsyth, Cecily; Westerman, David A

    2017-02-04

    Mutations in CALR have recently been detected in JAK2-negative myeloproliferative neoplasms (MPNs) and are key pathological drivers in these diseases. CALR-mutated MPNs are shown to have numerous clinicopathological differences to JAK2-mutated MPNs. The basis of these differences is poorly understood. It is unknown whether these differences result directly from any differences in intracellular signalling abnormalities induced by JAK2/CALR mutations or whether they relate to other phenomena such as a differing spectrum of genetic lesions between the two groups. We aimed to review the clinicopathological and molecular features of CALR- and JAK2-mutated MPNs from samples referred for diagnostic testing using a custom-designed targeted next-generation sequencing (NGS) panel. Eighty-nine CALR-mutated cases were compared with 70 JAK2-mutated cases. CALR-mutated MPNs showed higher platelet counts and a female predominance as compared to JAK2-mutated MPNs in our cohort. We have also observed differences between CALR mutation subtypes in terms of disease phenotype, mutational frequency and allelic burden. Type 1 CALR mutations were found to be more common in myelofibrosis, associated with a higher frequency and number of additional mutations and a higher mutant allelic burden as compared to type 2 CALR mutations. Despite these biological differences, our molecular characterisation suggests that CALR- and JAK2-mutated MPNs are broadly similar in terms of the quantity, frequency and spectrum of co-occurring mutations and therefore observed biological differences are likely to not be heavily influenced by the nature and quantity of co-mutated genes.

  19. Similar Survival for Patients Undergoing Reduced-Intensity Total Body Irradiation (TBI) Versus Myeloablative TBI as Conditioning for Allogeneic Transplant in Acute Leukemia

    SciTech Connect

    Mikell, John L.; Waller, Edmund K.; Switchenko, Jeffrey M.; Rangaraju, Sravanti; Ali, Zahir; Graiser, Michael; Hall, William A.; Langston, Amelia A.; Esiashvili, Natia; Khoury, H. Jean; Khan, Mohammad K.

    2014-06-01

    Purpose: Hematopoietic stem cell transplantation (HSCT) is the mainstay of treatment for adults with acute leukemia. Total body irradiation (TBI) remains an important part of the conditioning regimen for HCST. For those patients unable to tolerate myeloablative TBI (mTBI), reduced intensity TBI (riTBI) is commonly used. In this study we compared outcomes of patients undergoing mTBI with those of patients undergoing riTBI in our institution. Methods and Materials: We performed a retrospective review of all patients with acute leukemia who underwent TBI-based conditioning, using a prospectively acquired database of HSCT patients treated at our institution. Patient data including details of the transplantation procedure, disease status, Karnofsky performance status (KPS), response rates, toxicity, survival time, and time to progression were extracted. Patient outcomes for various radiation therapy regimens were examined. Descriptive statistical analysis was performed. Results: Between June 1985 and July 2012, 226 patients with acute leukemia underwent TBI as conditioning for HSCT. Of those patients, 180 had full radiation therapy data available; 83 had acute lymphoblastic leukemia and 94 had acute myelogenous leukemia; 45 patients received riTBI, and 135 received mTBI. Median overall survival (OS) was 13.7 months. Median relapse-free survival (RFS) for all patients was 10.2 months. Controlling for age, sex, KPS, disease status, and diagnosis, there were no significant differences in OS or RFS between patients who underwent riTBI and those who underwent mTBI (P=.402, P=.499, respectively). Median length of hospital stay was shorter for patients who received riTBI than for those who received mTBI (16 days vs 23 days, respectively; P<.001), and intensive care unit admissions were less frequent following riTBI than mTBI (2.22% vs 12.69%, respectively, P=.043). Nonrelapse survival rates were also similar (P=.186). Conclusions: No differences in OS or RFS were seen between

  20. Effectiveness of biological geotextiles in reducing runoff and soil loss under different environmental conditions using laboratory and field plot data

    NASA Astrophysics Data System (ADS)

    Smets, T.

    2009-04-01

    Preliminary investigations suggest biological geotextiles could be an effective and inexpensive soil conservation method, with enormous global potential. Biological geotextiles are a possible temporary alternative for vegetation cover and can offer immediate soil protection. However, limited data are available on the erosion-reducing effects of biological geotextiles. Therefore, the objective of this study is to evaluate the effectiveness of selected types of biological geotextile in reducing runoff and soil loss under controlled laboratory conditions and under field conditions reflecting different environments (i.e. continental, temperate and tropical). In laboratory experiments, interrill runoff, interrill erosion and concentrated flow erosion were simulated using various rainfall intensities, flow shear stresses and slope gradients. Field plot data on the effects of biological geotextiles on sheet and rill erosion were collected in several countries under natural rainfall (U.K., Hungary, Lithuania, South Africa, Brazil, China and Thailand). The laboratory experiments indicate that all tested biological geotextiles were effective in reducing interrill runoff (on average 59% of the value for bare soil) and interrill erosion rates (on average 16% of the value for bare soil). Since simulated concentrated flow discharge sometimes flowed below the geotextiles, the effectiveness in reducing concentrated flow erosion was significantly less (on average 59% of the value for bare soil). On field plots, where both interrill and rill erosion occur, all tested geotextiles reduced runoff depth by a mean of 54% of the control value for bare soil and in some cases, runoff depth increased compared to bare soil surfaces, which can be attributed to the impermeable and hydrophobic characteristics of some biological geotextiles. In the field, soil loss rates due to interrill and rill erosion were reduced by a mean of 21% of the value of bare soil by biological geotextiles. This study

  1. Laboratory studies in planetary science and quantitative analysis of evaporation rates under current Martian conditions

    NASA Astrophysics Data System (ADS)

    Moore, Shauntae

    2005-12-01

    Laboratory measurements have been performed that are intended to shed light on several problems in planetary science. Thermoluminescence measurements of ordinary chondrites have been performed as part of an effort to identify the most primitive materials in the solar system. Experiments to study the fractionation of metal and silicate grains on asteroid surfaces have been performed on NASA's microgravity facility because of its relevance to meteorite origins and the exploration of asteroids by robotic spacecraft. The results of these studies are presented in this thesis as a conference presentation whose summary appeared in the journal Meteoritics and Planetary Science and a paper that appeared in the journal Geophysical Research Letters. The rest of the thesis describes measurements on the stability of water on the surface of Mars and is submitted in normal thesis format, although at the time of submission some of this work has appeared in Geophysical Research Letters and some has been submitted to the journal Astrobiology. The thermoluminescence studies were used to derive petrologic classifications for several type 3 ordinary chondrites from North Africa, some of which are very low and have the potential to provide new insights to the early solar system and its formation. The metal-silicate fractionation work suggests that the differences in composition observed among the major chondrite groups, the H, L and LL chondrites, could be the result of processes occurring on the surface of the meteorite parent body, probably an asteroid. They also suggest that minor disturbances of the surface will cause separation of components in the asteroid regolith and this should be borne in mind in robotics exploration of asteroids. The stability of water on Mars was investigated by measuring the evaporation rate of liquid water in a Mars-like environment produced in a large chamber on Earth. The evaporation rates measured are in good agreement with model-dependent theoretical

  2. Laboratory simulations of the interaction between ozone and chloroacetic acids in the conditions close to stratospheric

    NASA Astrophysics Data System (ADS)

    Strokova, N. E.; Savilov, S. V.; Morozov, I. I.; Yagodovskaya, T. V.; Lunin, V. V.

    2015-01-01

    The interaction between ozone and mono-, di-, and trichloroacetic acids are studied using a flow vacuum gas discharge setup in a regime close to stratospheric conditions (in the temperature range of 77 to 250 K, at pressures of 10-3 to 0 Torr, and in the presence of ice). The interaction between ozone and trichloroacetic acid starts at 77 K, while interaction with monochloroacetic acid begins when the temperature is raised to 200 K. The reactions are assumed to proceed via different mechanisms: chlorine oxides of different composition are the reaction products, as is shown using low-temperature IR spectroscopy. Preliminary adsorption of the acids on a surface of ice raises the temperature of interaction to 190 K.

  3. Insights into the formation mechanism of chloropropanol fatty acid esters under laboratory-scale deodorization conditions.

    PubMed

    Hori, Katsuhito; Hori-Koriyama, Natsuko; Tsumura, Kazunobu; Fukusaki, Eiichiro; Bamba, Takeshi

    2016-08-01

    Chloropropanol fatty acid esters (CPFAEs) are well-known contaminants in refined oils and fats, and several research groups have studied their formation. However, the results obtained in these studies were not satisfactory because the CPFAEs were not analyzed comprehensively. Thus, in the present study, a comprehensive analysis was performed to obtain new details about CPFAE formation. Each lipid (monopalmitin, dipalmitin, tripalmitin, monoolein, diolein, triolein, and crude palm oil) was heated at 250°C for 90 min, and the CPFAEs were analyzed using supercritical fluid chromatography/tandem mass spectrometry. It was found that CP fatty acid monoesters were formed from monoacylglycerols and diacylglycerols after heating in the presence of a chlorine compound. In addition, CP fatty acid diesters were formed from diacylglycerols and triacylglycerols under the same conditions. In the case of crude palm oil, only CP fatty acid diesters were formed. Therefore, these results indicated that CPFAEs in refined palm oil were formed mainly from triacylglycerols.

  4. Vegetation-derived cues for the selection of oviposition substrates by Anopheles albimanus under laboratory conditions.

    PubMed

    Torres-Estrada, José Luis; Meza-Alvarez, R Amanda; Cibrián-Tovar, Juan; Rodríguez-López, Mario H; Arredondo-Jiménez, Juan I; Cruz-López, Leopoldo; Rojas-Leon, Julio C

    2005-12-01

    Oviposition response of gravid Anopheles albimanus Wiedemman (Diptera: Culicidae) females to water containing Brachiaria mutica, Cynodon dactylon, Jouvea straminea, Fimbristylis spadicea, and Ceratophyllum demersum was investigated. Gravid An. albimanus females deposited similar egg numbers in cups containing natural plants in water from natural breeding sites and in cups containing natural plants in distilled water. Gravid mosquitoes deposited significantly more eggs in cups containing natural plants in water from natural breeding sites than in cups containing artificial plants in water from the corresponding natural breeding sites. These results were confirmed in experiments conducted in a wind tunnel, indicating that female response is mediated by chemical cues from plants. Bioassays with organic extracts of all 5 plant species indicated that these extracts at 100%, 10%, and 1% concentrations had an oviposition repellent effect, while attractiveness was observed at 0.1%, 0.01%, and 0.001%. Gas chromatography and mass spectrometry analysis of the organic extracts found in all 5 plants showed a mixture of terpenoid and alcohol compounds, among them: guaiacol, phenol, isoeugenol, longifolene, caryophyllene, phenyl ethyl alcohol, and p-cresol. These results suggest that middle-range volatiles from plants may function as chemical cues for the female's oviposition response in this mosquito species.

  5. Factors affecting growth and survival of the asiatic clam Corbicula sp. under controlled laboratory conditions

    SciTech Connect

    Double, D.D.; Daly, D.S.; Abernethy, C.S.

    1983-04-01

    Growth of Corbicula sp. was determined in relation to food supply, water temperature, and clam size as an aid to researchers conducting chronic effects toxicity studies. Water temperatures for the two 84-day test series were 10, 20, and 30/sup 0/C. Linear models provided good relationships (r/sup 2/ > 0.90) between clam shell length (SL), total weight (TW), and wet/dry tissue weights. Clam growth was minimal during low phytoplankton densities (approx. 300 cells/ml), and all three size groups lost weight at 20 and 30/sup 0/C. Mortality of small clams at 30/sup 0/C was 100% after 71 days. At phytoplankton densities > 1000 cells/ml, overall differences in growth with respect to clam size and temperature were detectable at p < 0.01; growth of all clam groups was greatest at 30/sup 0/C. Small clams exhibited the greatest absolute increase in mean shell length at all test temperatures, and weight gains were similar to those of medium and large clams.

  6. Accumulation and Elimination of Enrofloxacin and Ciprofloxacin in Tissues of Shrimp Litopenaeus vannamei under Laboratory and Farm Conditions

    PubMed Central

    Flores-Miranda, Brisa Marisol; Espinosa-Plascencia, Angelica; Gómez-Jiménez, Silvia; López-Zavala, Alonso Alexis; González-Carrillo, Haydé Hayamaí; Bermúdez-Almada, María del Carmen

    2012-01-01

    This study aimed to quantify the accumulation and elimination of Enrofloxacin (ENRO) and Ciprofloxacin (CIPRO) in cultivated Litopenaeus vannamei under controlled laboratory and farm conditions. Laboratory- and farm-raised shrimp were given feed supplemented with 200 mg/kg ENRO for 14 days, followed by a 16-day diet without antibiotics. The levels of ENRO and CIPRO were analyzed by High Performance Liquid Chromatography (HPLC). In the laboratory, ENRO concentrations in the muscle and hepatopancreas reached a maximum (Cmax) of 0.54 ± 0.26 μg/g and 3.52 ± 1.9 μg/g, respectively; Cmax values for CIPRO in the laboratory were 0.18 ± 0.13 μg/g (muscle) and 1.05 ± 0.20 μg/g (hepatopancreas). In farmed shrimp, Cmax values for ENRO were 0.36 ± 0.17 μg/g muscle and 1.60 ± 0.82 μg/g in the hepatopancreas; CIPRO Cmax values were 0.03 ± 0.02 μg/g (muscle) and 0.36 ± 0.08 μg/g (hepatopancreas). Two to fourteen days were necessary to eliminate both antibiotics from muscular tissue and four to more fourteen days for complete elimination of the antibiotics from the hepatopancreas. These results should be considered in terms of minimum concentrations necessary to inhibit Vibrio bacteria to determine whether the current use of this antibiotic is effective in controlling disease. PMID:22779008

  7. Accumulation and Elimination of Enrofloxacin and Ciprofloxacin in Tissues of Shrimp Litopenaeus vannamei under Laboratory and Farm Conditions.

    PubMed

    Flores-Miranda, Brisa Marisol; Espinosa-Plascencia, Angelica; Gómez-Jiménez, Silvia; López-Zavala, Alonso Alexis; González-Carrillo, Haydé Hayamaí; Bermúdez-Almada, María Del Carmen

    2012-01-01

    This study aimed to quantify the accumulation and elimination of Enrofloxacin (ENRO) and Ciprofloxacin (CIPRO) in cultivated Litopenaeus vannamei under controlled laboratory and farm conditions. Laboratory- and farm-raised shrimp were given feed supplemented with 200 mg/kg ENRO for 14 days, followed by a 16-day diet without antibiotics. The levels of ENRO and CIPRO were analyzed by High Performance Liquid Chromatography (HPLC). In the laboratory, ENRO concentrations in the muscle and hepatopancreas reached a maximum (C(max)) of 0.54 ± 0.26 μg/g and 3.52 ± 1.9 μg/g, respectively; C(max) values for CIPRO in the laboratory were 0.18 ± 0.13 μg/g (muscle) and 1.05 ± 0.20 μg/g (hepatopancreas). In farmed shrimp, C(max) values for ENRO were 0.36 ± 0.17 μg/g muscle and 1.60 ± 0.82 μg/g in the hepatopancreas; CIPRO C(max) values were 0.03 ± 0.02 μg/g (muscle) and 0.36 ± 0.08 μg/g (hepatopancreas). Two to fourteen days were necessary to eliminate both antibiotics from muscular tissue and four to more fourteen days for complete elimination of the antibiotics from the hepatopancreas. These results should be considered in terms of minimum concentrations necessary to inhibit Vibrio bacteria to determine whether the current use of this antibiotic is effective in controlling disease.

  8. Behaviour of laboratory mice in different housing conditions when allowed to self-administer an anxiolytic.

    PubMed

    Olsson, I Anna S; Sherwin, Chris M

    2006-10-01

    Standard cages prevent mice from performing several natural behaviours for which they are motivated. As a consequence, abnormal behaviours sometimes develop and mice often spend long periods inactive. To improve welfare, cages are sometimes furnished with items such as nesting material, shelters and running wheels. We have previously reported that when allowed to self-administer an anxiolytic, mice in furnished cages consume less anxiolytic than mice in standard cages. This paper presents the results of behaviour studies of the mice in the same experiment. Female C57BL/6J mice (3 per cage) were housed in Standard (n = 10), Unpredictable (n = 10) or Furnished (n = 6) cages. Unpredictable cages were identical to Standard cages, but were exposed to unpredictable events two to three times a week. Furnished cages were double the size of Standard cages and contained nesting material, nest box, tubes, chew blocks and a running wheel. During three consecutive periods, mice had access to only water (control), water or an anxiolytic solution on a daily alternating schedule (forced consumption), and finally, both water and anxiolytic (self-administration). Behaviour was analysed from video recordings taken during the dark phase. The housing type affected behaviour both under the control and the self-administration conditions. Overall, mice in Furnished cages spent less time resting and performing bar-related behaviours and more time on exploratory/locomotory behaviours. Mice in Furnished cages also performed less bar-circling stereotypies than mice in Standard cages. The Unpredictable treatment did not significantly affect behaviour compared to mice in the Standard conditions. There was an overall effect of anxiolytic availability on rest-related behaviours and on exploration-locomotion behaviours, in that mice rested more and spent less time on exploration and locomotion when they were able to self-administer the anxiolytic.

  9. Staphylococcus aureus Transcriptome Architecture: From Laboratory to Infection-Mimicking Conditions

    PubMed Central

    Depke, Maren; Pané-Farré, Jan; Debarbouille, Michel; van der Kooi-Pol, Magdalena M.; Guérin, Cyprien; Dérozier, Sandra; Hiron, Aurelia; Jarmer, Hanne; Leduc, Aurélie; Michalik, Stephan; Reilman, Ewoud; Schaffer, Marc; Schmidt, Frank; Bessières, Philippe; Noirot, Philippe; Hecker, Michael; Msadek, Tarek; Völker, Uwe; van Dijl, Jan Maarten

    2016-01-01

    Staphylococcus aureus is a major pathogen that colonizes about 20% of the human population. Intriguingly, this Gram-positive bacterium can survive and thrive under a wide range of different conditions, both inside and outside the human body. Here, we investigated the transcriptional adaptation of S. aureus HG001, a derivative of strain NCTC 8325, across experimental conditions ranging from optimal growth in vitro to intracellular growth in host cells. These data establish an extensive repertoire of transcription units and non-coding RNAs, a classification of 1412 promoters according to their dependence on the RNA polymerase sigma factors SigA or SigB, and allow identification of new potential targets for several known transcription factors. In particular, this study revealed a relatively low abundance of antisense RNAs in S. aureus, where they overlap only 6% of the coding genes, and only 19 antisense RNAs not co-transcribed with other genes were found. Promoter analysis and comparison with Bacillus subtilis links the small number of antisense RNAs to a less profound impact of alternative sigma factors in S. aureus. Furthermore, we revealed that Rho-dependent transcription termination suppresses pervasive antisense transcription, presumably originating from abundant spurious transcription initiation in this A+T-rich genome, which would otherwise affect expression of the overlapped genes. In summary, our study provides genome-wide information on transcriptional regulation and non-coding RNAs in S. aureus as well as new insights into the biological function of Rho and the implications of spurious transcription in bacteria. PMID:27035918

  10. Copper-binding proteins in liver of bluegills exposed to increased soluble copper under field and laboratory conditions.

    PubMed Central

    Harrison, F L; Lam, J R

    1986-01-01

    Livers from bluegills exposed to increased soluble copper (Cu) under field and laboratory conditions were analyzed to determine the concentration and distribution of Cu in metalloproteins of different molecular size. Analyses were performed on bluegills collected from the impoundment of the H. B. Robinson Steam Electric Plant (Florence, SC) near the effluent discharge from the power plant, near the water intake to the cooling system, and from a control pond as well as on bluegills exposed under controlled laboratory conditions. Metalloproteins were separated into low molecular weight (LMW), intermediate molecular weight (IMW), and high molecular weight (HMW) fractions by using high-performance liquid chromatography. In the field-exposed bluegills, Cu concentrations in the LMW, IMW, and HMW fractions were highest in bluegills from the discharge site and lowest in those from the control pond. In the laboratory-exposed bluegills, Cu concentrations in the fractions increased with exposure concentration and time. Concentrations of Cu in the LMW protein fraction and pellet of bluegills exposed to 160 micrograms Cu/L appeared to plateau with long exposure times, whereas those in the HMW fraction continued to increase. Bluegills maintained in 80 micrograms Cu/L water at pH 5.5 accumulated lower concentrations of Cu in the LMW and pellet fractions and higher amounts in the HMW than in those maintained in 80 micrograms Cu/L at pH 7.0. Mortality was dependent on exposure concentration and duration and was higher in bluegills maintained in water at pH 5.5 than at pH 7.0. PMID:3709431

  11. Lack of glyphosate resistance gene transfer from Roundup Ready soybean to Bradyrhizobium japonicum under field and laboratory conditions.

    PubMed

    Isaza, Laura Arango; Opelt, Katja; Wagner, Tobias; Mattes, Elke; Bieber, Evi; Hatley, Elwood O; Roth, Greg; Sanjuán, Juan; Fischer, Hans-Martin; Sandermann, Heinrich; Hartmann, Anton; Ernst, Dieter

    2011-01-01

    A field study was conducted at the Russell E. Larson Agricultural Research Center to determine the effect of transgenic glyphosate-resistant soybean in combination with herbicide (Roundup) application on its endosymbiont Bradyrhizobium japonicum. DNA of bacteroids from isolated nodules was analysed for the presence of the transgenic 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSPS) DNA sequence using polymerase chain reaction (PCR). To further assess the likelihood that the EPSPS gene may be transferred from the Roundup Ready (RR) soybean to B. japonicum, we have examined the natural transformation efficiency of B. japonicum strain 110spc4. Analyses of nodules showed the presence of the transgenic EPSPS DNA sequence. In bacteroids that were isolated from nodules of transgenic soybean plants and then cultivated in the presence of glyphosate this sequence could not be detected. This indicates that no stable horizontal gene transfer (HGT) of the EPSPS gene had occurred under field conditions. Under laboratory conditions, no natural transformation was detected in B. japonicum strain 110spc4 in the presence of various amounts of recombinant plasmid DNA. Our results indicate that no natural competence state exists in B. japonicum 110spc4. Results from field and laboratory studies indicate the lack of functional transfer of the CP4-EPSPS gene from glyphosate-tolerant soybean treated with glyphosate to root-associated B. japonicum.

  12. Effect of temperature on the effectiveness of artificial reproduction of dace [Cyprinidae (Leuciscus leuciscus (L.))] under laboratory and field conditions.

    PubMed

    Nowosad, Joanna; Targońska, Katarzyna; Chwaluczyk, Rafał; Kaszubowski, Rafał; Kucharczyk, Dariusz

    2014-10-01

    This study sought to determine the effect of water temperature on the effectiveness of artificial reproduction of dace brooders under laboratory and field conditions. Three temperatures were tested in the laboratory: 9.5, 12 and 14.5 °C (± 0.1 °C). The water temperature under field conditions was 11.0 ± 0.3 °C (Czarci Jar Fish Farm) and 13.2 ± 1.4 °C (Janowo Fish Farm). The study showed that artificial reproduction of dace is possible in all the temperature ranges under study and an embryo survival rate of over 87% can be achieved. Dace has also been found to be very sensitive to rapid temperature changes, even within the temperature ranges optimal for the species. Such changes have an adverse effect on the outcome of the reproduction process, such as a decrease in the percentage of reproducing females, a decrease in the pseudo-gonado-somatic index (PGSI) and a decrease in the embryo survival rate.

  13. A laboratory study of supercritical CO2 adsorption on cap rocks in the geological storage conditions

    NASA Astrophysics Data System (ADS)

    Jedli, Hedi; Jbara, Abdessalem; Hedfi, Hachem; Bouzgarrou, Souhail; Slimi, Khalifa

    2017-04-01

    In the present study, various cap rocks have been experimentally reacted in water with supercritical CO2 in geological storage conditions ( P = 8 × 106 Pa and T = 80 °C) for 25 days. To characterize the potential CO2-water-rock interactions, an experimental setup has been built to provide additional information concerning the effects of structure, thermal and surface characteristics changes due to CO2 injection with cap rocks. In addition, CO2 adsorption capacities of different materials (i.e., clay evaporate and sandstone) are measured. These samples were characterized by XRD technique. The BET specific surface area was determined by nitrogen isotherms. In addition, thermal characteristics of untreated adsorbents were analyzed via TGA method and topography surfaces are identified by Scanning Electron Microscope (SEM). Taking into account pressure and temperature, the physical as well as chemical mechanisms of CO2 retention were determined. Isotherm change profiles of samples for relative pressure range indicate clearly that CO2 was adsorbed in different quantities. In accordance with the X-ray diffraction, a crystalline phase was formed due to the carbonic acid attack and precipitation of some carbonate.

  14. Laboratory investigation of oil-suspended particulate matter aggregation under different mixing conditions.

    PubMed

    Sun, Juan; Khelifa, Ali; Zhao, Chaocheng; Zhao, Dongfeng; Wang, Zhendi

    2014-03-01

    Oil-suspended particulate matter aggregation (OSA) has been recognized by the oil spill remediation community to effectively enhance the cleansing of spilled oil in the marine environment. While studies have investigated the application of mineral fines as an effective method to facilitate oil dispersion, decision-makers still lack information on the role of mixing energy in OSA formation and its significance to oil dispersion in real spills. This work studied the effect of level and duration of mixing energy on OSA formation using the standard reference material 1,941 b and Arabian light crude oil. The results showed that dispersed small oil droplets increased with an increase of both the level and duration of mixing energy to form multi-droplet OSAs. The sizes of the dispersed droplets varied between 5 and 10 μm under different conditions studied. The maximum oil trapping efficiency increased from 23% to 33%, the oil to sediment ratio increased from 0.30 to 0.43 g oil/g sediment, and the required shaking time decreased from 2.3 to 1.1h as the shaking rate increased from 2.0 to 2.3 Hz. Based on the size measurement results, a breakage effect on the formed OSAs and sediment flocs was confirmed under high mixing energy level.

  15. Combined physical and chemical methods to control lesser mealworm beetles under laboratory conditions.

    PubMed

    Wolf, Jônatas; Potrich, Michele; Lozano, Everton R; Gouvea, Alfredo; Pegorini, Carla S

    2015-06-01

    The lesser mealworm beetle, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae), is an important insect pest. The insect acts as a disease vector and reservoir, negatively affecting the health of birds and humans, and harming poultry husbandry. Controlling the lesser mealworm is generally based on using synthetic chemical insecticides, which are sometimes ineffective, and is limited due to market concerns regarding the toxicity of chemical residues in food products. In this context, the present study aimed to evaluate the potential for the combination of physical and chemical methods to control A. diaperinus. Bioassays were conducted using poultry bedding and known populations of beetle adults and larvae. The treatments consisted of the isolated application of 400 g/m2 hydrated lime; 20% added moisture (distilled water); temperature increase to 45°C; an insecticide composed of cypermethrin, chlorpyrifos, and citronellal; and a combination of these factors. Beetle mortality was measured at 7 and 10 d of treatment. The hydrated lime and moisture treatments alone did not control A. diaperinus. Raising the temperature of the poultry bedding to 45°C effectively controlled both larvae (90±6%) and adults (90±4%). The use of insecticide provided adequate control of A. diaperinus in the conditions of the bioassay (93±2% and 68±5% for adults and larvae, respectively). The combination of the studied factors led to the total control of larvae and adults after 7 d of treatment.

  16. Methane hydrate behavior when exposed to a 23% carbon dioxide 77% nitrogen gas under conditions similar to the ConocoPhillips 2012 Ignik Sikumi Gas Hydrate Field Trial

    NASA Astrophysics Data System (ADS)

    Borglin, S. E.; Kneafsey, T. J.; Nakagawa, S.

    2013-12-01

    In-situ replacement of methane hydrate by carbon dioxide hydrate is considered to be a promising technique for producing natural gas, while simultaneously sequestering greenhouse gas in deep geological formations. For effective application of this technique in the field, kinetic models of gas exchange rates in hydrate under a variety of environmental conditions need to be established, and the impact of hydrate substitution on geophysical (seismic) properties has to be quantified in order to optimize monitoring techniques. We performed a series of laboratory tests in which we monitored changes in methane hydrate-bearing samples while a nitrogen/carbon dioxide gas mixture was flowed through. These experiments were conducted to gain insights into data obtained from a field test in which the same mixture of carbon dioxide and nitrogen was injected into a methane hydrate-bearing unit beneath the north slope of the Brooks Range in northern Alaska (ConocoPhillips 2012 Ignik Sikumi gas hydrate field trial). We have measured the kinetic gas exchange rate for a range of hydrate saturations and different test configurations, to provide an estimate for comparison to numerical model predictions. In our tests, the exchange rate decreased over time during the tests as methane was depleted from the system. Following the elution of residual gaseous methane, the exchange rate ranged from 3.8×10-7 moles methane/(mole water*s) to 5×10-8 moles methane/(mole water*s) (Note that in these rates, the moles of water refers to water originally held in the hydrate.). In addition to the gas exchange rate, we also monitored changes in permeability occurring due to the gas substitution. Further, we determined the seismic P and S wave velocities and attenuations using our Split Hopkinson Resonant Bar apparatus (e.g. Nakagawa, 2012, Rev. Sci. Instr.). In addition to providing geophysical signatures, changes in the seismic properties can also be related to changes in the mechanical strength of

  17. Persistence of four s-triazine herbicides in river, sea and groundwater samples exposed to sunlight and darkness under laboratory conditions.

    PubMed

    Navarro, Simón; Vela, Nuria; Giménez, M José; Navarro, Ginés

    2004-08-15

    The persistence of terbuthylazine, simazine, atrazine and prometryn (s-triazine herbicides) was studied in sea, river and groundwaters during long-term laboratory incubation (127 days) under different laboratory conditions (light-darkness at 20 degrees C). Analysis of herbicides was performed by GC-NPD and their identity was confirmed by GC-MSD. A micro on-line method for the isolation of herbicide residues was used. The results showed that light had little effect on the removal of the four herbicides in riverwater but had a marked effect on their removal from sea and groundwater. Surprisingly, this removal appeared to be inversely proportional to the concentration of dissolved organic materials. In general, the degradation order was similar in sea and riverwaters; simazine was the most readily degraded compound (t(1/2)= 29-49 days), while terbuthylazine was the most persistent with the longest half-lives (76-331 days). In groundwater, terbuthylazine also showed greater persistence but prometryn was the compound with a fastest degradation rate, half-lives ranged from 88 days for prometryn to approximately 100 days for the other three compounds in light conditions and 263-366 days for prometryn and terbuthylazine, respectively, in darkness. Only for terbuthylazine was the remaining percentage at the end of the experiment higher than 50% under light conditions in riverwater, while in the other cases, the remaining percentage varied from 7 to 43% for simazine in seawater and atrazine in groundwater, respectively. Finally, a greater persistence was observed in groundwater for the four compounds.

  18. Effect of thermal shock on the decomposition of rocks under controlled laboratory conditions

    NASA Astrophysics Data System (ADS)

    Kasanin-Grubin, Milica; Vezmar, Tijuana; Kuhn, Nikolaus J.

    2013-04-01

    The major factor determining the rate of weathering of a given rock are the climatic conditions of the surrounding environment, most notably type and amount of precipitation and temperature. For the latter, average annual temperature and where applicable, the frequency of freezing and thawing are often considered to be relevant for weathering. The rate of temperature change is mostly ignored. However, a rapid change in temperature, referred to as thermal shock could have more severe consequences of rock deterioration then gradual heating and cooling of rocks is gradual. Thermal shock induces a stress of such a magnitude that the material is unable to adjust fast enough and so it breaks down. The aim of this study is to examine the importance of mechanical decomposition of rocks when treated with thermal shock by freezing. The rate of decomposition of rocks of various sizes was measured based on their weight loss. In addition, they were immersed in water after freezing and the electrical conductivity and pH of the water were measured as an index for thermal-shock induced micro-fracturing. Samples of three rock types were chosen for the experiment: limestone, tuffaceous rock and basalt. Samples were examined in two separate cycles: (i) 24h immersion in ultra-clean water followed by 24h drying at 30o and (ii) 24h immersion, 24h temperature shock by freezing at -20˚C and 6h thawing. Each cycle was repeated approximately 20 times. In each cycle three different sizes of rock were examined: <16mm, 16-8mm and 8-5mm. Limestone mass decreased for both cycles, although more distinctly after repeated thermal shocks. Furthermore, the rate of decay decreased with increasing rock size. Tuffaceous rock exposed to cycle (i) also showed a significant weight loss. Somewhat surprisingly, the mass of the tuffaceous rock exposed to thermal shock increased by about 13% in all sample size groups. It is possible that pore volume increased during experiment and that the rocks became

  19. Laboratory study of microbial cleaning of oil spills under Saudi environmental conditions

    SciTech Connect

    El-Sayed, A.A.H.; Shebl, A.M.; Ramadan, M.A.

    1995-11-01

    An active strain of Pseudomonas sp. isolated from oil-contaminated soil at the Arabian Gulf was able to utilize the crude oil at a concentration of 5 mg/ml added to sterile Gulf water. microbial growth and gas chromatographic analysis of the remaining oil were used as a criteria for oil degradation by this strain. The bacteria at a cell density of 10{sup 5} CFU/ml was able to degrade the crude oil at concentrations ranged from 2.5 to 15 mg/ml in Gulf water samples. At low concentration (2.5 mg/ml), about 70% of crude oil had disappeared within 7 days. At high concentration (15 mg/ml), the extent of oil degradation decreased, where only 50% of the added oil had disappeared. The rate of degradation by the inoculated bacteria was slightly increased by the addition of inorganic nutrients, mainly P or N to the Gulf water. The degradative capacity of Pseudomonas sp. was optimum when the bacteria was incubated at 25 C, where 47% of the added oil has disappeared within 5 days of incubation. Low cell density (10{sup 3} CFU/ml) of the degrading bacteria required a long lag period before initiation of oil degradation, whereas high cell density (10{sup 6} CFU/ml) rapidly degraded oil with a short lag period under the same conditions. This strain could be useful in decontamination of spilled oil in Gulf water if it acts well under field trial test and survived for a reasonable period sufficient for oil biodegradation.

  20. Comparative studies on the ecophysiological differences of two green tide macroalgae under controlled laboratory conditions.

    PubMed

    Wang, Ying; Wang, You; Zhu, Lin; Zhou, Bin; Tang, Xuexi

    2012-01-01

    Yellow Sea green tides have occurred in coastal China almost every year from 2007 to 2011. Ulva prolifera (Müller) J. Agardh has been identified as the causative macroalgal species. U. intestinalis, however, has been observed in the bloom areas, co-occurring with U. prolifera, but it has not been found to be causative. The Yellow Sea green tide has shown consistent phases of development that match corresponding environmental changes. U. prolifera, not U. intestinalis, is dominant. Our experimental design was based on these observed phenomena, and the results of our field investigation indicated a close relationship between changes in principal environmental factors (irradiance, temperature, and salinity) and the development of each phase of the bloom. These main environmental factors were simulated to allow estimation and comparison of the physiological responses of U. prolifera and U. intestinalis. Ecophysiological differences were found between these two species. (1) More photosynthetic activity and plasticity were detected in U. prolifera. (2) U. prolifera was found to be more sensitive to dynamic environments, especially harsh and changing environmental conditions. U. intestinalis was found to be more stable, probably due to the higher stress tolerance given by its antioxidant system. (3) Markedly higher nutrient absorption activity was observed in U. prolifera. Comparisons of the ecophysiological traits of these two species in this present study may foster understanding of their natural ecological processes. Specifically, U. prolifera seemed to be more engaged with the ephemeral blooms, while U. intestinalis seemed to be directed toward persistence. This also suggests that the ecological success of U. prolifera may be inextricably linked to its higher capacity for photosynthesis, nutrient absorption, and nutrient assimilation.

  1. Laboratory Test Methods to Determine the Degradation of Plastics in Marine Environmental Conditions

    PubMed Central

    Tosin, Maurizio; Weber, Miriam; Siotto, Michela; Lott, Christian; Degli Innocenti, Francesco

    2012-01-01

    In this technology report, three test methods were developed to characterize the degradation of plastic in marine environment. The aim was to outline a test methodology to measure the physical and biological degradation in different habitats where plastic waste can deposit when littered in the sea. Previously, research has focused mainly on the conditions encountered by plastic items when floating in the sea water (pelagic domain). However, this is just one of the possible habitats that plastic waste can be exposed to. Waves and tides tend to wash up plastic waste on the shoreline, which is also a relevant habitat to be studied. Therefore, the degradation of plastic items buried under sand kept wet with sea water has been followed by verifying the disintegration (visual disappearing) as a simulation of the tidal zone. Most biodegradable plastics have higher densities than water and also as a consequence of fouling, they tend to sink and lay on the sea floor. Therefore, the fate of plastic items lying on the sediment has been followed by monitoring the oxygen consumption (biodegradation). Also the effect of a prolonged exposure to the sea water, to simulate the pelagic domain, has been tested by measuring the decay of mechanical properties. The test material (Mater-Bi) was shown to degrade (total disintegration achieved in less than 9 months) when buried in wet sand (simulation test of the tidal zone), to lose mechanical properties but still maintain integrity (tensile strength at break = −66% in 2 years) when exposed to sea water in an aquarium (simulation of pelagic domain), and substantially biodegrade (69% in 236 days; biodegradation relative to paper: 88%) when located at the sediment/sea water interface (simulation of benthic domain). This study is not conclusive as the methodological approach must be completed by also determining degradation occurring in the supralittoral zone, on the deep sea floor, and in the anoxic sediment. PMID:22737147

  2. Laboratory test methods to determine the degradation of plastics in marine environmental conditions.

    PubMed

    Tosin, Maurizio; Weber, Miriam; Siotto, Michela; Lott, Christian; Degli Innocenti, Francesco

    2012-01-01

    In this technology report, three test methods were developed to characterize the degradation of plastic in marine environment. The aim was to outline a test methodology to measure the physical and biological degradation in different habitats where plastic waste can deposit when littered in the sea. Previously, research has focused mainly on the conditions encountered by plastic items when floating in the sea water (pelagic domain). However, this is just one of the possible habitats that plastic waste can be exposed to. Waves and tides tend to wash up plastic waste on the shoreline, which is also a relevant habitat to be studied. Therefore, the degradation of plastic items buried under sand kept wet with sea water has been followed by verifying the disintegration (visual disappearing) as a simulation of the tidal zone. Most biodegradable plastics have higher densities than water and also as a consequence of fouling, they tend to sink and lay on the sea floor. Therefore, the fate of plastic items lying on the sediment has been followed by monitoring the oxygen consumption (biodegradation). Also the effect of a prolonged exposure to the sea water, to simulate the pelagic domain, has been tested by measuring the decay of mechanical properties. The test material (Mater-Bi) was shown to degrade (total disintegration achieved in less than 9 months) when buried in wet sand (simulation test of the tidal zone), to lose mechanical properties but still maintain integrity (tensile strength at break = -66% in 2 years) when exposed to sea water in an aquarium (simulation of pelagic domain), and substantially biodegrade (69% in 236 days; biodegradation relative to paper: 88%) when located at the sediment/sea water interface (simulation of benthic domain). This study is not conclusive as the methodological approach must be completed by also determining degradation occurring in the supralittoral zone, on the deep sea floor, and in the anoxic sediment.

  3. Effects of sulfur dioxide, hydrogen peroxide and sulfuric acid on the de novo synthesis of PCDD/F and PCB under model laboratory conditions.

    PubMed

    Pekárek, V; Puncochár, M; Bures, M; Grabic, R; Fiserová, E

    2007-01-01

    In a laboratory model system consisting of fly ash from municipal waste incinerator, CuCl2 x 2H2O, NaCl and activated carbon in N2 + 10% O2 atmosphere, the de novo synthetic reactions of formation of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) were studied under laboratory conditions in the presence of sulfur dioxide, hydrogen peroxide, and sulfuric acid. It has been found that the formation of PCDD is suppressed by sulfur dioxide more efficiently than the formation of PCDF. A similar effect has also been observed in the presence of hydrogen peroxide. The formation of PCDF is strongly suppressed in the presence of sulfuric acid. On the basis of the experimental results and thermodynamic calculations, the following mechanisms are proposed and discussed: oxidative destruction of PCDD and PCDF oxygen rings, conversion of cupric chloride and possibly also cupric oxide into the non-reactive sulfate, and the Deacon oxychlorination processes catalyzed by cupric chloride.

  4. Isolation of entomopathogenic nematodes in an apple orchard in Southern Brazil and its virulence to Anastrepha fraterculus (Diptera: Tephritidae) larvae, under laboratory conditions.

    PubMed

    Foelkel, E; Voss, M; Monteiro, L B; Nishimura, G

    2017-03-01

    Entomopathogenic nematodes (EPNs) are a promising alternative to integrated control in many fruit pests. Few studies were made on the relationship of Anastrepha fraterculus natural population with native EPNs population and other biotic and abiotic factors. The aim of this work was to verify the occurrence of endemic nematodes in an apple orchard, concerning environmental conditions and technical procedure, and access isolates virulence to A. fraterculus larvae. The experiment was conducted during a year taking monthly soil samples from an apple orchard, with and without fallen fruits just above the soil. Samples were baited with Tenebrium molitor and A. fraterculus larvae in laboratory. Canopy and fallen fruits were sampled to access the pest infestation. Seventy three EPN isolates were captured, in 23.2% soil samples, more with T. molitor than with A. fraterculus baits. From the 20 isolates tested against A. fraterculus, only five were pathogenic, and they were identified as Oscheius sp. The nematodes were captured during all seasons in a similar frequency. Soil and weather conditions, presence of fruit over the orchard soil, and A. fraterculus pupae in the fruits had no significant influence on the capture. As a conclusion, nematodes of the genera Oscheius are found in an apple orchard of Porto Amazonas constantly along the year, independently of fluctuations in A. fraterculus population, climate conditions and presence of fruit over the soil. Some of the isolates are pathogenic to A. fraterculus.

  5. Soil Water Content Sensor Response to Organic Matter Content under Laboratory Conditions

    PubMed Central

    Fares, Ali; Awal, Ripendra; Bayabil, Haimanote K.

    2016-01-01

    environmental conditions. PMID:27527185

  6. [Myocardial electrogenesis in laboratory rats under conditions of acute nitrite intoxication].

    PubMed

    Shumilova, T E; Shereshkov, V I; Ianvareva, I N; Nozdrachev, A D

    2010-01-01

    In anesthetized male rats the arterial blood pressure in femoral artery and electrocardiogram in standard leads were recorded uninterruptedly for 1-1.5 h under conditions of acute nitrite intoxication produced by a subcutaneous injection of water solution of sodium nitrite (donor of nitric oxide) at concentrations of 10, 30, and 50 mg/kg body mass. Results of the study have shown dose-dependent changes of arterial pressure as well as of time and amplitude characteristics of electrocardiogram under effect of NaNO2. At the threshold hypoxic dose, an increase of amplitude of R and S waves was observed by the 30-45th min, while at the maximal NaNO2 dose, amplitude of all waves rose by the 15th min of intoxication. High nitric doses often caused an increase of the ST segment above the isoelectric line and a rise of the amplitude of the T wave, on which a notch appeared in some cases. The change of the ECG time parameters was expressed in the dose-dependent development of bradycardia for the first 4-7 min; its level correlated with the progressively decreasing arterial pressure in the beginning (the 2-4th min) of nitrite intoxication. Variation analysis of heart rate spectral characteristics by Baevskii has revealed a rise of the total spectral power of pulse oscillations. Under effect of nitrite, in the spectrum of cardiointervals, quent recovery of the normal ECG spectrum in the end of the experimental period. The maximal nitrite dose produced more pronounced shifts of the heart rate spectrum towards the LF and VLF diapasons that were not restored for 1 h of experiment. Transitory processes of readjustment of the cardiac rhythm had discrete character. The nitrite dose of 50 mg/kg body mass increased the RR-interval after 4-7 min with amplitude steps of 3-5 imp/s and the time constant of 20-40 s. The revealed ECG changes had the reflex (enhancement of parasympathetic tonus) and metabolic (the hypoxic and histotoxic damage of myocardium) nature.

  7. Soil Water Content Sensor Response to Organic Matter Content under Laboratory Conditions.

    PubMed

    Fares, Ali; Awal, Ripendra; Bayabil, Haimanote K

    2016-08-05

    environmental conditions.

  8. Laboratory measurements of the 5-20 cm wavelength opacity of ammonia, water vapor, and methane under simulated conditions for the deep jovian atmosphere

    NASA Astrophysics Data System (ADS)

    Bellotti, Amadeo; Steffes, Paul G.; Chinsomboom, Garrett

    2016-12-01

    Over the past decade, several extensive laboratory studies have been conducted of the microwave opacity of ammonia and water vapor in preparation for interpretation of the precise measurements of jovian microwave emission to be made with the Microwave Radiometer (MWR) instrument aboard the NASA Juno Mission. (See, e.g., Hanley et al. [2009] Icarus, 202, 316-335; Karpowicz and Steffes [2011a] Icarus 212, 210-223; Karpowicz and Steffes [2011b] Icarus 214, 783; Devaraj et al. [2014] Icarus, 241, 165-179) These works included models for the opacity of these constituents valid over the pressure and temperature ranges measured in the laboratory experiments (temperatures up to 500 K and pressures up to 100 bars). However, studies of the microwave emission made using these models indicate that significant contributions to the emission at the 24-cm and 50-cm wavelengths to be measured by the Juno MWR will be made by layers of the atmosphere with temperatures at or exceeding 600 K. While the ammonia opacity models described by Hanley et al. (2009) and Devraj et al. (2014) give consistent results at temperatures up to 500 K (within 6%), they diverge significantly at temperatures and pressures exceeding 550 K and 50 bars, respectively. Similarly, at temperatures above 500 K, the model for water vapor opacity developed by Karpowicz and Steffes (2011a,b) exhibits non-physical attributes. To resolve these ambiguities, we have conducted laboratory measurements of the microwave opacity of ammonia at temperatures up to 600 K and that for water vapor at temperatures up to 600 K. Additionally, since the microwave opacity of ammonia is influenced by pressure-broadening from methane (a significant constituent in jovian atmospheres), measurements of the effects of methane on the ammonia absorption spectrum have also been conducted. These measurements have resulted in updated models for the opacities of ammonia and water vapor under conditions of the deep jovian atmosphere.

  9. In situ Analysis of Organic Matter in Martian Soil: Laboratory Measurements Under Martian Operating Conditions Supporting Treatment and Interpretation of SAM GC-MS Data

    NASA Astrophysics Data System (ADS)

    Millan, M.; Szopa, C.; Coll, P.; Buch, A.; Cabane, M.; Coscia, D.; Glavin, D. P.; Freissinet, C.

    2014-07-01

    This work presents laboratory measurements under martian operating conditions in comparison with the SAM GC-MS data provided by the Curiosity rover. Their treatment and interpretation supports the in situ analysis of organic matter on Mars.

  10. Comparison of longevity between a laboratory strain and a natural population of Anastrepha Fraterculus (Diptera: Tephritidae) under field cage conditions

    SciTech Connect

    Gomez Cendra, P.; Vilardi, J.; Segura, D.; Cladera, J.; Allinghi, A.

    2007-03-15

    The South American fruit fly Anastrepha fraterculus (Wiedemann) is one of the most destructive fruit pests in this region, infesting major fruit crops. Implementation of the sterile insect technique (SIT) as part of an area-wide integrated approach against this species requires information on the survival of mass-reared and sterilized insects in the field and their ability to mate with wild females. The survival rates in field cages of both non-irradiated and irradiated laboratory flies were compared with that of wild flies. Both types of laboratory flies survived longer than their wild counterparts over the 8 days under the experimental conditions. The irradiation dose (70 Gy) did not affect survival of the laboratory reared flies. Our results improve the prospect of integrating the SIT into the control of A. fraterculus populations in Argentina. (author) [Spanish] Anastrepha fraterculus (Wiedemann), la mosca sudamericana de la fruta, es una de las plagas mas destructivas en la region que infesta a los principales cultivos de frutas. La implementacion de la Tecnica del Insecto Esteril (TIE) como parte de un manejo integrado en areas extensivas contra esta especie requiere ensayos que demuestren que los insectos producidos en forma masiva y esterilizados son capaces de sobrevivir en el campo y aparearse con las hembras silvestres. Se comparo la supervivencia de individuos de una linea de laboratorio, tanto irradiados como no irradiados con la de individuos de una poblacion natural. Los dos tratamientos de moscas de laboratorio sobrevivieron mas tiempo que las salvajes durante los 8 dias y en las condiciones ensayadas. La dosis de radiacion (70 Gy.) no afecto la supervivencia de las moscas criadas en laboratorio. Nuestros resultados mejoran las perspectivas de integrar la TIE en el control de las poblaciones argentinas de A. fraterculus. (author)

  11. Exploring correlation between redox potential and other edaphic factors in field and laboratory conditions in relation to methane efflux.

    PubMed

    Singh, S N

    2001-10-01

    Methane is primarily a biogenic gas, which is implicated in global warming. Although its production in the anoxic conditions is regulated by several edaphic factors, aquatic macrophytes also influence methane emission by providing aerenchyma to act as chimney for CH4 transport from the sediment to troposphere, by releasing root exudates to the sediment to serve as substrate for methanogenic bacteria and by transporting atmospheric O2 to rhizosphere, which stimulates CH4 consumption. Among the edaphic factors, redox potential (Eh) is the most important, which largely determines the action of methanogenic bacteria. Hence, a study was undertaken first to find out the correlation between CH4 emission and edaphic factors in the field conditions and then to understand the relationship between Eh and other edaphic factors. The field studies revealed that natural wetlands were the major source of CH4 emission, and the vegetation plays an important role in CH4 emission from the water bodies. However, it was very difficult to establish a strong relationship between the CH4 emission and the edaphic factors in the field conditions due to other limiting factors and their constant fluctuations. In this connection, the laboratory experiments exhibited that soil temperature, pH, moisture regime and incubation period were negatively correlated with Eh, which determines the initiation of methanogenic process. However, organic carbon and the water regime over the soil surface did not show any impact on Eh in this study.

  12. Selective oviposition by Aedes aegypti (Diptera: culicidae) in response to Mesocyclops longisetus (Copepoda: Cyclopoidea) under laboratory and field conditions.

    PubMed

    Torres-Estrada, J L; Rodríguez, M H; Cruz-López, L; Arredondo-Jimenez, J I

    2001-03-01

    The influence of predacious Mesocyclops longisetus Thiebaud on the selection of oviposition sites by prey Aedes aegypti (L.) was studied under laboratory and field conditions. In both cases, gravid Ae. aegypti females were significantly more attracted to ovitraps containing copepods or to ovitraps with water in which copepods were held previously than to distilled water. Monoterpene and sesquiterpene compounds including 3-carene, alpha-terpinene, alpha-copaene, alpha-longipinene, alpha-cedrene, and delta-cadinene were found in hexane extracts of copepods by gas chromatography and mass spectrometry analyses. These compounds may be responsible for attracting gravid Ae. aegypti females and may increase the number of potential prey for the copepod.

  13. Attraction of gravid anopheles Pseudopunctipennis females to oviposition substrates by Spirogyra majuscula (Zygnematales: Zygnmataceae) algae under laboratory conditions.

    PubMed

    Torres-Estrada, José L; Meza-Alvarez, Rosa A; Cruz-López, Leopoldo; Rodríguez, Mario H; Arredondo-Jiménez, Juan I

    2007-03-01

    The attraction of Anopheles pseudopunctipennis gravid females to oviposition substrates containing Spirogyra majuscula algae was investigated under laboratory conditions. Gravid females deposited significantly more eggs in cups containing natural algae in water from breeding sites than in cups containing artificial (nylon rope) life-like algae in water from the corresponding natural breeding site, or in cups containing natural algae in distilled water. Bioassays with Spirogyra majuscula organic extracts indicated that these extracts at concentrations of 0.1%, 0.01%, and 0.001% attracted more oviposition, but concentrations of 1%, 10%, and 100% were repellent. Gas chromatography and mass spectrometry analysis of algae organic extracts revealed a mixture of ethyl acetate and hydrocarbons compounds. These results suggest that the attraction of gravid An. pseudopunctipennis to natural breeding sites containing filamentous algae is probably mediated by organic compounds released by the algae.

  14. Molluscicidal activity of Physalis angulata L. extracts and fractions on Biomphalaria tenagophila (d'Orbigny, 1835) under laboratory conditions.

    PubMed

    dos Santos, José Augusto A; Tomassini, Therezinha Coelho B; Xavier, Deise Cristina Drummond; Ribeiro, Ivone Maria; da Silva, Melissa Teixeira G; de Morais Filho, Zenildo Buarque

    2003-04-01

    The main objective of this research is to evaluate the molluscicide activity of Physalis angulata L. Biomphalaria tenagophila specimens under laboratory conditions. Extracts and fractions were supplied by the Laborat rio de Qu mica de Produtos Naturais, Farmanguinhos-Fiocruz. Experiments were performed according to the methodology described by the World Health Organization for molluscicide tests using the concentrations from 0.1 to 500 mg/l of the extracts, fractions and of a pool of physalins modified steroids present in this species. The results show that ethyl acetate and acetone extracts from the whole plant, the ethanolic extracts of the roots and the physalins pool from stems and leaves were active. Only the whole plant extracts were available in sufficient quantity for the determination of LD50 and LD90 values.

  15. Impacts of Bt rice expressing Cry1C or Cry2A protein on the performance of nontarget leafhopper, Nephotettix cincticeps (Hemiptera: Cicadellidae), under laboratory and field conditions.

    PubMed

    Lu, Z B; Tian, J C; Wang, W; Xu, H X; Hu, C; Guo, Y Y; Peng, Y F; Ye, G Y

    2014-02-01

    Transgenic rice expressing Bacillus thuringiensis Berliner (Bt) protein can effectively control target insects including stem borers and leaf folders. However, the potential effects of Bt rice on nontarget organisms including nontarget herbivores have not been fully evaluated. In the current study, ecological fitness parameters of the nontarget herbivore, Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae), fed on T1C-19 (Cry1C) or T2A-1 (Cry2A) rice were compared with non-Bt rice (MH63) under laboratory conditions. A 2-yr field trial was also conducted to monitor the population dynamics of N. cincticeps in the Bt and control rice plots using the vacuum-suction machine and yellow sticky card traps. Laboratory results showed that there were no significant differences in some of biological parameters including egg developmental duration, adult fresh weight, adult longevity, and oviposition period when N. cincticeps fed on Bt or non-Bt rice was compared. However, the survival rate of N. cincticeps nymphs fed on T2A-1 Bt rice plants was significantly higher than that on the control. When N. cincticeps fed on T1C-19 Bt rice plants, its nymphal duration was significantly longer and fecundity significantly lower compared with those fed on both T2A-1 Bt and non-Bt rice plants; the preoviposition period of N. cincticeps fed on T1C-19 and T2A-1 Bt rice was also significantly shorter than those on non-Bt rice. Nonetheless, both seasonal density and population dynamics of N. cincticeps adults and nymphs were similar between Bt (T1C-19 and T2A-1) and non-Bt rice plots under field conditions. In conclusion, our results indicate that our two tested Bt rice lines would not lead to higher population of N. cincticeps. Long-term experiments to monitor the population dynamics of N. cincticeps at large scale need to be carried out to confirm the current results.

  16. Influence of the redox condition dynamics on the removal efficiency of a laboratory-scale constructed wetland.

    PubMed

    Wiessner, A; Kappelmeyer, U; Kuschk, P; Kästner, M

    2005-01-01

    A laboratory reactor planted with Juncus effusus treating an artificial wastewater was used to investigate the short-term and long-term variations and interactions in the redox conditions as well as the removal efficiency of C and the N turnover. The permanent circulation of the process water enabled the micro-gradient processes to be evaluated for an operating period of 20 months. Steady-state conditions were achieved throughout the operating period with high mean removal efficiencies of 92.7% total organic carbon, 82.0% ammonia and 97.6% nitrate. Daily variations in the redox state of the rhizosphere of a few hundred mV were observed, ranging from about -200 to oxidized conditions of about +200 mV and driven by daylight. Variations in pH associated with changes in light and redox were linked to the dynamics of the fates of organic and inorganic carbon species. The ammonia removal processes were found to be firmly established, including for moderately reduced redox conditions with high efficiencies for E(h)>-50 mV. The enrichment of ammonia (up to 13 mg l(-1)) closely linked to the light, particularly during summertime, indicates the existence of hitherto unconsidered additional N turnover pathways in the rhizoplane involving N(2) produced by microbes or released by plants. C turnover was strongly related to the seasonal variation in illumination with minimum efficiencies during the dark season. In addition, it was characterized by oscillation with periods of approximately 1 month. The relationships found are dominant for biofilms on the rhizoplane and decisive for the removal efficiency of especially simple constructed and natural wetlands. The results highlight the importance of helophytes and their physiological specifics for removal processes.

  17. A comparison of the bioaccumulation potential of three freshwater organisms exposed to sediment-associated contaminants under laboratory conditions.

    PubMed

    Van Geest, Jordana L; Poirier, David G; Solomon, Keith R; Sibley, Paul K

    2011-04-01

    In the field of sediment quality assessment, increased support has been expressed for using multiple species that represent different taxa, trophic levels, and potential routes of exposure. However, few studies have compared the bioaccumulation potential of various test species over a range of sediment contaminants (hydrophobic organics and metals). As part of the development and standardization of a laboratory bioaccumulation method for the Ontario Ministry of the Environment, the oligochaete Lumbriculus variegatus, mayfly nymph Hexagenia spp., and juvenile fathead minnow Pimephales promelas were exposed to a variety of field-contaminated sediments (n = 10) to evaluate their relative effectiveness for accumulating different contaminants (e.g., dichlorodiphenyltrichloroethane [DDT] and metabolites, polychlorinated biphenyls [PCBs), polycyclic aromatic hydrocarbons [PAHs), polychlorinated dibenzo-p-dioxins and dibenzofurans [PCDD/Fs), and heavy metals). Bioaccumulation was usually highest in L. variegatus but also most variable within and (relative measures) between sediments. Bioaccumulation was similar between L. variegatus and Hexagenia spp. in most of the sediments tested. Significant differences in bioaccumulation between species were observed for DDT, dichlorodiphenyldichloroethane (DDD), PAHs, and PCDD/Fs. The present study indicates that species-specific differences in bioaccumulation may, but do not always, exist and can vary with contaminant and sediment type. The choice of test species or combination to use in a standard test method may depend on the objectives of the sediment quality assessment and data requirements of an ecological risk assessment. The results of the present study provide insight for selection of test species and validation of laboratory methods for assessing bioaccumulation with these species, as well as valuable information for interpreting results of bioaccumulation tests.

  18. Environmental Conditions Outweigh Geographical Contiguity in Determining the Similarity of nifH-Harboring Microbial Communities in Sediments of Two Disconnected Marginal Seas

    PubMed Central

    Zhou, Haixia; Dang, Hongyue; Klotz, Martin G.

    2016-01-01

    between the shallow-water and deep-water sediment diazotrophic communities and suggests that the in situ physical and geochemical conditions play a more important role than geographical contiguity in determining the community similarity of the diazotrophic microbiota in marginal sea sediments. PMID:27489551

  19. No evidence for memory interference across sessions in food hoarding marsh tits Poecile palustris under laboratory conditions.

    PubMed

    Urhan, A Utku; Brodin, Anders

    2015-05-01

    Scatter hoarding birds are known for their accurate spatial memory. In a previous experiment, we tested the retrieval accuracy in marsh tits in a typical laboratory set-up for this species. We also tested the performance of humans in this experimental set-up. Somewhat unexpectedly, humans performed much better than marsh tits. In the first five attempts, humans relocated almost 90 % of the caches they had hidden 5 h earlier. Marsh tits only relocated 25 % in the first five attempts and just above 40 % in the first ten attempts. Typically, in this type of experiment, the birds will be caching and retrieving many times in the same sites in the same experimental room. This is very different from the conditions in nature where hoarding parids only cache once in a caching site. Hence, it is possible that memories from previous sessions will disturb the formation of new memories. If there is such proactive interference, the prediction is that success should decay over sessions. Here, we have designed an experiment to investigate whether there is such memory interference in this type of experiment. We allowed marsh tits and humans to cache and retrieve in three repeated sessions without prior experience of the arena. The performance did not change over sessions, and on average, marsh tits correctly visited around 25 % of the caches in the first five attempts. The corresponding success in humans was constant across sessions, and it was around 90 % on average. We conclude that the somewhat poor performance of the marsh tits did not depend on proactive memory interference. We also discuss other possible reasons for why marsh tits in general do not perform better in laboratory experiments.

  20. Shoot-level terpenoids emission in Norway spruce (Picea abies) under natural field and manipulated laboratory conditions.

    PubMed

    Esposito, Raffaela; Lusini, Ilaria; Kristýna Večeřová; Petra Holišová; Pallozzi, Emanuele; Guidolotti, Gabriele; Urban, Otmar; Calfapietra, Carlo

    2016-11-01

    Norway spruce (Picea abies) is a strong emitter of biogenic volatile organic compounds (BVOCs). In the present study we investigated how shoot canopy position and high levels of stressors such as high temperature and ozone concentration, affect BVOC emission rates by means of in-situ and ex-situ experimental measurements. Therefore, BVOC emission from current-year spruce shoots was investigated under field and manipulated (temperature, ozone) laboratory conditions. Emitted BVOCs were sampled on desorption tubes, coupled with gas-exchange measurements of CO2 assimilation rate and stomatal conductance, and detected by gas chromatography coupled with mass spectrometry. Total BVOC emission rates from sun shoots under standard conditions were higher than those from shade shoots, although this was significant only in July, on the contrary, only α-pinene and γ-terpinene emission rates showed significant differences between sun and shade acclimated shoots in August. Limonene, α-pinene, β-pinene, and myrcene were identified as the most abundant BVOCs in both campaigns with emission rates above 0.2 nmol m(-2) s(-1). Ex-situ measurements revealed a significantly higher total BVOC emissions under high temperature level (40 °C) by ca. 175% as compared with standard temperature (30 °C), while a short-term fumigation of acute O3 concentration (200 ppb) had no effect on BVOC emissions and its spectrum. These findings might have a relevance considering the role of these compounds in protecting against oxidative stress and their possible stimulation in particular stressful conditions. Implication of such results into emission models may contribute to a more accurate estimation of BVOC emissions for Central European mountain regions dominated by Norway spruce forests and their rate under predicted climate change.

  1. Life history and life tables of Bactericera cockerelli (Hemiptera: Psyllidae) on potato under laboratory and field conditions in the lower Rio Grande Valley of Texas.

    PubMed

    Yang, Xiang-Bing; Zhang, Yong-Mei; Hua, Lei; Liu, Tong-Xian

    2010-10-01

    Effective management of potato 'Zebra Chip' (ZC) disease caused by Cadidatus Liberibacter psyllaurous (syn. solanacearum) depends on the management of its insect vector insect, potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Psyllidae). To elucidate the age-specific population dynamics of B. cockerelli, the life-table parameters were determined on potato, Solanum tuberosum L., under both laboratory and field conditions in the Lower Rio Grande Valley (LRGV) of Texas. Generally, survival, fecundity, and longevity of B. cockerelli were significantly greater under laboratory than under field conditions. The mortality under laboratory conditions was mainly due to natural intrinsic mortality. However, under field conditions, most (83.2%) B. cockerelli were missing, and of those that were not, they developed slower, and had shorter preoviposition period, shorter oviposition period, shorter longevity, lower fecundity, and higher mortality than those under laboratory conditions. As a result, most of the life-table parameters of B. cockerelli, including the intrinsic rate of increase, finite rate of increase, and net reproductive rate, were significantly lower in the field under the environmental conditions of the LRGV of Texas than in the laboratory. The information could help increase our understanding of the epidemiology of the ZC diseases associated with the pathogens transmitted by this insect pest.

  2. In search of water vapor on Jupiter: Laboratory measurements of the microwave properties of water vapor under simulated jovian conditions

    NASA Astrophysics Data System (ADS)

    Karpowicz, Bryan M.; Steffes, Paul G.

    2011-03-01

    Detection and measurement of atmospheric water vapor in the deep jovian atmosphere using microwave radiometry has been discussed extensively by Janssen et al. (Janssen, M.A., Hofstadter, M.D., Gulkis, S., Ingersoll, A.P., Allison, M., Bolton, S.J., Levin, S.M., Kamp, L.W. [2005]. Icarus 173 (2), 447-453.) and de Pater et al. (de Pater, I., Deboer, D., Marley, M., Freedman, R., Young, R. [2005]. Icarus 173 (2), 425-447). The NASA Juno mission will include a six-channel microwave radiometer system (MWR) operating in the 1.3-50 cm wavelength range in order to retrieve water vapor abundances from the microwave signature of Jupiter (see, e.g., Matousek, S. [2005]. The Juno new frontiers mission. Tech. Rep. IAC-05-A3.2.A.04, California Institute of Technology). In order to accurately interpret data from such observations, nearly 2000 laboratory measurements of the microwave opacity of H2O vapor in a H2/He atmosphere have been conducted in the 5-21 cm wavelength range (1.4-6 GHz) at pressures from 30 mbars to 101 bars and at temperatures from 330 to 525 K. The mole fraction of H2O (at maximum pressure) ranged from 0.19% to 3.6% with some additional measurements of pure H2O. These results have enabled development of the first model for the opacity of gaseous H2O in a H2/He atmosphere under jovian conditions developed from actual laboratory data. The new model is based on a terrestrial model of Rosenkranz et al. (Rosenkranz, P.W. [1998]. Radio Science 33, 919-928), with substantial modifications to reflect the effects of jovian conditions. The new model for water vapor opacity dramatically outperforms previous models and will provide reliable results for temperatures from 300 to 525 K, at pressures up to 100 bars and at frequencies up to 6 GHz. These results will significantly reduce the uncertainties in the retrieval of jovian atmospheric water vapor abundances from the microwave radiometric measurements from the upcoming NASA Juno mission, as well as provide a clearer

  3. Repellent properties of celery, Apium graveolens L., compared with commercial repellents, against mosquitoes under laboratory and field conditions.

    PubMed

    Tuetun, Benjawan; Choochote, Wej; Kanjanapothi, Duangta; Rattanachanpichai, Eumporn; Chaithong, Udom; Chaiwong, Prasong; Jitpakdi, Atchariya; Tippawangkosol, Pongsri; Riyong, Duangrat; Pitasawat, Benjawan

    2005-11-01

    In our search for new bioactive products against mosquito vectors, we reported the slightly larvicidal and adulticidal potency, but remarkable repellency of Apium graveolens both in laboratory and field conditions. Repellency of the ethanolic preparation of hexane-extracted A. graveolens was, therefore, investigated and compared with those of 15 commercial mosquito repellents including the most widely used, DEET. Hexane-extracted A. graveolens showed a significant degree of repellency in a dose-dependent manner with vanillin added. Ethanolic A. graveolens formulations (10-25% with and without vanillin) provided 2-5 h protection against female Aedes aegypti. Repellency that derived from the most effective repellent, 25% of hexane-extracted A. graveolens with the addition of 5% vanillin, was comparable to the value obtained from 25% of DEET with 5% vanillin added. Moreover, commercial repellents, except formulations of DEET, showed lower repellency than that of A. graveolens extract. When applied on human skin under field conditions, the hexane-extracted A. graveolens plus 5% vanillin showed a strong repellent action against a wide range of mosquito species belonging to various genera. It had a protective effect against Aedes gardnerii, Aedes lineatopennis, Anopheles barbirostris, Armigeres subalbatus, Culex tritaeniorhynchus, Culex gelidus, Culex vishnui group and Mansonia uniformis. The hexane-extracted A. graveolens did not cause a burning sensation or dermal irritation when applied to human skin. No adverse effects were observed on the skin or other parts of the human volunteers' body during 6 months of the study period or in the following 3 months, after which time observations ceased. Therefore, A. graveolens can be a potential candidate for use in the development of commercial repellents that may be an alternative to conventional synthetic chemicals, particularly in community vector control applications.

  4. Influence of water hardness on accumulation and elimination of cadmium in two aquatic mosses under laboratory conditions.

    PubMed

    Gagnon, C; Vaillancourt, G; Pazdernik, L

    1998-01-01

    This study investigated the effect of water hardness on the accumulation and elimination of cadmium (Cd) by two aquatic mosses, Fontinalis dalecarlica and Platyhypnidium riparioides, under laboratory conditions. The two mosses were exposed to nominal Cd concentrations of 0, 0.8, 2, and 10 microg . L-1, which includes the concentration range generally found in nature. The influence of three levels of water hardness (very soft: 11.7 mg . L-1; soft: 44.2 mg . L-1; and hard water: 92.3 mg . L-1 as CaCO3) was measured while maintaining the alkalinity and pH constant during the 28-day exposure. The Cd accumulation by the aquatic mosses was rapid, showing the potential of accumulation and the sensitivity of this biomonitor. Even if the actual Cd concentration in the water was low (concentration <0.15 microg . L-1 to 6.82 microg . L-1 of Cd), the uptake of Cd was very fast and mostly linear. This study was conducted in water hardness comparable to that found in the Canadian shield (hardness was <100 mg . L-1 as CaCO3). When the actual Cd concentration in the water was as high as 6.82 microg . L-1, the uptake of Cd was mostly linear and the steady state condition was not reach. Accumulation rates of Cd were significantly different when the mosses were in very soft (11.7 mg . L-1) as compared to hard water (92.3 mg . L-1 as CaCO3). The elimination of Cd followed a very slow process for the two species studied. The elimination rates of Cd from the mosses were not influenced by water hardness.

  5. Adulticidal Activity of Olea vera, Linum usitatissimum and Piper nigera against Anopheles stephensi and Aedes aegypti under Laboratory Conditions

    PubMed Central

    Nawaz, R; Rathor, H Rashid; Bilal, H; Hassan, SA; Khan, I Akram

    2011-01-01

    Background: There are several plant extractions which are being used for mosquito control. The aim of this study was to evaluate the efficacy of Olea vera, Linum usitatissimum and Piper nigera against Anopheles stephensi and Aedes aegypti under laboratory conditions. Methods: These tests were carried out using WHO recommended bioassay method for adult mosquitoes. Results: The extracts from black pepper was more effective as adulticide with lowest LC50 values (2.26% and 8.4%) against Aedes aegypti and Anopheles stephensi after 24 h of exposure while after 48h (1.56% and 5.11%) respectively. In terms of LC90 value black pepper was best with (8.66% and 30.1%) against Ae. aegypti and An. stephensi after 24 h of exposure while after 48h (4.59% and 17.3%) respectively. In terms of LT50 black pepper took 15 h to kill 50% tested population of Ae. aegypti while against An. stephensi it took more than 2 days. In terms of percentage mortality black pepper kill 84% of the population of Ae. aegypti and 44.75% of the An. stephensi population. Conclusion: Black pepper showed best results in term of LC50, LC90, LT50 and percentage mortality against Ae. aegypti and An. stephensi. Our study suggested that the plant extracts have potential to kill adult mosquitoes, are environment friendly and can be used for the control of mosquitoes. PMID:22808413

  6. Larval and juvenile Pacific herring Clupea pallasii are not susceptible to infectious hematopoietic necrosis under laboratory conditions

    USGS Publications Warehouse

    Hart, L.M.; Traxler, G.S.; Garver, K.A.; Richard, J.; Gregg, J.L.; Grady, C.A.; Kurath, G.; Hershberger, P.K.

    2011-01-01

    Infectious hematopoietic necrosis (IHN) leads to periodic epidemics among certain wild and farmed fish species of the Northeast (NE) Pacific. The source of the IHN virus (IHNV) that initiates these outbreaks remains unknown; however, a leading hypothesis involves viral persistence in marine host species such as Pacific herring Clupea pallasii. Under laboratory conditions we exposed specific pathogen-free (SPF) larval and juvenile Pacific herring to 103 to 104 plaque-forming units (pfu) of IHNV ml–1 by waterborne immersion. Cumulative mortalities among exposed groups were not significantly different from those of negative control groups. After waterborne exposure, IHNV was transiently recovered from the tissues of larvae but absent in tissues of juveniles. Additionally, no evidence of viral shedding was detected in the tank water containing exposed juveniles. After intraperitoneal (IP) injection of IHNV in juvenile herring with 103 pfu, IHNV was recovered from the tissues of sub-sampled individuals for only the first 5 d post-exposure. The lack of susceptibility to overt disease and transient levels of IHNV in the tissues of exposed fish indicate that Pacific herring do not likely serve a major epizootiological role in perpetuation of IHNV among free-ranging sockeye salmon Oncorhynchus nerka and farmed Atlantic salmon Salmo salar in the NE Pacific.

  7. [Establishment of optimal conditions at laboratory and pilot plant levels for the preparation of a protein isolated from Lupinus mutabilis].

    PubMed

    Rodríguez Pacheco, T; Aliaga, T; Schoeneberger, H; Gross, R

    1981-12-01

    Laboratory conditions were first investigated to determine are optimum processing parameters for the preparation of a protein isolate from the ground, defatted, commercial flakes of Lupinus mutabilis. The extraction variables were: pH (2-10); solvent to lupine ratio (5:1 to 40:1); temperature (28 degrees C - 60 degrees C) and time (10-50 min). The isoelectric point of the lupine protein was found to be pH 4.5 with a protein solubility higher than 80% above pH 8.0. Using 70-100 mesh, ground defatted flakes, and extracting at pH 8.7 for 60 min, a protein isolate was obtained on acidification to pH 4.5 which was 99.8 protein (dry basis), compared to 55.25% protein for the original material. This protein isolate represented 32% of the initial material and 57.6% of the initial nitrogen. When making pilot plant assays we found that the yield of protein isolate decreased to 20.4% of the original material and 36.4% of the initial nitrogen. The protein efficiency ratio for the protein isolate was 2.15 when supplemented with methionine, and had a digestibility of 89.33

  8. Selectivity switch in the catalytic functionalization of nonprotected carbohydrates: selective synthesis in the presence of anomeric and structurally similar carbohydrates under mild conditions.

    PubMed

    Muramatsu, Wataru; Takemoto, Yuki

    2013-03-15

    A catalytic process for the chemo- and regioselective functionalization of nonprotected carbohydrates has been developed. This novel process allows selective thiocarbonylation, acylation, and sulfonylation of a particular hydroxy group in a particular carbohydrate in the simultaneous presence of structurally similar carbohydrates such as anomers. In addition, the chemoselectivity can be switched by regulating only the length of the alkyl chain in the organotin catalyst.

  9. Depth-resolved simplified characterization of collagen depletion in dermis with polarization sensitive optical coherence tomography applicable to non-laboratory conditions

    NASA Astrophysics Data System (ADS)

    Tougbaev, Vitali; Eom, Tae Joong; Shin, Woojin; Lee, Yeung Lak; Yu, Bong-Ahn; Kee, Chul-Sik; Ko, Do-Kyeong; Lee, Jongmin

    2007-07-01

    A further insight into the prior concept of polarization sensitive optical coherence tomography system intended for non-laboratory conditions is brought forward and an experimental proof-of-concept is presented. A phenomenological model is adopted from the theory of light depolarization in crystalline polymers and modified to yield a simplified algorithm for mapping depolarization ratio in dermis. The algorithm could distinguish between dermal layers with depleted collagen content and normal dermis of normal perilesional skin. Dermis is simulated by bireringent lamellae of collagen arranged chaotically in multiple layers parallel to the skin surface. Both the design concept and the model imply the sub-millimeter tumor thickness as a proofed prognostic factor and an important criterion for complementary functional diagnostics of skin cancers at their early phase of vertical growth. Choice of the model is inspired by similarity of structural and optical properties between liquid-crystal collagen fibers in dermis and birefringent crystalline lamellae in polymer materials. The numerical computation based on the model allowing for real characteristics of dermis gives plausible interpreting of depolarization peculiarities caused by collagen depletion. Feasibility is discussed of exploiting fiber optic analogs of achromatic retarders. Fabrication of the fiber retarders is shown to be realistic by making use of the photonics technology possessed by the authors.

  10. Metabolic and cardiorespiratory reactions in tennis-players in laboratory testing and under sport-specific conditions.

    PubMed

    Smekal, G; Baron, R; Pokan, R; Dirninger, K; Bachl, N

    1995-01-01

    Metabolic and cardiorespiratory reactions were investigated during a sport-specific incremental field test (FT) for tennis and compared with a treadmill step test (TT) in a group of 13 trained male tennis players. In both the FT and the TT lactate acid (La), heart rate and oxygen uptake (VO2) were measured. VO2 was determined using a portable telemetric system (K2, Cosmed, Italy). Aerobic- (AT) and anaerobic threshold (ANT) at a blood lactate concentration of 2 mmol/l and at 4 mmol/l respectively was indicated to characterize the endurance capacity of the athletes. In both FT and TT, minimum value of lactate equivalent (LE(min)), measured in every exercise test, was also registered. At AT and ANT values for HR (AT: p < 0.001; ANT: p < 0.001) and VO2 (AT: p < 0.001; ANT: p < 0.001) were significantly higher in FT than in TT at submaximal loads. At LE(min) only higher values for HR (p < 0.05) were registered in FT. In contrast to maximum range significantly higher values for VO2 (p < 0.001) could be seen in TT (there were no significant differences for HR). Comparing maximum lactate (La(max)) subjects reached a higher lactate (p < 0.05) in TT. A particular aim of our investigation was to characterize the individual cardiopulmonal and metabolic adaptation of tennis players, considering sport-specific criteria. As a result, differences in cardiorespiratory and metabolic adaptations could be determined between laboratory TT and FT. This finding seems to point to the fact that, using field testing in addition to laboratory exercise testing, makes a better judgement of aerobic and anaerobic endurance under sport-specific conditions possible. Furthermore, it was important for us to put data, determined in the field test into practice, using the given pattern of the field test as an element of training. This kind of training has the advantage of combining an individually intensity-controlled specific endurance training for tennis with a training of technical skills.

  11. Value of Laboratory Tests in Employer-Sponsored Health Risk Assessments for Newly Identifying Health Conditions: Analysis of 52,270 Participants

    PubMed Central

    Kaufman, Harvey W.; Williams, Fred R.; Odeh, Mouneer A.

    2011-01-01

    Background Employer-sponsored health risk assessments (HRA) may include laboratory tests to provide evidence of disease and disease risks for common medical conditions. We evaluated the ability of HRA-laboratory testing to provide new disease-risk information to participants. Methodology/Principal Findings We performed a cross-sectional analysis of HRA-laboratory results for participating adult employees and their eligible spouses or their domestic partners, focusing on three common health conditions: hyperlipidemia, diabetes mellitus, and chronic kidney disease. HRA with laboratory results of 52,270 first-time participants were analyzed. Nearly all participants had access to health insurance coverage. Twenty-four percent (12,392) self-reported one or more of these medical conditions: 21.1% (11,017) self-identified as having hyperlipidemia, 4.7% (2,479) self-identified as having diabetes, and 0.7% (352) self-identified as having chronic kidney disease. Overall, 36% (n = 18,540) of participants had laboratory evidence of at least one medical condition newly identified: 30.7% (16,032) had laboratory evidence of hyperlipidemia identified, 1.9% (984) had laboratory evidence of diabetes identified, and 5.5% (2,866) had laboratory evidence of chronic kidney disease identified. Of all participants with evidence of hyperlipidemia 59% (16,030 of 27,047), were newly identified through the HRA. Among those with evidence of diabetes 28% (984 of 3,463) were newly identified. The highest rate of newly identified disease risk was for chronic kidney disease: 89% (2,866 of 3,218) of participants with evidence of this condition had not self-reported it. Men (39%) were more likely than women (33%) to have at least one newly identified condition (p<0.0001). Among men, lower levels of educational achievement were associated with modestly higher rates of newly identified disease risk (p<0.0001); the association with educational achievement among women was unclear. Even among the

  12. Effect of pyramiding Bt and CpTI genes on resistance of cotton to Helicoverpa armigera (Lepidoptera: Noctuidae) under laboratory and field conditions.

    PubMed

    Cui, Jinjie; Luo, Junyu; Van Der Werf, Wopke; Ma, Yan; Xia, Jingyuan

    2011-04-01

    Transgenic cotton (Cossypium hirsutum L.) varieties, adapted to China, have been bred that express two genes for resistance to insects, the CrylAc gene from Bacillus thuringiensis (Berliner) (Bt), and a trypsin inhibitor gene from cowpea (CpTI). Effectiveness of the double gene modification in conferring resistance to cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), was studied in laboratory and field experiments. In each experiment, performance of Bt+CpTI cotton was compared with Bt cotton and to a conventional nontransgenic variety. Larval survival was lower on both types of transgenic variety, compared with the conventional cotton. Survival of first-, second-, and third-stage larvae was lower on Bt+CpTI cotton than on Bt cotton. Plant structures differed in level of resistance, and these differences were similar on Bt and Bt + CpTI cotton. Likewise, seasonal trends in level of resistance in different plant structures were similar in Bt and Bt+CpTI cotton. Both types of transgenic cotton interfered with development of sixth-stage larvae to adults, and no offspring was produced by H. armigera that fed on Bt or Bt+CpTI cotton from the sixth stage onward. First-, second-, and third-stage larvae spent significantly less time feeding on transgenic cotton than on conventional cotton, and the reduction in feeding time was significantly greater on Bt+CpTI cotton than on Bt cotton. Food conversion efficiency was lower on transgenic varieties than on conventional cotton, but there was no significant difference between Bt and Bt+CpTI cotton. In 3-yr field experimentation, bollworm densities were greatly suppressed on transgenic as compared with conventional cotton, but no significant differences between Bt and Bt+CpTI cotton were found. Overall, the results from laboratory work indicate that introduction of the CpTI gene in Bt cotton raises some components of resistance in cotton against H. armigera, but enhanced control of H. armigera under field

  13. Good Practice Recommendations in the Field of Heating, Ventilation, and Air Conditioning for Health Related Research Laboratories.

    ERIC Educational Resources Information Center

    Laboratory Design Notes, 1966

    1966-01-01

    A collection of laboratory design notes to set forth minimum criteria required in the design of basic medical research laboratory buildings. Recommendations contained are primarily concerned with features of design which affect quality of performance and future flexibility of facility systems. Subjects of economy and safety are discussed where…

  14. Similarity considerations in one-component two-phase flow

    SciTech Connect

    Maeder, P.F.; DiPippo, R.; Dickinson, D.A.; Nikitopoulos, D.E.

    1984-07-01

    The simplified model fluid presented here for two-phase flow can serve as a basis for the similarity analysis of a variety of substance flows. For the special case of water and R114, it is seen that exact similarity does not exist in the range of interest for geothermal applications, but that conditions can be found for reasonable similarity which permit one to replace water with R114 in laboratory-size apparatus. Thus experimental data and results obtained using R114 in a properly scaled laboratory setup can be converted with reasonable accuracy to those for water.

  15. Pathogenicity of Beauveria bassiana isolated from Moroccan Argan forests soil against larvae of Ceratitis capitata (Diptera: Tephritidae) in laboratory conditions.

    PubMed

    Imoulan, Abdessamad; Elmeziane, Abdellatif

    2014-03-01

    The Mediterranean fruit fly, Ceratitis capitata Wiedemann (Diptera: Tephritidae), is the major tephritid pest in Morocco. This pest survives in Moroccan forests Argania spinosa and continually invades the nearest agricultural areas. Entomopathogenic fungi are an interesting tool for fruit fly control and hold a useful alternative to conventional insecticides. However, primary selection of effective pathogens should be taken in laboratory condition prior to applying them in the field. Here, we used third late instar larvae of C. capitata to investigate the effectiveness of 15 local Beauveria bassiana isolates. Results showed that all isolates were able to infect the larval stage, producing a large mortality rate in puparia ranging from 65 to 95 % and caused significant reduction in adult emergence. The fungal treatments revealed that the mycosis occurred also in adults escaping infection as pupariating larvae. The percentage of mycosed puparia was highest in strain TAM6.2 (95 %) followed by ERS4.16 (90 %), therefore they were the most virulent. Median lethal concentration (LC₅₀) was studied for five isolates at four concentrations ranging from 10⁵ to 10⁸ conidia ml⁻¹. The results showed that the slopes of regression lines for B. bassiana ERS4.16 (slope = 0.386) and TAM6.2 (slope = 0.41) were the most important and had the lowest LC₅₀ values (2.85 × 10³ and 3.16 × 10³ conidia ml⁻¹ respectively). This investigation suggests that the soil of Argan forests contains pathogenic B. bassiana isolates and highlights for the first time their potential as biological control toward C. capitata larval stage in Morocco.

  16. Repellency of naturally occurring volatile alcohols to fungus gnat Bradysia sp. nr. coprophila (Diptera: Sciaridae) adults under laboratory conditions.

    PubMed

    Cloyd, Raymond A; Marley, Karen A; Larson, Richard A; Dickinson, Amy; Arieli, Bari

    2011-10-01

    This study, conducted under laboratory conditions, was designed to determine the repellent activity of 10 naturally occurring volatile alcohol constituents against adults of the fungus gnat, Bradysia sp. nr. coprophila (Lintner) (Diptera: Sciaridae). The essential oil constituents were octanoic acid, furfural, acetophenone, benzaldehyde, dimethoxybenzene, borneol, menthol, 1-octen-3-ol, and 7-hydroxycitronellol, and alpha-terpineol. alpha-Terpineol, octanoic acid and furfural were tested at several concentrations, whereas the remaining seven were tested at only one concentration. The essential oil constituents' menthol, 1-octen-3-ol, and borneol displayed the most repellent activity. The mean percentage of fungus gnat adults recovered from the test compound petri dishes associated with the three essential oil constituents was between 6 and 15% compared with between 36 and 50% for the petri dishes with distilled water. The mean +/- SEM number of fungus gnat adults present in the sample compartments associated with menthol (10.4 +/- 2.6), 1-octen-3-ol (18.8 +/- 2.4), and borneol (23.4 +/- 5.6) was statistically lower than those in the petri dishes containing distilled water (60.9 +/- 7.4, 49.8 +/- 4.0, and 79.7 +/- 13.5), respectively. Only the highest concentration of alpha-terpineol (8.0 micromol) displayed significant repellent activity against fungus gnat adults. The other essential constituents tested, including octanoic acid (all three concentrations), furfural (both concentrations), acetophenone, dimethoxybenzene, and 7-hydroxycitronellol, were not statistically different from the distilled water control. The results of this study indicate that certain essential oil constituents repel fungus gnat adults, which may be useful, from a practical standpoint, in deterring adults from laying eggs into growing media.

  17. Designing of the Cooling Vest from Paraffin Compounds and Evaluation of its Impact Under Laboratory Hot Conditions

    PubMed Central

    Yazdanirad, Saeid; Dehghan, Habibollah

    2016-01-01

    Background: The phase change materials (PCMs) have the appropriate properties for controlling heat strain. One of the well-known PCMs is paraffin. This study aimed to design the cooling vest from the cheap commercial paraffin compound and evaluation of its effectiveness under laboratory hot conditions. Methods: the cooling vest was made of the polyester fabric and it had 17 aluminum packs. The each of aluminum packs was filled by 135 g of prepared paraffin with a proper melting point in the range of 15–35°C. an experimental study was conducted on ten male students under warm conditions (air temperature = 40°C, relative humidity = 40%) in a climatic chamber. Each participant was tested without cooling vest and with cooling in two activities rate on treadmill to include: light (2.8 km/h) and moderate (4.8 km/h). The time of this test was 30 min in each stage. During the test, the heart rate, the oral temperature, the skin temperature were measured every 4 min. Finally, data were analyzed using the Kolmogrov–Smirnov and repeated measurement ANOVA test in SPSS 16. Results: The latent heat of the prepared paraffin compound and the peak of the melting point were 108 kJ/kg and 30°C, respectively. The mean and standard deviation of heart rate, oral temperature, and skin temperature with cooling vest in light activity were 103.9 (12.12) beat/min, 36.77 (0.32)°C, and 31.01 (1.96)°C and in moderate activity were 109.5 (12.57) beat/min, 36.79 (0.20)°C, and 29.69 (2.23)°C, respectively. There is a significant difference between parameters with a cooling vest and without cooling (P < 0.05). Conclusions: The designed cooling vest with low cost can be used to prevent thermal strain and to increase the physiological stability against the heat. However, the latent heat of this cooling vest was low. PMID:27076885

  18. Laboratory insights into the chemical and kinetic evolution of several organic molecules under simulated Mars surface UV radiation conditions

    NASA Astrophysics Data System (ADS)

    Poch, O.; Kaci, S.; Stalport, F.; Szopa, C.; Coll, P.

    2014-11-01

    The search for organic carbon at the surface of Mars, as clues of past habitability or remnants of life, is a major science goal of Mars' exploration. Understanding the chemical evolution of organic molecules under current martian environmental conditions is essential to support the analyses performed in situ. What molecule can be preserved? What is the timescale of organic evolution at the surface? This paper presents the results of laboratory investigations dedicated to monitor the evolution of organic molecules when submitted to simulated Mars surface ultraviolet radiation (190-400 nm), mean temperature (218 ± 2 K) and pressure (6 ± 1 mbar) conditions. Experiments are done with the MOMIE simulation setup (for Mars Organic Molecules Irradiation and Evolution) allowing both a qualitative and quantitative characterization of the evolution the tested molecules undergo (Poch, O. et al. [2013]. Planet. Space Sci. 85, 188-197). The chemical structures of the solid products and the kinetic parameters of the photoreaction (photolysis rate, half-life and quantum efficiency of photodecomposition) are determined for glycine, urea, adenine and chrysene. Mellitic trianhydride is also studied in order to complete a previous study done with mellitic acid (Stalport, F., Coll, P., Szopa, C., Raulin, F. [2009]. Astrobiology 9, 543-549), by studying the evolution of mellitic trianhydride. The results show that solid layers of the studied molecules have half-lives of 10-103 h at the surface of Mars, when exposed directly to martian UV radiation. However, organic layers having aromatic moieties and reactive chemical groups, as adenine and mellitic acid, lead to the formation of photoresistant solid residues, probably of macromolecular nature, which could exhibit a longer photostability. Such solid organic layers are found in micrometeorites or could have been formed endogenously on Mars. Finally, the quantum efficiencies of photodecomposition at wavelengths from 200 to 250 nm

  19. Testing Insecticidal Activity of Novel Chemically Synthesized siRNA against Plutella xylostella under Laboratory and Field Conditions

    PubMed Central

    Gong, Liang; Chen, Yong; Hu, Zhen; Hu, Meiying

    2013-01-01

    Background Over the last 60 years, synthetic chemical pesticides have served as a main tactic in the field of crop protection, but their availability is now declining as a result of the development of insect resistance. Therefore, alternative pest management agents are needed. However, the demonstration of RNAi gene silencing in insects and its successful usage in disrupting the expression of vital genes opened a door to the development of a variety of novel, environmentally sound approaches for insect pest management. Methodology/Principal Findings Six small interfering RNAs (siRNAs) were chemically synthesized and modified according to the cDNA sequence of P. xylostella acetylcholine esterase genes AChE1 and AChE2. All of them were formulated and used in insecticide activity screening against P. xylostella. Bioassay data suggested that Si-ace1_003 and Si-ace2_001 at a concentration of 3 µg cm−2 displayed the best insecticidal activity with 73.7% and 89.0%, mortality, respectively. Additional bioassays were used to obtain the acute lethal concentrations of LC50 and LC90 for Si-ace2_001, which were 53.66 µg/ml and 759.71 µg/ml, respectively. Quantitative Real-time PCR was used to confirm silencing and detected that the transcript levels of P. xylostella AChE2 (PxAChE2) were reduced by 5.7-fold compared to the control group. Consequently, AChE activity was also reduced by 1.7-fold. Finally, effects of the siRNAs on treated plants of Brassica oleracea and Brassica alboglabra were investigated with different siRNA doses. Our results showed that Si-ace2_001 had no negative effects on plant morphology, color and growth of vein under our experimental conditions. Conclusions The most important finding of this study is the discovery that chemically synthesized and modified siRNA corresponding to P. xylostella AChE genes cause significant mortality of the insect both under laboratory and field conditions, which provides a novel strategy to control P. xylostella and to

  20. Final Report - Phase II - Biogeochemistry of Uranium Under Reducing and Re-oxidizing Conditions: An Integrated Laboratory and Field Study

    SciTech Connect

    Peyton, Brent; Sani, Rajesh

    2006-09-28

    Our understanding of subsurface microbiology is hindered by the inaccessibility of this environment, particularly when the hydrogeologic medium is contaminated with toxic substances. Past research in our labs indicated that the composition of the growth medium (e.g., bicarbonate complexation of U(VI)) and the underlying mineral phase (e.g., hematite) significantly affects the rate and extent of U(VI) reduction and immobilization through a variety of effects. Our research was aimed at elucidating those effects to a much greater extent, while exploring the potential for U(IV) reoxidation and subsequent re-mobilization, which also appears to depend on the mineral phases present in the system. The project reported on here was an extension ($20,575) of the prior (much larger) project. This report is focused only on the work completed during the extension period. Further information on the larger impacts of our research, including 28 publications, can be found in the final report for the following projects: 1) Biogeochemistry of Uranium Under Reducing and Re-oxidizing Conditions: An Integrated Laboratory and Field Study Grant # DE-FG03-01ER63270, and 2) Acceptable Endpoints for Metals and Radionuclides: Quantifying the Stability of Uranium and Lead Immobilized Under Sulfate Reducing Conditions Grant # DE-FG03-98ER62630/A001 In this Phase II project, the toxic effects of uranium(VI) were studied using Desulfovibrio desulfuricans G20 in a medium containing bicarbonate or 1, 4-piperazinediethane sulfonic acid disodium salt monohydrate (PIPES) buffer (each at 30 mM, pH 7). The toxicity of uranium(VI) was dependent on the medium buffer and was observed in terms of longer lag times and in some cases, no measurable growth. The minimum inhibiting concentration (MIC) was 140 M U(VI) in PIPES buffered medium. This is 36 times lower than previously reported for D. desulfuricans. These results suggest that U(VI) toxicity and the detoxification mechanisms of G20 depend greatly on the

  1. Matrix diffusion and sorption of Cs+, Na+, I- and HTO in granodiorite: Laboratory-scale results and their extrapolation to the in situ condition.

    PubMed

    Tachi, Yukio; Ebina, Takanori; Takeda, Chizuko; Saito, Toshihiko; Takahashi, Hiroaki; Ohuchi, Yuji; Martin, Andrew James

    2015-08-01

    Matrix diffusion and sorption are important processes controlling radionuclide transport in crystalline rocks. Such processes are typically studied in the laboratory using borehole core samples however there is still much uncertainty on the changes to rock transport properties during coring and decompression. It is therefore important to show how such laboratory-based results compare with in situ conditions. This paper focuses on laboratory-scale mechanistic understanding and how this can be extrapolated to in situ conditions as part of the Long Term Diffusion (LTD) project at the Grimsel Test Site, Switzerland. Diffusion and sorption of (137)Cs(+), (22)Na(+), (125)I(-) and tritiated water (HTO) in Grimsel granodiorite were studied using through-diffusion and batch sorption experiments. Effective diffusivities (De) of these tracers showed typical cation excess and anion exclusion effects and their salinity dependence, although the extent of these effects varied due to the heterogeneous pore networks in the crystalline rock samples. Rock capacity factors (α) and distribution coefficients (Kd) for Cs(+) and Na(+) were found to be sensitive to porewater salinity. Through-diffusion experiments indicated dual depth profiles for Cs(+) and Na(+) which could be explained by a near-surface Kd increment. A microscopic analysis indicated that this is caused by high porosity and sorption capacities in disturbed biotite minerals on the surface of the samples. The Kd values derived from the dual profiles are likely to correspond to Kd dependence on the grain sizes of crushed samples in the batch sorption experiments. The results of the in situ LTD experiments were interpreted reasonably well by using transport parameters derived from laboratory data and extrapolating them to in situ conditions. These comparative experimental and modelling studies provided a way to extrapolate from laboratory scale to in situ condition. It is well known that the difference in porosity between

  2. Under What Conditions Does Caseworker-Caregiver Racial/Ethnic Similarity Matter for Housing Service Provision? An Application of Representative Bureaucracy Theory.

    PubMed

    McBeath, Bowen; Chuang, Emmeline; Bunger, Alicia; Blakeslee, Jennifer

    2014-03-01

    In this article, we examine child welfare caseworkers' housing-related service strategies when they serve culturally similar versus culturally dissimilar clients. Testing hypotheses drawn from representative bureaucracy theory and using data from the second cohort of the National Survey of Child and Adolescent Well-Being, we find that when non-Caucasian caseworkers share the same racial/ethnic background as caregivers, caseworkers use more active strategies to connect caregivers to needed housing services. The relationship between racial/ethnic matching and frontline workers' repertoire of service strategies is most pronounced when the need for housing has been registered formally via referrals and case plans and thus legitimated institutionally. These results reinforce basic tenets of representative bureaucracy theory and provide evidence of the benefits of racial and ethnic diversity in the human service workforce. Our findings also highlight the need for research identifying institutional and frontline organizational factors that enhance the quality of service provision.

  3. Chemical Evolution of Organic Molecules Under Mars-Like UV Radiation Conditions Simulated in the Laboratory with the MOMIE Setup

    NASA Astrophysics Data System (ADS)

    Poch, O.; Coll, P.; Szopa, C.; Stalport, F.; Georgelin, T.; Jaber, M.; Lambert, J.-F.

    2014-07-01

    Results of laboratory simulations aiming to explain the evolution of organic molecules at the surface of Mars, to support the search for organics conducted in situ. What molecule can be preserved? Within which timescale? What is the effect of clays?

  4. Reproductive Patterns of Xylotrechus arvicola (Coleoptera: Cerambycidae), an Emerging Pest of Grape-Vines, under Laboratory Conditions.

    PubMed

    Rodríguez-González, Álvaro; Peláez, Horacio J; González-López, Óscar; Mayo, Sara; Casquero, Pedro A

    2016-03-25

    Xylotrechus arvicola(Olivier) is an emerging pest in vineyards (Vitis vinifera) in the Iberian Peninsula. Its reproductive biology has been studied in the laboratory in order to develop pest-control measures. Obtained results show that the oviposition period is significantly longer in wild females (16.6 ± 2.9 d) than in laboratory females (9.7 ± 1.3 d), but there are no significant differences in the egg-hatching periods between the wild and the laboratory females. Fecundity is significantly higher in laboratory females (93.9 ± 12.1 eggs per female) than in wild females (56.8 ± 9.2 eggs per female). On the other hand, viability (percentage of viable eggs per female) is significantly higher in wild females (53.7 ± 6.6%) than in laboratory females (22.9 ± 3.6%). Wild females lay fewer eggs over a longer period, while laboratory females concentrate on laying in the first 6 d.X. arvicolafemales (wild and laboratory) lay the highest number of eggs on the sixth day. The fecundity and viability of eggs are extended over a longer period in wild females than in laboratory females. SoX. arvicolais a species in which larvae feed directly affects reproductive patterns. These results suggest that, when larvae feed directly from the natural host, the fecundity period and the viability of eggs increase. So the selection of a host plant could be influenced by the composition of the wood. This behavior of the species can also help to advance knowledge of the biology and ecology of this pest, to be applied in integrated control.

  5. YUCCA Mountain Project - Argonne National Laboratory, Annual Progress Report, FY 1997 for activity WP 1221 unsaturated drip condition testing of spent fuel and unsaturated dissolution tests of glass.

    SciTech Connect

    Bates, J. K.; Buck, E. C.; Emery, J. W.; Finch, R. J.; Finn, P. A.; Fortner, J.; Hoh, J. C.; Mertz, C.; Neimark, L. A.; Wolf, S. F.; Wronkiewicz, D. J.

    1998-09-18

    This document reports on the work done by the Nuclear Waste Management Section of the Chemical Technology Division of Argonne National Laboratory in the period of October 1996 through September 1997. Studies have been performed to evaluate the behavior of nuclear waste glass and spent fuel samples under the unsaturated conditions (low-volume water contact) that are likely to exist in the Yucca Mountain environment being considered as a potential site for a high-level waste repository. Tests with actinide-doped waste glasses, in progress for over 11 years, indicate that the transuranic element release is dominated by colloids that continuously form and span from the glass surface. The nature of the colloids that form in the glass and spent fuel testing programs is being investigated by dynamic light scattering to determine the size distribution, by autoradiography to determine the chemistry, and by zeta potential to measure the electrical properties of the colloids. Tests with UO{sub 2} have been ongoing for 12 years. They show that the oxidation of UO{sub 2} occurs rapidly, and the resulting paragenetic sequence of secondary phases forming on the sample surface is similar to that observed for uranium found in natural oxidizing environments. The reaction of spent fuel samples in conditions similar to those used with UO{sub 2} have been in progress for over six years, and the results suggest that spent fuel forms many of the same alteration products as UO{sub 2}. With spent fuel, the bulk of the reaction occurs via a through-grain reaction process, although grain boundary attack is sufficient to have reacted all of the grain boundary regions in the samples. New test methods are under development to evaluate the behavior of spent fuel samples with intact cladding: the rate at which alteration and radionuclide release occurs when water penetrates fuel sections and whether the reaction causes the cladding to split. Alteration phases have been formed on fine grains of UO

  6. Effects of Beauveria bassiana on survival, blood-feeding success, and fecundity of Aedes aegypti in laboratory and semi-field conditions.

    PubMed

    Darbro, Jonathan M; Johnson, Petrina H; Thomas, Matthew B; Ritchie, Scott A; Kay, Brian H; Ryan, Peter A

    2012-04-01

    The fungus Beauveria bassiana reduces Aedes aegypti longevity in laboratory conditions, but effects on survival, blood-feeding behavior, and fecundity in realistic environmental conditions have not been tested. Adult, female Ae. aegypti infected with B. bassiana (FI-277) were monitored for blood-feeding success and fecundity in the laboratory. Fungal infection reduced mosquito-human contact by 30%. Fecundity was reduced by (mean ± SD) 29.3 ± 8.6 eggs per female per lifetime in the laboratory; egg batch size and viability were unaffected. Mosquito survival, blood-feeding behavior, and fecundity were also tested in 5 meter × 7 meter × 4 meter semi-field cages in northern Queensland, Australia. Fungal infection reduced mosquito survival in semi-field conditions by 59-95% in large cages compared with 61-69% in small cages. One semi-field cage trial demonstrated 80% reduction in blood-feeding; a second trial showed no significant effect. Infection did not affect fecundity in large cages. Beauveria bassiana can kill and may reduce biting of Ae. aegypti in semi-field conditions and in the laboratory. These results further support the use of B. bassiana as a potential biocontrol agent against Ae. aegypti.

  7. Two initial vaccinations with the Bm86-based Gavacplus vaccine against Rhipicephalus (Boophilus) microplus induce similar reproductive suppression to three initial vaccinations under production conditions

    PubMed Central

    2010-01-01

    Background The cattle tick, Rhipicephalus (Boophilus) microplus, affects livestock production in many regions of the world. Up to now, the widespread use of chemical acaricides has led to the selection of acaricide-resistant ticks and to environmental contamination. Gavacplus is a subunit vaccine based on the recombinant Bm86 tick antigen expressed in yeast, capable to control infestations of R. microplus under controlled and production conditions. The vaccine constitutes the core element of broad control programs against this ectoparasite, in which acquired immunity in cattle to Bm86 is combined with a rational use of acaricides. At present, the conventional vaccine scheme consists of three doses that should be administered at weeks 0, 4 and 7, followed by a booster every six months. Results In this study we assayed a reduction in the number of the initial doses of Gavacplus, evaluated the time course and the level of bovine anti-Bm86 antibodies elicited, and analyzed the vaccine effect on ticks engorging on immunized cattle under production conditions. Following three different immunization schemes, the bovines developed a strong and specific immune response characterized by elevated anti-Bm86 IgG titers. A reduction in the weight of engorging female ticks, in the weight of the eggs laid and also in R. microplus viable eggs percentage was obtained by using only two doses of Gavacplus administered at weeks 0 and 4, followed by a booster six months later. This reduction did not differ from the results obtained on ticks engorging on cattle immunized at weeks 0, 4 and 7. It was also demonstrated that anti-Bm86 antibody titers over 1:640, measured in bovines immunized at weeks 0 and 4, were sufficient to affect weight and reproductive potential of female ticks as compared with ticks engorging on unvaccinated animals. In addition, no statistically significant differences were detected in the average weight of eggs laid by ticks engorged on immunized cattle that showed

  8. A review of hydrologic and geologic conditions related to the radioactive solid-waste burial grounds at Oak Ridge National Laboratory, Tennessee

    USGS Publications Warehouse

    Webster, D.A.

    1976-01-01

    Solid waste contaminated by radioactive matter has been buried in the vicinity of Oak Ridge National Laboratory since 1944. By 1973, an estimated six million cubic feet of such material had been placed in six burial grounds in two valleys. The practice initially was thought of as a safe method for permanently removing these potentially hazardous substances from man's surroundings, but is now que.3tionable at this site because of known leaching of contaminants from the waste, transport in ground water, and release to the terrestrial and fluvial environments. This review attempts to bring together in a single document information from numerous published and unpublished sources regarding the past criteria used for selecting the Oak Ridge burial-ground sites, the historical development and conditions of these facilities as of 1974, the geologic framework of the Laboratory area and the movement of water and water-borne contaminants in that area, the effects of sorption and ion exchange upon radionuclide transport, and a description and evaluation of the existing monitoring system. It is intended to assist Atomic Energy Commission (now Energy Research and Development Administration) officials in the formulation of managerial decisions concerning the burial grounds and present monitoring methods. Sites for the first three burial grounds appear to have been chosen during and shortly after World War II on the basis of such factors as safety, security, and distance from sources of waste origin. By 1950, geologic criteria had been introduced, and in the latter part of that decade, geohydrologic criteria were considered. While no current criteria have been defined, it becomes evident from the historical record that the successful containment of radionuclides below land surface for long periods of time is dependent upon a complex interrelationship between many geologic, hydrologic, and geochemical controls, and any definition of criteria must include consideration of these

  9. Measurement of copper release rates from antifouling paint under laboratory and in situ conditions: implications for loading estimation to marine water bodies.

    PubMed

    Valkirs, Aldis O; Seligman, Peter F; Haslbeck, Elizabeth; Caso, Joaquin S

    2003-06-01

    The release of biocides, such as copper (Cu), from antifouling (AF) coatings on vessel hulls represents a significant proportion of overall Cu loading in those harbors and estuaries where substantial numbers of small craft or large vessels are berthed. Copper release rates were measured on several self-polishing, tin-free coatings and an ablative Cu reference coating applied to steel panels using three measurement methods. The panels were exposed in natural seawater in San Diego Bay, and release rates were measured both in the laboratory and field over 2 years. Results with the static (20 cm x 30 cm) panels indicated that Cu release rates were initially high (25-65 microg Cu cm(-2)day(-1)), with a large range of values between paint types. Release rates declined to substantially lower rates (8-22 microg cm(-2)day(-1)) with reduced variability within 2 months. Release rates continued to decrease over time for approximately 6 months when relatively constant release rates were observed for most coatings. Over time, relative differences in Cu release rates measured by three exposure methods decreased, with all coatings exhibiting similar behavior toward the end of the study. Lowest overall Cu release rates were observed with the self-polishing experimental paint no. 7 in static-dynamic and in situ treatments. The highest periodic release rates were measured from panels that experienced periods of both static and dynamic exposure (8.7 ms(-1) rotation). The lowest release rates were measured from panels that experienced static, constant depth exposure, and where release rates were evaluated in situ, using a novel diver-deployed measurement system. Results from this in situ technique suggests that it more closely reflects actual Cu release rates on vessel hulls measured with intact natural biofilms under ambient conditions than measurements using standardized laboratory release rate methods. In situ measurements made directly on the AF surface of vessels demonstrated

  10. Repellency of a kaolin particle film to potato payllid, Bactericera cockerelli (Hemiptera: Psyllidae) on tomato under laboratory and field conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The potato psyllid, Bactericera cockerelli, is a vector of “Candidatus Liberibacter solanacearum,” the bacterium causing several diseases in solanaceous crops. Laboratory and field no-choice and choice experiments were conducted to evaluate repellency of kaolin particle film on adults of B. cockerel...

  11. A Laboratory Exercise to Illustrate Increased Salivary Cortisol in Response to Three Stressful Conditions Using Competitive ELISA

    ERIC Educational Resources Information Center

    Haussmann, Mark F.; Vleck, Carol M; Farrar, Eugenia S.

    2007-01-01

    Perceived stress activates the hypothalamus-pituitary-adrenal axis, resulting in the release of glucocorticoids into the systemic circulation. Glucocorticoids cause the elevation of blood glucose, providing the necessary energy for the organism to cope with stress. Here, we outline a laboratory exercise that uses a competitive ELISA kit to…

  12. Effectiveness and residual activity comparison of granular formulations of insect growth regulators pyriproxyfen and s-methoprene against Florida mosquitoes in laboratory and outdoor conditions.

    PubMed

    Nayar, Jai K; Ali, Arshad; Zaim, Morteza

    2002-09-01

    Effectiveness and residual activity tests of granular formulations of 2 insect growth regulators (IGRs), s-methoprene and pyriproxyfen, against laboratory-reared larvae of 5 colonized mosquitoes, Aedes aegypti, Aedes albopictus, Aedes taeniorhynchus, Anopheles quadrimaculatus, and Culex nigripalpus, were conducted in the laboratory and outdoors in plastic tubs. Culex quinquefasciatus was exposed to these two IGRs in the laboratory only. Each IGR formulation was applied at 0.02 and 0.05 ppm active ingredient (Al) against 5 of the 6 mosquito species both in the laboratory and the outdoor evaluations, whereas Cx. quinquefasciatus was exposed to 0.2 and 0.4 ppm AI of s-methoprene, and 0.1 and 0.2 ppm AI of pyriproxyfen in the laboratory. s-Methoprene at 0.02 and 0.05 ppm AI resulted in variable levels (<39-100%) of inhibition of adult emergence in the 5 species monitored for 6 weeks after treatment under both test conditions. Aedes taeniorhynchus was the most susceptible to s-methoprene in terms of initial and residual activity. Culex quinquefasciatus and Ae. albopictus were the most tolerant to s-methopene, with maximum emergence inhibitions amounting to 84% in Cx. quinquefasciatus at 0.4 ppm and 44.3% in Ae. albopictus at 0.05 ppm during the 1st week in the laboratory. Pyriproxyfen at comparable treatment rates to s-methoprene caused very high levels (>80-100% in most cases) of initial and residual emergence inhibitions of the tested species in the laboratory as well as outdoors. In several species, pyriproxyfen induced complete inhibition of adult emergence for several weeks after treatment, even at the lower rate of 0.02 ppm. The World Health Organization has recently recommended the use of pyriproxyfen for the control of some mosquito species at specified rates in certain habitats.

  13. Evaluation of a bioluminescence method, contact angle measurements and topography for testing the cleanability of plastic surfaces under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Redsven, I.; Kymäläinen, H.-R.; Pesonen-Leinonen, E.; Kuisma, R.; Ojala-Paloposki, T.; Hautala, M.; Sjöberg, A.-M.

    2007-04-01

    Detection of adenosine triphosphate (ATP) by bioluminescence is used, for instance, in the food industry and in hospitals to assess the hygiene status of surfaces. The aim of this laboratory study was to investigate the feasibility of the ATP method for estimating the cleanability of resilient floor coverings from biological soil. The surfaces were worn using a Soiling and Wearing Drum Tester, and soiled and cleaned with an Erichsen Washability and Scrubbing Resistance Tester. In the laboratory test carried out with the bioluminescence method, most of the new and worn floor coverings that were biologically soiled were cleaned efficiently. According to this study, the semiquantitative ATP screening method can be used for hygiene monitoring of flooring materials. No correlation was found between cleanability and contact angles or surface topography measured using a profilometer. However, by revealing local irregularities and damage on surfaces, scanning electron micrographs appeared useful in explaining differences in cleanability.

  14. Flue gas conditioning for improved particle collection in electrostatic precipitators. First topical report, Results of laboratory screening of additives

    SciTech Connect

    Durham, M.D.

    1993-04-16

    Several tasks have been completed in a program to evaluate additives to improve fine particle collection in electrostatic precipitators. Screening tests and laboratory evaluations of additives are summarized in this report. Over 20 additives were evaluated; four were found to improve flyash precipitation rates. The Insitec particle analyzer was also evaluated; test results show that the analyzer will provide accurate sizing and counting information for particles in the size range of {le} 10 {mu}m dia.

  15. Characterisation of the biosand filter for E. coli reductions from household drinking water under controlled laboratory and field use conditions.

    PubMed

    Stauber, C E; Elliott, M A; Koksal, F; Ortiz, G M; DiGiano, F A; Sobsey, M D

    2006-01-01

    More than a billion people in the developing world lack access to safe and reliable sources of drinking water. Point of use (POU) household water treatment technology allows people to improve the quality of their water by treating it in the home. One emerging POU technology is the biosand filter (BSF), a household-scale, intermittently operated slow sand filter. Laboratory and field studies examined Escherichia coli reductions achieved by the BSF. During two laboratory studies, mean E. coli reductions were 94% and they improved over the period of filter use, reaching a maximum of 99%. Field analysis conducted on 55 household filters near Bonao, Dominican Republic averaged E. coli reductions of 93%. E. coli reductions by the BSF in laboratory and field studies were less than those typically observed for traditional slow sand filters (SSFs), although as for SSFs microbial reductions improved over the period of filter use. Further study is needed to determine the factors contributing to microbial reductions in BSFs and why reductions are lower than those of conventional SSFs.

  16. Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions

    NASA Technical Reports Server (NTRS)

    Gandin, Charles-Andre; Ratke, Lorenz

    2008-01-01

    The Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MSL-CETSOL and MICAST) are two investigations which supports research into metallurgical solidification, semiconductor crystal growth (Bridgman and zone melting), and measurement of thermo-physical properties of materials. This is a cooperative investigation with the European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) for accommodation and operation aboard the International Space Station (ISS). Research Summary: Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing (CETSOL) and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST) are two complementary investigations which will examine different growth patterns and evolution of microstructures during crystallization of metallic alloys in microgravity. The aim of these experiments is to deepen the quantitative understanding of the physical principles that govern solidification processes in cast alloys by directional solidification.

  17. [The opportunity to use combined stem cells transplantation for haemopoesis activation in the old and mature laboratory animals under the conditions of ionizing radiation].

    PubMed

    Grebnev, D U

    2014-01-01

    The objective of this work was to study the influence of combined transplantation of stem cells (multypotent mesenchimal stromal and hem poetic stem cells) on the haemopoesis of old and mature laboratory animals under the condition of ionizing radiation. The experiments were conducted on 48 white male mice with the body weight of 30 g, age of 3-4 months, and 48 male mice of 3 years of age and body mass of 50 g. The experiments for obtaining the MMSC and HSC cultures were conducted on 16 laboratory animals: female mice of 3-4 months of age and body mass of 30 g., 18 days gestation period. The control group was formed by the animals not under the ionizing radiation. The experimental group animals got the dose of 4 Gr. These animals also got MMSC and HSC mixture intravenously in the doses of 6 mln. c/kg. and 330 thousand cell/kg prospectively. The control group animals got the 0.9% NaCl - 0.2 ml. intravenously. The infusions were made 1 hour after radiation once. As the result of the experiment it was shown that under physiological conditions combined transplantation brings the erithropoesis activation, under the ionizing radiation conditions it brings the erythroid and granulocytopoesis activation. More over the combined MMSC and HSC transplantation gives cytoprotective action on the myeloid tissue due to decrease of cyto genically changed cells in the mature animals under the condition of ionizing radiation, but in the old animals this effect can be seen even under physiological condition. Conclusions: Combined transplantation of MMSC and GSC can be used in the mature and old laboratory animals under the conditions of ionising radiation for the haemopoesis activation.

  18. Effects of azadirachtin, abamectin, and spinosad on sweetpotato whitefly (Homoptera: Aleyrodidae) on tomato plants under laboratory and greenhouse conditions in the humid tropics.

    PubMed

    Kumar, Prabhat; Poehling, H M

    2007-04-01

    Direct and residual toxicity of NeemAzal-T/S (azadirachtin), Success (spinosad), and abamectin was tested against different life stages of sweetpotato whitefly, Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), under air-conditioned laboratory conditions and in a tropical net greenhouse. NeemAzal-T/S and abamectin deterred the settling of adults on tomato, Lycopersicon esculentum Mill (Solanaceae), plants and consequently reduced egg deposition. No such effect was detected for Success. All three pesticides influenced egg hatch. Effects of NeemAzal-T/ S were significantly altered if applied to different-aged eggs (1, 3, and 5 d old). In contrast, abamectin-treated eggs failed to hatch at any given age class. All three products caused heavy mortality of the three nymphal stages of B. tabaci, with the first instars being most susceptible, abamectin-treated nymphs died within 24 h postapplication. In contrast, 100% nymphal mortality with NeemAzal-T/S and Success was reached 6-9 d postapplication. abamectin caused 100% immature mortality at all residue ages (1, 5, 10, and 15 d) in the laboratory and greenhouse as well. Persistence of Success was comparably high in the laboratory, but in the greenhouse a faster decline of activity was evident by increased egg deposition, egg hatch, and reduced rates of immature mortality. Toxicity of NeemAzal-T/S however gradually declined under greenhouse conditions with time (5 d) postapplication. The findings are discussed within the context of integrated management of whitefly under protected cultivation in the humid tropics.

  19. Dynamic similarity in erosional processes

    USGS Publications Warehouse

    Scheidegger, A.E.

    1963-01-01

    A study is made of the dynamic similarity conditions obtaining in a variety of erosional processes. The pertinent equations for each type of process are written in dimensionless form; the similarity conditions can then easily be deduced. The processes treated are: raindrop action, slope evolution and river erosion. ?? 1963 Istituto Geofisico Italiano.

  20. ENHANCED THERMAL VACUUM TEST CAPABILITY FOR RADIOISOTOPE POWER SYSTEMS AT THE IDAHO NATIONAL LABORATORY BETTER SIMULATES ENVIRONMENTAL CONDITIONS OF SPACE

    SciTech Connect

    J. C. Giglio; A. A. Jackson

    2012-03-01

    The Idaho National Laboratory (INL) is preparing to fuel and test the Advanced Stirling Radioisotope Generator (ASRG), the next generation space power generator. The INL identified the thermal vacuum test chamber used to test past generators as inadequate. A second vacuum chamber was upgraded with a thermal shroud to process the unique needs and to test the full power capability of the new generator. The thermal vacuum test chamber is the first of its kind capable of testing a fueled power system to temperature that accurately simulate space. This paper outlines the new test and set up capabilities at the INL.

  1. Can varying velocity conditions be one possible explanation for differences between laboratory and field observations of bacterial transport in porous media?

    NASA Astrophysics Data System (ADS)

    Liu, P. C.; Mailloux, B. J.; Wagner, A.; Magyar, J. S.; Culligan, P. J.

    2016-02-01

    Laboratory column experimental results are frequently used to estimate field-scale, fecal bacterial transport distances. However, it is not uncommon for fecal bacteria to be observed at greater distances than predicted by up-scaling laboratory results. Fluctuating or varying velocity conditions is one complex in-situ condition that might account for such inaccurate prediction, yet it is often neglected in laboratory column experiments. In this study, one-dimensional, laboratory column experiments were performed under both constant and varying velocity conditions using 2 μm microspheres and 100 μm glass beads to simulate bacterial transport in saturated porous media. Particle breakthrough curves and particle concentrations retained in the column at the end of an experiment were obtained for five constant and three varying velocity conditions. The range of constant velocities investigated was between 3.17 m/day and 27.65 m/day. For varying velocity conditions, the velocity was steadily increased and/or decreased over the period of the experiment within the same range. Results from the constant velocity experiments were successfully modeled using first order, irreversible particle attachment kinetics. The irreversible attachment coefficients obtained from the constant velocity experiments were used to derive a power function relationship between a dimensionless irreversible attachment coefficient, Ki* and velocity, v. This relationship was then used to model the varying velocity experiments, with limited success (NRMSE > 10% for all model fits). A comparison of Ki* values obtained from direct fitting of the varying velocity tests, with the Ki* values derived from the results of the constant velocity experiments, revealed a potential dependence of Ki* on the rate of change of velocity. Observed particle breakthrough curves (BTCs) for the varying velocity experiments were also modeled using a constant value of Ki* based on the average velocity of each experiment. The

  2. Population-level effects of spinosad and Bacillus thuringiensis israelensis in Daphnia pulex and Daphnia magna: comparison of laboratory and field microcosm exposure conditions.

    PubMed

    Duchet, Claire; Coutellec, Marie-Agnès; Franquet, Evelyne; Lagneau, Christophe; Lagadic, Laurent

    2010-10-01

    Because exposure to toxicants not only results in mortality but also in multiple sublethal effects, the use of life-table data appears particularly suitable to assess global effects on exposed populations. The present study uses a life table response approach to assess population-level effects of two insecticides used against mosquito larvae, spinosad (8 μg/l) and Bacillus thuringiensis var. israelensis (Bti, 0.5 μl/l), on two non target species, Daphnia pulex and Daphnia magna (Crustacea: Cladocera), under laboratory versus field microcosms conditions. Population growth rates were inferred from life table data and Leslie matrices under a model with resource limitation (ceiling). These were further used to estimate population risks of extinction under each tested condition, using stochastic simulations. In laboratory conditions, analyses performed for each species confirmed the significant negative effect of spinosad on survival, mean time at death, and fecundity as compared to controls and Bti-treated groups; for both species, population growth rate λ was lower under exposure to spinosad. In field microcosms, 2 days after larvicide application, differences in population growth rates were observed between spinosad exposure conditions, and control and Bti exposure conditions. Simulations performed on spinosad-exposed organisms led to population extinction (minimum abundance = 0, extinction risk = 1), and this was extremely rapid (time to quasi-extinction = 4.1 one-week long steps, i.e. one month). Finally, D. magna was shown to be more sensitive than D. pulex to spinosad in the laboratory, and the effects were also detectable through field population demographic simulations.

  3. A Simple and Low-Cost Monitoring System to Investigate Environmental Conditions in a Biological Research Laboratory

    PubMed Central

    Gurdita, Akshay; Vovko, Heather; Ungrin, Mark

    2016-01-01

    Basic equipment such as incubation and refrigeration systems plays a critical role in nearly all aspects of the traditional biological research laboratory. Their proper functioning is therefore essential to ensure reliable and repeatable experimental results. Despite this fact, in many academic laboratories little attention is paid to validating and monitoring their function, primarily due to the cost and/or technical complexity of available commercial solutions. We have therefore developed a simple and low-cost monitoring system that combines a “Raspberry Pi” single-board computer with USB-connected sensor interfaces to track and log parameters such as temperature and pressure, and send email alert messages as appropriate. The system is controlled by open-source software, and we have also generated scripts to automate software setup so that no background in programming is required to install and use it. We have applied it to investigate the behaviour of our own equipment, and present here the results along with the details of the monitoring system used to obtain them. PMID:26771659

  4. A Simple and Low-Cost Monitoring System to Investigate Environmental Conditions in a Biological Research Laboratory.

    PubMed

    Gurdita, Akshay; Vovko, Heather; Ungrin, Mark

    2016-01-01

    Basic equipment such as incubation and refrigeration systems plays a critical role in nearly all aspects of the traditional biological research laboratory. Their proper functioning is therefore essential to ensure reliable and repeatable experimental results. Despite this fact, in many academic laboratories little attention is paid to validating and monitoring their function, primarily due to the cost and/or technical complexity of available commercial solutions. We have therefore developed a simple and low-cost monitoring system that combines a "Raspberry Pi" single-board computer with USB-connected sensor interfaces to track and log parameters such as temperature and pressure, and send email alert messages as appropriate. The system is controlled by open-source software, and we have also generated scripts to automate software setup so that no background in programming is required to install and use it. We have applied it to investigate the behaviour of our own equipment, and present here the results along with the details of the monitoring system used to obtain them.

  5. Soil structure, colloids, and chemical transport as affected by short-term reducing conditions: a laboratory study

    NASA Astrophysics Data System (ADS)

    de-Campos, A. B.; Mamedov, A. I.; Huang, C.; Wagner, L. E.

    2008-12-01

    Upland soils in the Midwestern US often undergo reducing conditions when soils are temporally flooded during the spring and remain water saturated for days or weeks. Short-term reducing conditions change the chemistry of the soil and may affect soil structure and solution chemical transport. The effects of short-term reducing conditions on chemical and physical properties of the soils, colloids, and associated chemical/nutrients transport are still not well understood and was the objective of our study. A biogeochemical reactor was built to achieve reducing conditions. Three cultivated and three uncultivated soils with different organic carbon contents were incubated in the reactor for 1 hour and 3 days under anaerobic conditions. Effects of the redox state on soil structure (pore size distribution) and drainable porosity, colloids mobility, and chemical transport were determined using high energy moisture characteristic and analytical methods. After each treatment, the soil solution was collected for redox potential (Eh), pH, and electrical conductivity (EC) measurements, and chemical analysis of metals (Ca, Mg, K), nutrients (N, P), and dissolved organic carbon. Strongly reducing conditions were achieved after 3 days of incubation and were followed by a decrease in soil porosity and an increase in pH, EC, clay dispersion, swelling, colloids mobility, and associated chemical transport. The trend for each soil depended on their initial structural stability and chemical properties. The structure of cultivated soils and the leaching of nutrients and carbon from uncultivated soils were more sensitive to the redox state. A strong correlation was found between changes in Eh and drainable porosity. The role of short-term reducing conditions on changes in redox sensitive elements, organic matter decomposition, pH, and EC and their influence on soil structure and soil particles or colloids/chemical transport for both soil groups are discussed in the paper. This study

  6. Bilateral psoas abscess caused by Janibacter terrae, an unusual condition and organism resulting in laboratory and management conundrums.

    PubMed

    Wan, Wei Yee; Mughal, Ahsan; Ward, Kelly

    2016-10-19

    Psoas abscess is commonly regarded as an unusual cause for back pains and usually associated with significant risk factors or co-morbidities. We describe the clinical presentation and findings of a young male Caucasian with bilateral psoas abscesses caused by an unusual organism, Janibacter terrae (an environmental organism) not previously described in literature and the challenges faced in managing this infection. There are very few case reports of this organism causing opportunistic infections, all reported bacteraemia mainly in patients with significant co-morbidities. This case highlights the importance of psoas abscess as a differential diagnosis in patients presenting with back pain and the potential for this organism to cause abscesses in healthy individuals which was difficult to identify using conventional laboratory methods. Management of this infection was challenging and there is limited experience with antimicrobial treatment for this organism.

  7. The effects of the duration of adaptation to laboratory conditions on the formation of a passive avoidance reflex in rats.

    PubMed

    Loskutova, L V; Dubrovina, N I

    2004-02-01

    The level of adaptation of rats to their new living conditions was studied during formation of a passive avoidance habit using a single combination. A short acclimation period (3 days) had positive influences on the ability of rats to retain a memory trace. There was a negative correlation between step-through latency and measures of anxiety behavior in the elevated cross maze. A change in the adaptation period to nine days decreased the state of anxiety and the level of performance of the conditioned response. There were no correlations between these measures. The modulating role of the level of adaptation to living conditions, associated with different levels of anxiety, in a passive one-session avoidance learning model was assessed.

  8. Comparative biology of the tropical and temperate species of Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) under different laboratory conditions.

    PubMed

    Labruna, Marcelo B; Gerardi, Monize; Krawczak, Felipe S; Moraes-Filho, Jonas

    2017-01-01

    Recent studies have shown that the taxon Rhipicephalus sanguineus sensu lato (s.l.) is represented in Latin America by two distinct species, designated as 'tropical species' (distributed from Mexico to Brazil) and 'temperate species' (restricted to the southern cone of South America). Since both tropical and temperate species of R. sanguineus s.l. are parasites primarily of domestic dogs, the reasons for their distinct geographical distribution in South America could be related to particular requirements of abiotic conditions for off-host development. With the purpose to test this hypothesis, this study evaluated the off-host developmental stages (eggs, engorged larvae, nymphs and females) of both tick species simultaneously inside incubators with temperature and photoperiod regimens that simulated the summer and winter conditions of tropical Brazil (where the 'tropical species' occurs) and temperate Brazil (where the 'temperate species' occurs). Results showed that the temperate species had significantly higher survival rates than the tropical species, when engorged ticks (larvae, nymphs and females) and eggs were incubated at lower temperatures simulating winter seasons of many parts of the southern cone of South America, where the temperate species is known to occur. These results suggest that the absence of established populations of the tropical species in temperate areas of South America is related to the low overwinter capacity of the tropical species in those areas. Regarding the temperate species, unfed adults that molted from nymphs under summer conditions of either tropical or temperate Brazil remained dormant, at the state of behavioral diapause for at least 20 weeks. Contrastingly, when engorged nymphs of the temperate species were held at winter conditions for at least 3 months, and then transferred to summer conditions to complete molting, no diapause was observed in adult ticks. These results were corroborated by infestation trials, which showed

  9. Liver cirrhosis as a predisposing condition for Legionnaires' disease: a report of four laboratory-confirmed cases from China.

    PubMed

    Qin, Tian; Xia, Jie; Ren, Hongyu; Zhou, Haijian; Tang, Bo; Shao, Zhujun

    2012-07-01

    Here, we describe four cases of laboratory-confirmed Legionella infection. Case 1 was a culture-confirmed case of Legionella infection in a patient with liver cirrhosis. Following this, three other liver cirrhosis cases (cases 2-4) were diagnosed with Legionella infection as confirmed by quantitative real-time PCR. The cause of the pneumonia was determined as Legionella pneumophila by positive direct fluorescence assay and isolation of the causative agent. The infections were successfully treated by administering appropriate antibiotics. These cases highlight the importance of considering Legionella as a cause of pneumonia in patients with liver disease and lung infections. The strain of L. pneumophila isolated from Case 1 was characterized as being closely related to strain Philadelphila-1 (ATCC 33152(T)), which is the type strain of the species, belonging to serogroup 1 and sequence type 36 (ST36), and is known to be distributed worldwide. To our knowledge, this is the first report of Legionella infection on the Chinese mainland for a decade and highlights the need to raise awareness of diagnostic methods for Legionnaires' disease in China and the requirement for further epidemiological surveillance strategies to monitor this disease.

  10. Laboratory Study of Chemical Speciation of Mercury in Lake Sediment and Water under Aerobic and Anaerobic Conditions

    PubMed Central

    Regnell, Olof; Tunlid, Anders

    1991-01-01

    Chemical speciation and partitioning of radiolabeled HgCl2 were studied in model aquatic systems consisting of undisturbed eutrophic lake sediment and water in plastic cylinders. The cylinders were either gradually made anaerobic by a gentle flow of N2-CO2 or kept aerobic by air flow. The proportion of methylated 203Hg was significantly higher, in both water and sediment, in the anaerobic systems than in the aerobic systems. The composition and total concentration of fatty acids originating from bacterial phospholipids, as well as the concentration of vitamin B12, including related cobalamins, were similar in sediments from the anaerobic and aerobic systems. Bacterial cell numbers were, on average, 3.6 times higher in the anaerobic water columns than in the aerobic ones. Volatilization of 203Hg occurred in all systems except in an autoclaved control and was of similar magnitudes in the anaerobic and aerobic systems. Incorporation of 203Hg into the sediment was significantly faster in the aerobic systems than in the anaerobic systems. These results suggest that episodes of anoxia in bottom waters and sediment cause an increase in net mercury methylation and, hence, an increase in bioavailable mercury. PMID:16348444

  11. Design and laboratory testing of a chamber device to measure total flux of volatile organic compounds from the unsaturated zone under natural conditions

    NASA Astrophysics Data System (ADS)

    Tillman, Fred D.; Smith, James A.

    2004-11-01

    To determine if an aquifer contaminated with volatile organic compounds (VOCs) has potential for natural remediation, all natural processes affecting the fate and transport of VOCs in the subsurface must be identified and quantified. This research addresses the quantification of air-phase volatile organic compounds (VOCs) leaving the unsaturated zone soil gas and entering the atmosphere—including the additional flux provided by advective soil-gas movement induced by barometric pumping. A simple and easy-to-use device for measuring VOC flux under natural conditions is presented. The vertical flux chamber (VFC) was designed using numerical simulations and evaluated in the laboratory. Mass-balance numerical simulations based on continuously stirred tank reactor equations (CSTR) provided information on flux measurement performance of several sampling configurations with the final chamber configuration measuring greater than 96% of model-simulated fluxes. A laboratory device was constructed to evaluate the flux chamber under both diffusion-only and advection-plus-diffusion transport conditions. The flux chamber measured an average of 82% of 15 diffusion-only fluxes and an average of 95% of 15 additional advection-plus-diffusion flux experiments. The vertical flux chamber has the capability of providing reliable measurement of VOC flux from the unsaturated zone under both diffusion and advection transport conditions.

  12. Quantitative assessment of multi-laboratory reproducibility of SDS-PAGE assays: Digestion pattern of beta-casein and beta-lactoglobulin under simulated conditions.

    PubMed

    Defernez, Marianne; Mandalari, Giuseppina; Mills, Elizabeth Noami Clare

    2010-08-01

    A digestion protocol was applied in triplicate by ten laboratories, simulating in vivo gastric and duodenal conditions. The intra- and inter-laboratory variability in the kinetics of protein degradation was quantified, focussing on the digestion of beta-casein under gastric conditions, and of beta-lactoglobulin (beta-Lg) under duodenal conditions. The addition of surfactants such as phosphatidylcholine (PC) in the digestion mix was also evaluated. Identification and quantification of peptide bands on SDS-PAGE gels formed the basis for analysis. An average intensity loss of 69% (SD=13.5) at 5 min (89% at 10 min, with SD=5.5) was observed for beta-casein, whereas the beta-Lg duodenal digestion showed an 82% loss at 30 min (SD=14.2). Constant rates of first-order reactions showed that for fast reactions, inaccuracies in the time of first sampling contributed to the variability, which were also affected by image quality, saturation, and the splitting of time courses across gels. Breakdown products for beta-casein included ten other polypeptides, with four detected in all and two in most gels, and for beta-Lg ten polypeptides, with five detected in most, and two in two-third of the cases. Addition of PC in the gastric phase led to beta-Lg intensity loss only a quarter as large as without PC and altered beta-Lg proteolysis in the duodenal compartment.

  13. Report on Proton and Ion Beam measurements at the Matter in Extreme Condition (MCC) end station at SLAC National Accelerator Laboratory

    SciTech Connect

    Gauthier, Maxence

    2016-02-16

    We report on MeV ion beams produced with high-repetition rates of 1 Hz at the MEC end station at SLAC National Accelerator Laboratory. These data were obtained during the commissioning beam time of the new 30TW laser. After describing the experimental set-up, the laser conditions and the target diagnostics, ion beam spectra measured for different foil thicknesses and laser intensities will be presented and discussed. These results are subsequently compared with results from cryogenic hydrogen jets at MEC in January 2015.

  14. Toxicity of the herbicide glufosinate-ammonium to predatory insects and mites of Tetranychus urticae (Acari: Tetranychidae) under laboratory conditions.

    PubMed

    Ahn, Y J; Kim, Y J; Yoo, J K

    2001-02-01

    The toxicities of the herbicide glufosinate-ammonium to three predatory insect and two predatory mite species of Tetranychus urticae Koch were determined in the laboratory by the direct contact application. At a concentration of 540 ppm (a field application rate for weed control in apple orchards), glufosinate-ammonium was almost nontoxic to eggs of Amblyseius womersleyi Schicha, Phytoseiulus persimilis Athias-Henriot, and T. urticae but highly toxic to nymphs and adults of these three mite species, indicating that a common mode of action between predatory and phytophagous mites might be involved. In tests with predatory insects using 540 ppm, glufosinate-ammonium revealed little or no harm to larvae and pupae of Chrysopa pallens Rambur but was slightly harmful to eggs (71.2% mortality), nymphs (65.0% mortality), and adults (57.7% mortality) of Orius strigicollis Poppius. The herbicide showed no direct effect on eggs and adults of Harmonia axyridis (Pallas) but was harmful, slightly harmful, and harmless to first instars (100% mortality), fourth instars (51.1% mortality), and pupae (24.5% mortality), respectively. The larvae and nymphs of predators died within 12 h after treatment, suggesting that the larvicidal and nymphicidal action may be attributable to a direct effect rather than an inhibitory action of chitin synthesis. On the basis of our data, glufosinate-ammonium caused smaller effects on test predators than on T. urticae with the exception of P. persimilis, although the mechanism or cause of selectivity remains unknown. Glufosinate-ammonium merits further study as a key component of integrated pest management.

  15. Eta Carinae: An Astrophysical Laboratory to Study Conditions During the Transition Between a Pseudo-Supernova and a Supernova

    NASA Astrophysics Data System (ADS)

    McKinnon, Darren; Gull, T. R.; Madura, T.

    2014-01-01

    A major puzzle in the studies of supernovae is the pseudo-supernova, or the near-supernovae state. It has been found to precede, in timespans ranging from months to years, a number of recently-detected distant supernovae. One explanation of these systems is that a member of a massive binary underwent a near-supernova event shortly before the actual supernova phenomenon. Luckily, we have a nearby massive binary, Eta Carinae, that provides an astrophysical laboratory of a near-analog. The massive, highly-eccentric, colliding-wind binary star system survived a non-terminal stellar explosion in the 1800's, leaving behind the incredible bipolar, 10"x20" Homunculus nebula. Today, the interaction of the binary stellar winds 1") is resolvable by the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). Using HST/STIS, several three-dimensional (3D) data cubes (2D spatial, 1D velocity) have been obtained at selected phases during Eta Carinae's 5.54-year orbital cycle. The data cubes were collected by mapping the central 1-2" at 0.05" intervals with a 52"x0.1" aperture. Selected forbidden lines, that form in the colliding wind regions, provide information on electron density of the shocked regions, the ionization by the hot secondary companion of the primary wind and how these regions change with orbital phase. By applying various analysis techniques to these data cubes, we can compare and measure temporal changes due to the interactions between the two massive winds. The observations, when compared to current 3D hydrodynamic models, provide insight on Eta Carinae's recent mass-loss history, important for determining the current and future states of this likely nearby supernova progenitor.

  16. Laboratory analysis of gas hydrate cores for evaluation of reservoir conditions. For the months December 1, 1983-April 30, 1984

    SciTech Connect

    Holder, G.D.

    1984-01-01

    The object of this work is to provide technical assistance to Morgantown Energy Technology Center's effort to develop a leading program in the evaluation of hydrate samples in porous media at reservoir conditions. During the period from January to March work done on the project focused on the preparation of the heat transfer and hydrate formation data and on the writing of the previous reports. During the last two months, including April, time has been devoted to the modification of our computer program to generate hydrate stability data in the earth. In addition to this work, the effect of gas composition on dissociation enthalpy is being studied.

  17. Olive-oil mill wastewater transport under unsaturated and saturated laboratory conditions using the geoelectrical resistivity tomography method and the FEFLOW model

    NASA Astrophysics Data System (ADS)

    Seferou, P.; Soupios, P.; Kourgialas, N. N.; Dokou, Z.; Karatzas, G. P.; Candasayar, E.; Papadopoulos, N.; Dimitriou, V.; Sarris, A.; Sauter, M.

    2013-09-01

    An integrated approach for monitoring the vertical transport of a solute into the subsurface by using a geophysical method and a simulation model is proposed and evaluated. A medium-scale (1 m3) laboratory tank experiment was constructed to represent a real subsurface system, where an olive-oil mill wastewater (OOMW) spill might occur. High-resolution cross-hole electrical resistivity tomography (ERT) was performed to monitor the OOMW transport. Time-lapse ERT images defined the spatial geometry of the interface between the contaminated and uncontaminated soil into the unsaturated and saturated zones. Knowing the subsurface characteristics, the finite element flow and transport model FEFLOW was used for simulating the contaminant movement, utilizing the ERT results as a surrogate for concentration measurements for the calibration process. A statistical analysis of the ERT measurements and the corresponding transport model results for various time steps showed a good agreement between them. In addition, a sensitivity analysis of the most important parameters of the simulation model (unsaturated flow, saturated flow and transport) was performed. This laboratory-scale study emphasizes that the combined use of geophysical and transport-modeling approaches can be useful for small-scale field applications where contaminant concentration measurements are scarce, provided that its transferability from laboratory to field conditions is investigated thoroughly.

  18. The irradiating field of view of imaging laser radar under fog conditions in a controlled laboratory environment

    NASA Astrophysics Data System (ADS)

    Song, Wen-Hua; Ghassemlooy, Zabih; Lai, Jian-Cheng; Yan, Wei; Wang, Chun-Yong; Li, Zhen-Hua

    2017-04-01

    This paper theoretically and experimentally investigates the performance of the imaging laser radar (ILR) system under the fog condition. Fog is generated and controlled homogeneously within a dedicated indoor atmospheric chamber. A physical model of the reflected laser pulses due to fog and a standard Lambertian target are developed to determine the width of each echo pulse for different fog concentrations. We show that there is a good agreement between the predicted and measured results for the width of backscattered return pulses. Based on experimental results an empirical model of the horizontal and vertical irradiating field of views (FOVs) of ILR under different visibilities is also developed. Consequently, a new model is proposed to predict the horizontal and vertical irradiating FOVs of ILR by using the width of the backscattered return pulse under different fog conditions. The reported results can be used to dynamically adjust the scanning interval based on the variation of the irradiating FOVs of laser radar and improve the precision of target ranging and imaging.

  19. Role of microorganisms in emission of nitrous oxide and methane in pulse cultivated soil under laboratory incubation condition.

    PubMed

    Jena, Jyotsnarani; Ray, Sanak; Srichandan, Haragobinda; Das, Anuradha; Das, Trupti

    2013-03-01

    Soil from a pulse cultivated farmers land of Odisha, India, have been subjected to incubation studies for 40 consecutive days, to establish the impact of various nitrogenous fertilizers and water filled pore space (WFPS) on green house gas emission (N2O & CH4). C2H2 inhibition technique was followed to have a comprehensive understanding about the individual contribution of nitrifiers and denitrifiers towards the emission of N2O. Nevertheless, low concentration of C2H2 (5 ml: flow rate 0.1 kg/cm(2)) is hypothesized to partially impede the metabolic pathways of denitrifying bacterial population, thus reducing the overall N2O emission rate. Different soil parameters of the experimental soil such as moisture, total organic carbon, ammonium content and nitrate-nitrogen contents were measured at regular intervals. Application of external N-sources under different WFPS conditions revealed the diverse role played by the indigenous soil microorganism towards green house gas emission. Isolation of heterotrophic microorganisms (Pseudomonas) from the soil samples, further supported the fact that denitrification might be prevailing during specific conditions thus contributing to N2O emission. Statistical analysis showed that WFPS was the most influential parameter affecting N2O formation in soil in absence of an inhibitor like C2H2.

  20. Short-term evaluation of visible implant alpha tags in juveniles of three fish species under laboratory conditions.

    PubMed

    Turek, K C; Pegg, M A; Pope, K L

    2014-04-01

    Visible implant alpha (VI alpha) tag-induced changes in mortality and condition, as well as tag retention and readability, were examined during a 4-week period for juveniles of three fish species: tiger muskellunge Esox masquinongy × Esox lucius (91 ± 7 mm total length, L(T), mean ± s.d.), Snake River cutthroat trout Oncorhynchus clarki behnkei (84 ± 8 mm) and rainbow trout Oncorhynchus mykiss (85 ± 5 mm). Mortality and condition did not differ between tagged fish and control fish for any species and overall tag retention rates were high (92% for E. masquinongy × E. lucius, 91% for O. c. behnkei and 100% for O. mykiss). Short-term readability of VI alpha tags was low in juvenile E. masquinongy × E. lucius and juvenile O. c. behnkei. Therefore, it is not recommend to use VI alpha tags in juvenile E. masquinongy × E. lucius or juvenile O. c. behnkei for periods >2 weeks, but VI alpha tags seem to be suitable for juvenile O. mykiss for a period of at least 4 weeks.

  1. Laboratory measurements of the microwave properties of H2S under simulated Jovian conditions with an application to Neptune

    NASA Technical Reports Server (NTRS)

    Deboer, David R.; Steffes, Paul G.

    1994-01-01

    H2S opacity may significantly affect the brightness temperatures of Uranus and Neptune due to possible depletion of ammonia in the tropospheres of those planets (de Pater et al. 1991). Though the rotational line centers of H2S are in the millimeter wavelengths region, significant absorption is also present at centimeter wavelengths due to pressure broadening of the lines. Accordingly, the properties of H2S under Jovian conditions have been measured in order to constrain further the constituents' abundances on these planets. These absorptivity measurements show values that are significantly greater than values predicted by the Van Vleck-Weisskopf models traditionally used at centimeter wavelengths. In order to better model the opacity due to H2S under Jovian conditions a Ben-Reuven lineshape formalism has therefore been developed and is presented. This formalism provides a possible constraint on the relative abundances of H2S and NH3 on Neptune based on Voyager 2 radio occultation results (Lindal 1992).

  2. Effect of triflumuron, a chitin synthesis inhibitor, on Aedes aegypti, Aedes albopictus and Culex quinquefasciatus under laboratory conditions

    PubMed Central

    2013-01-01

    Background Resistance to traditional insecticides represents a threat to the control of disease vectors. The insect growth regulators (IGR) are a potential alternative to control mosquitoes, including resistant populations. The chitin synthesis inhibitors (CSI) are IGRs, which interfere with the insect molting process and represent one major class of compounds against Aedes aegypti populations resistant to the larvicide organophosphate temephos. In the present study, we evaluated the efficacy of the CSI triflumuron on Culex quinquefasciatus, Aedes albopictus and against several Ae. aegypti field populations. Methods The efficacy of triflumuron, against Cx. quinquefasciatus and Ae. albopictus was evaluated with laboratory strains through dose–response assays. Additionaly, this CSI was tested against seven Ae. aegypti field populations exhibiting distinct resistance levels to both temephos and the pyrethroid deltamethrin. Aedes aegypti populations were exposed to both a dose that inhibits 99% of the adult emergence of mosquitoes from the susceptible reference strain, Rockefeller, (EI99 = 3.95 μg/L) and the diagnostic dose (DD), corresponding to twice the EI99. Results Our results indicate that triflumuron was effective in emergence inhibition (EI) of Cx. quinquefasciatus (EI50= 5.28 μg/L; EI90= 12.47 μg/L) and Ae. albopictus (EI50= 1.59 μg/L; EI90= 2.63 μg/L). Triflumuron was also effective against seven Ae. aegypti Brazilian populations resistant to both temephos and deltamethrin. Exposure of all the Ae. aegypti populations to the triflumuron EI99 of the susceptible reference strain, Rockefeller, resulted in complete inhibition of adult emergence, suggesting no cross-resistance among traditional insecticides and this CSI. However, a positive correlation between temephos resistance and tolerance to triflumuron was observed. Conclusion The results suggest that triflumuron represents a potential tool for the control of disease vectors in public

  3. Laboratory analysis of gas hydrate cores for evaluation of reservoir conditions. For the months January 1, 1984-May 31, 1984

    SciTech Connect

    Holder, G.D.

    1984-01-01

    The objective is to provide technical assistance to METC's effort to develop a leading program in the evaluation of hydrate samples in porous media at reservoir conditions. An existing computer program has been modified to calculate enthalpies of dissociation, equilibrium pressures, and earth temperature-depth profiles for hydrate formation as a function of gas composition. In this report results of the depth-temperature studies are presented. The effect of gas composition, geothermal gradient, permafrost thickness and pressure gradient on the thickness of a hydrate stability zone in permafrost regions is covered. The effect of ocean bottom temperature, gas composition and ocean depth on a hydrate stability zone beneath the ocean is shown. These variables are considered to be among the more important in determining the potential that a particular region has for containing hydrates and they need to be measured in any geological investigation of a region. 24 references, 11 figures, 1 table.

  4. [Genomic instability after exposure to radiation at low doses (in the 10-kilometer zone of the accident at the Chernobyl Atomic Electric Power Station and under laboratory conditions)].

    PubMed

    Pelevina, I I; Gotlib, V Ia; Kudriashova, O V; Serebrianyĭ, A M; Afanas'ev, G G

    1996-01-01

    The results of series investigations of late effects after Chernobyl accident are discussed. Genomic instability induced by chronic irradiation of cultural cells in Chernobyl zone and in laboratory conditions have been studied. It was shown that low level prolonged irradiation result in increase of frequency of cells with micronuclei, giant cells, enhancement of radiosensitivity in descendents of early irradiated cells. Chronic low doses irradiation doesn't induce the adaptive response. Comparative investigation of adaptive response in blood lymphocytes of people (adults and children) living in Moscow and in regions polluted with radionuclides (5-40 ci/km2) after Chernobyl disaster have been conducted. In population from contaminated areas the frequency of individuals with definite adaptive response is decreased and there are individuals with increasing radiosensitivity after irradiation in conditioned dose. Chronic irradiation during living on contaminated areas don't induce the adaptive response.

  5. Formation and behaviour of dust particle clouds in a radio-frequency discharge: results in the laboratory and under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Mikikian, M.; Boufendi, L.; Bouchoule, A.; Thomas, H. M.; Morfill, G. E.; Nefedov, A. P.; Fortov, V. E.; PKE-Nefedov Team

    2003-03-01

    In this paper we report the first observation on submicron dust particle clouds grown in a radio-frequency sputtering discharge under microgravity conditions. These results have been obtained in the PKE-Nefedov (Plasma Kristall Experiment) chamber in the framework of a French-German-Russian programme. A dust-free region, usually called the `void', is observed in the laboratory and under microgravity conditions even with submicron particles. In this region, successive generations of particles can be grown, leading to the coexistence of particles with various sizes. Each generation of particles constitutes a cloud separated from the others by a definite sheath. Dynamics of these clouds have been investigated showing vortex-like motions or independent behaviour of small heaps of particles, emphasizing both attractive and repulsive effects between dust clouds. As these particles drastically influence the plasma properties, the growth kinetics is followed through the evolution of the discharge current.

  6. Ranking the significance of fermentation conditions on the volatile organic compounds of Tuber melanosporum fermentation system by combination of head-space solid phase microextraction and chromatographic fingerprint similarity analysis.

    PubMed

    Li, Dao-Cheng; Liu, Rui-Sang; Li, Hong-Mei; Yuan, Zhan-Peng; Chen, Tao; Tang, Ya-Jie

    2014-03-01

    Tuber melanosporum is highly appreciated in culinary contexts due to its unique and characteristic aroma. T. melanosporum fermentation has been established as a promising alternative for fruiting bodies to produce volatile organic compounds (VOCs). In this work, a technique using a combination of chromatographic fingerprint similarity analysis, head-space solid phase microextraction and gas chromatography was developed to rank the significance of fermentation conditions on the VOCs profile during T. melanosporum fermentation. Omission tests indicated that the absence of major carbon source (i.e., sucrose) in the fermentation media had the most significant effect on the profile of VOCs, followed by the absence of yeast extract or peptone. Consideration of the culture conditions revealed that VOCs produced was the most significantly affected by temperature. These results indicated that it is possible to adjust the aroma of truffles via fermentation process control.

  7. Study of the Stability of Various Biochemical Analytes in Samples Stored at Different Predefined Storage Conditions at an Accredited Laboratory of India

    PubMed Central

    Kachhawa, Kamal; Kachhawa, Poonam; Varma, Meena; Behera, Rasmirekha; Agrawal, Divya; Kumar, Sanjay

    2017-01-01

    Background: Storage of serum and other blood products is often necessary in laboratories because of technical issues or to preserve samples for subsequent research purposes. The aim of this study was to determine whether the stability of biochemical analytes is affected by storage conditions. Materials and Methods: A total of 17 biochemical analytes in the sera of ten patients were examined following storage. Subsequent to determining the baseline measurements, the serum of each patient was aliquoted and stored at −20°C for 7, 15, and 30 days and then analyzed for stability. The results were compared with the initial analysis measurements obtained from fresh samples. Mean changes compared to baseline (T0) concentrations were evaluated both statistically and clinically. Results: Our results show that sodium, potassium, urea, creatinine, uric acid, total calcium, phosphorus, direct bilirubin, total bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total protein, albumin, cholesterol, and triglyceride levels were stable under all conditions. Serum amylase was the only analyte demonstrating instability following prolonged storage; amylase levels changed significantly (both statistically and clinically) at 7, 15, and 30 days (P < 0.05). Conclusion: Most common biochemical analytes, except for amylase, showed adequate stability in serum following 30 days of storage at −20­C. Serum amylase analysis should be conducted on the same day that the sample is received in the laboratory. PMID:28042210

  8. Stratigraphy and hydrologic conditions at the Brookhaven National Laboratory and vicinity, Suffolk County, New York, 1994-97

    USGS Publications Warehouse

    Scorca, Michael P.; Dorsch, William R.; Paquette, Douglas E.

    1999-01-01

    Brookhaven National Laboratory (BNL) has installed many test borings as part of an effort to delineate the extent of ground-water contamination at the site. In 1994, the U.S. Geological Survey began a study in cooperation with BNL to define the stratigraphy in the 28-square-mile area encompassing BNL, and to monitor ground-water levels in the 300 squaremile area of central Suffolk County that surrounds BNL. The uppermost geologic units at BNL are of Pleistocene age. These sediments are underlain unconformably by the Matawan Group-Magothy Formation, undifferentiated (referred to as the Magothy Formation), of Cretaceous age, which typically consists of light- to dark-gray, variably sorted sand interbedded with light- to dark-gray clay layers; it also contains beds of grayish-brown to brownish-gray sand. Bed thicknesses differ substantially within each boring and tend to be laterally discontinuous as a result of their terrestrial deltaic depositional environment, although a prominent clay unit, referred to as the ?grayish-brown clay? in this report, was encountered at many borings. Pollen-sample analyses confirm that this unit is of Cretaceous age and is the uppermost unit of Cretaceous sediments in several parts of the study area. The upper surface of the Cretaceous deposits is irregular within the 28-square-mile study area and has relief of about 120 feet. Several prominent channels and ridges in the surface are aligned generally northwest-southeast. The Cretaceous surface beneath BNL is characterized more by local erosional features than by the regional cuesta shape that was suggested by previous authors. The overlying Pleistocene-aged units include (1) a sand layer overlain by the Gardiners Clay, (2) the Gardiners Clay, and (3) upper Pleistocene deposits, which include the Upton unit, glacial outwash, glaciolacustrine deposits, and terminal moraine deposits. The sand unit below the Gardiners Clay was the first Pleistocene unit to be deposited atop the irregular

  9. Strength, stability, and microstructure of simulated calcite faults sheared under laboratory conditions spanning the brittle-ductile transition

    NASA Astrophysics Data System (ADS)

    Niemeijer, A. R.; Verberne, B. A.; De Bresser, J. H. P.; Spiers, C. J.

    2015-12-01

    We present the results of an experimental investigation of the mechanisms controlling slip of simulated fault gouges composed of calcite (CaCO3). Shear (friction) tests were carried out using the saw-cut, direct-, as well as the ring-shear geometries, at conditions spanning the brittle-to-ductile transition. Sheared gouges were recovered for micro- and nanostructural study. Experiments using an effective normal stress of 50 MPa and sliding velocities (v) of 0.1 to 10 μm/s showed velocity (v-) weakening in the temperature range from ~80-100ºC to ~550ºC, frequently associated with stick-slip. Below 80-100ºC, and > ~550ºC, stable v-strengthening was observed. The microstructures of all gouges recovered from tests performed at 20° to 200°C showed the presence of nanocrystalline shear bands with internal, fibrous, mirror-like patches and a crystallographic preferred orientation. By contrast, at 400° to 600°C, microstructures showed evidence for localized slip in a boundary shear alongside more distributed deformation, involving grain size sensitive (GSS) and/ or grain size insensitive (GSI) creep of ~10-30 μm-sized grains. Our interpretation is that fault gouge strength and its velocity dependence are controlled by a competition between dilatant granular flow vs. creep-controlled compaction. Specifically, the transition from v-strengthening to v-weakening behaviour at 80° to 100°C is interpreted to occur due to accelerated intergranular diffusive mass transfer at elevated temperatures, while at 550° to 600°C, localized, v-weakening slip involving balanced dilatant flow and creep-controlled compaction gives way to pervasive, stable v-strengthening viscous/ plastic shear involving GSS and/ or GSI deformation. Our results have important implications for seismicity in limestone terrains, and for the interpretation of natural fault rock microstructures. The sheared gouge micro- and nanostructures reported demonstrate the importance of nanoscale fault slip

  10. Tensile and Fatigue Testing and Material Hardening Model Development for 508 LAS Base Metal and 316 SS Similar Metal Weld under In-air and PWR Primary Loop Water Conditions

    SciTech Connect

    Mohanty, Subhasish; Soppet, William; Majumdar, Saurin; Natesan, Ken

    2015-09-01

    This report provides an update on an assessment of environmentally assisted fatigue for light water reactor components under extended service conditions. This report is a deliverable in September 2015 under the work package for environmentally assisted fatigue under DOE’s Light Water Reactor Sustainability program. In an April 2015 report we presented a baseline mechanistic finite element model of a two-loop pressurized water reactor (PWR) for systemlevel heat transfer analysis and subsequent thermal-mechanical stress analysis and fatigue life estimation under reactor thermal-mechanical cycles. In the present report, we provide tensile and fatigue test data for 508 low-alloy steel (LAS) base metal, 508 LAS heat-affected zone metal in 508 LAS–316 stainless steel (SS) dissimilar metal welds, and 316 SS-316 SS similar metal welds. The test was conducted under different conditions such as in air at room temperature, in air at 300 oC, and under PWR primary loop water conditions. Data are provided on materials properties related to time-independent tensile tests and time-dependent cyclic tests, such as elastic modulus, elastic and offset strain yield limit stress, and linear and nonlinear kinematic hardening model parameters. The overall objective of this report is to provide guidance to estimate tensile/fatigue hardening parameters from test data. Also, the material models and parameters reported here can directly be used in commercially available finite element codes for fatigue and ratcheting evaluation of reactor components under in-air and PWR water conditions.

  11. Similarity transformed semiclassical dynamics

    NASA Astrophysics Data System (ADS)

    Van Voorhis, Troy; Heller, Eric J.

    2003-12-01

    In this article, we employ a recently discovered criterion for selecting important contributions to the semiclassical coherent state propagator [T. Van Voorhis and E. J. Heller, Phys. Rev. A 66, 050501 (2002)] to study the dynamics of many dimensional problems. We show that the dynamics are governed by a similarity transformed version of the standard classical Hamiltonian. In this light, our selection criterion amounts to using trajectories generated with the untransformed Hamiltonian as approximate initial conditions for the transformed boundary value problem. We apply the new selection scheme to some multidimensional Henon-Heiles problems and compare our results to those obtained with the more sophisticated Herman-Kluk approach. We find that the present technique gives near-quantitative agreement with the the standard results, but that the amount of computational effort is less than Herman-Kluk requires even when sophisticated integral smoothing techniques are employed in the latter.

  12. Evaluation of the biocompatibility of NiTi dental wires: a comparison of laboratory experiments and clinical conditions.

    PubMed

    Toker, S M; Canadinc, D

    2014-07-01

    Effects of intraoral environment on the surface degradation of nickel-titanium (NiTi) shape memory alloy orthodontic wires was simulated through ex situ static immersion experiments in artificial saliva. The tested wires were compared to companion wires retrieved from patients in terms of chemical changes and formation of new structures on the surface. Results of the ex situ experiments revealed that the acidic erosion effective at the earlier stages of immersion led to the formation of new structures as the immersion period approached 30 days. Moreover, comparison of these results with the analysis of wires utilized in clinical treatment evidenced that ex situ experiments are reliable in terms predicting C-rich structure formation on the wire surfaces. However, the formation of C pileups at the contact sites of arch wires and brackets could not be simulated with the aid of static immersion experiments, warranting the simulation of the intraoral environment in terms of both chemical and physical conditions, including mechanical loading, when evaluating the biocompatibility of NiTi orthodontic arch wires.

  13. Interspecific Competition Between Ceratitis capitata and Two Bactrocera Spp. (Diptera: Tephritidae) Evaluated via Adult Behavioral Interference Under Laboratory Conditions.

    PubMed

    Liu, Hui; Zhang, Can; Hou, Bo-Hua; Ou-Yang, Ge-Cheng; Ma, Jun

    2017-03-15

    The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is considered one of the most invasive tephritid species. It has spread and established populations successfully throughout many of the tropical temperate regions, partially owing to the increase in global trading activity that facilitates diffusion of species. However, C. capitata has never been detected in China, even though some areas of the country have favorable climate and ample food resources. Historically, some researchers have hypothesized that the principal reasons for its absence are the defenses mounted by native Bactrocera species against C. capitata. We evaluated the modes and strengths of interspecific competition between C. capitata and two Bactrocera species (Bactrocera dorsalis Hendel and Bactrocera correcta Bezzi) by conducting experiments on behavioral interference between the adults of these fruit fly species. Under appropriate conditions, the two Bactrocera species showed a distinct advantage in competition for oviposition, noticeably suppressing C. capitata. Although no mating interference between C. capitata and the two Bactrocera species was observed, the role of interference competition in the prevention of C. capitata invasion is still worthy of being discussed.

  14. Effect of Commercial Cyanobacteria Products on the Growth and Antagonistic Ability of Some Bioagents under Laboratory Conditions

    PubMed Central

    El-Mougy, Nehal S.; Abdel-Kader, Mokhtar M.

    2013-01-01

    Evaluation of the efficacy of blue-green algal compounds against the growth of either pathogenic or antagonistic microorganisms as well as their effect on the antagonistic ability of bioagents was studied under in vitro conditions. The present study was undertaken to explore the inhibitory effect of commercial algal compounds, Weed-Max and Oligo-Mix, against some soil-borne pathogens. In growth medium supplemented with these algal compounds, the linear growth of pathogenic fungi decreased by increasing tested concentrations of the two algal compounds. Complete reduction in pathogenic fungal growth was observed at 2% of both Weed-Max and Oligo-Mix. Gradual significant reduction in the pathogenic fungal growth was caused by the two bioagents and by increasing the concentrations of algal compounds Weed-Max and Oligo-Mix. The present work showed that commercial algal compounds, Weed-Max and Oligo-Mix, have potential for the suppression of soil-borne fungi and enhance the antagonistic ability of fungal, bacterial, and yeast bio-agents. PMID:24307948

  15. Transcriptional profiling induced by pesticides employed in organic agriculture in a wild population of Chironomus riparius under laboratory conditions.

    PubMed

    Lencioni, Valeria; Grazioli, Valentina; Rossaro, Bruno; Bernabò, Paola

    2016-07-01

    Copper (Cu) and azadirachtin (AZA-A+B) are pesticides allowed in organic agriculture whose environmental risk and toxicity for aquatic wildlife is only partially known. Reverse Transcription Polymerase Chain Reaction was used to assess the molecular effect of acute and short-term exposure (3, 24h) of Cu (0.01, 0.05, 1, 10, 25mgl(-1)) and AZA-A+B (0.2, 0.3, 0.4, 0.5, 1mgl(-1)) on the expression of five candidate genes (hsp70, hsc70, hsp40, hsp10 and cyP450) in a non-target species, Chironomus riparius. Fourth-instar larvae were collected from a mountain stream polluted by agricultural land run-off. All genes were responsive to both pesticides but each gene had a specific response to the different experimental concentrations and exposure times. A few similarities in transcriptional profiling were observed, such as a linear concentration-dependent response of hsp70 after 24h of exposure (at ≥1mgl(-1) of Cu and ≥0.2mgl(-1) of AZA-A+B) and an up-regulation regardless of the concentration of hsc70 after 24h of exposure (at ≥0mgl(-1) of Cu and ≥0.2mgl(-1) of AZA-A+B and the up-regulation of hsp70 after 3h of exposure at ~LC50 (Cu-LC50=26.1±2.5mgl(-1), AZA-A+B-LC50=1.1±0.2mgl(-1)). According to the results, hsp40, hsp10 and cyP450 may be defined as pesticide-dependent (i.e., hsp40 and hsp10 seemed to responded mainly to AZA-A+B and cyP450 to Cu), while hsc70 as time-dependent regardless of the pesticide (i.e., hsc70 responded only after 24h of treatment with Cu and AZA-A+B). This study gives new insights on the potential role of the C. riparius's hsps and cyP450 genes as sensitive biomarkers for freshwater monitoring.

  16. Laboratory-scale interaction between CO2-rich brine and limestone and sandstone under supercritical CO2 conditions

    NASA Astrophysics Data System (ADS)

    Garcia-Rios, Maria; Cama, Jordi; Luquot, Linda; Soler, Josep

    2014-05-01

    A test site for a prospective CO2 geological storage is situated in Hontomín (Burgos, northern Spain) with a reservoir rock that is composed of limestone (calcite) and sandstone (66 wt.% calcite, 28 wt.% quartz and 6 wt.% microcline). During and after CO2 injection, the resulting CO2-rich acid brine will likely promote the dissolution of carbonate minerals (calcite) and aluminosilicates (microcline). Since the reservoir Hontomín brine contains sulfate, gypsum (or anhydrite at depth) may precipitate. These coupled dissolution and precipitation reactions may induce changes in porosity and pore structure of the repository rocks. Percolations experiments with mechanically fractured cores (8.6 mm in diameter and 18 mm length) were performed under CO2 supercritical conditions (Pfluid = 150 bar; pCO2 ≡ 90 bar and T = 60 ºC) in order to evaluate and quantify variations in fracture permeability, preferential path formation and fracture volume. The brine sulfate content and the flow rate were varied. Regarding limestone, as the synthetic brines circulated through the fracture, the fracture permeability initially increased slowly, to thereafter increase rapidly. This change was due to a localized dissolution process (wormhole formation) along the core that occurred regardless gypsum precipitation. Nonetheless, the originated fracture volume in the sulfate-rich brine experiments was a factor of two smaller than that in sulfate-free brine experiments. Also, an increase in flow rate from 0.2 to 60 mL/h increased the volume of both dissolved calcite and precipitated gypsum. Regarding sandstone, permeability increased gradually with time. Nonetheless, this increase was not always continuous due to eventual fracture clogging. Formation of wormholes was observed. Acknowledgements This study was financed by CIUDEN (Ciudad de la Energía), the Compostilla OXYCFB300 project and the PANACEA project (European Community's Seventh Framework Programme FP7/2007-2013 under grant

  17. Effect of farm and simulated laboratory cold environmental conditions on the performance and physiological responses of lactating dairy cows supplemented with bovine somatotropin (BST)

    NASA Astrophysics Data System (ADS)

    Becker, B. A.; Johnson, H. D.; Li, R.; Collier, R. J.

    1990-09-01

    A study was conducted to evaluate the effect of bovine somatotropin (BST) supplementation in twelve lactating dairy cows maintained in cold environmental conditions. Six cows were injected daily with 25 mg of BST; the other six were injected with a control vehicle. Cows were maintained under standard dairy management during mid-winter for 30 days. Milk production was recorded twice daily, and blood samples were taken weekly. Animals were then transferred to environmentally controlled chambers and exposed to cycling thermoneutral (15° to 20° C) and cycling cold (-5° to +5° C) temperatures for 10 days in a split-reversal design. Milk production, feed and water intake, body weights and rectal temperatures were monitored. Blood samples were taken on days 1, 3, 5, 8 and 10 of each period and analyzed for plasma triiodothyronine (T3), thyroxine (T4), cortisol, insulin and prolactin. Under farm conditions, BST-treated cows produced 11% more milk than control-treated cows and in environmentally controlled chambers produced 17.4% more milk. No differences due to BST in feed or water intake, body weights or rectal temperatures were found under laboratory conditions. Plasma T3 and insulin increased due to BST treatment while no effect was found on cortisol, prolactin or T4. The results showed that the benefits of BST supplementation in lactating dairy cows were achieved under cold environmental conditions.

  18. Life history of Neoseiulus californicus (McGregor, 1954) (Acari: Phytoseiidae) fed with castor bean (Ricinus communis L.) pollen in laboratory conditions.

    PubMed

    Marafeli, P P; Reis, P R; Silveira, E C da; Souza-Pimentel, G C; de Toledo, M A

    2014-08-01

    The predatory mite, Neoseiulus californicus (McGregor, 1954) (Acari: Phytoseiidae) is one of the principal natural enemies of tetranychid mites in several countries, promoting efficient control of those mites in several food and ornamental crops. Pest attacks such as that of the spider mite, Tetranychus urticae Koch, 1836 (Acari: Tetranychidae), is one of the problems faced by farmers, especially in the greenhouse, due to the difficulty of its control with the use of chemicals because of the development of fast resistance making it hard to control it. The objective of this work was to study the life history of the predatory mite N. californicus as a contribution to its mass laboratory rearing, having castor bean plant [Ricinus communis L. (Euphorbiaceae)] pollen as food, for its subsequent use as a natural enemy of T. urticae on a cultivation of greenhouse rosebushes. The studies were carried out in the laboratory, at 25 ± 2°C of temperature, 70 ± 10% RH and a 14 hour photophase. The biological aspects and the fertility life table were appraised. Longevity of 32.9 days was verified for adult females and 40.4 days for males. The intrinsic rate of increase (rm) was 0.2 and the mean generation time (T) was 17.2 days. The population doubled every 4.1 days. The results obtained were similar to those in which the predatory mite N. californicus fed on T. urticae.

  19. Laboratory and modeling studies on the effects of water and soot emissions and ambient conditions on the formation of contrail ice particles in the jet regime

    NASA Astrophysics Data System (ADS)

    Wong, H.-W.; Beyersdorf, A. J.; Heath, C. M.; Ziemba, L. D.; Winstead, E. L.; Thornhill, K. L.; Tacina, K. M.; Ross, R. C.; Albo, S. E.; Bulzan, D. L.; Anderson, B. E.; Miake-Lye, R. C.

    2011-09-01

    Contrails and contrail-induced cirrus clouds are identified as the most uncertain components in determining aviation impacts on global climate change. Parameters affecting contrail ice particle formation immediately after engine exit plane (<5 s in plume age) may be critical to ice particle properties used in large scale models predicting contrail radiative forcing. Despite this, detailed understanding of these parametric effects is still limited. In this paper, we present results from recent laboratory and modeling studies conducted to investigate the effects of water and soot emissions and ambient conditions on the near-field formation of contrail ice particles. The Particle Aerosol Laboratory (PAL) at the NASA Glenn Research Center and the Aerodyne microphysical parcel model for contrail ice particle formation were employed. Our studies show that exhaust water concentrations have a significant impact on contrail ice particle formation. When soot was introduced, ice particle formation was observed only when exhaust water concentration was above a critical level. When no soot or sulfuric acid was introduced, homogeneous ice particle formation was unfavorable. Soot particles were found to compete for water vapor condensation, and higher soot concentrations emitted into the chamber resulted in smaller ice particles being formed. Chamber conditions corresponding to higher altitude standard day conditions were found to favor ice particle formation as expected. The microphysical model captures experimental trends well, but discrepancies between the model and the experiments exist as the model predicts narrower ice particle size distributions and ice particle sizes nearly a factor of two larger than measured. These discrepancies are likely due to the lack of treatment of turbulent mixing in the model and particle loss and scatter during the experimental sampling process. Future measurement activities are planned to investigate other important parameters, such as soot

  20. Laboratory Astrochemistry: Interstellar PAHs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are thought to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: (1) objectives, (2) approach and techniques adopted, (3) adaptability to the nature of the problem(s), and (4) results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a

  1. Comparison of cyanobacterial microcystin synthetase (mcy) E gene transcript levels, mcy E gene copies, and biomass as indicators of microcystin risk under laboratory and field conditions.

    PubMed

    Ngwa, Felexce F; Madramootoo, Chandra A; Jabaji, Suha

    2014-08-01

    Increased incidences of mixed assemblages of microcystin-producing and nonproducing cyanobacterial strains in freshwater bodies necessitate development of reliable proxies for cyanotoxin risk assessment. Detection of microcystin biosynthetic genes in water blooms of cyanobacteria is generally indicative of the presence of potentially toxic cyanobacterial strains. Although much effort has been devoted toward elucidating the microcystin biosynthesis mechanisms in many cyanobacteria genera, little is known about the impacts of co-occurring cyanobacteria on cellular growth, mcy gene expression, or mcy gene copy distribution. The present study utilized conventional microscopy, qPCR assays, and enzyme-linked immunosorbent assay to study how competition between microcystin-producing Microcystis aeruginosa CPCC 299 and Planktothrix agardhii NIVA-CYA 126 impacts mcyE gene expression, mcyE gene copies, and microcystin concentration under controlled laboratory conditions. Furthermore, analyses of environmental water samples from the Missisquoi Bay, Quebec, enabled us to determine how the various potential toxigenic cyanobacterial biomass proxies correlated with cellular microcystin concentrations in a freshwater lake. Results from our laboratory study indicated significant downregulation of mcyE gene expression in mixed cultures of M. aeruginosa plus P. agardhii on most sampling days in agreement with depressed growth recorded in the mixed cultures, suggesting that interaction between the two species probably resulted in suppressed growth and mcyE gene expression in the mixed cultures. Furthermore, although mcyE gene copies and McyE transcripts were detected in all laboratory and field samples with measureable microcystin levels, only mcyE gene copies showed significant positive correlations (R(2) > 0.7) with microcystin concentrations, while McyE transcript levels did not. These results suggest that mcyE gene copies are better indicators of potential risks from microcystins

  2. Simulating natural conditions in the laboratory: a re-examination of sexual isolation between sympatric and allopatric populations of Drosophila pseudoobscura and D. persimilis.

    PubMed

    Noor, Mohamed A F; Ortíz-Barrientos, Daniel

    2006-03-01

    Simulating natural conditions in the laboratory poses one of the most significant challenges to behavioral studies. Some authors have argued that laboratory "choice" experiments reflect mate choice in nature more accurately than "no-choice" experiments. A recent choice experiment study questioned the conclusions of several earlier studies by failing to detect a published difference in sexual isolation between populations of Drosophila pseudoobscura, and suggested their result was more robust because of the more realistic design. Here, we re-examine the methods and analyses of this recent study, and we find there was indeed a difference in sexual isolation between populations of D. pseudoobscura. We also conduct a more rigorously controlled choice experiment and, in agreement with previous studies, note that D. pseudoobscura females from populations sympatric to their sibling species, D. persimilis, exhibit greater sexual isolation than those from allopatric populations. Our results confirm the existence of a geographic pattern in sexual isolation in D. pseudoobscura, and we discuss differences in experimental designs in light of the biology of this species.

  3. Persistence of the herbicides (/sup 14/C)chlorsulfuron and (/sup 14/C)metsulfuron methyl in prairie soils under laboratory conditions

    SciTech Connect

    Smith, A.E.

    1986-11-01

    Metsulfuron methyl, whose structure is closely related to that of chlorsulfuron, is currently being evaluated on the Canadian prairies as a postemergence treatment for the control of broadleaf weeds in cereal crops, in non-crop land and for brush control. Although applied postemergence, some of the herbicide will come into contact with the soil making it necessary to determine the fate of metsulfuron methyl in the soil. These studies were undertaken to investigate the rate of breakdown and the fate of (/sup 14/C)metsulfuron methyl in three soils under laboratory conditions where no leaching could occur. The rate of breakdown of (/sup 14/C)chlorsulfuron was also investigated in one of the soils.

  4. High-resolution monitoring of root water uptake dynamics in laboratory conditions using full-wave inversion of near-field radar

    NASA Astrophysics Data System (ADS)

    Mourmeaux, Nicolas; Meunier, Félicien; Tran, Phuong Anh; Draye, Xavier; Lambot, Sébastien

    2014-05-01

    Root water uptake dynamics at local scale can be studied in laboratory conditions by growing plants in rhizotron containing sand and by imaging the water content evolution of the medium using light transmission. This technique allows to retrieve the water content with high resolution but cannot be applied in opaque media such as leaf-mold or clay, which is a major limitation for more realistic applications. Recently, ground-penetrating radar (GPR) has proven to be one of the most promising techniques for high-resolution digital soil mapping at the field scale. Particularly, by using full-wave inverse modeling of near-field GPR data with a high frequency antenna, the electrical properties of soil and their correlated water content can be reconstructed with a high spatiotemporal resolution. In this study, we applied the approach by using an ultra-wideband frequency-domain radar with a transmitting and receiving horn antenna operating in the frequency range 3-6 GHz for imaging, in near-field conditions, a rhizotron containing sand subject to different water content conditions. Synthetic radar data were also generated to examine the well-posedness of the full-waveform inverse problem at high frequencies. Finally, we compared the water content obtained by GPR and light transmission measurements. The results have shown that the near-field modeled and measured GPR data match very well in the frequency and time domains for both dry and wet sands. In the case of the dry sand, the estimated water content based on GPR and light transmission data was retrieved with small differences. This research shows the potential of the GPR system and near-field full-wave antenna-medium model to accurately estimate the water content of soils with a high spatial resolution. Future studies will focus on the use of GPR to monitor root water uptake dynamics of plants in field conditions. This abstract is of interest for COST Action TU1208.

  5. Approaching Mars-like Geochemical Conditions in the Laboratory: Omission of Artificial Buffers and Reductants in a Study of Biogenic Methane Production on a Smectite Clay

    NASA Astrophysics Data System (ADS)

    Chastain, Brendon K.; Kral, Timothy A.

    2010-11-01

    Methanogens have not been shown to metabolize in conditions exactly analogous to those present in Mars' subsurface. In typical studies of methanogenic metabolism, nutrient-rich buffered media and reducing agents are added to the cultures in an attempt to optimize the environment for methanogen survival and growth. To study methanogens in more Mars-relevant laboratory conditions, efforts should be made to eliminate artificial media, buffers, and reducing agents from investigations of methanogenic metabolism. After preliminary work to compare methanogen viability on montmorillonite clay and JSC Mars-1 regolith simulant, a study was conducted to determine whether biological methanogenesis could occur in non-reduced, non-buffered environments containing only H2, CO2, montmorillonite, and the liquid fraction extracted from a montmorillonite/deionized water suspension. Biogenic methane was observed in the microenvironments despite the omission of traditional media, buffers, and reducing agents. Mean headspace methane concentration after 96 days of observation was 10.23 ± 0.64% (% vol ± SEM, n = 4). However, methane production was severely decreased with respect to reduced, buffered microenvironments (Day 28: 31.98% ± 0.19%, n = 3). Analysis of results and comparison to previous work indicate that montmorillonite clay has a strong ability to supply micronutrients necessary for methanogenic metabolism, and the liquid fraction from a montmorillonite/deionized water slurry can successfully be used as an alternative to reduced and buffered nutritive media in Mars-relevant studies of methanogenic metabolism.

  6. A laboratory test setup for in situ measurements of the dielectric properties of catalyst powder samples under reaction conditions by microwave cavity perturbation: set up and initial tests.

    PubMed

    Dietrich, Markus; Rauch, Dieter; Porch, Adrian; Moos, Ralf

    2014-09-10

    The catalytic behavior of zeolite catalysts for the ammonia-based selective catalytic reduction (SCR) of nitrogen oxides (NOX) depends strongly on the type of zeolite material. An essential precondition for SCR is a previous ammonia gas adsorption that occurs on acidic sites of the zeolite. In order to understand and develop SCR active materials, it is crucial to know the amount of sorbed ammonia under reaction conditions. To support classical temperature-programmed desorption (TPD) experiments, a correlation of the dielectric properties with the catalytic properties and the ammonia sorption under reaction conditions appears promising. In this work, a laboratory test setup, which enables direct measurements of the dielectric properties of catalytic powder samples under a defined gas atmosphere and temperature by microwave cavity perturbation, has been developed. Based on previous investigations and computational simulations, a resonator cavity and a heating system were designed, installed and characterized. The resonator cavity is designed to operate in its TM010 mode at 1.2 GHz. The first measurement of the ammonia loading of an H-ZSM-5 zeolite confirmed the operating performance of the test setup at constant temperatures of up to 300 °C. It showed how both real and imaginary parts of the relative complex permittivity are strongly correlated with the mass of stored ammonia.

  7. The effect of redox conditions and adaptation time on organic micropollutant removal during river bank filtration: A laboratory-scale column study.

    PubMed

    Bertelkamp, C; Verliefde, A R D; Schoutteten, K; Vanhaecke, L; Vanden Bussche, J; Singhal, N; van der Hoek, J P

    2016-02-15

    This study investigated the redox dependent removal and adaptive behaviour of a mixture of 15 organic micropollutants (OMPs) in laboratory-scale soil columns fed with river water. Three separate pilot systems were used consisting of: (1) two columns, (2) ten columns and (3) twenty two columns to create oxic, suboxic (partial nitrate removal) and anoxic (complete nitrate removal). The pilot set-up has some unique features--it can simulate fairly long residence times (e.g., 45 days using the 22 column system) and reduced conditions developed naturally within the system. Dimethoate, diuron, and metoprolol showed redox dependent removal behaviour with higher biodegradation rates in the oxic zone compared to the suboxic/anoxic zone. The redox dependent behaviour of these three OMPs could not be explained based on their physico-chemical properties (hydrophobicity, charge and molecular weight) or functional groups present in the molecular structure. OMPs that showed persistent behaviour in the oxic zone (atrazine, carbamazepine, hydrochlorothiazide and simazine) were also not removed under more reduced conditions. Adaptive behaviour was observed for five OMPs: dimethoate, chloridazon, lincomycin, sulfamethoxazole and phenazone. However, the adaptive behaviour could not be explained by the physico-chemical properties (hydrophobicity, charge and molecular weight) investigated in this study and only rough trends were observed with specific functional groups (e.g. ethers, sulphur, primary and secondary amines). Finally, the adaptive behaviour of OMPs was found to be an important factor that should be incorporated in predictive models for OMP removal during river bank filtration.

  8. A Laboratory Test Setup for in Situ Measurements of the Dielectric Properties of Catalyst Powder Samples under Reaction Conditions by Microwave Cavity Perturbation: Set up and Initial Tests

    PubMed Central

    Dietrich, Markus; Rauch, Dieter; Porch, Adrian; Moos, Ralf

    2014-01-01

    The catalytic behavior of zeolite catalysts for the ammonia-based selective catalytic reduction (SCR) of nitrogen oxides (NOX) depends strongly on the type of zeolite material. An essential precondition for SCR is a previous ammonia gas adsorption that occurs on acidic sites of the zeolite. In order to understand and develop SCR active materials, it is crucial to know the amount of sorbed ammonia under reaction conditions. To support classical temperature-programmed desorption (TPD) experiments, a correlation of the dielectric properties with the catalytic properties and the ammonia sorption under reaction conditions appears promising. In this work, a laboratory test setup, which enables direct measurements of the dielectric properties of catalytic powder samples under a defined gas atmosphere and temperature by microwave cavity perturbation, has been developed. Based on previous investigations and computational simulations, a resonator cavity and a heating system were designed, installed and characterized. The resonator cavity is designed to operate in its TM010 mode at 1.2 GHz. The first measurement of the ammonia loading of an H-ZSM-5 zeolite confirmed the operating performance of the test setup at constant temperatures of up to 300 °C. It showed how both real and imaginary parts of the relative complex permittivity are strongly correlated with the mass of stored ammonia. PMID:25211199

  9. Laboratory measurements of the 3.7-20 cm wavelength opacity of sulfur dioxide and carbon dioxide under simulated conditions for the deep atmosphere of Venus

    NASA Astrophysics Data System (ADS)

    Steffes, Paul G.; Shahan, Patrick; Christopher Barisich, G.; Bellotti, Amadeo

    2015-01-01

    In the past two decades, multiple observations of Venus have been made at X-Band (3.6 cm) using the Jansky Very Large Array (VLA), and maps have been created of the 3.6 cm emission from Venus (see, e.g., Devaraj, K. [2011]. The Centimeter- and Millimeter-Wavelength Ammonia Absorption Spectra under Jovian Conditions. PhD Thesis, Georgia Institute of Technology, Atlanta, GA). Since the emission morphology is related both to surface features and to deep atmospheric absorption from CO2 and SO2 (see, e.g., Butler, B.J., Steffes, P.G., Suleiman, S.H., Kolodner, M.A., Jenkins, J.M. [2001]. Icarus 154, 226-238), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide atmosphere under conditions for the deep atmosphere of Venus is required for proper interpretation. Except for a single measurement campaign conducted at a single wavelength (3.2 cm) over 40 years ago (Ho, W., Kaufman, I.A., Thaddeus, P. [1966]. J. Geophys. Res. 71, 5091-5108), no measurements of the centimeter-wavelength properties of any Venus atmospheric constituent have been conducted under conditions characteristic of the deep atmosphere (pressures from 10 to 92 bars and temperatures from 400 to 700 K). New measurements of the microwave properties of SO2 and CO2 at wavelengths from 3.7 to 20 cm have been conducted under simulated conditions for the deep atmosphere of Venus, using a new high-pressure system. Results from this measurement campaign conducted at temperatures from 430 K to 560 K and at pressures up to 92 bars are presented. Results indicate that the model for the centimeter-wavelength opacity from pure CO2 (Ho, W., Kaufman, I.A., Thaddeus, P. [1966]. J. Geophys. Res. 71, 5091-5108), is valid over the entire centimeter-wavelength range under simulated conditions for the deep atmosphere of Venus. Additionally, the laboratory results indicate that both of the models for the centimeter-wavelength opacity of SO2 in a CO2 atmosphere from Suleiman et al. (Suleiman, S

  10. Effects of glyphosate-based herbicides on survival, development, growth and sex ratios of wood frog (Lithobates sylvaticus) tadpoles. II: agriculturally relevant exposures to Roundup WeatherMax® and Vision® under laboratory conditions.

    PubMed

    Lanctôt, C; Navarro-Martín, L; Robertson, C; Park, B; Jackman, P; Pauli, B D; Trudeau, V L

    2014-09-01

    Glyphosate-based herbicides are currently the most commonly used herbicides in the world. They have been shown to affect survival, growth, development and sexual differentiation of tadpoles under chronic laboratory exposures but this has not been investigated under more environmentally realistic conditions. The purpose of this study is (1) to determine if an agriculturally relevant exposure to Roundup WeatherMax®, a relatively new and understudied formulation, influences the development of wood frog tadpoles (Lithobates sylvaticus) through effects on the mRNA levels of genes involved in the control of metamorphosis; (2) to compare results to the well-studied Vision® formulation (containing the isopropylamine salt of glyphosate [IPA] and polyethoxylated tallowamine [POEA] surfactant) and to determine which ingredient(s) in the formulations are responsible for potential effects on development; and (3) to compare results to recent field studies that used a similar experimental design. In the present laboratory study, wood frog tadpoles were exposed to an agriculturally relevant application (i.e., two pulses) of Roundup WeatherMax® and Vision® herbicides as well as the active ingredient (IPA) and the POEA surfactant of Vision®. Survival, development, growth, sex ratios and mRNA levels of genes involved in tadpole metamorphosis were measured. Results show that Roundup WeatherMax® (2.89 mg acid equivalent (a.e.)/L) caused 100% mortality after the first pulse. Tadpoles treated with a lower concentration of Roundup WeatherMax® (0.21 mg a.e./L) as well as Vision® (2.89 mg a.e./L), IPA and POEA had an increased condition factor (based on length and weight measures in the tadpoles) relative to controls at Gosner stage (Gs) 36/38. At Gs42, tadpoles treated with IPA and POEA had a decreased condition factor. Also at Gs42, the effect on condition factor was dependent on the sex of tadpoles and significant treatment effects were only detected in males. In most cases

  11. Biosimilar Insulins: How Similar is Similar?

    PubMed Central

    Heinemann, Lutz; Hompesch, Marcus

    2011-01-01

    Biosimilar insulins (BIs) are viewed as commercially attractive products by a number of companies. In order to obtain approval in the European Union or the United States, where there is not a single BI currently on the market, a manufacturer needs to demonstrate that a given BI has a safety and efficacy profile that is similar to that of the “original” insulin formulation that is already on the market. As trivial as this may appear at first glance, it is not trivial at all for a good number of reasons that will be discussed in this commentary. As with protein manufacturing, modifications in the structure of the insulin molecule can take place (which can have serious consequences for the biological effects induced), so a rigid and careful assessment is absolutely necessary. The example of Marvel's failed application with the European Medicines Agency provides insights into the regulatory and clinical challenges surrounding the matter of BI. Although a challenging BI approval process might be regarded as a hurdle to keep companies out of certain markets, it is fair to say that the potential safety and efficacy issues surrounding BI are substantial and relevant and do warrant a careful and evidence-driven approval process. PMID:21722590

  12. Larval food quantity affects development time, survival and adult biological traits that influence the vectorial capacity of Anopheles darlingi under laboratory conditions

    PubMed Central

    2012-01-01

    Background The incidence of malaria in the Amazon is seasonal and mosquito vectorial capacity parameters, including abundance and longevity, depend on quantitative and qualitative aspects of the larval diet. Anopheles darlingi is a major malaria vector in the Amazon, representing >95% of total Anopheles population present in the Porto Velho region. Despite its importance in the transmission of the Plasmodium parasite, knowledge of the larval biology and ecology is limited. Studies regarding aspects of adult population ecology are more common than studies on larval ecology. However, in order develop effective control strategies and laboratory breeding conditions for this species, more data on the factors affecting vector biology is needed. The aim of the present study is to assess the effects of larval food quantity on the vectorial capacity of An. darling under laboratory conditions. Methods Anopheles darlingi was maintained at 28°C, 80% humidity and exposed to a daily photoperiod of 12 h. Larvae were divided into three experimental groups that were fed either a low, medium, or high food supply (based on the food amounts consumed by other species of culicids). Each experiment was replicated for six times. A cohort of adults were also exposed to each type of diet and assessed for several biological characteristics (e.g. longevity, bite frequency and survivorship), which were used to estimate the vectorial capacity of each experimental group. Results The group supplied with higher food amounts observed a reduction in development time while larval survival increased. In addition to enhanced longevity, increasing larval food quantity was positively correlated with increasing frequency of bites, longer blood meal duration and wing length, resulting in greater vectorial capacity. However, females had greater longevity than males despite having smaller wings. Conclusions Overall, several larval and adult biological traits were significantly affected by larval food

  13. Search for seasonal rhythmicity of pineal melatonin production in rats under constant laboratory conditions: spectral chronobiological analysis, and relation to solar and geomagnetic variables.

    PubMed

    Bartsch, Hella; Mecke, Dieter; Probst, Hansgeorg; Küpper, Heinz; Seebald, Eckard; Salewski, Lothar; Stehle, Thilo; Bartsch, Christian

    2012-10-01

    Earlier we reported that in a number of experiments pineal melatonin production in rats under constant laboratory conditions displayed seasonal rhythms but subsequently were not always able to confirm this. Since there was no indication under which conditions such rhythms may be present, we performed four consecutive identical experiments with untreated female Sprague-Dawley rats within the same animal room during 1997-2006. Nocturnal urine samples (19-23, 23-3, 3-7 h) were collected at monthly intervals over 494-658 d with 12 animals each in experiments I and II (1997-1999, 1999-2000), 30 animals in experiment III (2002-2004), and 15 in experiment IV (2005-2006). 6-Sulfatoxymelatonin (aMT6s) was measured by ELISA. The excreted aMT6s at each time interval as well as total nocturnal aMT6s-excretion (19-7 h) was submitted to standard statistical analyses as well as to a spectral chronobiological analysis to determine the period lengths of the components involved which was followed by processing with the single cosinor method. Seasonal rhythm components (circannual period length: 360 ± 60 d) were detected in experiment III (2002-2004) for the overall nocturnal excretion as well as for two sub-intervals (23-3 and 3-7 h) and in one night interval of experiment II (23-3 h). Multiple components with mostly short period lengths of around 100 d and some long ones of 500-650 d were found in the other experiments. Systematic MESOR and amplitude variations were observed during the experiments, being highest in experiment II (19-7 h, also 23-3 h and 3-7 h) and lowest in experiments I and IV. These results illustrate that seasonal melatonin rhythms are not a general phenomenon in female laboratory rats indicating an involvement of unknown environmental cues. As an extension of our earlier hypothesis regarding a seasonal Zeitgeber function of the horizontal intensity H of the geomagnetic field showing circannual variations, we assume further modulation by the 11-yrs' sunspot

  14. Measuring Total Flux of Organic Vapors From the Unsaturated Zone Under Natural Conditions: Design, Laboratory and Field Testing of a Flux Chamber Device

    NASA Astrophysics Data System (ADS)

    Tillman, F. D.; Choi, J.; Smith, J. A.

    2002-05-01

    A simple, easy-to-use, and inexpensive device for measuring VOC flux under natural conditions was designed and tested both in a controlled laboratory environment and in a natural field setting. The chamber consists of a stainless-steel right circular cylinder open on one end with a flexible, impermeable membrane allowing for chamber expansion and contraction. Air is pumped from inside the chamber through activated carbon traps and returned to the chamber maintaining a net zero pressure gradient from the inside to the outside of the chamber. The traps are analyzed using thermal desorption/GC-FID and the mass of contaminant is divided by the product of the sampled area and sample time to give VOC flux measured by the chamber. Design parameters for the chamber were selected using continuously stirred tank reactor (CSTR)-equation based modeling under step, sinusoidal and transport-model simulation flux inputs. Laboratory testing of the flux chamber under both diffusion and advection dominated conditions was performed in a device constructed to simulate unsaturated zone transport. Aqueous trichloroethene (TCE) solution was pumped through the bottom of a steel drum inside which 50-cm of fine sand was suspended. For diffusion-dominated transport experiments, the chamber was installed in the sand at the top of the simulator and operated in the same manner as would occur in the field. The flux measurement of the chamber was then compared to flux prediction based on measured linear concentration data from the simulator and Fick's law. Advective transport is initiated in the vadose zone simulator by flowing humidified, pressurized air into an input port in the bottom of the simulator below the suspended porous media. Soil-gas velocity is calculated by dividing the airflow input by the surface area of the simulator. Flux was measured with the chamber and compared to flux predicted using airflow and concentration data from the simulator. Results from both the diffusion-only and

  15. Laboratory and modeling studies on the effects of water and soot emissions and ambient conditions on the properties of contrail ice particles in the jet regime

    NASA Astrophysics Data System (ADS)

    Wong, H.-W.; Beyersdorf, A. J.; Heath, C. M.; Ziemba, L. D.; Winstead, E. L.; Thornhill, K. L.; Tacina, K. M.; Ross, R. C.; Albo, S. E.; Bulzan, D. L.; Anderson, B. E.; Miake-Lye, R. C.

    2013-10-01

    Contrails and contrail-induced cirrus clouds are identified as the most uncertain components in determining aviation impacts on global climate change. Parameters affecting contrail ice particle formation immediately after the engine exit plane (< 5 s in plume age) may be critical to ice particle properties used in large-scale models predicting contrail radiative forcing. Despite this, detailed understanding of these parametric effects is still limited. In this paper, we present results from recent laboratory and modeling studies conducted to investigate the effects of water and soot emissions and ambient conditions on near-field formation of contrail ice particles and ice particle properties. The Particle Aerosol Laboratory (PAL) at the NASA Glenn Research Center and the Aerodyne microphysical parcel model for contrail ice particle formation were employed. Our studies show that exhaust water concentration has a significant impact on contrail ice particle formation and properties. When soot particles were introduced, ice particle formation was observed only when exhaust water concentration was above a critical level. When no soot or sulfuric acid was introduced, no ice particle formation was observed, suggesting that ice particle formation from homogeneous nucleation followed by homogeneous freezing of liquid water was unfavorable. Soot particles were found to compete for water vapor condensation, and higher soot concentrations emitted into the chamber resulted in smaller ice particles being formed. Chamber conditions corresponding to higher cruising altitudes were found to favor ice particle formation. The microphysical model captures trends of particle extinction measurements well, but discrepancies between the model and the optical particle counter measurements exist as the model predicts narrower ice particle size distributions and ice particle sizes nearly a factor of two larger than measured. These discrepancies are likely due to particle loss and scatter

  16. Molecular similarity measures.

    PubMed

    Maggiora, Gerald M; Shanmugasundaram, Veerabahu

    2011-01-01

    Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of chemical space. Although all three concepts - molecular similarity, molecular representation, and chemical space - are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations that are of the same mathematical form into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another. An expanded account of the material on chemical spaces presented in the first edition of this book is also provided. It includes a discussion of the topography of activity landscapes and the role that activity cliffs in these landscapes play in structure-activity studies.

  17. Molecular similarity measures.

    PubMed

    Maggiora, Gerald M; Shanmugasundaram, Veerabahu

    2004-01-01

    Molecular similarity is a pervasive concept in chemistry. It is essential to many aspects of chemical reasoning and analysis and is perhaps the fundamental assumption underlying medicinal chemistry. Dissimilarity, the complement of similarity, also plays a major role in a growing number of applications of molecular diversity in combinatorial chemistry, high-throughput screening, and related fields. How molecular information is represented, called the representation problem, is important to the type of molecular similarity analysis (MSA) that can be carried out in any given situation. In this work, four types of mathematical structure are used to represent molecular information: sets, graphs, vectors, and functions. Molecular similarity is a pairwise relationship that induces structure into sets of molecules, giving rise to the concept of a chemistry space. Although all three concepts molecular similarity, molecular representation, and chemistry space are treated in this chapter, the emphasis is on molecular similarity measures. Similarity measures, also called similarity coefficients or indices, are functions that map pairs of compatible molecular representations, that is, representations of the same mathematical form, into real numbers usually, but not always, lying on the unit interval. This chapter presents a somewhat pedagogical discussion of many types of molecular similarity measures, their strengths and limitations, and their relationship to one another.

  18. Similarity spectra analysis of high-performance jet aircraft noise.

    PubMed

    Neilsen, Tracianne B; Gee, Kent L; Wall, Alan T; James, Michael M

    2013-04-01

    Noise measured in the vicinity of an F-22A Raptor has been compared to similarity spectra found previously to represent mixing noise from large-scale and fine-scale turbulent structures in laboratory-scale jet plumes. Comparisons have been made for three engine conditions using ground-based sideline microphones, which covered a large angular aperture. Even though the nozzle geometry is complex and the jet is nonideally expanded, the similarity spectra do agree with large portions of the measured spectra. Toward the sideline, the fine-scale similarity spectrum is used, while the large-scale similarity spectrum provides a good fit to the area of maximum radiation. Combinations of the two similarity spectra are shown to match the data in between those regions. Surprisingly, a combination of the two is also shown to match the data at the farthest aft angle. However, at high frequencies the degree of congruity between the similarity and the measured spectra changes with engine condition and angle. At the higher engine conditions, there is a systematically shallower measured high-frequency slope, with the largest discrepancy occurring in the regions of maximum radiation.

  19. The Gender Similarities Hypothesis

    ERIC Educational Resources Information Center

    Hyde, Janet Shibley

    2005-01-01

    The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses…

  20. Approaching Mars-like geochemical conditions in the laboratory: omission of artificial buffers and reductants in a study of biogenic methane production on a smectite clay.

    PubMed

    Chastain, Brendon K; Kral, Timothy A

    2010-11-01

    Methanogens have not been shown to metabolize in conditions exactly analogous to those present in Mars' subsurface. In typical studies of methanogenic metabolism, nutrient-rich buffered media and reducing agents are added to the cultures in an attempt to optimize the environment for methanogen survival and growth. To study methanogens in more Mars-relevant laboratory conditions, efforts should be made to eliminate artificial media, buffers, and reducing agents from investigations of methanogenic metabolism. After preliminary work to compare methanogen viability on montmorillonite clay and JSC Mars-1 regolith simulant, a study was conducted to determine whether biological methanogenesis could occur in non-reduced, non-buffered environments containing only H(2), CO(2), montmorillonite, and the liquid fraction extracted from a montmorillonite/deionized water suspension. Biogenic methane was observed in the microenvironments despite the omission of traditional media, buffers, and reducing agents. Mean headspace methane concentration after 96 days of observation was 10.23% ± 0.64% (% vol ± SEM, n = 4). However, methane production was severely decreased with respect to reduced, buffered microenvironments (Day 28: 31.98% ± 0.19%, n = 3). Analysis of results and comparison to previous work indicate that montmorillonite clay has a strong ability to supply micronutrients necessary for methanogenic metabolism, and the liquid fraction from a montmorillonite/deionized water slurry can successfully be used as an alternative to reduced and buffered nutritive media in Mars-relevant studies of methanogenic metabolism.

  1. Measurements of Chlorpyrifos Levels in Forager Bees and Comparison with Levels that Disrupt Honey Bee Odor-Mediated Learning Under Laboratory Conditions.

    PubMed

    Urlacher, Elodie; Monchanin, Coline; Rivière, Coraline; Richard, Freddie-Jeanne; Lombardi, Christie; Michelsen-Heath, Sue; Hageman, Kimberly J; Mercer, Alison R

    2016-02-01

    Chlorpyrifos is an organophosphate pesticide used around the world to protect food crops against insects and mites. Despite guidelines for chlorpyrifos usage, including precautions to protect beneficial insects, such as honeybees from spray drift, this pesticide has been detected in bees in various countries, indicating that exposure still occurs. Here, we examined chlorpyrifos levels in bees collected from 17 locations in Otago, New Zealand, and compared doses of this pesticide that cause sub-lethal effects on learning performance under laboratory conditions with amounts of chlorpyrifos detected in the bees in the field. The pesticide was detected at 17 % of the sites sampled and in 12 % of the colonies examined. Amounts detected ranged from 35 to 286 pg.bee(-1), far below the LD50 of ~100 ng.bee(-1). We detected no adverse effect of chlorpyrifos on aversive learning, but the formation and retrieval of appetitive olfactory memories was severely affected. Chlorpyrifos fed to bees in amounts several orders of magnitude lower than the LD50, and also lower than levels detected in bees, was found to slow appetitive learning and reduce the specificity of memory recall. As learning and memory play a central role in the behavioral ecology and communication of foraging bees, chlorpyrifos, even in sublethal doses, may threaten the success and survival of this important insect pollinator.

  2. Complete larval development of the hermit crabs Clibanarius aequabilis and Clibanarius erythropus (Decapoda: Anomura: Diogenidae), under laboratory conditions, with a revision of the larval features of genus Clibanarius

    NASA Astrophysics Data System (ADS)

    Bartilotti, Cátia; Calado, Ricardo; Dos Santos, Antonina

    2008-06-01

    The complete larval development (four zoeae and one megalopa) of Clibanarius aequabilis and C. erythropus, reared under laboratory conditions, is described and illustrated. The larval stages of the two northeastern Atlantic Clibanarius species cannot be easily differentiated. Their morphological characters are compared with those of other known Clibanarius larvae. The genus Clibanarius is very homogeneous with respect to larval characters. All Clibanarius zoeae display a broad and blunt rostrum, smooth abdominal segments and an antennal scale without a terminal spine. Beyond the second zoeal stage, the fourth telson process is present as a fused spine, and the uropods are biramous. In the fourth larval stage all species display a mandibular palp. The Clibanarius megalopa presents weakly developed or no ocular scales, symmetrical chelipeds, apically curved corneous dactylus in the second and third pereiopods, and 5-11 setae on the posterior margin of the telson. Apart from the number of zoeal stages, Clibanarius species may be separated, beyond the second zoeal stage, by the telson formula and the morphology of the fourth telson process.

  3. The gender similarities hypothesis.

    PubMed

    Hyde, Janet Shibley

    2005-09-01

    The differences model, which argues that males and females are vastly different psychologically, dominates the popular media. Here, the author advances a very different view, the gender similarities hypothesis, which holds that males and females are similar on most, but not all, psychological variables. Results from a review of 46 meta-analyses support the gender similarities hypothesis. Gender differences can vary substantially in magnitude at different ages and depend on the context in which measurement occurs. Overinflated claims of gender differences carry substantial costs in areas such as the workplace and relationships.

  4. Optimization of detection conditions and single-laboratory validation of a multiresidue method for the determination of 135 pesticides and 25 organic pollutants in grapes and wine by gas chromatography time-of-flight mass spectrometry.

    PubMed

    Dasgupta, Soma; Banerjee, Kaushik; Dhumal, Kondiba N; Adsule, Pandurang G

    2011-01-01

    This paper describes single-laboratory validation of a multiresidue method for the determination of 135 pesticides, 12 dioxin-like polychlorinated biphenyls, 12 polyaromatic hydrocarbons, and bisphenol A in grapes and wine by GC/time-of-flight MS in a total run time of 48 min. The method is based on extraction with ethyl acetate in a sample-to-solvent ratio of 1:1, followed by selective dispersive SPE cleanup for grapes and wine. The GC/MS conditions were optimized for the chromatographic separation and to achieve highest S/N for all 160 target analytes, including the temperature-sensitive compounds, like captan and captafol, that are prone to degradation during analysis. An average recovery of 80-120% with RSD < 10% could be attained for all analytes except 17, for which the average recoveries were 70-80%. LOQ ranged within 10-50 ng/g, with < 25% expanded uncertainties, for 155 compounds in grapes and 151 in wine. In the incurred grape and wine samples, the residues of buprofezin, chlorpyriphos, metalaxyl, and myclobutanil were detected, with an RSD of < 5% (n = 6); the results were statistically similar to previously reported validated methods.

  5. Dispersal and survival of Flavobacterium psychrophilum phages in vivo in rainbow trout and in vitro under laboratory conditions: implications for their use in phage therapy.

    PubMed

    Madsen, Lone; Bertelsen, Sif K; Dalsgaard, Inger; Middelboe, Mathias

    2013-08-01

    Attention has been drawn to phage therapy as an alternative approach for controlling pathogenic bacteria such as Flavobacterium psychrophilum in salmonid aquaculture, which can give rise to high mortalities, especially in rainbow trout fry. Recently, phages have been isolated with a broad host range and a strong lytic potential against pathogenic F. psychrophilum under experimental conditions. However, little is known about the fate of phages at environmental conditions. Here, we quantified the dispersal and fate of F. psychrophilum phages and hosts in rainbow trout fry after intraperitoneal injection. Both phages and bacteria were isolated from the fish organs for up to 10 days after injection, and coinjection with both bacteria and phages resulted in a longer persistence of the phage in the fish organs, than when the fish had been injected with the phages only. The occurrence of both phage and bacterium was most prevalent in the kidney and spleen, with only minor occurrence in the brain. The experiment showed that injected phages were rapidly spread in the internal organs of the fish, also in the absence of bacteria. Parallel examination of the regulation of bacteriophage infectivity in controlled laboratory experiments at various environmental conditions showed that pH had only minor effects on long-term (3 months) phage infectivity within a pH range of 4.5 to 7.5, whereas phage infectivity was immediately lost at pH 3. In the absence of host cells, phage infectivity decreased by a factor of 10,000 over 55 days in untreated pond water, while the sterilization and removal of particles caused a 100-fold increase in phage survival relative to the control. In addition, F. psychrophilum-specific phages maintained their infectivity for ∼2 months in glycerol at -80°C, whereas infectivity decreased by a factor 10 when kept in a buffer at 20°C. Only a very small degradation in infectivity was seen when bacteriophages were added and dried on fish feed pellets

  6. Additive Similarity Trees

    ERIC Educational Resources Information Center

    Sattath, Shmuel; Tversky, Amos

    1977-01-01

    Tree representations of similarity data are investigated. Hierarchical clustering is critically examined, and a more general procedure, called the additive tree, is presented. The additive tree representation is then compared to multidimensional scaling. (Author/JKS)

  7. Exploration Laboratory Analysis FY13

    NASA Technical Reports Server (NTRS)

    Krihak, Michael; Perusek, Gail P.; Fung, Paul P.; Shaw, Tianna, L.

    2013-01-01

    The Exploration Laboratory Analysis (ELA) project supports the Exploration Medical Capability (ExMC) risk, which is stated as the Risk of Inability to Adequately Treat an Ill or Injured Crew Member, and ExMC Gap 4.05: Lack of minimally invasive in-flight laboratory capabilities with limited consumables required for diagnosing identified Exploration Medical Conditions. To mitigate this risk, the availability of inflight laboratory analysis instrumentation has been identified as an essential capability in future exploration missions. Mission architecture poses constraints on equipment and procedures that will be available to treat evidence-based medical conditions according to the Space Medicine Exploration Medical Conditions List (SMEMCL), and to perform human research studies on the International Space Station (ISS) that are supported by the Human Health and Countermeasures (HHC) element. Since there are significant similarities in the research and medical operational requirements, ELA hardware development has emerged as a joint effort between ExMC and HHC. In 2012, four significant accomplishments were achieved towards the development of exploration laboratory analysis for medical diagnostics. These achievements included (i) the development of high priority analytes for research and medical operations, (ii) the development of Level 1 functional requirements and concept of operations documentation, (iii) the selection and head-to-head competition of in-flight laboratory analysis instrumentation, and (iv) the phase one completion of the Small Business Innovation Research (SBIR) projects under the topic Smart Phone Driven Blood-Based Diagnostics. To utilize resources efficiently, the associated documentation and advanced technologies were integrated into a single ELA plan that encompasses ExMC and HHC development efforts. The requirements and high priority analytes was used in the selection of the four in-flight laboratory analysis performers. Based upon the

  8. [Effect of the probiotic Bacillus subtilis on the growth and food utilization of tilapia (Oreochromis niloticus) and prawn (Macrobrachium rosenbergii) under laboratory conditions].

    PubMed

    Günther, Jorge; Jiménez-Montealegre, Ricardo

    2004-12-01

    Three experiments were conducted to analyze the effect of the probiotic Bacillus subtilis on the growth of juvenile tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii). The experiments were conducted under laboratory conditions, minimizing the indirect effects of the probiotic on the water quality and leaving only the possible bactericidal and digestion-support effects. A model of stress was also designed in tilapia to compare the effect with tilapia under normal conditions. The dose in the food was 0.1% of the probiotic (5 x 10(8) CFU/g and 99.9 % maltrine) in the dry diet. Every 14 days the animals were weighed in group (tilapias +/- 0.1 g, prawns +/- 0.001 g) to estimate average body weight. In the first experiment (tilapia) the specific growth rate (SGR) and the feed conversion ratio (FCR) were bad in relation with the factor probiotic, but the differences were not significant. In the second experiment (tilapia) both the SGR and the FCR deteriorated with the addition of B. subtilis to the diet; the difference was significant to 94%. The stress factor, on the contrary, caused a notable worsening of both the growth and the food utilization. In the experiment with prawns the addition of B. subtilis caused a light deterioration of the growth and of the food utilization, with a statistical probability of mistake of 10% in case of the growth. During the experiment the direct effects over the digestive system should have prevailed, either by the contribution of macro- and micronutrients, or by the enzymes that contribute to the digestion. The negative effect due to the addition of the probiotic to the food was small (about 10% in both the SGR and the FCR) being difficult to detect statistically. The reports on the positive action of probiotics on the growth in aquatic animals have been conducted mainly in ponds, and our information does not contradict directly a possible positive action of B. subtilis in this type of systems. Since the

  9. Study of edge turbulence in dimensionally similar laboratory plasmas

    NASA Astrophysics Data System (ADS)

    Stroth, Ulrich

    2003-10-01

    In recent years, the numerical simulation of turbulence has made considerable progress. Predictions are made for large plasma volumes taking into account realistic magnetic geometries. Because of diagnostic limitations, in fusion plasmas the means of experimental testing of the models are rather limited. Toroidal low-temperature plasmas offer the possibility for detailed comparisons between experiment and simulation. Due to the reduced plasma parameters, the relevant quantities can be measured in the entire plasma. At the same time, the relevant non-dimensional parameters can be comparable to those in the edge of fusion plasmas. This presentation reports on results from the torsatron TJ-K [1,2] operated with a low-temperature plasma. The data are compared with simulations using the drift-Alfven-wave code DALF3 [3]. Langmuir probe arrays with 64 tips are used to measure the spatial structure of the turbulence. The same analyses techniques are applied to experimental and numerical data. The measured properties of spectra and probability density functions are reproduced by the code. Although the plasma in experiment and simulation does not exhibit critical pressure gradients, the radial transport fluctuations are strongly intermittent in both cases. Using Hydrogen, Helium and Argon as working gases, the scale parameter ρs could be varied by more than a factor of ten. As predicted by theory, the size of the turbulent eddies increases with ρ_s. The measured cross-phase between density and potential fluctuations are small, indicating the importance of the drift-wave dynamics for the turbulence in toroidal plasmas. The wave number spectra decay with an exponent of -3 as one would expect for the enstrophy cascade in 2D turbulence. [1] N. Krause et al., Rev. Sci. Instr. 73, 3474 (2002) [2] C. Lechte et al., New J. of Physics 4, 34 (2002) [3] B. Scott, Plasma Phys. Contr. Fusion 39, 1635 (1997)

  10. The Qualitative Similarity Hypothesis

    ERIC Educational Resources Information Center

    Paul, Peter V.; Lee, Chongmin

    2010-01-01

    Evidence is presented for the qualitative similarity hypothesis (QSH) with respect to children and adolescents who are d/Deaf or hard of hearing. The primary focus is on the development of English language and literacy skills, and some information is provided on the acquisition of English as a second language. The QSH is briefly discussed within…

  11. Characterization of XR-RV3 GafChromic{sup ®} films in standard laboratory and in clinical conditions and means to evaluate uncertainties and reduce errors

    SciTech Connect

    Farah, J. Clairand, I.; Huet, C.; Trianni, A.; Ciraj-Bjelac, O.; De Angelis, C.; Delle Canne, S.; Hadid, L.; Waryn, M. J.; Jarvinen, H.; Siiskonen, T.; Negri, A.; Novák, L.; Pinto, M.; Knežević, Ž.

    2015-07-15

    Purpose: To investigate the optimal use of XR-RV3 GafChromic{sup ®} films to assess patient skin dose in interventional radiology while addressing the means to reduce uncertainties in dose assessment. Methods: XR-Type R GafChromic films have been shown to represent the most efficient and suitable solution to determine patient skin dose in interventional procedures. As film dosimetry can be associated with high uncertainty, this paper presents the EURADOS WG 12 initiative to carry out a comprehensive study of film characteristics with a multisite approach. The considered sources of uncertainties include scanner, film, and fitting-related errors. The work focused on studying film behavior with clinical high-dose-rate pulsed beams (previously unavailable in the literature) together with reference standard laboratory beams. Results: First, the performance analysis of six different scanner models has shown that scan uniformity perpendicular to the lamp motion axis and that long term stability are the main sources of scanner-related uncertainties. These could induce errors of up to 7% on the film readings unless regularly checked and corrected. Typically, scan uniformity correction matrices and reading normalization to the scanner-specific and daily background reading should be done. In addition, the analysis on multiple film batches has shown that XR-RV3 films have generally good uniformity within one batch (<1.5%), require 24 h to stabilize after the irradiation and their response is roughly independent of dose rate (<5%). However, XR-RV3 films showed large variations (up to 15%) with radiation quality both in standard laboratory and in clinical conditions. As such, and prior to conducting patient skin dose measurements, it is mandatory to choose the appropriate calibration beam quality depending on the characteristics of the x-ray systems that will be used clinically. In addition, yellow side film irradiations should be preferentially used since they showed a lower

  12. Impact of the addition of different plant residues on nitrogen mineralization-immobilization turnover and carbon content of a soil incubated under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Kaleeem Abbasi, M.; Tahir, M. Mahmood; Sabir, N.; Khurshid, M.

    2015-02-01

    Application of plant residues as soil amendment may represent a valuable recycling strategy that affects carbon (C) and nitrogen (N) cycling in soil-plant systems. The amount and rate of nutrient release from plant residues depend on their quality characteristics and biochemical composition. A laboratory incubation experiment was conducted for 120 days under controlled conditions (25 °C and 58% water-filled pore space) to quantify initial biochemical composition and N mineralization of leguminous and non-leguminous plant residues, i.e., the roots, shoots and leaves of Glycine max, Trifolium repens, Zea mays, Populus euramericana, Robinia pseudoacacia and Elaeagnus umbellata, incorporated into the soil at the rate of 200 mg residue N kg-1 soil. The diverse plant residues showed a wide variation in total N, C, lignin, polyphenols and C / N ratio with higher polyphenol content in the leaves and higher lignin content in the roots. The shoot of Glycine max and the shoot and root of Trifolium repens displayed continuous mineralization by releasing a maximum of 109.8, 74.8 and 72.5 mg N kg-1 and representing a 55, 37 and 36% recovery of N that had been released from these added resources. The roots of Glycine max and Zea mays and the shoot of Zea mays showed continuous negative values throughout the incubation. After an initial immobilization, leaves of Populus euramericana, Robinia pseudoacacia and Elaeagnus umbellata exhibited net mineralization by releasing a maximum of 31.8, 63.1 and 65.1 mg N kg-1, respectively, and representing a 16, 32 and 33% N recovery, respectively. Nitrogen mineralization from all the treatments was positively correlated with the initial residue N contents (r = 0.89; p ≤ 0.01) and negatively correlated with lignin content (r = -0.84; p ≤ 0.01), C / N ratio (r = -0.69; p ≤ 0.05), lignin / N ratio (r = -0.68; p ≤ 0.05), polyphenol / N ratio (r = -0.73; p ≤ 0.05) and (lignin + polyphenol) : N ratio (r = -0.70; p ≤ 0.05) indicating a

  13. Impact of the addition of different plant residues on carbon-nitrogen content and nitrogen mineralization-immobilization turnover in a soil incubated under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Abbasi, M. K.; Tahir, M. M.; Sabir, N.; Khurshid, M.

    2014-10-01

    Application of plant residues as soil amendment may represent a valuable recycling strategy that affects on carbon (C) and nitrogen (N) cycling, soil properties improvement and plant growth promotion. The amount and rate of nutrient release from plant residues depend on their quality characteristics and biochemical composition. A laboratory incubation experiment was conducted for 120 days under controlled conditions (25 °C and 58% water filled pore space (WFPS)) to quantify initial biochemical composition and N mineralization of leguminous and non-leguminous plant residues i.e. the roots, shoots and leaves of Glycine max, Trifolium repens, Zea mays, Poplus euramericana, Rubinia pseudoacacia and Elagnus umbellate incorporated into the soil at the rate of 200 mg residue N kg-1 soil. The diverse plant residues showed wide variation in total N, carbon, lignin, polyphenols and C/N ratio with higher polyphenol content in the leaves and higher lignin content in the roots. The shoot of G. max and the shoot and root of T. repens displayed continuous mineralization by releasing a maximum of 109.8, 74.8 and 72.5 mg N kg-1 and representing a 55, 37 and 36% of added N being released from these resources. The roots of G. max and Z. mays and the shoot of Z. mays showed continuous negative values throughout the incubation showing net immobilization. After an initial immobilization, leaves of P. euramericana, R. pseudoacacia and E. umbellate exhibited net mineralization by releasing a maximum of 31.8, 63.1 and 65.1 mg N kg-1, respectively and representing a 16, 32 and 33% of added N being released. Nitrogen mineralization from all the treatments was positively correlated with the initial residue N contents (r = 0.89; p ≤ 0.01), and negatively correlated with lignin content (r = -0.84; p ≤ 0.01), C/N ratio (r = -0.69; p ≤ 0.05), lignin/N ratio (r = -0.68; p ≤ 0.05), polyphenol/N ratio (r = -0.73; p ≤ 0.05) and ligin + polyphenol/N ratio (r = -0.70; p ≤ 0.05) indicating

  14. Racism and Sexism: Similarities.

    ERIC Educational Resources Information Center

    Schetlin, Elanor M.

    1979-01-01

    Criticizes racism and sexism. Women and ethnic minority men face incongenial conditions when working in organizations dominated by White males. Understanding the treatment accorded women and ethnic minority men may facilitate the spread of democracy to include these latter groups and lead to a concerted attack on racism and sexism. (Author/BEF)

  15. Similar enzymes, different structures

    PubMed Central

    Tarasev, Michael; Kaddis, Catherine S.; Yin, Sheng; Loo, Joseph A.; Burgner, John; Ballou, David P.

    2007-01-01

    Phthalate dioxygenase (PDO) is a member of a class of bacterial oxygenases that contain both Rieske [2Fe-2S] and Fe(II) mononuclear centers. Recent crystal structures of several Rieske dioxygenases showed that they exist as α3β3 multimers with subunits arranged head-to-tail in α and β stacked planar consists of only α-subunits, remains to be solved. Although similar to other Rieske dioxygenases in many aspects, PDO was shown to differ in the mechanism of catalysis. Gel filtration and analytical centrifugation experiments, supplemented with mass spectrometric analysis (both ESI-MS and ESI-GEMMA), in this work showed a hexameric arrangement of subunits in the PDO multimer. Our proposed model for the subunit arrangement in PDO postulates two α3 planar rings one on top the other, similar to the α3β3 arrangement in other Rieske dioxygenases. Unlike other Rieske dioxygenases, this arrangement brings two Rieske and two mononuclear centers, all on separate subunits, into proximity, allowing their cooperation for catalysis. Potential reasons necessitating this unusual structural arrangement are discussed. PMID:17764654

  16. Laboratory Astrochemistry: Interstellar PAH Analogs

    NASA Technical Reports Server (NTRS)

    Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a

  17. An update of hydrologic conditions and distribution of selected constituents in water, Snake River Plain aquifer, Idaho National Laboratory, Idaho, Emphasis 1999-2001

    USGS Publications Warehouse

    Davis, Linda C.

    2006-01-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds, evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the Snake River Plain aquifer underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from wells in the USGS ground-water monitoring networks during 1999-2001. Water in the Snake River Plain aquifer moves principally through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged principally from infiltration of irrigation water, infiltration of streamflow, ground-water inflow from adjoining mountain drainage basins, and infiltration of precipitation. Water levels in wells rose in the northern and west-central parts of the INL by 1 to 3 feet, and declined in the southwestern parts of the INL by up to 4 feet during 1999-2001. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 1999-2001. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge. Tritium concentrations in water samples decreased as much as 8.3 picocuries per milliliter (pCi/mL) during 1999-2001, ranging from 0.43?0.14 to 13.6?0.6 pCi/mL in October 2001. Tritium concentrations in five wells near the Idaho Nuclear Technology and Engineering Center (INTEC) increased a few picocuries per milliliter from October 2000 to October 2001. Strontium-90 concentrations decreased or remained

  18. Laboratory Tests

    MedlinePlus

    Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor ... compare your results to results from previous tests. Laboratory tests are often part of a routine checkup ...

  19. Similar outcome after allogeneic stem cell transplantation with a modified FLAMSA conditioning protocol substituting 4 Gy TBI with treosulfan in an elderly population with high-risk AML.

    PubMed

    Holtick, Udo; Herling, Marco; Pflug, Natali; Chakupurakal, Geothy; Leitzke, Silke; Wolf, Dominik; Hallek, Michael; Scheid, Christof; Chemnitz, Jens M

    2017-03-01

    The fludarabine, amsacrine, and cytarabine (FLAMSA)-reduced-intensity conditioning (RIC) protocol has been described to be effective in patients with high-risk and refractory acute myeloic leukemia (AML) undergoing allogeneic hematopoietic stem cell transplantation (aSCT). To increase safety and tolerability of the conditioning, we previously reported the feasibility to substitute the TBI component by treosulfan in elderly AML patients. We now present long-term follow-up data on patients treated with FLAMSA/treosulfan compared to the original FLAMSA/4Gy TBI protocol. We retrospectively analyzed 130 consecutive patients with high-risk or relapsed AML after aSCT following FLAMSA conditioning at our center. Fifty-eight patients were treated with FLAMSA/treosulfan due to age and/or comorbidities. Seventy-two patients were treated with FLAMSA/TBI. Median age of patients treated with FLAMSA/treosulfan was 60 years compared to 46 years in those treated with FLAMSA/TBI. The cumulative incidence of a non-relapse mortality at 4 years was 28% in FLAMSA/treosulfan patients as compared to 13% in FLAMSA/TBI. Cumulative incidence of relapse was higher in patients treated with FLAMSA/TBI (46 vs. 32%). This difference was even more prominent for patients treated in blast persistence prior to transplant (relapse incidence 70% for TBI vs. 35% for treosulfan). The overall and relapse-free survival rates at 4 years were 47 and 41%, respectively, for patients treated with FLAMSA/TBI as compared to 43 and 40% in patients treated with FLAMSA/treosulfan. These data indicate an anti-leukemic activity by FLAMSA/treosulfan especially in patients with a blast persistence prior to transplant. Older age was an independent factor for a higher non-relapse mortality. Translating FLAMSA/treosulfan to younger patients, a lower non-relapse mortality, and an improved anti-leukemic activity might add up to improved overall survival. Randomized studies are required to demonstrate an improved efficacy

  20. Heat transfer in geometrically similar cylinders

    NASA Technical Reports Server (NTRS)

    Riekert, P; Held, A

    1941-01-01

    The power and heat-stress conditions of geometrically similar engines are discussed. The advantages accruing from smaller cylinder dimensions are higher specific horsepower, lower weight per horsepower, lower piston temperature, and less frontal area, with reduced detonation tendency.

  1. Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1992 through 1995

    SciTech Connect

    Bartholomay, R.C.; Tucker, B.J.; Ackerman, D.J.; Liszewski, M.J.

    1997-04-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The US Geological Survey, in cooperation with the US Department of Energy, maintains a monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1992--95.

  2. Knockdown and mortality comparisons among spinosad-, imidacloprid-, and methomyl-containing baits against susceptible Musca domestica (Diptera: Muscidae) under laboratory conditions.

    PubMed

    White, W Hunter; McCoy, Christine M; Meyer, Jeffery A; Winkle, Joseph R; Plummer, Philip R; Kemper, Connie J; Starkey, Robert; Snyder, Daniel E

    2007-02-01

    The activity of spinosad, imidacloprid, and methomyl baits and technical actives were assessed against susceptible house flies, Musca domestica L. (Diptera: Muscidae). In a feeding assay, imidacloprid affected flies more rapidly than methomyl or spinosad, but spinosad was 2.7 times more potent than methomyl and 8 times more potent than imidacloprid. The profile of technical actives correlated with their respective fly bait formulations in laboratory assays. Although having the most rapid onset of activity in laboratory tests, up to 50% of flies remained alive after exposure to imidacloprid bait. In contrast, <5% of flies survived 24-h exposure to spinosad or methomyl baits. High temperature reduced the knockdown activity of imidacloprid bait and slowed the speed of kill for spinosad and methomyl baits over a 24-h exposure period. Spinosad and methomyl baits were also superior to imidacloprid when applied to the floors of environmentally controlled rooms at label recommended rates, providing good fly control for up to 21 d. The fact that a significant percentage of flies exposed to imidacloprid were rapidly knocked down but subsequently remained alive in all of the assays suggested that flies were recovering from initial exposure to this compound. Given its favorable safety profile, a high degree of initial and residual activity comparable with methomyl and lack of cross-resistance to other chemistries, spinosad bait may be a valuable component of house fly control programs to help control or delay the emergence of resistant populations.

  3. Similarity effects in visual working memory.

    PubMed

    Jiang, Yuhong V; Lee, Hyejin J; Asaad, Anthony; Remington, Roger

    2016-04-01

    Perceptual similarity is an important property of multiple stimuli. Its computation supports a wide range of cognitive functions, including reasoning, categorization, and memory recognition. It is important, therefore, to determine why previous research has found conflicting effects of inter-item similarity on visual working memory. Studies reporting a similarity advantage have used simple stimuli whose similarity varied along a featural continuum. Studies reporting a similarity disadvantage have used complex stimuli from either a single or multiple categories. To elucidate stimulus conditions for similarity effects in visual working memory, we tested memory for complex stimuli (faces) whose similarity varied along a morph continuum. Participants encoded 3 morphs generated from a single face identity in the similar condition, or 3 morphs generated from different face identities in the dissimilar condition. After a brief delay, a test face appeared at one of the encoding locations for participants to make a same/different judgment. Two experiments showed that similarity enhanced memory accuracy without changing the response criterion. These findings support previous computational models that incorporate featural variance as a component of working memory load. They delineate limitations of models that emphasize cortical resources or response decisions.

  4. Research on the Error Characteristics of a 110 kV Optical Voltage Transformer under Three Conditions: In the Laboratory, Off-Line in the Field and During On-Line Operation

    PubMed Central

    Xiao, Xia; Hu, Haoliang; Xu, Yan; Lei, Min; Xiong, Qianzhu

    2016-01-01

    Optical voltage transformers (OVTs) have been applied in power systems. When performing accuracy performance tests of OVTs large differences exist between the electromagnetic environment and the temperature variation in the laboratory and on-site. Therefore, OVTs may display different error characteristics under different conditions. In this paper, OVT prototypes with typical structures were selected to be tested for the error characteristics with the same testing equipment and testing method. The basic accuracy, the additional error caused by temperature and the adjacent phase in the laboratory, the accuracy in the field off-line, and the real-time monitoring error during on-line operation were tested. The error characteristics under the three conditions—laboratory, in the field off-line and during on-site operation—were compared and analyzed. The results showed that the effect of the transportation process, electromagnetic environment and the adjacent phase on the accuracy of OVTs could be ignored for level 0.2, but the error characteristics of OVTs are dependent on the environmental temperature and are sensitive to the temperature gradient. The temperature characteristics during on-line operation were significantly superior to those observed in the laboratory. PMID:27537895

  5. Mechanisms for similarity based cooperation

    NASA Astrophysics Data System (ADS)

    Traulsen, A.

    2008-06-01

    Cooperation based on similarity has been discussed since Richard Dawkins introduced the term “green beard” effect. In these models, individuals cooperate based on an aribtrary signal (or tag) such as the famous green beard. Here, two different models for such tag based cooperation are analysed. As neutral drift is important in both models, a finite population framework is applied. The first model, which we term “cooperative tags” considers a situation in which groups of cooperators are formed by some joint signal. Defectors adopting the signal and exploiting the group can lead to a breakdown of cooperation. In this case, conditions are derived under which the average abundance of the more cooperative strategy exceeds 50%. The second model considers a situation in which individuals start defecting towards others that are not similar to them. This situation is termed “defective tags”. It is shown that in this case, individuals using tags to cooperate exclusively with their own kind dominate over unconditional cooperators.

  6. Thermal Performance of Biological Substance Systems in Vitro Under Static and Dynamic Conditions at the Cryogenic Test Laboratory, NASA Kennedy Space Center, USA

    NASA Technical Reports Server (NTRS)

    Augustynowicz, S. D.; Fesmire, James E.; Steinrock, T. (Technical Monitor)

    2001-01-01

    A unique research program, including a comprehensive study of thermal performance at cryogenic vacuum insulation systems, was performed at the NASA Kennedy Space Center. The main goal was to develop a new soft vacuum system (from 1 torr to 10 torr) that provides an intermediate level of performance (k-value below 4.8 mW/m-K). Liquid nitrogen boil-off methods were used to test conventional materials, novel materials, and certain combinations. The test articles included combinations of aluminum foil, fiberglass paper, polyester fabric, silica aerogel composite blanket, fumed silica, silica aerogel powder, and syntactic foam. A new LCI system was developed at the Cryogenics Test Laboratory. This system performs exceptionally well at soft vacuum levels and nearly as good as an MLI at high vacuum levels. Apparent thermal conductivities for the LCI range from 2 mW/m-K at soft vacuum to 0.1 mW/m-K at high vacuum. Several cryostats were designed, constructed, and calibrated by the Cryogenics Test Laboratory at KSC NASA as part of this research program. The cryostat test apparatus is a liquid nitrogen boil-off calorimeter system for direct measurement of the apparent thermal conductivity at a fixed vacuum level between 5 x 10(exp -5) and 760 torr. The apparatus is also used for transient measurements of temperature profiles. The development of efficient, robust cryogenic insulation systems has been a targeted area of research for a number of years. Improved methods of characterization, testing, and evaluation of complex biological substance systems for cryosurgery and cryobiology are the focus of this paper.

  7. Predation and control efficacies of Misgurnus mizolepis (Cypriniformes: Cobitidae) toward Culex pipiens molestus (Diptera: Culicidae) and fish toxicity of temephos in laboratory and septic tank conditions.

    PubMed

    Chae, Seong Chun; Kwon, Young Hyun; Min, Kyung Il; Kim, Hyung Soo; Kim, Nam-Jin; Kim, Jun-Ran; Son, Bong Gi; Ahn, Young-Joon

    2014-07-01

    Culex pipiens molestus Forskal (Diptera: Culicidae) is the dominant mosquito species in septic tanks in South Korea. An assessment was made of the biological control potential of mud loaches, Misgurnus mizolepis Günther (Cypriniformes: Cobitidae), toward Cx. p. molestus larvae in laboratory and septic tanks. Results were compared with those of temephos 20% emulsifiable concentrate. In laboratory tests, all mud loaches survived on sedimentation chamber- and effluent chamber-collected water of aerobic septic tanks (ASTs), whereas all mud loaches died within 3-12 h after introduction into sedimentation chamber- and effluent chamber-collected water of anaerobic septic tanks, Gill hyperplasia and hemorrhages at the bases of pectoral fins were detected in all dead mud loaches. These appeared to have been caused by bacterial disease, rather than the physical and chemical characteristics of the septic tank water. A mud loach consumed an average range of 1,072-1,058 larvae of Cx. p. molestus in the AST water at 24 h. At the manufacturer's recommended rate (10 ml/ton) in the AST water, the temephos formulation did not cause fish mortality. In the AST experiment, predation of mosquito larvae by mud loaches at a release rate of one fish per 900 mosquito larvae resulted in complete mosquito control from the third day after treatment throughout the 18-wk survey period, compared with temephos 20% emulsifiable concentrate-treated AST water (reduction rate, 40% at 28 days after treatment). Reasonable mosquito control in aerobic septic tanks can be achieved by mosquito breeding season stocking of a rate of one mud loach per 900 mosquito larvae.

  8. Laboratory Building

    SciTech Connect

    Herrera, Joshua M.

    2015-03-01

    This report is an analysis of the means of egress and life safety requirements for the laboratory building. The building is located at Sandia National Laboratories (SNL) in Albuquerque, NM. The report includes a prescriptive-based analysis as well as a performance-based analysis. Following the analysis are appendices which contain maps of the laboratory building used throughout the analysis. The top of all the maps is assumed to be north.

  9. Exploration Laboratory Analysis - ARC

    NASA Technical Reports Server (NTRS)

    Krihak, Michael K.; Fung, Paul P.

    2012-01-01

    The Exploration Laboratory Analysis (ELA) project supports the Exploration Medical Capability (ExMC) risk, Risk of Inability to Adequately Treat an Ill or Injured Crew Member, and ExMC Gap 4.05: Lack of minimally invasive in-flight laboratory capabilities with limited consumables required for diagnosing identified Exploration Medical Conditions. To mitigate this risk, the availability of inflight laboratory analysis instrumentation has been identified as an essential capability in future exploration missions. Mission architecture poses constraints on equipment and procedures that will be available to treat evidence-based medical conditions according to the Space Medicine Exploration Medical Conditions List (SMEMCL). The SMEMCL provided diagnosis and treatment for the evidence-based medical conditions and hence, a basis for developing ELA functional requirements.

  10. Generative Models for Similarity-based Classification

    DTIC Science & Technology

    2007-01-01

    problem of estimating the class-conditional similarity probability models is solved by applying the maximum entropy principle, under the constraint that...model. The SDA class-conditional probability models have exponential form, because they are derived as the maximum entropy distribu- tions subject to...exist because the constraints are based on the data. As prescribed by Jaynes’ principle of maximum entropy [34], a unique class- conditional joint

  11. Geochemical and mineralogical characterization of the Arbuckle aquifer with laboratory flow cell experiments under supercritical conditions: Implications for CO2 sequestration

    NASA Astrophysics Data System (ADS)

    Barker, R. L.; Watney, W. L.; Bhattacharya, S.; Strazisar, B. R.; Kelly, L.; Ford, S. K.; Datta, S.

    2011-12-01

    The deep saline aquifer in south-central Kansas has been proposed as a potential site for geologic storage for CO2. Two wells (KGS 1-32 and 1-28) have been drilled to the basement to provide data for a site specific determination of the storage potential of the Arbuckle. The entirety of the Arbuckle (~4100-5100 ft) was cored to provide rock samples for description and flow cell experiments. Initial examination of the formation rocks show heterogeneity throughout the core samples that makes evident the need for careful examination of the formation to ensure accurate geochemical modeling in determining the storage capacity and extent of mineralization within injection rocks. The dominant mineralogy in the proposed CO2 injection zone is dolomitic limestone with sporadic large cherty nodules. Presence of extensive vugs and micro fractures are common at some depths. Thin section and XRD data have provided the specific mineral assemblage of each core plug. Drill stem test water samples were collected from 8 depths throughout the aquifer to describe the changing chemistry of water with depth. Initial chemical analysis show a hyper saline brine (range~50,000 - 190,000 TDS) dominated by Cl, Na and Ca. Elemental ratios of Cl:Br, Na:Cl and Ca:Sr are what is expected of a typical saline aquifer system. The swabbed water from 4995 to 5020 ft gave a constant pH of 4.76 for the entire period of pumping and field results show high sulfate concentrations (>200 mg/L). Laboratory experiments carried out at the National Energy Technology Laboratory at formation temperatures and pressures using formation core plugs and collected brine to identify the major reaction that can be anticipated when supercritical CO2 is in place. Formation brine is injected into the core plugs and supercritical CO2 is added thereafter. The effluent is collected as a time series of 1, 3, 6, 12, 18, 24, 32, 48 and 72 hours and analyzed for major, trace elements and anions by ICP-OES and IC to see the chemical

  12. Identification and Characterization of Early Mission Phase Microorganisms Residing on the Mars Science Laboratory and Assessment of Their Potential to Survive Mars-like Conditions

    NASA Astrophysics Data System (ADS)

    Smith, Stephanie A.; Benardini, James N., III; Anderl, David; Ford, Matt; Wear, Emmaleen; Schrader, Michael; Schubert, Wayne; DeVeaux, Linda; Paszczynski, Andrzej; Childers, Susan E.

    2017-03-01

    Planetary protection is governed by the Outer Space Treaty and includes the practice of protecting planetary bodies from contamination by Earth life. Although studies are constantly expanding our knowledge about life in extreme environments, it is still unclear what the probability is for terrestrial organisms to survive and grow on Mars. Having this knowledge is paramount to addressing whether microorganisms transported from Earth could negatively impact future space exploration. The objectives of this study were to identify cultivable microorganisms collected from the surface of the Mars Science Laboratory, to distinguish which of the cultivable microorganisms can utilize energy sources potentially available on Mars, and to determine the survival of the cultivable microorganisms upon exposure to physiological stresses present on the martian surface. Approximately 66% (237) of the 358 microorganisms identified are related to members of the Bacillus genus, although surprisingly, 22% of all isolates belong to non-spore-forming genera. A small number could grow by reduction of potential growth substrates found on Mars, such as perchlorate and sulfate, and many were resistant to desiccation and ultraviolet radiation (UVC). While most isolates either grew in media containing ≥10% NaCl or at 4°C, many grew when multiple physiological stresses were applied. The study yields details about the microorganisms that inhabit the surfaces of spacecraft after microbial reduction measures, information that will help gauge whether microorganisms from Earth pose a forward contamination risk that could impact future planetary protection policy.

  13. Migratory-stage sea lamprey Petromyzon marinus stop responding to conspecific damage-released alarm cues after 4 h of continuous exposure in laboratory conditions

    USGS Publications Warehouse

    Imre, Istvan; Di Rocco, Richard T.; McClure, Haley; Johnson, Nicholas; Brown, Grant E.

    2016-01-01

    This study investigated the length of avoidance response of migratory-stage sea lamprey Petromyzon marinus exposed continuously to conspecific damage-released alarm cues for varying lengths of time in laboratory stream channels. Ten replicate groups of P. marinus, separated by sex, were exposed to either deionized water control or to P. marinus extract for 0, 2 or 4 h continuously. Petromyzon marinus maintained their avoidance response to the conspecific damage-released alarm cue after continuous exposure to the alarm cue for 0 and 2 h but not 4 h. Beyond being one of the first studies in regards to sensory–olfactory adaptation–acclimation of fishes to alarm cues of any kind, these results have important implications for use of conspecific alarm cues in P. marinus control. For example, continuous application of conspecific alarm cue during the day, when P. marinus are inactive and hiding, may result in sensory adaptation to the odour by nightfall when they migrate upstream.

  14. Chemical evolution of organic molecules under Mars-like UV radiation conditions simulated in the laboratory with the “Mars organic molecule irradiation and evolution” (MOMIE) setup

    NASA Astrophysics Data System (ADS)

    Poch, O.; Noblet, A.; Stalport, F.; Correia, J. J.; Grand, N.; Szopa, C.; Coll, P.

    2013-09-01

    Understanding the evolution of organic matter on Mars is a major goal to drive and discuss past, present and future in situ analyses. Here we demonstrate the ability of the MOMIE (for Mars organic molecules irradiation and evolution) laboratory device in giving both in situ qualitative and quantitative data on the evolution of organic molecules under simulated Martian surface ultraviolet light (190-400 nm), mean temperature (218±2 K) and pressure (6±1 mbar). We describe the chemical evolution of glycine, an amino acid, which is very rapidly processed when exposed to direct ultraviolet radiations, with a molecular half-life of 231±110 h on Mars consistent with existing results. Moreover we report the first tentative detection of peptide bond formation activated by UV radiation reaching the Mars surface. We show that organics as simple as glycine could experience multiple chemical pathways at Mars, both in the solid and gaseous phase. Finally, we derive the quantum efficiency for the photodestruction of glycine of 2.18±1.45×10-3 molecule photon-1 in the 200-250 nm wavelength range. This value is significantly higher than previous estimates done by methane evolved measurements. Current and future studies performed with this simulation setup could produce kinetic and chemical insights into the evolution of organics on Mars.

  15. Identification and Characterization of Early Mission Phase Microorganisms Residing on the Mars Science Laboratory and Assessment of Their Potential to Survive Mars-like Conditions.

    PubMed

    Smith, Stephanie A; Benardini, James N; Anderl, David; Ford, Matt; Wear, Emmaleen; Schrader, Michael; Schubert, Wayne; DeVeaux, Linda; Paszczynski, Andrzej; Childers, Susan E

    2017-03-01

    Planetary protection is governed by the Outer Space Treaty and includes the practice of protecting planetary bodies from contamination by Earth life. Although studies are constantly expanding our knowledge about life in extreme environments, it is still unclear what the probability is for terrestrial organisms to survive and grow on Mars. Having this knowledge is paramount to addressing whether microorganisms transported from Earth could negatively impact future space exploration. The objectives of this study were to identify cultivable microorganisms collected from the surface of the Mars Science Laboratory, to distinguish which of the cultivable microorganisms can utilize energy sources potentially available on Mars, and to determine the survival of the cultivable microorganisms upon exposure to physiological stresses present on the martian surface. Approximately 66% (237) of the 358 microorganisms identified are related to members of the Bacillus genus, although surprisingly, 22% of all isolates belong to non-spore-forming genera. A small number could grow by reduction of potential growth substrates found on Mars, such as perchlorate and sulfate, and many were resistant to desiccation and ultraviolet radiation (UVC). While most isolates either grew in media containing ≥10% NaCl or at 4°C, many grew when multiple physiological stresses were applied. The study yields details about the microorganisms that inhabit the surfaces of spacecraft after microbial reduction measures, information that will help gauge whether microorganisms from Earth pose a forward contamination risk that could impact future planetary protection policy. Key Words: Planetary protection-Spore-Bioburden-MSL-Curiosity-Contamination-Mars. Astrobiology 17, 253-265.

  16. Emissions and climate-relevant optical properties of pollutants emitted from a three-stone fire and the Berkeley-Darfur stove tested under laboratory conditions.

    PubMed

    Preble, Chelsea V; Hadley, Odelle L; Gadgil, Ashok J; Kirchstetter, Thomas W

    2014-06-03

    Cooking in the developing world generates pollutants that endanger the health of billions of people and contribute to climate change. This study quantified pollutants emitted when cooking with a three-stone fire (TSF) and the Berkeley-Darfur Stove (BDS), the latter of which encloses the fire to increase fuel efficiency. The stoves were operated at the Lawrence Berkeley National Laboratory testing facility with a narrow range of fuel feed rates to minimize performance variability. Fast (1 Hz) measurements of pollutants enabled discrimination between the stoves' emission profiles and development of woodsmoke-specific calibrations for the aethalometer (black carbon, BC) and DustTrak (fine particles, PM2.5). The BDS used 65±5% (average±95% confidence interval) of the wood consumed by the TSF and emitted 50±5% of the carbon monoxide emitted by the TSF for an equivalent cooking task, indicating its higher thermal efficiency and a modest improvement in combustion efficiency. The BDS reduced total PM2.5 by 50% but achieved only a 30% reduction in BC emissions. The BDS-emitted particles were, therefore, more sunlight-absorbing: the average single scattering albedo at 532 nm was 0.36 for the BDS and 0.47 for the TSF. Mass emissions of PM2.5 and BC varied more than emissions of CO and wood consumption over all tests, and emissions and wood consumption varied more among TSF than BDS tests. The international community and the Global Alliance for Clean Cookstoves have proposed performance targets for the highest tier of cookstoves that correspond to greater reductions in fuel consumption and PM2.5 emissions of approximately 65% and 95%, respectively, compared to baseline cooking with the TSF. Given the accompanying decrease in BC emissions for stoves that achieve this stretch goal and BC's extremely high global warming potential, the short-term climate change mitigation from avoided BC emissions could exceed that from avoided CO2 emissions.

  17. Laboratory measurements of the microwave opacity and vapor pressure of sulfuric acid vapor under simulated conditions for the middle atmosphere of Venus

    NASA Technical Reports Server (NTRS)

    Steffes, P. G.

    1985-01-01

    Microwave absorption measurements at wavelengths of 13.4 and 3.6 cm were made in gaseous H2SO4 in a CO2 atmosphere under simulated conditions for the Venus middle atmosphere. The results suggest that abundances of gaseous H2SO4 on the order of 15-30 ppm could account for the absorption observed by radio occultation measurements at these wavelengths. They also imply that such abundances would correspond to saturation vapor pressure existing at or above the 46-48-km range, which correlates with the observed cloud base.

  18. Similarity increases altruistic punishment in humans.

    PubMed

    Mussweiler, Thomas; Ockenfels, Axel

    2013-11-26

    Humans are attracted to similar others. As a consequence, social networks are homogeneous in sociodemographic, intrapersonal, and other characteristics--a principle called homophily. Despite abundant evidence showing the importance of interpersonal similarity and homophily for human relationships, their behavioral correlates and cognitive foundations are poorly understood. Here, we show that perceived similarity substantially increases altruistic punishment, a key mechanism underlying human cooperation. We induced (dis)similarity perception by manipulating basic cognitive mechanisms in an economic cooperation game that included a punishment phase. We found that similarity-focused participants were more willing to punish others' uncooperative behavior. This influence of similarity is not explained by group identity, which has the opposite effect on altruistic punishment. Our findings demonstrate that pure similarity promotes reciprocity in ways known to encourage cooperation. At the same time, the increased willingness to punish norm violations among similarity-focused participants provides a rationale for why similar people are more likely to build stable social relationships. Finally, our findings show that altruistic punishment is differentially involved in encouraging cooperation under pure similarity vs. in-group conditions.

  19. Bioconcentration of two pharmaceuticals (benzodiazepines) and two personal care products (UV filters) in marine mussels (Mytilus galloprovincialis) under controlled laboratory conditions.

    PubMed

    Gomez, Elena; Bachelot, Morgane; Boillot, Clotilde; Munaron, Dominique; Chiron, Serge; Casellas, Claude; Fenet, Hélène

    2011-08-01

    Bioaccumulation is essential for gaining insight into the impact of exposure to organic micropollutants in aquatic fauna. Data are currently available on the bioaccumulation of persistent organic pollutants, but there is very little documentation on the bioaccumulation of pharmaceuticals and personal care products (PPCPs). The bioconcentration of selected PPCPs was studied in marine mussels (Mytilus galloprovincialis). The selected PPCPs were two organic UV filters, i.e., 2-ethylhexyl-4-trimethoxycinnamate (EHMC) and octocrylene (OC), and two benzodiazepines (BZP), i.e., diazepam (DZP) and tetrazepam (TZP). Laboratory experiments were performed in which M. galloprovincialis was exposed to these compounds either directly from water, for the less lipophilic substances (BZP) or via spiked food for lipophilic UV filters. M. galloprovincialis uptook and eliminated BZP following first-order kinetics. The biological half-life (t (1/2)) of TZP was 1.4 days, resulting in a bioconcentration factor of 64 and 99 mL g(-1) dry weight (dw), respectively, for 2.3 and 14.5 μg L(-1) of exposure, while the biological half-life (t (1/2)) of DZP was 0.4 days, resulting in a bioconcentration factor of 51 mL g(-1) dw for 13.2 μg L(-1) of exposure. The uptake of UV filter was rapid in mussels, followed by elimination within 24 h. EHMC increased from 15 to 138 ng g(-1) dw in 1 h and decreased to 25 ng g(-1) after 24 h for 11.9 μg L(-1) exposure. OC reached 839 ng g(-1) dw after 1 h and decreased to 33 ng g(-1) after 24 h for 11.6 μg L(-1) exposure. However, EHMC and OC were slightly accumulated in 48 h, i.e., 38 and 60 ng g(-1) dw, respectively.

  20. A similar shot to the previous image, this photograph, looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    A similar shot to the previous image, this photograph, looking northwest, provides a closer image of the brick penthouse and other devices - Department of Energy, Mound Facility, Electronics Laboratory Building (E Building), One Mound Road, Miamisburg, Montgomery County, OH

  1. Laboratory screening of potential predators of the poultry red mite (Dermanyssus gallinae) and assessment of Hypoaspis miles performance under varying biotic and abiotic conditions.

    PubMed

    Ali, W; George, D R; Shiel, R S; Sparagano, O A E; Guy, J H

    2012-06-08

    The poultry red mite, Dermanyssus gallinae (De Geer), is the most important ectoparasitic pest of layer hens worldwide and difficult to control through 'conventional' synthetic acaricides. The present study aimed to identify a suitable predator of D. gallinae that could potentially form the basis of biological control in commercial poultry systems. From four selected predatory mite species (Hypoaspis miles (Berlese), Hypoaspis aculeifer (Canestrini), Amblyseius degenerans (Berlese) and Phytoseiulus persimilis (Athias-Henriot)), Hypoaspis mites demonstrated the greatest potential as predators of D. gallinae. Experiments were also conducted to assess the effect of environmental (temperature and dust), physical (presence of harbourages) and biological (presence of alternative prey) factors on the predatory efficacy of H. miles. Predation of D. gallinae per se was observed under all conditions tested, though was found to be temperature-dependent and reduced by the presence of alternative prey.

  2. Degradation of indomethacin in river water under stress and non-stress laboratory conditions: degradation products, long-term evolution and adsorption to sediment.

    PubMed

    Jiménez, Juan J; Sánchez, María I; Pardo, Rafael; Muñoz, Beatriz E

    2017-01-01

    The pharmaceutical compound indomethacin is not totally removed in wastewater treatment plants, whose effluents flow into aquatic environments; concentrations in the 0.1-100ng/L range are commonly found in surface waters, and its fate is unknown. Here, biological, photochemical and thermal degradation assays were conducted under stress and non-stress conditions to estimate its degradation rate in river water and establish its degradation products over time. The results revealed that direct sunlight irradiation promoted the complete degradation of indomethacin (2μg/L) in less than 6hr, but indomethacin was detected over a period of 4months when water was kept under the natural day-night cycle and the exposure to sunlight was partially limited, as occurs inside a body of water. The biological degradation in water was negligible, while the hydrolysis at pH7.8 was slow. Residues were monitored by ultra-pressure liquid chromatography/quadrupole time-of-flight/mass spectrometry after solid-phase extraction, and six degradation products were found; their structures were proposed based on the molecular formulae and fragmentation observed in high-resolution tandem mass spectra. 4-Chlorobenzoic and 2-acetamido-5-methoxybenzoic acids were the long-term transformation products, persisting for at least 30weeks in water kept under non-stress conditions. Furthermore, the degradation in the presence of sediment was also monitored over time, with some differences being noted. The adsorption coefficients of indomethacin and degradation products on river sediment were calculated; long-term degradation products did not have significant adsorption to sediment.

  3. Laboratory accreditation.

    PubMed

    Bradway, D E; Siegelman, F L

    1994-09-01

    An investigation of alleged data fraud at a pesticide analytical laboratory led EPA to take a closer look at the Good Laboratory Practice (GLP) inspection program. There was special focus on changes which might be made in the program to enhance the chances of detecting fraud in regulated studies. To this end, the Assistant Administrator of the Office of Prevention, Pesticides and Toxic Substances (OPPTS) requested EPA's Office of Inspector General (OIG) to examine the GLP program. Several reports were issued by the OIG, including the recommendation that a laboratory accreditation program be adopted. EPA has been examining ways to implement the OIG's recommendations, including (1) laboratory accreditation consisting of three components: document submission and assessment, site visit and assessment, and proficiency assessment; and (2) mandatory registration of all facilities participating in GLP-regulated studies, based on document submission and assessment. These two alternatives are compared, and the advantages and disadvantages of each are discussed.

  4. [Comparative analysis of 3D data visibility of the prepared tooth finishing line on a synthetic jaw model, captured by international scanners in a laboratory conditions].

    PubMed

    Ryakhovsky, A N; Kostyukova, V V

    The aim of the study was to compare accuracy of digital impression's finishing line and the zone under it taken by different intraoral scanning systems. Parameters of comparison were: different level of the finishing line to the gingiva and width of sulcus after retraction. For this purpose two synthetic jaw models with prepared teeth were scanned using intraoral scanning systems: 3D Progress (MHT S.P.A., IT - MHT Optic Research AG, CH); True Definition (3M ESPE, USA); Trios (3Shape A/S, DNK); CEREC AC Bluecam, CEREC Omnicam (Sirona Dental System GmbH, DE); Planscan (Planmeca, FIN) (each n=10). Reference-scanning was done by ATOS Core (GOM mbH, DE). The resulting digital impressions were superimposed with the master-scan. The lowest measured deviations (trueness) for intraoral scanners, where the finishing line was 0.5 mm above gingiva were with scanner True Definition - 18.8±6.63 (on the finishing line) and 51.0±14.33 µm (0.3 mm under the finishing line). In conditions where finishing line was on the same level with gingiva, scanner Trios showed the best results: 17.0±3.96 and 52.7±6.52 µm. When the finishing line was 0.5 mm under gingiva, none of the testing scanners could visualize the zone 0.3 mm lower the finishing line. The best results for accuracy o the finishing line in that circumstances showed Trios: 15.1±5.05 µm. The optimum visualization of the finishing line and the zone under it was reached when the sulcus was 0.3 mm after retraction. Thus, the best accuracy was obtained with Trios: 10.3±2.69 (on the finishing line) and 57.2±13.58 µm (0.3 mm under finishing line). The results show that intraoral scanners also provide enough accuracy for indicating finishing line and the zone under it in different conditions of preparation and gingiva retraction. However, not all of the testing scanners can properly indicate finishing line and the zone under it when shoulder is below gingiva and the width of sulcus is less than 0.2 mm.

  5. FINAL REPORT - Biogeochemistry of Uranium Under Reducing and Re-oxidizing Conditions:An Integrated Laboratory and Field Study and Acceptable Endpoints for Metals and Radionuclides: Quantifying the Stability of Uranium and Lead Immobilized Under Sulfate Reducing Conditions

    SciTech Connect

    Brent Peyton; James Amonette; Haluk Beyenal; Gill Geesey; Zbigniew Lewandowski; Rajesh Sani

    2005-10-07

    Our understanding of subsurface microbiology is hindered by the inaccessibility of this environment, particularly when the hydrogeologic medium is contaminated with toxic substances. Research in our labs indicated that the composition of the growth medium (e.g., bicarbonate complexation of U(VI)) and the underlying mineral phase (e.g., hematite) significantly affects the rate and extent of U(VI) reduction and immobilization through a variety of effects. Our research was aimed at elucidating those effects to a much greater extent, while exploring the potential for U(IV) reoxidation and subsequent re-mobilization, which also appears to depend on the mineral phases present in the system. In situ coupons with a variety of mineral phases were placed in monitoring wells at the NABIR FRC. These coupons showed that the mineral phase composition significantly affected the resulting attached phase microbial community. Our comparative use of both batch and open flow reactors (more representative of field conditions) indicates that hydrodynamics and continual influx of substrate and contaminants can also yield significantly different results than those obtained with closed serum bottles. To this end, the following overall experimental hypothesis tested was the following: On a mineral surface under anaerobic conditions, accumulations of secondary inorganic precipitates are controlled by a) the bacteria associated with the mineral surface, b) the electron acceptors available for anaerobic bacterial respiration, and c) local hydrodynamics and pH buffers govern micro- and meso-scale interaction of U in the presence of electron donors and acceptors, and nutrients.

  6. An update of hydrologic conditions and distribution of selected constituents in water, Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2006-08

    USGS Publications Warehouse

    Davis, Linda C.

    2010-01-01

    Since 1952, radiochemical and chemical wastewater discharged to infiltration ponds (also called percolation ponds), evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched groundwater wells in the USGS groundwater monitoring networks during 2006-08. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2005 to March-May 2008, water levels in wells generally remained constant or rose slightly in the southwestern corner of the INL. Water levels declined in the central and northern parts of the INL. The declines ranged from about 1 to 3 feet in the central part of the INL, to as much as 9 feet in the northern part of the INL. Water levels in perched groundwater wells around the Advanced Test Reactor Complex (ATRC) also declined. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2006-08. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In April

  7. Retrospective clinical and molecular analysis of conditioned laboratory dogs (Canis familiaris) with serologic reactions to Ehrlichia canis, Borrelia burgdorferi, and Rickettsia rickettsii.

    PubMed

    Scorpio, Diana G; Wachtman, Lynn M; Tunin, Richard S; Barat, Nicole C; Garyu, Justin W; Dumler, J Stephen

    2008-09-01

    Dogs are susceptible to different tickborne infections, including members of the Anaplasmataceae (Ehrlichia canis, E. ewingii, E. chaffeensis, Anaplasma phagocytophilum, A. platys), Borrelia burgdorferi, and Rickettsia rickettsii. These diseases can manifest with clinical signs including fever, anorexia, malaise, lameness, rash, and bleeding episodes; however, these signs are nonpathognomonic, and infections can occur in the absence of clinical signs. Hematologic abnormalities can include leukopenia, thrombocytopenia, hyperproteinemia and hypergammaglobulinemia. In biomedical research, diseases such as canine monocytic ehrlichiosis, Lyme disease, and Rocky Mountain spotted fever may cause morbidity among exposed dogs and confound research results. Random-source dogs are susceptible to these diseases because of their increased risk of arthropod exposure. Nonpurpose bred, randomly selected conditioned dogs (n = 21) were examined; blood samples were taken for hematology, biochemistry analysis, tickborne pathogen serology, and PCR. Of these, 2 dogs (10% of the population) presented with illness characterized by fever, malaise, lameness, or hemostatic abnormalities, and 15 (71%) had antibodies to one or more tickborne pathogens. No specific hematologic or biochemical differences were apparent between seronegative dogs and seropositive dogs reactive to all 3 pathogens. E. canis and B. burgdorferi PCR of tissues and blood were negative for all dogs. PCR amplification of several Ehrlichia and Anaplasma genes yielded no positive samples. From this cohort of dogs, serologic and molecular results indicate prior exposure without active infection or clinical disease. Exposure to and potential for infection with these bacteria and other pathogens may contribute to blood and tissue alterations that could confound experiments and lead to misinterpretation of data in canine models.

  8. Rearing conditions and domestication background determine regulation of hippocampal cell proliferation and survival in adulthood-laboratory CD1 and C57Bl/6 mice versus wild house mice.

    PubMed

    Schaefers, A T U

    2013-01-03

    Brain development is sensitive to an individual's interaction with its environment. Deprivation of natural environmental stimulation especially in the phase after weaning has long-lasting consequences on neuroplasticity. However, previous findings concerning the effects of rearing environment on adult hippocampal cell proliferation and neurogenesis in rodents remain contradictory. To address the question, whether the variability of hippocampal plasticity in response to environmental conditions is a unique feature at least in mice, the present study examined the effects of social and physical deprivation during brain development on hippocampal cell production and survival in adults of three mouse strains (Mus musculus) with different domestication background: outbred CD1, inbred C57Bl/6 and the F2-descendants of wild-caught house mice. Wheel running increased cell proliferation rates in the dentate gyrus of CD1 and C57Bl/6 mice reared under socially and physically deprived conditions, but not from enriched conditions. In wild house mice, neither the rearing conditions nor the wheel-running challenge did affect proliferative activity. This indicates, on the one hand, that wild house mice are more robust in their regulation of hippocampal cell proliferation against environmental influences and, on the other hand, that domestication and rearing background of laboratory animals impact neuroplastic potentials and responsiveness to external stimuli in adulthood.

  9. Laboratory study of TLEs

    NASA Astrophysics Data System (ADS)

    Kochkin, P.; Van Deursen, A.; Ebert, U.

    2014-12-01

    Sprites are high-altitude kilometre-scale electrical discharges that happen above thundercloud. Pilot systems are pre-breakdown phenomena that usually attributed to stepped leader development. In Eindhoven University of Technology we investigate meter-scale laboratory discharges looking for similarities with natural lightning and its related phenomena. Negative lightning possesses step-like propagation behaviour which is associated with space leader formation in front of its main leader. Meter-scale laboratory sparks also develop via formation of a space stem that transforms into a pilot system and finally develops into a space leader in longer gaps. With ns-fast photography we investigated the pilot system formation and found striking similarities with high-altitude sprites. But sprites are different in size, environment and polarity. Laboratory pilot barely reaches 70 cm and develops in STP air, while high-altitude sprites reaches ionosphere stretching for dozens of kilometres. Also sprites are assumed to be of opposite to the pilot polarity. Besides that, the pilots are directly involved in x-ray generation in long laboratory sparks. The detailed pilot system development process will be shown, in particular focusing on similarities with natural sprites. Basic properties of the x-ray emission will be presented and discussed.

  10. Physiological and psychological responses to outdoor vs. laboratory cycling.

    PubMed

    Mieras, Molly E; Heesch, Matthew W S; Slivka, Dustin R

    2014-08-01

    The purpose of this study was to determine the physiological and psychological responses to laboratory vs. outdoor cycling. Twelve recreationally trained male cyclists participated in an initial descriptive testing session and 2 experimental trials consisting of 1 laboratory and 1 outdoor session, in a randomized order. Participants were given a standardized statement instructing them to give the same perceived effort for both the laboratory and outdoor 40-km trials. Variables measured include power output, heart rate (HR), core temperature, skin temperature, body weight, urine specific gravity (USG), Rating of Perceived Exertion (RPE), attentional focus, and environmental conditions. Wind speed was higher in the outdoor trial than in the laboratory trial (2.5 ± 0.6 vs. 0.0 ± 0.0 m·s-1, p = 0.02) whereas all other environmental conditions were similar. Power output (208.1 ± 10.2 vs. 163.4 ± 11.8 W, respectively, p < 0.001) and HR (152 ± 4 and 143 ± 6 b·min-1, respectively, p = 0.04) were higher in the outdoor trial than in the laboratory trial. Core temperature was similar, whereas skin temperature was cooler during the outdoor trial than during the laboratory trial (31.4 ± 0.3 vs. 33.0 ± 0.2° C, respectively, p < 0.001), thus creating a larger thermal gradient between the core and skin outdoors. No significant differences in body weight, USG, RPE, or attentional focus were observed between trials. These data indicate that outdoor cycling allows cyclists to exercise at a higher intensity than in laboratory cycling, despite similar environmental conditions and perceived exertion. In light of this, cyclists may want to ride at a higher perceived exertion in indoor settings to acquire the same benefit as they would from an outdoor ride.

  11. Learning similarity with multikernel method.

    PubMed

    Tang, Yi; Li, Luoqing; Li, Xuelong

    2011-02-01

    In the field of machine learning, it is a key issue to learn and represent similarity. This paper focuses on the problem of learning similarity with a multikernel method. Motivated by geometric intuition and computability, similarity between patterns is proposed to be measured by their included angle in a kernel-induced Hilbert space. Having noticed that the cosine of such an included angle can be represented by a normalized kernel, it can be said that the task of learning similarity is equivalent to learning an appropriate normalized kernel. In addition, an error bound is also established for learning similarity with the multikernel method. Based on this bound, a boosting-style algorithm is developed. The preliminary experiments validate the effectiveness of the algorithm for learning similarity.

  12. Similarity Learning of Manifold Data.

    PubMed

    Chen, Si-Bao; Ding, Chris H Q; Luo, Bin

    2015-09-01

    Without constructing adjacency graph for neighborhood, we propose a method to learn similarity among sample points of manifold in Laplacian embedding (LE) based on adding constraints of linear reconstruction and least absolute shrinkage and selection operator type minimization. Two algorithms and corresponding analyses are presented to learn similarity for mix-signed and nonnegative data respectively. The similarity learning method is further extended to kernel spaces. The experiments on both synthetic and real world benchmark data sets demonstrate that the proposed LE with new similarity has better visualization and achieves higher accuracy in classification.

  13. Discuss Similarity Using Visual Intuition

    ERIC Educational Resources Information Center

    Cox, Dana C.; Lo, Jane-Jane

    2012-01-01

    The change in size from a smaller shape to a larger similar shape (or vice versa) is created through continuous proportional stretching or shrinking in every direction. Students cannot solve similarity tasks simply by iterating or partitioning a composed unit, strategies typically used on numerical proportional tasks. The transition to thinking…

  14. Phonological similarity effect is abolished by a silent mouthing task.

    PubMed

    Saito, S

    1993-04-01

    This experiment was designed to examine the effect of silent mouthing on the phonological similarity effect. 16 undergraduates were tested for serial recall of visually presented letter sequences that were either phonologically similar or dissimilar. The letter sequences had to be remembered under two conditions, a control condition and a silent mouthing condition in which subjects had to articulate irrelevant words silently during the study period. Analysis showed the clear advantage of the dissimilar sequence over the similar one in the control condition. In contrast, this phonological similarity effect disappeared in the silent mouthing condition. This result is consistent with the working memory model.

  15. Laboratory diagnosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    One of the first major goals of the microbiology laboratory is to isolate or detect clinically significant microorganisms from an affected site and, if more than one type of microorganism is present, to isolate them in approximately the same ratio as occurs in vivo. Whether an isolate is “clinically...

  16. Optimal dynamic discrimination of similar quantum systems

    NASA Astrophysics Data System (ADS)

    Li, Baiqing

    2005-07-01

    The techniques for identifying and separating similar molecules have always been very important to chemistry and other branches of science and engineering. Similar quantum systems share comparable Hamiltonians, so their eigenenergy levels, transition dipole moments, and therefore their ordinary observable properties are alike. Traditional analytical methods have mostly been restricted by working with the subtle differences in the physical and chemical properties of the similar species. Optimal Dynamic Discrimination (ODD) aims at magnifying the dissimilarity of the agents by actively controlling their quantum evolution, drawing on the extremely rich information embedded in their dynamics. ODD is developed based on the tremendous flexibility of Optimal Control Theory (OCT) and on the practical implementation of closed-loop learning control, which has become a more and more indispensable tool for controlling quantum processes. The ODD experimental paradigm is designed to combat a number of factors that are detrimental to the discrimination of similar molecules: laser pulse noise, signal detection errors, finite time resolution in the signals, and environmental decoherence effects. It utilizes either static signals or time series signal, the latter capable of providing more information. Simulations are performed in this dissertation progressing from the wave function to the density matrix formulation, in order to study the decoherence effects. Analysis of the results reveals the roles of the adverse factors, unravels the underlying mechanisms of ODD, and provides insights on laboratory implementation. ODD emphasizes the incorporation of algorithmic development and laboratory design, and seeks to bridge the gap between theoretical/computational chemistry and experimental chemistry, with the help from applied mathematics and computer science.

  17. Towards personalized medicine: leveraging patient similarity and drug similarity analytics.

    PubMed

    Zhang, Ping; Wang, Fei; Hu, Jianying; Sorrentino, Robert

    2014-01-01

    The rapid adoption of electronic health records (EHR) provides a comprehensive source for exploratory and predictive analytic to support clinical decision-making. In this paper, we investigate how to utilize EHR to tailor treatments to individual patients based on their likelihood to respond to a therapy. We construct a heterogeneous graph which includes two domains (patients and drugs) and encodes three relationships (patient similarity, drug similarity, and patient-drug prior associations). We describe a novel approach for performing a label propagation procedure to spread the label information representing the effectiveness of different drugs for different patients over this heterogeneous graph. The proposed method has been applied on a real-world EHR dataset to help identify personalized treatments for hypercholesterolemia. The experimental results demonstrate the effectiveness of the approach and suggest that the combination of appropriate patient similarity and drug similarity analytics could lead to actionable insights for personalized medicine. Particularly, by leveraging drug similarity in combination with patient similarity, our method could perform well even on new or rarely used drugs for which there are few records of known past performance.

  18. Criteria for dynamic similarity in bouncing gaits.

    PubMed

    Bullimore, Sharon R; Donelan, J Maxwell

    2008-01-21

    Animals of different sizes tend to move in a dynamically similar manner when travelling at speeds corresponding to equal values of a dimensionless parameter (DP) called the Froude number. Consequently, the Froude number has been widely used for defining equivalent speeds and predicting speeds of locomotion by extinct species and on other planets. However, experiments using simulated reduced gravity have demonstrated that equality of the Froude number does not guarantee dynamic similarity. This has cast doubt upon the usefulness of the Froude number in locomotion research. Here we use dimensional analysis of the planar spring-mass model, combined with Buckingham's Pi-Theorem, to demonstrate that four DPs must be equal for dynamic similarity in bouncing gaits such as trotting, hopping and bipedal running. This can be reduced to three DPs by applying the constraint of maintaining a constant average speed of locomotion. Sensitivity analysis indicates that all of these DPs are important for predicting dynamic similarity. We show that the reason humans do not run in a dynamically similar manner at equal Froude number in different levels of simulated reduced gravity is that dimensionless leg stiffness decreases as gravity increases. The reason that the Froude number can predict dynamic similarity in Earth gravity is that dimensionless leg stiffness and dimensionless vertical landing speed are both independent of size. In conclusion, although equal Froude number is not sufficient for dynamic similarity, it is a necessary condition. Therefore, to detect fundamental differences in locomotion, animals of different sizes should be compared at equal Froude number, so that they can be as close to dynamic similarity as possible. More generally, the concept of dynamic similarity provides a powerful framework within which similarities and differences in locomotion can be interpreted.

  19. Renewing the respect for similarity.

    PubMed

    Edelman, Shimon; Shahbazi, Reza

    2012-01-01

    In psychology, the concept of similarity has traditionally evoked a mixture of respect, stemming from its ubiquity and intuitive appeal, and concern, due to its dependence on the framing of the problem at hand and on its context. We argue for a renewed focus on similarity as an explanatory concept, by surveying established results and new developments in the theory and methods of similarity-preserving associative lookup and dimensionality reduction-critical components of many cognitive functions, as well as of intelligent data management in computer vision. We focus in particular on the growing family of algorithms that support associative memory by performing hashing that respects local similarity, and on the uses of similarity in representing structured objects and scenes. Insofar as these similarity-based ideas and methods are useful in cognitive modeling and in AI applications, they should be included in the core conceptual toolkit of computational neuroscience. In support of this stance, the present paper (1) offers a discussion of conceptual, mathematical, computational, and empirical aspects of similarity, as applied to the problems of visual object and scene representation, recognition, and interpretation, (2) mentions some key computational problems arising in attempts to put similarity to use, along with their possible solutions, (3) briefly states a previously developed similarity-based framework for visual object representation, the Chorus of Prototypes, along with the empirical support it enjoys, (4) presents new mathematical insights into the effectiveness of this framework, derived from its relationship to locality-sensitive hashing (LSH) and to concomitant statistics, (5) introduces a new model, the Chorus of Relational Descriptors (ChoRD), that extends this framework to scene representation and interpretation, (6) describes its implementation and testing, and finally (7) suggests possible directions in which the present research program can be

  20. Renewing the respect for similarity

    PubMed Central

    Edelman, Shimon; Shahbazi, Reza

    2012-01-01

    In psychology, the concept of similarity has traditionally evoked a mixture of respect, stemming from its ubiquity and intuitive appeal, and concern, due to its dependence on the framing of the problem at hand and on its context. We argue for a renewed focus on similarity as an explanatory concept, by surveying established results and new developments in the theory and methods of similarity-preserving associative lookup and dimensionality reduction—critical components of many cognitive functions, as well as of intelligent data management in computer vision. We focus in particular on the growing family of algorithms that support associative memory by performing hashing that respects local similarity, and on the uses of similarity in representing structured objects and scenes. Insofar as these similarity-based ideas and methods are useful in cognitive modeling and in AI applications, they should be included in the core conceptual toolkit of computational neuroscience. In support of this stance, the present paper (1) offers a discussion of conceptual, mathematical, computational, and empirical aspects of similarity, as applied to the problems of visual object and scene representation, recognition, and interpretation, (2) mentions some key computational problems arising in attempts to put similarity to use, along with their possible solutions, (3) briefly states a previously developed similarity-based framework for visual object representation, the Chorus of Prototypes, along with the empirical support it enjoys, (4) presents new mathematical insights into the effectiveness of this framework, derived from its relationship to locality-sensitive hashing (LSH) and to concomitant statistics, (5) introduces a new model, the Chorus of Relational Descriptors (ChoRD), that extends this framework to scene representation and interpretation, (6) describes its implementation and testing, and finally (7) suggests possible directions in which the present research program can be

  1. The baryonic self similarity of dark matter

    SciTech Connect

    Alard, C.

    2014-06-20

    The cosmological simulations indicates that dark matter halos have specific self-similar properties. However, the halo similarity is affected by the baryonic feedback. By using momentum-driven winds as a model to represent the baryon feedback, an equilibrium condition is derived which directly implies the emergence of a new type of similarity. The new self-similar solution has constant acceleration at a reference radius for both dark matter and baryons. This model receives strong support from the observations of galaxies. The new self-similar properties imply that the total acceleration at larger distances is scale-free, the transition between the dark matter and baryons dominated regime occurs at a constant acceleration, and the maximum amplitude of the velocity curve at larger distances is proportional to M {sup 1/4}. These results demonstrate that this self-similar model is consistent with the basics of modified Newtonian dynamics (MOND) phenomenology. In agreement with the observations, the coincidence between the self-similar model and MOND breaks at the scale of clusters of galaxies. Some numerical experiments show that the behavior of the density near the origin is closely approximated by a Einasto profile.

  2. Thermoregulation during prolonged actual and laboratory-simulated bicycling.

    PubMed

    Brown, S L; Banister, E W

    1985-01-01

    Thermoregulatory and cardiorespiratory responses to bicycling 55 km (mean speed 9.7 m X s-1) outdoors (15 degrees C DB) were compared to equivalent cycle ergometry (90 min at 65% VO2max) in the laboratory (20-23 degrees C DB, 50% RH) in 7 trained cyclists. Outdoor environmental conditions were simulated with fans and lamps, and were contrasted with standard no-wind, no-sun laboratory conditions. Sweating rate was similar during outdoor and laboratory simulated outdoor cycling (0.90 and 0.87 to 0.94 1 X h-1 respectively). During outdoor bicycling, mean heart rate (161 bt X min-1) was 7-13% higher (p less than .05) than under laboratory conditions, suggesting a greater strain for a similar external work rate. The increase in rectal temperature (0.8 degrees C) was 33-50% less (p less than 0.05) at the cooler outdoor ambient temperature than in the laboratory. Thermoregulatory stress was greater under the no-fan, no-lamp laboratory condition than during simulated outdoor conditions (36-38% greater (p less than 0.05) sweating rate, 15-18% greater (p less than 0.01) mean skin temperature, 6.4 to 7.8 fold greater (p less than 0.01) amount of clothing-retrained sweat). The cooling wind encountered in actual road bicycling apparently reduces thermoregulatory and circulatory demands compared with stationary cycle ergometry indoors. Failure to account for this enhanced cooling may result in overestimation of the physiological stress of actual road cycling.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Growth of Corophium volutator under laboratory conditions.

    PubMed

    Kater, Belinda J; Jol, Johan G; Smit, Mathijs G D

    2008-04-01

    Temperature-dependent growth is an important factor in the population model of Corophium volutator that was developed to translate responses in a 10-day acute bioassay to ecological consequences for the population. The growth rate, however, was estimated from old data, based on a Swedish population. Therefore, new growth rates are estimated herein from two experiments using Corophium volutator. To save time, a tool was developed to use image analysis to measure Corophium volutator. The experiments show that Corophium volutator has a low growth rate at low temperatures (5-10 degrees C). At higher temperatures no difference in growth rate between 15 degrees C and 25 degrees C was found. The growth rate from these experiments is comparable to data found in literature. A new relationship between temperature and individual growth was estimated, and incorporated into the Corophium population model. As the model also uses the same temperature relationship for reproduction, the modelled population growth rate at different temperatures changes as a result of the new data. The new growth rate and the updated temperature relationship result in reduced tolerance to external stressors, as previously predicted by the model.

  4. Self-similar aftershock rates

    NASA Astrophysics Data System (ADS)

    Davidsen, Jörn; Baiesi, Marco

    2016-08-01

    In many important systems exhibiting crackling noise—an intermittent avalanchelike relaxation response with power-law and, thus, self-similar distributed event sizes—the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is particularly true for the case of seismicity, and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high-resolution earthquake data from Southern California we find excellent agreement, providing particularly clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved framework for time-dependent seismic hazard assessment and earthquake forecasting.

  5. Self-similar aftershock rates.

    PubMed

    Davidsen, Jörn; Baiesi, Marco

    2016-08-01

    In many important systems exhibiting crackling noise-an intermittent avalanchelike relaxation response with power-law and, thus, self-similar distributed event sizes-the "laws" for the rate of activity after large events are not consistent with the overall self-similar behavior expected on theoretical grounds. This is particularly true for the case of seismicity, and a satisfying solution to this paradox has remained outstanding. Here, we propose a generalized description of the aftershock rates which is both self-similar and consistent with all other known self-similar features. Comparing our theoretical predictions with high-resolution earthquake data from Southern California we find excellent agreement, providing particularly clear evidence for a unified description of aftershocks and foreshocks. This may offer an improved framework for time-dependent seismic hazard assessment and earthquake forecasting.

  6. Similarity of the Velocity Profile

    DTIC Science & Technology

    2014-10-01

    su x (with 0 constantb = ) is the empirically derived velocity scale developed by Zagarola and Smits [5] for turbulent boundary layer flow...Zagarola and Smits and others have shown that the velocity scaling factor given by Eq. 5 with sδ as the boundary layer thickness can collapse certain...and Smits , it is important to point out that the fact that the similarity length scale factor and the similarity velocity scale factor must follow