The influence of local effects on thermal sensation under non-uniform environmental conditions--gender differences in thermophysiology, thermal comfort and productivity during convective and radiant cooling.

PubMed

Schellen, L; Loomans, M G L C; de Wit, M H; Olesen, B W; van Marken Lichtenbelt, W D

2012-09-10

Applying high temperature cooling concepts, i.e. high temperature cooling (T(supply) is 16-20°C) HVAC systems, in the built environment allows the reduction in the use of (high quality) energy. However, application of high temperature cooling systems can result in whole body and local discomfort of the occupants. Non-uniform thermal conditions, which may occur due to application of high temperature cooling systems, can be responsible for discomfort. Contradictions in literature exist regarding the validity of the often used predicted mean vote (PMV) index for both genders, and the index is not intended for evaluating the discomfort due to non-uniform environmental conditions. In some cases, however, combinations of local and general discomfort factors, for example draught under warm conditions, may not be uncomfortable. The objective of this study was to investigate gender differences in thermophysiology, thermal comfort and productivity in response to thermal non-uniform environmental conditions. Twenty healthy subjects (10 males and 10 females, age 20-29 years) were exposed to two different experimental conditions: a convective cooling situation (CC) and a radiant cooling situation (RC). During the experiments physiological responses, thermal comfort and productivity were measured. The results show that under both experimental conditions the actual mean thermal sensation votes significantly differ from the PMV-index; the subjects are feeling colder than predicted. Furthermore, the females are more uncomfortable and dissatisfied compared to the males. For females, the local sensations and skin temperatures of the extremities have a significant influence on whole body thermal sensation and are therefore important to consider under non-uniform environmental conditions. Copyright © 2012 Elsevier Inc. All rights reserved.

Health concepts, issues, and experience in the Abakaliki area, Nigeria.

PubMed Central

Chukwuma, C

1994-01-01

Environmental health problems are increasingly receiving global attention. The health of entire nations may not only be affected by adverse environmental conditions, but by nutritional deficiencies that lead to morbidity and mortality. The type and extent of adverse health effects in a population depend on the potential for exposure to some environmental factors and pathogens as well as other environmental variables like industrialization, sanitation conditions, and urbanization. National and international comparisons between health status indicators can reveal the extent of any differences that exist, including dynamic changes in prevailing environmental conditions which may be helpful in characterizing the role of specific risk factors. Improvements in collection of environmental data related to health can help to identify, control, and eliminate many of the factors that are associated with environmental risk in the Abakaliki area of eastern Nigeria. PMID:9644193

Effects of substrata and environmental conditions on ecological succession on historic shipwrecks

NASA Astrophysics Data System (ADS)

González-Duarte, Manuel M.; Fernández-Montblanc, Tomás; Bethencourt, Manuel; Izquierdo, Alfredo

2018-01-01

An understanding of the interactions between biological, chemical and physical dynamics is especially important for the adequate conservation of the Underwater Cultural Heritage. However, while physical and chemical processes are relatively well-investigated, the biological communities associated with these habitats are poorly studied. We compared the sessile community developed on panels of different materials placed on two historical shipwrecks, the Fougueux and the Bucentaure, from the Battle of Trafalgar (October 1805). Six materials used at the construction of vessels at the 18th and 19th centuries were selected: copper, brass, cast iron, carbon steel, pine and oak. The sessile community developed on the panels was studied two and 15 months after their immersion at the water to determine the effects of materials and environmental conditions (sediments, waves, hydrodynamic conditions, temperature and salinity) on ecological succession and the possible implications at the conservation of historical shipwrecks. On the Fougueux, the environmental conditions more strongly influenced the biological succession than the material type, with pioneer colonisers dominating the communities in both sampling periods. On the Bucentaure, exposed to more stable environmental conditions, the sessile community showed differences between sampling periods and among materials at the end of the experiment. Under these more stable environmental conditions, the material type showed a higher influence on the sessile community. Species that produce calcareous concretions developed on metallic panels, but were absent on wood panels, where the shipworm Teredo navalis was more abundant. The relationship between environmental conditions, sessile organisms and material type can influence the conservation status of the archaeological sites.

Studies of adaptive traits of Bali cattle in Buleleng district, Bali and Barru district, South Sulawesi

NASA Astrophysics Data System (ADS)

Aritonang, S. B.; Yuniati, R.; Abinawanto, Imron, M.; Bowolaksono, A.

2017-05-01

Bali cattle have high adaptability, so the distribution area is spread across Indonesia. These studies aimed to determine the effect of environmental factors on physiology performance of Bali cattle in Buleleng district and Barru district. Skin and rectal temperature and respiration rate within a minute were measured in cattle across 5-days. Ambient temperature, relative humidity, wind speed, and light intensity were measured as environmental factors. Our findings suggest that environmental factors between the two districts were different (p<0.05), but the temperature and wind speed were not. In Buleleng, the relative humidity was 82.6 ± 1 4.4% and light intensity was 123.03 ± 24.83 kW/m2, whereas in Barru the relative humidity was 75.4 ± 12.6% and light intensity was 200.96 ± 25.11 kW/m2. Although both regions had different environmental conditions, the respiration rate of cattle was different between the two districts (p<0.05). Cattle respiration rate in Buleleng was 26-34 BPM, whereas in Barru it was 22-28 BPM. Our results indicate that the changes in environmental conditions affect changes in the cattle physiology profile in each district. Thus, Bali cattle have adaptability towards a variety of environmental conditions.

Modelisation spatio-temporelle de la vulnerabilite du milieu a la degradation des sols en milieu semi-aride a partir de donnees radar

NASA Astrophysics Data System (ADS)

Sylla, Daouda

Defined as a process that reduces the potential of soil production or the usefulness of natural resources, soil degradation is a major environmental problem which affects over 41 % of the land and, over 80 % of people affected by this phenomenon live in developing countries. The general objective of the present project is the characterisation of different types of land use and land cover and the detection of their spatio-temporal changes from radar data (ERS-1, RADARSAT-1 and ENVISAT) for a spatio-temporal modeling of environmental vulnerability to soil degradation in semi-arid area. Due to the high sensitivity of the radar signal to the observing conditions of the sensor and the target, a partition of the radar images with respect to their angular configurations (23° and [33°-35°-47°]) and to environmental conditions (wet and dry) was first performed. A good characterisation and a good temporal evolution of the four types of land use and land cover of interest are obtained with different levels of contrast depending on the incidence angles and environmental conditions. In addition to pixel-based approach used for change detection (images differences, Principal component analysis), a monitoring of land cover from an object-oriented approach which focused on two types of land cover is developed. The method allows a detailed mapping of bare soil occurrences as a function of environmental conditions. Finally, using different sources of information, a modeling of the environmental vulnerability to soil degradation is performed in the South-west of Niger from the probabilistic fusion rule of Dempster-Shafer. The resulting decision maps are statistically acceptable at 93 % and 91 % with Kappa values of 86 % and 84 %, for respectively dry and wet conditions. Besides, they are used to produce a global map of the environmental vulnerability to soil degradation in this semi-arid area. Key-words: Environmental vulnerability to soil degradation; data fusion; radar images; land use changes; semi-arid environment; South-west of Niger.

Developing Occupational Programs: A Case Study of Four Arkansas Community Colleges

ERIC Educational Resources Information Center

Doyle, Duane Edward

2011-01-01

This study examines how differences in the environmental conditions and organizational factors facing each community college contribute to the development of occupational and technical education programs. This study was driven by one primary research question: What environmental conditions and organizational factors influence the nature of the…

The effect of local environmental variables on the helminth parasite communities of the pointedbelly frog Leptodactylus podicipinus from ponds in the Pantanal wetlands.

PubMed

Campião, Karla Magalhães; Delatorre, Milena; Rodrigues, Rozangela Batista; da Silva, Reinaldo José; Ferreira, Vanda Lúcia

2012-04-01

Understanding the patterns of species distribution and abundance has been at the core of ecology. In general, these patterns are determined by species dispersion as well as by abiotic and biotic environmental conditions. Similarly, host-parasite relations and the structure of parasite assemblages are also shaped by environmental conditions and landscape composition. Herein, we assessed the influence of environmental variables and parasite species dispersion on the structure of helminth parasites communities in the frog Leptodactylus podicipinus. We sampled 10 ponds and recorded area, depth, altitude, pH, dissolved oxygen, salinity, temperature, and extent of soil, water, and vegetation cover as well as the distances between the ponds. We collected 121 frogs and found 9 helminth taxa; 2 of them were core species (prevalence higher than 50%), which contributed to the relatively high similarity observed among the ponds. Most of the helminths showed some variation in the frequencies of occurrence among communities from different ponds. The change in species composition among ponds was explained by the environmental variables but not by the distance between the ponds. Moreover, the results indicated that local processes (variation in environmental conditions) were more important than the regional processes (species distribution) in determining the structure of parasite communities. The variation in helminth communities among ponds in response to moderate differences in pond environmental characteristics points to the potential of helminth species as indicators of environmental conditions.

Environmental comfort as criteria for energy management: a case study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rhee, E.K.

This study is a field experiment aimed at evaluating environmental comfort by investigating the impact of different environmental conditions on the perceptions, behaviors and performance of building occupants. The development of a prediction model for thermal comfort and the determination of actual energy savings achieved by altering environmental conditions are other major goals of this study. The research approach is a case study applying a pretest-posttest experimental design. An office building in Ann Arbor is selected for the study. It represents a typical office building in terms of design, occupancy, building systems and environmental conditions, suggesting that the study resultsmore » may be applicable to other office settings. It was found that building occupants were satisfied with the pretest environmental conditions which were within the range of current comfort standards, and with the posttest conditions which were lower than current standards. Changes in environmental conditions had little effect on the occupants' perceptions, behavior and performance, although the changes achieved considerable energy savings during the heating season. Among the other major findings, it was demonstrated that psychological factors were more decisive than objective environmental conditions in determining thermal comfort. The study concludes that an energy management program in an office building that is based on 69/sup 0/F indoor temperature, 30% relative humidity, 10-15 cfm/person ventilation rate, 50 fc lighting level, and 105 F domestic hot water can save energy while maintaining environmental comfort among occupants.« less

Biological, habitat, and water quality conditions in the upper Merced River drainage, Yosemite National Park, California, 1993-1996

USGS Publications Warehouse

Brown, Larry R.; Short, Terry M.

1999-01-01

The general conclusion from these studies is that water quality in the upper Merced River was very good from 1993-1996, despite high levels of human activities in some areas. Fish communities did not appear to be a useful indicator of habitat and water quality because of low species richness and the apparent importance of physical barriers in determining species distributions. Measurements of fish densities and size-distributions might be useful, but would be logistically difficult. Benthic algae and benthic invertebrates do appear to be useful in monitoring environmental conditions. Benthic algae may be more sensitive than benthic invertebrates to small environmental differences within years. Benthic algae were also more responsive than benthic invertebrates to differences in discharge between years. Thus, benthic invertebrates may be more useful in comparing environmental conditions between years, independent of discharge conditions.

Influence of environmental variation on the bacterioplankton community and its loss to viral lysis in the Curonian Lagoon

NASA Astrophysics Data System (ADS)

Šulčius, Sigitas; Reunamo, Anna; Paškauskas, Ričardas; Leskinen, Piia

2018-05-01

Coastal lagoons are continuously exposed to strong environmental gradients that determine the distribution and trophic interactions of microbial communities. Therefore, in this study we assessed whether and how environmental changes influence the bacterial community and its vulnerability to viral infection and lysis along the major environmental gradient in the Curonian Lagoon. We found significant differences in bacterial community profiles, their richness and evenness between the riverine, freshwater southern part and the Baltic Sea water intrusion-influenced northern part of the lagoon, suggesting strong environmental control of the structure of bacterial communities. Viruses were found to be play an important role in bacterial mortality in the Curonian Lagoon, being responsible for the removal of 20-50% of the bacterial standing stock. We observed differences in virioplankton decay rates and virus burst sizes between the northern and southern parts of the lagoon. However, no relationships were found between viral activity and bacterial communities within the lagoon ecosystem. The frequency of infected cells and virus-mediated bacterial mortality (VMBM) remained constant among the sampling sites irrespective of differences in bacteria community assemblages and environmental conditions. The results indicate that factors determining changes in bacterial diversity are different from the factors limiting their vulnerability to viral infection and lysis. This study also suggests that under changing environmental conditions, virus-bacteria interactions are more stable than the interacting viral and bacterial communities themselves. These findings are important for understanding the functioning of the coastal ecosystems under the rapidly changing local (spatial and temporal) and global (e.g. eutrophication, climate change) conditions.

Vocal Behavior in Environmental Noise: Comparisons Between Work and Leisure Conditions in Women With Work-related Voice Disorders and Matched Controls.

PubMed

Szabo Portela, Annika; Granqvist, Svante; Ternström, Sten; Södersten, Maria

2018-01-01

This study aimed to assess vocal behavior in women with voice-intensive occupations to investigate differences between patients and controls and between work and leisure conditions with environmental noise level as an experimental factor. Patients with work-related voice disorders, 10 with phonasthenia and 10 with vocal nodules, were matched regarding age, profession, and workplace with 20 vocally healthy colleagues. The sound pressure level of environmental noise and the speakers' voice, fundamental frequency, and phonation ratio were registered from morning to night during 1 week with a voice accumulator. Voice data were assessed in low (≤55 dBA), moderate, and high (>70 dBA) environmental noise levels. The average environmental noise level was significantly higher during the work condition for patients with vocal nodules (73.9 dBA) and their controls (73.0 dBA) compared with patients with phonasthenia (68.3 dBA) and their controls (67.1 dBA). The average voice level and the fundamental frequency were also significantly higher during work for the patients with vocal nodules and their controls. During the leisure condition, there were no significant differences in average noise and voice level nor fundamental frequency between the groups. The patients with vocal nodules and their controls spent significantly more time and used their voices significantly more in high-environmental noise levels. High noise levels during work and demands from the occupation impact vocal behavior. Thus, assessment of voice ergonomics should be part of the work environmental management. To reduce environmental noise levels is important to improve voice ergonomic conditions in communication-intensive and vocally demanding workplaces. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Application of the induced exposure method to compare risks of traffic crashes among different types of drivers under different environmental conditions.

PubMed

Redondo-Calderón, J L; de Luna-del-Castillo , J; Jiménez-Moleón, J J; García-Martín, M; Lardelli-Claret, P; Gálvez-Vargas, R

2001-05-01

The authors used the induced exposure method to compare risks of traffic crashes among different types of Spanish drivers under different environmental conditions. The authors analyzed traffic crashes recorded by the Spanish Dirección General de Tráfico for the years 1991 and 1992 to compare proportions of drivers in different age/sex categories who were involved in single-vehicle and multivehicle crashes under different psychological and physical conditions. Crash risk was 1.42- to 2.35-fold greater in men than in women, depending on driver category and environmental factors. Risk was also significantly higher in the 18- to 24-year-old age group (1.75- to 2.87-fold greater than in drivers aged 25-49 years) and under abnormal psychological-physical conditions (1.69- to 4.10-fold greater among drivers under the influence of alcohol). Twilight and night driving, driving in urban areas, and driving on weekends and legal holidays were also associated, though nonsignificantly, with a slightly higher traffic crash risk. These findings are consistent with earlier reports, and they support the usefulness of the induced exposure method as an easy and economical tool with which to analyze data contained in traffic crash records.

Effects of fire frequency on litter decomposition as mediated by changes to litter chemistry and soil environmental conditions.

PubMed

Ficken, Cari D; Wright, Justin P

2017-01-01

Litter quality and soil environmental conditions are well-studied drivers influencing decomposition rates, but the role played by disturbance legacy, such as fire history, in mediating these drivers is not well understood. Fire history may impact decomposition directly, through changes in soil conditions that impact microbial function, or indirectly, through shifts in plant community composition and litter chemistry. Here, we compared early-stage decomposition rates across longleaf pine forest blocks managed with varying fire frequencies (annual burns, triennial burns, fire-suppression). Using a reciprocal transplant design, we examined how litter chemistry and soil characteristics independently and jointly influenced litter decomposition. We found that both litter chemistry and soil environmental conditions influenced decomposition rates, but only the former was affected by historical fire frequency. Litter from annually burned sites had higher nitrogen content than litter from triennially burned and fire suppression sites, but this was correlated with only a modest increase in decomposition rates. Soil environmental conditions had a larger impact on decomposition than litter chemistry. Across the landscape, decomposition differed more along soil moisture gradients than across fire management regimes. These findings suggest that fire frequency has a limited effect on litter decomposition in this ecosystem, and encourage extending current decomposition frameworks into disturbed systems. However, litter from different species lost different masses due to fire, suggesting that fire may impact decomposition through the preferential combustion of some litter types. Overall, our findings also emphasize the important role of spatial variability in soil environmental conditions, which may be tied to fire frequency across large spatial scales, in driving decomposition rates in this system.

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

USGS Publications Warehouse

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

2012-01-01

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

Effects of fire frequency on litter decomposition as mediated by changes to litter chemistry and soil environmental conditions

PubMed Central

Wright, Justin P.

2017-01-01

Litter quality and soil environmental conditions are well-studied drivers influencing decomposition rates, but the role played by disturbance legacy, such as fire history, in mediating these drivers is not well understood. Fire history may impact decomposition directly, through changes in soil conditions that impact microbial function, or indirectly, through shifts in plant community composition and litter chemistry. Here, we compared early-stage decomposition rates across longleaf pine forest blocks managed with varying fire frequencies (annual burns, triennial burns, fire-suppression). Using a reciprocal transplant design, we examined how litter chemistry and soil characteristics independently and jointly influenced litter decomposition. We found that both litter chemistry and soil environmental conditions influenced decomposition rates, but only the former was affected by historical fire frequency. Litter from annually burned sites had higher nitrogen content than litter from triennially burned and fire suppression sites, but this was correlated with only a modest increase in decomposition rates. Soil environmental conditions had a larger impact on decomposition than litter chemistry. Across the landscape, decomposition differed more along soil moisture gradients than across fire management regimes. These findings suggest that fire frequency has a limited effect on litter decomposition in this ecosystem, and encourage extending current decomposition frameworks into disturbed systems. However, litter from different species lost different masses due to fire, suggesting that fire may impact decomposition through the preferential combustion of some litter types. Overall, our findings also emphasize the important role of spatial variability in soil environmental conditions, which may be tied to fire frequency across large spatial scales, in driving decomposition rates in this system. PMID:29023560

Woodland pond salamander abundance in relation to forest management and environmental conditions in northern Wisconsin

Treesearch

Deahn M. Donner; Christine A. Ribic; Albert J. Beck; Dale Higgins; Dan Eklund; Susan Reinecke

2015-01-01

Woodland ponds are important landscape features that help sustain populations of amphibians that require this aquatic habitat for successful reproduction. Species abundance patterns often reflect site-specific differences in hydrology, physical characteristics, and surrounding vegetation. Large-scale processes such as changing land cover and environmental conditions...

Environmental quality and evolutionary potential: lessons from wild populations

PubMed Central

Charmantier, Anne; Garant, Dany

2005-01-01

An essential requirement to determine a population's potential for evolutionary change is to quantify the amount of genetic variability expressed for traits under selection. Early investigations in laboratory conditions showed that the magnitude of the genetic and environmental components of phenotypic variation can change with environmental conditions. However, there is no consensus as to how the expression of genetic variation is sensitive to different environmental conditions. Recently, the study of quantitative genetics in the wild has been revitalized by new pedigree analyses based on restricted maximum likelihood, resulting in a number of studies investigating these questions in wild populations. Experimental manipulation of environmental quality in the wild, as well as the use of naturally occurring favourable or stressful environments, has broadened the treatment of different taxa and traits. Here, we conduct a meta-analysis on recent studies comparing heritability in favourable versus unfavourable conditions in non-domestic and non-laboratory animals. The results provide evidence for increased heritability in more favourable conditions, significantly so for morphometric traits but not for traits more closely related to fitness. We discuss how these results are explained by underlying changes in variance components, and how they represent a major step in our understanding of evolutionary processes in wild populations. We also show how these trends contrast with the prevailing view resulting mainly from laboratory experiments on Drosophila. Finally, we underline the importance of taking into account the environmental variation in models predicting quantitative trait evolution. PMID:16011915

Impact of different environmental conditions on lithium-ion batteries performance through the thermal monitoring with fiber sensors

NASA Astrophysics Data System (ADS)

Nascimento, Micael; Ferreira, Marta S.; Pinto, João. L.

2017-08-01

In this work, an optical fiber sensing network has been developed to assess the impact of different environmental conditions on lithium batteries performance through the real time thermal monitoring. The battery is submitted to constant current charge and different discharge C-rates, under normal and abusive operating conditions. The results show that for the discharge C-rate of 5.77C, the LiB under cold and dry climates had 32.5% and 27.2% lower temperature variations, when compared with temperate climates, respectively. The higher temperature shift detected in the temperate climate was related to the battery better performance regarding discharge capacity and power capabilities.

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

PubMed

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

2010-01-01

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

Temporally variable environments maintain more beta-diversity in Mediterranean landscapes

NASA Astrophysics Data System (ADS)

Martin, Beatriz; Ferrer, Miguel

2015-10-01

We examined the relationships between different environmental factors and the alpha and beta-diversity of terrestrial vertebrates (birds, mammals, amphibians and reptiles) in a Mediterranean region at the landscape level. We investigated whether the mechanisms underlying alpha and beta-diversity patterns are influenced by energy availability, habitat heterogeneity and temporal variability and if the drivers of the diversity patterns differed between both components of diversity. We defined alpha-diversity as synonym of species richness whereas beta-diversity was measured as distinctiveness. We evaluated a total of 13 different predictors using generalized linear mixed model (GLMM) analysis. Habitat spatial heterogeneity increased alpha-diversity, but contrastingly, it did not significantly affect beta-diversity among sites. Disturbed landscapes may show higher habitat spatial variation and higher alpha-diversity due to the contribution of highly generalist species that are wide-distributed and do not differ in composition (beta-diversity) among different sites within the region. Contrastingly, higher beta-diversity levels were negatively related to more stable sites in terms of temporal environmental variation. This negative relationship between environmental stability and beta-diversity levels is explained in terms of species adaptation to the local environmental conditions. Our study highlights the importance of temporal environmental variability in maintaining beta-diversity patterns under highly variable environmental conditions.

Effects of interaction between temperature conditions and copper exposure on immune defense and other life-history traits of the blow fly Protophormia terraenovae.

PubMed

Pölkki, Mari; Kangassalo, Katariina; Rantala, Markus J

2014-01-01

Environmental pollution is considered one of the major threats to organisms. Direct effects of heavy metal pollution on various life-history traits are well recognized, while the effects of potential interactions between two distinct environmental conditions on different traits are poorly understood. Here, we have tested the effects of interactions between temperature conditions and heavy metal exposure on innate immunity and other life-history traits. Maggots of the blow fly Protophormia terraenovae were reared on either copper-contaminated or uncontaminated food, under three different temperature environments. Encapsulation response, body mass, and development time were measured for adult flies that were not directly exposed to copper. We found that the effects of copper exposure on immunity and other traits are temperature-dependent, suggesting that the ability to regulate toxic compounds in body tissues might depend on temperature conditions. Furthermore, we found that temperature has an effect on sex differences in immune defense. Males had an encapsulation response at higher temperatures stronger than that of females. Our results indicate that the effects of environmental conditions on different traits are much more intricate than what can be predicted. This is something that should be considered when conducting immunological experiments or comparing results of previous studies.

Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis)

PubMed Central

Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

2014-01-01

Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes. PMID:24552840

Multifarious selection through environmental change: acidity and predator-mediated adaptive divergence in the moor frog (Rana arvalis).

PubMed

Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja

2014-04-07

Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes.

Influences of pea morphology and interacting factors on pea aphid (Homoptera: Aphididae) reproduction.

PubMed

Buchman, N; Cuddington, K

2009-08-01

It has been claimed that plant architecture can alter aphid reproductive rates, but the mechanism driving this effect has not been identified. We studied interactions between plant architecture, aphid density, environmental conditions, and nutrient availability on the reproduction of pea aphids [Acyrthosiphon pisum (Harris)] using four near-isogenic peas (Pisum sativum L.) that differ in morphology. Manipulations of aphid density (1, 5, and 10 adults per plant) allowed us to examine any effects of plant morphology on crowding and consequently reproduction. Pea morphology per se did not alter pea aphid crowding, as measured by mean nearest neighbor distance, and there was no effect on reproduction. In addition, reproduction increased with increasing adult density, indicating positive density dependence. In a separate experiment, peas were fertilized to determine whether differences between nutrient availability of the four different morphologies might drive any observed differences in aphid reproduction. Although plant nitrogen content was altered by fertilization treatments, this did not have an impact on aphid reproduction. Greenhouse experiments, however, suggested that pea morphology can interact with environmental conditions to reduce aphid reproduction under some conditions. We conclude that plant morphology only influences aphid reproduction when environmental conditions are less than optimal.

Inoculation Stress Hypothesis of Environmental Enrichment

PubMed Central

Crofton, Elizabeth J.; Zhang, Yafang; Green, Thomas A.

2014-01-01

One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is useful for studying a range of psychiatric conditions, including protective phenotypes in addiction and depression models. The major question is how environmental enrichment, a non-drug and non-surgical manipulation, can produce such robust individual differences in such a wide range of behaviors. This paper draws from a variety of published sources to outline a coherent hypothesis of inoculation stress as a factor producing the protective enrichment phenotypes. The basic tenet suggests that chronic mild stress from living in a complex environment and interacting non-aggressively with conspecifics can inoculate enriched rats against subsequent stressors and/or drugs of abuse. This paper reviews the enrichment phenotypes, mulls the fundamental nature of environmental enrichment vs. isolation, discusses the most appropriate control for environmental enrichment, and challenges the idea that cortisol/corticosterone equals stress. The intent of the inoculation stress hypothesis of environmental enrichment is to provide a scaffold with which to build testable hypotheses for the elucidation of the molecular mechanisms underlying these protective phenotypes and thus provide new therapeutic targets to treat psychiatric/neurological conditions. PMID:25449533

Inoculation stress hypothesis of environmental enrichment.

PubMed

Crofton, Elizabeth J; Zhang, Yafang; Green, Thomas A

2015-02-01

One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is useful for studying a range of psychiatric conditions, including protective phenotypes in addiction and depression models. The major question is how environmental enrichment, a non-drug and non-surgical manipulation, can produce such robust individual differences in such a wide range of behaviors. This paper draws from a variety of published sources to outline a coherent hypothesis of inoculation stress as a factor producing the protective enrichment phenotypes. The basic tenet suggests that chronic mild stress from living in a complex environment and interacting non-aggressively with conspecifics can inoculate enriched rats against subsequent stressors and/or drugs of abuse. This paper reviews the enrichment phenotypes, mulls the fundamental nature of environmental enrichment vs. isolation, discusses the most appropriate control for environmental enrichment, and challenges the idea that cortisol/corticosterone equals stress. The intent of the inoculation stress hypothesis of environmental enrichment is to provide a scaffold with which to build testable hypotheses for the elucidation of the molecular mechanisms underlying these protective phenotypes and thus provide new therapeutic targets to treat psychiatric/neurological conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

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 subjective to the experts' knowledge and experience. Thus, further advancing this approach is needed by developing a scientific method to derive the weights of environmental variables.

Environmental and genetic factors that contribute to Escherichia coli K-12 biofilm formation

PubMed Central

Prüß, Birgit M.; Verma, Karan; Samanta, Priyankar; Sule, Preeti; Kumar, Sunil; Wu, Jianfei; Christianson, David; Horne, Shelley M.; Stafslien, Shane J.; Wolfe, Alan J.; Denton, Anne

2010-01-01

Biofilms are communities of bacteria whose formation on surfaces requires a large portion of the bacteria’s transcriptional network. To identify environmental conditions and transcriptional regulators that contribute to sensing these conditions, we used a high-throughput approach to monitor biofilm biomass produced by an isogenic set of Escherichia coli K-12 strains grown under combinations of environmental conditions. Of the environmental combinationsd, growth in tryptic soy broth at 37°C supported the most biofilm production. To analyze the complex relationships between the diverse cell surface organelles, transcriptional regulators, and metabolic enzymes represented by the tested mutant set, we used a novel vector-item pattern-mining algorithm. The algorithm related biofilm amounts to the functional annotations of each mutated protein. The pattern with the best statistical significance was the gene ontology ‘pyruvate catabolic process,’ which is associated with enzymes of acetate metabolism. Phenotype microarray experiments illustrated that carbon sources that are metabolized to acetyl-coenzyme A, acetyl phosphate, and acetate are particularly supportive of biofilm formation. Scanning electron microscopy revealed structural differences between mutants that lack acetate metabolism enzymes and their parent and confirmed the quantitative differences. We conclude that acetate metabolism functions as a metabolic sensor, transmitting changes in environmental conditions to biofilm biomass and structure. PMID:20559621

Influence of Environmental Factors on Vibrio spp. in Coastal Ecosystems.

PubMed

Johnson, Crystal N

2015-06-01

Various studies have examined the relationships between vibrios and the environmental conditions surrounding them. However, very few reviews have compiled these studies into cohesive points. This may be due to the fact that these studies examine different environmental parameters, use different sampling, detection, and enumeration methodologies, and occur in diverse geographic locations. The current article is one approach to compile these studies into a cohesive work that assesses the importance of environmental determinants on the abundance of vibrios in coastal ecosystems.

The effects of environment on Arctica islandica shell formation and architecture

NASA Astrophysics Data System (ADS)

Milano, Stefania; Nehrke, Gernot; Wanamaker, Alan D., Jr.; Ballesta-Artero, Irene; Brey, Thomas; Schöne, Bernd R.

2017-03-01

Mollusks record valuable information in their hard parts that reflect ambient environmental conditions. For this reason, shells can serve as excellent archives to reconstruct past climate and environmental variability. However, animal physiology and biomineralization, which are often poorly understood, can make the decoding of environmental signals a challenging task. Many of the routinely used shell-based proxies are sensitive to multiple different environmental and physiological variables. Therefore, the identification and interpretation of individual environmental signals (e.g., water temperature) often is particularly difficult. Additional proxies not influenced by multiple environmental variables or animal physiology would be a great asset in the field of paleoclimatology. The aim of this study is to investigate the potential use of structural properties of Arctica islandica shells as an environmental proxy. A total of 11 specimens were analyzed to study if changes of the microstructural organization of this marine bivalve are related to environmental conditions. In order to limit the interference of multiple parameters, the samples were cultured under controlled conditions. Three specimens presented here were grown at two different water temperatures (10 and 15 °C) for multiple weeks and exposed only to ambient food conditions. An additional eight specimens were reared under three different dietary regimes. Shell material was analyzed with two techniques; (1) confocal Raman microscopy (CRM) was used to quantify changes of the orientation of microstructural units and pigment distribution, and (2) scanning electron microscopy (SEM) was used to detect changes in microstructural organization. Our results indicate that A. islandica microstructure is not sensitive to changes in the food source and, likely, shell pigment are not altered by diet. However, seawater temperature had a statistically significant effect on the orientation of the biomineral. Although additional work is required, the results presented here suggest that the crystallographic orientation of biomineral units of A. islandica may serve as an alternative and independent proxy for seawater temperature.

Mapping of recent brachiopod microstructure: A tool for environmental studies.

PubMed

Ye, Facheng; Crippa, Gaia; Angiolini, Lucia; Brand, Uwe; Capitani, GianCarlo; Cusack, Maggie; Garbelli, Claudio; Griesshaber, Erika; Harper, Elizabeth; Schmahl, Wolfgang

2018-03-01

Shells of brachiopods are excellent archives for environmental reconstructions in the recent and distant past as their microstructure and geochemistry respond to climate and environmental forcings. We studied the morphology and size of the basic structural unit, the secondary layer fibre, of the shells of several extant brachiopod taxa to derive a model correlating microstructural patterns to environmental conditions. Twenty-one adult specimens of six recent brachiopod species adapted to different environmental conditions, from Antarctica, to New Zealand, to the Mediterranean Sea, were chosen for microstructural analysis using SEM, TEM and EBSD. We conclude that: 1) there is no significant difference in the shape and size of the fibres between ventral and dorsal valves, 2) there is an ontogenetic trend in the shape and size of the fibres, as they become larger, wider, and flatter with increasing age. This indicates that the fibrous layer produced in the later stages of growth, which is recommended by the literature to be the best material for geochemical analyses, has a different morphostructure and probably a lower organic content than that produced earlier in life. In two species of the same genus living in seawater with different temperature and carbonate saturation state, a relationship emerged between the microstructure and environmental conditions. Fibres of the polar Liothyrella uva tend to be smaller, rounder and less convex than those of the temperate Liothyrella neozelanica, suggesting a relationship between microstructural size, shell organic matter content, ambient seawater temperature and calcite saturation state. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Carbon turnover in topsoil and subsoil: The microbial response to root litter additions and different environmental conditions in a reciprocal soil translocation experiment

NASA Astrophysics Data System (ADS)

Preusser, Sebastian; Poll, Christian; Marhan, Sven; Kandeler, Ellen

2017-04-01

At the global scale, soil organic carbon (SOC) represents the largest active terrestrial organic carbon (OC) pool. Carbon dynamics in subsoil, however, vary from those in topsoil with much lower C concentrations in subsoil than in topsoil horizons, although more than 50 % of SOC is stored in subsoils below 30 cm soil depth. In addition, microorganisms in subsoil are less abundant, more heterogeneously distributed and the microbial communities have a lower diversity than those in topsoil. Especially in deeper soil, the impact of changes in habitat conditions on microorganisms involved in carbon cycling are largely unexplored and consequently the understanding of microbial functioning is limited. A reciprocal translocation experiment allowed us to investigate the complex interaction effects of altered environmental and substrate conditions on microbial decomposer communities in both topsoil and subsoil habitats under in situ conditions. We conducted this experiment with topsoil (5 cm soil depth) and subsoil (110 cm) samples of an acid and sandy Dystric Cambisol from a European beech (Fagus sylvatica L.) forest in Lower Saxony, Germany. In total 144 samples were buried into three depths (5 cm, 45 cm and 110 cm) and 13C-labelled root litter was added to expose the samples to different environmental conditions and to increase the substrate availability, respectively. Samples were taken in three month intervals up to a maximum exposure time of one year to follow the temporal development over the experimental period. Analyses included 13Cmic and 13C PLFA measurements to investigate the response of microbial abundance, community structure and 13C-root decomposition activity under the different treatments. Environmental conditions in the respective soil depths such as soil temperature and water content were recorded throughout the experimental period. All microbial groups (gram+ and gram- bacteria, fungi) showed highest relative 13C incorporation in 110 cm depth and samples with root addition had generally higher microbial abundances than those with no root addition. Here, especially fungi benefited from the additional carbon source with highly increased abundances in all incorporation depths. Also the altered environmental conditions in the different incorporation depths significantly influenced the different microbial groups. The steepest decrease with depth was detected in fungal abundance, while bacteria were less affected and increased in relative abundance in soil samples incorporated into subsoil layers. The highest seasonal variability in microbial abundance, however, was determined in 5 cm incorporation depth demonstrating the higher amplitude in micro-climatic and micro-environmental conditions in this near-surface soil habitat. In summary, this experiment demonstrated that carbon quality and quantity are the main factors restricting fungal abundance in deeper soil layers, while bacterial decomposer communities are adapted to a wider range of habitat conditions.

To predict the niche, model colonization and extinction

USGS Publications Warehouse

Yackulic, Charles B.; Nichols, James D.; Reid, Janice; Der, Ricky

2015-01-01

Ecologists frequently try to predict the future geographic distributions of species. Most studies assume that the current distribution of a species reflects its environmental requirements (i.e., the species' niche). However, the current distributions of many species are unlikely to be at equilibrium with the current distribution of environmental conditions, both because of ongoing invasions and because the distribution of suitable environmental conditions is always changing. This mismatch between the equilibrium assumptions inherent in many analyses and the disequilibrium conditions in the real world leads to inaccurate predictions of species' geographic distributions and suggests the need for theory and analytical tools that avoid equilibrium assumptions. Here, we develop a general theory of environmental associations during periods of transient dynamics. We show that time-invariant relationships between environmental conditions and rates of local colonization and extinction can produce substantial temporal variation in occupancy–environment relationships. We then estimate occupancy–environment relationships during three avian invasions. Changes in occupancy–environment relationships over time differ among species but are predicted by dynamic occupancy models. Since estimates of the occupancy–environment relationships themselves are frequently poor predictors of future occupancy patterns, research should increasingly focus on characterizing how rates of local colonization and extinction vary with environmental conditions.

Phenotypic Effects of Salt and Heat Stress over Three Generations in Arabidopsis thaliana

PubMed Central

Suter, Léonie; Widmer, Alex

2013-01-01

Current and predicted environmental change will force many organisms to adapt to novel conditions, especially sessile organisms such as plants. It is therefore important to better understand how plants react to environmental stress and to what extent genotypes differ in such responses. It has been proposed that adaptation to novel conditions could be facilitated by heritable epigenetic changes induced by environmental stress, independent of genetic variation. Here we assessed phenotypic effects of heat and salt stress within and across three generations using four highly inbred Arabidopsis thaliana genotypes (Col, Cvi, Ler and Sha). Salt stress generally decreased fitness, but genotypes were differently affected, suggesting that susceptibility of A. thaliana to salt stress varies among genotypes. Heat stress at an early rosette stage had less detrimental effects but accelerated flowering in three out of four accessions. Additionally, we found three different modes of transgenerational effects on phenotypes, all harboring the potential of being adaptive: heat stress in previous generations induced faster rosette growth in Sha, both under heat and control conditions, resembling a tracking response, while in Cvi, the phenotypic variance of several traits increased, resembling diversified bet-hedging. Salt stress experienced in earlier generations altered plant architecture of Sha under salt but not control conditions, similar to transgenerational phenotypic plasticity. However, transgenerational phenotypic effects depended on the type of stress as well as on genotype, suggesting that such effects may not be a general response leading to adaptation to novel environmental conditions in A. thaliana. PMID:24244719

Varying susceptibility of clinical and environmental Scedosporium isolates to chemical oxidative stress in conidial germination.

PubMed

Staerck, Cindy; Godon, Charlotte; Bouchara, Jean-Philippe; Fleury, Maxime J J

2018-04-01

Scedosporium species are opportunistic pathogens causing a great variety of infections in both immunocompetent and immunocompromised individuals. The Scedosporium genus ranks the second among the filamentous fungi colonizing the airways of patients with cystic fibrosis (CF), after Aspergillus fumigatus, and most species are capable to chronically colonize the respiratory tract of these patients. Nevertheless, few data are available regarding evasion of the inhaled conidia to the host immune response. Upon microbial infection, macrophages and neutrophils release reactive oxygen species (ROS). To colonize the respiratory tract, the conidia need to germinate despite the oxidative stress generated by phagocytic cells. Germination of spores from different clinical or environmental isolates of the major Scedosporium species was investigated in oxidative stress conditions. All tested species showed susceptibility to oxidative stress. However, when comparing clinical and environmental isolates, differences in germination capabilities under oxidative stress conditions were seen between species as well as within each species. Among environmental isolates, Scedosporium aurantiacum isolates were the most resistant to oxidative stress whereas Scedosporium dehoogii were the most susceptible. Overall, the differences observed between Scedosporium species in the capacity to germinate under oxidative stress conditions could explain their varying prevalence and pathogenicity.

Pyrite oxidation under simulated acid rain weathering conditions.

PubMed

Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

2017-09-01

We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

Environmental enrichment ameliorates depressive-like symptoms in young rats bred for learned helplessness.

PubMed

Richter, S Helene; Zeuch, Benjamin; Riva, Marco A; Gass, Peter; Vollmayr, Barbara

2013-09-01

The incidence of major depression is known to be influenced by both genetic and environmental factors. In the current study, we therefore set out to investigate depressive-like behavior and its modification by environmental enrichment using rats bred for 'learned helplessness'. 45 males of congenitally helpless (cLH, n=22) and non-helpless (cNLH, n=23) rats of two different generations were used to systematically investigate differential effects of environmental enrichment on learned helpless behavior, anhedonic-like behavior (sweetened condensed milk consumption) and spontaneous behavior in the home cage. While enrichment was found to reduce learned helpless behavior in 14 weeks old, but not 28 weeks old cLH rats, it did not affect the consumption of sweetened condensed milk. Regarding the home cage behavior, no consistent changes between rats of different strains, housing conditions, and ages were observed. We could thus demonstrate that a genetic predisposition for learned helplessness may interact with environmental conditions in mediating some, but not all depressive-like symptoms in congenitally learned helpless rats. However, future efforts are needed to isolate the differential benefits of environmental factors in mediating the different depression-related symptoms. Copyright © 2013 Elsevier B.V. All rights reserved.

Fish-based indicators of estuarine condition that do not require reference data

NASA Astrophysics Data System (ADS)

Tweedley, James R.; Warwick, Richard M.; Hallett, Chris S.; Potter, Ian C.

2017-05-01

The species composition of fish communities in 15 microtidal estuaries in south-western Australia, ranging from permanently-open to normally-closed, is shown to be related to the geomorphological and hydrological regimes and not to environmental condition. This study then explored the effectiveness of using qualitative taxonomic distinctness and ABC curves for fish data as indicators of the environmental condition in nearshore, shallow waters of these estuaries and, in the case of taxonomic distinctness, also of their offshore, deeper waters. Neither of these indices require spatial or temporal reference data, which may be either prohibitively expensive and time-consuming to collect or unavailable. Taxonomic distinctness, in both nearshore and offshore waters, varied consistently among estuaries in relation to their recorded environmental status, and is thus a good indicator of overall estuarine condition. ABC analyses, however, did not prove a good measure of the environmental condition of the estuaries, because their results largely reflect differences in accessibility of the estuary to marine estuarine-opportunist species and especially those that grow to a larger size. It is concluded that taxonomic distinctness indices provide a rapid and cost-effective method for assessing the environmental condition of estuaries, particularly those with limited spatial or temporal reference data.

Analysis of Pre-treatment Woody Vegetation and Environmental Data for the Missouri Ozark Forest Ecosystem Project

Treesearch

John M. Kabrick; David R. Larsen; Stephen R. Shifley

1997-01-01

We conducted a study to identify pre-treatment trends in woody species density, diameter, and basal area among MOFEP sites, blocks, and treatment areas; relate woody species differences among sites, blocks, and treatment areas to differences in environmental conditions; and identify potential treatment response differences based upon our fmdings. Sites 2 through 5 had...

Soil conditions drive changes in a key leaf functional trait through environmental filtering and facilitative interactions

NASA Astrophysics Data System (ADS)

Molina-Venegas, Rafael; Aparicio, Abelardo; Lavergne, Sébastien; Arroyo, Juan

2018-01-01

Non-random patterns in the functional structure of communities are often interpreted as evidence for different forces governing their assemblage. However, community assembly processes may act antagonistically, countering each other's signatures on the functional structure of communities, which may lead to spurious inferences on the underlying mechanisms. To illustrate this issue, we assessed the joint effects of environmental filtering and facilitative interactions on a key leaf functional trait (i.e. specific leaf area, SLA) in Mediterranean dwarf-shrub communities, using a two-scale sampling approach. Specifically, we analyzed differences in community-weighted mean SLA values (CWM-SLA) between communities (community-scale) and between guilds within communities (guild-scale, i.e. individuals sampled in understorey, overstorey and open-ground conditions) across contrasted soil environments and elevational gradients. We found that communities on harsh edaphic conditions (i.e. dolomite habitats) showed significantly lower CWM-SLA values than communities on more fertile habitats. In contrast, elevation was a poor predictor of differences in CWM-SLA between the communities. This suggests that environmental filtering may influence leaf trait variation along soil gradients irrespective of elevation. On the other hand, communities on dolomite habitats showed strong differences in CWM-SLA between understorey (higher CWM-SLA) and either open-ground and overstorey guilds (lower CWM-SLA), whereas communities on more fertile soils showed no differences between the guilds. The strong differences in CWM-SLA between understorey and non-understorey guilds in dolomite communities suggest that facilitative interactions may be particularly at stake under stressful edaphic conditions, thus partially mitigating the effect of environmental filtering (i.e. low SLA values) on communities growing in harsh soils.

Phylogeography of an Australian termite, Amitermes laurensis (Isoptera, Termitidae), with special reference to the variety of mound shapes.

PubMed

Ozeki, Masato; Isagi, Yuji; Tsubota, Hiromi; Jacklyn, Peter; Bowman, David M J S

2007-01-01

In northern Australia, the debris-feeding termite Amitermes laurensis builds tall, wedge-shaped mounds in the northern part of Cape York Peninsula and Arnhem Land, where their habitats are seasonally flooded, and small dome shaped mounds in the southeastern part of Cape York Peninsula, where their habitats are well-drained. Phylogeographic analyses were conducted in 238 individuals from 30 populations using the mitochondrial cytochrome oxidase II (COII) gene. DNA sequences of 50 haplotypes were used to construct NJ, MP and ML trees. Phylogenetic trees for 16 Amitermes species showed monophyly of A. laurensis and the variation of A. laurensis mounds did not strongly correspond to the intraspecific phylogeny. It was observed that mounds with the same shape were constructed by phylogenetically different groups under similar environmental conditions and different mounds shapes were built by phylogenetically closely related groups under the different environmental conditions. Thus, phylogenetically close groups of A. laurensis, in different habitats, may adapt to environmental conditions by constructing different mound shapes. We also investigated the phylogeographic structure of A. laurensis. The significant positive correlation between genetic and geographic distances indicated isolation by distance, reflecting restricted dispersal ability of alates. Although the overall genetic structure of A. laurensis showed isolation by distance, we also identified two exceptions: (i) secondary contacts of genetically divergent lineages in southern Cape York Peninsula, and (ii) low genetic differences between geographically separated populations of Cape York Peninsula and Arnhem Land. Therefore, the phylogeography of A. laurensis may reflect continuous gene flow restricted to short distances and past changes of gene flow associated with the fluctuation of environmental conditions accompanying the changing sea levels in the Quaternary.

Responding for a conditioned reinforcer or unconditioned sensory reinforcer in mice: interactions with environmental enrichment, social isolation, and monoamine reuptake inhibitors.

PubMed

Browne, Caleb J; Fletcher, Paul J; Zeeb, Fiona D

2016-03-01

Environmental factors influence the etiology of many psychiatric disorders. Likewise, environmental factors can alter processes central to motivation. Therefore, motivational deficits present in many disorders may be influenced by early life environmental conditions. We examined whether housing animals in different environmental conditions influenced the ability of sensory stimuli to acquire incentive value and whether elevated monoamine activity altered responsing for these stimuli. Isolation-housed (IH), pair-housed (PH), and environmentally enriched (EE) male C57BL/6N mice were examined in tests of responding for a conditioned reinforcer (CRf) or an unconditioned sensory reinforcer (USRf). The CRf was previously paired with saccharin delivery through Pavlovian conditioning, while the USRf was not conditioned with a reward. Following baseline tests of responding for the CRf or USRf, the effects of elevated monoamine activity were examined. At baseline, PH and EE mice responded similarly for the CRf or USRf. IH mice responded more for the CRf but exhibited slower acquisition of responding for the USRf. Administration of citalopram, a serotonin transporter blocker, or atomoxetine, a norepinephrine transporter blocker, decreased responding for the CRf and USRf in all groups. The dopamine transporter blocker GBR 12909 generally increased responding for the CRf and USRf, but further analysis revealed enhanced responding for both reinforcers only in EE mice. Baseline incentive motivation is strongly influenced by the social component of housing conditions. Furthermore, environmental enrichment increased the sensitivity to elevated dopamine activity, while acute elevations in serotonin and norepinephrine inhibit incentive motivation irrespective of housing condition.

Environmental Sustainability and Mold Hygiene in Buildings

PubMed Central

Ng, Tsz Wai; Lai, Ka Man

2018-01-01

Environmental sustainability is one of the key issues in building management. In Hong Kong, one of the initiatives is to reduce the operation hours of air-conditioning in buildings to cut down energy consumption. In this study, we reported a mold contamination case in a newly refurbished laboratory, in which the air-conditioner was switched from 24- to 18-h mode after refurbishment. In order to prevent mold recurrence, the air-conditioner was switched back to 24-h mode in the laboratory. During the mold investigation, visible mold patches in the laboratory were searched and then cultured, counted and identified. Building and environmental conditions were recorded, and used to deduce different causes of mold contamination. Eight contaminated sites including a wall, a bench, some metal and plastic surfaces and seven types of molds including two Cladosporium spp., two Aspergillus spp., one Rhizopus sp., one Trichoderma sp., and one Tritirachium sp. were identified. Cladosporium spp. were the most abundant and frequently found molds in the laboratory. The contaminated areas could have one to five different species on them. Based on the mold and environmental conditions, several scenarios causing the mold contamination were deduced, and different mold control measures were discussed to compare them with the current solution of using 24-h air-conditioning to control mold growth. This study highlights the importance of mold hygiene in sustainable building management. PMID:29617339

Environmental Sustainability and Mold Hygiene in Buildings.

PubMed

Wu, Haoxiang; Ng, Tsz Wai; Wong, Jonathan Wc; Lai, Ka Man

2018-04-04

Environmental sustainability is one of the key issues in building management. In Hong Kong, one of the initiatives is to reduce the operation hours of air-conditioning in buildings to cut down energy consumption. In this study, we reported a mold contamination case in a newly refurbished laboratory, in which the air-conditioner was switched from 24- to 18-h mode after refurbishment. In order to prevent mold recurrence, the air-conditioner was switched back to 24-h mode in the laboratory. During the mold investigation, visible mold patches in the laboratory were searched and then cultured, counted and identified. Building and environmental conditions were recorded, and used to deduce different causes of mold contamination. Eight contaminated sites including a wall, a bench, some metal and plastic surfaces and seven types of molds including two Cladosporium spp., two Aspergillus spp., one Rhizopus sp., one Trichoderma sp., and one Tritirachium sp. were identified. Cladosporium spp. were the most abundant and frequently found molds in the laboratory. The contaminated areas could have one to five different species on them. Based on the mold and environmental conditions, several scenarios causing the mold contamination were deduced, and different mold control measures were discussed to compare them with the current solution of using 24-h air-conditioning to control mold growth. This study highlights the importance of mold hygiene in sustainable building management.

Global cytosine methylation in Daphnia magna depends on genotype, environment, and their interaction.

PubMed

Asselman, Jana; De Coninck, Dieter I M; Vandegehuchte, Michiel B; Jansen, Mieke; Decaestecker, Ellen; De Meester, Luc; Vanden Bussche, Julie; Vanhaecke, Lynn; Janssen, Colin R; De Schamphelaere, Karel A C

2015-05-01

The authors characterized global cytosine methylation levels in 2 different genotypes of the ecotoxicological model organism Daphnia magna after exposure to a wide array of biotic and abiotic environmental stressors. The present study aimed to improve the authors' understanding of the role of cytosine methylation in the organism's response to environmental conditions. The authors observed a significant genotype effect, an environment effect, and a genotype × environment effect. In particular, global cytosine methylation levels were significantly altered after exposure to Triops predation cues, Microcystis, and sodium chloride compared with control conditions. Significant differences between the 2 genotypes were observed when animals were exposed to Triops predation cues, Microcystis, Cryptomonas, and sodium chloride. Despite the low global methylation rate under control conditions (0.49-0.52%), global cytosine methylation levels upon exposure to Triops demonstrated a 5-fold difference between the genotypes (0.21% vs 1.02%). No effects were found in response to arsenic, cadmium, fish, lead, pH of 5.5, pH of 8, temperature, hypoxia, and white fat cell disease. The authors' results point to the potential role of epigenetic effects under changing environmental conditions such as predation (i.e., Triops), diet (i.e., Cryptomonas and Microcystis), and salinity. The results of the present study indicate that, despite global cytosine methylation levels being low, epigenetic effects may be important in environmental studies on Daphnia. © 2015 SETAC.

Microbial community composition and endolith colonization at an Arctic thermal spring are driven by calcite precipitation

USGS Publications Warehouse

Starke, Verena; Kirshtein, Julie; Fogel, Marilyn L.; Steele, Andrew

2013-01-01

Environmental conditions shape community composition. Arctic thermal springs provide an opportunity to study how environmental gradients can impose strong selective pressures on microbial communities and provide a continuum of niche opportunities. We use microscopic and molecular methods to conduct a survey of microbial community composition at Troll Springs on Svalbard, Norway, in the high Arctic. Microorganisms there exist under a wide range of environmental conditions: in warm water as periphyton, in moist granular materials, and in cold, dry rock as endoliths. Troll Springs has two distinct ecosystems, aquatic and terrestrial, together in close proximity, with different underlying environmental factors shaping each microbial community. Periphyton are entrapped during precipitation of calcium carbonate from the spring's waters, providing microbial populations that serve as precursors for the development of endolithic communities. This process differs from most endolith colonization, in which the rock predates the communities that colonize it. Community composition is modulated as environmental conditions change within the springs. At Troll, the aquatic environments show a small number of dominant operational taxonomic units (OTUs) that are specific to each sample. The terrestrial environments show a more even distribution of OTUs common to multiple samples.

Sound level exposure of high-risk infants in different environmental conditions.

PubMed

Byers, Jacqueline F; Waugh, W Randolph; Lowman, Linda B

2006-01-01

To provide descriptive information about the sound levels to which high-risk infants are exposed in various actual environmental conditions in the NICU, including the impact of physical renovation on sound levels, and to assess the contributions of various types of equipment, alarms, and activities to sound levels in simulated conditions in the NICU. Descriptive and comparative design. Convenience sample of 134 infants at a southeastern quarternary children's hospital. A-weighted decibel (dBA) sound levels under various actual and simulated environmental conditions. The renovated NICU was, on average, 4-6 dBA quieter across all environmental conditions than a comparable nonrenovated room, representing a significant sound level reduction. Sound levels remained above consensus recommendations despite physical redesign and staff training. Respiratory therapy equipment, alarms, staff talking, and infant fussiness contributed to higher sound levels. Evidence-based sound-reducing strategies are proposed. Findings were used to plan environment management as part of a developmental, family-centered care, performance improvement program and in new NICU planning.

Altitudinally divergent adult phenotypes in Iberian wall lizards are not driven by egg differences or hatchling growth rates.

PubMed

Ortega, Jesús; López, Pilar; Martín, José

2015-02-01

The interplay between ecological conditions and life histories has been widely acknowledged in vertebrates, particularly in lizards. Environmental conditions may exert different selective pressures and produce divergent phenotypes even in geographically and genetically close populations. The Iberian wall lizard constitutes a perfect model organism as it is considered a species complex with a complicated evolutionary history. Here, we focus on two proximate populations in which we examined adult morphology and reproductive investment of wild-caught lizards along a 500-m altitudinal gradient with contrasting environmental conditions, where adults show marked morphological differences in spite of being closely related. Also, we performed a common garden experiment to examine embryonic and hatchling growth. We focused on reproductive investment per clutch, incubation time, egg size, morphology and growth rate of hatchlings. Results showed clutch size differences between populations that were independent of the larger body size of highland females. However, there were no egg morphological differences between populations, except for egg width, and this difference disappeared after controlling for female body size. Hatchling lizards from both populations did not differ in morphology. Moreover, we did not observe differences between populations or sexes in hatchling growth. Overall, we provide evidence that the differences in adult body size and clutch size are not driven by size at hatching which is not contributed to by egg size, nor are intrinsic hatchling growth rates associated with the environmental conditions experienced in our common garden experiment, suggesting that adult phenotypes are not the result of intrinsic differences between populations.

Investigation of the effect of genotype and agronomic conditions on metabolomic profiles of selected strawberry cultivars with different sensitivity to environmental stress.

PubMed

Akhatou, Ikram; González-Domínguez, Raúl; Fernández-Recamales, Ángeles

2016-04-01

Strawberry is one of the most economically important and widely cultivated fruit crops across the world, so that there is a growing need to develop new analytical methodologies for the authentication of variety and origin, as well as the assessment of agricultural and processing practices. In this work, an untargeted metabolomic strategy based on gas chromatography mass spectrometry (GC-MS) combined with multivariate statistical techniques was used for the first time to characterize the primary metabolome of different strawberry cultivars and to study metabolite alterations in response to multiple agronomic conditions. For this purpose, we investigated three varieties of strawberries with different sensitivity to environmental stress (Camarosa, Festival and Palomar), cultivated in soilless systems using various electrical conductivities, types of coverage and substrates. Metabolomic analysis revealed significant alterations in primary metabolites between the three strawberry cultivars grown under different crop conditions, including sugars (fructose, glucose), organic acids (malic acid, citric acid) and amino acids (alanine, threonine, aspartic acid), among others. Therefore, it could be concluded that GC-MS based metabolomics is a suitable tool to differentiate strawberry cultivars and characterize metabolomic changes associated with environmental and agronomic conditions. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Effects of ambient stimuli on measures of behavioral state and microswitch use in adults with profound multiple impairments.

PubMed

Murphy, Kathleen M; Saunders, Muriel D; Saunders, Richard R; Olswang, Lesley B

2004-01-01

The effects of different types and amounts of environmental stimuli (visual and auditory) on microswitch use and behavioral states of three individuals with profound multiple impairments were examined. The individual's switch use and behavioral states were measured under three setting conditions: natural stimuli (typical visual and auditory stimuli in a recreational situation), reduced visual stimuli, and reduced visual and auditory stimuli. Results demonstrated differential switch use in all participants with the varying environmental setting conditions. No consistent effects were observed in behavioral state related to environmental condition. Predominant behavioral state scores and switch use did not systematically covary with any participant. Results suggest the importance of considering environmental stimuli in relationship to switch use when working with individuals with profound multiple impairments.

Habitat and sex differences in physiological condition of breeding Southwestern Willow Flycatchers (Empidonax traillii extimus)

USGS Publications Warehouse

Owen, J.C.; Sogge, M.K.; Kern, M.D.

2005-01-01

The Southwestern Willow Flycatcher (Empidonax traillii extimus; here- after “flycatcher”) is a federally listed endangered species that breeds in densely vegetated riparian habitats dominated by native and exotic plants, including introduced monotypic saltcedar (Tamarix ramosissima). Some workers have theorized that saltcedar is unsuitable habitat for the flycatcher, primarily because it generally supports a smaller and less diverse invertebrate community (the flycatcher's food base) than native habitats (e.g. Salix spp.). However, differences in insect communities between native and saltcedar habitats are not proof that saltcedar habitats are inferior. The only way to evaluate whether the habitats differ in dietary or energetic quality is to document actual food limitation or its manifestations. Measurements of an individual's body condition and metabolic state can serve as indicators of environmental stressors, such as food limitation and environmental extremes. We captured 130 flycatchers breeding in native and saltcedar habitats in Arizona and New Mexico and measured 12 variables of physiological condition. These variables included body mass, fat level, body condition index, hematocrit, plasma triglycerides, plasma free fatty acids and glycerol, plasma glucose and beta-hydroxybutyrate, plasma uric acid, total leukocyte count, and heterophil-to-lymphocyte ratio. We found substantial sex-based differences in the condition of male and female flycatchers. Ten of the 12 measures of physiological condition differed significantly between the sexes. In all cases where male and female condition differed (except mass), the differences suggest that males were in poorer condition than females. We found few habitat-based differences in flycatcher condition. Only 3 of the 12 physiological condition indices differed significantly between habitats. Our data show that, at least in some parts of the flycatcher's range, there is no evidence that flycatchers breeding in saltcedar habitats exhibit poorer nutritional condition or are suffering negative physiological affects.

Hydro-edaphic conditions defining richness and species composition in savanna areas of the northern Brazilian Amazonia.

PubMed

Araújo, Maria Aparecida de Moura; da Rocha, Antônio Elielson Sousa; Miranda, Izildinha de Souza; Barbosa, Reinaldo Imbrozio

2017-01-01

Studies on plant communities in the Amazon have reported that different hydro-edaphic conditions can affect the richness and the species composition of different ecosystems. However, this aspect is poorly known in the different savanna habitats. Understanding how populations and plant communities are distributed in these open vegetation areas is important to improve the knowledge about which environmental variables influence the occurrence and diversity of plants in this type of regional ecosystem. Thus, this study investigated the richness and composition of plant species in two savanna areas of the northern Brazilian Amazonia, using the coverage (%) of the different life forms observed under different hydro-edaphic conditions as a structural reference. We report 128 plant species classified in 34 botanical families distributed in three savanna habitats with different levels of hydro-edaphic restrictions. In this study, the habitats are conceptually presented and they integrate environmental information (edaphic factors and drainage type), which determines differences between floristic composition, species richness and coverage (%) of plant life forms.

Effects of competing environmental variables and signage on route-choices in simulated everyday and emergency wayfinding situations.

PubMed

Vilar, Elisângela; Rebelo, Francisco; Noriega, Paulo; Duarte, Emília; Mayhorn, Christopher B

2014-01-01

This study examined the relative influence of environmental variables (corridor width and brightness) and signage (directional and exit signs), when presented in competition, on participants' route-choices in two situational variables (everyday vs. emergency), during indoor wayfinding in virtual environments. A virtual reality-based methodology was used. Thus, participants attempted to find a room (everyday situation) in a virtual hotel, followed by a fire-related emergency egress (emergency situation). Different behaviours were observed. In the everyday situation, for no-signs condition, participants choose mostly the wider and brighter corridors, suggesting a heavy reliance on the environmental affordances. Conversely, for signs condition, participants mostly complied with signage, suggesting a greater reliance on the signs rather than on the environmental cues. During emergency, without signage, reliance on environmental affordances seems to be affected by the intersection type. In the sign condition, the reliance on environmental affordances that started strong decreases along the egress route.

The Effect of Team Training Strategies on Team Mental Model Formation and Team Performance under Routine and Non-Routine Environmental Conditions

ERIC Educational Resources Information Center

Hamilton, Katherine L.

2009-01-01

The current study examined how the type of training a team receives (team coordination training vs. cross-training) influences the type of team mental model structures that form and how those mental models in turn impact team performance under different environmental condition (routine vs. non-routine). Three-hundred and fifty-two undergraduate…

Inland Waterway Environmental Safety

NASA Astrophysics Data System (ADS)

Reshnyak, Valery; Sokolov, Sergey; Nyrkov, Anatoliy; Budnik, Vlad

2018-05-01

The article presents the results of development of the main components of the environmental safety when operating vessels on inland waterways, which include strategy selection ensuring the environmental safety of vessels, the selection and justification of a complex of environmental technical means, activities to ensure operation of vessels taking into account the environmental technical means. Measures to ensure environmental safety are developed on the basis of the principles aimed at ensuring environmental safety of vessels. They include the development of strategies for the use of environmental protection equipment, which are determined by the conditions for wastewater treatment of purified sewage and oily bilge water as well as technical characteristics of the vessels, the introduction of the process of the out-of-the-vessel processing of ship pollution as a technology for their movement. This must take into account the operating conditions of vessels on different sections of waterways. An algorithm of actions aimed at ensuring ecological safety of operated vessels is proposed.

THE VARIED INFLUENCE OF SES ON ENVIRONMENTAL CONCERN

PubMed Central

Pampel, Fred C.

2013-01-01

Objective Cross-national studies have found positive relationships of socioeconomic status (SES) with environmental concern at the individual level but have not systematically examined how the relationships may differ across nations. Such comparisons have relevance to identifying the generality of theories of postmaterialism, affluence, and global environmentalism. Methods This study specifies how the individual-level influence of SES varies across national contexts and tests predictions using four waves of the World Values Survey on up to 96 nations. Results The results show that SES is associated only weakly with environmental concern in lower income nations with poor environmental conditions but is associated strongly and positively in higher income nations with better environmental conditions. Conclusion SES has a contingent relationship with environmental concern such that the global environmentalism theory receives support for lower income nations, while the postmaterialism and affluence theories receive support for higher income nations. PMID:24678128

Shifts on reproductive phenology of tropical cerrado savanna trees and climate changes

NASA Astrophysics Data System (ADS)

Morellato, Patricia

2010-05-01

Phenology is the study of cyclic biological events and its relationship to abiotic factors. Timing of flowering, fruiting and leafing is highly correlated to environmental factors such as temperature, precipitation, irradiance and isolation. Accordingly, any change in these factors may have a direct effect on the initiation, intensity and duration of different phenophases. Tropical phenology has not contributed much for climatic change research since historical data sets are scarce and the absence of sharp seasons and distinct factors driving phenology makes difficult the detection of changes over time. One way to have insights on climate driven phenology shifts on tropical plants is through the comparison of plant phenology under different environmental conditions. Fragmentation of natural landscape has exposed plants to edge effects - the interaction between two adjacent ecosystems, when the two are separated by an abrupt transition - the edge, including both abiotic and biological changes on environmental conditions that likely affect plant phenology. The microclimatic conditions along edges have important direct biological effects on the reproductive phenology and fitness of plant species. One can expected that the abiotic edge effects on plant phenology may be similar to some extent to certain effects induced by climate change on plant phenology since both involve shifts on environmental conditions. Due to the threatened status and rich biodiversity of Brazilian Neotropical savanna, or the Brazilian Cerrado, the present study aimed to understand edge effects on cerrado savanna species. We compared micro environmental factors and phenology of several species on the edge and in the interior of cerrado savanna. Our first results indicated that shifts on the micro environmental condition may have driven changes in time, duration and intensity of species phenology and may give us insights on savanna responses to climate changes.

Two by two, inch by inch: Height as an indicator of environmental conditions during childhood and its influence on earnings over the life cycle among twins.

PubMed

Lång, Elisabeth; Nystedt, Paul

2018-02-01

Adult height is a function of genetic predispositions and environmental influences during childhood. Hence, any variation in height among monozygotic twins, who share genetic predispositions, is bound to reflect differences in their environmental exposure. Therefore, a height premium in earnings among monozygotic twins also reflects such exposure. In this study, we analyze the height premium over the life cycle among Swedish twins, 10,000 of whom are monozygotic. The premium is relatively constant over the life cycle, amounting to 5-6% higher earnings per decimeter for men and less for women, suggesting that environmental conditions in childhood and youth affect earnings over most of the adult life course. The premium is larger below median height for men and above median height for young women. The estimates are similar for monozygotic and dizygotic twins, indicating that environmentally and genetically induced height differences are similarly associated with earnings. Copyright © 2017 Elsevier B.V. All rights reserved.

Diversity and interactions of microbial functional genes under differing environmental conditions: insights from a membrane bioreactor and an oxidation ditch.

PubMed

Xia, Yu; Hu, Man; Wen, Xianghua; Wang, Xiaohui; Yang, Yunfeng; Zhou, Jizhong

2016-01-08

The effect of environmental conditions on the diversity and interactions of microbial communities has caused tremendous interest in microbial ecology. Here, we found that with identical influents but differing operational parameters (mainly mixed liquor suspended solid (MLSS) concentrations, solid retention time (SRT) and dissolved oxygen (DO) concentrations), two full-scale municipal wastewater treatment systems applying oxidation ditch (OD) and membrane bioreactor (MBR) processes harbored a majority of shared genes (87.2%) but had different overall functional gene structures as revealed by two datasets of 12-day time-series generated by a functional gene array-GeoChip 4.2. Association networks of core carbon, nitrogen and phosphorus cycling genes in each system based on random matrix theory (RMT) showed different topological properties and the MBR nodes showed an indication of higher connectivity. MLSS and DO were shown to be effective in shaping functional gene structures of the systems by statistical analyses. Higher MLSS concentrations resulting in decreased resource availability of the MBR system were thought to promote positive interactions of important functional genes. Together, these findings show the differences of functional potentials of some bioprocesses caused by differing environmental conditions and suggest that higher stress of resource limitation increased positive gene interactions in the MBR system.

Diversity and interactions of microbial functional genes under differing environmental conditions: insights from a membrane bioreactor and an oxidation ditch

NASA Astrophysics Data System (ADS)

Xia, Yu; Hu, Man; Wen, Xianghua; Wang, Xiaohui; Yang, Yunfeng; Zhou, Jizhong

2016-01-01

The effect of environmental conditions on the diversity and interactions of microbial communities has caused tremendous interest in microbial ecology. Here, we found that with identical influents but differing operational parameters (mainly mixed liquor suspended solid (MLSS) concentrations, solid retention time (SRT) and dissolved oxygen (DO) concentrations), two full-scale municipal wastewater treatment systems applying oxidation ditch (OD) and membrane bioreactor (MBR) processes harbored a majority of shared genes (87.2%) but had different overall functional gene structures as revealed by two datasets of 12-day time-series generated by a functional gene array-GeoChip 4.2. Association networks of core carbon, nitrogen and phosphorus cycling genes in each system based on random matrix theory (RMT) showed different topological properties and the MBR nodes showed an indication of higher connectivity. MLSS and DO were shown to be effective in shaping functional gene structures of the systems by statistical analyses. Higher MLSS concentrations resulting in decreased resource availability of the MBR system were thought to promote positive interactions of important functional genes. Together, these findings show the differences of functional potentials of some bioprocesses caused by differing environmental conditions and suggest that higher stress of resource limitation increased positive gene interactions in the MBR system.

Diversity and interactions of microbial functional genes under differing environmental conditions: insights from a membrane bioreactor and an oxidation ditch

PubMed Central

Xia, Yu; Hu, Man; Wen, Xianghua; Wang, Xiaohui; Yang, Yunfeng; Zhou, Jizhong

2016-01-01

The effect of environmental conditions on the diversity and interactions of microbial communities has caused tremendous interest in microbial ecology. Here, we found that with identical influents but differing operational parameters (mainly mixed liquor suspended solid (MLSS) concentrations, solid retention time (SRT) and dissolved oxygen (DO) concentrations), two full-scale municipal wastewater treatment systems applying oxidation ditch (OD) and membrane bioreactor (MBR) processes harbored a majority of shared genes (87.2%) but had different overall functional gene structures as revealed by two datasets of 12-day time-series generated by a functional gene array-GeoChip 4.2. Association networks of core carbon, nitrogen and phosphorus cycling genes in each system based on random matrix theory (RMT) showed different topological properties and the MBR nodes showed an indication of higher connectivity. MLSS and DO were shown to be effective in shaping functional gene structures of the systems by statistical analyses. Higher MLSS concentrations resulting in decreased resource availability of the MBR system were thought to promote positive interactions of important functional genes. Together, these findings show the differences of functional potentials of some bioprocesses caused by differing environmental conditions and suggest that higher stress of resource limitation increased positive gene interactions in the MBR system. PMID:26743465

A tale of trade-offs: the impact of macroeconomic factors on environmental concern.

PubMed

Conroy, Stephen J; Emerson, Tisha L N

2014-12-01

We test whether macroeconomic conditions affect individuals' willingness to pay for environmental quality improvements. Improvements in environmental quality, like everything, come at a cost. Individuals facing difficult economic times may be less willing to make trade-offs required for improvements in environmental quality. Using somewhat different methodologies and shorter time frames, prior investigations have generally found a direct relationship between willingness to pay for environmental improvements and macroeconomic conditions. We use a nearly 40-year span (27 periods) of the General Social Survey (1974-2012) to estimate attitudes toward environmental spending while controlling for U.S. macroeconomic conditions and respondent-specific factors such as age, gender, marital status, number of children, residential location, educational attainment, personal financial condition, political party affiliation and ideology. Macroeconomic conditions include one-year lagged controls for the unemployment rate, the rate of economic growth (percentage change in real GDP), and an indicator for whether the U.S. economy was experiencing a recession. We find that, in general, when economic conditions are unfavorable (i.e., during a recession, or with higher unemployment, or lower GDP growth), respondents are more likely to believe the U.S. is spending too much on "improving and protecting the environment". Interacting lagged macroeconomic controls with respondent's income, we find that these views are at least partially offset by the respondent's own economic condition (i.e., their own real income). Our findings are consistent with the notion that environmental quality is a normal, or procyclical good, i.e., that environmental spending should rise when the economy is expanding and fall during economic contractions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Power requirements and environmental impact of a pedelec. A case study based on real-life applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abagnale, Carmelina, E-mail: c.abagnale@unina.it; Cardone, Massimo, E-mail: massimo.cardone@unina.it; Iodice, Paolo, E-mail: paolo.iodice@unina.it

2015-07-15

This paper describes the methodologies to appraise the power requests and environmental analysis of an electrically assisted bicycle under real driving conditions, also containing regulations and technical-science-related aspects. For this purpose, in this study, the on-road test program of an electrically assisted bicycle was executed in the urban area of Naples on different test tracks, so a general assessment about its driving behavior under several driving conditions was performed. The power requirements in different typical riding situations were estimated by a procedure based on the experimental kinematic parameters that characterize the driving dynamics collected during the real-life applications. An environmentalmore » analysis was also performed, with a methodology that takes into account the environmental assessment of a moped by measuring the experimental moped exhaust emissions of the regulated pollutants. Starting from the results acquired during the different test samples, besides, an assessment of the electric traction offered by this pedelec on the driving comfort was evaluated for different riding situations. - Highlights: • The power requirements of a pedelec in typical riding conditions were identified. • The estimated electricity consumption for battery recharging was defined. • An environmental valuation of the tested pedelec and of a moped was performed. • Emissions that could be saved utilizing a pedelec instead of a moped were derived.« less

Malate as a key carbon source of leaf dark-respired CO2 across different environmental conditions in potato plants

PubMed Central

Lehmann, Marco M.; Rinne, Katja T.; Blessing, Carola; Siegwolf, Rolf T. W.; Buchmann, Nina; Werner, Roland A.

2015-01-01

Dissimilation of carbon sources during plant respiration in support of metabolic processes results in the continuous release of CO2. The carbon isotopic composition of leaf dark-respired CO2 (i.e. δ 13 C R) shows daily enrichments up to 14.8‰ under different environmental conditions. However, the reasons for this 13C enrichment in leaf dark-respired CO2 are not fully understood, since daily changes in δ13C of putative leaf respiratory carbon sources (δ 13 C RS) are not yet clear. Thus, we exposed potato plants (Solanum tuberosum) to different temperature and soil moisture treatments. We determined δ 13 C R with an in-tube incubation technique and δ 13 C RS with compound-specific isotope analysis during a daily cycle. The highest δ 13 C RS values were found in the organic acid malate under different environmental conditions, showing less negative values compared to δ 13 C R (up to 5.2‰) and compared to δ 13 C RS of soluble carbohydrates, citrate and starch (up to 8.8‰). Moreover, linear relationships between δ 13 C R and δ 13 C RS among different putative carbon sources were strongest for malate during daytime (r2=0.69, P≤0.001) and nighttime (r2=0.36, P≤0.001) under all environmental conditions. A multiple linear regression analysis revealed δ 13 C RS of malate as the most important carbon source influencing δ 13 C R. Thus, our results strongly indicate malate as a key carbon source of 13C enriched dark-respired CO2 in potato plants, probably driven by an anapleurotic flux replenishing intermediates of the Krebs cycle. PMID:26139821

Environmental modelling of use of treated organic waste on agricultural land: a comparison of existing models for life cycle assessment of waste systems.

PubMed

Hansen, Trine Lund; Christensen, Thomas Højlund; Schmidt, Sonia

2006-04-01

Modelling of environmental impacts from the application of treated organic municipal solid waste (MSW) in agriculture differs widely between different models for environmental assessment of waste systems. In this comparative study five models were examined concerning quantification and impact assessment of environmental effects from land application of treated organic MSW: DST (Decision Support Tool, USA), IWM (Integrated Waste Management, U.K.), THE IFEU PROJECT (Germany), ORWARE (ORganic WAste REsearch, Sweden) and EASEWASTE (Environmental Assessment of Solid Waste Systems and Technologies, Denmark). DST and IWM are life cycle inventory (LCI) models, thus not performing actual impact assessment. The DST model includes only one water emission (biological oxygen demand) from compost leaching in the results and IWM considers only air emissions from avoided production of commercial fertilizers. THE IFEU PROJECT, ORWARE and EASEWASTE are life cycle assessment (LCA) models containing more detailed land application modules. A case study estimating the environmental impacts from land application of 1 ton of composted source sorted organic household waste was performed to compare the results from the different models and investigate the origin of any difference in type or magnitude of the results. The contributions from the LCI models were limited and did not depend on waste composition or local agricultural conditions. The three LCA models use the same overall approach for quantifying the impacts of the system. However, due to slightly different assumptions, quantification methods and environmental impact assessment, the obtained results varied clearly between the models. Furthermore, local conditions (e.g. soil type, farm type, climate and legal regulation) and waste composition strongly influenced the results of the environmental assessment.

Proteome Analysis of Borrelia burgdorferi Response to Environmental Change

DOE Office of Scientific and Technical Information (OSTI.GOV)

Angel, Thomas E.; Luft, Benjamin J.; Yang, Xiaohua

2010-11-02

We examined global changes in protein expression in the B31 strain of Borrelia burgdorferi, in response to two environmental cues (pH and temperature) chosen for their reported similarity to those encountered at different stages of the organism’s life cycle. Multidimensional nano-liquid chromatographic separations coupled with tandem mass spectrometry were used to examine the array of proteins (i.e., the proteome) of B. burgdorferi for different pH and temperature culture conditions. Changes in pH and temperature elicited in vitro adaptations of this spirochete known to cause Lyme disease and led to alterations in protein expression that are associated with increased microbial pathogenesis.more » We identified 1031 proteins that represent 59% of the annotated genome of B. burgdorferi and elucidated a core proteome of 414 proteins that were present in all environmental conditions investigated. Observed changes in protein abundances indicated varied replicon usage, as well as proteome functional distributions between the in vitro cell culture conditions. Surprisingly, the pH and temperature conditions that mimicked B. burgdorferi residing in the gut of a fed tick showed a marked reduction in protein diversity. Additionally, the results provide us with leading candidates for exploring how B. burgdorferi adapts to and is able to survive in a wide variety of environmental conditions and lay a foundation for planned in situ studies of B. burgdorferi isolated from the tick midgut and infected animals.« less

A Causal Relationship of Occupational Stress among University Employees.

PubMed

Kaewanuchit, Chonticha; Muntaner, Carles; Isha, Nizam

2015-07-01

Occupational stress is a psychosocial dimension of occupational health concept on social determinants of health, especially, job & environmental condition. Recently, staff network of different government universities of Thailand have called higher education commission, and Ministry of Education, Thailand to resolve the issue of government education policy (e.g. wage inequity, poor welfare, law, and job & environment condition) that leads to their job insecurity, physical and mental health problems from occupational stress. The aim of this study was to investigate a causal relationship of occupational stress among the academic university employees. This cross sectional research was conducted in 2014 among 2,000 academic university employees at Thai government universities using stratified random sampling. Independent variables were wage, family support, periods of duty, and job & environmental condition. Dependent variable was stress. Job & environmental condition, as social and environmental factor, and periods of duty as individual factor had direct effect to stress (P< 0.05). Family support, as family factor, and wage, as individual factor had direct effect to stress (P < 0.05). Both family support and wage were the causal endogenous variables. Job & environmental condition and periods of duty were increased so that it associated with occupational stress among academic university employees at moderate level.

Inter- and Intra-Specific Differences in Foliar N Concentrations of Juvenile Loblolly and Slash Pine in North Florida

Treesearch

Yu Xiao; Eric J. Jokela; Tim L. White; Dudley A. Huber

2002-01-01

Differences in foliar N concentrations among species, families, and clones may contribute to variation in relative growth performance under varying environmental conditions. Only limited information exists regarding the importance of genetic vs. environmental controls on the nutritional characteristics of loblolly and slash pine. Knowledge of these processes may...

Conditions during adulthood affect cohort-specific reproductive success in an Arctic-nesting goose population.

PubMed

Weegman, Mitch D; Bearhop, Stuart; Hilton, Geoff M; Walsh, Alyn; Fox, Anthony David

2016-01-01

Variation in fitness between individuals in populations may be attributed to differing environmental conditions experienced among birth (or hatch) years (i.e., between cohorts). In this study, we tested whether cohort fitness could also be explained by environmental conditions experienced in years post-hatch, using 736 lifelong resighting histories of Greenland white-fronted geese (Anser albifrons flavirostris) marked in their first winter. Specifically, we tested whether variation in age at first successful reproduction, the size of the first successful brood and the proportion of successful breeders by cohort was explained by environmental conditions experienced on breeding areas in west Greenland during hatch year, those in adulthood prior to successful reproduction and those in the year of successful reproduction, using North Atlantic Oscillation indices as proxies for environmental conditions during these periods. Fifty-nine (8%) of all marked birds reproduced successfully (i.e., were observed on wintering areas with young) only once in their lifetime and 15 (2%) reproduced successfully twice or thrice. Variation in age at first successful reproduction was explained by the environmental conditions experienced during adulthood in the years prior to successful reproduction. Birds bred earliest (mean age 4) when environmental conditions were 'good' prior to the year of successful reproduction. Conversely, birds successfully reproduced at older ages (mean age 7) if they experienced adverse conditions prior to the year of successful reproduction. Hatch year conditions and an interaction between those experienced prior to and during the year of successful reproduction explained less (marginally significant) variation in age at first successful reproduction. Environmental conditions did not explain variation in the size of the first successful brood or the proportion of successful breeders. These findings show that conditions during adulthood prior to the year of successful reproduction are most important in determining the age at first successful reproduction in Greenland white-fronted geese. Very few birds bred successfully at all (most only once), which suggests that May environmental conditions on breeding areas have cohort effects that influence lifetime (and not just annual) reproductive success.

Urban Tree Species Show the Same Hydraulic Response to Vapor Pressure Deficit across Varying Tree Size and Environmental Conditions

PubMed Central

Chen, Lixin; Zhang, Zhiqiang; Ewers, Brent E.

2012-01-01

Background The functional convergence of tree transpiration has rarely been tested for tree species growing under urban conditions even though it is of significance to elucidate the relationship between functional convergence and species differences of urban trees for establishing sustainable urban forests in the context of forest water relations. Methodology/Principal Findings We measured sap flux of four urban tree species including Cedrus deodara, Zelkova schneideriana, Euonymus bungeanus and Metasequoia glyptostroboides in an urban park by using thermal dissipation probes (TDP). The concurrent microclimate conditions and soil moisture content were also measured. Our objectives were to examine 1) the influence of tree species and size on transpiration, and 2) the hydraulic control of urban trees under different environmental conditions over the transpiration in response to VPD as represented by canopy conductance. The results showed that the functional convergence between tree diameter at breast height (DBH) and tree canopy transpiration amount (E c) was not reliable to predict stand transpiration and there were species differences within same DBH class. Species differed in transpiration patterns to seasonal weather progression and soil water stress as a result of varied sensitivity to water availability. Species differences were also found in their potential maximum transpiration rate and reaction to light. However, a same theoretical hydraulic relationship between G c at VPD = 1 kPa (G cref) and the G c sensitivity to VPD (−dG c/dlnVPD) across studied species as well as under contrasting soil water and R s conditions in the urban area. Conclusions/Significance We concluded that urban trees show the same hydraulic regulation over response to VPD across varying tree size and environmental conditions and thus tree transpiration could be predicted with appropriate assessment of G cref. PMID:23118904

Urban tree species show the same hydraulic response to vapor pressure deficit across varying tree size and environmental conditions.

PubMed

Chen, Lixin; Zhang, Zhiqiang; Ewers, Brent E

2012-01-01

The functional convergence of tree transpiration has rarely been tested for tree species growing under urban conditions even though it is of significance to elucidate the relationship between functional convergence and species differences of urban trees for establishing sustainable urban forests in the context of forest water relations. We measured sap flux of four urban tree species including Cedrus deodara, Zelkova schneideriana, Euonymus bungeanus and Metasequoia glyptostroboides in an urban park by using thermal dissipation probes (TDP). The concurrent microclimate conditions and soil moisture content were also measured. Our objectives were to examine 1) the influence of tree species and size on transpiration, and 2) the hydraulic control of urban trees under different environmental conditions over the transpiration in response to VPD as represented by canopy conductance. The results showed that the functional convergence between tree diameter at breast height (DBH) and tree canopy transpiration amount (E(c)) was not reliable to predict stand transpiration and there were species differences within same DBH class. Species differed in transpiration patterns to seasonal weather progression and soil water stress as a result of varied sensitivity to water availability. Species differences were also found in their potential maximum transpiration rate and reaction to light. However, a same theoretical hydraulic relationship between G(c) at VPD = 1 kPa (G(cref)) and the G(c) sensitivity to VPD (-dG(c)/dlnVPD) across studied species as well as under contrasting soil water and R(s) conditions in the urban area. We concluded that urban trees show the same hydraulic regulation over response to VPD across varying tree size and environmental conditions and thus tree transpiration could be predicted with appropriate assessment of G(cref).

Local versus Generalized Phenotypes in Two Sympatric Aurelia Species: Understanding Jellyfish Ecology Using Genetics and Morphometrics

PubMed Central

Chiaverano, Luciano M.; Bayha, Keith W.; Graham, William M.

2016-01-01

For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gradients, it is necessary to account for potential genetic differences contributing to morphological differentiation. In this study, we set out to quantify geographic morphological variation in the moon jellyfish Aurelia exposed at the extremes of a latitudinal environmental gradient in the Gulf of Mexico (GoM). We used morphological data based on 28 characters, and genetic data taken from mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1). Molecular analyses revealed the presence of two genetically distinct species of Aurelia co-occurring in the GoM: Aurelia sp. 9 and Aurelia c.f. sp. 2, named for its divergence from (for COI) and similarity to (for ITS-1) Aurelia sp. 2 (Brazil). Neither species exhibited significant population genetic structure between the Northern and the Southeastern Gulf of Mexico; however, they differed greatly in the degree of geographic morphological variation. The morphology of Aurelia sp. 9 exhibited ecophenotypic plasticity and varied significantly between locations, while morphology of Aurelia c.f. sp. 2 was geographically invariant (i.e., canalized). The plastic, generalist medusae of Aurelia sp. 9 are likely able to produce environmentally-induced, “optimal” phenotypes that confer high relative fitness in different environments. In contrast, the non-plastic generalist individuals of Aurelia c.f. sp. 2 likely produce environmentally-independent phenotypes that provide the highest fitness across environments. These findings suggest the two Aurelia lineages co-occurring in the GoM were likely exposed to different past environmental conditions (i.e., different selective pressures) and evolved different strategies to cope with environmental variation. This study highlights the importance of using genetics and morphometric data to understand jellyfish ecology, evolution and systematics. PMID:27332545

Local versus Generalized Phenotypes in Two Sympatric Aurelia Species: Understanding Jellyfish Ecology Using Genetics and Morphometrics.

PubMed

Chiaverano, Luciano M; Bayha, Keith W; Graham, William M

2016-01-01

For individuals living in environmentally heterogeneous environments, a key component for adaptation and persistence is the extent of phenotypic differentiation in response to local environmental conditions. In order to determine the extent of environmentally induced morphological variation in a natural population distributed along environmental gradients, it is necessary to account for potential genetic differences contributing to morphological differentiation. In this study, we set out to quantify geographic morphological variation in the moon jellyfish Aurelia exposed at the extremes of a latitudinal environmental gradient in the Gulf of Mexico (GoM). We used morphological data based on 28 characters, and genetic data taken from mitochondrial cytochrome oxidase I (COI) and nuclear internal transcribed spacer 1 (ITS-1). Molecular analyses revealed the presence of two genetically distinct species of Aurelia co-occurring in the GoM: Aurelia sp. 9 and Aurelia c.f. sp. 2, named for its divergence from (for COI) and similarity to (for ITS-1) Aurelia sp. 2 (Brazil). Neither species exhibited significant population genetic structure between the Northern and the Southeastern Gulf of Mexico; however, they differed greatly in the degree of geographic morphological variation. The morphology of Aurelia sp. 9 exhibited ecophenotypic plasticity and varied significantly between locations, while morphology of Aurelia c.f. sp. 2 was geographically invariant (i.e., canalized). The plastic, generalist medusae of Aurelia sp. 9 are likely able to produce environmentally-induced, "optimal" phenotypes that confer high relative fitness in different environments. In contrast, the non-plastic generalist individuals of Aurelia c.f. sp. 2 likely produce environmentally-independent phenotypes that provide the highest fitness across environments. These findings suggest the two Aurelia lineages co-occurring in the GoM were likely exposed to different past environmental conditions (i.e., different selective pressures) and evolved different strategies to cope with environmental variation. This study highlights the importance of using genetics and morphometric data to understand jellyfish ecology, evolution and systematics.

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.

Transcriptome responses to temperature, water availability and photoperiod are conserved among mature trees of two divergent Douglas-fir provenances from a coastal and an interior habitat.

PubMed

Hess, Moritz; Wildhagen, Henning; Junker, Laura Verena; Ensminger, Ingo

2016-08-26

Local adaptation and phenotypic plasticity are important components of plant responses to variations in environmental conditions. While local adaptation has been widely studied in trees, little is known about plasticity of gene expression in adult trees in response to ever changing environmental conditions in natural habitats. Here we investigate plasticity of gene expression in needle tissue between two Douglas-fir provenances represented by 25 adult trees using deep RNA sequencing (RNA-Seq). Using linear mixed models we investigated the effect of temperature, soil water availability and photoperiod on the abundance of 59189 detected transcripts. Expression of more than 80 % of all identified transcripts revealed a response to variations in environmental conditions in the field. GO term overrepresentation analysis revealed gene expression responses to temperature, soil water availability and photoperiod that are highly conserved among many plant taxa. However, expression differences between the two Douglas-fir provenances were rather small compared to the expression differences observed between individual trees. Although the effect of environment on global transcript expression was high, the observed genotype by environment (GxE) interaction of gene expression was surprisingly low, since only 21 of all detected transcripts showed a GxE interaction. The majority of the transcriptome responses in plant leaf tissue is driven by variations in environmental conditions. The small variation between individuals and populations suggests strong conservation of this response within Douglas-fir. Therefore we conclude that plastic transcriptome responses to variations in environmental conditions are only weakly affected by local adaptation in Douglas-fir.

Considerations of Environmentally Relevant Test Conditions for Improved Evaluation of Ecological Hazards of Engineered Nanomaterials

EPA Science Inventory

Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant ...

Changes in the Size of the Active Microbial Pool Explain Short-Term Soil Respiratory Responses to Temperature and Moisture

PubMed Central

Salazar-Villegas, Alejandro; Blagodatskaya, Evgenia; Dukes, Jeffrey S.

2016-01-01

Heterotrophic respiration contributes a substantial fraction of the carbon flux from soil to atmosphere, and responds strongly to environmental conditions. However, the mechanisms through which short-term changes in environmental conditions affect microbial respiration still remain unclear. Microorganisms cope with adverse environmental conditions by transitioning into and out of dormancy, a state in which they minimize rates of metabolism and respiration. These transitions are poorly characterized in soil and are generally omitted from decomposition models. Most current approaches to model microbial control over soil CO2 production relate responses to total microbial biomass (TMB) and do not differentiate between microorganisms in active and dormant physiological states. Indeed, few data for active microbial biomass (AMB) exist with which to compare model output. Here, we tested the hypothesis that differences in soil microbial respiration rates across various environmental conditions are more closely related to differences in AMB (e.g., due to activation of dormant microorganisms) than in TMB. We measured basal respiration (SBR) of soil incubated for a week at two temperatures (24 and 33°C) and two moisture levels (10 and 20% soil dry weight [SDW]), and then determined TMB, AMB, microbial specific growth rate, and the lag time before microbial growth (tlag) using the Substrate-Induced Growth Response (SIGR) method. As expected, SBR was more strongly correlated with AMB than with TMB. This relationship indicated that each g active biomass C contributed ~0.04 g CO2-C h−1 of SBR. TMB responded very little to short-term changes in temperature and soil moisture and did not explain differences in SBR among the treatments. Maximum specific growth rate did not respond to environmental conditions, suggesting that the dominant microbial populations remained similar. However, warmer temperatures and increased soil moisture both reduced tlag, indicating that favorable abiotic conditions activated soil microorganisms. We conclude that soil respiratory responses to short-term changes in environmental conditions are better explained by changes in AMB than in TMB. These results suggest that decomposition models that explicitly represent microbial carbon pools should take into account the active microbial pool, and researchers should be cautious in comparing modeled microbial pool sizes with measurements of TMB. PMID:27148213

Determination of the knowledge of e-waste disposal impacts on the environment among different gender and age groups in China, Laos, and Thailand.

PubMed

Liang, Li; Sharp, Alice

2016-04-01

E-waste is the fastest growing waste in the solid waste stream in the urban environment. It has become a widely recognised social and environmental problem; therefore, proper management is vital to protecting the fragile environment from its improper disposal. Questionnaire surveys were conducted to determine the knowledge of environmental impacts of e-waste disposal as it relates to mobile phones among different gender and age groups in China, Laos, and Thailand. The results revealed that gender was positively correlated with their knowledge of the status of environmental conditions (P104) (r = 0.077, n = 1994, p < 0.01) and negatively correlated with their knowledge of how to improve environmental conditions (P105) (r = -0.067, n = 2037, p < 0.01). In addition, an increase in age was positively correlated with respondents' concern over the environmental conditions (P103) (r = 0.052, n = 2077, p < 0.05) and P105 (r = 0.061, n = 2061, p < 0.01) mentioned above. The results indicated that female respondents were less knowledgeable about how to improve environmental conditions than male respondents in the three countries. Knowledge gaps were detected in the respondents, at age ⩽17, in the three countries, and from age 18-22 to 36-45 or older from Thailand and China, on their knowledge of the existing e-waste-related laws. Thus, an effort to bridge the gaps through initiating proper educational programmes in these two countries is necessary. © The Author(s) 2016.

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

Tactical Versus Strategic Behavior: General Aviation Piloting in Convective Weather Scenarios

NASA Technical Reports Server (NTRS)

Latorella, Kara A.; Chamberlain, James P.

2002-01-01

We commonly describe environments and behavioral responses to environmental conditions as 'tactical' and 'strategic.' However theoretical research defining relevant environmental characteristics is rare, as are empirical investigations that would inform such theory. This paper discusses General Aviation (GA) pilots' descriptions of tactical/strategic conditions with respect to weather flying, and evaluates their ratings along a tactical/strategic scale in response to real convective weather scenarios experienced during a flight experiment with different weather information cues. Perceived risk was significantly associated with ratings for all experimental conditions. In addition, environmental characteristics were found to be predictive of ratings for Traditional IMC (instrument meteorological conditions), i.e., aural weather information only, and Traditional VMC (visual meteorological conditions), i.e., aural information and an external view. The paper also presents subjects' comments regarding use of Graphical Weather Information Systems (GWISs) to support tactical and strategic weather flying decisions and concludes with implications for the design and use of GWISs.

Through the eyes of children: perceptions of environmental change in tropical forests.

PubMed

Pellier, Anne-Sophie; Wells, Jessie A; Abram, Nicola K; Gaveau, David; Meijaard, Erik

2014-01-01

This study seeks to understand children's perceptions of their present and future environments in the highly biodiverse and rapidly changing landscapes of Kalimantan, Indonesian Borneo. We analyzed drawings by children (target age 10-15 years) from 22 villages, which show how children perceive the present conditions of forests and wildlife surrounding their villages and how they expect conditions to change over the next 15 years. Analyses of picture elements and their relationships to current landscape variables indicate that children have a sophisticated understanding of their environment and how different environmental factors interact, either positively or negatively. Children appear to have landscape-dependent environmental perceptions, showing awareness of past environmental conditions and many aspects of recent trends, and translating these into predictions for future environmental conditions. The further removed their present landscape is from the originally forested one, the more environmental change they expect in the future, particularly declines in forest cover, rivers, animal diversity and increases in temperature and natural disasters. This suggests that loss of past perceptions and associated "shifting environmental baselines" do not feature strongly among children on Borneo, at least not for the perceptions we investigated here. Our findings that children have negative expectations of their future environmental conditions have important political implications. More than other generations, children have a stake in ensuring that future environmental conditions support their long-term well-being. Understanding what drives environmental views among children, and how they consider trade-offs between economic development and social and environmental change, should inform optimal policies on land use. Our study illuminates part of the complex interplay between perceptions of land cover and land use change. Capturing the views of children through artistic expressions provides a potentially powerful tool to influence public and political opinions, as well as a valuable approach for developing localized education and nature conservation programs.

Through the Eyes of Children: Perceptions of Environmental Change in Tropical Forests

PubMed Central

Pellier, Anne-Sophie; Wells, Jessie A.; Abram, Nicola K.; Gaveau, David; Meijaard, Erik

2014-01-01

This study seeks to understand children's perceptions of their present and future environments in the highly biodiverse and rapidly changing landscapes of Kalimantan, Indonesian Borneo. We analyzed drawings by children (target age 10–15 years) from 22 villages, which show how children perceive the present conditions of forests and wildlife surrounding their villages and how they expect conditions to change over the next 15 years. Analyses of picture elements and their relationships to current landscape variables indicate that children have a sophisticated understanding of their environment and how different environmental factors interact, either positively or negatively. Children appear to have landscape-dependent environmental perceptions, showing awareness of past environmental conditions and many aspects of recent trends, and translating these into predictions for future environmental conditions. The further removed their present landscape is from the originally forested one, the more environmental change they expect in the future, particularly declines in forest cover, rivers, animal diversity and increases in temperature and natural disasters. This suggests that loss of past perceptions and associated “shifting environmental baselines” do not feature strongly among children on Borneo, at least not for the perceptions we investigated here. Our findings that children have negative expectations of their future environmental conditions have important political implications. More than other generations, children have a stake in ensuring that future environmental conditions support their long-term well-being. Understanding what drives environmental views among children, and how they consider trade-offs between economic development and social and environmental change, should inform optimal policies on land use. Our study illuminates part of the complex interplay between perceptions of land cover and land use change. Capturing the views of children through artistic expressions provides a potentially powerful tool to influence public and political opinions, as well as a valuable approach for developing localized education and nature conservation programs. PMID:25093658

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. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

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 impact on pre-Columbian cultures, Clim. Past Discuss., 10, 1707-1746.

Body condition of the deep water demersal resources at two adjacent oligotrophic areas of the western Mediterranean and the influence of the environmental features

NASA Astrophysics Data System (ADS)

Rueda, L.; Moranta, J.; Abelló, P.; Balbín, R.; Barberá, C.; Fernández de Puelles, M. L.; Olivar, M. P.; Ordines, F.; Ramón, M.; Torres, A. P.; Valls, M.; Massutí, E.

2014-10-01

Body condition indices not only are often used as reliable indicators of the nutritional status of individuals but also can they be utilized to provide insights regarding food availability and habitat quality. The aim of this study was to evaluate the connection between the body condition of the demersal species and the environmental features in the water column (i.e. the hydrographic conditions and the potential trophic resources) in two proximate areas, the north and south regions of the Balearic Islands (western Mediterranean), viz., the Balearic sub-basin (BsB) and the Algerian sub-basin (AsB), respectively, with different geomorphological and hydrodynamic features. Body condition indices were calculated for individuals of 21 demersal species including 11 teleosts, 4 elasmobranchs, 3 cephalopods and 3 crustaceans, which represented > 70-77% of the deep water resources, captured by bottom trawling. The morphometric indices, viz., Relative Condition Index (Kn) and Standardised Residuals (SR) from the length-weight relationship, were used. The results for each one of the 21 species indicated a significantly better condition in terms of Kn and SR in the BsB, for 7 and 9 species, respectively. In addition, a general model, including the 21 species together, showed better body condition in the BsB, and during the summer. The spatial and temporal differences in the body condition are discussed in the context of the environmental variables characterising both the study areas, which showed significant variations, for some of the hydrographic features (chlorophyll a, dissolved oxygen, salinity, potential density and temperature), as well as for some of the potential trophic resources (mesopelagic and epibenthic fauna). These findings suggest an environmental effect on the body condition of the deep-water resources in the Balearic Islands, one of the most oligotrophic areas of the western Mediterranean, and reveal more suitable environmental conditions for these species on the northern insular margin, off the Archipelago. In addition to these ecological connections, the results also hold interest for the management and conservation of the habitats essential for the sustainability of fisheries.

RNA sequencing provides evidence for functional variability between naturally co-existing Alteromonas macleodii lineages.

PubMed

Kimes, Nikole E; López-Pérez, Mario; Ausó, Eva; Ghai, Rohit; Rodriguez-Valera, Francisco

2014-10-26

Alteromonas macleodii is a ubiquitous gammaproteobacterium shown to play a biogeochemical role in marine environments. Two A. macleodii strains (AltDE and AltDE1) isolated from the same sample (i.e., the same place at the same time) show considerable genomic differences. In this study, we investigate the transcriptional response of these two strains to varying growth conditions in order to investigate differences in their ability to adapt to varying environmental parameters. RNA sequencing revealed transcriptional changes between all growth conditions examined (e.g., temperature and medium) as well as differences between the two A. macleodii strains within a given condition. The main inter-strain differences were more marked in the adaptation to grow on minimal medium with glucose and, even more so, under starvation. These differences suggested that AltDE1 may have an advantage over AltDE when glucose is the major carbon source, and co-culture experiments confirmed this advantage. Additional differences were observed between the two strains in the expression of ncRNAs and phage-related genes, as well as motility. This study shows that the genomic diversity observed in closely related strains of A. macleodii from a single environment result in different transcriptional responses to changing environmental parameters. This data provides additional support for the idea that greater diversity at the strain level of a microbial community could enhance the community's ability to adapt to environmental shifts.

The Fecal Microbial Community of Breast-fed Infants from Armenia and Georgia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Zachery T.; Sidamonidze, Ketevan; Tsaturyan, Vardan

Multiple factors help shape the infant intestinal microbiota early in life. Environmental conditions such as the presence of bioactive molecules from breast milk dictate gut microbial growth and survival. Infants also receive distinct, personalized, bacterial exposures leading to differential colonization. Microbial exposures and gut environmental conditions differ between infants in different locations, as does the typical microbial community structure in an infant’s gut. Here we evaluate potential influences on the infant gut microbiota through a longitudinal study on cohorts of breast-fed infants from the neighboring countries of Armenia and Georgia, an area of the world for which the infant microbiomemore » has not been previously investigated. Marker gene sequencing of 16S ribosomal genes revealed that the gut microbial communities of infants from these countries were dominated by bifidobacteria, were different from each other, and were marginally influenced by their mother’s secretor status. Species-level differences in the bifidobacterial communities of each country and birth method were also observed. These community differences suggest that environmental variation between individuals in different locations may influence the gut microbiota of infants.« less

The Fecal Microbial Community of Breast-fed Infants from Armenia and Georgia

PubMed Central

Lewis, Zachery T; Sidamonidze, Ketevan; Tsaturyan, Vardan; Tsereteli, David; Khachidze, Nika; Pepoyan, Astghik; Zhgenti, Ekaterine; Tevzadze, Liana; Manvelyan, Anahit; Balayan, Marine; Imnadze, Paata; Torok, Tamas; Lemay, Danielle G.; Mills, David A.

2017-01-01

Multiple factors help shape the infant intestinal microbiota early in life. Environmental conditions such as the presence of bioactive molecules from breast milk dictate gut microbial growth and survival. Infants also receive distinct, personalized, bacterial exposures leading to differential colonization. Microbial exposures and gut environmental conditions differ between infants in different locations, as does the typical microbial community structure in an infant’s gut. Here we evaluate potential influences on the infant gut microbiota through a longitudinal study on cohorts of breast-fed infants from the neighboring countries of Armenia and Georgia, an area of the world for which the infant microbiome has not been previously investigated. Marker gene sequencing of 16S ribosomal genes revealed that the gut microbial communities of infants from these countries were dominated by bifidobacteria, were different from each other, and were marginally influenced by their mother’s secretor status. Species-level differences in the bifidobacterial communities of each country and birth method were also observed. These community differences suggest that environmental variation between individuals in different locations may influence the gut microbiota of infants. PMID:28150690

The Fecal Microbial Community of Breast-fed Infants from Armenia and Georgia

DOE PAGES

Lewis, Zachery T.; Sidamonidze, Ketevan; Tsaturyan, Vardan; ...

2017-02-02

Multiple factors help shape the infant intestinal microbiota early in life. Environmental conditions such as the presence of bioactive molecules from breast milk dictate gut microbial growth and survival. Infants also receive distinct, personalized, bacterial exposures leading to differential colonization. Microbial exposures and gut environmental conditions differ between infants in different locations, as does the typical microbial community structure in an infant’s gut. Here we evaluate potential influences on the infant gut microbiota through a longitudinal study on cohorts of breast-fed infants from the neighboring countries of Armenia and Georgia, an area of the world for which the infant microbiomemore » has not been previously investigated. Marker gene sequencing of 16S ribosomal genes revealed that the gut microbial communities of infants from these countries were dominated by bifidobacteria, were different from each other, and were marginally influenced by their mother’s secretor status. Species-level differences in the bifidobacterial communities of each country and birth method were also observed. These community differences suggest that environmental variation between individuals in different locations may influence the gut microbiota of infants.« less

Environmental controls on chemoautotrophic primary producers at deep-sea vents

NASA Astrophysics Data System (ADS)

Le Bris, Nadine; Mullineaux, Lauren; Sievert, Stefan

2014-05-01

High biomasses and fast growth rates of dominant chemosynthetic species characterize hydrothermal ecosystems, raising the issue of their contribution to energy transfer and carbon cycling in the deep-sea. Addressing this issue, however, needs to account for the temporal instability of hydrothermal systems, both, in terms of biological colonization and habitat conditions. Volcanic eruptions on mid-ocean ridges offer the opportunity to investigate the environmental conditions favoring the successive modes of chemoautotrophic primary production (i.e. free living microbes and symbiotic invertebrates). In that perspective, habitat-scale approaches distinguish from vent field-scale approaches based on fluid composition and provide relevant information on environmental constraints exerted at different stages of colonization focusing on parameters linked with physiological limits and available energy. Investigation of habitat physicochemical properties along a typical successional sequence of recolonization at 9°50'N EPR diffuse-flow vents, between 2006 and 2014, was performed in order to examine potential changes in environmental features associated with chemoautotrophic primary producers, from early microbial colonizers to symbiotic invertebrates. Combined in situ measurements of temperature, pH and hydrogen sulfide were used and their variability documented over a series of assemblages characterizing recolonization stages. The distributions of mature assemblages of dominant invertebrate species associate with substantial differences in habitat conditions, pointing to a strong influence of habitat properties on potential productivity. Among the differences observed, however, the amplitude and rate of environmental fluctuation appear more important than average conditions in the succession, highlighting the role of spatial heterogeneity and temporal dynamics as a control on primary producers. Invertebrate species acting as engineer species are expected to play a primary role in the rate of organic carbon formed over the lifetime of a vent and potentially transferred to adjacent ecosystems.

Vocal Ergonomics in the Workplace: Heating, Ventilation, and Air-Conditioning Method Influences on Vocal Comfort and Function.

PubMed

Sandage, Mary J; Rahn, Keith A; Smith, Audrey G

2017-02-01

The purpose of this study was to examine the influence of the heating, ventilation, and air-conditioning method on voice function following a voicing task using ecologically valid offices, one with radiant HVAC and one with forced air. A total of 12 consented participants (6 women, 6 men) narrated a video in each of 4 environmental conditions in a within-between repeated-measures design. Acoustic data were collected with an ambulatory phonation monitor and perceived phonatory effort was determined following the voicing task. Data were analyzed using a within-between repeated-measures analysis of variance with significance set at α < .05. Perceived phonatory effort did not differ between environments; however, a significant difference in vocal amplitude between 2 trials was identified for the male participants and physiologically significant differences in vocal amplitude were identified for male and female participants. The findings suggest that perceived phonatory effort may not be a sensitive measure of vocal function differences following a voicing task in ecologically valid office spaces despite significant acoustic findings. Future research should address longer exposure to environmental differences combined with a longer voicing task within ecologically valid work spaces as well as the recruitment of participants who have particular vulnerability to environmental perturbations.

Species sorting and patch dynamics in harlequin metacommunities affect the relative importance of environment and space.

PubMed

Leibold, Mathew A; Loeuille, Nicolas

2015-12-01

Metacommunity theory indicates that variation in local community structure can be partitioned into components including those related to local environmental conditions vs. spatial effects and that these can be quantified using statistical methods based on variation partitioning. It has been hypothesized that joint associations of community composition with environment and space could be due to patch dynamics involving colonization-extinction processes in environmentally heterogeneous landscapes but this has yet to be theoretically shown. We develop a two-patch, type-two, species competition model in such a "harlequin" landscape (where different patches have different environments) to evaluate how composition is related to environmental and spatial effects as a function of background extinction rate. Using spatially implicit analytical models, we find that the environmental association of community composition declines with extinction rate as expected. Using spatially explicit simulation models, we further find that there is an increase in the spatial structure with extinction due to spatial patterning into clusters that are not related to environmental conditions but that this increase is limited. Natural metacommunities often show both environment and spatial determination even under conditions of relatively high isolation and these could be more easily explained by our model than alternative metacommunity models.

A study on task difficulty and acceleration stress

NASA Technical Reports Server (NTRS)

Repperger, D. W.; Rogers, D. B.

1981-01-01

The results of two experiments which relate to task difficulty and the effects of environmental stress on tracking performance are discussed and compared to subjective evaluations. The first experiment involved five different sum of sine tracking tasks which humans tracked both in a static condition and under a 5 Gz acceleration stress condition. The second experiment involved similar environmental stress conditions but in this case the tasks were constructed from deterministic functions with specially designed velocity and acceleration profiles. Phase Plane performance analysis was conducted to study potential measures of workload or tracking difficulty.

Anaerobic biodegradation of (emerging) organic contaminants in the aquatic environment.

PubMed

Ghattas, Ann-Kathrin; Fischer, Ferdinand; Wick, Arne; Ternes, Thomas A

2017-06-01

Although strictly anaerobic conditions prevail in several environmental compartments, up to now, biodegradation studies with emerging organic contaminants (EOCs), such as pharmaceuticals and personal care products, have mainly focused on aerobic conditions. One of the reasons probably is the assumption that the aerobic degradation is more energetically favorable than degradation under strictly anaerobic conditions. Certain aerobically recalcitrant contaminants, however, are biodegraded under strictly anaerobic conditions and little is known about the organisms and enzymatic processes involved in their degradation. This review provides a comprehensive survey of characteristic anaerobic biotransformation reactions for a variety of well-studied, structurally rather simple contaminants (SMOCs) bearing one or a few different functional groups/structural moieties. Furthermore it summarizes anaerobic degradation studies of more complex contaminants with several functional groups (CMCs), in soil, sediment and wastewater treatment. While strictly anaerobic conditions are able to promote the transformation of several aerobically persistent contaminants, the variety of observed reactions is limited, with reductive dehalogenations and the cleavage of ether bonds being the most prevalent. Thus, it becomes clear that the transferability of degradation mechanisms deduced from culture studies of SMOCs to predict the degradation of CMCs, such as EOCs, in environmental matrices is hampered due the more complex chemical structure bearing different functional groups, different environmental conditions (e.g. matrix, redox, pH), the microbial community (e.g. adaptation, competition) and the low concentrations typical for EOCs. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Characterization of iron and manganese minerals and their associated microbiota in different mine sites to reveal the potential interactions of microbiota with mineral formation.

PubMed

Park, Jin Hee; Kim, Bong-Soo; Chon, Chul-Min

2018-01-01

Different environmental conditions such as pH and dissolved elements of mine stream induce precipitation of different minerals and their associated microbial community may vary. Therefore, mine precipitates from various environmental conditions were collected and their associated microbiota were analyzed through metagenomic DNA sequencing. Various Fe and Mn minerals including ferrihydrite, schwertmannite, goethite, birnessite, and Mn-substituted δ-FeOOH (δ-(Fe 1-x , Mn x )OOH) were found in the different environmental conditions. The Fe and Mn minerals were enriched with toxic metal(loid)s including As, Cd, Ni and Zn, indicating they can act as scavengers of toxic metal(loid)s in mine streams. Under acidic conditions, Acidobacteria was dominant phylum and Gallionella (Fe oxidizing bacteria) was the predominant genus in these Fe rich environments. Manganese oxidizing bacteria, Hyphomicrobium, was found in birnessite forming environments. Leptolyngbya within Cyanobacteria was found in Fe and Mn oxidizing environments, and might contribute to Fe and Mn oxidation through the production of molecular oxygen. The potential interaction of microbial community with minerals in mine sites can be traced by analysis of microbial community in different Fe and Mn mineral forming environments. Iron and Mn minerals contribute to the removal of toxic metal(loid)s from mine water. Therefore, the understanding characteristics of mine precipitates and their associated microbes helps to develop strategies for the management of contaminated mine water. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fitness Effects of Chlorpyrifos in the Damselfly Enallagma cyathigerum Strongly Depend upon Temperature and Food Level and Can Bridge Metamorphosis

PubMed Central

Janssens, Lizanne; Stoks, Robby

2013-01-01

Interactions between pollutants and suboptimal environmental conditions can have severe consequences for the toxicity of pollutants, yet are still poorly understood. To identify patterns across environmental conditions and across fitness-related variables we exposed Enallagma cyathigerum damselfly larvae to the pesticide chlorpyrifos at two food levels or at two temperatures and quantified four fitness-related variables (larval survival, development time, mass at emergence and adult cold resistance). Food level and temperature did not affect survival in the absence of the pesticide, yet the pesticide reduced survival only at the high temperature. Animals reacted to the pesticide by accelerating their development but only at the high food level and at the low temperature; at the low food level, however, pesticide exposure resulted in a slower development. Chlorpyrifos exposure resulted in smaller adults except in animals reared at the high food level. Animals reared at the low food level and at the low temperature had a higher cold resistance which was not affected by the pesticide. In summary our study highlight that combined effects of exposure to chlorpyrifos and the two environmental conditions (i) were mostly interactive and sometimes even reversed in comparison with the effect of the environmental condition in isolation, (ii) strongly differed depending on the fitness-related variable under study, (iii) were not always predictable based on the effect of the environmental condition in isolation, and (iv) bridged metamorphosis depending on which environmental condition was combined with the pesticide thereby potentially carrying over from aquatic to terrestrial ecosystems. These findings are relevant when extrapolating results of laboratory tests done under ideal environmental conditions to natural communities. PMID:23840819

Effect of odour on multisensory environmental evaluations of road traffic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Like, E-mail: jianglike@yahoo.com; Masullo, Massimiliano, E-mail: Massimiliano.MASULLO@unina2.it; Maffei, Luigi, E-mail: luigi.maffei@unina2.it

This study investigated the effect of odour on multisensory environmental evaluations of road traffic. The study aimed to answer: (1) Does odour have any effect on evaluations on noise, landscape and the overall environment? (2) How different are participants' responses to odour stimuli and are these differences influential on the evaluations? Experimental scenarios varied in three Traffic levels, three Tree screening conditions and two Odour presence conditions were designed, and presented to participants in virtual reality. Perceived Loudness, Noise Annoyance, Landscape Quality and Overall Pleasantness of each scenario were evaluated and the results were analysed. It shows that Odour presencemore » did not have significant main effect on any of the evaluations, but has significant interactions with Traffic level on Noise Annoyance and with Tree screening on Landscape Quality, indicating the potential of odour to modulate noise and visual landscape perceptions in specific environmental content. Concerning participants' responses to odour stimuli, large differences were found in this study. However, the differences did not seem to be influential on environmental evaluations in this study. Larger samples of participants may benefit this study for more significant results of odour effect.« less

Bone microstructure and developmental plasticity in birds and other dinosaurs.

PubMed

Starck, J Matthias; Chinsamy, Anusuya

2002-12-01

Patterns of bone microstructure have frequently been used to deduce dynamics and processes of growth in extant and fossil tetrapods. Often, the various types of primary bone tissue have been associated with different bone deposition rates and more recently such deductions have extended to patterns observed in dinosaur bone microstructure. These previous studies are challenged by the findings of the current research, which integrates an experimental neontological approach and a paleontological comparison. We use tetracycline labeling and morphometry to study the variability of bone deposition rates in Japanese quail (Coturnix japonica) growing under different experimental conditions. We compare resulting patterns in bone microstructure with those found in fossil birds and other dinosaurs. We found that a single type of primary bone varies significantly in rates of growth in response to environmental conditions. Ranging between 10-50 microm per day, rates of growth overlap with the full range of bone deposition rates that were previously associated with different patterns of bone histology. Bone formation rate was significantly affected by environmental/experimental conditions, skeletal element, and age. In the quail, the experimental conditions did not result in formation of lines of arrested growth (LAGs). Because of the observed variation of bone deposition rates in response to variation in environmental conditions, we conclude that bone deposition rates measured in extant birds cannot simply be extrapolated to their fossil relatives. Additionally, we observe the variable incidence of LAGs and annuli among several dinosaur species, including fossil birds, extant sauropsids, as well as nonmammalian synapsids, and some extant mammals. This suggests that the ancestral condition of the response of bone to environmental conditions was variable. We propose that such developmental plasticity in modern birds may be reduced in association with the shortened developmental time during the later evolution of the ornithurine birds. Copyright 2002 Wiley-Liss, Inc.

Effects of environmental conditions on the ultrafast carrier dynamics in graphene revealed by terahertz spectroscopy

NASA Astrophysics Data System (ADS)

Hafez, H. A.; Chai, X.; Sekine, Y.; Takamura, M.; Oguri, K.; Al-Naib, I.; Dignam, M. M.; Hibino, H.; Ozaki, T.

2017-04-01

A thorough understanding of the stability of graphene under ambient environmental conditions is essential for future graphene-based applications. In this paper, we study the effects of ambient temperature on the properties of monolayer graphene using terahertz time-domain spectroscopy as well as time-resolved terahertz spectroscopy enabled by an optical-pump/terahertz-probe technique. The observations show that graphene is extremely sensitive to the ambient environmental conditions and behaves differently depending on the sample preparation technique and the initial Fermi level. The analysis of the spectroscopic data is supported by van der Pauw and Hall effect measurements of the carrier mobility and carrier density at temperatures comparable to those tested in our THz spectroscopic experiments.

Biological characteristics of geographically isolated populations of Meccus mazzottii (Hemiptera: Reduviidae) in southern Mexico.

PubMed

Martínez-Ibarra, J A; Nogueda-Torres, B; Vargas-Llamas, V; García-Benavides, G; Bustos-Saldaña, R; Villagrán, M E; de Diego-Cabrera, J A; Tapia-González, J M

2014-01-01

Chagas disease, caused by Trypanosoma cruzi Chagas, is one of the most epidemiologically important vector-borne zoonoses in Mexico. Among the 32 reported triatomine species from Mexico, Meccus mazzottii (Usinger) (Hemiptera: Reduviidae) is one of the most important vectors of T. cruzi in the southern part of the country. Variability among populations of triatomines has been recorded for several species (Meccus longipennis (Usinger) and Meccus pallidipennis (Stal)) that are closely related to M. mazzottii, showing an apparent influence of local environmental conditions on the biology of each population, which could modify the impact of vector control measurements. Therefore, this study sought to compare the biological features of populations of M. mazzottii from two geographically far apart areas that have similar environmental characteristics and to compare populations from close geographical areas that have different environmental characteristics. The mean longevity, percentages of mortality of nymphs, the total mean number of bloodmeals to molt (considered instar by instar), the mean number of eggs laid by females, and the percentage of hatched eggs were similar between the two localities that are geographically far apart but have similar environmental characteristics. On the other hand, important differences were noticed when a comparison was carried out on the two localities with similar environmental conditions with respect to that locality with different conditions, independent of geographic distance. Most of the studied parameters led us to conclude that the three studied populations are very highly influenced by local environmental conditions. The results of this study indicate the importance of studying the biological characteristics of local populations of triatomines to carry out specific control measurements, instead of using standard ones that could fail if they are not adapted to the target population. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

Hydro-edaphic conditions defining richness and species composition in savanna areas of the northern Brazilian Amazonia

PubMed Central

Araújo, Maria Aparecida de Moura; da Rocha, Antônio Elielson Sousa; Miranda, Izildinha de Souza

2017-01-01

Abstract Background Studies on plant communities in the Amazon have reported that different hydro-edaphic conditions can affect the richness and the species composition of different ecosystems. However, this aspect is poorly known in the different savanna habitats. Understanding how populations and plant communities are distributed in these open vegetation areas is important to improve the knowledge about which environmental variables influence the occurrence and diversity of plants in this type of regional ecosystem. Thus, this study investigated the richness and composition of plant species in two savanna areas of the northern Brazilian Amazonia, using the coverage (%) of the different life forms observed under different hydro-edaphic conditions as a structural reference. New information We report 128 plant species classified in 34 botanical families distributed in three savanna habitats with different levels of hydro-edaphic restrictions. In this study, the habitats are conceptually presented and they integrate environmental information (edaphic factors and drainage type), which determines differences between floristic composition, species richness and coverage (%) of plant life forms. PMID:28848372

Provenance effect on carbon assimilation, photochemistry and leaf morphology in Mediterranean Cistus species under chilling stress.

PubMed

Puglielli, G; Cuevas Román, F J; Catoni, R; Moreno Rojas, J M; Gratani, L; Varone, L

2017-07-01

The potential resilience of shrub species to environmental change deserves attention in those areas threatened by climate change, such as the Mediterranean Basin. We asked if leaves produced under different climate conditions through the winter season to spring can highlight the leaf traits involved in determining potential resilience of three Cistus spp. to changing environmental conditions and to what extent intraspecific differences affect such a response. We analysed carbon assimilation, maximum quantum efficiency of PSII photochemistry (F v /F m ) and leaf morphological control of the photosynthetic process in leaves formed through the winter season into spring in C. creticus subsp. eriocephalus (CE), C. salvifolius (CS) and C. monspeliensis (CM) grown from seed of different provenances under common garden conditions. Intraspecific differences were found in F v /F m for CE and CS. Carbon assimilation-related parameters were not affected by provenance. Moreover, our analysis highlighted that the functional relationships investigated can follow seasonal changes and revealed patterns originating from species-specific differences in LMA arising during the favourable period. Cistus spp. have great ability to modify the structure and function of their leaves in the mid-term in order to cope with changing environmental conditions. The F v /F m response to chilling reveals that susceptibility to photoinhibition is a trait under selection in Cistus species. Concerning carbon assimilation, differing ability to control stomatal opening was highlighted between species. Moreover, seasonal changes of the functional relationships investigated can have predictable consequences on species leaf turnover strategies. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

Comparison of gait performance on different environmental settings for patients with chronic spinal cord injury.

PubMed

Olmos, L E; Freixes, O; Gatti, M A; Cozzo, D A; Fernandez, S A; Vila, C J; Agrati, P E; Rubel, I F

2008-05-01

Observational cross-section study. The objective of our study was to determine if the influence of a community environment would impact on ASIA D spinal cord injured (SCI) gait performance patients. Our main hypothesis is that an outdoor community environment may influence gait speed and endurance on community ambulating patients. Ten-Meter Walking (10MWT) and Six-Minute Walking (6MWT) tests were performed on community ambulating SCI research participants (n=18) in two different environmental conditions: (1) Experimental (indoors Gymnasium) and (2) Natural (community setting). Average gait speed and endurance values were obtained for the two different conditions and analyzed for statistical significance on the nonparametric two-tailed Wilcoxon signed rank test. While no difference was observed on the 10MWT we found an improvement on gait performance on the 6 MWT on a community setting. Our study showed mixed results on environmental influence on gait speed and endurance on ASIA D patient population. While there is no difference on the 10 MWT, there is an improvement on gait performance on the communitary 6MWT.

Environmental and habitat drivers of relative abundance for a suite of azteca-attacking Pseudacteon phorid flies.

PubMed

Reese, Katlynd M; Philpott, Stacy M

2012-10-01

Phoridae (Diptera) have widespread impacts on insect communities by limiting host ant behavior. However, phorid-ant interactions may vary with habitat or environmental conditions. Three Pseudacteon species parasitize Azteca instabilis Fr. Smith, a common ant in coffee agroecosystems, and limit A. instabilis foraging, indirectly benefiting other insects. However, little is known about how phorid abundance, behavior, and effects change with environmental conditions. In shaded coffee systems, coffee (Coffea arabica L.) grows under a range of shade conditions and management changes affect species interactions. For example, Pseudacteon spp. more strongly limit A. instabilis foraging in low-shade coffee habitats. We sampled relative abundance of three phorid species around A. instabilis nests in three coffee habitats varying in shade management during dry and wet seasons. We measured canopy cover, tree richness, tree density, leaf litter depth, and number of nearby trees with A. instabilis to determine whether these habitat factors correlate with phorid abundance. P. laciniosus Brown was the most abundant phorid in both seasons. Phorid relative abundance did not differ by habitat, but did differ by season. P. laciniosus accounted for a higher proportion of phorids in the wet season (91.4%) than in the dry season (78.9%), and P. planidorsalis Brown accounted for a larger percent in the dry season (21.1%) than in the wet season (7.3%). Phorid composition did not differ with habitat type, and none of the measured environmental variables correlated with changes in phorid composition. Thus, phorids in coffee agroecosystems respond to large seasonal differences, but not differences between coffee habitats.

Relations between water physico-chemistry and benthic algal communities in a northern Canadian watershed: defining reference conditions using multiple descriptors of community structure.

PubMed

Thomas, Kathryn E; Hall, Roland I; Scrimgeour, Garry J

2015-09-01

Defining reference conditions is central to identifying environmental effects of anthropogenic activities. Using a watershed approach, we quantified reference conditions for benthic algal communities and their relations to physico-chemical conditions in rivers in the South Nahanni River watershed, NWT, Canada, in 2008 and 2009. We also compared the ability of three descriptors that vary in terms of analytical costs to define algal community structure based on relative abundances of (i) all algal taxa, (ii) only diatom taxa, and (iii) photosynthetic pigments. Ordination analyses showed that variance in algal community structure was strongly related to gradients in environmental variables describing water physico-chemistry, stream habitats, and sub-watershed structure. Water physico-chemistry and local watershed-scale descriptors differed significantly between algal communities from sites in the Selwyn Mountain ecoregion compared to sites in the Nahanni-Hyland ecoregions. Distinct differences in algal community types between ecoregions were apparent irrespective of whether algal community structure was defined using all algal taxa, diatom taxa, or photosynthetic pigments. Two algal community types were highly predictable using environmental variables, a core consideration in the development of Reference Condition Approach (RCA) models. These results suggest that assessments of environmental impacts could be completed using RCA models for each ecoregion. We suggest that use of algal pigments, a high through-put analysis, is a promising alternative compared to more labor-intensive and costly taxonomic approaches for defining algal community structure.

Spatio-temporal patterns and environmental controls of small pelagic fish body condition from contrasted Mediterranean areas

NASA Astrophysics Data System (ADS)

Brosset, Pablo; Fromentin, Jean-Marc; Van Beveren, Elisabeth; Lloret, Josep; Marques, Virginie; Basilone, Gualtiero; Bonanno, Angelo; Carpi, Piera; Donato, Fortunata; Čikeš Keč, Vanja; De Felice, Andrea; Ferreri, Rosalia; Gašparević, Denis; Giráldez, Ana; Gücü, Ali; Iglesias, Magdalena; Leonori, Iole; Palomera, Isabel; Somarakis, Stylianos; Tičina, Vjekoslav; Torres, Pedro; Ventero, Ana; Zorica, Barbara; Ménard, Frédéric; Saraux, Claire

2017-02-01

Small pelagic fish are among the most ecologically and economically important marine fish species and are characterized by large fluctuations all over the world. In the Mediterranean Sea, low catches and biomass of anchovies and sardines have been described in some areas during the last decade, resulting in important fisheries crises. Therefore, we studied anchovy and sardine body condition variability, a key index of population health and its response to environmental and anthropogenic changes. Wide temporal and spatial patterns were investigated by analyzing separately data from scientific surveys and fisheries in eight Mediterranean areas between 1975 and 2015. Results showed that anchovy and sardine body condition as well as maximum size in some areas sharply decreased in most Mediterranean areas along years (except in the Northern Alboran Sea). Despite this general pattern, well-marked environmental differences between sub-regions were highlighted by several analyses and variations in body condition were not found to be homogeneous over all the Mediterranean Sea. Further, other analyses revealed that except for the Adriatic where major changes towards a lower body condition were concomitant with a decrease in river runoffs and chl-a concentration, no concomitant environmental regime shift was detected in other areas. Together, these analyses highlighted the current poor body condition of almost all small pelagic fish populations in the Mediterranean. Yet, global environmental indices could not explain the observed changes and the general decrease in condition might more likely come from regional environmental and/or anthropogenic (fishing) effects. A prolonged state of poor fish body condition, together with an observed reduced size and early age-at-maturity may have strong ecological, economic and social consequences all around the Mediterranean Sea.

Avian predator buffers against variability in marine habitats with flexible foraging behavior

USGS Publications Warehouse

Schoen, Sarah K.; Piatt, John F.; Arimitsu, Mayumi L.; Heflin, Brielle; Madison, Erica N.; Drew, Gary S.; Renner, Martin; Rojek, Nora A.; Douglas, David C.; DeGange, Anthony R.

2018-01-01

How well seabirds compensate for variability in prey abundance and composition near their breeding colonies influences their distribution and reproductive success. We used tufted puffins (Fratercula cirrhata) as forage fish samplers to study marine food webs from the western Aleutian Islands (53°N, 173°E) to Kodiak Island (57°N, 153°W), Alaska, during August 2012–2014. Around each colony we obtained data on: environmental characteristics (sea surface temperature and salinity, seafloor depth and slope, tidal range, and chlorophyll-a), relative forage fish biomass (hydroacoustic backscatter), and seabird community composition and density at-sea. On colonies, we collected puffin chick-meals to characterize forage communities and determine meal energy density, and measured chicks to obtain a body condition index. There were distinct environmental gradients from west to east, and environmental variables differed by ecoregions: the (1) Western-Central Aleutians, (2) Eastern Aleutians, and, (3) Alaska Peninsula. Forage fish biomass, species richness, and community composition all differed markedly between ecoregions. Forage biomass was strongly correlated with environmental gradients, and environmental gradients and forage biomass accounted for ~ 50% of the variability in at-sea density of tufted puffins and all seabird taxa combined. Despite the local and regional variability in marine environments and forage, the mean biomass of prey delivered to puffin chicks did not differ significantly between ecoregions, nor did chick condition or puffin density at-sea. We conclude that puffins can adjust their foraging behavior to produce healthy chicks across a wide range of environmental conditions. This extraordinary flexibility enables their overall success and wide distribution across the North Pacific Ocean.

Managing Dive Tourism for the Sustainable Use of Coral Reefs: Validating Diver Perceptions of Attractive Site Features

NASA Astrophysics Data System (ADS)

Uyarra, Maria C.; Watkinson, Andrew R.; Côté, Isabelle M.

2009-01-01

It has been argued that strategies to manage natural areas important for tourism and recreation should integrate an understanding of tourist preferences for specific natural features. However, the accuracy of tourist recalled perceptions of environmental attributes, which are usually derived from post hoc surveys and used to establish management priorities, is currently unmeasured. We tested the validity of the relationship between tourist-stated preferences and actual condition of coral reefs around the Caribbean island of Bonaire. Using standardized questionnaires, we asked 200 divers to select their most and least favorite dive sites and the attributes that contributed to that selection. We also carried out ecological surveys at 76 of the 81 dives sites around the island to assess the actual conditions of the attributes indicated as important for site selection. Fish- and coral-related attributes were key features affecting dive enjoyment. In general, divers appeared to be able to perceive differences between sites in the true condition of biological attributes such as fish species richness, total number of fish schools, live coral cover, coral species richness, and reef structural complexity, although men and women divers differed in their ability to perceive/recall some of the attributes. Perceived differences in environmental attributes, such as surface conditions, underwater current, and the likelihood of encountering rare fish and sea turtles, were not empirically validated. The fact that divers perceive correctly differences in the condition of some of the key biological attributes that affect dive enjoyment reinforces the need to maintain overall reef condition at satisfactory levels. However, variation in accuracy of perceptions owing to demographic factors and attribute type suggests the need for caution when using public perceptions to develop environmental management strategies, particularly for coral reefs.

Managing dive tourism for the sustainable use of coral reefs: validating diver perceptions of attractive site features.

PubMed

Uyarra, Maria C; Watkinson, Andrew R; Côté, Isabelle M

2009-01-01

It has been argued that strategies to manage natural areas important for tourism and recreation should integrate an understanding of tourist preferences for specific natural features. However, the accuracy of tourist recalled perceptions of environmental attributes, which are usually derived from post hoc surveys and used to establish management priorities, is currently unmeasured. We tested the validity of the relationship between tourist-stated preferences and actual condition of coral reefs around the Caribbean island of Bonaire. Using standardized questionnaires, we asked 200 divers to select their most and least favorite dive sites and the attributes that contributed to that selection. We also carried out ecological surveys at 76 of the 81 dives sites around the island to assess the actual conditions of the attributes indicated as important for site selection. Fish- and coral-related attributes were key features affecting dive enjoyment. In general, divers appeared to be able to perceive differences between sites in the true condition of biological attributes such as fish species richness, total number of fish schools, live coral cover, coral species richness, and reef structural complexity, although men and women divers differed in their ability to perceive/recall some of the attributes. Perceived differences in environmental attributes, such as surface conditions, underwater current, and the likelihood of encountering rare fish and sea turtles, were not empirically validated. The fact that divers perceive correctly differences in the condition of some of the key biological attributes that affect dive enjoyment reinforces the need to maintain overall reef condition at satisfactory levels. However, variation in accuracy of perceptions owing to demographic factors and attribute type suggests the need for caution when using public perceptions to develop environmental management strategies, particularly for coral reefs.

In search of greener pastures: Using satellite images to predict the effects of environmental change on zebra migration

NASA Astrophysics Data System (ADS)

Bartlam-Brooks, Hattie L. A.; Beck, Pieter S. A.; Bohrer, Gil; Harris, Stephen

2013-12-01

ungulate migrations occurred in most grassland and boreal woodland ecosystems, but many have been lost due to increasing habitat loss and fragmentation. With the rate of environmental change increasing, identifying and prioritizing migration routes for conservation has taken on a new urgency. Understanding the cues that drive long-distance animal movements is critical to predicting the fate of migrations under different environmental change scenarios and how large migratory herbivores will respond to increasing resource heterogeneity and anthropogenic influences. We used an individual-based modeling approach to investigate the influence of environmental conditions, monitored using satellite data, on departure date and movement speed of migrating zebras in Botswana. Daily zebra movements between dry and rainy season ranges were annotated with coincident observations of precipitation from the Tropical Rainfall Measuring Mission data set and Moderate Resolution Imaging Spectroradiometer-derived normalized difference vegetation index (NDVI). An array of increasingly complex movement models representing alternative hypotheses regarding the environmental cues and controls for movement was parameterized and tested. The best and most justified model predicted daily zebra movement as two linear functions of precipitation rate and NDVI and included a modeled departure date as a function of cumulative precipitation. The model was highly successful at replicating both the timing and pace of seven actual migrations observed using GPS telemetry (R2 = 0.914). It shows how zebras rapidly adjust their movement to changing environmental conditions during migration and are able to reverse migration to avoid adverse conditions or exploit renewed resource availability, a nomadic behavior which should lend them a degree of resilience to climate and environmental change. Our results demonstrate how competing individual-based migration models, informed by freely available satellite data, can be used to evaluate the weight of evidence for multiple hypotheses regarding the use of environmental cues in animal movement. This modeling framework can be applied to quantify how animals adapt the timing and pace of their movements to prevailing environmental conditions and to forecast migrations in near real time or under alternative environmental scenarios.

A Causal Relationship of Occupational Stress among University Employees

PubMed Central

KAEWANUCHIT, Chonticha; MUNTANER, Carles; ISHA, Nizam

2015-01-01

Background: Occupational stress is a psychosocial dimension of occupational health concept on social determinants of health, especially, job & environmental condition. Recently, staff network of different government universities of Thailand have called higher education commission, and Ministry of Education, Thailand to resolve the issue of government education policy (e.g. wage inequity, poor welfare, law, and job & environment condition) that leads to their job insecurity, physical and mental health problems from occupational stress. The aim of this study was to investigate a causal relationship of occupational stress among the academic university employees. Methods: This cross sectional research was conducted in 2014 among 2,000 academic university employees at Thai government universities using stratified random sampling. Independent variables were wage, family support, periods of duty, and job & environmental condition. Dependent variable was stress. Results: Job & environmental condition, as social and environmental factor, and periods of duty as individual factor had direct effect to stress (P< 0.05). Family support, as family factor, and wage, as individual factor had direct effect to stress (P < 0.05). Both family support and wage were the causal endogenous variables. Conclusion: Job & environmental condition and periods of duty were increased so that it associated with occupational stress among academic university employees at moderate level. PMID:26576371

Development of a Direct Headspace Collection Method from Arabidopsis Seedlings Using HS-SPME-GC-TOF-MS Analysis

PubMed Central

Kusano, Miyako; Iizuka, Yumiko; Kobayashi, Makoto; Fukushima, Atsushi; Saito, Kazuki

2013-01-01

Plants produce various volatile organic compounds (VOCs), which are thought to be a crucial factor in their interactions with harmful insects, plants and animals. Composition of VOCs may differ when plants are grown under different nutrient conditions, i.e., macronutrient-deficient conditions. However, in plants, relationships between macronutrient assimilation and VOC composition remain unclear. In order to identify the kinds of VOCs that can be emitted when plants are grown under various environmental conditions, we established a conventional method for VOC profiling in Arabidopsis thaliana (Arabidopsis) involving headspace-solid-phase microextraction-gas chromatography-time-of-flight-mass spectrometry (HS-SPME-GC-TOF-MS). We grew Arabidopsis seedlings in an HS vial to directly perform HS analysis. To maximize the analytical performance of VOCs, we optimized the extraction method and the analytical conditions of HP-SPME-GC-TOF-MS. Using the optimized method, we conducted VOC profiling of Arabidopsis seedlings, which were grown under two different nutrition conditions, nutrition-rich and nutrition-deficient conditions. The VOC profiles clearly showed a distinct pattern with respect to each condition. This study suggests that HS-SPME-GC-TOF-MS analysis has immense potential to detect changes in the levels of VOCs in not only Arabidopsis, but other plants grown under various environmental conditions. PMID:24957989

Estimating switchgrass productivity in the Great Plains using satellite vegetation index and site environmental variables

USGS Publications Warehouse

Gu, Yingxin; Wylie, Bruce K.; Howard, Daniel M.

2015-01-01

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 develop a data-driven multiple regression switchgrass productivity model and identify the optimal climate and environment conditions for the highly productive switchgrass in the Great Plains (GP). Environmental and climate variables used in the study include elevation, soil organic carbon, available water capacity, climate, and seasonal weather. Satellite-derived growing season averaged Normalized Difference Vegetation Index (GSN) was used as a proxy for switchgrass productivity. Multiple regression analyses indicate that there are strong correlations between site environmental variables and switchgrass productivity (r = 0.95). Sufficient precipitation and suitable temperature during the growing season (i.e., not too hot or too cold) are favorable for switchgrass growth. Elevation and soil characteristics (e.g., soil available water capacity) are also an important factor impacting switchgrass productivity. An anticipated switchgrass biomass productivity map for the entire GP based on site environmental and climate conditions and switchgrass productivity model was generated. Highly productive switchgrass areas are mainly located in the eastern part of the GP. Results from this study can help land managers and biofuel plant investors better understand the general environmental and climate conditions influencing switchgrass growth and make optimal land use decisions regarding switchgrass development in the GP.

Dynamic regulation of partner abundance mediates response of reef coral symbioses to environmental change.

PubMed

Cunning, R; Vaughan, N; Gillette, P; Capo, T R; Matté, J L; Baker, A C

2015-05-01

Regulating partner abunclance may allow symmotic organisms to mediate interaction outcomes, facilitating adaptive responses to environmental change. To explore the capacity for-adaptive regulation in an ecologically important endosymbiosis, we studied the population dynamics of symbiotic algae in reef-building corals under different abiotic contexts. We found high natural variability in symbiont abundance in corals across reefs, but this variability converged to different symbiont-specific abundances when colonies were maintained under constant conditions. When conditions changed seasonally, symbiont abundance readjusted to new equilibria. We explain these patterns using an a priori model of symbiotic costs and benefits to the coral host, which shows that the observed changes in symbiont abundance are consistent with the maximization of interaction benefit under different environmental conditions. These results indicate that, while regulating symbiont abundance helps hosts sustain maximum benefit in a dynamic environment, spatiotemporal variation in abiotic factors creates a broad range of symbiont abundances (and interaction outcomes) among corals that may account for observed natural variability in performance (e.g., growth rate) and stress tolerance (e.g., bleaching susceptibility). This cost or benefit framework provides a new perspective on the dynamic regulation of reef coral symbioses and illustrates that the dependence of interaction outcomes on biotic and abiotic contexts may be important in understanding how diverse mutualisms respond to environmental change.

Replicating the Conditions on Mars: the Possibility of Sustaining Life

NASA Astrophysics Data System (ADS)

Abdul-Masih, Michael; Guinan, E. F.

2013-01-01

We describe a laboratory experiment that replicates environmental conditions on Mars’s surface to determine the viability of Earth-based life under conditions on Mars. Of all the organisms currently known, the ones that are best suited for the harsh environments found throughout our solar system are the extremophiles found on Earth that tolerate extreme environmental conditions. The environmental conditions on Mars are the least extreme of all the planets in our solar system excluding Earth. The average temperature near the equator varies from +10 C to -20 C and the surface pressure is P ~ 0.01 Atm. The thin atmosphere means that the UV radiation from the Sun is relatively unshielded. Carbon Dioxide (CO2) makes up approximately 95% of Mars’ atmosphere and the soil is composed primarily of iron oxides. This being said, water can exist in liquid form under the surface and because of this, so can life. To test this, we constructed an air-tight chamber out of Plexiglas that replicates the environmental conditions on Mars. As a first step, two different organisms were tested for survival: E-coli, which was the control, and Hypsibius (Tardigrades), a member of the Tardigradas phylum. We hypothesized that the E-coli would perish while the more hardy Tardigrades would survive. The trials were two days each and the chosen temperature was ~4°C. Many trials were conducted. After the first compilation of the results, the hypothesis did not hold. The E-coli surprisingly survived while the Tardigrades did not survive. The E-coli did not grow while in the chamber, but after being removed they grew showing that they were still viable and that the conditions were not harsh enough to kill them. After these initial results, the experiment was altered slightly to ensure that the Tardigrades were able to successfully enter their hibernation like state that allows them to survive extreme conditions. These experiments are continuing and we will discuss the results under controlled differing environmental conditions. This research is supported by a grant from Villanova University Center for Undergraduate Research and Fellowships & also supported by NSF/RUI Grant AST-1009903.

Untangling elevation-related differences in the hippocampus in food-caching mountain chickadees: the effect of a uniform captive environment.

PubMed

Freas, C A; Bingman, K; Ladage, L D; Pravosudov, V V

2013-01-01

Variation in environmental conditions associated with differential selection on spatial memory has been hypothesized to result in evolutionary changes in the morphology of the hippocampus, a brain region involved in spatial memory. At the same time, it is well known that the morphology of the hippocampus might also be directly affected by environmental conditions. Understanding the role of environment-based plasticity is therefore critical when investigating potential adaptive evolutionary changes in the hippocampus associated with environmental variation. We previously demonstrated large elevation-related variation in hippocampus morphology in mountain chickadees over an extremely small spatial scale. We hypothesized that this variation is related to differential selection pressures associated with differences in winter climate severity along an elevation gradient, which make different demands on spatial memory used for food cache retrieval. Here, we tested whether such variation is experience based, generated by potential differences in the environment, by comparing the hippocampus morphology of chickadees from different elevations maintained in a uniform captive environment in a laboratory with those sampled directly from the wild. In addition, we compared hippocampal neuron soma size in chickadees sampled directly from the wild with those maintained in laboratory conditions with restricted and unrestricted spatial memory use via manipulation of food-caching experiences to test whether memory use can affect neuron soma size. There were significant elevation-related differences in hippocampus volume and the total number of hippocampal neurons, but not in neuron soma size, in captive birds. Captive environmental conditions were associated with a large reduction in hippocampus volume and neuron soma size, but not in the total number of neurons or in neuron soma size in other telencephalic regions. Restriction of memory use while in laboratory conditions produced no significant effects on hippocampal neuron soma size. Overall our results showed that captivity has a strong effect on hippocampus volume, which could be due, at least partly, to a reduction in neuron soma size specifically in the hippocampus, but it did not override elevation-related differences in hippocampus volume or in the total number of hippocampal neurons. These data are consistent with the idea of the adaptive nature of the elevation-related differences associated with selection on spatial memory, while at the same time demonstrating additional environment-based plasticity in hippocampus volume, but not in neuron numbers. Our results, however, cannot rule out that the differences between elevations might still be driven by some developmental or early posthatching conditions/experiences. © 2013 S. Karger AG, Basel.

Relationship between δ 18O values for skeletal apatite from reindeer and foxes and yearly mean δ 18O values of environmental water

NASA Astrophysics Data System (ADS)

Iacumin, Paola; Longinelli, Antonio

2002-07-01

The oxygen isotope composition of bone and tooth phosphate of 50 fox specimens and 30 reindeer specimens from various locations with different climatic and environmental conditions was measured. The existing relationship between these values and the mean oxygen isotope composition of local meteoric water has been calculated. In the case of foxes, specimens belonging to two genera ( Vulpes and Alopex) and three different species were measured. The samples fit a straight line whose equation can be used for paleoclimatological studies either in Arctic or in temperate regions. For reindeer ( Rangifer), a relatively large range of isotopic values was obtained from each location, suggesting imperfect equilibrium conditions with environmental water. The calculated equation can be used for semi-quantitative information on local paleowaters at high latitudes only.

Effects of changing environmental conditions on synthetic aperture radar backscattering coefficient, scattering mechanisms, and class separability in a forest area

NASA Astrophysics Data System (ADS)

Mahdavi, Sahel; Maghsoudi, Yasser; Amani, Meisam

2017-07-01

Environmental conditions have considerable effects on synthetic aperture radar (SAR) imagery. Therefore, assessing these effects is important for obtaining accurate and reliable results. In this study, three series of RADARSAT-2 SAR images were evaluated. In each of these series, the sensor configuration was fixed, but the environmental conditions differed. The effects of variable environmental conditions were also investigated on co- and cross-polarized backscattering coefficients, Freeman-Durden scattering contributions, and the pedestal height in different classes of a forest area in Ottawa, Ontario. It was observed that the backscattering coefficient of wet snow was up to 2 dB more than that of dry snow. The absence of snow also caused a decrease of up to 3 dB in the surface scattering of ground and up to 5 dB in that of trees. In addition, the backscatter coefficients of ground vegetation, hardwood species, and softwood species were more similar at temperatures below 0°C than those at temperatures above 0°C. Moreover, the pedestal height was generally greater at temperatures above 0°C than at temperatures below 0°C. Finally, the highest class separability was observed when the temperature was at or above 0°C and there was no snow on the ground or trees.

GROSS N TRANSFORMATION RATES AND MICROBIAL POPULATION DYNAMICS UNDER FIELD AND LABORATORY CONDITIONS FROM TWO DIFFERENT ECOSYSTEMS

EPA Science Inventory

Change of soil and environmental conditions can influence microbial activities and subsequent soil nitrogen (N) transformation processes. The objective of this study was to compare gross N transformation rates between field and laboratory incubation conditions using an old-field...

[Overweight and obesity in schoolchildren from Brandsen and its relationship with socio-environmental characteristics of residence].

PubMed

Cesani, María F; Luis, María A; Torres, María F; Castro, Luis E; Quintero, Fabián A; Luna, María E; Bergel, María L; Oyhenart, Evelia E

2010-08-01

Environmental factors play an important role in the etiology of overweight (S) and obesity (O), constituting the "obesogenic environment". The objectives of the present study are: a) to estimate overweight and obesity prevalences in 3 to 14 years-old schoolchildren from Brandsen (Provincia de Buenos Aires), and b) to analyze the probability of occurrence of overweight and obesity in relation to the socioenvironmental conditions of resident. Weight and height were measured in 989 boys and girls aged 3 to 14 years. S and O were estimated following the criteria suggested by the International Obesity Task Force. The prevalences of S and O were compared between genders and ages. The socio- environmental information was gathered according to surveys and processed by Categorical Principal Components Analysis (catPCA). Generalized Linear Model (link logit) against the variables S and O was employed. S was found in 15,8% of schoolchildren and O in 7,2%. None significative statistics differences between both genders and ages, were found. The first axis of the catPCA discriminated the cases that presented better socio-environmental conditions with positive values and those with more unfavorable conditions with negatives values. Higher probability of obese children was associated with better socio-environmental conditions (higher educational level of parents, higher income and better access to public services), and higher probability of overweight children was associated with less favored environments. The schoolchildren population of Brandsen presents high overweight and obesity prevalences. The chance of presenting overweight is higher in children from households with adverse socio-environmental conditions. On the contrary, obese children are to be more found in households which have more favorable socio-environmental conditions.

Evidence supporting the match/mismatch hypothesis of psychiatric disorders.

PubMed

Santarelli, Sara; Lesuis, Sylvie L; Wang, Xiao-Dong; Wagner, Klaus V; Hartmann, Jakob; Labermaier, Christiana; Scharf, Sebastian H; Müller, Marianne B; Holsboer, Florian; Schmidt, Mathias V

2014-06-01

Chronic stress is one of the predominant environmental risk factors for a number of psychiatric disorders, particularly for major depression. Different hypotheses have been formulated to address the interaction between early and adult chronic stress in psychiatric disease vulnerability. The match/mismatch hypothesis of psychiatric disease states that the early life environment shapes coping strategies in a manner that enables individuals to optimally face similar environments later in life. We tested this hypothesis in female Balb/c mice that underwent either stress or enrichment early in life and were in adulthood further subdivided in single or group housed, in order to provide aversive or positive adult environments, respectively. We studied the effects of the environmental manipulation on anxiety-like, depressive-like and sociability behaviors and gene expression profiles. We show that continuous exposure to adverse environments (matched condition) is not necessarily resulting in an opposite phenotype compared to a continuous supportive environment (matched condition). Rather, animals with mismatched environmental conditions behaved differently from animals with matched environments on anxious, social and depressive like phenotypes. These results further support the match/mismatch hypothesis and illustrate how mild or moderate aversive conditions during development can shape an individual to be optimally adapted to similar conditions later in life. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

Functional traits determine plant co-occurrence more than environment or evolutionary relatedness in global drylands.

PubMed

Soliveres, Santiago; Maestre, Fernando T; Bowker, Matthew A; Torices, Rubén; Quero, José L; García-Gómez, Miguel; Cabrera, Omar; Cea, Alex; Coaguila, Daniel; Eldridge, David J; Espinosa, Carlos I; Hemmings, Frank; Monerris, Jorge J; Tighe, Matthew; Delgado-Baquerizo, Manuel; Escolar, Cristina; García-Palacios, Pablo; Gozalo, Beatriz; Ochoa, Victoria; Blones, Julio; Derak, Mchich; Ghiloufi, Wahida; Gutiérrez, Julio R; Hernández, Rosa M; Noumi, Zouhaier

2014-08-20

Plant-plant interactions are driven by environmental conditions, evolutionary relationships (ER) and the functional traits of the plants involved. However, studies addressing the relative importance of these drivers are rare, but crucial to improve our predictions of the effects of plant-plant interactions on plant communities and of how they respond to differing environmental conditions. To analyze the relative importance of -and interrelationships among- these factors as drivers of plant-plant interactions, we analyzed perennial plant co-occurrence at 106 dryland plant communities established across rainfall gradients in nine countries. We used structural equation modeling to disentangle the relationships between environmental conditions (aridity and soil fertility), functional traits extracted from the literature, and ER, and to assess their relative importance as drivers of the 929 pairwise plant-plant co-occurrence levels measured. Functional traits, specifically facilitated plants' height and nurse growth form, were of primary importance, and modulated the effect of the environment and ER on plant-plant interactions. Environmental conditions and ER were important mainly for those interactions involving woody and graminoid nurses, respectively. The relative importance of different plant-plant interaction drivers (ER, functional traits, and the environment) varied depending on the region considered, illustrating the difficulty of predicting the outcome of plant-plant interactions at broader spatial scales. In our global-scale study on drylands, plant-plant interactions were more strongly related to functional traits of the species involved than to the environmental variables considered. Thus, moving to a trait-based facilitation/competition approach help to predict that: 1) positive plant-plant interactions are more likely to occur for taller facilitated species in drylands, and 2) plant-plant interactions within woody-dominated ecosystems might be more sensitive to changing environmental conditions than those within grasslands. By providing insights on which species are likely to better perform beneath a given neighbour, our results will also help to succeed in restoration practices involving the use of nurse plants.

Functional traits determine plant co-occurrence more than environment or evolutionary relatedness in global drylands

PubMed Central

Soliveres, Santiago; Maestre, Fernando T.; Bowker, Matthew A.; Torices, Rubén; Quero, José L.; García-Gómez, Miguel; Cabrera, Omar; Cea, Alex; Coaguila, Daniel; Eldridge, David J.; Espinosa, Carlos I.; Hemmings, Frank; Monerris, Jorge J.; Tighe, Matthew; Delgado-Baquerizo, Manuel; Escolar, Cristina; García-Palacios, Pablo; Gozalo, Beatriz; Ochoa, Victoria; Blones, Julio; Derak, Mchich; Ghiloufi, Wahida; Gutiérrez, Julio R.; Hernández, Rosa M.; Noumi, Zouhaier

2015-01-01

Plant-plant interactions are driven by environmental conditions, evolutionary relationships (ER) and the functional traits of the plants involved. However, studies addressing the relative importance of these drivers are rare, but crucial to improve our predictions of the effects of plant-plant interactions on plant communities and of how they respond to differing environmental conditions. To analyze the relative importance of –and interrelationships among– these factors as drivers of plant-plant interactions, we analyzed perennial plant co-occurrence at 106 dryland plant communities established across rainfall gradients in nine countries. We used structural equation modeling to disentangle the relationships between environmental conditions (aridity and soil fertility), functional traits extracted from the literature, and ER, and to assess their relative importance as drivers of the 929 pairwise plant-plant co-occurrence levels measured. Functional traits, specifically facilitated plants’ height and nurse growth form, were of primary importance, and modulated the effect of the environment and ER on plant-plant interactions. Environmental conditions and ER were important mainly for those interactions involving woody and graminoid nurses, respectively. The relative importance of different plant-plant interaction drivers (ER, functional traits, and the environment) varied depending on the region considered, illustrating the difficulty of predicting the outcome of plant-plant interactions at broader spatial scales. In our global-scale study on drylands, plant-plant interactions were more strongly related to functional traits of the species involved than to the environmental variables considered. Thus, moving to a trait-based facilitation/competition approach help to predict that: 1) positive plant-plant interactions are more likely to occur for taller facilitated species in drylands, and 2) plant-plant interactions within woody-dominated ecosystems might be more sensitive to changing environmental conditions than those within grasslands. By providing insights on which species are likely to better perform beneath a given neighbour, our results will also help to succeed in restoration practices involving the use of nurse plants. PMID:25914604

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Şengör, S. Sevinç; Singh, Gursharan; Dohnalkova, Alice

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 inmore » 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.« less

Effects of carbon, nitrogen and ambient pH on patulin production and related gene expression in Penicillium expansum.

PubMed

Zong, Yuanyuan; Li, Boqiang; Tian, Shiping

2015-08-03

Patulin, a potent mycotoxin which can cause serious health concerns, is mainly produced in foods by Penicillium expansum. Environmental factors play important roles in regulating biosynthesis of mycotoxins; however, information about the effects of environmental factors on patulin production and the involved mechanisms in P. expansum is limited. Here, we investigated the effects of different carbon (C) and nitrogen (N) sources, and ambient pH on patulin production in three P. expansum strains T01, M1 and Pe21, and the expression profile of 15 genes involved in patulin biosynthetic pathway. It was found that C and N sources and pH had great influence on patulin production in P. expansum. In general, patulin production of all three P. expansum strains showed similar trends under different C and N sources and pH conditions, though there were some differences in the optimal conditions among these strains. Glucose-containing sugars, complex N sources, and acidic conditions were favorable conditions for patulin production. The results of RT-qPCR showed that the relative expressions of most of the patulin genes were up-regulated under patulin-permissive conditions, indicating that patulin biosynthesis was mainly regulated at transcriptional level by these environmental factors. These findings will provide useful information to better understand the regulation mechanisms of patulin biosynthesis, and be helpful in developing effective means for controlling patulin contamination. Copyright © 2015 Elsevier B.V. All rights reserved.

Electron efficiency of nZVI does not change with variation of environmental parameters.

PubMed

Schöftner, Philipp; Waldner, Georg; Lottermoser, Werner; Stöger-Pollach, Michael; Freitag, Peter; Reichenauer, Thomas G

2015-12-01

Nanoscale zero-valent iron particles (nZVI) are already applied for in-situ dechlorination of halogenated organic contaminants in the field. We performed batch experiments whereby trichloroethene (TCE) was dehalogenated by nZVI under different environmental conditions that are relevant in practice. The tested conditions include different ionic strengths, addition of polyelectrolytes (carboxymethylcellulose and ligninsulphonate), lowered temperature, dissolved oxygen and different particle contents. Particle properties were determined by Mössbauer spectroscopy, XRD, TEM, SEM, AAS and laser obscuration time measurements. TCE dehalogenation and H2 evolution were decelerated by reduced ionic strength, addition of polyelectrolytes, temperature reduction, the presence of dissolved oxygen and reduced particle content. The partitioning of released electrons between reactions with the contaminant vs. with water (selectivity) was low, independent of the tested conditions. Basically out of hundred electrons that were released via nZVI oxidation only 3.1±1.4 were used for TCE dehalogenation. Even lower selectivities were observed at TCE concentrations below 3.5 mg l(-1), hence particle modifications and/or combination of nZVI with other remediation technologies seem to be necessary to reach target concentrations for remediation. Our results suggest that selectivity is particle intrinsic and not as much condition dependent, hence particle synthesis and potential particle modifications of nZVI particles may be more important for optimization of the pollutant degradation rate, than tested environmental conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Arc tracking of cables for space applications

NASA Technical Reports Server (NTRS)

Koenig, D.; Frontzek, F. R.; Hanson, J.; Reher, H. J.; Judd, M. D.; Bryant, D.

1995-01-01

The main objective of this study is to develop a new test method that is suitable for the assessment of the resistance of aerospace cables to arc tracking for different specific environmental and network conditions of spacecrafts. This paper reports the purpose, test conditions, test specimen, test procedure, and test acceptance criteria of seven different (200-250 mm long) cables.

Physiological and foliar symptom response of Prunus serotina, Fraxinus americana and Acer rubrum canopy trees to ozone under differing site conditions

Treesearch

M. Schaub; J.M. Skelly; J.W. Zhang; J.A. Ferdinand; J.E. Savage; R.E. Stevenson; D.D. Davis; K.C. Steiner

2005-01-01

The crowns of five canopy dominant black cherry ( Prunus serotina Ehrh.), five white ash ( Fraxinus americana L.), and six red maple ( Acer rubrum L.) trees on naturally differing environmental conditions were accessed with scaffold towers within a mixed hardwood forest stand in central Pennsylvania....

Influenza transmission during extreme indoor conditions in a low-resource tropical setting

NASA Astrophysics Data System (ADS)

Tamerius, James; Ojeda, Sergio; Uejio, Christopher K.; Shaman, Jeffrey; Lopez, Brenda; Sanchez, Nery; Gordon, Aubree

2017-04-01

Influenza transmission occurs throughout the planet across wide-ranging environmental conditions. However, our understanding of the environmental factors mediating transmission is evaluated using outdoor environmental measurements, which may not be representative of the indoor conditions where influenza is transmitted. In this study, we examined the relationship between indoor environment and influenza transmission in a low-resource tropical population. We used a case-based ascertainment design to enroll 34 households with a suspected influenza case and then monitored households for influenza, while recording indoor temperature and humidity data in each household. We show that the indoor environment is not commensurate with outdoor conditions and that the relationship between indoor and outdoor conditions varies significantly across homes. We also show evidence of influenza transmission in extreme indoor environments. Specifically, our data suggests that indoor environments averaged 29 °C, 18 g/kg specific humidity, and 68 % relative humidity across 15 transmission events observed. These indoor settings also exhibited significant temporal variability with temperatures as high as 39 °C and specific and relative humidity increasing to 22 g/kg and 85 %, respectively, during some transmission events. However, we were unable to detect differences in the transmission efficiency by indoor temperature or humidity conditions. Overall, these results indicate that laboratory studies investigating influenza transmission and virus survival should increase the range of environmental conditions that they assess and that observational studies investigating the relationship between environment and influenza activity should use caution using outdoor environmental measurements since they can be imprecise estimates of the conditions that mediate transmission indoors.

Influenza transmission during extreme indoor conditions in a low-resource tropical setting.

PubMed

Tamerius, James; Ojeda, Sergio; Uejio, Christopher K; Shaman, Jeffrey; Lopez, Brenda; Sanchez, Nery; Gordon, Aubree

2017-04-01

Influenza transmission occurs throughout the planet across wide-ranging environmental conditions. However, our understanding of the environmental factors mediating transmission is evaluated using outdoor environmental measurements, which may not be representative of the indoor conditions where influenza is transmitted. In this study, we examined the relationship between indoor environment and influenza transmission in a low-resource tropical population. We used a case-based ascertainment design to enroll 34 households with a suspected influenza case and then monitored households for influenza, while recording indoor temperature and humidity data in each household. We show that the indoor environment is not commensurate with outdoor conditions and that the relationship between indoor and outdoor conditions varies significantly across homes. We also show evidence of influenza transmission in extreme indoor environments. Specifically, our data suggests that indoor environments averaged 29 °C, 18 g/kg specific humidity, and 68 % relative humidity across 15 transmission events observed. These indoor settings also exhibited significant temporal variability with temperatures as high as 39 °C and specific and relative humidity increasing to 22 g/kg and 85 %, respectively, during some transmission events. However, we were unable to detect differences in the transmission efficiency by indoor temperature or humidity conditions. Overall, these results indicate that laboratory studies investigating influenza transmission and virus survival should increase the range of environmental conditions that they assess and that observational studies investigating the relationship between environment and influenza activity should use caution using outdoor environmental measurements since they can be imprecise estimates of the conditions that mediate transmission indoors.

Selective effect of myclobutanil enantiomers on fungicidal activity and fumonisin production by Fusarium verticillioides under different environmental conditions.

PubMed

Li, Na; Deng, Luqing; Li, Jianfang; Wang, Zhengbing; Han, Yiye; Liu, Chenglan

2018-05-01

Myclobutanil is a widely used triazole fungicide, comprising two enantiomers with different fungicidal activities, non-target toxicities, and environmental fates. The enantioselective effects of myclobutanil on fumonisin B (FB) production by Fusarium verticillioides, an important pathogen, have not yet been investigated. In the present study, the fungicidal activities of rac-myclobutanil and its enantiomers on F. verticillioides cultured on maize-based media were studied under different water activity and temperature conditions. The FB levels were measured to assess the enantioselective effects on FB production when F. verticillioides were cultured treated with EC 50 and EC 90 concentrations (concentrations inhibiting mycelial growth by 50.0% and 90.0%, respectively) of myclobutanil and enantiomers under different conditions. The fungicidal activities of rac-myclobutanil and its enantiomers decreased with increasing temperature and decreasing water activity. Little difference in fungicidal activity was observed between the enantiomers. FB production was significantly influenced by temperature, a w , and fungicides dose. At EC50 concentrations, rac-myclobutantil and its enantiomers were shown to enhance mycotoxin production and enantioselective effects of enantiomers on FB production were observed under certain conditions. This is the first report on the differential effects of myclobutanil enantiomers on the control of F. verticillioides growth and FB production in maize-based media under different conditions. Copyright © 2018 Elsevier Inc. All rights reserved.

Intercomparison of chemical mechanisms for air quality policy formulation and assessment under North American conditions.

PubMed

Derwent, Richard

2017-07-01

The intercomparison of seven chemical mechanisms for their suitability for air quality policy formulation and assessment is described. Box modeling techniques were employed using 44 sets of background environmental conditions covering North America to constrain the chemical development of the longer lived species. The selected mechanisms were modified to enable an unbiased assessment of the adequacy of the parameterizations of photochemical ozone production from volatile organic compound (VOC) oxidation in the presence of NO x . Photochemical ozone production rates responded differently to 30% NO x and VOC reductions with the different mechanisms, despite the striking similarities between the base-case ozone production rates. The 30% reductions in NO x and VOCs also produced changes in OH. The responses in OH to 30% reductions in NO x and VOCs appeared to be more sensitive to mechanism choice, compared with the responses in the photochemical ozone production rates. Although 30% NO x reductions generally led to decreases in OH, 30% reductions in VOCs led to increases in OH, irrespective of mechanism choice and background environmental conditions. The different mechanisms therefore gave different OH responses to NO x and VOC reductions and so would give different responses in terms of changes in the fate and behavior of air toxics, acidification and eutrophication, and fine particle formation compared with others, in response to ozone control strategies. Policymakers need to understand that there are likely to be inherent differences in the responses to ozone control strategies between different mechanisms, depending on background environmental conditions and the extents of NO x and VOC reductions under consideration. The purpose of this paper is to compare predicted ozone responses to NO x and VOC reductions with seven chemical mechanisms under North American conditions. The good agreement found between the tested mechanisms should provide some support for their application in the air quality models used for policymaking.

Malate as a key carbon source of leaf dark-respired CO2 across different environmental conditions in potato plants.

PubMed

Lehmann, Marco M; Rinne, Katja T; Blessing, Carola; Siegwolf, Rolf T W; Buchmann, Nina; Werner, Roland A

2015-09-01

Dissimilation of carbon sources during plant respiration in support of metabolic processes results in the continuous release of CO2. The carbon isotopic composition of leaf dark-respired CO2 (i.e. δ (13) C R ) shows daily enrichments up to 14.8‰ under different environmental conditions. However, the reasons for this (13)C enrichment in leaf dark-respired CO2 are not fully understood, since daily changes in δ(13)C of putative leaf respiratory carbon sources (δ (13) C RS ) are not yet clear. Thus, we exposed potato plants (Solanum tuberosum) to different temperature and soil moisture treatments. We determined δ (13) C R with an in-tube incubation technique and δ (13) C RS with compound-specific isotope analysis during a daily cycle. The highest δ (13) C RS values were found in the organic acid malate under different environmental conditions, showing less negative values compared to δ (13) C R (up to 5.2‰) and compared to δ (13) C RS of soluble carbohydrates, citrate and starch (up to 8.8‰). Moreover, linear relationships between δ (13) C R and δ (13) C RS among different putative carbon sources were strongest for malate during daytime (r(2)=0.69, P≤0.001) and nighttime (r(2)=0.36, P≤0.001) under all environmental conditions. A multiple linear regression analysis revealed δ (13) C RS of malate as the most important carbon source influencing δ (13) C R . Thus, our results strongly indicate malate as a key carbon source of (13)C enriched dark-respired CO2 in potato plants, probably driven by an anapleurotic flux replenishing intermediates of the Krebs cycle. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Evaporative moisture loss from heterogeneous stone: Material-environment interactions during drying

NASA Astrophysics Data System (ADS)

McAllister, Daniel; Warke, Patricia; McCabe, Stephen; Gomez-Heras, M.

2016-11-01

The complexities of evaporation from structurally and mineralogically heterogeneous sandstone (Locharbriggs Sandstone) are investigated through a laboratory-based experiment in which a variety of environmental conditions are simulated. Data reported demonstrate the significance of material-environment interactions on the spatial and temporal variability of evaporative dynamics. Evaporation from porous stone is determined by the interplay between environmental, material and solution properties, which govern the rate and mode by which water is transmitted to, and subsequently removed from, an evaporating surface. Initially, when the stone is saturated, evaporation is characterized by high rates of moisture loss primarily controlled by external atmospheric conditions. However, as drying progresses, eventually the hydraulic continuity between the stone surface and subsurface is disrupted with recession of the drying front and a decrease in evaporation rates which become reliant on the ability of the material to transport water vapour to the block surface. Pore size distribution and connectivity, as well as other material properties, control the timing of each stage of evaporation and the nature of the transition. These experimental data highlight the complexity of evaporation, demonstrating that different regions of the same stone can exhibit varying moisture dynamics during drying and that the rate and nature of evaporative loss differs under different environmental conditions. The results identify the importance of material-environment interactions during drying and that stone micro-environmental conditions cannot be inferred from ambient data alone. These data have significance for understanding the spatial distribution of stone surface weathering-related morphologies in both the natural and built environments where mineralogical and/or structural heterogeneity creates differences in moisture flux and hence variable drying rates. Such differences may provide a clearer explanation for the initiation and subsequent development of complex weathering responses where areas of significant deterioration can be found alongside areas that exhibit little or no evidence of surface breakdown.

Trends in Trace Element Fractionation Between Foraminiferal Species and the Role of Biomineralization

NASA Astrophysics Data System (ADS)

Reichart, G. J.; Nooijer, L. D.; Geerken, E.; Mezger, E.; van Dijk, I. V.; Daemmer, L. K.

2017-12-01

Reconstructions of past climate and environments are largely based on stable isotopes and trace element concentrations measured on fossil foraminiferal calcite. Their element and isotope composition roughly reflects seawater composition and physical conditions, which in turn, are related to paleoceanographic parameters. More recently, attempts are being made to infer ranges in environmental parameters using the observed differences in the composition within individual tests. Remarkably, inter-species differences in trace element incorporation are well-correlated over a wide range of environmental conditions. This is particularly remarkable knowing that different environmental factors influence incorporation of these elements at various magnitudes. Most likely the complex biomineralization of foraminifera potentially offsets trace elements similarly at all these scales and also between different species. This suggests that at least parts of the mechanisms underlying foraminiferal biomineralization are similar for all species, which in turn provides important clues on the cellular mechanisms operating during calcification. Moreover, the systematics in trace element partitioning between species could potentially provide important clues for unravelling past changes in trace element composition of the ancient ocean.

Cultivation and Characterization of Oil-Degrading Microbes and the Environmental Controls on Hydrocarbon Biodegradation Patterns

NASA Astrophysics Data System (ADS)

Redmond, M. C.

2016-02-01

The Deepwater Horizon oil spill highlighted the ability of microbes to degrade hydrocarbons in both cold, deep water and at the warm sea surface. However, the temperature and differing hydrocarbons in the deep ocean and sea surface led to different microbial communities and biodegradation patterns. In order to develop a better understanding of the factors that control microbial community composition and biodegradation patterns, we conducted laboratory microcosm studies with seawater samples from coastal South Carolina and hydrocarbon seeps in the Gulf of Mexico, incubated with different hydrocarbons, at different temperatures, and in static or shaking incubation conditions. We analyzed microbial community composition after three weeks and used successive transfers on liquid and then solid media to isolate cultures. More rapid growth was observed at 28 degrees than 4 degrees, with hexadecane compared to benzene, cyclohexane, or crude oil, and in shaking incubations compared to static. However, we were able to successfully culture microbes under all conditions. Physiological and genetic characterization of isolated strains is ongoing, and will be combined with assessment of hydrocarbon substrate preferences and kinetics under different environmental conditions.

The effect of environmental conditions and soil physicochemistry on phosphate stabilisation of Pb in shooting range soils.

PubMed

Sanderson, Peter; Naidu, Ravi; Bolan, Nanthi

2016-04-01

The stabilisation of Pb in the soil by phosphate is influenced by environmental conditions and physicochemical properties of the soils to which it is applied. Stabilisation of Pb by phosphate was examined in four soils under different environmental conditions. The effect of soil moisture and temperature on stabilisation of Pb by phosphate was examined by measurement of water extractable and bioaccessible Pb, sequential fractionation and X-ray absorption spectroscopy. The addition of humic acid, ammonium nitrate and chloride was also examined for inhibition or improvement of Pb stability with phosphate treatment. The effect of moisture level varied between soils. In soil MB and DA a soil moisture level of 50% water holding capacity was sufficient to maximise stabilisation of Pb, but in soil TV and PE reduction in bioaccessible Pb was inhibited at this moisture level. Providing moisture at twice the soil water holding capacity did not enhance the effect of phosphate on Pb stabilisation. The difference of Pb stability as a result of incubating phosphate treated soils at 18 °C and 37 °C was relatively small. However wet-dry cycles decreased the effectiveness of phosphate treatment. The reduction in bioaccessible Pb obtained was between 20 and 40% with the most optimal treatment conditions. The reduction in water extractable Pb by phosphate was substantial regardless of incubation conditions and the effect of different temperature and soil moisture regimes was not significant. Selective sequential extraction showed phosphate treatment converted Pb in fraction 1 (exchangeable, acid and water soluble) to fraction 2 (reducible). There were small difference in fraction 4 (residual) Pb and fraction 1 as a result of treatment conditions. X-ray absorption spectroscopy of stabilised PE soil revealed small differences in Pb speciation under varying soil moisture and temperature treatments. The addition of humic acid and chloride produced the greatest effect on Pb speciation in phosphate treated soils. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Some anemonefish lack personality: a comparative assessment of behavioral variation and repeatability in relation to environmental and social factors

NASA Astrophysics Data System (ADS)

Wong, Marian Y. L.; Beasley, Amanda L.; Douglass, Tasman; Whalan, Steve; Scott, Anna

2017-12-01

Determining the extent of repeatable differences in the behavior of animals and the factors that influence behavioral expression is important for understanding individual fitness and population processes, thereby aiding in species conservation. However, little is known about the causes of variation in the repeatability of behavioral differences among species because rarely have comparative studies been undertaken to examine the repeatability of behavioral differences among individuals within their natural ecological settings. Using two species of endemic subtropical anemonefishes, Amphiprion mccullochi and A. latezonatus at Lord Howe and North Solitary Islands, Australia, we conducted an in situ comparative analysis of personality traits, examining the repeatability of boldness, sociability and aggression as well as the potential role of environmental and social factors on behavioral expression. For A. mccullochi, only boldness and aggression were highly repeatable and these behaviors formed a behavioral syndrome. For A. latezonatus, none of the three behaviors were repeatable due to low-inter-individual variation in behavior. We suggest that the harsher and more variable environmental and social conditions experienced by A. latezonatus have resulted in reduced repeatability in behavior, in contrast to A. mccullochi which typically inhabits a more stable lagoonal reef environment. Additionally, group size and size rank, rather than nearest-neighbor distance and anemone size, influenced the expression of these behaviors in both species, suggesting that behavioral variation was more sensitive to social than environmental factors. Overall, differences in repeatability between these closely related species likely reflect adaptations to contrasting environmental and social conditions, although alternative explanations must be considered. The differences in behavioral consistency between these two endemic anemonefishes could lead to disparity in their resilience to environmental or social change in the future.

Habitat Selection Response of Small Pelagic Fish in Different Environments. Two Examples from the Oligotrophic Mediterranean Sea

PubMed Central

Bonanno, Angelo; Giannoulaki, Marianna; Barra, Marco; Basilone, Gualtiero; Machias, Athanassios; Genovese, Simona; Goncharov, Sergey; Popov, Sergey; Rumolo, Paola; Di Bitetto, Massimiliano; Aronica, Salvatore; Patti, Bernardo; Fontana, Ignazio; Giacalone, Giovanni; Ferreri, Rosalia; Buscaino, Giuseppa; Somarakis, Stylianos; Pyrounaki, Maria-Myrto; Tsoukali, Stavroula; Mazzola, Salvatore

2014-01-01

A number of scientific papers in the last few years singled out the influence of environmental conditions on the spatial distribution of fish species, highlighting the need for the fisheries scientific community to investigate, besides biomass estimates, also the habitat selection of commercially important fish species. The Mediterranean Sea, although generally oligotrophic, is characterized by high habitat variability and represents an ideal study area to investigate the adaptive behavior of small pelagics under different environmental conditions. In this study the habitat selection of European anchovy Engraulis encrasicolus and European sardine Sardina pilchardus is analyzed in two areas of the Mediterranean Sea that largely differentiate in terms of environmental regimes: the Strait of Sicily and the North Aegean Sea. A number of environmental parameters were used to investigate factors influencing anchovy and sardine habitat selection. Acoustic surveys data, collected during the summer period 2002–2010, were used for this purpose. The quotient analysis was used to identify the association between high density values and environmental variables; it was applied to the entire dataset in each area in order to identify similarities or differences in the “mean” spatial behavioral pattern for each species. Principal component analysis was applied to selected environmental variables in order to identify those environmental regimes which drive each of the two ecosystems. The analysis revealed the effect of food availability along with bottom depth selection on the spatial distribution of both species. Furthermore PCA results highlighted that observed selectivity for shallower waters is mainly associated to specific environmental processes that locally increase productivity. The common trends in habitat selection of the two species, as observed in the two regions although they present marked differences in hydrodynamics, seem to be driven by the oligotrophic character of the study areas, highlighting the role of areas where the local environmental regimes meet ‘the ocean triad hypothesis’. PMID:24992576

Transitions in optimal adaptive strategies for populations in fluctuating environments

NASA Astrophysics Data System (ADS)

Mayer, Andreas; Mora, Thierry; Rivoire, Olivier; Walczak, Aleksandra M.

2017-09-01

Biological populations are subject to fluctuating environmental conditions. Different adaptive strategies can allow them to cope with these fluctuations: specialization to one particular environmental condition, adoption of a generalist phenotype that compromises between conditions, or population-wise diversification (bet hedging). Which strategy provides the largest selective advantage in the long run depends on the range of accessible phenotypes and the statistics of the environmental fluctuations. Here, we analyze this problem in a simple mathematical model of population growth. First, we review and extend a graphical method to identify the nature of the optimal strategy when the environmental fluctuations are uncorrelated. Temporal correlations in environmental fluctuations open up new strategies that rely on memory but are mathematically challenging to study: We present analytical results to address this challenge. We illustrate our general approach by analyzing optimal adaptive strategies in the presence of trade-offs that constrain the range of accessible phenotypes. Our results extend several previous studies and have applications to a variety of biological phenomena, from antibiotic resistance in bacteria to immune responses in vertebrates.

Integrated presentation of ecological risk from multiple stressors

NASA Astrophysics Data System (ADS)

Goussen, Benoit; Price, Oliver R.; Rendal, Cecilie; Ashauer, Roman

2016-10-01

Current environmental risk assessments (ERA) do not account explicitly for ecological factors (e.g. species composition, temperature or food availability) and multiple stressors. Assessing mixtures of chemical and ecological stressors is needed as well as accounting for variability in environmental conditions and uncertainty of data and models. Here we propose a novel probabilistic ERA framework to overcome these limitations, which focusses on visualising assessment outcomes by construct-ing and interpreting prevalence plots as a quantitative prediction of risk. Key components include environmental scenarios that integrate exposure and ecology, and ecological modelling of relevant endpoints to assess the effect of a combination of stressors. Our illustrative results demonstrate the importance of regional differences in environmental conditions and the confounding interactions of stressors. Using this framework and prevalence plots provides a risk-based approach that combines risk assessment and risk management in a meaningful way and presents a truly mechanistic alternative to the threshold approach. Even whilst research continues to improve the underlying models and data, regulators and decision makers can already use the framework and prevalence plots. The integration of multiple stressors, environmental conditions and variability makes ERA more relevant and realistic.

Integrated presentation of ecological risk from multiple stressors.

PubMed

Goussen, Benoit; Price, Oliver R; Rendal, Cecilie; Ashauer, Roman

2016-10-26

Current environmental risk assessments (ERA) do not account explicitly for ecological factors (e.g. species composition, temperature or food availability) and multiple stressors. Assessing mixtures of chemical and ecological stressors is needed as well as accounting for variability in environmental conditions and uncertainty of data and models. Here we propose a novel probabilistic ERA framework to overcome these limitations, which focusses on visualising assessment outcomes by construct-ing and interpreting prevalence plots as a quantitative prediction of risk. Key components include environmental scenarios that integrate exposure and ecology, and ecological modelling of relevant endpoints to assess the effect of a combination of stressors. Our illustrative results demonstrate the importance of regional differences in environmental conditions and the confounding interactions of stressors. Using this framework and prevalence plots provides a risk-based approach that combines risk assessment and risk management in a meaningful way and presents a truly mechanistic alternative to the threshold approach. Even whilst research continues to improve the underlying models and data, regulators and decision makers can already use the framework and prevalence plots. The integration of multiple stressors, environmental conditions and variability makes ERA more relevant and realistic.

Macro and Microenvironments at the British Library.

ERIC Educational Resources Information Center

Shenton, Helen

This paper describes the storage of the 12 million items that have just been moved into the new British Library building. The specifications for the storage and environmental conditions for different types of library and archive material are explained. The varying environmental parameters for storage areas and public areas, including reading rooms…

Age, state, environment, and season dependence of senescence in body mass.

PubMed

Kroeger, Svenja B; Blumstein, Daniel T; Armitage, Kenneth B; Reid, Jane M; Martin, Julien G A

2018-02-01

Senescence is a highly variable process that comprises both age-dependent and state-dependent components and can be greatly affected by environmental conditions. However, few studies have quantified the magnitude of age-dependent and state-dependent senescence in key life-history traits across individuals inhabiting different spatially structured and seasonal environments. We used longitudinal data from wild female yellow-bellied marmots ( Marmota flaviventer ), living in two adjacent environments that differ in elevation and associated phenology, to quantify how age and individual state, measured as "time to death," affect body mass senescence in different environments. Further, we quantified how patterns of senescence differed between two biologically distinct seasons, spring, and late summer. Body mass senescence had an age-dependent component, expressed as a decrease in mass in old age. Overall, estimated age-dependent senescence was greater in females living in the more favorable lower elevation environment, than in the harsher higher elevation environment, and greater in late summer than in spring. Body mass senescence also had a state-dependent component, captured by effects of time to death, but only in the more favorable lower elevation environment. In spring, body mass gradually decreased from 2 years before death, whereas in late summer, state-dependent effects were expressed as a terminal decrease in body mass in the last year of life. Contrary to expectations, we found that senescence was more likely to be observed under more favorable environmental conditions, rather than under harsher conditions. By further demonstrating that senescence patterns differ among seasons, our results imply that within-year temporal environmental variation must be considered alongside spatial environmental variation in order to characterize and understand the pattern and magnitude of senescence in wild populations.

SeaConditions: a web and mobile service for safer professional and recreational activities in the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Coppini, Giovanni; Marra, Palmalisa; Lecci, Rita; Pinardi, Nadia; Cretì, Sergio; Scalas, Mario; Tedesco, Luca; D'Anca, Alessandro; Fazioli, Leopoldo; Olita, Antonio; Turrisi, Giuseppe; Palazzo, Cosimo; Aloisio, Giovanni; Fiore, Sandro; Bonaduce, Antonio; Vittal Kumkar, Yogesh; Ciliberti, Stefania Angela; Federico, Ivan; Mannarini, Gianandrea; Agostini, Paola; Bonarelli, Roberto; Martinelli, Sara; Verri, Giorgia; Lusito, Letizia; Rollo, Davide; Cavallo, Arturo; Tumolo, Antonio; Monacizzo, Tony; Spagnulo, Marco; Sorgente, Rorberto; Cucco, Andrea; Quattrocchi, Giovanni; Tonani, Marina; Drudi, Massimiliano; Nassisi, Paola; Conte, Laura; Panzera, Laura; Navarra, Antonio; Negro, Giancarlo

2017-04-01

Reliable and timely information on the environmental conditions at sea is key to the safety of professional and recreational users as well as to the optimal execution of their activities. The possibility of users obtaining environmental information in due time and with adequate accuracy in the marine and coastal environment is defined as sea situational awareness (SSA). Without adequate information on the environmental meteorological and oceanographic conditions, users have a limited capacity to respond, which has led to loss of lives and to large environmental disasters with enormous consequent damage to the economy, society and ecosystems. Within the framework of the TESSA project, new SSA services for the Mediterranean Sea have been developed. In this paper we present SeaConditions, which is a web and mobile application for the provision of meteorological and oceanographic observation and forecasting products. Model forecasts and satellite products from operational services, such as ECMWF and CMEMS, can be visualized in SeaConditions. In addition, layers of information related to bathymetry, sea level and ocean-colour data (chl a and water transparency) are displayed. Ocean forecasts at high spatial resolutions are included in the version of SeaConditions presented here. SeaConditions provides a user-friendly experience with a fluid zoom capability, facilitating the appropriate display of data with different levels of detail. SeaConditions is a single point of access to interactive maps from different geophysical fields, providing high-quality information based on advanced oceanographic models. The SeaConditions services are available through both web and mobile applications. The web application is available at www.sea-conditions.com and is accessible and compatible with present-day browsers. Interoperability with GIS software is implemented. User feedback has been collected and taken into account in order to improve the service. The SeaConditions iOS and Android apps have been downloaded by more than 105 000 users to date (May 2016), and more than 100 000 users have visited the web version.

Coupling Eco-Physiology and Shell Geochemistry of California Mussels: Carry-Over Effects of Larval Exposure to Upwelling and Relaxation Regimes

NASA Astrophysics Data System (ADS)

Rivest, E.; Hill, T. M.; Gaylord, B.; Sanford, E.; Fehrenbacher, J. S.; Russell, A. D.

2016-02-01

Laboratory studies have shown that environmental conditions experienced by marine invertebrate larvae can create long-lasting effects that shape the performance of juvenile and adult stages. In a naturally variable marine environment, establishing the link between the in situ environmental exposure of an animal and its physiological performance will enhance our predictions of the biological consequences of long-term anthropogenic change. However, in study systems such as zooplankton communities, it is often difficult to reconstruct the environmental conditions to which study organisms have been exposed. Here, we tested how differing histories of environmental exposure during the larval phase shape the subsequent performance of benthic Mytilus californianus mussel recruits. In particular, we reconstructed the in situ pH conditions experienced by mussels during planktonic dispersal by analyzing remnants of their larval shells for the composition of U/Ca, a recently developed biogeochemical proxy. Six cohorts of mussel recruits, each obtained from a two-week deployment of collectors in the intertidal zone at Bodega Marine Reserve, CA, were analyzed to assess rates of oxygen consumption, condition index, growth rate, and shell thickness. Metabolic rate was higher for recruits that arrived during periods of upwelling vs. those that arrived during conditions of relaxation or non-upwelling. However, other metrics of performance did not differ among these groups. We also correlated individual performance with pH exposure of the larval stage estimated from shell U/Ca. Future ocean acidification may intensify these biological responses to underlying variability in coastal ocean chemistry.

Effects of temperature and Ca2+ on the larval development of the decapoda crustacean: Eriocheir sinensis

NASA Astrophysics Data System (ADS)

Huang, Bo; Du, Nan-Shan; Lai, Wei

2001-09-01

With increasing demand in China for the mitten crab larvae, understanding its survival mechanism gets more important. This research focused on the effects of temperature and Ca2+ on the larval growth and development. Eriocheir sinensis larvae were reared in laboratory under, 21 different combinations of temperature (15, 20, 25°C) and Ca2+ content (120, 130, 140, 150, 160, 170, 180 mg/l) and constant salinity (20) and pH (8). The results suggested that the survival rate increases with temperature and Ca2+ content. These combinations of temperature and Ca2+ content maximized survival rate in our study and it may be the optimum water environmental conditions for culturing, the larvae. To predict surviving larvae number under different water environmental conditions, 21 dynamic mathematical models were developed. This for the first time observation of the zoeal VI larvae of the Changjiang River E. sinesis population showed that they occurred under stressed water environmental conditions: temperature of 15°C and Ca2+ content of 120, 130 mg/l.

Species traits and environmental conditions govern the relationship between biodiversity effects across trophic levels

USGS Publications Warehouse

Spooner, D.E.; Vaughn, C.C.; Galbraith, H.S.

2012-01-01

Changing environments can have divergent effects on biodiversity-ecosystem function relationships at alternating trophic levels. Freshwater mussels fertilize stream foodwebs through nutrient excretion, and mussel species-specific excretion rates depend on environmental conditions. We asked how differences in mussel diversity in varying environments influence the dynamics between primary producers and consumers. We conducted field experiments manipulating mussel richness under summer (low flow, high temperature) and fall (moderate flow and temperature) conditions, measured nutrient limitation, algal biomass and grazing chironomid abundance, and analyzed the data with non-transgressive overyielding and tripartite biodiversity partitioning analyses. Algal biomass and chironomid abundance were best explained by trait-independent complementarity among mussel species, but the relationship between biodiversity effects across trophic levels (algae and grazers) depended on seasonal differences in mussel species' trait expression (nutrient excretion and activity level). Both species identity and overall diversity effects were related to the magnitude of nutrient limitation. Our results demonstrate that biodiversity of a resource-provisioning (nutrients and habitat) group of species influences foodweb dynamics and that understanding species traits and environmental context are important for interpreting biodiversity experiments. ?? 2011 Springer-Verlag.

A dedicated system for topographical working memory: evidence from domain-specific interference tests.

PubMed

Piccardi, L; Nori, R; Boccia, M; Barbetti, S; Verde, P; Guariglia, C; Ferlazzo, F

2015-08-01

In the present study, we used single- and dual-task conditions to investigate the nature of topographical working memory to better understand what type of task can hamper performance during navigation. During dual-task conditions, we considered four different sources of interference: motor (M), spatial motor (SM), verbal (i.e. articulatory suppression AS) and spatial environmental (SE). In order to assess the nature of topographical working memory, we used the Walking Corsi Test, asking the participants to perform two tasks simultaneously (M, SM, AS and SE). Our results showed that only spatial-environmental interference hampers the execution of a topographical working memory task, suggesting a task-domain-specific effect. We also found general gender differences in the topographical working memory capabilities: men were more proficient than women, regardless of the type of interferences. However, like men, women performed worse when a spatial-environmental interference was present.

GPR Imaging for Deeply Buried Objects: A Comparative Study Based on FDTD Models and Field Experiments

NASA Technical Reports Server (NTRS)

Tilley, roger; Dowla, Farid; Nekoogar, Faranak; Sadjadpour, Hamid

2012-01-01

Conventional use of Ground Penetrating Radar (GPR) is hampered by variations in background environmental conditions, such as water content in soil, resulting in poor repeatability of results over long periods of time when the radar pulse characteristics are kept the same. Target objects types might include voids, tunnels, unexploded ordinance, etc. The long-term objective of this work is to develop methods that would extend the use of GPR under various environmental and soil conditions provided an optimal set of radar parameters (such as frequency, bandwidth, and sensor configuration) are adaptively employed based on the ground conditions. Towards that objective, developing Finite Difference Time Domain (FDTD) GPR models, verified by experimental results, would allow us to develop analytical and experimental techniques to control radar parameters to obtain consistent GPR images with changing ground conditions. Reported here is an attempt at developing 20 and 3D FDTD models of buried targets verified by two different radar systems capable of operating over different soil conditions. Experimental radar data employed were from a custom designed high-frequency (200 MHz) multi-static sensor platform capable of producing 3-D images, and longer wavelength (25 MHz) COTS radar (Pulse EKKO 100) capable of producing 2-D images. Our results indicate different types of radar can produce consistent images.

[Editorial] Environmental and occupational risk factors associated with different pathological conditions.

PubMed

Signorelli, Salvatore Santo; Ferrante, Margherita

2017-05-01

A wide body of evidence indicates that environmental and occupational risk factors are associated with the development of pathological disorders. The pathogenic role of many environmental pollutants or occupational contaminants is already known and has been extensively investigated. However, the molecular mechanisms of action and the pathogenic effects of many substances remain unknown. Therefore, there is a need to better investigate the role of new environmental and occupational risk factors that may cause the development of several diseases.

Nonlinear dynamics of the CAM circadian rhythm in response to environmental forcing.

PubMed

Hartzell, Samantha; Bartlett, Mark S; Virgin, Lawrence; Porporato, Amilcare

2015-03-07

Crassulacean acid metabolism (CAM) photosynthesis functions as an endogenous circadian rhythm coupled to external environmental forcings of energy and water availability. This paper explores the nonlinear dynamics of a new CAM photosynthesis model (Bartlett et al., 2014) and investigates the responses of CAM plant carbon assimilation to different combinations of environmental conditions. The CAM model (Bartlett et al., 2014) consists of a Calvin cycle typical of C3 plants coupled to an oscillator of the type employed in the Van der Pol and FitzHugh-Nagumo systems. This coupled system is a function of environmental variables including leaf temperature, leaf moisture potential, and irradiance. Here, we explore the qualitative response of the system and the expected carbon assimilation under constant and periodically forced environmental conditions. The model results show how the diurnal evolution of these variables entrains the CAM cycle with prevailing environmental conditions. While constant environmental conditions generate either steady-state or periodically oscillating responses in malic acid uptake and release, forcing the CAM system with periodic daily fluctuations in light exposure and leaf temperature results in quasi-periodicity and possible chaos for certain ranges of these variables. This analysis is a first step in quantifying changes in CAM plant productivity with variables such as the mean temperature, daily temperature range, irradiance, and leaf moisture potential. Results may also be used to inform model parametrization based on the observed fluctuating regime. Copyright © 2014 Elsevier Ltd. All rights reserved.

Endogenous Circadian Regulation of Pro-inflammatory Cytokines and Chemokines in the Presence of Bacterial Lipopolysaccharide in Humans

PubMed Central

Rahman, Shadab A.; Castanon-Cervantes, Oscar; Scheer, Frank A.J.L.; Shea, Steven A.; Czeisler, Charles A.; Davidson, Alec J.; Lockley, Steven W.

2015-01-01

Various aspects of immune response exhibit 24-hour variations suggesting that infection susceptibility and treatment efficacy may vary by time of day. Whether these 24-hour variations are endogenous or evoked by changes in environmental or behavioral conditions is not known. We assessed the endogenous circadian control and environmental and behavioral influences on ex-vivo lipopolysaccharide stimulation of whole blood in thirteen healthy participants under 48 hours of baseline conditions with standard sleep-wake schedules and 40–50 hours of constant environmental and behavioral (constant routine; CR) conditions. Significant 24-hour rhythms were observed under baseline conditions in Monocyte Chemotactic Protein, Granulocyte-Macrophage Colony-Stimulating Factor and Interleukin 8 but not Tumor Necrosis Factor alpha whereas significant 24-hour rhythms were observed in all four immune factors under CR conditions. The rhythm amplitudes, expressed as a percentage of mean, were comparable between immune factors and across conditions. In contrast, the acrophase time (time of the fitted peak) was different between immune factors, and included daytime and nighttime peaks and changes across behavioral conditions. These results suggest that the endogenous circadian system underpins the temporal organization of immune responses in humans with additional effects of external environmental and behavioral cycles. These findings have implications for understanding the adverse effects of recurrent circadian disruption and sleep curtailment on immune function. PMID:25452149

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.

Multicenter Study on Incubation Conditions for Environmental Monitoring and Aseptic Process Simulation.

PubMed

Guinet, Roland; Berthoumieu, Nicole; Dutot, Philippe; Triquet, Julien; Ratajczak, Medhi; Thibaudon, Michel; Bechaud, Philippe; Arliaud, Christophe; Miclet, Edith; Giordano, Florine; Larcon, Marjorie; Arthaud, Catherine

Environmental monitoring and aseptic process simulations represent an integral part of the microbiological quality control system of sterile pharmaceutical products manufacturing operations. However, guidance documents and manufacturers practices differ regarding recommendations for incubation time and incubation temperature, and, consequently, the environmental monitoring and aseptic process simulation incubation strategy should be supported by validation data. To avoid any bias coming from in vitro studies or from single-site manufacturing in situ studies, we performed a collaborative study at four manufacturing sites with four samples at each location. The environmental monitoring study was performed with tryptic soy agar settle plates and contact plates, and the aseptic process simulation study was performed with tryptic soy broth and thioglycolate broth. The highest recovery rate was obtained with settle plates (97.7%) followed by contact plates (65.4%) and was less than 20% for liquid media (tryptic soy broth 19% and thioglycolate broth 17%). Gram-positive cocci and non-spore-forming Gram-positive rods were largely predominant with more than 95% of growth and recovered best at 32.5 °C. The highest recovery of molds was obtained at 22.5 °C alone or as the first incubation temperature. Strict anaerobes were not recovered. At the end of the five days of incubation no significant statistical difference was obtained between the four conditions. Based on these data a single incubation temperature at 32.5 °C could be recommended for these four manufacturing sites for both environmental monitoring and aseptic process simulation, and a second plate could be used, periodically incubated at 22.5 °C. Similar studies should be considered for all manufacturing facilities in order to determine the optimal incubation temperature regime for both viable environmental monitoring and aseptic process simulation. Microbiological environmental monitoring and aseptic process simulation confirm that pharmaceutical cleanrooms are in an appropriate hygienic condition for manufacturing of sterile drug products. Guidance documents from different health authorities or expert groups differ regarding recommendation of the applied incubation time and incubation temperature, leading to variable manufacturers practices. Some recent publications have demonstrated that laboratory studies are not relevant to determine the best incubation regime and that in situ manufacturing site studies should be used. To solve any possible bias coming from laboratory studies or single-site in situ studies, we conducted a multicenter study at four manufacturing sites with a significant amount of real environmental monitoring samples collected directly from the environment in pharmaceutical production during manufacturing operations with four solid and liquid nutrient media. These samples were then incubated under four different conditions suggested in the guidance documents. We believe that the results of our multicenter study confirming recent other single-site in situ studies could be the basis of the strategy to determine the best incubation regime for both viable environmental monitoring and aseptic process simulation in any manufacturing facility. © PDA, Inc. 2017.

Measurement of the optical and the physical properties of a liquid scintillator containing water at different times and under different environmental conditions

NASA Astrophysics Data System (ADS)

Kim, Seung Chan; Joo, Kyung Kwang; Kim, Ba Ro; Shin, Chang Dong; So, Sun Heang; Yeo, In Sung

2014-10-01

In this paper, we describe the optical and the physical properties of a liquid scintillator (LS) containing water with long-term stability. Gadolinium (Gd) is loaded into the liquid scintillator to increase the intensity of the neutron capture signal. If a successful neutrino experiment is to be performed, the Gd-loaded liquid scintillator (GdLS) must be stable over the entire duration of the experiment. If water is contained inside the GdLS, the optical and the physical parameters of the GdLS may change. We, therefore, briefly describe several characteristics of GdLS samples with various water contents under different environmental conditions. Measurements of the water content, Gd concentration, transmittance, and light yield (LY) were performed over 600 days.

Changes in the solid state of anhydrous and hydrated forms of sodium naproxen under different grinding and environmental conditions: Evidence of the formation of new hydrated forms.

PubMed

Censi, Roberta; Rascioni, Riccardo; Di Martino, Piera

2015-05-01

The aim of the present work was to investigate the solid state change of the anhydrous and hydrate solid forms of sodium naproxen under different grinding and environmental conditions. Grinding was carried out manually in a mortar under the following conditions: at room temperature under air atmosphere (Method A), in the presence of liquid nitrogen under air atmosphere (Method B), at room temperature under nitrogen atmosphere (Method C), and in the presence of liquid nitrogen under nitrogen atmosphere (Method D). Among the hydrates, the following forms were used: a dihydrate form (DSN) obtained by exposing the anhydrous form at 55% RH; a dihydrate form (CSN) obtained by crystallizing sodium naproxen from water; the tetrahydrate form (TSN) obtained by exposing the anhydrous form at 75% RH. The metastable monohydrate form (MSN), previously described in the literature, was not used because of its high physical instability. The chemical stability during grinding was firstly assessed and proven by HPLC. Modification of the particle size and shape, and changes in the solid state under different grinding methods were evaluated by scanning electron microscopy, and X-ray powder diffractometry and thermogravimetry, respectively. The study demonstrated the strong influence of starting form, grinding and environmental conditions on particle size, shape and solid state of recovered sodium naproxen forms. In particular, it was demonstrated that in the absence of liquid nitrogen (Methods A and C), either at air or at nitrogen atmosphere, the monohydrate form (MSN) was obtained from any hydrates, meaning that these grinding conditions favored the dehydration of superior hydrates. The grinding process carried out in the presence of liquid nitrogen (Method B) led to further hydration of the starting materials: new hydrate forms were identified as one pentahydrate form and one hexahydrate form. The hydration was caused by the condensation of the atmospheric water on sodium naproxen particles by liquid nitrogen and by the grinding forces that created a close contact between water and drug. The simultaneous disruption of the crystals, occurring during grinding, and their close contact with water molecules promoted the conversion in higher hydrates. Under the Method D, it was possible to highlight a certain tendency to hydration probably due to a rearrangement of water already present into the hydrates, but results were substantially different from Method B. Thus, summarizing, the different SN forms behave differently under different grinding and environmental conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

[Effects of a short-term diet of precooked corn flour on the vaginal cycle, in rats placed in various conditions of environmental illumination].

PubMed

Lopez de Onate, R; Giammanco, S; Carollo, F; Ernandes, M; Paderni, M A

1989-03-01

The aim of this research is to study the effects of a diet almost devoid of tryptophan, which is given by a feeding with precooked yellow corn meal (corn mush), on the alterations of the estrous cycle of animals in several conditions of environmental lighting. Indeed, it is known that cerebral serotonin influences the releasing of LH and consequently the ovulation. The different types of environmental lighting are: 1) Natural (alternating Day-Night = L/D). 2) Continuous dark (D/D). 3) Continuous light by sodium steams (L/L sodium). 4) Continuous light by fluorescent neon tubes (L/L neon). The muricide behaviour is studied by comparison rat-mouse. The feeding with precooked yellow corn meal (diet lacking of tryptophan) unchains in the 100% of the observations the CEA (Constant Estrous Anovulatory), and significantly shrinks the estral cycle in the female Wistar Rat in several conditions of environmental lighting.

Assessment of Secondary School Students' Awareness, Knowledge and Attitudes to Environmental Pollution Issues in the Mining Regions of South Africa: Implications for Instruction and Learning

ERIC Educational Resources Information Center

Olufemi, Adejoke Christianah; Mji, Andile; Mukhola, Murembiwa S.

2016-01-01

In this paper, we compared the levels of awareness, knowledge and attitudes (AKA) about environmental pollution of secondary school students from two South African provinces. The purpose was to determine the levels of AKA between students living under different environmental conditions. These two groups were students from a coal-mining province…

Biodegradation of Perchlorate in Laboratory Reactors Under Different Environmental Conditions

DTIC Science & Technology

2010-07-01

California Office of Environmental Health Hazard Assessment (OEHHA) 2004). Massachusetts has proposed a regulatory standard of 2 µg/L (Massachusetts...perchlorate has been detected in some animal feed crops, dairy, and meat. Alfalfa, a beef cattle and dairy cow feed, tested at 109–555 µg/kg for samples...transported to the Engineer Research and Development Center (ERDC), Environmental Laboratory, Hazardous Waste Research Center, Vicksburg, MS. The

Predicting invertebrate assemblage composition from harvesting pressure and environmental characteristics on tropical reef flats

NASA Astrophysics Data System (ADS)

Jimenez, H.; Dumas, P.; Ponton, D.; Ferraris, J.

2012-03-01

Invertebrates represent an essential component of coral reef ecosystems; they are ecologically important and a major resource, but their assemblages remain largely unknown, particularly on Pacific islands. Understanding their distribution and building predictive models of community composition as a function of environmental variables therefore constitutes a key issue for resource management. The goal of this study was to define and classify the main environmental factors influencing tropical invertebrate distributions in New Caledonian reef flats and to test the resulting predictive model. Invertebrate assemblages were sampled by visual counting during 2 years and 2 seasons, then coupled to different environmental conditions (habitat composition, hydrodynamics and sediment characteristics) and harvesting status (MPA vs. non-MPA and islets vs. coastal flats). Environmental conditions were described by a principal component analysis (PCA), and contributing variables were selected. Permutational analysis of variance (PERMANOVA) was used to test the effects of different factors (status, flat, year and season) on the invertebrate assemblage composition. Multivariate regression trees (MRT) were then used to hierarchically classify the effects of environmental and harvesting variables. MRT model explained at least 60% of the variation in structure of invertebrate communities. Results highlighted the influence of status (MPA vs. non-MPA) and location (islet vs. coastal flat), followed by habitat composition, organic matter content, hydrodynamics and sampling year. Predicted assemblages defined by indicator families were very different for each environment-exploitation scenario and correctly matched a calibration data matrix. Predictions from MRT including both environmental variables and harvesting pressure can be useful for management of invertebrates in coral reef environments.

Short-term heart rate variability in asthmatic obese children: effect of exhaustive exercise and different humidity conditions.

PubMed

Rezvan, K; Dabidi Roshan, V; Mahmudi, S A

2015-11-01

Asthmatic obese children experience changes in functional capacity and autonomic control. Previous heart rate variability (HRV) studies were based on 24-hour recordings, little research has been conducted on the short-term HRV in asthmatic obese children, primarily during physical effort indifferent environmental humidity conditions. The aim of this study was to evaluate the effect of aerobic activity on short-term HRV in asthmatic obese children under two different environmental humidity conditions. Ten obese boys with mild asthma as experimental group and 15 obese healthy boys with the same conditions were involved as a control group. Protocol included progressive and exhaustive aerobic activities on a calibrated ergometer pedal bicycle in two various environmental humidity 35±5% and 65±5%. HRV was measured by PADSY MEDSET Holter monitoring device during three phases; pre-test, mid-test and post-test. Then, short-term HRV was assessed from calculation of the mean R-R interval measured on HRV at each phases. HRV significantly decreased at mid-test and post-test among asthmatic and health children. However, the aforesaid changes were significantly higher in the asthmatic than health children following. Moreover, decrease of short-term HRV was significantly greater in the 35±5% than 65±5% environmental humidity. Our findings suggest from the autonomic standpoint, asthmatic and non-asthmatic children respond differently to exhaustive exercise induced stress. Aerobic exercise at an environment with high humidity compared with the low humidity appears to have additional benefits on short-term HRV in that it enhances the parasympathetic and autonomic modulation of the heart in asthmatic obese children.

Morphological variation in Sarracenia purpurea (Sarraceniaceae): geographic, environmental, and taxonomic correlates.

PubMed

Ellison, Aaron M; Buckley, Hannah L; Miller, Thomas E; Gotelli, Nicholas J

2004-11-01

Geographic variation in morphology reflects phenotypic responses to environmental gradients and evolutionary history of populations and species and may indicate local or regional changes in environmental conditions. The pitcher plant (Sarracenia purpurea) illustrates these principles. At local scales, its morphology reflects nutrient availability. At points along its broad geographic range (from Florida to northern Canada) morphology has been used to distinguish subspecies and varieties, but there has been no detailed study of the continuum of morphological variation across this entire range. Patterns of morphological variation in S. purpurea were characterized as a function of climatic and environmental conditions at 39 sites spanning its range. Differences in pitcher size and shape were strongly correlated with temperature, annual precipitation, and availability of ammonium and calcium in peat pore water. Pitcher shape (lip width, mouth diameter, and pitcher width) in Florida panhandle populations differed significantly from pitcher shape of all other populations, even after accounting for environmental correlations. In contrast, the northern and southern subspecies of S. purpurea (the latter exclusive of the Florida panhandle populations) cannot be distinguished based on these morphological measurements alone. These results support a recent proposal that identifies the Florida populations as a distinct species, Sarracenia rosea.

Governance of agro-pesticide through private environmental and social standards in the global cut flower chain from Ethiopia.

PubMed

Mengistie, Belay T; Mol, Arthur P J; Oosterveer, Peter

2017-11-01

The international cut flower industry is strongly criticized because of its environmental impacts and unsafe working conditions. Increasing certification of cut flowers is used to improve the growers' environmental and social performance. But what is the impact of this private governance instrument on regulating the use of pesticides? This paper assesses the potential of private certification on governing the environmental and social problems from pesticide use along the global cut flower supply chain. We use detailed farm-level data to analyse the environmental and social impacts of flower certification in Ethiopia by comparing different national and international certification schemes. Our analysis does not show significant differences between these different private standards for most environmental and health and safety variables. The Ethiopian cut flower industry remains far from improving its sustainability performance through private certification. However, certification schemes may enable farmers to have access to international markets and keep up their reputation.

Comparison of survival patterns of northern and southern genotypes of the North American tick Ixodes scapularis (Acari: Ixodidae) under northern and southern conditions

USGS Publications Warehouse

Ginsberg, Howard S.; Rulison, Eric L.; Azevedo, Alexandra; Pang, Genevieve C.; Kuczaj, Isis M.; Tsao, Jean I.; LeBrun, Roger A.

2014-01-01

BackgroundSeveral investigators have reported genetic differences between northern and southern populations of Ixodes scapularis in North America, as well as differences in patterns of disease transmission. Ecological and behavioral correlates of these genetic differences, which might have implications for disease transmission, have not been reported. We compared survival of northern with that of southern genotypes under both northern and southern environmental conditions in laboratory trials.MethodsSubadult I. scapularis from laboratory colonies that originated from adults collected from deer from several sites in the northeastern, north central, and southern U.S. were exposed to controlled conditions in environmental chambers. Northern and southern genotypes were exposed to light:dark and temperature conditions of northern and southern sites with controlled relative humidities, and mortality through time was recorded.ResultsTicks from different geographical locations differed in survival patterns, with larvae from Wisconsin surviving longer than larvae from Massachusetts, South Carolina or Georgia, when held under the same conditions. In another experiment, larvae from Florida survived longer than larvae from Michigan. Therefore, survival patterns of regional genotypes did not follow a simple north–south gradient. The most consistent result was that larvae from all locations generally survived longer under northern conditions than under southern conditions.ConclusionsOur results suggest that conditions in southern North America are less hospitable than in the north to populations of I. scapularis. Southern conditions might have resulted in ecological or behavioral adaptations that contribute to the relative rarity of I. scapularis borne diseases, such as Lyme borreliosis, in the southern compared to the northern United States.

Resources alter the structure and increase stochasticity in bromeliad microfauna communities.

PubMed

Petermann, Jana S; Kratina, Pavel; Marino, Nicholas A C; MacDonald, A Andrew M; Srivastava, Diane S

2015-01-01

Although stochastic and deterministic processes have been found to jointly shape structure of natural communities, the relative importance of both forces may vary across different environmental conditions and across levels of biological organization. We tested the effects of abiotic environmental conditions, altered trophic interactions and dispersal limitation on the structure of aquatic microfauna communities in Costa Rican tank bromeliads. Our approach combined natural gradients in environmental conditions with experimental manipulations of bottom-up interactions (resources), top-down interactions (predators) and dispersal at two spatial scales in the field. We found that resource addition strongly increased the abundance and reduced the richness of microfauna communities. Community composition shifted in a predictable way towards assemblages dominated by flagellates and ciliates but with lower abundance and richness of algae and amoebae. While all functional groups responded strongly and predictably to resource addition, similarity among communities at the species level decreased, suggesting a role of stochasticity in species-level assembly processes. Dispersal limitation did not affect the communities. Since our design excluded potential priority effects we can attribute the differences in community similarity to increased demographic stochasticity of resource-enriched communities related to erratic changes in population sizes of some species. In contrast to resources, predators and environmental conditions had negligible effects on community structure. Our results demonstrate that bromeliad microfauna communities are strongly controlled by bottom-up forces. They further suggest that the relative importance of stochasticity may change with productivity and with the organizational level at which communities are examined.

Resources Alter the Structure and Increase Stochasticity in Bromeliad Microfauna Communities

PubMed Central

Petermann, Jana S.; Kratina, Pavel; Marino, Nicholas A. C.; MacDonald, A. Andrew M.; Srivastava, Diane S.

2015-01-01

Although stochastic and deterministic processes have been found to jointly shape structure of natural communities, the relative importance of both forces may vary across different environmental conditions and across levels of biological organization. We tested the effects of abiotic environmental conditions, altered trophic interactions and dispersal limitation on the structure of aquatic microfauna communities in Costa Rican tank bromeliads. Our approach combined natural gradients in environmental conditions with experimental manipulations of bottom-up interactions (resources), top-down interactions (predators) and dispersal at two spatial scales in the field. We found that resource addition strongly increased the abundance and reduced the richness of microfauna communities. Community composition shifted in a predictable way towards assemblages dominated by flagellates and ciliates but with lower abundance and richness of algae and amoebae. While all functional groups responded strongly and predictably to resource addition, similarity among communities at the species level decreased, suggesting a role of stochasticity in species-level assembly processes. Dispersal limitation did not affect the communities. Since our design excluded potential priority effects we can attribute the differences in community similarity to increased demographic stochasticity of resource-enriched communities related to erratic changes in population sizes of some species. In contrast to resources, predators and environmental conditions had negligible effects on community structure. Our results demonstrate that bromeliad microfauna communities are strongly controlled by bottom-up forces. They further suggest that the relative importance of stochasticity may change with productivity and with the organizational level at which communities are examined. PMID:25775464

Skin parasitism by Paratrichosoma recurvum in wild American crocodiles and its relation to environmental and biological factors.

PubMed

Charruau, Pierre; Pérez-Flores, Jonathan S; Labarre, Didier

2017-01-24

Paratrichosma spp. are capillarid worms that parasitize the abdominal skin of crocodiles. They are likely not a threat to crocodiles' health, but they affect the skins' commercial value. No successful treatment exists against this parasite, and present knowledge of its life cycle is limited. Herein we report new information on Paratrichosoma recurvum occurrence in wild American crocodiles Crocodylus acutus from Mexican Caribbean islands and its relation to environmental (water salinity, temperature, climatic events) and biological (body condition) factors. The percentage of parasitized crocodiles (30.3%) is among the highest recorded in wild crocodilian populations. Small (<40.8 cm total length [TL]) and large (>270 cm TL) crocodiles are less parasitized, probably due to the characteristics of their skin or of the parasite life cycle. Two individuals appeared to have eliminated worms naturally between their capture and recapture. The thorax-abdomen is the most parasitized area of the body of crocodiles. The risk of infection is not associated with the sex of the crocodile, but there was a difference in the proportion of parasitized crocodiles between sites, which could be related to different environmental conditions. The body condition of a crocodile does not seem to be affected by the parasite. Climatic events and water temperature show no effect on the parasitism of crocodiles, but salinity could have an effect. The infection of crocodiles by P. recurvum could depend more on an individual's behavior than on environmental conditions.

High prevalence of multiple paternity in the invasive crayfish species, Procambarus clarkii

PubMed Central

Yue, Gen Hua; Li, Jia Le; Wang, Chun Ming; Xia, Jun Hong; Wang, Gen Lin; Feng, Jian Bing

2010-01-01

Reproductive strategy is a central feature of the ecology of invasive species as it determines the potential for population increase and range expansion. The red swamp crayfish, Procambarus clarkii, has invaded many countries and caused serious problems in freshwater ecosystems. However, little is known about the effects of environmental conditions on crayfish paternity and offspring traits in the wild. We studied these reproductive characteristics of P. clarkii in wild populations from two different habitats (ponds and ditches) in three locations with different environmental conditions in China. Genotyping of 1,436 offspring and 30 mothers of 30 broods was conducted by using four microsatellites. An analysis of genotyping results revealed that gravid females were the exclusive mother of the progeny they tended. Twenty-nine of 30 mothers had mated with multiple (2-4) males, each of which contributed differently to the number of offspring in a brood. The average number of fathers per brood and the number of offspring per brood were similar (P > 0.05) among six sampling sites, indicating that in P. clarkii multiple paternity and offspring number per brood are independent of environmental conditions studied. Indirect benefits from increasing the genetic diversity of broods, male and sperm competition, and cryptic female choice are a possible explanation for the high level multiple paternity and different contribution of fathers to offspring in this species. PMID:20186292

Effects of heritability, shared environment, and nonshared intrauterine conditions on child and adolescent BMI.

PubMed

Salsberry, Pamela J; Reagan, Patricia B

2010-09-01

Heritability studies of BMI, based upon twin samples, have identified genetic and shared environmental components of BMI, but have been largely silent about the nonshared environmental factors. Intrauterine factors have been identified as having significant long-term effects on BMI and may be a critical source of nonshared environmental influence. Extant studies based on samples of either unrelated individuals or twins cannot separate the effects of genetics, shared environments, and nonshared intrauterine conditions because the one lacks variation in the degree of relatedness and the other has insufficient variation in intrauterine conditions. This study improves upon these prior studies by using a large, sibling-based sample to examine heritability, shared environmental, and nonshared intrauterine influences on BMI during two age periods in childhood (6-8 years; 12-14 years). The primary interest was in determining the effects of the intrauterine environment on BMI as a component of the nonshared environment and in determining whether there were sex-specific differences in heritability and/or in the intrauterine factors. These were estimated using regression-based techniques introduced by DeFries and Fulker. Heritability of BMI was estimated to be 0.20-0.28 at 6-8 years and 0.46-0.61 at 12-14 years. Differences in heritability were found at 12-14 years between same-sex as compared to mixed-sex pairs. The shared environmental effect was significant at 6-8 years but insignificant at 12-14 years. Differences in birth weight were significant in all groups at 6-8 years suggesting long-term effects of the nonshared intrauterine environment; at 12-14 years, birth weight was no longer significant for girls.

Investigating the Control of Chlorophyll Degradation by Genomic Correlation Mining.

PubMed

Ghandchi, Frederick P; Caetano-Anolles, Gustavo; Clough, Steven J; Ort, Donald R

2016-01-01

Chlorophyll degradation is an intricate process that is critical in a variety of plant tissues at different times during the plant life cycle. Many of the photoactive chlorophyll degradation intermediates are exceptionally cytotoxic necessitating that the pathway be carefully coordinated and regulated. The primary regulatory step in the chlorophyll degradation pathway involves the enzyme pheophorbide a oxygenase (PAO), which oxidizes the chlorophyll intermediate pheophorbide a, that is eventually converted to non-fluorescent chlorophyll catabolites. There is evidence that PAO is differentially regulated across different environmental and developmental conditions with both transcriptional and post-transcriptional components, but the involved regulatory elements are uncertain or unknown. We hypothesized that transcription factors modulate PAO expression across different environmental conditions, such as cold and drought, as well as during developmental transitions to leaf senescence and maturation of green seeds. To test these hypotheses, several sets of Arabidopsis genomic and bioinformatic experiments were investigated and re-analyzed using computational approaches. PAO expression was compared across varied environmental conditions in the three separate datasets using regression modeling and correlation mining to identify gene elements co-expressed with PAO. Their functions were investigated as candidate upstream transcription factors or other regulatory elements that may regulate PAO expression. PAO transcript expression was found to be significantly up-regulated in warm conditions, during leaf senescence, and in drought conditions, and in all three conditions significantly positively correlated with expression of transcription factor Arabidopsis thaliana activating factor 1 (ATAF1), suggesting that ATAF1 is triggered in the plant response to these processes or abiotic stresses and in result up-regulates PAO expression. The proposed regulatory network includes the freezing, senescence, and drought stresses modulating factor ATAF1 and various other transcription factors and pathways, which in turn act to regulate chlorophyll degradation by up-regulating PAO expression.

Lipid-rich and protein-poor carbon allocation patterns of phytoplankton in the northern Chukchi Sea, 2011

NASA Astrophysics Data System (ADS)

Yun, Mi Sun; Joo, Hui Tae; Park, Jung Woo; Kang, Jae Joong; Kang, Sung-Ho; Lee, Sang H.

2018-04-01

The carbon allocations of phytoplankton into different photosynthetic end products (lipids, LMWM, polysaccharides, and proteins) were determined to understand physiological conditions of phytoplankton in the northern Chukchi Sea during the Korean Arctic expedition, 2011, using the 13C isotope tracer technique. The carbon allocation rates of lipids, LMWM, polysaccharides, and proteins were 0.00009-0.00062 h-1, 0.00001-0.00049 h-1, 0.00001-0.00025 h-1, and 0.00001-0.00062 h-1 within the euphotic depths from surface to 1% light depths during our cruise period, respectively. Significant relationships between protein production rates and chlorophyll a concentrations (large and total) were found in this study. Moreover, we found a significant negative relationship between lipid production rates and ammonium concentrations. These relationships match well with the previous results for environmental/physiological conditions for phytoplankton growth. Overall, phytoplankton allocated more photosynthetic carbon into lipids (42.5 ± 17.7%) whereas relatively lower to proteins (20.4 ± 15.5%) in this study. The lipid-rich and protein-poor allocation patterns in this study suggest that phytoplankton in the northern Chukchi Sea were in a stationary growth phase under nutrient deficient condition based on biological and environmental conditions observed during our study period. Based on comparison with the previous studies in the northern Bering Sea and southern Chukchi Sea, we found that the photosynthetic carbon allocation patterns depending on physiological status of phytoplankton under the different growth and/or nutrient conditions could be largely vary at different regions in the Arctic Ocean. More intensive research on the physiological status of phytoplankton is further required to determine how phytoplankton response to the changing environmental conditions and consequently how they impact on higher trophic levels in marine ecosystems in the Arctic Ocean.

VARIATION IN MORBIDITY AND MORTALITY OF MURINE TYPHUS INFECTION IN MICE WITH CHANGES IN THE ENVIRONMENTAL TEMPERATURE

PubMed Central

Moragues, Vicente; Pinkerton, Henry

1944-01-01

Murine typhus rickettsiae injected intraperitoneally in mice of the dba strain caused a uniformly fatal rickettsial peritonitis if the animals were kept at a room temperature ranging from 65–73°F. or from 70–80°F. With an environmental temperature range of 85–98°F., a mortality of less than 25 per cent was observed. By utilizing different strains of mice and controlling the environmental temperature, conditions may be created under which murine typhus will have any desired degree of mortality. Such conditions have obvious advantages for the evaluation of therapeutic measures in typhus infection. PMID:19871351

Measured and perceived environmental comfort: field monitoring in an Italian school.

PubMed

De Giuli, Valeria; Zecchin, Roberto; Corain, Livio; Salmaso, Luigi

2014-07-01

Microclimatic conditions were recorded in an Italian school and Fanger's indexes PMV and PPD were calculated under different conditions. Students' sensations were investigated four times by means of two surveys, one related to actual microclimatic conditions and one on overall satisfaction, interaction occupant-building and reactions to discomfort. Pupils' classroom position was considered to look for possible influence on thermal comfort: a difference emerged from PMV and the survey, but the results obtained from the two approaches differ for both the entity of discomfort and its distribution within each classroom. Innovative multivariate nonparametric statistical techniques were applied to compare and rank the classrooms in accordance with students' subjective perceptions; a global ranking has been also calculated, considering thermal and visual comfort and air quality. Comparing pupil-sensation-based ranking with environmental parameters no clear correspondence was found, except for mid-season, where PMV, CO2 concentration and desk illuminance were similar in all the classrooms. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

[Environmental approaches in the prevention of obesity in children and adolescents].

PubMed

Loss, J; Leitzmann, M

2011-03-01

This article aims to provide a structured review of how to create settings and environments that prevent the development of childhood overweight and obesity. It also describes which institutions and levels are responsible for environmental (global) approaches in obesity prevention and which evidence exists in terms of process and outcomes of different preventive measures. Environmental approaches in disease prevention deal with social and technical-material conditions of daily living, as those conditions significantly influence health behavior. Strategies that focus on the obesogenic environment are considered increasingly important in the prevention of obesity in children and adolescents. They can be applied at different levels (e.g., schools, communities). These interventions should aim to improve the availability of healthy foods and physical activity facilities, e.g., by provision of healthy meals and foods in schools, restaurants, and stores and by price reductions of healthy foods. Physical activity can be supported by creating attractive green spaces and playgrounds in schools and cities, improving sidewalk networks and a supportive pedestrian environment, and implementing walk-to-school projects. On a national level, policies and legislation can support changes in the social and situational environments, e.g., relating to catering in schools or TV advertisement. The practice of environmental approaches is complex, because many stakeholders from different sectors have to be involved. This may account for the observation that environmental approaches are currently underrepresented in obesity prevention.

Suitability of oyster restoration sites along the Louisiana coast: Examining site and stock × site interaction

USGS Publications Warehouse

Schwarting Miller, Lindsay; La Peyre, Jerome F.; LaPeyre, Megan K.

2017-01-01

Recognition of the global loss of subtidal oyster reefs has led to a rise in reef restoration efforts, including in the Gulf of Mexico. Created reef success depends entirely on selecting a location that supports long-term oyster growth and survival, including the recruitment and survival of on-reef oysters. Significant changes in estuarine salinity through management of freshwater inflows and through changed precipitation patterns may significantly impact the locations of optimal oyster restoration sites. These rapid shifts in conditions necessitate a need to better understand both impacts to on-reef oyster growth and population development, and variation in oyster stock performance. Oyster growth, mortality, condition, and disease prevalence were examined in three different stocks of oysters located in protected cages, as well as oyster recruitment and mortality on experimental reef units in three different locations representing a salinity gradient, along the Louisiana Gulf coast in 2011 and 2012. Over a 2-y period, the high-salinity site had highest oyster growth rate in protected cages but demonstrated the least likelihood for reef development based on on-reef oyster population failure, likely because of predation-related mortality (high recruitment and 100% mortality). In contrast, the midsalinity site with moderate oyster growth and on-reef recruitment and low mortality demonstrated a higher likelihood for reef development. The lowest salinity site exhibited extreme variability in all oyster responses between years because of extreme variation in environmental conditions during the study, indicating a low likelihood of long-term reef development. Whereas limited differences in stock performance between sites were found, the range of site environmental conditions tested was ultimately much lower than expected and may not have provided a wide enough range of conditions. In areas with limited, low recruitment, or rapidly changing environmental conditions, seeding with stocks selected for best growth and survival under expected future environmental conditions could better ensure reef development by using oyster populations best suited to the predicted conditions. With rapidly changing estuarine conditions from anthropogenic activities and climate change, siting of oyster reef restoration incorporating both oyster population dynamics and in situ biotic and abiotic interactions is critical in better directing site selection for reef restoration efforts.

Dynamic species classification of microorganisms across time, abiotic and biotic environments—A sliding window approach

PubMed Central

Griffiths, Jason I.; Fronhofer, Emanuel A.; Garnier, Aurélie; Seymour, Mathew; Altermatt, Florian; Petchey, Owen L.

2017-01-01

The development of video-based monitoring methods allows for rapid, dynamic and accurate monitoring of individuals or communities, compared to slower traditional methods, with far reaching ecological and evolutionary applications. Large amounts of data are generated using video-based methods, which can be effectively processed using machine learning (ML) algorithms into meaningful ecological information. ML uses user defined classes (e.g. species), derived from a subset (i.e. training data) of video-observed quantitative features (e.g. phenotypic variation), to infer classes in subsequent observations. However, phenotypic variation often changes due to environmental conditions, which may lead to poor classification, if environmentally induced variation in phenotypes is not accounted for. Here we describe a framework for classifying species under changing environmental conditions based on the random forest classification. A sliding window approach was developed that restricts temporal and environmentally conditions to improve the classification. We tested our approach by applying the classification framework to experimental data. The experiment used a set of six ciliate species to monitor changes in community structure and behavior over hundreds of generations, in dozens of species combinations and across a temperature gradient. Differences in biotic and abiotic conditions caused simplistic classification approaches to be unsuccessful. In contrast, the sliding window approach allowed classification to be highly successful, as phenotypic differences driven by environmental change, could be captured by the classifier. Importantly, classification using the random forest algorithm showed comparable success when validated against traditional, slower, manual identification. Our framework allows for reliable classification in dynamic environments, and may help to improve strategies for long-term monitoring of species in changing environments. Our classification pipeline can be applied in fields assessing species community dynamics, such as eco-toxicology, ecology and evolutionary ecology. PMID:28472193

Comparative metagenomic and metatranscriptomic analyses of microbial communities in acid mine drainage.

PubMed

Chen, Lin-xing; Hu, Min; Huang, Li-nan; Hua, Zheng-shuang; Kuang, Jia-liang; Li, Sheng-jin; Shu, Wen-sheng

2015-07-01

The microbial communities in acid mine drainage have been extensively studied to reveal their roles in acid generation and adaption to this environment. Lacking, however, are integrated community- and organism-wide comparative gene transcriptional analyses that could reveal the response and adaptation mechanisms of these extraordinary microorganisms to different environmental conditions. In this study, comparative metagenomics and metatranscriptomics were performed on microbial assemblages collected from four geochemically distinct acid mine drainage (AMD) sites. Taxonomic analysis uncovered unexpectedly high microbial biodiversity of these extremely acidophilic communities, and the abundant taxa of Acidithiobacillus, Leptospirillum and Acidiphilium exhibited high transcriptional activities. Community-wide comparative analyses clearly showed that the AMD microorganisms adapted to the different environmental conditions via regulating the expression of genes involved in multiple in situ functional activities, including low-pH adaptation, carbon, nitrogen and phosphate assimilation, energy generation, environmental stress resistance, and other functions. Organism-wide comparative analyses of the active taxa revealed environment-dependent gene transcriptional profiles, especially the distinct strategies used by Acidithiobacillus ferrivorans and Leptospirillum ferrodiazotrophum in nutrients assimilation and energy generation for survival under different conditions. Overall, these findings demonstrate that the gene transcriptional profiles of AMD microorganisms are closely related to the site physiochemical characteristics, providing clues into the microbial response and adaptation mechanisms in the oligotrophic, extremely acidic environments.

Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions

PubMed Central

Sun, Bo; Ye, Tianyuan; Feng, Qiang; Yao, Jinghua; Wei, Mumeng

2015-01-01

This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH)3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss), degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e., dissolved oxygen (DO) and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet. PMID:28793549

Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions.

PubMed

Sun, Bo; Ye, Tianyuan; Feng, Qiang; Yao, Jinghua; Wei, Mumeng

2015-09-10

This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu₂O film increased gradually. Its corrosion product was Cu₂(OH)₃Cl, which increased in quantity over time. Cl - was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss), degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e. , dissolved oxygen (DO) and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet.

Registered nurses' perceptions of conditions for patient education - focusing on organisational, environmental and professional cooperation aspects.

PubMed

Bergh, Anne-Louise; Karlsson, Jan; Persson, Eva; Friberg, Febe

2012-09-01

To describe nurses' perceptions of conditions for patient education, focusing on organisational, environmental and professional cooperation aspects, and to determine any differences between primary, municipal and hospital care. Although patient education is an important part of daily nursing practice, the conditions for this work are unclear and require clarification. A stratified random sample of 701 (83%) nurses working in primary, municipal and hospital care completed a 60-item questionnaire. The study is part of a larger project. The study items relating to organisation, environment and professional cooperation were analysed using descriptive statistics, non-parametric tests and content analysis. Conditions for patient education differ. Nurses in primary care had better conditions and more managerial support, for example in the allocation of undisturbed time. Conditions related to organisation, environment and cooperation need to be developed further. In this process, managerial support is important, and nurses must ask for better conditions in order to carry through patient education. Managerial support for the development of visible patient education routines (e.g. allocation of time, place and guidelines) is required. One recommendation is to designate a person to oversee educational work. © 2012 Blackwell Publishing Ltd.

Natural variation in germination responses of Arabidopsis to seasonal cues and their associated physiological mechanisms

PubMed Central

Barua, Deepak; Butler, Colleen; Tisdale, Tracy E.; Donohue, Kathleen

2012-01-01

Background and Aims Despite the intense interest in phenological adaptation to environmental change, the fundamental character of natural variation in germination is almost entirely unknown. Specifically, it is not known whether different genotypes within a species are germination specialists to particular conditions, nor is it known what physiological mechanisms of germination regulation vary in natural populations and how they are associated with responses to particular environmental factors. Methods We used a set of recombinant inbred genotypes of Arabidopsis thaliana, in which linkage disequilibrium has been disrupted over seven generations, to test for genetic variation and covariation in germination responses to distinct environmental factors. We then examined physiological mechanisms associated with those responses, including seed-coat permeability and sensitivity to the phytohormones gibberellic acid (GA) and abscisic acid (ABA). Key Results Genetic variation for germination was environment-dependent, but no evidence for specialization of germination to different conditions was found. Hormonal sensitivities also exhibited significant genetic variation, but seed-coat properties did not. GA sensitivity was associated with germination responses to multiple environmental factors, but seed-coat permeability and ABA sensitivity were associated with specific germination responses, suggesting that an evolutionary change in GA sensitivity could affect germination in multiple environments, but that of ABA sensitivity may affect germination under more restricted conditions. Conclusions The physiological mechanisms of germination responses to specific environmental factors therefore can influence the ability to adapt to diverse seasonal environments encountered during colonization of new habitats or with future predicted climate change. PMID:22012958

Women's Environmental Literacy As Social Capital In Environmental Management For Environmental Security of Urban Area

NASA Astrophysics Data System (ADS)

Asteria, Donna; Herdiansyah, Herdis; Wayan Agus Apriana, I.

2016-02-01

This study is about experience of women's role in environmental management to raise environmental security and form of women's emancipation movement. Environmental concerns conducted by residents of urban women who become environmental activists based on environmental literacy. Because of that, women's experience in interacting with both physic and social environment have differences in managing the environment including managing household waste by applying the principles of the 3Rs (reduce, reuse, recycle) and their persuasive efforts on their communities. This is the key to achieving sustainable development by anticipating environmental problem and preserving the environment. This study is conducted qualitative research method and its type is descriptive-explanative. The result of this study is environmental literacy of women activist on pro-environment action in their community that has achieved spiritual environmental literacy. Environmental literacy may differ due to internal and external condition of each individual. Pro-environment activities conducted as a form of responsibility of environmental concern such as eco-management, educational, and economic action, by persuading residents to proactively and consistently continue to do environmental management and develop a sense of community in shaping the networks of environmental concern in local context for global effect.

Endolithic microbial life in hot and cold deserts

NASA Technical Reports Server (NTRS)

Friedmann, E. I.

1980-01-01

Endolithic microorganisms (those living inside rocks) occur in hot and cold deserts and exist under extreme environmental conditions. These conditions are discussed on a comparative basis. Quantitative estimates of biomass are comparable in hot and cold deserts. Despite the obvious differences between the hot and cold desert environment, survival strategies show some common features. These endolithic organisms are able to 'switch' rapidly their metabolic activities on and off in response to changes in the environment. Conditions in hot deserts impose a more severe environmental stress on the organisms than in the cold Antarctic desert. This is reflected in the composition of the microbial flora which in hot desert rocks consist entirely of prokaryotic microorganisms, while under cold desert conditions eukaryotes predominate.

The effects of environmental resource and security on aggressive behavior.

PubMed

Ng, Henry Kin Shing; Chow, Tak Sang

2017-05-01

Exposure to different environments has been reported to change aggressive behavior, but previous research did not consider the underlying elements that caused such an effect. Based on previous work on environmental perception, we examined the role of environmental resource and security in altering aggression level. In three experiments, participants were exposed to environments that varied in resource (High vs. Low) and security (High vs. Low) levels, after which aggression was measured. The environments were presented through visual priming (Experiments 1-2) and a first-person gameplay (Experiment 3). We observed a consistent resource-security interaction effect on aggression, operationalized as the level of noise blast (Experiment 1) and number of unpleasant pictures (Experiments 2-3) delivered to strangers by the participants. High resource levels associated with higher aggression in insecure conditions, but lower aggression in secure conditions. The findings suggest that the adaptive value of aggression varies under different environmental constraints. Implications are discussed in terms of the effects of adverse environments on aggression, and the nature's effects on social behavior. Aggr. Behav. 43:304-314, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Environmental factors and habitat use influence body condition of individuals in a species at risk, the grizzly bear.

PubMed

Bourbonnais, Mathieu L; Nelson, Trisalyn A; Cattet, Marc R L; Darimont, Chris T; Stenhouse, Gordon B; Janz, David M

2014-01-01

Metrics used to quantify the condition or physiological states of individuals provide proactive mechanisms for understanding population dynamics in the context of environmental factors. Our study examined how anthropogenic disturbance, habitat characteristics and hair cortisol concentrations interpreted as a sex-specific indicator of potential habitat net-energy demand affect the body condition of grizzly bears (n = 163) in a threatened population in Alberta, Canada. We quantified environmental variables by modelling spatial patterns of individual habitat use based on global positioning system telemetry data. After controlling for gender, age and capture effects, we assessed the influence of biological and environmental variables on body condition using linear mixed-effects models in an information theoretical approach. Our strongest model suggested that body condition was improved when patterns of habitat use included greater vegetation productivity, increased influence of forest harvest blocks and oil and gas well sites, and a higher percentage of regenerating and coniferous forest. However, body condition was negatively affected by habitat use in close proximity to roads and in areas where potential energetic demands were high. Poor body condition was also associated with increased selection of parks and protected areas and greater seasonal vegetation productivity. Adult females, females with cubs-of-year, juvenile females and juvenile males were in poorer body condition compared with adult males, suggesting that intra-specific competition and differences in habitat use based on gender and age may influence body condition dynamics. Habitat net-energy demand also tended to be higher in areas used by females which, combined with observed trends in body condition, could affect reproductive success in this threatened population. Our results highlight the importance of considering spatiotemporal variability in environmental factors and habitat use when assessing the body condition of individuals. Long-term and large-scale monitoring of the physiological state of individuals provides a more comprehensive approach to support management and conservation of species at risk.

Growth reaction norms of domesticated, wild and hybrid Atlantic salmon families in response to differing social and physical environments

PubMed Central

2013-01-01

Background Directional selection for growth has resulted in the 9-10th generation of domesticated Atlantic salmon Salmo salar L. outgrowing wild salmon by a ratio of approximately 3:1 when reared under standard hatchery conditions. In the wild however, growth of domesticated and wild salmon is more similar, and seems to differ at the most by a ratio of 1.25:1. Comparative studies of quantitative traits in farmed and wild salmon are often performed by the use of common-garden experiments where salmon of all origins are reared together to avoid origin-specific environmental differences. As social interaction may influence growth, the large observed difference in growth between wild and domesticated salmon in the hatchery may not be entirely genetically based, but inflated by inter-strain competition. This study had two primary aims: (i) investigate the effect of social interaction and inter-strain competition in common-garden experiments, by comparing the relative growth of farmed, hybrid and wild salmon when reared together and separately; (ii) investigate the competitive balance between wild and farmed salmon by comparing their norm of reaction for survival and growth along an environmental gradient ranging from standard hatchery conditions to a semi-natural environment with restricted feed. Results The main results of this study, which are based upon the analysis of more than 6000 juvenile salmon, can be summarised as; (i) there was no difference in relative growth between wild and farmed salmon when reared together and separately; (ii) the relative difference in body weight at termination between wild and farmed salmon decreased as mortality increased along the environmental gradient approaching natural conditions. Conclusions This study demonstrates that potential social interactions between wild and farmed salmon when reared communally are not likely to cause an overestimation of the genetic growth differences between them. Therefore, common-garden experiments represent a valid methodological approach to investigate genetic differences between wild and farmed salmon. As growth of surviving salmon of all origins became more similar as mortality increased along the environmental gradient approaching natural conditions, a hypothesis is presented suggesting that size-selective mortality is a possible factor reducing growth differences between these groups in the wild. PMID:24165438

Effects of remediation on the bacterial community of an acid mine drainage impacted stream.

PubMed

Ghosh, Suchismita; Moitra, Moumita; Woolverton, Christopher J; Leff, Laura G

2012-11-01

Acid mine drainage (AMD) represents a global threat to water resources, and as such, remediation of AMD-impacted streams is a common practice. During this study, we examined bacterial community structure and environmental conditions in a low-order AMD-impacted stream before, during, and after remediation. Bacterial community structure was examined via polymerase chain reaction amplification of 16S rRNA genes followed by denaturing gradient gel electrophoresis. Also, bacterial abundance and physicochemical data (including metal concentrations) were collected and relationships to bacterial community structure were determined using BIO-ENV analysis. Remediation of the study stream altered environmental conditions, including pH and concentrations of some metals, and consequently, the bacterial community changed. However, remediation did not necessarily restore the stream to conditions found in the unimpacted reference stream; for example, bacterial abundances and concentrations of some elements, such as sulfur, magnesium, and manganese, were different in the remediated stream than in the reference stream. BIO-ENV analysis revealed that changes in pH and iron concentration, associated with remediation, primarily explained temporal alterations in bacterial community structure. Although the sites sampled in the remediated stream were in relatively close proximity to each other, spatial variation in community composition suggests that differences in local environmental conditions may have large impacts on the microbial assemblage.

Effects of environmental conditions associated to the cardinal orientation on the reproductive phenology of the cerrado savanna tree Xylopia aromatica (Annonaceae).

PubMed

Camargo, Maria Gabriela G; Souza, Regina M; Reys, Paula; Morellato, Leonor P C

2011-09-01

The Brazilian cerrado has undergone an intense process of fragmentation, which leads to an increase in the number of remnants exposed to edge effects and associated changes on environmental conditions that may affect the phenology of plants. This study aimed to verify whether the reproductive phenology of Xylopia aromatica (Lam.) Mart. (Annonaceae) differs under different light conditions in a cerrado sensu stricto (a woody savanna) of southeastern Brazil. We compared the reproductive phenology of X. aromatica trees distributed on east and south cardinal faces of the cerrado during monthly observations, from January 2005 to December 2008. The east face had a higher light incidence, higher temperatures and canopy openness in relation to south face. X. aromatica showed seasonal reproduction at both faces of the cerrado, but the percentage of individuals, the synchrony and duration of phenophases were higher at the east face. The study demonstrated the influence of the environmental conditions associated to the cardinal orientation of the cerrado faces on the phenological pattern of X. aromatica. Similar responses may be observed for other species, ultimately affecting patterns of floral visitation and fruit production, which reinforces the importance of considering the cardinal direction in studies of edge effects and fragmentation.

Developmental responses of bread wheat to changes in ambient temperature following deletion of a locus that includes FLOWERING LOCUS T1.

PubMed

Dixon, Laura E; Farré, Alba; Finnegan, E Jean; Orford, Simon; Griffiths, Simon; Boden, Scott A

2018-01-04

FLOWERING LOCUS T (FT) is a central integrator of environmental signals that regulates the timing of vegetative to reproductive transition in flowering plants. In model plants, these environmental signals have been shown to include photoperiod, vernalization, and ambient temperature pathways, and in crop species, the integration of the ambient temperature pathway remains less well understood. In hexaploid wheat, at least 5 FT-like genes have been identified, each with a copy on the A, B, and D genomes. Here, we report the characterization of FT-B1 through analysis of FT-B1 null and overexpression genotypes under different ambient temperature conditions. This analysis has identified that the FT-B1 alleles perform differently under diverse environmental conditions; most notably, the FT-B1 null produces an increase in spikelet and tiller number when grown at lower temperature conditions. Additionally, absence of FT-B1 facilitates more rapid germination under both light and dark conditions. These results provide an opportunity to understand the FT-dependent pathways that underpin key responses of wheat development to changes in ambient temperature. This is particularly important for wheat, for which development and grain productivity are sensitive to changes in temperature. © 2018 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd.

Environmental Growing Conditions in Five Production Systems Induce Stress Response and Affect Chemical Composition of Cocoa (Theobroma cacao L.) Beans.

PubMed

Niether, Wiebke; Smit, Inga; Armengot, Laura; Schneider, Monika; Gerold, Gerhard; Pawelzik, Elke

2017-11-29

Cocoa beans are produced all across the humid tropics under different environmental conditions provided by the region but also by the season and the type of production system. Agroforestry systems compared to monocultures buffer climate extremes and therefore provide a less stressful environment for the understory cocoa, especially under seasonally varying conditions. We measured the element concentration as well as abiotic stress indicators (polyamines and total phenolic content) in beans derived from five different production systems comparing monocultures and agroforestry systems and from two harvesting seasons. Concentrations of N, Mg, S, Fe, Mn, Na, and Zn were higher in beans produced in agroforestry systems with high stem density and leaf area index. In the dry season, the N, Fe, and Cu concentration of the beans increased. The total phenolic content increased with proceeding of the dry season while other abiotic stress indicators like spermine decreased, implying an effect of the water availability on the chemical composition of the beans. Agroforestry systems did not buffer the variability of stress indicators over the seasons compared to monocultures. The effect of environmental growing conditions on bean chemical composition was not strong but can contribute to variations in cocoa bean quality.

Environmental life cycle assessment of grain maize production: An analysis of factors causing variability.

PubMed

Boone, Lieselot; Van Linden, Veerle; De Meester, Steven; Vandecasteele, Bart; Muylle, Hilde; Roldán-Ruiz, Isabel; Nemecek, Thomas; Dewulf, Jo

2016-05-15

To meet the growing demand, high yielding, but environmentally sustainable agricultural plant production systems are desired. Today, life cycle assessment (LCA) is increasingly used to assess the environmental impact of these agricultural systems. However, the impact results are very diverse due to management decisions or local natural conditions. The impact of grain maize is often generalized and an average is taken. Therefore, we studied variation in production systems. Four types of drivers for variability are distinguished: policy, farm management, year-to-year weather variation and innovation. For each driver, scenarios are elaborated using ReCiPe and CEENE (Cumulative Exergy Extraction from the Natural Environment) to assess the environmental footprint. Policy limits fertilisation levels in a soil-specific way. The resource consumption is lower for non-sandy soils than for sandy soils, but entails however more eutrophication. Farm management seems to have less influence on the environmental impact when considering the CEENE only. But farm management choices such as fertiliser type have a large effect on emission-related problems (e.g. eutrophication and acidification). In contrast, year-to-year weather variation results in large differences in the environmental footprint. The difference in impact results between favourable and poor environmental conditions amounts to 19% and 17% in terms of resources and emissions respectively, and irrigation clearly is an unfavourable environmental process. The best environmental performance is obtained by innovation as plant breeding results in a steadily increasing yield over 25 years. Finally, a comparison is made between grain maize production in Flanders and a generically applied dataset, based on Swiss practices. These very different results endorse the importance of using local data to conduct LCA of plant production systems. The results of this study show decision makers and farmers how they can improve the environmental performance of agricultural systems, and LCA practitioners are alerted to challenges due to variation. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental Performance Report 2012: Annual Site Environmental Report per the U.S. Department of Energy Order 231.1-1B (Management Report)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This report presents a summary of NREL's environmental protection programs and activities for CY 2012. It is organized according to the different environmental media (e.g., air, waste, ground water, etc.), and includes a brief summary of how the program is managed in that area, any permitting or notification efforts that have been completed during the reporting period or are ongoing, and activities that have occurred during the reporting period in that environmental area. A description of the environmental condition and features of NREL's sites is also included to provide a basis for the program overview.

Comparative transcriptome analysis by RNAseq of necrotic enteritis Clostridium perfringens during in vivo colonization and in vitro conditions.

PubMed

Parreira, Valeria R; Russell, Kay; Athanasiadou, Spiridoula; Prescott, John F

2016-08-12

Necrotic enteritis (NE) caused by netB-positive type A Clostridium perfringens is an important bacterial disease of poultry. Through its complex regulatory system, C. perfringens orchestrates the expression of a collection of toxins and extracellular enzymes that are crucial for the development of the disease; environmental conditions play an important role in their regulation. In this study, and for the first time, global transcriptomic analysis was performed on ligated intestinal loops in chickens colonized with a netB-positive C. perfringens strain, as well as the same strain propagated in vitro under various nutritional and environmental conditions. Analysis of the respective pathogen transcriptomes revealed up to 673 genes that were significantly expressed in vivo. Gene expression profiles in vivo were most similar to those of C. perfringens grown in nutritionally-deprived conditions. Taken together, our results suggest a bacterial transcriptome responses to the early stages of adaptation, and colonization of, the chicken intestine. Our work also reveals how netB-positive C. perfringens reacts to different environmental conditions including those in the chicken intestine.

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

PubMed

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

2008-01-01

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

Association Between Cognitive Complaints and Vulnerability to Environmental Distraction in Multiple Sclerosis.

PubMed

Randolph, John J; Randolph, Jennifer S; Wishart, Heather A

2017-02-01

Individuals with multiple sclerosis (MS) often report cognitive dysfunction, although neuropsychological evaluation findings may not correlate with subjective concerns. One factor that may explain this lack of correspondence is the controlled testing environment, which differs from busier settings where cognitive lapses are noted to occur. This study used a novel environmental manipulation to determine whether individuals with MS who report cognitive dysfunction are more vulnerable to the effects of auditory distraction during neuropsychological testing. Twenty-four individuals with clinically definite MS or clinically isolated syndrome were administered a cognitive battery during two counterbalanced auditory conditions: quiet/standard condition, and distraction condition with random office background noise. Participants were divided into high versus low cognitive complaint groups using a median split analysis of Perceived Deficits Questionnaire responses. Participants with more cognitive complaints showed a decrement in performance on the oral Symbol Digit Modalities Test during the distraction condition while those with fewer cognitive complaints demonstrated stable performance across conditions. These findings remained significant after controlling for education, premorbid intellect, fatigue, and depressed mood. These results suggest that individuals with MS with more cognitive complaints are vulnerable to environmental distraction, particularly regarding processing speed. Incorporating random environmental noise or other distraction conditions during selected measures may enhance the ecological validity of neuropsychological evaluation results in MS. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Comparison of lysimeter based and calculated ASCE reference evapotranspiration in a subhumid climate

NASA Astrophysics Data System (ADS)

Nolz, Reinhard; Cepuder, Peter; Eitzinger, Josef

2016-04-01

The standardized form of the well-known FAO Penman-Monteith equation, published by the Environmental and Water Resources Institute of the American Society of Civil Engineers (ASCE-EWRI), is recommended as a standard procedure for calculating reference evapotranspiration (ET ref) and subsequently plant water requirements. Applied and validated under different climatic conditions it generally achieved good results compared to other methods. However, several studies documented deviations between measured and calculated reference evapotranspiration depending on environmental and weather conditions. Therefore, it seems generally advisable to evaluate the model under local environmental conditions. In this study, reference evapotranspiration was determined at a subhumid site in northeastern Austria from 2005 to 2010 using a large weighing lysimeter (ET lys). The measured data were compared with ET ref calculations. Daily values differed slightly during a year, at which ET ref was generally overestimated at small values, whereas it was rather underestimated when ET was large, which is supported also by other studies. In our case, advection of sensible heat proved to have an impact, but it could not explain the differences exclusively. Obviously, there were also other influences, such as seasonal varying surface resistance or albedo. Generally, the ASCE-EWRI equation for daily time steps performed best at average weather conditions. The outcomes should help to correctly interpret ET ref data in the region and in similar environments and improve knowledge on the dynamics of influencing factors causing deviations.

Exploring the linkage between spontaneous grass cover biodiversity and soil degradation in two olive orchard microcatchments with contrasting environmental and management conditions

NASA Astrophysics Data System (ADS)

Taguas, E. V.; Arroyo, C.; Lora, A.; Guzmán, G.; Vanderlinden, K.; Gómez, J. A.

2015-11-01

Spontaneous grass covers are an inexpensive soil erosion control measure in olive orchards. Olive farmers allow grass to grow on sloping terrain to comply with the basic environmental standards derived from the Common Agricultural Policy (CAP, European Commission). However, to date there are few studies assessing the environmental quality considering such covers. In this study, we measured biodiversity indices for spontaneous grass cover in two olive orchards with contrasting site conditions and management regimes in order to evaluate the potential for biodiversity metrics to serve as an indicator of soil degradation. In addition, the differences and temporal variability of biodiversity indicators and their relationships with environmental factors such as soil type and properties, precipitation, topography and soil management were analysed. Different grass cover biodiversity indices were evaluated in two olive orchard catchments under conventional tillage and no tillage with grass cover, during 3 hydrological years (2011-2013). Seasonal samples of vegetal material and photographs in a permanent grid (4 samples ha-1) were taken to characterize the temporal variations of the number of species, frequency of life forms, diversity and modified Shannon and Pielou indices. Sorensen's index showed strong differences in species composition for the grass covers in the two olive orchard catchments, which are probably linked to the different site conditions. The catchment (CN) with the best site conditions (deeper soil and higher precipitation) and most intense management presented the highest biodiversity indices as well as the highest soil losses (over 10 t ha-1). In absolute terms, the diversity indices of vegetation were reasonably high for agricultural systems in both catchments, despite the fact that management activities usually severely limit the landscape and the variety of species. Finally, a significantly higher content of organic matter in the first 10 cm of soil was found in the catchment with worse site conditions in terms of water deficit, average annual soil losses of 2 t ha-1 and the least intense management. Therefore, the biodiversity indices considered in this study to evaluate spontaneous grass cover were not found to be suitable for describing the soil degradation in the study catchments.

[Ethics and prevention: environmental and individual disparities].

PubMed

Ricciardi, Claudio

2004-01-01

The complex interactions which exist between environmental variabilities, genetic susceptibility of population subgroups, and high individual variability for age, sex, gender, ethnicity and general status of health, acquire an ever-increasing bioethical significance. Different risk conditions caused by toxic environmental agents and environmental inequities and inequalities are increasingly evident. "Social determinants" of health increase the probability of health effects and an effective intervention of prevision and prevention for environmental pathologies is needed. The debate on environmental inequalities caused by cultural, social and economic factors and the uncertainty about possible prevention emphasize the limits of the "bio-medical model". Ethics with its further anthropological and philosophical considerations may strongly help to understand the relationship between environmental pollution and health.

The Physiology of Adventitious Roots1

PubMed Central

Steffens, Bianka; Rasmussen, Amanda

2016-01-01

Adventitious roots are plant roots that form from any nonroot tissue and are produced both during normal development (crown roots on cereals and nodal roots on strawberry [Fragaria spp.]) and in response to stress conditions, such as flooding, nutrient deprivation, and wounding. They are important economically (for cuttings and food production), ecologically (environmental stress response), and for human existence (food production). To improve sustainable food production under environmentally extreme conditions, it is important to understand the adventitious root development of crops both in normal and stressed conditions. Therefore, understanding the regulation and physiology of adventitious root formation is critical for breeding programs. Recent work shows that different adventitious root types are regulated differently, and here, we propose clear definitions of these classes. We use three case studies to summarize the physiology of adventitious root development in response to flooding (case study 1), nutrient deficiency (case study 2), and wounding (case study 3). PMID:26697895

Quantifying the stability of trace explosives under different environmental conditions using electrospray ionization mass spectrometry.

PubMed

Sisco, Edward; Najarro, Marcela; Samarov, Daniel; Lawrence, Jeffrey

2017-04-01

This work investigates the stability of trace (tens of nanograms) deposits of six explosives: erythritol tetranitrate (ETN), pentaerythritol tetranitrate (PETN), cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranitramine (HMX), 2,4,6-trinitrotoluene (TNT), and 2,4,6-trinitrophenylmethylnitramine (tetryl) to determine environmental stabilities and lifetimes of trace level materials. Explosives were inkjet printed directly onto substrates and exposed to one of seven environmental conditions (Laboratory, -4°C, 30°C, 47°C, 90% relative humidity, UV light, and ozone) up to 42 days. Throughout the study, samples were extracted and quantified using electrospray ionization mass spectrometry (ESI-MS) to determine the stability of the explosive as a function of time and environmental exposure. Statistical models were then fit to the data and used for pairwise comparisons of the environments. Stability was found to be exposure and compound dependent with minimal sample losses observed for HMX, RDX, and PETN while substantial and rapid losses were observed in all conditions except -4°C for ETN and TNT and in all conditions for tetryl. The results of this work highlight the potential fate of explosive traces when exposed to various environments. Published by Elsevier B.V.

Quantifying the Stability of Trace Explosives under Different Environmental Conditions using Electrospray Ionization Mass Spectrometry

PubMed Central

Sisco, Edward; Najarro, Marcela; Samarov, Daniel; Lawrence, Jeffrey

2017-01-01

This work investigates the stability of trace (tens of nanograms) deposits of six explosives: erythritol tetranitrate (ETN), pentaerythritol tetranitrate (PETN), cyclotrimethylenetrinitramine (RDX), cyclotetramethylenetetranitramine (HMX), 2,4,6-trinitrotoluene (TNT), and 2,4,6-trinitrophenylmethylnitramine (tetryl) to determine environmental stabilities and lifetimes of trace level materials. Explosives were inkjet printed directly onto substrates and exposed to one of seven environmental conditions (Laboratory, −4 °C, 30 °C, 47 °C, 90 % relative humidity, UV light, and ozone) up to 42 days. Throughout the study, samples were extracted and quantified using electrospray ionization mass spectrometry (ESI-MS) to determine the stability of the explosive as a function of time and environmental exposure. Statistical models were then fit to the data and used for pairwise comparisons of the environments. Stability was found to be exposure and compound dependent with minimal sample losses observed for HMX, RDX, and PETN while substantial and rapid losses were observed in all conditions except −4 °C for ETN and TNT and in all conditions for tetryl. The results of this work highlight the potential fate of explosive traces when exposed to various environments. PMID:28153227

Genetic Background Has a Major Impact on Differences in Sleep Resulting from Environmental Influences in Drosophila

PubMed Central

Zimmerman, John E.; Chan, May T.; Jackson, Nicholas; Maislin, Greg; Pack, Allan I.

2012-01-01

Study Objectives: To determine the effect of different genetic backgrounds on demographic and environmental interventions that affect sleep and evaluate variance of these measures; and to evaluate sleep and variance of sleep behaviors in 6 divergent laboratory strains of common origin. Design: Assessment of the effects of age, sex, mating status, food sources, and social experience using video analysis of sleep behavior in 2 different strains of Drosophila, white1118ex (w1118ex) and white Canton-S (wCS10). Sleep was also determined for 6 laboratory strains of Canton-S and 3 inbred lines. The variance of total sleep was determined for all groups and conditions. Measurements and Results: The circadian periods and the effects of age upon sleep were the same between w1118ex and wCS10 strains. However, the w1118ex and wCS10 strains demonstrated genotype-dependent differences in the effects upon sleep of sex, mating status, social experience, and being on different foods. Variance of total sleep was found to differ in a genotype dependent manner for interventions between the w1118ex and wCS10 strains. Six different laboratory Canton-S strains were found to have significantly different circadian periods (P < 0.001) and sleep phenotypes (P < 0.001). Three inbred lines showed reduced variance for sleep measurements. Conclusions: One must control environmental conditions in a rigorously consistent manner to ensure that sleep data may be compared between experiments. Genetic background has a significant impact upon changes in sleep behavior and variance of behavior due to demographic factors and environmental interventions. This represents an opportunity to discover new genes that modify sleep/wake behavior. Citation: Zimmerman JE; Chan MT; Jackson N; Maislin G; Pack AI. Genetic background has a major impact on differences in sleep resulting from environmental influences in Drosophila. SLEEP 2012;35(4):545-557. PMID:22467993

Environmentally induced changes in correlated responses to selection reveal variable pleiotropy across a complex genetic network.

PubMed

Sikkink, Kristin L; Reynolds, Rose M; Cresko, William A; Phillips, Patrick C

2015-05-01

Selection in novel environments can lead to a coordinated evolutionary response across a suite of characters. Environmental conditions can also potentially induce changes in the genetic architecture of complex traits, which in turn could alter the pattern of the multivariate response to selection. We describe a factorial selection experiment using the nematode Caenorhabditis remanei in which two different stress-related phenotypes (heat and oxidative stress resistance) were selected under three different environmental conditions. The pattern of covariation in the evolutionary response between phenotypes or across environments differed depending on the environment in which selection occurred, including asymmetrical responses to selection in some cases. These results indicate that variation in pleiotropy across the stress response network is highly sensitive to the external environment. Our findings highlight the complexity of the interaction between genes and environment that influences the ability of organisms to acclimate to novel environments. They also make clear the need to identify the underlying genetic basis of genetic correlations in order understand how patterns of pleiotropy are distributed across complex genetic networks. © 2015 The Author(s).

ENVIRONMENTALLY INDUCED CHANGES IN CORRELATED RESPONSES TO SELECTION REVEAL VARIABLE PLEIOTROPY ACROSS A COMPLEX GENETIC NETWORK

PubMed Central

Sikkink, Kristin L.; Reynolds, Rose M.; Cresko, William A.; Phillips, Patrick C.

2017-01-01

Selection in novel environments can lead to a coordinated evolutionary response across a suite of characters. Environmental conditions can also potentially induce changes in the genetic architecture of complex traits, which in turn could alter the pattern of the multivariate response to selection. We describe a factorial selection experiment using the nematode Caenorhabditis remanei in which two different stress-related phenotypes (heat and oxidative stress resistance) were selected under three different environmental conditions. The pattern of covariation in the evolutionary response between phenotypes or across environments differed depending on the environment in which selection occurred, including asymmetrical responses to selection in some cases. These results indicate that variation in pleiotropy across the stress response network is highly sensitive to the external environment. Our findings highlight the complexity of the interaction between genes and environment that influences the ability of organisms to acclimate to novel environments. They also make clear the need to identify the underlying genetic basis of genetic correlations in order understand how patterns of pleiotropy are distributed across complex genetic networks. PMID:25809411

Size-dependent sex allocation in Aconitum gymnandrum (Ranunculaceae): physiological basis and effects of maternal family and environment.

PubMed

Zhao, Z-G; Meng, J-L; Fan, B-L; Du, G-Z

2008-11-01

Theory predicts size-dependent sex allocation (SDS): flowers on plants with a high-resource status should have larger investment in females than plants with a low-resource status. Through a pot experiment with Aconitum gymnandrum (Ranunculaceae) in the field, we examined the relationship between sex allocation of individual flowers and plant size for different maternal families under different environmental conditions. We also determined the physiological base of variations in plant size. Our results support the prediction of SDS, and show that female-biased allocation with plant size is consistent under different environmental conditions. Negative correlations within families showed a plastic response of sex allocation to plant size. Negative genetic correlations between sex allocation and plant size at the family level indicate a genetic cause of the SDS pattern, although genetic correlation was influenced by environmental factors. Hence, the size-dependency of sex allocation in this species had both plastic and genetic causes. Furthermore, genotypes that grew large also had higher assimilation ability, thus showing a physiological basis for SDS.

Environmental conditions affecting the efficiency and efficacy of piscicides for use in nonnative fish eradication

USGS Publications Warehouse

Brown, Peter James

2010-01-01

Conservation of native fish is a pressing issue for fisheries managers. Conservation efforts often require eliminating threats posed by nonnative fish by eradicating them with piscicides. The piscicides rotenone and antimycin are used for eradication but their application is often inefficient or ineffective. My goal was to increase the efficiency and efficacy of nonnative fish eradication using piscicides. I identified environmental conditions affecting piscicide application, researched methods to overcome these problems, and provided tools that piscicide applicators can use to make piscicide application more efficient and effective. Rotenone and antimycin were exposed to varying levels of sunlight, turbulence, and dissolved organic matter (DOM) to determine the effect these environmental conditions have on piscicides. Bioassay fish were used to determine the toxicity of the piscicides. Sunlight and turbulence affected rotenone and antimycin but DOM did not. Increasing the concentration of chemical can increase the resistance to the effects of these environmental conditions; however, the effects of these conditions are considerable in natural settings. Observations of bioassay fish in stream applications of rotenone were used to develop a statistical model to predict the persistence of the piscicide. The model can be used to predict rotenone persistence in small montane streams and to estimate where rotenone concentrations need to be fortified. I measured the mixing rate of a chemical plume in different channel morphologies and at center or edge applications. Center application had a significantly shorter mixing distance than edge application, but mixing distance was not different among meandering, straight, and riffle/pool morphologies. Application of my findings will increase the efficiency and efficacy of native fish conservation using piscicides.

Constitutional Epi/Genetic Conditions: Genetic, Epigenetic, and Environmental Factors

PubMed Central

Schenkel, Laila C.; Rodenhiser, David; Siu, Victoria; McCready, Elizabeth; Ainsworth, Peter; Sadikovic, Bekim

2016-01-01

There are more than 4,000 phenotypes for which the molecular basis is at least partly known. Though defects in primary DNA structure constitute a major cause of these disorders, epigenetic disruption is emerging as an important alternative mechanism in the etiology of a broad range of congenital and developmental conditions. These include epigenetic defects caused by either localized (in cis) genetic alterations or more distant (in trans) genetic events but can also include environmental effects. Emerging evidence suggests interplay between genetic and environmental factors in the epigenetic etiology of several constitutional “epi/genetic” conditions. This review summarizes our broadening understanding of how epigenetics contributes to pediatric disease by exploring different classes of epigenomic disorders. It further challenges the simplistic dogma of “DNA encodes RNA encodes protein” to best understand the spectrum of factors that can influence genetic traits in a pediatric population. PMID:28180025

Phenotypic plasticity in Drosophila cactophilic species: the effect of competition, density, and breeding sites.

PubMed

Fanara, Juan Jose; Werenkraut, Victoria

2017-08-01

Changes in the environmental conditions experienced by naturally occurring populations are frequently accompanied by changes in adaptive traits allowing the organism to cope with environmental unpredictability. Phenotypic plasticity is a major aspect of adaptation and it has been involved in population dynamics of interacting species. In this study, phenotypic plasticity (i.e., environmental sensitivity) of morphological adaptive traits were analyzed in the cactophilic species Drosophila buzzatii and Drosophila koepferae (Diptera: Drosophilidae) considering the effect of crowding conditions (low and high density), type of competition (intraspecific and interspecific competition) and cacti hosts (Opuntia and Columnar cacti). All traits (wing length, wing width, thorax length, wing loading and wing aspect) showed significant variation for each environmental factor considered in both Drosophila species. The phenotypic plasticity pattern observed for each trait was different within and between these cactophilic Drosophila species depending on the environmental factor analyzed suggesting that body size-related traits respond almost independently to environmental heterogeneity. The effects of ecological factors analyzed in this study are discussed in order to elucidate the causal factors investigated (type of competition, crowding conditions and alternative host) affecting the election of the breeding site and/or the range of distribution of these cactophilic species. © 2016 Institute of Zoology, Chinese Academy of Sciences.

Antecedent conditions influence soil respiration differences in shrub and grass patches

USDA-ARS?s Scientific Manuscript database

Quantifying the response of soil respiration to past environmental conditions is critical for predicting how future climate and vegetation change will impact ecosystem carbon balance. Increased shrub dominance in semiarid grasslands has potentially large effects on soil carbon cycling. The goal of t...

Individual differences in the forced swimming test and the effect of environmental enrichment: searching for an interaction.

PubMed

Sequeira-Cordero, A; Mora-Gallegos, A; Cuenca-Berger, P; Fornaguera-Trías, J

2014-04-18

Animals with low and high immobility in the forced swimming test (FST) differ in a number of neurobehavioral factors. A growing body of evidence suggests that the exposure to enriched environments mediates a number of changes in the brain. Therefore, we studied if animals' individuality can somehow modulate the response to environmental stimuli. Male rats were classified according to their immobility time scores in the FST test session as animals with low, medium or high immobility. Then, rats from groups with low and high immobility were randomly distributed in two groups to be reared in different housing conditions (i.e., enriched and standard conditions) during 8weeks. Animals were subjected to the open field test (OFT) before and 6weeks after the start of housing protocol. Rats with high immobility in the FST also showed high ambulation and high rearing time in the first OFT. Such findings were not observed in the second OFT. Conversely, an effect of environmental enrichment was found in the second OFT where enriched animals showed lower ambulation and higher grooming time than the standard control group. Rats were sacrificed after the housing protocol and neurochemical content and/or gene expression were studied in three different brain regions: the prefrontal cortex, the hippocampus and the nucleus accumbens. Rats with low immobility showed significantly higher accumbal 5-HT levels than animals with high immobility, whereas no neurochemical differences were observed between enriched and standard animals. Regarding expression data, however, an effect of enrichment on accumbal corticotropin-releasing factor (CRF) and its receptor 1 (CRFR1) levels was observed, and such effect depended on immobility levels. Thus, our results not only allowed us to identify a number of differences between animals with low and high immobility or animals housed in standard and enriched conditions, but also suggested that animals' individuality modulated in some way the response to environmental stimuli. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Effect of farm and simulated laboratory cold environmental conditions on the performance and physiological responses of lactating dairy cows supplemented with bovine somatotropin (BST)

NASA Astrophysics Data System (ADS)

Becker, B. A.; Johnson, H. D.; Li, R.; Collier, R. J.

1990-09-01

A study was conducted to evaluate the effect of bovine somatotropin (BST) supplementation in twelve lactating dairy cows maintained in cold environmental conditions. Six cows were injected daily with 25 mg of BST; the other six were injected with a control vehicle. Cows were maintained under standard dairy management during mid-winter for 30 days. Milk production was recorded twice daily, and blood samples were taken weekly. Animals were then transferred to environmentally controlled chambers and exposed to cycling thermoneutral (15° to 20° C) and cycling cold (-5° to +5° C) temperatures for 10 days in a split-reversal design. Milk production, feed and water intake, body weights and rectal temperatures were monitored. Blood samples were taken on days 1, 3, 5, 8 and 10 of each period and analyzed for plasma triiodothyronine (T3), thyroxine (T4), cortisol, insulin and prolactin. Under farm conditions, BST-treated cows produced 11% more milk than control-treated cows and in environmentally controlled chambers produced 17.4% more milk. No differences due to BST in feed or water intake, body weights or rectal temperatures were found under laboratory conditions. Plasma T3 and insulin increased due to BST treatment while no effect was found on cortisol, prolactin or T4. The results showed that the benefits of BST supplementation in lactating dairy cows were achieved under cold environmental conditions.

Estimation of flood environmental effects using flood zone mapping techniques in Halilrood Kerman, Iran.

PubMed

Boudaghpour, Siamak; Bagheri, Majid; Bagheri, Zahra

2014-01-01

High flood occurrences with large environmental damages have a growing trend in Iran. Dynamic movements of water during a flood cause different environmental damages in geographical areas with different characteristics such as topographic conditions. In general, environmental effects and damages caused by a flood in an area can be investigated from different points of view. The current essay is aiming at detecting environmental effects of flood occurrences in Halilrood catchment area of Kerman province in Iran using flood zone mapping techniques. The intended flood zone map was introduced in four steps. Steps 1 to 3 pave the way to calculate and estimate flood zone map in the understudy area while step 4 determines the estimation of environmental effects of flood occurrence. Based on our studies, wide range of accuracy for estimating the environmental effects of flood occurrence was introduced by using of flood zone mapping techniques. Moreover, it was identified that the existence of Jiroft dam in the study area can decrease flood zone from 260 hectares to 225 hectares and also it can decrease 20% of flood peak intensity. As a result, 14% of flood zone in the study area can be saved environmentally.

Mapping the ecological dimensions and potential distributions of endangered relic shrubs in western Ordos biodiversity center

PubMed Central

Zhu, Geng-Ping; Li, Hui-Qi; Zhao, Li; Man, Liang; Liu, Qiang

2016-01-01

Potential distributions of endemic relic shrubs in western Ordos were poorly mapped, which hindered our implementation of proper conservation. Here we investigated the applicability of ecological niche modeling for endangered relic shrubs to detect areas of priority for biodiversity conservation and analyze differences in ecological niche spaces used by relic shrubs. We applied ordination and niche modeling techniques to assess main environmental drivers of five endemic relic shrubs in western Ordos, namely, Ammopiptanthus mongolicus, Amygdalus mongolica, Helianthemum songaricum, Potaninia mongolica, and Tetraena mongolica. We calculated niche overlap metrics in gridded environmental spaces and compared geographical projections of ecological niches to determine similarities and differences of niches occupied by relic shrubs. All studied taxa presented different responses to environmental factors, which resulted in a unique combination of niche conditions. Precipitation availability and soil quality characteristics play important roles in the distributions of most shrubs. Each relic shrub is constrained by a unique set of environmental conditions, the distribution of one species cannot be implied by the distribution of another, highlighting the inadequacy of one-fits-all type of conservation measure. Our stacked habitat suitability maps revealed regions around Yellow River, which are highly suitable for most species, thereby providing high conservation value. PMID:27199260

Mapping the ecological dimensions and potential distributions of endangered relic shrubs in western Ordos biodiversity center.

PubMed

Zhu, Geng-Ping; Li, Hui-Qi; Zhao, Li; Man, Liang; Liu, Qiang

2016-05-20

Potential distributions of endemic relic shrubs in western Ordos were poorly mapped, which hindered our implementation of proper conservation. Here we investigated the applicability of ecological niche modeling for endangered relic shrubs to detect areas of priority for biodiversity conservation and analyze differences in ecological niche spaces used by relic shrubs. We applied ordination and niche modeling techniques to assess main environmental drivers of five endemic relic shrubs in western Ordos, namely, Ammopiptanthus mongolicus, Amygdalus mongolica, Helianthemum songaricum, Potaninia mongolica, and Tetraena mongolica. We calculated niche overlap metrics in gridded environmental spaces and compared geographical projections of ecological niches to determine similarities and differences of niches occupied by relic shrubs. All studied taxa presented different responses to environmental factors, which resulted in a unique combination of niche conditions. Precipitation availability and soil quality characteristics play important roles in the distributions of most shrubs. Each relic shrub is constrained by a unique set of environmental conditions, the distribution of one species cannot be implied by the distribution of another, highlighting the inadequacy of one-fits-all type of conservation measure. Our stacked habitat suitability maps revealed regions around Yellow River, which are highly suitable for most species, thereby providing high conservation value.

Integrated presentation of ecological risk from multiple stressors

PubMed Central

Goussen, Benoit; Price, Oliver R.; Rendal, Cecilie; Ashauer, Roman

2016-01-01

Current environmental risk assessments (ERA) do not account explicitly for ecological factors (e.g. species composition, temperature or food availability) and multiple stressors. Assessing mixtures of chemical and ecological stressors is needed as well as accounting for variability in environmental conditions and uncertainty of data and models. Here we propose a novel probabilistic ERA framework to overcome these limitations, which focusses on visualising assessment outcomes by construct-ing and interpreting prevalence plots as a quantitative prediction of risk. Key components include environmental scenarios that integrate exposure and ecology, and ecological modelling of relevant endpoints to assess the effect of a combination of stressors. Our illustrative results demonstrate the importance of regional differences in environmental conditions and the confounding interactions of stressors. Using this framework and prevalence plots provides a risk-based approach that combines risk assessment and risk management in a meaningful way and presents a truly mechanistic alternative to the threshold approach. Even whilst research continues to improve the underlying models and data, regulators and decision makers can already use the framework and prevalence plots. The integration of multiple stressors, environmental conditions and variability makes ERA more relevant and realistic. PMID:27782171

Variation in calcification rate of Acropora downingi relative to seasonal changes in environmental conditions in the northeastern Persian Gulf

NASA Astrophysics Data System (ADS)

Vajed Samiei, Jahangir; Saleh, Abolfazl; Shirvani, Arash; Sheijooni Fumani, Neda; Hashtroudi, Mehri; Pratchett, Morgan Stuart

2016-12-01

There is a strong interest in understanding how coral calcification varies with changing environmental conditions, especially given the projected changes in temperature and aragonite saturation due to climate change. This study explores in situ variation in calcification rates of Acropora downingi in the northeastern Persian Gulf relative to seasonal changes in temperature, irradiance and aragonite saturation state ( Ω arag). Calcification rates of A. downingi were highest in the spring and lowest in the winter, and intra-annual variation in calcification rate was significantly related to temperature ( r 2 = 0.30) and irradiance ( r 2 = 0.36), but not Ω arag ( r 2 = 0.02). Seasonal differences in temperature are obviously confounded by differences in other environmental conditions and vice versa. Therefore, we used published relationships from experimental studies to establish which environmental parameter(s) (temperature, irradiance, and/or Ω arag) placed greatest constraints on calcification rate (relative to the maximum spring rate) in each season. Variation in calcification rates was largely attributable to seasonal changes in irradiance and temperature (possibly 57.4 and 39.7% respectively). Therefore, we predict that ocean warming may lead to increased rates of calcification during winter, but decelerate calcification during spring, fall and especially summer, resulting in net deceleration of calcification for A. downingi in the Persian Gulf.

Past and future perspectives on mathematical models of tick-borne pathogens.

PubMed

Norman, R A; Worton, A J; Gilbert, L

2016-06-01

Ticks are vectors of pathogens which are important both with respect to human health and economically. They have a complex life cycle requiring several blood meals throughout their life. These blood meals take place on different individual hosts and potentially on different host species. Their life cycle is also dependent on environmental conditions such as the temperature and habitat type. Mathematical models have been used for the more than 30 years to help us understand how tick dynamics are dependent on these environmental factors and host availability. In this paper, we review models of tick dynamics and summarize the main results. This summary is split into two parts, one which looks at tick dynamics and one which looks at tick-borne pathogens. In general, the models of tick dynamics are used to determine when the peak in tick densities is likely to occur in the year and how that changes with environmental conditions. The models of tick-borne pathogens focus more on the conditions under which the pathogen can persist and how host population densities might be manipulated to control these pathogens. In the final section of the paper, we identify gaps in the current knowledge and future modelling approaches. These include spatial models linked to environmental information and Geographic Information System maps, and development of new modelling techniques which model tick densities per host more explicitly.

The influence of insecticide exposure and environmental stimuli on the movement behaviour and dispersal of a freshwater isopod.

PubMed

Augusiak, Jacqueline; Van den Brink, Paul J

2016-09-01

Behaviour links physiological function with ecological processes and can be very sensitive towards environmental stimuli and chemical exposure. As such, behavioural indicators of toxicity are well suited for assessing impacts of pesticides at sublethal concentrations found in the environment. Recent developments in video-tracking technologies offer the possibility of quantifying behavioural patterns, particularly locomotion, which in general has not been studied and understood very well for aquatic macroinvertebrates to date. In this study, we aim to determine the potential effects of exposure to two neurotoxic pesticides with different modes of action at different concentrations (chlorpyrifos and imidacloprid) on the locomotion behaviour of the water louse Asellus aquaticus. We compare the effects of the different exposure regimes on the behaviour of Asellus with the effects that the presence of food and shelter exhibit to estimate the ecological relevance of behavioural changes. We found that sublethal pesticide exposure reduced dispersal distances compared to controls, whereby exposure to chlorpyrifos affected not only animal activity but also step lengths while imidacloprid only slightly affected step lengths. The presence of natural cues such as food or shelter induced only minor changes in behaviour, which hardly translated to changes in dispersal potential. These findings illustrate that behaviour can serve as a sensitive endpoint in toxicity assessments. However, under natural conditions, depending on the exposure concentration, the actual impacts might be outweighed by environmental conditions that an organism is subjected to. It is, therefore, of importance that the assessment of toxicity on behaviour is done under relevant environmental conditions.

The FAO/NASA/NLR Artemis system - An integrated concept for environmental monitoring by satellite in support of food/feed security and desert locust surveillance

NASA Technical Reports Server (NTRS)

Hielkema, J. U.; Howard, J. A.; Tucker, C. J.; Van Ingen Schenau, H. A.

1987-01-01

The African real time environmental monitoring using imaging satellites (Artemis) system, which should monitor precipitation and vegetation conditions on a continental scale, is presented. The hardware and software characteristics of the system are illustrated and the Artemis databases are outlined. Plans for the system include the use of hourly digital Meteosat data and daily NOAA/AVHRR data to study environmental conditions. Planned mapping activities include monthly rainfall anomaly maps, normalized difference vegetation index maps for ten day and monthly periods with a spatial resolution of 7.6 km, ten day crop/rangeland moisture availability maps, and desert locust potential breeding activity factor maps for a plague prevention program.

Geographical scenario uncertainty in generic fate and exposure factors of toxic pollutants for life-cycle impact assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huijbregts, Mark A.J.; Lundi, Sven; McKone, Thomas E.

In environmental life-cycle assessments (LCA), fate and exposure factors account for the general fate and exposure properties of chemicals under generic environmental conditions by means of 'evaluative' multi-media fate and exposure box models. To assess the effect of using different generic environmental conditions, fate and exposure factors of chemicals emitted under typical conditions of (1) Western Europe, (2) Australia and (3) the United States of America were compared with the multi-media fate and exposure box model USES-LCA. Comparing the results of the three evaluative environments, it was found that the uncertainty in fate and exposure factors for ecosystems and humansmore » due to choice of an evaluative environment, as represented by the ratio of the 97.5th and 50th percentile, is between a factor 2 and 10. Particularly, fate and exposure factors of emissions causing effects in fresh water ecosystems and effects on human health have relatively high uncertainty. This uncertainty i s mainly caused by the continental difference in the average soil erosion rate, the dimensions of the fresh water and agricultural soil compartment, and the fraction of drinking water coming from ground water.« less

Impact of Leaching Conditions on Constituents Release from Flue Gas Desulfurization Gypsum (FGDG) and FGDG-Soil Mixture

EPA Science Inventory

The interest in using Flue Gas Desulfurization Gypsum(FGDG) has increased recently. This study evaluates the leaching characteristics of trace elements in "modern" FGDG (produced after fly ash removal) and FGDG-mixed soil (SF) under different environmental conditions using rece...

Counseling in the U.S.-Mexico Border Region.

ERIC Educational Resources Information Center

Russell, Todd T.; Madrigal, Julio F.

Residents of the U. S.-Mexico border region have the immense task of reconciling two different and often incompatible cultures, traditions, and languages. The cultural and environmental conditions of the South Texas border region are briefly described, and economic and social conditions are reviewed. The unique counseling needs of borderlanders of…

Assessment of Erysiphe necator ascospore release models for use in the Mediterranean climate of western Oregon

USDA-ARS?s Scientific Manuscript database

Predictive models have been developed in several major grape growing regions to correlate environmental conditions to Erysiphe necator ascospore release; however, these models may not accurately predict ascospore release in other viticulture regions with differing climatic conditions. To assess asco...

Degradation of the Herbicide Metolachlor in Drummer Soil Under Different Redox Conditions

USDA-ARS?s Scientific Manuscript database

Understanding the role of microorganisms and effect of soil environmental conditions on herbicide fate is critical for stewardship of herbicide use in cropping systems. As compared to the modernized perceptions of soil redox status, diminutive progress has been made in characterizing the impact of a...

Site-specific diel mercury emission fluxes in landfill: Combined effects of vegetation and meteorological factors.

PubMed

Liu, Yang; Wu, Boran; Hao, Yongxia; Zhu, Wei; Li, Zhonggen; Chai, Xiaoli

2017-01-01

Mercury emission fluxes (MEFs) under different surface coverage conditions in a landfill were investigated in this study. The results show similar diel patterns of Hg emission flux under different coverage conditions, with peak fluxes occurring at midday and decreasing during night. We examined the effects of environmental factors on MEFs, such as the physiological characteristics of vegetation and meteorological conditions. The results suggest that growth of vegetation in the daytime facilitates the release of Hg in the anaerobic unit, while in the semi-aerobic unit, where vegetation had been removed, the higher mercury content of the cover soil prompted the photo-reduction pathway to become the main path of mercury release and increased MEFs. MEFs are positively correlated with solar radiation and air temperature, but negatively correlated with relative humidity. The correlation coefficients for MEFs with different environmental parameters indicate that in the anaerobic unit, solar radiation was the main influence on MEFs in September, while air temperature became the main determining factor in December. These observations suggest that the effects of meteorological conditions on the mercury release mechanism varies depending on the vegetation and soil pathways. Copyright © 2016. Published by Elsevier Ltd.

Different features of work systems in Indonesia and their consequent approaches.

PubMed

Manuaba, A

1997-12-01

Indonesia, with its ultimate development goal of "developing the people and the community as a whole," in fact is facing problems in the execution of this goal. With a population of more than 200 million persons, different in sociocultural background, educational level and environmental conditions, it is understandable that the process and results of technological choices and transfers for various target groups will be different. A wide range of work systems is found, from the simplest man-tool system to the most complex. The conditions are becoming even more complex, a phenomenon especially evident through studies of their sociocultural, psychological, and environmental factors. As a consequence, if success is to be gained in anticipating and understanding the role of Indonesia in the global competition that lies ahead, a very wise approach to the situation by using local values that are often based on traditional habits and customs in a modern context should be carried out. This approach will require an immense amount of time, dedication and effort. Improvement endeavors that have been carried out in different work systems in different types of activities and industries, showed that if the improvement to be sustained, a holistic, systemic, and interdisciplined participatory approach should be taken into consideration where the technical, economical, ergonomic, sociocultural, energy, and environmental factors will play significant roles.

Evaluation of the surface-water sampling design in the Western Lake Michigan Drainages in relation to environmental factors affecting water quality at base flow

USGS Publications Warehouse

Robertson, Dale M.

1998-01-01

The variability in water quality throughout the WMIC Study Unit during base-flow conditions could be described very well by subdividing the area into Relatively Homogeneous Units and sampling a few streams with drainage basins completely within these homogeneous units. This subdivision and sampling scheme enabled the differences in water quality to be directly related to the differences in the environmental characteristics that exist throughout the Study Unit.

Environmental impact of exhaust emissions by Arctic shipping.

PubMed

Schröder, Christian; Reimer, Nils; Jochmann, Peter

2017-12-01

Since 2005, a dramatic decline of the Arctic sea-ice extent is observed which results in an increase of shipping activities. Even though this provides commercial and social development opportunities, the resulting environmental impacts need to be investigated and monitored. In order to understand the impact of shipping in arctic areas, the method described in this paper determines the travel time, fuel consumption and resulting exhaust emissions of ships navigating in arctic waters. The investigated case studies are considering ship particulars as well as environmental conditions with special focus on ice scenarios. Travel time, fuel consumption and exhaust gas emission were investigated for three different vessels, using different passages of the Northern Sea Route (NSR) in different seasons of years 1960, 2000 and 2040. The presented results show the sensitivity of vessel performance and amount of exhaust emissions to optimize arctic traffic with respect to efficiency, safety and environmental impact.

Mycobacterium ulcerans dynamics in aquatic ecosystems are driven by a complex interplay of abiotic and biotic factors

PubMed Central

Garchitorena, Andrés; Guégan, Jean-François; Léger, Lucas; Eyangoh, Sara; Marsollier, Laurent; Roche, Benjamin

2015-01-01

Host–parasite interactions are often embedded within complex host communities and can be influenced by a variety of environmental factors, such as seasonal variations in climate or abiotic conditions in water and soil, which confounds our understanding of the main drivers of many multi-host pathogens. Here, we take advantage of a combination of large environmental data sets on Mycobacterium ulcerans (MU), an environmentally persistent microorganism associated to freshwater ecosystems and present in a large variety of aquatic hosts, to characterize abiotic and biotic factors driving the dynamics of this pathogen in two regions of Cameroon. We find that MU dynamics are largely driven by seasonal climatic factors and certain physico-chemical conditions in stagnant and slow-flowing ecosystems, with an important role of pH as limiting factor. Furthermore, water conditions can modify the effect of abundance and diversity of aquatic organisms on MU dynamics, which suggests a different contribution of two MU transmission routes for aquatic hosts (trophic vs environmental transmission) depending on local abiotic factors. DOI: http://dx.doi.org/10.7554/eLife.07616.001 PMID:26216042

Nestling immunocompetence and testosterone covary with brood size in a songbird.

PubMed Central

Naguib, Marc; Riebel, Katharina; Marzal, Alfonso; Gil, Diego

2004-01-01

The social and ecological conditions that individuals experience during early development have marked effects on their developmental trajectory. In songbirds, brood size is a key environmental factor affecting development, and experimental increases in brood size have been shown to have negative effects on growth, condition and fitness. Possible causes of decreased growth in chicks from enlarged broods are nutritional stress, crowding and increased social competition, i.e. environmental factors known to affect adult steroid levels (especially of testosterone and corticosteroids) in mammals and birds. Little, however, is known about environmental effects on steroid synthesis in nestlings. We addressed this question by following the development of zebra finch (Taeniopygia guttata) chicks that were cross-fostered and raised in different brood sizes. In line with previous findings, nestling growth and cell-mediated immunocompetence were negatively affected by brood size. Moreover, nestling testosterone levels covaried with treatment: plasma testosterone increased with experimental brood size. This result provides experimental evidence that levels of circulating testosterone in nestlings can be influenced by their physiological response to environmental conditions. PMID:15255102

Platform of integrated tools to support environmental studies and management of dredging activities.

PubMed

Feola, Alessandra; Lisi, Iolanda; Salmeri, Andrea; Venti, Francesco; Pedroncini, Andrea; Gabellini, Massimo; Romano, Elena

2016-01-15

Dredging activities can cause environmental impacts due to, among other, the increase of the Suspended Solid Concentration (SSC) and their subsequent dispersion and deposition (DEP) far from the dredging point. The dynamics of the resulting dredging plume can strongly differ in spatial and temporal evolution. This evolution, for both conventional mechanical and hydraulic dredges, depends on the different mechanisms of sediment release in water column and the site-specific environmental conditions. Several numerical models are currently in use to simulate the dredging plume dynamics. Model results can be analysed to study dispersion and advection processes at different depths and distances from the dredging source. Usually, scenarios with frequent and extreme meteomarine conditions are chosen and extreme values of parameters (i.e. maximum intensity or total duration) are evaluated for environmental assessment. This paper presents a flexible, consistent and integrated methodological approach. Statistical parameters and indexes are derived from the analysis of SSC and DEP simulated time-series to numerically estimate their spatial (vertical and horizontal) and seasonal variability, thereby allowing a comparison of the effects of hydraulic and mechanical dredges. Events that exceed defined thresholds are described in term of magnitude, duration and frequency. A new integrated index combining these parameters, SSCnum, is proposed for environmental assessment. Maps representing the proposed parameters allow direct comparison of effects due to different (mechanical and hydraulic) dredges at progressive distances from the dredging zone. Results can contribute towards identification and assessment of the potential environmental effects of a proposed dredging project. A suitable evaluation of alternative technical choices, appropriate mitigation, management and monitoring measure is allowed in this framework. Environmental Risk Assessment and Decision Support Systems (DSS) may take advantage of the proposed tool. The approach is applied to a hypothetical dredging project in the Augusta Harbour (Eastern coast of Sicily Island-Italy). Copyright © 2015 Elsevier Ltd. All rights reserved.

The response of shoot accumulation of trace elements in Chinese cabbage to microclimate modification.

PubMed

Moreno, D A; Villora, M G; Hernández, J; Castilla, N; Romer, L

2001-01-01

In three consecutive years of field experiments (1994-96), three different environmental conditions for the growth of Chinese cabbage (Brassica pekinensis (Lour) Rupr. cv. Nagaoka 50) were established by using two cover treatments (T1 and T2) and a control uncovered cultivation (T0). The T1 [50 microm polyethylene cover; 20 degrees C air temperature; 61.9% relative moisture; 207 Wm(-2) irradiance] and T2 [a 17 gm(-2) non-woven fleece; 18 degrees C; 63.4%; 205 Wm(-2) gave rise to differences in environmental conditions with respect to T0 [14 degrees C; 57.5%; 237 Wm(-2)]. We analysed chloride (Cl), barium (Ba). rubidium (Rb) and tin (Sn) in the whole tops of experimental plants. Chloride removal was high for Brassica pekinensis but considerably lower for Rb, giving intermediate values for Ba and Sn. The influence of environmental factors under T1 increased trace-element removal and enhanced the usefulness for phytoremedation.

Environmental compatibility of closed landfills - assessing future pollution hazards.

PubMed

Laner, David; Fellner, Johann; Brunner, Paul H

2011-01-01

Municipal solid waste landfills need to be managed after closure. This so-called aftercare comprises the treatment and monitoring of residual emissions as well as the maintenance and control of landfill elements. The measures can be terminated when a landfill does not pose a threat to the environment any more. Consequently, the evaluation of landfill environmental compatibility includes an estimation of future pollution hazards as well as an assessment of the vulnerability of the affected environment. An approach to assess future emission rates is presented and discussed in view of long-term environmental compatibility. The suggested method consists (a) of a continuous model to predict emissions under the assumption of constant landfill conditions, and (b) different scenarios to evaluate the effects of changing conditions within and around the landfill. The model takes into account the actual status of the landfill, hence different methods to gain information about landfill characteristics have to be applied. Finally, assumptions, uncertainties, and limitations of the methodology are discussed, and the need for future research is outlined.

Exploring coral reef responses to millennial-scale climatic forcings: insights from the 1-D numerical tool pyReef-Core v1.0

NASA Astrophysics Data System (ADS)

Salles, Tristan; Pall, Jodie; Webster, Jody M.; Dechnik, Belinda

2018-06-01

Assemblages of corals characterise specific reef biozones and the environmental conditions that change spatially across a reef and with depth. Drill cores through fossil reefs record the time and depth distribution of assemblages, which captures a partial history of the vertical growth response of reefs to changing palaeoenvironmental conditions. The effects of environmental factors on reef growth are well understood on ecological timescales but are poorly constrained at centennial to geological timescales. pyReef-Core is a stratigraphic forward model designed to solve the problem of unobservable environmental processes controlling vertical reef development by simulating the physical, biological and sedimentological processes that determine vertical assemblage changes in drill cores. It models the stratigraphic development of coral reefs at centennial to millennial timescales under environmental forcing conditions including accommodation (relative sea-level upward growth), oceanic variability (flow speed, nutrients, pH and temperature), sediment input and tectonics. It also simulates competitive coral assemblage interactions using the generalised Lotka-Volterra system of equations (GLVEs) and can be used to infer the influence of environmental conditions on the zonation and vertical accretion and stratigraphic succession of coral assemblages over decadal timescales and greater. The tool can quantitatively test carbonate platform development under the influence of ecological and environmental processes and efficiently interpret vertical growth and karstification patterns observed in drill cores. We provide two realistic case studies illustrating the basic capabilities of the model and use it to reconstruct (1) the Holocene history (from 8500 years to present) of coral community responses to environmental changes and (2) the evolution of an idealised coral reef core since the last interglacial (from 140 000 years to present) under the influence of sea-level change, subsidence and karstification. We find that the model reproduces the details of the formation of existing coral reef stratigraphic sequences both in terms of assemblages succession, accretion rates and depositional thicknesses. It can be applied to estimate the impact of changing environmental conditions on growth rates and patterns under many different settings and initial conditions.

Is saltmarsh restoration success constrained by matching natural environments or altered succession? A test using niche models.

PubMed

Sullivan, Martin J P; Davy, Anthony J; Grant, Alastair; Mossman, Hannah L

2018-05-01

Restored habitats, such as saltmarsh created through managed realignment, sometimes fail to meet targets for biological equivalence with natural reference sites. Understanding why this happens is important in order to improve restoration outcomes.Elevation in the tidal frame and sediment redox potential are major controls on the distribution of saltmarsh plants. We use niche models to characterize 10 species' responses to these, and test whether differences in species occurrence between restored and natural saltmarshes in the UK result from failure to recreate adequate environmental conditions.Six species occurred less frequently in recently restored marshes than natural marshes. Failure of restored marshes to achieve the elevation and redox conditions of natural marshes partially explained the underrepresentation of five of these species, but did not explain patterns of occurrence on older (>50 years) restored marshes.For all species, an effect of marsh age remained after controlling for differences in environmental conditions. This could be due to differences in successional mechanism between restored and natural marshes. In recently restored marshes, high-marsh species occurred lower in the tidal frame and low-marsh species occurred higher in the tidal frame than in natural marshes. This supports the hypothesis that competition is initially weaker in restored marshes, because of the availability of bare sediment across the whole tidal frame. Species that establish outside their normal realized niche, such as Atriplex portulacoides , may inhibit subsequent colonization of other species that occurred less frequently than expected on older restored marshes. Synthesis and applications . Niche models can be used to test whether abiotic differences between restored sites and their natural counterparts are responsible for discrepancies in species occurrence. In saltmarshes, simply replicating environmental conditions will not result in equivalent species occurrence.

Electric signalling in fruit trees in response to water applications and light-darkness conditions.

PubMed

Gurovich, Luis A; Hermosilla, Paulo

2009-02-15

A fundamental property of all living organisms is the generation and conduction of electrochemical impulses throughout their different tissues and organs, resulting from abiotic and biotic changes in environmental conditions. In plants and animals, signal transmission can occur over long and short distances, and it can correspond to intra- and inter-cellular communication mechanisms that determine the physiological behaviour of the organism. Rapid plant and animal responses to environmental changes are associated with electrical excitability and signalling. The same molecules and pathways are used to drive physiological responses, which are characterized by movement (physical displacement) in animals and by continuous growth in plants. In the field of environmental plant electrophysiology, automatic and continuous measurements of electrical potential differences (DeltaEP) between plant tissues can be effectively used to study information transport mechanisms and physiological responses that result from external stimuli on plants. A critical mass of data on electrical behaviour in higher plants has accumulated in the last 5 years, establishing plant neurobiology as the most recent discipline of plant science. In this work, electrical potential differences were monitored continuously using Ag/AgCl microelectrodes, which were inserted 15mm deep into sapwood at various positions in the trunks of several fruit-bearing trees. Electrodes were referenced to an unpolarisable Ag/AgCl microelectrode, which was installed 5cm deep in the soil. Systematic patterns of DeltaEP during day-night cycles and at different conditions of soil water availability are discussed as alternative tools to assess early plant stress conditions. This research relates to the adaptive response of trees to soil water availability and light-darkness cycles.

Conditions in Home and Transplant Soils Have Differential Effects on the Performance of Diploid and Allotetraploid Anthericum Species

PubMed Central

Černá, Lucie; Münzbergová, Zuzana

2015-01-01

Due to increased levels of heterozygosity, polyploids are expected to have a greater ability to adapt to different environments than their diploid ancestors. While this theoretical pattern has been suggested repeatedly, studies comparing adaptability to changing conditions in diploids and polyploids are rare. The aim of the study was to determine the importance of environmental conditions of origin as well as target conditions on performance of two Anthericum species, allotetraploid A. liliago and diploid A. ramosum and to explore whether the two species differ in the ability to adapt to these environmental conditions. Specifically, we performed a common garden experiment using soil from 6 localities within the species’ natural range, and we simulated the forest and open environments in which they might occur. We compared the performance of diploid A. ramosum and allotetraploid A. liliago originating from different locations in the different soils. The performance of the two species was not affected by simulated shading but differed strongly between the different target soils. Growth of the tetraploids was not affected by the origin of the plants. In contrast, diploids from the most nutrient poor soil performed best in the richest soil, indicating that diploids from deprived environments have an increased ability to acquire nutrients when available. They are thus able to profit from transfer to novel nutrient rich environments. Therefore, the results of the study did not support the general expectation that the polyploids should have a greater ability than the diploids to adapt to a wide range of conditions. In contrast, the results are in line with the observation that diploids occupy a wider range of environments than the allotetraploids in our system. PMID:25607545

Roughness Versus Charge Contributions to Representative Discrete Heterogeneity Underlying Mechanistic Prediction of Colloid Attachment, Detachment and Breakthrough-Elution Behavior Under Environmental Conditions.

NASA Astrophysics Data System (ADS)

Johnson, William; Farnsworth, Anna; Vanness, Kurt; Hilpert, Markus

2017-04-01

The key element of a mechanistic theory to predict colloid attachment in porous media under environmental conditions where colloid-collector repulsion exists (unfavorable conditions for attachment) is representation of the nano-scale surface heterogeneity (herein called discrete heterogeneity) that drives colloid attachment under unfavorable conditions. The observed modes of colloid attachment under unfavorable conditions emerge from simulations that incorporate discrete heterogeneity. Quantitative prediction of attachment (and detachment) requires capturing the sizes, spatial frequencies, and other properties of roughness asperities and charge heterodomains in discrete heterogeneity representations of different surfaces. The fact that a given discrete heterogeneity representation will interact differently with different-sized colloids as well as different ionic strengths for a given sized colloid allows backing out representative discrete heterogeneity via comparison of simulations to experiments performed across a range of colloid size, solution IS, and fluid velocity. This has been achieved on unfavorable smooth surfaces yielding quantitative prediction of attachment, and qualitative prediction of detachment in response to ionic strength or flow perturbations. Extending this treatment to rough surfaces, and representing the contributions of nanoscale roughness as well as charge heterogeneity is a focus of this talk. Another focus of this talk is the upscaling the pore scale simulations to produce contrasting breakthrough-elution behaviors at the continuum (column) scale that are observed, for example, for different-sized colloids, or same-sized colloids under different ionic strength conditions. The outcome of mechanistic pore scale simulations incorporating discrete heterogeneity and subsequent upscaling is that temporal processes such as blocking and ripening will emerge organically from these simulations, since these processes fundamentally stem from the limited sites available for attachment as represented in discrete heterogeneity.

Research on the Test of Transmission Line Galloping

NASA Astrophysics Data System (ADS)

Zhang, Lichun; Li, Qing; lv, Zhongbin; Ji, Kunpeng; Liu, Bin

2018-03-01

The load of iced transmission line and the load generated by galloping after the conductor are covered by ice all may cause severe circuit faults, such as tripping, conductor breaking, armor clamp damage and even tower collapse, thus severely threatening running safety of power system. The generation and development processes of galloping of power transmission line is very complicated, and numerous factors may influence the galloping excitation, such as environmental factors, terrain factors and structural parameters of power transmission line; in which, the ice covering of conductor is one of necessary factors causing galloping. Therefore, researches on ice covering increasing test of different types of conductors under different meteorological conditions have been conducted in large-sized multi-functional phytotron, thus obtaining the relation curve of ice covering increasing of conductor along with time under different conditions, and analyzing factors influencing increasing of ice covering. The research result shows that under the same ice covering conditions, the increasing of ice covering of conductor with small diameter is relatively rapid; both environmental temperature and wind speed have obvious influence on increasing of ice covering of conductor, and the environmental temperature will decide the type of ice covering of conductor surface. Meanwhile, after wind tunnel tests targeting conductors with different ice covering shapes, pneumatic stability loss characteristics of conductors with different ice shapes have been obtained. Research results have important scientific reference value for revealing the mechanism of galloping of iced power transmission line, and have relatively high engineering practicability value for promoting realization of early warning system for galloping of iced power transmission line.

Effects of heat and moisture on fiberglass composite materials in the load carrying and non-load carrying conditions

NASA Astrophysics Data System (ADS)

McClurg, Jack Albert

The objective set forth in this study was to thoroughly document the effects of heat, moisture, and loading conditions on a variety of pultruded unidirectional fiberglass reinforced composite materials. This study incorporated the use of two environmental control chambers and two water immersion tanks in order to provide the necessary range of environmental exposure conditions. A set of specially designed stainless steel loading fixtures was produced in order to introduce the factor of external loading of the specimens while exposed to the predetermined environmental condition and how that would affect the mechanical and physical properties in question. The properties of interest were the flexural strength (determined using the three-point flexural bending method), flexural modulus (determined using the three-point flexural bending method), and glass transition temperature of the material (determined using differential scanning calorimetry). Other data that was noted during the conditioning and testing of the specimens was the break type (flexural tension, compression, shear, etc...), the change in dimensions (prior to exposure vs. after exposure), and the change in weight (prior to exposure vs. after exposure). Using all of the information that was obtained from this study, a more detailed understanding of how and why fiberglass reinforced materials react the way they do when exposed to moisture and elevated temperature was drawn. This study is different from most others in that it explores the interactions of three independent variables (heat, moisture, and loading condition) on three different fiberglass reinforced composite systems (epoxy, vinylester, and polyester resin).

Adsorption and degradation of five selected antibiotics in agricultural soil.

PubMed

Pan, Min; Chu, L M

2016-03-01

Large quantities of antibiotics are being added to agricultural fields worldwide through the application of wastewater, manures and biosolids, resulting in antibiotic contamination and elevated environmental risks in terrestrial environments. Most studies on the environmental fate of antibiotics focus on aquatic environments or wastewater treatment plants. Little is known about the behavior of antibiotics at environmentally relevant concentrations in agricultural soil. In this study we evaluated the adsorption and degradation of five different antibiotics (tetracycline, sulfamethazine, norfloxacin, erythromycin, and chloramphenicol) in sterilized and non-sterilized agricultural soils under aerobic and anaerobic conditions. Adsorption was highest for tetracycline (Kd, 1093 L/kg), while that for sulfamethazine was negligible (Kd, 1.365 L/kg). All five antibiotics were susceptible to microbial degradation under aerobic conditions, with half-lives ranging from 2.9 to 43.3 d in non-sterilized soil and 40.8 to 86.6 d in sterilized soil. Degradation occurred at a higher rate under aerobic conditions but was relatively persistent under anaerobic conditions. For all the antibiotics, a higher initial concentration was found to slow down degradation and prolong persistence in soil. The degradation behavior of the antibiotics varied in relation to their physicochemical properties as well as the microbial activities and aeration of the recipient soil. The poor adsorption and relative persistence of sulfamethazine under both aerobic and anaerobic conditions suggest that it may pose a higher risk to groundwater quality. An equation was proposed to predict the fate of antibiotics in soil under different field conditions, and assess their risks to the environment. Copyright © 2015 Elsevier B.V. All rights reserved.

The reverse environmental gender gap in China: evidence from "The China Survey".

PubMed

Shields, Todd; Zeng, Ka

2012-01-01

Objectives This article explores gender differences in attitudes about the seriousness of the environment as a problem in China using the “2008 China Survey.” Methods We use generalized ordered logit models to analyze survey respondents’ environmental attitudes. Results Our results indicate that there is indeed a “gender gap” in environmental attitudes in China, but the pattern is reversed from what has been generally found in previous work conducted in the United States and Europe. Chinese men, not women, show a greater concern about environmental problems and the seriousness of the environmental degradation in China. Further, we find that this gender gap is based largely in the substantial economic and educational differences between men and women in contemporary China. Conclusions This study emphasizes the mediating influence of socioeconomic variables in explaining gender attitudes toward the environment in China. Our findings suggest that in different contexts, women may be faced with difficult decisions between immediate economic necessities and long-term environmental concerns. The observed environmental gender gap in China will likely persist unless further economic development results in improved access to education and economic conditions for Chinese women.

Environmental enrichment alters dentate granule cell morphology in oldest-old rat.

PubMed

Darmopil, Sanja; Petanjek, Zdravko; Mohammed, Abdul H; Bogdanović, Nenad

2009-08-01

The hippocampus of aged rats shows marked age-related morphological changes that could cause memory deficits. Experimental evidence has established that environmental enrichment attenuates memory deficits in aged rats. We therefore studied whether environmental enrichment produces morphological changes on the dentate granule cells of aged rats. Fifteen male Sprague-Dawley rats, 24 months of age, were randomly distributed in two groups that were housed under standard (n = 7) or enriched (n = 8) environmental conditions for 26 days. Quantitative data of dendritic morphology from dentate gyrus granule cells were obtained on Golgi-Cox stained sections. Environmental enrichment significantly increased the complexity and size of dendritic tree (total number of segments increased by 61% and length by 116%), and spine density (88% increase). There were large interindividual differences within the enriched group, indicating differential individual responses to environmental stimulation. Previous studies in young animals have shown changes produced by environmental enrichment in the morphology of dentate gyrus granule cells. The results of the present study show that environmental enrichment can also produce changes in dentate granule cell morphology in the senescent brain. In conclusion, the hippocampus retains its neuroplastic capacity during aging, and enriched environmental housing conditions can attenuate age-related dendritic regression and synaptic loss, thus preserving memory functions.

The impact of background radiation, illumination and temperature on EMF-induced changes of aqua medium properties.

PubMed

Naira, Baghdasaryan; Yerazik, Mikayelyan; Anna, Nikoghosyan; Sinerik, Ayrapetyan

2013-09-01

The effects of extremely low frequency electromagnetic field (ELF EMF) on physicochemical properties of physiological solution at different environmental media were studied. The existence of frequency "windows" at 4 and 8 Hz frequencies of ELF EMF having effects on heat fusion period, hydrogen peroxide (H2O2) formation and oxygen (O2) content of water solution and different dependency on temperature, background radiation and illumination was shown. Obtained data allow us to suggest that EMF-induced effect on water physicochemical properties depends on abovementioned environmental factors. As cell bathing medium is a target for biological effects of ELF EMF, the variability of experimental data on biological effects of EMF, obtained in different laboratories, can be explained by different environmental conditions of experiments, which very often are not considered adequately.

Stationary Size Distributions of Growing Cells with Binary and Multiple Cell Division

NASA Astrophysics Data System (ADS)

Rading, M. M.; Engel, T. A.; Lipowsky, R.; Valleriani, A.

2011-10-01

Populations of unicellular organisms that grow under constant environmental conditions are considered theoretically. The size distribution of these cells is calculated analytically, both for the usual process of binary division, in which one mother cell produces always two daughter cells, and for the more complex process of multiple division, in which one mother cell can produce 2 n daughter cells with n=1,2,3,… . The latter mode of division is inspired by the unicellular algae Chlamydomonas reinhardtii. The uniform response of the whole population to different environmental conditions is encoded in the individual rates of growth and division of the cells. The analytical treatment of the problem is based on size-dependent rules for cell growth and stochastic transition processes for cell division. The comparison between binary and multiple division shows that these different division processes lead to qualitatively different results for the size distribution and the population growth rates.

Experimental determination of drift and PM10 cooling tower emissions: Influence of components and operating conditions.

PubMed

Ruiz, J; Kaiser, A S; Lucas, M

2017-11-01

Cooling tower emissions have become an increasingly common hazard to the environment (air polluting, ice formation and salts deposition) and to the health (Legionella disease) in the last decades. Several environmental policies have emerged in recent years limiting cooling tower emissions but they have not prevented an increasing intensity of outbreaks. Since the level of emissions depends mainly on cooling tower component design and the operating conditions, this paper deals with an experimental investigation of the amount of emissions, drift and PM 10 , emitted by a cooling tower with different configurations (drift eliminators and distribution systems) and working under several operating conditions. This objective is met by the measurement of cooling tower source emission parameters by means of the sensitive paper technique. Secondary objectives were to contextualize the observed emission rates according to international regulations. Our measurements showed that the drift rates included in the relevant international standards are significantly higher than the obtained results (an average of 100 times higher) and hence, the environmental problems may occur. Therefore, a revision of the standards is recommended with the aim of reducing the environmental and human health impact. By changing the operating conditions and the distribution system, emissions can be reduced by 52.03% and 82% on average. In the case of drift eliminators, the difference ranges from 18.18% to 98.43% on average. As the emissions level is clearly influenced by operating conditions and components, regulation tests should be referred to default conditions. Finally, guidelines to perform emission tests and a selection criterion of components and conditions for the tested cooling tower are proposed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Adolescent risk-taking under stressed and non-stressed conditions: Conservative, calculating and impulsive types

PubMed Central

Johnson, Sara B.; Dariotis, Jacinda K.; Wang, Constance

2012-01-01

Purpose Adolescent risk-taking may result from heightened susceptibility to environmental cues, particularly emotion and potential rewards. This study evaluated the impact of social stress on adolescent risk-taking, accounting for individual differences in risk-taking under non-stressed conditions. Methods Eighty-nine older adolescents completed a computerized risk-taking and decision-making battery at baseline. At follow-up, participants were randomized to a control condition, which repeated this battery, or an experimental condition, which included a social and cognitive stressor before the battery. Baseline risk-taking data were cluster-analyzed to create groups of adolescents with similar risk-taking tendencies. The degree to which these risk-taking tendencies predicted risk-taking by stress condition at follow-up was assessed. Results Participants in the stress condition took more risks those in the no-stress condition. However, differences in risk-taking under stress were related to baseline risk-taking tendencies. We observed three types of risk-takers: conservative, calculated, and impulsive. Impulsives were less accurate and planful under stress, calculated risk-takers took fewer risks, and conservatives engaged in low risk-taking regardless of stress. Conclusions As a group, adolescents are more likely to take risks in “hot cognitive” than in “cold cognitive” situations. However, there is significant variability in adolescents’ behavioral responses to stress related to trait-level risk-taking tendencies. Implications and contribution Many, but not all, adolescents take more risks under social stress. Parents and clinicians should be aware that behavior is a function of both personality and environmental cues. Interventions may help adolescents recognize their risk-taking propensity and environmental “triggers” that undermine their attempts to control their behavior. PMID:22794532

Linking Resilience of Aquatic Species to Watershed Condition

NASA Astrophysics Data System (ADS)

Flitcroft, R. L.

2017-12-01

Watershed condition means different things to different people. From the perspective of aquatic ecology, watershed condition may be interpreted to mean the capacity of a watershed to support life history diversity of native species. Diversity in expression of life history is thought to confer resilience allowing portions of the broader population to survive stressful conditions. Different species have different life history strategies, many of which were developed through adaptation to regional or local environmental conditions and natural disturbance regimes. By reviewing adaptation strategies for species of interest at regional scales, characteristics of watersheds that confer resilience may be determined. Such assessments must be completed at multiple levels of spatial organization (i.e. sub-watershed, watershed, region) allowing assessments to be inferred across broad spatial extents. In a project on the Wenatchee River watershed, we guided models of wildfire effects on bull trout and spring Chinook from a meta-population perspective to determine risks to survival at local and population scales over multiple extents of spatial organization. In other work in the Oregon Coast Range, we found that historic landslides continue to exert habitat-forming pressure at local scales, leading to patchiness in distribution of habitats for different life stages of coho salmon. Further, climate change work in Oregon estuaries identified different vulnerabilities in terms of juvenile rearing habitat depending on the species of interest and the intensity of future changes in climate. All of these studies point to the importance of considering physical conditions in watersheds at multiple spatial extents from the perspective of native aquatic species in order to understand risks to long-term survival. The broader implications of watershed condition, from this perspective, is the determination of physical attributes that confer resilience to native biota. This may require regionally specific metrics, and across-species synthesis of survival strategies and environmental conditions that confer resilience.

Evaluation of two evapotranspiration approaches simulated with the CSM-CERES-Maize model under different irrigation strategies and the impact on maize growth, development and soil moisture content for semi-arid conditions

USDA-ARS?s Scientific Manuscript database

Water deficit is the most common adverse environmental condition that can seriously reduce crop productivity. Crop simulation models could assist in determining alternate crop management scenarios to deal with water-limited conditions. However, prior to the application of crop models, the appropriat...

The Watcombe housing study: the short-term effect of improving housing conditions on the indoor environment.

PubMed

Richardson, George; Barton, Andrew; Basham, Meryl; Foy, Chris; Eick, Susan Ann; Somerville, Margaret

2006-05-15

A three-year study (1999-2001) was initiated in the UK to assess the effect of improving housing conditions in 3-4 bedroom, single-family unit, social rented sector houses on the health of the occupants. The houses were randomised into two groups. Phase I houses received extensive upgrading including wet central heating, on demand ventilation, double-glazed doors, cavity wall and roof/loft insulation. An identical intervention for Phase II houses was delayed for one year. As part of this randomised waiting list study, discrete measurements were made of indoor environmental variables in each house, to assess the short-term effects of improving housing conditions on the indoor environment. Variables representative of indoor environmental conditions were measured in the living room, bedroom and outdoors in each of the three years of the study. In 2000, there was a significant difference between the changes from 1999 to 2000 between Phase I (upgraded) and II (not then upgraded) houses for bedroom temperatures (p=0.002). Changes in wall surface dampness and wall dampness in Phase I houses were also significantly different to the change in Phase II houses in 2000 (p=0.001), but by 2001 the Phase I houses had reverted to the same dampness levels they had before upgrading. The housing upgrades increased bedroom temperatures in all houses. Other indoor environmental variables were not affected.

Re-evaluation of the sorption behaviour of Bromide and Sulfamethazine under field conditions using leaching data and modelling methods

NASA Astrophysics Data System (ADS)

Gassmann, Matthias; Olsson, Oliver; Höper, Heinrich; Hamscher, Gerd; Kümmerer, Klaus

2016-04-01

The simulation of reactive transport in the aquatic environment is hampered by the ambiguity of environmental fate process conceptualizations for a specific substance in the literature. Concepts are usually identified by experimental studies and inverse modelling under controlled lab conditions in order to reduce environmental uncertainties such as uncertain boundary conditions and input data. However, since environmental conditions affect substance behaviour, a re-evaluation might be necessary under environmental conditions which might, in turn, be affected by uncertainties. Using a combination of experimental data and simulations of the leaching behaviour of the veterinary antibiotic Sulfamethazine (SMZ; synonym: sulfadimidine) and the hydrological tracer Bromide (Br) in a field lysimeter, we re-evaluated the sorption concepts of both substances under uncertain field conditions. Sampling data of a field lysimeter experiment in which both substances were applied twice a year with manure and sampled at the bottom of two lysimeters during three subsequent years was used for model set-up and evaluation. The total amount of leached SMZ and Br were 22 μg and 129 mg, respectively. A reactive transport model was parameterized to the conditions of the two lysimeters filled with monoliths (depth 2 m, area 1 m²) of a sandy soil showing a low pH value under which Bromide is sorptive. We used different sorption concepts such as constant and organic-carbon dependent sorption coefficients and instantaneous and kinetic sorption equilibrium. Combining the sorption concepts resulted in four scenarios per substance with different equations for sorption equilibrium and sorption kinetics. The GLUE (Generalized Likelihood Uncertainty Estimation) method was applied to each scenario using parameter ranges found in experimental and modelling studies. The parameter spaces for each scenario were sampled using a Latin Hypercube method which was refined around local model efficiency maxima. Results of the cumulative SMZ leaching simulations suggest a best conceptualization combination of instantaneous sorption to organic carbon which is consistent with the literature. The best Nash-Sutcliffe efficiency (Neff) was 0.96 and the 5th and 95th percentile of the uncertainty estimation were 18 and 27 μg. In contrast, both scenarios of kinetic Br sorption had similar results (Neff =0.99, uncertainty bounds 110-176 mg and 112-176 mg) but were clearly better than instantaneous sorption scenarios. Therefore, only the concept of sorption kinetics could be identified for Br modelling whereas both tested sorption equilibrium coefficient concepts performed equally well. The reasons for this specific case of equifinality may be uncertainties of model input data under field conditions or an insensitivity of the sorption equilibrium method due to relatively low adsorption of Br. Our results show that it may be possible to identify or at least falsify specific sorption concepts under uncertain field conditions using a long-term leaching experiment and modelling methods. Cases of environmental fate concept equifinality arouse the possibility of future model structure uncertainty analysis using an ensemble of models with different environmental fate concepts.

Sleep patterns during rearing under different environmental conditions in juvenile rats.

PubMed

Mirmiran, M; van den Dungen, H; Uylings, H B

1982-02-11

Male Wistar rats were chronically implanted at weaning with electrodes for recording EEG amd EMG. From one month of age, they were randomly assigned to either 24 h or 2 h daily 'enriched' (EC), 'standard' (SC) or 'isolated' (IC) rearing conditions. The 24 h-EC group showed the following changes with respect to both the SC and the IC groups: (a) more quiet sleep time; (b) more active sleep time, and (c) shorter active sleep latency. These differences were evident by the third week of environmental conditioning, became statistically significant by 4 weeks, and continued to increase throughout the rest of the enrichment period. None of the sleep parameters showed any significant differences between the SC and the IC groups. The 2 h-EC rats showed an increase in both quiet sleep and active sleep time during the experimental period, whereas the controls showed the expected decline. Morphological investigations at 3 months of age revealed a significant weight increase in the cerebral cortex, and even more so in the hypothalamus as compared with the control group in the 2 h-EC rats.

The distribution of RNA polymerase in Escherichia coli is dynamic and sensitive to environmental cues | Center for Cancer Research

Cancer.gov

Despite extensive genetic, biochemical and structural studies on Escherichia coli RNA polymerase (RNAP), little is known about its location and distribution in response to environmental changes. To visualize the RNAP by fluorescence microscopy in E. coli under different physiological conditions, we constructed a functional rpoC-gfp gene fusion on the chromosome.

FTIR Determination of Pollutants in Automobile Exhaust: An Environmental Chemistry Experiment Comparing Cold-Start and Warm-Engine Conditions

ERIC Educational Resources Information Center

Medhurst, Laura L.

2005-01-01

An experiment developed from the Advanced Integrated Environmental Laboratory illustrates the differences in automobile exhaust before and after the engine is warmed, using gas-phase Fourier transform infrared spectroscopy (FTIR). The apparatus consists of an Avatar 360 FTIR spectrometer from Nicolet fitted with a variable path length gas cell,…

Environmental Scanning Project: A Dimensional Aspect of Needs Assessment in the Strategic Planning Process, Fall 1987.

ERIC Educational Resources Information Center

Lomax, Lynn A.

The environmental scanning project described in this report was undertaken at Lane Community College (LCC) in Eugene, Oregon, to enhance the college's strategic planning process by anticipating events that might differ from the economic, social, and political conditions of the present. First, an overview is provided of the purpose and intent of…

Hierarchical, parallel computing strategies using component object model for process modelling responses of forest plantations to interacting multiple stresses

Treesearch

J. G. Isebrands; G. E. Host; K. Lenz; G. Wu; H. W. Stech

2000-01-01

Process models are powerful research tools for assessing the effects of multiple environmental stresses on forest plantations. These models are driven by interacting environmental variables and often include genetic factors necessary for assessing forest plantation growth over a range of different site, climate, and silvicultural conditions. However, process models are...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilities access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

Genetic data from algae sedimentary DNA reflect the influence of environment over geography

PubMed Central

Stoof-Leichsenring, Kathleen R.; Herzschuh, Ulrike; Pestryakova, Luidmila A.; Klemm, Juliane; Epp, Laura S.; Tiedemann, Ralph

2015-01-01

Genetic investigations on eukaryotic plankton confirmed the existence of modern biogeographic patterns, but analyses of palaeoecological data exploring the temporal variability of these patterns have rarely been presented. Ancient sedimentary DNA proved suitable for investigations of past assemblage turnover in the course of environmental change, but genetic relatedness of the identified lineages has not yet been undertaken. Here, we investigate the relatedness of diatom lineages in Siberian lakes along environmental gradients (i.e. across treeline transects), over geographic distance and through time (i.e. the last 7000 years) using modern and ancient sedimentary DNA. Our results indicate that closely-related Staurosira lineages occur in similar environments and less-related lineages in dissimilar environments, in our case different vegetation and co-varying climatic and limnic variables across treeline transects. Thus our study reveals that environmental conditions rather than geographic distance is reflected by diatom-relatedness patterns in space and time. We tentatively speculate that the detected relatedness pattern in Staurosira across the treeline could be a result of adaptation to diverse environmental conditions across the arctic boreal treeline, however, a geographically-driven divergence and subsequent repopulation of ecologically different habitats might also be a potential explanation for the observed pattern. PMID:26261899

Genetic data from algae sedimentary DNA reflect the influence of environment over geography.

PubMed

Stoof-Leichsenring, Kathleen R; Herzschuh, Ulrike; Pestryakova, Luidmila A; Klemm, Juliane; Epp, Laura S; Tiedemann, Ralph

2015-08-11

Genetic investigations on eukaryotic plankton confirmed the existence of modern biogeographic patterns, but analyses of palaeoecological data exploring the temporal variability of these patterns have rarely been presented. Ancient sedimentary DNA proved suitable for investigations of past assemblage turnover in the course of environmental change, but genetic relatedness of the identified lineages has not yet been undertaken. Here, we investigate the relatedness of diatom lineages in Siberian lakes along environmental gradients (i.e. across treeline transects), over geographic distance and through time (i.e. the last 7000 years) using modern and ancient sedimentary DNA. Our results indicate that closely-related Staurosira lineages occur in similar environments and less-related lineages in dissimilar environments, in our case different vegetation and co-varying climatic and limnic variables across treeline transects. Thus our study reveals that environmental conditions rather than geographic distance is reflected by diatom-relatedness patterns in space and time. We tentatively speculate that the detected relatedness pattern in Staurosira across the treeline could be a result of adaptation to diverse environmental conditions across the arctic boreal treeline, however, a geographically-driven divergence and subsequent repopulation of ecologically different habitats might also be a potential explanation for the observed pattern.

Morphological changes in textile fibres exposed to environmental stresses: atomic force microscopic examination.

PubMed

Canetta, Elisabetta; Montiel, Kimberley; Adya, Ashok K

2009-10-30

The ability of the atomic force microscope (AFM) to investigate the nanoscopic morphological changes in the surfaces of fabrics was examined for the first time. This study focussed on two natural (cotton and wool), and a regenerated cellulose (viscose) textile fibres exposed to various environmental stresses for different lengths of times. Analyses of the AFM images allowed us to measure quantitatively the surface texture parameters of the environmentally stressed fabrics as a function of the exposure time. It was also possible to visualise at the nanoscale the finest details of the surfaces of three weathered fabrics and clearly distinguish between the detrimental effects of the imposed environmental conditions. This study confirmed that the AFM could become a very powerful tool in forensic examination of textile fibres to provide significant fibre evidence due to its capability of distinguishing between different environmental exposures or forced damages to fibres.

Effects of feed delivery frequency in different environmental conditions on time budget of lactating dairy cows.

PubMed

Mattachini, Gabriele; Bava, Luciana; Sandrucci, Anna; Tamburini, Alberto; Riva, Elisabetta; Provolo, Giorgio

2017-08-01

This study aimed to examine the influence of feed delivery frequency and environmental conditions on daily time budget of lactating dairy cows. The study was carried out in two commercial dairy farms with Holstein herds. Fifty lactating dairy cows milked in automatic milking units (AMS farm) and 96 primiparous lactating dairy cows milked in a conventional milking parlour (conventional farm) were exposed to different frequencies of feed delivery replicated in different periods of the year (warm and mild) that were characterized by different temperature-humidity indices (THI). On each farm, feeding treatments consisted of two different feed delivery frequencies (1× and 2× on the AMS farm; 2× and 3× on the conventional farm). All behaviours of the cows were monitored for the last 8 d of each treatment period using continuous video recording. The two data sets from different farm systems were considered separately for analysis. On both farms, environmental conditions expressed as THI affected time budgets and the pattern of the behavioural indices throughout the day. The variation in the frequency of feed delivery seems to affect the cow's time budget only in a limited way. Standing time of cows on the conventional farm and the time spent by cows in the milking waiting area on the AMS farm both increased in response to increased feeding frequency. Although feed delivery frequency showed limited influence on cow's time budget, the effect on standing time could be carefully considered, especially on farms equipped with AMS where the type of cow traffic system (e.g., milking first) might amplify the negative consequences of more frequent feed delivery. Further investigations are required to evaluate the effect of THI and feed delivery frequency on other aspects of behavioural activity.

Determining the drivers of population structure in a highly urbanized landscape to inform conservation planning.

PubMed

Thomassen, Henri A; Harrigan, Ryan J; Semple Delaney, Kathleen; Riley, Seth P D; Serieys, Laurel E K; Pease, Katherine; Wayne, Robert K; Smith, Thomas B

2018-02-01

Understanding the environmental contributors to population structure is of paramount importance for conservation in urbanized environments. We used spatially explicit models to determine genetic population structure under current and future environmental conditions across a highly fragmented, human-dominated environment in Southern California to assess the effects of natural ecological variation and urbanization. We focused on 7 common species with diverse habitat requirements, home-range sizes, and dispersal abilities. We quantified the relative roles of potential barriers, including natural environmental characteristics and an anthropogenic barrier created by a major highway, in shaping genetic variation. The ability to predict genetic variation in our models differed among species: 11-81% of intraspecific genetic variation was explained by environmental variables. Although an anthropogenically induced barrier (a major highway) severely restricted gene flow and movement at broad scales for some species, genetic variation seemed to be primarily driven by natural environmental heterogeneity at a local level. Our results show how assessing environmentally associated variation for multiple species under current and future climate conditions can help identify priority regions for maximizing population persistence under environmental change in urbanized regions. © 2017 Society for Conservation Biology.

Ecosystem classifications based on summer and winter conditions.

PubMed

Andrew, Margaret E; Nelson, Trisalyn A; Wulder, Michael A; Hobart, George W; Coops, Nicholas C; Farmer, Carson J Q

2013-04-01

Ecosystem classifications map an area into relatively homogenous units for environmental research, monitoring, and management. However, their effectiveness is rarely tested. Here, three classifications are (1) defined and characterized for Canada along summertime productivity (moderate-resolution imaging spectrometer fraction of absorbed photosynthetically active radiation) and wintertime snow conditions (special sensor microwave/imager snow water equivalent), independently and in combination, and (2) comparatively evaluated to determine the ability of each classification to represent the spatial and environmental patterns of alternative schemes, including the Canadian ecozone framework. All classifications depicted similar patterns across Canada, but detailed class distributions differed. Class spatial characteristics varied with environmental conditions within classifications, but were comparable between classifications. There was moderate correspondence between classifications. The strongest association was between productivity classes and ecozones. The classification along both productivity and snow balanced these two sets of variables, yielding intermediate levels of association in all pairwise comparisons. Despite relatively low spatial agreement between classifications, they successfully captured patterns of the environmental conditions underlying alternate schemes (e.g., snow classes explained variation in productivity and vice versa). The performance of ecosystem classifications and the relevance of their input variables depend on the environmental patterns and processes used for applications and evaluation. Productivity or snow regimes, as constructed here, may be desirable when summarizing patterns controlled by summer- or wintertime conditions, respectively, or of climate change responses. General purpose ecosystem classifications should include both sets of drivers. Classifications should be carefully, quantitatively, and comparatively evaluated relative to a particular application prior to their implementation as monitoring and assessment frameworks.

Infrared thermography in newborns: the first hour after birth.

PubMed

Christidis, Iris; Zotter, Heinz; Rosegger, Hellfried; Engele, Heidi; Kurz, Ronald; Kerbl, Reinhold

2003-01-01

It was the aim of this study to investigate the surface temperature in newborns within the first hour after delivery. Furthermore, the influence of different environmental conditions with regard to surface temperature was documented. Body surface temperature was recorded under several environmental conditions by use of infrared thermography. 42 newborns, all delivered at term and with weight appropriate for date, were investigated under controlled conditions. The surface temperature immediately after birth shows a uniform picture of the whole body; however, it is significantly lower than the core temperature. Soon after birth, peripheral sites become cooler whereas a constant temperature is maintained at the trunk. Bathing in warm water again leads to a more even temperature profile. Radiant heaters and skin-to-skin contact with the mother are both effective methods to prevent heat loss in neonates. Infrared thermography is a simple and reliable tool for the measurement of skin temperature profiles in neonates. Without the need of direct skin contact, it may be helpful for optimizing environmental conditions at delivery suites and neonatal intensive-care units. Copyright 2003 S. Karger AG, Basel

[Analysis and assessment of atmospheric pollution based on accumulation characterization of heavy metals in Platanus acerifolia leaves].

PubMed

Liu, Ling; Fang, Yan-Ming; Wang, Shun-Chang; Xie, Ying; Wang, Cheng-Run

2014-03-01

The present work was aimed to evaluate the heavy metal pollution in the atmosphere of Huainan City. We measured and clustered the accumulation of six heavy metals in Platanus acerifolia leaves in 20 sampling fields with six types of environmental conditions, and analyzed the EF value of heavy metal enrichment in the leaves. The results showed that the accumulations in Platanus acerifolia leaves varied according to different types of metals, following the order of Zn > Cu > Cr > Ni > Pb > Cd. Environmental conditions also had great influence on the accumulation of heavy metals. Cd and Cu were mostly found in cement plant and mine, respectively, and Cr, Ni, Pb and Zn were significant higher in main road, compared with other environmental conditions. The average values of EF for all the metals expect Cr in scenic and village area were over 1. The average values of EF for all the metals in mine, power plant, main road and cement plant were above 3. The overall pollution condition of heavy metals in Huainan City followed the order of Cd > Cu > Zn > Ni > Pb > Cr.

Variation in coastal Antarctic microbial community composition at sub-mesoscale: spatial distance or environmental filtering?

PubMed

Moreno-Pino, Mario; De la Iglesia, Rodrigo; Valdivia, Nelson; Henríquez-Castilo, Carlos; Galán, Alexander; Díez, Beatriz; Trefault, Nicole

2016-07-01

Spatial environmental heterogeneity influences diversity of organisms at different scales. Environmental filtering suggests that local environmental conditions provide habitat-specific scenarios for niche requirements, ultimately determining the composition of local communities. In this work, we analyze the spatial variation of microbial communities across environmental gradients of sea surface temperature, salinity and photosynthetically active radiation and spatial distance in Fildes Bay, King George Island, Antarctica. We hypothesize that environmental filters are the main control of the spatial variation of these communities. Thus, strong relationships between community composition and environmental variation and weak relationships between community composition and spatial distance are expected. Combining physical characterization of the water column, cell counts by flow cytometry, small ribosomal subunit genes fingerprinting and next generation sequencing, we contrast the abundance and composition of photosynthetic eukaryotes and heterotrophic bacterial local communities at a submesoscale. Our results indicate that the strength of the environmental controls differed markedly between eukaryotes and bacterial communities. Whereas eukaryotic photosynthetic assemblages responded weakly to environmental variability, bacteria respond promptly to fine-scale environmental changes in this polar marine system. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

LED lighting – modification of growth, metabolism, yield and flour composition in wheat by spectral quality and intensity

USDA-ARS?s Scientific Manuscript database

The use of light-emitting diode (LED) technology for plant cultivation under controlled environmental conditions can result in significant reductions in energy consumption. However, there is still a lack of detailed information on the lighting conditions required for optimal growth of different plan...

Considerations of Environmentally Relevant Test Conditions for Improved Evaluation of Ecological Hazards of Engineered Nanomaterials.

PubMed

Holden, Patricia A; Gardea-Torresdey, Jorge L; Klaessig, Fred; Turco, Ronald F; Mortimer, Monika; Hund-Rinke, Kerstin; Cohen Hubal, Elaine A; Avery, David; Barceló, Damià; Behra, Renata; Cohen, Yoram; Deydier-Stephan, Laurence; Ferguson, P Lee; Fernandes, Teresa F; Herr Harthorn, Barbara; Henderson, W Matthew; Hoke, Robert A; Hristozov, Danail; Johnston, John M; Kane, Agnes B; Kapustka, Larry; Keller, Arturo A; Lenihan, Hunter S; Lovell, Wess; Murphy, Catherine J; Nisbet, Roger M; Petersen, Elijah J; Salinas, Edward R; Scheringer, Martin; Sharma, Monita; Speed, David E; Sultan, Yasir; Westerhoff, Paul; White, Jason C; Wiesner, Mark R; Wong, Eva M; Xing, Baoshan; Steele Horan, Meghan; Godwin, Hilary A; Nel, André E

2016-06-21

Engineered nanomaterials (ENMs) are increasingly entering the environment with uncertain consequences including potential ecological effects. Various research communities view differently whether ecotoxicological testing of ENMs should be conducted using environmentally relevant concentrations-where observing outcomes is difficult-versus higher ENM doses, where responses are observable. What exposure conditions are typically used in assessing ENM hazards to populations? What conditions are used to test ecosystem-scale hazards? What is known regarding actual ENMs in the environment, via measurements or modeling simulations? How should exposure conditions, ENM transformation, dose, and body burden be used in interpreting biological and computational findings for assessing risks? These questions were addressed in the context of this critical review. As a result, three main recommendations emerged. First, researchers should improve ecotoxicology of ENMs by choosing test end points, duration, and study conditions-including ENM test concentrations-that align with realistic exposure scenarios. Second, testing should proceed via tiers with iterative feedback that informs experiments at other levels of biological organization. Finally, environmental realism in ENM hazard assessments should involve greater coordination among ENM quantitative analysts, exposure modelers, and ecotoxicologists, across government, industry, and academia.

Effects of different culture media on biodegradation of triclosan by Rhodotorula mucilaginosa and Penicillium sp.

PubMed

Ertit Taştan, Burcu; Özdemir, Caner; Tekinay, Turgay

Triclosan is an antimicrobial agent and a persistent pollutant. The biodegradation of triclosan is dependent on many variables including the biodegradation organism and the environmental conditions. Here, we evaluated the triclosan degradation potential of two fungi strains, Rhodotorula mucilaginosa and Penicillium sp., and the rate of its turnover to 2,4-dichlorophenol (2,4-DCP). Both of these strains showed less susceptibility to triclosan when grown in minimal salt medium. In order to further evaluate the effects of environmental conditions on triclosan degradation, three different culture conditions including original thermal power plant wastewater, T6 nutrimedia and ammonium mineral salts medium were used. The maximum triclosan degradation yield was 48% for R. mucilaginosa and 82% for Penicillium sp. at 2.7 mg/L triclosan concentration. Biodegradation experiments revealed that Penicillium sp. was more tolerant to triclosan. Scanning electron microscopy micrographs also showed the morphological changes of fungus when cells were treated with triclosan. Overall, these fungi strains could be used as effective microorganisms in active uptake (degradation) and passive uptake (sorption) of triclosan and their efficiency can be increased by optimizing the culture conditions.

Extinctions in ancient and modern seas.

PubMed

Harnik, Paul G; Lotze, Heike K; Anderson, Sean C; Finkel, Zoe V; Finnegan, Seth; Lindberg, David R; Liow, Lee Hsiang; Lockwood, Rowan; McClain, Craig R; McGuire, Jenny L; O'Dea, Aaron; Pandolfi, John M; Simpson, Carl; Tittensor, Derek P

2012-11-01

In the coming century, life in the ocean will be confronted with a suite of environmental conditions that have no analog in human history. Thus, there is an urgent need to determine which marine species will adapt and which will go extinct. Here, we review the growing literature on marine extinctions and extinction risk in the fossil, historical, and modern records to compare the patterns, drivers, and biological correlates of marine extinctions at different times in the past. Characterized by markedly different environmental states, some past periods share common features with predicted future scenarios. We highlight how the different records can be integrated to better understand and predict the impact of current and projected future environmental changes on extinction risk in the ocean. Copyright © 2012 Elsevier Ltd. All rights reserved.

A twin study of the genetics of fear conditioning.

PubMed

Hettema, John M; Annas, Peter; Neale, Michael C; Kendler, Kenneth S; Fredrikson, Mats

2003-07-01

Fear conditioning is a traditional model for the acquisition of fears and phobias. Studies of the genetic architecture of fear conditioning may inform gene-finding strategies for anxiety disorders. The objective of this study was to determine the genetic and environmental sources of individual differences in fear conditioning by means of a twin sample. Classic fear conditioning data were experimentally obtained from 173 same-sex twin pairs (90 monozygotic and 83 dizygotic). Sequences of evolutionary fear-relevant (snakes and spiders) and fear-irrelevant (circles and triangles) pictorial stimuli served as conditioned stimuli paired with a mild electric shock serving as the unconditioned stimulus. The outcome measure was the electrodermal skin conductance response. We applied structural equation modeling methods to the 3 conditioning phases of habituation, acquisition, and extinction to determine the extent to which genetic and environmental factors underlie individual variation in associative and nonassociative learning. All components of the fear conditioning process in humans demonstrated moderate heritability, in the range of 35% to 45%. Best-fitting multivariate models suggest that 2 sets of genes may underlie the trait of fear conditioning: one that most strongly affects nonassociative processes of habituation that also is shared with acquisition and extinction, and a second that appears related to associative fear conditioning processes. In addition, these data provide tentative evidence of differences in heritability based on the fear relevance of the stimuli. Genes represent a significant source of individual variation in the habituation, acquisition, and extinction of fears, and genetic effects specific to fear conditioning are involved.

Between and within laboratory reliability of mouse behaviour recorded in home-cage and open-field.

PubMed

Robinson, Lianne; Spruijt, Berry; Riedel, Gernot

2018-04-15

Reproducibility of behavioural findings between laboratories is difficult due to behaviour being sensitive to environmental factors and interactions with genetics. The objective of this study was to investigate reproducibility of behavioural data between laboratories using the PhenoTyper home cage observation system and within laboratory reproducibility using different lighting regimes. The ambulatory activity of C57BL/6 and DBA/2 mice was tested in PhenoTypers in two laboratories under near identical housing and testing conditions (Exp. 1). Additionally activity and anxiety were also assessed in the open-field test. Furthermore, testing in either a normal or inverted light/dark cycle was used to determine effects of lighting regime in a within-laboratory comparison in Aberdeen (Exp. 2). Using the PhenoTyper similar circadian rhythms were observed across laboratories. Higher levels of baseline and novelty-induced activity were evident in Aberdeen compared to Utrecht although strain differences were consistent between laboratories. Open field activity was also similar across laboratories whereas strain differences in anxiety were different. Within laboratory analysis of different lighting regimes revealed that behaviour of the mice was sensitive to changes in lighting. Utilisation of a home cage observation system facilitates the reproducibility of activity but not anxiety-related behaviours across laboratories by eliminating environmental factors known to influence reproducibility in standard behavioural tests. Standardisation of housing/test conditions resulted in reproducibility of home cage and open field activity but not anxiety-related phenotypes across laboratories with some behaviours more sensitive to environmental factors. Environmental factors include lighting and time of day. Copyright © 2017 Elsevier B.V. All rights reserved.

Flight response of slope-soaring birds to seasonal variation in thermal generation

Treesearch

Adam E. Duerr; Tricia A. Miller; Michael Lanzone; David Brandes; Jeff Cooper; Kieran O' Malley; Charles Maisonneuve; Junior A. Tremblay; Todd Katzner

2014-01-01

Animals respond to a variety of environmental cues, including weather conditions, when migrating. Understanding the relationship between weather and migration behaviour is vital to assessing time- and energy limitations of soaring birds. Different soaring modes have different efficiencies, are dependent upon different types of subsidized lift and are weather dependent...

The adaptive vehicle

DOT National Transportation Integrated Search

1986-10-08

The purpose of this study was to develop a concept for a vehicle which adapts its : performance to the preferences and capabilities of different drivers under a wide range of : driving and environmental conditions.

Adaptation responses of individuals to environmental changes in the ciliate Euplotes crassus

NASA Astrophysics Data System (ADS)

Kim, Se-Joo; Kim, Jin-Hyoung; Ju, Se-Jong

2017-03-01

Although the response unit of living organisms to environmental changes is at the individual level, most experiments on the adaptation responses of ciliates have been conducted in batches, comprising multiple-individuals, due to their microscopic size. However, here, we confirmed that individuals undergo different division cycles in monocultures of Euplotes crassus. They also exhibited transcript variations of 4.63-fold in SSU and of 22.78- fold in Hsp70. Additionally, in salt-stressed E. crassus individuals, SSU transcripts of individuals varied by 6.92-fold at 27 psu, 8.69- fold at 32 psu, and 2.51-fold at 37 psu. However, the maximum difference in Hsp70 was only 4.23-fold under all conditions. These results suggest there may be different biological rhythms even in siblings derived from the same parent. It can also be inferred that various environmental factors have different effects on different E. crassus individuals. Therefore, to elucidate relationships between organism adaptations and environmental changes, studies at the individual level should be conducted with multi-individual approaches.

Early experiences mediate distinct adult gene expression and reproductive programs in Caenorhabditis elegans

PubMed Central

Ow, Maria C.; Nichitean, Alexandra M.; Dorus, Steve; Hall, Sarah E.

2018-01-01

Environmental stress during early development in animals can have profound effects on adult phenotypes via programmed changes in gene expression. Using the nematode C. elegans, we demonstrated previously that adults retain a cellular memory of their developmental experience that is manifested by differences in gene expression and life history traits; however, the sophistication of this system in response to different environmental stresses, and how it dictates phenotypic plasticity in adults that contribute to increased fitness in response to distinct environmental challenges, was unknown. Using transcriptional profiling, we show here that C. elegans adults indeed retain distinct cellular memories of different environmental conditions. We identified approximately 500 genes in adults that entered dauer due to starvation that exhibit significant opposite (“seesaw”) transcriptional phenotypes compared to adults that entered dauer due to crowding, and are distinct from animals that bypassed dauer. Moreover, we show that two-thirds of the genes in the genome experience a 2-fold or greater seesaw trend in gene expression, and based upon the direction of change, are enriched in large, tightly linked regions on different chromosomes. Importantly, these transcriptional programs correspond to significant changes in brood size depending on the experienced stress. In addition, we demonstrate that while the observed seesaw gene expression changes occur in both somatic and germline tissue, only starvation-induced changes require a functional GLP-4 protein necessary for germline development, and both programs require the Argonaute CSR-1. Thus, our results suggest that signaling between the soma and the germ line can generate phenotypic plasticity as a result of early environmental experience, and likely contribute to increased fitness in adverse conditions and the evolution of the C. elegans genome. PMID:29447162

Influence of Potassium on Sapric Peat under Different Environmental Conditions

NASA Astrophysics Data System (ADS)

Tajuddin, Syafik Akmal Mohd; Rahman, Junita Abdul; Rahim, Nor Haakmal Abd; Saphira Radin Mohamed, Radin Maya; Saeed Abduh Algheethi, Adel Ali, Dr

2018-04-01

Potassium is mainly present in soil in the natural form known as the K-bearing mineral. Potassium is also available in fertilizer as a supplement to plants and can be categorized as macronutrient. The application of potassium improves the texture and structure of the soil beside to improves plant growth. The main objective of this study was to determine the concentration of potassium in sapric peat under different conditions. Physical model was used as a mechanism for the analysis of the experimental data using a soil column as an equipment to produce water leaching. In this investigation, there were four outlets in the soil column which were prepared from the top of the column to the bottom with the purpose of identifying the concentration of potassium for each soil level. The water leaching of each outlet was tested using atomic absorption spectroscopy (AAS). The results obtained showed that the highest concentrations of potassium for flush condition at outlet 4 was 13.58 ppm. Similarly, sapric under rainwater condition recorded the highest value of 13.32 and 12.34 ppm respectively at outlet 4 for wet and dry condition. However, the difference in Sapric, rainwater and fertilizer category showed that the highest value for the wet condition was achieved at outlet 2 with 13.99 ppm while highest value of 14.82 ppm was obtained for the dry condition at the outlet 3. It was concluded that the outlets in the soil column gave a detailed analysis of the concentration of potassium in the soil which was influenced by the environmental conditions.

Environmental and ecological changes associated with a marina.

PubMed

Rivero, Natalie K; Dafforn, Katherine A; Coleman, Melinda A; Johnston, Emma L

2013-01-01

Anthropogenic modifications to waterways are common and their ecological consequences must be understood to effectively conserve local biodiversity. The facilitation of recreational boating activities often requires substantial alteration of natural areas, however the environmental and ecological consequences of such alterations are rarely described in the scientific literature. In this study, ecological and physico-chemical conditions were investigated in a recreational boating marina, located inside a marine park on the south-east coast of Australia. Recruitment panels were deployed for 8 weeks both inside and outside the marina, and differences in the composition of the developing fouling communities were observed. The recruitment of taxa, which often have short-lived larvae, was increased inside the marina (bryozoans, spirorbids and sponges) while the recruitment of taxa, which often have longer-lived larvae, was reduced or absent (barnacles, solitary ascidians and non-spirorbid polychaetes). Differences were also observed in environmental conditions inside the marina cf. directly outside. The marina environment had higher turbidity, temperature and pH along with higher concentrations of lead and copper in suspended sediments, while flow rates and trapped sediment loads were reduced inside the marina. The differences observed in the study suggest that there may be marked environmental changes associated with marina developments. The potential ecological consequences of these changes should be a primary consideration during the planning process, particularly for developments in locations of notable ecological value.

Stochastic environmental fluctuations drive epidemiology in experimental host–parasite metapopulations

PubMed Central

Duncan, Alison B.; Gonzalez, Andrew; Kaltz, Oliver

2013-01-01

Environmental fluctuations are important for parasite spread and persistence. However, the effects of the spatial and temporal structure of environmental fluctuations on host–parasite dynamics are not well understood. Temporal fluctuations can be random but positively autocorrelated, such that the environment is similar to the recent past (red noise), or random and uncorrelated with the past (white noise). We imposed red or white temporal temperature fluctuations on experimental metapopulations of Paramecium caudatum, experiencing an epidemic of the bacterial parasite Holospora undulata. Metapopulations (two subpopulations linked by migration) experienced fluctuations between stressful (5°C) and permissive (23°C) conditions following red or white temporal sequences. Spatial variation in temperature fluctuations was implemented by exposing subpopulations to the same (synchronous temperatures) or different (asynchronous temperatures) temporal sequences. Red noise, compared with white noise, enhanced parasite persistence. Despite this, red noise coupled with asynchronous temperatures allowed infected host populations to maintain sizes equivalent to uninfected populations. It is likely that this occurs because subpopulations in permissive conditions rescue declining subpopulations in stressful conditions. We show how patterns of temporal and spatial environmental fluctuations can impact parasite spread and host population abundance. We conclude that accurate prediction of parasite epidemics may require realistic models of environmental noise. PMID:23966645

Mediterranean, invasive, woody species grow larger than their less-invasive counterparts under potential global environmental change.

PubMed

Erskine-Ogden, Jennifer; Grotkopp, Eva; Rejmánek, Marcel

2016-04-01

Revealing biological differences between invasive and noninvasive species is essential for predicting species' distribution changes with global environmental change. While most research has focused on differences between invasive and noninvasive species under favorable conditions using herbaceous species, invasive woody angiosperms are also of great ecological concern. Our study focused on how growth and allocation may change for invasive and noninvasive, mediterranean, woody angiosperms under future conditions caused by global change, specifically increased nitrogen deposition and drought. We tested how seedling functional traits differed between invasive and noninvasive woody angiosperms under different experimental conditions in a greenhouse setting. We compared growth rates and allocation patterns using two levels of soil nitrogen and three levels of watering. We also examined trait log response ratios to increases in nitrogen and increases in water. Our study sampled angiosperm trees and shrubs, incorporating congeneric/confamilial relationships through 13 phylogenetically controlled contrasts. Three functional traits were highly and positively associated with plant invasiveness for most conditions studied: seedling plant mass, leaf area, and height. Invasive species also had significantly higher root mass ratios at low water regardless of nitrogen input. Invasive and noninvasive species had similar log response ratios to increases in nitrogen and watering for studied traits. Mediterranean, woody, invasive species' larger mass, leaf area, and early height advantage under elevated nitrogen input and increased root production in drought conditions may lead to increased invasion of these species with expected global climate change. © 2016 Botanical Society of America.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-12

... 135, Environmental Conditions and Test Procedures for Airborne Equipment AGENCY: Federal Aviation... 135, Environmental Conditions and Test Procedures for Airborne Equipment SUMMARY: The FAA is issuing..., Environmental Conditions and Test Procedures for Airborne Equipment DATES: The meeting will be held November 8...

77 FR 15449 - 59th Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures for...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-15

... 135, Environmental Conditions and Test Procedures for Airborne Equipment AGENCY: Federal Aviation... 135, Environmental Conditions and Test Procedures for Airborne Equipment. SUMMARY: The FAA is issuing..., Environmental Conditions and Test Procedures for Airborne Equipment. DATES: The meeting will be held April 19...

78 FR 43963 - Sixty-Second Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-22

... Committee 135, Environmental Conditions and Test Procedures for Airborne Equipment AGENCY: Federal Aviation... 135, Environmental Conditions and Test Procedures for Airborne Equipment. SUMMARY: The FAA is issuing..., Environmental Conditions and Test Procedures for Airborne Equipment. DATES: The meeting will be held November 13...

78 FR 7850 - Sixty First Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-04

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Environmental Fate and Biological Consequences of Chemicals Related to Air Force Activities

DTIC Science & Technology

1982-09-01

milliliters of a 10% solution over a 78.5-square centimeter surface. Sample treated cores were tested under laboratory conditions and in field studies and using...natural weather conditions for comparative tests. No Sig- nificant differences were noted between field and laboratory conditions . Biological...JP-4- and JP-5-dosed cores initially show a stressed condition as indicated by an increased rate in CO2 produc- tion followed by a rate of CO2

Environmental Selection, Dispersal, and Organism Interactions Shape Community Assembly in High-Throughput Enrichment Culturing

DOE PAGES

Justice, N. B.; Sczesnak, A.; Hazen, T. C.; ...

2017-08-04

A central goal of microbial ecology is to identify and quantify the forces that lead to observed population distributions and dynamics. However, these forces, which include environmental selection, dispersal, and organism interactions, are often difficult to assess in natural environments. Here in this paper, we present a method that links microbial community structures with selective and stochastic forces through highly replicated subsampling and enrichment of a single environmental inoculum. Specifically, groundwater from a well-studied natural aquifer was serially diluted and inoculated into nearly 1,000 aerobic and anaerobic nitrate-reducing cultures, and the final community structures were evaluated with 16S rRNA genemore » amplicon sequencing. We analyzed the frequency and abundance of individual operational taxonomic units (OTUs) to understand how probabilistic immigration, relative fitness differences, environmental factors, and organismal interactions contributed to divergent distributions of community structures. We further used a most probable number (MPN) method to estimate the natural condition-dependent cultivable abundance of each of the nearly 400 OTU cultivated in our study and infer the relative fitness of each. Additionally, we infer condition-specific organism interactions and discuss how this high-replicate culturing approach is essential in dissecting the interplay between overlapping ecological forces and taxon-specific attributes that underpin microbial community assembly. IMPORTANCEThrough highly replicated culturing, in which inocula are subsampled from a single environmental sample, we empirically determine how selective forces, interspecific interactions, relative fitness, and probabilistic dispersal shape bacterial communities. These methods offer a novel approach to untangle not only interspecific interactions but also taxon-specific fitness differences that manifest across different cultivation conditions and lead to the selection and enrichment of specific organisms. Additionally, we provide a method for estimating the number of cultivable units of each OTU in the original sample through the MPN approach.« less

Environmental Selection, Dispersal, and Organism Interactions Shape Community Assembly in High-Throughput Enrichment Culturing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Justice, N. B.; Sczesnak, A.; Hazen, T. C.

A central goal of microbial ecology is to identify and quantify the forces that lead to observed population distributions and dynamics. However, these forces, which include environmental selection, dispersal, and organism interactions, are often difficult to assess in natural environments. Here in this paper, we present a method that links microbial community structures with selective and stochastic forces through highly replicated subsampling and enrichment of a single environmental inoculum. Specifically, groundwater from a well-studied natural aquifer was serially diluted and inoculated into nearly 1,000 aerobic and anaerobic nitrate-reducing cultures, and the final community structures were evaluated with 16S rRNA genemore » amplicon sequencing. We analyzed the frequency and abundance of individual operational taxonomic units (OTUs) to understand how probabilistic immigration, relative fitness differences, environmental factors, and organismal interactions contributed to divergent distributions of community structures. We further used a most probable number (MPN) method to estimate the natural condition-dependent cultivable abundance of each of the nearly 400 OTU cultivated in our study and infer the relative fitness of each. Additionally, we infer condition-specific organism interactions and discuss how this high-replicate culturing approach is essential in dissecting the interplay between overlapping ecological forces and taxon-specific attributes that underpin microbial community assembly. IMPORTANCEThrough highly replicated culturing, in which inocula are subsampled from a single environmental sample, we empirically determine how selective forces, interspecific interactions, relative fitness, and probabilistic dispersal shape bacterial communities. These methods offer a novel approach to untangle not only interspecific interactions but also taxon-specific fitness differences that manifest across different cultivation conditions and lead to the selection and enrichment of specific organisms. Additionally, we provide a method for estimating the number of cultivable units of each OTU in the original sample through the MPN approach.« less

Effects of environmental conditions on point-of-care cardiac biomarker test performance during a simulated rescue: implications for emergency and disaster response.

PubMed

Louie, Richard F; Ferguson, William J; Curtis, Corbin M; Vy, John H; Tang, Chloe S; Kost, Gerald J

2013-01-01

To characterize the effects of environmental stress on point-of-care (POC) cardiac biomarker testing during a simulated rescue. Multiplex test cassettes for cardiac troponin I (cTnI), brain natriuretic peptide (BNP), CK-MB, myoglobin, and D-dimer were exposed to environmental stresses simulating a 24-hour rescue from Hawaii to the Marshall Islands and back. We used Tenney environmental chambers (T2RC and BTRC) to simulate flight conditions (20°C, 10 percent relative humidity) and ground conditions (22.3-33.9°C, 73-77 percent). We obtained paired measurements using stressed versus control (room temperature) cassettes at seven time points (T1-7 with T1,2,6,7 during flight and T3-5 on ground). We analyzed paired differences (stressed minus control) with Wilcoxon signed rank test. We assessed the impact on decision-making at clinical thresholds. cTnI results from stressed test cassettes (n = 10) at T4 (p < 0.05), T5 (p < 0.01), and T7 (p < 0.05) differed significantly from control, when testing samples with median cTnI concentration of 90 ng/L. During the ground rescue, 36.7 percent (11/30) of cTnI measurements from stressed cassettes generated significantly lowered results. At T5, 20 percent (2/10) of cTnI results were highly discrepant-stressed cassettes reported normal results, when control results were >100 ng/L. With sample median concentration of 108 pg/mL, BNP results from stressed test cassettes differed significantly from controls (p < 0.05). Despite modest, short-term temperature elevation, environmental stresses led to erroneous results. False negative cTnI and BNP results potentially could miss acute myocardial infarction and congestive heart failure, confounded treatment, and increased mortality and morbidity. Therefore, rescuers should protect POC reagents from temperature extremes.

Vantage Sensitivity: Environmental Sensitivity to Positive Experiences as a Function of Genetic Differences.

PubMed

Pluess, Michael

2017-02-01

A large number of gene-environment interaction studies provide evidence that some people are more likely to be negatively affected by adverse experiences as a function of specific genetic variants. However, such "risk" variants are surprisingly frequent in the population. Evolutionary analysis suggests that genetic variants associated with increased risk for maladaptive development under adverse environmental conditions are maintained in the population because they are also associated with advantages in response to different contextual conditions. These advantages may include (a) coexisting genetic resilience pertaining to other adverse influences, (b) a general genetic susceptibility to both low and high environmental quality, and (c) a coexisting propensity to benefit disproportionately from positive and supportive exposures, as reflected in the recent framework of vantage sensitivity. After introducing the basic properties of vantage sensitivity and highlighting conceptual similarities and differences with diathesis-stress and differential susceptibility patterns of gene-environment interaction, selected and recent empirical evidence for the notion of vantage sensitivity as a function of genetic differences is reviewed. The unique contribution that the new perspective of vantage sensitivity may make to our understanding of social inequality will be discussed after suggesting neurocognitive and molecular mechanisms hypothesized to underlie the propensity to benefit disproportionately from benevolent experiences. © 2015 Wiley Periodicals, Inc.

Physical condition and stress levels during early development reflect feeding rates and predict pre- and post-fledging survival in a nearshore seabird

USGS Publications Warehouse

Lamb, Juliet S.; O'Reilly, Kathleen M.; Jodice, Patrick G.R.

2016-01-01

The effects of acute environmental stressors on reproduction in wildlife are often difficult to measure because of the labour and disturbance involved in collecting accurate reproductive data. Stress hormones represent a promising option for assessing the effects of environmental perturbations on altricial young; however, it is necessary first to establish how stress levels are affected by environmental conditions during development and whether elevated stress results in reduced survival and recruitment rates. In birds, the stress hormone corticosterone is deposited in feathers during the entire period of feather growth, making it an integrated measure of background stress levels during development. We tested the utility of feather corticosterone levels in 3- to 4-week-old nestling brown pelicans (Pelecanus occidentalis) for predicting survival rates at both the individual and colony levels. We also assessed the relationship of feather corticosterone to nestling body condition and rates of energy delivery to nestlings. Chicks with higher body condition and lower corticosterone levels were more likely to fledge and to be resighted after fledging, whereas those with lower body condition and higher corticosterone levels were less likely to fledge or be resighted after fledging. Feather corticosterone was also associated with intracolony differences in survival between ground and elevated nest sites. Colony-wide, mean feather corticosterone predicted nest productivity, chick survival and post-fledging dispersal more effectively than did body condition, although these relationships were strongest before fledglings dispersed away from the colony. Both reproductive success and nestling corticosterone were strongly related to nutritional conditions, particularly meal delivery rates. We conclude that feather corticosterone is a powerful predictor of reproductive success and could provide a useful metric for rapidly assessing the effects of changes in environmental conditions, provided pre-existing baseline variation is monitored and understood.

Physical condition and stress levels during early development reflect feeding rates and predict pre- and post-fledging survival in a nearshore seabird.

PubMed

Lamb, Juliet S; O'Reilly, Kathleen M; Jodice, Patrick G R

2016-01-01

The effects of acute environmental stressors on reproduction in wildlife are often difficult to measure because of the labour and disturbance involved in collecting accurate reproductive data. Stress hormones represent a promising option for assessing the effects of environmental perturbations on altricial young; however, it is necessary first to establish how stress levels are affected by environmental conditions during development and whether elevated stress results in reduced survival and recruitment rates. In birds, the stress hormone corticosterone is deposited in feathers during the entire period of feather growth, making it an integrated measure of background stress levels during development. We tested the utility of feather corticosterone levels in 3- to 4-week-old nestling brown pelicans ( Pelecanus occidentalis ) for predicting survival rates at both the individual and colony levels. We also assessed the relationship of feather corticosterone to nestling body condition and rates of energy delivery to nestlings. Chicks with higher body condition and lower corticosterone levels were more likely to fledge and to be resighted after fledging, whereas those with lower body condition and higher corticosterone levels were less likely to fledge or be resighted after fledging. Feather corticosterone was also associated with intracolony differences in survival between ground and elevated nest sites. Colony-wide, mean feather corticosterone predicted nest productivity, chick survival and post-fledging dispersal more effectively than did body condition, although these relationships were strongest before fledglings dispersed away from the colony. Both reproductive success and nestling corticosterone were strongly related to nutritional conditions, particularly meal delivery rates. We conclude that feather corticosterone is a powerful predictor of reproductive success and could provide a useful metric for rapidly assessing the effects of changes in environmental conditions, provided pre-existing baseline variation is monitored and understood.

Phylogenetic and functional traits of ectomycorrhizal assemblages in top soil from different biogeographic regions and forest types.

PubMed

Pena, Rodica; Lang, Christa; Lohaus, Gertrud; Boch, Steffen; Schall, Peter; Schöning, Ingo; Ammer, Christian; Fischer, Markus; Polle, Andrea

2017-04-01

Ectomycorrhizal (EM) fungal taxonomic, phylogenetic, and trait diversity (exploration types) were analyzed in beech and conifer forests along a north-to-south gradient in three biogeographic regions in Germany. The taxonomic community structures of the ectomycorrhizal assemblages in top soil were influenced by stand density and forest type, by biogeographic environmental factors (soil physical properties, temperature, and precipitation), and by nitrogen forms (amino acids, ammonium, and nitrate). While α-diversity did not differ between forest types, β-diversity increased, leading to higher γ-diversity on the landscape level when both forest types were present. The highest taxonomic diversity of EM was found in forests in cool, moist climate on clay and silty soils and the lowest in the forests in warm, dry climate on sandy soils. In the region with higher taxonomic diversity, phylogenetic clustering was found, but not trait clustering. In the warm region, trait clustering occurred despite neutral phylogenetic effects. These results suggest that different forest types and favorable environmental conditions in forests promote high EM species richness in top soil presumably with both high functional diversity and phylogenetic redundancy, while stressful environmental conditions lead to lower species richness and functional redundancy.

Seasonal variation in the biocontrol efficiency of bacterial wilt is driven by temperature-mediated changes in bacterial competitive interactions.

PubMed

Wei, Zhong; Huang, Jianfeng; Yang, Tianjie; Jousset, Alexandre; Xu, Yangchun; Shen, Qirong; Friman, Ville-Petri

2017-10-01

Microbe-based biocontrol applications hold the potential to become an efficient way to control plant pathogen disease outbreaks in the future. However, their efficiency is still very variable, which could be due to their sensitivity to the abiotic environmental conditions.Here, we assessed how environmental temperature variation correlates with ability of Ralstonia pickettii , an endophytic bacterial biocontrol agent, to suppress the Ralstonia solanacearum pathogen during different tomato crop seasons in China.We found that suppression of the pathogen was highest when the seasonal mean temperatures were around 20 °C and rapidly decreased with increasing mean crop season temperatures. Interestingly, low levels of disease incidence did not correlate with low pathogen or high biocontrol agent absolute densities. Instead, the biocontrol to pathogen density ratio was a more important predictor of disease incidence levels between different crop seasons. To understand this mechanistically, we measured the growth and strength of competition between the biocontrol agent and the pathogen over a naturally occurring temperature gradient in vitro . We found that the biocontrol strain grew relatively faster at low temperature ranges, and the pathogen at high temperature ranges, and that similar to field experiments, pathogen suppression peaked at 20 °C.Together, our results suggest that temperature-mediated changes in the strength of bacterial competition could potentially explain the variable R. solanacearum biocontrol outcomes between different crop seasons in China. Synthesis and applications . Our results suggest that abiotic environmental conditions, such as temperature, can affect the efficacy of biocontrol applications. Thus, in order to develop more consistent biocontrol applications in the future, we might need to find and isolate bacterial strains that can retain their functionality regardless of the changing environmental conditions.

International comparative study of childhood malignancy comparative study of pediatric malignancy between Kurume and Karachi (K-K Project 1991).

PubMed

Shakoor, A; Murakami, T; Yamashita, F

1991-01-01

A study was undertaken to compare Pediatric Malignancy at Kurume (Japan) and Karachi (Pakistan) with reference to international data collected over the years, in order to identify essential differences between developed and developing conditions and factors influencing the etio-pathogenesis of pediatric cancer. The study was retrospective encompassing all types of cancer in children over a period of three years i-e 1988-1990. Essential factors related to present study were: 1. The population of Karachi is about 10 million while that of Kurume is only half a million. 2. Socio-economic conditions: The average socio-economic condition of people in Karachi is poor while in Kurume it appears to be good. 3. Educational status: Only 25% people in Karachi are educated beyond middle class while Kurume reveals a 100% education up to high school level. 4. Environmental conditions: The environmental conditions of Kurume and surrounding areas are very clean and free from pollution, sewage problems and traffic hazards. Karachi and its surroundings on the other hand pose very serious air and water industries! It was concluded that whereas genetic predisposition predominates, the environmental conditions, educational and socio-economic status of a society immensely influence the pattern and trends of pediatric carcinogenesis.

Predictability and environmental drivers of chlorophyll fluctuations vary across different time scales and regions of the North Sea

NASA Astrophysics Data System (ADS)

Blauw, Anouk N.; Benincà, Elisa; Laane, Remi W. P. M.; Greenwood, Naomi; Huisman, Jef

2018-02-01

Phytoplankton concentrations display strong temporal variability at different time scales. Recent advances in automated moorings enable detailed investigation of this variability. In this study, we analyzed phytoplankton fluctuations at four automated mooring stations in the North Sea, which measured phytoplankton abundance (chlorophyll) and several environmental variables at a temporal resolution of 12-30 min for two to nine years. The stations differed in tidal range, water depth and freshwater influence. This allowed comparison of the predictability and environmental drivers of phytoplankton variability across different time scales and geographical regions. We analyzed the time series using wavelet analysis, cross correlations and generalized additive models to quantify the response of chlorophyll fluorescence to various environmental variables (tidal and meteorological variables, salinity, suspended particulate matter, nitrate and sea surface temperature). Hour-to-hour and day-to-day fluctuations in chlorophyll fluorescence were substantial, and mainly driven by sinking and vertical mixing of phytoplankton cells, horizontal transport of different water masses, and non-photochemical quenching of the fluorescence signal. At the macro-tidal stations, these short-term phytoplankton fluctuations were strongly driven by the tides. Along the Dutch coast, variation in salinity associated with the freshwater influence of the river Rhine played an important role, while in the central North Sea variation in weather conditions was a major determinant of phytoplankton variability. At time scales of weeks to months, solar irradiance, nutrient conditions and thermal stratification were the dominant drivers of changes in chlorophyll concentrations. These results show that the dominant drivers of phytoplankton fluctuations differ across marine environments and time scales. Moreover, our findings show that phytoplankton variability on hourly to daily time scales should not be dismissed as environmental noise, but is related to vertical and horizontal particle transport driven by winds and tides. Quantification of these transport processes contributes to an improved predictability of marine phytoplankton concentrations.

Methods to Calculate the Heat Index as an Exposure Metric in Environmental Health Research

PubMed Central

Bell, Michelle L.; Peng, Roger D.

2013-01-01

Background: Environmental health research employs a variety of metrics to measure heat exposure, both to directly study the health effects of outdoor temperature and to control for temperature in studies of other environmental exposures, including air pollution. To measure heat exposure, environmental health studies often use heat index, which incorporates both air temperature and moisture. However, the method of calculating heat index varies across environmental studies, which could mean that studies using different algorithms to calculate heat index may not be comparable. Objective and Methods: We investigated 21 separate heat index algorithms found in the literature to determine a) whether different algorithms generate heat index values that are consistent with the theoretical concepts of apparent temperature and b) whether different algorithms generate similar heat index values. Results: Although environmental studies differ in how they calculate heat index values, most studies’ heat index algorithms generate values consistent with apparent temperature. Additionally, most different algorithms generate closely correlated heat index values. However, a few algorithms are potentially problematic, especially in certain weather conditions (e.g., very low relative humidity, cold weather). To aid environmental health researchers, we have created open-source software in R to calculate the heat index using the U.S. National Weather Service’s algorithm. Conclusion: We identified 21 separate heat index algorithms used in environmental research. Our analysis demonstrated that methods to calculate heat index are inconsistent across studies. Careful choice of a heat index algorithm can help ensure reproducible and consistent environmental health research. Citation: Anderson GB, Bell ML, Peng RD. 2013. Methods to calculate the heat index as an exposure metric in environmental health research. Environ Health Perspect 121:1111–1119; http://dx.doi.org/10.1289/ehp.1206273 PMID:23934704

Realized niches explain spatial gradients in seasonal abundance of phytoplankton groups in the South China Sea

NASA Astrophysics Data System (ADS)

Xiao, Wupeng; Wang, Lei; Laws, Edward; Xie, Yuyuan; Chen, Jixin; Liu, Xin; Chen, Bingzhang; Huang, Bangqin

2018-03-01

A basic albeit elusive goal of ocean science is to predict the structure of biological communities from the multitude of environmental conditions they experience. Estimates of the realized niche-based traits (realized traits) of phytoplankton species or functional groups in temperate seas have shown that response traits can help reveal the mechanisms responsible for structuring phytoplankton communities, but such approaches have not been tested in tropical and subtropical marginal seas. Here, we used decadal-scale studies of pigment-based phytoplankton groups and environmental conditions in the South China Sea to test whether realized traits could explain the biogeographic patterns of phytoplankton variability. We estimated the mean and breadth of the phytoplankton realized niches based on responses of the group-specific phytoplankton composition to key environmental factors, and we showed that variations of major phytoplankton groups in this system can be explained by different adaptive trade-offs to constraints imposed by temperature, irradiance, and nutrient concentrations. Differences in the patterns of trade-offs clearly separated the dominant groups from one another and generated four sets of realized traits that mirrored the observed biogeographic distribution patterns. The phytoplankton realized niches and their associated traits that we characterized in the present study could help to predict responses of phytoplankton to changes in environmental conditions in the South China Sea and could be incorporated into global biogeochemical models to anticipate shifts in community structure under future climate scenarios.

Aligning the Measurement of Microbial Diversity with Macroecological Theory

DOE PAGES

Stegen, James C.; Hurlbert, Allen H.; Bond-Lamberty, Ben; ...

2016-09-23

The number of microbial operational taxonomic units (OTUs) within a community is akin to species richness within plant/animal (‘macrobial’) systems. A large literature documents OTU richness patterns, drawing comparisons to macrobial theory. There is, however, an unrecognized fundamental disconnect between OTU richness and macrobial theory: OTU richness is commonly estimated on a per-individual basis, while macrobial richness is estimated per-area. Furthermore, the range or extent of sampled environmental conditions can strongly influence a study’s outcomes and conclusions, but this is not commonly addressed when studying OTU richness. Here we (i) propose a new sampling approach that estimates OTU richness per-massmore » of soil, which results in strong support for species energy theory, (ii) use data reduction to show how support for niche conservatism emerges when sampling across a restricted range of environmental conditions, and (iii) show how additional insights into drivers of OTU richness can be generated by combining different sampling methods while simultaneously considering patterns that emerge by restricting the range of environmental conditions. We propose that a more rigorous connection between microbial ecology and macrobial theory can be facilitated by exploring how changes in OTU richness units and environmental extent influence outcomes of data analysis. While fundamental differences between microbial and macrobial systems persist (e.g., species concepts), we suggest that closer attention to units and scale provide tangible and immediate improvements to our understanding of the processes governing OTU richness and how those processes relate to drivers of macrobial species richness.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stegen, James C.; Hurlbert, Allen H.; Bond-Lamberty, Ben

The number of microbial operational taxonomic units (OTUs) within a community is akin to species richness within plant/animal (‘macrobial’) systems. A large literature documents OTU richness patterns, drawing comparisons to macrobial theory. There is, however, an unrecognized fundamental disconnect between OTU richness and macrobial theory: OTU richness is commonly estimated on a per-individual basis, while macrobial richness is estimated per-area. Furthermore, the range or extent of sampled environmental conditions can strongly influence a study’s outcomes and conclusions, but this is not commonly addressed when studying OTU richness. Here we (i) propose a new sampling approach that estimates OTU richness per-massmore » of soil, which results in strong support for species energy theory, (ii) use data reduction to show how support for niche conservatism emerges when sampling across a restricted range of environmental conditions, and (iii) show how additional insights into drivers of OTU richness can be generated by combining different sampling methods while simultaneously considering patterns that emerge by restricting the range of environmental conditions. We propose that a more rigorous connection between microbial ecology and macrobial theory can be facilitated by exploring how changes in OTU richness units and environmental extent influence outcomes of data analysis. While fundamental differences between microbial and macrobial systems persist (e.g., species concepts), we suggest that closer attention to units and scale provide tangible and immediate improvements to our understanding of the processes governing OTU richness and how those processes relate to drivers of macrobial species richness.« less

Individual quality and age but not environmental or social conditions modulate costs of reproduction in a capital breeder.

PubMed

Debeffe, Lucie; Poissant, Jocelyn; McLoughlin, Philip D

2017-08-01

Costs associated with reproduction are widely known to play a role in the evolution of reproductive tactics with consequences to population and eco-evolutionary dynamics. Evaluating these costs as they pertain to species in the wild remains an important goal of evolutionary ecology. Individual heterogeneity, including differences in individual quality (i.e., among-individual differences in traits associated with survival and reproduction) or state, and variation in environmental and social conditions can modulate the costs of reproduction; however, few studies have considered effects of these factors simultaneously. Taking advantage of a detailed, long-term dataset for a population of feral horses (Sable Island, Nova Scotia, Canada), we address the question of how intrinsic (quality, age), environmental (winter severity, location), and social conditions (group size, composition, sex ratio, density) influence the costs of reproduction on subsequent reproduction. Individual quality was measured using a multivariate analysis on a combination of four static and dynamic traits expected to depict heterogeneity in individual performance. Female quality and age interacted with reproductive status of the previous year to determine current reproductive effort, while no effect of social or environmental covariates was found. High-quality females showed higher probabilities of giving birth and weaning their foal regardless of their reproductive status the previous year, while those of lower quality showed lower probabilities of producing foals in successive years. Middle-aged (prime) females had the highest probability of giving birth when they had not reproduced the year before, but no such relationship with age was found among females that had reproduced the previous year, indicating that prime-aged females bear higher costs of reproduction. We show that individual quality and age were key factors modulating the costs of reproduction in a capital breeder but that environmental or social conditions were not, highlighting the importance of considering multiple factors when studying costs of reproduction.

Regional-scale drivers of marine nematode distribution in Southern Ocean continental shelf sediments

NASA Astrophysics Data System (ADS)

Hauquier, Freija; Verleyen, Elie; Tytgat, Bjorn; Vanreusel, Ann

2018-07-01

Many marine meiofauna taxa seem to possess cosmopolitan species distributions, despite their endobenthic lifestyle and restricted long-distance dispersal capacities. In light of this paradox we used a metacommunity framework to study spatial turnover in free-living nematode distribution and assess the importance of local environmental conditions in explaining differences between communities in surface and subsurface sediments of the Southern Ocean continental shelf. We analysed nematode community structure in two sediment layers (0-3 cm and 3-5 cm) of locations maximum 2400 km apart. We first focused on a subset of locations to evaluate whether the genus level is sufficiently taxonomically fine-grained to study large-scale patterns in nematode community structure. We subsequently used redundancy and variation partitioning analyses to quantify the unique and combined effects of local environmental conditions and spatial descriptors on genus-level community composition. Macroecological patterns in community structure were highly congruent at the genus and species level. Nematode community composition was highly divergent between both depth strata, likely as a result of local abiotic conditions. Variation in community structure between the different regions largely stemmed from turnover (i.e. genus/species replacement) rather than nestedness (i.e. genus/species loss). The level of turnover among communities increased with geographic distance and was more pronounced in subsurface layers compared to surface sediments. Variation partitioning analysis revealed that both environmental and spatial predictors significantly explained variation in community structure. Moreover, the shared fraction of both sets of variables was high, which suggested a substantial amount of spatially structured environmental variation. Additionally, the effect of space independent of environment was much higher than the effect of environment independent of space, which shows the importance of including spatial descriptors in meiofauna and nematode community ecology. Large-scale assessment of free-living nematode diversity and abundance in the Southern Ocean shelf zone revealed strong horizontal and vertical spatial structuring in response to local environmental conditions, in combination with (most likely) dispersal limitation.

The Socio-Exposome: Advancing Exposure Science and Environmental Justice in a Post-Genomic Era

PubMed Central

Senier, Laura; Brown, Phil; Shostak, Sara; Hanna, Bridget

2017-01-01

We propose the socio-exposome as a conceptual framework for integrative environmental health research. Environmental scientists coined the term “exposome” with the goal of inventorying and quantifying environmental exposures as precisely as scientists measure genes and gene expression. To date, the exposome’s proponents have not thoroughly engaged social scientific theoretical and methodological expertise, although the exclusion of sociological expertise risks molecularizing complex social phenomena and limiting the possibility of collective action to improve environmental conditions. As a corrective, and to demonstrate how “omic” technologies could be made more relevant to public health, our socio-exposome framework blends insights from sociological and public health research with insights from environmental justice scholarship and activism. We argue that environmental health science requires more comprehensive data on more and different kinds of environmental exposures, but also must consider the socio-political conditions and inequalities that allow hazards to continue unchecked. We propose a multidimensional framework oriented around three axes: individual, local, and global, and suggest some sociomarkers and data sources that could identify exposures at each level. This framework could also guide policy, by creating a predictive framework that helps communities understand the repercussions of corporate and regulatory practices for public health and social justice. PMID:28944245

DNA methylation and methylation polymorphism in ecotypes of Jatropha curcas L. using methylation-sensitive AFLP markers.

PubMed

Mastan, Shaik G; Rathore, Mangal S; Bhatt, Vacha D; Chikara, J; Ghosh, A

2014-12-01

We investigated DNA methylation and polymorphism in the methylated DNA using AFLP based methylation-sensitive amplification polymorphism (MS-AFLP) markers in ecotypes of Jatropha curcas L. growing in similar and different geo-ecological conditions. Three ecotypes growing in different geo-ecological conditions with environmental heterogeneity (Group-1) and five ecotypes growing in similar environmental conditions (Group-2) were assessed. In ecotypes growing in group-1, 44.32 % DNA was methylated and of which 93.59 % DNA was polymorphic. While in group-2, 32.27 % DNA was methylated, of which 51.64 % DNA was polymorphic. In site 1 and site 2 of group-1, overall methylation was 18.94 and 22.44 % respectively with difference of 3.5 %, while overall polymorphism was 41.14 and 39.23 % with a difference of 1.91 %. In site 1 and site 2 of group-2, overall methylation was 24.68 and 24.18 % respectively with difference of 0.5 %, while overall polymorphism was 12.19 and 12.65 % with a difference of 0.46 %. The difference of methylation percentage and percentage of methylation polymorphism throughout the genome of J. curcas at site 1 and 2 of group-1 is higher than that of J. curcas at site 1 and 2 of group-2. These results correlated the physico-chemical properties of soil at these sites. The variations of physico-chemical properties of soil at Chorwadla (site 1 in group-1 and site 2 in group-2) compared to the soil at Brahmapur (site 2 in group-1) is higher than that of soil at Neswad (site 1 in group-2). The study suggests that these homologous nucleotide sequences probably play important role in ecotype adaptation to environmental heterogeneity by creating epiallelic variations hence in evolution of ecotypes/clines or forms of species showing phenotypic/genotypic differences in different geographical areas.

Comparative ecophysiology of a critically endangered (CR) ectotherm: Implications for conservation management.

PubMed

Currylow, Andrea F T; Mandimbihasina, Angelo; Gibbons, Paul; Bekarany, Ernest; Stanford, Craig B; Louis, Edward E; Crocker, Daniel E

2017-01-01

Captive breeding is a vital conservation tool for many endangered species programs. It is often a last resort when wild animal population numbers drop to below critical minimums for natural reproduction. However, critical ecophysiological information of wild counterparts may not be well documented or understood, leading to years of minimal breeding successes. We collected endocrine and associated ecological data on a critically endangered ectotherm concurrently in the wild and in captivity over several years. We tracked plasma concentrations of steroid stress and reproductive hormones, body condition, activity, and environmental parameters in three populations (one wild and two geographically distinct captive) of ploughshare tortoise (Astrochelys yniphora). Hormone profiles along with environmental and behavioral data are presented and compared. We show that animals have particular seasonal environmental requirements that can affect annual reproduction, captivity affects reproductive state, and sociality may be required at certain times of the year for breeding to be successful. Our data suggest that changes in climatic conditions experienced by individuals, either due to decades-long shifts or hemispheric differences when translocated from their native range, can stifle breeding success for several years while the animals physiologically acclimatize. We also found that captivity affects stress (plasma corticosterone) and body condition of adults and juveniles differently and seasonally. Our results indicate that phenotypic plasticity in reproduction and behavior is related to environmental cues in long-lived ectotherms, and detailed ecophysiological data should be used when establishing and improving captive husbandry conditions for conservation breeding programs. Further, considering the recent revelation of this tortoises' possible extirpation from the wild, these data are critically opportune and may be key to the survival of this species.

Comparative ecophysiology of a critically endangered (CR) ectotherm: Implications for conservation management

PubMed Central

Mandimbihasina, Angelo; Gibbons, Paul; Bekarany, Ernest; Stanford, Craig B.; Louis, Edward E.; Crocker, Daniel E.

2017-01-01

Captive breeding is a vital conservation tool for many endangered species programs. It is often a last resort when wild animal population numbers drop to below critical minimums for natural reproduction. However, critical ecophysiological information of wild counterparts may not be well documented or understood, leading to years of minimal breeding successes. We collected endocrine and associated ecological data on a critically endangered ectotherm concurrently in the wild and in captivity over several years. We tracked plasma concentrations of steroid stress and reproductive hormones, body condition, activity, and environmental parameters in three populations (one wild and two geographically distinct captive) of ploughshare tortoise (Astrochelys yniphora). Hormone profiles along with environmental and behavioral data are presented and compared. We show that animals have particular seasonal environmental requirements that can affect annual reproduction, captivity affects reproductive state, and sociality may be required at certain times of the year for breeding to be successful. Our data suggest that changes in climatic conditions experienced by individuals, either due to decades-long shifts or hemispheric differences when translocated from their native range, can stifle breeding success for several years while the animals physiologically acclimatize. We also found that captivity affects stress (plasma corticosterone) and body condition of adults and juveniles differently and seasonally. Our results indicate that phenotypic plasticity in reproduction and behavior is related to environmental cues in long-lived ectotherms, and detailed ecophysiological data should be used when establishing and improving captive husbandry conditions for conservation breeding programs. Further, considering the recent revelation of this tortoises’ possible extirpation from the wild, these data are critically opportune and may be key to the survival of this species. PMID:28813439

Spatially Explicit Modeling Reveals Cephalopod Distributions Match Contrasting Trophic Pathways in the Western Mediterranean Sea

PubMed Central

Puerta, Patricia; Hunsicker, Mary E.; Quetglas, Antoni; Álvarez-Berastegui, Diego; Esteban, Antonio; González, María; Hidalgo, Manuel

2015-01-01

Populations of the same species can experience different responses to the environment throughout their distributional range as a result of spatial and temporal heterogeneity in habitat conditions. This highlights the importance of understanding the processes governing species distribution at local scales. However, research on species distribution often averages environmental covariates across large geographic areas, missing variability in population-environment interactions within geographically distinct regions. We used spatially explicit models to identify interactions between species and environmental, including chlorophyll a (Chla) and sea surface temperature (SST), and trophic (prey density) conditions, along with processes governing the distribution of two cephalopods with contrasting life-histories (octopus and squid) across the western Mediterranean Sea. This approach is relevant for cephalopods, since their population dynamics are especially sensitive to variations in habitat conditions and rarely stable in abundance and location. The regional distributions of the two cephalopod species matched two different trophic pathways present in the western Mediterranean Sea, associated with the Gulf of Lion upwelling and the Ebro river discharges respectively. The effects of the studied environmental and trophic conditions were spatially variant in both species, with usually stronger effects along their distributional boundaries. We identify areas where prey availability limited the abundance of cephalopod populations as well as contrasting effects of temperature in the warmest regions. Despite distributional patterns matching productive areas, a general negative effect of Chla on cephalopod densities suggests that competition pressure is common in the study area. Additionally, results highlight the importance of trophic interactions, beyond other common environmental factors, in shaping the distribution of cephalopod populations. Our study presents a valuable approach for understanding the spatially variant ecology of cephalopod populations, which is important for fisheries and ecosystem management. PMID:26201075

Survival differences and the effect of environmental instability on breeding dispersal in an Adélie penguin meta-population

PubMed Central

Dugger, Katie M.; Ainley, David G.; Lyver, Phil O'B.; Barton, Kerry; Ballard, Grant

2010-01-01

High survival and breeding philopatry was previously confirmed for the Adélie penguin (Pygoscelis adeliae) during a period of stable environmental conditions. However, movements of breeding adults as a result of an unplanned natural experiment within a four-colony meta-population provided interesting insights into this species’ population dynamics. We used multistate mark-recapture models to investigate apparent survival and dispersal of breeding birds in the southwestern Ross Sea during 12 breeding seasons (1996–2007). The natural experiment was facilitated by the temporary grounding of two immense icebergs that (i) erected a veritable fence separating colonies and altering migration routes and (ii) added additional stress by trapping extensive sea ice in the region during 5 of 12 y. Colony size varied by orders of magnitude, allowing investigation of apparent survival and dispersal rates in relation to both environmental conditions and colony size within this meta-population. Apparent survival was lowest for the smallest colony (4,000 pairs) and similar for the medium (45,000 pairs) and large colonies (155,000 pairs), despite increased foraging effort expended by breeders at the largest colony. Dispersal of breeding birds was low (<1%), except during years of difficult environmental conditions when movements increased, especially away from the smallest colony (3.5%). Decreased apparent survival at the smallest colony could reflect differences in migration chronology and winter habitat use compared with the other colonies, or it may reflect increased permanent emigration to colonies outside this meta-population. Contrary to current thought, breeding penguins are not always philopatric. Rather, stressful conditions can significantly increase dispersal rates. PMID:20566874

Ensemble of European regional climate simulations for the winter of 2013 and 2014 from HadAM3P-RM3P

NASA Astrophysics Data System (ADS)

Schaller, Nathalie; Sparrow, Sarah N.; Massey, Neil R.; Bowery, Andy; Miller, Jonathan; Wilson, Simon; Wallom, David C. H.; Otto, Friederike E. L.

2018-04-01

Large data sets used to study the impact of anthropogenic climate change on the 2013/14 floods in the UK are provided. The data consist of perturbed initial conditions simulations using the Weather@Home regional climate modelling framework. Two different base conditions, Actual, including atmospheric conditions (anthropogenic greenhouse gases and human induced aerosols) as at present and Natural, with these forcings all removed are available. The data set is made up of 13 different ensembles (2 actual and 11 natural) with each having more than 7500 members. The data is available as NetCDF V3 files representing monthly data within the period of interest (1st Dec 2013 to 15th February 2014) for both a specified European region at a 50 km horizontal resolution and globally at N96 resolution. The data is stored within the UK Natural and Environmental Research Council Centre for Environmental Data Analysis repository.

Evaluation of the boundary condition influence on PAH concentrations in the water column during the sediment dredging of a port.

PubMed

Cutroneo, L; Castellano, M; Carbone, C; Consani, S; Gaino, F; Tucci, S; Magrì, S; Povero, P; Bertolotto, R M; Canepa, G; Capello, M

2015-12-30

The mobilisation of sediments and related contaminants connected to dredging activities is one of the most critical issues to the environmental risk and exposure assessment of a dredging project. The aim of this paper was an investigation of the mobilisation of polycyclic aromatic hydrocarbons (PAHs) due to the dredging of the Port of Genoa (Italy) to identify the temporal and spatial extent of the contaminant transport, and the influence of the dredging and the boundary conditions on it. The results showed relatively low background PAH concentrations in the water column and confirmed the dredging as the primary rising factor of concentrations in the water column, but also showed a complex scenario in which the different environmental and dredging factors forced the concentrations at different levels and moments. The post dredging phase showed PAH values close to the background conditions and the concentrations remained relatively high only for a few PAHs.

The low-temperature method for study of coniferous tissues in the environmental scanning electron microscope.

PubMed

Neděla, Vilém; Tihlaříková, Eva; Hřib, Jiří

2015-01-01

The use of non-standard low-temperature conditions in environmental scanning electron microscopy might be promising for the observation of coniferous tissues in their native state. This study is aimed to analyse and evaluate the method based on the principle of low-temperature sample stabilization. We demonstrate that the upper mucous layer is sublimed and a microstructure of the sample surface can be observed with higher resolution at lower gas pressure conditions, thanks to a low-temperature method. An influence of the low-temperature method on sample stability was also studied. The results indicate that high-moisture conditions are not suitable for this method and often cause the collapse of samples. The potential improvement of stability to beam damage has been demonstrated by long-time observation at different operation parameters. We finally show high applicability of the low-temperature method on different types of conifers and Oxalis acetosella. © 2014 Wiley Periodicals, Inc.

Contrasting seasonal and aseasonal environments across stages of the annual cycle in the Rufous-collared Sparrow, Zonotrichia capensis: differences in endocrine function, proteome, and body condition.

PubMed

González-Gómez, Paulina L; Echeverria, Valentina; Estades, Cristian F; Perez, Jonathan H; Krause, Jesse S; Sabat, Pablo; Li, Jonathon; Kültz, Dietmar; Wingfield, John C

2018-05-09

1.The timing and duration of life history stages (LHS) within the annual cycle can be affected by local environmental cues which are integrated through endocrine signaling mechanisms and changes in protein function. Most animals express a single LHS within a given period of the year because synchronous expression of LHSs is thought to be too costly energetically. However, in very rare and extremely stable conditions, breeding and molt have been observed to overlap extensively in Rufous-collared sparrows (Zonotrichia capensis) living in valleys of the Atacama Desert - one of the most stable and aseasonal environments on Earth. 2.To examine how LHS traits at different levels of organization are affected by environmental variability we compared the temporal organization and duration of LHSs in populations in the Atacama Desert with those in the semiarid Fray Jorge National Park in the north of Chile - an extremely seasonal climate but with unpredictable droughts and heavy rainy seasons. 3.We studied the effects of environmental variability on morphological variables related to body condition, endocrine traits, and proteome. Birds living in the seasonal environment had a strict temporal division LHSs while birds living in the aseasonal environment failed to maintain a temporal division of LHSs resulting in direct overlap of breeding and molt. Further, higher circulating glucocorticoids and androgen concentrations were found in birds from seasonal compared to aseasonal populations. Despite these differences, body condition variables and protein expression were not related to the degree of seasonality but rather showed a strong relationship with hormone levels. 4.These results suggest that animals adjust to their environment through changes in behavioral and endocrine traits and may be limited by less labile traits such as morphological variables or expression of specific proteins under certain circumstances. These data on free-living birds shed light on how different levels of life history organization within an individual are linked to increasing environmental heterogeneity. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Variability in foraging behaviour of red-footed boobies nesting on Europa Island

NASA Astrophysics Data System (ADS)

Mendez, Loriane; Cotté, Cédric; Prudor, Aurélien; Weimerskirch, Henri

2016-04-01

Seabirds are considered to be good indicators of the marine environment. However, little is known about the effects of environmental variability on the foraging behaviour of tropical seabirds. Red-footed boobies (RFB) nesting on Europa Island (Mozambique Channel) were fitted with GPS devices over four years and different breeding stages. We first show that the durations of foraging trips vary extensively according to the stage of the breeding, being short during brooding, intermediate during incubation and long during fledging. This result highlights the importance of considering breeding stage when conducting comparisons of foraging between sites or years. In addition, we show that RFB adjusted their foraging behaviour between years (2003, 2011, 2012 and 2013) according to the prevailing environmental conditions. During 2011, RFB made longer foraging trips with larger area-restricted search (ARS) zones over a larger total surface area, suggesting that the foraging conditions were probably poor. This year was characterized by a decrease of the major environmental drivers of the Mozambique Channel system, i.e. particularly low chlorophyll concentrations in the northern part of the Mozambique Channel, as well as a weak eddy activity. This observation suggests that environmental conditions may have altered the southward transport and concentration processes structuring the trophic chain, leading to adverse conditions for a central-place forager like the RFB. Our results emphasize that environmental and breeding stage variation should be taken into account to better understand the distribution of these predators in marine tropical ecosystems.

Plant-Pathogen Warfare under Changing Climate Conditions.

PubMed

Velásquez, André C; Castroverde, Christian Danve M; He, Sheng Yang

2018-05-21

Global environmental changes caused by natural and human activities have accelerated in the past 200 years. The increase in greenhouse gases is predicted to continue to raise global temperature and change water availability in the 21 st century. In this Review, we explore the profound effect the environment has on plant diseases - a susceptible host will not be infected by a virulent pathogen if the environmental conditions are not conducive for disease. The change in CO 2 concentrations, temperature, and water availability can have positive, neutral, or negative effects on disease development, as each disease may respond differently to these variations. However, the concept of disease optima could potentially apply to all pathosystems. Plant resistance pathways, including pattern-triggered immunity to effector-triggered immunity, RNA interference, and defense hormone networks, are all affected by environmental factors. On the pathogen side, virulence mechanisms, such as the production of toxins and virulence proteins, as well as pathogen reproduction and survival are influenced by temperature and humidity. For practical reasons, most laboratory investigations into plant-pathogen interactions at the molecular level focus on well-established pathosystems and use a few static environmental conditions that capture only a fraction of the dynamic plant-pathogen-environment interactions that occur in nature. There is great need for future research to increasingly use dynamic environmental conditions in order to fully understand the multidimensional nature of plant-pathogen interactions and produce disease-resistant crop plants that are resilient to climate change. Copyright © 2018 Elsevier Ltd. All rights reserved.

Influence of environmental factors on food intake and choice of beverage during meals in teenagers: a laboratory study.

PubMed

Péneau, Sandrine; Mekhmoukh, Amira; Chapelot, Didier; Dalix, Anne-Marie; Airinei, Gheorghe; Hercberg, Serge; Bellisle, France

2009-12-01

Environmental conditions influence meal size in adults and children. Intake of sweet drinks could contribute significantly to energy intake and potentially affect body weight, particularly in young individuals. The objectives of the present study were to measure the lunch intake of food and drinks under controlled laboratory settings in teenagers and to compare the influence of different meal conditions. Normal-weight adolescents (fourteen males and fifteen females) participated in four standardised lunches, scheduled 1 week apart. The same popular items (meat dish, dessert, water, juice, soda) were served at all meals. Ad libitum intake was measured under four conditions: subjects ate alone; in groups; alone while viewing television; alone while listening to music. Visual analogue scales were used to assess pre- and post-meal hunger and thirst and meal palatability. Energy, solid food and fluid intake was different (significantly lower) only in the 'eating in group' condition, in spite of identical intensity of pre-meal hunger. More soda was consumed when participants were watching television, and more water was consumed while listening to music. Across all conditions, more soda than water was consumed. Post-meal ratings of hunger, thirst and palatability did not differ between conditions. We concluded that, in teenagers, a 'social inhibition' effect appears rather than the 'social facilitation' previously reported in adults. Although teenagers do not respond to the presence of television or another 'distractor' such as music by eating more, they do ingest more soda when the television is on. The social significance of meals, conditioned responses and habituation to 'distractors' may be different between adolescents and adults.

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

USGS Publications Warehouse

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

2011-01-01

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

Blood lead and carboxyhemoglobin levels in chainsaw operators.

PubMed

van Netten, C; Brubaker, R L; Mackenzie, C J; Godolphin, W J

1987-06-01

Fallers in the British Columbia west coast lumber industry often work in climatic and local conditions where little ventilation in their immediate environment is possible. Under these conditions carbon monoxide (CO) and lead fumes from exhaust gases could build up and become a serious occupational hazard. This study monitored the environmental exposure of six fallers to carbon monoxide, nitrogen oxides, and lead under conditions where buildup of these agents would be expected. At the same time blood samples were taken to correlate these environmental concentrations to carboxyhemoglobin (COHb) and blood lead levels. Although there was a highly significant difference between the fallers and the controls regarding the exposure to CO and lead as well as their corresponding COHb and blood lead levels, the environmental and blood concentration of the agents in question did not exceed the maximum allowable concentrations. Temporary short fluctuations in carboxyhemoglobin levels were not monitored in this study and cannot be ruled out as a potential occupational hazard.

Rainfall thresholds for the activation of shallow landslides in the Italian Alps: the role of environmental conditioning factors

NASA Astrophysics Data System (ADS)

Palladino, M. R.; Viero, A.; Turconi, L.; Brunetti, M. T.; Peruccacci, S.; Melillo, M.; Luino, F.; Deganutti, A. M.; Guzzetti, F.

2018-02-01

The aim of the present work is to investigate the role exerted by selected environmental factors in the activation of rainfall-triggered shallow landslides and to identify site-specific rainfall thresholds. The study concerns the Italian Alps. The region is exposed to widespread slope instability phenomena due to its geological, morphological and climatic features. Furthermore, the high level of anthropization that characterizes wide portions of the territory increases the associated risk. Hence, the analysis of potential predisposing factors influencing landslides triggering is worthwhile to improve the current prediction skills and to enhance the preparedness and the response to these natural hazards. During the last years, the Italian National Research Council's Research Institute for Hydro-geological Protection (CNR-IRPI) has contributed to the analysis of triggering conditions for rainfall-induced landslides in the framework of a national project. The project, funded by the National Department for Civil Protection (DPC), focuses on the identification of the empirical rainfall thresholds for the activation of shallow landslides in Italy. The first outcomes of the project reveal a certain variability of the pluviometric conditions responsible for the mass movements activation, when different environmental settings are compared. This variability is probably related to the action of local environmental factors, such as lithology, climatic regime or soil characteristics. Based on this hypothesis, the present study aims to identify separated domains within the Italian Alps, where different triggering conditions exist and different countermeasures are needed for risk prevention. For this purpose, we collected information concerning 511 landslides activated in the period 2000-2012 and reconstructed 453 rainfall events supposed to be responsible for the activations. Then, we selected a set of thematic maps to represent the hypothesised landslide conditioning factors and to identify the supposed homogeneous domains within the study area. We employed an existing statistical method for the definition of the cumulated event rainfall vs. rainfall duration (ED) thresholds, for both the entire catalogue of rainfall events and for the events falling in the separated domains. The obtained results contribute to a better understanding of the role exerted by geological, pedological and climatic factors in landslides activation and help identifying separated domains where different risk managing strategies should be adopted. The proposed methodology can be a valid support for risk reduction strategies planning at regional scale.

Molecular responses of genetically modified maize to abiotic stresses as determined through proteomic and metabolomic analyses

PubMed Central

Benevenuto, Rafael Fonseca; Agapito-Tenfen, Sarah Zanon; Vilperte, Vinicius; Wikmark, Odd-Gunnar; van Rensburg, Peet Jansen; Nodari, Rubens Onofre

2017-01-01

Some genetically modified (GM) plants have transgenes that confer tolerance to abiotic stressors. Meanwhile, other transgenes may interact with abiotic stressors, causing pleiotropic effects that will affect the plant physiology. Thus, physiological alteration might have an impact on the product safety. However, routine risk assessment (RA) analyses do not evaluate the response of GM plants exposed to different environmental conditions. Therefore, we here present a proteome profile of herbicide-tolerant maize, including the levels of phytohormones and related compounds, compared to its near-isogenic non-GM variety under drought and herbicide stresses. Twenty differentially abundant proteins were detected between GM and non-GM hybrids under different water deficiency conditions and herbicide sprays. Pathway enrichment analysis showed that most of these proteins are assigned to energetic/carbohydrate metabolic processes. Among phytohormones and related compounds, different levels of ABA, CA, JA, MeJA and SA were detected in the maize varieties and stress conditions analysed. In pathway and proteome analyses, environment was found to be the major source of variation followed by the genetic transformation factor. Nonetheless, differences were detected in the levels of JA, MeJA and CA and in the abundance of 11 proteins when comparing the GM plant and its non-GM near-isogenic variety under the same environmental conditions. Thus, these findings do support molecular studies in GM plants Risk Assessment analyses. PMID:28245233

ARTI refrigerant database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1996-07-01

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

Diversifying the composition and structure of managed late-successional forests with harvest gaps: What is the optimal gap size?

Treesearch

Christel C. Kern; Anthony W. D’Amato; Terry F. Strong

2013-01-01

Managing forests for resilience is crucial in the face of uncertain future environmental conditions. Because harvest gap size alters the species diversity and vertical and horizontal structural heterogeneity, there may be an optimum range of gap sizes for conferring resilience to environmental uncertainty. We examined the impacts of different harvest gap sizes on...

ARTI refrigerant database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1996-11-15

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

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...

Contrasting stress responses of two co-occurring chipmunk species (Tamias alpinus and T. speciosus).

PubMed

Hammond, Talisin T; Palme, Rupert; Lacey, Eileen A

2015-01-15

Glucocorticoid (GC) hormones are important mediators of responses to environmental conditions. Accordingly, differences in GC physiology may contribute to interspecific variation in response to anthropogenically-induced patterns of climate change. To begin exploring this possibility, we validated the use of fecal cortisol/corticosterone metabolites (FCM) to measure baseline glucocorticoid levels in two species of co-occurring chipmunks that have exhibited markedly different patterns of response to environmental change. In Yosemite National Park, the alpine chipmunk (Tamias alpinus) has undergone a significant upward contraction of its elevational range over the past century; in contrast, the lodgepole chipmunk (Tamiasspeciosus) has experienced no significant change in elevational distribution over this period. To determine if GC levels in these species vary in response to external stimuli and to assess whether these responses differ between species, we compared FCM levels for the same individuals (1) at the time of capture in the field, (2) after a short period of captivity, and (3) after adrenocorticotropic hormone (ACTH), (4) handling, and (5) trapping challenges conducted while these animals were held in captivity. Our analyses indicate that T. alpinus was more responsive to several of these changes in external conditions. Although both species displayed a significant FCM response to ACTH challenge, only T. alpinus showed a significant response to our handling challenge and to captive housing conditions. These findings underscore the importance of species-specific validation studies and support the potential for studies of GC physiology to generate insights into interspecific differences in response to environmental change. Copyright © 2014 Elsevier Inc. All rights reserved.

Modelling reveals endogenous osmotic adaptation of storage tissue water potential as an important driver determining different stem diameter variation patterns in the mangrove species Avicennia marina and Rhizophora stylosa.

PubMed

Vandegehuchte, Maurits W; Guyot, Adrien; Hubeau, Michiel; De Swaef, Tom; Lockington, David A; Steppe, Kathy

2014-09-01

Stem diameter variations are mainly determined by the radial water transport between xylem and storage tissues. This radial transport results from the water potential difference between these tissues, which is influenced by both hydraulic and carbon related processes. Measurements have shown that when subjected to the same environmental conditions, the co-occurring mangrove species Avicennia marina and Rhizophora stylosa unexpectedly show a totally different pattern in daily stem diameter variation. Using in situ measurements of stem diameter variation, stem water potential and sap flow, a mechanistic flow and storage model based on the cohesion-tension theory was applied to assess the differences in osmotic storage water potential between Avicennia marina and Rhizophora stylosa. Both species, subjected to the same environmental conditions, showed a resembling daily pattern in simulated osmotic storage water potential. However, the osmotic storage water potential of R. stylosa started to decrease slightly after that of A. marina in the morning and increased again slightly later in the evening. This small shift in osmotic storage water potential likely underlaid the marked differences in daily stem diameter variation pattern between the two species. The results show that in addition to environmental dynamics, endogenous changes in the osmotic storage water potential must be taken into account in order to accurately predict stem diameter variations, and hence growth.

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

PubMed Central

2013-01-01

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

Hormonal Signal Amplification Mediates Environmental Conditions during Development and Controls an Irreversible Commitment to Adulthood

PubMed Central

Schaedel, Oren N.; Gerisch, Birgit; Antebi, Adam; Sternberg, Paul W.

2012-01-01

Many animals can choose between different developmental fates to maximize fitness. Despite the complexity of environmental cues and life history, different developmental fates are executed in a robust fashion. The nematode Caenorhabditis elegans serves as a powerful model to examine this phenomenon because it can adopt one of two developmental fates (adulthood or diapause) depending on environmental conditions. The steroid hormone dafachronic acid (DA) directs development to adulthood by regulating the transcriptional activity of the nuclear hormone receptor DAF-12. The known role of DA suggests that it may be the molecular mediator of environmental condition effects on the developmental fate decision, although the mechanism is yet unknown. We used a combination of physiological and molecular biology techniques to demonstrate that commitment to reproductive adult development occurs when DA levels, produced in the neuroendocrine XXX cells, exceed a threshold. Furthermore, imaging and cell ablation experiments demonstrate that the XXX cells act as a source of DA, which, upon commitment to adult development, is amplified and propagated in the epidermis in a DAF-12 dependent manner. This positive feedback loop increases DA levels and drives adult programs in the gonad and epidermis, thus conferring the irreversibility of the decision. We show that the positive feedback loop canalizes development by ensuring that sufficient amounts of DA are dispersed throughout the body and serves as a robust fate-locking mechanism to enforce an organism-wide binary decision, despite noisy and complex environmental cues. These mechanisms are not only relevant to C. elegans but may be extended to other hormonal-based decision-making mechanisms in insects and mammals. PMID:22505848

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

PubMed Central

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

2014-01-01

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

Target identification using Zernike moments and neural networks

NASA Astrophysics Data System (ADS)

Azimi-Sadjadi, Mahmood R.; Jamshidi, Arta A.; Nevis, Andrew J.

2001-10-01

The development of an underwater target identification algorithm capable of identifying various types of underwater targets, such as mines, under different environmental conditions pose many technical problems. Some of the contributing factors are: targets have diverse sizes, shapes and reflectivity properties. Target emplacement environment is variable; targets may be proud or partially buried. Environmental properties vary significantly from one location to another. Bottom features such as sand, rocks, corals, and vegetation can conceal a target whether it is partially buried or proud. Competing clutter with responses that closely resemble those of the targets may lead to false positives. All the problems mentioned above contribute to overly difficult and challenging conditions that could lead to unreliable algorithm performance with existing methods. In this paper, we developed and tested a shape-dependent feature extraction scheme that provides features invariant to rotation, size scaling and translation; properties that are extremely useful for any target classification problem. The developed schemes were tested on an electro-optical imagery data set collected under different environmental conditions with variable background, range and target types. The electro-optic data set was collected using a Laser Line Scan (LLS) sensor by the Coastal Systems Station (CSS), located in Panama City, Florida. The performance of the developed scheme and its robustness to distortion, rotation, scaling and translation was also studied.

Melanin-specific life-history strategies.

PubMed

Emaresi, Guillaume; Bize, Pierre; Altwegg, Res; Henry, Isabelle; van den Brink, Valentijn; Gasparini, Julien; Roulin, Alexandre

2014-02-01

The maintenance of genetic variation is a long-standing issue because the adaptive value of life-history strategies associated with each genetic variant is usually unknown. However, evidence for the coexistence of alternative evolutionary fixed strategies at the population level remains scarce. Because in the tawny owl (Strix aluco) heritable melanin-based coloration shows different physiological and behavioral norms of reaction, we investigated whether coloration is associated with investment in maintenance and reproduction. Light melanic owls had lower adult survival compared to dark melanic conspecifics, and color variation was related to the trade-off between offspring number and quality. When we experimentally enlarged brood size, light melanic males produced more fledglings but in poorer condition, and they were less often recruited in the local breeding population than those of darker melanic conspecifics. Our results also suggest that dark melanic males allocate a constant effort to raise their brood independently of environmental conditions, whereas lighter melanic males finely adjust reproductive effort in relation to changes in environmental conditions. Color traits can therefore be associated with life-history strategies, and stochastic environmental perturbation can temporarily favor one phenotype over others. The existence of fixed strategies implies that some phenotypes can sometimes display a "maladapted" strategy. Long-term population monitoring is therefore vital for a full understanding of how different genotypes deal with trade-offs.

Environmentally Persistent Free Radicals in Soils of Past Coking Sites: Distribution and Stabilization.

PubMed

Jia, Hanzhong; Zhao, Song; Nulaji, Gulimire; Tao, Kelin; Wang, Fu; Sharma, Virender K; Wang, Chuanyi

2017-06-06

This study presents the existence of environmentally persistent free radicals (EPFRs) in soils of past coking sites, mainly contaminated by polycyclic aromatic hydrocarbons (PAHs). Measurements of EPFRs were conducted by electron paramagnetic resonance (EPR) technique with numerous soil samples, which were collected from different distances (0-1000 m) and different depths (0-30 cm) of three contaminant sources. EPR signals with ∼3 × 10 17 radicals/g of the soil samples were obtained, which are very similar to that generated in PAHs contaminated clays, that is, g = 2.0028-2.0036. Concentrations of PAHs and soil components were determined to understand their role in producing EPFRs. PAHs, clay, and iron predominately contributed to generating EPRFs. Meanwhile, organic matter negatively influenced the production of EPRFs. The effects of environmental factors (moisture and oxic/anoxic) were also studied to probe the persistency of EPFRs under various simulated conditions. The EPFRs are stable under relatively dry and oxic conditions. Under anoxic conditions without O 2 and H 2 O, the spin densities decrease initially, followed by gradual increase before attaining constant values in two months period time. The present work implies that continuous formation of EPFRs induced by PAHs is largely responsible for the presence of relatively stable radicals in soils of coking sites.

Early life programming of fear conditioning and extinction in adult male rats.

PubMed

Stevenson, Carl W; Spicer, Clare H; Mason, Rob; Marsden, Charles A

2009-12-28

The early rearing environment programs corticolimbic function and neuroendocrine stress reactivity in adulthood. Although early environmental programming of innate fear has been previously examined, its impact on fear learning and memory later in life remains poorly understood. Here we examined the role of the early rearing environment in programming fear conditioning and extinction in adult male rats. Pups were subjected to maternal separation (MS; 360 min), brief handling (H; 15 min), or animal facility rearing (AFR) on post-natal days 2-14. As adults, animals were tested in a 3-day fear learning and memory paradigm which assessed the acquisition, expression and extinction of fear conditioning to an auditory cue; the recall of extinction was also assessed. In addition, contextual fear was assessed prior to cued extinction and its recall. We found that the acquisition of fear conditioning to the cue was modestly impaired by MS. However, no early rearing group differences were observed in cue-induced fear expression. In contrast, both the rate of extinction and extinction recall were attenuated by H. Finally, although contextual fear was reduced after extinction to the cue, no differences in context-induced fear were observed between the early rearing groups. These results add to a growing body of evidence supporting an important role for early environmental programming of fear conditioning and extinction. They also indicate that different early rearing conditions can program varying effects on distinct fear learning and memory processes in adulthood.

[Identification of the cumulative eco-environment effect of coal-electricity integration based on interpretative structural model].

PubMed

Han, Lin Wei; Fu, Xiao; Yan, Yan; Wang, Chen Xing; Wu, Gang

2017-05-18

In order to determine the cumulative eco-environmental effect of coal-electricity integration, we selected 29 eco-environmental factors including different development and construction activities of coal-electricity integration, soil, water, atmospheric conditions, biology, landscape, and ecology. Literature survey, expert questionnaire and interview were conducted to analyze the interactive relationships between different factors. The structure and correlations between the eco-environmental factors influenced by coal-electricity integration activities were analyzed using interpretive structural modeling (ISM) and the cumulative eco-environment effect of development and construction activities was determined. A research and evaluation framework for the cumulative eco-environmental effect was introduced in addition to specific evaluation and management needs. The results of this study would provide a theoretical and technical basis for planning and management of coal-electricity integration development activities.

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.

Oil Based Drilling Fluid Waste: An Overview on Environmentally Persistent Pollutants

NASA Astrophysics Data System (ADS)

Siddique, Shohel; Kwoffie, Lorraine; Addae-Afoakwa, Kofi; Yates, Kyari; Njuguna, James

2017-05-01

Operational discharges of spent drilling fluid, produced water, and accumulated drill cuttings from oil and gas industry are a continuous point source of environmental pollution. To meet the strict environmental standard for waste disposal, oil and gas industry is facing a numerous challenges in technological development to ensure a clean and safe environment. Oil and gas industry generates a large amount of spent drilling fluid, produced water, and drill cuttings, which are very different in every drilling operation in terms of composition and characterisation. This review article highlights the knowledge gap in identifying the different sources of waste streams in combined drilling waste. This paper also emphasises how different chemicals turn into environmentally significant pollutants after serving great performance in oil and gas drilling operations. For instance, oil based drilling fluid performs excellent in deeper drilling and drilling in the harsh geological conditions, but ended with (produces) a significant amount of persistent toxic pollutants in the environment. This review paper provides an overview on the basic concepts of drilling fluids and their functions, sources and characterisation of drilling wastes, and highlights some environmentally significant elements including different minerals present in drilling waste stream.

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

PubMed Central

2013-01-01

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

Environmental Challenges and Physiological Solutions: Comparative Energetic Daily Rhythms of Field Mice Populations from Different Ecosystems

PubMed Central

Scantlebury, Michael; Haim, Abraham

2012-01-01

Daily and seasonal variations in physiological characteristics of mammals can be considered adaptations to temporal habitat variables. Across different ecosystems, physiological adjustments are expected to be sensitive to different environmental signals such as changes in photoperiod, temperature or water and food availability; the relative importance of a particular signal being dependent on the ecosystem in question. Energy intake, oxygen consumption (VO2) and body temperature (Tb) daily rhythms were compared between two populations of the broad-toothed field mouse Apodemus mystacinus, one from a Mediterranean and another from a sub-Alpine ecosystem. Mice were acclimated to short-day (SD) ‘winter’ and long-day (LD) ‘summer’ photoperiods under different levels of salinity simulating osmotic challenges. Mediterranean mice had higher VO2 values than sub-Alpine mice. In addition, mice exposed to short days had higher VO2 values when given water with a high salinity compared with mice exposed to long days. By comparison, across both populations, increasing salinity resulted in a decreased Tb in SD- but not in LD-mice. Thus, SD-mice may conserve energy by decreasing Tb during (‘winter’) conditions which are expected to be cool, whereas LD-mice might do the opposite and maintain a higher Tb during (‘summer’) conditions which are expected to be warm. LD-mice behaved to reduce energy expenditure, which might be considered a useful trait during ‘summer’ conditions. Overall, increasing salinity was a clear signal for Mediterranean-mice with resultant effects on VO2 and Tb daily rhythms but had less of an effect on sub-Alpine mice, which were more responsive to changes in photoperiod. Results provide an insight into how different populations respond physiologically to various environmental challenges. PMID:23251469

Environmental challenges and physiological solutions: comparative energetic daily rhythms of field mice populations from different ecosystems.

PubMed

Scantlebury, Michael; Haim, Abraham

2012-01-01

Daily and seasonal variations in physiological characteristics of mammals can be considered adaptations to temporal habitat variables. Across different ecosystems, physiological adjustments are expected to be sensitive to different environmental signals such as changes in photoperiod, temperature or water and food availability; the relative importance of a particular signal being dependent on the ecosystem in question. Energy intake, oxygen consumption (VO(2)) and body temperature (T(b)) daily rhythms were compared between two populations of the broad-toothed field mouse Apodemus mystacinus, one from a Mediterranean and another from a sub-Alpine ecosystem. Mice were acclimated to short-day (SD) 'winter' and long-day (LD) 'summer' photoperiods under different levels of salinity simulating osmotic challenges. Mediterranean mice had higher VO(2) values than sub-Alpine mice. In addition, mice exposed to short days had higher VO(2) values when given water with a high salinity compared with mice exposed to long days. By comparison, across both populations, increasing salinity resulted in a decreased T(b) in SD- but not in LD-mice. Thus, SD-mice may conserve energy by decreasing T(b) during ('winter') conditions which are expected to be cool, whereas LD-mice might do the opposite and maintain a higher T(b) during ('summer') conditions which are expected to be warm. LD-mice behaved to reduce energy expenditure, which might be considered a useful trait during 'summer' conditions. Overall, increasing salinity was a clear signal for Mediterranean-mice with resultant effects on VO(2) and T(b) daily rhythms but had less of an effect on sub-Alpine mice, which were more responsive to changes in photoperiod. Results provide an insight into how different populations respond physiologically to various environmental challenges.

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

PubMed

Poller, Christin; Hopster, Klaus; Rohn, Karl; Kästner, Sabine Br

2013-01-08

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

Condition of larval red snapper (Lutjanus campechanus) relative to environmental variability and the Deepwater Horizon oil spill

NASA Astrophysics Data System (ADS)

Hernandez, F. J., Jr.; Filbrun, J. E.; Fang, J.; Ransom, J. T.

2016-09-01

The Deepwater Horizon oil spill (DWHOS) spatially and temporally overlapped with the spawning of many fish species, including Red Snapper, one of the most economically important reef fish in the Gulf of Mexico. To investigate potential impacts of the DWHOS on larval Red Snapper, data from a long-term ichthyoplankton survey off the coast of Alabama were used to examine: (1) larval abundances among pre-impact (2007-2009), impact (2010), and post-impact (2011, 2013) periods; (2) proxies for larval condition (size-adjusted morphometric relationships and dry weight) among the same periods; and (3) the effects of background environmental variation on larval condition. We found that larval Red Snapper were in poorer body condition during 2010, 2011, and 2013 as compared to the 2007-2009 period, a trend that was strongly (and negatively) related to variation in Mobile Bay freshwater discharge. However, larvae collected during and after 2010 were in relatively poor condition even after accounting for variation in freshwater discharge and other environmental variables. By contrast, no differences in larval abundance were detected during these survey years. Taken together, larval supply did not change relative to the timing of the DWHOS, but larval condition was negatively impacted. Even small changes in condition can affect larval survival, so these trends may have consequences for recruitment of larvae to juvenile and adult life stages.

Enduring effects of post-weaning rearing condition on depressive- and anxiety-like behaviors and motor activity in male rats.

PubMed

Mosaferi, Belal; Babri, Shirin; Ebrahimi, Hadi; Mohaddes, Gisou

2015-04-01

Environmental manipulation at early critical periods could have long-lasting effects. In spite of the great interest in the biological effects of the environmental condition so far, its long-lasting effects are less documented. This study looks at the enduring effects of rearing condition on tasks that measure affective responses and exploratory behavior in male Wistar rats. The animals were reared from weaning to adulthood in an enriched environment, standard laboratory condition, or isolated condition. Then, all rats were housed in standard laboratory cages to provide a common environment, and successively exposed to different tests between 0 and 11 weeks post-manipulation. The open field test indicated a more efficient exploratory behavior in the enriched group, and an enhanced spontaneous motor activity in both standard and isolated groups. In addition, rats reared in standard condition showed heightened motor activity in forced swimming test and elevated plus maze. Forced swimming test showed an antidepressive-like effect in the enriched environment group by increased climbing behavior. In respect to the anxiety behavior, environmental enrichment improved threat detection ability. It is concluded that rearing condition from weaning to adulthood has important and long-lasting effects on depressive- and anxiety-like and exploratory behaviors as well as motor activity. Copyright © 2015 Elsevier Inc. All rights reserved.

Suitability of Different Food Grade Materials for the Encapsulation of Some Functional Foods Well Reported for Their Advantages and Susceptibility.

PubMed

Wani, Touseef Ahmed; Shah, Adil Gani; Wani, Sajad Mohd; Wani, Idrees Ahmed; Masoodi, Farooq Ahmad; Nissar, Nazia; Shagoo, Mudasir Ahmad

2016-11-17

Functional foods find a very important place in the modern era, where different types of cancer, diabetes, cardiovascular diseases, etc. are on a high. Irrespective of the abundance of bioactive components in different fruits and vegetables, their low solubility in aqueous solution, vulnerability to destruction in different environmental and gastrointestinal conditions and a low intestinal absorption becomes a concern. Because it is quite difficult to commercialize non food materials for the food encapsulation purposes due to their safety concerns in the human body, scientists in the recent times have come up with the idea of encapsulating the different bioactive components in different food grade materials that are able to safeguard these bioactive components against the different environmental and gastrointestinal conditions and ensure their safe and targeted delivery at their absorption sites. Different food grade encapsulation materials including various oligosaccharides, polysaccharides (starch, cyclodextrins, alginates, chitosan, gum arabic, and carboxymethyl cellulose) and proteins and their suitability for encapsulating various bioactive components like flavonoids (catechins, rutin, curcumin, hesperetin, and vanillin), nonflavonoids (resveratrol), carotenoids (β-carotene, lycopene, and lutein), and fatty acids (fish oil, flaxseed oil, and olive oil) of high medical and nutritional value are reviewed here.

Reconfigurable environmentally adaptive computing

NASA Technical Reports Server (NTRS)

Coxe, Robin L. (Inventor); Galica, Gary E. (Inventor)

2008-01-01

Described are methods and apparatus, including computer program products, for reconfigurable environmentally adaptive computing technology. An environmental signal representative of an external environmental condition is received. A processing configuration is automatically selected, based on the environmental signal, from a plurality of processing configurations. A reconfigurable processing element is reconfigured to operate according to the selected processing configuration. In some examples, the environmental condition is detected and the environmental signal is generated based on the detected condition.

Lake microbial communities are resilient after a whole-ecosystem disturbance

PubMed Central

Shade, Ashley; Read, Jordan S; Youngblut, Nicholas D; Fierer, Noah; Knight, Rob; Kratz, Timothy K; Lottig, Noah R; Roden, Eric E; Stanley, Emily H; Stombaugh, Jesse; Whitaker, Rachel J; Wu, Chin H; McMahon, Katherine D

2012-01-01

Disturbances act as powerful structuring forces on ecosystems. To ask whether environmental microbial communities have capacity to recover after a large disturbance event, we conducted a whole-ecosystem manipulation, during which we imposed an intense disturbance on freshwater microbial communities by artificially mixing a temperate lake during peak summer thermal stratification. We employed environmental sensors and water chemistry analyses to evaluate the physical and chemical responses of the lake, and bar-coded 16S ribosomal RNA gene pyrosequencing and automated ribosomal intergenic spacer analysis (ARISA) to assess the bacterial community responses. The artificial mixing increased mean lake temperature from 14 to 20 °C for seven weeks after mixing ended, and exposed the microorganisms to very different environmental conditions, including increased hypolimnion oxygen and increased epilimnion carbon dioxide concentrations. Though overall ecosystem conditions remained altered (with hypolimnion temperatures elevated from 6 to 20 °C), bacterial communities returned to their pre-manipulation state as some environmental conditions, such as oxygen concentration, recovered. Recovery to pre-disturbance community composition and diversity was observed within 7 (epilimnion) and 11 (hypolimnion) days after mixing. Our results suggest that some microbial communities have capacity to recover after a major disturbance. PMID:22739495

Critical review: Copper runoff from outdoor copper surfaces at atmospheric conditions.

PubMed

Hedberg, Yolanda S; Hedberg, Jonas F; Herting, Gunilla; Goidanich, Sara; Odnevall Wallinder, Inger

2014-01-01

This review on copper runoff dispersed from unsheltered naturally patinated copper used for roofing and facades summarizes and discusses influencing factors, available literature, and predictive models, and the importance of fate and speciation for environmental risk assessment. Copper runoff from outdoor surfaces is predominantly governed by electrochemical and chemical reactions and is highly dependent on given exposure conditions (size, inclination, geometry, degree of sheltering, and orientation), surface parameters (age, patina composition, and thickness), and site-specific environmental conditions (gaseous pollutants, chlorides, rainfall characteristics (amount, intensity, pH), wind direction, temperature, time of wetness, season). The corrosion rate cannot be used to assess the runoff rate. The extent of released copper varies largely between different rain events and is related to dry and wet periods, dry deposition prior to the rain event and prevailing rain and patina characteristics. Interpretation and use of copper runoff data for environmental risk assessment and management need therefore to consider site-specific factors and focus on average data of long-term studies (several years). Risk assessments require furthermore that changes in copper speciation, bioavailability aspects, and potential irreversible retention on solid surfaces are considered, factors that determine the environmental fate of copper runoff from outdoor surfaces.

Influence of Peanut Cultivars and Environmental Conditions on the Diversity and Community Composition of Pod Rot Soil Fungi in China.

PubMed

Wang, Mian; Chen, Mingna; Yang, Zhen; Chen, Na; Chi, Xiaoyuan; Pan, Lijuan; Wang, Tong; Yu, Shanlin; Guo, Xingqi

2017-12-01

Peanut yield and quality are seriously affected by pod rot pathogens worldwide, especially in China in recent years. The goals of this study are to analyze the structure of fungal communities of peanut pod rot in soil in three peanut cultivars and the correlation of pod rot with environmental variables using 454 pyrosequencing. A total of 46,723 internal transcribed spacer high-quality sequences were obtained and grouped into 1,706 operational taxonomic units at the 97% similarity cut-off level. The coverage, rank abundance, and the Chao 1 and Shannon diversity indices of the operational taxonomic units were analyzed. Members of the phylum Ascomycota were dominant, such as Fusarium , Chaetomium , Alternaria , and Sordariomycetes , followed by Basidiomycota. The results of the heatmap and redundancy analysis revealed significant variation in the composition of the fungal community among the three cultivar samples. The environmental conditions in different peanut cultivars may also influence on the structure of the fungal community. The results of this study suggest that the causal agent of peanut pod rot may be more complex, and cultivars and environmental conditions are both important contributors to the community structure of peanut pod rot fungi.

Environmental performance, profitability, asset utilization, debt monitoring and firm value

NASA Astrophysics Data System (ADS)

Bukit, R. Br; Haryanto, B.; Ginting, P.

2018-02-01

The growing issue on firm value shows that firm value is not only determined by the firm ability to increase financial profit, but also by the company's concern in maintaining the environmental condition. The industrial development produces waste that pollutes the environment that has potential to serious impact on the next life. In addition to provide financial benefits, companies are increasingly facing pressure to be socially responsible for the survival of the company. However, past findings demonstrate that the effect of environmental performance, profitability, and asset utilization to the firm’s value are still unclear. This study aims to test whether environmental performance, firm profitability and asset utilization can effectively enhance firm value in two different conditions: intensive debt monitoring and less intensive debt monitoring. Sample of companies is taken from the list of Indonesia Stock Exchange during the period of 2013 to 2015. Using multiple regression analysis, discloses that: in intensive monitoring, managers tend to have high firm value when company has high environmental performance and or high profitability and high asset utilization. Monitoring system needs to be intensified especially for companies with the above characteristics.

Silencing of the ACC synthase gene ACACS2 causes delayed flowering in pineapple [Ananas comosus (L.) Merr.].

PubMed

Trusov, Yuri; Botella, José Ramón

2006-01-01

Flowering is a crucial developmental stage in the plant life cycle. A number of different factors, from environmental to chemical, can trigger flowering. In pineapple, and other bromeliads, it has been proposed that flowering is triggered by a small burst of ethylene production in the meristem in response to environmental cues. A 1-amino-cyclopropane-1-carboxylate synthase (ACC synthase) gene has been cloned from pineapple (ACACS2), which is induced in the meristem under the same environmental conditions that induce flowering. Two transgenic pineapple lines have been produced containing co-suppression constructs designed to down-regulate the expression of the ACACS2 gene. Northern analysis revealed that the ACACS2 gene was silenced in a number of transgenic plants in both lines. Southern hybridization revealed clear differences in the methylation status of silenced versus non-silenced plants by the inability of a methylation-sensitive enzyme to digest within the ACACS2 DNA extracted from silenced plants, indicating that methylation is the cause of the observed co-suppression of the ACACS2 gene. Flowering characteristics of the transgenic plants were studied under field conditions in South East Queensland, Australia. Flowering dynamics studies revealed significant differences in flowering behaviour, with transgenic plants exhibiting silencing showing a marked delay in flowering when compared with non-silenced transgenic plants and control non-transformed plants. It is argued that the ACACS2 gene is one of the key contributors towards triggering 'natural flowering' in mature pineapples under commercial field conditions.

Introducing a novel interaction model structure for the combined effect of temperature and pH on the microbial growth rate.

PubMed

Akkermans, Simen; Noriega Fernandez, Estefanía; Logist, Filip; Van Impe, Jan F

2017-01-02

Efficient modelling of the microbial growth rate can be performed by combining the effects of individual conditions in a multiplicative way, known as the gamma concept. However, several studies have illustrated that interactions between different effects should be taken into account at stressing environmental conditions to achieve a more accurate description of the growth rate. In this research, a novel approach for modeling the interactions between the effects of environmental conditions on the microbial growth rate is introduced. As a case study, the effect of temperature and pH on the growth rate of Escherichia coli K12 is modeled, based on a set of computer controlled bioreactor experiments performed under static environmental conditions. The models compared in this case study are the gamma model, the model of Augustin and Carlier (2000), the model of Le Marc et al. (2002) and the novel multiplicative interaction model, developed in this paper. This novel model enables the separate identification of interactions between the effects of two (or more) environmental conditions. The comparison of these models focuses on the accuracy, interpretability and compatibility with efficient modeling approaches. Moreover, for the separate effects of temperature and pH, new cardinal parameter model structures are proposed. The novel interaction model contributes to a generic modeling approach, resulting in predictive models that are (i) accurate, (ii) easily identifiable with a limited work load, (iii) modular, and (iv) biologically interpretable. Copyright © 2016. Published by Elsevier B.V.

The Social, Historical, and Institutional Contingencies of Dam Removal

NASA Astrophysics Data System (ADS)

Magilligan, F. J.; Sneddon, C. S.; Fox, C. A.

2017-06-01

Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical-geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical-geographical conditions and broader institutional networks of power and influence.

The Social, Historical, and Institutional Contingencies of Dam Removal.

PubMed

Magilligan, F J; Sneddon, C S; Fox, C A

2017-06-01

Environmental managers in the United States and elsewhere are increasingly perceiving dam removal as a critical tool for river restoration and enhancing watershed resilience. In New England, over 125 dams have been dismantled for ecological and economic rationales. A surprising number of these removals, including many that are ongoing, have generated heated conflicts between restoration proponents and local communities who value their dammed landscapes. Using a comparative case study approach, we examine the environmental conflict around efforts to remove six dams in New England. Each of these removal efforts followed quite different paths and resultant outcomes: successful removal, stalled removal, and failure despite seemingly favorable institutional conditions. Lengthy conflicts often transpired in instances where removals occurred, but these were successfully arbitrated by paying attention to local historical-geographical conditions conducive to removal and by brokering effective compromises between dam owners and the various local actors and stakeholders involved in the removal process. Yet our results across all cases suggest that these are necessary, but not sufficient conditions for restoration through dam removal since a similar set of conditions typified cases where removals are continuously stalled or completely halted. Scholars examining the intersection between ecological restoration and environmental politics should remain vigilant in seeking patterns and generalities across cases of environmental conflict in order to promote important biophysical goals, but must also remain open to the ways in which those goals are thwarted and shaped by conflicts that are deeply contingent on historical-geographical conditions and broader institutional networks of power and influence.

Working conditions, psychosocial environmental factors, and depressive symptoms among wage workers in South Korea.

PubMed

Sohn, Minsung; Choi, Mankyu; Jung, Minsoo

2016-07-01

In South Korea, the number of workers suffering from mental illnesses, such as depression, has rapidly increased. There is growing concern about depressive symptoms being associated with both working conditions and psychosocial environmental factors. To investigate potential psychosocial environmental moderators in the relationship between working conditions and occupational depressive symptoms among wage workers. Data were obtained from the wage worker respondents (n = 4,095) of the Korean National Health and Nutrition Examination Survey of 2009. First, chi-square tests confirmed the differences in working conditions and psychosocial characteristics between depressive and non-depressive groups. Second, multivariate logistic regression analysis was performed to examine the moderating effects of the psychosocial environmental factors between working conditions and depressive symptoms. After adjusting for potential covariates, the likelihood of depressive symptomatology was high among respondents who had dangerous jobs and flexible work hours compared to those who had standard jobs and fixed daytime work hours (OR = 1.66 and 1.59, respectively). Regarding psychosocial factors, respondents with high job demands, low job control, and low social support were more likely to have depressive symptoms (OR = 1.26, 1.58 and 1.61, respectively). There is a need to develop non-occupational intervention programs, which provide workers with training about workplace depression and improve social support, and the programs should provide time for employees to have active communication. Additionally, companies should provide employees with support to access mental healthcare thereby decreasing the occurrence of workplace depression.

Spatial memory enhances the evacuation efficiency of virtual pedestrians under poor visibility condition

NASA Astrophysics Data System (ADS)

Ma, Yi; Lee, Eric Wai Ming; Shi, Meng; Kwok Kit Yuen, Richard

2018-03-01

Spatial memory is a critical navigation support tool for disoriented evacuees during evacuation under adverse environmental conditions such as dark or smoky conditions. Owing to the complexity of memory, it is challenging to understand the effect of spatial memory on pedestrian evacuation quantitatively. In this study, we propose a simple method to quantitatively represent the evacueeʼs spatial memory about the emergency exit, model the evacuation of pedestrians under the guidance of the spatial memory, and investigate the effect of the evacueeʼs spatial memory on the evacuation from theoretical and physical perspectives. The result shows that (i) a good memory can significantly assist the evacuation of pedestrians under poor visibility conditions, and the evacuation can always succeed when the degree of the memory exceeds a threshold (\\varphi > 0.5); (ii) the effect of memory is superior to that of “follow-the-crowd” under the same environmental conditions; (iii) in the case of multiple exits, the difference in the degree of the memory between evacuees has a significant effect (the greater the difference, the faster the evacuation) for the evacuation under poor visibility conditions. Our study provides a new quantitative insight into the effect of spatial memory on crowd evacuation under poor visibility conditions. Project supported by the Research Grants Council of the Hong Kong Special Administrative Region, China (Grant No. 11203615).

Growth and physiological responses of isohydric and anisohydric poplars to drought

Treesearch

Ziv Attia; Jean-Christophe Domec; Ram Oren; Danielle A. Way; Menachem Moshelion

2015-01-01

Understanding how different plants prioritize carbon gain and drought vulnerability under a variable water supply is important for predicting which trees will maximize woody biomass production under different environmental conditions. Here, Populus balsamifera (BS, isohydric genotype), P. simonii (SI, previously uncharacterized stomatal behaviour), and their cross, P....

Assessing the Exposure and Relative Sensitivity of Native Freshwater Mussels to Environmental Stressors and Laboratory Conditions

EPA Science Inventory

1. Expands the database for pesticide toxicity on native freshwater mussels. 2. Aids in determining any potential differences in toxic sensitivity of gravid female mussel attributed to age and laboratory holding times. 3. Aids in determining potential differences in juvenile ...

Water Quality Perceptions and Attitudes

ERIC Educational Resources Information Center

Ditton, Robert B.; Goodale, Thomas L.

1974-01-01

An extensive survey of the marine recreational uses of the Bay of Green Bay was conducted to determine the knowledge, perception, and attitudes of adjacent populations. Findings indicated that environmental forces and problems are not well understood and that the condition of Green Bay is perceived differently by different users. (Author/MA)

ARTI refrigerant database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1998-03-15

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to thermophysical properties, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air conditioning and refrigeration equipment. It also references documents addressing compatibility ofmore » refrigerants and lubricants with other materials.« less

Contextual influences on environmental concerns cross-nationally: A multilevel investigation.

PubMed

Marquart-Pyatt, Sandra T

2012-09-01

Environmental issues continue to grow in international prominence, as environmental conditions are recognized as some of the most important problems facing the world. Research examining this globalization of environmental concern shown in public opinion surveys emphasizes the importance of context yet is currently underspecified. To address this gap, this research uses a multi-level, cross-national study to examine individual-level and country-level influences on three measures of environmental concern: environmental threat awareness, environmental efficacy, and willingness to pay. At the individual level, education, age, and gender affect environmental concerns. At the national level, economic, political, and environmental factors affect environmental concerns. Importantly, contextual factors differ in their effects depending on the dimension of environmental concern measured. Results from cross-level interactions for education confirm these complexities across these measures, supporting a dimensionality argument. The importance of the measurement of environmental concern shown in this research is emphasized for future cross-national scholarship. Copyright © 2012 Elsevier Inc. All rights reserved.

A global comparative analysis of the feeding dynamics and environmental conditions of larval tunas, mackerels, and billfishes

NASA Astrophysics Data System (ADS)

Llopiz, Joel K.; Hobday, Alistair J.

2015-03-01

Scombroid fishes, including tunas, mackerels, and billfishes, constitute some of the most important fisheries in lower latitudes around the world. Though the early life stages of these taxa are relatively well-studied, worldwide patterns in larval feeding dynamics and how such patterns relate to environmental conditions are poorly resolved. We present a synthesis of feeding success (i.e. feeding incidences) and diets of larval scombroids from around the world, and relate these results to water column and sea surface properties for the several regions in which larval feeding studies have been conducted. Feeding success of larval tunas was shown to be distinctly different among regions. In some locations (the Straits of Florida and the Mediterranean Sea), nearly no larvae had empty guts, whereas in other locations (the Gulf of California and off NW Australia) 40-60% of larvae were empty. Diets were consistently narrow in each region (dominated by cyclopoid copepods, appendicularians, nauplii, and other fish larvae), and were usually, but not always, similar for a given scombroid taxon among regions (though diets differed among taxa). Larval habitat conditions were often similar among the 9 regions examined, but some clear differences included low levels of eddy kinetic energy and cooler waters (at the surface and at depth) in the Mediterranean, and lower chlorophyll concentrations around the Nansei Islands, Japan and off NW Australia where feeding success was low. When observed zooplankton abundances are also taken into account, the compiled results on feeding and environmental conditions indicate a bottom-up influence on feeding success. Moreover, the variability among regions highlights the potential for region-specific mechanisms regulating larval survival and, ultimately, levels of adult recruitment.

ARADISH - Development of a Standardized Plant Growth Chamber for Experiments in Gravitational Biology Using Ground Based Facilities

NASA Astrophysics Data System (ADS)

Schüler, Oliver; Krause, Lars; Görög, Mark; Hauslage, Jens; Kesseler, Leona; Böhmer, Maik; Hemmersbach, Ruth

2016-06-01

Plant development strongly relies on environmental conditions. Growth of plants in Biological Life Support Systems (BLSS), which are a necessity to allow human survival during long-term space exploration missions, poses a particular problem for plant growth, as in addition to the traditional environmental factors, microgravity (or reduced gravity such as on Moon or Mars) and limited gas exchange hamper plant growth. Studying the effects of reduced gravity on plants requires real or simulated microgravity experiments under highly standardized conditions, in order to avoid the influence of other environmental factors. Analysis of a large number of biological replicates, which is necessary for the detection of subtle phenotypical differences, can so far only be achieved in Ground Based Facilities (GBF). Besides different experimental conditions, the usage of a variety of different plant growth chambers was a major factor that led to a lack of reproducibility and comparability in previous studies. We have developed a flexible and customizable plant growth chamber, called ARAbidopsis DISH (ARADISH), which allows plant growth from seed to seedling, being realized in a hydroponic system or on Agar. By developing a special holder, the ARADISH can be used for experiments with Arabidopsis thaliana or a plant with a similar habitus on common GBF hardware, including 2D clinostats and Random Positioning Machines (RPM). The ARADISH growth chamber has a controlled illumination system of red and blue light emitting diodes (LED), which allows the user to apply defined light conditions. As a proof of concept we tested a prototype in a proteomic experiment in which plants were exposed to simulated microgravity or a 90° stimulus. We optimized the design and performed viability tests after several days of growth in the hardware that underline the utility of ARADISH in microgravity research.

Environmental Factors Can Influence Mitochondrial Inheritance in the Saccharomyces Yeast Hybrids.

PubMed

Hsu, Yu-Yi; Chou, Jui-Yu

2017-01-01

Mitochondria play a critical role in the generation of metabolic energy and are crucial for eukaryotic cell survival and proliferation. In most sexual eukaryotes, mitochondrial DNA (mtDNA) is inherited from only one parent in non-Mendelian inheritance in contrast to the inheritance of nuclear DNA. The model organism Saccharomyces cerevisiae is commonly used to study mitochondrial biology. It has two mating types: MATa and MATα. Previous studies have suggested that the mtDNA inheritance patterns in hybrid diploid cells depend on the genetic background of parental strains. However, the underlying mechanisms remain unclear. To elucidate the mechanisms, we examined the effects of environmental factors on the mtDNA inheritance patterns in hybrids obtained by crossing S. cerevisiae with its close relative S. paradoxus. The results demonstrated that environmental factors can influence mtDNA transmission in hybrid diploids, and that the inheritance patterns are strain dependent. The fitness competition assay results showed that the fitness differences can explain the mtDNA inheritance patterns under specific conditions. However, in this study, we found that fitness differences cannot fully be explained by mitochondrial activity in hybrids under stress conditions.

Effect of Environment on Fatigue Behavior of a Nicalon(TM)/Si-N-C Ceramic Matrix Composite

NASA Technical Reports Server (NTRS)

Kalluri, Sreeramesh; Ojard, Greg C.; Verrilli, Michael J.; Kiraly, Louis J. (Technical Monitor)

2002-01-01

The effect of environmental exposure on the fatigue life of Nicalon(TM) /Si-N-C composite was investigated in this study. Test specimens with arrays of 1.8 mm diameter holes and two different open areas, 25 and 35%, were machined. Three environmental conditions were studied: 1) continuous fatigue cycling in air, 2) fatigue cycling in air alternating with humidity exposure, and 3) fatigue cycling in air alternating with exposure to a salt-fog environment. All fatigue testing on specimens with holes was performed with a load ratio, R = 0.05, and at a temperature of 910 C. In general, fatigue lives were shortest for specimens subjected to salt-fog exposure and longest for specimens subjected to continuous fatigue cycling in air. The fatigue data generated on the specimens with holes were compared with fatigue data generated in air on specimens with no holes. Fatigue strength reduction factors for different environmental conditions and open areas investigated in the study were calculated for the Nicalon(TM) /Si-N-C composite.

Do priority effects outweigh environmental filtering in a guild of dominant freshwater macroinvertebrates?

PubMed

Little, Chelsea J; Altermatt, Florian

2018-04-11

Abiotic conditions have long been considered essential in structuring freshwater macroinvertebrate communities. Ecological drift, dispersal and biotic interactions also structure communities, and although these mechanisms are more difficult to detect, they may be of equal importance in natural communities. Here, we hypothesized that in 10 naturally replicated headwater streams in eastern Switzerland, locally dominant amphipod species would be associated with differences in environmental conditions. We conducted repeated surveys of amphipods and used a hierarchical joint species distribution model to assess the influence of different drivers on species co-occurrences. The species had unique environmental requirements, but a distinct spatial structure in their distributions was unrelated to habitat. Species co-occurred much less frequently than predicted by the model, which was surprising because laboratory and field evidence suggests they are capable of coexisting in equal densities. We suggest that niche preemption may limit their distribution and that a blocking effect related to the specific linear configuration of streams determines which species colonizes and dominates a given stream catchment, thus suggesting a new solution a long-standing conundrum in freshwater ecology. © 2018 The Author(s).

Local environmental context conditions the impact of Russian olive in a heterogeneous riparian ecosystem

USGS Publications Warehouse

Tuttle, Graham M.; Katz, Gabrielle L.; Friedman, Jonathan M.; Norton, Andrew P.

2016-01-01

Local abiotic and biotic conditions can alter the strength of exotic species impacts. To better understand the effects of exotic species on invaded ecosystems and to prioritize management efforts, it is important that exotic species impacts are put in local environmental context. We studied how differences in plant community composition, photosynthetically active radiation (PAR), and available soil N associated with Russian olive presence are conditioned by local environmental variation within a western U.S. riparian ecosystem. In four sites along the South Fork of the Republican River in Colorado, we established 200 pairs of plots (underneath and apart from Russian olive) to measure the effects of invasion across the ecosystem. We used a series of a priori mixed models to identify environmental variables that altered the effects of Russian olive. For all response variables, models that included the interaction of environmental characteristics, such as presence/absence of an existing cottonwood canopy, with the presence/absence of Russian olive canopy were stronger candidate models than those that just included Russian olive canopy presence as a factor. Compared with reference plots outside of Russian olive canopy, plots underneath Russian olive had higher relative exotic cover (exotic/total cover), lower perennial C4 grass cover, and higher perennial forb cover. These effects were reduced, however, in the presence of a cottonwood canopy. As expected, Russian olive was associated with reduced PAR and increased N, but these effects were reduced under cottonwood canopy. Our results demonstrate that local abiotic and biotic environmental factors condition the effects of Russian olive within a heterogeneous riparian ecosystem and suggest that management efforts should be focused in open areas where Russian olive impacts are strongest.

A short-term in situ CO2 enrichment experiment on Heron Island (GBR)

PubMed Central

Kline, David I.; Teneva, Lida; Schneider, Kenneth; Miard, Thomas; Chai, Aaron; Marker, Malcolm; Headley, Kent; Opdyke, Brad; Nash, Merinda; Valetich, Matthew; Caves, Jeremy K.; Russell, Bayden D.; Connell, Sean D.; Kirkwood, Bill J.; Brewer, Peter; Peltzer, Edward; Silverman, Jack; Caldeira, Ken; Dunbar, Robert B.; Koseff, Jeffrey R.; Monismith, Stephen G.; Mitchell, B. Greg; Dove, Sophie; Hoegh-Guldberg, Ove

2012-01-01

Ocean acidification poses multiple challenges for coral reefs on molecular to ecological scales, yet previous experimental studies of the impact of projected CO2 concentrations have mostly been done in aquarium systems with corals removed from their natural ecosystem and placed under artificial light and seawater conditions. The Coral–Proto Free Ocean Carbon Enrichment System (CP-FOCE) uses a network of sensors to monitor conditions within each flume and maintain experimental pH as an offset from environmental pH using feedback control on the injection of low pH seawater. Carbonate chemistry conditions maintained in the −0.06 and −0.22 pH offset treatments were significantly different than environmental conditions. The results from this short-term experiment suggest that the CP-FOCE is an important new experimental system to study in situ impacts of ocean acidification on coral reef ecosystems. PMID:22639723

The Effects of Different Types of Environmental Noise on Academic Performance and Perceived Task Difficulty in Adolescents With ADHD.

PubMed

Batho, Lauren P; Martinussen, Rhonda; Wiener, Judith

2015-07-28

To examine the effects of environmental noises (speech and white noise) relative to a no noise control condition on the performance and difficulty ratings of youth with ADHD (N = 52) on academic tasks. Reading performance was measured by an oral retell (reading accuracy) and the time spent reading. Writing performance was measured through the proportion of correct writing sequences (writing accuracy) and the total words written on an essay. Participants in the white noise condition took less time to read the passage and wrote more words on the essay compared with participants in the other conditions, though white noise did not improve academic accuracy. The participants in the babble condition rated the tasks as most difficult. Although white noise appears to improve reading time and writing fluency, the findings suggest that white noise does not improve performance accuracy. Educational implications are discussed. © 2015 SAGE Publications.

Evaluation of wheat growth, morphological characteristics, biomass yield and quality in Lunar Palace-1, plant factory, green house and field systems

NASA Astrophysics Data System (ADS)

Dong, Chen; Shao, Lingzhi; Fu, Yuming; Wang, Minjuan; Xie, Beizhen; Yu, Juan; Liu, Hong

2015-06-01

Wheat (Triticum aestivum L.) is one of the most important agricultural crops in both space such as Bioregenerative Life Support Systems (BLSS) and urban agriculture fields, and its cultivation is affected by several environmental factors. The objective of this study was to investigate the influences of different environmental conditions (BLSS, plant factory, green house and field) on the wheat growth, thousand kernel weight (TKW), harvest index (HI), biomass yield and quality during their life cycle. The results showed that plant height partially influenced by the interaction effects with environment, and this influence decreased gradually with the plant development. It was found that there was no significant difference between the BLSS and plant factory treatments on yields per square, but the yield of green house and field treatments were both lower. TKW and HI in BLSS and plant factory were larger than those in the green house and field. However, grain protein concentration can be inversely correlated with grain yield. Grain protein concentrations decreased under elevate CO2 condition and the magnitude of the reductions depended on the prevailing environmental condition. Conditional interaction effects with environment also influenced the components of straw during the mature stage. It indicated that CO2 enriched environment to some extent was better for inedible biomass degradation and had a significant effect on "source-sink flow" at grain filling stage, which was more beneficial to recycle substances in the processes of the environment regeneration.

Wood structural differences between northern and southern beech provenances growing at a moderate site.

PubMed

Eilmann, B; Sterck, F; Wegner, L; de Vries, S M G; von Arx, G; Mohren, G M J; den Ouden, J; Sass-Klaassen, U

2014-08-01

Planting provenances originating from southern to northern locations has been discussed as a strategy to speed up species migration and mitigate negative effects of climate change on forest stability and productivity. Especially for drought-susceptible species such as European beech (Fagus sylvatica L.), the introduction of drought-tolerant provenances from the south could be an option. Yet, beech has been found to respond plastically to environmental conditions, suggesting that the climate on the plantation site might be more important for tree growth than the genetic predisposition of potentially drought-adapted provenances. In this study, we compared the radial growth, wood-anatomical traits and leaf phenology of four beech provenances originating from southern (Bulgaria, France) and northern locations (Sweden, the Netherlands) and planted in a provenance trial in the Netherlands. The distribution of precipitation largely differs between the sites of origin. The northern provenances experience a maximum and the southern provenances experience a minimum of rainfall in summer. We compared tree productivity and the anatomy of the water-conducting system for the period from 2000 to 2010, including the drought year 2003. In addition, tree mortality and the timing of leaf unfolding in spring were analysed for the years 2001, 2007 and 2012. Comparison of these traits in the four beech provenances indicates the influence of genetic predisposition and local environmental factors on the performance of these provenances under moderate site conditions. Variation in radial growth was controlled by environment, although the growth level slightly differed due to genetic background. The Bulgarian provenance had an efficient water-conducting system which was moreover unaffected by the drought in 2003, pointing to a high ability of this provenance to cope well with dry conditions. In addition, the Bulgarian provenance showed up as most productive in terms of height and radial growth. Altogether, we conclude that the similarity in ring-width variation among provenances points to environmental control of this trait, whereas the differences encountered in wood-anatomical traits between the well-performing Bulgarian provenance and the other three provenances, as well as the consistent differences in flushing pattern over 3 years under various environmental conditions, support the hypothesis of genetic control of these features. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Environmental, health and economic conditions perceived by 50 rural communities in Bangladesh.

PubMed

Ohtsuka, Ryutaro; Inaoka, Tsukasa; Moji, Kazuhiko; Karim, Enamul; Yoshinaga, Mari

2002-12-01

For randomly selected 50 villages in Bangladesh, an interview survey with a structured questionnaire was conducted to reveal their perception on the environmental, health and economic conditions at present and for the past 10-year change. The eight following items were analyzed in this paper: air pollution and water pollution, which represent environmental conditions with close relation to health conditions, soil degradation and deforestation, which represent environmental conditions with close relation to economic conditions, epidemic diseases and malnutrition, which represent health conditions, and poverty and jobless, which represent economic conditions. Among the 50 villages, deforestation was most frequently perceived serious at present and worsened in the past 10 years. Of the remaining seven items, those related to economic conditions were more seriously perceived than those related to health and environmental conditions. As revealed by the cluster analysis for the inter-item relations, epidemic diseases, which formed the same cluster with the environmental items, were recognized less serious whereas malnutrition, which formed the same cluster with the economic items, was recognized more serious. These findings are useful not only for rural development programs but also for mitigation programs toward health and environmental hazards in Bangladesh.

Floodplain complexity and surface metrics: influences of scale and geomorphology

USGS Publications Warehouse

Scown, Murray W.; Thoms, Martin C.; DeJager, Nathan R.

2015-01-01

Many studies of fluvial geomorphology and landscape ecology examine a single river or landscape, thus lack generality, making it difficult to develop a general understanding of the linkages between landscape patterns and larger-scale driving variables. We examined the spatial complexity of eight floodplain surfaces in widely different geographic settings and determined how patterns measured at different scales relate to different environmental drivers. Floodplain surface complexity is defined as having highly variable surface conditions that are also highly organised in space. These two components of floodplain surface complexity were measured across multiple sampling scales from LiDAR-derived DEMs. The surface character and variability of each floodplain were measured using four surface metrics; namely, standard deviation, skewness, coefficient of variation, and standard deviation of curvature from a series of moving window analyses ranging from 50 to 1000 m in radius. The spatial organisation of each floodplain surface was measured using spatial correlograms of the four surface metrics. Surface character, variability, and spatial organisation differed among the eight floodplains; and random, fragmented, highly patchy, and simple gradient spatial patterns were exhibited, depending upon the metric and window size. Differences in surface character and variability among the floodplains became statistically stronger with increasing sampling scale (window size), as did their associations with environmental variables. Sediment yield was consistently associated with differences in surface character and variability, as were flow discharge and variability at smaller sampling scales. Floodplain width was associated with differences in the spatial organization of surface conditions at smaller sampling scales, while valley slope was weakly associated with differences in spatial organisation at larger scales. A comparison of floodplain landscape patterns measured at different scales would improve our understanding of the role that different environmental variables play at different scales and in different geomorphic settings.

Soils as records of past and present environments

NASA Astrophysics Data System (ADS)

Sauer, Daniela

2015-04-01

This contribution reflects selected pedological concepts that are helpful for interpreting soil properties related to past and present environments. These concepts are illustrated by examples from various landscapes, and their combination finally leads to some further conclusions. The concept of Targulian and Gerasimova (2009) distinguishes soil system and soil body. Soil system is defined as "open multiphase system functioning in any solid-phase substrate at its interface with the atmosphere, hydrosphere and biota", and soil body as "solid-phase part of a soil system produced by its long-term functioning and composed of a vertical sequence of genetic horizons". Soil system functioning corresponds to the recent environmental factors and includes heat and moisture dynamics, biomass production, biogeochemical cycles, and other processes. In contrast, a soil body is a record of the long-term functioning of a soil system. It thus provides a record not only of the functioning of the soil system under the present environmental conditions but also under past, possibly different, conditions. Hence, Targulian and Goryachkin (2004) called it the "memory" of the landscape. Richter and Yaalon (2012) argued that most soils comprise both, features that developed under the present environmental conditions and features that reflect different conditions that the soils experienced in the past; they concluded that most soils are polygenetic. Although the current functioning of the soil system in the concept of Targulian and Gerasimova (2009) is mainly controlled by the present-day combination of environmental factors, it should be added that past processes also influence the soil system, because past processes changed the soil properties in a way that also the present-day functioning of the soil system is affected by these changes. Earlier, Yaalon (1971) had categorised soil properties according to the time-span required for their adjustment to the actual environment, distinguishing (i) rapidly adjusting soil properties (adjusting within some hundreds of years), (ii) slowly adjusting soil properties (adjusting within some thousands of years), and (iii) persistent soil properties (showing no changes over ten thousands to millions of years). In a polygenetic soil, rapidly adjusting soil properties may already be in equilibrium with the present conditions, whereas slowly adjusting soil properties may still reflect past conditions. Thus, the lower the rate at which a certain soil property in a polygenetic soil adjusts, the larger is the extent to which this property is still determined by earlier environmental conditions. Knowledge on the rates at which soil properties adjust may hence be used to estimate the time at which a significant environmental change took place, based on the degree of overprinting of the different kinds of soil properties adjusting at different rates in a polygenetic soil. References: Richter, D. de B., Yaalon, D.H., 2012. "The changing model of soil" revisited. Soil Sci. Soc. Am. J. 76, 766-778. Targulian, V. O., Goryachkin, S. V., 2004. Soil memory: Types of records, carriers, hierarchy and diversity. Revista Mexicana Ciencias Geol. 21, 1-8. Targulian, V.O., Gerasimova, M., 2009. Soil geography: geography of soil systems and soil bodies. Soil Geography: New Horizons. International Conference, 16-20 November 2009 in Huatulco, Mexico. Book of abstracts, 39. Yaalon, D.H., 1971. Soil forming processes in time and space. In: Yaalon, D.H. (Ed.), Paleopedology-origin, nature and dating of paleosols. Int. Soc. Soil Sci. and Israel Univ. Press, Jerusalem, pp. 29-39.

Benthic macroinvertebrate assemblages and their relations with environmental variables in the Sacramento and San Joaquin River drainages, California, 1993-1997

USGS Publications Warehouse

Brown, Larry R.; May, Jason T.

2000-01-01

Data were collected in the San Joaquin and Sacramento river drainages to evaluate associations between macroinvertebrate assemblages and environmental variables as part of the National Water-Quality Assessment Program of the U.S. Geological Survey. Samples were collected at 53 sites from 1993 to 1995 in the San Joaquin River drainage and in 1996 and 1997 in the Sacramento River drainage. Macroinvertebrates were collected from riffles or from large woody debris (snags) when riffles were absent. Macroinvertebrate taxa were aggregated to the family (or higher) level of taxonomic organization, resulting in 81 taxa for analyses. Only the 50 most common taxa were used for two-way indicator species analysis (TWINSPAN) and canonical correspondence analysis. TWINSPAN analysis defined four groups of riffle samples and four groups of snag samples based on macroinvertebrate assemblages. Analysis of variance identified differences in environmental and biotic characteristics of the groups. These results combined with the results of canonical correspondence analysis indicated that patterns in riffle sample assemblage structure were highly correlated with a gradient in physical and chemical conditions associated with elevation. The results also suggested that flow regulation associated with large storage reservoirs has negative effects on the total number of taxa and density of macroinvertebrates below foothill dams. Analysis of the snag samples showed that, although elevation remained a significant variable, mean dominant substrate size, gradient, specific conductance, water temperature, percentage of the basin in agricultural land use, and percentage of the basin in combined agricultural and urban land uses were more important factors in explaining assemblage structure. Macroinvertebrate assemblages on snags may be useful in family level bioassessments of environmental conditions in valley floor habitats. In the Sierra Nevada and its foothills, the strong influence of elevation made it difficult to attribute differences in macroinvertebrate assemblage structure among sites to specific environmental conditions. Additional work is needed in the foothills and Sierra Nevada to better define macroinvertebrate assemblages and their relations to environmental variables.

Seasonal monitoring of blue mussel (Mytilus spp.) populations in a harbor area: A focus on responses to environmental factors and chronic contamination.

PubMed

Lacroix, C; Duvieilbourg, E; Guillou, N; Guyomarch, J; Bassoulet, C; Moraga, D; Chapalain, G; Auffret, M

2017-08-01

Coastal waters corresponding to macrotidal systems are among the most variable marine biotopes. Sessile animals as bivalve mollusks may however be found forming intertidal beds at high densities, as allowed by full adaptation to local conditions. A better knowledge of adaptive responses to environmental factors is required to foresee possible adverse effects of global change. At the sub-cellular level, transcriptional responses are among the earliest signals of environmental disturbances and they can reveal subtle and meaningful changes in organism exposed to stress. Three blue mussel (Mytilus spp.) populations inhabiting the Bay of Brest (France) in sites exposed to different levels of chronic pollution, from low to moderate, were surveyed upon a seasonal schedule, with special attention to the reproductive cycle. Major seawater parameters were monitored over a full-year in the framework of the S!RANO project, based on an automatic high frequency acquisition system installed aboard a ship of opportunity. The health status of mussels has been assessed by measuring a condition index and gametogenesis has been followed by histology. Selected biological responses to environmental stress were detected using a multimarker approach including expression of genes involved in chemical stress response and energetic metabolism, and cellular immune parameters. Environmental parameters showed deep seasonal variations which differed among sites. Most biological responses followed a seasonal pattern. Late winter and spring corresponded to an active reproduction period in the Bay of Brest. Earlier spawning was observed in harbor areas compared to the oceanic site and an altered physiological state was assumed in commercial harbor mussels during the reproductive period, suggesting that their health is compromised at this time of year. However, no signs of severe chemical stress were detected in both harbor mussel populations, which could reflect adaptive responses to adverse environmental conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Arrested embryonic development: a review of strategies to delay hatching in egg-laying reptiles

PubMed Central

Rafferty, Anthony R.; Reina, Richard D.

2012-01-01

Arrested embryonic development involves the downregulation or cessation of active cell division and metabolic activity, and the capability of an animal to arrest embryonic development results in temporal plasticity of the duration of embryonic period. Arrested embryonic development is an important reproductive strategy for egg-laying animals that provide no parental care after oviposition. In this review, we discuss each type of embryonic developmental arrest used by oviparous reptiles. Environmental pressures that might have directed the evolution of arrest are addressed and we present previously undiscussed environmentally dependent physiological processes that may occur in the egg to bring about arrest. Areas for future research are proposed to clarify how ecology affects the phenotype of developing embryos. We hypothesize that oviparous reptilian mothers are capable of providing their embryos with a level of phenotypic adaptation to local environmental conditions by incorporating maternal factors into the internal environment of the egg that result in different levels of developmental sensitivity to environmental conditions after they are laid. PMID:22438503

Characterization of the Decision Network for Wing Expansion in Drosophila Using Targeted Expression of the TRPM8 Channel

PubMed Central

Peabody, Nathan C.; Pohl, Jascha B.; Diao, Fengqiu; Vreede, Andrew P.; Sandstrom, David J.; Wang, Howard; Zelensky, Paul K.; White, Benjamin H.

2009-01-01

After emergence, adult flies and other insects select a suitable perch and expand their wings. Wing expansion is governed by the hormone bursicon and can be delayed under adverse environmental conditions. How environmental factors delay bursicon release and alter perch selection and expansion behaviors has not been investigated in detail. Here we provide evidence that in Drosophila the motor programs underlying perch selection and wing expansion have different environmental dependencies. Using physical manipulations, we demonstrate that the decision to perch is based primarily on environmental valuations and is incrementally delayed under conditions of increasing perturbation and confinement. In contrast, the all-or-none motor patterns underlying wing expansion are relatively invariant in length regardless of environmental conditions. Using a novel technique for targeted activation of neurons, we show that the highly stereotyped wing expansion motor patterns can be initiated by stimulation of NCCAP, a small network of central neurons that regulates the release of bursicon. Activation of this network using the cold-sensitive rat TRPM8 channel is sufficient to trigger all essential behavioral and somatic processes required for wing expansion. The delay of wing expansion under adverse circumstances thus couples an environmentally-sensitive decision network to a command-like network that initiates a fixed action pattern. Because NCCAP mediates environmentally-insensitive ecdysis-related behaviors in Drosophila development prior to adult emergence, the study of wing expansion promises insights not only into how networks mediate behavioral choices, but also into how decision networks develop. PMID:19295141

A comparative analysis of benthic nematode assemblages from Zostera noltii beds before and after a major vegetation collapse

NASA Astrophysics Data System (ADS)

Materatski, Patrick; Vafeiadou, Anna-Maria; Ribeiro, Rui; Moens, Tom; Adão, Helena

2015-12-01

Benthic nematodes are widely regarded as very suitable organisms to monitor potential ecological effects of natural and anthropogenic disturbances in aquatic ecosystems. During 2008, the seagrass beds of Zostera noltii located in the Mira estuary (SW Portugal) disappeared completely. However, during 2009, slight symptoms of natural recovery were observed, a process which has since evolved intermittently. This study aims to investigate changes in patterns of nematode density, diversity, and trophic composition between two distinct habitat conditions: "before" the collapse of seagrass beds, and during the early recovery "after" the seagrass habitat loss, through the analysis of: i) temporal and spatial distribution patterns of nematode communities, and ii) the most important environmental variables influencing the nematode assemblages. The following hypotheses were tested: i) there would be differences in nematode assemblage density, biodiversity and trophic composition during both ecological conditions, "before" and "after"; and ii) there would be differences in nematode assemblage density, biodiversity and trophic composition at different sampling occasions during both ecological conditions. Nematode density and diversity were significantly different between the two ecological situations. A higher density was recorded before, but a higher diversity was evident after the collapse of Z. noltii. In spite of the disturbance caused by the seagrass habitat loss in the Mira estuary, the nematode trophic composition did not significantly differ between the before and after seagrass collapse situations. Despite the significant differences found among sampling occasions, a consistent temporal pattern was not evident. The response of nematode communities following this extreme event exhibited considerable resistance and resilience to the new environmental conditions.

Ranking current and prospective NO2 pollution mitigation strategies: An environmental and economic modelling investigation in Oxford Street, London.

PubMed

Jeanjean, A P R; Gallagher, J; Monks, P S; Leigh, R J

2017-06-01

Air pollution continues to be a problem in the urban environment. A range of different pollutant mitigation strategies that promote dispersion and deposition exist, but there is little evidence with respect to their comparative performance from both an environmental and economic perspective. This paper focuses on examining different NO 2 mitigation strategies such as trees, buildings facades coated with photocatalytic paint and solid barriers in Oxford Street in London. The case study findings will support ranking the environmental and economic impacts of these different strategies to improve personal exposure conditions on the footpath and on the road in a real urban street canyon. CFD simulations of airflow and NO 2 dispersion in Oxford Street in London were undertaken using the OpenFOAM software platform with the k-ε model, taking into account local prevailing wind conditions. Trees are shown to be the most cost-effective strategy, with a small reduction in NO 2 concentrations of up to 0.7% on the road. However, solid barriers with and without the application of photocatalytic paint and an innovative material (20 times more expensive than trees) can improve air quality on the footpaths more substantially, up to 7.4%, yet this has a significant detrimental impact on NO 2 concentrations (≤23.8%) on the road. Photocatalytic paint on building surfaces presented a minimal environmental reductions (1.2%) and economic (>100 times more expensive than trees) mitigation strategy. The findings recognised the differences between footpath and road concentrations occurred and that a focused examination of three pollution hotspots can provide more cost effective pollution mitigation. This study considers how a number of pollutant mitigation measures can be applied in a single street canyon and demonstrates the strengths and weaknesses of these strategies from economic and environmental perspectives. Further research is required to extrapolate the findings presented here to different street geometries. Copyright © 2017. Published by Elsevier Ltd.

Behaviour of mobile macrofauna is a key factor in beach ecology as response to rapid environmental changes

NASA Astrophysics Data System (ADS)

Scapini, Felicita

2014-10-01

Sandy beach animals show behavioural adaptations that are expressed as contingencies during the life history of individuals to face periodic and episodic environmental changes. Such adaptations include activity rhythms, orientation, zonation, burrowing, escape responses and feeding strategies, the first two being common adaptations to all mobile animals. The complex conditions of a particular beach environment may be integrated in a learning process enhancing the adaptation and survival of individuals and eventually of populations. Evidence exists of genetic determination of some behavioural features that are adaptive in the long term (throughout generations) by increasing individual survival and reproductive potential. The environmental features integrated with the life history of beach animals shape the individual behaviour through ontogenetic processes, as well as population behaviour through evolutionary processes. Thus, behavioural differences among individuals may reflect environmental variation at the local and small/medium temporal scales of beach processes, whereas within-population behavioural coherence and differences among populations may reflect variation at the geographic scale. The different foci stressed by different authors and the variety of evidence dependent upon local geographical and ecological conditions have often resulted in compartmentalised explanations, making generalizations and the repeatability of behavioural studies of beach ecology challenging. There was a need to developing a more synthetic paradigm for beach animal behaviour. This paper gives a brief overview of the theoretical background and keystone studies, which have contributed to our understanding of animal behaviour in sandy beach ecology, and proposes testable hypotheses to be integrated in the beach ecology paradigm.

Dealing with fixed emissions ceilings in an uncertain future: Offsetting under environmental integrity.

PubMed

Wagner, Fabian; Schöpp, Wolfgang; Amann, Markus

2013-11-15

National emission ceilings are a policy instrument to reduce adverse environmental impacts of transboundary air pollution. Such ceilings for SO2, NOx, NH3 and VOC are established, for example, in the Gothenburg Protocol of the Convention on Long-range Transboundary Air Pollution (UNECE, 1999) and the National Emission Ceilings (NEC) Directive of the European Union (EC, 2001a, b). They prescribe for each pollutant a fixed upper limit on emissions for a specific year. Flexibility in achieving them could lower implementation costs if reality develops differently from what was foreseen during negotiations. In this paper, we explore the conditions under which emission reductions for one pollutant (e.g., SO2) could be offset by additional cuts of another pollutant (e.g., NOx) within the same country, without compromising the environmental improvements that are envisaged from the original set of emission ceilings. We employ the impact module of the GAINS (Greenhouse gas - Air pollution Interactions and Synergies) model to examine possible exchange rates across pollutants for the 2012 negotiations on the revision of the Gothenburg Protocol in Europe. Our analysis shows that exchange rates that satisfy the environmental integrity condition can be established, but that their values vary substantially across countries. Extending the environmental integrity condition to downwind countries will require significantly higher exchange rates. We discuss aspects that decision makers would need to consider before adopting an offsetting schema for future international environmental agreements. Copyright © 2013 Elsevier Ltd. All rights reserved.

Incentive Policy Options for Product Remanufacturing: Subsidizing Donations or Resales?

PubMed

Zhu, Xiaodong; Wang, Zhe; Wang, Yue; Li, Bangyi

2017-12-01

Remanufactured products offer better environmental benefits, and governments encourage manufacturers to remanufacture through various subsidy policies. This practice has shown that, in addition to product sales, remanufactured product can also achieve its value through social donation. Based on the remanufactured product value realization approaches, governments provide two kinds of incentive policies, which are remanufactured product sales subsidies and remanufactured product donation subsidies. This paper constructs a two-stage Stackelberg game model including a government and a manufacturer under two different policies, which can be solved by backward induction. By comparing the optimal decision of the two policies, our results show that, compared with the remanufacturing sales subsidy, donation subsidy weakens the cannibalization of remanufactured products for new products and increases the quantity of new products. It reduces the sales quantity of remanufactured products, but increases their total quantity. Under certain conditions of low subsidy, the manufacturer adopting sales subsidy provides better economic and environmental benefits. Under certain conditions of high subsidy, the manufacturer adopting donation subsidy offers better economic and environmental benefits. When untreated product environmental impact is large enough, donation subsidy policy has a better social welfare. Otherwise, the choice of social welfare of these two different policies depends on the social impact of remanufactured product donated.

Incentive Policy Options for Product Remanufacturing: Subsidizing Donations or Resales?

PubMed Central

Zhu, Xiaodong; Wang, Yue; Li, Bangyi

2017-01-01

Remanufactured products offer better environmental benefits, and governments encourage manufacturers to remanufacture through various subsidy policies. This practice has shown that, in addition to product sales, remanufactured product can also achieve its value through social donation. Based on the remanufactured product value realization approaches, governments provide two kinds of incentive policies, which are remanufactured product sales subsidies and remanufactured product donation subsidies. This paper constructs a two-stage Stackelberg game model including a government and a manufacturer under two different policies, which can be solved by backward induction. By comparing the optimal decision of the two policies, our results show that, compared with the remanufacturing sales subsidy, donation subsidy weakens the cannibalization of remanufactured products for new products and increases the quantity of new products. It reduces the sales quantity of remanufactured products, but increases their total quantity. Under certain conditions of low subsidy, the manufacturer adopting sales subsidy provides better economic and environmental benefits. Under certain conditions of high subsidy, the manufacturer adopting donation subsidy offers better economic and environmental benefits. When untreated product environmental impact is large enough, donation subsidy policy has a better social welfare. Otherwise, the choice of social welfare of these two different policies depends on the social impact of remanufactured product donated. PMID:29194411

[Study of the association between socio-environmental factors and the prevalence of intestinal parasitosis in the suburbs of the city of Manaus in the state of Amazonas, Brazil].

PubMed

Visser, Silvia; Giatti, Leandro Luiz; Carvalho, Ricardo Augusto Chaves de; Guerreiro, Jose Camilo Hurtado

2011-08-01

This study assesses the association between socio-environmental factors and urban sanitation conditions with the prevalence of intestinal parasitosis in a community on the periphery of the city of Manaus. The study comprised a socio-environmental survey and a parasitological inquiry. A heterogeneous community was revealed with some socio-economic and environmental differences between the micro-areas evaluated, even though the urban sanitation conditions were found to be predominantly precarious. The prevalence of intestinal parasitosis was 44.2%. There was no significant difference between the micro-areas that could explain the occurrence of intestinal parasitosis. An association was found between intestinal parasitosis and residential building types, age bracket and the quality of the water used for personal hygiene and consumption in the home. Open air sewage was a risk factor associated with intestinal parasitosis (OR=6.72; p=0.034) and also with intestinal protozoa (OR=21.87; p=0.004). In terms of the presence of protozoa, two risk factors were verified: the dumping of sewage directly into the river system (OR=12.98; p=0.011) and the use of rudimentary cesspits (OR=9.54; p=0.019).

Environmental conditions can modulate the links among oxidative stress, age, and longevity.

PubMed

Marasco, Valeria; Stier, Antoine; Boner, Winnie; Griffiths, Kate; Heidinger, Britt; Monaghan, Pat

2017-06-01

Understanding the links between environmental conditions and longevity remains a major focus in biological research. We examined within-individual changes between early- and mid-adulthood in the circulating levels of four oxidative stress markers linked to ageing, using zebra finches (Taeniopygia guttata): a DNA damage product (8-hydroxy-2'-deoxyguanosine; 8-OHdG), protein carbonyls (PC), non-enzymatic antioxidant capacity (OXY), and superoxide dismutase activity (SOD). We further examined whether such within-individual changes differed among birds living under control (ad lib food) or more challenging environmental conditions (unpredictable food availability), having previously found that the latter increased corticosterone levels when food was absent but improved survival over a three year period. Our key findings were: (i) 8-OHdG and PC increased with age in both environments, with a higher increase in 8-OHdG in the challenging environment; (ii) SOD increased with age in the controls but not in the challenged birds, while the opposite was true for OXY; (iii) control birds with high levels of 8-OHdG died at a younger age, but this was not the case in challenged birds. Our data clearly show that while exposure to the potentially damaging effects of oxidative stress increases with age, environmental conditions can modulate the pace of this age-related change. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of environmental conditions on the relationship between solar-induced fluorescence and gross primary productivity at an OzFlux grassland site

NASA Astrophysics Data System (ADS)

Verma, Manish; Schimel, David; Evans, Bradley; Frankenberg, Christian; Beringer, Jason; Drewry, Darren T.; Magney, Troy; Marang, Ian; Hutley, Lindsay; Moore, Caitlin; Eldering, Annmarie

2017-03-01

Recent studies have utilized coarse spatial and temporal resolution remotely sensed solar-induced fluorescence (SIF) for modeling terrestrial gross primary productivity (GPP) at regional scales. Although these studies have demonstrated the potential of SIF, there have been concerns about the ecophysiological basis of the relationship between SIF and GPP in different environmental conditions. Launched in 2014, the Orbiting Carbon Observatory-2 (OCO-2) has enabled fine-scale (1.3 by 2.5 km) retrievals of SIF that are comparable with measurements recorded at eddy covariance towers. In this study, we examine the effect of environmental conditions on the relationship of OCO-2 SIF with tower GPP over the course of a growing season at a well-characterized natural grassland site. Combining OCO-2 SIF and eddy covariance tower data with a canopy radiative transfer and an ecosystem model, we also assess the potential of OCO-2 SIF to constrain the estimates of Vcmax, one of the most important parameters in ecosystem models. Based on the results, we suggest that although environmental conditions play a role in determining the nature of relationship between SIF and GPP, overall, the linear relationship is more robust at ecosystem scale than the theory based on leaf-level processes might suggest. Our study also shows that the ability of SIF to constrain Vcmax is weak at the selected site.

The Effects of Light and Temperature on Biotin Synthesis in Pea Sprouts.

PubMed

Kamiyama, Shin; Ohnuki, Risa; Moriki, Aoi; Abe, Megumi; Ishiguro, Mariko; Sone, Hideyuki

2016-01-01

Biotin is an essential micronutrient, and is a cofactor for several carboxylases that are involved in the metabolism of glucose, fatty acids, and amino acids. Because plant cells can synthesize their own biotin, a wide variety of plant-based foods contains significant amounts of biotin; however, the influence of environmental conditions on the biotin content in plants remains largely unclear. In the present study, we investigated the effects of different cultivation conditions on the biotin content and biotin synthesis in pea sprouts (Pisum sativum). In the experiment, the pea sprouts were removed from their cotyledons and cultivated by hydroponics under five different lighting and temperature conditions (control [25ºC, 12-h light/12-h dark cycle], low light [25ºC, 4-h light/20-h dark cycle], dark [25ºC, 24 h dark], low temperature [12ºC, 12-h light/12-h dark cycle], and cold [6ºC, 12-h light/12-h dark cycle]) for 10 d. Compared to the biotin content of pea sprouts under the control conditions, the biotin contents of pea sprouts under the low-light, dark, and cold conditions had significantly decreased. The dark group showed the lowest biotin content among the groups. Expression of the biotin synthase gene (bio2) was also significantly decreased under the dark and cold conditions compared to the control condition, in a manner similar to that observed for the biotin content. No significant differences in the adenosine triphosphate content were observed among the groups. These results indicate that environmental conditions such as light and temperature modulate the biotin content of pea plant tissues by regulating the expression of biotin synthase.

Assessing the relative importance of environmental effects, carry-over effects and species differences in thermal stress resistance: a comparison of Drosophilids across field and laboratory generations.

PubMed

Schiffer, Michele; Hangartner, Sandra; Hoffmann, Ary A

2013-10-15

There is increasing interest in comparing species of related organisms for their susceptibility to thermal extremes in order to evaluate potential vulnerability to climate change. Comparisons are typically undertaken on individuals collected from the field with or without a period of acclimation. However, this approach does not allow the potential contributions of environmental and carry-over effects across generations to be separated from inherent species differences in susceptibility. To assess the importance of these different sources of variation, we here considered heat and cold resistance in Drosophilid species from tropical and temperate sites in the field and across two laboratory generations. Resistance in field-collected individuals tended to be lower when compared with F1 and F2 laboratory generations, and species differences in field flies were only weakly correlated to differences established under controlled rearing conditions, unlike in F1-F2 comparisons. This reflected large environmental effects on resistance associated with different sites and conditions experienced within sites. For the 8 h cold recovery assay there was no strong evidence of carry-over effects, whereas for the heat knockdown and 2 h cold recovery assays there was some evidence for such effects. However, for heat these were species specific in direction. Variance components for inherent species differences were substantial for resistance to heat and 8 h cold stress, but small for 2 h cold stress, though this may be a reflection of the species being considered in the comparisons. These findings highlight that inherent differences among species are difficult to characterise accurately without controlling for environmental sources of variation and carry-over effects. Moreover, they also emphasise the complex nature of carry-over effects that vary depending on the nature of stress traits and the species being evaluated.

Evaluation of an automated bridge anti-icing system [poster].

DOT National Transportation Integrated Search

2013-01-01

Bridges and adjacent highways experience different environmental conditions. Depending on bridge : height, wind direction and other parameters, pavements are subject to moisture and quick changes in : temperature. Without the benefit of residual grou...

GENOMIC APPROACHES FOR CROSS-SPECIES EXTRAPOLATION IN TOXICOLOGY

EPA Science Inventory

The latest tools for investigating stress in organisms, genomic technologies provide great insight into how different organisms respond to environmental conditions. However, their usefulness needs testing, verification, and codification. Genomic Approaches for Cross-Species Extra...

Methods of establishing plantations of hybrid-poplar cuttings

Treesearch

Frank E. Cunningham

1954-01-01

Fast-growing hybrid poplars are now being tested in plantations scattered from Maine to West Virginia to find out how the different hybrids respond to a wide range of environmental conditions throughout the Northeast.

A stochastic bioenergetics model based approach to translating large river flow and temperature in to fish population responses: The pallid sturgeon example

USGS Publications Warehouse

Wildhaber, Mark L.; Dey, Rima; Wikle, Christopher K.; Moran, Edward H.; Anderson, Christopher J.; Franz, Kristie J.

2015-01-01

In managing fish populations, especially at-risk species, realistic mathematical models are needed to help predict population response to potential management actions in the context of environmental conditions and changing climate while effectively incorporating the stochastic nature of real world conditions. We provide a key component of such a model for the endangered pallid sturgeon (Scaphirhynchus albus) in the form of an individual-based bioenergetics model influenced not only by temperature but also by flow. This component is based on modification of a known individual-based bioenergetics model through incorporation of: the observed ontogenetic shift in pallid sturgeon diet from marcroinvertebrates to fish; the energetic costs of swimming under flowing-water conditions; and stochasticity. We provide an assessment of how differences in environmental conditions could potentially alter pallid sturgeon growth estimates, using observed temperature and velocity from channelized portions of the Lower Missouri River mainstem. We do this using separate relationships between the proportion of maximum consumption and fork length and swimming cost standard error estimates for fish captured above and below the Kansas River in the Lower Missouri River. Critical to our matching observed growth in the field with predicted growth based on observed environmental conditions was a two-step shift in diet from macroinvertebrates to fish.

Impact of relative humidity, inoculum carrier and size, and native microbiota on Salmonella ser. Typhimurium survival in baby lettuce.

PubMed

López-Gálvez, Francisco; Gil, Maria Isabel; Allende, Ana

2018-04-01

The effects of relative humidity (RH), fluctuating climate conditions, inoculum size and carrier on the survival of Salmonella enterica serovar Typhimurium on baby lettuce in environmental test chambers were studied. Buffered peptone water (BPW), distilled water (DW), and irrigation water (IW) were compared as inoculum carriers. Additionally, survival of Salmonella in suspensions prepared using filtered and unfiltered IW was assessed. Salmonella Typhimurium survived better on baby lettuce plants at high RH independently of the inoculum size. When lettuce plants were grown under fluctuating environmental conditions, Salmonella survival was similar under both RH conditions. Regarding the inoculum carrier, the inoculated microorganism survived better on lettuce plants when BPW was used as carrier both at high and low RH. Survival rate of Salmonella in IW was affected by the presence of native microbiota. Native microbiota present in IW did not affect survival of Salmonella or the levels of mesophilic bacteria on the baby lettuce leaves. The information obtained in the present study contributes to the knowledge on the effect of environmental conditions on pathogenic bacteria survival on growing edible plants. These results are useful when selecting the methodology to carry out experimental studies on the survival of microbial pathogens under different pre-harvest conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Method and system for environmentally adaptive fault tolerant computing

NASA Technical Reports Server (NTRS)

Copenhaver, Jason L. (Inventor); Jeremy, Ramos (Inventor); Wolfe, Jeffrey M. (Inventor); Brenner, Dean (Inventor)

2010-01-01

A method and system for adapting fault tolerant computing. The method includes the steps of measuring an environmental condition representative of an environment. An on-board processing system's sensitivity to the measured environmental condition is measured. It is determined whether to reconfigure a fault tolerance of the on-board processing system based in part on the measured environmental condition. The fault tolerance of the on-board processing system may be reconfigured based in part on the measured environmental condition.

Occurrence and behavior of butyltins in intertidal and shallow subtidal surface sediments of an estuarine beach under different sampling conditions

NASA Astrophysics Data System (ADS)

Santos, Dayana Moscardi dos; Sant'Anna, Bruno Sampaio; Sandron, Daniela Corsino; Cardoso de Souza, Sara; Cristale, Joyce; Marchi, Mary Rosa Rodrigues de; Turra, Alexander

2010-07-01

Contamination by butyltin compounds (BTs) has been reported in estuarine environments worldwide, with serious impacts on the biota of these areas. Considering that BTs can be degraded by varying environmental conditions such as incident light and salinity, the short-term variations in such factors may lead to inaccurate estimates of BTs concentrations in nature. Therefore, the present study aimed to evaluate the possibility that measurements of BTs in estuarine sediments are influenced by different sampling conditions, including period of the day (day or night), tidal zone (intertidal or subtidal), and tides (high or low). The study area is located on the Brazilian southeastern coast, São Vicente Estuary, at Pescadores Beach, where BT contamination was previously detected. Three replicate samples of surface sediment were collected randomly in each combination of period of the day, tidal zone, and tide condition, from three subareas along the beach, totaling 72 samples. BTs were analyzed by GC-PFPD using a tin filter and a VF-5 column, by means of a validated method. The concentrations of tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) ranged from undetectable to 161 ng Sn g -1 (d.w.). In most samples (71%), only MBT was quantifiable, whereas TBTs were measured in only 14, suggesting either an old contamination or rapid degradation processes. DBT was found in 27 samples, but could be quantified in only one. MBT concentrations did not differ significantly with time of day, zones, or tide conditions. DBT and TBT could not be compared under all these environmental conditions, because only a few samples were above the quantification limit. Pooled samples of TBT did not reveal any difference between day and night. These results indicated that, in assessing contamination by butyltin compounds, surface-sediment samples can be collected in any environmental conditions. However, the wide variation of BTs concentrations in the study area, i.e., over a very small geographic scale, illustrates the need for representative hierarchical and composite sampling designs that are compatible with the multiscalar temporal and spatial variability common to most marine systems. The use of such sampling designs will be necessary for future attempts to quantitatively evaluate and monitor the occurrence and impact of these compounds in nature.

Medieval Iceland, Greenland, and the New Human Condition: A case study in integrated environmental humanities

NASA Astrophysics Data System (ADS)

Hartman, Steven; Ogilvie, A. E. J.; Ingimundarson, Jón Haukur; Dugmore, A. J.; Hambrecht, George; McGovern, T. H.

2017-09-01

This paper contributes to recent studies exploring the longue durée of human impacts on island landscapes, the impacts of climate and other environmental changes on human communities, and the interaction of human societies and their environments at different spatial and temporal scales. In particular, the paper addresses Iceland during the medieval period (with a secondary, comparative focus on Norse Greenland) and discusses episodes where environmental and climatic changes have appeared to cross key thresholds for agricultural productivity. The paper draws upon international, interdisciplinary research in the North Atlantic region led by the North Atlantic Biocultural Organization (NABO) and the Nordic Network for Interdisciplinary Environmental Studies (NIES) in the Circumpolar Networks program of the Integrated History and Future of People on Earth (IHOPE). By interlinking analyses of historically grounded literature with archaeological studies and environmental science, valuable new perspectives can emerge on how these past societies may have understood and coped with such impacts. As climate and other environmental changes do not operate in isolation, vulnerabilities created by socioeconomic factors also beg consideration. The paper illustrates the benefits of an integrated environmental-studies approach that draws on data, methodologies and analytical tools of environmental humanities, social sciences, and geosciences to better understand long-term human ecodynamics and changing human-landscape-environment interactions through time. One key goal is to apply previously unused data and concerted expertise to illuminate human responses to past changes; a secondary aim is to consider how lessons derived from these cases may be applicable to environmental threats and socioecological risks in the future, especially as understood in light of the New Human Condition, the concept transposed from Hannah Arendt's influential framing of the human condition that is foregrounded in the present special issue. This conception admits human agency's role in altering the conditions for life on earth, in large measure negatively, while acknowledging the potential of this self-same agency, if effectively harnessed and properly directed, to sustain essential planetary conditions through a salutary transformation of human perception, understanding and remedial action. The paper concludes that more long-term historical analyses of cultures and environments need to be undertaken at various scales. Past cases do not offer perfect analogues for the future, but they can contribute to a better understanding of how resilience and vulnerability occur, as well as how they may be compromised or mitigated.

Mapping of recent brachiopod microstructure: a tool for environmental and climate studies

NASA Astrophysics Data System (ADS)

Ye, Facheng; Angiolini, Lucia; Crippa, Gaia; Garbelli, Claudio; Brand, Uwe; Cusack, Maggie; Harper, Elizabeth

2017-04-01

The shells of brachiopods are considered excellent archives of proxies for palaeoenvironment reconstructions. In fact, their biominerals when preserved in the fossil record have considerable potential for extending the climate and environmental record in the geological past. However, their use as fossil archives requires an understanding of how recent shells maintain or change their morphostructure and geochemistry in response to climate, environmental pressures or even ontogenetic/species-specific variation. Here, we focus on the morphology and size of the basic structural units (the fibres within the secondary layer) of several extant brachiopod taxa, to understand their growth program and ontogenetic variation, and if and how they are affected by different environmental conditions. Twenty-nine specimens of six recent brachiopod species [Notosaria nigricans (Sowerby, 1846), Liothyrella neozelanica (Thomson, 1918), Liothyrella uva (Broderip, 1833), Magasella sanguinea (Leach, 1814), Gryphus vitreus (Born, 1778), Calloria inconspicua (Sowerby, 1846)] were chosen for shell microstructural analysis using scanning electron microscopy. The morphology and size of each fibre in the shells of these specimens (600 fibres in ventral valves and 587 fibres in dorsal valves) were described using six parameters [Max and Min ferret (caliper diameter, i.e. longest/shortest distance between any two parallel tangents on the fibre), Area, Perimeter, Convex area and Convex perimeter]. Based on the statistical analysis of these data, we conclude that: 1) There is no significant difference in the shape and size of the fibres between ventral and dorsal valves of specimen's; 2) there is an ontogenetic trend in the shape and size of the fibres, as they invariably become wider and flatter with increasing age, that is from the external posterior part to the internal anterior part of each valve. This has important implications in comparative studies of fossil shells; 3) when comparing two species of the same genus living in different environmental conditions (e.g., Liothyrella uva and Liothyrella neozelanica), the fibres of Liothyrella uva are narrower and rounder than those of Liothyrella neozelanica, a difference that can be related to environmental differences of their habitats.

Noise in gene expression is coupled to growth rate.

PubMed

Keren, Leeat; van Dijk, David; Weingarten-Gabbay, Shira; Davidi, Dan; Jona, Ghil; Weinberger, Adina; Milo, Ron; Segal, Eran

2015-12-01

Genetically identical cells exposed to the same environment display variability in gene expression (noise), with important consequences for the fidelity of cellular regulation and biological function. Although population average gene expression is tightly coupled to growth rate, the effects of changes in environmental conditions on expression variability are not known. Here, we measure the single-cell expression distributions of approximately 900 Saccharomyces cerevisiae promoters across four environmental conditions using flow cytometry, and find that gene expression noise is tightly coupled to the environment and is generally higher at lower growth rates. Nutrient-poor conditions, which support lower growth rates, display elevated levels of noise for most promoters, regardless of their specific expression values. We present a simple model of noise in expression that results from having an asynchronous population, with cells at different cell-cycle stages, and with different partitioning of the cells between the stages at different growth rates. This model predicts non-monotonic global changes in noise at different growth rates as well as overall higher variability in expression for cell-cycle-regulated genes in all conditions. The consistency between this model and our data, as well as with noise measurements of cells growing in a chemostat at well-defined growth rates, suggests that cell-cycle heterogeneity is a major contributor to gene expression noise. Finally, we identify gene and promoter features that play a role in gene expression noise across conditions. Our results show the existence of growth-related global changes in gene expression noise and suggest their potential phenotypic implications. © 2015 Keren et al.; Published by Cold Spring Harbor Laboratory Press.

Noise in gene expression is coupled to growth rate

PubMed Central

Keren, Leeat; van Dijk, David; Weingarten-Gabbay, Shira; Davidi, Dan; Jona, Ghil; Weinberger, Adina; Milo, Ron; Segal, Eran

2015-01-01

Genetically identical cells exposed to the same environment display variability in gene expression (noise), with important consequences for the fidelity of cellular regulation and biological function. Although population average gene expression is tightly coupled to growth rate, the effects of changes in environmental conditions on expression variability are not known. Here, we measure the single-cell expression distributions of approximately 900 Saccharomyces cerevisiae promoters across four environmental conditions using flow cytometry, and find that gene expression noise is tightly coupled to the environment and is generally higher at lower growth rates. Nutrient-poor conditions, which support lower growth rates, display elevated levels of noise for most promoters, regardless of their specific expression values. We present a simple model of noise in expression that results from having an asynchronous population, with cells at different cell-cycle stages, and with different partitioning of the cells between the stages at different growth rates. This model predicts non-monotonic global changes in noise at different growth rates as well as overall higher variability in expression for cell-cycle–regulated genes in all conditions. The consistency between this model and our data, as well as with noise measurements of cells growing in a chemostat at well-defined growth rates, suggests that cell-cycle heterogeneity is a major contributor to gene expression noise. Finally, we identify gene and promoter features that play a role in gene expression noise across conditions. Our results show the existence of growth-related global changes in gene expression noise and suggest their potential phenotypic implications. PMID:26355006

Reduction in predicted survival times in cold water due to wind and waves.

PubMed

Power, Jonathan; Simões Ré, António; Barwood, Martin; Tikuisis, Peter; Tipton, Michael

2015-07-01

Recent marine accidents have called into question the level of protection provided by immersion suits in real (harsh) life situations. Two immersion suit studies, one dry and the other with 500 mL of water underneath the suit, were conducted in cold water with 10-12 males in each to test body heat loss under three environmental conditions: calm, as mandated for immersion suit certification, and two combinations of wind plus waves to simulate conditions typically found offshore. In both studies mean skin heat loss was higher in wind and waves vs. calm; deep body temperature and oxygen consumption were not different. Mean survival time predictions exceeded 36 h for all conditions in the first study but were markedly less in the second in both calm and wind and waves. Immersion suit protection and consequential predicted survival times under realistic environmental conditions and with leakage are reduced relative to calm conditions. Copyright © 2015. Published by Elsevier Ltd.

Experimental and Theoretical Investigations on the Nanoscale Kinetic Friction in Ambient Environmental Conditions.

PubMed

Gueye, Birahima; Zhang, Yan; Wang, Yujuan; Chen, Yunfei

2015-07-08

The liquid lubrication, thermolubricity and dynamic lubricity due to mechanical oscillations are investigated with an atomic force microscope in ambient environmental conditions with different relative humidity (RH) levels. Experimental results demonstrate that high humidity at low-temperature regime enhances the liquid lubricity while at high-temperature regime it hinders the effect of the thermolubricity due to the formation of liquid bridges. Friction response to the dynamic lubricity in both high- and low-temperature regimes keeps the same trends, namely the friction force decreases with increasing the amplitude of the applied vibration on the tip regardless of the RH levels. An interesting finding is that for the dynamic lubricity at high temperature, high-humidity condition leads to the friction forces higher than that at low-humidity condition while at low temperature the opposite trend is observed. An extended two-dimensional dynamic model accounting for the RH is proposed to interpret the frictional mechanism in ambient conditions.

Quantitative comparison of the in situ microbial communities in different biomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, D.C.; Ringelberg, D.B.; Palmer, R.J.

1995-12-31

A system to define microbial communities in different biomes requires the application of non-traditional methodology. Classical microbiological methods have severe limitations for the analysis of environmental samples. Pure-culture isolation, biochemical testing, and/or enumeration by direct microscopic counting are not well suited for the estimation of total biomass or the assessment of community composition within environmental samples. Such methods provide little insight into the in situ phenotypic activity of the extant microbiota since these techniques are dependent on microbial growth and thus select against many environmental microorganisms which are non- culturable under a wide range of conditions. It has been repeatedlymore » documented in the literature that viable counts or direct counts of bacteria attached to sediment grains are difficult to quantitative and may grossly underestimate the extent of the existing community. The traditional tests provide little indication of the in situ nutritional status or for evidence of toxicity within the microbial community. A more recent development (MIDI Microbial Identification System), measure free and ester-linked fatty acids from isolated microorganisms. Bacterial isolates are identified by comparing their fatty acid profiles to the MIKI database which contains over 8000 entries. The application of the MIKI system to the analysis of environmental samples however, has significant drawbacks. The MIDI system was developed to identify clinical microorganisms and requires their isolation and culture on trypticase soy agar at 27{degrees}C. Since many isolates are unable to grow at these restrictive growth conditions, the system does not lend itself to identification of some environmental organisms. A more applicable methodology for environmental microbial analysis is based on the liquid extrication and separation of microbial lipids from environmental samples, followed by quantitative analysis using gas chromatography/« less

33 CFR 148.710 - What environmental conditions must be satisfied?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false What environmental conditions... Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license to construct a deepwater port under the Act, with or without conditions, if certain specified conditions are...

33 CFR 148.710 - What environmental conditions must be satisfied?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false What environmental conditions... Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license to construct a deepwater port under the Act, with or without conditions, if certain specified conditions are...

33 CFR 148.710 - What environmental conditions must be satisfied?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false What environmental conditions... Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license to construct a deepwater port under the Act, with or without conditions, if certain specified conditions are...

33 CFR 148.710 - What environmental conditions must be satisfied?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false What environmental conditions... Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license to construct a deepwater port under the Act, with or without conditions, if certain specified conditions are...

Environmental conditions affecting exopolysaccharide production by Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.

PubMed

Kiliç, Nur Koçberber; Dönmez, Gönül

2008-06-15

Three different chromium-resistant microorganisms (Pseudomonas aeruginosa, Micrococcus sp., and Ochrobactrum sp.) were tested with regard to their EPS production at different pH levels, temperatures, Cr(VI) concentrations, and incubation periods. The optimum pH level was 7 for P. aeruginosa and Micrococcus sp., while it was 8 for Ochrobactrum sp. according to the highest EPS amount at 100 mg/L Cr(VI) concentration. The highest production of EPSs by the three bacteria was obtained under different environmental conditions. P. aeruginosa produced the highest EPS (863.3 mg/L) after incubation for 96 h on media with 50 mg/L Cr(VI) at 20 degrees C, Micrococcus sp. gave the highest yield (444.6 mg/L) after incubation for 72 h on media with 100 mg/L Cr(VI) at the same temperature, and Ochrobactrum sp. had the highest production (430.5 mg/L) on media with 150 mg/L Cr(VI) at 30 degrees C at the end of 48 h of incubation.

[Ergonomics in planning and reconstruction].

PubMed

Baglioni, A; Capolongo, S

2002-01-01

The state of well being of people is not represented only by any illness, but also by the satisfaction of all environmental components around him. For this reason, the hospitals demand new and more project attentions and in particular they demand specific attentions for all the environmental qualities (light, colours, indoor air qualities, and temperature), the equipment, the furniture and the privacy. This new attention to the requirements of people, during the phase of planning, needs the ergonomic studies. This kind of discipline, in fact, has got the objective of good relationships between men and context where they live. The study of ergonomic qualities needs different competence of multiple areas of acquaintance, that collaborate to analyse the requirements of sanitary structure, and in particular they analyse needs of different categories of people that work or stay in this place (the patients, visitors and sanitary staff). Moreover ergonomic studies concurs to analyse the various factors of complexity, of the buildings, that are very important for the project of hospital. From the scientific literature, we say that some physical environmental characteristics (light, colour, noise,) can influence the psychological conditions of people, and in particular they can generate three different categories of reactions: behavioural, neuropsychological, neuroendocrinal. For this reason the study of all the environmental factors, simple and composed, is a primary necessity in the hospital planning. In this way we can guarantee to the patient, a better sanitary service and a better comfort, and we can guarantee to all sanitary staff adequate conditions of security and functionality.

[The heart in extreme sports: hyperbaric activity and microgravity].

PubMed

Berrettini, Umberto; Landolfi, Angelo; Patteri, Giovanna

2008-10-01

The study of the cardiovascular and respiratory modifications in extreme environments could be useful for the understanding of the adaptive mechanisms of the body in particular conditions. The knowledge of how different environmental conditions in terms of extreme pressure, temperature and gravity modify the neurovegetative and cardiovascular system could be useful in daily practice for hypobaric and hyperbaric sports.

The combined effect of pressure and oxygen concentration on piloted ignition of a solid combustible

Treesearch

Sara McAllister; Carlos Fernandez-Pello; David Urban; Gary Ruff

2010-01-01

There are a number of situations when fires may occur at low pressures and oxygen concentrations that are different than standard atmospheric conditions, such as in buildings at high elevation, airplanes, and spacecraft. The flammability of materials may be affected by these environmental conditions. Since ignition delay is a measure of material flammability and...

Therapeutic Effects of Anthocyanins and Environmental Enrichment in R6/1 Huntington's Disease Mice.

PubMed

Kreilaus, Fabian; Spiro, Adena S; Hannan, Anthony J; Garner, Brett; Jenner, Andrew M

2016-10-01

Huntington's disease (HD) is a progressive neurodegenerative disease with no effective treatment or cure. Environmental enrichment has been used to slow processes leading to ageing and neurodegenerative diseases including HD. Phenolic phytochemicals including anthocyanins have also been shown to improve brain function in ageing and neurodegenerative diseases. This study examined the effects of anthocyanin dietary supplementation and environmental enrichment on behavioural phenotypes and brain cholesterol metabolic alterations in the R6/1 mouse model of HD. R6/1 HD mice and their wild-type littermate controls were randomised into the different experimental conditions, involving either environmentally enriched versus standard housing conditions, or anthocyanin versus control diet. Motor dysfunction was assessed from 6 to 26 weeks using the RotaRod and the hind-paw clasping tests. Gas chromatography - tandem mass spectrometry was used to quantify a broad range of sterols in the striatum and cortex of R6/1 HD mice. Anthocyanin dietary supplementation delayed the onset of motor dysfunction in female HD mice. Environmental enrichment improved motor function and the hind paw clasping phenotype in male HD mice only. These mice also had lower levels of cholesterol oxidation products in the cortex compared to standard-housed mice. Both anthocyanin supplementation and environmental enrichment are able to improve the motor dysfunction phenotype of R6/1 mice, however the effectiveness of these interventions was different between the two sexes. The interventions examined did not alter brain cholesterol metabolic deficits that have been reported previously in this mouse model of HD.

From Microhabitat of Floral Nectar Up to Biogeographic Scale: Novel Insights on Neutral and Niche Bacterial Assemblies.

PubMed

Aizenberg-Gershtein, Yana; Izhaki, Ido; Halpern, Malka

2017-07-01

Microbial model systems are very useful in addressing macro-ecological questions. Two major theories exist to date, to explain the community structure of organisms: (1) the dispersal (neutral) assembly theory which predicts that community similarity decreases with increasing geographic distance, independent of any environmental variables, and (2) the niche assembly theory which predicts that the communities' compositions are more homogeneous among sites characterized by similar environmental conditions. Our study system offered a unique opportunity to investigate the relative role of environmental conditions and spatial factors in shaping community composition. We explored the bacterial community composition (BCC) of Nicotiana glauca floral nectar using the Illumina MiSeq technique at three spatial scales (plants, site, and region) and two taxonomic levels. Floral nectar samples were collected from 69 N. glauca plants at 11 different sites along a 200-km transect in Israel, along three biogeographic regions. A distance decay of BCC was found among all plants throughout Israel, but such pattern was not found among either sites or biogeographical regions. The BCC was also governed by environmental conditions in all examined scales (from the plant up to the biogeographical region). We also found that taxonomic resolution (89 and 97% sequence identity for clustering operational taxonomic units) affected the results of these BCC analyses. Hence, our study revealed that the BCC in N. glauca floral nectar is shaped by both the environmental conditions and the distance between plants, depending on the sampling scale under examination as well as by taxonomic resolution.

Evidence for isolated evolution of deep-sea ciliate communities through geological separation and environmental selection.

PubMed

Stock, Alexandra; Edgcomb, Virginia; Orsi, William; Filker, Sabine; Breiner, Hans-Werner; Yakimov, Michail M; Stoeck, Thorsten

2013-07-08

Deep hypersaline anoxic basins (DHABs) are isolated habitats at the bottom of the eastern Mediterranean Sea, which originate from the ancient dissolution of Messinian evaporites. The different basins have recruited their original biota from the same source, but their geological evolution eventually constituted sharp environmental barriers, restricting genetic exchange between the individual basins. Therefore, DHABs are unique model systems to assess the effect of geological events and environmental conditions on the evolution and diversification of protistan plankton. Here, we examine evidence for isolated evolution of unicellular eukaryote protistan plankton communities driven by geological separation and environmental selection. We specifically focused on ciliated protists as a major component of protistan DHAB plankton by pyrosequencing the hypervariable V4 fragment of the small subunit ribosomal RNA. Geospatial distributions and responses of marine ciliates to differential hydrochemistries suggest strong physical and chemical barriers to dispersal that influence the evolution of this plankton group. Ciliate communities in the brines of four investigated DHABs are distinctively different from ciliate communities in the interfaces (haloclines) immediately above the brines. While the interface ciliate communities from different sites are relatively similar to each other, the brine ciliate communities are significantly different between sites. We found no distance-decay relationship, and canonical correspondence analyses identified oxygen and sodium as most important hydrochemical parameters explaining the partitioning of diversity between interface and brine ciliate communities. However, none of the analyzed hydrochemical parameters explained the significant differences between brine ciliate communities in different basins. Our data indicate a frequent genetic exchange in the deep-sea water above the brines. The "isolated island character" of the different brines, that resulted from geological events and contemporary environmental conditions, create selective pressures driving evolutionary processes, and with time, lead to speciation and shape protistan community composition. We conclude that community assembly in DHABs is a mixture of isolated evolution (as evidenced by small changes in V4 primary structure in some taxa) and species sorting (as indicated by the regional absence/presence of individual taxon groups on high levels in taxonomic hierarchy).

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.

Influence of pasteurization, brining conditions and production environment on the microbiota of artisan Gouda-type cheeses.

PubMed

Van Hoorde, Koenraad; Heyndrickx, Marc; Vandamme, Peter; Huys, Geert

2010-05-01

To monitor the effect of the indigenous milk microbiota and of technological and environmental parameters on the microbiota established in ripened cheese, the diversity and dynamics of the predominant microbial communities in artisan Gouda-type cheeses produced under different conditions was studied. A total of 22 cheese types differing in milk source, milk treatment, production environment and brining conditions were analyzed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE) using total DNA extracts as well as DNA extracted from culturable fractions. Through band position analysis and band sequencing, the majority of DGGE bands could be attributed to lactic acid bacteria (LAB), although a few bands also belonged to staphylococci and gamma-Proteobacteria. Aided by principal component analysis (PCA) and multivariate analysis of variance (MANOVA), cheeses produced at different locations could clearly be differentiated. The same approach also allowed to distinguish raw and pasteurized milk cheeses, the former showing a more diverse microbiota in terms of a higher species richness and number of DGGE bands. No substantial differences were found between cheeses brined at two different locations. In conclusion, the combined PCR-DGGE approach relying on both total DNA extracts and culturable fractions proved its value for analyzing the effect of technological and environmental parameters on the diversity and dynamics of the microbiota in Gouda-type cheeses. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Natural selection and sex differences in morbidity and mortality in early life.

PubMed

Wells, J C

2000-01-07

Both morbidity and mortality are consistently reported to be higher in males than in females in early life, but no explanation for these findings has been offered. This paper argues that the sex difference in early vulnerability can be attributed to the natural selection of optimal maternal strategies for maximizing lifetime reproductive success, as modelled previously by Trivers and Willard. These authors theorized that males and females offer different returns on parental investment depending on the state of the environment. Natural selection has therefore favoured maternal ability to manipulate offspring sex in response to environmental conditions in early life, as shown in variation in the sex ratio at birth. This argument can be extended to the whole period of parental investment until weaning. Male vulnerability in response to environmental stress in early life is predicted to have been favoured by natural selection. This vulnerability is most evident in the harsh conditions resulting from pre-term birth, but can also be seen in term infants, and manifests as greater morbidity and mortality persisting into early childhood. Malnutrition, interacting with infection after birth, is suggested as the fundamental trigger mechanism. The model suggests that whatever improvements are made in medical care, any environmental stress will always affect males more severely than females in early life. Copyright 2000 Academic Press.

Diversity and Assembling Processes of Bacterial Communities in Cryoconite Holes of a Karakoram Glacier.

PubMed

Ambrosini, Roberto; Musitelli, Federica; Navarra, Federico; Tagliaferri, Ilario; Gandolfi, Isabella; Bestetti, Giuseppina; Mayer, Christoph; Minora, Umberto; Azzoni, Roberto Sergio; Diolaiuti, Guglielmina; Smiraglia, Claudio; Franzetti, Andrea

2017-05-01

Cryoconite holes are small ponds that form on the surface of glaciers that contain a dark debris, the cryoconite, at the bottom and host active ecological communities. Differences in the structure of bacterial communities have been documented among Arctic and mountain glaciers, and among glaciers in different areas of the world. In this study, we investigated the structure of bacterial communities of cryoconite holes of Baltoro Glacier, a large (62 km in length and 524 km 2 of surface) glacier of the Karakoram, by high-throughput sequencing of the V5-V6 hypervariable regions of the 16S rRNA gene. We found that Betaproteobacteria dominated bacterial communities, with large abundance of genera Polaromonas, probably thanks to its highly versatile metabolism, and Limnohabitans, which may have been favoured by the presence of supraglacial lakes in the area where cryoconite holes were sampled. Variation in bacterial communities among different sampling areas of the glacier could be explained by divergent selective processes driven by variation in environmental conditions, particularly pH, which was the only environmental variable that significantly affected the structure of bacterial communities. This variability may be due to both temporal and spatial patterns of variation in environmental conditions.

The Effects of Dynamical Rates on Species Coexistence in a Variable Environment: The Paradox of the Plankton Revisited.

PubMed

Li, Lina; Chesson, Peter

2016-08-01

Hutchinson's famous hypothesis for the "paradox of the plankton" has been widely accepted, but critical aspects have remained unchallenged. Hutchinson argued that environmental fluctuations would promote coexistence when the timescale for environmental change is comparable to the timescale for competitive exclusion. Using a consumer-resource model, we do find that timescales of processes are important. However, it is not the time to exclusion that must be compared with the time for environmental change but the time for resource depletion. Fast resource depletion, when resource consumption is favored for different species at different times, strongly promotes coexistence. The time for exclusion is independent of the rate of resource depletion. Therefore, the widely believed predictions of Hutchinson are misleading. Fast resource depletion, as determined by environmental conditions, ensures strong coupling of environmental processes and competition, which leads to enhancement over time of intraspecific competition relative to interspecific competition as environmental shifts favor different species at different times. This critical coupling is measured by the covariance between environment and competition. Changes in this quantity as densities change determine the stability of coexistence and provide the key to rigorous analysis, both theoretically and empirically, of coexistence in a variable environment. These ideas apply broadly to diversity maintenance in variable environments whether the issue is species diversity or genetic diversity and competition or apparent competition.

Environmental effects on resistance gene expression in milk stage popcorn kernels and associations with mycotoxin production

USDA-ARS?s Scientific Manuscript database

Like other forms of maize, popcorn is subject to increased levels of contamination by a variety of different mycotoxins under stress conditions, although levels generally are less than dent maize under comparable stress. Gene array analysis was used to determine expression differences of disease res...

Effects of feral horse herds on plant communities across a precipitation gradient

Treesearch

Laura Baur

2016-01-01

Feral horse herds in the western United States are managed with the goal of maintaining "a thriving natural ecological balance" with their environment. Because rangeland ecology is complex and grazers such as horses can have different effects under different environmental conditions, more data are needed to better inform Appropriate Management Levels...

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 have not been properly evaluated, are involved in the observed cross-taxon congruence. The approaches introduced here indicate that the prevalence of a significant association among taxa, after considering the environmental determinant, could indicate both the need to incorporate additional processes (e.g. biogeographic and evolutionary history or trophic interactions) and/or the existence of a shared trend in detection biases among taxa and regions.

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 only the environmental requirement numbers needed to do their jobs but do not necessarily have a programmatic-level understanding of how all of the environmental requirements fit together.

Camelot 3: Habitability criteria space research and design studio

NASA Technical Reports Server (NTRS)

Arroyo, F.; Budet, O.; Garcia, A.; Lee, J.; Lopez, R.; Lugo, R.; Mateo, A.; Mellado, R.; Mendez, H.; Ortiz, N.

1989-01-01

Acknowledging the importance of human beings on a mission to Mars, the University of Puerto Rico studied both psychological and physiological aspects. Different conditions necessary for human health and well-being were considered. As a result, habitability criteria were developed. The criteria are as follows: personal identification; social interaction; unpredictable conditions; contact with nature; mental landscapes; privacy; equalitarian conditions; variety; functionality; sensory stimulation; music and environmental sound; stability and security; comfort; and sense of orientation.

Condition and biochemical profile of blue mussels (Mytilus edulis L.) cultured at different depths in a cold water coastal environment

NASA Astrophysics Data System (ADS)

Gallardi, Daria; Mills, Terry; Donnet, Sebastien; Parrish, Christopher C.; Murray, Harry M.

2017-08-01

The growth and health of cultured blue mussels (Mytilus edulis) are affected by environmental conditions. Typically, culture sites are situated in sheltered areas near shore (i.e., < 1 km distance from land, < 20 m depth); however, land runoff, user conflicts and environmental impact in coastal areas are concerns and interest in developing deep water (> 20 m depth) mussel culture has been growing. This study evaluated the effect of culture depth on blue mussels in a cold water coastal environment (Newfoundland, Canada). Culture depth was examined over two years from September 2012 to September 2014; mussels from three shallow water (5 m) and three deep water (15 m) sites were compared for growth and biochemical composition; culture depths were compared for temperature and chlorophyll a. Differences between the two years examined were noted, possibly due to harsh winter conditions in the second year of the experiment. In both years shallow and deep water mussels presented similar condition; in year 2 deep water mussels had a significantly better biochemical profile. Lipid and glycogen analyses showed seasonal variations, but no significant differences between shallow and deep water were noted. Fatty acid profiles showed a significantly higher content of omega-3 s (20:5ω3; EPA) and lower content of bacterial fatty acids in deep water sites in year 2. Everything considered, deep water appeared to provide a more favorable environment for mussel growth than shallow water under harsher weather conditions.

Characterization of detonation soot produced during steady and overdriven conditions for three high explosive formulations

NASA Astrophysics Data System (ADS)

Podlesak, David W.; Huber, Rachel C.; Amato, Ronald S.; Dattelbaum, Dana M.; Firestone, Millicent A.; Gustavsen, Richard L.; Johnson, Carl E.; Mang, Joseph T.; Ringstrand, Bryan S.

2017-01-01

The detonation of high explosives (HE) produces a dense fluid of molecular gases and solid carbon. The solid detonation carbon contains various carbon allotropes such as detonation nanodiamonds, onion-like carbon, graphite and amorphous carbon, with the formation of the different forms dependent upon pressure, temperature and the environmental conditions of the detonation. We have collected solid carbon residues from controlled detonations of three HE formulations (Composition B-3, PBX 9501, and PBX 9502). Soot was collected from experiments designed to produce both steady and overdriven conditions, and from detonations in both an ambient (air) atmosphere and in an inert Ar atmosphere. Differences in solid carbon residues were quantified using X-ray photoelectron spectroscopy and carbon isotope measurements. Environmental conditions, HE formulation, and peak pressures influenced the amount of and isotopic composition of the carbon in the soot. Detonations in an Ar atmosphere produced greater amounts of carbon soot with lower δ13C values than those in ambient air. Therefore, solid carbon residues continued to evolve after detonation due to excess oxygen in the ambient air detonations. As well, higher peak pressures in overdriven conditions produced less carbon soot with, in general, higher δ13C values. Consequently, while overdriven conditions only produced peak pressures for a limited duration, it was enough to influence the composition of the solid carbon residues.

Silicification of the adaxial epidermis of leaves of a panicoid grass in relation to leaf position and section and environmental conditions.

PubMed

Fernández Honaine, M; Osterrieth, M L

2012-07-01

Many studies relate silica content in plants with internal or external factors; however, few works analyse the effect of these factors on the silicification of different cell types. In this study, we examined the effect of leaf section and leaf position, and environmental conditions on the percentages of silicified epidermal cells of a native Pampean panicoid grass, Bothriochloa laguroides D. C. Pilger. Two different environmental situations were selected for the collection of plants: a natural wetland and a quartzite quarry, located in the southeast Buenos Aires province, Argentina. Clarification and staining methodologies were applied so as to study the distribution of silicified cells in different sections of leaves of the plants collected. Two and three-factor anovas were applied to the data. Between 13% and 19% of total cells of the adaxial epidermis of leaf blades were silicified. Typical silica short cells were the largest contributor to total silicified cells (53-98%), while the second largest contributor was bulliform cells (0-30%). Percentages of total silicified cells were higher in superior than in inferior leaves, while values from leaf sections varied. When collection sites were compared, plants growing in Los Padres pond, where the silica content in soils is higher, had the higher percentage of silicified cells. Among all types of cell, bulliform cells showed differences in the proportion of silicified cells between leaf position and section and collection site. These results show that silica availability in soils is an important factor that conditions silica accumulation and overlaps with the transpiration effect. © 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.

Entropy generation method to quantify thermal comfort.

PubMed

Boregowda, S C; Tiwari, S N; Chaturvedi, S K

2001-12-01

The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a function of entropy generation. In order to verify the entropy-based thermal comfort model, human thermal physiological responses due to changes in ambient conditions are simulated using a well established and validated human thermal model developed at the Institute of Environmental Research of Kansas State University (KSU). The finite element based KSU human thermal computer model is being utilized as a "Computational Environmental Chamber" to conduct series of simulations to examine the human thermal responses to different environmental conditions. The output from the simulation, which include human thermal responses and input data consisting of environmental conditions are fed into the thermal comfort model. Continuous monitoring of thermal comfort in comfortable and extreme environmental conditions is demonstrated. The Objective Thermal Comfort values obtained from the entropy-based model are validated against regression based Predicted Mean Vote (PMV) values. Using the corresponding air temperatures and vapor pressures that were used in the computer simulation in the regression equation generates the PMV values. The preliminary results indicate that the OTCI and PMV values correlate well under ideal conditions. However, an experimental study is needed in the future to fully establish the validity of the OTCI formula and the model. One of the practical applications of this index is that could it be integrated in thermal control systems to develop human-centered environmental control systems for potential use in aircraft, mass transit vehicles, intelligent building systems, and space vehicles.

Entropy generation method to quantify thermal comfort

NASA Technical Reports Server (NTRS)

Boregowda, S. C.; Tiwari, S. N.; Chaturvedi, S. K.

2001-01-01

The present paper presents a thermodynamic approach to assess the quality of human-thermal environment interaction and quantify thermal comfort. The approach involves development of entropy generation term by applying second law of thermodynamics to the combined human-environment system. The entropy generation term combines both human thermal physiological responses and thermal environmental variables to provide an objective measure of thermal comfort. The original concepts and definitions form the basis for establishing the mathematical relationship between thermal comfort and entropy generation term. As a result of logic and deterministic approach, an Objective Thermal Comfort Index (OTCI) is defined and established as a function of entropy generation. In order to verify the entropy-based thermal comfort model, human thermal physiological responses due to changes in ambient conditions are simulated using a well established and validated human thermal model developed at the Institute of Environmental Research of Kansas State University (KSU). The finite element based KSU human thermal computer model is being utilized as a "Computational Environmental Chamber" to conduct series of simulations to examine the human thermal responses to different environmental conditions. The output from the simulation, which include human thermal responses and input data consisting of environmental conditions are fed into the thermal comfort model. Continuous monitoring of thermal comfort in comfortable and extreme environmental conditions is demonstrated. The Objective Thermal Comfort values obtained from the entropy-based model are validated against regression based Predicted Mean Vote (PMV) values. Using the corresponding air temperatures and vapor pressures that were used in the computer simulation in the regression equation generates the PMV values. The preliminary results indicate that the OTCI and PMV values correlate well under ideal conditions. However, an experimental study is needed in the future to fully establish the validity of the OTCI formula and the model. One of the practical applications of this index is that could it be integrated in thermal control systems to develop human-centered environmental control systems for potential use in aircraft, mass transit vehicles, intelligent building systems, and space vehicles.

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

NASA Astrophysics Data System (ADS)

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

2014-10-01

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

Five domains of environmental quality and infant mortality

EPA Science Inventory

The relationship between environmental conditions and human health varies by environmental media. In order to account for multiple ambient environmental conditions, we constructed an Environmental Quality Index (EQI) for health research. We used U.S. county level data representin...

Environmental quality and infant mortality

EPA Science Inventory

The relationship between environmental conditions and human health varies by environmental media. In order to account for multiple ambient environmental conditions, we constructed an Environmental Quality Index (EQI)for use in health research. We used u.s. county level data repre...

Environmental variation shifts the relationship between trees and scatterhoarders along the continuum from mutualism to antagonism.

PubMed

Sawaya, Gina M; Goldberg, Adam S; Steele, Michael A; Dalgleish, Harmony J

2018-05-01

The conditional mutualism between scatterhoarders and trees varies on a continuum from mutualism to antagonism and can change across time and space, and among species. We examined 4 tree species (red oak [Quercus rubra], white oak [Quercus alba], American chestnut [Castanea dentata] and hybrid chestnut [C. dentata × Castanea mollissima) across 5 sites and 3 years to quantify the variability in this conditional mutualism. We used a published model to compare the rates of seed emergence with and without burial to the probability that seeds will be cached and left uneaten by scatterhoarders to quantify variation in the conditional mutualism that can be explained by environmental variation among sites, years, species, and seed provenance within species. All species tested had increased emergence when buried. However, comparing benefits of burial to the probability of caching by scatterhoarders indicated a mutualism in red oak, while white oak was nearly always antagonistic. Chestnut was variable around the boundary between mutualism and antagonism, indicating a high degree of context dependence in the relationship with scatterhoarders. We found that different seed provenances did not vary in their potential for mutualism. Temperature did not explain microsite differences in seed emergence in any of the species tested. In hybrid chestnut only, emergence on the surface declined with soil moisture in the fall. By quantifying the variation in the conditional mutualism that was not caused by changes in scatterhoarder behavior, we show that environmental conditions and seed traits are an important and underappreciated component of the variation in the relationship between trees and scatterhoarders. © 2018 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Assessment of the toxic effect of pesticides on honey bee drone fertility using laboratory and semifield approaches: A case study of fipronil.

PubMed

Kairo, Guillaume; Poquet, Yannick; Haji, Haïthem; Tchamitchian, Sylvie; Cousin, Marianne; Bonnet, Marc; Pelissier, Michel; Kretzschmar, André; Belzunces, Luc P; Brunet, Jean-Luc

2017-09-01

Concern about the reproductive toxicity of plant protection products in honey bee reproducers is increasing. Because the reproductive capacity of honey bees is not currently considered during the risk assessment procedure performed during plant protection product registration, it is important to provide methods to assess such potential impairments. To achieve this aim, we used 2 different approaches that involved semifield and laboratory conditions to study the impact of fipronil on drone fertility. For each approach, the drones were reared for 20 d, from emergence to sexual maturity, and exposed to fipronil via a contaminated sugar solution. In both groups, the effects of fipronil were determined by studying life traits and fertility indicators. The results showed that the survival and maturity rates of the drones were better under laboratory conditions than under semifield conditions. Moreover, the drones reared under laboratory conditions produced more seminal fluid. Although these differences could be explained by environmental factors that may vary under semifield conditions, it was found that regardless of the approach used, fipronil did not affect survival rates, maturity rates, or semen volumes, whereas it did affect fertility by inducing a decrease in spermatozoa quantity that was associated with an increase in spermatozoa mortality. These results confirm that fipronil affects drone fertility and support the relevance of each approach for assessing the potential reproductive toxicity of plant protection products in honey bees. Environ Toxicol Chem 2017;36:2345-2351. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Getting through to circadian oscillators: why use constant routines?

NASA Technical Reports Server (NTRS)

Duffy, Jeanne F.; Dijk, Derk-Jan

2002-01-01

Overt 24-h rhythmicity is composed of both exogenous and endogenous components, reflecting the product of multiple (periodic) feedback loops with a core pacemaker at their center. Researchers attempting to reveal the endogenous circadian (near 24-h) component of rhythms commonly conduct their experiments under constant environmental conditions. However, even under constant environmental conditions, rhythmic changes in behavior, such as food intake or the sleep-wake cycle, can contribute to observed rhythmicity in many physiological and endocrine variables. Assessment of characteristics of the core circadian pacemaker and its direct contribution to rhythmicity in different variables, including rhythmicity in gene expression, may be more reliable when such periodic behaviors are eliminated or kept constant across all circadian phases. This is relevant for the assessment of the status of the circadian pacemaker in situations in which the sleep-wake cycle or food intake regimes are altered because of external conditions, such as in shift work or jet lag. It is also relevant for situations in which differences in overt rhythmicity could be due to changes in either sleep oscillatory processes or circadian rhythmicity, such as advanced or delayed sleep phase syndromes, in aging, or in particular clinical conditions. Researchers studying human circadian rhythms have developed constant routine protocols to assess the status of the circadian pacemaker in constant behavioral and environmental conditions, whereas this technique is often thought to be unnecessary in the study of animal rhythms. In this short review, the authors summarize constant routine methodology and what has been learned from constant routines and argue that animal and human circadian rhythm researchers should (continue to) use constant routines as a step on the road to getting through to central and peripheral circadian oscillators in the intact organism.

Frequency-Limiting Effects on Speech and Environmental Sound Identification for Cochlear Implant and Normal Hearing Listeners

PubMed Central

Chang, Son-A; Won, Jong Ho; Kim, HyangHee; Oh, Seung-Ha; Tyler, Richard S.; Cho, Chang Hyun

2018-01-01

Background and Objectives It is important to understand the frequency region of cues used, and not used, by cochlear implant (CI) recipients. Speech and environmental sound recognition by individuals with CI and normal-hearing (NH) was measured. Gradients were also computed to evaluate the pattern of change in identification performance with respect to the low-pass filtering or high-pass filtering cutoff frequencies. Subjects and Methods Frequency-limiting effects were implemented in the acoustic waveforms by passing the signals through low-pass filters (LPFs) or high-pass filters (HPFs) with seven different cutoff frequencies. Identification of Korean vowels and consonants produced by a male and female speaker and environmental sounds was measured. Crossover frequencies were determined for each identification test, where the LPF and HPF conditions show the identical identification scores. Results CI and NH subjects showed changes in identification performance in a similar manner as a function of cutoff frequency for the LPF and HPF conditions, suggesting that the degraded spectral information in the acoustic signals may similarly constraint the identification performance for both subject groups. However, CI subjects were generally less efficient than NH subjects in using the limited spectral information for speech and environmental sound identification due to the inefficient coding of acoustic cues through the CI sound processors. Conclusions This finding will provide vital information in Korean for understanding how different the frequency information is in receiving speech and environmental sounds by CI processor from normal hearing. PMID:29325391

Frequency-Limiting Effects on Speech and Environmental Sound Identification for Cochlear Implant and Normal Hearing Listeners.

PubMed

Chang, Son-A; Won, Jong Ho; Kim, HyangHee; Oh, Seung-Ha; Tyler, Richard S; Cho, Chang Hyun

2017-12-01

It is important to understand the frequency region of cues used, and not used, by cochlear implant (CI) recipients. Speech and environmental sound recognition by individuals with CI and normal-hearing (NH) was measured. Gradients were also computed to evaluate the pattern of change in identification performance with respect to the low-pass filtering or high-pass filtering cutoff frequencies. Frequency-limiting effects were implemented in the acoustic waveforms by passing the signals through low-pass filters (LPFs) or high-pass filters (HPFs) with seven different cutoff frequencies. Identification of Korean vowels and consonants produced by a male and female speaker and environmental sounds was measured. Crossover frequencies were determined for each identification test, where the LPF and HPF conditions show the identical identification scores. CI and NH subjects showed changes in identification performance in a similar manner as a function of cutoff frequency for the LPF and HPF conditions, suggesting that the degraded spectral information in the acoustic signals may similarly constraint the identification performance for both subject groups. However, CI subjects were generally less efficient than NH subjects in using the limited spectral information for speech and environmental sound identification due to the inefficient coding of acoustic cues through the CI sound processors. This finding will provide vital information in Korean for understanding how different the frequency information is in receiving speech and environmental sounds by CI processor from normal hearing.

A Trainable Hearing Aid Algorithm Reflecting Individual Preferences for Degree of Noise-Suppression, Input Sound Level, and Listening Situation.

PubMed

Yoon, Sung Hoon; Nam, Kyoung Won; Yook, Sunhyun; Cho, Baek Hwan; Jang, Dong Pyo; Hong, Sung Hwa; Kim, In Young

2017-03-01

In an effort to improve hearing aid users' satisfaction, recent studies on trainable hearing aids have attempted to implement one or two environmental factors into training. However, it would be more beneficial to train the device based on the owner's personal preferences in a more expanded environmental acoustic conditions. Our study aimed at developing a trainable hearing aid algorithm that can reflect the user's individual preferences in a more extensive environmental acoustic conditions (ambient sound level, listening situation, and degree of noise suppression) and evaluated the perceptual benefit of the proposed algorithm. Ten normal hearing subjects participated in this study. Each subjects trained the algorithm to their personal preference and the trained data was used to record test sounds in three different settings to be utilized to evaluate the perceptual benefit of the proposed algorithm by performing the Comparison Mean Opinion Score test. Statistical analysis revealed that of the 10 subjects, four showed significant differences in amplification constant settings between the noise-only and speech-in-noise situation ( P <0.05) and one subject also showed significant difference between the speech-only and speech-in-noise situation ( P <0.05). Additionally, every subject preferred different β settings for beamforming in all different input sound levels. The positive findings from this study suggested that the proposed algorithm has potential to improve hearing aid users' personal satisfaction under various ambient situations.

Forest operations in coppice: Environmental assessment of two different logging methods.

PubMed

Laschi, Andrea; Marchi, Enrico; González-García, Sara

2016-08-15

Wood is a renewable resource and it actively contributes to enhance energy production under a sustainable perspective. However, harvesting, transport and use of wood imply several consequences and impacts on environment. There are different ways for managing forests dedicated to wood production and a sustainable approach is fundamental to preserve the resource. In this context, Life Cycle Assessment (LCA) is a useful tool for estimating the environmental impacts related to renewable resources. Traditional coppice is a common approach for forest management in several areas, including southern Europe and, specifically, Italy, Spain and the Balkans. Due to different terrain conditions, different types of forest operations are considered for wood extraction from coppices, where the main product is firewood used in domestic heating. The aim of this work was to compare the main common systems for firewood production in two different terrain conditions ('flat/low steep' and 'steep/very steep' terrains), in a representative environment for Mediterranean area, located in central Italy, by means of LCA. Seven different impact categories were evaluated in a cradle-to-gate perspective taking into account all the operations carried out from the trees felling to the firewood storage at factory. Results showed that the extraction phase was the most important in terms of environmental burdens in firewood production and the use of heavy and high-power machines negatively influenced the emissions compared with manual operations. Finally, considering the general low-inputs involved in wood production in coppice, the transport of workers by car to the work site resulted on consistent contributions into environmental burdens. An additional analysis about the modifications of CH4 and N2O exchanges between soil and atmosphere, due to soil compaction in the extraction phase, was made and based on bibliographic information. Results showed a sensible difference between disturbed and undisturbed soil. Copyright © 2016 Elsevier B.V. All rights reserved.

Nitrous Oxide Production and Fluxes from Coastal Sediments under Varying Environmental Conditions

NASA Astrophysics Data System (ADS)

Ziebis, W.; Wankel, S. D.; de Beer, D.; Dentinger, J.; Buchwald, C.; Charoenpong, C.

2014-12-01

Although coastal zones represent important contributors to the increasing levels of atmospheric nitrous oxide (N2O), it is still unclear which role benthic processes play and whether marine sediments represent sinks or sources for N2O, since interactions among closely associated microbial groups lead to a high degree of variability. In addition, coastal areas are extremely dynamic regions, often exposed to increased nutrient loading and conditions of depleted oxygen. We investigated benthic N2O fluxes and how environmental conditions affect N2O production in different sediments at 2 different geographical locations (German Wadden Sea, a California coastal lagoon). At each location, a total of 32 sediment cores were taken in areas that differed in sediment type, organic content and pore-water nutrient concentrations, as well as in bioturbation activity. Parallel cores were incubated under in-situ conditions, low oxygen and increased nitrate levels for 10 days. Zones of N2O production and consumption were identified in intact cores by N2O microprofiles at the beginning and end of the experiments. In a collaborative effort to determine the dominant sources of N2O, samples were taken throughout the course of the experiments for the determination of the isotopic composition of N2O (as well as nitrate, nitrite and ammonium). Our results indicate that both, nitrate addition and low oxygen conditions in the overlying water, caused an increase of subsurface N2O production in most sediments, with a high variability between different sediment types. N2O production in the sediments was accompanied by N2O consumption, reducing the fluxes to the water column. In general, organic rich sediments showed the strongest response to environmental changes with increased production and efflux of N2O into the overlying water. Bioturbation activity added to the complexity of N2O dynamics by an increase in nitrification-denitrification processes, as well as enhanced pore-water transport. The results will be used in a metabolic modeling approach that will allow numerical simulation and prediction of sedimentary N2O dynamics.

Water-Wisteria as an ideal plant to study heterophylly in higher aquatic plants.

PubMed

Li, Gaojie; Hu, Shiqi; Yang, Jingjing; Schultz, Elizabeth A; Clarke, Kurtis; Hou, Hongwei

2017-08-01

The semi-aquatic plant Water-Wisteria is suggested as a new model to study heterophylly due to its many advantages and typical leaf phenotypic plasticity in response to environmental factors and phytohormones. Water-Wisteria, Hygrophila difformis (Acanthaceae), is a fast growing semi-aquatic plant that exhibits a variety of leaf shapes, from simple leaves to highly branched compound leaves, depending on the environment. The phenomenon by which leaves change their morphology in response to environmental conditions is called heterophylly. In order to investigate the characteristics of heterophylly, we assessed the morphology and anatomy of Hygrophila difformis in different conditions. Subsequently, we verified that phytohormones and environmental factors can induce heterophylly and found that Hygrophila difformis is easily propagated vegetatively through either leaf cuttings or callus induction, and the callus can be easily transformed by Agrobacterium tumefaciens. These results suggested that Hygrophila difformis is a good model plant to study heterophylly in higher aquatic plants.

Global Patterns in the Implementation of Payments for Environmental Services

PubMed Central

Ezzine-de-Blas, Driss; Wunder, Sven; Ruiz-Pérez, Manuel; Moreno-Sanchez, Rocio del Pilar

2016-01-01

Assessing global tendencies and impacts of conditional payments for environmental services (PES) programs is challenging because of their heterogeneity, and scarcity of comparative studies. This meta-study systematizes 55 PES schemes worldwide in a quantitative database. Using categorical principal component analysis to highlight clustering patterns, we reconfirm frequently hypothesized differences between public and private PES schemes, but also identify diverging patterns between commercial and non-commercial private PES vis-à-vis their service focus, area size, and market orientation. When do these PES schemes likely achieve significant environmental additionality? Using binary logistical regression, we find additionality to be positively influenced by three theoretically recommended PES ‘best design’ features: spatial targeting, payment differentiation, and strong conditionality, alongside some contextual controls (activity paid for and implementation time elapsed). Our results thus stress the preeminence of customized design over operational characteristics when assessing what determines the outcomes of PES implementation. PMID:26938065

Smoking at the workplace: Effects of genetic and environmental causal accounts on attitudes towards smoking employees and restrictive policies

PubMed Central

Dar-Nimrod, Ilan; Zuckerman, Miron; Duberstein, Paul

2014-01-01

People hold diverse beliefs regarding the etiologies of individual and group differences in behaviors which, in turn, might affect their attitudes and behaviors. It is important to establish how perceived etiologies for smoking might affect the effectiveness of policy initiatives and prevention efforts. The present study assessed whether exposure to genetic vs. environmental accounts for smoking affects attitudes towards a) workplace-related smoking policies and b) smokers at the workplace. Results indicate that exposure to a genetic explanation led to stronger objections to a smoking restrictive policy compared with a non-genetic explanation. Additionally, participants in the genetic condition were more accepting of a smoker in the workplace than in the environmental condition. Evidently, beliefs about the etiology of smoking influence a range of attitudes related to smokers and smoking related policies. PMID:25530710

Atmospheric radiance interpolation for the modeling of hyperspectral data

NASA Astrophysics Data System (ADS)

Fuehrer, Perry; Healey, Glenn; Rauch, Brian; Slater, David; Ratkowski, Anthony

2008-04-01

The calibration of data from hyperspectral sensors to spectral radiance enables the use of physical models to predict measured spectra. Since environmental conditions are often unknown, material detection algorithms have emerged that utilize predicted spectra over ranges of environmental conditions. The predicted spectra are typically generated by a radiative transfer (RT) code such as MODTRAN TM. Such techniques require the specification of a set of environmental conditions. This is particularly challenging in the LWIR for which temperature and atmospheric constituent profiles are required as inputs for the RT codes. We have developed an automated method for generating environmental conditions to obtain a desired sampling of spectra in the sensor radiance domain. Our method provides a way of eliminating the usual problems encountered, because sensor radiance spectra depend nonlinearly on the environmental parameters, when model conditions are specified by a uniform sampling of environmental parameters. It uses an initial set of radiance vectors concatenated over a set of conditions to define the mapping from environmental conditions to sensor spectral radiance. This approach enables a given number of model conditions to span the space of desired radiance spectra and improves both the accuracy and efficiency of detection algorithms that rely upon use of predicted spectra.

Foraging in corallivorous butterflyfish varies with wave exposure

NASA Astrophysics Data System (ADS)

Noble, Mae M.; Pratchett, Morgan S.; Coker, Darren J.; Cvitanovic, Christopher; Fulton, Christopher J.

2014-06-01

Understanding the foraging patterns of reef fishes is crucial for determining patterns of resource use and the sensitivity of species to environmental change. While changes in prey availability and interspecific competition have been linked to patterns of prey selection, body condition, and survival in coral reef fishes, rarely has the influence of abiotic environmental conditions on foraging been considered. We used underwater digital video to explore how prey availability and wave exposure influence the behavioural time budgets and prey selectivity of four species of obligate coral-feeding butterflyfishes. All four species displayed high selectivity towards live hard corals, both in terms of time invested and frequency of searching and feeding events. However, our novel analysis revealed that such selectivity was sensitive to wave exposure in some species, despite there being no significant differences in the availability of each prey category across exposures. In most cases, these obligate corallivores increased their selectivity towards their most favoured prey types at sites of high wave exposure. This suggests there are costs to foraging under different wave environments that can shape the foraging patterns of butterflyfishes in concert with other conditions such as prey availability, interspecific competition, and territoriality. Given that energy acquisition is crucial to the survival and fitness of fishes, we highlight how such environmental forcing of foraging behaviour may influence the ecological response of species to the ubiquitous and highly variable wave climates of shallow coral reefs.

Variations of vessel diameter and δ13C in false rings of Arbutus unedo L. reflect different environmental conditions.

PubMed

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

2010-12-01

Woody species in Mediterranean ecosystems form intra-annual density fluctuations (IADFs) in tree rings in response to changes in environmental conditions, especially water availability. Dendrochronology, quantitative wood anatomy and high-resolution isotopic analysis (using a laser ablation technique) were used to characterize IADFs in Arbutus unedo shrubs grown on two sites with different water availability on the island of Elba (Italy). Our findings show that IADF characterization can provide information about the relationship between environmental factors and tree growth at the seasonal level. At the more xeric site, IADFs mainly located in the early and middle parts of the annual ring, showed a decrease in vessel size and an increase in δ(13) C as a result of drought deficit. Opposite trends were found at the more mesic site, with IADFs located at the end of the ring and associated with a lower δ(13) C. Moreover, at the first site, IADFs are induced by drought deficit, while at the second site IADFs are linked with the regrowth in the last part of the growing season triggered by favourable wet conditions. This combined approach is a promising way for dating problematic wood samples and interpreting the phenomena that trigger the formation of IADFs in the Mediterranean environment. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Study the Cyclic Plasticity Behavior of 508 LAS under Constant, Variable and Grid-Load-Following Loading Cycles for Fatigue Evaluation of PWR Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohanty, Subhasish; Barua, Bipul; Soppet, William K.

This report provides an update of an earlier assessment of environmentally assisted fatigue for components in light water reactors. This report is a deliverable in September 2016 under the work package for environmentally assisted fatigue under DOE’s Light Water Reactor Sustainability program. In an April 2016 report, we presented a detailed thermal-mechanical stress analysis model for simulating the stress-strain state of a reactor pressure vessel and its nozzles under grid-load-following conditions. In this report, we provide stress-controlled fatigue test data for 508 LAS base metal alloy under different loading amplitudes (constant, variable, and random grid-load-following) and environmental conditions (in airmore » or pressurized water reactor coolant water at 300°C). Also presented is a cyclic plasticity-based analytical model that can simultaneously capture the amplitude and time dependency of the component behavior under fatigue loading. Results related to both amplitude-dependent and amplitude-independent parameters are presented. The validation results for the analytical/mechanistic model are discussed. This report provides guidance for estimating time-dependent, amplitude-independent parameters related to material behavior under different service conditions. The developed mechanistic models and the reported material parameters can be used to conduct more accurate fatigue and ratcheting evaluation of reactor components.« less

Effects of alkalinity and salinity at low and high light intensity on hydrogen isotope fractionation of long-chain alkenones produced by Emiliania huxleyi

NASA Astrophysics Data System (ADS)

Weiss, Gabriella M.; Pfannerstill, Eva Y.; Schouten, Stefan; Sinninghe Damsté, Jaap S.; van der Meer, Marcel T. J.

2017-12-01

Over the last decade, hydrogen isotopes of long-chain alkenones have been shown to be a promising proxy for reconstructing paleo sea surface salinity due to a strong hydrogen isotope fractionation response to salinity across different environmental conditions. However, to date, the decoupling of the effects of alkalinity and salinity, parameters that co-vary in the surface ocean, on hydrogen isotope fractionation of alkenones has not been assessed. Furthermore, as the alkenone-producing haptophyte, Emiliania huxleyi, is known to grow in large blooms under high light intensities, the effect of salinity on hydrogen isotope fractionation under these high irradiances is important to constrain before using δDC37 to reconstruct paleosalinity. Batch cultures of the marine haptophyte E. huxleyi strain CCMP 1516 were grown to investigate the hydrogen isotope fractionation response to salinity at high light intensity and independently assess the effects of salinity and alkalinity under low-light conditions. Our results suggest that alkalinity does not significantly influence hydrogen isotope fractionation of alkenones, but salinity does have a strong effect. Additionally, no significant difference was observed between the fractionation responses to salinity recorded in alkenones grown under both high- and low-light conditions. Comparison with previous studies suggests that the fractionation response to salinity in culture is similar under different environmental conditions, strengthening the use of hydrogen isotope fractionation as a paleosalinity proxy.

Impact of environmental conditions and chemicals on the neuronal epigenome.

PubMed

Del Blanco, Beatriz; Barco, Angel

2018-06-15

During development, chromatin changes contribute to establishing and maintaining the distinct gene-expression profiles of each individual cell type in a multicellular organism. This feat is especially remarkable in the human brain considering the sheer number of distinct cell types that make up this organ. This epigenetic programing is sensitive to environmental influences such as the presence of toxicants, diet, temperature, maternal behavior and many other external factors that can lead to sustained differences in neuronal gene expression. Here, we review a number of studies that demonstrate the existence of these environmental fingerprints in the neuronal epigenome and discuss the current challenges and prospects of environmental neuroepigenetics research. Copyright © 2018 Elsevier Ltd. All rights reserved.

Generalizing genetical genomics: getting added value from environmental perturbation.

PubMed

Li, Yang; Breitling, Rainer; Jansen, Ritsert C

2008-10-01

Genetical genomics is a useful approach for studying the effect of genetic perturbations on biological systems at the molecular level. However, molecular networks depend on the environmental conditions and, thus, a comprehensive understanding of biological systems requires studying them across multiple environments. We propose a generalization of genetical genomics, which combines genetic and sensibly chosen environmental perturbations, to study the plasticity of molecular networks. This strategy forms a crucial step toward understanding why individuals respond differently to drugs, toxins, pathogens, nutrients and other environmental influences. Here we outline a strategy for selecting and allocating individuals to particular treatments, and we discuss the promises and pitfalls of the generalized genetical genomics approach.

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

NASA Astrophysics Data System (ADS)

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

2014-05-01

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

Urban-rural status affects associations between overall environmental quality and cancer incidence

EPA Science Inventory

The relationship between environmental conditions and human health varies by urbanicity. To estimate ambient environmental conditions, an Environmental Quality Index (EQI) for 2000-2005 was constructed by the Environmental Protection Agency using county-level data representing fi...

The effect of probe choice and solution conditions on the apparent photoreactivity of dissolved organic matter.

PubMed

Maizel, Andrew C; Remucal, Christina K

2017-08-16

Excited triplet states of dissolved organic matter ( 3 DOM) are quantified directly with the species-specific probes trans,trans-hexadienoic acid (HDA) and 2,4,6-trimethylphenol (TMP), and indirectly with the singlet oxygen ( 1 O 2 ) probe furfuryl alcohol (FFA). Although previous work suggests that these probe compounds may be sensitive to solution conditions, including dissolved organic carbon concentration ([DOC]) and pH, and may quantify different 3 DOM subpopulations, the probes have not been systematically compared. Therefore, we quantify the apparent photoreactivity of diverse environmental waters using HDA, TMP, and FFA. By conducting experiments under ambient [DOC] and pH, with standardized [DOC] and pH, and with solid phase extraction isolates, we demonstrate that much of the apparent dissimilarity in photochemical measurements is attributable to solution conditions, rather than intrinsic differences in 3 DOM production. In general, apparent quantum yields (Φ 1 O 2 ≥ Φ 3 DOM,TMP ≫ Φ 3 DOM,HDA ) and pseudo-steady state concentrations ([ 1 O 2 ] ss > [ 3 DOM] ss,TMP > [ 3 DOM] ss,HDA ) show consistent relationships in all waters under standardized conditions. However, intrinsic differences in 3 DOM photoreactivity are apparent between DOM from diverse sources, as seen in the higher Φ 1 O 2 and lower Φ 3 DOM,TMP of wastewater effluents compared with oligotrophic lakes. Additionally, while conflicting trends in photoreactivity are observed under ambient conditions, all probes observe quantum yields increasing from surface wetlands to terrestrially influenced waters to oligotrophic lakes under standardized conditions. This work elucidates how probe selection and solution conditions influence the apparent photoreactivity of environmental waters and confirms that 3 DOM or 1 O 2 probes cannot be used interchangeably in waters that vary in [DOC], pH, or DOM source.

Current research trend on urban sewerage system in China

NASA Astrophysics Data System (ADS)

Ning, Yun-Fang; Dong, Wen-Yi; Lin, Lu-Sheng; Zhang, Qian

2017-03-01

The research emphasis has always been on sewerage treatment technology in China, though urban drainage system has gained little attention. In the context of urban drainage system and the problem associated with rain, the focus is still mainly toward the simple “emissions”. While the relationship between conservation and utilization of rainwater resources and urban ecology are popular, the relationship between rainwater discharge and non-point source pollution are often neglected. The reasonable choice of sewerage system is dependent on the collection and discharge of urban sewerage, the applicability and economic benefits, along with the ability to meet the water quality requirements and environmental protection. This paper analyzes and summarizes the development of urban drainage system in china, and introduces different drainage forms. The choice of drainage system should be based on the overall planning of the city, environmental protection requirements, the local natural conditions and water conditions, urban sewerage and water quality, the original drainage facilities, and local climatic conditions. It must be comprehensive to meet the environmental protection requirements, through technical and economic comparison.

Spawning stock and recruitment in North Sea cod shaped by food and climate

PubMed Central

Olsen, Esben Moland; Ottersen, Geir; Llope, Marcos; Chan, Kung-Sik; Beaugrand, Grégory; Stenseth, Nils Chr.

2011-01-01

In order to provide better fisheries management and conservation decisions, there is a need to discern the underlying relationship between the spawning stock and recruitment of marine fishes, a relationship which is influenced by the environmental conditions. Here, we demonstrate how the environmental conditions (temperature and the food availability for fish larvae) influence the stock–recruitment relationship and indeed what kind of stock–recruitment relationship we might see under different environmental conditions. Using unique zooplankton data from the Continuous Plankton Recorder, we find that food availability (i.e. zooplankton) in essence determines which model applies for the once large North Sea cod (Gadus morhua) stock. Further, we show that recruitment is strengthened during cold years and weakened during warm years. Our combined model explained 45 per cent of the total variance in cod recruitment, while the traditional Ricker and Beverton–Holt models only explained about 10 per cent. Specifically, our approach predicts that a full recovery of the North Sea cod stock might not be expected until the environment becomes more favourable. PMID:20810442

Hygrothermomechanical evaluation of transverse filament tape epoxy/polyester fiberglass composites

NASA Technical Reports Server (NTRS)

Lark, R. L.; Chamis, C. C.

1983-01-01

The static and cyclic load behavior of transverse filament tape (TFT) fiberglass/epoxy and TFY fiberglass/polyester composites, intended for use in the design of low-cost wind turbine blades, are presented. The data behavior is also evaluated with respect to predicted properties based on an integrated hygrothermomechanical response theory. Experimental TFT composite data were developed by the testing of laminates made by using composite layups typical of those used for the fabrication of TFT fiberglass wind turbine blades. Static properties include tension, compression, and interlaminar shear strengths at ambient conditions and at high humidity/elevated temperature conditions after a 500 hour exposure. Cyclic fatigue data were obtained using similar environmental conditions and a range of cyclic stresses. The environmental (temperature and moisture) and cyclic load effects on composite strength degradation are subsequently compared with the predictions obtained by using the composite life/durability theory. The results obtained show that the predicted hygrothermomechanical environmental effects on TFT composites are in good agreement with measured data for various properties including fatigue at different cyclic stresses.

In-Situ Quantification of the Interfacial Rheological Response of Bacterial Biofilms to Environmental Stimuli

PubMed Central

Rühs, Patrick A.; Böni, Lukas; Fuller, Gerald G.; Inglis, R. Fredrik; Fischer, Peter

2013-01-01

Understanding the numerous factors that can affect biofilm formation and stability remain poorly understood. One of the major limitations is the accurate measurement of biofilm stability and cohesiveness in real-time when exposed to changing environmental conditions. Here we present a novel method to measure biofilm strength: interfacial rheology. By culturing a range of bacterial biofilms on an air-liquid interface we were able to measure their viscoelastic growth profile during and after biofilm formation and subsequently alter growth conditions by adding surfactants or changing the nutrient composition of the growth medium. We found that different bacterial species had unique viscoelastic growth profiles, which was also highly dependent on the growth media used. We also found that we could reduce biofilm formation by the addition of surfactants or changing the pH, thereby altering the viscoelastic properties of the biofilm. Using this technique we were able to monitor changes in viscosity, elasticity and surface tension online, under constant and varying environmental conditions, thereby providing a complementary method to better understand the dynamics of both biofilm formation and dispersal. PMID:24244319

Working conditions, psychosocial environmental factors, and depressive symptoms among wage workers in South Korea

PubMed Central

Sohn, Minsung; Choi, Mankyu

2016-01-01

Background In South Korea, the number of workers suffering from mental illnesses, such as depression, has rapidly increased. There is growing concern about depressive symptoms being associated with both working conditions and psychosocial environmental factors. Objectives To investigate potential psychosocial environmental moderators in the relationship between working conditions and occupational depressive symptoms among wage workers. Methods Data were obtained from the wage worker respondents (n = 4,095) of the Korean National Health and Nutrition Examination Survey of 2009. First, chi-square tests confirmed the differences in working conditions and psychosocial characteristics between depressive and non-depressive groups. Second, multivariate logistic regression analysis was performed to examine the moderating effects of the psychosocial environmental factors between working conditions and depressive symptoms. Results After adjusting for potential covariates, the likelihood of depressive symptomatology was high among respondents who had dangerous jobs and flexible work hours compared to those who had standard jobs and fixed daytime work hours (OR = 1.66 and 1.59, respectively). Regarding psychosocial factors, respondents with high job demands, low job control, and low social support were more likely to have depressive symptoms (OR = 1.26, 1.58 and 1.61, respectively). Conclusions There is a need to develop non-occupational intervention programs, which provide workers with training about workplace depression and improve social support, and the programs should provide time for employees to have active communication. Additionally, companies should provide employees with support to access mental healthcare thereby decreasing the occurrence of workplace depression. PMID:27373792

ARTI refrigerant database. Quarterly report, March--May 1997

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calm, J.M.

1997-05-01

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information an older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some maymore » be added at a later date.« less

Systems and methods for pressure and temperature measurement

DOEpatents

Challener, William Albert; Airey, Li

2016-12-06

A measurement system in one embodiment includes an acquisition module and a determination module. The acquisition module is configured to acquire resonant frequency information corresponding to a sensor disposed in a remote location from the acquisition module. The resonant frequency information includes first resonant frequency information for a first resonant frequency of the sensor corresponding to environmental conditions of the remote location, and also includes second resonant frequency information for a different, second resonant frequency of the sensor corresponding to the environmental conditions of the remote location. The determination module is configured to use the first resonant frequency information and the second resonant frequency information to determine the temperature and the pressure at the remote location.

Supporting data for Environmental Trends

USGS Publications Warehouse

Tunstall, D.B.

1983-01-01

Information has been compiled as a companion document to ' Environmental Trends ' to provide analysts and researchers with statistical data to understand better how natural and man-made environments were changing. Subjects include land and climate; wetlands; wild areas; historic places; risk zones; settlement patterns; housing units; housing conditions; neighborhood conditions; transportation systems, including use and impacts on the environment such as noise, energy consumption; material use and solid waste; toxic substances, including radiation; cropland , forests and rangeland; wildlife, including extinct, threatened and endangered species; energy; water resources, water quality and air quality; and the biosphere. Statistics in the tables were taken from various published and unpublished sources. Therefore, the number of significant figures for the same information may differ. (Author 's abstract)

Multi-technique approach for qualitative and quantitative characterization of furazidin degradation kinetics under alkaline conditions.

PubMed

Bērziņš, Kārlis; Kons, Artis; Grante, Ilze; Dzabijeva, Diana; Nakurte, Ilva; Actiņš, Andris

2016-09-10

Degradation of drug furazidin was studied under different conditions of environmental pH (11-13) and temperature (30-60°C). The novel approach of hybrid hard- and soft-multivariate curve resolution-alternating least squares (HS-MCR-ALS) method was applied to UV-vis spectral data to determine a valid kinetic model and kinetic parameters of the degradation process. The system was found to be comprised of three main species and best characterized by two consecutive first-order reactions. Furazidin degradation rate was found to be highly dependent on the applied environmental conditions, showing more prominent differences between both degradation steps towards higher pH and temperature. Complimentary qualitative analysis of the degradation process was carried out using HPLC-DAD-TOF-MS. Based on the obtained chromatographic and mass spectrometric results, as well as additional computational analysis of the species (theoretical UV-vis spectra calculations utilizing TD-DFT methodology), the operating degradation mechanism was proposed to include formation of a 5-hydroxyfuran derivative, followed by complete hydrolysis of furazidin hydantoin ring. Copyright © 2016 Elsevier B.V. All rights reserved.

The influence of environmental conditions on lead transfer from spent gunshot to sediments and water: Other routes for Pb poisoning.

PubMed

Binkowski, Łukasz J

2017-11-01

Lead (Pb) from spent gunshot and fishing sinkers is recognized as the main source of Pb poisoning among waterfowl. It is also suspected to directly pollute water and sediments, but no appropriate, comprehensive evaluation of this issue has so far been carried out. An experiment on Pb pellets in microcosms (n = 160) with two sediment types (mud and gravel), three water pH values (4, 7 and 9) and two wind levels (wind and windless simulation) was therefore run. Substantial differences in Pb transfer (measured with ICP-OES) between sediment types and pH levels of water were observed. Simulated wind conditions were a significant factor only for some variables and circumstances. The strongest Pb deposit to water and sediments occurred in mud microcosms with water of pH value of 4. Median pellet erosion during the experiment differed little between sediment types. The experiment revealed that Pb transfer from spent gunshot to the environment occurs only in specific environmental conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Boldness in a deep sea hermit crab to simulated tactile predator attacks is unaffected by ocean acidification

NASA Astrophysics Data System (ADS)

Kim, Tae Won; Barry, James P.

2016-09-01

Despite rapidly growing interest in the effects of ocean acidification on marine animals, the ability of deep-sea animals to acclimate or adapt to reduced pH conditions has received little attention. Deep-sea species are generally thought to be less tolerant of environmental variation than shallow-living species because they inhabit relatively stable conditions for nearly all environmental parameters. To explore whether deep-sea hermit crabs ( Pagurus tanneri) can acclimate to ocean acidification over several weeks, we compared behavioral "boldness," measured as time taken to re-emerge from shells after a simulated predatory attack by a toy octopus, under ambient (pH ˜7.6) and expected future (pH ˜7.1) conditions. The boldness measure for crab behavioral responses did not differ between different pH treatments, suggesting that future deep-sea acidification would not influence anti-predatory behavior. However, we did not examine the effects of olfactory cues released by predators that may affect hermit crab behavior and could be influenced by changes in the ocean carbonate system driven by increasing CO2 levels.

Abiotic degradation of plastic films

NASA Astrophysics Data System (ADS)

Ángeles-López, Y. G.; Gutiérrez-Mayen, A. M.; Velasco-Pérez, M.; Beltrán-Villavicencio, M.; Vázquez-Morillas, A.; Cano-Blanco, M.

2017-01-01

Degradable plastics have been promoted as an option to mitigate the environmental impacts of plastic waste. However, there is no certainty about its degradability under different environmental conditions. The effect of accelerated weathering (AW), natural weathering (NW) and thermal oxidation (TO) on different plastics (high density polyethylene, HDPE; oxodegradable high density polyethylene, HDPE-oxo; compostable plastic, Ecovio ® metalized polypropylene, PP; and oxodegradable metalized polypropylene, PP-oxo) was studied. Plastics films were exposed to AW per 110 hours; to NW per 90 days; and to TO per 30 days. Plastic films exposed to AW and NW showed a general loss on mechanical properties. The highest reduction in elongation at break on AW occurred to HDPE-oxo (from 400.4% to 20.9%) and was higher than 90% for HDPE, HDPE-oxo, Ecovio ® and PP-oxo in NW. No substantial evidence of degradation was found on plastics exposed to TO. Oxo-plastics showed higher degradation rates than their conventional counterparts, and the compostable plastic was resistant to degradation in the studied abiotic conditions. This study shows that degradation of plastics in real life conditions will vary depending in both, their composition and the environment.

Presentation of the FMI 5000 Project: Environmental changes: Fluvio-marine interactions over the last 5000yrs

NASA Astrophysics Data System (ADS)

Ramos-Pereira, Ana; Ramos, Catarina; Trindade, Jorge; Araújo-Gomes, João.; Rocha, Jorge; Granja, Helena; Gonçalves, Luís.; Monge-Soares, António; Martins, José

2010-05-01

Keywords: Estuaries, Environmental Changes, Holocene, GIS Modelling, Portugal FMI 5000 Project (between 2010 and 2012) aims to evaluate, in different estuarine environmental conditions, the balance between fluvial and marine influences, the responses to climatic events and the impact of land use changes. The temporal window chosen, contains different trends of the sea level, climatic fluctuations like the Bond events or humid episodes recorded in the Iberian Peninsula, as well as the increase of the human intervention in the landscape, particularly sensitive since the Bronze Age (circa 3500yr), imprinted in the filling-up of the alluvial plain estuaries. The Portuguese mainland mesotidal coast spreads out in two different environmental conditions: (i) the West coast exposed to the NW dominant waves, with a temperate oceanic climate and fluvial regimes and (ii) the Southern sheltered one, but open to the SW storms, with a Mediterranean climate and with occasional heavy fluvial discharges. This contrast along the coast creates a good field of research to achieve the aims of the project. To prosecute this goal, estuaries of medium drainage basins were selected as they have homogeneous climate, geologic and geomorphologic conditions, allowing to define accurately the hydroclimatic events that contribute to the infilling of the estuarine plains. The small changes are recorded not only in the textural properties of the sediments, already recognized in the sediments of the Tagus and Guadiana rivers and in the small estuaries of the Spanish southern coast but also in the micro fauna, pollens and non-pollen-palinomorphs allowing to define the environmental changes, both marine and fluvial. To achieve the Project goals we select three estuaries in different climatic and wave climate conditions, to develop four different kinds of research and methodologies: (i) To identify millenary evolution, several hand-operated gauge auger cores or vibracores will be carried out in the infilling sediments of the estuaries alluvial plains. The cored sediments will be treated to define the textural sedimentary changes, to identify the pollen and non-pollen-palinomorphs and the foraminifera content. The changes in the sedimentary record are fundamental in the flood episodes evaluation and the sequence of wet and dry period's establishment over the Middle and Upper Holocene. The identification of the pollen and non-pollen-palinomorphs will add information on the natural and human induced climatic and environmental conditions. The presence and the type of foraminifera content will set aside the marine incursion episodes and the environmental changes. Stable isotope ratios (δ13C) in muddy deposits will be used to identify sources of fine-sized organic matter (marine or terrestrial). (ii) To identify the secular evolution, the research of regional historical documents will focus not only on rainy/flooded episodes and droughts but also on the land use changes (e.g. deforestation, drying of marshes). (iii) To assess dating of the detected environmental change events, the sedimentation rates and the landscape evolution over the last 5000 yr, radiocarbon dating will be carried out. For the last century another approach will be used, based on radiometric data tools adequate to this temporal scale (210Pb) and compared with climatic and hydrological Portuguese network observational records. (iv) The correlation of the results provided by the three previous set of tasks would be performed and compared with Paleoclimatic Data Sets (e.g. NOAA) in order to evaluate how the global and regional climatic changes are reflected along the Western coast of the Iberian Peninsula during the last 5000yr. All data will be integrated in a GIS, allowing the reconstruction and modelling of paleolandscape, its evolution during the Middle and Upper Holocene and future tendencies in the global change scenario. Project financed by FCT - Fundação para a Ciência e Tcnologia, n°: PTDC/CTE-GIX/104035/2008

Effect of mosaic representation of vegetation in land surface schemes on simulated energy and carbon balances

NASA Astrophysics Data System (ADS)

Li, R.; Arora, V. K.

2011-06-01

Energy and carbon balance implications of representing vegetation using a composite or mosaic approach in a land surface scheme are investigated. In the composite approach the attributes of different plant functional types (PFTs) present in a grid cell are aggregated in some fashion for energy and water balance calculations. The resulting physical environmental conditions (including net radiation, soil moisture and soil temperature) are common to all PFTs and affect their ecosystem processes. In the mosaic approach energy and water balance calculations are performed separately for each PFT tile using its own vegetation attributes, so each PFT "sees" different physical environmental conditions and its carbon balance evolves somewhat differently from that in the composite approach. Simulations are performed at selected boreal, temperate and tropical locations to illustrate the differences caused by using the composite versus the mosaic approaches of representing vegetation. Differences in grid averaged primary energy fluxes are generally less than 5 % between the two approaches. Grid-averaged carbon fluxes and pool sizes can, however, differ by as much as 46 %. Simulation results suggest that differences in carbon balance between the two approaches arise primarily through differences in net radiation which directly affects net primary productivity, and thus leaf area index and vegetation biomass.

Relationships Between the Bulk-Skin Sea Surface Temperature Difference, Wind, and Net Air-Sea Heat Flux

NASA Technical Reports Server (NTRS)

Emery, William J.; Castro, Sandra L.; Lindstrom, Eric (Technical Monitor)

2002-01-01

The primary purpose of this project was to evaluate and improve models for the bulk-skin temperature difference to the point where they could accurately and reliably apply under a wide variety of environmental conditions. To accomplish this goal, work was conducted in three primary areas. These included production of an archive of available data sets containing measurements of the skin and bulk temperatures and associated environmental conditions, evaluation of existing skin layer models using the compiled data archive, and additional theoretical work on the development of an improved model using the data collected under diverse environmental conditions. In this work we set the basis for a new physical model of renewal type, and propose a parameterization for the temperature difference across the cool skin of the ocean in which the effects of thermal buoyancy, wind stress, and microscale breaking are all integrated by means of the appropriate renewal time scales. Ideally, we seek to obtain a model that will accurately apply under a wide variety of environmental conditions. A summary of the work in each of these areas is included in this report. A large amount of work was accomplished under the support of this grant. The grant supported the graduate studies of Sandra Castro and the preparation of her thesis which will be completed later this year. This work led to poster presentations at the 1999 American Geophysical Union Fall Meeting and 2000 IGARSS meeting. Additional work will be presented in a talk at this year's American Meteorological Society Air-Sea Interaction Meeting this May. The grant also supported Sandra Castro during a two week experiment aboard the R/P Flip (led by Dr. Andrew Jessup of the Applied Physics Laboratory) to help obtain additional shared data sets and to provide Sandra with a fundamental understanding of the physical processes needed in the models. In a related area, the funding also partially supported Dr. William Emery and Daniel Baldwin in the preparation of their publication "Accuracy of in situ sea surface temperatures used to calibrate infrared satellite measurements". The remainder of this report is drawn from these publications and presentations.

Effect of high environmental temperature on semen parameters among fertile men.

PubMed

Momen, M Nabil; Ananian, Fredrick B; Fahmy, Ibrahim M; Mostafa, Taymour

2010-04-01

To evaluate the effect of high environmental occupational temperature on semen parameters of fertile men. Prospective. Steel-casting plant. Ninety fertile workers exposed to a high temperature compared with 40 fertile workers working under ordinary conditions as control subjects. Measurement of scrotal temperature by invagination thermometry, air temperature, relative humidity by aspirated psychrometer, radiant heat by globe thermometer, air velocity by light vane anemometer, and semen analysis. Scrotal temperature and semen analysis. Nonsignificant difference was found between the two groups regarding their scrotal temperature. Also, nonsignificant differences were demonstrated regarding semen analysis parameters being in the normozoospermic range. Under high environmental temperature, semen parameters were within normozoospermic levels owing to body acclimatization mechanisms. Copyright 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Prenatal and Early Postnatal Environmental Enrichment Reduce Acute Cell Death and Prevent Neurodevelopment and Memory Impairments in Rats Submitted to Neonatal Hypoxia Ischemia.

PubMed

Durán-Carabali, L E; Arcego, D M; Odorcyk, F K; Reichert, L; Cordeiro, J L; Sanches, E F; Freitas, L D; Dalmaz, C; Pagnussat, A; Netto, C A

2018-05-01

Environmental enrichment (EE) is an experimental strategy to attenuate the negative effects of different neurological conditions including neonatal hypoxia ischemia encephalopathy (HIE). The aim of the present study was to investigate the influence of prenatal and early postnatal EE in animals submitted to neonatal HIE model at postnatal day (PND) 3. Wistar rats were housed in EE or standard conditions (SC) during pregnancy and lactation periods. Pups of both sexes were assigned to one of four experimental groups, considering the early environmental conditions and the injury: SC-Sham, SC-HIE, EE-sham, and EE-HIE. The offspring were euthanized at two different time points: 48 h after HIE for biochemical analyses or at PND 67 for histological analyses. Behavioral tests were performed at PND 7, 14, 21, and 60. Offspring from EE mothers had better performance in neurodevelopmental and spatial memory tests when compared to the SC groups. HIE animals showed a reduction of IGF-1 and VEGF in the parietal cortex, but no differences in BDNF and TrkB levels were found. EE-HIE animals showed reduction in cell death, lower astrocyte reactivity, and an increase in AKTp levels in the hippocampus and parietal cortex. In addition, the EE was also able to prevent the hippocampus tissue loss. Altogether, present findings point to the protective potential of the prenatal and early postnatal EE in attenuating molecular and histological damage, as well as the neurodevelopmental impairments and the cognitive deficit, caused by HIE insult at PND 3.

Is there evidence of adaptation to tidal flooding in saplings of baldcypress subjected to different salinity regimes?

USGS Publications Warehouse

Krauss, K.W.; Doyle, T.W.; Howard, R.J.

2009-01-01

Plant populations may adapt to environmental conditions over time by developing genetically based morphological or physiological characteristics. For tidal freshwater forested wetlands, we hypothesized that the conditions under which trees developed led to ecotypic difference in response of progeny to hydroperiod. Specifically, we looked for evidence of ecotypic adaptation for tidal flooding at different salinity regimes using growth and ecophysiological characteristics of two tidal and two non-tidal source collections of baldcypress (Taxodium distichum (L.) L.C. Rich) from the southeastern United States. Saplings were subjected to treatments of hydrology (permanent versus tidal flooding) and salinity (0 versus ???2 g l-1) for two and a half growing seasons in a greenhouse environment. Saplings from tidal sources maintained 21-41% lower overall growth and biomass accumulation than saplings from non-tidal sources, while saplings from non-tidal sources maintained 14-19% lower overall rates of net photosynthetic assimilation, leaf transpiration, and stomatal conductance than saplings from tidal sources. However, we found no evidence for growth or physiological enhancement of saplings from tidal sources to tide, or of saplings from non-tidal sources to no tide. All saplings growing under permanent flooding exhibited reduced growth and leaf gas exchange regardless of source, with little evidence for consistent salinity effects across hydroperiods. While we reject our original hypothesis, we suggest that adaptations of coastal baldcypress to broad (rather than narrow) environmental conditions may promote ecophysiological and growth enhancements under a range of global-change-induced stressors, perhaps reflecting a natural resilience to environmental change while precluding adaptations for specific flood regimes.

Defining indicators and standards for tourism impacts in protected areas: Cape Range National Park, Australia.

PubMed

Moore, Susan A; Polley, Amanda

2007-03-01

Visitors' perceptions of impacts and acceptable standards for environmental conditions can provide essential information for the sustainable management of tourist destinations, especially protected areas. To this end, visitor surveys were administered during the peak visitor season in Cape Range National Park, on the northwest coast of Western Australia and adjacent to the iconic Ningaloo Reef. The central focus was visitors' perceptions regarding environmental conditions and standards for potential indicators. Conditions considered of greatest importance in determining visitors' quality of experience included litter, inadequate disposal of human waste, presence of wildlife, levels of noise, and access to beach and ocean. Standards were determined, based on visitors' perceptions, for a range of site-specific and non-site-specific indicators, with standards for facilities (e.g., acceptable number of parking bays, signs) and for negative environmental impacts (e.g., levels of littering, erosion) sought. The proposed standards varied significantly between sites for the facilities indicators; however, there was no significant difference between sites for environmental impacts. For the facilities, the standards proposed by visitors were closely related to the existing situation, suggesting that they were satisfied with the status quo. These results are considered in the context of current research interest in the efficacy of visitor-derived standards as a basis for protected area management.

The increasing importance of environmental conditions in amyotrophic lateral sclerosis

NASA Astrophysics Data System (ADS)

Riancho, Javier; Bosque-Varela, Pilar; Perez-Pereda, Sara; Povedano, Mónica; de Munaín, Adolfo López; Santurtun, Ana

2018-04-01

Amyotrophic lateral sclerosis (ALS) is the most common neurodegenerative disease affecting motor neurons (MNs). Although a small percentage of ALS has a familial origin, the vast majority of cases are sporadic in which genetic factors and environment interact with each other leading to disease onset in genetically predisposed individuals. In the current model of the disease, each individual has a determined genetic load, some degree of cell degeneration related to age and several risky environmental exposures. In this scenario, MN degeneration would occur when the sum of these factors reach a certain threshold. To date, an extensive list of environmental factors has been associated to ALS, including different categories, such as exposure to heavy metals and other toxicants, cyanotoxins or infectious agents. In addition, in recent years, lifestyle and other demographic parameters are gaining relevance in the genesis of the disease. Among them, physical activity, nutrition, body mass index, cardiovascular risk factors, autoimmune diseases and cancer are some of the conditions which have been related to the disease. In this review, we will discuss the potential mechanisms of environmental conditions in motor neuron degeneration. Understanding the role of each one of these factors as well as their interactions appears as a crucial step in order to develop new preventive, diagnostic and therapeutic approaches for ALS patients.

Environmental stress speeds up DNA replication in Pseudomonas putida in chemostat cultivations.

PubMed

Lieder, Sarah; Jahn, Michael; Koepff, Joachim; Müller, Susann; Takors, Ralf

2016-01-01

Cellular response to different types of stress is the hallmark of the cell's strategy for survival. How organisms adjust their cell cycle dynamics to compensate for changes in environmental conditions is an important unanswered question in bacterial physiology. A cell using binary fission for reproduction passes through three stages during its cell cycle: a stage from cell birth to initiation of replication, a DNA replication phase and a period of cell division. We present a detailed analysis of durations of cell cycle phases, investigating their dynamics under environmental stress conditions. Applying continuous steady state cultivations (chemostats), the DNA content of a Pseudomonas putida KT2440 population was quantified with flow cytometry at distinct growth rates. Data-driven modeling revealed that under stress conditions, such as oxygen deprivation, solvent exposure and decreased iron availability, DNA replication was accelerated correlated to the severity of the imposed stress (up to 1.9-fold). Cells maintained constant growth rates by balancing the shortened replication phase with extended cell cycle phases before and after replication. Transcriptome data underpin the transcriptional upregulation of crucial genes of the replication machinery. Hence adaption of DNA replication speed appears to be an important strategy to withstand environmental stress. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Detection of Mycobacterium avium subspecies paratuberculosis in tie-stall dairy herds using a standardized environmental sampling technique and targeted pooled samples.

PubMed

Arango-Sabogal, Juan C; Côté, Geneviève; Paré, Julie; Labrecque, Olivia; Roy, Jean-Philippe; Buczinski, Sébastien; Doré, Elizabeth; Fairbrother, Julie H; Bissonnette, Nathalie; Wellemans, Vincent; Fecteau, Gilles

2016-07-01

Mycobacterium avium ssp. paratuberculosis (MAP) is the etiologic agent of Johne's disease, a chronic contagious enteritis of ruminants that causes major economic losses. Several studies, most involving large free-stall herds, have found environmental sampling to be a suitable method for detecting MAP-infected herds. In eastern Canada, where small tie-stall herds are predominant, certain conditions and management practices may influence the survival and transmission of MAP and recovery (isolation). Our objective was to estimate the performance of a standardized environmental and targeted pooled sampling technique for the detection of MAP-infected tie-stall dairy herds. Twenty-four farms (19 MAP-infected and 5 non-infected) were enrolled, but only 20 were visited twice in the same year, to collect 7 environmental samples and 2 pooled samples (sick cows and cows with poor body condition). Concurrent individual sampling of all adult cows in the herds was also carried out. Isolation of MAP was achieved using the MGIT Para TB culture media and the BACTEC 960 detection system. Overall, MAP was isolated in 7% of the environmental cultures. The sensitivity of the environmental culture was 44% [95% confidence interval (CI): 20% to 70%] when combining results from 2 different herd visits and 32% (95% CI: 13% to 57%) when results from only 1 random herd visit were used. The best sampling strategy was to combine samples from the manure pit, gutter, sick cows, and cows with poor body condition. The standardized environmental sampling technique and the targeted pooled samples presented in this study is an alternative sampling strategy to costly individual cultures for detecting MAP-infected tie-stall dairies. Repeated samplings may improve the detection of MAP-infected herds.

Differences on biological attributes of three populations of Meccus pallidipennis Stål (Hemiptera: Reduviidae).

PubMed

Martínez-Ibarra, José A; Nogueda-Torres, Benjamin; Salazar-Schettino, Paz M; Vences-Blanco, Mauro O; de la Torre-Álvarez, Felipe J; Montañez-Valdez, Oziel D

2014-03-01

Meccus pallidipennis is one of the most epidemiologically important vectors of Trypanosoma cruzi to reservoir hosts in nine states of Mexico. Triatomines occurring in distinct locations normally adapt to local conditions. The aim of this study was to examine the biological attributes of three populations of M. pallidipennis from areas with different environmental characteristics as a factor influencing the triatomine capacity for T. cruzi transmission. The values of biological parameters related to the life cycle, the number of blood meals to molt to next instar, fecundity and percentage of females after a biological cycle of three populations of M. pallidipennis were evaluated. A cohort of each of the three studied populations from different geographical areas of Mexico was maintained under similar laboratory conditions and then compared with each other. The life cycle was less than six months in all the studied cohorts, with differences among them. The number of blood meals to molt was lower for the cohort from Izϊcar de Matamoros. Laid eggs per day per female was lower for the cohort from Luvianos. In contrast, no important differences were recorded on the percentage of mortality, egg eclosion rate or percentages of obtained females. It was found that an important level of heterogeneity exist between the three studied populations of M. pallidipennis, apparently influenced by the remarkable differences on environmental conditions on the localities where the founders were initially collected, that emphasizes the necessity of studies on local populations of triatomines.

Lake System Development on the northern Tibetan Plateau during the last 12 ka

NASA Astrophysics Data System (ADS)

Ramisch, A. C.; Lockot, G.; Kasper, T.; Schulte, P.; Zhang, Y.; Daut, G.; Haberzettl, T.; Stauch, G.; Hartmann, K.; Zhu, L.; Lehmkuhl, F.; Maeusbacher, R.; Wuennemann, B.; Diekmann, B.

2013-12-01

Lake systems and their drainage basins provide valuable information of late Quaternary palaeo-environmental conditions on the Tibetan Plateau (TP). This information is often difficult to interpret because of a complex forcing-response mechanism of lake systems and their environment. Here we present an analysis of the endogenic mineral precipitation of Lake Heihai (northern TP) and its environmental constrains expressed by the exogenic mineral input. The mineralogical analysis of carbonate phases by means of X-ray diffraction revealed three distinct stages of carbonate precipitation: Aragonite (late Glacial), Monohydrocalcite (early to mid-Holocene) and Mg bearing Calcite (late Holocene). Each phase precipitates under steady state conditions of exogenic mineral input, as determined by a phase space analysis. This suggests a self-organized precipitation process driven by interactions of different ions. Hence, under steady environmental conditions carbonate precipitation is strongly dependent on the ionic compositions of the lake water and thus controlled by sources of the exogenic mineral input. To analyze the provenance of the exogenic mineral input, a Fuzzy C-Means (FCM) Clustering algorithm was performed on the minerogenic detrital fraction of the total mineral content of 57 surface reference samples. Three major sources can be distinguished: (a) glacially mediated, far distant transport originating from SE catchment (b) precipitation generated, close distant runoff originating from the SW catchment and (c) close distant transport of granite weathering products in the northern parts of the drainage basin. A change from the compositional dominance of (b) over (a) to (a) over (b) in lake sediments suggests a transition from rainfall to glacier dominated runoff production and hence drier climate conditions in the study area during the late Holocene. The environmentally controlled changes in the exogenic mineral input are compared to two different lake systems: Lake Donggi Cona (northern Tibetan Plateau) and Lake Nam Co (southern Tibetan Plateau). Major differences occur during two broad Holocene episodes: Until ~6 ka cal BP the differences reach their maximum with a peak around 9.5 cal ka BP. An intensification of the Indian Summer Monsoon (ISM) led to wetter conditions and an increased minerogenic input into Lake Nam Co. Subsequently, the aridification on the TP led to decreased minerogenic input in all three lakes especially since ~2 ka cal BP. Short term divergences from this trend are caused by dry spells on the northern TP. Their timing is quasi synchronous to Holocene Bond events, suggesting a teleconnection of northern TP climate to the circulation of the North Atlantic Ocean.

Plastic breeding system response to day length in the California wildflower Mimulus douglasii.

PubMed

Barnett, Laryssa L; Troth, Ashley; Willis, John H

2018-04-25

Angiosperms have evolved multiple breeding systems that allow reproductive success under varied conditions. Striking among these are cleistogamous breeding systems, where individuals can produce alternative flower types specialized for distinct mating strategies. Cleistogamy is thought to be environmentally-dependent, but little is known about environmental triggers. If production of alternate flowers is environmentally induced, populations may evolve locally adapted responses. Mimulus douglasii, exhibits a cleistogamous breeding system, and ranges across temperature and day-length gradients, providing an ideal system to investigate environmental parameters that control cleistogamy. We compared flowering responses across Mimulus douglasii population accessions that produce distinct outcrossing and self-pollinating flower morphs. Under controlled conditions, we determined time to flower, and number and type of flowers produced under different temperatures and day lengths. Temperature and day length both affect onset of flowering. Long days shift flower type from predominantly chasmogamous to cleistogamous. The strength of the response to day length varies across accessions whether temperature varies or is held constant. Cleistogamy is an environmentally sensitive polyphenism in Mimulus douglasii, allowing transition from one mating strategy to another. Longer days induce flowering and production of cleistogamous flowers. Shorter days induce chasmogamous flowers. Population origin has a small effect on response to environmental cues. © 2018 Botanical Society of America.

Vibrio parahaemolyticus Type VI Secretion System 1 Is Activated in Marine Conditions to Target Bacteria, and Is Differentially Regulated from System 2

PubMed Central

Salomon, Dor; Gonzalez, Herman; Updegraff, Barrett L.; Orth, Kim

2013-01-01

Vibrio parahaemolyticus is a marine bacterium that thrives in warm climates. It is a leading cause of gastroenteritis resulting from consumption of contaminated uncooked shellfish. This bacterium harbors two putative type VI secretion systems (T6SS). T6SSs are widespread protein secretion systems found in many Gram-negative bacteria, and are often tightly regulated. For many T6SSs studied to date, the conditions and cues, as well as the regulatory mechanisms that control T6SS activity are unknown. In this study, we characterized the environmental conditions and cues that activate both V. parahaemolyticus T6SSs, and identified regulatory mechanisms that control T6SS gene expression and activity. We monitored the expression and secretion of the signature T6SS secreted proteins Hcp1 and Hcp2, and found that both T6SSs are differentially regulated by quorum sensing and surface sensing. We also showed that T6SS1 and T6SS2 require different temperature and salinity conditions to be active. Interestingly, T6SS1, which is found predominantly in clinical isolates, was most active under warm marine-like conditions. Moreover, we found that T6SS1 has anti-bacterial activity under these conditions. In addition, we identified two transcription regulators in the T6SS1 gene cluster that regulate Hcp1 expression, but are not required for immunity against self-intoxication. Further examination of environmental isolates revealed a correlation between the presence of T6SS1 and virulence of V. parahaemolyticus against other bacteria, and we also showed that different V. parahaemolyticus isolates can outcompete each other. We propose that T6SS1 and T6SS2 play different roles in the V. parahaemolyticus lifestyles, and suggest a role for T6SS1 in enhancing environmental fitness of V. parahaemolyticus in marine environments when competing for a niche in the presence of other bacterial populations. PMID:23613791

Ecological sites: Organizational tool for outcome-based land management

USDA-ARS?s Scientific Manuscript database

Managing for sustained ecosystem services from rangelands involves complex interactions among soils, plant communities, topography and the prevailing environmental conditions across different land forms from local patches to entire landscapes. This complexity has contributed to prior difficulties in...

Social and physical environment alter cocaine conditioned place preference and dopaminergic markers in adolescent male rats.

PubMed

Zakharova, E; Miller, J; Unterwald, E; Wade, D; Izenwasser, S

2009-10-20

This study was done to determine whether social and environmental factors alter cocaine reward and proteins implicated in mediating drug reward in rats during early adolescence. On postnatal day (PND) 23, rats were housed under conditions where both social (number of rats per cage) and environmental (availability of toys) factors were manipulated. Socially isolated rats were housed alone impoverished with no toys (II) or enriched with toys (IE). Social rats were housed two rats/cage with no toys (SI2) or with toys (SE2), or three/cage with (SE3) or without (SI3) toys. On PND 43, cocaine conditioned place preference (CPP) sessions began with the post-test done on PND 47. Cocaine CPP was established in response to 5 or 10 mg/kg cocaine in II rats, and CPP was decreased with the addition of cage mates or toys. No CPP was seen to any dose in SI3 or SE3 rats. Enriched housing (SE3) increased dopamine transporter (DAT) protein in the nucleus accumbens compared to II. There also were differential effects of cocaine on tyrosine hydroxylase and DAT depending on housing, with both increased by cocaine in II but not SE3 rats. DARPP-32 was unchanged by housing or cocaine, while phospho-Thr(34)-DARPP-32 was increased by cocaine treatment across conditions. Thus, both social and environmental enrichment decrease cocaine CPP during adolescence and different housing alters proteins that regulate dopaminergic neurotransmission in a manner that may account for the observed differences in cocaine-induced reward.

Environmental tolerances of rare and common mangroves along light and salinity gradients.

PubMed

Dangremond, Emily M; Feller, Ilka C; Sousa, Wayne P

2015-12-01

Although mangroves possess a variety of morphological and physiological adaptations for life in a stressful habitat, interspecific differences in survival and growth under different environmental conditions can shape their local and geographic distributions. Soil salinity and light are known to affect mangrove performance, often in an interactive fashion. It has also been hypothesized that mangroves are intrinsically shade intolerant due to the high physiological cost of coping with saline flooded soils. To evaluate the relationship between stress tolerance and species distributions, we compared responses of seedlings of three widespread mangrove species and one narrow endemic mangrove species in a factorial array of light levels and soil salinities in an outdoor laboratory experiment. The more narrowly distributed species was expected to exhibit a lower tolerance of potentially stressful conditions. Two of the widespread species, Avicennia germinans and Lumnitzera racemosa, survived and grew well at low-medium salinity, regardless of light level, but performed poorly at high salinity, particularly under high light. The third widespread species, Rhizophora mangle, responded less to variation in light and salinity. However, at high salinity, its relative growth rate was low at every light level and none of these plants flushed leaves. As predicted, the rare species, Pelliciera rhizophorae, was the most sensitive to environmental stressors, suffering especially high mortality and reduced growth and quantum yield under the combined conditions of high light and medium-high salinity. That it only thrives under shaded conditions represents an important exception to the prevailing belief that halophytes are intrinsically constrained to be shade intolerant.

Strengthening environmental and educational nutrition programmes in worksite cafeterias and supermarkets in The Netherlands.

PubMed

Steenhuis, I H; Van Assema, P; Glanz, K

2001-03-01

The purpose of this study was to assess conditions for the adoption and continued implementation of different healthy nutrition programmes in worksite cafeterias and supermarkets, i.e. an educational programme and two environmental programmes (a food labelling programme and a food supply programme). Twenty semi-structured interviews were conducted with representatives of worksite cafeterias and supermarkets. Concepts of theories of diffusion were used as a framework for the study. Questions were formulated about the attributes of the innovation, and organizational and personal characteristics that might influence programme adoption and implementation. Results indicated that educational and environmental programmes in both worksite cafeterias and supermarkets should meet specific requirements regarding programme design, methods and materials in order to be adopted and implemented. Besides, some important implementation strategies of the educational and environmental programmes were identified. It is concluded that it seems feasible to conduct educational and environmental intervention programmes in worksite cafeterias and supermarkets, but that certain conditions for adoption and continued implementation have to be met. Based on the implications of this study, the development of an educational programme, a labelling programme and a food supply programme was completed.