Science.gov

Sample records for environmental growth conditions

  1. Modelling mould growth under suboptimal environmental conditions and inoculum size.

    PubMed

    Garcia, Daiana; Ramos, Antonio J; Sanchis, Vicente; Marín, Sonia

    2010-10-01

    Predictive models can be a tool to develop strategies to prevent mould development and consequently mycotoxin production. The aims of this work were to assess the impact of a) high/low levels of inoculum and b) optimal/suboptimal environmental conditions on fungal responses based on both kinetic and probabilistic models. Different levels of spore suspensions of Aspergillus carbonarius and Penicillium expansum were prepared and inoculated centrally with a needlepoint load on malt extract agar (MEA) with 50 replicates. While optimum conditions led to a colony diameter increase which followed Baranyi's function, suboptimal conditions led to different grow functions. In general, growth rate (mu) and lag phase (lambda) were normally distributed. Specifically, the growth rate (mu) showed similar distributions under optimal growth conditions, regardless of the inoculum level, while suboptimal a(w) and temperature conditions led to higher kurtosis distributions, mainly when the inoculum levels were low. Regarding lambda, more skewed distributions were observed, mainly when the inoculum levels were low. Probability models were not much affected by the inoculum size. Lower probabilities of growth were in general predicted under marginal conditions at a given time for both strains. The slopes of the probability curves were smaller under suboptimal growth conditions due to wider distributions. Results showed that a low inoculum level and suboptimal conditions lead to high variability of the estimated growth parameters and growth probability.

  2. Strigolactones as mediators of plant growth responses to environmental conditions.

    PubMed

    Koltai, Hinanit; Kapulnik, Yoram

    2011-01-01

    Strigolactones (SLs) have been recently identified as a new group of plant hormones or their derivatives thereof, shown to play a role in plant development. Evolutionary forces have driven the development of mechanisms in plants that allow adaptive adjustments to a variety of different habitats by employing plasticity in shoot and root growth and development. The ability of SLs to regulate both shoot and root development suggests a role in the plant's response to its growth environment. To play this role, SL pathways need to be responsive to plant growth conditions, and affect plant growth toward increased adaptive adjustment. Here, the effects of SLs on shoot and root development are presented, and possible feedback loops between SLs and two environmental cues, light and nutrient status, are discussed; these might suggest a role for SLs in plants' adaptive adjustment to growth conditions.

  3. Strigolactones as mediators of plant growth responses to environmental conditions

    PubMed Central

    Kapulnik, Yoram

    2011-01-01

    Strigolactones (SLs) have been recently identified as a new group of plant hormones or their derivatives thereof, shown to play a role in plant development. Evolutionary forces have driven the development of mechanisms in plants that allow adaptive adjustments to a variety of different habitats by employing plasticity in shoot and root growth and development. The ability of SLs to regulate both shoot and root development suggests a role in the plant's response to its growth environment. To play this role, SL pathways need to be responsive to plant growth conditions, and affect plant growth toward increased adaptive adjustment. Here, the effects of SLs on shoot and root development are presented, and possible feedback loops between SLs and two environmental cues, light and nutrient status, are discussed; these might suggest a role for SLs in plants' adaptive adjustment to growth conditions. PMID:21248472

  4. Development of a predictive program for Vibrio parahaemolyticus growth under various environmental conditions.

    PubMed

    Fujikawa, Hiroshi; Kimura, Bon; Fujii, Tateo

    2009-09-01

    In this study, we developed a predictive program for Vibrio parahaemolyticus growth under various environmental conditions. Raw growth data was obtained with a V. parahaemolyticus O3:K6 strain cultured at a variety of broth temperatures, pH, and salt concentrations. Data were analyzed with our logistic model and the parameter values of the model were analyzed with polynomial equations. A prediction program consisting of the growth model and the polynomial equations was then developed. After the range of the growth environments was modified, the program successfully predicted the growth for all environments tested. The program could be a useful tool to ensure the bacteriological safety of seafood.

  5. Incorporating temporal heterogeneity in environmental conditions into a somatic growth model

    USGS Publications Warehouse

    Dzul, Maria C.; Yackulic, Charles B.; Korman, Josh; Yard, Michael D.; Muehlbauer, Jeffrey D.

    2017-01-01

    Evaluating environmental effects on fish growth can be challenging because environmental conditions may vary at relatively fine temporal scales compared to sampling occasions. Here we develop a Bayesian state-space growth model to evaluate effects of monthly environmental data on growth of fish that are observed less frequently (e.g., from mark-recapture data where time between captures can range from months to years). We assess effects of temperature, turbidity duration, food availability, flow variability, and trout abundance on subadult humpback chub (Gila cypha) growth in two rivers, the Colorado River (CR) and the Little Colorado River (LCR), and we use out-of-sample prediction to rank competing models. Environmental covariates explained a high proportion of the variation in growth in both rivers; however, the best growth models were river-specific and included either positive temperature and turbidity duration effects (CR) or positive temperature and food availability effects (LCR). Our approach to analyzing environmental controls on growth should be applicable in other systems where environmental data vary over relatively short time scales compared to animal observations.

  6. Extent of fungal growth on fiberglass duct liners with and without biocides under challenging environmental conditions.

    PubMed

    Samimi, Behzad S; Ross, Kristen

    2003-03-01

    Eight brands of fiberglass duct liners, including three that contained biocides, were exposed to challenging environmental conditions that would promote fungal growth. Twenty-four rectangular sheet metal ducts in three groups of eight ducts per group were lined with the eight selected liners. Each group of ducts was exposed to one of the three test conditions within an environmental chamber for a period of 15 days. These conditions were a) 75 percent RH, b) 75 percent RH plus water spray, c) 75 percent RH plus dry nutrient, and d) 75 percent RH plus water plus nutrient. Viable spores of Aspergillus niger were aerosolized into each duct as seed. On the 16th day, air and surface samples for fungal spores were collected from inside ducts. The results of air sampling using N6 sampler and visual inspection indicated that two out of three biocide-containing liners, Permacote and Toughgard, inhibited fungal growth but only under condition A. The third biocide-containing liner, Aeroflex Plus, was effective even when it was wet (conditions A and B). All three biocide-containing liners failed to inhibit fungal growth under conditions C and D. Among the five other types of liners that did not contain biocides, ATCO Flex with a smooth Mylar coating was more preferable, exhibiting lower fungal activity during conditions A, B, and C. All liners failed under condition D when nutrient and water were added together. Surface sampling using adhesive tape failed to produce representative results, apparently due to rough/porous surface of duct liners. It was concluded that duct liners with biocide treatment could be less promoting to microbial growth under high humidity as long as their surfaces remain clean and water-free. A liner with an impermeable and smooth surface seems to be less subject to microbial growth under most conditions than biocide-containing liners having porous and/or rough surfaces.

  7. The growth response of plants to elevated CO2 under non-optimal environmental conditions.

    PubMed

    Poorter, Hendrik; Pérez-Soba, Marta

    2001-09-01

    Under benign environmental conditions, plant growth is generally stimulated by elevated atmospheric CO2 concentrations. When environmental conditions become sub- or supra-optimal for growth, changes in the biomass enhancement ratio (BER; total plant biomass at elevated CO2 divided by plant biomass at the current CO2 level) may occur. We analysed literature sources that studied CO2×environment interactions on the growth of herbaceous species and tree seedlings during the vegetative phase. For each experiment we calculated the difference in BER for plants that were grown under 'optimal' and 'non-optimal' conditions. Assuming that interactions would be most apparent if the environmental stress strongly diminished growth, we scaled the difference in the BER values by the growth reduction due to the stress factor. In our compilation we found a large variability in CO2×environment interactions between experiments. To test the impact of experimental design, we simulated a range of analyses with a plant-to-plant variation in size common in experimental plant populations, in combination with a number of replicates generally used in CO2×environment studies. A similar variation in results was found as in the compilation of real experiments, showing the strong impact of stochasticity. We therefore caution against strong inferences derived from single experiments and suggest rather a reliance on average interactions across a range of experiments. Averaged over the literature data available, low soil nutrient supply or sub-optimal temperatures were found to reduce the proportional growth stimulation of elevated CO2. In contrast, BER increased when plants were grown at low water supply, albeit relatively modestly. Reduced irradiance or high salinity caused BER to increase in some cases and decrease in others, resulting in an average interaction with elevated CO2 that was not significant. Under high ozone concentrations, the relative growth enhancement by elevated CO2 was

  8. Growth characteristics of Saccharomyces cerevisiae S288C in changing environmental conditions: auxo-accelerostat study.

    PubMed

    Kasemets, Kaja; Nisamedtinov, Ildar; Laht, Tiiu-Maie; Abner, Kristo; Paalme, Toomas

    2007-07-01

    The effect of individual environmental conditions (pH, pO(2), temperature, salinity, concentration of ethanol, propanol, tryptone and yeast extract) on the specific growth rate as well as ethanol and glycerol production rate of Saccharomyces cerevisiae S288C was mapped during the fermentative growth in aerobic auxo-accelerostat cultures. The obtained steady-state values of the glycerol to ethanol formation ratio (0.1 mol mol(-1)) corresponding to those predicted from the stoichiometric model of fermentative yeast growth showed that the complete repression of respiration was obtained in auxostat culture and that the model is suitable for calculation of Y(ATP) and Q(ATP) values for the aerobic fermentative growth. Smooth decrease in the culture pH and dissolved oxygen concentration (pO2) down to the critical values of 2.3 and 0.8%, respectively, resulted in decrease in growth yield (Y(ATP)) and specific growth rate, however the specific ATP production rate (Q(ATP)) stayed almost constant. Increase in the concentration of biomass (>0.8 g dwt l(-1)), propanol (>2 g l(-1)) or NaCl (>15 g l(-1)) lead at first to the decrease in the specific growth rate and Q(ATP), while Y(ATP) was affected only at higher concentrations. The observed decrease in Q(ATP) was caused by indirect rather than direct inhibition of glycolysis. The increase in tryptone concentration resulted in an increase in the specific growth rate from 0.44 to 0.62 h(-1) and Y(ATP) from 12.5 to 18.5 mol ATP g dwt(-1). This study demonstrates that the auxo-accelerostat method, besides being an efficient tool for obtaining the culture characteristics, provides also decent conditions for the experiments elucidating the control mechanisms of cell growth.

  9. The exploring root--root growth responses to local environmental conditions.

    PubMed

    Monshausen, Gabriele B; Gilroy, Simon

    2009-12-01

    Because of their sessile lifestyle, the areas which plants can access to forage for resources are confined to those which can be explored by growth. High sensitivity to environmental conditions coupled to the appropriate readjustment of growth and developmental responses are thus critical to plant survival. In this review, we focus on how roots perceive physical cues such as soil water status and mechanical properties and translate them into physiological signals to redirect organ growth and modulate root system architecture. Because the precise molecular identity of most of the sensors used by the root to sample the soil environment remain to be determined, the mechanisms underlying similar processes in microbes are providing important models for how these receptor systems may be functioning in plants.

  10. Environmental Growth Conditions of Trichoderma spp. Affects Indole Acetic Acid Derivatives, Volatile Organic Compounds, and Plant Growth Promotion.

    PubMed

    Nieto-Jacobo, Maria F; Steyaert, Johanna M; Salazar-Badillo, Fatima B; Nguyen, Dianne Vi; Rostás, Michael; Braithwaite, Mark; De Souza, Jorge T; Jimenez-Bremont, Juan F; Ohkura, Mana; Stewart, Alison; Mendoza-Mendoza, Artemio

    2017-01-01

    Trichoderma species are soil-borne filamentous fungi widely utilized for their many plant health benefits, such as conferring improved growth, disease resistance and abiotic stress tolerance to their hosts. Many Trichoderma species are able to produce the auxin phytohormone indole-3-acetic acid (IAA), and its production has been suggested to promote root growth. Here we show that the production of IAA is strain dependent and diverse external stimuli are associated with its production. In in vitro assays, Arabidopsis primary root length was negatively affected by the interaction with some Trichoderma strains. In soil experiments, a continuum effect on plant growth was shown and this was also strain dependent. In plate assays, some strains of Trichoderma spp. inhibited the expression of the auxin reporter gene DR5 in Arabidopsis primary roots but not secondary roots. When Trichoderma spp. and A. thaliana were physically separated, enhancement of both shoot and root biomass, increased root production and chlorophyll content were observed, which strongly suggested that volatile production by the fungus influenced the parameters analyzed. Trichoderma strains T. virens Gv29.8, T. atroviride IMI206040, T. sp. "atroviride B" LU132, and T. asperellum LU1370 were demonstrated to promote plant growth through volatile production. However, contrasting differences were observed with LU1370 which had a negative effect on plant growth in soil but a positive effect in plate assays. Altogether our results suggest that the mechanisms and molecules involved in plant growth promotion by Trichoderma spp. are multivariable and are affected by the environmental conditions.

  11. Is ragweed pollen allergenicity governed by environmental conditions during plant growth and flowering?

    PubMed Central

    Ghiani, Alessandra; Ciappetta, Silvia; Gentili, Rodolfo; Asero, Riccardo; Citterio, Sandra

    2016-01-01

    Pollen allergenicity is one of the main factors influencing the prevalence and/or severity of allergic diseases. However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work 180 ragweed plants from three Regions (Canada, France, Italy) were grown in both controlled (constant) and standard environmental conditions (seasonal changes in temperature, relative humidity and light). Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1. Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants. This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms. It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content. PMID:27457754

  12. Is ragweed pollen allergenicity governed by environmental conditions during plant growth and flowering?

    NASA Astrophysics Data System (ADS)

    Ghiani, Alessandra; Ciappetta, Silvia; Gentili, Rodolfo; Asero, Riccardo; Citterio, Sandra

    2016-07-01

    Pollen allergenicity is one of the main factors influencing the prevalence and/or severity of allergic diseases. However, how genotype and environment contribute to ragweed pollen allergenicity has still to be established. To throw some light on the factors governing allergenicity, in this work 180 ragweed plants from three Regions (Canada, France, Italy) were grown in both controlled (constant) and standard environmental conditions (seasonal changes in temperature, relative humidity and light). Pollen from single plants was characterized for its allergenic potency and for the underlying regulation mechanisms by studying the qualitative and quantitative variations of the main isoforms of the major ragweed allergen Amb a 1. Results showed a statistically higher variability in allergenicity of pollen from standard conditions than from controlled conditions growing plants. This variability was due to differences among single plants, regardless of their origin, and was not ascribed to differences in the expression and IgE reactivity of individual Amb a 1 isoforms but rather to quantitative differences involving all the studied isoforms. It suggests that the allergenic potency of ragweed pollen and thus the severity of ragweed pollinosis mainly depends on environmental conditions during plant growth and flowering, which regulate the total Amb a 1 content.

  13. Biocontrol agents promote growth of potato pathogens, depending on environmental conditions.

    PubMed

    Cray, Jonathan A; Connor, Mairéad C; Stevenson, Andrew; Houghton, Jonathan D R; Rangel, Drauzio E N; Cooke, Louise R; Hallsworth, John E

    2016-05-01

    There is a pressing need to understand and optimize biological control so as to avoid over-reliance on the synthetic chemical pesticides that can damage environmental and human health. This study focused on interactions between a novel biocontrol-strain, Bacillus sp. JC12GB43, and potato-pathogenic Phytophthora and Fusarium species. In assays carried out in vitro and on the potato tuber, the bacterium was capable of near-complete inhibition of pathogens. This Bacillus was sufficiently xerotolerant (water activity limit for growth = 0.928) to out-perform Phytophthora infestans (~0.960) and challenge Fusarium coeruleum (~0.847) and Fusarium sambucinum (~0.860) towards the lower limits of their growth windows. Under some conditions, however, strain JC12GB43 stimulated proliferation of the pathogens: for instance, Fusarium coeruleum growth-rate was increased under chaotropic conditions in vitro (132 mM urea) by >100% and on tubers (2-M glycerol) by up to 570%. Culture-based assays involving macromolecule-stabilizing (kosmotropic) compatible solutes provided proof-of-principle that the Bacillus may provide kosmotropic metabolites to the plant pathogen under conditions that destabilize macromolecular systems of the fungal cell. Whilst unprecedented, this finding is consistent with earlier reports that fungi can utilize metabolites derived from bacterial cells. Unless the antimicrobial activities of candidate biocontrol strains are assayed over a full range of field-relevant parameters, biocontrol agents may promote plant pathogen infections and thereby reduce crop yields. These findings indicate that biocontrol activity, therefore, ought to be regarded as a mode-of-behaviour (dependent on prevailing conditions) rather than an inherent property of a bacterial strain. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  14. Environmental Growth Conditions of Trichoderma spp. Affects Indole Acetic Acid Derivatives, Volatile Organic Compounds, and Plant Growth Promotion

    PubMed Central

    Nieto-Jacobo, Maria F.; Steyaert, Johanna M.; Salazar-Badillo, Fatima B.; Nguyen, Dianne Vi; Rostás, Michael; Braithwaite, Mark; De Souza, Jorge T.; Jimenez-Bremont, Juan F.; Ohkura, Mana; Stewart, Alison

    2017-01-01

    Trichoderma species are soil-borne filamentous fungi widely utilized for their many plant health benefits, such as conferring improved growth, disease resistance and abiotic stress tolerance to their hosts. Many Trichoderma species are able to produce the auxin phytohormone indole-3-acetic acid (IAA), and its production has been suggested to promote root growth. Here we show that the production of IAA is strain dependent and diverse external stimuli are associated with its production. In in vitro assays, Arabidopsis primary root length was negatively affected by the interaction with some Trichoderma strains. In soil experiments, a continuum effect on plant growth was shown and this was also strain dependent. In plate assays, some strains of Trichoderma spp. inhibited the expression of the auxin reporter gene DR5 in Arabidopsis primary roots but not secondary roots. When Trichoderma spp. and A. thaliana were physically separated, enhancement of both shoot and root biomass, increased root production and chlorophyll content were observed, which strongly suggested that volatile production by the fungus influenced the parameters analyzed. Trichoderma strains T. virens Gv29.8, T. atroviride IMI206040, T. sp. “atroviride B” LU132, and T. asperellum LU1370 were demonstrated to promote plant growth through volatile production. However, contrasting differences were observed with LU1370 which had a negative effect on plant growth in soil but a positive effect in plate assays. Altogether our results suggest that the mechanisms and molecules involved in plant growth promotion by Trichoderma spp. are multivariable and are affected by the environmental conditions. PMID:28232840

  15. Impact of axial root growth angles on nitrogen acquisition in maize depends on environmental conditions

    PubMed Central

    Dathe, A.; Postma, J. A.; Postma-Blaauw, M. B.; Lynch, J. P.

    2016-01-01

    Backgrounds and Aims Crops with reduced requirement for nitrogen (N) fertilizer would have substantial benefits in developed nations, while improving food security in developing nations. This study employs the functional structural plant model SimRoot to test the hypothesis that variation in the growth angles of axial roots of maize (Zea mays L.) is an important determinant of N capture. Methods Six phenotypes contrasting in axial root growth angles were modelled for 42 d at seven soil nitrate levels from 10 to 250 kg ha−1 in a sand and a silt loam, and five precipitation regimes ranging from 0·5× to 1·5× of an ambient rainfall pattern. Model results were compared with soil N measurements of field sites with silt loam and loamy sand textures. Key Results For optimal nitrate uptake, root foraging must coincide with nitrate availability in the soil profile, which depends on soil type and precipitation regime. The benefit of specific root architectures for efficient N uptake increases with decreasing soil N content, while the effect of soil type increases with increasing soil N level. Extreme root architectures are beneficial under extreme environmental conditions. Extremely shallow root systems perform well under reduced precipitation, but perform poorly with ambient and greater precipitation. Dimorphic phenotypes with normal or shallow seminal and very steep nodal roots performed well in all scenarios, and consistently outperformed the steep phenotypes. Nitrate uptake increased under reduced leaching conditions in the silt loam and with low precipitation. Conclusions Results support the hypothesis that root growth angles are primary determinants of N acquisition in maize. With decreasing soil N status, optimal angles resulted in 15–50 % greater N acquisition over 42 d. Optimal root phenotypes for N capture varied with soil and precipitation regimes, suggesting that genetic selection for root phenotypes could be tailored to specific environments. PMID

  16. Impact of axial root growth angles on nitrogen acquisition in maize depends on environmental conditions.

    PubMed

    Dathe, A; Postma, J A; Postma-Blaauw, M B; Lynch, J P

    2016-09-01

    Crops with reduced requirement for nitrogen (N) fertilizer would have substantial benefits in developed nations, while improving food security in developing nations. This study employs the functional structural plant model SimRoot to test the hypothesis that variation in the growth angles of axial roots of maize (Zea mays L.) is an important determinant of N capture. Six phenotypes contrasting in axial root growth angles were modelled for 42 d at seven soil nitrate levels from 10 to 250 kg ha(-1) in a sand and a silt loam, and five precipitation regimes ranging from 0·5× to 1·5× of an ambient rainfall pattern. Model results were compared with soil N measurements of field sites with silt loam and loamy sand textures. For optimal nitrate uptake, root foraging must coincide with nitrate availability in the soil profile, which depends on soil type and precipitation regime. The benefit of specific root architectures for efficient N uptake increases with decreasing soil N content, while the effect of soil type increases with increasing soil N level. Extreme root architectures are beneficial under extreme environmental conditions. Extremely shallow root systems perform well under reduced precipitation, but perform poorly with ambient and greater precipitation. Dimorphic phenotypes with normal or shallow seminal and very steep nodal roots performed well in all scenarios, and consistently outperformed the steep phenotypes. Nitrate uptake increased under reduced leaching conditions in the silt loam and with low precipitation. Results support the hypothesis that root growth angles are primary determinants of N acquisition in maize. With decreasing soil N status, optimal angles resulted in 15-50 % greater N acquisition over 42 d. Optimal root phenotypes for N capture varied with soil and precipitation regimes, suggesting that genetic selection for root phenotypes could be tailored to specific environments. © The Author 2016. Published by Oxford University Press on

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

    PubMed Central

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

    2012-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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

    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

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

    PubMed Central

    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

    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

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

    NASA Astrophysics Data System (ADS)

    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

    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

  1. Effects of environmental conditions on growth and survival of Salmonella in pasteurized whole egg.

    PubMed

    Jakočiūnė, Džiuginta; Bisgaard, Magne; Hervé, Gaëlle; Protais, Jocelyne; Olsen, John Elmerdahl; Chemaly, Marianne

    2014-08-01

    This study investigated the influence of three parameters (time, temperature and NaCl concentration) on survival and four parameters (temperature, NaCl and lysozyme concentrations and pH) on growth of Salmonella enterica serovar Enteritidis (S. Enteritidis) in pasteurized whole egg (PWE). Doehlert uniform shell design was employed to choose conditions for trials and data was fitted to polynomial models and were presented as estimated response surfaces. A model for prediction of reduction of S. Enteritidis in PWE within temperatures between 50 and 58°C, NaCl concentrations of 0-12%, and heating times between 30 and 210s and a model for prediction of growth rate of S. Enteritidis in PWE in the temperature range of 1-25°C, NaCl concentration of 0-12%, pH between 5 and 9, and lysozyme concentrations of 107-1007 U/mg proteins were developed. The maximum reduction condition was 58°C, 0% of NaCl at a fixed heating time of 120s, while maximum growth rate was estimated at 25°C and 0% of NaCl. pH and lysozyme concentration were shown not to influence growth performance significantly in the range of values studied. Results inform industry of the optimal pasteurization and storage parameters for liquid whole egg. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Growth kinetics and energetics of a deep-sea hyperthermophilic methanogen under varying environmental conditions.

    PubMed

    Ver Eecke, Helene C; Akerman, Nancy H; Huber, Julie A; Butterfield, David A; Holden, James F

    2013-10-01

    A hyperthermophilic deep-sea methanogen, Methanocaldococcus strain JH146, was isolated from 26°C hydrothermal fluid at Axial Volcano to model high temperature methanogenesis in the subseafloor. Emphasis was placed on defining growth kinetics, cell yields and growth energy demand (GE) across a range of conditions. The organism uses H2 and CO2 as its sole carbon and energy sources. At various temperatures, pHs, and chlorinities, its growth rates and cell yields co-varied while GE remained uniform at 1.69 × 10(-11) J cell(-1)s(-1) ± 0.68 × 10(-11) J cell(-1)s(-1) (s.d., n = 23). An exception was at superoptimal growth temperatures where GE increased to 7.25 × 10(-11) J cell(-1)s(-1) presumably due to heat shock. GE also increased from 5.1 × 10(-12) J cell(-1)s(-1) to 7.61 × 10(-11) J cell(-1)s(-1) as NH4 (+) concentrations decreased from 9.4 mM to 0.14 mM. JH146 did not fix N2 or assimilate NO3 (-), lacked the N2-fixing (cluster II) nifH gene, and became nitrogen limited below 0.14 mM NH4Cl. Nitrogen availability may impact growth in situ since ammonia concentrations at Axial Volcano are < 18 μM. Our approach contributes to refining bioenergetic and carbon flux models for methanogens and other organisms in hydrothermal vents and other environments.

  3. Germination and Growth of a Vegetable Exposed to Very Severe Environmental Conditions Experimentally Induced by High Voltage

    NASA Astrophysics Data System (ADS)

    Aoki, Takashi; Ikezawa, Shunjiro

    1982-09-01

    Ultra-high-voltage (UHV) transmission power lines are required in order to reduce transmission energy losses, and to transfer more power across long distances. However, the ecological and biological influence of UHV lines has not been documented well. Possible influences of UHV lines are: electro-magnetic field, ozone, NOx, and ion shower. The purpose of this study was to obtain information on the germination and growth of Raphanus sativus L.cv. Kaiware-daikon exposed to an experimental environment in which all the above influences at very severe intensity levels were working simultaneously. Several environmental conditions severer than those predicted for future UHV lines were set up, using a high voltage at 60 Hz. The germination and growth of this plant were suppressed under the experimental conditions used, the suppression being greater the severer the conditions. When the electric field is strong, corona discharge occurs at the tip of the plant.

  4. Is intraspecific variability of growth and mycotoxin production dependent on environmental conditions? A study with Aspergillus carbonarius isolates.

    PubMed

    Garcia, Daiana; Ramos, Antonio J; Sanchis, Vicente; Marín, Sonia

    2011-01-05

    The aim of this study was to assess the impact of suboptimal environmental conditions on the intraspecific variability of A. carbonarius growth and OTA production using thirty isolates of A. carbonarius. Three a(w)/temperature conditions were tested, one optimal (0.98a(w)/25°C) and two suboptimal: 0.90a(w)/25°C and 0.98a(w)/37°C as suboptimal water activity and temperature, respectively, which might take place through over ripening and dehydration of grapes. For each condition, 12 Petri dishes were inoculated, and colony growth and OTA production were measured over time. ANOVA revealed significant differences among μ and λ within the 30 assayed isolates. Coefficients of variation (CV%) revealed a wider dispersion of growth rates at 0.90a(w)/25°C compared to 0.98a(w)/25°C, and a more than 4-fold higher CV at 0.98a(w)/37°C compared to 0.98a(w)/25°C. However, dispersion of lag phases was similar at 0.98a(w)/25°C and 0.90a(w)/25°C and wider at 0.98a(w)/37°C. There were significant differences (p<0.05) among OTA levels (ng/mm(2)) for the different conditions, values being lower under marginal conditions, and particularly at 0.98a(w)/37°C. Coefficients of variation (CV%) revealed a wider dispersion of OTA production at 0.90a(w)/25°C compared to 0.98a(w)/25°C, while CV at 0.98a(w)/37°C was similar to that at 0.98a(w)/25°C. In order to address the strain variability in growth initiation and prove the well-established notion of reducing OTA in foods by preventing fungal growth, a greater number of strains should be included when developing models for conditions that are suboptimal both for a(w) for OTA production and temperature levels for growth.

  5. Azerbaijan: environmental conditions and outlook.

    PubMed

    Shelton, Napier

    2003-06-01

    The author describes present environmental conditions in Azerbaijan in relation to the Soviet legacy and measures taken since independence. Environmental projects have been financed largely by international organizations and foreign companies. The most serious problems are contaminants in the Caspian Sea; air, water, and soil pollution in Sumgait; illegal fishing; poor quality of drinking water; cutting of forests for fuel and pasture; overgrazing; and soil erosion and salinization. Progress in developing an environmental conscience, necessary for sustained protection of the environment, will depend most importantly on environmental education, growth of democratic institutions and attitudes that encourage both governmental and citizen responsibility for the environment, and economic development that produces a substantial middle class. Positive advances include a Constitution and laws that require protection of the environment, and individuals who speak out for environmental care. Negative factors include poverty and the present government's low priority for environmental protection.

  6. Bacterial Epimerization as a Route for Deoxynivalenol Detoxification: the Influence of Growth and Environmental Conditions

    PubMed Central

    He, Jian Wei; Hassan, Yousef I.; Perilla, Norma; Li, Xiu-Zhen; Boland, Greg J.; Zhou, Ting

    2016-01-01

    Deoxynivalenol (DON) is a toxic secondary metabolite produced by several Fusarium species that infest wheat and corn. Food and feed contaminated with DON pose a health risk to both humans and livestock and form a major barrier for international trade. Microbial detoxification represents an alternative approach to the physical and chemical detoxification methods of DON-contaminated grains. The present study details the characterization of a novel bacterium, Devosia mutans 17-2-E-8, that is capable of transforming DON to a non-toxic stereoisomer, 3-epi-deoxynivalenol under aerobic conditions, mild temperature (25–30°C), and neutral pH. The biotransformation takes place in the presence of rich sources of organic nitrogen and carbon without the need of DON to be the sole carbon source. The process is enzymatic in nature and endures a high detoxification capacity (3 μg DON/h/108 cells). The above conditions collectively suggest the possibility of utilizing the isolated bacterium as a feed treatment to address DON contamination under empirical field conditions. PMID:27148248

  7. Bacterial Epimerization as a Route for Deoxynivalenol Detoxification: the Influence of Growth and Environmental Conditions.

    PubMed

    He, Jian Wei; Hassan, Yousef I; Perilla, Norma; Li, Xiu-Zhen; Boland, Greg J; Zhou, Ting

    2016-01-01

    Deoxynivalenol (DON) is a toxic secondary metabolite produced by several Fusarium species that infest wheat and corn. Food and feed contaminated with DON pose a health risk to both humans and livestock and form a major barrier for international trade. Microbial detoxification represents an alternative approach to the physical and chemical detoxification methods of DON-contaminated grains. The present study details the characterization of a novel bacterium, Devosia mutans 17-2-E-8, that is capable of transforming DON to a non-toxic stereoisomer, 3-epi-deoxynivalenol under aerobic conditions, mild temperature (25-30°C), and neutral pH. The biotransformation takes place in the presence of rich sources of organic nitrogen and carbon without the need of DON to be the sole carbon source. The process is enzymatic in nature and endures a high detoxification capacity (3 μg DON/h/10(8) cells). The above conditions collectively suggest the possibility of utilizing the isolated bacterium as a feed treatment to address DON contamination under empirical field conditions.

  8. Linking Metabolism, Elemental Cycles, and Environmental Conditions in the Deep Biosphere: Growth of a Model Extremophile, Archaeoglobus fulgidus, Under High-Pressure Conditions

    NASA Astrophysics Data System (ADS)

    Oliver, G. C. M.; Cario, A.; Rogers, K. L.

    2015-12-01

    A majority of Earth's biosphere is hosted in subsurface environments where global-scale biogeochemical and energy cycles are driven by diverse microbial communities that operate on and are influenced by micro-scale environmental variables. While the subsurface hosts a variety of geochemical and geothermal conditions, elevated pressures are common to all subsurface ecosystems. Understanding how microbes adapt to and thrive in high-pressure environments is essential to linking microbial subsurface processes with global-scale cycles. Here we are using a model extremophile, Archaeoglobus fulgidus, to determine how elevated pressures affect the growth, metabolism, and physiology of subsurface microorganisms. A. fulgidus cycles carbon and sulfur via heterotrophic and autotrophic sulfate reduction in various high temperature and high-pressure niches including shallow marine vents, deep-sea hydrothermal vents, and deep oil reservoirs. Here we report the results of A. fulgidus growth experiments at optimum temperature, 83°C, and pressures up to 600 bars. Exponential growth was observed over the entire pressure range, though growth rates were diminished at 500 and 600 bars compared to ambient pressure experimental controls. At pressures up to 400 bars, cell density yields and growth rates were at least as high as ambient pressure controls. Elevated pressures and extended incubation times stimulated cell flocculation, a common stress response in this strain, and cellular morphology was affected at pressures exceeding 400 bars. These results suggest that A. fulgidus continues carbon, sulfur and energy cycling unaffected by elevated pressures up to 400 bars, representing a variety of subsurface environments. The ability of subsurface organisms to drive biogeochemical cycles at elevated pressures is a critical link between the surface and subsurface biospheres and understanding how species-scale processes operate under these conditions is a vital part of global

  9. Growth and Environmental Quality

    ERIC Educational Resources Information Center

    Gordon, Larry J.

    1976-01-01

    The author suggests that numbers and distribution of people should be given highest priority in dealing with environmental quality. If population problems are solved, then other environmental problems will be prevented or solved. New Mexico, contends the author, must determine the balance between growth and quality of life. (MR)

  10. Uniformity of environmental conditions and plant growth in a hydroponic culture system for use in a growth room with aerial CO2 control

    NASA Technical Reports Server (NTRS)

    Vessey, J. K.; York, E. K.; Henry, L. T.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1988-01-01

    A portable system of hydroponic culture was developed that maintained temperature, pH, and nutrient concentrations of circulating nutrient solutions. The hydroponic system is used within a controlled-environment room (CER) for control of aerial environment. The CER was equipped with an auto-calibrating system for atmospheric CO2 control. The control systems for the hydroponic chambers were able to maintain acidity within +/- 0.2 pH units and the temperature with +/- 0.5 degree C. Mixing time for the 200-liter volume of solution within a hydroponic chamber was less than 12 min. The CO2 control system was able to maintain aerial concentrations within +/- 10 ppm CO2 during the light period. The only gradient found to occur within the hydroponic chambers or CER was a slight gradient in aerial temperature along the length of hydroponic chambers. Growth of soybeans [Glycine max (L.) Merr.] was characterized during a 3-week period of vegetative development by leaf number and area, plant dry weight, total N content of plants, and N depletion from the nutrient solution. The growth characteristics among populations for three hydroponic chambers within the CER were not significantly different, and the percent standard errors of means of the measurements within populations from each chamber were nearly all less than 10%. Thus, the uniformity of plant growth reflected the uniformity of environmental conditions.

  11. Uniformity of environmental conditions and plant growth in a hydroponic culture system for use in a growth room with aerial CO2 control.

    PubMed

    Vessey, J K; York, E K; Henry, L T; Raper, C D

    1988-01-01

    A portable system of hydroponic culture was developed that maintained temperature, pH, and nutrient concentrations of circulating nutrient solutions. The hydroponic system is used within a controlled-environment room (CER) for control of aerial environment. The CER was equipped with an auto-calibrating system for atmospheric CO2 control. The control systems for the hydroponic chambers were able to maintain acidity within +/- 0.2 pH units and the temperature with +/- 0.5 degree C. Mixing time for the 200-liter volume of solution within a hydroponic chamber was less than 12 min. The CO2 control system was able to maintain aerial concentrations within +/- 10 ppm CO2 during the light period. The only gradient found to occur within the hydroponic chambers or CER was a slight gradient in aerial temperature along the length of hydroponic chambers. Growth of soybeans [Glycine max (L.) Merr.] was characterized during a 3-week period of vegetative development by leaf number and area, plant dry weight, total N content of plants, and N depletion from the nutrient solution. The growth characteristics among populations for three hydroponic chambers within the CER were not significantly different, and the percent standard errors of means of the measurements within populations from each chamber were nearly all less than 10%. Thus, the uniformity of plant growth reflected the uniformity of environmental conditions.

  12. Uniformity of environmental conditions and plant growth in a hydroponic culture system for use in a growth room with aerial CO2 control

    NASA Technical Reports Server (NTRS)

    Vessey, J. K.; York, E. K.; Henry, L. T.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1988-01-01

    A portable system of hydroponic culture was developed that maintained temperature, pH, and nutrient concentrations of circulating nutrient solutions. The hydroponic system is used within a controlled-environment room (CER) for control of aerial environment. The CER was equipped with an auto-calibrating system for atmospheric CO2 control. The control systems for the hydroponic chambers were able to maintain acidity within +/- 0.2 pH units and the temperature with +/- 0.5 degree C. Mixing time for the 200-liter volume of solution within a hydroponic chamber was less than 12 min. The CO2 control system was able to maintain aerial concentrations within +/- 10 ppm CO2 during the light period. The only gradient found to occur within the hydroponic chambers or CER was a slight gradient in aerial temperature along the length of hydroponic chambers. Growth of soybeans [Glycine max (L.) Merr.] was characterized during a 3-week period of vegetative development by leaf number and area, plant dry weight, total N content of plants, and N depletion from the nutrient solution. The growth characteristics among populations for three hydroponic chambers within the CER were not significantly different, and the percent standard errors of means of the measurements within populations from each chamber were nearly all less than 10%. Thus, the uniformity of plant growth reflected the uniformity of environmental conditions.

  13. Near-bed environmental conditions influencing cold-water coral growth on Viosca Knoll, Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Mienis, F.; Duineveld, G.; Davies, A. J.; Weering, T. V.; Ross, S.; Roberts, M.; Seim, H.

    2010-12-01

    transported to the area. Sediment trap samples show a similar pattern and high mass fluxes are found, varying between 1.1-4.5 gm-2day-1. High mass fluxes and turbidity values can be related to an increased input of material coming from the Mississippi River. The environmental conditions on Viosca Knoll resemble those recorded in CWC areas on the European margin. Even though oxygen values are low and high mass fluxes were recorded, the CWC ecosystem thrives at present. The proximity of the area to the Mississippi River may benefit the corals by increasing the food supply. Migration of zooplankton and episodes of fresh particle supply from surface water form the mechanisms of food delivery, influencing CWC growth. Subsequently baffling of particles between the coral framework likely increases lateral extension and reef growth.

  14. Marked deleterious changes in the condition, growth and maturity schedules of Acanthopagrus butcheri (Sparidae) in an estuary reflect environmental degradation

    NASA Astrophysics Data System (ADS)

    Cottingham, Alan; Hesp, S. Alex; Hall, Norman G.; Hipsey, Matthew R.; Potter, Ian C.

    2014-08-01

    As Acanthopagrus butcheri typically completes its life within its natal estuary and possesses plastic biological characteristics, it provides an excellent model for exploring the ways and extent to which a fish species can respond to environmental changes over time. The environment of the Swan River Estuary in south-western Australia has deteriorated markedly during the last two decades, reflecting the effects of increasing eutrophication and hypoxia in the upper regions, where A. butcheri spends most of the year and spawns. In this study, the biological characteristics of A. butcheri in 2007-11 were determined and compared with those in 1993-95. Between these two periods, the condition factor for females and males of A. butcheri across their length ranges declined by 6 and 5%, respectively, and the parameters k and L∞ in the von Bertalanffy growth curves of both sexes underwent marked reductions. The predicted lengths of females and males at all ages ≥1 year were less in 2007-11 than in 1993-95 and by over 30% less at ages 3 and 6. The ogives relating maturity to length and age typically differed between 1993-94 and 2007-10. The L50s of 156 mm for females and 155 mm for males in 2007-10 were less than the corresponding values of 174 and 172 mm in 1993-94, whereas the A50s of 2.5 years for both females and males in 2007-10 were greater than the corresponding values of 1.9 and 2.0 years in 1993-94. The above trends in condition, growth and maturity parameters between periods are consistent with hypotheses regarding the effects of increasing hypoxia on A. butcheri in offshore, deeper waters. However, as the density of A. butcheri declined in offshore, deeper waters and increased markedly in nearshore, shallow waters, density-dependent effects in the latter waters, although better oxygenated, also probably contributed to the overall reductions in growth and thus to the changes in the lengths and ages at maturity.

  15. Instrumenting the Conifers: A Look at Daily Tree Growth and Locally Observed Environmental Conditions Across Four Mountain Sites in the Central Great Basin, USA

    NASA Astrophysics Data System (ADS)

    Strachan, S.; Biondi, F.; Johnson, B. G.

    2012-12-01

    Tree growth is often used as a proxy for past environmental conditions or as an indicator of developing trends. Reconstructions of drought, precipitation, temperature, and other phenomena derived from tree-growth indices abound in scientific literature aimed at informing policy makers. Observations of tree recruitment or death in treeline populations are frequently tied to climatic fluctuation in cause-effect hypotheses. Very often these hypotheses are based on statistical relationships between annual-to-seasonal tree growth measurements and some environmental parameter measured or modeled off-site. Observation of daily tree growth in conjunction with in-situ environmental measurements at similar timescales takes us one step closer to quantifying the uncertainty in reconstruction or predictive studies. In four separate sites in two different mountain ranges in the central Great Basin, co-located observations of conifer growth activity and local atmospheric and soils conditions have been initiated. Species include Pinus longaeva (Great Basin bristlecone pine), Pinus flexilis (limber pine), Picea engelmannii (Engelmann spruce), Pinus monophylla (singleleaf pinyon pine), Pinus ponderosa (ponderosa pine), Abies concolor (white fir), and Pseudotsuga menziesii (Douglas-fir). Measurements of sub-hourly tree radial length change and sap flow activity are compared with a suite of in-situ observations including air temperature, precipitation, photosynthetically-active radiation (PAR), relative humidity, soil temperature, and soil moisture/water content. Subalpine study site located at 3360 m elevation in the Snake Range, Nevada

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

    PubMed

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

    2014-04-01

    The effects of short-term (7 d) exposure to environmental hypoxia (2.11 mg O₂ L⁻¹; control: 6.96 mg O₂ 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.

  17. Effects of nutritional and environmental conditions on planktonic growth and biofilm formation of Citrobacter werkmanii BF-6.

    PubMed

    Zhou, Gang; Li, Long-jie; Shi, Qing-shan; Ouyang, You-sheng; Chen, Yi-ben; Hu, Wen-feng

    2013-12-01

    Citrobacter sp. is a cause of significant opportunistic nosocomial infection and is frequently found in human and animal feces, soil, and sewage water, and even in industrial waste or putrefaction. Biofilm formation is an important virulence trait of Citrobacter sp. pathogens but the process and characteristics of this formation are unclear. Therefore, we employed in vitro assays to study the nutritional and environmental parameters that might influence biofilm formation of C. werkmanii BF-6 using 96-well microtiter plates. In addition, we detected the relative transcript levels of biofilm formation genes by RT-PCR. Our results indicated that the capacity of C. werkmanii BF-6 to form biofilms was affected by culture temperature, media, time, pH, and the osmotic agents glucose, sucrose, NaCl, and KCl. Confocal laser scanning microscopy results illustrated that the structure of biofilms and extracellular polysaccharide was influenced by 100 mM NaCl or 100 mM KCl. In addition, nine biofilm formation genes (bsmA, bssR, bssS, csgD, csgE, csgF, mrkA, mrkB, and mrkE) were found to contribute to planktonic and biofilm growth. Our data suggest that biofilm formation by C. werkmanii BF-6 is affected by nutritional and environmental factors, which could pave the way to the prevention and elimination of biofilm formation using proper strategies.

  18. Effect of saline irrigation on growth characteristics and mineral composition of two local halophytes under Saudi environmental conditions.

    PubMed

    Alshammary, Saad F

    2008-09-01

    A field experiment was carried out to determine the growth characteristics and mineral composition of two local halophytes (Atriplex halimus and Salvadora persica) under saline irrigation at Kind Abdulaziz City for Science and Technology (KACST), Research Station Al-Muzahmyia, Riyadh. The experiment treatments were one soil (sandy), four irrigation waters of different salinities (2000, 8000, 12000 and 16000 mg L(-1) TDS), two halophytes (Salvadora persica and Atriplex halimus) and one irrigation level (irrigation at 50% depletion of moisture at field capacity). Mean fresh biomass yield and fresh plant root weight of A. halimus increased while that of S. persica decreased significantly with increasing irrigation water salinity in all the treatments. Soil salinity increased significantly with increasing water salinity. A positive correlation (r = 0.987) existed between the irrigation water salinity and the soil salinity resulting from saline irrigation. The plant tissue protein contents increased in A. halimus, but decreased in S. persica with increasing irrigation water salinity. The Na ion uptake by plant roots was significantly less than K in A. halimus compared to S. persica which indicated adjustment of plants to high soil salinity and high Na ion concentration for better growth. The order of increasing salt tolerance was A. halimus > S. persica under the existing plant growing conditions. Among the two halophytes, A. halimus showed great potential for establishing gene banks of local species, because it has more forage value due to high protein contents than S. persica for range animals.

  19. Overwintering growth and development of larval Euphausia superba: an interannual comparison under varying environmental conditions west of the Antarctic Peninsula

    NASA Astrophysics Data System (ADS)

    Daly, Kendra L.

    2004-08-01

    Growth, molting, and development of larval Antarctic krill were investigated near Marguerite Bay during four cruises in austral autumn and winter 2001 and 2002, as part of the US Southern Ocean GLOBEC program. Overwintering survival of larvae has been linked to annual sea-ice formation and extent, as sea-ice biota may provide food when other sources are scarce in the water column. During autumn 2001, larvae were very abundant (1-19 individuals m -3), with younger stages dominant offshelf and older stages dominant on-shelf. On-shelf larvae were in better condition than offshore larvae. During autumn 2002, larvae again were abundant offshelf (0.01-110 m -3), whereas all stages were scarce on-shelf. Declining diatom and radiolarian blooms were present during autumn in both years. Average chlorophyll concentrations were low (0.10 vs. 0.22 μg l -1) in autumn and an order of magnitude lower in winter. Carbon content of larvae during autumn 2001 and 2002 (41% vs. 38% C of DW) suggested that lipid storage was moderate. The median autumn larval growth rate (0.027 mm d -1) was lower and the intermolt period (19 d) longer than reported summer values. During winter, larvae appeared to be food-limited based on the following observations: (1) the median growth rate decreased (0.00 mm d -1) and the intermolt period increased (40 d), (2) larval length-specific dry weight (DW) and % carbon and nitrogen of DW decreased, and (3) 88% of furcilia 6 did not develop to the juvenile stage, but remained at the same stage after molting. Experimental results demonstrated that some larvae could survive starvation for a month by combusting body reserves (ca. 1% decrease in DW and body C and N d -1), implying that a portion of the population was resilient to the suboptimal food supply. Although sea ice formed up to 2 months earlier in 2002, ice algae at the ice-water interface, where it is accessible to krill, was not an abundant food source in either year (0.05 vs. 0.07 μg chl l -1). In

  20. Growth characteristics of the reef-building coral Porites astreoides under different environmental conditions in the Western Atlantic

    NASA Astrophysics Data System (ADS)

    Elizalde-Rendón, E. M.; Horta-Puga, G.; González-Diaz, P.; Carricart-Ganivet, J. P.

    2010-09-01

    Skeletal extension (3.67 ± 0.65 mm year-1), density (1.49 ± 0.16 g cm-3), and calcification rate (0.55 ± 0.12 g cm-2 year-1) were determined using annual growth bands of Porites astreoides skeletons collected in three different reef systems in the Western Atlantic. The corals showed a low-density annual growth band at their apex, and seasonal timing of low and high-density band formation in P. astreoides appears to be similar at the three study sites in the Western Atlantic. The range of values presented here, for the three growth variables, spans the known range of skeletal-growth variability in P. astreoides for the Western Atlantic. The relationships between the growth parameters were similar to those previously described by other authors for massive Porites species from the Indo-Pacific, suggesting that P. astreoides has the same growth strategy, primarily investing calcification resources in extension rate. It is noteworthy that the P. astreoides population growing off the northwest coast of Cuba had similar growth characteristics as populations from the Caribbean region which were different from populations in the Gulf of Mexico, which seem to be isolated and adapted for growth at higher average sea-surface temperatures.

  1. A "core-top" screen for trace element proxies of environmental conditions and growth rates in the calcite skeletons of bamboo corals (Isididae)

    NASA Astrophysics Data System (ADS)

    Thresher, Ronald E.; Fallon, Stewart J.; Townsend, Ashley T.

    2016-11-01

    We test for trace element proxies in the high-magnesium calcite fraction of bamboo coral internodes by comparing environmental conditions and growth rates to the specimen-mean compositions of 73 corals that were live-caught at depths ranging from 3 to 3950 m and collected from habitats ranging from tropical coral reefs to the Antarctic slope. Comparisons were done at a large geographic scale (LGS) and for a well sampled area south of Australia, across depths at a single site, in order to help separate the effects of environmental variables that co-vary at one spatial scale, but not the other. Thirty-seven trace elements were measured using solution-based Sector Field ICP-MS, of which seventeen were significantly detected in more than a third of the specimens. Only eight element/calcium ratios correlated significantly with any environmental variable at the large geographic scale, and only four did so at the local level. At the LGS, the highest correlation was between ambient temperature and Mg/Ca, which accounted for 89% of the variance across specimens, spanned all four Isidid sub-families and was independently significant in the two best sampled sub-families.

  2. Effects of environmental and biological conditions on the recruitment and growth of the Manila clam Ruditapes philippinarum on the west coast of Korea

    NASA Astrophysics Data System (ADS)

    Kim, Sang Lyeol; Kwon, Soon Hyun; Lee, Hyun Gon; Yu, Ok Hwan

    2017-01-01

    The distribution of the Manila clam Ruditapes philippinarum, which is often dominant in intertidal zones, is influenced by both environmental and biological conditions. However, there have been few comprehensive studies on the interactive effects of these two groups of factors. The present study examined the environmental and biological parameters determining the population dynamics of the clams that is a dominant component of the intertidal communities of Euhangri and Padori on the west coast of Korean peninsula. We collected R. philippinarum and other members of the macrobenthos (> 1 mm long) monthly from 0.25 m2 quadrats deployed in the intertidal zones at Euhangri, Taean, and Padori during the period from August 2013 to January 2015. Physicochemical parameters of the water and sediment were measured at the same time. Water temperature and salinity is high and low in the summer to winter, respectively. While mean grain size of the sediment was higher at Euhangri than at Padori, total mean density of R. philippinarum was higher at Euhangri (325 ind./ 0.25 m² at Padori vs. 194 ind./0.25 m² at Euhangri). Settled spat (< 10 mm in length) density was much higher at Euhangri than at Padori (132 vs. 12 individuals/0.25m2, respectively). R. philippinarum spats settled down on the sediment at Euhangri in October and grew continually until the following May, when they reached adult size. Spats that settled down at Padori between March and April were not able to reach the adult stage. As the density of the adult population increased, the condition index of individual clams decreased, but as the population density of the spat increased the body condition index increased. The chlorophyll a content of the sediments at Padori exceeded that at Euhangri and decreased as the population of R. philippinarum increased. The shapes of R. philippinarum shells at Euhangri were more prolate than those at Padori, and the condition index at Euhangri exceeded that at Padori, indicating

  3. Effects of environmental and biological conditions on the recruitment and growth of the Manila clam Ruditapes philippinarum on the west coast of Korea

    NASA Astrophysics Data System (ADS)

    Kim, Sang Lyeol; Kwon, Soon Hyun; Lee, Hyung-Gon; Yu, Ok Hwan

    2017-03-01

    The distribution of the Manila clam Ruditapes philippinarum, which is often dominant in intertidal zones, is influenced by both environmental and biological conditions. However, there have been few comprehensive studies on the interactive effects of these two groups of factors. The present study examined the environmental and biological parameters determining the population dynamics of the clams that is a dominant component of the intertidal communities of Euhangri and Padori on the west coast of Korean peninsula. We collected R. philippinarum and other members of the macrobenthos (> 1 mm long) monthly from 0.25 m2 quadrats deployed in the intertidal zones at Euhangri, Taean, and Padori during the period from August 2013 to January 2015. Physicochemical parameters of the water and sediment were measured at the same time. Water temperature and salinity is high and low in the summer to winter, respectively. While mean grain size of the sediment was higher at Euhangri than at Padori, total mean density of R. philippinarum was higher at Euhangri (325 ind./ 0.25 m2 at Padori vs. 194 ind./0.25 m2 at Euhangri). Settled spat (< 10 mm in length) density was much higher at Euhangri than at Padori (132 vs. 12 individuals/0.25m2, respectively). R. philippinarum spats settled down on the sediment at Euhangri in October and grew continually until the following May, when they reached adult size. Spats that settled down at Padori between March and April were not able to reach the adult stage. As the density of the adult population increased, the condition index of individual clams decreased, but as the population density of the spat increased the body condition index increased. The chlorophyll a content of the sediments at Padori exceeded that at Euhangri and decreased as the population of R. philippinarum increased. The shapes of R. philippinarum shells at Euhangri were more prolate than those at Padori, and the condition index at Euhangri exceeded that at Padori, indicating

  4. Conditioning biomass for microbial growth

    DOEpatents

    Bodie, Elizabeth A; England, George

    2015-03-31

    The present invention relates to methods for improving the yield of microbial processes that use lignocellulose biomass as a nutrient source. The methods comprise conditioning a composition comprising lignocellulose biomass with an enzyme composition that comprises a phenol oxidizing enzyme. The conditioned composition can support a higher rate of growth of microorganisms in a process. In one embodiment, a laccase composition is used to condition lignocellulose biomass derived from non-woody plants, such as corn and sugar cane. The invention also encompasses methods for culturing microorganisms that are sensitive to inhibitory compounds in lignocellulose biomass. The invention further provides methods of making a product by culturing the production microorganisms in conditioned lignocellulose biomass.

  5. Environmental impact of population growth

    NASA Astrophysics Data System (ADS)

    Naylor, Rosamond; Matson, Pamela

    Earth's population currently numbers 5.4 billion; even given optimistic assumptions for reduction in growth rates, the number will double by the middle of the next century with most of the increase in the developing countries. Rapid population growth in the developing world raises the fundamental dilemma of how to alleviate chronic hunger and poverty in the short run while preserving the atmosphere and ecosystem services required for long-term human and biospheric sustenance. This dilemma, and the compromises required to solve it, were discussed by twenty-five researchers from five countries at the Aspen Global Change Institute 1992 Summer Science Session III, Food, Conservation, and Global Environmental Change: Is Compromise Possible?, held from August 16 to 28, in Aspen, Colo.

  6. Metabolic and proteomic adaptation of Lactobacillus rhamnosus strains during growth under cheese-like environmental conditions compared to de Man, Rogosa, and Sharpe medium.

    PubMed

    Bove, Claudio Giorgio; De Angelis, Maria; Gatti, Monica; Calasso, Maria; Neviani, Erasmo; Gobbetti, Marco

    2012-11-01

    The aim of this study was to demonstrate the metabolic and proteomic adaptation of Lactobacillus rhamnosus strains, which were isolated at different stages of Parmigiano Reggiano cheese ripening. Compared to de Man, Rogosa, and Sharpe (MRS) broth, cultivation under cheese-like conditions (cheese broth, CB) increased the number of free amino acids used as carbon sources. Compared with growth on MRS or pasteurized and microfiltrated milk, all strains cultivated in CB showed a low synthesis of d,l-lactic acid and elevated levels of acetic acid. The proteomic maps of the five representative strains, showing different metabolic traits, were comparatively determined after growth on MRS and CB media. The amount of intracellular and cell-associated proteins was affected by culture conditions and diversity between strains, depending on their time of isolation. Protein spots showing decreased (62 spots) or increased (59 spot) amounts during growth on CB were identified using MALDI-TOF-MS/MS or LC-nano-ESI-MS/MS. Compared with cultivation on MRS broth, the L. rhamnosus strains cultivated under cheese-like conditions had modified amounts of some proteins responsible for protein biosynthesis, nucleotide, and carbohydrate metabolisms, the glycolysis pathway, proteolytic activity, cell wall, and exopolysaccharide biosynthesis, cell regulation, amino acid, and citrate metabolism, oxidation/reduction processes, and stress responses.

  7. Effect of environmental and cultural conditions on medium pH and explant growth performance of Douglas-fir ( Pseudotsuga menziesii) shoot cultures

    PubMed Central

    Chen, Chien-Chih; Bates, Rick; Carlson, John

    2015-01-01

    The medium pH level of plant tissue cultures has been shown to be essential to many aspects of explant development and growth. Sensitivity or tolerance of medium pH change in vitro varies according to specific requirements of individual species. The objectives of this study are to 1) determine medium pH change over time in storage conditions and with presence of explants, 2) evaluate the effects of medium pH change on explant growth performance and 3) assess the effects of adding a pH stabilizer, 2-(N-morpholino)ethanesulfonic acid (MES) that is commonly used in Douglas-fir micropropagation medium. Vegetative buds were collected in the spring before breaking dormancy from juvenile and mature donor trees for conducting these evaluations. Medium, with or without MES, was pre-adjusted to five pH levels before adding MES, agar and autoclaving. Medium pH changes and explant growth parameters were measured at eight different incubation times. Overall, MES provided a more stable medium pH, relative to starting pH values, under both light and dark storage conditions as well as with presence of explants. A general trend of decreasing medium pH over time was found comparing explants from juvenile and mature donor genotypes. Explant height and weight growth increased over time, but differ among explants from juvenile and mature donor genotypes. Our findings suggest that a 21-day subculture practice may best sustain medium freshness, medium pH level and desirable explant growth. PMID:26535110

  8. Effect of environmental and cultural conditions on medium pH and explant growth performance of Douglas-fir ( Pseudotsuga menziesii) shoot cultures.

    PubMed

    Chen, Chien-Chih; Bates, Rick; Carlson, John

    2014-01-01

    The medium pH level of plant tissue cultures has been shown to be essential to many aspects of explant development and growth. Sensitivity or tolerance of medium pH change in vitro varies according to specific requirements of individual species. The objectives of this study are to 1) determine medium pH change over time in storage conditions and with presence of explants, 2) evaluate the effects of medium pH change on explant growth performance and 3) assess the effects of adding a pH stabilizer, 2-(N-morpholino)ethanesulfonic acid (MES) that is commonly used in Douglas-fir micropropagation medium. Vegetative buds were collected in the spring before breaking dormancy from juvenile and mature donor trees for conducting these evaluations. Medium, with or without MES, was pre-adjusted to five pH levels before adding MES, agar and autoclaving. Medium pH changes and explant growth parameters were measured at eight different incubation times. Overall, MES provided a more stable medium pH, relative to starting pH values, under both light and dark storage conditions as well as with presence of explants. A general trend of decreasing medium pH over time was found comparing explants from juvenile and mature donor genotypes. Explant height and weight growth increased over time, but differ among explants from juvenile and mature donor genotypes. Our findings suggest that a 21-day subculture practice may best sustain medium freshness, medium pH level and desirable explant growth.

  9. Population growth and environmental degradation in Malawi.

    PubMed

    Kalipeni, E

    1992-01-01

    Malawi has been ranked by the World Bank as one of the poorest countries in Africa. Malawi's only resources are its people and fertile soil, which comprises about 55% of land area. Environmental degradation and population growth conditions in Malawi were used to illustrate the model of environmental degradation linked to population pressure on land resources and government development strategies that favored large-scale agricultural farms. The result has been deforestation, overgrazing, overuse of land for subsistence, and increased population density. The argument was that population growth in some developing countries has been so rapid that environmental collapse is the result. The theoretical framework linking population growth, environment, and resources emphasized processes: 1) the precursor stage of underlying causes; 2) the problem phase with potential ecological and economic decline; and 3) consequences (environmental decline, reduction in food production systems, and reduction in standard of living). The precursors were identified as an agrarian society, lack of a population policy, and emphasis on large families. The problems were rapid population growth and immigration from Mozambique, which led to increased demand for trees for fuel and consequent deforestation, increased demand for arable land and consequent landlessness, increased investment in livestock and consequent overgrazing, and continued population momentum which was a financial burden to government and resulted in increased labor competition. The ecological consequences were soil erosion, degradation of vegetation, and water supply contamination and decline. Eventually, famines will occur and lead to disease, migration, deserted villages, urbanization, unemployment, ethnic conflicts, and political unrest. Population was estimated at 8.75 million in 1990, with exponential growth expected. Completed family size was 6.6 children per woman. Even replacement fertility would mean growth for 50 more

  10. Flight in Adverse Environmental Condition

    DTIC Science & Technology

    1989-01-01

    mean wind Is rather difficult. Using earth fixed sensors , a temporal *vraging Is performed for each measuring point. Out the question for the right...netoorologiato and air chemists. Modern ai’rborno atmoopharic and environmental survey systems require not only airchemical sensors but alae a complete... sensor package for wind - and turbulence measurements. such a system is capable of performing the necessary in-situ Investigations to find out the

  11. Environmental boundary conditions of cold-water coral mound growth over the last 3 million years in the Porcupine Seabight, Northeast Atlantic

    NASA Astrophysics Data System (ADS)

    Raddatz, Jacek; Rüggeberg, Andres; Liebetrau, Volker; Foubert, Anneleen; Hathorne, Ed C.; Fietzke, Jan; Eisenhauer, Anton; Dullo, Wolf-Christian

    2014-01-01

    IODP Expedition 307 made it for the first time possible to investigate the entire body of a cold-water coral carbonate mound. Here we provide new insights into the long-term history of Challenger Mound on the European continental margin off Ireland. This study is based on age determinations (230Th/U, 87Sr/86Sr) and geochemical signals (Mg/Li and Ba/Ca) measured in the scleractinian cold-water coral Lophelia pertusa from IODP Site 1317 in the Porcupine Seabight. The paleoceanographic reconstructions reveal that coral growth in the Porcupine Seabight was restricted to specific oceanographic conditions such as enhanced export of primary production and Bottom-Water Temperatures (BWT) between ∼8 and 10 °C, related to the water mass stratification of the Mediterranean Outflow Water (MOW) and Eastern North Atlantic Water (ENAW). The geochemical signals from the coral skeletons can be explained by the close interaction between cold-water coral growth, sea-surface productivity and the surrounding water masses - the boundary layer between MOW and ENAW. Enhanced sea-surface productivity and the build-up of a stable water mass stratification between ENAW and MOW caused enhanced nutrient supply at intermediate water depths and facilitated a steady mound growth between ∼3.0 and 2.1 Ma. With the decrease in sea-surface productivity and related reduced export productivity the food supply was insufficient for rapid coral mound growth between ∼1.7 and 1 Ma. During the late Pleistocene (over the last ∼0.5 Myr) mound growth was restricted to interglacial periods. During glacials the water mass boundary between ENAW/MOW probably was below the mound summit and hence food supply was not sufficient for corals to grow.

  12. Differential effect of environmental conditions on the growth and regulation of the fumonisin biosynthetic gene FUM1 in the maize pathogens and fumonisin producers Fusarium verticillioides and Fusarium proliferatum.

    PubMed

    Marín, Patricia; Magan, Naresh; Vázquez, Covadonga; González-Jaén, María Teresa

    2010-08-01

    The effects of ecophysiological factors, temperature and solute potential, on both the growth and the regulation of the fumonisin biosynthetic FUM1 gene were studied and compared in one isolate each of the two closely related fumonisin-producing and maize pathogens Fusarium verticillioides and Fusarium proliferatum. The effect of solute potential and temperature was examined on in vitro mycelia growth and on the expression of the FUM1 gene, quantified by species-specific real-time reverse transcriptase-PCR assays. Although both isolates showed similar two-dimensional profiles of growth, for F. verticillioides, optimal growth conditions were maintained at higher temperatures and lower solute potential values. FUM1 gene expression was markedly induced at 20 degrees C in both isolates, under suboptimal conditions for growth; however, their expression patterns differed in relation to solute potential. Whereas FUM1 expression was induced in response to increasing water stress in the isolate of F. verticillioides, the F. proliferatum one showed a stable expression pattern regardless of water potential conditions. These results suggest a differential regulation of fumonisin biosynthesis in these isolates of the two species that might be related to their different host range, and play an ecological role. Additionally, environmental conditions leading to water stress (drought) might result in increased risk of fumonisin contamination of maize caused by F. verticillioides.

  13. Conflict Between Economic Growth and Environmental Protection

    SciTech Connect

    Czech, Bryan

    2012-01-09

    The conflict between economic growth and environmental protection may not be reconciled via technological progress. The fundamentality of the conflict ultimately boils down to laws of thermodynamics. Physicists and other scholars from the physical sciences are urgently needed for helping the public and policy makers grasp the conflict between growth and environmental protection.

  14. Economic Growth with Environmental Quality

    ERIC Educational Resources Information Center

    Environmental Science and Technology, 1977

    1977-01-01

    Producers of environmental control equipment have formed the Environmental Industry Council (EIC) in order to acquire a voice in the Washington legislative machinery. The Council is interested in changes in tax policy and in publicizing case histories where environmental controls have led to industrial savings. (BT)

  15. What environmental conditions encourage shallow mesoscale organization?

    NASA Astrophysics Data System (ADS)

    Wang, X.; Zuidema, P.

    2012-12-01

    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.

  16. Growth rate and TRI5 gene expression profiles of Fusarium equiseti strains isolated from Spanish cereals cultivated on wheat and barley media at different environmental conditions.

    PubMed

    Marín, Patricia; Jurado, Miguel; González-Jaén, M Teresa

    2015-02-16

    Fusarium equiseti is a toxigenic species that often contaminates cereal crops from diverse climatic regions such as Northern and Southern Europe. Previous results suggested the existence of two distinct populations within this species with differences in toxin profile which largely corresponded to North and South Europe (Spain). In this work, growth rate profiles of 4 F. equiseti strains isolated from different cereals and distinct Spanish regions were determined on wheat and barley based media at a range of temperatures (15, 20, 25, 30, 35 and 40°C) and water potential regimens (-0.7, -2.8, -7.0, and -9.8MPa, corresponding to 0.99, 0.98, 0.95 and 0.93 aw values). Growth was observed at all temperatures except at 40°C, and at all the solute potential values except at -9.8MPa when combined with 15°C. Optimal growth was observed at 20-30°C and -0.7/-2.8MPa. The effect of these factors on trichothecene biosynthesis was examined on a F. equiseti strain using a newly developed real time RT-PCR protocol to quantify TRI5 gene expression at 15, 25 and 35°C and -0.7, -2.8, -7.0 and -9.8MPa on wheat and barley based media. Induction of TRI5 expression was detected between 25 and 35°C and -0.7 and -2.8MPa, with maximum values at 35°C and -2.8MPa being higher in barley than in wheat medium. These results appeared to be consistent with a population well adapted to the present climatic conditions and predicted scenarios for Southern Europe and suggested some differences depending on the cereal considered. These are also discussed in relation to other Fusarium species co-occurring in cereals grown in this region and to their significance for prediction and control strategies of toxigenic risk in future scenarios of climate change for this region.

  17. Crops Models for Varying Environmental Conditions

    NASA Technical Reports Server (NTRS)

    Jones, Harry; Cavazzoni, James; Keas, Paul

    2001-01-01

    New variable environment Modified Energy Cascade (MEC) crop models were developed for all the Advanced Life Support (ALS) candidate crops and implemented in SIMULINK. The MEC models are based on the Volk, Bugbee, and Wheeler Energy Cascade (EC) model and are derived from more recent Top-Level Energy Cascade (TLEC) models. The MEC models simulate crop plant responses to day-to-day changes in photosynthetic photon flux, photoperiod, carbon dioxide level, temperature, and relative humidity. The original EC model allows changes in light energy but uses a less accurate linear approximation. The simulation outputs of the new MEC models for constant nominal environmental conditions are very similar to those of earlier EC models that use parameters produced by the TLEC models. There are a few differences. The new MEC models allow setting the time for seed emergence, have realistic exponential canopy growth, and have corrected harvest dates for potato and tomato. The new MEC models indicate that the maximum edible biomass per meter squared per day is produced at the maximum allowed carbon dioxide level, the nominal temperatures, and the maximum light input. Reducing the carbon dioxide level from the maximum to the minimum allowed in the model reduces crop production significantly. Increasing temperature decreases production more than it decreases the time to harvest, so productivity in edible biomass per meter squared per day is greater at nominal than maximum temperatures, The productivity in edible biomass per meter squared per day is greatest at the maximum light energy input allowed in the model, but the edible biomass produced per light energy input unit is lower than at nominal light levels. Reducing light levels increases light and power use efficiency. The MEC models suggest we can adjust the light energy day-to- day to accommodate power shortages or Lise excess power while monitoring and controlling edible biomass production.

  18. Crops Models for Varying Environmental Conditions

    NASA Technical Reports Server (NTRS)

    Jones, Harry; Cavazzoni, James; Keas, Paul

    2001-01-01

    New variable environment Modified Energy Cascade (MEC) crop models were developed for all the Advanced Life Support (ALS) candidate crops and implemented in SIMULINK. The MEC models are based on the Volk, Bugbee, and Wheeler Energy Cascade (EC) model and are derived from more recent Top-Level Energy Cascade (TLEC) models. The MEC models simulate crop plant responses to day-to-day changes in photosynthetic photon flux, photoperiod, carbon dioxide level, temperature, and relative humidity. The original EC model allows changes in light energy but uses a less accurate linear approximation. The simulation outputs of the new MEC models for constant nominal environmental conditions are very similar to those of earlier EC models that use parameters produced by the TLEC models. There are a few differences. The new MEC models allow setting the time for seed emergence, have realistic exponential canopy growth, and have corrected harvest dates for potato and tomato. The new MEC models indicate that the maximum edible biomass per meter squared per day is produced at the maximum allowed carbon dioxide level, the nominal temperatures, and the maximum light input. Reducing the carbon dioxide level from the maximum to the minimum allowed in the model reduces crop production significantly. Increasing temperature decreases production more than it decreases the time to harvest, so productivity in edible biomass per meter squared per day is greater at nominal than maximum temperatures, The productivity in edible biomass per meter squared per day is greatest at the maximum light energy input allowed in the model, but the edible biomass produced per light energy input unit is lower than at nominal light levels. Reducing light levels increases light and power use efficiency. The MEC models suggest we can adjust the light energy day-to- day to accommodate power shortages or Lise excess power while monitoring and controlling edible biomass production.

  19. Dynamic photosynthesis in different environmental conditions.

    PubMed

    Kaiser, Elias; Morales, Alejandro; Harbinson, Jeremy; Kromdijk, Johannes; Heuvelink, Ep; Marcelis, Leo F M

    2015-05-01

    Incident irradiance on plant leaves often fluctuates, causing dynamic photosynthesis. Whereas steady-state photosynthetic responses to environmental factors have been extensively studied, knowledge of dynamic modulation of photosynthesis remains scarce and scattered. This review addresses this discrepancy by summarizing available data and identifying the research questions necessary to advance our understanding of interactions between environmental factors and dynamic behaviour of photosynthesis using a mechanistic framework. Firstly, dynamic photosynthesis is separated into sub-processes related to proton and electron transport, non-photochemical quenching, control of metabolite flux through the Calvin cycle (activation states of Rubisco and RuBP regeneration, and post-illumination metabolite turnover), and control of CO₂ supply to Rubisco (stomatal and mesophyll conductance changes). Secondly, the modulation of dynamic photosynthesis and its sub-processes by environmental factors is described. Increases in ambient CO₂ concentration and temperature (up to ~35°C) enhance rates of photosynthetic induction and decrease its loss, facilitating more efficient dynamic photosynthesis. Depending on the sensitivity of stomatal conductance, dynamic photosynthesis may additionally be modulated by air humidity. Major knowledge gaps exist regarding environmental modulation of loss of photosynthetic induction, dynamic changes in mesophyll conductance, and the extent of limitations imposed by stomatal conductance for different species and environmental conditions. The study of mutants or genetic transformants for specific processes under various environmental conditions could provide significant progress in understanding the control of dynamic photosynthesis.

  20. Environmental Conditions in Kentucky's Penal Institutions

    ERIC Educational Resources Information Center

    Bell, Irving

    1974-01-01

    A state task force was organized to identify health or environmental deficiencies existing in Kentucky penal institutions. Based on information gained through direct observation and inmate questionnaires, the task force concluded that many hazardous and unsanitary conditions existed, and recommended that immediate action be given to these…

  1. Environmental Conditions in Kentucky's Penal Institutions

    ERIC Educational Resources Information Center

    Bell, Irving

    1974-01-01

    A state task force was organized to identify health or environmental deficiencies existing in Kentucky penal institutions. Based on information gained through direct observation and inmate questionnaires, the task force concluded that many hazardous and unsanitary conditions existed, and recommended that immediate action be given to these…

  2. Discerning environmental factors affecting current tree growth in Central Europe.

    PubMed

    Cienciala, Emil; Russ, Radek; Šantrůčková, Hana; Altman, Jan; Kopáček, Jiří; Hůnová, Iva; Štěpánek, Petr; Oulehle, Filip; Tumajer, Jan; Ståhl, Göran

    2016-12-15

    We examined the effect of individual environmental factors on the current spruce tree growth assessed from a repeated country-level statistical landscape (incl. forest) survey in the Czech Republic. An extensive set of variables related to tree size, competition, site characteristics including soil texture, chemistry, N deposition and climate was tested within a random-effect model to explain growth in the conditions of dominantly managed forest ecosystems. The current spruce basal area increment was assessed from two consecutive landscape surveys conducted in 2008/2009 and six years later in 2014/2015. Tree size, age and competition within forest stands were found to be the dominant explanatory variables, whereas the expression of site characteristics, environmental and climatic drives was weaker. The significant site variables affecting growth included soil C/N ratio and soil exchangeable acidity (pH KCl; positive response) reflecting soil chemistry, long-term N-deposition (averaged since 1975) in combination with soil texture (clay content) and Standardized Precipitation Index (SPI), a drought index expressing moisture conditions. Sensitivity of growth to N-deposition was positive, although weak. SPI was positively related to and significant in explaining tree growth when expressed for the growth season. Except SPI, no significant relation of growth was determined to altitude-related variables (temperature, growth season length). We identified the current spruce growth optimum at elevations about 800ma.s.l. or higher in the conditions of the country. This suggests that at lower elevations, limitation by a more pronounced water deficit dominates, whereas direct temperature limitation may concern the less frequent higher elevations. The mixed linear model of spruce tree growth explained 55 and 65% of the variability with fixed and random effects included, respectively, and provided new insights on the current spruce tree growth and factors affecting it within the

  3. Expression of the myostatin gene in the adductor muscle of the Pacific lion-paw scallop Nodipecten subnodosus in association with growth and environmental conditions.

    PubMed

    Morelos, Rosa M; Ramírez, José L; García-Gasca, Alejandra; Ibarra, Ana M

    2015-04-01

    The cDNA sequence of the myostatin gene in the Pacific lion-paw Nodipecten subnodosus (Ns-mstn) was characterized, and the temporal expression during grow-out was analyzed for the first time in a scallop. Ns-mstn encodes a 459-amino-acid protein in which two propeptide proteolytic sites were identified, the previously recognized (RSKR) and a second one at position 266-269 aa (RRKR). The alternative furin cleavage site could be related with post-translational processing, or it could be a tissue-specific mechanism for signaling activity. The Ns-mstn transcript was located by in situ hybridization in sarcomeres and around the nucleus of muscle fibers. The temporal expression analysis by qPCR in the adductor muscle showed that Ns-mstn expression was significantly different (P < 0.05) between months during the grow-out period, increasing largely during the summer months when both biomass and muscle weight did not increase or even decreased; muscle fiber size and number were found to decrease significantly. Exogenous and endogenous factors such as high temperature and low food availability, as well as gametogenesis and reproduction, can be associated with the growth pattern and Ns-mstn expression changes. Our results indicate that MSTN is involved in adductor muscle growth regulation in N. subnodosus as it occurs in vertebrate skeletal muscle although Ns-mstn expression in non-muscle organs/tissues suggests additional functions. © 2015 Wiley Periodicals, Inc.

  4. NOVELTY DETECTION UNDER CHANGING ENVIRONMENTAL CONDITIONS

    SciTech Connect

    H. SOHN; K. WORDER; C. R. FARRAR

    2001-04-01

    The primary objective of novelty detection is to examine a system's dynamic response to determine if the system significantly deviates from an initial baseline condition. In reality, the system is often subject to changing environmental and operation conditions that affect its dynamic characteristics. Such variations include changes in loading, boundary conditions, temperature, and moisture. Most damage diagnosis techniques, however, generally neglect the effects of these changing ambient conditions. Here, a novelty detection technique is developed explicitly taking into account these natural variations of the system in order to minimize false positive indications of true system changes. Auto-associative neural networks are employed to discriminate system changes of interest such as structural deterioration and damage from the natural variations of the system.

  5. Novelty detection under changing environmental conditions

    NASA Astrophysics Data System (ADS)

    Sohn, Hoon; Worden, Keith; Farrar, Charles R.

    2001-07-01

    The primary objective of novelty detection is to examine a system's dynamic response to determine if the system significantly deviates from an initial baseline condition. In reality, the system is often subject to changing environmental and operation conditions that affect its dynamic characteristics. Such variations include changes in loading, boundary conditions, temperature, and moisture. Most damage diagnosis techniques, however, generally neglect the effects of these changing ambient conditions. Here, a novelty detection technique is developed explicitly taking into account these natural variations of the system in order to minimize false positive indications of true system changes. Auto-associative neural networks are employed to discriminate system changes of interest such as structural deterioration and damage from the natural variations of the system.

  6. Evidence for environmentally enhanced forest growth

    PubMed Central

    Fang, Jingyun; Kato, Tomomichi; Guo, Zhaodi; Yang, Yuanhe; Hu, Huifeng; Shen, Haihua; Zhao, Xia; Kishimoto-Mo, Ayaka W.; Tang, Yanhong; Houghton, Richard A.

    2014-01-01

    Forests in the middle and high latitudes of the northern hemisphere function as a significant sink for atmospheric carbon dioxide (CO2). This carbon (C) sink has been attributed to two processes: age-related growth after land use change and growth enhancement due to environmental changes, such as elevated CO2, nitrogen deposition, and climate change. However, attribution between these two processes is largely controversial. Here, using a unique time series of an age-class dataset from six national forest inventories in Japan and a new approach developed in this study (i.e., examining changes in biomass density at each age class over the inventory periods), we quantify the growth enhancement due to environmental changes and its contribution to biomass C sink in Japan’s forests. We show that the growth enhancement for four major plantations was 4.0∼7.7 Mg C⋅ha−1 from 1980 to 2005, being 8.4–21.6% of biomass C sequestration per hectare and 4.1–35.5% of the country's total net biomass increase of each forest type. The growth enhancement differs among forest types, age classes, and regions. Our results provide, to our knowledge, the first ground-based evidence that global environmental changes can increase C sequestration in forests on a broad geographic scale and imply that both the traits and age of trees regulate the responses of forest growth to environmental changes. These findings should be incorporated into the prediction of forest C cycling under a changing climate. PMID:24979781

  7. [Standardised environmental conditions for neurocognitive laboratories].

    PubMed

    Matamoros-Tuma, M; Alvarez-González, M

    The exploration of neurocognition in neurology departments has gone a long way from the traditional psychometric tests to the present day use of high technology methods in cognitive neurophysiology, as is the case of event related potentials. Given the increased sensitivity of these procedures, it has become absolutely essential to control the influence of environmental variables that may exert non controlled effects on the patient s response. Many neurocognitive laboratories have been set up in premises in which the spatial layout and the environmental characteristics have been determined beforehand and consequently technical staff has had to prepare these rooms in an empirical way. This gives rise to two types of drawbacks: interferences in the patient s concentration and low reproducibility of the results in other laboratories. In this paper we present a proposed set of standardised conditions for a neurocognitive laboratory from an architectural perspective, and more specifically with regard to interior design. We outline the functional design of the premises, the conditions for workplaces where VDU computers (Video Display Units) are used and where psychometric evaluation is carried out. We also discuss the criteria to be followed when placing the laboratory within a hospital, lighting parameters, air conditioning and suggestions about psychological input. Although we do not seek to establish a rigid set of norms, these conditions will raise the quality of evaluations and facilitate the comparison of results because of the reduced variability from the environment.

  8. Optimal Culture Conditions for Mycelial Growth of Lignosus rhinocerus

    PubMed Central

    Siti Murni, M.J.; Fauzi, D.; Abas Mazni, O.; Saleh, N.M.

    2011-01-01

    Lignosus rhinocerus is a macrofungus that belongs to Polyporaceae and is native to tropical regions. This highly priced mushroom has been used as folk medicine to treat diseases by indigenous people. As a preliminary study to develop a culture method for edible mushrooms, the cultural characteristics of L. rhinocerus were investigated in a range of culture media under different environmental conditions. Mycelial growth of this mushroom was compared on culture media composed of various carbon and nitrogen sources in addition to C/N ratios. The optimal conditions for mycelial growth were 30℃ at pH 6 and 7. Rapid mycelial growth of L. rhinocerus was observed on glucose-peptone and yeast extract peptone dextrose media. Carbon and nitrogen sources promoting mycelial growth of L. rhinocerus were glucose and potassium nitrate, respectively. The optimum C/N ratio was approximately 10 : 1 using 2% glucose supplemented as a carbon source in the basal media. PMID:22783083

  9. Optimal Culture Conditions for Mycelial Growth of Lignosus rhinocerus.

    PubMed

    Lai, W H; Siti Murni, M J; Fauzi, D; Abas Mazni, O; Saleh, N M

    2011-06-01

    Lignosus rhinocerus is a macrofungus that belongs to Polyporaceae and is native to tropical regions. This highly priced mushroom has been used as folk medicine to treat diseases by indigenous people. As a preliminary study to develop a culture method for edible mushrooms, the cultural characteristics of L. rhinocerus were investigated in a range of culture media under different environmental conditions. Mycelial growth of this mushroom was compared on culture media composed of various carbon and nitrogen sources in addition to C/N ratios. The optimal conditions for mycelial growth were 30℃ at pH 6 and 7. Rapid mycelial growth of L. rhinocerus was observed on glucose-peptone and yeast extract peptone dextrose media. Carbon and nitrogen sources promoting mycelial growth of L. rhinocerus were glucose and potassium nitrate, respectively. The optimum C/N ratio was approximately 10 : 1 using 2% glucose supplemented as a carbon source in the basal media.

  10. Cross-taxon congruence and environmental conditions.

    PubMed

    Toranza, Carolina; Arim, Matías

    2010-07-16

    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. 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. Our study corroborates the main role of environmental conditions on diversity patterns, but suggests that other important mechanisms, which

  11. Cross-taxon congruence and environmental conditions

    PubMed Central

    2010-01-01

    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

  12. CTOD for slow stable crack growth conditions

    NASA Astrophysics Data System (ADS)

    Perez Ipina, J. E.

    1992-11-01

    An incremental method is developed for calculating values of CTOD under slow stable crack growth conditions. The method, which only needs the data required for an R-curve test, gives more accurate CTOD values than those obtained using existing standards.

  13. Changes in Environmental Conditions Modify Infection Kinetics of Dairy Phages.

    PubMed

    Zaburlin, Delfina; Quiberoni, Andrea; Mercanti, Diego

    2017-04-08

    Latent period, burst time, and burst size, kinetic parameters of phage infection characteristic of a given phage/host system, have been measured for a wide variety of lactic acid bacteria. However, most studies to date were conducted in optimal growth conditions of host bacteria and did not consider variations due to changes in external factors. In this work, we determined the effect of temperature, pH, and starvation on kinetic parameters of phages infecting Lactobacillus paracasei, Lactobacillus plantarum, and Leuconostoc mesenteroides. For kinetics assessment, one-step growth curves were carried out in MRS broth at optimal conditions (control), lower temperature, pH 6.0 and 5.0 (MRS6 and MRS5, respectively), or in medium lacking carbon (MRSN) or nitrogen (MRSC) sources. Phage infection was progressively impaired as environmental conditions were modified from optimal. At lower temperature or pH, infection was delayed, as perceived by longer latent and burst times. Burst size, however, was lower, equal or higher than for controls, but this effect was highly dependent on the particular phage-host system studied. Phage infection was strongly inhibited in MRSC, but only mildly impaired in MRSN. Nevertheless, growth of all the bacterial strains tested was severely compromised by starvation, without significant differences between MRSC and MRSN, indicating that nitrogen compounds are specifically required for a successful phage infection, beyond their influence on bacterial growth.

  14. Microaerophilic Conditions Promote Growth of Mycobacterium genavense

    PubMed Central

    Realini, L.; De Ridder, K.; Palomino, J.-C.; Hirschel, B.; Portaels, F.

    1998-01-01

    Our studies show that microaerophilic conditions promote the growth of Mycobacterium genavense in semisolid medium. The growth of M. genavense at 2.5 or 5% oxygen was superior to that obtained at 21% oxygen in BACTEC primary cultures (Middlebrook 7H12, pH 6.0, without additives). By using nondecontaminated specimens, it was possible to detect growth with very small inocula (25 bacilli/ml) of 12 different M. genavense strains (from nude mice) within 6 weeks of incubation under low oxygen tension; conversely, with 21% oxygen, no growth of 8 of 12 (66.7%) M. genavense strains was detected (growth index, <10). The same beneficial effect of 2.5 or 5% oxygen was observed in primary cultures of a decontaminated clinical specimen. Low oxygen tension (2.5 or 5%) is recommended for the primary isolation of M. genavense. Microaerophilic cultivation of other atypical mycobacteria, especially slow-growing (e.g., Mycobacterium avium) and difficult-to-grow (e.g., Mycobacterium ulcerans) species, is discussed. PMID:9705393

  15. Environmental Effects on Fatigue Crack Growth in 7075 Aluminum Alloy

    NASA Astrophysics Data System (ADS)

    Bonakdar, A.; Wang, F.; Williams, J. J.; Chawla, N.

    2012-08-01

    The fatigue behavior of aluminum alloys is greatly influenced by the environmental conditions. In this article, fatigue crack growth rates were measured for 7075-T651 Al alloy under ultrahigh vacuum (UHV, ~10-10 Torr), dry air, and water vapor. Standard compact tension (CT) specimens were tested along the L-T orientation under various load ratios of 0.1, 0.5, and 0.8. Fracture surfaces and crack morphologies were studied using scanning electron microscopy and crack deflection analysis. The crack growth behavior under vacuum was affected by friction and possible rewelding of crack surfaces, causing an asymmetry in the crack growth behavior, from load shedding to constant load. The enhancement of crack growth at higher moisture levels was observed and is discussed in terms of moisture decreasing friction between the crack faces. The effect of crack deflection as a function of R ratio and environment is also presented.

  16. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Environmental conditions. 50.36b Section 50.36b Energy... § 50.36b Environmental conditions. (a) Each construction permit under this part, each early site permit... conditions will be derived from information contained in the environmental report submitted pursuant to § 51...

  17. 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...

  18. 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...

  19. [Guidelines on asthma in extreme environmental conditions].

    PubMed

    Drobnic, Franchek; Borderías Clau, Luis

    2009-01-01

    Asthma is a highly prevalent chronic disease which, if not properly controlled, can limit the patient's activities and lifestyle. In recent decades, owing to the diffusion of educational materials, the application of clinical guidelines and, most importantly, the availability of effective pharmacological treatment, most patients with asthma are now able to lead normal lives. Significant social changes have also taken place during the same period, including more widespread pursuit of sporting activities and tourism. As a result of these changes, individuals with asthma can now participate in certain activities that were inconceivable for these patients only a few years ago, including winter sports, underwater activities, air flight, and travel to remote places with unusual environmental conditions (deserts, high mountain environments, and tropical regions). In spite of the publication of several studies on this subject, our understanding of the effects of these situations on patients with asthma is still limited. The Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) has decided to publish these recommendations based on the available evidence and expert opinion in order to provide information on this topic to both doctors and patients and to avert potentially dangerous situations that could endanger the lives of these patients.

  20. Growth kinetics of coliform bacteria under conditions relevant to drinking water distribution systems.

    PubMed

    Camper, A K; McFeters, G A; Characklis, W G; Jones, W L

    1991-08-01

    The growth of environmental and clinical coliform bacteria under conditions typical of drinking water distribution systems was examined. Four coliforms (Klebsiella pneumoniae, Escherichia coli, Enterobacter aerogenes, and Enterobacter cloacae) were isolated from an operating drinking water system for study; an enterotoxigenic E. coli strain and clinical isolates of K. pneumoniae and E. coli were also used. All but one of the coliforms tested were capable of growth in unsupplemented mineral salts medium; the environmental isolates had greater specific growth rates than did the clinical isolates. This trend was maintained when the organisms were grown with low levels (less than 1 mg liter-1) of yeast extract. The environmental K. pneumoniae isolate had a greater yield, higher specific growth rates, and a lower Ks value than the other organisms. The environmental E. coli and the enterotoxigenic E. coli strains had comparable yield, growth rate, and Ks values to those of the environmental K. pneumoniae strain, and all three showed significantly more successful growth than the clinical isolates. The environmental coliforms also grew well at low temperatures on low concentrations of yeast extract. Unsupplemented distribution water from the collaborating utility supported the growth of the environmental isolates. Growth of the K. pneumoniae water isolate was stimulated by the addition of autoclaved biofilm but not by tubercle material. These findings indicate that growth of environmental coliforms is possible under the conditions found in operating municipal drinking water systems and that these bacteria could be used in tests to determine assimilable organic carbon in potable water.

  1. Protection of chemolithoautotrophic bacteria exposed to simulated Mars environmental conditions

    NASA Astrophysics Data System (ADS)

    Gómez, Felipe; Mateo-Martí, Eva; Prieto-Ballesteros, Olga; Martín-Gago, Jose; Amils, Ricardo

    2010-10-01

    Current surface conditions (strong oxidative atmosphere, UV radiation, low temperatures and xeric conditions) on Mars are considered extremely challenging for life. The question is whether there are any features on Mars that could exert a protective effect against the sterilizing conditions detected on its surface. Potential habitability in the subsurface would increase if the overlaying material played a protective role. With the aim of evaluating this possibility we studied the viability of two microorganisms under different conditions in a Mars simulation chamber. An acidophilic chemolithotroph isolated from Río Tinto belonging to the Acidithiobacillus genus and Deinococcus radiodurans, a radiation resistant microorganism, were exposed to simulated Mars conditions under the protection of a layer of ferric oxides and hydroxides, a Mars regolith analogue. Samples of these microorganisms were exposed to UV radiation in Mars atmospheric conditions at different time intervals under the protection of 2 and 5 mm layers of oxidized iron minerals. Viability was evaluated by inoculation on fresh media and characterization of their growth cultures. Here we report the survival capability of both bacteria to simulated Mars environmental conditions.

  2. Adversarial Growth in Telephone Counsellors: Psychological and Environmental Influences

    ERIC Educational Resources Information Center

    O'Sullivan, Julian; Whelan, Thomas A.

    2011-01-01

    The aims of this study were to investigate the level of adversarial growth among telephone counsellors, and to examine the influence of psychological and environmental factors on growth. In particular, the effect of compassion fatigue, empathy, environmental support and calls per shift on posttraumatic growth was assessed. Sixty-four telephone…

  3. Adversarial Growth in Telephone Counsellors: Psychological and Environmental Influences

    ERIC Educational Resources Information Center

    O'Sullivan, Julian; Whelan, Thomas A.

    2011-01-01

    The aims of this study were to investigate the level of adversarial growth among telephone counsellors, and to examine the influence of psychological and environmental factors on growth. In particular, the effect of compassion fatigue, empathy, environmental support and calls per shift on posttraumatic growth was assessed. Sixty-four telephone…

  4. Modeling Hematite Bioreduction under Growth Conditions

    NASA Astrophysics Data System (ADS)

    Yu, J.; Chen, C.; Yeh, G.; Burgos, W. D.; Mynyard, M. L.

    2004-12-01

    The focus of this work is on simulating and analyzing bioreduction kinetics of natural hematite-coated sand by dissimilatory metal-reducing bacterium (DMRB), Shewanella putrefaciens CN32, under growth conditions with lactate as the electron donor. A reaction-based biogeochemical model was used. A series of batch experiments with different initial conditions were performed to determine the rate formulations/parameters for hematite bioreduction and related reactions. Three different kinetic reaction rate formations were used to model hematite bioreduction. The consistency of mass conservation equations was assessed. Assumptions regarding equilibrium reactions were also assessed. Column experiments focused on transient reactive transport were conducted under otherwise identical conditions, except that the flow rate was systematically varied. The determined rate formulations/parameters were systematically tested with these column experiments using a reactive biogeochemical transport model that coupled hydrologic transport and reactive biogeochemistry. The model simulated the hematite bioreduction of hematite-coated sand in column experiments reasonably well using rate formulation/parameters determined from batch experiments. This study supports the hypothesis that mechanistic-based reaction rates of batch experiments can be scaled up and ported to column experiments.

  5. Mineral losses during extreme environmental conditions

    USDA-ARS?s Scientific Manuscript database

    Minerals are nutrients that are conserved by the body. During exposure to environmental stimuli, such as heat and/or exercise, the excretion of minerals, macro (Na, K, Ca, Mg) and micro (Cu, Fe, Zn), occurs through the body surface in the form of cellular desquamation and sweat, as well as in the u...

  6. Analysis of Environmental Stress Factors Using an Artificial Growth System and Plant Fitness Optimization

    PubMed Central

    Lee, Meonghun; Yoe, Hyun

    2015-01-01

    The environment promotes evolution. Evolutionary processes represent environmental adaptations over long time scales; evolution of crop genomes is not inducible within the relatively short time span of a human generation. Extreme environmental conditions can accelerate evolution, but such conditions are often stress inducing and disruptive. Artificial growth systems can be used to induce and select genomic variation by changing external environmental conditions, thus, accelerating evolution. By using cloud computing and big-data analysis, we analyzed environmental stress factors for Pleurotus ostreatus by assessing, evaluating, and predicting information of the growth environment. Through the indexing of environmental stress, the growth environment can be precisely controlled and developed into a technology for improving crop quality and production. PMID:25874206

  7. Brachiopods recording environmental conditions and biomineralisation processes

    NASA Astrophysics Data System (ADS)

    Cusack, Maggie; MacDonald, John M.; Fitzer, Susan C.; John, Cedric M.

    2016-04-01

    For around 550 million years, organisms have been exerting biological control on biomineral formation, generating elegant functional biomineral structures from basic components such as calcium phosphate in the case of vertebrate skeletons; silica or calcium carbonate in invertebrate shells and corals. In the marine realm, environmental information on the world's oceans is entrapped within the composition of calcium carbonate biomineral structures such as the shells of molluscs or brachiopods. Here, conventional stable and clumped isotopes of calcium carbonate of brachiopod shells are explored in the context of biological control. The aim is to ensure the correct interpretation of environmental data and to consider the possibility of extracting information on the mechanisms of biomineralisation processes from the data stored in the fossil record.

  8. Xeml Lab: a tool that supports the design of experiments at a graphical interface and generates computer-readable metadata files, which capture information about genotypes, growth conditions, environmental perturbations and sampling strategy.

    PubMed

    Hannemann, Jan; Poorter, Hendrik; Usadel, Björn; Bläsing, Oliver E; Finck, Alex; Tardieu, Francois; Atkin, Owen K; Pons, Thijs; Stitt, Mark; Gibon, Yves

    2009-09-01

    Data mining depends on the ability to access machine-readable metadata that describe genotypes, environmental conditions, and sampling times and strategy. This article presents Xeml Lab. The Xeml Interactive Designer provides an interactive graphical interface at which complex experiments can be designed, and concomitantly generates machine-readable metadata files. It uses a new eXtensible Mark-up Language (XML)-derived dialect termed XEML. Xeml Lab includes a new ontology for environmental conditions, called Xeml Environment Ontology. However, to provide versatility, it is designed to be generic and also accepts other commonly used ontology formats, including OBO and OWL. A review summarizing important environmental conditions that need to be controlled, monitored and captured as metadata is posted in a Wiki (http://www.codeplex.com/XeO) to promote community discussion. The usefulness of Xeml Lab is illustrated by two meta-analyses of a large set of experiments that were performed with Arabidopsis thaliana during 5 years. The first reveals sources of noise that affect measurements of metabolite levels and enzyme activities. The second shows that Arabidopsis maintains remarkably stable levels of sugars and amino acids across a wide range of photoperiod treatments, and that adjustment of starch turnover and the leaf protein content contribute to this metabolic homeostasis.

  9. Plant growth conditions alter phytolith carbon

    PubMed Central

    Gallagher, Kimberley L.; Alfonso-Garcia, Alba; Sanchez, Jessica; Potma, Eric O.; Santos, Guaciara M.

    2015-01-01

    Many plants, including grasses and some important human food sources, accumulate, and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM) that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin, and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a “glass wastebasket.” Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins, and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction. PMID:26442066

  10. Plant growth conditions alter phytolith carbon.

    PubMed

    Gallagher, Kimberley L; Alfonso-Garcia, Alba; Sanchez, Jessica; Potma, Eric O; Santos, Guaciara M

    2015-01-01

    Many plants, including grasses and some important human food sources, accumulate, and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM) that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin, and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a "glass wastebasket." Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins, and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction.

  11. Is Decoupling GDP Growth from Environmental Impact Possible?

    PubMed

    Ward, James D; Sutton, Paul C; Werner, Adrian D; Costanza, Robert; Mohr, Steve H; Simmons, Craig T

    2016-01-01

    The argument that human society can decouple economic growth-defined as growth in Gross Domestic Product (GDP)-from growth in environmental impacts is appealing. If such decoupling is possible, it means that GDP growth is a sustainable societal goal. Here we show that the decoupling concept can be interpreted using an easily understood model of economic growth and environmental impact. The simple model is compared to historical data and modelled projections to demonstrate that growth in GDP ultimately cannot be decoupled from growth in material and energy use. It is therefore misleading to develop growth-oriented policy around the expectation that decoupling is possible. We also note that GDP is increasingly seen as a poor proxy for societal wellbeing. GDP growth is therefore a questionable societal goal. Society can sustainably improve wellbeing, including the wellbeing of its natural assets, but only by discarding GDP growth as the goal in favor of more comprehensive measures of societal wellbeing.

  12. Growth of single crystals under hydrothermal conditions

    NASA Astrophysics Data System (ADS)

    Popolitov, Vladislav Ivanovich; Litvin, Boris Nikolaevich

    The book summarizes the available theoretical, methodological, and experimental data on the hydrothermal growth of inorganic compounds, such as simple and complex oxides, sulfides, silicates, germanates, phosphates, niobates, and tantalates. Attention is given to the physicochemical, hydrodynamic, and kinetic characteristics of the growth of these compounds, as well as hydrothermal growth techniques and equipment. The discussion also covers the morphogenetic characteristics of hydrothermally grown single crystals, their principal physical properties, and X-ray diffraction and structural data.

  13. Growth of Corophium volutator under laboratory conditions.

    PubMed

    Kater, Belinda J; Jol, Johan G; Smit, Mathijs G D

    2008-04-01

    Temperature-dependent growth is an important factor in the population model of Corophium volutator that was developed to translate responses in a 10-day acute bioassay to ecological consequences for the population. The growth rate, however, was estimated from old data, based on a Swedish population. Therefore, new growth rates are estimated herein from two experiments using Corophium volutator. To save time, a tool was developed to use image analysis to measure Corophium volutator. The experiments show that Corophium volutator has a low growth rate at low temperatures (5-10 degrees C). At higher temperatures no difference in growth rate between 15 degrees C and 25 degrees C was found. The growth rate from these experiments is comparable to data found in literature. A new relationship between temperature and individual growth was estimated, and incorporated into the Corophium population model. As the model also uses the same temperature relationship for reproduction, the modelled population growth rate at different temperatures changes as a result of the new data. The new growth rate and the updated temperature relationship result in reduced tolerance to external stressors, as previously predicted by the model.

  14. Solidification under microgravity conditions - Dendritic growth

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.; Hahn, R. C.; Lograsso, T. A.; Rubinstein, E. R.; Winsa, E.

    1987-01-01

    The experimental approach and apparatus of a zero-gravity active crystal growth experiment to test dendritic growth theory at low supercoolings are discussed. The experiment consists of 20 experimental cycles. Estimates have been made as to how low gravitational accelerations would have to be reduced to observe convection-free dendritic growth at supercoolings from 0.01-1.0 K. The experiment requires temperature control of + or - 2 mK and photographic resolution of a few microns with a depth of field of + or - 6 mm. The thermostatic bath and temperature control system, photographic system, growth chamber, and dendrite detection system are described in detail.

  15. Is Decoupling GDP Growth from Environmental Impact Possible?

    PubMed Central

    Sutton, Paul C.; Werner, Adrian D.; Costanza, Robert; Mohr, Steve H.; Simmons, Craig T.

    2016-01-01

    The argument that human society can decouple economic growth—defined as growth in Gross Domestic Product (GDP)—from growth in environmental impacts is appealing. If such decoupling is possible, it means that GDP growth is a sustainable societal goal. Here we show that the decoupling concept can be interpreted using an easily understood model of economic growth and environmental impact. The simple model is compared to historical data and modelled projections to demonstrate that growth in GDP ultimately cannot be decoupled from growth in material and energy use. It is therefore misleading to develop growth-oriented policy around the expectation that decoupling is possible. We also note that GDP is increasingly seen as a poor proxy for societal wellbeing. GDP growth is therefore a questionable societal goal. Society can sustainably improve wellbeing, including the wellbeing of its natural assets, but only by discarding GDP growth as the goal in favor of more comprehensive measures of societal wellbeing. PMID:27741300

  16. Lunar Polar Environmental Testing: Regolith Simulant Conditioning

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie

    2014-01-01

    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.

  17. Management of Cattle Exposed to Adverse Environmental Conditions.

    PubMed

    Mader, Terry L; Griffin, Dee

    2015-07-01

    During periods of adverse weather, optimum conditions for animal comfort and performance are compromised. Use of alternative supplementation programs 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 winter, strategies that increase animal space and environmental buffers need to be used to minimize effects of mud, wet conditions, and windchill. There are ample opportunities for livestock producers to enhance animal welfare and minimize the impact of environmental stress.

  18. Eddy correlation measurements in wet environmental conditions

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

    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

  19. 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...

  20. 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...

  1. Growth management of vetiver (Vetiveria zizanioides) under Mediterranean conditions.

    PubMed

    Dudai, N; Putievsky, E; Chaimovitch, D; Ben-Hur, M

    2006-10-01

    In spite of the advantages of Vetiver grass in light of environmental aspects, this plant is not used in the Mediterranean region. The objectives of the present study were: (i) to elucidate growth parameters and establishment of Vetiver under Mediterranean conditions suitable for its various environmental applications; and (ii) to develop management practices for growing vetiver under Mediterranean conditions. In greenhouse experiments conducted under controlled conditions it was found that, in general, increasing the minimum/maximum temperatures to 21-29 degrees C significantly increased plant height. In the Mediterranean region, this range of air temperatures is obtained mainly during the summer, from June to September. For air temperatures up to 15-23 degrees C the effect of day length on plant height was insignificant, whereas in air temperature >15-23 degrees C, the plant heights under long day conditions were significantly higher than under short day. The number of sprouts per plant increased exponentially with increasing air temperature, and was not significantly affected by the day length at any air temperature range. In open fields, the heights of irrigated vetiver plants were significantly higher than those of rain-fed plants. It was concluded that, once they were established, vetiver plants could survive the dry summer of the Mediterranean region under rain-fed conditions, but they would be shorter than under irrigation. Cutting or burning of the plant foliage during the spring did not improve the survival of vetiver during the dry summer. In order to obtain fast growth of vetiver and to increase the possibility of its using the rainwater, the plants should be planted in the winter, during February and March. However, under this regime, the vetiver plant cannot be used as a soil stabilizer during the first winter, because the plant is still small. In contrast, under irrigation it is advantageous to plant vetiver at the beginning of the summer; the plant

  2. Overview of environmental and hydrogeologic conditions at King Salmon, Alaska

    USGS Publications Warehouse

    Waythomas, C.F.

    1994-01-01

    The Federal Aviation Administration is conducting preliminary environmental assessments at most of its present or former facilities in Alaska. Information about environmental conditions at King Salmon, Alaska are presented in this report. This report gives an overview of the geology, hydro- logy, and climate of the King Salmon area and describes general geohydrologic conditions. A thick alluvial aquifer underlies King Salmon and both ground water and surface water are plentiful in the area.

  3. Affluence and objective environmental conditions: Evidence of differences in environmental concern in metropolitan Brazil

    PubMed Central

    Nawrotzki, Raphael J.; Guedes, Gilvan; do Carmo, Roberto Luiz

    2016-01-01

    In an age of climate change, researchers need to form a deepened understanding of the determinants of environmental concern, particularly in countries of emerging economies. This paper provides a region-specific investigation of the impact of socio-economic status (SES) and objective environmental conditions on environmental concern in urban Brazil. We make use of data that were collected from personal interviews of individuals living in the metropolitan areas of Baixada Santista and Campinas, in the larger São Paulo area. Results from multilevel regression models indicate that wealthier households are more environmentally concerned, as suggested by affluence and post-materialist hypotheses. However, we also observe that increasing environmental concern correlates with a decline in objective environmental conditions. Interactions between objective environmental conditions and SES reveal some intriguing relationships: Among poorer individuals, a decline in environmental conditions increases environmental concern as suggested by the objective problems hypothesis, while for the wealthy, a decline in environmental conditions is associated with lower levels of environmental concern. PMID:27594931

  4. Environmental enrichment does not impact on tumor growth in mice

    PubMed Central

    Kershaw, Michael H

    2013-01-01

    The effect of environmental enrichment (EE) on a variety of physiologic and disease processes has been studied in laboratory mice. During EE, a large group of mice are housed in larger cages than the standard cage and are given toys and equipment, enabling more social contact, and providing a greater surface area per mouse, and a more stimulating environment. Studies have been performed into the effect of EE on neurogenesis, brain injury, cognitive capacity, memory, learning, neuronal pathways, diseases such as Alzheimer’s, anxiety, social defeat, emotionality, depression, drug addiction, alopecia, and stereotypies. In the cancer field, three papers have reported effects on mice injected with tumors and housed in enriched environments compared with those housed in standard conditions. One paper reported a significant decrease in tumor growth in mice in EE housing. We attempted to replicate this finding in our animal facility, because the implications of repeating this finding would have profound implications for how we house all our mice in our studies on cancer. We were unable to reproduce the results in the paper in which B16F10 subcutaneous tumors of mice housed in EE conditions were smaller than those of mice housed in standard conditions. The differences in results could have been due to the different growth rate of the B16F10 cultures from the different laboratories, the microbiota of the mice housed in the two animal facilities, variations in noise and handling between the two facilities, food composition, the chemical composition of the cages or the detergents used for cleaning, or a variety of other reasons. EE alone does not appear to consistently result in decreased tumor growth, but other factors would appear to be able to counteract or inhibit the effects of EE on cancer progression. PMID:24555065

  5. Environmental Enteropathy: Critical implications of a poorly understood condition

    PubMed Central

    Korpe, Poonum S.; Petri, William A.

    2012-01-01

    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

  6. Effects of diverse environmental conditions on {phi}LC3 prophage stability in Lactococcus lactis.

    PubMed

    Lunde, Merete; Aastveit, Are Halvor; Blatny, Janet Martha; Nes, Ingolf F

    2005-02-01

    The effects of various growth conditions on spontaneous phiLC3 prophage induction in Lactococcus lactis subsp. cremoris IMN-C1814 was analyzed with a half fraction of a 4(4) factorial experimental design. The four factors included in the study were nutrient availability, acidity, osmolarity, and temperature, each applied at four levels. These environmental factors are related to the fermentation processes in the dairy industry, in which bacteriophage attacks on sensitive starter strains are a constant threat to successful fermentation processes. The frequency of spontaneous phiLC3 induction was determined by quantitative analyses of restored DNA attachment sites (attB) on the bacterial chromosomes in a population of lysogenic cells. Statistical analysis revealed that all four environmental factors tested affected phiLC3 prophage stability and that the environmental factors were involved in interactions (interactions exist when the effect of one factor depends on the level of another factor). The spontaneous phiLC3 induction frequency varied from 0.08 to 1.76%. In general, the induction frequency remained at the same rate or decreased when level 1 to 3 of the four environmental factors was applied. At level 4, which generally gave the least favorable growth conditions, the induction frequency was either unchanged, decreased, or increased, depending on the type of stress. It appeared that the spontaneous induction frequency was independent of the growth behavior of the host. It was the environmental growth conditions that were the decisive factor in induction frequency.

  7. Oceanographic conditions govern shell growth of Arctica islandica (Bivalvia) in surface waters off Northeast Iceland

    NASA Astrophysics Data System (ADS)

    Marali, Soraya; Schöne, Bernd R.

    2015-04-01

    Shells of the long-lived bivalve Arctica islandica provide absolutely dated, highly resolved archives of environmental variability in the extratropical realm. Shell growth rates of contemporaneous A. islandica specimens are synchronized by one or several environmental factor(s), such as seawater temperature, food supply etc. Based on the growth synchrony, increment width records can be combined to composite chronologies. However, according to existing studies, A. islandica specimens from shallow waters do not show synchronous changes in shell growth and may thus not provide information about environmental conditions such as sea surface temperature. Here, we present the first statistically robust composite chronology of A. islandica from unpolluted surface waters (8-23 m) off Northeast Iceland. The complete record spans the time interval of 1835 to 2012. Times of enhanced shell growth coincide with periods of higher temperature and elevated food supply. Instrumental sea surface temperature (SST) during the growing season explains up to 43% of the variation in relative shell growth. However, the correlation strength varies over time. When the environmental conditions at the sampling site were stable over many consecutive years, i.e. one of the two major surface currents (the warm, nutrient-rich Irminger Current or the cold, nutrient-deficient East Icelandic Current) predominated the area over longer time intervals, the growth synchrony among coeval A. islandica weakened and the correlation between shell growth and SSTs was markedly reduced. Conversely, if the habitat was under the alternating influence of both ocean currents, shell growth was stronger correlated to each other and to SST. Thus, environmental variability is required to synchronize shell growth rates within an A. islandica population. This study further enlightens the relationship between bivalve shell growth and environmental variables.

  8. Environmental embrittlement of iron aluminides under cyclic loading conditions

    SciTech Connect

    Castagna, A.; Alven, D.A.; Stoloff, N.S.

    1995-08-01

    The tensile and fatigue crack growth behavior in air in hydrogen and in oxygen of an Fe-Al-Cr-Zr alloy is described. The results are compared to data for FA-129. A detailed analysis of frequency effects on fatigue crack growth rates of FA-129, tested in the B2 condition, shows that dislocation transport of hydrogen from the surface is the rate limiting step in fatigue crack growth.

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

    PubMed Central

    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

    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

  10. Support for Economic Growth and Environmental Protection 1973-1975.

    ERIC Educational Resources Information Center

    Marsh, C. Paul; Christenson, James A.

    This study investigates preferences of public support for allocation of expenditures toward environmental controls or toward economic growth from 1973-1975. The author considered four previously noted correlates of environmental support--education, family income, place of residence, and political orientation. Two state-wide surveys were conducted…

  11. Growth of Environmental Science at the NSLS

    SciTech Connect

    Northrup,P.; Lanzirotti, A.; Celestian, A.

    2007-01-01

    In the 25 years since the National Synchrotron Light Source (NSLS) began operations, synchrotron 'user facilities' have had a growing impact on research in molecular environmental science (MES). For example, synchrotron-based analytical techniques have allowed researchers to determine the molecular-level speciation of environmentally relevant elements and evaluate their spatial distribution and phase association at very low concentration levels (low parts per million) with micrometer or nanometer resolution [1]. For the environmental scientist, one of the primary advantages of these synchrotron-based techniques is that samples need not be disturbed or destroyed for study; characterization can often be done in-situ in dilute and heterogeneous natural samples with no need for species separation, pre-concentration, or pre-treatment [2]. Liquids, hydrated solids, and biological samples can also often be directly analyzed, which is of fundamental importance in environmental science for understanding the molecular-scale processes that occur at mineral-water interfaces and in understanding how abiotic and biotic processes are involved in the distribution, mobility and ultimate fate of molecular species in the environment.

  12. Environmental estrogens inhibit growth of rainbow trout (Oncorhynchus mykiss) by modulating the growth hormone-insulin-like growth factor system.

    PubMed

    Hanson, Andrea M; Kittilson, Jeffrey D; Martin, Lincoln E; Sheridan, Mark A

    2014-01-15

    Although environmental estrogens (EE) have been found to disrupt a wide variety of developmental and reproductive processes in vertebrates, there is a paucity of information concerning their effects on organismal growth, particularly postembryonic growth. In this study, we exposed juvenile rainbow trout (Oncorhynchus mykiss) to 17β-estradiol (E2) β-sitosterol (βS), or 4-n-nonylphenol (NP) to assess the effects of EE on overall organismal growth and on the growth hormone-insulin-like-growth factor (GH-IGF) system. EE treatment significantly reduced food conversion, body condition, and body growth. EE-inhibited growth resulted from alterations in peripheral elements of the GH-IGF system, which includes multiple GH receptors (GHRs), IGFs, and IGF receptors (IGFRs). In general, E2, βS, and NP reduced the expression of GHRs, IGFs, and IGFRs; however, the effects varied in an EE-, tissue-, element type-specific manner. For example, in liver, E2 was more efficacious than either βS, and NP in reducing GHR expression, and the effect of E2 was greater on GHR 1 than GHR2 mRNA. By contrast, in gill, all EEs affected GHR expression in a similar manner and there was no difference in the effect on GHR1 and GHR 2 mRNA. With regard to IGF expression, all EEs reduced hepatic IGF1 and IGF2 mRNA levels, whereas as in gill, only E2 and NP significantly reduced IGF1 and IGF2 expression. Lastly, E2 and NP reduced the expression of IGFR1A and IGFR1B mRNA expression similarly in gill and red and white muscle, whereas βS had no effect on expression of IGFR mRNAs. These findings indicate that EEs disrupt post-embryonic growth by reducing GH sensitivity, IGF production, and IGF sensitivity. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Nanowire growth kinetics in aberration corrected environmental transmission electron microscopy

    SciTech Connect

    Chou, Yi -Chia; Panciera, Federico; Reuter, Mark C.; Stach, Eric A.; Ross, Frances M.

    2016-03-15

    Here, we visualize atomic level dynamics during Si nanowire growth using aberration corrected environmental transmission electron microscopy, and compare with lower pressure results from ultra-high vacuum microscopy. We discuss the importance of higher pressure observations for understanding growth mechanisms and describe protocols to minimize effects of the higher pressure background gas.

  14. Nanowire growth kinetics in aberration corrected environmental transmission electron microscopy

    DOE PAGES

    Chou, Yi -Chia; Panciera, Federico; Reuter, Mark C.; ...

    2016-03-15

    Here, we visualize atomic level dynamics during Si nanowire growth using aberration corrected environmental transmission electron microscopy, and compare with lower pressure results from ultra-high vacuum microscopy. We discuss the importance of higher pressure observations for understanding growth mechanisms and describe protocols to minimize effects of the higher pressure background gas.

  15. COLLISIONAL GROWTH CONDITIONS FOR DUST AGGREGATES

    SciTech Connect

    Wada, Koji; Tanaka, Hidekazu; Suyama, Toru; Yamamoto, Tetsuo; Kimura, Hiroshi

    2009-09-10

    Collisions between dust aggregates are the key to understand the formation of planetesimals because the collision inevitably takes place in protoplanetary disks. To clarify whether or not dust aggregates can grow through their mutual collisions at relatively high velocities, we carry out more than 4000 runs of three-dimensional numerical simulations of collisions between icy equal-mass clusters formed under ballistic particle-cluster aggregation (BPCA) as well as those of ballistic cluster-cluster aggregation, including offset collisions with various values of the impact parameter. Since our BPCA clusters have a fractal dimension of 3 and a relatively compact structure, their results enable us to determine the criteria for growth and disruption of compressed aggregates at their collisions in protoplanetary disks. The results show that ice dust aggregates are able to grow at collisions with velocities up to 50 m s{sup -1}, in spite of their initial structures and impact parameters. We also find that the mass of ejecta relative to the total mass of colliding aggregates decreases with increasing the size of the aggregates. These results demonstrate the feasibility of growth and survival for dust aggregates through their mutual collisions with relatively high velocities in protoplanetary disks.

  16. Population growth, agrarian peasant economy and environmental degradation in Tanzania.

    PubMed

    Madulu, N F

    1995-03-01

    Population strategies to relieve the density pressures on land and resources in Tanzania have not considered the basic causes of population growth. Resettlement results in the same environmental degradation as in the original settlement. There should be a reduction in the population growth and planning of proper land use and resource exploitation before resettlement. Rural development must include a decline in the dependency on subsistence agriculture. Population in Tanzania increased by 213% during 1948-88. An absolute increase in population size during 1978-88 is recorded despite a slight decline in the rate of growth. Death rates declined, but birth rates were relatively stable at around 50 per 1000 population. Regions with the highest growth rates were Dar es Salaam (4.8%), Rukwa (4.3%), Arusha (3.8%), Mbeya (3.1%), and Ruvuma (3.2%). The regions with the lowest rates were Tanga and Kilimanjaro (2.1%), Coast (2.1%), Lindi (2%), and Mtwara (1.4%). Low growth rates are attributed to low fertility and high infertility. Other factors affecting high growth rates are culture, rates of natural increase, intensity of internal and international migration, climatic conditions, and availability of resources. In 1988 46% of the population was under 15 years old. Per capita land availability declined from 11.8 hectares in 1948 to 3.8 hectares in 1988. The number of landless peasants increased. Productivity declined, and distances to farms increased. The total fertility rate was 6.5 children per woman in 1988 and 6.1 during 1991-92. Slight declines were apparent in the crude birth rate also. High fertility was a response to universal marriage, low contraceptive use (7% using modern methods during 1991-92), declining lactation periods, high mortality rates, and old traditions favoring large families. Children were used extensively in time-consuming and labor-intensive activities, such as fetching water. The mean number of children ever born was higher among women with 1

  17. Eutectic growth under acoustic levitation conditions.

    PubMed

    Xie, W J; Cao, C D; Lü, Y J; Wei, B

    2002-12-01

    Samples of Pb-Sn eutectic alloy with a high density of 8.5 x 10(3) kg/m(3) are levitated with a single-axis acoustic levitator, and containerlessly melted and then solidified in argon atmosphere. High undercoolings up to 38 K are obtained, which results in a microstructural transition of "lamellas-broken lamellas-dendrites." This transition is further investigated in the light of the coupled zone for eutectic growth and the effects of ultrasound. The breaking of regular eutectic lamellas and suppression of gravity-induced macrosegregation of (Pb) and (Sn) dendrites are explained by the complicated internal flow inside the levitated drop, which is jointly induced by the shape oscillation, bulk vibration and rotation of the levitated drop. The ultrasonic field is also found to drive forced surface vibration, which subsequently excites capillary ripples and catalyzes nucleation on the sample surface.

  18. Environmental influences on speleothem growth in southwestern Oregon during the last 380, 000 years

    USGS Publications Warehouse

    Ersek, Vasile; Hostetler, Steven W.; Cheng, Hai; Clark, Peter U.; Anslow, Faron S.; Mix, Alan C.; Edwards, R. Lawrence

    2009-01-01

    The growth of carbonate formations in caves (speleothems) is sensitive to changes in environmental conditions at the surface (temperature, precipitation and vegetation) and can provide useful paleoclimatic and paleoenvironmental information. We use 73 230Th dates from speleothems collected from a cave in southwestern Oregon (USA) to constrain speleothem growth for the past 380 000 years. Most speleothem growth occurred during interglacial periods, whereas little growth occurred during glacial intervals. To evaluate potential environmental controls on speleothem growth we use two new modeling approaches: i) a one-dimensional thermal advection–diffusion model to estimate cave temperatures during the last glacial cycle, and ii) a regional climate model simulation for the Last Glacial Maximum (21 000 years before present) that assesses a range of potential controls on speleothem growth under peak glacial conditions. The two models are mutually consistent in indicating that permafrost formation did not influence speleothem growth during glacial periods. Instead, the regional climate model simulation combined with proxy data suggest that the influence of the Laurentide and Cordilleran ice sheets on atmospheric circulation induced substantial changes in water balance in the Pacific Northwest and affected speleothem growth at our location. The overall drier conditions during glacial intervals and associated periods of frozen topsoil at times of maximum surface runoff likely induced drastic changes in cave recharge and limited speleothem growth. This mechanism could have affected speleothem growth in other mid-latitude caves without requiring the presence of permafrost.

  19. Strong energy condition and complexity growth bound in holography

    NASA Astrophysics Data System (ADS)

    Yang, Run-Qiu

    2017-04-01

    This paper proves that if eternal neutral black holes satisfy some general conditions and matter fields only appear in the outside of the Killing horizon, the strong energy condition is a sufficient condition to insure that the vacuum Schwarzschild black hole has the fastest action growth of the same total energy. This result is consistent with the bound of computational complexity growth rate and gives strong evidence for the holographic complexity-action conjecture.

  20. Exploring the middle ground between environmental protection and economic growth.

    PubMed

    Kaplowitz, Michael D; Lupi, Frank; Yeboah, Felix K; Thorp, Laurie G

    2013-05-01

    Public preference concerning the environment and the economy typically has been characterized as either pro-environmental protection or pro-economic development. Researchers and policymakers increasingly suggest that environmental protection and economic growth are not mutually exclusive. However, use of dichotomous-choice policy preference questions persists. This note empirically examines an alternative response format for the typical dichotomous-choice environmental/economic policy preference question and explores respondents' stated policy preferences in light of their support for recycling. We find that most respondents do not view environmental protection and economic development policy goals to be mutually exclusive. Most respondents view economic growth and environmental protection as compatible suggesting a more heterogeneous view of the environment-economic relationship than oft reported. Hence excluding a middle response choice to the standard environment/economic policy preference question may add measurement error, increase item nonresponse, and fail to account for the views of respondents who view these goals as complementary.

  1. Mathematical modeling of growth of Salmonella in raw ground beef under isothermal conditions from 10 to 45 Degree C

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to develop primary and secondary models to describe the growth of Salmonella in raw ground beef. Primary and secondary models can be integrated into a dynamic model that can predict the microbial growth under varying environmental conditions. Growth data of Salmonel...

  2. Environmental change drives long-term recruitment and growth variation in an estuarine fish.

    PubMed

    Morrongiello, John R; Walsh, Chris T; Gray, Charles A; Stocks, Jerom R; Crook, David A

    2014-06-01

    How individuals respond to environmental change determines the strength and direction of biological processes like recruitment and growth that underpin population productivity. Ascertaining the relative importance of environmental factors can, however, be difficult given the numerous mechanisms through which they affect individuals. This is especially true in dynamic and complex estuarine environments. Here, we develop long-term otolith-based indices of recruitment and growth for estuary perch Percalates colonorum (Bemm River, Australia), to explore the importance of intrinsic (individual, demographic) and extrinsic (hydrologic, climatic, density-dependent) factors in driving estuarine fish productivity. Analyses involved a novel zero-inflated specification of catch curve regression and mixed effects modelling. The 39 years of recruitment and 46 years of growth data, spanning a period of environmental change including severe drought, displayed considerable inter-annual variation. Recruitment success was strongly related to high freshwater inflows during the spawning season, suggesting that these conditions act as spawning cues for adults and potentially provide favourable conditions for larvae. Individuals displayed age-dependent growth, with highest rates observed at younger ages in years characterized by warm temperatures, and to a lesser degree, greater magnitude base inflow conditions. We detected systematic among-year-class growth differences, but these were not attributable to year class strength, suggesting that environmental conditions experienced by individuals as juveniles can have long-lasting effects of greater importance to population productivity than density-dependent growth responses. The primacy of temperature in driving growth variation highlights that under-appreciated climatic variation can affect estuarine fish productivity through direct physiological and indirect food web mechanisms. We predict that climatic warming will promote individual

  3. Tourism in Austria: biodiversity, environmental sustainability, and growth issues.

    PubMed

    Malik, Muhammad Asad Saleem; Shah, Syed Asim; Zaman, Khalid

    2016-12-01

    This study examined the long-run and causal relationships between international tourism, biodiversity loss, environmental sustainability, and specific growth factors under the premises of sustainable tourism in Austria, by using a consistent time series data from 1975 to 2015. The results reveal that inbound tourism, per capita income, and population density affected the potential habitat area while population density largely affected the food production in a country. Inbound tourism and population density both deteriorate the environmental quality in a form of increasing carbon dioxide (CO2) emissions and fossil fuel energy consumption while per capita income reduces the fossil fuel energy consumption. Food exports increase per capita income, while food imports and population density both decrease economic growth. Inbound tourism and economic growth advance population density while forest area and food exports decrease the population density. The study supports growth-led tourism and growth-led food production in a country.

  4. Compensatory growth strategies are affected by the strength of environmental time constraints in anuran larvae.

    PubMed

    Orizaola, Germán; Dahl, Emma; Laurila, Anssi

    2014-01-01

    Organisms normally grow at a sub-maximal rate. After experiencing a period of arrested growth, individuals often show compensatory growth responses by modifying their life-history, behaviour and physiology. However, the strength of compensatory responses may vary across broad geographic scales as populations differ in their exposition to varying time constraints. We examined differences in compensatory growth strategies in common frog (Rana temporaria) populations from southern and northern Sweden. Tadpoles from four populations were reared in the laboratory and exposed to low temperature to evaluate the patterns and mechanisms of compensatory growth responses. We determined tadpoles' growth rate, food intake and growth efficiency during the compensation period. In the absence of arrested growth conditions, tadpoles from all the populations showed similar (size-corrected) growth rates, food intake and growth efficiency. After being exposed to low temperature for 1 week, only larvae from the northern populations increased growth rates by increasing both food intake and growth efficiency. These geographic differences in compensatory growth mechanisms suggest that the strategies for recovering after a period of growth deprivation may depend on the strength of time constraints faced by the populations. Due to the costs of fast growth, only populations exposed to the strong time constraints are prone to develop fast recovering strategies in order to metamorphose before conditions deteriorate. Understanding how organisms balance the cost and benefits of growth strategies may help in forecasting the impact of fluctuating environmental conditions on life-history strategies of populations likely to be exposed to increasing environmental variation in the future.

  5. Environmental noise and human prenatal growth

    SciTech Connect

    Schell, L.M.

    1981-09-01

    To determine whether chronic exposure to relatively loud noise has demonstrable biological effects in humans, a study was conducted on the effect of mother's exposure to airport noise while pregnant, and of social and biological characteristics of the family upon birthweight and gestation length. The sample of births was drawn from a community located adjacent to an international airport in the U.S., where noise levels had been measured previously. Mother's noise exposure was based upon noise levels near her residence in the community while she was pregnant. Data from 115 births were used, these being from mothers whose noise exposure history was most complete throughout the pregnancy. Using multivariate analysis to correct for family characteristics, the partial correlation coefficient for noise exposure and gestation length was negative, large, and significant in girls (r . -0.49, p less than 0.001). In boys the partial correlation coefficient was also negative but was smaller and did not quite reach statistical significance. Partial correlations with birthweight were smaller in both boys and girls and not significant. These results agree best with previous studies that suggest that noise may reduce prenatal growth. The size of the observed effects may be related to a conservative research design biased towards underestimation, as well as to the real effects of noise upon human prenatal growth.

  6. Suitable Conditions for Mycelial Growth of Phellinus spp.

    PubMed

    Hur, Hyun; Imtiaj, Ahmed; Lee, Min Woong; Lee, Tae-Soo

    2008-09-01

    The fungus Phellinus is a mushroom that is widely used medicinally. The optimal conditions for mycelial growth of 13 strains of the fungus were investigated. Mycelial growth was optimal at 25℃ and was uniformly minimal at 15℃ and 35℃. Growth was optimal at pH 6~7. The mycelial phenotype was best promoted by growth using Potato Dextrose agar, Hamada, Glucose peptone, and Yeast-Malt media, whereas Czapek Dox, Hennerberg, and Lilly media were the most unfavorable for the mycelial growth of Phellinus spp. Glucose, sucrose, fructose, and dextrin were the most suitable carbon sources for mycelial growth, while lactose, maltose, and galactose were unsuitable. Among tested nitrogen sources, ammonium phosphate, potassium nitrate, and arginine best promoted mycelial growth, while alanine, urea, and histidine least promoted mycelial growth.

  7. Suitable Conditions for Mycelial Growth of Phellinus spp.

    PubMed Central

    Hur, Hyun; Imtiaj, Ahmed; Lee, Min Woong

    2008-01-01

    The fungus Phellinus is a mushroom that is widely used medicinally. The optimal conditions for mycelial growth of 13 strains of the fungus were investigated. Mycelial growth was optimal at 25℃ and was uniformly minimal at 15℃ and 35℃. Growth was optimal at pH 6~7. The mycelial phenotype was best promoted by growth using Potato Dextrose agar, Hamada, Glucose peptone, and Yeast-Malt media, whereas Czapek Dox, Hennerberg, and Lilly media were the most unfavorable for the mycelial growth of Phellinus spp. Glucose, sucrose, fructose, and dextrin were the most suitable carbon sources for mycelial growth, while lactose, maltose, and galactose were unsuitable. Among tested nitrogen sources, ammonium phosphate, potassium nitrate, and arginine best promoted mycelial growth, while alanine, urea, and histidine least promoted mycelial growth. PMID:23997616

  8. Pan-Svalbard growth rate variability and environmental regulation in the Arctic bivalve Serripes groenlandicus

    NASA Astrophysics Data System (ADS)

    Carroll, Michael L.; Ambrose, William G.; Levin, Benjamin S.; Locke V, William L.; Henkes, Gregory A.; Hop, Haakon; Renaud, Paul E.

    2011-11-01

    Growth histories contained in the shells of bivalves provide continuous records of environmental and biological information over lifetimes spanning decades to centuries, thereby linking ecosystem responses to both natural and anthropogenic climatic variations over a range of scales. We examined growth rates and temporal growth patterns of 260 individuals of the circumpolar Greenland Smooth Cockle ( Serripes groenlandicus) collected between 1997 and 2009 from 11 sites around the Svalbard Archipelago. These sites encompass a range of oceanographic and environmental conditions, from strongly Atlantic-influenced conditions on the west coast to high-Arctic conditions in northeast Svalbard. Absolute growth was up to three times greater at the most strongly Atlantic-influenced locations compared to the most Arctic-influenced areas, and growth performance was highest at sites closest to the West Spitsbergen Current. We also developed growth chronologies up to 34 years in length extending back to 1974. Standardized growth indices (SGI) exhibited substantial inter-site variability, but there were also common temporal features including steadily increasing growth from the late 1980's to the mid-1990's followed by a marked shift from relatively greater to poorer growth in the mid-1990's and from 2004 to 2008. This pattern was consistent with phase-shifts in large-scale climatic drivers. Interannual variability in SGI was also related to local manifestations of the large-scale drivers, including sea temperature and sea ice extent. The temporal growth pattern at Rijpfjorden, on northeast Svalbard, was broadly representative (R = 0.81) of the entire dataset. While there were site-related differences in the specific relationships between growth and environmental parameters, the aggregated dataset indicated an overriding regional driver of bivalve growth: the Arctic Climate Regime Index (ACRI). These results demonstrate that sclerochronological proxies can be useful retrospective

  9. Mobility of capped silver nanoparticles under environmentally relevant conditions.

    PubMed

    Thio, Beng Joo Reginald; Montes, Milka O; Mahmoud, Mahmoud A; Lee, Dong-Woog; Zhou, Dongxu; Keller, Arturo A

    2012-07-03

    The mobility and deposition of capped silver (Ag) nanoparticles (NPs) on silica surfaces were characterized over a wide range of pH and ionic strength (IS) conditions, including seawater and freshwater. Two common organic capping agents (citrate and PVP) were evaluated. Both the capped Ag NPs and the silica surfaces were negatively charged under these environmentally relevant conditions, resulting in net repulsive electrostatics under most conditions. The steric repulsion introduced by the capping agents significantly reduced aggregation and deposition. In addition, the presence of natural organic matter in solution further decreased the deposition of either Ag NP on silica. Ag NPs were found to be highly mobile under these environmentally relevant conditions, with little or no deposition.

  10. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Environmental conditions. 50.36b Section 50.36b Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Applications for Licenses, Certifications, and Regulatory Approvals; Form; Contents; Ineligibility of Certain...

  11. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Environmental conditions. 50.36b Section 50.36b Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Applications for Licenses, Certifications, and Regulatory Approvals; Form; Contents; Ineligibility of Certain...

  12. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Environmental conditions. 50.36b Section 50.36b Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Applications for Licenses, Certifications, and Regulatory Approvals; Form; Contents; Ineligibility of Certain...

  13. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Environmental conditions. 50.36b Section 50.36b Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Applications for Licenses, Certifications, and Regulatory Approvals; Form; Contents; Ineligibility of Certain...

  14. Counseling Interactions as a Function of Spatial-Environmental Conditions.

    ERIC Educational Resources Information Center

    Lecomte, Conrad; And Others

    1981-01-01

    Investigated the effects of selected spatial-environmental conditions on counselor and counselee interview behaviors. Rated excerpts from initial sessions. Results indicated significant effects of distance on counselor concreteness, lighting on counselor communication of cognitive sets and distance on counselee affective self-disclosure in later…

  15. Matching biological traits to environmental conditions in marine benthic ecosystems

    NASA Astrophysics Data System (ADS)

    Bremner, J.; Rogers, S. I.; Frid, C. L. J.

    2006-05-01

    The effects of variability in environmental conditions on species composition in benthic ecosystems are well established, but relatively little is known about how environmental variability relates to ecosystem functioning. Benthic invertebrate assemblages are heavily involved in the maintenance of ecological processes and investigation of the biological characteristics (traits) expressed in these assemblages can provide information about some aspects of functioning. The aim of this study was to establish and explore relationships between environmental variability and biological traits expressed in megafauna assemblages in two UK regions. Patterns of trait composition were matched to environmental conditions and subsets of variables best describing these patterns determined. The nature of the relationships were subsequently examined at two separate scales, both between and within the regions studied. Over the whole area, some traits related to size, longevity, reproduction, mobility, flexibility, feeding method, sociability and living habit were negatively correlated with salinity, sea surface temperature, annual temperature range and the level of fishing effort, and positively associated with fish taxon richness and shell content of the substratum. Between the two regions, reductions in temperature range and shell content were associated with infrequent relative occurrences of short-lived, moderately mobile, flexible, solitary, opportunistic, permanent-burrow dwelling fauna and those exhibiting reproductive strategies based on benthic development. Relationships between some traits and environmental conditions diverged within the two regions, with increases in fishing effort and shell content of the substratum being associated with low frequencies of occurrence of moderately mobile and moderately to highly flexible fauna within one region, but high frequencies in the other. These changes in trait composition have implications for ecosystem processes, with, for

  16. Ceramic production during changing environmental/climatic conditions

    NASA Astrophysics Data System (ADS)

    Oestreich, Daniela B.; Glasmacher, Ulrich A.

    2015-04-01

    Ceramics, with regard to their status as largely everlasting everyday object as well as on the basis of their chronological sensitivity, reflect despite their simplicity the technological level of a culture and therefore also, directly or indirectly, the adaptability of a culture with respect to environmental and/or climatic changes. For that reason the question arises, if it is possible to identify changes in production techniques and raw material sources for ceramic production, as a response to environmental change, e.g. climate change. This paper will present results of a research about Paracas Culture (800 - 200 BC), southern Peru. Through several investigations (e.g. Schittek et al., 2014; Eitel and Mächtle, 2009) it is well known that during Paracas period changes in climate and environmental conditions take place. As a consequence, settlement patterns shifted several times through the various stages of Paracas time. Ceramics from three different sites (Jauranga, Cutamalla, Collanco) and temporal phases of the Paracas period are detailed archaeometric, geochemical and mineralogical characterized, e.g. Raman spectroscopy, XRD, and ICP-MS analyses. The aim of this research is to resolve potential differences in the chemical composition of the Paracas ceramics in space and time and to compare the data with the data sets of pre-Columbian environmental conditions. Thus influences of changing environmental conditions on human societies and their cultural conditions will be discussed. References Eitel, B. and Mächtle, B. 2009. Man and Environment in the eastern Atacama Desert (Southern Peru): Holocene climate changes and their impact on pre-Columbian cultures. In: Reindel, M. & Wagner, G. A. (eds.) New Technologies for Archaeology. Berlin Heidelberg: Springer-Verlag. Schittek, K., Mächtle, B., Schäbitz, F., Forbriger, M., Wennrich, V., Reindel, M., and Eitel, B.. Holocene environmental changes in the highlands of the southern Peruvian Andes (14° S) and their

  17. Effect of boundary conditions on thermal plume growth

    NASA Astrophysics Data System (ADS)

    Kondrashov, A.; Sboev, I.; Rybkin, K.

    2016-07-01

    We have investigated the influence of boundary conditions on the growth rate of convective plumes. Temperature and rate fields were studied in a rectangular convective cell heated by a spot heater. The results of the full-scale test were compared with the numerical data calculated using the ANSYS CFX software package. The relationship between the heat plume growth rate and heat boundary conditions, the width and height of the cell, size of heater for different kinds of liquid was established.

  18. Growth conditions determine different melatonin levels in Lupinus albus L.

    PubMed

    Arnao, Marino B; Hernández-Ruiz, Josefa

    2013-09-01

    Melatonin, an indoleamine, which has recently been assigned several roles in plant physiology as a growth promoter, as rooting agent, and as antioxidant in senescence delay and cytoprotection, seems to have a relevant function in plant stress situations. The presence of melatonin increases the resistance of lupin plant tissues (Lupinus albus L.) against natural or artificially induced adverse situations. In this work, we studied the response of lupin plants in controlled stress situations (drought-, anaerobic-, pH-, and cold stress and using ZnSO4 , NaCl, and H2 O2 as chemical stressors) and measured the changes in endogenous melatonin levels in lupin plants. Also, the effect of abscisic acid, ethylene, and natural environmental conditions were evaluated. In general, nearly all stressful factors caused an increase in melatonin in the investigated organs. The chemical stress provoked by ZnSO4 or NaCl caused the most pronounced changes in the endogenous level of melatonin, followed by cold and drought stressors. In some cases, the level of melatonin increased 12-fold with respect to the levels in control plants, indicating that melatonin biosynthesis is upregulated in common stress situations, in which it may serve as a signal molecule and/or as a direct antistress agent due to its well-known antioxidative properties.

  19. Environmental Physical Modulation of Intrinsic Tendency to Growth of Multicellular Tumour Spheroids: In Silico Experiments

    NASA Astrophysics Data System (ADS)

    Griffa, M.; Scalerandi, M.

    2005-01-01

    Lowering in nutrient local availability and rising in host mechanical rigidity are two distinct boundary conditions that affect the growth of solid a-vascular cancers in similar ways (inhibition of growth). In silico experiments based on a physical-mathematical model can shed light on some of the mechanisms at the basis of these effects and suggest that the self-organizing properties of neoplastic populations are greatly modulated by environmental restrictions.

  20. The behavior of Kevlar fibers under environmental-stress conditions

    NASA Astrophysics Data System (ADS)

    Perry, Mark Charles

    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

  1. A water use and growth model for Eucalyptus plantation in water-limited conditions

    SciTech Connect

    Calder, I.R.

    1992-12-31

    To investigate the environmental impact of plantation forestry using fast-growing tree species in southern India, a program of field studies was initiated in 1987 specifically to measure the water use, nutrient uptake and growth rates of the plantations. A water use and growth (WAG) model is proposed for calculating transpiration and growth of Eucalyptus plantation in water-limited conditions. The model is based on the measured relationships between transpiration rate and basal cross-sectional area and soil moisture availability. The volume growth rate (in water-limited conditions) is assumed to be proportional to the volume of water transpired. The model is calibrated using (deuterium tracing) measurements of transpiration and measurements of growth recorded at the Puradal experimental plantation, Karnataka, southern India.

  2. Culture Conditions Affecting the Optimal Mycelial Growth of Cystoderma amianthinum

    PubMed Central

    Shim, Sung Mi; Oh, Yun Hee; Lee, Kyung Rim; Kim, Seong Hwan; Im, Kyung Hoan; Kim, Jung Wan; Lee, U Youn; Shim, Jae Ouk; Shim, Mi Ja; Lee, Min Woong; Ro, Hyeon Su; Lee, Hyun Sook

    2005-01-01

    Cystoderma amianthinum, one of edible fungi belongs to Agaricaceae of Basidiomycota, has a good taste and flavor. This study was carried out to obtain the basic informations for the optimum mycelial growth of C. amianthinum. The optimal conditions for the mycelial growth were 25℃ and pH 5 in potato dextrose agar (PDA). C. amianthinum showed the favorable growth in the PDA and yeast malt extract agar (YMA). The favorable carbon and nitrogen sources promoting mycelial growth were fructose and histidine, respectively. The optimum C/N ratio was about 30 : 1 in case that 1% glucose was supplemented to the basal medium as a carbon source. PMID:24049476

  3. CADDIS Volume 4. Data Analysis: Predicting Environmental Conditions from Biological Observations (PECBO Appendix)

    EPA Pesticide Factsheets

    Overview of PECBO Module, using scripts to infer environmental conditions from biological observations, statistically estimating species-environment relationships, methods for inferring environmental conditions, statistical scripts in module.

  4. Metabolic network modularity in archaea depends on growth conditions.

    PubMed

    Takemoto, Kazuhiro; Borjigin, Suritalatu

    2011-01-01

    Network modularity is an important structural feature in metabolic networks. A previous study suggested that the variability in natural habitat promotes metabolic network modularity in bacteria. However, since many factors influence the structure of the metabolic network, this phenomenon might be limited and there may be other explanations for the change in metabolic network modularity. Therefore, we focus on archaea because they belong to another domain of prokaryotes and show variability in growth conditions (e.g., trophic requirement and optimal growth temperature), but not in habitats because of their specialized growth conditions (e.g., high growth temperature). The relationship between biological features and metabolic network modularity is examined in detail. We first show the absence of a relationship between network modularity and habitat variability in archaea, as archaeal habitats are more limited than bacterial habitats. Although this finding implies the need for further studies regarding the differences in network modularity, it does not contradict previous work. Further investigations reveal alternative explanations. Specifically, growth conditions, trophic requirement, and optimal growth temperature, in particular, affect metabolic network modularity. We have discussed the mechanisms for the growth condition-dependant changes in network modularity. Our findings suggest different explanations for the changes in network modularity and provide new insights into adaptation and evolution in metabolic networks, despite several limitations of data analysis.

  5. Environmental Conditions for Space Flight Hardware: A Survey

    NASA Technical Reports Server (NTRS)

    Plante, Jeannette; Lee, Brandon

    2005-01-01

    Interest in generalization of the physical environment experienced by NASA hardware from the natural Earth environment (on the launch pad), man-made environment on Earth (storage acceptance an d qualification testing), the launch environment, and the space environment, is ed to find commonality among our hardware in an effort to reduce cost and complexity. NASA is entering a period of increase in its number of planetary missions and it is important to understand how our qualification requirements will evolve with and track these new environments. Environmental conditions are described for NASA projects in several ways for the different periods of the mission life cycle. At the beginning, the mission manager defines survivability requirements based on the mission length, orbit, launch date, launch vehicle, and other factors . such as the use of reactor engines. Margins are then applied to these values (temperature extremes, vibration extremes, radiation tolerances, etc,) and a new set of conditions is generalized for design requirements. Mission assurance documents will then assign an additional margin for reliability, and a third set of values is provided for during testing. A fourth set of environmental condition values may evolve intermittently from heritage hardware that has been tested to a level beyond the actual mission requirement. These various sets of environment figures can make it quite confusing and difficult to capture common hardware environmental requirements. Environmental requirement information can be found in a wide variety of places. The most obvious is with the individual projects. We can easily get answers to questions about temperature extremes being used and radiation tolerance goals, but it is more difficult to map the answers to the process that created these requirements: for design, for qualification, and for actual environment with no margin applied. Not everyone assigned to a NASA project may have that kind of insight, as many have

  6. Biological responses to environmental heterogeneity under future ocean conditions.

    PubMed

    Boyd, Philip W; Cornwall, Christopher E; Davison, Andrew; Doney, Scott C; Fourquez, Marion; Hurd, Catriona L; Lima, Ivan D; McMinn, Andrew

    2016-08-01

    Organisms are projected to face unprecedented rates of change in future ocean conditions due to anthropogenic climate-change. At present, marine life encounters a wide range of environmental heterogeneity from natural fluctuations to mean climate change. Manipulation studies suggest that biota from more variable marine environments have more phenotypic plasticity to tolerate environmental heterogeneity. Here, we consider current strategies employed by a range of representative organisms across various habitats - from short-lived phytoplankton to long-lived corals - in response to environmental heterogeneity. We then discuss how, if and when organismal responses (acclimate/migrate/adapt) may be altered by shifts in the magnitude of the mean climate-change signal relative to that for natural fluctuations projected for coming decades. The findings from both novel climate-change modelling simulations and prior biological manipulation studies, in which natural fluctuations are superimposed on those of mean change, provide valuable insights into organismal responses to environmental heterogeneity. Manipulations reveal that different experimental outcomes are evident between climate-change treatments which include natural fluctuations vs. those which do not. Modelling simulations project that the magnitude of climate variability, along with mean climate change, will increase in coming decades, and hence environmental heterogeneity will increase, illustrating the need for more realistic biological manipulation experiments that include natural fluctuations. However, simulations also strongly suggest that the timescales over which the mean climate-change signature will become dominant, relative to natural fluctuations, will vary for individual properties, being most rapid for CO2 (~10 years from present day) to 4 decades for nutrients. We conclude that the strategies used by biota to respond to shifts in environmental heterogeneity may be complex, as they will have to

  7. Identifying ontogenetic, environmental and individual components of forest tree growth

    PubMed Central

    Chaubert-Pereira, Florence; Caraglio, Yves; Lavergne, Christian; Guédon, Yann

    2009-01-01

    Background and Aims This study aimed to identify and characterize the ontogenetic, environmental and individual components of forest tree growth. In the proposed approach, the tree growth data typically correspond to the retrospective measurement of annual shoot characteristics (e.g. length) along the trunk. Methods Dedicated statistical models (semi-Markov switching linear mixed models) were applied to data sets of Corsican pine and sessile oak. In the semi-Markov switching linear mixed models estimated from these data sets, the underlying semi-Markov chain represents both the succession of growth phases and their lengths, while the linear mixed models represent both the influence of climatic factors and the inter-individual heterogeneity within each growth phase. Key Results On the basis of these integrative statistical models, it is shown that growth phases are not only defined by average growth level but also by growth fluctuation amplitudes in response to climatic factors and inter-individual heterogeneity and that the individual tree status within the population may change between phases. Species plasticity affected the response to climatic factors while tree origin, sampling strategy and silvicultural interventions impacted inter-individual heterogeneity. Conclusions The transposition of the proposed integrative statistical modelling approach to cambial growth in relation to climatic factors and the study of the relationship between apical growth and cambial growth constitute the next steps in this research. PMID:19684021

  8. Ice Particle Growth Rates Under Upper Troposphere Conditions

    NASA Technical Reports Server (NTRS)

    Peterson, Harold; Bailey, Matthew; Hallett, John

    2010-01-01

    Atmospheric conditions for growth of ice crystals (temperature and ice supersaturation) are often not well constrained and it is necessary to simulate such conditions in the laboratory to investigate such growth under well controlled conditions over many hours. The growth of ice crystals from the vapour in both prism and basal planes was observed at temperatures of -60 C and -70 C under ice supersaturation up to 100% (200% relative humidity) at pressures derived from the standard atmosphere in a static diffusion chamber. Crystals grew outward from a vertical glass filament, thickening in the basal plane by addition of macroscopic layers greater than 2 m, leading to growth in the prism plane by passing of successive layers conveniently viewed by time lapse video.

  9. Ice Particle Growth Under Conditions of the Upper Troposphere

    NASA Technical Reports Server (NTRS)

    Peterson, Harold S.; Bailey, Matthew; Hallett, John

    2010-01-01

    Atmospheric conditions for growth of ice crystals (temperature and ice supersaturation) are often not well constrained and it is necessary to simulate such conditions in the laboratory to investigate such growth under well controlled conditions over many hours. The growth of ice crystals from the vapour in both prism and basal planes was observed at temperatures of -60 C and -70 C under ice supersaturation up to 100% (200% relative humidity) at pressures derived from the standard atmosphere in a static diffusion chamber. Crystals grew outward from a vertical glass filament, thickening in the basal plane by addition of macroscopic layers greater than 2 microns, leading to growth in the prism plane by passing of successive layers conveniently viewed by time lapse video.

  10. Ice Crystal Growth Rates Under Upper Troposphere Conditions

    NASA Technical Reports Server (NTRS)

    Peterson, Harold S.; Bailey, Matthew; Hallett, John

    2010-01-01

    Atmospheric conditions for growth of ice crystals (temperature and ice supersaturation) are often not well constrained and it is necessary to simulate such conditions in the laboratory to investigate such growth under well controlled conditions over many hours. The growth of ice crystals from the vapour in both prism and basal planes was observed at temperatures of -60 C and -70 C under ice supersaturation up to 100% (200% relative humidity) at pressures derived from the standard atmosphere in a static diffusion chamber. Crystals grew outward from a vertical glass filament, thickening in the basal plane by addition of macroscopic layers greater than 2 m, leading to growth in the prism plane by passing of successive layers conveniently viewed by time lapse video.

  11. Partitioning the Relative Importance of Phylogeny and Environmental Conditions on Phytoplankton Fatty Acids.

    PubMed

    Galloway, Aaron W E; Winder, Monika

    2015-01-01

    Essential fatty acids (EFA), which are primarily generated by phytoplankton, limit growth and reproduction in diverse heterotrophs. The biochemical composition of phytoplankton is well-known to be governed both by phylogeny and environmental conditions. Nutrients, light, salinity, and temperature all affect both phytoplankton growth and fatty acid composition. However, the relative importance of taxonomy and environment on algal fatty acid content has yet to be comparatively quantified, thus inhibiting predictions of changes to phytoplankton food quality in response to global environmental change. We compiled 1145 published marine and freshwater phytoplankton fatty acid profiles, consisting of 208 species from six major taxonomic groups, cultured in a wide range of environmental conditions, and used a multivariate distance-based linear model to quantify the total variation explained by each variable. Our results show that taxonomic group accounts for 3-4 times more variation in phytoplankton fatty acids than the most important growth condition variables. The results underscore that environmental conditions clearly affect phytoplankton fatty acid profiles, but also show that conditions account for relatively low variation compared to phylogeny. This suggests that the underlying mechanism determining basal food quality in aquatic habitats is primarily phytoplankton community composition, and allows for prediction of environmental-scale EFA dynamics based on phytoplankton community data. We used the compiled dataset to calculate seasonal dynamics of long-chain EFA (LCEFA; ≥C20 ɷ-3 and ɷ-6 polyunsaturated fatty acid) concentrations and ɷ-3:ɷ-6 EFA ratios in Lake Washington using a multi-decadal phytoplankton community time series. These analyses quantify temporal dynamics of algal-derived LCEFA and food quality in a freshwater ecosystem that has undergone large community changes as a result of shifting resource management practices, highlighting diatoms

  12. Partitioning the Relative Importance of Phylogeny and Environmental Conditions on Phytoplankton Fatty Acids

    PubMed Central

    Galloway, Aaron W. E.; Winder, Monika

    2015-01-01

    Essential fatty acids (EFA), which are primarily generated by phytoplankton, limit growth and reproduction in diverse heterotrophs. The biochemical composition of phytoplankton is well-known to be governed both by phylogeny and environmental conditions. Nutrients, light, salinity, and temperature all affect both phytoplankton growth and fatty acid composition. However, the relative importance of taxonomy and environment on algal fatty acid content has yet to be comparatively quantified, thus inhibiting predictions of changes to phytoplankton food quality in response to global environmental change. We compiled 1145 published marine and freshwater phytoplankton fatty acid profiles, consisting of 208 species from six major taxonomic groups, cultured in a wide range of environmental conditions, and used a multivariate distance-based linear model to quantify the total variation explained by each variable. Our results show that taxonomic group accounts for 3-4 times more variation in phytoplankton fatty acids than the most important growth condition variables. The results underscore that environmental conditions clearly affect phytoplankton fatty acid profiles, but also show that conditions account for relatively low variation compared to phylogeny. This suggests that the underlying mechanism determining basal food quality in aquatic habitats is primarily phytoplankton community composition, and allows for prediction of environmental-scale EFA dynamics based on phytoplankton community data. We used the compiled dataset to calculate seasonal dynamics of long-chain EFA (LCEFA; ≥C20 ɷ-3 and ɷ-6 polyunsaturated fatty acid) concentrations and ɷ-3:ɷ-6 EFA ratios in Lake Washington using a multi-decadal phytoplankton community time series. These analyses quantify temporal dynamics of algal-derived LCEFA and food quality in a freshwater ecosystem that has undergone large community changes as a result of shifting resource management practices, highlighting diatoms

  13. Particle engulfment dynamics under oscillating crystal growth conditions

    NASA Astrophysics Data System (ADS)

    Tao, Yutao; Sorgenfrei, Tina; Jauß, Thomas; Cröll, Arne; Reimann, Christian; Friedrich, Jochen; Derby, Jeffrey J.

    2017-06-01

    To better understand the physical mechanisms behind particle engulfment dynamics under fluctuating solidification velocities, transient simulations are performed for a SiC particle in a silicon solidification system with oscillating growth rates using a rigorous finite-element model developed previously. Simulations reveal complicated behaviors that require a re-examination of the classical notion of a steady-state, critical growth velocity, vc, for particle engulfment. Under sinusoidal growth variations at a frequency representative of turbulent fluctuations in a large-scale melt, stable pushing states featuring nonlinear particle-growth front oscillations can arise, even when the maximum growth velocity slightly exceeds vc. However, higher-amplitude growth oscillations at the same frequency are shown to result in particle engulfment. Significantly, engulfment under such dynamic conditions can occur at average solidification rates far below the steady-state critical velocity, a behavior consistent with many experimental observations.

  14. An American Laboratory: Population Growth and Environmental Quality in California.

    ERIC Educational Resources Information Center

    McConnell, Robert

    1993-01-01

    Describes the cumulative impact of rapid population growth, industrial and military activity, agriculture, and motor vehicles on California's environmental and social fabric. Discusses these problems in California as a forecast for the nation and test to consensus-based U.S. representative government. (Author/ MCO)

  15. Bacillus spp. from rainforest soil promote plant growth under limited nitrogen conditions.

    PubMed

    Huang, X-F; Zhou, D; Guo, J; Manter, D K; Reardon, K F; Vivanco, J M

    2015-03-01

    The aim of this study was to evaluate effects of PGPR (plant growth-promoting rhizobacteria) isolated from rainforest soil on different plants under limited nitrogen conditions. Bacterial isolates from a Peruvian rainforest soil were screened for plant growth-promoting effects on Arabidopsis (Col-0). Four selected isolates including one Bacillus subtilis, two B. atrophaeus and one B. pumilus significantly promoted growth of Zea mays L. and Solanum lycopersicum under greenhouse conditions. Moreover, the PGPRs significantly promoted growth of S. lycopersicum in both low and nitrogen-amended soil conditions. These PGPR strains were further studied to obtain insights into possible mechanisms of plant growth promotion. Volatile chemicals from those isolates promoted Arabidopsis growth, and the expression of genes related to IAA production was induced in the Arabidopsis plants treated with PGPRs. Further, selected PGPR strains triggered induced systemic resistance (ISR) against Pseudomonas syringae pv tomato DC3000 in Arabidopsis. PGPR strains isolated from the rainforest soil promoted the plant growth of Arabidopsis, corn and tomato. New PGPR that have wider adaptability to different crops, soils and environmental conditions are needed to decrease our reliance on agricultural amendments derived from fossil-based fuels. The PGPRs isolated from a nonagricultural site constitute new plant growth-promoting strains that could be developed for agricultural uses. © 2014 The Society for Applied Microbiology.

  16. Indium antimonide crystal growth experiment M562. [Skylab weightless conditions

    NASA Technical Reports Server (NTRS)

    Gatos, H. C.; Witt, A. F.

    1974-01-01

    It was established that ideal diffusion controlled steady state conditions, never accomplished on earth, were achieved during the growth of Te-doped InSb crystals in Skylab. Surface tension effects led to nonwetting conditions under which free surface solidification took place in confined geometry. It was further found that, under forced contact conditions, surface tension effects led to the formation of surface ridges (not previously observed on earth) which isolated the growth system from its container. In addition, it was possible, for the first time, to identify unambiguously: the origin of segregation discontinuities associated with facet growth, the mode of nucleation and propagation of rotational twin boundaries, and the specific effect of mechanical-shock perturbations on segregation. The results obtained prove the advantageous conditions provided by outer space. Thus, fundamental data on solidification thought to be unattainable because of gravity-induced interference on earth are now within reach.

  17. Growth rate changes of sodium chlorate crystals independent of growth conditions

    NASA Astrophysics Data System (ADS)

    Mitrović, M. M.; Žekić, A. A.; Baroš, Z. Z.

    2008-10-01

    Results of investigations of the growth rate changes inherent to the crystal are presented. It is shown that, in initial growth stage, there exist crystal growth rate changes independent of experimental conditions, with tendency to level during the time. Time evolution of sodium chlorate crystals growth rate dispersion is also presented. The results obtained show that these changes must be included in the interpretations of the growth rate changes affected by various parameters (supersaturation, temperature, fields, stress, impurities, etc.), which have not previously been taken into account. These results may improve the current crystal growth theories.

  18. Comparing Environmental Conditions Using Indicators of Pollution Hazard

    PubMed

    Turner; Ruffio; Roberts

    1997-07-01

    / Land use/land cover classifications for 1973 and 1991, derived from the interpretation of satellite imagery, are quantified on the basis of biophysical land units in a study area in southeastern Australia. Nutrient export potentials are estimated for each land unit based on their composition of land use/land cover classes. Spatial and temporal comparisons are made of the land units based on the calculated pollution hazard indicators to provide an insight into changes in the state of the environment and the regional significance of land use changes. For example, one ecosystem, unique to the study, showed a large increase in pollution hazard over the study period as a manifestation of an 11-fold rise in cleared area and an expansion of cropping activities. The benefits to environmental management in general are discussed.KEY WORDS: Land cover change; Nutrient export; Environmental condition; Pollution hazard; Agricultural pollution; Nonpoint source pollution; Diffuse pollution; Environmental degradation

  19. Maternal effects provide phenotypic adaptation to local environmental conditions.

    PubMed

    Galloway, Laura F

    2005-04-01

    In outcrossing plants, seed dispersal distance is often less than pollen movement. If the scale of environmental heterogeneity within a population is greater than typical seed dispersal distances but less than pollen movement, an individual's environment will be similar to that of its mother but not necessarily its father. Under these conditions, environmental maternal effects may evolve as a source of adaptive plasticity between generations, enhancing offspring fitness in the environment that they are likely to experience. This idea is illustrated using Campanula americana, an herb that grows in understory and light-gap habitats. Estimates of seed dispersal suggest that offspring typically experience the same light environment as their mother. In a field experiment testing the effect of open vs understory maternal light environments, maternal light directly influenced offspring germination rate and season, and indirectly affected germination season by altering maternal flowering time. Results to date indicate that these maternal effects are adaptive; further experimental tests are ongoing. Evaluating maternal environmental effects in an ecological context demonstrates that they may provide phenotypic adaptation to local environmental conditions. Copyright New Phytologist (2005).

  20. Growth and development and their environmental and biological determinants.

    PubMed

    da Rocha Neves, Kelly; de Souza Morais, Rosane Luzia; Teixeira, Romero Alves; Pinto, Priscilla Avelino Ferreira

    2016-01-01

    To investigate child growth, cognitive/language development, and their environmental and biological determinants. This was a cross-sectional, predictive correlation study with all 92 children aged 24-36 months who attended the municipal early childhood education network in a town in the Vale do Jequitinhonha region, in 2011. The socioeconomic profile was determined using the questionnaire of the Associação Brasileira de Empresas de Pesquisa. The socio-demographicand maternal and child health profiles were created through a self-prepared questionnaire. The height-for-age indicator was selected to represent growth. Cognitive/language development was assessed through the Bayley Scale of Infant and Toddler Development. The quality of educational environments was assessed by Infant/Toddler Environment Scale; the home environment was assessed by the Home Observation for Measurement of the Environment. The neighborhood quality was determined by a self-prepared questionnaire. A multivariate linear regression analysis was performed. Families were predominantly from socioeconomic class D, with low parental education. The prevalence of stunted growth was 14.1%; cognitive and language development were below average at 28.6% and 28.3%, respectively. Educational institutions were classified as inadequate, and 69.6% of homes were classified as presenting a risk for development. Factors such as access to parks and pharmacies and perceived security received the worst score regarding neighborhood environment. Biological variables showed a greater association with growth and environmental variables with development. The results showed a high prevalence of stunting and below-average results for cognitive/language development among the participating children. Both environmental and biological factors were related to growth and development. However, biological variables showed a greater association with growth, whereas environmental variables were associated with development

  1. Evaluation of Cronobacter Growth and Phenotypic Variation Under Modified Culture Conditions.

    PubMed

    Segars, Katharine; Simpson, Steven; Kerdahi, Khalil; Sulaiman, Irshad M

    2016-02-01

    Cronobacter sakazakii is an opportunistic pathogen known to cause acute meningitis and necrotizing enterocolitis in neonates and immunocompromised individuals. It has been isolated from a wide range of food and environmental samples, and has been linked to outbreaks associated with powdered infant formula. This study was carried out to assess variations in growth conditions (temperature, pH, and sugar supplement) and to establish how these changes impact phenotypic characteristics for successful recovery and identification of Cronobacter, particularly for routine surveillance purposes. A total of six Cronobacter isolates were tested to evaluate the above growth conditions, including three ATCC Cronobacter reference and three environmental isolates obtained from regulatory sample screening. Although only slight changes in colony-forming units were observed across the pH range and the sugars tested, the morphology was significantly impacted by changes in these growth factors. Incubation between 30 and 50 °C resulted in growth after 24 h, and the growth was slower at ambient temperature and colony formation was most robust at 30 °C. Results of this study suggest that 30 °C may be suitable for recovery of some Cronobacter strains, and minor variations in growth conditions can alter colony morphology and appearance. Expression of unique biological characteristics based on phenotypic observations may be beneficial for differentiating various Cronobacter strains.

  2. Can environmental conditions experienced in early life influence future generations?

    PubMed Central

    Burton, Tim; Metcalfe, Neil B.

    2014-01-01

    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

  3. [Influence endophytic bacteria to promote plants growth in stress conditions].

    PubMed

    Napora, Anna; Kacprzak, Małgorzata; Nowak, Kamil; Grobelak, Anna

    2015-01-01

    The growth of plants under stress conditions is often assisted by microorganisms colonizing the rhizosphere (the root zone of the highest microbial activity). One of the most important bacterial groups to encourage the growth of plants (PGPB) are endophytes. These microorganisms penetrate living cells of plants and there they lead the microbiological activity as endosymbionts. These microorganisms can effectively promote the growth of plants under stress conditions and stimulate biochemical activities: nitrogen fixation, production of growth hormones (auxins, cytokinins and gibberellins), reduction of the high concentration of ethylene as well as facilitation of the collection plant minerals and water. This paper is an attempt to summarize the current state of knowledge about the biochemical activity of bacterial endophytes.

  4. Experiment 8: Environmental Conditions in the ASTROCULTURE(trademark) Plant Chamber During the USML-2 Mission

    NASA Technical Reports Server (NTRS)

    Bula, R. J.; Zhou, Weijia; Yetka, R. A.; Draeger, N. A.

    1998-01-01

    Conducting plant research to assess the impact of microgravity on plant growth and development requires a plant chamber that has the capability to control other environmental parameters involved in plant growth and development. The environmental control in a space-based plant chamber must be equivalent to that available in such facilities used for terrestrial plant research. Additionally, plants are very sensitive to a number of atmospheric gaseous materials. Thus, the atmosphere of a plant chamber must be isolated from the space vehicle atmosphere, and the plant growth unit should have the capability to remove any such deleterious materials that may impact plant growth and development. The Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison, has developed a totally enclosed controlled environment plant growth unit. The flight unit was used to support the ASTROCULTURE(TM) experiment conducted during the USML-2 mission. The experiment had two major objectives: 1) Provide further validation of the flight unit to control the experiment-defined environmental parameters in the plant chamber, and 2) support a plant experiment to assess the capability of potato plant material to produce tubers in microgravity. This paper describes the temperature, humidity, and carbon dioxide conditions of the plant chamber during the mission, from launch to landing. Another paper will present the plant response data.

  5. Experiment 8: Environmental Conditions in the ASTROCULTURE(trademark) Plant Chamber During the USML-2 Mission

    NASA Technical Reports Server (NTRS)

    Bula, R. J.; Zhou, Weijia; Yetka, R. A.; Draeger, N. A.

    1998-01-01

    Conducting plant research to assess the impact of microgravity on plant growth and development requires a plant chamber that has the capability to control other environmental parameters involved in plant growth and development. The environmental control in a space-based plant chamber must be equivalent to that available in such facilities used for terrestrial plant research. Additionally, plants are very sensitive to a number of atmospheric gaseous materials. Thus, the atmosphere of a plant chamber must be isolated from the space vehicle atmosphere, and the plant growth unit should have the capability to remove any such deleterious materials that may impact plant growth and development. The Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison, has developed a totally enclosed controlled environment plant growth unit. The flight unit was used to support the ASTROCULTURE(TM) experiment conducted during the USML-2 mission. The experiment had two major objectives: 1) Provide further validation of the flight unit to control the experiment-defined environmental parameters in the plant chamber, and 2) support a plant experiment to assess the capability of potato plant material to produce tubers in microgravity. This paper describes the temperature, humidity, and carbon dioxide conditions of the plant chamber during the mission, from launch to landing. Another paper will present the plant response data.

  6. In situ study of single-walled carbon nanotube growth in an environmental scanning electron microscope.

    PubMed

    Mehedi, H-A; Ravaux, J; Tahir, S; Podor, R; Jourdain, V

    2016-12-16

    Monitoring individual single-walled carbon nanotubes (SWCNTs) during their growth is a highly sought-after goal in view of understanding the processes involved in the nucleation, elongation and termination which ultimately control the diameter and chiral selectivity. Here, we report on the first truly in situ observations of SWCNT growth in an environmental scanning electron microscope (ESEM). The CNT growth from lithographically patterned catalysts was investigated as a function of the catalyst type (Fe, Co or Ni), temperature, type of precursor (ethanol or acetylene), gas phase composition and pressure, and pretreatment conditions, and we report on the most appropriate conditions for SWCNT growth in ESEM conditions. We show that this approach allows the observation at the submicron scale of the different steps of the nanotube synthesis including the catalyst reduction, the growth and percolation of the nanotube network, and the deposition of individual nanotubes grown in the gas phase on the substrate. Despite these obvious advantages, we identified a few limitations which will need to be tackled for fully taking advantage of the approach, for instance for monitoring the growth of individual SWCNTs by ESEM, including the short lifetime of the catalyst nanoparticles, the preference for kite growth (by opposition to surface growth) and the influence of the electron beam on the nanotube growth.

  7. In situ study of single-walled carbon nanotube growth in an environmental scanning electron microscope

    NASA Astrophysics Data System (ADS)

    Mehedi, H.-A.; Ravaux, J.; Tahir, S.; Podor, R.; Jourdain, V.

    2016-12-01

    Monitoring individual single-walled carbon nanotubes (SWCNTs) during their growth is a highly sought-after goal in view of understanding the processes involved in the nucleation, elongation and termination which ultimately control the diameter and chiral selectivity. Here, we report on the first truly in situ observations of SWCNT growth in an environmental scanning electron microscope (ESEM). The CNT growth from lithographically patterned catalysts was investigated as a function of the catalyst type (Fe, Co or Ni), temperature, type of precursor (ethanol or acetylene), gas phase composition and pressure, and pretreatment conditions, and we report on the most appropriate conditions for SWCNT growth in ESEM conditions. We show that this approach allows the observation at the submicron scale of the different steps of the nanotube synthesis including the catalyst reduction, the growth and percolation of the nanotube network, and the deposition of individual nanotubes grown in the gas phase on the substrate. Despite these obvious advantages, we identified a few limitations which will need to be tackled for fully taking advantage of the approach, for instance for monitoring the growth of individual SWCNTs by ESEM, including the short lifetime of the catalyst nanoparticles, the preference for kite growth (by opposition to surface growth) and the influence of the electron beam on the nanotube growth.

  8. Lifetime growth in wild meerkats: incorporating life history and environmental factors into a standard growth model.

    PubMed

    English, Sinéad; Bateman, Andrew W; Clutton-Brock, Tim H

    2012-05-01

    Lifetime records of changes in individual size or mass in wild animals are scarce and, as such, few studies have attempted to model variation in these traits across the lifespan or to assess the factors that affect them. However, quantifying lifetime growth is essential for understanding trade-offs between growth and other life history parameters, such as reproductive performance or survival. Here, we used model selection based on information theory to measure changes in body mass over the lifespan of wild meerkats, and compared the relative fits of several standard growth models (monomolecular, von Bertalanffy, Gompertz, logistic and Richards). We found that meerkats exhibit monomolecular growth, with the best model incorporating separate growth rates before and after nutritional independence, as well as effects of season and total rainfall in the previous nine months. Our study demonstrates how simple growth curves may be improved by considering life history and environmental factors, which may be particularly relevant when quantifying growth patterns in wild populations.

  9. Toward more robust projections of forest landscape dynamics under novel environmental conditions: embedding PnET within LANDIS-II

    Treesearch

    A. De Bruijn; E.J. Gustafson; B.R. Sturtevant; J.R. Foster; B.R. Miranda; N.I. Lichti; D.F. Jacobs

    2014-01-01

    Ecological models built on phenomenological relationships and behavior of the past may not be robustunder novel conditions of the future because global changes are producing environmental conditions that forests have not experienced historically. We developed a new succession extension for the LANDIS-II forest landscape model, PnET-Succession, to simulate forest growth...

  10. Environmental water demand assessment under climate change conditions.

    PubMed

    Sarzaeim, Parisa; Bozorg-Haddad, Omid; Fallah-Mehdipour, Elahe; Loáiciga, Hugo A

    2017-07-01

    Measures taken to cope with the possible effects of climate change on water resources management are key for the successful adaptation to such change. This work assesses the environmental water demand of the Karkheh river in the reach comprising Karkheh dam to the Hoor-al-Azim wetland, Iran, under climate change during the period 2010-2059. The assessment of the environmental demand applies (1) representative concentration pathways (RCPs) and (2) downscaling methods. The first phase of this work projects temperature and rainfall in the period 2010-2059 under three RCPs and with two downscaling methods. Thus, six climatic scenarios are generated. The results showed that temperature and rainfall average would increase in the range of 1.7-5.2 and 1.9-9.2%, respectively. Subsequently, flows corresponding to the six different climatic scenarios are simulated with the unit hydrographs and component flows from rainfall, evaporation, and stream flow data (IHACRES) rainfall-runoff model and are input to the Karkheh reservoir. The simulation results indicated increases of 0.9-7.7% in the average flow under the six simulation scenarios during the period of analysis. The second phase of this paper's methodology determines the monthly minimum environmental water demands of the Karkheh river associated with the six simulation scenarios using a hydrological method. The determined environmental demands are compared with historical ones. The results show that the temporal variation of monthly environmental demand would change under climate change conditions. Furthermore, some climatic scenarios project environmental water demand larger than and some of them project less than the baseline one.

  11. Plankton bioindicators of environmental conditions in coastal lagoons

    NASA Astrophysics Data System (ADS)

    Hemraj, Deevesh A.; Hossain, Md A.; Ye, Qifeng; Qin, Jian G.; Leterme, Sophie C.

    2017-01-01

    Coastal lagoons are characterised by strong spatial gradient of environmental parameters, especially hypersalinity, and are prone to anthropogenic disturbance. The Coorong (South Australia) is an inverse estuarine coastal lagoon separated from the sea by sand dunes. It is exposed to extreme water quality changes that affect its aquatic communities. Here, we used plankton as indicators of extreme environmental fluctuations to monitor and manage the environmental health of such complex systems. We defined the relationship of different plankton communities with water quality fluctuations and determined plankton species suitable for monitoring the ecosystem health. Two distinct communities of phytoplankton and zooplankton were identified, with salinity and nutrients being the principal factors impacting species distribution. Thus, two sets of indicator species were selected based on the different communities observed. Polychaete and gastropod larvae were positive indicators, showing salinity range restriction of brackish to marine. The distribution Acartia cf. fancetti represented healthy hypersaline conditions (salinity 40-60), while Cyclophora sp. and Scrippsiella sp. were negative indicators, correlating with extreme salinity and ammonia levels. The implementation of planktonic organisms as environmental indicators provided a constructive tool for the management of ecosystem health of the Coorong and will be applicable to similar coastal lagoons.

  12. The effect and role of environmental conditions on magnetosome synthesis

    PubMed Central

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

    2014-01-01

    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

  13. The apparatus "Photostat-I" for simulating Martian environmental conditions.

    PubMed

    Zaar, E I; Zelikson, V G; Kitaigorodsky, M G; Lozina-Lozinsky, L K; Koshelev, G V; Rybin, M A

    1970-01-01

    One of the main tasks of exobiology is to determine conditions required for life on different planets of our solar system. At present, experimental ecological methods permitting the study of responses of living systems to extreme influences and, in particular, to simulated environmental Martian conditions, are widely used. To study the reaction of Earth organisms, special chambers and mechanisms are used which allow the modelling of conditions different from ours, mainly Martian. Existing devices capable of simulating the Martian environment. Our apparatus "Photostat-I" permits the simulation of pressure and visible light illumination (up to 60,000 lux), the irradiation of biological objectives in UV light (220-400 nm) and the production of a daily temperature cycle typical of Mars with a high degree of accuracy.

  14. Growth Factor Liberation and DPSC Response Following Dentine Conditioning.

    PubMed

    Sadaghiani, L; Gleeson, H B; Youde, S; Waddington, R J; Lynch, C D; Sloan, A J

    2016-10-01

    Liberation of the sequestrated bioactive molecules from dentine by the action of applied dental materials has been proposed as an important mechanism in inducing a dentinogenic response in teeth with viable pulps. Although adhesive restorations and dentine-bonding procedures are routinely practiced, clinical protocols to improve pulp protection and dentine regeneration are not currently driven by biological knowledge. This study investigated the effect of dentine (powder and slice) conditioning by etchants/conditioners relevant to adhesive restorative systems on growth factor solubilization and odontoblast-like cell differentiation of human dental pulp progenitor cells (DPSCs). The agents included ethylenediaminetetraacetic acid (EDTA; 10%, pH 7.2), phosphoric acid (37%, pH <1), citric acid (10%, pH 1.5), and polyacrylic acid (25%, pH 3.9). Growth factors were detected in dentine matrix extracts drawn by EDTA, phosphoric acid, and citric acid from powdered dentine. The dentine matrix extracts were shown to be bioactive, capable of stimulating odontogenic/osteogenic differentiation as observed by gene expression and phenotypic changes in DPSCs cultured in monolayer on plastic. Polyacrylic acid failed to solubilize proteins from powdered dentine and was therefore considered ineffective in triggering a growth factor-mediated response in cells. The study went on to investigate the effect of conditioning dentine slices on growth factor liberation and DPSC behavior. Conditioning by EDTA, phosphoric acid, and citric acid exposed growth factors on dentine and triggered an upregulation in genes associated with mineralized differentiation, osteopontin, and alkaline phosphatase in DPSCs cultured on dentine. The cells demonstrated odontoblast-like appearances with elongated bodies and long extracellular processes extending on dentine surface. However, phosphoric acid-treated dentine appeared strikingly less populated with cells, suggesting a detrimental impact on cell

  15. Environmental conditions and transcriptional regulation in Escherichia coli: a physiological integrative approach.

    PubMed

    Martínez-Antonio, Agustino; Salgado, Heladia; Gama-Castro, Socorro; Gutiérrez-Ríos, Rosa María; Jiménez-Jacinto, Verónica; Collado-Vides, Julio

    2003-12-30

    Bacteria develop a number of devices for sensing, responding, and adapting to different environmental conditions. Understanding within a genomic perspective how the transcriptional machinery of bacteria is modulated, as a response for changing conditions, is a major challenge for biologists. Knowledge of which genes are turned on or turned off under specific conditions is essential for our understanding of cell behavior. In this study we describe how the information pertaining to gene expression and associated growth conditions (even with very little knowledge of the associated regulatory mechanisms) is gathered from the literature and incorporated into RegulonDB, a database on transcriptional regulation and operon organization in E. coli. The link between growth conditions, signal transduction, and transcriptional regulation is modeled in the database in a simple format that highlights biological relevant information. As far as we know, there is no other database that explicitly clarifies the effect of environmental conditions on gene transcription. We discuss how this knowledge constitutes a benchmark that will impact future research aimed at integration of regulatory responses in the cell; for instance, analysis of microarrays, predicting culture behavior in biotechnological processes, and comprehension of dynamics of regulatory networks. This integrated knowledge will contribute to the future goal of modeling the behavior of E. coli as an entire cell. The RegulonDB database can be accessed on the web at the URL: http://www.cifn.unam.mx/Computational_Biology/regulondb/. Copyright 2003 Wiley Periodicals, Inc.

  16. Biomass allocation along tree stems in relation to environmental conditions

    NASA Astrophysics Data System (ADS)

    Merganicova, Katarina; Merganic, Jan; Sitkova, Zuzana; Sitko, Roman; Lestianska, Adriana; Strelcova, Katarina; Jezik, Marek

    2017-04-01

    Traditional tree parameters measured by foresters are tree diameter at breast height and tree height. Allocation of biomass to other parts of trees is usually estimated using empirically derived relationships. These are considered to be constant over time. However, current changing climatic conditions and climate extremes may cause changes in allocation, which has already been indicated in some studies of herbs and tree seedlings. Nevertheless, the data from mature trees are still rare. Our study aims to fill the gap in this area by analysing biomass allocation along tree stems over a period of several years. The analysed data represent the radial growth of beech trees at four different heights along their main stem axes. The values of radial growth were derived from the continual measurements of stem diameters at different stem heights with band dendrometers during the period from 2014 to 2016. The years differed in their weather conditions, which allowed us to analyse the impact of climatic conditions on the biomass allocation along tree stems. The results of this study can enlighten how the biomass allocation in mature trees responds to the changes in climatic conditions and to drought, which is one of the most threatening climate extremes of Central European forests.

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

    PubMed

    Misyura, Maksym; Colasanti, Joseph; Rothstein, Steven J

    2013-01-01

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

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

    PubMed Central

    Rothstein, Steven J.

    2013-01-01

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

  19. Overview of environmental and hydrogeologic conditions at Dillingham, Alaska

    USGS Publications Warehouse

    Palcsak, Betty B.; Dorava, Joseph M.

    1994-01-01

    The remote city of Dillingham is at the northern end of Bristol Bay in southwestern Alaska. The hydrology of the area is strongly affected by the mild maritime climate and local geologic conditions. Dillingham residents obtain drinking water from both deep and shallow aquifers composed of gravels and sands and separated by layers of clay underlying the community. Alternative sources of drinking water are limited to the development of new wells because surface-water sources are of inadequate quantity or quality or are located at too great a distance from the population. The Federal Aviation Administration owns or operates airway support facilities in Dillingham and wishes to consider the severity of contamination and the current environmental setting when they evaluate options for compliance with environmental regulations at their facilities. This report describes the climate. vegetation, geology, soils, ground-water and surface-water hydrology, and flood potential of the areas surrounding the Federal Aviation Administration facilities near Dillingham.

  20. Using a Novel Wireless-Networked Decentralized Control Scheme under Unpredictable Environmental Conditions

    PubMed Central

    Chang, Chung-Liang; Huang, Yi-Ming; Hong, Guo-Fong

    2015-01-01

    The direction of sunshine or the installation sites of environmental control facilities in the greenhouse result in different temperature and humidity levels in the various zones of the greenhouse, and thus, the production quality of crop is inconsistent. This study proposed a wireless-networked decentralized fuzzy control scheme to regulate the environmental parameters of various culture zones within a greenhouse. The proposed scheme can create different environmental conditions for cultivating different crops in various zones and achieve diversification or standardization of crop production. A star-type wireless sensor network is utilized to communicate with each sensing node, actuator node, and control node in various zones within the greenhouse. The fuzzy rule-based inference system is used to regulate the environmental parameters for temperature and humidity based on real-time data of plant growth response provided by a growth stage selector. The growth stage selector defines the control ranges of temperature and humidity of the various culture zones according to the leaf area of the plant, the number of leaves, and the cumulative amount of light. The experimental results show that the proposed scheme is stable and robust and provides basis for future greenhouse applications. PMID:26569264

  1. Stability of melt crystal growth under microgravity conditions

    NASA Astrophysics Data System (ADS)

    Tatarchenko, V. A.

    The conception of dynamic stability of melt crystal growth has been developed. The method based on the Lyapunov stability theory has been used to the study stability of crystallization by capillary shaping techniques including Czokhralsky, Stepanov, Kiropoulos, Verneuil and floating zone methods. Preliminary results of the stability analysis of crystallization by floating zone technique under microgravity conditions are presented here.

  2. Investigation of the Best Saccharomyces cerevisiae Growth Condition.

    PubMed

    Salari, Roshanak; Salari, Rosita

    2017-01-01

    Saccharomyces cerevisiae is known as one of the useful yeasts which are utilized in baking and other industries. It can be easily cultured at an economic price. Today the introduction of safe and efficient carriers is being considered. Due to its generally round shape, and the volume that is enclosed by its membrane and cell wall, it is used to encapsulate active materials to protect them from degradation or to introduce a sustained release drug delivery system. Providing the best conditions in order to achieve the best morphological properties of Saccharomyces cerevisiae as a carrier. In this research, the most suitable growth condition of yeast cells which provides the best size for use as drug carriers was found by a bioreactor in a synthetic culture medium. Yeast cell reproduction and growth curves were obtained, based on pour plate colony counting data and UV/Visible sample absorption at 600 nm. Yeast cell growth patterns and growth rates were determined by Matlab mathematical software. Results showed that pH=4 and dissolving oxygen (DO) 5% was the best condition for yeast cells to grow and reproduce. This condition also provided the largest size (2 × 3 μ) yeast cells. Owing to the yeast cells' low-cost production and their structural characteristics, they could be used as potent drug carriers. This work was supported by a grant from the Vice Chancellor of Research of Mashhad University of Medical Sciences.

  3. Investigation of the Best Saccharomyces cerevisiae Growth Condition

    PubMed Central

    Salari, Roshanak; Salari, Rosita

    2017-01-01

    Introduction Saccharomyces cerevisiae is known as one of the useful yeasts which are utilized in baking and other industries. It can be easily cultured at an economic price. Today the introduction of safe and efficient carriers is being considered. Due to its generally round shape, and the volume that is enclosed by its membrane and cell wall, it is used to encapsulate active materials to protect them from degradation or to introduce a sustained release drug delivery system. Providing the best conditions in order to achieve the best morphological properties of Saccharomyces cerevisiae as a carrier. Methods In this research, the most suitable growth condition of yeast cells which provides the best size for use as drug carriers was found by a bioreactor in a synthetic culture medium. Yeast cell reproduction and growth curves were obtained, based on pour plate colony counting data and UV/Visible sample absorption at 600 nm. Yeast cell growth patterns and growth rates were determined by Matlab mathematical software. Results Results showed that pH=4 and dissolving oxygen (DO) 5% was the best condition for yeast cells to grow and reproduce. This condition also provided the largest size (2 × 3 μ) yeast cells. Conclusion Owing to the yeast cells’ low-cost production and their structural characteristics, they could be used as potent drug carriers. Funding This work was supported by a grant from the Vice Chancellor of Research of Mashhad University of Medical Sciences. PMID:28243411

  4. Assessing environmental conditions of Antarctic footpaths to support management decisions.

    PubMed

    Tejedo, Pablo; Benayas, Javier; Cajiao, Daniela; Albertos, Belén; Lara, Francisco; Pertierra, Luis R; Andrés-Abellán, Manuela; Wic, Consuelo; Luciáñez, Maria José; Enríquez, Natalia; Justel, Ana; Reck, Günther K

    2016-07-15

    Thousands of tourists visit certain Antarctic sites each year, generating a wide variety of environmental impacts. Scientific knowledge of human activities and their impacts can help in the effective design of management measures and impact mitigation. We present a case study from Barrientos Island in which a management measure was originally put in place with the goal of minimizing environmental impacts but resulted in new undesired impacts. Two alternative footpaths used by tourist groups were compared. Both affected extensive moss carpets that cover the middle part of the island and that are very vulnerable to trampling. The first path has been used by tourists and scientists since over a decade and is a marked route that is clearly visible. The second one was created more recently. Several physical and biological indicators were measured in order to assess the environmental conditions for both paths. Some physical variables related to human impact were lower for the first path (e.g. soil penetration resistance and secondary treads), while other biochemical and microbiological variables were higher for the second path (e.g. β-glucosidase and phosphatase activities, soil respiration). Moss communities located along the new path were also more diverse and sensitive to trampling. Soil biota (Collembola) was also more abundant and richer. These data indicate that the decision to adopt the second path did not lead to the reduction of environmental impacts as this path runs over a more vulnerable area with more outstanding biological features (e.g. microbiota activity, flora and soil fauna diversity). In addition, the adoption of a new route effectively doubles the human footprint on the island. We propose using only the original path that is less vulnerable to the impacts of trampling. Finally from this process, we identify several key issues that may be taken into account when carrying out impact assessment and environmental management decision-making in the

  5. Environmental control of carbon allocation matters for modelling forest growth.

    PubMed

    Guillemot, Joannès; Francois, Christophe; Hmimina, Gabriel; Dufrêne, Eric; Martin-StPaul, Nicolas K; Soudani, Kamel; Marie, Guillaume; Ourcival, Jean-Marc; Delpierre, Nicolas

    2017-04-01

    We aimed to evaluate the importance of modulations of within-tree carbon (C) allocation by water and low-temperature stress for the prediction of annual forest growth with a process-based model. A new C allocation scheme was implemented in the CASTANEA model that accounts for lagged and direct environmental controls of C allocation. Different approaches (static vs dynamic) to modelling C allocation were then compared in a model-data fusion procedure, using satellite-derived leaf production estimates and biometric measurements at c. 10(4) sites. The modelling of the environmental control of C allocation significantly improved the ability of CASTANEA to predict the spatial and year-to-year variability of aboveground forest growth along regional gradients. A significant effect of the previous year's water stress on the C allocation to leaves and wood was reported. Our results also are consistent with a prominent role of the environmental modulation of sink demand in the wood growth of the studied species. Data available at large scales can inform forest models about the processes driving annual and seasonal C allocation. Our results call for a greater consideration of C allocation drivers, especially sink-demand fluctuations, for the simulations of current and future forest productivity with process-based models.

  6. EFFECT OF CATALASE AND CULTURAL CONDITIONS ON GROWTH OF BEGGIATOA.

    PubMed

    BURTON, S D; MORITA, R Y

    1964-12-01

    Burton, Sheril D. (Oregon State University, Corvallis), and Richard Y. Morita. Effect of catalase and cultural conditions on growth of Beggiatoa. J. Bacteriol. 88:1755-1761. 1964.-The addition of catalase to culture medium increased the period of viability of Beggiatoa from 1 week to 2 months. Addition of catalase also produced a marked increase in cell yield and enzyme activity. Cultures grown without catalase exhibited an absorption peak characteristic of peroxides. This absorption peak was removed by addition of catalase during or after growth. Oxygen was required for growth, but carbon dioxide was not produced. Malate and acetate stimulated growth at low concentrations. Glucose and thiosulfate were not oxidized, and cytochromes were not detectable by spectrophotometric analysis.

  7. Economic growth and energy regulation in the environmental Kuznets curve.

    PubMed

    Lorente, Daniel Balsalobre; Álvarez-Herranz, Agustín

    2016-08-01

    This study establishes the existence of a pattern of behavior, between economic growth and environmental degradation, consistent with the environmental Kuznets curve (EKC) hypothesis for 17 Organization for Economic Cooperation and Development (OECD) countries between 1990 and 2012. Based on this EKC pattern, it shows that energy regulation measures help reduce per capita greenhouse gas (GHG) emissions. To validate this hypothesis, we also add the explanatory variables: renewable energy promotion, energy innovation processes, and the suppression effect of income level on the contribution of renewable energy sources to total energy consumption. It aims to be a tool for decision-making regarding energy policy. This paper provides a two-stage econometric analysis of instrumental variables with the aim of correcting the existence of endogeneity in the variable GDP per capita, verifying that the instrumental variables used in this research are appropriate for our aim. To this end, it first makes a methodological contribution before incorporating additional variables associated with environmental air pollution into the EKC hypothesis and showing how they positively affect the explanation of the correction in the GHG emission levels. This study concludes that air pollution will not disappear on its own as economic growth increases. Therefore, it is necessary to promote energy regulation measures to reduce environmental pollution.

  8. Environmental conditions and Puumala virus transmission in Belgium

    PubMed Central

    Linard, Catherine; Tersago, Katrien; Leirs, Herwig; Lambin, Eric F

    2007-01-01

    Background Non-vector-borne zoonoses such as Puumala hantavirus (PUUV) can be transmitted directly, by physical contact between infected and susceptible hosts, or indirectly, with the environment as an intermediate. The objective of this study is to better understand the causal link between environmental features and PUUV prevalence in bank vole population in Belgium, and hence with transmission risk to humans. Our hypothesis was that environmental conditions controlling the direct and indirect transmission paths differ, such that the risk of transmission to humans is not only determined by host abundance. We explored the relationship between, on one hand, environmental variables and, on the other hand, host abundance, PUUV prevalence in the host, and human cases of nephropathia epidemica (NE). Statistical analyses were carried out on 17 field sites situated in Belgian broadleaf forests. Results Linear regressions showed that landscape attributes, particularly landscape configuration, influence the abundance of hosts in broadleaf forests. Based on logistic regressions, we show that PUUV prevalence among bank voles is more linked to variables favouring the survival of the virus in the environment, and thus the indirect transmission: low winter temperatures are strongly linked to prevalence among bank voles, and high soil moisture is linked to the number of NE cases among humans. The transmission risk to humans therefore depends on the efficiency of the indirect transmission path. Human risk behaviours, such as the propensity for people to go in forest areas that best support the virus, also influence the number of human cases. Conclusion The transmission risk to humans of non-vector-borne zoonoses such as PUUV depends on a combination of various environmental factors. To understand the complex causal pathways between the environment and disease risk, one should distinguish between environmental factors related to the abundance of hosts such as land

  9. Conditions for super-adiabatic droplet growth after entrainment mixing

    DOE PAGES

    Yang, Fan; Shaw, Raymond; Xue, Huiwen

    2016-07-29

    Cloud droplet response to entrainment and mixing between a cloud and its environment is considered, accounting for subsequent droplet growth during adiabatic ascent following a mixing event. The vertical profile for liquid water mixing ratio after a mixing event is derived analytically, allowing the reduction to be predicted from the mixing fraction and from the temperature and humidity for both the cloud and environment. It is derived for the limit of homogeneous mixing. The expression leads to a critical height above the mixing level: at the critical height the cloud droplet radius is the same for both mixed and unmixedmore » parcels, and the critical height is independent of the updraft velocity and mixing fraction. Cloud droplets in a mixed parcel are larger than in an unmixed parcel above the critical height, which we refer to as the “super-adiabatic” growth region. Analytical results are confirmed with a bin microphysics cloud model. Using the model, we explore the effects of updraft velocity, aerosol source in the environmental air, and polydisperse cloud droplets. Results show that the mixed parcel is more likely to reach the super-adiabatic growth region when the environmental air is humid and clean. It is also confirmed that the analytical predictions are matched by the volume-mean cloud droplet radius for polydisperse size distributions. The findings have implications for the origin of large cloud droplets that may contribute to onset of collision–coalescence in warm clouds.« less

  10. On Stability and the Spectrum Determined Growth Condition for Spatially Periodic Systems

    DTIC Science & Technology

    2005-01-01

    On Stability and the Spectrum Determined Growth Condition for Spatially Periodic Systems Makan Fardad and Bassam Bamieh Abstract— We consider...difficult. This work is partially supported by AFOSR Grant FA9550-04-1-0207. M. Fardad and B. Bamieh are with the Department of Me- chanical and...Environmental Engineering, University of California, Santa Barbara, CA 93105-5070. email: fardad @engineering.ucsb.edu, bamieh@engineering.ucsb.edu. In this

  11. Effects of varying environmental conditions on vegetation response to ozone exposure

    SciTech Connect

    Zaleski, R.T.; Triemer, L.R.

    1995-12-31

    Developing an exposure-effects model for plant response to ozone exposure is a complex process. It is known that ozone must enter the plant through the stomata for an effect to occur. Therefore, ozone uptake is related not only to ambient ozone concentrations, but also to environmental factors which control stomatal movement. In addition, cellular factors within the plant can mitigate ozone impact and ultimately control plant response. This paper presents a review of the scientific literature on plant responses (e.g. visible foliar injury, reductions in growth or yield) to ozone exposures under varying environmental conditions known to affect stomatal aperture. The results of this effort show the importance of considering key environmental factors when developing exposure-effects models.

  12. Growth and condition of juvenile chum and pink salmon in the northeastern Bering Sea

    NASA Astrophysics Data System (ADS)

    Wechter, Melissa E.; Beckman, Brian R.; Andrews, Alexander G., III; Beaudreau, Anne H.; McPhee, Megan V.

    2017-01-01

    As the Arctic continues to warm, abundances of juvenile Pacific salmon (Oncorhynchus spp.) in the northern Bering Sea are expected to increase. However, information regarding the growth and condition of juvenile salmon in these waters is limited. The first objective of this study was to describe relationships between size, growth, and condition of juvenile chum (O. keta) and pink (O. gorbuscha) salmon and environmental conditions using data collected in the northeastern Bering Sea (NEBS) from 2003-2007 and 2009-2012. Salmon collected at stations with greater bottom depths and cooler sea-surface temperature (SST) were longer, reflecting their movement further offshore out of the warmer Alaska Coastal Water mass, as the season progressed. Energy density, after accounting for fish length, followed similar relationships with SST and bottom depth while greater condition (weight-length residuals) was associated with warm SST and shallower stations. We used insulin-like growth factor-1 (IGF-1) concentrations as an indicator of relative growth rate for fishes sampled in 2009-2012 and that found fish exhibited higher IGF-1 concentrations in 2010-2012 than in 2009, although these differences were not clearly attributable to environmental conditions. Our second objective was to compare size and condition of juvenile chum and pink salmon in the NEBS between warm and cool spring thermal regimes of the southeastern Bering Sea (SEBS). This comparison was based on a hypothesis informed by the strong role of sea-ice retreat in the spring for production dynamics in the SEBS and prevailing northward currents, suggesting that feeding conditions in the NEBS may be influenced by production in the SEBS. We found greater length (both species) and condition (pink salmon) in years with warm thermal regimes; however, both of these responses changed more rapidly with day of year in years with cool springs. Finally, we compared indicators of energy allocation between even and odd brood

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

    PubMed

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

    2015-04-15

    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

  14. Degenerate nonlinear programming with a quadratic growth condition.

    SciTech Connect

    Anitescu, M.; Mathematics and Computer Science

    2000-01-01

    We show that the quadratic growth condition and the Mangasarian-Fromovitz constraint qualification (MFCQ) imply that local minima of nonlinear programs are isolated stationary points. As a result, when started sufficiently close to such points, an L1 exact penalty sequential quadratic programming algorithm will induce at least R-linear convergence of the iterates to such a local minimum. We construct an example of a degenerate nonlinear program with a unique local minimum satisfying the quadratic growth and the MFCQ but for which no positive semidefinite augmented Lagrangian exists. We present numerical results obtained using several nonlinear programming packages on this example and discuss its implications for some algorithms.

  15. Interaction of gravity with other environmental factors in growth and development: an introduction.

    PubMed

    Hoson, T

    1999-01-01

    The life of plants and other organisms is governed by the constant force of gravity on earth. The mechanism of graviperception, signal transduction, and gravireaction is one of the major themes in space biology. When gravity controls each step of the life cycle such as growth and development, it does not work alone but operates with the interaction of other environmental factors. In order to understand the role of gravity in regulation of the life cycle, such interactions also should be clarified. Under microgravity conditions in space, various changes are brought about in the process of growth and development. Some changes would be advantageous to organisms, but others would be unfavorable. For overcoming such disadvantages, it may be required to exploit some other environmental factors which substitute for gravity in some properties. In terrestrial plants, gravity can be replaced by light under certain conditions. The gravity-substituting factors may play a principal role in future space development.

  16. Colloid's influences on microalgae growth as a potential environmental factor

    NASA Astrophysics Data System (ADS)

    Zhao, Xinhuai; Zhang, Zhengbin; Liu, Liansheng

    2003-09-01

    The role of colloid as “colloid pump” in the ocean is well known. The important influence of colloid in seawater on the growth of microalga was found in our 1999 2000 study. Colloid concentrates were obtained by employing a cross-flow filtration system to ultrafilter seawater (which had been pre-filtrated by 0.45 μm acetate cellulose membrane) successively with different membranes. Ultrafiltration retentions (we called them colloid concentrates) together with control sample (seawater without colloid) were then inoculated with two species of microalgae and cultivated in selected conditions. Monitoring of microalgae growth during cultivation showed that all colloid concentrates had obvious influence on the growth of the microalgae studied. Addition of Fe(OH)3 colloid or organic colloid (protein or carbohydrate) to the control sample enhanced the microalgae’s growth.

  17. The Characteristics of Cultural Conditions for the Mycelial Growth of Macrolepiota procera

    PubMed Central

    Shim, Sung Mi; Oh, Yun Hee; Lee, Kyung Rim; Kim, Seong Hwan; Im, Kyung Hoan; Kim, Jung Wan; Lee, U Youn; Shim, Jae Ouk; Shim, Mi Ja; Lee, Min Woong; Ro, Hyeon Su; Lee, Hyun Sook

    2005-01-01

    Macrolepiota procera, one of edible mushrooms belongs to Agaricaceae of Basidiomycota, has a good taste and good medicinal value. As a preliminary study for the development of artificial cultivation method of edible mushroom, cultural characteristics of M. procera was investigated on various culture media under different environmental conditions. Mycelial growth was compared on culture media composed of various carbon and nitrogen sources, and C/N ratios. The optimal conditions for the mycelial growth were 30℃ and pH 7. M. procera showed the rapid mycelial growth in the PDA media. The optimal carbon and nitrogen sources were maltose and glycine, respectively. The optimum C/N ratio was about 10 : 1 in case that 1% glucose was supplemented to the basal media as carbon source. PMID:24049468

  18. Unravelling environmental conditions during the Holocene in the Dead Sea region using multiple archives

    NASA Astrophysics Data System (ADS)

    Rambeau, Claire; van Leeuwen, Jacqueline; van der Knaap, Pim; Gobet, Erika

    2016-04-01

    For the most arid parts of the Southern Levant (roughly corresponding to modern Jordan, Israel and Palestine), environmental reconstructions are impeded by the limited number of archives, and the frequent contradictions between individual palaeoenvironmental records. The Southern Levant is characterised by steep climate gradients; local conditions presently range from arid to dry Mediterranean, with limits that may have fluctuated during the Holocene. This further complicates the determination of site-specific past environmental conditions. Understanding past climate and environmental evolution through time, at a local level, is however crucial to compare these with societal evolution during the Holocene, which features major cultural developments such as cereal cultivation, animal domestication, water management, as well as times of preferential settlement growth or site abandonment. This contribution proposes to examine the different archives available for the Dead Sea region, paying special attention to the most recent pollen data obtained from the area. It will particularly critically compare local to regional-scale information, and try to decipher the main evolutions of environmental conditions during the Holocene in arid and semi-arid Southern Levant.

  19. [Environmental pollution and population growth in Latin America].

    PubMed

    Viel, B

    1983-01-01

    3 factors are always involved in causation of infectious disease: the causal organism, an adverse environment, and nutritional status. As knowledge of degenerative and mental illnesses advances, their relationship to environmental problems becomes clearer. Health in the human being as in all living things is the product of ecological equilibrium. In countries with high mortality rates, the majority of deaths occur in the early years of life. Countries enjoying low mortality rates are those that have protected themselves against environmental deterioration. The Roman civilization, the 1st to have large cities, built aqueducts to protect the water supply from contamination. With the disappearance of the Roman Empire the concern for purity of the water supply also disappeared, and the cities of the Middle Ages became breeding grounds for epidemics. In the early 19th century John Snow demonstrated the role of water in the transmission of cholera and thereafter the concern with potable water and sewage disposal was reborn. The Industrial Revolution eventually allowed sufficient accumulation of wealth to permit improved nutrition. Environmental sanitation and improved food supply produced a new ecological equilibrium, and Western Europe began to have lower and lower mortality rates. Paralleling the decline in deaths a new spirit of responsible parenthood and delayed marriage was lowering birth rates. Population growth, which never exceeded 1%, had the additional escape valve of emigration to America and Australia. The true cause of environmental degradation is man. When human beings were few their contaminants were readily obsorbed by the environment, but as they proliferate the environment is increasingly unable to absorb their pollution by natural processes. Industrial fumes, deforestation, and polluted rivers are only the symptoms of contamination. In the developed countries, technological innovations minimizing industrial pollution and lower population growth are

  20. Multimodal cues improve prey localization under complex environmental conditions

    PubMed Central

    Rhebergen, F.; Taylor, R. C.; Ryan, M. J.; Page, R. A.; Halfwerk, W.

    2015-01-01

    Predators often eavesdrop on sexual displays of their prey. These displays can provide multimodal cues that aid predators, but the benefits in attending to them should depend on the environmental sensory conditions under which they forage. We assessed whether bats hunting for frogs use multimodal cues to locate their prey and whether their use varies with ambient conditions. We used a robotic set-up mimicking the sexual display of a male túngara frog (Physalaemus pustulosus) to test prey assessment by fringe-lipped bats (Trachops cirrhosus). These predatory bats primarily use sound of the frog's call to find their prey, but the bats also use echolocation cues returning from the frog's dynamically moving vocal sac. In the first experiment, we show that multimodal cues affect attack behaviour: bats made narrower flank attack angles on multimodal trials compared with unimodal trials during which they could only rely on the sound of the frog. In the second experiment, we explored the bat's use of prey cues in an acoustically more complex environment. Túngara frogs often form mixed-species choruses with other frogs, including the hourglass frog (Dendropsophus ebraccatus). Using a multi-speaker set-up, we tested bat approaches and attacks on the robofrog under three different levels of acoustic complexity: no calling D. ebraccatus males, two calling D. ebraccatus males and five D. ebraccatus males. We found that bats are more directional in their approach to the robofrog when more D. ebraccatus males were calling. Thus, bats seemed to benefit more from multimodal cues when confronted with increased levels of acoustic complexity in their foraging environments. Our data have important consequences for our understanding of the evolution of multimodal sexual displays as they reveal how environmental conditions can alter the natural selection pressures acting on them. PMID:26336176

  1. Multimodal cues improve prey localization under complex environmental conditions.

    PubMed

    Rhebergen, F; Taylor, R C; Ryan, M J; Page, R A; Halfwerk, W

    2015-09-07

    Predators often eavesdrop on sexual displays of their prey. These displays can provide multimodal cues that aid predators, but the benefits in attending to them should depend on the environmental sensory conditions under which they forage. We assessed whether bats hunting for frogs use multimodal cues to locate their prey and whether their use varies with ambient conditions. We used a robotic set-up mimicking the sexual display of a male túngara frog (Physalaemus pustulosus) to test prey assessment by fringe-lipped bats (Trachops cirrhosus). These predatory bats primarily use sound of the frog's call to find their prey, but the bats also use echolocation cues returning from the frog's dynamically moving vocal sac. In the first experiment, we show that multimodal cues affect attack behaviour: bats made narrower flank attack angles on multimodal trials compared with unimodal trials during which they could only rely on the sound of the frog. In the second experiment, we explored the bat's use of prey cues in an acoustically more complex environment. Túngara frogs often form mixed-species choruses with other frogs, including the hourglass frog (Dendropsophus ebraccatus). Using a multi-speaker set-up, we tested bat approaches and attacks on the robofrog under three different levels of acoustic complexity: no calling D. ebraccatus males, two calling D. ebraccatus males and five D. ebraccatus males. We found that bats are more directional in their approach to the robofrog when more D. ebraccatus males were calling. Thus, bats seemed to benefit more from multimodal cues when confronted with increased levels of acoustic complexity in their foraging environments. Our data have important consequences for our understanding of the evolution of multimodal sexual displays as they reveal how environmental conditions can alter the natural selection pressures acting on them.

  2. Influence of Environmental Variables on Gambierdiscus spp. (Dinophyceae) Growth and Distribution.

    PubMed

    Xu, Yixiao; Richlen, Mindy L; Liefer, Justin D; Robertson, Alison; Kulis, David; Smith, Tyler B; Parsons, Michael L; Anderson, Donald M

    2016-01-01

    Benthic dinoflagellates in the genus Gambierdiscus produce the ciguatoxin precursors responsible for the occurrence of ciguatera toxicity. The prevalence of ciguatera toxins in fish has been linked to the presence and distribution of toxin-producing species in coral reef ecosystems, which is largely determined by the presence of suitable benthic habitat and environmental conditions favorable for growth. Here using single factor experiments, we examined the effects of salinity, irradiance, and temperature on growth of 17 strains of Gambierdiscus representing eight species/phylotypes (G. belizeanus, G. caribaeus, G. carolinianus, G. carpenteri, G. pacificus, G. silvae, Gambierdiscus sp. type 4-5), most of which were established from either Marakei Island, Republic of Kiribati, or St. Thomas, United States Virgin Island (USVI). Comparable to prior studies, growth rates fell within the range of 0-0.48 divisions day(-1). In the salinity and temperature studies, Gambierdiscus responded in a near Gaussian, non-linear manner typical for such studies, with optimal and suboptimal growth occurring in the range of salinities of 25 and 45 and 21.0 and 32.5°C. In the irradiance experiment, no mortality was observed; however, growth rates at 55 μmol photons · m(-2) · s(-1) were lower than those at 110-400 μmol photons · m(-2) · s(-1). At the extremes of the environmental conditions tested, growth rates were highly variable, evidenced by large coefficients of variability. However, significant differences in intraspecific growth rates were typically found only at optimal or near-optimal growth conditions. Polynomial regression analyses showed that maximum growth occurred at salinity and temperature levels of 30.1-38.5 and 23.8-29.2°C, respectively. Gambierdiscus growth patterns varied among species, and within individual species: G. belizeanus, G. caribaeus, G. carpenteri, and G. pacificus generally exhibited a wider range of tolerance to environmental conditions, which may

  3. Influence of Environmental Variables on Gambierdiscus spp. (Dinophyceae) Growth and Distribution

    PubMed Central

    Xu, Yixiao; Richlen, Mindy L.; Liefer, Justin D.; Robertson, Alison; Kulis, David; Smith, Tyler B.; Parsons, Michael L.; Anderson, Donald M.

    2016-01-01

    Benthic dinoflagellates in the genus Gambierdiscus produce the ciguatoxin precursors responsible for the occurrence of ciguatera toxicity. The prevalence of ciguatera toxins in fish has been linked to the presence and distribution of toxin-producing species in coral reef ecosystems, which is largely determined by the presence of suitable benthic habitat and environmental conditions favorable for growth. Here using single factor experiments, we examined the effects of salinity, irradiance, and temperature on growth of 17 strains of Gambierdiscus representing eight species/phylotypes (G. belizeanus, G. caribaeus, G. carolinianus, G. carpenteri, G. pacificus, G. silvae, Gambierdiscus sp. type 4–5), most of which were established from either Marakei Island, Republic of Kiribati, or St. Thomas, United States Virgin Island (USVI). Comparable to prior studies, growth rates fell within the range of 0–0.48 divisions day-1. In the salinity and temperature studies, Gambierdiscus responded in a near Gaussian, non-linear manner typical for such studies, with optimal and suboptimal growth occurring in the range of salinities of 25 and 45 and 21.0 and 32.5°C. In the irradiance experiment, no mortality was observed; however, growth rates at 55μmol photons · m-2 · s-1 were lower than those at 110–400μmol photons · m-2 · s-1. At the extremes of the environmental conditions tested, growth rates were highly variable, evidenced by large coefficients of variability. However, significant differences in intraspecific growth rates were typically found only at optimal or near-optimal growth conditions. Polynomial regression analyses showed that maximum growth occurred at salinity and temperature levels of 30.1–38.5 and 23.8–29.2°C, respectively. Gambierdiscus growth patterns varied among species, and within individual species: G. belizeanus, G. caribaeus, G. carpenteri, and G. pacificus generally exhibited a wider range of tolerance to environmental conditions, which may

  4. Antimicrobial Treatment Improves Mycobacterial Survival in Nonpermissive Growth Conditions

    PubMed Central

    Turapov, Obolbek; Waddell, Simon J.; Burke, Bernard; Glenn, Sarah; Sarybaeva, Asel A.; Tudo, Griselda; Labesse, Gilles; Young, Danielle I.; Young, Michael; Andrew, Peter W.; Butcher, Philip D.; Cohen-Gonsaud, Martin

    2014-01-01

    Antimicrobials targeting cell wall biosynthesis are generally considered inactive against nonreplicating bacteria. Paradoxically, we found that under nonpermissive growth conditions, exposure of Mycobacterium bovis BCG bacilli to such antimicrobials enhanced their survival. We identified a transcriptional regulator, RaaS (for regulator of antimicrobial-assisted survival), encoded by bcg1279 (rv1219c) as being responsible for the observed phenomenon. Induction of this transcriptional regulator resulted in reduced expression of specific ATP-dependent efflux pumps and promoted long-term survival of mycobacteria, while its deletion accelerated bacterial death under nonpermissive growth conditions in vitro and during macrophage or mouse infection. These findings have implications for the design of antimicrobial drug combination therapies for persistent infectious diseases, such as tuberculosis. PMID:24590482

  5. Suppression of Elongation and Growth of Tomato Seedlings by Auxin Biosynthesis Inhibitors and Modeling of the Growth and Environmental Response

    PubMed Central

    Higashide, Tadahisa; Narukawa, Megumi; Shimada, Yukihisa; Soeno, Kazuo

    2014-01-01

    To develop a growth inhibitor, the effects of auxin inhibitors were investigated. Application of 30 μM L-α-aminooxy-β-phenylpropionic acid (AOPP) or (S)-methyl 2-((1,3-dioxoisoindolin-2-yl)oxy)-3-phenylpropanoate (KOK1101), decreased the endogenous IAA levels in tomato seedlings at 8 days after sowing. Then, 10–1200 μM AOPP or KOK1101 were sprayed on the leaves and stem of 2–3 leaf stage tomato plants grown under a range of environmental conditions. We predicted plant growth and environmental response using a model based on the observed suppression of leaf enlargement. Spraying AOPP or KOK1101 decreased stem length and leaf area. Concentration-dependent inhibitions and dose response curves were observed. Although the effects of the inhibitors on dry weight varied according to the environmental conditions, the net assimilation rate was not influenced by the inhibitors. Accordingly, the observed decrease in dry weight caused by the inhibitors may result from decreased leaf area. Validation of the model based on observed data independent of the dataset showed good correlations between the observed and predicted values of dry weight and leaf area index. PMID:24690949

  6. Persistent Environmental Toxicants in Breast Milk and Rapid Infant Growth.

    PubMed

    Criswell, Rachel; Lenters, Virissa; Mandal, Siddhartha; Stigum, Hein; Iszatt, Nina; Eggesbø, Merete

    2017-01-01

    Many environmental toxicants are passed to infants in utero and through breast milk. Exposure to toxicants during the perinatal period can alter growth patterns, impairing growth or increasing obesity risk. Previous studies have focused on only a few toxicants at a time, which may confound results. We investigated levels of 26 toxicants in breast milk and their associations with rapid infant growth, a risk factor for later obesity. We used data from the Norwegian HUMIS study, a multi-center cohort of 2,606 mothers and newborns enrolled between 2002 and 2008. Milk samples collected 1 month after delivery from a subset of 789 women oversampled by overweight were analyzed for toxicants including polychlorinated biphenyls (PCBs), heavy metals, and pesticides. Growth was defined as change in weight-for-age z-score between 0 and 6 months among the HUMIS population, and rapid growth was defined as change in z-score above 0.67. We used a Bayesian variable selection method to determine the exposures that most explained variation in the outcome. Identified toxicants were included in logistic and linear regression models to estimate associations with growth, adjusting for maternal age, smoking, education, pre-pregnancy body mass index (BMI), gestational weight gain, parity, child sex, cumulative breastfeeding, birth weight, gestational age, and preterm status. Of 789 infants, 19.2% displayed rapid growth. The median maternal age was 29.6 years, and the median pre-pregnancy BMI was 24.0 kg/m2, with 45.3% of mothers overweight or obese. Rapid growers were more likely to be firstborn. Hexachlorobenzene, β-hexachlorocyclohexane (β-HCH), and PCB-74 were identified in the variable selection method. An interquartile range (IQR) increase in β-HCH exposure was associated with a lower odds of rapid growth (OR 0.63, 95% CI 0.42-0.94). Newborns exposed to high levels of β-HCH showed reduced infant growth (β = -0.03, 95% CI -0.05 to -0.01 for IQR increase in breast milk concentration

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

    NASA Astrophysics Data System (ADS)

    Biryukov, Mikhail; Dippold, Michaela; Kuzyakov, Yakov

    2014-05-01

    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

  8. Heterogeneous nucleation and growth of nanoparticles at environmental interfaces

    DOE PAGES

    Jun, Young -Shin; Kim, Doyoon; Neil, Chelsea W.

    2016-08-11

    Here, mineral nucleation is a phase transformation of aqueous components to solids with an accompanying creation of new surfaces. In this evolutional, yet elusive, process, nuclei often form at environmental interfaces, which provide remarkably reactive sites for heterogeneous nucleation and growth. Naturally occurring nucleation processes significantly contribute to the biogeochemical cycles of important components in the Earth’s crust, such as iron and manganese oxide minerals and calcium carbonate. However, in recent decades, these cycles have been significantly altered by anthropogenic activities, which affect the aqueous chemistry and equilibrium of both surface and subsurface systems. These alterations can trigger the dissolutionmore » of existing minerals and formation of new nanoparticles (i.e., nucleation and growth) and consequently change the porosity and permeability of geomedia in subsurface environments. Newly formed nanoparticles can also actively interact with components in natural and engineered aquatic systems, including those posing a significant hazard such as arsenic. These interactions can bilaterally influence the fate and transport of both newly formed nanoparticles and aqueous components. Due to their importance in natural and engineered processes, heterogeneous nucleation at environmental interfaces has started to receive more attention. However, a lack of time-resolved in situ analyses makes the evaluation of heterogeneous nucleation challenging because the physicochemical properties of both the nuclei and surfaces significantly and dynamically change with time and aqueous chemistry. This Account reviews our in situ kinetic studies of the heterogeneous nucleation and growth behaviors of iron(III) (hydr)oxide, calcium carbonate, and manganese (hydr)oxide minerals in aqueous systems. In particular, we utilized simultaneous small-angle and grazing incidence small-angle X-ray scattering (SAXS/GISAXS) to investigate in situ and in real

  9. The community conditioning hypothesis and its application to environmental toxicology

    SciTech Connect

    Matthews, R.A.; Landis, W.G.; Matthews, G.B.

    1996-04-01

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

  10. Leaching of metals from cement under simulated environmental conditions.

    PubMed

    Lu, Huixia; Wei, Fang; Tang, Jingchun; Giesy, John P

    2016-03-15

    Leaching of metals from cement under various environmental conditions was measured to evaluate their environmental safety. A cement product containing clinker, which was produced from cement kiln co-processing of hazardous wastes, was solidified and leaching of metals was characterized using the 8-period test. Concentrations and speciation of metals in cements were determined. Effects of ambient environment and particle size on leachability of metals and mineralogical phases of cement mortars were evaluated by use of XRD and SEM. Results indicated that metals in cements were leachable in various media in descending order of: sea water, groundwater and acid rain. Cr, Ni, As, Co and V were leached by simulated sea water, while Cu, Cd, Pb, Zn, Mn, Sb and Tl were not leached in simulated sea water, groundwater or acid rain. When exposed to simulated acid rain or groundwater, amounts of Cr, Ni, As and V leached was inversely proportional to particle size of cement mortar. According to the one-dimensional diffusion equation, Cr was most leachable and the cumulative leached mass was predicted to be 9.6 mg kg(-1) after 20 years. Results of this study are useful in predicting releases of metals from cement products containing ash and clinkers cement kiln co-processing of hazardous wastes, so that they can be safely applied in the environment.

  11. K, U, and Th behavior in Martian environmental conditions

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  12. K, U, and Th behavior in Martian environmental conditions

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  13. Environmental conditioning for textile yarn-spinning mill

    SciTech Connect

    Gengler, M.

    1996-06-01

    In mid-1993, Parkdale Mills, Inc., entered into a contract with Pneumafil Corporation to design and construct a total environmental conditioning system for their Plant No. 5 Open-End Spinning Room modernization program. This system was put into use in July 1994. Parkdale Mills in Gastonia, N.C. is one of the true innovators in the textile yarn-spinning business. The company presented a challenge to press technology to a new level to meet a number of well-defined goals. These goals were as follows: (1) Room temperature and humidity control -- Very accurate control to enable consistent production of the highest possible quality of yarn; (2) Energy efficiency -- The best achievable to assure the lowest possible production cost to the mill; (3) Dust levels -- The lowest possible within the mill for compliance with OSHA dust standards and for the least impact on yarn quality; and (4) Installed cost -- Not to exceed that of a conventionally designed system.

  14. Pervaporative irrigation: a flow rate driven by environmental conditions

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

  15. Environmental and Sanitary Conditions of Guanabara Bay, Rio de Janeiro

    PubMed Central

    Fistarol, Giovana O.; Coutinho, Felipe H.; Moreira, Ana Paula B.; Venas, Tainá; Cánovas, Alba; de Paula, Sérgio E. M.; Coutinho, Ricardo; de Moura, Rodrigo L.; Valentin, Jean Louis; Tenenbaum, Denise R.; Paranhos, Rodolfo; do Valle, Rogério de A. B.; Vicente, Ana Carolina P.; Amado Filho, Gilberto M.; Pereira, Renato Crespo; Kruger, Ricardo; Rezende, Carlos E.; Thompson, Cristiane C.; Salomon, Paulo S.; Thompson, Fabiano L.

    2015-01-01

    Guanabara Bay is the second largest bay in the coast of Brazil, with an area of 384 km2. In its surroundings live circa 16 million inhabitants, out of which 6 million live in Rio de Janeiro city, one of the largest cities of the country, and the host of the 2016 Olympic Games. Anthropogenic interference in Guanabara Bay area started early in the XVI century, but environmental impacts escalated from 1930, when this region underwent an industrialization process. Herein we present an overview of the current environmental and sanitary conditions of Guanabara Bay, a consequence of all these decades of impacts. We will focus on microbial communities, how they may affect higher trophic levels of the aquatic community and also human health. The anthropogenic impacts in the bay are flagged by heavy eutrophication and by the emergence of pathogenic microorganisms that are either carried by domestic and/or hospital waste (e.g., virus, KPC-producing bacteria, and fecal coliforms), or that proliferate in such conditions (e.g., vibrios). Antibiotic resistance genes are commonly found in metagenomes of Guanabara Bay planktonic microorganisms. Furthermore, eutrophication results in recurrent algal blooms, with signs of a shift toward flagellated, mixotrophic groups, including several potentially harmful species. A recent large-scale fish kill episode, and a long trend decrease in fish stocks also reflects the bay’s degraded water quality. Although pollution of Guanabara Bay is not a recent problem, the hosting of the 2016 Olympic Games propelled the government to launch a series of plans to restore the bay’s water quality. If all plans are fully implemented, the restoration of Guanabara Bay and its shores may be one of the best legacies of the Olympic Games in Rio de Janeiro. PMID:26635734

  16. Environmental and Sanitary Conditions of Guanabara Bay, Rio de Janeiro.

    PubMed

    Fistarol, Giovana O; Coutinho, Felipe H; Moreira, Ana Paula B; Venas, Tainá; Cánovas, Alba; de Paula, Sérgio E M; Coutinho, Ricardo; de Moura, Rodrigo L; Valentin, Jean Louis; Tenenbaum, Denise R; Paranhos, Rodolfo; do Valle, Rogério de A B; Vicente, Ana Carolina P; Amado Filho, Gilberto M; Pereira, Renato Crespo; Kruger, Ricardo; Rezende, Carlos E; Thompson, Cristiane C; Salomon, Paulo S; Thompson, Fabiano L

    2015-01-01

    Guanabara Bay is the second largest bay in the coast of Brazil, with an area of 384 km(2). In its surroundings live circa 16 million inhabitants, out of which 6 million live in Rio de Janeiro city, one of the largest cities of the country, and the host of the 2016 Olympic Games. Anthropogenic interference in Guanabara Bay area started early in the XVI century, but environmental impacts escalated from 1930, when this region underwent an industrialization process. Herein we present an overview of the current environmental and sanitary conditions of Guanabara Bay, a consequence of all these decades of impacts. We will focus on microbial communities, how they may affect higher trophic levels of the aquatic community and also human health. The anthropogenic impacts in the bay are flagged by heavy eutrophication and by the emergence of pathogenic microorganisms that are either carried by domestic and/or hospital waste (e.g., virus, KPC-producing bacteria, and fecal coliforms), or that proliferate in such conditions (e.g., vibrios). Antibiotic resistance genes are commonly found in metagenomes of Guanabara Bay planktonic microorganisms. Furthermore, eutrophication results in recurrent algal blooms, with signs of a shift toward flagellated, mixotrophic groups, including several potentially harmful species. A recent large-scale fish kill episode, and a long trend decrease in fish stocks also reflects the bay's degraded water quality. Although pollution of Guanabara Bay is not a recent problem, the hosting of the 2016 Olympic Games propelled the government to launch a series of plans to restore the bay's water quality. If all plans are fully implemented, the restoration of Guanabara Bay and its shores may be one of the best legacies of the Olympic Games in Rio de Janeiro.

  17. Degradation in perovskite solar cells stored under different environmental conditions

    NASA Astrophysics Data System (ADS)

    Chauhan, Abhishek K.; Kumar, Pankaj

    2017-08-01

    Investigations carried out on the degradation of perovskite solar cells (PSCs) stored in different open air environmental conditions are reported here. The solar cells were stored in the open in the dark inside the laboratory (relative humidity 47  ±  5%, temperature 23  ±  4 °C), under compact fluorescent lamp (CFL) illumination (irradiance 10 mW cm2, relative humidity 47  ±  5%, temperature 23  ±  4 °C) and under natural sunlight outside the laboratory. In the outdoor storage situation the surrounding conditions varied from time to time and the environmental conditions during the day (irradiance 100 mW/cm2, relative humidity ~18%, temperature ~45 °C at noon) were entirely different from those at night (irradiance 0 mW/cm2, relative humidity ~66%, temperature ~16 °C at midnight). The photovoltaic parameters were measured from time to time inside the laboratory as per the International Summit on Organic Photovoltaic Stability (ISOS) protocols. All the photovoltaic parameters, such as short circuit current density (J sc), open circuit voltage (V oc), fill factor (FF) and power conversion efficiency (PCE), of the solar cells stored outdoors decayed more rapidly than those stored under CFL or in the dark. The solar cells stored in the dark exhibited maximum stability. While the encapsulated solar cells stored outdoors were completely dead after about 560 h, the solar cells stored under CFL illumination retained  >60% of their initial efficiency even after 1100 h. However, the solar cells stored in the dark and tested up to ~1100 h did not show any degradation in PCE but on the contrary exhibited slight improvement, and this improvement was mainly because of improvement in their V oc. Rapid degradation in the open air outside the laboratory under direct sunlight compared with the dark and CFL storage has been attributed to high temperature during the day, high humidity at night, high solar illumination intensity and the

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

    PubMed

    Perkowski, Juliusz; Basiński, Tomasz; Wiwart, Marian; Kostecki, Marian; Buśko, Maciej; Matysiak, Anna

    2008-01-01

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

  19. Effect of lighting conditions on zebrafish growth and development.

    PubMed

    Villamizar, Natalia; Vera, Luisa María; Foulkes, Nicholas Simon; Sánchez-Vázquez, Francisco Javier

    2014-04-01

    In the underwater environment, the properties of light (intensity and spectrum) change rapidly with depth and water quality. In this article, we have described how and to what extent lighting conditions can influence the development, growth, and survival of zebrafish. Fertilized eggs and the corresponding larvae were exposed to different visible light wavelengths (violet, blue, green, yellow, red, and white) in a 12-h light-12-h dark (LD) cycle until 30 days posthatching (dph), when the expression of morphometric parameters and growth (igf1a, igf2a)- and stress-related (crh and pomca) genes were examined. Another group of larvae was raised under constant darkness (DD) until 5 or 10 dph, after which they were transferred to a LD of white light. A third group remained under DD to investigate the effects of light deprivation upon zebrafish development. The results revealed that the hatching rate was highest under blue and violet light, while total length at 30 dph was greatest under blue, white, and violet light. Red light led to reduced feeding activity and poor survival (100% mortality). Larvae raised under constant white light (LL) showed a higher proportion of malformations, as did larvae raised under LD violet light. The expression of growth and stress factors was upregulated in the violet (igf1a, igf2a, pomca, and chr) and blue (igf2a) groups, which is consistent with the higher growth recorded and the higher proportion of malformations detected under the violet light. All larvae kept under DD died before 18 dph, but the survival rates improved in larvae transferred to LD at 5 dph and at 10 dph. In summary, these findings revealed that lighting conditions are crucial factors influencing zebrafish larval development and growth.

  20. Maternal, social and abiotic environmental effects on growth vary across life stages in a cooperative mammal.

    PubMed

    English, Sinead; Bateman, Andrew W; Mares, Rafael; Ozgul, Arpat; Clutton-Brock, Tim H

    2014-03-01

    Resource availability plays a key role in driving variation in somatic growth and body condition, and the factors determining access to resources vary considerably across life stages. Parents and carers may exert important influences in early life, when individuals are nutritionally dependent, with abiotic environmental effects having stronger influences later in development as individuals forage independently. Most studies have measured specific factors influencing growth across development or have compared relative influences of different factors within specific life stages. Such studies may not capture whether early-life factors continue to have delayed effects at later stages, or whether social factors change when individuals become nutritionally independent and adults become competitors for, rather than providers of, food. Here, we examined variation in the influence of the abiotic, social and maternal environment on growth across life stages in a wild population of cooperatively breeding meerkats. Cooperatively breeding vertebrates are ideal for investigating environmental influences on growth. In addition to experiencing highly variable abiotic conditions, cooperative breeders are typified by heterogeneity both among breeders, with mothers varying in age and social status, and in the number of carers present. Recent rainfall had a consistently marked effect on growth across life stages, yet other seasonal terms only influenced growth during stages when individuals were growing fastest. Group size and maternal dominance status had positive effects on growth during the period of nutritional dependence on carers, but did not influence mass at emergence (at 1 month) or growth at independent stages (>4 months). Pups born to older mothers were lighter at 1 month of age and subsequently grew faster as subadults. Males grew faster than females during the juvenile and subadult stage only. Our findings demonstrate the complex ways in which the external environment

  1. Maternal, social and abiotic environmental effects on growth vary across life stages in a cooperative mammal

    PubMed Central

    English, Sinead; Bateman, Andrew W; Mares, Rafael; Ozgul, Arpat; Clutton-Brock, Tim H

    2014-01-01

    Resource availability plays a key role in driving variation in somatic growth and body condition, and the factors determining access to resources vary considerably across life stages. Parents and carers may exert important influences in early life, when individuals are nutritionally dependent, with abiotic environmental effects having stronger influences later in development as individuals forage independently. Most studies have measured specific factors influencing growth across development or have compared relative influences of different factors within specific life stages. Such studies may not capture whether early-life factors continue to have delayed effects at later stages, or whether social factors change when individuals become nutritionally independent and adults become competitors for, rather than providers of, food. Here, we examined variation in the influence of the abiotic, social and maternal environment on growth across life stages in a wild population of cooperatively breeding meerkats. Cooperatively breeding vertebrates are ideal for investigating environmental influences on growth. In addition to experiencing highly variable abiotic conditions, cooperative breeders are typified by heterogeneity both among breeders, with mothers varying in age and social status, and in the number of carers present. Recent rainfall had a consistently marked effect on growth across life stages, yet other seasonal terms only influenced growth during stages when individuals were growing fastest. Group size and maternal dominance status had positive effects on growth during the period of nutritional dependence on carers, but did not influence mass at emergence (at 1 month) or growth at independent stages (>4 months). Pups born to older mothers were lighter at 1 month of age and subsequently grew faster as subadults. Males grew faster than females during the juvenile and subadult stage only. Our findings demonstrate the complex ways in which the external environment

  2. A Combination of Extreme Environmental Conditions Favor the Prevalence of Endospore-Forming Firmicutes.

    PubMed

    Filippidou, Sevasti; Wunderlin, Tina; Junier, Thomas; Jeanneret, Nicole; Dorador, Cristina; Molina, Veronica; Johnson, David R; Junier, Pilar

    2016-01-01

    Environmental conditions unsuitable for microbial growth are the rule rather than the exception in most habitats. In response to this, microorganisms have developed various strategies to withstand environmental conditions that limit active growth. Endospore-forming Firmicutes (EFF) deploy a myriad of survival strategies in order to resist adverse conditions. Like many bacterial groups, they can form biofilms and detect nutrient scarcity through chemotaxis. Moreover, within this paraphyletic group of Firmicutes, ecophysiological optima are diverse. Nonetheless, a response to adversity that delimits this group is the formation of wet-heat resistant spores. These strategies are energetically demanding and therefore might affect the biological success of EFF. Therefore, we hypothesize that abundance and diversity of EFF should be maximized in those environments in which the benefits of these survival strategies offsets the energetic cost. In order to address this hypothesis, geothermal and mineral springs and drillings were selected because in these environments of steep physicochemical gradients, diversified survival strategies may become a successful strategy.We collected 71 samples from geothermal and mineral environments characterized by none (null), single or multiple limiting environmental factors (temperature, pH, UV radiation, and specific mineral composition). To measure success, we quantified EFF gene copy numbers (GCN; spo0A gene) in relation to total bacterial GCN (16S rRNA gene), as well as the contribution of EFF to community composition. The quantification showed that relative GCN for EFF reached up to 20% at sites characterized by multiple limiting environmental factors, whereas it corresponded to less than 1% at sites with one or no limiting environmental factor. Pyrosequencing of the 16S rRNA gene supports a higher contribution of EFF at sites with multiple limiting factors. Community composition suggested a combination of phylotypes for which active

  3. A Combination of Extreme Environmental Conditions Favor the Prevalence of Endospore-Forming Firmicutes

    PubMed Central

    Filippidou, Sevasti; Wunderlin, Tina; Junier, Thomas; Jeanneret, Nicole; Dorador, Cristina; Molina, Veronica; Johnson, David R.; Junier, Pilar

    2016-01-01

    Environmental conditions unsuitable for microbial growth are the rule rather than the exception in most habitats. In response to this, microorganisms have developed various strategies to withstand environmental conditions that limit active growth. Endospore-forming Firmicutes (EFF) deploy a myriad of survival strategies in order to resist adverse conditions. Like many bacterial groups, they can form biofilms and detect nutrient scarcity through chemotaxis. Moreover, within this paraphyletic group of Firmicutes, ecophysiological optima are diverse. Nonetheless, a response to adversity that delimits this group is the formation of wet-heat resistant spores. These strategies are energetically demanding and therefore might affect the biological success of EFF. Therefore, we hypothesize that abundance and diversity of EFF should be maximized in those environments in which the benefits of these survival strategies offsets the energetic cost. In order to address this hypothesis, geothermal and mineral springs and drillings were selected because in these environments of steep physicochemical gradients, diversified survival strategies may become a successful strategy.We collected 71 samples from geothermal and mineral environments characterized by none (null), single or multiple limiting environmental factors (temperature, pH, UV radiation, and specific mineral composition). To measure success, we quantified EFF gene copy numbers (GCN; spo0A gene) in relation to total bacterial GCN (16S rRNA gene), as well as the contribution of EFF to community composition. The quantification showed that relative GCN for EFF reached up to 20% at sites characterized by multiple limiting environmental factors, whereas it corresponded to less than 1% at sites with one or no limiting environmental factor. Pyrosequencing of the 16S rRNA gene supports a higher contribution of EFF at sites with multiple limiting factors. Community composition suggested a combination of phylotypes for which active

  4. Environmental sex reversal, Trojan sex genes, and sex ratio adjustment: conditions and population consequences.

    PubMed

    Stelkens, Rike B; Wedekind, Claus

    2010-02-01

    The great diversity of sex determination mechanisms in animals and plants ranges from genetic sex determination (GSD, e.g. mammals, birds, and most dioecious plants) to environmental sex determination (ESD, e.g. many reptiles) and includes a mixture of both, for example when an individual's genetically determined sex is environmentally reversed during ontogeny (ESR, environmental sex reversal, e.g. many fish and amphibia). ESD and ESR can lead to widely varying and unstable population sex ratios. Populations exposed to conditions such as endocrine-active substances or temperature shifts may decline over time due to skewed sex ratios, a scenario that may become increasingly relevant with greater anthropogenic interference on watercourses. Continuous exposure of populations to factors causing ESR could lead to the extinction of genetic sex factors and may render a population dependent on the environmental factors that induce the sex change. However, ESR also presents opportunities for population management, especially if the Y or W chromosome is not, or not severely, degenerated. This seems to be the case in many amphibians and fish. Population growth or decline in such species can potentially be controlled through the introduction of so-called Trojan sex genes carriers, individuals that possess sex chromosomes or genes opposite from what their phenotype predicts. Here, we review the conditions for ESR, its prevalence in natural populations, the resulting physiological and reproductive consequences, and how these may become instrumental for population management.

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

    PubMed

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

    2005-01-01

    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.

  6. Environmental conditions for alternative tree cover states in high latitudes

    NASA Astrophysics Data System (ADS)

    Abis, Beniamino; Brovkin, Victor

    2016-04-01

    Previous analysis of the vegetation cover from remote sensing revealed the existence of three alternative modes in the frequency distribution of boreal tree cover: a sparsely vegetated treeless state, a savanna-like state, and a forest state. Identifying which are the regions subject to multimodality, and assessing which are the main factors underlying their existence, is important to project future change of natural vegetation cover and its effect on climate. We study the impact on the forest cover fraction distribution of seven globally-observed environmental factors: mean annual rainfall, mean minimum temperature, growing degree days above 0, permafrost distribution, soil moisture, wildfire occurrence frequency, and thawing depth. Through the use of generalised additive models, regression trees, and conditional histograms, we find that the main factors determining the forest distribution in high latitudes are: permafrost distribution, mean annual rainfall, mean minimum temperature, soil moisture, and wildfire frequency. Additionally, we find differences between regions within the boreal area, such as Eurasia, Eastern North America, and Western North America. Furthermore, using a classification based on these factors, we show the existence and location of alternative tree cover states under the same climate conditions in the boreal region. These are areas of potential interest for a more detailed analysis of land-atmosphere interactions.

  7. Environmental safety conditions for mobile base stations in Alexandria.

    PubMed

    el-Shal, W; el-Sebaie, O

    2000-01-01

    The use of wireless communications devices e.g. cellular phones is increasing rapidly all over the world and in Egypt as well. This translates into a potentially significant public health problem: how far is the risk associated with these devices? Another risk is expected from the cellular towers or base stations, which transmit and receive these electromagnetic waves. Usually, these base stations should be constructed over residential buildings to cover all areas. Considering the increased public awareness about electromagnetic fields (EMF) exposure associated with these towers, this work aimed at investigation and evaluation of authorized environmental safety conditions for some mobile base stations in different districts of Alexandria city. The different mobile base stations were investigated for 12 standard safety specifications of the buildings' roofs on which mobile base stations are constructed. Although some of the standard specifications in the examined base stations were in compliance with standard specifications, some items were not in a safe condition. Only base stations F & G had complete safe conditions for all investigated items because of being erected on lighting towers of a sports stadium. On the other hand, base stations C, D, E, I, J, K, L1 & L2 needed a raise in the height of the antennas over buildings' roofs of 1-4.5 m. However, base stations C, D, H, K, L1 & L2 may pose a risk to near living population and consequently the towers have to be moved away. The violating distances are 3, 5.5, 3, 4.5, 4, 3 meters, respectively, while the environmental standard is 6 m. Therefore, the towers should be moved away from these populated areas Nevertheless, guided directions should be constructed in all base stations to warn close living population. Safety regulations as well as frequent inspection need to be applied, on both Egyptian mobile phone companies, to ensure the application of all standard specifications. A significant research effort is needed

  8. Growth of Heterostegina depressa under natural and laboratory conditions

    PubMed Central

    Eder, Wolfgang; Briguglio, Antonino; Hohenegger, Johann

    2016-01-01

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

  9. Properties of Trichomonas vaginalis grown under chemostat controlled growth conditions.

    PubMed Central

    Lehker, M W; Alderete, J F

    1990-01-01

    Trichomonas vaginalis isolates NYH 286 and IR 78 were grown in continuous flow culture conditions in a complex trypticase-yeast extract-maltose medium supplemented with heat-inactivated horse serum. Parasites could be stably maintained in the chemostat at high densities ranging from 1 x 10(6) to 1 x 10(7) organisms ml-1. Growth densities, acid production, and profiles of total versus secreted trichomonad proteins were characterised at different rates of growth and pH. Growth rate influenced the extent of parasite production of acid and the shedding of proteins into the medium but had no effect on overall parasite density. Lowering the pH from 6.0 to 5.0 resulted both in a decrease of cell density and acid production. At pH 4.5 isolate IR 78 but not NYH 286 was capable of growth and multiplication, showing the ability of some isolates to survive at the vaginal pH of healthy individuals. At this lower pH, however, isolate NYH 286 but not IR 78 synthesised new proteins which were detectable in stained gels. Also, inoculation of the chemostat with isolate NYH 286 comprising a mixture of fluorescent (positive, pos) and non-fluorescent (negative, neg) trichomonads as defined by monoclonal antibody reactivity to a surface immunogen resulted in a change in the parasite population to an almost homogeneous neg phenotype. These neg phenotype organisms switched back to pos phenotype after transfer to test tubes. Images PMID:2370063

  10. Properties of Trichomonas vaginalis grown under chemostat controlled growth conditions.

    PubMed

    Lehker, M W; Alderete, J F

    1990-06-01

    Trichomonas vaginalis isolates NYH 286 and IR 78 were grown in continuous flow culture conditions in a complex trypticase-yeast extract-maltose medium supplemented with heat-inactivated horse serum. Parasites could be stably maintained in the chemostat at high densities ranging from 1 x 10(6) to 1 x 10(7) organisms ml-1. Growth densities, acid production, and profiles of total versus secreted trichomonad proteins were characterised at different rates of growth and pH. Growth rate influenced the extent of parasite production of acid and the shedding of proteins into the medium but had no effect on overall parasite density. Lowering the pH from 6.0 to 5.0 resulted both in a decrease of cell density and acid production. At pH 4.5 isolate IR 78 but not NYH 286 was capable of growth and multiplication, showing the ability of some isolates to survive at the vaginal pH of healthy individuals. At this lower pH, however, isolate NYH 286 but not IR 78 synthesised new proteins which were detectable in stained gels. Also, inoculation of the chemostat with isolate NYH 286 comprising a mixture of fluorescent (positive, pos) and non-fluorescent (negative, neg) trichomonads as defined by monoclonal antibody reactivity to a surface immunogen resulted in a change in the parasite population to an almost homogeneous neg phenotype. These neg phenotype organisms switched back to pos phenotype after transfer to test tubes.

  11. Guaranteeing robustness of structural condition monitoring to environmental variability

    NASA Astrophysics Data System (ADS)

    Van Buren, Kendra; Reilly, Jack; Neal, Kyle; Edwards, Harry; Hemez, François

    2017-01-01

    Advances in sensor deployment and computational modeling have allowed significant strides to be recently made in the field of Structural Health Monitoring (SHM). One widely used SHM strategy is to perform a vibration analysis where a model of the structure's pristine (undamaged) condition is compared with vibration response data collected from the physical structure. Discrepancies between model predictions and monitoring data can be interpreted as structural damage. Unfortunately, multiple sources of uncertainty must also be considered in the analysis, including environmental variability, unknown model functional forms, and unknown values of model parameters. Not accounting for these sources of uncertainty can lead to false-positives or false-negatives in the structural condition assessment. To manage the uncertainty, we propose a robust SHM methodology that combines three technologies. A time series algorithm is trained using "baseline" data to predict the vibration response, compare predictions to actual measurements collected on a potentially damaged structure, and calculate a user-defined damage indicator. The second technology handles the uncertainty present in the problem. An analysis of robustness is performed to propagate this uncertainty through the time series algorithm and obtain the corresponding bounds of variation of the damage indicator. The uncertainty description and robustness analysis are both inspired by the theory of info-gap decision-making. Lastly, an appropriate "size" of the uncertainty space is determined through physical experiments performed in laboratory conditions. Our hypothesis is that examining how the uncertainty space changes throughout time might lead to superior diagnostics of structural damage as compared to only monitoring the damage indicator. This methodology is applied to a portal frame structure to assess if the strategy holds promise for robust SHM. (Publication approved for unlimited, public release on October-28

  12. Upwelling and Other Environmental Influences on Growth of a Nearshore Benthic Fish

    NASA Astrophysics Data System (ADS)

    von Biela, V. R.; Zimmerman, C. E.; Kruse, G. H.; Mueter, F. J.; Black, B.; Douglas, D. C.; Bodkin, J. L.

    2016-02-01

    The role of upwelling in nearshore benthic systems is more uncertain compared to the relatively strong positive associations with pelagic production. To understand how upwelling and other environmental conditions influence nearshore benthic production, we developed an annual index of production from growth increments recorded in otoliths of kelp greenling (Hexagrammos decagrammus) at nine sites in the seasonally-upwelling California Current and downwelling Alaska Coastal currents. Kelp greenling are a benthic-feeding fish common in kelp forests with food webs sustained by both kelp and phytoplankton primary production. We explored the influence of basin- and local-scale conditions, including upwelling, across all seasons at lags up to two years taken to represent changes in the quantity and quality of prey. Upwelling strength was positively related to fish growth in both current systems, although relationships in the Alaska Coastal Current were indicative of faster growth with relaxed downwelling, rather than upwelling. Looking across a suite of basin- and local-scale environmental indicators, complex relationships emerged in the California Current, with faster growth related to within-year warm conditions and lagged-year cool conditions. In contrast, fish in the downwelling system grew faster both during and subsequent to warm conditions. The complex lag-dependent dynamics in the upwelling system may reflect differences in conditions that promote quantity versus quality of benthic invertebrate prey. Thus, we hypothesize that benthic production is maximized when cool and warm years alternate during periods of high frequency climate variability in the California Current. Such a pattern is consistent with previous findings suggesting that benthic invertebrate abundance (e.g., recruitment) is food-limited during warm years with reduced upwelling, while quality (e.g., energy content) is temperature-limited during cool years.

  13. The Culture Conditions for the Mycelial Growth of Phellinus spp.

    PubMed

    Jo, Woo-Sik; Rew, Young-Hyun; Choi, Sung-Guk; Seo, Geon-Sik; Sung, Jae-Mo; Uhm, Jae-Youl

    2006-12-01

    Phellinus genus belonged to Hymenochaetaceae of Basidiomycetes and has been well known as one of the most popular medicinal mushrooms due to high antitumor activity. This study was carried out to obtain the basic information for mycelial culture conditions of Phellinus linteus, P. baumii, and P. gilvus. According to colony diameter and mycelial density, the media for suitable mycelial growth of them were shown in MEA, glucose peptone, and MCM. The optimum temperature for mycelial growth was 30℃. Carbon and nitrogen sources were mannose and malt extract, respectively. The optimum C/N ratio was 10 : 1 to 5: 1 with 2% glucose concentration, vitamin was thiamine-HCl, organic acid was succinic acid, and mineral salt was MgSO4·7H2O.

  14. The Culture Conditions for the Mycelial Growth of Phellinus spp.

    PubMed Central

    Rew, Young-Hyun; Choi, Sung-Guk; Seo, Geon-Sik; Sung, Jae-Mo; Uhm, Jae-Youl

    2006-01-01

    Phellinus genus belonged to Hymenochaetaceae of Basidiomycetes and has been well known as one of the most popular medicinal mushrooms due to high antitumor activity. This study was carried out to obtain the basic information for mycelial culture conditions of Phellinus linteus, P. baumii, and P. gilvus. According to colony diameter and mycelial density, the media for suitable mycelial growth of them were shown in MEA, glucose peptone, and MCM. The optimum temperature for mycelial growth was 30℃. Carbon and nitrogen sources were mannose and malt extract, respectively. The optimum C/N ratio was 10 : 1 to 5 : 1 with 2% glucose concentration, vitamin was thiamine-HCl, organic acid was succinic acid, and mineral salt was MgSO4·7H2O. PMID:24039499

  15. Influence of growth conditions on barley starch properties.

    PubMed

    Tester, R F

    1997-08-01

    Air equilibrated barley starch comprises amylopectin, amylose, lipid and water. The structure of amylose and amylopectin, and the proportion of amylose in granules is under genetic control and is therefore subject to genotypic variation. The amount of lipid (which is essentially all lysophospholipid) is similarly under genetic control. Environment and especially environmental temperature do, however, have a regulatory effect on the size of starch granules, the amylose to amylopectin ratio and the amount of lipid (which is essentially all complexed with amylose) within barley starch. High growth temperatures probably facilitate amylopectin crystallisation and increase gelatinisation temperatures, (and to some extent the enthalpy of gelatinisation), but delay the onset and depress the extent of swelling of granules when heated in water.

  16. Asynchrony in the growth and motility responses to environmental changes by individual bacterial cells

    SciTech Connect

    Umehara, Senkei; Hattori, Akihiro; Inoue, Ippei; Yasuda, Kenji . E-mail: yasuda.bmi@tmd.ac.jp

    2007-05-04

    Knowing how individual cells respond to environmental changes helps one understand phenotypic diversity in a bacterial cell population, so we simultaneously monitored the growth and motility of isolated motile Escherichia coli cells over several generations by using a method called on-chip single-cell cultivation. Starved cells quickly stopped growing but remained motile for several hours before gradually becoming immotile. When nutrients were restored the cells soon resumed their growth and proliferation but remained immotile for up to six generations. A flagella visualization assay suggested that deflagellation underlies the observed loss of motility. This set of results demonstrates that single-cell transgenerational study under well-characterized environmental conditions can provide information that will help us understand distinct functions within individual cells.

  17. Effects of growth conditions on biofilm formation by Actinobacillus pleuropneumoniae

    PubMed Central

    Labrie, Josée; Pelletier-Jacques, Geneviève; Deslandes, Vincent; Ramjeet, Mahendrasingh; Auger, Eliane; Nash, John H.E.; Jacques, Mario

    2010-01-01

    Biofilm formation is an important virulence trait of many bacterial pathogens. It has been reported in the literature that only two of the reference strains of the swine pathogen Actinobacillus pleuropneumoniae, representing serotypes 5b and 11, were able to form biofilm in vitro. In this study, we compared biofilm formation by the serotype 1 reference strain S4074 of A. pleuropneumoniae grown in five different culture media. We observed that strain S4074 of A. pleuropneumoniae is able to form biofilms after growth in one of the culture conditions tested brain heart infusion (BHI medium, supplier B). Confocal laser scanning microscopy using a fluorescent probe specific to the poly-N-acetylglucosamine (PGA) polysaccharide further confirmed biofilm formation. In accordance, biofilm formation was susceptible to dispersin B, a PGA hydrolase. Transcriptional profiles of A. pleuropneumoniae S4074 following growth in BHI-B, which allowed a robust biofilm formation, and in BHI-A, in which only a slight biofilm formation was observed, were compared. Genes such as tadC, tadD, genes with homology to autotransporter adhesins as well as genes pgaABC involved in PGA biosynthesis and genes involved in zinc transport were up-regulated after growth in BHI-B. Interestingly, biofilm formation was inhibited by zinc, which was found to be more present in BHI-A (no or slight biofilm) than in BHI-B. We also observed biofilm formation in reference strains representing serotypes 3, 4, 5a, 12 and 14 as well as in 20 of the 37 fresh field isolates tested. Our data indicate that A. pleuropneumoniae has the ability to form biofilms under appropriate growth conditions and transition from a biofilm-positive to a biofilm-negative phenotype was reversible. PMID:19737507

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

    PubMed

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

    2015-01-01

    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.

  19. Growth conditions influence the melatonin content of tomato plants.

    PubMed

    Arnao, Marino Bañón; Hernández-Ruiz, Josefa

    2013-06-01

    Melatonin (N-acetyl-5-methoxytryptamine) is an interesting molecule with well-known functions in vertebrates. Since its discovery in plants in 1995, many data indicate that its role as a cellular antioxidant is very relevant. Agents that induce stress cause increased melatonin levels in plant organs and melatonin levels fluctuate over the light:dark cycle; there are also conflicting data on the influence of environmental conditions on the melatonin content of plants. In this contribution we describe how cultivation conditions decisively influence melatonin levels in roots, stems and leaves of tomato plants, and we establish some guidelines for interpreting data with the intention of opening up new discussion options, given the lack of data on the place/s of melatonin biosynthesis and its mode of action in plant cells as an antioxidant.

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

    PubMed

    Kim, Minseung; Zorraquino, Violeta; Tagkopoulos, Ilias

    2015-03-01

    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.

  1. Human STEAP3 maintains tumor growth under hypoferric condition

    SciTech Connect

    Isobe, Taichi; Baba, Eishi; Arita, Shuji; Komoda, Masato; Tamura, Shingo; Shirakawa, Tsuyoshi; Ariyama, Hiroshi; Takaishi, Shigeo; Kusaba, Hitoshi; and others

    2011-11-01

    Iron is essential in cellular proliferation and survival based on its crucial roles in DNA and ATP synthesis. Tumor cells proliferate rapidly even in patients with low serum iron, although their actual mechanisms are not well known. To elucidate molecular mechanisms of efficient tumor progression under the hypoferric condition, we studied the roles of six-transmembrane epithelial antigen of the prostate family member 3 (STEAP3), which was reported to facilitate iron uptake. Using Raji cells with low STEAP3 mRNA expression, human STEAP3-overexpressing cells were established. The impact of STEAP3 expression was analyzed about the amount of iron storage, the survival under hypoferric conditions in vitro and the growth of tumor in vivo. STEAP3 overexpression increased ferritin, an indicator of iron storage, in STEAP3-overexpressing Raji cells. STEAP3 gave Raji cells the resistance to iron deprivation-induced apoptosis. These STEAP3-overexpressing Raji cells preserved efficient growth even in hypoferric mice, while parental Raji cells grew less rapidly. In addition, iron deficiency enhanced STEAP3 mRNA expression in tumor cells. Furthermore, human colorectal cancer tissues exhibited more STEAP3 mRNA expression and iron storage compared with normal colon mucosa. These findings indicate that STEAP3 maintains iron storage in human malignant cells and tumor proliferation under the hypoferric condition. -- Highlights: {yields} STEAP3 expression results in increment of stored intracellular iron. {yields} Iron deprivation induces expression of STEAP3. {yields} Colorectal cancer expresses STEAP3 highly and stores iron much. {yields} STEAP3 expressing tumors preserves growth even in mice being hypoferremia.

  2. Modeling the Lag Period and Exponential Growth of Listeria monocytogenes under Conditions of Fluctuating Temperature and Water Activity Values▿

    PubMed Central

    Muñoz-Cuevas, Marina; Fernández, Pablo S.; George, Susan; Pin, Carmen

    2010-01-01

    The dynamic model for the growth of a bacterial population described by Baranyi and Roberts (J. Baranyi and T. A. Roberts, Int. J. Food Microbiol. 23:277-294, 1994) was applied to model the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity (aw) values. To model the duration of the lag phase, the dependence of the parameter h0, which quantifies the amount of work done during the lag period, on the previous and current environmental conditions was determined experimentally. This parameter depended not only on the magnitude of the change between the previous and current environmental conditions but also on the current growth conditions. In an exponentially growing population, any change in the environment requiring a certain amount of work to adapt to the new conditions initiated a lag period that lasted until that work was finished. Observations for several scenarios in which exponential growth was halted by a sudden change in the temperature and/or aw were in good agreement with predictions. When a population already in a lag period was subjected to environmental fluctuations, the system was reset with a new lag phase. The work to be done during the new lag phase was estimated to be the workload due to the environmental change plus the unfinished workload from the uncompleted previous lag phase. PMID:20208022

  3. Modeling the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity values.

    PubMed

    Muñoz-Cuevas, Marina; Fernández, Pablo S; George, Susan; Pin, Carmen

    2010-05-01

    The dynamic model for the growth of a bacterial population described by Baranyi and Roberts (J. Baranyi and T. A. Roberts, Int. J. Food Microbiol. 23:277-294, 1994) was applied to model the lag period and exponential growth of Listeria monocytogenes under conditions of fluctuating temperature and water activity (a(w)) values. To model the duration of the lag phase, the dependence of the parameter h(0), which quantifies the amount of work done during the lag period, on the previous and current environmental conditions was determined experimentally. This parameter depended not only on the magnitude of the change between the previous and current environmental conditions but also on the current growth conditions. In an exponentially growing population, any change in the environment requiring a certain amount of work to adapt to the new conditions initiated a lag period that lasted until that work was finished. Observations for several scenarios in which exponential growth was halted by a sudden change in the temperature and/or a(w) were in good agreement with predictions. When a population already in a lag period was subjected to environmental fluctuations, the system was reset with a new lag phase. The work to be done during the new lag phase was estimated to be the workload due to the environmental change plus the unfinished workload from the uncompleted previous lag phase.

  4. Integrating physiological and biomechanical drivers of population growth over environmental gradients on coral reefs.

    PubMed

    Madin, Joshua S; Hoogenboom, Mia O; Connolly, Sean R

    2012-03-15

    Coral reefs exhibit marked spatial and temporal variability, and coral reef organisms exhibit trade-offs in functional traits that influence demographic performance under different combinations of abiotic environmental conditions. In many systems, trait trade-offs are modelled using an energy and/or nutrient allocation framework. However, on coral reefs, differences in biomechanical vulnerability have major demographic implications, and indeed are believed to play an essential role in mediating species coexistence because highly competitive growth forms are vulnerable to physical dislodgment events that occur with high frequency (e.g. annual summer storms). Therefore, an integrated energy allocation and biomechanics framework is required to understand the effect of physical environmental gradients on species' demographic performance. However, on coral reefs, as in most ecosystems, the effects of environmental conditions on organisms are measured in different currencies (e.g. lipid accumulation, survival and number of gametes), and thus the relative contributions of these effects to overall capacity for population growth are not readily apparent. A comprehensive assessment of links between the environment and the organism, including those mediated by biomechanical processes, must convert environmental effects on individual-level performance (e.g. survival, growth and reproduction) into a common currency that is relevant to the capacity to contribute to population growth. We outline such an approach by considering the population-level performance of scleractinian reef corals over a hydrodynamic gradient, with a focus on the integrating the biomechanical determinants of size-dependent coral colony dislodgment as a function of flow, with the effects of flow on photosynthetic energy acquisition and respiration.

  5. Evaluation of Diesel Exhaust Continuous Monitors in Controlled Environmental Conditions

    PubMed Central

    Yu, Chang Ho; Patton, Allison P.; Zhang, Andrew; Fanac, Zhi-Hua (Tina); Weisel, Clifford P.; Lioy, Paul J.

    2015-01-01

    Diesel exhaust (DE) contains a variety of toxic air pollutants, including diesel particulate matter (DPM) and gaseous contaminants (e.g., carbon monoxide (CO)). DPM is dominated by fine (PM2.5) and ultrafine particles (UFP), and can be representatively determined by its thermal-optical refractory as elemental carbon (EC) or light-absorbing characteristics as black carbon (BC). The currently accepted reference method for sampling and analysis of occupational exposure to DPM is the National Institute for Occupational Safety and Health (NIOSH) Method 5040. However, this method cannot provide in-situ short-term measurements of DPM. Thus, real-time monitors are gaining attention to better examine DE exposures in occupational settings. However, real-time monitors are subject to changing environmental conditions. Field measurements have reported interferences in optical sensors and subsequent real-time readings, under conditions of high humidity and abrupt temperature changes. To begin dealing with these issues, we completed a controlled study to evaluate five real-time monitors: Airtec real-time DPM/EC Monitor, TSI SidePak Personal Aerosol Monitor AM510 (PM2.5), TSI Condensation Particle Counter 3007, microAeth AE51 BC Aethalometer, and Langan T15n CO Measurer. Tests were conducted under different temperatures (55, 70, and 80 °F), relative humidity (10, 40, and 80%), and DPM concentrations (50 and 200 µg/m3) in a controlled exposure facility. The 2-hour averaged EC measurements from the Airtec instrument showed relatively good agreement with NIOSH Method 5040 (R2=0.84; slope=1.17±0.06; N=27) and reported ~17% higher EC concentrations than the NIOSH reference method. Temperature, relative humidity, and DPM levels did not significantly affect relative differences in 2-hour averaged EC concentrations obtained by the Airtec instrument versus the NIOSH method (p<0.05). Multiple linear regression analyses, based on 1-min averaged data, suggested combined effects of up to 5

  6. The first "space" vegetables have been grown in the "SVET" greenhouse using controlled environmental conditions

    NASA Astrophysics Data System (ADS)

    Ivanova, T. N.; Bercovich, Yu. A.; Mashinskiy, A. L.; Meleshko, G. I.

    The paper describes the "SVET" project—a new generation of space greenhouse with small dimensions. Through the use of a minicomputer, "SVET" is fully capable of automatically operating and controlling environmental systems for higher plant growth. A number of preliminary studies have shown the radish and cabbage to be potentially important crops for CELSS (Closed Environmental Life Support System). The "SVET" space greenhouse was mounted on the "CRYSTAL" technological module docked to the Mir orbital space station on 10 June 1990. Soviet cosmonauts Balandin and Solovyov started the first experiments with the greenhouse on 15 June 1990. Preliminary results of seed cultivation over an initial 54-day period in "SVET" are presented. Morphometrical characteristics of plants brought back to Earth are given. Alteration in plant characteristics, such as growth and developmental changes, or morphological contents were noted. A crop of radish plants was harvested under microgravity conditions. Characteristics of plant environmental control parameters and an estimation of functional properties of control and regulation systems of the "SVET" greenhouse in space flight as received via telemetry data is reported.

  7. Bacterial populations growth under co- and counter-flow condition

    NASA Astrophysics Data System (ADS)

    Tesser, Francesca; Zeegers, Jos C. H.; Clercx, Herman J. H.; Toschi, Federico

    2014-11-01

    For organisms living in a liquid ecosystem, flow and flow gradients play a major role on the population level: the flow has a dual role as it transports the nutrient while dispersing the individuals. In absence of flow and under homogeneous conditions, the growth of a population towards an empty region is usually described by a reaction diffusion equation. The solution predicts the expansion as a wave front (Fisher wave) proceeding at constant speed, till the carrying capacity is reached everywhere. The effect of fluid flow, however, is not well understood and the interplay between transport of individuals and nutrient opens a wide scenario of possible behaviors. In this work, we experimentally observe non-motile E. coli bacteria spreading inside rectangular channels in a PDMS microfluidic device. By use of a fluorescent microscope we analyze the dynamics of the population density subjected to different co- and counter-flow conditions and shear rates.

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

    PubMed Central

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

    2014-01-01

    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

  9. Barnacles - recorders of environmental conditions with unique geochemical signatures

    NASA Astrophysics Data System (ADS)

    Vinzenz Ullmann, Clemens; Gale, Andy; Korte, Christoph; Frei, Robert; Huggett, Jenny; Wray, Dave

    2017-04-01

    Barnacles are calcite-forming arthropods that occur in a wide range of habitats in modern times and are found in sedimentary successions reaching back to the Paleozoic. Despite potential use of their mostly low-Mg calcite hard parts for palaeoenvironmental reconstructions, their geochemical composition has been little studied. Here, we present the first comprehensive overview of barnacle geochemistry, with C and O isotope, as well as Mg/Ca, Sr/Ca, Mn/Ca and Fe/Ca data for multiple samples of 42 species covering the orders Sessilia, Scalpelliformes, and Lepadiformes. XRD analyses confirm calcite as the only significant carbonate mineral of the studied barnacle shell material. Apart from one species, median Mg/Ca ratios fall below 50 mmol/mol, the approximate limit for low-Mg-calcite. In the order Sessilia, the scuta and terga are on average enriched in Mg by 36 % over the unmoveable plates. Amongst the calcite-forming marine animals, barnacles have very high Sr/Ca ratios of 2.6 to 5.9 mmol/mol, amongst the highest known for calcite secreting animals. Mn/Ca and Fe/Ca ratios are commonly low and compatible with other modern shell calcite, but can be strongly enriched to > 1 mmol/mol in proximal habitats, particularly close to areas strongly affected by human activity. Carbon and oxygen isotope data indicate formation of the calcite in or near isotopic equilibrium with ambient water conditions. Apart from species showing δ18O values below 0 ‰ V-PDB, a negative correlation of oxygen isotope ratios with Sr/Ca ratios is observed, which may be related to metabolic activity. Compositional patterns in barnacle shell material, particularly high Sr concentrations and Mg distribution in shell plates of the Sessilia, point to a great potential of barnacles for high fidelity reconstruction of past seawater chemistry and environmental conditions complementary to other archives.

  10. Surface monitoring measurements of materials on environmental change conditions

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

  11. Environmental Conditions Determine the Course and Outcome of Phytoplankton Chytridiomycosis

    PubMed Central

    Haande, Sigrid; Molversmyr, Åge

    2015-01-01

    Chytrid fungi are highly potent parasites of phytoplankton. They are thought to force phytoplankton organisms into an evolutionary arms race with high population diversity as the outcome. The underlying selection regime is known as Red Queen dynamics. However, our study suggests a more complex picture for chytrid parasitism in the cyanobacterium Planktothrix. Laboratory experiments identified a “cold thermal refuge”, inside which Planktothrix can grow without chytrid infection. A field study in two Norwegian lakes underlined the ecological significance of this finding. The study utilized sediment DNA as a biological archive in combination with existing monitoring data. In one lake, temperature and light conditions forced Planktothrix outside the thermal refuge for most of the growing season. This probably resulted in Red Queen dynamics as suggested by a high parasitic pressure exerted by chytrids, an increase in Planktothrix genotype diversity over time, and a correlation between Planktothrix genotype diversity and duration of bloom events. In the second lake, a colder climate allowed Planktothrix to largely stay inside the thermal refuge. The parasitic pressure exerted by chytrids and Planktothrix genotype diversity remained low, indicating that Planktothrix successfully evaded the Red Queen dynamics. Episodic Planktothrix blooms were observed during spring and autumn circulation, in the metalimnion or under the ice. Interestingly, both lakes were dominated by the same or related Planktothrix genotypes. Taken together, our data suggest that, depending on environmental conditions, chytrid parasitism can impose distinct selection regimes on conspecific phytoplankton populations with similar genotype composition, causing these populations to behave and perhaps to evolve differently. PMID:26714010

  12. Rapid population growth and environmental degradation: ultimate versus proximate factors.

    PubMed

    Shaw, R P

    1989-01-01

    This philosophical review of 2 arguments about responsibility for and solutions to environmental degradation concludes that both sides are correct: the ultimate and the proximal causes. Ultimate causes of pollution are defined as the technology responsible for a given type of pollution, such as burning fossil fuel; proximate causes are defined as situation-specific factors confounding the problem, such as population density or rate of growth. Commoner and others argue that developed countries with low or negative population growth rates are responsible for 80% of world pollution, primarily in polluting technologies such as automobiles, power generation, plastics, pesticides, toxic wastes, garbage, warfaring, and nuclear weapons wastes. Distortionary policies also contribute; examples are agricultural trade protection, land mismanagement, urban bias in expenditures, and institutional rigidity., Poor nations are responsible for very little pollution because poverty allows little waste or expenditures for polluting, synthetic technologies. The proximal causes of pollution include numbers and rate of growth of populations responsible for the pollution. Since change in the ultimate cause of pollution remains out of reach, altering the numbers of polluters can make a difference. Predictions are made for proportions of the world's total waste production, assuming current 1.6 tons/capita for developed countries and 0.17 tons/capita for developing countries. If developing countries grow at current rates and become more wealthy, they will be emitting half the world's waste by 2025. ON the other hand, unsustainable population growth goes along with inadequate investment in human capital: education, health, employment, infrastructure. The solution is to improve farming technologies in the 117 non-self-sufficient countries, fund development in the most unsustainable enclaves of growing countries, break institutionalized socio-political rigidity in these enclaves, and focus on

  13. Effects of Drift Degradation on Environmental Conditions in Drifts

    NASA Astrophysics Data System (ADS)

    Manepally, C.; Fedors, R. W.; Adams, G. R.; Green, S. T.

    2003-12-01

    Drift degradation is anticipated to significantly influence the environment inside waste emplacement drifts at the proposed repository for high level waste at Yucca Mountain, Nevada. This poster presents the calculated effects of drift degradation on the waste package and drip shield temperatures. Natural backfilling caused by degradation of the fractured tuff wallrock may occur gradually throughout the repository drifts, with all drifts estimated to be backfilled within 1,000 years after closure. Model results indicate prominent increases in waste package and drip shield temperatures due to the insulating effect of the backfill material. An algorithm linking drift degradation to estimates of waste package and drip shield temperature will be presented. Components of the different in-drift heat-transfer processes-including, conduction, convection and thermal radiation-are analyzed for relative importance. The results indicate that thermal radiation and convection dominate the in-drift heat transfer in the absence of drift degradation effects. In the case where drift degradation created a natural backfill, conduction through the backfill was the dominant heat transfer process. Furthermore, sensitivity analyses showed that the in-drift temperatures were very sensitive to the assumed thermal properties of the natural backfill. Ongoing numerical modeling that incorporates hydrologic effects on environmental conditions will also be discussed. This poster is an independent product of the CNWRA and does not necessarily reflect the view or regulatory position of the U.S. Nuclear Regulatory Commission.

  14. Transport Across Chloroplast Membranes: Optimizing Photosynthesis for Adverse Environmental Conditions.

    PubMed

    Pottosin, Igor; Shabala, Sergey

    2016-03-07

    Chloroplasts are central to solar light harvesting and photosynthesis. Optimal chloroplast functioning is vitally dependent on a very intensive traffic of metabolites and ions between the cytosol and stroma, and should be attuned for adverse environmental conditions. This is achieved by an orchestrated regulation of a variety of transport systems located at chloroplast membranes such as porines, solute channels, ion-specific cation and anion channels, and various primary and secondary active transport systems. In this review we describe the molecular nature and functional properties of the inner and outer envelope and thylakoid membrane channels and transporters. We then discuss how their orchestrated regulation affects thylakoid structure, electron transport and excitation energy transfer, proton-motive force partition, ion homeostasis, stromal pH regulation, and volume regulation. We link the activity of key cation and anion transport systems with stress-specific signaling processes in chloroplasts, and discuss how these signals interact with the signals generated in other organelles to optimize the cell performance, with a special emphasis on Ca(2+) and reactive oxygen species signaling. Copyright © 2016 The Author. Published by Elsevier Inc. All rights reserved.

  15. Age at menarche: the influence of environmental conditions

    NASA Astrophysics Data System (ADS)

    Saar, E.; Shalev, C.; Dalal, I.; Sod-Moriah, U. A.

    1988-03-01

    Age at menarche was studied by the recollection method in two groups of Causasian Jewish high school girls, inhabitants of two towns in Israel, Safad and Elat. The two towns differ mainly in climatic conditions. The age at menarche was found to be significantly lower ( P<0.02) in the hot town of Elat than in the temperate town of Safad: 13.30±1.21 and 13.58±0.9 years, respectively (mean ±SD). A significant association was found between the age at menarche and the town in which the girls lived. Accordingly, in the hot town of Elat, the percentage of girls who had their first menstrual cycle by the age of 12 years and earlier, was more than double that of the girls in Safad (17.9% and 7.1%, respectively). It is concluded that the environmental temperature, with or without any possible interaction of humidity, is probably responsible for the tendency for an earlier onset of menarche in girls living in the hot town of Elat.

  16. Do Environmental Conditions Contribute to Narcosis Onset and Symptom Severity?

    PubMed

    Lafère, P; Balestra, C; Hemelryck, W; Guerrero, F; Germonpré, P

    2016-12-01

    Although many factors contributing to inert gas narcosis onset and severity have been put forward, the available evidence is not particularly strong. Using objective criteria, we have assessed brain impairment associated with narcosis under various environmental diving conditions. 40 volunteers performed a no-decompression dive (33 m for 20 min) either in a dry chamber, a pool or open sea. They were assessed by critical flicker fusion frequency before the dive, upon arriving at depth, 5 min before ascent, on surfacing and 30 min post-dive. Compared to the pre-dive value, the mean value of each measurement was significantly different. An increase of flicker fusion to 105.00±0.69% when arriving at depth is followed by a decrease to 94.05±0.65%. This impairment persists when surfacing and 30 min post-dive, decreasing further to 96.36±0.73% and 96.24±0.73%, respectively. Intragroup comparison failed to demonstrate any statistical difference. When objectively measured narcosis may not be influenced by external factors other than pressure and gas. This might be of importance for training to avoid any over- or underestimation of the severity of narcosis based only on subjective symptoms.

  17. Azospirillum improves lettuce growth and transplant under saline conditions.

    PubMed

    Fasciglione, Gabriela; Casanovas, Elda M; Yommi, Alejandra; Sueldo, Rolando J; Barassi, Carlos A

    2012-09-01

    Recent studies have shown that as a plant-growth-promoting rhizobacteria (PGPR), Azospirillum inoculation could contribute to the mitigation of the negative effects caused by salt on lettuce growth. Moreover, the use of PGPR to alleviate the effects of transplant in vegetables has also been recognized. However, the scarce data available on the use of Azospirillum to improve lettuce growth before and after transplant under saline conditions prompted us to focus our research on this topic. Early germination and seedling settlement of seeds exposed to 0 and 40 mol m(-3) NaCl were clearly improved by Azospirillum inoculation. At 0 mol m(-3) NaCl, plant establishment, leaf mass and root mass parameters before transplant were significantly higher in inoculated plants than in non-inoculated controls. At harvest, leaf fresh weight, ascorbic acid content and plant survival to transplant were also significantly higher in Azospirillum-inoculated plants grown at 0 mol m(-3) NaCl. In addition to these effects, leaf dry weight, area and chlorophyll content were also increased by Azospirillum inoculation when plants were grown at 40 mol m(-3) NaCl. Azospirillum-inoculated lettuce seeds yield a higher number of transplanted plants with superior quality than non-inoculated controls grown at 0 or at 40 mol m(-3) NaCl. Copyright © 2012 Society of Chemical Industry.

  18. Conditioned medium from neural stem cells inhibits glioma cell growth.

    PubMed

    Li, Z; Zhong, Q; Liu, H; Liu, P; Wu, J; Ma, D; Chen, X; Yang, X

    2016-10-31

    Malignant glioma is one of the most common brain tumors in the central nervous system. Although the significant progress has been made in recent years, the mortality is still high and 5-year survival rate is still very low. One of the leading causes to the high mortality for glioma patients is metastasis and invasion. An efficient method to control the tumor metastasis is a promising way to treat the glioma. Previous reports indicated that neural stem cells (NSCs) were served as a delivery vector to the anti-glioma therapy. Here, we used the conditioned medium from rat NSCs (NSC-CM) to culture the human glioblastoma cell lines. We found that NSC-CM could inhibit the glioma cell growth, invasion and migration in vitro and attenuate the tumor growth in vivo. Furthermore, this anti-glioma effect was mediated by the inactivation of mitogen activated protein kinase (MAPK) pathway. Above all, this study provided the direct evidence to put forward a simple and efficient method in the inhibition of glioma cells/tumor growth, potentially advancing the anti-glioma therapy.

  19. Simulation of fatigue crack growth under large scale yielding conditions

    NASA Astrophysics Data System (ADS)

    Schweizer, Christoph; Seifert, Thomas; Riedel, Hermann

    2010-07-01

    A simple mechanism based model for fatigue crack growth assumes a linear correlation between the cyclic crack-tip opening displacement (ΔCTOD) and the crack growth increment (da/dN). The objective of this work is to compare analytical estimates of ΔCTOD with results of numerical calculations under large scale yielding conditions and to verify the physical basis of the model by comparing the predicted and the measured evolution of the crack length in a 10%-chromium-steel. The material is described by a rate independent cyclic plasticity model with power-law hardening and Masing behavior. During the tension-going part of the cycle, nodes at the crack-tip are released such that the crack growth increment corresponds approximately to the crack-tip opening. The finite element analysis performed in ABAQUS is continued for so many cycles until a stabilized value of ΔCTOD is reached. The analytical model contains an interpolation formula for the J-integral, which is generalized to account for cyclic loading and crack closure. Both simulated and estimated ΔCTOD are reasonably consistent. The predicted crack length evolution is found to be in good agreement with the behavior of microcracks observed in a 10%-chromium steel.

  20. Variations in Environmental Signals in Tree-Ring Indices in Trees with Different Growth Potential

    PubMed Central

    Hafner, Polona; Gričar, Jožica; Skudnik, Mitja; Levanič, Tom

    2015-01-01

    We analysed two groups of Quercus robur trees, growing at nearby plots with different micro-location condition (W-wet and D-dry) in the floodplain Krakovo forest, Slovenia. In the study we compared the growth response of two different tree groups to environmental variables, the potential signal stored in earlywood (EW) structure and the potential difference of the information stored in carbon isotope discrimination of EW and latewood (LW). For that purpose EW and LW widths and carbon isotope discrimination for the period 1970–2008 AD were measured. EW and LW widths were measured on stained microscopic slides and chronologies were standardised using the ARSTAN program. α-cellulose was extracted from pooled EW and LW samples and homogenized samples were further analysed using an elemental analyser and IRMS. We discovered that W oaks grew significantly better over the whole analysed period. The difference between D and W oaks was significant in all analysed variables with the exception of stable carbon isotope discrimination in latewood. In W oaks, latewood widths correlated with summer (June to August) climatic variables, while carbon isotope discrimination was more connected to River Krka flow during the summer. EW discrimination correlated with summer and autumn River Krka flow of the previous year, while latewood discrimination correlated with flow during the current year. In the case of D oaks, the environmental signal appears to be vague, probably due to less favourable growth conditions resulting in markedly reduced increments. Our study revealed important differences in responses to environmental factors between the two oak groups of different physiological conditions that are preconditioned by environmental stress. Environmental information stored in tree-ring features may vary, even within the same forest stand, and largely depends on the micro-environment. Our analysis confirmed our assumptions that separate EW and LW analysis of widths and carbon

  1. Mechanical characterization of yeast cells: effects of growth conditions.

    PubMed

    Overbeck, A; Kampen, I; Kwade, A

    2015-10-01

    Industrial biotechnology uses microbiological cells to produce a wide range of products. While the organisms in question are well understood regarding their genetic and molecular properties, less is known about their mechanical properties. Previous work has established a testing procedure for single Saccharomyces cerevisiae cells using a Nanoindenter equipped with a Flat Punch probe, allowing the compression between two parallel surfaces. The resulting force-displacement curves clearly showed the bursting of the cells and served to determine characteristic values such as the bursting force, bursting energy and relative deformation. This study examined the mechanical characteristics of yeast cells under the influence of varying cultivation parameters, namely the pH value, temperature, aeration rate, stirrer speed and culture medium composition. It was observed that only temperature and medium composition showed significant effect on the mechanical properties of the cells. Higher temperatures during cultivation caused lower bursting forces and energies. Further analysis of the data showed that the mechanical characteristics of the cells were only influenced by parameters which also had an influence on the growth rate. In conclusion, higher growth rates result in a lower mechanical strength of the yeast cells. This study provides data on the influence of growth conditions on the mechanical properties of yeast cells. Single cell compression tests on Saccharomyces cerevisiae cells indicate that higher growth rates result in a lower mechanical strength of the cells. As in biotechnological processes mechanical degradation is often part of the downstream process to release the product from the micro-organisms, the knowledge about the mechanical properties of the cells is relevant for process optimization. © 2015 The Society for Applied Microbiology.

  2. The Impact of Environmental Light Intensity on Experimental Tumor Growth.

    PubMed

    Suckow, Mark A; Wolter, William R; Duffield, Giles E

    2017-09-01

    Cancer research requires for consistent models that minimize environmental variables. Within the typical laboratory animal housing facility, animals may be exposed to varying intensities of light as a result of cage type, cage position, light source, and other factors; however, studies evaluating the differential effect of light intensity during the light phase on tumor growth are lacking. The effect of cage face light intensity, as determined by cage rack position was evaluated with two tumor models using the C57Bl/6NHsd mouse and transplantable B16F10 melanoma cells or Lewis lung carcinoma (LLC) cells. Animals were housed in individually-ventilated cages placed at the top, middle, or bottom of the rack in a diagonal pattern so that the top cage was closest to the ceiling light source, and cage face light intensity was measured. Following a two-week acclimation period at the assigned cage position, animals were subcutaneously administered either 1.3×10(6) B16F10 melanoma cells or 2.5×10(5) Lewis lung carcinoma cells. Weights of excised tumors were measured following euthanasia 18 days (melanoma) or 21 days (LCC) after tumor cell administration. Cage face light intensity was significantly different depending on the location of the cage, with cages closest to the light source have the greatest intensity. Mean tumor weights were significantly less (p<0.001 for melanoma; p≤0.01 for LCC) in middle light intensity mice compared to high and low light intensity mice. The environmental light intensity to which experimental animals are exposed may vary markedly with cage location and can significantly influence experimental tumor growth, thus supporting the idea that light intensity should be controlled as an experimental variable for animals used in cancer research. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  3. 76 FR 6455 - Final Programmatic Environmental Impact Statement (PEIS) for the Growth, Realignment, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-04

    ... Department of the Army Final Programmatic Environmental Impact Statement (PEIS) for the Growth, Realignment... growth, realignment, and stationing of new and existing Army aviation assets. The proposed action..., indirect, and cumulative environmental effects of proposed CAB growth and realignment for each...

  4. EVALUATION OF FUNGAL GROWTH ON FIBERGLASS DUCT MATERIALS FOR VARIOUS MOISTURE, SOIL, USE, AND TEMPERATURE CONDITIONS (JOURNAL)

    EPA Science Inventory

    The paper gives results of a series of experiments, each lasing 6 weeks, conducted in static environmental chambers to assess some of the conditions that may impact the ability of a variety of fiberglass materials to support the growth of a fungus, Penicillium chrysogenum. (NOTE:...

  5. EVALUATION OF FUNGAL GROWTH ON FIBERGLASS DUCT MATERIALS FOR VARIOUS MOISTURE, SOIL, USE, AND TEMPERATURE CONDITIONS (JOURNAL)

    EPA Science Inventory

    The paper gives results of a series of experiments, each lasing 6 weeks, conducted in static environmental chambers to assess some of the conditions that may impact the ability of a variety of fiberglass materials to support the growth of a fungus, Penicillium chrysogenum. (NOTE:...

  6. Effect of environmental pH on enzyme activity and growth of Bacteroides gingivalis W50.

    PubMed Central

    McDermid, A S; McKee, A S; Marsh, P D

    1988-01-01

    Since the pH of the gingival crevice increases from below neutrality in health to above pH 8 in disease, we decided to investigate the effect of environmental pH on the growth and enzyme activity of Bacteroides gingivalis W50. Cells were grown in a chemostat under hemin-excess conditions over a range of pH values; stable growth was observed only between pH 6.7 and 8.3, with the maximum yields obtained between pH 7.0 and 8.0. The enzyme profile of cells varied markedly with pH. Enzymes with a specificity for gingival connective tissue (collagenase, hyaluronidase) were produced optimally at or below neutral pH, whereas trypsinlike activity increased with the growth pH and was maximal at pH 8.0. Chymotrypsinlike activity was generally low, although its activity was highest at the extremes of growth pH, i.e., at pH 6.7 and 8.3. Inhibitor studies provided evidence that the breakdown of collagen involved the concerted action of both a collagenase and the trypsinlike enzyme. The ratio of trypsin to collagenolytic activity rose from 1:1 during growth at neutral pH and below to almost 7:1 during growth at pH 8.3. Thus B. gingivalis appears to be uniquely adapted as a periodontopathic organism in that under environmental conditions likely to prevail during the initial stages of pocket development it produces maximally those enzymes with a tissue-damaging potential. Then, as the pH of the pocket rises during the host inflammatory response, the activity of the trypsinlike enzyme increases markedly, which may enable cells to inactivate key components of the host defenses such as immunoglobulins and complement. PMID:3281900

  7. Reproductive health, population growth, economic development and environmental change.

    PubMed

    Lincoln, D W

    1993-01-01

    World population will increase by 1000 million, or by 20%, within 10 years. Ninety-five per cent of this increase will occur in the South, in areas that are already economically, environmentally and politically fragile. Morbidity and mortality associated with reproduction will be greater in the current decade than in any period in human history. Annually, 40-60 million pregnancies will be terminated and 5-10 million children will die within one year of birth. AIDS-related infections, e.g. tuberculosis, will undermine health care in Africa (and elsewhere) and in places AIDS-related deaths will decimate the work-force. The growth in population and associated morbidity will inhibit global economic development and spawn new problems. The key issues are migration, the spread of disease, the supply of water and the degradation of land, and fiscal policies with respect to family planning, pharmaceuticals and Third-World debt. Full education, particularly of women, and more effective family planning in the South have the power to unlock the problem. Failure will see the developed countries, with their 800 million population, swamped by the health, economic and environmental problems of the South, with its projected population of 5400 million people for the year 2000.

  8. Seed storage conditions change the germination pattern of clonal growth plants in Mediterranean salt marshes

    USGS Publications Warehouse

    Espinar, J.L.; Garcia, L.V.; Clemente, L.

    2005-01-01

    The effect of salinity level and extended exposure to different salinity and flooding conditions on germination patterns of three saltmarsh clonal growth plants (Juncus subulatus, Scirpus litoralis, and S. maritimus) was studied. Seed exposure to extended flooding and saline conditions significantly affected the outcome of the germination process in a different, though predictable, way for each species, after favorable conditions for germination were restored. Tolerance of the germination process was related to the average salinity level measured during the growth/germination season at sites where established individuals of each species dominated the species cover. No relationship was found between salinity tolerance of the germination process and seed response to extended exposure to flooding and salinity conditions. The salinity response was significantly related to the conditions prevailing in the habitats of the respective species during the unfavorable (nongrowth/nongermination) season. Our results indicate that changes in salinity and hydrology while seeds are dormant affect the outcome of the seed-bank response, even when conditions at germination are identical. Because these environmental-history-dependent responses differentially affect seed germination, seedling density, and probably sexual recruitment in the studied and related species, these influences should be considered for wetland restoration and management.

  9. Genome sequence analysis of Pseudomonas extremaustralis provides new insights into environmental adaptability and extreme conditions resistance.

    PubMed

    Raiger Iustman, Laura J; Tribelli, Paula M; Ibarra, José G; Catone, Mariela V; Solar Venero, Esmeralda C; López, Nancy I

    2015-01-01

    The genome of the Antarctic bacterium Pseudomonas extremaustralis was analyzed searching for genes involved in environmental adaptability focusing on anaerobic metabolism, osmoregulation, cold adaptation, exopolysaccharide production and degradation of complex compounds. Experimental evidences demonstrated the functionality of several of these pathways, including arginine and pyruvate fermentation, alginate production and growth under cold conditions. Phylogenetic analysis along with genomic island prediction allowed the detection of genes with probable foreign origin such as those coding for acetate kinase, osmotic resistance and colanic acid biosynthesis. These findings suggest that in P. extremaustralis the horizontal transfer events and/or gene redundancy could play a key role in the survival under unfavorable conditions. Comparative genome analysis of these traits in other representative Pseudomonas species highlighted several similarities and differences with this extremophile bacterium.

  10. Use of response surface methodology to optimise environmental stress conditions on Penicillium glabrum, a food spoilage mould.

    PubMed

    Nevarez, Laurent; Vasseur, Valérie; Debaets, Stella; Barbier, Georges

    2010-01-01

    Fungi are ubiquitous microorganisms often associated with spoilage and biodeterioration of a large variety of foods and feedstuffs. Their growth may be influenced by temporary changes in intrinsic or environmental factors such as temperature, water activity, pH, preservatives, atmosphere composition, all of which may represent potential sources of stress. Molecular-based analyses of their physiological responses to environmental conditions would help to better manage the risk of alteration and potential toxicity of food products. However, before investigating molecular stress responses, appropriate experimental stress conditions must be precisely defined. Penicillium glabrum is a filamentous fungus widely present in the environment and frequently isolated in the food processing industry as a contaminant of numerous products. Using response surface methodology, the present study evaluated the influence of two environmental factors (temperature and pH) on P. glabrum growth to determine 'optimised' environmental stress conditions. For thermal and pH shocks, a large range of conditions was applied by varying factor intensity and exposure time according to a two-factorial central composite design. Temperature and exposure duration varied from 30 to 50 °C and from 10 min to 230 min, respectively. The effects of interaction between both variables were observed on fungal growth. For pH, the duration of exposure, from 10 to 230 min, had no significant effect on fungal growth. Experiments were thus carried out on a range of pH from 0.15 to 12.50 for a single exposure time of 240 min. Based on fungal growth results, a thermal shock of 120 min at 40 °C or a pH shock of 240 min at 1.50 or 9.00 may therefore be useful to investigate stress responses to non-optimal conditions.

  11. Factors Conditioning Community Utilization of Environmental Education in Tanzania: The Case of Uluguru Mountains, Morogoro Municipality

    ERIC Educational Resources Information Center

    Manase, Joseph

    2016-01-01

    In order for the community to bring meaningful and sustainable environmental conservation and change, it must take action in implementing environmental education values acquired from environmental learning programmes and organizations. This study therefore aimed at assessing factors conditioning community implementation of environmental education…

  12. Race, Social and Environmental Conditions, and Health Behaviors in Men

    PubMed Central

    Thorpe, Roland J.; Kennedy-Hendricks, Alene; Griffith, Derek M.; Bruce, Marino A.; Coa, Kisha; Bell, Caryn N.; Young, Jessica; Bowie, Janice V.; LaVeist, Thomas A.

    2016-01-01

    Although understanding race differences in health behaviors among men is an important step in reducing disparities in leading causes of death in the United States, progress has been stifled when using national data because of the confounding of race, socioeconomic status (SES), and residential segregation. The purpose of this study is to examine the nature of disparities in health behaviors among African American and White men in the Exploring Health Disparities in Integrated Communities Study-Southwest Baltimore (EHDIC-SWB) which was conducted in a racially a racially-integrated neighborhood of Baltimore to data from the 2003 National Health Interview Survey (NHIS). After adjusting for age, marital status, insurance, income, educational attainment, poor or fair health, and obesity status, African American men in NHIS had greater odds of being physically inactive (odds ratio [OR] =1.48, 95% confidence interval [CI] 129, 1.69), reduced odds of being a current smoker (OR= 0.77, 95% CI 0.65, 0.90), and reduced odds of being a current drinker (OR= 0.58, 95% CI 0.50, 0.67). In the EHDIC-SWB sample, African American and white men had similar odds of being physically inactive (OR = 0.79, 95% CI 0.50, 1.24), being a current smoker (OR = 0.86, 95% CI 0.60, 1.23), or being a current drinker (OR = 1.34, 95% CI 0.81, 2.21). Because race disparities in these health behaviors were ameliorated in the sample where African American and white men were living under similar social, environmental and SES conditions, these findings suggest that social environment may be an important determinant of health behaviors among African American and White men. Public health interventions and health promotion strategies should consider the social environment when seeking to better understand men’s health disparities. PMID:26291190

  13. Prediction of glass durability as a function of environmental conditions

    SciTech Connect

    Jantzen, C M

    1988-01-01

    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.

  14. Race, Social and Environmental Conditions, and Health Behaviors in Men.

    PubMed

    Thorpe, Roland J; Kennedy-Hendricks, Alene; Griffith, Derek M; Bruce, Marino A; Coa, Kisha; Bell, Caryn N; Young, Jessica; Bowie, Janice V; LaVeist, Thomas A

    2015-01-01

    Although understanding race differences in health behaviors among men is an important step in reducing disparities in leading causes of death in the United States, progress has been stifled when using national data because of the confounding of race, socioeconomic status, and residential segregation. The purpose of this study is to examine the nature of disparities in health behaviors among African American and white men in the Exploring Health Disparities in Integrated Communities Study-Southwest Baltimore, which was conducted in a racially integrated neighborhood of Baltimore to data from the 2003 National Health Interview Survey. After adjusting for age, marital status, insurance, income, educational attainment, poor or fair health, and obesity status, African American men in National Health Interview Survey had greater odds of being physically inactive (odds ratio [OR] = 1.48; 95% confidence interval [CI], 129-1.69), reduced odds of being a current smoker (OR = 0.77; 95% CI, 0.65-0.90), and reduced odds of being a current drinker (OR = 0.58; 95% CI, 0.50-0.67). In the Exploring Health Disparities in Integrated Communities Study-Southwest Baltimore sample, African American and white men had similar odds of being physically inactive (OR = 0.79; 95% CI, 0.50-1.24), being a current smoker (OR = 0.86; 95% CI, 0.60-1.23), or being a current drinker (OR = 1.34; 95% CI, 0.81-2.21). Because race disparities in these health behaviors were ameliorated in the sample where African American and white men were living under similar social, environmental, and socioeconomic status conditions, these findings suggest that social environment may be an important determinant of health behaviors among African American and white men. Public health interventions and health promotion strategies should consider the social environment when seeking to better understand men's health disparities.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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

  16. Cytokine and Growth Factor Concentrations in Canine Autologous Conditioned Serum.

    PubMed

    Sawyere, Dominique M; Lanz, Otto I; Dahlgren, Linda A; Barry, Sabrina L; Nichols, Anne C; Werre, Stephen R

    2016-07-01

    To compare cytokine and growth factor concentrations in canine autologous conditioned serum (ACS) to canine plasma. Experimental in vivo study. Client-owned, adult dogs (n=22). Blood collected from 16 medium to large breed dogs was used to produce ACS (Orthokine(®) vet irap 10 syringes) and citrated plasma (control). Canine-specific ELISA assays were run per manufacturers' instructions for interleukin (IL)-10, IL-4, tumor necrosis factor (TNF)-α, insulin-like growth factor (IGF)-1, fibroblast growth factor (FGF)-2, transforming growth factor (TGF)-β1, IL-1β, and interleukin-1 receptor antagonist (IL-1ra). Serum, in addition to plasma and ACS, was collected from an additional 6 dogs for TNF-α, IL-1β, and IL-1ra analysis (total of 22 dogs). Data were analyzed for differences in each cytokine concentration using pairwise comparisons between ACS, plasma, and serum using Wilcoxon signed-rank tests. Significance was set at P<.05. There was a large variability in growth factor and cytokine concentrations in ACS and plasma for individual dogs. There were no significant differences in IL-10, TNF-α, IGF-1, FGF-2, and TGF-β1 concentrations between ACS, plasma, and serum. The IL-1β concentrations in ACS (median, range 46.3 pg/mL, 0-828.8) and IL-4 (0.0 pg/mL, 0-244.1) were significantly higher than plasma (36.6 pg/mL, 0-657.1 and 0.0 pg/mL, 0-0, respectively). The IL-1ra concentration in ACS (median, range 3,458.9 pg/mL, 1,243.1-12,089.0) was significantly higher than plasma (692.3 pg/mL, 422.5-1,475.6). The IL-1ra:IL-1β ratio in ACS was significantly higher than plasma (39.9 vs. 7.2). IL-1ra concentrations in canine ACS were comparable to those published for people and horses and pro-inflammatory cytokines remained low in canine ACS. © Copyright 2016 by The American College of Veterinary Surgeons.

  17. Growth of pulsed electric field exposed Escherichia coli in relation to inactivation and environmental factors.

    PubMed

    Aronsson, Kristina; Borch, Elisabeth; Stenlöf, Bo; Rönner, Ulf

    2004-05-15

    Pulsed electric fields (PEF) have been proven to inactivate microorganisms during nonthermal conditions and have the potential to replace thermal processing as a method for food preservation. However, there is a need to understand the recovery and growth of survivors and potentially injured microorganisms following PEF processing. The purpose of this investigation was to study the growth of Escherichia coli at 10 degrees C following exposure to electrical field strengths (15, 22.5 and 30 kV/cm) in relation to inactivation and the amount of potentially sublethally injured cells. One medium was used as both a treatment medium and an incubation medium, to study the influence of environmental factors on the inactivation and the growth of the surviving population. The pH (5.0, 6.0 and 7.0) and water activity (1.00, 0.985 and 0.97) of the medium was varied by adding HCl and glycerol, respectively. Growth was followed continuously by measuring the optical density. The time-to-detection (td) and the maximum specific growth rate (micromax) were calculated from these data. Results showed that the PEF process did not cause any obvious sublethal injury to the E. coli cells. The number of survivors was a consequence of the combination of electrical field strength and environmental factors, with pH being the most prominent. Interestingly, the micromax of subsequent growth was influenced by the applied electrical field strength during the process, with an increased micromax at more intense electrical field strengths. In addition, the micromax was also influenced by the pH and water activity. The td, which could theoretically be considered as an increase in shelf life, was found to depend on a complex correlation between electrical field strength, pH and water activity. That could be explained by the fact that the td is a combination of the number of survivors, the recovery of sublethal injured cells and the growth rate of the survivors.

  18. The onset condition of equatorial plasma bubbles - the role of seeding mechanism and growth condition

    NASA Astrophysics Data System (ADS)

    Kil, H.; Choi, J. M.; Kwak, Y. S.; Lee, W. K.; Park, J.

    2015-12-01

    We investigate the role of seeding mechanism and growth condition of perturbations in the creation of equatorial plasma bubbles by analyzing the C/NOFS and ROCSAT-1 satellite observations. The initial development times of bubbles were identified by manual processing of the data, and the periodic characteristics in the occurrence of bubbles were investigated using periodograms obtained from segments of bubble chains. Our preliminary results show that bubbles initiate at the time that the pre-reversal enhancement (PRE) ends. This time corresponds to the time that the F region reaches the highest altitude where the growth rate of the Rayleigh-Taylor (R-T) instability is large. The initial onset time of bubbles varies with season and longitude in accordance with the variation of the PRE ending time. Our investigation of the periodicity in the occurrence of bubbles (spacing between bubbles) shows that a dominant periodicity does not exist; the spacing between bubbles ranges from 100 km to over 1000 km. A pronounced periodicity occurs in some series of bubbles, but, in general, multiple periodicity co-exists. The initiation of bubbles at a specific local time but the absence of a preferential wave property in the occurrence of bubbles lead to the conclusion that the onset of bubbles is controlled by the growth condition of the R-T instability.

  19. Environmental degradation of polyacrylamides. 1. Effects of artificial environmental conditions: temperature, light, and pH.

    PubMed

    Smith, E A; Prues, S L; Oehme, F W

    1996-11-01

    A polyacrylamide thickening agent (PATA) was formulated at four concentrations in distilled-deionized water, without and with a glyphosate-surfactant herbicide (GH). Over a 6-week period, these mixtures were exposed to various controlled temperature and light conditions. Acrylamide concentration, ammonium concentration, and pH were measured at weekly intervals to assess the degradation of polyacrylamide and acrylamide. Satellite studies were conducted to examine the effect of altered pH on solutions of PATA (i.e., does pH promote polyacrylamide depolymerization?) and GH binding to amine groups (i.e., protection from degradation). The results of these studies suggest that polyacrylamide can degrade to acrylamide by thermal and photolytic effects, that changes in pH do not promote the depolymerization of polyacrylamide, and that GH does protect polyacrylamide and acrylamide from environmental degradation. Statistically there was no linear correlation between the various parameters measured.

  20. Measurement of microbial growth in the low nutrient conditions of a simulated subsurface environment

    NASA Astrophysics Data System (ADS)

    Hand, V. L.; Boult, S.; Vaughan, D. J.; Beadle, I. R.; Humphreys, P.; Wogelius, R. A.

    2003-04-01

    The growth of bacteria in natural porous media may alter porosity and permeability, and therefore hydraulic conductivity. Changes are due both to pore clogging caused by the production of bacterial extracellular polysaccharides (EPS) and the formation of secondary mineral precipitates. Pore clogging has implications not only for fluid flow, but also for contaminant transport. Most biofilm research has been conducted under nutrient rich conditions, quite different from the actual subsurface environment. There is therefore a general need for studies under environmentally relevant conditions. The main objectives were to determine growth under environmental conditions and to produce reproducible homogeneously coated columns of porous media for further experiments on metal transport. Six short columns (length 25mm; diameter 20mm) instrumented with pressure, pH and dissolved oxygen sensors were used. Growth and reproducibility of the biofilm are related to the flow rate, the concentration of the nutrients and the grain size of the porous medium substrate. Two types of porous media were used; a single mineral quartz media with a constant grain size and a natural mixed mineral assemblage of non-uniform grain size. Nutrient used was a landfill derived carbon source present in synthetic trench leachate (STL) diluted with synthetic groundwater (SGW) by a factor of 100. The STL was pumped through each column at a constant, environmentally relevant flow rate of 0.109 ml/min. Experiments were performed under both aerobic and anaerobic conditions contained in a temperature-controlled room at 10^oC. Measurement of the pressure increase within the column apparatus was made, as an increase in pressure is relative to the resistance of the media to flow and indicates biofilm formation and pore clogging within the column. Monitoring of dissolved oxygen shows the metabolic conditions of the bacteria and also the biological oxygen demand. Column effluent was analysed for changes in

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

    PubMed Central

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

    2011-01-01

    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

  2. Variation among species in proteomic sulphur content is related to environmental conditions

    PubMed Central

    Bragg, Jason G; Thomas, Dominique; Baudouin-Cornu, Peggy

    2006-01-01

    The elemental composition of proteins influences the quantities of different elements required by organisms. Here, we considered variation in the sulphur content of whole proteomes among 19 Archaea, 122 Eubacteria and 10 eukaryotes whose genomes have been fully sequenced. We found that different species vary greatly in the sulphur content of their proteins, and that average sulphur content of proteomes and genome base composition are related. Forces contributing to variation in proteomic sulphur content appear to operate quite uniformly across the proteins of different species. In particular, the sulphur content of orthologous proteins was frequently correlated with mean proteomic sulphur contents. Among prokaryotes, proteomic sulphur content tended to be greater in anaerobes, relative to non-anaerobes. Thermophiles tended to have lower proteomic sulphur content than non-thermophiles, consistent with the thermolability of cysteine and methionine residues. This work suggests that persistent environmental growth conditions can influence the evolution of elemental composition of whole proteomes in a manner that may have important implications for the amount of sulphur used by living organisms to build proteins. It extends previous studies that demonstrated links between transient changes in environmental conditions and the elemental composition of subsets of proteins expressed under these conditions. PMID:16720405

  3. Environmental Influences on the Release of Ophiosphaerella agrostis Ascospores Under Controlled and Field Conditions.

    PubMed

    Kaminski, John E; Dernoeden, Peter H; O'Neill, Nichole R

    2005-11-01

    ABSTRACT Ophiosphaerella agrostis, the causal agent of dead spot of creeping bentgrass (Agrostis stolonifera), can produce prodigious numbers of pseudothecia and ascospores throughout the summer. The environmental conditions and seasonal timings associated with O. agrostis ascospore release are unknown. The objectives of this research were to (i) determine the influence of light and relative humidity on ascospore release in a controlled environment, (ii) document the seasonal and daily discharge patterns of ascospores in the field, and (iii) elucidate environmental conditions that promote ascospore release under field conditions. In a growth chamber, a sharp decrease (100 to approximately 50%; 25 degrees C) in relative humidity resulted in a rapid (1- to 3-h) discharge of ascospores, regardless of whether pseudothecia were incubated in constant light or dark. In the field, daily ascospore release increased between 1900 and 2300 h and again between 0700 and 1000 h local time. The release of ascospores occurred primarily during the early morning hours when relative humidity was decreasing and the canopy began to dry, or during evening hours when relative humidity was low and dew began to form. Few ascospores were released between 1100 and 1800 h when the bentgrass canopy was dry. The release of ascospores also was triggered by precipitation. Of the ascospores collected during precipitation events, 87% occurred within 10 h of the beginning of each event.

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

    PubMed

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

    2011-11-22

    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.

  5. OVERALL MASS TRANSFER COEFFICIENT FOR POLLUTANT EMISSIONS FROM SMALL WATER POOLS UNDER SIMULATED INDOOR ENVIRONMENTAL CONDITIONS

    EPA Science Inventory

    Small chamber tests were conducted to experimentally determine the overall mass transfer coefficient for pollutant emissions from still water under simulated indoor-residential or occupational-environmental conditions. Fourteen tests were conducted in small environmental chambers...

  6. Raman spectroscopy of a single living cell in environmentally stressed conditions

    NASA Astrophysics Data System (ADS)

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

    2005-08-01

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

  7. Production of native arbuscular mycorrhizal fungi inoculum under different environmental conditions.

    PubMed

    Torres-Arias, Yamir; Fors, Rosalba Ortega; Nobre, Camila; Gómez, Eduardo Furrazola; Berbara, Ricardo Luis Louro

    In order to obtain an arbuscular mycorrhizal fungi (AMF) native inoculum from Sierra de Moa and determine the most appropriate conditions for its big scale production, four light and temperature combinations were tested in three plant species (Calophyllum antillanum, Talipariti elatum and Paspalum notatum). Growth and development parameters, as well as the mycorrhizal functioning of the seedlings were evaluated. The natural light treatment under high temperatures (L-H) was the most suitable for the growth and development of the three plant species, showing the highest total biomass values, mainly of root, and a positive root-shoot ratio balance. This treatment also promoted higher values of root mycorrhizal colonization, external mycelium and AMF spore density. A total of 38 AMF species were identified among the plants and environmental conditions tested. Archaeospora sp.1, Glomus sp.5, Glomus brohultii and G. glomerulatum were observed in all the treatments. The L-H condition can be recommended for native inoculum production, as it promotes a better expression of the AM symbiosis and an elevated production of mycorrhizal propagules. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

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

    SciTech Connect

    Al-Hedaithy, S.S.M.

    1983-01-01

    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.

  9. 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

    Feldman, Ruth; Eidelman, Arthur I.

    2009-01-01

    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…

  10. 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...

  11. Bacillus safensis with plant-derived smoke stimulates rice growth under saline conditions.

    PubMed

    Khan, Muhammad Hafeez Ullah; Khattak, Jabar Zaman Khan; Jamil, Muhammad; Malook, Ijaz; Khan, Shahid Ullah; Jan, Mehmood; Din, Ismail; Saud, Shah; Kamran, Muhammad; Alharby, Hesham; Fahad, Shah

    2017-09-03

    Salinity is a worldwide environmental problem of agricultural lands. Smoke and plant growth-promoting bacteria (PGPR) are individually used to improve plant growth, but the combined effects of these have not been studied yet under saline conditions. The combined effect of plant growth-promoting bacteria Bacillus safensis and plant-derived smoke Cymbopogon jwarancusa was studied under different salinity level as 50, 100, and 150 mM on rice (cv. Basmati-385). Smoke dilutions of C. jwarancusa (C-500 and C-1000) and bacterial culture of B. safensis were used to soak seeds for 10 h. It was observed that the salt concentration decreases the germination percentage, vegetative growth, ion contents (K(+) and Ca(2+)), and photosynthetic pigments (Chl "a," Chl "b," and carotene) while an increase occurred in Na(+), total soluble protein (TSP), proline, total soluble sugar, catalase (CAT), and peroxidase (POD) contents. The combined effect of B. safensis and smoke primed seeds increased the germination percentage, seedling growth, ion contents (K(+), Ca(2+)), and photosynthetic pigments (Chl "a," Chl "b," carotene) and reduced the Na(+) ion content, total soluble protein, proline content, total soluble sugar, CAT, and POD activity by lowering the drastic effect of salt stress. It was concluded that combined effect of smoke and PGPR is more effective than individual effect.

  12. Growth patterns for etiolated soybeans germinated under spaceflight conditions

    NASA Astrophysics Data System (ADS)

    Levine, Howard G.; Piastuch, William C.

    In the GENEX (GENe EXpression) spaceflight experiment (flown on STS-87), six surface sterilized soybean seeds ( Glycine max cv McCall) were inserted into each of 32 autoclaved plastic seed growth pouches containing an inner germination paper sleeve (for a total of 192 seeds). The pouches were stowed within a mid-deck locker until Mission Flight Day 10, at which time an astronaut added water to initiate the process of seed germination on-orbit and subsequently transferred them to four light-tight aluminum canisters called BRIC-60s (Biological Research In Canisters). We report here on the morphological characteristics of: (1) the recovered flight plants ( N = 177), (2) the corresponding ground control population ( N = 183), plus (3) additional controls grown on the ground under clinostat conditions ( N = 93). No significant morphological differences were found between the flight, ground control and clinorotated treatments for either the cotyledons or hypocotyls. There were, however, significantly longer primary roots produced in the flight population relative to the ground control population, which in turn had significantly longer primary roots than the clinorotated population. This same pattern was observed relative to the production of lateral roots (flight > control > clinorotated). Taken together with previous literature reports, we believe that there is now sufficient evidence to conclude that plants grown under conditions of microgravity will generally exhibit enhanced root production relative to their ground control counterparts. Some causes underlying this phenomenon are speculated on.

  13. Application of molluscan analyses to the reconstruction of past environmental conditions in estuaries: Chapter 15

    USGS Publications Warehouse

    Wingard, Georgiana L.; Surge, Donna

    2017-01-01

    Molluscs possess a number of attributes that make them an excellent source of past environmental conditions in estuaries: they are common in estuarine environments; they typically have hard shells and are usually well preserved in sediments; they are relatively easy to detect in the environment; they have limited mobility as adults; they grow by incremental addition of layers to their shells; and they are found in all the major environments surrounding estuaries—terrestrial, freshwater, brackish, and marine waters. Analysis of molluscan assemblages can contribute information about past changes in sea level, climate, land use patterns, anthropogenic alterations, salinity, and other parameters of the benthic habitat and water chemistry within the estuary. High-resolution (from less than a day to annual) records of changes in environmental parameters can be obtained by analyzing the incremental growth layers in mollusc shells (sclerochronology). The shell layers retain information on changes in water temperature, salinity, seasonality, climate, river discharge, productivity, pollution and human activity. Isotopic analyses of mollusc shell growth layers can be problematic in estuaries where water temperatures and isotopic ratios can vary simultaneously; however, methods are being developed to overcome these problems. In addition to sclerochronology, molluscs are important to Holocene and Pleistocene estuarine palaeoenvironmental studies because of their use in the development of age models through radiocarbon dating, amino acid racemization, uranium-thorium series dating, and electron spin resonance (ESR) dating.

  14. Escherichia coli growth and transport in the presence of nanosilver under variable growth conditions.

    PubMed

    Xie, Weijie; Vu, Kien; Yang, Guang; Tawfiq, Kamal; Chen, Gang

    2014-01-01

    Nanosilver (silver nanoparticles) has the ability to anchor to the bacterial cell membrane and subsequently penetrate it, thereby causing structural changes (i.e., permeability) in the cell membrane and death of the cell. The bacterial responses to the presence of nanosilver usually vary depending on the concentration of nanosilver particles, exposure time and the bacterial physiological stage. Since bacterial anabolism dependents upon a stoichiometric ratio of carbon and inorganic elements (nutrients), the macronutrient ratio, i.e. carbon to nitrogen ratio (C/N) thus plays an important role of bacterial responses to the exposure of nanosilver. This study investigated the responses of Escherichia coli to the exposure of nanosilver under variable growth conditions. It was discovered that E. coli grown under different growth conditions had different responses to the presence of nanosilver. E. coli had least resistance to the toxicity of nanosilver when cultured under carbon-limited conditions. However, the presence of rhamnolipid, a commonly utilized biosurfactant for soil remediation increased the resistance of E. coli to nanosilver. The transport of E. coli cultured under carbon-limited conditions was further studied in silica sand columns. E. coli adsorption in silica sand increased when cultured in the presence of nanosilver. On the contrary, E. coli adsorption in silica sand was significantly reduced when cultured in the presence of rhamnolipid.

  15. ECO and RESOLVE: Galaxy Disk Growth in Environmental Context

    NASA Astrophysics Data System (ADS)

    Moffett, Amanda J.; Kannappan, Sheila J.; Berlind, Andreas A.; Eckert, Kathleen D.; Stark, David V.; Hendel, David; Norris, Mark A.; Grogin, Norman A.

    2015-10-01

    We study the relationships between galaxy environments and galaxy properties related to disk (re)growth, considering two highly complete samples that are approximately baryonic mass limited into the high-mass dwarf galaxy regime, the Environmental COntext catalog (data release herein) and the B-semester region of the REsolved Spectroscopy Of a Local VolumE survey. We quantify galaxy environments using both group identification and smoothed galaxy density field methods. We use by-eye and quantitative morphological classifications plus atomic gas content measurements and estimates. We find that blue early-type (E/S0) galaxies, gas-dominated galaxies, and UV-bright disk host galaxies all become distinctly more common below group halo mass ˜ {10}11.5 {M}⊙ , implying that this low group halo mass regime may be a preferred regime for significant disk growth activity. We also find that blue early-type and blue late-type galaxies inhabit environments of similar group halo mass at fixed baryonic mass, consistent with a scenario in which blue early-types can regrow late-type disks. In fact, we find that the only significant difference in the typical group halo mass inhabited by different galaxy classes is for satellite galaxies with different colors, where at fixed baryonic mass red early- and late-types have higher typical group halo masses than blue early- and late-types. More generally, we argue that the traditional morphology-environment relation (i.e., that denser environments tend to have more early-types) can be largely attributed to the morphology-galaxy mass relation for centrals and the color-environment relation for satellites.

  16. Breed and environmental effects on postweaning growth of rabbits.

    PubMed

    McNitt, J I; Lukefahr, S D

    1993-08-01

    Growth records of 4,270 weanling rabbits born between March 1985 and December 1989 were studied to evaluate the effects of breed and month of birth on postweaning growth performance of four medium-sized breeds. Californian (CAL), New Zealand White (NZW), Palomino (PAL), and White Satin (WS). Traits examined were 28-d weaning weight (WW), postweaning gain (GAIN), attainment of 1,600-g market weight by 76 d of age (MKT), and approximate age at 1,600 g (AGE). Least squares models included breed, month of birth, sex, and year of birth as fixed effects and litter within breed by month and by year and the residual as random variables. The NZW had significantly higher GAIN and MKT and lower AGE than the other three breeds. White Satin had the highest WW, followed by CAL, NZW, and PAL. White Satin had higher GAIN and lower AGE than PAL or CAL but did not differ for MKT. Poorer performance was seen during the summer, but the NZW tended to be less affected by the environmental extremes than the other breeds. The effects on GAIN of mean monthly temperature and daylength and the interrelationships of these with estimated milk production and litter size at weaning were evaluated by regression methods for the 2,100 NZW fryers. Temperature and daylength had significant effects on GAIN, with lowest GAIN in the summer, but the individual contributions to the variance were small because of some redundancy when month, temperature, and (or) light were included in the same model. Curvilinear trends were observed that favored GAIN as estimated milk production increased but decreased GAIN as litter size at weaning increased. In the hot, humid climate of southern Louisiana important breed differences were noted. There were also indications that daylength may be an important factor in postweaning fryer performance.

  17. ECO and RESOLVE: Morphology and Disk Growth in Environmental Context

    NASA Astrophysics Data System (ADS)

    Moffett, Amanda J.; Kannappan, Sheila; Berlind, Andreas A.; Eckert, Kathleen D.; Stark, David; Hendel, David; Norris, Mark A.; Grogin, Norman A.; RESOLVE Team

    2016-01-01

    We present the first data release of the Environmental COntext (ECO) catalog, which was designed to surround and complement the RESOLVE survey with matched photometry, gas and stellar mass estimates, and environment metrics for ~13,000 galaxies in a >500,000 cubic Mpc volume. In the first results from ECO, we study the phenomenon of galaxy disk growth by considering by-eye and quantitative morphological classifications as well as galaxy environments quantified using group identifications and halo abundance matching (on integrated r-band luminosity) as well as smoothed galaxy density fields. Additionally, we derive HI gas masses and upper limits from ALFALFA data and HI mass estimates from the photometric gas fraction technique. We find that blue early-type (E/S0) galaxies, gas-dominated galaxies, and UV-bright disk host galaxies all become distinctly more common below group halo mass ˜10^11.5 Msun, implying that this low group halo mass regime may be a preferred regime for significant disk growth activity. We also find that blue early-type and blue late-type galaxies inhabit environments of similar group halo mass at fixed baryonic mass, consistent with a scenario in which blue early types can regrow late-type disks. More generally, we argue that the traditional morphology-environment relation (i.e., that denser environments have more early types) can be largely attributed to the morphology-galaxy mass relation for centrals and the color-environment relation for satellites. This work has been supported through NSF grant AST-0955368.

  18. Behavior of titanium dioxide nanoparticles in Lemna minor growth test conditions.

    PubMed

    Li, Ling; Sillanpää, Markus; Tuominen, Meri; Lounatmaa, Kari; Schultz, Eija

    2013-02-01

    Titanium dioxide nanoparticles (TiO(2) NPs) have raised concern of environmental risks due to their widespread applications, but little is known about the potential toxicity of TiO(2) NPs to aquatic plants. The aim of this work was to study the effects of TiO(2) NPs on Lemna minor and to study the behavior of TiO(2) NPs under modified ISO 20079 test conditions. TiO(2) NPs had a tendency to aggregate in ISO (Steinberg) growth medium, but modification of the standard growth medium enabled the exposure of L. minor to TiO(2) NPs. By dilution of the growth medium (1:10), and exposure under semi-static conditions with medium renewal every second or third day, the size of TiO(2) particles remained rather stable throughout the test period. TiO(2) NPs showed no adverse effect on the growth rate or chlorophyll a content of L. minor, even at a high exposure concentration of 5 mg L(-1) and extended exposure time of 14 days. TiO(2) NPs attached onto L. minor cell walls, but no cellular uptake was observed. Although TiO(2) NPs were not toxic to L. minor, the potential transfer of TiO(2) NPs in aquatic food chains, e.g. attached to the plant leaves and other biological surfaces may be of importance, causing exposure of other organisms and contributing to the environmental fate of nanoparticles. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Extreme natural hazards: population growth, globalization and environmental change.

    PubMed

    Huppert, Herbert E; Sparks, R Stephen J

    2006-08-15

    Mankind is becoming ever more susceptible to natural disasters, largely as a consequence of population growth and globalization. It is likely that in the future, we will experience several disasters per year that kill more than 10,000 people. A calamity with a million casualties is just a matter of time. This situation is mainly a consequence of increased vulnerability. Climate change may also be affecting the frequency of extreme weather events as well as the vulnerability of coastal areas due to sea-level rise. Disastrous outcomes can only increase unless better ways are found to mitigate the effects through improved forecasting and warning, together with more community preparedness and resilience. There are particular difficulties with extreme events, which can affect several countries, while the largest events can have global consequences. The hazards of supervolcanic eruptions and asteroid impacts could cause global disaster with threats to civilization and deaths of billions of people. Although these are very rare events, they will happen and require consideration. More frequent and smaller events in the wrong place at the wrong time could have very large human, environmental and economic effects. A sustained effort is needed to identify places at risk and take steps to apply science before the events occur.

  20. 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.

  1. The spatial structure of bacterial communities is influenced by historical environmental conditions.

    PubMed

    Andersson, Martin G I; Berga, Mercè; Lindström, Eva S; Langenheder, Silke

    2014-05-01

    The spatial structure of ecological communities, including that of bacteria, is often influenced by species sorting by contemporary environmental conditions. Moreover, historical processes, i.e., ecological and evolutionary events that have occurred at some point in the past, such as dispersal limitation, drift, priority effects, or selection by past environmental conditions, can be important, but are generally investigated much less. Here, we conducted a field study using 16 rock pools, where we specifically compared the importance of past vs. contemporary environmental conditions for bacterial community structure by correlating present differences in bacterial community composition among pools to environmental conditions measured on the same day, as well as to those measured 2, 4, 6, and 8 d earlier. The results prove that selection by past environmental conditions exists, since we were able to show that bacterial communities are, to a greater extent, an imprint of past compared to contemporary environmental conditions. We suggest that this is the result of a combination of different mechanisms, including priority effects that cause rapid adaptation to new environmental conditions of taxa that have been initially selected by past environmental conditions, and slower rates of turnover in community composition compared to environmental conditions.

  2. Ability of organic and inorganic bedding materials to promote growth of environmental bacteria.

    PubMed

    Godden, S; Bey, R; Lorch, K; Farnsworth, R; Rapnicki, P

    2008-01-01

    The major objective of this study was to contrast the ability of 4 commonly utilized bedding materials to promote growth of environmental bacteria under controlled conditions. A second objective was to describe the relationship between bacterial growth and specific biochemical or nutritional properties of these bedding materials. Unused samples of clean sand (CS; n = 20), recycled sand (RS; n = 21), digested manure solids (DS; n = 15), and shavings (SH; n = 15) were collected from bedding storage areas on 49 commercial Minnesota and Wisconsin dairy farms. Sterilized bedding samples were inoculated with Klebsiella pneumoniae and Enterococcus faecium then incubated, in triplicate, for 72 h at 37 degrees C. Subsamples were collected after 0, 24, 48, and 72 h of incubation for culture and enumeration of bacteria. Subsamples of bedding were also tested for pH, total C content (%), and total N content (%). If bacterial growth occurred, peak levels were typically achieved within 24 h. Digested manure solids promoted the greatest amounts of growth of K. pneumoniae, followed by RS and then SH, whereas CS promoted the least. There would seem to be a tradeoff in selecting SH as a bedding material, because it supported moderate growth of K. pneumoniae but caused a rapid decline in the numbers of E. faecium. However, RS, CS, and DS each only supported relatively small amounts of growth of E. faecium, so the benefit of SH relative to other bedding materials is limited. High bedding pH may partially explain why some bedding materials supported growth of E. faecium (e.g., DS and RS). Both high bedding pH (e.g., as for DS or RS) and high total C (%) content (e.g., as for DS and SH) may partially explain why some bedding materials supported growth of K. pneumoniae.

  3. rRNA regulation during growth and under stringent conditions in Staphylococcus aureus.

    PubMed

    Kästle, Benjamin; Geiger, Tobias; Gratani, Fabio Lino; Reisinger, Rudolf; Goerke, Christiane; Borisova, Marina; Mayer, Christoph; Wolz, Christiane

    2015-11-01

    The control of rRNA synthesis and, thereby, translation is vital for adapting to changing environmental conditions. The decrease of rRNA is a common feature of the stringent response, which is elicited by the rapid synthesis of (p)ppGpp. Here we analysed the properties and regulation of one representative rRNA operon of Staphylococcus aureus under stringent conditions and during growth. The promoters, P1 and P2, are severely downregulated at low intracellular guanosine triphosphate (GTP) concentrations either imposed by stringent conditions or in a guanine auxotroph guaBA mutant. In a (p)ppGpp(0) strain, the GTP level increased under stringent conditions, and rRNA transcription was upregulated. The correlation of the intracellular GTP levels and rRNA promoter activity could be linked to GTP nucleotides in the initiation region of both promoters at positions between +1 and +4. This indicates that not only transcriptional initiation, but also the first steps of elongation, requires high concentrations of free nucleotides. However, the severe downregulation of rRNA in post-exponential growth phase is independent of (p)ppGpp, the composition of the initiation region and the intracellular nucleotide pool. In summary, rRNA transcription in S. aureus is only partially and presumably indirectly controlled by (p)ppGpp. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  4. Shell growth and environmental control of methanophyllic Thyasirid bivalves from Svalbard cold seeps

    NASA Astrophysics Data System (ADS)

    Carroll, Michael; Åström, Emmelie; Ambrose, William; Locke, William; Oliver, Graham; Hong, Wei-Li; Carroll, JoLynn

    2016-04-01

    The analysis of molluscan shell material (sclerochronology) can provide information about an organism's age, growth history, and environmental conditions during its lifetime. Bivalve molluscs are common members of hydrothermal vents and methane cold seeps communities where, supported by chemosynthetic symbionts, they can reach high density and biomass. But little is known about methane-associated bivalve populations inhabiting high-Arctic cold seeps, and sclerochronological analysis of methane-influenced bivalves is rare. We measured growth rates and elemental and isotopic shell signatures in a newly discovered species of bivalve (Thyasiridae) from cold seeps at 350-390m depth southwest of Svalbard. First discovered in 2014, recently described shells of Thyasira capitanea sp.nov. were found at 2 independent seep systems in Storfjordrenna. Mean shell carbon isotopic ratios from inorganic δ13C (mean = -4.8‰) and organic δ13C (mean = -26.9‰) fractions clearly indicate a methane influenced habitat and food source for these organisms. Shell mineral ratios (Li/Ca, Mg/Ca, Mn/Ca, Fe/Ca, Sr/Ca, Ba/Ca, Pb/Ca) sampled along the axis of growth with laser-ablated ICP-MS exhibit variability through time and between sites, suggesting that concentrations of these elements that may be affected by methane emissions. The mineralogical data also elucidates the internal pattern of shell deposition and growth checks, and combined with the isotopic and growth rate data, enables us to interpret the temporal history of methane release from these locations.

  5. IGF-1 release kinetics from chitosan microparticles fabricated using environmentally benign conditions.

    PubMed

    Mantripragada, Venkata P; Jayasuriya, Ambalangodage C

    2014-09-01

    The main objective of this study is to maximize growth factor encapsulation efficiency into microparticles. The novelty of this study is to maximize the encapsulated growth factors into microparticles by minimizing the use of organic solvents and using relatively low temperatures. The microparticles were fabricated using chitosan biopolymer as a base polymer and cross-linked with tripolyphosphate (TPP). Insulin like-growth factor-1 (IGF-1) was encapsulated into microparticles to study release kinetics and bioactivity. In order to authenticate the harms of using organic solvents like hexane and acetone during microparticle preparation, IGF-1 encapsulated microparticles prepared by the emulsification and coacervation methods were compared. The microparticles fabricated by emulsification method have shown a significant decrease (p<0.05) in IGF-1 encapsulation efficiency, and cumulative release during the two-week period. The biocompatibility of chitosan microparticles and the bioactivity of the released IGF-1 were determined in vitro by live/dead viability assay. The mineralization data observed with von Kossa assay, was supported by mRNA expression levels of osterix and runx2, which are transcription factors necessary for osteoblasts differentiation. Real time RT-PCR data showed an increased expression of runx2 and a decreased expression of osterix over time, indicating differentiating osteoblasts. Chitosan microparticles prepared in optimum environmental conditions are a promising controlled delivery system for cells to attach, proliferate, differentiate and mineralize, thereby acting as a suitable bone repairing material. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. IGF-1 Release Kinetics from Chitosan Microparticles Fabricated Using Environmentally Benign Conditions

    PubMed Central

    Mantripragada, Venkata P.; Jayasuriya, Ambalangodage C.

    2014-01-01

    The main objective of this study is to maximize growth factor encapsulation efficiency into microparticles. The novelty of this study is to maximize the encapsulated growth factors into microparticles by minimizing the use of organic solvents and using relatively low temperatures. The microparticles were fabricated using chitosan biopolymer as a base polymer and cross-linked with tripolyphosphate (TPP). Insulin like-growth factor-1 (IGF-1) was encapsulated into microparticles to study release kinetics and bioactivity. In order to authenticate the harms of using organic solvents like hexane and acetone during microparticle preparation, IGF-1 encapsulated microparticles prepared by the emulsification and coacervation methods were compared. The microparticles fabricated by emulsification method have shown a significant decrease (p<0.05) in IGF-1 encapsulation efficiency, and cumulative release during the two-week period. The biocompatibility of chitosan microparticles and the bioactivity of the released IGF-1 were determined in vitro by live/dead viability assay. The mineralization data observed with Von Kossa assay, was supported by mRNA expression levels of osterix and runx2, which are transcription factors necessary for osteoblasts differentiation. Real time RT-PCR data showed an increased expression of runx 2 and a decreased expression of osterix over time, indicating differentiating osteoblasts. Chitosan microparticles prepared in optimum environmental conditions are a promising controlled delivery system for cells to attach, proliferate, differentiate and mineralize, thereby acting as a suitable bone repairing material. PMID:25063148

  7. Perceiving environmental properties from motion information: Minimal conditions

    NASA Technical Reports Server (NTRS)

    Proffitt, Dennis R.; Kaiser, Mary K.

    1989-01-01

    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.

  8. Soil Conditions Affect Growth of Hardwoods in Shelterbelts

    Treesearch

    Willard H. Carmean

    1976-01-01

    Large growth differences were found for hardwoods in shelterbelts on three contrasting soils of western Minnesota. Fiver years after planting, height growth was outstanding for green ash and Russian olive planted on a moderately fine-textured, somewhat poorly drained soil. Growth was much poorer on coarse-textured or shallow soils. Size of planting stock was not...

  9. Nutritional modulation of IGF-1 in relation to growth and body condition in Sceloporus lizards.

    PubMed

    Duncan, Christine A; Jetzt, Amanda E; Cohick, Wendie S; John-Alder, Henry B

    2015-05-15

    Nutrition and energy balance are important regulators of growth and the growth hormone/insulin-like growth factor (GH/IGF) axis. However, our understanding of these functions does not extend uniformly to all classes of vertebrates and is mainly limited to controlled laboratory conditions. Lizards can be useful models to improve our understanding of the nutritional regulation of the GH/IGF-1 axis because many species are relatively easy to observe and manipulate both in the laboratory and in the field. In the present study, the effects of variation in food intake on growth, body condition, and hepatic IGF-1 mRNA levels were measured in (1) juveniles of Sceloporus jarrovii maintained on a full or 1/3 ration and (2) hatchlings of Sceloporus undulatus subjected to full or zero ration with or without re-feeding. These parameters plus plasma IGF-1 were measured in a third experiment using adults of S. undulatus subjected to full or zero ration with or without re-feeding. In all experiments, plasma corticosterone was measured as an anticipated indicator of nutritional stress. In S. jarrovii, growth and body condition were reduced but lizards remained in positive energy balance on 1/3 ration, and hepatic IGF-1 mRNA and plasma corticosterone were not affected in comparison to full ration. In S. undulatus, growth, body condition, hepatic IGF-1 mRNA, and plasma IGF-1 were all reduced by zero ration and restored by refeeding. Plasma corticosterone was increased in response to zero ration and restored by full ration in hatchlings but not adults of S. undulatus. These data indicate that lizards conform to the broader vertebrate model in which severe food deprivation and negative energy balance is required to attenuate systemic IGF-1 expression. However, when animals remain in positive energy balance, reduced food intake does not appear to affect systemic IGF-1. Consistent with other studies on lizards, the corticosterone response to reduced food intake is an unreliable indicator

  10. Stability of antibiotics under growth conditions for thermophilic anaerobes

    SciTech Connect

    Peteranderl, R.; Shotts, E.B. Jr.; Wiegel, J. )

    1990-06-01

    It was shown that the inhibitory effect of kanamycin and streptomycin in a growing culture of Clostridium thermohydrosulfuricum JW 102 is of limited duration. To screen a large number of antibiotics, their stability during incubation under the growth conditions of thermophilic clostridia was determined at 72 and 50C by using a 0.2% yeast extract-amended prereduced mineral medium with a pH of 7.3 or 5.0. Half-lives were determined in a modified MIC test with Escherichia coli, Staphylococcus aureus, and Bacillus megaterium as indicator strains. All compounds tested were similar at the two temperatures or more stable at 50 than at 72C. The half-life (t{sub 1/2}) at pH 7.3 and 72C ranged from 3.3 h (k = 7.26 day{sup {minus}1}, where k (degradation constant) = 1/t{sub 1/2}) for ampicillin to no detectable loss of activity for kanamycin, neomycin, and other antibiotics. Apparently some compounds became more potent during incubation. A change to pH 5.0 caused some compounds to become more labile to become more stable than at pH 7.3.

  11. Dynamics of Deinococcus radiodurans under Controlled Growth Conditions

    PubMed Central

    Jena, Sidhartha S.; Joshi, Hiren M.; Sabareesh, K. P. V.; Tata, B. V. R.; Rao, T. S.

    2006-01-01

    Deinococcus radiodurans is a potent radiation resistant bacterium with immense potential in nuclear waste treatment. In this investigation, the translational and rotational dynamics of dilute suspensions of D. radiodurans cultured under controlled growth conditions was studied by the polarized and depolarized dynamic light-scattering (DLS) techniques. Additionally, confocal laser scanning microscopy was used for characterizing the cultured samples and also for identification of D. radiodurans dimer, tetramer, and multimer morphologies. The data obtained showed translational diffusion coefficients (DT) of 1.2 × 10−9, 1.97 × 10−9, and 2.12 × 10−9 cm2 /s, corresponding to an average size of 3.61, 2.22, and 2.06 μm, respectively, for live multimer, tetramer, and dimer forms of D. radiodurans. Depolarized DLS experiments showed very slow rotational diffusion coefficients (DR) of 0.182/s for dimer and 0.098/s for tetramer morphologies. No measurable rotational diffusion was observed for multimer form. Polarized DLS measurements on live D. radiodurans confirmed that the bacterium is nonmotile in nature. The dynamics of the dead dimer and tetramer D. radiodurans were also studied using polarized and depolarized DLS experiments and compared with the dynamics of live species. The dead cells were slightly smaller in size when compared to the live cells. However, no additional information could be obtained for dead cells from the polarized and depolarized dynamic light-scattering studies. PMID:16829564

  12. Growth condition-dependent Esp expression by Enterococcus faecium affects initial adherence and biofilm formation.

    PubMed

    Van Wamel, Willem J B; Hendrickx, Antoni P A; Bonten, Marc J M; Top, Janetta; Posthuma, George; Willems, Rob J L

    2007-02-01

    A genetic subpopulation of Enterococcus faecium, called clonal complex 17 (CC-17), is strongly associated with hospital outbreaks and invasive infections. Most CC-17 strains contain a putative pathogenicity island encoding the E. faecium variant of enterococcal surface protein (Esp). Western blotting, flow cytometric analyses, and electron microscopy showed that Esp is expressed and exposed on the surface of E. faecium, though Esp expression and surface exposure are highly varied among different strains. Furthermore, Esp expression depends on growth conditions like temperature and anaerobioses. When grown at 37 degrees C, five of six esp-positive E. faecium strains showed significantly increased levels of surface-exposed Esp compared to bacteria grown at 21 degrees C, which was confirmed at the transcriptional level by real-time PCR. In addition, a significant increase in surface-exposed Esp was found in half of these strains when grown at 37 degrees C under anaerobic conditions compared to the level in bacteria grown under aerobic conditions. Finally, amounts of surface-exposed Esp correlated with initial adherence to polystyrene (R(2) = 0.7146) and biofilm formation (R(2) = 0.7535). Polystyrene adherence was competitively inhibited by soluble recombinant N-terminal Esp. This study demonstrates that Esp expression on the surface of E. faecium (i) varies consistently between strains, (ii) is growth condition dependent, and (iii) is quantitatively correlated with initial adherence and biofilm formation. These data indicate that E. faecium senses and responds to changing environmental conditions, which might play a role in the early stages of infection when bacteria transit from oxygen-rich conditions at room temperature to anaerobic conditions at body temperature. In addition, variation of surface exposure may explain the contrasting findings reported on the role of Esp in biofilm formation.

  13. Failure processes in polymers: Environmental stress crack growth and adhesion of elastomeric copolymers to polypropylene

    NASA Astrophysics Data System (ADS)

    Ayyer, Ravishankar

    In CHAPTER 1 slow crack propagation in MDPE pipe was studied in air and Igepals at 50°C to determine the possibility for fatigue to creep correlation in environmental liquids. The stepwise fatigue crack growth in air was preserved in Igepal solutions. Lifetime in Igepal was affected to a much smaller extent as compared to air. The correlation in air was previously established primarily for tests at 21°C. The stepwise mechanism was verified in air at 50°C. The crack growth rate under various loading conditions was related to the maximum stress and R-ratio by a power law relationship. Alternatively a strain rate approach reliably correlated fatigue and creep in air at 50°C except at R=0.1 and frequency less than 1 Hz. In CHAPTER 2 the effect of concentration of Igepal CO 630 on slow crack propagation in MDPE pipe was investigated to determine whether the mechanism was conserved in creep and fatigue as required for the fatigue-to-creep correlation. The mechanism of crack propagation and lifetimes in creep and fatigue at R=0.1 at 50°C were compared to those in air and water. The fatigue and creep behavior followed the same stepwise crack growth mechanism as in air at all the concentrations used. As the concentration increased to 0.01 vol. %, the creep lifetime decreased significantly whereas the lifetime in fatigue gradually increased. At higher concentrations the lifetime was similar in creep and fatigue. In CHAPTER 3 effect of R-ratio on kinetics and mechanism of environmental fatigue and creep crack growth was analyzed in an attempt to predict the environmental stress crack resistance at 50°C. Same methodology was used as previously established for fatigue to creep formulation in air at 50°C. The stepwise mechanism of crack growth in air was conserved in Igepal solutions as R-ratio approached to unity (creep) with few exceptions. At higher R-ratio, the lifetime decreased systematically in Igepal solutions relative to air and was defined as 'Igepal transition

  14. Bathymodiolus growth dynamics in relation to environmental fluctuations in vent habitats

    NASA Astrophysics Data System (ADS)

    Nedoncelle, K.; Lartaud, F.; Contreira Pereira, L.; Yücel, M.; Thurnherr, A. M.; Mullineaux, L.; Le Bris, N.

    2015-12-01

    The deep-sea mussel Bathymodiolus thermophilus is a dominant species in the East Pacific Rise (EPR) hydrothermal vent fields. On the EPR volcanically unstable area, this late colonizer reaches high biomass within 4-5 years on new habitats created by lava flows. The environmental conditions and growth rates characterizing the reestablishment of B. thermophilus populations are however largely unknown, leaving unconstrained the role of this foundation species in the ecosystem dynamics. A typical example from the vent field at 9°50'N that was affected by the last massive eruption was the Bio-9 hydrothermal vent site. Here, six years later, a large mussel population had reestablished. The von Bertalanffy growth model estimates the oldest B. thermophilus specimens to be 1.3 year-old in March 2012, consistent with the observation of scarce juveniles among tubeworms in 2010. Younger cohorts were also observed in 2012 but the low number of individuals, relatively to older cohorts, suggests limited survival or growth of new recruits at this site, that could reflect unsuitable habitat conditions. To further explore this asumption, we investigated the relationships between mussel growth dynamics and habitat properties. The approach combined sclerochronology analyses of daily shell growth with continuous habitat monitoring for two mussel assemblages; one from the Bio-9 new settlement and a second from the V-vent site unreached by the lava flow. At both vent sites, semi-diurnal fluctuations of abiotic conditions were recorded using sensors deployed in the mussel bed over 5 to 10 days. These data depict steep transitions from well oxygenated to oxygen-depleted conditions and from alkaline to acidic pH, combined with intermittent sulfide exposure. These semi-diurnal fluctuations exhibited marked changes in amplitude over time, exposing mussels to distinct regimes of abiotic constraints. The V-vent samples allowed growth patterns to be examined at the scale of individual life and

  15. Overview of environmental and hydrogeologic conditions at Saint Marys, Alaska

    USGS Publications Warehouse

    Nakanishi, Allan S.; Dorava, Joseph M.

    1994-01-01

    The Federal Aviation Administration (FAA) owns or operates airway support facilities near Saint Marys along the Yukon River in west-central Alaska. The FAA is evaluating the severity of environmental contamination and options for remediation of environmental contamination at their facilities. Saint Marys is on a flood plain near the continence of the Yukon and Andreafsky Rivers and has long cold winters and short summers. Residents obtain their drinking water from an infiltration gallery fed by a creek near the village. Surface spills and disposal of hazardous materials combined with potential flooding may affect the quality of the surface and ground water. Alternative drinking-water sources are available, but would likely cost more than existing supplies to develop.

  16. Environmental Conditions in the Norwegian-Iceland Seas, May 1987.

    DTIC Science & Technology

    1987-06-01

    2 I (U) PREJIMflQON. The goal of the prediction element was threefold: (1) using TOPS together with the winds forecasted by the Navy Operational ...predictions by NORDA at the Anti-Submarine Warfare Operations Center (ASWOC), Keflavik, Iceland; (3) near-real-time tactical scale ocean dynamic forcasts...segments by briefly describing the field efforts and the analysis/forecast segment of the operation . Some initial findings concerning the environmental

  17. A Comparison of Three Conditional Growth Percentile Methods: Student Growth Percentiles, Percentile Rank Residuals, and a Matching Method

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Seo, Dong Gi

    2014-01-01

    This article provides a brief overview and comparison of three conditional growth percentile methods; student growth percentiles, percentile rank residuals, and a nonparametric matching method. These approaches seek to describe student growth in terms of the relative percentile ranking of a student in relationship to students that had the same…

  18. A Comparison of Three Conditional Growth Percentile Methods: Student Growth Percentiles, Percentile Rank Residuals, and a Matching Method

    ERIC Educational Resources Information Center

    Wyse, Adam E.; Seo, Dong Gi

    2014-01-01

    This article provides a brief overview and comparison of three conditional growth percentile methods; student growth percentiles, percentile rank residuals, and a nonparametric matching method. These approaches seek to describe student growth in terms of the relative percentile ranking of a student in relationship to students that had the same…

  19. Common lung conditions: environmental pollutants and lung disease.

    PubMed

    Delzell, John E

    2013-06-01

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

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

    PubMed Central

    Fobil, Julius; May, Juergen; Kraemer, Alexander

    2010-01-01

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

  1. Genetic and Environmental Influences on the Growth of Early Reading Skills

    ERIC Educational Resources Information Center

    Petrill, Stephen A.; Hart, Sara A.; Harlaar, Nicole; Logan, Jessica; Justice, Laura M.; Schatschneider, Christopher; Thompson, Lee; DeThorne, Laura S.; Deater-Deckard, Kirby; Cutting, Laurie

    2010-01-01

    Background: Studies have suggested genetic and environmental influences on overall level of early reading whereas the larger reading literature has shown environmental influences on the rate of growth of early reading skills. This study is the first to examine the genetic and environmental influences on both initial level of performance and rate…

  2. Effectiveness of Dry Eye Therapy Under Conditions of Environmental Stress

    PubMed Central

    Madden, Louise C.; Simmons, Peter A.

    2013-01-01

    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 < 0.05). Normal subjects showed some improvements: evaporation with C-L, osmolarity with C and symptoms with C-L and G-L. Change in evaporation was greater for both C-L and G-L versus C (p < 0.05), and there was a trend for C-L to reduce evaporation more than G-L (p < 0.11). There were no significant treatment effects on tear film structure. 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

  3. Sclerochronological records and daily microgrowth of the Peruvian scallop (Argopecten purpuratus, Lamarck, 1819) related to environmental conditions in Paracas Bay, Pisco, Peru

    NASA Astrophysics Data System (ADS)

    Aguirre Velarde, Arturo; Flye-Sainte-Marie, Jonathan; Mendo, Jaime; Jean, Fred

    2015-05-01

    We investigated the rhythm of micro-striae formation in the shell of Argopecten purpuratus and environmental influence on micro-growth increments by monitoring growth over a 98-day period between April and July 2007 under bottom and suspended culture (2 m above the bottom) rearing conditions. The transfer of individuals to the study site induced the formation of a notable growth mark that allowed us to count the number of micro-striae formed between transfer and sampling dates. Micro-striae counts showed a deposition rate of one stria per day independent of rearing condition. This result allowed us to analyse the relationships between growth increments and environmental conditions. We therefore examined the deviations between observed growth rates and growth rates predicted from a Von Bertalanffy growth function. Cross-correlation analysis revealed significant correlations, without time-lag, between these deviations and both particulate organic carbon and nitrogen concentrations in the bottom treatment. Additionally, we observed negative correlations with temperature and current speed at this depth with time-lags of 1 and 10 days respectively. In the suspended treatment, we observed a significant negative correlation with temperature, only with a 12-day lag-time. Our results show that growth response to environmental variability is not always instantaneous. This delay can be explained by the time delay over which metabolic processes need to be performed (e.g. digestion, use/movements of reserves, growth, reproduction). Further modeling studies could help to better understand these processes.

  4. Environmental- and growth stage-related differences in the susceptibility of terrestrial isopods to UV radiation.

    PubMed

    Morgado, Rui; Ferreira, Nuno G C; Tourinho, Paula; Ribeiro, Fabianne; Soares, Amadeu M V M; Loureiro, Susana

    2013-09-05

    Global environmental changes are nowadays one of the most important issues affecting terrestrial ecosystems. One of its most significant expressions is the increasing ultraviolet radiation (UVR) arising from the human-induced depletion in ozone layer. Therefore, to investigate the effects of UVR on the terrestrial isopod Porcellionides pruinosus a multiple biomarker approach was carried out. Two experiments were performed in order to analyze the importance of the exposure environment and the growth stage on the UV-induced damages. First, adult individuals were exposed to UVR in three exposure environments (soil, soil with leaves, and plaster). Thereafter, three growth stages using soil as the exposure condition were tested. Integrated biomarker responses (IBR) suggested that UV effects were higher in plaster, and mostly identified by changes in acetylcholinesterase and glutathione-S-transferases activities, lipid peroxidation rates, and total energy available. The effects in soil and soil with leaves were not so clear. In the growth stages' experiment, juveniles and pre-adults were found to be more affected than adults, with the greatest differences between irradiated and non-irradiated isopods occurring in energy-related parameters. Our findings suggest that soil surface-living macrofauna may be prone to deleterious effects caused by UVR, highlighting the importance of taking the media of exposure and growth stage in account. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Predicting Plant Performance Under Simultaneously Changing Environmental Conditions—The Interplay Between Temperature, Light, and Internode Growth

    PubMed Central

    Kahlen, Katrin; Chen, Tsu-Wei

    2015-01-01

    Plant performance is significantly influenced by prevailing light and temperature conditions during plant growth and development. For plants exposed to natural fluctuations in abiotic environmental conditions it is however laborious and cumbersome to experimentally assign any contribution of individual environmental factors to plant responses. This study aimed at analyzing the interplay between light, temperature and internode growth based on model approaches. We extended the light-sensitive virtual plant model L-Cucumber by implementing a common Arrhenius function for appearance rates, growth rates, and growth durations. For two greenhouse experiments, the temperature-sensitive model approach resulted in a precise prediction of cucumber mean internode lengths and number of internodes, as well as in accurately predicted patterns of individual internode lengths along the main stem. In addition, a system's analysis revealed that environmental data averaged over the experimental period were not necessarily related to internode performance. Finally, the need for a species-specific parameterization of the temperature response function and related aspects in modeling temperature effects on plant development and growth is discussed. PMID:26734036

  6. Impact of different environmental conditions on the aggregation of biogenic U(IV) nanoparticles synthesized by Desulfovibrio alaskensis G20.

    PubMed

    Şengör, S Sevinç; Singh, Gursharan; Dohnalkova, Alice; Spycher, Nicolas; Ginn, Timothy R; Peyton, Brent M; Sani, Rajesh K

    2016-12-01

    This study investigates the impact of specific environmental conditions on the formation of colloidal U(IV) nanoparticles by the sulfate reducing bacteria (SRB, Desulfovibrio alaskensis G20). The reduction of soluble U(VI) to less soluble U(IV) was quantitatively investigated under growth and non-growth conditions in bicarbonate or 1,4-piperazinediethanesulfonic acid (PIPES) buffered environments. The results showed that under non-growth conditions, the majority of the reduced U nanoparticles aggregated and precipitated out of solution. High resolution transmission electron microscopy revealed that only a very small fraction of cells had reduced U precipitates in the periplasmic spaces in the presence of PIPES buffer, whereas in the presence of bicarbonate buffer, reduced U was also observed in the cytoplasm with greater aggregation of biogenic U(IV) particles at higher initial U(VI) concentrations. The same experiments were repeated under growth conditions using two different electron donors (lactate and pyruvate) and three electron acceptors (sulfate, fumarate, and thiosulfate). In contrast to the results of the non-growth experiments, even after 0.2 μm filtration, the majority of biogenic U(IV) remained in the aqueous phase resulting in potentially mobile biogenic U(IV) nanoparticles. Size fractionation results showed that U(IV) aggregates were between 18 and 200 nm in diameter, and thus could be very mobile. The findings of this study are helpful to assess the size and potential mobility of reduced U nanoparticles under different environmental conditions, and would provide insights on their potential impact affecting U(VI) bioremediation efforts at subsurface contaminated sites.

  7. Impact of different environmental conditions on the aggregation of biogenic U(IV) nanoparticles synthesized by Desulfovibrio alaskensis G20

    SciTech Connect

    Şengör, S. Sevinç; Singh, Gursharan; Dohnalkova, Alice; Spycher, Nicolas; Ginn, Timothy R.; Peyton, Brent M.; Sani, Rajesh K.

    2016-09-13

    This study investigates the impact of specific environmental conditions on the formation of colloidal U(IV) nanoparticles by the sulfate reducing bacteria (SRB, Desulfovibrio alaskensis G20). The reduction of soluble U(VI) to less soluble U(IV) was quantitatively investigated under growth and non-growth conditions in bicarbonate or 1,4-piperazinediethanesulfonic acid (PIPES) buffered environments. The results showed that under non-growth conditions, the majority of the reduced U nanoparticles aggregated and precipitated out of solution. High resolution transmission electron microscopy revealed that only a very small fraction of cells had reduced U precipitates in the periplasmic spaces in the presence of PIPES buffer, whereas in the presence of bicarbonate buffer, reduced U was also observed in the cytoplasm with greater aggregation of biogenic U(IV) particles at higher initial U(VI) concentrations. The same experiments were repeated under growth conditions using two different electron donors (lactate and pyruvate) and three electron acceptors (sulfate, fumarate, and thiosulfate). In contrast to the results of the non-growth experiments, even after 0.2 m filtration, the majority of biogenic U(IV) remained in the aqueous phase resulting in potentially mobile biogenic U(IV) nanoparticles. Size fractionation results showed that U(IV) aggregates were between 18 and 200 nm in diameter, and thus could be very mobile. The findings of this study are helpful to assess the size and potential mobility of reduced U nanoparticles under different environmental conditions, and would provide insights on their potential impact affecting U(VI) bioremediation efforts at subsurface contaminated sites.

  8. Impact of environmental noise on growth and neuropsychological development of newborn rats.

    PubMed

    Zheng, Yanyan; Meng, Meng; Zhao, Congmin; Liao, Wei; Zhang, Yuping; Wang, Liyan; Wen, Enyi

    2014-05-01

    We aimed to investigate the effects of environmental noise exposure on the growth and neuropsychological development in neonatal rats. Twenty-four postnatal 7-day-old Sprague-Dawley rats were randomly assigned into control, high-noise and reduced noise groups. The rats in the high-noise group were exposed to 90 dB white noise, and those in the control group were grown under standard condition, while those in the reduced noise group were exposed to standard condition with sound-absorbing cotton. Ten, 15, and 20 days post noise exposure, both the body weight and length of the rats in high-noise group were lower than those in the control and reduced noise groups, respectively. The secretion of growth hormone was significantly decreased in the rats exposed to high noise environment, compared to those exposed to standard condition and reduced noise. More interestingly, the swimming distance was apparently increased and the swimming speed was significantly decreased in high-noise group compared with those in control and reduced noise groups. Importantly, the mRNA and protein levels of SYP in the rats hippocampus were significantly decreased in high-noise group compare with those in control and reduced noise groups. Similarly, the positive expression of SYP in the CA1 region of hippocampus was also significantly decreased in the high noise group rats. In conclusion, our results demonstrated that high noise exposure could decrease the production of growth hormone and SYP in neonatal rats, which may retard the growth of weight and length and the capability of learning and memory.

  9. Can environmental conditions trigger cyanobacterial surfaces and following carbonate formation: implication for biomineralization and biotechnology

    NASA Astrophysics Data System (ADS)

    Paulo, C.; Dittrich, M.; Zhu, T.

    2015-12-01

    In this presentation we will give an overview what kind of the factors may trigger carbonate formations at the cell surfaces under a variety of environmental conditions. As examples, we will present the results from our recent studies on formation of calcium carbonates, dolomites and bio-cements. The extracellular polymeric substances (EPS) in the Synechococcuscell envelope are recognized key players in the nucleation of carbonates in marine and freshwater environments. Yet, little is known about a nutrient contents control over the molecular composition of Synechococcus cell envelope, and consequently, biomineralization. In the first study, we investigated how a variation of the phosphorus (P) in the growth media can lead to changes in the surface reactivity of the cells and impact their ability to form carbonates. The objective of the second study is to gain insights into the spatial distribution of cyanobacterial EPS and dolomite from different sediment layers of Khor Al-Adaid sabkha (Qatar). Here, we characterized microbial mats on molecular level in respect of organic and inorganic components using in-situ 2D Raman spectroscopy and Atomic Force Microscopy (AFM) were used. Additionally, 2D chemical maps of sediment layers documented spectral characterizations of minerals and organic matter of microbial origins at high spatial resolution. Finally, we will show the results from the experiments with auto-phototrophic cyanobacteria Gloeocapsa PCC73106, which habitat on the monument surfaces, towards its application for bio-concrete, a product of microbial carbonate precipitation. We studied the biomineralization in biofilm forming Gloeocapsa PCC73106 on the concrete surface as a pre-requirement for microbial carbonate precipitation. Biomineralization on the concrete surface by live cells and killed cells were compared with that under the abiotic condition. Our experiments allow us to conclude that environmental conditions play a significant role in the control of

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

    NASA Astrophysics Data System (ADS)

    Ruprecht, Eszter; Fenesi, Annamária; Nijs, Ivan

    2013-02-01

    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.

  11. [Patterns in the growth and functioning of single-cell organisms under conditions of altered gravitational force].

    PubMed

    Tairbekov, M G; Gabova, A V; Gavrilova, O N

    1997-01-01

    The results of studies over many years on various types of unicellular free-swimming organisms in conditions of altered gravity (hyper-, hypo-, and microgravity ranging from 10(-5) to 5 g) were reviewed. Laws governing their growth and functioning under these conditions were established. In general, gravisensing of unicellular free-swimming organisms depends on their metabolic activity and mobility, on the one hand, and on the environmental conditions of the population, on the other. A working hypothesis on the priority of ecophysiological properties (environment, metabolic activity, and mobility) over morphological properties (mass, dimensions, and shape) in receiving and processing of gravity stimuli at the cellular level has been formulated.

  12. Effects of nutritional and environmental conditions on Salmonella sp. biofilm formation.

    PubMed

    Speranza, Barbara; Corbo, Maria Rosaria; Sinigaglia, Milena

    2011-01-01

    Biofilm formation on food industry surfaces has important health and economic consequences, since they can serve as a potential source of contamination for food products, which may lead to food spoilage or transmission of diseases. Salmonella sp. is one of the most important foodborne pathogens and several studies have led to the discovery that these bacteria are capable of adhering and forming biofilms on different surfaces. The attachment of bacterial cells is affected by several factors, including the medium in which they are grown, motility, growth phase of the cells, type and properties of the inert material, presence of organic material, temperature, pH, contact time, and so on. This investigation focused on the study and quantification of the effects of temperature (20 to 40 °C), pH (4.5 to 7.5), and medium composition (0.5 to 2.5 g/L of peptone) on biofilm formation by Salmonella sp. on stainless steel through surface response modeling. Results highlighted that the target strain was able to adhere on stainless steel, under all the conditions tested. To assess potential differences, the aptitude to biofilm formation (ABF), defined as the time necessary to start adhesion on the surface, was calculated by using the Gompertz equation. This parameter was modeled through a stepwise regression procedure and experimental conditions resulting in the greater ABF were growth in poor media (1.0 to 1.5 g/L of peptone), incubation temperature of about 30 °C, pH close to 6.0. Practical Application: The importance of this work lies in its extension of our knowledge about the effect of different environmental conditions on Salmonella adherence to stainless steel food-processing equipment, as a better understanding of biofilms may provide valuable pathways for the prevention of biofilm formation.

  13. The influence of different environmental and climatic conditions on vegetated aeolian dune landscape development and response

    NASA Astrophysics Data System (ADS)

    Nield, Joanna M.; Baas, Andreas C. W.

    2008-11-01

    Aeolian dune field development in coastal and semi-arid environments is a function of complex ecogeomorphic interactions which are sensitive to fluctuations in climatic and environmental conditions. We explore the relationships between ecological and geomorphic processes in the development of these landscape patterns and speculate on their response to variations in vegetation vitality and sediment transport capacity, indicating possible consequences of climate and land use change, using the Discrete ECogeomorphic Aeolian Landscape (DECAL) cellular automaton algorithm. This algorithm models dune field behaviour that reflects long-term trends prevalent in palaeo-records, but also elucidates possible evolutionary progressions, relaxation period sequences and threshold sensitivities. The landscape response is sensitive both to the perturbation itself and the state of the system when the disturbance occurs. Response amplitude decreases in simulated systems with reduced mobility unless an external disturbance mimicking fire or land clearance is applied concurrently with a reduction in growth vigour triggering a threshold type response when sufficient vegetation is removed. The model demonstrates that the relative response characteristics of the multiple vegetation types and their mutual feedback with geomorphic processes impart a significant influence on landscape equilibrium or attractor states. Fast growing vegetation enables the formation of hairpin (long-walled) parabolic dune systems, which eventually become sediment starved and stabilise, whereas inhospitable conditions inhibiting vegetation growth contribute to the development of active transgressive transverse dune fields. This simple vegetated dune model illustrates the power and versatility of a cellular automaton approach for exploring thresholds, sensitivities and possible evolutionary trajectories associated with the interactions between ecology, geomorphology and climatic conditions in complex earth surface

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

    PubMed Central

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

    2002-01-01

    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

  15. Bacterial assisted degradation of chlorpyrifos: The key role of environmental conditions, trace metals and organic solvents.

    PubMed

    Khalid, Saira; Hashmi, Imran; Khan, Sher Jamal

    2016-03-01

    Wastewater from pesticide industries, agricultural or surface runoff containing pesticides and their residues has adverse environmental impacts. Present study demonstrates effect of petrochemicals and trace metals on chlorpyrifos (CP) biotransformation often released in wastewater of agrochemical industry. Biodegradation was investigated using bacterial strain Pseudomonas kilonensis SRK1 isolated from wastewater spiked with CP. Optimal environmental conditions for CP removal were CFU (306 × 10(6)), pH (8); initial CP concentration (150 mg/L) and glucose as additional carbon source. Among various organic solvents (petrochemicals) used in this study toluene has stimulatory effect on CP degradation process using SRK1, contrary to this benzene and phenol negatively inhibited degradation process. Application of metal ions (Cu (II), Fe (II) Zn (II) at low concentration (1 mg/L) took part in biochemical reaction and positively stimulated CP degradation process. Metal ions at high concentrations have inhibitory effect on degradation process. A first order growth model was shown to fit the data. It could be concluded that both type and concentration of metal ions and petrochemicals can affect CP degradation process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Overview of environmental and hydrogeologic conditions at Tanana, Alaska

    USGS Publications Warehouse

    Nakanishi, Allan S.; Dorava, Joseph M.

    1994-01-01

    The remote Native village of Tanana along the Yukon River in west-central Alaska has long cold winters and short summers. The Federal Aviation Administration owns or operates airway support facilities near Tanana and wishes to consider the subsistence lifestyle of the residents and the quality of the current environment when evaluating the severity of environmental contamination at these facilities. Tanana is located on the flood plain of the Yukon River and obtains its drinking water from a shallow aquifer located in thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Yukon River may affect the quality of the ground water. Alternative drinking-water sources are available, but may cost more than existing supplies.

  17. Overview of environmental and hydrogeologic conditions at Moses Point, Alaska

    USGS Publications Warehouse

    Dorava, J.M.; Ayres, R.P.; Sisco, W.C.

    1994-01-01

    The Federal Aviation Administration facility at Moses Point is located at the mouth of the Kwiniuk River on the Seward Peninsula in northwestern Alaska. This area has long cold winters and short summers which affect the hydrology of the area. The Federal Aviation Administration owns or operates airport support facilities at the Moses Point site and wishes to consider the subsistence lifestyles of area residents and the quality of the current environment when evaluating options for remediation of environmental contamination at their facilities. Currently no operating wells are in the area, but the vulnerability of the aquifer and other alternative water supplies are being evaluated because the Federal Aviation Administration has a potential liability for the storage and use of hazardous materials in the area.

  18. Environmental overview and hydrogeologic conditions at Aniak, Alaska

    USGS Publications Warehouse

    Dorava, J.M.

    1994-01-01

    The remote Native village of Aniak, on the flood plain of the Kuskokwim River in southwestern Alaska, has long cold winters and short summers that affect both the hydrology of the area and the lifestyle of the residents. Aniak obtains its drinking water from a shallow aquifer in the thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Kuskokwim River may affect the quality of the ground water. Alternative drinking water sources are available but at significantly greater cost than existing supplies. The Federal Aviation Administration (FAA) owns or operates airport support facilities in Aniak. The subsistence lifestyle of the villagers and the quality of the current environment must be taken into consideration when the FAA evaluates options for remediation of environmental contamination at these facilities. This report describes the ground- and surface-water hydrology, geology, climate, vegetation, soils, and flood potential of the areas surrounding the FAA sites.

  19. Overview of environmental and hydrogeologic conditions at Fort Yukon, Alaska

    USGS Publications Warehouse

    Nakanishi, Allan S.; Dorava, Joseph M.

    1994-01-01

    The village of Fort Yukon along the Yukon River in east-central Alaska has long cold winters and short summers. The Federal Aviation Administration operates and supports some airport facilities in Fort Yukon and is evaluating the severity of environmental contamination and options for remediation of such contamination at their facilites. Fort Yukon is located on the flood plain of the Yukon River and obtains its drinking water from a shallow aquifer located in the thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Yukon River may affect the quality of the ground water. Alternative drinking-water sources are available from local surface-water bodies or from presently unidentified confined aquifers.

  20. Overview of environmental and hydrogeologic conditions at Galena, Alaska

    USGS Publications Warehouse

    Nakanishi, Allan S.; Dorava, Joseph M.

    1994-01-01

    The remote Native village of Galena along the Yukon River in west-central Alaska has long cold winters and short summers that affects the hydrology of the area. The Federal Aviation Administration owns or operates airport support facilities in Galena and wishes to consider the subsistence lifestyle of the residents and the quality of the current environment when evaluating options for remediation of environmental contamination at these facilities. Galena is located on the flood plain of the Yukon River and obtains its drinking water from a shallow aquifer located in the thick alluvium underlying the village. Surface spills and disposal of hazardous materials combined with annual flooding of the Yukon River may affect the quality of the ground water. Alternative drinking-water sources are available but at significantly greater cost than existing supplies.

  1. Environmental conditions regulate the impact of plants on cloud formation

    PubMed Central

    Zhao, D. F.; Buchholz, A.; Tillmann, R.; Kleist, E.; Wu, C.; Rubach, F.; Kiendler-Scharr, A.; Rudich, Y.; Wildt, J.; Mentel, Th. F.

    2017-01-01

    The terrestrial vegetation emits large amounts of volatile organic compounds (VOC) into the atmosphere, which on oxidation produce secondary organic aerosol (SOA). By acting as cloud condensation nuclei (CCN), SOA influences cloud formation and climate. In a warming climate, changes in environmental factors can cause stresses to plants, inducing changes of the emitted VOC. These can modify particle size and composition. Here we report how induced emissions eventually affect CCN activity of SOA, a key parameter in cloud formation. For boreal forest tree species, insect infestation by aphids causes additional VOC emissions which modifies SOA composition thus hygroscopicity and CCN activity. Moderate heat increases the total amount of constitutive VOC, which has a minor effect on hygroscopicity, but affects CCN activity by increasing the particles' size. The coupling of plant stresses, VOC composition and CCN activity points to an important impact of induced plant emissions on cloud formation and climate. PMID:28218253

  2. Environmental conditions regulate the impact of plants on cloud formation

    NASA Astrophysics Data System (ADS)

    Zhao, D. F.; Buchholz, A.; Tillmann, R.; Kleist, E.; Wu, C.; Rubach, F.; Kiendler-Scharr, A.; Rudich, Y.; Wildt, J.; Mentel, Th. F.

    2017-02-01

    The terrestrial vegetation emits large amounts of volatile organic compounds (VOC) into the atmosphere, which on oxidation produce secondary organic aerosol (SOA). By acting as cloud condensation nuclei (CCN), SOA influences cloud formation and climate. In a warming climate, changes in environmental factors can cause stresses to plants, inducing changes of the emitted VOC. These can modify particle size and composition. Here we report how induced emissions eventually affect CCN activity of SOA, a key parameter in cloud formation. For boreal forest tree species, insect infestation by aphids causes additional VOC emissions which modifies SOA composition thus hygroscopicity and CCN activity. Moderate heat increases the total amount of constitutive VOC, which has a minor effect on hygroscopicity, but affects CCN activity by increasing the particles' size. The coupling of plant stresses, VOC composition and CCN activity points to an important impact of induced plant emissions on cloud formation and climate.

  3. Environmental conditions regulate the impact of plants on cloud formation.

    PubMed

    Zhao, D F; Buchholz, A; Tillmann, R; Kleist, E; Wu, C; Rubach, F; Kiendler-Scharr, A; Rudich, Y; Wildt, J; Mentel, Th F

    2017-02-20

    The terrestrial vegetation emits large amounts of volatile organic compounds (VOC) into the atmosphere, which on oxidation produce secondary organic aerosol (SOA). By acting as cloud condensation nuclei (CCN), SOA influences cloud formation and climate. In a warming climate, changes in environmental factors can cause stresses to plants, inducing changes of the emitted VOC. These can modify particle size and composition. Here we report how induced emissions eventually affect CCN activity of SOA, a key parameter in cloud formation. For boreal forest tree species, insect infestation by aphids causes additional VOC emissions which modifies SOA composition thus hygroscopicity and CCN activity. Moderate heat increases the total amount of constitutive VOC, which has a minor effect on hygroscopicity, but affects CCN activity by increasing the particles' size. The coupling of plant stresses, VOC composition and CCN activity points to an important impact of induced plant emissions on cloud formation and climate.

  4. Environmental controls on growth of the massive coral Porites.

    PubMed

    Lough; Barnes

    2000-03-15

    Annual density banding provided growth characteristics for 245 similar-sized, massive colonies of Porites from similar locations on 29 reefs from across the length and breadth of the Great Barrier Reef (GBR), Australia. Values obtained were density, extension rate, and calcification rate. Tissue thickness, the depth to which skeletons were occupied by tissue at the time of collection, was also measured. Extension rate, calcification rate, and tissue thickness were significantly greater at the top of colonies than at the sides. Extension rate and calcification rate decreased from north to south along the GBR (latitudinal range of approximately 9 degrees ) and were significantly and directly related to annual average sea surface temperature (SST; range approximately 25-27 degrees C). For each 1 degrees C rise in SST, average annual calcification increased by 0.39 g cm(-2) year(-1) and average annual extension increased by 3.1 mm year(-1) (c.f. average values of 1.63 g cm(-2) year(-1) and 12.9 mm year(-1), respectively). Density was inversely correlated with extension rate and increased with distance offshore. Data for massive Porites colonies from the GBR were extended though 20 degrees of latitude and an average annual SST range of 23-29 degrees C using published data for the Hawaiian Archipelago (Grigg, R.W., 1981. Coral reef development at high latitudes in Hawaii. Proc. 4th Int. Coral Reef Symp., Manila, Vol. 1, pp. 687-693; Grigg, R.W., 1997. Paleoceanography of coral reefs in the Hawaiian-Emperor Chain - revisited. Coral Reefs 16, S33-S38) and Phuket, Thailand (Scoffin. T.P., Tudhope. A.W., Brown. B.E., Chansang. H., Cheeney. R.F., 1992. Patterns and possible environmental controls of skeletogenesis of Porites lutea, South Thailand. Coral Reefs 11, 1-11). The response of calcification rate to temperature remained linear. Variation in annual average SST accounted for 84% of the variance. For each 1 degrees C rise in SST, average annual calcification increased by

  5. Analysis of uropathogenic Escherichia coli biofilm formation under different growth conditions.

    PubMed

    Adamus-Białek, Wioletta; Kubiak, Anna; Czerwonka, Grzegorz

    2015-01-01

    The ability to form different types of biofilm enables bacteria to survive in a harsh or toxic environment. Different structures of biofilms are related to different surfaces and environment of bacterial growth. The aim of this study was analysis of the biofilm formation of 115 clinical uropathogenic Escherichia coli strains under different growth conditions: surface for biofilm formation, medium composition and time of incubation. The biofilm formation after 24 h, 48 h, 72 h and 96 h was determined spectrophotometrically (A531) after crystal violet staining and it was correlated with bacterial growth (A600). The live and dead cells in biofilm structures was also observed on the glass surface by an epi-fluorescence microscope. Additionally, the presence of rpoS, sdiA and rscA genes was analyzed. The statistical significance was estimated by paired T-test. The observed biofilms were different for each particular strain. The biofilm formation was the highest in the rich medium (LB) after 24 h and its level hasn't changed in time. When biofilm level was compared to bacterial growth (relative biofilm) - it was higher in a minimal medium in comparison to enriched medium. These results suggest that most of the bacterial cells prefer to live in a biofilm community under the difficult environmental conditions. Moreover, biofilm formation on polyurethane surface did not correlate with biofilm formation on glass. It suggests that mechanisms of biofilm formation can be correlated with other bacterial properties. This phenomenon may explain different types of biofilm formation among one species and even one pathotype - uropathogenic Escherichia coli.

  6. Optimal Conditions for the Mycelial Growth of Coprinus comatus Strains

    PubMed Central

    Lee, Yun-Hae; Liu, Jun-Jie; Ju, Young-Cheol

    2009-01-01

    The principal objective of this study was to acquire basic data regarding the mycelial growth characteristics for the artificial cultivation of Coprinus comatus. 12 URP primers were employed to evaluate the genetic relationships of C. comatus, and the results were divided into three groups. Among six kinds of mushroom media, MYP medium was selected as the most favorable culture medium for C. comatus. The optimal temperature and pH ranges for the mycelial growth of C. comatus were 23~26℃ and pH 6~8, respectively. The carbon and nitrogen sources for optimal mycelial growth were sucrose and tryptone, respectively. PMID:23983517

  7. Elemental markers in elasmobranchs: effects of environmental history and growth on vertebral chemistry.

    PubMed

    Smith, Wade D; Miller, Jessica A; Heppell, Selina S

    2013-01-01

    Differences in the chemical composition of calcified skeletal structures (e.g. shells, otoliths) have proven useful for reconstructing the environmental history of many marine species. However, the extent to which ambient environmental conditions can be inferred from the elemental signatures within the vertebrae of elasmobranchs (sharks, skates, rays) has not been evaluated. To assess the relationship between water and vertebral elemental composition, we conducted two laboratory studies using round stingrays, Urobatis halleri, as a model species. First, we examined the effects of temperature (16°, 18°, 24°C) on vertebral elemental incorporation (Li/Ca, Mg/Ca, Mn/Ca, Zn/Ca, Sr/Ca, Ba/Ca). Second, we tested the relationship between water and subsequent vertebral elemental composition by manipulating dissolved barium concentrations (1x, 3x, 6x). We also evaluated the influence of natural variation in growth rate on elemental incorporation for both experiments. Finally, we examined the accuracy of classifying individuals to known environmental histories (temperature and barium treatments) using vertebral elemental composition. Temperature had strong, negative effects on the uptake of magnesium (DMg) and barium (DBa) and positively influenced manganese (DMn) incorporation. Temperature-dependent responses were not observed for lithium and strontium. Vertebral Ba/Ca was positively correlated with ambient Ba/Ca. Partition coefficients (DBa) revealed increased discrimination of barium in response to increased dissolved barium concentrations. There were no significant relationships between elemental incorporation and somatic growth or vertebral precipitation rates for any elements except Zn. Relationships between somatic growth rate and DZn were, however, inconsistent and inconclusive. Variation in the vertebral elemental signatures of U. halleri reliably distinguished individual rays from each treatment based on temperature (85%) and Ba exposure (96%) history. These

  8. Elemental Markers in Elasmobranchs: Effects of Environmental History and Growth on Vertebral Chemistry

    PubMed Central

    Smith, Wade D.; Miller, Jessica A.; Heppell, Selina S.

    2013-01-01

    Differences in the chemical composition of calcified skeletal structures (e.g. shells, otoliths) have proven useful for reconstructing the environmental history of many marine species. However, the extent to which ambient environmental conditions can be inferred from the elemental signatures within the vertebrae of elasmobranchs (sharks, skates, rays) has not been evaluated. To assess the relationship between water and vertebral elemental composition, we conducted two laboratory studies using round stingrays, Urobatis halleri, as a model species. First, we examined the effects of temperature (16°, 18°, 24°C) on vertebral elemental incorporation (Li/Ca, Mg/Ca, Mn/Ca, Zn/Ca, Sr/Ca, Ba/Ca). Second, we tested the relationship between water and subsequent vertebral elemental composition by manipulating dissolved barium concentrations (1x, 3x, 6x). We also evaluated the influence of natural variation in growth rate on elemental incorporation for both experiments. Finally, we examined the accuracy of classifying individuals to known environmental histories (temperature and barium treatments) using vertebral elemental composition. Temperature had strong, negative effects on the uptake of magnesium (DMg) and barium (DBa) and positively influenced manganese (DMn) incorporation. Temperature-dependent responses were not observed for lithium and strontium. Vertebral Ba/Ca was positively correlated with ambient Ba/Ca. Partition coefficients (DBa) revealed increased discrimination of barium in response to increased dissolved barium concentrations. There were no significant relationships between elemental incorporation and somatic growth or vertebral precipitation rates for any elements except Zn. Relationships between somatic growth rate and DZn were, however, inconsistent and inconclusive. Variation in the vertebral elemental signatures of U. halleri reliably distinguished individual rays from each treatment based on temperature (85%) and Ba exposure (96%) history. These

  9. Prebiotic cell membranes that survive extreme environmental pressure conditions.

    PubMed

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

    2014-08-04

    Attractive candidates for compartmentalizing prebiotic cells are membranes comprised of single-chain fatty acids. It is generally believed that life may have originated in the depth of the protoocean, that is, under high hydrostatic pressure conditions, but the structure and physical-chemical properties of prebiotic membranes under such conditions have not yet been explored. We report the temperature- and pressure-dependent properties of membranes composed of prebiotically highly-plausible lipids and demonstrate that prebiotic membranes could not only withstand extreme temperatures, but also serve as robust models of protocells operating in extreme pressure environments. We show that pressure not only increases the stability of vesicular systems but also limits their flexibility and permeability to solutes, while still keeping the membrane in an overall fluid-like and thus functional state. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Enabling hygienic behavior among preschoolers: improving environmental conditions through a multifaceted intervention.

    PubMed

    Rosen, Laura; Zucker, David; Brody, David; Engelhard, Dan; Meir, Marina; Manor, Orly

    2011-01-01

    Environmental conditions often serve as critical enabling factors for health promotion. This article describes the effect of a preschool hygiene intervention program on classroom environmental conditions. Cluster randomized trial, with randomization at the level of the preschool. State-run preschools in Jerusalem. Forty secular and religious Jerusalem preschools (including 1029 children). A multidisciplinary hygiene intervention that included changes to the preschool environment. Presence of soap, soap dispenser, paper towel, paper towel dispenser, cloth towels, communal cup, or personal cups. Generalized estimating equations and Fisher's exact test were used to estimate the effect of the intervention program on environmental conditions. Information was obtained from most (97.9%) visits. Baseline environmental hygienic conditions were poor. Relative to the control group, the following environmental conditions were better in the intervention group after program implementation: soap (odds ratio [OR] = 14.7; p < .01), paper towels (OR = 13.5; p < .01), communal cups (OR = .05; p < .01), soap dispensers (secular preschools only, p < .01), individual cups (secular, p < .01; religious, OR = 18.7; p < .02). Environmental hygiene in the Israeli preschools studied was deficient at baseline but amenable to change. Improvement in environmental conditions was a necessary enabling factor for the changes in hand-washing behavior that were observed among the children. Sustained environmental change is possible in the preschool environment.

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

    PubMed

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

    2015-04-01

    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. © 2015 John Wiley & Sons Ltd/CNRS.

  12. Combined effects of working environmental conditions in VDT work.

    PubMed

    Takahashi, K; Sasaki, H; Saito, T; Hosokawa, T; Kurasaki, M; Saito, K

    2001-04-15

    The combined effects of city noise and luminance of the computer display were evaluated from the changes in lymphocytes and mental activities of participants. Healthy male students were tested under the following four experimental conditions: (1) a calculating task on a video display terminal (VDT) with luminance of 90 cd m(-2) without city noise; (2) a calculating task on a VDT with luminance of 20 cd m(-2) without city noise; (3) a calculating task on a VDT with luminance of 90 cd m(-2) with city noise of 70 dB(A); and (4) a calculating task on a VDT with luminance of 20 cd m(-2) with city noise of 70 dB(A). A visual reaction test (VRT) was performed, and critical flicker fusion frequency (CFF), heart rate (HR), numbers of circulating white blood cells (WBCs), lymphocyte subsets and subjective symptoms of fatigue were measured (1) before; (2) just after; and (3) 30 min after each 60 min test. Subjective symptoms of fatigue significantly increased just after experiments conducted under the two noisy conditions. VRT and CFF showed significant changes in the case of the high-luminance display with noise. WBCs and neutrophils showed significant increases in the two quiet conditions. These results suggested that high luminance with noise had the most effect on subjective fatigue and mental activities.

  13. Impact of environmental conditions on bacterial photoreactivation in wastewater effluents.

    PubMed

    Shafaei, Shirin; Klamerth, Nikolaus; Zhang, Yanyan; McPhedran, Kerry; Bolton, James R; Gamal El-Din, Mohamed

    2017-01-25

    Photoreactivation is a process where ultraviolet (UV)-induced damage to the DNA of microorganisms can be reversed by exposure to near UV and visible light. To date, most photoreactivation experiments have been carried out under laboratory conditions using standard microorganisms that do not reflect the natural conditions of municipal wastewater effluents. Photoreactivation could increase the concentration of pathogens released into natural systems, leading to negative impacts on fish, shellfish, and clams. In addition, pathogen release can increase health risks of downstream activities, such as swimming. This study focused on the photoreactivation of total coliforms in municipal wastewater effluents under natural sunlight conditions. The concept of 'effective reactivation fluence' (ERF) is used to evaluate and normalize the results from various light sources for a direct comparison. ERF values higher than 30 J cm(-2), in conjunction with lowered nutrient concentrations (dilution of effluents with river water), decreased the photoreactivation of total coliforms. In contrast, higher temperatures (up to 25 °C) and blocking the UV-B portion of natural sunlight using a polyethylene terephthalate (PET) bottle increased their photoreactivation. The results of this research will provide guidance to wastewater plant operators on the potential need to minimize the level of photoreactivation in effluents before the effluents were released into receiving water bodies.

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

    PubMed

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

    2012-08-01

    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

  15. Physiology of Geobacter metallireducens under excess and limitation of electron donors. Part II. Mimicking environmental conditions during cultivation in retentostats.

    PubMed

    Marozava, Sviatlana; Röling, Wilfred F M; Seifert, Jana; Küffner, Robert; von Bergen, Martin; Meckenstock, Rainer U

    2014-06-01

    The strict anaerobe Geobacter metallireducens was cultivated in retentostats under acetate and acetate plus benzoate limitation in the presence of Fe(III) citrate in order to investigate its physiology under close to natural conditions. Growth rates below 0.003h(-1) were achieved in the course of cultivation. A nano-liquid chromatography-tandem mass spectrometry-based proteomic approach (nano-LC-MS/MS) with subsequent label-free quantification was performed on proteins extracted from cells sampled at different time points during retentostat cultivation. Proteins detected at low (0.002h(-1)) and high (0.06h(-1)) growth rates were compared between corresponding growth conditions (acetate or acetate plus benzoate). Carbon limitation significantly increased the abundances of several catabolic proteins involved in the degradation of substrates not present in the medium (ethanol, butyrate, fatty acids, and aromatic compounds). Growth rate-specific physiology was reflected in the changed abundances of energy-, chemotaxis-, oxidative stress-, and transport-related proteins. Mimicking natural conditions by extremely slow bacterial growth allowed to show how G. metallireducens optimized its physiology in order to survive in its natural habitats, since it was prepared to consume several carbon sources simultaneously and to withstand various environmental stresses.

  16. Overview of environmental and hydrogeologic conditions at Barrow, Alaska

    USGS Publications Warehouse

    McCarthy, K.A.

    1994-01-01

    To assist the Federal Aviation Administration (FAA) in evaluating the potential effects of environmental contamination at their facility in Barrow, Alaska, a general assessment was made of the hydrologic system is the vicinity of the installation. The City of Barrow is located approximately 16 kilometers southwest of Point Barrow, the northernmost point in Alaska, and therefore lies within the region of continuous permafrost. Migration of surface or shallow- subsurface chemical releases in this environ- ment would be largely restricted by near-surface permafrost to surface water and the upper, suprapermafrost zone of the subsurface. In the arctic climate and tundra terrain of the Barrow area, this shallow environment has a limited capacity to attenuate the effects of either physical disturbances or chemical contamination and is therefore highly susceptible to degradation. Esatkuat Lagoon, the present drink- ing water supply for the City of Barrow, is located approximately 2 kilometers from the FAA facility. This lagoon is the only practical source of drinking water available to the City of Barrow because alternative sources of water in the area are (1) frozen throughout most of the year, (2) insufficient in volume, (3) of poor quality, or (4) too costly to develop and distribute.

  17. Optoelectronic methods in potential application in monitoring of environmental conditions

    NASA Astrophysics Data System (ADS)

    Mularczyk-Oliwa, Monika; Bombalska, Aneta; Kwaśny, Mirosław; Kopczyński, Krzysztof; Włodarski, Maksymilian; Kaliszewski, Miron; Kostecki, Jerzy

    2016-12-01

    Allergic rhinitis, also known as hay fever is a type of inflammation which occurs when the immune system overreacts to allergens in the air. It became the most common disease among people. It became important to monitor air content for the presence of a particular type of allergen. For the purposes of environmental monitoring there is a need to widen the group of traditional methods of identification of pollen for faster and more accurate research systems. The aim of the work was the characterization and classification of certain types of plant pollens by using laser optical methods, which were supported by the chemmometrics. Several species of pollen were examined, for which a database of spectral characteristics was created, using LIF, Raman scattering and FTIR methods. Spectral database contains characteristics of both common allergens and pollen of minor importance. Based on registered spectra, statistical analysis was made, which allows the classification of the tested pollen species. For the study of the emission spectra Nd:YAG laser was used with the fourth harmonic generation (266 nm) and GaN diode laser (375 nm). For Raman scattering spectra spectrometer Nicolet IS-50 with a excitation wavelength of 1064 nm was used. The FTIR spectra, recorded in the mid infrared1 range (4000-650 cm-1) were collected with use of transmission mode (KBr pellet), ATR and DRIFT.

  18. Plasticity of Streptomyces coelicolor Membrane Composition Under Different Growth Conditions and During Development

    PubMed Central

    Sandoval-Calderón, Mario; Nguyen, Don D.; Kapono, Clifford A.; Herron, Paul; Dorrestein, Pieter C.; Sohlenkamp, Christian

    2015-01-01

    Streptomyces coelicolor is a model actinomycete that is well known for the diversity of its secondary metabolism and its complex life cycle. As a soil inhabitant, it is exposed to heterogeneous and frequently changing environmental circumstances. In the present work, we studied the effect of diverse growth conditions and phosphate depletion on its lipid profile and the relationship between membrane lipid composition and development in S. coelicolor. The lipid profile from cultures grown on solid media, which is closer to the natural habitat of this microorganism, does not resemble the previously reported lipid composition from liquid grown cultures of S. coelicolor. Wide variations were also observed across different media, growth phases, and developmental stages indicating active membrane remodeling. Ornithine lipids (OL) are phosphorus-free polar lipids that were accumulated mainly during sporulation stages, but were also major components of the membrane under phosphorus limitation. In contrast, phosphatidylethanolamine, which had been reported as one of the major polar lipids in the genus Streptomyces, is almost absent under these conditions. We identified one of the genes responsible for the synthesis of OL (SCO0921) and found that its inactivation causes the absence of OL, precocious morphological development and actinorhodin production. Our observations indicate a remarkable plasticity of the membrane composition in this bacterial species, reveal a higher metabolic complexity than expected, and suggest a relationship between cytoplasmic membrane components and the differentiation programs in S. coelicolor. PMID:26733994

  19. Interactive effects of shelter and conspecific density shape mortality, growth, and condition in juvenile reef fish.

    PubMed

    Ford, John R; Shima, Jeffrey S; Swearer, Stephen E

    2016-06-01

    How landscape context influences density-dependent processes is important, as environmental heterogeneity can confound estimates of density dependence in demographic parameters. Here we evaluate 19 populations in a shoaling temperate reef fish (Trachinops caudimaculatus) metapopulation within a heterogeneous seascape (Port Phillip Bay, Australia) to show empirically that shelter availability and population density interact to influence juvenile mortality, growth and condition. Although heterogeneity in shelter availability obscured the underlying patterns of density dependence in different ways, the combination of habitat and its interaction with density were two to six times more important than density alone in explaining variation in demographic parameters for juveniles. These findings contradict many small-scale studies and highlight the need for landscape-scale observations of how density dependence interacts with resource availability and competition to better understand how demographic parameters influence the dynamics of metapopulations in heterogeneous environments.

  20. Mechanical Characterization of Anion Exchange Membranes Under Controlled Environmental Conditions

    DTIC Science & Technology

    2015-05-11

    43 Figure 3.11 Stress-strain curve at 60°C of Nafion® 115 in both dry and wet conditions ........44 Figure 3.12 Mechanical properties of...very fine structures with low experimental error due to the utilization of very sensitive torque /normal force transducers, which are normally present on...to a competitor. 21 The humidity is maintained with a wet gas/dry gas mixture and has a dual humidity and temperature sensor for feedback

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

    PubMed

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

    2014-02-01

    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.

  2. Industry efficiency and total factor productivity growth under resources and environmental constraint in China.

    PubMed

    Tao, Feng; Li, Ling; Xia, X H

    2012-01-01

    The growth of China's industry has been seriously depending on energy and environment. This paper attempts to apply the directional distance function and the Luenberger productivity index to measure the environmental efficiency, environmental total factor productivity, and its components at the level of subindustry in China over the period from 1999 to 2009 while considering energy consumption and emission of pollutants. This paper also empirically examines the determinants of efficiency and productivity change. The major findings are as follows. Firstly, the main sources of environmental inefficiency of China's industry are the inefficiency of gross industrial output value, the excessive energy consumption, and pollutant emissions. Secondly, the highest growth rate of environmental total factor productivity among the three industrial categories is manufacturing, followed by mining, and production and supply of electricity, gas, and water. Thirdly, foreign direct investment, capital-labor ratio, ownership structure, energy consumption structure, and environmental regulation have varying degrees of effects on the environmental efficiency and environmental total factor productivity.

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

    NASA Astrophysics Data System (ADS)

    Orru, M.; Orru, H.

    2009-04-01

    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

  4. Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  5. Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions.

    PubMed

    Cook, Martha E; Croxdale, Judith G

    2003-09-01

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

  6. Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  7. Vibration-based structural health monitoring using adaptive statistical method under varying environmental condition

    NASA Astrophysics Data System (ADS)

    Jin, Seung-Seop; Jung, Hyung-Jo

    2014-03-01

    It is well known that the dynamic properties of a structure such as natural frequencies depend not only on damage but also on environmental condition (e.g., temperature). The variation in dynamic characteristics of a structure due to environmental condition may mask damage of the structure. Without taking the change of environmental condition into account, false-positive or false-negative damage diagnosis may occur so that structural health monitoring becomes unreliable. In order to address this problem, an approach to construct a regression model based on structural responses considering environmental factors has been usually used by many researchers. The key to success of this approach is the formulation between the input and output variables of the regression model to take into account the environmental variations. However, it is quite challenging to determine proper environmental variables and measurement locations in advance for fully representing the relationship between the structural responses and the environmental variations. One alternative (i.e., novelty detection) is to remove the variations caused by environmental factors from the structural responses by using multivariate statistical analysis (e.g., principal component analysis (PCA), factor analysis, etc.). The success of this method is deeply depending on the accuracy of the description of normal condition. Generally, there is no prior information on normal condition during data acquisition, so that the normal condition is determined by subjective perspective with human-intervention. The proposed method is a novel adaptive multivariate statistical analysis for monitoring of structural damage detection under environmental change. One advantage of this method is the ability of a generative learning to capture the intrinsic characteristics of the normal condition. The proposed method is tested on numerically simulated data for a range of noise in measurement under environmental variation. A comparative

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

    PubMed

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

    2011-10-01

    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 Ostojićevo (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.

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

    PubMed

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

    2007-07-01

    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.

  10. Effects of environmental stress on the condition of Littorina littorea along the Scheldt estuary (The Netherlands).

    PubMed

    Van den Broeck, Heidi; De Wolf, Hans; Backeljau, Thierry; Blust, Ronny

    2007-04-15

    The condition of the periwinkle Littorina littorea, expressed in terms of its shell morphology, reproductive impairment (i.e. female sterility/intersex, male penis shedding), trematode infestation load, lipid reserves and dry/wet weight ratio, was determined in function of environmental stress along the polluted Western and relatively clean Eastern Scheldt estuary (The Netherlands). The upstream increasing pollution and decreasing salinity levels along the Western Scheldt estuary (Fig. 1) are reflected in the dry/wet weight ratio and lipid content of the periwinkles. Compared to the Eastern Scheldt, female intersex (i.e. indicator of TBT pollution) and sterility occurred more frequently in the Western Scheldt estuary, while male penis shedding was even restricted to the latter estuary. The highest population intersex and sterility incidence was found near the harbour of Vlissingen and reflects potential nautical activities. The number of trematode infested periwinkles did not differ between both estuaries, although local sampling site differences were detected within each estuary, reflecting the complex interactions that exist among parasites, hosts and the local environment. Finally, both estuaries were maximally discriminated from each other based on the shell weight of the periwinkles using a canonical discriminant analysis. Periwinkles with the heaviest shells were found in the Western Scheldt estuary and may reflect growth rate or structural population differences caused by the less favourable living conditions in the Western Scheldt estuary.

  11. Rift Valley Fever Outbreaks in Mauritania and Related Environmental Conditions

    PubMed Central

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

    2014-01-01

    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

  12. The stability of collected human scent under various environmental conditions.

    PubMed

    Hudson, Davia T; Curran, Allison M; Furton, Kenneth G

    2009-11-01

    Human scent evidence collected from objects at a crime scene is used for scent discrimination with specially trained canines. Storage of the scent evidence is usually required yet no optimized storage protocol has been determined. Storage containers including glass, polyethylene, and aluminized pouches were evaluated to determine the optimal medium for storing human scent evidence of which glass was determined to be the optimal storage matrix. Hand odor samples were collected on three different sorbent materials, sealed in glass vials and subjected to different storage environments including room temperature, -80 degrees C conditions, dark storage, and UVA/UVB light exposure over a 7-week period. Volatile organic compounds (VOCs) in the headspace of the samples were extracted and identified using solid-phase micro-extraction-gas chromatography/mass spectrometry (SPME-GC/MS). Three-dimensional covariance mapping showed that glass containers subjected to minimal UVA/UVB light exposure provide the most stable environment for stored human scent samples.

  13. Corrosion behavior of carbon steels under tuff repository environmental conditions

    SciTech Connect

    McCright, R.D.; Weiss, H.

    1984-10-01

    Carbon steels may be used for borehole liners in a potential high-level nuclear waste repository in tuff in Nevada. Borehole liners are needed to facilitate emplacement of the waste packages and to facilitate retrieval of the packages, if required. Corrosion rates of low carbon structural steels AISI 1020 and ASTM A-36 were determined in J-13 well water and in saturated steam at 100{sup 0}C. Tests were conducted in air-sparged J-13 water to attain more oxidizing conditions representative of irradiated aqueous environments. A limited number of irradiation corrosion and stress corrosion tests were performed. Chromium-molybdenum alloy steels and cast irons were also tested. These materials showed lower general corrosion but were susceptible to stress corrosion cracking when welded. 4 references, 4 tables.

  14. Mechanisms of environmental chemicals that enable the cancer hallmark of evasion of growth suppression

    PubMed Central

    Nahta, Rita; Al-Mulla, Fahd; Al-Temaimi, Rabeah; Amedei, Amedeo; Andrade-Vieira, Rafaela; Bay, Sarah; G. Brown, Dustin; Calaf, Gloria M.; Castellino, Robert C.; Cohen-Solal, Karine A.; Colacci, Annamaria; Cruickshanks, Nichola; Dent, Paul; Di Fiore, Riccardo; Forte, Stefano; Goldberg, Gary S.; Hamid, Roslida A.; Krishnan, Harini; Laird, Dale W.; Lasfar, Ahmed; Marignani, Paola A.; Memeo, Lorenzo; Mondello, Chiara; Naus, Christian C.; Ponce-Cusi, Richard; Raju, Jayadev; Roy, Debasish; Roy, Rabindra; P. Ryan, Elizabeth; Salem, Hosni K.; Scovassi, A. Ivana; Singh, Neetu; Vaccari, Monica; Vento, Renza; Vondráček, Jan; Wade, Mark; Woodrick, Jordan; Bisson, William H.

    2015-01-01

    As part of the Halifax Project, this review brings attention to the potential effects of environmental chemicals on important molecular and cellular regulators of the cancer hallmark of evading growth suppression. Specifically, we review the mechanisms by which cancer cells escape the growth-inhibitory signals of p53, retinoblastoma protein, transforming growth factor-beta, gap junctions and contact inhibition. We discuss the effects of selected environmental chemicals on these mechanisms of growth inhibition and cross-reference the effects of these chemicals in other classical cancer hallmarks. PMID:26106139

  15. Deformation and crack growth response under cyclic creep conditions

    SciTech Connect

    Brust, F.W. Jr.

    1995-12-31

    To increase energy efficiency, new plants must operate at higher and higher temperatures. Moreover, power generation equipment continues to age and is being used far beyond its intended original design life. Some recent failures which unfortunately occurred with serious consequences have clearly illustrated that current methods for insuring safety and reliability of high temperature equipment is inadequate. Because of these concerns, an understanding of the high-temperature crack growth process is very important and has led to the following studies of the high temperature failure process. This effort summarizes the results of some recent studies which investigate the phenomenon of high temperature creep fatigue crack growth. Experimental results which detail the process of creep fatigue, analytical studies which investigate why current methods are ineffective, and finally, a new approach which is based on the T{sup *}-integral and its ability to characterize the creep-fatigue crack growth process are discussed. The potential validity of this new predictive methodology is illustrated.

  16. Sustainable Environmental Education: Conditions and Characteristics Needed for a Successfully Integrated Program in Public Elementary Schools

    NASA Astrophysics Data System (ADS)

    Rieckenberg, Cara Rae

    This case study investigated what conditions and characteristics contributed to a successful environmental education program within elementary schools of a school district where environmental education was the mandate. While research does exist on practical application of environmental education within schools, little if any literature has been written or research conducted on schools actually implementing environmental education to study what contributes to the successful implementation of the program. To study this issue, 24 participants from a Midwestern school district were interviewed, six of whom were principals of each of the six elementary schools included in the study. All participants were identified as champions of environmental education integration within their buildings due to leadership positions held focused on environmental education. Analysis of the data collected via interviews revealed findings that hindered the implementation of environmental education, findings that facilitated the implementation of environmental education, and findings that indicated an environmental education-focused culture existed within the schools. Conditions and characteristics found to contribute to the success of these school's environmental education programs include: professional development opportunities, administrative support, peer leadership opportunities and guidance, passion with the content and for the environment, comfort and confidence with the content, ease of activities and events that contribute to the culture and student success. Keywords: environmental education, integration, leadership, teachers as leaders.

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

    PubMed

    Kwon, Young-Ju; Park, Mi-Jeong; Kim, Sang-Gyu; Baldwin, Ian T; Park, Chung-Mo

    2014-05-19

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

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

    PubMed Central

    2014-01-01

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

  19. Growth of juvenile Arctica islandica under experimental conditions

    NASA Astrophysics Data System (ADS)

    Witbaard, R.; Franken, R.; Visser, B.

    1998-02-01

    In two laboratory experiments, the effects of temperature and food availability on the growth of 10- to 23-mm high specimens of the bivalve Arctica islandica were estimated. Each experimental set-up consisted of 5 treatments in which either the food supply or the temperature differed. It was demonstrated that Arctica is able to grow at temperatures as low as 1°C. A tenfold increase of shell growth was observed at temperatures between 1° and 12°C. The greatest change in growth rate took place between 1° and 6°C. Average instantaneous shell growth varies between 0.0003 at 1°C to 0.0032/day at 12°C. The results suggest that temperature hardly affects the time spent in filtration, whereas particle density strongly influences that response. Starved animals at 9°C have their siphons open during only 12% of the time, whereas the siphons of optimally fed animals were open on average during 76% of the observations. Increased siphon activity corresponded to high shell and tissue growth. At 9°C, average shell growth at the optimum cell density of 20×106 cell/l was 3.1 mm corresponding to an instantaneous rate of 0.0026/day. An algal cell density ( Isochrysis galbana, Dunaliella marina) ranging between 5 and 7×106 cell/l is just enough to keep shells alive at 9°C. Carbon conversion efficiency at 9°C is estimated to vary between 11 and 14%.

  20. Relationships among fisheries exploitation, environmental conditions, and ecological indicators across a series of marine ecosystems

    NASA Astrophysics Data System (ADS)

    Fu, Caihong; Large, Scott; Knight, Ben; Richardson, Anthony J.; Bundy, Alida; Reygondeau, Gabriel; Boldt, Jennifer; van der Meeren, Gro I.; Torres, Maria A.; Sobrino, Ignacio; Auber, Arnaud; Travers-Trolet, Morgane; Piroddi, Chiara; Diallo, Ibrahima; Jouffre, Didier; Mendes, Hugo; Borges, Maria Fatima; Lynam, Christopher P.; Coll, Marta; Shannon, Lynne J.; Shin, Yunne-Jai

    2015-08-01

    Understanding how external pressures impact ecosystem structure and functioning is essential for ecosystem-based approaches to fisheries management. We quantified the relative effects of fisheries exploitation and environmental conditions on ecological indicators derived from two different data sources, fisheries catch data (catch-based) and fisheries independent survey data (survey-based) for 12 marine ecosystems using a partial least squares path modeling approach (PLS-PM). We linked these ecological indicators to the total biomass of the ecosystem. Although the effects of exploitation and environmental conditions differed across the ecosystems, some general results can be drawn from the comparative approach. Interestingly, the PLS-PM analyses showed that survey-based indicators were less tightly associated with each other than the catch-based ones. The analyses also showed that the effects of environmental conditions on the ecological indicators were predominantly significant, and tended to be negative, suggesting that in the recent period, indicators accounted for changes in environmental conditions and the changes were more likely to be adverse. Total biomass was associated with fisheries exploitation and environmental conditions; however its association with the ecological indicators was weak across the ecosystems. Knowledge of the relative influence of exploitation and environmental pressures on the dynamics within exploited ecosystems will help us to move towards ecosystem-based approaches to fisheries management. PLS-PM proved to be a useful approach to quantify the relative effects of fisheries exploitation and environmental conditions and suggest it could be used more widely in fisheries oceanography.

  1. EVALUATION OF WASTE PACKAGE EXTERNAL ENVIRONMENTAL CONDITION STUDY

    SciTech Connect

    E. N. Lindner and E. F. Dembowski

    1998-07-23

    The U. S. Department of Energy (DOE) is studying Yucca Mountain as the possible site for a permanent underground repository for disposal of spent nuclear fuel (SNF) and other high-level waste (HLW). The emplacement of high-level radioactive waste in Yucca Mountain will release a large amount of heat into the rock above and below the repository. Due to this heat, the rock temperature will rise, and then decrease when the production of decay heat falls below the rate at which heat escapes from the hot zone. In addition to raising the rock temperature, the heat will vaporize water, which will condense in cooler regions. The condensate water may drain back toward the emplacement drifts or it may ''shed'' through the pillars between emplacement drifts. Other effects, such as coupled chemical and mechanical processes, may influence the movement of water above, within, and below the emplacement drifts. This study examined near field environmental parameters that could have an effect on the waste package, including temperature, humidity, seepage rate, pH of seepage, chemistry (dissolved salts/minerals) of seepage, composition of drift atmosphere, colloids, and biota. This report is a Type I analysis performed in support of the development of System Description Documents (SDDs). A Type I analysis is a quantitative or qualitative analysis that may fulfill any of a variety of purposes associated with the Monitored Geologic Repository (MGR), other than providing direct analytical support for design output documents. A Type I analysis may establish design input, as defined in the ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998). This study establishes a technical basis for emplacement drift (i.e. at the waste package surface) environment criteria to be considered in the development of the waste package design. The information will support development of several SDDs and resolve emplacement drift external environment questions in the criteria of those

  2. Environmental Influences on Kelp Performance across the Reproductive Period: An Ecological Trade-Off between Gametophyte Survival and Growth?

    PubMed Central

    Mohring, Margaret B.; Kendrick, Gary A.; Wernberg, Thomas; Rule, Michael J.; Vanderklift, Mathew A.

    2013-01-01

    Most kelps (order Laminariales) exhibit distinct temporal patterns in zoospore production, gametogenesis and gametophyte reproduction. Natural fluctuations in ambient environmental conditions influence the intrinsic characteristics of gametes, which define their ability to tolerate varied conditions. The aim of this work was to document seasonal patterns in reproduction and gametophyte growth and survival of Ecklonia radiata (C. Agardh) J. Agardh in south-western Australia. These results were related to patterns in local environmental conditions in an attempt to ascertain which factors explain variation throughout the season. E. radiata was fertile (produced zoospores) for three and a half months over summer and autumn. Every two weeks during this time, gametophytes were grown in a range of temperatures (16–22°C) in the laboratory. Zoospore densities were highly variable among sample periods; however, zoospores released early in the season produced gametophytes which had greater rates of growth and survival, and these rates declined towards the end of the reproductive season. Growth rates of gametophytes were positively related to day length, with the fastest growing recruits released when the days were longest. Gametophytes consistently survived best in the lowest temperature (16°C), yet exhibited optimum growth in higher culture temperatures (20–22°C). These results suggest that E. radiata releases gametes when conditions are favourable for growth, and E. radiata gametophytes are tolerant of the range of temperatures observed at this location. E. radiata releases the healthiest gametophytes when day length and temperature conditions are optimal for better germination, growth, and sporophyte production, perhaps as a mechanism to help compete against other species for space and other resources. PMID:23755217

  3. Environmental influences on kelp performance across the reproductive period: an ecological trade-off between gametophyte survival and growth?

    PubMed

    Mohring, Margaret B; Kendrick, Gary A; Wernberg, Thomas; Rule, Michael J; Vanderklift, Mathew A

    2013-01-01

    Most kelps (order Laminariales) exhibit distinct temporal patterns in zoospore production, gametogenesis and gametophyte reproduction. Natural fluctuations in ambient environmental conditions influence the intrinsic characteristics of gametes, which define their ability to tolerate varied conditions. The aim of this work was to document seasonal patterns in reproduction and gametophyte growth and survival of Ecklonia radiata (C. Agardh) J. Agardh in south-western Australia. These results were related to patterns in local environmental conditions in an attempt to ascertain which factors explain variation throughout the season. E. radiata was fertile (produced zoospores) for three and a half months over summer and autumn. Every two weeks during this time, gametophytes were grown in a range of temperatures (16-22 °C) in the laboratory. Zoospore densities were highly variable among sample periods; however, zoospores released early in the season produced gametophytes which had greater rates of growth and survival, and these rates declined towards the end of the reproductive season. Growth rates of gametophytes were positively related to day length, with the fastest growing recruits released when the days were longest. Gametophytes consistently survived best in the lowest temperature (16 °C), yet exhibited optimum growth in higher culture temperatures (20-22 °C). These results suggest that E. radiata releases gametes when conditions are favourable for growth, and E. radiata gametophytes are tolerant of the range of temperatures observed at this location. E. radiata releases the healthiest gametophytes when day length and temperature conditions are optimal for better germination, growth, and sporophyte production, perhaps as a mechanism to help compete against other species for space and other resources.

  4. New insights from coral growth band studies in an era of rapid environmental change

    NASA Astrophysics Data System (ADS)

    Lough, Janice M.; Cooper, Timothy F.

    2011-10-01

    The rapid formation of calcium carbonate coral skeletons (calcification) fuelled by the coral-algal symbiosis is the backbone of tropical coral reef ecosystems. However, the efficacy of calcification is measurably influenced by the sea's physico-chemical environment, which is changing rapidly. Warming oceans have already led to increased frequency and severity of coral bleaching, and ocean acidification has a demonstrable potential to cause reduced rates of calcification. There is now general agreement that ocean warming and acidification are attributable to human activities increasing greenhouse gas concentrations in the atmosphere, and the large part of the extra carbon dioxide (the main greenhouse gas) that is absorbed by oceans. Certain massive corals provide historical perspectives on calcification through the presence of dateable annual density banding patterns. Each band is a page in an environmental archive that reveals past responses of growth (linear extension, skeletal density and calcification rate) and provides a basis for prediction of future of coral growth. A second major line of research focuses on the measurement of various geochemical tracers incorporated into the growth bands, allowing the reconstruction of past marine climate conditions (i.e. palaeoclimatology). Here, we focus on the structural properties of the annual density bands themselves (viz. density; linear extension), exploring their utility in providing both perspectives on the past and pointers to the future of calcification on coral reefs. We conclude that these types of coral growth records, though relatively neglected in recent years compared to the geochemical studies, remain immensely valuable aids to unravelling the consequences of anthropogenic climate change on coral reefs. Moreover, an understanding of coral growth processes is an essential pre-requisite for proper interpretation of studies of geochemical tracers in corals.

  5. Relation between height growth of larch seedlings and weather conditions

    Treesearch

    D. R. Brewster

    1918-01-01

    It is a common experience in passing through stands of coniferous seedlings ten to thirty feet tall to notice the rapidly growing leaders of the dominant trees. A casual glance will show a surprising variation in the rate of height growth of the same tree in different years. The obvious explanation that occurs to one is that this variation is clue to a corresponding...

  6. Cross-continent comparisons reveal differing environmental drivers of growth of the coral reef fish, Lutjanus bohar

    NASA Astrophysics Data System (ADS)

    Ong, Joyce J. L.; Rountrey, Adam N.; Marriott, Ross J.; Newman, Stephen J.; Meeuwig, Jessica J.; Meekan, Mark G.

    2017-03-01

    Biochronologies provide important insights into the growth responses of fishes to past variability in physical and biological environments and, in so doing, allow modelling of likely responses to climate change in the future. We examined spatial variability in the key drivers of inter-annual growth patterns of a widespread, tropical snapper, Lutjanus bohar, at similar tropical latitudes on the north-western and north-eastern coasts of the continent of Australia. For this study, we developed biochronologies from otoliths that provided proxies of somatic growth and these were analysed using mixed-effects models to examine the historical drivers of growth. Our analyses demonstrated that growth patterns of fish were driven by different climatic and biological factors in each region, including Pacific Ocean climate indices, regional sea level and the size structure of the fish community. Our results showed that the local oceanographic and biological context of reef systems strongly influenced the growth of L. bohar and that a single age-related growth trend cannot be assumed for separate populations of this species that are likely to experience different environmental conditions. Generalised predictions about the growth response of fishes to climate change will thus require adequate characterisation of the spatial variability in growth determinants likely to be found throughout the range of species that have cosmopolitan distributions.

  7. Temperature governs the inactivation rate of vegetative bacteria under growth-preventing conditions.

    PubMed

    Ross, Tom; Zhang, Donglai; McQuestin, Olivia J

    2008-11-30

    Novel studies, in combination with a meta-analysis of available data, were undertaken to explore the kinetics of non-thermal inactivation of Escherichia coli with particular attention to inactivation in fermented meats and including analogous broth-based model systems. The analyses were based on rates of inactivation and specifically investigated the influence of temperature, pH and water activity at levels that alone, or in combination, prevented growth. When independently-derived inactivation data, obtained using different test conditions and diverse E. coli strains, were presented as Arrhenius plots, temperature was found to have a strong effect on the rate of inactivation, explaining 60% of the variance in the data. The slope of the Arrhenius plot changed, however, at temperatures above approximately 47 degrees C, corresponding to the maximum for growth of E. coli. A strong and consistent effect of pH or water activity on inactivation rate was not observed upon meta-analysis of collated data, but the relative effect of both factors was quantified in an analogous broth-based system. We also observed that inactivation rates of three strains of Listeria monocytogenes in the range 5 to 40 degrees C did not differ systematically from those of four strains of E. coli when growth was prevented by low pH and water activity. The observations of a consistent slope of Arrhenius plots for non-thermal inactivation rate of bacteria under diverse environmental conditions and for different strains and species, but which differ from slopes associated with thermal inactivation, raise the intriguing possibility of a mechanism of inactivation at sub-lethal temperatures, distinct from thermal inactivation, that is common to many vegetative bacteria.

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

    EPA Science Inventory

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

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

    ERIC Educational Resources Information Center

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

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

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

    ERIC Educational Resources Information Center

    Hill, Grant; Hulbert, George

    2007-01-01

    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…

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

    ERIC Educational Resources Information Center

    Hill, Grant; Hulbert, George

    2007-01-01

    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…

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

    EPA Science Inventory

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

  13. EMAP and other tools for measuring biodiversity, habitat conditions, and environmental trends

    Treesearch

    Eric M. Preston; Christine A. Ribic

    1993-01-01

    We describe research efforts that contribute to assessment and monitoring of neotropical migratory birds, including: I) use of neotropical migrants in the Environmental Monitoring and Assessment Program (EMAP) as potential indicators of general environmental condition and biodiversity; 2) EPA's Habitat/Biodiversity Research Initiative to assess comparative risks...

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

    PubMed

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

    2014-09-01

    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. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  15. Environmentally Sensitive Area (ESA) Grant Condition Waiver Program in Region 2

    EPA Pesticide Factsheets

    Starting in October 1979, EPA Region 2 applied a special condition to many wastewater facilities’ construction grants (see Federal Register, Vol. 43, No. 188, September 27, 1978) to protect Environmentally Sensitive Areas(EASs) from induced development.

  16. Environmental Conditions in the Gulf of Mexico during November-December

    DTIC Science & Technology

    1990-10-01

    The purpose of this technical note is to describe some of the environmental conditions in a region of the Gulf of Mexico in which an experiment will take place in November and December 1990. The general area

  17. 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...

  18. Differential Carbohydrate Recognition by Campylobacter jejuni Strain 11168: Influences of Temperature and Growth Conditions

    PubMed Central

    Day, Christopher J.; Tiralongo, Joe; Hartnell, Regan D.; Logue, Carie-Anne; Wilson, Jennifer C.; von Itzstein, Mark; Korolik, Victoria

    2009-01-01

    The pathogenic clinical strain NCTC11168 was the first Campylobacter jejuni strain to be sequenced and has been a widely used laboratory model for studying C. jejuni pathogenesis. However, continuous passaging of C. jejuni NCTC11168 has been shown to dramatically affect its colonisation potential. Glycan array analysis was performed on C. jejuni NCTC11168 using the frequently passaged, non-colonising, genome sequenced (11168-GS) and the infrequently passaged, original, virulent (11168-O) isolates grown or maintained under various conditions. Glycan structures recognised and bound by C. jejuni included terminal mannose, N-acetylneuraminic acid, galactose and fucose. Significantly, it was found that only when challenged with normal oxygen at room temperature did 11168-O consistently bind to sialic acid or terminal mannose structures, while 11168-GS bound these structures regardless of growth/maintenance conditions. Further, binding of un-capped galactose and fucosylated structures was significantly reduced when C. jejuni was maintained at 25°C under atmospheric oxygen conditions. These binding differences identified through glycan array analysis were confirmed by the ability of specific lectins to competitively inhibit the adherence of C. jejuni to a Caco-2 intestinal cell line. Our data suggests that the binding of mannose and/or N-acetylneuraminic acid may provide the initial interactions important for colonisation following environmental exposure. PMID:19290056

  19. Maryland`s environmental export programs: Supporting job growth through environmental protection

    SciTech Connect

    Chiu, K.S.; O`Neill, P.G.

    1996-12-31

    Although a relatively small state with less than 6 million residents, Maryland is home to some 400 environmental products and services companies. These companies range in size from less than $1 million to more than $100 million in annual revenue. They include both manufacturing companies and consultants, covering many aspects of air, water and waste management, serving government and industry needs throughout the world. Maryland`s annual share of the market for environmental goods and services has been estimated at over $2 billion. Many of Maryland`s environmental technology companies play some part in limiting the environmental impact on one of the State`s greatest natural resources, the Chesapeake Bay. Maryland believes that economic development and environmental protection are mutually enforcing goals. The State strives to improve both in order to improve quality of life. Maryland recognizes that environmental protection creates jobs. The business environment in Maryland has created a climate for environmental companies to thrive, including those that export abroad. Due to the prevalence of environmental businesses in the State and the growing need for environmental management overseas, environmental technology became one of Maryland`s target export sectors under a recently unveiled strategic plan for international business in the State.

  20. The international growth standard for children and adolescents project: environmental influences on preadolescent and adolescent growth in weight and height.

    PubMed

    Ulijaszek, Stanley J

    2006-12-01

    This review has two aims. The first is to identify important environmental influences on the growth of children aged 1 to 9 years and of adolescents, defined as those aged 10 to 19 years. The second is to identify possible environmentally based criteria for the selection of individuals and populations for data collection in the development of an international growth reference for these age ranges. There are many common environmental influences on the growth of children between the ages of 1 and 19 years; the examination and description of these forms the main body of this review. Subsequently, environmental factors influencing adolescent growth only are considered. In both cases, possible selection criteria are put forward. The most important inclusion criteria for both preadolescence and adolescence are good nutrition, lack of infection, and socioeconomic status that does not constrain growth. Additionally, low birthweight, catchup growth, breastfeeding, and early adiposity rebound have impacts on growth and/or body composition into puberty. Exclusion of children born at low birth and/or experiencing catch-up growth could be most realistically operationalized if populations in which secular trends in growth were either completed or minimal were selected. Although an effect of hypoxia on child and adolescent growth, independent of nutrition, is small at most, many high-altitude populations have high prevalances of low birthweight and should be excluded on this basis. Since all populations are exposed to pollutants, contaminants, and toxicants in varying degrees, they cannot be realistically excluded from the sample frame. However, it may be desirable to exclude populations that are habitually exposed to extremely high levels of environmental pollution, including air pollution, and those living in close proximity to toxic waste. It is impossible to exclude populations and individuals on the basis of their exposure to aflatoxin contamination of food. However

  1. Influence of growth conditions on bacteriocin production by Brevibacterium linens.

    PubMed

    Motta, A S; Brandelli, A

    2003-08-01

    The influence of temperature, NaCl concentration and cheese whey media on growth of Brevibacterium linens ATCC 9175 and production of bacteriocin-like antimicrobial activity was studied. Bacteriocin production and activity were higher at 25 degrees C than at 30 degrees C. No significant growth or production of bacteriocins was observed at 37 degrees C. When bacteriocin production was investigated in media containing different concentrations of NaCl, increased activity was observed in media containing 40 or 80 g l(-1), but not 120 g l(-1) NaCl. The addition of NaCl resulted in a significant increase in specific production rates of bacteriocin-like activity. Antimicrobial activity was also observed by cultivation of B. linens at 25 degrees C in cheese whey media.

  2. Does spatial variation in environmental conditions affect recruitment? A study using a 3-D model of Peruvian anchovy

    NASA Astrophysics Data System (ADS)

    Xu, Yi; Rose, Kenneth A.; Chai, Fei; Chavez, Francisco P.; Ayón, Patricia

    2015-11-01

    We used a 3-dimensional individual-based model (3-D IBM) of Peruvian anchovy to examine how spatial variation in environmental conditions affects larval and juvenile growth and survival, and recruitment. Temperature, velocity, and phytoplankton and zooplankton concentrations generated from a coupled hydrodynamic Nutrients-Phytoplankton-Zooplankton-Detritus (NPZD) model, mapped to a three dimensional rectangular grid, were used to simulate anchovy populations. The IBM simulated individuals as they progressed from eggs to recruitment at 10 cm. Eggs and yolk-sac larvae were followed hourly through the processes of development, mortality, and movement (advection), and larvae and juveniles were followed daily through the processes of growth, mortality, and movement (advection plus behavior). A bioenergetics model was used to grow larvae and juveniles. The NPZD model provided prey fields which influence both food consumption rate as well as behavior mediated movement with individuals going to grids cells having optimal growth conditions. We compared predicted recruitment for monthly cohorts for 1990 through 2004 between the full 3-D IBM and a point (0-D) model that used spatially-averaged environmental conditions. The 3-D and 0-D versions generated similar interannual patterns in monthly recruitment for 1991-2004, with the 3-D results yielding consistently higher survivorship. Both versions successfully captured the very poor recruitment during the 1997-1998 El Niño event. Higher recruitment in the 3-D simulations was due to higher survival during the larval stage resulting from individuals searching for more favorable temperatures that lead to faster growth rates. The strong effect of temperature was because both model versions provided saturating food conditions for larval and juvenile anchovies. We conclude with a discussion of how explicit treatment of spatial variation affected simulated recruitment, other examples of fisheries modeling analyses that have used a

  3. Jensen's Inequality and the Impact of Short-Term Environmental Variability on Long-Term Population Growth Rates.

    PubMed

    Pickett, Evan J; Thomson, David L; Li, Teng A; Xing, Shuang

    2015-01-01

    It is well established in theory that short-term environmental fluctuations could affect the long-term growth rates of wildlife populations, but this theory has rarely been tested and there remains little empirical evidence that the effect is actually important in practice. Here we develop models to quantify the effects of daily, seasonal, and yearly temperature fluctuations on the average population growth rates, and we apply them to long-term data on the endangered Black-faced Spoonbill (Platalea minor); an endothermic species whose population growth rates follow a concave relationship with temperature. We demonstrate for the first time that the current levels of temperature variability, particularly seasonal variability, are already large enough to substantially reduce long-term population growth rates. As the climate changes, our results highlight the importance of considering the ecological effects of climate variability and not just average conditions.

  4. Jensen’s Inequality and the Impact of Short-Term Environmental Variability on Long-Term Population Growth Rates

    PubMed Central

    Pickett, Evan J.; Thomson, David L.; Li, Teng A.; Xing, Shuang

    2015-01-01

    It is well established in theory that short-term environmental fluctuations could affect the long-term growth rates of wildlife populations, but this theory has rarely been tested and there remains little empirical evidence that the effect is actually important in practice. Here we develop models to quantify the effects of daily, seasonal, and yearly temperature fluctuations on the average population growth rates, and we apply them to long-term data on the endangered Black-faced Spoonbill (Platalea minor); an endothermic species whose population growth rates follow a concave relationship with temperature. We demonstrate for the first time that the current levels of temperature variability, particularly seasonal variability, are already large enough to substantially reduce long-term population growth rates. As the climate changes, our results highlight the importance of considering the ecological effects of climate variability and not just average conditions. PMID:26352857

  5. Preliminary evaluation of environmental variables affecting diameter growth of individual hardwoods in the Southern Appalachian Mountains

    Treesearch

    W. Henry McNab; F. Thomas Lloyd

    2001-01-01

    The value of environmental variables as measures of site quality for individual tree growth models was determined for 12 common species of eastern hardwoods in the Southern Appalachian Mountains. Periodic diameter increment was modeled as a function of size, competition and environmental variables for 1,381 trees in even-aged stands of mixed-species. Resulting species...

  6. Environmental Factors Associated with the Growth of Chinese Literary Genius: A Test of Rogerian Assumption.

    ERIC Educational Resources Information Center

    Kuo, You-Yuk

    1987-01-01

    This study explored relationships between environmental factors (era, standard of living, freedom, and value) and the growth of Chinese literary genius. Using a new measure, the Chinese Creator Rating Scale, the study found that historical top scorers had above average values on the four environmental factors, supporting the humanistic theory of…

  7. Fermentation and proteome profiles of Lactobacillus plantarum strains during growth under food-like conditions.

    PubMed

    Siragusa, Sonya; De Angelis, Maria; Calasso, Maria; Campanella, Daniela; Minervini, Fabio; Di Cagno, Raffaella; Gobbetti, Marco

    2014-01-16

    This study aimed at investigating the proteomic adaptation of Lactobacillus plantarum strains. Cultivation of L. plantarum strains under food-like conditions (wheat flour hydrolyzed, whey milk, tomato juice) affected some metabolic traits (e.g., consumption of carbohydrates and synthesis of organic acids) compared to de Man, Rogosa and Sharpe (MRS) broth. The analysis of the fermentation profile showed that the highest number of carbon sources metabolized by L. plantarum strains was found using cells cultivated in media containing low concentration of glucose or no glucose at all. The proteomic maps of the strains were comparatively determined after growth on MRS broth and under food-like conditions. The amount of proteins depended on strain and, especially, on culture conditions. Proteins showing decreased or increased amounts under food-like conditions were identified using MALDI-TOF-MS/MS or LC-nano-ESI-MS/MS. Changes of the proteome concerned proteins that are involved in carbohydrate transport and metabolism, energy metabolism, Sec-dependent secretion system, stress response, nucleotide metabolism, regulation of nitrogen metabolism, and protein biosynthesis. A catabolic repression by glucose on carbohydrate transport and metabolism was also found. The characterization of the proteomes in response to changing environmental conditions could be useful to get L. plantarum strains adapted for specific applications. Microbial cell performance during food biotechnological processes has become one of the greatest concerns all over the world. L. plantarum is a lactic acid bacterium with a large industrial application for fermented foods or functional foods (e.g., probiotics). The present study compared the fermentation and proteomic profiling of L. plantarum strains during growth under food-like conditions and under optimal laboratory conditions (MRS broth). This study provides specific mechanisms of proteomic adaptation involved in the microbial performances

  8. Changes in the Cytoplasmic Composition of Amino Acids and Proteins Observed in Staphylococcus aureus during Growth under Variable Growth Conditions Representative of the Human Wound Site

    PubMed Central

    Alreshidi, Mousa M.; Dunstan, R. Hugh; Gottfries, Johan; Macdonald, Margaret M.; Crompton, Marcus J.; Ang, Ching-Seng; Williamson, Nicholas A.; Roberts, Tim K.

    2016-01-01

    Staphylococcus aureus is an opportunistic pathogen responsible for a high proportion of nosocomial infections. This study was conducted to assess the bacterial responses in the cytoplasmic composition of amino acids and ribosomal proteins under various environmental conditions designed to mimic those on the human skin or within a wound site: pH6-8, temperature 35–37°C, and additional 0–5% NaCl. It was found that each set of environmental conditions elicited substantial adjustments in cytoplasmic levels of glutamic acid, aspartic acid, proline, alanine and glycine (P< 0.05). These alterations generated characteristic amino acid profiles assessed by principle component analysis (PCA). Substantial alterations in cytoplasmic amino acid and protein composition occurred during growth under conditions of higher salinity stress implemented via additional levels of NaCl in the growth medium. The cells responded to additional NaCl at pH 6 by reducing levels of ribosomal proteins, whereas at pH 8 there was an upregulation of ribosomal proteins compared with the reference control. The levels of two ribosomal proteins, L32 and S19, remained constant across all experimental conditions. The data supported the hypothesis that the bacterium was continually responding to the dynamic environment by modifying the proteome and optimising metabolic homeostasis. PMID:27442022

  9. Changes in the Cytoplasmic Composition of Amino Acids and Proteins Observed in Staphylococcus aureus during Growth under Variable Growth Conditions Representative of the Human Wound Site.

    PubMed

    Alreshidi, Mousa M; Dunstan, R Hugh; Gottfries, Johan; Macdonald, Margaret M; Crompton, Marcus J; Ang, Ching-Seng; Williamson, Nicholas A; Roberts, Tim K

    2016-01-01

    Staphylococcus aureus is an opportunistic pathogen responsible for a high proportion of nosocomial infections. This study was conducted to assess the bacterial responses in the cytoplasmic composition of amino acids and ribosomal proteins under various environmental conditions designed to mimic those on the human skin or within a wound site: pH6-8, temperature 35-37°C, and additional 0-5% NaCl. It was found that each set of environmental conditions elicited substantial adjustments in cytoplasmic levels of glutamic acid, aspartic acid, proline, alanine and glycine (P< 0.05). These alterations generated characteristic amino acid profiles assessed by principle component analysis (PCA). Substantial alterations in cytoplasmic amino acid and protein composition occurred during growth under conditions of higher salinity stress implemented via additional levels of NaCl in the growth medium. The cells responded to additional NaCl at pH 6 by reducing levels of ribosomal proteins, whereas at pH 8 there was an upregulation of ribosomal proteins compared with the reference control. The levels of two ribosomal proteins, L32 and S19, remained constant across all experimental conditions. The data supported the hypothesis that the bacterium was continually responding to the dynamic environment by modifying the proteome and optimising metabolic homeostasis.

  10. Modelling the growth/no growth boundary of Zygosaccharomyces bailii in acidic conditions: a contribution to the alternative method to preserve foods without using chemical preservatives.

    PubMed

    Dang, T D T; Mertens, L; Vermeulen, A; Geeraerd, A H; Van Impe, J F; Debevere, J; Devlieghere, F

    2010-01-31

    The aim of the study was to develop mathematical models describing growth/no growth (G/NG) boundaries of the highly resistant food spoilage yeast-Zygosaccharomyces bailii-in different environmental conditions, taking acidified sauces as the target product. By applying these models, the stability of products with characteristics within the investigated pH, a(w) and acetic acid ranges can be evaluated. Besides, the well-defined no growth regions can be used in the development of guidelines regarding formulation of new shelf-stable foods without using chemical preservatives, which would facilitate the innovation of additive-free products. Experiments were performed at different temperatures and periods (22 degrees C for 45 and 60days, 30 degrees C for 45days) in 150 modified Sabouraud media characterized by high amount of sugars (glucose and fructose, 15% (w/v)), acetic acid (0.0-2.5% (v/v), 6 levels), pH (3.0-5.0, 5 levels) and a(w) (0.93-0.97, 5 levels). These time and temperature combinations were chosen as they are commonly applied for shelf-stable foods. The media were inoculated with ca. 4.5 log CFU/ml and yeast growth was monitored daily using optical density measurements. Every condition was examined in 20 replicates in order to yield accurate growth probabilities. Three separate ordinary logistic regression models were developed for different tested temperatures and incubation time. The total acetic acid concentration was considered as variable for all models. In general, when one intrinsic inhibitory factor became more stringent, the G/NG boundary shifted to less stressful conditions of the other two factors, resulting in enlarged no growth zones. Abrupt changes of growth probability often occurred around the transition zones (between growth and no growth regions), which indicates that minor variations in environmental conditions near the G/NG boundaries can cause a significant impact on the growth probability. When comparing growth after 45days between the

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

    PubMed

    Watson, Hannah; Bolton, Mark; Monaghan, Pat

    2015-03-01

    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. © 2015. Published by The Company of Biologists Ltd.

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

    PubMed Central

    Watson, Hannah; Bolton, Mark; Monaghan, Pat

    2015-01-01

    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

  13. Food Production, Population Growth, and Environmental Quality. Caltech Population Program Occasional Papers, Series 1, Number 7.

    ERIC Educational Resources Information Center

    Groth, Edward, III

    This paper, one in a series of occasional publications, discusses trends in food production and population growth, emphasizing how environmental quality will be affected. The series is intended to increase understanding of the interrelationships between population growth and socioeconomic and cultural patterns throughout the world, and to…

  14. Plant Growth and Morphogenesis under Different Gravity Conditions: Relevance to Plant Life in Space

    PubMed Central

    Hoson, Takayuki

    2014-01-01

    The growth and morphogenesis of plants are entirely dependent on the gravitational acceleration of earth. Under microgravity conditions in space, these processes are greatly modified. Recent space experiments, in combination with ground-based studies, have shown that elongation growth is stimulated and lateral expansion suppressed in various shoot organs and roots under microgravity conditions. Plant organs also show automorphogenesis in space, which consists of altered growth direction and spontaneous curvature in the dorsiventral (back and front) directions. Changes in cell wall properties are responsible for these modifications of growth and morphogenesis under microgravity conditions. Plants live in space with interesting new sizes and forms. PMID:25370193

  15. Carnitine palmitoyltransferase 1C promotes cell survival and tumor growth under conditions of metabolic stress

    PubMed Central

    Zaugg, Kathrin; Yao, Yi; Reilly, Patrick T.; Kannan, Karuppiah; Kiarash, Reza; Mason, Jacqueline; Huang, Ping; Sawyer, Suzanne K.; Fuerth, Benjamin; Faubert, Brandon; Kalliomäki, Tuula; Elia, Andrew; Luo, Xunyi; Nadeem, Vincent; Bungard, David; Yalavarthi, Sireesha; Growney, Joseph D.; Wakeham, Andrew; Moolani, Yasmin; Silvester, Jennifer; Ten, Annick You; Bakker, Walbert; Tsuchihara, Katsuya; Berger, Shelley L.; Hill, Richard P.; Jones, Russell G.; Tsao, Ming; Robinson, Murray O.; Thompson, Craig B.; Pan, Guohua; Mak, Tak W.

    2011-01-01

    Tumor cells gain a survival/growth advantage by adapting their metabolism to respond to environmental stress, a process known as metabolic transformation. The best-known aspect of metabolic transformation is the Warburg effect, whereby cancer cells up-regulate glycolysis under aerobic conditions. However, other mechanisms mediating metabolic transformation remain undefined. Here we report that carnitine palmitoyltransferase 1C (CPT1C), a brain-specific metabolic enzyme, may participate in metabolic transformation. CPT1C expression correlates inversely with mammalian target of rapamycin (mTOR) pathway activation, contributes to rapamycin resistance in murine primary tumors, and is frequently up-regulated in human lung tumors. Tumor cells constitutively expressing CPT1C show increased fatty acid (FA) oxidation, ATP production, and resistance to glucose deprivation or hypoxia. Conversely, cancer cells lacking CPT1C produce less ATP and are more sensitive to metabolic stress. CPT1C depletion via siRNA suppresses xenograft tumor growth and metformin responsiveness in vivo. CPT1C can be induced by hypoxia or glucose deprivation and is regulated by AMPKα. Cpt1c-deficient murine embryonic stem (ES) cells show sensitivity to hypoxia and glucose deprivation and altered FA homeostasis. Our results indicate that cells can use a novel mechanism involving CPT1C and FA metabolism to protect against metabolic stress. CPT1C may thus be a new therapeutic target for the treatment of hypoxic tumors. PMID:21576264

  16. Optimization of culture conditions to obtain maximal growth of penicillin-resistant Streptococcus pneumoniae

    PubMed Central

    Restrepo, Andrea V; Salazar, Beatriz E; Agudelo, María; Rodriguez, Carlos A; Zuluaga, Andres F; Vesga, Omar

    2005-01-01

    Background Streptococcus pneumoniae, particularly penicillin-resistant strains (PRSP), constitute one of the most important causes of serious infections worldwide. It is a fastidious microorganism with exquisite nutritional and environmental requirements to grow, a characteristic that prevents the development of useful animal models to study the biology of the microorganism. This study was designed to determine optimal conditions for culture and growth of PRSP. Results We developed a simple and reproducible method for culture of diverse strains of PRSP representing several invasive serotypes of clinical and epidemiological importance in Colombia. Application of this 3-step culture protocol consistently produced more than 9 log10 CFU/ml of viable cells in the middle part of the logarithmic phase of their growth curve. Conclusion A controlled inoculum size grown in 3 successive steps in supplemented agar and broth under 5% CO2 atmosphere, with pH adjustment and specific incubation times, allowed production of great numbers of PRSP without untimely activation of autolysis mechanisms. PMID:15932633

  17. Automated Diagnosis Of Conditions In A Plant-Growth Chamber

    NASA Technical Reports Server (NTRS)

    Clinger, Barry R.; Damiano, Alfred L.

    1995-01-01

    Biomass Production Chamber Operations Assistant software and hardware constitute expert system that diagnoses mechanical failures in controlled-environment hydroponic plant-growth chamber and recommends corrective actions to be taken by technicians. Subjects of continuing research directed toward development of highly automated closed life-support systems aboard spacecraft to process animal (including human) and plant wastes into food and oxygen. Uses Microsoft Windows interface to give technicians intuitive, efficient access to critical data. In diagnostic mode, system prompts technician for information. When expert system has enough information, it generates recovery plan.

  18. Therapeutic potential of growth factors in pulmonary emphysematous condition.

    PubMed

    Muyal, Jai Prakash; Muyal, Vandana; Kotnala, Sudhir; Kumar, Dhananjay; Bhardwaj, Harsh

    2013-04-01

    Pulmonary emphysema is a major manifestation of chronic obstructive pulmonary disease (COPD), which is characterized by progressive destruction of alveolar parenchyma with persistent inflammation of the small airways. Such destruction in the distal respiratory tract is irreversible and irreparable. All-trans-retinoic acid was suggested as a novel therapy for regeneration of lost alveoli in emphysema. However, profound discrepancies were evident between studies. At present, no effective therapeutic options are available that allow for the regeneration of lost alveoli in emphysematous human lungs. Recently, some reports on rodent's models have suggested the beneficial effects of various growth factors toward alveolar maintenance and repair processes.

  19. Automated Diagnosis Of Conditions In A Plant-Growth Chamber

    NASA Technical Reports Server (NTRS)

    Clinger, Barry R.; Damiano, Alfred L.

    1995-01-01

    Biomass Production Chamber Operations Assistant software and hardware constitute expert system that diagnoses mechanical failures in controlled-environment hydroponic plant-growth chamber and recommends corrective actions to be taken by technicians. Subjects of continuing research directed toward development of highly automated closed life-support systems aboard spacecraft to process animal (including human) and plant wastes into food and oxygen. Uses Microsoft Windows interface to give technicians intuitive, efficient access to critical data. In diagnostic mode, system prompts technician for information. When expert system has enough information, it generates recovery plan.

  20. Environmental influence on mussel (Mytilus edulis) growth - A quantile regression approach

    NASA Astrophysics Data System (ADS)

    Bergström, Per; Lindegarth, Mats

    2016-03-01

    The need for methods for sustainable management and use of coastal ecosystems has increased in the last century. A key aspect for obtaining ecologically and economically sustainable aquaculture in threatened coastal areas is the requirement of geographic information of growth and potential production capacity. Growth varies over time and space and depends on a complex pattern of interactions between the bivalve and a diverse range of environmental factors (e.g. temperature, salinity, food availability). Understanding these processes and modelling the environmental control of bivalve growth has been central in aquaculture. In contrast to the most conventional modelling techniques, quantile regression can handle cases where not all factors are measured and provide the possibility to estimate the effect at different levels of the response distribution and give therefore a more complete picture of the relationship between environmental factors and biological response. Observation of the relationships between environmental factors and growth of the bivalve Mytilus edulis revealed relationships that varied both among level of growth rate and within the range of environmental variables along the Swedish west coast. The strongest patterns were found for water oxygen concentration level which had a negative effect on growth for all oxygen levels and growth levels. However, these patterns coincided with differences in growth among periods and very little of the remaining variability within periods could be explained indicating that interactive processes masked the importance of the individual variables. By using quantile regression and local regression (LOESS) this study was able to provide valuable information on environmental factors influencing the growth of M. edulis and important insight for the development of ecosystem based management tools of aquaculture activities, its use in mitigation efforts and successful management of human use of coastal areas.

  1. Growth and development of Leghorn pullets subjected to abrupt changes in environmental temperature and dietary energy level.

    PubMed

    Leeson, S; Caston, L J

    1991-08-01

    Four trials were conducted to note the response of pullets to changes in environmental temperature and energy level at 56 days of age. In each trial, birds were fed diets providing either 2,500 or 3,000 kcal ME/kg throughout rearing, or with a single diet change from 2,500 to 3,000 and 3,000 to 2,500 kcal ME/kg occurring at 56 days. Each of the four diet scenarios was tested with six replicate caged groups each containing 10 pullets. In Trials 1 and 2 environmental temperature was maintained at 18 and 30 C, respectively, to 126 days. In Trials 3 and 4, temperature was changed at 56 days from 18 to 30 C and 30 to 18 C, respectively. Regardless of environmental temperature conditions, diet change per se had minimal effect on growth and development. Rather dietary energy level used from 56 to 126 days had the greatest effect on growth, with birds fed the highest energy content diet generally being heaviest. However, this effect was not significant (P greater than .05) in all trials, which is probably related to a lack of effect on energy intake under such conditions. Final body weight was more closely associated with energy intake than with protein intake and energy intake was maximized when high-energy diets were used after 56 days of age. Consumption of high-energy diets after 56 days, regardless of trial conditions, always resulted in increased carcass fat content at 126 days. It was concluded that abrupt and major changes in environmental temperature or dietary energy as used in these trials have little deleterious effect on pullet development. Conditions prevailing during later stages of growth have a far greater effect than changes per se in these parameters.

  2. Effect of economic growth and environmental quality on tourism in Southeast Asian Countries

    NASA Astrophysics Data System (ADS)

    Firmansyah

    2017-02-01

    The tourism is an important sector in generating income for a country, nevertheless, tourism is sensitive toward the changes in economy, as well as changes in environmental quality. By employing econometric models of error correction on annual data, this study examines the influence of environmental quality, domestic and global economic growth on foreign tourist arrivals in selected Southeast Asian countries, namely Indonesia, Malaysia, Thailand, Philippines, and Singapore. The findings of this study showed that all of countries long run model were proved statistically, indicated that world economic growth as well as environmental quality affect foreign tourism arrivals.

  3. Issues and options in addressing the environmental consequences of livestock sector's growth.

    PubMed

    Gerber, P J; Vellinga, T V; Steinfeld, H

    2010-02-01

    The growth of the livestock sector is being achieved at substantial environmental costs. Today, livestock are a major stressor of the global environmental, occupying a quarter of emerged land (including a third of arable land), contributing close to a fifth of the anthropogenic greenhouse gas emissions, using eight percent of all water resources and threatening a wide range of endangered species. At the same time, livestock are also a crucial engine of rural growth and a tool for improving food security. Policies are required to guide the sector in achieving sometimes conflicting development objectives. Potential pathways include encouraging resource use efficiency, correcting for environmental externalities and accelerating technological change.

  4. Environmental Factors Affecting Aquatic Plant Growth Potential in Marinuka Lake, Wisconsin

    DTIC Science & Technology

    2008-12-01

    ERDC/TN APCRP-EA-20 December 2008 Environmental Factors Affecting Aquatic Plant Growth Potential in Marinuka Lake, Wisconsin by William F. James...2008 Experimental evaluation of plant growth potential on Marinuka Lake sediments. Aquatic sediments were collected from Marinuka Lake and Eau Galle...Ten replicates for each sediment type (one plant per container) were incubated in a large outdoor facility consisting of plant growth tanks (4 ft

  5. Effects of simulated Mars conditions on the survival and growth of Escherichia coli and Serratia liquefaciens.

    PubMed

    Berry, Bonnie J; Jenkins, David G; Schuerger, Andrew C

    2010-04-01

    Escherichia coli and Serratia liquefaciens, two bacterial spacecraft contaminants known to replicate under low atmospheric pressures of 2.5 kPa, were tested for growth and survival under simulated Mars conditions. Environmental stresses of high salinity, low temperature, and low pressure were screened alone and in combination for effects on bacterial survival and replication, and then cells were tested in Mars analog soils under simulated Mars conditions. Survival and replication of E. coli and S. liquefaciens cells in liquid medium were evaluated for 7 days under low temperatures (5, 10, 20, or 30 degrees C) with increasing concentrations (0, 5, 10, or 20%) of three salts (MgCl(2), MgSO(4), NaCl) reported to be present on the surface of Mars. Moderate to high growth rates were observed for E. coli and S. liquefaciens at 30 or 20 degrees C and in solutions with 0 or 5% salts. In contrast, cell densities of both species generally did not increase above initial inoculum levels under the highest salt concentrations (10 and 20%) and the four temperatures tested, with the exception that moderately higher cell densities were observed for both species at 10% MgSO(4) maintained at 20 or 30 degrees C. Growth rates of E. coli and S. liquefaciens in low salt concentrations were robust under all pressures (2.5, 10, or 101.3 kPa), exhibiting a general increase of up to 2.5 orders of magnitude above the initial inoculum levels of the assays. Vegetative E. coli cells were maintained in a Mars analog soil for 7 days under simulated Mars conditions that included temperatures between 20 and -50 degrees C for a day/night diurnal period, UVC irradiation (200 to 280 nm) at 3.6 W m(-2) for daytime operations (8 h), pressures held at a constant 0.71 kPa, and a gas composition that included the top five gases found in the martian atmosphere. Cell densities of E. coli failed to increase under simulated Mars conditions, and survival was reduced 1 to 2 orders of magnitude by the interactive

  6. Effects of Simulated Mars Conditions on the Survival and Growth of Escherichia coli and Serratia liquefaciens▿

    PubMed Central

    Berry, Bonnie J.; Jenkins, David G.; Schuerger, Andrew C.

    2010-01-01

    Escherichia coli and Serratia liquefaciens, two bacterial spacecraft contaminants known to replicate under low atmospheric pressures of 2.5 kPa, were tested for growth and survival under simulated Mars conditions. Environmental stresses of high salinity, low temperature, and low pressure were screened alone and in combination for effects on bacterial survival and replication, and then cells were tested in Mars analog soils under simulated Mars conditions. Survival and replication of E. coli and S. liquefaciens cells in liquid medium were evaluated for 7 days under low temperatures (5, 10, 20, or 30°C) with increasing concentrations (0, 5, 10, or 20%) of three salts (MgCl2, MgSO4, NaCl) reported to be present on the surface of Mars. Moderate to high growth rates were observed for E. coli and S. liquefaciens at 30 or 20°C and in solutions with 0 or 5% salts. In contrast, cell densities of both species generally did not increase above initial inoculum levels under the highest salt concentrations (10 and 20%) and the four temperatures tested, with the exception that moderately higher cell densities were observed for both species at 10% MgSO4 maintained at 20 or 30°C. Growth rates of E. coli and S. liquefaciens in low salt concentrations were robust under all pressures (2.5, 10, or 101.3 kPa), exhibiting a general increase of up to 2.5 orders of magnitude above the initial inoculum levels of the assays. Vegetative E. coli cells were maintained in a Mars analog soil for 7 days under simulated Mars conditions that included temperatures between 20 and −50°C for a day/night diurnal period, UVC irradiation (200 to 280 nm) at 3.6 W m−2 for daytime operations (8 h), pressures held at a constant 0.71 kPa, and a gas composition that included the top five gases found in the martian atmosphere. Cell densities of E. coli failed to increase under simulated Mars conditions, and survival was reduced 1 to 2 orders of magnitude by the interactive effects of desiccation, UV

  7. Properties of kenaf from various cultivars, growth and pulping conditions

    Treesearch

    James S. Han; Ernest S. Miyashita; Sara J. Spielvogel

    1999-01-01

    The physical properties of kenaf offer potential as an alternative raw material for the manufacture of paper. Investigations to date have not determined whether core and fiber should be pulped together or separately. Kenaf bast and core fibers of different cultivars were pulped under various kraft pulping conditions and physical properties: density, Canadian Standard...

  8. Toxicity of pentachlorophenol to aquatic organisms under naturally varying and controlled environmental conditions

    SciTech Connect

    Hedtke, S.F.; West, C.W.; Allen, K.N.; Norberg-King, T.J.; Mount, D.I.

    1986-06-01

    The toxicity of pentachlorophenol (PCP) was determined in the laboratory for 11 aquatic species. Tests were conducted seasonally in ambient Mississippi River water and under controlled conditions in Lake Superior water. Fifty-one acute toxicity tests were conducted, with LC50 values ranging from 85 micrograms/L for the white sucker Catastomus commersoni during the summer to greater than 7770 micrograms/L for the isopod Asellus racovitzai during the winter. The effect of PCP on growth and/or reproduction was determined for seven species. The most sensitive chronically exposed organisms were the cladoceran Ceriodaphnia reticulata and the snail Physa gyrina. The greatest variation in toxicity was due to species sensitivity. Within a given, season there was as much as a 40-fold difference in LC50 values between species. For any one species, the maximum variation in LC50 between seasons was approximately 14-fold. There were also substantial differences in acute-chronic relationships, with acute/chronic ratios ranging from greater than 37 for C. reticulata to 1 for Simocephalus vetulus. It is suggested that the composition of the aquatic community should be the most important consideration in estimating the potential environmental effects of PCP.

  9. Effects of social housing condition and behavior on growth of the Shionogi mouse mammary carcinoma.

    PubMed

    Grimm, M S; Emerman, J T; Weinberg, J

    1996-01-01

    We have demonstrated marked effects of social housing condition on the growth rate of the androgen-responsive Shionogi mouse mammary carcinoma. The present study investigated the possible role of psychosocial variables in modulating the differential tumor growth rates observed. Male DD/S mice were reared individually housed (I) or in groups (G) of three or five siblings or nonsiblings. Following tumor cell injection, mice either remained in their rearing conditions (II, GG) or were rehoused (IG, GI). Effects of group size, sibling relationship, dominance status, change vs. no change in housing condition, and direction of change (individual to group or group to individual) were examined. Home cage behaviors were monitored both prior to and following tumor cell injection and rehousing. Overall, mice in the GI conditions showed faster tumor growth rates than mice in the IG conditions. Mice in the II and GG conditions showed intermediate tumor growth rates. Differences in group size and sibling relationship prior to and following tumor cell injection and rehousing had no significant influence on tumor growth rates. However, both change in housing condition and direction of change following tumor cell injection/rehousing were significant variables in modulating differential tumor growth rates. Dominance status differentially influenced tumor growth depending on whether mice experienced a change in housing; in the IG conditions, dominant mice showed faster tumor growth whereas in the GG conditions, dominant mice showed slower tumor growth than subordinate mice. Increased fighting among mice in IG compared to mice in GG conditions may play a role in modulating differential tumor growth rates.

  10. Salmon on the Edge: Growth and Condition of Juvenile Chum and Pink Salmon in the Northeastern Bering Sea

    NASA Astrophysics Data System (ADS)

    McPhee, M. V.

    2016-02-01

    As the Arctic and Subarctic regions warm, Pacific salmon (Oncorhynchus spp.) are expected to expand their range northward during ice-free periods in the Bering and Chukchi seas. The oscillating control hypothesis, which describes energetic differences of primary consumers between ice-associated and pelagic production phases, provides a framework for understanding how juvenile salmon might respond to changing conditions at the northern edge of their marine range. Additionally, relationships between growth/condition and temperature, salinity and bottom depth will help identify marine habitats supporting growth at the Arctic-Subarctic interface. In this study, we used survey data from NOAA and Arctic Ecosystem Integrated Survey project to 1) compare growth and condition of juvenile pink (O. gorbuscha) and chum (O. keta) salmon in the NE Bering Sea between warm and cool spring phases, and 2) describe relationships between summer environmental conditions and juvenile salmon growth and condition from 2006 - 2010. Chum and pink salmon were shorter, and chum salmon exhibited greater energy density, in years with cool springs; however, no other aspects of size and condition differed significantly between phases. Over all years, longer and more energy dense individuals of both species were caught at stations with greater bottom depths and in cooler sea-surface temperatures. We found little evidence that chlorophyll-a explained much of the variation in size or condition. We used insulin-like growth factor-1 (IGF-1) concentration as an indicator of relative growth rate for fishes sampled in 2009-2012 and that found juvenile salmon exhibited higher IGF-1 concentrations in 2010-2012 than in 2009. IGF-1 concentrations tended to increase with SST in chum salmon and with bottom depth (a proxy for distance from shore) in pink salmon, but more years of data are needed to adequately describe the relationship of IGF with environmental conditions. This study, although descriptive in

  11. Hydrothermal growth of ZnO nanoparticles under different conditions

    NASA Astrophysics Data System (ADS)

    Yilmaz, Mehmet; Bozkurt Cirak, Burcu; Cirak, Cagri; Aydogan, Sakir

    2016-02-01

    In this study, a simple low-temperature hydrothermal method was used to synthesize ZnO nanoparticles. The structural, morphological and optical characterizations of the nanoparticles were evaluated with regard to the zinc content. To achieve this, the molar ratios of the precursors were changed from 0.05 to 0.1 M. The structural and morphological analyses showed that all samples had a polycrystalline hexangular wurtzite crystal structure and the shape of the ZnO nanoparticles changed with increasing zinc content. A possible growth mechanism of the ZnO nanoparticles is explained in terms of the zinc content. Optical measurement revealed that the shape of the nanoparticles affects the position of the band-edge emission as well as the shape of the luminescence spectrum.

  12. Life histories have a history: effects of past and present conditions on adult somatic growth rates in wild Trinidadian guppies.

    PubMed

    Auer, Sonya K; Lopez-Sepulcre, Andrés; Heatherly, Thomas; Kohler, Tyler J; Bassar, Ronald D; Thomas, Steven A; Reznick, David N

    2012-07-01

    1. Environmental conditions in the present, more recent past and during the juvenile stage can have significant effects on adult performance and population dynamics, but their relative importance and potential interactions remain unexplored. 2. We examined the influence of food availability at the time of sampling, 2 months prior and during the juvenile stage on adult somatic growth rates in wild Trinidadian guppies (Poecilia reticulata). 3. We found that food availability during both the early and later parts of an individual's ontogeny had important consequences for adult growth strategies, but the direction of these effects differed among life stages and their magnitude, in some cases, depended on food levels experienced during other life stages. Current food levels and those 2 months prior to growth measurements had positive effects on adult growth rate; though, food levels 2 months prior had a greater effect on growth than current food levels. In contrast, the effects of food availability during the juvenile stage were higher in magnitude but opposite in direction to current food levels and those 2 months prior to growth rate measurements. Individuals recruiting under low food levels grew faster as adults than individuals recruiting during periods of high food availability. There was also a positive interaction between food levels experienced during the juvenile stage and 2 months prior such that the effects of juvenile food level diminished as the food level experienced 2 months prior increased. 4. These results suggest that the similar conditions occurring at different life stages can have different effects on short- and long-term growth strategies of individuals within a population. They also demonstrate that, while juvenile conditions can have lasting effects on adult performance, the strength of that effect can be dampened by environmental conditions experienced as an adult. 5. A simultaneous consideration of past events in both the

  13. Performing Comparative Peptidomics Analyses of Salmonella from Different Growth Conditions

    SciTech Connect

    Adkins, Joshua N.; Mottaz, Heather; Metz, Thomas O.; Ansong, Charles K.; Manes, Nathan P.; Smith, Richard D.; Heffron, Fred

    2010-01-08

    Host–pathogen interactions are complex competitions during which both the host and the pathogen adapt rapidly to each other in order for one or the other to survive. Salmonella enterica serovar Typhimurium is a pathogen with a broad host range that causes a typhoid fever-like disease in mice and severe food poisoning in humans. The murine typhoid fever is a systemic infection in which S.typhimurium evades part of the immune system by replicating inside macrophages and other cells. The transition from a foodborne contaminant to an intracellular pathogen must occur rapidly in multiple,ordered steps in order for S. typhimurium to thrive within its host environment. Using S. typhimurium isolated from rich culture conditions and from conditions that mimic the hostile intracellular environment of the host cell, a native low molecular weight protein fraction, or peptidome, was enriched from cell lysates by precipitation with organic solvents. The enriched peptidome was analyzed by both LC–MS/MS and LC–MS-based methods, although several other methods are possible. Pre-fractionation of peptides allowed identification of small proteins and protein degradation products that would normally be overlooked. Comparison of peptides present in lysates prepared from Salmonella grown under different conditions provided a unique insight into cellular degradation processes as well as identification of novel peptides encoded in the genome but not annotated. The overall approach is detailed here as applied to Salmonella and is adaptable to a broad range of biological systems.

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

    PubMed

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

    2013-09-01

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

  15. Effects of Solar Loading and Other Environmental Conditions on Thermographic Imaging of Subsurface Defects in Concrete

    NASA Astrophysics Data System (ADS)

    Washer, G. A.; Fenwick, R. G.; Bolleni, N.; Harper, J.

    2009-03-01

    The detection of subsurface defects in concrete using infrared cameras relies on thermal variations in the ambient environment to provide heat flow. Solar loading can provide significant thermal energy that enables the imaging of subsurface defects. This paper presents results of a study to determine the optimum environmental conditions for conducting thermal inspection of concrete bridges. This study has included continuous monitoring of a large concrete specimen under ambient environmental condition in central Missouri. The thermal contrast of subsurface targets in the specimen has been analyzed to determine the optimum conditions and time for detection of subsurface features as a function of depth. Environmental conditions that result in the largest contrast in surface temperature are discussed.

  16. The Influence of Individual Variability on Zooplankton Population Dynamics under Different Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Bi, R.; Liu, H.

    2016-02-01

    Understanding how biological components respond to environmental changes could be insightful to predict ecosystem trajectories under different climate scenarios. Zooplankton are key components of marine ecosystems and changes in their dynamics could have major impact on ecosystem structure. We developed an individual-based model of a common coastal calanoid copepod Acartia tonsa to examine how environmental factors affect zooplankton population dynamics and explore the role of individual variability in sustaining population under various environmental conditions consisting of temperature, food concentration and salinity. Total abundance, egg production and proportion of survival were used to measure population success. Results suggested population benefits from high level of individual variability under extreme environmental conditions including unfavorable temperature, salinity, as well as low food concentration, and selection on fast-growers becomes stronger with increasing individual variability and increasing environmental stress. Multiple regression analysis showed that temperature, food concentration, salinity and individual variability have significant effects on survival of A. tonsa population. These results suggest that environmental factors have great influence on zooplankton population, and individual variability has important implications for population survivability under unfavorable conditions. Given that marine ecosystems are at risk from drastic environmental changes, understanding how individual variability sustains populations could increase our capability to predict population dynamics in a changing environment.

  17. FIS-dependent trans activation of stable RNA operons of Escherichia coli under various growth conditions.

    PubMed

    Nilsson, L; Verbeek, H; Vijgenboom, E; van Drunen, C; Vanet, A; Bosch, L

    1992-02-01

    In Escherichia coli transcription of the tRNA operon thrU (tufB) and the rRNA operon rrnB is trans-activated by the protein FIS. This protein, which stimulates the inversion of various viral DNA segments, binds specifically to a cis-acting sequence (designated UAS) upstream of the promoter of thrU (tufB) and the P1 promoter of the rrnB operon. There are indications that this type of regulation is representative for the regulation of more stable RNA operons. In the present investigation we have studied UAS-dependent transcription activation of the thrU (tufB) operon in the presence and absence of FIS during a normal bacterial growth cycle and after a nutritional shift-up. In early log phase the expression of the operon rises steeply in wild-type cells, whereafter it declines. Concomitantly, a peak of the cellular FIS concentration is observed. Cells in the stationary phase are depleted of FIS. The rather abrupt increase of transcription activation depends on the nutritional quality of the medium. It is not seen in minimal medium. After a shift from minimal to rich medium, a peak of transcription activation and of FIS concentration is measured. This peak gets higher as the medium gets more strongly enriched. We conclude that a correlation between changes of the UAS-dependent activation of the thrU (tufB) operon and changes of the cellular FIS concentration under a variety of experimental conditions exists. This correlation strongly suggests that the production of FIS responds to environmental signals, thereby trans-activating the operon. Cells unable to produce FIS (fis cells) also show an increase of operon transcription in the early log phase and after a nutritional shift-up, albeit less pronounced than that wild-type cells. Presumably it is controlled by the ribosome feedback regulatory system. cis activation of the operon by the upstream activator sequence is apparent in the absence of FIS. This activation is constant throughout the entire growth cycle and is

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

    PubMed

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

    2013-05-07

    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.

  19. Microbial diversity during cellulose decomposition in different forest stands: I. microbial communities and environmental conditions.

    PubMed

    Kubartová, Ariana; Moukoumi, Judicaël; Béguiristain, Thierry; Ranger, Jacques; Berthelin, Jacques

    2007-10-01

    We studied the effect of forest tree species on a community of decomposers that colonize cellulose strips. Both fungal and bacterial communities were targeted in a native forest dominated by beech and oak and 30-year-old beech and spruce plantations, growing in similar ecological conditions in the Breuil-Chenue experimental forest site in Morvan (France). Microbial ingrowths from the 3rd to 10th month of strip decomposition (May to December 2004) were studied. Community composition was assessed using temperature gradient gel electrophoresis with universal fungal (ITS1F, ITS2) and bacterial (1401r, 968f) primers. Soil temperature and moisture as well as fungal biomass were also measured to give additional information on decomposition processes. Changing the dominant tree species had no significant influence in the number of decomposer species. However, decomposer community composition was clearly different. If compared to the native forest, where community composition highly differed, young monocultures displayed similar species structure for fungi and bacteria. Both species numbers and community composition evolved during the decay process. Time effect was found to be more important than tree species. Nevertheless, the actual environmental conditions and seasonal effect seemed to be even more determining factors for the development of microbial communities. The course and correlations of the explored variables often differed between tree species, although certain general trends were identified. Fungal biomass was high in summer, despite that species richness (SR) decreased and conversely, that high SR did not necessarily mean high biomass values. It can be concluded that the growth and development of the microbiological communities that colonized a model material in situ depended on the combination of physical and biological factors acting collectively and interdependently at the forest soil microsite.

  20. Growth of samarskite crystal under microgravity conditions (M-20)

    NASA Technical Reports Server (NTRS)

    Takekawa, S.

    1993-01-01

    The purpose of the experiment was to grow single crystals of samarskite under microgravity conditions by the traveling solvent float zone (TSFZ) method, and to study the phase relations in the samarskite-related systems involving liquid phases by the slow cooling float zone (SCFZ) method. Samarskite is one of the minerals in a metamict state and is composed of Ca, Fe, Y, U, Th, Nb, Ta, O, etc. Alpha-particles radiating from uranium and/or thorium in the samarskite itself has destroyed its original structure without damaging its chemical composition and its external form. Consequently its structure was converted into a vitreous structure.

  1. Evaluation of condition indices for estimation of growth of largemouth bass and white crappie

    USGS Publications Warehouse

    Gutreuter, Steve; Childress, W. Michael

    1990-01-01

    We evaluated the ability of three condition indices-condition factor (K), relative condition (Kn), and relative weight (Wr)-to estimate annual growth rates of largemouth bass Micropterus salmoides and white crappies Pomoxis annularis collected during standardized autumn electrofishing and trap-net surveys of Texas reservoirs. Multiple-regression models for estimation of length increments from initial length (at the start of the growing season) and condition indices had R2 values of 0.63-0.76 for largemouth bass and 0.46-0.83 for white crappie. However, these models are not useful for indirect estimation ofgrowth rates because growth must be known (initial length equals length at capture minus estimated annual growth). Models based on length at capture and condition indices had R2 values of 0.22-0.68 for largemouth bass and less than 0.45 for white crappie. The low precision of models based on length at capture indicates that condition provides a weak basis for indirect estimation of growth rates from Texas reservoirs sampled during autumn and, therefore, is unreliable for detection of size-related growth phenomena such as "stockpiling" (size specific, density-dependent growth depression). Direct estimates of growth rates based on back-calculations or tagging data seem necessary for reliable detection of size-related growth patterns for largemouth bass and white crappies from Texas reservoirs.

  2. Impact of the environmental conditions and substrate pre-treatment on whey protein hydrolysis: A review.

    PubMed

    Cheison, Seronei Chelulei; Kulozik, Ulrich

    2017-01-22

    Proteins in solution are subject to myriad forces stemming from interactions with each other as well as with the solvent media. The role of the environmental conditions, namely pH, temperature, ionic strength remains under-estimated yet it impacts protein conformations and consequently its interaction with, and susceptibility to, the enzyme. Enzymes, being proteins are also amenable to the environmental conditions because they are either activated or denatured depending on the choice of the conditions. Furthermore, enzyme specificity is restricted to a narrow regime of optimal conditions while opportunities outside the optimum conditions remain untapped. In addition, the composition of protein substrate (whether mixed or single purified) have been underestimated in previous studies. In addition, protein pre-treatment methods like heat denaturation prior to hydrolysis is a complex phenomenon whose progression is influenced by the environmental conditions including the presence or absence of sugars like lactose, ionic strength, purity of the protein, and the molecular structure of the mixed proteins particularly presence of free thiol groups. In this review, we revisit protein hydrolysis with a focus on the impact of the hydrolysis environment and show that preference of peptide bonds and/or one protein over another during hydrolysis is driven by the environmental conditions. Likewise, heat-denaturing is a process which is dependent on not only the environment but the presence or absence of other proteins.

  3. Estimating geographic variation on allometric growth and body condition of Blue Suckers with quantile regression

    USGS Publications Warehouse

    Cade, B.S.; Terrell, J.W.; Neely, B.C.

    2011-01-01

    Increasing our understanding of how environmental factors affect fish body condition and improving its utility as a metric of aquatic system health require reliable estimates of spatial variation in condition (weight at length). We used three statistical approaches that varied in how they accounted for heterogeneity in allometric growth to estimate differences in body condition of blue suckers Cycleptus elongatus across 19 large-river locations in the central USA. Quantile regression of an expanded allometric growth model provided the most comprehensive estimates, including variation in exponents within and among locations (range = 2.88–4.24). Blue suckers from more-southerly locations had the largest exponents. Mixed-effects mean regression of a similar expanded allometric growth model allowed exponents to vary among locations (range = 3.03–3.60). Mean relative weights compared across selected intervals of total length (TL = 510–594 and 594–692 mm) in a multiplicative model involved the implicit assumption that allometric exponents within and among locations were similar to the exponent (3.46) for the standard weight equation. Proportionate differences in the quantiles of weight at length for adult blue suckers (TL = 510, 594, 644, and 692 mm) compared with their average across locations ranged from 1.08 to 1.30 for southern locations (Texas, Mississippi) and from 0.84 to 1.00 for northern locations (Montana, North Dakota); proportionate differences for mean weight ranged from 1.13 to 1.17 and from 0.87 to 0.95, respectively, and those for mean relative weight ranged from 1.10 to 1.18 and from 0.86 to 0.98, respectively. Weights for fish at longer lengths varied by 600–700 g within a location and by as much as 2,000 g among southern and northern locations. Estimates for the Wabash River, Indiana (0.96–1.07 times the average; greatest increases for lower weights at shorter TLs), and for the Missouri River from Blair, Nebraska, to Sioux City, Iowa (0.90

  4. Growth conditions influence melanization of Brazilian clinical Sporothrix schenckii isolates

    PubMed Central

    Almeida-Paes, Rodrigo; Frases, Susana; Monteiro, Paulo Cezar Fialho; Gutierrez-Galhardo, Maria Clara; Zancopé-Oliveira, Rosely Maria; Nosanchuk, Joshua D.

    2009-01-01

    Sporothrix schenckii is known to produce DHN melanin on both conidial and yeast cells, however little information is available regarding the factors inducing fungal melanization. We evaluated whether culture conditions influenced melanization of 25 Brazilian S. schenckii strains and one control strain (ATCC 10212). Tested conditions included different media, pH, temperature, incubation time, glucose concentrations, and presence or absence of tricyclazole or L-DOPA. Melanization was reduced on Sabouraud compared to defined chemical medium. The majority of strains produced small amounts of melanin at 37°C and none melanized at basic pH. Increased glucose concentrations did not inhibit melanization, rather increasing glucose enhanced pigment production in 27% of strains. Melanin synthesis was also enhanced by the addition of L-DOPA and its addition to medium with tricyclazole, an inhibitor of melanin synthesis, resulted in fungal melanization, including hyphal melanin production. Our results suggest that different S. schenckii strains have distinct control of melanization and that this fungus can use phenolic compounds to enhance melanization in vitro. PMID:19328867

  5. Systemic regulation of soybean nodulation by acidic growth conditions.

    PubMed

    Lin, Meng-Han; Gresshoff, Peter M; Ferguson, Brett J

    2012-12-01

    Mechanisms inhibiting legume nodulation by low soil pH, although highly prevalent and economically significant, are poorly understood. We addressed this in soybean (Glycine max) using a combination of physiological and genetic approaches. Split-root and grafting studies using an autoregulation-of-nodulation-deficient mutant line, altered in the autoregulation-of-nodulation receptor kinase GmNARK, determined that a systemic, shoot-controlled, and GmNARK-dependent mechanism was critical for facilitating the inhibitory effect. Acid inhibition was independent of aluminum ion concentration and occurred early in nodule development, between 12 and 96 h post inoculation with Bradyrhizobium japonicum. Biological effects were confirmed by measuring transcript numbers of known early nodulation genes. Transcripts decreased on both sides of split-root systems, where only one side was subjected to low-pH conditions. Our findings enhance the present understanding of the innate mechanisms regulating legume nodulation control under acidic conditions, which could benefit future attempts in agriculture to improve nodule development and biological nitrogen fixation in acid-stressed soils.

  6. Ion uptake of marigold under saline growth conditions.

    PubMed

    Koksal, Nezihe; Alkan-Torun, Ayfer; Kulahlioglu, Ilknur; Ertargin, Ebru; Karalar, Eylul

    2016-01-01

    Salinity is one of most significant environmental stresses. Marigold is moderately tolerant to salinity stress. Therefore, in this study, the fresh weights of roots and shoots, rootFW/shootFW ratio, moisture content of shoots, micronutrient and macronutrient concentrations and ratios of K(+)/Na(+) and Ca(2+)/Na(+) in the roots and shoots of marigold were determined under salinity stress. Five salinity treatments (0, 50, 100, 150, and 200 mM NaCl) were maintained. In the current study, salinity affected the biomass of marigold. An increase of more than 100 mM in salt concentrations significantly reduced the shoot fresh weight. Increasing salinity stress increased the ratios of rootFW/shootFW, which were more significant under high salt levels (150 and 200 mM NaCl). Wet basis moisture contents of the shoots were reduced when salinity stress increased above 100 mM. In this study, salinity stress affected micronutrient and macronutrient uptake. Increases in the salt concentration and decreases in the concentration of Cu(2+) and Zn(2+) in the roots and Mn(2+) and Fe(2+) in the shoots were significant. Based on an increase in salinity stress, while the Ca(2+), Mg(2+), and Na(+) concentrations increased, the K(+) concentration decreased in the roots and shoots. Moreover, the K(+)/Na(+) and Ca(2+)/Na(+) ratios of the roots and shoots were significantly lower than those of the control in all of the salinity treatments. As a result, under increasing salinity stress, the Ca(2+), Mg(2+), K(+), and Na(+) uptakes in marigold were significant, revealing the effects of stress.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    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.

  8. Actual measurement, hygrothermal response experiment and growth prediction analysis of microbial contamination of central air conditioning system in Dalian, China

    PubMed Central

    Lv, Yang; Hu, Guangyao; Wang, Chunyang; Yuan, Wenjie; Wei, Shanshan; Gao, Jiaoqi; Wang, Boyuan; Song, Fangchao

    2017-01-01

    The microbial contamination of central air conditioning system is one of the important factors that affect the indoor air quality. Actual measurement and analysis were carried out on microbial contamination in central air conditioning system at a venue in Dalian, China. Illumina miseq method was used and three fungal samples of two units were analysed by high throughput sequencing. Results showed that the predominant fungus in air conditioning unit A and B were Candida spp. and Cladosporium spp., and two fungus were further used in the hygrothermal response experiment. Based on the data of Cladosporium in hygrothermal response experiment, this paper used the logistic equation and the Gompertz equation to fit the growth predictive model of Cladosporium genera in different temperature and relative humidity conditions, and the square root model was fitted based on the two environmental factors. In addition, the models were carried on the analysis to verify the accuracy and feasibility of the established model equation. PMID:28367963

  9. Transcriptomic, proteomic and metabolomic analysis of maize responses to UV-B: comparison of greenhouse and field growth conditions.

    PubMed

    Casati, Paula; Campi, Mabel; Morrow, Darren J; Fernandes, John; Walbot, Virginia

    2011-08-01

    UV-B radiation from normal solar fluence elicits physiological and developmental changes in plants under fluctuating environmental conditions. Most UV photobiology studies in plants utilize controlled greenhouse and growth chamber environments in which few conditions vary except the brief presence of UV-B radiation. Our purpose was to compare responses to UV-B in irradiated and shielded maize organs in field (natural solar plus 2x solar supplementation for defined periods) and greenhouse (2x solar supplementation only) conditions during a 4 hour exposure. Three parameters were assessed--transcripts, proteins, and metabolites--to determine the degree of overlap in maize responses in field and greenhouse conditions. We assessed irradiated leaves, and both shielded leaves and immature ears. After comparing transcriptome, proteome and metabolome profiles, we find there are more differences than similarities between field and greenhouse responses.

  10. Actual measurement, hygrothermal response experiment and growth prediction analysis of microbial contamination of central air conditioning system in Dalian, China.

    PubMed

    Lv, Yang; Hu, Guangyao; Wang, Chunyang; Yuan, Wenjie; Wei, Shanshan; Gao, Jiaoqi; Wang, Boyuan; Song, Fangchao

    2017-04-03

    The microbial contamination of central air conditioning system is one of the important factors that affect the indoor air quality. Actual measurement and analysis were carried out on microbial contamination in central air conditioning system at a venue in Dalian, China. Illumina miseq method was used and three fungal samples of two units were analysed by high throughput sequencing. Results showed that the predominant fungus in air conditioning unit A and B were Candida spp. and Cladosporium spp., and two fungus were further used in the hygrothermal response experiment. Based on the data of Cladosporium in hygrothermal response experiment, this paper used the logistic equation and the Gompertz equation to fit the growth predictive model of Cladosporium genera in different temperature and relative humidity conditions, and the square root model was fitted based on the two environmental factors. In addition, the models were carried on the analysis to verify the accuracy and feasibility of the established model equation.

  11. Effects of several environmental factors on sweetpotato growth

    NASA Technical Reports Server (NTRS)

    Loretan, P. A.; Bonsi, C. K.; Mortley, D. G.; Wheeler, R. M.; Mackowiak, C. L.; Hill, W. A.; Morris, C. E.; Trotman, A. A.; David, P. P.

    1994-01-01

    Effects of relative humidity, light intensity and photoperiod on growth of 'Ga Jet' and TI-155' sweetpotato cultivars, using the nutrient film technique (NFT), have been reported. In this study, the effect of ambient temperature regimes (constant 28 C and diurnal 28:222 C day:night) and different CO2 levels (ambient, 400, 1 000 and 10 000 microL/L-400, 1 000 and 10 000 ppm) on growth of one or both of these cultivars in NFT are reported. For a 24-h photoperiod, no storage roots were prodcued for either cultivar in NFT when sweetpotato plants were grown at a constant temperature of 28 C. For the same photoperiod, when a 28:22 C diurnal temperature variation was used, there were still no storage roots for 'TI-155' but the cv. 'Ga Jet' produced 537 g/plant of storage roots. For both a 12-h and 24-h photoperiod. 'Ga Jet' storage root fresh and dry weight tended to be higher with a 28:22 C diurnal temperature variation than with a constant 28 C temperature regime. Preliminary results with both 'Ga Jet' and 'TI-155' cultivars indicate a distinctive diurnal stomatal response for sweetpotato grown in NFT under an ambient CO2 level. The stomatal conductance values observed for 'Ga Jet' at elevated CO2 levels indicated that the difference between the light- and dark-period conductance rates persisted at 400, 1 000, and 10 000 microL/L.

  12. Corrosion pitting and environmentally assisted small crack growth.

    PubMed

    Turnbull, Alan

    2014-09-08

    In many applications, corrosion pits act as precursors to cracking, but qualitative and quantitative prediction of damage evolution has been hampered by lack of insights into the process by which a crack develops from a pit. An overview is given of recent breakthroughs in characterization and understanding of the pit-to-crack transition using advanced three-dimensional imaging techniques such as X-ray computed tomography and focused ion beam machining with scanning electron microscopy. These techniques provided novel insights with respect to the location of crack development from a pit, supported by finite-element analysis. This inspired a new concept for the role of pitting in stress corrosion cracking based on the growing pit inducing local dynamic plastic strain, a critical factor in the development of stress corrosion cracks. Challenges in quantifying the subsequent growth rate of the emerging small cracks are then outlined with the potential drop technique being the most viable. A comparison is made with the growth rate for short cracks (through-thickness crack in fracture mechanics specimen) and long cracks and an electrochemical crack size effect invoked to rationalize the data.

  13. Effects of several environmental factors on sweetpotato growth

    NASA Technical Reports Server (NTRS)

    Loretan, P. A.; Bonsi, C. K.; Mortley, D. G.; Wheeler, R. M.; Mackowiak, C. L.; Hill, W. A.; Morris, C. E.; Trotman, A. A.; David, P. P.

    1994-01-01

    Effects of relative humidity, light intensity and photoperiod on growth of 'Ga Jet' and TI-155' sweetpotato cultivars, using the nutrient film technique (NFT), have been reported. In this study, the effect of ambient temperature regimes (constant 28 C and diurnal 28:222 C day:night) and different CO2 levels (ambient, 400, 1 000 and 10 000 microL/L-400, 1 000 and 10 000 ppm) on growth of one or both of these cultivars in NFT are reported. For a 24-h photoperiod, no storage roots were prodcued for either cultivar in NFT when sweetpotato plants were grown at a constant temperature of 28 C. For the same photoperiod, when a 28:22 C diurnal temperature variation was used, there were still no storage roots for 'TI-155' but the cv. 'Ga Jet' produced 537 g/plant of storage roots. For both a 12-h and 24-h photoperiod. 'Ga Jet' storage root fresh and dry weight tended to be higher with a 28:22 C diurnal temperature variation than with a constant 28 C temperature regime. Preliminary results with both 'Ga Jet' and 'TI-155' cultivars indicate a distinctive diurnal stomatal response for sweetpotato grown in NFT under an ambient CO2 level. The stomatal conductance values observed for 'Ga Jet' at elevated CO2 levels indicated that the difference between the light- and dark-period conductance rates persisted at 400, 1 000, and 10 000 microL/L.

  14. Corrosion pitting and environmentally assisted small crack growth

    PubMed Central

    Turnbull, Alan

    2014-01-01

    In many applications, corrosion pits act as precursors to cracking, but qualitative and quantitative prediction of damage evolution has been hampered by lack of insights into the process by which a crack develops from a pit. An overview is given of recent breakthroughs in characterization and understanding of the pit-to-crack transition using advanced three-dimensional imaging techniques such as X-ray computed tomography and focused ion beam machining with scanning electron microscopy. These techniques provided novel insights with respect to the location of crack development from a pit, supported by finite-element analysis. This inspired a new concept for the role of pitting in stress corrosion cracking based on the growing pit inducing local dynamic plastic strain, a critical factor in the development of stress corrosion cracks. Challenges in quantifying the subsequent growth rate of the emerging small cracks are then outlined with the potential drop technique being the most viable. A comparison is made with the growth rate for short cracks (through-thickness crack in fracture mechanics specimen) and long cracks and an electrochemical crack size effect invoked to rationalize the data. PMID:25197249

  15. Effects of several environmental factors on sweetpotato growth.

    PubMed

    Loretan, P A; Bonsi, C K; Mortley, D G; Wheeler, R M; Mackowiak, C L; Hill, W A; Morris, C E; Trotman, A A; David, P P

    1994-11-01

    Effects of relative humidity, light intensity and photoperiod on growth of 'Ga Jet' and 'TI-155' sweetpotato cultivars, using the nutrient film technique (NFT), have been reported. In this study, the effect of ambient temperature regimes (constant 28 degrees C and diurnal 28:22 degrees C day:night) and different CO2 levels (ambient, 400, 1000 and 10000 microliters/L--400, 1000 and 10000 ppm) on growth of one or both of these cultivars in NFT are reported. For a 24-h p