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1

Conditioned Attraction, Similarity, and Evaluative Meaning.  

National Technical Information Service (NTIS)

Recent S-R formulations have indicated that similarity between persons functions as a UCS and that interpersonal attraction is a classically conditioned evaluative response. The thesis of the present study is that similarity is a correlate of evaluative m...

R. B. Stalling A. Staats

1969-01-01

2

Similarity Criteria for the Laboratory Simulation of Supernova Hydrodynamics  

Microsoft Academic Search

The conditions for validity and the limitations of experiments intended to simulate astrophysical hydrodynamics are discussed, with application to some ongoing experiments. For systems adequately described by the Euler equations, similarity criteria required for properly scaled experiments are identified. The conditions for the applicability of the Euler equations are formulated, based on the analysis of localization, heat conduction, viscosity, and

D. D. Ryutov; R. P. Drake; J. Kane; E. Liang; B. A. Remington; W. M. Wood-Vasey

1999-01-01

3

Conditional similarity reduction approach: Jimbo-Miwa equation  

NASA Astrophysics Data System (ADS)

The direct method developed by Clarkson and Kruskal (1989 J. Math. Phys. 30 2201) for finding the symmetry reductions of a nonlinear system is extended to find the conditional similarity solutions. Using the method of the Jimbo-Miwa (JM) equation, we find that three well-known (2+1)-dimensional models - the asymmetric Nizhnik-Novikov-Veselov equation, the breaking soliton equation and the Kadomtsev-Petviashvili equation - can all be obtained as the conditional similarity reductions of the JM equation.

Lou, Sen-yue; Tang, Xiao-yan

2001-10-01

4

Laboratory modeling of hypersonic flight conditions  

NASA Astrophysics Data System (ADS)

One of the key issues for vehicles in hypersonic flight and during atmospheric reentry is radio blackout due to weakly-ionized air plasma formation. When a spacecraft enters Earth's atmosphere or a vehicle travels through the atmosphere at hypersonic velocities, a shock wave is formed in front of the vehicle. The shock wave converts much of the vehicle's kinetic energy into heat and as a result the air molecules are dissociated and ionized. This plasma layer prevents normal telemetry transmission. This work considers a new approach to model the conditions of hypersonic flight in laboratory environment. The approach utilizes hypersonic plasma jet created by vacuum arc that hits immovable object intended to model a hypersonic vehicle. Heating of the object by the arc causes immediate re-evaporation of the jet's metal ions being deposited on the object's surface. This mimics absence of attachment of the air molecules to the vehicle in hypersonic flight. The plasma parameters and object temperatures are measured using electrostatic Langmuir probes and thermocouples respectively. The results of these experiments can be also used as calibration tool for tuning and debugging of numerical codes intended to predict and mitigate the blackout problem.

Shashurin, Alexey; Kundrapu, Madhusudhan; Loverich, John; Beilis, Isak; Keidar, Michael

2012-10-01

5

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

ERIC Educational Resources Information Center

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…

Brotherton, Sheila; And Others

6

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

PubMed

Chronological aging has been studied extensively in laboratory yeast by culturing cells into stationary phase in synthetic complete medium with 2% glucose as the carbon source. During this process, acidification of the culture medium occurs due to secretion of organic acids, including acetic acid, which limits survival of yeast cells. Dietary restriction or buffering the medium to pH 6 prevents acidification and increases chronological life span. Here we set out to determine whether these effects are specific to laboratory-derived yeast by testing the chronological aging properties of the vineyard yeast strain RM11. Similar to the laboratory strain BY4743 and its haploid derivatives, RM11 and its haploid derivatives displayed increased chronological life span from dietary restriction, buffering the pH of the culture medium, or aging in rich medium. RM11 and BY4743 also displayed generally similar aging and growth characteristics when cultured in a variety of different carbon sources. These data support the idea that mechanisms of chronological aging are similar in both the laboratory and vineyard strains. PMID:21949725

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

2011-01-01

7

29 CFR 1620.18 - Jobs performed under similar working conditions.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Jobs performed under similar working conditions...COMMISSION THE EQUAL PAY ACT § 1620.18 Jobs performed under similar working conditions...for the equal pay standard to apply, the jobs are required to be performed...

2013-07-01

8

Laboratory testing of dispersants under Arctic conditions  

Microsoft Academic Search

The effectiveness of relevant dispersants for use under Arctic conditions has been tested with the IFP dilution test. Arctic conditions in this context are defined as low temperature (0 C) and water salinities varying between 0.5% and 3.5%. The study was performed in three steps with a screening activity first, where 14 dispersants were tested on water-in-oil (w\\/o) emulsions from

P. J. Brandvik; O. O Knudsen; M. O. Moldestad; P. S. Daling

1995-01-01

9

Laboratory testing of dispersants under Arctic conditions  

SciTech Connect

The effectiveness of relevant dispersants for use under Arctic conditions has been tested with the IFP dilution test. Arctic conditions in this context are defined as low temperature (0 C) and water salinities varying between 0.5% and 3.5%. The study was performed in three steps with a screening activity first, where 14 dispersants were tested on water-in-oil (w/o) emulsions from two weathered oil types. In the next step five dispersants were tested on both weathered water free oils and w/o emulsions from four different oil types. As a third step, dispersant effectiveness as a function of salinity (0.5 to 3.5%) was tested with the most effective dispersants at high and low salinity. The results from this study shows that many of the most used dispersants which previously have shown an excellent effectiveness at high sea water salinity (3.5%) may give a very low effectiveness at low salinity (0.5%). Recently developed products especially designed for low salinity use (e.g. Inipol IPF) are very effective at low salinities, but suffer from a rather poor effectiveness at higher salinities. This is of significant operational importance in Arctic oil spill combat operations since the salinity of the surface water may vary due to ice melting. This study of dispersant`s effectiveness under Arctic conditions shows the need for development of dispersants with high effectiveness both at low temperature (0 C) and over a wide range of salinities (3.5% to 0.5%). Dispersant development has been a limited but important activity at IKU for the last five years and one of the objectives for an ongoing Arctic program at IKU is to develop such new dispersants for use under Arctic conditions.

Brandvik, P.J.; Knudsen, O.O; Moldestad, M.O.; Daling, P.S. [IKU Petroleum Research, Trondheim (Norway)

1995-06-01

10

Special Conditional Similarity Reduction Solutions for Two Nonlinear Partial Differential Equations  

NASA Astrophysics Data System (ADS)

We present a method of special conditional similarity reduction solutions for nonlinear partial differential equations. As concrete examples of its application, we apply this method to the (2+1)-dimensional modified Broer-Kaup equations and the variable coefficient KdV-mKdV equation, which have extensive physics backgrounds, and obtain abundant exact solutions derived from some reduction equations.

Ma, Zheng-Yi

2007-08-01

11

The effect of stimulus similarity on the acquisition and extinction of a conditioned response  

Microsoft Academic Search

This study was designed to investigate the effects of the similarity between a reinforced and a nonreinforced stimulus on the acquisition and extinction of a conditioned galvanic skin response (GSR). Five groups of 20 Ss each were given 10 reinforced acquisition trials consisting of a 1-sone, 1967-cps tone followed by a mild shock. Three of the groups were presented 10

Darwin P. Hunt

1962-01-01

12

Gender similarities and differences in sexual arousal, desire, and orgasmic pleasure in the laboratory.  

PubMed

Relatively little is known about gender differences in the orgasm experience. The objectives of this study were to compare men's and women's patterns of sexual arousal and desire before and after orgasm, and the predictors of their orgasmic pleasure. Using their typical technique, where masturbation enjoyment was similar to that experienced at home, 38 men and 38 women masturbated to orgasm in the laboratory. Physiological sexual arousal (genital temperature) and subjective sexual arousal and desire measurements were taken at baseline, after masturbation almost to orgasm, and immediately and 15 minutes after orgasm. In both genders, all measures increased significantly during masturbation, with a greater buildup leading to a more pleasurable orgasm. After orgasm, however, sexual arousal and desire decreased more quickly and consistently in men than in women, thereby replicating Masters and Johnson's ( 1966 ) observations. More men than women exhibited resolution of subjective sexual arousal and sexual satiation; their genital temperature also decreased more than women's but did not return to baseline. Women's orgasmic pleasure was related to a postorgasmic decrease in genital temperature but, unexpectedly, the maintenance of subjective sexual arousal and desire. Future studies should explore whether this pattern explains gender differences in the pursuit of additional orgasms. PMID:24588445

Paterson, Laurel Q P; Jin, Ellie Shuo; Amsel, Rhonda; Binik, Yitzchak M

2014-10-01

13

Anaerobic Biodegradation of Alkylbenzenes in Laboratory Microcosms Representing Ambient Conditions  

Microsoft Academic Search

A microcosm study was performed to document the anaerobic biodegradation of benzene, toluene, ethylbenzene, m- xylene, and\\/or o-xylene in petroleum-contaminated aquifer sediment from sites in Michigan (MI) and North Carolina (NC) and relate the results to previous field investigations of intrinsic bioremediation. Laboratory microcosms, designed to simulate ambient conditions, were constructed under anaerobic conditions with sediment and groundwater from source,

Melody J. Hunt; Michael B. Shafer; Morton A. Barlaz; Robert C. Borden

1997-01-01

14

Similarities of dielectric surface flashover under atmospheric conditions for pulsed unipolar and RF excitation  

Microsoft Academic Search

Mechanisms in vacuum surface flashover caused by rf (f < 10 GHz) or unipolar voltages are virtually identical. Similarities between rf (representing high-power microwave window\\u000a breakdown on the high-pressure side) and unipolar surface flashover are expected in an atmospheric environment as well. Two\\u000a separate experimental setups were utilized to investigate both unipolar flashover and rf window flashover under atmospheric\\u000a conditions

J. Krile; G. Edmiston; K. Morales; A. Neuber; H. Krompholz; M. Kristiansen

2006-01-01

15

Extension of laboratory-measured soil spectra to field conditions  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

16

Hydrological conditions at the 800 Area at Argonne National Laboratory  

Microsoft Academic Search

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

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

1990-01-01

17

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...

18

Reproductive traits of Monochamus galloprovincialis (Coleoptera: Cerambycidae) under laboratory conditions.  

PubMed

The pine sawyer Monochamus galloprovincialis (Olivier) is the vector of the introduced pine wood nematode Bursaphelenchus xylophilus (Steiner & Bührer) Nickle in Portugal, and until recently was considered a secondary forest insect. Under laboratory conditions, a study of biological and reproductive traits of 37 insect pairs was conducted. The longevity of both sexes was similar, being 61.2+/-6.5 days for males and 64.0+/-6.3 days for females (mean+/-SE). Sixteen small-sized insects (22% of the population) died within 20 days and before starting to reproduce. The sexual maturation period (without egg laying) was 20.4+/-0.7 days (mean+/-SE), while the oviposition period lasted 54.0+/-4.2 days (mean+/-SE). The oviposition rate increased very quickly during the first weeks of life, peaking to almost two eggs per day during days 30-44, and gradually dropping in the following weeks. The females laid an average of 67.0+/-5.96 (mean+/-SE) eggs through their lives. The hatch rate was 92.6+/-1.0% (mean+/-SE). There were large individual variations in longevity and fecundity parameters, and principal component analysis based on 16 morphological and biological parameters separated the breeding insects into four distinct groups. Almost half of the reproducing beetles were large-sized insects, with high longevity and fecundity traits. Overall, the reproductive potential of the Portuguese population of M. galloprovincialis seems to be smaller than that described for other Monochamus vectors of the pine wood nematode both in North America and Japan. PMID:16768817

Naves, P; de Sousa, E; Quartau, J A

2006-06-01

19

Reproducing stone monument photosynthetic-based colonization under laboratory conditions.  

PubMed

In order to understand the biodeterioration process occurring on stone monuments, we analyzed the microbial communities involved in these processes and studied their ability to colonize stones under controlled laboratory experiments. In this study, a natural green biofilm from a limestone monument was cultivated, inoculated on stone probes of the same lithotype and incubated in a laboratory chamber. This incubation system, which exposes stone samples to intermittently sprinkling water, allowed the development of photosynthetic biofilms similar to those occurring on stone monuments. Denaturing gradient gel electrophoresis (DGGE) analysis was used to evaluate the major microbial components of the laboratory biofilms. Cyanobacteria, green microalgae, bacteria and fungi were identified by DNA-based molecular analysis targeting the 16S and 18S ribosomal RNA genes. The natural green biofilm was mainly composed by the Chlorophyta Chlorella, Stichococcus, and Trebouxia, and by Cyanobacteria belonging to the genera Leptolyngbya and Pleurocapsa. A number of bacteria belonging to Alphaproteobacteria, Bacteroidetes and Verrucomicrobia were identified, as well as fungi from the Ascomycota. The laboratory colonization experiment on stone probes showed a colonization pattern similar to that occurring on stone monuments. The methodology described in this paper allowed to reproduce a colonization equivalent to the natural biodeteriorating process. PMID:18768211

Miller, Ana Zélia; Laiz, Leonila; Gonzalez, Juan Miguel; Dionísio, Amélia; Macedo, Maria Filomena; Saiz-Jimenez, Cesareo

2008-11-01

20

Human Gait Recognition And Classification Using Similarity Index for various conditions  

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

21

Seal formation in arid soil under natural and laboratory conditions  

NASA Astrophysics Data System (ADS)

Runoff is of considerable importance in the functioning of a desert ecosystem. The hydrological characteristics of runoff developing on arid soil under natural field conditions and those of runoff occurring in laboratory-controlled rain simulation experiments using the same type of soil were investigated. Runoff and erosion measurements were carried out in small plots (0.2-0.8 m2) on a south-facing hillslope in the northern Negev, Israel (90 mm ave. annual rainfall). Soil from the area near to the runoff plots was collected for the rain simulation experiments conducted in the laboratory. The soil was collected from 0-1 cm and 1-5 cm depths, and then placed within boxes (1.16 m long and 0.55 m wide) in the laboratory in the same order as they had been in the field. Representative surface stones were collected in the field and scattered randomly on the soil surface in the laboratory boxes. In some of the laboratory experiments soil, 5 cm in depth, was placed on a geotechnical sheet on a metal screen, while in other experiments, soil of 5 cm depth was placed on a Terzaghi filter. Rain simulator used had a rotating disk with a tilted nozzle to simulate raindrop size dispersion and kinetic energy of natural rain. The sprinkling intensity was set at a rate of 18 mm/hour. Soil crusts in the field were more stable than those created in the lab for two standard tests: Emerson - immersion test, and the 'single water drop' test. Whereas weak activity of microphytes was found in the field there was no such activity in the lab. The rain depth until runoff in the field was less than under laboratory conditions, while the sediment yield was greater in the field than in the laboratory (8.64 g/m2 versus 0.58 g/m2). The rain simulator experiments that had included a Terzaghi filter showed significantly higher final infiltration rate (7.5 mm/h versus 4.2 mm/h), shorter accumulated watering depth until stabilization of soil seal formation (100-200 mm versus 50 mm), and smaller fraction of clay in the crust (4.2% versus 6.8%), than the experiments that done without this filter. Therefore, it is conceivable that there is a suction of thin material from the surface while capillary pressures are activated, result in sub-surface seal formation (washed-in layer). This can lead to differences between runoff-forming processes existing in the laboratory set-up and processes that occur under natural field conditions.

Sarah, Pariente; Sachs, Eyal

2013-04-01

22

Observational evidence for the Monin-Obukhov similarity under all stability conditions  

NASA Astrophysics Data System (ADS)

Data collected in the surface layer in a northern suburban area of Nanjing from 15 November to 29 December 2007 were analyzed to examine the Monin-Obukhov similarity for describing the turbulent fluctuations of 3D winds under all stability conditions and to obtain the turbulence characteristics under different weather conditions. The results show that the dimensionless standard deviations of turbulent velocity components ( ? u / u*, ? ? / u*, ? w / u*) and dimensionless turbulent kinetic energy (TKE) can be well described by "1/3" power law relationships under stable, neutral, and unstable conditions, with ? u / u* > ? ? / u* > ? w / u*. Land use and land cover changes mainly impact dimensionless standard deviations of horizontal component fluctuations, but they have very little on those of the vertical component. The dimensionless standard deviations of wind components and dimensionless TKE are remarkably affected by different weather conditions; the deviations of horizontal wind component and dimensionless TKE present fog day > clear sky > overcast > cloudy; the trend of the vertical wind component is the reverse. The surface drag coefficient at a Nanjing suburban measurement site during the observation period was obviously higher than at other reported plains and plateau areas, and was approximately one order larger in magnitude than the reported plains areas. Dimensionless standard deviation of temperature declined with increasing |z'/ L| with an approximate "-1/3" slope in unstable stratification and "-2/3" slope in stable stratification.

Niu, Shengjie; Zhao, Lijuan; Lu, Chunsong; Yang, Jun; Wang, Jing; Wang, Weiwei

2012-03-01

23

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

PubMed

We have examined the potential to generate bona fide macrophages (MØ) from conditionally immortalised murine bone marrow precursors. MØ can be derived from Hoxb8 conditionally immortalised macrophage precursor cell lines (MØP) using either M-CSF or GM-CSF. When differentiated in GM-CSF (GM-MØP) the resultant cells resemble GM-CSF bone marrow-derived dendritic cells (BMDC) in morphological phenotype, antigen phenotype and functional responses to microbial stimuli. In spite of this high similarity between the two cell types and the ability of GM-MØP to effectively present antigen to a T-cell hybridoma, these cells are comparatively poor at priming the expansion of IFN-? responses from naïve CD4(+) T cells. The generation of MØP from transgenic or genetically aberrant mice provides an excellent opportunity to study the inflammatory role of GM-MØP, and reduces the need for mouse colonies in many studies. Hence differentiation of conditionally immortalised MØPs in GM-CSF represents a unique in vitro model of inflammatory monocyte-like cells, with important differences from bone marrow-derived dendritic cells, which will facilitate functional studies relating to the many 'sub-phenotypes' of inflammatory monocytes. PMID:21268006

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

2011-02-01

24

Comparisons of some NIST fixed-point cells with similar cells of other standards laboratories  

Microsoft Academic Search

In this paper we present results of international comparisons of fixed-point cells of some of the defining fixed-point materials of the International Temperature Scale of 1990. These comparisons involved cells from seven national laboratories, although in some cases only one type of fixed-point material was compared. Except for silver cells, the agreement among cells of the same defining fixed-point material

B. W. Mangum; E. R. Pfeiffer; G. F. Strouse; J. Valencia-Rodriguez; J. H. Lin; T. I. Yeh; P. Marcarino; R. Dematteis; Y. Liu; Q. Zhao; A. T. Ince; F. Çakiroglu; H. G. Nubbemeyer; H.-J. Jung

1996-01-01

25

Red sprite discharges in the atmosphere at high altitude: the molecular physics and the similarity with laboratory discharges  

Microsoft Academic Search

An overview of the general phenomenology and physical mechanism of large-scale electrical discharges termed ‘sprites’ observed at high altitude in the Earth's atmosphere above thunderstorms is presented. The primary emphasis is placed on summarizing available experimental data on various emissions documented to date from sprites and interpretation of these emissions in the context of similar data obtained from laboratory discharges,

V P Pasko

2007-01-01

26

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)

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 ?g m-3, with a project mean and standard deviation of 1.3±1.0 ?g m-3 and 0.21±0.16 ?g 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, which were analyzed by scanning transmission X-ray microscopy near edge X-ray absorption fine structure (STXM-NEXAFS).

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

27

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)

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 3.1?g m-3, with a project mean and standard deviation of 1.3±1.0 ?g m-3 and 0.21±0.16 ?g 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 by scanning transmission X-ray microscopy near edge X-ray absorption fine structure (STXM-NEXAFS).

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

28

Laboratory simulations of NAT formation approaching stratospheric conditions  

NASA Technical Reports Server (NTRS)

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

Marti, James; Mauersberger, Konrad

1994-01-01

29

Laboratory simulations of NAT formation approaching stratospheric conditions  

NASA Astrophysics Data System (ADS)

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

Marti, James; Mauersberger, Konrad

1994-04-01

30

Microbial surfactant-enhanced mineral oil recovery under laboratory conditions.  

PubMed

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

Bordoloi, N K; Konwar, B K

2008-05-01

31

Evaluation of annoyance from low frequency noise under laboratory conditions.  

PubMed

The aim of the study was to investigate the annoyance of low frequency noise (LFN) at levels normally prevailing at workplaces in control rooms and office-like areas. Two different laboratory experiments were carried out. The first experiment included 55 young volunteers and the second one comprised 70 older volunteers, categorized in terms of sensitivity to noise. The subjects listened to noise samples with different spectra, including LFNs at sound pressure level (SPL) of 45-67 dBA, and evaluated annoyance using a 100-score graphical rating scale. The subjective ratings of annoyance were compared to different noise metrics. In both the experiments, there were no differences in annoyance assessments between females and males. A significant influence of individual sensitivity to noise on annoyance rating was observed for some LFNs. Annoyance of LFN was not rated higher than annoyance from broadband noises without or with less prominent low frequencies at similar A-weighted SPLs. In both the experiments, median annoyance rating of LFN highly correlated with A-weighted SPL (L(Aeq,T)), low frequency A-weighted SPL (L(LFAeq,T)) and C-weighted SPL (L(Ceq,T)). However, it is only the two latter noise metrics (i.e. L(LFAeq,T) and L(Ceq,T)) which seem to be reliable predictors of annoyance exclusively from LFN. The young and older participants assessed similar annoyance from LFN at similar L(LFAeq,T) or L(Ceq,T) levels. Generally, over half of the subjects were predicted to be highly annoyed by LFN at the low frequency A-weighted SPL or C-weighted SPL above 62 and 83 dB, respectively. PMID:20603573

Pawlaczyk-Luszczynska, Malgorzata; Dudarewicz, Adam; Szymczak, Wieslaw; Sliwinska-Kowalska, Mariola

2010-01-01

32

Performance Evaluation of a Continuous Glucose Monitoring System under Conditions Similar to Daily Life  

PubMed Central

Background This study aimed at evaluating and comparing the performance of a new generation of continuous glucose monitoring (CGM) system versus other CGM systems, under daily lifelike conditions. Methods A total of 10 subjects (7 female) were enrolled in this study. Each subject wore two Dexcom G4™ CGM systems in parallel for the sensor lifetime specified by the manufacturer (7 days) to allow assessment of sensor-to-sensor precision. Capillary blood glucose (BG) measurements were performed at least once per hour during daytime and once at night. Glucose excursions were induced on two occasions. Performance was assessed by calculating the mean absolute relative difference (MARD) between CGM readings and paired capillary BG readings and precision absolute relative difference (PARD), i.e., differences between paired CGM readings. Results Overall aggregate MARD was 11.0% (n = 2392). Aggregate MARD for BG <70 mg/dl was 13.7%; for BG between 70 and 180 mg/dl, MARD was 11.4%; and for BG >180 mg/dl, MARD was 8.5%. Aggregate PARD was 7.3%, improving from 11.6% on day 1 to 5.2% on day 7. Conclusions The Dexcom G4 CGM system showed good overall MARD compared with results reported for other commercially available CGM systems. In the hypoglycemic range, where CGM performance is often reported to be low, the Dexcom G4 CGM system achieved better MARD than that reported for other CGM systems in the hypoglycemic range. In the hyperglycemic range, the MARD was comparable to that reported for other CGM systems, whereas during induced glucose excursions, the MARD was similar or slightly worse than that reported for other CGM systems. Overall PARD was 7.3%, improving markedly with sensor life time.

Pleus, Stefan; Schmid, Christina; Link, Manuela; Zschornack, Eva; Klotzer, Hans-Martin; Haug, Cornelia; Freckmann, Guido

2013-01-01

33

Life cycle of tortoise tick Hyalomma aegyptium under laboratory conditions.  

PubMed

The tortoise tick Hyalomma aegyptium has a typical three-host life-cycle. Whereas its larvae and nymphs are less host-specific feeding on a variety of tetrapods, tortoises of the genus Testudo are principal hosts of adults. Ticks retained this trait also in our study under laboratory conditions, while adults were reluctant to feed on mammalian hosts. Combination of feeding larvae and nymphs on guinea pigs and feeding of adults on Testudo marginata tortoises provided the best results. Feeding period of females was on average 25 days (range 17-44), whereas males remain after female engorgement on tortoise host. Female pre-oviposition period was 14 days (3-31), followed by 24 days of oviposition (18-29). Pre-eclosion and eclosion, both together, takes 31 days (21-43). Larvae fed 5 days (3-9), then molted to nymphs after 17 days (12-23). Feeding period of nymphs lasted 7 days (5-10), engorged nymphs molted to adults after 24 days (19-26). Sex ratio of laboratory hatched H. aegyptium was nearly equal (1:1.09). The average weight of engorged female was 0.95 (0.72-1.12) g. The average number of laid eggs was 6,900 (6,524-7,532) per female, it was significantly correlated with weight of engorged female. Only 2.8% of engorged larvae and 1.8% of engorged nymphs remained un-molted and died. Despite the use of natural host species, feeding success of females reached only 45%. The whole life-cycle was completed within 147 days (98-215). PMID:21431927

Siroký, Pavel; Erhart, Jan; Petrželková, Klára J; Kamler, Martin

2011-07-01

34

42 CFR 494.130 - Condition: Laboratory services.  

Code of Federal Regulations, 2013 CFR

...or make available, laboratory services (other than tissue pathology and histocompatibility) to meet the needs of the ESRD patient. Any laboratory services, including tissue pathology and histocompatibility must be furnished by or obtained...

2013-10-01

35

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)

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 300 to 305 a.m. on the 23th day we recorded 27 contacts of aggressive character between the individuals. So, in hypomagnetic field conditions the irritability of the animals' central nervous system grows, that expresses itself in the increase of contacts of aggressive and non-aggressive character between the individuals. Also we have carried out the Spirman correlation analysis between studied indices of moving activity and chemiluminescence of blood plasma and urine, electrolytic composition of urine and muscles. For control animals the quantity of correlation connections between electrolyte concentrations in studied substrata was higher than for experimental animals. The physiological sense of these correlation connections is discussed.

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

36

Capillary trapping under mixed-wet conditions: laboratory observations  

NASA Astrophysics Data System (ADS)

As a wetting phase displaces a non-wetting phase in a porous medium, a portion of the latter becomes immobilized by capillary forces as discontinuous pore-scale ganglia. This phenomenon, known as capillary trapping, hinders the extraction of non-aqueous contaminants from groundwater and oil from geological reservoirs. Here, we consider the impact of wettability on capillary trapping. In uniformly water-wet media, it is well established that residual non-wetting phase saturation increases monotonically with its initial saturation. In contrast, little is understood about mixed-wet media, in which parts of the pore surface are oil-wet while the rest is water-wet. We present laboratory measurements of residual oil saturation in a limestone in its original, water-wet state and under mixed-wet conditions established systematically using organic acid. The data show that, in contrast to water-wet systems, waterflood residual in mixed-wet systems exhibits three distinct regimes as initial saturation is increased. In particular, there is an intermediate regime in which residual saturation decreases as initial saturation increases. 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.

Tanino, Y.; Blunt, M. J.

2012-12-01

37

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

PubMed Central

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.

Martinez-Ibarra, Jose Alejandro; Nogueda-Torres, Benjamin; Licon-Trillo, Angel; Villagran-Herrera, Maria Elena; de Diego-Cabrera, Jose Antonio; Montanez-Valdez, Oziel Dante; Rocha-Chavez, Gonzalo

2013-01-01

38

Similarity conditions for comparing closed-loop vehicle roll and pitch dynamics  

Microsoft Academic Search

Previous work has demonstrated that dynamic matching and similitude between controllers can be achieved for planar dynamic motion by careful construction of the test vehicle and testing under conditions that match selected parameters. Central to this analysis was the use of the Buckingham Pi theorem as applied to the planar vehicle dynamics. Increasingly, scale vehicle testbeds are being used to

Sean Brennan

2004-01-01

39

Hydrological conditions at the 800 Area at Argonne National Laboratory  

SciTech Connect

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.

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

1990-08-01

40

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 ...

41

REtools: A laboratory program for restriction enzyme work: enzyme selection and reaction condition assistance  

PubMed Central

Background Restriction enzymes are one of the everyday tools used in molecular biology. The continuously expanding panel of known restriction enzymes (several thousands) renders their optimal use virtually impossible without computerized assistance. Several manufacturers propose on-line sites that assist scientists in their restriction enzyme work, however, none of these sites meet all the actual needs of laboratory workers, and they do not take into account the enzymes actually present in one's own laboratory. Results Using FileMaker Pro, we developed a stand-alone application which can run on both PCs and Macintoshes. We called it REtools, for Restriction Enzyme tools. This program, which references all currently known enzymes (>3500), permits the creation and update of a personalized list of restriction enzymes actually available in one's own laboratory. Upon opening the program, scientists will be presented with a user friendly interface that will direct them to different menus, each one corresponding to different situations that restriction enzyme users commonly encounter. We particularly emphasized the ease of use to make REtools a solution that laboratory members would actually want to use. Conclusion REtools, a user friendly and easily customized program to organize any laboratory enzyme stock, brings a software solution that will make restriction enzyme use and reaction condition determination straightforward and efficient. The usually unexplored potential of isoschizomers also becomes accessible to all, since REtools proposes all possible enzymes similar to the one(s) chosen by the user. Finally, many of the commonly overlooked subtleties of restriction enzyme work, such as methylation requirement, unusual reaction conditions, or the number of flanking bases required for cleavage, are automatically provided by REtools.

Martin, Patrick; Boulukos, Kim E; Pognonec, Philippe

2006-01-01

42

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

Code of Federal Regulations, 2010 CFR

...complexity testing; technical supervisor. 493.1447 Section 493.1447 Public Health CENTERS FOR MEDICARE & MEDICAID...Laboratories Performing High Complexity Testing § 493.1447 Condition: Laboratories performing high...

2010-10-01

43

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

Code of Federal Regulations, 2013 CFR

... § 493.1481 Condition: Laboratories performing high complexity testing; cytotechnologist. For the subspecialty of cytology, the laboratory must have a sufficient number of cytotechnologists who meet the qualifications specified in § 493.1483 to...

2013-10-01

44

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

PubMed Central

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

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

2008-01-01

45

Exploring the nature of collisionless shocks under laboratory conditions  

PubMed Central

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.

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

2014-01-01

46

[Microbial growth on bitumen and chlorcaoutchouc under laboratory conditions (author's transl)].  

PubMed

Formerly published examinations of coating materials for drinking water reservoirs under working conditions were extended to those under laboratory standard. The tests of bitumen, chlorcaoutchouc, asbestos cement and polyacryl delivered results comparable to those achieved under working conditions. PMID:735574

Schoenen, D; Dott, W

1978-11-01

47

A laboratory acoustic emission experiment under in situ conditions  

NASA Astrophysics Data System (ADS)

In this paper, we revisit acoustic emission (AE) data from an in situ rock fracture experiment conducted at the Underground Research Laboratory (URL) in Manitoba, Canada. The Mine-By experiment, a large-scale excavation response test, was undertaken at a depth of 420 m and involved the mechanical excavation of a cylindrical tunnel. During the experiment a small array of 16 Panametrics V103 AE sensors enclosed a 0.7 m × 0.7 m × 1.1 m rectangular prism of Lac du Bonnet granite located in the tunnel wall. The V103 sensors were later calibrated in the laboratory, and a source parameter analysis was undertaken using a spectral fitting method. Corner frequency and moment magnitude were found to be inside the ranges 250 kHz

Goodfellow, S. D.; Young, R. P.

2014-05-01

48

Activity rhythms and masking response in the diurnal fat sand rat under laboratory conditions.  

PubMed

Daily rhythms are heavily influenced by light in two major ways. One is through photic entrainment of a circadian clock, and the other is through a more direct process, referred to as masking. Whereas entraining effects of photic stimuli are quite similar in nocturnal and diurnal species, masking is very different. Laboratory conditions differ greatly from what is experienced by individuals in their natural habitat, and several studies have shown that activity patterns can greatly differ between laboratory environment and natural condition. This is especially prevalent in diurnal rodents. We studied the daily rhythms and masking response in the fat sand rat (Psammomys obesus), a diurnal desert rodent, and activity rhythms of Tristram's jird (Meriones tristrami), a nocturnal member of the same subfamily (Gerbillinae). We found that most sand rats kept on a 12?h:12?h light-dark (LD) cycles at two light intensities (500 and 1000?lux) have a nocturnal phase preferences of general activity and higher body temperature during the dark phase. In most individuals, activity was not as stable that of the nocturnal Tritram's jirds, which showed a clear and stable nocturnal activity pattern under the same conditions. Sand rats responded to a 6-h phase advance and 6-h phase delay as expected, and, under constant conditions, all tested animals free ran. In contrast with the nocturnal phase preference, fat sand rats did not show a masking response to light pulses during the dark phase or to a dark pulse during the light phase. They did, however, have a significant preference to the light phase under a 3.5?h:3.5?h LD schedule. Currently, we could not identify the underlying mechanisms responsible for the temporal niche switch in this species. However, our results provide us with a valuable tool for further studies of the circadian system of diurnal species, and will hopefully lead us to understanding diurnality, its mechanisms, causes, and consequences. PMID:23926956

Barak, Orly; Kronfeld-Schor, Noga

2013-11-01

49

Performance of various similarity functions for nondimensional wind and temperature profiles in the surface layer in stable conditions  

NASA Astrophysics Data System (ADS)

The linear functions for non-dimensional wind and temperature profiles are commonly used to describe the surface layer fluxes in atmospheric models. However, their applicability is limited to smaller values of the stability parameter z/ L (where z is the height above ground and L is the Obukhov length) i.e. z/ L < 1.0. These linear functions have been modified (Webb 1970, Quart. J. Roy. Meteor. Soc. 96, 67-90; Clarke 1970, Quart. J. Roy. Meteor. Soc. 96, 91-114; Hicks 1976, Quart. J. Roy. Meteor. Soc. 102, 535-551; Beljaars and Holtslag 1991, J. Appl. Meteorol. 30, 327-341; Cheng and Brutsaert 2005, Boundary-Layer Meteorol. 114, 519-538) over the years for calculating fluxes when z/ L > 1.0 under strongly stable conditions. In view of this, the objective of the present study is to analyze the performance of these similarity functions to compute surface fluxes in stable conditions. The meteorological observations from the Cooperative Atmosphere-Surface Exchange Study (CASES-99) experiment are utilized for computing the surface fluxes in stable conditions. The computed fluxes are found to be reasonably close to those observed. The ratio of observed to computed fluxes reveals that the computed fluxes are close to the observations for all the similarity functions for z/ L < 1.0 whereas the computed values show relatively a large scatter from observations for z/ L > 1.0. The computed values of u* and heat flux do not show significant differences from those observed at 99% confidence limit. The performance of all the similarity functions considered here is found to be comparable to each other in strongly stable conditions.

Sharan, Maithili; Aditi

2009-10-01

50

Impact of hairy vetch cover crop on herbicide transport under field and laboratory conditions.  

PubMed

This study was conducted to evaluate the effect of hairy vetch cover crop residue on runoff losses of atrazine and metolachlor under both no-till corn field plots and from a laboratory runoff system. A 2-year field study was conducted in which losses of atrazine and metolachlor from vetch and non-vetch field plots were determined from the first runoff event after application (5 and 25 days after application in 1997 and 1998, respectively). A laboratory study was conducted using soil chambers, designed to simulate field soil, water, vegetation, and herbicide treatment conditions, subjected to simulated rain events of 5, 6, 20 and 21 days after application, similar to the rainfall pattern observed in the field study. Atrazine losses ranged from 1.2 to 7.2% and 0.01 to 0.08% and metolachlor losses ranged from 0.7 to 3.1% and 0.01 to 0.1% of the amount applied for the 1997 and 1998 runoff events, respectively. In the laboratory study, atrazine runoff losses ranged from 6.7 to 22.7% and 4.2 to 8.5% and metolachlor losses ranged from 3.6 to 9.8% and 1.1 to 4.7% of the amount applied for the 5-6 and 20-21 day events, respectively. The lower losses from the field study were due to smaller rainfall amounts and a series of small rains prior to the runoff event that likely washed herbicides off crop residue and into soil where adsorption could occur. Runoff losses of both herbicides were slightly higher from non-vetch than vetch field plots. Losses from the laboratory study were related to runoff volume rather than vegetation type. PMID:11444292

Sadeghi, A M; Isensee, A R

2001-07-01

51

Carbofuran promotes biochemical changes in carp exposed to rice field and laboratory conditions.  

PubMed

Effects of carbofuran commercial formulation on oxidative stress parameters were studied in carps (Cyprinus carpio) exposed to 50µg/L for 7 and 30 days under rice field and laboratory conditions. Thiobarbituric acid reactive substance (TBARS) levels were increased in the brain of fish after 7 and 30 days under rice field and laboratory conditions. In the liver and muscle, TBARS levels increased after 7 and 30 days under laboratory conditions, whereas in rice field the levels increased only after 30 days. Protein carbonyl content in the liver increased after 7 and 30 days under both experimental conditions. Acetylcholinesterase (AChE) activity was decreased in the brain and muscle after 7 and 30 days under both experimental conditions evaluated. The superoxide dismutase (SOD) activity increased in the liver after 7 and 30 days under rice field condition, whereas under laboratory condition this enzyme increased only after 30 days. The catalase (CAT) activity in the liver decreased after 30 days under rice field condition, whereas no changes were observed under laboratory conditions. In rice field, glutathione S-transferase (GST) decreased after 7 days but increased after 30 days, whereas no change was observed in fish exposed to carbofuran under laboratory conditions. These results suggest that environmental relevant carbofuran concentrations may cause oxidative stress, affecting biochemical and enzymatic parameters on carps. Some parameters could be used as biomarkers to carbofuran exposure. PMID:24507130

Clasen, Bárbara; Leitemperger, Jossiele; Murussi, Camila; Pretto, Alexandra; Menezes, Charlene; Dalabona, Fabrícia; Marchezan, Enio; Adaime, Martha Bohrer; Zanella, Renato; Loro, Vania Lucia

2014-03-01

52

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

NASA Astrophysics Data System (ADS)

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

Lanta, Vojt?ch; Doležal, Ji?í; Zemková, Lenka; Lepš, Jan

2012-06-01

53

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

PubMed

SUMMARY The following parameters were varied: 1) irradiation technique: top and bottom polymerization according to the ISO standard, and polymerization from only the top, simulating clinical situations; 2) polymerization time: 5, 10, 20, and 40 seconds; 3) storage conditions: 24 hours in distilled water, thermocycling followed by storage for four weeks in artificial saliva or alcohol. Flexural strength (FS), flexural modulus (Eflexural), indentation modulus (E), Vickers hardness (HV), and degree of conversion (DC) were measured. The laboratory results were similar to those measured by mimicking clinical conditions only at high polymerization times and mild storage conditions (20 seconds and 40 seconds and storage for 24 hours in water, and 40 seconds with aging and storing in saliva). Significantly higher DC values were measured on the top than on the bottom of a 2-mm layer for all polymerization times. Overall, 5-second and 10-second irradiation times induced significantly lower DC values compared to the currently recommended polymerization times of 20 and 40 seconds at both the top and bottom of the samples. The initial DC differences as a function of irradiation time are leveled at 24 hours of storage but seem to do well in predicting long-term material behavior. A minimum irradiation time of 20 seconds is necessary clinically to achieve the best mechanical properties with modern high-intensity light emitting diode (LED) units. PMID:22788727

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

2013-01-01

54

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

NASA Astrophysics Data System (ADS)

It is well known that the infrared emission of many comets is characterized by a broad feature at 10 micrometers, that has been attributed to a Si-O stretching resonance in amorphous and/or hydrated silicate grains. In the case of comets Halley [1,2], Bradfield [3] and Levy [4] two spectral components have been observed: the wide peak centered at 9.8 micrometers and a sharp feature at 11.3 micrometers. This last band has been interpreted with crystalline olivine silicatic grains [1,2,5]. However, recently, it has been pointed out [6] that the laboratory data frequently used in the fits refer to grains embedded in a matrix, which should produce a significant shift of the peak position, according to Mie computations. We have performed laboratory experiments on various silicatic samples with the perspective of determining their optical properties, to study experimentally the influence of matrix effects, and to use the final spectra to perform comparisons with observations. The samples are four terrestrial materials, olivine forsterite, jadeite pyroxene, andesite feldspar and impactite glass, and two meteoritic samples, chondrite (Zacatecas, Mexico) and pallasite (Atacama, Chile). Fine powders of the bulk materials were obtained by grinding calibrated mass amounts of the various samples in an agata mill. The morphological characterization of the samples was performed by means of S.E.M. (scanning electron microscopy) technique. EDX analysis was also performed to determine elemental composition. IR transmission spectra were obtained by using a double beam spectrophotometer that covers the spectral range 2.5-50 micrometers. The standard pellet technique was used by embedding dust samples in KBr or CsI matrices. For comparison, measurements were also performed by depositing small amounts of dust onto KBr windows. In this last case, dust-matrix interaction should be practically absent as grains are simply sitting onto the matrix. The data obtained from the spectroscopic 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 al. (1990) 22nd annual meeting of the division for planetary sciences, Charlottesville, Virgin

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

1993-07-01

55

Studies on the survival of Ascaris suum eggs under laboratory and simulated field conditions  

Microsoft Academic Search

A series of four experiments was carried out to study the survival of Ascaris suum eggs: in a pig slurry unit on a farm, in the laboratory under anaerobic conditions and different relative humidities (rH), and under simulated field conditions. Survival of eggs in the pig slurry unit was 20% after four weeks and 0% after 16 weeks. Anaerobic conditions

C. P. H. Gaasenbeek; F. H. M. Borgsteede

1998-01-01

56

Determination of cleanability and wearing of plastic flooring surfaces in field and laboratory conditions  

Microsoft Academic Search

Plastic surfaces are used widely as flooring materials in public and residential buildings. When new floor coverings are developed, both field and laboratory tests are needed. In this study the tendency to soiling and wearing and the cleanability of six commercial plastic flooring surfaces were examined in both field and laboratory conditions. The plastic flooring surfaces were studied using colorimetry

R. Kuisma; H.-R. Kymäläinen; A.-M. Sjöberg

2009-01-01

57

SOLERAS - Saudi University Solar Cooling Laboratories Project: University of Riyadh. Solar air conditioning. Final report  

SciTech Connect

Research on solar air conditioning at the University of Riyadh in Riyhadh, Saudi Arabia is presented. Topics relevant to the university's proposed solar cooling laboratory are discussed: absorption systems and various contingencies, photovoltaic solar collectors and thermoelectric elements, measuring instruments, solar radiation measurement and analysis, laboratory specifications, and decision theories. Dual cycle computations and equipment specifications are included among the appendices.

Not Available

1986-01-01

58

Free-sporing Cl. welchii in ordinary laboratory media and conditions.  

PubMed

A strain of Clostridium welchii produced spores in ordinary blood agar plates. Investigations confirmed that it was the character of this particular strain and that the laboratory media were not inducing sporulation. During a period of 12 months a total of 100 strains of Cl. welchii were studied. None of them produced spores in ordinary laboratory media and conditions when examined microscopically. PMID:205556

Rahman, M

1978-04-01

59

Activity and Feeding Behavior of the Summer Flounder 'Paralichthys dentatus' Under Controlled Laboratory Conditions.  

National Technical Information Service (NTIS)

A group of five to six adult summer flounder, Paralichthys dentatus (Linnaeus), held under controlled laboratory conditions in a large, experimental, seawater tank, exhibited three general behavior patterns: (1) resting, (2) swimming, and (3) feeding. Whi...

B. L. Olla C. E. Samet A. L. Studholme

1972-01-01

60

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

NASA Astrophysics Data System (ADS)

Satellite remote sensing is one of the main techniques of monitoring severe weather conditions over the ocean. The principal difficulty of the existing algorithms of retrieving wind based on dependence of microwave backscattering cross-section on wind speed (Geophysical Model Function, GMF) is due to its saturation at winds exceeding 25 - 30 m/s. Recently analysis of dual- and quad-polarization C-band radar return measured from satellite Radarsat-2 suggested that the cross-polarized radar return has much higher sensitivity to the wind speed than co-polarized back scattering [1] and conserved sensitivity to wind speed at hurricane conditions [2]. Since complete collocation of these data was not possible and time difference in flight legs and SAR images acquisition was up to 3 hours, these two sets of data were compared in [2] only statistically. The main purpose of this paper is investigation of the functional dependence of cross-polarized radar cross-section on the wind speed in laboratory experiment. Since cross-polarized radar return is formed due to scattering at small-scale structures of the air-sea interface (short-crested waves, foam, sprays, etc), which are well reproduced in laboratory conditions, then the approach based on laboratory experiment on radar scattering of microwaves at the water surface under hurricane wind looks feasible. The experiments were performed in the Wind-wave flume located on top of the Large Thermostratified Tank of the Institute of Applied Physics, where the airflow was produced in the flume with the straight working part of 10 m and operating cross section 0.40?0.40 sq. m, the axis velocity can be varied from 5 to 25 m/s. Microwave measurements were carried out by a coherent Doppler X-band (3.2 cm) scatterometer with the consequent receive of linear polarizations. Experiments confirmed higher sensitivity to the wind speed of the cross-polarized radar return. Simultaneously parameters of the air flow in the turbulent boundary layer (friction velocity and roughness height) were retrieved by velocity profiling and subsequent data processing based on self-similarity of the turbulent boundary layer and 10-m wind speed was calculated. The wind wave field parameters in the flume were measured by three wire gauges. The measured data on wind waves were used for estimation of the short wave spectra and slope probability density function for "long waves" within composite Bragg theory of microwave radar return. Estimations showed that for co-polarized radar returns the difference between measurements and the predictions of the model is about 1-2 dB and it can be explained by our poor knowledge about the short wave part of the spectrum. For cross-polarized return the difference exceeds 10 dB, and it indicates that some non-Bragg mechanisms (short-crested waves, foam, sprays, etc) are responsible for the depolarization of the returned signal. It seems reasonable then to suppose that the cross-polarized radar return in X- and C-bands will demonstrate similar dependence on wind speed. We compared the dependence of cross-polarized X-band radar cross-section on 10-m wind speed obtained in laboratory conditions with the similar dependence obtained in [2] from the field data for C-band radar cross-section and found out that the laboratory data follow the median of the field data with the constant bias -11 dB. Basing on laboratory data an empirical polynomial geophysical model function was suggested for retrieving wind speed up to 40 m/s from cross-polarized microwave return, which is in good agreement with the direct measurements. This work was carried out under financial support of the RFBR (project codes ¹ 13-05-00865, 12-05-12093) and by grant from the Government of the Russian Federation (project code 11.G34.31.0048). References [1] B. Zhang, W. Perrie Bull. Amer. Meteor. Soc., 93, 531-541, 2012. [2] G.-J. van Zadelhoff, et.al. Atmos. Meas. Tech. Discuss., 6, 7945-7984, doi:10.5194/amtd-6-7945-2013, 2013.

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

2014-05-01

61

Temperature effects on cadmium and mercury kinetics in freshwater molluscs under laboratory conditions  

Microsoft Academic Search

The temperature effects on Cd and Hg kinetics between the short-lived gastropod Viviparus georgianus (Lea) and the pelecypod Elliptio complanata (Lightfoot) were compared under laboratory conditions. A first order kinetic model was used to estimate, for different age classes and exposure temperatures, the following kinetic parameters; (1) the concentration at steady state conditions, (2) the depuration rate constant, (3) the

L. Tessier; G. Vaillancourt; L. Pazdernik

1994-01-01

62

Impacts of six bt rice lines on nontarget rice feeding thrips under laboratory and field conditions.  

PubMed

Nontarget impacts of six transgenic Bt rice lines (expressing the Cry1Ab or Cry1Ab/Cry1Ac protein) on the thrips, Stenchaetothrips biformis (Bagnall), attacking the rice seedling and tillering stages, were evaluated under laboratory and field conditions. Laboratory results showed relatively longer larval, pupal development and preoviposition durations of S. biformis. Although it had a shorter oviposition period, female adult longevity and less total laid eggs were found when fed on some tested Bt rice in comparison to non-Bt controls. S. biformis population dynamics in Bt and non-Bt plots were monitored using the plastic bag and beat plate methods. In the field, the temporal patterns of S. biformis population changes were similar between tested Bt rice lines and their respective control; however, the total number of S. biformis individuals collected from the Bt plots were significantly less or the same, varying from variety to variety, compared with those from the non-Bt plots. ELISA results showed that the Bt insecticidal protein could be transferred from Bt rice to the thrips, and the concentrations of the protein in rice leaves and thrips were not significantly correlated with some important biological parameters of the thrip. In addition, the potential effects of Bt rice on the abundance of S. biformis candidate predators are also discussed. In conclusion, our results show that the six Bt rice lines assessed may be less preferable host plants to S. biformis at the individual and population levels in comparison to the non-Bt rice plants. PMID:20388307

Akhtar, Z R; Tian, J C; Chen, Y; Fang, Q; Hu, C; Chen, M; Peng, Y F; Ye, G Y

2010-04-01

63

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

NASA Astrophysics Data System (ADS)

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 increases more quickly). The pH values in the Jaszcze and Jamne streams show only slight variation in the annual cycle and along the longitudinal profiles of the streams, and amount to 8.4-8.9. The Jamne stream, due to the lower discharge, is also characterised by greater conductivity of water in comparison to the Jaszcze stream. The mean value of conductivity of water in the Jamne stream is higher throughout year by around 60 microsiemens. During the 2012/2013 hydrological year, the total mineralization of water in the Jamne stream was greater than in the Jaszcze stream. The differences in the values ranged from 4.65 mg/l (in spring) to 13.88 mg/l (in autumn). The analysis of chemical composition showed that apart from the bicarbonate ions, the water in the Jaszcze and Jamne streams is rich in calcium and sulphates ions. The study also observed a relatively large percentage of iron ions in the overall chemical composition. The project is funded by the National Science Center (NN 306 659 940).

Buca?a, Anna; Wiejaczka, ?ukasz

2014-05-01

64

Cutaneous CD30 lymphoproliferative disorders and similar conditions: a clinical and pathologic prospective on a complex issue.  

PubMed

We elaborate on the diagnosis of CD30 positive cutaneous lymphoproliferative conditions including the various clinical and pathological presentations, our understanding of its pathomechanisms and prognostic implications. The most common reactive conditions that can simulate CD30 lymphoproliferative conditions, including arthropod bite reactions, various viral infections, pityriasis lichenoides and lymphocytic papules in myelodysplastic syndrome, are discussed in detail. PMID:20043512

Guitart, Joan; Querfeld, Christiane

2009-08-01

65

Recreation of Marine Atmospheric Corrosion Condition on Weathering Steel in Laboratory  

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

66

Assessment of biodegradability of plastics under simulated composting conditions in a laboratory test system  

Microsoft Academic Search

An automated laboratory-scale test system was developed for measuring the aerobic biodegradability of degradable plastics under simulated composting conditions. Biodegradation was monitored by measuring microbial carbon dioxide formation and oxygen consumption. Completeness of biodegradation was assessed in an aquatic test by conducting a carbon mass balance. The percentage of plastic carbon degraded to carbon dioxide, biomass and water-soluble byproducts were

Andreas Starnecker; Michael Menner

1996-01-01

67

Microbiological characteristics of a sandy loam soil exposed to tebuconazole and ?-cyhalothrin under laboratory conditions  

Microsoft Academic Search

Changes in microbiological properties of a sandy loam soil in response to the addition of different concentrations of fungicide tebuconazole and pyrethroid insecticide ?-cyhalothrin were assessed under laboratory conditions. To ascertain these changes, the potentially active soil microbial biomass, concentrations of ammonium and nitrate ions, numbers of total culturable bacteria, fungi, nitrogen-fixing bacteria, nitrifying and denitrifying bacteria were determined. Substrate-induced

M. Cyco?; Z. Piotrowska-Seget; A. Kaczy?ska; J. Kozdrój

2006-01-01

68

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

NASA Technical Reports Server (NTRS)

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.

Steffes, Paul G.

1991-01-01

69

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

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…

Balooch, Siavash Bandarian; Neumann, David L.

2011-01-01

70

Laboratory versus industrial cutting force sensor in tool condition monitoring system  

NASA Astrophysics Data System (ADS)

Research works concerning the utilisation of cutting force measures in tool condition monitoring usually present results and deliberations based on laboratory sensors. These sensors are too fragile to be used in industrial practice. Industrial sensors employed on the factory floor are less accurate, and this must be taken into account when creating a tool condition monitoring strategy. Another drawback of most of these works is that constant cutting parameters are used for the entire tool life. This does not reflect industrial practice where the same tool is used at different feeds and depths of cut in sequential passes. This paper presents a comparison of signals originating from laboratory and industrial cutting force sensors. The usability of the sensor output was studied during a laboratory simulation of industrial cutting conditions. Instead of building mathematical models for the correlation between tool wear and cutting force, an FFBP artificial neural network was used to find which combination of input data would provide an acceptable estimation of tool wear. The results obtained proved that cross talk between channels has an important influence on cutting force measurements, however this input configuration can be used for a tool condition monitoring system.

Szwajka, K.

2005-01-01

71

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

NASA Technical Reports Server (NTRS)

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.

Steffes, Paul G.

1987-01-01

72

Changes induced in the thermal properties of Galizian soils by the heating in laboratory conditions  

Microsoft Academic Search

The soil properties can be strongly affected by wildfires, causing direct effects on ecosystem productivity and sustainability.\\u000a These effects depend, among other things, on the soil type and on the temperature reached during the fire. The variations\\u000a of thermal properties of several Galizian soils heated in an oven in laboratory conditions at different temperatures (200–500 °C)\\u000a during 15 min have been examined

P. V. Verdes; J. Salgado

2011-01-01

73

Predatory potential of Nepa cinerea against mosquito larvae in laboratory conditions.  

PubMed

Biocontrol potential of nepidae bug, Nepa cinerea against immature stages of Anopheles stephensi, Anopheles culicifacies, Culex quinquefasciatus and Aedes aegypti was studied under laboratory conditions. It was found that N. cinerea had the highest predation against An. stephensi followed by An. culicifacies, Cmx quinquefasciatus and Ae. aegypti. From the analysis, it was found that N. cinerea has good predation efficacy. It can be used as a biological control agent to control of mosquito breeding in integrated disease vector control programme. PMID:16295671

Singh, R K; Singh, S P

2004-06-01

74

Efficacy of different steam distribution systems against five soilborne pathogens under controlled laboratory conditions  

Microsoft Academic Search

The efficacy of three steam application techniques (steam injection, iron pan and sheet steaming) was evaluated against five\\u000a soilborne pathogens under controlled laboratory conditions. Injection and pan steam systems proved to be efficient and feasible\\u000a alternatives to traditional sheet steaming for suppressing Fusarium oxysporum f. sp. basilici at 60% moisture field capacity in sandy-loam soil. Injecting steam was the best

Pingxiang Lu; Davide Ricauda Aimonino; Giovanna Gilardi; Maria Lodovica Gullino; Angelo Garibaldi

2010-01-01

75

Larval development of Neopisosoma neglectum werding, 1986 (Decapoda: Anomura: Porcellanidae) under laboratory conditions  

NASA Astrophysics Data System (ADS)

The complete larval development of the porcellanid crab Neopisosoma negluctum Werding, 1986, was studied under laboratory conditions. At 27°C, the megalopa appeared after 9 days. The development consists of a transitory prezoea, two zoeal stages and a megalopa stage. The larvae exhibit telsonal features which places them in the Petrolisthes-group of porcellanid larvae. Larval morphology gives no additional support for the status of Neopisosoma as an independent genus.

Werding, B.; Müller, H.-G.

1990-09-01

76

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

NASA Technical Reports Server (NTRS)

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.

Steffes, P. G.

1985-01-01

77

Comparison of the weight-loss degradability of various biodegradable plastics under laboratory composting conditions  

Microsoft Academic Search

Eight kinds of biodegradable plastics were compared for their degradability in controlled laboratory composting conditions.\\u000a A thin film of each plastic was mixed into the composting material, and weight-loss degradability was calculated from the\\u000a weight changes of the film during composting. It was found that weight-loss degradability strongly depended on the specific\\u000a kind of biodegradable plastic; two were very high,

Akihito Ohtaki; Kiyohiko Nakasaki

2000-01-01

78

Analysis of Turbulence Structure in the Surface Layer with a Modified Similarity Formulation for Near Neutral Conditions  

Microsoft Academic Search

Data from a recent detailed surface layer experiment are critically examined in terms of the turbulent kinetic energy budget and the other second order moment budgets formed by the three velocity components and temperature. In moderately unstable and slightly stable conditions nondimensional terms of all the moment budgets studied agree reasonably well with results reported from the Kansas study (after

Ulf Högström

1990-01-01

79

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

Microsoft Academic Search

We compared the outcomes of 141 consecutive patients who received allogeneic transplantation with either myeloablative (MA) or nonmyeloablative\\/reduced intensity (NMA) conditioning for non-Hodgkin and Hodgkin lymphoma at the University of Minnesota. All patients were transplanted between 1997 and 2004. NMA transplant recipients were older and received umbilical cord blood grafts more frequently (MA: 6 [9%]; NMA: 33 [43%], P <

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

2008-01-01

80

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

NASA Astrophysics Data System (ADS)

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, 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, the concept of a minimum state is introduced as the lowest Reynolds number turbulent flow that a time-dependent mixing transition must achieve to fulfill this objective. Later in the paper, the Reynolds number of the minimum state is determined as 1.6×105. The temporal criterion for the minimum state is also obtained. The efforts here can be viewed as a unification and extension of the concepts of both similarity scaling and transient mixing transition concepts. Finally, 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 progressively, a strategy is developed so that a progressively increasing range of dynamic structures and their statistical influences on evolving astrophysical flows can be attained in laboratory investigations.

Zhou, Ye

2007-08-01

81

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

PubMed

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

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

2009-01-01

82

Carrot infection by Alternaria radicina in field conditions and results of laboratory tests.  

PubMed

Carrot black rot caused by the fungus Alternaria radicina (Meier) Drechsler et Eddy, the economically important disease of carrot (Daucus carota L.). Research was carried out in 2004 and 2005 in order to establish correlation between plant infestation in the field and laboratory experiments. To determine the incidence and severity of the disease in mature crop, a 5-degree scale was used, where 1 meant no visible disease symptoms and 5 meant total foliage infestation. Plants were rated individually and the disease index was calculated. Fungus pathogenicity in laboratory conditions was determined using a petiole assay and a root disc assay. The petiole assay was conducted during the vegetation period; basal parts of petioles detached from fully developed carrot leaves were put in contact with the growing A. radicina mycelium. The root disc assay was conducted during storage of carrot roots; root discs were inoculated with toothpicks overgrown by A. radicina mycelium. The isolate of A. radicina was pathogenic to petioles and carrot discs. Differences in the reaction of the examined cultivars in the field and laboratory experiments were revealed. However, no significant correlation between plant infestation in the field and the results of laboratory experiments were observed. PMID:17390868

Szczeponek, A; Laszczak, P; Weso?owska, M; Grzebelus, D; Michalik, B

2006-01-01

83

Laboratory Studies of the Effects of Ambient Conditions, Soot Emissions, and Fuel Properties on Contrail Formation  

NASA Astrophysics Data System (ADS)

Contrail formation by aircraft can affect the global radiation budget and is the most uncertain component of aviation impacts on climate change. Field campaigns studying contrail formation have given insight into their formation pathways. However in order to improve simulations of contrail production, laboratory studies of the initial processes of contrail formation from aircraft-emitted soot are needed. As part of the Aviation Climate Change Research Initiative (ACCRI), laboratory studies of contrail formation from simulated aircraft emissions were performed at the particulate aerosol laboratory (PAL) at the NASA Glenn Research Center. The facility consists of a controlled soot source connected to a flow-through chamber which can simulate atmospheric conditions at altitudes up to 45,000 ft. Soot was made by a propane-fueled CAST generator and allowed to mix with water vapor and sulfuric acid to simulate aircraft emissions. Optical particle counters were employed at two distances from the nozzle tip that provided number concentration and size distributions of newly formed ice particles. The formation of ice particles is presented for chamber temperatures and pressures simulating altitudes between 15,000 and 40,000 feet. Initial results show the role of soot concentration, soot size, concentration of co-emitted pollutants and ambient conditions in ice particle formation.

Beyersdorf, A. J.; Anderson, B. E.; Bulzan, D.; Miake-Lye, R. C.; Tacina, K.; Thornhill, K. L.; Winstead, E.; Wong, H.; Ziemba, L. D.

2010-12-01

84

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

PubMed

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

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

2009-01-01

85

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

NASA Astrophysics Data System (ADS)

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.

Marcucci, Emma C.; Hynek, Brian M.

2014-03-01

86

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

NASA Technical Reports Server (NTRS)

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.

Steffes, Paul G.

1997-01-01

87

Speech discrimination and effectiveness of hearing aids under listening conditions similar to those of a transit operator.  

PubMed

Some controversy exists regarding regulations that permit hearing impaired drivers to operate passenger carrying vehicles. In other situations it has been shown that the hearing impaired generally have more difficulty than normals discriminating speech in noise. The present study investigates this under listening conditions simulating those of a transit operator, and also looks at the effects of a hearing aid on speech discrimination in the same situation. One normal hearing group and three groups representing varying degrees of symmetrical sensorineural hearing loss were given a sentence type discrimination test in a background of recorded diesel bus noise at different speech-to-noise ratios. The hearing impaired groups performed more poorly than normals and the use of hearing aids did not affect the performance of the hearing impaired groups. Regulations pertaining to licensing of transit operators should take into account hearing above 2,000 Hz. The results of this study, combined with the possibility of noise damage from amplified noise levels, lead us to conclude that hearing aids should not be worn by transit operators on the job. PMID:7277564

Lee, L A; Chung, D Y; Gannon, R P

1981-06-01

88

Global leukocyte DNA methylation is similar in African American and Caucasian women under conditions of controlled folate intake.  

PubMed

DNA methylation is an epigenetic feature that may modify disease risk, and can be influenced by folate status as well as by methylenetetrahydrofolate reductase (MTHFR) C677T genotype. The aim of this study was to investigate the influence of ethnicity/race on global leukocyte DNA methylation under conditions of controlled folate intake. Caucasian (n = 14) and African American (n = 14) women (18 - 45 y) possessing the MTHFR 677CC genotype consumed a folate restricted diet (135 mug/d as dietary folate equivalents, DFE) for 7 week followed by folate treatment with 400 or 800 microg DFE/d for 7 week. Global leukocyte DNA methylation was assessed via the cytosine extension assay at baseline (wk 0), after folate restriction (wk 7) and after folate treatment (wk 14). Ethnicity/race was not a determinant of global leukocyte DNA methylation. No differences (p > 0.05) were detected in DNA methylation between African American and Caucasian women at baseline or any other study time point. In addition, folate intake did not modify global leukocyte DNA methylation. These data suggest that global leukocyte DNA methylation does not differ between Caucasian and African American women and that short-term folate restriction is not sufficient to modify methylation content in young women with the MTHFR 677CC genotype. PMID:17965592

Axume, Juan; Smith, Steven S; Pogribny, Igor P; Moriarty, David J; Caudill, Marie A

2007-01-01

89

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

PubMed

Main components of carbonaceous matter in carbonaceous chondrites are high molecular organic matter. Examinations of the compounds using pyrolysis GC/MS and FT-IR indicated the structural resemblance of major part of the molecule for all of the compounds from different types of carbonaceous chondrites (8 Antarctic and 2 none-Antarctic meteorites). A carbonaceous matter derived from graphite on a shock experiment using a rail gun (1g projectile at 7 km/s) showed similar IR spectrum to those of the meteoritic high-molecular organic matter. C-60 fullerene also gave a similar compound (with minor differences in IR spectra) on a shock experiment under the same conditions. A shock experiment using coronene also examined. PMID:11541332

Murae, T

1997-01-01

90

Laboratory modeling of air-sea interaction under severe wind conditions  

NASA Astrophysics Data System (ADS)

Wind-wave interaction at extreme wind speed is of special interest now in connection with the problem of explanation of the sea surface drag saturation at the wind speed exceeding 30 m/s. The idea on saturation (and even reduction) of the coefficient of aerodynamic resistance of the sea surface at hurricane wind speed was first suggested by Emanuel (1995) on the basis of theoretical analysis of sensitivity of maximum wind speed in a hurricane to the ratio of the enthalpy and momentum exchange coefficients. Both field (Powell, Vickery, Reinhold, 2003, French et al, 2007, Black, et al, 2007) and laboratory (Donelan et al, 2004) experiments confirmed that at hurricane wind speed the sea surface drag coefficient is significantly reduced in comparison with the parameterization obtained at moderate to strong wind conditions. Two groups of possible theoretical mechanisms for explanation of the effect of the sea surface drag reduction can be specified. In the first group of models developed by Kudryavtsev & Makin (2007) and Kukulka,Hara Belcher (2007), the sea surface drag reduction is explained by peculiarities of the air flow over breaking waves. Another approach more appropriate for the conditions of developed sea exploits the effect of sea drops and sprays on the wind-wave momentum exchange (Andreas, 2004; Makin, 2005; Kudryavtsev, 2006). The main objective of this work is investigation of factors determining momentum exchange under high wind speeds basing on the laboratory experiment in a well controlled environment. The experiments were carried out in the Thermo-Stratified WInd-WAve Tank (TSWIWAT) of the Institute of Applied Physics. The parameters of the facility are as follows: airflow 0 - 25 m/s (equivalent 10-m neutral wind speed U10 up to 60 m/s), dimensions 10m x 0.4m x 0.7 m, temperature stratification of the water layer. Simultaneous measurements of the airflow velocity profiles and wind waves were carried out in the wide range of wind velocities. Airflow velocity profile was measured by WindSonic ultrasonic wind sensor. The water elevation was measured by the three-channel wave-gauge. Top and side views of the water surface were fixed by CCD-camera. Wind friction velocity and surface drag coefficients were retrieved from the measurements by the profile method. Obtained values are in good agreement with the data of measurements by Donelan et al (2004). The directional frequency-wave-number spectra of surface waves were retrieved by the wavelet directional method (Donelan et al, 1996). The obtained dependencies of parameters of the wind waves indicate existing of two regimes of the waves with the critical wind speed Ucr about 30 m/s. For U10Ucr the dependencies of peak wave period, peak wavelength, significant wave height on the wind speed tend to saturation, in the same time the peak wave slope has the maximum at approximately Ucr and then decreases with the tendency to saturation. The surface drag also tends to saturation for U10>Ucr similarly to (Donelan et al, 2004). Video filming indicates onset of wave breaking with white-capping and spray generation at wind speeds approximately equal to Ucr. We compared the obtained experimental dependencies with the predictions of the quasi-linear model of the turbulent boundary layer over the waved water surface (Reutov&Troitskaya, 1995). Comparing shows that theoretical predictions give low estimates for the measured drag coefficient and wave fields. Taking into account momentum flux associated with the spray generation yields theoretical estimations in good agreement with the experimental data. Basing on the experimental data a possible physical mechanism of the drag is suggested. Tearing of the wave crests at severe wind conditions leads to the effective smoothing (decreasing wave slopes) of the water surface, which in turn reduces the aerodynamic roughnes

Troitskaya, Yuliya; Vasiliy, Kazakov; Nicolay, Bogatov; Olga, Ermakova; Mikhail, Salin; Daniil, Sergeev; Maxim, Vdovin

2010-05-01

91

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

PubMed

Evaluating field-scale methane oxidation in landfill cover soils using numerical models is gaining interest in the solid waste industry as research has made it clear that methane oxidation in the field is a complex function of climatic conditions, soil type, cover design, and incoming flux of landfill gas from the waste mass. Numerical models can account for these parameters as they change with time and space under field conditions. In this study, we developed temperature, and water content correction factors for methane oxidation parameters. We also introduced a possible correction to account for the different soil structure under field conditions. These parameters were defined in laboratory incubation experiments performed on homogenized soil specimens and were used to predict the actual methane oxidation rates to be expected under field conditions. Water content and temperature corrections factors were obtained for the methane oxidation rate parameter to be used when modeling methane oxidation in the field. To predict in situ measured rates of methane with the model it was necessary to set the half saturation constant of methane and oxygen, K(m), to 5%, approximately five times larger than laboratory measured values. We hypothesize that this discrepancy reflects differences in soil structure between homogenized soil conditions in the lab and actual aggregated soil structure in the field. When all of these correction factors were re-introduced into the oxidation module of our model, it was able to reproduce surface emissions (as measured by static flux chambers) and percent oxidation (as measured by stable isotope techniques) within the range measured in the field. PMID:21196106

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

2011-05-01

92

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

SciTech Connect

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.

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

2004-04-30

93

Consistent null-energy-condition violation: Towards creating a universe in the laboratory  

NASA Astrophysics Data System (ADS)

The null energy condition (NEC) can be violated in a consistent way in models with unconventional kinetic terms, notably, in Galileon theories and their generalizations. We make use of one of these, the scale-invariant kinetic braiding model, to discuss whether a universe can in principle be created by manmade processes. We find that, even though the simplest models of this sort can have both healthy Minkowski vacuum and a consistent NEC-violating phase, there is an obstruction for creating a universe in a straightforward fashion. To get around this obstruction, we design a more complicated model and present a scenario for the creation of a universe in the laboratory.

Rubakov, V. A.

2013-08-01

94

Numerical and laboratory experiment of volumetrically heated fluid: implications of boundary conditions on planetary evolution.  

NASA Astrophysics Data System (ADS)

In the last decade numerical simulations of mantle convection have included an increasing number of physical processes (e.g., phase transitions, compositional heterogeneities, depth dependent properties), to gain a better understanding of the Earth's thermal evolution. This increasing complexity has led to a more precise description of the convective behavior of the Earth's mantle, but may have render its deciphering somewhat more difficult and sometimes ambiguous. Coupled experimental and numerical studies are then useful to interpret the results of the modeling. Here we present numerical simulations of a simple system, which is only cooled from above and internally heated, coupled with innovative laboratory experiments. Three-dimensional simulations are conducted with the code Stag3D [Tackley 1993], and the laboratory experiments used a newtonian fluid whose viscosity and thermal expansion are both temperature dependent. The experimental approach, presented in detail in a companion abstract by Limare at al. (EGU2014-6207), is very challenging and it was first important to validate numerically the experimentally measured temperature and velocity fields. We then used the combined approach to quantify the effect of boundary conditions (i.e., rigid, as in the laboratory experiments, or free slip) on the internal thermal structure of the convective fluid. In particular, we calculate the horizontally and time-averaged temperature across the top thermal boundary layer for a large range of Rayleigh number (105

Vilella, Kenny; Limare, Angela; Kaminski, Edouard; Farnetani, Cinzia G.; Jaupart, Claude; Surducan, Emanoil; Di Giuseppe, Erika; Surducan, Vasile; Neamtu, Camelia; Fourel, Loic

2014-05-01

95

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

NASA Technical Reports Server (NTRS)

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.

Steffes, P. G.

1986-01-01

96

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

PubMed

In order to describe the developmental biology of the tick Argas neghmei Kohls & Hoogstraal under laboratory conditions, 40 females and 40 males were collected from chicken coops located in Calama (II Region, Chile). They were fed on chickens and maintained under two laboratory conditions: one group at 30 +/- 5 degrees C and 35 +/- 5 % RH and another at 27 +/- 5 degrees C and 80 +/- 5 % RH, both at 12: 12 h L:D photoperiod. The ticks were observed daily to determine larval feeding periods, preoviposition, oviposition, egg incubation as well as the frequency of egg laying, number of eggs laid, and percentage of larval hatching. Females did not lay eggs at 80 +/- 5% RH, and data on the biology of this tick was obtained only at 35 +/- 5% RH. The life cycle of A. neghmei lasted an average of 269 days. Feeding period of each nymphal stage as well as of adult females between oviposition events lasted less than a day. Females laid on average 1.8 egg batches and egg-laying period lasted on average 14 days, during which about 96 eggs were laid per female. PMID:20498950

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

2010-01-01

97

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

NASA Technical Reports Server (NTRS)

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.

Steffes, Paul G.

1998-01-01

98

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

NASA Technical Reports Server (NTRS)

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, both spacecraft- and earth-based, in order to determine the identity and abundance profiles of constituents in those planetary atmospheres,

Steffes, Paul G.

2002-01-01

99

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

PubMed

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 30x30x30 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

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

2012-11-01

100

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

NASA Technical Reports Server (NTRS)

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.

Steffes, Paul G.

1992-01-01

101

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

PubMed

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

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

2000-09-01

102

The Life Cycle of the Root Borer, Oryctes agamemnon, Under Laboratory Conditions  

PubMed Central

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.

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

2008-01-01

103

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

SciTech Connect

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.

Ball, H.A.; Reinhard, M. [Stanford Univ., CA (United States). Western Region Hazardous Substance Research Center

1996-02-01

104

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

Code of Federal Regulations, 2013 CFR

...Laboratories performing high complexity testing; cytology general supervisor. 493.1467 Section...Laboratories performing high complexity testing; cytology general supervisor. For the subspecialty of cytology, the laboratory must have a general...

2013-10-01

105

Laboratory measurements and a consistent model of the microwave properties of ammonia under jovian conditions  

NASA Astrophysics Data System (ADS)

Nearly 1200 laboratory measurements of the 5-20 cm wavelength properties of ammonia have been conducted in a hydrogen/helium environment under simulated deep tropospheric jovian conditions (pressures up to 100 bars and temperatures up to 500 K) using an ultra-high-pressure measurement system built at Georgia Tech [1]. These measurements along with nearly 1800 measurements of the 0.8-20 cm wavelength properties of ammonia performed under middle tropospheric jovian conditions by Hanley et al., [2] and over 1000 measurements of the 2-4 mm wavelength properties of ammonia performed under upper tropospheric jovian conditions by Devaraj et al., [3] have been used to develop a consistent mathematical formalism to represent the opacity of ammonia in the 0.1- 30 cm wavelength range in a hydrogen/helium environment at pressures up to 100 bars and temperatures up to 500 K. The new model can be used for accurate retrievals of ammonia and other constituents in the jovian atmospheres from ground-based and spacecraftbased microwave observations.

Devaraj, K.; Steffes, P.

2011-10-01

106

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

USGS Publications Warehouse

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.

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

2000-01-01

107

A Laboratory Exercise to Illustrate Increased Salivary Cortisol in Response to Three Stressful Conditions Using Competitive ELISA  

NSDL National Science Digital Library

Here, we outline a laboratory exercise that uses a competitive ELISA kit to illustrate the response of salivary cortisol concentrations to three stressful conditions: presentation stress, fasting stress, and competition stress

Mark F. Haussmann (Iowa State University Department of Ecology, Evolution, and Organismal Biology); Carol M. Vleck (Iowa State University Department of Ecology, Evolution, and Organismal Biology); Eugenia S. Farrar (Iowa State University Department of Ecology, Evolution, and Organismal Biology)

2007-03-01

108

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

PubMed

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

Courtney, J C; Klann, R T

1997-01-01

109

Measured and calculated evaporation losses of two petroleum hydrocarbon herbicide mixtures under laboratory and field conditions  

SciTech Connect

Evaporation rates of two weed oils were measured under laboratory and field conditions. Rates were also calculated by assuming first-order evaporation of the oil components (represented by hydrocarbon references). Beacon selective and Chevron nonselective weed oils exhibited evaporation rates 1.4-1.9 and 0.9 times the calculated rates, respectively, for 8-10 mg/cm/sup 2/ on inert surfaces in the laboratory. The relative rates were increased to 3-15 (Beacon) and 1.6 (Chevron) under a slight breeze (0.43 m/s) with turbulence. The half-life of Beacon oil applied at 6-7 mg/cm/sup 2/ to moist soil in an unplanted field was 51 min (10-20/sup 0/C), while the calculated half-life was 57 min. In an alfalfa field, 90% of the Chevron oil from a deposit of 0.15-0.22 mg/cm/sup 2/ (20-40/sup 0/C) evaporated in 26-45 and 53-127 min from glass plates and paper filters, respectively; average calculated time was 40 min. Evaporation rates from alfalfa foliage and glass plates compared well. 15 references, 6 figures, 8 tables.

Woodrow, J.E.; Seiber, J.N.; Kim, Y.

1986-08-01

110

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

NASA Technical Reports Server (NTRS)

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.

Steffes, Paul G.

1992-01-01

111

Numerical simulations of thermal convection in rotating spherical shells under laboratory conditions  

NASA Astrophysics Data System (ADS)

An exhaustive study, based on numerical three-dimensional simulations, of the Boussinesq thermal convection of a fluid confined in a rotating spherical shell is presented. A moderately low Prandtl number fluid (?=0.1) bounded by differentially-heated solid spherical shells is mainly considered. Asymptotic power laws for the mean physical properties of the flows are obtained in the limit of low Rossby number and compared with laboratory experiments and with previous numerical results computed by taking either stress-free boundary conditions or quasi-geostrophic restrictions, and with geodynamo models. Finally, using parameters as close as possible to those of the Earth's outer core, some estimations of the characteristic time and length scales of convection are given.

Garcia, Ferran; Sánchez, Juan; Net, Marta

2014-05-01

112

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

NASA Astrophysics Data System (ADS)

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.

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

2009-09-01

113

Consistency of Rain Splash Soil Erosion under Controlled Laboratory Flume Conditions  

NASA Astrophysics Data System (ADS)

Prediction of soil erosion is challenging due to the wide range of factors that can affect it. At the catchment scale, for instance, inconsistent soil erosion yields have been reported in numerous studies. Explanations involve nonlinearities in these contributing factors and their interactions (such as soil surface properties, precipitation characteristic, topography and land cover). Controlled laboratory flume experiments provide a means to improve our process physical understanding. Here, we report on experiments wherein the dependence of rain-splash soil erosion on the precipitation rate, area of soil exposed and initial soil conditions was investigated using laboratory flume experiments. The role of these factors on predicting experimental results was examined based on a prototype experiment and area-based approach. That is, we hypothesised that flume erosion can be predicted by a simple linear scaling of the different factors. Fourteen experiments were carried out in which we varied the precipitation rate (28, 60 and 74 mm/h), the fraction of surface rock fragments (20, 30, and 40%) and initial soil conditions (dry hand-cultivated, wet sealed-compacted and dry compacted). In addition, the influence of time was investigated by considering different experiment durations (2-5 h). In all experiments, we measured the discharge rate, the total sediment concentration and the sediment concentrations of the individual size classes at the flume exit. The presence of surface rock fragments on the soil surface prevents surface sealing and reduces the cross-sectional area available for flow, thereby affecting the development of steady-state equilibrium. Results revealed that, generally, estimates of the individual size classes' sediment concentrations, taking the exposed area into account, reproduce satisfactorily the measured data at steady state, independent of the initial conditions and rainfall intensity. Before steady state, however, the main feature in most sediment size classes is an early concentration peak, which was found not to be proportional to the area exposed and effective rainfall. Rather, results showed that the short time behaviour is mainly controlled by the soil antecedent and initial conditions, such as surface sealing, surface compaction and soil moisture. In addition, findings suggested that the larger size classes are more sensitive to prior soil conditions than the finer size classes. It was found, also, that this proportionality of erosion to area of exposed soil can be obtained for the entire erosive event under carefully controlled conditions. Steady state erosion rates, based on a prototype precipitation, were within a factor two of measured rates, for total and individual size classes. However, at short times, erosion due to raindrop splash is not proportionally controlled by the precipitation rate. Overall, the results thus indicate that, for a given soil, experimental data based on a given rainfall rate can be used as a rough estimator of the steady rate of erosion for a different rainfall rates.

Jomaa, Seifeddine; Barry, D. Andrew; Sander, Graham G.; Parlange, J.-Yves

2014-05-01

114

Protocol for laboratory testing of crude-oil bioremediation products in freshwater conditions.  

PubMed

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 [18]. The marine protocol was adapted for application in freshwater environments by using a chemically defined medium and an oil-degrading consortium as a positive control. Four products were tested using the modified protocol: two with nutrients and an oleophilic component; one with nutrients, sorbent, and organisms; and one microbial stimulant. A separate experiment evaluated the use of HEPES and MOPSO buffers as replacements for phosphate buffer. The oleophilic nutrient products yielded oil degradation similar to the positive control, with an average alkane removal of 97.1+/-2.3% and an aromatic hydrocarbon removal of 64.8+/-1.2%. The positive control, which received inoculum plus nutrients, demonstrated alkane degradation of 98.9+/-0.1% and aromatic degradation of 52.9+/-0.1%. The sorbent-based product with inoculum failed to demonstrate oil degradation, while the microbial stimulant showed less oil degradation than the positive control. Replacement of phosphate buffer with other buffers had no significant effect on one product's performance. Differences in product performance were easily distinguishable using the protocol, and performance targets for alkane and aromatic hydrocarbon degradation are suggested. PMID:12612785

Haines, J R; Koran, K M; Holder, E L; Venosa, A D

2003-02-01

115

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

SciTech Connect

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

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

1989-07-02

116

Germination of Ocotea pulchella (Nees) Mez (Lauraceae) seeds in laboratory and natural restinga environment conditions.  

PubMed

The germination response of Ocotea pulchella (Nees) Mez seeds to light, temperature, water level and pulp presence is introduced. The laboratory assays were carried out in germination chambers and thermal-gradient apparatus, whereas the field assays were performed in environments with distinct light, temperature and soil moisture conditions within a permanent parcel of Restinga forest of the Parque Estadual da Ilha do Cardoso, Cananéia, São Paulo. The seeds do not exhibit dormancy, they are non photoblastic, and a loss of viability in dry stored seeds can be related to a decrease in water content of the seed. The presence of the pulp and the flooded substratum influenced negatively the germination of O. pulchella seeds tested in the laboratory. Otherwise, light and temperature probably are not limiting factors of the germination of O. pulchella seeds in the natural environment of Restinga. The optimum temperature range for germination of Ocotea pulchella seeds was 20 to 32 degrees C, the minimum or base temperature estimated was 11 degrees C and the maximum ranged between 33 and 42 degrees C. The isotherms exhibited a sigmoidal pattern well described by the Weibull model in the sub-optimal temperature range. The germinability of O. pulchella seeds in the understorey, both in wet and dry soil, was higher than in gaps. Germination was not affected by fluctuations in soil moisture content in the understorey environment, whereas in gaps, germination was higher in wet soils. Thus, the germination of this species involves the interaction of two or more factors and it cannot be explained by a single factor. PMID:19802455

Pires, L A; Cardoso, V J M; Joly, C A; Rodrigues, R R

2009-08-01

117

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

SciTech Connect

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.

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

1990-08-01

118

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

NASA Technical Reports Server (NTRS)

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.

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

119

Biotransformation of BTEX under anaerobic, denitrifying conditions: Field and laboratory observations  

NASA Astrophysics Data System (ADS)

Three natural-gradient injection experiments in the Borden aquifer (Ontario, Canada) (˜ 100-300 days in duration) and a 452-day laboratory microcosm experiment were performed to evaluate the biotransformation of BTEX (benzene, toluene, ethylbenzene and o-, m-, p-xylenes) derived from gasoline under anaerobic, denitrifying conditions. Both NO 3-- amended and unamended control (i.e. no NO 3- added) experiments were performed. In the unamended control injection experiment, toluene biotransformed between 1 and 5 m from the injection well. All other aromatic compounds were recalcitrant in this field experiment and all aromatic compounds were recalcitrant in unamended control microcosms. After an acclimatization period, toluene biotransformed relatively rapidly in the presence of NO 3- in both the laboratory and field to a residual level of ˜ 100 ?g L -1. In the presence of NO 3- the xylene isomers and ethylbenzene biotransformed to a lesser degree. Benzene was recalcitrant in all experiments. The acetylene blockage technique was used to demonstrate that denitrifying bacteria were active in the presence of NO 3-. In the NO 3--amended injection experiments, little BTEX mass loss occurred beyond the 1-m multilevel-piezometer fence. However, NO 3- continued to decline downgradient, suggesting that other sources of carbon were being utilized by denitrifying bacteria in preference to residual BTEX. In addition to observations on mass loss, these experiments provided evidence of inhibition of BTEX biotransformation in the presence of acetylene, and competitive utilization between toluene, ethylbenzene and the xylene isomers. Given the recalcitrance of benzene and high thresholds of the compounds that did biotransform, the addition of NO 3- as an alternate electron acceptor would not be successful in this aquifer as a remedial measure.

Barbaro, J. R.; Barker, J. F.; Lemon, L. A.; Mayfield, C. I.

1992-11-01

120

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

SciTech Connect

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.

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

2008-03-05

121

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

PubMed Central

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 (?) 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.

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

2013-01-01

122

Degradation of fipronil under laboratory conditions in a tropical soil from sirinhaém pernambuco, Brazil.  

PubMed

The objective of this research was to assess the degradation of fipronil [5-amino-1-(2,6-dichloro-alpha,alpha,alpha -trifluoro-p-tolyl)-4-trifluoromethylsulfinylpyrazole-3-carbonitrile] in soils from sugar cane fields in Northeastern Brazil. Degradation experiments were carried out under laboratory conditions (controlled temperature and in the dark), where sterile and non-sterile soils (Ustoxs) were incubated [under moisture content of 55% of the water holding capacity (WHC)] and analyzed for fipronil disappearance and metabolite formation. Microbial communities present in the soil degrade fipronil. However, biodegradation seems to be dependent on the bioavailability of the fipronil and the half-life according to the zero-order model. Fipronil degradation rate appeared to be biphasic. Degradation fipronil ranged from 83 days (initial concentration = 978 ng g(-1); short-term experiment) to 200 days (initial concentration = 689 ng g(-1); long-term experiment). This an initial slower rate followed by a faster rate after 90 days of incubation may lead to shorter half-life than that calculated with the zero-order model. The sulfone derivative (an oxidation product) was the predominant metabolite, but the sulfide (a reduction product) and amide (a hydrolysis product) derivatives were also formed under non-sterile conditions after 120 days of incubation. The metabolites underwent further biodegradation, particularly the sulfone derivative. Bioavailability appears to affect fipronil degradation in soils with an effective capacity to adsorb fipronil (such as Ustoxs), while redox potential was important for the formation of metabolites. Despite the fine texture, more aerobic sites were present, thus favoring the formation of the sulfone metabolite over that of the sulfide metabolite. Therefore, microaggregation of Ustoxs, with high clay content, played a very important role in determining the types of metabolites formed. PMID:17162566

Masutti, Carmem S M; Mermut, Ahmet R

2007-01-01

123

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

PubMed

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

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

2003-07-01

124

Assessment of metolachlor and diuron leaching in a tropical soil using undisturbed soil columns under laboratory conditions.  

PubMed

In the present study, diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-metoxi-1-methylethyl)acetamide] leaching was studied in undisturbed soil columns collected in a cotton crop area in Mato Grosso State, Brazil. The pesticides were applied to the soil surface in dosages similar to those used in a cotton plantation. To assess the leaching process, soil columns were submitted to simulated rain under laboratory conditions at 25 ± 3°C, in the absence of wind and direct solar radiation. During the rain simulations, leachate solutions were collected and herbicide concentrations were determined. At the end of the experiment, the soil columns were cut into 10 cm sections to determine the remaining herbicide concentrations through the soil profile. Metolachlor was detected in all soil sections, and approximately 4% of the applied mass was leached. Diuron was detected only in the upper two soil sections and was not detected in the leachate. A linear correlation (r > 0.94) between the metolachlor soil concentrations and the organic contents of the soil sections was observed. Mass balance suggests that around 56% of diuron and 40% of metolachlor were degraded during the experiments. Measurements of the water table depth in the area where the samples were collected showed that it varied from 2 to 6 m and is therefore vulnerable to contamination by the studied herbicides, particularly metolachlor, which demonstrated a higher leaching potential. PMID:23305279

Dores, Eliana F G C; De Souza, Luana; Villa, Ricardo D; Pinto, Alicio Alves

2013-01-01

125

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

NASA Astrophysics Data System (ADS)

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 ?g·g -1 lipid for PCB-exposed fish, 10 ?g·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.

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

126

Laboratory Study of Water Ice Growth Rates at Martian Atmosphere Conditions  

NASA Astrophysics Data System (ADS)

The formation and growth of water ice clouds play a pivotal role in the martian hydrological cycle, and any robust model of the climate of Mars must account for the effects of these processes. Unfortunately, the growth behavior of water ice at temperatures and pressures relevant to martian studies is not well characterized, requiring modelers to rely on extrapolations from data sets typically taken from terrestrial literature. The present laboratory study charts the growth rate of water ice as a function of temperature (approximately -120 to -80°C) and pressure (approximately 1E-7 to 1E-4 Torr), principally in the phase space between nucleation and the vapor/solid equilibrium line. The appearance and subsequent growth of ice on a silicon wafer were monitored via infrared spectroscopy, and the time derivative of the characteristic water ice absorbance band was used to calculate net rates of deposition and sublimation as pressure and temperature were varied around equilibrium. These data were further interpreted to yield values for the net sticking coefficient of vapor phase molecules to the ice surface. These results will be beneficial to modelers of the martian climate, as they provide further insight into how quickly martian water ice clouds should be expected to form and dissipate under a given set of conditions.

Mar, B. D.; Phebus, B. D.; Colaprete, A.; Stone, B. M.; Iraci, L. T.

2009-12-01

127

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

PubMed Central

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.

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

2012-01-01

128

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

PubMed

To clarify the environmental fate of the Cry1Ac protein from Bacillus thuringiensis subsp. kurstaki (Bt) contained in transgenic rice plant stubble after harvest, degradation was monitored under field conditions using an enzyme-linked immunosorbent assay. In stalks, Cry1Ac protein concentration decreased rapidly to 50% of the initial amount during the first month after harvest; subsequently, the degradation decreased gradually reaching 21.3% when the experiment was terminated after 7 mo. A similar degradation pattern of the Cry1Ac protein was observed in rice roots. However, when the temperature increased in April of the following spring, protein degradation resumed, and no protein could be detected by the end of the experiment. In addition, a laboratory experiment was conducted to study the persistence of Cry1Ac protein released from rice tissue in water and paddy soil. The protein released from leaves degraded rapidly in paddy soil under flooded conditions during the first 20 d and plateaued until the termination of this trial at 135 d, when 15.3% of the initial amount was still detectable. In water, the Cry1Ac protein degraded more slowly than in soil but never entered a relatively stable phase as in soil. The degradation rate of Cry1Ac protein was significantly faster in nonsterile water than in sterile water. These results indicate that the soil environment can increase the degradation of Bt protein contained in plant residues. Therefore, plowing a field immediately after harvest could be an effective method for decreasing the persistence of Bt protein in transgenic rice fields. PMID:18284753

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

2007-10-01

129

A Comparison of Entomopathogenic Nematode Longevity in Soil under Laboratory Conditions  

PubMed Central

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

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

2006-01-01

130

Photosynthetic acclimation responses of maize seedlings grown under artificial laboratory light gradients mimicking natural canopy conditions.  

PubMed

In this study we assessed the ability of the C4 plant maize to perform long-term photosynthetic acclimation in an artificial light quality system previously used for analyzing short-term and long-term acclimation responses (LTR) in C3 plants. We aimed to test if this light system could be used as a tool for analyzing redox-regulated acclimation processes in maize seedlings. Photosynthetic parameters obtained from maize samples harvested in the field were used as control. The results indicated that field grown maize performed a pronounced LTR with significant differences between the top and the bottom levels of the plant stand corresponding to the strong light gradients occurring in it. We compared these data to results obtained from maize seedlings grown under artificial light sources preferentially exciting either photosystem II or photosystem I. In C3 plants, this light system induces redox signals within the photosynthetic electron transport chain which trigger state transitions and differential phosphorylation of LHCII (light harvesting complexes of photosystem II). The LTR to these redox signals induces changes in the accumulation of plastid psaA transcripts, in chlorophyll (Chl) fluorescence values F \\rm s/F \\rm m, in Chl a/b ratios and in transient starch accumulation in C3 plants. Maize seedlings grown in this light system exhibited a pronounced ability to perform both short-term and long-term acclimation at the level of psaA transcripts, Chl fluorescence values F \\rm s/F \\rm m and Chl a/b ratios. Interestingly, maize seedlings did not exhibit redox-controlled variations of starch accumulation probably because of its specific differences in energy metabolism. In summary, the artificial laboratory light system was found to be well-suited to mimic field light conditions and provides a physiological tool for studying the molecular regulation of the LTR of maize in more detail. PMID:24062753

Hirth, Matthias; Dietzel, Lars; Steiner, Sebastian; Ludwig, Robert; Weidenbach, Hannah; And, Jeannette Pfalz; Pfannschmidt, Thomas

2013-01-01

131

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

NASA Astrophysics Data System (ADS)

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 ratios of CH4:N2 clathrate hydrates.

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

2013-12-01

132

Chemical and mutagenic properties of asphalt fume condensates generated under laboratory and field conditions  

Microsoft Academic Search

Exposure to asphalt fumes is widely recognized as a potential occupational health concern for paving and roofing workers. Two studies suggest that asphalt fumes generated in the laboratory are carcinogenic to mice. In this study, asphalt fume condensate (AFC) was collected from the head space of an operating hot mix asphalt storage tank and from a laboratory fume-generating apparatus operating

Gerald Reinke; Mark Swanson; Dennis Paustenbach; John Beach

2000-01-01

133

Effects of insemination and blood-feeding on locomotor activity of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) females under laboratory conditions  

PubMed Central

Background Dengue is an arbovirus disease transmitted by two Aedes mosquitoes: Ae. aegypti and Ae. albopictus. Virgin females of these two species generally show a bimodal and diurnal pattern of activity, with early morning and late afternoon peaks. Although some studies on the flight activity of virgin, inseminated and blood-fed Ae. aegypti females have been carried out under laboratory conditions, little is known about the effects of such physiological states on the locomotor activity of Ae. albopictus and Ae. aegypti females. The aim of this study was to analyze, under laboratory conditions, the effects of insemination and blood-feeding on the locomotor activity of Ae. albopictus and Ae. aegypti females under LD 12:12, at 25°C. Methods Both Ae. albopictus and Ae. aegypti females were obtained from established laboratory colonies. Control groups were represented by virgin/unfed Ae. albopictus and Ae. aegypti females. Experiments were conducted under laboratory conditions, using an activity monitor that registers individual activity every thirty minutes. Results Virgin/unfed Ae. albopictus and Ae. aegypti females showed a diurnal and bimodal pattern of locomotor activity, with peaks at early morning and late afternoon. Insemination and blood-feeding significantly decreased the locomotor activity of Ae. aegypti females, but inseminated/blood-fed Ae. aegypti and Ae. albopictus females showed a similar significant decrease on the locomotor activity compared to virgin/unfed females. Conclusions This study is the first demonstration of the effects of insemination and blood-feeding on the locomotor activity of Ae. albopictus and Ae. aegypti females under artificial conditions. Data suggest that Ae. albopictus and Ae. aegypti females respond in different ways to physiological status changes and such divergence between these two dengue vectors, associated with several ecological differences, could be related to the greater dengue vectorial capacity of Ae. aegypti in Americas in comparison to Ae. albopictus.

2014-01-01

134

Efficacy of quinoa ( Chenopodium quinoa) saponins against golden apple snail ( Pomacea canaliculata) in the Philippines under laboratory conditions  

Microsoft Academic Search

A novel product for managing Pomacea canaliculata, golden apple snail (GAS), containing quinoa saponins (Chenopodium quinoa), was evaluated under laboratory conditions for the protection of newly sprouted rice seeds. Experimental methods mimicked conditions found in direct-seeded rice cultivation in the Philippines, but with a very high GAS density (90snails\\/m2). Protection of newly sprouted seeds was directly proportional to saponin concentration

Ravindra C. Joshi; Ricardo San Martín; Cesar Saez-Navarrete; John Alarcon; Javier Sainz; Mina M. Antolin; Antonio R. Martin; Leocadio S. Sebastian

2008-01-01

135

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

Microsoft Academic Search

A laboratory reactor planted with Juncus effusus treating an artificial wastewater was used to investigate the short-term and long-term variations and interactions in the redox conditions as well as the removal efficiency of C and the N turnover. The permanent circulation of the process water enabled the micro-gradient processes to be evaluated for an operating period of 20 months.Steady-state conditions

A. Wießner; U. Kappelmeyer; P. Kuschk; M. Kästner

2005-01-01

136

Survival and food choice of the grey field slug ( Deroceras reticulatum ) on three different seed types under laboratory conditions  

Microsoft Academic Search

In Ireland, the grey field slug (Deroceras reticulatum) is the predominant slug pest species in arable crops. It can cause enormous damage, but the knowledge about its feeding biology is limited.Adult species were reared under laboratory conditions, and the survival, feeding activity, and weight change of slugs when feed on maize, peas, or wheat seeds were investigated. An especially high

J. Gebauer

2002-01-01

137

Assessing biological control of Acarus siro by Cheyletus malaccensis under laboratory conditions: Effect of temperatures and prey density  

Microsoft Academic Search

In stored grain, the predatory mite Cheyletus spp. may be used to control the pest mite Acarus siro. The efficiency of control depends on many factors, particularly ambient temperature. In this study we investigated the effects of temperature and initial prey density on the prey–predator system under laboratory conditions. Ratio–response models were fitted to estimate the efficiency of control for

Stano Pekár; Jan Hubert

2008-01-01

138

The effects of plant extracts on apple aphid (Homoptera: Aphis pomiDe Geer) under laboratory conditions  

Microsoft Academic Search

under laboratory conditions. The apple aphid is one ofthe most resistant pests against insecticides throughout the Central Europe The selection ofirsecticide-resistdnce pest biotypes can be delayed by decreasing the frequency and intensity of genetic selection This might be accomplished by applying insecticides only when and where absolutely necessary and in ntinimunt acceptable amount or to involve methods and use different

LASZLO FERENCZI

139

Accumulation, depuration and distribution of cadmium and zinc in the green-lipped mussel Perna viridis (Linnaeus) under laboratory conditions  

Microsoft Academic Search

Ecotoxicological tests were conducted in the green-lipped mussel Perna viridis under laboratory conditions. Different rates of accumulation and depuration in soft tissues are found and this might be due to different mechanisms of metal binding and regulation. At the end of depuration, Cd levels in soft tissues of P. viridis were 10–30 times higher than before exposure, while Zn levels

C. K. Yap; A. Ismail; S. G. Tan; H. Omar

2003-01-01

140

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

NASA Astrophysics Data System (ADS)

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 erosion and deposition, and assessing the impact of fluid viscosity on infiltration rate. References cited: [1] McEwan et al. (2011) Science, 333, 740-743. [2] Malin and Edgett (2000) Science, 288, 2330-2335. [3] Reiss et al. (2004) JGR, doi:10.1029/2004JE002251 [4] Schon et al. (2009) Geology, 37, 207-210. [5] Chevrier et al. (2009) JGR, doi :10.1029/2009JE003376 [6] Conway et al. (2011) Icarus, 211, 443-457.

Conway, Susan; Gourronc, Marrine; Patel, Manish

2013-04-01

141

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...

142

Interactions between 'Bacillus thuringiensis subsp. 'israelensis' and Fathead Minnows, 'Pimephales promelas' Rafinesque, under Laboratory Conditions.  

National Technical Information Service (NTIS)

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. Mortality among fatheads exposed to 2.0 x 10 to t...

V. M. Snarski

1990-01-01

143

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)

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 the hydrate-bearing sand resulting from exposure to the mixed gas. Upon introduction of the mixed gas, the sample became less stiff and wave attenuation increased, indicating the presence of liquid water between mineral grains and hydrate. Slow dissociation of hydrate conducted in this experiment showed a range of hydrate stability conditions as the gas composition changed from dissociation and dilution of the previously injected nitrogen.

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

2013-12-01

144

Life cycle and host specificity of Amblyomma triste (Acari: Ixodidae) under laboratory conditions  

Microsoft Academic Search

We report biological data of two generations of Amblyomma triste in laboratory and compared the suitability of different host species. Infestations by larval and nymphal stages were performed\\u000a on guinea pigs (Cavia porcellus), chickens (Gallus gallus), rats (Rattus norvegicus), rabbits (Oryctolagus cuniculus), wild mice (Calomys callosus), dogs (Canis familiaris) and capybaras (Hydrochaeris hydrochaeris). Infestations by adult ticks were performed on

Marcelo B. Labruna; Eric Y. M. Fugisaki; Adriano Pinter; José Maurício B. Duarte; Matias J. P. Szabó

2003-01-01

145

Maturation, epitoky and regeneration in the polychaete Eunice siciliensis under field and laboratory conditions  

Microsoft Academic Search

In the gonochoric polychaetous annelid Eunice siciliensis Grube, germ cells only develop in the posterior segments of the worm; these segments subsequently differentiate into an epitokous portion separating at maturity from the infertile body part. As in the Pacific and Atlantic palolo worms, the epitokous portions die some hours after spawning. Laboratory investigations revealed that the anterior parts of spawned

D. K. Hofmann

1974-01-01

146

Laboratory study of static and dynamic compaction grouting in triaxial condition  

Microsoft Academic Search

This research paper is focused on the fundamental behaviour of applying static and dynamic compaction grouting techniques on completely decomposed granite (CDG) soils in Hong Kong. Using the modified triaxial apparatus and a novel pulse wave generator, laboratory tests were performed to identify the critical controllable factors of static and dynamic compaction grouting techniques in optimizing compaction effectiveness. The distinguishing

S. Y. Wang; D. H. Chan; K. C. Lam; S. K. A. Au

2011-01-01

147

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

Microsoft Academic Search

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 \\

Carmen Sánchez Oliveros; Laura Martín Aragón; Raquel Macias Jareño

2009-01-01

148

Experimental\\/Laboratory Study of Zeta and Streaming Potentials at In Situ Conditions  

Microsoft Academic Search

Streaming Potentials and zeta potentials were measured at equilibrium conditions, while at elevated temperatures of 23-200 degrees C and pressures of 20 MPa, on intact rock samples of Fontainebleau Sandstone, Berea Sandstone, and Westerly Granite. The techniques for achieving and measuring streaming potentials at equilibrium conditions, while at elevated temperatures and pressures is presented. The streaming potential coupling coefficient for

P. M. Reppert; F. D. Morgan

2003-01-01

149

Analyses of stress resistance under laboratory conditions constitute a suitable criterion for wine yeast selection  

Microsoft Academic Search

During wine production, yeast cells are affected by several conditions that are adverse to growth (oxidative, osmotic and ethanol stress among others) and they should detect and respond to these conditions, otherwise alcoholic fermentation can be negatively affected. In this work we have analyzed the fermentative behaviour of 14 commercial and non-commercial strains in several synthetic musts. According to the

Aurora Zuzuarregui

2004-01-01

150

Population growth of Pieris brassicae (L.) (Lepidoptera: Pieridae) on different cole crops under laboratory conditions  

Microsoft Academic Search

The effect of different host plants including cabbage, cauliflower, mustard, radish, and broccoli on biological parameters\\u000a of Pieris brassicae (L.) was studied in the laboratory at 28°C, 65 ± 5% RH and 12L:12D photoperiod. Duration of each life stage, longevity, the\\u000a intrinsic rate of natural increase (r\\u000a m), net reproductive rate (R\\u000a 0), mean generation time (T), doubling time (DT), and finite

Fazil Hasan; M. Shafiq Ansari

2011-01-01

151

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

PubMed

The life history of the fruit fly (Drosophila melanogaster) is well understood, but fitness components are rarely measured by following single individuals over their lifetime, thereby limiting insights into lifetime reproductive success, reproductive senescence and post-reproductive lifespan. Moreover, most studies have examined long-established laboratory strains rather than freshly caught individuals and may thus be confounded by adaptation to laboratory culture, inbreeding or mutation accumulation. Here, we have followed the life histories of individual females from three recently caught, non-laboratory-adapted wild populations of D. melanogaster. Populations varied in a number of life-history traits, including ovariole number, fecundity, hatchability and lifespan. To describe individual patterns of age-specific fecundity, we developed a new model that allowed us to distinguish four phases during a female's life: a phase of reproductive maturation, followed by a period of linear and then exponential decline in fecundity and, finally, a post-ovipository period. Individual females exhibited clear-cut fecundity peaks, which contrasts with previous analyses, and post-peak levels of fecundity declined independently of how long females lived. Notably, females had a pronounced post-reproductive lifespan, which on average made up 40% of total lifespan. Post-reproductive lifespan did not differ among populations and was not correlated with reproductive fitness components, supporting the hypothesis that this period is a highly variable, random 'add-on' at the end of reproductive life rather than a correlate of selection on reproductive fitness. Most life-history traits were positively correlated, a pattern that might be due to genotype by environment interactions when wild flies are brought into a novel laboratory environment but that is unlikely explained by inbreeding or positive mutational covariance caused by mutation accumulation. PMID:23675912

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

2013-07-01

152

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

NASA Astrophysics Data System (ADS)

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.

Irving, Paul W.; Sayre, Eleanor C.

2014-06-01

153

Laboratory investigations of a low-swirl injector with H 2 and CH 4 at gas turbine conditions  

Microsoft Academic Search

Laboratory experiments were conducted at gas turbine and atmospheric conditions (0.101

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

2009-01-01

154

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

Microsoft Academic Search

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?gkg?1 of imidacloprid or 500?gkg?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

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

2004-01-01

155

Subchronic oral toxicity of microcystin in common carp ( Cyprinus carpio L.) exposed to Microcystis under laboratory conditions  

Microsoft Academic Search

The subchronic oral toxicity of microcystin in common carp (Cyprinus carpio L.) was investigated in this study. The fish (mean body weight of 322±36g, n=10) were orally exposed to Microcystis by feeding with bloom scum at a dose of 50?g microcystins\\/kg body weight under laboratory conditions for 28 days. Growth assay results showed that microcystin could completely inhibit the growth

Xiao-Yu Li; Ik-Kyo Chung; Jung-In Kim; Jin-Ae Lee

2004-01-01

156

Study of the efficacy of a Wheaton coated bottle with permethrin and deltamethrin in laboratory conditions and a WHO impregnated paper with bendiocarb in field conditions  

PubMed Central

Objective To determine the efficacy of WHO impregnated paper and CDC coated bottle based on number of storage days and number of times of consecutive use, in the assessment of insecticide vector susceptibility tests in laboratory and field conditions. Methods Larvae and pupae of Anopheles gambiae s.l. mosquitoes were collected from the breeding sites in Seme-Kpodji and Cotonou districts in Southern Benin in April 2013 during the first rainy season. Anopheles gambiae s.l. mosquitoes were also collected from the breeding sites in Parakou district in Northern Benin in May 2013 at the beginning of the rainy season. Susceptibility tests were done using impregnated paper with bendiocarb (0.1%) following WHO protocol and stock solutions of permethrin (21.5 µg per bottle) and deltamethrin (12.5 µg per bottle) following CDC protocol on unfed female mosquitoes aged 2–5 days old. These bioassays were repeated a certain number of times. The temperature and relative humidity were monitored and recorded during the susceptibility tests. Results This study showed that a WHO impregnated paper with bendiocarb could be used four times during four consecutive days in field conditions. Regarding a Wheaton coated bottle with permethrin or deltamethrin, they could be used at least three times during four consecutive days in laboratory conditions. Conclusions The day storage and the number of times that a WHO impregnated paper and a CDC coated bottle maintained their efficacy are useful in the assessment of insecticide vectors susceptibility tests.

Aizoun, Nazaire; Azondekon, Roseric; Aikpon, Rock; Gnanguenon, Virgile; Osse, Razaki; Asidi, Alex; Akogbeto, Martin

2014-01-01

157

Maintenance of previously uncultured freshwater archaea from anoxic waters under laboratory conditions  

Microsoft Academic Search

Culture conditions for the maintenance of previously uncultured members of the Archaea thriving in anoxic water layers of stratified freshwater lakes are described. The proposed enrichment conditions, based on\\u000a the use of defined medium composition and the maintenance of anoxia, have been proven effective for the maintenance of the\\u000a archaeal community with virtually no changes over time for periods up

Anna Plasencia; Lluís Bañeras; Marc Llirós; Emilio O. Casamayor; Carles Borrego

2011-01-01

158

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

USGS Publications Warehouse

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

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

2010-01-01

159

Improbability of void growth in aluminum via dislocation nucleation under typical laboratory conditions.  

PubMed

The rate at which dislocations nucleate from spherical voids subjected to shear loading is predicted from atomistic simulation. By employing the latest version of the finite temperature string method, a variational transition state theory approach can be utilized, enabling atomistic predictions at ordinary laboratory time scales, loads, and temperatures. The simulation results, in conjunction with a continuum model, show that the deformation and growth of voids in Al are not likely to occur via dislocation nucleation under typical loadings regardless of void size. PMID:22400757

Nguyen, L D; Warner, D H

2012-01-20

160

Properties of slate mining wastes incubated with grape marc compost under laboratory conditions.  

PubMed

The effect of the addition of spent grape marc compost (GMC) and vermicompost (GMV) as amendments to slate mining wastes was evaluated in a laboratory incubation experiment. Mixtures of slate processing fines (SPF), with three doses of each amendment (4%, 8% and 16% compost, dry weight), plus a control were incubated at 25 degrees C in the laboratory for 90 days. The changes in the chemical and biological properties of the mixtures (pH, total C, total N, inorganic N, available nutrients, microbial biomass carbon and dehydrogenase activity) were investigated during the incubation period, and once it was finished, the phytotoxicity of the mixtures was determined by the germination of Lolium multiflorum Lam. seeds. The addition of the amendments significantly increased the nutrient concentrations of the SPF and enhanced biological activity by increasing microbial biomass and enzymatic activity. Results improved with higher doses; within the composts, GMV showed a better performance than GMC. These results prove the suitability of grape marc-derived amendments for the biochemical amelioration of mining wastes, and highlight the benefits of organic amendment in restoration projects. PMID:18706797

Paradelo, Remigio; Moldes, Ana Belén; Barral, María Teresa

2009-02-01

161

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

NASA Technical Reports Server (NTRS)

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

Steffes, Paul G.

1989-01-01

162

Response of the green alga Oophila sp., a salamander endosymbiont, to a PSII-inhibitor under laboratory conditions.  

PubMed

In a rare example of autotroph-vertebrate endosymbiosis, eggs of the yellow-spotted salamander (Ambystoma maculatum) are colonized by a green alga (Oophila sp.) that significantly enhances salamander development. Previous studies have demonstrated the potential for impacts to the salamander embryo when growth of the algae is impaired by exposure to herbicides. To further investigate this relationship, the authors characterized the response of the symbiotic algae (Oophila sp.) alone to the photosystem II (PSII) inhibitor atrazine under controlled laboratory conditions. After extraction of the alga from A. maculatum eggs and optimization of culturing conditions, 4 toxicity assays (96?h each) were conducted. Recovery of the algal population was also assessed after a further 96?h in untreated media. Average median effective concentration (EC50) values of 123?µg?L(-1) (PSII yield), 169?µg?L(-1) (optical density), and 299?µg?L(-1) (growth rate) were obtained after the 96-h exposure. Full recovery of exposed algal populations after 96?h in untreated media was observed for all endpoints, except for optical density at the greatest concentration tested (300?µg?L(-1) ). Our results show that, under laboratory conditions, Oophila sp. is generally less sensitive to atrazine than standard test species. Although conditions of growth in standard toxicity tests are not identical to those in the natural environment, these results provide an understanding of the tolerance of this alga to PSII inhibitors as compared with other species. Environ Toxicol Chem 2014;33:1858-1864. © 2014 SETAC. PMID:24782078

Baxter, Leilan; Brain, Richard; Rodriguez-Gil, Jose Luis; Hosmer, Alan; Solomon, Keith; Hanson, Mark

2014-08-01

163

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

NASA Astrophysics Data System (ADS)

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

Pokharel, A. K.; Obrist, D.

2009-12-01

164

Laboratory Measurements of Microwave Properties of Ammonia Under Deep Jovian Atmospheric Conditions  

NASA Astrophysics Data System (ADS)

Over 500 lab measurements of the 1.5-6 GHz properties of ammonia have been made under simulated deep Jovian atmospheric conditions (pressures up to 100 bars and temperatures upto 450 K) using a high-pressure measurement system built at Georgia Tech.

Devaraj, K.; Steffes, P. G.

2010-03-01

165

Laboratory study on the survival of water hyacinth under several conditions of heavy metal concentrations  

Microsoft Academic Search

To study the survival and behaviour of water hyacinth [Eichhornia crassipes (Mart.) Solms] under varying conditions of heavy metal concentrations, groups of the plants were grown in different media (distilled water, Nile water, wastewater and different concentrations of heavy metals). Simultaneously, blank experiments were carried out for comparison. Visual changes in the plants observed during each experiment were noted. The

M. E Soltan; M. N Rashed

2003-01-01

166

The Life Cycle of the Root Borer, Oryctes agamemnon , Under Laboratory Conditions  

Microsoft Academic Search

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

Rasmi Soltani; Ikbel Chaieb; Med Habib Ben Hamouda

2008-01-01

167

Mobilization and speciation of arsenic from hydrothermally altered rock in laboratory column experiments under ambient conditions  

Microsoft Academic Search

This paper describes the mobilization and speciation of As found in hydrothermally altered rock under oxic column conditions. The altered rock sample was obtained from a tunnel project located in the Nakakoshi area of Hokkaido, Japan, whose geology is represented by slate, shale and sandstone. This area has undergone silicification, pyritization and argillic alteration resulting in As-enrichment of the rock.

Carlito Baltazar Tabelin; Toshifumi Igarashi; Ryohei Takahashi

168

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

PubMed

Between December 2011 and March 2012, the reproductive characteristics of Microtus fortis reared in the laboratory at different population densities were assessed. In all, 258 male and female voles were randomly divided into 4 groups and reared at densities of 2, 4, 6, and 8 animals per cage (sex ratio: 1:1). The results showed that the pregnancy rate (?2 = 21.671, df = 3, P < 0.001) and first farrowing interval (F = 12.355, df = 3, P < 0.001) were significantly different among the different population density groups, but the mean litter size (mean ± SD) was not (F = 2.669, df = 3, P > 0.05). In particular, the reproductive index and sex hormone levels showed a significant difference among the different density groups studied. PMID:24873906

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

2014-06-01

169

Efficacy of pesticide mixtures against the western flower thrips (Thysanoptera: Thripidae) under laboratory and greenhouse conditions.  

PubMed

Western flower thrips, Frankliniella occidentalis Pergande is a commonly encountered and economically important insect pest of greenhouses. Greenhouse producers typically apply pesticides as mixtures to mitigate western flower thrips populations; however, there is limited information available on the compatibility and efficacy of commonly used pesticide mixtures. This study assessed nine binary and three tertiary pesticide mixtures used in greenhouses which included pesticides containing abamectin, acephate, azadirachtin, bifenazate, bifenthrin, fenpropathrin, imidacloprid, novaluron, pymetrozine, and spinosad. Compatibility was determined for the binary pesticide mixtures using jar tests. In addition, the binary mixtures were applied to nine horticultural plant species to determine phytotoxicity based on visual appearance assessed 7 d after treatment. Bean-dip bioassays were performed in a laboratory using green bean (Phaseolus vulgaris L.) to determine LC50 values for each individual pesticide and the mixtures to establish whether the mixtures were synergistic, antagonistic, or there was no effect. The mortality of western flower thrips was assessed after 24 h, and LC50 values were calculated. Furthermore, semifield bioassays were performed in greenhouses for binary and tertiary mixtures to evaluate the efficacy (based on percent mortality) of the pesticide mixtures against western flower thrips. Results indicated that all binary mixtures were visibly compatible, and not phytotoxic to any of the plant species evaluated. Combination index calculations based on laboratory results indicated most of the binary mixtures were synergistic; however, the mixture containing spinosad + bifenazate appeared to be antagonistic against western flower thrips. The semifield bioassays demonstrated significantly reduced efficacy associated with mixtures containing azadirachtin, however, all binary mixtures provided approximately 80% western flower thrips mortality. PMID:23448038

Willmott, Amy L; Cloyd, Raymond A; Zhu, Kun Yan

2013-02-01

170

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

PubMed

Airborne contaminants generated inside laboratory fume hoods during use leak into the breathing zone of the user. Concentration of the leakage is unknown and variable depending on laboratory design, work practices, arrangement of internal apparatus, face velocity, and sash height. Surrogate tracer gas tests have been developed using sulfur hexafluoride (SF6) and a manikin to estimate leakage. This study presents results of hood leakage tests using SF6 with a manikin and then a live operator performing a phenol:chloroform (P:C) extraction. Four hoods were tested in each of three institutions during normal work hours with the lab occupied. The purpose of the study was to determine leakage concentrations for the SF6-manikin with effects of sash height, hood contents as found and after being cleaned out, face velocity, and the actual P:C and SF6 exposure concentrations of the user during work. Results indicate P:C was not detectable in the breathing zone of the 12 operators (< 0.1 ppm) at their selected operating sash heights (7 to 15 inches). Simultaneous SF6 concentrations were also minimal (average 0.06 ppm). Average leakage was 0.02 percent for SF6 and less than 2 percent based on chloroform concentrations measured in the breathing zone of the operator and inside the hood. SF6 percent leakage was greater when sash height was above the breathing zone of the manikin (average 2.09 percent) and lower leakage (average 0.02 percent) when below the breathing zone (26 inches or less). Average face velocity did not appear to be a predictor of average hood leakage. Cleaning out the hoods did not reduce leakage in most tests. The data from this study shows that when providing training on proper work practices for lab hood use, lowering the sash should be stressed as being the major factor in reducing hood leakage. PMID:10675979

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

2000-02-01

171

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

PubMed

Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) is an important plant virus vector in grapevine crops in Brazil and other countries. The mealybug grows in roots and leaves of the grapes. Entomopathogenic nematodes (EPNs) are efficient control agents against insects associated to the soil and could be applied with the same equipment used for chemical insecticides. The aim of this study was to select effective EPNs for controlling P. citri females in laboratory conditions (25±1°C, UR 60±10%). We tested 17 native [Steinernema rarum (6 strains), Steinernema glaseri, Steinernema feltiae, Steinernema riobrave, Steinernema sp., Heterorhabditis bacteriophora (7 strains)] and only one exotic strain (Steinernema carpocapsae ALL). The bioassays were done on Petri dishes infested with females of P. citri, which were sprayed with EPNs juveniles. The strain with larger pathogenicity and virulence in laboratory was H. bacteriophora RS33 (from 69.0% to 92.2% of mortality), native of Rio Grande do Sul. PMID:23458234

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

2013-07-01

172

Microbial characteristics of sandy soils exposed to diazinon under laboratory conditions  

Microsoft Academic Search

Changes in microbiological characteristics in response to diazinon, applied at three different dosages of 7, 35 and 700 mg kg?1 soil, were studied in pots filled with sandy soils of different texture. The insecticide dosages corresponded to the maximum\\u000a predicted environmental concentration (PEC) in field conditions and five or hundred times this rate, respectively. To ascertain\\u000a these changes, activities of selected soil

M. Cyco?; Z. Piotrowska-Seget; J. Kozdrój

2010-01-01

173

Laboratory evaluation of microwave absorption properties under simulated conditions for planetary atmospheres  

NASA Technical Reports Server (NTRS)

The microwave absorbing properties of gaseous sulfuric acid (H2SO4) under Venus atmospheric conditions are investigated. The results are applied to measurements from Mariner 5, Mariner 10, and Pioneer/Venus Radio Occultation experiments, to determine abundancies of gaseous sulfuric acid in the Venus atmosphere. The microwave properties of the vapors accompanying liquid H2SO4 are studied to estimate the vapor pressure in an atmospheric model.

Steffes, P. G.

1984-01-01

174

Removal and degradation characteristics of quinolone antibiotics in laboratory-scale activated sludge reactors under aerobic, nitrifying and anoxic conditions.  

PubMed

This work describes the removal of 6 quinolone antibiotics from wastewaters under different redox conditions (aerobic, nitrifying and anoxic) through batch experiments in laboratory scale activated sludge reactors using mixed liquor from a membrane bioreactor pilot plant (MBR). The main removal pathways for antibiotics from wastewaters involved in each treatment are described. Mass balances indicated that sorption on sludge played a dominating role in the elimination of antibiotics. Sorption potential depended on the redox conditions, being lower in nitrifying (Kd, 414-876 L kg(-1)) and anoxic (Kd, 471-930 L kg(-1)) sludge in comparison with aerobic sludge (Kd, 534-1137 L kg(-1)). Kd was higher for piperazinylic quinolones. Redox conditions also influenced biodegradation, a secondary pathway, which followed first-order kinetics with degradation rates constants ranging from 1.8·10(-3) to 8.2·10(-3) h(-1). Biodegradation rates under anoxic conditions were negligible. The experimental results have also demonstrated much higher removal efficiency by biodegradation (36.2-60.0%) under nitrifying conditions in comparison with aerobic conditions (14.9-43.8%). The addition of allylthiourea, an ammonia monooxygenase inhibitor, inhibited nitrification completely and reduced significantly the biodegradation of target antibiotics (16.5-29.3%). The residual biodegradation in the presence of allylthiourea may be due to the activity of heterotrophs in the enriched nitrifier culture. The removal of the selected antibiotics under the studied redox conditions depended significantly on the bacteria composition of the sludge. These results suggest that despite the known persistence of this group of antibiotics it is possible to enhance their degradation using nitrifying conditions, which at adequate working conditions as high SRT, typical in MBR, become a promising alternative for improving quinolones removal from environment. PMID:23507246

Dorival-García, N; Zafra-Gómez, A; Navalón, A; González-López, J; Hontoria, E; Vílchez, J L

2013-05-15

175

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

USGS Publications Warehouse

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

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

2007-01-01

176

Estimating surface water risk at Oak Ridge National Laboratory: Effects of site conditions on modeling results  

SciTech Connect

Multiple source term and groundwater modeling runs were executed to estimate surface water {sup 90}Sr concentrations resulting from leaching of sludges in five 180,000 gallon Gunite{trademark} tanks at Oak Ridge National Laboratory. Four release scenarios were analyzed: (1) leaching of unstabilized sludge with immediate tank failure; (2) leaching of unstabilized sludge with delayed tank failure due to chemical degradation; (3) leaching of stabilized sludge with immediate tank failure; and (4) leaching of residual contamination out of the shells of empty tanks. Source terms and concentrations of {sup 90}Sr in the stream directly downgradient of the tanks were calculated under these release scenarios. The following conclusions were drawn from the results of the modeling: (1) small changes in soil path length resulted in relatively large changes in the modeled {sup 90}Sr concentrations in the stream; (2) there was a linear relationship between the amount of sludge remaining in a tank and the peak concentration of {sup 90}Sr in the stream; (3) there was a linear relationship between the cumulative {sup 90}Sr release from a tank and the peak concentration of {sup 90}Sr in the stream; (4) sludge stabilization resulted in significantly reduced peak concentrations of {sup 90}Sr in the stream; and (5) although radioactive decay of {sup 90}Sr during the period of tank degradation resulted in incrementally lower peak {sup 90}Sr concentrations in surface water than under the immediate tank failure scenarios these concentrations were equivalent under the two scenarios after about 90 years.

Curtis, A.H. III

1996-08-01

177

The efficacy of four avermectins on the synanthropic mite Lepidoglyphus destructor under laboratory conditions.  

PubMed

The effect of four avermectins on the population growth of pest mite Lepidoglyphus destructor was tested in laboratory experiments. The avermectins (abamectin, doramectin, emamectin-benzoate and ivermectin) of analytical purity were incorporated into an experimental diet at the same molar concentrations, ranging from 0.16 to 8 nmol/3 g of diet. Using an initial population of 50 mites, the population growth was recorded after 21 days at 85 % relative humidity and 25 °C; 12 repeats were performed per avermectin concentration and control. The diets containing the avermectins successfully suppressed the population growth of L. destructor. The EC(50) recalculated to ng of substance per g of diet showed different suppressive effects of the avermectins: doramectin (181 ng/g diet), abamectin (299 ng/g diet), emamectin-benzoate (812 ng/g diet) and ivermectin (992 ng/g diet). Of the tested avermectins, abamectin is registered for the control of phytophagous mites and ivermectin against parasitic mites, i.e., Psoroptes ovis. Although emamectin-benzoate and ivermectin were less effective on L. destructor, all of the tested avermectins are highly suitable compounds for the control of synanthropic mites. PMID:22527833

Erban, Tomas; Rybansky, Jakub; Hubert, Jan

2012-09-01

178

How to improve housing conditions of laboratory animals: the possibilities of environmental refinement.  

PubMed

Housing systems for captive animals have often been designed on the basis of economic and ergonomic considerations, such as equipment, costs, space, workload, ability to observe the animals and to maintain a certain degree of hygiene, with little or no consideration for animal welfare. Environmental refinement can be defined as any modification in the environment of captive animals that seeks to enhance the physical and psychological well-being of the animals by providing stimuli which meet the animals' species-specific needs. This article provides an overview of environmental factors that influence the well-being of captive animals with specific reference to the needs of the most common laboratory species. It is important to evaluate environmental refinement in terms of the benefit to the animal, by assessing the use of and preference for certain enrichment, the effect on behaviour, and the performance of species-typical behaviour on physiological parameters. It is also necessary to evaluate the impact of refinement on scientific outcome, including whether and how statistical power is affected. Communication and team work between animal welfare scientists, animal research scientists, institutional animal welfare officers, veterinarians and animal ethics committees, animal facility management and personnel, are essential for success. PMID:23127868

Baumans, V; Van Loo, P L P

2013-01-01

179

Induction to maturation of the sea urchin Paracentrotus lividus (Lamarck, 1816) under laboratory conditions.  

PubMed

Laboratory experiments were carried out over two different periods, with the aim of investigating and utilizing the induction to gonadal maturation of the sea urchin Paracentrotus lividus. The final objective was to obtain viable gametes outside the period of natural spawning in the environment; which would allow the utilization of ecotoxicological bioassays with sea urchin larvae at any time of the year. The experiment consisted of maintaining some sea urchins in tanks and providing them with a natural photoperiod, unlimited food and a constant temperature of 20 degrees C. During days 0, 30, 60 and 90, gonads from 15 of these sea urchins were compared with those collected simultaneously in the natural environment. The gametes obtained were used to carry out fecundations, in order to check their viability. The final results obtained were clearly influenced by the gonadal state of the sea urchins at the initial stage of the experiment. The best results were obtained within a time period of 60 days and when the initial gonad index was low. PMID:20088209

Garmendia, Joxe Mikel; Menchaca, Iratxe; Belzunce, María Jesús; Franco, Javier; Revilla, Marta

2009-12-01

180

Juvenile development of Callinectes danae Smith, 1869 (Crustacea, Decapoda, Brachyura, Portunidae) under laboratory conditions.  

PubMed

The juvenile development of Callinectes danae was investigated from megalopae obtained in neuston samples at Ubatuba, São Paulo, Brazil. The individuals were raised in the laboratory under constant temperature (25 ± 1°C), filtered sea water from the collection location (35‰), and natural photoperiod. Newly hatched Artemia sp. nauplii were offered as food on a daily basis and ornamental-fish food was also provided for the juveniles from the 4th stage on. Twelve stages of the juvenile phase were obtained. The main morphological features that allowed recognition of the first juvenile stage were drawn and described. All the subsequent stages obtained were examined and measured, and the main changes in relation to the first stage were recorded. Sexual dimorphism becomes apparent from the fourth juvenile stage onwards. Some appendages and morphological features proved to be of great importance in the identification of species, including the number of segments of the antennal flagellum and the number of setae on the maxilla and on the 1st, 2nd and 3rd maxillipeds. These can probably be used for future comparisons and species identifications. PMID:24676164

Bolla, Eduardo A; Fransozo, Vivian; Negreiros-Fransozo, Maria Lucia

2014-03-01

181

Parasitism of Tuta absoluta (Lepidoptera, Gelechiidae) by Pseudapanteles dignus (Hymenoptera, Braconidae) under laboratory conditions.  

PubMed

Laboratory studies were conducted to measure selected life history traits and the functional response of the parasitoid Pseudapanteles dignus (Muesebeck), a major enemy of Tuta absoluta (Meyrick) in tomato crops in South America. Newly mated P. dignus females were individually exposed to 10 host larvae in mines for 24 h. We determined developmental time from egg to pupal formation and pupal stage duration, female adult life span, fecundity, reproductive period, daily parasitism rate, and sex ratio of offspring. For the functional response experiment, treatments consisted of six host densities: 3, 5, 7, 10, 15, 20, or 30 larvae. The number and proportion of parasitized hosts were calculated for each density. The shape of the functional response curve was analyzed by logistic regression. P. dignus females attacked hosts daily, exhibiting modest lifetime fecundity (approximately 32 parasitized hosts per female) and a female-biased offspring sex ratio. Female adult life span was 36 d. P. dignus showed a type I functional response within the range of host densities tested. We observed that females detect and parasitize the host within a wide range of densities, including low densities. The functional response curve reached an asymptote at a mean density of six hosts per day and seemed not to be egg-limited. Percent parasitism was approximately 30%. The ecological implications of the results in relation to the potential of P. dignus for the biological control of T. absoluta in tomato are discussed. PMID:17716480

Luna, María G; Sánchez, Norma E; Pereyra, Patricia C

2007-08-01

182

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

NASA Astrophysics Data System (ADS)

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

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

2011-08-01

183

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

USGS Publications Warehouse

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

Johnson, James H.

2003-01-01

184

Complete larval development of the Brachyuran crab (Epixanthus Frontalis H. Milne Edwards, 1834) (Crustacea, Decapoda, Eriphioidea, Oziidae) under laboratory conditions.  

PubMed

The complete larval development of the oziid crab Epixanthus frontalis (H. Milne Edwards, 1834) hatched from ovigerous specimens collected from Saso Island, southern Red Sea, was obtained under laboratory conditions. Four zoeae, one additional zoea and a megalopa were obtained and these are described and illustrated in detail for the first time. Larvae of this species can be differentiated from those of other oziid species based on a combination of characters such as the number of aesthetascs and setae of the antennule, and the coxal and basial setal numbers and patterns of the maxilla and maxillule. PMID:24943598

Al-Aidaroos, Ali M; Al-Haj, Ahmed E; Kumar, A A J

2014-01-01

185

Laboratory measurements of the 7. 5-9. 38-mm absorption of gaseous ammonia (NH3) under simulated Jovian conditions  

SciTech Connect

An attempt is made to infer the abundance and distribution of ammonia from RF emission measurements more accurately than heretofore, on the basis of the results of laboratory measurements for the mm-wave opacity of gaseous ammonia under simulated Jovian atmosphere conditions. The measurements were conducted at various frequencies in the 32-40 GHz range at 2 atm and 203 K; the atmospheric mixture was 88.34 percent H2, 9.81 percent He, and 1.85 percent NH3. Experimental results are found to be readily modeled by the Gross (1955) line-shape factor, rather than that of Van Vleck and Weisskopf (1945). 15 refs.

Joiner, J.; Steffes, P.G.; Jenkins, J.M. (Georgia Institute of Technology, Atlanta (USA))

1989-10-01

186

Laboratory measurements of the 7.5-9.38-mm absorption of gaseous ammonia (NH3) under simulated Jovian conditions  

NASA Technical Reports Server (NTRS)

An attempt is made to infer the abundance and distribution of ammonia from RF emission measurements more accurately than heretofore, on the basis of the results of laboratory measurements for the mm-wave opacity of gaseous ammonia under simulated Jovian atmosphere conditions. The measurements were conducted at various frequencies in the 32-40 GHz range at 2 atm and 203 K; the atmospheric mixture was 88.34 percent H2, 9.81 percent He, and 1.85 percent NH3. Experimental results are found to be readily modeled by the Gross (1955) line-shape factor, rather than that of Van Vleck and Weisskopf (1945).

Joiner, Joanna; Steffes, Paul G.; Jenkins, Jon M.

1989-01-01

187

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

USGS Publications Warehouse

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

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

1988-01-01

188

Laboratory algal bioassays using PAM fluorometry: effects of test conditions on the determination of herbicide and field sample toxicity.  

PubMed

Pulse Amplitude Modulation (PAM) fluorometry, based on chlorophyll a fluorescence, is a frequently used technique in algal bioassays to assess toxicity of single compounds or complex field samples. Several test conditions can influence the test results, and because a standardized test protocol is currently lacking, linking the results of different studies is difficult. Therefore, the aim of the present study was to gain insight into the effects of test conditions of laboratory algal bioassays using PAM fluorometry on the outcome of toxicity tests. To this purpose, we described the results from several pilot studies on test development in which information is provided on the effects of the main test factors during the pretest phase, the test preparation, the exposure period, and the actual measurement. The experiments were focused on individual herbicides and complex field samples and included the effects of culturing conditions, cell density, solvent concentration, exposure time, and the presence of actinic light. Several of these test conditions were found to influence the outcome of the toxicity test, and the presented information provides important background information for the interpretation of toxicity results and describes which test conditions should be taken into account when using an algal bioassay with PAM fluorometry. Finally, the application of PAM fluorometry in algal toxicity testing is discussed. PMID:24478234

Sjollema, Sascha B; van Beusekom, Sebastiaan A M; van der Geest, Harm G; Booij, Petra; de Zwart, Dick; Vethaak, A Dick; Admiraal, Wim

2014-05-01

189

Role of drainage conditions in deformation and fracture of porous rocks under triaxial compression in the laboratory  

NASA Astrophysics Data System (ADS)

In order to investigate the role of drainage conditions in deformation and fracture behaviors of porous rocks, the authors carried out a series of rock fracture tests under triaxial compression in the laboratory. The detailed space-time distribution of acoustic emission due to microcracking was used to examine pre-failure damage and failure behavior in Berea sandstone, which has a porosity of ?20% and a permeability of ?100 mD. The pore pressures or flow rates at the ends of the test sample were precisely controlled to simulate different drainage conditions. Experimental results indicate that drainage conditions play a governing role in deformation and fracture. The well-established dilatancy-hardening effect can be greatly suppressed by dilatancy-driven fluid flowing under good drainage conditions. Fast diffusion of pore pressure leads to a significant reduction in rock strength and stabilization of the dynamic rupture process. Furthermore, good drainage conditions have the potential to enlarge the nucleation dimension and duration, thereby improving the predictability of the final catastrophic failure. In addition, compaction bands, which were observed in porous rocks under higher confining pressure, were also observed at low confining pressure (corresponding to a depth of ?1 km) in undrained tests. These results are particularly important for research fields in which fluid migration or pore pressure diffusion is expected to play a role, such as hydrocarbon reservoirs, enhanced geothermal systems, geological storage of CO2.

Lei, Xinglin; Tamagawa, Tetsuya; Tezuka, Kazuhiko; Takahashi, Manabu

2011-12-01

190

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

SciTech Connect

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

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

1983-04-01

191

Optimal conditions for high current proton irradiations at the university of Wisconsin's ion beam laboratory  

NASA Astrophysics Data System (ADS)

The National Electrostatics Corporation's (NEC) Toroidal Volume Ion Source (TORVIS) source is known for exceptionally high proton currents with minimal service downtime as compared to traditional sputter sources. It has been possible to obtain over 150?A of proton current from the source, with over 70?A on the target stage. However, beam fluxes above ~1×1017/m2-s may have many undesirable effects, especially for insulators. This may include high temperature gradients at the surface, sputtering, surface discharge, cracking or even disintegration of the sample. A series of experiments were conducted to examine the role of high current fluxes in a suite of ceramics and insulating materials. Results will show the optimal proton irradiation conditions and target mounting strategies needed to minimize unwanted macro-scale damage, while developing a procedure for conducting preliminary radiation experiments.

Wetteland, C. J.; Field, K. G.; Eiden, T. J.; Gerczak, T. J.; Maier, B. R.; Albakri, O.; Sridharan, K.; Allen, T. R.

2013-04-01

192

Aggressive interactions between Solenopsis invicta and Linepithema humile (Hymenoptera: Formicidae) under laboratory conditions.  

PubMed

The Argentine ant, Linepithema humile (Mayr), and the red imported fire ant, Solenopsis invicta Buren, are natural agonists in their country of origin. Since the first report of L. humile in California in 1907 its range expanded statewide, displacing native ant species wherever it spread. Since the discovery of established populations of S. invicta in southern California in 1998, it has been restricted to discrete areas of southern California. However, as these discrete populations expand, they are encountering large populations of L. humile, which are effective competitors for available resources and are particularly aggressive in their encounters with other ant species such as S. invicta. Most Dolichoderine ants such as L. humile do not prefer to forage on baits made with defatted corn grit and soybean oil typically used in red imported fire ant control programs. Applications of these baits in areas where distributions of these species overlap might selectively affect populations of S. invicta and give L. humile a competitive advantage. Three laboratory experiments were conducted to determine the competitive outcomes between S. invicta pitted against L. humile: 1) agonistic behavior of workers in small arenas, 2) colony interactions with different population ratios, and 3) the effects of pyriproxyfen on the competitiveness of S. invicta against L. humile. Populations of S. invicta consisting of major workers killed more L. humile than did minors or a mixture of majors and minors. When paired against L. humile colonies consisting of 1,100 workers, colonies consisting of 38 S. invicta workers were easily defeated by L. humile. Colonies consisting of 450 S. invicta workers plugged their nest entrances, but they were ultimately defeated by L. humile after 13 d. The S. invicta colonies consisting of 1,100 workers took control of the bridge connecting the colonies, invaded the L. humile colony, killed the Argentine ant queens, and removed their brood. Pyriproxyfen-treated fire ant workers took significantly longer to chase the Argentine ants from a connecting bridge than did untreated fire ants. Thus, fire ant baits may have long-term effects on intercolonial aggression between S. invicta and L. humile, especially when Argentine ant populations are high in the summer. PMID:17370822

Kabashima, J N; Greenberg, L; Rust, M K; Paine, T D

2007-02-01

193

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

NASA Astrophysics Data System (ADS)

Preliminary investigations suggest biological geotextiles could be an effective and inexpensive soil conservation method, with enormous global potential. Biological geotextiles are a possible temporary alternative for vegetation cover and can offer immediate soil protection. However, limited data are available on the erosion-reducing effects of biological geotextiles. Therefore, the objective of this study is to evaluate the effectiveness of selected types of biological geotextile in reducing runoff and soil loss under controlled laboratory conditions and under field conditions reflecting different environments (i.e. continental, temperate and tropical). In laboratory experiments, interrill runoff, interrill erosion and concentrated flow erosion were simulated using various rainfall intensities, flow shear stresses and slope gradients. Field plot data on the effects of biological geotextiles on sheet and rill erosion were collected in several countries under natural rainfall (U.K., Hungary, Lithuania, South Africa, Brazil, China and Thailand). The laboratory experiments indicate that all tested biological geotextiles were effective in reducing interrill runoff (on average 59% of the value for bare soil) and interrill erosion rates (on average 16% of the value for bare soil). Since simulated concentrated flow discharge sometimes flowed below the geotextiles, the effectiveness in reducing concentrated flow erosion was significantly less (on average 59% of the value for bare soil). On field plots, where both interrill and rill erosion occur, all tested geotextiles reduced runoff depth by a mean of 54% of the control value for bare soil and in some cases, runoff depth increased compared to bare soil surfaces, which can be attributed to the impermeable and hydrophobic characteristics of some biological geotextiles. In the field, soil loss rates due to interrill and rill erosion were reduced by a mean of 21% of the value of bare soil by biological geotextiles. This study demonstrates that data from controlled interrill experiments in the laboratory correspond well to those obtained from field plots. Hence, interrill experiments in the laboratory allow one to predict the hydrological and erosion response of geotextiles on larger field plots. According to the field data, Rice straw geotextiles are the most effective geotextiles in reducing relative runoff and soil loss rates. No impact of plot length on the runoff and soil loss reduction by biological geotextiles was observed.

Smets, T.

2009-04-01

194

Placement of the radiochemical processing plant at Oak Ridge National Laboratory into a safe standby condition  

SciTech Connect

Extensive upgrade, cleanup, and decontamination efforts are being conducted for appropriate areas in the Radiochemical Processing Plant (RPP) with the goal of achieving ''safe standby'' condition by the end of FY 1989. The ventilation system must maintain containment; thus, it is being upgraded via demolition and replacement of marginally adequate ductwork, fans, and control systems. Areas that are being decontaminated and stripped of various services (e.g., piping, ductwork, and process tanks) include hot cells, makeup rooms, and pipe tunnels. Operating equipment that is being decontaminated includes glove boxes and hoods. Replacement of the ventilation system and removal of equipment from pipe tunnels, cells, and makeup rooms are accomplished by contact labor by workers using proper attire, safety rules, and shielding. Removal of contaminated ductwork and piping is conducted with containment enclosures that are strategically located at breakpoints, and methods of separation are chosen to conform with health physics requirements. The methods of cutting contaminated piping and ductwork include portable reciprocating saws, pipe cutters, burning, and plasma torch. Specially designed containment enclosures will be used to prevent the spread of radioactive contamination while maintaining adequate ventilation. 6 figs.

Holladay, D.W.; Bopp, C.D.; Farmer, A.J.; Johnson, J.K.; Miller, C.H.; Powers, B.A.; Collins, E.D.

1986-01-01

195

Heterogeneous ice nucleation activity of bacteria: new laboratory experiments at simulated cloud conditions  

NASA Astrophysics Data System (ADS)

The ice nucleation activities of five different Pseudomonas syringae, Pseudomonas viridiflava and Erwinia herbicola bacterial species and of SnomaxTM were investigated in the temperature range between -5 and -15°C. Water suspensions of these bacteria were directly spray into the cloud chamber of the AIDA facility of Forschungszentrum Karlsruhe at a temperature of -5.7°. At this temperature, about 1% of the SnomaxTM cells induced freezing of the spray droplets before they evaporated in the cloud chamber. The other suspensions of living cells didn't induce any measurable ice concentration during spray formation at -5.7°. The remaining aerosol was exposed to typical cloud activation conditions in subsequent experiments with expansion cooling to about -11°C. During these experiments, the bacterial cells first acted as cloud condensation nuclei to form cloud droplets and then eventually acted as ice nuclei to freeze the droplets. The results indicate that the bacteria investigated in the present study are mainly ice active in the temperature range between -7 and -11°C with an INA fraction of the order of 10-4. The ice nucleation efficiency of SnomaxTM cells was much larger with an INA fraction of 0.2 at temperatures around -8°C.

Möhler, O.; Georgakopoulos, D. G.; Morris, C. E.; Benz, S.; Ebert, V.; Hunsmann, S.; Saathoff, H.; Schnaiter, M.; Wagner, R.

2008-04-01

196

Heterogeneous ice nucleation activity of bacteria: new laboratory experiments at simulated cloud conditions  

NASA Astrophysics Data System (ADS)

The ice nucleation activities of five different Pseudomonas syringae, Pseudomonas viridiflava and Erwinia herbicola bacterial species and of Snomax™ were investigated in the temperature range between -5 and -15°C. Water suspensions of these bacteria were directly sprayed into the cloud chamber of the AIDA facility of Forschungszentrum Karlsruhe at a temperature of -5.7°C. At this temperature, about 1% of the Snomax™ cells induced immersion freezing of the spray droplets before the droplets evaporated in the cloud chamber. The living cells didn't induce any detectable immersion freezing in the spray droplets at -5.7°C. After evaporation of the spray droplets the bacterial cells remained as aerosol particles in the cloud chamber and were exposed to typical cloud formation conditions in experiments with expansion cooling to about -11°C. During these experiments, the bacterial cells first acted as cloud condensation nuclei to form cloud droplets. Then, only a minor fraction of the cells acted as heterogeneous ice nuclei either in the condensation or the immersion mode. The results indicate that the bacteria investigated in the present study are mainly ice active in the temperature range between -7 and -11°C with an ice nucleation (IN) active fraction of the order of 10-4. In agreement to previous literature results, the ice nucleation efficiency of Snomax™ cells was much larger with an IN active fraction of 0.2 at temperatures around -8°C.

Möhler, O.; Georgakopoulos, D. G.; Morris, C. E.; Benz, S.; Ebert, V.; Hunsmann, S.; Saathoff, H.; Schnaiter, M.; Wagner, R.

2008-10-01

197

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

PubMed

Oil-suspended particulate matter aggregation (OSA) has been recognized by the oil spill remediation community to effectively enhance the cleansing of spilled oil in the marine environment. While studies have investigated the application of mineral fines as an effective method to facilitate oil dispersion, decision-makers still lack information on the role of mixing energy in OSA formation and its significance to oil dispersion in real spills. This work studied the effect of level and duration of mixing energy on OSA formation using the standard reference material 1,941 b and Arabian light crude oil. The results showed that dispersed small oil droplets increased with an increase of both the level and duration of mixing energy to form multi-droplet OSAs. The sizes of the dispersed droplets varied between 5 and 10 ?m under different conditions studied. The maximum oil trapping efficiency increased from 23% to 33%, the oil to sediment ratio increased from 0.30 to 0.43 g oil/g sediment, and the required shaking time decreased from 2.3 to 1.1h as the shaking rate increased from 2.0 to 2.3 Hz. Based on the size measurement results, a breakage effect on the formed OSAs and sediment flocs was confirmed under high mixing energy level. PMID:24462999

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

2014-03-01

198

Soil mercury and CO2 emissions and their relationship under controlled laboratory conditions: Effects of oxygen depletion and soil sterilization  

NASA Astrophysics Data System (ADS)

Terrestrial carbon (C) pools play an important role in uptake, deposition, sequestration, and emission of atmospheric mercury (Hg). Thus, we investigated the fate of Hg during C mineralization processes using a laboratory flux set-up to evaluate to what degree decomposition of organic matter leads to emission and re- emission of Hg to the atmosphere, increased mobilization within terrestrial ecosystems, or long-term sequestration. Our laboratory system was supplied by air from pressurized tanks and allowed concurrent measurements of Hg and CO2 fluxes from 6 replicate soils chambers under controlled environmental conditions. Experimental treatments of flux samples included manipulations of C mineralization rates (by means of O2 depletion, sterilization, etc.). Results showed an excellent control on soil fluxes and highly accurate and replicable measurements of soil Hg and CO2 (i.e., mineralization) fluxes and little direct relationships between soil mineralization and Hg emission rates. Surprisingly though, soil Hg emissions increased in soils under anaerobic conditions (depletion of O2) indicating that low soil redox potential and/or anaerobic microbes might enhance Hg emission from terrestrial soils.

Berger, C.; Fain, X.; Obrist, D.

2008-12-01

199

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

PubMed Central

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

Harrison, F L; Lam, J R

1986-01-01

200

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

NASA Astrophysics Data System (ADS)

The major factor determining the rate of weathering of a given rock are the climatic conditions of the surrounding environment, most notably type and amount of precipitation and temperature. For the latter, average annual temperature and where applicable, the frequency of freezing and thawing are often considered to be relevant for weathering. The rate of temperature change is mostly ignored. However, a rapid change in temperature, referred to as thermal shock could have more severe consequences of rock deterioration then gradual heating and cooling of rocks is gradual. Thermal shock induces a stress of such a magnitude that the material is unable to adjust fast enough and so it breaks down. The aim of this study is to examine the importance of mechanical decomposition of rocks when treated with thermal shock by freezing. The rate of decomposition of rocks of various sizes was measured based on their weight loss. In addition, they were immersed in water after freezing and the electrical conductivity and pH of the water were measured as an index for thermal-shock induced micro-fracturing. Samples of three rock types were chosen for the experiment: limestone, tuffaceous rock and basalt. Samples were examined in two separate cycles: (i) 24h immersion in ultra-clean water followed by 24h drying at 30o and (ii) 24h immersion, 24h temperature shock by freezing at -20?C and 6h thawing. Each cycle was repeated approximately 20 times. In each cycle three different sizes of rock were examined: <16mm, 16-8mm and 8-5mm. Limestone mass decreased for both cycles, although more distinctly after repeated thermal shocks. Furthermore, the rate of decay decreased with increasing rock size. Tuffaceous rock exposed to cycle (i) also showed a significant weight loss. Somewhat surprisingly, the mass of the tuffaceous rock exposed to thermal shock increased by about 13% in all sample size groups. It is possible that pore volume increased during experiment and that the rocks became capable of absorbing more water, but the rock was elastic enough not to break under stress. On the basalt, as expected, the rate of weight loss was the smallest. Cylce (ii) samples also showed more intensive mass reduction. Electrical conductivity and pH of the immersion water were constant throughout the experiment and did not change with the number of cycles. This implies that no significant chemical disintegration occurred. The results show that thermal shock can have a rock type-specific effect on physical weathering. The lacking effect on chemical weathering is expected due to the design of the experiment. Under natural conditions, with non-pH neutral water, the declining rock stability, indicated by the loss of mass, especially of the limestone, will mostly likely also enhance leaching and thus chemical weathering.

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

2013-04-01

201

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

PubMed

Yellow Sea green tides have occurred in coastal China almost every year from 2007 to 2011. Ulva prolifera (Müller) J. Agardh has been identified as the causative macroalgal species. U. intestinalis, however, has been observed in the bloom areas, co-occurring with U. prolifera, but it has not been found to be causative. The Yellow Sea green tide has shown consistent phases of development that match corresponding environmental changes. U. prolifera, not U. intestinalis, is dominant. Our experimental design was based on these observed phenomena, and the results of our field investigation indicated a close relationship between changes in principal environmental factors (irradiance, temperature, and salinity) and the development of each phase of the bloom. These main environmental factors were simulated to allow estimation and comparison of the physiological responses of U. prolifera and U. intestinalis. Ecophysiological differences were found between these two species. (1) More photosynthetic activity and plasticity were detected in U. prolifera. (2) U. prolifera was found to be more sensitive to dynamic environments, especially harsh and changing environmental conditions. U. intestinalis was found to be more stable, probably due to the higher stress tolerance given by its antioxidant system. (3) Markedly higher nutrient absorption activity was observed in U. prolifera. Comparisons of the ecophysiological traits of these two species in this present study may foster understanding of their natural ecological processes. Specifically, U. prolifera seemed to be more engaged with the ephemeral blooms, while U. intestinalis seemed to be directed toward persistence. This also suggests that the ecological success of U. prolifera may be inextricably linked to its higher capacity for photosynthesis, nutrient absorption, and nutrient assimilation. PMID:22905087

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

2012-01-01

202

Comparative Studies on the Ecophysiological Differences of Two Green Tide Macroalgae under Controlled Laboratory Conditions  

PubMed Central

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

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

2012-01-01

203

The Biology and some Population Parameters of the Grasshopper, Ronderosia bergi, Under Laboratory Conditions  

PubMed Central

Some biological and population parameters of Ronderosia bergi (Stål) (Orthoptera: Acrididae: Melanoplinae) were estimated by monitoring five cohorts of the first generation (F1) of individuals born in captivity from grasshoppers collected in the South of Misiones province, northeastern Argentina, and held under controlled conditions (30° C, 14:10 L:D, 40% RH). The mean embryonic development time was 40.6 ± 1.7 days. Five nymphal instars were recorded. Total duration of nymphal development was 30.8 ± 0.54 days. The mean lifespan of cohorts was 22.6 ± 0.7 weeks. The number of egg-pods per female was 7.6 ± 1.44, and the amount of eggs per egg-pod was 16.45 ± 0.85. Mean fecundity was 125 ± 5.83 eggs per female with an oviposition rate of 1.55 ± 0.57 eggs/female/day. Survivorship curves showed that mortality was concentrated in the final weeks of adulthood, and the life expectancy curve decreased accordingly. The population parameters estimated gave the following values: the net rate of reproduction (R0) was 46.75 ± 11.2, generation time (T) was 18.87 ± 1.67 weeks, duplication time (D) was 3.31 ± 0.34, the intrinsic rate of population growth (rm) was 0.21 ± 0.021 and the finite rate of population increase (?) was 1.24 ± 0.026. The reproductive values (Vx) indicated that the largest contribution of females to the subsequent generation was between weeks 15 and 25.

Mariottini, Yanina; de Wysiecki, Maria Laura; Lange, Carlos

2010-01-01

204

Temporal variability in (13)C of respired CO(2) in a pine and a hardwood forest subject to similar climatic conditions.  

PubMed

Temporal variability in the (13)C of foliage (delta(13)C(F)), soil (delta(13)C(S)) and ecosystem (delta(13)C(R)) respired CO(2) was contrasted between a 17.2-m tall evenly aged loblolly pine forest and a 35-m tall unevenly aged mature second growth mixed broadleaf deciduous forest in North Carolina, USA, over a 2-year period. The two forests are located at the Duke Forest within a kilometer of each other and are subject to identical climate and have similar soil types. The delta(13)C(F), collected just prior to dawn, was primarily controlled by the time-lagged vapor pressure deficit (VPD) in both stands; it was used for calculating the ratio of intercellular to ambient CO(2) ( Ci/ Ca). A remarkable similarity was observed in the relationship between Ci/ Ca and time-lagged VPD in these two forests despite large differences in hydraulic characteristics. This similarity emerged as a result of physiological adjustments that compensated for differences in plant hydraulic characteristics, as predicted by a recently proposed equilibrium hypothesis, and has implications to ecophysiological models. We found that in the broadleaf forest, the delta(13)C of forest floor CO(2) efflux dominated the delta(13)C(R), while in the younger pine forest, the delta(13)C of foliage respired CO(2) dominated delta(13)C(R). This dependence resulted in a more variable delta(13)C(R) in the pine forest when compared to the broadleaf forest due to the larger photosynthetic contribution. Given the sensitivity of the atmospheric inversion models to delta(13)C(R), the results demonstrate that these models could be improved by accounting for stand characteristics, in addition to previously recognized effects of moisture availability, when estimating delta(13)C(R). PMID:15340829

Mortazavi, Behzad; Chanton, Jeffrey P; Prater, James L; Oishi, A Christopher; Oren, Ram; Katul, Gabriel

2005-01-01

205

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

Code of Federal Regulations, 2010 CFR

...other critical analytical and laboratory purposes. Pursuant to Decision...essential under the global laboratory exemption: a. Testing... b. Testing of tar in road-paving materials; and... Production for essential laboratory and analytical purposes...

2009-07-01

206

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

Code of Federal Regulations, 2010 CFR

...other critical analytical and laboratory purposes. Pursuant to Decision...essential under the global laboratory exemption: a. Testing... b. Testing of tar in road-paving materials; and... Production for essential laboratory and analytical purposes...

2010-07-01

207

Similar potential ATP-P production and enzymatic activities in the microplankton community off Concepción (Chile) under oxic and suboxic conditions  

NASA Astrophysics Data System (ADS)

The effects of the oxygen minimum zone on the metabolism of the heterotrophic microplankton community (0.22-100 ?m) in the Humboldt Current System, as well as the factors controlling its biomass production, remain unknown. Here we compare the effect of four sources of dissolved organic carbon (glucose, oxaloacetate, glycine, leucine) on microbial biomass production (such as ATP-P) and the potential enzymatic activities involved in catabolic pathways under oxic and suboxic conditions. Our results show significant differences ( p < 0.05) in the ATP-P production when induced by the different substrates that are used as dissolved organic carbon herein. The induction of ATP-P production is enhanced from glucose < oxaloacetate < glycine < leucine. Nevertheless, for individual substrates, no significant differences were found between incubation under oxic and suboxic conditions except in the case of leucine. For this amino acid, the induction of ATP-P synthesis was higher under suboxic than oxic conditions. The data sets of all the substrates used showed greater potential ATP-P production under suboxic than oxic conditions. The results of the potential enzymatic activities suggest that malate dehydrogenase has the highest signal of NADH oxidization activity in the microbial assemblage. Furthermore, for all experiments, the malate dehydrogenase activity data set had a significant relationship with ATP-P production. These findings suggest that the microbial community inhabiting the oxygen minimum zone has the same or greater potential growth than the community inhabiting more oxygenated strata of the water column and that malate dehydrogenase is the activity that best represents the metabolic potential of the community.

González, Rodrigo R.; Gutiérrez, Marcelo H.; Quiñones, Renato A.

2007-11-01

208

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

PubMed

Transgenic rice expressing Bacillus thuringiensis Berliner (Bt) protein can effectively control target insects including stem borers and leaf folders. However, the potential effects of Bt rice on nontarget organisms including nontarget herbivores have not been fully evaluated. In the current study, ecological fitness parameters of the nontarget herbivore, Nephotettix cincticeps (Uhler) (Hemiptera: Cicadellidae), fed on T1C-19 (Cry1C) or T2A-1 (Cry2A) rice were compared with non-Bt rice (MH63) under laboratory conditions. A 2-yr field trial was also conducted to monitor the population dynamics of N. cincticeps in the Bt and control rice plots using the vacuum-suction machine and yellow sticky card traps. Laboratory results showed that there were no significant differences in some of biological parameters including egg developmental duration, adult fresh weight, adult longevity, and oviposition period when N. cincticeps fed on Bt or non-Bt rice was compared. However, the survival rate of N. cincticeps nymphs fed on T2A-1 Bt rice plants was significantly higher than that on the control. When N. cincticeps fed on T1C-19 Bt rice plants, its nymphal duration was significantly longer and fecundity significantly lower compared with those fed on both T2A-1 Bt and non-Bt rice plants; the preoviposition period of N. cincticeps fed on T1C-19 and T2A-1 Bt rice was also significantly shorter than those on non-Bt rice. Nonetheless, both seasonal density and population dynamics of N. cincticeps adults and nymphs were similar between Bt (T1C-19 and T2A-1) and non-Bt rice plots under field conditions. In conclusion, our results indicate that our two tested Bt rice lines would not lead to higher population of N. cincticeps. Long-term experiments to monitor the population dynamics of N. cincticeps at large scale need to be carried out to confirm the current results. PMID:24472210

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

2014-02-01

209

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

SciTech Connect

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

Gomez Cendra, P.; Vilardi, J. [Depto. Ecologia, Genetica y Evolucion, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, (1428) Buenos Aires (Argentina); Segura, D.; Cladera, J. [Instituto de Genetica, INTA Castelar, CC25, (1712), Buenos Aires (Argentina); Allinghi, A. [Comision Nacional de Energia Atomica, CNEA, Buenos Aires (Argentina)

2007-03-15

210

Interaction between Paranosema locustae and Metarhizium anisopliae var. acridum, two pathogens of the desert locust, Schistocerca gregaria under laboratory conditions.  

PubMed

The interaction between two pathogens, the microsporidian Paranosema locustae Canning and the fungus Metarhizium anisopliae var. acridum Driver and Milner was studied under laboratory conditions in an attempt to develop an improved method of microbial control for the desert locust, Schistocerca gregaria Forskål. Fifth-instar locust nymphs, reared in the laboratory, were treated with various concentrations of one of the two pathogens or with both pathogens. The numbers of locusts killed were recorded each day and the production of pathogen spores within the dead locusts was assessed at the end (day 21) of each experiment. Locust nymphs treated with both P. locustae and M. anisopliae died sooner than nymphs infected with only one of the pathogens. At the lower concentrations of pathogen tested, the effects of the two pathogens were additive. At the higher concentrations the combined effects were synergistic. In terms of locust mortality, there was no evidence of any antagonistic effects between the two pathogens. However, the production of spores by P. locustae was reduced considerably when the host insects were infected also with M. anisopliae. For example, nymphs treated initially with P. locustae and then treated 3 and 10 days later with M. anisopliae produced 3-20 times and 2.5-8 times fewer spores, respectively, than nymphs treated only with P. locustae. Hence, in areas where M. anisopliae is applied, the natural persistence of P. locustae in the local grasshopper and locust populations may be diminished. PMID:18005982

Tounou, A-K; Kooyman, C; Douro-Kpindou, O-K; Poehling, H-M

2008-03-01

211

Two initial vaccinations with the Bm86-based Gavacplus vaccine against Rhipicephalus (Boophilus) microplus induce similar reproductive suppression to three initial vaccinations under production conditions  

PubMed Central

Background The cattle tick, Rhipicephalus (Boophilus) microplus, affects livestock production in many regions of the world. Up to now, the widespread use of chemical acaricides has led to the selection of acaricide-resistant ticks and to environmental contamination. Gavacplus is a subunit vaccine based on the recombinant Bm86 tick antigen expressed in yeast, capable to control infestations of R. microplus under controlled and production conditions. The vaccine constitutes the core element of broad control programs against this ectoparasite, in which acquired immunity in cattle to Bm86 is combined with a rational use of acaricides. At present, the conventional vaccine scheme consists of three doses that should be administered at weeks 0, 4 and 7, followed by a booster every six months. Results In this study we assayed a reduction in the number of the initial doses of Gavacplus, evaluated the time course and the level of bovine anti-Bm86 antibodies elicited, and analyzed the vaccine effect on ticks engorging on immunized cattle under production conditions. Following three different immunization schemes, the bovines developed a strong and specific immune response characterized by elevated anti-Bm86 IgG titers. A reduction in the weight of engorging female ticks, in the weight of the eggs laid and also in R. microplus viable eggs percentage was obtained by using only two doses of Gavacplus administered at weeks 0 and 4, followed by a booster six months later. This reduction did not differ from the results obtained on ticks engorging on cattle immunized at weeks 0, 4 and 7. It was also demonstrated that anti-Bm86 antibody titers over 1:640, measured in bovines immunized at weeks 0 and 4, were sufficient to affect weight and reproductive potential of female ticks as compared with ticks engorging on unvaccinated animals. In addition, no statistically significant differences were detected in the average weight of eggs laid by ticks engorged on immunized cattle that showed anti-Bm86 specific titers in the range of 1:640 to 1:81920. Conclusion The administration of two initial doses of Gavacplus containing 100 ?g of Bm86 antigen to non-immunized cattle under production conditions is sufficient to affect the weight and the reproductive capacity of R. microplus engorging females. According to these results, cattle herds' manipulation and vaccine costs could be potentially reduced with a positive impact on the implementation of integrated control programs against R. microplus.

2010-01-01

212

Mice with a Conditional Deletion of the Neurotrophin Receptor TrkB Are Dwarfed, and Are Similar to Mice with a MAPK14 Deletion  

PubMed Central

Long bone growth results from ordered chondrocyte development within the cartilagenous growth plate. Chondrocytes are recruited from a resting pool to proliferate along the long axis of the bone, until various signals trigger differentiation and hypertrophy. We have shown previously that the neurotrophin receptor TrkB is expressed in growth plate chondrocytes, where the tyrosine kinase receptor regulates the pace of hypertrophic differentiation by modulating the activities of ERK and p38 MAP kinases. To investigate the physiological relevance of TrkB to bone growth in vivo, we generated mice with a targeted disruption of the receptor, and compared them to mice targeted for MAPK14, the gene for p38?. The TrkB mutant and p38? mutant mice showed a similar degree of dwarfism and delayed hypertrophic differentiation. To extend these findings, we showed that both the TrkB and p38? mutant mice have altered expression of Runx2 and Sox9, two key transcription factors required for skeletogenesis. The data provides in vivo evidence for the role of TrkB in bone growth, supports the role of p38 downstream of TrkB, and suggests that Runx2 and Sox9 expression is regulated by this pathway at the growth plate.

Hutchison, Michele R.

2013-01-01

213

Wave operators, similarity and dynamics for a class of Schrödinger operators with generic non-mixed interface conditions in 1D  

SciTech Connect

We consider a simple modification of the 1D-Laplacian where non-mixed interface conditions occur at the boundaries of a finite interval. It has recently been shown that Schrödinger operators having this form allow a new approach to the transverse quantum transport through resonant heterostructures. In this perspective, it is important to control the deformations effects introduced on the spectrum and on the time propagator by this class of non-selfadjoint perturbations. In order to obtain uniform-in-time estimates of the perturbed semigroup, our strategy consists in constructing stationary wave operators allowing to intertwine the modified non-selfadjoint Schrödinger operator with a “physical” Hamiltonian. For small values of a deformation parameter “?,” this yields a dynamical comparison between the two models showing that the distance between the corresponding semigroups is dominated by ??? uniformly in time in the L{sup 2}-operator norm.

Mantile, Andrea [Laboratoire de Mathématiques, Université de Reims - FR3399 CNRS, Moulin de la Housse BP 1039, 51687 Reims (France)] [Laboratoire de Mathématiques, Université de Reims - FR3399 CNRS, Moulin de la Housse BP 1039, 51687 Reims (France)

2013-08-15

214

Modeling of salt-water migration through spod-podzolic soils under the field and laboratory conditions  

NASA Astrophysics Data System (ADS)

The assessment of highly mineralized water influence on soils is an important issue in the contemporary world. Various regions with different conditions are exposed to salt-affected soils forming. Salinization of soils is a complex process of the chemical and physical properties changes. Therefore the chain of the laboratory and field experiments should be done in order to assess the main factors promoting highly mineralized water migration. In addition to it modelling is a good way to understand and evaluate main chemical and physical transformations in soils. The chain of experiments was done to assess salt water movement in spod-podzolic soils under field and laboratory conditions. The main goals were to evaluate the rate of salt water movement through soils and to estimate velocity of the desalinization process. Field experiment was conducted on spod-podzolic soils of Kaliningrad region. There were 4 sites measuring 20*25 cm watering with salt water in amount of 5 liters per each area. The mineralization of the solution was 100 g/l. In addition to the salt affected sites, 2 non polluted grounds were assessed too. Soils samples were collected in the period of 1 week, 1 month, 3 month and 1 year after the spill had been done. The samples were taken each 10 cm 110 cm deep and in double repeatability. Main chemical and physical parameters, such as volume water content, pH, conductivity, amount of calcium ion, magnesium, sodium, and chlorite in soils etc. were measured in each sample. The second experiment was conducted to evaluate the rate of soils solutions transformation under the laboratory conditions. Organic horizon was taken from the field and was stuffed in columns with 1.0 g/cm3 density. There were 16 columns with 4 cm diameter. 14 columns were showered with salt water with the same mineralization as in the field experiment. The amount of salt water injected in columns was 104 mm per one sample which is equal to the salt water volume spilled per one area in the previous experiment. Also there were 2 columns as a verification variant contained pure soil. Each column was washed off with different amount of distilled water. The total volume of the pure solution was equal to the mean amount of the annual precipitation in the region of the field experiment. The main physical and chemical properties were measured in soils samples as well in the first experiment. In addition to it the complex assessment of soil's water were made. The experiments revealed the fast rate of salinization-desalinization processes in spod-podzolic soils of the coniferous areas in Kaliningrad region. The maximum values of conductivity were observed at the end of 1 week period and made up more than 2000 mSm/cm in top soils horizons. Furthermore the desalinization of the soils took place in both field and laboratory experiments a year after the spill. The reported study was partially supported by RFBR, research project No 12-05-31088 mol_a.

Ronzhina, Tatiana

2013-04-01

215

Similar overall survival using sibling, unrelated donor, and cord blood grafts after reduced-intensity conditioning for older patients with acute myelogenous leukemia.  

PubMed

For older patients with acute myeloid leukemia (AML), allogeneic hematopoietic cell transplantation (HCT) provides the best chance of long-term survival. A formal comparison between matched sibling (SIB), unrelated donor (URD), or umbilical cord blood (UCB) transplantation has not yet been reported in this setting. We compared reduced-intensity conditioning HCT in 197 consecutive patients 50 years and older with AML in complete remission from SIB (n = 82), URD (n = 35), or UCB (n = 80) transplantation. The 3-year cumulative incidences of transplantation-related mortality were 18%, 14%, and 24% with SIB, URD, and UCB transplantation, respectively (P = .22). The 3-year leukemia-free survival rates were 48%, 57%, and 33% with SIB, URD, and UCB transplantation, respectively (P = .009). In multivariate analysis, poor-risk cytogenetics was associated with relapse (hazard ratio, 1.7 [95% confidence interval, 1.0 to 3.0]; P = .04) and worse leukemia-free survival (hazard ratio, 1.6 [95% confidence interval, 1.0 to 2.5]; P = .03), whereas donor choice had no significant impact on overall survival (P = .73). Adjusted 3-year overall survival rates were 55% with SIB, 45% with URD, and 43% with UCB transplantation (P = .26). Until prospective studies are completed, this study supports the recommendation to consider SIB donor, URD, or UCB for HCT for older patients with AML in complete remission. PMID:23791622

Peffault de Latour, Régis; Brunstein, Claudio G; Porcher, Raphael; Chevallier, Patrice; Robin, Marie; Warlick, Erica; Xhaard, Alienor; Ustun, Celalettin; Larghero, Jérôme; Dhedin, Nathalie; Mohty, Mohamad; Socié, Gerard; Weisdorf, Daniel

2013-09-01

216

Alternative donor hematopoietic stem cell transplantation for mature lymphoid malignancies after reduced-intensity conditioning regimen: similar outcomes with umbilical cord blood and unrelated donor peripheral blood.  

PubMed

We have reported encouraging results of unrelated cord blood transplantation for patients with lymphoid malignancies. Whether those outcomes are comparable to matched unrelated donor transplants remains to be defined. We studied 645 adult patients with mature lymphoid malignancies who received an allogeneic unrelated donor transplant using umbilical cord blood (n=104) or mobilized peripheral blood stem cells (n=541) after a reduced-intensity conditioning regimen. Unrelated cord blood recipients had more refractory disease. Median follow-up time was 30 months. Neutrophil engraftment (81% vs. 97%, respectively; P<0.0001) and chronic graft-versus-host disease (26% vs. 52%; P=0.0005) were less frequent after unrelated cord blood than after matched unrelated donor, whereas no differences were observed in grade II-IV acute graft-versus-host disease (29% vs. 32%), non-relapse mortality (29% vs. 28%), and relapse or progression (28% vs. 35%) at 36 months. There were also no significant differences in 2-year progression-free survival (43% vs. 58%, respectively) and overall survival (36% vs. 51%) at 36 months. In a multivariate analysis, no differences were observed in the outcomes between the two stem cell sources except for a higher risk of neutrophil engraftment (hazard ratio=2.12; P<0.0001) and chronic graft-versus-host disease (hazard ratio 2.10; P=0.0002) after matched unrelated donor transplant. In conclusion, there was no difference in final outcomes after transplantation between umbilical cord blood and matched unrelated donor transplant. Umbilical cord blood is a valuable alternative for patients with lymphoid malignancies lacking an HLA-matched donor, being associated with lower risk of chronic graft-versus-host disease. PMID:23935024

Rodrigues, Celso Arrais; Rocha, Vanderson; Dreger, Peter; Brunstein, Claudio; Sengeloev, Henrik; Finke, Jürgen; Mohty, Mohamad; Rio, Bernard; Petersen, Eefke; Guilhot, François; Niederwieser, Dietger; Cornelissen, Jan J; Jindra, Pavel; Nagler, Arnon; Fegueux, Nathalie; Schoemans, Hélène; Robinson, Stephen; Ruggeri, Annalisa; Gluckman, Eliane; Canals, Carmen; Sureda, Anna

2014-02-01

217

Effects of greenhouse pesticides on the soil-dwelling predatory mite Stratiolaelaps scimitus (Acari: Mesostigmata: Laelapidae) under laboratory conditions.  

PubMed

Knowledge of the effects of pesticides on biological control agents is required for the successful implementation of integrated pest management (IPM) programs in greenhouse production systems. Laboratory assays were conducted to assess the effects of an acaricide (dicofol), two insecticides (chlorpyrifos and pyriproxyfen), and two fungicides (fosetyl-Al and mefenoxam) on Stratiolaelaps scimitus (Womersley), a soil-dwelling predatory mite widely marketed in North America under the name Hypoaspis miles (Berlese) as a biological control agent of dark-winged fungus gnats (Bradysia spp.). Eggs, larvae, protonymphs, deutonymphs, and adult male and female mites were first assayed using dicofol, an acaricide used in the experiments as a positive control, applied to filter paper in an enclosed arena. Protonymphs were assayed for lethal and sublethal effects against the remaining pesticides at maximum label-recommended rates applied to filter paper, by using dicofol as a positive control and water as a negative control. The larva and protonymph were the life stages most susceptible to dicofol, with estimated 24-h LC50 values of 9 and 26 mg m(-2), respectively. Chlorpyrifos was highly toxic to the protonymphs of S. scimitus, causing >95% mortality after 24-h exposure and 100% mortality after 48 h. In contrast, the insect growth regulator (IGR) pyriproxyfen was much less toxic to protonymphs of S. scimitus; pyriproxyfen caused no significant mortality, compared with <5% mortality in the water control. Mortality caused by the fungicides was also relatively low; 72-h exposure to fosetyl-Al and mefenoxam resulted in 17.4 and 27.5% mortality, respectively. The IGR and fungicides increased the duration of the protonymphal stage by 1.2-1.8-fold, but they had no effect on the duration of subsequent life stages, nor on the duration of preoviposition, oviposition, and postoviposition periods of adult females. Total numbers and viability of eggs laid by mites exposed to the IGR and fungicides did not differ from the negative control, although the average rate of egg production during the oviposition of mites exposed to fosetyl-Al was increased. Pyriproxyfen, fosetyl-Al, and mefenoxam are likely to be compatible with S. scimitus under field conditions, because these pesticides caused little mortality of protonymphs, and they did not negatively affect the development and reproduction of S. scimitus under extreme laboratory conditions. In contrast, the use of chlorpyrifos in conjunction with S. scimitus is not recommended unless more comprehensive testing under semifield or field conditions demonstrates compatibility. PMID:15279255

Cabrera, Ana R; Cloyd, Raymond A; Zaborski, Edmond R

2004-06-01

218

Gamma butyrolactone (GBL) and gamma valerolactone (GVL): similarities and differences in their effects on the acoustic startle reflex and the conditioned enhancement of startle in the rat.  

PubMed

Gamma butyrolactone (GBL) is metabolized to gamma hydroxybutyrate (GHB) in the body. GHB is a DEA Schedule 1 compound; GBL is a DEA List 1 chemical. Gamma valerolactone (GVL) is the 4-methyl analog of GBL; GVL is metabolized to 4-methyl-GHB; GVL is NOT metabolized to GBL or GHB. The effects of GBL (18.75-150 mg/kg), GVL (200-1600 mg/kg) or vehicle on the acoustic startle reflex (ASR), and the classically-conditioned enhancement of startle, the Startle Anticipated Potentiation of Startle (SAPS) response were studied in male rats. Both compounds produced a dose-dependent reduction of ASR, with GBL 5-7 times more potent than GVL. In contrast, GBL treatment significantly reduced SAPS at doses that exerted only moderate effects on ASR, whereas GVL exerted little or no effect on the SAPS, except at doses that produced pronounced reductions in Noise Alone ASR. In a second experiment, rats were tested for Noise Alone ASR behavior following treatment with a single mid-range dose of GBL (75 mg/kg), GVL (400mg/kg) or vehicle; immediately following startle testing the animals were sacrificed and their brains and blood were collected for determination of GHB, 4-methyl-GHB, GBL and GVL. GHB was found in measurable concentrations in all of the blood specimens and 6 (of 8) of the brain specimens from the GBL-treated subjects. 4-Methyl-GHB was found in measurable concentrations in all of the blood and brain specimens of the GVL-treated subjects; the change in startle amplitude was inversely correlated to the brain concentrations of these compounds. These findings confirm the differences in the metabolic fate of GBL and GVL as pro-drugs for the formation of GHB and 4-methyl-GHB, respectively. Moreover, the dissimilarity in effect profile for GBL and GVL on ASR versus SAPS behaviors suggests that different receptor(s) may be involved in mediating these behavioral effects. PMID:22349589

Marinetti, Laureen J; Leavell, Bonita J; Jones, Calleen M; Hepler, Bradford R; Isenschmid, Daniel S; Commissaris, Randall L

2012-06-01

219

Pathogenicity of the Entomopathogenic Fungus, Lecanicillium muscarium , against the Sweetpotato Whitefly Bemisia tabaci under Laboratory and Glasshouse Conditions  

Microsoft Academic Search

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

Andrew G. S. Cuthbertson; Keith F. A. Walters

2005-01-01

220

In search of water vapor on Jupiter: Laboratory measurements of the microwave properties of water vapor under simulated jovian conditions  

NASA Astrophysics Data System (ADS)

Detection and measurement of atmospheric water vapor in the deep jovian atmosphere using microwave radiometry has been discussed extensively by Janssen et al. (Janssen, M.A., Hofstadter, M.D., Gulkis, S., Ingersoll, A.P., Allison, M., Bolton, S.J., Levin, S.M., Kamp, L.W. [2005]. Icarus 173 (2), 447-453.) and de Pater et al. (de Pater, I., Deboer, D., Marley, M., Freedman, R., Young, R. [2005]. Icarus 173 (2), 425-447). The NASA Juno mission will include a six-channel microwave radiometer system (MWR) operating in the 1.3-50 cm wavelength range in order to retrieve water vapor abundances from the microwave signature of Jupiter (see, e.g., Matousek, S. [2005]. The Juno new frontiers mission. Tech. Rep. IAC-05-A3.2.A.04, California Institute of Technology). In order to accurately interpret data from such observations, nearly 2000 laboratory measurements of the microwave opacity of H 2O vapor in a H 2/He atmosphere have been conducted in the 5-21 cm wavelength range (1.4-6 GHz) at pressures from 30 mbars to 101 bars and at temperatures from 330 to 525 K. The mole fraction of H 2O (at maximum pressure) ranged from 0.19% to 3.6% with some additional measurements of pure H 2O. These results have enabled development of the first model for the opacity of gaseous H 2O in a H 2/He atmosphere under jovian conditions developed from actual laboratory data. The new model is based on a terrestrial model of Rosenkranz et al. (Rosenkranz, P.W. [1998]. Radio Science 33, 919-928), with substantial modifications to reflect the effects of jovian conditions. The new model for water vapor opacity dramatically outperforms previous models and will provide reliable results for temperatures from 300 to 525 K, at pressures up to 100 bars and at frequencies up to 6 GHz. These results will significantly reduce the uncertainties in the retrieval of jovian atmospheric water vapor abundances from the microwave radiometric measurements from the upcoming NASA Juno mission, as well as provide a clearer understanding of the role deep atmospheric water vapor may play in the decimeter-wavelength spectrum of Saturn.

Karpowicz, Bryan M.; Steffes, Paul G.

2011-03-01

221

Larval and juvenile Pacific herring Clupea pallasii are not susceptible to infectious hematopoietic necrosis under laboratory conditions  

USGS Publications Warehouse

Infectious hematopoietic necrosis (IHN) leads to periodic epidemics among certain wild and farmed fish species of the Northeast (NE) Pacific. The source of the IHN virus (IHNV) that initiates these outbreaks remains unknown; however, a leading hypothesis involves viral persistence in marine host species such as Pacific herring Clupea pallasii. Under laboratory conditions we exposed specific pathogen-free (SPF) larval and juvenile Pacific herring to 103 to 104 plaque-forming units (pfu) of IHNV ml–1 by waterborne immersion. Cumulative mortalities among exposed groups were not significantly different from those of negative control groups. After waterborne exposure, IHNV was transiently recovered from the tissues of larvae but absent in tissues of juveniles. Additionally, no evidence of viral shedding was detected in the tank water containing exposed juveniles. After intraperitoneal (IP) injection of IHNV in juvenile herring with 103 pfu, IHNV was recovered from the tissues of sub-sampled individuals for only the first 5 d post-exposure. The lack of susceptibility to overt disease and transient levels of IHNV in the tissues of exposed fish indicate that Pacific herring do not likely serve a major epizootiological role in perpetuation of IHNV among free-ranging sockeye salmon Oncorhynchus nerka and farmed Atlantic salmon Salmo salar in the NE Pacific.

Hart, L. M.; Traxler, G. S.; Garver, K. A.; Richard, J.; Gregg, J. L.; Grady, C. A.; Kurath, G.; Hershberger, P. K.

2011-01-01

222

Larval and juvenile Pacific herring Clupea pallasii are not susceptible to infectious hematopoietic necrosis under laboratory conditions.  

PubMed

Infectious hematopoietic necrosis (IHN) leads to periodic epidemics among certain wild and farmed fish species of the Northeast (NE) Pacific. The source of the IHN virus (IHNV) that initiates these outbreaks remains unknown; however, a leading hypothesis involves viral persistence in marine host species such as Pacific herring Clupea pallasii. Under laboratory conditions we exposed specific pathogen-free (SPF) larval and juvenile Pacific herring to 10(3) to 10(4) plaque-forming units (pfu) of IHNV ml(-1) by waterborne immersion. Cumulative mortalities among exposed groups were not significantly different from those of negative control groups. After waterborne exposure, IHNV was transiently recovered from the tissues of larvae but absent in tissues of juveniles. Additionally, no evidence of viral shedding was detected in the tank water containing exposed juveniles. After intraperitoneal (IP) injection of IHNV in juvenile herring with 10(3) pfu, IHNV was recovered from the tissues of sub-sampled individuals for only the first 5 d post-exposure. The lack of susceptibility to overt disease and transient levels of IHNV in the tissues of exposed fish indicate that Pacific herring do not likely serve a major epizootiological role in perpetuation of IHNV among free-ranging sockeye salmon Oncorhynchus nerka and farmed Atlantic salmon Salmo salar in the NE Pacific. PMID:21381516

Hart, Lucas M; Traxler, Garth S; Garver, Kyle A; Richard, Jon; Gregg, Jacob L; Grady, Courtney A; Kurath, Gael; Hershberger, Paul K

2011-01-21

223

Triboelectric Charging of Fine Particles: Understanding Sample Transport Under Simulated Martian Conditions for the Mars Science Laboratory  

NASA Astrophysics Data System (ADS)

We report on the nature of fine particle (lees than 150 micron) transport under simulated Martian conditions, in order to better understand the Mars Science Laboratory's sample acquisition, processing and handling subsystem (SA/SPaH). We find that triboelectric charging due to particle movement may have to be controlled in order for successful transport of fines that are created within the drill, processed through the sample handing system (CHIMERA), and delivered to the SAM and CheMin instruments. These fines will be transferred to the portioner, a 3 mm diameter, 8 mm deep distribution center where they will drop ~ 2 cm to the instrument inlet funnels. In our experiments, charging of the simulant (Mars Mojave Simulant - MMS) resulted in 1.5 to 3 nanocoulombs of charge for a 3g aliquot. Due to electrostatics, this process may result in clumping or charge repulsion of fines, which can result in particle sorting. Both of these results can potentially result in an inaccurate sample analysis for the onboard instruments.

Anderson, R. C.; Peters, G. H.; Beegle, L. W.; Manatt, K. S.; Fleming, G.; Sollitt, L.

2008-12-01

224

The residual life of bendiocarb on different substrates under laboratory and field conditions in Benin, Western Africa  

PubMed Central

Background The efficacy of bendiocarb against pyrethroid resistant An. gambiae and the residual life of this insecticide on different substrates were evaluated under laboratory and field conditions. Methods Bioassays according to the WHO (World Health Organization) standard protocol were carried out on different substrates impregnated with bendiocarb. Data were analyzed using a binomial regression model with R software. Results A good efficacy of the bendiocarb against pyrethroid resistant An. gambiae and a high variation of its residual life according to the surfaces treated was observed. The probability that a female mosquito died after exposure to a treated substrate was below 80% after 13 weeks for the teak wood; 7 weeks for the wall made with a mixture of sand and cement and 6 weeks for walls made with red clay and those made with a mixture of the red clay and cement. Conclusions Considering the residual life of bendiocarb on walls made with red clay, the main substrates treated during IRS campaigns in rural areas in Benin, more than 2 treatments rounds per year would be necessary to achieve a long term efficacy of IRS using bendiocarb in these areas. Financial and logistical resources required to achieve such levels of coverage need more political will from leaders of African endemic countries. While waiting for innovative malaria control tool, alternative insecticides or combinations of insecticides have to be used for insecticide resistance management in Benin.

2013-01-01

225

LABORATORY STUDY FOR THE REDUCTION OF CHROME (VI) TO CHROME (III) USING SODIUM METABISULFITE UNDER ACIDIC CONDITIONS  

SciTech Connect

This report describes the results from RPP-PLAN-32738, 'Test Plan for the Effluent Treatment Facility to Reduce Chrome(VI) to Chrome(I1I) in the Secondary Waste Stream', using sodium metabisulfite. Appendix A presents the report as submitted by the Center for Laboratory Sciences (CLS) to CH2M HILL Hanford Group, Inc. The CLS carried out the laboratory effort under Contract Number 21065, release Number 30. This report extracts the more pertinent aspects of the laboratory effort.

DUNCAM JB; GUTHRIE MD; LUECK KJ; AVILA M

2007-07-18

226

Testing Insecticidal Activity of Novel Chemically Synthesized siRNA against Plutella xylostella under Laboratory and Field Conditions  

PubMed Central

Background Over the last 60 years, synthetic chemical pesticides have served as a main tactic in the field of crop protection, but their availability is now declining as a result of the development of insect resistance. Therefore, alternative pest management agents are needed. However, the demonstration of RNAi gene silencing in insects and its successful usage in disrupting the expression of vital genes opened a door to the development of a variety of novel, environmentally sound approaches for insect pest management. Methodology/Principal Findings Six small interfering RNAs (siRNAs) were chemically synthesized and modified according to the cDNA sequence of P. xylostella acetylcholine esterase genes AChE1 and AChE2. All of them were formulated and used in insecticide activity screening against P. xylostella. Bioassay data suggested that Si-ace1_003 and Si-ace2_001 at a concentration of 3 µg cm?2 displayed the best insecticidal activity with 73.7% and 89.0%, mortality, respectively. Additional bioassays were used to obtain the acute lethal concentrations of LC50 and LC90 for Si-ace2_001, which were 53.66 µg/ml and 759.71 µg/ml, respectively. Quantitative Real-time PCR was used to confirm silencing and detected that the transcript levels of P. xylostella AChE2 (PxAChE2) were reduced by 5.7-fold compared to the control group. Consequently, AChE activity was also reduced by 1.7-fold. Finally, effects of the siRNAs on treated plants of Brassica oleracea and Brassica alboglabra were investigated with different siRNA doses. Our results showed that Si-ace2_001 had no negative effects on plant morphology, color and growth of vein under our experimental conditions. Conclusions The most important finding of this study is the discovery that chemically synthesized and modified siRNA corresponding to P. xylostella AChE genes cause significant mortality of the insect both under laboratory and field conditions, which provides a novel strategy to control P. xylostella and to develop bio-pesticides based on the RNA interference technology.

Gong, Liang; Chen, Yong; Hu, Zhen; Hu, Meiying

2013-01-01

227

Good Practice Recommendations in the Field of Heating, Ventilation, and Air Conditioning for Health Related Research Laboratories.  

ERIC Educational Resources Information Center

A collection of laboratory design notes to set forth minimum criteria required in the design of basic medical research laboratory buildings. Recommendations contained are primarily concerned with features of design which affect quality of performance and future flexibility of facility systems. Subjects of economy and safety are discussed where…

Laboratory Design Notes, 1966

1966-01-01

228

YUCCA Mountain Project - Argonne National Laboratory, Annual Progress Report, FY 1997 for activity WP 1221 unsaturated drip condition testing of spent fuel and unsaturated dissolution tests of glass.  

SciTech Connect

This document reports on the work done by the Nuclear Waste Management Section of the Chemical Technology Division of Argonne National Laboratory in the period of October 1996 through September 1997. Studies have been performed to evaluate the behavior of nuclear waste glass and spent fuel samples under the unsaturated conditions (low-volume water contact) that are likely to exist in the Yucca Mountain environment being considered as a potential site for a high-level waste repository. Tests with actinide-doped waste glasses, in progress for over 11 years, indicate that the transuranic element release is dominated by colloids that continuously form and span from the glass surface. The nature of the colloids that form in the glass and spent fuel testing programs is being investigated by dynamic light scattering to determine the size distribution, by autoradiography to determine the chemistry, and by zeta potential to measure the electrical properties of the colloids. Tests with UO{sub 2} have been ongoing for 12 years. They show that the oxidation of UO{sub 2} occurs rapidly, and the resulting paragenetic sequence of secondary phases forming on the sample surface is similar to that observed for uranium found in natural oxidizing environments. The reaction of spent fuel samples in conditions similar to those used with UO{sub 2} have been in progress for over six years, and the results suggest that spent fuel forms many of the same alteration products as UO{sub 2}. With spent fuel, the bulk of the reaction occurs via a through-grain reaction process, although grain boundary attack is sufficient to have reacted all of the grain boundary regions in the samples. New test methods are under development to evaluate the behavior of spent fuel samples with intact cladding: the rate at which alteration and radionuclide release occurs when water penetrates fuel sections and whether the reaction causes the cladding to split. Alteration phases have been formed on fine grains of UO{sub 2} in contact with small volumes of water within a several month period when the radiolysis product H{sub 2}O{sub 2} is added to the groundwater solution. The test setup has been mocked up for operation with spent fuel in the hot-cell.

Bates, J. K.; Buck, E. C.; Emery, J. W.; Finch, R. J.; Finn, P. A.; Fortner, J.; Hoh, J. C.; Mertz, C.; Neimark, L. A.; Wolf, S. F.; Wronkiewicz, D. J.

1998-09-18

229

Effects of Beauveria bassiana on Survival, Blood-Feeding Success, and Fecundity of Aedes aegypti in Laboratory and Semi-Field Conditions  

PubMed Central

The fungus Beauveria bassiana reduces Aedes aegypti longevity in laboratory conditions, but effects on survival, blood-feeding behavior, and fecundity in realistic environmental conditions have not been tested. Adult, female Ae. aegypti infected with B. bassiana (FI-277) were monitored for blood-feeding success and fecundity in the laboratory. Fungal infection reduced mosquito-human contact by 30%. Fecundity was reduced by (mean ± SD) 29.3 ± 8.6 eggs per female per lifetime in the laboratory; egg batch size and viability were unaffected. Mosquito survival, blood-feeding behavior, and fecundity were also tested in 5 meter×7 meter×4 meter semi-field cages in northern Queensland, Australia. Fungal infection reduced mosquito survival in semi-field conditions by 59–95% in large cages compared with 61–69% in small cages. One semi-field cage trial demonstrated 80% reduction in blood-feeding; a second trial showed no significant effect. Infection did not affect fecundity in large cages. Beauveria bassiana can kill and may reduce biting of Ae. aegypti in semi-field conditions and in the laboratory. These results further support the use of B. bassiana as a potential biocontrol agent against Ae. aegypti.

Darbro, Jonathan M.; Johnson, Petrina H.; Thomas, Matthew B.; Ritchie, Scott A.; Kay, Brian H.; Ryan, Peter A.

2012-01-01

230

YUCCA Mountain Project - Argonne National Laboratory, Annual Progress Report, FY 1997 for activity WP 1221 unsaturated drip condition testing of spent fuel and unsaturated dissolution tests of glass  

Microsoft Academic Search

This document reports on the work done by the Nuclear Waste Management Section of the Chemical Technology Division of Argonne National Laboratory in the period of October 1996 through September 1997. Studies have been performed to evaluate the behavior of nuclear waste glass and spent fuel samples under the unsaturated conditions (low-volume water contact) that are likely to exist in

J. K. Bates; E. C. Buck; J. W. Emery; R. J. Finch; P. A. Finn; J. Fortner; J. C. Hoh; C. Mertz; L. A. Neimark; S. F. Wolf; D. J. Wronkiewicz

1998-01-01

231

A review of hydrologic and geologic conditions related to the radioactive solid-waste burial grounds at Oak Ridge National Laboratory, Tennessee  

USGS Publications Warehouse

Solid waste contaminated by radioactive matter has been buried in the vicinity of Oak Ridge National Laboratory since 1944. By 1973, an estimated six million cubic feet of such material had been placed in six burial grounds in two valleys. The practice initially was thought of as a safe method for permanently removing these potentially hazardous substances from man's surroundings, but is now que.3tionable at this site because of known leaching of contaminants from the waste, transport in ground water, and release to the terrestrial and fluvial environments. This review attempts to bring together in a single document information from numerous published and unpublished sources regarding the past criteria used for selecting the Oak Ridge burial-ground sites, the historical development and conditions of these facilities as of 1974, the geologic framework of the Laboratory area and the movement of water and water-borne contaminants in that area, the effects of sorption and ion exchange upon radionuclide transport, and a description and evaluation of the existing monitoring system. It is intended to assist Atomic Energy Commission (now Energy Research and Development Administration) officials in the formulation of managerial decisions concerning the burial grounds and present monitoring methods. Sites for the first three burial grounds appear to have been chosen during and shortly after World War II on the basis of such factors as safety, security, and distance from sources of waste origin. By 1950, geologic criteria had been introduced, and in the latter part of that decade, geohydrologic criteria were considered. While no current criteria have been defined, it becomes evident from the historical record that the successful containment of radionuclides below land surface for long periods of time is dependent upon a complex interrelationship between many geologic, hydrologic, and geochemical controls, and any definition of criteria must include consideration of these factors. For the most part, the burial grounds have been developed by a simple cut and fill procedure similar to the operation of a municipal landfill. Low permeability of the residuum, high rainfall, shallow depth to ground water, the excavation of trenches below the water table, and other practices, have contributed to a condition of waste leaching in probably all of the burial grounds. Despite these conditions, only very small concentrations of radionuclides have been found in wells or otherwise attributed to the initial three, small sites in Bethel Valley. This fact, however, may be due in part to the scant extent of site monitoring of those burial grounds for transport of radionuclides in ground water, and to the discharge of liquid radioactive waste to the drainage in concentrations that probably would have masked the presence of contaminants derived from these burial grounds. In comparison to the Bethel Valley sites, larger amounts of radioactive contaminants have been found in wells, seeps, trench overflow, and the drainages that drain Burial Grounds 4 and 5 in Melton Valley. The movement of radionuclides from the trenches to the drainages show that the latter sites are not suitable for the retention of all contaminants under existing conditions, and invalidates the operational concept of long-term or permanent retention of all radionuclides in the geologic environment. The transport of many radioactive ions leached from the waste has been retarded by the very high sorptive and ion exchange capacity of the residuum with which the radionuclides have had contact. Not all radionuclides, though, will be retained in the subsurface by adsorption, absorption, or ion exchange. Among those radioactive contaminants that may be problematical with respect to trench burial at Oak Ridge are tritium and other negatively-charged nuclides, positively-charged radionuclides included in some of the complexed molecules, radioactive ions that have chemical properties si

Webster, D. A.

1976-01-01

232

Photon-Electron Correlation in the Laboratory Testing of Electronic Components. Part II: Beam Conditioning and Diagnostics.  

National Technical Information Service (NTIS)

The work described covers the Sandia National Laboratories (SNL) contributions to an experimental investigation performed jointly with the Defense Nuclear Agency (DNA) and the United Kingdom's Atomic Weapons Research Establishment (AWRE). The objectives o...

L. D. Posey W. Beezhold

1981-01-01

233

Snap-frozen brain tissue sections stored with desiccant at ambient laboratory conditions without chemical fixation are resistant to degradation for a minimum of 6 months.  

PubMed

Cryosectioned tissues from snap-frozen samples offer the advantage of preserving proteins at the cellular and subcellular levels and maintaining overall cell integrity in the tissue of interest without the use of chemical fixatives. To prevent specific or nonspecific degradation of proteins by autolytic and/or proteolytic processes, it is common practice to immediately store frozen tissue sections obtained from a cryostat under cryogenic conditions, for example -80 degrees C. Our laboratory recently challenged this widely held belief by extracting proteins from brain tissue samples that were archived for 1 day, 1 week, 1 month, and 6 months at various storage conditions (frozen, ambient, or desiccated) without the use of chemical fixatives. Our results from immunofluorescent stains, immunoperoxidase stains, silver stains, and Western blot analyses demonstrated that snap-frozen, heat-dried tissue sections stored and desiccated at ambient laboratory conditions are comparable to frozen samples stored up to 6 months. PMID:19521279

Sadler, Theodore R; Khodavirdi, Ani C; Hinton, David R; Holschneider, Daniel P

2009-03-01

234

Ranking the significance of fermentation conditions on the volatile organic compounds of Tuber melanosporum fermentation system by combination of head-space solid phase microextraction and chromatographic fingerprint similarity analysis.  

PubMed

Tuber melanosporum is highly appreciated in culinary contexts due to its unique and characteristic aroma. T. melanosporum fermentation has been established as a promising alternative for fruiting bodies to produce volatile organic compounds (VOCs). In this work, a technique using a combination of chromatographic fingerprint similarity analysis, head-space solid phase microextraction and gas chromatography was developed to rank the significance of fermentation conditions on the VOCs profile during T. melanosporum fermentation. Omission tests indicated that the absence of major carbon source (i.e., sucrose) in the fermentation media had the most significant effect on the profile of VOCs, followed by the absence of yeast extract or peptone. Consideration of the culture conditions revealed that VOCs produced was the most significantly affected by temperature. These results indicated that it is possible to adjust the aroma of truffles via fermentation process control. PMID:23943007

Li, Dao-Cheng; Liu, Rui-Sang; Li, Hong-Mei; Yuan, Zhan-Peng; Chen, Tao; Tang, Ya-Jie

2014-03-01

235

Growth and nitrogen utilization in seedlings of mountain birch ( Betula pubescens ssp. tortuosa ?) as affected by ultraviolet radiation (UVA and UV-B) under laboratory and outdoor conditions  

Microsoft Academic Search

Growth patterns and nitrogen economy were studied in pot-grown seedlings of mountain birch subjected to different ultraviolet\\u000a radiation under both laboratory and outdoor conditions at Abisko in northern Sweden. In the laboratory, nutrient supply, temperature,\\u000a humidity, ultraviolet radiation-A (UV-A, 320–400 nm) and B (UV-B, 280–320 nm) were controlled, while photosynthetically active\\u000a radiation (PAR, 400–700 nm) and photoperiod varied naturally. Under

Martin Weih; Ulf Johanson; Dylan Gwynn-Jones

1998-01-01

236

Soil mercury and CO2 emissions and their relationship under controlled laboratory conditions: Effects of oxygen depletion and soil sterilization  

Microsoft Academic Search

Terrestrial carbon (C) pools play an important role in uptake, deposition, sequestration, and emission of atmospheric mercury (Hg). Thus, we investigated the fate of Hg during C mineralization processes using a laboratory flux set-up to evaluate to what degree decomposition of organic matter leads to emission and re- emission of Hg to the atmosphere, increased mobilization within terrestrial ecosystems, or

C. Berger; X. Fain; D. Obrist

2008-01-01

237

A Laboratory Exercise to Illustrate Increased Salivary Cortisol in Response to Three Stressful Conditions Using Competitive ELISA  

ERIC Educational Resources Information Center

Perceived stress activates the hypothalamus-pituitary-adrenal axis, resulting in the release of glucocorticoids into the systemic circulation. Glucocorticoids cause the elevation of blood glucose, providing the necessary energy for the organism to cope with stress. Here, we outline a laboratory exercise that uses a competitive ELISA kit to…

Haussmann, Mark F.; Vleck, Carol M; Farrar, Eugenia S.

2007-01-01

238

Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions  

NASA Technical Reports Server (NTRS)

The Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MSL-CETSOL and MICAST) are two investigations which supports research into metallurgical solidification, semiconductor crystal growth (Bridgman and zone melting), and measurement of thermo-physical properties of materials. This is a cooperative investigation with the European Space Agency (ESA) and National Aeronautics and Space Administration (NASA) for accommodation and operation aboard the International Space Station (ISS). Research Summary: Materials Science Laboratory - Columnar-to-Equiaxed Transition in Solidification Processing (CETSOL) and Microstructure Formation in Casting of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST) are two complementary investigations which will examine different growth patterns and evolution of microstructures during crystallization of metallic alloys in microgravity. The aim of these experiments is to deepen the quantitative understanding of the physical principles that govern solidification processes in cast alloys by directional solidification.

Gandin, Charles-Andre; Ratke, Lorenz

2008-01-01

239

Effect of co-applied cowdung and inorganic nitrogen on microbial respiration in soil under laboratory conditions  

Microsoft Academic Search

A laboratory incubation study was carried out for 8 weeks at 30°C to assess microbial respiration and nitrogen (N) transformation in a sandy loam, Iwo series (Oxic Tropudalf) amended with both inorganic N and cowdung. The treatments consisted of 3\\\\times 3 factorial combinations of manure and inorganic N. Cowdung rates were 0, 12, 24 t ha and rates of (NH4)2SO4 were 0,

Akinyemi Olayinka

2001-01-01

240

Flue gas conditioning for improved particle collection in electrostatic precipitators. First topical report, Results of laboratory screening of additives  

SciTech Connect

Several tasks have been completed in a program to evaluate additives to improve fine particle collection in electrostatic precipitators. Screening tests and laboratory evaluations of additives are summarized in this report. Over 20 additives were evaluated; four were found to improve flyash precipitation rates. The Insitec particle analyzer was also evaluated; test results show that the analyzer will provide accurate sizing and counting information for particles in the size range of {le} 10 {mu}m dia.

Durham, M.D.

1993-04-16

241

Characterisation of the biosand filter for E. coli reductions from household drinking water under controlled laboratory and field use conditions.  

PubMed

More than a billion people in the developing world lack access to safe and reliable sources of drinking water. Point of use (POU) household water treatment technology allows people to improve the quality of their water by treating it in the home. One emerging POU technology is the biosand filter (BSF), a household-scale, intermittently operated slow sand filter. Laboratory and field studies examined Escherichia coli reductions achieved by the BSF. During two laboratory studies, mean E. coli reductions were 94% and they improved over the period of filter use, reaching a maximum of 99%. Field analysis conducted on 55 household filters near Bonao, Dominican Republic averaged E. coli reductions of 93%. E. coli reductions by the BSF in laboratory and field studies were less than those typically observed for traditional slow sand filters (SSFs), although as for SSFs microbial reductions improved over the period of filter use. Further study is needed to determine the factors contributing to microbial reductions in BSFs and why reductions are lower than those of conventional SSFs. PMID:17037125

Stauber, C E; Elliott, M A; Koksal, F; Ortiz, G M; DiGiano, F A; Sobsey, M D

2006-01-01

242

Diurnal activity rhythms of the subterranean termite Anacanthotermes vagans (Hagen) under laboratory and field conditions of the Kuwait desert  

NASA Astrophysics Data System (ADS)

Daily foraging activity of Anacanthotermes vagans was tested using toilet paper rolls as bait. The highest activity was recorded at midnight and during the hours of the early morning in both summer and winter seasons. In spring the time of highest activity was reversed to take place at midday, afternoon and early evening. Aktograph records in the laboratory demonstrated that individual workers are active most of the day and not naturally entrianed by photoperiods. Daily activity of groups of 10 workers was not statistically different from that of individual workers.

Absuhama, Faysal T.; Al Houty, Wasmia A.

1989-03-01

243

ENHANCED THERMAL VACUUM TEST CAPABILITY FOR RADIOISOTOPE POWER SYSTEMS AT THE IDAHO NATIONAL LABORATORY BETTER SIMULATES ENVIRONMENTAL CONDITIONS OF SPACE  

SciTech Connect

The Idaho National Laboratory (INL) is preparing to fuel and test the Advanced Stirling Radioisotope Generator (ASRG), the next generation space power generator. The INL identified the thermal vacuum test chamber used to test past generators as inadequate. A second vacuum chamber was upgraded with a thermal shroud to process the unique needs and to test the full power capability of the new generator. The thermal vacuum test chamber is the first of its kind capable of testing a fueled power system to temperature that accurately simulate space. This paper outlines the new test and set up capabilities at the INL.

J. C. Giglio; A. A. Jackson

2012-03-01

244

Molluscicidal activities of six species of Bignoniaceae from north-eastern Brazil, as measured against Biomphalaria glabrata under laboratory conditions.  

PubMed

The molluscicidal profile and brine-shrimp bio-activity of the ethanolic extracts of plants from the Bignoniaceae family were determined. The six extracts investigated were of the stems of Melloa quadrivalvis and Tabebuia aurea, and whole plants of Adenocalymma comosum, Arrabidaea parviflora, Cuspidaria argentea and Clytostoma binatum. When tested in the laboratory, with Biomphalaria glabrata as the test snail, all six extracts gave median lethal concentrations (9-54 microg/ml) that fell well below the upper threshold, of 100 mug/ml, set for a potential molluscicide by the World Health Organization. PMID:17524251

Silva, T M S; Da Silva, T G; Martins, R M; Maia, G L A; Cabral, A G S; Camara, C A; Agra, M F; Barbosa-Filho, J M

2007-06-01

245

Features of similarity  

Microsoft Academic Search

Questions the metric and dimensional assumptions that underlie the geometric representation of similarity on both theoretical and empirical grounds. A new set-theoretical approach to similarity is developed in which objects are represented as collections of features and similarity is described as a feature-matching process. Specifically, a set of qualitative assumptions is shown to imply the contrast model, which expresses the

Amos Tversky

1977-01-01

246

Biofilm Formation by Gram-Negative Bacteria on Central Venous Catheter Connectors: Effect of Conditioning Films in a Laboratory Model  

Microsoft Academic Search

Human blood components have been shown to enhance biofilm formation by gram-positive bacteria. We investigated the effect of human blood on biofilm formation on the inner lumen of needleless central venous catheter connectors by several gram-negative bacteria, specifically Enterobacter cloacae, Pseudomonas aerugi- nosa, and Pantoea agglomerans. Results suggest that a conditioning film of blood components promotes biofilm formation by these

R. Murga; J. M. Miller; R. M. Donlan

2001-01-01

247

Predictions of NOX in a Laboratory Pulverized Coal Combustor Operating under Air and Oxy-Fuel Conditions  

Microsoft Academic Search

A new approach to modeling NOX under oxy-fuel combustion conditions in a simple staged-oxidizer flow field is presented. The approach is centered on the combination of devolatilization and char oxidation models with a detailed kinetic mechanism for light hydrocarbon combustion. NOX chemistry is included by the user's selection of the detailed mechanism, while the devolatilization model consists of the chemical

Andrew J. Mackrory; Dale R. Tree

2009-01-01

248

Self-similar factor approximants.  

PubMed

The problem of reconstructing functions from their asymptotic expansions in powers of a small variable is addressed by deriving an improved type of approximants. The derivation is based on the self-similar approximation theory, which presents the passage from one approximant to another as the motion realized by a dynamical system with the property of group self-similarity. The derived approximants, because of their form, are called self-similar factor approximants. These complement the obtained earlier self-similar exponential approximants and self-similar root approximants. The specific feature of self-similar factor approximants is that their control functions, providing convergence of the computational algorithm, are completely defined from the accuracy-through-order conditions. These approximants contain the Padé approximants as a particular case, and in some limit they can be reduced to the self-similar exponential approximants previously introduced by two of us. It is proved that the self-similar factor approximants are able to reproduce exactly a wide class of functions, which include a variety of nonalgebraic functions. For other functions, not pertaining to this exactly reproducible class, the factor approximants provide very accurate approximations, whose accuracy surpasses significantly that of the most accurate Padé approximants. This is illustrated by a number of examples showing the generality and accuracy of the factor approximants even when conventional techniques meet serious difficulties. PMID:12636750

Gluzman, S; Yukalov, V I; Sornette, D

2003-02-01

249

Practice with Similarity Proofs  

NSDL National Science Digital Library

In this worksheet of eight questions, students practice their knowledge of similarity proofs. In the first four questions, students determine which postulate or theorem works to prove triangle similarity - AA, SAS, or SSS. In the last four questions, students are asked to work through the proof of various problems. The answers are embedded in the page, and this is a helpful resource for students to work with similarity proofs.

Roberts, Donna

2000-01-01

250

The merits of designed ELISA avidity kit in detection of Toxoplasma gondii IgG antibody in laboratory conditions  

PubMed Central

Background: Toxoplasmosis is a parasitic disease which may cause some laboratory symptoms in infected individuals. One of the main ways to transmit this organism is placenta to the fetus pathway. If this transmission occurs in the 3rd month of pregnancy, the abortion, central nerve system and ocular disorder will happen. Because of this issue, the precise technique for the detection of Toxoplasma antibodies such as immunoglobulin G (IgG) and immunoglobulin M IgM are important, as they contain ELISA and ELISA avidity. Materials and Methods: In this survey, the main samples are serum and amniotic fluid that were collected from 48 pregnant women infected with Toxoplasma gondii in Shariaty hospital. This survey is attempted to design ELISA avidity kit in Tarbiat Modates University. Results: The results from this survey show that, in these total pregnant women the infection by T. gondii has occurred and many of them are infected currently. Conclusions: In the simple ELISA technique, the only antibody that can be detected precisely is IgM; however, using this technique the IgG antibody can also be detected. In this new technique or ELISA avidity, in addition to detection of IgG antibody against T. gondii, the month of transmission of Toxoplasma is also interpreted.

Sadraie, Javid; Bahadory, Ehsan Shariat; Marsusi, Vajihe

2013-01-01

251

Laboratory Measurements of the 5-20 cm Wavelength Opacity of Ammonia Pressure-Broadened by Methane under Jovian Conditions  

NASA Astrophysics Data System (ADS)

In order to fully understand the role methane (CH4) plays in the microwave emission spectra of the deep atmospheres of the outer planets, over 280 laboratory measurements of the opacity of ammonia in a methane environment have been made in the 5-20 cm wavelength range. All opacity measurements were made with either 100 or 200 mbars of ammonia and with 1 to 3 bars of added methane in the 330-450K temperature range. A formalism for the absorptivity of ammonia broadened by methane has now been developed and had been applied to the Hanley et al. (Icarus, v. 202, 2009) model for the opacity of ammonia. Due to methane’s relatively low abundance at Jupiter ( 0.2% by volume), its effect on the microwave spectrum which will be observed by the Juno MWR (Microwave Radiometer) will be minimal. However, these experimental results will significantly improve the understanding of the microwave emission spectrum of Uranus and Neptune where methane plays a more dominant role. This work was supported by NASA Contract NNM06AA75C from Marshall Space Flight Center supporting the Juno Mission Science Team, under Subcontract 699054X from the Southwest Research Institute.

Chinsomboon, Garrett; Steffes, P. G.

2012-10-01

252

Performance of a laboratory-scale membrane bioreactor consisting mixed liquor with aquatic worms under toxic conditions.  

PubMed

A laboratory scale membrane bioreactor (MBR) consisting of worms was operated for 214days. The objective was to evaluate the treatment and operating performance of the MBR with and without the addition of Ametryn which is a toxic and persistent herbicide. Removal of Ametryn was doubled (up to 80%) in the MBR when the worms were present. Increased rate (2.5kPa/day) of trans-membrane pressure (TMP) and low concentration of MLSS (5.5g/L) were recorded when the worm population was high (80-100 worms per 70?L). Short-term critical flux values were increased from 7.5 to 15 and then to 30L/m(2)/h when the worm numbers decreased from 90 to 35 and then to 18 per 70?L of mixed liquor respectively. Further, high levels of carbohydrate concentration of soluble microbial products (SMP) and smaller sludge floc-sizes were found when the worm numbers were high. PMID:24413480

Navaratna, Dimuth; Shu, Li; Jegatheesan, Veeriah

2014-03-01

253

Laboratory measurements of the microwave opacity of gaseous ammonia (NH3) under simulated conditions for the Jovian atmosphere  

NASA Technical Reports Server (NTRS)

Microwave opacity measurements have been conducted for gaseous ammonia simulating Jovian atmosphere conditions at five frequencies from 18.5 to 1.38 cm, at temperatures from 178 to 300 K and 1-6 atm pressures. The atmospheric composition is 90-percent H/10-percent He. In the 1.38-18.5 cm wavelength range, ammonia absorption is well expressed by Berge and Gulkis' (1976) lineshape. The results obtained suggest that either an ammonia abundance 1.5-2.0 times greater than solar must be present at less than 1-2 bar, or some other microwave absorber is present.

Steffes, Paul G.; Jenkins, Jon M.

1987-01-01

254

Role of microorganisms in emission of nitrous oxide and methane in pulse cultivated soil under laboratory incubation condition.  

PubMed

Soil from a pulse cultivated farmers land of Odisha, India, have been subjected to incubation studies for 40 consecutive days, to establish the impact of various nitrogenous fertilizers and water filled pore space (WFPS) on green house gas emission (N2O & CH4). C2H2 inhibition technique was followed to have a comprehensive understanding about the individual contribution of nitrifiers and denitrifiers towards the emission of N2O. Nevertheless, low concentration of C2H2 (5 ml: flow rate 0.1 kg/cm(2)) is hypothesized to partially impede the metabolic pathways of denitrifying bacterial population, thus reducing the overall N2O emission rate. Different soil parameters of the experimental soil such as moisture, total organic carbon, ammonium content and nitrate-nitrogen contents were measured at regular intervals. Application of external N-sources under different WFPS conditions revealed the diverse role played by the indigenous soil microorganism towards green house gas emission. Isolation of heterotrophic microorganisms (Pseudomonas) from the soil samples, further supported the fact that denitrification might be prevailing during specific conditions thus contributing to N2O emission. Statistical analysis showed that WFPS was the most influential parameter affecting N2O formation in soil in absence of an inhibitor like C2H2. PMID:24426084

Jena, Jyotsnarani; Ray, Sanak; Srichandan, Haragobinda; Das, Anuradha; Das, Trupti

2013-03-01

255

Intercomparison exercise on external gamma dose rate under field conditions at the laboratory of natural radiation (Saelices el Chico, Spain).  

PubMed

The last nuclear accident in Fukushima nuclear power plant has increased the necessity for measuring radiation in the environment. Therefore, radiation monitors providing results traceable throughout the country become essential and it is very important to test them under the same environmental conditions. The first intercomparison of natural radioactivity under field conditions was held in Saelices el Chico (Salamanca, Spain) in May 2011, including an exercise on environmental dose rate. This article presents the results achieved by 19 instruments belonging to 12 institutions from 7 different countries. The tested detectors are proportional counters, ionisation chambers, Geiger-Müller and scintillators measuring dose rate in three stations with reference values from 110 to 1800 nGy h(-1). All the results were given in terms of air kerma (nGy h(-1)) and the measurements show agreement within 25 % in all the sites. Evaluation criteria based on accuracy and statistical uncertainty were also carried out and 25 % of participants passed the test in all sites. PMID:23413092

Gutierrez-Villanueva, J L; Sainz-Fernández, C; Fuente-Merino, I; Sáez-Vergara, J C; Correa-Garcés, E; Quindos-Poncela, L S

2013-08-01

256

Laboratory measurements of the microwave properties of H2S under simulated Jovian conditions with an application to Neptune  

NASA Technical Reports Server (NTRS)

H2S opacity may significantly affect the brightness temperatures of Uranus and Neptune due to possible depletion of ammonia in the tropospheres of those planets (de Pater et al. 1991). Though the rotational line centers of H2S are in the millimeter wavelengths region, significant absorption is also present at centimeter wavelengths due to pressure broadening of the lines. Accordingly, the properties of H2S under Jovian conditions have been measured in order to constrain further the constituents' abundances on these planets. These absorptivity measurements show values that are significantly greater than values predicted by the Van Vleck-Weisskopf models traditionally used at centimeter wavelengths. In order to better model the opacity due to H2S under Jovian conditions a Ben-Reuven lineshape formalism has therefore been developed and is presented. This formalism provides a possible constraint on the relative abundances of H2S and NH3 on Neptune based on Voyager 2 radio occultation results (Lindal 1992).

Deboer, David R.; Steffes, Paul G.

1994-01-01

257

Evaluation of the low tension flood process for high-salinity reservoirs--laboratory investigation under reservoir conditions  

SciTech Connect

In northwest Germany, oil reservoirs are characterized by high-salinity brines with up to 23% TDS. For such salinity conditions, fatty alcohol derivatives with 4.5 ethene oxide (EO) units were found to lower the interfacial tension (IFT) drastically and to mobilize residual oil almost completely. Intensive flood experiments under reservoir conditions with the use of sandpacks 2 m in length allowed optimizing the low-tension process for an oil field that was considered a possible candidate. A combination of surfactant slug followed by a tailored mobility buffer showed best results in terms of additional oil recovery and process duration. A preflush of low-concentration aqueous polymer solution brought a decisive further increase in additional oil recovery. Results obtained for the slug process indicated that variables such as IFT, surfactant concentration, flooding velocity, and pressure gradient influence the low-tension process in a combined manner. Oil produced in the oil bank showed alteration in properties, compared with the oil used to saturate the pore space.

Murtada, H.; Marx, C.

1982-12-01

258

Short-term evaluation of visible implant alpha tags in juveniles of three fish species under laboratory conditions.  

PubMed

Visible implant alpha (VI alpha) tag-induced changes in mortality and condition, as well as tag retention and readability, were examined during a 4-week period for juveniles of three fish species: tiger muskellunge Esox masquinongy × Esox lucius (91?±?7?mm total length, L(T), mean?±?s.d.), Snake River cutthroat trout Oncorhynchus clarki behnkei (84?±?8?mm) and rainbow trout Oncorhynchus mykiss (85?±?5?mm). Mortality and condition did not differ between tagged fish and control fish for any species and overall tag retention rates were high (92% for E. masquinongy × E. lucius, 91% for O. c. behnkei and 100% for O. mykiss). Short-term readability of VI alpha tags was low in juvenile E. masquinongy × E. lucius and juvenile O. c. behnkei. Therefore, it is not recommend to use VI alpha tags in juvenile E. masquinongy × E. lucius or juvenile O. c. behnkei for periods >2?weeks, but VI alpha tags seem to be suitable for juvenile O. mykiss for a period of at least 4?weeks. PMID:24689672

Turek, K C; Pegg, M A; Pope, K L

2014-04-01

259

Toxicity of the herbicide glufosinate-ammonium to predatory insects and mites of Tetranychus urticae (Acari: Tetranychidae) under laboratory conditions.  

PubMed

The toxicities of the herbicide glufosinate-ammonium to three predatory insect and two predatory mite species of Tetranychus urticae Koch were determined in the laboratory by the direct contact application. At a concentration of 540 ppm (a field application rate for weed control in apple orchards), glufosinate-ammonium was almost nontoxic to eggs of Amblyseius womersleyi Schicha, Phytoseiulus persimilis Athias-Henriot, and T. urticae but highly toxic to nymphs and adults of these three mite species, indicating that a common mode of action between predatory and phytophagous mites might be involved. In tests with predatory insects using 540 ppm, glufosinate-ammonium revealed little or no harm to larvae and pupae of Chrysopa pallens Rambur but was slightly harmful to eggs (71.2% mortality), nymphs (65.0% mortality), and adults (57.7% mortality) of Orius strigicollis Poppius. The herbicide showed no direct effect on eggs and adults of Harmonia axyridis (Pallas) but was harmful, slightly harmful, and harmless to first instars (100% mortality), fourth instars (51.1% mortality), and pupae (24.5% mortality), respectively. The larvae and nymphs of predators died within 12 h after treatment, suggesting that the larvicidal and nymphicidal action may be attributable to a direct effect rather than an inhibitory action of chitin synthesis. On the basis of our data, glufosinate-ammonium caused smaller effects on test predators than on T. urticae with the exception of P. persimilis, although the mechanism or cause of selectivity remains unknown. Glufosinate-ammonium merits further study as a key component of integrated pest management. PMID:11233107

Ahn, Y J; Kim, Y J; Yoo, J K

2001-02-01

260

Eta Carinae: An Astrophysical Laboratory to Study Conditions During the Transition Between a Pseudo-Supernova and a Supernova  

NASA Astrophysics Data System (ADS)

A major puzzle in the studies of supernovae is the pseudo-supernova, or the near-supernovae state. It has been found to precede, in timespans ranging from months to years, a number of recently-detected distant supernovae. One explanation of these systems is that a member of a massive binary underwent a near-supernova event shortly before the actual supernova phenomenon. Luckily, we have a nearby massive binary, Eta Carinae, that provides an astrophysical laboratory of a near-analog. The massive, highly-eccentric, colliding-wind binary star system survived a non-terminal stellar explosion in the 1800's, leaving behind the incredible bipolar, 10"x20" Homunculus nebula. Today, the interaction of the binary stellar winds 1") is resolvable by the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). Using HST/STIS, several three-dimensional (3D) data cubes (2D spatial, 1D velocity) have been obtained at selected phases during Eta Carinae's 5.54-year orbital cycle. The data cubes were collected by mapping the central 1-2" at 0.05" intervals with a 52"x0.1" aperture. Selected forbidden lines, that form in the colliding wind regions, provide information on electron density of the shocked regions, the ionization by the hot secondary companion of the primary wind and how these regions change with orbital phase. By applying various analysis techniques to these data cubes, we can compare and measure temporal changes due to the interactions between the two massive winds. The observations, when compared to current 3D hydrodynamic models, provide insight on Eta Carinae's recent mass-loss history, important for determining the current and future states of this likely nearby supernova progenitor.

McKinnon, Darren; Gull, T. R.; Madura, T.

2014-01-01

261

Effect of triflumuron, a chitin synthesis inhibitor, on Aedes aegypti, Aedes albopictus and Culex quinquefasciatus under laboratory conditions  

PubMed Central

Background Resistance to traditional insecticides represents a threat to the control of disease vectors. The insect growth regulators (IGR) are a potential alternative to control mosquitoes, including resistant populations. The chitin synthesis inhibitors (CSI) are IGRs, which interfere with the insect molting process and represent one major class of compounds against Aedes aegypti populations resistant to the larvicide organophosphate temephos. In the present study, we evaluated the efficacy of the CSI triflumuron on Culex quinquefasciatus, Aedes albopictus and against several Ae. aegypti field populations. Methods The efficacy of triflumuron, against Cx. quinquefasciatus and Ae. albopictus was evaluated with laboratory strains through dose–response assays. Additionaly, this CSI was tested against seven Ae. aegypti field populations exhibiting distinct resistance levels to both temephos and the pyrethroid deltamethrin. Aedes aegypti populations were exposed to both a dose that inhibits 99% of the adult emergence of mosquitoes from the susceptible reference strain, Rockefeller, (EI99?=?3.95??g/L) and the diagnostic dose (DD), corresponding to twice the EI99. Results Our results indicate that triflumuron was effective in emergence inhibition (EI) of Cx. quinquefasciatus (EI50= 5.28??g/L; EI90= 12.47??g/L) and Ae. albopictus (EI50= 1.59??g/L; EI90= 2.63??g/L). Triflumuron was also effective against seven Ae. aegypti Brazilian populations resistant to both temephos and deltamethrin. Exposure of all the Ae. aegypti populations to the triflumuron EI99 of the susceptible reference strain, Rockefeller, resulted in complete inhibition of adult emergence, suggesting no cross-resistance among traditional insecticides and this CSI. However, a positive correlation between temephos resistance and tolerance to triflumuron was observed. Conclusion The results suggest that triflumuron represents a potential tool for the control of disease vectors in public health. Nevertheless, they point to the need of constant monitoring of the susceptibility status of vector populations to CSIs.

2013-01-01

262

Mathematical prediction of imidacloprid persistence in two Croatian soils with different texture, organic matter content and acidity under laboratory conditions.  

PubMed

In the present laboratory study, persistence of imidacloprid (IMI) as a function of initial insecticide concentration and soil properties in two Croatian soils (Krk sandy clay and Istria clay soils) was studied and described mathematically. Upon fitting the obtained experimental data for the higher concentration level (5 mg/kg) to mathematical models, statistical parameters (R (2), scaled root mean squared error and ? (2) error) indicated that the single first-order kinetics model provided the best prediction of IMI degradation in the Krk sandy clay soil, while in the Istria clay soil biphasic degradation was observed. At the lower concentration level (0.5 mg/kg), the biphasic models Gustafson and Holden models as well as the first-order double exponential model fitted the best experimental data in both soils. The disappearance time (DT50) values estimated by the single first-order double exponential model (from 50 to 132 days) proved that IMI can be categorized as a moderately persistent pesticide. In the Krk sandy clay soil, resulting DT50 values tended to increase with an increase of initial IMI concentration, while in the Istria clay soil, IMI persistence did not depend on the concentration. Organic matter of both experimental soils provided an accelerating effect on the degradation rate. The logistic model demonstrated that the effect of microbial activity was not the most important parameter for the biodegradation of IMI in the Istria clay soil, where IMI degradation could be dominated by chemical processes, such as chemical hydrolysis. The results pointed that mathematical modeling could be considered as the most convenient tool for predicting IMI persistence and contributes to the establishment of adequate monitoring of IMI residues in contaminated soil. Furthermore, IMI usage should be strictly controlled, especially in soils with low organic matter content where the risk of soil and groundwater contamination is much higher due to its longer persistence and consequent leaching and/or moving from soil surface prior to its degradation. PMID:23998302

Brozni?, Dalibor; Milin, ?edomila

2013-01-01

263

Similarities between rarefaction methods  

Microsoft Academic Search

The number of species in a community is one of the most commonly used measures of diversity. This measure is, however, affected by sample size. The rarefaction method attempts to correct sample size bias by assuming an underlying sampling model. Several rarefaction models are shown to be similar analytically. This similarity holds not only for the expected number of species

Eric P. Smith; Paul M. Stewart; John Cairns

1985-01-01

264

3D Shape Similarity.  

National Technical Information Service (NTIS)

We study the 3D shape similarity between closed surfaces. We represent a curved or polyhedral 3D object of genus zero using a mesh representation that has nearly uniform distribution with known connectivity among mesh nodes. We define a shape similarity m...

H. Y. Shum M. Hebert K. Ikeuchi

1995-01-01

265

Similarity spectra analysis of high-performance jet aircraft noise.  

PubMed

Noise measured in the vicinity of an F-22A Raptor has been compared to similarity spectra found previously to represent mixing noise from large-scale and fine-scale turbulent structures in laboratory-scale jet plumes. Comparisons have been made for three engine conditions using ground-based sideline microphones, which covered a large angular aperture. Even though the nozzle geometry is complex and the jet is nonideally expanded, the similarity spectra do agree with large portions of the measured spectra. Toward the sideline, the fine-scale similarity spectrum is used, while the large-scale similarity spectrum provides a good fit to the area of maximum radiation. Combinations of the two similarity spectra are shown to match the data in between those regions. Surprisingly, a combination of the two is also shown to match the data at the farthest aft angle. However, at high frequencies the degree of congruity between the similarity and the measured spectra changes with engine condition and angle. At the higher engine conditions, there is a systematically shallower measured high-frequency slope, with the largest discrepancy occurring in the regions of maximum radiation. PMID:23556581

Neilsen, Tracianne B; Gee, Kent L; Wall, Alan T; James, Michael M

2013-04-01

266

Interactions between bacteria and Cryptosporidium molnari in gilthead sea bream (Sparus aurata) under farm and laboratory conditions.  

PubMed

The possible interaction of Cryptosporidium molnari and bacteria in gilthead sea bream (Sparus aurata) was studied. Epidemiological data from a pathological survey under farm conditions were analyzed. In addition, parasite and bacteria burdens were studied in experimental models in which naturally and experimentally parasitized fish were challenged with a particular strain of Vibrio harveyi (H57). All the bacteria species present were studied. Under farm conditions, the parasite was more prevalent when mortality or morbidity cases (study C) occurred than in randomly sampled fish (study B). In study C, parasite abundance was significantly higher in bacteria-negative fish, and total bacteria abundance was significantly higher within non-parasitized fish. V. harveyi and V. splendidus were the most prevalent among bacteria carriers in studies B and C, respectively. In study C, among bacteria carriers, most isolates were slightly more prevalent in parasitized than in non-parasitized fish. Two groups (G1, G2) of naturally parasitized fish were inoculated with H57 by intracoelomic injection (ICI) and by oral intubation (OI). H57 was recovered only in G1 inoculated fish, which had a significantly higher basal abundance of total bacteria, and where the only ones with mortalities. In G1, the mortality rate and the prevalence of other V. harveyi strains different from the H57 molecular type were higher in ICI than in OI fish, and the total bacteria abundance was also significantly higher in ICI fish. C. molnari abundance was significantly higher in G1 than in G2, and also in OI than in ICI fish within G1. When H57 was IC inoculated to fish (G3, from the same farm as G2) experimentally infected with C. molnari, H57 was not recovered from any fish. A low mortality was recorded, and only in those fish inoculated with both pathogens. Also in these fish, the prevalence of infection of C. molnari was higher and histopathological damage to the stomach was greater than in fish inoculated only with the parasite. Therefore, the impact of the parasite would be reduced notably when the bacterial burden or the intensity of parasite infection are low (G2, G3). PMID:16934406

Sitjà-Bobadilla, A; Pujalte, M J; Macián, M C; Pascual, J; Alvarez-Pellitero, P; Garay, E

2006-12-20

267

Evaluation of the biocompatibility of NiTi dental wires: A comparison of laboratory experiments and clinical conditions.  

PubMed

Effects of intraoral environment on the surface degradation of nickel-titanium (NiTi) shape memory alloy orthodontic wires was simulated through ex situ static immersion experiments in artificial saliva. The tested wires were compared to companion wires retrieved from patients in terms of chemical changes and formation of new structures on the surface. Results of the ex situ experiments revealed that the acidic erosion effective at the earlier stages of immersion led to the formation of new structures as the immersion period approached 30days. Moreover, comparison of these results with the analysis of wires utilized in clinical treatment evidenced that ex situ experiments are reliable in terms predicting C-rich structure formation on the wire surfaces. However, the formation of C pileups at the contact sites of arch wires and brackets could not be simulated with the aid of static immersion experiments, warranting the simulation of the intraoral environment in terms of both chemical and physical conditions, including mechanical loading, when evaluating the biocompatibility of NiTi orthodontic arch wires. PMID:24857476

Toker, S M; Canadinc, D

2014-07-01

268

Laboratory Measurements of the W-band (3.2 mm) Properties of Phosphine (PH3) and Ammonia (NH3) Under Simulated Conditions for the Outer Planets  

NASA Astrophysics Data System (ADS)

A model, based on the Van Vleck-Weisskopf lineshape, was developed for the centimeter-wavelength opacity of PH3, which provides an order of magnitude improvement over previous models (Hoffman et al. ICARUS 152, 172-184, 2001). This formalism utilizes line intensities from the JPL (Pickett et al. 1998) catalog which have been selectively weighted to fit the centimeter wavelength laboratory data. The collisionally induced rotational lines which are lower in frequency than the first rotational line of J = 1 to 0 (267 GHz) have not been measured directly, thus in order to fit the data, weightings were given to those lines below 40 GHz. New laboratory measurements are currently being conducted to investigate whether this model is also accurate at 94 GHz (3.2 mm) under conditions for the outer planets. Preliminary measurements at room temperature agree well with this centimeter-wave formalism for PH3 opacity suggesting that the intensities of only the first 40 lines of the JPL catalog need to be weighted. Further measurements of the opacity and refractivity of PH3 in a hydrogen/helium (H2/He) atmosphere are being conducted at 94 GHz (3.2 mm) at pressures of 0.5, 1 and 2 bars and at temperatures of 210 K and 193 K. Additionally, new high-precision laboratory measurements of the opacity and refractivity of NH3 in an H2/He atmosphere will be conducted under the same frequency, temperature and pressure conditions described for PH3. These new measurements will better constrain the NH3 opacity model for use over a broader wavelength range. Results of measurements of both PH3 and NH3 can be used to better interpret maps of Saturn's emission at this wavelength and can potentially deduce spatial variations in the abundances of both gases in the atmosphere of Saturn. This work is supported by the NASA Planetary Atmospheres Program under grant NAG5-12122.

Mohammed, P. N.; Steffes, P. G.

2003-05-01

269

Gender similarities and differences.  

PubMed

Whether men and women are fundamentally different or similar has been debated for more than a century. This review summarizes major theories designed to explain gender differences: evolutionary theories, cognitive social learning theory, sociocultural theory, and expectancy-value theory. The gender similarities hypothesis raises the possibility of theorizing gender similarities. Statistical methods for the analysis of gender differences and similarities are reviewed, including effect sizes, meta-analysis, taxometric analysis, and equivalence testing. Then, relying mainly on evidence from meta-analyses, gender differences are reviewed in cognitive performance (e.g., math performance), personality and social behaviors (e.g., temperament, emotions, aggression, and leadership), and psychological well-being. The evidence on gender differences in variance is summarized. The final sections explore applications of intersectionality and directions for future research. PMID:23808917

Hyde, Janet Shibley

2014-01-01

270

Genetic Similarities in Marriage  

MedlinePLUS Videos and Cool Tools

... high-tech investigation that set out to examine DNA samples obtained from 825 married couples. Ultimately, 1. ... college background, than they are to share similar DNA. I'm Dr. Cindy Haines of HealthDay TV, ...

271

Laboratory-scale interaction between CO2-rich brine and limestone and sandstone under supercritical CO2 conditions  

NASA Astrophysics Data System (ADS)

A test site for a prospective CO2 geological storage is situated in Hontomín (Burgos, northern Spain) with a reservoir rock that is composed of limestone (calcite) and sandstone (66 wt.% calcite, 28 wt.% quartz and 6 wt.% microcline). During and after CO2 injection, the resulting CO2-rich acid brine will likely promote the dissolution of carbonate minerals (calcite) and aluminosilicates (microcline). Since the reservoir Hontomín brine contains sulfate, gypsum (or anhydrite at depth) may precipitate. These coupled dissolution and precipitation reactions may induce changes in porosity and pore structure of the repository rocks. Percolations experiments with mechanically fractured cores (8.6 mm in diameter and 18 mm length) were performed under CO2 supercritical conditions (Pfluid = 150 bar; pCO2 ? 90 bar and T = 60 ºC) in order to evaluate and quantify variations in fracture permeability, preferential path formation and fracture volume. The brine sulfate content and the flow rate were varied. Regarding limestone, as the synthetic brines circulated through the fracture, the fracture permeability initially increased slowly, to thereafter increase rapidly. This change was due to a localized dissolution process (wormhole formation) along the core that occurred regardless gypsum precipitation. Nonetheless, the originated fracture volume in the sulfate-rich brine experiments was a factor of two smaller than that in sulfate-free brine experiments. Also, an increase in flow rate from 0.2 to 60 mL/h increased the volume of both dissolved calcite and precipitated gypsum. Regarding sandstone, permeability increased gradually with time. Nonetheless, this increase was not always continuous due to eventual fracture clogging. Formation of wormholes was observed. Acknowledgements This study was financed by CIUDEN (Ciudad de la Energía), the Compostilla OXYCFB300 project and the PANACEA project (European Community's Seventh Framework Programme FP7/2007-2013 under grant agreement number 282900).

Garcia-Rios, Maria; Cama, Jordi; Luquot, Linda; Soler, Josep

2014-05-01

272

Laboratory and modeling studies on the effects of water and soot emissions and ambient conditions on the formation of contrail ice particles in the jet regime  

NASA Astrophysics Data System (ADS)

Contrails and contrail-induced cirrus clouds are identified as the most uncertain components in determining aviation impacts on global climate change. Parameters affecting contrail ice particle formation immediately after engine exit plane (<5 s in plume age) may be critical to ice particle properties used in large scale models predicting contrail radiative forcing. Despite this, detailed understanding of these parametric effects is still limited. In this paper, we present results from recent laboratory and modeling studies conducted to investigate the effects of water and soot emissions and ambient conditions on the near-field formation of contrail ice particles. The Particle Aerosol Laboratory (PAL) at the NASA Glenn Research Center and the Aerodyne microphysical parcel model for contrail ice particle formation were employed. Our studies show that exhaust water concentrations have a significant impact on contrail ice particle formation. When soot was introduced, ice particle formation was observed only when exhaust water concentration was above a critical level. When no soot or sulfuric acid was introduced, homogeneous ice particle formation was unfavorable. Soot particles were found to compete for water vapor condensation, and higher soot concentrations emitted into the chamber resulted in smaller ice particles being formed. Chamber conditions corresponding to higher altitude standard day conditions were found to favor ice particle formation as expected. The microphysical model captures experimental trends well, but discrepancies between the model and the experiments exist as the model predicts narrower ice particle size distributions and ice particle sizes nearly a factor of two larger than measured. These discrepancies are likely due to the lack of treatment of turbulent mixing in the model and particle loss and scatter during the experimental sampling process. Future measurement activities are planned to investigate other important parameters, such as soot surface properties and sulfuric acid concentrations, using the PAL and microphysical model.

Wong, H.-W.; Beyersdorf, A. J.; Heath, C. M.; Ziemba, L. D.; Winstead, E. L.; Thornhill, K. L.; Tacina, K. M.; Ross, R. C.; Albo, S. E.; Bulzan, D. L.; Anderson, B. E.; Miake-Lye, R. C.

2011-09-01

273

Effectiveness of products from four locally grown plants for the management of Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boheman) (both Coleoptera: Bruchidae) in stored beans under laboratory and farm conditions in Northern Tanzania  

Microsoft Academic Search

The effectiveness of whole or powdered leaves (botanicals) from four locally grown plant species applied at a rate of 1.5kg per 100kg beans (Phaseolus vulgaris) against Acanthoscelides obtectus and Zabrotes subfasciatus was compared under laboratory and farm conditions. In the laboratory, Chenopodium ambrosioides, applied as powder or as whole leaves, was the most effective, with 100% mortality of adult insects

Ursula V. Paul; Juma S. Lossini; Peter J. Edwards; Angelika Hilbeck

2009-01-01

274

The Qualitative Similarity Hypothesis  

ERIC Educational Resources Information Center

Evidence is presented for the qualitative similarity hypothesis (QSH) with respect to children and adolescents who are d/Deaf or hard of hearing. The primary focus is on the development of English language and literacy skills, and some information is provided on the acquisition of English as a second language. The QSH is briefly discussed within…

Paul, Peter V.; Lee, Chongmin

2010-01-01

275

Additive similarity trees  

Microsoft Academic Search

Similarity data can be represented by additive trees. In this model, objects are represented by the external nodes of a tree, and the dissimilarity between objects is the length of the path joining them. The additive tree is less restrictive than the ultrametric tree, commonly known as the hierarchical clustering scheme. The two representations are characterized and compared. A computer

Shmuel Sattath; Amos Tversky

1977-01-01

276

The Google Similarity Distance  

Microsoft Academic Search

Words and phrases acquire meaning from the way they are used in society, from their relative semantics to other words and phrases. For computers the equivalent of 'society' is 'database,' and the equivalent of 'use' is 'way to search the database.' We present a new theory of similarity between words and phrases based on information distance and Kolmogorov complexity. To

Rudi L. Cilibrasi; Paul M. B. Vitányi

2007-01-01

277

The effect of different proportions of males and females over the Chrysomya albiceps (Wiedemann 1819) (Diptera, calliphoridae) biotic potential and longevity under laboratory conditions.  

PubMed

Chrysomya albiceps specimens were derived from colonies kept under laboratory conditions. The oviposition period, total number of eggs-mass and the weight of the eggs-mass (average/female) presented significant differences between colonies regarding the sexual ratio of 1 male/1 female (situation 1), when compared to the other ratios (1 male/3 female, situation II), (1 male/5 female, situation III), (3 male/1 female, situation IV) and (5 male/1 female, situation V). It was ascertained that the increase in the proportion of females, resulted in higher weight and greater number of ovipositions and lengthening of the period of oviposition, leads to a decrease in their lifespan. PMID:8736099

de Carvalho Queiroz, M M; de Mello, R P; da Serra Freire, N M

1996-01-01

278

Effects of Bacillus thuringiensis Cry toxins on developmental and reproductive characteristics of the predator Orius albidipennis (Hemiptera: Anthocoridae) under laboratory conditions.  

PubMed

The effects of Cry toxins from Bacillus thuringiensis (Berliner) (Bt) on the anthocorid Orius albidipennis Reuter were studied under laboratory conditions. Tritrophic experiments were performed, in which Orius nymphs were fed Helicoverpa armigera (Hübner) larvae reared on a diet with Cry1Ac, Cry1Ab, or Cry2Ab toxins at different concentrations (0, 1, and 10 microg/ml), when supplemented with Ephestia kuehniella Zeller eggs. In complementary experiments, the Bt Cry1Ac toxin was directly fed to Orius nymphs at a very high concentration (1 mg/ml). No effects on prey consumption, developmental time, nymph survival, fecundity, and egg hatching of O. albidipennis were found in either experiment. It can be concluded that the toxins tested do not seem to pose a risk for the anthocorid O. albidipennis, especially when it is exposed through the prey. PMID:18284750

González-Zamora, J E; Camúñez, S; Avilla, C

2007-10-01

279

Models for the Centimeter-Wavelength Opacity of Sulfur Dioxide and Carbon Dioxide based on Laboratory Measurements Conducted under Simulated Conditions for the Deep Atmosphere of Venus  

NASA Astrophysics Data System (ADS)

In the past two decades, multiple observations of Venus have been made at X band (3.6 cm) using the Jansky Very Large Array (VLA), and maps have been created of the 3.6 cm emission from Venus. Since the emission morphology is related both to surface features and to deep atmospheric absorption from CO2 and SO2 (see, e.g., Butler et al., Icarus 154, 2001), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide atmosphere under conditions for the deep atmosphere of Venus is required for proper interpretation. Initial measurements of the centimeter-wavelength (3.7-20 cm) of SO2 and CO2 under simulated conditions for the deep atmosphere of Venus, conducted using a new high-pressure system operating at 430 K and at pressures up to 92 Bars, were presented by Steffes and Barisich (DPS-2012, B.A.A.S., v.44, p.241). Over the past year, we have completed this measurement campaign for temperatures up to 550 K, so as to better understand the effects of SO2 and CO2 on the microwave emission from the Venus boundary layer. Results indicate that the model for the centimeter-wavelength opacity from pure CO2 (developed over 40 years ago -- Ho et al., JGR 71, 1966), is valid over the entire centimeter-wavelength range under simulated conditions for the deep atmosphere of Venus. Additionally, the laboratory results indicate that the model for the centimeter-wavelength opacity of SO2 in a CO2 atmosphere from Suleiman et al. (JGR-Planets, 101, Feb. 1996) can reliably be used under conditions of the deep atmosphere of Venus with the modifications described in this paper . This work is supported by the NASA Planetary Atmospheres Program under Grant NNX11AD66G.

Steffes, Paul G.; Shahan, P. M.

2013-10-01

280

High-resolution monitoring of root water uptake dynamics in laboratory conditions using full-wave inversion of near-field radar  

NASA Astrophysics Data System (ADS)

Root water uptake dynamics at local scale can be studied in laboratory conditions by growing plants in rhizotron containing sand and by imaging the water content evolution of the medium using light transmission. This technique allows to retrieve the water content with high resolution but cannot be applied in opaque media such as leaf-mold or clay, which is a major limitation for more realistic applications. Recently, ground-penetrating radar (GPR) has proven to be one of the most promising techniques for high-resolution digital soil mapping at the field scale. Particularly, by using full-wave inverse modeling of near-field GPR data with a high frequency antenna, the electrical properties of soil and their correlated water content can be reconstructed with a high spatiotemporal resolution. In this study, we applied the approach by using an ultra-wideband frequency-domain radar with a transmitting and receiving horn antenna operating in the frequency range 3-6 GHz for imaging, in near-field conditions, a rhizotron containing sand subject to different water content conditions. Synthetic radar data were also generated to examine the well-posedness of the full-waveform inverse problem at high frequencies. Finally, we compared the water content obtained by GPR and light transmission measurements. The results have shown that the near-field modeled and measured GPR data match very well in the frequency and time domains for both dry and wet sands. In the case of the dry sand, the estimated water content based on GPR and light transmission data was retrieved with small differences. This research shows the potential of the GPR system and near-field full-wave antenna-medium model to accurately estimate the water content of soils with a high spatial resolution. Future studies will focus on the use of GPR to monitor root water uptake dynamics of plants in field conditions. This abstract is of interest for COST Action TU1208.

Mourmeaux, Nicolas; Meunier, Félicien; Tran, Phuong Anh; Draye, Xavier; Lambot, Sébastien

2014-05-01

281

Effects of glyphosate-based herbicides on survival, development, growth and sex ratios of wood frog (Lithobates sylvaticus) tadpoles. II: Agriculturally relevant exposures to Roundup WeatherMax® and Vision® under laboratory conditions.  

PubMed

Glyphosate-based herbicides are currently the most commonly used herbicides in the world. They have been shown to affect survival, growth, development and sexual differentiation of tadpoles under chronic laboratory exposures but this has not been investigated under more environmentally realistic conditions. The purpose of this study is (1) to determine if an agriculturally relevant exposure to Roundup WeatherMax®, a relatively new and understudied formulation, influences the development of wood frog tadpoles (Lithobates sylvaticus) through effects on the mRNA levels of genes involved in the control of metamorphosis; (2) to compare results to the well-studied Vision® formulation (containing the isopropylamine salt of glyphosate [IPA] and polyethoxylated tallowamine [POEA] surfactant) and to determine which ingredient(s) in the formulations are responsible for potential effects on development; and (3) to compare results to recent field studies that used a similar experimental design. In the present laboratory study, wood frog tadpoles were exposed to an agriculturally relevant application (i.e., two pulses) of Roundup WeatherMax® and Vision® herbicides as well as the active ingredient (IPA) and the POEA surfactant of Vision®. Survival, development, growth, sex ratios and mRNA levels of genes involved in tadpole metamorphosis were measured. Results show that Roundup WeatherMax® (2.89mg acid equivalent (a.e.)/L) caused 100% mortality after the first pulse. Tadpoles treated with a lower concentration of Roundup WeatherMax® (0.21mg a.e./L) as well as Vision® (2.89mg a.e./L), IPA and POEA had an increased condition factor (based on length and weight measures in the tadpoles) relative to controls at Gosner stage (Gs) 36/38. At Gs42, tadpoles treated with IPA and POEA had a decreased condition factor. Also at Gs42, the effect on condition factor was dependent on the sex of tadpoles and significant treatment effects were only detected in males. In most cases, treatment reduced the normal mRNA increase of key genes controlling development in tadpoles between Gs37 and Gs42, such as genes encoding thyroid hormone receptor beta in brain, glucocorticoid receptor in tail and deiodinase enzyme in brain and tail. We conclude that glyphosate-based herbicides have the potential to alter mRNA profiles during metamorphosis. However, studies in natural systems have yet to replicate these negative effects, which highlight the need for more ecologically relevant studies for risk assessment. PMID:24912403

Lanctôt, C; Navarro-Martín, L; Robertson, C; Park, B; Jackman, P; Pauli, B D; Trudeau, V L

2014-09-01

282

NCBI More Information: Similarity  

NSDL National Science Digital Library

This page summarizes the basic concept and vocabulary of sequence similarity searching. It is included for those new to the field who may not appreciate the importance of this technique in biology, who lack the vocabulary to understand the BLAST guide and tutorial or who require a basic rather than a sophisticated understanding of the methods involved. Sections include introduction, premise, terms, general approach, the BLAST algorithm, quantification, gaps, significance, and databases. Users can link to BLAST, BLAST tutorial, and additional BLAST information from this page.

Information, National C.

283

Similar enzymes, different structures  

PubMed Central

Phthalate dioxygenase (PDO) is a member of a class of bacterial oxygenases that contain both Rieske [2Fe-2S] and Fe(II) mononuclear centers. Recent crystal structures of several Rieske dioxygenases showed that they exist as ?3?3 multimers with subunits arranged head-to-tail in ? and ? stacked planar consists of only ?-subunits, remains to be solved. Although similar to other Rieske dioxygenases in many aspects, PDO was shown to differ in the mechanism of catalysis. Gel filtration and analytical centrifugation experiments, supplemented with mass spectrometric analysis (both ESI-MS and ESI-GEMMA), in this work showed a hexameric arrangement of subunits in the PDO multimer. Our proposed model for the subunit arrangement in PDO postulates two ?3 planar rings one on top the other, similar to the ?3?3 arrangement in other Rieske dioxygenases. Unlike other Rieske dioxygenases, this arrangement brings two Rieske and two mononuclear centers, all on separate subunits, into proximity, allowing their cooperation for catalysis. Potential reasons necessitating this unusual structural arrangement are discussed.

Tarasev, Michael; Kaddis, Catherine S.; Yin, Sheng; Loo, Joseph A.; Burgner, John; Ballou, David P.

2007-01-01

284

Mechanisms for similarity based cooperation  

NASA Astrophysics Data System (ADS)

Cooperation based on similarity has been discussed since Richard Dawkins introduced the term “green beard” effect. In these models, individuals cooperate based on an aribtrary signal (or tag) such as the famous green beard. Here, two different models for such tag based cooperation are analysed. As neutral drift is important in both models, a finite population framework is applied. The first model, which we term “cooperative tags” considers a situation in which groups of cooperators are formed by some joint signal. Defectors adopting the signal and exploiting the group can lead to a breakdown of cooperation. In this case, conditions are derived under which the average abundance of the more cooperative strategy exceeds 50%. The second model considers a situation in which individuals start defecting towards others that are not similar to them. This situation is termed “defective tags”. It is shown that in this case, individuals using tags to cooperate exclusively with their own kind dominate over unconditional cooperators.

Traulsen, A.

2008-06-01

285

Laboratory Astrochemistry: Interstellar PAHs  

NASA Technical Reports Server (NTRS)

Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are thought to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: (1) objectives, (2) approach and techniques adopted, (3) adaptability to the nature of the problem(s), and (4) results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a closer simulation of space environments and a better support to space missions.

Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

286

Similarities to Lunar Highlands  

NASA Technical Reports Server (NTRS)

After passing Mercury the first time and making a trip around the Sun, Mariner 10 again flew by Mercury on September 21 at 1:59 PMPDT. This encounter brought the spacecraft in front of Mercury in the southern hemisphere.

Much of Mercury looks like the lunar highlands, a scene carved by billions of years of impact craters. This image (FDS 166724)was taken when Mariner 10 was near its closest approach to the planet during the second encounter, about 50,000 km. This image is found near the center of the area not imaged during the first encounter.

The Mariner 10 mission, managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, explored Venus in February 1974 on the way to three encounters with Mercury-in March and September 1974 and in March 1975. The spacecraft took more than 7,000 photos of Mercury, Venus, the Earth and the Moon.

Image Credit: NASA/JPL/Northwestern University

1974-01-01

287

Effect of ectoparasitic Pimeliaphilus plumifer mites (Acari: Pterygosomatidae) on Meccus pallidipennis (Hemiptera: Reduviidae) and several other Chagas' disease vectors under laboratory conditions.  

PubMed

Several biological parameters were evaluated to determine the capacity of Pimeliaphilus plumifer as biological control agent of Triatominae bugs. When P. plumifer and bugs of a variety of triatomine species were forced together in cages in the laboratory, the incidence of mite infestation was the following: Meccus pallidipennis > M. bassolsae > Triatoma rubida > M. longipennis > M. picturatus, and practically no mites were found on T. infestans and Rhodnius prolixus. Adults and hexapod larvae of P. plumifer were the only stages found to parasitize on M. pallidipennis. Fourth and fifth instar nymphs of this bug appeared most susceptible to mite infestation. P. plumifer mites located preferably on the coxae, ventral abdomen and pronotum of M. pallidipennis bugs. The number of blood meals, amount of ingested blood, and resistance to starvation of M. pallidipennis were similar in both the control and the mite infested groups. On the other hand, mite infection reduced molting rate in nymphs and longevity in adults, increased mortality in third-fifth instar nymphs, and fewer viable eggs were laid by females infected with P. plumifer. These effects could be related with nutritional deficiencies. Our results support the use of P. plumifer mites as control agents of host Triatominae species. PMID:17549587

Martinez-Sanchez, Abisai; Camacho, Alejandro D; Quintero-Martinez, Maria Teresa; Alejandre-Aguilar, Ricardo

2007-01-01

288

Laboratory measurements of the W band (3.2 mm) properties of phosphine (PH3) and ammonia (NH3) under simulated conditions for the outer planets  

NASA Astrophysics Data System (ADS)

A model, based on the Van Vleck-Weisskopf line shape, was developed for the centimeter-wavelength opacity of PH3, which provides an order of magnitude improvement over previous models [Hoffman et al., 2001]. New laboratory measurements indicate that the model is also accurate at 94 GHz (3.2 mm) under conditions for the outer planets. Measurements of the opacity and refractivity of PH3 in a hydrogen/helium (H2/He) atmosphere were conducted at 94 GHz (3.2 mm) at pressures of 0.5 and 2 bars and at temperatures of 293 K and 213 K. Additionally, new high-precision laboratory measurements of the opacity and refractivity of NH3 in an H2/He atmosphere were conducted at the same frequency at pressures from 0.5 to 2 bars and at temperatures of 204 K, 211 K, and 290 K. Results show that existing models, which predict NH3 opacity in an H2/He environment, understate the absorption due to the pressure broadened rotational lines. A new model is proposed for use at 94 GHz (3.2 mm) which uses a Ben-Reuven line shape [Ben-Reuven, 1966] for the inversion lines and a Kinetic line shape [Gross, 1955] for the rotational lines. Results of measurements of both PH3 and NH3 can be used to better interpret maps of Saturn's emission at this wavelength and can potentially be used to deduce spatial variations in the abundances of both gases in the atmosphere of Saturn.

Mohammed, Priscilla N.; Steffes, Paul G.

2004-07-01

289

Good Laboratory Practices for Molecular Genetic Testing for Heritable Diseases and Conditions. Morbidity and Mortality Weekly Report, Vol. 58, No. RR-6, June 12, 2009.  

National Technical Information Service (NTIS)

Under the Clinical Laboratory Improvement Amendments of 1988 (CLIA) regulations, laboratory testing is categorized as waived (from routine regulatory oversight) or nonwaived based on the complexity of the tests; tests of moderate and high complexity are n...

2009-01-01

290

Laboratory Experiments, Numerical Simulations, and Astronomical Observations of Deflected Supersonic Jets: Application to HH 110  

Microsoft Academic Search

Collimated supersonic flows in laboratory experiments behave in a similar manner to astrophysical jets provided that radiation, viscosity, and thermal conductivity are unimportant in the laboratory jets and that the experimental and astrophysical jets share similar dimensionless parameters such as the Mach number and the ratio of the density between the jet and the ambient medium. When these conditions apply,

P. Hartigan; J. M. Foster; B. H. Wilde; R. F. Coker; P. A. Rosen; J. F. Hansen; B. E. Blue; R. J. R. Williams; R. Carver; A. Frank

2009-01-01

291

Larval food quantity affects development time, survival and adult biological traits that influence the vectorial capacity of Anopheles darlingi under laboratory conditions  

PubMed Central

Background The incidence of malaria in the Amazon is seasonal and mosquito vectorial capacity parameters, including abundance and longevity, depend on quantitative and qualitative aspects of the larval diet. Anopheles darlingi is a major malaria vector in the Amazon, representing >95% of total Anopheles population present in the Porto Velho region. Despite its importance in the transmission of the Plasmodium parasite, knowledge of the larval biology and ecology is limited. Studies regarding aspects of adult population ecology are more common than studies on larval ecology. However, in order develop effective control strategies and laboratory breeding conditions for this species, more data on the factors affecting vector biology is needed. The aim of the present study is to assess the effects of larval food quantity on the vectorial capacity of An. darling under laboratory conditions. Methods Anopheles darlingi was maintained at 28°C, 80% humidity and exposed to a daily photoperiod of 12?h. Larvae were divided into three experimental groups that were fed either a low, medium, or high food supply (based on the food amounts consumed by other species of culicids). Each experiment was replicated for six times. A cohort of adults were also exposed to each type of diet and assessed for several biological characteristics (e.g. longevity, bite frequency and survivorship), which were used to estimate the vectorial capacity of each experimental group. Results The group supplied with higher food amounts observed a reduction in development time while larval survival increased. In addition to enhanced longevity, increasing larval food quantity was positively correlated with increasing frequency of bites, longer blood meal duration and wing length, resulting in greater vectorial capacity. However, females had greater longevity than males despite having smaller wings. Conclusions Overall, several larval and adult biological traits were significantly affected by larval food availability. Greater larval food supply led to enhance larval and production and larger mosquitoes with longer longevity and higher biting frequency. Thus, larval food availability can alter important biological traits that influence the vectorial capacity of An. darlingi.

2012-01-01

292

Measuring Total Flux of Organic Vapors From the Unsaturated Zone Under Natural Conditions: Design, Laboratory and Field Testing of a Flux Chamber Device  

NASA Astrophysics Data System (ADS)

A simple, easy-to-use, and inexpensive device for measuring VOC flux under natural conditions was designed and tested both in a controlled laboratory environment and in a natural field setting. The chamber consists of a stainless-steel right circular cylinder open on one end with a flexible, impermeable membrane allowing for chamber expansion and contraction. Air is pumped from inside the chamber through activated carbon traps and returned to the chamber maintaining a net zero pressure gradient from the inside to the outside of the chamber. The traps are analyzed using thermal desorption/GC-FID and the mass of contaminant is divided by the product of the sampled area and sample time to give VOC flux measured by the chamber. Design parameters for the chamber were selected using continuously stirred tank reactor (CSTR)-equation based modeling under step, sinusoidal and transport-model simulation flux inputs. Laboratory testing of the flux chamber under both diffusion and advection dominated conditions was performed in a device constructed to simulate unsaturated zone transport. Aqueous trichloroethene (TCE) solution was pumped through the bottom of a steel drum inside which 50-cm of fine sand was suspended. For diffusion-dominated transport experiments, the chamber was installed in the sand at the top of the simulator and operated in the same manner as would occur in the field. The flux measurement of the chamber was then compared to flux prediction based on measured linear concentration data from the simulator and Fick's law. Advective transport is initiated in the vadose zone simulator by flowing humidified, pressurized air into an input port in the bottom of the simulator below the suspended porous media. Soil-gas velocity is calculated by dividing the airflow input by the surface area of the simulator. Flux was measured with the chamber and compared to flux predicted using airflow and concentration data from the simulator. Results from both the diffusion-only and combined advection/diffusion tests indicate the chamber device performs well under a wide range of fluxes. Additionally, results of side-by-side testing of three chamber devices at a TCE-contaminated field site are presented.

Tillman, F. D.; Choi, J.; Smith, J. A.

2002-05-01

293

Optimization of detection conditions and single-laboratory validation of a multiresidue method for the determination of 135 pesticides and 25 organic pollutants in grapes and wine by gas chromatography time-of-flight mass spectrometry.  

PubMed

This paper describes single-laboratory validation of a multiresidue method for the determination of 135 pesticides, 12 dioxin-like polychlorinated biphenyls, 12 polyaromatic hydrocarbons, and bisphenol A in grapes and wine by GC/time-of-flight MS in a total run time of 48 min. The method is based on extraction with ethyl acetate in a sample-to-solvent ratio of 1:1, followed by selective dispersive SPE cleanup for grapes and wine. The GC/MS conditions were optimized for the chromatographic separation and to achieve highest S/N for all 160 target analytes, including the temperature-sensitive compounds, like captan and captafol, that are prone to degradation during analysis. An average recovery of 80-120% with RSD < 10% could be attained for all analytes except 17, for which the average recoveries were 70-80%. LOQ ranged within 10-50 ng/g, with < 25% expanded uncertainties, for 155 compounds in grapes and 151 in wine. In the incurred grape and wine samples, the residues of buprofezin, chlorpyriphos, metalaxyl, and myclobutanil were detected, with an RSD of < 5% (n = 6); the results were statistically similar to previously reported validated methods. PMID:21391504

Dasgupta, Soma; Banerjee, Kaushik; Dhumal, Kondiba N; Adsule, Pandurang G

2011-01-01

294

Complete larval development of the hermit crabs Clibanarius aequabilis and Clibanarius erythropus (Decapoda: Anomura: Diogenidae), under laboratory conditions, with a revision of the larval features of genus Clibanarius  

NASA Astrophysics Data System (ADS)

The complete larval development (four zoeae and one megalopa) of Clibanarius aequabilis and C. erythropus, reared under laboratory conditions, is described and illustrated. The larval stages of the two northeastern Atlantic Clibanarius species cannot be easily differentiated. Their morphological characters are compared with those of other known Clibanarius larvae. The genus Clibanarius is very homogeneous with respect to larval characters. All Clibanarius zoeae display a broad and blunt rostrum, smooth abdominal segments and an antennal scale without a terminal spine. Beyond the second zoeal stage, the fourth telson process is present as a fused spine, and the uropods are biramous. In the fourth larval stage all species display a mandibular palp. The Clibanarius megalopa presents weakly developed or no ocular scales, symmetrical chelipeds, apically curved corneous dactylus in the second and third pereiopods, and 5-11 setae on the posterior margin of the telson. Apart from the number of zoeal stages, Clibanarius species may be separated, beyond the second zoeal stage, by the telson formula and the morphology of the fourth telson process.

Bartilotti, Cátia; Calado, Ricardo; Dos Santos, Antonina

2008-06-01

295

Dispersal and Survival of Flavobacterium psychrophilum Phages In Vivo in Rainbow Trout and In Vitro under Laboratory Conditions: Implications for Their Use in Phage Therapy  

PubMed Central

Attention has been drawn to phage therapy as an alternative approach for controlling pathogenic bacteria such as Flavobacterium psychrophilum in salmonid aquaculture, which can give rise to high mortalities, especially in rainbow trout fry. Recently, phages have been isolated with a broad host range and a strong lytic potential against pathogenic F. psychrophilum under experimental conditions. However, little is known about the fate of phages at environmental conditions. Here, we quantified the dispersal and fate of F. psychrophilum phages and hosts in rainbow trout fry after intraperitoneal injection. Both phages and bacteria were isolated from the fish organs for up to 10 days after injection, and coinjection with both bacteria and phages resulted in a longer persistence of the phage in the fish organs, than when the fish had been injected with the phages only. The occurrence of both phage and bacterium was most prevalent in the kidney and spleen, with only minor occurrence in the brain. The experiment showed that injected phages were rapidly spread in the internal organs of the fish, also in the absence of bacteria. Parallel examination of the regulation of bacteriophage infectivity in controlled laboratory experiments at various environmental conditions showed that pH had only minor effects on long-term (3 months) phage infectivity within a pH range of 4.5 to 7.5, whereas phage infectivity was immediately lost at pH 3. In the absence of host cells, phage infectivity decreased by a factor of 10,000 over 55 days in untreated pond water, while the sterilization and removal of particles caused a 100-fold increase in phage survival relative to the control. In addition, F. psychrophilum-specific phages maintained their infectivity for ?2 months in glycerol at ?80°C, whereas infectivity decreased by a factor 10 when kept in a buffer at 20°C. Only a very small degradation in infectivity was seen when bacteriophages were added and dried on fish feed pellets. Together, these results indicate that application of bacteriophages represents a promising approach for the control of F. psychrophilum infections in trout and suggest fish feed as a potential delivery method.

Bertelsen, Sif K.; Dalsgaard, Inger; Middelboe, Mathias

2013-01-01

296

Reconsolidation of Crushed Salt to 250°C Under Hydrostatic and Shear Stress Conditions Scott Broome, Frank Hansen, and SJ Bauer Sandia National Laboratories, Geomechanics Department  

NASA Astrophysics Data System (ADS)

Design, analysis and performance assessment of potential salt repositories for heat-generating nuclear waste require knowledge of thermal, mechanical, and fluid transport properties of reconsolidating granular salt. Mechanical properties, Bulk (K) and Elastic (E) Moduli and Poisson's ratio (?) are functions of porosity which decreases as the surrounding salt creeps inward and compresses granular salt within the rooms, drifts or shafts. To inform salt repository evaluations, we have undertaken an experimental program to determine K, E, and ? of reconsolidated granular salt as a function of porosity and temperature and to establish the deformational processes by which the salt reconsolidates. The experiments will be used to populate the database used in the reconsolidation model developed by Callahan (1999) which accounts for the effects of moisture through pressure solution and dislocation creep, with both terms dependent on effective stress to account for the effects of porosity. Mine-run salt from the Waste Isolation Pilot Program (WIPP) was first dried at 105 °C for a few days. Undeformed right-circular cylindrical sample assemblies of unconsolidated granular salt with an initial porosity of ~ 40%, nominally 10 cm in diameter and 17.5 cm in length, are jacketed in lead. Samples are placed in a pressure vessel and kept at test temperatures of 100, 175 or 250 °C; samples are vented to the atmosphere during the entire test procedure. At these test conditions the consolidating salt is always creeping, the creep rate increases with increasing temperature and stress and decreases as porosity decreases. In hydrostatic tests, confining pressure is increased to 20 MPa with periodic unload/reload loops to determine K. Volume strain increases with increasing temperature. In shear tests at 2.5 and 5 MPa confining pressure, after confining pressure is applied, the crushed salt is subjected to a differential stress, with periodic unload/reload loops to determine E and ?. At predetermined differential stress levels the stress is held constant and the salt consolidates. Displacement gages mounted on the samples show little lateral deformation until the samples reach a porosity of ~10%. Interestingly, vapor is vented in tests at 250°C and condenses at the vent port. Release of water is not observed in the lower two test temperatures. It is hypothesized that the water originates from fluid inclusions, which were made accessible by intragranular deformational processes including decrepitation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Broome, S. T.

2012-12-01

297

Assessment of environmental stress by the micronucleus and comet assays on Limnoperna fortunei exposed to Guaíba hydrographic region samples (Brazil) under laboratory conditions.  

PubMed

The Guaíba Basin is a source of drinking water for Porto Alegre (RS, Brazil). The water from this basin receives industrial, urban, and rural waste from many sources. The mussel species Limnoperna fortunei was chosen based on population data, distribution, and sensitivity. Previous tests with comet assay and micronuclei frequency in this freshwater mussel have shown to be successful in biomonitoring studies. The aim of this study was to evaluate the genotoxic contamination of the Guaíba Lake Hydrographic Region, through the determination of damage by the micronuclei and comet assays in L. fortunei (golden mussel). Nine sampling sites were evaluated in three different seasons: five sites in the mouths of the main rivers that flow into Guaíba lake; one site at the mouth of a stream; one major site of sewage discharge; two sites at Guaíba lake, near a sewage discharge; and the control site in a preservation area. DNA damage was detected by the single cell gel assay, as well as the frequency of micronuclei in hemocytes of mussels exposed under laboratory conditions for 7 days to water and sediment samples. Significant results were found in different seasons in almost all sampling sites (P<0.05, ANOVA Dunnet's test). Most of the positive results were found in samples affected mainly by urban effluents. It was possible to observe that there was a weak relation between mutagenic and genotoxic responses and mussels inorganic elements contents. Seasonal variation was observed at different sampling sites, but always indicating a huge contamination near urban sewage discharge. These results are consistent with previous studies, allowing us to infer that urban contamination is the biggest problem in this region. It is also possible to infer that L. fortunei is a good sentinel organism for the Guaíba Basin. PMID:17267262

Villela, Izabel Vianna; de Oliveira, Iuri Marques; Silveira, Juliano Coelho; Dias, Johnny Ferraz; Henriques, João Antonio Pêgas; da Silva, Juliana

2007-04-01

298

Effect of Azadirachta indica (neem), sodium thiosulphate and calcium chloride on changes in nitrogen transformations and inhibition of nitrification in soil incubated under laboratory conditions.  

PubMed

A laboratory experiment was conducted to examine the effects of nitrification inhibitors (NIs) neem seed-cake (Azadirachta indica) (NSC), sodium thiosulphate (Na?S?O?) and calcium chloride (CaCl?) on changes in NH?(+)?N, inhibition of nitrification and recovery of applied nitrogen (N) in soil. Surface soil samples of 0-15 cm were collected from an arable field, amended with urea N (UN) at the rate 200 mg N kg?¹, UN+NSC, UN+Na?S?O? and UN+CaCl? and incubated at 22°C periodically over 50 d. Soil without any amendment was used as check (control). Results indicated that more than 58% of N applied as NH?? disappeared over a period of 50 d from the soil mineral-N pool. Some of this N (21%) was accumulated as NO??-N while the remaining N was unaccounted for. Addition of nitrification inhibitors NSC, Na?S?O?, and CaCl? resulted in a decrease in the extent of NH?(+) disappearance by 35%, 44% and 30%, respectively. In the treatment receiving UN alone, 56 mg NO??-N kg?¹ was accumulated over 50 d (maximum 93 mg kg?¹) indicated an active nitrification. Application of nitrification inhibitors NSC, Na?S?O?, and CaCl? with UN inhibited nitrification by 54%, 64%, and 59%, respectively. Apparent N recovery (ANR) in the treatment receiving UN alone was 63% that substantially increased to 83%, 89% and 76% in the treatments receiving UN+NSC, UN+Na?S?O?, and UN+CaCl?, respectively indicating 32%, 41% and 20% increase in N recovery. Among three NIs tested, Na?S?O? proved superior in inhibiting nitrification and increasing ANR. The study demonstrated that application of NSC, Na?S?O?, and CaCl? which are cheap and easily available NIs inhibited nitrification and improved N recovery efficiency of applied N in an arable soil very effectively. It is suggested that these inhibitors should be tested under field conditions for increasing NUE and improving crop productivity. PMID:21146192

Abbasi, M Kaleem; Hina, Munazza; Tahir, Majid Mahmood

2011-03-01

299

Commentaries on quantum similarity (1): Density gradient quantum similarity.  

PubMed

Computation of density gradient quantum similarity integrals is analyzed, while comparing such integrals with overlap density quantum similarity measures. Gradient quantum similarity corresponds to another kind of numerical similarity assessment between a pair of molecular frames, which contrarily to the usual up to date quantum similarity definitions are not measures, that is: strictly positive definite integrals. As the density gradient quantum similarity integrals are defined as scalar products of three real functions, they appear to possess a richer structure than the corresponding positive definite density overlap quantum similarity measures, while preserving the overall similarity trends, when the molecular frames are relatively moved in three-dimensional space. Similarity indices are also studied when simple cases are analyzed in order to perform more comparisons with density overlap quantum similarity. Multiple gradient quantum similarity integrals are also defined. General GTO formulae are given. Numerical results within the atomic shell approximation (ASA) framework are presented as simple examples showing the new performances of the gradient density quantum similarity. Fortran 90 programs illustrating the proposed theoretical development can be downloaded from appropriate websites. PMID:20336768

Carbó-Dorca, Ramon; Mercado, Luz Dary

2010-08-01

300

Exploration Laboratory Analysis FY13  

NASA Technical Reports Server (NTRS)

The Exploration Laboratory Analysis (ELA) project supports the Exploration Medical Capability (ExMC) risk, which is stated as the Risk of Inability to Adequately Treat an Ill or Injured Crew Member, and ExMC Gap 4.05: Lack of minimally invasive in-flight laboratory capabilities with limited consumables required for diagnosing identified Exploration Medical Conditions. To mitigate this risk, the availability of inflight laboratory analysis instrumentation has been identified as an essential capability in future exploration missions. Mission architecture poses constraints on equipment and procedures that will be available to treat evidence-based medical conditions according to the Space Medicine Exploration Medical Conditions List (SMEMCL), and to perform human research studies on the International Space Station (ISS) that are supported by the Human Health and Countermeasures (HHC) element. Since there are significant similarities in the research and medical operational requirements, ELA hardware development has emerged as a joint effort between ExMC and HHC. In 2012, four significant accomplishments were achieved towards the development of exploration laboratory analysis for medical diagnostics. These achievements included (i) the development of high priority analytes for research and medical operations, (ii) the development of Level 1 functional requirements and concept of operations documentation, (iii) the selection and head-to-head competition of in-flight laboratory analysis instrumentation, and (iv) the phase one completion of the Small Business Innovation Research (SBIR) projects under the topic Smart Phone Driven Blood-Based Diagnostics. To utilize resources efficiently, the associated documentation and advanced technologies were integrated into a single ELA plan that encompasses ExMC and HHC development efforts. The requirements and high priority analytes was used in the selection of the four in-flight laboratory analysis performers. Based upon the competition results, a down select process will be performed in the upcoming year. Looking ahead, this unified effort has positioned each element for an in-flight lab analysis demonstration of select diagnostics measurements in the 2015 timeframe.

Krihak, Michael; Perusek, Gail P.; Fung, Paul P.; Shaw, Tianna, L.

2013-01-01

301

Similarity increases altruistic punishment in humans  

PubMed Central

Humans are attracted to similar others. As a consequence, social networks are homogeneous in sociodemographic, intrapersonal, and other characteristics—a principle called homophily. Despite abundant evidence showing the importance of interpersonal similarity and homophily for human relationships, their behavioral correlates and cognitive foundations are poorly understood. Here, we show that perceived similarity substantially increases altruistic punishment, a key mechanism underlying human cooperation. We induced (dis)similarity perception by manipulating basic cognitive mechanisms in an economic cooperation game that included a punishment phase. We found that similarity-focused participants were more willing to punish others’ uncooperative behavior. This influence of similarity is not explained by group identity, which has the opposite effect on altruistic punishment. Our findings demonstrate that pure similarity promotes reciprocity in ways known to encourage cooperation. At the same time, the increased willingness to punish norm violations among similarity-focused participants provides a rationale for why similar people are more likely to build stable social relationships. Finally, our findings show that altruistic punishment is differentially involved in encouraging cooperation under pure similarity vs. in-group conditions.

Mussweiler, Thomas; Ockenfels, Axel

2013-01-01

302

Multivariate Time Series Similarity Searching  

PubMed Central

Multivariate time series (MTS) datasets are very common in various financial, multimedia, and hydrological fields. In this paper, a dimension-combination method is proposed to search similar sequences for MTS. Firstly, the similarity of single-dimension series is calculated; then the overall similarity of the MTS is obtained by synthesizing each of the single-dimension similarity based on weighted BORDA voting method. The dimension-combination method could use the existing similarity searching method. Several experiments, which used the classification accuracy as a measure, were performed on six datasets from the UCI KDD Archive to validate the method. The results show the advantage of the approach compared to the traditional similarity measures, such as Euclidean distance (ED), cynamic time warping (DTW), point distribution (PD), PCA similarity factor (SPCA), and extended Frobenius norm (Eros), for MTS datasets in some ways. Our experiments also demonstrate that no measure can fit all datasets, and the proposed measure is a choice for similarity searches.

Wang, Jimin; Zhu, Yuelong; Li, Shijin; Wan, Dingsheng; Zhang, Pengcheng

2014-01-01

303

Transformation and Alignment in Similarity  

ERIC Educational Resources Information Center

This paper contrasts two structural accounts of psychological similarity: structural alignment (SA) and Representational Distortion (RD). SA proposes that similarity is determined by how readily the structures of two objects can be brought into alignment; RD measures similarity by the complexity of the transformation that "distorts" one…

Hodgetts, Carl J.; Hahn, Ulrike; Chater, Nick

2009-01-01

304

Anatoxin-a concentration in Anabaena and Aphanizomenon under different environmental conditions and comparison of growth by toxic and non-toxic Anabaena -strains — a laboratory study  

Microsoft Academic Search

Anatoxin-a-concentration in cells ofAnabaena- andAphanizomenon-strains and in their growth media were studied in the laboratory in batch cultures at different temperatures, light fluxes, orthophosphate and nitrate concentrations and with different nitrogen sources for growth. Toxin concentrations were detected by HPLC. Also, the growth of the toxicAnabaena-strains was compared to that of a non-toxic one. The non-toxicAnabaena was never found to

Jarkko Rapala; Kaarina Sivonen; Raija Luukkainen; Seppo I. Niemelä

1993-01-01

305

A framework for profile similarity: integrating similarity, normativeness, and distinctiveness.  

PubMed

Many questions in personality psychology lend themselves to the analysis of profile similarity. A profile approach to issues such as personality judgment, personality similarity, behavioral consistency, developmental stability, and person-environment fit is intuitively appealing. However, it entails conceptual and statistical challenges arising from the overlap among profile similarity and normativeness, which presents potential confounds and potential opportunities. This article describes the normativeness problem, articulating the need to evaluate profile similarity alongside normativeness and distinctiveness. It presents conceptual and psychometric foundations of a framework differentiating these elements for pairs of profiles. It derives two models from this framework, and it discusses the application of their components to a variety of research domains. Finally, it presents recommendations and implications regarding the use of these components and profile similarity more generally. This approach can reveal and manage potential confounds, and it can provide theoretical insights that might otherwise be overlooked. PMID:18705644

Furr, R Michael

2008-10-01

306

a Comparison of Semantic Similarity Models in Evaluating Concept Similarity  

NASA Astrophysics Data System (ADS)

The semantic similarities are important in concept definition, recognition, categorization, interpretation, and integration. Many semantic similarity models have been established to evaluate semantic similarities of objects or/and concepts. To find out the suitability and performance of different models in evaluating concept similarities, we make a comparison of four main types of models in this paper: the geometric model, the feature model, the network model, and the transformational model. Fundamental principles and main characteristics of these models are introduced and compared firstly. Land use and land cover concepts of NLCD92 are employed as examples in the case study. The results demonstrate that correlations between these models are very high for a possible reason that all these models are designed to simulate the similarity judgement of human mind.

Xu, Q. X.; Shi, W. Z.

2012-08-01

307

Oral and Cutaneous Melanoma: Similarities and Differences  

PubMed Central

Melanomas are malignant lesions stemming from the disorganized proliferation of melanocytes. This condition is more common on skin, but may also be detected in mucosa, such as in the oral cavity. The aim of the present study was to report similarities and differences between oral and cutaneous melanoma. Keywords Melanoma; Skin; Mouth; Diagnosis

Moreira, Rafaela Nogueira; Santos, Cassio Roberto Rocha; Lima, Nadia Lages; Verli, Flaviana Dornela; Marinho, Sandra Aparecida

2010-01-01

308

Applicability of Similarity Principles to Structural Models  

NASA Technical Reports Server (NTRS)

A systematic account is given in part I of the use of dimensional analysis in constructing similarity conditions for models and structures. The analysis covers large deflections, buckling, plastic behavior, and materials with nonlinear stress-strain characteristics, as well as the simpler structural problems. (author)

Goodier, J N; Thomson, W T

1944-01-01

309

Applicability of similarity principles to structural models  

NASA Technical Reports Server (NTRS)

A systematic account is given in part I of the use of dimensional analysis in constructing similarity conditions for models and structures. The analysis covers large deflections, buckling, plastic behavior, and materials with nonlinear stress-strain characteristics, as well as the simpler structural problems. (author)

Goodier, J N; Thomson, W T

1944-01-01

310

High voltage laboratory tests and lightning phenomena  

NASA Astrophysics Data System (ADS)

Attention is given to the similarities and differences which exist between the laboratory long spark and an actual lightning stroke. The feasibility of using simulation to evaluate the consequences of natural lightning on aircraft and grounded structures is assessed. Laboratory test facilities and measuring techniques are reviewed, the main features of the long spark are presented, and the influence rendered by experimental conditions is discussed. The final stage of the discharge is described as it relates to the striking of grounded structures; discharge characteristics upon interaction with a free potential electrode inside the gap are given. It is concluded that the study of RF signals radiated by a laboratory spark could lead to a better understanding of those emitted by natural lightning. It is noted that the striking of grounded structures is satisfactorily reproduced by laboratory tests.

Hutzler, B.; Riquel, G.; Riu, J.-P.

311

Measuring Similarity for Security Vulnerabilities  

Microsoft Academic Search

As the number of software vulnerabilities increases year by year, software vulnerability becomes a focusing point in information security. This paper proposes a vulnerability similarity measurement to compare different vulnerabilities according to a set of criteria. Our approach is based on the structural hierarchy of vulnerabilities, and the similarity is defined using established mathematical models. The National Vulnerability Database and

Ju An Wang; Linfeng Zhou; Minzhe Guo; Hao Wang; Jairo Camargo

2010-01-01

312

Computing Semantic Similarity Using Ontologies  

Microsoft Academic Search

Determining semantic similarity of two sets of words that describe two entities is an important problem in web mining (search and recommendation systems), targeted advertisement and domains that need semantic content matching. Traditional Information Retrieval ap- proaches, even when extended to include semantics by performing the similarity comparison on concepts instead of words\\/terms, may not al- ways determine the right

Rajesh Thiagarajan; Geetha Manjunath; Markus Stumptner

313

Laboratory Astrochemistry: Interstellar PAH Analogs  

NASA Technical Reports Server (NTRS)

Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a closer simulation of space environments and a better support to space missions.

Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

314

Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1992 through 1995  

SciTech Connect

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The US Geological Survey, in cooperation with the US Department of Energy, maintains a monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1992--95.

Bartholomay, R.C.; Tucker, B.J.; Ackerman, D.J.; Liszewski, M.J.

1997-04-01

315

The Attraction Hypothesis: Do Similar Attitudes Affect Anything?  

Microsoft Academic Search

Rosenbaum's (1986) interesting attempt to demonstrate the irrelevance of similar attitudes is unsuccessful for several reasons. In three of the four attraction experiments he conducted, similar-attitude conditions were not compared with neutral control conditions as required, but instead they were compared with positive trait adjective conditions. In addition, it is not possible to create a no-attitude \\

Donn Byrne; Gerald L. Clore; George Smeaton

1986-01-01

316

Criteria for dynamic similarity in bouncing gaits.  

PubMed

Animals of different sizes tend to move in a dynamically similar manner when travelling at speeds corresponding to equal values of a dimensionless parameter (DP) called the Froude number. Consequently, the Froude number has been widely used for defining equivalent speeds and predicting speeds of locomotion by extinct species and on other planets. However, experiments using simulated reduced gravity have demonstrated that equality of the Froude number does not guarantee dynamic similarity. This has cast doubt upon the usefulness of the Froude number in locomotion research. Here we use dimensional analysis of the planar spring-mass model, combined with Buckingham's Pi-Theorem, to demonstrate that four DPs must be equal for dynamic similarity in bouncing gaits such as trotting, hopping and bipedal running. This can be reduced to three DPs by applying the constraint of maintaining a constant average speed of locomotion. Sensitivity analysis indicates that all of these DPs are important for predicting dynamic similarity. We show that the reason humans do not run in a dynamically similar manner at equal Froude number in different levels of simulated reduced gravity is that dimensionless leg stiffness decreases as gravity increases. The reason that the Froude number can predict dynamic similarity in Earth gravity is that dimensionless leg stiffness and dimensionless vertical landing speed are both independent of size. In conclusion, although equal Froude number is not sufficient for dynamic similarity, it is a necessary condition. Therefore, to detect fundamental differences in locomotion, animals of different sizes should be compared at equal Froude number, so that they can be as close to dynamic similarity as possible. More generally, the concept of dynamic similarity provides a powerful framework within which similarities and differences in locomotion can be interpreted. PMID:17983630

Bullimore, Sharon R; Donelan, J Maxwell

2008-01-21

317

The Baryonic Self Similarity of Dark Matter  

NASA Astrophysics Data System (ADS)

The cosmological simulations indicates that dark matter halos have specific self-similar properties. However, the halo similarity is affected by the baryonic feedback. By using momentum-driven winds as a model to represent the baryon feedback, an equilibrium condition is derived which directly implies the emergence of a new type of similarity. The new self-similar solution has constant acceleration at a reference radius for both dark matter and baryons. This model receives strong support from the observations of galaxies. The new self-similar properties imply that the total acceleration at larger distances is scale-free, the transition between the dark matter and baryons dominated regime occurs at a constant acceleration, and the maximum amplitude of the velocity curve at larger distances is proportional to M 1/4. These results demonstrate that this self-similar model is consistent with the basics of modified Newtonian dynamics (MOND) phenomenology. In agreement with the observations, the coincidence between the self-similar model and MOND breaks at the scale of clusters of galaxies. Some numerical experiments show that the behavior of the density near the origin is closely approximated by a Einasto profile.

Alard, C.

2014-06-01

318

Effect of inland saline water ionic profiles on growth, chemical composition and agar characteristics of Gracilaria cliftonii (Withell, Miller and Kraft 1994) under laboratory conditions  

Microsoft Academic Search

Increase in salinity of inland water sources is adversely affecting aquatic and terrestrial ecosystems around the world including\\u000a Australia. Inland saline water (ISW) with similar ionic profile to ocean water has potential for culturing marine species.\\u000a Gracilaria species are commercially important as they are a source of agar. One of the native species Gracilaria\\u000a cliftonii has been reported for high

Vivek Kumar; Ravi Fotedar; Ken Dods

2010-01-01

319

Health and Survival of Red Abalone Haliotis rufescens from San Miguel Island, California, USA, in a Laboratory Simulation of La Niña and El Niño Conditions  

Microsoft Academic Search

The variability in Southern California's marine climate is dominated by the El Niño–Southern Oscillation, with cycling between El Niño events (characterized by warm water, low productivity, and frequent storms) and La Niña events (which exhibit the opposite conditions). Relative to the mainland and other Channel Islands, San Miguel Island (SMI) consistently maintains cooler water temperatures and supports significant populations of

James D. Moore; Blythe C. Marshman; Calvin S. Y. Chun

2011-01-01

320

Transgenic rice plants expressing a fused protein of Cry1Ab/Vip3H has resistance to rice stem borers under laboratory and field conditions.  

PubMed

Six transgenic rice, Oryza sativa L., lines (G6H1, G6H2, G6H3, G6H4, G6H5, and G6H6) expressing a fused Cry1Ab/Vip3H protein, were evaluated for resistance against the Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Crambidae), and the stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) in the laboratory and field. The bioassay results indicated that the mortality of Asiatic rice borer and S. inferens neonate larvae on six transgenic lines from seedling to filling stage was up to 100% at 168 h after infestation. The cumulative feeding area by Asiatic rice borer neonate larvae on all transgenic lines was significantly reduced compared with the untransformed parental 'Xiushui 110' rice. A 2-yr field evaluation showed that damage during the vegetative stage (deadheart) or during the reproductive stage (whitehead) caused by Asiatic rice borer and S. inferens for transgenic lines was much lower than the control. For three lines (G6H1, G6H2, and G6H6), no damage was found during the entire growing period. Estimation of fused Cry1Ab/Vip3H protein concentrations using PathoScreen kit for Bt-Cry1Ab/1Ac protein indicated that the expression levels of Cry1Ab protein both in main stems (within the average range of 0.006-0.073% of total soluble protein) and their flag leaves (within the average range of 0.001-0.038% of total soluble protein) were significantly different among six transgenic lines at different developmental stages. Both laboratory and field researches suggested that the transgenic rice lines have considerable potential for protecting rice from attack by both stem borers. PMID:20857760

Chen, Yang; Tian, Jun-Ce; Shen, Zhi-Chen; Peng, Yu-Fa; Hu, Cui; Guo, Yu-Yuan; Ye, Gong-Yin

2010-08-01

321

Thermal Performance of Biological Substance Systems in Vitro Under Static and Dynamic Conditions at the Cryogenic Test Laboratory, NASA Kennedy Space Center, USA  

NASA Technical Reports Server (NTRS)

A unique research program, including a comprehensive study of thermal performance at cryogenic vacuum insulation systems, was performed at the NASA Kennedy Space Center. The main goal was to develop a new soft vacuum system (from 1 torr to 10 torr) that provides an intermediate level of performance (k-value below 4.8 mW/m-K). Liquid nitrogen boil-off methods were used to test conventional materials, novel materials, and certain combinations. The test articles included combinations of aluminum foil, fiberglass paper, polyester fabric, silica aerogel composite blanket, fumed silica, silica aerogel powder, and syntactic foam. A new LCI system was developed at the Cryogenics Test Laboratory. This system performs exceptionally well at soft vacuum levels and nearly as good as an MLI at high vacuum levels. Apparent thermal conductivities for the LCI range from 2 mW/m-K at soft vacuum to 0.1 mW/m-K at high vacuum. Several cryostats were designed, constructed, and calibrated by the Cryogenics Test Laboratory at KSC NASA as part of this research program. The cryostat test apparatus is a liquid nitrogen boil-off calorimeter system for direct measurement of the apparent thermal conductivity at a fixed vacuum level between 5 x 10(exp -5) and 760 torr. The apparatus is also used for transient measurements of temperature profiles. The development of efficient, robust cryogenic insulation systems has been a targeted area of research for a number of years. Improved methods of characterization, testing, and evaluation of complex biological substance systems for cryosurgery and cryobiology are the focus of this paper.

Augustynowicz, S. D.; Fesmire, James E.; Steinrock, T. (Technical Monitor)

2001-01-01

322

Enhanced repellency of binary mixtures of Zanthoxylum armatum seed oil, vanillin, and their aerosols to mosquitoes under laboratory and field conditions.  

PubMed

The repellency of Zanthoxylum armatum seed oil (ZA-SO), alone or in combination with vanillin (VA), its six major constituents, and another four major previously known Zanthoxylum piperitum fruit oil constituents, as well as aerosol products containing 5 or 10% ZA-SO and 5% VA, was evaluated against female Aedes aegypti in laboratory and field studies. Results were then compared with those of N,N-diethyl-3-methylbenzamide (DEET) as a standard. Hand in cage laboratory tests showed that 0.2, 0.1, and 0.05 mg/cm2 ZA-SO resulted in > 92% protection through 30-min postexposure and was not significantly different than 0.05 mg/cm2 DEET. Skin treated with linalool and limonene (from Z. armatum) provided > 80% repellency to female Ae. aegypti at 10-min exposure, whereas cuminaldehyde, citronellal, geranyl acetate, and cuminyl alcohol (from Zanthoxylum piperitum) provided > 90% protection during this same time period. Only cuminaldehyde and citronellal provided complete protection comparable to DEET at 10-min postexposure. After that time, repellency of all plant constituents to mosquitoes was considerably decreased (< approximately 65%). An increase in repellency and duration of effectiveness was produced by a binary 1:4 mixture of ZA-SO and VA (0.05:0.2 mg/cm2) that was significantly more effective than 0.05 mg/cm2 DEET through 90 min. In field tests, an aerosol formulation containing 5 or 10% ZA-SO plus 5% VA gave 100% repellency at 60-min postexposure. Although these formulations were equal to the level of protection afforded by 10% DEET, repellency to the binary ZA-SO aerosol formulations at 90 min was significantly less effective than DEET. However, mixtures formulated from ZA-SO and VA merit further study as potential repellents for protection of humans and domestic animals from biting and nuisance caused by mosquitoes. PMID:21337949

Kwon, Hyung Wook; Kim, Soon-Il; Chang, Kyu-Sik; Clark, J Marshall; Ahn, Young-Joon

2011-01-01

323

Similarity judgments serving eyewitness identification  

NASA Astrophysics Data System (ADS)

Current police tools of identification are flawed. The lineup suffers from being too small and no adequate solution to a criterion of similar foils. The mugshot search suffers from too many photos and inadequate procedures for choosing an appropriate subset. The composite, from inappropriate methods of selecting facial features. Our new mugshot search provides solutions to some of the problems. Witnesses choose photos similar to the offender, and the computer, using a similarity network, helps witnesses reach the offender faster. Replacing mugshots with foils, we can use the same technique as a lineup, that is significantly enlarged and leaves the choice of similar foils to the witnesses. When the mugshot search fails, a composite can be composed as a superimposition of the photos most similar to the offender. Several algorithms were tested for implementing the similarity network. They involve both the establishment of a meaningful distance criterion within 'face space' and the usage of efficient search strategies. Here, we discuss their benefits and drawbacks. A system comprising the full local album of the Haifa district (more than 10,000 photos) is presently being subjected to a field test by the Isreali police. We briefly describe the system and its user interface.

Levi, Avraham; Jungmann, Noam; Aperman, Arie

1995-09-01

324

Self-similarity and the Froissart bound  

NASA Astrophysics Data System (ADS)

The Froissart bound implies that the total cross section (or, equivalently, the structure function) cannot rise faster than the logarithmic growth of ln2(1/x). In this work, we show that such a slow growth is not compatible with the notion of self-similarity. As a result, it calls for the modification of the defining transverse-momentum-dependent parton density function (TMD PDF) of a self-similarity based proton structure function F2(x ,Q2) at small x. Using plausible assumptions, we obtain the Froissart saturation condition on this TMD PDF.

Jahan, Akbari; Choudhury, D. K.

2014-01-01

325

Laboratory Measurments of the 3.7-20 cm Wavelength Opacity of Sulfur Dioxide and Carbon Dioxide under Simulated Conditions for the Deep Atmosphere of Venus  

NASA Astrophysics Data System (ADS)

In the past two decades, multiple observations of Venus have been made at X band (3.6 cm) using the Jansky Very Large Array (VLA) and maps have been created of the 3.6 cm emission from Venus. Since the emission morphology is related both to surface features and to deep atmospheric absorption from CO2 and SO2 (see, e.g., Butler et al., Icarus 154, 2001), knowledge of the microwave absorption properties of sulfur dioxide in a carbon dioxide atmosphere under conditions for the deep atmosphere of Venus is required for proper interpretation. Except for a single measurement campaign conducted at a single wavelength (3.2 cm) over 40 years ago (Ho et al., JGR 71, 1966), no measurements of the centimeter-wavelength properties of any Venus atmospheric constituent have been conducted under conditions characteristic of the deep atmosphere (pressures from 10-92 Bars and temperatures from 400-700 K). New measurements of the microwave properties of SO2 and CO2 at wavelengths from 3.7-20 cm are now being conducted under simulated conditions for the deep atmosphere of Venus, using a new high-pressure system. Initial results from this measurement campaign conducted at 430 K and at pressures up to 92 Bars will be presented. This work is supported by the NASA Planetary Atmospheres Program under Grant NNX11AD66G.

Steffes, Paul G.; Barisich, C.

2012-10-01

326

Drug-induced acne and rose pearl: similarities*  

PubMed Central

Drug-induced acne is a common skin condition whose classic symptoms can be similar to a rose pearl, as in the case of a male patient presenting with this condition after excessive use of a cream containing corticosteroids.

Pontello Junior, Rubens; Kondo, Rogerio Nabor

2013-01-01

327

Similarity, invariance, and musical variation.  

PubMed

Perceptual similarity underlies a number of important psychological properties of musical materials, including perceptual invariance under transformation, categorization, recognition, and the sense of familiarity. Mental processes involved in the perception of musical similarity may be an integral part of the functional logic of music composition and thus underly important aspects of musical experience. How much and in what ways can musical materials be varied and still be considered as perceptually related or as belonging to the same category? The notions of musical material, musical variation, perceptual similarity and invariance, and form-bearing dimensions are considered in this light. Recent work on similarity perception has demonstrated that the transformation space for a given musical material is limited by several factors ranging from degree of match of the values of auditory attributes of the events composing the sequences to their relations of various levels of abstraction and to the degree that the transformation respects the grammar of the musical system within which the material was composed. These notions and results are considered in the light of future directions of research, particularly concerning the role of similarity and invariance in the understanding of musical form during listening. PMID:11458867

McAdams, S; Matzkin, D

2001-06-01

328

Assay conditions in laboratory experiments: is the use of constant rather than fluctuating temperatures justified when investigating temperature-induced plasticity?  

PubMed

Temperature is an important selective agent in nature. Consequently, temperature-induced plasticity which may help buffering detrimental effects of temperature variation has received considerable attention over recent decades. Laboratory studies have almost exclusively used constant temperatures, while in nature, temperature typically shows pronounced daily fluctuations. Using a factorial design with constant versus fluctuating temperatures and a higher versus a lower mean temperature, we here investigate in the butterfly Lycaena tityrus whether the use of constant temperatures is justified. Fluctuating compared to constant temperatures caused shorter development times, increased heat but decreased cold stress resistance, decreased heat-shock protein expression, and increased immunocompetence. Thus, overall, fluctuating temperatures were more beneficial to the butterflies compared to constant ones. However, despite substantial variation across temperature regimes, the ranking of trait values among treatments remained largely unaffected (e.g. lower constant as well as fluctuating temperatures caused increased pupal mass). Thus, we tentatively conclude that there is no general reason for concern about using constant temperatures in studies investigating phenotypic plasticity, which seem to comprise a fair proxy. However, substantial differences in mean values as well as interactive effects suggest that one needs to be cautious. We further demonstrate negative effects of high temperatures on butterfly immune function, which seem to result from a trade-off between the latter and the heat shock response. PMID:21286923

Fischer, Klaus; Kölzow, Nadine; Höltje, Henriette; Karl, Isabell

2011-05-01

329

Hydrologic Conditions and Distribution of Selected Constituents in Water, Snake River Plain Aquifer, Idaho National Engineering and Environmental Laboratory, Idaho, 1996 through 1998  

SciTech Connect

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering and Environmental Laboratory (INEEL) has affected water quality in the Snake River Plain aquifer. The US Geological Survey, in cooperation with the US Department of Energy, maintains a monitoring network at the INEEL to determine hydrologic trends and to delineate the movement to radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1996-98. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INEEL decreased or remained constant during 1996-98. Decreased concentrations are attributed to reduced rates of radioactive-waste disposal, sorption process, radioactive decay, and changes in waste-disposal practices. Detectable concentrations of chemical constituents in water from the Snake River Plain aquifer at the INEEL were variable during 1996-98.

R. C. Bartholomay; B. J. Tucker; L. C. Davis; M. R. Greene

2000-09-01

330

Lethal effect of a bait for Rhodnius prolixus (Hemiptera: Reduviidae), the vector of Chagas' disease, containing hexachlorocyclohexane (HCH), under laboratory conditions.  

PubMed

The lethal effect of a bait containing an aqueous hexachlorocyclohexane (HCH) suspension at the concentration of 1g/l and maintained at room temperature was studied in the laboratory over a period of 12 weeks. The suspension was placed in a latex bag hanging inside a 1000-ml beaker tightly covered with nylon netting, and left there with no changes for 85 days. Sixteen groups of R. prolixus bugs, consisting on average of 30 specimens each, were successively exposed to the bait and observed at different intervals for one week each. The mortality rate was 100% for all groups, except for the 16th, whose mortality rate was 96.7%. As the groups succeeded one another, mortality started to occur more rapidly and was more marked at the 6- and 24-h intervals. Later tests respectively started at 6:00 a.m. and 6:00 p.m. showed that diurnal and nocturnal periodicity in the offer of food had no effect on mortality. First- and 2nd- instar nymphs and adults male were more sensitive and 5th- instar nymphs were more resistant to the active principle of the bait. PMID:1285256

Lima, M M; Rey, L; de Mello, R P

1992-01-01

331

Selection of USSR foreign similarity regions  

NASA Technical Reports Server (NTRS)

The similarity regions in the United States and Canada were selected to parallel the conditions that affect labeling and classification accuracies in the U.S.S.R. indicator regions. In addition to climate, a significant condition that affects labeling and classification accuracies in the U.S.S.R. is the proportion of barley and wheat grown in a given region (based on sown areas). The following regions in the United States and Canada were determined to be similar to the U.S.S.R. indicator regions: (1) Montana agrophysical unit (APU) 104 corresponds to the Belorussia high barley region; (2) North Dakota and Minnesota APU 20 and secondary region southern Manitoba and Saskatchewan correspond to the Ural RSFSR barley and spring wheat region; (3) Montana APU 23 corresponds to he North Caucasus barley and winter wheat region. Selection criteria included climates, crop type, crop distribution, growth cycles, field sizes, and field shapes.

Disler, J. M. (principal investigator)

1982-01-01

332

Interdisciplinary Interactions in Underground Laboratories  

Microsoft Academic Search

Many of underground facilities, ranging from simple cavities to fully equipped laboratories, have been established worldwide (1) to evaluate the impacts of emplacing nuclear wastes in underground research laboratories (URLs) and (2) to measure rare physics events in deep underground laboratories (DULs). In this presentation, we compare similarities and differences between URLs and DULs in focus of site characterization, in

J. S. Wang; A. Bettini

2010-01-01

333

Acoustic similarity laws for centrifugal fans  

NASA Astrophysics Data System (ADS)

Acoustic similarity laws for fans were experimentally verified. Three, dimensionally similar centrifugal fans of 140, 280 and 560 mm impeller diameter were used. The fans were connected to anechoically terminated discharge ducts. It is shown that the influence of the Reynolds number on the radiated sound pressure is negligible within 140,000 or = Reynolds number or = 2,200,000 which is the range covered by the measurements. This result is in agreement with earlier studies in which the Reynolds number was varied from 14,000 to 450,000. Experimental results support the conclusion that fan noise data which is taken on model fans can be extrapolated to other dimensionally similar fans of different size for arbitrary fan speeds and working fluids, provided that the operating condition and the measurement position are the same.

Neise, W.; Barsikow, B.

1982-02-01

334

Acoustic similarity law for centrifugal fans  

NASA Astrophysics Data System (ADS)

Acoustic similarity laws for fans were experimentally verified. Three, dimensionally similar centrifugal fans of 140, 280 and 560 mm impeller diameter were used. The fans were connected to anechoically terminated discharge ducts. It is shown that the influence of the Reynolds number on the radiated sound pressure is negligible within 140,000 or = Reynolds number or = 2,200,000 which is the range covered by the measurements. This result is in agreement with earlier studies in which the Reynolds number was varied from 14,000 to 450,000. Experimental results support the conclusion that fan noise data which is taken on model fans can be extrapolated to other dimensionally similar fans of different size for arbitrary fan speeds and working fluids, provided that the operating condition and the measurement position are the same.

Neise, W.; Barsikow, B.

1980-08-01

335

Self-similar mitochondrial DNA.  

PubMed

We show that repeated sequences, like palindromes (local repetitions) and homologies between two different nucleotide sequences (motifs along the genome), compose a self-similar (fractal) pattern in mitochondrial DNA. This self-similarity comes from the looplike structures distributed along the genome. The looplike structures generate scaling laws in a pseudorandom DNA walk constructed from the sequence, called a Lévy flight. We measure the scaling laws from the generalized fractal dimension and singularity spectrum for mitochondrial DNA walks for 35 different species. In particular, we report characteristic loop distributions for mammal mitochondrial genomes. PMID:15371639

Oiwa, Nestor N; Glazier, James A

2004-01-01

336

Laboratory measurements of the microwave opacity and vapor pressure of sulfuric acid vapor under simulated conditions for the middle atmosphere of Venus  

NASA Technical Reports Server (NTRS)

Microwave absorption measurements at wavelengths of 13.4 and 3.6 cm were made in gaseous H2SO4 in a CO2 atmosphere under simulated conditions for the Venus middle atmosphere. The results suggest that abundances of gaseous H2SO4 on the order of 15-30 ppm could account for the absorption observed by radio occultation measurements at these wavelengths. They also imply that such abundances would correspond to saturation vapor pressure existing at or above the 46-48-km range, which correlates with the observed cloud base.

Steffes, P. G.

1985-01-01

337

Metal-Metal Interactions in Biological Systems. Part VI. Effect of Some Metal ions on Mortality, Pathogenicity and Reproductivity of Steinernema carpocapsae and Heterorhabditis bacteriophora Entomopathogenic Nematodes under Laboratory Conditions  

Microsoft Academic Search

Effect of Li, Al, Cd, Cu(II), Mn(II), Pb(II), Se(IV) and Zn on entomopathogenic nematodes S. carpocapsae and H. bacteriophora mortality, pathogenicity, and productivity was studied under laboratory conditions. These ions were administered as the sole ions as well as in the Li-Al, Li-Cd, Li-Cu(II), Li-Mn(II), Li-Pb(II), Li-Se(IV) and Li-Zn pairs. Lithium as the sole acting ion exhibited a weak lethal

Magdalena Jaworska; Piotr Tomasik

1999-01-01

338

Bioconcentration of two pharmaceuticals (benzodiazepines) and two personal care products (UV filters) in marine mussels (Mytilus galloprovincialis) under controlled laboratory conditions.  

PubMed

Bioaccumulation is essential for gaining insight into the impact of exposure to organic micropollutants in aquatic fauna. Data are currently available on the bioaccumulation of persistent organic pollutants, but there is very little documentation on the bioaccumulation of pharmaceuticals and personal care products (PPCPs). The bioconcentration of selected PPCPs was studied in marine mussels (Mytilus galloprovincialis). The selected PPCPs were two organic UV filters, i.e., 2-ethylhexyl-4-trimethoxycinnamate (EHMC) and octocrylene (OC), and two benzodiazepines (BZP), i.e., diazepam (DZP) and tetrazepam (TZP). Laboratory experiments were performed in which M. galloprovincialis was exposed to these compounds either directly from water, for the less lipophilic substances (BZP) or via spiked food for lipophilic UV filters. M. galloprovincialis uptook and eliminated BZP following first-order kinetics. The biological half-life (t (1/2)) of TZP was 1.4 days, resulting in a bioconcentration factor of 64 and 99 mL g(-1) dry weight (dw), respectively, for 2.3 and 14.5 ?g L(-1) of exposure, while the biological half-life (t (1/2)) of DZP was 0.4 days, resulting in a bioconcentration factor of 51 mL g(-1) dw for 13.2 ?g L(-1) of exposure. The uptake of UV filter was rapid in mussels, followed by elimination within 24 h. EHMC increased from 15 to 138 ng g(-1) dw in 1 h and decreased to 25 ng g(-1) after 24 h for 11.9 ?g L(-1) exposure. OC reached 839 ng g(-1) dw after 1 h and decreased to 33 ng g(-1) after 24 h for 11.6 ?g L(-1) exposure. However, EHMC and OC were slightly accumulated in 48 h, i.e., 38 and 60 ng g(-1) dw, respectively. PMID:22828885

Gomez, Elena; Bachelot, Morgane; Boillot, Clotilde; Munaron, Dominique; Chiron, Serge; Casellas, Claude; Fenet, Hélène

2011-08-01

339

Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1989 through 1991  

SciTech Connect

Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains a continuous monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1989-91. Water in the eastern Snake River Plain aquifer moves principally through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged principally from irrigation water, infiltration of streamflow, and ground-water inflow from adjoining mountain drainage basins. Water levels in wells throughout the INEL generally declined during 1989-91 due to drought. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INEL decreased or remained constant during 1989-91. Decreased concentrations are attributed to reduced rates of radioactive-waste disposal, sorption processes, radioactive decay, and changes in waste-disposal practices. Detectable concentrations of chemical constituents in water from the Snake River Plain aquifer at the INEL were variable during 1989-91. Sodium and chloride concentrations in the southern part of the INEL increased slightly during 1989-91 because of increased waste-disposal rates and a lack of recharge from the Big Lost River. Plumes of 1,1,1-trichloroethane have developed near the Idaho Chemical Processing Plant and the Radioactive Waste Management Complex as a result of waste disposal practices.

Bartholomay, R.C.; Orr, B.R.; Liszewski, M.J.; Jensen, R.G.

1995-08-01

340

Emissions and climate-relevant optical properties of pollutants emitted from a three-stone fire and the Berkeley-Darfur stove tested under laboratory conditions.  

PubMed

Cooking in the developing world generates pollutants that endanger the health of billions of people and contribute to climate change. This study quantified pollutants emitted when cooking with a three-stone fire (TSF) and the Berkeley-Darfur Stove (BDS), the latter of which encloses the fire to increase fuel efficiency. The stoves were operated at the Lawrence Berkeley National Laboratory testing facility with a narrow range of fuel feed rates to minimize performance variability. Fast (1 Hz) measurements of pollutants enabled discrimination between the stoves' emission profiles and development of woodsmoke-specific calibrations for the aethalometer (black carbon, BC) and DustTrak (fine particles, PM2.5). The BDS used 65±5% (average±95% confidence interval) of the wood consumed by the TSF and emitted 50±5% of the carbon monoxide emitted by the TSF for an equivalent cooking task, indicating its higher thermal efficiency and a modest improvement in combustion efficiency. The BDS reduced total PM2.5 by 50% but achieved only a 30% reduction in BC emissions. The BDS-emitted particles were, therefore, more sunlight-absorbing: the average single scattering albedo at 532 nm was 0.36 for the BDS and 0.47 for the TSF. Mass emissions of PM2.5 and BC varied more than emissions of CO and wood consumption over all tests, and emissions and wood consumption varied more among TSF than BDS tests. The international community and the Global Alliance for Clean Cookstoves have proposed performance targets for the highest tier of cookstoves that correspond to greater reductions in fuel consumption and PM2.5 emissions of approximately 65% and 95%, respectively, compared to baseline cooking with the TSF. Given the accompanying decrease in BC emissions for stoves that achieve this stretch goal and BC's extremely high global warming potential, the short-term climate change mitigation from avoided BC emissions could exceed that from avoided CO2 emissions. PMID:24684487

Preble, Chelsea V; Hadley, Odelle L; Gadgil, Ashok J; Kirchstetter, Thomas W

2014-06-01

341

Hydrologic conditions and distribution of selected chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1986 to 1988  

SciTech Connect

Detectable concentrations of radionuclide- and chemical-waste constituents in water from the Snake River Plain aquifer at the Idaho National Engineering Laboratory decreased during 1986--1988. Decreased radionuclide concentrations are attributed to reduced rates of radionuclide-waste disposal, sorption processes, radioactive decay, dilution from recharge, and changes in waste-disposal practices. Tritium concentrations in aquifer water and strontium-90 concentrations decreased. Cobalt-60 and cesium-137 concentrations exceeded the reporting level in water from only one well during 1986--1988. in 1988, concentrations of plutonium-238 and plutonium-239, -240 (undivided) in water from the Test Area North disposal well were 0.19 {plus minus} 0.05 pCi/L and O.96 {plus minus} 0.08 pCi/L, respectively. The concentration of plutonium-238 in well CFA-1 was 0.11 {plus minus} 0.03 pCi/L in 1987. In subsequent samples, concentrations were less than the reporting level. Sodium, chloride, and nitrate plumes originating from the Idaho Chemical Processing Plant decreased in size since use of the ICPP disposal well was discontinued in 1984. During 1986--1988, the approximate areal extent of the sodium plume decreased from 6.8 to 2.5 square miles, the chloride plume decreased from 17 to 5.2 square miles, and the nitrate plume decreased from 14 to 5 square miles. In 1987, water from wells 65 and 89 contained 280 and 50 {mu}g/L, respectively, of chromium; other water samples contained from less than 1 to 30 {mu}g/L. 52 refs., 17 figs., 3 tabs.

Orr, B.R.; Cecil, L.D. (Geological Survey, Idaho Falls, ID (United States). Water Resources Div.)

1991-03-01

342

Learning Summarization by Using Similarities.  

ERIC Educational Resources Information Center

Discusses a research project aimed at designing a computer-based system to help students learn to summarize French texts by using a method called Case-Based Reasoning (CBR). Such a system uses previous, similar situations to make a new summary by reusing and adapting the same summarization rules. The rationale underlying the learning of text…

Capus, Laurence; Tourigny, Nicole

1998-01-01

343

Some Similarities Associated with Pedals  

Microsoft Academic Search

The pedals of a point divide the sides of a triangle into six segments. We build on these segments six squares and obtain some interesting similarities. Given a triangle ABC, the pedals of a point P are its orthogonal projections A, B, C on the sidelines BC, CA, AB of the triangle. We build on the segments AC, CB, BA,

Jean-Pierre Ehrmann; Floor van Lamoen

344

What Difference Reveals about Similarity  

ERIC Educational Resources Information Center

Detecting that two images are different is faster for highly dissimilar images than for highly similar images. Paradoxically, we showed that the reverse occurs when people are asked to describe "how" two images differ--that is, to state a difference between two images. Following structure-mapping theory, we propose that this disassociation arises…

Sagi, Eyal; Gentner, Dedre; Lovett, Andrew

2012-01-01

345

Rating News Documents for Similarity.  

ERIC Educational Resources Information Center

Discussion of electronic news available on the World Wide Web focuses on a methodology of associating news documents using similarity measures and a name-phrase algorithm to create news representations that can be compared and ranked to find related news items. Considers precision over recall and interactivity with the users. (Author/LRW)

Watters, Carolyn; Wang, Hong

2000-01-01

346

Similarity Methods for Differential Equations.  

National Technical Information Service (NTIS)

We begin with a few remarks on the scope of these lecture notes. The purpose is to give an elementary introduction to similarity methods for partial differential equations for those who have had little or nor experience with these techniques. The emphasis...

D. Logan

1982-01-01

347

Similarity methods for differential equations  

Microsoft Academic Search

We begin with a few remarks on the scope of these lecture notes. The purpose is to give an elementary introduction to similarity methods for partial differential equations for those who have had little or nor experience with these techniques. The emphasis will be on motivation and practical calculations involving several simple examples. From time-to-time we will allude to the

Logan

1982-01-01

348

What causes similarity in catchments?  

NASA Astrophysics Data System (ADS)

One of the biggest issues in hydrology is how to handle the heterogeneity of catchment properties at different scales. But is this really such a big issue? Is this problem not merely the consequence of how we conceptualise and how we model catchments? Is there not far more similarity than we observe. Maybe we are not looking at the right things or at the right scale to see the similarity. The identity of catchments is largely determined by: the landscape, the ecosystem living on the landscape, and the geology, in that order. Soils, which are often seen as a crucial aspect of hydrological behaviour, are far less important, as will be demonstrated. The main determinants of hydrological behaviour are: the landscape composition, the rooting depth and the phenology. These determinants are a consequence of landscape and ecosystem evolution, which, in turn, are the manifestations of entropy production. There are striking similarities between catchments. The different runoff processes from hillslopes are linked and similar in different environments (McDonnell, 2013). Wetlands behave similarly all over the world. The key is to classify landscapes and to link the ecosystems living on them to climate. The ecosystem then is the main controller of hydrological behaviour. Besides phenology, the rooting depth is key in determining runoff behaviour. Both are strongly linked to climate and much less to soil properties. An example is given of how rooting depth is determined by climate, and how rooting depth can be predicted without calibration, providing a strong constraints on the prediction of rainfall partitioning and catchment runoff.

Savenije, Hubert

2014-05-01

349

FINAL REPORT - Biogeochemistry of Uranium Under Reducing and Re-oxidizing Conditions:An Integrated Laboratory and Field Study and Acceptable Endpoints for Metals and Radionuclides: Quantifying the Stability of Uranium and Lead Immobilized Under Sulfate Reducing Conditions  

SciTech Connect

Our understanding of subsurface microbiology is hindered by the inaccessibility of this environment, particularly when the hydrogeologic medium is contaminated with toxic substances. Research in our labs indicated that the composition of the growth medium (e.g., bicarbonate complexation of U(VI)) and the underlying mineral phase (e.g., hematite) significantly affects the rate and extent of U(VI) reduction and immobilization through a variety of effects. Our research was aimed at elucidating those effects to a much greater extent, while exploring the potential for U(IV) reoxidation and subsequent re-mobilization, which also appears to depend on the mineral phases present in the system. In situ coupons with a variety of mineral phases were placed in monitoring wells at the NABIR FRC. These coupons showed that the mineral phase composition significantly affected the resulting attached phase microbial community. Our comparative use of both batch and open flow reactors (more representative of field conditions) indicates that hydrodynamics and continual influx of substrate and contaminants can also yield significantly different results than those obtained with closed serum bottles. To this end, the following overall experimental hypothesis tested was the following: On a mineral surface under anaerobic conditions, accumulations of secondary inorganic precipitates are controlled by a) the bacteria associated with the mineral surface, b) the electron acceptors available for anaerobic bacterial respiration, and c) local hydrodynamics and pH buffers govern micro- and meso-scale interaction of U in the presence of electron donors and acceptors, and nutrients.

Brent Peyton; James Amonette; Haluk Beyenal; Gill Geesey; Zbigniew Lewandowski; Rajesh Sani

2005-10-07

350

Color Similarity in Children's Classifications and Extensions of Object Labels.  

ERIC Educational Resources Information Center

A study investigated whether children expect color similarity to be less important than form similarity in object label extensions. Twenty 2-year-olds and 20 3-year-olds were asked to sort objects similar in either color or form in two different situations: (1) the "No Label" condition where children were asked to help the puppet put objects that…

Baldwin, Dare A.

351

Perifosine Laboratory Information  

Cancer.gov

CONFIDENTIAL KRX 401 Technical Data Perifosine (NSC 639966 ) Laboratory Information Information on Clinical Conditions1 Topic Conditions Comments References Stock solution Solutions of 0.1-30 µM perifosine were diluted with 100 mM PBS Stable enough

352

Effects of experimental manipulations of salinity and maturation status on the physiological condition and mortality of homing adult sockeye salmon held in a laboratory.  

PubMed

Relatively little is known about the physiological response and mortality consequences of the return of anadromous fish to freshwater (FW). We explored the consequences of the return to FW by collecting maturing sockeye salmon from the marine waters off the mouth of the Fraser River and holding approximately 50 sockeye in each of five treatments: saltwater (SW; salinity = 28 ppt), iso-osmotic water (ISO; 13 ppt), FW (0 ppt), SW + gonadotropin-releasing hormone (SW + GnRH), and FW + GnRH. Exogenous GnRH treatments were intended to accelerate maturation. Results demonstrate that gill Na(+),K(+) ATPase activity, sex steroid concentrations, and cortisol levels were highly responsive to experimental manipulations and followed predicted trajectories (i.e., FW + GnRH sockeye were the most mature and FW adapted). There were few among-treatment differences in hematocrit and plasma concentrations of lactate, glucose, Na(+), Cl(-), and plasma osmolality among sockeye that survived to the end of treatments, indicating that sockeye rigorously maintain internal homeostatic conditions while alive. There were large among-treatment differences in mortality (SW+GnRH > SW> FW+GnRH > FW=ISO), and each treatment experienced a notable increase in mortality rate around the fifth day of treatment. Our results indicate that salinity represented a modestly larger challenge to the experimental sockeye than did the artificially accelerated sexual maturation. Our results also suggest that maturing sockeye either successfully acclimate to FW within 5 d of exposure or perish. These findings are consistent with the predictions of the theory of anadromy, in suggesting that the return of adults to FW can be physiologically challenging and can represent a period of significant natural mortality. PMID:20345242

Cooperman, M S; Hinch, S G; Crossin, G T; Cooke, S J; Patterson, D A; Olsson, I; Lotto, A G; Welch, D W; Shrimpton, J M; Van Der Kraak, G; Farrell, A P

2010-01-01

353

Exploration Laboratory Analysis - ARC  

NASA Technical Reports Server (NTRS)

The Exploration Laboratory Analysis (ELA) project supports the Exploration Medical Capability (ExMC) risk, Risk of Inability to Adequately Treat an Ill or Injured Crew Member, and ExMC Gap 4.05: Lack of minimally invasive in-flight laboratory capabilities with limited consumables required for diagnosing identified Exploration Medical Conditions. To mitigate this risk, the availability of inflight laboratory analysis instrumentation has been identified as an essential capability in future exploration missions. Mission architecture poses constraints on equipment and procedures that will be available to treat evidence-based medical conditions according to the Space Medicine Exploration Medical Conditions List (SMEMCL). The SMEMCL provided diagnosis and treatment for the evidence-based medical conditions and hence, a basis for developing ELA functional requirements.

Krihak, Michael K.; Fung, Paul P.

2012-01-01

354

Path similarity skeleton graph matching.  

PubMed

This paper presents a novel framework to for shape recognition based on object silhouettes. The main idea is to match skeleton graphs by comparing the shortest paths between skeleton endpoints. In contrast to typical tree or graph matching methods, we completely ignore the topological graph structure. Our approach is motivated by the fact that visually similar skeleton graphs may have completely different topological structures. The proposed comparison of shortest paths between endpoints of skeleton graphs yields correct matching results in such cases. The skeletons are pruned by contour partitioning with Discrete Curve Evolution, which implies that the endpoints of skeleton branches correspond to visual parts of the objects. The experimental results demonstrate that our method is able to produce correct results in the presence of articulations, stretching, and occlusion. PMID:18550909

Bai, Xiang; Latecki, Longin Jan

2008-07-01

355

Similarity indexing: algorithms and performance  

NASA Astrophysics Data System (ADS)

Efficient indexing support is essential to allow content-based image and video databases using similarity-based retrieval to scale to large databases (tens of thousands up to millions of images). In this paper, we take an in depth look at this problem. One of the major difficulties in solving this problem is the high dimension (6-100) of the feature vectors that are used to represent objects. We provide an overview of the work in computational geometry on this problem and highlight the results we found are most useful in practice, including the use of approximate nearest neighbor algorithms. We also present a variant of the optimized k-d tree we call the VAM k-d tree, and provide algorithms to create an optimized R-tree we call the VAMSplit R-tree. We found that the VAMSplit R-tree provided better overall performance than all competing structures we tested for main memory and secondary memory applications. We observed large improvements in performance relative to the R*-tree and SS-tree in secondary memory applications, and modest improvements relative to optimized k-d tree variants.

White, David A.; Jain, Ramesh C.

1996-03-01

356

Self-similarity in nature  

NASA Astrophysics Data System (ADS)

A general phenomenological approach to the analysis of experimental temporal, spatial and energetic series for extracting truly physical non-model parameters (``passport data'') is presented, which may be used to characterize and distinguish the evolution as well as the spatial and energetic structure of any open nonlinear dissipative system. This methodology is based on a postulate concerning the crucial information contained in the sequences of non-regularities of the measured dynamic variable (temporal, spatial, energetic). In accordance with this approach, multi-parametric formulas for dynamic variable power spectra as well as for structural functions of different orders are identical for every spatial-temporal-energetic level of the system under consideration. In effect, this entails the introduction of a new kind of self-similarity in Nature. An algorithm has been developed for obtaining as many ``passport data'' as are necessary for the characterization of a dynamic system. Applications of this approach in the analysis of various experimental series (temporal, spatial, energetic) demonstrate its potential for defining adequate phenomenological parameters of different dynamic processes and structures. .

Timashev, S. F.

2000-02-01

357

LANGUAGE LABORATORIES.  

ERIC Educational Resources Information Center

THE USE OF THE LANGUAGE LABORATORY HAS GIVEN MANY THOUSANDS OF INDIVIDUALS GOOD LISTENING AND SPEAKING PRACTICE AND HAS BECOME AN EFFECTIVE LEARNING TOOL. THE BASIC PIECE OF EQUIPMENT OF THE LANGUAGE LABORATORY IS THE TAPE RECORDER-AND-PLAYBACK, DESIGNED TO BE USED WITH AUDIOPASSIVE STUDY, AUDIOACTIVE STUDY, AUDIOACTIVE-COMPARATIVE STUDY, AND…

BRUBAKER, CHARLES WILLIAM

358

Evaluation of Mycology Laboratory Proficiency Testing  

PubMed Central

Changes over the last decade in overt proficiency testing (OPT) regulations have been ostensibly directed at improving laboratory performance on patient samples. However, the overt (unblinded) format of the tests and regulatory penalties associated with incorrect values allow and encourage laboratorians to take extra precautions with OPT analytes. As a result OPT may measure optimal laboratory performance instead of the intended target of typical performance attained during routine patient testing. This study addresses this issue by evaluating medical mycology OPT and comparing its fungal specimen identification error rates to those obtained in a covert (blinded) proficiency testing (CPT) program. Identifications from 188 laboratories participating in the New York State mycology OPT from 1982 to 1994 were compared with the identifications of the same fungi recovered from patient specimens in 1989 and 1994 as part of the routine procedures of 88 of these laboratories. The consistency in the identification of OPT specimens was sufficient to make accurate predictions of OPT error rates. However, while the error rates in OPT and CPT were similar for Candida albicans, significantly higher error rates were found in CPT for Candida tropicalis, Candida glabrata, and other common pathogenic fungi. These differences may, in part, be due to OPT’s use of ideal organism representatives cultured under optimum growth conditions. This difference, as well as the organism-dependent error rate differences, reflects the limitations of OPT as a means of assessing the quality of routine laboratory performance in medical mycology.

Reilly, Andrew A.; Salkin, Ira F.; McGinnis, Michael R.; Gromadzki, Sally; Pasarell, Lester; Kemna, Maggi; Higgins, Nancy; Salfinger, Max

1999-01-01

359

Accreditation or Certification for Laboratories?  

NASA Astrophysics Data System (ADS)

This presentation is focused on explaining the significance of accreditation and certification for laboratories and illustrates the usefulness of both procedures. The implementation of these procedures in laboratories is described, pointing out their similarities and differences. Reference is made to some publications. The discussion reflects the existing practice.

Tsimillis, Kyriacos C.

360

Measure preserving Markov processes densely similar to endomorphisms  

NASA Astrophysics Data System (ADS)

We characterize the contractions densely similar to the adjoint of some isometry. We deduce a sufficient condition in order to have the evolution of a measure preserving Markov process densely similar to the evolution of an endomorphism on the set of L 2-states. This study is in the scope of the reciprocal of the Misra-Prigogine construction in K-systems.

Bertoglio, Néstor; Martínez, Servet

1991-01-01

361

Emergent self-similarity of cluster coagulation  

NASA Astrophysics Data System (ADS)

A wide variety of nonequilibrium processes, such as coagulation of colloidal particles, aggregation of bacteria into colonies, coalescence of rain drops, bond formation between polymerization sites, and formation of planetesimals, fall under the rubric of cluster coagulation. We predict emergence of self-similar behavior in such systems when they are 'forced' by an external source of the smallest particles. The corresponding self-similar coagulation spectra prove to be power laws. Starting from the classical Smoluchowski coagulation equation, we identify the conditions required for emergence of self-similarity and show that the power-law exponent value for a particular coagulation mechanism depends on the homogeneity index of the corresponding coagulation kernel only. Next, we consider the current wave of mergers of large American banks as an 'unorthodox' application of coagulation theory. We predict that the bank size distribution has propensity to become a power law, and verify our prediction in a statistical study of the available economical data. We conclude this chapter by discussing economically significant phenomenon of capital condensation and predicting emergence of power-law distributions in other economical and social data. Finally, we turn to apparent semblance between cluster coagulation and turbulence and conclude that it is not accidental: both of these processes are instances of nonlinear cascades. This class of processes also includes river network formation models, certain force-chain models in granular mechanics, fragmentation due to collisional cascades, percolation, and growing random networks. We characterize a particular cascade by three indicies and show that the resulting power-law spectrum exponent depends on the indicies values only. The ensuing algebraic formula is remarkable for its simplicity.

Pushkin, Dmtiri O.

362

Similarity Scaling Over a Steep Alpine Slope  

NASA Astrophysics Data System (ADS)

In this study, we investigate the validity of similarity scaling over a steep mountain slope (30-41^circ ). The results are based on eddy-covariance data collected during the Slope Experiment near La Fouly (SELF-2010); a field campaign conducted in a narrow valley of the Swiss Alps during summer 2010. The turbulent fluxes of heat and momentum are found to vary significantly with height in the first few metres above the inclined surface. These variations exceed by an order of magnitude the well-accepted maximum 10 % required for the applicability of Monin-Obukhov similarity theory in the surface layer. This could be due to a surface layer that is too thin to be detected or to the presence of advective fluxes. It is shown that local scaling can be a useful tool in these cases when surface-layer theory breaks down. Under convective conditions and after removing the effects of self-correlation, the normalized standard deviations of slope-normal wind velocity, temperature and humidity scale relatively well with z/\\varLambda , where z is the measurement height and \\varLambda (z) the local Obukhov length. However, the horizontal velocity fluctuations are not correlated with z/\\varLambda under all stability regimes. The non-dimensional gradients of wind velocity and temperature are also investigated. For those, the local scaling appears inappropriate, particularly at night when shallow drainage flows prevail and lead to negative wind-speed gradients close to the surface.

Nadeau, Daniel F.; Pardyjak, Eric R.; Higgins, Chad W.; Parlange, Marc B.

2013-06-01

363

Laboratory Studies of Interstellar PAH Analogs  

NASA Technical Reports Server (NTRS)

Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a closer simulation of space environments and a better support to space missions.

Salama, Farid; DeVincenzi, Donald (Technical Monitor)

2000-01-01

364

Drug-induced acne and rose pearl: similarities.  

PubMed

Drug-induced acne is a common skin condition whose classic symptoms can be similar to a rose pearl, as in the case of a male patient presenting with this condition after excessive use of a cream containing corticosteroids. PMID:24474128

Pontello, Rubens; Kondo, Rogerio Nabor

2013-01-01

365

Laboratory blast wave driven instabilities  

NASA Astrophysics Data System (ADS)

This presentation discusses experiments involving the evolution of hydrodynamic instabilities in the laboratory under high-energy-density (HED) conditions. These instabilities are driven by blast waves, which occur following a sudden, finite release of energy, and consist of a shock front followed by a rarefaction wave. When a blast wave crosses an interface with a decrease in density, hydrodynamic instabilities will develop. Instabilities evolving under HED conditions are relevant to astrophysics. These experiments include target materials scaled in density to the He/H layer in SN1987A. About 5 kJ of laser energy from the Omega Laser facility irradiates a 150 ?m plastic layer that is followed by a low-density foam layer. A blast wave structure similar to those in supernovae is created in the plastic layer. The blast wave crosses an interface having a 2D or 3D sinusoidal structure that serves as a seed perturbation for hydrodynamic instabilities. This produces unstable growth dominated by the Rayleigh-Taylor (RT) instability in the nonlinear regime. We have detected the interface structure under these conditions using x-ray backlighting. Recent advances in our diagnostic techniques have greatly improved the resolution of our x-ray radiographic images. Under certain conditions, the improved images show some mass extending beyond the RT spike and penetrating further than previously observed or predicted by current simulations. The observed effect is potentially of great importance as a source of mass transport to places not anticipated by current theory and simulation. I will discuss the amount of mass in these spike extensions, the associated uncertainties, and hypotheses regarding their origin We also plan to show comparisons of experiments using single mode and multimode as well as 2D and 3D initial conditions. This work is sponsored by DOE/NNSA Research Grants DE-FG52-07NA28058 (Stewardship Sciences Academic Alliances) and DE-FG52-04NA00064 (National Laser User Facility).

Kuranz, Carolyn

2008-11-01

366

Similarity constraints in testing of cooled engine parts  

NASA Technical Reports Server (NTRS)

A study is made of the effect of testing cooled parts of current and advanced gas turbine engines at the reduced temperature and pressure conditions which maintain similarity with the engine environment. Some of the problems facing the experimentalist in evaluating heat transfer and aerodynamic performance when hardware is tested at conditions other than the actual engine environment are considered. Low temperature and pressure test environments can simulate the performance of actual size prototype engine hardware within the tolerance of experimental accuracy if appropriate similarity conditions are satisfied. Failure to adhere to these similarity constraints because of test facility limitations or other reasons, can result in a number of serious errors in projecting the performance of test hardware to engine conditions.

Colladay, R. S.; Stepka, F. S.

1974-01-01

367

Appalachian Laboratory  

NSDL National Science Digital Library

Located in Frostburg, Maryland, AL conducts research in aquatic ecology, landscape and watershed ecology, conservation biology and restoration ecology, behavioral and evolutionary ecology, and study both freshwater and terrestrial ecosystems of Maryland and other locations in the United States and the world. Site contains information regarding the facilities, faculty, on going research, education opportunities, and seminars. Also features information on the other UMCES laboratories.

368

Appalachian Laboratory  

NSDL National Science Digital Library

Located in Frostburg, Maryland, AL conducts research in aquatic ecology, landscape and watershed ecology, conservation biology and restoration ecology, behavioral and evolutionary ecology, and study both freshwater and terrestrial ecosystems of Maryland and other locations in the United States and the world. Site contains information regarding the facilities, faculty, on going research, education opportunities, and seminars. Also features information on the other UMCES laboratories.

2011-06-14

369

Thematic Relations Affect Similarity Via Commonalities  

Microsoft Academic Search

Thematic relations are an important source of perceived similarity. For instance, the rowing theme of boats and oars increases their perceived similarity. The mechanism of this effect, however, has not been specified previously. The authors investigated whether thematic relations affect similarity by increasing commonalities or by decreasing differences. In Experiment 1, thematic relations affected similarity more than difference, thereby producing

Sabrina Golonka; Zachary Estes

2009-01-01

370

Emergency Procedure Training for Reactor Operators at the High Flux Beam Reactor for Brookhaven National Laboratory.  

ERIC Educational Resources Information Center

A project was conducted to analyze, design, develop, implement, and evaluate an instructional unit intended to improve the diagnostic skills of operating personnel in responding to abnormal and emergency conditions at the High Flux Beam Reactor at Brookhaven National Laboratory. Research was conducted on the occurrence of emergencies at similar

Reyer, Ronald

371

Complicated self-similarity of terrain surface  

NASA Astrophysics Data System (ADS)

Fractal describes the self-similar phenomenon of signal and self-similarity is the most important character of fractal. Pentland provides an excellent explanation of the ruggedness of natural surface. Fractal-based description of image texture has been used effectively in characterization and segmentation of natural scene. A real surface is self-similar over some range of scales, rather than over all scales. That imply self-similarity of a terrain surface is not always so perfect that keep invariable in whole scale space. To describe such self-similarity distribution, a self-similarity curve could be plotted and was divided into several linear regions. We present a new parameter called Self-similarity Degree (SD) in the similitude of information entropy to denote such self-similarity distribution. In addition, one general characterization of self-similarities is result of physical processes. Terrain surface are created by the interactional inogenic and exogenic processes. Hereby, we introduce self-similarity analysis and multifractal singularity spectrum to describe such complex physical field. By the self-similarity analysis and singularity spectrum, the different self-similar structures and the interaction of processes in terrain surface were depicted. Our studies have shown that self-similarity is a relative notion and natural scenes own abundant self-similar structures. Moreover, noises always destroy the self-similarity of original natural surface and change the singularity distribution of original surface.

Li, Xutao; Cao, Hanqiang; Zhu, Guangxi; Wang, Shouyong

2005-11-01

372

Lunar laboratory  

SciTech Connect

An international research laboratory can be established on the Moon in the early years of the 21st Century. It can be built using the transportation system now envisioned by NASA, which includes a space station for Earth orbital logistics and orbital transfer vehicles for Earth-Moon transportation. A scientific laboratory on the Moon would permit extended surface and subsurface geological exploration; long-duration experiments defining the lunar environment and its modification by surface activity; new classes of observations in astronomy; space plasma and fundamental physics experiments; and lunar resource development. The discovery of a lunar source for propellants may reduce the cost of constructing large permanent facilities in space and enhance other space programs such as Mars exploration. 29 refs.

Keaton, P.W.; Duke, M.B.

1986-01-01

373

Fetal Conditions, Abnormalities and Diagnoses  

MedlinePLUS

... Services Clinical Studies Quick Links Continuing Medical Education Nursing Newsletters Conditions MyChart Neighborhood Locations Outcomes and Quality Family-Centered Rounds Clinical Laboratories Researchers ...

374

Laboratory accreditation  

SciTech Connect

Accreditation can offer many benefits to a testing or calibration laboratory, including increased marketability of services, reduced number of outside assessments, and improved quality of services. Compared to ISO 9000 registration, the accreditation process includes a review of the entire quality system, but in addition a review of testing or calibration procedures by a technical expert and participation in proficiency testing in the areas of accreditation. Within the DOE, several facilities have recently become accredited in the area of calibration, including Sandia National Laboratories, Oak Ridge, AlliedSignal FM and T; Lockheed Martin Idaho Technologies Co., and Pacific Northwest National Lab. At the national level, a new non-profit organization was recently formed called the National Cooperation for Laboratory Accreditation (NACLA). The goal of NACLA is to develop procedures, following national and international requirements, for the recognition of competent accreditation bodies in the US. NACLA is a voluntary partnership between the public and private sectors with the goal of a test or calibration performed once and accepted world wide. The NACLA accreditation body recognition process is based on the requirements of ISO Guide 25 and Guide 58. A membership drive will begin some time this fall to solicit organizational members and an election of a permanent NACLA Board of Directors will follow later this year or early 1999.

Pettit, R.B.

1998-08-01

375

Exploring perceptually similar cases with multi-dimensional scaling  

NASA Astrophysics Data System (ADS)

Retrieving a set of known lesions similar to the one being evaluated might be of value for assisting radiologists to distinguish between benign and malignant clustered microcalcifications (MCs) in mammograms. In this work, we investigate how perceptually similar cases with clustered MCs may relate to one another in terms of their underlying characteristics (from disease condition to image features). We first conduct an observer study to collect similarity scores from a group of readers (five radiologists and five non-radiologists) on a set of 2,000 image pairs, which were selected from 222 cases based on their images features. We then explore the potential relationship among the different cases as revealed by their similarity ratings. We apply the multi-dimensional scaling (MDS) technique to embed all the cases in a 2-D plot, in which perceptually similar cases are placed in close vicinity of one another based on their level of similarity. Our results show that cases having different characteristics in their clustered MCs are accordingly placed in different regions in the plot. Moreover, cases of same pathology tend to be clustered together locally, and neighboring cases (which are more similar) tend to be also similar in their clustered MCs (e.g., cluster size and shape). These results indicate that subjective similarity ratings from the readers are well correlated with the image features of the underlying MCs of the cases, and that perceptually similar cases could be of diagnostic value for discriminating between malignant and benign cases.

Wang, Juan; Yang, Yongyi; Wernick, Miles N.; Nishikawa, Robert M.

2014-03-01

376

Monitoring quality requires knowing similarity: the NICLTS experience.  

PubMed Central

Laboratory tests can appear similar from the test names but may be vastly different in the way a result is achieved. Currently, for example, cervical cancer evaluation is moving from the traditional Papanicolaou smear to new smear preparation technologies and testing for human papillomavirus. Monitoring the quality of these three tests, and of all tests, requires that computers "understand" how these tests are similar and different. The National Inventory of Clinical Laboratory Testing Services (NICLTS) found that the approximately 20,000 most commonly performed tests used combinations of 635 analytes and 1,699 methods. These analytes and methods provide the base data for a semantic model that makes the requisite similarities and differences explicit. The semantic relationships, e.g. the method principle enabling a test and the nature of the substance tested, were evaluated against empirically derived, uni-dimensional relations. The resulting multi-dimensional semantic model expands our ability to monitor the quality of laboratory testing in the face of rapid change. Use of common terminology tools and representations enable the creation, expansion and reuse of this model beyond the needs of NICLTS.

Steindel, S. J.; Granade, S. E.

2001-01-01

377

42 CFR 493.1205 - Condition: Virology.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Condition: Virology. 493.1205 Section 493.1205...Testing § 493.1205 Condition: Virology. If the laboratory provides services in the subspecialty of Virology, the laboratory must meet the...

2013-10-01

378

42 CFR 493.1205 - Condition: Virology.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Condition: Virology. 493.1205 Section 493.1205...Testing § 493.1205 Condition: Virology. If the laboratory provides services in the subspecialty of Virology, the laboratory must meet the...

2010-10-01

379

42 CFR 493.1205 - Condition: Virology.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Condition: Virology. 493.1205 Section 493.1205...Testing § 493.1205 Condition: Virology. If the laboratory provides services in the subspecialty of Virology, the laboratory must meet the...

2009-10-01

380

42 CFR 493.1221 - Condition: Cytology.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Condition: Cytology. 493.1221 Section 493.1221...Testing § 493.1221 Condition: Cytology. If the laboratory provides services in the subspecialty of Cytology, the laboratory must meet the...

2013-10-01

381

42 CFR 493.1215 - Condition: Hematology.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Condition: Hematology. 493.1215 Section 493.1215...Testing § 493.1215 Condition: Hematology. If the laboratory provides services in the specialty of Hematology, the laboratory must meet the...

2010-10-01

382

42 CFR 493.1215 - Condition: Hematology.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Condition: Hematology. 493.1215 Section 493.1215...Testing § 493.1215 Condition: Hematology. If the laboratory provides services in the specialty of Hematology, the laboratory must meet the...

2013-10-01

383

42 CFR 493.1215 - Condition: Hematology.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Condition: Hematology. 493.1215 Section 493.1215...Testing § 493.1215 Condition: Hematology. If the laboratory provides services in the specialty of Hematology, the laboratory must meet the...

2009-10-01

384

42 CFR 493.1204 - Condition: Parasitology.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Condition: Parasitology. 493.1204 Section 493...Testing § 493.1204 Condition: Parasitology. If the laboratory provides services in the subspecialty of Parasitology, the laboratory must meet the...

2009-10-01

385

42 CFR 493.1204 - Condition: Parasitology.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Condition: Parasitology. 493.1204 Section 493...Testing § 493.1204 Condition: Parasitology. If the laboratory provides services in the subspecialty of Parasitology, the laboratory must meet the...

2013-10-01

386

42 CFR 493.1204 - Condition: Parasitology.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Condition: Parasitology. 493.1204 Section 493...Testing § 493.1204 Condition: Parasitology. If the laboratory provides services in the subspecialty of Parasitology, the laboratory must meet the...

2010-10-01

387

42 CFR 493.1213 - Condition: Toxicology.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Condition: Toxicology. 493.1213 Section 493.1213...Testing § 493.1213 Condition: Toxicology. If the laboratory provides services in the subspecialty of Toxicology, the laboratory must meet the...

2009-10-01

388

42 CFR 493.1203 - Condition: Mycology.  

Code of Federal Regulations, 2010 CFR

...2009-10-01 false Condition: Mycology. 493.1203 Section 493.1203...Testing § 493.1203 Condition: Mycology. If the laboratory provides services in the subspecialty of Mycology, the laboratory must meet the...

2009-10-01

389

42 CFR 493.1203 - Condition: Mycology.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Condition: Mycology. 493.1203 Section 493.1203...Testing § 493.1203 Condition: Mycology. If the laboratory provides services in the subspecialty of Mycology, the laboratory must meet the...

2013-10-01

390

42 CFR 493.1203 - Condition: Mycology.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Condition: Mycology. 493.1203 Section 493.1203...Testing § 493.1203 Condition: Mycology. If the laboratory provides services in the subspecialty of Mycology, the laboratory must meet the...

2010-10-01

391

Similarity solutions of boundary layer equations for second order fluids  

NASA Astrophysics Data System (ADS)

An isovector derived via exterior calculus for the boundary layers of second-order fluids is presently used to ascertain the ordinary differential equations that lead to the similarity solutions. Taking the problem as an initial-value problem, an effort is made to find the arbitrary condition by resort to the shooting method. The shear stress of the similarity solution is calculated, together with the profile corresponding to the solution.

Pakdemirli, M.; Suhubi, E. S.

1992-05-01

392

7 CFR 51.1997 - Similar type.  

Code of Federal Regulations, 2010 CFR

...CERTIFICATION, AND STANDARDS) United States Standards for Grades of Filberts in the Shell 1 Definitions § 51.1997 Similar type. Similar type means that the filberts in each container are of the same general type and appearance. For...

2010-01-01

393

Archimedes Laboratory  

NSDL National Science Digital Library

Proving that geometry can be more fun than a barrel of monkeys, Archimedes Laboratory is "an 'intuitive' puzzle site with fewer formulas and more visuals, which may encourage students learning this science or just constitute a platform for reflection." Probably the most strictly educational section of the site is Math to Discover, which contains discussions of the history of numbers and mathematical patterns, to name a few. Also of interest are the Puzzles to Make and Puzzles to Solve sections. Visitors can follow online instructions to create geometrical curiosities or browse a small selection of impossible object images.

394

Tsunamis and meteorological tsunamis: similarities and differences  

Microsoft Academic Search

Destructive seiche oscillations occasionally generated in certain bays and inlets are mainly associated with two natural forcing phenomena: Seismic activity (tsunamis), and atmospheric disturbances (meteotsunamis). Despite their different origin, both types are modified and amplified by topography in a similar way and produce similar catastrophic effects in coastal areas. Due to these similarities, it is often difficult to distinguish between

A. B. Rabinovich; S. Monserrat

2003-01-01

395

Thematic Relations Affect Similarity via Commonalities  

ERIC Educational Resources Information Center

Thematic relations are an important source of perceived similarity. For instance, the "rowing" theme of boats and oars increases their perceived similarity. The mechanism of this effect, however, has not been specified previously. The authors investigated whether thematic relations affect similarity by increasing commonalities or by decreasing…

Golonka, Sabrina; Estes, Zachary

2009-01-01

396

Impact of Similarity Measures on Webpage Clustering  

Microsoft Academic Search

Clustering of web documents enables (semi-)automatedcategorization, and facilitates certain types of search.Any clustering method has to embed the documentsin a suitable similarity space. While several clusteringmethods and the associated similarity measures havebeen proposed in the past, there is no systematic comparativestudy of the impact of similarity metrics oncluster quality, possibly because the popular cost criteriado not readily translate across qualitatively

Er Strehl; Joydeep Ghosh; Raymond Mooney

2000-01-01

397

Exploiting hierarchical domain structure to compute similarity  

Microsoft Academic Search

The notion of similarity between objects finds use in many contexts, for example, in search engines, collaborative filtering, and clustering. Objects being compared often are modeled as sets, with their similarity traditionally determined based on set intersection. Intersection-based measures do not accurately capture similarity in certain domains, such as when the data is sparse or when there are known relationships

Prasanna Ganesan; Hector Garcia-Molina; Jennifer Widom

2003-01-01

398

Music Similarity Measures: What's the use?  

Microsoft Academic Search

Electronic Music Distribution (EMD) is in demand of robust, automatically extracted music descriptors. We introduce a timbral similarity measures for comparing music titles. This measure is based on a Gaussian model of cepstrum coefficients. We describe the timbre extractor and the corresponding timbral similarity relation. We describe experiments in assessing the quality of the similarity relation, and show that the

Jean-julien Aucouturier; François Pachet

2002-01-01

399

A qualitative characterization of an introductory college nonmajors biology laboratory  

NASA Astrophysics Data System (ADS)

The nature of an undergraduate, nonmajors biology laboratory was investigated in this study. Student participants were enrolled in a general education biology laboratory course at the University of Northern Iowa. The researcher's purpose was to gain a characterization of the instructional format and laboratory activities experienced by students. Interpretation of student and instructor responses enabled an insider's view of the biology laboratory. The laboratory period was consistently described by both students and instructors as having three parts, Beginning, Middle, and End, with the End being of special importance for conceptual development. The instructional format of the three instructors differed within the three portions of the laboratory period, ranging from an inquiry-oriented, partial learning cycle to a fairly expository model labeled inform/verify/practice. There was striking similarity in intrasectional student and teacher descriptions of instructional format. Additionally, students experiencing the alternate instructor provided the same characterizations of instructional format as those provided by the instructor's usual students. There were no discernible patterns of instructional format based on sex or reasoning level. In addition to the central role of instructional format, three areas of importance emerged: the social aspects of learning, the collaborative and cooperative nature of laboratory work and learning, and the role of self-efficacy. Theory developed from and grounded in the data showed six factors important in the introductory college biology laboratory: collaborative and cooperative learning, student-student and teacher-student interactions, attitude and self-efficacy, learning process and learning style, effective instructional format, and science content. These factors were found to be similar to factors identified in the literature as important in K-12 science education. These factors were set in the context of schooling and learning paradigms, paralleling J. J. Schwab's four conditions of a curriculum (subject matter, learners, teachers, and milieus), Benjamin Bloom's model of important factors in student achievement and schooling (cognitive entry behaviors, affective entry behaviors, and quality of instruction), and fitting a constructivist epistemological framework.

Lee, Cherin Ann

400

Cross-reactivity of steroid hormone immunoassays: clinical significance and two-dimensional molecular similarity prediction  

PubMed Central

Background Immunoassays are widely used in clinical laboratories for measurement of plasma/serum concentrations of steroid hormones such as cortisol and testosterone. Immunoassays can be performed on a variety of standard clinical chemistry analyzers, thus allowing even small clinical laboratories to do analysis on-site. One limitation of steroid hormone immunoassays is interference caused by compounds with structural similarity to the target steroid of the assay. Interfering molecules include structurally related endogenous compounds and their metabolites as well as drugs such as anabolic steroids and synthetic glucocorticoids. Methods Cross-reactivity of a structurally diverse set of compounds were determined for the Roche Diagnostics Elecsys assays for cortisol, dehydroepiandrosterone (DHEA) sulfate, estradiol, progesterone, and testosterone. These data were compared and contrasted to package insert data and published cross-reactivity studies for other marketed steroid hormone immunoassays. Cross-reactivity was computationally predicted using the technique of two-dimensional molecular similarity. Results The Roche Elecsys Cortisol and Testosterone II assays showed a wider range of cross-reactivity than the DHEA sulfate, Estradiol II, and Progesterone II assays. 6-Methylprednisolone and prednisolone showed high cross-reactivity for the cortisol assay, with high likelihood of clinically significant effect for patients administered these drugs. In addition, 21-deoxycortisol likely produces clinically relevant cross-reactivity for cortisol in patients with 21-hydroxylase deficiency, while 11-deoxycortisol may produce clinically relevant cross-reactivity in 11?-hydroxylase deficiency or following metyrapone challenge. Several anabolic steroids may produce clinically significant false positives on the testosterone assay, although interpretation is limited by sparse pharmacokinetic data for some of these drugs. Norethindrone therapy may impact immunoassay measurement of testosterone in women. Using two-dimensional similarity calculations, all compounds with high cross-reactivity also showed a high degree of similarity to the target molecule of the immunoassay. Conclusions Compounds producing cross-reactivity in steroid hormone immunoassays generally have a high degree of structural similarity to the target hormone. Clinically significant interactions can occur with structurally similar drugs (e.g., prednisolone and cortisol immunoassays; methyltestosterone and testosterone immunoassays) or with endogenous compounds such as 21-deoxycortisol that can accumulate to very high concentrations in certain disease conditions. Simple similarity calculations can help triage compounds for future testing of assay cross-reactivity.

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