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1

Environmental Conditions Environmental Conditions  

E-print Network

Environmental Conditions Environmental Conditions Appendix II The unique geology, hydrology and instream habitat. This chapter examines how environmental conditions in the Deschutes watershed affect, the discussion characterizes the environmental conditions within three watershed areas: the Lower Deschutes

2

43 CFR 46.325 - Conclusion of the environmental assessment process.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Conclusion of the environmental assessment process. 46.325 Section...ENVIRONMENTAL POLICY ACT OF 1969 Environmental Assessments § 46.325 Conclusion of the environmental assessment process. Upon review of...

2014-10-01

3

43 CFR 46.325 - Conclusion of the environmental assessment process.  

Code of Federal Regulations, 2013 CFR

...2013-10-01 false Conclusion of the environmental assessment process. 46.325 Section...ENVIRONMENTAL POLICY ACT OF 1969 Environmental Assessments § 46.325 Conclusion of the environmental assessment process. Upon review of...

2013-10-01

4

43 CFR 46.325 - Conclusion of the environmental assessment process.  

Code of Federal Regulations, 2012 CFR

...2011-10-01 true Conclusion of the environmental assessment process. 46.325 Section...ENVIRONMENTAL POLICY ACT OF 1969 Environmental Assessments § 46.325 Conclusion of the environmental assessment process. Upon review of...

2012-10-01

5

43 CFR 46.325 - Conclusion of the environmental assessment process.  

Code of Federal Regulations, 2011 CFR

...2011-10-01 false Conclusion of the environmental assessment process. 46.325 Section...ENVIRONMENTAL POLICY ACT OF 1969 Environmental Assessments § 46.325 Conclusion of the environmental assessment process. Upon review of...

2011-10-01

6

43 CFR 46.325 - Conclusion of the environmental assessment process.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Conclusion of the environmental assessment process. 46.325 Section...ENVIRONMENTAL POLICY ACT OF 1969 Environmental Assessments § 46.325 Conclusion of the environmental assessment process. Upon review of...

2010-10-01

7

Shuttle near-field environmental impacts - Conclusions and observations for launching at other locations  

NASA Technical Reports Server (NTRS)

Near field and far field environmental monitoring activities extending from the first launch of the Space Shuttle at the Kennedy Space Center have provided a database from which conclusions can now be drawn for short term, acute effects of launch and, to a lesser degree, long term cumulative effects on the natural environment. Data for the first 15 launches of the Space Shuttle from Kennedy Space Center Pad 39A are analyzed for statistical significance and reduced to graphical presentations of individual and collective disposition isopleths, summarization of observed environmental impacts (e.g., vegetation damage, fish kills), and supporting data from specialized experiments and laboratory analyses. Conclusions are drawn with regard to the near field environment at Pad A, the effects on the lagoonal complex, and the relationships of these data and conclusions to upcoming operations at Complex 39 Pad B where the environment is significantly different. The paper concludes with a subjective evaluation of the likely impacts at Vandenberg Space Launch Complex 6 for the first Shuttle launch next year.

Koller, A. M., Jr.; Knott, W. M.

1985-01-01

8

Drawing Conclusions  

NSDL National Science Digital Library

Drawing conclusions involves comparing initial ideas with new evidence and then deciding whether the ideas fit or need to be changed. It is the key to the investigation, where mental and practical activity comes together. This is how scientists approach i

Michael P. Klentschy

2008-04-01

9

Environmental conditions and reproductive health outcomes  

EPA Science Inventory

Environmental exposures range across multiple domains to affect human health. In an effort to learn how environmental factors combine to contribute to health outcomes we constructed a multiple environmental domain index (MEDI) for use in health research. We used principal compone...

10

How to change environmental conditions for health.  

PubMed

Since the Lalonde report, contemporary public-health theory has given steadily more attention to the role of environments in influencing health status. Environments, both social and physical, influence health directly or through complex interactions with behavior, genetics and health-care systems. They are also important for public-health because environments are the complex systems through which people are both empowered and exercise their empowerment. If public-health professionals are to play a significant role in influencing environments for health, they need analytical instruments that enable them to link specific environmental conditions with the actions necessary to improve them. These instruments must also enable public-health professionals to identify points of leverage for stimulating key actors to take the actions necessary to make environments more promoting of health. This article first presents one such analytical instrument. Then, building on examples relating to socio-economic health inequities, the analytical instrument is applied to reveal how it can add value to health professionals' effectiveness in planning interventions for more health-promoting environments. PMID:17028104

Commers, Matthew J; Gottlieb, Nell; Kok, Gerjo

2007-03-01

11

Transfert orbital Contr^ole optimal Methodes homotopiques Resultats numeriques Condition du deuxi`eme ordre Conclusion Contr^ole optimal et methodes homotopiques  

E-print Network

Transfert orbital Contr^ole optimal M´ethodes homotopiques R´esultats num´eriques Condition du deuxi`eme ordre Conclusion Contr^ole optimal et m´ethodes homotopiques Universit´e de Gen`eve Joseph Gergaud, Thomas Haberkorn et Pierre Martinon Mercredi 18 octobre 2006 1/ 48 #12;Transfert orbital Contr^ole

Hairer, Ernst

12

Assessing United States hurricane damage under different environmental conditions  

E-print Network

Hurricane activity between 1979 and 2011 was studied to determine damage statistics under different environmental conditions. Hurricanes cause billions of dollars of damage every year in the United States, but damage ...

Maheras, Anastasia Francis

2012-01-01

13

ENVIRONMENTALLY FRIENDLIER ORGANIC TRANSFORMATIONS ON MINERAL SUPPORTS UNDER NONTRADITIONAL CONDITIONS  

EPA Science Inventory

Synthetic organic reactions performed under non-traditional conditions are gaining popularity primarily to circumvent the growing environmental concerns. A solvent-free approach that involves microwave (MW) exposure of neat reactants (undiluted) either in presence of a catalyst o...

14

Lunar Polar Environmental Testing: Regolith Simulant Conditioning  

NASA Technical Reports Server (NTRS)

As ISRU system development approaches flight fidelity, there is a need to test hardware in relevant environments. Extensive laboratory and field testing have involved relevant soil (lunar regolith simulants), but the current design iterations necessitate relevant pressure and temperature conditions. Including significant quantities of lunar regolith simulant in a thermal vacuum chamber poses unique challenges. These include facility operational challenges (dust tolerant hardware) and difficulty maintaining a pre-prepared soil state during pump down (consolidation state, moisture retention).For ISRU purposes, the regolith at the lunar poles will be of most interest due to the elevated water content. To test at polar conditions, the regolith simulant must be doped with water to an appropriate percentage and then chilled to cryogenic temperatures while exposed to vacuum conditions. A 1m tall, 28cm diameter bin of simulant was developed for testing these simulant preparation and drilling operations. The bin itself was wrapped with liquid nitrogen cooling loops (100K) so that the simulant bed reached an average temperature of 140K at vacuum. Post-test sampling was used to determine desiccation of the bed due to vacuum exposure. Depth dependent moisture data is presented from frozen and thawed soil samples.Following simulant only evacuation tests, drill hardware was incorporated into the vacuum chamber to test auguring techniques in the frozen soil at thermal vacuum conditions. The focus of this testing was to produce cuttings piles for a newly developed spectrometer to evaluate. This instrument, which is part of the RESOLVE program science hardware, detects water signatures from surface regolith. The drill performance, behavior of simulant during drilling, and characteristics of the cuttings piles will be offered.

Kleinhenz, Julie

2014-01-01

15

The effects of adverse environmental conditions on workload  

E-print Network

THE EFFECTS OF ADVERSE ENVIRONMENTAL CONDITIONS ON WORKLOAD A Thesis by ANN ELIZABETH MARTIN Submitted to the Graduate College of Texas A8M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE May 1975... Major Subject: Industrial Engineering THE EFFECTS OF ADVERSE ENVIRONMENTAL CONDITIONS ON WORKLOAD A Thesis by ANN ELIZABETH MARTIN Approved as to sty1e and content by: Chairman of Comnsttee Xc' ead of Departme lkI ?r, . ember Me er May 1975...

Martin, Ann Elizabeth

1975-01-01

16

BENTHIC INDEX OF ENVIRONMENTAL CONDITION OF GULF OF MEXICO ESTUARIES  

EPA Science Inventory

An index was developed for estuarine macrobenthos in the Gulf of Mexico that discriminated between areas with degraded environmental conditions and areas with undegraded or reference conditions. est sites were identified as degraded or reference based on criteria for dissolved ox...

17

ENVIRONMENTAL CONDITIONS INFLUENCE ON EMBEDDED CAPACITORS -COMPARISON WITH DISCRETE CAPACITORS  

E-print Network

ENVIRONMENTAL CONDITIONS INFLUENCE ON EMBEDDED CAPACITORS - COMPARISON WITH DISCRETE CAPACITORS Abstract The technology evolution of capacitors from a precedent paper in 1993 [1] in which we studied a ceramic capacitor reported on a FR4 substrate to today's is very important. In order to reduce the risk

Boyer, Edmond

18

Atlantic Skipjack Tuna: Influences of Mean Environmental Conditions on  

E-print Network

Atlantic Skipjack Tuna: Influences of Mean Environmental Conditions on Their Vulnerability to Surface Fishing Gear R. H. EVANS, D. R. McLAIN, and R. A. BAUER Introduction Of those tunas which are exploit- ed commercially in the Atlantic, only the skipjack tuna, Katsuwonus pelamis, appears presently

19

Behavioral and Environmental Conditions associated with Shark Attacks on Humans  

E-print Network

............................................................................................... 25 FIGURE 17. SCATTERPLOT OF GREAT WHITE SHARK LENGTH VS. THE INJURY INFLICTED DURING ATTACK. ............................................................................ 29 #12;v FIGURE 22.GLOBAL DISTRIBUTION OF (A) GREAT WHITE, (B), TIGER, (C) BULL, AND (D) GRAY NURSEBehavioral and Environmental Conditions associated with Shark Attacks on Humans By Joshua J

Worm, Boris

20

The behavior of Kevlar fibers under environmental-stress conditions  

NASA Astrophysics Data System (ADS)

There are a myriad of mechanisms by which polymers can degrade and fail. It is therefore important to understand the physical mechanics, chemistry, their interactions, and kinetics. This pursuit becomes more than just "academic" because these mechanisms might just change with service conditions (i.e. environment and loading). If one does not understand these processes from the molecular to macroscopic scale it would be exceedingly difficult to gain information from accelerated testing because the mechanisms just might change from one condition to another. The purpose of this study was to probe these processes on scales ranging from molecular to macroscopic in environmental stress conditions. This study reports the results of environmental-stress degradation of Kevlar 49 fibers. The environmental agent of focus was the ubiquitous air pollutant complex NOsb{x}. Other materials and environments were investigated to a lesser extent for purposes of comparison. Mechanical property (i.e., short-term strength, modulus, and creep lifetime) degradation was examined using single fiber, yarn, and epoxy coated yarn (composite) specimens under environmental-stress conditions. Optical and scanning electron microscopes were employed to examine and compare the appearance of fracture features resulting from the various testing conditions. Atomic force microscopy augmented these studies with detailed topographical mappings and measures of the fracture surface frictional and modulus properties. Molecular processes (i.e., chain scission and other mechanical-chemical reactions) were probed by measures of changes in viscosity average molecular weight and the infrared spectra. It was demonstrated that environmental-stress degradation effects do occur in the Kevlar-NOsb{x} gas system. Strength decay in environmentally exposed unloaded fibers was demonstrated and a synergistic response in creep reduced fiber lifetimes by three orders of magnitude at moderate loadings. That is to say, the combination of creep load and environment attack was greater than the sum of their individual contributions when measured separately. Microscopy showed a relatively unchanged taxonomy of fracture features over the range of environmental-stress testing conditions employed. Molecular scale probes failed to evidence occurrence of macroscopically homogeneous chain scission, but localized chain scission mechanisms could not be dismissed. The failure mechanism was dominated by fibrillation and plastic slippage on a morphological level. The mechanism of NOx enhanced degradation was postulated as a plasticizing effect in the interfibrillar lower molecular weight phase.

Perry, Mark Charles

21

77 FR 56253 - 60th Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures for...  

Federal Register 2010, 2011, 2012, 2013, 2014

...RTCA Special Committee 135, Environmental Conditions and Test Procedures...RTCA Special Committee 135, Environmental Conditions and Test Procedures...on the rotorcraft DO-160 environmental qualification of equipment Review...

2012-09-12

22

The effect and role of environmental conditions on magnetosome synthesis  

PubMed Central

Magnetotactic bacteria (MTB) are considered the model species for the controlled biomineralization of magnetic Fe oxide (magnetite, Fe3O4) or Fe sulfide (greigite, Fe3S4) nanocrystals in living organisms. In MTB, magnetic minerals form as membrane-bound, single-magnetic domain crystals known as magnetosomes and the synthesis of magnetosomes by MTB is a highly controlled process at the genetic level. Magnetosome crystals reveal highest purity and highest quality magnetic properties and are therefore increasingly sought after as novel nanoparticulate biomaterials for industrial and medical applications. In addition, “magnetofossils,” have been used as both past terrestrial and potential Martian life biosignature. However, until recently, the general belief was that the morphology of mature magnetite crystals formed by MTB was largely unaffected by environmental conditions. Here we review a series of studies that showed how changes in environmental factors such as temperature, pH, external Fe concentration, external magnetic fields, static or dynamic fluid conditions, and nutrient availability or concentrations can all affect the biomineralization of magnetite magnetosomes in MTB. The resulting variations in magnetic nanocrystals characteristics can have consequence both for their commercial value but also for their use as indicators for ancient life. In this paper we will review the recent findings regarding the influence of variable chemical and physical environmental control factors on the synthesis of magnetosome by MTB, and address the role of MTB in the global biogeochemical cycling of iron. PMID:24575087

Moisescu, Cristina; Ardelean, Ioan I.; Benning, Liane G.

2014-01-01

23

CLOUD-TO-GROUND LIGHTNING POLARITY AND ENVIRONMENTAL CONDITIONS OVER THE CENTRAL UNITED STATES  

E-print Network

THESIS CLOUD-TO-GROUND LIGHTNING POLARITY AND ENVIRONMENTAL CONDITIONS OVER THE CENTRAL UNITED SUPERVISION BY CHRISTINA KALB ENTITLED CLOUD-TO-GROUND LIGHTNING POLARITY AND ENVIRONMENTAL CONDITIONS OVER __________________________________________ Richard H. Johnson, Head #12;iii ABSTRACT CLOUD-TO-GROUND LIGHTNING POLARITY AND ENVIRONMENTAL CONDITIONS

Rutledge, Steven

24

The community conditioning hypothesis and its application to environmental toxicology  

SciTech Connect

In this paper the authors present the community conditions hypothesis, ecological communities retain information bout events in their history. This hypothesis, which was derived from the concept of nonequilibrium community ecology, was developed as a framework for understanding the persistence of dose-related responses in multispecies toxicity tests. The authors present data from three standardized aquatic microcosm (SAM) toxicity tests using the water-soluble fractions from turbine fuels (Jet-A, JP-4, and JP-8). In all three tests, the toxicants depressed the Daphnia populations for several weeks, which resulted in algal blooms in the dosed microcosms due to lower predation rates. These effects were short-lived, and by the second and third months of the experiments, the Daphnia populations appeared to have recovered. However, multivariate analysis of the data released dose/response differences that reappeared during the later part of the tests, often due to differences in other consumers (rotifers, ostracods, ciliates), or algae that are not normally consumed (filamentous green algae and bluegreen algae). The findings are consistent with ecological theories that describe communities as the unique production of their etiologies. The implications of this to environmental toxicology are that almost all environmental events leave lasting effects, whether or not they have observed them.

Matthews, R.A.; Landis, W.G.; Matthews, G.B. [Western Washington Univ. Bellingham, WA (United States)

1996-04-01

25

Environmental behavior of profenofos under paddy field conditions.  

PubMed

The environmental behavior of 40% profenofos EC under paddy field conditions was studied. After application of 40% profenofos EC at 900 g a.i./ha level, the initial deposits of profenofos on rice plant, soil and water were found to be 32.700, 0.224 and 3.854 mg/kg respectively. Half-lives (t(1/2)) of profenofos on those substrates were observed to be 5.47, 3.75 and 3.42 days respectively. The residue levels of profenofos on rice straw, soil and rice grain were significantly affected by the dosage and frequency applied. The obtained results might help to recommend the suitable dose and calculate the safety period of profenofos application. PMID:20437027

He, Jiang; Fan, Mingtao; Liu, Xianjin

2010-06-01

26

Pervaporative irrigation: a flow rate driven by environmental conditions  

NASA Astrophysics Data System (ADS)

Pervaporative irrigation allows in-situ treatment of low quality water (e.g. saline water) whilst simultaneously distributing water throughout the soil. The system is also low energy, requiring only that a positive head of water is maintained in a supply tank. To irrigate using this method a pervaporative polymer membrane is formed into a pipe, buried in the soil and filled with water. Water is transported across the membrane by the process of pervaporation whilst the transport of contaminants is retarded, thus reducing the risk of soil degradation due to the use of low water quality. Uniquely these systems also inherently provide a feedback mechanism by which crops can affect the irrigation rate. Such a system has significant possibilities to provide an irrigation pipe from which water is only applied when required, hence reducing the volume of water used. However such systems are currently not fully understood and, to be implemented effectively, the behaviour of the membrane in different environmental conditions must be quantified. From experimental results this work has identified the significance of vapour flows in predicting the flux from the irrigation system in dry soils. In a 15cm layer of sand, the presence of a desiccant above the soil doubled the flux from the pipe, but more than 70% of this mass was adsorbed by the desiccant. Experiments also show that the flux into typical top soil was greater than into sand because of the greater capacity of the top soil for water adsorption. This adsorption maintained a lower humidity in the soil, hence providing a larger gradient across the irrigation membrane and inducing a higher flux. Although there is some evidence that seeds can absorb water from vapour flows the possibility that plants also do this has not yet been explored. This technology provides future opportunities to explore the interaction of plants both with vapour flows, and with a system where the irrigation rate is influenced by the crop uptake and the surrounding environmental conditions.

Todman, L. C.; Mougros, C.; Ireson, A. M.; Butler, A. P.; Templeton, M. R.

2012-04-01

27

CONCLUSIONS, RESEARCH NEEDS, AND RECOMMENDATIONS OF THE EXPERT PANEL: TECHNICAL WORKSHOP ON HUMAN MILK SURVEILLANCE AND RESEARCH FOR ENVIRONMENTAL CHEMICALS IN THE U.S.  

EPA Science Inventory

Proceedings of "The Technical Workshop on Human Milk Surveillance and Research on Environmental Chemicals in the United States" was organized to develop state-of-the-science protocols describing the various aspects of such a program. The 2-day workshop was held at the Mi...

28

Conclusions and recommendations  

NASA Astrophysics Data System (ADS)

Preceding chapters have presented and discussed the objectives related to this large collaborative effort as well as relevant test techniques, modeling details and results in great detail. In 1988 an AGARD report had been published on the results obtained within the Core Program which represents the first of two parts of the AGARD Engine Disc Cooperative Test Program. The major issues treated within the present Supplemental Program were: to expand the initial Ti-6Al-4V data base to other titanium materials such as the Beta-processed IMI 685 and Ti-17 (again load controlled LCF tests were carried out on smooth and notched specimens as well as crack growth tests on compact tension (CT) and corner crack (CC) specimens under constant amplitude loading); to consider variable amplitude and spectrum load sequences that would be typical of compressor disc loading conditions; and to apply and evaluate fatigue crack growth modeling techniques based on the material/load cases of the Cooperative Test Program as mentioned above. Additionally microstructural and fractographic analyses were undertaken in order to relate macro crack growth behavior to microstructural features and intrinsic material properties. In this final chapter, some main aspects and results are summarized. Conclusions and recommendations for future work are given.

Heuler, Paul; Schuetz, Walter; Jany, Eric

1993-04-01

29

Genetic and environmental variation in condition, cutaneous immunity, and haematocrit in house wrens.  

PubMed

BackgroundLife-history studies of wild bird populations often focus on the relationship between an individual¿s condition and its capacity to mount an immune response, as measured by a commonly-employed assay of cutaneous immunity, the PHA skin test. In addition, haematocrit, the packed cell volume in relation to total blood volume, is often measured as an indicator of physiological performance. A multi-year study of a wild population of house wrens has recently revealed that those exhibiting the highest condition and strongest PHA responses as nestlings are most likely to be recruited to the breeding population and to breed through two years of age; in contrast, intermediate haematocrit values result in the highest recruitment to the population. Selection theory would predict, therefore, that most of the underlying genetic variation in these traits should be exhausted resulting in low heritability, although such traits may also exhibit low heritability because of increased residual variance. Here, we examine the genetic and environmental variation in condition, cutaneous immunity, and haematocrit using an animal model based on a pedigree of approximately 2,800 house wrens.ResultsEnvironmental effects played a paramount role in shaping the expression of the fitness-related traits measured in this wild population, but two of them, condition and haematocrit, retained significant heritable variation. Condition was also positively correlated with both the PHA response and haematocrit, but in the absence of any significant genetic correlations, it appears that this covariance arises through parallel effects of the environment acting on this suite of traits.ConclusionsThe maintenance of genetic variation in different measures of condition appears to be a pervasive feature of wild bird populations, in contradiction of conventional selection theory. A major challenge in future studies will be to explain how such variation persists in the face of the directional selection acting on condition in house wrens and other species. PMID:25471117

Sakaluk, Scott K; Wilson, Alastair J; Bowers, E; Johnson, L; Masters, Brian S; Johnson, Bonnie; Vogel, Laura A; Forsman, Anna M; Thompson, Charles F

2014-12-01

30

Impact of Environmental Conditions on the Survival of Cryptosporidium and Giardia on Environmental Surfaces  

PubMed Central

The objective of this study was to find out the impact of environmental conditions on the survival of intestinal parasites on environmental surfaces commonly implicated in the transmission of these parasites. The study was performed by incubating Cryptosporidium and Giardia (oo)cysts on environmentally relevant surfaces such as brushed stainless steel, formica, ceramic, fabric, and skin. Parallel experiments were conducted using clean and soiled coupons incubated under three temperatures. The die-off coefficient rates (K) were calculated using first-order exponential formula. For both parasites, the fastest die-off was recorded on fabric, followed by ceramic, formica, skin, and steel. Die-off rates were directly correlated to the incubation temperatures and surface porosity. The presence of organic matter enhanced the survivability of the resting stages of test parasites. The decay rates calculated in this study can be used in models for public health decision-making process and highlights the mitigation role of hand hygiene agents in their prevention and control. PMID:25045350

Alum, Absar; Absar, Isra M.; Asaad, Hamas; Rubino, Joseph R.; Ijaz, M. Khalid

2014-01-01

31

Surface monitoring measurements of materials on environmental change conditions  

NASA Astrophysics Data System (ADS)

Climate Change is one of the most critical global challenges of our time and the burdened cultural heritage of Europe is particularly vulnerable to be left unprotected. Climate for Culture2 project exploits the damage impact of climate change on cultural heritage at regional scale. In this paper the progress of the study with in situ measurements and investigations at cultural heritage sites throughout Europe combined with laboratory simulations is described. Cultural works of art are susceptible to deterioration with environmental changes causing imperceptibly slow but steady accumulation of damaging effects directly impacted on structural integrity. Laser holographic interference method is employed to provide remote non destructive field-wise detection of the structural differences occurred as climate responses. The first results from climate simulation of South East Europe (Crete) are presented. A full study in regards to the four climate regions of Europe is foreseen to provide values for development of a precise and integrated model of thermographic building simulations for evaluation of impact of climate change. Development of a third generation user interface software optimised portable metrology system (DHSPI II) is designed to record in custom intervals the surface of materials witnessing reactions under simulated climatic conditions both onfield and in laboratory. The climate conditions refer to real data-loggers readings representing characteristic historical building in selected climate zones. New generation impact sensors termed Glass Sensors and Free Water Sensors are employed in the monitoring procedure to cross-correlate climate data with deformation data. In this paper results from the combined methodology are additionally presented.

Tornari, Vivi; Bernikola, Eirini; Bellendorf, Paul; Bertolin, Chiara; Camuffo, Dario; Kotova, Lola; Jacobs, Daniela; Zarnic, Roko; Rajcic, Vlatka; Leissner, Johanna

2013-05-01

32

Clues to Conclusions  

ERIC Educational Resources Information Center

To help students learn how to interpret, infer, and speculate on conclusions, here is a week-long learning activity on "clue finding". A mitten, a bagful of debris and a few intriguing exercises with descriptive paragraphs show students that they use clues every day to draw conclusions and that they can extend this ability to analyze what they…

Soloway, Rhoda K.

1978-01-01

33

Sokolov Effect Conclusions  

E-print Network

Dysprosium Nathan Leefer #12;Background Sokolov Effect Conclusions Outline 1 Background Neutral Hydrogen Stark Effect Hydrogen Atom Interferometer 2 Sokolov Effect Pamir Broken Theories Summary Dysprosium 3 Sokolov Effect Conclusions Pamir Broken Theories Summary Dysprosium Measurement of Lamb Shift Pamir Nathan

Budker, Dmitry

34

Effects of environmental conditions on historical buildings: lichens and NOx gases  

Microsoft Academic Search

Environmental conditions affect human life in various ways. One of the domains of environmental conditions is buildings, and\\u000a amongst them, a major and important group is the historical buildings. To keep this inheritance alive, one needs to determine\\u000a the effects of environmental conditions. In this work, effects of lichens and NOx on 7 historical buildings in Erzurum were\\u000a investigated. Historical

Arzu Cicek; Ali Aslan; Kenan Yaz?c?; Ali Savas Koparal

2009-01-01

35

Prediction of glass durability as a function of environmental conditions  

SciTech Connect

A thermodynamic model of glass durability is applied to natural, ancient, and nuclear waste glasses. The durabilities of over 150 different natural and man-made glasses, including actual ancient Roman and Islamic glasses (Jalame ca. 350 AD, Nishapur 10-11th century AD and Gorgon 9-11th century AD), are compared. Glass durability is a function of the thermodynamic hydration free energy, ..delta..G/sub hyd/, which can be calculated from glass composition and solution pH. The durability of the most durable nuclear waste glasses examined was /approximately/10/sup 6/ years. The least durable waste glass formulations were comparable in durability to the most durable simulated medieval window glasses of /approximately/10/sup 3/ years. In this manner, the durability of nuclear waste glasses has been interpolated to be /approximately/10/sup 6/ years and no less than 10/sup 3/ years. Hydration thermodynamics have been shown to be applicable to the dissolution of glass in various natural environments. Groundwater-glass interactions relative to geologic disposal of nuclear waste, hydration rind dating of obsidians, andor other archeological studies can be modeled, e.g., the relative durabilities of six simulated medieval window glasses have been correctly predicted for both laboratory (one month) and burial (5 years) experiments. Effects of solution pH on glass dissolution has been determined experimentally for the 150 different glasses and can be predicted theoretically by hydration thermodynamics. The effects of solution redox on dissolution of glass matrix elements such as SI and B have shown to be minimal. The combined effects of solution pH and Eh have been described and unified by construction of thermodynamically calculated Pourbaix (pH-Eh) diagrams for glass dissolution. The Pourbaix diagrams have been quantified to describe glass dissolution as a function of environmental conditions by use of the data derived from hydration thermodynamics. 56 refs., 7 figs.

Jantzen, C.M.

1988-01-01

36

Effects of Environmental Conditions on an Urban Wetland's Methane Fluxes  

NASA Astrophysics Data System (ADS)

Methane emissions from wetlands are the largest natural source of uncertainty in the global methane (CH4) budget. Wetlands are highly productive ecosystems with a large carbon sequestration potential. While wetlands are a net sink for carbon dioxide, they also release methane, a potent greenhouse gas. To effectively develop wetland management techniques, it is important to properly calculate the carbon budget of wetlands by understand the driving factors of methane fluxes. We constructed an eddy flux covariance system in the Olentangy River Wetland Research Park, a series of created and restored wetland in Columbus Ohio. Through the use of high frequency open path infrared gas analyzer (IRGA) sensors, we have continuously monitored the methane fluxes associated with the wetland since May 2011. To account for the heterogeneous landscape surrounding the tower, a footprint analysis was used to isolate data originating from within the wetland. Continuous measurements of the meteorological and environmental conditions at the wetlands coinciding with the flux measurements allow the interactions between methane fluxes and the climate and ecological forcing to be studied. The wintertime daily cycle of methane peaks around midday indicating a typical diurnal pattern in cold months. In the summer, the peak shifts to earlier in the day and also includes a daily peak occurring at approximately 10 AM. We believe this peak is associated with the onset of photosynthesis in Typha latifolia flushing methane from the plant's air filled tissue. Correlations with methane fluxes include latent heat flux, soil temperature, and incoming radiation. The connection to radiation may be further evidence of plant activity as a driver of methane fluxes. Higher methane fluxes corresponding with higher soil temperature indicates that warmer days stimulate the methanogenic consortium. Further analysis will focus on separating the methane fluxes into emissions from different terrain types within the wetland.

Naor Azrieli, L.; Morin, T. H.; Bohrer, G.; Schafer, K. V.; Brooker, M.; Mitsch, W. J.

2013-12-01

37

Thermal acclimation of photosynthesis and respiration in Pinus radiata and Populus deltoides to changing environmental conditions.  

E-print Network

??Although it has long been recognized that physiological acclimation of photosynthesis and respiration can occur in plants exposed to changing environmental conditions (e.g. light, temperature… (more)

Ow, Lai Fern

2008-01-01

38

EVALUATION OF GEOMEMBRANE SEAMS EXPOSED TO SELECTED ENVIRONMENTAL CONDITIONS  

EPA Science Inventory

The integrity of a geomembrane installation is no better than its seaming system. In an attempt to learn more about the strength and durability of presently available seaming systems, the Municipal Environmental Research Laboratory of the United States Environmental Protection Ag...

39

[Social conditions of the exposure to environmental lead observed in children from Piekary Slaskie].  

PubMed

The aim of the paper was to evaluate the social conditions of the exposure to environmental lead observed in children from Piekary Slaskie, the patients of The Environmental Health Outpatient Department. The examinations were conducted in 1995, in 183 children: 95 (52%) girls and 88 (48%) boys, which is 5.3% of the total population of children aged 3-12 living in the districts of Piekary Slaskie with the higher risk of lead intoxication: Brzeziny Slaskie, Dabrówka Wielka and Brzozowice-Kamie?. The examinations were conducted in the period of April and May. They comprised the following parameters: environmental and paediatric interview, physical examination--evaluation of total condition of the child, and laboratory determination of lead concentration in blood with the method of atomic flameless spectrophotometry. The collected data was statistically elaborated with the use of the "STATISTICA 5.1 PL" programme in the Computer Laboratory at the Silesian Engineering College in Katowice. In 1995 the average lead concentration in blood of 183 children from Piekary Slaskie aged 3-12 ranged from 2.2 to 39.6 microg/dl, and the average population concentration was of 8.22 microg/dl SD: 4.7 microg/dl. Significantly higher average lead concentration in blood was observed in nursery children aged 3-4 (9.56 microg/dl SD: 4.2 microg/dl) when compared to school children (7.4 microg/dl SD: 3.8 microg/dl). In the examined population 19.8% of children crossed the level of 10.0 microg/dl. The conclusions of the examinations may be as follows: bad social-economic conditions (especially unemployment and pathology of families), hygienic customs and nutrition habits of the native population of Piekary Slaskie as well as only the primary or professional education of parents influence the rise in average lead concentration in blood at nursery and school children. PMID:15682943

Szymik, Ewa

2004-01-01

40

Pyrite Flotation With Xanthate Under Alkaline Conditions --Application to Environmental Desulfurisation  

E-print Network

Pyrite Flotation With Xanthate Under Alkaline Conditions -- Application to Environmental,3 and M Aubertin4 ABSTRACT The extensive literature on sulfide flotation indicates that pyrite poorly floats under alkaline condition. Xanthate concentration has a positive effect on pyrite flotation

Aubertin, Michel

41

Assessing the Relationship between Socioeconomic Conditions and Urban Environmental Quality in Accra, Ghana  

PubMed Central

The influence of socioeconomic status (SES) on health inequalities is widely known, but there is still poor understanding of the precise relationship between area-based socioeconomic conditions and neighborhood environmental quality. This study aimed to investigate the socioeconomic conditions which predict urban neighbourhood environmental quality. The results showed wide variation in levels of association between the socioeconomic variables and environmental conditions, with strong evidence of a real difference in environmental quality across the five socioeconomic classes with respect to total waste generation (p < 0.001), waste collection rate (p < 0.001), sewer disposal rate (p < 0.001), non-sewer disposal (p < 0.003), the proportion of households using public toilets (p = 0.005). Socioeconomic conditions are therefore important drivers of change in environmental quality and urban environmental interventions aimed at infectious disease prevention and control if they should be effective could benefit from simultaneous implementation with other social interventions. PMID:20195437

Fobil, Julius; May, Juergen; Kraemer, Alexander

2010-01-01

42

ForEnvironmentalManagementofMilitaryLands Land Condition-Trend Analysis  

E-print Network

THECENTER ForEnvironmentalManagementofMilitaryLands Land Condition-Trend Analysis (LCTA) II Survey Using MS Access to Analyze Land Condition-Trend Analysis Data A Beginner's Guide By Christine Bern CENTER FOR ENVIRONMENTAL MANAGEMENT OF MILITARY LANDS Colorado State University Fort Collins, Colorado

43

EFFECT OF ENVIRONMENTAL CONDITIONS ON PRODUCTIVE AND PHYSIOLOGICAL RESPONSES IN GROWING RABBITS  

Microsoft Academic Search

Environmental conditions are important for the welf are of intensively-reared rabbits. The presence inside the cage of a piece of wood represents a for m of environmental enrichment, but also an alternative type of feeding. A trial was carried ou t to study the effect of lighting and type of feedi ng on the productive performance, bone conditions and pla

44

Perceiving environmental properties from motion information: Minimal conditions  

NASA Technical Reports Server (NTRS)

The status of motion as a minimal information source for perceiving the environmental properties of surface segregation, three-dimensional (3-D) form, displacement, and dynamics is discussed. The selection of these particular properties was motivated by a desire to present research on perceiving properties that span the range of dimensional complexity.

Proffitt, Dennis R.; Kaiser, Mary K.

1989-01-01

45

Conclusions: Anticipation and Action  

NASA Astrophysics Data System (ADS)

International interventions are potentially massive undertakings intended to create a variety of desirable conditions on the ground - political, security, economic, social, etc. - in order to bring lasting peace and stability. Such endeavors are ­multifaceted in nature, and making progress is invariably an uncertain and vexing process. Clearly, no book can fully address this vast topic.

Kott, Alexander; Morse, Stephen

46

Project 198740100 Assessment of Smolt Condition: Biological and Environmental Interactions  

E-print Network

1997 that have led to the current objectives. Emphasis 1997 1998 1999 2000 2001 2002 Smolt Condition-river survival/estuary * * * * * temperature * * precocity/residualism--control by growth and temperature, higher at production facilities ­ density, temperature, flow, water quality, feed enhancement, release condition

47

Environmental stress cracking of plastics under dynamic conditions  

E-print Network

pose, like ease of processability, high strength-to- weight ratio, low raw material costs, and low manufacturing expenses, to name a few. Since, polymers are relatively new materials, their behavior in various aspects has not been fully understood.... Like most other materials, polymers also experience adverse environmental effects on fracture. Yet nowhere is the influence of the environment on fracture as important or widespread as it is in the polymeric materials [1]. It has been a failure...

Suresh, Mitta

2012-06-07

48

AGE AND ENVIRONMENTAL CONDITIONS AFFECT RECRUITMENT IN GREATER SNOW GEESE  

Microsoft Academic Search

Recruitment is an important determinant of fitness and population growth rates, but few studies have examined the effect of environmental stochasticity on this life history trait. Furthermore, most studies have been unable to separate the influence of juvenile survival and age-specific breeding proportions on recruitment. We used a recently developed approach, based on capture-mark-recapture methods, in which local recruitment is

Eric T. Reed; Gilles Gauthier; Roger Pradel; Jean-Dominique Lebreton

2003-01-01

49

Common lung conditions: environmental pollutants and lung disease.  

PubMed

Exposure to environmental pollutants can have short- and long-term effects on lung health. Sources of air pollution include gases (eg, carbon monoxide, ozone) and particulate matter (eg, soot, dust). In the United States, the Environmental Protection Agency regulates air pollution. Elevated ozone concentrations are associated with increases in lung-related hospitalizations and mortality. Elevated particulate matter pollution increases the risk of cardiopulmonary and lung cancer mortality. Occupations with high exposures to pollutants (eg, heavy construction work, truck driving, auto mechanics) pose higher risk of chronic obstructive lung disease. Some industrial settings (eg, agriculture, sawmills, meat packing plants) also are associated with higher risks from pollutants. The Environmental Protection Agency issues an air quality index for cities and regions in the United States. The upper levels on the index are associated with increases in asthma-related emergency department visits and hospitalizations. Damp and moldy housing might make asthma symptoms worse; individuals from lower socioeconomic groups who live in lower quality housing are particularly at risk. Other household exposures that can have negative effects on lung health include radon, nanoparticles, and biomass fuels. PMID:23767420

Delzell, John E

2013-06-01

50

Properties of Bacillus anthracis spores prepared under various environmental conditions  

Microsoft Academic Search

Bacillus anthracis makes highly stable, heat-resistant spores which remain viable for decades. Effect of various stress conditions on sporulation\\u000a in B. anthracis was studied in nutrient-deprived and sporulation medium adjusted to various pH and temperatures. The results revealed that\\u000a sporulation efficiency was dependent on conditions prevailing during sporulation. Sporulation occurred earlier in culture\\u000a sporulating at alkaline pH or in PBS

Renu B. Baweja; Mohd S. Zaman; Abid R. Mattoo; Kirti Sharma; Vishwas Tripathi; Anita Aggarwal; Gyanendra P. Dubey; Raj K. Kurupati; Munia Ganguli; N. K. Chaudhury; Somdutta Sen; Taposh K. Das; Wasudev N. Gade; Yogendra Singh

2008-01-01

51

Alternative splicing and nonsense-mediated decay of circadian clock genes under environmental stress conditions in Arabidopsis  

PubMed Central

Background The circadian clock enables living organisms to anticipate recurring daily and seasonal fluctuations in their growth habitats and synchronize their biology to the environmental cycle. The plant circadian clock consists of multiple transcription-translation feedback loops that are entrained by environmental signals, such as light and temperature. In recent years, alternative splicing emerges as an important molecular mechanism that modulates the clock function in plants. Several clock genes are known to undergo alternative splicing in response to changes in environmental conditions, suggesting that the clock function is intimately associated with environmental responses via the alternative splicing of the clock genes. However, the alternative splicing events of the clock genes have not been studied at the molecular level. Results We systematically examined whether major clock genes undergo alternative splicing under various environmental conditions in Arabidopsis. We also investigated the fates of the RNA splice variants of the clock genes. It was found that the clock genes, including EARLY FLOWERING 3 (ELF3) and ZEITLUPE (ZTL) that have not been studied in terms of alternative splicing, undergo extensive alternative splicing through diverse modes of splicing events, such as intron retention, exon skipping, and selection of alternative 5? splice site. Their alternative splicing patterns were differentially influenced by changes in photoperiod, temperature extremes, and salt stress. Notably, the RNA splice variants of TIMING OF CAB EXPRESSION 1 (TOC1) and ELF3 were degraded through the nonsense-mediated decay (NMD) pathway, whereas those of other clock genes were insensitive to NMD. Conclusion Taken together, our observations demonstrate that the major clock genes examined undergo extensive alternative splicing under various environmental conditions, suggesting that alternative splicing is a molecular scheme that underlies the linkage between the clock and environmental stress adaptation in plants. It is also envisioned that alternative splicing of the clock genes plays more complex roles than previously expected. PMID:24885185

2014-01-01

52

Conclusions and Recommendations. Chapter 37  

NASA Technical Reports Server (NTRS)

This chapter provides a brief wrap-up of the task group report and focuses on the overall conclusions and recommendations for future work for the CAWAPI and VFE-2 facets beyond the task group. The overall conclusion is that the Technology Readiness Level (TRL) of CFD solvers has been improved in predicting the flow-physics of vortex-dominated flows during the work of the task group, by having flight and wind-tunnel data available for comparison. Moreover, like all good scientific studies, this task group has identified flight conditions on the F-16XL airplane or wind-tunnel test conditions for a specific leading-edge radius on the 65 delta-wing model where the TRL still needs to be increased.

Lamar, John E.; Hummel, Dietrich

2009-01-01

53

Conclusions and Policy Directions,  

SciTech Connect

This chapter briefly revisits the constraints and opportunities of mitigation and adaptation, and highlights and the multiple linkages, synergies and trade-offs between mitigation, adaptation and urban development. The chapter then presents future policy directions, focusing on local, national and international principles and policies for supporting and enhancing urban responses to climate change. In summary, policy directions for linking climate change responses with urban development offer abundant opportunities; but they call for new philosophies about how to think about the future and how to connect different roles of different levels of government and different parts of the urban community. In many cases, this implies changes in how urban areas operate - fostering closer coordination between local governments and local economic institutions, and building new connections between central power structures and parts of the population who have often been kept outside of the circle of consultation and discourse. The difficulties involved in changing deeply set patterns of interaction and decision-making in urban areas should not be underestimated. Because it is so difficult, successful experiences need to be identified, described and widely publicized as models for others. However, where this challenge is met, it is likely not only to increase opportunities and reduce threats to urban development in profoundly important ways, but to make the urban area a more effective socio-political entity, in general - a better city in how it works day to day and how it solves a myriad of problems as they emerge - far beyond climate change connections alone. It is in this sense that climate change responses can be catalysts for socially inclusive, economically productive and environmentally friendly urban development, helping to pioneer new patterns of stakeholder communication and participation.

Wilbanks, Thomas J [ORNL; Romero-Lankao, Paty [National Center for Atmospheric Research (NCAR); Gnatz, P [National Center for Atmospheric Research (NCAR)

2011-01-01

54

Environmental qualification tests, signal conditioning unit, SD802 materials experiment  

Microsoft Academic Search

The vibration qualification test described within this report completes the vibration qualification requirements as established by the LDEF Project Office for flight hardware association with the SD802 materials experiment. The combined environment temperature altitude test described was completed to establish the operating stability of electronic components within the signal conditioning electronic units (SCUs).

A. F. Digiacomo; W. C. Burns; P. Schall

1983-01-01

55

EFFECTS OF ENVIRONMENTAL CONDITIONS ON ISOPRENE EMISSION FROM LIVE OAK  

EPA Science Inventory

Live-oak plants (Quercus virginia) were subjected to various levels of CO2, water stress or photosynthetic photon flux density to test the hypothesis that isoprene biosynthesis occurred only under conditions of restricted CO2 availability. Isoprene emission increases as the ambie...

56

Neglected Buildings, Damaged Health: A "Snapshot" of New York City Public School Environmental Conditions.  

ERIC Educational Resources Information Center

Survey results are presented from 65 parents, students over 12 years, teachers, and other school employees using 39 different schools about environmental conditions in New York City public schools. It shows the results of years of neglect of infrastructure for children and reveals disturbing new information about the environmental health of school…

Advocates for Children of New York, Inc., Long Island City.

57

Environmental Conditions in Northern Gulf of Mexico Estuaries: Before and After the Deepwater Horizon Oil Spill  

EPA Science Inventory

When conducting an environmental assessment to determine the ecological effects of the Deepwater Horizon (DWH) Oil Spill in the Gulf of Mexico (GOM), baseline environmental data is essential to establish ecosystem condition prior to the incident. EPA?s National Coastal Assessment...

58

Temperature-based death time estimation with only partially known environmental conditions  

Microsoft Academic Search

The temperature-oriented death time determination is based on mathematical model curves of postmortem rectal cooling. All mathematical models require knowledge of the environmental conditions. In medico-legal practice homicide is sometimes not immediately suspected at the death scene but afterwards during external examination of the body. The environmental temperature at the death scene remains unknown or can only be roughly reconstructed.

Gita Mall; Mona Eckl; Inga Sinicina; Oliver Peschel; Michael Hubig

2005-01-01

59

Using a Physical Education Environmental Survey to Identify Areas of Concern and Improve Conditions  

ERIC Educational Resources Information Center

School environmental conditions can impact learning in physical educational classes. It is important for schools to control environmental health hazards, not only to promote a conducive school learning environment, but to also reduce associated health risks. To help physical education leaders determine the quality of physical education facilities…

Hill, Grant; Hulbert, George

2007-01-01

60

Scratch Behavior of Multiphase Styrenic Copolymers and Effects of Environmental Conditioning  

E-print Network

and type, environmental conditioning through heat processing, moisture exposure, and water immersion. A standardized progressive load scratch test (ASTM D7027/ISO 19252) is used to examine the mechanical response to scratch deformation in ASA and ABS...

Moghbelli, Ehsan

2014-09-05

61

76 FR 22161 - Fifty Seventh Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Approval of Summary from Fifty-Sixth Meeting (RTCA Paper No. 224-110/SC 135-683). Review Approved Revised SC135 TOR (Terms of Reference)-- Environmental Conditions and Test Procedures for Airborne Equipment-- (RTCA Paper No....

2011-04-20

62

76 FR 59481 - Fifty Eighth Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Approval of Summary from Fifty-Seventh Meeting (RTCA Paper No. 166-11/SC 135-685). Review Approved Revised SC135 TOR (Terms of Reference)-- Environmental Conditions and Test Procedures for Airborne Equipment-- (RTCA Paper No....

2011-09-26

63

ENVIRONMENTALLY FRIENDLIER ORGANIC TRANSFORMATIONS ON MINERAL SUPPORTS UNDER NON-TRADITIONAL CONDITIONS  

EPA Science Inventory

Synthetic organic reactions performed under non-traditional conditions are gaining popularity primarily to circumvent the growing environmental concerns. A solvent-free approach that involves microwave (MW) exposure of neat reactants (undiluted) either in presence of a catalyst o...

64

Prebiotic cell membranes that survive extreme environmental pressure conditions.  

PubMed

Attractive candidates for compartmentalizing prebiotic cells are membranes comprised of single-chain fatty acids. It is generally believed that life may have originated in the depth of the protoocean, that is, under high hydrostatic pressure conditions, but the structure and physical-chemical properties of prebiotic membranes under such conditions have not yet been explored. We report the temperature- and pressure-dependent properties of membranes composed of prebiotically highly-plausible lipids and demonstrate that prebiotic membranes could not only withstand extreme temperatures, but also serve as robust models of protocells operating in extreme pressure environments. We show that pressure not only increases the stability of vesicular systems but also limits their flexibility and permeability to solutes, while still keeping the membrane in an overall fluid-like and thus functional state. PMID:24953643

Kapoor, Shobhna; Berghaus, Melanie; Suladze, Saba; Prumbaum, Daniel; Grobelny, Sebastian; Degen, Patrick; Raunser, Stefan; Winter, Roland

2014-08-01

65

Biofilm Formation by Cryptococcus neoformans Under Distinct Environmental Conditions  

PubMed Central

Cryptococcus neoformans is an opportunistic fungal pathogen with a propensity to infect the central nervous system of immune compromised individuals causing life-threatening meningoencephalitis. Cryptococcal biofilms have been described as a protective niche against microbial predators in nature and shown to enhance resistance against antifungal agents and specific mediators of host immune responses. Based on the potential importance of cryptococcal biofilms to its survival in the human host and in nature, these studies were designed to investigate those factors that mediate biofilm formation by C. neoformans. We observed that C. neoformans preferentially grew as planktonic cells when cultured under specific conditions designed to mimic growth within host tissues (37°C, neutral pH, and ~5% CO2) or phagocytes (37°C, acidic pH, and ~5% CO2) and as biofilms when cultured under conditions such as those encountered in the external environment (25–37°C, neutral pH, and ambient CO2). Altogether, our studies suggest that conditions similar to those observed in its natural habitat may be conducive to biofilm formation by C. neoformans. PMID:19130292

Ravi, Sailatha; Pierce, Christopher; Witt, Colleen; Wormley, Floyd L.

2014-01-01

66

Fermentation patterns of forage sorghum ensiled under different environmental conditions.  

PubMed

The effects of temperature, aerobic and anaerobic conditions in the silo and plant characteristics [water-soluble carbohydrate (WSC) contents, growing season] on the fermentation characteristics of a tropical forage species, Sorghum bicolor cv. sugar-drip, were investigated. Silages fermented in oxygen-impermeable bags were well preserved and had low pH (3.7), high lactic acid [72 g kg(-1) dry matter (DM) ? 80% of total acids], and low butyric acid (0.12 g kg(-1) DM) and ammonia nitrogen (NH3-N) (57 g kg(-1) total nitrogen contents. Conversely, the use of oxygen-permeable bags as silos allowed aerobic decomposition of the ensiled forages. Increasing the incubation temperature lowered the population of lactic acid bacteria, reduced lactic acid production and caused the pH to rise. The heterofermentative Leuconostoc spp. predominated on fresh forages but homofermentative Lactobacillus plantarum began to dominate after 5 and 8 days of fermentation. Heterofermentative lactobacilli, notably Lactobacillus brevis, were dominant among the isolates obtained from 100-day silages. Varying the WSC contents, by crushing and/or chopping the forage, and growing season did not significantly affect the fermentation quality of the resulting silages. It was concluded that the maintenance of anaerobic conditions is essential if good quality silage is to be produced from tropical forage species. PMID:24424934

Tjandraatmadja, M; Norton, B W; Macrae, I C

1991-03-01

67

Rift Valley Fever Outbreaks in Mauritania and Related Environmental Conditions  

PubMed Central

Four large outbreaks of Rift Valley Fever (RVF) occurred in Mauritania in 1998, 2003, 2010 and 2012 which caused lots of animal and several human deaths. We investigated rainfall and vegetation conditions that might have impacted on RVF transmission over the affected regions. Our results corroborate that RVF transmission generally occurs during the months of September and October in Mauritania, similarly to Senegal. The four outbreaks were preceded by a rainless period lasting at least a week followed by heavy precipitation that took place during the second half of the rainy season. First human infections were generally reported three to five weeks later. By bridging the gap between meteorological forecasting centers and veterinary services, an early warning system might be developed in Senegal and Mauritania to warn decision makers and health services about the upcoming RVF risk. PMID:24413703

Caminade, Cyril; Ndione, Jacques A.; Diallo, Mawlouth; MacLeod, Dave A.; Faye, Ousmane; Ba, Yamar; Dia, Ibrahima; Morse, Andrew P.

2014-01-01

68

Are spatial variations in the diets of hydrothermal fauna linked to local environmental conditions?  

E-print Network

, offering limited food sources to deep-sea organisms (Suess, 1980). At hydrothermal vents, microbialAre spatial variations in the diets of hydrothermal fauna linked to local environmental conditions conditions Hydrothermal springs Food webs Mid-Atlantic Ridge Lucky Strike (37117.290 N 32116.450 W) a b s t r

Long, Bernard

69

Modelling of internal environmental conditions in a full-scale commercial pig house containing animals  

Microsoft Academic Search

In large livestock houses, controlling the internal environmental condition is a key factor for enhancing livestock productivity.The basis of thermal comfort, contaminants, and ventilation efficiency is the internal air flow, which can be controlled by the ventilation system. Field experimentation is a challenging method for analysing air flows due to limited number of measurement points, cost, unstable weather conditions, and

I.-H. Seo; I.-B. Lee; O.-K. Moon; S.-W. Hong; H.-S. Hwang; J. P. Bitog; K.-S. Kwon; Z. Ye; J.-W. Lee

70

Quantifying diminution in value due to detrimental conditions: An application to environmentally contaminated properties  

Microsoft Academic Search

Quantifying damages in a case involving diminution in value is an involved process, particularly when environmentally contaminated properties are involved. This article reviews the standard categories of detrimental conditions and the various fundamental issues that must be addressed in any assignment involving detrimental conditions. Next, the basic components of measuring diminution in value are introduced in formula form, along with

Randall Bell

1996-01-01

71

Effect of environmental conditions on the properties of fresh and hardened concrete  

Microsoft Academic Search

The effect of varying environmental conditions, at the time of casting on the properties of fresh and hardened concrete was evaluated. The influence of air temperature, wind velocity, and relative humidity on plastic shrinkage, compressive strength, pulse velocity and pore structure of concrete was investigated. Results indicate that exposure conditions at the time of casting significantly affect plastic shrinkage of

Abdullah A Almusallam

2001-01-01

72

Effects of Environmental and Social Conditions on Homosexual Pairing in the Japanese Beetle (Popillia japonica Newman)  

Microsoft Academic Search

Homosexual pairing between males occurs under natural conditions in a wide variety of taxa, including many insect species, but few studies have investigated how environmental and social conditions affect same-sex pairing in insects. We investigated factors affecting homosexual pairing in male Japanese beetles (Popillia japonica Newman) in the field and in the laboratory. Specifically, we investigated how time of day,

Paul V. Switzer; Patrick S. Forsythe; Kara Escajeda; Kipp C. Kruse

2004-01-01

73

Conclusion  

NASA Technical Reports Server (NTRS)

This compilation of papers in this book represents approximately half of the works discussed at the MS&T 2010 symposium entitled Tools, Models, Databases, and Simulation Tools Developed and Needed to Realize the Vision of Integrated Computational Materials Engineering at Materials Science & Technology wherein five sessions comprised of 33 presentations was organized. The goal of the symposium was two fold To provide a forum in which current state-of-the-art methods for ICME (e.g., information informatics, experimentation, and modeling) could be openly discussed and critiqued by not only materials scientist but also structural engineers/researchers, component designers, industrial leaders and government program managers. To leave the symposium and in particular the panel discussion with a clear idea of the gaps and barriers (both technical, cultural and economical) that must be addressed in order for ICME to fully succeed. The organizers felt that these goals were met, as particularly evident by the standing room only attendance during a lively panel discussion session at the end of the Symposium. However it is the firm belief of the editors of this book that this symposium was merely a start in the right direction, and that subsequent conferences/symposium (e.g., First World Congress on Integrated Computational Materials Engineering to be held July 10-14, 2011 at Seven Springs Mountain Resort in Pennsylvania) must work hard to ensure that a truly diverse, multidisciplinary, community of researchers and practitioners are present and have ample opportunity for interaction. This will ensure that a proper balance between push and pull disciplines and technologies is maintained so that this emerging focus area, Integrated Computational Materials Engineering (ICME), has the greatest potential for success and impact on "system-level" payoffs. Similarly, a pro-active approach is required to reform historical modes of operation in industry, government and the academic sectors so as to facilitate multidisciplinary collaboration and to clearly articulate the vision and scope of ICME.

Arnold, Steven M.; Wong, Terry T.

2011-01-01

74

Conclusions  

NASA Astrophysics Data System (ADS)

Some say that an increase in security does not necessarily mean a further encroachment on privacy - indeed, security is necessary to protect personal data and our privacy. Networks must be secure, our personal devices, reliable, dependable and trustworthy. But security is a multifaceted term, with many dimensions. We are of the view that an increase in security most likely will encroach upon our privacy in an ambient intelligence world. Surveillance cameras will continue to proliferate. We assume that, whatever the law is, whatever privacy protections government and business say they honour, our telecommunications, e-mails and Internet usage will be monitored to an increasing degree. The same will be true of our interfaces with the world of ambient intelligence.

Ahonen, Pasi; Alahuhta, Petteri; Daskala, Barbara; Delaitre, Sabine; Hert, Paul De; Lindner, Ralf; Maghiros, Ioannis; Moscibroda, Anna; Schreurs, Wim; Verlinden, Michiel

75

Conclusion  

NASA Astrophysics Data System (ADS)

It is often held that things should always be made simple, which presumes that either that they can always be made simple or that all the jetisoned logic doesn't matter anyway. Alledgedly, anything should be explainable so that anyone can understand it. Don't get bogged down in dreary details. It should be effortless for the reader: low-dimensional systems exhibit complex behaviour while high-dimensional systems exhibit simple behaviour (to return to our prolegomonal opening), competition is a universal solution, demand must increase as price falls, and everything under the sun neatly fits a power law. Or so the story goes...

Ivancevic, Vladimir G.; Reid, Darryn J.

2015-11-01

76

Parasitism in early life: environmental conditions shape within-brood variation in responses to infection  

PubMed Central

Parasites play key ecological and evolutionary roles through the costs they impose on their host. In wild populations, the effect of parasitism is likely to vary considerably with environmental conditions, which may affect the availability of resources to hosts for defense. However, the interaction between parasitism and prevailing conditions is rarely quantified. In addition to environmental variation acting on hosts, individuals are likely to vary in their response to parasitism, and the combined effect of both may increase heterogeneity in host responses. Offspring hierarchies, established by parents in response to uncertain rearing conditions, may be an important source of variation between individuals. Here, we use experimental antiparasite treatment across 5 years of variable conditions to test how annual population productivity (a proxy for environmental conditions) and parasitism interact to affect growth and survival of different brood members in juvenile European shags (Phalacrocorax aristotelis). In control broods, last-hatched chicks had more plastic growth rates, growing faster in more productive years. Older siblings grew at a similar rate in all years. Treatment removed the effect of environment on last-hatched chicks, such that all siblings in treated broods grew at a similar rate across environmental conditions. There were no differences in nematode burden between years or siblings, suggesting that variation in responses arose from intrinsic differences between chicks. Whole-brood growth rate was not affected by treatment, indicating that within-brood differences were driven by a change in resource allocation between siblings rather than a change in overall parental provisioning. We show that gastrointestinal parasites can be a key component of offspring's developmental environment. Our results also demonstrate the value of considering prevailing conditions for our understanding of parasite effects on host life-history traits. Establishing how environmental conditions shape responses to parasitism is important as environmental variability is predicted to increase.

Granroth-Wilding, Hanna M V; Burthe, Sarah J; Lewis, Sue; Reed, Thomas E; Herborn, Katherine A; Newell, Mark A; Takahashi, Emi A; Daunt, Francis; Cunningham, Emma J A

2014-01-01

77

Characterizing the environmental conditions and estimating aboveground biomass productivity for switchgrass in the Great Plains, USA  

NASA Astrophysics Data System (ADS)

Switchgrass is being evaluated as a potential feedstock source for cellulosic biofuels and is being cultivated in several regions of the United States. The recent availability of switchgrass land cover maps derived from the National Agricultural Statistics Service cropland data layer for the conterminous United States provides an opportunity to assess the environmental conditions of switchgrass over large areas and across different geographic locations. The main goal of this study is to investigate the relationship between site environmental conditions and switchgrass productivity and identify the optimal conditions for productive switchgrass in the Great Plains (GP). Environmental and climate variables such as elevation, soil organic carbon, available water capacity, climate, and seasonal weather were used in this study. Satellite-derived growing season averaged Normalized Difference Vegetation Index was used as a proxy for switchgrass productivity. The environmental conditions for switchgrass sites of variable productivity were summarized and a data-driven multiple regression switchgrass productivity model was developed. Results show that spring precipitation has the strongest correlation with switchgrass productivity (r = 0.92, 176 samples) and spring minimum temperature has the weakest correlation with switchgrass productivity (r = 0.16). An estimated switchgrass productivity map for the entire GP based on site environmental and climate conditions was generated. The estimated switchgrass biomass productivity map indicates that highly productive switchgrass areas are mainly located in the eastern part of the GP. Results from this study provide useful information for assessing economic feasibility or optimal land use decisions regarding switchgrass development in the GP.

Gu, Y.; Wylie, B. K.; Howard, D. M.

2013-12-01

78

A benthic index of environmental condition of Gulf of Mexico estuaries  

Microsoft Academic Search

An index was developed for estuarine macrobenthos in the Gulf of Mexico that discriminated between areas with degraded environmental\\u000a conditions and areas with undegraded or reference conditions. Test sites were identified as degraded or reference based on\\u000a criteria for dissolved oxygen levels, sediment toxicity tests, and sediment contamination. Discriminant analysis was used\\u000a to identify a suite of measures of benthic

Virginia D. Engle; J. Kevin Summers; Gary R. Gaston

1994-01-01

79

Environmental heterogeneity influences the reliability of secondary sexual traits as condition indicators.  

PubMed

Numerous studies have shown positive associations between ornaments and condition, as predicted by indicator models of sexual selection. However, this idea is continuously challenged by opposite results, which reveal our lack of full understanding of how sexual selection works. Environmental heterogeneity may explain such inconsistencies, but valid field tests of this idea are currently lacking. We first analysed the relationship between condition and ornament expression from nine populations over 7 years in a wild bird, the red grouse Lagopus lagopus scoticus. We then manipulated male aggressiveness at the population level by means of testosterone implants in a replicated field experiment. We found that the relationship between condition and ornamentation varied greatly between environments and became stronger when environmental conditions (ECs) were worse or when aggressiveness in the population was experimentally increased. Some ornaments may therefore reliably advertise a better condition only in adverse ECs. Considering environmental heterogeneity can help reconcile conflicting findings regarding the reliability of ornaments as indicators of condition and will help our understanding of sexual selection processes. PMID:22022806

Vergara, Pablo; Martinez-Padilla, J; Mougeot, F; Leckie, F; Redpath, S M

2012-01-01

80

Self-assembled insect muscle bioactuators with long term function under a range of environmental conditions  

PubMed Central

The use of mammalian muscles as device actuators is severely limited by their sensitivity to environmental conditions and short lifetime. To overcome these limitations insect muscle stem cells were used to generate organized 3D muscle constructs with significant enhancements in environmental tolerance and long term function. These tissues self-assembled, self-repaired, survived for months in culture without media replenishment and produced stresses of up to 2 kPa, all under ambient conditions. The muscle tissues continued to function for days even under biologically extreme temperature and pH. Furthermore, the dimensions and geometry of these tissues can be easily scaled to MEMS or meso-scale devices. The versatility, environmental hardiness and long term function provide a new path forward for biological actuators for device needs. PMID:25285210

Baryshyan, A.L.; Domigan, L.J.; Hunt, B.; Trimmer, B.A.; Kaplan, D. L.

2014-01-01

81

Environmental consequences of impact cratering events as a function of ambient conditions on Earth.  

PubMed

The end of the Mesozoic Era is defined by a dramatic floral and faunal turnover that has been linked with the Chicxulub impact event, thus leading to the realization that impact cratering can affect both the geologic and biologic evolution of Earth. However, the environmental consequences of an impact event and any subsequent biological effects rely on several factors, including the ambient environmental conditions and the extant ecosystem structures at the time of impact. Some of the severest environmental perturbations of the Chicxulub impact event would not have been significant in some periods of Earth history. Consequently, the environmental and biological effects of an impact event must be evaluated in the context in which it occurs. PMID:12809133

Kring, David A

2003-01-01

82

Environmental Consequences of Impact Cratering Events as a Function of Ambient Conditions on Earth  

NASA Astrophysics Data System (ADS)

The end of the Mesozoic Era is defined by a dramatic floral and faunal turnover that has been linked with the Chicxulub impact event, thus leading to the realization that impact cratering can affect both the geologic and biologic evolution of Earth. However, the environmental consequences of an impact event and any subsequent biological effects rely on several factors, including the ambient environmental conditions and the extant ecosystem structures at the time of impact. Some of the severest environmental perturbations of the Chicxulub impact event would not have been significant in some periods of Earth history. Consequently, the environmental and biological effects of an impact event must be evaluated in the context in which it occurs.

Kring, David A.

2003-01-01

83

The influence of environmental conditions on aspects of the time budgests of breeding ospreys  

Microsoft Academic Search

Ospreys (Pandion haliaetus) were observed for 350 h in 1975 in southeastern Virginia. Other studies have demonstrated that weather can have an effect on aspects of osprey foraging behavior (e.g., frequency of diving), but for the environmental conditions observed in this study, weather and other variables did not appear to limit the ability of ospreys to feed their young.

Christopher H. Stinson

1978-01-01

84

Postfire environmental conditions influence the spatial pattern of regeneration for Pinus ponderosa  

Microsoft Academic Search

Regeneration of ponderosa pine after fire depends on the patterns of seed availability and the environmental conditions that define safe sites for seedling establishment. A transect approach was applied in 2002 to determine the spatial distribution of regeneration from unburned to burned areas within the landscape impacted by the Jasper Fire of 2000 in the Black Hills of South Dakota

V. H. Bonnet; A. W. Schoettle; W. D. Shepperd

2005-01-01

85

Insects, diseases, animals and environmental conditions can all injure holly plants. Monitor your plants frequently,  

E-print Network

Insects, diseases, animals and environmental conditions can all injure holly plants. Monitor your disorders. Chewing Insects Holly leaf miners are chewing insects that feed on hollies, preferably American insects feed on plant roots. The two- banded Japanese weevil feeds in the daytime, but is easily

Liskiewicz, Maciej

86

Photosynthetic Productivity of Oak Stand under Variable Environmental Conditions and Water Availability  

Microsoft Academic Search

An especial method was applied for calculating the photosynthetic productivity of oak (Quercus robur L.) stand. The methodological basis is that the efficiency of photosynthetic utilization of intercepted PAR over the daylight period depends on environmental conditions and distribution of PAR within the canopy. This method was also used to determine the photosynthetic productivity of individual trees within the stand

A. G. Molchanov

2005-01-01

87

Environmental conditions associated with bat white-nose syndrome mortality in the north-eastern  

E-print Network

Environmental conditions associated with bat white-nose syndrome mortality in the north Summary 1. White-nose syndrome (WNS) is an emerging disease of hibernating North American bats Introduction White-nose syndrome (WNS) is an emerging disease of hiber- nating bats in North America (Blehert

MacDonald, Lee

88

Predicting Snow Velocity in Large Chute Flows Under Different Environmental Conditions  

E-print Network

Predicting Snow Velocity in Large Chute Flows Under Different Environmental Conditions Jonathan Rougier Department of Mathematics University of Bristol, UK Martin Kern Swiss Federal Institute for Snow, and expert judge- ments are combined to make predictions of snow velocity in large chute experiments

Oakley, Jeremy

89

Influences of offshore environmental conditions on wind shear profile parameters in Nantucket Sound  

E-print Network

Influences of offshore environmental conditions on wind shear profile parameters in Nantucket Sound@ecs.umass.edu ABSTRACT Simultaneous wind resource and oceanographic data are available from an offshore monitoring tower how oceanographic data can be used to aid offshore wind resource assessment evaluations. This study

Massachusetts at Amherst, University of

90

Muskrat populations in Virginia's Elizabeth River: Physiological condition and accumulation of environmental contaminants  

Microsoft Academic Search

This study evaluated the physiological condition and environmental contaminant concentrations in muskrats inhabiting the contaminated lower region of the Elizabeth River, Virginia, (USA). Muskrats trapped in the lower region of the Elizabeth River weighed less, had lower mean fat indexes, lower relative spleen weights, greater relative adrenal weights, and an increased incidence of disease and parasitism compared to muskrats trapped

Richard S. Halbrook; Roy L. Kirkpatrick; Patrick F. Scanlon; Michael R. Vaughan; Hugo P. Veit

1993-01-01

91

EVALUATION OF SEVERAL ASSESSMENT METHODS AS INDICATORS OF ESTUARINE ENVIRONMENTAL CONDITIONS  

EPA Science Inventory

Researchers from U.S. EPA's Gulf Ecology Division have conducted a multi-year evaluation of the environmental condition of near-coastal areas affected by different types of stressors. Areas of study have included coastal rivers, transportation canals, residential canals and estua...

92

Annual testicular cycle of blossomheaded parakeet, Psittacula cyanocephala (Aves, Psittacidae), under natural environmental conditions  

Microsoft Academic Search

Histophysiological studies of the annual testicular events in an Indian Psittaciform bird, blossomheaded parakeet Psittacula cyanocephala, under natural environmental conditions revealed that the bird is a seasonal breeder with a single peak in a year. Active spermatogenesis takes place only during February and March, but maximum seasonal maturation of the Leydig cells occurs at least one month before the onset

Saumen Kumar Maitra

1986-01-01

93

The impacts of environmental conditions on microwave radiometry of vegetation: a physical approach  

Microsoft Academic Search

The physical microwave vegetation radiometry model developed at Aerojet is employed to investigate the impacts of environmental conditions on microwave radiometry of vegetation\\/forest. The model is based on solution of the radiative transfer equations and it operates over a wide frequency band in the microwave and millimeter wave regions for both coniferous and deciduous forest as well as grass and

Mostafa A. Karam; GenCorp Aerojet

1996-01-01

94

Environmental Control System Installer/Servicer (Residential Air Conditioning Mechanic). V-TECS Guide.  

ERIC Educational Resources Information Center

This guide provides job relevant tasks, performance objectives, performance guides, resources, learning activitites, evaluation standards, and achievement testing in the occupation of environmental control system installer/servicer (residential air conditioning mechanic). It is designed to be used with any chosen teaching method. The course…

Meyer, Calvin F.; Benson, Robert T.

95

A study of the present condition and problems of marine environmental education in Tokyo Bay  

Microsoft Academic Search

The aim of this paper is to clarify the present condition and problems of environmental education which are carried out at the tidal flats in Tokyo Bay. Two natural tidal flats called 'Sanbanze' and 'Banzu' exist in Tokyo Bay. In recent years, there have been active civic activities for conserving these two tidal flats, and attention is attracted also as

H. Kanke; T. Kondo; K. Yamamoto

2004-01-01

96

Vegetation and environmental conditions in recently restored wetlands in the prairie pothole region of the USA  

Microsoft Academic Search

How closely the vegetation of restored wetlands resembles that of comparable natural wetlands is a function of the probability of propagules of wetland species reaching reflooded wetlands and how similar environmental conditions in the restored wetland are those in the natural wetlands. Three years after reflooding, we examined the vegetation composition, water level fluctuations, soil organic carbon content, and soil

Susan M. Galatowitsch; Arnold G. van der Valk

1996-01-01

97

Influence of Environmental Conditions on Methanogenic Compositions in Anaerobic Biogas Reactors  

Microsoft Academic Search

The influence of environmental parameters on the diversity of methanogenic communities in 15 full-scale biogas plants operating under different conditions with either manure or sludge as feedstock was studied. Fluorescence in situ hybridization was used to identify dominant methanogenic members of the Archaea in the reactor samples; enriched and pure cultures were used to support the in situ identification. Dominance

Dimitar Karakashev; Damien J. Batstone; Irini Angelidaki

2005-01-01

98

The transactional psychobiological nature of cognitive appraisal during exercise in environmentally stressful conditions  

Microsoft Academic Search

Background and Purpose: Successful adaptation to the stress of physical exertion in adverse environmental conditions (heat, cold, high altitude) is of great concern when optimal performance within safe parameters is the goal. The perception of the psychophysical demands imposed by the stressful situation and the perceived capability to cope with these demands is a process that can dramatically alter the

Edmund O. Acevedo; Panteleimon Ekkekakis

2001-01-01

99

The Effects of Poverty, Environmental Degradation, and Gender Conditions on South—to—North Migration  

Microsoft Academic Search

This paper reviews the evidence on how poverty, environmental degradation, and gender conditions affect migration, and then tests some of the hypotheses that emerge using emigration rates from low- and middle-income countries to wealthier industrial countries. At the source country level of analysis, the relationship between income and emigration rates is non-linear. Several other variables, such as economic growth, education

Dane Rowlands

2004-01-01

100

The effect of environmental conditions on the seasonal dormancy pattern and germination of weed seeds  

Microsoft Academic Search

Weeds cause considerable losses in horticultural and agricultural crops. Weeds are still predominantly controlled with herbicides. To reduce the use of chemicals, a better understanding of the biology of weeds is required. In this thesis the effect of environmental conditions on dormancy and germination of Chenopodium album L., Polygonum persicaria L., P. lapathifolium L. subsp. lapathifolium, Sisymbrium officinale (L.) Scop.

H. J. Bouwmeester

1990-01-01

101

Relationship between the fungal complex causing Fusarium head blight of wheat and environmental conditions.  

PubMed

ABSTRACT Over 4 years, the environmental conditions and the causal agents of Fusarium head blight (FHB) disease of wheat were determined in field sites in four European countries: Hungary, Ireland, Italy, and the United Kingdom. Polymerase chain reaction-based methods were used to detect each species causing FHB and quantify its DNA (as a measurement of fungal abundance) in the samples. Canonical correspondence analysis (CCA) was used to determine the relationship of the incidence and abundance of each species with weather variables. CCA indicated that little variability in the species prevalence data was explained by the weather variables. In contrast, a greater proportion of variability in abundance data was accounted for by the weather variables. Most samples contained two or more species and statistical analysis suggested that these species tended to coexist at field sites. CCA also indicated that there were differences in the relationships of the prevalence and abundance of the six FHB species with environmental variables. Fusarium poae was associated with relatively drier and warmer conditions, whereas F. graminearum was associated with warmer/humid conditions. F. avenaceum and F. culmorum were both associated with niches of cooler/wet/humid conditions. Two Microdochium species were associated with regions of relatively cool/moderate temperatures and frequent rainfalls of short duration. The results also suggested that environmental conditions differentially affect the infection and colonization processes, and the comparative abundance of the six species. PMID:18943240

Xu, X-M; Nicholson, P; Thomsett, M A; Simpson, D; Cooke, B M; Doohan, F M; Brennan, J; Monaghan, S; Moretti, A; Mule, G; Hornok, L; Beki, E; Tatnell, J; Ritieni, A; Edwards, S G

2008-01-01

102

Examples of landscape indicators for assessing environmental conditions and problems in urban and suburban areas  

USGS Publications Warehouse

Geo-indicators can help to assess environmental conditions in city urban and suburban areas. Those indicators should be meaningful for understanding environmental changes. From examples of Spanish and American cities, geo-indicators for assessing environmental conditions and changes in urban and suburban areas are proposed. The paper explore two types of geo-indicators. The first type presents general information that can be used to indicate the presence of a broad array of geologic conditions, either favouring or limiting various kinds of uses of the land. The second type of geo-indicator is the one most commonly used, and as a group most easily understood; these are site and problem specific and they are generally used after a problem is identified. Among them, watershed processes, seismicity and physiographic diversity are explained in more detail. A second dimension that is considered when discussing geo-indicators is the issue of scale. Broad scale investigations, covering extensive areas are only efficient at cataloguing general conditions common to much of the area or some outstanding feature within the area. This type of information is best used for policy type decisions. Detailed scale investigations can provide information about local conditions, but are not efficient at cataloguing vast areas. Information gathered at the detailed level is necessary for project design and construction.

Martin-Duque, J. F.; Godfrey, A.; Diez, A.; Cleaves, E.; Pedraza, J.; Sanz, M.A.; Carrasco, R.M.; Bodoque, J.

2002-01-01

103

Effect of environmental conditions on the fatty acid fingerprint of microbial communities  

NASA Astrophysics Data System (ADS)

Lipid biomarkers, especially phospholipids, are routinely used to characterize microbial community structure in environmental samples. Interpretations of these fingerprints mainly depend on rare results of pure cultures which were cultivated under standardized batch conditions. However, membrane lipids (e.g. phopholipid biomarker) build up the interface between microorganisms and their environment and consequently are prone to be adapted according to the environmental conditions. We cultivated several bacteria, isolated from soil (gram-positive and gram-negative) under various conditions e.g. C supply and temperature regimes. Effect of growth conditions on phospholipids fatty acid (PLFA) as well as neutral lipid fatty acids (NLFA) and glycolipid fatty acids (GLFA) was investigated by conventional method of extraction and derivatization, followed by assessments with gas chromatography mass spectrometry (GC-MS). In addition, phospholipids were measured as intact molecules by ultra high performance liquid chromatography - quadrupole - time of flight mass spectrometer (UHPLC-Q-ToF) to further assess the composition of headgroups with fatty acids residues and their response on changing environmental conditions. PLFA fingerprints revealed a strong effect of growth stage, C supply and temperature e.g. decrease of temperature increased the amount of branched and/or unsaturated fatty acids to maintain the membrane fluidity. This strongly changes the ratio of specific to unspecific fatty acids depending on environmental conditions. Therefore, amounts of specific fatty acids cannot be used to assess biomass of a functional microbial group in soil. Intracellular neutral lipids depended less on environmental conditions reflecting a more stable biomarker group but also showed less specific fatty acids then PLFA. Therefore, combination of several lipid classes is suggested as more powerful tool to assess amounts and functionality of environmental microbial communities. Further information was gained from the analysis of intact polar lipids. Ethanolamines and cholines were the most abundant head groups within bacteria and are mainly combined with one specific and one unspecific fatty acid. Reactions on changing environmental conditions occurred mainly by modifications of fatty acids and rarely by a change of the headgroup fingerprint. This approach thus enables to categorize a certain amount of formerly unspecific fatty acids towards a specific microbial group. Ecological understanding for the interface between surrounding environment and cellular metabolism could be deepened by investigating the intact compounds e.g. intact phospholipids of microbial membranes. However, data from further organisms as well as diverse microbial communities are needed to continue the databases of intact phospholipids. Further investigations of diverse microbial communities under changing environmental conditions have to follow these first studies to 1) assess the effects of soil environment on microbial membranes (e.g. associations in biofilms) and 2) assess the effect of interspecific microbial interactions on their membrane properties and lipid fingerprints. Thus, combination of various lipid biomarkers as well as their intact characterization enables a more detailed look into microbial community structure and their respond on environmental conditions, improves our understanding of microbial functioning in ecosystems and enables a more specific estimation of biomass of various microbial groups.

Biryukov, Mikhail; Dippold, Michaela; Kuzyakov, Yakov

2014-05-01

104

Commercial catch rates of the clam Spisula solida reflect local environmental coastal conditions  

NASA Astrophysics Data System (ADS)

The effect of environmental variables and fishing pressure (explanatory variables were lagged 1 year) on commercial catch rates of the clam Spisula solida was studied on an annual basis over a 21 year period in three areas off the Portuguese coast (the Northwest, the Southwest and the South) between 1989 and 2009. Each area showed distinct environmental (oceanographic and hydrological) characteristics. Different sensitivities of S. solida fishing grounds to environmental variables were found among the study areas. On the Northwest coast, the combined effect of NAO indices and sea surface temperature had a positive effect on S. solida fisheries, particularly during the spawning season. On the Southwest coast, the variation of S. solida catches was negatively associated with wind magnitude and positively related with South-Southeast winds. Winter river discharges and summer sea surface temperature negatively affected S. solida catches on the South coast. Fishing effort also affected S. solida catch rates in the South. However, “extreme” changes in environmental conditions were the main drivers of short-term variations in catch rates. These results indicate that variations of S. solida catches strongly reflect a regional signature of local climatic features off the coast. Information on local environmental conditions should therefore be used for the purpose of identifying management actions to ensure long-term sustainability of S. solida fisheries.

Baptista, V.; Leitão, F.

2014-02-01

105

How environmental conditions affect canopy leaf-level photosynthesis in four deciduous tree species  

SciTech Connect

Species composition of temperate forests vary with successional age and seems likely to change in response to significant global climate change. Because photosynthesis rates in co-occurring tree species can differ in their sensitivity to environmental conditions, these changes in species composition are likely to alter the carbon dynamics of temperate forests. To help improve their understanding of such atmosphere-biosphere interactions, the authors explored changes in leaf-level photosynthesis in a 60--70 yr old temperate mixed-deciduous forest in Petersham, Massachusetts (USA). Diurnally and seasonally varying environmental conditions differentially influenced in situ leaf-level photosynthesis rates in the canopies of four mature temperate deciduous tree species: red oak (Quercus rubra), red maple (Acer rubrum), white birch (Betula papyrifera), and yellow birch (Betula alleghaniensis). The authors measured in situ photosynthesis at two heights within the canopies through a diurnal time course on 7 d over two growing seasons. They simultaneously measured a suite of environmental conditions surrounding the leaf at the time of each measurement. The authors used path analysis to examine the influence of environmental factors on in situ photosynthesis in the tree canopies.

Bassow, S.L.; Bazzaz, F.A. [Harvard Univ., Cambridge, MA (United States). Dept. of Organismic and Evolutionary Biology

1998-12-01

106

An adaptive ant colony optimization framework for scheduling environmental flow management alternatives under varied environmental water availability conditions  

NASA Astrophysics Data System (ADS)

water use is increasing and, as such, water for the environment is limited and needs to be managed efficiently. One method for achieving this is the scheduling of environmental flow management alternatives (EFMAs) (e.g., releases, wetland regulators), with these schedules generally developed over a number of years. However, the availability of environmental water changes annually as a result of natural variability (e.g., drought, wet years). To incorporate this variation and schedule EFMAs in a operational setting, a previously formulated multiobjective optimization approach for EFMA schedule development used for long-term planning has been modified and incorporated into an adaptive framework. As part of this approach, optimal schedules are updated at regular intervals during the planning horizon based on environmental water allocation forecasts, which are obtained using artificial neural networks. In addition, the changes between current and updated schedules can be minimized to reduce any disruptions to long-term planning. The utility of the approach is assessed by applying it to an 89km section of the River Murray in South Australia. Results indicate that the approach is beneficial under a range of hydrological conditions and an improved ecological response is obtained in a operational setting compared with previous long-term approaches. Also, it successfully produces trade-offs between the number of disruptions to schedules and the ecological response, with results suggesting that ecological response increases with minimal alterations required to existing schedules. Overall, the results indicate that the information obtained using the proposed approach potentially aides managers in the efficient management of environmental water.

Szemis, J. M.; Maier, H. R.; Dandy, G. C.

2014-10-01

107

Behavior of stressed and unstressed 304L specimens in tuff repository environmental conditions  

SciTech Connect

This paper presents preliminary results of an investigation of the behavior of candidate barrier material for high-level nuclear waste storage, Type 304L stainless steel, in tuff repository environmental conditions. Tuff is a densely welded, devitrified, igneous rock common to the proposed repository site at Yucca Mountain, Nevada. The results discussed include: irradiation corrosion tests, U-bend irradiation corrosion tests, slow strain rate tests, and bent beam stress corrosion tests. Results indicate that Type 304L stainless steel shows excellent resistance to general, localized, and stress corrosion under the environmental and microstructural conditions tested so far. The environmental test conditions are 50 to 100{sup 0}C J-13 well water (non-saline, near neutral pH, and oxic in nature) and saturated steam at 100{sup 0}C. Microstructural conditions include solution annealed and long furnace heat treatments to provoke a sensitized structure. However, this particular type of stainless steel may be susceptible to long-term, low-temperature sensitization because of the combination of expected time at elevated temperature and residual stress in the container after emplacement in the repository. Other grades of austenitic stainless steels are reported to be more resistant to low-temperature sensitization. Future work will therefore include more extensive testing of these grades. 15 references, 5 figures, 7 tables.

Juhas, M.C.; McCright, R.D.; Garrison, R.E.

1984-11-01

108

Environmental conditions associated with bat white-nose syndrome in the north-eastern United States  

USGS Publications Warehouse

2. By 2010, the fungus G. destructans was detected in new areas of North America far from the area it was first observed, as well as in eight European bat species in different countries, yet mortality was not observed in many of these new areas of North America or in any part of Europe. This could be because of the differences in the fungus, rates of disease progression and/or in life-history or physiological traits of the affected bat species between different regions. Infection of bats by G. destructans without associated mortality might also suggest that certain environmental conditions might have to co-occur with fungal infection to cause mortality. 3. We tested the environmental conditions hypothesis using Maxent to map and model landscape surface conditions associated with WNS mortality. This approach was unique in that we modelled possible requisite environmental conditions for disease mortality and not simply the presence of the causative agent. 4. The top predictors of WNS mortality were land use/land cover types, mean air temperature of wettest quarter, elevation, frequency of precipitation and annual temperature range. Model results suggest that WNS mortality is most likely to occur in landscapes that are higher in elevation and topographically heterogeneous, drier and colder during winter, and more seasonally variable than surrounding landscapes. 5. Synthesis and applications. This study mapped the most likely environmental surface conditions associated with bat mortality owing to WNS in the north-eastern United Sates; maps can be used for selection of priority monitoring sites. Our results provide a starting point from which to investigate and predict the potential spread and population impacts of this catastrophic emerging disease.

Flory, Abigail R.; Kumar, Sunil; Stohlgren, Thomas J.; Cryan, Paul M.

2012-01-01

109

Social effects on foraging behavior and success depend on local environmental conditions  

PubMed Central

In social groups, individuals' dominance rank, social bonds, and kinship with other group members have been shown to influence their foraging behavior. However, there is growing evidence that the particular effects of these social traits may also depend on local environmental conditions. We investigated this by comparing the foraging behavior of wild chacma baboons, Papio ursinus, under natural conditions and in a field experiment where food was spatially clumped. Data were collected from 55 animals across two troops over a 5-month period, including over 900 agonistic foraging interactions and over 600 food patch visits in each condition. In both conditions, low-ranked individuals received more agonism, but this only translated into reduced foraging performances for low-ranked individuals in the high-competition experimental conditions. Our results suggest one possible reason for this pattern may be low-ranked individuals strategically investing social effort to negotiate foraging tolerance, but the rank-offsetting effect of this investment being overwhelmed in the higher-competition experimental environment. Our results also suggest that individuals may use imbalances in their social bonds to negotiate tolerance from others under a wider range of environmental conditions, but utilize the overall strength of their social bonds in more extreme environments where feeding competition is more intense. These findings highlight that behavioral tactics such as the strategic investment of social effort may allow foragers to mitigate the costs of low rank, but that the effectiveness of these tactics is likely to be limited in certain environments.

Marshall, Harry H; Carter, Alecia J; Ashford, Alexandra; Rowcliffe, J Marcus; Cowlishaw, Guy

2015-01-01

110

Environmental conditions responsible for the type of precipitation in summer convective storms over Bulgaria  

NASA Astrophysics Data System (ADS)

Environmental conditions of 155 days with precipitation over a part of the Upper Thracian lowland in Bulgaria from May to September of 2002-2006 are studied in order to determine meteorological variables that may be used to specify the type of precipitation (rain or hail) on the ground. The cases have been divided into two samples — days with frontal convective clouds (125) and days with free convection (30). Analyses reveal that the mean values and the thresholds of CAPE and LI during the days with hail are similar to their corresponding values determined for thunderstorm development in other regions in Europe. Results show that none of the analyzed instability indices or environmental parameters alone is able to determine the type of precipitation on the ground. The best classification function of the cases according to the type of precipitation (rain or hail) is derived when the in-cloud characteristics simulated by 1-D numerical cloud model are included together with the instability indices and the environmental parameters as variables in the stepwise discriminant analysis. The analysis reveals that the simulated characteristics of the vertical velocity are an important ingredient in the classification function of the type of precipitation on the ground, due to the incorporation of the non-linear impact of environmental conditions on the formation of precipitation.

Dimitrova, Tsvetelina; Mitzeva, Rumjana; Savtchenko, Aglika

111

Iodine isotopes species fingerprinting environmental conditions in surface water along the northeastern Atlantic Ocean  

PubMed Central

Concentrations and species of iodine isotopes (127I and 129I) provide vital information about iodine geochemistry, environmental conditions and water masses exchange in oceans. Despite extensive investigations of anthropogenic 129I in the Arctic Ocean and the Nordic Seas, concentrations of the isotope in the Atlantic Ocean are, however, still unknown. We here present first data on 129I and 127I, and their species (iodide and iodate) in surface water transect along the northeastern Atlantic between 30° and 50°N. The results show iodate as the predominant species in the analyzed marine waters for both 127I and 129I. Despite the rather constant ratios of 127I?/127IO3?, the 129I?/129IO3? values reveal variations that apparently response to sources, environmental conditions and residence time. These findings provide a new tracer approach that will strongly enhance the application of anthropogenic 129I in ocean environments and impact on climate at the ocean boundary layer. PMID:24284916

He, Peng; Hou, Xiaolin; Aldahan, Ala; Possnert, Göran; Yi, Peng

2013-01-01

112

Dietary Lysine Responses of Male Broilers From 14 to 28 Days of Age Subjected to Different Environmental Conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Dietary amino acid requirements are influenced by environmental conditions. Two experiments examined growth responses of Ross × Ross TP 16 male broilers fed diets varying in digestible (dig) Lys concentrations from 14 to 28 days of age under different environmental conditions. Experiment 1 was condu...

113

Dynamic polarization fluctuation characteristics of optical fiber submarine cables under various environmental conditions  

Microsoft Academic Search

Polarization fluctuation characteristics of optical-fiber submarine cable under 8000-m-deep sea environmental conditions, optical-fiber submarine cable coupling under periodic variable tension, and cable performance during and after installation, are presented. As a worst case, it is demonstrated that the maximum frequency spectrum of polarization fluctuation is less than 200 Hz under dynamic composite stress states. It is found that the polarization

Yoshinori Namihira; Yukio Horiuchi; Shiro Ryu; Kiyofumi Mochizuki; Hiroharu Wakabayashi

1988-01-01

114

Evaluation of chemical conversion material (protective coating) exposed to space environmental conditions  

NASA Technical Reports Server (NTRS)

This report focuses on the development of an operational Rutherford backscattering spectrometry (RBS) system and shows the application of such a system on a space environmental test. Thin films of aluminum and tantalum were deposited on diamond substrates. These films were anodized and preexposure characterization spectra obtained using RBS and total hemispherical reflectance. The samples were exposed to energetic protons then postexposure characterization spectra was obtained using the same techniques. Conclusions based on the comparison of preexposure and postexposure spectra are presented. RBS comparison spectra show no change in the metal/metal oxide interface, while the comparison reflectance data indicate change. Explanations for this reflectance change are presented in this report.

Edwards, D. L.

1993-01-01

115

Environmental health conditions in remote and rural aboriginal communities in western Australia.  

PubMed

During 1994-1995 environmental health conditions of about 13,760 persons in 155 remote and rural Aboriginal communities in 20 local shires in Western Australia (WA) were surveyed. A semiquantitative questionnaire sought data about the communities and their services, including water supplies, power, sanitation and disposal of solid and liquid waste; a separate section dealt with conditions of individual dwellings. Data were recorded by experienced local workers. Thirty-five communities considered to have the worst conditions were evaluated on-site by a team of senior personnel in mid-1995. Environmental health problems were prevalent and often serious: over one-third of the communities had water supply or sanitation problems and 70 per cent had housing problems, with overcrowding and substandard housing being commonplace. Thirty-six per cent had difficulties with waste water disposal, 37 per cent had no rubbish disposal, and in others, the methods of disposal were often inadequate; pests were problems in 44 per cent of communities and the hygiene and maintenance of communal toilets was unacceptable in 25 per cent. Seventy-two per cent had no on-site environmental health worker and 44 per cent had no on-site or visiting medical, nursing or health worker personnel. An action plan was developed and the highest-priority communities were targeted in a program of major works (for example, housing, drainage and sewerage) and minor works, which have been commenced. The remote-area environmental health workers' program is being expanded. Increased intersectoral collaboration and enhanced community involvement in decision making have occurred as a result of this work. PMID:9343897

Gracey, M; Williams, P; Houston, S

1997-08-01

116

Coriander essential oil composition from two genotypes grown in different environmental conditions.  

PubMed

The objective was to study the essential oil composition of coriander fruits in plants growing in environments differing in soil conditions and weediness level. Factorial field experiments were conducted in two locations from the Rolling Pampas, Argentina, and two coriander landraces (European and Argentinean) were tested under two levels of nitrogen fertilization and weediness. Data were evaluated with uni- and multivariate techniques. The variation in the oil composition was related to the relative proportion of the constituents and not to the presence/absence of a particular component. Weather conditions in 1997 favored linalool and camphor in both landraces. Location, fertilization, and weediness also affected the chemical profile. The European landrace showed a more stable concentration of the major components than the Argentinean landrace. These results, which show the relationships between some environmental conditions and the essential oil composition, are useful in the development of innovative strategies aimed to improve oil composition and to manage crop pests. PMID:11982413

Gil, Alejandra; De La Fuente, Elba B; Lenardis, Adriana E; López Pereira, Mónica; Suárez, Susana A; Bandoni, Arnaldo; Van Baren, Catalina; Di Leo Lira, Paola; Ghersa, Claudio M

2002-05-01

117

Photochemical analyses of ozone and related compounds under various environmental conditions  

NASA Astrophysics Data System (ADS)

The photochemical characteristics of ozone (O 3) and its main precursors (e.g. NO x and VOCs) were investigated in relation to the photochemical O 3 budget and O 3-NO x-VOC sensitivity, based on a modeling approach using data sets observed during intensive field campaigns conducted under various environmental conditions (i.e. urban (Seoul), rural (Yang Pyeong), landfill (Dae Gu), coastal (Gwang Yang), and remote sites (Jeju Island). The production of O 3 under most environmental conditions (especially, spring season at the urban site) was found to be more strongly sensitive to VOCs than NO x. At the landfill site and during summer at the rural and coastal sites, the production of O 3 was partially sensitive to NO x. On the other hand, despite the remote air on Jeju Island, the production of O 3 was mainly VOC-sensitive (high NO x levels), but in part NO x-sensitive (low NO x levels), due to the transport processes from different environmental regions (e.g. heavily and less polluted locations).

Song, Sang-Keun; Kim, Yoo-Keun; Shon, Zang-Ho; Ryu, Jae-Yong

2012-02-01

118

[Enzyme activities in nitrogen metabolism of winter wheat and its grain quality under different environmental conditions].  

PubMed

The study with three wheat cultivars grown in two places of Shandong Province showed that the nitrate reductase (NR) and glutamine synthetase (GS) activities in flag leaf and the GS activity in grain were in the sequence of Jimai 20 > Youmai 3 > PH971942, and higher in Longkou than in Taian. The strong gluten wheat cultivars in Longkou had better grain qualities than those in Taian. There were significant correlations between the environmental factors at grain-filling stage and the grain qualities and enzyme activities of wheat. Higher temperature, moderate drought and less sunshine at grain filling stage were benefit to the grain qualities. The protein content of grain was positively correlated with the NR and GS activities in flag leaf for the medium and strong gluten wheat cultivars in Longkou and for the medium gluten wheat cultivars in Taian. Wheat cultivars for different use needed different environmental conditions, while suitable environmental conditions could promote the enzyme activities in nitrogen metabolism of wheat, and thus, improve the qualities of wheat grain. PMID:17209384

Zhao, Chun; Jiao, Nianyuan; Ning, Tangyuan; Wang, Hao; Lou, Jinhua; Hou, Xiangshan; Li, Zengjia

2006-10-01

119

Useful model organisms, indicators, or both? Ground beetles (Coleoptera, Carabidae) reflecting environmental conditions  

PubMed Central

Abstract Classic studies have successfully linked single-species abundances, life-history traits, assemblage structures and biomass of carabid beetles to past and present, human-caused environmental impacts and variation in ‘natural’ conditions. This evidence has led many to suggest carabids to function as ‘indicators’ ? a term that bears multiple meanings. Here, a conservation-oriented definition for an indicator is used, carabid indicator potential from seven views is evaluated, and ways to proceed in indicator research are discussed. (1) Carabid species richness poorly indicates the richness and abundance of other taxa, which underlines the importance of using multiple taxa in environmental assessments. The ability of assemblage indices and specialist or functional-group abundances to reflect rare species and habitats should be examined in detail. (2) Experimental evidence suggests that carabids may potentially serve as keystone indicators. (3) Carabids are sensitive to human-altered abiotic conditions, such as pesticide use in agro-ecosystems and heavy metal contamination of soils. Carabids might thus reflect ecological sustainability and ‘ecosystem health’. (4) Carabid assemblages host abundant species characteristic of particular habitat types or successional stages, which makes them promising dominance indicators. (5) Carabids reflect variation in ‘natural’ conditions, but vegetation and structural features are more commonly adopted as condition indicators. Carabids nevertheless provide yet another, equally accurate, view on the structure of the environment. (6) Carabids may function as early-warning signalers, as suggested by recent studies linking climate and carabid distributions. (7) Carabids reflect natural and human-caused disturbances and management, but the usefulness of these responses for conservation purposes requires further research. In summary, European carabids appear useful model organisms and possibly indicators because they are diverse, taxonomically and ecologically well-known, efficiently reflect biotic and abiotic conditions, are relevant at multiple spatial scales, and are easy to collect in sufficiently large numbers to allow statistical analyses. The assumption that carabid responses would reflect rare environmental conditions or the responses of rare and threatened species ? crucial information for conservationists and managers ? has not yet been critically evaluated. Even if it holds, the usefulness will be context dependent: species and their populations vary, conditions vary, questions put forward vary, and assessment goals vary. PMID:21738418

Koivula, Matti J.

2011-01-01

120

Environmental Conditions Influence the Plant Functional Diversity Effect on Potential Denitrification  

PubMed Central

Global biodiversity loss has prompted research on the relationship between species diversity and ecosystem functioning. Few studies have examined how plant diversity impacts belowground processes; even fewer have examined how varying resource levels can influence the effect of plant diversity on microbial activity. In a field experiment in a restored wetland, we examined the role of plant trait diversity (or functional diversity, (FD)) and its interactions with natural levels of variability of soil properties, on a microbial process, denitrification potential (DNP). We demonstrated that FD significantly affected microbial DNP through its interactions with soil conditions; increasing FD led to increased DNP but mainly at higher levels of soil resources. Our results suggest that the effect of species diversity on ecosystem functioning may depend on environmental factors such as resource availability. Future biodiversity experiments should examine how natural levels of environmental variability impact the importance of biodiversity to ecosystem functioning. PMID:21311768

Sutton-Grier, Ariana E.; Wright, Justin P.; McGill, Bonnie M.; Richardson, Curtis

2011-01-01

121

The effect of environmentally relevant conditions on PVP stabilised gold nanoparticles.  

PubMed

Nanoparticles are a major product from the nanotechnology industry and have been shown to have a potentially large environmental exposure and hazard. In this study, sterically stabilised polyvinyl pyrrolidone (PVP) 7 nm gold nanoparticles (NPs) were produced and characterised as prepared by surface plasmon resonance (SPR), size and aggregation, morphology and surface charge. Changes in these properties with changes in environmentally relevant conditions (pH, ionic strength, Ca concentration and fulvic acid presence) were quantified. These sterically stabilised NPs showed no aggregation with changes in pH or inorganic ions, even under high (0.1 M) Ca concentrations. In addition, the presence of fulvic acid resulted in no observable changes in SPR, size, aggregation or surface chemistry, suggesting limited interaction between the PVP stabilised nanoparticles and fulvic acid. Due to the lack of aggregation and interaction, these NPs are expected to be highly mobile and potentially bioavailable in the environment. PMID:22967928

Hitchman, Adam; Smith, Gregory H Sambrook; Ju-Nam, Yon; Sterling, Mark; Lead, Jamie R

2013-01-01

122

Adsorption of a Protein Monolayer via Hydrophobic Interactions Prevents Nanoparticle Aggregation under Harsh Environmental Conditions  

PubMed Central

We find that citrate-stabilized gold nanoparticles aggregate and precipitate in saline solutions below the NaCl concentration of many bodily fluids and blood plasma. Our experiments indicate that this is due to complexation of the citrate anions with Na+ cations in solution. A dramatically enhanced colloidal stability is achieved when bovine serum albumin is adsorbed to the gold nanoparticle surface, completely preventing nanoparticle aggregation under harsh environmental conditions where the NaCl concentration is well beyond the isotonic point. Furthermore, we explore the mechanism of the formation of this albumin ‘corona’ and find that monolayer protein adsorption is most likely ruled by hydrophobic interactions. As for many nanotechnology-based biomedical and environmental applications, particle aggregation and sedimentation are undesirable and could substantially increase the risk of toxicological side-effects, the formation of the BSA corona presented here provides a low-cost bio-compatible strategy for nanoparticle stabilization and transport in highly ionic environments. PMID:23914342

Dominguez-Medina, Sergio; Blankenburg, Jan; Olson, Jana; Landes, Christy F.; Link, Stephan

2013-01-01

123

Influence of high gravity process conditions on the environmental impact of ethanol production from wheat straw.  

PubMed

Biofuel production processes at high gravity are currently under development. Most of these processes however use sugars or first generation feedstocks as substrate. This paper presents the results of a life cycle assessment (LCA) of the production of bio-ethanol at high gravity conditions from a second generation feedstock, namely, wheat straw. The LCA used lab results of a set of 36 process configurations in which dry matter content, enzyme preparation and loading, and process strategy were varied. The LCA results show that higher dry matter content leads to a higher environmental impact of the ethanol production, but this can be compensated by reducing the impact of enzyme production and use, and by polyethylene glycol addition at high dry matter content. The results also show that the renewable and non-renewable energy use resulting from the different process configurations ultimately determine their environmental impact. PMID:25299491

Janssen, Matty; Tillman, Anne-Marie; Cannella, David; Jørgensen, Henning

2014-12-01

124

PRESIDENCY CONCLUSIONS BRUSSELS EUROPEAN COUNCIL  

E-print Network

in Brussels on 25/26 March 2004 for its annual meeting on the Lisbon Strategy and the economic, social and employment generation together with a high degree of social cohesion and environmental protection. 7. However, the pace of reform needs to be significantly stepped up if the 2010 targets are to be achieved

125

[Fluorescence parameters of chlorophyll in leaves of caules plants in different environmental conditions].  

PubMed

The functional state of medicinal plants of Convallaria majalis L., Vaccinium vitis-idaeae L., Arctostaphylos uva-ursi L. in connection with heavy metal accumulation in their leaves under man impact was studied by the pulse-amplitude-modulation (PAM) fluorometric method. The relative yield of variable fluorescence (F(v)/F(m)), induction of fluorescence of chlorophyll, and fluorescence quenching processes in leaves at different distances from the local Kirov-Sovetsk, Kirov-Omutninsk road in Kirov region were analyzed. Changes in biophysical characteristics with the increasing content of heavy metals in leaves were demonstrated. The most informative characteristic is F(v)/F(m). Its value correlates with the activity of the photosynthetic apparatus and reflects the potential effeciency of photosynthesis. The better are the environmental conditions of plant growth, the higher is the F(v)/F(m) ratio and the lower is its average statistical deviation. Fluorescence induction curves do not always vary in shape under our ecological conditions, indicating relatively favorable conditions at places of plant growth investigated. The rate of the environmental pollution in the investigated region is not critical, since the content of heavy metal in leaves does not change considerably with the distance from the road. PMID:16358792

Iakovleva, O V; Talipova, E V; Kukarskikh, G P; Krendeleeva, T E; Rubin, A B

2005-01-01

126

Salt tolerance of rhizobial populations from contrasting environmental conditions: understanding the implications of climate change.  

PubMed

It is predicted that global climate change may alter environmental parameters such as rainfall distribution which in turn may alter the salinity of soils with unpredictable effects upon soil microbial populations. In the present work the tolerance to salinity of rhizobia, isolated from locations with contrasting climatic conditions, and the potential of strains to fix nitrogen symbiotically under saline conditions were investigated. Since plasmids may encode key genes related to growth and survival under environmental stress conditions, which will reflect on protein synthesis, both the plasmid and protein profiles were analyzed. A multivariate statistical approach related salt tolerance to the origin of the isolates, identifying rainfall and water availability as a possible factor explaining the differences in salt tolerance displayed by rhizobia isolates. The classification analysis allowed the subdivision of isolates in terms of salt tolerance into extremely sensitive (?0.15 %), sensitive (0.15-0.6 %), moderately tolerant (0.9-1.5 %), tolerant (2.1-3.6 %) and extremely tolerant (?5.4 %). Taken all together it was shown that plasmids are involved in salt tolerance and that the impact of salinity on the protein profile and nitrogen fixation varied according to the salt tolerance of the strains, evidencing the susceptibility of rhizobial communities to changes in rainfall regimes. PMID:25318616

Cardoso, Paulo; Freitas, Rosa; Figueira, Etelvina

2015-01-01

127

Genomic sweep and potential genetic rescue during limiting environmental conditions in an isolated wolf population.  

PubMed

Genetic rescue, in which the introduction of one or more unrelated individuals into an inbred population results in the reduction of detrimental genetic effects and an increase in one or more vital rates, is a potentially important management tool for mitigating adverse effects of inbreeding. We used molecular techniques to document the consequences of a male wolf (Canis lupus) that immigrated, on its own, across Lake Superior ice to the small, inbred wolf population in Isle Royale National Park. The immigrant's fitness so exceeded that of native wolves that within 2.5 generations, he was related to every individual in the population and his ancestry constituted 56 per cent of the population, resulting in a selective sweep of the total genome. In other words, all the male ancestry (50% of the total ancestry) descended from this immigrant, plus 6 per cent owing to the success of some of his inbred offspring. The immigration event occurred in an environment where space was limiting (i.e. packs occupied all available territories) and during a time when environmental conditions had deteriorated (i.e. wolves' prey declined). These conditions probably explain why the immigration event did not obviously improve the population's demography (e.g. increased population numbers or growth rate). Our results show that the beneficial effects of gene flow may be substantial and quickly manifest, short-lived under some circumstances, and how the demographic benefits of genetic rescue might be masked by environmental conditions. PMID:21450731

Adams, Jennifer R; Vucetich, Leah M; Hedrick, Philip W; Peterson, Rolf O; Vucetich, John A

2011-11-22

128

Genomic sweep and potential genetic rescue during limiting environmental conditions in an isolated wolf population  

PubMed Central

Genetic rescue, in which the introduction of one or more unrelated individuals into an inbred population results in the reduction of detrimental genetic effects and an increase in one or more vital rates, is a potentially important management tool for mitigating adverse effects of inbreeding. We used molecular techniques to document the consequences of a male wolf (Canis lupus) that immigrated, on its own, across Lake Superior ice to the small, inbred wolf population in Isle Royale National Park. The immigrant's fitness so exceeded that of native wolves that within 2.5 generations, he was related to every individual in the population and his ancestry constituted 56 per cent of the population, resulting in a selective sweep of the total genome. In other words, all the male ancestry (50% of the total ancestry) descended from this immigrant, plus 6 per cent owing to the success of some of his inbred offspring. The immigration event occurred in an environment where space was limiting (i.e. packs occupied all available territories) and during a time when environmental conditions had deteriorated (i.e. wolves' prey declined). These conditions probably explain why the immigration event did not obviously improve the population's demography (e.g. increased population numbers or growth rate). Our results show that the beneficial effects of gene flow may be substantial and quickly manifest, short-lived under some circumstances, and how the demographic benefits of genetic rescue might be masked by environmental conditions. PMID:21450731

Adams, Jennifer R.; Vucetich, Leah M.; Hedrick, Philip W.; Peterson, Rolf O.; Vucetich, John A.

2011-01-01

129

Thermal Cyclic Behavior of Thermal and Environmental Barrier Coatings Investigated Under High-Heat-Flux Conditions  

NASA Technical Reports Server (NTRS)

Environmental barrier coatings (EBC's) have been developed to protect silicon-carbide- (SiC) based ceramic components in gas turbine engines from high-temperature environmental attack. With continuously increasing demands for significantly higher engine operating temperature, future EBC systems must be designed for both thermal and environmental protection of the engine components in combustion gases. In particular, the thermal barrier functions of EBC's become a necessity for reducing the engine-component thermal loads and chemical reaction rates, thus maintaining the required mechanical properties and durability of these components. Advances in the development of thermal and environmental barrier coatings (TBC's and EBC's, respectively) will directly impact the successful use of ceramic components in advanced engines. To develop high-performance coating systems, researchers must establish advanced test approaches. In this study, a laser high-heat-flux technique was employed to investigate the thermal cyclic behavior of TBC's and EBC's on SiC-reinforced SiC ceramic matrix composite substrates (SiC/SiC) under high thermal gradient and thermal cycling conditions. Because the laser heat flux test approach can monitor the coating's real-time thermal conductivity variations at high temperature, the coating thermal insulation performance, sintering, and delamination can all be obtained during thermal cycling tests. Plasma-sprayed yttria-stabilized zirconia (ZrO2-8 wt% Y2O3) thermal barrier and barium strontium aluminosilicate-based environmental barrier coatings (BSAS/BSAS+mullite/Si) on SiC/SiC ceramic matrix composites were investigated in this study. These coatings were laser tested in air under thermal gradients (the surface and interface temperatures were approximately 1482 and 1300 C, respectively). Some coating specimens were also subject to alternating furnace cycling (in a 90-percent water vapor environment at 1300 C) and laser thermal gradient cycling tests (in air), to investigate the water vapor effect. All cyclic tests were conducted using a 60-min hot-time temperature.

Zhu, Dongming; Lee, Kang N.; Miller, Robert A.

2002-01-01

130

The effect of environmental conditions on ergosterol and trichothecene content of naturally contaminated oat grain.  

PubMed

Oat plants, similar to other cereals, are susceptible to invasion by fungal pathogens and saprophytes, but the severity of disease symptoms and the extent of fungal growth depend to a considerable degree on environmental conditions. This study aimed to analyse the dependence of ergosterol and trichothecene production in oat grain on environmental conditions. Three oat cultivars were cultivated in 10 localities across Poland under natural conditions of fungal infection. Analysis of the effect of weather conditions during the growing season on ergosterol content and total trichothecene Fusarium toxin content in grain showed that they are negatively correlated with the sum of precipitation in the dry month of June, i.e. at the flowering stage of oats. Significant rainfall in July (256 % multiannual average) resulted in a considerable growth of saprophytic fungi and, as a consequence, in high ERG levels in grain (mean 14.0 mg/kg). Although the total trichothecene content was relatively low (< 150 microg/kg), a significant correlation was observed between this trait and ergosterol content of grain (r = 0.7313). Higher values of correlation coefficients were recorded for the dependence of trichothecene A, as well as trichothecene A and NIV, and ERG levels, amounting to r = 0.8703 and r = 0.7748, respectively. This was probably caused by specific weather conditions manifested by slight precipitation during panicle flowering, which promoted the growth of pathogens (F. poae, F. sporotrichioides) producing trichothecenes A (T-2 toxin, HT-2 toxin and NIV). In addition, a significant influence of locality on values of both traits was recorded. Variation between cultivars was not significant. PMID:19061262

Perkowski, Juliusz; Basi?ski, Tomasz; Wiwart, Marian; Kostecki, Marian; Bu?ko, Maciej; Matysiak, Anna

2008-12-01

131

Oxidative stress in limpets exposed to different environmental conditions in the Beagle Channel.  

PubMed

The aim of this work was to study the oxidative profile of digestive glands of two limpets species (Nacella (Patinigera) magellanica and Nacella (Patinigera) deaurata) exposed to different environmental conditions. The intertidal population of N. (P.) magellanica is subjected to a wide variety of stresses not experienced by N. (P.) deaurata. Although a typical electron paramagnetic resonance (EPR) spectrum of ascorbyl radical in digestive gland from both limpets was observed, neither ascorbyl radical content nor the ascorbyl radical content/ascorbate content ratio was significantly different, suggesting that the difference in the environmental conditions did not appear to be responsible for developing alterations in the oxidative status of both organisms at the hydrophilic level (e.g. cytosol). Lipid peroxidation in the digestive glands was estimated, both as the content of thiobarbituric acid reactive substances (TBARS) and as the content of lipid radicals assessed by EPR, in both organisms. TBARS and lipid radical content were 34.8 and 36.5%, respectively, lower in N. (P.) magellanica as compared to N. (P.) deaurata. On the other hand, total iron content and the rate of generation of superoxide anion were 47.9 and 51.4%, respectively, lower in N. (P.) magellanica as compared to N. (P.) deaurata. The activity of catalase and superoxide dismutase (SOD) was 35.3 and 128.6% higher in N. (P.) magellanica as compared to N. (P.) deaurata, respectively. No significant differences were determined between the digestive glands of both molluscs regarding the content of total thiols. alpha-Tocopherol and beta-carotene content were significantly lower in N. (P.) magellanica as compared to N. (P.) deaurata. A distinctive EPR signal for the adduct Fe--MGD--NO (g = 2.03 and a(N) = 12.5 G) was detected in the homogenates of digestive glands of both limpets. A significant difference in the content of the Fe-MGD-NO adduct in digestive glands from N. (P.) magellanica and N. (P.) deaurata (491 +/- 137 and 839 +/- 63 pmol/g FW, respectively) was observed. Taken as a whole, the data presented here indicated that coping with environmental stressing conditions requires a complex adjustment of the physiological metabolic pathways to ensure survival by minimizing intracellular damage. It is likely that N. (P.) magellanica has a particular evolutionary adaptation to extreme environmental conditions by keeping iron content low and antioxidant activities high. PMID:15312715

Malanga, Gabriela; Estevez, Maria Susana; Calvo, Jorge; Puntarulo, Susana

2004-09-20

132

A correlational analysis of the effects of changing environmental conditions on the NR atomic hydrogen maser  

NASA Technical Reports Server (NTRS)

An extensive statistical analysis has been undertaken to determine if a correlation exists between changes in an NR atomic hydrogen maser's frequency offset and changes in environmental conditions. Correlation analyses have been performed comparing barometric pressure, humidity, and temperature with maser frequency offset as a function of time for periods ranging from 5.5 to 17 days. Semipartial correlation coefficients as large as -0.9 have been found between barometric pressure and maser frequency offset. Correlation between maser frequency offset and humidity was small compared to barometric pressure and unpredictable. Analysis of temperature data indicates that in the most current design, temperature does not significantly affect maser frequency offset.

Dragonette, Richard A.; Suter, Joseph J.

1992-01-01

133

Effect of environmental conditions on the properties of concretes with different cement types  

Microsoft Academic Search

The paper reports on the changes in properties of concretes with different cement types associated with environmental conditions. Three strength classes with three different cement types (ordinary portland cement PC 42.5 (CEM I 42.5), portland composite cements PKC-A 42.5 (CEM II\\/A-M 42.5) and PKC-B 32.5R (CEM II\\/B-M 32.5R)) were used in the study. Also, a mixture was prepared with PC

Niyazi Ugur Kockal; Fikret Turker

2007-01-01

134

Physiological and genetic analysis of Arabidopsis thaliana anthocyanin biosynthesis mutants under chronic adverse environmental conditions  

PubMed Central

Anthocyanin production is a characteristic response of flowering plants to unfavourable environmental conditions. The potential roles of flavonoids and anthocyanins in plant growth were investigated by growing Arabidopsis thaliana anthocyanin production mutants (transparent testa) under limiting nitrogen and high light conditions. Inability to produce kaempferol or subsequent intermediate compounds by some transparent testa lines was correlated with less biomass accumulation in mature plants compared with wild-type control plants under all growth conditions tested. However, under both limiting nitrogen and high light chronic stress conditions, mutant lines defective in later steps of the anthocyanin production pathway produced the same or more biomass than wild-type plants. No difference in senescence between transparent testa and wild-type plants was found using chlorophyll catabolism and SAG12 expression measurements, and no mutants were impaired in the ability to remobilize nutrients from the vegetative to reproductive tissues. Moreover, the absence of anthocyanin and/or upstream flavonoids does not affect the ability of plants to respond to limiting nitrogen by reducing photosynthetic capacity. These results support a role for kaempferol and quercetin accumulation in normal plant growth and development. Further, the absence of anthocyanins has no effect on plant growth under the chronic stress conditions tested. PMID:23162120

Rothstein, Steven J.

2013-01-01

135

Portuguese native Artemia parthenogenetica resisting invasion by Artemia franciscana - Assessing reproductive parameters under different environmental conditions  

NASA Astrophysics Data System (ADS)

There is widespread interest in the conservation of native Artemia biodiversity. In Portugal, only two known populations of native Artemia remain: one in the Rio Maior salina, the other in the Aveiro salina complex, both of the diploid Artemia parthenogenetica species. All other Portuguese hypersaline environments where Artemia can be found have been invaded by Artemia franciscana, which has eradicated the native strains. Invasiveness and resilience of, respectively, exotic and indigenous species are thought to depend on strain-specific traits and adaptation to local conditions. This work evaluates the reproductive performance of the two Portuguese native strains and the invasive species exposed to different salinities, temperatures, photoperiods and food supplies. Reproduction periods, quantity and quality of offspring varied significantly, depending on both the Artemia strain and environmental conditions. A. parthenogenetica from Rio Maior reproduced better than A. franciscana at high salinity (150) and low food supply, which may reflect an adaptation to its biotope that aids its resistance to invasion. But A. parthenogenetica form Aveiro performed much worse than its invasive competitor, under most of the conditions tested. It is unlikely that A. franciscana has not been introduced in this salina by chance alone. Other biological traits of the local A. parthenogenetica or adaptation to unstudied local factors (e.g. pollution) are probably responsible for this strain's survival. Further knowledge on specific local conditions and trait-specific tolerances to biotic and abiotic conditions are needed to understand (non-)invasion patterns and preserve the remaining native populations.

Pinto, Pedro M.; Hontoria, Francisco; Vieira, Natividade; Bio, Ana

2014-05-01

136

Mobile Computig: Conclusions Evaggelia Pitoura  

E-print Network

' & $ % Mobile Computig: Conclusions Evaggelia Pitoura Computer Science Department, University; ' & $ % Mobile Computing Models ffl What is the best way to partition a computation as well as the functionality of a system or application between stationary and mobile elements? Adaptivity: the functionality assigned

Pitoura, Evaggelia

137

Long-term effects of warming and ocean acidification are modified by seasonal variation in species responses and environmental conditions  

PubMed Central

Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for seasonal variation to modify species and ecosystem responses to these stressors has received little attention. Here, using the longest experiment to date (542 days), we investigate how the interactive effects of warming and ocean acidification affect the growth, behaviour and associated levels of ecosystem functioning (nutrient release) for a functionally important non-calcifying intertidal polychaete (Alitta virens) under seasonally changing conditions. We find that the effects of warming, ocean acidification and their interactions are not detectable in the short term, but manifest over time through changes in growth, bioturbation and bioirrigation behaviour that, in turn, affect nutrient generation. These changes are intimately linked to species responses to seasonal variations in environmental conditions (temperature and photoperiod) that, depending upon timing, can either exacerbate or buffer the long-term directional effects of climatic forcing. Taken together, our observations caution against over emphasizing the conclusions from short-term experiments and highlight the necessity to consider the temporal expression of complex system dynamics established over appropriate timescales when forecasting the likely ecological consequences of climatic forcing. PMID:23980249

Godbold, Jasmin A.; Solan, Martin

2013-01-01

138

Environmental and physiological conditions affecting Tetrahymena sp. infection in guppies, Poecilia reticulata Peters.  

PubMed

Parasitic infections caused by Tetrahymena sp. constitute a serious problem in guppies, Poecilia reticulata. Tetrahymena was isolated from skin lesions of naturally infected guppies in a commercial aquaculture farm, cultured in vitro and used in subsequent experimental infections. In addition to guppies, angelfish, Pterophyllum scalare, platyfish, Xiphophorus maculates, and neontetra, Paracheirodon innesi, were susceptible, whereas tilapia (Oreochromis niloticus xO. aureus) was resistant. The ciliate had a high affinity for dead fish. Skin abrasion did not affect the infection, but fish with gas bubble disease exhibited a significantly higher infection than non-affected fish. Infection was significantly higher when fish were exposed to high levels of ammonia, high organic load and low water temperatures. Under shipment conditions, infection was significantly elevated. Full recovery was achieved at a low fish density. Results suggest that poor environmental and physiological conditions enhance infection with Tetrahymena sp. PMID:16266327

Pimenta Leibowitz, M; Ariav, R; Zilberg, D

2005-09-01

139

Robust ultrasonic damage detection under complex environmental conditions using singular value decomposition.  

PubMed

Guided wave ultrasonics is an attractive monitoring technique for damage diagnosis in large-scale plate and pipe structures. Damage can be detected by comparing incoming records with baseline records collected on intact structure. However, during long-term monitoring, environmental and operational conditions often vary significantly and produce large changes in the ultrasonic signals, thereby challenging the baseline comparison based damage detection. Researchers developed temperature compensation methods to eliminate the effects of temperature variation, but they have limitations in practical implementations. In this paper, we develop a robust damage detection method based on singular value decomposition (SVD). We show that the orthogonality of singular vectors ensures that the effect of damage and that of environmental and operational variations are separated into different singular vectors. We report on our field ultrasonic monitoring of a 273.05mm outer diameter pipe segment, which belongs to a hot water piping system in continuous operation. We demonstrate the efficacy of our method on experimental pitch-catch records collected during seven months. We show that our method accurately detects the presence of a mass scatterer, and is robust to the environmental and operational variations exhibited in the practical system. PMID:25600118

Liu, Chang; Harley, Joel B; Bergés, Mario; Greve, David W; Oppenheim, Irving J

2015-04-01

140

Physiological behaviour of gliotoxigenic Aspergillus fumigatus sensu stricto isolated from maize silage under simulated environmental conditions.  

PubMed

Environmental conditions play a key role in fungal development. During the silage production process, humidity, oxygen availability and pH vary among lactic-fermentation phases and among different silage sections. The aim of this work was to study the physiological behaviour of gliotoxicogenic Aspergillus fumigatus strains isolated from maize silage under simulated natural physicochemical conditions - different water activities (aW), temperatures (Tº), pH and oxygen pressure - on the growth parameters (growth rate and lag phase) and gliotoxin production. The silage was made with the harvested whole maize plant that was chopped and used for trench-type silo fabrication. Water activity and pH of the silage samples were determined. Total fungal counts were performed on Dichloran Rose Bengal Chloramphenicol agar and Dichloran 18% Glycerol agar. The morphological identification of A. fumigatus was performed with different culture media and at different growth temperature to observe microscopic and macroscopic characteristics. Gliotoxin production by A. fumigatus was determined by HPLC. All strains isolated were morphologically identified as A. fumigatus. Two A. fumigatus strains isolated from the silage samples were selected for the ecophysiological study (A. fumigatus sensu stricto RC031 and RC032). The results of this investigation showed that the fungus grows in the simulated natural physicochemical conditions of corn silage and produces gliotoxin. The study of the physiological behaviour of gliotoxigenic A. fumigatus under simulated environmental conditions allowed its behaviour to be predicted in silage and this will in future enable appropriate control strategies to be developed to prevent the spread of this fungus and toxin production that leads to impairment and reduced quality of silage. PMID:25599419

Alonso, V; Díaz Vergara, L; Aminahuel, C; Pereyra, C; Pena, G; Torres, A; Dalcero, A; Cavaglieri, L

2015-02-01

141

Music venues and hearing loss: Opportunities for and barriers to improving environmental conditions.  

PubMed

This study explores the opportunities for and barriers to improving environmental conditions in order to reduce the risk for music-induced hearing loss in people who attend music venues. Individual semi-structured interviews were held with 20 representatives of music venues and of governmental organizations, according to a semi-structured interview guide. The interviews were audiotaped, transcribed, and systematically coded using a content-analysis technique. Reported opportunities to reduce music volume included improving the acoustics and installing advanced speaker systems. The most important barrier reported was the lack of clear definitions of what levels of high-volume music are hazardous. Other barriers mentioned included economic considerations, and the beliefs that visitors demand high-volume music in music venues and are personally responsible for their own hearing. Before measures to improve environmental conditions are implemented, the exact dangers of exposure to high-volume music have to be established. Evidence-based guidelines and safety standards for leisure-time noise exposure should therefore be developed. PMID:19842806

Vogel, Ineke; van der Ploeg, Catharina P B; Brug, Johannes; Raat, Hein

2009-08-01

142

Effects of environmental conditions on inducing charge structures of thunderstorms over Eastern India  

NASA Astrophysics Data System (ADS)

It is well known that environmental conditions like convective instability, aerosol loading, and availability of moisture content affect the polarity of charge structures of thunderstorms. The electrical characteristics of thunderstorms observed during the pre-monsoon season of year 2009, over Eastern India were studied to identify the effects of different environmental conditions on charge structures of thunderstorms occurring over this region. Electric field and Maxwell current data suggest that at least one of these thunderstorms had an inverted charge structure. Doppler RADAR, radiosonde, and Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Depth (AOD) data have been used to compare the microphysical and dynamical characteristics of these thunderstorms. The thermo dynamical structure observed by radiosonde during the day on which an inverted polarity thunderstorm was observed showed very high CAPE in the mixed-phase region compared to other thunderstorm days. Furthermore, the AOD peaked 1 day before this thunderstorm. The back trajectories of winds also suggest that the aerosols might have been transported from a desert region on that day. It has been proposed that the large ice nuclei concentration can produce dominant positive charge in the lower portion of the mixed-phase region by maintaining ice saturation.

Pawar, Sunil Dnyandeo; Gopalakrishnan, Venkatachalam; Murugavel, Palani; Sinkevich, Andrei; Lal, Deen Mani

2014-12-01

143

Dependency of seed dormancy types on embryo traits and environmental conditions in Ribes species.  

PubMed

The hypothesis that seed dormancy may be dependent on environmental conditions and seed morphological traits was tested for six Ribes species, across an altitudinal gradient of 1300 m and a longitudinal separation of 120°. Embryo measurements and seed germination experiments were conducted for R. alpinum L., R. hudsonianum Richardson var. petiolare (Douglas) Jancz., R. nevadaense Kellogg, R. roezlii Regel var. cruentum (Greene) Rehder and R. speciosum Pursh, and data taken from the literature for R. multiflorum Kit. ex Schult. ssp. sandalioticum Arrigoni. Germination was compared with seed viability to reveal proportional seed dormancy, which was then correlated to seed/embryo morphological traits and these traits related to the seed provenance environment. The embryos of all the investigated species are linear underdeveloped and all had a morphological component of seed dormancy (MD). Seeds of R. roezlii, R. hudsonianum and R. nevadaense required a temperature and/or hormone pre-treatment in order to germinate, highlighting morphophysiological seed dormancy (MPD). Seed dormancy was found to be strongly negatively correlated with embryo length, but not with embryo to seed (E:S) ratio or seed mass. Initial embryo length was positively related to mean annual temperature. Seed dormancy in the investigated Ribes species could be quantified and predicted by the interaction of embryo traits and environmental conditions. This approach may be helpful in assessing and predicting seed dormancy in the Ribes genus and in other genera and families with underdeveloped embryos. PMID:24138146

Mattana, E; Stuppy, W H; Fraser, R; Waller, J; Pritchard, H W

2014-07-01

144

Positive and negative interactions between environmental conditions affecting Cercocarpus ledifolius seedling survival.  

PubMed

We evaluated the balance between positive and negative effects of environmental conditions on first-year seedling survival of the tree Cercocarpus ledifolius during two summers, 1996 and 1997. The experimental design was fully crossed with two levels of water, with and without supplementation, two levels of herbivory, with and without protection, and three major microhabitats, open interspaces, under the canopy of Artemisia tridentata shrubs, and under the canopy of mature C. ledifolius trees. Effects of drought and herbivory on seedling survival depended on the year. Water supplementation and herbivory protection during the dry summer of 1996 (27.7 mm) generally increased seedling survival. Additionally, survival tended to be greatest beneath C. ledifolius canopies. More important ecologically were the significant interactions. In 1996, water supplementation increased survival more with than without herbivory protection. The three-way interaction, treatment-microhabitat combination, was most important; by far the greatest survival was in the water supplementation and herbivory protection in the tree microhabitat. During the wet summer of 1997 (158.5 mm), neither water supplementation, herbivory protection, nor microhabitat were significant as main effects. The water-supplemented and herbivory-protected treatment again combined to yield highest survival, but this time in open interspaces rather than beneath trees. Our study shows how the importance of individual limiting factors and the relative favorableness of particular microhabitats appear to change across years depending on environmental conditions. PMID:24577694

Ibáñez, I; Schupp, E W

2001-12-01

145

Performance of diffusion-barrier scintillation cells under a variety of controlled environmental conditions  

SciTech Connect

The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center (TMC) at the Grand Junction, Colorado, Projects Office (GJPO), in part, to develop and evaluate new devices for the DOE remedial action projects. The TMC charged the GJPO Radon Laboratory, under the management of UNC Geotech (UNC), with developing and testing a passive scintillation-type, time-averaging radon monitor. Two types of monitors were developed--a diffusion-barrier scintillation cell (DBSC) and a diffusion-barrier liquid scintillation cell (DBLSC). The performance of the DBSCs was tested under different relative humidities, temperatures, and wind speeds. The test results of the DBSCs showed no statistically significant change in accuracy due to the environmental test conditions. Radon-concentration measurement results for diffusion-barrier charcoal canisters (DBCC), exposed along with the DBSCs, did show significant effects due to wind and temperature, but no effects due to relative humidity. The performance of the DBLSCs under a variety of environmental conditions was not tested because a sufficiently sensitive device could not be developed using the existing GJPO liquid-scintillation counting system and a nontoxic counting medium. 10 refs., 10 figs., 10 tabs.

Spangler, R.R.; Langner, G.H., Jr.

1989-02-01

146

Physico-chemical characterization of steel slag. Study of its behavior under simulated environmental conditions.  

PubMed

The chemical and mineralogical composition of steel slag produced in two ArcelorMittal steel plants located in the North of Spain, as well as the study of the influence of simulated environmental conditions on the properties of the slag stored in disposal areas, was carried out by elemental chemical analysis, XRF, X-ray diffraction, thermal analysis, and scanning electron microscopy with EDS analyzer. Spectroscopic characterization of the slag was also performed by using FTIR spectroscopy. Due to the potential uses of the slag as low cost adsorbent for water treatment and pollutants removal, its detailed textural characterization was carried out by nitrogen adsorption-desorption at 77 K and mercury intrusion porosimetry. The results show that the slag is a crystalline heterogeneous material whose main components are iron oxides, calcium (magnesium) compounds (hydroxide, oxide, silicates, and carbonate), elemental iron, and quartz. The slags are porous materials with specific surface area of 11 m(2)g(-1), containing both mesopores and macropores. Slag exposure to simulated environmental conditions lead to the formation of carbonate phases. Carbonation reduces the leaching of alkaline earth elements as well as the release of the harmful trace elements Cr (VI) and V. Steel slags with high contents of portlandite and calcium silicates are potential raw materials for CO(2) long-term storage. PMID:20568743

Navarro, Carla; Díaz, Mario; Villa-García, María A

2010-07-15

147

The Role of Abiotic Environmental Conditions and Herbivory in Shaping Bacterial Community Composition in Floral Nectar  

PubMed Central

Identifying the processes that drive community assembly has long been a central theme in ecology. For microorganisms, a traditional prevailing hypothesis states that “everything is everywhere, but the environment selects”. Although the bacterial community in floral nectar may be affected by both atmosphere (air-borne bacteria) and animals as dispersal vectors, the environmental and geographic factors that shape microbial communities in floral nectar are unknown. We studied culturable bacterial communities in Asphodelus aestivus floral nectar and in its typical herbivorous bug Capsodes infuscatus, along an aridity gradient. Bacteria were sampled from floral nectar and bugs at four sites, spanning a geographical range of 200 km from Mediterranean to semi-arid conditions, under open and bagged flower treatments. In agreement with the niche assembly hypothesis, the differences in bacterial community compositions were explained by differences in abiotic environmental conditions. These results suggest that microbial model systems are useful for addressing macro-ecological questions. In addition, similar bacterial communities were found in the nectar and on the surface of the bugs that were documented visiting the flowers. These similarities imply that floral nectar bacteria dispersal is shaped not only by air borne bacteria and nectar consumers as previously reported, but also by visiting vectors like the mirid bugs. PMID:24922317

Samuni-Blank, Michal; Izhaki, Ido; Laviad, Sivan; Bar-Massada, Avi; Gerchman, Yoram; Halpern, Malka

2014-01-01

148

Manipulating individual state during migration provides evidence for carry-over effects modulated by environmental conditions  

PubMed Central

Despite observational evidence of carry-over effects (COEs, events occurring in one season that produce residual effects on individuals the following seasons), to our knowledge no experimental studies have been carried out to explore how COEs might affect reproductive output. We simulated an environmental perturbation affecting spring-staging migrants to investigate COEs in greater snow geese (Anser caerulescens atlanticus). During three consecutive years, 2037 females captured during spring staging (approx. 3000 km south of their Arctic breeding grounds) were maintained in captivity (with or without access to food) for 0–4 days. Duration of captivity (but not food treatment) negatively affected reproductive success, probably through stress response. Reproductive success was reduced by 45–71% in 2 years, but not in a third year with unusually favourable breeding conditions. This unprecedented manipulation indicates that COEs can have a strong effect on individual reproductive success in long-distance migrants, but that this effect can be partly compensated for by good environmental conditions on the breeding ground. PMID:21865256

Legagneux, Pierre; Fast, Peter L. F.; Gauthier, Gilles; Bêty, Joël

2012-01-01

149

Environmental conditions and human drivers for changes to north Ethiopian mountain landscapes over 145 years.  

PubMed

As quantitative or spatially distributed studies of environmental change over truly long-term periods of more than 100 years are extremely rare, we re-photographed 361 landscapes that appear on historical photographs (1868-1994) within a 40,000 km(2) study area in northern Ethiopia. Visible evidence of environmental changes apparent from the paired photographs was analyzed using an expert rating system. The conditions of the woody vegetation, soil and water conservation structures and land management were worse in the earlier periods compared to their present conditions. The cover by indigenous trees is a notable exception: it peaked in the 1930s, declined afterwards and then achieved a second peak in the early 21st century. Particularly in areas with greater population densities, there has been a significant increase in woody vegetation and soil and water conservation structures over the course of the study period. We conclude that except for an apparent upward movement of the upper tree limit, the direct human impacts on the environment are overriding the effects of climate change in the north Ethiopian highlands and that the northern Ethiopian highlands are currently greener than at any other time in the last 145 years. PMID:24717722

Nyssen, Jan; Frankl, Amaury; Haile, Mitiku; Hurni, Hans; Descheemaeker, Katrien; Crummey, Donald; Ritler, Alfons; Portner, Brigitte; Nievergelt, Bernhard; Moeyersons, Jan; Munro, Neil; Deckers, Jozef; Billi, Paolo; Poesen, Jean

2014-07-01

150

Assessing income-wise household environmental conditions and disease profile in urban areas: Study of an Indian city  

Microsoft Academic Search

The main objectives of the present study are: (i) to assess the income-wise household environmental conditions of the sampled\\u000a households in Aligarh city, (ii) to examine income-wise disease profile of the population, (iii) to assess the relationship\\u000a between income and four most occurring diseases, (iv) draw out inter-relationship between income, non-ideal household environmental\\u000a conditions and environment related diseases. The quality

Atiqur Rahman

2006-01-01

151

Transcriptional response of the model planctomycete Rhodopirellula baltica SH1T to changing environmental conditions  

PubMed Central

Background The marine model organism Rhodopirellula baltica SH1T was the first Planctomycete to have its genome completely sequenced. The genome analysis predicted a complex lifestyle and a variety of genetic opportunities to adapt to the marine environment. Its adaptation to environmental stressors was studied by transcriptional profiling using a whole genome microarray. Results Stress responses to salinity and temperature shifts were monitored in time series experiments. Chemostat cultures grown in mineral medium at 28°C were compared to cultures that were shifted to either elevated (37°C) or reduced (6°C) temperatures as well as high salinity (59.5‰) and observed over 300 min. Heat shock showed the induction of several known chaperone genes. Cold shock altered the expression of genes in lipid metabolism and stress proteins. High salinity resulted in the modulation of genes coding for compatible solutes, ion transporters and morphology. In summary, over 3000 of the 7325 genes were affected by temperature and/or salinity changes. Conclusion Transcriptional profiling confirmed that R. baltica is highly responsive to its environment. The distinct responses identified here have provided new insights into the complex adaptation machinery of this environmentally relevant marine bacterium. Our transcriptome study and previous proteome data suggest a set of genes of unknown functions that are most probably involved in the global stress response. This work lays the foundation for further bioinformatic and genetic studies which will lead to a comprehensive understanding of the biology of a marine Planctomycete. PMID:19725962

Wecker, Patricia; Klockow, Christine; Ellrott, Andreas; Quast, Christian; Langhammer, Philipp; Harder, Jens; Glöckner, Frank Oliver

2009-01-01

152

Sudden changes in environmental conditions do not increase invasion risk in grassland  

NASA Astrophysics Data System (ADS)

After direct habitat transformation, biological invasions are considered to be the second most important threat to biodiversity. A better understanding of the factors affecting invasion success in new areas is crucial, and may provide insight into potential control actions. We hypothesized that invasion risk increases in habitats undergoing a sudden change in the disturbance regime or environmental conditions. For testing this assumption we initiated a seed sowing experiment while introducing two novel treatments, mowing twice and fertilizer application, in two grassland sites (one dryer and one mesic) in Romania. The seeds of two invasive species, Solidago canadensis and Rudbeckia laciniata, and two resident natives of similar seed sizes, life-forms and strategies were sowed in treated and control plots, and seed germination, seedling establishment and growth were followed during four months. Contrary to our expectations, there was no difference in the treatment effects on seed germination and seedling establishment between species, while there was on seedling vigour of the larger seeded species in the dryer grassland site, where the native had a higher performance especially in increased nutrient conditions. Indifferently from applied treatments, invasive species had greater cumulative germination in the mesic site, while natives were far more successful in seedling establishment in the drier site. At the same time, seed size was found to be a very important factor explaining germination and establishment success, with large seeded species outperforming small seeded species in any circumstances. Our results call the attention upon management interventions in mesic, productive grassland sites opening colonization windows for the recruitment of those invasive species of which ecological requirements correspond to local environmental conditions.

Ruprecht, Eszter; Fenesi, Annamária; Nijs, Ivan

2013-02-01

153

Major methodological constraints to the assessment of environmental status based on the condition of benthic communities  

NASA Astrophysics Data System (ADS)

The Marine Strategy Framework Directive (MSFD) was published in 2008 and requires Member States to take the necessary measures to achieve or maintain good environmental status in aquatic ecosystems by the year of 2020. The MSFD indicates 11 qualitative descriptors for environmental status assessment, including seafloor integrity, using the condition of the benthic community as an assessment indicator. Member States will have to define monitoring programs for each of the MSFD descriptors based on those indicators in order to understand which areas are in a Good Environmental Status and what measures need to be implemented to improve the status of areas that fail to achieve that major objective. Coastal and offshore marine waters are not frequently monitored in Portugal and assessment tools have only been developed very recently with the implementation of the Water Framework Directive (WFD). The lack of historical data and knowledge on the constraints of benthic indicators in coastal areas requires the development of specific studies addressing this issue. The major objective of the current study was to develop and test and experimental design to assess impacts of offshore projects. The experimental design consisted on the seasonal and interannual assessment of benthic invertebrate communities in the area of future implementation of the structures (impact) and two potential control areas 2 km from the impact area. Seasonal benthic samples were collected at nine random locations within the impact and control areas in two consecutive years. Metrics included in the Portuguese benthic assessment tool (P-BAT) were calculated since this multimetric tool was proposed for the assessment of the ecological status in Portuguese coastal areas under the WFD. Results indicated a high taxonomic richness in this coastal area and no significant differences were found between impact and control areas, indicating the feasibility of establishing adequate control areas in marine ecosystems. Nevertheless, significant differences were found between different seasons and different years, showing that the coastal benthic communities important temporal variations. Although those variations did not affect the status assessment based on metrics that considered the ratio between sensitive and tolerant taxa, diversity indices showed different classifications between seasons and years. These results indicate the need for a temporal stratification of the monitoring programs. That might be achieved by setting different thresholds for specific seasons or selecting specific monitoring seasons. It might also require a regular assessment of the environmental conditions that support the identification of outlier years, which monitoring results should be carefully considered.

Medeiros, João Paulo; Pinto, Vanessa; Sá, Erica; Silva, Gilda; Azeda, Carla; Pereira, Tadeu; Quintella, Bernardo; Raposo de Almeida, Pedro; Lino Costa, José; José Costa, Maria; Chainho, Paula

2014-05-01

154

Relationship between environmental conditions and rates of coastal erosion in Arctic Alaska  

NASA Astrophysics Data System (ADS)

Rates of coastal cliff erosion are a function of the geometry and substrate of the coast; storm frequency, duration, magnitude, and wave field; and regional sediment sources. In the Arctic, the duration of sea ice-free conditions limits the time over which coastal erosion can occur, and sea water temperature modulates erosion rates where ice content of coastal bluffs is high. Predicting how coastal erosion rates in this environment will respond to future climate change requires that we first understand modern coastal erosion rates. Arctic coastlines are responding rapidly to climate change. Remotely sensed observations of coastline position indicate that the mean annual erosion rate along a 60-km reach of Alaska's Beaufort Sea coast, characterized by high ice content and small grain size, doubled from 7 m yr-1 for the period 1955-1979 to 14 m yr-1 for 2002-2007. Over the last 30 years the duration of the open water season expanded from ?45 days to ?95 days, increasing exposure of permafrost bluffs to seawater by a factor of 2.5. Time-lapse photography indicates that coastal erosion in this environment is a halting process: most significant erosion occurs during storm events in which local water level is elevated by surge, during which instantaneous submarine erosion rates can reach 1-2 m/day. In contrast, at times of low water, or when sea ice is present, erosion rates are negligible. We employ a 1D coastal cross-section numerical model of the erosion of ice-rich permafrost bluffs to explore the sensitivity of the system to environmental drivers. Our model captures the geometry and style of coastal erosion observed near Drew Point, Alaska, including insertion of a melt-notch, topple of ice-wedge-bounded blocks, and subsequent degradation of these blocks. Using consistent rules, we test our model against the temporal pattern of coastal erosion over two periods: the recent past (~30 years), and a short (~2 week) period in summer 2010. Environmental conditions used to drive model runs for the summer of 2010 include ground-based measurements of meteorological conditions (air temperature, wind speed, wind direction) and coastal waters (water level, wave field, water temperature), supplemented by high temporal frequency (4 frames/hour) time-lapse photography of the coast. Reconstruction of the 30-year coastal erosion history is accomplished by assembling published observations and records of meteorology and sea ice conditions, including both ground and satellite-based records, to construct histories of coastline position and environmental conditions. We model wind-driven water level set-up, the local wave field, and water temperature, and find a good match against the short-term erosion record. We then evaluate which environmental drivers are most significant in controlling the rates of coastal erosion, and which melt-erosion rule best captures the coastal history, with a series of sensitivity analyses. The understanding gained from these analyses provides a foundation for evaluating how continuing climate change may influence future coastal erosion rates in the Arctic.

Barnhart, K. R.; Anderson, R. S.; Overeem, I.; Wobus, C. W.; Clow, G. D.; Urban, F. E.; LeWinter, A. L.; Stanton, T. P.

2012-12-01

155

Impact of environmental production conditions on productivity and efficiency: a case study of wheat farmers in Bangladesh.  

PubMed

Environmental conditions significantly affect production, but are often ignored in studies analysing productivity and efficiency leading to biased results. In this study, we examine the influence of selected environmental factors on productivity and efficiency in wheat farming in Bangladesh. Results reveal that environmental production conditions significantly affect the parameters of the production function and technical efficiency, as well as correlates of inefficiency. Controlling for environmental production conditions improves technical efficiency by 4 points (p<0.01) from 86% to 90%. Large farms are more efficient relative to small and medium sized farms (p<0.01 and 0.05), with no variation among regions. Policy implications include soil fertility improvement through soil conservation and crop rotation, improvement in managerial practices through extension services and adoption of modern technologies, promotion of education, strengthening the research-extension link, and development of new varieties that have higher yield potential and are also suitable for marginal areas. PMID:17764818

Rahman, Sanzidur; Hasan, M Kamrul

2008-09-01

156

Raman spectroscopy of a single living cell in environmentally stressed conditions  

NASA Astrophysics Data System (ADS)

Living cells initiate a stress response in order to survive environmentally stressful conditions. We monitored changes in the Raman spectra of an optically trapped Saccharomyces cerevisiae yeast cell under normal and hyperosmotic stress conditions. When the yeast cells were challenged with a high concentration of glucose so as to exert hyperosmotic stress, it was shown that two chemical substances - glycerol and ethanol - could be monitored in real time in a single cell. The volume of the detection area of our confocal microspectrometer is approximately 1 fL. The average quantities of detected glycerol and ethanol are about 300 attomol and 700 attomol respectively. This amounts to the detection of approximately 108 glycerol molecules and 4 X 108 ethanol molecules after 36 min of hyper osmotic stress. Besides this, we also optically trapped a single yeast cell for up to three hours under normal conditions and monitored the changes in the Raman spectra during the lag phase of its growth and the G1 phase of its cell cycle. During the lag phase the cell synthesises new proteins and the observed behavior of the peaks corresponding to these proteins as well as those of RNA served as a sensitive indicator of the adaptation of the cell to its changed environment. The changes observed in the Raman spectra of a trapped yeast cell in the late G1 phase or the beginning of S phase corresponded to the growth of a bud.

Singh, Gajendra P.; Creely, Caitriona; Volpe, Giovanni; Grotsch, Helga; Petrov, Dmitri

2005-08-01

157

An analysis of sensible respiratory heat exchange during inspiration under environmental conditions of deep diving.  

PubMed

Temperature of the gas stream and mucosa were measured in the upper and lower trachea and right and left main bronchi of several anesthetized, intubated and mechanically respired mongrel dogs. Airway temperatures were measured using an airway sensor probe instrumented with microthermistors. Each thermistor was integrated into an especially designed. Wheatstone bridge whose signal of millivolts was displayed on a calibrated polygraph recorder. Diving respiratory conditions were simulated by utilization of an appropriate ventilatory periodic flow through an endotracheal airway which by-passed the efficient gas conditioning nasal turbinates of the dog. Deep diving respiratory environmental conditions of gas temperature, density and thermal capacitance (?Cp) were simulated in a hyperbaric chamber. The temperatures recorded during in vivo periodic positive pressure ventilation were applied to a quasi-steady flow model based upon the morphological dimensions of the Weibel model. An empirical mathematical model of inspiratory sensible heat loss was verified and slightly modified to better reflect the overall dimensionless heat transfer relationship Nu = 0.302 (RePr)0.786 that existed in the major bronchial airways of the experimental subject. The design of the experimental instrumentation is explained in detail, as is the basic mathematical model. Significance of the experimental findings is discussed. PMID:23719717

Johnson, C E; Linderoth, L S; Nuckols, M L

1977-02-01

158

Embryo transcriptome response to environmental factors: implication for its survival under suboptimal conditions.  

PubMed

After its formation, the mammalian zygote undergoes a series of morphological, physiological and biochemical alterations prior to undergoing cell differentiation. The zygote is then transformed into a complex multicellular organism in a defined time window which may differ between species. These orderly embryonic developmental events are tightly regulated by temporal and spatial activation and/or deactivation of genes and gene products. This phenomenon may in turn be dependent on the intrinsic characteristics of the embryo itself, the physiological and biochemical composition of the maternal environment or by in vitro culture condition. In fact, when embryos are subjected to suboptimal culture condition, some of the embryos may escape the environmental stress by activating certain transcripts and some others which are unable to activate anti-stress agents may die or exhibit abnormal development. This phenomenon may partly depend on transcripts and proteins stored during oogenesis. Indeed after embryonic genome activation, the embryo destiny is governed by its own transcripts and protein synthesized over time. Therefore, this review begins by highlighting the type and quality of transcripts accumulated or degraded during oogenesis and its impact on the embryo survival. Thereafter, emphasis is given to the transcriptome response of preimplantation embryos to suboptimal culture conditions. In addition, the long term effect of preimplantation culture environment on the transcriptome response embryos/fetus during peri and post implantation has been addressed. Finally, a brief summary of the epigenetic control of culture induced genetic variation of the embryos has been highlighted. PMID:24972951

Salilew-Wondim, Dessie; Tesfaye, Dawit; Hoelker, Michael; Schellander, Karl

2014-09-01

159

Impaired multisensory processing in schizophrenia: Deficits in the visual enhancement of speech comprehension under noisy environmental conditions  

Microsoft Academic Search

BackgroundViewing a speaker's articulatory movements substantially improves a listener's ability to understand spoken words, especially under noisy environmental conditions. In this study we investigated the ability of patients with schizophrenia to integrate visual and auditory speech. Our objective was to determine to what extent they experience benefit from visual articulation and to detail under what listening conditions they might show

Lars A. Ross; Dave Saint-Amour; Victoria M. Leavitt; Sophie Molholm; Daniel C. Javitt; John J. Foxe

2007-01-01

160

Compensating method for measuring carbon dioxide exchange, transpiration, and diffusive resistances of plants under controlled environmental conditions  

Microsoft Academic Search

A semi-closed compensating system is described for measuring COâ exchange and transpiration simultaneously under controlled environmental conditions. The compensating feature permits conditions in the assimilation chamber to be kept uniform and within narrow limits. Temperature, relative humidity, carbon dioxide concentration, wind speed, and light intensity may be varied within the system. Since transpiration and photosynthesis can be measured simultaneously, diffusive

F. A. Bazzaz; J. S. Boyer

2009-01-01

161

Staphylococcus aureus metabolic response to changing environmental conditions - a metabolomics perspective.  

PubMed

Microorganisms preserve their metabolic function against a wide range of external perturbations including biotic or abiotic factors by utilizing cellular adaptations to maintain cell homeostasis. Functional genomics aims to detect such adaptive alterations on the level of transcriptome, proteome and metabolome to understand system wide changes and to identify interactions between the different levels of biochemical organization. Microbial metabolomics measures metabolites, the direct biochemical response to the environment, and is pivotal to the understanding of the variability and dynamics of bacterial cell metabolism. Metabolomics can measure many different types of compounds including primary metabolites, secondary metabolites, second messengers, quorum sensing compounds and others, which all contribute to the complex bacterial response to an environmental change. Recent data confirmed that many metabolic processes in pathogenic bacteria are linked to virulence and invasive capabilities. Deciphering bacterial metabolism in response to specific environmental conditions and in specific genetic backgrounds will help map the complex network between the metabolome and the other "-omes". Here, we will review a selection of case studies for the pathogenic Gram-positive bacterium Staphylococcus aureus and summarize the current state of metabolomics literature covering staphylococci metabolism under different physiological states. PMID:24439195

Liebeke, Manuel; Lalk, Michael

2014-05-01

162

Food for thought: Conditions for discourse reflection in the light of environmental assessment  

SciTech Connect

People tend to take notice of what is happening around them selectively. Discourses-frames through which actors give meaning to aspects of the world-act as built-in filters that distinguish relevant from irrelevant data. Use of knowledge generated by environmental assessments (EAs) in decision-making may be understood from this perspective. Environmental knowledge that is inconsistent with dominant discourses runs the risk of being ignored. Discourses on the value of EA as a tool for decision-making may have a similar effect. Stimulating decision-makers and stakeholders to critically reflect on and reconsider their discourses in the light of EAs-also known as frame reflection or policy learning-may enhance the probability that these assessments and the knowledge that they generate impact upon decision-making. Up to now little has been written about how discourse reflection in the context of EA can be promoted. Valuable inputs are fragmented over different bodies of literature. In this paper we draw from these bodies to identify favourable conditions for discourse reflection.

Runhaar, Hens, E-mail: h.runhaar@geo.uu.n [Copernicus Institute for Sustainable Development and Innovation, Utrecht University, P.O. Box 80, 115, 3508 TC Utrecht (Netherlands); Runhaar, Piety R., E-mail: p.r.honnef-runhaar@gw.utwente.n [Organisational Psychology and Human Resource Development, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Oegema, Tammo, E-mail: tammo.oegema@imsa.n [IMSA Amsterdam, Prins Hendriklaan 15, 1075 AX Amsterdam (Netherlands)

2010-11-15

163

Evidence for the role of environmental agents in the initiation or progression of autoimmune conditions.  

PubMed Central

The concordance of autoimmune disease among identical twins is virtually always less than 50% and often in the 25-40% range. This observation, as well as epidemic clustering of some autoimmune diseases following xenobiotic exposure, reinforces the thesis that autoimmune disease is secondary to both genetic and environmental factors. Because nonliving agents do not have genomes, disease characteristics involving nonliving xenobiotics are primarily secondary to host phenotype and function. In addition, because of individual genetic susceptibilities based not only on major histocompatibility complex differences but also on differences in toxin metabolism, lifestyles, and exposure rates, individuals will react differently to the same chemicals. With these comments in mind it is important to note that there have been associations of a number of xenobiotics with human autoimmune disease, including mercury, iodine, vinyl chloride, canavanine, organic solvents, silica, l-tryptophan, particulates, ultraviolet radiation, and ozone. In addition, there is discussion in the literature that raises the possibility that xenobiotics may also exacerbate an existing autoimmune disease. In this article we discuss these issues and, in particular, the evidence for the role of environmental agents in the initiation or progression of autoimmune conditions. With the worldwide deterioration of the environment, this is a particularly important subject for human health. PMID:10970167

Powell, J J; Van de Water, J; Gershwin, M E

1999-01-01

164

Plant response to environmental conditions: assessing potential production, water demand, and negative effects of water deficit  

PubMed Central

This paper reviews methods for analyzing plant performance and its genetic variability under a range of environmental conditions. Biomass accumulation is linked every day to available light in the photosynthetically active radiation (PAR) domain, multiplied by the proportion of light intercepted by plants and by the radiation use efficiency. Total biomass is cumulated over the duration of the considered phase (e.g., plant cycle or vegetative phase). These durations are essentially constant for a given genotype provided that time is corrected for temperature (thermal time). Several ways of expressing thermal time are reviewed. Two alternative equations are presented, based either on the effect of transpiration, or on yield components. Their comparative interests and drawbacks are discussed. The genetic variability of each term of considered equations affects yield under water deficit, via mechanisms at different scales of plant organization and time. The effect of any physiological mechanism on yield of stressed plants acts via one of these terms, although the link is not always straightforward. Finally, I propose practical ways to compare the productivity of genotypes in field environments, and a “minimum dataset” of environmental data and traits that should be recorded for that. PMID:23423357

Tardieu, François

2013-01-01

165

Species Diversity Improves the Efficiency of Mercury-Reducing Biofilms under Changing Environmental Conditions  

PubMed Central

Six mercury-resistant environmental proteobacterial isolates and one genetically modified mercury-resistant Pseudomonas putida strain were analyzed for physiological traits of adaptive relevance in an environment of packed-bed bioreactors designed for the decontamination of mercury-polluted chlor-alkali wastewater. The strains displayed characteristic differences in each trait (i.e., biofilm formation capability, growth rate in mercury contaminated wastewaters, and mercury reduction efficiency). Subsequently, they were immobilized either as a monoculture or as a mixed culture on porous carrier material in packed-bed bioreactors through which different batches of filter-sterilized industrial chlor-alkali wastewater were pumped. In monospecies bioreactors, the mercury retention efficiency was sensitive to rapidly increasing mercury concentrations in the wastewater. Mixed culture biofilms displayed a high mercury retention efficiency that was not affected by rapid increases in mercury or continuously high mercury concentrations. The dynamic in the community composition of the mixed culture bioreactors was determined by ribosomal intergenic spacer polymorphism analysis. Mercury-mediated selective pressure decreased the number of prevalent strains. Microbial diversity was completely restored after easing of the selective pressure. Microbial diversity provides a reservoir of strains with complementary ecological niches that results in a superior bioreactor performance under changing environmental conditions. PMID:12039739

von Canstein, Harald; Kelly, Sven; Li, Ying; Wagner-Döbler, Irene

2002-01-01

166

Dry Soils: The Highlands of the Antarctic Dry Valleys and the Defining Environmental Conditions  

NASA Astrophysics Data System (ADS)

The cases explored are those of ice-cemented ground to the surface. We ask the question: under what environmental conditions does ice-cemented ground at the surface not melt? We find that in all cases, keeping the surface frozen requires that the air temperature does not exceed freezing. In addition, we find that the wind velocity plays an important role. The wind acts as a coupling between the atmosphere and the ground, thus with increasing wind velocity the ground temperature becomes increasingly similar to the air temperature. This also results in an increased sublimation rate from the ground, as vapour is quickly moved into the dry atmosphere. In cases where the wind velocity is very low, the ground surface can become very warm even with air temperatures which are significantly below freezing. Changes in the atmospheric relative humidity play a minor role, with lower humidities resulting in increased cooling of the ground by sublimation, and thus slightly lower ground temperatures.

Marinova, M. M.; McKay, C. P.; Heldmann, J. L.; Davila, A. F.; Andersen, D. T.; Jackson, W. A.; Lacelle, D.; Paulson, G.; Pollard, W. H.; Zacny, K.

2011-10-01

167

Maternal sex effects and inbreeding depression under varied environmental conditions in gynodioecious Fragaria vesca subsp. bracteata  

PubMed Central

Background and Aims Gynodioecy (coexistence of females and hermaphrodites) is a sexual system that occurs in numerous flowering plant lineages. Thus, understanding the features that affect its maintenance has wide importance. Models predict that females must have a seed fitness advantage over hermaphrodites, and this may be achieved via seed quality or quantity. Females in a population of Fragaria vesca subsp. bracteata, a long-lived gynodioecious perennial, do not demonstrate a seed quantity advantage, so this study explored whether females produced better quality seed via maternal sex effects or avoidance of inbreeding depression (IBD). Methods Families of selfed and outcrossed seed were created using hermaphrodite mothers and families of outcrossed seed were created using female mothers. The effects of these pollination treatments were assessed under benign conditions early in life and under varied conditions later in life. To test for an effect of maternal sex, fitness components and traits associated with acclimation to variable environments of progeny of outbred hermaphrodites and females were compared. To test for expression of IBD, fitness parameters between inbred and outbred progeny of hermaphrodites were compared. Key Results Offspring of females were more likely to germinate in benign conditions and survive in harsh resource environments than outbred progeny of hermaphrodites. IBD was low across most life stages, and both the effect of maternal sex on progeny quality and the expression of IBD depended on both maternal family and resource condition of the progeny. Conclusions The effect of maternal sex and IBD on progeny quality depended on resource conditions, maternal lineage and progeny life stage. In conjunction with known lack of differences in seed quantity, the quality advantages and IBD observed here are still unlikely to be sufficient for maintenance of gynodioecy under nuclear inheritance of male sterility. PMID:23723257

Dalton, Rebecca M.; Koski, Matthew H.; Ashman, Tia-Lynn

2013-01-01

168

Revegetation processes and environmental conditions in abandoned peat production fields in Estonia  

NASA Astrophysics Data System (ADS)

As a result of peat extraction, peat production has been finished in Estonia at different times in 154 peat production areas and 9,500 ha (~1% of peatlands) are abandoned, although the peat reserves are not exhausted yet; besides, several areas are not properly recultivated. In addition 12,000 ha of fens (oligotrophic peat layers) are drained and used as grasslands. If the abandoned and non-recultivated peat production areas are not vegetated, their CO2 emission is considerable and peat mineralises in such areas. The aim of the study was to find out specific ecological and geological factors, which affect recovering of peatlands and influence the recultivation. During the revision the amount and quality of the remained reserves, as well as the state of water regime, drainage network and revegetation was assessed in all 154 abandoned peat production areas. The study showed that the state of them is very variable. Some of them are covered with forest, prevailingly with birches at former drainage ditches, later supplemented by pine trees. In the others predominate grasses among plants, and various species of moss (Cladonia rei, Bryum caespiticum, Sphagnum ripariuma, Sphagnum squarrosum) occur as well. Besides, some abandoned areas are completely overgrown with cotton grass. Open abandoned peat areas, which are not covered by vegetation, are much rarer. We found out, that water regime among the factors plays most important role. Moreover abandoned peat production fields, where the environmental conditions have changed - are appropriate for growth of several moss species, which cannot inhabit the areas already occupied by other species. The most interesting discovers were: second growing site of Polia elongata in West-Estonia and Ephemerum serratum, last found in Estonia in the middle of the 19th century, was identified in central Estonia. Also Campylopus introflexus, what was unknown in Estonia. However, the changes in environmental conditions influence the peat layers structure and technical characteristics of organic soils that affect the vegetation of peatlands.

Orru, M.; Orru, H.

2009-04-01

169

The phycobilisome, a light-harvesting complex responsive to environmental conditions.  

PubMed Central

Photosynthetic organisms can acclimate to their environment by changing many cellular processes, including the biosynthesis of the photosynthetic apparatus. In this article we discuss the phycobilisome, the light-harvesting apparatus of cyanobacteria and red algae. Unlike most light-harvesting antenna complexes, the phycobilisome is not an integral membrane complex but is attached to the surface of the photosynthetic membranes. It is composed of both the pigmented phycobiliproteins and the nonpigmented linker polypeptides; the former are important for absorbing light energy, while the latter are important for stability and assembly of the complex. The composition of the phycobilisome is very sensitive to a number of different environmental factors. Some of the filamentous cyanobacteria can alter the composition of the phycobilisome in response to the prevalent wavelengths of light in the environment. This process, called complementary chromatic adaptation, allows these organisms to efficiently utilize available light energy to drive photosynthetic electron transport and CO2 fixation. Under conditions of macronutrient limitation, many cyanobacteria degrade their phycobilisomes in a rapid and orderly fashion. Since the phycobilisome is an abundant component of the cell, its degradation may provide a substantial amount of nitrogen to nitrogen-limited cells. Furthermore, degradation of the phycobilisome during nutrient-limited growth may prevent photodamage that would occur if the cells were to absorb light under conditions of metabolic arrest. The interplay of various environmental parameters in determining the number of phycobilisomes and their structural characteristics and the ways in which these parameters control phycobilisome biosynthesis are fertile areas for investigation. PMID:8246846

Grossman, A R; Schaefer, M R; Chiang, G G; Collier, J L

1993-01-01

170

Effects of sawdust thickness on the growth performance, environmental condition, and welfare quality of yellow broilers.  

PubMed

An experiment was conducted to evaluate the effect of litter thickness on growth performance, immune status, environmental condition, and welfare quality in yellow broilers. In total, 1,800 one-day-old Suqin yellow broilers were raised for 21 d. On d 22, 1,600 birds of similar BW (404 ± 12 g) were randomly selected and placed into 20 indoor pens (8 birds/m(2), 10 m(2)/pen). These birds were assigned to a litter treatment of 4, 8, 12, and 16 cm. Each treatment was repeated in five pens. The results showed that a thicker litter was related to increased BW, daily weight gain, and daily feed intake (P < 0.001). Feed conversion ratio and mortality were unaffected by litter thickness (P = 0.320, P = 0.353, respectively). Absolute and relative liver weights showed a significant linear response to increasing litter thickness (P = 0.01, P = 0.001, respectively). The litter moisture content, air ammonia, and CO2 content decreased, whereas the air dust content increased with increasing litter thickness (P < 0.001, P = 0.017, P = 0.033, P < 0.001, respectively). Litter thickness had no effect on gait, plumage damage, hock burn or breast skin crusting (P = 0.076, P = 0.964, P = 0.131, P = 0.401, respectively). Plumage cleanliness, foot pad dermatitis, hock swelling and breast blister varied significantly with litter thickness (P = 0.027, P = 0.011, P = 0.014, P = 0.042, respectively). The results of this study suggest that an increasing litter thickness has a beneficial effect on the growth performance, environmental condition and welfare of birds. PMID:25577790

Shao, Dan; He, Jiao; Lu, Jian; Wang, Qiang; Chang, Lingling; Shi, Shou Rong; Bing, Tong Hai

2015-01-01

171

Are spatial variations in the diets of hydrothermal fauna linked to local environmental conditions?  

NASA Astrophysics Data System (ADS)

Trophic relationships in Bathymodiolus azoricus mussel bed communities on the Tour Eiffel hydrothermal edifice (Lucky Strike) were assessed using ? 13C and ? 15N signatures from 14 hydrothermal species. The nutritional basis of B. azoricus was also investigated with ? 34S. Faunal samples and environmental data (temperature, pH, total dissolved sulfide, iron and copper concentrations) were collected from 12 different locations on the edifice. Chemical conditions varied between microhabitats, and were all correlated to temperature. Carbon and nitrogen isotopic results revealed the presence of two, apparently independent, trophic groups. The first was composed of symbiont-bearing fauna ( B. azoricus and their associated polychaetes Branchipolynoe seepensis), while the second enclosed heterotrophic fauna (bacterivores, detritivores, scavengers, predators). A majority of mussels displayed ? 13C values ranging from -27‰ to -34‰, supporting thiotrophy as the dominant nutritional pathway at Tour Eiffel, with methanotrophy and filter feeding emerging as secondary strategies. This result was corroborated by ? 34S signatures. However, higher ? 13C values in larger mussels suggested that, as they grow, B. azoricus mussels rely more heavily on their methanotrophic endosymbionts. Significant spatial variability in isotopic signatures for single faunal species was observed at the scale of the edifice for three species ( B. azoricus, B. seepensis, Amathys lutzi), and environmental conditions explained variation in isotopic signatures for one-third of the species. This confirms the hypothesis raised by several authors on the role of hydrothermal fluids on the trophic network at small spatial scales. We suggest that vent fluid characteristics, by influencing microbial production, are key factors in the variation of local carbon sources at vents.

De Busserolles, F.; Sarrazin, J.; Gauthier, O.; Gélinas, Y.; Fabri, M. C.; Sarradin, P. M.; Desbruyères, D.

2009-09-01

172

Perfluoroalkyl substance concentrations in a terrestrial raptor: Relationships to environmental conditions and individual traits.  

PubMed

Accumulation of persistent organic pollutants (POPs) in wildlife may be influenced by the physical and biotic environment, and concentrations vary greatly among areas, seasons, and individuals. Different hypotheses about sources of variation in perfluoroalkyl substance (PFAS) concentrations were examined in eggs (n?=?107) of tawny owls (Strix aluco) collected over a 24-yr period (1986-2009) in Norway. Predictor variables included the North Atlantic Oscillation (NAO), temperature, snow, food availability (vole abundance), and individual traits such as age, body condition, and clutch size. Concentrations of both perfluoro-octane sulfonate (PFOS) and perfluoroalkyl carboxylates (PFCAs) varied several fold in the population, both inter- and intra-annually. Moreover, individuals laid eggs with several times higher or lower PFAS concentrations within few years (1 yr-5 yr). After controlling for temporal trends (i.e., declining PFOS and increasing PFCA concentrations), both PFOS and PFCAs were positively associated to the winter NAO in the previous year (NAOy - 1 ), suggesting that atmospheric transport may be affecting the input of PFASs to the local ecosystem. Perfluoro-octane sulfonate was negatively related to temperature, but the pattern was complex as there was an interaction between temperature and the feeding conditions. The PFOS accumulation was highest in years with high vole abundance and low to medium temperatures. For PFCAs, there was an interaction between NAOy - 1 and feeding conditions, suggesting that strong air transport toward Norway and high consumption of voles led to a moderate increase in PFCA accumulation. The individual traits, however, had very little impact on the concentrations of PFASs in the eggs. The present study thus suggests that annual variation in environmental conditions influences the concentrations of PFASs in a terrestrial raptor such as the tawny owl. Environ Toxicol Chem 2015;34:184-191. © 2014 SETAC. PMID:25323676

Bustnes, Jan O; Bangjord, Georg; Ahrens, Lutz; Herzke, Dorte; Yoccoz, Nigel G

2015-01-01

173

Relationship between fumonisin production and FUM gene expression in Fusarium verticillioides under different environmental conditions.  

PubMed

Fusarium verticillioides is the main source of fumonisins, a group of mycotoxins that can contaminate maize-based food and feed and cause diseases in humans and animals. The study of the effect of different environmental conditions on toxin production should provide information that can be used to develop strategies to minimize the risk. This study analysed the effect of temperature (15°C-35°C), water activity (a(w): 0.999-0.93), salinity (0-125 g l(-1) NaCl) and pH (5-8) on the growth and production of fumonisins B(1) (FB1), B(2) (FB2) and B(3) (FB3) and the expression of FUM1 and FUM21 in F. verticillioides. The highest growth rate was measured at 25°C, a(w) of 0.998-0.99 and 0-25 g l(-1) of NaCl. Optimal conditions for fumonisin production were 30°C, a(w) of 0.99, 25 g l(-1) of NaCl and pH 5; nevertheless, the strain showed a good adaptability and was able to produce moderate levels of fumonisins under a wide range of conditions. Gene expression mirrored fumonisin production profile under all conditions with the exception of temperature: FUM1 and FUM21 expression was highest at 15°C, while maximum fumonisin production was at 30°C. These data indicate that a post-transcriptional regulation mechanism could account for the different optimal temperatures for FUM gene expression and fumonisin production. PMID:23167929

Fanelli, Francesca; Iversen, Anita; Logrieco, Antonio F; Mulè, Giuseppina

2013-01-01

174

Exploring the relationship between vegetation spectra and eco-geo-environmental conditions in karst region, Southwest China.  

PubMed

Remote sensing of local environmental conditions is not accessible if substrates are covered with vegetation. This study explored the relationship between vegetation spectra and karst eco-geo-environmental conditions. Hyperspectral remote sensing techniques showed that there were significant differences between spectral features of vegetation mainly distributed in karst and non-karst regions, and combination of 1,300- to 2,500-nm reflectance and 400- to 680-nm first-derivative spectra could delineate karst and non-karst vegetation groups. Canonical correspondence analysis (CCA) successfully assessed to what extent the variation of vegetation spectral features can be explained by associated eco-geo-environmental variables, and it was found that soil moisture and calcium carbonate contents had the most significant effects on vegetation spectral features in karst region. Our study indicates that vegetation spectra is tightly linked to eco-geo-environmental conditions and CCA is an effective means of studying the relationship between vegetation spectral features and eco-geo-environmental variables. Employing a combination of spectral and spatial analysis, it is anticipated that hyperspectral imagery can be used in interpreting or mapping eco-geo-environmental conditions covered with vegetation in karst region. PMID:19089594

Yue, Yuemin; Wang, Kelin; Zhang, Bing; Chen, Zhengchao; Jiao, Quanjun; Liu, Bo; Chen, Hongsong

2010-01-01

175

Rate constants and mechanisms for the crystallization of Al nano-goethite under environmentally relevant conditions  

NASA Astrophysics Data System (ADS)

Mobile inorganic and organic nanocolloidal particles originate-from and interact-with bulk solid phases in soil and sediment environments, and as such, they contribute to the dynamic properties of environmental systems. In particular, ferrihydrite and (nano)goethite are the most abundant of nanocolloidal Fe oxy(hydr)oxides in these environments. We therefore investigated the ferrihydrite to goethite phase transformation using experimental reaction conditions that mimicked environmental conditions where the formation of nanocolloidal Fe oxy(hydr)oxides may occur: slow titration of dilute solutions to pH 5 at 25 °C with and without 2 mol% Al. Subsequently, the rate constants from 54-d nano-goethite aging/crystallization experiments at 50 °C were determined using aliquots pulled for vibrational spectroscopy (including multivariate curve resolution, MCR, analyses of infrared spectra) and synchrotron-based X-ray diffraction (XRD). We also present a mechanistic model that accounts for the nano-goethite crystallization observed by the aforementioned techniques, and particle structural characteristics observed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). In contrast to the common assumption that metastable ferrihydrite precipitates first, before it transforms to goethite, the presence of characteristic infrared bands in freshly synthesized nanoparticle suspensions indicate goethite can precipitate directly from solution under environmentally relevant conditions: low Fe concentration, ambient temperature, and pH maintained at 5. However, the presence of 2 mol% Al prevented direct goethite precipitation. Rate constants obtained by fitting the contributions from the MCR-derived goethite-like component to the OH-stretching region were (7.4 ± 1.1) × 10-7 s-1 for 0% Al and (4.2 ± 0.4) × 10-7 s-1 for 2 mol% Al suspensions. Rate constants derived from intensities of OH-bending infrared vibrations (795 and 895 cm-1) showed similar values, within error, for both 0 and 2 mol% Al nanoparticle suspensions. Thus, the presence of 2 mol% Al decreased the rate constants determined from analyses of infrared OH-stretching and OH-bending vibrations by 43-57%. We postulate that dissolution re-precipitation reactions are accelerated in aggregate microenvironments by locally increased supersaturation, yielding the dominant mechanism for transformation of ferrihydrite to goethite and goethite crystal growth when bulk ion concentrations are low. Although we did observe growth of a population of prismatic goethite single crystals by TEM, there was more substantial growth of a population of polycrystalline goethite needles that appeared to retain some defects from a preceding aggregation step that we detected with DLS. Since the presence of Al hinders the dissolution of ferrihydrite, it too reduces the rate of crystallization to goethite and its crystal growth. As exemplified in this nano-particle crystallization study, the combination of advanced spectral-curve-resolution algorithms and sensitive and quantitative infrared sampling techniques opens future opportunities for the quantification of mineral phase dynamics in nanocolloidal suspensions, which is important for many aspects of environmental studies.

Bazilevskaya, Ekaterina; Archibald, Douglas D.; Martínez, Carmen Enid

2012-07-01

176

Migration path annotation: cross-continental study of migration-flight response to environmental conditions.  

PubMed

Understanding the movements of animals is pivotal for understanding their ecology and predicting their survival in the face of rapid global changes to climate, land use, and habitats, thus facilitating more effective habitat management. Migration by flying animals is an extreme form of movement that may be especially influenced by weather. With satellite telemetry studies, and the growing availability of information about the Earth's weather and land surface conditions, many data are collected that can advance our understanding about the mechanisms that shape migrations. We present the track annotation approach for movement data analysis using information about weather from the North American Reanalysis data set, a publicly available, regional, high-resolution model-observation hybrid product, and about topography, from a publicly available high-resolution digital elevation model (DEM). As a case study, we present the analysis of the response to environmental conditions in three contrasting populations of Turkey Vultures (Cathartes aura) across North America, tracked with a three-dimensional GPS-based sensor. Two populations in the east and west coasts of the United States responded similarly to weather, indicating use of both slope and thermal soaring. Continental-interior, "Plains populations," exhibited a different migratory pattern primarily indicative of thermal soaring. These differences help us understand the constraints and behaviors of soaring migrants. The track annotation approach allowed large-scale comparative study of movement in an important migratory species, and will enable similar studies at local to global scales. PMID:21939059

Mandel, James T; Bohrer, Gil; Winkler, David W; Barber, David R; Houston, C Stuart; Bildstein, Keith L

2011-09-01

177

The Effects of Varying Environmental Conditions on the Emission Spectra of Meteorites  

NASA Astrophysics Data System (ADS)

With NASA's OSIRIS-REx mission due to launch to asteroid 101955 Bennu (previously known as 1999 RQ36) in 2016, preparations are well underway [4]. Once there, the OTES (OSIRIS-Rex Thermal Emission Spectrometer) instrument will map the asteroid's surface to derive thermal and compositional properties [4], by comparing spectra to those of known samples measured in the laboratory. Previous studies have shown that samples can exhibit differen ces in emission spectra due to composition, grain size and the environmental conditions in which they are measured [3,5,7], however the magnitude of these variations for asteroidal material require more study. The aim of this work is to determine whether laboratory samples need to be measured in a thermal environment like that on the asteroid's surface for correct interpretation of returning data from OTES: to do this, the Lunar Environment Chamber in the Planetary Spectroscopy Facility at Oxford University [7] was used to simulate the expected conditions on Bennu while a selection of ground meteorite samples were measured.

Thomas, I. R.; Bowles, N. E.; Connolly, H. C.; Kilgore, M.; Lauretta, D. S.

2013-09-01

178

Benefits of environmental conditions for growing coriander in Banat Region, Serbia.  

PubMed

As one of the oldest multi-purpose plants (spice, aromatic, honey and medicinal), coriander is widespread across Europe. Although in Serbia there are favorable conditions for its growth and development, it is grown on relatively small areas. During both investigated years it took more than 1200 degrees C for transfer from vegetative to generative phase of development and over 2000 degrees C for it to be ready for harvesting. Coriander is a photophilic plant, which requires around 1000 hours of light from sowing to ripening.. As for humidity, coriander grows well, if there are more than 200 mm of rainfall during growing season. In 2009 and 2010, the experiment carried out at the experimental field in Ostoji?evo (Banat, Vojvodina province, Serbia) monitored the effect of parameters mentioned above on development of coriander plants, seed yield and essential oil content. The average yields of 1866 kg ha(-1) (2009) and 2470 kg ha(-1) (2010), and relatively high content of essential oil (1.06% in both years) indicate a great potential of this plant species in Serbia, which is, however, greatly dependent on environmental conditions during year. PMID:22164784

Acimovic, Milica; Oljaca, Snezana; Jacimovic, Goran; Drazic, Slobodan; Tasic, Slavoljub

2011-10-01

179

Environmental effects on grass-endophyte associations in the harsh conditions of south Patagonia.  

PubMed

Cool-season grasses are frequently infected by Neotyphodium endophytes and this association is often considered as a mutualistic symbiosis. We examined the incidence of Neotyphodium in populations of Bromus setifolius, Phleum alpinum and Poa spiciformis, native and wide-spread grasses from south Patagonia, Argentina. The incidence of 36 populations of Bromus setifolius was studied in association with climatic and soil variables. 31 populations of Ph. alpinum were sampled in five different plant communities. Seventeen populations of P. spiciformis were sampled in three different plant communities. The association between incidence and climatic variables in Ph. alpinum and between incidence and soil fertility in P. spiciformis was investigated. In B. setifolius endophyte incidence was positively correlated with annual average rainfall contrary to the results found in Ph. alpinum. All the populations of P. spiciformis were infected by endophytes and the incidence was associated with plant community. The Neotyphodium-grass interaction is variable in natural populations, supporting the increasing evidence that the Neotyphodium-host interaction depends, in many cases, on the environmental conditions. Field observations suggest that in detrimental low growth conditions the association is not favoured, leading to a decrease in the endophyte frequency of infection or even to the complete loss of the association. PMID:17466027

Novas, M Victoria; Collantes, Marta; Cabral, Daniel

2007-07-01

180

Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic  

NASA Astrophysics Data System (ADS)

The Cape Lookout cold-water coral area off the coast of North Carolina forms the shallowest and northernmost cold-water coral mound area on the Blake Plateau in the NW Atlantic. Cold-water coral habitats near Cape Lookout are occasionally bathed in the Gulf Stream, which is characterised by oligotrophic warm water and strong surface currents. Here, we present the first insights into the mound distribution and morphology, sedimentary environment and coral cover and near-bed environmental conditions as recorded by bottom landers from this coral area. The mounds occur between 320 and 550 m water depth and are characterised by high acoustic backscatter indicating the presence of hard structure. Three distinct mound morphologies were observed: (1) a mound with a flattened top at 320 m, (2) multi-summited mounds with a teardrop shape in the middle part of the area and (3) a single mound at 540 m water depth. Echosounder profiles show the presence of a strong reflector underneath all mound structures that forms the base of the mounds. This reflector cropped out at the downstream side of the single mound and consists of carbonate slabs. Video analysis revealed that all mounds are covered by Lophelia pertusa and that living colonies only occur close to the summits of the SSW side of the mounds, which is the side that faces the strongest currents. Off-mound areas were characterised by low backscatter and sediment ripples, indicating the presence of relatively strong bottom currents. Two bottom landers were deployed amidst the coral mounds between December 2009 and May 2010. Both landers recorded prominent events, characterised by large fluctuations in environmental conditions near the seabed as well as in the overlying water column. The period between December and April was characterised by several events of increasing temperature and salinity, coinciding with increased flow and near-bed acoustic backscatter. During these events temperature fluctuated by up to 9 °C within a day, which is the largest temperature variability as measured so far in a cold-water coral habitat. Warm events, related to Gulf Stream meanders, had the duration of roughly 1 week and the current during these events was directed to the NNE. The consequences of such events must be significant given the strong effects of temperature on the metabolism of cold-water corals. Furthermore, elevated acoustic backscatter values and high mass fluxes were also recorded during these events, indicating a second stressor that may affect the corals. The abrasive nature of sand in combination with strong currents might sand blast the corals. We conclude that cold-water corals near Cape Lookout live under extreme conditions that limit mound growth at present.

Mienis, F.; Duineveld, G. C. A.; Davies, A. J.; Lavaleye, M. M. S.; Ross, S. W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M. J. N.; de Haas, H.; Brooke, S.; van Weering, T. C. E.

2014-05-01

181

Defining Life: Synthesis and Conclusions  

NASA Astrophysics Data System (ADS)

The first part of the paper offers philosophical landmarks on the general issue of defining life. §1 defends that the recognition of “life” has always been and remains primarily an intuitive process, for the scientist as for the layperson. However we should not expect, then, to be able to draw a definition from this original experience, because our cognitive apparatus has not been primarily designed for this. §2 is about definitions in general. Two kinds of definition should be carefully distinguished: lexical definitions (based upon current uses of a word), and stipulative or legislative definitions, which deliberately assign a meaning to a word, for the purpose of clarifying scientific or philosophical arguments. The present volume provides examples of these two kinds of definitions. §3 examines three traditional philosophical definitions of life, all of which have been elaborated prior to the emergence of biology as a specific scientific discipline: life as animation (Aristotle), life as mechanism, and life as organization (Kant). All three concepts constitute a common heritage that structures in depth a good deal of our cultural intuitions and vocabulary any time we try to think about “life”. The present volume offers examples of these three concepts in contemporary scientific discourse. The second part of the paper proposes a synthesis of the major debates developed in this volume. Three major questions have been discussed. A first issue (§4) is whether we should define life or not, and why. Most authors are skeptical about the possibility of defining life in a strong way, although all admit that criteria are useful in contexts such as exobiology, artificial life and the origins of life. §5 examines the possible kinds of definitions of life presented in the volume. Those authors who have explicitly defended that a definition of life is needed, can be classified into two categories. The first category (or standard view) refers to two conditions: individual self-maintenance and the open-ended evolution of a collection of similar entities. The other category refuse to include reproduction and evolution, and take a sort of psychic view of the living. §6 examines the relationship between the question of the definition of life and that of the origins of life. There is a close parallel between the general conceptions of the origins of life and the definitions of life.

Gayon, Jean

2010-04-01

182

Changes of Enzyme Activities and Compositions of Abnormal Fruiting Bodies Grown under Artificial Environmental Conditions in Pleurotus ostreatus.  

PubMed

This study investigated the biochemical changes of abnormal fruiting bodies grown under artificial environmental conditions in P. ostreatus. Abnormal mushroom growth during cultivation damages the production of good quality mushroom. This study showed that different environmental conditions produced morphological changes in the fruiting bodies of P. ostreatus. The fruiting bodies with morphological changes were collected and examined for differences in biochemical properties, enzyme activities, and carbohydrates composition. The enzyme activities assay showed that glucanase and chitinase activities decreased when the temperature was below or above the optimum cultivation temperature for P. ostreatus. The biochemical compositions of the abnormal mushroom were significantly different from the normal fruiting bodies. It was suggested that the changes in the biochemical composition of abnormal mushroom were caused by the unfavorable environmental conditions during mushroom cultivation. PMID:24049471

Jang, Kab Yeul; Cho, Soo Muk; June, Chang Sung; Weon, Hang Yeon; Park, Jeong Sik; Choi, Sun Gyu; Cheong, Jong Chun; Sung, Jae Mo

2005-03-01

183

Encystment of Vermamoeba (Hartmannella) vermiformis: Effects of environmental conditions and cell concentration.  

PubMed

Vermamoeba vermiformis is a free-living amoeba (FLA) which is widely distributed in the environment. It is known to colonize water systems and to be a reservoir of pathogenic bacteria, such as Legionella pneumophila. For these reasons the control of V. vermiformis represents an important health issue. However, FLA may be resistant to disinfection treatments due to the process of encystment. Thereby, it is important to better understand factors influencing this process. In this aim, we investigated the effect of temperature, pH, osmotic pressure and cell concentration on the encystment of two V. vermiformis strains. Encystment was quite fast, with a 100% encystment rate being observed after 9h of incubation. For the two strains, an optimal encystment was obtained at 25 and 37°C. Concerning pH and osmotic pressure, there were different effects on the encystment according to the tested strains. For the reference strain (ATCC 50237), the patterns of encystment were similar for pH comprised between 5 and 9 and for KCl concentrations ranging from 0.05 to 0.2molL(-1). For the environmental strain (172A) an optimal encystment was obtained for basic pH (8 and 9) and for a concentration in KCl of 0.1molL(-1). The results also clearly demonstrated that the encystment rate increased with cell concentration, suggesting that there is an inter-amoebal communication. The present study establish for the first time environmental conditions favoring encystment and would lay the foundations to better control the encystment of V. vermiformis. PMID:24721257

Fouque, Emilie; Trouilhé, Marie-Cécile; Thomas, Vincent; Humeau, Philippe; Héchard, Yann

2014-11-01

184

Reproductive performance of backcross Holstein × Brown Swiss and their Holstein contemporaries under subtropical environmental conditions.  

PubMed

The objective of this study was to evaluate the reproductive performance of the Holstein (HO) and their backcross HO × Brown Swiss (BS) under Egyptian subtropical conditions. The backcrosses were HBH (HO sires crossed with F1 BS × HO cows) and HHB (HO sires crossed with F1 HO × BS cows). Several reproductive indices and health traits for different genotypes were measured, and the effect of temperature-humidity index level (THI) on reproductive performance was investigated. Reproductive indices of the HHB backcross were better than those of the HO. The conception (30.1%) and pregnancy (28.9%) rates of the HHB backcross were significantly higher than those of the HO (28.1% and 22.6%, respectively). The calving interval and the days open of the HHB backcross were significantly shorter than those of the HO. The fertility of the HHB backcross was not affected by the level of the THI. The conception and the pregnancy rate of the HO decreased from 35.8% and 29.4%, respectively, at low THI to 16.1% and 12.1%, respectively, at high THI. The HHB backcross had the significant lowest incidence of retained placenta and metritis (9.6 and 16.9, respectively). In conclusion, despite their high milk production efficiency, pure HO had retarded reproductive performance and adaptability. On the other hand, the HHB backcross had a better adaptability and fertility under Egyptian conditions. PMID:25459027

El-Tarabany, Mahmoud S; El-Bayoumi, Khairy M

2015-02-01

185

30 CFR 585.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?  

Code of Federal Regulations, 2014 CFR

...conditions adversely affect a cable, pipeline, or facility? 585.816 Section...conditions adversely affect a cable, pipeline, or facility? If environmental or other conditions adversely affect a cable, pipeline, or facility so as to endanger the...

2014-07-01

186

Environmental conditions predict helminth prevalence in red foxes in Western Australia?  

PubMed Central

Red foxes (Vulpes vulpes) are the most common and widely distributed wild carnivore worldwide. These predators harbour a wide range of parasites, many of which may have important conservation, agricultural and zoonotic repercussions. This project investigated the occurrence of helminth parasites from the intestines of 147 red foxes across 14 sampling localities of southwest Western Australia. Helminth parasites were detected in 58% of fox intestines: Dipylidium caninum (27.7% of foxes), Uncinaria stenocephala (18.2%), Toxocara canis (14.9%), Spirometra erinaceieuropaei (5.4%), Toxascaris leonina (4.7%), Taenia serialis (1.4%), Taenia hydatigena (0.7%), unidentified Taenia spp. (4.1%), Brachylaima cribbi (0.7%), Plagiorchis maculosus (0.7%) and an Acanthocephalan; family Centrorhynchidae (2.1%). Importantly, two cestodes of agricultural significance, Echinococcus granulosus and Taenia ovis, were not detected in red foxes in this study, despite the presence of suitable intermediate hosts in the diets of these animals. Parasite richness varied from 1–3 species per host, with average parasite number varying from 1–39 worms (across all helminth species). Regression analyses indicated that the presence of four helminth parasites was related to various environmental factors. The presence of S. erinaceieuropaei (p < 0.001), T. leonina (p < 0.01) and U. stenocephala (p < 0.01) was positively associated with average relative humidity which may affect the longevity of infective stages in the environment. The presence of S. erinaceieuropaei and U. stenocephala (p < 0.001) was positively associated with 5-y-average minimum temperature which could reflect poor survival of infective stages through cold winter conditions. The presence of T. canis and U. stenocephala (p < 0.001) was positively associated with the percentage cover of native vegetation at each sampling location, which is likely to reflect transmission from native prey species acting as paratenic hosts. These data identify environmental factors affecting transmission and potential distribution of each parasite taxon, and provide important information increasing our understanding of the potential effects of environmental change on parasite ecology. PMID:24533331

Dybing, Narelle A.; Fleming, Patricia A.; Adams, Peter J.

2013-01-01

187

Effects of environmental calcium and phosphate on wear and strength of glass ionomers exposed to acidic conditions.  

PubMed

This study evaluated the effects of environmental calcium and phosphate on wear resistance, strength, and surface morphology of highly viscous glass-ionomers (HVGICs) (Fuji IX Fast [FN] and KetacMolar [KM]) when exposed to acidic conditions. Fabricated specimens were randomly divided into five groups and kept in acidic solutions (pH 3) with varied levels of calcium and phosphate ranging from 0 to 2.4 mM. After 4 weeks of conditioning, the specimens were subjected to wear testing, shear punch, and surface roughness testing as well as SEM evaluation. Multiple comparisons of wear depth (microm), shear strength (MPa), and surface roughness (Ra) between acidic conditions were performed using ANOVA/post-hoc Scheffe's test (p < 0.05). Results showed that FN and KM exposed to acidic conditions had varied wear resistance, shear strength, surface roughness, and structure depending on environmental phosphate level. Increased level of environmental phosphate led to rougher surface, greater wear resistance, and strength of FN and KM than the controls (acid of pH 3). Under SEM, the surface of both FN and KM specimens were covered by numerous small particles when environmental phosphate was high. Results suggest that environmental phosphate may improve wear resistance and shear strength of HVGICs when challenged by acids. PMID:18506830

Wang, X Y; Yap, Adrian U J

2009-02-01

188

Holocene environmental conditions in South Georgia - a multi-proxy study on a coastal marine record  

NASA Astrophysics Data System (ADS)

The Holocene environmental history of the sub-Antarctic island of South Georgia so far has been reconstructed from lake sediments, peat records and geomorphological observations. The data available indicate a postglacial ice retreat, which reached the coastal areas around the early Holocene. Climate reconstructions for the Holocene, on the other hand, provide a more complex picture, which may partly result from the influence of local effects. We present preliminary results of a multi-proxy study on a sediment core recovered in early 2013 from a coastal marine inlet (Little Jason Lagoon) in Cumberland West Bay. The results include elemental data (high resolution XRF-scans, total organic carbon (TOC), nitrogen, and sulphur, lipid biomarkers, and macrofossil data. The sediment core comprises a c. 11m long sequence, which contains a complete record of postglacial sedimentation in the inlet. Its base is formed by a diamicton, indicating a former glaciation of the site, which is overlain by well-stratified sediments passing over into more massive muds in the upper past. A radiocarbon age from the organic-rich sediments above the diamicton provides a first estimate of 9700 14C years BP for a minimum age of ice retreat. We use the elemental data to infer changes in clastic input (e.g., K/Ti ratios), productivity (TOC) and water salinity (Cl counts) in the course of the Holocene. While Little Jason Lagoon has a connection to the sea today (sill depth c. 1 m), a decrease in Cl counts downcore points to fresher conditions in the early part of the record. This could be an indicator for changing relative sea level and/or changes in the amounts of freshwater inflow from the catchment. Macroscopic plant remains and lipid biomarkers (n-alkanes, n-fatty acids and sterols) provide information on the terrestrial vegetation in the catchment and its changes through time as well as on the influence of marine conditions in the lagoon. We suggest that the record from Little Jason Lagoon provides an important link between terrestrial and marine archives of Holocene environmental change in South Georgia.

Berg, Sonja; Jivcov, Sandra; Groten, Sonja; Viehberg, Finn; Rethemeyer, Janet; Melles, Martin

2014-05-01

189

Changes in mineral soil biogeochemical cycling and environmental conditions following tree harvest in the Northeast  

NASA Astrophysics Data System (ADS)

In the northeastern United States, reductions in carbon dioxide emissions have been attempted by using local wood as a renewable alternative to oil. Although woody biomass products are readily available, recent findings suggest that forest disturbance may cause release of carbon from the deeper mineral soil. Worldwide, deep soils sequester more than half of soil carbon, making it critical in the global carbon cycle; however, most studies on the effect of harvesting have focused on the organic soil horizon. Our research aimed to uncover changes in biogeochemistry and environmental conditions in deeper, mineral soil after clear cutting forests. We quantified post-harvest mineral soil carbon pools through a regional study. We utilized stands of different ages to measure the recovery of soil carbon over time since harvest. Stands included in this study were cut approximately 5, 12, 25, 50, or 120 ybp, in order to identify changes in soil carbon over time since harvest. We sampled harvested stands in six research or protected forests across New York, New Hampshire, Massachusetts, and Vermont. Soil samples were collected to a depth of 60 cm below the surface of the mineral soil using a gas-powered augur and 9.5 cm diameter drill bit. Soil samples were analyzed at Dartmouth College. In order to understand specific changes in mineral soil carbon dynamics following harvest, measurements of carbon fluxes, such as soil respiration and DOC transport were conducted at five different-aged stands at Bartlett Experimental Forest, NH. While parameters that may influence carbon storage—such as pH, clay content, tree cover and elevation— did not vary across the different-aged stands in each forest, carbon pools did vary over time. We found changes in carbon pools in at least three experimental forests across the northeast. At Bartlett Experimental Forest, we found a gradual decline in mineral soil carbon storage from between 85-87 Mg ha-1 in 120 year old and primary forest stands to a minimum of 53 Mg ha-1 in the 75 year old stand. In our carbon flux measurements, we observed higher DOC concentrations in lysimeter samples collected at 30 cm at 12 years after harvest. We have also documented consistently higher soil temperatures across summer months at 50 cm below the mineral soil in the recently clear-cut site at Bartlett Experimental Forest. These changes in biogeochemical and environmental conditions suggest that forest clearing does affect mineral soil, and our findings may help identify a mechanism to explain the observed carbon loss from soils in clear-cut forests.

Vario, C.; Friedland, A.

2012-12-01

190

Environmental Conditioning of Skeletal Anomalies Typology and Frequency in Gilthead Seabream (Sparus aurata L., 1758) Juveniles  

PubMed Central

In this paper, 981 reared juveniles of gilthead seabream (Sparus aurata) were analysed, 721 of which were from a commercial hatchery located in Northern Italy (Venice, Italy) and 260 from the Hellenic Center for Marine Research (Crete, Greece). These individuals were from 4 different egg batches, for a total of 10 different lots. Each egg batch was split into two lots after hatching, and reared with two different methodologies: intensive and semi-intensive. All fish were subjected to processing for skeletal anomaly and meristic count analysis. The aims involved: (1) quantitatively and qualitatively analyzing whether differences in skeletal elements arise between siblings and, if so, what they are; (2) investigating if any skeletal bone tissue/ossification is specifically affected by changing environmental rearing conditions; and (3) contributing to the identification of the best practices for gilthead seabream larval rearing in order to lower the deformity rates, without selections. The results obtained in this study highlighted that: i) in all the semi-intensive lots, the bones having intramembranous ossification showed a consistently lower incidence of anomalies; ii) the same clear pattern was not observed in the skeletal elements whose ossification process requires a cartilaginous precursor. It is thus possible to ameliorate the morphological quality (by reducing the incidence of severe skeletal anomalies and the variability in meristic counts of dermal bones) of reared seabream juveniles by lowering the stocking densities (maximum 16 larvae/L) and increasing the volume of the hatchery rearing tanks (minimum 40 m3). Feeding larvae with a wide variety of live (wild) preys seems further to improve juvenile skeletal quality. Additionally, analysis of the morphological quality of juveniles reared under two different semi-intensive conditions, Mesocosm and Large Volumes, highlighted a somewhat greater capacity of Large Volumes to significantly augment the gap with siblings reared in intensive (conventional) modality. PMID:23409031

Prestinicola, Loredana; Boglione, Clara; Makridis, Pavlos; Spanò, Attilio; Rimatori, Valentina; Palamara, Elisa; Scardi, Michele; Cataudella, Stefano

2013-01-01

191

Interaction of ribonucleotides with oxide and silicate minerals under varying environmental conditions  

NASA Astrophysics Data System (ADS)

Large quantities of nucleic acids are found in natural environments, released after the death of an organism and subsequent cell lysis [1]. Nucleic acids are known to adsorb on mineral surfaces [2, 3, 4], which protect them from degradation, whether enzymatic [5, 6] or UV-mediated [7]. It may then contribute to the extracellular genetic pool available in soils to microorganisms for horizontal gene transfers [8]. In order to better understand the behaviour of extracellular nucleic acids in soils, we have investigated the interactions between nucleotides, 5'-GMP, 5'-CMP, 5'-AMP and 5'-UMP, and ?-alumina as a model compound for Al in six-fold coordination in soil minerals. We carried out batch adsorption experiments over a wide range of pH, ionic strength and surface loading. Alumina adsorbs high amounts of nucleotides > 2 ?mol/m2. In similar environmental conditions, swelling clays such as nontronite and montmorillonite adsorb less than 0.1 ?mol/m2 if the total surface area is taken under consideration. However, if only the edges of clay particles are considered, the amount of nucleotides adsorbed reaches values between 1.2 and 2 ?mol/m2 [9], similar to the alumina and consistent with ';oxide-like' surface sites on the edges of the clay particles. Surface complexation modeling enabled us to predict the speciation of the surface species on the alumina, as well as the stoichiometry and thermodynamic equilibrium constants for the adsorption of nucleotides. We used the extended triple-layer model (ETLM), that takes into account the electrical work linked to the desorption of chemisorbed water molecules during the formation of inner-sphere complexes. Two surface species are thought to form on the surface of corundum: a monodentate inner-sphere complex, dominant at pH < 7.5, and a bidentate outer-sphere complex, dominant at higher pH. Both complexes involve interactions between the negatively charged phosphate group and the positively charged surface of alumina. Our results provide a better understanding of how nucleic acids attach to mineral surfaces under varying environmental conditions in soil environments. Moreover, the predicted configuration of nucleotide surface species, bound via the phosphate group, could have implications for the abiotic formation and concentration of nucleic acids in the context of the origin of life. References : [1] Lorenz and Wackernagel (1987), Applied and environmental microbial., 2948-2952 [2] Ferris (2005), Reviews in mineralogy & geochemistry 59, 187-210 [3] Cleaves H.J. et al. (2011), Chemosphere 83, 1560-1567 [4] Arora & Kamaluddin (2009), Astrobiology 9, 165-171 [5] Cai et al. (2006), Environ. Sci. Technol. 40 (9), 2971-2976 [6] Franchi and Gallori (2005),Gene 346, 205-214 [7] Scappini et al. (2004), International Journal of Astrobiology 3(1), 17-19 [8] Levy-Booth et al. (2007), Soil Biol. Biochem. 39, 2977-2991. [9] Feuillie et al. (2013), Geochimica et Cosmochimica Acta (in press)

Feuillie, C.; Sverjensky, D. A.; Hazen, R. M.

2013-12-01

192

Biofilm formation by Streptococcus agalactiae: influence of environmental conditions and implicated virulence factors  

PubMed Central

Streptococcus agalactiae (Group B Streptococcus, GBS) is an important human pathogen that colonizes the urogenital and/or the lower gastro-intestinal tract of up to 40% of healthy women of reproductive age and is a leading cause of sepsis and meningitis in the neonates. GBS can also infect the elderly and immuno-compromised adults, and is responsible for mastitis in bovines. Like other Gram-positive bacteria, GBS can form biofilm-like three-dimensional structures that could enhance its ability to colonize and persist in the host. Biofilm formation by GBS has been investigated in vitro and appears tightly controlled by environmental conditions. Several adhesins have been shown to play a role in the formation of GBS biofilm-like structures, among which are the protein components of pili protruding outside the bacterial surface. Remarkably, antibodies directed against pilus proteins can prevent the formation of biofilms. The implications of biofilm formation in the context of GBS asymptomatic colonization and dissemination to cause invasive disease remain to be investigated in detail.

Rosini, Roberto; Margarit, Immaculada

2015-01-01

193

Overview of environmental and hydrogeologic conditions at the Merle K. "Mudhole" Smith Airport near Cordova, Alaska  

USGS Publications Warehouse

Air service to Cordova, Alaska and the surrounding region is provided by the Merle K. "Mudhole" Smith Airport, 21 kilometers east of the townsite. The Federal Aviation Administration owns or operates support facilities at the airport and wishes to consider the environmental setting and hydro- geologic conditions when evaluating options for remediation of potential contamination at these facilities. The airport is within the Copper River Delta wetlands area and the Chugach National Forest. Silts, sands, and gravels of fluvial origin underlie the airport. Potential flooding may be caused by outbursts of glacier-dammed lakes, glacier icemelt, snowmelt runoff, or precipitation. Surface spills and disposal of hazardous materials in conjunction with precipitation or flooding may adversely affect the quality of ground water. Drinking water at the airport is currently supplied by wells. Alternative drinking-water sources include local rivers and streams, transporting city water from Cordova, or undiscovered aquifers. Each alternative source, however, would likely cost significantly more to develop than using the existing shallow aquifer supply.

Dorava, J.M.; Sokup, J.M.

1994-01-01

194

Natal dispersal driven by environmental conditions interacting across the annual cycle of a migratory songbird.  

PubMed

Natal dispersal, the process through which immature individuals permanently depart their natal area in search of new sites, is integral to the ecology and evolution of animals. Insights about the underlying causes of natal dispersal arise mainly from research on species whose short dispersal distances or restricted distributions make them relatively easy to track. However, for small migratory animals, the causes of natal dispersal remain poorly understood because individuals are nearly impossible to track by using conventional mark-recapture approaches. Using stable-hydrogen isotope ratios in feathers of American redstarts (Setophaga ruticilla) captured as immature birds and again as adults, we show that habitat use during the first tropical nonbreeding season appears to interact with latitudinal gradients in spring phenology on the temperate breeding grounds to influence the distance traveled on the initial spring migration and the direction of natal dispersal. In contrast, adult redstarts showed considerable site fidelity between breeding seasons, indicating that environmental conditions did not affect dispersal patterns after the first breeding attempt. Our findings suggest that habitat occupancy during the first nonbreeding season helps determine the latitude at which this species of Neotropical-Nearctic migratory bird breeds throughout its life and emphasize the need to understand how events throughout the annual cycle interact to shape fundamental biological processes. PMID:18287030

Studds, Colin E; Kyser, T Kurt; Marra, Peter P

2008-02-26

195

Cyclic Failure Mechanisms of Thermal and Environmental Barrier Coating Systems Under Thermal Gradient Test Conditions  

NASA Technical Reports Server (NTRS)

Plasma-sprayed ZrO2-8wt%Y2O3 and mullite+BSAS/Si multilayer thermal and environmental barrier coating (TBC-EBC) systems on SiC/SiC ceramic matrix composite (CMC) substrates were thermally cyclic tested under high thermal gradients using a laser high-heat-flux rig in conjunction with furnace exposure in water-vapor environments. Coating sintering and interface damage were assessed by monitoring the real-time thermal conductivity changes during the laser heat-flux tests and by examining the microstructural changes after exposure. Sintering kinetics of the coating systems were also independently characterized using a dilatometer. It was found that the coating failure involved both the time-temperature dependent sintering and the cycle frequency dependent cyclic fatigue processes. The water vapor environments not only facilitated the initial coating conductivity increases due to enhanced sintering and interface reaction, but also promoted later conductivity reductions due to the accelerated coating cracking and delamination. The failure mechanisms of the coating systems are also discussed based on the cyclic test results and are correlated to the sintering and thermal stress behavior under the thermal gradient test conditions.

Zhu, Dongming; Lee, Kang N.; Miller, Robert A.

2002-01-01

196

Sensitivity of Latent Heating Profiles to Environmental Conditions: Implications for TRMM and Climate Research  

NASA Technical Reports Server (NTRS)

The Tropical Rainfall Measuring Mission (TRMM) as a part of NASA's Earth System Enterprise is the first mission dedicated to measuring tropical rainfall through microwave and visible sensors, and includes the first spaceborne rain radar. Tropical rainfall comprises two-thirds of global rainfall. It is also the primary distributor of heat through the atmosphere's circulation. It is this circulation that defines Earth's weather and climate. Understanding rainfall and its variability is crucial to understanding and predicting global climate change. Weather and climate models need an accurate assessment of the latent heating released as tropical rainfall occurs. Currently, cloud model-based algorithms are used to derive latent heating based on rainfall structure. Ultimately, these algorithms can be applied to actual data from TRMM. This study investigates key underlying assumptions used in developing the latent heating algorithms. For example, the standard algorithm is highly dependent on a system's rainfall amount and structure. It also depends on an a priori database of model-derived latent heating profiles based on the aforementioned rainfall characteristics. Unanswered questions remain concerning the sensitivity of latent heating profiles to environmental conditions (both thermodynamic and kinematic), regionality, and seasonality. This study investigates and quantifies such sensitivities and seeks to determine the optimal latent heating profile database based on the results. Ultimately, the study seeks to produce an optimized latent heating algorithm based not only on rainfall structure but also hydrometeor profiles.

Shepherd, J. Marshall; Einaudi, Franco (Technical Monitor)

2000-01-01

197

Ruggedizing infrared integrated Dewar-detector assemblies for harsh environmental conditions  

NASA Astrophysics Data System (ADS)

Cryogenically cooled infrared electro-optical payloads have to operate and survive frequent exposure to harsh vibrational and shock conditions typical of the modern battlefield. This necessitates the development of special approaches to ruggedizing their sensitive components. The ruggedization requirement holds true specifically for Integrated Dewar-Detector Assemblies (IDDA), where the infrared Focal Plane Array (FPA) is usually supported by a thin-walled cold finger enveloped by an evacuated tubular Dewar. Without sufficient ruggedization, harsh environmental vibration may give rise to structural resonance responses resulting in spoiled image quality and even mechanical fractures due to material fatigue. The authors present their approach for the ruggedization of the IDDA by attaching the FPA to a semi-rigid support extending from the dynamically damped Dewar envelope. A mathematical model relies on an experimentally evaluated set of frequency response functions for a reference system and a lumped model of a wideband dynamic absorber. By adding only 2% to the weight of the IDDA, the authors have managed to attenuate the relative deflection and absolute acceleration of the FPA by a factor of 3. The analytical predictions are in full agreement with experiment.

Veprik, Alexander; Ashush, Nataniel; Shlomovich, Baruch; Oppenhaim, Yaakov; Gridish, Yaakov; Kahanov, Ezra; Koifman, Alina; Tuito, Avi

2014-06-01

198

Environmental conditions at the South Col of Mount Everest and their impact on hypoxia and hypothermia experienced by mountaineers  

PubMed Central

Background Hypoxia and hypothermia are acknowledged risk factors for those who venture into high-altitude regions. There is, however, little in situ data that can be used to quantify these risks. Here, we use 7?months of continuous meteorological data collected at the South Col of Mount Everest (elevation 7,896?m above sea level) to provide the first in situ characterization of these risks near the summit of Mount Everest. Methods This is accomplished through the analysis of barometric pressure, temperature and wind speed data collected by an automatic weather station installed at the South Col. These data were also used as inputs to parameterizations of wind chill equivalent temperature (WCT) and facial frostbite time (FFT). Results The meteorological data show clear evidence of seasonality, with evidence of pre-monsoon, monsoon and post-monsoon conditions. Low pressures, cold temperatures and high wind speeds characterize the pre- and post-monsoon periods with significant variability associated with the passage of large-scale weather systems. In contrast, the monsoon period is characterized by higher pressures, warmer temperatures and lower wind speeds with a pronounced reduction in variability. These environmental conditions are reflected in WCTs as low as ?50°C and FFTs as short as 2?min during the pre- and post-monsoon periods. During the monsoon, the risk of cold injury is reduced with WCTs of order ?20°C and FFTs longer than 60?min. The daily cycle in the various parameters is also investigated in order to assess the changes in conditions that would be experienced during a typical summit day. The post-monsoon period in particular shows a muted daily cycle in most parameters that is proposed to be the result of the random timing of large-scale weather systems. Conclusions Our results provide the first in situ characterization of the risk of hypoxia and hypothermia on Mount Everest on daily, weekly and seasonal timescales, and provide additional confirmation as to the extreme environment experienced by those attempting to summit Mount Everest and other high Himalayan mountains. PMID:23849229

2012-01-01

199

Feasibility of fiber Bragg grating and long-period fiber grating sensors under different environmental conditions.  

PubMed

This paper presents the feasibility of utilizing fiber Bragg grating (FBG) and long-period fiber grating (LPFG) sensors for nondestructive evaluation (NDE) of infrastructures using Portland cement concretes and asphalt mixtures for temperature, strain, and liquid-level monitoring. The use of hybrid FBG and LPFG sensors is aimed at utilizing the advantages of two kinds of fiber grating to implement NDE for monitoring strains or displacements, temperatures, and water-levels of infrastructures such as bridges, pavements, or reservoirs for under different environmental conditions. Temperature fluctuation and stability tests were examined using FBG and LPFG sensors bonded on the surface of asphalt and concrete specimens. Random walk coefficient (RWC) and bias stability (BS) were used for the first time to indicate the stability performance of fiber grating sensors. The random walk coefficients of temperature variations between FBG (or LPFG) sensor and a thermocouple were found in the range of -0.7499 °C/ [square root]h to -1.3548 °C/ [square root]h. In addition, the bias stability for temperature variations, during the fluctuation and stability tests with FBG (or LPFG) sensors were within the range of 0.01 °C/h with a 15-18 h time cluster to 0.09 °C/h with a 3-4 h time cluster. This shows that the performance of FBG or LPFG sensors is comparable with that of conventional high-resolution thermocouple sensors under rugged conditions. The strain measurement for infrastructure materials was conducted using a packaged FBG sensor bonded on the surface of an asphalt specimen under indirect tensile loading conditions. A finite element modeling (FEM) was applied to compare experimental results of indirect tensile FBG strain measurements. For a comparative analysis between experiment and simulation, the FEM numerical results agreed with those from FBG strain measurements. The results of the liquid-level sensing tests show the LPFG-based sensor could discriminate five stationary liquid-levels and exhibits at least 1,050-mm liquid-level measurement capacity. Thus, the hybrid FBG and LPFG sensors reported here could benefit the NDE development and applications for infrastructure health monitoring such as strain, temperature and liquid-level measurements. PMID:22163460

Wang, Jian-Neng; Tang, Jaw-Luen

2010-01-01

200

Morphology of biogenic iron oxides records microbial physiology and environmental conditions: toward interpreting iron microfossils.  

PubMed

Despite the abundance of Fe and its significance in Earth history, there are no established robust biosignatures for Fe(II)-oxidizing micro-organisms. This limits our ability to piece together the history of Fe biogeochemical cycling and, in particular, to determine whether Fe(II)-oxidizers played a role in depositing ancient iron formations. A promising candidate for Fe(II)-oxidizer biosignatures is the distinctive morphology and texture of extracellular Fe(III)-oxyhydroxide stalks produced by mat-forming microaerophilic Fe(II)-oxidizing micro-organisms. To establish the stalk morphology as a biosignature, morphologic parameters must be quantified and linked to the microaerophilic Fe(II)-oxidizing metabolism and environmental conditions. Toward this end, we studied an extant model organism, the marine stalk-forming Fe(II)-oxidizing bacterium, Mariprofundus ferrooxydans PV-1. We grew cultures in flat glass microslide chambers, with FeS substrate, creating opposing oxygen/Fe(II) concentration gradients. We used solid-state voltammetric microelectrodes to measure chemical gradients in situ while using light microscopy to image microbial growth, motility, and mineral formation. In low-oxygen (2.7-28 ?m) zones of redox gradients, the bacteria converge into a narrow (100 ?m-1 mm) growth band. As cells oxidize Fe(II), they deposit Fe(III)-oxyhydroxide stalks in this band; the stalks orient directionally, elongating toward higher oxygen concentrations. M. ferrooxydans stalks display a narrow range of widths and uniquely biogenic branching patterns, which result from cell division. Together with filament composition, these features (width, branching, and directional orientation) form a physical record unique to microaerophilic Fe(II)-oxidizer physiology; therefore, stalk morphology is a biosignature, as well as an indicator of local oxygen concentration at the time of formation. Observations of filamentous Fe(III)-oxyhydroxide microfossils from a ~170 Ma marine Fe-Si hydrothermal deposit show that these morphological characteristics can be preserved in the microfossil record. This study demonstrates the potential of morphological biosignatures to reveal microbiology and environmental chemistry associated with geologic iron formation depositional processes. PMID:23790206

Krepski, S T; Emerson, D; Hredzak-Showalter, P L; Luther, G W; Chan, C S

2013-09-01

201

Characteristics of lead(II) adsorption onto "Natural Red Earth" in simulated environmental conditions  

NASA Astrophysics Data System (ADS)

Lead is considered as a non-biodegradable and potentially toxic heavy metal and it is found as a common environmental pollutant. Adsorption characteristics of Pb(II) onto natural iron and aluminum coated sand, which is called Natural Red Earth (NRE), have been studied to ascertain the effect of pH, ionic strength, initial sorbate concentrations, temperature and time. Lead(II) adsorption achieved its maximum adsorption of nearly 100% at neutral to slightly acidic conditions. The optimum pH was nearly 5.5 and 6.5 for 2.41 and 24.1 ?mol/L initial Pb(II) concentrations, respectively. Lead(II) adsorption was independent of 100 fold variation of ionic strength (0.001 - 0.1), indirectly evidencing dominance of an inner-sphere surface complexation mechanism for 10 fold variation of initial Pb(II) concentrations (2.41 and 24.1 ?mol/L). Adsorption edges were quantified with a 2pK generalized diffuse double layer model considering two site types, >FeOH and >AlOH, for Pb(II) binding. The modeling results better fit with the mixture of monodentate and bidentated binding of Pb(II) onto >FeOH site and bidentate binding of Pb(II) onto >AlOH site. The intrinsic constants obtained were log KFeOPb=13.93, log K(FeO)2Pb=11.88 and log K(AlO)2Pb=13.21. Time required to reach the equilibrium was also increase from 15 min to 1hr with increasing Pb(II) concentrations from 2.41 to 24.1 ?mol/L. Kinetic data fitted better to pseudo second order kinetic model. Lead(II) adsorption onto NRE was better explained by Two-site Langmuir isotherm with sorption maximum of 1.39x10-2 and 2.30x10-3 mol/kg for two sites with different affinities. Negative Gibbs free energy values indicated spontaneity of Pb(II) adsorption onto NRE, and entropy and enthalpy of adsorption were 124.04 J/K mol and 17.71 KJ/mol, respectively. These results suggested that the NRE could be effectively used as a low cost candidate for removal of Pb(II) from environmental water, since use of low cost materials to treat contaminated water is of importance for the developing world.

Mahatantila, K.; Vithanage, M. S.; Seike, Y.; Okumura, M.

2011-12-01

202

Environmental Exposure Conditions for Teflon FEP on the Hubble Space Telescope Investigated  

NASA Technical Reports Server (NTRS)

The Hubble Space Telescope (HST) was launched into low Earth orbit on April 24,1990. During the first servicing mission in December 1993 (3.6 years after launch), multilayer insulation (MLI) blankets were retrieved from the two magnetic sensing systems located on the light shield. Retrieval of one of the solar arrays during this mission also provided MLI blanket material from the solar array drive arm. These MLI materials were analyzed in ground-based facilities, and results indicate that the space-facing outer layer of the MLI, aluminized Teflon FEP (DuPont; fluorinated ethylene propylene), was beginning to degrade. Close inspection of the FEP revealed through-the-thickness cracks in areas with the highest solar exposure and stress concentration. During the second servicing mission in February 1997 (6.8 years after launch), astronauts observed and documented severe cracking in the outer layer of the MLI blankets on both the solar-facing and anti-solar-facing surfaces. During this second mission, some material from the outer layer of the light shield MLI was retrieved and subsequently analyzed in ground-based facilities. After the second servicing mission, a Failure Review Board was convened by NASA Goddard Space Flight Center to address the MLI degradation problem on HST. Members of the Electro-Physics Branch of the NASA Glenn Research Center at Lewis Field participated on this board. To determine possible degradation mechanisms, board researchers needed to consider all environmental constituents to which the FEP MLI surfaces were exposed. On the basis of measurements, models, and predictions, environmental exposure conditions for FEP surfaces on HST were estimated for various time periods from launch in 1990 through 2010, the planned end-of-life for HST. The table summarizes these data including the number and temperature ranges of thermal cycles; equivalent Sun hours; fluence and absorbed radiation dose from solar event x rays; fluence and absorbed dose from solar wind protons and electrons trapped in Earth s magnetic field; fluence of plasma electrons and protons; and atomic oxygen fluence.

Dever, Joyce A.; deGroh, Kim K.; Banks, Bruce A.; Townsend, Jacqueline a.; Barth, Janet L.; Thomson, Shaun; Gregory, Teri; Savage, William J.

2000-01-01

203

Effects of Environmental Conditions during Stream, Estuary, and Ocean Residency on Chinook Salmon Return Rates in the Skagit River, Washington  

Microsoft Academic Search

We predicted 22 years of return rates for wild Chinook salmon Oncorhynchus tshawytscha as a function of environmental conditions experienced during residency in freshwater, tidal delta, bay, and ocean habitats as well as as an indicator of density dependence (based on egg production) across life stages. The best predictors of return rate included the magnitude of floods experienced during incubation,

Correigh M. Greene; David W. Jensen; George R. Pess; E. Ashley Steel; Eric Beamer

2005-01-01

204

Chemical and Physical Environmental Conditions Underneath Mat and Canopy-Forming Macroalgae, and Their Effects on Understorey Corals  

Microsoft Academic Search

Disturbed coral reefs are often dominated by dense mat- or canopy-forming assemblages of macroalgae. This study investigated how such dense macroalgal assemblages change the chemical and physical microenvironment for understorey corals, and how the altered environmental conditions affect the physiological performance of corals. Field measurements were conducted on macroalgal-dominated inshore reefs in the Great Barrier Reef in quadrats with macroalgal

Claudine Hauri; Katharina E. Fabricius; Britta Schaffelke; Craig Humphrey; Stuart Humphries

2010-01-01

205

Casein films: effects of formulation, environmental conditions, and addition of citric pectin on the structure and mechanical properties  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thin casein films for food packaging applications reportedly possess good strength and low oxygen permeability, but low water-resistance and elasticity. Modifying and customizing the mechanical properties of the films to target specific behaviors depending on environmental conditions would enable a...

206

GCM Simulations of Neoproterozoic "Snowball Earth" Conditions: Implications for the Environmental Limits on Terrestrial Metazoans and Their Extraterrestrial Analogues  

NASA Technical Reports Server (NTRS)

The Neoproterozoic Snowball Earth intervals provide excellent opportunities to examine the environmental limits on terrestrial metazoans. A series of GCM simulations was run in order to quantify climatic conditions during these intervals. Additional information is contained in the original extended abstract.

Sohl, L. E.; Chandler, M. A.

2001-01-01

207

Environmental Conditions that Favor Life in a Fresh Water Ecosystem:A Case-Based Biology Lesson Plan  

NSDL National Science Digital Library

In this unit students will examine a case study of fish kill in Nancy Creek and identify the environmental conditions that favor life in a fresh water ecosystem. Students will also: analyze and interpret data; design and construct a scientific experiment; produce written reports of laboratory activities in accepted formats; and investigate the components of a fresh water ecosystem.

Bland, J.; Carter, S.; Mattox, S.; Mccrary, T.

2007-08-17

208

Variation in gene expression of Andropogon gerardii in response to altered environmental conditions associated with climate change  

Technology Transfer Automated Retrieval System (TEKTRAN)

The ecological consequences of changes in environmental conditions associated with global climate change will depend in part on how organisms respond to those shifts at the individual level. Currently our understanding of genetic responses of plants to alterations in precipitation and temperature as...

209

Organic composition and environmental conditions in mangrove sediments : a key for reconstructing the evolution of theFrench Guiana coast.  

E-print Network

Organic composition and environmental conditions in mangrove sediments : a key for reconstructing remarquable résultant du système dispersif amazonien. Une mangrove, essentiellement composée d vie de la mangrove. Les lambeaux de forêt résiduels ont pu être datés par analyse d'images Spot

Paris-Sud XI, Université de

210

Seeking Balance: The Importance of Environmental Conditions in Men and Women Faculty's Well-Being  

ERIC Educational Resources Information Center

Faculty retention is of increasing importance in the current economic climate. We examined the role of an institution's environmental conditions (e.g., climate, collegiality, and administration) in faculty well-being (i.e., job satisfaction, intent to leave, emotional and physical health). Women reported significantly lower well-being and a…

McCoy, Shannon K.; Newell, Ellen E.; Gardner, Susan K.

2013-01-01

211

Socio-environmental conditions, intestinal parasitic infections and nutritional status in children from a suburban neighborhood of La Plata, Argentina  

Microsoft Academic Search

We analyzed intestinal parasitic infections in children aged 1–12 years from a poor neighborhood in La Plata, Argentina, and determined the correlations with their nutritional status and socio-environmental conditions. We performed parasitological analyses with anal brushed technique (for Enterobius vermicularis eggs) and fecal samples, employing the techniques of Ritchie, Carles Barthelemy and Willis. The worm burdens of nematodes were estimated

María I. Gamboa; Graciela T. Navone; Alicia B. Orden; María F. Torres; Luis E. Castro; Evelia E. Oyhenart

2011-01-01

212

Natural selection on a measure of parasite resistance varies across ages and environmental conditions in a wild mammal  

E-print Network

Natural selection on a measure of parasite resistance varies across ages and environmental Individuals in natural populations are under constant threat of infection from parasitic organisms that have detrimental effects on host condition and fitness (Poulin, 2007). Infection and damage by parasites may

Lummaa, Virpi

213

Surface studies of dry and solid lubricants under different environmental conditions  

NASA Astrophysics Data System (ADS)

Advanced lubrication schemes depend on the presence of specific solids at or the continuous delivery of a gas to the sliding interface to manage friction and wear, and are known to have a strong environmental dependence. An in-vacuo pin-on-disc tribometer was designed to allow controlled environmental testing of the solid lubricants in order to determine the role of atmospheric components on their frictional behavior. Solid lubrication testing of highly oriented pyrolytic graphite, MoS2-Sb2O 3-Au, and MoS2-Sb2O3-C films was carried out under environments of 760 Torr air (50% relative humidity), 150 Torr oxygen, 8 Torr water, 610 Torr nitrogen, and 10-7 Torr vacuum. Dry lubrication testing of the native oxide of silicon (100) surfaces was carried out under environments of 760 Torr air (50% relative humidity), 1 Torr pentanol, and 10-7 Torr vacuum. Pin-on-disc tribometry revealed a strong dependence of friction and wear as a function of sliding environment. MoS2-Sb2O3-Au and MoS2-Sb 2O3-C films were strongly affected by the presence of water molecules. Friction and wear were observed to increase in the presence of partial pressures of water when compared to vacuum, oxygen, and nitrogen environmental testing. Spectroscopic analysis of the MoS2-Sb2O 3-Au and MoS2-Sb2O3-C films showed a general trend of MoS2 expression at the surface of low friction wear tracks. However, high friction could not be directly linked to the expression of a specific species within the wear track. X-ray photoelectron spectroscopy of the tracks created under ambient and water environments yielding high friction showed no clear relationship between the two conditions, even though their frictional behavior was similar. As revealed by atomic force microscopy measurements, the microstructure of the wear tracks of MoS2-Sb2O3-Au films produced under vacuum were predominantly low friction MoS2. The vacuum wear tracks of MoS2-Sb2O3-C films showed a mixed microstructure with both low friction MoS2, and moderate friction C. Ambient wear tracks for MoS2-Sb2O 3-Au films contained a minor, higher friction constituent, identified as Au, in the presence of the major constituent, MoS2. Ambient wear tracks for MoS2-Sb2O3-C films were more complex, expressing a majority of higher friction Sb2O3 and graphite constituents, with a reduced fraction of MoS2. These micro-tribometry measurements correlated well with those made by the pin-on-disc tribometer and X-ray photoelectron spectroscopy characterization. Dry or vapor-phase lubrication methods employing 1-pentanol were effective in reducing the friction of silicon (100) compared to sliding under ambient or vacuum environments. A continuous supply of 1-pentanol served to lubricate silicon surfaces through the formation of a tribochemical film which was composed primarily of (CH2)x species. However, the presence of a tribofilm was not responsible for the lowered friction coefficient, but it did enable the extreme wear protection previously reported for this lubrication technique.

Dudder, Gregory James

214

Sensitive and selective culture medium for detection of environmental Clostridium difficile isolates without requirement for anaerobic culture conditions.  

PubMed

Effective and easy-to-use methods for detecting Clostridium difficile spore contamination would be useful for identifying environmental reservoirs and monitoring the effectiveness of room disinfection. Culture-based detection methods are sensitive for detecting C. difficile, but their utility is limited due to the requirement of anaerobic culture conditions and microbiological expertise. We developed a low-cost selective broth medium containing thioglycolic acid and l-cystine, termed C. difficile brucella broth with thioglycolic acid and l-cystine (CDBB-TC), for the detection of C. difficile from environmental specimens under aerobic culture conditions. The sensitivity and specificity of CDBB-TC (under aerobic culture conditions) were compared to those of CDBB (under anaerobic culture conditions) for the recovery of C. difficile from swabs collected from hospital room surfaces. CDBB-TC was significantly more sensitive than CDBB for recovering environmental C. difficile (36/41 [88%] versus 21/41 [51%], respectively; P = 0.006). C. difficile latex agglutination, an enzyme immunoassay for toxins A and B or glutamate dehydrogenase, and a PCR for toxin B genes were all effective as confirmatory tests. For 477 total environmental cultures, the specificity of CDBB-TC versus that of CDBB based upon false-positive yellow-color development of the medium without recovery of C. difficile was 100% (0 false-positive results) versus 96% (18 false-positive results), respectively. False-positive cultures for CDBB were attributable to the growth of anaerobic non-C. difficile organisms that did not grow in CDBB-TC. Our results suggest that CDBB-TC provides a sensitive and selective medium for the recovery of C. difficile organisms from environmental samples, without the need for anaerobic culture conditions. PMID:24958803

Cadnum, Jennifer L; Hurless, Kelly N; Deshpande, Abhishek; Nerandzic, Michelle M; Kundrapu, Sirisha; Donskey, Curtis J

2014-09-01

215

Spatial structuring of an evolving life-history strategy under altered environmental conditions.  

PubMed

Human disturbances to ecosystems have created challenges to populations worldwide, forcing them to respond phenotypically in ways that increase their fitness under current conditions. One approach to examining population responses to disturbance in species with complex life histories is to study species that exhibit spatial patterns in their phenotypic response across populations or demes. In this study, we investigate a threatened population of fall chinook salmon (Oncorhynchus tshawytscha) in the Snake River of Idaho, in which a significant fraction of the juvenile population have been shown to exhibit a yearling out-migration strategy which had not previously been thought to exist. It has been suggested that dam-related environmental changes may have altered the selective pressures experienced by out-migrating fall chinook, driving evolution of a later and more selectively advantageous migration strategy. Using isotopic analysis of otoliths from returning adult spawners, we reconstructed the locations of individual fish at three major juvenile life stages to determine if the representation of the yearling life history was geographically structured within the population. We reconstructed juvenile locations for natal, rearing and overwintering life stages in each of the major spawning areas in the basin. Our results indicate that the yearling life-history strategy is predominantly represented within one of the main spawning regions, the Clearwater River, rather than being distributed throughout the basin. Previous studies have shown the Clearwater River to have cooler temperatures, later hatch dates, and later outmigration of juveniles, indicating a link between environment and expression of the yearling life history. Our data suggest that this new yearling life history may be disproportionally represented in returning adult spawners, indicating selection for this life history within the population. PMID:23423520

Hegg, Jens C; Kennedy, Brian P; Chittaro, Paul M; Zabel, Richard W

2013-08-01

216

Concrete Durability in Harsh Environmental Conditions Exposed to Freeze Thaw Cycles  

NASA Astrophysics Data System (ADS)

Under line Pathology of Materials; one of the environmental causes of damage effects on concrete is freeze thaw cycles, which deteriorate the concrete exposed to water in cold weather. An example of old concrete is a dam project that was built in Canada, in the early 1909-1913. This project was reconstructed in 1932, 1934 and 1972, and required renovation due to the ice abrasion with the freeze/thaw cycles. Before completing any renovation, it is required to analyze the structural stability and the concrete failures of this dam. An investigation was conducted to determine the quality of the concrete in the Piers and in the Bridge Deck Slab. It was also required to determine the basic materials’ properties that constitute this project. This will improve the analysis of its stability [10]. Core samples were examined and used as test samples, for the Alkali-Silica reactivity test samples, as well as the compressive strength test, the Chloride Ion test, and the freeze thaw testing which was performed on two sets of 12 concrete core samples that were taken from different locations in the project. These locations are the representations of the age of the concrete. Thus, the age difference between the samples’ two sets is four decades. Testing was performed on prisms cut from cores. ASTM C-666 procedure (A) was applied using an automatic test system [6]. It was suggested that a plan for renovation of this project should be performed after the analysis is undertaken to assess the conditions estimating the remaining life of the concrete in this project [15].

Hamze, Youssef

217

Quantification of vapor intrusion pathways into a slab-on-ground building under varying environmental conditions.  

PubMed

Potential hydrocarbon-vapor intrusion pathways into a building through a concrete slab-on-ground were investigated and quantified under a variety of environmental conditions to elucidate the potential mechanisms for indoor air contamination. Vapor discharge from the uncovered open ground soil adjacent to the building and subsequent advection into the building was unlikely due to the low soil-gas concentrations at the edge of the building as a result of aerobic biodegradation of hydrocarbon vapors. When the building's interior was under ambient pressure, a flux of vapors into the building due to molecular diffusion of vapors through the building's concrete slab (cyclohexane 11 and methylcyclohexane 31 mg m(-2) concrete slab day(-1)) and short-term (up to 8 h) cyclical pressure-driven advection of vapors through an artificial crack (cyclohexane 4.2 x 10(3) and methylcyclohexane 1.2 x 10(4) mg m(-2) cracks day(-1)) was observed. The average subslab vapor concentration under the center of the building was 25,000 microg L(-1). Based on the measured building's interiorvapor concentrations and the building's air exchange rate of 0.66 h(-1), diffusion of vapors through the concrete slab was the dominantvapor intrusion pathway and cyclical pressure exchanges resulted in a near zero advective flux. When the building's interior was under a reduced pressure (-12 Pa), advective transport through cracks or gaps in the concrete slab (cyclohexane 340 and methylcyclohexane 1100 mg m(-2) cracks day(-1)) was the dominant vapor intrusion pathway. PMID:19244997

Patterson, Bradley M; Davis, Greg B

2009-02-01

218

Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions  

NASA Technical Reports Server (NTRS)

Previous spaceflight reports attribute changes in plant ultrastructure to microgravity, but it was thought that the changes might result from growth in uncontrolled environments during spaceflight. To test this possibility, potato explants were examined (a leaf, axillary bud, and small stem segment) grown in the ASTROCULTURETM plant growth unit, which provided a controlled environment. During the 16 d flight of space shuttle Columbia (STS-73), the axillary bud of each explant developed into a mature tuber. Upon return to Earth, tuber slices were examined by transmission electron microscopy. Results showed that the cell ultrastructure of flight-grown tubers could not be distinguished from that of tuber cells grown in the same growth unit on the ground. No differences were observed in cellular features such as protein crystals, plastids with starch grains, mitochondria, rough ER, or plasmodesmata. Cell wall structure, including underlying microtubules, was typical of ground-grown plants. Because cell walls of tubers formed in space were not required to provide support against the force due to gravity, it was hypothesized that these walls might exhibit differences in wall components as compared with walls formed in Earth-grown tubers. Wall components were immunolocalized at the TEM level using monoclonal antibodies JIM 5 and JIM 7, which recognize epitopes of pectins, molecules thought to contribute to wall rigidity and cell adhesion. No difference in presence, abundance or distribution of these pectin epitopes was seen between space- and Earth-grown tubers. This evidence indicates that for the parameters studied, microgravity does not affect the cellular structure of plants grown under controlled environmental conditions.

Cook, Martha E.; Croxdale, Judith G.; Tibbitts, T. W. (Principal Investigator)

2003-01-01

219

Weeks Island brine diffuser site study: baseline conditions and environmental assessment technical report  

SciTech Connect

This technical report presents the results of a study conducted at two alternative brine diffuser sites (A and B) proposed for the Weeks Island salt dome, together with an analysis of the potential physical, chemical, and biological effects of brine disposal for this area of the Gulf of Mexico. Brine would result from either the leaching of salt domes to form or enlarge oil storage caverns, or the subsequent use of these caverns for crude oil storage in the Strategic Petroleum Reserve (SPR) program. Brine leached from the Weeks Island salt dome would be transported through a pipeline which would extend from the salt dome either 27 nautical miles (32 statute miles) for Site A, or 41 nautical miles (47 statute miles) for Site B, into Gulf waters. The brine would be discharged at these sites through an offshore diffuser at a sustained peak rate of 39 ft/sup 3//sec. The disposal of large quantities of brine in the Gulf could have a significant impact on the biology and water quality of the area. Physical and chemical measurements of the marine environment at Sites A and B were taken between September 1977 and July 1978 to correlate the existing environmental conditions with the estimated physical extent of tthe brine discharge as predicted by the MIT model (US Dept. of Commerce, 1977a). Measurements of wind, tide, waves, currents, and stratification (water column structure) were also obtained since the diffusion and dispersion of the brine plume are a function of the local circulation regime. These data were used to calculate both near- and far-field concentrations of brine, and may also be used in the design criteria for diffuser port configuration and verification of the plume model. Biological samples were taken to characterize the sites and to predict potential areas of impact with regard to the discharge. This sampling focused on benthic organisms and demersal fish. (DMC)

None

1980-12-12

220

Growth conditions and environmental factors impact aerosolization but not virulence of Francisella tularensis infection in mice  

PubMed Central

In refining methodology to develop a mouse model for inhalation of Francisella tularensis, it was noted that both relative humidity and growth media impacted the aerosol concentration of the live vaccine strain (LVS) of F. tularensis. A relative humidity of less than 55% had a negative impact on the spray factor, the ratio between the concentration of LVS in the aerosol and the nebulizer. The spray factor was significantly higher for LVS grown in brain heart infusion (BHI) broth than LVS grown in Mueller–Hinton broth (MHb) or Chamberlain's chemically defined medium (CCDM). The variability between aerosol exposures was also considerably less with BHI. LVS grown in BHI survived desiccation far longer than MHb-grown or CCDM-grown LVS (~70% at 20 min for BHI compared to <50% for MHb and CCDM). Removal of the capsule by hypertonic treatment impacted the spray factor for CCDM-grown LVS or MHb-grown LVS but not BHI-grown LVS, suggesting the choice of culture media altered the adherence of the capsule to the cell membrane. The choice of growth media did not impact the LD50 of LVS but the LD99 of BHI-grown LVS was 1 log lower than that for MHb-grown LVS or CCDM-grown LVS. Splenomegaly was prominent in mice that succumbed to MHb- and BHI-grown LVS but not CCDM-grown LVS. Environmental factors and growth conditions should be evaluated when developing new animal models for aerosol infection, particularly for vegetative bacterial pathogens. PMID:23087911

Faith, Seth A.; Smith, Le'Kneitah P.; Swatland, Angela S.; Reed, Douglas S.

2012-01-01

221

Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic  

NASA Astrophysics Data System (ADS)

The Cape Lookout cold-water coral area off the coast of North Carolina forms the shallowest and northernmost cold-water coral mound area on the Blake Plateau in the NW Atlantic. Cold-water coral habitats near Cape Lookout are occasionally bathed in the Gulf Stream, which is characterised by oligotrophic warm water and strong surface currents. Here, we present the first insights into the mound distribution and morphology, sedimentary environment and coral cover and near-bed environmental conditions as recorded by bottom landers from this coral area. The mounds occur between 320-550 m water depth and are characterised by high acoustic backscatter indicating the presence of hard structure. Three distinct mound morphologies were observed, (1) a mound with a flattened top at 320 m, (2) multi-summited mounds with a tear drop shape in the middle part of the area and (3) a single mound at 540 m water depth. Echosounder profiles show the presence of a strong reflector underneath all mound structures that forms the base of the mounds. This reflector cropped out at the downstream side of the single mound and consists of carbonate slabs. Video analysis revealed that all mounds are covered by Lophelia pertusa and that living colonies only occur close to the summits of the SSW side of the mounds, which is the side that faces the strongest currents. Off mound areas were characterised by low backscatter and sediment ripples, indicating the presence of relatively strong bottom currents. Two bottom landers were deployed amidst the coral mounds between December 2009 and May 2010. Both landers recorded prominent features near the seabed as well as in the overlying water column. The period between December and April was characterised by several events of increasing temperature and salinity, coinciding with increased flow and near-bed acoustic backscatter. During these events temperature fluctuated by up to 9 °C within a day, which is the largest temperature variability as measured so far in a cold-water coral habitat. Warm events, related to Gulf Stream meanders, had the duration of roughly one week and the current during these events was directed to the NNE. The consequences of such events must be significant given the strong effects of temperature on the metabolism of cold-water corals. Furthermore, elevated acoustic backscatter values and high mass fluxes were also recorded during these events, indicating a second stressor that may affect the corals. The abrasive nature of sand in combination with strong currents might sand blast the corals. We conclude that cold-water corals near Cape Lookout live under extreme conditions that limit mound growth at present.

Mienis, F.; Duineveld, G.; Davies, A. J.; Lavaleye, M. J. N.; Ross, S. W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M.; de Haas, H.; Brooke, S.; van Weering, T.

2013-12-01

222

Safety conditioning technology for mining region's environmental system based on Catastrophe Theory  

Microsoft Academic Search

The safety of mining region's environmental system is a basic prerequisite of the sustainable development of mining region's economy and society. The maintenance of mining region's environmental system safety by taking effective measures has great significance for mining regions in China function as residential community. One of the major problems facing mining region's sustainable development is how to keep the

Dachao Zhang

2011-01-01

223

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

PubMed Central

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

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

2012-01-01

224

Variety in cereal production in the Late Bronze and Early Iron Ages in relation to environmental conditions  

NASA Astrophysics Data System (ADS)

The objective of this paper is to assess the relationship between the cereals cultivated in the Late Bronze and Early Iron Ages (ca. 1250 - 400 cal BC) on the territory of present day Czech Republic and their environmental settings. The representation of various charred cereal caryopses in the archaeobotanical assemblages from 35 archaeological sites differ, especially in the proportion of wheats and barley. The cereal assemblages were compared with a site altitude, weather conditions,soils and soil productivity. The most important environmental variable influencing the choice of a particular crop seem to be altitude associated with the length of growing season (afterwards the soil conditions). Although the ecological requirements of cereals cultivated in the Late Bronze and Early Iron Ages are not known, they presumably thrived under similar conditions to present day species/varieties and that the strategy of past crop husbandry was based on similar principles as today, e.g. the flexible adaptations to local environmental conditions in an effort to achieve optimal yields and to reduce the danger of crop failure.

Poništiak, Štefan; Dreslerová, Dagmar; Šefrna, Lud?k; Ko?ár, Petr; Chuman, Tomáš

2013-04-01

225

THE ROLE OF INDIVIDUAL VARIABILITY IN POPULATION DYNAMICS UNDER CHANGING ENVIRONMENTAL CONDITIONS  

EPA Science Inventory

Environmental variability can influence species distributions through changes in survival, fecundity, behavior, and metabolic activities. As worldwide coastal populations rise, the associated deforestation and development can increase both quantities and variability in runoff...

226

Household Environmental Conditions Are Associated with Enteropathy and Impaired Growth in Rural Bangladesh  

PubMed Central

We assessed the relationship of fecal environmental contamination and environmental enteropathy. We compared markers of environmental enteropathy, parasite burden, and growth in 119 Bangladeshi children (? 48 months of age) across rural Bangladesh living in different levels of household environmental cleanliness defined by objective indicators of water quality and sanitary and hand-washing infrastructure. Adjusted for potential confounding characteristics, children from clean households had 0.54 SDs (95% confidence interval [CI] = 0.06, 1.01) higher height-for-age z scores (HAZs), 0.32 SDs (95% CI = ?0.72, 0.08) lower lactulose:mannitol (L:M) ratios in urine, and 0.24 SDs (95% CI = ?0.63, 0.16) lower immunoglobulin G endotoxin core antibody (IgG EndoCAb) titers than children from contaminated households. After adjusting for age and sex, a 1-unit increase in the ln L:M was associated with a 0.33 SDs decrease in HAZ (95% CI = ?0.62, ?0.05). These results are consistent with the hypothesis that environmental contamination causes growth faltering mediated through environmental enteropathy. PMID:23629931

Lin, Audrie; Arnold, Benjamin F.; Afreen, Sadia; Goto, Rie; Huda, Tarique Mohammad Nurul; Haque, Rashidul; Raqib, Rubhana; Unicomb, Leanne; Ahmed, Tahmeed; Colford, John M.; Luby, Stephen P.

2013-01-01

227

Tracking the autumn migration of the bar-headed goose (Anser indicus) with satellite telemetry and relationship to environmental conditions  

USGS Publications Warehouse

The autumn migration routes of bar-headed geese captured before the 2008 breeding season at Qinghai Lake, China, were documented using satellite tracking data. To assess how the migration strategies of bar-headed geese are influenced by environmental conditions, the relationship between migratory routes, temperatures, and vegetation coverage at stopovers sites estimated with the Normalized Difference Vegetation Index (NDVI) were analyzed. Our results showed that there were four typical migration routes in autumn with variation in timing among individuals in start and end times and in total migration and stopover duration. The observed variation may be related to habitat type and other environmental conditions along the routes. On average, these birds traveled about 1300 to 1500?km, refueled at three to six stopover sites and migrated for 73 to 83 days. The majority of the habitat types at stopover sites were lake, marsh, and shoal wetlands, with use of some mountainous regions, and farmland areas.

Zhang, Yaonan; Hao, Meiyu; Takekawa, John Y.; Lei, Fumin; Yan, Baoping; Prosser, Diann J.; Douglas, David C.; Xing, Zhi; Newman, Scott H.

2011-01-01

228

Stability of Essential Oil Yield and Quality Characters in Japanese Mint (Mentha arvensis L.) Under Varied Environmental Conditions  

Microsoft Academic Search

Phenotypic stability for herb yield, leaf-stem ratio, essential oil yield, oil content and menthol and menthone contents were estimated for seven genotypes of Mentha arvensis over eight widely differing environmental conditions. Wide range of variability was observed in each character over environment but none of the environments was found to be the best for all the characters. Hybrid CIMAP\\/MAS-77 yielded

Srikant Sharma; Bali R. Tyagi; Ali A. Naqvi; Raghunath S. Thakur

1992-01-01

229

Long-term human response to uncertain environmental conditions in the Andes  

PubMed Central

Human interaction with the physical environment has increasingly transformed Earth-system processes. Reciprocally, climate anomalies and other processes of environmental change of natural and anthropogenic origin have been affecting, and often disrupting, societies throughout history. Transient impact events, despite their brevity, can have significant long-term impact on society, particularly if they occur in the context of ongoing, protracted environmental change. Major climate events can affect human activities in critical conjunctures that shape particular trajectories of social development. Here we report variable human responses to major environmental events in the Andes with a particular emphasis on the period from anno Domini 500–1500 on the desert north coast of Perú. We show that preindustrial agrarian societies implemented distinct forms of anticipatory response to environmental change and uncertainty. We conclude that innovations in production strategies and agricultural infrastructures in these indigenous societies reflect differential social response to both transient (El Niño–Southern Oscillation events) and protracted (desertification) environmental change. PMID:15024122

Dillehay, Tom D.; Kolata, Alan L.

2004-01-01

230

Hypoxia tolerance of common sole juveniles depends on dietary regime and temperature at the larval stage: evidence for environmental conditioning  

PubMed Central

An individual's environmental history may have delayed effects on its physiology and life history at later stages in life because of irreversible plastic responses of early ontogenesis to environmental conditions. We chose a marine fish, the common sole, as a model species to study these effects, because it inhabits shallow marine areas highly exposed to environmental changes. We tested whether temperature and trophic conditions experienced during the larval stage had delayed effects on life-history traits and resistance to hypoxia at the juvenile stage. We thus examined the combined effect of global warming and hypoxia in coastal waters, which are potential stressors to many estuarine and coastal marine fishes. Elevated temperature and better trophic conditions had a positive effect on larval growth and developmental rates; warmer larval temperature had a delayed positive effect on body mass and resistance to hypoxia at the juvenile stage. The latter suggests a lower oxygen demand of individuals that had experienced elevated temperatures during larval stages. We hypothesize that an irreversible plastic response to temperature occurred during early ontogeny that allowed adaptive regulation of metabolic rates and/or oxygen demand with long-lasting effects. These results could deeply affect predictions about impacts of global warming and eutrophication on marine organisms. PMID:23486433

Zambonino-Infante, José L.; Claireaux, Guy; Ernande, Bruno; Jolivet, Aurélie; Quazuguel, Patrick; Sévère, Armelle; Huelvan, Christine; Mazurais, David

2013-01-01

231

Conditions?  

Microsoft Academic Search

Research interests in feral hogs typically involve their negative impacts on ecosystems or their potential as a disease reservoir, especially with disease transmission to domestic swine. Authors within scientific literature state that feral hogs were captured as part of their research, but usually fail to mention specific conditions in which hogs were captured. Novice researchers of feral hogs must rely

A. Christy Wyckoff; Scott E. Henke; Kurt C. VerCauteren

232

Autofluorescence of atmospheric bioaerosols - Biological standard particles and the influence of environmental conditions  

NASA Astrophysics Data System (ADS)

Primary biological aerosol particles (PBAP) such as pollen, fungal spores, bacteria, biogenic polymers and debris from larger organisms are known to influence atmospheric chemistry and physics, the biosphere and public health. PBAP can account for up to ~30% of fine and up to ~70% of coarse particulate matter in urban, rural and pristine environment and are released with estimated emission rates of up to ~1000 Tg/a [1]. Continuous measurements of the abundance, variability and diversity of PBAP have been difficult until recently, however. The application of on-line instruments able to detect autofluorescence from biological particles in real-time has been a promising development for the measurement of PBAP concentrations and fluxes in different environments [2,3]. The detected fluorescent biological aerosol particles (FBAP) can be regarded as a subset of PBAP, although the exact relationship between PBAP and FBAP is still being investigated. Autofluorescence of FBAP is usually a superposition of fluorescence from a mixture of individual fluorescent molecules (fluorophores). Numerous biogenic fluorophores such as amino acids (e.g., tryptophan, tyrosine), coenzymes (e.g., NAD(P)H, riboflavin) and biopolymers (e.g., cellulose) emit fluorescent light due to heterocyclic aromatic rings or conjugated double bonds within their molecular structures. The tryptophan emission peak is a common feature of most bioparticles because the amino acid is a constituent of many proteins and peptides. The influence of the coenzymes NAD(P)H and riboflavin on the autofluorescence of bacteria can be regarded as an indicator for bacterial metabolism and has been utilized to discriminate between viable and non-viable organisms [4]. However, very little information is available about other essential biofluorophores in fungal spores and pollen. In order to better understand the autofluorescence behavior of FBAP, we have used fluorescence spectroscopy and fluorescence microscopy to analyze standard bioparticles (pollen, fungal spores, and bacteria) as well as atmospherically relevant chemical substances. We addressed the sensitivity and selectivity of autofluorescence based online techniques. Moreover, we investigated the influence of environmental conditions, such as relative humidity and oxidizing agents in the atmosphere, on the autofluorescence signature of standard bioparticles. Our results will support the molecular understanding and quantitative interpretation of data obtained by real-time FBAP instrumentation [5,6]. [1] Elbert, W., Taylor, P. E., Andreae, M. O., & Pöschl, U. (2007). Atmos. Chem. Phys., 7, 4569-4588. [2] Huffman, J. A., Treutlein, B., & Pöschl, U. (2010). Atmos. Chem. Phys., 10, 3215-3233. [3] Pöschl, U., et al. (2010). Science, 329, 1513-1516. [4] Lakowicz, J., Principles of fluorescence spectroscopy, Plenum publishers, New York, 1999. [5] Pöhlker, C., Huffman, J. A., & Pöschl, U., (2012). Atmos. Meas. Tech., 5, 37-71. [6] Pöhlker, C., Huffman, J. A., Förster J.-D., & Pöschl, U., (2012) in preparation.

Pöhlker, Christopher; Huffman, J. Alex; Förster, Jan-David; Pöschl, Ulrich

2013-04-01

233

Modeling the effects of environmental conditions on HT2 and T2 toxin accumulation in field oat grains.  

PubMed

Fusarium head blight (FHB) of wheat and barley has been extensively researched worldwide; in contrast, there is limited information on the effects of environmental conditions on Fusarium toxin accumulation in oat grains. More than 300 samples of oat grain from various regions of the United Kingdom from 2006 to 2008 were analyzed for mycotoxin contamination due to infection by Fusarium spp. HT2 and T2 toxins were the two most commonly detected, and their concentrations in individual samples were highly correlated. Hourly weather data were obtained from meteorological recording stations near most of the sampling sites. Statistical modeling was applied to both the original toxin (HT2 plus T2) data and the toxin data adjusted for oat cultivars and number of cereal crops in the previous four seasons. Accumulation of HT2 and T2 toxin was positively correlated with warm and wet conditions during early May and dry conditions thereafter. Using a collection of 51 environmental variables summarized over three lengths (10, 15, and 20 days) of time periods encompassing early May, late May, and early July, all-subsets regression showed that many models, consisting of three to six predictor variables, could be identified with similar explanatory strength for the effect of environmental conditions on toxin accumulation. Most important predictor variables were related to wet conditions during the early-May period, which was before anthesis. These results suggest that the predominant period for Fusarium langsethiae infection of oat is likely to be before rather than during anthesis, as for other head blight pathogens. These empirical models may be further improved by using quantified pathogen biomass within the grains and weather predictor variables summarized in relation to plant growth stages (instead of calendar times). PMID:23883158

Xu, Xiangming; Madden, Laurence V; Edwards, Simon G

2014-01-01

234

ENVIRONMENTAL RESEARCH BRIEF: WASTE MINIMIZATION ASSESSMENT FOR A MANUFACTURER OF HEATING, VENTILATING, AND AIR CONDITIONING EQUIPMENT  

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small- and medium-size manufacturers who want to minimize their generation of hazardous waste but lack the expertise to do so. Waste Minimization Assessment Centers (WMACs) were established at sel...

235

40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.  

Code of Federal Regulations, 2012 CFR

...that may be used for simulating solar heat load are: (A) Metal...specifications. (i) Simulated solar radiant energy intensity is...every time major changes in the solar simulation hardware occur...testing. This applies to non-wind tunnel environmental test...

2012-07-01

236

40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.  

Code of Federal Regulations, 2011 CFR

...that may be used for simulating solar heat load are: (A) Metal...specifications. (i) Simulated solar radiant energy intensity is...every time major changes in the solar simulation hardware occur...testing. This applies to non-wind tunnel environmental test...

2011-07-01

237

40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.  

Code of Federal Regulations, 2010 CFR

...that may be used for simulating solar heat load are: (A) Metal...specifications. (i) Simulated solar radiant energy intensity is...every time major changes in the solar simulation hardware occur...testing. This applies to non-wind tunnel environmental test...

2010-07-01

238

ENVIRONMENTAL CONDITIONS IN NORTHERN GULF OF MEXICO COASTAL WATERS FOLLOWING HURRICANE KATRINA  

EPA Science Inventory

On the morning of August 29, 2005 Hurricane Katrina struck the coast of Louisiana, between New Orleans and Biloxi, Mississippi, as a strong category three hurricane on the Saffir-Simpson scale. The massive winds and flooding had the potential for a tremendous environmental impac...

239

Quorum-regulated biofilms enhance the development of conditionally viable, environmental Vibrio cholerae  

E-print Network

that is controlled by cell density. V. cholerae strains carrying mutations in genes required for quorum sensing suggest that a temporary loss of quorum sensing due to dilution of extracel- lular autoinducers confers viable environmental cells (CVEC) | quorum sensing | transmissibility of cholera Bacterial gene

Mekalanos, John

240

Effectiveness of current remote sensing systems for monitoring environmental conditions at US Army installations  

Microsoft Academic Search

The Pacific Northwest National Laboratory Remote Sensing Group and the U.S. Army at Fort Lewis Washington have been developing and applying customized remote sensing and GIS techniques to support environmental management activities at the Fort Lewis and Yakima Training Center (YTC) installations. This effort has evaluated imagery from all currently available satellite systems including LANDSAT, SPOT and RADARSAT as well

G. M. Petrie; G. E. Wukelic; R. W. Hanna

1998-01-01

241

Cultural and environmental factors governing tomato production: Local food production under elevated temperature conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Long-term fresh tomato (Solanum lycopersicum L.) production data was used to estimate cultural and environmental impacts on marketable tomato yields in eastern Oklahoma. Quantifying the interactive effects of planting date and growing season duration and the effects of cumulative heat units and heat...

242

Scale decisions can reverse conclusions on community assembly processes  

PubMed Central

Aim Phylogenetic diversity patterns are increasingly being used to better understand the role of ecological and evolutionary processes in community assembly. Here, we quantify how these patterns are influenced by scale choices in terms of spatial and environmental extent and organismic scales. Location European Alps. Methods We applied 42 sampling strategies differing in their combination of focal scales. For each resulting sub-dataset, we estimated the phylogenetic diversity of the species pools, phylogenetic ?-diversities of local communities, and statistics commonly used together with null models in order to infer non-random diversity patterns (i.e. phylogenetic clustering versus over-dispersion). Finally, we studied the effects of scale choices on these measures using regression analyses. Results Scale choices were decisive for revealing signals in diversity patterns. Notably, changes in focal scales sometimes reversed a pattern of over-dispersion into clustering. Organismic scale had a stronger effect than spatial and environmental extent. However, we did not find general rules for the direction of change from over-dispersion to clustering with changing scales. Importantly, these scale issues had only a weak influence when focusing on regional diversity patterns that change along abiotic gradients. Main conclusions Our results call for caution when combining phylogenetic data with distributional data to study how and why communities differ from random expectations of phylogenetic relatedness. These analyses seem to be robust when the focus is on relating community diversity patterns to variation in habitat conditions, such as abiotic gradients. However, if the focus is on identifying relevant assembly rules for local communities, the uncertainty arising from a certain scale choice can be immense. In the latter case, it becomes necessary to test whether emerging patterns are robust to alternative scale choices. PMID:24791149

Münkemüller, Tamara; Gallien, Laure; Lavergne, Sébastien; Renaud, Julien; Roquet, Cristina; Abdulhak, Sylvain; Dullinger, Stefan; Garraud, Luc; Guisan, Antoine; Lenoir, Jonathan; Svenning, Jens-Christian; Van Es, Jérémie; Vittoz, Pascal; Willner, Wolfgang; Wohlgemuth, Thomas; Zimmermann, Niklaus E.; Thuiller, Wilfried

2014-01-01

243

Influence of environmental temperatures on the concrete compressive strength: Simulation of hot and cold weather conditions  

Microsoft Academic Search

The objective of this work is to study the influence of mixing hour on the properties of concrete, such as workability and compressive strength, under hot and cold weather conditions, with a view to industrial application. The variable focused on was the concrete mixing hour, and five different mixing hours were used for each type of weather condition. Three batches

J. Ortiz; A. Aguado; L. Agulló; T. García

2005-01-01

244

Changes in body composition during breeding: Reproductive strategies of three species of seabirds under poor environmental conditions.  

PubMed

Seabirds differ dramatically in life history traits and breeding strategies. For example, gulls have short incubation shifts (several hours) and high metabolic rates, auks have medium-length incubation shifts (12-24h) and high metabolic rates, and petrels have long incubation shifts (days) and low metabolic rates. How these different strategies affect the dynamics of body components is poorly known. We compared body, organ and lipid mass changes among three different seabirds (gull: black-legged kittiwake Rissa tridactyla; auk: thick-billed murre Uria lomvia; petrel: northern fulmar Fulmarus glacialis) at Prince Leopold Island, Nunavut, Canada during 2002 (a year with low reproductive success and poor chick growth across all three species). This study is among the first to compare mass and lipid dynamics among different species foraging in the same food web and at similar trophic levels during the same breeding season (same environmental conditions). In fulmars and murres, most of decreases in body mass reflected decreases in lipid mass while in kittiwakes the increase in body mass reflected an increase in lean mass, especially the muscle. The species with the longest fasting endurance (incubation shift length) had the highest percent body lipids during incubation (fulmars: 13.3%, murres: 7.3%, kittiwakes: 6.9%), the highest variability in body lipids, tended to regulate body mass primarily through lipid stores and tended to regulate exercise and digestive organs separately. In contrast, in the species with the highest metabolic rate, all organ systems were adjusted similarly and in relation to body mass, and in a similar manner between incubation (stress due to heavy ice conditions) and chick-rearing (lower stress due to ice-free conditions). In high metabolic rate species, we suggest that organ size varies in response to environmental stress. We conclude that the organ dynamics of seabirds are set by a combination of key life history traits (like incubation shift and metabolic rate) and environmental conditions. PMID:20888927

Jacobs, Shoshanah R; Edwards, Darryl B; Ringrose, Julian; Elliott, Kyle H; Weber, Jean-Michel; Gaston, Anthony J

2011-01-01

245

Comparison of 905 nm and 1550 nm semiconductor laser rangefinders' performance deterioration due to adverse environmental conditions  

NASA Astrophysics Data System (ADS)

Laser rangefinder performance (i.e., maximum range) is strongly affected by environment due to visibility-dependent laser attenuation in the atmosphere and target reflectivity variations induced by surface condition changes (dry vs. wet). Both factors have their unique spectral features which means that rangefinders operating at different wavelengths are affected by specific environmental changes in a different way. Current state of the art TOF (time of flight) semiconductor laser rangefinders are based mainly on two wavelengths: 905 nm and 1550 nm, which results from atmospheric transmission windows and availability of high power pulsed sources. The paper discusses the scope of maximum range degradation of hypothetical 0.9 ?m and 1.5 ?m rangefinders due to selected water-related environmental effects. Atmospheric extinction spectra were adapted from Standard Atmosphere Model and reflectance fingerprints of various materials have been measured. It is not the aim of the paper to determine in general which wavelength is superior for laser range finding, since a number of criteria could be considered, but to verify their susceptibility to adverse environmental conditions.

Wojtanowski, J.; Zygmunt, M.; Kaszczuk, M.; Mierczyk, Z.; Muzal, M.

2014-09-01

246

Technical Note: Particulate reactive oxygen species concentrations and their association with environmental conditions in an urban, subtropical climate  

NASA Astrophysics Data System (ADS)

Reactions between hydrocarbons and ozone or hydroxyl radicals lead to the formation of oxidized species, including reactive oxygen species (ROS), and secondary organic aerosol (SOA) in the troposphere. ROS can be carried deep into the lungs by small aerodynamic particles where they can cause oxidative stress and cell damage. While environmental studies have focused on ROS in the gas phase and rainwater, it is also important to determine concentrations of ROS on respirable particles. Samples of PM2.5 collected over 3 h at midday on 40 days during November 2011 and September 2012 show that the particulate ROS concentration in Austin, Texas, ranged from a minimum value of 0.02 nmoles H2O2 m-3 air in December to 3.81 nmoles H2O2 m-3 air in September. Results from correlation tests and linear regression analysis on particulate ROS concentrations and environmental conditions (which included ozone and PM2.5 concentrations, temperature, relative humidity, precipitation and solar radiation) indicate that ambient particulate ROS is significantly influenced by the ambient ozone concentration, temperature and incident solar radiation. Particulate ROS concentrations measured in this study were in the range reported by other studies in the US, Taiwan and Singapore. This study is one of the first to assess seasonal variations in particulate ROS concentrations and helps explain the influence of environmental conditions on particulate ROS concentrations.

Khurshid, S. S.; Siegel, J. A.; Kinney, K. A.

2014-07-01

247

The influence of environmental conditions on polysaccharide formation by Ganoderma lucidum in submerged cultures  

Microsoft Academic Search

The effects of environmental parameters on polysaccharide formation by Ganoderma lucidum were investigated in submerged cultures. The optimal temperature and pH was 30–35°C and 4–4·5, respectively, in a glucose-ammonium chloride medium and polysaccharide concentration reached 1·6 mg\\/ml. Agitation and aeration influenced the formation and secretion of polysaccharide. The optimal rotating speed was 150 rpm in 7-day flask cultures, while the

Fan-Chiang Yang; Chun-Bun Liau

1998-01-01

248

Environmental Conditions in northern Gulf of Mexico Estuaries: before and after the BP Oil Spill  

EPA Science Inventory

This presentation provides a summary of ecological condition and sediment chemistry data for northern Gulf of Mexico estuaries that were exposed to oil and oil-related contaminants from the BP Oil Spill. ...

249

MEASURES OF GENETIC DIVERSITY ARE EFFECTIVE TOOLS FOR EVALUATING ENVIRONMENTAL CONDITION  

EPA Science Inventory

At their core, ecological risk assessments aim to evaluate the biological integrity and long-term sustainability of natural ecosystems. These are difficult objectives that will ultimately require development of novel indicators of ecological condition that are more accurate and ...

250

Transcriptional response of Desulfovibrio vulgaris Hildenborough to oxidative stress mimicking environmental conditions  

Microsoft Academic Search

Sulfate-reducing bacteria (SRB) are anaerobes readily found in oxic–anoxic interfaces. Multiple defense pathways against oxidative\\u000a conditions were identified in these organisms and proposed to be differentially expressed under different concentrations of\\u000a oxygen, contributing to their ability to survive oxic conditions. In this study, Desulfovibrio vulgaris Hildenborough cells were exposed to the highest concentration of oxygen that SRB are likely to

Patrícia M. Pereira; Qiang He; António V. Xavier; Jizhong Zhou; Inês A. C. Pereira; Ricardo O. Louro

2008-01-01

251

The effects of early environmental conditions on the reproductive and somatic development of juvenile guinea pigs (Cavia aperea f. porcellus)  

PubMed Central

Little is known about the effects of the early environment on the development of non-seasonally reproducing species like the domestic guinea pig (Cavia aperea f. porcellus). Although guinea pigs reproduce throughout the year, there is evidence for environmental sensitivity of their reproductive physiology. To investigate the sensitivity of juvenile body weight and puberty to differences in the prenatal and early postnatal environment, subjects were exposed to either of two experimental conditions mimicking seasonal variation: a long photoperiod with 25 °C ambient temperature (“LD/25 °C”), or a short photoperiod with 15 °C (“SD/15 °C”). Mean body weight of F1-males from LD/25 °C-conditions was higher than that of SD/15 °C-males during the whole pubertal period, although the difference was significant only during the early growth phase. Testosterone concentrations also differed significantly between the two treatment groups, pointing to an earlier pubertal onset in LD/25 °C- than SD/15 °C-males. In F1-females, treatment effects on body weight or age at first estrus were absent. This indicates that the somatic and reproductive development is more sensitive to early photoperiod and temperature conditions in male than female guinea pigs, and that other environmental factors may also play a crucial role for reproductive maturation in this species. PMID:17977535

Bauer, Barbara; Womastek, Irene; Dittami, John; Huber, Susanne

2011-01-01

252

Robust Vehicle Detection under Various Environmental Conditions Using an Infrared Thermal Camera and Its Application to Road Traffic Flow Monitoring  

PubMed Central

We have already proposed a method for detecting vehicle positions and their movements (henceforth referred to as “our previous method”) using thermal images taken with an infrared thermal camera. Our experiments have shown that our previous method detects vehicles robustly under four different environmental conditions which involve poor visibility conditions in snow and thick fog. Our previous method uses the windshield and its surroundings as the target of the Viola-Jones detector. Some experiments in winter show that the vehicle detection accuracy decreases because the temperatures of many windshields approximate those of the exterior of the windshields. In this paper, we propose a new vehicle detection method (henceforth referred to as “our new method”). Our new method detects vehicles based on tires' thermal energy reflection. We have done experiments using three series of thermal images for which the vehicle detection accuracies of our previous method are low. Our new method detects 1,417 vehicles (92.8%) out of 1,527 vehicles, and the number of false detection is 52 in total. Therefore, by combining our two methods, high vehicle detection accuracies are maintained under various environmental conditions. Finally, we apply the traffic information obtained by our two methods to traffic flow automatic monitoring, and show the effectiveness of our proposal. PMID:23774988

Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

2013-01-01

253

Relating coral species traits to environmental conditions in the Jakarta Bay/Pulau Seribu reef system, Indonesia  

NASA Astrophysics Data System (ADS)

A key question in ecology is how biological traits of species determine their locations within an ecosystem. Identifying associations between species traits and environmental variables can help us to understand the causes of disturbance and predict whether species with given traits will persist under changing environmental conditions. To this end corals and environmental variables were sampled in 20 patch reefs of Pulau Seribu, located to the northwest of Jakarta, Indonesia. RLQ analysis, a multivariate ordination approach was subsequently used to relate species traits (colony shape, colony form, corallite size, reproductive mode and adaptive strategy) to environmental variables (e.g., heavy metal concentration in seawater and sediment, salinity, dissolved oxygen, and the cover of sand, dead coral, algae, sponges and soft corals). Using RLQ analysis, we identified environmental gradients associated with significant variation in species traits. Stress tolerant species with a massive morphology, meandroid shape and large corallites were associated with sites with a high abundance of algae and a relatively high concentration of potentially toxic heavy metals in seawater including Cu and Cd, whereas ruderal species and species with a branching morphology and very small corallites were linked to midshore sites. Competitively dominant species with a laminar or free-living morphology, phaceloid shape, very large corallites and brooding reproductive mode were linked to offshore sites with abundant Ca and Sr in the sediment and a high cover of Halimeda algae and sponges. Results of this study indicate that disturbance has differentially affected the marine environment of the Pulau Seribu system, which in turn interacts with coral species traits to determine local species composition.

Rachello-Dolmen, P. G.; Cleary, D. F. R.

2007-07-01

254

Visible/Near-Infrared Hyperspectral Sensing of Solids under Controlled Environmental Conditions  

SciTech Connect

We describe the use of a wind tunnel for conducting controlled passive hyperspectral imaging experiments. Passive techniques are potentially useful for detecting explosives, solid-phase chemicals and other materials of interest from a distance so as to provide operator safety. The Pacific Northwest National Laboratory operates a wind tunnel facility that can generate and circulate artificial atmospheres to control lighting, humidity, temperature, aerosol burdens, and obscurants. We will present recent results describing optimized sensing of solids over tens of meters distance using both visible and near-infrared cameras, as well as the effects of certain environmental parameters on data retrieval.

Bernacki, Bruce E.; Anheier, Norman C.; Mendoza, Albert; Fritz, Brad G.; Johnson, Timothy J.

2011-06-01

255

Section 3, Component 3: Control of Environmental Factors and Comorbid Conditions That Affect Asthma August 28, 2007  

E-print Network

Section 3, Component 3: Control of Environmental Factors and Comorbid Conditions That Affect Asthma THAT AFFECT ASTHMA K E Y P O I N T S : C O N T R O L O F E N V I R O N M E N T A L F A C T O R S A N D C O M O R B I D C O N D I T I O N S T H A T A F F E C T A S T H M A Exposure of patients who have asthma

Levin, Judith G.

256

Determination of Storm Flashing/Non-Flashing Condition From Convective and Environmental Observations  

NASA Technical Reports Server (NTRS)

A simple and fundamental problem in cloud electrification is whether or not a cloud can be determined to be producing lightning or not producing lightning, based solely on knowledge of its microphysical (and perhaps environmental) state. A merged database of TRMM radar, microwave and lightning observations and NCEP reanalysis environmental parameters is used to answer this question, for the tropics. The formal skill of traditional, univariate rule-based approaches (e.g., 35 dBZ occurrence at 6 km altitude) is quantified (via the probability of detection (POD), false alarm rate (FAR) and critical skill index (CSI)). Under indiscriminate application to the tropics, peak rule-based CSI for categorization of flashing storms is approximately 50%, with peak POD approximately 67% and minimum FAR approximately 33%, with peak CSI found for radar reflectivity-based parameters at 7-7.5 km altitude (near -15C). Separation of land and ocean domains yields approximately 5-10% gains in CSI over land. Conventional multivariate categorization techniques (discriminant analysis) are then applied, and less conventional (neural network) categorization techniques are also discussed.

Boccippio, Dennis J.

2002-01-01

257

The effect of three environmental conditions on the fitness of cytochrome P450 monooxygenase-mediated permethrin resistance in Culex pipiens quinquefasciatus  

PubMed Central

Background The evolution of insecticide resistance and persistence of resistance phenotypes are influenced by the fitness of resistance alleles in the absence of insecticide pressure. Experimental determination of fitness is difficult, but fitness can be inferred by measuring changes in allele frequencies in appropriate environments. We conducted allele competition experiments by crossing two highly related strains of Culex pipiens quinquefasciatus mosquitoes. One strain (ISOP450) was permethrin resistant (due to P450-mediated detoxification) and one was a susceptible strain. Allele and genotype frequencies were examined for 12 generations under three environmental conditions: standard laboratory, temephos exposure (an insecticide to which the P450 detoxification mechanism in ISOP450 confers no resistance and which is commonly used in mosquito control programs) and cold temperature stress (mimics the colder temperatures within the habitat of this mosquito). Results A fitness cost was inferred for the P450 mechanism in the standard laboratory environment. A greater cost was associated with the temephos exposed environment, suggesting the temephos placed an additional stress on the P450 resistant mosquitoes. No observed cost was associated with the P450 resistance locus in the cold temperature environment, but there was a significant heterozygote advantage. In all environments the fitness of the resistant homozygotes was the lowest. Conclusion The cytochrome P450-mediated permethrin detoxification resistance in Cx. p. quinquefasciatus can have an associated fitness cost in the absence of permethrin, relative to a susceptible allele. The strength of the cost varies depending on the environmental conditions. P450-mediated resistance is expected to decrease over time if the permethrin application is relaxed and to decrease at an even faster rate if permethrin is replaced with temephos. Additionally, these results indicate that a P450 resistance allele can persist (especially in heterozygotes) in colder temperatures and could potentially be carried into the Culex pipiens hybrid zone. PMID:19228410

Hardstone, Melissa C; Lazzaro, Brian P; Scott, Jeffrey G

2009-01-01

258

Evaluation of contact heat thermal threshold testing for standardized assessment of cutaneous nociception in horses - comparison of different locations and environmental conditions  

PubMed Central

Background The aim of the study was to evaluate the performance of contact heat thermal stimulation in horses at different body sites and under different environmental conditions and different test situations. Five warm-blood horses were equipped with the thermal probe located on the skin of nostril (N), withers (W) or coronary band (C). Skin temperature and reaction temperature (thermal threshold) at each location were measured and percent thermal excursion (% TE?=?100 * (threshold temperature - skin temperature)/(cut-out temperature - skin temperature) was calculated. Environmental conditions were changed in partial random order for all locations, so each horse was tested in its familiar box stall and stocks, in the morning and evening and at warm and cold ambient temperatures. Type of reaction to the stimulus and horse’s general behaviour during stimulation were recorded. The stimulation sites were examined for the occurrence of possible skin lesions. Results Skin temperatures were significantly different during warm and cold ambient temperatures at all three locations, but remained constant over repeated stimulation. An obvious response to stimulation before reaching cut-out temperature could be detected most frequently at N and W in boxes during warm ambient temperatures. The most frequent type of reaction to thermal stimulation at the nostril was headshaking (64.6%), skin twitching at the withers (82.9%) and hoof withdrawal at the coronary band (79.2%). Conclusion The outcome of thermal threshold testing depended on ambient temperature, stimulation site and environment. Best results with the WTT2 in horses were obtained at the nostrils or withers in a familiar environment at warm ambient temperatures. PMID:23298405

2013-01-01

259

Emissions and environmental impacts from air-conditioning and refrigeration systems  

Microsoft Academic Search

The impacts of air conditioning and refrigeration systems on stratospheric ozone are primarily linked to release of ozone-depleting refrigerants. Their contributions to global warming stem both from release of refrigerants and from emission of greenhouse gases (GHGs) for associated energy use. Because the energy-related component has a significantly higher warming impact, phaseout of hydrofluorocarbon (HFC) refrigerants with less efficient options

James M. Calm

2002-01-01

260

The effect of early environmental manipulation on locomotor sensitivity and methamphetamine conditioned place preference reward.  

PubMed

Early life stress leads to several effects on neurological development, affecting health and well-being later in life. Instances of child abuse and neglect are associated with higher rates of depression, risk taking behavior, and an increased risk of drug abuse later in life. This study used repeated neonatal separation of rat pups as a model of early life stress. Rat pups were either handled and weighed as controls or separated for 180 min per day during postnatal days 2-8. In adulthood, male and female rats were tested for methamphetamine conditioned place preference reward and methamphetamine induced locomotor activity. Tissue samples were collected and mRNA was quantified for the norepinephrine transporter in the prefrontal cortex and the dopamine transporter in the nucleus accumbens. Results indicated rats given methamphetamine formed a conditioned place preference, but there was no effect of early separation or sex. Separated males showed heightened methamphetamine-induced locomotor activity, but there was no effect of early separation for females. Overall females were more active than males in response to both saline and methamphetamine. No differences in mRNA levels were observed across any conditions. These results suggest early neonatal separation affects methamphetamine-induced locomotor activity in a sex-dependent manner but has no effects on methamphetamine conditioned place preference. PMID:24713150

Hensleigh, E; Pritchard, L M

2014-07-15

261

The role of genotypic diversity in determining grassland community structure under constant environmental conditions  

Microsoft Academic Search

Summary 1. A recent experiment varied the genetic diversity of model grassland communities under standardized soil and management conditions and at constant initial species diversity. After 5 years' growth, genetically diverse communities retained more species diversity and became more similar in species composition than genetically impover- ished communities. 2. Here we present the results of further investigation within this experimental

RAJ WHITLOCK; J. PHILIP GRIME; ROSEMARY BOOTH; TERRY BURKE

2007-01-01

262

An assessment of environmental conditions for control of downy brome by Pseudomonas fluorescens D7  

Technology Transfer Automated Retrieval System (TEKTRAN)

Purpose: We evaluated the conditions that favoured Pseudomonas fluorescens strain D7 (P.f. D7) growth and inhibition of downy brome. Design/methodology/approach: Tn5 mutagenesis and a competitive assay were used to isolate mutants of P.f. D7. Isolates were screened for polysaccharide production and ...

263

TOXICITY OF PENTACHLOROPHENOL TO AQUATIC ORGANISMS UNDER NATURALLY VARYING AND CONTROLLED ENVIRONMENTAL CONDITIONS  

EPA Science Inventory

The toxicity of pentachlorophenol (PCP) was determined in the laboratory for 11 aquatic species. Tests were conducted seasonally in ambient Mississippi River water and under controlled conditions in Lake Superior water. Fifty-one acute toxicity tests were conducted, with LC50 val...

264

Role of Environmental Conditions on the Interaction of L-Arginine with Oxide Mineral Surfaces  

NASA Astrophysics Data System (ADS)

The current study is focused on surface interactions between L-arginine, the most basic protein amino acid, and rutile in NaCl media over a wide range of solution pH conditions, amino acid concentrations, and solution ionic strengths.

Klochko, K.; Jonsson, C. M.; Jonsson, C. L.; Lee, N.; Cleaves, H. J., II; Sverjensky, D. A.; Hazen, R. M.

2010-04-01

265

Dehydration Kinetics of Pharmaceutical Hydrate: Effects of Environmental Conditions and Crystal Forms  

Microsoft Academic Search

The present study was conducted to investigate the influence of drying condition (atmospheric pressure with varying temperature, acetone vapor-induced environment, and vacuum pressure) on the dehydration kinetics of carbamazepine dihydrate. Samples were prepared in loose crystals and agglomerated forms. Increasing driving forces, that is, higher temperature (up to 60°C), low vacuum pressure (10 Torr), and the presence of acetone vapor pressure

Ji Yi Khoo; Daryl R. Williams; Jerry Y. Y. Heng

2010-01-01

266

Effects of the environmental conditions on the mechanical behaviour of the corrugated cardboard  

Microsoft Academic Search

Corrugated cardboard is very sensitive to atmospheric conditions. The aim of this work is to study the effects of these parameters, in fact the relative humidity (RH), on the mechanical behaviour of a sandwich structure of the corrugated cardboard type. For that, tensile tests were used under various rates of relative humidity. In high rates of moisture, the instrumentation must

S. Allaoui; Z. Aboura; M. L. Benzeggagh

2009-01-01

267

LEVEL OF SOMATIC DEVELOPMENT OF CHILDREN AGED SIX YEARS FROM AN URBAN AGGLOMERATION IN POLAND WITH RESPECT TO SELECTED ENVIRONMENTAL CONDITIONS.  

PubMed

Summary The aim of this study was to assess the somatic development of children from an urban agglomeration in Poland at the end of preschool education and the beginning of primary education with respect to selected socioeconomic and educational conditions. Data were collected for 742 children from selected Warsaw kindergartens in spring 2011 and 2012. Their mean age was 5.84±0.31 years. The sex categories were equal: 371 boys and 371 girls. Kindergartens chosen for the study constituted a representative sample. The diagnostic survey method (questionnaire technique) was used to assess the selected environmental conditions of development in the participating children. Body height and the sum of six skin folds (over the biceps, over the triceps, under the scapula, on the abdomen, over the wing of ilium and on the calf) were chosen from the assessed anthropometric parameters for the purpose of determining somatic development of study participants. The obtained data were analysed using selected descriptive statistics methods (including cluster analysis), data standardization (normalization by mean values and SD) and the chi-squared test. The results showed certain relationships between the selected parameters of somatic development and family living conditions. These relationships involved differences between individual clusters depending on given living conditions and were most prominent for mother's education, for which variable differences between clusters were found for both sexes. The somatic build of boys (including body height and body adiposity) also differed depending on the number of offspring in the family, while the somatic build of girls differed depending on father's employment and father's education. Furthermore, the obtained results lead to the conclusion that the total number of differences between the analysed clusters was relatively low. This indicates that the biological effects of social stratification tend to diminish in the environment of an urban agglomeration. PMID:25392125

Trzci?ska, Dorota; Tabor, Piotr; Olszewska, El?bieta

2014-11-13

268

Lifetime of Poly(triaryl amine) Based Organic Field Effect Transistors under Different Environmental Conditions  

NASA Astrophysics Data System (ADS)

Characterization of reliability and lifetime is a key issue on the way to commercialization of products based on organic electronics. Prediction of the lifetime requires the understanding of failure mechanisms and the circumstances leading to failure. In this work the stability of poly(triaryl amine) (PTAA) based organic field effect transistors (OFETs) on a poly(ethylene naphthalate) (PEN) substrate is investigated under environmental stressing. PTAA is known to form amorphous thin films after spin coating and to be air stable for extended periods of time. This inherent air stability makes it a good candidate for testing of environmental influences. The samples were electrically characterized regularly between storage cycles at 85 °C and 85 °C/85% relative humidity (RH). Samples stored under dry atmosphere and inert gas were used as reference. More than 1700 OFETs were produced in multiple batches and measured using an automated measurement system to collect statistically significant data. Circuit-relevant OFET parameters such as on- and off-current, mobility, threshold voltage and gate leakage current were extracted applying a thin film transistor (TFT) device model to the measured transfer and output curves. The threshold voltage is found to be the most sensitive parameter especially for the samples stored at 85 °C. The effect of storage under 85 °C/85%RH is observed to be comparably small. Fourier transform infrared (FT-IR) measurements of the aged OFET samples indicate a correlation between the shift of the electrical parameters and the appearance of carbonyl groups in the dielectric layer of the devices. Possible degradation mechanisms are discussed based on this observation.

Lau, Tobias; Lorenz, Enno; Koyuncu, Metin

2013-04-01

269

Abundance of broad bacterial taxa in the sargasso sea explained by environmental conditions but not water mass.  

PubMed

To explore the potential linkage between distribution of marine bacterioplankton groups, environmental conditions, and water mass, we investigated the factors determining the abundance of bacterial taxa across the hydrographically complex Subtropical Convergence Zone in the Sargasso Sea. Based on information from 16S rRNA gene clone libraries from various locations and two depths, abundances of the predominant taxa (eubacteria, Archaea, Alphaproteobacteria, Gammaproteobacteria, Bacteroidetes, and the Roseobacter, SAR11, and SAR86 clades) were quantified by real-time PCR. In addition, the abundances of Synechococcus, Prochlorococcus, and picoalgae were determined by flow cytometry. Linear multiple-regression models determining the relative effects of eight environmental variables and of water mass explained 35 to 86% of the variation in abundance of the quantified taxa, even though only one to three variables were significantly related to any particular taxon's abundance. Most of the variation in abundance was explained by depth and chlorophyll a. The predominant phototrophs, Prochlorococcus and picoalgae, were negatively correlated with phosphate, whereas eubacteria, heterotrophic bacteria, and SAR86 were negatively correlated with nitrite. Water mass showed limited importance for explaining the abundance of the taxonomical groups (significant only for Roseobacter, explaining 14% of the variation). The results suggest the potential for predicting the abundance of broad bacterioplankton groups throughout the Sargasso Sea using only a few environmental parameters. PMID:24561593

Sjöstedt, Johanna; Martiny, Jennifer B H; Munk, Peter; Riemann, Lasse

2014-05-01

270

Biological and Environmental Initial Conditions Shape the Trajectories of Cognitive and Social-Emotional Development across the First Years of Life  

ERIC Educational Resources Information Center

Human development is thought to evolve from the dynamic interchange of biological dispositions and environmental provisions; yet the effects of specific biological and environmental birth conditions on the trajectories of cognitive and social-emotional growth have rarely been studied. We observed 126 children at six time-points from birth to 5…

Feldman, Ruth; Eidelman, Arthur I.

2009-01-01

271

[Fundamentals of socio-hygienic monitoring of environmental conditions for students of higher education schools].  

PubMed

Socioeconomic transformations and the poor environment of an industrial megalopolis negatively affected quality of life and morbidity rates in students (n = 2160). Academic intensity contributed to an increase in overall morbidity and morbidity from nervous system involvement. The regional sociohygienic monitoring of high-school training conditions within the framework of the surveillance system substantiates programs to prevent worse health and life quality in high school students. PMID:22712322

Blinova, E G; Kuchma, V R

2012-01-01

272

Analysis of the Salmonella typhimurium Proteome through Environmental Response toward Infectious Conditions  

Microsoft Academic Search

Salmonella enterica serovar Typhimurium (aka, S. typhimurium) is a facultative intracellular pathogen that causes ~40,000 reported cases of acute gastroenteritis and diarrhea a year in the United States. To develop a deeper understanding of the infectious state of S. typhimurium, liquid chromatography-mass spectrometry-based âbottom-up❠proteomics was used to globally analyze the proteins present under specific growth conditions. Salmonella typhimurium LT2

Joshua N. Adkins; Heather M. Mottaz; Angela D. Norbeck; Jean K. Gustin; Joanne Rue; Therese R. W. Clauss; Samuel O. Purvine; Karin D. Rodland; Fred Heffron; Richard D. Smith

2006-01-01

273

Effect of Environmental Conditions on Growth of Alternaria alternata Causing Leaf Blight of Noni  

Microsoft Academic Search

Effect of different pH levels, temperature, light intensity and media were tested against the growth of A. alternata under in vitro conditions. The results of experiment indicated that the growth of A. alternata was maximum in pH range of 6.00- 6.50 and temperature range of 25 - 30°C. The exposure of the fungus to alternate cycles of 12 hour light

Manjunath Hubballi; Sevugapperumal Nakkeeran; Thiruvengadam Raguchander; Theerthagiri Anand; Ramasamy Samiyappan

2010-01-01

274

Improving Casuarina growth and symbiosis with Frankia under different soil and environmental conditions—review  

Microsoft Academic Search

Casuarinas are very important plants for their various uses and survival in adverse sites or harsh environments. As nitrogen\\u000a fixation, in symbiosis with Frankia, is an important factor for the survival of these plants under various conditions, the basis for selecting both effective\\u000a and tolerant Frankia strains and Casuarina spp., are provided. Enhancement of the symbiotic relationship between Frankia and

W. F. Sayed

2011-01-01

275

Biodegradation of aged diesel in diverse soil matrixes: impact of environmental conditions and bioavailability on microbial remediation capacity.  

PubMed

While bioremediation of total petroleum hydrocarbons (TPH) is in general a robust technique, heterogeneity in terms of contaminant and environmental characteristics can impact the extent of biodegradation. The current study investigates the implications of different soil matrix types (anthropogenic fill layer, peat, clay, and sand) and bioavailability on bioremediation of an aged diesel contamination from a heterogeneous site. In addition to an uncontaminated sample for each soil type, samples representing two levels of contamination (high and low) were also used; initial TPH concentrations varied between 1.6 and 26.6 g TPH/kg and bioavailability between 36 and 100 %. While significant biodegradation occurred during 100 days of incubation under biostimulating conditions (64.4-100 % remediation efficiency), low bioavailability restricted full biodegradation, yielding a residual TPH concentration. Respiration levels, as well as the abundance of alkB, encoding mono-oxygenases pivotal for hydrocarbon metabolism, were positively correlated with TPH degradation, demonstrating their usefulness as a proxy for hydrocarbon biodegradation. However, absolute respiration and alkB presence were dependent on soil matrix type, indicating the sensitivity of results to initial environmental conditions. Through investigating biodegradation potential across a heterogeneous site, this research illuminates the interplay between soil matrix type, bioavailability, and bioremediation and the implications of these parameters for the effectiveness of an in situ treatment. PMID:23242513

Sutton, Nora B; van Gaans, Pauline; Langenhoff, Alette A M; Maphosa, Farai; Smidt, Hauke; Grotenhuis, Tim; Rijnaarts, Huub H M

2013-07-01

276

Cytoprotective Effect of Short-Term Pretreatment with Proanthocyanidin on Human Gingival Fibroblasts Exposed to Harsh Environmental Conditions  

PubMed Central

Our previous study showed that exposing mouse fibroblasts to proanthocyanidin (PA) for only 1 min accelerated cell proliferation in a concentration-dependent manner. In this study, exposing human gingival fibroblasts (HGFs) to PA for 1 min similarly accelerated the proliferative response of the cells. Besides the accelerated proliferative response, PA showed a cytoprotective effect on HGFs exposed to harsh environmental conditions; short-term exposure of HGFs in the mitotic phase to pure water or physiological saline resulted in a lower recovery of viable cells. Pretreatment and concomitant treatment with PA improved the low recovery of cells exposed to pure water or physiological saline. In addition, HGFs exposed to PA for 1 min proliferated well even after being cultured in serum-free medium. In 100% confluent HGFs, being cultured in serum-free medium resulted in a high intracellular reactive oxygen species (ROS) level, but pretreatment with PA prevented the cells from increasing intracellular ROS. Thus, the results suggest that a short-term PA treatment exerts cytoprotective effects on HGFs exposed to harsh environmental conditions by improving the intracellular oxidative stress response. PMID:25405354

Kurauchi, Michiko; Niwano, Yoshimi; Shirato, Midori; Kanno, Taro; Nakamura, Keisuke; Egusa, Hiroshi; Sasaki, Keiichi

2014-01-01

277

Variations of vessel diameter and ?13C in false rings of Arbutus unedo L. reflect different environmental conditions.  

PubMed

Woody species in Mediterranean ecosystems form intra-annual density fluctuations (IADFs) in tree rings in response to changes in environmental conditions, especially water availability. Dendrochronology, quantitative wood anatomy and high-resolution isotopic analysis (using a laser ablation technique) were used to characterize IADFs in Arbutus unedo shrubs grown on two sites with different water availability on the island of Elba (Italy). Our findings show that IADF characterization can provide information about the relationship between environmental factors and tree growth at the seasonal level. At the more xeric site, IADFs mainly located in the early and middle parts of the annual ring, showed a decrease in vessel size and an increase in ?(13) C as a result of drought deficit. Opposite trends were found at the more mesic site, with IADFs located at the end of the ring and associated with a lower ?(13) C. Moreover, at the first site, IADFs are induced by drought deficit, while at the second site IADFs are linked with the regrowth in the last part of the growing season triggered by favourable wet conditions. This combined approach is a promising way for dating problematic wood samples and interpreting the phenomena that trigger the formation of IADFs in the Mediterranean environment. PMID:20840507

Battipaglia, Giovanna; De Micco, Veronica; Brand, Willi A; Linke, Petra; Aronne, Giovanna; Saurer, Matthias; Cherubini, Paolo

2010-12-01

278

Evaluation of the performance characteristics of bilayer tablets: Part II. Impact of environmental conditions on the strength of bilayer tablets.  

PubMed

Ambient air humidity and temperature are known to influence the mechanical strength of tablets. The objective of this work is to understand the influence of processing parameters and environmental conditions (humidity and temperature) on the strength of bilayer tablets. As part of this study, bilayer tablets were compressed with different layer ratios, dwell times, layer sequences, material properties (plastic and brittle), first and second layer forces, and lubricant concentrations. Compressed tablets were stored in stability chambers controlled at predetermined conditions (40C/45%RH, 40C/75%RH) for 1, 3, and 5 days. The axial strength of the stored tablets was measured and a statistical model was developed to determine the effects of the aforementioned factors on the strength of bilayer tablets. As part of this endeavor, a full 3?×?2(4) factorial design was executed. Responses of the experiments were analyzed using PROC GLM of SAS (SAS Institute Inc, Cary, North Carolina, USA). A model was fit using all the responses to determine the significant interactions (p?conditions and storage time have significant impact on the strength of bilayer tablets. For Avicel-lactose and lactose-Avicel tablets, tablet strength decreased with the increasing humidity and storage time. But for lactose-lactose tablets, due to the formation of solid bridges upon storage, an increase in tablet strength was observed. Significant interactions were observed between processing parameters and storage conditions on the strength of bilayer tablets. PMID:22965660

Kottala, Niranjan; Abebe, Admassu; Sprockel, Omar; Bergum, James; Nikfar, Faranak; Cuitiño, Alberto M

2012-12-01

279

Environmental Conditions around Itineraries to Destinations as Correlates of Walking for Transportation among Adults: The RECORD Cohort Study  

PubMed Central

Introduction Assessing the contextual factors that influence walking for transportation is important to develop more walkable environments and promote physical activity. To advance previous research focused on residential environments and overall walking for transportation, the present study investigates objective environmental factors assessed around the residence, the workplace, the home – work itinerary, and the home – supermarket itinerary, and considered overall walking for transportation but also walking to work and to shops. Methods Data from the RECORD Study involving 7290 participants recruited in 2007–2008, aged 30–79 years, and residing in the Paris metropolitan area were analyzed. Multilevel ordinal regression analyses were conducted to investigate environmental characteristics associated with self-reported overall walking for transportation, walking to work, and walking to shops. Results High individual education was associated with overall walking for transportation, with walking to work, and walking to shops. Among workers, a high residential neighborhood education was associated with increased overall walking for transportation, while a high workplace neighborhood education was related to an increased time spent walking to work. The residential density of destinations was positively associated with overall walking for transportation, with walking to work, and with walking to shops, while the workplace density of destinations was positively associated with overall walking for transportation among workers. Environmental factors assessed around the itineraries were not associated with walking to work or to the shops. Conclusion This research improves our understanding of the role of the environments on walking for transportation by accounting for some of the environments visited beyond the residential neighborhood. It shows that workers' walking habits are more influenced by the density of destinations around the workplace than around the residence. These results provide insight for the development of policies and programs to encourage population level active commuting. PMID:24828890

Karusisi, Noëlla; Thomas, Frédérique; Méline, Julie; Brondeel, Ruben; Chaix, Basile

2014-01-01

280

Effects of environmental conditions on SSC resistance of C125 OCTG  

SciTech Connect

Demand for high strength casing has increased to develop high pressure and/or deep wells. In order to cope with H{sub 2}S contained in produced fluid, the high strength casings are often required to be resistant to SSC (Sulfide Stress Cracking). Effects of environmental factors such as H{sub 2}S partial pressure and pH on SSC resistance of C125 grade OCTG were made clear using some types of SSC tests (tensile, V-notched 4-point bent beam, DC13 compact, tension, SSRT) and a hydrogen permeation test. For hydrogen entry into steel, one unit of pH decline is equivalent to a tenfold rise of H{sub 2}S partial pressure although the effect of pH becomes lower after long time. SSC resistance of C125 decreases with increasing pH{sub 2}S and decreasing pH and is very high at H{sub 2}S partial pressure of 0.001 MPa or lower and high at 0.01 MPa in case of higher pH.

Asahi, H.; Nose, K. [Nippon Steel Corp., Futtsushi, Chiba (Japan). Steel Research Labs.

1999-11-01

281

Environmental conditions during early life determine the consequences of inbreeding in Agrostemma githago (Caryophyllaceae).  

PubMed

In an inbred population, selection may reduce the frequency of deleterious recessive alleles through a process known as purging. Empirical studies suggest, however, that the efficacy of purging in natural populations is highly variable. This variation may be due, in part, to variation in the expression of inbreeding depression available for selection to act on. This experiment investigates the roles of life stage and early-life environment in determining the expression of inbreeding depression in Agrostemma githago. Four population-level crosses ('self', 'within', 'near' and 'far') were conducted on 20 maternal plants from a focal population. Siblings were planted into one of three early environmental treatments with varying stress levels. Within the focal population, evidence for purging of deleterious recessive alleles, as well as for variation in the expression of inbreeding depression across the life cycle was examined. In addition, the effect of early environment on the expression of inbreeding depression and the interaction with cross-type was measured. We find that deleterious recessive alleles have not been effectively purged from our focal population, the expression of inbreeding depression decreases over the course of the life cycle, and a stressful early environment reduces the variance in inbreeding depression expressed later in life, but does not consistently influence the relative fitness of inbred versus outcrossed individuals. PMID:23294449

Goodrich, S H; Beans, C M; Roach, D A

2013-03-01

282

Dynamic balance of multiple myeloma clonogenic side population cell percentages controlled by environmental conditions.  

PubMed

Cancer stem cells are key drivers of tumor progression and disease recurrence in multiple myeloma (MM). However, little is known about the regulation of MM stem cells. Here, we show that a population of MM cells, known as the side population (SP), exhibits stem-like properties. Cells that constitute the SP in primary MM isolates are negative or seldom expressed for CD138 and CD20 markers. In addition, the SP population contains stem cells that belong to the same lineage as the mature neoplastic plasma cells. Importantly, our data indicate that the SP and nonside population (NSP) percentages in heterogeneous MM cells are balanced, and that this balance can be achieved through a prolonged in vitro culture. Furthermore, we show that SP cells, with confirmed molecular characteristics of MM stem cells, can be regenerated from purified NSP cell populations. We also show that the percentage of SP cells can be enhanced by the hypoxic stress, which is frequently observed within MM tumors. Finally, hypoxic stress enhanced the expression of transforming growth factor ?1 (TGF-?1) and blocking the TGF-?1 signaling pathway inhibited the NSP dedifferentiation. Taken together, these findings indicate that the balance between MM SP and NSP is regulated by environmental factors and TGF-?1 pathway is involved in hypoxia-induced increase of SP population. Understanding the mechanisms that facilitate SP maintenance will accelerate the design of novel therapeutics aimed at controlling these cells in MM. PMID:25042852

Wen, Jianguo; Tao, Wenjing; Kuiatse, Isere; Lin, Pei; Feng, Yongdong; Jones, Richard J; Orlowski, Robert Z; Zu, Youli

2015-03-01

283

Galvanic protection distance of zinc coated steels under various environmental conditions  

SciTech Connect

Galvanic action between zinc and steel is an important property which contributes to the high corrosion resistance of zinc coated steels. Quantitative knowledge of the galvanic throwing power, i.e. the area of the steel surface which is not covered with zinc but is galvanically protected by the coating in the surrounding area, is of practical importance to the effective application of zinc coated steel products. This paper reports the results of a study of the galvanic protection distance determined for the steel/zinc galvanic couple under various laboratory and field conditions.

Zhang, X.G. [Cominco Product Technology Centre, Mississauga, Ontario (Canada)

1998-12-31

284

Acoustic noise in deep ice and environmental conditions at the South Pole  

E-print Network

To study the acoustic properties of the Antarctic ice the South Pole Acoustic Test Setup (SPATS) was installed in the upper part of drill holes for the IceCube neutrino observatory. An important parameter for the design of a future acoustic neutrino telescope is the acoustic background noise in the ice and its spatial and temporal variations. We study the absolute noise level depth profile from SPATS data and discuss systematic uncertainties. The measured noise is very stable over one year of data taking, and we estimate the absolute noise level to be acoustic neutrino detection projects in good weather conditions.

Timo Karg; for the IceCube Collaboration

2008-11-07

285

Intracellular pH Recovery Rates in Bivalve Hemocytes Following Exposure to Acidic Environmental Conditions  

NASA Astrophysics Data System (ADS)

Predictions of ocean acidification effects upon carbonate shell-forming species have caused great concern for the future of shellfisheries. Nevertheless, bivalve species inhabiting an estuarine environment have evolved in these environments with fluctuating pH levels. Previous experimental studies conducted in our laboratory have demonstrated the ability of oyster hemocytes to maintain intracellular homeostasis under acidic external conditions. However, little information is known of this homeostatic mechanism in other molluscan shellfish species present in these same habitats. In the current study we propose to determine if other bivalve species of aquaculture interest also possess this intracellular regulation by applying an in vitro hemocyte pH-recovery assay, previously developed for oysters, on the northern quahog, Mercenaria mercenaria, the blue mussel, Mytilus edulis, and the softshell clam, Mya arenaria. Preliminary results from the determination of initial intracellular pH levels, the initial step in the rate recovery assay, indicated a pH range between 7.0-7.4. This range was comparable to initial values measured in oysters, and consistent with data reported in the current literature. The second step of the hemocyte pH-recovery assay involves exposing oyster hemocytes to acidic external conditions and measuring the ability of the hemocyte intracellular pH to maintain homeostasis (i.e. recovery rate). Results from the recovery rate process will be presented.

Croxton, A.; Wikfors, G. H.

2012-12-01

286

Control of environmental conditions at the lower boundary of field lysimeters  

NASA Astrophysics Data System (ADS)

Lysimeters are vessels containing disturbed or undisturbed soil, embedded completely in soil with its top even to the soil surface. At the bottom of lysimeters, the soil is cut off from the parent soil, and the lower boundary of lysimeters is usually exposed to atmospheric pressure. For this reason, soil water conditions may be different than of the surrounding soil. This may affect the soil-water conditions throughout the soil profile in comparison to the surrounding soil. To avoid this problem, lysimeters with a construction depth much more than the expected rooting depth should be used or a suction-controlled drainage system needs to be installed at the bottom of lysimeters. Not only the water flow but also the heat flow in the lysimeter is affected by the isolation of the soil and by the fact that the soil at the bottom of the lysimeter is cut off from the surrounding area. However, since now only a few studies have dealt with this issue. This is surprising because the soil thermal regime controls both growth and function of roots and shoots. Therefore, a new design for an automatic control of soil temperature at the lower boundary of large, undisturbed field lysimeters was developed. The objective of the intended talk is to present and evaluate the design and functionality of this new setup.

Schwärzel, Kai; Podlasly, Christian

2014-05-01

287

Organic-coated silver nanoparticles in biological and environmental conditions: fate, stability and toxicity.  

PubMed

This review paper presents the overview of processes involved in transformation of organic-coated silver nanoparticles (AgNPs) in biological systems and in the aquatic environment. The coating on AgNPs greatly influences the fate, stability, and toxicity of AgNPs in aqueous solutions, biological systems, and the environment. Several organic-coated AgNP systems are discussed to understand their stability and toxicity in biological media and natural water. Examples are presented to demonstrate how a transformation of organic-coated AgNPs in an aqueous solution is affected by the type of coating, pH, kind of electrolyte (mono- or divalent), ionic strength, organic ligands (inorganic and organic), organic matter (fulvic and humic acids), redox conditions (oxic and anoxic), and light. Results of cytotoxicity, genotoxicity, and ecotoxicity of coated AgNPs to food chain members (plants, bacteria, and aquatic and terrestrial organisms) are reviewed. Key factors contributing to toxicity are the size, shape, surface coating, surface charge, and conditions of silver ion release. AgNPs may directly damage the cell membranes, disrupt ATP production and DNA replication, alternate gene expressions, release toxic Ag(+) ion, and produce reactive oxygen species to oxidize biological components of the cell. A progress made on understanding the mechanism of organic-coated AgNP toxicity using different analytical techniques is presented. PMID:24406050

Sharma, Virender K; Siskova, Karolina M; Zboril, Radek; Gardea-Torresdey, Jorge L

2014-02-01

288

Individual differences in impulsive and risky choice: effects of environmental rearing conditions.  

PubMed

The present experiment investigated early-rearing environment modulation of individual differences in impulsive and risky choice. Rats were reared in an isolated condition (IC; n=12), in which they lived alone without novel stimuli, or an enriched condition (EC; n=11), in which they lived among conspecifics with novel stimuli. The impulsive choice task involved choices between smaller-sooner (SS) versus larger-later (LL) rewards. The risky choice task involved choices between certain-smaller (C-S) versus uncertain-larger (U-L) rewards. Following choice testing, incentive motivation to work for food was measured using a progressive ratio task and correlated with choice behavior. HPLC analyses were conducted to determine how monoamine concentrations within the prefrontal cortex (PFC) and nucleus accumbens (NAC) related to behavior in different tasks. IC rats were more impulsive than EC rats, but they did not differ in risky choice behavior. However, choice behavior across tasks was significantly correlated (i.e., the more impulsive rats were also riskier). There were no group differences in monoamine levels, but noradrenergic and serotonergic concentrations were significantly correlated with impulsive and risky choice. Furthermore, serotonin and norepinephrine concentrations in the NAC significantly correlated with incentive motivation and the timing of the reward delays within the choice tasks. These results suggest a role for domain general processes in impulsive and risky choice and indicate the importance of the NAC and/or PFC in timing, reward processing, and choice behavior. PMID:24769268

Kirkpatrick, Kimberly; Marshall, Andrew T; Smith, Aaron P; Koci, Juraj; Park, Yoonseong

2014-08-01

289

Vocal Function and Upper Airway Thermoregulation in Five Different Environmental Conditions  

PubMed Central

Purpose Phonation threshold pressure and perceived phonatory effort were hypothesized to increase and upper airway temperature decrease following exposure to cold and/or dry air. Greater changes were expected with mouth versus nose breathing. Method Using a within-participant repeated measures design, 15 consented participants (7 men, 8 women) completed 20-minute duration trials to allow for adequate thermal equilibration for both nose and mouth breathing in five different environments: three temperatures (°C) matched for relative humidity (%RH): cold (15°C/40% RH), thermally neutral (25°C/40% RH), and hot (35°C/40% RH); and two temperatures with variable relative humidity to match vapor pressure for the neutral environment (25°C/40% RH): cold (15°C/74% RH) and hot (35°C; 23% RH). Following each equilibration trial, measures were taken in this order: upper airway temperature (transnasal thermistor probe), phonation threshold pressure, and perceived phonatory effort. Results Data were analyzed using repeated measures analysis of variance and no significant differences were established. Conclusions The study hypotheses were not supported. Findings suggest that the upper airway is tightly regulated for temperature when challenged by a realistic range of temperature/relative humidity environments. This is the first study of its kind to include measurement of upper airway temperature in conjunction with measures of vocal function. PMID:23900031

Sandage, Mary J.; Connor, Nadine P.; Pascoe, David D.

2013-01-01

290

Evaluating Channel Head Conditions for Environmental Impact Assessment in Northwestern Sonoma County, California  

NASA Astrophysics Data System (ADS)

Erosion and sedimentation have been identified as processes significantly affecting water quality in northern California Coast Range watersheds. These watersheds, including the Gualala River watershed in northwestern Sonoma County, have been designated as having water quality impaired by sediment under provisions of the Clean Water Act Section 303(d). A study was performed to estimate potential increases in erosion rates resulting from proposed vineyard development of ridge top forestland in the Gualala River watershed. The study area has an extensive history of logging, with substantial ground disturbance from tractors. The study area is characterized by flat ridge tops with steeply incised drainages shaped by debris slides, rock slides and earth flows. Jurassic age sedimentary and meta-sedimentary rocks of the coastal and central belt Franciscan formation comprise the underlying bedrock. Channel head development and advancement has long been understood to play a key role in sediment delivery and is possibly the most sensitive to changes in the external factors such as changes in climate or land use (Dietrich and Dunne 1993). Quantifying the amount of sediment contributed by potential channel head incision and/or initiation is an objective of environmental analysis for the project. Field surveys were performed during the field seasons of 2005 and 2006 to acquire measurements of channel head locations and slope, channel dimensions and substrate associated with the proposed development sites. Analysis of this field data, including the use of ArcGIS, allowed us to examine the local relationships between variables that influence channel initiation. Variables considered include drainage area, slope, soil type, geology and vegetation. An initial analysis of a selection of area-slope data failed to produce an inverse area-slope relationship as has been found in previous studies by Montgomery and Dietrich (1988). A more complete evaluation of the entire data set is presented here.

Sherwood, M. N.; O'Connor, M.; Pennington, R.

2007-12-01

291

Optimizing environmental conditions for mass application of mechano-dwarfing stimuli to Arabidopsis  

NASA Technical Reports Server (NTRS)

Obtaining uniform mechano-dwarfing of Arabidopsis thaliana (L.) Heynh. seedlings within dense plantings is problematic. Alternative forms of mechano-stimulation were applied to seedlings in effort to obtain uniform growth reduction compared with undisturbed controls in both greenhouse and controlled growth environments. Arabidopsis grown under low photosynthetic photon flux (PPF) artificial light grew upright with limited leaf expansion, which enhanced mechano-responsiveness compared to that of rosette-growing plants under filtered sunlight or high PPF artificial light. Hypocotyls of seedlings grown at PPFs > 60 micromoles m-2 s-1 elongated less and had 6% less sensitivity to mechanical stress than seedlings grown at PPFs < 60 micromoles m-2 s-1. Fluorescent lamps alone (F) or fluorescent plus incandescent (F+I) lamps were compared for seedling responses to mechanical stress. Under F lighting, hypocotyl elongation was reduced 25% to 40% by twice-daily brush or plate treatments, and brushed seedlings exhibited more growth reduction than did plate treatments. Seedlings grown under F+I lamps exhibited similar stress-induced growth reduction compared to seedlings grown under F only, but stressed F+I seedlings lodged to a greater extent due to excessive hypocotyl elongation. Temperature-response studies using standardized F-only lighting indicated increased hypocotyl elongation but decreased leaf expansion, and decreased mechano-responsivity to brushing over the temperature range from 20 to 28 degrees C. Daylength studies indicated similar degrees of mechano-inhibition of hypocotyl elongation over the daylength range of 12, 16, 20, and 24 hours, whereas fresh weight of stressed seedling shoots declined compared to controls. A combination of environmental growth parameters that give repeatable, visual mechanical dwarfing of Arabidopsis include low-PPF fluorescent lighting from 55 to 60 micromoles m-2 s-1, ambient temperatures from 22 to 25 degrees C, and twice-daily brush treatments.

Montgomery, Jill A.; Bressan, Ray A.; Mitchell, Cary A.

2004-01-01

292

Environmental conditions and biotic interactions influence ecosystem structure and function in a drying stream  

USGS Publications Warehouse

Benthic consumers influence stream ecosystem structure and function, but these interactions depend on environmental context. We experimentally quantified the effects of central stoneroller minnows (Campostoma anomalum (Rafinesque) and Meek's crayfish (Orconectes meeki meeki (Faxon)) on benthic communities using electric exclusion quadrats in Little Mulberry Creek before (June) and during (August) seasonal stream drying. Unglazed ceramic tiles were deployed in June and August to measure periphyton and invertebrate abundance, and leafpack decomposition and primary production were also measured in August. Relationships between stoneroller and crayfish density and the size of consumer effects were evaluated with multiple linear regression models. Average chlorophyll a abundance was greater on exposed than exclusion tiles in August, but not in June. Sediment dry mass, periphyton ash-free dry mass (AFDM), and chironomid densities on tiles did not differ among treatments in either period. Leaf packs decayed faster in exposed than exclusion treatments (kexposed = 0.038 ?? 0.013, kexclusion = 0.007 ?? 0.002), but consumer effects were stronger in some pools than others. Leafpack invertebrate biomass and abundance and tile primary productivity did not differ among treatments. Consumer effects on chlorophyll a were related to crayfish and stoneroller density, and effects on chironomid density were related to stoneroller density. These results contrast with a previous exclusion experiment in Little Mulberry Creek that demonstrated strong consumer effects. The influence of stream drying on consumer effects appears to have been reduced by strong spates, underscoring the importance of conducting multi-year studies to determine the magnitude of variability in ecological interactions. ?? US Government: USGS 2010.

Ludlam, J.P.; Magoulick, D.D.

2010-01-01

293

Seasonal changes in condition and biochemical composition of the scallop Pecten maximus L. from suspended culture in the Ria de Arousa (Galicia, N.W. Spain) in relation to environmental conditions  

Microsoft Academic Search

Seasonal changes in condition and biochemical composition of striated adductor muscle, digestive gland and female gonad of raft cultured Pecten maximus L. in the Ria de Arousa (Galicia, N.W. Spain) were studied over 16 months in relation to environmental conditions and reproductive events. Pecten maximus in the Ria de Arousa showed a clear cycle of energy storage and utilisation. Between

A. J. Pazos; G. Román; C. P. Acosta; M. Abad; J. L. Sánchez

1997-01-01

294

Formation of Martian Gullies by the Action of Liquid Water Flowing Under Current Martian Environmental Conditions  

NASA Technical Reports Server (NTRS)

Images from the Mars Orbiter Camera (MOC) on the Mars Global Surveyor (MGS) spacecraft show geologically young small-scale features resembling terrestrial water-carved gullies. An improved understanding of these features has the potential to reveal important information about the hydrological system on Mars, which is of general interest to the planetary science community as well as the field of astrobiology and the search for life on Mars. The young geologic age of these gullies is often thought to be a paradox because liquid water is unstable at the Martian surface. Current temperatures and pressures are generally below the triple point of water (273 K, 6.1 mbar) so that liquid water will spontaneously boil and/or freeze. We therefore examine the flow of water on Mars to determine what conditions are consistent with the observed features of the gullies.

Heldmann, J. L.; Toon, O. B.; Pollard, W. H.; Mellon, M. T.; Pitlick, J.; McKay, C. P.; Andersen, D. T.

2005-01-01

295

Fretting wear of iron, nickel, and titanium under varied environmental conditions  

NASA Technical Reports Server (NTRS)

Fretting wear experiments were conducted on high purity iron, nickel and titanium in air under conditions of varied humidity and temperature, and in nitrogen. For iron and titanium, maximum fretting occurred at 10 and 30 percent relative humidity respectively. Nickel showed a minimum in fretting wear at about 10 percent relative humidity. With increasing temperature, all three metals initially showed reduced fretting wear, with increasing wear observed as temperatures increased beyond 200-300 C. For titanium, dramatically reduced fretting wear was observed at temperatures above 500 C, relatable to a change in oxidation kinetics. All three metals showed much less fretting wear in N2 with the presence of moisture in N2 having a proportionally stronger effect than in air.

Bill, R. C.

1978-01-01

296

Fretting wear of iron, nickel, and titanium under varied environmental conditions  

NASA Technical Reports Server (NTRS)

Fretting wear experiments were conducted on high-purity iron, nickel and titanium in air under conditions of varied humidity and temperature, and in nitrogen. For iron and titanium, maximum fretting occurred at 10 and 30 percent relative humidity respectively. Nickel showed a minimum in fretting wear at about 10% relative humidity. With increasing temperature, all three metals initially showed reduced fretting wear, with increasing wear observed as temperatures increased beyond 200-300 C. For titanium, dramatically reduced fretting wear was observed at temperatures above 500 C, relatable to a change in oxidation kinetics. All three metals showed much less fretting wear in N2 with the presence of moisture in N2 having a proportionally stronger effect than in air.

Bill, R. C.

1979-01-01

297

[Developmental periods and adaptation of parthenites of Eurytrema pancreaticum (Dicrocoeliidae, Trematoda) to environmental conditions].  

PubMed

Data are given on the developmental periods of parthenites of E. pancreaticum (Janson, 1889) from the Far East of the USSR. The growth and formation of parthenites were found to take place from May to October and to coincide with the active period of the intermediate host's life cycle. With the decrease of autumn temperatures to 8 degrees the growth of parthenites slows down and ceases completely in October. The pause in the development of parthenites from October to April causes longer developmental periods of parthenites as compared to those in the regions of tropical and subtropical climate. Under laboratory conditions at a temperature of 8 to 22 degrees the development of parthenites proceeds without any intervals within 6.5 months. PMID:1018937

Dvoriadkin, V A

1976-01-01

298

Effectiveness of low concentration electrolyzed water to inactivate foodborne pathogens under different environmental conditions.  

PubMed

Strong acid electrolyzed water (SAEW) has a very limited application due to its low pH value (<2.7) and corrosive characteristics. Thus, we developed new low concentration electrolyzed water (LcEW). The efficacy of LcEW under various treatment conditions for the inactivation of different foodborne pathogens in pure culture was evaluated and compared with SAEW. The efficiency of LcEW and SAEW for the inactivation of predominant foodborne pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus and Salmonella Typhimurium) with different dipping times (1, 3, 5, 7 and 10 min), pH values (2.5, 4.0, 5.0, 6.0 and 9.0) and temperatures (4, 15, 23, 35 and 50 degrees C) were determined. Reductions of bacterial populations of 1.7 to 6.6 log(10) CFU/mL in various treated conditions in cell suspensions were observed after treatment with LcEW and SAEW, compared to the untreated control. Dip washing (1 min at 35 degrees C) of lettuce leaves in both electrolyzed water resulted in 2.5 to 4.0 log(10) CFU/g compared to the unwashed control. Strong inactivation effects were observed in LcEW, and no significant difference (p>0.05) was observed between LcEW and SAEW. The effective form of chlorine compounds in LcEW was almost exclusively hypochlorous acid (HOCl), which has strong antimicrobial activity and leaves no residuals due to the low concentration of residual chlorine. Thus, LcEW could be widely applied as a new sanitizer in the food industry. PMID:20385418

Rahman, S M E; Ding, Tian; Oh, Deog-Hwan

2010-05-15

299

Phytoplankton summer bloom dynamics in the Bahía Blanca Estuary in relation to changing environmental conditions  

NASA Astrophysics Data System (ADS)

We examined austral summer phytoplankton data (December-March) that cover the years 1978-2008 and compared with physico-chemical and meteorological variations in the Bahía Blanca Estuary, Argentina. During the years 1978-1982, 1992-1993 and 2006-2008, counts of phytoplankton abundance showed an increase in recent summers; from a mean value of 12×103 cells L-1 in 1978 to 2239×103 cells L-1 in 2008, while the chlorophyll concentration remained relatively constant (8.5±2.5 ?g L-1, CV=27%) over the continuous time series (1978-2008). The rise in the ratio 'cell abundance: chlorophyll concentration' was linked to modifications in species composition, from dominance of phytoflagellates (10-20 ?m) and relatively large diatoms (e.g., Cyclotella striata 25-38 ?m, Paralia sulcata 15-70 ?m, Cerataulina pelagica 18-30 ?m, Thalassiosra hendeyi 27-52 ?m) towards the dominance of the small (5-15 ?m) centric diatom Thalassiosira minima, which reached >80% of the total phytoplankton abundance in summers 2006-2008. The Bahía Blanca Estuary has undergone climate modifications and increasing anthropogenic disturbances during the last three decades. In the early 1990s, regional climatic conditions revealed a significant shift. Additionally, dredging activities were initiated to allow the traffic of large ships, rising the levels of suspended sediments, and the invasive copepod Eurytemora americana was introduced via ballast waters into the estuary and has displaced the dominance of the native copepod Acartia tonsa towards summer periods. The examination of physico-chemical conditions of the estuary showed a trend to increase in the minima of water temperature and higher water turbidity, dissolved phosphate, nitrite and nitrate concentrations in the pelagic environment in recent summers. We discuss the potential effects of these changes and trophic interactions on the structure and composition of the phytoplankton summer blooms in this temperate and eutrophic estuary in the Southwestern Atlantic.

Guinder, Valeria A.; Popovich, Cecilia A.; Molinero, Juan Carlos; Marcovecchio, Jorge

2013-01-01

300

Cultural methods and environmental conditions affecting gray mold and its management in lisianthus.  

PubMed

Gray mold, caused by Botrytis cinerea, severely affects the base of the stems of lisianthus (Eustoma grandiflorum) plants as well as the cut stems left after flowers are harvested. This study examined infection of lisianthus plants by B. cinerea under laboratory and commercial greenhouse production conditions typical for Israel and evaluated cultural methods for manipulating disease development in commercial greenhouses. Although the lower nodes of lisianthus stems are typically infected, in this study, the inherent susceptibility of these nodes was less than that of nodes midway up the stem. Greater light intensity (4,860 lux) was associated with significantly more severe stem wounds than lower light intensities of 140 to 1,020 lux. Lower light intensity (140 lux) was associated with significantly more severe leaf infection. The development of gray mold along leaves toward the stem was slower at 26 degrees C than at 18 to 20 degrees C and was fastest at relative humidity (RH) levels close to saturation (>99%). B. cinerea infection developed in all stem wounds exposed to 65 to 99% RH and at temperatures of 12 to 29 degrees C. Infection severity in stem wounds (measured as lesion length) on whole plants was significantly less at 26 degrees C than at 18 or 22 degrees C, and was significantly higher at 99% RH compared with 70 to 85 and 85 to 95% RH. Severity of gray mold was the greatest at 15 to 22 degrees C and 85 to 99% RH. Under commercial greenhouse conditions, supplemental calcium (Ca(NO3)2) applied in fertigation or as a spray led to moderate yet significant reduction in disease severity. In addition, polyethylene soil cover and the use of buried drip irrigation instead of surface drip irrigation suppressed gray mold significantly on cut stems following harvest. Covering the soil with polyethylene also suppressed gray mold significantly as compared with the common practice of growing lisianthus in bare soil. PMID:19351252

Shpialter, Lena; David, Dalia Rav; Dori, Irit; Yermiahu, Uri; Pivonia, Shimon; Levite, Rahel; Elad, Yigal

2009-05-01

301

Functional ecology of saltglands in shorebirds: Flexible responses to variable environmental conditions  

USGS Publications Warehouse

Birds of marine environments have specialized glands to excrete salt, the saltglands. Located on the skull between the eyes, the size of these organs is expected to reflect their demand, which will vary with water turnover rates as a function of environmental (heat load, salinity of prey and drinking water) and organismal (energy demand, physiological state) factors. On the basis of inter- and intraspecific comparisons of saltgland mass (m sg) in 29 species of shorebird (suborder Charadrii) from saline, fresh and mixed water habitats, we assessed the relative roles of organism and environment in determining measured m sg species. The allometric exponent, scaling dry m sg to shorebird total body mass (m b), was significantly higher for coastal marine species (0??88, N=19) than for nonmarine species (0??43, N=14). Within the marine species, those ingesting bivalves intact had significantly higher m sg than species eating soft-bodied invertebrates, indicating that seawater contained within the shells added to the salt load. In red knots (Calidris canutus), dry m sg varied with monthly averaged ambient temperature in a U-shaped way, with the lowest mass at 12??5??C. This probably reflects increased energy demand for thermoregulation at low temperatures and elevated respiratory water loss at high temperatures. In fuelling bar-tailed godwits (Limosa lapponica), dry m sg was positively correlated with intestine mass, an indicator of relative food intake rates. These findings suggest once more that saltgland masses vary within species (and presumably individuals) in relation to salt load, that is a function of energy turnover (thermoregulation and fuelling) and evaporative water needs. Our results support the notion that m sg is strongly influenced by habitat salinity, and also by factors influencing salt load and demand for osmotically free water including ambient temperature, prey type and energy intake rates. Saltglands are evidently highly flexible organs. The small size of saltglands when demands are low suggests that any time costs of adjustment are lower than the costs of maintaining a larger size in this small but essential piece of metabolic machinery. ?? 2011 The Authors. Functional Ecology ?? 2011 British Ecological Society.

Gutierrez, J.S.; Dietz, M.W.; Masero, J.A.; Gill, R.E.; Dekinga, A.; Battley, Phil F.; Sanchez-Guzman, J. M.; Piersma, T.

2012-01-01

302

Investigation of Techniques to Improve Continuous Air Monitors Under Conditions of High Dust Loading in Environmental Settings  

SciTech Connect

A number of DOE facilities, such as the Los Alamos National Laboratory (LANL) and the Waste Isolation Pilot Plant (WIPP), use alpha-particle environmental continuous air monitors (ECAMs) to monitor air for unwanted releases of radioactive aerosols containing such materials as plutonium and uranium. High sensitivity, ease of operation, and lack of false alarms are all important for ECAMs. The object of the project was to conduct investigations to improve operation of ECAMs, particularly under conditions where a lot of nonradioactive dust may be deposited on the filters (conditions of high dust loading). The presence of such dust may increase the frequency with which filters must be changed and can lead to an increased incidence of false alarms due to deteriorated energy resolution and response specificity to the radionuclides of interest. A major finding of the investigation, not previously documented, was that under many conditions thick layers of underlying nonradioactive dust do not decrease energy resolution and specificity for target radionuclides if the radioactive aerosol arrives as a sudden thin burst deposit, as commonly occurs in the early-warning alarm mode. As a result, operators of ECAMs may not need to change filters as often as previously thought and have data upon which to base more reliable operating procedures.

Suilou Huang; Stephen D. Schery; John C. Rodgers

2002-07-23

303

Delimitation of Areas of Environmental Conflicts on the Background of Geological Conditions, Exemplified by Stary S?cz Commune  

NASA Astrophysics Data System (ADS)

Delimitation and characterization of areas of conflict are essential to assess suitability of land for different activities carried out in the field of rational land use. In the paper, delimitation of the conflict areas and conflicts categorization in terms of possibility of their overcoming, the scale of the range and the period of their occurrence exemplified by urban - rural commune Stary S?cz have been presented. The software ArcGIS 10.1, the method of maps superimposing and analysis of interactions between different geoenvironmental factors have been applied to obtain the goal of the investigation. Specific geological structure together with morphological and climatic conditions in Stary S?cz commune create ideal conditions for occurrence of con-flict areas on the background of the geological conditions. Accurate and early recognition of these conflicts - existing and potential ones, is a prerequisite for the environmental risk prevention and elimination of its effects through the proper preparation of planning documents and development plans and programs.

Ga?a?, Slávka

2014-12-01

304

Environmental Change: Precipitation and N, P, K, mg Fertilization Influences on Crop Yield Under Temperate Climate Conditions  

NASA Astrophysics Data System (ADS)

Summary: Agroecological quality has a well estabished dependence on climate-rainfall changes because the water problems are pressing. Therefore, there is, growing concern about the potentially wide ranging risks that climate change would have on these key industries as the nature and extent of anticipated changes have become more evident. It also includes changes in land use and in plant production and their management. These changes are unprecedented in terms of both their rate and their spatial extent. Changes in land use (agrotechnics, soil, cultivation, fertility, quality, protection etc.) and in plant production (plant, nutrition, rotation, protection etc.) are currently the main manifestations. As an interdisciplinary problem it is necessary to study such a complex matter in terms of agricultural production. Generally, among natural catastrophes, droughts and floods cause the greatest problems in field crop production. The droughts and the floods that were experienced in Hungary in the early 1980s have drawn renewed attention to the analyses of these problems. New research on climate change-soil-plant systems are focused on yield and yield quality. This paper reports of the climate changes (rainfall); soil (acidic sandy brown forest) properties, mineral N, P, K, Mg fertilisation level and plant interactions on rye (Secale cereale L.), on potato (Solanum tuberosum L.) and on winter wheat (Triticum aestivum L.) yields in a long term field experiment set up at Nyírlugos in north-eastern Hungary under temperate climate conditions in 1962. Results are summarised from 1962 to 1990. Main conclusions were as follows: 1. Rye: a, Experimental years were characterised by frequent extremes of precipitation variabilities and changes. b, By an average year, at a satisfactory fertilisation level (N: 90 kg ha-1 and NP, NK, NPK, NPKMg combinations) the maximum yield reached 3.8 t ha-1. But yield was decreased by 17% and by 52% due to drought and excess rainfall, respectively. Negative effects (drought, excess rainfall) were diminished by 20-25% with Mg treatments. c, Correlation between rye yields and precipitation during vegetation seasons showed that optimum yield (4.0 t ha-1) develops in the 430-470 mm range. 2. Potato: a, Trial years were estimated by recurrent extremes of climate. b, In vegetation seasons poor in rainfall yield safety in potato cannot be secured by fertilisation (N, NP, NK, NPK, NPKMg) alone. Under this weather condition yield was decreased by 35%. c, Optimum yields range between 17-21 t ha-1 at 280-350 mm. 3. Winter wheat: a, Climate was manifested mainly by precipitation using average, drought, dry and rainy levels. b, Yields from drought year effects with N, NP and NK combinations were diminished to 48% and with NPK and NPKMg treatments fell to 51%. c, Optimum yields (3.5-4.0 t ha-1) were developed at 450-500 mm. This paper summarises quantified results of rye, potato and winter wheat research with regarding to interaction effects and relationships between climate (rainfall)-mineral nutrition-crop production changes in Hungary during a long term field experiment to agricultural sustainability. Key words: ecology, rainfall, crop, fertilization, yield Introduction: "Climate Change" are recognized as a serious environmental issues [1]. Presently the build up of greenhouse gases in the atmosphere and the inertia in trends in emissions means that we can expect significant changes for at least the next few decades and probably for the whole 21th century too [2]. It would badly need to understand what might be involved in adapting to the new climates. A decade ago, researchers asked the „what if" question. For example, what will be the impact if climate changes. Now, we must increasingly address the following question: how do we respond effectivelly to prevent damaging impacts and take advantage of new climatic opportunities [3]. This question requires detailed in information regarding expected impacts and effectíve adaptive measures. Information on adaptation is required for governments, la

László Phd, Dd. M.

2009-04-01

305

Characteristics of a Microcystin-Degrading Bacterium under Alkaline Environmental Conditions  

PubMed Central

The pH of the water associated with toxic blooms of cyanobacteria is typically in the alkaline range; however, previously only microcystin-degrading bacteria growing in neutral pH conditions have been isolated. Therefore, we sought to isolate and characterize an alkali-tolerant microcystin-degrading bacterium from a water bloom using microcystin-LR. Analysis of the 16S rRNA gene sequence revealed that the isolated bacterium belonged to the genus Sphingopyxis, and the strain was named C-1. Sphingopyxis sp. C-1 can grow; at pH 11.0; however, the optimum pH for growth was pH 7.0. The microcystin degradation activity of the bacterium was the greatest between pH 6.52 and pH 8.45 but was also detected at pH 10.0. The mlrA homolog encoding the microcystin-degrading enzyme in the C-1 strain was conserved. We concluded that alkali-tolerant microcystin-degrading bacterium played a key role in triggering the rapid degradation of microcystin, leading to the disappearance of toxic water blooms in aquatic environments. PMID:20224628

Okano, Kunihiro; Shimizu, Kazuya; Kawauchi, Yukio; Maseda, Hideaki; Utsumi, Motoo; Zhang, Zhenya; Neilan, Brett A.; Sugiura, Norio

2009-01-01

306

Fish assemblage structure and relations with environmental conditions in a Rocky Mountain watershed  

USGS Publications Warehouse

Fish and habitat were sampled from 110 reaches in the Salt River basin (Idaho and Wyoming) during 1996 and 1997 to assess patterns in fish assemblage structure across a Rocky Mountain watershed. We identified four distinct fish assemblages using cluster analysis: (1) allopatric cutthroat trout (Oncorhynchus clarki (Richardson, 1836)); (2) cutthroat trout - brook trout (Salvelinus fontinalis (Mitchell, 1814)) - Paiute sculpin (Cottus beldingi Eigenmann and Eigenmann, 1891); (3) cutthroat trout - brown trout (Salmo trutta L., 1758) - mottled sculpin (Cottus bairdi Girard, 1850); and (4) Cyprinidae-Catostomidae. The distribution of fish assemblages was explained by thermal characteristics, stream geomorphology, and local habitat features. Reaches with allopatric cutthroat trout and the cutthroat trout - brook trout - Paiute sculpin assemblage were located in high-elevation, high-gradient streams. The other two fish assemblages were generally located in low-elevation streams. Associations between habitat gradients, locations of reaches in the watershed, and occurrence of species were further examined using canonical correspondence analysis. The results suggest that stream geomorphology, thermal conditions, and local habitat characteristics influence fish assemblage structure across a Rocky Mountain watershed, and they provide information on the ecology of individual species that can guide conservation activities. ?? 2004 NRC Canada.

Quist, M.C.; Hubert, W.A.; Isaak, D.J.

2004-01-01

307

The impact of exceptionally warm summer inflow events on the environmental conditions in the Bornholm Basin  

NASA Astrophysics Data System (ADS)

In late summer 2002 and 2003, exceptionally warm inflow events of saline water were observed in the Baltic. These warm saline waters were embedded in the halocline of the Bornholm Basin and caused a strong anomaly of the seasonal temperature cycle. The temperature in October 2002 was the highest ever observed in the halocline of the Bornholm Basin. Although the oxygen content of the inflowing water was only about 1.5 ml l - 1 at the Darss Sill, it caused a moderate ventilation of the halocline in the Bornholm Basin. On the way through the Arkona Basin, the entrainment of ambient water increased the oxygen content of the inflowing saline water masses. Warm summer inflows were rare events in the last 50 years, but their frequency has increased since 1990. This is likely caused by climate change. The analysis of a 50-year time series of hydrographic parameters reveals significant changes of the thermal regime around the year 1988. The winter surface and intermediate water temperatures of the Bornholm Basin increased by about 1 °C. Also, the duration of warm water in the surface layer was prolonged after 1988. A high correlation between the minimum intermediate winter water temperatures and the NAO winter index was found. Since temperature is a key parameter for many biological processes various responses of the ecosystem to the change in hydrographic conditions could be expected. Possible biological implications of the warm inflow events for the ecosystem are discussed.

Mohrholz, Volker; Dutz, Jörg; Kraus, Gerd

2006-05-01

308

Computer prediction of human thermoregulatory and temperature responses to a wide range of environmental conditions.  

PubMed

A mathematical model for predicting human thermal and regulatory responses in cold, cool, neutral, warm, and hot environments has been developed and validated. The multi-segmental passive system, which models the dynamic heat transport within the body and the heat exchange between body parts and the environment, is discussed elsewhere. This paper is concerned with the development of the active system, which simulates the regulatory responses of shivering, sweating, and peripheral vasomotion of unacclimatised subjects. Following a comprehensive literature review, 26 independent experiments were selected that were designed to provoke each of these responses in different circumstances. Regression analysis revealed that skin and head core temperature affect regulatory responses in a nonlinear fashion. A further signal, i.e. the rate of change of the mean skin temperature weighted by the skin temperature error signal, was identified as governing the dynamics of thermoregulatory processes in the cold. Verification and validation work was carried out using experimental data obtained from 90 exposures covering a range of steady and transient ambient temperatures between 5 degrees C and 50 degrees C and exercise intensities between 46 W/m2 and 600 W/m2. Good general agreement with measured data was obtained for regulatory responses, internal temperatures, and the mean and local skin temperatures of unacclimatised humans for the whole spectrum of climatic conditions and for different activity levels. PMID:11594634

Fiala, D; Lomas, K J; Stohrer, M

2001-09-01

309

Computer prediction of human thermoregulatory and temperature responses to a wide range of environmental conditions  

NASA Astrophysics Data System (ADS)

A mathematical model for predicting human thermal and regulatory responses in cold, cool, neutral, warm, and hot environments has been developed and validated. The multi-segmental passive system, which models the dynamic heat transport within the body and the heat exchange between body parts and the environment, is discussed elsewhere. This paper is concerned with the development of the active system, which simulates the regulatory responses of shivering, sweating, and peripheral vasomotion of unacclimatised subjects. Following a comprehensive literature review, 26 independent experiments were selected that were designed to provoke each of these responses in different circumstances. Regression analysis revealed that skin and head core temperature affect regulatory responses in a non-linear fashion. A further signal, i.e. the rate of change of the mean skin temperature weighted by the skin temperature error signal, was identified as governing the dynamics of thermoregulatory processes in the cold. Verification and validation work was carried out using experimental data obtained from 90 exposures covering a range of steady and transient ambient temperatures between 5°C and 50°C and exercise intensities between 46 W/m2 and 600 W/m2. Good general agreement with measured data was obtained for regulatory responses, internal temperatures, and the mean and local skin temperatures of unacclimatised humans for the whole spectrum of climatic conditions and for different activity levels.

Fiala, D.; Lomas, K. J.; Stohrer, M.

310

Study on corrosion behaviors of sintered Nd-Fe-B magnets in different environmental conditions  

SciTech Connect

Nd-Fe-B magnets have outstanding magnetic properties, but their corrosion resistance is poor because the rare-earth-rich phases in them are easily oxidized. In this article, we report an investigation of the corrosion behaviors of sintered Nd-Fe-B magnets with varied compositions in different corrosion conditions. The weight losses of the magnets after corrosion testing were measured after brushing off the corrosion products. The magnetic flux losses of the magnets were measured using a fluxmeter. A scanning electron microscope equipped with an energy dispersive x-ray analysis system was employed to observe the corrosion morphology. It was found that the humid-heat resistance of the magnets was obviously improved by partially substituting Dy for Nd and adding minor Co. The corrosion products and morphologies of Nd-Fe-B magnets for the autoclave test were different from those for the constant humid-heat test. The corrosion rates of the magnets for the former were much slower than for the latter; this is probably because the high-pressure steam led to an oxygen-deficient atmosphere, and the liquid film on the surface of the magnet specimens hindered the diffusion of oxygen into the bulk for the autoclave test.

Li, J. J.; Li, A. H.; Zhu, M. G.; Pan, W.; Li, W.

2011-04-01

311

Characterization of environmental conditions for microbial dolomite precipitation and early diagenesis: Brejo do Espinho, Rio de Janeiro, Brazil  

NASA Astrophysics Data System (ADS)

For more than 150 years, the mineral dolomite constituting sedimentary dolomite rocks has been considered to be mainly a replacement product of the calcium carbonate components comprising the original limestone, a process known as secondary replacement dolomitization. This interpretation has been based principally on petrographic observations, as well as the analysis of the sequence of mineralogic events that have occurred during early and late diagenesis with burial. Although numerous dolomite formations in the geologic record are composed of fine-grained crystals of micritic dolomite, an alternative process, primary precipitation, is often excluded because of the absence of visible or geochemical indicators that can be used to identify this process. Defining criteria to distinguish between these two dolomite-forming processes has been hindered by the rarity of modern dolomite forming milieus where the environmental variables promoting the growth of the mineral can be studied. Here, we present a study of Brejo do Espinho, a small coastal lagoon in Rio de Janeiro State, Brazil, located in a special climate regime where a well-defined seasonal cycle of wet and dry conditions occurs. Modern dolomite precipitation from the lagoonal waters under low-temperature hypersaline conditions is deemed to be associated with the activity of microbial organisms living in this restricted environment. To advance our understanding of the biomineralization process, we characterized the variations of the physico-chemical conditions in this environment and integrated these new data with the inventory of hydrologic isotopic studies from this unique coastal region. It was possible to distinguish the environmental conditions under which two remarkable dolomite facies, fine-grained mud and semi-lithified crust, formed. The crust displays the more positive ?18O value, which is interpreted as reflecting a period when the lagoon is nearly or completely desiccated and the oxygen-18 content of the saline water is highly enriched. The mineralogical studies of the crust show that the dolomite peloids are surrounded by dolomitic microspar cement, which is characteristic of exposure episodes. These observations support the hypothesis that the crust formed under more extreme arid conditions than the mud, which precipitates in equilibrium with less oxygen-18 enriched lagoon water. However, both mud and crust formed at relatively warm Earth surface temperatures, greater than 30oC, based on clumped isotope analysis. Because similar dolomite-forming environments may have been more widespread in ancient marine or lacustrine ecosystems, the well-controlled data set acquired during this study has important implications for calibrating the environmental conditions promoting primary dolomite precipitation and early diagenesis. Calibration of the annual water cycle in modern dolomite-forming environments provides important data to develop geochemical and macro/microscopic criteria to discern the origin of ancient dolomite and possibly distinguish between the two competing mechanisms for dolomite formation.

McKenzie, J. A.; Bahniuk, A. M.; Anjos, S. C.; Perri, E.; Vasconcelos, C.

2013-12-01

312

Impact of environmental conditions on the suitability of microconstituents as markers for determining nutrient loading from reclaimed water.  

PubMed

Nitrogen and phosphorous loading into waterways from designated beneficial uses of reclaimed water is a growing concern in many parts of the United States. Numerous studies have documented that organic microconstituents present in the reclaimed water can be utilized as indicators of its influence on surface water bodies. However, little to no information is available on the environmental attenuation of these microconstituents relative to the nutrients, which is a critical component in determining the effectiveness or limitations of those markers as a tool for elucidating their origins. In this study, the stability of selected markers (sucralose, carbamazepine, gadolinium anomaly, iohexol, and atenolol) was evaluated through bench-scale studies designed to simulate environmental conditions associated with biodegradation, adsorption, and photolysis. The primary pathway for nitrogen reduction was biodegradation (greater than 99%) while the highest phosphorous removal was due to adsorption (30-80%). Soils with low organic content were selected for this study. Sucralose was the most recalcitrant microconstituent in the environment with less than 15% removal by adsorption, biodegradation, or photolysis. Iohexol was too susceptible to photolysis (90% removal), and atenolol was susceptible to biodegradation (60-80% removal). Gd anomaly was fairly stable (less than 30% removal) in the environment. Carbamazepine was another efficacious marker for wastewater, but was susceptible (50% removal) to photolysis. Of the selected microconstituents, only atenolol showed any similarity with the attenuation observed for nitrate and none of the microconstituents showed any similarity with the attenuation observed for phosphorus. PMID:24054084

Badruzzaman, Mohammad; Oppenheimer, Joan A; Jacangelo, Joseph G

2013-10-15

313

Improvement of Text Dependent Speaker Identification System Using Neuro-Genetic Hybrid Algorithm in Office Environmental Conditions  

E-print Network

In this paper, an improved strategy for automated text dependent speaker identification system has been proposed in noisy environment. The identification process incorporates the Neuro- Genetic hybrid algorithm with cepstral based features. To remove the background noise from the source utterance, wiener filter has been used. Different speech pre-processing techniques such as start-end point detection algorithm, pre-emphasis filtering, frame blocking and windowing have been used to process the speech utterances. RCC, MFCC, MFCC, MFCC, LPC and LPCC have been used to extract the features. After feature extraction of the speech, Neuro-Genetic hybrid algorithm has been used in the learning and identification purposes. Features are extracted by using different techniques to optimize the performance of the identification. According to the VALID speech database, the highest speaker identification rate of 100.000 percent for studio environment and 82.33 percent for office environmental conditions have been achieved i...

Islam, Md Rabiul

2009-01-01

314

Impact and correlation of environmental conditions on pollen counts in karachi, pakistan.  

PubMed

A quantitative and qualitative survey of airborne pollen was performed in the city of Karachi, and the pollen counts were correlated with different climatic conditions. The aim of the study was to determine the possible effect of meteorological factors on airborne pollen distribution in the atmosphere of Karachi city. Pollen sampling was carried out by using Burkard spore Trap for the period of August 2009 to July 2010, and a total of 2,922 pollen grains/m3 were recorded. In this survey, 22 pollen types were recognized. The highest pollen count was contributed by Poaceae pollen type (1,242 pollen grains/m3) followed by Amaranthaceae/Chenopodiaceae (948 pollen grains/m3), Cyperus rotundus (195 pollen grains/m3) and Prosopis juliflora (169 pollen grains/m3). Peak pollen season was in August showing a total of 709 pollen grains/m3 and lowest pollen count was observed in January-2010. Pearson's chi-square test was performed for the possible correlation of pollen counts and climatic factors. The test revealed significant positive correlation of wind speed with pollen types of Amaranthaceae/Chenopodiaceae; Brassica campestris; Asteraceae; and Thuja orientalis. While the correlation of "average temperature" showed significant positive value with Asteraceae and Tamarix indica pollen types. Negative correlation was observed between humidity/ precipitation and pollen types of Brassica campestris; Daucus carota; Ephedra sp.; and Tamarix indica. In the light of above updated data one could identify various aeroallergens present in the air of Karachi city. PMID:25530143

Perveen, Anjum; Khan, Muneeba; Zeb, Shaista; Imam, Asif Ali

2015-02-01

315

Impact of Environmental Conditions on the Form and Function of Candida albicans Biofilms  

PubMed Central

Candida albicans, like other pathogens, can form complex biofilms on a variety of substrates. However, as the number of studies of gene regulation, architecture, and pathogenic traits of C. albicans biofilms has increased, so have differences in results. This suggests that depending upon the conditions employed, biofilms may vary widely, thus hampering attempts at a uniform description. Gene expression studies suggest that this may be the case. To explore this hypothesis further, we compared the architectures and traits of biofilms formed in RPMI 1640 and Spider media at 37°C in air. Biofilms formed by a/? cells in the two media differed to various degrees in cellular architecture, matrix deposition, penetrability by leukocytes, fluconazole susceptibility, and the facilitation of mating. Similar comparisons of a/a cells in the two media, however, were made difficult given that in air, although a/a cells form traditional biofilms in RPMI medium, they form polylayers composed primarily of yeast cells in Spider medium. These polylayers lack an upper hyphal/matrix region, are readily penetrated by leukocytes, are highly fluconazole susceptible, and do not facilitate mating. If, however, air is replaced with 20% CO2, a/a cells make a biofilm in Spider medium similar architecturally to that of a/? cells, which facilitates mating. A second, more cursory comparison is made between the disparate cellular architectures of a/a biofilms formed in air in RPMI and Lee's media. The results demonstrate that C. albicans forms very different types of biofilms depending upon the composition of the medium, level of CO2 in the atmosphere, and configuration of the MTL locus. PMID:23954841

Daniels, Karla J.; Park, Yang-Nim; Srikantha, Thyagarajan; Pujol, Claude

2013-01-01

316

Efficiency of different sanitation methods on Listeria monocytogenes biofilms formed under various environmental conditions.  

PubMed

The resistance of Listeria monocytogenes biofilms formed under food processing conditions, against various sanitizing agents and disinfection procedures was evaluated in the present study. The first sanitation procedure included biofilm formation on stainless steel coupons (SS) placed in tryptic soy broth supplemented with 0.6% yeast extract (TSBYE) of various concentrations of NaCl (0.5, 7.5 and 9.5%) at different temperatures (5 and 20 °C). The biofilms formed were exposed to warm (60 °C) water for 20 min, or to peroxyacetic acid (2% PAA) for 1, 2, 3 and 6 min. Treatment with warm water caused no significant (P ? 0.05) reductions in the attached populations. Conversely, surviving bacteria on SS coupons decreased as the exposure time to 2% PAA increased and could not be detected by culture after 6 min of exposure. Biofilms formed at 20°C were more resistant to PAA than biofilms formed at 5 °C. Salt concentration in the growth medium had no marked impact on the resistance to PAA. The second sanitation procedure included biofilm formation of nonadapted (NA) and acid-adapted (AA) cells in TSBYE of pH 5.0 and 7.0 (i.e., NA-5.0, NA-7.0 and AA-5.0, AA-7.0) at 4 °C. Coupons bearing attached cells of L. monocytogenes were periodically exposed to chlorine (0.465% Cl(-)), quaternary ammonium compound (1% QAC) and 2% PAA. The resistance of attached cells to QAC, PAA and Cl(-) followed the order: AA-5.0>NA-7.0 ? AA-7.0>NA-5.0. The most effective sanitizer was QAC followed by PAA and Cl(-). The results can lead to the development of efficient sanitation strategies in order to eliminate L. monocytogenes from the processing environment. Furthermore, such results may explain the presence of L. monocytogenes after sanitation as a result of cell attachment history. PMID:21093085

Belessi, Charalambia-Eirini A; Gounadaki, Antonia S; Psomas, Antonios N; Skandamis, Panagiotis N

2011-03-01

317

Adaptation strategies to seasonal changes in environmental conditions of a domesticated horse breed, the Shetland pony (Equus ferus caballus).  

PubMed

Recent results suggest that the wild ancestor of the horse, the Przewalski horse, exhibits signs of a hypometabolism. However, there are speculations that domestic animals lost the ability to reduce energy expenditure during food shortage and adverse environmental conditions. Therefore, we investigated physiological and behavioural strategies employed by a robust domesticated horse breed, the Shetland pony, over the course of a year under temperate conditions by measuring ambient temperature (T(a)), subcutaneous temperature (T(s)), locomotor activity (LA), lying time, resting heart rate, body mass and body condition score. Ten animals were kept on pasture in summer and in open stables in winter; further, in winter the animals were allocated into one control and one feed-restricted group of five animals each to simulate natural seasonal food shortage. The annual course of the mean daily T(s) of all horses showed distinct fluctuations from a mean of 35.6±0.5°C, with higher variations in summer than in winter. Diurnal amplitudes in T(s) were highest (P<0.001) in April (12.6°C) and lowest in January (4.0°C), with a nadir around dawn and a peak around mid-day. The feed-restricted group had a significantly lower daily T(s) compared with the control group on cold winter days, with T(a) values below 0°C. Mean annual heart rate and LA followed T(a) closely. Heart rate of the feed-restricted animals significantly decreased from a mean of 52.8±8.1 beats min(-1) in summer to 29±3.9 beats min(-1) in winter and differed from the control group (P<0.001). Mean daily LA was lowest at the end of winter (7000 activity impulses day(-1)) and highest in summer (25,000 activity impulses day(-1)). Our results show that Shetland ponies exhibit signs of a winter hypometabolism indicated by reduced heart rate and T(s). Thus, domesticated horses seem to have maintained the capacity for seasonal adaptation to environmental conditions by seasonal fluctuations in their metabolic rate. PMID:22399650

Brinkmann, Lea; Gerken, Martina; Riek, Alexander

2012-04-01

318

Effects of Individual Pre-Fledging Traits and Environmental Conditions on Return Patterns in Juvenile King Penguins  

PubMed Central

Despite the importance of early life stages in individuals' life history and population dynamics, very few studies have focused on the constraints to which these juvenile traits are subjected. Based on 10 years of automatic monitoring of over 2500 individuals, we present the first study on the effects of environmental conditions and individual pre-fledging traits on the post-fledging return of non-banded king penguins to their natal colony. Juvenile king penguins returned exclusively within one of the three austral summers following their departure. A key finding is that return rates (range 68–87%) were much higher than previously assumed for this species, importantly meaning that juvenile survival is very close to that of adults. Such high figures suggest little juvenile dispersal, and selection occurring mostly prior to fledging in king penguins. Pre-fledging conditions had a strong quadratic impact on juvenile return rates. As expected, cohorts reared under very unfavourable years (as inferred by the breeding success of the colony) exhibited low return rates but surprisingly, so did those fledged under very favourable conditions. Juvenile sojourns away from the colony were shorter under warm conditions and subsequent return rates higher, suggesting a positive effect of climate warming. The longer the post-fledging trip (1, 2 or 3 years), the earlier in the summer birds returned to their natal colony and the longer they stayed before leaving for the winter journey. The presence of juveniles in the colony was more than twice the duration required for moulting purposes, yet none attempted breeding in the year of their first return. Juvenile presence in the colony may be important for acquiring knowledge on the social and physical colonial environment and may play an important part in the learning process of mating behaviour. Further studies are required to investigate its potential implications on other life-history traits such as recruitment age. PMID:21687715

Saraux, Claire; Viblanc, Vincent A.; Hanuise, Nicolas; Le Maho, Yvon; Le Bohec, Céline

2011-01-01

319

Chemical and physical environmental conditions underneath mat- and canopy-forming macroalgae, and their effects on understorey corals.  

PubMed

Disturbed coral reefs are often dominated by dense mat- or canopy-forming assemblages of macroalgae. This study investigated how such dense macroalgal assemblages change the chemical and physical microenvironment for understorey corals, and how the altered environmental conditions affect the physiological performance of corals. Field measurements were conducted on macroalgal-dominated inshore reefs in the Great Barrier Reef in quadrats with macroalgal biomass ranging from 235 to 1029 g DW m(-2) dry weight. Underneath mat-forming assemblages, the mean concentration of dissolved oxygen was reduced by 26% and irradiance by 96% compared with conditions above the mat, while concentrations of dissolved organic carbon and soluble reactive phosphorous increased by 26% and 267%, respectively. The difference was significant but less pronounced under canopy-forming assemblages. Dissolved oxygen declined and dissolved inorganic carbon and alkalinity increased with increasing algal biomass underneath mat-forming but not under canopy-forming assemblages. The responses of corals to conditions similar to those found underneath algal assemblages were investigated in an aquarium experiment. Coral nubbins of the species Acropora millepora showed reduced photosynthetic yields and increased RNA/DNA ratios when exposed to conditions simulating those underneath assemblages (pre-incubating seawater with macroalgae, and shading). The magnitude of these stress responses increased with increasing proportion of pre-incubated algal water. Our study shows that mat-forming and, to a lesser extent, canopy-forming macroalgal assemblages alter the physical and chemical microenvironment sufficiently to directly and detrimentally affect the metabolism of corals, potentially impeding reef recovery from algal to coral-dominated states after disturbance. Macroalgal dominance on coral reefs therefore simultaneously represents a consequence and cause of coral reef degradation. PMID:20856882

Hauri, Claudine; Fabricius, Katharina E; Schaffelke, Britta; Humphrey, Craig

2010-01-01

320

Chemical and Physical Environmental Conditions Underneath Mat- and Canopy-Forming Macroalgae, and Their Effects on Understorey Corals  

PubMed Central

Disturbed coral reefs are often dominated by dense mat- or canopy-forming assemblages of macroalgae. This study investigated how such dense macroalgal assemblages change the chemical and physical microenvironment for understorey corals, and how the altered environmental conditions affect the physiological performance of corals. Field measurements were conducted on macroalgal-dominated inshore reefs in the Great Barrier Reef in quadrats with macroalgal biomass ranging from 235 to 1029 g DW m?2 dry weight. Underneath mat-forming assemblages, the mean concentration of dissolved oxygen was reduced by 26% and irradiance by 96% compared with conditions above the mat, while concentrations of dissolved organic carbon and soluble reactive phosphorous increased by 26% and 267%, respectively. The difference was significant but less pronounced under canopy-forming assemblages. Dissolved oxygen declined and dissolved inorganic carbon and alkalinity increased with increasing algal biomass underneath mat-forming but not under canopy-forming assemblages. The responses of corals to conditions similar to those found underneath algal assemblages were investigated in an aquarium experiment. Coral nubbins of the species Acropora millepora showed reduced photosynthetic yields and increased RNA/DNA ratios when exposed to conditions simulating those underneath assemblages (pre-incubating seawater with macroalgae, and shading). The magnitude of these stress responses increased with increasing proportion of pre-incubated algal water. Our study shows that mat-forming and, to a lesser extent, canopy-forming macroalgal assemblages alter the physical and chemical microenvironment sufficiently to directly and detrimentally affect the metabolism of corals, potentially impeding reef recovery from algal to coral-dominated states after disturbance. Macroalgal dominance on coral reefs therefore simultaneously represents a consequence and cause of coral reef degradation. PMID:20856882

Hauri, Claudine; Fabricius, Katharina E.; Schaffelke, Britta; Humphrey, Craig

2010-01-01

321

Flavor of cold-hardy grapes: impact of berry maturity and environmental conditions.  

PubMed

Since the arrival on the market of high-quality cold-hardy grape varieties, northern winemaking has been developing tremendously in countries traditionally unsuited for grape and wine production. Cold-hardy grapes are mainly interspecific hybrids of Vitis vinifera with Vitis labrusca and Vitis riparia , making their chemical composition distinct from that of V. vinifera varieties traditionally used for winemaking and therefore limiting the use of current knowledge about V. vinifera varieties in the assessment of grape maturity. Consequently, to evaluate the flavor development of cold-hardy grapes in the province of Quebec, Canada, the ripening of Frontenac and Marquette berries in two vineyards located in the southwest (SW) and northeast (NE) areas of the province, starting at the beginning of veraison, was studied. Quality attributes, phenolic compounds, and aroma profiles showed significant changes during maturation. Although full maturity was reached for both Frontenac and Marquette in the SW vineyard (1380 accumulated growing degree days, based on 10 °C), the accumulation of 1035 growing degree days was not sufficient to fully ripen Frontenac and Marquette in the NE vineyard. Principal component analysis showed different ripening patterns for the two studied locations. The longer veraison in the SW vineyard resulted in higher quality attributes and higher flavor development for both Frontenac and Marquette. Under the colder conditions in the NE vineyard, metabolite accumulation was driven primarily by berry growth, and flavor development was limited. Besides growing degree days and technological parameters (total soluble solids, pH, titratable acidity), which provide significant guidelines for maturity assessment in cold climate, phenolic maturity may be followed by the accumulation of hydroxycinnamic esters and flavonoids, although the impact of these compound classes on quality remains to be determined in cold-climate wines. In both Frontenac and Marquette, aromatic maturity was best assessed using the ratio of cis-3-hexenol to trans-2-hexenal, which showed a constant decrease until maturity. Interestingly, a shift in C6 compound profile, illustrated by the progression of the sum of C6 compounds respectively produced from linoleic (C18:2; hexanal and 1-hexanol) and ?-linolenic (C18:3; trans-2-hexenol and cis-3-hexenol) acids occurred during ripening, with ?-linolenic acid (C18:3) degradation products decreasing in both varieties as maturation approached. At harvest, aroma profiles of both Frontenac and Marquette were dominated by C6 compounds (hexanal, trans-2-hexenal, 1-hexanol, cis-3-hexenol, and hexanoic acid), acetic acid, ?-damascenone, and 2-phenylethanol, with Marquette additionally showing significant levels of monoterpenes (linalool, geraniol, and ?-citral) and 1-octen-3-ol. PMID:24151907

Pedneault, Karine; Dorais, Martine; Angers, Paul

2013-11-01

322

4.11 Summary and Conclusions  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Section '4.11 Summary and Conclusions' of the Chapter '4 Dosimetry in Nuclear Medicine Diagnosis and Therapy'.

Noßke, D.; Mattsson, S.; Johansson, L.

323

A MultipleConclusion Specification Logic  

E-print Network

Forum: A Multiple­Conclusion Specification Logic Dale Miller Computer Science Department University the design of a number of logic programming languages. Two such languages, â??Prolog and its linear logic­order programming) but lack primitives for concurrency. The logic programming language, LO (Lin­ ear Objects) [2

Miller, Dale

324

A Multiple-Conclusion Specification Logic  

E-print Network

Forum: A Multiple-Conclusion Specification Logic Dale Miller Computer Science Department University the design of a number of logic programming languages. Two such languages, Prolog and its linear logic-order programming) but lack primitives for concurrency. The logic programming language, LO (Lin- ear Objects) [2

Miller, Dale

325

Influence of Variable Environmental Conditions on Presence and Concentration of Energetic Chemicals Near Soil Surface in the Vadoze Zone  

NASA Astrophysics Data System (ADS)

Many explosive-related compounds (ERCs) are found near the soil-atmospheric surface in sites containing buried explosive devices, such as landmines and unexploded ordnance, detonation-residual, and munitions residues from explosive manufacturing facilities. Accurate assessment of the fate and transport processes is essential for predicting their movement to the surface, groundwater, or any other important environmental compartment. The transport processes controlling the direction and magnitude of the movement, and chemical and physical processes controlling the fate of the chemicals vary with environmental conditions. This research addresses the effect of variable rainfall, evaporation, temperature, and solar radiation on fate and transport of 2,4,6-Trinitrotoluene (TNT), 2,4-Dinitrotoluene (DNT), and other related chemicals in partially saturated soil. Experiments have been conducted in a laboratory-scale 3D SoilBed placed inside an environmental chamber equipped with rainfall and solar radiation simulators, and temperature control settings. The SoilBed was packed with a sandy soil. Experiments have been conducted by burying a TNT/DNT source, simulating a landmine, and applying different rainfall and light radiation cycles while monitoring DNT, TNT, and other related ERCs solute concentrations temporally and spatially within the SoilBed. Experiments include different source characteristics, rainfall intensities, temperatures, and radiation cycles to evaluate their effect on the detection and movement of ERC in soils in both aqueous and vapor phases. Temporal and spatial data has been analyzed comparatively and quantitatively. Comparative analysis was developed using surfer®- and voxler®-generated images and 3D visualization models applying spatial interpolation and masking methods. Single and multi-variable statistical analysis has been employed to determine the most important factors affecting the fate, transport and detection of ERC near soil-atmospheric surfaces. Results show that rainfall, radiation, and temperature variations influence the presence, transport, and concentrations of TNT and DNT near the soil surface. Higher concentrations are observed near the end of rainfall events, both in the aqueous and gaseous phases. Higher rainfall intensity results in higher presence and concentrations. Lower TNT and DNT concentrations than their solubility limit indicate rate-limited mass transfer, dissolution limitations, and dilution processes. Radiation events and higher atmospheric temperatures result in greater presence and concentrations of DNT and TNT, indicating influence of these factors on fate and transport processes. TNT degradation by-products measured mostly in the upper segments of the SoilBed, suggest degradation processes resulting from radiation-induced conditions near the soil-atmospheric surface. Although the ERC source consists of equal mass of TNT and DNT, greater detection density and concentrations are observed for DNT. A generalized linear mixed statistical model has been applied to quantify the effect of environmental conditions on ERC detection and concentrations. The statistical analysis indicates that rainfall events and related water contents are the most influential factors affecting the presence and concentrations of ERCs in the aqueous and gaseous phase. Solar radiation, and related heat flux, is the second most influential parameter. Although atmospheric temperature influence the presence and concentration of ERCs in soils, it is the least influential parameter.

Anaya, A. A.; Padilla, I. Y.

2008-12-01

326

Environmental Conditions during Breeding Modify the Strength of Mass-Dependent Carry-Over Effects in a Migratory Bird  

PubMed Central

In many animals, processes occurring in one season carry over to influence reproductive success and survival in future seasons. The strength of such carry-over effects is unlikely to be uniform across years, yet our understanding of the processes that are capable of modifying their strength remains limited. Here we show that female light-bellied Brent geese with higher body mass prior to spring migration successfully reared more offspring during breeding, but only in years where environmental conditions during breeding were favourable. In years of bad weather during breeding, all birds suffered reduced reproductive output irrespective of pre-migration mass. Our results suggest that the magnitude of reproductive benefits gained by maximising body stores to fuel breeding fluctuates markedly among years in concert with conditions during the breeding season, as does the degree to which carry-over effects are capable of driving variance in reproductive success among individuals. Therefore while carry-over effects have considerable power to drive fitness asymmetries among individuals, our ability to interpret these effects in terms of their implications for population dynamics is dependent on knowledge of fitness determinants occurring in subsequent seasons.  PMID:24143258

Harrison, Xavier A.; Hodgson, David J.; Inger, Richard; Colhoun, Kendrew; Gudmundsson, Gudmundur A.; McElwaine, Graham; Tregenza, Tom; Bearhop, Stuart

2013-01-01

327

Prediction of Hydrolysis Pathways and Kinetics for Antibiotics under Environmental pH Conditions: A Quantum Chemical Study on Cephradine.  

PubMed

Understanding hydrolysis pathways and kinetics of many antibiotics that have multiple hydrolyzable functional groups is important for their fate assessment. However, experimental determination of hydrolysis encounters difficulties due to time and cost restraint. We employed the density functional theory and transition state theory to predict the hydrolysis pathways and kinetics of cephradine, a model of cephalosporin with two hydrolyzable groups, two ionization states, two isomers and two nucleophilic attack directions. Results showed that the hydrolysis of cephradine at pH = 8.0 proceeds via opening of the ?-lactam ring followed by intramolecular amidation. The predicted rate constants at different pH conditions are of the same order of magnitude as the experimental values, and the predicted products are confirmed by experiment. This study identified a catalytic role of the carboxyl group in the hydrolysis, and implies that the carboxyl group also plays a catalytic role in the hydrolysis of other cephalosporin and penicillin antibiotics. This is a first attempt to quantum chemically predict hydrolysis of an antibiotic with complex pathways, and indicates that to predict hydrolysis products under the environmental pH conditions, the variation of the rate constants for different pathways with pH should be evaluated. PMID:25590945

Zhang, Haiqin; Xie, Hongbin; Chen, Jingwen; Zhang, Shushen

2015-02-01

328

Lilium spp. pollen in China (Liliaceae): Taxonomic and Phylogenetic Implications and Pollen Evolution Related to Environmental Conditions  

PubMed Central

Recent molecular and karyologic studies have significantly modified delimitation of Lilium. However, despite the importance of pollen evolution in the genus comprehensive studies with electron microscopy and evaluation of pollen evolution are lacking. Therefore, we studied pollen morphology in a sample of 65 individuals from 37 taxa covering all the sections distributed in the world, using scanning electron microscopy. Our collection of 49 individuals from 21 taxa covering all five sections in China was also included in the database. We found pollen tetrads in L. bakerianum. Based on present and previous studies, our results suggest that pollen from L. formosanum should be classified as a new type, Formosanum. Combined with morphological and molecular evidence, pollen sculpture patterns appear to reflect phylogenetic relationships and are useful for species or subsection delimitation. Based on a comprehensive survey and correlation with potential functional implications, we propose the following hypothesis: evolution of an exine sculpture shows pollen type trends from Martagon ? Callose ? Concolor ? Formosanum. The evolutionary trend regarding pollen sculpture and size could be related to selective pressure to adapt to environmental conditions. Pollen size and shape showed a significantly positive correlation with annual precipitation, and smaller pollen grains appear to adapt better in habitats with extreme conditions. Evolution trends in exine sculpture do not appear to be definitively correlated with pollen size and shape. PMID:24498208

Du, Yun-peng; Wei, Chi; Wang, Zhong-xuan; Li, Shuang; He, Heng-bin; Jia, Gui-xia

2014-01-01

329

Existence of anticorrelations for local field potentials recorded from mice reared in standard condition and environmental enrichment  

NASA Astrophysics Data System (ADS)

In the present paper, we analyze local field potentials (LFPs) recorded from the secondary motor cortex (M2) and primary visual cortex (V1) of freely moving mice reared in environmental enrichment (EE) and standard condition (SC). We focus on the scaling properties of the signals by using an integrated approach combining three different techniques: the Higuchi method, detrended fluctuation analysis, and power spectrum. Each technique provides direct or indirect estimations of the Hurst exponent H and this prevents spurious identification of scaling properties in time-series analysis. It is well known that the power spectrum of an LFP signal scales as 1 /f? with ? >0 . Our results indicate the existence of a particular power spectrum scaling law 1 /f? with ? <0 for low frequencies (f <4 Hz) for both SC and EE rearing conditions. This type of scaling behavior is associated to the presence of anticorrelation in the corresponding LFP signals. Moreover, since EE is an experimental protocol based on the enhancement of sensorimotor stimulation, we study the possible effects of EE on the scaling properties of secondary motor cortex (M2) and primary visual cortex (V1). Notably, the difference between Hurst's exponents in EE and SC for individual cortical regions (M2) and (V1) is not statistically significant. On the other hand, using the detrended cross-correlation coefficient, we find that EE significantly reduces the functional coupling between secondary motor cortex (M2) and visual cortex (V1).

Vallone, F.; Cintio, A.; Mainardi, M.; Caleo, M.; Di Garbo, A.

2015-01-01

330

Plasma cortisol and faecal cortisol metabolites concentrations in stereotypic and non-stereotypic horses: do stereotypic horses cope better with poor environmental conditions?  

PubMed Central

Background Stereotypic behaviours, i.e. repetitive behaviours induced by frustration, repeated attempts to cope and/or brain dysfunction, are intriguing as they occur in a variety of domestic and captive species without any clear adaptive function. Among the different hypotheses, the coping hypothesis predicts that stereotypic behaviours provide a way for animals in unfavourable environmental conditions to adjust. As such, they are expected to have a lower physiological stress level (glucocorticoids) than non-stereotypic animals. Attempts to link stereotypic behaviours with glucocorticoids however have yielded contradictory results. Here we investigated correlates of oral and motor stereotypic behaviours and glucocorticoid levels in two large samples of domestic horses (NStudy1 = 55, NStudy2 = 58), kept in sub-optimal conditions (e.g. confinement, social isolation), and already known to experience poor welfare states. Each horse was observed in its box using focal sampling (study 1) and instantaneous scan sampling (study 2). Plasma samples (collected in study 1) but also non-invasive faecal samples (collected in both studies) were retrieved in order to assess cortisol levels. Results Results showed that 1) plasma cortisol and faecal cortisol metabolites concentrations did not differ between horses displaying stereotypic behaviours and non-stereotypic horses and 2) both oral and motor stereotypic behaviour levels did not predict plasma cortisol or faecal cortisol metabolites concentrations. Conclusions Cortisol measures, collected in two large samples of horses using both plasma sampling as well as faecal sampling (the latter method minimizing bias due to a non-invasive sampling procedure), therefore do not indicate that stereotypic horses cope better, at least in terms of adrenocortical activity. PMID:23289406

2013-01-01

331

Conclusions 8.1 Moment Closures in One Dimension  

E-print Network

Chapter 8 Conclusions 8.1 Moment Closures in One Dimension A general linear closure­fluid approach to obtaining fluid moment closures for collisionless plasmas (Hammett and Perkins 1990). The n closure coefficients for the n­moment system are computed using conditions obtained by matching

Hammett, Greg

332

Conclusiveness of natural languages and recognition of images  

SciTech Connect

The conclusiveness is investigated using recognition processes and one-one correspondence between expressions of a natural language and graphs representing events. The graphs, as conceived in psycholinguistics, are obtained as a result of perception processes. It is possible to generate and process the graphs automatically, using computers and then to convert the resulting graphs into expressions of a natural language. Correctness and conclusiveness of the graphs and sentences are investigated using the fundamental condition for events representation processes. Some consequences of the conclusiveness are discussed, e.g. undecidability of arithmetic, human brain assymetry, correctness of statistical calculations and operations research. It is suggested that the group theory should be imposed on mathematical models of any real system. Proof of the fundamental condition is also presented. 14 references.

Wojcik, Z.M.

1983-01-01

333

Surface adsorption, intracellular accumulation and compartmentalization of Pb(II) in batch-operated lagoons with Salvinia minima as affected by environmental conditions, EDTA and nutrients  

Microsoft Academic Search

The effects of environmental factors and nutrients on the various possible removal mechanisms (surface adsorption, intracellular\\u000a accumulation and precipitation to sediments) and partitioning of lead among various compartments (plant biomass, water column\\u000a and sediments) in Salvinia minima batch-operated lagoons, were evaluated. Surface adsorption was found to be the predominant mechanism for Pb(II) removal under\\u000a all environmental conditions tested in the

Eugenia J. Olguín; Gloria Sánchez-Galván; Teresa Pérez-Pérez; Arith Pérez-Orozco

2005-01-01

334

Characterization of a novel carbonic anhydrase from freshwater pearl mussel Hyriopsis cumingii and the expression profile of its transcript in response to environmental conditions.  

PubMed

Gene encoding for ?-carbonic anhydrases (?-CAs) and their functions in fundamental metabolism and biomineralization are widely identified in mollusks. However, the transcriptional regulation of ?-CA genes in response to various environmental conditions remains unknown. In the present study, we characterized a cDNA encoding for an ?-CA (HcCA) from the freshwater pearl mussel Hyriopsis cumingii. The spatial and temporal expression patterns of HcCA indicate that this gene is mainly expressed in the mantle of juvenile mussels. The expression profile of HcCA under various environmental conditions reveals that the transcription of HcCA is significantly regulated by Ca(2+) concentration, water temperature, pH and air exposure. Our results suggest that HcCA is a crucial target gene by which the external environmental conditions affecting shell growth and pH homeostasis of H. cumingii. PMID:24853200

Ren, Gang; Wang, Yan; Qin, Jianguang; Tang, Jinyu; Zheng, Xiafei; Li, Youming

2014-08-01

335

Transcriptome Sequencing Reveals the Virulence and Environmental Genetic Programs of Vibrio vulnificus Exposed to Host and Estuarine Conditions  

PubMed Central

Vibrio vulnificus is a natural inhabitant of estuarine waters worldwide and is of medical relevance due to its ability to cause grievous wound infections and/or fatal septicemia. Genetic polymorphisms within the virulence-correlated gene (vcg) serve as a primary feature to distinguish clinical (C-) genotypes from environmental (E-) genotypes. C-genotypes demonstrate superior survival in human serum relative to E-genotypes, and genome comparisons have allowed for the identification of several putative virulence factors that could potentially aid C-genotypes in disease progression. We used RNA sequencing to analyze the transcriptome of C-genotypes exposed to human serum relative to seawater, which revealed two divergent genetic programs under these two conditions. In human serum, cells displayed a distinct “virulence profile” in which a number of putative virulence factors were upregulated, including genes involved in intracellular signaling, substrate binding and transport, toxin and exoenzyme production, and the heat shock response. Conversely, the “environmental profile” exhibited by cells in seawater revealed upregulation of transcription factors such as rpoS, rpoN, and iscR, as well as genes involved in intracellular signaling, chemotaxis, adherence, and biofilm formation. This dichotomous genetic switch appears to be largely governed by cyclic-di-GMP signaling, and remarkably resembles the dual life-style of V. cholerae as it transitions from host to environment. Furthermore, we found a “general stress response” module, known as the stressosome, to be upregulated in seawater. This signaling system has been well characterized in Gram-positive bacteria, however its role in V. vulnificus is not clear. We examined temporal gene expression patterns of the stressosome and found it to be upregulated in natural estuarine waters indicating that this system plays a role in sensing and responding to the environment. This study advances our understanding of gene regulation in V. vulnificus, and brings to the forefront a number of previously overlooked genetic networks. PMID:25489854

Williams, Tiffany C.; Blackman, Elliot R.; Morrison, Shatavia S.; Gibas, Cynthia J.; Oliver, James D.

2014-01-01

336

A holistic evaluation of risks in coastal regions under changing climatic, environmental and socioeconomic conditions: the Theseus Decision Support System.  

NASA Astrophysics Data System (ADS)

There is a general acceptance that global changes associated with natural hazards and socioeconomic processes are occurring at a faster pace than ever, with deep implications in terms of risk exposure and environmental impact. The capacity of coastal areas to adapt and react to these changes will be a key factor in the future preservation of life standards and represents a great challenge for politicians, scientists and professionals at any level. Within the large scope of Theseus Project (EU 7th Framework Program), one of the main objectives is to design a tool to help decision makers in defining optimal strategies to minimize risks within a certain city or coastal area in a three-fold sense: economic losses, human damages and environmental impacts. The resulting software, the Theseus-DSS, links the most relevant physical processes (waves, sea-levels, hard and soft structures, coastal erosion and inland flooding) with the potential impact zones (marine and inland), considering their functions (ecosystems) and uses (economic units), and the dependence of this functions and uses upon the prevailing physical conditions. The new software tries to fill a gap among the existing tools, based on the following pillars: • Seamless integration of disciplines: physics, engineering, ecology, social sciences and economy. • Intermediate spatial scales (1- 10 km) and medium-to- long time spans (1-10 years). • Decision-making based on a balance between deterministic models and expert, discussion-based assumptions. The user of the Theseus-DSS will be able either to check the consequences of predefined scenarios at a particular study site, or to create user-defined scenarios, run them and compare the results with other scenarios. The results are expressed, locally and at an aggregate level, in the three aforementioned dimensions: economic losses (€/year), mean annual expected live losses (persons/year) and impact on habitats (null, low, medium and high).

Losada, I. J.; Garcia Alonso, E.; Mendez, F. J.; Zanuttigh, B.; Nicholls, R. J.; Thompson, R.; Vanderlinden, J. P.; Fernandez, F.; Ondiviela, B.; Diaz-Simal, P.; Bagli, S.

2012-04-01

337

Mitigation potential of horizontal ground coupled heat pumps for current and future climatic conditions: UK environmental modelling and monitoring studies  

NASA Astrophysics Data System (ADS)

An increased uptake of alternative low or non-CO2 emitting energy sources is one of the key priorities for policy makers to mitigate the effects of environmental change. Relatively little work has been undertaken on the mitigation potential of Ground Coupled Heat Pumps (GCHPs) despite the fact that a GCHP could significantly reduce CO2 emissions from heating systems. It is predicted that under climate change the most probable scenario is for UK temperatures to increase and for winter rainfall to become more abundant; the latter is likely to cause a general rise in groundwater levels. Summer rainfall may reduce considerably, while vegetation type and density may change. Furthermore, recent studies underline the likelihood of an increase in the number of heat waves. Under such a scenario, GCHPs will increasingly be used for cooling as well as heating. These factors will affect long-term performance of horizontal GCHP systems and hence their economic viability and mitigation potential during their life span ( 50 years). The seasonal temperature differences encountered in soil are harnessed by GCHPs to provide heating in the winter and cooling in the summer. The performance of a GCHP system will depend on technical factors (heat exchanger (HE) type, length, depth, and spacing of pipes), but also it will be determined to a large extent by interactions between the below-ground parts of the system and the environment (atmospheric conditions, vegetation and soil characteristics). Depending on the balance between extraction and rejection of heat from and to the ground, the soil temperature in the neighbourhood of the HE may fall or rise. The GROMIT project (GROund coupled heat pumps MITigation potential), funded by the Natural Environment Research Council (UK), is a multi-disciplinary research project, in collaboration with EarthEnergy Ltd., which aims to quantify the CO2 mitigation potential of horizontal GCHPs. It considers changing environmental conditions and combines model predictions of soil moisture content and soil temperature with measurements at different GCHP locations over the UK. The combined effect of environment dynamics and horizontal GCHP technical properties on long-term GCHP performance will be assessed using a detailed land surface model (JULES: Joint UK Land Environment Simulator, Meteorological Office, UK) with additional equations embedded describing the interaction between GCHP heat exchangers and the surrounding soil. However, a number of key soil physical processes are currently not incorporated in JULES, such as groundwater flow, which, especially in lowland areas, can have an important effect on the heat flow between soil and HE. Furthermore, the interaction between HE and soil may also cause soil vapour and moisture fluxes. These will affect soil thermal conductivity and hence heat flow between the HE and the surrounding soil, which will in turn influence system performance. The project will address these issues. We propose to drive an improved version of JULES (with equations to simulate GCHP exchange embedded), with long-term gridded (1 km) atmospheric, soil and vegetation data (reflecting current and future environmental conditions) to reliably assess the mitigation potential of GCHPs over the entire domain of the UK, where uptake of GCHPs has been low traditionally. In this way we can identify areas that are most suitable for the installation of GCHPs. Only then recommendations can be made to local and regional governments, for example, on how to improve the mitigation potential in less suitable areas by adjusting GCHP configurations or design.

García González, Raquel; Verhoef, Anne; Vidale, Pier Luigi; Gan, Guohui; Wu, Yupeng; Hughes, Andrew; Mansour, Majdi; Blyth, Eleanor; Finch, Jon; Main, Bruce

2010-05-01

338

Effects of Varying Environmental Conditions on Biological Control of Fusarium Wilt of Tomato by Nonpathogenic Fusarium spp.  

PubMed

ABSTRACT The influence of varying environmental and cropping conditions including temperature, light, soil type, pathogen isolate and race, and cultivar of tomato on biological control of Fusarium wilt of tomato by isolates of nonpathogenic Fusarium oxysporum (CS-20 and CS-24) and F. solani (CS-1) was evaluated in greenhouse and growth chamber experiments. Liquid spore suspensions (10(6)/ml) of the biocontrol isolates were applied to soilless potting mix at the time of tomato seeding, and the seedlings were transplanted into pathogen-infested field soil 2 weeks later. Temperature regimes ranging from 22 to 32 degrees C significantly affected disease development and plant physiological parameters. Biocontrol isolate CS-20 significantly reduced disease at all temperature regimes tested, yielding reductions of disease incidence of 59 to 100% relative to pathogen control treatments. Isolates CS-24 and CS-1 reduced disease incidence in the greenhouse and at high temperatures, but were less effective at the optimum temperature for disease development (27 degrees C). Growing plants under shade (50% of full light) versus full light affected some plant growth parameters, but did not affect the efficacy of biocontrol of any of the three bio-control isolates. Isolate CS-20 effectively reduced disease incidence (56 to 79% reduction) in four different field soils varying in texture (sandy to clayey) and organic matter content (0 to 3.2%). Isolate CS-1 reduced disease in the sandy and loamy soils (49 to 66% reduction), but was not effective in a heavy clay soil. Both CS-1 and CS-20 were equally effective against all three races of the pathogen, as well as multiple isolates of each race (48 to 66% reduction in disease incidence). Both isolates, CS-1 and CS-20, were equally effective in reducing disease incidence (66 to 80% reduction) by pathogenic races 1, 2, and 3 on eight different tomato cultivars containing varying levels of inherent resistance to Fusarium wilt (susceptible, resistant to race 1, or resistant to races 1 and 2). These results demonstrate that both these Fusarium isolates, and particularly CS-20, can effectively reduce Fusarium wilt disease of tomato under a variety of environmental conditions and have potential for further development. PMID:18944240

Larkin, Robert P; Fravel, Deborah R

2002-11-01

339

Summary and Conclusions 9.1 Summary  

E-print Network

plate tectonics. Several lines of evidence indicate internal temperatures for the early Earth that of the Earth. For example, no evidence of recent plate tectonics is found on either planet. In this thesis, the conditions under which plate tectonics and alternative geodynamic regimes may operate were investigated

van Thienen, Peter

340

Influence of environmental factors on dissolved nitrate stable isotopes under denitrifying conditions - carbon sources and water isotopes  

NASA Astrophysics Data System (ADS)

Stable isotopes in dissolved nitrate are regularly used to identify sources of nitrate contamination in aquifers and water bodies. A dual isotope plot of 15N and 18O in nitrate can provide good evidence of the origin of such pollution as various sources have different isotopic signatures. Microbial denitrification changes both isotopic values by removing nitrate with lighter isotopes first, thereby increasing ?18O as well as ?15N. This change can distort the determination of sources but also has the potential to be used to identify and quantify microbial denitrification. Previous studies found a wide range of enrichment factors (?) that did not allow conclusions towards the extent of microbial denitrification. However, it was found that during denitrification at each respective field site or laboratory experiment, there was a constant ratio in increase of the values of ?18O in relation to ?15N. That ratio was, however, not constant across field sites and the values published range from below 0.5 to more than 1.0. The reasons for these variations in enrichment factors and relative enrichment of oxygen compared to nitrogen are yet unknown. We conducted microcosm experiments with three different bacterial species to elucidate possible influences of environmental factors on these parameters. As a result we conclude that the type of carbon source available to denitrifying bacteria can play a role in the value of the enrichment factors, but not in the relative enrichment of the two isotopes. Specifically we found that complex hydrocarbons (toluene, benzoate) produce significantly different enrichment factors in nitrate than a simple hydrocarbon substrate (acetate). The relative enrichment of ?18O compared to ?15N was 0.86. We hypothesise that this influence is based on a variation in process kinetics of cross-membrane nitrate transport in relation to intracellular nitrate reduction. The core of the hypothesis is that nitrate transport into the cell becomes rate limiting as a result of a carbon source induced change in cell membrane composition. The apparent kinetic isotope effect observed outside the cell is then changed as transport-related isotope effects dominate the observations. In addition, a possible effect of water ?18O values on the ?18O of dissolved nitrate was researched. Intermediary nitrite is known to exchange oxygen atoms with water; a reverse reaction of the nitrate reducing step could thus influence the oxygen isotope composition of dissolved nitrate without changing the nitrogen isotopic composition in the same way. Such a process was already shown for sulfate reduction. By adding 18O-labelled water to microcosm experiments, we could show that such an exchange exists for selected microorganisms. The environmental implications of this result is discussed.

Wunderlich, A.; Meckenstock, R.; Einsiedl, F.

2012-04-01

341

Genetic diversity of root nodulating bacteria associated with Retama sphaerocarpa in sites with different soil and environmental conditions.  

PubMed

The genetic diversity of root nodulating bacteria isolated from Retama sphaerocarpa was studied using BOX-A1R PCR and phylogenetic analysis of the 16S rRNA region, as well as the housekeeping genes atpD, glnII and recA. A total of 193 isolates were obtained from eight different sites with different soil and environmental conditions in the Iberian Peninsula. These isolates corresponded to 31 different strains that successfully nodulated R. sphaerocarpa seedlings in reinoculation trials. About one-third of the strains clustered with B. canariense or B. cytisi within Bradyrhizobium group I. The remaining strains clustered with B. elkanii/B. pachyrhizi within Bradyrhizobium group II or in separate clades that could represent new lineages. Based on the 16S rRNA and combined atpD+glnII+recA sequences, two to three lineages of root nodulating bacteria were found at each sampling site, except for Collado Garcia where five species were detected. B. canariense and B. elkanii/B. pachyrhizi were the most abundant species, whereas the least abundant were those related to B. retamae and a putative new lineage. B. canariense was found only in soils with neutral and acid pH, whereas B. retamae was the dominant species in alkaline soils. PMID:24461714

Rodríguez-Echeverría, Susana; Moreno, Silvia; Bedmar, Eulogio J

2014-06-01

342

Mytilus galloprovincialis as a bioindicator of environmental conditions: the case of the eastern coast of the Adriatic Sea.  

PubMed

The marine mussel Mytilus galloprovincialis lives attached to the surface of hard substrata, where its exposure and relative immobility allow it to record changes in ambient seawater. It is also found along the eastern coast of the Adriatic Sea. Oxygen and carbon isotopes were analysed for calcite and aragonite in separate shell layers, while major, minor and trace elements in the bulk shell were analysed to evaluate environmental conditions such as the temperature of carbonate deposition, freshwater influence and locations of anthropogenic pollution. We found that, on average, aragonite is enriched by 1.1‰ in (13)C and by 0.2‰ in (18)O compared with calcite. The calculated temperatures for M. galloprovincialis shell growth from the investigated area range from 13.4 to 20.9 °C for calcite and from 16.6 to 23.1 °C for aragonite. According to the ?(18)O and ?(13)C values of shell layers, we can separate the investigated area into three locations: those with more influence of freshwater, those with less influence of freshwater and those with marine environments. The highest concentrations of manganese, barium, boron, arsenic, nickel and chromium were observed in shells from Omis, Bacvice and Zablace (Central Adriatic) and Sv. Ivan (South Adriatic), where chemical and heavy industries are located and where sewage is known to be discharged into coastal areas. The highest concentrations of zinc, lead and copper were measured in samples from Pula, Rijeka and Gruz, where there are also ports in addition to industry. PMID:21271424

Kanduc, Tjasa; Medakovi?, Davorin; Hamer, Bojan

2011-03-01

343

Community Composition, Toxigenicity, and Environmental Conditions during a Cyanobacterial Bloom Occurring along 1,100 Kilometers of the Murray River  

PubMed Central

A cyanobacterial bloom impacted over 1,100 km of the Murray River, Australia, and its tributaries in 2009. Physicochemical conditions in the river were optimal to support a bloom at the time. The data suggest that at least three blooms occurred concurrently in different sections of the river, with each having a different community composition and associated cyanotoxin profile. Microscopic and genetic analyses suggested the presence of potentially toxic Anabaena circinalis, Microcystis flos-aquae, and Cylindrospermopsis raciborskii at many locations. Low concentrations of saxitoxins and cylindrospermopsin were detected in Anabaena and Cylindrospermopsis populations. A multiplex quantitative PCR was used, employing novel oligonucleotide primers and fluorescent TaqMan probes, to examine bloom toxigenicity. This single reaction method identified the presence of the major cyanotoxin-producing species present in these environmental samples and also quantified the various toxin biosynthesis genes. A large number of cells present throughout the bloom were not potential toxin producers or were present in numbers below the limit of detection of the assay and therefore not an immediate health risk. Potential toxin-producing cells, possessing the cylindrospermopsin biosynthesis gene (cyrA), predominated early in the bloom, while those possessing the saxitoxin biosynthesis gene (sxtA) were more common toward its decline. In this study, the concentrations of cyanotoxins measured via enzyme-linked immunosorbent assay (ELISA) correlated positively with the respective toxin gene copy numbers, indicating that the molecular method may be used as a proxy for bloom risk assessment. PMID:22081581

Al-Tebrineh, Jamal; Merrick, Chester; Ryan, David; Humpage, Andrew; Bowling, Lee

2012-01-01

344

Cloud point extraction of plutonium in environmental matrixes coupled to ICPMS and ? spectrometry in highly acidic conditions.  

PubMed

A new cloud point extraction procedure has been developed for the quantification of plutonium(IV) in environmental samples. The separation procedure can be either coupled to inductively coupled plasma mass spectrometry (ICPMS) or ? spectrometry for plutonium quantification. The method uses a combination of selective ligand (P,P'-di(2-ethylhexyl) methanediphosphonic acid (H2DEH[MDP])) and micelle shielding by bromine formation to enable quantitative extraction of Pu in highly acidic solutions. Cross-optimization of all parameters (nonionic and ionic surfactant, chelating agent, bromate, bromide, and pH) led to optimal of the extraction conditions. Figures of merit of the method for the detection using ? spectrometry and ICPMS are reported (limit of detection, limit of quantification, minimal detectable activity, and recovery). Quantitative extractions (>95%) were obtained for a wide variety of aqueous and digested samples (synthetic urine, wastewater, drinking water, seawater, and soil samples). The method features the first successful coupling between ? spectrometry and cloud point extraction and is the first demonstration of CPE suitability with metaborate fusion as a sample preparation approach, techniques used extensively in nuclear industries. PMID:24074397

Labrecque, Charles; Whitty-Léveillé, Laurence; Larivière, Dominic

2013-11-01

345

Chemical composition and anticancer activity of essential oils of Mediterranean sage (Salvia officinalis L.) grown in different environmental conditions.  

PubMed

Salvia officinalis L. can be found worldwide and its leaves are commonly used as ingredient in food industry. Sage essential oil is applied in the treatment of a range of diseases and has been shown to possess different biological activities. The objectives of our research were to study the effects of environment on crop, chemical composition and anticancer activity on S. officinalis essential oil. Sage was cultivated at eighteen experimental sites in south-central Italy (Molise) in different growing environments. The essential oils (S1-S18), extracted by hydrodistillation, were analyzed by GC and CG/MS. Results show that the main components were ?-thujone, camphor, borneol, ?-muurolene and sclareol for all the samples, but the percentages of these compounds varied depending on environmental factors such as altitude, water availability and pedo-climatic conditions. The growth-inhibitory and proapoptotic effects of the eighteen sage essential oils were evaluated in three human melanoma cell lines, A375, M14, and A2058. PMID:23291326

Russo, Alessandra; Formisano, Carmen; Rigano, Daniela; Senatore, Felice; Delfine, Sebastiano; Cardile, Venera; Rosselli, Sergio; Bruno, Maurizio

2013-05-01

346

Community composition, toxigenicity, and environmental conditions during a cyanobacterial bloom occurring along 1,100 kilometers of the Murray River.  

PubMed

A cyanobacterial bloom impacted over 1,100 km of the Murray River, Australia, and its tributaries in 2009. Physicochemical conditions in the river were optimal to support a bloom at the time. The data suggest that at least three blooms occurred concurrently in different sections of the river, with each having a different community composition and associated cyanotoxin profile. Microscopic and genetic analyses suggested the presence of potentially toxic Anabaena circinalis, Microcystis flos-aquae, and Cylindrospermopsis raciborskii at many locations. Low concentrations of saxitoxins and cylindrospermopsin were detected in Anabaena and Cylindrospermopsis populations. A multiplex quantitative PCR was used, employing novel oligonucleotide primers and fluorescent TaqMan probes, to examine bloom toxigenicity. This single reaction method identified the presence of the major cyanotoxin-producing species present in these environmental samples and also quantified the various toxin biosynthesis genes. A large number of cells present throughout the bloom were not potential toxin producers or were present in numbers below the limit of detection of the assay and therefore not an immediate health risk. Potential toxin-producing cells, possessing the cylindrospermopsin biosynthesis gene (cyrA), predominated early in the bloom, while those possessing the saxitoxin biosynthesis gene (sxtA) were more common toward its decline. In this study, the concentrations of cyanotoxins measured via enzyme-linked immunosorbent assay (ELISA) correlated positively with the respective toxin gene copy numbers, indicating that the molecular method may be used as a proxy for bloom risk assessment. PMID:22081581

Al-Tebrineh, Jamal; Merrick, Chester; Ryan, David; Humpage, Andrew; Bowling, Lee; Neilan, Brett A

2012-01-01

347

Experimental Demonstration of the Formation of Liquid Brines under Martian Polar Conditions in the Michigan Mars Environmental Chamber  

NASA Astrophysics Data System (ADS)

Liquid water is one of the necessary ingredients for the development of life as we know it. The behavior of various liquid states of H2O such as liquid brine, undercooled liquid interfacial water, subsurface melt water and ground water [1] needs to be understood in order to address the potential habitability of Mars for microbes and future human exploration. It has been shown thermodynamically that liquid brines can exist under Martian polar conditions [2, 3]. We have developed the Michigan Mars Environmental Chamber (MMEC) to simulate the entire range of Martian surface and shallow subsurface conditions with respect to temperature, pressure, relative humidity, solar radiation and soil wetness at equatorial and polar latitudes. Our experiments in the MMEC show that deliquescence of NaClO4, Mg(ClO4)2 and Ca(ClO4)2 occurs diurnally under the environmental conditions of the Phoenix landing site when these salts get in contact with water ice. Since Phoenix detected these salts and water ice at the landing site, including frost formation, it is extremely likely that deliquescence occurs at the Phoenix landing site. By layering NaClO4, Mg(ClO4)2 or Ca(ClO4)2 on top of a pure water ice slab at 800 Pa and 190 K and raising the temperature stepwise across the eutectic temperature of the perchlorate salts, we observe distinct changes in the Raman spectra of the samples when deliquescence occurs. When crossing the eutectic temperatures of NaClO4 (236 K), Mg(ClO4)2 (205 K) and Ca(ClO4)2 (199 K) [4, 5], the perchlorate band of the Raman spectrum shows a clear shift from 953 cm-1 to 936 cm-1. Furthermore, the appearance of a broad O-H vibrational stretching spectrum between 3244 cm-1 and 3580 cm-1 is another indicator of deliquescence. This process of deliquescence occurs on the order of seconds when the perchlorate salt is in contact with water ice. On the contrary, when the perchlorate salt is only subjected to water vapor in the Martian atmosphere, deliquescence was not observed within the Martian diurnal cycle. This greatly diminishes the possibility of liquid brine formation without water ice contact and has strong implications on future robotic and manned missions searching for liquid water on Mars. Acknowledgement: This research is supported by a grant from the NASA Astrobiology Program: Exobiology and Evolutionary Biology. Award #09-EXOB09-0050. References: [1] Martínez, G. M. and Renno, N. O. (2013), Water and Brines on Mars: Current Evidence and Implications for MSL, Space Sci. Rev., 175, 29-51. [2] Rennó, N. O., et al. (2009), Possible physical and thermodynamical evidence for liquid water at the Phoenix landing site, J. Geophys. Res., 114, E00E03. [3] Zorzano, M.-P., et al., Stability of liquid saline water on present day Mars, Geophys. Res. Lett., 36, L20201. [4] Hanley, J. et al. (2009), Low Temperature Aqueous Perchlorate Solutions on the Surface of Mars, Proceedings 40th Lunar and Planetary Sciences Conference, The Woodlands, TX, USA. [5] Marion, G. M. et al. (2010), Modeling Aqueous Perchlorate Chemistries with Applications to Mars, Icarus, 207, 675-685.

Fischer, Erik; Martinez, German; Elliott, Harvey; Borlina, Caue; Renno, Nilton

2014-05-01

348

Impact of Environmental Conditions (pH, Ionic Strength, And Electrolyte Type) On The Surface Charge And Aggregation Of Silver Nanoparticles Suspensions  

EPA Science Inventory

The impact of capping agents and environmental conditions (pH, ionic strength, and background electrolytes) on surface charge and aggregation potential of silver nanoparticles (AgNPs) suspensions were investigated. Capping agents are chemicals used in the synthesis of nanopartic...

349

Is there an evolutionary mismatch between the normal physiology of the human dopaminergic system and current environmental conditions in industrialized countries?  

Microsoft Academic Search

A large body of evidence has recently defined a field theory known as ‘evolutionary mismatch’, which derives its attributes largely from the fact that current environmental conditions are completely different from those in which the human central nervous system evolved. Current views on the evolutionary mismatch theory lack, however, any attempts to define which brain areas or neuronal circuits should

L Pani

2000-01-01

350

EVALUATION OF IMMOBILIZED REDOX INDICATORS AS REVERSIBLE, IN SITU REDOX SENSORS FOR DETERMINING FE(III)-REDUCING CONDITIONS IN ENVIRONMENTAL SAMPLES. (R828772)  

EPA Science Inventory

An in situ methodology based on immobilized redox indicators has been developed to determine when Fe(III)-reducing conditions exist in environmental systems. The redox indicators thionine (Thi, formal potential at pH 7 ( E 70') equals 66 mV), tol...

351

Palaeolithic use of fossil combustible linked to singular environmental conditions : the long term el Kowm record (Syria).  

NASA Astrophysics Data System (ADS)

Identifying the adaptation of hunter-gatherer communities to particular situations that provided natural resources is a major concern for multidisciplinary team studying archaeological contexts. This challenge is illustrated in the desertic El Kowm basin in central Syria by data from Hummal and El Kowm Paleolithic sites. The sites form prominent mounds at artesian springs resulting from recurrent episodes of lacustrine, limnic and aeolian sedimentation in pseudo-karstic depressions. The few meter sequences provide semi-continuous succession of archaeological levels from the Oldest Palaeolithic (Oldowan) to the early Neolithic period. This long term continuity of occupation is partly due to attracting conditions due to the profusion of water from epithermal artesian wells during periods of high water recharge. In addition, we document here the unique potential of this endoreic basin to have accumulated singular fossil combustible of high energy value during particular environmental episodes. The latter are represented by the recurrence of distinctive black organogenic facies showing a contrasting micro stratification formed of interlayered grey calcareous silty clay, dark brown organic rich clay and dull orange clay. Spatial excavation has shown the unique preservation of Palaeolithic occupation surfaces in association to the microstratified facies. High resolution sampling and multi-proxy analysis have allowed explaining the formation of the microstratified facies from rapid changes of environmental conditions in response to contrasting fluctuations of atmospheric dust loading, precipitation events, rainwater quality and evapotranspiration. Organogenic microfacies formed at different time periods share common compositional assemblage and structural behaviour: occurrence of exotic fine sand-sized debris formed of metal-rich carbonaceous components with polymer, fine charcoal, vitrous carbon, carbon fibres, and exotic rock clasts with a metal-rich carbonaceous coating; highly stable microstructure and low wettability. Based on their analytical properties, the carbonaceous polymorphs and the associated mineral components are shown to deriving from fossil combustible of stratospheric origin. The comparison with modern analogues (cf. Courty et al., 2012) has provided keys to explaining the organogenic microfacies from accumulation episodes of exotic stratospheric aerosols in response to serial meteor explosion at high altitude. Geogenic markers and microfacies pattern show four situations: (1) nearly intact ancient surfaces with pulverized carbonaceous composite debris that trace the local effects of meteor explosion ; (2) secondary concentrations expressing accumulation of stratospheric aerosols from the heavy rainfall events subsequent to the meteor explosions; (3) relictual concentrations resulting from selective accumulation of the most resistant components by chemical and physical erosion along to the fossilization; (4) human-controlled concentrations of the unusual debris indicating intentional collect, use and transformation of the singular fossil combustible and related materials. Ancient humans are thus suggested to have regularly exploited the local sources of the singular fossil combustible that formed during episodes of serial cosmic explosions. The direct effect of increased atmospheric dust loading on precipitation regime explains the apparent synchrony between occupation phases and local climate changes. These are simply two distinctive responses to a common cause. Courty, Benoît and Vaillant (2012). Possible interaction of meteor explosion with stratospheric aerosols on cloud nucleation based on 2011 observations. Geophysical Research Abstracts Vol. 14, EGU2012.

Courty, M.-A.; Le Tensorer, J.-M.; Boëda, E.; Muhesen, S.; Alsakhel, E.; Wegmüller, F.

2012-04-01

352

Characterization of condenser microphones under different environmental conditions for accurate speed of sound measurements with acoustic resonators  

SciTech Connect

Condenser microphones are more commonly used and have been extensively modeled and characterized in air at ambient temperature and static pressure. However, several applications of interest for metrology and physical acoustics require to use these transducers in significantly different environmental conditions. Particularly, the extremely accurate determination of the speed of sound in monoatomic gases, which is pursued for a determination of the Boltzmann constant k by an acoustic method, entails the use of condenser microphones mounted within a spherical cavity, over a wide range of static pressures, at the temperature of the triple point of water (273.16 K). To further increase the accuracy achievable in this application, the microphone frequency response and its acoustic input impedance need to be precisely determined over the same static pressure and temperature range. Few previous works examined the influence of static pressure, temperature, and gas composition on the microphone's sensitivity. In this work, the results of relative calibrations of 1/4 in. condenser microphones obtained using an electrostatic actuator technique are presented. The calibrations are performed in pure helium and argon gas at temperatures near 273 K and in the pressure range between 10 and 600 kPa. These experimental results are compared with the predictions of a realistic model available in the literature, finding a remarkable good agreement. The model provides an estimate of the acoustic impedance of 1/4 in. condenser microphones as a function of frequency and static pressure and is used to calculate the corresponding frequency perturbations induced on the normal modes of a spherical cavity when this is filled with helium or argon gas.

Guianvarc'h, Cecile; Pitre, Laurent [Laboratoire Commun de Metrologie LNE/Cnam, 61 rue du Landy, 93210 La Plaine Saint Denis (France); Gavioso, Roberto M.; Benedetto, Giuliana [Istituto Nazionale di Ricerca Metrologica, Strada delle Cacce 91, 10135 Turin (Italy); Bruneau, Michel [Laboratoire d'Acoustique de l'Universite du Maine UMR CNRS 6613, av. Olivier Messiaen, 72085 Le Mans Cedex 9 (France)

2009-07-15

353

SERS Properties of Different Sized and Shaped Gold Nanoparticles Biosynthesized under Different Environmental Conditions by Neurospora crassa Extract  

PubMed Central

Surface-enhanced Raman scattering (SERS) is a surface-sensitive technique that enhances Raman scattering by molecules adsorbed on rough metal surfaces. It is known that metal nanoparticles, especially gold and silver nanoparticles, exhibit great SERS properties, which make them very attractive for the development of biosensors and biocatalysts. On the other hand, the development of ecofriendly methods for the synthesis of metallic nanostructures has become the focus of research in several countries, and many microorganisms and plants have already been used to biosynthesize metallic nanostructures. However, the majority of these are pathogenic to plants or humans. Here, we report gold nanoparticles with good SERS properties, biosynthesized by Neurospora crassa extract under different environmental conditions, increasing Raman signals up to 40 times using methylene blue as a target molecule. Incubation of tetrachloroauric acid solution with the fungal extract at 60°C and a pH value of a) 3, b) 5.5, and c) 10 resulted in the formation of gold nanoparticles of a) different shapes like triangles, hexagons, pentagons etc. in a broad size range of about 10-200 nm, b) mostly quasi-spheres with some different shapes in a main size range of 6-23 nm, and c) only quasi-spheres of 3-12 nm. Analyses included TEM, HRTEM, and EDS in order to corroborate the shape and the elemental character of the gold nanoparticles, respectively. The results presented here show that these ‘green’ synthesized gold nanoparticles might have potential applicability in the field of biological sensing. PMID:24130891

Quester, Katrin; Avalos-Borja, Miguel; Vilchis-Nestor, Alfredo Rafael; Camacho-López, Marco Antonio; Castro-Longoria, Ernestina

2013-01-01

354

Toxicokinetics of perfluorooctane sulfonate in birds under environmentally realistic exposure conditions and development of a kinetic predictive model.  

PubMed

This article describes the toxicokinetics of perfluorooctane sulfonate (PFOS) in birds under low repeated dosing, equivalent to 0.085?g/kg per day, representing environmentally realistic exposure conditions. The best fitting was provided by a simple pseudo monocompartmental first-order kinetics model, regulated by two rates, with a pseudo first-order dissipation half-life of 230 days, accounting for real elimination as well as binding of PFOS to non-exchangeable structures. The calculated assimilation efficiency was 0.66 with confidence intervals of 0.64 and 0.68. The model calculations confirmed that the measured maximum concentrations were still far from the steady state situation, which for this dose regime, was estimated at a value of about 65?g PFOS/L serum achieved after a theoretical 210 weeks continuous exposure. The results confirm a very different kinetics than that observed in single-dose experiments confirming clear dose-related differences in apparent elimination rates in birds, as described for humans and monkeys; suggesting that a capacity-limited saturable process should also be considered in the kinetic behavior of PFOS in birds. Pseudo first-order kinetic models are highly convenient and frequently used for predicting bioaccumulation of chemicals in livestock and wildlife; the study suggests that previous bioaccumulation models using half-lives obtained at high doses are expected to underestimate the biomagnification potential of PFOS. The toxicokinetic parameters presented here can be used for higher-tier bioaccumulation estimations of PFOS in chickens and as surrogate values for modeling PFOS kinetics in wild bird species. PMID:25445721

Tarazona, J V; Rodríguez, C; Alonso, E; Sáez, M; González, F; San Andrés, M D; Jiménez, B; San Andrés, M I

2015-01-22

355

The negative effect of environmental geological conditions of some geo-archaeological sites of North Coast and Alexandria  

NASA Astrophysics Data System (ADS)

Three geo-archaeological sites at the North Coast and Alexandria, namely, the Alexandria wall (El Shalalat Park site), Abu Soir temple, and Marina excavations, were investigated to determine the negative impact of a salty environmental condition. The monuments suffer from rock decay of different rates. The geo-archaeological sites were built mainly from oolitic limestone blocks (i.e., the Alexandria wall at the El Shalalat Park site and Abu Soir temple) or excavated on them (i.e., Marina excavations). Field inspection and a lab analysis were carried out to understand the weathering mechanism. Salt weathering criteria such as disintegration, pitting, scaling, exfoliation, and honeycomb are observed on the Alexandria wall and upper parts of the Abu Soir temple, while dangerous cracks are detected on the Marina excavation tombs. The petrographic study of the oolitic limestone samples shows that they consist mainly of oolities and drusy sparite as a cement (oolitic grainstone). Some oolities have quartz grains as nuclei. Hydrochemical analysis shows that the total dissolved salts of extracted solutions of the North Coast quarry samples range from 539 to 686 ppm and dramatically increase (i.e., ten times) for extracted solutions from monument samples, ranging from 5395 to 6880 ppm. The dominant cation is sodium while the dominant anion is chlorine. Acid insoluble residue analysis shows that the carbonate content ranges from 89.2% to 96.4% for fresh samples from quarries and from 9.2% to 94.8% for weathered monument samples. The weight loss of the quarry oolitic limestone samples range from 30.7% to 32.7% and its physical and mechanical properties become worse after being subjected to 15 cycles of a durability simulation soundness test (using a sodium sulphate solution). Our main recommendations are to use suitable grouting for binding the cracks, high durability reconstruction rocks, and suitable cleaning methods to remove salts from the monuments.

Ibrahim, Hani; Kamh, Gamal

2005-12-01

356

Marked deleterious changes in the condition, growth and maturity schedules of Acanthopagrus butcheri (Sparidae) in an estuary reflect environmental degradation  

NASA Astrophysics Data System (ADS)

As Acanthopagrus butcheri typically completes its life within its natal estuary and possesses plastic biological characteristics, it provides an excellent model for exploring the ways and extent to which a fish species can respond to environmental changes over time. The environment of the Swan River Estuary in south-western Australia has deteriorated markedly during the last two decades, reflecting the effects of increasing eutrophication and hypoxia in the upper regions, where A. butcheri spends most of the year and spawns. In this study, the biological characteristics of A. butcheri in 2007-11 were determined and compared with those in 1993-95. Between these two periods, the condition factor for females and males of A. butcheri across their length ranges declined by 6 and 5%, respectively, and the parameters k and L? in the von Bertalanffy growth curves of both sexes underwent marked reductions. The predicted lengths of females and males at all ages ?1 year were less in 2007-11 than in 1993-95 and by over 30% less at ages 3 and 6. The ogives relating maturity to length and age typically differed between 1993-94 and 2007-10. The L50s of 156 mm for females and 155 mm for males in 2007-10 were less than the corresponding values of 174 and 172 mm in 1993-94, whereas the A50s of 2.5 years for both females and males in 2007-10 were greater than the corresponding values of 1.9 and 2.0 years in 1993-94. The above trends in condition, growth and maturity parameters between periods are consistent with hypotheses regarding the effects of increasing hypoxia on A. butcheri in offshore, deeper waters. However, as the density of A. butcheri declined in offshore, deeper waters and increased markedly in nearshore, shallow waters, density-dependent effects in the latter waters, although better oxygenated, also probably contributed to the overall reductions in growth and thus to the changes in the lengths and ages at maturity.

Cottingham, Alan; Hesp, S. Alex; Hall, Norman G.; Hipsey, Matthew R.; Potter, Ian C.

2014-08-01

357

ENVIRONMENTAL RESEARCH BRIEF: WASTE REDUCTION ACTIVITIES AND OPTIONS FOR A MANUFACTURER OF ROOM AIR CONDITIONING UNITS AND HUMIDIFIERS.  

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) funded a project with the New Jersey Department of Environmental Protection and Energy (NJDEPE), to assist in conducting waste minimization assessments at thirty small to medium sized businesses in the state of New Jersey. One of th...

358

ENVIRONMENTAL RESEARCH BRIEF: WASTE REDUCTION ACTIVITIES AND OPTIONS FOR A MANUFACTURER OF ROOM AIR CONDITIONING UNITS AND HUMIDIFIERS  

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) funded a project with the New Jersey Department of Environmental Protection and Energy (NJDEPE) ,to assist in conducting waste minimization assessments at- thirty small- to medium-sized businesses in the state of New Jersey. ne of th...

359

Open-Centred Ecosophy Or How to Do Environmentally Interesting Things with Dr Rogers’s Therapeutic Conditions  

Microsoft Academic Search

Being a personal meditation upon environmental ethics, the conflicting claims of anthropocentric and ecocentric approaches to environmental degeneration, the possibility of extending person-centred relationship beyond the world of human beings, the uses of experiential focusing, dissociation, and the possibility that tending our relationship with Earth is an essential part of spiritual practice.

Clive Perraton Mountford

2006-01-01

360

Different environmental conditions, different results: the role of controlled environmental stress on grape quality potential and the way to monitor it  

Microsoft Academic Search

Environmental stress, such as water deficit or limited nitrogen availability, reduces grape yield, but generally promotes grape quality potential for red table wine production. Limited nitrogen uptake limits grape yield but enhances grape quality potential for red table wine production, because it reduces berry size and enhances phenolic compound synthesis. Water deficit stress has one negative effect (reduction of photosynthesis),

C. van Leeuwen; O. Trégoat; X. Choné; J.-P. Gaudillère; D. Pernet

361

The influence of reproductive condition and concurrent environmental factors on torpor and foraging patterns in female big brown bats (Eptesicus fuscus).  

PubMed

Unlike many other mammals, bats in temperate regions employ short bouts of torpor throughout the reproductive period to maintain a positive energy balance. In addition to decreasing energy expenditure during the day, they typically alter foraging patterns as well. It is well known that various environmental conditions influence both torpor and foraging patterns, but studies of these factors often have focussed on one element in isolation thus it is not known how the two behaviours are collectively influencing temperate bats. The objective of our study was to assess how reproductive condition and environmental factors concurrently affect energy balance in female big brown bats (Eptesicus fuscus). We equipped pregnant and lactating bats in southwest Saskatchewan, Canada with temperature-sensitive radio-transmitters. While transmitters were active, skin temperature data were collected and foraging patterns were determined using triangulation. Of the various environmental and physiological parameters used to model torpor characteristics, roost type was the most important factor. Bats roosting in trees used deeper and longer torpor bouts than those roosting in buildings. Lactating bats had a tendency to forage for longer durations than pregnant bats, and often made more foraging trips. When taken together, we found that foraging duration and torpor duration were not directly related during pregnancy, but exhibited an inverse relationship during lactation. This provides support for the hypothesis that there are physiological trade-offs for reproductive bats and suggests that how bats compensate is not entirely predictable based on current environmental conditions. PMID:24973192

Rintoul, Jody L P; Brigham, R Mark

2014-08-01

362

Inactivation of the SecA2 protein export pathway in Listeria monocytogenes promotes cell aggregation, impacts biofilm architecture and induces biofilm formation in environmental condition.  

PubMed

Listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species and as an opportunistic intracellular pathogen. Besides its capacity to grow in a wide range of environmental and stressful conditions, L.?monocytogenes has the ability to adhere to and colonize surfaces. Morphotype variation to elongated cells forming rough colonies has been reported for different clinical and environmental isolates, including biofilms. This cell differentiation is mainly attributed to the reduced secretion of two SecA2-dependent cell-wall hydrolases, CwhA and MurA. SecA2 is a non-essential SecA paralogue forming an alternative translocase with the primary Sec translocon. Following investigation at temperatures relevant to its ecological niches, i.e. infection (37°C) and environmental (20°C) conditions, inactivation of this SecA2-only protein export pathway led, despite reduced adhesion, to the formation of filamentous biofilm with aerial structures. Compared to the wild type strain, inactivation of the SecA2 pathway promoted extensive cell aggregation and sedimentation. At ambient temperature, this effect was combined with the abrogation of cell motility resulting in elongated sedimented cells, which got knotted and entangled together in the course of filamentous-biofilm development. Such a cell differentiation provides a decisive advantage for listerial surface colonization under environmental condition. As further discussed, this morphotypic conversion has strong implication on listerial physiology and is also of potential significance for asymptomatic human/animal carriage. PMID:24102749

Renier, Sandra; Chagnot, Caroline; Deschamps, Julien; Caccia, Nelly; Szlavik, Julie; Joyce, Susan A; Popowska, Magdalena; Hill, Colin; Knøchel, Susanne; Briandet, Romain; Hébraud, Michel; Desvaux, Mickaël

2014-04-01

363

Leaf morphology and phenology of Beech (Fagus sylvatica L.) are linked to environmental conditions depending on the altitudinal origin  

NASA Astrophysics Data System (ADS)

One of the principal responses of temperate climate trees to climate warming, besides migration, will be in-situ adaptation/evolution. For both, germination and growth rates can have a strong impact on survival and long-term recruitment and establishment of a species. Leaf morphology traits, together with phenology, are relevant to the study of inherent capacities of plants to adapt to an ever changing climate, especially in alpine regions, where a rapid warming has been observed in the last decades. The aim of this study was to evaluate the changes in possible adaptive traits (e.g. leaf morphology and phenology) of Beech (Fagus sylvatica L.) and to asses a decisive component of the survival strategy of this important broadly distributed Central European tree species. We collected beech seeds at six sites along two transects of a south- (900, 1000 and 1100-1400 m.a.s.l.) and a north-facing slope (800, 900 and 1100 m.a.s.l.) in 2011 (mast year) near Garmisch-Partenkirchen, Germany. All the seeds were stratified before sowing; 150 seeds were selected from each site and sowed (at the beginning of the spring) in square containers in a greenhouse under the same climatic conditions; seven phenological stages were defined following a modified beech germination key and the phenology of every seed was recorded three times a week. Harvesting took place 38/42 days after sowing and the specific leaf area (SLA), biomass, and leaf morphology (lamina length and width) were recorded for each seedling. Seeds from lower sites of the two transects presented a poorer germination rates (e.g. 30% for the south 900 m.a.s.l. site) and (75% for the north 800 m.a.s.l. site) when compared to seeds originating from higher elevations within the same transect. The highest germination percentages (98 and 85%) were observed in seeds originating from the highest elevations (e.g. 1100-1400 m.a.s.l. of the south site and 1100 m.a.s.l. of the north site, respectively). Although no significant differences in SLA were found among the altitudinal levels in any of the transects, significant differences were found in biomass among the two highest sites of the two transects. The length of the lamina differed significantly between 900 to 1100-1400 m.a.s.l. in the south facing transect, while in the north facing transect the lamina width showed significant differences between the highest and the lower sites. A higher percentage of germination of seeds originating from higher altitudinal sites may points to a developed sensitivity to environmental changes and a rapid and more favorable response. Our results suggest, contrary to what has been reported, (leaf size differentiation among altitudinal sites under natural conditions), that the altitude of origin doesn't have an overriding impact on leaf morphological responses when growing under the same conditions, indicating that leaf morphology and phenology may have an adaptive significance linked to climate.

Capdevielle-Vargas, Renee; Schuster, Christina; Estrella, Nicole; Menzel, Annette

2014-05-01

364

The influence of local effects on thermal sensation under non-uniform environmental conditions--gender differences in thermophysiology, thermal comfort and productivity during convective and radiant cooling.  

PubMed

Applying high temperature cooling concepts, i.e. high temperature cooling (T(supply) is 16-20°C) HVAC systems, in the built environment allows the reduction in the use of (high quality) energy. However, application of high temperature cooling systems can result in whole body and local discomfort of the occupants. Non-uniform thermal conditions, which may occur due to application of high temperature cooling systems, can be responsible for discomfort. Contradictions in literature exist regarding the validity of the often used predicted mean vote (PMV) index for both genders, and the index is not intended for evaluating the discomfort due to non-uniform environmental conditions. In some cases, however, combinations of local and general discomfort factors, for example draught under warm conditions, may not be uncomfortable. The objective of this study was to investigate gender differences in thermophysiology, thermal comfort and productivity in response to thermal non-uniform environmental conditions. Twenty healthy subjects (10 males and 10 females, age 20-29 years) were exposed to two different experimental conditions: a convective cooling situation (CC) and a radiant cooling situation (RC). During the experiments physiological responses, thermal comfort and productivity were measured. The results show that under both experimental conditions the actual mean thermal sensation votes significantly differ from the PMV-index; the subjects are feeling colder than predicted. Furthermore, the females are more uncomfortable and dissatisfied compared to the males. For females, the local sensations and skin temperatures of the extremities have a significant influence on whole body thermal sensation and are therefore important to consider under non-uniform environmental conditions. PMID:22877870

Schellen, L; Loomans, M G L C; de Wit, M H; Olesen, B W; van Marken Lichtenbelt, W D

2012-09-10

365

An Empirical Study of Inter-Organizational Relationship in Condition of Environmental Uncertainty: from View of Information Processing Theory  

Microsoft Academic Search

With changing of environmental uncertainty, inter-organizational coordination and IT support is becoming a trend. Basing on information processing theory (IPT) and empirical studies in 2 large-scale shipbuilding and 4 large-scale automobile companies, this paper explored relationship of environmental uncertainty, inter-organizational coordination, inter-organizational IT support and coordination effectiveness. Managerial implications of the IPT and inter-organizational information systems are also discussed.

Qiuyan Zhong; Gang Qu; Qingfei Min

2007-01-01

366

Effects of pH and temperature on dimerization rate of glycine: Evaluation of favorable environmental conditions for chemical evolution of life  

Microsoft Academic Search

To evaluate favorable environmental conditions for the chemical evolution of life, we studied the effects of pH and temperature on the dimerization rate of glycine (Gly: NH2–CH2–COOH), one of the simplest amino acids. Gly dimerizes to form glycylglycine (GlyGly), and GlyGly further reacts to form diketopiperazine (DKP). Gly solutions with pH ranging from 3.1 to 10.9 were heated for 1–14days

Kasumi Sakata; Norio Kitadai; Tadashi Yokoyama

2010-01-01

367

Relationship between leaf antioxidants and ozone injury in Nicotiana tabacum 'Bel-W3' under environmental conditions in São Paulo, SE - Brazil  

NASA Astrophysics Data System (ADS)

Previous studies have reported that the extent of leaf injury in Nicotiana tabacum "Bel-W3" exposed to environmental conditions in the city of São Paulo is influenced by weather conditions. This influence may occur by means of antioxidant responses. Thus, this study aimed to evaluate whether daily antioxidant responses to environmental variations interfere on the progression of leaf injury on plants of this cultivar during their exposure in a state park of São Paulo and to determine a linear combination of variables, among antioxidants and environmental factors, which mostly explain this visible response. Plants were exposed at the mentioned site for 14 days in four different experiments. During each experiment, three plants were daily sampled to determine the accumulated percentage of leaf area affected by necrosis and antioxidant responses (concentrations of total ascorbic acid (AA) and activity of superoxide dismutase (SOD) and peroxidases (POD)). Ozone concentrations and weather conditions were also daily measured. Pearson correlations and multivariate analyses assessed the relationship between biological and environmental variables. Leaf injury appeared between the 3rd and 6th days of exposure and increased over the exposure periods. The daily concentrations of AA tended to decrease with time of exposure in all experiments, but the activity of SOD and POD oscillated during plant exposure. Positive correlations were observed between AA or SOD and O 3 concentrations, as well as negative correlations between AA and air temperature. The increasing percentage of leaf necrosis across the whole period was explained by decreasing levels of AA 2 days before injury estimation and by higher O 3 concentrations 5 days before ( R2 = 0.36; p < 0.001). The use of N. tabacum Bel-W3 as a bioindicator can be restricted by leaf antioxidant responses to both atmospheric contamination and weather conditions.

Esposito, Marisia P.; Ferreira, Mauricio L.; Sant'Anna, Silvia M. R.; Domingos, Marisa; Souza, Silvia R.

368

ENVIRONMENTAL CONDITIONS, MICROBIAL POPULATIONS, AND THE ROLE OF ATTACHMENT IN OXIDATIVE DISSOLUTION OF PYRITE AT IRON MT. (R826189)  

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

369

Taking the pulse of Colorados Front Range: developing regional indicators of environmental and quality of life condition  

USGS Publications Warehouse

Indicators are routinely used to report the status and trends of human health, economy, educational achievement, and quality of life. Some environmental indicators, such as for water and air quality, are routinely reported and used to inform personal, management, or policy decisions. Other environmental indicators, particularly those that do not relate directly to human well-being, have been harder to define, interpret, or use. These indicators may be just as useful and important in describing the ability to provide ecosystem good and services, or less tangible quality of life measures, but they may be suspect because of the quality of data or even the source of the information.

Baron, Jill S.

2005-01-01

370

FINAL REPORT. INVESTIGATIONS OF TECHNIQUES TO IMPROVE CONTINUOUS AIR MONITORS UNDER CONDITIONS OF HIGH DUST LOADING IN ENVIRONMENTAL SETTINGS  

EPA Science Inventory

The overall objective was to carry out studies to improve the detection of plutonium aerosols by environmental continuous air monitors (ECAMs), particularly in dusty environments. A number of alpha-particle ECAMs are used at DOE sites such as Los Alamos National Laboratory (LANL)...

371

Population dynamics and environmental conditions affecting Trichodesmium spp. (filamentous cyanobacteria) blooms in the south-west lagoon of New Caledonia  

E-print Network

cyanobacteria) blooms in the south-west lagoon of New Caledonia Martine Rodier* and Robert Le Borgne1 * IRD, UR-forming diazotrophic cyanobacteria Trichodesmium spp.20 have drawn attention, not only for their spectacular frequency34 observations of both cyanobacteria and environmental variables over the water column.35

Paris-Sud XI, Université de

372

INVESTIGATION OF TECHNIQUES TO IMPROVE CONTINUOUS AIR MONITORS UNDER CONDITIONS OF HIGH DUST LOADING IN ENVIRONMENTAL SETTINGS  

EPA Science Inventory

The investigation is an in-depth exploration of environmental influences that can cause degradation of the performance (sensitivity, alarm functionality, etc.) of Continuous Air Monitors (CAMs), such as the LANL/Canberra alpha-particle CAM, and a study of techniques to correct fo...

373

SEDIMENT AND PERIPHYTON ASSESSMENT AS INDICATORS OF ENVIRONMENTAL CONDITION IN THE FLORIDA BAY-EVERGLADES TRANSITIONAL ZONE  

EPA Science Inventory

Florida Bay and its watershed are currently the focus of numerous investigations designed to assess the extent and cause of deterioration in environmental quality observed during recent years. Periphyton and sediment bioassessment were used in a multiyear study to compare the rel...

374

Interacting effects of translocation, artificial propagation, and environmental conditions on the marine survival of Chinook salmon from the Columbia River, Washington, U.S.A.  

PubMed

Captive rearing and translocation are often used concurrently for species conservation, yet the effects of these practices can interact and lead to unintended outcomes that may undermine species' recovery efforts. Controls in translocation or artificial-propagation programs are uncommon; thus, there have been few studies on the interacting effects of these actions and environmental conditions on survival. The Columbia River basin, which drains 668,000 km(2) of the western United States and Canada, has an extensive network of hydroelectric and other dams, which impede and slow migration of anadromous Pacific salmon (Oncorhynchus spp.) and can increase mortality rates. To mitigate for hydrosystem-induced mortality during juvenile downriver migration, tens of millions of hatchery fish are released each year and a subset of wild- and hatchery-origin juveniles are translocated downstream beyond the hydropower system. We considered how the results of these practices interact with marine environmental conditions to affect the marine survival of Chinook salmon (O. tshawytscha). We analyzed data from more than 1 million individually tagged fish from 1998 through 2006 to evaluate the probability of an individual fish returning as an adult relative to its rearing (hatchery vs. wild) and translocation histories (translocated vs. in-river migrating fish that traveled downriver through the hydropower system) and a suite of environmental variables. Except during select periods of very low river flow, marine survival of wild translocated fish was approximately two-thirds less than survival of wild in-river migrating fish. For hatchery fish, however, survival was roughly two times higher for translocated fish than for in-river migrants. Competition and predator aggregation negatively affected marine survival, and the magnitude of survival depended on rearing and translocation histories and biological and physical conditions encountered during their first few weeks of residence in the ocean. Our results highlight the importance of considering the interacting effects of translocation, artificial propagation, and environmental variables on the long-term viability of species. PMID:22808952

Holsman, Kirstin K; Scheuerell, Mark D; Buhle, Eric; Emmett, Robert

2012-10-01

375

Durability and Design Issues of Thermal/environmental Barrier Coatings on Sic/sic Ceramic Matrix Composites Under 1650 C Test Conditions  

NASA Technical Reports Server (NTRS)

Ceramic thermal/environmental barrier coatings for SiC-based ceramics will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. However, the coating durability remains a major concern with the ever-increasing temperature requirements. Currently, advanced T/EBC systems, which typically include a high temperature capable zirconia- (or hahia-) based oxide top coat (thermal barrier) on a less temperature capable mullite/barium-strontium-aluminosilicate (BSAS)/Si inner coat (environmental barrier), are being developed and tested for higher temperature capability Sic combustor applications. In this paper, durability of several thermal/environmental barrier coating systems on SiC/SiC ceramic matrix composites was investigated under laser simulated engine thermal gradient cyclic, and 1650 C (3000 F) test conditions. The coating cracking and delamination processes were monitored and evaluated. The effects of temperature gradients and coating configurations on the ceramic coating crack initiation and propagation were analyzed using finite element analysis (FEA) models based on the observed failure mechanisms, in conjunction with mechanical testing results. The environmental effects on the coating durability will be discussed. The coating design approach will also be presented.

Zhu, Dong-Ming; Choi, Sung R.; Ghosn, Louis J.; Miller, Robert A.

2004-01-01

376

Senilia senilis (Linnaeus, 1758), a biogenic archive of environmental conditions on the Banc d'Arguin (Mauritania)  

NASA Astrophysics Data System (ADS)

Environmental archives are useful tools for describing past and current climate variations and they provide an opportunity to assess the anthropogenic contribution in coastal ecological changes. Along the West African coast, few studies have focused on such archives in coastal ecosystems. The bloody cockle Senilia senilis, an intertidal bivalve mollusk species, is widely distributed from Western Sahara to Angola, and has been harvested by humans over thousands of years. Therefore, this species appears to be a good candidate for assessing past variations of key environmental parameters such as temperature, primary production, and Saharan dust advection within West African coastal ecosystems. In the present paper, we focused (i) on the identification of growth rhythms of S. senilis shells in Mauritania (Banc d'Arguin), and (ii) on the potential of these shells as (paleo-)environmental archives. The method we used combined environmental survey, sclerochronology, and geochemical analyses of aragonite samples. We showed that microgrowth line formation was controlled by a tidal forcing, leading to the formation of two lines per lunar day. Brightness and thickness of these microgrowth lines progressively decreased from spring to neap tides (fortnightly cycle). Lunar daily growth rates displayed strong seasonal variations, with highest values (> 300 ?m per lunar day) recorded in summer. The oxygen isotope composition of S. senilis shells (?18Oaragonite) accurately tracked seawater temperature seasonal variations, with a precision of 0.8 °C. Finally, we discussed the opportunity to use Ba:Ca ratio in shells as a proxy for primary production or for Saharan dust transport. We also hypothesized that either Canary Currentvariations or, more probably, massive aerosol transfers from Sahara to the Atlantic Ocean could control uranium availability in coastal waters and explain the occurrence of U:Ca peaks within S. senilis shells.

Lavaud, Romain; Thébault, Julien; Lorrain, Anne; van der Geest, Matthijs; Chauvaud, Laurent

2013-02-01

377

Oceanic and local environmental conditions as forcing mechanisms of the glass eel recruitment to the southernmost European estuary  

NASA Astrophysics Data System (ADS)

The main oceanic and local environmental traits forcing the glass eel Anguilla anguilla (L., 1758) recruitment to the southernmost European estuary, the Guadalquivir (SW Spain), were studied during nine successive migration seasons (June 1997-December 2006) using a fishery-independent experimental survey at three sampling sites in the estuary. A clear seasonal pattern was observed: density was highest between late autumn and spring with two migration peaks, and lowest during summer. Short-term (inter-month) changes in glass eel density were partially driven by local environmental variables, such as estuarine turbidity, local rainfall and water temperature. Long-term (inter-annual) changes were positively correlated with oceanic factors related to recruitment success (NAO index and primary production at the spawning area) as well as local environmental factors (westerly and southerly wind mixing indices and rainfall). Spatial changes in glass eel density within the estuary depended on tidal and light situations although maximum densities were mainly observed at diurnal and/or nocturnal flood tides. Although the decrease in the abundance of European glass eels has been widely known since the 1980s, during this study there was no evidence of a declining trend, probably because of an insufficiently long time series.

Arribas, Carmen; Fernández-Delgado, Carlos; Oliva-Paterna, Francisco J.; Drake, Pilar

2012-07-01

378

Visualising reacting single atoms under controlled conditions: Advances in atomic resolution in situ Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM)  

NASA Astrophysics Data System (ADS)

Advances in atomic resolution Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM) for probing gas-solid catalyst reactions in situ at the atomic level under controlled reaction conditions of gas environment and temperature are described. The recent development of the ESTEM extends the capability of the ETEM by providing the direct visualisation of single atoms and the atomic structure of selected solid state heterogeneous catalysts in their working states in real-time. Atomic resolution E(S)TEM provides a deeper understanding of the dynamic atomic processes at the surface of solids and their mechanisms of operation. The benefits of atomic resolution-E(S)TEM to science and technology include new knowledge leading to improved technological processes with substantial economic benefits, improved healthcare, reductions in energy needs and the management of environmental waste generation.

Boyes, Edward D.; Gai, Pratibha L.

2014-02-01

379

Wetland environmental conditions associated with the risk of avian cholera outbreaks and the abundance of Pasteurella multocida  

USGS Publications Warehouse

Avian cholera is a significant infectious disease affecting waterfowl across North America and occurs worldwide among various avian species. Despite the importance of this disease, little is known about the factors that cause avian cholera outbreaks and what management strategies might be used to reduce disease mortality. Previous studies indicated that wetland water conditions may affect survival and transmission of Pasteurella multocida, the agent that causes avian cholera. These studies hypothesized that water conditions affect the likelihood that avian cholera outbreaks will occur in specific wetlands. To test these predictions, we collected data from avian cholera outbreak and non-outbreak (control) wetlands throughout North America (wintera??spring 1995a??1996 to 1998a??1999) to evaluate whether water conditions were associated with outbreaks. Conditional logistic regression analysis on paired outbreak and non-outbreak wetlands indicated no significant association between water conditions and the risk of avian cholera outbreaks. For wetlands where avian cholera outbreaks occurred, linear regression showed that increased eutrophic nutrient concentrations (Potassium [K], nitrate [NO3], phosphorus [P], and phosphate [PO3]) were positively related to the abundance of P. multocida recovered from water and sediment samples. Wetland protein concentration and an El Ni??o event were also associated with P. multocida abundance. Our results indicate that wetland water conditions are not strongly associated with the risk of avian cholera outbreaks; however, some variables may play a role in the abundance of P. multocida bacteria and might be important in reducing the severity of avian cholera outbreaks.

Blanchong, J.A.; Samuel, Michael D.; Goldberg, Diana R.; Shadduck, Daniel J.; Creekmore, L.H.

2006-01-01

380

Responses of CO(2), N(2)O and CH(4) fluxes between atmosphere and forest soil to changes in multiple environmental conditions.  

PubMed

To investigate the effects of multiple environmental conditions on greenhouse gas (CO2 , N2 O, CH4 ) fluxes, we transferred three soil monoliths from Masson pine forest (PF) or coniferous and broadleaved mixed forest (MF) at Jigongshan to corresponding forest type at Dinghushan. Greenhouse gas fluxes at the in situ (Jigongshan), transported and ambient (Dinghushan) soil monoliths were measured using static chambers. When the transported soil monoliths experienced the external environmental factors (temperature, precipitation and nitrogen deposition) at Dinghushan, its annual soil CO2 emissions were 54% in PF and 60% in MF higher than those from the respective in situ treatment. Annual soil N2 O emissions were 45% in PF and 44% in MF higher than those from the respective in situ treatment. There were no significant differences in annual soil CO2 or N2 O emissions between the transported and ambient treatments. However, annual CH4 uptake by the transported soil monoliths in PF or MF was not significantly different from that at the respective in situ treatment, and was significantly lower than that at the respective ambient treatment. Therefore, external environmental factors were the major drivers of soil CO2 and N2 O emissions, while soil was the dominant controller of soil CH4 uptake. We further tested the results by developing simple empirical models using the observed fluxes of CO2 and N2 O from the in situ treatment and found that the empirical models can explain about 90% for CO2 and 40% for N2 O of the observed variations at the transported treatment. Results from this study suggest that the different responses of soil CO2 , N2 O, CH4 fluxes to changes in multiple environmental conditions need to be considered in global change study. PMID:23868392

Yan, Junhua; Zhang, Wei; Wang, Keya; Qin, Fen; Wang, Wantong; Dai, Huitang; Li, Peixue

2014-01-01

381

Conclusive quantum steering with superconducting transition-edge sensors  

NASA Astrophysics Data System (ADS)

Quantum steering allows two parties to verify shared entanglement even if one measurement device is untrusted. A conclusive demonstration of steering through the violation of a steering inequality is of considerable fundamental interest and opens up applications in quantum communication. To date, all experimental tests with single-photon states have relied on post selection, allowing untrusted devices to cheat by hiding unfavourable events in losses. Here we close this 'detection loophole' by combining a highly efficient source of entangled photon pairs with superconducting transition-edge sensors. We achieve an unprecedented ~62% conditional detection efficiency of entangled photons and violate a steering inequality with the minimal number of measurement settings by 48 s.d.s. Our results provide a clear path to practical applications of steering and to a photonic loophole-free Bell test.

Smith, Devin H.; Gillett, Geoff; de Almeida, Marcelo P.; Branciard, Cyril; Fedrizzi, Alessandro; Weinhold, Till J.; Lita, Adriana; Calkins, Brice; Gerrits, Thomas; Wiseman, Howard M.; Nam, Sae Woo; White, Andrew G.

2012-01-01

382

Conclusive quantum steering with superconducting transition edge sensors  

NASA Astrophysics Data System (ADS)

Quantum steering allows two parties to verify shared entanglement even if one measurement device is untrusted. A conclusive demonstration of steering through the violation of a steering inequality is of considerable fundamental interest and opens up applications in quantum communication. To date all experimental tests with single photon states have relied on post-selection, allowing untrusted devices to cheat by hiding unfavorable events in losses. Here we close this ``detection loophole'' by combining a highly efficient source of entangled photon pairs with superconducting transition edge sensors. We achieve an unprecedented ˜62% conditional detection efficiency of entangled photons and violate a steering inequality with the minimal number of measurement settings by 48 standard deviations. Our results provide a clear path to practical applications of steering and to a photonic loophole-free Bell test.

de Almeida, Marcelo P.; Smith, Devin H.; Gillett, Geo; Branciard, Cyril; Fedrizzi, Alessandro; Weinhold, Till J.; Lita, Adriana; Calkins, Brice; Gertis, Thomas; Nam, Sae Woo; White, Andrew G.

2012-02-01

383

Reconfigurable environmentally adaptive computing  

NASA Technical Reports Server (NTRS)

Described are methods and apparatus, including computer program products, for reconfigurable environmentally adaptive computing technology. An environmental signal representative of an external environmental condition is received. A processing configuration is automatically selected, based on the environmental signal, from a plurality of processing configurations. A reconfigurable processing element is reconfigured to operate according to the selected processing configuration. In some examples, the environmental condition is detected and the environmental signal is generated based on the detected condition.

Coxe, Robin L. (Inventor); Galica, Gary E. (Inventor)

2008-01-01

384

Achieving high lipid productivity of a thermotolerant microalga Desmodesmus sp. F2 by optimizing environmental factors and nutrient conditions.  

PubMed

The optimal conditions for cultivating the thermotolerant lipid-rich microalga Desmodesmus sp. F2 to achieve maximal lipid productivity were determined in this study. The conditions were light intensity, 700?mol/m(2)s; temperature, 35°C; cultivation nitrogen source, nitrate; initial nitrogen level, 6.6mM nitrogen. Carbon dioxide (2.5%, 0.2 vvm) was pumped into the cultures continuously. In the pre-optimized conditions, the maximal lipid productivity of this microalga was 113mg/L/d, which was raised to 263mg/L/d in the optimized conditions. This level of lipid productivity of microalgae is the highest ever reported in the literature. Fatty acid composition of the lipid produced by Desmodesmus sp. F2 in the optimal conditions was determined, in which C16 and C18 species accounted for 95% of the fatty acids. Saturated, monounsaturated and polyunsaturated fatty acids accounted for 38.9%, 33.1% and 22.6%, respectively. Based on the analysis, this lipid quality makes it a good feedstock for biodiesel production. PMID:24491294

Ho, Shih-Hsin; Chang, Jo-Shu; Lai, Yen-Ying; Chen, Ching-Nen Nathan

2014-03-01

385

Effects of nutritional and environmental conditions on planktonic growth and biofilm formation of Citrobacter werkmanii BF-6.  

PubMed

Citrobacter sp. is a cause of significant opportunistic nosocomial infection and is frequently found in human and animal feces, soil, and sewage water, and even in industrial waste or putrefaction. Biofilm formation is an important virulence trait of Citrobacter sp. pathogens but the process and characteristics of this formation are unclear. Therefore, we employed in vitro assays to study the nutritional and environmental parameters that might influence biofilm formation of C. werkmanii BF-6 using 96-well microtiter plates. In addition, we detected the relative transcript levels of biofilm formation genes by RT-PCR. Our results indicated that the capacity of C. werkmanii BF-6 to form biofilms was affected by culture temperature, media, time, pH, and the osmotic agents glucose, sucrose, NaCl, and KCl. Confocal laser scanning microscopy results illustrated that the structure of biofilms and extracellular polysaccharide was influenced by 100 mM NaCl or 100 mM KCl. In addition, nine biofilm formation genes (bsmA, bssR, bssS, csgD, csgE, csgF, mrkA, mrkB, and mrkE) were found to contribute to planktonic and biofilm growth. Our data suggest that biofilm formation by C. werkmanii BF-6 is affected by nutritional and environmental factors, which could pave the way to the prevention and elimination of biofilm formation using proper strategies. PMID:24018970

Zhou, Gang; Li, Long-jie; Shi, Qing-shan; Ouyang, You-sheng; Chen, Yi-ben; Hu, Wen-feng

2013-12-01

386

Prediction Computer Program for Whole Body Temperatures and its Application under Various Working Level and Thermal Environmental Condition Combinations  

Microsoft Academic Search

We introduced a computer program developed for the numerical analysis of thermal conditions of all segments and blood circulatory systems in the human body to precisely evaluate human thermal physiological responses. In this program, a cylindrical model consisting of internal multi-layers is adapted for the segment of the human body. For the multi-layered concentric cylindrical model we adopted a new

Shintaro YOKOYAMA; Michiyoshi TAO; Naoto KAKUTA

2007-01-01

387

Lake Diatoms as Indicators of Land Use Effects, Changing Environmental Conditions, and the Effectiveness of Management Practices  

EPA Science Inventory

Lakes continue to face escalating pressures associated with land cover change and growing human populations. The U.S. EPA National Lakes Assessment, which sampled more than 1000 lakes in a probabilistic survey, was the first large scale effort to characterize the condition of lak...

388

Glutamate-associated plasticity in the ventral tegmental area is necessary for conditioning environmental stimuli with morphine  

Microsoft Academic Search

We sought to determine if plasticity in the ventral tegmental area (VTA) of the midbrain is involved in learning to associate morphine exposure with a specific environment. For this, we tested whether activation of glutamate receptors and protein kinase A is needed for the acquisition and expression of a morphine-conditioned place preference (CPP). Rats received bilateral microinjections of either the

G. C. Harris; M. Wimmer; R. Byrne; G. Aston-Jones

2004-01-01

389

Response of the Toxic Dinoflagellate Karenia brevis to Current and Projected Environmental Conditions: Salinity and Global Climate Change  

E-print Network

. When grown at salinities of 35 and 27, but otherwise identical conditions, total brevetoxin cellular concentration varied between 0 to 18.5 pg cell-1 and brevenal varied between 0 and 1 pg cell-1. In response to hypoosmotic stress brevetoxin production...

Errera, Reagan Michelle

2013-05-03

390

Analysis of flowering, stigmas yield and qualitative traits of saffron ( Crocus sativus L.) as affected by environmental conditions  

Microsoft Academic Search

Saffron is well known for its use as a condiment spice, as a dye and traditional medicine. Saffron is experiencing an increasing interest mainly due to its peculiar and manifold properties of the metabolic pool of its stigmas, mainly crocetin esters and picrocrocin. This species is cultivated in environments with very different climatic conditions and with very different corm rates

F. Gresta; G. Avola; G. M. Lombardo; L. Siracusa; G. Ruberto

2009-01-01

391

Effect of environmental conditions on various enzyme activities and triacylglycerol contents in cultures of the freshwater diatom, Asterionella formosa (Bacillariophyceae).  

PubMed

A detailed analysis of triacylglycerols (TAGs) contents, fatty acid patterns and key enzyme activities in the freshwater diatom Asterionella formosa was performed under various conditions, including nitrate, iron and silicon limitation (stress conditions), or bicarbonate and phytohormones supplementation (stimulation conditions). Of all the conditions tested, the addition of bicarbonate produced the greatest increase (5-fold) in TAGs contents compared to the control while the biomass increased. The addition of phytohormones also allowed a significant increase in TAGs of about 3-fold while the biomass increased. Silicon, unlike iron and nitrate limitation, also triggered a significant increase in TAGs contents of 3.5-fold but negatively affected the biomass. Analysis of fatty acid profiles showed that the mono-unsaturated C16:1 fatty acid was the most abundant in A. formosa, followed by C16:0, C14:0 and eicosapentaenoic acid (EPA; C20:5 n-3). EPA levels were found to increase under nitrate and iron limitation. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphoribulokinase (PRK), phosphofructokinase (PFK), glucose-6-phosphate dehydrogenase (G6PDH) and malate dehydrogenase (MDH) activities differed with growth conditions. Most enzymes were up-regulated in stimulated cells while in the case of stressed cells, the pattern of activities was more variable. Detailed analysis of all enzyme activities showed that the most important enzyme among those tested was GAPDH which could be a good candidate for genetic engineering of high lipid-producing algae. This study provides a better understanding of key enzymes and biochemical pathways involved in lipid accumulation processes in diatoms. PMID:24355202

Mekhalfi, Malika; Amara, Sawsan; Robert, Sylvie; Carrière, Frédéric; Gontero, Brigitte

2014-06-01

392

Modeling the effect of adverse environmental conditions and clothing on temperature rise in a human body exposed to radio frequency electromagnetic fields.  

PubMed

This study considers the computationally determined thermal profile of a fully clothed, finely discretized, heterogeneous human body model, subject to the maximum allowable reference level for a 1-GHz radio frequency electromagnetic field for a worker, and also subject to adverse environmental conditions, including high humidity and high ambient temperature. An initial observation is that while electromagnetic fields at the occupational safety limit will contribute an additional thermal load to the tissues, and subsequently, cause an elevated temperature, the magnitude of this effect is far outweighed by that due to the conditions including the ambient temperature, relative humidity, and the type of clothing worn. It is envisaged that the computational modeling approach outlined in this paper will be suitably modified in future studies to evaluate the thermal response of a body at elevated metabolic rates, and for different body shapes and sizes including children and pregnant women. PMID:25314694

Moore, Stephen M; McIntosh, Robert L; Iskra, Steve; Wood, Andrew W

2015-02-01

393

Spatial and temporal changes of coastal demersal assemblages in the Gulf of Cadiz (SW Spain) in relation to environmental conditions  

NASA Astrophysics Data System (ADS)

Changes in space and time in "global values" (numerical abundance, biomass, diversity ( H', Shannon-Wiener), number of species ( S)) and in the structure of demersal assemblages were studied in a coastal fringe of the Gulf of Cadiz between the Guadiana and the Guadalquivir rivers. Further, the seasonal patterns in length-frequency histograms and the percentage of juveniles of 10 selected species were calculated based on literature data on length at first maturity ( Lm). Twenty-four successive monthly demersal fishery surveys were conducted between March 2002 and February 2004 at eight fixed stations between 5 and 30 m depth, from which 175 hauls were analysed. Fifty-seven taxa belonging to four orders of fish, cephalopods and crustaceans were selected for analysis. Environmental characterisation included the variables depth, sediment type, bottom temperature (BT), total bottom chlorophyll (BChl), and bottom suspended solids (BSS). Relationships among environmental variables as well as their spatial and temporal changes were explored through Spearman rank correlation ( Rs) and Kruskall-Wallis tests. Their relation to global values was assessed through Rs. Differences in global values with respect to space (station) and time (year and season) was assessed through ANOVA techniques via GLM. Spatial and temporal differences in demersal structure were analysed through different multivariate routines from PRIMER including between-matrix correlation analysis (RELATE), analysis of similarities (ANOSIM), species contributions to similarity/dissimilarity (SIMPER), non-metric multidimensional scaling (MDS) and group-average cluster analysis. The degree of match between species-similarity matrices (Bray-Curtis, root-root transformed) and environmental similarity matrices (Euclidean distance) was assessed through the BIO-ENV approach also from PRIMER. Individual Rs correlations between selected species and environmental variables also were performed at each station. A strong spatial gradient related to depth, sediment type, and BT (all related to the distance from the Guadalquivir River mouth) was responsible for most of the explained variability in global values and demersal species structure. The shallowest stations, also close to the Guadalquivir River mouth, showed higher numerical abundance and biomass values, and lower H' and S values. Typical or abundant species from those stations included fishes from the families Sparidae (particularly Diplodus bellottii), Haemulidae, Soleidae or the stomatopod Squilla mantis. Some small pelagics like Engraulis encrasicolus were also important at those stations, although were excluded from the analyses to reduce bias. Northwestern deeper stations were defined by higher relative densities of cephalopods and several pleuronectiform fish. Significant seasonal differences in the abundance of several species also were observed at most stations, mainly between summer and winter. Species like Merluccius merluccius were particularly abundant in winter, whereas Arnoglossus laterna was more abundant in summer. Length-frequency analyses showed that changes in abundance were, in many cases, related to the massive appearance of small individuals in the area. Juvenile stages were observed either exclusively or temporally for many of the analysed taxa, revealing the high importance of this zone as a nursery.

Catalán, I. A.; Jiménez, M. T.; Alconchel, J. I.; Prieto, L.; Muñoz, J. L.

2006-06-01

394

The Effect of Natural Tree Gum and Environmental Condition on the Degradation of a Typical Automotive Clear Coat  

Microsoft Academic Search

In this work the effects of natural gum and its simulated compound (Arabic gum) on an acrylic based clear coat applied on\\u000a different basecoats were studied. The experiments were conducted at various aging processes to simulate the real outdoor conditions\\u000a by the aid of different analytical techniques including optical microscopy, scanning electron microscopy, ATR-FTIR spectroscopy,\\u000a DMTA and micro hardness measurements,

B. Ramezanzadeh; M. Mohseni; H. Yari

2010-01-01

395

Environmental conditions affect sex expression in monoecious, but not in male and female plants of Urtica dioica  

Microsoft Academic Search

Urtica dioica is a sub-dioecious plant species, i.e. males and females coexist with monoecious individuals. Under standard conditions, seed sex ratio (SSR, fraction of males) was found to vary significantly among seed samples collected from female plants originating from the same population (0.05–0.76). As a first step, we investigated the extent to which SSR and sex expression of male, female,

Grit A. Glawe; Tom J. de Jong

2005-01-01

396

Effect of preharvest anti-fungal compounds on Aspergillus steynii and A. carbonarius under fluctuating and extreme environmental conditions.  

PubMed

Ochratoxin A (OTA) has been found in pre-harvest and freshly harvested wheat. Spanish climatic conditions point to Aspergillus species as probably responsible for this OTA. In this study the effectiveness of 5 non-specific antifungal chemicals used on wheat fields (25.9% tebuconazole+60.0% N,N-capramide dimethyl; 12.70% tebuconazole+12.7% prothioconazole+59.5% N,N-amide dimethyldecane; 12.5% epoxiconazole; 12.5% tetraconazole; and 70% thiophanate methyl) and an extract from Equisetum arvense were investigated in vitro on wheat by recording growth (colony size, fungal growth and DNA concentration) and OTA production of two ochratoxigenic isolates of Aspergillus carbonarius and three of A. steynii, simulating current and extreme climatic conditions. Inoculated wheat was incubated under two alternating temperature cycles (20/30°C and 25/35°C) with photoperiod (14/10h lightness/darkness), and two moisture levels (40 and 25%). The Aspergillus species tested seemed to be able to persist in predicted future climatic conditions, in particular, A. steynii, a high OTA producer. Azoles were effective in controlling the growth of A. carbonarius and A. steynii, and this effectiveness may not be compromised by the increase in temperature and decrease of humidity. However, azoles are not useful for the prevention of OTA accumulation, which could be only reduced in A. carbonarius under non-extreme conditions. Although some adjustment will probably be required, further studies should be conducted in the field, since the antifungals used in this study are applied at flowering and not directly on the grain. Moreover, timing of antifungal application may need to be optimized. Finally, Equisetum extract showed promising results as an antifungal, however further work to adjust the applied concentrations is required. PMID:22947301

García-Cela, E; Gil-Serna, J; Marín, S; Acevedo, H; Patiño, B; Ramos, A J

2012-10-01

397

Plant community, primary productivity, and environmental conditions following wetland re-establishment in the Sacramento-San Joaquin Delta, California  

Microsoft Academic Search

Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable\\u000a for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland\\u000a hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in\\u000a two re-established

Robin L. Miller; Roger Fujii

2010-01-01

398

Impact of environmental conditions on the chemical surface properties of Cu(In,Ga)(S,Se){sub 2} thin-film solar cell absorbers  

SciTech Connect

Environmentally driven aging effects play a crucial role in thin-film solar cells based on Cu(In,Ga)(S,Se){sub 2}, both for long-term stability and short air exposure during production. For a better understanding of such effects, Cu(In,Ga)(S,Se){sub 2} absorber surfaces were investigated by x-ray photoelectron and Auger electron spectroscopy after exposure to different environmental conditions. Identical absorbers were stored in a nitrogen atmosphere, in damp heat, and under ambient conditions for up to 14 days. We find varying degrees of diffusion of sulfur, copper, and sodium towards the surface, with potential impact on the electronic surface structure (band gap) and the properties of the interface to a buffer layer in a solar cell device. Furthermore, we observe an oxidation (in decreasing order) of indium, copper, and selenium (but no oxidation of sulfur). And finally, varying amounts of carbon- and oxygen-containing adsorbates are found. In particular, the findings suggest that, for ambient air exposure, sodium carbonate is formed at the surface.

Hauschild, D., E-mail: dirk.hauschild@physik.uni-wuerzburg.de, E-mail: l.weinhardt@kit.edu; Meyer, F. [Experimental Physics VII, University of Würzburg, Am Hubland, 97074 Würzburg (Germany); Pohlner, S.; Lechner, R.; Dietmüller, R.; Palm, J. [AVANCIS GmbH and Co. KG, Otto-Hahn-Ring 6, 81739 Munich (Germany); Heske, C. [Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Parkway, Las Vegas, Nevada 89154-4003 (United States); Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 18/20, 76128 Karlsruhe (Germany); Weinhardt, L., E-mail: dirk.hauschild@physik.uni-wuerzburg.de, E-mail: l.weinhardt@kit.edu [Institute for Photon Science and Synchrotron Radiation, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); ANKA Synchrotron Radiation Facility, Karlsruhe Institute of Technology (KIT), Hermann-v.-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Department of Chemistry, University of Nevada, Las Vegas (UNLV), 4505 Maryland Parkway, Las Vegas, Nevada 89154-4003 (United States); Reinert, F. [Experimental Physics VII, University of Würzburg, Am Hubland, 97074 Würzburg (Germany); Karlsruhe Institute of Technology (KIT), Gemeinschaftslabor für Nanoanalytik, 76021 Karlsruhe (Germany)

2014-05-14

399

Gas chromatography for in situ analysis of a cometary nucleus V. Study of capillary columns' robustness submitted to long-term reduced environmental pressure conditions.  

PubMed

With the European Space Agency's Rosetta space mission to comet 67P/Churyumov-Gerasimenko, a gas chromatograph, part of the COmetary Sampling And Composition (COSAC) experiment, travelled for about 10 years in the interplanetary medium before operating at the surface of the cometary nucleus in November 2014. During its journey in space, the instrument was exposed to the constraining conditions of the interplanetary medium, including reduced environmental pressures. In order to estimate the potential influence of this severe condition on the chromatographic capillary columns, their stationary phase and the subsequent separation capability, a set of flight spare columns were kept under reduced environmental pressure in the laboratory for the same duration as the probe sent to the comet. The columns' analytical performances were evaluated recently and compared to the original ones obtained just before the launch of the Rosetta probe. The results presented here show that the chromatographic performances of the spare chromatographic columns were not altered in time. From this result, it can be expected that the flight instrument will perform nominally for the analysis of the first cometary nucleus sample to be collected ever, and that the preparation of the interpretation of the data to be taken at the cometary surface nucleus can be done through calibration of these spare columns, and other spare components of the instrument. PMID:25441355

Szopa, C; Sternberg, R; Coscia, D; Goesmann, F; Gomes, R; Legrand, S; Jerome, M; Meierhenrich, U J; Raulin, F

2014-11-14

400

Unraveling associations between cyanobacteria blooms and in-lake environmental conditions in Missisquoi Bay, Lake Champlain, USA, using a modified self-organizing map.  

PubMed

Exploratory data analysis on physical, chemical, and biological data from sediments and water in Lake Champlain reveals a strong relationship between cyanobacteria, sediment anoxia, and the ratio of dissolved nitrogen to soluble reactive phosphorus. Physical, chemical, and biological parameters of lake sediment and water were measured between 2007 and 2009. Cluster analysis using a self-organizing artificial neural network, expert opinion, and discriminant analysis separated the data set into no-bloom and bloom groups. Clustering was based on similarities in water and sediment chemistry and non-cyanobacteria phytoplankton abundance. Our analysis focused on the contribution of individual parameters to discriminate between no-bloom and bloom groupings. Application to a second, more spatially diverse data set, revealed similar no-bloom and bloom discrimination, yet a few samples possess all the physicochemical characteristics of a bloom without the high cyanobacteria cell counts, suggesting that while specific environmental conditions can support a bloom, another environmental trigger may be required to initiate the bloom. Results highlight the conditions coincident with cyanobacteria blooms in Missisquoi Bay of Lake Champlain and indicate additional data are needed to identify possible ecological contributors to bloom initiation. PMID:24251635

Pearce, Andrea R; Rizzo, Donna M; Watzin, Mary C; Druschel, Gregory K

2013-12-17

401

Potential effects of environmental conditions on the efficiency of the antifungal tebuconazole controlling Fusarium verticillioides and Fusarium proliferatum growth rate and fumonisin biosynthesis.  

PubMed

Fusarium verticillioides and Fusarium proliferatum are important phytopathogens which contaminate cereals in the Mediterranean climatic region with fumonisins. In this study we examined the interaction between the fungicide efficacy of tebuconazole and water potential (?w) (-0.7-7.0MPa)×temperature (20-35°C) on growth and FUM1 gene expression by real time RT-PCR (an indicator of fumonisin biosynthesis) in strains of both Fusarium species. Concentrations of tebuconazole required to reduce growth by 50 and 90% (ED50 and ED90 values) were determined. Growth of strains of both species was largely reduced by tebuconazole, with similar efficacy profiles in the interacting water potential×temperature conditions. In contrast, FUM1 expression was not generally reduced by tebuconazole. Moreover, sub-lethal doses in combination with mild water stress and temperatures less than 35°C significantly induced FUM1 expression with slight differences in both species. These results suggest that the efficacy of antifungal compounds to reduce mycotoxin risk would be more effective if consideration is given to both growth rate and toxin biosynthesis in relation to interacting enviro