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1

Environmental Conditions Environmental Conditions  

E-print Network

in habitat conditions. Stream flows, water temperatures, substrate characteristics and other combined watershed processes and human activities that influence flow, water quality, upland and riparian conditions feet in one mile The watershed includes approximately 760 miles of perennial streams and 1,440 miles

2

Environmental effects of dredging. Evaluation of sediment genotoxicity. Workshop summary and conclusions. Technical notes  

SciTech Connect

This Technical Note summarizes the proceedings of a workshop that was held March 6-8,1990, at the Environmental Laboratory, US Army Engineer Waterways Experiment Station. The purpose of the workshop was to gain guidance from recognized authorities for the development of sediment bioassays of genotoxicity, that is, mutagenicity, carcinogenicity, immunotoxicity, teratogenicity, and histopathologic potential. The conclusions of the workshop are being used to identify existing genotoxicity bioassays that show promise for application in evaluating sediments, to recommend modifications for testing sediments, and to help direct subsequent research and development of bioassays of genotoxicity by the US Army Corps of Engineers.

NONE

1990-10-01

3

Annual environmental conditions report, 1995 (Illinois Environmental Protection Agency)  

SciTech Connect

The first annual environmental conditions report has been prepared by the IEPA to help focus attention on environmental results. The report is designed to present information for 23 environmental goals and 26 environmental indicators.

NONE

1996-07-01

4

Summary Conclusions on Computational Experience and the Explanatory Value of Condition Measures for Linear Optimization  

Microsoft Academic Search

The modern theory of condition measures for convex opti- mization problems was initially developed for convex problems in the following conic format , and several aspects of the theory have now been extended to handle non-conic formats as well. In this theory, the (Renegar-) condition measure for has been shown to be connected to bounds on a wide variety of

Robert M. Freund

5

Cross-taxon congruence and environmental conditions  

PubMed Central

Background Diversity patterns of different taxa typically covary in space, a phenomenon called cross-taxon congruence. This pattern has been explained by the effect of one taxon diversity on taxon diversity, shared biogeographic histories of different taxa, and/or common responses to environmental conditions. A meta-analysis of the association between environment and diversity patterns found that in 83 out of 85 studies, more than 60% of the spatial variability in species richness was related to variables representing energy, water or their interaction. The role of the environment determining taxa diversity patterns leads us to hypothesize that this would explain the observed cross-taxon congruence. However, recent analyses reported the persistence of cross-taxon congruence when environmental effect was statistically removed. Here we evaluate this hypothesis, analyzing the cross-taxon congruence between birds and mammals in the Brazilian Cerrado, and assess the environmental role on the spatial covariation in diversity patterns. Results We found a positive association between avian and mammal richness and a positive latitudinal trend for both groups in the Brazilian Cerrado. Regression analyses indicated an effect of latitude, PET, and mean temperature over both biological groups. In addition, we show that NDVI was only associated with avian diversity; while the annual relative humidity, was only correlated with mammal diversity. We determined the environmental effects on diversity in a path analysis that accounted for 73% and 76% of the spatial variation in avian and mammal richness. However, an association between avian and mammal diversity remains significant. Indeed, the importance of this link between bird and mammal diversity was also supported by a significant association between birds and mammal spatial autoregressive model residuals. Conclusion Our study corroborates the main role of environmental conditions on diversity patterns, but suggests that other important mechanisms, which have not been properly evaluated, are involved in the observed cross-taxon congruence. The approaches introduced here indicate that the prevalence of a significant association among taxa, after considering the environmental determinant, could indicate both the need to incorporate additional processes (e.g. biogeographic and evolutionary history or trophic interactions) and/or the existence of a shared trend in detection biases among taxa and regions. PMID:20637092

2010-01-01

6

Sweet Conclusion  

ERIC Educational Resources Information Center

Jen Harrington is the owner and pastry chef of Sweet Conclusion, a bakery in Tampa, Florida. Most of Harrington's business comes from baking wedding cakes, but she has been attempting to attract customers to her retail bakery, where she sells cupcakes, pies, ice cream, and coffee. Nearly four years she opened Sweet Conclusion, the retail part of…

Shirley, Britt M.; Wooldridge, Barbara Ross; Camp, Kerri M.

2012-01-01

7

Cross-taxon congruence and environmental conditions  

Microsoft Academic Search

BACKGROUND: Diversity patterns of different taxa typically covary in space, a phenomenon called cross-taxon congruence. This pattern has been explained by the effect of one taxon diversity on taxon diversity, shared biogeographic histories of different taxa, and\\/or common responses to environmental conditions. A meta-analysis of the association between environment and diversity patterns found that in 83 out of 85 studies,

Carolina Toranza; Matías Arim

2010-01-01

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

What environmental conditions encourage shallow mesoscale organization?  

NASA Astrophysics Data System (ADS)

From observations, shallow trade-wind precipitation was found to be associated with mesoscal arcs, which encircled cloud-free cold pools. Here several WRF-LES idealized simulations have been conducted to investigate the factors affecting the mesoscale organizations of shallow trade wind cumuli, including wind shear, cloud droplet number concentration (CDNC), and environmental moisture. Each of these simulations, employing RICO environment profile, is a 12-hour run in a 30km*30km*4km domain with resolution of 100m horizontally and ~80m vertically. Environment having large wind shear favors the formation of mesoscale organization, whereas shallow cumuli randomly scatter in the environment with small wind shear. Under the former conditions, the wind shear induced separation of cumulus updraft and rain-containing downdraft stimulates the development of cumulus aloft and the attendant cold pool near the surface. But in all wind shear cases, cloud fraction, cloud- and domain-averaged LWP just have a little difference. Given approximately the same amount of water vapor content, CDNC determines the size of cloud droplets and thereafter the precipitation, by suppressing or benefiting the coalescence-collision among cloud droplets. Lack of enough precipitation, in highly aerosol-burdened environment, weakens the cold pool and associated mesoscale organization of shallow cumuli. Moisture is an important constraint on the growth of shallow cumuli. In our simulations with higher environmental moisture, cloud fraction, cloud- and domain- averaged LWP increases, and more precipitation falls down to the surface. Attendant cold pools and associated mesoscale arcs come up much earlier, and they also become stronger and span vaster. Furthermore, the expansion of cold pools, by inhibiting new formation of clouds due to the negative buoyancy in it, also lowers cloud fraction, cloud- and domain averaged LWP.

Wang, X.; Zuidema, P.

2012-12-01

10

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...

11

Benthic diatom response to changing environmental conditions  

NASA Astrophysics Data System (ADS)

In the Gulf of Trieste (northern Adriatic Sea, Italy) the benthic diatom community dynamics has been studied for seven years (1999-2005) at two sublittoral stations and related to variations of temperature, salinity, nutrient concentrations, freshwater inflow and mucilage. Bin-averaged temperature versus abundance of the main genera revealed that Nitzschia and Navicula presented a positive stepped trend with increasing temperature. An increase of ca. 860 ± 150 cells per cm3 per °C was calculated for Navicula and up to 590 ± 170 cells per cm3 per °C for Nitzschia. The genus Pleurosigma revealed a negative trend with increasing temperature, with a calculated decrease of ca. 140 ± 60 cells per cm3 per °C. A negative relation between Diploneis and temperature was found only in the shallower site. A peak of the tychopelagic genus Cylindrotheca was observed in correspondence with high salinity, but no significant results between bin-averaged salinity and benthic diatom abundance were found. Significant negative relations were obtained between bin-averaged abundance of Pleurosigma and H4SiO4 and NO3- at the deeper station and between the bin-averaged abundance of Gyrosigma and NH4+ at the coastal station. In this site the abundance of Gyrosigma showed a significant increasing trend over the study period. Navicula and Nitzschia seemed to suffer from the presence of mucilage events occurred in summer 2000 and 2004 whereas Diploneis occupied the ecological niche which remained temporarily uncovered by Navicula and Nitzschia. An exceptional freshwater plume with extremely high terrigenous input in November 2000 completely covered the benthic diatom community, causing a remarkable decrease in its total abundance in late autumn and winter 2000-01. The Gulf of Trieste may be considered a natural megacosm due to its geomorphologic characteristics and therefore the benthic diatom response to changing environmental conditions observed in this site could be extended beyond the geographical limits of this particular ecosystem.

Cibic, Tamara; Comici, Cinzia; Bussani, Andrea; Del Negro, Paola

2012-12-01

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 Elise

2014-01-01

15

Environmental Enteropathy: Critical implications of a poorly understood condition  

PubMed Central

Environmental enteropathy (also called tropical enteropathy) is a subclinical condition caused by constant fecal-oral contamination and resulting in blunting of intestinal villi and intestinal inflammation. Although these histological changes were discovered decades ago, the clinical impact of environmental enteropathy is just starting to be recognized. The failure of nutritional interventions and oral vaccines in the developing world may be attributed to environmental enteropathy, as the intestinal absorptive and immunologic functions are significantly deranged. Here we review the existing literature and examine potential mechanisms of pathogenesis for this poorly understood condition. PMID:22633998

Korpe, Poonum S.; Petri, William A.

2012-01-01

16

Eddy correlation measurements in wet environmental conditions  

NASA Astrophysics Data System (ADS)

The lower Feale catchment is a low-lying peaty area of 200 km^2 situated in southwest Ireland that is subject to inundation by flooding. The catchment lies adjacent to the Feale River and is subject to tidal signals as well as runoff processes. Various mitigation strategies are being investigated to reduce the damage due to flooding. Part of the effort has required development of a detailed hydrologic balance for the study area which is a wet pasture environment with local field drains that are typically flooded. An eddy correlation system was installed in the summer of 2002 to measure components of the energy balance, including evapotranspiration, along with special sensors to measure other hydrologic variables particular to this study. Data collected will be essential for validation of surface flux models to be developed for this site. Data filtering is performed using a combination of software developed by the Boundary-Layer Group (BLG) at Oregon State University together with modifications made to this system for conditions at this site. This automated procedure greatly reduces the tedious inspection of individual records. The package of tests, developed by the BLG for both tower and aircraft high frequency data, checks for electronic spiking, signal dropout, unrealistic magnitudes, extreme higher moment statistics, as well as other error scenarios not covered by the instrumentation diagnostics built into the system. Critical parameter values for each potential error were developed by applying the tests to real fast response turbulent time series. Potential instrumentation problems, flux sampling problems, and unusual physical situations records are flagged for removal or further analysis. A final visual inspection step is required to minimize rejection of physically unusual but real behavior in the time series. The problems of data management, data quality control, individual instrumentation sensitivity, potential underestimation of latent and sensible heat and possible sources of energy balance closure errors for this wet environment and micrometeorological conditions are discussed.

Cuenca, R. H.; Migliori, L.; O Kane, J. P.

2003-04-01

17

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...

18

40 CFR 86.1312-2007 - Filter stabilization and microbalance workstation environmental conditions, microbalance...  

Code of Federal Regulations, 2010 CFR

...Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED...microbalance workstation environmental conditions, microbalance...Available from the Institute of Environmental Standards and Technology website at...

2010-07-01

19

Marine Environmental Conditions off the Coasts of the United States,  

E-print Network

to a combination of heavy fishing and long-term changes in environmental conditions. Robert A. Pedrick knows that the chances of catching fish can be drastically affected by weather and weather" and are guided by weather and sea condi- tions in their fishing activities. The longer term, larger scale changes

20

Behavioral and Environmental Conditions associated with Shark Attacks on Humans  

E-print Network

Behavioral and Environmental Conditions associated with Shark Attacks on Humans By Joshua J AND METHODS 4 2.1 DATABASE 4 2.2 SPATIAL AND TEMPORAL DISTRIBUTION OF SHARK ATTACKS 9 2.3 VICTIMS OF SHARK ATTACK 10 2.4 CHARACTERISTICS OF ATTACKING SHARKS 11 3.0 RESULTS 11 3.1 SPATIAL AND TEMPORAL DISTRIBUTION

Worm, Boris

21

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

22

Studies of culture conditions and environmental stability of human metapneumovirus  

Microsoft Academic Search

Human metapneumovirus (HMPV) is a paramyxovirus that is a leading cause of acute respiratory disease. HMPV is difficult to cultivate and limited published data describe the in vitro growth characteristics of the virus and its ability to replicate in different cell lines. Stability of HMPV to different temperatures or environmental conditions has not been described. Nosocomial infections due to HMPV

Sharon J. Tollefson; Reagan G. Cox; John V. Williams

2010-01-01

23

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

24

Can environmental conditions experienced in early life influence future generations?  

PubMed Central

The consequences of early developmental conditions for performance in later life are now subjected to convergent interest from many different biological sub-disciplines. However, striking data, largely from the biomedical literature, show that environmental effects experienced even before conception can be transmissible to subsequent generations. Here, we review the growing evidence from natural systems for these cross-generational effects of early life conditions, showing that they can be generated by diverse environmental stressors, affect offspring in many ways and can be transmitted directly or indirectly by both parental lines for several generations. In doing so, we emphasize why early life might be so sensitive to the transmission of environmentally induced effects across generations. We also summarize recent theoretical advancements within the field of developmental plasticity, and discuss how parents might assemble different ‘internal’ and ‘external’ cues, even from the earliest stages of life, to instruct their investment decisions in offspring. In doing so, we provide a preliminary framework within the context of adaptive plasticity for understanding inter-generational phenomena that arise from early life conditions. PMID:24807254

Burton, Tim; Metcalfe, Neil B.

2014-01-01

25

The effect and role of environmental conditions on magnetosome synthesis.  

PubMed

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

26

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

27

Quantum state Conclusions  

E-print Network

Quantum state transfer Device Conclusions Quantum state transfer Deterministic quantum state with C.W.J. Beenakker Phys. Rev. B 73 (2006), 121307(R) #12;Quantum state transfer Device Conclusions Outline Quantum state transfer Device Conclusions #12;Quantum state transfer Device Conclusions Quantum

van den Brink, Jeroen

28

Ecological Conditions Favoring Budding in Colonial Organisms under Environmental Disturbance  

PubMed Central

Dispersal is a topic of great interest in ecology. Many organisms adopt one of two distinct dispersal tactics at reproduction: the production of small offspring that can disperse over long distances (such as seeds and spawned eggs), or budding. The latter is observed in some colonial organisms, such as clonal plants, corals and ants, in which (super)organisms split their body into components of relatively large size that disperse to a short distance. Contrary to the common dispersal viewpoint, short-dispersal colonial organisms often flourish even in environments with frequent disturbances. In this paper, we investigate the conditions that favor budding over long-distance dispersal of small offspring, focusing on the life history of the colony growth and the colony division ratio. These conditions are the relatively high mortality of very small colonies, logistic growth, the ability of dispersers to peacefully seek and settle unoccupied spaces, and small spatial scale of environmental disturbance. If these conditions hold, budding is advantageous even when environmental disturbance is frequent. These results suggest that the demography or life history of the colony underlies the behaviors of the colonial organisms. PMID:24621824

Nakamaru, Mayuko; Takada, Takenori; Ohtsuki, Akiko; Suzuki, Sayaki U.; Miura, Kanan; Tsuji, Kazuki

2014-01-01

29

Effectiveness of Dry Eye Therapy Under Conditions of Environmental Stress  

PubMed Central

Purpose: Dry eye is often characterized by increased tear evaporation due to poor tear film quality, especially of the lipid component of the tear film. Using an environmental chamber to induce environmental stress, this study compared the effect of three lubricant eye drops on various aspects of tear physiology in a crossover design (evaporation was the principal outcome measure). Methods: Three eye drop formulas were tested: 0.5% carmellose sodium (Drop C), 0.5% carmellose sodium with added lipid (Drop C-L) and 1.0% glycerine with added lipid (Drop G-L). Nineteen control and 18?dry eye subjects used each product for 2 weeks, three times per day, in a random order, with a minimum 1-week washout between treatment periods. Tear evaporation, break up time, osmolarity, tear structure (by interferometry) and patient symptoms were assessed with the subjects adapted for 10?min in an environmental chamber controlled at 20% relative humidity and 22?°C. The treatment effects were analyzed using general linear model repeated measures analyses of variance. Results: In dry eye subjects, evaporation, break up time, osmolarity and symptoms improved for all formulas (p?Conclusion: Overall, the eye drop formula containing both carmellose sodium and lipid (C-L) produced a greater treatment effect on tear evaporation than the other formulations containing only one of these ingredients. This study also demonstrates the utility of a controlled environmental chamber in showing the difference in performance between dry eye treatments. PMID:23294168

Madden, Louise C.; Simmons, Peter A.

2013-01-01

30

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...

31

An experimental performance evaluation of a novel radio-transmitter identification system under diverse environmental conditions  

Microsoft Academic Search

In this paper, the effects of environmental conditions on a radio-transmitter identification system are investigated. Transmissions from 10 commercial VHF FM transmitters operating under varying environmental conditions are analyzed using an experimental setup. It is observed that a change in environmental conditions such as battery voltage or ambient temperature causes the feature vectors to spread over the feature space, resulting

O. H. Tekbas; N. Serinken; O. Ureten

2004-01-01

32

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

33

K, U, and Th behavior in Martian environmental conditions  

NASA Technical Reports Server (NTRS)

The possibility of K, U, and Th content determination from orbit and in situ allows consideration of those elements as geochemical indicators in the planetary studies. In the case of Mars the unambiguous interpretations of such data in terms of igneous rocks are remarkably constrained by the widespread rock alteration and the existence of exogenic deposits. Besides, the terrestrial experience indicates that K, U, and Th contents could be used as indicators of environmental geochemical processes. Thus the determination of K, U, and Th contents in the Martian surface materials could provide the indirect data on the conditions of some exogenic geological processes. The speculations on the K, U, and Th behavior in the Martian environments show that aeolian and aqueous processes leads to the preferential accumulation of K, U, and Th in fine dust material. The separation of K, U, and Th on Mars is smaller in scale to that on Earth.

Zolotov, M. YU.; Krot, T. V.; Moroz, L. V.

1993-01-01

34

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

35

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

36

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

37

Exceeding the resolving imaging power using environmental conditions.  

PubMed

We present two approaches that use the environmental conditions in order to exceed the classical Abbe's limit of resolution of an aperture-limited imaging system. At first we use water drops in order to improve the resolving capabilities of an imaging system using a time-multiplexing approach. The limit for the resolution improvement capabilities is equal to the size of the rain drops. The rain drops falling close to the imaged object act as a sparse and random high-resolution mask attached to it. By applying proper image processing, the center of each falling drop is located, and the parameters of the encoding grating are extracted from the captured set of images. The decoding is done digitally by applying the same mask and time averaging. In many cases urban environment includes periodic or other high-resolution objects such as fences. Actually urban environment includes many objects of this type since from an engineering point of view they are considered appealing. Those objects follow well known standards, and therefore their structure can be a priori known even without being fully capable of imaging them. We show experimentally how we use such objects in order to superresolve the contour of moving targets passing in front of them. PMID:18239690

Zalevsky, Zeev; Saat, Efi; Orbach, Shahar; Mico, Vicente; Garcia, Javier

2008-02-01

38

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 connectivity conditions. E. Pitoura ­ Summer School on Mobile Computing, Jyvaskyla, 1998 1 #12; ' & $ % Mobile

Pitoura, Evaggelia

39

Conclusions and Recommendations  

Microsoft Academic Search

The first and most visible conclusion to be drawn from the articles combined in this volume is that space applications provide\\u000a almost endless opportunities for dealing with problems related to sustainability. Space applications have become important,\\u000a if not indispensable tools for supporting solutons to natural and human-made problems facing global society. Threats and risks\\u000a can be projected and sustainability can

Kai-Uwe Schrogl; Charlotte Mathieu; Agnieszka Lukaszczyk

40

Is Clutch Size in Birds Affected by Environmental Conditions during Growth?  

Microsoft Academic Search

Only environmental conditions occurring at the time of breeding have been shown to affect clutch size in birds, even though conditions experienced during growth are known to affect body size or egg size. We show here that environmental conditions experienced during early life can affect clutch size in captive zebra finches (Taeniopygia guttata) and wild great tits (Parus major). Not

S. Haywood; C. M. Perrins

1992-01-01

41

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

42

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

43

The role of an alpha animal in changing environmental conditions.  

PubMed

The maintenance and development of conservation areas by grazing of large herbivores, such as Przewalski's horses, is common practice. Several nature conservation areas house male bachelor groups of this species. When males are needed for breeding they are removed from the groups, often without considering group compositions and individual social positions. However, alpha animals are needed for ensuring group stability and decision making in potentially dangerous situations in several species. To investigate the role of the alpha male in a bachelor group, we observed the behaviour of five Przewalski's horse males during the enlargement of their enclosure. We analyzed the group's social structure and movement orders, as well as the animals' connectedness, activity budgets, and whether they moved with preferred group members and how factors such as social rank influenced the horses' behaviour. We also investigated the excretion of glucocorticoid metabolites (GCM) via faeces of the horses while exploring a new area as a parameter of glucocorticoid production. Our results show that the alpha male is important for a bachelor group in changing environmental conditions. The alpha male had the highest level of connectedness within the group. When exploring the new environment, its position in the group changed from previously being the last to being the first. Furthermore the whole group behaviour changed when exploring the new area. The stallions showed reduced resting behavior, increased feeding and did not stay close to each other. We found that the excretion of glucocorticoid metabolites of most horses rose only marginally during the first days on the new area while only the alpha male showed a significant increased amount of glucocorticoid production during the first day of the enclosure enlargement. PMID:24878311

Wolter, Riccarda; Pantel, Norbert; Stefanski, Volker; Möstl, Erich; Krueger, Konstanze

2014-06-22

44

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

45

BENTHIC MACROINVERTEBRATES AS INDICATORS OF ENVIRONMENTAL CONDITION IN THREE GREAT LAKES  

EPA Science Inventory

Biological, physical, and chemical data were collected from surficial sediments of Lakes Ontario, Michigan, and Superior to examine benthic macroinvertebrate community structure as an indicator of environmental condition....

46

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...

47

Salt studies: Conclusions  

NASA Astrophysics Data System (ADS)

This report represents the conclusion of the compressed air energy storage (CAES) program in salt. It includes a brief background of salt cavity studies and utilization for CAES, the focuses on long-term stability criteria for solution mined salt cavities. Summary statements are made on some of the more important criteria and their significance for operational peaking-power plants utilizing salt cavities for CAES reservoirs. The concluding section of this report incorporates a discussion of the future for CAES in U.S. salt deposits. This discussion is based mainly on technical considerations, since they have been the main consideration in this particular study. Obviously, economic analyses will dominate decisions by utilities on construction schedules for any technically feasible CAES study.

Thoms, R. L.; Gehle, R. M.

1982-12-01

48

A nanofluidic device for single molecule studies with in situ control of environmental solution conditions  

E-print Network

We report an approach to study the in situ conformational response of single biomolecules such as DNA to a change in environmental solution conditions. These conditions are, for example, the composition of the buffer or ...

Zhang, Ce

49

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

50

INTEGRATED ASSESSMENTS OF THE ENVIRONMENTAL CONDITION OF THE CHESAPEAKE BAY  

EPA Science Inventory

The Chesapeake Bay, the Nation's largest estuary, has experienced environmental degradation due to nutrient enrichment, contamination, loss of habitat, and over-harvesting of living resources. Resource managers need information on the extent of degradation to formulate restoratio...

51

The effects of adverse environmental conditions on workload  

E-print Network

; Loeb, 1958; Finkleman and Glass, 1970; Jerison, 1959), environmental factors have been shown to affect human operator performance significantly. Since it has been found in many of these studies that environmental factors can have a detrimental... Background A pr1mary area for future industrial engineering research should be the area of human factors engineering. A major aspect of human factors eng1neering is determining the effects of a system on a human operator's performance. In many cases...

Martin, Ann Elizabeth

1975-01-01

52

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

53

Early growth conditions, phenotypic development and environmental change  

Microsoft Academic Search

Phenotypic development is the result of a complex interplay involving the organism's own genetic make-up and the environment it experiences during development. The latter encompasses not just the current environment, but also indirect, and sometimes lagged, components that result from environmental effects on its parents that are transmitted to their developing offspring in various ways and at various stages. These

Pat Monaghan

2007-01-01

54

Differential effects of genetic vs. environmental quality in Drosophila melanogaster suggest multiple forms of condition dependence.  

PubMed

Condition is a central concept in evolutionary ecology, but the roles of genetic and environmental quality in condition-dependent trait expression remain poorly understood. Theory suggests that condition integrates genetic, epigenetic and somatic factors, and therefore predicts alignment between the phenotypic effects of genetic and environmental quality. To test this key prediction, we manipulated both genetic (mutational) and environmental (dietary) quality in Drosophila melanogaster and examined responses in morphological and chemical (cuticular hydrocarbon, CHC) traits in both sexes. While the phenotypic effects of diet were consistent among genotypes, effects of mutation load varied in magnitude and direction. Average effects of diet and mutation were aligned for most morphological traits, but non-aligned for the male sexcombs and CHCs in both sexes. Our results suggest the existence of distinct forms of condition dependence, one integrating both genetic and environmental effects and the other purely environmental. We propose a model to account for these observations. PMID:25649176

Bonduriansky, Russell; Mallet, Martin A; Arbuthnott, Devin; Pawlowsky-Glahn, Vera; Egozcue, Juan José; Rundle, Howard D

2015-04-01

55

Environmental condition assessment of US military installations using GIS based spatial multi-criteria decision analysis.  

PubMed

Environment functions in various aspects including soil and water conservation, biodiversity and habitats, and landscape aesthetics. Comprehensive assessment of environmental condition is thus a great challenge. The issues include how to assess individual environmental components such as landscape aesthetics and integrate them into an indicator that can comprehensively quantify environmental condition. In this study, a geographic information systems based spatial multi-criteria decision analysis was used to integrate environmental variables and create the indicator. This approach was applied to Fort Riley Military installation in which land condition and its dynamics due to military training activities were assessed. The indicator was derived by integrating soil erosion, water quality, landscape fragmentation, landscape aesthetics, and noise based on the weights from the experts by assessing and ranking the environmental variables in terms of their importance. The results showed that landscape level indicator well quantified the overall environmental condition and its dynamics, while the indicator at level of patch that is defined as a homogeneous area that is different from its surroundings detailed the spatiotemporal variability of environmental condition. The environmental condition was mostly determined by soil erosion, then landscape fragmentation, water quality, landscape aesthetics, and noise. Overall, environmental condition at both landscape and patch levels greatly varied depending on the degree of ground and canopy disturbance and their spatial patterns due to military training activities and being related to slope. It was also determined the environment itself could be recovered quickly once military training was halt or reduced. Thus, this study provided an effective tool for the army land managers to monitor environmental dynamics and plan military training activities. Its limitation lies at that the obtained values of the indicator vary and are subjective to the experts' knowledge and experience. Thus, further advancing this approach is needed by developing a scientific method to derive the weights of environmental variables. PMID:22684636

Singer, Steve; Wang, Guangxing; Howard, Heidi; Anderson, Alan

2012-08-01

56

Environmental Condition Assessment of US Military Installations Using GIS Based Spatial Multi-Criteria Decision Analysis  

NASA Astrophysics Data System (ADS)

Environment functions in various aspects including soil and water conservation, biodiversity and habitats, and landscape aesthetics. Comprehensive assessment of environmental condition is thus a great challenge. The issues include how to assess individual environmental components such as landscape aesthetics and integrate them into an indicator that can comprehensively quantify environmental condition. In this study, a geographic information systems based spatial multi-criteria decision analysis was used to integrate environmental variables and create the indicator. This approach was applied to Fort Riley Military installation in which land condition and its dynamics due to military training activities were assessed. The indicator was derived by integrating soil erosion, water quality, landscape fragmentation, landscape aesthetics, and noise based on the weights from the experts by assessing and ranking the environmental variables in terms of their importance. The results showed that landscape level indicator well quantified the overall environmental condition and its dynamics, while the indicator at level of patch that is defined as a homogeneous area that is different from its surroundings detailed the spatiotemporal variability of environmental condition. The environmental condition was mostly determined by soil erosion, then landscape fragmentation, water quality, landscape aesthetics, and noise. Overall, environmental condition at both landscape and patch levels greatly varied depending on the degree of ground and canopy disturbance and their spatial patterns due to military training activities and being related to slope. It was also determined the environment itself could be recovered quickly once military training was halt or reduced. Thus, this study provided an effective tool for the army land managers to monitor environmental dynamics and plan military training activities. Its limitation lies at that the obtained values of the indicator vary and are subjective to the experts' knowledge and experience. Thus, further advancing this approach is needed by developing a scientific method to derive the weights of environmental variables.

Singer, Steve; Wang, Guangxing; Howard, Heidi; Anderson, Alan

2012-08-01

57

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

58

Conclusion  

Microsoft Academic Search

\\u000a The historical impact of colonization has predisposed post-colonial people of color to the internalization of Western skin\\u000a color ideals. Overtly motivated by post-colonials and covertly condoned by people of color, racism via skin color is an unspoken\\u000a factor in the various confrontations encountered by people of color with social institutions. Their color also correlates\\u000a with a lack of economic and

Ronald E. Hall

59

Conclusion  

Microsoft Academic Search

\\u000a The aim of this book was to provide a critical introduction to a number of “formal decision and evaluation methods”. By this,\\u000a we mean a set of explicit and well-defined rules to collect, assess and process information in order to make recommendations\\u000a in decision and\\/or evaluation processes. Although these methods may not be entirely formalised, their underlying logic should\\u000a be

Denis Bouyssou; Thierry Marchant; Marc Pirlot; Patrice Perny; Alexis Tsoukiàs; Philippe Vincke

60

Conclusion  

NASA Astrophysics Data System (ADS)

In this book, we have shown that the generative capacity and the parsing complexity of lexicalized grammar formalisms can be systematically related to structural properties of the dependency graphs that these formalisms can induce. In this way, we have generalized Gaifman's [1965] equivalence result from context-free generative capacity and projective dependency structures on the one hand to mildly context-sensitive generative capacity and 'mildly' non-projective dependency structures on the other.

Kuhlmann, Marco

61

Conclusions  

Cancer.gov

An integrated, multidisciplinary approach to early detection and risk assessment is likely to be more successful in cancer prevention than any other approach. For example, the linkage of early detection research to active screening trials or to prevention studies would accelerate the validation of biomarkers. Both molecular markers and interventions may be evaluated in the same study or trial, a potential saving in time and resources.

62

Ubiquinone concentrations in Athiorhodaceae grown under various environmental conditions  

PubMed Central

1. The nature and concentration of ubiquinone in six species of Athiorhodaceae have been examined after growth under aerobic and photosynthetic conditions. 2. Increase in ubiquinone concentration during adaptive synthesis of photosynthetic pigments by Rhodopseudomonas spheroides incubated under low-aeration conditions was observed. 3. The nature of the carbon source was found to have a marked effect on ubiquinone, as well as bacteriochlorophyll, concentrations. PMID:5862408

Carr, N. G.; Exell, G.

1965-01-01

63

Environmental stress cracking of plastics under dynamic conditions  

E-print Network

of the earliest test methods which later on became an ASTM standard is the bent strip test, described in the ASTM test for environmental stress cracking of ethylene plastics (ASTM D-1693). This test [15] is performed on rectangular plastic specimens... proposed to determine the stress cracking resistance of polymers by Tonyali and Fernando [19]. It is known as the 3-point bend test and uses compression notched molded plaques with dimensions of 13 15 cm x 15 cm x 0. 6 cm. The test unit was built in a...

Suresh, Mitta

1992-01-01

64

Which environmental conditions and core precipitation characteristics led to the rapid intensification of Hurricane Earl (2010)?  

NASA Astrophysics Data System (ADS)

Global analysis fields, infrared and passive microwave satellite observations, lightning data, and airborne radar reflectivity and dual-Doppler wind analyses show the evolution of environmental conditions, precipitation characteristics, and kinematic structure before, during, and after the rapid intensification (RI) of Hurricane Earl (2010). The relationship between the RI and environmental conditions, intense inner-core convection, inner-core precipitation coverage, core cold-cloud precipitation symmetry, and the radial distribution of convection is examined. The onset of RI occurs despite moderate vertical wind shear. An episode of intense convection occurs before the RI onset, but an examination of the mesoscale and convective-scale kinematic processes during this convective 'burst' suggests that the strength of convection alone did not cause the onset of RI. Instead, the dual-Doppler, lightning, and microwave data suggest that the precipitation characteristic that ultimately led to the onset of RI was an increasing trend in cold-cloud precipitation symmetry following the migration of inner-core convection into the northeastern and northern quadrants of the storm within a few hours before RI onset. The evolution of precipitation during the RI suggests that the most important inner-core precipitation characteristics supporting RI are the cold-cloud precipitation symmetry and the predominance of strong convective updrafts within (instead of outside of) the radius of maximum wind (RMW). The wind and precipitation data from Earl indicate that the RMW at multiple levels must be examined. When the RMW is substantially slanted, only considering the low-level RMW can lead to the false conclusion that the strongest convection is located outside of the RMW.

Susca-Lopata, Gabriel Anthony

65

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...

66

Project 198740100 Assessment of Smolt Condition: Biological and Environmental Interactions  

E-print Network

-river survival/estuary * * * * * temperature * * precocity/residualism--control by growth and temperature, higher at production facilities ­ density, temperature, flow, water quality, feed enhancement, release condition for three water quality variables, which include temperature and changes in temperature, and average monthly

67

The Presence of Nanophase Al-Si-Fe Components at Mawrth Vallis Indicate Varying Environmental Conditions  

NASA Astrophysics Data System (ADS)

The presence of nanophase allophane, opal and Fe-rich material at Mawrth Vallis together with multiple phyllosilicates indicate varying environmental conditions over time and also suggests regionally different aqueous environments.

Bishop, J. L.; Rampe, E. B.

2014-07-01

68

A Four-day Workweek: a Policy for Improving Employment and Environmental Conditions in Europe  

E-print Network

Can working less lead to a healthier economy and better environmental conditions? Which factors should be taken into consideration when forming an answer to this question? In this article Nicholas Ashford and Giorgos Kallis ...

Ashford, Nicholas A.

69

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...

70

Adoption of improved irrigation and drainage reduction technologies under limiting environmental conditions  

Microsoft Academic Search

Modern irrigation technologies have been suggested as a means of conserving scarce water and reducing environmental pollution caused by irrigated agriculture. This paper applies an economic model of technology selection that provides a general framework to analyzing adoption of irrigation technologies under various environmental conditions. Data from the San Joaquin Valley of California is used to verify the theoretical relationships.

Ariel Dinar; Mark B. Campbell; David Zilberman

1992-01-01

71

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

72

Environmental enrichment alters neuronal processing in the nucleus accumbens core during appetitive conditioning  

Microsoft Academic Search

Although the core region of the nucleus accumbens (NAcc) has been implicated in motor control and the acquisition of appetitive learning, these processes are altered by environmental experience. To assess how environment influences neuronal processing in NAcc core, we recorded single-unit activity during acquisition of an appetitive learning task in which rats reared in an environmentally enriched condition (EC) learned

David A. Wood; George V. Rebec

2009-01-01

73

Flexible DCP interface. [signal conditioning system for use with Kansas environmental sensors  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. A user of an ERTS data collection system must supply the sensors and signal conditioning interface. The electronic interface must be compatible with the NASA-furnished data collection platform (DCP). A universal signal conditioning system for use with a wide range of environmental sensors is described. The interface is environmentally and electronically compatible with the DCP and has operated satisfactorily for a complete winter wheat growing season in Kansas.

Kanemasu, E. T. (principal investigator); Schimmelpfenning, H.

1974-01-01

74

Tillage-induced environmental conditions in soil and substrate limitation determine biogenic gas production  

Microsoft Academic Search

Tillage changes soil environmental conditions and controls the distribution of residues in the soil, both actions that affect the production and emission of soil biogenic gases (CO2, N2O, and CH4). The objective of this study was to determine how tillage-induced environmental conditions and substrate quality affect the mineralization rate of easily metabolizable compounds and the subsequent production of these gases.

E. G. Gregorich; P. Rochette; D. W. Hopkins; U. F. McKim; P. St-Georges

2006-01-01

75

Pre-convective environmental conditions indicative of non-tornadic severe thunderstorm winds over Southeast Florida  

E-print Network

PRE-CONVECTIVE ENVIRONMENTAL CONDITIONS INDICATIVE OF NON-TORNADIC SEVERE THUNDERSTORM WINDS OVER SOUTHEAST FLORIDA A Thesis by JEFFREY MICHAEL WILHELM Submitted to the Graduate College of Texas ARM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1987 Major Subject: Meteorology PRE-CONVECTIVE ENVIRONMENTAL CONDITIONS INDICATIVE OF NON-TORNADIC SEVERE THUNDERSTORM WINDS OVER SOUTHEAST FLORIDA A Thesis by JEFFREY MICHAEL WILHELM Approved...

Wilhelm, Jeffrey Michael

1987-01-01

76

Evaluating Microbial Indicators of Environmental Condition in Oregon Rivers  

Microsoft Academic Search

Traditional bacterial indicators used in public health to assess water quality and the Biolog® system were evaluated to compare\\u000a their response to biological, chemical, and physical habitat indicators of stream condition both within the state of Oregon\\u000a and among ecoregion aggregates (Coast Range, Willamette Valley, Cascades, and eastern Oregon). Forty-three randomly selected\\u000a Oregon river sites were sampled during the summer

ALAN T. PENNINGTON; ANNA K. HARDING; CHARLES W. HENDRICKS; HEIDI M. K. CAMPBELL

2001-01-01

77

Is clutch size in birds affected by environmental conditions during growth?  

PubMed

Only environmental conditions occurring at the time of breeding have been shown to affect clutch size in birds, even though conditions experienced during growth are known to affect body size or egg size. We show here that environmental conditions experienced during early life can affect clutch size in captive zebra finches (Taeniopygia guttata) and wild great tits (Parus major). Not only do factors outside the immediate breeding season affect clutch size, but clutch size control mechanism is permanently influenced by conditions experienced during ontogeny. PMID:1360680

Haywood, S; Perrins, C M

1992-08-22

78

Photodermatoses: environmentally induced conditions with high psychological impact.  

PubMed

Photodermatoses are a group of skin disorders caused or exacerbated by ultraviolet and/or visible radiation, which collectively affect a high proportion of the population and substantially affect quality of life (QoL). Our objective was to assess the psychological impact of these conditions. Patients with a range of photodermatoses diagnosed at a specialist investigation centre in the UK completed questionnaires evaluating (i) anxiety and (ii) depression, using the Hospital Anxiety and Depression Scale (HADS), (iii) social anxiety, using the Fear of Negative Evaluation measure (FNE), (iv) coping strategies (brief COPE) and (v) QoL, using the Dermatology Life Quality Index (DLQI). Questionnaires were returned by 185 of 260 patients (71.1% response rate). Mean age was 50.2 years (SD 14.5, range 20-85), 80.3% female. Polymorphic light eruption was the most common diagnosis, followed by photoaggravated eczema, other photoaggravated dermatological conditions and solar urticaria. Across the sample, high percentages, i.e. 23% and 7.9% of individuals, showed scores indicating clinical levels of anxiety and depression, respectively. Facial involvement was a strong indicator for depression (t = 2.7, p < 0.01). In regression analyses psychological factors (particularly depression and adaptive coping) were the principle predictors of QoL, accounting for 17.7% of the variance (F = 7.61, p < 0.01), while clinical variables accounted for an additional 10.1% (F = 8.96, p < 0.01), with number of months/year affected exerting a significant effect (p < 0.01). This study demonstrates the high psychological comorbidity of these conditions; more awareness of this is required, with adoption of a biopsychosocial approach to their management. PMID:22961505

Rizwan, Muneeza; Reddick, Charlotte Louise; Bundy, Christine; Unsworth, Rebecca; Richards, Helen Louise; Rhodes, Lesley Elizabeth

2013-01-01

79

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

80

Rift Valley Fever outbreaks in Mauritania and related environmental conditions.  

PubMed

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

81

Migration of birds as an indicator of broad-scale environmental condition.  

PubMed

The migration of Neotropical birds may provide a robust measure of changing environmental condition along the migratory route. I review previous work on assessing broad-scale stopover quality in the eastern United States and discuss how future research can aid regional environmental assessment. Scientists can quantify how environmental changes affect the migratory system, and then monitor for those effects on migrant abundance from year to year. The cyclical nature of migration provides a constant re-evaluation of habitat quality and spatial distribution by migrant birds. Avian monitoring programs can detect changes in migrant abundance. Migrating birds may thus provide a living sensor of environmental change, enabling broad-scale environmental assessments to detect and address habitat degradation early on, allowing local managers to prioritize restoration efforts accordingly. Understanding the environmental factors driving stopover selection, and how birds move between stopovers during migration, is an important first step. PMID:15141446

Tankersley, Roger D

2004-06-01

82

Survival of Pseudodiplorchis americanus (Monogenea) under controlled environmental conditions.  

PubMed

Populations of Pseudodiplorchis americanus infecting the desert toad, Scaphiopus couchii, have previously been shown to be remarkably stable from year to year, despite wide variation in conditions promoting invasion. The present study aimed to document the survival of both first-year and pre-existing adults under controlled laboratory temperatures. First-year worm survival in experimentally infected toads was shown to be very high for the first 5 months after migration to the definitive site, and there was no difference in survival at 25 degrees C or 15-20 degrees C. There was also no density-dependent survival during the same period: 20% of worms were recovered from the host urinary bladder, irrespective of initial intensities. After the first 5 months, there was a progressive loss of worms in toads maintained at 25 degrees C but not at 15-20 degrees C. Pre-existing adult populations were shown to be virtually identical to those under natural conditions for the first 4 months after toad capture. Following this, at 25 degrees C, populations declined and no pre-existing adults were recovered after 11-14 months. There was no such loss of pre-existing adults at 15-20 degrees C for up to 14 months. A diurnal temperature cycle of 20-34 degrees C (simulating temperatures during the desert summer) did not lead to a significant loss of worms. These observations suggest that during one annual cycle in the desert, when temperatures remain above 20 degrees C for less than 6 months, most adult worms established in the host urinary bladder will survive to the next transmission opportunity. However, the similar longevity of first-year and pre-existing adults in laboratory maintained toads shows that loss of worms cannot be due solely to parasite ageing. Temperature-dependent survival of P. americanus is suggestive of a host immune response. Low temperatures, which inhibit parasite growth and development, are essential for the survival of P. americanus. PMID:8159464

Tocque, K; Tinsley, R C

1994-02-01

83

Health and Nutritional Status Related To Socioeconomic Conditions and Environmental Health In Honduras, Central America  

Microsoft Academic Search

LEARNING OUTCOME: To identify conditions associated with poor health and nutritional status in children living in Honduras in order to plan future outreach and intervention programs in similar underdeveloped communities.The interwoven nature of poverty, illness, malnutrition, and unsanitary environmental conditions common in underdeveloped communities of the world contribute to inadequate health and nutritional status of children. The purpose of this

K. H. Register; P. B. Brevard; M. L. Ball; J. M. Pearson; R. J. Domangue

1997-01-01

84

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

85

3 Environmental Conditions 3.1 Characterization of Aquatic Habitat Conditions  

E-print Network

, but is variable due to climatic conditions. In general, tributary habitat is used for salmonid spawning. Most LWD is recruited from the forests in Nevada rather than the high deserts of Idaho (Parrish 1998

86

Regulation of free corticosterone and CBG capacity under different environmental conditions in altricial nestlings.  

PubMed

The concentration of circulating glucocorticoids is regulated in response to environmental and endogenous conditions. Total circulating corticosterone, the main glucocorticoid in birds, consists of a fraction which is bound to corticosterone-binding globulins (CBG) and a free fraction. There is increasing evidence that the environment modulates free corticosterone levels through varying the concentration of CBG, but experimental evidence is lacking. To test the hypothesis that the regulation of chronic stress in response to endogenous and environmental conditions involves variation in both corticosterone release and CBG capacity, we performed an experiment with barn owl (Tyto alba) nestlings in two different years with pronounced differences in environmental conditions and in nestlings experimentally fed ad libitum. In half of the individuals we implanted a corticosterone-releasing pellet to artificially increase corticosterone levels and in the other half we implanted a placebo pellet. We then repeatedly collected blood samples to measure the change in total and free corticosterone levels as well as CBG capacity. The increase in circulating total corticosterone after artificial corticosterone administration varied with environmental conditions and with the food regime of the nestlings. The highest total corticosterone levels were found in nestlings growing up in poor environmental conditions and the lowest in ad libitum fed nestlings. CBG was highest in the year with poor environmental conditions, so that, contrary to total corticosterone, free corticosterone levels were low under poor environmental conditions. When nestlings were fed ad libitum total corticosterone, CBG and free corticosterone did not increase when administering corticosterone. These results suggest that depending on the individual history an animal experienced during development the HPA-axis is regulated differently. PMID:19467233

Almasi, Bettina; Roulin, Alexandre; Jenni-Eiermann, Susanne; Breuner, Creagh W; Jenni, Lukas

2009-01-01

87

Ten-year variability in fluxes, meteorology, and environmental conditions at a Colorado subalpine forest site  

NASA Astrophysics Data System (ADS)

Changing meteorological and environmental conditions affect fluxes; model analysis has shown that environmental variability directly accounts for about half the interannual variability in net ecosystem exchange (NEE) of CO2 whereas the other 50% is due to biotic responses to these changing variables (Richardson et al. 2007). In our study, ten years (1998-2008) of turbulent flux measurements of heat, water vapor, and CO2 at the Niwot Ridge AmeriFlux site (Monson et al. 2002) are examined with respect to meteorological conditions (atmospheric temperature, stability, precipitation, and cloudiness) as well as changes in environmental conditions, such as snow depth and soil moisture. The typical yearly cycle and an estimate of the magnitude of year-to-year variability in the diurnal fluxes and other variables for a high-elevation subalpine forest ecosystem are presented. Wintertime ecosystem respiration has an average 30-min NEE of 0.62 ?mol m-2 s-1 with an interannual range between 0.5-1 ?mol m-2 s-1. Uptake of CO2 in late summer has an average NEE of -0.71 ?mol m-2 s-1 with an interannual range between -0.1 to -1.5 ?mol m-2 s-1. Previous studies at the Niwot Ridge AmeriFlux site have described the importance of photosynthetic photon flux density (PPFD) (Monson et al. 2002) and also growing season length (Hu et al. 2009) on NEE. Water isotope ratios analyzed by Hu et al. (2009) have shown that trees at the site primarily rely on water from snowmelt to sustain them throughout the summer; combining this result with the SIPNET model, Hu et al. conclude that there is a limited connection between summer precipitation and the cumulative annual gross primary production (GPP). We have tested this conclusion more explicitly by examining the response of NEE to specific precipitation events and the effect of extended dry periods on the diel cycle of the fluxes, CO2 mole fraction, sap flow, and other meteorological and soil variables. Additionally, we examine the connection between seasonal changes in NEE to changes in CO2 mole fraction measured with a tunable diode laser at the site (Schaeffer et al. 2008). References: Hu, J., et al., 2009: Longer growing seasons lead to less carbon sequestration by a subalpine forest. Global Change Biology, doi:10.1111/j.1365-2486.2009.01967.x Monson, R. K., et al., 2002: Carbon sequestration in a high-elevation, subalpine forest. Global Change Biology, 8, 459-478. Richardson, A.D., et al., 2007: Environmental variation is directly responsible for short- but not long-term variation in forest-atmosphere carbon exchange. Global Change Biology, 13, 788-803. Schaeffer, S.M., et al., 2008: Long-term field performance of a tunable diode laser absorption spectrometer for analysis of carbon isotopes of CO2 in forest air. Atmospheric Chemistry and Physics, 8, 5263-5277.

Burns, S. P.; Turnipseed, A.; Bowling, D. R.; Hu, J.; Monson, R. K.

2009-12-01

88

Moose body mass variation revisited: disentangling effects of environmental conditions and genetics.  

PubMed

Large-scale geographical variation in phenotypic traits within species is often correlated to local environmental conditions and population density. Such phenotypic variation has recently been shown to also be influenced by genetic structuring of populations. In ungulates, large-scale geographical variation in phenotypic traits, such as body mass, has been related to environmental conditions and population density, but little is known about the genetic influences. Research on the genetic structure of moose suggests two distinct genetic lineages in Norway, structured along a north-south gradient. This corresponds with many environmental gradients, thus genetic structuring provides an additional factor affecting geographical phenotypic variation in Norwegian moose. We investigated if genetic structure explained geographical variation in body mass in Norwegian moose while accounting for environmental conditions, age and sex, and if it captured some of the variance in body mass that previously was attributed to environmental factors. Genetic structuring of moose was the most important variable in explaining the geographic variation in body mass within age and sex classes. Several environmental variables also had strong explanatory power, related to habitat diversity, environmental seasonality and winter harshness. The results suggest that environmental conditions, landscape characteristics, and genetic structure should be evaluated together when explaining large-scale patterns in phenotypic characters or life history traits. However, to better understand the role of genetic and environmental effects on phenotypic traits in moose, an extended individual-based study of variation in fitness-related characters is needed, preferably in an area of convergence between different genetic lineages. PMID:24091427

Herfindal, Ivar; Haanes, Hallvard; Solberg, Erling J; Røed, Knut H; Høgda, Kjell Arild; Sæther, Bernt-Erik

2014-02-01

89

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. PMID:25535557

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

90

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

91

Multiscale Effects of Management, Environmental Conditions, and Land Use on Nitrate Leaching in Dairy Farms  

Microsoft Academic Search

Nitrate leaching in intensive grassland- and silage maize-based dairy farming systems on sandy soil is a main environmental concern. Here, statistical relationships are presented between management practices and environmental conditions and nitrate concentration in shallow groundwater (0.8 m depth) at farm, field, and point scales in the Netherlands, based on data collected in a participatory approach over a 7-yr period

J. Oenema; S. L. G. E. Burgers; J. Verloop; A. Hooijboer; L. Boumans; Berge ten H. F. M

2010-01-01

92

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

93

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

94

Applications of remote sensing for the evaluation of Adriatic Sea environmental conditions  

SciTech Connect

The paper shows the remote sensing activities that ENEA is carrying out for the evaluation of Adriatic Sea environmental conditions and their modifications over the last fifteen years. The activities were requested by the Italian Research Ministry to gain knowledge of the circulation model of the Adriatic Sea and to understand what caused algae blooms in some of the last years. The Adriatic Sea is a high environmental risk sea, because its depth is low and a strong pollutant charge is coming into the sea from the Po river and from many other rivers of the NE coast of Italy. Processing of satellite images has covered the period from 1980 up to now and has allowed the reconstruction of modifications of the environmental conditions of the sea. The paper shows the first results obtained by remote sensing images processing that will be utilized for the database of the Adriatic Sea.

Vitiello, F.; Borfecchia, F.; De Cecco, L.; Martini, S. [ENEA, Rome (Italy)

1997-08-01

95

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

96

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 in Nantucket Sound, off the coast of Massachusetts. These data provide an excellent opportunity to investigate predictions of the `log law' model at this site. In the shallow, protected waters of Nantucket Sound, tidal

Massachusetts at Amherst, University of

97

Impacts of environmental conditions on the sorption of volatile organic compounds onto tire powder  

Microsoft Academic Search

A series of batch tests were performed and the impacts of environmental conditions and phase change on the sorption of volatile organic compounds (VOCs) were investigated. Benzene, trichloroethylene, tetrachloroethylene, and ethylbenzene were selected as target VOCs. Sorption of VOCs onto tire powder was well demonstrated by a linear-partitioning model. Water–tire partition coefficients of VOCs (not tested in this study) could

Dong I. Oh; Kyongphile Nam; Jae W. Park; Jee H. Khim; Yong K. Kim; Jae Y. Kim

2008-01-01

98

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

99

Regulation of free corticosterone and CBG capacity under different environmental conditions in altricial nestlings  

Microsoft Academic Search

The concentration of circulating glucocorticoids is regulated in response to environmental and endogenous conditions. Total circulating corticosterone, the main glucocorticoid in birds, consists of a fraction which is bound to corticosterone-binding globulins (CBG) and a free fraction. There is increasing evidence that the environment modulates free corticosterone levels through varying the concentration of CBG, but experimental evidence is lacking. To

Bettina Almasi; Alexandre Roulin; Susanne Jenni-Eiermann; Creagh W. Breuner; Lukas Jenni

2009-01-01

100

The intake curve for calcium into apple fruits under various environmental conditions  

Microsoft Academic Search

The effect of a few environmental factors on calcium intake into fruits was studied in potted trees (cv. Cox's Orange Pippin and Schone van Boskoop) kept under either fully controlled or outdoor conditions. Contrary to the usual pattern of orchard trees, the intake curve did not flatten after mid?July but showed a substantial increase which persisted until harvest. Only at

J. Tromp

1979-01-01

101

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

102

Species richness of both native and invasive aquatic plants influenced by environmental conditions and human activity  

Microsoft Academic Search

Invasive plants alter community structure, threatening ecosystem function and biodiversity, but little information is available on whether invasive species richness responds to environmental conditions in the same way that richness of native plants does. We surveyed submerged and floating-leaved plants in 99 Connecticut (northeast USA) lakes and ponds, collecting quantitative data on abundance and frequency. We used multiple linear and

Robert S. Capers; Roslyn Selsky; Gregory J. Bugbee; Jason C. White

2009-01-01

103

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

104

Environmental and genetic variation of soflavone content under Brazil growing conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

To examine and determine differences in isoflavone content among several Brazilian soybean cultivars grown in a range of locations and environmental conditions, 233 genotypes were evaluated and a range of 12 mg/100g (cv. Embrapa 48) to 461mg/100g (cv. CS 305) of total isoflavone content was observed...

105

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

Microsoft Academic Search

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

Inés Ibáñez; Eugene W. Schupp

2001-01-01

106

Speech synthesis reactive to dynamic noise environmental conditions Susana Palmaz Lopez-Pelaez1  

E-print Network

Speech synthesis reactive to dynamic noise environmental conditions Susana Palmaz L´opez-Pel´aez1 , Robert A. J. Clark Center for Speech Technology Research, The University of Edinburgh susana.palmaz@nuance.com, rob.clark@ed.ac.uk Abstract This paper addresses the issue of generating synthetic speech in changing

Edinburgh, University of

107

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.

108

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

109

Dietary CDP-Choline Supplementation Prevents Memory Impairment Caused by Impoverished Environmental Conditions in Rats  

ERIC Educational Resources Information Center

The authors previously showed that dietary cytidine (5')-diphosphocholine (CDP-choline) supplementation could protect against the development of memory deficits in aging rats. In the present study, younger rats exposed to impoverished environmental conditions and manifesting hippocampal-dependent memory impairments similar to those observed in the…

Teather, Lisa A.; Wurtman, Richard J.

2005-01-01

110

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...

111

BEHAVIORAL SENSITIZATION TO ETHANOL IS MODULATED BY ENVIRONMENTAL CONDITIONS, BUT IS NOT ASSOCIATED WITH  

E-print Network

BEHAVIORAL SENSITIZATION TO ETHANOL IS MODULATED BY ENVIRONMENTAL CONDITIONS, BUT IS NOT ASSOCIATED, OR 97239, USA Abstract--Rationale: The ability of ethanol to facilitate GABAA receptor-mediated transmission may result in GABAA receptor alterations during repeated ethanol administration, and lead

Das, Soma

112

Understanding the savanna dynamics in relation to rangeland management systems and environmental conditions in semi-arid Botswana   

E-print Network

This thesis investigates the effects of rangeland management systems on savanna ecosystems under different environmental conditions in Botswana, Southern Africa. The soil sampling and vegetation assessment were conducted ...

Kgosikoma, Olaotswe Ernest

2012-06-25

113

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

114

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

115

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

116

The effect of environmental conditions on expression of Bacteroides fragilis and Bacteroides thetaiotaomicron C10 protease genes  

PubMed Central

Background Bacteroides fragilis and Bacteroides thetaiotaomicron are members of the normal human intestinal microbiota. However, both organisms are capable of causing opportunistic infections, during which the environmental conditions to which the bacteria are exposed change dramatically. To further explore their potential for contributing to infection, we have characterized the expression in B. thetaiotaomicron of four homologues of the gene encoding the C10 cysteine protease SpeB, a potent extracellular virulence factor produced by Streptococcus pyogenes. Results We identified a paralogous set of genes (btp genes) in the B. thetaiotaomicron genome, that were related to C10 protease genes we recently identified in B. fragilis. Similar to C10 proteases found in B. fragilis, three of the B. thetaiotaomicron homologues were transcriptionally coupled to genes encoding small proteins that are similar in structural architecture to Staphostatins, protease inhibitors associated with Staphopains in Staphylococcus aureus. The expression of genes for these C10 proteases in both B. fragilis and B. thetaiotaomicron was found to be regulated by environmental stimuli, in particular by exposure to oxygen, which may be important for their contribution to the development of opportunistic infections. Conclusions Genes encoding C10 proteases are increasingly identified in operons which also contain genes encoding proteins homologous to protease inhibitors. The Bacteroides C10 protease gene expression levels are responsive to different environmental stimuli suggesting they may have distinct roles in the bacterial-host interaction. PMID:22943521

2012-01-01

117

Assessment of the environmental conditions of the Sarno river basin (south Italy): a stream sediment approach.  

PubMed

The Sarno river basin covers an area of 500 km(2) collecting the waters of Solofrana and Cavaiola tributaries. Originally it manly represents a source of livelihood for inhabitants by fishing and transporting goods; currently, the Sarno river, still partially used for irrigation, is affected by an extreme environmental degradation as a result of uncontrolled outflow of industrial waste. Within the framework of a wider geochemical prospecting project aiming at characterizing the whole territory of the Campania region, 89 stream sediment samples with a sampling density of 1 sample per 5 km(2) were collected in the river basin and analyzed by means of inductively coupled plasma-mass spectrometry in order to assess the environmental conditions at a regional scale. A GIS-aided technique, based on both the actual distribution of potentially harmful elements and their regional background values, was used to generate the maps of the contamination factors and of the contamination degrees for As, Cd, Cr, Cu, Hg, Pb and Zn. Furthermore, a factor analysis was performed to assess the nature and the extent of contamination sources for the river sediments. Results showed that the Sarno river basin could be divided in two "environmental status" units: one, low contaminated, corresponding to the hilly and mountain areas, and the second, from moderately to very highly contaminated, corresponding to the economically developed areas of the valley floor characterized by a high population density. This work was developed within a project that aims to investigate the relationships between environmental pollution and human health by analyzing environmental media (stream sediments, water, soil and vegetation) together with human hair of resident population. In this context, the spatial correlation between the extremely compromised environmental conditions of developed areas and the incidence rate of liver cancer in the same area was also explored posing the need of a careful costs/benefits analysis to assess whether the deterioration of the environment, that could adversely affect the conditions of public health, is worth the economic development. PMID:23053925

Albanese, Stefano; Iavazzo, Pietro; Adamo, Paola; Lima, Annamaria; De Vivo, Benedetto

2013-06-01

118

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

119

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

120

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. PMID:25691973

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

2015-01-01

121

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

PubMed

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. PMID:25691973

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

2015-01-01

122

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

NASA Astrophysics Data System (ADS)

Human 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

123

[Comparative analysis of the physical status of students living under different conditions of environmental pollution].  

PubMed

The physical status was comparatively studied in students living under different conditions of environmental pollution. The anthropometric and some physiometric (vital capacity) parameters were established to be lower in students from polluted areas than in those from relatively pure ones. The students from polluted areas were observed to have higher hemodynamic parameters (heart rate, stroke volume, cardiac output). The results of the study improve and supplement knowledge of the physical development of the students living in the areas with varying environmental pollution levels and reflect the morphofunctional status that is an indicator in the evaluation of the body's functional tension, which may suggest the suppressing action of environmental pollution on the students' body. PMID:20873272

Musalimova, R S; Valiakhmetov, R M

2010-01-01

124

Immune Activity, Body Condition and Human-Associated Environmental Impacts in a Wild Marine Mammal  

PubMed Central

Within individuals, immunity may compete with other life history traits for resources, such as energy and protein, and the damage caused by immunopathology can sometimes outweigh the protective benefits that immune responses confer. However, our understanding of the costs of immunity in the wild and how they relate to the myriad energetic demands on free-ranging organisms is limited. The endangered Galapagos sea lion (Zalophus wollebaeki) is threatened simultaneously by disease from domestic animals and rapid changes in food availability driven by unpredictable environmental variation. We made use of this unique ecology to investigate the relationship between changes in immune activity and changes in body condition. We found that during the first three months of life, changes in antibody concentration were negatively correlated with changes in mass per unit length, skinfold thickness and serum albumin concentration, but only in a sea lion colony exposed to anthropogenic environmental impacts. It has previously been shown that changes in antibody concentration during early Galapagos sea lion development were higher in a colony exposed to anthropogenic environmental impacts than in a control colony. This study allows for the possibility that these relatively large changes in antibody concentration are associated with negative impacts on fitness through an effect on body condition. Our findings suggest that energy availability and the degree of plasticity in immune investment may influence disease risk in natural populations synergistically, through a trade-off between investment in immunity and resistance to starvation. The relative benefits of such investments may change quickly and unpredictably, which allows for the possibility that individuals fine-tune their investment strategies in response to changes in environmental conditions. In addition, our results suggest that anthropogenic environmental impacts may impose subtle energetic costs on individuals, which could contribute to population declines, especially in times of energy shortage. PMID:23840603

Brock, Patrick M.; Hall, Ailsa J.; Goodman, Simon J.; Cruz, Marilyn; Acevedo-Whitehouse, Karina

2013-01-01

125

Microbial Forensics: Predicting Phenotypic Characteristics and Environmental Conditions from Large-Scale Gene Expression Profiles  

PubMed Central

A tantalizing question in cellular physiology is whether the cellular state and environmental conditions can be inferred by the expression signature of an organism. To investigate this relationship, we created an extensive normalized gene expression compendium for the bacterium Escherichia coli that was further enriched with meta-information through an iterative learning procedure. We then constructed an ensemble method to predict environmental and cellular state, including strain, growth phase, medium, oxygen level, antibiotic and carbon source presence. Results show that gene expression is an excellent predictor of environmental structure, with multi-class ensemble models achieving balanced accuracy between 70.0% (±3.5%) to 98.3% (±2.3%) for the various characteristics. Interestingly, this performance can be significantly boosted when environmental and strain characteristics are simultaneously considered, as a composite classifier that captures the inter-dependencies of three characteristics (medium, phase and strain) achieved 10.6% (±1.0%) higher performance than any individual models. Contrary to expectations, only 59% of the top informative genes were also identified as differentially expressed under the respective conditions. Functional analysis of the respective genetic signatures implicates a wide spectrum of Gene Ontology terms and KEGG pathways with condition-specific information content, including iron transport, transferases, and enterobactin synthesis. Further experimental phenotypic-to-genotypic mapping that we conducted for knock-out mutants argues for the information content of top-ranked genes. This work demonstrates the degree at which genome-scale transcriptional information can be predictive of latent, heterogeneous and seemingly disparate phenotypic and environmental characteristics, with far-reaching applications. PMID:25774498

Kim, Minseung; Zorraquino, Violeta; Tagkopoulos, Ilias

2015-01-01

126

Microbial forensics: predicting phenotypic characteristics and environmental conditions from large-scale gene expression profiles.  

PubMed

A tantalizing question in cellular physiology is whether the cellular state and environmental conditions can be inferred by the expression signature of an organism. To investigate this relationship, we created an extensive normalized gene expression compendium for the bacterium Escherichia coli that was further enriched with meta-information through an iterative learning procedure. We then constructed an ensemble method to predict environmental and cellular state, including strain, growth phase, medium, oxygen level, antibiotic and carbon source presence. Results show that gene expression is an excellent predictor of environmental structure, with multi-class ensemble models achieving balanced accuracy between 70.0% (±3.5%) to 98.3% (±2.3%) for the various characteristics. Interestingly, this performance can be significantly boosted when environmental and strain characteristics are simultaneously considered, as a composite classifier that captures the inter-dependencies of three characteristics (medium, phase and strain) achieved 10.6% (±1.0%) higher performance than any individual models. Contrary to expectations, only 59% of the top informative genes were also identified as differentially expressed under the respective conditions. Functional analysis of the respective genetic signatures implicates a wide spectrum of Gene Ontology terms and KEGG pathways with condition-specific information content, including iron transport, transferases, and enterobactin synthesis. Further experimental phenotypic-to-genotypic mapping that we conducted for knock-out mutants argues for the information content of top-ranked genes. This work demonstrates the degree at which genome-scale transcriptional information can be predictive of latent, heterogeneous and seemingly disparate phenotypic and environmental characteristics, with far-reaching applications. PMID:25774498

Kim, Minseung; Zorraquino, Violeta; Tagkopoulos, Ilias

2015-03-01

127

Environmental and mental conditions predicting the experience of involuntary musical imagery: An experience sampling method study.  

PubMed

An experience sampling method (ESM) study on 40 volunteers was conducted to explore the environmental factors and psychological conditions related to involuntary musical imagery (INMI) in everyday life. Participants reported 6 times per day for one week on their INMI experiences, relevant contextual information and associated environmental conditions. The resulting data was modeled with Bayesian networks and led to insights into the interplay of factors related to INMI experiences. The activity that a person is engaged was found to play an important role in the experience of mind wandering, which in turn enables the experience of INMI. INMI occurrence is independent of the time of the day while the INMI trigger affects the subjective evaluation of the INMI experience. The results are compared to findings from earlier studies based on retrospective surveys and questionnaires and highlight the advantage of ESM techniques in research on spontaneous experiences like INMI. PMID:25800098

Floridou, Georgia A; Müllensiefen, Daniel

2015-05-01

128

Environmental conditions influence allometric patterns in the blow fly, Chrysomya albiceps.  

PubMed

The objective of this research was to study variations in allometry of body characters in females and males of two populations of blow flies, Chrysomya albiceps (Wiedemann) (Diptera: Calliphoridae), under different environmental conditions to establish patterns of morphological variation. Body size of both males and females in the experimental population was significantly higher than in the individuals of the natural population, indicating an important influence of food on body size. All genitalic and non-genitalic characters in males and females of the two populations showed a trend towards negative allometry rather than isometry. Allometric patterns were modified in both sexes and between populations. The data show generally larger allometric slopes in females than in males. We confirmed that the environmental conditions have an important effect on allometric patterns and body size. PMID:22224467

Horenstein, M Battán; Peretti, A V

2011-01-01

129

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

PubMed

Concentrations and species of iodine isotopes ((127)I and (129)I) provide vital information about iodine geochemistry, environmental conditions and water masses exchange in oceans. Despite extensive investigations of anthropogenic (129)I 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 (129)I and (127)I, 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 (127)I and (129)I. Despite the rather constant ratios of (127)I(-)/(127)IO3(-), the (129)I(-)/(129)IO3(-) 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 (129)I 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

130

Effect of environmental conditions on the ?-glucosidase inhibitory activity of mulberry leaves.  

PubMed

Mulberry leaves have been used as the sole food for silkworms in sericulture, and also as a traditional medicine for diabetes prevention. Mulberry leaf components, for example 1-deoxynojirimycin (1-DNJ), inhibit the activity of ?-glucosidase and prevent increased blood glucose levels, and they are highly toxic to caterpillars other than silkworms. The ?-glucosidase inhibitory activity of mulberry leaves changes with the season, but it is unknown which environmental conditions influence the ?-glucosidase inhibitory activity. We investigated in this study the relationship between the ?-glucosidase inhibitory activity and environmental conditions of temperature and photoperiod. The results demonstrate that low temperatures induced decreasing ?-glucosidase inhibitory activity, while the induction of newly grown shoots by the scission of branches induced increasing ?-glucosidase inhibitory activity. These results suggest that the ?-glucosidase inhibitory activity was related to the defense mechanism of mulberry plants against insect herbivores. PMID:22146716

Nakanishi, Hiromitsu; Onose, Shinji; Kitahara, Eriko; Chumchuen, Sukunya; Takasaki, Midori; Konishi, Hajime; Kanekatsu, Rensuke

2011-01-01

131

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

132

Effect of environmental conditions on biological decolorization of textile dyestuff by C. versicolor  

Microsoft Academic Search

Effects of environmental conditions such as pH, media composition, carbon and nitrogen sources, TOC\\/N ratio, and dyestuff concentrations on decolorization of reactive phytalocyanin type textile dyestuff Everzol Turquoise Blue G by white rot fungi, Coriolus versicolor MUCL were investigated. pH = 4.5 and the media III were found to be the most suitable ones among the others tested. Compared to

Ilgi Karapinar Kapdan; Fikret Kargia; Geoffrey McMullan; Roger Marchant

2000-01-01

133

Dichromated pullulan diffraction gratings: influence of environmental conditions and storage time on their properties  

NASA Astrophysics Data System (ADS)

Investigations of the environmental stability of diffraction gratings, recorded in dichromated pullulan (DCP), are reported. Profile changes of DCP surface relief gratings, under high humidity conditions, were analyzed using an atomic force microscope. It was found that the profile was not altered, while the diffraction efficiency was preserved. The influence of storage life on the diffraction efficiency and surface profile of DCP gratings were also investigated. It was concluded that DCP gratings offer much better stability compared with the dichromated gelatin.

Savi? Ševi?, Svetlana; Panteli?, Dejan

2007-01-01

134

Innovations in energy efficient and environmentally friendly space-conditioning systems  

Microsoft Academic Search

This paper discusses several different approaches to increase the energy efficiency and decrease the environmental impact of space-conditioning systems. The use of microchannel components and hydronic coupling is presented as a method to drastically reduce the size and refrigerant inventories of the refrigerant-carrying components of vapor-compression heat pumps. Design aspects of heat pumps using carbon dioxide, a natural refrigerant with

Srinivas Garimella

2003-01-01

135

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

136

Effect of environmental deterioration on buildings: a condition assessment case study  

NASA Astrophysics Data System (ADS)

The deterioration of structures due to corrosion is probably the most significant factor for their damaging condition and the need for maintenance. Corrosion mechanisms depend on the environmental conditions and the geographic characteristics of the area. In this paper a condition assessment methodology is presented through an application on a deteriorated building in Cyprus. The methodology's starting point is the collection of information through Google Earth for classification of buildings in regions based on their environmental and geographic characteristics. Through this screening process, buildings in each defined region are selected for evaluation. The following steps of the methodology include testing on selected structural members for the estimation of the compression strength and the depth of carbonation. The results of the case study, are used from the responsible engineer to evaluate the current condition of the building regarding its structural integrity and the effect of corrosion. The testing data showed that the current building strength is lower than the code's requirements and that carbonation induced corrosion must be addressed to prevent further damage.

Christou, George; Tantele, Elia A.; Votsis, Renos A.

2014-08-01

137

Remodeling of Bacterial RNA Polymerase Supramolecular Complex in Response to Environmental Conditions  

SciTech Connect

Directed binding of RNA polymerase to distinct promoter elements controls transcription and promotes adaptive responses to changing environmental conditions. To identify proteins that modulate transcription, we have expressed a tagged alpha-subunit of RNA polymerase in Shewanella oneidensis under controlled growth conditions, isolated the protein complex using newly developed multiuse affinity probes, and used LC-MS/MS to identify proteins in the complex. Complementary fluorescence correlation spectroscopy measurements were used to determine the average size of the RNA polymerase complex in cellular lysates. We find that RNA polymerase exists as a large supramolecular complex with an apparent mass in excess of 1.4 MDa, whose protein composition substantially changes in response to growth conditions. Enzymes that copurify with RNA polymerase include those associated with tRNA processing, nucleotide metabolism, and energy biosynthesis, which we propose to be necessary for optimal transcriptional rates.

Verma, Seema; Xiong, Yijia; Mayer, M. Uljana; Squier, Thomas C.

2007-03-20

138

DEGRADATION OF FIBERBOARD IN MODEL 9975 PACKAGE FOLLOWING ENVIRONMENTAL CONDITIONING FIRST INTERIM REPORT  

SciTech Connect

Fiberboard material, used in the 9975 shipping package, has been tested for thermal, mechanical and physical properties following environmental conditioning for periods up to 64 weeks. The environments are either representative or bounding of KAMS storage conditions, in order to provide prediction of long-term performance of the 9975 package in KAMS. This report summarizes the data and analysis performed to date. These data show degradation of some properties in some of the environments, but samples have not degraded beyond identified minimum KAMS requirements. Statistical analysis of the data collected to date support the development of a model to predict a service life in KAMS. Further model development and lifetime predictions will be made following additional conditioning and testing in accordance with the task technical plan.

Daugherty, W; Stephen Harris, S

2007-06-13

139

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

140

Clothing insulation and temperature, layer and mass of clothing under comfortable environmental conditions  

PubMed Central

This study was designed to investigate the relationship between the microclimate temperature and clothing insulation (Icl) under comfortable environmental conditions. In total, 20 subjects (13 women, 7 men) took part in this study. Four environmental temperatures were chosen: 14°C (to represent March/April), 25°C (May/June), 29°C (July/August), and 23°C (September/October). Wind speed (0.14ms-1) and humidity (45%) were held constant. Clothing microclimate temperatures were measured at the chest (Tchest) and on the interscapular region (Tscapular). Clothing temperature of the innermost layer (Tinnermost) was measured on this layer 30 mm above the centre of the left breast. Subjects were free to choose the clothing that offered them thermal comfort under each environmental condition. We found the following results. 1) All clothing factors except the number of lower clothing layers (Llower), showed differences between the different environmental conditions (P<0.05). The ranges of Tchest were 31.6 to 33.5°C and 32.2 to 33.4°C in Tscapular. The range of Tinnermost was 28.6 to 32.0°C. The range of the upper clothing layers (Lupper) and total clothing mass (Mtotal) was 1.1 to 3.2 layers and 473 to 1659 g respectively. The range of Icl was 0.78 to 2.10 clo. 2) Post hoc analyses showed that analysis of Tinnermost produced the same results as for that of Icl. Likewise, the analysis of Lupper produced the same result as the analysis of the number of total layers (Ltotal) within an outfit. 3) Air temperature (ta) had positive relationships with Tchest and Tscapular and with Tinnermost but had inverse correlations with Icl, Mtotal, Lupper and Ltotal. Tchest, Tscapular, and Tinnermost increased as ta rose. 4) Icl had inverse relationships with Tchest and Tinnermost, but positive relationships with Mtotal, Lupper and Ltotal. Icl could be estimated by Mtotal, Lupper, and Tscapular using a multivariate linear regression model. 5) Lupper had positive relationships with Icl and Mtotal, but Llower did not. Subjects hardly changed Llower under environmental comfort conditions between March and October. This indicates that each of the Tchest, Mtotal, and Lupper was a factor in predicting Icl. Tinnermost might also be a more influential factor than the clothing microclimate temperature. PMID:23816370

2013-01-01

141

Bill E. Kunkle Interdisciplinary Beef Symposium: Animal welfare concerns for cattle exposed to adverse environmental conditions.  

PubMed

Increasing awareness of animal welfare has become a priority in food production systems involving animals. Under normal working environments, production practices are constantly evaluated to maintain optimum levels of animal well-being. However, during periods of adverse weather, optimum conditions for animal comfort, as well as animal performance, are often compromised. In the Midwest and Great Plains states, the heat waves of 1995, 1999, 2006, 2009, 2010, and 2013 were particularly difficult on animals reared in confinement, with documented cattle losses approaching 5,000 head each year. Additionally, during the summer of 2011, nearly 15,000 head of cattle across 5 states were lost as a result of heat stress. During prolonged periods of heat stress, lower conceptions rates are observed in livestock. In addition, animals reared in confinement buildings are often compromised because of limitations in ventilation systems. Under the opposite environmental spectrum, the winters of 1992 to 1993, 1996 to 1997, 1997 to 1998, 2006 to 2007, and 2008 to 2009 caused hardship for livestock producers, particularly for those rearing animals in an outdoor environment. During the winters of 1996 to 1997 and 2008 to 2009 up to 50% of the newborn calves were lost in many areas, with over 75,000 head of cattle lost in the northern plains states. Late fall and early winter snowstorms in 1992, 1997, 2006, and 2013 resulted in the loss of over 25,000 head of cattle each year in the Great Plains region of the United States. Economic losses from reduced performance of cattle experiencing severe environmental stress likely exceed losses associated with livestock death by 5- to 10-fold. Use of alternative supplementation programs may need to be considered for livestock challenged by adverse environmental conditions. Use of additional water for consumption and cooling, shade, and/or alternative management strategies need to be considered to help livestock cope with heat stress. For animals reared outside during the winter, strategies that increase animal space and environmental buffers need to be employed to minimize effects of mud, wet conditions, and wind chill. The above-mentioned weather events suggest that there are ample opportunities for livestock producers to enhance animal welfare and minimize impact of environmental stress. Caretakers need a greater understanding of animal responses to weather challenges to help animals cope with adverse climatic conditions. PMID:25414102

Mader, T L

2014-12-01

142

Identifying the environmental conditions favouring west nile virus outbreaks in europe.  

PubMed

West Nile Virus (WNV) is a globally important mosquito borne virus, with significant implications for human and animal health. The emergence and spread of new lineages, and increased pathogenicity, is the cause of escalating public health concern. Pinpointing the environmental conditions that favour WNV circulation and transmission to humans is challenging, due both to the complexity of its biological cycle, and the under-diagnosis and reporting of epidemiological data. Here, we used remote sensing and GIS to enable collation of multiple types of environmental data over a continental spatial scale, in order to model annual West Nile Fever (WNF) incidence across Europe and neighbouring countries. Multi-model selection and inference were used to gain a consensus from multiple linear mixed models. Climate and landscape were key predictors of WNF outbreaks (specifically, high precipitation in late winter/early spring, high summer temperatures, summer drought, occurrence of irrigated croplands and highly fragmented forests). Identification of the environmental conditions associated with WNF outbreaks is key to enabling public health bodies to properly focus surveillance and mitigation of West Nile virus impact, but more work needs to be done to enable accurate predictions of WNF risk. PMID:25803814

Marcantonio, Matteo; Rizzoli, Annapaola; Metz, Markus; Rosà, Roberto; Marini, Giovanni; Chadwick, Elizabeth; Neteler, Markus

2015-01-01

143

Identifying the Environmental Conditions Favouring West Nile Virus Outbreaks in Europe  

PubMed Central

West Nile Virus (WNV) is a globally important mosquito borne virus, with significant implications for human and animal health. The emergence and spread of new lineages, and increased pathogenicity, is the cause of escalating public health concern. Pinpointing the environmental conditions that favour WNV circulation and transmission to humans is challenging, due both to the complexity of its biological cycle, and the under-diagnosis and reporting of epidemiological data. Here, we used remote sensing and GIS to enable collation of multiple types of environmental data over a continental spatial scale, in order to model annual West Nile Fever (WNF) incidence across Europe and neighbouring countries. Multi-model selection and inference were used to gain a consensus from multiple linear mixed models. Climate and landscape were key predictors of WNF outbreaks (specifically, high precipitation in late winter/early spring, high summer temperatures, summer drought, occurrence of irrigated croplands and highly fragmented forests). Identification of the environmental conditions associated with WNF outbreaks is key to enabling public health bodies to properly focus surveillance and mitigation of West Nile virus impact, but more work needs to be done to enable accurate predictions of WNF risk. PMID:25803814

Metz, Markus; Rosà, Roberto; Marini, Giovanni; Chadwick, Elizabeth; Neteler, Markus

2015-01-01

144

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

145

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

146

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

147

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

148

[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

149

Water retention of selected microorganisms and Martian soil simulants under close to Martian environmental conditions  

NASA Astrophysics Data System (ADS)

Based on the latest knowledge about microorganisms resistant towards extreme conditions on Earth and results of new complex models on the development of the Martian atmosphere we quantitatively examined the water-bearing properties of selected extremophiles and simulated Martian regolith components and their interaction with water vapor under close to Martian environmental conditions. Three different species of microorganisms have been chosen and prepared for our study: Deinococcus geothermalis, Leptothrix sp. OT_B_406, and Xanthoria elegans. Further, two mineral mixtures representing the early and the late Martian surface as well as montmorillonite as a single component of phyllosilicatic minerals, typical for the Noachian period on Mars, were selected. The thermal mass loss of the minerals and bacteria-samples was measured by thermoanalysis. The hydration and dehydration properties were determined under close to Martian environmental conditions by sorption isotherm measurements using a McBain-Bakr quartz spring balance. It was possible to determine the total water content of the materials as well as the reversibly bound water fraction as function of the atmospheres humidity by means of these methods. Our results are important for the evaluation of future space mission outcomes including astrobiological aspects and can support the modeling of the atmosphere/surface interaction by showing the influence on the water inventory of the upper most layer of the Martian surface.

Jänchen, J.; Bauermeister, A.; Feyh, N.; de Vera, J.-P.; Rettberg, P.; Flemming, H.-C.; Szewzyk, U.

2014-08-01

150

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

151

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

152

Environmental hypoxia but not minor shell damage affects scope for growth and body condition in the blue mussel Mytilus edulis (L.).  

PubMed

The effects of short-term (7 d) exposure to environmental hypoxia (2.11 mg O? L?¹; control: 6.96 mg O? L?¹) and varying degrees of shell damage (1 or 2, 1 mm diameter holes; control: no holes) on respiration rate, clearance rate, ammonia excretion rate, scope for growth (SFG) and body condition index were investigated in adult blue mussels (Mytilus edulis). There was a significant hypoxia-related reduction in SFG (>6.70 to 0.92 J g?¹ h?¹) primarily due to a reduction in energy acquisition as a result of reduced clearance rates during hypoxia. Shell damage had no significant affect on any of the physiological processes measured or the SFG calculated. Body condition was unaffected by hypoxia or shell damage. In conclusion, minor physical damage to mussels had no effect on physiological energetics but environmental hypoxia compromised growth, respiration and energy acquisition presumably by reducing feeding rates. PMID:24485768

Sanders, Trystan; Widdicombe, Steve; Calder-Potts, Ruth; Spicer, John I

2014-04-01

153

Evaluation of natural colonisation of cementitious materials: Effect of bioreceptivity and environmental conditions.  

PubMed

Incorporation of living organisms, such as photosynthetic organisms, on the structure envelope has become a priority in the area of architecture and construction due to aesthetical, economic and ecological advantages. Important research efforts are made to achieve further improvements, such as for the development of cementitious materials with an enhanced bioreceptivity to stimulate biological growth. Previously, the study of the bioreceptivity of cementitious materials has been carried out mainly under laboratory conditions although field-scale experiments may present different results. This work aims at analysing the colonisation of cementitious materials with different levels of bioreceptivity by placing them in three different environmental conditions. Specimens did not present visual colonisation, which indicates that environmental conditions have a greater impact than intrinsic properties of the material at this stage. Therefore, it appears that in addition to an optimized bioreceptivity of the concrete (i.e., composition, porosity and roughness), extra measures are indispensable for a rapid development of biological growth on concrete surfaces. An analysis of the colonisation in terms of genus and quantity of the most representative microorganisms found on the specimens for each location was carried out and related to weather conditions, such as monthly average temperature and total precipitation, and air quality in terms of NOx, SO2, CO and O3. OPC-based specimens presented a higher colonisation regarding both biodiversity and quantity. However, results obtained in a previous experimental programme under laboratory conditions suggested a higher suitability of Magnesium Phosphate Cement-based (MPC-based) specimens for algal growth. Consequently, carefully considering the environment and the relationships between the different organisms present in an environment is vital for successfully using a cementitious material as a substrate for biological growth. PMID:25644840

Manso, Sandra; Calvo-Torras, María Ángeles; De Belie, Nele; Segura, Ignacio; Aguado, Antonio

2015-04-15

154

Use of response surface methodology to optimise environmental stress conditions on1 Penicillium glabrum, a food spoilage mould2  

E-print Network

Use of response surface methodology to optimise environmental stress conditions on1 Penicillium stress19 responses, appropriate experimental stress conditions must be precisely defined. Penicillium20-optimal conditions.32 33 Keywords: Penicillium glabrum, food spoilage, thermal shock, acid shock, alkali shock

Paris-Sud XI, Université de

155

Responses of five Mediterranean halophytes to seasonal changes in environmental conditions  

PubMed Central

In their natural habitats, different mechanisms may contribute to the tolerance of halophytes to high soil salinity and other abiotic stresses, but their relative contribution and ecological relevance, for a given species, remain largely unknown. We studied the responses to changing environmental conditions of five halophytes (Sarcocornia fruticosa, Inula crithmoides, Plantago crassifolia, Juncus maritimus and J. acutus) in a Mediterranean salt marsh, from summer 2009 to autumn 2010. A principal component analysis was used to correlate soil and climatic data with changes in the plants' contents of chemical markers associated with stress responses: ions, osmolytes, malondialdehyde (MDA, a marker of oxidative stress) and antioxidant systems. Stress tolerance in S. fruticosa, I. crithmoides and P. crassifolia (all succulent dicots) seemed to depend mostly on the transport of ions to aerial parts and the biosynthesis of specific osmolytes, whereas both Juncus species (monocots) were able to avoid accumulation of toxic ions, maintaining relatively high K+/Na+ ratios. For the most salt-tolerant taxa (S. fruticosa and I. crithmoides), seasonal variations of Na+, Cl?, K+ and glycine betaine, their major osmolyte, did not correlate with environmental parameters associated with salt or water stress, suggesting that their tolerance mechanisms are constitutive and relatively independent of external conditions, although they could be mediated by changes in the subcellular compartmentalization of ions and compatible osmolytes. Proline levels were too low in all the species to possibly have any effect on osmotic adjustment. However—except for P. crassifolia—proline may play a role in stress tolerance based on its ‘osmoprotectant’ functions. No correlation was observed between the degree of environmental stress and the levels of MDA or enzymatic and non-enzymatic antioxidants, indicating that the investigated halophytes are not subjected to oxidative stress under natural conditions and do not, therefore, need to activate antioxidant defence mechanisms. PMID:25139768

Gil, Ricardo; Bautista, Inmaculada; Boscaiu, Monica; Lidón, Antonio; Wankhade, Shantanu; Sánchez, Héctor; Llinares, Josep; Vicente, Oscar

2014-01-01

156

Responses of five Mediterranean halophytes to seasonal changes in environmental conditions.  

PubMed

In their natural habitats, different mechanisms may contribute to the tolerance of halophytes to high soil salinity and other abiotic stresses, but their relative contribution and ecological relevance, for a given species, remain largely unknown. We studied the responses to changing environmental conditions of five halophytes (Sarcocornia fruticosa, Inula crithmoides, Plantago crassifolia, Juncus maritimus and J. acutus) in a Mediterranean salt marsh, from summer 2009 to autumn 2010. A principal component analysis was used to correlate soil and climatic data with changes in the plants' contents of chemical markers associated with stress responses: ions, osmolytes, malondialdehyde (MDA, a marker of oxidative stress) and antioxidant systems. Stress tolerance in S. fruticosa, I. crithmoides and P. crassifolia (all succulent dicots) seemed to depend mostly on the transport of ions to aerial parts and the biosynthesis of specific osmolytes, whereas both Juncus species (monocots) were able to avoid accumulation of toxic ions, maintaining relatively high K(+)/Na(+) ratios. For the most salt-tolerant taxa (S. fruticosa and I. crithmoides), seasonal variations of Na(+), Cl(-), K(+) and glycine betaine, their major osmolyte, did not correlate with environmental parameters associated with salt or water stress, suggesting that their tolerance mechanisms are constitutive and relatively independent of external conditions, although they could be mediated by changes in the subcellular compartmentalization of ions and compatible osmolytes. Proline levels were too low in all the species to possibly have any effect on osmotic adjustment. However-except for P. crassifolia-proline may play a role in stress tolerance based on its 'osmoprotectant' functions. No correlation was observed between the degree of environmental stress and the levels of MDA or enzymatic and non-enzymatic antioxidants, indicating that the investigated halophytes are not subjected to oxidative stress under natural conditions and do not, therefore, need to activate antioxidant defence mechanisms. PMID:25139768

Gil, Ricardo; Bautista, Inmaculada; Boscaiu, Monica; Lidón, Antonio; Wankhade, Shantanu; Sánchez, Héctor; Llinares, Josep; Vicente, Oscar

2014-01-01

157

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

158

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

159

Tick community composition in Midwestern US habitats in relation to sampling method and environmental conditions.  

PubMed

The ranges of many tick species are changing due to climate change and human alteration of the landscape. Understanding tick responses to environmental conditions and how sampling method influences measurement of tick communities will improve our assessment of human disease risk. We compared tick sampling by three collection methods (dragging, CO2 trapping and rodent surveys) in adjacent forested and grassland habitats in the lower Midwest, USA, and analyzed the relationship between tick abundance and microclimate conditions. The study areas were within the overlapping ranges of three tick species, which may provide conditions for pathogen exchange and spread into new vectors. Dermacentor variabilis (American dog tick) was found using all methods, Amblyomma americanum (lonestar tick) was found by dragging and CO2 trapping and Ixodes scapularis (blacklegged deer tick) was found only on rodents. Proportion of each species differed significantly among sampling methods. More ticks were found in forests compared to open habitats. Further, more ticks were collected by dragging and from rodents in hotter, drier conditions. Our results demonstrate that multiple sampling methodologies better measure the tick community and that microclimate conditions strongly influence the abundance and activity of individual tick species. PMID:24705853

Rynkiewicz, Evelyn C; Clay, Keith

2014-09-01

160

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

PubMed

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

161

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

162

Conclusion: An End Is a Beginning  

Microsoft Academic Search

\\u000a For pragmatic philosophy, what seems like a conclusion is really only a new beginning: the consummation of what has preceded\\u000a provides only a momentary platform for dealing with the ever-changing needs of the present. Thus, knowledge is always temporal,\\u000a wed to the particular conditions under which it is gained and to which it is applied and, accordingly, is temporary, awaiting

Thomas A. Regelski

163

Nonlinear Dielectric Properties of Yeast Cells Cultured in Different Environmental Conditions  

NASA Astrophysics Data System (ADS)

The harmonics of the electric current through yeast suspensions, the nonlinear dielectric properties of yeast cells, have particular patterns according to the biological activity of the cells and the measurement of these patterns is a technique for determining the activity of living cells. The concentration of glucose and oxygen in yeast culture medium influences the manifestation of fermentation or respiration of yeast cells. Measurements were made with yeast cells (Saccharomyces cerevisiae) cultured aerobically and anaerobically in sufficient glucose concentration, aerobic fermentation and anaerobic fermentation, and aerobically in limited glucose concentration, respiration. The results showed that the harmonics were barely apparent for yeast cells in aerobic fermentation and respiratory; however, cells in the anaerobic fermentation displayed substantial third and fifth harmonics. We can say that environmental condition affects the yeast cells' nonlinear properties, from another viewpoint, the measurements of the nonlinear properties are available to determine the activity of yeast cells adjusted to the conditions of their cultivation.

Kawanishi, Gomon; Fukuda, Naoki; Muraji, Masafumi

164

Metabolic and Environmental Conditions Determine Nuclear Genomic Instability in Budding Yeast Lacking Mitochondrial DNA  

PubMed Central

Mitochondrial dysfunctions are an internal cause of nuclear genome instability. Because mitochondria are key regulators of cellular metabolism, we have investigated a potential link between external growth conditions and nuclear chromosome instability in cells with mitochondrial defects. Using Saccharomyces cerevisiae, we found that cells lacking mitochondrial DNA (rho0 cells) have a unique feature, with nuclear chromosome instability that occurs in nondividing cells and strongly fluctuates depending on the cellular environment. Calorie restriction, lower growth temperatures, growth at alkaline pH, antioxidants (NAC, Tiron), or presence of nearby wild-type cells all efficiently stabilize nuclear genomes of rho0 cells, whereas high glucose and ethanol boost instability. In contrast, other respiratory mutants that still possess mitochondrial DNA (RHO+) keep fairly constant instability rates under the same growth conditions, like wild-type or other RHO+ controls. Our data identify mitochondrial defects as an important driver of nuclear genome instability influenced by environmental factors. PMID:24374640

Dirick, Léon; Bendris, Walid; Loubiere, Vincent; Gostan, Thierry; Gueydon, Elisabeth; Schwob, Etienne

2014-01-01

165

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

166

Environmental conditions and pathogen removal in macrophyte- and algal-based domestic wastewater treatment systems.  

PubMed

The environmental conditions and pathogen removal in macrophyte (Pistia stratiotes and Lemna paucicostata) and algal-based wastewater treatment systems were determined over a period of 29 days under tropical conditions. The experiment was conducted on a batch scale in 4.5 plastic containers immersed in moist sand beds. A control of raw sewage stored under dark conditions was included. Environmental conditions such as pH, temperature DO and conductivity and heterotrophic and faecal enterococci populations were monitored five times a week at 8, 12 and 20 GMT. BOD was monitored once a week for five weeks. Average temperatures within the systems ranged between 28.3 degrees C in the control to 30.6 degrees C in the algal-based system. Low pH levels of pH of 4.5 and DO levels of 3 mg/L were recorded in the water lettuce treatment systems. High pH levels around 10.5 and DO levels of about 20 mg/L were observed in the algal-based system. The control and duckweed system remained neutral. All treatment systems performed equally well in pathogen removal and BOD reduction. The BOD decreased from 130 mg/L to 5.0, 7.5, 10 and 15 mg/L in the duckweed, water lettuce, control and algal based treatment systems respectively. The faecal enterococci population decreased from 1.18 x 10(5) /ml to values below 100/ml in all treatment systems. PMID:11700649

Awuah, E; Anohene, F; Asante, K; Lubberding, H; Gijzen, H

2001-01-01

167

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 (a(W)), 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; Vergara, L Díaz; Aminahuel, C; Pereyra, C; Pena, G; Torres, A; Dalcero, A; Cavaglieri, L

2015-01-01

168

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

169

Response of the Toxic Dinoflagellate Karenia brevis to Current and Projected Environmental Conditions: Salinity and Global Climate Change  

E-print Network

of brevetoxins are needed to induce toxicity and environmental conditions appear to have the most direct impact on the cellular content of these toxins. A better understanding of K. brevis biology is essential to understand the mechanisms underlying toxin...

Errera, Reagan Michelle

2013-05-03

170

Quantitative genetics of larval life-history traits in Rana temporaria in different environmental conditions.  

PubMed

The degree to which genetic variation in a given trait varies among different populations of the same species and across different environments has seldom been quantified in wild vertebrate species. We investigated the expression of genetic variability and maternal effects in three larval life-history traits of the amphibian Rana temporaria. In a factorial laboratory experiment, five widely separated populations (max. 1600 km) were subjected to two different environmental treatments. Animal model analyses revealed that all traits were heritable (h(2) approximately 0.20) in all populations and under most treatment combinations. Although the cross-food treatment genetic correlations were close to unity, heritabilities under a restricted food regime tended to be lower than those under an ad libitum food regime. Likewise, maternal effects (m(2) approximately 0.05) were detected in most traits, and they tended to be most pronounced under restricted food conditions. We detected several cross-temperature genetic and maternal effects correlations that were lower than unity, suggesting that genotype-environment interactions and maternal effect-environment interactions are a significant source of phenotypic variation. The results reinforce the perspective that although the expression of genetic and maternal effects may be relatively homogeneous across different populations of the same species, local variation in environmental conditions can lead to significant variation in phenotypic expression of quantitative traits through genotype-environment and maternal effect-environment interactions. PMID:16454857

Laugen, Ane T; Kruuk, Loeske E B; Laurila, Anssi; Räsänen, Katja; Stone, Jonathan; Merilä, Juha

2005-12-01

171

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

172

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

PubMed

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

2012-03-01

173

Using Magnetically Responsive Tea Waste to Remove Lead in Waters under Environmentally Relevant Conditions  

PubMed Central

We report the use of a simple yet highly effective magnetite-waste tea composite to remove lead(II) (Pb2+) ions from water. Magnetite-waste tea composites were dispersed in four different types of water–deionized (DI), artificial rainwater, artificial groundwater and artificial freshwater–that mimic actual environmental conditions. The water samples had varying initial concentrations (0.16–5.55 ppm) of Pb2+ ions and were mixed with the magnetite-waste tea composite for at least 24 hours to allow adsorption of the Pb2+ ions to reach equilibrium. The magnetite-waste tea composites were stable in all the water samples for at least 3 months and could be easily removed from the aqueous media via the use of permanent magnets. We detected no significant leaching of iron (Fe) ions into the water from the magnetite-waste tea composites. The percentage of Pb adsorbed onto the magnetite-waste tea composite ranged from ?70% to 100%; the composites were as effective as activated carbon (AC) in removing the Pb2+ ions from water, depending on the initial Pb concentration. Our prepared magnetite-waste tea composites show promise as a green, inexpensive and highly effective sorbent for removal of Pb in water under environmentally realistic conditions. PMID:23818955

Yeo, Siang Yee; Choi, Siwon; Dien, Vivian; Sow-Peh, Yoke Keow; Qi, Genggeng; Hatton, T. Alan; Doyle, Patrick S.; Thio, Beng Joo Reginald

2013-01-01

174

Environmental conditions associated with lesions in introduced free-ranging sheep in Hawai‘i  

USGS Publications Warehouse

Wildlife species which have been translocated between temperate and tropical regions of the world provide unique opportunities to understand how disease processes may be affected by environmental conditions. European mouflon sheep (Ovis gmelini musimon) from the Mediterranean Islands were introduced to the Hawaiian Islands for sport hunting beginning in 1954 and were subsequently hybridized with feral domestic sheep (O. aries), which had been introduced in 1793. Three isolated mouflon populations have become established in the Hawaiian Islands but diseases in these populations have been little studied. The objective of this study was to evaluate and compare gross and histologic lesions in respiratory, renal, and hepatic systems of free-ranging sheep in two isolated volcanic environments on Hawai‘i Island. Tissue and fecal samples were collected in conjunction with population reductions during February 2011. We found gross or histologic evidence of lungworm infection in 44/49 sheep from Mauna Loa which were exposed to gaseous emissions from K?lauea Volcano. In contrast, only 7/50 sheep from Mauna Kea had lesions consistent with lungworm, but Mauna Kea sheep had significantly more upper respiratory tract inflammation and hyperplasia consistent with chronic antigenic stimulation, possibly associated with exposure to fine airborne particulates during extended drought conditions. We hypothesize that gasses from K?lauea Volcano contributed to severity of respiratory disease principally associated with chronic lungworm infections at Mauna Loa; however, there were numerous other potentially confounding environmental factors and interactions that merit further investigation.

Powers, Jenny G.; Duncan, Colleen G.; Spraker, Terry R.; Schuler, Bridget A.; Hess, Steven C.; Faford, Jonathan K.J.; Sin, Hans

2014-01-01

175

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

176

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

177

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

178

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

179

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

180

Functional traits of selected mangrove species in Brazil as biological indicators of different environmental conditions.  

PubMed

Ecological studies on phenotypic plasticity illustrate the relevance of this phenomenon in nature. Conditions of biota reflect environmental changes, highlighting the adaptability of resident species that can be used as bioindicators of such changes. We report the morpho-anatomical plasticity of leaves of Avicennia schaueriana Stapf & Leechm. ex Moldenke, Laguncularia racemosa (L.) C.F.Gaertn. and Rhizophora mangle L., evaluated in three estuaries (Vitória bay, Santa Cruz and Itaúnas River; state of Espírito Santo, Brazil), considering five areas of mangrove ecosystems with diverse environmental issues. Two sampling sites are part of the Ecological Station Lameirão Island in Vitória bay, close to a harbor. A third sampling site in Cariacica (Vitória bay) is inside the Vitória harbor and also is influenced by domestic sewage. The fourth studied area (Santa Cruz) is part of Piraquê Mangrove Ecological Reservation, while the fifth (Itaúnas River) is a small mangrove, with sandy sediment and greater photosynthetically active radiation, also not strongly influenced by anthropic activity. Results pointed out the morpho-anatomical plasticity in studied species, showing that A. schaueriana and L. racemosa might be considered the most appropriate bioindicators to indicate different settings and environmental conditions. Particularly, the dry mass per leaf area (LMA) of A. schaueriana was the main biomarker measured. In our study, LMA of A. schaueriana was positively correlated with salinity (Spearman 0.71), Mn content (0.81) and pH (0.82) but negatively correlated with phosphorus content (-0.63). Thus, the evaluation of modification in LMA of A. schaueriana pointed out changes among five studied sites, suggesting its use to reflect changes in the environment, which could be also useful in the future to evaluate the climate change. PMID:24496023

Arrivabene, Hiulana Pereira; Souza, Iara; Có, Walter Luiz Oliveira; Rodella, Roberto Antônio; Wunderlin, Daniel Alberto; Milanez, Camilla Rozindo

2014-04-01

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

Defining life: synthesis and conclusions.  

PubMed

The first part of the paper offers philosophical landmarks on the general issue of defining life. Section 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. Section 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. Section 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 (Section 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. Section 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. Section 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. PMID:20162362

Gayon, Jean

2010-04-01

183

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

184

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

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

185

Arsenic(III) methylation in betaine-nontronite clay-water suspensions under environmental conditions.  

PubMed

This paper reports arsenic methylation in betaine-nontronite clay-water suspensions under environmental conditions. Two nontronites (<0.05 mm), NAu-1 (green color, Al-enriched) and NAu-2 (brown color, Al-poor, contains tetrahedral Fe) from Uley Mine - South Australia were selected for this study. Betaine (pK(a)=1.83) was selected as methyl donor. The reaction between 5 g L(-1) clay, 20 ppm As(III), and 0.4M betaine at 7< or =pH(0)< or =9 under anoxic conditions was studied. The presence of nontronite clays were found to favor As(III) conversion to monomethylarsenic (MMA). Arsenic conversion was found to be as high as 50.2 ng MMA/ng As(III)(0). Conversion of As was found to be more quantitative in the presence of NAu-2 ((Na(0.72)) [Si(7.55) Al(0.16)Fe(0.29)][Al(0.34) Fe(3.54) Mg(0.05)] O(20)(OH)(4)) than NAu-1 ((Na(1.05)) [Si(6.98) Al(0.95)Fe(0.07)][Al(0.36) Fe(3.61) Mg(0.04)] O(20)(OH)(4)). The inherent negative charge at the nontronite tetrahedral layer stabilizes positively charged organic intermediate-reaction species, thereby leading to decreases in the overall methylation activation energy. The outcome of this work shows that nontronite clays catalyze As methylation to MMA via non-enzymatic pathway(s) under environmental conditions. PMID:20189716

Cervini-Silva, Javiera; Hernández-Pineda, Jessica; Rivas-Valdés, María Teresa; Cornejo-Garrido, Hilda; Guzmán, José; Fernández-Lomelín, Pilar; Del Razo, Luz Maria

2010-06-15

186

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

187

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

188

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

189

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

Code of Federal Regulations, 2010 CFR

...specific driving cycle. The environmental facility control elements...The recommended minimum environmental exhaust emission test...blower in box” technology as an acceptable simulation of environmental air flow cooling...

2010-07-01

190

Fourwing saltbush (Atriplex canescens (Pursh) Nutt. ) germination and establishment under arid environmental conditions of Saudi Arabia  

SciTech Connect

The objectives of this study were to conduct an autecological investigation of fourwing saltbush (Atriplex canescens (Pursh) Nutt.) in the Al-Gassim region of Saudi Arabia, upon which range rehabilitation could be based. Germination, seedling, transplanting, and water relation characteristics of the species under controlled and field conditions were determined. Most of the field work was conducted at plain and sand dune areas of the Al-Gassim, Saudi Arabia, and supplemented with growth chamber experiments. Seeds of tetrapolid and diploid forms, native to the United States, were introduced to Saudi Arabia, and their performance was determined. The Al-Gassim soil and climatic features were analyzed. Laboratory and field tests proved that fourwing saltbush was able to become established under and tolerate wide ranges of soil and harsh climatic conditions as found in the Al-Gassim. The best temperature range for germination was 15 to 35 C. High salinity in the soil of the plains area was found to be the only soil character that slightly decreased seedling growth, but germination and survival behaviors were not affected. The adaptation to extreme environmental conditions coupled with its known high nutritional forage values makes fourwing saltbush a valuable range plant in the arid regions of Saudi Arabia. As demand on rangeland increases, improved forage plants must have drough and salinity resistance mechanisms, and improved range management techniques should be used to achieve optimum returns.

Al-Hedaithy, S.S.M.

1983-01-01

191

Evaluating environmental joint extremes for the offshore industry using the conditional extremes model  

NASA Astrophysics Data System (ADS)

Understanding extreme ocean environments and their interaction with fixed and floating structures is critical for the design of offshore and coastal facilities. The joint effect of various ocean variables on extreme responses of offshore structures is fundamental in determining the design loads. For example, it is known that mean values of wave periods tend to increase with increasing storm intensity, and a floating system responds in a complex way to both variables. Specification of joint extremes in design criteria has often been somewhat ad hoc, being based on fairly arbitrary combinations of extremes of variables estimated independently. Such approaches are even outlined in design guidelines. Mathematically more consistent estimates of the joint occurrence of extreme environmental variables fall into two camps in the offshore industry - response-based and response-independent. Both are outlined here, with emphasis on response-independent methods, particularly those based on the conditional extremes model recently introduced by (Heffernan and Tawn, 2004), which has a solid theoretical motivation. We illustrate an application of the conditional extremes model to joint estimation of extreme storm peak significant wave height and peak period at a northern North Sea location, incorporating storm direction as a model covariate. We also discuss joint estimation of extreme current profiles with depth off the North West Shelf of Australia. Methods such as the conditional extremes model provide valuable additions to the metocean engineer's toolkit.

Ewans, Kevin; Jonathan, Philip

2014-02-01

192

Purdue AgronomyPurdue AgronomyCROP, SOIL, AND ENVIRONMENTAL SCIENCES Septic Systems in Flooded and Wet Soil Conditions  

E-print Network

) prior to reaching the water table. (b) Under high water table or flood conditions, however, the soil Systems in Flooded and Wet Soil Conditions--HENV-10-W How to Prepare for a Flood If flooding appearsPurdue AgronomyPurdue AgronomyCROP, SOIL, AND ENVIRONMENTAL SCIENCES Septic Systems in Flooded

Holland, Jeffrey

193

Imprint of past and present environmental conditions on microbiology and biogeochemistry of coastal Quaternary sediments  

NASA Astrophysics Data System (ADS)

To date, North Sea tidal-flat sediments have been intensively studied down to a depth of 5 m below seafloor (mbsf). However, little is known about the biogeochemistry, microbial abundance, and activity of sulfate reducers as well as methanogens in deeper layers. In this study, two 20 m-long cores were retrieved from the tidal-flat area of Spiekeroog Island, NW Germany. The drill sites were selected with a close distance of 900 m allowing to compare two depositional settings: first, a paleo-channel filled with Holocene sediments and second, a mainly Pleistocene sedimentary succession. Analyzing these cores, we wanted to test to which degree the paleo-environmental imprint is superimposed by present processes. In general, the numbers of bacterial 16S rRNA genes are one to two orders of magnitude higher than those of Archaea. The abundances of key genes for sulfate reduction and methanogenesis (dsrA and mcrA) correspond to the sulfate and methane profiles. A co-variance of these key genes at sulfate-methane interfaces and enhanced ex situ AOM rates suggest that anaerobic oxidation of methane may occur in these layers. Microbial and biogeochemical profiles are vertically stretched relative to 5 m-deep cores from shallower sediments in the same study area, but still appear compressed compared to deep sea sediments. Our interdisciplinary analysis shows that the microbial abundances and metabolic rates are elevated in the Holocene compared to Pleistocene sediments. However, this is mainly due to present environmental conditions such as pore water flow and organic matter availability. The paleo-environmental imprint is still visible but superimposed by these processes.

Beck, M.; Riedel, T.; Graue, J.; Köster, J.; Kowalski, N.; Wu, C. S.; Wegener, G.; Lipsewers, Y.; Freund, H.; Böttcher, M. E.; Brumsack, H.-J.; Cypionka, H.; Rullkötter, J.; Engelen, B.

2011-01-01

194

[Mathematical modeling to assess the effects of organic waste dumping on sanitary conditions of environmental waters].  

PubMed

This article provides an overview of emerging trends in environmental approaches to wastewater management in the developing world. Organic matter present in wastewater is one of the main sources of water pollution. In large amounts it can increase the number of microorganisms and thus the excessive consumption of dissolved oxygen in the metabolic processes of its utilization and stabilization, leading to the disappearance and extinction of aerobic organisms, favoring the appearance of other life forms in anaerobic conditions, often producing toxic residues. The main focus of this article is to analyze the presence of organic matter in urban sewage using a water quality model whose main parameters are dissolved oxygen and biochemical oxygen demand. Wastewater management methodologies can contribute to public health, sanitation, and improved conservation of water resources. PMID:16832543

Cunha, Cynara de Lourdes da Nóbrega; Ferreira, Aldo Pacheco

2006-08-01

195

Effect of modified weather and environmental conditions on the regional ozone load  

NASA Astrophysics Data System (ADS)

Near-surface ozone plays an important role in the formation of the photochemical air pollution and affects both vegetation and human health. Recently, it has also been shown that the indirect radiative forcing of climate change through ozone effecting on the land carbon sink could be an important factor and can induce a positive feedback for global warming. This impact study examines the connections between the possible changes of atmospheric and environmental properties due to the regional climate change and the tropospheric ozone load on different vegetations over Central European region. For this purpose, concentration and flux-based ozone metrics with their spatial and seasonal variability were estimated under different weather and environmental conditions. Simulations were performed with a sophisticated deposition model using different regional climate scenarios with a special emphasis on the possible modifications of the obscured factors of the ozone deposition (water vapour pressure, soil water deficit, etc.). Additionally, different stress-function parameterizations ant their effect on the results were also analysed.

Komjáthy, E.; Mészáros, R.; Lagzi, I.

2010-09-01

196

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

197

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

198

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

199

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

200

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

201

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

202

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

203

Characterization of Rice NADPH Oxidase Genes and Their Expression under Various Environmental Conditions  

PubMed Central

Plasma membrane NADPH oxidases (Noxs) are key producers of reactive oxygen species under both normal and stress conditions in plants. We demonstrate that at least eleven genes in the genome of rice (Oryza sativa L.) were predicted to encode Nox proteins, including nine genes (OsNox1–9) that encode typical Noxs and two that encode ancient Nox forms (ferric reduction oxidase 1 and 7, OsFRO1 and OsFRO7). Phylogenetic analysis divided the Noxs from nine plant species into six subfamilies, with rice Nox genes distributed among subfamilies I to V. Gene expression analysis using semi-quantitative RT-PCR and real-time qRT-PCR indicated that the expression of rice Nox genes depends on organs and environmental conditions. Exogenous calcium strongly stimulated the expression of OsNox3, OsNox5, OsNox7, and OsNox8, but depressed the expression of OsFRO1. Drought stress substantially upregulated the expression of OsNox1–3, OsNox5, OsNox9, and OsFRO1, but downregulated OsNox6. High temperature upregulated OsNox5–9, but significantly downregulated OsNox1–3 and OsFRO1. NaCl treatment increased the expression of OsNox2, OsNox8, OsFRO1, and OsFRO7, but decreased that of OsNox1, OsNox3, OsNox5, and OsNox6. These results suggest that the expression profiles of rice Nox genes have unique stress-response characteristics, reflecting their related but distinct functions in response to different environmental stresses. PMID:23629674

Wang, Gang-Feng; Li, Wen-Qiang; Li, Wen-Yan; Wu, Guo-Li; Zhou, Cong-Yi; Chen, Kun-Ming

2013-01-01

204

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

PubMed

Casuarinas are very important plants for their various uses and survival in adverse sites or harsh environments. As nitrogen fixation, in symbiosis with Frankia, is an important factor for the survival of these plants under various conditions, the basis for selecting both effective and tolerant Frankia strains and Casuarina spp., are provided. Enhancement of the symbiotic relationship between Frankia and Casuarina, by mycorrhizal infection and other biofertilizing microorganisms such as Bacillus and Azospirillum, is reflected by superior plant growth. Casuarina leaf litter is also a great source for both inorganic and organic nutrients. Therefore, careful management of the top soil layer under Casuarina trees is very important. Litter decomposition ratio is affected by many physical chemical and biological factors including temperature, moisture conditions, lignin, and C-to-N and N-to-P ratios in addition to soil biota. In general, here the above relations are discussed and an alleviation model is presented for important disturbances of natural and human origin made in soil and environment, especially in the dry regions. In conclusion, we suggest how to optimize the nitrogen fixation and plant growth under the prevalent conditions. PMID:21448712

Sayed, W F

2011-01-01

205

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

206

Environmental conditions affect transcription of the pectinase genes of Erwinia chrysanthemi 3937.  

PubMed

To depolymerize plant pectin, the phytopathogenic enterobacterium Erwinia chrysanthemi produces a series of enzymes which include a pectin-methyl-esterase encoded by the pem gene and five isoenzymes of pectate lyases encoded by the five genes pelA, pelB, pelC, pelD, and pelE. We have constructed transcriptional fusions between the pectinase gene promoters and the uidA gene, encoding beta-glucuronidase, to study the regulation of these E. chrysanthemi pectinase genes individually. The transcription of the pectinase genes is dependent on many environmental conditions. All the fusions were induced by pectic catabolic products and responded, to different degrees, to growth phase, catabolite repression, temperature, and nitrogen starvation. Transcription of pelA, pelD, and pelE was also increased in anaerobic growth conditions. High osmolarity of the culture medium increased expression of pelE but decreased that of pelD; the other pectinase genes were not affected. The level of expression of each gene was different. Transcription of pelA was very low under all growth conditions. The expression of the pelB, pelC, and pem genes was intermediate. The pelE gene had a high basal level of expression. Expression of pelD was generally the most affected by changes in culture conditions and showed a low basal level but very high induced levels. These differences in the expression of the pectinase genes of E. chrysanthemi 3937 presumably reflect their role during infection of plants, because the degradation of pectic polymers of the plant cell walls is the main determinant of tissue maceration caused by soft rot erwiniae. PMID:1447147

Hugouvieux-Cotte-Pattat, N; Dominguez, H; Robert-Baudouy, J

1992-12-01

207

Environmental conditions affect transcription of the pectinase genes of Erwinia chrysanthemi 3937.  

PubMed Central

To depolymerize plant pectin, the phytopathogenic enterobacterium Erwinia chrysanthemi produces a series of enzymes which include a pectin-methyl-esterase encoded by the pem gene and five isoenzymes of pectate lyases encoded by the five genes pelA, pelB, pelC, pelD, and pelE. We have constructed transcriptional fusions between the pectinase gene promoters and the uidA gene, encoding beta-glucuronidase, to study the regulation of these E. chrysanthemi pectinase genes individually. The transcription of the pectinase genes is dependent on many environmental conditions. All the fusions were induced by pectic catabolic products and responded, to different degrees, to growth phase, catabolite repression, temperature, and nitrogen starvation. Transcription of pelA, pelD, and pelE was also increased in anaerobic growth conditions. High osmolarity of the culture medium increased expression of pelE but decreased that of pelD; the other pectinase genes were not affected. The level of expression of each gene was different. Transcription of pelA was very low under all growth conditions. The expression of the pelB, pelC, and pem genes was intermediate. The pelE gene had a high basal level of expression. Expression of pelD was generally the most affected by changes in culture conditions and showed a low basal level but very high induced levels. These differences in the expression of the pectinase genes of E. chrysanthemi 3937 presumably reflect their role during infection of plants, because the degradation of pectic polymers of the plant cell walls is the main determinant of tissue maceration caused by soft rot erwiniae. PMID:1447147

Hugouvieux-Cotte-Pattat, N; Dominguez, H; Robert-Baudouy, J

1992-01-01

208

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. PMID:25323676

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

2015-01-01

209

Digital mapping of agri-environmental conditions and natural handicaps in the Gyöngyös LAU1 region  

NASA Astrophysics Data System (ADS)

A specific data demand on soil characteristics was put up by the elaboration of the Production Site Specific GIS e-Consulting System (PSSGeCS) planned for Northern-Hungary Region. One of the most important modules of this system, which is still under development, consists of the spatial soil information sub-system of the regional level, soil related information. For the proper operation of PSSGeCS the agri-environmental conditions had to be characterized according to the 1:10,000 scale genetic soil mapping methodology and the category system applied in the Hungarian soil-agricultural chemistry practice. The factors constraining the fertility of soils had to be featured according to the biophysical criteria system elaborated for the delimitation of naturally handicapped areas in the EU. A great amount of soil information is available in Hungary due to former mappings and surveys. The collected data are available in different scales: national, regional, micro-regional, farm and field level and generally they are related to maps. The mapping objectives and methodology of the subsequent surveys also differed, various soil features were laid emphasis on. The legacy data provided by these surveys in one hand still represent a valuable treasure of soil information at the present time, and on the other hand are generally the sole information actually available. The diversity of various surveys carried out on a common region may pose questions concerning their joint applicability, nevertheless the disadvantages can be overcome. For the Gyöngyös LAU1 region pilot area, which is about 750 km2 and situated in the Northern part of Hungary, all the available legacy soil data, both SMU and profile based, were collected. The spatial coverage of this information was neither complete nor homogeneous. As a consequence these data were not applicable in themselves to produce the required maps. They had to be integrated, harmonized and specific methods were developed for the digital mapping of the required agri-environmental conditions and biophysical criteria of natural handicaps. The spatial resolution of the derived digital soil related maps was 50 meter. Auxiliary spatial environmental information in the form of multispectral and multitemporal Landsat TM images, high resolution DEM and thematic maps on geology and landuse supported the regionalization process. Indicator (co-)kriging, principal component analysis and maximum likelihood clustering were applied for the task specific elaboration of the two digital soil map series. Our poster will display the framework and the results of this regionalization process.

Pásztor, László; Szabó, József; Bakacsi, Zsófia; Laborczi, Annamária

2013-04-01

210

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

211

Towards generalised reference condition models for environmental assessment: a case study on rivers in Atlantic Canada.  

PubMed

Evaluation of the ecological status of river sites in Canada is supported by building models using the reference condition approach. However, geography, data scarcity and inter-operability constraints have frustrated attempts to monitor national-scale status and trends. This issue is particularly true in Atlantic Canada, where no ecological assessment system is currently available. Here, we present a reference condition model based on the River Invertebrate Prediction and Classification System approach with regional-scale applicability. To achieve this, we used biological monitoring data collected from wadeable streams across Atlantic Canada together with freely available, nationally consistent geographic information system (GIS) environmental data layers. For the first time, we demonstrated that it is possible to use data generated from different studies, even when collected using different sampling methods, to generate a robust predictive model. This model was successfully generated and tested using GIS-based rather than local habitat variables and showed improved performance when compared to a null model. In addition, ecological quality ratio data derived from the model responded to observed stressors in a test dataset. Implications for future large-scale implementation of river biomonitoring using a standardised approach with global application are presented. PMID:23250724

Armanini, D G; Monk, W A; Carter, L; Cote, D; Baird, D J

2013-08-01

212

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

213

Influence of Environmental Conditions on Hydrogen Peroxide Formation by Streptococcus gordonii  

PubMed Central

Hydrogen peroxide generated by viridans group streptococci has an antagonistic effect on many bacterial species, including a number of pathogens, in the oral environment. This study examines the influence of a variety of environmental conditions on rates of hydrogen peroxide synthesis by Streptococcus gordonii. Hydrogen peroxide was synthesized at every concentration of glucose and sucrose tested from 10 ?M to 1 M, with the highest rates occurring at 0.1 mM sucrose and 1 mM glucose. S. gordonii appeared to have an intracellular store of polysaccharide which supported hydrogen peroxide formation even when the assay buffer contained no carbohydrate. Most heavy metal ions inhibited peroxidogenesis, and anaerobic conditions induced adaptive down-regulation of hydrogen peroxide synthesis; however, peroxidogenesis was generally insensitive to moderate increases in salt concentration, alteration of the mineral content of the assay solution, and changes in pH between 5.0 and 7.5. In contrast, stimulation of peroxidogenesis occurred in 1 mM Mg2+ and 10 to 50 mM potassium l-lactate. Maximum peroxidogenesis occurred during the mid-logarithmic and late-logarithmic phases of bacterial growth. These bacterial responses may have significant implications for oral ecology and oral health. PMID:10569775

Barnard, John P.; Stinson, Murray W.

1999-01-01

214

Absolute gravity measurements at three sites characterized by different environmental conditions using two portable ballistic gravimeters  

NASA Astrophysics Data System (ADS)

The performances of two absolute gravimeters at three different sites in Italy between 2009 and 2011 is presented. The measurements of the gravity acceleration g were performed using the absolute gravimeters Micro-g LaCoste FG5#238 and the INRiM prototype IMGC-02, which represent the state of the art in ballistic gravimeter technology (relative uncertainty of a few parts in 109). For the comparison, the measured g values were reported at the same height by means of the vertical gravity gradient estimated at each site with relative gravimeters. The consistency and reliability of the gravity observations, as well as the performance and efficiency of the instruments, were assessed by measurements made in sites characterized by different logistics and environmental conditions. Furthermore, the various factors affecting the measurements and their uncertainty were thoroughly investigated. The measurements showed good agreement, with the minimum and maximum differences being 4.0 and 8.3 ?Gal. The normalized errors are very much lower than 1, ranging between 0.06 and 0.45, confirming the compatibility between the results. This excellent agreement can be attributed to several factors, including the good working order of gravimeters and the correct setup and use of the instruments in different conditions. These results can contribute to the standardization of absolute gravity surveys largely for applications in geophysics, volcanology and other branches of geosciences, allowing achieving a good trade-off between uncertainty and efficiency of gravity measurements.

Greco, Filippo; Biolcati, Emanuele; Pistorio, Antonio; D'Agostino, Giancarlo; Germak, Alessandro; Origlia, Claudio; Del Negro, Ciro

2015-03-01

215

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

216

A nanofluidic device for single molecule studies with in situ control of environmental solution conditions.  

PubMed

We report an approach to study the in situ conformational response of single biomolecules such as DNA to a change in environmental solution conditions. These conditions are, for example, the composition of the buffer or the presence of protein. For this purpose, we designed and fabricated a nanofluidic device featuring two arrays of parallel nanochannels in a perpendicular configuration. The cross-sections of the channels are rectangular with a diameter down to 175 nm. These lab-on-a-chip devices were made of polydimethylsiloxane (PDMS) cast on a high quality master stamp, obtained by proton beam writing and UV lithography. Biomolecules can be inserted into the device through the array of channels in one direction, whereas the buffer can be exchanged through the intersecting array of channels in the other direction. A buffer exchange time inside the grid of nanochannels of less than one second was measured by monitoring the conductivity of salt solutions. The exchange time of a protein was typically a few seconds, as determined by imaging the influx of fluorescence labelled protamine. We demonstrate the functionality of the device by investigating the compaction of DNA by protamine and the unpacking of pre-compacted DNA through an increase in the concentration of salt. PMID:23674166

Zhang, Ce; Jiang, Kai; Liu, Fan; Doyle, Patrick S; van Kan, Jeroen A; van der Maarel, Johan R C

2013-07-21

217

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

218

Multiproxy study of the environmental conditions during the last Interglacial in NE Siberia (Dmitry Laptev Strait, East Siberian Sea)  

NASA Astrophysics Data System (ADS)

In course of the IPY 'Past permafrost' fieldwork was undertaken at coastal permafrost sections of the Dmitry Laptev Strait in summer 2007. Late Quaternary permafrost deposits were sampled for further cryolithological, sedimentological, and micro-palaeontological analyses to reconstruct landscape dynamics during several climate cycles (Wetterich et al. 2009). Records of environmental changes from the penultimate Glacial (MIS 6) to the last Interglacial (MIS 5e; ca. 130 - 115 kyr BP) are preserved in ice-wedge casts exposed along the studied coasts. Due to climate warming the transition from glacial to interglacial conditions induced extensive thawing of ice-rich permafrost (thermokarst) and the formation of ice-wedge casts. Evolving thermokarst depressions transformed formerly frozen ground into taberal (thawed and refrozen) deposits. Overlying lacustrine deposits are fossil-rich and retain evidence of changes in environmental conditions. Pollen records reflect changes from early-interglacial grass-sedge dominated tundra to shrub tundra during the thermal optimum followed by late-interglacial grass-sedge tundra. The findings of Larix (larch) pollen and macro-remains in mid-interglacial deposits from the south coast of the Dmitry Laptev Strait, and their absence in similar deposits from the north coast indicate the location of the northern tree line during the interglacial thermal optimum. Species composition and dominant taxa of cladocerans remains indicate the warmer temperature during the last Interglacial in comparison to modern conditions. Among the identified sub-fossil Cladocera taxa are those that are now found on the border of the modern tree-line and to the south of it. The rich cladoceran assemblages have been represented by various ecological groups among which most frequent are littoral phytophilic and truly planktonic organisms, presented in particular by genera Bosmina sp. The investigated chironomid community is diverse, with stable and evenly distributed structure (Shennon Index is 2,40, Pielou Index is 0,86). Littoral taxa form the basis of the investigated community and indicate temperate lacustrine conditions with shallow water and pronounced zone of macrophytes. Findings of steam and leaf mining taxa indicates presence of some submerged coarse vegetation, most probably remains of trees and shrubs. Majority of the taxa are inhabitants of hygropertic, which is indicative for unstable conditions, fluctuating water level and heterogeneous habitat controlled by complex factors, such as air exposure, insolation, unstable water temperature and dissolved oxygen concentration, etc. These conclusions are confirmed by mean July air temperature and water depth reconstructions performed with Yakutian chironomid based inference models (Nazarova et al. in press). Air T july reconstructed for the interglacial thermal optimum is 12,90±0,9oC. Rich fossil ostracod records reflecting shallow lakeshore conditions can be correlated with the thermal optimum. The last interglacial palaeoenvironmental records reflect three landscape development stages according to changes in the climatic setting: (1) thermokarst-induced formation of basins, (2) accumulation of lacustrine sequences, and (3) transformation of lake-dominated areas into polygonal tundra. The stages are considered to be of stratigraphical significance.

Wetterich, Sebastian; Frolova, Larisa; Nazarova, Larisa; Andreev, Andrei; Schirrmeister, Lutz; Kienast, Frank

2010-05-01

219

Conditionals  

E-print Network

This article introduces the classic accounts of the meaning of conditionals (material implication, strict implication, variably strict conditional) and discusses the difference between indicative and subjunctive/counterfactual ...

von Fintel, Kai

2011-01-01

220

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

PubMed Central

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

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

2005-01-01

221

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 0.2 mol L(-1). For the environmental strain (172A) an optimal encystment was obtained for basic pH (8 and 9) and for a concentration in KCl of 0.1 mol L(-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

222

Automated ambulatory assessment of cognitive performance, environmental conditions, and motor activity during military operations  

NASA Astrophysics Data System (ADS)

Until recently scientists had limited opportunities to study human cognitive performance in non-laboratory, fully ambulatory situations. Recently, advances in technology have made it possible to extend behavioral assessment to the field environment. One of the first devices to measure human behavior in the field was the wrist-worn actigraph. This device, now widely employed, can acquire minute-by-minute information on an individual"s level of motor activity. Actigraphs can, with reasonable accuracy, distinguish sleep from waking, the most critical and basic aspect of human behavior. However, rapid technologic advances have provided the opportunity to collect much more information from fully ambulatory humans. Our laboratory has developed a series of wrist-worn devices, which are not much larger then a watch, which can assess simple and choice reaction time, vigilance and memory. In addition, the devices can concurrently assess motor activity with much greater temporal resolution then the standard actigraph. Furthermore, they continuously monitor multiple environmental variables including temperature, humidity, sound and light. We have employed these monitors during training and simulated military operations to collect information that would typically be unavailable under such circumstances. In this paper we will describe various versions of the vigilance monitor and how each successive version extended the capabilities of the device. Samples of data from several studies are presented, included studies conducted in harsh field environments during simulated infantry assaults, a Marine Corps Officer training course and mechanized infantry (Stryker) operations. The monitors have been useful for documenting environmental conditions experienced by wearers, studying patterns of sleep and activity and examining the effects of nutritional manipulations on warfighter performance.

Lieberman, Harris R.; Kramer, F. Matthew; Montain, Scott J.; Niro, Philip; Young, Andrew J.

2005-05-01

223

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

224

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

PubMed

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

2013-12-01

225

EMAP AND OTHER TOOLS FOR MEASURING BIODIVERSITY HABITAT CONDITIONS AND ENVIRONMENTAL TRENDS  

EPA Science Inventory

Several research efforts that will contribute to assessment and monitoring of neotropical migratory birds are described, including: ) the use of neotropical migrants in the Environmental Monitoring and Assessment Program (EMAP) as potential indicators of general environmental con...

226

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

227

Transgene Expression and Bt Protein Content in Transgenic Bt Maize (MON810) under Optimal and Stressful Environmental Conditions  

PubMed Central

Bt protein content in transgenic insect resistant (Bt) maize may vary between tissues within plants and between plants growing under different environmental conditions. However, it is unknown whether and how Bt protein content correlates with transgene expression, and whether this relationship is influenced by stressful environmental conditions. Two Bt maize varieties containing the same transgene cassette (MON 810) were grown under optimal and stressful conditions. Before and during stress exposure, the upper leaves were analysed for transgene expression using quantitative RT-PCR and for Bt content using ELISA. Under optimal conditions there was no significant difference in the transgene expression between the two investigated Bt maize varieties whereas Bt protein content differed significantly. Transgene expression was correlated with Bt protein content in only one of the varieties. Under stressful environmental conditions we found similar transgene expressions as under optimal conditions but Bt content responded differently. These results suggest that Bt content is not only controlled by the transgene expression but is also dependent on the genetic background of the maize variety. Under stressful conditions the concentration of Bt protein is even more difficult to predict. PMID:25853814

Trtikova, Miluse; Wikmark, Odd Gunnar; Zemp, Niklaus; Widmer, Alex; Hilbeck, Angelika

2015-01-01

228

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

229

Conclusions from recent pionic--atom experiments  

SciTech Connect

The most recent pionic--hydrogen experiment marks the completion of a whole series of measurements, the main goal of which was to provide conclusive data on pion--nucleon interaction at threshold for comparison with calculations from Chiral perturbation theory. The precision achieved for hadronic shift and broadening of 0.2% and 2%, respectively, became possible by comprehensive studies of cascade effects in hydrogen and other light exotic atoms including results from the last years of LEAR operation. In order to obtain optimum conditions for the Bragg crystal spectrometer, the cyclotron trap II has been used to provide a suitable X--ray source. To characterize the bent crystal spectrometer, the cyclotron trap has been modified to operate as an electron--cyclotron resonance source, which produces with high intensity narrow X-ray transitions in the few keV range originating from highly charged ions.

Gotta, D.; Hennebach, M.; Nekipelov, M.; Strauch, Th. [Institut fuer Kernphysik, Forschungszentrum Juelich, D--52425 Juelich (Germany); Amaro, F.; Covita, D. S.; Santos, J. M. F. dos; Veloso, J. F. C. A. [Dept. of Physics, Coimbra University, P--3000 Coimbra (Portugal); Anagnostopoulos, D. F. [Dept. of Material Science and Engineering, University of Ioannina, Ioannina, GR--45110 (Greece); Biri, S. [Institut of Nuclear Research, Hungarian Academy of Sciences, H--4001 Debrecen (Hungary); Gorke, H. [Zentrallabor fuer Elektronik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Gruber, A.; Hirtl, A.; Ishiwatari, T.; Marton, J.; Schmid, Ph.; Zmeskal, J. [Stefan Meyer Institut, Austrian Academy of Sciences, A--1090 Vienna (Austria); Indelicato, P.; Jensen, Th.; Le Bigot, E.-O. [Lab. Kastler Brossel, UPMC-Paris 6, ENS, CNRS, 4 place Jussieu, F--75005 Paris (France)] (and others)

2008-08-08

230

Impact of tidal power dams upon tides and environmental conditions in the Sea of Okhotsk  

NASA Astrophysics Data System (ADS)

The transformation of natural tidal sea-level and currents is studied resulting from large-scale tidal power plant (TPP) dams in bays of the Sea of Okhotsk (SO). Some effects due to this transformation are estimated based on predictive modelling and a number of expected changes in amplitudes and phases, and spectral composition of tidal oscillations are described. Changes of morphometric properties of basins change the character of tidal motions even on significant distance from a dam. That is why, it is impossible to estimate this impact as usual boundary-value problems. The problem is solved based on "impedance" conditions on the open boundary of the model area, allowing to take into account the radiation of the additional perturbations induced by both waves reflected from the dam and nonlinear effects inside the area. In general, the transformation effects are proportional to the dam size and depend essentially on the dam location, the creation of which can change dissipative and resonance properties of the bays. The changes in tidal energetics of SO due to the dam construction are also considered to show noticeable reconstruction of horizontal energy fluxes and changes in the energy dissipation. Possible environmental consequences are related mainly to the transformation of tidal currents.

Nekrasov, A. V.; Romanenkov, D. A.

2010-04-01

231

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

232

Modelling Stream-Fish Functional Traits in Reference Conditions: Regional and Local Environmental Correlates  

PubMed Central

Identifying the environmental gradients that control the functional structure of biological assemblages in reference conditions is fundamental to help river management and predict the consequences of anthropogenic stressors. Fish metrics (density of ecological guilds, and species richness) from 117 least disturbed stream reaches in several western Iberia river basins were modelled with generalized linear models in order to investigate the importance of regional- and local-scale abiotic gradients to variation in functional structure of fish assemblages. Functional patterns were primarily associated with regional features, such as catchment elevation and slope, rainfall, and drainage area. Spatial variations of fish guilds were thus associated with broad geographic gradients, showing (1) pronounced latitudinal patterns, affected mainly by climatic factors and topography, or (2) at the basin level, strong upstream-downstream patterns related to stream position in the longitudinal gradient. Maximum native species richness was observed in midsize streams in accordance with the river continuum concept. The findings of our study emphasized the need to use a multi-scale approach in order to fully assess the factors that govern the functional organization of biotic assemblages in ‘natural’ streams, as well as to improve biomonitoring and restoration of fluvial ecosystems. PMID:23029242

Oliveira, João M.; Segurado, Pedro; Santos, José M.; Teixeira, Amílcar; Ferreira, Maria T.; Cortes, Rui V.

2012-01-01

233

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

234

Survival response of Bacteriovorax in surface biofilm versus suspension when stressed by extremes in environmental conditions.  

PubMed

The Bacteriovorax, previously in the genus Bdellovibrio, are prokaryotes that prey upon many Gram-negative bacteria. They are ubiquitous in salt-water environments and have been reported to have a strong association with biofilms. The purpose of this study was to test the hypothesis that this association affords protection for the Bacteriovorax and enhances their survival in nature when exposed to extreme environmental conditions. Experiments were designed to compare their survival in biofilms versus in suspension when exposed to extremes in salinity and temperature. Natural mixed-population biofilms generated in moderate-salinity (16 per thousand) Patuxent River water and containing Bacteriovorax were exposed to drastic changes in salinity by placing in low-salinity (1 per thousand) river water and salt-free (no measurable salinity) distilled water for up to 14 days. In a separate trial, the biofilm was exposed to extremes in temperature, 5 degrees C and 35 degrees C, for up to 12 weeks in aquarium mesocosms. Simultaneously, suspensions of the Bacteriovorax were exposed to the same extremes in salinity and temperature as biofilms. The results revealed that the Bacteriovorax typically were able to survive for a week or longer while in association with biofilms than when in suspension. These results are consistent with observations from nature and establish that biofilms are important in the survival and ecology of the Bacteriovorax. PMID:19267151

Williams, Henry N; Turng, Been-Foo; Kelley, Jacqueline I

2009-10-01

235

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

PubMed

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. PMID:25699242

Rosini, Roberto; Margarit, Immaculada

2015-01-01

236

Environmental conditions in near-wall plasmas generated by impact of energetic particle fluxes  

NASA Astrophysics Data System (ADS)

Directional flows of energetic ions produced by laser-exploded foils were used to investigate transient phenomena accompanying the plasma interaction with surfaces of solid targets (walls). In experiments carried out on the iodine laser system PALS, the formation of energetic plasma jets from burn-through foils of Al and Ta was optimized using the three-frame interferometry and applied to a design of alternate experimental configurations. The interaction of the directional plasma flows with secondary targets was studied via X-ray imaging, optical and high-resolution X-ray spectroscopy. The environmental conditions in near-wall plasmas created at surfaces of plasma-exposed solids, in particular the velocity distribution of impinging and back-scattered ions, were determined via analysis of the observed spatially-resolved spectra of Al Ly? and He? groups. The validity of the ion velocity gradients derived from the Doppler effect induced shifts and splitting of the spectral lines was supported by theoretical modeling based on a combination of hydrodynamic, atomic and collisional-radiative codes.

Renner, O.; Šmíd, M.; Burian, T.; Juha, L.; Krása, J.; Krouský, E.; Matulková, I.; Skála, J.; Velyhan, A.; Liska, R.; Velechovský, J.; Pisarczyk, T.; Chodukowski, T.; Larroche, O.; Ullschmied, J.

2013-09-01

237

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

238

How environmental conditions impact mosquito ecology and Japanese encephalitis: An eco-epidemiological approach.  

PubMed

Japanese encephalitis (JE) is one of the major vector-borne diseases in Southeast Asia and the Western Pacific region, posing a threat to human health. In rural and suburban areas, traditional rice farming and intensive pig breeding provide an ideal environment for both mosquito development and the transmission of JEV among human beings. Combining surveillance data for mosquito vectors, human JE cases, and environmental conditions in Changsha, China, 2004-2009, generalized threshold models were constructed to project the mosquito and JE dynamics. Temperature and rainfall were found to be closely associated with mosquito density at 1, and 4month lag, respectively. The two thresholds, maximum temperature of 22-23°C for mosquito development and minimum temperature of 25-26°C for JEV transmission, play key roles in the ecology of JEV. The model predicts that, in the upper regime, a 1g/m(3) increase in absolute humidity would on average increase human cases by 68-84%. A shift in mosquito species composition in 2007 was observed, and possibly caused by a drought. Effective predictive models could be used in risk management to provide early warnings for potential JE transmission. PMID:25771078

Tian, Huai-Yu; Bi, Peng; Cazelles, Bernard; Zhou, Sen; Huang, Shan-Qian; Yang, Jing; Pei, Yao; Wu, Xiao-Xu; Fu, Shi-Hong; Tong, Shi-Lu; Wang, Huan-Yu; Xu, Bing

2015-06-01

239

Dependence of Cumulus Anvil Radiative Properties on Environmental Conditions in the Tropical West Pacific  

NASA Technical Reports Server (NTRS)

Areally extensive, optically thick anvil clouds associated with mesoscale convective clusters dominate the shortwave cloud forcing in the tropics and provide longwave forcing comparable to that of thin cirrus. Changes in the cover and optical thickness of tropical anvils as climate warms can regulate the sign of cloud feedback. As a prelude to the study of MMCR data from the ARM TWP sites, we analyze ISCCP-derived radiative characteristics of anvils observed in the tropical west Pacific during the TOGA-COARE IOP. Anvils with radius greater than 100 km were identified and tracked from inception to decay using the Machado-Rossow algorithm. Corresponding environmental conditions just prior to the start of the convectove event were diagnosed using the Lin-Johnson objective analysis product. Small clusters (100-200 km radius) are observed to have a broad range of optical thicknesses (10-50), while intermediate optical thickness clusters are observed to range in size from 100 km to almost 1000 km. Large-size clusters appear to be favored by strong pre-storm large scale upward motion throughout the troposphere, moist low-to-midlevel relative humidities, environments with slightly higher CAPE than those for smaller clusters, and strong front-to-rear flow. Optically thick anvils are favored in situations of strong low-level moisture convergence and strong upper-level shear.

Ye, B.; DelGenio, A. D.

1999-01-01

240

Fine-scale spatial variation in plant species richness and its relationship to environmental conditions in coastal marshlands  

USGS Publications Warehouse

Previous studies have shown that variations in environmental conditions play a major role in explaining variations in plant species richness at community and landscape scales. In this study, we considered the degree to which fine-scale spatial variations in richness could be related to fine-scale variations in abiotic and biotic factors. To examine spatial variation in richness, grids of 1 m(2) plots were laid out at five sites within a coastal riverine wetland landscape. At each site, a 5 x 7 array of plots was established adjacent to the river's edge with plots one meter apart. In addition to the estimation of species richness, environmental measurements included sediment salinity, plot microelevation, percent of plot recently disturbed, and estimated community biomass. Our analysis strategy was to combine the use of structural equation modeling (path modeling) with an assessment of spatial association. Mantel's tests revealed significant spatial autocorrelation in species richness at four of the five sites sampled, indicating that richness in a plot correlated with the richness of nearby plots. We subsequently considered the degree to which spatial autocorrelations in richness could be explained by spatial autocorrelations in environmental conditions. Once data were corrected for environmental correlations, spatial autocorrelation in residual species richness could not be detected at any site. Based on these results, we conclude that in this coastal wetland, there appears to be a fine-scale mapping of diversity to microgradients in environmental conditions.

Mancera, J.E.; Meche, G.C.; Cardona-Olarte, P.P.; Castaneda-Moya, E.; Chiasson, R.L.; Geddes, N.A.; Schile, L.M.; Wang, H.G.; Guntenspergen, G.R.; Grace, J.B.

2005-01-01

241

Fish communities and related environmental conditions of the lower Boise River, southwestern Idaho, 1974-2004  

USGS Publications Warehouse

Within the last century, the lower Boise River has been transformed from a meandering, braided, gravel-bed river that supported large runs of salmon to a channelized, regulated, urban river that provides flood control and irrigation water to more than 1,200 square miles of land. An understanding of the current status of the river's fish communities and related environmental conditions is important to support the ongoing management of the Boise River. Therefore, fish community data from the U.S. Geological Survey and the Idaho Department of Fish and Game collected since 1974 were analyzed to describe the status of fish communities in the lower Boise River. Each set of data was collected to address different study objectives, but is combined here to provide an overall distribution of fish in the lower Boise River over the last 30 years. Twenty-two species of fish in 7 families have been identified in the lower Boise River-3 salmonidae, trout and whitefish; 2 cottidae, sculpins; 3 catostomidae, suckers; 7 cyprinidae, minnows; 4 centrarchidae, sunfish; 2 ictaluridae, catfish; and 1 cobitidae, loach. Analysis of fish community data using an Index of Biotic Integrity (IBI) for Northwest rivers shows a decrease in the biotic integrity in a downstream direction, with the lowest IBI near the mouth of the Boise River. The number of tolerant and introduced fish were greater in the lower reaches of the river. Changes in land use, habitat, and water quality, as well as regulated streamflow have affected the lower Boise River fish community. IBI scores were negatively correlated with maximum instantaneous water temperature, specific conductance, and suspended sediment; as well as the basin land-use metrics, area of developed land, impervious surface area, and the number of major diversions upstream of a site. Fish communities in the upstream reaches were dominated by piscivorous fish, whereas the downstream reaches were dominated by tolerant, omnivorous fish. The percentage of sculpin in the river decreased in a downstream direction, and sculpin disappear completely at sites downstream of Glenwood Bridge. The sculpin population increased downstream of the Lander wastewater-treatment facility within the last decade, possibly as a result of improved wastewater treatment. The condition of the mountain whitefish (Prosopium williamsoni) throughout the lower Boise River was good and was similar both to the condition of mountain whitefish from least-disturbed rivers in southern Idaho and to the North American standard weight for mountain whitefish.

MacCoy, Dorene E.

2006-01-01

242

Feasibility of Fiber Bragg Grating and Long-Period Fiber Grating Sensors under Different Environmental Conditions  

PubMed Central

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/ h to ?1.3548 °C/ 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

243

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

244

The effects of environmental conditioning on tensile properties of high performance aramid fibers at near-ambient temperatures  

Microsoft Academic Search

Aramid and aramid copolymer fibers are used in a wide variety of military and civilian applications; however, the long-term effects of environmental exposure on tensile properties are still not well understood. The current effort investigates the effect of hygrothermal conditioning on the tensile properties of Kevlar® KM2 ®, Twaron®, and the newly available Russian copolymer, Armos® high performance fibers. Moisture

A. Abu Obaid; J. M. Deitzel; J. W. Gillespie; J. Q. Zheng

2011-01-01

245

Development of crystalline peroxisomes in methanol-grown cells of the yeast Hansenula polymorpha and its relation to environmental conditions  

Microsoft Academic Search

The development of peroxisomes has been studied in cells of the yeast Hansenula polymorpha during growth on methanol in batch and chemostat cultures. During bud formation, new peroxisomes were generated by the separation of small peroxisomes from mature organelles in the mother cells. The number of peroxisomes migrating to the buds was dependent upon environmental conditions. Aging of cells was

M. Veenhuis; J. P. van Dijken; S. A. F. Pilon; W. Harder

1978-01-01

246

Are yolk androgens adjusted to environmental conditions? A test in two seabirds that lay single-egg clutches  

Microsoft Academic Search

It is widely believed that female birds strategically allocate androgens to yolk in the manner that best equips offspring for feeding conditions during their development. Because most avian studies have focused on multi-egg clutch species, and interpreted results within the framework of sibling competition, we still know little about how yolk androgens might be allocated in direct response to environmental

BriAnne Addison; Z. Morgan Benowitz-Fredericks; J. Mark Hipfner; Alexander S. Kitaysky

2008-01-01

247

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...

248

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...

249

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

250

Lubricity effect of carbon dioxide used as an environmentally friendly refrigerant in air-conditioning and refrigeration compressors  

Microsoft Academic Search

Environmental concerns have increased the interest in alternative natural refrigerants for air-conditioning and refrigeration compressors. Carbon dioxide (CO2) or R744 is an attractive candidate to replace harmful hydrofluorocarbon refrigerants, which will need to be replaced in the near future due to their high global warming potential. In this paper the tribological behavior of gray cast iron in the presence of

Emerson Escobar Nunez; Kyriaki Polychronopoulou; Andreas A. Polycarpou

2010-01-01

251

Listeria monocytogenes Scott A: Cell Surface Charge, Hydrophobicity, and Electron Donor and Acceptor Characteristics under Different Environmental Growth Conditions  

Microsoft Academic Search

We determined the variations in the surface physicochemical properties of Listeria monocytogenes Scott A cells that occurred under various environmental conditions. The surface charges, the hydrophobicities, and the electron donor and acceptor characteristics of L. monocytogenes Scott A cells were compared after the organism was grown in different growth media and at different temperatures; to do this, we used microelectrophoresis

ROMAIN BRIANDET; THIERRY MEYLHEUC; CATHERINE MAHER; MARIE NOELLE BELLON-FONTAINE

1999-01-01

252

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

253

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

254

Reverse-engineering the Arabidopsis thaliana transcriptional network under changing environmental conditions  

PubMed Central

Background Understanding the molecular mechanisms plants have evolved to adapt their biological activities to a constantly changing environment is an intriguing question and one that requires a systems biology approach. Here we present a network analysis of genome-wide expression data combined with reverse-engineering network modeling to dissect the transcriptional control of Arabidopsis thaliana. The regulatory network is inferred by using an assembly of microarray data containing steady-state RNA expression levels from several growth conditions, developmental stages, biotic and abiotic stresses, and a variety of mutant genotypes. Results We show that the A. thaliana regulatory network has the characteristic properties of hierarchical networks. We successfully applied our quantitative network model to predict the full transcriptome of the plant for a set of microarray experiments not included in the training dataset. We also used our model to analyze the robustness in expression levels conferred by network motifs such as the coherent feed-forward loop. In addition, the meta-analysis presented here has allowed us to identify regulatory and robust genetic structures. Conclusions These data suggest that A. thaliana has evolved high connectivity in terms of transcriptional regulation among cellular functions involved in response and adaptation to changing environments, while gene networks constitutively expressed or less related to stress response are characterized by a lower connectivity. Taken together, these findings suggest conserved regulatory strategies that have been selected during the evolutionary history of this eukaryote. PMID:19754933

Carrera, Javier; Rodrigo, Guillermo; Jaramillo, Alfonso; Elena, Santiago F

2009-01-01

255

Sensitive and Selective Culture Medium for Detection of Environmental Clostridium difficile Isolates without Requirement for Anaerobic Culture Conditions  

PubMed Central

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

2014-01-01

256

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

257

Role of Environmental Conditions on the Fate and Transport of Engineered Nanomaterials in the Subsurface  

NASA Astrophysics Data System (ADS)

Industrial processes and consumer products based on nanotechnology are a fast-rising component of the current economy, predicted to be $1 trillion industry by 2015. As most of the industries are embracing nanotechnology in their production for novel properties and higher efficiency, nanomaterial-based products will capture the significant portion of the consumer market in near future. Hence, nanomaterial-based products will be ubiquitous and the byproducts of the production will be released in the environment, demanding the investigation of fate, transport and toxicity of these novel materials. Therefore, in this study the fate and transport of nanoparticles in aquatic environments have been investigated. Titanium dioxide (TiO2) has been used as model nanoparticles, as it is one of most widely used nanoparticles in consumer products and industry. The project was developed to identify the fundamental mechanisms involved in the transport of nano-TiO2 and the contribution of various environmental parameters including solution chemistry (pH, ionic strength, and ion valence), hydrodynamic effects, and the presence of natural organic matter (NOM) and bacteria. Extensive physicochemical characterization of the nanoparticles was conducted under various solution condition including electrokinetic characterization, hydrodynamic diameter, and stability of nanoparticles. Transport studies have been conducted in both macroscopic (packed-bed column) and microscopic (parallel plate flow cell) systems. The combination of these transport and characterization tools has demonstrated the critical role that pH, ionic strength and valence, NOM, bacteria, primary nanoparticle size and aggregation state play in the transport. Results from both transport systems, as well as bacterial and particle characterization will be presented, as well as the proposed transport and retention mechanisms observed.

Walker, S. L.; Chowdhury, I.

2011-12-01

258

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

259

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

260

Infrared Spectroscopy of Pollen Identifies Plant Species and Genus as Well as Environmental Conditions  

PubMed Central

Background It is imperative to have reliable and timely methodologies for analysis and monitoring of seed plants in order to determine climate-related plant processes. Moreover, impact of environment on plant fitness is predominantly based on studies of female functions, while the contribution of male gametophytes is mostly ignored due to missing data on pollen quality. We explored the use of infrared spectroscopy of pollen for an inexpensive and rapid characterization of plants. Methodology The study was based on measurement of pollen samples by two Fourier transform infrared techniques: single reflectance attenuated total reflectance and transmission measurement of sample pellets. The experimental set, with a total of 813 samples, included five pollination seasons and 300 different plant species belonging to all principal spermatophyte clades (conifers, monocotyledons, eudicots, and magnoliids). Results The spectroscopic-based methodology enables detection of phylogenetic variations, including the separation of confamiliar and congeneric species. Furthermore, the methodology enables measurement of phenotypic plasticity by the detection of inter-annual variations within the populations. The spectral differences related to environment and taxonomy are interpreted biochemically, specifically variations of pollen lipids, proteins, carbohydrates, and sporopollenins. The study shows large variations of absolute content of nutrients for congenital species pollinating in the same environmental conditions. Moreover, clear correlation between carbohydrate-to-protein ratio and pollination strategy has been detected. Infrared spectral database with respect to biochemical variation among the range of species, climate and biogeography will significantly improve comprehension of plant-environment interactions, including impact of global climate change on plant communities. PMID:24748390

Zimmermann, Boris; Kohler, Achim

2014-01-01

261

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

262

Variation in early-life telomere dynamics in a long-lived bird: links to environmental conditions and survival  

PubMed Central

ABSTRACT Conditions experienced during early life can have profound consequences for both short- and long-term fitness. Variation in the natal environment has been shown to influence survival and reproductive performance of entire cohorts in wild vertebrate populations. Telomere dynamics potentially provide a link between the early environment and long-term fitness outcomes, yet we know little about how the environment can influence telomere dynamics in early life. We found that environmental conditions during growth have an important influence on early-life telomere length (TL) and attrition in nestlings of a long-lived bird, the European storm petrel Hydrobates pelagicus. Nestlings reared under unfavourable environmental conditions experienced significantly greater telomere loss during postnatal development compared with nestlings reared under more favourable natal conditions, which displayed a negligible change in TL. There was, however, no significant difference in pre-fledging TL between cohorts. The results suggest that early-life telomere dynamics could contribute to the marked differences in life-history traits that can arise among cohorts reared under different environmental conditions. Early-life TL was also found to be a significant predictor of survival during the nestling phase, providing further evidence for a link between variation in TL and individual fitness. To what extent the relationship between early-life TL and mortality during the nestling phase is a consequence of genetic, parental and environmental factors is currently unknown, but it is an interesting area for future research. Accelerated telomere attrition under unfavourable conditions, as observed in this study, might play a role in mediating the effects of the early-life environment on later-life performance. PMID:25617465

Watson, Hannah; Bolton, Mark; Monaghan, Pat

2015-01-01

263

Environmental conditions experienced during the tadpole stage alter post-metamorphic glucocorticoid response to stress in an amphibian.  

PubMed

Exposure to adverse environmental conditions during early development can shape life-history traits and have lasting effects on physiological function in later life. Although findings within the biomedical literature have shown that environmentally induced elevations in glucocorticoids (GCs) during critical developmental windows can cause persistent carry-over effects (i.e., developmental programming), little is known about whether such effects of GCs can be generalized to wildlife species. Using wood frogs as a study species, we conducted an experiment with a split-plot design to assess the short-term and the long-term physiological consequences of availability of food, hydroperiod length (i.e., pond drying), and the interaction between these two environmental conditions. In outdoor experimental ponds, we reared tadpoles in chronically high or low-food conditions, and tadpoles from each pond experienced either high water until metamorphosis or a reduction in water volume during late developmental stages (after Gosner stage 38). After metamorphosis, animals were housed individually and fed ad libitum for 10 weeks, and growth rate, fat content, and resting and acute stress-induced GC levels were measured. We found that tadpoles experiencing low availability of food and reduced water volume had elevated GC levels, reduced mass, and body condition as they approached metamorphosis. At 10 weeks after metamorphosis, we found that these two conditions also had persistent interactive effects on post-metamorphic allocation of resources to growth, energy storage, and responsiveness of GCs to a novel stressor. Of individuals that experienced reduced water volume, only those that experienced high food as tadpoles were able to catch up to individuals that did not experience reduced water volume in terms of body mass, femur length, and body condition, and they allocated more resources to fat storage. By contrast, 10-week old frogs with low-food and that experienced low water volume and low-food levels as tadpoles allocated fewer resources to mass-specific growth, stored less fat, and exhibited blunted GC response to a novel stressor relative to those that did not experience water-reduction. Our findings demonstrate that environmental conditions experienced prior to and during important developmental transitions shape resource allocation and the ability to physiologically respond to future stressors in juvenile and potentially adult animals. These results suggest that chronic and acute environmental stressors experienced during early life stages can have cumulative and interactive effects that need to be considered when modeling the ecological and evolutionary consequences of environmental change on populations. PMID:23922274

Crespi, Erica J; Warne, Robin W

2013-12-01

264

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

265

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

266

Thermo-mechanical response of poly(methyl methacrylate) (PMMA) large volumes exposed to time-dependent environmental conditions  

NASA Astrophysics Data System (ADS)

Low thermal conductivity and elevated absorbance of large bulky volumes of poly(methyl methacrylate) (PMMA) exposed to moderately aggressive environmental conditions may cooperate to determine critical mechanical conditions, kindling unexpected high thermal stresses values which lead the material to failure. From the engineering point of view, this can be explained as the result of two concomitant phenomena which activate a cascade of events: very sharp thermal gradients engendered by transient thermal processes induced by cyclic environmental conditions, combined with significant bulk heat generation due to the high thermal inertia of massive PMMA volumes, in turn aggravating the steepness of the thermal gradients, may in fact ingenerate severe stress regimes, potentially undermining the structural stability of the material. Moving from these considerations, the present study is aimed to investigate possible rupture of PMMA blocks experiencing heating processes as a consequence of their exposure to outdoor cyclic environmental conditions. The problem is approached by means of both rigorous analytical arguments and the Finite Element based numerical methods, finally exploiting the theoretical outcomes to formulate a hypothesis which might explain the still unclear phenomenon of the sudden breaking of the PMMA structure, named Huge Wine Glass and designed by the world famous Japanese architect Toyo Ito, which occurred in Pescara (Italy) in 2009.

Fraldi, M.; Esposito, L.; Perrella, G.; Cutolo, A.

2014-02-01

267

Towards understanding the influence of environmental conditions on demersal resources and ecosystems in the western Mediterranean: Motivations, aims and methods of the IDEADOS project  

NASA Astrophysics Data System (ADS)

The multidisciplinary IDEADOS project funded by the Spanish Government was developed between 2009 and 2012 aiming to determine the relationships between environmental conditions and the nekto-benthic slope communities in two areas of the western Mediterranean, north and south of the Balearic Islands, with different geomorphologic and hydrodynamic characteristics. In this paper we describe the background and goals of this project, its study area and the sampling strategy applied, as well as the main conclusions reached in a final workshop. This volume is a compendium of the main contributions presented at this workshop, which have been peer-reviewed and can represent the state of the art of the complex interactions between the pelagic domain and the slope benthic communities, within the context of the hydrodynamics and oligotrophy of the Balearic Islands, and considering different temporal scales and organization levels.

Massutí, E.; Olivar, M. P.; Monserrat, S.; Rueda, L.; Oliver, P.

2014-10-01

268

40 CFR 86.1312-2007 - Filter stabilization and microbalance workstation environmental conditions, microbalance...  

Code of Federal Regulations, 2012 CFR

40 Protection of Environment 20 2012-07-01 2012-07-01...86.1312-2007 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... (i) The filter stabilization environment shall be maintained at 22 °C...

2012-07-01

269

40 CFR 86.1312-2007 - Filter stabilization and microbalance workstation environmental conditions, microbalance...  

Code of Federal Regulations, 2013 CFR

40 Protection of Environment 20 2013-07-01 2013-07-01...86.1312-2007 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... (i) The filter stabilization environment shall be maintained at 22 °C...

2013-07-01

270

Fatigue Crack Growth Analysis Under Spectrum Loading in Various Environmental Conditions  

NASA Astrophysics Data System (ADS)

The fatigue process consists, from the engineering point of view, of three stages: crack initiation, fatigue crack growth, and the final failure. It is also known that the fatigue process near notches and cracks is governed by local strains and stresses in the regions of maximum stress and strain concentrations. Therefore, the fatigue crack growth can be considered as a process of successive crack increments, and the fatigue crack initiation and subsequent growth can be modeled as one repetitive process. The assumptions mentioned above were used to derive a fatigue crack growth model based, called later as the UniGrow model, on the analysis of cyclic elastic-plastic stresses-strains near the crack tip. The fatigue crack growth rate was determined by simulating the cyclic stress-strain response in the material volume adjacent to the crack tip and calculating the accumulated fatigue damage in a manner similar to fatigue analysis of stationary notches. The fatigue crack growth driving force was derived on the basis of the stress and strain history at the crack tip and the Smith-Watson-Topper (SWT) fatigue damage parameter, D = ?max??/2. It was subsequently found that the fatigue crack growth was controlled by a two-parameter driving force in the form of a weighted product of the stress intensity range and the maximum stress intensity factor, ? K p K {max/1- p }. The effect of the internal (residual) stress induced by the reversed cyclic plasticity has been accounted for and therefore the two-parameter driving force made it possible to predict the effect of the mean stress including the influence of the applied compressive stress, tensile overloads, and variable amplitude spectrum loading. It allows estimating the fatigue life under variable amplitude loading without using crack closure concepts. Several experimental fatigue crack growth datasets obtained for the Al 7075 aluminum alloy were used for the verification of the proposed unified fatigue crack growth model. The method can be also used to predict fatigue crack growth under constant amplitude and spectrum loading in various environmental conditions such as vacuum, air, and corrosive environment providing that appropriate limited constant amplitude fatigue crack growth data obtained in the same environment are available. The proposed methodology is equally suitable for fatigue analysis of smooth, notched, and cracked components.

Mikheevskiy, S.; Glinka, G.; Lee, E.

2013-03-01

271

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

272

Sensitivity of modelled channel network formation to environmental conditions and initial bathymetry  

NASA Astrophysics Data System (ADS)

Estuaries show a variety of distinctive geomorphic features that reflect differences in environmental conditions, such as geological constraints, hydrodynamic forcing (e.g. tidal range, wave climate), sediment loads from the catchment, and the presence and types of both vegetation and benthic organisms. These differences yield varying patterns of sediment erosion/deposition and consequently determine the current shape of the estuary and its future evolution. Understanding how estuarine systems evolve as a function of both natural and anthropogenic drivers is still a main research topic in coastal science. Both the short- and long-term evolution of estuaries are affected by the dynamics related to tidal channel networks. Channel networks often exhibit complex morphological patterns and their initial formation is not entirely understood. Also, the subsequent evolution of channel networks can be accompanied by the development of tidal flats which provide ecologically important habitats. Despite their importance, observations of channel network formation involve large spatial and temporal scales so that detailed studies have rarely been reported. Recently, modelling approaches have been developed to study the long-term evolution of tidal basins and the associated formation of channel patterns. A model has been developed to simulate the formation of channel networks and tidal flats as a result of the interactions between hydrodynamics, sediment transport, and bed elevation change. Simulations were undertaken using idealised initial bathymetries. Flow velocities are computed using an open source numerical model (ELCOM; Estuary and Lake Computer Model) that solves the unsteady Reynolds-averaged Navier-Stokes equations for incompressible flow using the hydrostatic assumption. The computed flow velocities drive sediment transport, which is calculated using formulas widely adopted in sediment transport studies. Gradients in sediment transport rate yield morphological change which feed back into the hydrodynamic part of the model, thus coupling the different subsystems of the morphodynamic feedback loop. Hydrodynamic conditions are assumed to remain constant unless significant changes in the morphology have occurred. This allows us to reduce numerical effort and facilitates the execution of long-term simulations. Modelling results indicate that the morphodynamic interactions can cause channel initiation and potentially give rise to channel pattern development. A sensitivity analysis is performed to show that the sediment grain size and tidal range mainly affect the timescale over which channel initiation occurs. We also varied the initial depth of the basin to assess the influence of initial bathymetry on morphological change. Channels start to form rapidly in the case of a shallow basin. When the basin is deeper, the bathymetry evolves differently in a remarkable way. While channels develop in the upper part of the basin, a flood-tidal delta forms simultaneously just landward of the inlet. Eventually, this flood delta channelizes and a complete tidal channel network develops. Additional simulations also indicate that effects related to climate change (i.e. sea level rise) highly affect the overall morphological evolution of tidal environments.

van Maanen, Barend; Coco, Giovanni; Bryan, Karin

2010-05-01

273

Spatial and temporal variations in indoor environmental conditions, human occupancy, and operational characteristics in a new hospital building.  

PubMed

The dynamics of indoor environmental conditions, human occupancy, and operational characteristics of buildings influence human comfort and indoor environmental quality, including the survival and progression of microbial communities. A suite of continuous, long-term environmental and operational parameters were measured in ten patient rooms and two nurse stations in a new hospital building in Chicago, IL to characterize the indoor environment in which microbial samples were taken for the Hospital Microbiome Project. Measurements included environmental conditions (indoor dry-bulb temperature, relative humidity, humidity ratio, and illuminance) in the patient rooms and nurse stations; differential pressure between the patient rooms and hallways; surrogate measures for human occupancy and activity in the patient rooms using both indoor air CO2 concentrations and infrared doorway beam-break counters; and outdoor air fractions in the heating, ventilating, and air-conditioning systems serving the sampled spaces. Measurements were made at 5-minute intervals over consecutive days for nearly one year, providing a total of ?8×106 data points. Indoor temperature, illuminance, and human occupancy/activity were all weakly correlated between rooms, while relative humidity, humidity ratio, and outdoor air fractions showed strong temporal (seasonal) patterns and strong spatial correlations between rooms. Differential pressure measurements confirmed that all patient rooms were operated at neutral pressure. The patient rooms averaged about 100 combined entrances and exits per day, which suggests they were relatively lightly occupied compared to higher traffic environments (e.g., retail buildings) and more similar to lower traffic office environments. There were also clear differences in several environmental parameters before and after the hospital was occupied with patients and staff. Characterizing and understanding factors that influence these building dynamics is vital for hospital environments, where they can impact patient health and the survival and spread of healthcare associated infections. PMID:25729898

Ramos, Tiffanie; Dedesko, Sandra; Siegel, Jeffrey A; Gilbert, Jack A; Stephens, Brent

2015-01-01

274

Spatial and Temporal Variations in Indoor Environmental Conditions, Human Occupancy, and Operational Characteristics in a New Hospital Building  

PubMed Central

The dynamics of indoor environmental conditions, human occupancy, and operational characteristics of buildings influence human comfort and indoor environmental quality, including the survival and progression of microbial communities. A suite of continuous, long-term environmental and operational parameters were measured in ten patient rooms and two nurse stations in a new hospital building in Chicago, IL to characterize the indoor environment in which microbial samples were taken for the Hospital Microbiome Project. Measurements included environmental conditions (indoor dry-bulb temperature, relative humidity, humidity ratio, and illuminance) in the patient rooms and nurse stations; differential pressure between the patient rooms and hallways; surrogate measures for human occupancy and activity in the patient rooms using both indoor air CO2 concentrations and infrared doorway beam-break counters; and outdoor air fractions in the heating, ventilating, and air-conditioning systems serving the sampled spaces. Measurements were made at 5-minute intervals over consecutive days for nearly one year, providing a total of ?8×106 data points. Indoor temperature, illuminance, and human occupancy/activity were all weakly correlated between rooms, while relative humidity, humidity ratio, and outdoor air fractions showed strong temporal (seasonal) patterns and strong spatial correlations between rooms. Differential pressure measurements confirmed that all patient rooms were operated at neutral pressure. The patient rooms averaged about 100 combined entrances and exits per day, which suggests they were relatively lightly occupied compared to higher traffic environments (e.g., retail buildings) and more similar to lower traffic office environments. There were also clear differences in several environmental parameters before and after the hospital was occupied with patients and staff. Characterizing and understanding factors that influence these building dynamics is vital for hospital environments, where they can impact patient health and the survival and spread of healthcare associated infections. PMID:25729898

Ramos, Tiffanie; Dedesko, Sandra; Siegel, Jeffrey A.; Gilbert, Jack A.; Stephens, Brent

2015-01-01

275

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

276

Community-Based Research: Environmental Conditions, Human Health and the Quality of Life Residents of the Homedale neighborhood in west Phoenix are concerned about  

E-print Network

Community-Based Research: Environmental Conditions, Human Health and the Quality of Life Abstract a self-study of environmental conditions, health and the quality of life, and came to Arizona State perceptions and quality-of-life indicators. In addition, health information will be obtained from symptom

Hall, Sharon J.

277

Impact of environmental conditions on the adsorption behavior of radionuclide 63Ni(II) on ?-Al 2O 3  

Microsoft Academic Search

The fate and transport of toxic metal ions and radionuclides in the environment is generally controlled by adsorption reactions. The removal of 63Ni(II) from wastewaters by ?-Al2O3 was studied as a function of various environmental parameters such as shaking time, pH, ionic strength, foreign ions, and humic substances under ambient conditions. The results indicated that the adsorption of 63Ni(II) on

Hui Zhang; Lei Chen; Dechao Zhang; Songsheng Lu; Xianjin Yu

2011-01-01

278

The negative effect of environmental geological conditions of some geo-archaeological sites of North Coast and Alexandria  

Microsoft Academic Search

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

Hani Ibrahim; Gamal Kamh

2005-01-01

279

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

280

Effect of variation of environmental conditions on the microbial communities of deep-sea vent chimneys, cultured in a bioreactor  

Microsoft Academic Search

Both cultivation and molecular techniques were used to investigate the microbial diversity and dynamic of a deep-sea vent\\u000a chimney. The enrichment cultures performed in a gas-lift bioreactor were inoculated with a black smoker chimney sample collected\\u000a on TAG site on the mid-Atlantic ridge. To mimic as close as possible environmental conditions, the cultures were performed\\u000a in oligotrophic medium with nitrogen,

Nathalie Byrne; Françoise Lesongeur; Nadège Bienvenu; Claire Geslin; Karine Alain; Daniel Prieur; Anne Godfroy

2009-01-01

281

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

282

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

PubMed

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

2004-03-23

283

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

PubMed

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

2013-05-01

284

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

285

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

286

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

287

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

288

Genetic and maternal effect influences on viability of common frog tadpoles under different environmental conditions  

Microsoft Academic Search

The influence of environmental stress on the expression of genetic and maternal effects on the viability traits has seldom been assessed in wild vertebrates. We have estimated genetic and maternal effects on the viability (viz probability of survival, probability of being deformed, and body size and shape) of common frog, Rana temporaria, tadpoles under stressful (low pH) and nonstressful (neutral

S Pakkasmaa; J Merilä; R B O'Hara

2003-01-01

289

Environmental and genetic variation of soybean tocopherol content under Brazilian growing conditions  

Technology Transfer Automated Retrieval System (TEKTRAN)

Information about the chemical composition of soybean cultivars (cvs.) and environmental impact on their composition is important for processors and exporters to meet the demand of niche markets. Tocopherol composition (alpha, beta, delta, gamma, and total), was analyzed in seeds of 89 Brazilian so...

290

The evolution of conditional dispersal and reproductive isolation along environmental gradients  

Microsoft Academic Search

Dispersal modulates gene flow throughout a population's spatial range. Gene flow affects adaptation at local spatial scales, and consequently impacts the evolution of reproductive isolation. A recent theoretical investigation has demonstrated that local adaptation along an environmental gradient, facilitated by the evolution of limited dispersal, can lead to parapatric speciation even in the absence of assortative mating. This and other

Joshua L. Payne; Rupert Mazzucco; Ulf Dieckmann

2011-01-01

291

Effects of environmental conditions on mechanical and physical properties of flax fibers  

Microsoft Academic Search

The environmental degradation behaviour of flax fibers and their mechanical properties were investigated. Upgraded Duralin flax fibers, which have been treated by a novel treatment process for improved moisture and rot sensitivity, were studied. Results showed that upgraded Duralin flax fibers absorbed less moisture than untreated Green flax fibers, whereas the mechanical properties of the upgraded fibers were retained with

A. Stamboulis; C. A. Baillie; T. Peijs

2001-01-01

292

Sterol content in sunflower seeds ( Helianthus annuus L.) as affected by genotypes and environmental conditions  

Microsoft Academic Search

Phytosterols play essential roles in many plant cell mechanisms. They are of industrial interest since, as part of the diet, they can reduce low density lipoprotein cholesterol. An increase in plant sterol contents, by improved crop varieties or crop management, could help to answer industrial demands and also to develop environmentally friendly extraction methods. The aim of this study was

Jane Roche; Marion Alignan; Andrée Bouniols; Muriel Cerny; Zephirin Mouloungui; Félicity Vear; Othmane Merah

2010-01-01

293

EFFECTS OF COAL MINING TO THE ENVIRONMENTAL CONDITIONS OF THE EAST BORSOD BASIN  

Microsoft Academic Search

To the NE of Miskolc city in the hilly foreground (East-Borsod coal basin) of the Bükk Mountains made up mainly of Miocene molasse sediments, Ottnangian-Karpathian brown coal deposits have been under exploitation for almost 200 years (Fig. 1). Therefore we tried to estimate the spatial extent of surface subsidence induced by headings and to measure environmental effects of the waste

L. SÜT?; M. KOZÁK; Z. PÜSPÖKI

294

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...

295

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...

296

Environmental conditions in beef deep-bedded monoslope facilities: a descriptive study  

Technology Transfer Automated Retrieval System (TEKTRAN)

There has been increased interest in feeding cattle in enclosed beef deep-bedded mono-slope facilities (BDMF). Characterization of environmental factors impacting odor and gas emissions, nutrient excretion, and pathogens is needed to develop recommendations for management of BDMF. The objectives of...

297

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...

298

Effects of estuarine environmental conditions on population dynamics of young-of-the-year gulf menhaden  

Microsoft Academic Search

Environmental factors, primarily river discharge and winter temperatures, are strongly correlated with growth and survival of young-of-the-year gulf menhaden Brevoortia patronus in Fourleague Bay, Louisiana, USA. Gulf menhaden were found in highest abundance from February to November. They first use marsh creeks and then in early summer they migrate out into deeper open bay areas where they remain until late

Linda A. Deegan

1990-01-01

299

Spatial and temporal variations of photsynthetic parameters in relation to environmental conditions in coastal waters of the northern Gulf of Mexico  

SciTech Connect

Eight cruises in the northern Gulf of Mexico made an effort to characterize temporal and spatial variability in parameters of the photosynthesis-irradiance saturation curve and to relate the observed variations to environmental conditions (temperature, salinity, nutrients, mixed layer depth, attenuation coefficient, and daily photosynthetically available radiation). Experiments to examine the importance of diel variation in upper mixed layer populations, both river plume and shelf-slope populations, were conducted in July-August 1990 and March 1991. In conclusion, relationships between P-I parameters and environmental variable in the region of study were significant in some cases, but variation between cruises made it difficult to generalize. The authors attributed this variation to the physically dynamic characteristics of the region and the possible effects of variables that were not included in the analysis such as species composition. Our findings do support the view that a limited set of observations may be adequate to characterize P-I parameter distributions in a given region within a restricted period of time. 62 refs., 8 figs., 8 tabs.

Lohrenz, S.E. [Univ. of Southern Mississippi, Stennis Space Center, MS (United States); Fahnenstiel, G.L. [Great Lakes Environmental Research Lab., Ann Arbor, MI (United States); Redalje, D.G. [Univ. of Southern Mississippi, Stennis Space Center, MS (United States)

1994-12-01

300

Characterisation of photovoltaic modules based on thin film solar cells in environmental operating conditions of Algerian Sahara  

NASA Astrophysics Data System (ADS)

This paper summarizes the electrical and thermal characterizations of thin film PV modules based on amorphous triple junctions (3J: a-Si) and Copper Indium Selenide (CIS) thin film solar cells. Tests are operated in outdoor exposure and under natural sunlight of Ghardaia, Algeria) as specific desert climate environment, characterized by high irradiation and temperature levels. Data acquired from Environmental Operating Conditions (EOC) was converted into solar module output characteristics at Standard Test Conditions (STC) by using three method suggested by Anderson and Mermoud as well as the equations already standardized as IEC 60891. Then, based on the investigation results of the conversion equations, differences among the converting methods (range of application, specificity of solar cell material, and experimental test conditions) were studied.

Agroui, K.; Hadj Mahammed, I.; Hadj Arab, A.; Belghachi, A.

2008-08-01

301

Are yolk androgens adjusted to environmental conditions? A test in two seabirds that lay single-egg clutches.  

PubMed

It is widely believed that female birds strategically allocate androgens to yolk in the manner that best equips offspring for feeding conditions during their development. Because most avian studies have focused on multi-egg clutch species, and interpreted results within the framework of sibling competition, we still know little about how yolk androgens might be allocated in direct response to environmental conditions. Most oceanic birds are long-lived and lay single-egg clutches, and their breeding success is tightly linked to highly variable marine production. That combination: a variable breeding environment, long lives, and single-egg clutches, makes oceanic birds good subjects to test hypotheses about yolk androgen allocation strategies. We measured concentrations of two yolk androgens, androstenedione (A4) and testosterone (T), in the single-egg clutches laid by early-laying Cassin's (Ptychoramphus aleuticus) and rhinoceros (Cerorhinca monocerata) auklets at Triangle Island, British Columbia, Canada, in 2002-2004. Environmental conditions including sea-surface temperatures and the timing and intensity of marine primary production varied over the 3 years, and in response, both the timing and success of seabird breeding varied. As in other avian species, concentrations of A4 and T varied markedly among individual eggs in both species (by factors of 3-8), yet contrary to expectation, little of the variation could be attributed to year effects. The high interindividual variation and the lack of interannual variation suggest a non-adaptive explanation for yolk androgen deposition relative to environmental conditions in these species. PMID:18577385

Addison, BriAnne; Benowitz-Fredericks, Z Morgan; Hipfner, J Mark; Kitaysky, Alexander S

2008-08-01

302

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

303

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 nmol H2O2 (m3 air)-1 in December to 3.81 nmol H2O2 (m3 air)-1 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.

2014-02-01

304

Evaluation of the Environmental Impact of different Lubrorefrigeration Conditions in Milling of ?-TiAl Alloy  

Microsoft Academic Search

\\u000a Conventional manufacturing techniques have not been subject to much scrutiny by industrial ecologist to date. The implementation\\u000a of environment-friendly methodologies in metal cutting is, consequently, of considerable direct economic, social and technological\\u000a importance. This paper aims to analyze the milling operation of a non conventional material such as ?-TiAl alloy from an environmental\\u000a point of view, taking into account the

Giovanna Rotella; Paolo Claudio Priarone; Stefania Rizzuti; Luca Settineri

305

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

306

Mite growth on fungus under various environmental conditions and its potential application to biofilters  

Microsoft Academic Search

The effects of relative humidity, temperature, pH and vapor-phase toluene concentration on Tyrophagus\\u000a putrescentiae growth on Cladophialophora sp. were tested in controlled environmental chambers. It was observed that the mites were able to reproduce readily at relative\\u000a humidities between 90% and 97% as well as on porous perlite support material pre-soaked in nutrient media of pH 2.5, 4 and\\u000a 7.

J. R. Woertz; K. A. Kinney; N. J. R. Kraakman; W. N. M. van Heiningen; M. H. A. van Eekert; J. W. van Groenestijn

2002-01-01

307

Mite growth on fungus under various environmental conditions and its potential application to biofilters  

Microsoft Academic Search

The effects of relative humidity, temperature, pH and vapor-phase toluene concentration on Tyrophagus putrescentiae growth on Cladophialophora sp. were tested in controlled environmental chambers. It was observed that the mites were able to reproduce readily at relative humidities between 90% and 97% as well as on porous perlite support material pre-soaked in nutrient media of pH 2.5, 4 and 7.

J. R. WOERTZ; K. A. KINNEY; N. J. R. KRAAKMAN; W. N. M. VAN HEININGEN; M. H. A. VAN EEKERT; J. W. VAN GROENESTIJN

2002-01-01

308

Determination of the optimal culture conditions for detecting thermophilic campylobacters in environmental water  

Microsoft Academic Search

This study evaluated alternative protocols for culturing thermophilic campylobacters in environmental water. All samples were filtered through a sterile 0.45?m pore-size membrane, which was then incubated in Preston enrichment broth. Four variables were compared: water sample volume (2000mL vs. 500mL), enrichment broth volume (25mL vs. 100mL), enrichment incubation duration (24h vs. 48h), and number of enrichment passages (one vs. two).

Simon Lévesque; Karen St-Pierre; Eric Frost; Robert D. Arbeit; Sophie Michaud

2011-01-01

309

Introducing a conditional 'Willingness to Pay' index as a quantifier for environmental impact assessment  

NASA Astrophysics Data System (ADS)

The optimal concentration Copt of a pollutant in the environment can be determined as an equilibrium point in the trade off between (i) environmental cost, due to impact on man/ecosystem/economy, and (ii) economic cost for environmental protection, as it can be expressed by Pigouvian tax. These two conflict variables are internalized within the same techno-economic objective function of total cost, which is minimized. In this work, the first conflict variable is represented by a Willingness To Pay (WTP) index. A methodology is developed for the estimation of this index by using fuzzy sets to count for uncertainty. Implementation of this methodology is presented, concerning odor pollution of air round an olive pomace oil mill. The ASTM E544-99 (2004) 'Standard Practice for Referencing Suprathreshold Odor Intensity' has been modified to serve as a basis for testing, while a network of the quality standards, required for the realization/application of this 'Practice', is also presented. Last, sensitivity analysis of Copt as regards the impact of (i) the increase of environmental information/sensitization and (ii) the decrease of interest rate reveals a shifting of Copt to lower and higher values, respectively; certain positive and negative implications (i.e., shifting of Copt to lower and higher values, respectively) caused by socio-economic parameters are also discussed.

Batzias, Fragiskos; Kopsidas, Odysseas

2012-12-01

310

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 ...

311

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

312

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

313

Robust vehicle detection under various environmental conditions using an infrared thermal camera and its application to road traffic flow monitoring.  

PubMed

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

314

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

315

Physiological responses of a rodent to heliox reveal constancy of evaporative water loss under perturbing environmental conditions.  

PubMed

Total evaporative water loss of endotherms is assumed to be determined essentially by biophysics, at least at temperatures below thermoneutrality, with evaporative water loss determined by the water vapor deficit between the animal and the ambient air. We present here evidence, based on the first measurements of evaporative water loss for a small mammal in heliox, that mammals may have a previously unappreciated ability to maintain acute constancy of total evaporative water loss under perturbing environmental conditions. Thermoregulatory responses of ash-grey mice (Pseudomys albocinereus) to heliox were as expected, with changes in metabolic rate, conductance, and respiratory ventilation consistent with maintaining constancy of body temperature under conditions of enhanced heat loss. However, evaporative water loss did not increase in heliox. This is despite our confirmation of the physical effect that heliox augments evaporation from nonliving surfaces, which should increase cutaneous water loss, and increases minute volume of live ash-grey mice in heliox to accommodate their elevated metabolic rate, which should increase respiratory water loss. Therefore, mice had not only a thermoregulatory but also a hygroregulatory response to heliox. We interpret these results as evidence that ash-grey mice can acutely control their evaporative water loss under perturbing environmental conditions and suggest that hygroregulation at and below thermoneutrality is an important aspect of the physiology of at least some small mammals. PMID:25163919

Cooper, Christine Elizabeth; Withers, Philip Carew

2014-10-15

316

Environmental Research for Art Conservation and Assessment of Indoor Conditions Surrounding Cultural Objects  

Microsoft Academic Search

This paper describes the results and conclusions of research directed towards the development and evaluation of a chemical\\u000a sensor which would provide information on the quality of indoor environments surrounding cultural objects. In our case these\\u000a objects were paintings housed in major European galleries and the main objective is their preservation through an improved\\u000a understanding of their microenvironment. The concept

M. Odlyha; N. S. Cohen; R. Campana; G. M. Foster

1999-01-01

317

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

318

Results on the survival of cryptobiotic cyanobacteria samples after exposure to Mars-like environmental conditions  

NASA Astrophysics Data System (ADS)

Tests on cyanobacteria communities embedded in cryptobiotic crusts collected in hot and cold deserts on Earth were performed under Mars-like conditions. The simulations were realized as a survey, to find the best samples for future research. During the tests organisms have to resist Mars-like conditions such as atmospheric composition, pressure, variable humidity (saturated and dry conditions) and partly strong UV irradiation. Organisms were tested within their original habitat inside the crust. Nearly half of the cryptobiotic samples from various sites showed survival of a substantial part of their coexisting organisms. The survival in general depended more on the nature of the original habitat and type of the sample than on the different conditions they were exposed to. The best survival was observed in samples from United Arab Emirates (Jebel Ali, 25 km SW of Dubai town) and from Western Australia (near the South edge of Lake Barley), by taxa: Tolypothrix byssoidea, Gloeocapsopsis pleurocapsoides, Nostoc microscopicum, Leptolyngbya or Symploca sp. At both places in salty desert areas members of the Chenopodiaceae family dominated among the higher plants and in the cryptobiotic crust cyanobacterial taxa Tolypothrix was dominant. These organisms were all living in salty locations with dry conditions most of the year. Among them Tolypothrix, Gloeocapsopsis and Symploca sp. were tested in Mars simulation chambers for the first time. The results suggest that extremophiles should be tested with taken into account the context of their original microenvironment, and also the importance to analyse communities of microbes beside single organisms.

de Vera, J.-P.; Dulai, S.; Kereszturi, A.; Koncz, L.; Lorek, A.; Mohlmann, D.; Marschall, M.; Pocs, T.

2014-01-01

319

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

320

Characterizing photochemical transformation of aqueous nC60 under environmentally relevant conditions.  

PubMed

Engineered nanomaterials may undergo transformation upon interactions with various environmental factors. In this study, photochemical transformation of aqueous nC60 was investigated under UVA irradiation. nC60 underwent photochemical transformation in the presence of dissolved O2, resulting in surface oxygenation and hydroxylation as demonstrated by XPS and ATR-FTIR analyses. The reaction followed a pseudo-first order rate law with the apparent reaction rate constant of 2.2 x 10(-2) h(-1). However, the core of the nanoparticles remained intact over 21 days of irradiation. Although no mineralization or dissolution of nC60 was observed, experiments using fullerol as a reference fullerene derivative suggested likely dissolution and partial mineralization of nC60 under long-term UVA exposure. Aquatic humic acid reduced nC60 transformation kinetics presumably due to scavenging of reactive oxygen species. Results from this study imply that photochemical transformation is an important factor controlling nC60 physical and chemical properties as well as its fate and transport in the natural aqueous environment. In addition, changes in nC60 surface chemistry drastically reduced C60 extraction efficiency by toluene, suggesting that the existing analytical method for C60 may not be applicable to environmental samples. PMID:20337472

Hwang, Yu Sik; Li, Qilin

2010-04-15

321

Proper housing conditions in experimental stroke studies—special emphasis on environmental enrichment  

PubMed Central

Environmental enrichment provides laboratory animals with novelty and extra space, allowing different forms of multisensory stimulation ranging from social grouping to enhanced motor activity. At the extreme end of the spectrum, one can have a super-enriched environment. Environmental enrichment is believed to result in improved cognitive and sensorimotor functions both in naïve rodents and in animals with brain lesions such as those occurring after a stroke. Robust behavioral effects in animals which have suffered a stroke are probably related not only to neuronal plasticity in the perilesional cortex but also in remote brain areas. There is emerging evidence to suggest that testing restorative therapies in an enriched environment can maximize treatment effects, e.g., the perilesional milieu seems to be more receptive to concomitant pharmacotherapy and/or cell therapy. This review provides an updated overview on the effect of an enriched environment in stroke animals from the practical points to be considered when planning experiments to the mechanisms explaining why combined therapies can contribute to behavioral improvement in a synergistic manner. PMID:25870536

Mering, Satu; Jolkkonen, Jukka

2015-01-01

322

Droplet-turbulence interactions in sprays exposed to supercritical environmental conditions  

NASA Technical Reports Server (NTRS)

The goal of this research was to experimentally characterize the behavior of droplets in vaporizing sprays under conditions typical of those encountered in high pressure combustion systems such as liquid fueled rocket engines. Of particular interest are measurements of droplet drag and lift, droplet dispersion, droplet heating, and droplet vaporization under both subcritical and supercritical conditions. A summary of the major accomplishments achieved during the period from June 1990 through June 1993, a brief description and status report on five research areas, which were directly or indirectly supported by this grant, and a list of publications and personnel associated with this research is included.

Santavicca, Domenic A.

1993-01-01

323

Scratch Behavior of Multiphase Styrenic Copolymers and Effects of Environmental Conditioning  

E-print Network

100, and ASA1000 in dry conditions at scratch speed of 1 mm/s. ............................................................. 34 x Figure 15. Coefficient of friction comparison for model systems. .................................. 36 Figure 16.... .......................................................................................................... 93 Figure 37. Mechanical properties of ASA100, ABS100, and ASA1000 before and after annealing. ................................................................................................. 94 Figure 38. Coefficient of friction comparison...

Moghbelli, Ehsan

2014-09-05

324

Durability studies of montmorillonite clay filled epoxy composites under different environmental conditions  

Microsoft Academic Search

Even though fiber reinforced polymer (FRP) composites are used in many applications, their integrity overtime is still unknown and remains a major concern. Due to inherent viscoelastic nature of polymers and their composites, exposure to elevated temperature and moist conditions results in matrix cracking, plasticization, and interfacial debonding and so on resulting in premature failure of composite structures. Researcher have

S. Zainuddin; M. V. Hosur; Y. Zhou; Ashok Kumar; S. Jeelani

2009-01-01

325

Variability in the Environmental Factors Driving Evapotranspiration from a Grazed Rangeland during Severe Drought Conditions  

E-print Network

: meteorological or climato- logical drought, agricultural drought, hydrological drought, and socioeconomic drought;Agricultural drought is defined as a period during which there is insufficient soil moisture to meet the need Severe Drought Conditions JOSEPH G. ALFIERI* AND PETER D. BLANKEN Department of Geography, University

Blanken, Peter D.

326

ForEnvironmentalManagementofMilitaryLands Land Condition-Trend Analysis  

E-print Network

of an earlier format to MS Access 2000 is an easy process. Be aware that once converted, the database may MS Access version, maintain a copy. 1) Open the current MS Access version. Select the database Using MS Access to Analyze Land Condition-Trend Analysis Data A Beginner's Guide By Christine Bern

327

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

328

Effect of environmental conditions on observed, modeled, and assimilated sea ice motion errors  

Microsoft Academic Search

Previous evaluations of ice motion have primarily consisted of comparisons with in situ observations and general sensitivity studies with wind speed and direction. An assimilation framework allows the quality of ice motions to be studied as an explicit function of model and model forcing parameters. Here we investigate the effects of local conditions on remotely sensed, modeled, and assimilated motions.

Walter N. Meier; James A. Maslanik

2003-01-01

329

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

330

ASSESSMENT OF FUNGAL GROWTH ON CEILING TILES UNDER ENVIRONMENTALLY CHARACTERIZED CONDITIONS  

EPA Science Inventory

The paper discusses investigation of the impact of the building environment on the ability of building materials to support microbial growth, using static chambers with defined relative humidity, temperature, and light conditions. he ability of fungi to grow on materials is well ...

331

Acquiring an attacking forehand drive: the effects of static and dynamic environmental conditions.  

PubMed

Two groups of 10 novice subjects each were trained to perform attacking forehand drives in table tennis and land the balls as fast and as accurately as possible onto a target on the opposite side of the net under two different training conditions. Under the static training condition, the balls were to be struck from a constant position, and under the dynamic training condition, balls approached the subjects in a normal way. Both groups were tested under dynamic conditions prior to and after four days of training, during which they received 1,600 practice trials. Both groups of subjects were shown to increase the number of balls that landed on the target, and learning was also evident from an increased consistency of the direction of travel of the bat at the moment of ball/bat contact. However, no increase in consistency was found for the location of the bat at the moment of ball/bat contact and for the movement times. Thus, learning can occur in the absence of externally generated time-to-contact information, but this is not due to the establishment of a consistent movement form. Learning appears to progress from control at the moment of ball/bat contact backward, toward the moment of initiation. PMID:1925055

Bootsma, R J; Houbiers, M H; Whiting, H T; van Wieringen, P C

1991-09-01

332

Challenges for Physical Characterization of Silver Nanoparticles Under Pristine and Environmentally Relevant Conditions  

EPA Science Inventory

The reported size distribution of silver nanoparticles (AgNPs) is strongly affected by the underlying measurement method, agglomeration state, and dispersion conditions. A selection of AgNP materials with vendor-reported diameters ranging from 1 nm to 100 nm, various size distrib...

333

Degradation of methylene blue: optimization of operating condition through a statistical technique and environmental estimate of the treated wastewater.  

PubMed

FeO(x)-MoO(3)-P(2)O(5) (x=1 or 1.5) composite catalyst was prepared by solid reaction method and characterized by X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Its catalytic activities on degradation of a heteropolyaromatic dye, methylene blue (MB), were also investigated under mild condition. In order to determine the optimum operating condition, the orthogonal experiments were devised. And the results revealed that initial concentration of MB was the key factor that affected the decoloration, while the catalysts dose has an insignificant effect. Environmental estimation was also done and the results showed that the treated wastewater have little influence on plant growth and could totally be applied to irrigation. PMID:17868986

Zhuo, Qiongfang; Ma, Hongzhu; Wang, Bo; Fan, Fang

2008-05-01

334

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

335

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

336

The Wording of Conclusions in Relational Reasoning  

ERIC Educational Resources Information Center

Literature on relational reasoning mainly focuses on the performance question. It is typically argued that problem difficulty relies on the number of ''mental models'' compatible with the problem. However, no study has ever investigated the wording of conclusions that participants formulate. In the present work, we analyze the relational terms…

Van der Henst, Jean-Baptiste; Schaeken, Walter

2005-01-01

337

Tourism in the Amazon: conclusions and solutions  

Microsoft Academic Search

Purpose – The paper aims to present answers to the strategic question: “Does sustainable tourism offer solutions for the protection of the Amazon rainforest?” It also aims to capture the essence of conclusions of eight papers written by 11 tourism experts to the Worldwide Hospitality and Tourism Themes (WHATT) issue on tourism in the Amazon, South America. Design\\/methodology\\/approach – The

Donald Sinclair

2010-01-01

338

Integrated measures for preservation, restoration and improvement of the environmental conditions of the Lagoon Olho d'Agua basin.  

PubMed

The Lagoon Olho d'Agua in Pernambuco State, Northeast Brazil has received increasing environmental concern due to significant stress from pollution in the catchment. The existing environmental problems are the result of great pressure from a broad range of human activities, especially in the last 10 years. Serious pollution exists mainly from some industrial and urban activities, which increased intensively after the eighties. There is a strong social and economical pressure for housing and construction near the lagoon, due to the available land nearby beaches and estuarine zone, and recently by growing tourism activities. Uncontrolled land use by low-income communities and the pressure for construction by developers have led to landfilling and to deterioration of water quality in the lagoon catchment. Improvement of the environmental conditions in the catchment needs integrated measures. Guidelines and some specific actions involving several institutions have been established and refer to sanitation and urban infrastructure as the main priorities. A main target is the construction of low-cost sewage system with smaller and decentralised treatment plants. PMID:11485222

Florencio, L; Kato, M T; de Lima, E S

2001-06-01

339

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

340

A comparison of modern and fossil ostracods from Frasassi Cave system (northeastern Apennines, Italy) to infer past environmental conditions  

NASA Astrophysics Data System (ADS)

Cave water and sediments from an extensive sulfidic, chemioautotrophic subterranean ecosystem in the hypogenic karst complex of Frasassi (northeastern Apennines of Italy) was analysed for modern and fossil ostracode assemblages. 22 extant and 16 extinct ostracode species make of this continental sulphidic ecosystem one of the richest worldwide. Both modern and fossil assemblages show the expected pattern of species diversity after the simulation procedure for taxonomic distinctness, which indicates no major extinction events since the Pleistocene. Extant species display patchy distribution according to habitat heterogeneity within the sulphidic environment. Fossil assemblages from a 3 m thick fluvial deposit trapped near the entrance of the Caverna del Carbone (CDC) at about 30 m above present river level, and a fine sand deposit resting at about the same elevation in Sala Duecento (SDS) within the Grotta Grande del Vento preliminarily dated with OSL at 111±17 ka are being investigated. The former deposit has yet to be dated but it represents probably a normal stratigraphic succession spanning a few tens of kyr, which was deposited when the cave entrance was at the reach of fluvial flooding, potentially recording the transition from the last interglacial Riss-Würm to the glacial Würm. Sediment samples from the SDS site yielded an ostracode assemblage represented by 12 species with a d18O signature of -5‰ and a well-diversified palinoflora assemblage indicating a transitional condition between steppe and temperate forest. The top sediment from the CDC site is characterized by a less diversified ostracode assemblage represented by 8 species, d18O of -3‰, and a poorly diversified palinoflora dominated by herbaceous plants and lesser pines, indicating a colder environment in the early stage of the last glacial. Additional information on the geometric morphometry approach of B-splines method applied to extant and fossil specimens of the hypogean Mixtacandona ostracode was used to identify microevolutionary patterns and environmentally cued variation. Analyses indicate the presence of one morphotype of a new species A of the group Mixtacandona riongessa, and three distinctive morphotypes of a species B of the group M. laisi-chappuisi occurring in stratigraphically distinct fluvial-cave sediments. Apparent difference in the disparity level between these species could be associated with their survival in different environmental conditions. Species A is found nowadays living exclusively in sulphidic cave waters, and was present in the system since at least the end of the last interglacial. The extraordinary high taxonomic and morphological diversity of ostracods reflects in situ evolutionary processes that have occurred under the cumulative effect of high environmental energy availability of subterranean sulphidic ecosystems, heterogeneous environmental conditions, and spatial and temporal isolation.

Iepure, S.; Namiotko, T.; Montanari, A.; Brugiapaglia, E.; Mainiero, M.; Mariani, S.; Fiebig, M.

2012-04-01

341

Investigations of chemical fraction of Co and Ni in industrial fly ash and mobility of metals in environmental conditions.  

PubMed

The quantitative evaluation of chemical fraction of Co and Ni in the industrial fly ash by methods of five step sequential extraction was carried out in order to characterize metal mobility in environmental conditions. The research involved (i) water-soluble (pH=7), (ii) acid-soluble (pH=5), (iii) oxide, (iv) sulfide and (v) residue metal fractions. It was discovered, that the total extraction of the studied metals from fly ash to solutions take place in the following quantities Co - 35.5 and Ni - 153.0mgkg(-1). The investigations of chemical fractions proved that the subject metals occur mainly in fly ash as: oxide (Co - 7.0, Ni - 28.5mgkg(-1)) and residue (Co - 11.5, Ni - 42.5mgkg(-1)) as well as sulfide (Co - 8.5, Ni - 46.5mgkg(-1)). Low concentrations of metals for water-soluble fraction (Co - 0.7, Ni - 1.2mgkg(-1)) and acid-soluble fraction (Co - 4.5, Ni - 23.5mgkg(-1)) were observed. The fractions of Co and Ni leachable from the ash in environmental conditions contain: 24.0% (Co) and 23.3% (Ni) of metal total amount in the industrial fly ash. The obtained mobility parameter of Co and Ni can be applied to estimate the concentration increase of mobile and hardly mobile forms of these metals in soil polluted with the ash. PMID:17150241

Soco, Eleonora; Kalembkiewicz, Jan

2007-02-01

342

Changes caused by genotype and environmental conditions in beta-glucan content of spring barley for dietetically beneficial human nutrition.  

PubMed

Over the 5-year period (2000-2004), a significantly higher beta-glucan content was detected in the waxy varieties Washonubet, Wabet, and Wanubet (6.8-7.6%) and lines formed by crossing these varieties with malting varieties (5.8-7.1%). Conversely, the non-waxy hulled malting-type varieties Kompakt (4.0%) and Krona (4.3%) had significantly lower contents of beta-glucan. The observations also showed that concentrations of beta-glucans in 2000-2004 were significantly affected not only by varieties, but also environmental conditions in the growing periods and interactions of these two factors. Higher precipitation during the flowering time and grain filling period and lower temperatures during the flowering time in 2002 had negative effects on concentration of beta-glucans. Conversely, drier and warmer weather in 2003 enhanced the content of beta-glucans. The results show that it is possible to increase the content of beta-glucan in spring barley grain by implementing selective breeding practices. Compared to the parental malting varieties, the mean content of beta-glucans in F(4)-F(8) generations was increased by 1.8 and 2.0% by recombination in lines Kompakt x Wabet and Wanubet x Krona, respectively. Significant effect of environmental conditions and their interactions with varieties indicated the necessity to assess standard qualities of barley as a food material. PMID:18551369

Ehrenbergerová, J; Brezinová Belcredi, N; Psota, V; Hrstková, P; Cerkal, R; Newman, C W

2008-09-01

343

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

344

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

345

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

346

Monitoring and Prevention of Anemia Relying on Nutrition and Environmental Conditions in Sports  

PubMed Central

Conflict of interest: none declared. Introduction Anemia is a blood disorder characterized by abnormally low levels of healthy red blood cells or reduced hemoglobin, the iron-bearing protein in red blood cells that delivers oxygen to tissues throughout the body. The most common symptoms of this disorder are fatigue, weakness and, in extreme cases, shortness of breath or palpitations, or you may have no symptoms at all. Sports anemia is a term loosely applied to a least three different conditions: hemodilution, iron deficiency anemia and foot-strike anemia. Not exclusive to athletes, iron deficiency anemia occurs most often among women who may lose more iron each month when they menstruate than they take in. Material and Methods Therefore, we examined its effect on the physical condition of female athletes. Several years (since 2010th until 2012th), we studied how anemia among girls (pioneers, juniors and seniors categories) that are involved in sports (women’s soccer, volleyball and handball) in Rasina’s district (Serbia), affecting their physical fitness. When their trainers approach to us, complaining that they have players who are great, so extraordinary talents, but by no means able to withstand more than twenty minutes in the game, we suggest them to perform laboratory tests. It was tested 134th female athletes. Results and Discussion Anemia was observed in 43. (9. pioneers, 19. juniors and 15. seniors). So, laboratory results showed that in these girls anemia causes poor sport condition. After that, the girls enhanced nutrition. Their diet consisted of iron supplements and vitamins. Altitude training was organized for them, also. After all these treatments, condition significantly improved. It was first time that trainers in Rasina’s district realizing significance of laboratory tests. PMID:24082840

Sacirovi?, Selim; Asotic, Jasminka; Maksimovic, Radmila; Radevic, Borislav; Muric, Benin; Mekic, Hasim; Biocanin, Rade

2013-01-01

347

Different effects of unexpected changes in environmental conditions on prepulse inhibition in rats and humans.  

PubMed

The reduction of the startle response to an auditory stimulus caused by the presentation of another stimulus of lower intensity closely preceding it, a phenomenon known as prepulse inhibition (PPI), can be modulated by changes in dopaminergic activity. Schmajuk, Larrauri, De la Casa, and Levin (2009) demonstrated that this dopaminergic modulation of PPI in rats can be influenced by manipulating the experimental context, specifically by introducing changes in the ambient lighting condition that include novel elements. In this paper we analyze the effects of introducing changes in context illumination on PPI in male rats (Experiment 1) and humans (Experiment 2). The results with rats showed a reduction of PPI when the illumination condition switched from dark to light, but not from light to dark. In the experiment with human participants the reduction of PPI occurred for both changes in illumination conditions. The animal experiment results are interpreted in terms of competing exploratory behavior that appear when the context is illuminated after the dark-light transition; while in the case of human participants a perceptual and/or attentional mechanism after both illumination transitions is proposed, which may result in a reduced processing of the prepulse and subsequent lower PPI. PMID:22504495

De la Casa, L G; Fernandez, A; Larrauri, J; Mena, A; Puentes, A; Quintero, E; Schmajuk, N

2012-06-25

348

Vertical and temporal variation in phytoplankton assemblages correlated with environmental conditions in the Mundaú reservoir, semi-arid northeastern Brazil.  

PubMed

The goal of this study was to analyse the vertical structure of the phytoplankton community at the Mundaú reservoir, located in the semi-arid region of northeastern Brazil, and to correlate it to environmental conditions over two distinct seasons, dry and rainy. Samples were collected bimonthly at eight depths in the dry and rainy season for analyses of the physical and chemical variables of the water, as well as density, abundance, dominance, species diversity index and equitability of the community. Analysis of variance (ANOVA-two way) was used to analyse the vertical and seasonal differences, and Canonical Correspondence Analysis (CCA) was used to assess associations between phytoplankton and environmental variables Cylindrospermopsis raciborskii (Woloszynska) Seenaya and Subba Raju was the only dominant species and Geitlerinema amphibium (C. Agardh) Anagnostidis, Merismopedia punctata Meyen and Synedra rumpens Kützing. Others six taxa were abundant in at least one of the samples. Distinct vertical distribution patterns were observed for the abundant taxa between depths and seasons. The cyanobacteria, with the exception of C. raciborskii, showed similar seasonal patterns, with higher densities in the dry season. The CCA showed a strong correlation between the density of the phytoplanktonic species and abiotic variables. The vertical changes in abundant taxa revealed distinct patterns regulated by the variation in the environmental factors that were directly linked to seasonality, with the success of one or more species being dependent on their life strategies and ecological needs. The present study restates the importance of environmental and seasonal factors for phytoplankton composition and distribution in a freshwater tropical reservoir through a vertical gradient. PMID:25627370

Lira, Gast; Moura, An; Vilar, McP; Cordeiro-Araújo, Mk; Bittencourt-Oliveira, Mc

2014-08-01

349

Microscopic study of surface degradation of glass fiber-reinforced polymer rods embedded in concrete castings subjected to environmental conditioning  

SciTech Connect

The surface degradation of glass fiber-reinforced polymer (GFRP) pultruded rods when embedded in concrete castings and subjected to environmental conditioning is discussed in this paper. Investigation of the degradation of the GFRP rods were performed using optical microscopy and scanning electron microscopy (SEM). Unidirectionally reinforced pultruded rods (6.3- and 12.7-mm diameters) containing E-glass fibers in polyester and vinylester matrices were conditioned at standard laboratory conditions (21 C, 65% relative humidity) or submerged in aqueous solutions (tap water) at 80 C for durations of 14 and 84 days. Observations of the surfaces and cross-sections of the rods by optical microscopy and SEM revealed a variety of degradation phenomena. Embedded hygrothermally conditioned rods were found to have developed surface blisters of different sizes and depths. SEM studies of the surface revealed degradation of the polymer matrix material and exposure and degradation of the fibers close to the surface of the rods. The rods with the vinylester resin matrix showed less extensive degradation than those with the polyester resin matrix; however, the degradation characteristics of the two types of rods appear to be similar.

Bank, L.C. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Civil and Environmental Engineering; Puterman, M. [Technion, Haifa (Israel). National Building Research Inst.

1997-12-31

350

Long-term changes in the seasonality of selected diatoms related to grazers and environmental conditions  

NASA Astrophysics Data System (ADS)

The decoupling of trophic interactions could be one of the severe consequences of climate warming in aquatic systems. The timing of phytoplankton blooms, in particular, can affect competition within the plankton community as well as food-web interactions with zooplankton and fish. Using long-term data from Helgoland Roads in the southern North Sea, we examine diatom seasonality, using three representative diatom species combined with environmental and copepod time series over the last four decades. The long-term annual abundances of Guinardia delicatula, Thalassionema nitzschioides and Odontella aurita exhibited interannual variations and dissimilar cyclic patterns during the time period under study (1962-2008). Of the three diatoms, G. delicatula showed a significant trend towards earlier bloom timings for 1962-2008 and a later decline of its abundance over time was found. Grazing and water transparency explained most of the bloom timing fluctuations of the diatoms considered. The annual timing of occurrences of each diatom species was correlated with their preceding concentrations. Earlier bloom timings occurred when autumn/winter concentrations were higher than average and later bloom timings occurred when autumn/winter concentrations were lower than average. Different environmental and predation variables related to the diatom bloom timings were found suggesting that climate warming might not affect the onset of the blooms of the three diatom species in the same manner. The results of the multiple linear regression analyses showed that the timings of decline of the three diatoms were mainly correlated with decreasing nutrient concentrations. Sunshine duration could prolong the duration of the blooms of T. nitzschioides and O. aurita provided that enough nutrients were available. In the case of G. delicatula, however, sunshine duration was negatively correlated with its end of the growth period. G. delicatula and T. nitzschioides showed later decreases in abundances under warmer spring and summer temperatures. Such species specific differences in the sensitivity to the forcing variables could lead to shifts in community structure and could ultimately have wider implications to the overall ecosystem health of the North Sea.

Schlüter, Merja H.; Kraberg, Alexandra; Wiltshire, Karen H.

2012-01-01

351

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

352

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

353

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

354

Impact of environmental conditions on the marine natural product bryostatin 1.  

PubMed

Marine Natural Products (MNPs), such as bryostatin 1, are exposed to a range of physical and chemical conditions through the life cycle of the host organism. These include exposure to sunlight, oxidizing and reducing agents, cation binding, and adsorption to reactive metal oxide surfaces. Using Fourier Transform-Ion Cyclotron Resonance (FT-ICR), Matrix Assisted Laser Desorption Ionization Mass Spectrometry (MALDI-MS), UV/Vis absorbance spectroscopy, and molecular modeling, we studied the impact of UV light, TiO2, I2, and reaction with FeCl3 on the structure of bryostatin 1. Our results demonstrate that natural conditions transform bryostatin to a number of structures, including one with a molar mass of 806 Da, which we have previously identified in the sediment collected from the Gulf of Mexico. To date, at least 20 different structures of bryostatin have been reported in the literature. This work suggests that these variations may be products of the chemical environment in which the bryozoa Bugula neritina resides and are not the result of genetic variations within Bugula. PMID:16835096

Manning, Thomas J; Rhodes, Emily; Land, Michael; Parkman, Render; Sumner, Brandy; Lam, Tukiet T; Marshall, Alan G; Phillips, Dennis

2006-05-20

355

Fine powder flow under humid environmental conditions from the perspective of surface energy.  

PubMed

The influence of humidity on surface energetics and flow behavior of fine pharmaceutical powders was investigated. Amorphous and crystalline fine powders with hydrophilic (Corn starch and Avicel PH105) and hydrophobic (ibuprofen) nature were considered for this study. The surface energy was determined using surface energy analyzer and flow behavior was measured in terms of unconfined yield stress (UYS) using a shear tester. The study showed that unlike hydrophobic ibuprofen powder, surface energy and flow of hydrophilic excipient powders were affected by relative humidity (RH). The Lifshitz-van der Waals dispersive (?(LW)) component of surface energy barely changed with varying RH for all pharmaceutical powders. For hydrophilic excipients, the specific component of surface energy (?(SP)) was found to increase with increasing RH. Furthermore, for these excipients, flow deterioration at elevated RH was observed due to increased capillary bridge formation. Detailed analysis showed that ?(SP) component of surface energy can be an effective indicator for flow behavior of fine powders under varying humid conditions. The present study also brought out the existence of different regimes of probable interparticle forces which dictate the bulk flow behavior of fine hydrophilic powder under humid conditions. PMID:25772418

Karde, Vikram; Ghoroi, Chinmay

2015-05-15

356

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

357

Transcriptional Response of Desulfovibrio vulgaris Hildenborough to Oxidative Stress Mimicking Environmental Conditions  

SciTech Connect

Sulphate-reducing bacteria are anaerobes readily found in oxic-anoxic interfaces. Multiple defence pathways against oxidative conditions were identified in these organisms and proposed to be differentially expressed under different concentrations of 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 sulphate-reducing bacteria are likely to encounter in natural habitats, and the global transcriptomic response was determined. 307 genes were responsive, with cellular roles in energy metabolism, protein fate, cell envelope and regulatory functions, including multiple genes encoding heat shock proteins, peptidases and proteins with heat shock promoters. Of the oxygen reducing mechanisms of D. vulgaris only the periplasmic hydrogen-dependent mechanism is up-regulated, involving the [NiFeSe]hydrogenase, formate dehydrogenase(s) and the Hmc membrane complex. The oxidative defence response concentrates on damage repair by metal-free enzymes. These data, together with the down regulation of the Fur operon, which restricts the availability of iron, and the lack of response of the PerR operon, suggest that a major effect of this oxygen stress is the inactivation and/or degradation of multiple metalloproteins present in D. vulgaris as a consequence of oxidative damage to their metal clusters.

Pereira, Patricia M.; He, Qiang; Xavier, Antonio V.; Zhou, Jizhong; Pereira, Ines A.C.; Louro, Ricardo O.

2008-03-12

358

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

359

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

360

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

361

Environmental education as preparation people for life in conditions of global changes imbalanced Nature  

NASA Astrophysics Data System (ADS)

The Regional Teacher Training Centre in Skierniewice is one of 49 public, accredited institutions in Poland. It is responsible for organizing of support of schools, institutions, networks of teachers and school managers for cooperation and self education, organizing and conducting forms of in-service training, giving methodological councils and disseminating examples of good practice. I present one example of how Environmental Education has been imparted to school students and their teachers through outdoor activities as part of the learning process. An Environmental Education Program, 'On Bolimov Nature Preserve Trails' has been organized regularly since 2001. The Bolimov Nature Preserve is a protected area in central Poland, situated between two agglomerations: capital city Warsaw to the East and industrial city Lodz to the West. It was established to protect an unique ecosystem on the Rawka River banks from human activity and harmful external factors. Pine tree forests, small streams, wetlands, glades are another elements of the park scenery. Walks on the park's trails are a great opportunity to see unique species of flora (more than 40 protected species and many endangered species on verge of extinction) and fauna. For teachers and students the Bolimov Nature Preserve offers educational lessons and events. The main activity is participation of students and teachers in group walk along trails of the park using various tools of orientation: maps, compasses and GPS. Along the paths they learn recognition of forms of terrain, identification of living species (using flora&fauna guides, magnifying glasses), measuring components of weather (using weather atlases, thermometers, anemometers) as well as preparation of soil profile. A survey is conducted after each such program. A statistical analysis of the survey data reveals that each year more and more students representing all levels of education from primary to upper secondary levels and their teachers are involved in this enterprise. For all participating in these walks it is great opportunity to observe how the Nature is functioning without much man-kind interference, pure, untouched and imbalanced. They can observe the untouched river banks, non regulated and meandering in its own way. They can recognize new species which are appearing every year on non cultivated glades, around overgrowing mid-forest lakes or on wetlands. They can observe traces of beavers' work: dams, cut trees, beaver lodges built on small streams flowing through the forest. Also the nests of unique black storks are possible to see. They can measure and observe how the climate is changing and how it varies in different ecosystems (forest, glade, river, wetlands) untouched by humans. They can learn that Nature can exists itself without human interference and it becomes more diverse and rich. It is necessary to teach students to the correct understand the changes in Nature, explain how are changing the living and non-living nature, what is the man-made imbalances of Nature and also how to prepare people for climate change. Each year almost 700 - 1000 students and about 100 teachers participate in this ecological learning process. Outdoor education, observations and experimentations are crucial issues of national school curricula referring to all educational levels which is successfully addressed by this program.

Dabrowska, A. E.

2013-12-01

362

Distribution of Recent Benthic Foraminifera and its Environmental Conditions of Karaikal, Central Coast of Tamil Nadu  

NASA Astrophysics Data System (ADS)

Foraminifera have been successful inhabitants of every aquatic environment from deep oceans to brackish water lagoons, estuaries and even rarely in freshwater streams, lakes etc. offshore region of Karaikal the present study has been taken up to enhance the existing knowledge on foraminifera of central coast of Tamil Nadu, India. Totally 21 sediment and water samples were collected from the offshore region. The depth of sample collection in offshore area ranges from 1.5 m to 12 m. Standard procedures adopted for the evaluation of different environmental parameters are incorporated. A total of 33 foraminiferal taxa belonging to 17 genera, 12 subfamilies, 14 superfamilies, and 4 suborders have been identified. In Karaikal , the mean size of the sediments on the foreshore ranges from 1.51 to 2.95 ? indicating the predominance of fine sediments (80-85%) with an admixture of medium-grained sands. Calcium carbonate content is generally found to be directly proportional to the population size in both the estuary and shelf area. It clearly indicates that due to the erosional activities whatever sediments deposited near the Arasalar river in that region are transported to the marine region and were drifted towards northern direction by longshore current, hence the deposition of carbonate in the sediments shows negative correlation. Due to strong high energy environment the current action is more in this region the juvinile forms of A. beccarri, A.tepida, A. dendata, E. crispum, P. calar, and P. nipponica only withstand and the other species are absent. The Correlation between Living vs Dead, Dead Vs Calcium carbonate, Salinity Vs living, Organic matter Vs Living, Organic matter Vs Carbonate content shows positive correlation for all the samples like LT, HT, Beach, River, and Offshore. Even though, all the ecological parameters having good correlation with foraminifera, but the distribution are very less in the study area. M.RAJA Dept.of.Geology University of Madras Chennai,Tamilnadu, INDIA.

Murugan, R.; Gandhi, S.

2013-05-01

363

An explosive convective cloud system and its environmental conditions in MJO initiation observed during DYNAMO  

NASA Astrophysics Data System (ADS)

An unusually large, explosive convective cloud system was observed over the equatorial Indian Ocean on 28 November 2011 during the DYNAMO (Dynamics of the Madden-Julian Oscillation (MJO)) field campaign. The significance of this mesoscale convective system (MCS) is its size and explosive development of cold cloud tops (-96°C) during the initiation of a strong MJO event. Observations from the DYNAMO show that the large MCS developed within a well-defined synoptic-scale cyclonic circulation associated with an equatorial low-pressure system with characteristics of a mixed Rossby-gravity wave that dominated the flow in the DYNAMO array. Prior to the development of the MCS, the equatorial flow was characterized by strong vertical wind shear with low-level westerlies and upper level easterlies. A region of decreased wind shear and enhanced upper level divergence emerged concurrently with the passage of the westward moving mixed Rossby-gravity wave-related low-pressure system and convective activity. In situ sounding observations suggest that widespread deep convection upstream of the large MCS may have contributed to the reduction of the upper level easterlies through vertical momentum transport and convective outflow. Both the reduction in vertical wind shear and enhanced low-level convergence induced by the equatorial low-pressure system created a favorable environment for the rapid development of the MCS. This study examines the development of the MCS and the associated synoptic-scale equatorial low-pressure system within the large-scale MJO circulation using in situ sounding observations from DYNAMO, which provide new insights into the interaction between convection and environmental flow during MJO initiation over the equatorial Indian Ocean.

Judt, Falko; Chen, Shuyi S.

2014-03-01

364

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

365

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

366

Environmental conditions and characteristics of ice supersaturated regions from global field campaigns  

NASA Astrophysics Data System (ADS)

Cirrus clouds play important roles in the Earth's climate and weather and their influences extend from the global scale (~30% coverage of the Earth's surface) to the microscale (e.g., interactions with aerosols). Cirrus cloud formation occurs in ice supersaturated regions (ISSRs), where the relative humidity with respect to ice (RHi) is greater than 100%. Recent observations show that cirrus clouds have a very small (~1 km) horizontal median length, yet the origin of such small scale structure is not known. The magnitude of cirrus clouds' radiative forcing is greatly influenced by cloud properties such as the coverage, thickness, ice crystal number concentration and size distribution. The microscale structure of ISSRs is critical for the microphysical processes in cirrus clouds, since the local conditions of ISSRs (e.g. temperature and RHi) influence the properties of ice crystals and their interactions with aerosols. However, the spatial structure of ISSRs and its controlling factors are still unknown below the mesoscale. To this end, we analyzed the spatial structure and environments of ISSRs — the prerequisite stage of cirrus cloud formation — based on in situ, high resolution (1 Hz, ~230 m) aircraft observations from 87°N to 67°S from five different field campaigns that span the tropics, mid-latitudes, and polar regions: NSF START08, HIPPO 1-5, PREDICT, TORERO, and DC3 field campaigns. By analyzing a large number (>7000) of individual case studies of ice supersaturated regions, we reveal the patchy nature of ISSRs with their median lengths being very small (~ 1 km) regardless of the location. The patchiness of ISSRs is found to largely correlate with water vapor (H2O) spatial heterogeneities, while the correlations with temperature (T) and vertical velocity (w) heterogeneities are much less dominant. The large influence of H2O heterogeneities on ISSR patchiness not only happens in supersaturated conditions but also extends to subsaturated conditions. The dominance of H2O over the spatial relative humidity field holds from the microscale (~230 m) to the mesoscale (~120 km) over various ranges of temperature (205-302K), water vapor (2-39,000 ppmv) and pressure (133-1,014 hPa). These findings suggest that H2O heterogeneities play crucial roles in determining the RHi spatial heterogeneities even before ISSRs are formed. Neglecting H2O heterogeneities in simplified ISSR evolution schemes results in different ISSR structures than those observed, which in turn changes the predicted properties of cirrus clouds.

Zondlo, M. A.; Diao, M.; Zhang, Q.; DiGangi, J.; O'Brien, A.

2012-12-01

367

Influence of environmental conditions on early development of the hydrothermal vent polychaete Alvinella pompejana.  

PubMed

Dispersal and colonisation processes at deep-sea vents are still not fully understood, essentially because early life stages of vent species remain unknown. The polychaete worm Alvinella pompejana forms colonies on chimney walls at East Pacific Rise vent sites where the temperature can frequently exceed 20 degrees C. In vitro studies in pressure vessels showed that the early embryos tolerate temperatures in a lower range (10-14 degrees C), suggesting that they would have to escape the colony to develop. Pressure vessels offer the advantage that each parameter can be independently controlled, but they do not simulate the more complex and dynamic conditions naturally encountered at vent sites. Accordingly, in addition to incubations in pressure vessels, we incubated embryos directly at a vent site, in different habitats along a gradient of hydrothermal influence. Embryos incubated on an adult A. pompejana colony where temperature and H(2)S concentrations were relatively high showed a very low survival rate and did not develop, whereas embryos incubated in a Riftia pachyptila clump environment with a lower hydrothermal signature, or at the base of the chimney where the influence of the hydrothermal activity was very weak, survived well and developed. Although the average temperature recorded in the A. pompejana colony was within the range tolerated by embryos (13 degrees C), frequent peaks above 20 degrees C were recorded. Estimated sulphide concentration at this site reached 200 mumol l(-1). Punctuated exposure to both high temperature and elevated sulphide levels probably explain the low survival of embryos within the A. pompejana colony. The in situ experiments further support the idea that embryos require conditions with moderate hydrothermal influence not generally found within an adult colony. However, as much more benign physicochemical conditions can be found within a few tens of cm of adult colonies, embryos do not necessarily have to leave their vent of origin to develop. Further analyses are needed to pinpoint the specific factors that affect the survival and development of embryos at vents. PMID:15802678

Pradillon, Florence; Le Bris, Nadine; Shillito, Bruce; Young, Craig M; Gaill, Françoise

2005-04-01

368

Stress corrosion cracking of austenitic stainless steel. Effect of environmental conditions on crack propagation  

SciTech Connect

In an investigation on macrobranching in austenitic stainless steel SUS304, crack propagation in the range of strong macrobranching was studied, and the crack propagation rate and crack shape in hot concentrated magnesium chloride solutions were determined. The following results were obtained: (1) in magnesium chloride solutions, macrobranching was observed at medium temperatures and concentrations; (2) specimens in which there was macrobranching exhibited local surface corrosion along the cracks, the transverse cracks branching at 60 directly beneath the surface; (3) the surface-crack length increased in proportion to the immersion time in the initial stages of propagation; (4) the transverse-crack depth increased exponentially with the immersion time; and (5) the relationship between the surface-crack length and the transverse-crack depth was dependent on experimental conditions.

Takemota, M.

1982-04-01

369

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

370

Release of pentachlorophenol from black carbon-inclusive sediments under different environmental conditions.  

PubMed

To investigate the feasibility of using black carbon (BC) in the control of hydrophobic organic contaminants (HOCs) in sediment, we added BCs from various sources (rice straw charcoal (RC), fly ash (FC) and soot (SC)) to sediment to create different BC-inclusive sediments and studied the release of pentachlorophenol (PCP) in the sediments under different condition. Different pH values had no obvious effect on the release of PCP in BC-inclusive sediment, but solid/liquid ratio, temperature, salinity and dissolved organic matter (DOM) content had significant influences on the release of PCP in all sediments except the RC-inclusive sediment. Adding 2% RC to sediment resulted in a 90% decrease in PCP release, which was a greater decrease than observed with FC- and SC-inclusive sediments. Therefore, from the standpoint of HOC release, the application of RC is feasible for organic pollution control in the water environment. PMID:22480941

Lou, Liping; Luo, Ling; Yang, Qiang; Cheng, Guanghuan; Xun, Bei; Xu, Xinhua; Chen, Yingxu

2012-07-01

371

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

372

The Eocene Arctic Azolla bloom: environmental conditions, productivity and carbon drawdown.  

PubMed

Enormous quantities of the free-floating freshwater fern Azolla grew and reproduced in situ in the Arctic Ocean during the middle Eocene, as was demonstrated by microscopic analysis of microlaminated sediments recovered from the Lomonosov Ridge during Integrated Ocean Drilling Program (IODP) Expedition 302. The timing of the Azolla phase (approximately 48.5 Ma) coincides with the earliest signs of onset of the transition from a greenhouse towards the modern icehouse Earth. The sustained growth of Azolla, currently ranking among the fastest growing plants on Earth, in a major anoxic oceanic basin may have contributed to decreasing atmospheric pCO2 levels via burial of Azolla-derived organic matter. The consequences of these enormous Azolla blooms for regional and global nutrient and carbon cycles are still largely unknown. Cultivation experiments have been set up to investigate the influence of elevated pCO2 on Azolla growth, showing a marked increase in Azolla productivity under elevated (760 and 1910 ppm) pCO2 conditions. The combined results of organic carbon, sulphur, nitrogen content and 15N and 13C measurements of sediments from the Azolla interval illustrate the potential contribution of nitrogen fixation in a euxinic stratified Eocene Arctic. Flux calculations were used to quantitatively reconstruct the potential storage of carbon (0.9-3.5 10(18) gC) in the Arctic during the Azolla interval. It is estimated that storing 0.9 10(18) to 3.5 10(18) g carbon would result in a 55 to 470 ppm drawdown of pCO2 under Eocene conditions, indicating that the Arctic Azolla blooms may have had a significant effect on global atmospheric pCO2 levels through enhanced burial of organic matter. PMID:19323694

Speelman, E N; Van Kempen, M M L; Barke, J; Brinkhuis, H; Reichart, G J; Smolders, A J P; Roelofs, J G M; Sangiorgi, F; de Leeuw, J W; Lotter, A F; Sinninghe Damsté, J S

2009-03-01

373

The environmental conditionings of the location of primeval settlements in the Wieprz River valley  

NASA Astrophysics Data System (ADS)

The Wieprz River along the section currently occupied by the Nadwieprza?ski Landscape Park (NLP) constituted a convenient place of human settlement from the moment of retreat of the last ice sheet. Depending on the types of economy preferred by representatives of individual archaeological cultures, the river valley from Spiczyn to Dorohucza offered continuous access to water. This obviously gained additional importance from the moment of appearance of Neolithic cultures, particularly the Globular Amphora culture and Corded Ware culture with semi-nomadic style of life, dealing with breeding. Neolithic hunters-gatherers exploited the animal resources available in the river and its vicinity. The further role of fishing, i.e. providing a diet element or supplementation already in the conditions of agricultural-breeding economy, seems to be evidenced by findings of fishing hooks at Lusatian and Wielbark sites. Another factor affecting the location of settlements in NLP was also its close vicinity to the crops of the Rejowiec flint. According to archaeologists, this is particularly obvious in the case of the Late Palaeolithic and the turn of the Neolithic and Bronze Age. The communication function of the river could also be of importance: in the case of seasonal animal migrations of animals and hunters (Late Palaeolithic); livestock and shepherds (Globular Amphora culture and Corded Ware culture); or people alone (migration of the population of the Wielbark culture to the Red Sea). The fact that a commercial trail fragment was located along the Wieprz River is probably evidenced by the abundance of import from various parts of Europe at site 53 in Spiczyn. Fertile soils (black soils, silt-peat soils) prevailing in the valley also favoured the settlement of cultures with an agricultural-breeding model of economy, providing good conditions for horticulture. Meadows near the river could be used as pastures.

Kozie?, Marcin; Kozie?, Wojciech

2012-01-01

374

Fish otolith geochemistry, environmental conditions and human occupation at Lake Mungo, Australia  

NASA Astrophysics Data System (ADS)

Fish otoliths from the Willandra Lakes Region World Heritage Area (south-western New South Wales, Australia) have been analysed for oxygen isotopes and trace elements using in situ techniques, and dated by radiocarbon. The study focused on the lunettes of Lake Mungo, an overflow lake that only filled during flooding events and emptied by evaporation, and Lake Mulurulu, which was part of the running Willandra Creek system. Samples were collected from two different contexts: from hearths directly associated with human activity, and isolated surface finds. AMS radiocarbon dating constrains the human activity documented by five different hearths to a time span of less than 240 years around 19,350 cal. BP. These hearths were constructed in aeolian sediments with alternating clay and sand layers, indicative of fluctuating lake levels and occasional drying out. The geochemistry of the otoliths confirms this scenario, with shifts in Sr/Ca and Ba/Ca marking the entry of the fish into Lake Mungo several years before their death, and a subsequent increase in the ?18O by ˜4‰ indicating increasing evaporation of the lake. During sustained lake-full conditions there are considerably fewer traces of human presence. It seems that the evaporating Lake Mungo attracted people to harvest fish that might have become sluggish through oxygen starvation in an increasingly saline water body (easy prey hypothesis). In contrast, surface finds have a much wider range in radiocarbon age as a result of reworking, and do not necessarily indicate evaporative conditions, as shown by comparison with otoliths from upstream Lake Mulurulu.

Long, Kelsie; Stern, Nicola; Williams, Ian S.; Kinsley, Les; Wood, Rachel; Sporcic, Katarina; Smith, Tegan; Fallon, Stewart; Kokkonen, Harri; Moffat, Ian; Grün, Rainer

2014-03-01

375

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

376

The influence of population dynamics and environmental conditions on salmon re-colonization after large-scale distrubance  

NASA Astrophysics Data System (ADS)

The transition from dispersal into unoccupied habitat to the establishment of a self-sustaining new population depends on the dynamics of the source and recipient populations, and the environmental conditions that facilitate or hinder exchange and successful reproduction. We used population growth rate, inter-annual variability estimates, habitat condition and size, hydrologic data, and an estimated dispersal effect to determine when colonizing pink salmon (Oncorhynchus gorbuscha) populations became self-sustaining after a long-term migration blockage (Hell’s Gate) was mitigated in the Fraser River, British Columbia, Canada. We used pink salmon spawning data from 1947 to 1987 in 66 streams to define populations, population growth rates, and the level of dispersal to newly accessible habitats. We also quantified the distance from source populations, the amount of newly accessible habitat, and determined whether stream flow conditions impeded fish passage at Hell’s Gate. Population dynamics models fit to observed data indicated that the combination of an initially large source population in the Fraser River below Hell’s Gate, high intrinsic growth rates linked to favorable climate-driven conditions, a constant supply of dispersers, and large amounts of newly available habitat resulted in the development of self-sustaining pink salmon populations in the Fraser River upstream of the historic barrier. Self-sustaining populations were developed within years of barrier removal and have continued to help expand the overall population of Fraser River pink salmon. However, not all locations had the same productivity and the magnitude of exchange among them was partly mediated by river conditions that permit or impede passage. Both re-colonized abundance levels were reduced and population spatial structure shifted relative to historic population abundance and spatial structure estimates.

Pess, G. R.; Hilborn, R.; Kloehn, K.; Quinn, T.

2010-12-01

377

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

378

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

379

Marine cold seeps and their manifestations: geological control, biogeochemical criteria and environmental conditions  

NASA Astrophysics Data System (ADS)

Characteristics of cold seeps at different geologic settings are the subject of this review primarily based on results of the Research Consortium SFB 574. Criteria are drawn from examples on the erosive convergent margin off Costa Rica, the accretionary margin off Chile supplemented by examples from the transform margin of the Golf of Cadiz and the convergent Hikurangi margin off New Zealand. Others are from well-studied passive margins of the Black Sea, the Golf of Mexico, the eastern Mediterranean Sea and the South China Sea. Seeps at all settings transport water and dissolved compounds to the ocean through the seafloor by different forcing mechanism and from different depths of the submerged geosphere (10s of meters to 10s of km). The compounds sustain oasis-type ecosystems by providing bioactive reductants sulfide, methane and hydrogen. Hereby, the interaction between fluid composition, flux rates and biota results in a diagnostic hydrocarbon-metazoan-microbe-carbonate association; currently, well over 100 active sites are known. The single most important reaction is microbially mediated anaerobic oxidation of methane with secondary reactions involving S-biogeochemistry and carbonate mineral precipitation. Seep fluids and their seafloor manifestations provide clues as to source depth, fluid-sediment/rock interaction during ascent, lifetime and cyclicity of seepage events but less so on the magnitude of return flow. At erosive margins, Cl-depleted and B-enriched fluids from clay dehydration provide criteria for source depth and temperature. The upward material flow generates mud volcanoes at the seafloor above the projected location of dehydration at depth. At accretionary margins, fluids are derived from more shallow depths by compaction of sediments as they ride on the incoming oceanic plate; they are emitted through thrust faults. At highly sedimented margins, organic-rich and evaporite-containing strata (when present) determine the final fluid composition, by emitting characteristically gas hydrate-derived methane, brine-associated non-methane hydrocarbons or leached elements and their isotopes (Li, ?7Li, B, Ba) from host sediments. Smectite-illite transformation and associated Cl-depletion from release of interlayer water is a pervasive process at these margins. Rare earth element pattern in conjunction with redox-sensitive metals retained in seep carbonates indicate whether or not they precipitated in contact with oxic bottom water or suboxic fluids; clear environmental characterization, though, currently remains inconclusive. More deeply sourced fluids as in transform margins may be characterized by their 87Sr/86Sr ratios from interaction with oceanic crustal rocks below. Quantification of flow and reliable estimates of total volatile output from fore-arcs remain a challenge to seep research, as does understanding the role of geologically derived methane in the global methane cycle.

Suess, Erwin

2014-10-01

380

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

381

Evaluation of conductive cooling of lactating dairy cows under controlled environmental conditions.  

PubMed

Cooling systems used to reduce heat stress in dairy operations require high energy, water usage, or both. Steady increases in electricity costs and reduction of water availability and an increase in water usage regulations require evaluation of passive cooling systems to cool cows and reduce use of water and electricity. A study was conducted to evaluate the use of heat exchangers buried 25cm below the surface as components in a conductive system for cooling cows. Six cows were housed in environmentally controlled rooms with tie-stall beds, which were equipped with a heat exchanger and filled with 25cm of either sand or dried manure. Beds were connected to supply and return lines and individually controlled. Two beds (one per each kind of bedding material) constituted a control group (water off), and the other 4 (2 sand and 2 dried manure) used water at 7°C passing through the heat exchangers (water on). The experiment was divided in 2 periods of 40d, and each period involved 3 repetitions of 3 different climates (hot and dry, thermo neutral, and hot and humid). Each cow was randomly assigned to a different treatment after each repetition was over. Sand bedding remained cooler than dried manure bedding in all environments and at all levels of cooling (water on or off). Bed temperatures were lower and heat flux higher during the bed treatment with sand and water on. We also detected a reduction in core body temperatures, respiration rates, rectal temperatures, and skin temperatures of those cows during the sand and water on treatment. Feed intake and milk yield numerically increased during the bed treatment with sand and water on for all climates. No major changes were observed in the lying time of cows or the composition of the milk produced. We conclude that use of heat exchangers is a viable adjunct to systems that employ fans, misters, and evaporative cooling methods to mitigate effects of heat stress on dairy cows. Sand was superior to dried manure as a bedding material in combination with heat exchangers. PMID:25547297

Ortiz, X A; Smith, J F; Rojano, F; Choi, C Y; Bruer, J; Steele, T; Schuring, N; Allen, J; Collier, R J

2015-03-01

382

Performance, egg quality, and immune response of laying hens fed diets supplemented with mannan-oligosaccharide or an essential oil mixture under moderate and hot environmental conditions.  

PubMed

In total, 432 thirty-six-week-old laying hens were fed a basal diet supplemented with mannan-oligosaccharide (MOS) or an essential oil mixture (EOM) from 36 to 51 wk of age. Hens were divided into 3 equal groups replicated 6 times with 24 hens per replicate. No significant difference was observed among the dietary treatments in terms of performance indices. Different from the dietary manipulation, high environmental temperatures negatively influenced all of the laying performance traits except the feed conversion ratio in association with the diminished feed consumption. The MOS, and particularly the EOM, tended to alleviate the deleterious effect of heat stress on BW gain. Mortality was higher in MOS-fed hens than with other treatments. A supplementation diet with MOS or EOM provided increments in eggshell weight (P < 0.01). Relative albumen weight was significantly decreased (P < 0.05) in response to EOM or MOS supplementation; however, this was not the case in the yolk weight rate. The MOS decreased albumen height and Haugh unit (P < 0.05). High environmental temperatures hampered entire egg quality characteristics except for the eggshell breaking strength and egg yolk weight. These results indicated that heat stress adversely affected both productive performance and egg quality. As for the results of this study, neither MOS nor EOM was efficacious in improving efficiency of egg production and stimulating humoral immune response in laying hens reared under moderate and hot climatic conditions. However, the ameliorative effect exerted by MOS and EOM on eggshell characteristics is conclusive. PMID:22582296

Bozkurt, M; Küçükyilmaz, K; Catli, A U; Cinar, M; Bintas, E; Cöven, F

2012-06-01

383

Efficacy of a store-based environmental change intervention compared with a delayed treatment control condition on store customers’ intake of fruits and vegetables  

PubMed Central

Objective The present store-based intervention was designed to promote sales of fruits and vegetables (F&V) to increase intake among store customers – specifically customers of tiendas, small-to-medium-sized Latino food stores. Design Four tiendas were randomized to a 2-month environmental change intervention or a delayed treatment control condition. Employees and managers were trained to promote F&V sales, including how to implement a food marketing campaign and installing store equipment to promote fresh fruits and vegetables. The primary outcome was self-reported daily intake of F&V among a convenience sample of customers (at least forty per store) collected at baseline prior to randomization and then 4 months later. In addition, changes in availability of F&V in the tiendas, using unobtrusive observational methods, provided evidence of intervention fidelity. Setting Tiendas in central North Carolina. Subjects Participants included 179 customers who were recent immigrants from Mexico and Central America. Results A group-by-time interaction approached significance on daily servings of F&V; intervention customers reported an increase in F&V intake over time and as a function of the intervention (P?0·06). Unexpectedly, self-efficacy for consuming more fruits (P?0·01) and more vegetables (P?0·06) decreased. In our store-level analyses, a group-by-time interaction was observed for availability of fresh and canned vegetables; the intervention increased availability of vegetables but not fruit. Conclusions Environmental change strategies to promote healthy eating are needed given the rates of obesity and diabetes in the Latino population. A store-based intervention was moderately effective at increasing customers’ reported F&V intake. Such strategies can have a public health impact on underserved populations. PMID:23561842

Ayala, Guadalupe X; Baquero, Barbara; Laraia, Barbara A; Ji, Ming; Linnan, Laura

2013-01-01

384

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

385

Unique picoeukaryotic algal community under multiple environmental stress conditions in a shallow, alkaline pan.  

PubMed

Winter phytoplankton communities in the shallow alkaline pans of Hungary are frequently dominated by picoeukaryotes, sometimes in particularly high abundance. In winter 2012, the ice-covered alkaline Zab-szék pan was found to be extraordinarily rich in picoeukaryotic green algae (42-82 × 10(6) cells ml(-1)) despite the simultaneous presence of multiple stressors (low temperature and light intensity with high pH and salinity). The maximum photosynthetic rate of the picoeukaryote community was 1.4 ?g C ?g chlorophyll a (-1) h(-1) at 125 ?mol m(-2) s(-1). The assimilation rates compared with the available light intensity measured on the field show that the community was considerably light-limited. Estimated areal primary production was 180 mg C m(-2) d(-1). On the basis of the 18S rRNA gene analysis (cloning and DGGE), the community was phylogenetically heterogeneous with several previously undescribed chlorophyte lineages, which indicates the ability of picoeukaryotic communities to maintain high genetic diversity under extreme conditions. PMID:24281914

Pálffy, Károly; Felföldi, Tamás; Mentes, Anikó; Horváth, Hajnalka; Márialigeti, Károly; Boros, Emil; Vörös, Lajos; Somogyi, Boglárka

2014-01-01

386

Fragmentation of amyloid fibrils occurs in preferential positions depending on the environmental conditions.  

PubMed

Understanding the mechanism of amyloid fibril breakage is of fundamental importance in various research fields including biomedicine and bionanotechnology. The aim of this work is to clarify the impact of temperature and agitation speed on the fibril breakage rate constant, which depends both on the fibril length as well as on the position of fragmentation along the fibril longitudinal axis. In particular, we intend to discriminate between three fibril fragmentation mechanisms: erosion (i.e., breakage occurs preferentially at the ends of the fibril), random (i.e., breakage occurs with the same likelihood at any position), or central (i.e., breakage occurs preferentially at the center of the fibril). To do so, we compare the time evolution of the fibril length distribution followed with atomic force microscopy with simulations from a kinetic model based on population balance equations (PBE). In this frame, we investigate the breakage mechanism of insulin fibrils, which turns out to be affected by the operative conditions employed. Moreover, we compare our findings with literature data obtained with ?-lactoglobulin and ?2-microglobulin. It is observed that high temperature drives the breakage toward an erosion mechanism, while a high agitation rate rather induces a central breakage. PMID:25792156

Nicoud, Lucrèce; Lazzari, Stefano; Balderas Barragán, Daniel; Morbidelli, Massimo

2015-04-01

387

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

388

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

389

In vitro development of Eucoleus böhmi eggs in different environmental conditions.  

PubMed

The development of Eucoleus böhmi eggs was evaluated in vitro in order to acquire information on the life cycle of this neglected respiratory nematode affecting canids. Fecal cultures were prepared using fecal samples from a positive dog and maintained at different conditions of temperature (20?±?1 and 5?±?1 °C) and relative humidity (RH) (85?±?5 and 45?±?5%). Egg development was microscopically examined at days +7, +15, and +30. In addition, in order to assess the vitality of eggs maintained at 5?±?1 °C for 30 days, these latter cultures were moved, placed at 20?±?1 °C and 85?±?5% RH, and observed for further 30 and 40 days. The results showed that at 20?±?1 °C and 85?±?5% RH, the totality of eggs completed development in 30 days, while about 26 and 70% of eggs were already fully developed after 7 and 15 days, respectively. No egg development occurred after 30 days at 5?±?1 °C, while 100% of eggs placed at 5?±?1 °C for 30 days and then moved at 20?±?1 °C and 85?±?5% RH for further 40 days were found fully developed. PMID:24777343

Perrucci, Stefania; Di Cesare, Angela; Fichi, Gianluca

2014-07-01

390

Comparative genome analysis reveals genetic adaptation to versatile environmental conditions and importance of biofilm lifestyle in Comamonas testosteroni.  

PubMed

Comamonas testosteroni is an important environmental bacterium capable of degrading a variety of toxic aromatic pollutants and has been demonstrated to be a promising biocatalyst for environmental decontamination. This organism is often found to be among the primary surface colonizers in various natural and engineered ecosystems, suggesting an extraordinary capability of this organism in environmental adaptation and biofilm formation. The goal of this study was to gain genetic insights into the adaption of C. testosteroni to versatile environments and the importance of a biofilm lifestyle. Specifically, a draft genome of C. testosteroni I2 was obtained. The draft genome is 5,778,710 bp in length and comprises 110 contigs. The average G+C content was 61.88 %. A total of 5365 genes with 5263 protein-coding genes were predicted, whereas 4324 (80.60 % of total genes) protein-encoding genes were associated with predicted functions. The catabolic genes responsible for biodegradation of steroid and other aromatic compounds on draft genome were identified. Plasmid pI2 was found to encode a complete pathway for aniline degradation and a partial catabolic pathway for chloroaniline. This organism was found to be equipped with a sophisticated signaling system which helps it find ideal niches and switch between planktonic and biofilm lifestyles. A large number of putative multi-drug-resistant genes coding for abundant outer membrane transporters, chaperones, and heat shock proteins for the protection of cellular function were identified in the genome of strain I2. In addition, the genome of strain I2 was predicted to encode several proteins involved in producing, secreting, and uptaking siderophores under iron-limiting conditions. The genome of strain I2 contains a number of genes responsible for the synthesis and secretion of exopolysaccharides, an extracellular component essential for biofilm formation. Overall, our results reveal the genomic features underlying the adaption of C. testosteroni to versatile environments and highlighting the importance of its biofilm lifestyle. PMID:25786738

Wu, Yichao; Arumugam, Krithika; Tay, Martin Qi Xiang; Seshan, Hari; Mohanty, Anee; Cao, Bin

2015-04-01

391

Setup for laboratory studies of the environmental conditions influence on the fixed charge state in silicon dioxide  

NASA Astrophysics Data System (ADS)

The position sensitive detectors operate in high intensity radiation field of the collider experiment [1]. Important task is to estimate the influence of different radiation effects on properties of the detector. We focus on the laboratory studies to estimate the reliability of different types of silicon detectors. We use the simple test structures produced by standard technology for the silicon detectors. We give the primary attention to the case when the depth of active detector region varies from 10 to 20 ? m because it leads to the most significant influence of SiO2-Si interface on processes in silicon bulk. We present the experimental results of long term irradiation test with Am241 (one year). Influence of the environmental conditions on the fixed charge states in silicon dioxide was investigated using developed simple model.

Kushpil, S.; Kushpil, V.; Mikhaylov, Vasily

2015-02-01

392

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

393

Establishing Baseline environmental Conditions for the Proposed Yucca Mountain Repository, Nevada, U.S.A.  

SciTech Connect

Research is underway to develop baseline site conditions and design monitoring programs for assurance to offsite residents and for performance confirmation for the proposed Yucca Mountain (YM) high-level waste repository in Nevada. This includes evaluation of existing and potential impacts on the proposed ''land withdrawal'' for the repository. A significant portion of the proposed land withdrawal includes areas now managed as part of the Nevada Test Site (NTS), and there is both contamination and land disturbance associated with past NTS activities. Establishing baseline conditions for the land withdrawal is important to distinguish potential impacts from repository operations from those resulting from previous activities, including some that took place from activities outside the land withdrawal. Among existing contamination is mixed fission products associated with the Nuclear Rocket Testing Program on the NTS in the 1960s. Some of these sites are being remediated as part of a federal facility agreement between the U.S. Department of Energy and the State of Nevada. However, even where radionuclides exist at levels below regulatory concern, characterizing them may be desirable if they are above background. In addition, Forty Mile Wash, the major drainage on the east side of YM, may be transporting radionuclides created from Plowshare project nuclear cratering experiments on Buckboard Mesa on the NTS. Although contaminant levels are not anticipated to present a risk, the point at which Forty Mile Wash leaves the proposed land withdrawal would be the closest point for an offsite receptor to YM. In addition, there is existing land disturbance (not necessarily associated with contamination) on both the NTS, as well as the portions of the proposed land withdrawal currently managed by the U.S. Bureau of Land Management and the U.S. Air Force. To establish a land disturbance baseline, high resolution multispectral satellite imagery collected in 2004 as well as hyperspectral imagery is being analyzed. Spectral and textural classification algorithms are being used to separate disturbed features such as paths, jeep trails, and building structures from background features. Disturbance features will be incorporated into a geographic information system. Follow-on activities will include examining areas of disturbance on the ground to characterize them and determine their origin. A longer term issue is the potential for radionuclide transport in groundwater from past areas of underground nuclear testing on the NTS (particularly Pahute Mesa) to areas where releases from YM could occur. To better address this, groundwater advective pathways are being traced from the proposed repository environment toward upgradient areas on the NTS. The Death Valley Regional Flow System model (issued in 2004 by the U.S. Geological Survey), which incorporates both YM and the NTS, is being used as the framework for the modeling. It is further enhanced with information from the YM Site Scale model and YM- and NTS-defined hydrogeologic units. Simulated pathways that intersect nuclear testing areas will identify regions on the NTS where potentially contaminated groundwater may originate and the routes for its potential migration toward YM.

D.S. Shafer; K.F. Pohlmann; C.E. Russell; D. Hovey-Spencer; M. Ye

2004-12-21

394

Investigations of sequential leaching behaviour of Cu and Zn from coal fly ash and their mobility in environmental conditions.  

PubMed

The quantitative evaluation of chemical fraction of Cu and Zn in the coal fly ash by methods of five-step sequential extraction was carried out in order to characterize metal mobility in environmental conditions. The research involved (i) water-soluble (pH 7), (ii) acid-soluble (pH 5), (iii) oxide, (iv) difficult reducible and (v) residual metal fractions. It was discovered, that the total extraction of the studied metals from coal fly ash to solutions take place in the following quantities Cu-39.0mgkg(-1) and Zn-89.0mgkg(-1). The investigations of chemical fractions proved that the subject metals occur mainly in coal fly ash as: oxide (Cu-12.0mgkg(-1), Zn-37.0mgkg(-1)) and residual (Cu-9.5mgkg(-1), Zn-27.0mgkg(-1)) as well as difficult reducible (Cu-16.5mgkg(-1), Zn-22.0mgkg(-1)). Low concentrations of metals for water-soluble fraction (Cuenvironmental conditions contain: 2.6% (Cu) and 3.4% (Zn) of metal total amount in the coal fly ash. The obtained mobility parameter of Cu and Zn can be applied to estimate the concentration increase of mobile and hardly mobile forms of these metals in soil polluted with the ash. PMID:17194534

Soco, Eleonora; Kalembkiewicz, Jan

2007-07-16

395

Herbal Supplement Extends Life Span Under Some Environmental Conditions and Boosts Stress Resistance  

PubMed Central

Genetic studies indicate that aging is modulated by a great number of genetic pathways. We have used Drosophila longevity and stress assays to test a multipath intervention strategy. To carry out this strategy, we supplemented the flies with herbal extracts (SC100) that are predicted to modulate the expression of many genes involved in aging and stress resistance, such as mTOR, NOS, NF-KappaB, and VEGF. When flies were housed in large cages with SC100 added, daily mortality rates of both male and female flies were greatly diminished in mid to late life. Surprisingly, SC100 also stabilized midlife mortality rate increases so as to extend the maximum life span substantially beyond the limits previously reported for D. melanogaster. Under these conditions, SC100 also promoted robust resistance to partial starvation stress and to heat stress. Fertility was the same initially in both treated and control flies, but it became significantly higher in treated flies at older ages as the fertility of control flies declined. Mean and maximum life spans of flies in vials at the same test site were also extended by SC100, but the life spans were short in absolute terms. In contrast, at an independent test site where stress was minimized, the flies exhibited much longer mean life spans, but the survival curves became highly rectangular and the effects of SC100 on both mean and maximum life spans declined greatly or were abolished. The data indicate that SC100 is a novel herbal mix with striking effects on enhancing Drosophila stress resistance and life span in some environments, while minimizing mid to late life mortality rates. They also show that the environment and other factors can have transformative effects on both the length and distribution of survivorship, and on the ability of SC100 to extend the life span. PMID:25879540

Villeponteau, Bryant; Matsagas, Kennedy; Nobles, Amber C.; Rizza, Cristina; Horwitz, Marc; Benford, Gregory; Mockett, Robin J.

2015-01-01

396

Arsenic removal by goethite and jarosite in acidic conditions and its environmental implications.  

PubMed

Schwertmannite (Fe(8)O(8)(OH)(5.5)(SO(4))(1.25)), jarosite (KFe(3)(SO(4))(2)(OH)(6)) and goethite (FeOOH) control natural attenuation of arsenic in acid mine drainage (AMD) impacted areas. Batch experiments were conducted to examine the sorption capacity of synthetic goethite and synthetic jarosite at highly acidic pH (1.5-2.5), at two ionic strengths (0.02-0.15 mol dm(-3), NaCl) and at sulphate concentrations in the range of 5 x 10(-3) to 2.8 x 10(-1) mol dm(-3). In the absence of competitive effects of other anions, K-jarosite presents better removal efficiency than goethite for As(V). The maximum sorption capacity is estimated to be 1.2 x 10(-4) and 7.0 x 10(-6)mol m(-2) for jarosite and goethite, respectively, under similar experimental conditions. The variation of arsenic sorbed on goethite as a function of the equilibrium arsenic concentration in solution fits a non-competitive Langmuir isotherm. In the case of K-jarosite, sorption data could not fit a Langmuir or Freundlich isotherm since sulphate-arsenate anion exchange is probably the sorption mechanism. Ionic strength and pH have little effect on the sorption capacity of goethite and jarosite in the small range of pH studied. The presence of sulphate, which is the main anion in AMD natural systems, has a negative effect on arsenic removal since sulphate competes with arsenate for surface sorption sites. Moreover, mobilization of arsenic in the transformation of schwertmannite to jarosite or goethite at pH 2-3 is proposed since the sorption capacities of goethite and K-jarosite are considerably lower than those reported for schwertmannite. PMID:19628332

Asta, María P; Cama, Jordi; Martínez, María; Giménez, Javier

2009-11-15

397

Effect of calibration and environmental condition on the performance of direct-reading organic vapor monitors.  

PubMed

The performance of three MIRAN SapphIRe Portable Infrared Ambient Air Analyzers and three Century Portable Toxic Vapor Analyzers equipped with photoionization (PID) and flame ionization (FID) detectors was compared with charcoal tube sampling. Relationships were investigated using two different calibration methods at four cyclohexane concentrations, three temperatures, and four relative humidities. For the first method, the TVA monitors were calibrated with a single concentration of methane for the FID, and isobutylene for the PID. The SapphIRe monitors were zeroed and the monitor's manufacturer-supplied library was used. For the second method, a five-point cyclohexane calibration curve was created for each monitor. Comparison of the monitor results of each calibration method (pooled data) indicated a significant difference between methods (t-test, p < 0.001), The SapphIRe group had results closer to the charcoal tubes with the second calibration method, while the PID and FID monitor groups performed better using the first calibration method. The PID monitor group's performance was affected only at the 90% relative humidity (RH) condition. Using the first method, the monitor readings were compared with the charcoal tube average using mixed linear model analyses of variance (ANOVAs) and regression. The ANOVA results showed there was a statistically significant difference among readings from all monitor types (p <0.0001). The regression results demonstrated that the SapphIRe (r² = 0.97) and FID (r² = 0.92) monitor groups correlated well with the charcoal tubes. The PID monitor group had a similar correlation when 90% RH was excluded (r² = 0.94) but had a weaker correlation when it was included (r² = 0.58). The operator should take care when using these monitors at high concentrations and the PID monitors at high humidities, consider the variability between units of the same monitor, and conduct performance verification of the monitor being used. PMID:23016630

Coffey, Christopher; LeBouf, Ryan; Lee, Larry; Slaven, James; Martin, Stephen

2012-01-01

398

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

SciTech Connect

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

El-Sayed, A.A.H.; Shebl, A.M.; Ramadan, M.A. [King Saud Univ., Riyadh (Saudi Arabia)

1995-11-01

399

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

400

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 juven