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. PMID:22531815

  3. 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.

  4. 9 CFR 327.19 - Specimens for laboratory examination and similar purposes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... and similar purposes. 327.19 Section 327.19 Animals and Animal Products FOOD SAFETY AND INSPECTION... laboratory examination and similar purposes. The provisions in this part do not apply to specimens of products for laboratory examination, research, or similar purposes when authorized importation by...

  5. 9 CFR 327.19 - Specimens for laboratory examination and similar purposes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Specimens for laboratory examination and similar purposes. 327.19 Section 327.19 Animals and Animal Products FOOD SAFETY AND INSPECTION... laboratory examination and similar purposes. The provisions in this part do not apply to specimens...

  6. 9 CFR 327.19 - Specimens for laboratory examination and similar purposes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Specimens for laboratory examination and similar purposes. 327.19 Section 327.19 Animals and Animal Products FOOD SAFETY AND INSPECTION... laboratory examination and similar purposes. The provisions in this part do not apply to specimens...

  7. 9 CFR 327.19 - Specimens for laboratory examination and similar purposes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Specimens for laboratory examination and similar purposes. 327.19 Section 327.19 Animals and Animal Products FOOD SAFETY AND INSPECTION... laboratory examination and similar purposes. The provisions in this part do not apply to specimens...

  8. 9 CFR 327.19 - Specimens for laboratory examination and similar purposes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Specimens for laboratory examination and similar purposes. 327.19 Section 327.19 Animals and Animal Products FOOD SAFETY AND INSPECTION... laboratory examination and similar purposes. The provisions in this part do not apply to specimens...

  9. Comparison of sexual compatibility between laboratory and wild Mexican fruit flies under laboratory and field conditions.

    PubMed

    Meza-Hernández, José Salvador; Díaz-Fleischer, Francisco

    2006-12-01

    The sexual compatibility between laboratory (LF) and wild (WF) strains of the Mexican fruit fly, Anastrepha ludens (Loew), was analyzed using analogous methodologies and experimental arenas under both laboratory and field conditions. Sexual compatibility was quantified with the following indices: the isolation index (ISI), male relative performance index (MRP), female relative performance index (FRPI), and the relative sterility index (RSI). ISI detected a certain level of incompatibility between strains under both laboratory and field conditions, because LF females tended to mate with LF males. LF mating performance was higher under laboratory than under field conditions. The relative performance indices for LF and the relative sterility index were higher in the laboratory than in the field. Differences between LF and WF in the times that males started calling and mating were observed in both environments. Importantly, WF males reduced their sexual activity under laboratory environments, whereas LF maintained similar activity levels in both conditions. The possible applications of the above-mentioned methods, not only to assess fly quality but also to determine the suitability of conditions in mass-rearing facilities, are discussed. Correlating laboratory quality to sexual behavior may contribute in the development of environmental parameters for mass-rearing facilities. PMID:17195663

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. Triangle Similarity. Geometry Module for Use in a Mathematics Laboratory Setting.

    ERIC Educational Resources Information Center

    Brotherton, Sheila; And Others

    This is one of a series of geometry modules developed for use by secondary students in a laboratory setting. The purpose of this module is to teach solution of proportions, concepts and theorems of triangle similarity, solution of the Pythagorean Theorem, solution of the isosceles right triangle, and concepts involving "rep-tile" figures as well…

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 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... Patient Care § 494.130 Condition: Laboratory services. The dialysis facility must provide, or make available, laboratory services (other than tissue pathology and histocompatibility) to meet the needs of...

  2. 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... Patient Care § 494.130 Condition: Laboratory services. The dialysis facility must provide, or make available, laboratory services (other than tissue pathology and histocompatibility) to meet the needs of...

  3. 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... Patient Care § 494.130 Condition: Laboratory services. The dialysis facility must provide, or make available, laboratory services (other than tissue pathology and histocompatibility) to meet the needs of...

  4. 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... Patient Care § 494.130 Condition: Laboratory services. The dialysis facility must provide, or make available, laboratory services (other than tissue pathology and histocompatibility) to meet the needs of...

  5. 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... Patient Care § 494.130 Condition: Laboratory services. The dialysis facility must provide, or make available, laboratory services (other than tissue pathology and histocompatibility) to meet the needs of...

  6. Authentication scheme for routine verification of genetically similar laboratory colonies: a trial with Anopheles gambiae

    PubMed Central

    Wilkins, Elien E; Marcet, Paula L; Sutcliffe, Alice C; Howell, Paul I

    2009-01-01

    Background When rearing morphologically indistinguishable laboratory strains concurrently, the threat of unintentional genetic contamination is constant. Avoidance of accidental mixing of strains is difficult due to the use of common equipment, technician error, or the possibility of self relocation by adult mosquitoes ("free fliers"). In many cases, laboratory strains are difficult to distinguish because of morphological and genetic similarity, especially when laboratory colonies are isolates of certain traits from the same parental strain, such as eye color mutants, individuals with certain chromosomal arrangements or high levels of insecticide resistance. Thus, proving genetic integrity could seem incredibly time-consuming or impossible. On the other hand, lacking proof of genetically isolated laboratory strains could question the validity of research results. Results We present a method for establishing authentication matrices to routinely distinguish and confirm that laboratory strains have not become physically or genetically mixed through contamination events in the laboratory. We show a specific example with application to Anopheles gambiae sensu stricto strains at the Malaria Research and Reference Reagent Resource Center. This authentication matrix is essentially a series of tests yielding a strain-specific combination of results. Conclusion These matrix-based methodologies are useful for several mosquito and insect populations but must be specifically tailored and altered for each laboratory based on the potential contaminants available at any given time. The desired resulting authentication plan would utilize the least amount of routine effort possible while ensuring the integrity of the strains. PMID:19849838

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 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. PMID:8890354

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. Damage detection under varying environmental and operational conditions using Wavelet Transform Modulus Maxima decay lines similarity

    NASA Astrophysics Data System (ADS)

    Tjirkallis, A.; Kyprianou, A.

    2016-01-01

    Over the last three decades, there have been increasing demands to develop and deploy Structural Health Monitoring (SHM) systems for engineering structures in service. Since these structures are subjected to varying environmental and operational conditions, reliable SHM methodologies must be capable of not misattributing to damage changes due to environmental conditions. This paper presents a novel damage detection methodology based on the similarity between maxima decay lines of the continuous wavelet transform scalogram of the structural responses obtained under different operational and environmental conditions. The normalized cross correlation (NCC) is used as a measure of this similarity. In addition, the pointwise summation of similar Wavelet Transform Modulus Maxima (WTMM) decay lines is used to identify changes due to the presence of damage from different force realizations and/or varying environmental conditions. The effectiveness of the proposed methodology is demonstrated using a simulated 3DOF system and an experimental cantilever beam.

  19. Influence of lubricant additives on rubber properties in conditions similar to the field

    SciTech Connect

    Dinzburg, B.N.

    1995-10-01

    Using FTIR spectroscopy, an investigation was performed to establish the oil degradation in a car engine under field conditions. This investigation was used as a baseline to create the laboratory rubber immersion in oil test with aeration. Aeration is required to improve the correlation of the laboratory immersion test with field conditions. The effects of dispersants, corrosion inhibitors and oxidation inhibitors containing amine groups on rubber compounds were evaluated in oil with and without aeration. Two rubber base compounds were tested: highly saturated butadiene-nitrile (HNBR) and fluoroelastomer (FKM). The aggressiveness of the inhibitors containing amines was varied and was affected to differing degrees by aeration, water, and type of rubber. 35 refs., 13 figs., 3 tabs.

  20. 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...

  1. 42 CFR 493.1441 - Condition: Laboratories performing high 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 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...

  2. 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...

  3. 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...

  4. 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...

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

    PubMed

    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

  6. 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

  7. 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.

  8. PULMONARY CELL POPULATIONS IN HAMSTERS MAINTAINED UNDER EGYPTIAN LABORATORY CONDITIONS

    EPA Science Inventory

    The study was conducted to obtain baseline values for pulmonary cells in golden hamsters (Mesocricetus auratus) bred and maintained under the laboratory conditions of Al-Azhar University in Egypt. An improvised technique is presented for measuring pulmonary cells obtained by lung...

  9. 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. PMID:26984749

  10. 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

    2008-10-01

    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. PMID:18691560

  11. Human Gait Recognition And Classification Using Similarity Index for various conditions

    NASA Astrophysics Data System (ADS)

    Makhdoomi, Nahid A.; Gunawan, Teddy S.; Habaebi, Mohamed H.

    2013-12-01

    Gait recognition is usually referred to signify the human identification by the style/way people walk in image sequences. Our aim is to implement the traditional gait recognition algorithm and to show the variation in gait recognition when subject is observed parallel to camera under three conditions- walking normal, carrying a bag and wearing a coat. However in this case, the work devises a novel method for the purpose of similarity computation rather than the traditional recognition where the overall recognition rate of 78.57 percent was obtained.

  12. Self-Similar evolution of Richtmyer-Meshkov instability under re-shock conditions

    NASA Astrophysics Data System (ADS)

    Malamud, Guy; Leinov, Eli; Formoza, Asi; Sadot, Oren; Levin, Arie; Ben-Dor, Gabi; Elbaz, Yonatan; Shvarts, Dov

    2011-10-01

    The Richtmyer-Meshkov (RM) instability is of critical importance in inertial confinement fusion (ICF) and astrophysics. In the present work a systematic study has been made of the growth of the turbulent mixing zone (TMZ) under re-shock conditions. In this study, shock-tube experiments were done by Leinov et al. changing the re-shock arrival time, by varying the shock-tube end wall distance, as well as the shock Mach number. Using 3D direct numerical simulations as well as 3D bubble-competition model, for various initial 3D conditions, it was found that the best agreement with the experimental results is achieved when the TMZ evolution is dominated by the self-similar behavior of the bubble size and amplitude distributions. The TMZ power law at the first and second shock was deducted from the experimental and numerical data and compared with the results of the bubble competition model.

  13. 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. 

  14. 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. PMID:26846472

  15. 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

    2015-01-01

    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. PMID:27250007

  16. Physiological responses of Corythucha ciliata adults to high temperatures under laboratory and field conditions.

    PubMed

    Ju, Rui-Ting; Gao, Lei; Zhou, Xu-Hui; Li, Bo

    2014-10-01

    Under high temperature conditions, insects can tolerate to survive through various physiological mechanisms, which have been well documented in laboratory studies. However, it is still unclear as to whether these laboratory data can scale up to those in the field. Here we studied dynamics of heat-induced metabolites in Corythucha ciliata adults under both laboratory and field conditions to examine their significance in thermal tolerance of the species. We compared the effects of controlled thermal treatments (2h at 33-43 °C at 2 °C intervals in the laboratory) and naturally increasing thermal conditions (10:00-14:00 at 2-h intervals (33.5-37.2 °C) on a hot summer day in a field in Shanghai, China) on water content and levels of water-soluble protein, triglycerides, mannitol, and sorbitol in the adult bodies. The results showed that water content significantly decreased and all other metabolic parameters significantly increased in response to temperature stresses with similar patterns in both the laboratory and field, although the respective threshold temperatures were different under the two conditions. The close linkage observed in the two conditions suggests that a short period of heat stress induces water loss and accumulation of thermal metabolites in C. ciliata adults. This heat-resistance provides a defense mechanism counteracting thermal damage in C. ciliata. PMID:25436946

  17. Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products

    NASA Astrophysics Data System (ADS)

    Schwartz, R. E.; Russell, L. M.; Sjostedt, S. J.; Vlasenko, A.; Slowik, J. G.; Abbatt, J. P. D.; MacDonald, A. M.; Li, S. M.; Liggio, J.; Toom-Sauntry, D.; Leaitch, W. R.

    2010-06-01

    Submicron particles collected at Whistler, British Columbia, at 1020 m a.s.l. during May and June 2008 on Teflon filters were analyzed by Fourier transform infrared (FTIR) and X-ray fluorescence (XRF) techniques for organic functional groups (OFG) and elemental composition. Organic mass (OM) concentrations ranged from less than 0.5 to 3.1 μg m-3, with a project mean and standard deviation of 1.3±1.0 μg m-3 and 0.21±0.16 μg m-3 for OM and sulfate, respectively. On average, organic hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and 23% of OM, respectively. Ketone, amine and organosulfate groups constituted 6%, 5%, and <1% of the average organic aerosol composition, respectively. Measurements of volatile organic compounds (VOC), including isoprene and monoterpenes from biogenic VOC (BVOC) emissions and their oxidation products (methyl-vinylketone / methacrolein, MVK/MACR), were made using co-located proton transfer reaction mass spectrometry (PTR-MS). We present chemically-specific evidence of OFG associated with BVOC emissions. Positive matrix factorization (PMF) analysis attributed 65% of the campaign OM to biogenic sources, based on the correlations of one factor to monoterpenes and MVK/MACR. The remaining fraction was attributed to anthropogenic sources based on a correlation to sulfate. The functional group composition of the biogenic factor (consisting of 32% alkane, 25% carboxylic acid, 21% organic hydroxyl, 16% ketone, and 6% amine groups) was similar to that of secondary organic aerosol (SOA) reported from the oxidation of BVOCs in laboratory chamber studies, providing evidence that the magnitude and chemical composition of biogenic SOA simulated in the laboratory is similar to that found in actual atmospheric conditions. The biogenic factor OM is also correlated to dust elements, indicating that dust may act as a non-acidic SOA sink. This role is supported by the organic functional group composition and morphology of single particles

  18. Biogenic oxidized organic functional groups in aerosol particles from a mountain forest site and their similarities to laboratory chamber products

    NASA Astrophysics Data System (ADS)

    Schwartz, R. E.; Russell, L. M.; Sjosted, S. J.; Vlasenko, A.; Slowik, J. G.; Abbatt, J. P. D.; MacDonald, A. M.; Li, S. M.; Liggio, J.; Toom-Sauntry, D.; Leaitch, W. R.

    2010-02-01

    Submicron particles collected at Whistler, British Columbia, at 1020 masl during May and June 2008 on Teflon filters were analyzed by Fourier transform infrared (FTIR) and X-ray fluorescence (XRF) techniques for organic functional groups (OFG) and elemental composition. Organic mass (OM) ranged from less than 0.5 to 3.1μg m-3, with a project mean and standard deviation of 1.3±1.0 μg m-3 and 0.21±0.16 μg m-3 for OM and sulfate, respectively. On average, organic hydroxyl, alkane, and carboxylic acid groups represented 34%, 33%, and 23% of OM, respectively. Ketone, amine and organosulfate groups constituted 6%, 5%, and <1% of the average organic aerosol composition, respectively. Measurements of volatile organic compounds (VOC), including isoprene and monoterpenes from biogenic VOC (BVOC) emissions and their oxidation products (methyl-vinylketone/methacrolein, MVK/MACR), were made using co-located proton transfer reaction mass spectrometry (PTR-MS). We present chemically-specific evidence of OFG associated with BVOC emissions. Positive matrix factorization (PMF) analysis attributed 65% of the campaign OM to biogenic sources, based on the correlations of one factor to monoterpenes and MVK/MACR. The remaining fraction was attributed to anthropogenic sources based on a correlation to sulfate. The functional group composition of the biogenic factor (consisting of 32% alkane, 25% carboxylic acid, 2% organic hydroxyl, 16% ketone, and 6% amine groups) was similar to that of secondary organic aerosol (SOA) reported from the oxidation of BVOCs in laboratory chamber studies, providing evidence that the magnitude and chemical composition of biogenic SOA simulated in the laboratory is similar to that found in actual atmospheric conditions. The biogenic factor OM is also correlated to dust elements, indicating that dust may act as a non-acidic SOA sink. This role is supported by the organic functional group composition and morphology of single particles, which were analyzed

  19. SIMILARITY BETWEEN MAN AND LABORATORY ANIMALS IN REGIONAL PULMONARY DEPOSITION OF OZONE

    EPA Science Inventory

    Predicted pulmonary ozone (O3) dose curves obtained by model analysis of the transport and removal of O3 in the lungs of guinea pigs, rabbits, and man indicate that a general similarity exists among these species in the shapes of the dose curves. An overview of the major features...

  20. 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. PMID:18164187

  1. 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.

  2. 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. PMID:23954274

  3. Waterflood oil recovery under mixed-wet conditions: laboratory observations

    NASA Astrophysics Data System (ADS)

    Tanino, Y.; Blunt, M. J.

    2013-12-01

    As an aqueous phase displaces a non-aqueous phase in a uniformly water-wet porous medium, a portion of the latter becomes immobilized by capillary forces as discontinuous pore-scale ganglia. This phenomenon, known as capillary trapping, has received renewed attention in recent years as a mechanism through which injected CO_2 may be secured against advection in a geological storage site. Here, we consider the impact of wettability on capillary trapping in oil/brine/rock systems. In uniformly water-wet rock, it is well established that residual oil saturation increases monotonically with its initial saturation. In contrast, salient features of mixed-wet rock, in which parts of the pore surface are oil-wet while the rest is water-wet, are not well established. We present laboratory measurements of remaining oil saturation in a limestone in its original, water-wet state and under mixed-wet conditions established systematically using organic acid. Under water-wet conditions, the remaining oil saturation increases linearly with its initial saturation. Under mixed-wet conditions, the remaining saturation displays three distinct regimes: as the initial oil saturation increases from 0, the remaining saturation increases, decreases, and finally increases again. These observations may have important implications for enhanced oil recovery, groundwater remediation, and injection schemes at carbon storage sites where contact with injected CO_2 alters the wettability of the grain surface.

  4. Carbon dynamics of two adjacent temperate forests under similar climatic conditions

    NASA Astrophysics Data System (ADS)

    Malla Thakuri, B.; Kim, J.

    2012-12-01

    The proximity (< 1.5 km) of the two KoFlux towers (i.e., Gwangneung coniferous forest site, GCK and deciduous forest site, GDK) provides an excellent opportunity to study carbon dynamics of the two different plant functional types under similar climate and environmental conditions. We have analyzed the CO2 flux data measured by eddy covariance from 2007 to 2010 at GCK and GDK sites. Our objectives were (1) to compare and contrast the seasonality and inter-annual variability in net ecosystem CO2 exchange (NEE) of the two adjacent forests and (2) to interpret their carbon dynamics in the framework of resilience concept. The multi-year measurements of CO2 fluxes at both sites showed contrasting inter-annual trends. Overall, both the annual gross primary productivity (GPP) and ecosystem respiration (RE) were higher for GCK site with an average NEE of -220 (±137) g C m-2 yr-1 while that of GDK was -67 (±58) g C m-2 yr-1. The GCK showed a continuous, threefold increase in NEE with lower water use efficiency whereas the GDK fluctuated between carbon source and weak to moderate carbon sink. Each year, both sites manifested a mid-season depression in GPP (and thus NEE), which was more pronounced at GCK. On a seasonal basis, summer was the most productive for GDK while spring for GCK. The results are interpreted in terms of phenology and different stages of adaptive cycles. Acknowledgment This work was funded by the Korea Meteorological Administration Research and Development Program under Grant CATER 2012-3030.

  5. Growth of immature Chironomus calligraphus in laboratory conditions.

    PubMed

    Canteiro, Rita de Cássia S A; Albertoni, Edélti F

    2011-12-01

    Chironomidae larvae are important macroinvertebrates in limnic environments, but little knowledge exists about their biometrics development characteristics. This study aims to describe the immature Chironomus calligraphus Goeldi, 1905 under laboratory conditions by the accomplishment of thirteen egg masses from eggs eclosion to adults emergency, at controlled room temperature (25ºC) and photoperiod (12-12h). Larvae were feed ad libitum with "Alcon Basic - MEP 200 Complex" fish food and commercial dehydrated Spirulina. The postures had a mean length of 9 ± 1 mm (n = 13) and 348 ± 66 eggs. The brownish colored eggs with elliptical shape had length of 160.3 ± 17.7 µm (n = 130), being arranged as an organized string in a pseudo spiral form. The time duration from the first to the four instars were three, four, four and eight days, and the average length of a cephalic capsule to each one of the instars (66.3 ± 12.3 µm, 102.9 ± 22.1 µm, 159 ± 24.6 µm, 249.2 ± 29.7 µm, n = 456) were significantly different (ANOVA, p < 0.001). The Dyar’s Rule showed a constant growth rate, r = 1.5. Our results demonstrated that C. calligraphus is a species with short life cycle, low mortality rate, food adaptability, fast larval growth and easily maintained at laboratory, factors that allowed the use of this native species as a tool for ecotoxicological tests. PMID:21971596

  6. Viability of Loma salmonae (Microsporidia) under laboratory conditions.

    PubMed

    Shaw, R W; Kent, M L; Adamson, M L

    2000-12-01

    The viability of the fish-infecting microsporidian Loma salmonae Morrison and Sprague, 1981 was determined under laboratory conditions by polar filament extrusion and infectivity to chinook salmon (Oncorhynchus tshawytscha). Extrusion rates of isolated spores decreased from 51.0% to 0.0% by 100 days after storage in fresh or sea water at 4 degrees C. Spores stored up to 95 days in either solution infected 80.0-100.0% of exposed chinook, although no spores infected fish at 100 days in one trial. Viability in Earl's balanced salt solution was tested up to 50 days, with 23.7% of spores extruding filaments and 80.0% of exposed chinook becoming infected. Spores frozen to -20 degrees C or -70 degrees C were unable to infect fish. PMID:11133113

  7. 42 CFR 493.1421 - Condition: Laboratories performing moderate complexity testing; testing personnel.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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....

  8. 42 CFR 493.1409 - Condition: Laboratories performing moderate complexity testing; technical consultant.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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....

  9. The Relationship of Belief Similarity to Attraction Following Conditioning and Generalization of Affect.

    ERIC Educational Resources Information Center

    Geen, Russell G.; Stonner, David

    Most studies of interpersonal attraction and rejection have come to the unremarkable conclusion that persons who are perceived as similar to one's self in beliefs and values are liked better than those perceived as dissimilar. This experiment was designed to vary in an orthogonal design (1) perceived similarity between a subject and another…

  10. 42 CFR 493.1487 - Condition: Laboratories performing high complexity testing; testing personnel.

    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... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1487 Condition: Laboratories performing high complexity testing; testing personnel. The laboratory has...

  11. 42 CFR 493.1459 - Condition: Laboratories performing high complexity testing; general supervisor.

    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... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1459 Condition: Laboratories performing high complexity testing; general supervisor. The laboratory must have...

  12. 42 CFR 493.1467 - Condition: Laboratories performing high complexity testing; cytology general supervisor.

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

  13. 42 CFR 493.1447 - Condition: Laboratories performing high complexity testing; technical supervisor.

    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... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1447 Condition: Laboratories performing high complexity testing; technical supervisor. The laboratory must have...

  14. 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

  15. 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

  16. Response to different environmental stress conditions of industrial and laboratory Saccharomyces cerevisiae strains.

    PubMed

    Garay-Arroyo, A; Covarrubias, A A; Clark, I; Niño, I; Gosset, G; Martinez, A

    2004-02-01

    Two sets of Saccharomyces cerevisiae strains were compared for their physiological responses to different stress conditions. One group is composed of three strains adapted to controlled laboratory conditions (CEN.PK, LR88 and RS58), whereas the other consisted of five industrial strains (IND1101, SuperStart, LO24, LO41 and Azteca). Most industrial strains showed higher tolerance to heat shock and to an oxidative environment than laboratory strains. Excluding CEN.PK, a similar behavior was observed regarding ethanol production in high sugar concentrations (180 g/l glucose). Addition of acetate (10 g/l) or furfural (2 g/l), in concentrations similar to those found in sugar cane bagasse hydrolysates, decreased cell mass formation and growth rate in almost all strains. CEN.PK and SuperStart showed the highest sensitivity when grown in furfural-containing medium. Acetic acid treatment severely affected cell mass formation and reduced growth rate in all strains; CEN.PK and LO24 were the most resistant. The specific ethanol production rate was not affected by furfural addition. However, specific ethanol production rates decreased in response to acetic acid in four industrial strains, and increased in all laboratory strains and in LO24. No significant correlation was found between the stress tolerance of the strains tested and the transcript accumulation of genes selected by their involvement in the response to each of the stressful environments applied. PMID:12910327

  17. Biologic Data of Cynomolgus Monkeys Maintained under Laboratory Conditions

    PubMed Central

    Rosso, Marilena Caterina; Badino, Paola; Ferrero, Giulio; Costa, Roberto; Cordero, Francesca; Steidler, Stephanie

    2016-01-01

    The cynomolgus monkey (Macaca fascicularis) is a well-known non-human primate species commonly used in non-clinical research. It is important to know basal clinical pathology parameters in order to have a reference for evaluating any potential treatment-induced effects, maintaining health status among animals and, if needed, evaluating correct substantiative therapies. In this study, data from 238 untreated cynomolgus monkeys (119 males and 119 females of juvenile age, 2.5 to 3.5 years) kept under laboratory conditions were used to build up a reference database of clinical pathology parameters. Twenty-two hematology markers, 24 clinical chemistry markers and two blood coagulation parameters were analyzed. Gender-related differences were evaluated using statistical analyses. To assess the possible effects of stress induced by housing or handling involved in treatment procedures, 78 animals (35 males and 35 females out of 238 juvenile monkeys and four adult males and four adult females) were used to evaluate cortisol, corticosterone and behavioral assessment over time. Data were analyzed using a non-parametric statistical test and machine learning approaches. Reference clinical pathology data obtained from untreated animals may be extremely useful for investigators employing cynomolgus monkeys as a test system for non-clinical safety studies. PMID:27280447

  18. 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

  19. 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. PMID:26076340

  20. Hydrological conditions at the 800 Area at Argonne National Laboratory

    SciTech Connect

    Patton, T.L.; Pearl, R.H.; Tsai, S.Y.

    1990-08-01

    This study examined the hydrological conditions of the glacial till underlying the 800 Area sanitary landfill at Argonne National Laboratory (ANL) near Lemont, Illinois. The study's purpose was to review and summarize hydrological data collected by ANL's Environment, Safety, and Health Department and to characterize, on the basis of these data, the groundwater movement and migration of potential contaminants in the area. Recommendations for further study have been made based on the findings of this review. The 800 Area landfill is located on the western edge of ANL, just south of Westgate Road. It has been in operation since 1966 and has been used for the disposal of sanitary, general refuse. From 1969 through 1978, however, substantial quantities of liquid organic and inorganic wastes were disposed of in a French drain'' at the northeast corner of the landfill. The 800 Area landfill is underlain by a silty clay glacial till. Dolomite bedrock underlies the till at an average depth of about 45.6 m. Trace levels of organic contaminants and radionuclides have been detected in groundwater samples from wells completed in the till. Fractures in the clay as well as sand and gravel lenses present in the till could permit these contaminants to migrate downward to the dolomite aquifer. When this report was prepared, no chemical quality analysis have been made on groundwater samples from the dolomite. The study found that existing information about subsurface characteristics at the site is inadequate to identify potential pathways for contaminant migration. Recommended actions include installation of five new well clusters and one background well, thorough record-keeping, sample collection and analysis during borehole drilling, slug testing to measure hydraulic conductivity, topographic mapping, continued monitoring of groundwater levels and quality, and monitoring of the unsaturated zone. 17 refs., 13 figs., 4 tabs.

  1. Flat trachea syndrome: a rare condition with symptoms similar to obstructive airway disease.

    PubMed

    Gani, Mohammed Akil D; Rogers, Vanessa J C; Sachak, Khalid H; Marzouk, Joseph F K

    2015-01-01

    Flat trachea syndrome, commonly known as 'tracheobronchomalacia', is a central airway disease characterised by excessive expiratory collapse of the tracheobronchial posterior membrane due to weakness in the airway walls. Patients present with symptoms such as chronic cough, dyspnoea and recurrent respiratory tract infections, which are often attributed to more common conditions such as asthma and chronic obstructive pulmonary disease (COPD). The term 'Flat Trachea Syndrome' was first proposed by Niranjan and Marzouk in 2010 following a retrospective study of 28 patients with the condition who underwent surgery for it. The authors advocated the term due to the primary abnormality being collapse of the posterior membranous wall of the central airways as opposed to softening of the tracheal cartilage (tracheobronchomalacia), which they proposed is a misnomer. We present a rare case of a patient with flat trachea syndrome on a history of COPD who initially presented with recurrent respiratory tract infections. PMID:25721828

  2. 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)…

  3. 42 CFR 493.1481 - Condition: Laboratories performing high complexity testing; cytotechnologist.

    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... REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing High Complexity Testing § 493.1481 Condition: Laboratories performing high complexity testing; cytotechnologist. For the subspecialty...

  4. 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 ...

  5. 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. PMID:25376832

  6. 42 CFR 493.1453 - Condition: Laboratories performing high complexity testing; clinical consultant.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Condition: Laboratories performing high complexity testing; clinical consultant. The laboratory must have a... testing; clinical consultant. 493.1453 Section 493.1453 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION...

  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. 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...

  9. 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

  10. Housing and husbandry conditions affect stereotypic behaviour in laboratory gerbils.

    PubMed

    Waiblinger, Eva; König, Barbara

    2007-01-01

    An artificial burrow was developed which fits into standard laboratory cages and significantly reduces stereotypic digging in gerbils. Also, the causes of bar-chewing were assessed experimentally. Neither the lack of gnawing material, nor the spatial proximity of cage-lid bars and food in the hopper nor the routine husbandry procedure of transferring juvenile gerbils to a fresh cage, but premature separation of juvenile gerbils from their parents before the birth of younger siblings significantly increased bar-chewing. PMID:19835062

  11. Life cycle of Ornithodoros mimon (Acari: Argasidae) under laboratory conditions.

    PubMed

    Landulfo, Gabriel Alves; Pevidor, Luisa Vianna; Dos Santos Sampaio, Janio; Luz, Hermes Ribeiro; Onofrio, Valeria Castilho; Faccini, João Luiz Horácio; Barros-Battesti, Darci Moraes

    2012-09-01

    Ornithodoros mimon Kohls et al. is an argasid tick, originally described from larvae collected on bats from Bolivia and Uruguay. In Brazil the species is aggressive to humans and animals. Nymphs and adults of O. mimon were collected from the roof of a residence in Araraquara, São Paulo, Brazil, whose residents were bitten by ticks. Once in the laboratory, they were fed on rabbits and maintained in biological oxygen demand incubator at 27 ± 1 °C and 90 ± 10 % relative humidity. The females, after mating, laid eggs that resulted in larvae that were identified by the original description and also by the paratypes examination (RML 50271-50274) deposited at the United State National Tick Collection, Georgia, GA, USA. The life cycle of this species was obtained through the acquisition of two generations of ticks (F1 and F2) in the laboratory using rodents and rabbits as hosts. The biological parameters of larva, nymph and adult stages of both generations were recorded from infestations of the laboratory hosts. Larvae showed a profile of feeding for days on the host, whereas the nymphs and adults fed only for few minutes. First nymphal instar (N1) molted to second nymphal instar (N2) without blood meal. The species life cycle was elucidated for the first time. PMID:22570058

  12. Similar spatial patterns of neural coding of category selectivity in FFA and VWFA under different attention conditions.

    PubMed

    Xu, Guifang; Jiang, Yi; Ma, Lifei; Yang, Zhi; Weng, Xuchu

    2012-04-01

    It has long been debated whether attention alters the categorical selectivity in regions such as the fusiform face area (FFA) and the visual word form area (VWFA). We addressed this issue by examining whether the spatial pattern of neural representations for certain stimulus categories in these regions would change under different attention conditions. Faces, Chinese characters, and textures were presented in a block design fMRI experiment where participants in different runs attended to the stimuli under different conditions of attention. After localizing regions of interest (ROIs) in FFA and VWFA using general linear models, we performed spatial pattern analyses to examine both within- and cross-condition classification in these ROIs. The within-condition results replicated previous findings showing significant classification accuracy reduction when there was less attention compared with more attention. Critically, cross-condition classification in both FFA and VWFA revealed significantly above-chance accuracy for all stimulus categories, suggesting similar spatial neural representations across different attention conditions. Further strengthening this conclusion, when the contrast-to-noise ratio (CNR) of the signals was adjusted to increase signal strength, cross-condition classification accuracy for faces in FFA and for Chinese characters in VWFA improved significantly, even approaching within-condition accuracy. This indicates that attention does not modulate the spatial pattern of neural representations involved in category selectivity, but only changes the signal strength relative to the noise level. PMID:22306521

  13. Life Cycle of Amblyomma romitii (Acari: Ixodidae) Under Laboratory Conditions.

    PubMed

    Landulfo, G A; Luz, H R; Sampaio, J S; Faccini, J L H; Barros-Battesti, D M

    2016-01-01

    The life cycle of Amblyomma romitii Tonelli-Rondelli, 1939 is reported for the first time, using rabbits (Oryctolagus cuniculus) for larvae and capybara (Hydrochoerus hydrochaeris) for nymphs and adults, as experimental hosts. Developmental periods of free-living stages were observed in an incubator at 27 ± 1°C, 80 ± 10% relative humidity (RH), and 24-h darkness. The life cycle of A. romitii in the laboratory could be completed in an average period of 216.4 d. The overall sex ratio (M:F) was 1:1.4. The results showed that rabbits are quite suitable as experimental hosts for the larval stages of A. romitii, while capybaras are suitable experimental hosts for nymphs and adults. PMID:26487244

  14. Laboratory conditions and safety in a chemical warfare agent analysis and research laboratory.

    PubMed

    Kenar, Levent; Karayilanoğlu, Turan; Kose, Songul

    2002-08-01

    Toxic chemicals have been used as weapons of war and also as means of terrorist attacks on civilian populations. Research focusing on chemical warfare agents (CWAs) may be associated with an increased risk of exposure to and contamination by these agents. This article summarizes some of the regulations concerning designation and safety in a CWA analysis and research laboratory and medical countermeasures in case of an accidental exposure. The design of such a laboratory, coupled with a set of safety guidelines, provides for the safe conduct of research and studies involving CWAs. Thus, a discussion of decontamination and protection means against CWAs is also presented. PMID:12188231

  15. 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.

  16. SIMILARITY IN RESPONSES OF LABORATORY-REARED ANED FIELD-COLLECTED LONE STAR TICK (ACARI:IXODIDAE)NYMPHS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field testing tick repellents intended for use on human skin can be difficult, particularly when multiple concentrations of multiple repellents must be tested. Therefore, laboratory tests using laboratory reared ticks have been important. To address concerns that test results obtained with laborator...

  17. Basic Demography of Caenorhabditis remanei Cultured under Standard Laboratory Conditions

    PubMed Central

    Lindström, Jan; Haydon, Daniel T.

    2008-01-01

    Species of the Caenorhabditis genus have been used as model systems in genetics and molecular research for more than 30 years. Despite this, basic information about their demography, in the wild and in the lab, has remained unknown until very recently. Here, we provide for the first time a closely quantified life-cycle of the gonochoristic nematode C. remanei. Using C. elegans protocols, modified for an outcrossing nematode, we estimated the basic demography for individuals of two strains (JU724 and MY12-G) which were recently isolated from the wild. We used a half-sib breeding design to estimate the phenotypic variance of traits of related (within line) and unrelated individuals (between lines) of the two strains cultured in a common environment in the lab. Comparisons between these strains showed that JU724 was characterized by significantly lower overall lifetime fecundity and by differences in age-specific fecundity relative to MY12-G, but there were no differences in their life expectancy and reproductive lifespan. We found high phenotypic variance among all traits. The variance within lines was relatively high compared to the low variation between lines. We suggest this could be the result of high gene flow in these wild-type strains. Finally, comparisons between species suggest that, despite the differences in reproductive strategies (i.e., sex ratios, lifetime fecundity), C. remanei has developmental time similar to the hermaphroditic N2 strain of C. elegans. PMID:19440256

  18. Similarities Between Cometary, Meteoritic, and Laboratory Analog Dust: Hints from the Attribution of the 10-micrometer Band

    NASA Astrophysics Data System (ADS)

    Colangeli, L.; Mennella, V.; Bussoletti, E.; Merluzzi, P.; Rotundi, A.; Palumbo, P.; di Marino, C.

    1993-07-01

    analysis have allowed us to evidence the following main results. Matrix effects do not appear as relevant as suggested by computations performed by the Mie theory. In particular, the peak shift observed for crystalline olivine is from 11.3 micrometers in CsI (n(sub)o = 1.7) to 11.2 micrometers in vacuum (n(sun)o = 1.0). On the other hand, jadeite and andesite grains present main peaks around 10 micrometers, in contrast to cometary spectra. We can, therefore, conclude that crystalline olivine grains are good candidates to simulate the cometary 11.3 micrometer sharp feature, even when matrix effects are accounted for. The impactite sample presents a main broad band around 9.2 micrometers, due to its mainly amorphous composition. This band could resemble the broad 10 micron cometary band; however, its profile is rather broader than that observed for cometary dust. Concerning the meteoritic samples, both chondrite and pallasite show a well defined main peak at 11.3-11.4 micrometers, comparable to cometary spectra. Again, chondrite band profile is too broad. On the contrary, pallasite appears to be a good candidate to reproduce observations. This result appears reasonable if one considers that the sample is formed by small olivine crystals embedded in a iron matrix. In conclusion, the comparison between the spectra of olivine-rich meteoritic grains and cometary dust could suggest either a common origin of the two classes of materials or, at least, a similarity in the processes experienced by them during past evolution. This result appears very relevant because it could imply that the systematic study in the laboratory of meteoritic materials can provide information about the past history of comets. Acknowledgements: This work was partly supported by ASI, CNR, and MURST 40% and 60%. References: [1] Bregman J. D. et al. (1987) Astron. Astrophys., 187, 616. [2] Campins H. and Ryan E. V. (1989) Ap. J., 341, 1059. [3] Hanner M. S. et al. (1990) Ap. J., 348, 312. [4] Lynch D. K. et

  19. 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

  20. 42 CFR 493.1467 - Condition: Laboratories performing high complexity testing; cytology general supervisor.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... testing; cytology general supervisor. 493.1467 Section 493.1467 Public Health CENTERS FOR MEDICARE....1467 Condition: Laboratories performing high complexity testing; cytology general supervisor. For the subspecialty of cytology, the laboratory must have a general supervisor who meets the...

  1. 42 CFR 493.1467 - Condition: Laboratories performing high complexity testing; cytology general supervisor.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... testing; cytology general supervisor. 493.1467 Section 493.1467 Public Health CENTERS FOR MEDICARE....1467 Condition: Laboratories performing high complexity testing; cytology general supervisor. For the subspecialty of cytology, the laboratory must have a general supervisor who meets the...

  2. 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....1467 Condition: Laboratories performing high complexity testing; cytology general supervisor. For the subspecialty of cytology, the laboratory must have a general supervisor who meets the...

  3. 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....1467 Condition: Laboratories performing high complexity testing; cytology general supervisor. For the subspecialty of cytology, the laboratory must have a general supervisor who meets the...

  4. 42 CFR 493.1453 - Condition: Laboratories performing high complexity testing; clinical consultant.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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...

  5. 42 CFR 493.1415 - Condition: Laboratories performing moderate complexity testing; clinical consultant.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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...

  6. FGFR3-related condition: a skeletal dysplasia with similarities to thanatophoric dysplasia and SADDAN due to Lys650Met.

    PubMed

    Farmakis, Shannon G; Shinawi, Marwan; Miller-Thomas, Michelle; Radmanesh, Alireza; Herman, Thomas E

    2015-03-01

    Mutations in the fibroblast growth factor receptor 3 (FGFR3) gene account for six related skeletal dysplasia conditions: achondroplasia, hypochondroplasia, thanatophoric dysplasia types 1 and 2, SADDAN (severe achondroplasia with developmental delay and acanthosis nigricans), and platyspondylic lethal skeletal dysplasia, San Diego type. This group of disorders has very characteristic clinical and radiologic features, which distinguish them from other skeletal dysplasias. They display a spectrum of severity in the skeletal findings, ranging from relatively mild hypochondroplasia to lethal thanatophoric dysplasia. We report a patient who has the missense FGFR3 mutation, Lys650Met, previously reported in association only with SADDAN, who exhibits some findings similar to both thanatophoric dysplasia (types 1 and 2) in addition to those findings characteristic of SADDAN. PMID:25119967

  7. Inflammatory myopathy with abundant macrophages (IMAM): a condition sharing similarities with cytophagic histiocytic panniculitis and distinct from macrophagic myofasciitis.

    PubMed

    Bassez, Guillaume; Authier, Francois-Jérôme; Lechapt-Zalcman, Emmanuèle; Delfau-Larue, Marie Hélène; Plonquet, Anne; Coquet, Michelle; Illa, Isabel; Gherardi, Romain K

    2003-05-01

    We describe the unreported pattern of inflammatory myopathy with abundant macrophages (IMAM) as a main differential diagnosis of postimmunization aluminum hydroxide-induced macrophagic myofasciitis (MMF). IMAM was mainly detected among patients with a dermatomyositis (DM)-like disease. Among 113 muscle biopsies from DM patients collected from 1974 to 2000, intensity of macrophage infiltration was highly variable: 41.5% (-/+); 34.5% (+); 17% (++): and 7% (+++). The 27 patients from groups (++) and (+++) had a similar pattern of macrophagic infiltration and were considered to have IMAM. They were compared to 40 MMF patients. In IMAM, macrophage infiltrates were diffuse and correlated positively with both T cell infiltrates and acute muscle fiber damage, and showed pictures of hemophagocytosis (21/27). Connective tissue structures were infiltrated by noncohesive, ribbon-forming collections of large basophilic macrophages containing no crystalline inclusions. In MMF, macrophage infiltrates were focal and formed compact well-delineated aggregates of granular PAS+ cells, loaded with crystalline aluminum hydroxide particles, in the absence of either hemophagocytosis or conspicuous muscle damage. Review of the literature indicates similarities between IMAM and "cytophagic histiocytic panniculitis" (CHP), a condition characterized by T cell-triggered macrophage hyperactivation. Both IMAM and CHP, but not MMF, may be associated with a life-threatening hemophagocytic syndrome. PMID:12769186

  8. Survival of Theileria parva in its nymphal tick vector, Rhipicephalus appendiculatus, under laboratory and quasi natural conditions.

    PubMed

    Ochanda, H; Young, A S; Medley, G F

    2003-06-01

    Groups of nymphal Rhipicephalus appendiculatus Muguga, having a mean of 1 or 9 Theileria parva Muguga-infected salivary gland acini per tick, were kept under quasi-natural conditions at an altitude of 1950 m or 20 degrees C at a relative humidity of 85% in the laboratory and their survival and infection prevalence and abundance determined over time. Theileria parva infections for both categories of ticks survived in the nymphal ticks for 50 or 26 weeks post salivary gland infection under quasi-natural or laboratory conditions respectively. There was a distinct decline in infections in the more heavily infected nymphae under both conditions of exposure, reflecting an apparent density dependence in parasite survival. Nymphal ticks having an average infection level of 1 infected salivary gland acinus per tick, survived for up to 69 or 65 weeks post-repletion under quasi-natural or the laboratory conditions respectively. Nymphae having an average infection level of 9 infected salivary gland acini per tick survived for a similar duration under each of the 2 conditions. The infection level of 9 infected salivary gland acini per tick did not seem to significantly affect the survival of the tick vector compared to those having an average of 1 infected salivary gland acinus per tick. PMID:12866795

  9. 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.

  10. Rapid Degradation of Alkanethiol-Based Self-Assembled Monolayers on Gold in Ambient Laboratory Conditions

    SciTech Connect

    Willey, T M; Vance, A L; van Buuren, T; Bostedt, C; Terminello, L J; Fadley, C S

    2004-07-21

    Self-assembled monolayers (SAMs) consisting of alkanethiols and similar sulfur-containing molecules on noble metal substrates are extensively used and explored for various chemical and biological surface-functionalization in the scientific community. SAMs consisting of thiol- or disulfide-containing molecules adsorbed on gold are commonly used due to their ease of preparation and stability. However, the gold-thiolate bond is easily and rapidly oxidized under ambient conditions, adversely affecting SAM quality and structure. Here, the oxidation of dodecanethiol on gold is explored for various 12-hour exposures to ambient laboratory air and light. SAM samples are freshly prepared, air-exposed, and stored in small, capped vials. X-ray photoelectron spectroscopy (XPS) reveals nearly complete oxidation of the thiolate in air-exposed samples, and a decrease in carbon signal on the surface. Near-edge X-ray absorption fine structure spectroscopy (NEXAFS) at the Carbon K-edge shows a loss of upright orientational order upon air-exposure. Alternatively, the oxidation of the thiolate is minor when SAMs are stored in limited-air-containing small 15 ml vials. Thus, care must be taken to avoid SAM degradation by ensuring alkanethiolates on gold have sufficient durability for each intended environment and application.

  11. 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)

  12. 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

  13. 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

  14. Self-formed Dynamic Meandering Rivers and Floodplains in the Laboratory: Necessary and Sufficient Conditions

    NASA Astrophysics Data System (ADS)

    Kleinhans, M. G.; van Dijk, W. M.; van de Lageweg, W. I.; Markies, H.; van der Gon-Netscher, T.; van de Meer, H.; van Maarseveen, M.; Postma, G.

    2010-12-01

    Traditionally, rivers were downscaled to the laboratory through similarity of the Froude, Shields and Reynolds numbers. This has worked well for rivers with fixed banks and for braided gravel-bed rivers. However, for self-formed dynamic meandering rivers in experiments, Froude scaling is incomplete without a constrained width-depth ratio. This aspect ratio should be small enough to obtain alternate bars. Bank erosion and bar migration have to be limited by somewhat cohesive or vegetated self-formed floodplains. Our objective is to determine the conditions that lead to river meandering in the laboratory. We developed an experimental scaling strategy for meandering gravel-bed rivers that reduces scale problems or quantifies scale effects. A sediment mixture ranging from silt to fine gravel produces subcritical to critical flow, a hydraulically rough boundary without scour holes or current ripples. Furthermore the mixture leads to richer morphodynamics with measurable sorting trends, narrower channels and cohesive self-formed floodplains. We cycle the inflow point of constant flow discharge and sediment feed in transverse direction at the upstream boundary to perturb an initially straight channel and simulate a meander migrating into the flume (Van Dijk et al., this conference). The downstream boundary is a lake into which the river progrades a branched fan delta (Villiers et al., Cheshier et al., van de Lageweg et al., this conference). Morphology was recorded by high-resolution line-laser scanning and digital photography allowed image segmentation and particle size estimation through an entropy method. In agreement with earlier work, the experimental river initially evolves from alternate bars to a fully braided river without significant floodplain building. With silica flour added to the feed, a transitional river between braided and meandering evolves with frequent chute cut-offs but mostly single-thread. During chute cut-offs the water and bed levels upstream of

  15. Comparing the Slaking of Clay-Bearing Rocks Under Laboratory Conditions to Slaking Under Natural Climatic Conditions

    NASA Astrophysics Data System (ADS)

    Gautam, T. P.; Shakoor, A.

    2016-01-01

    The objective of this study was to compare the laboratory slaking behavior of common clay-bearing rocks to their slaking behavior under natural climatic conditions observed during a 1-year experimental study. Five-cycle slake durability tests were performed in the laboratory on five claystones, five mudstones, five siltstones, and five shales. Twelve replicate specimens of each of these 20 rocks were also exposed to natural climatic conditions for 12 months. After each month of exposure, one replicate specimen of each rock was removed from natural exposure and its grain size distribution was determined. The results of laboratory tests and field experiment were compared in terms of 1st, 2nd, 3rd, 4th, and 5th cycle slake durability indices (Id1, Id2, Id3, Id4, Id5), grain size distribution of slaked material, and disintegration ratio ( D R), where D R is the ratio of the area under the grain size distribution curve of slaked material for a given specimen to the total area encompassing all grain size distribution curves of the specimens tested. Correlations of Id1, Id2, Id3, Id4, and Id5 with D R values for laboratory specimens exhibit R 2 values of 0.87, 0.88, 0.83, 0.75, and 0.70, respectively. However, the relationship between Id2 and D R, determined after 1, 3, 6, and 12 months of natural exposure, becomes weaker with increasing time of exposure, with R 2 values of 0.65, 0.63, 0.63, and 0.25, respectively. The fifth-cycle slake durability index (Id5) for laboratory tested specimens shows a better correlation with D R values for naturally exposed specimens ( R 2 up to 0.80). A comparison of grain size distribution curves of slaked material for laboratory specimens, after the 2nd cycle slake durability test, with those of specimens exposed to natural climatic conditions shows that the laboratory test underestimates the field durability for claystones, and overestimates it for siltstones.

  16. Vital Statistics of Triatominae (Hemiptera: Reduviidae) Under Laboratory Conditions: IV. Panstrongylus geniculatus.

    PubMed

    Rabinovich, Jorge Eduardo; Feliciangeli, M Dora

    2015-09-01

    A cohort of 100 eggs of Panstrongylus geniculatus (Latreille) was reared in the laboratory under constant conditions (temperature 26 ± 1°C, 60 ± 10% RH), with mortality and fecundity data recorded weekly. We calculated stage-specific development times, age-specific mortality and fecundity (18.4 eggs/♀/wk), and stage-specific and total preadult mortality (31.6%), and the weekly intrinsic rate of natural increase (r(o) = 0.096), the finite population growth rate (λ = 1.109), the net reproductive rate (R(0) = 60.45), and the generation time (T = 46.34 wk). Elasticity analysis showed that the dominant life-history trait determining λ was survival (particularly the adult female's survival). Adult females dominated the stage-specific reproductive value, and the egg stage dominated the stable stage distribution (SSD). The damping ratio (ρ = 1.096) suggests a relatively rapid period of recovery to a disturbed SSD. Results were compared with one previous study and conform relatively well, considering that environmental conditions were not the same. We estimated the colonizing ability of P. geniculatus, using as a criterion the ro/b index, and obtained the value of 0.74, an indicator of a good colonizer, and similar to well-known invasive species such as Rhodnius prolixus and Triatoma infestans. The life history traits and demographic parameters here presented for P. geniculatus are discussed in terms of their usefulness for evolutionary studies and vector control activities. PMID:26336251

  17. 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.

  18. A comparative study of nitrate leaching from soils of differing textures under similar climatic and cropping conditions

    NASA Astrophysics Data System (ADS)

    Vinten, A. J. A.; Vivian, B. J.; Wright, F.; Howard, R. S.

    1994-07-01

    This study reports a direct comparison of nitrate leaching on a field scale from a sandy soil overlying a relatively impermeable glacial till ( Ksat = 30-50 mm day -1), with that from a clay loam soil overlying a similar glacial till ( Ksat = 2-8 mm day -1), under nearly identical climatic and cropping conditions. Drained plots were installed at each site, and N application rate on the plots, which grew spring barley, varied from 0 to 210 kg N ha -1. Nitrate concentrations in drainage water from the two sites were measured using a simple flow-weighted sampling device and drainflow was measured using tipping bucket flow meters. Total leaching losses (including an estimate of deep percolation) in the first year of the comparison were not significantly higher on the sandy site (38 ± 11 kg N ha -1 at 150 kg N ha -1 N fertiliser application) than on the clay loam site (27 ± 4 kg N ha -1). In the subsequent 2 years, leaching losses increased at the sandy loam site. At the clay loam site leaching losses were much lower (7-11 kg N ha -1) in the final year). Timing of cultivation was an important factor influencing the amount of leaching in the clay loam soil. The effect of applied N fertiliser on nitrate leaching was small at both sites, except in the final year at the sandy site, which leached 105 kg N ha -1 at the highest fertiliser rate. The interpretation of these results was aided by concurrent chloride leaching experiments. These experiments showed that the residence time of a substantial proportion of chloride (40-50%) was longer than 1 year. This may be because of diffusion and slow convection into the glacial till horizons, where the residence time is long.

  19. Metal effects on fathead minnows (Pimephales promelas) under field and laboratory conditions.

    PubMed

    Gauthier, Charles; Couture, Patrice; Pyle, Greg G

    2006-03-01

    The consequences of low-level metal exposure to early life stages of fathead minnows (Pimephales promelas) were investigated along a contamination gradient near Sudbury, Canada. Field exposures resulted in elevated hatching time and increased mortality in metal-contaminated lakes, in contrast to laboratory exposures where no effects were observed. Dissolved and ionic Cd and Ni were associated with changes in hatching time and larval mortality under field conditions, though other potential contaminants were not examined and may also have had an influence. The increased biological response of field-exposed fish, relative to fish exposed to the same water in laboratory conditions, may be the result of higher stress in natural environments, which could sensitize fish to contaminants. Analysis also indicated that, as contamination increases, the discrepancies between laboratory and field estimates of effect also increase. A temperature versus hatching time relationship was also quantified for fathead minnows. PMID:16507372

  20. The Effect of SpeechEasy on Stuttering Frequency in Laboratory Conditions

    ERIC Educational Resources Information Center

    Armson, Joy; Kiefte, Michael; Mason, Jessica; De Croos, Dayani

    2006-01-01

    The effect of SpeechEasy on stuttering frequency during speech produced in a laboratory setting was examined. Thirteen adults who stutter participated. Stuttering frequencies in two baseline conditions were compared to stuttering frequencies with the device fitted according to the manufacturer's protocol. The fitting protocol includes instructions…

  1. Mating frequency of the male cactus moth Cactoblastis cactorum (Lepidoptera:Pyralidae), under laboratory conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the number of times that males of the invasive cactus moth Cactoblastis cactorum (Berg) mate under laboratory conditions. Virgin females were provided to each male at 24 h intervals until male death. Females removed from the containers were dissected to ascertain their mating ...

  2. 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.

  3. 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. PMID:25717006

  4. Reproduction, development and habits of the large turkey louse Chelopistes meleagridis (Phthiraptera: Ischnocera) under laboratory conditions.

    PubMed

    Maturano, R; Daemon, E

    2014-08-01

    The bionomy of Chelopistes meleagridis off the host was observed with the aim of better understanding the aspects of this species' life cycle. For this purpose, C. meleagridis adults were collected and maintained under controlled conditions to reproduce (35°C and RH > 80%), with turkey feathers as the food source. From the offspring of these lice, the development of 150 individuals was observed from the egg to the adult phase. These eggs were divided into two groups of 75 each. After hatching, one group was given a diet composed of feathers while the other received feathers plus skin of the host turkey (Meleagris gallopavo). The "feather + skin" diet resulted in the greatest number of adults, so this diet was given to the next generation of lice reared in vitro, starting from the first instar, to observe their fertility, fecundity and longevity. High reproduction rates were found in relation to other lice of the Ischnocera sub-order, particularly the number of eggs per day and number of eggs produced per female over the lifetime (means of 2.54 and 26.61 eggs, respectively, for wild females and 2.11 and 29.33 eggs for laboratory-reared females). The inclusion of skin in the diet was a determining factor for development to the adult stage, since 48% of the lice fed this diet reached that stage, versus 1.3% that reached maturity fed only with feathers. The development time of the males and females was similar (mean of 29.38 days), without any difference in the sexual proportion of the adults. PMID:25296223

  5. 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.

  6. 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). PMID:25166328

  7. 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…

  8. 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…

  9. Sufficient condition for finite-time singularity and tendency towards self-similarity in a high-symmetry flow

    NASA Astrophysics Data System (ADS)

    Ng, C. S.; Bhattacharjee, A.

    A highly symmetric Euler flow, first proposed by Kida (1985), and recently simulated by Boratav and Pelz (1994) is considered. It is found that the fourth order spatial derivative of the pressure (pxxxx) at the origin is most probably positive. It is demonstrated that if pxxxx grows fast enough, there must be a finite-time singularity (FTS). For a random energy spectrum E(k) ∞ k-v, a FTS can occur if the spectral index v<3. Furthermore, a positive pxxxx has the dynamical consequence of reducing the third derivative of the velocity uxxx at the origin. Since the expectation value of uxxx is zero for a random distribution of energy, an ever decreasing uxxx means that the Kida flow has an intrinsic tendency to deviate from a random state. By assuming that uxxx reaches the minimum value for a given spectral profile, the velocity and pressure are found to have locally self-similar forms similar in shape to what are found in numerical simulations. Such a quasi self-similar solution relaxes the requirement for FTS to v<6. A special self-similar solution that satisfies Kelvin's circulation theorem and exhibits a FTS is found for v=2.

  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

    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 absorping 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 leads to significant misinterpretation of available opacity data. Laboratory measurement of the microwave properties of atmospheric gases under simulated conditions for the outer planets were conducted. Results of these measurements are discussed.

  11. Repeatability of metabolic rate is lower for animals living under field versus laboratory conditions.

    PubMed

    Auer, Sonya K; Bassar, Ronald D; Salin, Karine; Metcalfe, Neil B

    2016-03-01

    Metabolic rate has been linked to several components of fitness and is both heritable and repeatable to a certain extent. However, its repeatability can differ among studies, even after controlling for the time interval between measurements. Some of this variation in repeatability might be due to the relative stability of the environmental conditions in which the animals are living between measurements. We compared published repeatability estimates for basal, resting and maximum metabolic rate from studies of endotherms living in the laboratory with those living in the wild during the interval between measurements. We found that repeatability declines over time, as demonstrated previously, but show for the first time that estimates from free-living animals are also considerably lower than those from animals living under more stable laboratory conditions. PMID:26747898

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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. PMID:18791736

  17. Rearing Africanized honey bee (Apis mellifera L.) brood under laboratory conditions.

    PubMed

    Silva, I C; Message, D; Cruz, C D; Campos, L A O; Sousa-Majer, M J

    2009-01-01

    We developed a method for rearing larvae of Africanized bees under laboratory conditions to determine the amount of diet needed during larval development to obtain a worker bee. We started with larvae 18-24 h old, which were transferred to polyethylene cell cups and fed for five days. We found that the amount of diet needed for successful larval development was: 4, 15, 25, 50, and 70 microl during the first to fifth days, respectively. The survival rate to the adult stage was 88.6% when the larvae received the daily amount of diet divided into two feedings, and 80% when they received only one feeding per day. The adult weight obtained in the laboratory, when the larvae received the daily amount of diet in a single dose, did not differ from those that were developed under field conditions (our control). All adults that we obtained in laboratory appeared to be normal. This technique has the potential to facilitate studies on brood pathogens, resistance mechanisms to diseases and also might be useful to test the impacts of transgenic products on honey bee brood. PMID:19551650

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. Comparison of Life Tables of Cheilomenes sexmaculata (Coleoptera: Coccinellidae) Under Laboratory and Greenhouse Conditions.

    PubMed

    Zhao, Jing; Li, Shu; Gao, Xi-Wu; Zhang, Fan; Wang, Su

    2015-08-01

    The ladybird Cheilomenes sexmaculata (F.) is an important aphidophagous predator in Asia. In order to mass rear predators for biological control, it is valuable to identify the features of populations that are affected by variations in field conditions. Life tables can provide comprehensive descriptions of the development, survival, and fecundity of a population. However, there are few life table studies of C. sexmaculata. Studies of life history have been carried out in many arthropods using the traditional female age-specific life table, which takes only female individuals into consideration, while the variations in developmental rates amongst individuals are ignored. In this paper, we constructed life tables for C. sexmaculata fed on Myzus persicae (Sulzer) both at constant temperature in the laboratory and fluctuating temperature in the greenhouse, and analyzed the data using the age-stage, two-sex life table. The bootstrap technique was used to estimate the standard errors of the population parameters. The results showed that preadult C. sexmaculata developed more slowly and had lower survival and reproductive rates under greenhouse conditions, as indicated by the curves of age-stage survival rate (s(xj)), age-stage-specific fecundity (f(x j)) of the female stage, age-specific fecundity (m(x)), and age-specific maternity (l(x)m(x)). Our results also showed that the intrinsic rate of increase (r), net reproductive rate (R(0)), and finite rate of increase (λ) under laboratory and greenhouse conditions were 0.1668 d(-1) and 0.1027 d(-1), 192.1 and 53.0, and 1.1815 d(-1) and 1.1082 d(-1), respectively. Our results revealed significantly different life table parameters for C. sexmaculata under laboratory and greenhouse conditions. This information will be useful for developing a successful mass-rearing program for C. sexmaculata for use in biological control. PMID:26470311

  3. Emergence of cercariae of Echinostoma caproni and Schistosoma mansoni from Biomphalaria glabrata under different laboratory conditions.

    PubMed

    Fried, B; LaTerra, R; Kim, Y

    2002-12-01

    Release of Echinostoma caproni cercariae and Schistosoma mansoni from experimentally infected Biomphalaria glabrata snails maintained under different laboratory conditions was studied. Infected snails were isolated individually for 1 h in Stender dishes containing 5 ml of artificial spring water and the number of cercariae released during this time was recorded. Of numerous conditions tested, the addition of lettuce, the use of water conditioned by B. glabrata snails and a temperature of 35 degrees C significantly increased the release of E. caproni cercariae. A significant increase in cercarial release of S. mansoni was seen only in cultures fed lettuce. A temperature of 12 degrees C caused a significant decrease in cercarial release of both E. caproni and S. mansoni. Increased snail activity associated with feeding behaviour was probably responsible for the enhanced cercarial sheds observed in this study. PMID:12498644

  4. 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

    The recognition of the need to make laboratory measurements of simulated planetary atmospheres over a range of temperatures and pressure which correspond to the altitudes probed by 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. Construction was completed of the outer planets simulator and measurements were conducted of the microwave absorption and refraction from nitrogen under simulated Titan conditions. The results of these and previous laboratory measurements were applied to a wide range of microwave opacity measurements, in order to derive constituent densities and distributions in planetary atmospheres such as Venus.

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

    PubMed

    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

  6. 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

  7. The impact of soil preparation on the soil erosion rates under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Khaledi Darvishan, A.; Homayounfar, V.; Sadeghi, S. H. R.

    2015-03-01

    The use of laboratory methods in soil erosion studies causes soil disturbance, preparation and placement in experimental plots and has been recently considered more and more because of many advantages. 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 less attention 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 m × 1 m-plots were adopted in an 18% gradient slope with sandy-clay-loam soil in the Kojour watershed, Northern Iran. 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 three-minute intervals after time-to-runoff were then measured. The results showed the significant (p ≤ 0.01) increasing effects of soil preparation 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.

  8. Self-similar bumps and wiggles: Isolating the evolution of the BAO peak with power-law initial conditions

    NASA Astrophysics Data System (ADS)

    Orban, Chris; Weinberg, David H.

    2011-09-01

    Motivated by cosmological surveys that demand accurate theoretical modeling of the baryon acoustic oscillation (BAO) feature in galaxy clustering, we analyze N-body simulations in which a BAO-like Gaussian bump modulates the linear theory correlation function ξL(r)=(r0/r)n+3 of an underlying self-similar model with initial power spectrum P(k)=Akn. These simulations test physical and analytic descriptions of BAO evolution far beyond the range of most studies, since we consider a range of underlying power spectra (n=-0.5, -1, -1.5) and evolve simulations to large effective correlation amplitudes (equivalent to σ8=4-12 for rbao=100h-1Mpc). In all cases, nonlinear evolution flattens and broadens the BAO bump in ξ(r) while approximately preserving its area. This evolution resembles a diffusion process in which the bump width σbao is the quadrature sum of the linear theory width and a length proportional to the rms relative displacement Σpair(rbao) of particle pairs separated by rbao. For n=-0.5 and n=-1, we find no detectable shift of the location of the BAO peak, but the peak in the n=-1.5 model shifts steadily to smaller scales, following rpeak/rbao=1-1.08(r0/rbao)1.5. The perturbation theory scheme of McDonald (2007) [P. McDonald, Phys. Rev. DPRVDAQ1550-7998 75, 043514 (2007).10.1103/PhysRevD.75.043514] and, to a lesser extent, standard 1-loop perturbation theory are fairly successful at explaining the nonlinear evolution of the Fourier power spectrum of our models. Analytic models also explain why the ξ(r) peak shifts much more for n=-1.5 than for n≥-1, though no ab initio model we have examined reproduces all of our numerical results. Simulations with Lbox=10rbao and Lbox=20rbao yield consistent results for ξ(r) at the BAO scale, provided one corrects for the integral constraint imposed by the uniform density box.

  9. Effects of Initial Conditions on Compressible Mixing in Supernova-Relevant Laboratory Experiments

    SciTech Connect

    Miles, A R; Edwards, M; Greenough, J

    2004-04-30

    In core-collapse supernovae, strong blast waves drive interfaces susceptible to Rayleigh-Taylor (RT), Richtmyer-Meshkov (RM), and Kelvin-Helmholtz (KH) instabilities. In addition, perturbation growth can result from material expansion in large-scale velocity gradients behind the shock front. Laser-driven experiments are designed to produce a strongly shocked interface whose evolution is a scaled version of the unstable hydrogen-helium interface in core-collapse supernovae such as SN 1987A. The ultimate goal of this research is to develop an understanding of the effect of hydrodynamic instabilities and the resulting transition to turbulence on supernovae observables that remain as yet unexplained. In this paper, we summarize recent results from our computational study of unstable systems driven by high Mach number shock and blast waves. For planar multimode systems, compressibility effects preclude the emergence of a regime of self-similar instability growth independent of the initial conditions (IC's) by allowing for memory of the initial conditions to be retained in the mix-width at all times. With higher-dimensional blast waves, divergence restores the properties necessary for establishment of the self-similar state, but achieving it requires very high initial characteristic mode number and high Mach number for the incident blast wave. Initial conditions predicted by some recent stellar calculations are incompatible with self-similarity.

  10. Reproductive characteristics of the Yangtze vole (Microtus fortis calamorum) under laboratory feeding conditions.

    PubMed

    Zhang, Meiwen; Han, Qunhua; Shen, Guo; Wang, Yong; Li, Bo; Guo, Cong; Zhou, Xunjun

    2016-01-01

    The reproductive characteristics of a laboratory population of the vole Microtus fortis calamorum were examined. Voles were allowed to breed under laboratory feeding conditions. Over a period of 3 months, 61.82% of the 110 vole pairs examined produced 3 or 4 litters. There were 1-9 voles in each litter and the mean litter size was 4.67±0.28 (mean±SE). Most litters included 3-7 young voles, accounting for 83.62% of all litters. The mean farrowing interval was 25.9 days (range from 19 to 95 days), and the most farrowing intervals were 20-25 days, accounting for 79.9% of the total. When based on litter size, the reproductive index was 6.23, but was 3.42 when based on pup survival. The survival rate of offspring to weaning was 55.03%. The high rate of infanticide that occurred after removal of males from cages indicates that, in the laboratory, both parents need to be present prior to weaning. PMID:26617078

  11. 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.

  12. [Obtaining of egg masses of the snail, Strombus pugilis (Mesogastropoda: Strombidae) under laboratory conditions].

    PubMed

    Góngora Gómez, Andrés Martin; Domínguez Orozco, Ana Laura; Muñoz Sevilla, Norma Patricia; Rodríguez Gil, Luis Alfonso

    2007-03-01

    The survival, reproduction and embryonic development of Strombus pugilis, were determined during a period of ten months under laboratory conditions. Seven progenitors were collected in Contoy Island, Quintana Roo, Mexico and later transferred to the laboratory, where they were placed in aquarium with 80 1 of sea water and fed with "pellets". A total of 30 egg masses were collected, one on September and the other on April. The estimated total length of one egg mass was 11.24 m; the mean number of embryos obtained per 2 cm was 264, obtaining an estimated total of 157 500 embryos in the egg mass. The means of the physical-chemical parameters during the study were: salinity 37.6 +/- 0.5% per hundred, pH 7.5 +/- 0.5 and temperature 28 +/- 0.2 degrees C. The maintenance and water recirculation system used to sustain the breading stock is excellent both for reproduction of the organism and for obtaining egg masses under controlled conditions. PMID:18457126

  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. 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

  15. 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.

  16. 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

  17. 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.

  18. Organics on Mars: Laboratory studies of organic material under simulated martian conditions

    NASA Astrophysics Data System (ADS)

    ten Kate, Inge Loes

    2006-01-01

    The search for organic molecules and traces of life on Mars has been a major topic in planetary science for several decades, and is the future perspective of several missions to Mars. In order to determine where and what those missions should be looking for, laboratory experiments under simulated Mars conditions have been performed. This thesis describes the effects of simulated martian surface conditions on organic material (amino acids) and living organisms (halophilic archaea). Experiments have been performed to study the stability of thin films of glycine and alanine against UV irradiation under different conditions. Thin films of glycine and alanine have a half-life of 22 ± 5 hours and 3 ± 1 hours, respectively, when extrapolated to Mars-like UV flux levels in vacuum. The presence of a 7 mbar CO2 atmosphere does not affect these destruction rates. Cooling the thin films to 210 K (average Mars temperature) lowers the destruction rate by a factor of 7. The intrinsic amino acid composition of two martian soil analogues, JSC Mars-1 and Salten Skov, has been investigated. The results demonstrated that these analogues are inappropriate for a life-science study in their raw state. Besides amino acids, the response of the halophilic archaea Natronorubrum sp. strain HG-1 to Mars-like conditions, such as low pressure, UV radiation and low temperatures, has been studied. From the results we concluded that this strain would not be a good model organism to survive on the surface of Mars.

  19. Zoeal stages of Labidochirus anomalus (Balss, 1913) (Decapoda: Anomura: Paguridae) obtained under laboratory conditions.

    PubMed

    Kornienko, Elena S; Korn, Olga M

    2015-01-01

    Zoeal stages of the hermit crab Labidochirus anomalus (Balss, 1913) (Decapoda: Anomura: Paguridae) are described and illustrated from the larvae reared in the laboratory. The development included four zoeal stages following the typical pattern in the Paguridae. Morphological features of the larvae of L. anomalus are compared with those described for the related species L. splendescens (Owen, 1839). The larvae of both species share numerous zoeal characters and are similar as the species of one genus. At the same time, zoeae of L. anomalus have no dorsal carina on the carapace and long posterolateral carapace spines-key features of the larvae of L. splendescens. These zoeal characters considered as generic are not characteristic of only the genus Labidochirus but sporadically occur among Pagurus species. Main characters of zoeal stages allow assignment of both Labidochirus species to the Group A of Pagurus (the typical representative P. bernhardus). PMID:26624306

  20. Laboratory Equipment for Investigation of Coring Under Mars-like Conditions

    NASA Astrophysics Data System (ADS)

    Zacny, K.; Cooper, G.

    2004-12-01

    To develop a suitable drill bit and set of operating conditions for Mars sample coring applications, it is essential to make tests under conditions that match those of the mission. The goal of the laboratory test program was to determine the drilling performance of diamond-impregnated bits under simulated Martian conditions, particularly those of low pressure and low temperature in a carbon dioxide atmosphere. For this purpose, drilling tests were performed in a vacuum chamber kept at a pressure of 5 torr. Prior to drilling, a rock, soil or a clay sample was cooled down to minus 80 degrees Celsius (Zacny et al, 2004). Thus, all Martian conditions, except the low gravity were simulated in the controlled environment. Input drilling parameters of interest included the weight on bit and rotational speed. These two independent variables were controlled from a PC station. The dependent variables included the bit reaction torque, the depth of the bit inside the drilled hole and the temperatures at various positions inside the drilled sample, in the center of the core as it was being cut and at the bit itself. These were acquired every second by a data acquisition system. Additional information such as the rate of penetration and the drill power were calculated after the test was completed. The weight of the rock and the bit prior to and after the test were measured to aid in evaluating the bit performance. In addition, the water saturation of the rock was measured prior to the test. Finally, the bit was viewed under the Scanning Electron Microscope and the Stereo Optical Microscope. The extent of the bit wear and its salient features were captured photographically. The results revealed that drilling or coring under Martian conditions in a water saturated rock is different in many respects from drilling on Earth. This is mainly because the Martian atmospheric pressure is in the vicinity of the pressure at the triple point of water. Thus ice, heated by contact with the

  1. Life cycle of Ixodes (Ixodes) loricatus (Acari: Ixodidae) under laboratory conditions.

    PubMed

    Schumaker, T T; Labruna, M B; Abel, I dos S; Clerici, P T

    2000-09-01

    The life cycle of Ixodes (Ixodes) loricatus Neumann, reared in the laboratory, is described. Engorged females collected from opossums trapped in the states of Minas Gerais and São Paulo, Brazil, which were used to start the laboratory colonies, were designated as BMG and CSP, respectively. Larval and nymphal ticks from both colonies fed separately on Rattus norvergicus Berkenhout or Calomys callosus Rengger, whereas Didelphis marsupialis L and Didelphis albiventris Lund were used as hosts for BMG and CSP adults, respectively. Biological and developmental data obtained from ticks of both the BMG and CSP colonies that were reared separately for two consecutive generations were compared. The percentage of fed or molted ticks reared on C. callosus was higher than that recorded for ticks fed on R. norvergicus in the majority of the observations. Despite significant differences among several of the biological parameters, the pattern of the life cycles of the two tick colonies was similar. Results indicated that the mean life cycle duration of I. (I.) loricatus was approximately 7 mo from parental oviposition to the occurrence of F1 eggs, regardless of geographic origin or host species. PMID:11004783

  2. Wear Independent Similarity.

    PubMed

    Steele, Adam; Davis, Alexander; Kim, Joohyung; Loth, Eric; Bayer, Ilker S

    2015-06-17

    This study presents a new factor that can be used to design materials where desired surface properties must be retained under in-system wear and abrasion. To demonstrate this factor, a synthetic nonwetting coating is presented that retains chemical and geometric performance as material is removed under multiple wear conditions: a coarse vitrified abradant (similar to sanding), a smooth abradant (similar to rubbing), and a mild abradant (a blend of sanding and rubbing). With this approach, such a nonwetting material displays unprecedented mechanical durability while maintaining desired performance under a range of demanding conditions. This performance, herein termed wear independent similarity performance (WISP), is critical because multiple mechanisms and/or modes of wear can be expected to occur in many typical applications, e.g., combinations of abrasion, rubbing, contact fatigue, weathering, particle impact, etc. Furthermore, these multiple wear mechanisms tend to quickly degrade a novel surface's unique performance, and thus many promising surfaces and materials never scale out of research laboratories. Dynamic goniometry and scanning electron microscopy results presented herein provide insight into these underlying mechanisms, which may also be applied to other coatings and materials. PMID:26018058

  3. Monoaromatic hydrocarbon transformation under anaerobic conditions at Seal Beach, California: Laboratory studies

    SciTech Connect

    Ball, H.A.; Reinhard, M.

    1996-02-01

    Anaerobic biotransformation of several aromatic hydrocarbons found in gasoline including benzene, toluene, ethylbenzene, m-xylene, p-xylene, and o-xylene (BTEX) was studied in batch anaerobic laboratory microcosms. Aquifer sediment and ground water were obtained from the site of a historic gasoline spill at Seal Beach, California. Sulfate is present in the site ground water at 80 mg/L, and sulfate-reducing activity appears to be the dominant intrinsic BTEX bioremediation process where nitrate is absent. In the laboratory, the microcosms were set up with different electron acceptors (sulfate and nitrate) in site ground water and various defined anaerobic media to estimate intrinsic biodegradation rates and to suggest conditions under which anaerobic bioremediation could be enhanced. In unamended microcosms, anaerobic biotransformation of toluene and m + p-xylene occurred at a rate of 7.2 and 4.1 {micro}g/liter hr, respectively, with sulfate as the apparent electron acceptor. Addition of nitrate stimulated nitrate-reducing conditions and increased rates of toluene and m + p-xylene biotransformation to 30.1 and 5.4 {micro}g/liter hr, respectively. The catabolic substrate range was altered to include ethylbenzene in the nitrate-amended microcosms, suggesting an apparent preferential use of different BTEX compounds depending on the electron acceptor available. Under all the conditions studied, more than twice the amount of nitrate or sulfate was used than could be accounted for by the observed BTEX degradation. The results of these experiments indicate that indigenous microorganisms from the Seal Beach aquifer have significant capability to degrade BTEX hydrocarbons and that intrinsic processes in the Seal Beach aquifer may remediate a portion of the hydrocarbon contamination in situ without intervention. However, the data also suggest that intervention by nitrate addition would enhance the rate and extent of anaerobic BTEX biotransformation.

  4. Validity and reliability of the T-Scan(®) III for measuring force under laboratory conditions.

    PubMed

    Cerna, M; Ferreira, R; Zaror, C; Navarro, P; Sandoval, P

    2015-07-01

    Although measuring bite force is an important indicator of the health of the masticatory system, few commercially available transducers have been validated for routine clinical use. T-Scan(®) III Occlusal Analysis System allows to record the bite force distribution, indicating its relative intensity and occlusal timing. Nevertheless, even fewer studies have evaluated the validity and reliability of the latest generation of the T-Scan(®) occlusal analysis system. To determine the validity and reliability of the T-Scan(®) III system when measuring total absolute bite force under laboratory conditions. Known forces were applied to 18 T-Scan(®) III sensors, which were classified into two groups differentiated by their production series. Both Lin's concordance correlation coefficient (CCC) and the intra-class correlation coefficient (ICC) were used to assess the system's reliability and validity. Considering all the sensors studied, a substantial level (Lin's CCC 0·969) and a very good level of reliability (CCI 0·994) were obtained. When evaluating the validity of the system, a poor (Lin's CCC 0·530) and moderate (ICC 0·693) agreement were also obtained. The main factor that negatively influenced the validity of the T-Scan(®) III under these study conditions was the significant difference in the behaviour of the two sensor groups. The T-Scan(®) III showed a high degree of reliability when used to perform consecutive measurements. However, the system showed an insufficient degree of validity for measuring absolute force when estimating total occlusal force under laboratory conditions. PMID:25727489

  5. 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. PMID:20302536

  6. 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.

  7. 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.

  8. Condition assessment of the Los Alamos National Laboratory radioactive liquid waste collection system.

    SciTech Connect

    Edgemon, G. L.; Moss, W. D.; Worland, V. P.

    2004-01-01

    The radioactive liquid waste collection system (RLWCS) at Los Alamos National Laboratory (LANE) is a site-wide double-encased piping system installed in 1982 that allows radioactive liquid waste (RLW) producing facilities to gravity drain their waste to the radioactive liquid waste treatment facility (RLWTF) through a system of underground high-density polyethylene (HDPE) pipes and vaults. The RLWCS stretches approximately four miles and typically receives approximately 10,000 gallons of RLW per day for treatment at the RLWTF. Uncertainty of the current condition of the RLWCS was recently identified as a potential risk to the future continued availability of the RLW treatment function. A condition assessment was performed in April 2004 to evaluate the risks and estimate the remaining useful life of the existing RLWCS. Several representative and 'worst-case' RLWCS primary piping sections and their associated inspection vaults were selected for direct visual assessment, remote borescopic examination, and in-situ durometer testing. This field investigation combined with an RLWCS materials compatibility review showed that the primary piping of the RLWCS is in relatively good condition, with only a few noteworthy areas of degradation.

  9. 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.

  10. Dissipation and adsorption of isoproturon, tebuconazole, chlorpyrifos and their main transformation products under laboratory and field conditions.

    PubMed

    Papadopoulou, Evangelia S; Karas, Panagiotis A; Nikolaki, Sofia; Storck, Veronika; Ferrari, Federico; Trevisan, Marco; Tsiamis, George; Martin-Laurent, Fabrice; Karpouzas, Dimitrios G

    2016-11-01

    Assessment of dissipation constitutes an integral part of pesticides risk assessment since it provides an estimate of the level and the duration of exposure of the terrestrial ecosystem to pesticides. Within the frame of an overall assessment of the soil microbial toxicity of pesticides, we investigated the dissipation of a range of dose rates of three model pesticides, isoproturon (IPU), tebuconazole (TCZ), and chlorpyrifos (CHL), and the formation and dissipation of their main transformation products following a tiered lab-to-field approach. The adsorption of pesticides and their transformation products was also determined. IPU was the least persistent pesticide showing a dose-dependent increase in its persistence in both laboratory and field studies. CHL dissipation showed a dose-dependent increase under laboratory conditions and an exact opposite trend in the field. TCZ was the most persistent pesticide under lab conditions showing a dose-dependent decrease in its dissipation, whereas in the field TCZ exhibited a biphasic dissipation pattern with extrapolated DT90s ranging from 198 to 603.4days in the ×1 and ×2 dose rates, respectively. IPU was demethylated to mono- (MD-IPU) and di-desmethyl-isoproturon (DD-IPU) which dissipated following a similar pattern with the parent compound. CHL was hydrolyzed to 3,5,6-trichloro-2-pyridinol (TCP) which dissipated showing a reverse dose-dependent pattern compared to CHL. Pesticides adsorption affinity increased in the order IPU

  11. 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.

  12. Use of crop residues for the control of Meloidogyne incognita under laboratory conditions.

    PubMed

    Piedrabuena, Ana; García-Alvarez, Avelino; Díez-Rojo, Miguel A; Bello, Antonio

    2006-10-01

    This laboratory study evaluates the biofumigant effect of different organic materials with the aim of developing non-chemical alternatives for the management of Meloidogyne incognita (Kofoid & White) Chitwood populations. Sources of organic material from the production system were selected with the aim of reducing agricultural residue accumulation problems as well as decreasing the costs due to the use of chemical fertilizers and pesticides. The selected materials were residues from pepper, strawberry, tomato and cucumber crops, orange juice industry residues, commercial manure and sheep manure, applied at different dosages. Two biofumigation assays were performed under laboratory conditions, using alkaline soils from the Torreblanca area (Murcia, Spain) and acidic soils from the Villa del Prado area (Madrid, Spain). The assays evaluated the effect of the treatments on M. incognita juveniles and other soil organisms, the nematode galling index on tomato roots (susceptible cv. Marmande) grown in the biofumigated soil and soil fertility parameters. The results showed that all biofumigant materials significantly decreased M. incognita populations and galling indices in tomato cv. Marmande. A greater effect was observed on galling indices when applying crop residues together with manure than with the residues alone. Biofumigation had a general beneficial effect on soil fertility, generally increasing nitrogen, organic carbon, pH and potassium levels, and also calcium levels when crop residues of pepper and strawberry were applied. There were no important variations in the number of saprophagous nematodes, dorylaimids and enchytraeids. PMID:16927410

  13. 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. PMID:8972837

  14. Increase in developmental instability in a field-collected Chironomus population maintained under laboratory conditions.

    PubMed

    Arambourou, Hélène; Branchu, Philippe; Beisel, Jean-Nicolas

    2015-06-01

    In order to be a relevant indicator of exposure towards teratogenic stressors, morphological defects should not be passed on to the next generation. In this study, we compare morphological variations in Chironomids collected from a contaminated river stretch with those of their progeny, reared in uncontaminated sediment under laboratory conditions. We focused on mentum defects (deformities, fluctuating asymmetry and mean shape change), measured by geometric morphometrics. We observed no significant variation in deformity rate between the parental generation and its progeny. On the contrary, we observed a significant increase in fluctuating asymmetry and a significant decrease in mentum centroid size in the offspring. Our results suggest that shape defects are not caused by direct exposure to teratogenic stressors alone. We propose four hypotheses to explain this: (a) teratogenic contaminants are present in egg-clutches, (b) contaminants at the sampling site have mutagenic effects, (c) costs of tolerance, and (d) contamination-induced genetic impoverishment. PMID:25749504

  15. 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. PMID:26070994

  16. Fate of plasticised PVC products under landfill conditions: a laboratory-scale landfill simulation reactor study.

    PubMed

    Mersiowsky, I; Weller, M; Ejlertsson, J

    2001-09-01

    The long-term behaviour of plasticised PVC products was investigated in laboratory-scale landfill simulation reactors. The examined products included a cable material and a flooring with different combinations of plasticisers. The objective of the study was to assess whether a degradation of the PVC polymer or a loss of plasticisers occurred under landfill conditions. A degradation of the polymer matrix was not observed. The contents of plasticisers in aged samples was determined and compared to the respective original products. The behaviour of the various plasticisers was found to differ significantly. Losses of DEHP and BBP from the flooring were too low for analytical quantification. No loss of DIDP from the cable was detectable, whereas DINA in the same product showed considerable losses of up to 70% compared to the original contents. These deficits were attributable to biodegradation rather than leaching. There was no equivalent release of plasticisers into the leachate. PMID:11487101

  17. Mating time of the West Indian fruit fly Anastrepha obliqua (Macquart) (Diptera: Tephritidae) under laboratory conditions.

    PubMed

    Henning, Frederico; Matioli, Sergio R

    2006-01-01

    Allochronic reproductive isolation seems to be an important factor in speciation processes in Tephritidae since specific mating times are a widespread feature of its species. The timing of matings of the West Indian fruit fly, Anastrepha obliqua (Macquart) was investigated through group-focal observations, during ten days, under laboratory conditions. The number of observed matings and males exhibiting calling behavior varied significantly according to time of day. Sexual activities seemed to be concentrated in the afternoon period, with the male calling behavior reaching a peak between 3:30p.m. and 4:30p.m., and mating occurred most frequently from 2:00 p.m. to 4:30 p.m. PMID:17352082

  18. Laboratory degradation rates of 11 pyrethroids under aerobic and anaerobic conditions.

    PubMed

    Meyer, Brian N; Lam, Chung; Moore, Sean; Jones, Russell L

    2013-05-22

    Degradation of 11 pyrethroids was measured over approximately 100 days in three sediment/water systems under aerobic and anaerobic conditions at 25 °C in the dark. The three California sediments represented a range of textures and organic matter. Test compounds were bifenthrin, cypermethrin, ζ-cypermethrin, cyfluthrin, β-cyfluthrin, deltamethrin, esfenvalerate, fenpropathrin, γ-cyhalothrin, λ-cyhalothrin, and permethrin. A non-standard design was employed to keep conditions essentially the same for all compounds. The test compounds were applied as two test mixtures (six active ingredients per mixture, with bifenthrin common to both) at approximately 50 μg of test compound/kg of sediment (dry weight). Extracts of sediment/water were cleaned up by solid-phase extraction, concentrated, and analyzed by gas chromatography/mass spectrometry (except deltamethrin) against matrix-matched standards, with cyfluthrin-d6 as an internal standard. Deltamethrin was analyzed by liquid chromatography/tandem mass spectrometry using deltamethrin-phenoxy-(13)C6 as an internal standard. Similar degradation rates of bifenthrin and for related isomeric compounds (e.g., cyfluthrin and β-cyfluthrin) were generally measured in both mixtures for each sediment. First-order half-lives under aerobic conditions ranged from 2.9 to greater than 200 days, with a median value of 18 days. Under anaerobic conditions, the range was from 20 to greater than 200 days, with a median value of 70 days. PMID:23641910

  19. Susceptibility of Tetranychus urticae Koch to an ethanol extract of Cnidoscolus aconitifolius leaves under laboratory conditions.

    PubMed

    Numa, S; Rodríguez, L; Rodríguez, D; Coy-Barrera, E

    2015-01-01

    One of the main pests of commercial rose crops in Colombia is the phytophagous mite Tetranychus urticae Koch. To manage this pest, synthetic chemicals have traditionally been used, some of which are well known to be potentially toxic to the environment and humans. Therefore, alternative strategies for pest management in greenhouse crops have been developed in recent years, including biological control with natural enemies such as parasitoids, predators and entomopathogenic microorganisms as well as chemical control using plant extracts. Such extracts have shown toxicity to insects, which has positioned them as a common alternative in programs of integrated pest management. The objective of this study was to evaluate the effect of an unfractionated ethanolic extract of Cnidoscolus aconitifolius leaves on adult females of T. urticae under laboratory conditions. The extract was chemically characterized by recording its metabolic profile via liquid chromatography coupled to mass spectrometry, along with tentative metabolite identification. The immersion technique and direct application to rose leaves were used to evaluate the effects of seven doses (10-2,000 µg/mL) of the ethanol extract of C. aconitifolius leaves on T. urticae females under laboratory conditions. The mortality and oviposition of individuals were recorded at 24, 48 and 72 h. It was found that the C. aconitifolius leaf extract reduced fertility and increased mortality in a dose-dependent manner. The main metabolites identified included flavonoid- and sesquiterpene-type compounds, in addition to chromone- and xanthone-type compounds as minor constituents with potential acaricidal effects. PMID:26185740

  20. 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.

  1. Seasonal changes in the thermoregulation of laboratory golden hamsters during acclimation to seminatural outdoor conditions.

    PubMed

    Jefimow, Małgorzata; Wojciechowski, Michał; Tegowska, Eugenia

    2004-11-01

    Proper adjustments of the thermoregulatory mechanisms ensure survival in the natural environment. In the present study, we tested the hypothesis that laboratory golden hamsters (Mesocricetus auratus) housed under seminatural outdoor conditions are able to acclimatize to daily and seasonal changes in the environment despite their long history of breeding in captivity. The animals experienced natural changes in the photoperiod and ambient temperature characteristic for central Poland. During experiments in the thermal gradient system, the daily rhythms of body temperature (measured as the temperature of brown adipose tissue, TBAT), preferred ambient temperature (PTa) and activity were measured in summer, autumn and spring. We found that mean TBAT was highest in autumn and least in summer, reflecting seasonal changes in the capacity for nonshivering thermogenesis (NST). In summer, TBAT followed the robust daily rhythm with the amplitude of 1.1+/-0.1 degrees C. This amplitude was depressed in autumn (0.2+/-0.1 degrees C) and partially restored in spring (0.4+/-0.1 degrees C). Seasonal changes in the daily amplitude of TBAT recorded during both transitional periods, i.e., in autumn and spring, seem to be associated with hamsters' hibernation. In autumn, mean daily PTa was lower than in summer and spring, indicating the lowering of a set point for core body temperature (Tb) regulation. Locomotor activity was much higher in spring than in summer and autumn, and it always predominated at night. We conclude that laboratory golden hamsters housed under seminatural conditions express daily and seasonal changes in the thermoregulatory mechanisms that, despite long history of breeding in captivity, enable proper acclimatization to seasonally changing environment and ensure successful hibernation and winter survival. PMID:15556395

  2. Load dissipation by corn residue on tilled soil in laboratory and field-wheeling conditions.

    PubMed

    Reichert, José M; Brandt, André A; Rodrigues, Miriam F; Reinert, Dalvan J; Braida, João A

    2016-06-01

    Crop residues may partially dissipate applied loads and reduce soil compaction. We evaluated the effect of corn residue on energy-applied dissipation during wheeling. The experiment consisted of a preliminary laboratory test and a confirmatory field test on a Paleaudalf soil. In the laboratory, an adapted Proctor test was performed with three energy levels, with and without corn residue. Field treatments consisted of three 5.1 Mg tractor wheeling intensities (0, 2, and 6), with and without 12 Mg ha(-1) corn residue on the soil surface. Corn residue on the soil surface reduced soil bulk density in the adapted Proctor test. By applying energy of 52.6 kN m m(-3) , soil dissipated 2.98% of applied energy, whereas with 175.4 kN m m(-3) a dissipation of 8.60% was obtained. This result confirms the hypothesis that surface mulch absorbs part of the compaction effort. Residue effects on soil compaction observed in the adapted Proctor test was not replicated under subsoiled soil field conditions, because of differences in applied pressure and soil conditions (structure, moisture and volume confinement). Nevertheless, this negative result does not mean that straw has no effect in the field. Such effects should be measured via stress transmission and compared to soil load-bearing capacity, rather than on bulk deformations. Wheeling by heavy tractor on subsoiled soil increased compaction, independently of surface residue. Two wheelings produced a significantly increase, but six wheelings did not further increase compaction. Reduced traffic intensity on recently tilled soil is necessary to minimize soil compaction, since traffic intensity show a greater effect than surface mulch on soil protection from excessive compaction. © 2015 Society of Chemical Industry. PMID:26304050

  3. Pathogenicity of the entomopathogenic fungus, Lecanicillium muscarium, against the sweetpotato whitefly Bemisia tabaci under laboratory and glasshouse conditions.

    PubMed

    Cuthbertson, Andrew G S; Walters, Keith F A

    2005-11-01

    The potential for using the entomopathogenic fungus Lecanicillium muscarium to control the sweetpotato whitefly, Bemisia tabaci has been established in the laboratory by other studies. Laboratory studies however frequently overestimate the level of control achieved by biological control agents in the glasshouse. Before full-scale commercial or field development is considered, glasshouse trials are required to confirm laboratory results. Under both controlled laboratory and glasshouse conditions high mortality of second instar B. tabaci was recorded after application of L. muscarium. The potential of incorporating L. muscarium into integrated pest management strategies for the control of B. tabaci is discussed. PMID:16244900

  4. 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.

  5. Comparison of the emission of IR decoy flare under controlled laboratory and on-field conditions

    NASA Astrophysics Data System (ADS)

    Sánchez Oliveros, Carmen; Martín Aragón, Laura; Macias Jareño, Raquel

    2009-09-01

    The knowledge of the optical properties of decoy flares such as peak intensity, rise time and function time as well as the trajectory after being ejected are crucial to ensure the decoy effectiveness and the protection of the aircraft. The Countermeasures Laboratory of the "Institute of technology Marañosa" (ITM) has performed a measurement campaign during the spring of 2008 to determine the IR decoy signature in both wind tunnel test and in-flight conditions. Both tests are complementary because of the different test conditions that influence the behavior of the flare burn profile. Deviations were found between two sets of data due to high wind-stream and high altitudes. Comparison of both sets of results allows extrapolating the measurements in stationary conditions to that of a real scenario. Besides, these comparisons are useful to validate IR flare emission simulation software. The radiant intensity and burn time was calculated trough a sequence of calibrated images. The effect of the influent parameter on the emitted intensity were also Identified and measured. Analysis of in-flight measurements took into account the altitude, aerodynamic conditions, angle aspect and of course the wind speed. Sky radiance and atmospheric transmittance were also calculated. The radiation measurements of IR flares on flight and wind tunnel test are performed with a MWIR camera equipped with a 350mm focal length lens. Besides the camera a Circular Variable Filter (CVF) spectrorradiometer was used for the tunnel test. For the field trial an automatic tracking system of targets were used in order to determine the flare trajectory.

  6. 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.

  7. 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.

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

    PubMed

    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

  9. 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

  10. 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

  11. 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

  12. Hydrological conditions at the 317/319 Area at Argonne National Laboratory

    SciTech Connect

    Patton, T.L.; Pearl, R.H.; Tsai, S.Y.

    1990-08-01

    This study examined the hydrological conditions of the glacial till underlying the 317/319 Area at Argonne National Laboratory (ANL) near Lemont, Illinois. The study's purpose was to review and summarize hydrological data collected by ANL's Environment, Safety, and Health Department and to characterize, based on these data, the groundwater movement and migration of potential contaminants in the area. Recommendations for further study have been made based on the findings of this review. The 317/319 Area is located between Meridian Road and the southern border of ANL. The 317 Area was commissioned in the late 1940s for the temporary storage of radioactive waste. Low- and high-level solid radioactive waste is stored in partially buried concrete vaults. Low-level radioactive waste awaiting shipment for off-site disposal is stored in aboveground steel bins north of the vaults. The 319 Area is an inactive landfill, located east of the 317 Area that was used for the disposal of general refuse, demolition debris, and laboratory equipment. Fluorescent light bulbs, chemical containers, and suspect waste were also placed in the landfill. Liquid chemical wastes were disposed of at each site in gravel-filled trenches called French drains.'' The 317/319 Area is underlain by a silty clay glacial till. Dolomite bedrock underlies the till at an average depth of about 19.5m. Organic contaminants and radionuclides have been detected in groundwater samples from wells completed in the till. Fractures in the clay as well as sand and gravel lenses present in the till could permit these contaminants to migrate downward to the dolomite aquifer. At the time of this report, no chemical quality analyses had been made on groundwater samples from the dolomite. The study found that existing information about subsurface characteristics at the site is inadequate to identify potential pathways for contaminant migration. 14 refs., 13 figs., 6 tabs.

  13. 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

  14. 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.

  15. 42 CFR 493.807 - Condition: Reinstatement of laboratories performing nonwaived testing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., subspecialty, or analyte, the laboratory must then demonstrate sustained satisfactory performance on two... Subspecialty for Laboratories Performing Tests of Moderate Complexity (Including the Subcategory), High... nonwaived testing. 493.807 Section 493.807 Public Health CENTERS FOR MEDICARE & MEDICAID...

  16. Quantifying soil surface photolysis under conditions simulating water movement in the field: a new laboratory test design.

    PubMed

    Hand, Laurence H; Nichols, Carol; Kuet, Sui F; Oliver, Robin G; Harbourt, Christopher M; El-Naggar, Essam M

    2015-10-01

    Soil surface photolysis can be a significant dissipation pathway for agrochemicals under field conditions, although it is assumed that such degradation ceases once the agrochemical is transported away from the surface following rainfall or irrigation and subsequent drainage of soil porewater. However, as both downward and upward water movements occur under field conditions, relatively mobile compounds may return to the surface, prolonging exposure to ultraviolet light and increasing the potential for degradation by photolysis. To test this hypothesis, a novel experimental system was used to quantify the contribution of photolysis to the overall dissipation of a new herbicide, bicyclopyrone, under conditions that mimicked field studies more closely than the standard laboratory test guidance. Soil cores were taken from 3 US field study sites, and the surfaces were treated with [(14) C]-bicyclopyrone. The radioactivity was redistributed throughout the cores using a simulated rainfall event, following which the cores were incubated under a xenon-arc lamp with continuous provision of moisture from below and a wind simulator to induce evaporation. After only 2 d, most of the test compound had returned to the soil surface. Significantly more degradation was observed in the irradiated samples than in a parallel dark control sample. Degradation rates were very similar to those observed in both the thin layer photolysis study and the field dissipation studies and significantly faster than in the soil metabolism studies conducted in the dark. Thus, for highly soluble, mobile agrochemicals, such as bicyclopyrone, photolysis is not terminated permanently by rainfall or irrigation but can resume following transport to the surface in evaporating water. PMID:26010776

  17. 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.

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... laboratory must have a clinical consultant who meets the qualification requirements of § 493.1417 of this... complexity testing; clinical consultant. 493.1415 Section 493.1415 Public Health CENTERS FOR MEDICARE... LABORATORY REQUIREMENTS Personnel for Nonwaived Testing Laboratories Performing Moderate Complexity...

  19. 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

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

    PubMed

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

    2013-11-01

    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

  1. 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

  2. Competitive Interactions between Immature Stages of Bactrocera cucurbitae (Coquillett) and Bactrocera tau (Walker) (Diptera: Tephritidae) under Laboratory Conditions.

    PubMed

    Shen, K; Hu, J; Wu, B; An, K; Zhang, J; Liu, J; Zhang, R

    2014-08-01

    The melon fly, Bactrocera cucurbitae (Coquillett), and the pumpkin fly, Bactrocera tau (Walker), are economically important pests that attack mainly cucurbitacean fruits. The two fruit fly species have similar natural distributions, host ranges, and population growth capacities. This study was designed to assess the asymmetrical competitions through resource exploitation between the larvae of B. cucurbitae and B. tau at different density levels and temperatures, and on different hosts by comparing the relative effects of interspecific and intraspecific interactions on four life history parameters: survival rate, puparial mass, puparial duration, and developmental duration. Our results showed that intraspecific and interspecific competitions occurred under some laboratory conditions, and B. cucurbitae took advantage over B. tau at the high-density level and at low and high temperatures on pumpkin, bitter gourd, and bottle gourd when interspecific competition took place. Intraspecific and interspecific competitions mainly affected the puparial mass and the survival rate of the two fruit fly species but had no marked effect on the puparial duration or development duration. PMID:27193811

  3. Life cycle and behavior of Amblyomma rotundatum (Acari: Ixodidae) under laboratory conditions and remarks on parasitism of toads in Brazil.

    PubMed

    Luz, Hermes Ribeiro; Faccini, João Luiz Horacio; Pires, Marcus Sandes; da Silva, Hélio Ricardo; Barros-Battesti, Darci Moraes

    2013-05-01

    The life cycle and behavior of Amblyomma rotundatum were evaluated under laboratory conditions. The experiment started with four engorged females collected from toads (Rhinella schneideri) naturally infested at the Pirapitinga Ecological Station in the state of Minas Gerais, Brazil. Developmental periods of free-living stages were assessed in an incubator at 27 ± 1 °C, >80 % RH and darkness. The complete life cycle, including pre-attachment periods for each parasitic stage, ranged from 126 to 228 days. The pre-attachment, feeding and molting periods increased as the life cycle progressed from larva to adult female. Oviposition lasted about 20 days, with the peak occurring on days 4 and 5. Longevity of nymphs and adult females was quite similar (approximately 250 and 240 days, respectively) and slightly longer than that of larvae. Lesions caused by tick feeding are discussed and a list of known hosts, including new host records for A. rotundatum, is offered. PMID:23100108

  4. 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.

  5. Persistence of cyfluthrin in three Malaysian agricultural soils under laboratory conditions.

    PubMed

    Lee-Yin, Choo; Ismaill, B S; Salmijah, S; Halimah, M

    2013-09-01

    The influence of temperature, moisture and organic matter on the persistence of cyfluthrin was determined using three types of Malaysian soils, namely clay, clay loam and sandy clay loam obtained from a tomato farm in Cameron Highlands, Pahang. The persistence of cyfluthrin was observed in the laboratory at two temperature levels of 25 and 35 degreeC and field water capacity of 30 and 80%. Treated soil samples were incubated in a growth chamber for 1, 2, 3, 5, 7, 10, 14, 21 and 28 days. The results from the incubation studies showed that temperature and organic matter content significantly reduced the half-life (t1/2) values of cyfluthrin in the three soil types, but moisture content had very little effect. It was observed that cyfluthrin persisted longer at lower temperature and moisture content and higher organic matter content in all the three soil types. The present study demonstrated that under the tropical conditions of Malaysia, cyfluthrin dissipated rapidly in soils compared to its dissipation in soils of temperate regions, evidently due to high temperature. PMID:24558812

  6. 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.

  7. [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. PMID:9685961

  8. Laboratory Measurements of the Millimeter-Wavelength Sulfur Dioxide Absorption Spectrum under Simulated Venus Conditions

    NASA Astrophysics Data System (ADS)

    Bellotti, Amadeo; Steffes, Paul G.

    2014-11-01

    Over 130 laboratory measurements of the 2-4 millimeter wavelength opacity of sulfur dioxide in a carbon dioxide atmosphere under simulated conditions for the upper Venus troposphere (temperatures between 308-343 K and pressures between 0.03- 2 bar) have been made. These measurements along with the centimeter wavelength measurements by Steffes et al. (Icarus, 2014, in press) have been used to empirically assess existing formalisms for sulfur dioxide opacity in a carbon dioxide atmosphere (Fahd and Steffes Icarus 97, 1992 and Suleiman et al. JGR 101, E2 1996). The Van Vleck and Weisskopf Model (VVW) used by Fahd and Steffes with the JPL rotational line catalog (Pickett, et al. JQSRT 60, 1998) was found to fit 85.88% of all 500 measurements within the 2-sigma uncertainty. This model was implemented in the new Georgia Tech Venus Radiative Transfer Model (GT-VRTM) which is capable of computing both disk-averaged and localized brightness temperatures of Venus. These are compared to observations. This work will improve retrievals of the atmospheric abundance of sulfur dioxide from observations of the Venus atmosphere. This work was supported by the NASA Planetary Atmospheres Program under Grant NNX11AD66G.

  9. 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. PMID:26147368

  10. Residues effects of isoproturon in mature earthworm (Aporrectodea caliginosa) under laboratory conditions.

    PubMed

    Youssef, Yahia; Mosleh, Ismaili

    2007-01-01

    This study was conducted to investigate the residues of isoproturon and its metabolites, 1-(4-isopropylphenyl)-3-methylurea, 1-(4-isopropylphenyl) urea, and 4-isopropylanilin in soil and mature earthworms under laboratory conditions. Mature earthworms (Aporrectodea caliginosa) were exposed for various durations (7, 15, 30, and 60 days) to soils contaminated with isoproturon concentrations (2, 4, 6, 8, and 10 mg.kg(-1) soil). The decrease in isoproturon concentration in the soil depended on initial concentration it was slower at higher concentrations. The isoproturon and its metabolites accumulated in earthworms it increased during the first 15 days and decreased thereafter. Acute toxicity of isoproturon was determined together with total soluble protein content and glycogen of worms. These parameters were related to isoproturon concentration in soil and earthworms. No lethal effect of isoproturon was observed even at the concentration 1000 mg.kg(-1) soil after 60 days of exposure. A reduction of total soluble protein was observed in all treated worms (maximum 59.54%). This study is suggesting the use of the total soluble protein content and glycogen of earthworms as biomarker of exposure to isoproturon. PMID:18399432

  11. 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. PMID:12877826

  12. Salmonella transfer potential during hand harvesting of tomatoes under laboratory conditions.

    PubMed

    Brar, Pardeepinder Kaur; Danyluk, Michelle D

    2013-08-01

    Tomato good agricultural practices, mandatory guidelines in Florida, do not have specific regulations for glove use during tomato harvesting. The objective of the research reported here was to evaluate Salmonella transfer from contaminated gloves to tomatoes and vice versa upon single and subsequent touches. Experiments were performed using mature, green, round tomatoes with two types of gloves (reusable and single use) and two hygienic conditions of reusable glove (clean and dirty [fouled with tomato leaves]). The transfer scenarios used during experiments were glove to tomato, tomato to glove, and glove to up to 25 subsequently touched tomatoes. The inoculated surface (6 log CFU per surface), after drying for 24 h, touched the uninoculated surface for 5 s. Salmonella populations from gloves and tomatoes were enumerated on nonselective and selective agar supplemented with 80 μg/ml rifampin. Enrichments were performed when counts fell below the detection limit. The rates of Salmonella transfer to tomatoes during a single touch were similar for single-use and reusable gloves; transfer from tomatoes to gloves was higher to single-use gloves than to reusable gloves under wet (0 h) inoculation conditions. Dirty reusable gloves did not transfer more Salmonella than clean reusable gloves during single contact under any conditions. When a single glove was sequentially touched to multiple tomatoes, clean reusable gloves transferred higher levels of Salmonella to the first few tomatoes touched than did single-use gloves and dirty reusable gloves. As workers' gloves became dirty over time during harvest, the risk of Salmonella transfer to tomatoes did not increase. PMID:23905789

  13. 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.

  14. 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

  15. 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.

  16. Control of Tick Infestations in Oryctolagus cuniculus (Lagomorpha: Leporidae) With Spinosad Under Laboratory and Field Conditions.

    PubMed

    ValcÁrcel, Félix; SÁnchez, J L Pérez; Jaime, J M Tercero; Basco-Basco, P I; Guajardo, S C Cota; Cutuli, M T; GonzÁlez, J; Olmeda, A S

    2015-03-01

    Because of great economic loss in the world's livestock industry, and the serious risks to human health, the control of ticks and tick-borne diseases is one of the most important health management issues today. Current methodology involves integrated tick control for preventing the development of resistance. Rabbits are hosts for immature stages of the three-host tick Hyalomma lusitanicum Koch; so, we focus on this host as a strategy to interrupt the tick life cycle. Spinosad is an insecticide-acaricide, produced by the fermentation of metabolites of the actinomycete bacterium Saccharopolyspora spinosa. We administered spinosad orally by force-feeding naturally and artificially infested rabbits, and under field conditions by administering treated food via a hopper during the period of peak infestation and reinfestation risk for rabbits. No living larvae were recovered from treated laboratory rabbits. In naturally infested rabbits, the number of live ticks collected from treated rabbits (mean = 0.62 ticks per ear) was significantly lower than those recovered from untreated rabbits (mean = 7.27; P < 0.001), whereas the number of dead ticks collected from untreated rabbits (mean = 6.53) was significantly lower than those recovered from treated rabbits (mean = 18.62; P < 0.001). In addition, free and continually reinfested rabbits freely ingested low doses of spinosad, reducing the tick burden from 48.00 (Day 0) to 26.09 ticks per ear in treated rabbits (Day 16), whereas controls maintained the infection (46.64). This strategy could be useful as an alternative or supplement to traditional acaricides in tick control programs. PMID:26336305

  17. The life cycle of Haemaphysalis qinghaiensis (Acari: Ixodidae) ticks under laboratory conditions.

    PubMed

    Ma, Miling; Guan, Guiquan; Chen, Ze; Liu, Zhijie; Liu, Aihong; Gou, Huitian; Ren, Qiaoyun; Li, Youquan; Niu, Qingli; Yang, Jifei; Yin, Hong; Luo, Jianxun

    2013-04-01

    The developmental stages in the life cycle of Haemaphysalis qinghaiensis were investigated under laboratory conditions. The larval, nymphal and adult ticks were fed on sheep at 25-27 °C, 50 % relative humidity (RH) and exposed to daylight. All free-living stages were maintained in an incubator (28 °C with 90 % RH and a 12-h photoperiod). The whole life cycle of H. qinghaiensis was completed in an average of 176 days (range 118-247 days). The average developmental periods were 34.44 days for egg incubation; 5.83, 4.20 and 33.70 days for larval pre-feeding, feeding and pre-molting; and 3.88, 5.30 and 46.50 days for nymphal pre-feeding, feeding and pre-molting. The average times for pre-feeding, feeding, pre-oviposition and oviposition of female adult ticks were 2.60, 11.40, 8.50, and 19.35 days, respectively. The results confirmed the positive correlation between the weight of the engorged female and the egg mass laid (r = 0.557, P < 0.05). The reproductive efficiency index and reproductive fitness index in females were 5.49 and 4.98, respectively. Engorged nymphs moulting to females (4.53 ± 0.16 mg) were significantly heavier (P < 0.001) than those moulting to males (3.45 ± 0.19 mg). The overall sex ratio of the adult ticks was 1:1.1 (M:F). PMID:23111808

  18. Scale effect on runoff and soil loss control using rice straw mulch under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Sadeghi, S. H. R.; Gholami, L.; Sharifi, E.; Khaledi Darvishan, A.; Homaee, M.

    2015-01-01

    Amendments can control the runoff and soil loss by protecting the soil surface. However, scale effects on runoff and soil loss control have not been considered yet. The present study has been formulated to determine the efficiency of two plot sizes of 6 and 0.25 m2 covered by 0.5 kg m-2 of straw mulch with regard to changing the time to runoff, runoff coefficient, sediment concentration and soil loss under laboratory conditions. The study used a sandy-loam soil taken from summer rangeland, Alborz Mountains, northern Iran, and was conducted under simulated rainfall intensities of 50 and 90 mm h-1 and in three replicates. The results of the study showed that the straw mulch had a more significant effect on reducing the runoff coefficient, sediment concentration and soil loss on a 0.25 m2 plot scale. The maximum effectiveness in time to runoff for both the scales was observed at a rainfall intensity of 90 mm h-1. The maximum increasing and decreasing rates in time to runoff and runoff coefficient were observed at a rainfall intensity of 90 mm h-1, with 367.92 and 96.71% for the 0.25 m2 plot and 110.10 and 15.08% for the 6 m2 plot. The maximum reduction in the runoff coefficient was in the 0.25 m2 plot for the two rainfall intensities of 50 and 90 mm h-1, with rates of -89.34 and -96.71%. The maximum change in soil loss at the intensities of both 50 and 90 mm h-1 occurred in the 0.25 m2 plot, with 100%, whereas in the 6 m2 plot, decreasing rates of soil loss for the intensities of both 50 and 90 mm h-1 were 46.74 and 63.24%, respectively.

  19. Scale effect on runoff and soil loss control using rice straw mulch under laboratory conditions

    NASA Astrophysics Data System (ADS)

    Sadeghi, S. H. R.; Gholami, L.; Sharifi Moghadam, E.; Khaledi Darvishan, A.

    2014-10-01

    Amendments can control the runoff and soil loss by protecting soil surface. However, scale effects on runoff and soil loss control has not been considered yet. The present study has been formulated to determine the efficiency of two plot sizes of 6 and 0.25 m2 covered by straw mulch with rate of 0.5 kg m-2 in changing the time to runoff, runoff coefficient, sediment concentration and soil loss under laboratory conditions. The study has been conducted for a sandy-loam soil taken from summer rangeland, Alborz Mountains, Northern Iran under simulated rainfall intensities of 50 and 90 mm h-1 and in 3 replicates. The results of the study showed that the straw mulch had more significant effect in in reducing runoff coefficient, sediment concentration and soil loss at 0.25 m2 plot scale. The maximum effectiveness in time to runoff for both the scales, observed in rainfall intensity of 90 mm h-1. The maximum increasing and decreasing rates in time to runoff and runoff coefficient observed in the rainfall intensity of 90 mm h-1 with the amounts of 367.92 and 96.71% for 0.25 m2 plot and the amounts of 110.10 and 15.08% for 6 m2 plot respectively. The maximum change of soil loss in both the intensities of 50 and 90 mm h-1 occurred at 0.25 m2 plot with the amount of 100% whereas at 6 m2 plot, decreasing rates of soil loss for in both the intensities of 50 and 90 mm h-1 were 46.74 and 63.24%, respectively.

  20. Modification of the tree root electrical capacitance method under laboratory conditions.

    PubMed

    Kormanek, Mariusz; Głąb, Tomasz; Klimek-Kopyra, Agnieszka

    2016-01-01

    For many years, scientists have been searching for nondestructive methods for the measurement of plant root system parameters. The measurement of electrical capacitance (EC) across the root has been proposed as one such nondestructive method. This article presents a study on the determination of relationships between EC measurement and the shape and size of the electrodes immersed in medium that are used for measurement. Measurement of EC and the parameters characterizing root systems of 1-year-old seedlings of the common beech Fagus sylvatica L. was conducted under laboratory conditions. The measurements of EC were performed between seedling root systems and two different electrodes in the form of a cylinder or a rectangular plate. Statistically significant correlations were found between the capacitance and root system parameters in both the variants; however, the correlations were higher in the case of the flat rectangular plate. Correlation coefficient (r) between EC and total root length was  0.688 for cylindrical electrode and  0.802 for rectangular plate, for total root area 0.641 and 0.818, and for dry weight of root system 0.502 and 0.747. The best-fitted linear regression relationships between the EC and the measured parameters were characterized by low determination coefficients in variants with cylindrical electrodes, and higher with flat rectangular plate electrodes. The results indicated that a two-dielectric media concept is a better model than Dalton's model when attempting to interpret the behavior of root and soil capacitance. The different electrodes probably allow root capacitance measurements to be interpreted from different aspects. However, this hypothesis requires further verification. PMID:26420794

  1. Efficacy of cyantraniliprole fly bait against housefly (Musca domestica L.) under laboratory conditions.

    PubMed

    Li, Q F; Li, X; Hunag, J B; Zhang, D M; Yuan, J Z

    2015-09-01

    Novel and effective baits are needed to manage pest housefly populations and avoid the development of insecticide resistance. In this study, we bioassayed the efficacy of Zyrox®, a novel fly bait containing a novel 0.5 % cyantraniliprole insecticide, to kill adult houseflies under laboratory conditions. We found that Zyrox® killed a significantly greater proportion of flies than the current competing fly bait, QuickBayt®, after a 24-h exposure. The cumulative mortalities of houseflies were up to 96.36 % and 92.57 % for Zyrox® and 78.88 % and 68.76 % for QuickBayt® in no-choice and choice tests, respectively. Our results suggested that there was negligible behavioral resistance to both fly baits but revealed that Zyrox® appeared to work slower than QuickBayt® (at a 3-h exposure, proportionally fewer flies were killed by Zyrox® than by QuickBayt®). Importantly, we found that the efficacy of Zyrox® did not diminish with the age of the bait (up to 90 days old). In actual knockdown time (KDT) feeding bioassay, the results showed that Zyrox® knocked down flies significantly slower (11.97 min for females; 12.30 min for males) than QuickBayt® (1.89 min for females; 2.24 min for males). These results reveal the high efficacy of Zyrox® bait to kill adult flies and suggest that it is a promising slow-action bait for management of houseflies. PMID:26113508

  2. Effects of Mirazid® and myrrh volatile oil on adult Fasciola gigantica under laboratory conditions

    PubMed Central

    Massoud, AM; Shalaby, HA; El Khateeb, RM; Mahmoud, MS; Kutkat, MA

    2012-01-01

    Objective To evaluate the effects of Mirazid® and myrrh volatile oil on adult Fasciola gigantica (F. gigantica ) under laboratory conditions. Methods The effects of oleoresin extract of myrrh (Mirazid®) and myrrh volatile oil on the surface morphology of adult F. gigantica following treatment in vitro had been determined by scanning electron microscopy. The results were compared with those observed in the fluke tegument following incubation in triclabendazole sulphoxide (TCBZ-SO), active form, (Fasinex®, Ciba-Geigy). Results Observations of the efficacy of Mirazid® oleoresin extract and myrrh volatile oil indicated that both products showed dose-dependent anthelmintic efficacy. The anterior half of the fluke was consistently more severely affected than the posterior half. The surface changes induced by Mirazid® oleoresin extract were less severe than those observed after exposure to either myrrh volatile oil or TCBZ-SO. Flukes showed swelling after these treatments, but its level and blebbing were much greater with myrrh volatile oil; in which patches of tegumental sloughing were observed in the apical cone and the posterior mid-body region of flukes. This was not observed after treatment with Mirazid® oleoresin extract. Conclusions The comparatively more disruption, observed in myrrh volatile oil exposed specimens, compared to that exposed to Mirazid® oleoresin extract might suggest that the anthelmintic activity of Mirazid® oleo resin extract was attributed to its content of volatile oil. So, increasing the concentration of myrrh volatile oil in Mirazid® might possibly help to developing its anthelmintic activity. PMID:23569864

  3. Laboratory measurements and modeling of metal-humic interactions under estuarine conditions

    NASA Astrophysics Data System (ADS)

    Hamilton-Taylor, J.; Postill, A. S.; Tipping, E.; Harper, M. P.

    2002-02-01

    Equilibrium dialysis was used to measure Co- and Cu-binding by an isolated peat humic acid (PHA) in controlled laboratory experiments under simulated estuarine conditions: ionic strengths of 0.005 to 0.7 M in NaCl and mixed Na-Mg-Ca chloride solutions, with trace metal concentrations of ˜5 × 10 -7 M, a PHA concentration of 10 mg/L, and at constant pH values of ˜7.8 (Co and Cu) and ˜4.6 (Cu only). Generally, Co- and Cu-humic binding decreased substantially with increasing ionic strength and, in the case of Cu, with decreasing pH. The presence of seawater concentrations of Ca and Mg had a relatively small effect on Co-humic binding and no measurable effect on that of Cu under the experimental conditions. The binding data were well-described by an equilibrium speciation code (the Windermere Humic Aqueous Model, WHAM) after optimising the fits by varying the metal-proton exchange constants for humic acid within justifiable limits (i.e., within 1 standard deviation of the mean exchange constants used in the WHAM database). The main factor producing the observed variations in metal-humic binding at constant pH was the electrostatic effect on the humic molecule. WHAM was used to predict Co- and Cu-humic binding in simulations of real estuaries. Co-humic binding is predicted to be relatively unimportant (generally <5% of total Co), whereas the Cu-humic complex is likely to be the dominant species throughout an estuary. The main factors producing changes in Co- and Cu-humic binding in the real-estuary simulations are the electrostatic effect on the humic molecule, ligand competition (mainly from carbonate species) for metals, and to a lesser extent Ca and Mg competition for humic binding sites. Variations in pH are significant only at the freshwater end of an estuary. WHAM simulations also indicated that competition effects between metals are more likely to occur in freshwaters than in seawater, due to enhanced electrostatic binding at low ionic strength.

  4. 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

  5. Efficacy of the entomopathogenic nematode, Steinernema feltiae, against sweetpotato whitefly Bemisia tabaci (Homoptera: Aleyrodidae) under laboratory and glasshouse conditions.

    PubMed

    Cuthbertson, A G S; Walters, K F A; Northing, P; Luo, W

    2007-02-01

    The potential of using the entomopathogenic nematode Steinernema feltiae to control the sweetpotato whitefly Bemisia tabaci (Gennadius) has been established in previous laboratory studies. However, laboratory studies can overestimate the level of control achieved by biocontrol agents in the glasshouse. Glasshouse trials are therefore required to confirm laboratory results before full-scale commercial development is considered. Under both controlled laboratory and glasshouse conditions high mortality of second instar B. tabaci (>90% and >80%, respectively) was recorded after application of S. feltiae. The efficacy of the biocontrol agent at various application rates was also investigated, where halving the rate of S. feltiae application caused no significant reduction in B. tabaci mortality on tomato foliage. Steinernema feltiae has shown much potential for incorporation into integrated pest management strategies for the control of B. tabaci. PMID:17298677

  6. 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 & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM SUPPLEMENTARY MEDICAL INSURANCE (SMI) BENEFITS Medical and Other...

  7. 40 CFR Appendix G to Subpart A of... - UNEP Recommendations for Conditions Applied to Exemption for Essential Laboratory and Analytical...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false UNEP Recommendations for Conditions Applied to Exemption for Essential Laboratory and Analytical Uses G Appendix G to Subpart A of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  8. 40 CFR Appendix G to Subpart A of... - UNEP Recommendations for Conditions Applied to Exemption for Essential Laboratory and Analytical...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 17 2011-07-01 2011-07-01 false UNEP Recommendations for Conditions Applied to Exemption for Essential Laboratory and Analytical Uses G Appendix G to Subpart A of Part 82 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE Production...

  9. 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 ...

  10. 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...

  11. 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 ...

  12. 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

  13. Laboratory simulations under martian environmental conditions: water vs. brine flowing over a sloping substrate

    NASA Astrophysics Data System (ADS)

    Conway, Susan; Gourronc, Marrine; Patel, Manish

    2013-04-01

    There are many observations that indicate that liquid water has been recently flowing on Mars' surface: for example at the present day 10m-scale lobate flows have been observed to occur each spring, termed "recurring slope linae" [1] and kilometre-scale gullies [2] are known to have been active in the recent past (<5 Ma) [3-4]. However, the temperature and pressure are too low, at present for liquid water to be stable, and similar conditions are thought to extend into the recent past. A possible solution to this paradox is that these flows are not pure water, but brines, that are stable under much lower temperature conditions. The static behaviour of brines at low pressure and low temperature has already been investigated [e.g. 5]; however the interaction of such brines flowing over sediment has not yet been explored. In this suite of experiments we aim to repeat the experiments performed by Conway et al. [6], in which a fixed volume of pure water was passed over an unstaturated, cold (-25°C) sediment bed (1x0.5m) at low pressure (7 mbar), but with brines of different concentrations. Our aims are to answer the following questions: 1.Are different quantities of water required to produce flows with the same runout length (measurable from orbit) but mediated by water or brine? 2. Do flows mediated by brine produce any distinctive behaviour or morphology that we could recognise at the martian surface? The suite of experiments are ongoing, but our initial experiments have already shown that for a given quantity of water, brine-flows are able to flow for much greater distances than pure water. Brine mediated flows are more than 4 times wider than their pure water counterparts. Once the flows are complete they freeze - this leaves a trace that has the same tone as the surrounding sediment in the case of water. In the case of brine there are both darker and lighter toned areas depending on the position in the flow-trace. Future analysis includes quantifying the amount of

  14. Elevated Bacterial Abundance in Laboratory-Grown and Naturally Occurring Frost Flowers Under Late Winter Conditions

    NASA Astrophysics Data System (ADS)

    Bowman, J. S.; Deming, J. W.

    2009-12-01

    Sea ice has been identified as an important microbial habitat, with bacteria and other microbes concentrated in the brine inclusions between ice crystals. Frost flowers, thought to draw brine from underlying sea ice, have not been characterized from a microbial standpoint. To test whether frost flowers serve as an upward vector of bacteria contained within sea ice brines we grew frost flowers in a freezer laboratory (air temperature of -21°C) from saline water spiked with the mesophilic (and thus passive under experimental conditions) bacterium Halomonas pacifica. Salinity of melted samples was measured and bacterial abundance determined by epifluorescent microscopy. Bacterial counts scaled to ice-melt volume averaged 2.82 x 106 ml-1 for frost flowers, compared to 9.47 x 105 ml-1 for underlying ice (3 x higher). Bacterial counts also correlated significantly with salinity (maximum value of 62.5 psu) for frost flowers, brine skim, and ice (df = 17, r = 0.59, p < 0.0001). Segregation coefficients were calculated to describe the efficiency of transport of both cells and salt from the starting solution into frost flowers. From these coefficients an enrichment index was calculated to test for bacterial concentration into frost flowers at a different rate than salt. Analysis with a Student’s T-test (df = 24, t = 0.306, p = .76) indicated that cells and salt were not transported into frost flowers with a significantly different efficiency. To test these findings in the field we then collected frost flowers (and related samples) from new sea ice near Barrow, Alaska in April 2009. Bacterial counts were significantly elevated (again, a 3-fold increase) in natural frost flowers (mean = 2.73 x 105 ml-1) compared to underlying sea ice (mean = 8.46 x 104 cells ml-1). For all field samples collected (frost flowers, underlying brine skim and sea ice, as well as snow), bacterial abundance correlated significantly with salinity (maximum value 124 psu, df = 40, r = 0.60, p < 0

  15. 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

  16. 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

  17. 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

  18. 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

  19. Settling and Ovipositional Behavior of Bactericera cockerelli (Hemiptera: Triozidae) on Solanaceous Hosts Under Field and Laboratory Conditions.

    PubMed

    Thinakaran, Jenita; Pierson, E A; Longnecker, M; Tamborindeguy, C; Munyaneza, J E; Rush, C M; Henne, D C

    2015-06-01

    Potato psyllid, Bactericera cockerelli (Šulc), is a seasonal insect pest in the Lower Rio Grande Valley of Texas, where it transmits the bacterial pathogen "Candidatus Liberibacter solanacearum" that causes zebra chip disease of potato. Studies were conducted to evaluate host preference of B. cockerelli adults for different plant species, and plant size and density. Settling and oviposition behavior of B. cockerelli was studied on its wild and cultivated solanaceous hosts, including potato, tomato, pepper, eggplant, and silverleaf nightshade, under both field and laboratory conditions. Naturally occurring B. cockerelli were used to evaluate host preference under open field conditions throughout the growing season. Settling and oviposition preference studies in the laboratory were conducted as cage-release experiments using pairs of plants, and observations were recorded over a 72-h period. Results of field trials indicated that naturally occurring B. cockerelli preferred potato and tomato equally for settling and oviposition, but settled on pepper, eggplant, and silverleaf nightshade only in the absence of potato and tomato. Under laboratory conditions, B. cockerelli adults preferred larger host plants, regardless of the species tested. Results also showed that movement of B. cockerelli was minimal after initial landing and settling behavior was influenced by host plant density. Lone plants attracted the most psyllids and can be used as sentinel plants to monitor B. cockerelli activity. Information from both field and laboratory studies demonstrated that not only host plant species determined host selection behavior of B. cockerelli adults, but also plant size and density. PMID:26470210

  20. 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

    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 key activity for this grant year has continued to be laboratory measurements of the microwave and millimeter-wave properties of the simulated atmospheres of the outer planets and their satellites. A Fabry-Perot spectrometer system capable of operation from 32 to 41 GHz was developed. Initially this spectrometer was used to complete laboratory measurements of the 7.5 to 9.3 mm absorption spectrum of ammonia. Laboratory measurements were begun at wavelengths near 3.2 mm, where a large number of observations of the emission from the outer planets were made. A description of this system is presented.

  1. 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

  2. SURVIVAL OF ESCHERICHIA COLI IN COW PATS IN PASTURE AND IN LABORATORY CONDITIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: To compare survival of E. coli in bovine feces deposited in a pasture or incubated in a controlled laboratory environment at comparable temperature regimes. Methods and Results: Fecal samples were collected from three cow herds on different diets. Samples were deposited as shaded and non-sha...

  3. 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...

  4. INTERACTIONS BETWEEN BACILLUS THURINGIENSIS SUBSP. ISRAELENSIS AND FATHEAD MINNOWS, PIMEPHALES PROMELAS RAFINESQUE, UNDER LABORATORY CONDITIONS

    EPA Science Inventory

    Interactions between Bacillus thuringiensis subsp. israelensis and fathead minnows, Pimephales promelas, were studied in laboratory exposures to two commercial formulations, Vectobac-G and Mosquito Attack. ortality among fatheads exposed to 2.0 x 10 6 to 6.5 x 10 6 CFU/ml with bo...

  5. Mating frequency of the male cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae), under laboratory conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the effects of three constant temperatures (20°, 25° and 30°C) on the rate of development and life history of the invasive cactus moth Cactoblastis cactorum (Berg). Results from these laboratory experiments were used to predict C. cactorum rate of development in the field during...

  6. Conditions for Building a Community of Practice in an Advanced Physics Laboratory

    ERIC Educational Resources Information Center

    Irving, Paul W.; Sayre, Eleanor C.

    2014-01-01

    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…

  7. 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...

  8. Effects of imidacloprid and deltamethrin on associative learning in honeybees under semi-field and laboratory conditions.

    PubMed

    Decourtye, Axel; Devillers, James; Cluzeau, Sophie; Charreton, Mercedes; Pham-Delègue, Minh-Hà

    2004-03-01

    We have compared the sublethal effects of two insecticides in the honeybee (imidacloprid and deltamethrin) in both semi-field and laboratory conditions. A sugar solution containing 24 microg kg(-1) of imidacloprid or 500 microg kg(-1) of deltamethrin was offered to a colony set in an outdoor flight cage. In contrast to imidacloprid, deltamethrin had lethal effect on workers bees. The contamination of syrup with imidacloprid or deltamethrin induced a decrease in both the foraging activity on the food source and activity at the hive entrance. Negative effects of imidacloprid were also observed in an olfactory learnt discrimination task. Free-flying foragers were taken from the contaminated feeder and subjected to a conditioned proboscis extension response (PER) assay under laboratory conditions. As with free-flying bees, no impact of deltamethrin was found on the learning performances of restrained individuals in the PER procedure, whilst significant effects were found with imidacloprid in both semi-field and laboratory conditions. PMID:15041263

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

    USGS Publications Warehouse

    Nichols, S. Jerrine

    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. 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.