Science.gov

Sample records for ecological responses investigations

  1. 100 Areas CERCLA ecological investigations

    SciTech Connect

    Landeen, D.S.; Sackschewsky, M.R.; Weiss, S.

    1993-09-01

    This document reports the results of the field terrestrial ecological investigations conducted by Westinghouse Hanford Company during fiscal years 1991 and 1992 at operable units 100-FR-3, 100-HR-3, 100-NR-2, 100-KR-4, and 100-BC-5. The tasks reported here are part of the Remedial Investigations conducted in support of the Comprehensive Environmental Response, compensation, and Liability Act of 1980 studies for the 100 Areas. These ecological investigations provide (1) a description of the flora and fauna associated with the 100 Areas operable units, emphasizing potential pathways for contaminants and species that have been given special status under existing state and/or federal laws, and (2) an evaluation of existing concentrations of heavy metals and radionuclides in biota associated with the 100 Areas operable units.

  2. Linking stressors and ecological responses

    USGS Publications Warehouse

    Gentile, J.H.; Solomon, K.R.; Butcher, J.B.; Harrass, M.; Landis, W.G.; Power, M.; Rattner, B.A.; Warren-Hicks, W.J.; Wenger, R.; Foran, Jeffery A.; Ferenc, Susan A.

    1999-01-01

    To characterize risk, it is necessary to quantify the linkages and interactions between chemical, physical and biological stressors and endpoints in the conceptual framework for ecological risk assessment (ERA). This can present challenges in a multiple stressor analysis, and it will not always be possible to develop a quantitative stressor-response profile. This review commences with a conceptual representation of the problem of developing a linkage analysis for multiple stressors and responses. The remainder of the review surveys a variety of mathematical and statistical methods (e.g., ranking methods, matrix models, multivariate dose-response for mixtures, indices, visualization, simulation modeling and decision-oriented methods) for accomplishing the linkage analysis for multiple stressors. Describing the relationships between multiple stressors and ecological effects are critical components of 'effects assessment' in the ecological risk assessment framework.

  3. Altering Their Ecological Niche: Investigating the Response of Avian Migrants to Changes in Vegetation Phenology at Northern Latitudes

    NASA Astrophysics Data System (ADS)

    Budde, M. E.; Ward, D. H.; Ely, C. R.; Handel, C. M.; Hupp, J. W.

    2009-12-01

    The impacts of global climate change are expected to be most severe at high northern latitudes. There is now strong evidence to support the hypothesis that such changes have had dramatic effects on the phenology of spring vegetative growth in these areas. One aspect of this change that has not been thoroughly investigated is how these changes vary across habitats and whether sub-Arctic and Arctic avifauna have adapted to shifts in plant phenology by modifying the timing of migration and nesting. A recent study showed that certain bird species have experienced population decline due to the varied timing of seasonal events and points to the fact that the degree of risk facing migratory birds is not well quantified. Plant phenology is especially sensitive to annual variation in temperature and precipitation and is a major determinant of plant species distribution, making it a good indicator of climate change effects. Migratory birds are considered one of the most vulnerable groups to the impacts of climate change because climate affects bird movement and distribution through species-specific physiological tolerances and changes in food and habitat resources. In this study we analyze the evidence for long-term plant phenology changes across different biomes of Alaska using satellite remote sensing techniques. We correlate this variability with ground-based measurements of avian migration and breeding. Specifically, we try to determine if the timing of spring green-up is synchronized across breeding areas or whether the process has become fractured across intervening biomes, potentially disrupting the timing of migration and breeding, putting species at risk. Using satellite-based time series of Normalized Difference Vegetation Index (NDVI) data, we create spatially explicit maps of seasonal vegetation metrics and correlate those with the timing and distribution of avian migrant populations. Preliminary investigation focused on the last 10 year period (2000-2009) and

  4. Ecological response to global climatic change

    USGS Publications Warehouse

    Malanson, G.P.; Butler, D.R.; Walsh, S. J.; Janelle, Donald G.; Warf, Barney; Hansen, Kathy

    2004-01-01

    Climate change and ecological change go hand in hand. Because we value our ecological environment, any change has the potential to be a problem. Geographers have been drawn to this challenge, and have been successful in addressing it, because the primary ecological response to climate changes in the past — the waxing and waning of the great ice sheets over the past 2 million years – was the changing geographic range of the biota. Plants and animals changed their location. Geographers have been deeply involved in documenting the changing biota of the past, and today we are called upon to help assess the possible responses to ongoing and future climatic change and, thus, their impacts. Assessing the potential responses is important for policy makers to judge the outcomes of action or inaction and also sets the stage for preparation for and mitigation of change.

  5. Developmental change in social responsibility during adolescence: An ecological perspective.

    PubMed

    Wray-Lake, Laura; Syvertsen, Amy K; Flanagan, Constance A

    2016-01-01

    Social responsibility can be defined as a set of prosocial values representing personal commitments to contribute to community and society. Little is known about developmental change-and predictors of that change-in social responsibility during adolescence. The present study used an accelerated longitudinal research design to investigate the developmental trajectory of social responsibility values and ecological assets across family, school, community, and peer settings that predict these values. Data come from a 3-year study of 3,683 U.S. adolescents enrolled in upper-level elementary, middle, and high schools in rural, semiurban, and urban communities. Social responsibility values significantly decreased from age 9 to 16 before leveling off in later adolescence. Family compassion messages and democratic climate, school solidarity, community connectedness, and trusted friendship, positively predicted within-person change in adolescents' social responsibility values. These findings held after accounting for other individual-level and demographic factors and provide support for the role of ecological assets in adolescents' social responsibility development. In addition, fair society beliefs and volunteer experience had positive between- and within-person associations with social responsibility values. The manuscript discusses theoretical and practical implications of the conclusion that declines in ecological assets may partly explain age-related declines in social responsibility values. (PsycINFO Database Record

  6. Improving Ecological Response Monitoring of Environmental Flows

    NASA Astrophysics Data System (ADS)

    King, Alison J.; Gawne, Ben; Beesley, Leah; Koehn, John D.; Nielsen, Daryl L.; Price, Amina

    2015-05-01

    Environmental flows are now an important restoration technique in flow-degraded rivers, and with the increasing public scrutiny of their effectiveness and value, the importance of undertaking scientifically robust monitoring is now even more critical. Many existing environmental flow monitoring programs have poorly defined objectives, nonjustified indicator choices, weak experimental designs, poor statistical strength, and often focus on outcomes from a single event. These negative attributes make them difficult to learn from. We provide practical recommendations that aim to improve the performance, scientific robustness, and defensibility of environmental flow monitoring programs. We draw on the literature and knowledge gained from working with stakeholders and managers to design, implement, and monitor a range of environmental flow types. We recommend that (1) environmental flow monitoring programs should be implemented within an adaptive management framework; (2) objectives of environmental flow programs should be well defined, attainable, and based on an agreed conceptual understanding of the system; (3) program and intervention targets should be attainable, measurable, and inform program objectives; (4) intervention monitoring programs should improve our understanding of flow-ecological responses and related conceptual models; (5) indicator selection should be based on conceptual models, objectives, and prioritization approaches; (6) appropriate monitoring designs and statistical tools should be used to measure and determine ecological response; (7) responses should be measured within timeframes that are relevant to the indicator(s); (8) watering events should be treated as replicates of a larger experiment; (9) environmental flow outcomes should be reported using a standard suite of metadata. Incorporating these attributes into future monitoring programs should ensure their outcomes are transferable and measured with high scientific credibility.

  7. Improving ecological response monitoring of environmental flows.

    PubMed

    King, Alison J; Gawne, Ben; Beesley, Leah; Koehn, John D; Nielsen, Daryl L; Price, Amina

    2015-05-01

    Environmental flows are now an important restoration technique in flow-degraded rivers, and with the increasing public scrutiny of their effectiveness and value, the importance of undertaking scientifically robust monitoring is now even more critical. Many existing environmental flow monitoring programs have poorly defined objectives, nonjustified indicator choices, weak experimental designs, poor statistical strength, and often focus on outcomes from a single event. These negative attributes make them difficult to learn from. We provide practical recommendations that aim to improve the performance, scientific robustness, and defensibility of environmental flow monitoring programs. We draw on the literature and knowledge gained from working with stakeholders and managers to design, implement, and monitor a range of environmental flow types. We recommend that (1) environmental flow monitoring programs should be implemented within an adaptive management framework; (2) objectives of environmental flow programs should be well defined, attainable, and based on an agreed conceptual understanding of the system; (3) program and intervention targets should be attainable, measurable, and inform program objectives; (4) intervention monitoring programs should improve our understanding of flow-ecological responses and related conceptual models; (5) indicator selection should be based on conceptual models, objectives, and prioritization approaches; (6) appropriate monitoring designs and statistical tools should be used to measure and determine ecological response; (7) responses should be measured within timeframes that are relevant to the indicator(s); (8) watering events should be treated as replicates of a larger experiment; (9) environmental flow outcomes should be reported using a standard suite of metadata. Incorporating these attributes into future monitoring programs should ensure their outcomes are transferable and measured with high scientific credibility.

  8. Investigations in Marine Chemistry: Tide Pool Ecology.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    Students investigated the salinity of tide pools at different levels in the intertidal zone. Data are analyzed collectively. Students graphed and discussed data. Included are suggestions for evaluation and further study. (Author)

  9. Fiscal year 1991 100 Areas CERCLA ecological investigations

    SciTech Connect

    Sackschewsky, M.R.; Landeen, D.S.

    1992-04-01

    This report discusses the status of the ecological investigations conducted by Westinghouse Hanford Company during Fiscal Year 1991. These ecological investigations provide a basic description of the flora and fauna that inhabit the operable units, emphasizing species that have been given special status under existing state and/or federal laws. The 1991 Westinghouse Hanford Company field investigations have concentrated on the following: (1) bird surveys, (2) mammal and insect surveys, (3) vegetation surveys, and (4) vegetation sampling. Work being conducted as part of the vegetation surveys includes a biological assessment of threatened and endangered plants, which is being prepared as a separate document. Similar ecological investigations will be conducted at 100- N, K, and F operable units in 1992.

  10. Isotopic, Ecological and Technological Investigations of the Land Snail Record

    ERIC Educational Resources Information Center

    Faber, Meredith L.

    2012-01-01

    In the ever-evolving landscape of the natural world, change is the only constant. Investigating how life accommodates that change can provide valuable insights into the biological, ecological and geological history of our planet. The fossil record is replete with examples of organisms which failed to survive in the wake of ongoing environmental…

  11. Ecological investigations at the Pantex Plant Site, 1992

    SciTech Connect

    Cushing, C.E.; Mazaika, R.R.; Phillips, R.C.

    1993-09-01

    In 1992, Pantex requested that Pacific Northwest Laboratory (PNL) conduct a series of ecological surveys to provide baseline information for designing detailed ecological studies on the various ecosystems present at the Pantex plant site near Amarillo, Texas. To this end, PNL scientist and technicians visited the site at different times to conduct investigations and collect samples: July 6--13: birds, small mammals, general habitat assessment; August 10--14: wetland vegetation, birds, small mammals, Playa invertebrates; and September 7--11: birds, small mammals. This report presents the results of these three surveys.

  12. Ecological genomics in Daphnia: stress responses and environmental sex determination.

    PubMed

    Eads, B D; Andrews, J; Colbourne, J K

    2008-02-01

    Ecological genomics is the study of adaptation of natural populations to their environment, and therefore seeks to link organism and population level processes through an understanding of genome organization and function. The planktonic microcrustacean Daphnia, which has long been an important system for ecology, is now being used as a genomic model as well. Here we review recent progress in selected areas of Daphnia genomics research. Production of parthenogenetic male offspring occurs through environmental cues, which clearly involves endocrine regulation and has also been studied as a toxicological response to juvenoid hormone analog insecticides. Recent progress has uncovered a putative juvenoid cis-response element, which together with microarray analysis will stimulate further research into nuclear hormone receptors and their associated transcriptional regulatory networks. Ecotoxicological studies indicate that mRNA profiling is a sensitive and specific research tool with promising applications in environmental monitoring and for uncovering conserved cellular processes. Rapid progress is expected to continue in these and other areas, as genomic tools for Daphnia become widely available to investigators.

  13. Ecological investigation of a hazardous waste site, Warner Robins, Georgia

    SciTech Connect

    Wade, M.; Billig, P.

    1993-05-01

    Landfill No. 4 and the sludge lagoon at Robins Air Force Base, Warner Robins, Georgia, were added to the United States Environmental Protection Agency (EPA) National Priorities List in 1987 because of highpotential for contaminant migration. Warner Robins is located approximately 90 miles southeast of Atlanta. In 1990 CH2M HILL conducted a Remedial Investigation at the base that recommended that further ecological assessment investigations be conducted (CH2M HILL 1990). The subject paper is the result of this recommendation. The ecological study was carried out by the Hazardous Waste Remedial Actions Program (HAZWRAP)Division of Martin Marietta Energy Systems, Inc., working jointly with its subcontractor CDM (CDM 1992a). The primary area of investigation (Zone 1) included the sludge lagoon, Landfill No. 4, the wetland area east of the landfill and west of Hannah Road (including two sewage treatment ponds), and the area between Hannah Road and Horse Creek (Fig. 1). The bottomland forest wetlands of Zone 1 extend from the landfill east to Horse Creek. Surface water and groundwater flow across Zone 1 is generally in an easterly direction toward Horse Creek. Horse Creek is a south-flowing tributary of the Ocmulgee River Floodplain. The objective of the study was to perform a quantitative analysis of ecological risk associated with the ecosystems present in Zone 1. This investigation was unique because the assessment was to be based upon many measurement endpoints resulting in both location-specific data and data that would assess the condition of the overall ecosystem. The study was segregated into five distinct field investigations: hydrology, surface water and sediment, aquatic biology, wetlands ecology, and wildlife biology.

  14. Aquatic ecological biochemical investigations in the Lake Baikal region

    SciTech Connect

    Timofeeva, S.S.; Kozhova, O.M.

    1986-07-01

    The authors maintain that at the current level of investigations a constructive solution of the problem of protecting aquatic ecosystems is possible only on the basis of a thorough study of biochemical mechanisms of the interaction of biota and pollutants. They believe that in the program of investigations in the Baikal region, with consideration of the easy vulnerability of the aquatic ecosystems, ecological biochemical investigations should occupy one of the leading places. The authors suggest a method for the screening of xenobiotics, consisting of xenobiotics; chemical investigations; biochemical investigations of the properties of xenobiotics, and toxicological investigations of xenobiotics. The differences in the elimination of xenobiotics are considerable due to the species and biochemical characteristics of hydrophytes and chemical structure of the investigated toxicants. The results obtained in experiments with cyanide compounds are of considerable interest, since cyanides, the strongest poisons of animals, prove to be little toxic for higher aquatic plants and algae.

  15. Ecological relevance of Sentinels' biomarker responses: a multi-level approach.

    PubMed

    Seabra Pereira, Camilo D; Abessa, Denis M S; Choueri, Rodrigo B; Almagro-Pastor, Victor; Cesar, Augusto; Maranho, Luciane A; Martín-Díaz, María Laura; Torres, Ronaldo J; Gusso-Choueri, Paloma K; Almeida, João E; Cortez, Fernando S; Mozeto, Antonio A; Silbiger, Helcy L N; Sousa, Eduinetty C P M; Del Valls, Tommas Angel; Bainy, Afonso C D

    2014-05-01

    In response to the need for more sensitive and rapid indicators of environmental quality, sublethal effects on the lowest levels of biological organization have been investigated. The ecological relevance of these responses assumes a prevailing role to assure effectiveness as indicator of ecological status. This study aimed to investigate the linkages between biomarker responses of caged bivalves and descriptive parameters of macrobenthic community structure. For this purpose a multi-level environmental assessment of marine and estuarine zones was performed in São Paulo coast, Brazil. Multivariate analysis was applied to identify linkages between biological responses and ecological indices, as well as to characterizing the studied stations. Individuals of the marine mussel Perna perna caged along Santos Bay showed signs of oxidative stress, lysosomal membrane destabilization, histological alterations and reduced embryonic development. The estuarine oyster Crassostrea rhizophorae caged along Santos Port Channel showed alterations on biotransformation enzymes and antioxidant system, DNA damage and lysosomal membrane destabilization. The benthic community analysis showed reduced richness and diversity in the same areas of the Santos bay and estuary where biomarker responses were altered. Our results revealed that xenobiotics are inducing physiological stress, which may lead to changes of the benthic community structure and deterioration of the ecological status over time. Integrating biomarker responses and ecological indexes improved certainty that alterations found at community level could be related to xenobiotic as stressors, which was very useful to improve the discriminatory power of the environmental assessment.

  16. Identifying microorganisms responsible for ecologically significant biogeochemical processes.

    PubMed

    Madsen, Eugene L

    2005-05-01

    Throughout evolutionary time, and each day in every habitat throughout the globe, microorganisms have been responsible for maintaining the biosphere. Despite the crucial part that they play in the cycling of nutrients in habitats such as soils, sediments and waters, only rarely have the microorganisms actually responsible for key processes been identified. Obstacles that have traditionally impeded fundamental microbial ecology inquiries are now yielding to technical advancements that have important parallels in medical microbiology. The pace of new discoveries that document ecological processes and their causative agents will no doubt accelerate in the near future, and might assist in ecosystem management.

  17. Shrinking body size as an ecological response to climate change

    NASA Astrophysics Data System (ADS)

    Sheridan, Jennifer A.; Bickford, David

    2011-11-01

    Determining how climate change will affect global ecology and ecosystem services is one of the next important frontiers in environmental science. Many species already exhibit smaller sizes as a result of climate change and many others are likely to shrink in response to continued climate change, following fundamental ecological and metabolic rules. This could negatively impact both crop plants and protein sources such as fish that are important for human nutrition. Furthermore, heterogeneity in response is likely to upset ecosystem balances. We discuss future research directions to better understand the trend and help ameliorate the trophic cascades and loss of biodiversity that will probably result from continued decreases in organism size.

  18. Ecological risk assessment guidance for preparation of remedial investigation/feasibility study work plans

    SciTech Connect

    Pentecost, E.D.; Vinikour, W.S.

    1993-08-01

    This guidance document (1) provides instructions on preparing the components of an ecological work plan to complement the overall site remedial assessment investigation/feasibility study (RI/FS) work plan and (2) directs the user on how to implement ecological tasks identified in the plan. Under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by the Superfired Amendments and Reauthorization Act of 1986 (SARA), an RI/FS work plan win have to be developed as part of the site-remediation scoping the process. Specific guidance on the RI/FS process and the preparation of work plans has been developed by the US Environmental Protection Agency (EPA 1988a). This document provides guidance to US Department of Energy (DOE) staff and contractor personnel for incorporation of ecological information into environmental remediation planning and decision making at CERCLA sites. An overview analysis of early ecological risk assessment methods (i.e., in the 1980s) at Superfund sites was conducted by the EPA (1989a). That review provided a perspective of attention given to ecological issues in some of the first RI/FS studies. By itself, that reference is of somewhat limited value; it does, however, establish a basis for comparison of past practices in ecological risk with current, more refined methods.

  19. Response Diversity and Resilience in Social-Ecological Systems

    PubMed Central

    Leslie, Paul; McCabe, J. Terrence

    2013-01-01

    Recent work in ecology suggests that the diversity of responses to environmental change among species contributing to the same ecosystem function can strongly influence ecosystem resilience. To render this important realization more useful for understanding coupled human-natural systems, we broaden the concept of response diversity to include heterogeneity in human decisions and action. Simply put, not all actors respond the same way to challenges, opportunities, and risks. The range, prevalence, and spatial and temporal distributions of different responses may be crucial to the resilience or the transformation of a social-ecological system, and thus have a bearing on human vulnerability and well-being in the face of environmental, socioeconomic, and political change. Response diversity can be seen at multiple scales (e.g., household, village, region) and response diversity at one scale may act synergistically with or contrary to the effects of diversity at another scale. Although considerable research on the sources of response diversity has been done, our argument is that the consequences of response diversity warrant closer attention. We illustrate this argument with examples drawn from our studies of two East African pastoral populations and discuss the relationship of response diversity to characteristics of social-ecological systems that can promote or diminish resilience. PMID:24855324

  20. Incorporating ecological risk assessment into remedial investigation/feasibility study work plans

    SciTech Connect

    Not Available

    1994-06-01

    This guidance document (1) provides instructions on preparing the components of an ecological work plan to complement the overall site remedial investigation/feasibility study (RI/FS) work plan and (2) directs the user on how to implement ecological tasks identified in the plan. Under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA), and RI/FS work plan will have to be developed as part of the site-remediation scoping process. Specific guidance on the RI/FS process and the preparation of work plans has been developed by the US Environmental Protection Agency (EPA 1988a). This document provides guidance to US Department of Energy (DOE) staff and contractor personnel for incorporation of ecological information into environmental remediation planning and decision making at CERCLA sites.

  1. Remedial investigation report for J-Field, Aberdeen Proving Ground, Maryland. Volume 3: Ecological risk assessment

    SciTech Connect

    Hlohowskyj, I.; Hayse, J.; Kuperman, R.; Van Lonkhuyzen, R.

    2000-02-25

    The Environmental Management Division of the U.S. Army Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation (RI) and feasibility study (FS) of the J-Field area at APG, pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. As part of that activity, Argonne National Laboratory (ANL) conducted an ecological risk assessment (ERA) of the J-Field site. This report presents the results of that assessment.

  2. Social Ecology and Group Cohesion in Pilot Whales and their Responses to Playback of Anthropogenic and Natural Sounds

    DTIC Science & Technology

    2014-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Social Ecology and Group Cohesion in Pilot Whales and their...N000141410410 LONG-TERM GOALS This project investigates the social ecology and cohesion of long-finned pilot whales as part of a broad multi...Social Ecology and Group Cohesion in Pilot Whales and their Responses to Playback of Anthropogenic and Natural Sounds 5a. CONTRACT NUMBER 5b. GRANT

  3. Designing the Perfect Plant: Activities to Investigate Plant Ecology

    ERIC Educational Resources Information Center

    Lehnhoff, Erik; Woolbaugh, Walt; Rew, Lisa

    2008-01-01

    Plant ecology is an important subject that often receives little attention in middle school, as more time during science classes is devoted to plant biology. Therefore, the authors have developed a series of activities, including a card game--Designing the Perfect Plant--to introduce student's to plant ecology and the ecological trade offs…

  4. Coccolithophore Response to CO2 Increase and Related Ecological Changes

    NASA Astrophysics Data System (ADS)

    Ziveri, P.

    2007-12-01

    Changes in ocean chemistry due to anthropogenic CO2 emissions affect marine life, nutrient cycles and biocalcification. Ocean acidification has been identified as a major consequence of rising atmospheric CO2 levels. This makes understanding the response of calcareous plankton, and other effects of global change, an urgent challenge. There have been controversial results from culture experiments and field observations, on the impact of CO2 increase on coccolithophore calcification and ecology. The objective of this presentation is to report the state-of-the-art on the impact of ocean acidification on coccolithophores and possible consequences on their biogeography and ecology. Results will also be reported from a workshop sponsored by the European Science Foundation (Euroclimate Program) and PAGES on Atmopheric CO2, ocean acidification and ecological changes in planktonic calcifying organisms. A wide range of experts contributed to that workshop, from the cellular and genetic to the ecological and global carbon cycle levels. Questions include how the predicted CO2 increase and acidification is likely to affect coccolithophores, what the possible secondary consequences may be, and what research is needed to allow robust predictions for the future.

  5. Biofilm Formation As a Response to Ecological Competition

    PubMed Central

    Oliveira, Nuno M.; Martinez-Garcia, Esteban; Xavier, Joao; Durham, William M.; Kolter, Roberto; Kim, Wook; Foster, Kevin R.

    2015-01-01

    Bacteria form dense surface-associated communities known as biofilms that are central to their persistence and how they affect us. Biofilm formation is commonly viewed as a cooperative enterprise, where strains and species work together for a common goal. Here we explore an alternative model: biofilm formation is a response to ecological competition. We co-cultured a diverse collection of natural isolates of the opportunistic pathogen Pseudomonas aeruginosa and studied the effect on biofilm formation. We show that strain mixing reliably increases biofilm formation compared to unmixed conditions. Importantly, strain mixing leads to strong competition: one strain dominates and largely excludes the other from the biofilm. Furthermore, we show that pyocins, narrow-spectrum antibiotics made by other P. aeruginosa strains, can stimulate biofilm formation by increasing the attachment of cells. Side-by-side comparisons using microfluidic assays suggest that the increase in biofilm occurs due to a general response to cellular damage: a comparable biofilm response occurs for pyocins that disrupt membranes as for commercial antibiotics that damage DNA, inhibit protein synthesis or transcription. Our data show that bacteria increase biofilm formation in response to ecological competition that is detected by antibiotic stress. This is inconsistent with the idea that sub-lethal concentrations of antibiotics are cooperative signals that coordinate microbial communities, as is often concluded. Instead, our work is consistent with competition sensing where low-levels of antibiotics are used to detect and respond to the competing genotypes that produce them. PMID:26158271

  6. Investigating Cooperative Behavior in Ecological Settings: An EEG Hyperscanning Study.

    PubMed

    Toppi, Jlenia; Borghini, Gianluca; Petti, Manuela; He, Eric J; De Giusti, Vittorio; He, Bin; Astolfi, Laura; Babiloni, Fabio

    2016-01-01

    The coordinated interactions between individuals are fundamental for the success of the activities in some professional categories. We reported on brain-to-brain cooperative interactions between civil pilots during a simulated flight. We demonstrated for the first time how the combination of neuroelectrical hyperscanning and intersubject connectivity could provide indicators sensitive to the humans' degree of synchronization under a highly demanding task performed in an ecological environment. Our results showed how intersubject connectivity was able to i) characterize the degree of cooperation between pilots in different phases of the flight, and ii) to highlight the role of specific brain macro areas in cooperative behavior. During the most cooperative flight phases pilots showed, in fact, dense patterns of interbrain connectivity, mainly linking frontal and parietal brain areas. On the contrary, the amount of interbrain connections went close to zero in the non-cooperative phase. The reliability of the interbrain connectivity patterns was verified by means of a baseline condition represented by formal couples, i.e. pilots paired offline for the connectivity analysis but not simultaneously recorded during the flight. Interbrain density was, in fact, significantly higher in real couples with respect to formal couples in the cooperative flight phases. All the achieved results demonstrated how the description of brain networks at the basis of cooperation could effectively benefit from a hyperscanning approach. Interbrain connectivity was, in fact, more informative in the investigation of cooperative behavior with respect to established EEG signal processing methodologies applied at a single subject level.

  7. Investigating Cooperative Behavior in Ecological Settings: An EEG Hyperscanning Study

    PubMed Central

    Petti, Manuela; He, Eric J.; De Giusti, Vittorio; He, Bin; Astolfi, Laura; Babiloni, Fabio

    2016-01-01

    The coordinated interactions between individuals are fundamental for the success of the activities in some professional categories. We reported on brain-to-brain cooperative interactions between civil pilots during a simulated flight. We demonstrated for the first time how the combination of neuroelectrical hyperscanning and intersubject connectivity could provide indicators sensitive to the humans’ degree of synchronization under a highly demanding task performed in an ecological environment. Our results showed how intersubject connectivity was able to i) characterize the degree of cooperation between pilots in different phases of the flight, and ii) to highlight the role of specific brain macro areas in cooperative behavior. During the most cooperative flight phases pilots showed, in fact, dense patterns of interbrain connectivity, mainly linking frontal and parietal brain areas. On the contrary, the amount of interbrain connections went close to zero in the non-cooperative phase. The reliability of the interbrain connectivity patterns was verified by means of a baseline condition represented by formal couples, i.e. pilots paired offline for the connectivity analysis but not simultaneously recorded during the flight. Interbrain density was, in fact, significantly higher in real couples with respect to formal couples in the cooperative flight phases. All the achieved results demonstrated how the description of brain networks at the basis of cooperation could effectively benefit from a hyperscanning approach. Interbrain connectivity was, in fact, more informative in the investigation of cooperative behavior with respect to established EEG signal processing methodologies applied at a single subject level. PMID:27124558

  8. Key ecological responses to nitrogen are altered by climate change

    NASA Astrophysics Data System (ADS)

    Greaver, T. L.; Clark, C. M.; Compton, J. E.; Vallano, D.; Talhelm, A. F.; Weaver, C. P.; Band, L. E.; Baron, J. S.; Davidson, E. A.; Tague, C. L.; Felker-Quinn, E.; Lynch, J. A.; Herrick, J. D.; Liu, L.; Goodale, C. L.; Novak, K. J.; Haeuber, R. A.

    2016-09-01

    Climate change and anthropogenic nitrogen deposition are both important ecological threats. Evaluating their cumulative effects provides a more holistic view of ecosystem vulnerability to human activities, which would better inform policy decisions aimed to protect the sustainability of ecosystems. Our knowledge of the cumulative effects of these stressors is growing, but we lack an integrated understanding. In this Review, we describe how climate change alters key processes in terrestrial and freshwater ecosystems related to nitrogen cycling and availability, and the response of ecosystems to nitrogen addition in terms of carbon cycling, acidification and biodiversity.

  9. Key ecological responses to nitrogen are altered by climate change

    USGS Publications Warehouse

    Greaver, T.L.; Clark, C.M.; Compton, J.E.; Vallano, D.; Talhelm, A. F.; Weaver, C.P.; Band, L.E.; Baron, J. S.; Davidson, E.A.; Tague, C.L.; Felker-Quinn, E.; Lynch, J.A.; Herrick, J.D.; Liu, L.; Goodale, C.L.; Novak, K. J.; Haeuber, R. A.

    2016-01-01

    Climate change and anthropogenic nitrogen deposition are both important ecological threats. Evaluating their cumulative effects provides a more holistic view of ecosystem vulnerability to human activities, which would better inform policy decisions aimed to protect the sustainability of ecosystems. Our knowledge of the cumulative effects of these stressors is growing, but we lack an integrated understanding. In this Review, we describe how climate change alters key processes in terrestrial and freshwater ecosystems related to nitrogen cycling and availability, and the response of ecosystems to nitrogen addition in terms of carbon cycling, acidification and biodiversity.

  10. Study on the Change of Landscape and Ecology of Sitou Forestland by Using Remotely Sensed and Ecological Investigation Data

    NASA Astrophysics Data System (ADS)

    Wei, Chiang; Lee, Chin-Ling; Liao, Huan-Chang; Tien, Pei-Ling; Huang, Yi-Ru; Tseng, Yu-San; Lai, Jing Rong; Shen, Chieh-Wen

    Due to natural disasters and anthropogenic disturbances in recent years, the landscape in Central Taiwan suffered certain kind of changes. In particular, landslides caused by earthquake and heavy rainfall, improper use and development in slope land enlarge and speed up the change of forest landscape. Few studies were focused on the interactions and relationships between change of ecosystem and landscape in Taiwan after natural disturbances in recent years. In this study, a pioneering research is accomplished by using Landscape Indices (LI) derived from FORMOSAT II Satellite imagery and GIS spatial coverage to describe the possible pattern of change between landscape and ecology. Located at the mountainous area in central Taiwan, ranging from 800 to 1,800 meter and comprising 2,349 hectares in size, Sitou Tract of the National Taiwan University Experimental Forest is selected as the study site. Four satellite images through 2004 to 2007 are used to compute LI, and analyzed with ecological investigation collected from five ground sites. The preliminary result shows that by using remotely sensed data and ground investigation, it is feasible to monitor and assess the relationship between change of landscape and ecology in forests. It indicates that the recovery and restoration of vegetation after the human and natural disturbances highly correlates with the value of NDVI (Normalized Differential Vegetation Index), the composition and diversity of birds and insects are highly correlated with the diversity of patches. The values of SHDI (Shannon Diversity Index), SIDI (Simpson Diversity Index), SHEI (Shannon Evenness Index) and SIEI (Simpson Evenness Index) show that the diversity of landscape is growing while the evenness of landscape remains stable between 2004 and 2007. The ecological investigation in 2006 and 2007 indicated that the species and relative abundance is decreasing. The proof for the obvious relationship between the change of ecology and landscape metrics

  11. Developmental Change in Social Responsibility during Adolescence: An Ecological Perspective

    ERIC Educational Resources Information Center

    Wray-Lake, Laura; Syvertsen, Amy K.; Flanagan, Constance A.

    2016-01-01

    Social responsibility can be defined as a set of prosocial values representing personal commitments to contribute to community and society. Little is known about developmental change--and predictors of that change--in social responsibility during adolescence. The present study used an accelerated longitudinal research design to investigate the…

  12. Phenotypic clines, energy balances and ecological responses to climate change.

    PubMed

    Buckley, Lauren B; Nufio, César R; Kingsolver, Joel G

    2014-01-01

    The Metabolic Theory of Ecology has renewed interest in using energetics to scale across levels of ecological organization. Can scaling from individual phenotypes to population dynamics provides insight into why species have shifted their phenologies, abundances and distributions idiosyncratically in response to recent climate change? We consider how the energetic implications of phenotypes may scale to understand population and species level responses to climate change using four focal grasshopper species along an elevation gradient in Colorado. We use a biophysical model to translate phenotypes and environmental conditions into estimates of body temperatures. We measure thermal tolerances and preferences and metabolic rates to assess rates of energy use and acquisition. Body mass declines along the elevation gradient for all species, but mass-specific metabolic rates increases only modestly. We find interspecific differences in both overall thermal tolerances and preferences and in the variation of these metrics along the elevation gradient. The more dispersive species exhibit significantly higher thermal tolerance and preference consistent with much of their range spanning hot, low elevation areas. When integrating these metrics to consider metabolic constraints, we find that energetic costs decrease along the elevation gradient due to decreasing body size and temperature. Opportunities for energy acquisition, as reflected by the proportion of time that falls within a grasshopper's thermal tolerance range, peak at mid elevations. We discuss methods for translating these energetic metrics into population dynamics. Quantifying energy balances and allocation offers a viable approach for predicting how populations will respond to climate change and the consequences for species composed of populations that may be locally adapted.

  13. [Physiological ecology responses of Scutellaria baicalensis to drought and rewatering].

    PubMed

    Zhang, Yong-Gang; Han, Mei; Jiang, Xue; Zhao, Sheng-Nan; Yang, Li-Min

    2013-11-01

    To study the physiological ecology responses of Scutellaria baicalensis to drought and rewatering of short period, we tested and analyzed photosynthesis and chlorophyll fluorescence parameters of S. baicalensis leaves processed by different ways of water treatment in drought and rewatering period, characteristic indexes of physiology and biochemistry of root SOD, POD, PAL, C4H, etc. and accumulation dynamic change of root baicalin and baicalein. The result showed that along with the worsening drought, P(n), T(r), G(s) and F(v)/F(m) of S. baicalensis declined in different water supply, and F(o) increased. The response of SOD and POD's activity in S. baicalensis root to drought in I and II was earlier than it in III. The response time and increase range of baicalin accumulation existed differences in different water supply, and the indexes regained after rewatering. Therefore, photosynthesis of S. baicalensis changed and it destroyed the antioxidant metabolism balance when soil water content decreased resulting from drought. The synergistic effect of defence mechanism launched by S. baicalensis, SOD, POD, PAL, C4H, baicalin and baicalein reduced active oxygen's damage to the cell.

  14. Molecular road ecology: exploring the potential of genetics for investigating transportation impacts on wildlife.

    PubMed

    Balkenhol, Niko; Waits, Lisette P

    2009-10-01

    Transportation infrastructures such as roads, railroads and canals can have major environmental impacts. Ecological road effects include the destruction and fragmentation of habitat, the interruption of ecological processes and increased erosion and pollution. Growing concern about these ecological road effects has led to the emergence of a new scientific discipline called road ecology. The goal of road ecology is to provide planners with scientific advice on how to avoid, minimize or mitigate negative environmental impacts of transportation. In this review, we explore the potential of molecular genetics to contribute to road ecology. First, we summarize general findings from road ecology and review studies that investigate road effects using genetic data. These studies generally focus only on barrier effects of roads on local genetic diversity and structure and only use a fraction of available molecular approaches. Thus, we propose additional molecular applications that can be used to evaluate road effects across multiple scales and dimensions of the biodiversity hierarchy. Finally, we make recommendations for future research questions and study designs that would advance molecular road ecology. Our review demonstrates that molecular approaches can substantially contribute to road ecology research and that interdisciplinary, long-term collaborations will be particularly important for realizing the full potential of molecular road ecology.

  15. Using historic aerial photography and paleohydrologic techniques to assess long-term ecological response to two Montana dam removals.

    PubMed

    Schmitz, Denine; Blank, Matt; Ammondt, Selita; Patten, Duncan T

    2009-07-01

    The restorative potential of dam removal on ecosystem function depends on the reversibility of dam effects and its operations. While dam removal is an established engineering practice, the need for an understanding of the ecological response remains. We used paleoflood hydrology, hydrologic modeling, and aerial photo interpretation to investigate the long-term ecologic responses to dam failure and breach. We investigated downstream geomorphic and vegetation responses to a dam failure (Pattengail Dam in 1927) and a controlled dam breach, which used natural sediment removal (Mystic Lake Dam in 1985). Our data showed vegetation responses indicative of channel and floodplain evolution at Pattengail. The size of the flood following the Pattengail dam failure initiated a series of channel adjustments and reworked over 19ha of floodplain downstream of the dam. In Mystic, we observed few flood stage indicators and a slight response in floodplain vegetation. We made several findings. (1) Dam removal effects on channel evolution and floodplain development depend on reach types and their responsiveness to flow regime change. (2) Ecologic response to dam removal depends on the sizes and timing of high flow events during and following removal. (3) Paleohydrology can be used to assess historic floods (>20 years). We see the utility of assessing the ecological responsiveness of a system to previous fluvial events or changes in flow regime. Informed about the character of a system based on its history, dam removal scientists can use these tools to set realistic restoration goals for removing a dam.

  16. INVESTIGATION OF RESPONSE DIFFERENCES BETWEEN ...

    EPA Pesticide Factsheets

    Total organic carbon (TOC) and dissolved organic carbon (DOC) have long been used to estimate the amount of natural organic matter (NOM) found in raw and finished drinking water. In recent years, computer automation and improved instrumental analysis technologies have created a variety of TOC instrument systems. However, the amount of organic carbon (OC) measured in a sample has been found to depend upon the way a specific TOC instrument treats the sample and the way the OC is calculated and reported. Specifically, relative instrument response differences for TOC/DOC, ranging between 15 to 62%, were documented when five different source waters were each analyzed by five different TOC instrument systems operated according to the manufacturer's specifications. Problems and possible solutions for minimizing these differences are discussed. Establish optimum performance criteria for current TOC technologies for application to Stage 2 D/DBP Rule.Develop a TOC and SUVA (incorporating DOC and UV254) method to be published in the Stage 2 D/DBP Rule that will meet requirements as stated in the Stage 1 D/DBP Rule (Revise Method 415.3,

  17. A Database and Meta-Analysis of Ecological Responses to Flow in the South Atlantic Region

    SciTech Connect

    McManamay, Ryan A; Orth, Dr. Donald J; Davis, Dr, Mary; Kauffman, John

    2013-01-01

    Generalized and quantitative relationships between flow and ecology are pivotal to developing environmental flow standards based on socially acceptable ecological conditions. Informing management at regional scales requires compiling sufficient hydrologic and ecological sources of information, identifying information gaps, and creating a framework for hypothesis development and testing. We compiled studies of empirical and theoretical relationships between flow and ecology in the South Atlantic region (SAR) of the United States to evaluate their utility for the development of environmental flow standards. Using database searches, internet searches, and agency contacts, we gathered 186 sources of information that provided a qualitative or quantitative relationship between flow and ecology within states encompassing the SAR. A total of 109 of the 186 sources had sufficient information to support quantitative analyses. Ecological responses to natural changes in flow magnitude, frequency, and duration were highly variable regardless of the direction and magnitude of changes in flow. In contrast, the majority of ecological responses to anthropogenic-induced flow alterations were negative. Fish consistently showed negative responses to anthropogenic flow alterations whereas other ecological groups showed somewhat variable responses (e.g. macroinvertebrates and riparian vegetation) and even positive responses (e.g. algae). Fish and organic matter had sufficient sample sizes to stratify natural flow-ecology relationships by specific flow categories (e.g. high flow, baseflows) or by region (e.g. coastal plain, uplands). After stratifying relationships, we found that significant correlations existed between changes in natural flow and ecological responses. In addition, a regression tree explained 57% of the variation in fish responses to anthropogenic and natural changes in flow. Because of some ambiguity in interpreting the directionality in ecological responses, we

  18. Associations between conservation practices and ecology: ecological responses of agricultural streams and lakes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Conservation Effects Assessment Program (CEAP) Watershed Assessment Study goals are to quantify the environmental benefits of conservation practices at the watershed scale. Currently, a critical knowledge gap exists in linking conservation practices and their ecological effects on aquatic ecosy...

  19. ROLE OF ANTHROPOGENIC AND ENVIRONMENTAL VARIABLE ON THE PHYSIOLOGICAL AND ECOLOGICAL RESPONSES OF OYSTERS IN SOUTHWEST FLORIDA ESTUARIES

    EPA Science Inventory

    The role of freshwater alterations and seasonal changes on the ecological and physiological responses of oysters were investigated in the Caloosahatchee River, Estero Bay and Faka-Union estuaries in SW Florida. Condition index, oyster density, and disease incidence of Perkinsus m...

  20. Ecology.

    ERIC Educational Resources Information Center

    National Audubon Society, New York, NY.

    This set of teaching aids consists of nine Audubon Nature Bulletins, providing teachers and students with informational reading on various ecological topics. The bulletins have these titles: Schoolyard Laboratories, Owls and Predators, The Forest Community, Life in Freshwater Marshes, Camouflage in the Animal World, Life in the Desert, The…

  1. Application of new physical chemical methods in soil ecological investigations.

    PubMed

    Motuzas, Algirdas; Vaisvalavicius, Rimantas; Prosycevas, Igoris

    2002-01-01

    The article discusses methodological investigations for the improvement and unification of soil testing in combination with the application of complex physico-chemical methods. An analytical procedure involving different extractions was used in order to determine the total and mobile amount of heavy metals (Cd, Cr, Pb, Ni, Cu, Zn, etc.) by atomic absorption spectrophotometry in soil and its fine-dispersive fraction (< 0.005 mm). The average samples (effected upon by background pollution) of Calcari Epihypogleyic Luvisol, (Lvg-p-w-cc, FAO-Unesco, 1998) has been taken from the rotation field of the experimental station of the Lithuanian University of Agriculture Subsequently, a fine-dispersive fraction was separated by a principle of peptization in distilled water. The investigation results obtained have shown a substantial dependence on the extractor used and the amount of fine-dispersive fraction in soil as well. It was found that the greatest reliability of the mobile heavy metal form is by using 1N CH3 COONH4 extractor and an HCl+HF mixture extractor for their total amount. Additionally, for the first time in Lithuania, the X-ray photoelectron spectroscopy (XPS) it has been applied for the interpretation of soil chemical composition.

  2. Responsibility-Based Youth Programs Evaluation: Investigating the Investigations.

    ERIC Educational Resources Information Center

    Hellison, Don; Walsh, David

    2002-01-01

    Reviews 26 studies that have investigated the impact of the personal-social responsibility model (RM), a physical activity program model, on underserved and/or at-risk youth since its inception. Results indicate that field research encompasses a wide range of approaches. However, the 26 studies enhance the theoretical and practical potential of RM…

  3. Ecology and Mary: An Ecological Theology of Mary as the New Eve in Response to the Church's Challenge for a Faith-Based Education in Ecological Responsibility

    ERIC Educational Resources Information Center

    Thurmond, Gloria J.

    2007-01-01

    The Church's interpretation of the current ecological crisis as a moral crisis is the catalyst for this essay, which proposes a newly constructed faith-based model for ecological dialogue and education. The exploration and reinterpretation of the traditional Church doctrine of the Virgin Mary as the new Eve provides a theme from which an…

  4. Response of Two Mytilids to a Heatwave: The Complex Interplay of Physiology, Behaviour and Ecological Interactions

    PubMed Central

    Gestoso, Ignacio; Lima, Fernando P.; Vázquez, Elsa; Comeau, Luc A.; Gomes, Filipa; Seabra, Rui

    2016-01-01

    Different combinations of behavioural and physiological responses may play a crucial role in the ecological success of species, notably in the context of biological invasions. The invasive mussel Xenostrobus securis has successfully colonised the inner part of the Galician Rias Baixas (NW Spain), where it co-occurs with the commercially-important mussel Mytilus galloprovincialis. This study investigated the effect of a heatwave on the physiological and behavioural responses in monospecific or mixed aggregations of these species. In a mesocosm experiment, mussels were exposed to simulated tidal cycles and similar temperature conditions to those experienced in the field during a heat-wave that occurred in the summer of 2013, when field robo-mussels registered temperatures up to 44.5°C at low tide. The overall responses to stress differed markedly between the two species. In monospecific aggregations M. galloprovincialis was more vulnerable than X. securis to heat exposure during emersion. However, in mixed aggregations, the presence of the invader was associated with lower mortality in M. galloprovincialis. The greater sensitivity of M. galloprovincialis to heat exposure was reflected in a higher mortality level, greater induction of Hsp70 protein and higher rates of respiration and gaping activity, which were accompanied by a lower heart rate (bradycardia). The findings show that the invader enhanced the physiological performance of M. galloprovincialis, highlighting the importance of species interactions in regulating responses to environmental stress. Understanding the complex interactions between ecological factors and physiological and behavioural responses of closely-related species is essential for predicting the impacts of invasions in the context of future climate change. PMID:27736896

  5. Response of Two Mytilids to a Heatwave: The Complex Interplay of Physiology, Behaviour and Ecological Interactions.

    PubMed

    Olabarria, Celia; Gestoso, Ignacio; Lima, Fernando P; Vázquez, Elsa; Comeau, Luc A; Gomes, Filipa; Seabra, Rui; Babarro, José M F

    2016-01-01

    Different combinations of behavioural and physiological responses may play a crucial role in the ecological success of species, notably in the context of biological invasions. The invasive mussel Xenostrobus securis has successfully colonised the inner part of the Galician Rias Baixas (NW Spain), where it co-occurs with the commercially-important mussel Mytilus galloprovincialis. This study investigated the effect of a heatwave on the physiological and behavioural responses in monospecific or mixed aggregations of these species. In a mesocosm experiment, mussels were exposed to simulated tidal cycles and similar temperature conditions to those experienced in the field during a heat-wave that occurred in the summer of 2013, when field robo-mussels registered temperatures up to 44.5°C at low tide. The overall responses to stress differed markedly between the two species. In monospecific aggregations M. galloprovincialis was more vulnerable than X. securis to heat exposure during emersion. However, in mixed aggregations, the presence of the invader was associated with lower mortality in M. galloprovincialis. The greater sensitivity of M. galloprovincialis to heat exposure was reflected in a higher mortality level, greater induction of Hsp70 protein and higher rates of respiration and gaping activity, which were accompanied by a lower heart rate (bradycardia). The findings show that the invader enhanced the physiological performance of M. galloprovincialis, highlighting the importance of species interactions in regulating responses to environmental stress. Understanding the complex interactions between ecological factors and physiological and behavioural responses of closely-related species is essential for predicting the impacts of invasions in the context of future climate change.

  6. The Socio-ecological Fit of Human Responses to Environmental Degradation: An Integrated Assessment Methodology

    NASA Astrophysics Data System (ADS)

    Briassoulis, Helen

    2015-12-01

    The scientific and policy interest in the human responses to environmental degradation usually focuses on responses sensu stricto and `best practices' that potentially abate degradation in affected areas. The transfer of individual, discrete instruments and `best practices' to different contexts is challenging, however, because socio-ecological systems are complex and environmental degradation is contextual and contingent. To sensibly assess the effectiveness of formal and informal interventions to combat environmental degradation, the paper proposes an integrative, non-reductionist analytic, the `response assemblage', for the study of `responses-in-context,' i.e., products of human decisions to utilize environmental resources to satisfy human needs in socio-ecological systems. Response assemblages are defined as geographically and historically unique, provisional, open, territorial wholes, complex compositions emerging from processes of assembling biophysical and human components, including responses sensu stricto, from affected focal and other socio-ecological systems, to serve human goals, one of which may be combatting environmental degradation. The degree of match among the components, called the socio- ecological fit of the response assemblage, indicates how effectively their contextual and contingent interactions maintain the socio-ecological resilience, promote sustainable development, and secure the continuous provision of ecosystem services in a focal socio-ecological system. The paper presents a conceptual approach to the analysis of the socio-ecological fit of response assemblages and details an integrated assessment methodology synthesizing the resilience, assemblage, and `problem of fit' literature. Lastly, it summarizes the novelty, value, and policy relevance of conceptualizing human responses as response assemblages and of the integrated assessment methodology, reconsiders `best practices' and suggests selected future research directions.

  7. Biological and ecological responses to carbon-based nanomaterials

    NASA Astrophysics Data System (ADS)

    Ratnikova, Tatsiana A.

    This dissertation examines the biological and ecological responses to carbon nanoparticles, a major class of nanomaterials which have been mass produced and extensively studied for their rich physical properties and commercial values. Chapter I of this dissertation offers a comprehensive review on the structures, properties, applications, and implications of carbon nanomaterials, especially related to the perspectives of biological and ecosystems. Given that there are many types of carbon nanomaterials available, this chapter is focused on three major types of carbon-based nanomaterials only, namely, fullerenes, single walled and multi-walled carbon nanotubes. On the whole organism level, specifically, Chapter II presents a first study on the fate of fullerenes and multiwalled carbon nanotubes in rice plants, which was facilitated by the self assembly of these nanomaterials with NOM. The aspects of fullerene uptake, translocation, biodistribution, and generational transfer in the plants were examined and quantified using bright field and electron microscopy, FT-Raman, and FTIR spectroscopy. The uptake and transport of fullerene in the plant vascular system were attributed to water transpiration, convection, capillary force, and the fullerene concentration gradient from the roots to the leaves of the plants. On the cellular level, Chapter III documents the differential uptake of hydrophilic C60(OH)20 vs. amphiphilic C70-NOM complex in Allium cepa plant cells and HT-29 colon carcinoma cells. This study was conducted using a plant cell viability assay, and complemented by bright field, fluorescence and electron microscopy imaging. In particular, C60(OH)20 and C70-NOM showed contrasting uptake in both the plant and mammalian cells, due to their significant differences in physicochemistry and the presence of an extra hydrophobic plant cell wall in the plant cells. Consequently, C60(OH)20 was found to induce toxicity in Allium cepa cells but not in HT-29 cells, while C70

  8. Integrating Quantitative Skills in Introductory Ecology: Investigations of Wild Bird Feeding Preferences

    ERIC Educational Resources Information Center

    Small, Christine J.; Newtoff, Kiersten N.

    2013-01-01

    Undergraduate biology education is undergoing dramatic changes, emphasizing student training in the "tools and practices" of science, particularly quantitative and problem-solving skills. We redesigned a freshman ecology lab to emphasize the importance of scientific inquiry and quantitative reasoning in biology. This multi-week investigation uses…

  9. Investigating Situational Willingness to Communicate within Second Language Classrooms from an Ecological Perspective

    ERIC Educational Resources Information Center

    Cao, Yiqian

    2011-01-01

    Previous research into willingness to communicate (WTC) in L2 has focused primarily on its trait dispositions that remain stable across contexts and its situated nature is under explored. Framed with an ecological perspective on second language learning, this multiple case study investigated the dynamic and situated nature of WTC in second…

  10. An Open-Ended Investigative Microbial Ecology Laboratory for Introductory Biology

    ERIC Educational Resources Information Center

    Jones-Held, Susan; Paoletti, Robert; Glick, David; Held, Michael E.

    2010-01-01

    In this article we describe a multi-week investigative laboratory in microbial ecology/diversity and nitrogen cycling that we have used in our introductory biology course. This module encourages active student involvement in experimental design, using the scientific literature and quantitative analysis of large data sets. Students analyze soil…

  11. Abrupt rise of new machine ecology beyond human response time

    PubMed Central

    Johnson, Neil; Zhao, Guannan; Hunsader, Eric; Qi, Hong; Johnson, Nicholas; Meng, Jing; Tivnan, Brian

    2013-01-01

    Society's techno-social systems are becoming ever faster and more computer-orientated. However, far from simply generating faster versions of existing behaviour, we show that this speed-up can generate a new behavioural regime as humans lose the ability to intervene in real time. Analyzing millisecond-scale data for the world's largest and most powerful techno-social system, the global financial market, we uncover an abrupt transition to a new all-machine phase characterized by large numbers of subsecond extreme events. The proliferation of these subsecond events shows an intriguing correlation with the onset of the system-wide financial collapse in 2008. Our findings are consistent with an emerging ecology of competitive machines featuring ‘crowds' of predatory algorithms, and highlight the need for a new scientific theory of subsecond financial phenomena. PMID:24022120

  12. Physiological response to etho-ecological stressors in male Alpine chamois: timescale matters!

    NASA Astrophysics Data System (ADS)

    Corlatti, Luca; Palme, Rupert; Lovari, Sandro

    2014-07-01

    From a life history perspective, glucocorticoids secreted by the neuroendocrine system, integrating different sources of stress through an adaptive feedback mechanism, may have important consequences on individual fitness. Although stress responses have been the object of several investigations, few studies have explored the role of proximate mechanisms responsible for the potential trade-offs between physiological stress and life history traits integrating social and environmental stressors. In 2011 and 2012, we collected data on faecal cortisol metabolites (FCM) in a marked male population of Alpine chamois, within the Gran Paradiso National Park (Italy). Using a model selection approach we analysed the effect of potential etho-ecological stressors such as age, social status (territorial vs. non-territorial males), minimum temperature, snow depth and precipitation on FCM variation. To correctly interpret environmentally and socially induced stress responses, we conducted model selections over multiple temporal scales defined a priori: year, cold months, spring, warm months, mating season. Over the year, FCM levels showed a negative relationship with minimum temperature, but altogether, climatic stressors had negligible effects on glucocorticoid secretion, possibly owing to good adaptations of chamois to severe weather conditions. Age was negatively related to FCM during the rut, possibly due to greater experience of older males in agonistic contests. Social status was an important determinant of FCM excretion: while both the `stress of subordination' and the `stress of domination' hypotheses received some support in spring and during the mating season, respectively, previous data suggest that only the latter may have detrimental fitness consequences on male chamois.

  13. Ecological and methodological drivers of species' distribution and phenology responses to climate change.

    PubMed

    Brown, Christopher J; O'Connor, Mary I; Poloczanska, Elvira S; Schoeman, David S; Buckley, Lauren B; Burrows, Michael T; Duarte, Carlos M; Halpern, Benjamin S; Pandolfi, John M; Parmesan, Camille; Richardson, Anthony J

    2016-04-01

    Climate change is shifting species' distribution and phenology. Ecological traits, such as mobility or reproductive mode, explain variation in observed rates of shift for some taxa. However, estimates of relationships between traits and climate responses could be influenced by how responses are measured. We compiled a global data set of 651 published marine species' responses to climate change, from 47 papers on distribution shifts and 32 papers on phenology change. We assessed the relative importance of two classes of predictors of the rate of change, ecological traits of the responding taxa and methodological approaches for quantifying biological responses. Methodological differences explained 22% of the variation in range shifts, more than the 7.8% of the variation explained by ecological traits. For phenology change, methodological approaches accounted for 4% of the variation in measurements, whereas 8% of the variation was explained by ecological traits. Our ability to predict responses from traits was hindered by poor representation of species from the tropics, where temperature isotherms are moving most rapidly. Thus, the mean rate of distribution change may be underestimated by this and other global syntheses. Our analyses indicate that methodological approaches should be explicitly considered when designing, analysing and comparing results among studies. To improve climate impact studies, we recommend that (1) reanalyses of existing time series state how the existing data sets may limit the inferences about possible climate responses; (2) qualitative comparisons of species' responses across different studies be limited to studies with similar methodological approaches; (3) meta-analyses of climate responses include methodological attributes as covariates; and (4) that new time series be designed to include the detection of early warnings of change or ecologically relevant change. Greater consideration of methodological attributes will improve the accuracy

  14. Ecological Impacts During the Deepwater Horizon Oil Spill Response

    EPA Science Inventory

    The Deepwater Horizon (DWH) oil spill was the largest environmental disaster and response effort in U.S. history, with nearly 800 million liters of crude oil spilled. Vast areas of the Gulf of Mexico were contaminated with oil, including deep-ocean communities and over 1,600 kilo...

  15. 21 CFR 812.100 - General responsibilities of investigators.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false General responsibilities of investigators. 812.100... (CONTINUED) MEDICAL DEVICES INVESTIGATIONAL DEVICE EXEMPTIONS Responsibilities of Investigators § 812.100 General responsibilities of investigators. An investigator is responsible for ensuring that...

  16. 21 CFR 312.60 - General responsibilities of investigators.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false General responsibilities of investigators. 312.60... (CONTINUED) DRUGS FOR HUMAN USE INVESTIGATIONAL NEW DRUG APPLICATION Responsibilities of Sponsors and Investigators § 312.60 General responsibilities of investigators. An investigator is responsible for...

  17. 21 CFR 812.100 - General responsibilities of investigators.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false General responsibilities of investigators. 812.100... (CONTINUED) MEDICAL DEVICES INVESTIGATIONAL DEVICE EXEMPTIONS Responsibilities of Investigators § 812.100 General responsibilities of investigators. An investigator is responsible for ensuring that...

  18. Investigating the environmental Kuznets curve hypothesis: the role of tourism and ecological footprint.

    PubMed

    Ozturk, Ilhan; Al-Mulali, Usama; Saboori, Behnaz

    2016-01-01

    The main objective of this study is to examine the environmental Kuznets curve (EKC) hypothesis by utilizing the ecological footprint as an environment indicator and GDP from tourism as the economic indicator. To achieve this goal, an environmental degradation model is established during the period of 1988-2008 for 144 countries. The results from the time series generalized method of moments (GMM) and the system panel GMM revealed that the number of countries that have a negative relationship between the ecological footprint and its determinants (GDP growth from tourism, energy consumption, trade openness, and urbanization) is more existent in the upper middle- and high-income countries. Moreover, the EKC hypothesis is more present in the upper middle- and high-income countries than the other income countries. From the outcome of this research, a number of policy recommendations were provided for the investigated countries.

  19. Ecological response to hydrological variability and catchment development: Insights from a shallow oxbow lake in Lower Mississippi Valley, Arkansas.

    PubMed

    Bhattacharya, Ruchi; Hausmann, Sonja; Hubeny, J Bradford; Gell, Peter; Black, Jessica L

    2016-11-01

    The ecological response of shallow oxbow lakes to variability in hydrology and catchment development in large river floodplain ecosystems (RFE) in Arkansas remains largely unknown. Investigating these responses will advance our understanding of ecological evolution of oxbow lakes in response to the major environmental drivers, which will establish baseline conditions required to develop effective management practices for RFE. In this pilot study, we examined the potential of using a dated surface sediment core from Adams Bayou, a floodplain lake located within the Cache-Lower White River Ramsar site in SE Arkansas. Stratigraphic records of diatoms and sediment geochemistry were used to ascertain variation in Adams Bayou's ecological condition. During 1968-2008, in response to hydrological and anthropogenic changes, Adams Bayou's diatom assemblages progressed from predominantly benthic (Gomphonema parvulum and Meridion circulare) to primarily planktonic assemblage (Aulacoseira granulata and Cyclotella meneghiniana), along with a decrease in magnetic susceptibility (k) and % silt. Statistical analyses reveled that during 1968-2000, higher hydrological connectivity and catchment alterations drove Adams Bayou's ecosystem. After 2000, lower hydrological connectivity and increase in cultivation were the major drivers. The potential impact of increasing air temperature was also noted. The shift in Adams Bayou from a connected, clear, mesotrophic state to a relatively isolated, turbid and nutrient enriched state is consistent with regime shift models and highlights its sensitivity to a combination of environmental stresses prevalent in the catchment. Although fluvial systems pose challenges in establishing clear chronologies, oxbow lake sediments can be a effective paleoecological archives. Our work provides clear evidence for the change in the ecological character of this wetland of international significance and flags the need for a wider assessment of water bodies

  20. ECOLOGICAL RESPONSES TO POLLUTION ABATEMENT: A FRAMEWORK FOR MEASUREMENT AND ASSESSMENT FOR COASTAL ECOSYSTEMS

    EPA Science Inventory

    Ecological Responses to Pollution Abatement: A Framework for Measurement and Assessment for Coastal Ecosystems (Abstract). To be presented at the 16th Biennial Conference of the Estuarine Research Foundation, ERF 2001: An Estuarine Odyssey, 4-8 November 2001, St. Pete Beach, FL. ...

  1. Measuring Early Childhood Teacher Candidates' Conceptualizations of a Culturally Responsive Classroom Ecology

    ERIC Educational Resources Information Center

    Flores, Belinda Bustos; Riojas-Cortez, Mari

    2009-01-01

    With the increase of Latino preschoolers, it is pressing that early childhood teachers are prepared to create a high quality environment in which all children can succeed. Using the frameworks of cultural responsiveness and classroom management, we developed the Early Childhood Ecology Scale (ECES) as an observational and reflective tool to…

  2. Synergistic Ecoclimate Teleconnections from Forest Loss in Different Regions Structure Global Ecological Responses

    PubMed Central

    Garcia, Elizabeth S.; Swann, Abigail L. S.; Villegas, Juan C.; Breshears, David D.; Law, Darin J.; Saleska, Scott R.; Stark, Scott C.

    2016-01-01

    Forest loss in hotspots around the world impacts not only local climate where loss occurs, but also influences climate and vegetation in remote parts of the globe through ecoclimate teleconnections. The magnitude and mechanism of remote impacts likely depends on the location and distribution of forest loss hotspots, but the nature of these dependencies has not been investigated. We use global climate model simulations to estimate the distribution of ecologically-relevant climate changes resulting from forest loss in two hotspot regions: western North America (wNA), which is experiencing accelerated dieoff, and the Amazon basin, which is subject to high rates of deforestation. The remote climatic and ecological net effects of simultaneous forest loss in both regions differed from the combined effects of loss from the two regions simulated separately, as evident in three impacted areas. Eastern South American Gross Primary Productivity (GPP) increased due to changes in seasonal rainfall associated with Amazon forest loss and changes in temperature related to wNA forest loss. Eurasia’s GPP declined with wNA forest loss due to cooling temperatures increasing soil ice volume. Southeastern North American productivity increased with simultaneous forest loss, but declined with only wNA forest loss due to changes in VPD. Our results illustrate the need for a new generation of local-to-global scale analyses to identify potential ecoclimate teleconnections, their underlying mechanisms, and most importantly, their synergistic interactions, to predict the responses to increasing forest loss under future land use change and climate change. PMID:27851740

  3. Key ecological responses to nitrogen are altered by climate ...

    EPA Pesticide Factsheets

    Here we review the effects of nitrogen and climate (e.g. temperature and precipitation) on four aspects of ecosystem structure and function including hydrologic-coupled nitrogen cycling, carbon cycling, acidification and biodiversity. Ecosystems are simultaneously exposed to multiple stressors; two dominant drivers threatening ecosystems are anthropogenic nitrogen loading and climate change. Evaluating the cumulative effects of these stressors provides a holistic view of ecosystem vulnerability, which would better inform policy decisions aimed to protect the sustainability of ecosystems. Our current knowledge of the cumulative effects of these stressors is growing, but limited. The goal of this paper is to synthesize the state of scientific knowledge on how ecosystems are affected by the interactions of meteorlogic/climatic factors (e.g., temperature and precipitation) and nitrogen addition. Understanding the interactions of meteorlogic/climatic factors and nitrogen will help to inform how current and projected variability may affect ecosystem response.

  4. Electrophysiology Meets Ecology: Investigating How Vision is Tuned to the Life Style of an Animal using Electroretinography

    PubMed Central

    Stowasser, Annette; Mohr, Sarah; Buschbeck, Elke; Vilinsky, Ilya

    2015-01-01

    Students learn best when projects are multidisciplinary, hands-on, and provide ample opportunity for self-driven investigation. We present a teaching unit that leads students to explore relationships between sensory function and ecology. Field studies, which are rare in neurobiology education, are combined with laboratory experiments that assess visual properties of insect eyes, using electroretinography (ERG). Comprised of nearly one million species, insects are a diverse group of animals, living in nearly all habitats and ecological niches. Each of these lifestyles puts different demands on their visual systems, and accordingly, insects display a wide array of eye organizations and specializations. Physiologically relevant differences can be measured using relatively simple extracellular electrophysiological methods that can be carried out with standard equipment, much of which is already in place in most physiology laboratories. The teaching unit takes advantage of the large pool of locally available species, some of which likely show specialized visual properties that can be measured by students. In the course of the experiments, students collect local insects or other arthropods of their choice, are guided to formulate hypotheses about how the visual system of “their” insects might be tuned to the lifestyle of the species, and use ERGs to investigate the insects’ visual response dynamics, and both chromatic and temporal properties of the visual system. Students are then guided to interpret their results in both a comparative physiological and ecological context. This set of experiments closely mirrors authentic research and has proven to be a popular, informative and highly engaging teaching tool. PMID:26240534

  5. Using the satellite-derived NDVI to assess ecological responses to environmental change.

    PubMed

    Pettorelli, Nathalie; Vik, Jon Olav; Mysterud, Atle; Gaillard, Jean-Michel; Tucker, Compton J; Stenseth, Nils Chr

    2005-09-01

    Assessing how environmental changes affect the distribution and dynamics of vegetation and animal populations is becoming increasingly important for terrestrial ecologists to enable better predictions of the effects of global warming, biodiversity reduction or habitat degradation. The ability to predict ecological responses has often been hampered by our rather limited understanding of trophic interactions. Indeed, it has proven difficult to discern direct and indirect effects of environmental change on animal populations owing to limited information about vegetation at large temporal and spatial scales. The rapidly increasing use of the Normalized Difference Vegetation Index (NDVI) in ecological studies has recently changed this situation. Here, we review the use of the NDVI in recent ecological studies and outline its possible key role in future research of environmental change in an ecosystem context.

  6. Ecological response to and management of increased flooding caused by climate change.

    PubMed

    Poff, N LeRoy

    2002-07-15

    River channels and their flood plains are among the most naturally dynamic ecosystems on earth, in large part due to periodic flooding. The components of a river's natural flood regime (magnitude, frequency, duration and timing of peak flows) interact to maintain great habitat heterogeneity and to promote high species diversity and ecosystem productivity. Flood regimes vary within and among rivers, depending on catchment size, geology and regional hydroclimatology. Geographic variation in contemporary flood regimes results in river-to-river variation in ecosystem structure, and therefore in potential river ecosystem response to increased future flooding. The greater the deviation in flood regime from contemporary or recent historical conditions, the greater the expected ecological alteration. Ecological response will also depend on how extensively humans have altered natural river dynamics through land-use practices. Examples of human-caused changes in flood regime (e.g. urbanization, agricultural practices) provide analogues to explore the ecological implications of region-specific climate change. In many settings where humans have severely modified rivers (e.g. through leveeing), more frequent larger floods will work to re-establish connections with severed flood-plain and riparian wetlands in human-dominated river valleys. Developing and implementing non-structural flood-management policies based on ecological principles can benefit river ecosystems, as well as human society.

  7. A summary of ecological investigations at the burial ground complex, Savannah River Site - 1994

    SciTech Connect

    Friday, G.P.; Hartman, G.D.; Mackey, H.E. Jr.; Riley, R.S.; Roach, J.L.; Specht, W.L.; Westbury, H.M.; Wike, L.D.

    1994-11-01

    This report summarizes the results of three ecological investigations that were conducted in 1994 at the Burial Ground Complex (BGC) at the Savannah River Site (SRS). The three topics of study included remote sensing, aquatic toxicity testing, and qualitative surveys of herpetofauna and small mammals. Interim reports from each investigation are included in the appendices (A, B, and C). The objectives of the remote sensing effort were to compile historical aerial photography of the BGC and to develop a land use/cover map of the complex using recent aerial imagery. The goal of the aquatic toxicity testing was to determine if surface waters were toxic to aquatic biota whereas the objectives of the vertebrate surveys were to identify the species diversity and relative abundances of amphibians, reptiles, and small mammals inhabiting the study area.

  8. Comparative Functional Responses Predict the Invasiveness and Ecological Impacts of Alien Herbivorous Snails

    PubMed Central

    Xu, Meng; Mu, Xidong; Dick, Jaimie T. A.; Fang, Miao; Gu, Dangen; Luo, Du; Zhang, Jiaen; Luo, Jianren; Hu, Yinchang

    2016-01-01

    Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in “100 of the World's Worst Invasive Alien Species”; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest “attack rates” a, shortest “handling times” h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach. PMID:26771658

  9. Comparative Functional Responses Predict the Invasiveness and Ecological Impacts of Alien Herbivorous Snails.

    PubMed

    Xu, Meng; Mu, Xidong; Dick, Jaimie T A; Fang, Miao; Gu, Dangen; Luo, Du; Zhang, Jiaen; Luo, Jianren; Hu, Yinchang

    2016-01-01

    Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs) of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in "100 of the World's Worst Invasive Alien Species"; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest "attack rates" a, shortest "handling times" h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach.

  10. Gene network architecture as a canvas for the interpretation of ecological genomics investigations.

    PubMed

    Landry, Christian R; Aubin-Horth, Nadia

    2010-12-01

    New technologies promise to revolutionize the field of molecular ecology. This technological progress comes with its own set of challenges. Among the most important ones is the analysis and interpretation of the data in a way that tells us about the molecular causes of the phenotype of interest and its consequences. In this issue, Whitehead et al. (2010) reveal part of the mechanistic basis of evolved pollution tolerance by studying the developmental and transcriptional response of tolerant and sensitive fish embryos to polychlorinated biphenyls (PCBs), a pollutant commonly found in coastal waters of the United States. By integrating their gene expression profiling data with phenotypic data on individuals along with what is known about pathways by which this pollutant acts in zebrafish and mammals, they are able to suggest detailed mechanisms that have evolved to allow a fish population to adapt to a very damaging pollutant and develop normally.

  11. Landscape ecological security response to land use change in the tidal flat reclamation zone, China.

    PubMed

    Zhang, Runsen; Pu, Lijie; Li, Jianguo; Zhang, Jing; Xu, Yan

    2016-01-01

    As coastal development becomes a national strategy in Eastern China, land use and landscape patterns have been affected by reclamation projects. In this study, taking Rudong County, China as a typical area, we analyzed land use change and its landscape ecological security responses in the tidal flat reclamation zone. The results show that land use change in the tidal flat reclamation zone is characterized by the replacement of natural tidal flat with agricultural and construction land, which has also led to a big change in landscape patterns. We built a landscape ecological security evaluation system, which consists of landscape interference degree and landscape fragile degree, and then calculated the landscape ecological security change in the tidal flat reclamation zone from 1990 to 2008 to depict the life cycle in tidal flat reclamation. Landscape ecological security exhibited a W-shaped periodicity, including the juvenile stage, growth stage, and maturation stage. Life-cycle analysis demonstrates that 37 years is required for the land use system to transform from a natural ecosystem to an artificial ecosystem in the tidal flat reclamation zone.

  12. A socio-ecological investigation of options to manage groundwater degradation in the Western Desert, Egypt.

    PubMed

    King, Caroline; Salem, Boshra

    2012-07-01

    Under increasing water scarcity, collective groundwater management is a global concern. This article presents an interdisciplinary analysis of this challenge drawing on a survey including 50 large and small farms and gardens in a village in an agricultural land reclamation area on the edge of the Western Desert of Egypt. Findings revealed that smallholders rely on a practice of shallow groundwater use, through which drainage water from adjacent irrigation areas is effectively recycled within the surface aquifer. Expanding agroindustrial activities in the surrounding area are socio-economically important, but by mining non-renewable water in the surrounding area, they set in motion a degradation process with social and ecological consequences for all users in the multi-layered aquifer system. Based on the findings of our investigation, we identify opportunities for local authorities to more systematically connect available environmental information sources and common pool resource management precedents, to counterbalance the degradation threat.

  13. Social Ecology and Group Cohesion in Pilot Whales and Their Responses to Playback of Anthropogenic and Natural Sounds

    DTIC Science & Technology

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Social ecology and group cohesion in pilot whales and their...N000141410410 LONG-TERM GOALS This project investigates the social ecology and cohesion of long-finned pilot whales as part of a broad multi...rules on individual and collective foraging success, to understand the ecological importance of different collective foraging strategies. At the

  14. Patterns of coral ecological immunology: variation in the responses of Caribbean corals to elevated temperature and a pathogen elicitor.

    PubMed

    Palmer, Caroline V; McGinty, Elizabeth S; Cummings, David J; Smith, Stephanie M; Bartels, Erich; Mydlarz, Laura D

    2011-12-15

    Disease epizootics are increasing with climatic shifts, yet within each system only a subset of species are identified as the most vulnerable. Understanding ecological immunology patterns as well as environmental influences on immune defenses will provide insight into the persistence of a functional system through adverse conditions. Amongst the most threatened ecosystems are coral reefs, with coral disease epizootics and thermal stress jeopardizing their survival. Immune defenses were investigated within three Caribbean corals, Montastraea faveolata, Stephanocoenia intersepta and Porites astreoides, which represent a range of disease and bleaching susceptibilities. Levels of several immune parameters were measured in response to elevated water temperature and the presence of a commercial pathogen-associated molecular pattern (PAMP) - lipopolysaccharide (LPS) - as an elicitor of the innate immune response. Immune parameters included prophenoloxidase (PPO) activity, melanin concentration, bactericidal activity, the antioxidants peroxidase and catalase, and fluorescent protein (FP) concentration. LPS induced an immune response in all three corals, although each species responded differently to the experimental treatments. For example, M. faveolata, a disease-susceptible species, experienced significant decreases in bactericidal activity and melanin concentration after exposure to LPS and elevated temperature alone. Porites astreoides, a disease-resistant species, showed increased levels of enzymatic antioxidants upon exposure to LPS independently and increased PPO activity in response to the combination of LPS and elevated water temperature. This study demonstrates the ability of reef-building corals to induce immune responses in the presence of PAMPs, indicating activation of PAMP receptors and the transduction of appropriate signals leading to immune effector responses. Furthermore, these data address the emerging field of ecological immunology by highlighting

  15. Phylogenetic Molecular Ecological Network of Soil Microbial Communities in Response to Elevated CO2

    PubMed Central

    Zhou, Jizhong; Deng, Ye; Luo, Feng; He, Zhili; Yang, Yunfeng

    2011-01-01

    ABSTRACT Understanding the interactions among different species and their responses to environmental changes, such as elevated atmospheric concentrations of CO2, is a central goal in ecology but is poorly understood in microbial ecology. Here we describe a novel random matrix theory (RMT)-based conceptual framework to discern phylogenetic molecular ecological networks using metagenomic sequencing data of 16S rRNA genes from grassland soil microbial communities, which were sampled from a long-term free-air CO2 enrichment experimental facility at the Cedar Creek Ecosystem Science Reserve in Minnesota. Our experimental results demonstrated that an RMT-based network approach is very useful in delineating phylogenetic molecular ecological networks of microbial communities based on high-throughput metagenomic sequencing data. The structure of the identified networks under ambient and elevated CO2 levels was substantially different in terms of overall network topology, network composition, node overlap, module preservation, module-based higher-order organization, topological roles of individual nodes, and network hubs, suggesting that the network interactions among different phylogenetic groups/populations were markedly changed. Also, the changes in network structure were significantly correlated with soil carbon and nitrogen contents, indicating the potential importance of network interactions in ecosystem functioning. In addition, based on network topology, microbial populations potentially most important to community structure and ecosystem functioning can be discerned. The novel approach described in this study is important not only for research on biodiversity, microbial ecology, and systems microbiology but also for microbial community studies in human health, global change, and environmental management. PMID:21791581

  16. Development of stressor-response models for an ecological risk assessment case study

    SciTech Connect

    Nacci, D.E.; Munns, W.R.; Cayula, S.; Serbst, J.; Johnston, R.K.; Walker, H.A.

    1994-12-31

    An estuarine ecological risk assessment for the Portsmouth Naval Shipyard (Kittery, ME) is being conducted following the US EPA`s Framework for Ecological Risk Assessment (ERA). As part of the Analysis phase of the ERA, laboratory studies were conducted to develop stressor-response models for lead, the primary contaminant of concern. Thirty-day exposures to adult sea urchins, Arbacia punctulata, occurred via food or suspended sediment. Exposure media were amended with lead sulfate to 10--100 or 100--300 times uncontaminated levels for the Feeding or Sediment Experiments, respectively. The sea urchin experimental model was selected because it permitted the measurement of biological endpoints with significance at the population level (e.g., adult survival and reproduction success), including those used in standard marine bioassays (i.e., fertilization and larval development). Feeding Experiment treatments produced few effects. Sediment Experiment treatments resulted in reductions in survival, growth and reproductive output of exposed adults and were directly toxic to early lifestages. However, in uncontaminated sea water, gametes from Sediment Experiment adults fertilized and completed larval development normally. Data from these experimental systems will be used to produce models relating lead exposure to specific biological responses and, ultimately, ecological risk.

  17. Coralline algae (Rhodophyta) in a changing world: integrating ecological, physiological, and geochemical responses to global change.

    PubMed

    McCoy, Sophie J; Kamenos, Nicholas A

    2015-02-01

    Coralline algae are globally distributed benthic primary producers that secrete calcium carbonate skeletons. In the context of ocean acidification, they have received much recent attention due to the potential vulnerability of their high-Mg calcite skeletons and their many important ecological roles. Herein, we summarize what is known about coralline algal ecology and physiology, providing context to understand their responses to global climate change. We review the impacts of these changes, including ocean acidification, rising temperatures, and pollution, on coralline algal growth and calcification. We also assess the ongoing use of coralline algae as marine climate proxies via calibration of skeletal morphology and geochemistry to environmental conditions. Finally, we indicate critical gaps in our understanding of coralline algal calcification and physiology and highlight key areas for future research. These include analytical areas that recently have become more accessible, such as resolving phylogenetic relationships at all taxonomic ranks, elucidating the genes regulating algal photosynthesis and calcification, and calibrating skeletal geochemical metrics, as well as research directions that are broadly applicable to global change ecology, such as the importance of community-scale and long-term experiments in stress response.

  18. Investigation of response time testing requirements

    SciTech Connect

    Swisher, V.I. ); Mayo, C.W. ); Weiss, J. )

    1991-05-01

    The purpose of the Response Time Testing (RTT) Program was to determine if requirements for RTT could be eliminated for specific pressure and differential pressure transmitters and switches. This program was initiated when experience and historical data from a significant number of nuclear power plants indicated that, while RTT is both resource and exposure intensive, an insignificant number of pressure sensor failures have been detected through this type of testing. Assessment of plant response time data and performance of Failure Modes and Effects Analysis (FMEA) on sensor hardware were the mechanisms used by the program to determine the redundancy of RTT in conjunction with other required periodic testing (e.g., calibrations, channel checks, surveillance tests). In general, the FMEA results indicated RTT is redundant to other periodic tests. Results of the program identified only two response time failure modes and two manufacturing/handling defects that may not concurrently affect sensor output. The two failure modes affect a limited number of sensor models. Appropriate testing has been identified in cases where response time degradation may not be coincident with significant sensor output change. 14 refs., 19 figs., 39 tabs.

  19. Ecological considerations for the use of dispersants in oil spill response

    USGS Publications Warehouse

    Lindstedt-Siva, J.; Albers, P.H.; Fucik, K.W.; Maynard, N.G.; Allen, Tom E.

    1984-01-01

    A multidisciplinary task force with membership from government agencies, academia, and industry is developing ecologically based guidelines for dispersant use in marine and estuarine environments. The guidelines are organized by habitat type (e.g., coral reefs, rocky shores, bird habitats) and consider dispersant use to protect the habitats from impact, to mitigate impacts, and to clean the habitats after a spill. Each guideline contains a description of the habitat type covered, recommendations for dispersant use, and a background section reviewing the relevant literature. The goal is to minimize the ecological impacts of oil spills. Aesthetic, socioeconomic, and political factors are not considered, although it is recognized that these are important concerns during spill response. Use of dispersants is considered along with other appropriate countermeasures and compared with the “no cleanup” alternative.

  20. Exploring the universal ecological responses to climate change in a univoltine butterfly.

    PubMed

    Fenberg, Phillip B; Self, Angela; Stewart, John R; Wilson, Rebecca J; Brooks, Stephen J

    2016-05-01

    Animals with distinct life stages are often exposed to different temperatures during each stage. Thus, how temperature affects these life stages should be considered for broadly understanding the ecological consequences of climate warming on such species. For example, temperature variation during particular life stages may affect respective change in body size, phenology and geographic range, which have been identified as the "universal" ecological responses to climate change. While each of these responses has been separately documented across a number of species, it is not known whether each response occurs together within a species. The influence of temperature during particular life stages may help explain each of these ecological responses to climate change. Our goal was to determine if monthly temperature variation during particular life stages of a butterfly species can predict respective changes in body size and phenology. We also refer to the literature to assess if temperature variability during the adult stage influences range change over time. Using historical museum collections paired with monthly temperature records, we show that changes in body size and phenology of the univoltine butterfly, Hesperia comma, are partly dependent upon temporal variation in summer temperatures during key stages of their life cycle. June temperatures, which are likely to affect growth rate of the final larval instar, are important for predicting adult body size (for males only; showing a positive relationship with temperature). July temperatures, which are likely to influence the pupal stage, are important for predicting the timing of adult emergence (showing a negative relationship with temperature). Previous studies show that August temperatures, which act on the adult stage, are linked to range change. Our study highlights the importance of considering temperature variation during each life stage over historic time-scales for understanding intraspecific response to

  1. Ecological interactions affecting population-level responses to chemical stress in Mesocyclops leuckarti.

    PubMed

    Kulkarni, Devdutt; Hommen, Udo; Schäffer, Andreas; Preuss, Thomas G

    2014-10-01

    Higher tiers of ecological risk assessment (ERA) consider population and community-level endpoints. At the population level, the phenomenon of density dependence is one of the most important ecological processes that influence population dynamics. In this study, we investigated how different mechanisms of density dependence would influence population-level ERA of the cyclopoid copepod Mesocyclops leuckarti under toxicant exposure. We used a combined approach of laboratory experiments and individual-based modelling. An individual-based model was developed for M. leuckarti to simulate population dynamics under triphenyltin exposure based on individual-level ecological and toxicological data from laboratory experiments. The study primarily aimed to-(1) determine which life-cycle processes, based on feeding strategies, are most significant in determining density dependence (2) explore how these mechanisms of density dependence affect extrapolation from individual-level effects to the population level under toxicant exposure. Model simulations showed that cannibalism of nauplii that were already stressed by TPT exposure contributed to synergistic effects of biotic and abiotic factors and led to a twofold stress being exerted on the nauplii, thereby resulting in a higher population vulnerability compared to the scenario without cannibalism. Our results suggest that in population-level risk assessment, it is easy to underestimate toxicity unless underlying ecological interactions including mechanisms of population-level density regulation are considered. This study is an example of how a combined approach of experiments and mechanistic modelling can lead to a thorough understanding of ecological processes in ecotoxicology and enable a more realistic ERA.

  2. Ecological versus case-control studies for testing a linear-no threshold dose-response relationship.

    PubMed

    Cohen, B L

    1990-09-01

    The two basic problems with ecological studies are (A) individuals studied are not necessarily the individuals who are at risk, and (B) they are very vulnerable to confounding factors. It is shown that where the study is designed to test a linear-no threshold dose-response theory, (A) does not apply. Where the ecological study deals with the average dose and response in a large number of US counties, the available data and computer capability for reducing effects of confounders are so powerful that (B) may be no more important for the ecological than for a case-control study. The migration problem is treated and found to be relatively unimportant.

  3. Application of microcosmic system for assessment of insecticide effects on biomarker responses in ecologically different earthworm species.

    PubMed

    Velki, Mirna; Hackenberger, Branimir K; Lončarić, Zeljka; Hackenberger, Davorka K

    2014-06-01

    Earthworms from different ecological categories--epigeic Eisenia andrei and Lumbricus rubellus, endogeic Octolasion lacteum and anecic Lumbricus terrestris--were exposed in a microcosmic system to three commonly used insecticides. The effects of the insecticides were evaluated by measuring the following molecular biomarkers-the activities of AChE, CES, CAT, GST and the concentration of GSH. The results showed that environmentally relevant doses of organophosphates dimethoate and pirimiphos-methyl significantly affected the measured biomarkers, whereas pyrethroid deltamethrin did not affect the earthworms at the recommended agricultural dose. Considering the ecological category of earthworms, the results were inhomogeneous and species-specific differences in the biomarker responses were recorded. Since the biomarker responses of the investigated earthworm species were different after exposure to organophosphates in a microcosm compared to the exposure via standardized toxicity tests, two types of species sensitivity should be distinguished-physiological and environmental sensitivity. In addition, the hormetic effect of organophosphates on AChE and CES activities was recorded. The detection of hormesis in a microcosm is of great importance for future environmental research and soil biomonitoring, since in a realistic environment pollutants usually occur at low concentrations that could cause a hormetic effect. The results demonstrate the importance of the application of microcosmic systems in the assessment of the effects of environmental pollutants and the necessity of taking into account the possible differences between physiological and environmental species sensitivity.

  4. Indigenous knowledge and long-term ecological change: detection, interpretation, and responses to changing ecological conditions in Pacific Island communities.

    PubMed

    Lauer, Matthew; Aswani, Shankar

    2010-05-01

    When local resource users detect, understand, and respond to environmental change they can more effectively manage environmental resources. This article assesses these abilities among artisanal fishers in Roviana Lagoon, Solomon Islands. In a comparison of two villages, it documents local resource users' abilities to monitor long-term ecological change occurring to seagrass meadows near their communities, their understandings of the drivers of change, and their conceptualizations of seagrass ecology. Local observations of ecological change are compared with historical aerial photography and IKONOS satellite images that show 56 years of actual changes in seagrass meadows from 1947 to 2003. Results suggest that villagers detect long-term changes in the spatial cover of rapidly expanding seagrass meadows. However, for seagrass meadows that showed no long-term expansion or contraction in spatial cover over one-third of respondents incorrectly assumed changes had occurred. Examples from a community-based management initiative designed around indigenous ecological knowledge and customary sea tenure governance show how local observations of ecological change shape marine resource use and practices which, in turn, can increase the management adaptability of indigenous or hybrid governance systems.

  5. Indigenous Knowledge and Long-term Ecological Change: Detection, Interpretation, and Responses to Changing Ecological Conditions in Pacific Island Communities

    PubMed Central

    Aswani, Shankar

    2010-01-01

    When local resource users detect, understand, and respond to environmental change they can more effectively manage environmental resources. This article assesses these abilities among artisanal fishers in Roviana Lagoon, Solomon Islands. In a comparison of two villages, it documents local resource users’ abilities to monitor long-term ecological change occurring to seagrass meadows near their communities, their understandings of the drivers of change, and their conceptualizations of seagrass ecology. Local observations of ecological change are compared with historical aerial photography and IKONOS satellite images that show 56 years of actual changes in seagrass meadows from 1947 to 2003. Results suggest that villagers detect long-term changes in the spatial cover of rapidly expanding seagrass meadows. However, for seagrass meadows that showed no long-term expansion or contraction in spatial cover over one-third of respondents incorrectly assumed changes had occurred. Examples from a community-based management initiative designed around indigenous ecological knowledge and customary sea tenure governance show how local observations of ecological change shape marine resource use and practices which, in turn, can increase the management adaptability of indigenous or hybrid governance systems. PMID:20336296

  6. Understanding multiple ecological responses to anthropogenic disturbance: rivers and potential flow regime change.

    PubMed

    Leigh, Catherine; Stewart-Koster, Ben; Sheldon, Fran; Burford, Michele A

    2012-01-01

    Human-induced alteration of the natural flow regime is a major threat to freshwater ecosystems and biodiversity. The effects of hydrological alteration on the structural and functional attributes of riverine communities are expected to be multiple and complex, and they may not be described easily by a single model. Based on existing knowledge of key hydrological and ecological attributes, we explored potential effects of a flow-regulation scenario on macroinvertebrate assemblage composition and diversity in two river systems in Australia's relatively undeveloped wet-dry tropics. We used a single Bayesian belief network (BBN) to model potential changes in multiple assemblage attributes within each river type during dry and wet seasons given two flow scenarios: the current, near-natural flow condition, and flow regulation. We then used multidimensional scaling (MDS) ordination to visually summarize and compare the most probable attributes of assemblages and their environment under the different scenarios. The flow-regulation scenario provided less certainty in the ecological responses of one river type during the dry season, which reduced the ability to make predictions from the BBN outputs directly. However, visualizing the BBN results in an ordination highlighted similarities and differences between the scenarios that may have been otherwise difficult to ascertain. In particular, the MDS showed that flow regulation would reduce the seasonal differentiation in hydrology and assemblage characteristics that is expected under the current low level of development. Our approach may have wider application in understanding ecosystem responses to different river management practices and should be transferred easily to other ecosystems or biotic assemblages to provide researchers, managers, and decision makers an enhanced understanding of ecological responses to potential anthropogenic disturbance.

  7. Neural responses to sounds presented on and off the beat of ecologically valid music

    PubMed Central

    Tierney, Adam; Kraus, Nina

    2013-01-01

    The tracking of rhythmic structure is a vital component of speech and music perception. It is known that sequences of identical sounds can give rise to the percept of alternating strong and weak sounds, and that this percept is linked to enhanced cortical and oscillatory responses. The neural correlates of the perception of rhythm elicited by ecologically valid, complex stimuli, however, remain unexplored. Here we report the effects of a stimulus' alignment with the beat on the brain's processing of sound. Human subjects listened to short popular music pieces while simultaneously hearing a target sound. Cortical and brainstem electrophysiological onset responses to the sound were enhanced when it was presented on the beat of the music, as opposed to shifted away from it. Moreover, the size of the effect of alignment with the beat on the cortical response correlated strongly with the ability to tap to a beat, suggesting that the ability to synchronize to the beat of simple isochronous stimuli and the ability to track the beat of complex, ecologically valid stimuli may rely on overlapping neural resources. These results suggest that the perception of musical rhythm may have robust effects on processing throughout the auditory system. PMID:23717268

  8. An ecological response model for the Cache la Poudre River through Fort Collins

    USGS Publications Warehouse

    Shanahan, Jennifer; Baker, Daniel; Bledsoe, Brian P.; Poff, LeRoy; Merritt, David M.; Bestgen, Kevin R.; Auble, Gregor T.; Kondratieff, Boris C.; Stokes, John; Lorie, Mark; Sanderson, John

    2014-01-01

    The ERM was designed to represent the multi-dimensional ecological character of the contemporary urban Poudre River. It provides a scientific foundation that can serve as a decision support tool and foster a more informed community discussion about the future of the river as it provides a better understanding of the likely response of the Poudre River ecosystem to environmental flow management and other stewardship activities. In particular, model results can assist managers in developing specific management actions to achieve desirable goals for key indicators of river health.

  9. Investigating General and Specific Links from Adolescents' Perceptions of Ecological Assets to Their Civic Actions

    ERIC Educational Resources Information Center

    Wray-Lake, Laura; Sloper, Michelle A.

    2016-01-01

    Civic engagement is an important marker of thriving among adolescents, and more research is needed that clarifies the ecological assets (positive supports across settings) that foster youth civic engagement. Simultaneously modeling associations between multiple ecological assets and civic behaviors can provide a nuanced view of the way…

  10. Using Ecological Asset Mapping to Investigate Pre-Service Teachers' Cultural Assets

    ERIC Educational Resources Information Center

    Borrero, Noah; Yeh, Christine

    2016-01-01

    We examined the impact of a pedagogical strategy, ecological asset mapping, on 19 pre-service teachers' self-exploration, development of respect for others, and critical examination of social injustice. Data were analyzed from participants' ecological asset maps and essays describing the experience of completing and sharing the maps. The analysis…

  11. Adaptive Patterns of Stress Responsivity: A Preliminary Investigation

    PubMed Central

    Del Giudice, Marco; Hinnant, J. Benjamin; Ellis, Bruce J.; El-Sheikh, Mona

    2014-01-01

    The adaptive calibration model (ACM) is an evolutionary–developmental theory of individual differences in stress responsivity. In this article, we tested some key predictions of the ACM in a middle childhood sample (N = 256). Measures of autonomic nervous system activity across the sympathetic and parasympathetic branches validated the 4-pattern taxonomy of the ACM via finite mixture modeling. Moreover, the 4 patterns of responsivity showed the predicted associations with family stress levels but no association with measures of ecological stress. Our hypotheses concerning sex differences in responsivity were only partly confirmed. This preliminary study provides initial support for the key predictions of the ACM and highlights some of the methodological challenges that will need to be considered in future research on this topic. PMID:22148947

  12. Ecological limit functions relating fish community response to hydrologic departures of the ecological flow regime in the Tennessee River basin, United States

    USGS Publications Warehouse

    Knight, Rodney R.; Murphy, Jennifer C.; Wolfe, William J.; Saylor, Charles F.; Wales, Amy K.

    2014-01-01

    Ecological limit functions relating streamflow and aquatic ecosystems remain elusive despite decades of research. We investigated functional relationships between species richness and changes in streamflow characteristics at 662 fish sampling sites in the Tennessee River basin. Our approach included the following: (1) a brief summary of relevant literature on functional relations between fish and streamflow, (2) the development of ecological limit functions that describe the strongest discernible relationships between fish species richness and streamflow characteristics, (3) the evaluation of proposed definitions of hydrologic reference conditions, and (4) an investigation of the internal structures of wedge-shaped distributions underlying ecological limit functions.Twenty-one ecological limit functions were developed across three ecoregions that relate the species richness of 11 fish groups and departures from hydrologic reference conditions using multivariate and quantile regression methods. Each negatively sloped function is described using up to four streamflow characteristics expressed in terms of cumulative departure from hydrologic reference conditions. Negative slopes indicate increased departure results in decreased species richness.Sites with the highest measured fish species richness generally had near-reference hydrologic conditions for a given ecoregion. Hydrology did not generally differ between sites with the highest and lowest fish species richness, indicating that other environmental factors likely limit species richness at sites with reference hydrology.Use of ecological limit functions to make decisions regarding proposed hydrologic regime changes, although commonly presented as a management tool, is not as straightforward or informative as often assumed. We contend that statistical evaluation of the internal wedge structure below limit functions may provide a probabilistic understanding of how aquatic ecology is influenced by altered hydrology

  13. An initial investigation into the ecology of culturable aerobic postmortem bacteria.

    PubMed

    Chun, Lauren P; Miguel, Marcus J; Junkins, Emily N; Forbes, Shari L; Carter, David O

    2015-12-01

    Postmortem microorganisms are increasingly recognized for their potential to serve as physical evidence. Yet, we still understand little about the ecology of postmortem microbes, particularly those associated with the skin and larval masses. We conducted an experiment to characterize microbiological and chemical properties of decomposing swine (Sus scrofa domesticus) carcasses on the island of Oahu, Hawaii, USA, during June 2013. Bacteria were collected from the head, limb, and larval mass during the initial 145h of decomposition. We also measured the pH, temperature, and oxidation-reduction potential of larval masses in situ. Bacteria were cultured aerobically on Standard Nutrient Agar at 22°C and identified using protein or genetic signals. Carcass decomposition followed a typical sigmoidal pattern and associated bacterial communities differed by sampling location and time since death, although all communities were dominated by phyla Actinobacteria, Firmicutes, and Proteobacteria. Larval masses were reducing environments (~-200mV) of neutral pH (6.5-7.5) and high temperature (35°C-40°C). We recommend that culturable postmortem and larval mass microbiology and chemistry be investigated in more detail, as it has potential to complement culture-independent studies and serve as a rapid estimate of PMI.

  14. An ecological momentary assessment investigation of complex and conflicting emotions in youth with borderline personality disorder.

    PubMed

    Andrewes, Holly E; Hulbert, Carol; Cotton, Susan M; Betts, Jennifer; Chanen, Andrew M

    2017-02-27

    Non-suicidal self-injury (NSSI) is a prevalent behaviour among people with borderline personality disorder (BPD) but many aspects of the emotional changes that trigger and maintain this behaviour are unknown. This study examines the relationships between NSSI and the number of negative ('negative complex') and opposing valence ('conflicting') emotions. One hundred and seven youth (aged 15-25 years) with first-presentation BPD were assessed using a combination of self-report and ecological momentary assessment to investigate trait levels of emotional acceptance and in vivo changes in the number of negative complex and conflicting emotions before and after self-injurious thoughts and behaviours. Multilevel modelling revealed that changes in the number of negative complex emotions mirrored distress levels before and after self-injurious thoughts and behaviours, approximating a quadratic curve. Increases in the number of negative complex emotions reported prior to self-injurious thoughts and behaviours were associated with lower acceptance of negative emotions. These findings indicate that the number of negative emotions experienced contributes to distress prior to engagement in NSSI. The relationship between non-acceptance of negative emotions and negative complex emotions prior to NSSI suggests that improved emotional awareness and acceptance should be a focus for early interventions aimed at reducing self-injury.

  15. Nanoindentation of lemur enamel: an ecological investigation of mechanical property variations within and between sympatric species.

    PubMed

    Campbell, Sara E; Cuozzo, Frank P; Sauther, Michelle L; Sponheimer, Matt; Ferguson, Virginia L

    2012-06-01

    The common morphological metrics of size, shape, and enamel thickness of teeth are believed to reflect the functional requirements of a primate's diet. However, the mechanical and material properties of enamel also contribute to tooth function, yet are rarely studied. Substantial wear and tooth loss previously documented in Lemur catta at the Beza Mahafaly Special Reserve suggests that their dental morphology, structure, and possibly their enamel are not adapted for their current fallback food (the mechanically challenging tamarind fruit). In this study, we investigate the nanomechanical properties, mineralization, and microstructure of the enamel of three sympatric lemur species to provide insight into their dietary functional adaptations. Mechanical properties measured by nanoindentation were compared to measurements of mineral content, prism orientation, prism size, and enamel thickness using electron microscopy. Mechanical properties of all species were similar near the enamel dentin junction and variations correlated with changes in microstructure (e.g., prism size) and mineral content. Severe wear and microcracking within L. catta's enamel were associated with up to a 43% reduction in nanomechanical properties in regions of cracking versus intact enamel. The mechanical and material properties of L. catta's enamel are similar to those of sympatric folivores and suggest that they are not uniquely mechanically adapted to consume the physically challenging tamarind fruit. An understanding of the material and mechanical properties of enamel is required to fully elucidate the functional and ecological adaptations of primate teeth.

  16. Predicting Ecological Responses of the Florida Everglades to Possible Future Climate Scenarios: Introduction

    NASA Astrophysics Data System (ADS)

    Aumen, Nicholas G.; Havens, Karl E.; Best, G. Ronnie; Berry, Leonard

    2015-04-01

    Florida's Everglades stretch from the headwaters of the Kissimmee River near Orlando to Florida Bay. Under natural conditions in this flat landscape, water flowed slowly downstream as broad, shallow sheet flow. The ecosystem is markedly different now, altered by nutrient pollution and construction of canals, levees, and water control structures designed for flood control and water supply. These alterations have resulted in a 50 % reduction of the ecosystem's spatial extent and significant changes in ecological function in the remaining portion. One of the world's largest restoration programs is underway to restore some of the historic hydrologic and ecological functions of the Everglades, via a multi-billion dollar Comprehensive Everglades Restoration Plan. This plan, finalized in 2000, did not explicitly consider climate change effects, yet today we realize that sea level rise and future changes in rainfall (RF), temperature, and evapotranspiration (ET) may have system-wide impacts. This series of papers describes results of a workshop where a regional hydrologic model was used to simulate the hydrology expected in 2060 with climate changes including increased temperature, ET, and sea level, and either an increase or decrease in RF. Ecologists with expertise in various areas of the ecosystem evaluated the hydrologic outputs, drew conclusions about potential ecosystem responses, and identified research needs where projections of response had high uncertainty. Resource managers participated in the workshop, and they present lessons learned regarding how the new information might be used to guide Everglades restoration in the context of climate change.

  17. Predicting ecological responses of the Florida Everglades to possible future climate scenarios: introduction.

    PubMed

    Aumen, Nicholas G; Havens, Karl E; Best, G Ronnie; Berry, Leonard

    2015-04-01

    Florida's Everglades stretch from the headwaters of the Kissimmee River near Orlando to Florida Bay. Under natural conditions in this flat landscape, water flowed slowly downstream as broad, shallow sheet flow. The ecosystem is markedly different now, altered by nutrient pollution and construction of canals, levees, and water control structures designed for flood control and water supply. These alterations have resulted in a 50% reduction of the ecosystem's spatial extent and significant changes in ecological function in the remaining portion. One of the world's largest restoration programs is underway to restore some of the historic hydrologic and ecological functions of the Everglades, via a multi-billion dollar Comprehensive Everglades Restoration Plan. This plan, finalized in 2000, did not explicitly consider climate change effects, yet today we realize that sea level rise and future changes in rainfall (RF), temperature, and evapotranspiration (ET) may have system-wide impacts. This series of papers describes results of a workshop where a regional hydrologic model was used to simulate the hydrology expected in 2060 with climate changes including increased temperature, ET, and sea level, and either an increase or decrease in RF. Ecologists with expertise in various areas of the ecosystem evaluated the hydrologic outputs, drew conclusions about potential ecosystem responses, and identified research needs where projections of response had high uncertainty. Resource managers participated in the workshop, and they present lessons learned regarding how the new information might be used to guide Everglades restoration in the context of climate change.

  18. Response diversity can increase ecological resilience to disturbance in coral reefs.

    PubMed

    Baskett, Marissa L; Fabina, Nicholas S; Gross, Kevin

    2014-08-01

    Community-level resilience depends on the interaction between multiple populations that vary in individual responses to disturbance. For example, in tropical reefs, some corals can survive higher stress (resistance) while others exhibit faster recovery (engineering resilience) following disturbances such as thermal stress. While each type will negatively affect the other through competition, each might also benefit the other by reducing the potential for an additional competitor such as macroalgae to invade after a disturbance. To determine how community composition affects ecological resilience, we modeled coral-macroalgae interactions given either a resistant coral, a resilient coral, or both together. Having both coral types (i.e., response diversity) can lead to observable enhanced ecological resilience if (1) the resilient coral is not a superior competitor and (2) disturbance levels are high enough such that the resilient coral would collapse when considered alone. This enhanced resilience occurs through competitor-enabled rescue where each coral increases the potential for the other to recover from disturbance through external recruitment, such that both corals benefit from the presence of each other in terms of total cover and resilience. Therefore, conservation management aimed at protecting resilience under global change requires consideration of both diversity and connectivity between sites experiencing differential disturbance.

  19. Reflexivity, knowledge and ecological awareness: premises for responsible action in the hospital work environment.

    PubMed

    Camponogara, Silviamar; Ramos, Flávia Regina Sousa; Kirchhof, Ana Lucia Cardoso

    2009-01-01

    The article aims to analyze the interface of reflexivity, knowledge and ecologic awareness in the context of hospital work, based on data collected in a qualitative case study carried out at a public hospital. Field observation data and interviews are discussed in the light of sociologic and philosophic references. Workers expressed the interface between knowledge and action, in which there is a cycle of lack of knowledge, automatism in the actions and lack of environmental awareness, posing limits to individual awareness and to responsibility towards environmental preservation. Increased debate and education, including the environmental issue, are needed in the context of hospital work. Although hospital work is reflexively affected by the environmental problem, that does not guarantee the reorientation of practices and responsible action towards the environment.

  20. 21 CFR 312.60 - General responsibilities of investigators.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false General responsibilities of investigators. 312.60 Section 312.60 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS FOR HUMAN USE INVESTIGATIONAL NEW DRUG APPLICATION Responsibilities of Sponsors...

  1. Investigating children's physical activity and sedentary behavior using ecological momentary assessment with mobile phones.

    PubMed

    Dunton, Genevieve F; Liao, Yue; Intille, Stephen S; Spruijt-Metz, Donna; Pentz, Maryann

    2011-06-01

    The risk of obesity during childhood can be significantly reduced through increased physical activity and decreased sedentary behavior. Recent technological advances have created opportunities for the real-time measurement of these behaviors. Mobile phones are ubiquitous and easy to use, and thus have the capacity to collect data from large numbers of people. The present study tested the feasibility, acceptability, and validity of an electronic ecological momentary assessment (EMA) protocol using electronic surveys administered on the display screen of mobile phones to assess children's physical activity and sedentary behaviors. A total of 121 children (ages 9-13, 51% male, 38% at risk for overweight/overweight) participated in EMA monitoring from Friday afternoon to Monday evening during children's nonschool time, with 3-7 surveys/day. Items assessed current activity (e.g., watching TV/movies, playing video games, active play/sports/exercising). Children simultaneously wore an Actigraph GT2M accelerometer. EMA survey responses were time-matched to total step counts and minutes of moderate-to-vigorous physical activity (MVPA) occurring in the 30 min before each EMA survey prompt. No significant differences between answered and unanswered EMA surveys were found for total steps or MVPA. Step counts and the likelihood of 5+ min of MVPA were significantly higher during EMA-reported physical activity (active play/sports/exercising) vs. sedentary behaviors (reading/computer/homework, watching TV/movies, playing video games, riding in a car) (P < 0.001). Findings generally support the acceptability and validity of a 4-day EMA protocol using mobile phones to measure physical activity and sedentary behavior in children during leisure time.

  2. The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project.

    PubMed

    Hudson, Lawrence N; Newbold, Tim; Contu, Sara; Hill, Samantha L L; Lysenko, Igor; De Palma, Adriana; Phillips, Helen R P; Alhusseini, Tamera I; Bedford, Felicity E; Bennett, Dominic J; Booth, Hollie; Burton, Victoria J; Chng, Charlotte W T; Choimes, Argyrios; Correia, David L P; Day, Julie; Echeverría-Londoño, Susy; Emerson, Susan R; Gao, Di; Garon, Morgan; Harrison, Michelle L K; Ingram, Daniel J; Jung, Martin; Kemp, Victoria; Kirkpatrick, Lucinda; Martin, Callum D; Pan, Yuan; Pask-Hale, Gwilym D; Pynegar, Edwin L; Robinson, Alexandra N; Sanchez-Ortiz, Katia; Senior, Rebecca A; Simmons, Benno I; White, Hannah J; Zhang, Hanbin; Aben, Job; Abrahamczyk, Stefan; Adum, Gilbert B; Aguilar-Barquero, Virginia; Aizen, Marcelo A; Albertos, Belén; Alcala, E L; Del Mar Alguacil, Maria; Alignier, Audrey; Ancrenaz, Marc; Andersen, Alan N; Arbeláez-Cortés, Enrique; Armbrecht, Inge; Arroyo-Rodríguez, Víctor; Aumann, Tom; Axmacher, Jan C; Azhar, Badrul; Azpiroz, Adrián B; Baeten, Lander; Bakayoko, Adama; Báldi, András; Banks, John E; Baral, Sharad K; Barlow, Jos; Barratt, Barbara I P; Barrico, Lurdes; Bartolommei, Paola; Barton, Diane M; Basset, Yves; Batáry, Péter; Bates, Adam J; Baur, Bruno; Bayne, Erin M; Beja, Pedro; Benedick, Suzan; Berg, Åke; Bernard, Henry; Berry, Nicholas J; Bhatt, Dinesh; Bicknell, Jake E; Bihn, Jochen H; Blake, Robin J; Bobo, Kadiri S; Bóçon, Roberto; Boekhout, Teun; Böhning-Gaese, Katrin; Bonham, Kevin J; Borges, Paulo A V; Borges, Sérgio H; Boutin, Céline; Bouyer, Jérémy; Bragagnolo, Cibele; Brandt, Jodi S; Brearley, Francis Q; Brito, Isabel; Bros, Vicenç; Brunet, Jörg; Buczkowski, Grzegorz; Buddle, Christopher M; Bugter, Rob; Buscardo, Erika; Buse, Jörn; Cabra-García, Jimmy; Cáceres, Nilton C; Cagle, Nicolette L; Calviño-Cancela, María; Cameron, Sydney A; Cancello, Eliana M; Caparrós, Rut; Cardoso, Pedro; Carpenter, Dan; Carrijo, Tiago F; Carvalho, Anelena L; Cassano, Camila R; Castro, Helena; Castro-Luna, Alejandro A; Rolando, Cerda B; Cerezo, Alexis; Chapman, Kim Alan; Chauvat, Matthieu; Christensen, Morten; Clarke, Francis M; Cleary, Daniel F R; Colombo, Giorgio; Connop, Stuart P; Craig, Michael D; Cruz-López, Leopoldo; Cunningham, Saul A; D'Aniello, Biagio; D'Cruze, Neil; da Silva, Pedro Giovâni; Dallimer, Martin; Danquah, Emmanuel; Darvill, Ben; Dauber, Jens; Davis, Adrian L V; Dawson, Jeff; de Sassi, Claudio; de Thoisy, Benoit; Deheuvels, Olivier; Dejean, Alain; Devineau, Jean-Louis; Diekötter, Tim; Dolia, Jignasu V; Domínguez, Erwin; Dominguez-Haydar, Yamileth; Dorn, Silvia; Draper, Isabel; Dreber, Niels; Dumont, Bertrand; Dures, Simon G; Dynesius, Mats; Edenius, Lars; Eggleton, Paul; Eigenbrod, Felix; Elek, Zoltán; Entling, Martin H; Esler, Karen J; de Lima, Ricardo F; Faruk, Aisyah; Farwig, Nina; Fayle, Tom M; Felicioli, Antonio; Felton, Annika M; Fensham, Roderick J; Fernandez, Ignacio C; Ferreira, Catarina C; Ficetola, Gentile F; Fiera, Cristina; Filgueiras, Bruno K C; Fırıncıoğlu, Hüseyin K; Flaspohler, David; Floren, Andreas; Fonte, Steven J; Fournier, Anne; Fowler, Robert E; Franzén, Markus; Fraser, Lauchlan H; Fredriksson, Gabriella M; Freire, Geraldo B; Frizzo, Tiago L M; Fukuda, Daisuke; Furlani, Dario; Gaigher, René; Ganzhorn, Jörg U; García, Karla P; Garcia-R, Juan C; Garden, Jenni G; Garilleti, Ricardo; Ge, Bao-Ming; Gendreau-Berthiaume, Benoit; Gerard, Philippa J; Gheler-Costa, Carla; Gilbert, Benjamin; Giordani, Paolo; Giordano, Simonetta; Golodets, Carly; Gomes, Laurens G L; Gould, Rachelle K; Goulson, Dave; Gove, Aaron D; Granjon, Laurent; Grass, Ingo; Gray, Claudia L; Grogan, James; Gu, Weibin; Guardiola, Moisès; Gunawardene, Nihara R; Gutierrez, Alvaro G; Gutiérrez-Lamus, Doris L; Haarmeyer, Daniela H; Hanley, Mick E; Hanson, Thor; Hashim, Nor R; Hassan, Shombe N; Hatfield, Richard G; Hawes, Joseph E; Hayward, Matt W; Hébert, Christian; Helden, Alvin J; Henden, John-André; Henschel, Philipp; Hernández, Lionel; Herrera, James P; Herrmann, Farina; Herzog, Felix; Higuera-Diaz, Diego; Hilje, Branko; Höfer, Hubert; Hoffmann, Anke; Horgan, Finbarr G; Hornung, Elisabeth; Horváth, Roland; Hylander, Kristoffer; Isaacs-Cubides, Paola; Ishida, Hiroaki; Ishitani, Masahiro; Jacobs, Carmen T; Jaramillo, Víctor J; Jauker, Birgit; Hernández, F Jiménez; Johnson, McKenzie F; Jolli, Virat; Jonsell, Mats; Juliani, S Nur; Jung, Thomas S; Kapoor, Vena; Kappes, Heike; Kati, Vassiliki; Katovai, Eric; Kellner, Klaus; Kessler, Michael; Kirby, Kathryn R; Kittle, Andrew M; Knight, Mairi E; Knop, Eva; Kohler, Florian; Koivula, Matti; Kolb, Annette; Kone, Mouhamadou; Kőrösi, Ádám; Krauss, Jochen; Kumar, Ajith; Kumar, Raman; Kurz, David J; Kutt, Alex S; Lachat, Thibault; Lantschner, Victoria; Lara, Francisco; Lasky, Jesse R; Latta, Steven C; Laurance, William F; Lavelle, Patrick; Le Féon, Violette; LeBuhn, Gretchen; Légaré, Jean-Philippe; Lehouck, Valérie; Lencinas, María V; Lentini, Pia E; Letcher, Susan G; Li, Qi; Litchwark, Simon A; Littlewood, Nick A; Liu, Yunhui; Lo-Man-Hung, Nancy; López-Quintero, Carlos A; Louhaichi, Mounir; Lövei, Gabor L; Lucas-Borja, Manuel Esteban; Luja, Victor H; Luskin, Matthew S; MacSwiney G, M Cristina; Maeto, Kaoru; Magura, Tibor; Mallari, Neil Aldrin; Malone, Louise A; Malonza, Patrick K; Malumbres-Olarte, Jagoba; Mandujano, Salvador; Måren, Inger E; Marin-Spiotta, Erika; Marsh, Charles J; Marshall, E J P; Martínez, Eliana; Martínez Pastur, Guillermo; Moreno Mateos, David; Mayfield, Margaret M; Mazimpaka, Vicente; McCarthy, Jennifer L; McCarthy, Kyle P; McFrederick, Quinn S; McNamara, Sean; Medina, Nagore G; Medina, Rafael; Mena, Jose L; Mico, Estefania; Mikusinski, Grzegorz; Milder, Jeffrey C; Miller, James R; Miranda-Esquivel, Daniel R; Moir, Melinda L; Morales, Carolina L; Muchane, Mary N; Muchane, Muchai; Mudri-Stojnic, Sonja; Munira, A Nur; Muoñz-Alonso, Antonio; Munyekenye, B F; Naidoo, Robin; Naithani, A; Nakagawa, Michiko; Nakamura, Akihiro; Nakashima, Yoshihiro; Naoe, Shoji; Nates-Parra, Guiomar; Navarrete Gutierrez, Dario A; Navarro-Iriarte, Luis; Ndang'ang'a, Paul K; Neuschulz, Eike L; Ngai, Jacqueline T; Nicolas, Violaine; Nilsson, Sven G; Noreika, Norbertas; Norfolk, Olivia; Noriega, Jorge Ari; Norton, David A; Nöske, Nicole M; Nowakowski, A Justin; Numa, Catherine; O'Dea, Niall; O'Farrell, Patrick J; Oduro, William; Oertli, Sabine; Ofori-Boateng, Caleb; Oke, Christopher Omamoke; Oostra, Vicencio; Osgathorpe, Lynne M; Otavo, Samuel Eduardo; Page, Navendu V; Paritsis, Juan; Parra-H, Alejandro; Parry, Luke; Pe'er, Guy; Pearman, Peter B; Pelegrin, Nicolás; Pélissier, Raphaël; Peres, Carlos A; Peri, Pablo L; Persson, Anna S; Petanidou, Theodora; Peters, Marcell K; Pethiyagoda, Rohan S; Phalan, Ben; Philips, T Keith; Pillsbury, Finn C; Pincheira-Ulbrich, Jimmy; Pineda, Eduardo; Pino, Joan; Pizarro-Araya, Jaime; Plumptre, A J; Poggio, Santiago L; Politi, Natalia; Pons, Pere; Poveda, Katja; Power, Eileen F; Presley, Steven J; Proença, Vânia; Quaranta, Marino; Quintero, Carolina; Rader, Romina; Ramesh, B R; Ramirez-Pinilla, Martha P; Ranganathan, Jai; Rasmussen, Claus; Redpath-Downing, Nicola A; Reid, J Leighton; Reis, Yana T; Rey Benayas, José M; Rey-Velasco, Juan Carlos; Reynolds, Chevonne; Ribeiro, Danilo Bandini; Richards, Miriam H; Richardson, Barbara A; Richardson, Michael J; Ríos, Rodrigo Macip; Robinson, Richard; Robles, Carolina A; Römbke, Jörg; Romero-Duque, Luz Piedad; Rös, Matthias; Rosselli, Loreta; Rossiter, Stephen J; Roth, Dana S; Roulston, T'ai H; Rousseau, Laurent; Rubio, André V; Ruel, Jean-Claude; Sadler, Jonathan P; Sáfián, Szabolcs; Saldaña-Vázquez, Romeo A; Sam, Katerina; Samnegård, Ulrika; Santana, Joana; Santos, Xavier; Savage, Jade; Schellhorn, Nancy A; Schilthuizen, Menno; Schmiedel, Ute; Schmitt, Christine B; Schon, Nicole L; Schüepp, Christof; Schumann, Katharina; Schweiger, Oliver; Scott, Dawn M; Scott, Kenneth A; Sedlock, Jodi L; Seefeldt, Steven S; Shahabuddin, Ghazala; Shannon, Graeme; Sheil, Douglas; Sheldon, Frederick H; Shochat, Eyal; Siebert, Stefan J; Silva, Fernando A B; Simonetti, Javier A; Slade, Eleanor M; Smith, Jo; Smith-Pardo, Allan H; Sodhi, Navjot S; Somarriba, Eduardo J; Sosa, Ramón A; Soto Quiroga, Grimaldo; St-Laurent, Martin-Hugues; Starzomski, Brian M; Stefanescu, Constanti; Steffan-Dewenter, Ingolf; Stouffer, Philip C; Stout, Jane C; Strauch, Ayron M; Struebig, Matthew J; Su, Zhimin; Suarez-Rubio, Marcela; Sugiura, Shinji; Summerville, Keith S; Sung, Yik-Hei; Sutrisno, Hari; Svenning, Jens-Christian; Teder, Tiit; Threlfall, Caragh G; Tiitsaar, Anu; Todd, Jacqui H; Tonietto, Rebecca K; Torre, Ignasi; Tóthmérész, Béla; Tscharntke, Teja; Turner, Edgar C; Tylianakis, Jason M; Uehara-Prado, Marcio; Urbina-Cardona, Nicolas; Vallan, Denis; Vanbergen, Adam J; Vasconcelos, Heraldo L; Vassilev, Kiril; Verboven, Hans A F; Verdasca, Maria João; Verdú, José R; Vergara, Carlos H; Vergara, Pablo M; Verhulst, Jort; Virgilio, Massimiliano; Vu, Lien Van; Waite, Edward M; Walker, Tony R; Wang, Hua-Feng; Wang, Yanping; Watling, James I; Weller, Britta; Wells, Konstans; Westphal, Catrin; Wiafe, Edward D; Williams, Christopher D; Willig, Michael R; Woinarski, John C Z; Wolf, Jan H D; Wolters, Volkmar; Woodcock, Ben A; Wu, Jihua; Wunderle, Joseph M; Yamaura, Yuichi; Yoshikura, Satoko; Yu, Douglas W; Zaitsev, Andrey S; Zeidler, Juliane; Zou, Fasheng; Collen, Ben; Ewers, Rob M; Mace, Georgina M; Purves, Drew W; Scharlemann, Jörn P W; Purvis, Andy

    2017-01-01

    The PREDICTS project-Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)-has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity.

  3. Toward an ecological analysis of Bayesian inferences: how task characteristics influence responses

    PubMed Central

    Hafenbrädl, Sebastian; Hoffrage, Ulrich

    2015-01-01

    In research on Bayesian inferences, the specific tasks, with their narratives and characteristics, are typically seen as exchangeable vehicles that merely transport the structure of the problem to research participants. In the present paper, we explore whether, and possibly how, task characteristics that are usually ignored influence participants’ responses in these tasks. We focus on both quantitative dimensions of the tasks, such as their base rates, hit rates, and false-alarm rates, as well as qualitative characteristics, such as whether the task involves a norm violation or not, whether the stakes are high or low, and whether the focus is on the individual case or on the numbers. Using a data set of 19 different tasks presented to 500 different participants who provided a total of 1,773 responses, we analyze these responses in two ways: first, on the level of the numerical estimates themselves, and second, on the level of various response strategies, Bayesian and non-Bayesian, that might have produced the estimates. We identified various contingencies, and most of the task characteristics had an influence on participants’ responses. Typically, this influence has been stronger when the numerical information in the tasks was presented in terms of probabilities or percentages, compared to natural frequencies – and this effect cannot be fully explained by a higher proportion of Bayesian responses when natural frequencies were used. One characteristic that did not seem to influence participants’ response strategy was the numerical value of the Bayesian solution itself. Our exploratory study is a first step toward an ecological analysis of Bayesian inferences, and highlights new avenues for future research. PMID:26300791

  4. Cognitive landscape and information: new perspectives to investigate the ecological complexity.

    PubMed

    Farina, Almo; Bogaert, Jan; Schipani, Ileana

    2005-01-01

    Landscape ecology deals with ecological processes in their spatial context. It shares with ecosystem ecology the primate of emergent ecological disciplines. The aim of this contribution is to approach the definition of landscapes using cognitive paradigms. Neutral-based landscape (NbL), individual-based landscape (IbL) and observed-based landscape (ObL) are defined to explore the cognitive mechanisms. NbL represents the undecoded component of the cognitive matrix. The IbL is the portion of landscape perceived by the biological sensors. ObL is the part of the cognitive matrix perceived using the cultural background of the observer. The perceived landscape (PL) is composed by the sum of these three approaches of landscape perception. Two further types of information (sensu Stonier) are recognized in this process of perception: the compressed information, as it is present inside the cognitive matrix, and the decompressed information that will structure the PL when a semiotic relationship operates between the organisms and the cognitive matrix. Scaling properties of these three PL components are recognized in space and time. In NbL scale seems irrelevant, in IbL the perception is filtered by organismic scaling and in ObL the spatio-temporal scale seems of major importance. Definitively, perception is scale-dependent. A combination of the cognitive approach with information paradigms to study landscapes opens new perspectives in the interpretation of ecological complexity.

  5. Species-specific differences in biomarker responses in two ecologically different earthworms exposed to the insecticide dimethoate.

    PubMed

    Velki, Mirna; Hackenberger, Branimir K

    2012-08-01

    Earthworms ingest large amounts of soil and therefore are continuously exposed to contaminants through their alimentary surfaces. Additionally, several studies have shown that earthworm skin is a significant route of contaminant uptake as well. In order to determine effects of dimethoate, a broad-spectrum organophosphorous insecticide, two ecologically different earthworm species were used - Eisenia andrei and Octolasion lacteum. Although several studies used soil organisms to investigate the effects of dimethoate, none of these studies included investigations of dimethoate effects on biochemical biomarkers in earthworms. Earthworms were exposed to 0.001, 0.005, 0.01, 0.5 and 1 μg/cm(2) of dimethoate for 24 h, and the activities of acetylcholinesterase, carboxylesterase, catalase and efflux pump were measured. In both earthworm species dimethoate caused significant inhibition of acetylcholinesterase and carboxylesterase activities, however in E. andrei an hormetic effect was evident. Efflux pump activity was inhibited only in E. andrei, and catalase activity was significantly inhibited in both earthworm species. Additionally, responses of earthworm acetylcholinesterase, carboxylesterase and catalase activity to dimethoate were examined through in vitro experiments. Comparison of responses between E. andrei and O. lacteum has shown significant differences, and E. andrei has proved to be less susceptible to dimethoate exposure.

  6. Investigation of air cleaning system response to accident conditions

    SciTech Connect

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S.; Martin, R.A.; Ricketts, C.I.; Smith, P.R.; Tang, P.K.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported.

  7. Ecological responses to experimental glacier-runoff reduction in alpine rivers

    PubMed Central

    Cauvy-Fraunié, Sophie; Andino, Patricio; Espinosa, Rodrigo; Calvez, Roger; Jacobsen, Dean; Dangles, Olivier

    2016-01-01

    Glacier retreat is a worldwide phenomenon with important consequences for the hydrological cycle and downstream ecosystem structure and functioning. To determine the effects of glacier retreat on aquatic communities, we conducted a 4-year flow manipulation in a tropical glacier-fed stream. Compared with an adjacent reference stream, meltwater flow reduction induces significant changes in benthic fauna community composition in less than 2 weeks. Also, both algal and herbivore biomass significantly increase in the manipulated stream as a response to flow reduction. After the flow reduction ceased, the system requires 14–16 months to return to its pre-perturbation state. These results are supported by a multi-stream survey of sites varying in glacial influence, showing an abrupt increase in algal and herbivore biomass below 11% glacier cover in the catchment. This study shows that flow reduction strongly affects glacier-fed stream biota, prefiguring profound ecological effects of ongoing glacier retreat on aquatic systems. PMID:27338650

  8. Assessment of soil sealing management responses, strategies, and targets toward ecologically sustainable urban land use management.

    PubMed

    Artmann, Martina

    2014-05-01

    Soil sealing has negative impacts on ecosystem services since urban green and soil get lost. Although there is political commitment to stop further sealing, no reversal of this trend can be observed in Europe. This paper raises the questions (1) which strategies can be regarded as being efficient toward ecologically sustainable management of urban soil sealing and (2) who has competences and should take responsibility to steer soil sealing? The analyses are conducted in Germany. The assessment of strategies is carried out using indicators as part of a content analysis. Legal-planning, informal-planning, economic-fiscal, co-operative, and informational strategies are analyzed. Results show that there is a sufficient basis of strategies to secure urban ecosystem services by protecting urban green and reducing urban gray where microclimate regulation is a main target. However, soil sealing management lacks a spatial strategically overview as well as the consideration of services provided by fertile soils.

  9. Ecological responses to experimental glacier-runoff reduction in alpine rivers

    NASA Astrophysics Data System (ADS)

    Cauvy-Fraunié, Sophie; Andino, Patricio; Espinosa, Rodrigo; Calvez, Roger; Jacobsen, Dean; Dangles, Olivier

    2016-06-01

    Glacier retreat is a worldwide phenomenon with important consequences for the hydrological cycle and downstream ecosystem structure and functioning. To determine the effects of glacier retreat on aquatic communities, we conducted a 4-year flow manipulation in a tropical glacier-fed stream. Compared with an adjacent reference stream, meltwater flow reduction induces significant changes in benthic fauna community composition in less than 2 weeks. Also, both algal and herbivore biomass significantly increase in the manipulated stream as a response to flow reduction. After the flow reduction ceased, the system requires 14-16 months to return to its pre-perturbation state. These results are supported by a multi-stream survey of sites varying in glacial influence, showing an abrupt increase in algal and herbivore biomass below 11% glacier cover in the catchment. This study shows that flow reduction strongly affects glacier-fed stream biota, prefiguring profound ecological effects of ongoing glacier retreat on aquatic systems.

  10. Identifying Droughts by Modeling the Hydrologic and Ecologic Responses in the Medjerda River Basin, Tunisia

    NASA Astrophysics Data System (ADS)

    Sawada, Y.; Koike, T.; Jaranilla-sanchez, P. A.

    2013-12-01

    Drought brings severe damage to water and agricultural resources, and both of hydrological and ecological responses are important for understanding droughts. However, the ecological contributions to drought characteristics at the basin scale have not been quantified. To address this issue, we developed an eco-hydrological model that can calculate vegetation dynamics as a diagnostic valuable in a distributed-hydrological modeling framework and identified different drought types in the Medjerda River Basin where drought is a predominant issue. From the inputs and outputs of the model, we calculate drought indices for different drought types. The model shows reliable accuracy in reproducing the observed river discharge and the satellite observed leaf area index in the long-term (19-year) simulation. Moreover, the drought index calculated from model estimated annual peak of leaf area index is well correlated (correlation coefficient; r = 0.89; see Figure) with drought index from nationwide annual crop production, which show the modeled leaf area index has enough capacity to reproducing agricultural droughts that can be related with historical food shortage on 1988-1989 and 1993-1995. Our model can estimate vegetation dynamics and water cycle simultaneously in the enough accuracy to analyze the basin-scale agricultural and hydrological droughts separately. We clarify that vegetation dynamics has quicker response to meteorological droughts than river discharge and groundwater dynamics in Medjerda River Basin because vegetation dynamics is sensitive to soil moisture in surface layers while soil moisture in deeper layers strongly contributes to stream flow and depth of groundwater level. Therefore, historical agricultural droughts predominantly occurred prior to hydrological droughts and in the 1988-1989 drought, the hydrological drought lasted much longer even after crop production recovered. Standardized anomaly index (SA) for estimated annual maximum leaf area index

  11. Consequences of ecological, evolutionary and biogeochemical uncertainty for coral reef responses to climatic stress.

    PubMed

    Mumby, Peter J; van Woesik, Robert

    2014-05-19

    Coral reefs are highly sensitive to the stress associated with greenhouse gas emissions, in particular ocean warming and acidification. While experiments show negative responses of most reef organisms to ocean warming, some autotrophs benefit from ocean acidification. Yet, we are uncertain of the response of coral reefs as systems. We begin by reviewing sources of uncertainty and complexity including the translation of physiological effects into demographic processes, indirect ecological interactions among species, the ability of coral reefs to modify their own chemistry, adaptation and trans-generational plasticity. We then incorporate these uncertainties into two simple qualitative models of a coral reef system under climate change. Some sources of uncertainty are far more problematic than others. Climate change is predicted to have an unambiguous negative effect on corals that is robust to several sources of uncertainty but sensitive to the degree of biogeochemical coupling between benthos and seawater. Macroalgal, zoanthid, and herbivorous fish populations are generally predicted to increase, but the ambiguity (confidence) of such predictions are sensitive to the source of uncertainty. For example, reversing the effect of climate-related stress on macroalgae from being positive to negative had no influence on system behaviour. By contrast, the system was highly sensitive to a change in the stress upon herbivorous fishes. Minor changes in competitive interactions had profound impacts on system behaviour, implying that the outcomes of mesocosm studies could be highly sensitive to the choice of taxa. We use our analysis to identify new hypotheses and suggest that the effects of climatic stress on coral reefs provide an exceptional opportunity to test emerging theories of ecological inheritance.

  12. Rapid Ecological Change in Two Contrasting Lake Ecosystems: Evidence of Threshold Responses, Altered Species Dynamics, and Perturbed Patterns of Variability

    NASA Astrophysics Data System (ADS)

    Simpson, G. L.

    2015-12-01

    Studying threshold responses to environmental change is often made difficult due to the paucity of monitoring data prior to and during change. Progress has been made via theoretical models of regime shifts or experimental manipulation but natural, real world, examples of threshold change are limited and in many cases inconclusive. Lake sediments provide the potential to examine abrupt ecological change by directly observing how species, communities, and biogeochemical proxies responded to environmental perturbation or recorded ecosystem change. These records are not problem-free; age uncertainties, uneven and variable temporal resolution, and time-consuming taxonomic work all act to limit the scope and scale of the data or complicate its analysis. Here I use two annually laminated records 1. Kassjön, a seasonally anoxic mesotrophic lake in N Sweden, and2. Baldeggersee, a nutrient rich, hardwater lake on the central Swiss Plateau to investigate lake ecosystem responses to abrupt environmental change using ideal paleoecological time series. Rapid cooling 2.2kyr ago in northern Sweden significantly perturbed the diatom community of Kassjön. Using wavelet analysis, this amelioration in climate also fundamentally altered patterns of variance in diatom abundances, suppressing cyclicity in species composition that required several hundred years to reestablish. Multivariate wavelet analysis of the record showed marked switching between synchronous and asynchronous species dynamics in response to rapid climatic cooling and subsequent warming. Baldeggersee has experienced a long history of eutrophication and the diatom record has been used as a classic illustration of a regime shift in response to nutrient loading. Time series analysis of the record identified some evidence of a threshold-like response in the diatoms. A stochastic volatility model identified increasing variance in composition prior to the threshold, as predicted from theory, and a switch from compensatory

  13. Evolution in response to direct and indirect ecological effects in pitcher plant inquiline communities.

    PubMed

    terHorst, Casey P

    2010-12-01

    Ecologists have long recognized the importance of indirect ecological effects on species abundances, coexistence, and diversity. However, the evolutionary consequences of indirect interactions are rarely considered. Here I conduct selection experiments and examine the evolutionary response of Colpoda sp., a ciliated protozoan, to other members of the inquiline community of purple pitcher plants (Sarracenia purpurea). I measured the evolution of six traits in response to (1) predation by mosquito larvae, (2) competition from other ciliated protozoans, and (3) simultaneous predation and competition. The latter treatment incorporated both direct effects and indirect effects due to interactions between predators and competitors. Population growth rate and cell size evolved in response to direct effects of predators and competitors. However, trait values in the multispecies treatment were similar to those in the monoculture treatment, indicating that direct effects were offset by strong indirect effects on the evolution of traits. For most of the traits measured, indirect effects were opposed to, and often stronger than, direct effects. These indirect effects occurred as a result of behavioral changes of the predator in the presence of competitors and as a result of reduced densities of competitors in the presence of predators. Incorporating indirect effects provides a more realistic description of how species evolve in complex natural communities.

  14. How groups cope with collective responsibility for ecological problems: Symbolic coping and collective emotions.

    PubMed

    Caillaud, Sabine; Bonnot, Virginie; Ratiu, Eugenia; Krauth-Gruber, Silvia

    2016-06-01

    This study explores the way groups cope with collective responsibility for ecological problems. The social representations approach was adopted, and the collective symbolic coping model was used as a frame of analysis, integrating collective emotions to enhance the understanding of coping processes. The original feature of this study is that the analysis is at group level. Seven focus groups were conducted with French students. An original use of focus groups was proposed: Discussions were structured to induce feelings of collective responsibility and enable observation of how groups cope with such feelings at various levels (social knowledge; social identities; group dynamics). Two analyses were conducted: Qualitative analysis of participants' use of various kinds of knowledge, social categories and the group dynamics, and lexicometric analysis to reveal how emotions varied during the different discussion phases. Results showed that groups' emotional states moved from negative to positive: They used specific social categories and resorted to shared stereotypes to cope with collective responsibility and maintain the integrity of their worldview. Only then did debate become possible again; it was anchored in the nature-culture dichotomy such that groups switched from group-based to system-based emotions.

  15. The Use of the Mounds of Lasius flavus in Teaching Some Principles of Ecological Investigation

    ERIC Educational Resources Information Center

    King, T. J.; Woodell, S. R. J.

    1975-01-01

    Outlines the ecology of Lasius flavus ant hill, describes sampling techniques for the determination of the species composition of the surrounding vegetation, presents a table of typical results from an ant-hill practical, and lists suggestions for further experiments. (GS)

  16. An Investigation of the Ecological and Social Impacts Caused by Rock Climbers.

    ERIC Educational Resources Information Center

    Attarian, Aram

    This study examined the ecological and social impacts of rock climbing. The survey included climbing sites in 10 federal areas, 2 state parks, 1 private area, and 1 city park. Resource managers provided information on the observed impacts of rock climbing and current management practices to minimize impacts. Survey results indicate: (1) 71 percent…

  17. Investigating the LGBTQ Responsive Model for Supervision of Group Work

    ERIC Educational Resources Information Center

    Luke, Melissa; Goodrich, Kristopher M.

    2013-01-01

    This article reports an investigation of the LGBTQ Responsive Model for Supervision of Group Work, a trans-theoretical supervisory framework to address the needs of lesbian, gay, bisexual, transgender, and questioning (LGBTQ) persons (Goodrich & Luke, 2011). Findings partially supported applicability of the LGBTQ Responsive Model for Supervision…

  18. Response of aquatic invertebrates to ecological rehabilitation of Southeastern USA depressional wetlands.

    SciTech Connect

    Batzer, Donald P.; Taylor, Barbera E.

    2015-07-02

    Abstract We assessed aquatic invertebrate response to ecological rehabilitation treatment in 20 depression wetlands on the Savannah River Site, South Carolina, USA. All wetlands had been ditched for 50+ years. Sixteen of the 20 wetlands received rehabilitation treatment, and four wetlands remained untreated as a control group. Treatment included logging of all trees, plugging drainage ditches, and planting wetland trees and grasses. Hydroperiods were consequently extended in most of the treatment wetlands. As part a larger study, we sampled macroinvertebrates and microcrustaceans during the pre-habilitation (1998–2000) and rehabilitation (2001–2003) phases. Our study spanned 2 years of high rainfall (1998 and 2003) and 4 years of low rainfall (1999–2002). Samples were collected bimonthly from any wetlands holding water. Macroinvertebrate assemblages in treatment wetlands in 2003 had changed from previous years (1998–2002) and compared to control wetlands (1998–2003), with abundances of Baetidae, Coenagrionidae, Dytiscidae, Chironomidae, and Chaoboridae driving variation. For microcrustaceans (Copepoda and Branchiopoda, including Cladocera, Anostraca and Laevicaudata), assemblage composition and species richness responded mainly to hydrologic conditions. Rehabilitation efforts in these wetlands induced diverse and abundant invertebrate communities to develop, but some responses appeared opportunistic; several taxa that benefitted were not typical residents of depressional wetlands in the region.

  19. Thermal ecology of the fiddler crab Uca panacea: Thermal constraints and organismal responses.

    PubMed

    Darnell, M Zachary; Nicholson, Haley S; Munguia, Pablo

    2015-08-01

    Temperature is one of the primary environmental variables limiting organismal performance, fitness, and species distributions. Yet, understanding temperature effects requires thorough exploration of thermal constraints and organismal responses that can translate to fitness and non-lethal long-term consequences under both constant and changing thermal regimes. We examined the thermal ecology of the fiddler crab Uca panacea, including critical thermal limits, thermal sensitivity of locomotion, operative environmental temperatures, preferred body temperatures, and acclimation ability. Operative environmental temperatures frequently reached the critical thermal maximum (41.8±0.8°C, mean ± s.e.m.), especially in unvegetated microhabitats, indicating the need for behavioral thermoregulation to maintain diurnal activity patterns. Preferred body temperatures (21.1-28.6°C) were substantially below the thermal optimum (30-40°C), although further research is needed to determine the driver of this mismatch. Critical thermal limits shifted 2-4°C in response to exposure to low (20°C) or high (35°C) temperatures, with full acclimation occurring in approximately 9d. This capacity for rapid acclimation, combined with the capacity for behavioral thermoregulation, is a strong candidate mechanism that explains the broad habitat use and could help explain the successful pantropical distribution of fiddler crabs.

  20. Direct defense or ecological costs: responses of herbivorous beetles to volatiles released by wild Lima bean (Phaseolus lunatus).

    PubMed

    Heil, Martin

    2004-06-01

    In response to feeding damage, Lima bean releases herbivore-induced plant volatiles (HIPV), which are generally assumed to attract carnivorous arthropods as an indirect defense. While many studies have focused on such tritrophic interactions, few have investigated effects of HIPV on herbivores. I used natural herbivores of wild Lima bean and studied their responses to jasmonic acid-induced plants in an olfactometer and in feeding trials. Both Cerotoma ruficornis and Gynandrobrotica guerreroensis (Chrysomelidae) significantly preferred control plants to induced ones in the olfactometer, and they avoided feeding on induced plants. In contrast, Curculionidae significantly preferred HIPV of the induced plant to those of the control in one plant pair and did not choose in the case of a second pair. In feeding trials, no choice occurred in the first plant pair, while control leaves were preferred in the second. Release of HIPV deterred Chrysomelid herbivores and, thus, acted as a direct defense. This may be an important addition to indirect defensive effects. Whether or not HIPV released by induced plants attracted herbivorous Curculionidae, thus incurring ecological costs, varied among plants. Such differences could be related to various HIPV blends released by individual plants.

  1. Investigating the evolution of apoptosis in malaria parasites: the importance of ecology

    PubMed Central

    2010-01-01

    Apoptosis is a precisely regulated process of cell death which occurs widely in multicellular organisms and is essential for normal development and immune defences. In recent years, interest has grown in the occurrence of apoptosis in unicellular organisms. In particular, as apoptosis has been reported in a wide range of species, including protozoan malaria parasites and trypanosomes, it may provide a novel target for intervention. However, it is important to understand when and why parasites employ an apoptosis strategy before the likely long- and short-term success of such an intervention can be evaluated. The occurrence of apoptosis in unicellular parasites provides a challenge for evolutionary theory to explain as organisms are expected to have evolved to maximise their own proliferation, not death. One possible explanation is that protozoan parasites undergo apoptosis in order to gain a group benefit from controlling their density as this prevents premature vector mortality. However, experimental manipulations to examine the ultimate causes behind apoptosis in parasites are lacking. In this review, we focus on malaria parasites to outline how an evolutionary framework can help make predictions about the ecological circumstances under which apoptosis could evolve. We then highlight the ecological considerations that should be taken into account when designing evolutionary experiments involving markers of cell death, and we call for collaboration between researchers in different fields to identify and develop appropriate markers in reference to parasite ecology and to resolve debates on terminology. PMID:21080937

  2. DOE responses to Ecology review comments for ``Sampling and analysis plans for the 100-D Ponds voluntary remediation project``

    SciTech Connect

    1996-12-31

    The Sampling and Analysis Plan describes the sampling and analytical activities which will be performed to support closure of the 100-D Ponds at the Hanford Reservation. This report contains responses by the US Department of Energy to Ecology review for ``Sampling and Analysis Plan for the 100-D Ponds Voluntary Remediation Project.``

  3. Toward Resonant, Imaginative Experiences in Ecological and Democratic Education. A Response to "Imagination and Experience: An Integrative Framework"

    ERIC Educational Resources Information Center

    Derby, Michael; Blenkinsop, Sean; Telford, John; Piersol, Laura; Caulkins, Michael

    2013-01-01

    In this response to Fettes's "Imagination and Experience," the authors further consider the varieties of educational experience that inspire ecological flourishing and a living democracy. The essential interconnectedness of encounter-driven and language-driven ways of knowing are explored with particular reference to the authors'…

  4. Linking Ecology and Epidemiology to Understand Predictors of Multi-Host Responses to an Emerging Pathogen, the Amphibian Chytrid Fungus.

    PubMed

    Gervasi, Stephanie S; Stephens, Patrick R; Hua, Jessica; Searle, Catherine L; Xie, Gisselle Yang; Urbina, Jenny; Olson, Deanna H; Bancroft, Betsy A; Weis, Virginia; Hammond, John I; Relyea, Rick A; Blaustein, Andrew R

    2017-01-01

    Variation in host responses to pathogens can have cascading effects on populations and communities when some individuals or groups of individuals display disproportionate vulnerability to infection or differ in their competence to transmit infection. The fungal pathogen, Batrachochytrium dendrobatidis (Bd) has been detected in almost 700 different amphibian species and is implicated in numerous global amphibian population declines. Identifying key hosts in the amphibian-Bd system-those who are at greatest risk or who pose the greatest risk for others-is challenging due in part to many extrinsic environmental factors driving spatiotemporal Bd distribution and context-dependent host responses to Bd in the wild. One way to improve predictive risk models and generate testable mechanistic hypotheses about vulnerability is to complement what we know about the spatial epidemiology of Bd with data collected through comparative experimental studies. We used standardized pathogen challenges to quantify amphibian survival and infection trajectories across 20 post-metamorphic North American species raised from eggs. We then incorporated trait-based models to investigate the predictive power of phylogenetic history, habitat use, and ecological and life history traits in explaining responses to Bd. True frogs (Ranidae) displayed the lowest infection intensities, whereas toads (Bufonidae) generally displayed the greatest levels of mortality after Bd exposure. Affiliation with ephemeral aquatic habitat and breadth of habitat use were strong predictors of vulnerability to and intensity of infection and several other traits including body size, lifespan, age at sexual maturity, and geographic range also appeared in top models explaining host responses to Bd. Several of the species examined are highly understudied with respect to Bd such that this study represents the first experimental susceptibility data. Combining insights gained from experimental studies with observations of

  5. Linking Ecology and Epidemiology to Understand Predictors of Multi-Host Responses to an Emerging Pathogen, the Amphibian Chytrid Fungus

    PubMed Central

    Stephens, Patrick R.; Hua, Jessica; Searle, Catherine L.; Xie, Gisselle Yang; Urbina, Jenny; Olson, Deanna H.; Bancroft, Betsy A.; Weis, Virginia; Hammond, John I.; Relyea, Rick A.; Blaustein, Andrew R.

    2017-01-01

    Variation in host responses to pathogens can have cascading effects on populations and communities when some individuals or groups of individuals display disproportionate vulnerability to infection or differ in their competence to transmit infection. The fungal pathogen, Batrachochytrium dendrobatidis (Bd) has been detected in almost 700 different amphibian species and is implicated in numerous global amphibian population declines. Identifying key hosts in the amphibian-Bd system–those who are at greatest risk or who pose the greatest risk for others–is challenging due in part to many extrinsic environmental factors driving spatiotemporal Bd distribution and context-dependent host responses to Bd in the wild. One way to improve predictive risk models and generate testable mechanistic hypotheses about vulnerability is to complement what we know about the spatial epidemiology of Bd with data collected through comparative experimental studies. We used standardized pathogen challenges to quantify amphibian survival and infection trajectories across 20 post-metamorphic North American species raised from eggs. We then incorporated trait-based models to investigate the predictive power of phylogenetic history, habitat use, and ecological and life history traits in explaining responses to Bd. True frogs (Ranidae) displayed the lowest infection intensities, whereas toads (Bufonidae) generally displayed the greatest levels of mortality after Bd exposure. Affiliation with ephemeral aquatic habitat and breadth of habitat use were strong predictors of vulnerability to and intensity of infection and several other traits including body size, lifespan, age at sexual maturity, and geographic range also appeared in top models explaining host responses to Bd. Several of the species examined are highly understudied with respect to Bd such that this study represents the first experimental susceptibility data. Combining insights gained from experimental studies with observations of

  6. Ecological Investigations of the Federally Endangered Shivwits Milk-Vetch (Astragalus ampullarioides)--2006 Annual Report

    USGS Publications Warehouse

    Miller, Mark E.; Mann, Rebecca K.; Goldstein, Harland L.; Yount, James D.

    2007-01-01

    Astragalus ampullarioides (Welsh) Welsh, the Shivwits milk-vetch, is an herbaceous perennial legume that was listed as federally endangered in September 2001. Known populations of this edaphic endemic species are restricted to Washington County, Utah, with the majority of occurrences found on gently sloping outcrops of the Triassic Petrified Forest Member of the Chinle Formation at the edge of the Mojave Desert. At the time of listing in 2001, surveys estimated a total of 1000 individuals for the species. In April-May 2006, surveys estimated approximately 4205 individuals distributed among six populations. Of the total number of individuals estimated in spring 2006, over 75 percent were distributed among three subpopulations in Zion National Park and approximately 60 percent occurred at a single 0.3-ha site in the Park. In addition to small population sizes and limited geographic distributions, the species is threatened to varying degrees by urbanization, livestock grazing, off-road vehicle use, and invasive exotic plants. In April 2006, the U.S. Geological Survey (USGS) initiated ecological investigations of the Shivwits milk-vetch to support conservation management and recovery of the species by the National Park Service (NPS; Zion National Park), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM), the Shivwits Band of the Paiute Tribe, and other cooperators such as The Nature Conservancy of Utah (TNC). To date, funding for this research has been provided by the Southwest Biological Science Center of the USGS Biological Resources Discipline, the USGS-NPS Park-Oriented Biological Support Project, and the Earth Surface Dynamics Program of the USGS Geologic Discipline. Additional logistical support has been provided by the Bureau of Land Management, Grand Staircase-Escalante National Monument. General objectives of this research are (1) to develop a better understanding of species-environment relations to support habitat modelling

  7. Ecological Stoichiometry and Density Responses of Plant-Arthropod Communities on Cormorant Nesting Islands

    PubMed Central

    Kolb, Gundula S.; Palmborg, Cecilia; Hambäck, Peter A.

    2013-01-01

    Seabirds deposit large amounts of nutrient rich guano on their nesting islands. The increased nutrient availability strongly affects plants and consumers. Consumer response differs among taxonomic groups, but mechanisms causing these differences are poorly understood. Ecological stoichiometry might provide tools to understand these mechanisms. ES suggests that nutrient rich taxa are more likely to be nutrient limited than nutrient poorer taxa and are more favored under nutrient enrichment. Here, we quantified differences in the elemental composition of soil, plants, and consumers between islands with and without nesting cormorant colonies and tested predictions made based on ES by relating the elemental composition and the eventual mismatch between consumer and resource stoichiometry to observed density differences among the island categories. We found that nesting cormorants radically changed the soil nutrient content and thereby indirectly plant nutrient content and resource quality to herbivores. In contrast, consumers showed only small differences in their elemental composition among the island categories. While we cannot evaluate the cause of the apparent homeostasis of invertebrates without additional data, we can conclude that from the perspective of the next trophic level, there is no difference in diet quality (in terms of N and P content) between island categories. Thus, bottom-up effects seemed mainly be mediated via changes in resource quantity not quality. Despite a large potential trophic mismatch we were unable to observe any relation between the invertebrate stoichiometry and their density response to nesting cormorant colonies. We conclude that in our system stoichiometry is not a useful predictor of arthropod responses to variation in resource nutrient content. Furthermore, we found no strong evidence that resource quality was a prime determinant of invertebrate densities. Other factors like resource quantity, habitat structure and species

  8. Ecological stoichiometry and density responses of plant-arthropod communities on cormorant nesting islands.

    PubMed

    Kolb, Gundula S; Palmborg, Cecilia; Hambäck, Peter A

    2013-01-01

    Seabirds deposit large amounts of nutrient rich guano on their nesting islands. The increased nutrient availability strongly affects plants and consumers. Consumer response differs among taxonomic groups, but mechanisms causing these differences are poorly understood. Ecological stoichiometry might provide tools to understand these mechanisms. ES suggests that nutrient rich taxa are more likely to be nutrient limited than nutrient poorer taxa and are more favored under nutrient enrichment. Here, we quantified differences in the elemental composition of soil, plants, and consumers between islands with and without nesting cormorant colonies and tested predictions made based on ES by relating the elemental composition and the eventual mismatch between consumer and resource stoichiometry to observed density differences among the island categories. We found that nesting cormorants radically changed the soil nutrient content and thereby indirectly plant nutrient content and resource quality to herbivores. In contrast, consumers showed only small differences in their elemental composition among the island categories. While we cannot evaluate the cause of the apparent homeostasis of invertebrates without additional data, we can conclude that from the perspective of the next trophic level, there is no difference in diet quality (in terms of N and P content) between island categories. Thus, bottom-up effects seemed mainly be mediated via changes in resource quantity not quality. Despite a large potential trophic mismatch we were unable to observe any relation between the invertebrate stoichiometry and their density response to nesting cormorant colonies. We conclude that in our system stoichiometry is not a useful predictor of arthropod responses to variation in resource nutrient content. Furthermore, we found no strong evidence that resource quality was a prime determinant of invertebrate densities. Other factors like resource quantity, habitat structure and species

  9. Summary of investigations of engine response to distorted inlet conditions

    NASA Technical Reports Server (NTRS)

    Biesiadny, T. J.; Braithwaite, W. M.; Soeder, R. H.; Abdelwahab, M.

    1986-01-01

    A survey is presented of experimental and analytical experience of the NASA Lewis Research Center in engine response to inlet temperature and pressure distortions. This includes a description of the hardware and techniques employed, and a summary of the highlights of experimental investigations and analytical modeling. Distortion devices successfully simulated inlet distortion, and knowledge was gained about compression system response to different types of distortion. A list of NASA research references is included.

  10. ERTS-1 investigation of ecological effects of strip mining in eastern Ohio

    NASA Technical Reports Server (NTRS)

    Chase, P. E.; Pettyjohn, W. A.

    1973-01-01

    Evidence is presented of ERTS capability to detect, map and monitor the effects of strip mining. Both enlarge ERTS imagery and statistically processed outline maps and imagery of stripped earth and standing water are compared to aerial photos of a strip mine near Coshocton, Ohio. The outline maps and decision imagery are at present limited to forming a disruption map of recently mined and unreclaimed earth and the resultant standing water within the mined area. It is planned to prepare a map of the reclaimed areas (reclamation map) within the stripped area and to detect and identify ecological effects such as vegetation kills and stream sedimentation external to the stripped areas.

  11. Estimating hydrologic and erosion response for use in ecological site descriptions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ecological resilience of rangeland landscapes is strongly related to eco-hydrologic pattern-process feedbacks that regulate the retention or loss of water and soil resources. However, key ecohydrologic information is often lacking in Ecological Site Descriptions (ESDs) used to guide management of ra...

  12. Value Assessment of Ecosystem Services in Nature Reserves in Ningxia, China: A Response to Ecological Restoration

    PubMed Central

    Wang, Yan; Gao, Jixi; Wang, Jinsheng; Qiu, Jie

    2014-01-01

    Changes in land use can cause significant changes in the ecosystem structure and process variation of ecosystem services. This study presents a detailed spatial, quantitative assessment of the variation in the value of ecosystem services based on land use change in national nature reserves of the Ningxia autonomous region in China. We used areas of land use types calculated from the remote sensing data and the adjusted value coefficients to assess the value of ecosystem services for the years 2000, 2005, and 2010, analyzing the fluctuations in the valuation of ecosystem services in response to land use change. With increases in the areas of forest land and water bodies, the value of ecosystem services increased from 182.3×107 to 223.8×107 US$ during 2000–2010. Grassland and forest land accounted for 90% of this increase. The values of all ecosystem services increased during this period, especially the value of ecosystem services for biodiversity protection and soil formation and protection. Ecological restoration in the reserves had a positive effect on the value of ecosystem services during 2000–2010. PMID:24586571

  13. Value assessment of ecosystem services in nature reserves in Ningxia, China: a response to ecological restoration.

    PubMed

    Wang, Yan; Gao, Jixi; Wang, Jinsheng; Qiu, Jie

    2014-01-01

    Changes in land use can cause significant changes in the ecosystem structure and process variation of ecosystem services. This study presents a detailed spatial, quantitative assessment of the variation in the value of ecosystem services based on land use change in national nature reserves of the Ningxia autonomous region in China. We used areas of land use types calculated from the remote sensing data and the adjusted value coefficients to assess the value of ecosystem services for the years 2000, 2005, and 2010, analyzing the fluctuations in the valuation of ecosystem services in response to land use change. With increases in the areas of forest land and water bodies, the value of ecosystem services increased from 182.3×10(7) to 223.8×10(7) US$ during 2000-2010. Grassland and forest land accounted for 90% of this increase. The values of all ecosystem services increased during this period, especially the value of ecosystem services for biodiversity protection and soil formation and protection. Ecological restoration in the reserves had a positive effect on the value of ecosystem services during 2000-2010.

  14. Ecological restoration and effect investigation of a river wetland in a semi-arid region, China

    NASA Astrophysics Data System (ADS)

    Xu, S.; Jiang, X.; Liu, Y.; Fu, Y.; Zhao, Q.

    2015-05-01

    River wetlands are heavily impacted by human intervention. The degradation and loss of river wetlands has made the restoration of river ecosystems a top priority. How to rehabilitate rivers and their services has been a research focus. The main goal of it is to restore the river wetland ecosystems with ecological methods. The Gudong River was selected as a study site in Chaoyang city in this study. Based on the analysis of interference factors in the river wetland degradation, a set of restoration techniques were proposed and designed for regional water level control, including submerged dikes, ecological embankments, revegetation and dredging. The restoration engineering has produced good results in water quality, eco-environment, and landscape. Monthly reports of the Daling River show that the water quality of Gudong River was better than Grade III in April 2013 compared with Grade V in May 2012. The economic benefit after restoration construction is 1.71 million RMB per year, about 1.89 times that before. The ratio of economic value, social value and eco-environmental value is 1:4:23.

  15. Culture-Dependent and -Independent Methods To Investigate the Microbial Ecology of Italian Fermented Sausages

    PubMed Central

    Rantsiou, Kalliopi; Urso, Rosalinda; Iacumin, Lucilla; Cantoni, Carlo; Cattaneo, Patrizia; Comi, Giuseppe; Cocolin, Luca

    2005-01-01

    In this study, the microbial ecology of three naturally fermented sausages produced in northeast Italy was studied by culture-dependent and -independent methods. By plating analysis, the predominance of lactic acid bacteria populations was pointed out, as well as the importance of coagulase-negative cocci. Also in the case of one fermentation, the fecal enterocci reached significant counts, highlighting their contribution to the particular transformation process. Yeast counts were higher than the detection limit (>100 CFU/g) in only one fermented sausage. Analysis of the denaturing gradient gel electrophoresis (DGGE) patterns and sequencing of the bands allowed profiling of the microbial populations present in the sausages during fermentation. The bacterial ecology was mainly characterized by the stable presence of Lactobacillus curvatus and Lactobacillus sakei, but Lactobacillus paracasei was also repeatedly detected. An important piece of evidence was the presence of Lactococcus garvieae, which clearly contributed in two fermentations. Several species of Staphylococcus were also detected. Regarding other bacterial groups, Bacillus sp., Ruminococcus sp., and Macrococcus caseolyticus were also identified at the beginning of the transformations. In addition, yeast species belonging to Debaryomyces hansenii, several Candida species, and Willopsis saturnus were observed in the DGGE gels. Finally, cluster analysis of the bacterial and yeast DGGE profiles highlighted the uniqueness of the fermentation processes studied. PMID:15812029

  16. Investigation of ecological parameters of four-stroke SI engine, with pneumatic fuel injection system

    NASA Astrophysics Data System (ADS)

    Marek, W.; Śliwiński, K.

    2016-09-01

    The publication presents the results of tests to determine the impact of using waste fuels, alcohol, to power the engine, on the ecological parameters of the combustion engine. Alternatively fuelled with a mixture of iso- and n-butanol, indicated with "X" and "END, and gasoline and a mixture of fuel and alcohol. The object of the study was a four-stroke engine with spark ignition designed to work with a generator. Motor power was held by the modified system of pneumatic injection using hot exhaust gases developed by Prof. Stanislaw Jarnuszkiewicz, controlled by modern mechatronic systems. Tests were conducted at a constant speed for the intended use of the engine. The subject of the research was to determine the control parameters such as ignition timing, mixture composition and the degree of exhaust gas recirculation on the ecological parameters of the engine. Tests were carried out using partially quality power control. In summary we present the findings of this phase of the study.

  17. Linking Genomics and Ecology to Investigate the Complex Evolution of an Invasive Drosophila Pest

    PubMed Central

    Ometto, Lino; Cestaro, Alessandro; Ramasamy, Sukanya; Grassi, Alberto; Revadi, Santosh; Siozios, Stefanos; Moretto, Marco; Fontana, Paolo; Varotto, Claudio; Pisani, Davide; Dekker, Teun; Wrobel, Nicola; Viola, Roberto; Pertot, Ilaria; Cavalieri, Duccio; Blaxter, Mark; Anfora, Gianfranco; Rota-Stabelli, Omar

    2013-01-01

    Drosophilid fruit flies have provided science with striking cases of behavioral adaptation and genetic innovation. A recent example is the invasive pest Drosophila suzukii, which, unlike most other Drosophila, lays eggs and feeds on undamaged, ripening fruits. This not only poses a serious threat for fruit cultivation but also offers an interesting model to study evolution of behavioral innovation. We developed genome and transcriptome resources for D. suzukii. Coupling analyses of these data with field observations, we propose a hypothesis of the origin of its peculiar ecology. Using nuclear and mitochondrial phylogenetic analyses, we confirm its Asian origin and reveal a surprising sister relationship between the eugracilis and the melanogaster subgroups. Although the D. suzukii genome is comparable in size and repeat content to other Drosophila species, it has the lowest nucleotide substitution rate among the species analyzed in this study. This finding is compatible with the overwintering diapause of D. suzukii, which results in a reduced number of generations per year compared with its sister species. Genome-scale relaxed clock analyses support a late Miocene origin of D. suzukii, concomitant with paleogeological and climatic conditions that suggest an adaptation to temperate montane forests, a hypothesis confirmed by field trapping. We propose a causal link between the ecological adaptations of D. suzukii in its native habitat and its invasive success in Europe and North America. PMID:23501831

  18. PROJECTING POPULATION-LEVEL RESPONSE OF PURPLE SEA URCHINS TO LEAD CONTAMINATION FOR AN ESTUARINE ECOLOGICAL RISK ASSESSMENT

    EPA Science Inventory

    As part of an ecological risk assessment case study at the Portsmouth naval Shipyard (PNS), Kittery, Maine, USA, the population level effects of lead exposure to purple sea urchin, Arbacia punctulata, were investigated using a stage-classified matrix population model. The model d...

  19. Effects of pyrite sludge pollution on soil enzyme activities: ecological dose-response model.

    PubMed

    Hinojosa, M Belén; Carreira, José A; Rodríguez-Maroto, José M; García-Ruíz, Roberto

    2008-06-25

    A laboratory study was conducted to evaluate the response of soil enzyme activities (acid and alkaline phosphatase, beta-glucosidase, arylsulfatase, urease and dehydrogenase) to different levels of trace elements pollution in soils representative of the area affected by the pyrite sludge mining spill of Aznalcóllar (Guadiamar basin, SW Spain). Three uncontaminated soils from the study area were mixed with different loads of pyrite sludge to resemble field conditions and criteria applied for reclamation practices following the pollution incident: 0% ("reference" or background level), 1.3% ("attention level", further monitoring required), 4% ("intervention level", further cleaning and liming required) and 13% (ten times the "attention level"). Enzyme activities were analysed 4, 7, 14, 21, 34 and 92 days after pollutant addition and those measured after 92 days were used to calculate the ecological dose value (ED50). Soil enzyme activities and pH decreased after the pyrite sludge addition with respect to the "reference level" (0% pyrite sludge), whereas soil bioavailable (DTPA-extractable) trace elements concentration increased. Arylsulfatase, beta-glucosidase and phosphatase activities were reduced by more than 50% at 1.3% pyrite sludge dose. Arylsulfasate was the most sensitive soil enzyme (in average, ED50=0.99), whereas urease activity showed the lowest inhibition (in average, ED50=7.87) after pyrite sludge addition. Our results showed that the ecological dose concept, applied to enzyme activities, was satisfactory to quantify the effect of a multi-metalic pollutant (pyrite sludge) on soil functionality, and would provide manageable data to establish permissible limits of trace elements in polluted soils. Additionally, we evaluate the recovery of enzyme activities after addition of sugar-beet lime (calcium carbonate) to each experimentally polluted soil. The amount of lime added to each soil was enough to raise the pH to the original value (equal to control soil

  20. Mesoscale disturbance and ecological response to decadal climatic variability in the American Southwest

    USGS Publications Warehouse

    Swetnam, T.W.; Betancourt, J.L.

    1998-01-01

    Ecological responses to climatic variability in the Southwest include regionally synchronized fires, insect outbreaks, and pulses in tree demography (births and deaths). Multicentury, tree-ring reconstructions of drought, disturbance history, and tree demography reveal climatic effects across scales, from annual to decadal, and from local (<102 km2) to mesoscale (104-106 km2). Climate-disturbance relations are more variable and complex than previously assumed. During the past three centuries, mesoscale outbreaks of the western spruce budworm (Choristoneura occidentalis) were associated with wet, not dry episodes, contrary to conventional wisdom. Regional fires occur during extreme droughts but, in some ecosystems, antecedent wet conditions play a secondary role by regulating accumulation of fuels. Interdecadal changes in fire-climate associations parallel other evidence for shifts in the frequency or amplitude of the Southern Oscillation (SO) during the past three centuries. High interannual, fire-climate correlations (r = 0.7 to 0.9) during specific decades (i.e., circa 1740-80 and 1830-60) reflect periods of high amplitude in the SO and rapid switching from extreme wet to dry years in the Southwest, thereby entraining fire occurrence across the region. Weak correlations from 1780 to 1830 correspond with a decrease in SO frequency or amplitude inferred from independent tree-ring width, ice core, and coral isotope reconstructions. Episodic dry and wet episodes have altered age structures and species composition of woodland and conifer forests. The scarcity of old, living conifers established before circa 1600 suggests that the extreme drought of 1575-95 had pervasive effects on tree populations. The most extreme drought of the past 400 years occurred in the mid-twentieth century (1942-57). This drought resulted in broadscale plant dieoffs in shrublands, woodlands, and forests and accelerated shrub invasion of grasslands. Drought conditions were broken by the post

  1. Coarse-scale spatial and ecological analysis of tuberculosis in cattle: an investigation in Jalisco, Mexico.

    PubMed

    Zendejas-Martínez, Horacio; Townsend Peterson, A; Milián-Suazo, Feliciano

    2008-11-01

    We have tested the hypothesis that coarse-scale environmental features are associated with spatial variation in bovine tuberculosis (BTB) prevalence, based on extensive sampling and testing of cattle in the state of Jalisco, Mexico. Ecological niche models were developed to summarize relationships between BTB occurrences and aspects of climate, topography and surface. Model predictions, however, reflected the distributions of dairy cattle versus beef cattle, and the non-random nature of sampling any cattle, but did not succeed in detecting environmental correlates at spatial resolutions of 1 km. Given that the tests employed seek any predictivity better than random expectations, making the finding of no environmental associations conservative, we conclude that BTB prevalence is independent of coarsescale environmental features.

  2. Conflicts over host manipulation between different parasites and pathogens: Investigating the ecological and medical consequences

    PubMed Central

    2016-01-01

    When parasites have different interests in regard to how their host should behave this can result in a conflict over host manipulation, i.e. parasite induced changes in host behaviour that enhance parasite fitness. Such a conflict can result in the alteration, or even complete suppression, of one parasite's host manipulation. Many parasites, and probably also symbionts and commensals, have the ability to manipulate the behaviour of their host. Non‐manipulating parasites should also have an interest in host behaviour. Given the frequency of multiple parasite infections in nature, potential conflicts of interest over host behaviour and manipulation may be common. This review summarizes the evidence on how parasites can alter other parasite's host manipulation. Host manipulation can have important ecological and medical consequences. I speculate on how a conflict over host manipulation could alter these consequences and potentially offer a new avenue of research to ameliorate harmful consequences of host manipulation. PMID:27510821

  3. Conflicts over host manipulation between different parasites and pathogens: Investigating the ecological and medical consequences.

    PubMed

    Hafer, Nina

    2016-10-01

    When parasites have different interests in regard to how their host should behave this can result in a conflict over host manipulation, i.e. parasite induced changes in host behaviour that enhance parasite fitness. Such a conflict can result in the alteration, or even complete suppression, of one parasite's host manipulation. Many parasites, and probably also symbionts and commensals, have the ability to manipulate the behaviour of their host. Non-manipulating parasites should also have an interest in host behaviour. Given the frequency of multiple parasite infections in nature, potential conflicts of interest over host behaviour and manipulation may be common. This review summarizes the evidence on how parasites can alter other parasite's host manipulation. Host manipulation can have important ecological and medical consequences. I speculate on how a conflict over host manipulation could alter these consequences and potentially offer a new avenue of research to ameliorate harmful consequences of host manipulation.

  4. Seasonally chemical hydrology and ecological responses in frontal zone of the central southern Yellow Sea

    NASA Astrophysics Data System (ADS)

    Wei, Qin-Sheng; Li, Xian-Sen; Wang, Bao-Dong; Fu, Ming-Zhu; Ge, Ren-Feng; Yu, Zhi-Gang

    2016-06-01

    Based on annual-cycle survey data collected in 2006-2007 in the southern Yellow Sea (SYS) and analyses on the seasonally chemical hydrologic characteristics of the boundary front of the Yellow Sea Cold Water Mass (YSCWM) and Yellow Sea Warm Current (YSWC), the seasonal variations in upwelling along the frontal zone were determined, and the ecological impacts of the front were investigated. During the generation and dissipation of the YSCWM, the implied upwelling along its western front exhibited seasonal variation. The upwelling first shifted westward from the deep-water region to its westernmost point in summer then returned eastward. The intensity of the upwelling gradually increased from spring to summer and decreased in autumn. In spring, the existence of cold water west of the YSWC was not conducive to the reproduction of phytoplankton. Additionally, the front to the east of this cold water mass also made the western boundary of the phytoplankton bloom region in the central SYS more obvious, forming a prominent chlorophyll a (Chl-a) front. During the entire stratified season (summer and autumn), the upwelling in the frontal zone of the YSCWM played an essential role in maintaining the relatively high concentrations of Chl-a. In winter, the front that formed at the intersection of the YSWC and coastal cold water was also favorable for the formation of the high-Chl-a region. The distribution of anchovy biomass was closely related to the seasonal variations in the position of the frontal zone. In winter and spring, the tongue-shaped warm water and front associated with the intrusion of the YSWC into the SYS had a significant impact on anchovy. During the stratified season in summer and autumn, the development of a front near the boundary of the YSCWM was an important physical driving mechanism for the dense distribution of anchovy. This work enhanced the study of the seasonal relationships between the physical, chemical and biological processes in the frontal

  5. Critical Aspects of the Coastal Drought Index: Length of Salinity Data Record and Ecological Response Data

    NASA Astrophysics Data System (ADS)

    Conrads, P. A.; Tufford, D. L.; Darby, L. S.

    2015-12-01

    The phenomenon of coastal drought has a different dynamic from upland droughts that are typically characterized by agricultural, hydrologic, meteorological, and(or) socio-economic impacts. Because of the uniqueness of drought impacts on coastal ecosystems, a coastal drought index (CDI) that uses existing salinity datasets for sites in South Carolina, Georgia, and Florida was developed using an approach similar to the Standardized Precipitation Index (SPI). CDIs characterizing the 1- to 24-month salinity conditions were developed and the evaluation of the CDI indicates that the index can be used for different estuary types (for example, brackish, olioghaline, or mesohaline), for regional comparison between estuaries, and as an index for wet conditions (high freshwater inflow) in addition to drought conditions. Unlike the SPI where long-term precipitation datasets of 50 to 100 years are available for computing the index, there are a limited number of salinity data sets of greater than 10 or 15 years for computing the CDI. To evaluate the length of salinity record necessary to compute the CDI, a 29-year dataset was resampled into 5-, 10-, 15-, and 20-year interval datasets. Comparison of the CDI for the different periods of record show that the range of salinity conditions in the 10-, 15-, and 20-year datasets were similar and results were a close approximation to the CDI computed by using the full period of record. The CDI computed with the 5-year dataset had the largest differences with the CDI computed with the 29-year dataset but did provide useful information on coastal drought and freshwater conditions. An ongoing National Integrated Drought Information System (NIDIS) drought early warning project in the Carolinas is developing ecological linkages to the CDI and evaluating the effectiveness of the CDI as a prediction tool for adaptation planning for future droughts. However, identifying potential coastal drought response datasets is a challenge. Coastal drought

  6. An Overview of Stream Ecological Responses to Urban Effects and Management Practices in New England

    EPA Science Inventory

    Many recent studies have found large changes in ecological conditions related to small increases in watershed development. Future development and restoration practices will benefit from better documenting the effectiveness of management practices. We present (1) a brief summary o...

  7. Control of the annual cycle in birds: endocrine constraints and plasticity in response to ecological variability.

    PubMed

    Dawson, Alistair

    2008-05-12

    This paper reviews information from ecological and physiological studies to assess how extrinsic factors can modulate intrinsic physiological processes. The annual cycle of birds is made up of a sequence of life-history stages: breeding, moult and migration. Each stage has evolved to occur at the optimum time and to last for the whole duration of time available. Some species have predictable breeding seasons, others are more flexible and some breed opportunistically in response to unpredictable food availability. Photoperiod is the principal environmental cue used to time each stage, allowing birds to adapt their physiology in advance of predictable environmental changes. Physiological (neuroendocrine and endocrine) plasticity allows non-photoperiodic cues to modulate timing to enable individuals to cope with, and benefit from, short-term environmental variability. Although the timing and duration of the period of full gonadal maturation is principally controlled by photoperiod, non-photoperiodic cues, such as temperature, rainfall or food availability, could potentially modulate the exact time of breeding either by fine-tuning the time of egg-laying within the period of full gonadal maturity or, more fundamentally, by modulating gonadal maturation and/or regression. The timing of gonadal regression affects the time of the start of moult, which in turn may affect the duration of the moult. There are many areas of uncertainty. Future integrated studies are required to assess the scope for flexibility in life-history strategies as this will have a critical bearing on whether birds can adapt sufficiently rapidly to anthropogenic environmental changes, in particular climate change.

  8. Materials and Coatings for Extreme Performances: Investigations, Applications, Ecologically Safe Technologies for Their Production and Utilization

    DTIC Science & Technology

    2004-11-16

    disordered tissue that gives rise to the broaden peak shown in Fig. 1. The TiN nano- scaled grains are responsible for the second peak. Thus, one can...0.2 to 1.4 N were used in tests. To avoid responsibility as to inaccuracies, which can occur due to the influence of scale factor, coatings were...less expensive dusted powders. III. Application of ferromagnetic powder for mill scale removal New area of steel and cast iron powder

  9. Do Young and Old Preschoolers Exhibit Response Bias Due to Different Mechanisms? Investigating Children's Response Time

    ERIC Educational Resources Information Center

    Okanda, Mako; Itakura, Shoji

    2011-01-01

    Previous studies have suggested that younger preschoolers exhibit a yes bias due to underdeveloped cognitive abilities, whereas older preschoolers exhibit a response bias due to other factors. To test this hypothesis, we investigated the response latency to yes-no questions pertaining to familiar and unfamiliar objects in 3- to 6-year-olds. The…

  10. Mesoscale Disturbance and Ecological Response to Decadal Climatic Variability in the American Southwest.

    NASA Astrophysics Data System (ADS)

    Swetnam, Thomas W.; Betancourt, Julio L.

    1998-12-01

    Ecological responses to climatic variability in the Southwest include regionally synchronized fires, insect outbreaks, and pulses in tree demography (births and deaths). Multicentury, tree-ring reconstructions of drought, disturbance history, and tree demography reveal climatic effects across scales, from annual to decadal, and from local (<102 km2) to mesoscale (104-106 km2). Climate-disturbance relations are more variable and complex than previously assumed. During the past three centuries, mesoscale outbreaks of the western spruce budworm (Choristoneura occidentalis) were associated with wet, not dry episodes, contrary to conventional wisdom. Regional fires occur during extreme droughts but, in some ecosystems, antecedent wet conditions play a secondary role by regulating accumulation of fuels. Interdecadal changes in fire-climate associations parallel other evidence for shifts in the frequency or amplitude of the Southern Oscillation (SO) during the past three centuries. High interannual, fire-climate correlations (r = 0.7 to 0.9) during specific decades (i.e., circa 1740-80 and 1830-60) reflect periods of high amplitude in the SO and rapid switching from extreme wet to dry years in the Southwest, thereby entraining fire occurrence across the region. Weak correlations from 1780 to 1830 correspond with a decrease in SO frequency or amplitude inferred from independent tree-ring width, ice core, and coral isotope reconstructions.Episodic dry and wet episodes have altered age structures and species composition of woodland and conifer forests. The scarcity of old, living conifers established before circa 1600 suggests that the extreme drought of 1575-95 had pervasive effects on tree populations. The most extreme drought of the past 400 years occurred in the mid-twentieth century (1942-57). This drought resulted in broadscale plant dieoffs in shrublands, woodlands, and forests and accelerated shrub invasion of grasslands. Drought conditions were broken by the post

  11. Connecting Urban Youth with their Environment: The Impact of an Urban Ecology Course on Student Content Knowledge, Environmental Attitudes and Responsible Behaviors

    NASA Astrophysics Data System (ADS)

    Hashimoto-Martell, Erin A.; McNeill, Katherine L.; Hoffman, Emily M.

    2012-10-01

    This study explores the impact of an urban ecology program on participating middle school students' understanding of science and pro-environmental attitudes and behaviors. We gathered pre and post survey data from four classes and found significant gains in scientific knowledge, but no significant changes in student beliefs regarding the environment. We interviewed 12 students to better understand their beliefs. Although student responses showed they had learned discrete content knowledge, they lacked any ecological understanding of the environment and had mixed perceptions of the course's relevance in their lives. Students reported doing pro-environmental behaviors, but overwhelmingly contributed such actions to influences other than the urban ecology course. Analyses indicated a disconnect between the course, the environment, and the impact on the students' lives. Consequently, this suggests the importance of recognizing the implications of context, culture, and identity development of urban youth. Perhaps by providing explicit connections and skills in urban environmental programs through engaging students in environmental scientific investigations that stem from their own issues and questions can increase student engagement, motivation, and self-efficacy of environmental issues.

  12. WAG 2 remedial investigation and site investigation site-specific work plan/health and safety checklist for the ecological assessment task, Kingfisher Study

    SciTech Connect

    Holt, V.L.; Baron, L.A.

    1994-05-01

    This report provides specific details and requirements for the WAG 2 remedial investigation and site investigation Ecological Assessment Task, Kingfisher Study, including information that will contribute to safe completion of the project. The report includes historical background; a site map; project organization; task descriptions and hazard evaluations; controls; and monitoring, personal protective equipment, decontamination, and medical surveillance program requirements. The report also includes descriptions of site personnel and their certifications as well as suspected WAG 2 contaminants and their characteristics. The primary objective of the WAG 2 Kingfisher Study is to assess the feasibility of using kingfishers as biological monitors of contaminants on the Oak Ridge Reservation (ORR). Kingfisher sample collection will be used to determine the levels of contaminants and degree of bioaccumulation within a common piscivorous bird feeding on contaminated fish from streams on the ORR.

  13. Ecology of plague in Africa: response of indigenous wild rodents to experimental plague infection

    PubMed Central

    Isaäcson, Margaretha; Taylor, Paul; Arntzen, Lorraine

    1983-01-01

    The Mastomys natalensis species complex, subdivided into genetically distinct species having diploid chromosome numbers 2n = 32 and 2n = 36, is a reservoir for several zoonoses including Lassa fever and plague. This report describes a study to determine whether these sibling species and three other rodent species have different potential as reservoirs for plague. It was found that M. natalensis (2n = 32) was significantly more resistant to experimental plague infection (50% survived inoculation with 120 000 Yersinia pseudotuberculosis subsp. pestis) than was M. coucha (2n = 36) (none of which survived doses of 190 Y. pseudotuberculosis subsp.pestis). In descending order of resistance were M. natalensis, Aethomys chrysophilus, M. coucha, Tatera leucogaster and A. namaquensis. No A. namaquensis survived inoculation of 10 or more plague bacilli. Previous reports on susceptibility to plague or other infections, which were based exclusively on findings in the universally distributed laboratory-bred Mastomys, are thus not necessarily applicable to the M. natalensis species as a whole but probably only to M. coucha. The Y. pseudotuberculosis subsp. pestis fraction-1 passive haemagglutination test appeared to be relatively insensitive in that only 5 out of 47 animals surviving experimental plague infection showed specific antibodies 6 weeks after challenge. The geographic distribution of human plague in southern Africa corresponds closely with that of the plague-susceptible species, M. coucha, while the resistant species, M. natalensis, predominates in areas where human plague has not been recorded. The role of A. namaquensis in the ecology of plague needs to be carefully studied and its possible importance in plague research should be investigated further. PMID:6345015

  14. Ecology of plague in Africa: response of indigenous wild rodents to experimental plague infection.

    PubMed

    Isaäcson, M; Taylor, P; Arntzen, L

    1983-01-01

    The Mastomys natalensis species complex, subdivided into genetically distinct species having diploid chromosome numbers 2n = 32 and 2n = 36, is a reservoir for several zoonoses including Lassa fever and plague. This report describes a study to determine whether these sibling species and three other rodent species have different potential as reservoirs for plague. It was found that M. natalensis (2n = 32) was significantly more resistant to experimental plague infection (50% survived inoculation with 120 000 Yersinia pseudotuberculosis subsp. pestis) than was M. coucha (2n = 36) (none of which survived doses of 190 Y. pseudotuberculosis subsp.pestis). In descending order of resistance were M. natalensis, Aethomys chrysophilus, M. coucha, Tatera leucogaster and A. namaquensis. No A. namaquensis survived inoculation of 10 or more plague bacilli.Previous reports on susceptibility to plague or other infections, which were based exclusively on findings in the universally distributed laboratory-bred Mastomys, are thus not necessarily applicable to the M. natalensis species as a whole but probably only to M. coucha. The Y. pseudotuberculosis subsp. pestis fraction-1 passive haemagglutination test appeared to be relatively insensitive in that only 5 out of 47 animals surviving experimental plague infection showed specific antibodies 6 weeks after challenge.The geographic distribution of human plague in southern Africa corresponds closely with that of the plague-susceptible species, M. coucha, while the resistant species, M. natalensis, predominates in areas where human plague has not been recorded. The role of A. namaquensis in the ecology of plague needs to be carefully studied and its possible importance in plague research should be investigated further.

  15. Animal behaviour shapes the ecological effects of ocean acidification and warming: moving from individual to community-level responses.

    PubMed

    Nagelkerken, Ivan; Munday, Philip L

    2016-03-01

    Biological communities are shaped by complex interactions between organisms and their environment as well as interactions with other species. Humans are rapidly changing the marine environment through increasing greenhouse gas emissions, resulting in ocean warming and acidification. The first response by animals to environmental change is predominantly through modification of their behaviour, which in turn affects species interactions and ecological processes. Yet, many climate change studies ignore animal behaviour. Furthermore, our current knowledge of how global change alters animal behaviour is mostly restricted to single species, life phases and stressors, leading to an incomplete view of how coinciding climate stressors can affect the ecological interactions that structure biological communities. Here, we first review studies on the effects of warming and acidification on the behaviour of marine animals. We demonstrate how pervasive the effects of global change are on a wide range of critical behaviours that determine the persistence of species and their success in ecological communities. We then evaluate several approaches to studying the ecological effects of warming and acidification, and identify knowledge gaps that need to be filled, to better understand how global change will affect marine populations and communities through altered animal behaviours. Our review provides a synthesis of the far-reaching consequences that behavioural changes could have for marine ecosystems in a rapidly changing environment. Without considering the pervasive effects of climate change on animal behaviour we will limit our ability to forecast the impacts of ocean change and provide insights that can aid management strategies.

  16. 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.

  17. A review of fire effects on vegetation and soils in the Great Basin region: response and ecological site characteristics

    USGS Publications Warehouse

    Miller, Richard F.; Chambers, Jeanne C.; Pyke, David A.; Pierson, Fred B.; Williams, C. Jason

    2013-01-01

    This review synthesizes the state of knowledge on fire effects on vegetation and soils in semi-arid ecosystems in the Great Basin Region, including the central and northern Great Basin and Range, Columbia River Basin, and the Snake River Plain. We summarize available literature related to: (1) the effects of environmental gradients, ecological site, and vegetation characteristics on resilience to disturbance and resistance to invasive species; (2) the effects of fire on individual plant species and communities, biological soil crusts, seed banks, soil nutrients, and hydrology; and (3) the role of fire severity, fire versus fire surrogate treatments, and post-fire grazing in determining ecosystem response. From this, we identify knowledge gaps and present a framework for predicting plant successional trajectories following wild and prescribed fires and fire surrogate treatments. Possibly the three most important ecological site characteristics that influence a site’s resilience (ability of the ecological site to recover from disturbance) and resistance to invasive species are soil temperature/moisture regimes and the composition and structure of vegetation on the ecological site just prior to the disturbance event.

  18. Considerations of Scale and Processes in Stream Restoration and Ecological Response

    NASA Astrophysics Data System (ADS)

    Simon, A.; Shields, D.; Kuhnle, R.; Knight, S.

    2005-12-01

    Stream restoration as a means of controlling accelerated channel erosion and improving biological function in streams has become pervasive in the United States over the past twenty years. A broad range of practices often involving direct modifications to stream channels and adjacent floodplains, including alterations to morphology and pattern have been used for stream restoration. Because alluvial-channel processes and biological functioning operate as linked, open systems, any restoration project must be placed in the context of existing watershed and channel processes with a quantitative understanding of the rates of transfer of flow energy and materials. This is particularly true of reach-scale projects where local stabilization and habitat improvements may be completely overwhelmed by watershed or channel-system scale instabilities. In this regard, it is unlikely that a reach-scale project will be successful in an unstable alluvial system. This is analogous to constructing bank-stabilization measures in an actively incising channel. A conceptual model of channel response and evolution that marks systematic shifts in channel processes over time and space has been linked to fish-community structure in Mississippi streams. This link reflects changing habitat conditions and sediment-transport regimes over the course of fluvial adjustment. Suspended-sediment concentrations that can increase by orders of magnitude for a given discharge during the incision and mass-wasting phases abrade fish gills and reduce the ability of fish to hunt for food due to reduced water clarity. Similarly, durations of high suspended-sediment concentrations are shown to be inversely related to numbers of benthic macro invertebrates. Streambeds experiencing active incision (Stage III) may be too mobile for benthic macro invertebrate communities to thrive. Channels dominated by mass-wasting processes (Stages IV and V) lose riparian vegetative cover and shading which may result in higher

  19. Studying global change through investigation of the plastic responses of xylem anatomy in tree rings.

    PubMed

    Fonti, Patrick; von Arx, Georg; García-González, Ignacio; Eilmann, Britta; Sass-Klaassen, Ute; Gärtner, Holger; Eckstein, Dieter

    2010-01-01

    Variability in xylem anatomy is of interest to plant scientists because of the role water transport plays in plant performance and survival. Insights into plant adjustments to changing environmental conditions have mainly been obtained through structural and functional comparative studies between taxa or within taxa on contrasting sites or along environmental gradients. Yet, a gap exists regarding the study of hydraulic adjustments in response to environmental changes over the lifetimes of plants. In trees, dated tree-ring series are often exploited to reconstruct dynamics in ecological conditions, and recent work in which wood-anatomical variables have been used in dendrochronology has produced promising results. Environmental signals identified in water-conducting cells carry novel information reflecting changes in regional conditions and are mostly related to short, sub-annual intervals. Although the idea of investigating environmental signals through wood anatomical time series goes back to the 1960s, it is only recently that low-cost computerized image-analysis systems have enabled increased scientific output in this field. We believe that the study of tree-ring anatomy is emerging as a promising approach in tree biology and climate change research, particularly if complemented by physiological and ecological studies. This contribution presents the rationale, the potential, and the methodological challenges of this innovative approach.

  20. Preliminary investigations of the winter ecology of Long-billed Curlews in coastal Texas

    USGS Publications Warehouse

    Woodin, Marc C.; Skoruppa, Mary Kay; Edwardson, Jeremy W.; Austin, Jane E.

    2012-01-01

    Results from this 1-year pilot study yielded an intriguing combination of findings that warrant further investigation. Observations include reduced numbers of roosting birds along the Texas coast during dry conditions, highly dynamic use of nocturnal roost sites, use of widely divergent habitat types for foraging, low body mass of most captured birds, and apparent fidelity to general feeding areas. Future investigations of this eastern winter population of curlews would benefit from larger sample sizes and monitoring of individual birds.

  1. Biological And Ecological Responses Of Macrobenthic Assemblages To Sediment Contamination In French Streams

    NASA Astrophysics Data System (ADS)

    Archaimbault, V.; Garric, J.; Babut, M.; Usseglio-Polatera, P.; Wasson, J.

    2005-05-01

    In order to fit the requirements of the European Water Framework Directive, member states have to quantify the relationships between the biological status and physical and chemical properties of surface waters and to develop validated tools to assess the ecological quality of freshwater ecosystems. With the objectives 1) to describe toxic impact on in situ macrobenthic communities and 2) to identify key biological metrics for describing toxic pressures, the relationships between stream sediment toxicity (concentration of trace elements, PAHs, organochlorine compounds and pesticides) and the functional structure of macrobenthic communities were analysed. Faunal and chemical data were obtained from the French water data network and analysed by multivariate and regression approaches. Combinations of biological and ecological traits were related to faunal changes and compared to sediment contamination. Moreover, the possibility of using these results for predicting the stream ecological status as a function of chemical contamination were examined. The relevance of observed tendencies and pressure/impact relationships will be discussed.

  2. A social ecological approach to investigating relationships between housing and adaptive functioning for persons with serious mental illness.

    PubMed

    Kloos, Bret; Shah, Seema

    2009-12-01

    This paper seeks to advance mental health-housing research regarding which factors of housing and neighborhood environments are critical for adaptive functioning, health, and recovery for persons with serious mental illness (SMI). Housing and neighborhood environments are particularly important for persons with SMI because of the prevalence of poor housing conditions among this population. Most mental health-housing research has been limited by a focus on problems in environments and functioning. The paper seeks to expand the mental health-housing research agenda to consider protective factors that promote community integration and adaptive functioning. We provide an account of how social ecology theory transformed a research program, from examining individual risk factors to investigating the functioning of persons in the contexts of their housing and neighborhood experiences. The resulting housing environment framework-physical aspects of housing and neighborhoods, social environment of neighborhoods, and interpersonal relationships tied to housing-allows for identification of opportunities for health promotion and facilitation of participation in community-based settings. This program of research draws upon several methods to understand the social experience of persons with SMI living in community settings-survey research, qualitative interviews, Geographic Information Systems, participatory research, and visual ethnography. In this paper, we present how social ecology theory was instrumental in the development of new housing environment measures, the selection of appropriate research methods, and framing research questions that are building a new empirical base of knowledge about promoting adaptive functioning, health, and recovery for persons with SMI living in community settings.

  3. Molecular ecological analysis of porcine ileal microbiota responses to antimicrobial growth promoters.

    PubMed

    Collier, C T; Smiricky-Tjardes, M R; Albin, D M; Wubben, J E; Gabert, V M; Deplancke, B; Bane, D; Anderson, D B; Gaskins, H R

    2003-12-01

    Cultivation-independent microbial molecular ecology approaches were used to examine the effects of antibiotic growth promoters on the pig ileal microbiota. Five-week-old barrows were fitted with a simple T-cannula at the distal ileum. Three diets meeting or exceeding the minimum nutrient requirements were fed for 5 wk and supplemented as follows: 1) negative control (no antibiotic; n = 5), 2) continuous tylosin administration (n = 5), and 3) an antibiotic rotation sequence (wk 1, chlorotetracycline sulfathiazole penicillin; wk 2, bacitracin and roxarsone; wk 3, lincomycin; wk 4, carbadox; wk 5, virginiamycin; n = 5). Ileal luminal contents were collected for DNA isolation at the end of each of the 5 wk of the testing period. The V3 region of 16S rDNA was amplified by PCR and analyzed via denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction (qPCR). Resulting PCR-DGGE band numbers (bacterial species) were counted, and the banding patterns analyzed by calculating Sorenson's pairwise similarity coefficients (C(S)), an index measuring bacterial species in common among samples. Band numbers and total bacterial DNA concentrations decreased (P < 0.05) temporally in antibiotic-treated pigs compared with controls. Comparisons between treatments yielded low intertreatment C(S) indices, indicating treatment-dependent alterations in banding patterns, whereas intratreatment comparisons revealed increased homogeneity in antibiotic-treated vs. control pigs. Sequence analysis of treatment-specific bands identified three Lactobacillus, one Streptococcus, and one Bacillus species that were diminished with antibiotic rotation treatment, whereas tylosin selected for the presence of L. gasseri. Lactobacillus-specific qPCR was performed and analyzed as a percentage of total bacteria to further evaluate the effects of antibiotic administration on this genus. Total bacteria were decreased (P < 0.05) by tylosin and rotation treatments, whereas the

  4. Spatial and ecological variation in dryland ecohydrological responses to climate change: implications for management

    USGS Publications Warehouse

    Palmquist, Kyle A.; Schlaepfer, Daniel R.; Bradford, John B.; Lauenroth, William K.

    2016-01-01

    Ecohydrological responses to climate change will exhibit spatial variability and understanding the spatial pattern of ecological impacts is critical from a land management perspective. To quantify climate change impacts on spatial patterns of ecohydrology across shrub steppe ecosystems in North America, we asked the following question: How will climate change impacts on ecohydrology differ in magnitude and variability across climatic gradients, among three big sagebrush ecosystems (SB-Shrubland, SB-Steppe, SB-Montane), and among Sage-grouse Management Zones? We explored these potential changes for mid-century for RCP8.5 using a process-based water balance model (SOILWAT) for 898 big sagebrush sites using site- and scenario-specific inputs. We summarize changes in available soil water (ASW) and dry days, as these ecohydrological variables may be helpful in guiding land management decisions about where to geographically concentrate climate change mitigation and adaptation resources. Our results suggest that during spring, soils will be wetter in the future across the western United States, while soils will be drier in the summer. The magnitude of those predictions differed depending on geographic position and the ecosystem in question: Larger increases in mean daily spring ASW were expected for high-elevation SB-Montane sites and the eastern and central portions of our study area. The largest decreases in mean daily summer ASW were projected for warm, dry, mid-elevation SB-Montane sites in the central and west-central portions of our study area (decreases of up to 50%). Consistent with declining summer ASW, the number of dry days was projected to increase rangewide, but particularly for SB-Montane and SB-Steppe sites in the eastern and northern regions. Collectively, these results suggest that most sites will be drier in the future during the summer, but changes were especially large for mid- to high-elevation sites in the northern half of our study area. Drier

  5. Evidence for a hormonal tactic maximizing green turtle reproduction in response to a pervasive ecological stressor.

    PubMed

    Jessop, T S; Hamann, M; Read, M A; Limpus, C J

    2000-06-01

    Mortality of breeding sea turtles due to excessive heat exposure after nesting activities is an unusual feature of the Raine Island green turtle rookery. Breeding turtles that fail to return to the ocean after oviposition can experience increasing body temperatures that exceed lethal limits (>39 degrees C) as ambient temperatures rise after sunrise. We investigated how acute increases in body temperature influenced plasma corticosterone (B) concentrations of individual turtles. Furthermore, interactions between progesterone (P) and testosterone (T) and increasing body temperature and the glucocorticoid corticosterone were examined for negative correlations. Breeding green turtles exhibited a 16-fold mean increase in plasma corticosterone concentration as body temperature (cloacal) rose from 28.2 to 40.7 degrees C in less than 6 h. However, the absolute increase in plasma B was small and much less than expected, despite the lethal stressor. Comparatively, the maximal B response to lethal heat stress was similar to plasma B concentrations obtained from breeding female turtles exposed to 8 h of capture stress. However, the maximal B response of breeding turtles exposed to heat and capture stressors was significantly less than the B response of nonbreeding adult female turtles subjected to an 8-h capture stressor. No negative correlations were observed between plasma T and plasma B, between plasma T and body temperature, between plasma P and plasma B, or between plasma P and body temperature. Our findings provide further evidence that reduced adrenocortical function operates in breeding green turtles in the presence of even the most pervasive of environmental stressors.

  6. Investigating the nonlinear microbubble response to chirp encoded, multipulse sequences.

    PubMed

    Chetty, Kevin; Hajnal, Joseph V; Eckersley, Robert J

    2006-12-01

    A modified Rayleigh-Plesset model was used to investigate the nonlinear acoustic response of ultrasound contrast microbubbles to multipulse phase and amplitude modulated, chirp encoded sequences. Trade-offs between the signal-to-noise ratio (SNR) and axial resolution were quantified for differing chirp time-bandwidth products and methods for minimising the artifacts formed in the postprocessing stages were developed. It was found that the chirp length can be increased and bandwidth reduced to improve SNR, though resolution is sacrificed. Results from the simulated chirp, pulse inverted, amplitude modulated (chirp PIAM) sequences were also compared with equivalent short pulse PIAM sequences and it was found that the chirp sequences preserve their extra energy after scattering, which translates to an improved SNR after processing. Compression artifacts were reduced by using chirps with a centre frequency and bandwidth tuned to the frequency response of the microbubble and reversing the frequency sweep of one chirp in the sequence.

  7. Response to June Boyce-Tillman, "Towards an Ecology of Music Education"

    ERIC Educational Resources Information Center

    Garberich, Mark

    2004-01-01

    Mark Garberich responds to June Boyce-Tillman's "Towards an Ecology of Music Education," by saying that it challenges the foundations of music education philosophy and its application to practice. Garberich believes that beginning with the identification and clarification of what are described as "subjugated ways of knowing," she advocates the…

  8. Long-Term Trends in Ecological Systems: A Basis for Understanding Responses to Global Change

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Eco Trends Editorial Committee sorted through vast amounts of historical and ongoing data from 50 ecological sites in the continental United States including Alaska, several islands, and Antarctica to present in a logical format the variables commonly collected. This report presents a subset of...

  9. Ecological responses to simulated agricultural runoff in a riverine backwater wetland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Riverine backwater wetlands within river floodplains provide valuable ecological functions such as acting as filters for suspended sediment, nutrients and pesticides entering from adjacent agricultural fields, as well as habitat and refugia for aquatic biota. A 500 m long, 20 m wide riverine backwa...

  10. Ecological catastrophes: threshold responses to climate, soil, and land use drivers of the dust bowl

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Dust Bowl was one of the largest ecological disasters, yet is among the least well-studied for regional-scale impacts. Much of the central grasslands region (CGR) of North America experienced a multi-year drought in the 1930s that combined with poor land management practices to result in broad-s...

  11. Responsive Classroom Ecologies: Supporting Student Inquiry and Rhetorical Awareness in College Writing Courses

    ERIC Educational Resources Information Center

    Jankens, Adrienne

    2014-01-01

    This dissertation describes and analyzes the work of a semester-long teacher research study of inquiry-based and reflective teaching and learning strategies and their impact on students' preparation for future learning. I explore relevant scholarship on knowledge transfer, classroom ecologies, and student agency to set the stage for a discussion…

  12. Tallgrass prairie ants: their species composition, ecological roles, and response to management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ants are highly influential organisms in terrestrial ecosystems, including the tallgrass prairie, one of the most endangered ecosystems in North America. Through their tunneling, ants affect soil properties and resource availability for animals and plants. Ants also have important ecological roles a...

  13. Fishery and Ecological Investigations of Main Stem Levee Borrow Pits Along the Lower Mississippi River.

    DTIC Science & Technology

    1984-12-01

    the use of such commercial products. - ’ % : -4. -4 -. Uncl aifid SECURITY CLASSIFICATION OF THIS PAGE (When Dae Entered) _L__ _ _ READ ...LNREP. The investigation was conducted under the direction of the President of the Mississippi River Commission, MG William E. Read , CE. CONES MPAT I... readings (±0.l m) were taken at each of the sampling stations. 25. 8enthi a invertratma. Two 0.023-si2 samples were collected at each station using a

  14. Investigation of the factors responsible for burns during MRI.

    PubMed

    Dempsey, M F; Condon, B; Hadley, D M

    2001-04-01

    Numerous reported burn injuries have been sustained during clinical MRI procedures. The aim of this study was to investigate the possible factors that may be responsible for such burns. Experiments were performed to investigate three possible mechanisms for causing heating in copper wire during MRI: direct electromagnetic induction in a conductive loop, induction in a resonant conducting loop, and electric field resonant coupling with a wire (the antenna effect). Maximum recorded temperature rises were 0.6 degrees C for the loop, 61.1 degrees C for the resonant loop, and 63.5 degrees C for the resonant antenna. These experimental findings suggest that, contrary to common belief, it is unlikely that direct induction in a conductive loop will result in thermal injury. Burn incidents are more likely to occur due to the formation of resonant conducting loops and from extended wires forming resonant antenna. The characteristics of resonance should be considered when formulating safety guidelines.

  15. Investigation of wheat coleoptile response to phototropic stimulations

    NASA Technical Reports Server (NTRS)

    Heathcote, David G.; Brown, Allen H.; Chapman, David K.

    1993-01-01

    This report provides a summary of the preparations for, and the conduct and post-flight data analysis of, the Spacelab flight investigation FOTRAN, which flew on the IML-1 mission (STS-42) in January, 1992. The investigation was designed to provide data on the responses of wheat seedlings to various blue-light stimuli given while the plants were exposed to orbital microgravity conditions. Before the flight, a number of hypotheses were established which were to be tested by the data from the flight and parallel ground studies. A description of the experiment protocol developed for the mission is provided, and an account of the activities supported during preparations for and support of the flight experiment is given. Details of the methods used to reduce and analyze the data from the flight are outlined.

  16. 77 FR 69631 - Draft Guidance for IRBs, Clinical Investigators, and Sponsors: IRB Responsibilities for Reviewing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ... Responsibilities for Reviewing the Qualifications of Investigators, Adequacy of Research Sites, and the... of investigators, adequacy of research sites, and the determination of whether an investigational new... Responsibilities for Reviewing the Qualifications of Investigators, Adequacy of Research Sites, and...

  17. Empathic responses to others' gains and losses: an electrophysiological investigation.

    PubMed

    Ma, Qingguo; Shen, Qiang; Xu, Qing; Li, Diandian; Shu, Liangchao; Weber, Bernd

    2011-02-01

    A growing number of studies in exploring empathic modulation have revealed the neural substrates of how social stimuli are represented in the human brain, especially the pain of others. The empathic response of observing other's gains and losses, however, remains not clearly characterized. In the current study, we carried out two experiments with a gamble task to investigate how the effects of interpersonal familiarity and self-participation work on modulating the temporal neural response towards gain and loss of a friend or a stranger using scalp-recorded event-related potentials (ERPs). The electrophysiological data show an increased amplitude of the P300 when observing a friend's performance compared to strangers playing the game in both two experiments. But the distinction of differentiated feedback-related negativity (d-FRN) between friends and strangers was only observed when the player was not involved in the game. These results indicated that the participants exerted more motivational relevance toward their friends than strangers, but the participants' empathic response toward friends was only salient when they were not involved in the gamble directly. Therefore, both familiarity and self-engagement are factors that influence the empathy towards others, complementing the recent research on empathic modulation.

  18. A PERSON-CENTERED AND ECOLOGICAL INVESTIGATION OF ACCULTURATION STRATEGIES IN HISPANIC IMMIGRANT YOUTH.

    PubMed

    Coatsworth, J Douglas; Maldonado-Molina, Mildred; Pantin, Hilda; Szapocznik, José

    2005-03-01

    Understanding the processes of acculturation in ethnic minority populations is one of the central tasks of crosscultural research. Addressing challenges of theory, methods, and application in acculturation research requires ongoing advancements in methods and theoretical and model development. The current study was designed to explain a person-centered approach to investigating acculturation and biculturalism and to illustrate this method with a sample of 315 Hispanic youth. Pattern analyses of the Hispanicism and Americanism scores from the Bicultural Involvement Scale yielded four distinct acculturation types, including one characterized by moderate scores on both scales. Relations between acculturation types and indicators of individual, family, and peer adaptation were tested. Results indicated that bicultural youth tended to show the most adaptive pattern of functioning across multiple sociocultural domains. Assimilated youth did not show as strongly negative a pattern as has been reported elsewhere. Implications and benefits of a person-centered approach are discussed.

  19. A PERSON-CENTERED AND ECOLOGICAL INVESTIGATION OF ACCULTURATION STRATEGIES IN HISPANIC IMMIGRANT YOUTH

    PubMed Central

    Coatsworth, J. Douglas; Maldonado-Molina, Mildred; Pantin, Hilda; Szapocznik, José

    2006-01-01

    Understanding the processes of acculturation in ethnic minority populations is one of the central tasks of crosscultural research. Addressing challenges of theory, methods, and application in acculturation research requires ongoing advancements in methods and theoretical and model development. The current study was designed to explain a person-centered approach to investigating acculturation and biculturalism and to illustrate this method with a sample of 315 Hispanic youth. Pattern analyses of the Hispanicism and Americanism scores from the Bicultural Involvement Scale yielded four distinct acculturation types, including one characterized by moderate scores on both scales. Relations between acculturation types and indicators of individual, family, and peer adaptation were tested. Results indicated that bicultural youth tended to show the most adaptive pattern of functioning across multiple sociocultural domains. Assimilated youth did not show as strongly negative a pattern as has been reported elsewhere. Implications and benefits of a person-centered approach are discussed. PMID:16799699

  20. “My Worries Are Rational, Climate Change Is Not”: Habitual Ecological Worrying Is an Adaptive Response

    PubMed Central

    Verplanken, Bas; Roy, Deborah

    2013-01-01

    Qualifications such as “global warming hysteria” and “energy policy schizophrenia” put forward by some climate change skeptics, usually outside the academic arena, may suggest that people who seriously worry about the environment suffer from psychological imbalance. The present study aimed to refute this thesis. While habitual worrying in general is strongly associated with psychopathological symptoms, in a survey a near-zero correlation was found between habitual ecological worrying and pathological worry. Instead, habitual ecological worrying was associated with pro-environmental attitudes and behaviors, and with a personality structure characterized by imagination and an appreciation for new ideas. The study had sufficient statistical power and measures were valid and reliable. The results confirm that those who habitually worry about the ecology are not only lacking in any psychopathology, but demonstrate a constructive and adaptive response to a serious problem. In the public domain, these findings may contribute to a more rational and less emotional debate on climate change and to the prevention of stigmatization of people who are genuinely concerned about our habitat and are prepared to do something about it (“habitual worriers are not crazy”). In the academic arena this study may contribute to environmental psychology (“habitual worrying is part of a green identity”), as well as to the literature on worry and anxiety (“habitual worrying can be a constructive response”). PMID:24023958

  1. Investigating the Complex Conductivity Response of Different Biofilm Components

    NASA Astrophysics Data System (ADS)

    Atekwana, E. A.; Abdel Aal, G. Z.; Sarkisova, S. A.; Patrauchan, M.

    2013-12-01

    Microbial biofilms are structured communities of microorganisms commonly attached to a surface and embedded in a self-produced matrix. The matrix is composed of extracellular polymeric substances (EPS), which commonly include extracellular DNA, proteins, and polysaccharides. In addition, the biofilm structure may contain some other components such as metabolic byproducts and biogenic nanoparticle minerals. Biogeophysical studies have demonstrated the sensitivity of spectral induced polarization (SIP) measurements to the growth and development of biofilm in saturated porous media. However, the mechanisms are not very well understood. The overarching goal of this study is to determine the contribution of the different biofilm components to the spectral induced polarization (SIP) signatures in aqueous and/or porous media. We investigated the SIP response of different biofilm components including bacterial cells, alginate (exopolysaccharide), phenazine (redox-active metabolite) and magnetite (semi-conductive particulate matter). The porous media was glass beads with grain diameter of 1 mm. Each of the biofilm components was suspended in a low salt growth medium with electrolytic conductivity of 513 μS/cm. Using Pseudomonas aeruginosa PAO1 cells in suspension and in porous media, we observed the increase in SIP parameters with increasing cell density with a very well defined relaxation peak at a frequency of ~10 Hz, which was predicted by recently developed quantitative models. However, this characteristic relaxation peak was minimized in the presence of porous media. We also observed that cells suspended in alginate enhance the polarization and show a peak frequency at ~10 Hz. The study of alginate gelation in liquid phase and porous media in vitro revealed that solidified (gelated) alginate (from brown algae) increased the magnitude of imaginary conductivity while real conductivity increased very moderately. In contrast, the study of the SIP response within a porous

  2. The natural vegetation responses to the groundwater change resulting from ecological water conveyances to the lower Tarim River.

    PubMed

    Xu, Hailiang; Ye, Mao; Song, Yudong; Chen, Yaning

    2007-08-01

    This paper takes the ecological water conveyance project (EWCP) that transfers water from the Bosten Lake, to Daxihaizi Reservoir, and finally to the Taitema Lake as a case study to analyze the dynamic change of the groundwater depth, the vegetation responses to the elevation of the groundwater depth as well as the relationship between the groundwater depth and the natural vegetation. The results from many years' monitoring in field indicate: (1) the groundwater depth has been elevating gradually with the increase in the times of watering and the elevation range has been expanding continuously in the lower reaches of Tarim River. Correspondingly, the natural vegetation has a favorable response to the elevation of the groundwater depth. The change of the natural vegetation has accordance with that of the groundwater depth. Such facts not only show that groundwater is a key factor to the growth of the native vegetation but also prove it is feasible that the degraded ecosystem can be restored and protected by the EWCP; (2) the results of analysis of the spatial-temporal response of the natural vegetation to watering reveals that the beneficial influence of the EWCP on the ecosystem in the lower Tarim River is a long-term process; (3) in terms of the function and structure of ecosystem after watering in the lower reaches of Tarim River, the EWCP does not still reach the goal of ecological restoration at a large spatial scale at present. Based on such monitoring results, some countermeasures and suggestions for the future restoration strategy are proposed so as to provide a theoretical basis for restoring and protecting the ecosystem in Tarim River, and meanwhile it can also provide some scientific references for implementing the similar ecological projects in other areas.

  3. Between Scylla and Charybdis: renegotiating resolution of the 'obstetric dilemma' in response to ecological change.

    PubMed

    Wells, Jonathan C K

    2015-03-05

    Hominin evolution saw the emergence of two traits-bipedality and encephalization-that are fundamentally linked because the fetal head must pass through the maternal pelvis at birth, a scenario termed the 'obstetric dilemma'. While adaptive explanations for bipedality and large brains address adult phenotype, it is brain and pelvic growth that are subject to the obstetric dilemma. Many contemporary populations experience substantial maternal and perinatal morbidity/mortality from obstructed labour, yet there is increasing recognition that the obstetric dilemma is not fixed and is affected by ecological change. Ecological trends may affect growth of the pelvis and offspring brain to different extents, while the two traits also differ by a generation in the timing of their exposure. Two key questions arise: how can the fit between the maternal pelvis and the offspring brain be 'renegotiated' as the environment changes, and what nutritional signals regulate this process? I argue that the potential for maternal size to change across generations precludes birthweight being under strong genetic influence. Instead, fetal growth tracks maternal phenotype, which buffers short-term ecological perturbations. Nevertheless, rapid changes in nutritional supply between generations can generate antagonistic influences on maternal and offspring traits, increasing the risk of obstructed labour.

  4. An Investigation of Cancer Rates in the Argentia Region, Newfoundland and Labrador: An Ecological Study

    PubMed Central

    Duke, Pauline; Godwin, Marshall; Peach, Mandy; Fortier, Jacqueline; Bornstein, Stephen; Buehler, Sharon; McCrate, Farah; Pike, Andrea; Wang, Peizhong Peter; Cullen, Richard M.

    2015-01-01

    Background. The Argentia region of Newfoundland and Labrador, Canada, was home to a US naval base during a 40-year period between the 1940s and the 1990s. Activities on the base resulted in contamination of the soil and groundwater in the region with chemicals such as heavy metals and dioxins, and residents have expressed concern about higher rates of cancer in their community. This study investigated the rate of cancer diagnosis that is disproportionately high in the Argentia region. Methods. Cases of cancer diagnosed between 1985 and 2011 were obtained for the Argentia region, two comparison communities, and the province of Newfoundland and Labrador. Crude and age-standardized incidence rates of cancer diagnosis were calculated and compared. The crude incidence rate was adjusted for differences in age demographics using census data, and age-standardized incidence rates were compared. Results. Although the Argentia region had a higher crude rate of cancer diagnosis, the age-standardized incidence rate did not differ significantly from the comparison communities or the provincial average. Argentia has an aging population, which may have influenced the perception of increased cancer diagnosis in the community. Conclusions. We did not detect an increased burden of cancer in the Argentia region. PMID:26633979

  5. The MICROBE (Microcosm Investigation of Carbonate Reef/Ocean Microbial Biogeochemistry & Ecology) Project

    NASA Astrophysics Data System (ADS)

    Hannides, A. K.; Gaidos, E. J.; Sansone, F. J.

    2003-12-01

    We present a methodology to manipulate carbonate reef sediments in order to study the geochemical and microbiological response of reef systems to perturbations. We specifically plan to study the effects of changes in the atmospheric partial pressure of CO2. Our laboratory set-up will consist of cores containing carbonate reef sediments and overlying water. These microcosms are designed to replicate the gross hydraulic and geochemical characteristics of sediments in a natural tropical reef patch. This is achieved by reproducing the advective transport of water and particulates in and out of the sediments induced by tides and surface waves. Seawater from nearby reefs is to be introduced into the cores with reversible peristaltic pumps. The pumps will vary the overlying water column and simulate the changes in hydrostatic head that accompany waves and tides. The parameters characterizing these oscillations will be set at values reflecting those at nearby natural settings. Sediment column characteristics will be determined non-destructively through openings at various depths down the sediment cores. These openings are fitted with rubber septa and shut-off valves, which allow gas-tight sampling of porewaters. An additional set of openings allows for the removal of small amounts of sediments using augers. Our porewater analyses will include dissolved O2, CO2, CH4 and alkalinity, ammonium, sulfide, and iron and manganese ions. Our solid phase analyses will include carbonate composition and framework structure, and iron and manganese abundances in the carbonate phases. We will measure microbial abundance in porewater and the sediment particles by DAPI cell counts and will assay community composition using Denaturing Gradient Gel Electrophoresis (DGGE). Our goal is to use this methodology to observe and record carbonate precipitation and dissolution by microbiota under varying carbon dioxide regimes. pCO2 concentrations will be manipulated by bubbling a N2/CO2 mixture

  6. Lymphohaematopoietic system cancer incidence in an urban area near a coke oven plant: an ecological investigation

    PubMed Central

    Parodi, S; Vercelli, M; Stella, A; Stagnaro, E; Valerio, F

    2003-01-01

    Aims: To evaluate the incidence risk of lymphohaematopoietic cancers for the 1986–94 period in Cornigliano, a district of Genoa (Italy), where a coke oven is located a few hundred metres from the residential area. Methods: The whole of Genoa and one of its 25 districts (Rivarolo) were selected as controls. The trend of risk around the coke oven was evaluated via Stone's method, while the geographic pattern of such risks across the Cornigliano district was evaluated by computing full Bayes estimates of standardised incidence ratio (FBE-SIR). Results: In males, elevated relative risks (RR) were observed for all lymphohaematopoietic cancers (RR 1.7 v Rivarolo and 1.6 v Genoa), for NHL (RR 2.4 v Rivarolo and 1.7 v Genoa), and for leukaemia (RR 2.4 v Rivarolo and 1.9 v Genoa). In females, statistically non-significant RR were observed. In males no excess of risk was found close to the coke oven. In females, a rising risk for NHL was observed approaching the plant, although statistical significance was not reached, while the risk for leukaemia was not evaluable due to the small number of cases. Analysis of the geographic pattern of risk suggested the presence of a cluster of NHL in both sexes in the eastern part of the district, where a foundry had been operational until the early 1980s. A cluster of leukaemia cases was observed in males in a northern part of the area, where no major sources of benzene seemed to be present. Conclusions: The estimated risks seem to be slightly or not at all related to the distance from the coke oven. The statistically significant higher risks observed in males for NHL and leukaemia, and the clusters of leukaemia in males and of NHL in both sexes deserve further investigations in order to trace the exposures associated with such risks. PMID:12598665

  7. Investigations on some aspects of chemical ecology of cogongrass,Imperata cylindrica (L.) Beauv.

    PubMed

    Inderjit; Dakshini, K M

    1991-02-01

    To understand the interference mechanism of the weed, cogongrass,Imperata cylindrica (L.) Beauv., its effect on nutrient availability and mycoflora of its soil rhizosphere as well as nodule characteristics, root length, and root/shoot ratio of Melilotus parviflora Desf. were investigated. Additionally, the effect of the leachates of leaves and root/rhizome of cogongrass on seed germination and seedling characteristics of radish, mustard, fenugreek, and tomato were examined. Furthermore, to assess the qualitative and quantitative differences in phytochemical components, the leachates and the soils from three sampling sites (with cogongrass and 1.5 m and 3 m away from cogongrass) were analyzed with high-performance liquid chromatography (HPLC) on a C18 column. No significant difference in nutrient availability was found, but qualitative and quantitative differences in phenolic fractions were recorded in the three sampling sites. Furthermore, of the 19 fungi recorded in the soils, decreases in the number of colonies (per gram of soil) ofAspergillus fumigatus, A. niger, A. candidus, and an increase of A. flavus was recorded in the soils with cogongrass. The inhibition in nodule number, weight, nitrogen fixation (acetylene reduction activity), root length, and root/shoot ratio of Melilotus parviflora were noted. Percent seed germination, root and shoot length, fresh and dry weight of seedlings of different seeds were affected by the leachates of leaves and root/rhizome. It was found that root/rhizome leachate was more inhibitory than leaf leachate. However, the inhibition was higher in soil+leaves leachate than soil+root/rhizome leachate. HPLC analysis established that four compounds were contributed by the weed to the soil system even though their relative concentration varies in various leachates. It is surmised that these compounds cause allelopathic inhibition of growth characteristics of seeds tested. Significance of the data vis-a-vis the interference potential of

  8. Using Ecological Momentary Assessment to investigate associations between ejaculatory latency and control in partnered and non-partnered sexual activities.

    PubMed

    Jern, Patrick; Gunst, Annika; Sandqvist, Felicia; Sandnabba, N Kenneth; Santtila, Pekka

    2011-07-01

    Ecological Momentary Assessment (EMA) was used to investigate associations between, and variations in, ejaculatory control and ejaculation latency time (ELT) over repeated measurements of sexual activities. Differences between measures recorded in partnered or non-partnered settings were also investigated. The sample consisted of 21 male Finns aged 18 years or above, contributing a total of 158 reports of partnered and non-partnered sexual activities over a six-week period. In the context of non-partnered sexual activities, after controlling for within-subjects dependence, ELTs between events were predictive of one another, but ELT did not predict ejaculatory control when measured simultaneously, nor at subsequent events. Also, ejaculatory control could not predict simultaneously measured ELT or ejaculatory control at subsequent events. During partnered sexual activities, both ejaculatory control and ELT could be accurately predicted by observing ejaculatory control at prior events. In this context, ejaculatory control could also reliably predict simultaneously measured ELT. ELT or ejaculatory control during partnered sexual activity could not be predicted by observing ELT at prior events. Between-event correlations were generally low, indicating considerable variation in ejaculatory functioning over time. EMA is a thrifty assessment method for studying variations in ejaculatory function, and is likely suitable for studying sexual dysfunctions in general.

  9. Experimental and computational investigation of lateral gauge response in polycarbonate

    NASA Astrophysics Data System (ADS)

    Eliot, Jim; Harris, Ernest Joseph; Hazell, Paul; Appleby-Thomas, Gareth James; Winter, Ron; Wood, David Christopher

    2012-03-01

    The shock behaviour of polycarbonate is of interest due to its extensive use in defence applications. Interestingly, embedded lateral manganin stress gauges in polycarbonate have shown gradients behind incident shocks, suggestive of increasing shear strength. However, such gauges are commonly embedded in a central epoxy interlayer. This is an inherently invasive approach. Recently, research has suggested that in such systems interlayer/target impedance may contribute to observed gradients in lateral stress. Here, experimental T-gauge (Vishay Micro-Measurements® type J2M-SS-580SF-025) traces from polycarbonate targets are compared to computational simulations. The effects of gauge environment are investigated by looking at the response of lateral gauges with both standard "glued-joint" and a "dry joint" encapsulation, where no encapsulating medium is employed.

  10. Does physiological response to disease incur cost to reproductive ecology in a sexually dichromatic amphibian species?

    PubMed

    Kindermann, Christina; Narayan, Edward J; Hero, Jean-Marc

    2017-01-01

    It is well known that the disease chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) has contributed to amphibian declines worldwide. The impact of Bd varies, with some species being more susceptible to infection than others. Recent evidence has shown that Bd can have sub-lethal effects, whereby increases in stress hormones have been associated with infection. Could this increased stress response, which is a physiological adaptation that provides an increased resilience against Bd infection, potentially be a trade-off with important life-history traits such as reproduction? We studied this question in adult male frogs of a non-declining species (Litoria wilcoxii). Frogs were sampled for (1) seasonal hormone (testosterone and corticosterone), color and disease profiles, (2) the relationship between disease infection status and hormone levels or dorsal color, (3) subclinical effects of Bd by investigating disease load and hormone level, and (4) reproductive and stress hormone relationships independent of disease. Testosterone levels and color score varied seasonally (throughout the spring/summer months) while corticosterone levels remained stable. Frogs with high Bd prevalence had significantly higher corticosterone levels and lower testosterone levels compared to uninfected frogs, and no differences in color were observed. There was a significant positive correlation between disease load and corticosterone levels, and a significant negative relationship between disease load and testosterone. Our field data provides novel evidence that increased physiological stress response associated with Bd infection in wild frogs, could suppress reproduction by down-regulating gonadal hormones in amphibians, however the impacts on reproductive output is yet to be established.

  11. Somatosensory-evoked blink response: investigation of the physiological mechanisms.

    PubMed

    Miwa, H; Nohara, C; Hotta, M; Shimo, Y; Amemiya, K

    1998-02-01

    The somatosensory-evoked blink response (SBR) is a newly identified blink reflex elicited by electrical stimulation of peripheral nerves. The present study was performed to investigate the physiological mechanism underlying the SBR elicited by median nerve stimulation in normal subjects. The peripheral afferents responsible for the SBR included low-threshold cutaneous fibres. In the SBR-positive subjects, the late (R2) component of the blink reflex elicited by supraorbital nerve stimulation and the SBR facilitated each other when both responses were induced at the same time, but they each caused long-lasting inhibition in the other when one stimulus was given as a conditioning stimulus. The extent of inhibition was correlated with the size of the preceding SBR. In the SBR-negative subjects, simultaneous inhibition of R2 was observed when median nerve stimulation was applied as a conditioning stimulus. Brainstem excitability, as evaluated by blink-reflex recovery studies, did not differ between SBR-positive and SBR-negative subjects. Therefore, based on anatomical and physiological findings, it appears that the reflex pathways of the SBR and R2 converge within the brainstem and compete with each other, presumably by presynaptic inhibition at the premotor level, before entering the common blink-reflex pathway. The influence of median nerve stimulation upon tonic contraction of the orbicularis oculi muscle was studied to detect the latent SBR. There was not only a facilitatory period corresponding to the SBR but also an active inhibitory period (exteroceptive suppression), suggesting that the mechanism generating the SBR is not only influenced by blink-reflex volleys but also by active exteroceptive suppression. Thus, the SBR may appear as a result of integration of facilitatory and inhibitory mechanisms within the brainstem.

  12. An investigation of emotional intelligence measures using item response theory.

    PubMed

    Cho, Seonghee; Drasgow, Fritz; Cao, Mengyang

    2015-12-01

    This study investigated the psychometric properties of 3 frequently administered emotional intelligence (EI) scales (Wong and Law Emotional Intelligence Scale [WLEIS], Schutte Self-Report Emotional Intelligence Test [SEIT], and Trait Emotional Intelligence Questionnaire [TEIQue]), which were developed on the basis of different theoretical frameworks (i.e., ability EI and mixed EI). By conducting item response theory (IRT) analyses, the authors examined the item parameters and compared the fits of 2 response process models (i.e., dominance model and ideal point model) for these scales with data from 355 undergraduate sample recruited from the subject pool. Several important findings were obtained. First, the EI scales seem better able to differentiate individuals at low trait levels than high trait levels. Second, a dominance model showed better model fit to the self-report ability EI scale (WLEIS) and also fit better with most subfactors of the SEIT, except for the mood regulation/optimism factor. Both dominance and ideal point models fit a self-report mixed EI scale (TEIQue). Our findings suggest (a) the EI scales should be revised to include more items at moderate and higher trait levels; and (b) the nature of the EI construct should be considered during the process of scale development.

  13. A stochastic model for ecological systems with strong nonlinear response to environmental drivers: application to two water-borne diseases.

    PubMed

    Codeço, Claudia Torres; Lele, Subhash; Pascual, Mercedes; Bouma, Menno; Ko, Albert I

    2008-02-06

    Ecological systems with threshold behaviour show drastic shifts in population abundance or species diversity in response to small variation in critical parameters. Examples of threshold behaviour arise in resource competition theory, epidemiological theory and environmentally driven population dynamics, to name a few. Although expected from theory, thresholds may be difficult to detect in real datasets due to stochasticity, finite population size and confounding effects that soften the observed shifts and introduce variability in the data. Here, we propose a modelling framework for threshold responses to environmental drivers that allows for a flexible treatment of the transition between regimes, including variation in the sharpness of the transition and the variance of the response. The model assumes two underlying stochastic processes whose mixture determines the system's response. For environmentally driven systems, the mixture is a function of an environmental covariate and the response may exhibit strong nonlinearity. When applied to two datasets for water-borne diseases, the model was able to capture the effect of rainfall on the mean number of cases as well as the variance. A quantitative description of this kind of threshold behaviour is of more general application to predict the response of ecosystems and human health to climate change.

  14. Ecological Changes in Coyotes (Canis latrans) in Response to the Ice Age Megafaunal Extinctions

    PubMed Central

    Meachen, Julie A.; Janowicz, Adrianna C.; Avery, Jori E.; Sadleir, Rudyard W.

    2014-01-01

    Coyotes (Canis latrans) are an important species in human-inhabited areas. They control pests and are the apex predators in many ecosystems. Because of their importance it is imperative to understand how environmental change will affect this species. The end of the Pleistocene Ice Age brought with it many ecological changes for coyotes and here we statistically determine the changes that occurred in coyotes, when these changes occurred, and what the ecological consequences were of these changes. We examined the mandibles of three coyote populations: Pleistocene Rancho La Brean (13–29 Ka), earliest Holocene Rancho La Brean (8–10 Ka), and Recent from North America, using 2D geometric morphometrics to determine the morphological differences among them. Our results show that these three populations were morphologically distinct. The Pleistocene coyotes had an overall robust mandible with an increased shearing arcade and a decreased grinding arcade, adapted for carnivory and killing larger prey; whereas the modern populations show a gracile morphology with a tendency toward omnivory or grinding. The earliest Holocene populations are intermediate in morphology and smallest in size. These findings indicate that a niche shift occurred in coyotes at the Pleistocene/Holocene boundary – from a hunter of large prey to a small prey/more omnivorous animal. Species interactions between Canis were the most likely cause of this transition. This study shows that the Pleistocene extinction event affected species that did not go extinct as well as those that did. PMID:25551387

  15. No Boundaries: Genomes, Organisms, and Ecological Interactions Responsible for Divergence and Reproductive Isolation

    PubMed Central

    2014-01-01

    Revealing the genetic basis of traits that cause reproductive isolation, particularly premating or sexual isolation, usually involves the same challenges as most attempts at genotype–phenotype mapping and so requires knowledge of how these traits are expressed in different individuals, populations, and environments, particularly under natural conditions. Genetic dissection of speciation phenotypes thus requires understanding of the internal and external contexts in which underlying genetic elements are expressed. Gene expression is a product of complex interacting factors internal and external to the organism including developmental programs, the genetic background including nuclear–cytotype interactions, epistatic relationships, interactions among individuals or social effects, stochasticity, and prevailing variation in ecological conditions. Understanding of genomic divergence associated with reproductive isolation will be facilitated by functional expression analysis of annotated genomes in organisms with well-studied evolutionary histories, phylogenetic affinities, and known patterns of ecological variation throughout their life cycles. I review progress and prospects for understanding the pervasive role of host plant use on genetic and phenotypic expression of reproductive isolating mechanisms in cactophilic Drosophila mojavensis and suggest how this system can be used as a model for revealing the genetic basis for species formation in organisms where speciation phenotypes are under the joint influences of genetic and environmental factors. PMID:25149252

  16. Ecological changes in Coyotes (Canis latrans) in response to the ice age megafaunal extinctions.

    PubMed

    Meachen, Julie A; Janowicz, Adrianna C; Avery, Jori E; Sadleir, Rudyard W

    2014-01-01

    Coyotes (Canis latrans) are an important species in human-inhabited areas. They control pests and are the apex predators in many ecosystems. Because of their importance it is imperative to understand how environmental change will affect this species. The end of the Pleistocene Ice Age brought with it many ecological changes for coyotes and here we statistically determine the changes that occurred in coyotes, when these changes occurred, and what the ecological consequences were of these changes. We examined the mandibles of three coyote populations: Pleistocene Rancho La Brean (13-29 Ka), earliest Holocene Rancho La Brean (8-10 Ka), and Recent from North America, using 2D geometric morphometrics to determine the morphological differences among them. Our results show that these three populations were morphologically distinct. The Pleistocene coyotes had an overall robust mandible with an increased shearing arcade and a decreased grinding arcade, adapted for carnivory and killing larger prey; whereas the modern populations show a gracile morphology with a tendency toward omnivory or grinding. The earliest Holocene populations are intermediate in morphology and smallest in size. These findings indicate that a niche shift occurred in coyotes at the Pleistocene/Holocene boundary - from a hunter of large prey to a small prey/more omnivorous animal. Species interactions between Canis were the most likely cause of this transition. This study shows that the Pleistocene extinction event affected species that did not go extinct as well as those that did.

  17. Modeling post-fledging survival of lark buntings in response to ecological and biological factors

    USGS Publications Warehouse

    Yackel Adams, A.A.; Skagen, S.K.; Savidge, J.A.

    2006-01-01

    We evaluated the influences of several ecological, biological, and methodological factors on post-fledging survival of a shortgrass prairie bird, the Lark Bunting (Calamospiza melanocorys). We estimated daily post-fledging survival (n = 206, 82 broods) using radiotelemetry and color bands to track fledglings. Daily survival probabilities were best explained by drought intensity, time in season (quadratic trend), ages a??3 d post-fledging, and rank given drought intensity. Drought intensity had a strong negative effect on survival. Rank was an important predictor of fledgling survival only during the severe drought of 2002 when the smallest fledglings had lower survival. Recently fledged young (ages a??3 d post-fledging) undergoing the transition from nest to surrounding habitat experienced markedly lower survival, demonstrating the vulnerable nature of this time period. Survival was greater in mid and late season than early season, corresponding to our assumptions of food availability. Neither mark type nor sex of attending parent influenced survival. The model-averaged product of the 22-d survival calculated using mean rank and median value of time in season was 0.360 A? 0.08 in 2001 and 0.276 A? 0.08 in 2002. Survival estimates that account for age, condition of young, ecological conditions, and other factors are important for parameterization of realistic population models. Biologists using population growth models to elucidate mechanisms of population declines should attempt to estimate species-specific of post-fledging survival rather than use generalized estimates.

  18. Using Ecological Momentary Assessment to Investigate Short-Term Variations in Sexual Functioning in a Sample of Peri-Menopausal Women from Iran

    PubMed Central

    Pakpour, Amir H.; Yekaninejad, Mir Saeed; Pallich, Gianandrea; Burri, Andrea

    2015-01-01

    The investigation of short-term changes in female sexual functioning has received little attention so far. The aims of the study were to gain empirical knowledge on within-subject and within- and across-variable fluctuations in women’s sexual functioning over time. More specifically, to investigate the stability of women´s self-reported sexual functioning and the moderating effects of contextual and interpersonal factors. A convenience sample of 206 women, recruited across eight Health care Clinics in Rasht, Iran. Ecological momentary assessment was used to examine fluctuations of sexual functioning over a six week period. A shortened version of the Female Sexual Function Index (FSFI) was applied to assess sexual functioning. Self-constructed questions were included to assess relationship satisfaction, partner’s sexual performance and stress levels. Mixed linear two-level model analyses revealed a link between orgasm and relationship satisfaction (Beta = 0.125, P = 0.074) with this link varying significantly between women. Analyses further revealed a significant negative association between stress and all six domains of women’s sexual functioning. Women not only reported differing levels of stress over the course of the assessment period, but further differed from each other in how much stress they experienced and how much this influenced their sexual response. Orgasm and sexual satisfaction were both significantly associated with all other domains of sexual function (P<0.001). And finally, a link between partner performance and all domains of women`s sexual functioning (P<0.001) could be detected. Except for lubrication (P = 0.717), relationship satisfaction had a significant effect on all domains of the sexual response (P<0.001). Overall, our findings support the new group of criteria introduced in the DSM-5, called “associated features” such as partner factors and relationship factors. Consideration of these criteria is important and necessary for

  19. Using ecological momentary assessment to investigate short-term variations in sexual functioning in a sample of peri-menopausal women from Iran.

    PubMed

    Pakpour, Amir H; Yekaninejad, Mir Saeed; Pallich, Gianandrea; Burri, Andrea

    2015-01-01

    The investigation of short-term changes in female sexual functioning has received little attention so far. The aims of the study were to gain empirical knowledge on within-subject and within- and across-variable fluctuations in women's sexual functioning over time. More specifically, to investigate the stability of women´s self-reported sexual functioning and the moderating effects of contextual and interpersonal factors. A convenience sample of 206 women, recruited across eight Health care Clinics in Rasht, Iran. Ecological momentary assessment was used to examine fluctuations of sexual functioning over a six week period. A shortened version of the Female Sexual Function Index (FSFI) was applied to assess sexual functioning. Self-constructed questions were included to assess relationship satisfaction, partner's sexual performance and stress levels. Mixed linear two-level model analyses revealed a link between orgasm and relationship satisfaction (Beta = 0.125, P = 0.074) with this link varying significantly between women. Analyses further revealed a significant negative association between stress and all six domains of women's sexual functioning. Women not only reported differing levels of stress over the course of the assessment period, but further differed from each other in how much stress they experienced and how much this influenced their sexual response. Orgasm and sexual satisfaction were both significantly associated with all other domains of sexual function (P<0.001). And finally, a link between partner performance and all domains of women`s sexual functioning (P<0.001) could be detected. Except for lubrication (P = 0.717), relationship satisfaction had a significant effect on all domains of the sexual response (P<0.001). Overall, our findings support the new group of criteria introduced in the DSM-5, called "associated features" such as partner factors and relationship factors. Consideration of these criteria is important and necessary for clinicians

  20. Biochemical ecology of the forest tent caterpillar: responses to dietary protein and phenolic glycosides.

    PubMed

    Lindroth, Richard L; Bloomer, Mark S

    1991-05-01

    Interactions between quaking aspen (Populus tremuloides) and the forest tent caterpillar (Malacosoma disstria) are likely to be influenced by leaf protein and phenolic glycoside levels, and insect detoxication activity. We investigated the direct and interactive effects of dietary protein and phenolic glycosides on larval performance and midgut enzyme activity of forest tent caterpillars. We conducted bioassays with six artificial diets, using both first and fourth stadium larvae. Four of the diets comprised a 2×2 factorial design-two levels of protein, each with and without phenolic glycosides. Additionally, we assayed high protein diets containing S,S,S-tributylphosphorotrithioate (DEF, an esterase inhibitor) and DEF plus phenolic glycosides. Enzyme solutions were prepared from midguts of sixth instars and assayed for β-glucosidase, esterase and glutathione transferase activities. First instar mortality and development times were higher for larvae on diets low in protein or containing phenolic glycosides. Effects of phenolic glycosides were especially pronounced at low protein levels and when administered with DEF. Fourth instar development times were prolonged, and growth rates reduced, in response to consumption of low protein diets. Effects of phenolic glycosides on growth were less pronounced, although the effect for larvae on the low protein diet was nearly significant. Activity of each of the enzyme systems was reduced in larvae reared on low protein diets, and esterase activity was induced in larvae fed phenolic glycosides. Our results suggest that larval performance may be strongly affected by levels of protein and phenolic glycosides commonly occurring in aspen foliage, and that these factors may play a role in differential defoliation of aspen by forest tent caterpillars.

  1. Seeing the Wood for the Trees: Applying the Dual-Memory System Model to Investigate Expert Teachers' Observational Skills in Natural Ecological Learning Environments

    ERIC Educational Resources Information Center

    Stolpe, Karin; Bjorklund, Lars

    2012-01-01

    This study aims to investigate two expert ecology teachers' ability to attend to essential details in a complex environment during a field excursion, as well as how they teach this ability to their students. In applying a cognitive dual-memory system model for learning, we also suggest a rationale for their behaviour. The model implies two…

  2. Biotic response to late Quaternary rapid climate switches in Santa Barbara Basin: Ecological and evolutionary implications

    SciTech Connect

    Cannariato, K.G.; Kennett, J.P.; Behl, R.J.

    1999-01-01

    Benthic foraminiferal assemblages from Santa Barbara Basin exhibit major faunal and ecological switches associated with late Quaternary millennial- to decadal-scale global climate oscillations. Repeated turnovers of entire faunas occurred rapidly (<40--400 yr) without extinction or speciation in conjunction with Dansgaard-Oeschger shifts in thermohaline circulation, ventilation, and climate, confirming evolutionary model predictions of Roy et al. Consistent faunal successions of dysoxic taxa during successive interstadials reflect the extreme sensitivity and adaptation of the benthic ecosystem to the rapid environmental changes that marked the late Quaternary and possibly other transitional intervals in the history of the Earth`s ocean-atmosphere-cryosphere system. These data support the hypothesis that broad segments of the biosphere are well adapted to rapid climate change.

  3. Ecological scale of bird community response to piñon-juniper removal

    USGS Publications Warehouse

    Knick, Steven T.; Hanser, Steven E.; Leu, Matthias

    2014-01-01

    Piñon (Pinus spp.) and juniper (Juniperus spp.) removal is a common management approach to restore sagebrush (Artemisia spp.) vegetation in areas experiencing woodland expansion. Because many management treatments are conducted to benefit sagebrush-obligate birds, we surveyed bird communities to assess treatment effectiveness in establishing sagebrush bird communities at study sites in Utah, Nevada, Idaho, and Oregon. Our analyses included data from 1 or 2 yr prior to prescribed fire or mechanical treatment and 3 to 5 yr posttreatment. We used detrended correspondence analysis to 1) identify primary patterns of bird communities surveyed from 2006 to 2011 at point transects, 2) estimate ecological scale of change needed to achieve treatment objectives from the relative dissimilarity of survey points to the ordination region delineating sagebrush bird communities, and 3) measure changes in pre- and posttreatment bird communities. Birds associated with sagebrush, woodlands, and ecotones were detected on our surveys; increased dissimilarity of survey points to the sagebrush bird community was characterized by a gradient of increased juniper and decreased sagebrush cover. Prescribed fires burned between 30% and 97% of our bird survey points. However, from 6% to 24% cover of piñon-juniper still remained posttreatment on the four treatment plots. We measured only slight changes in bird communities, which responded primarily to current vegetation rather than relative amount of change from pretreatment vegetation structure. Bird communities at survey points located at greater ecological scales from the sagebrush bird community changed least and will require more significant impact to achieve changes. Sagebrush bird communities were established at only two survey points, which were adjacent to a larger sagebrush landscape and following almost complete juniper removal by mechanical treatment. Our results indicate that management treatments that leave residual woodland cover

  4. Investigation of growth responses in saprophytic fungi to charred biomass.

    PubMed

    Ascough, Philippa L; Sturrock, Craig J; Bird, Michael I

    2010-03-01

    We present the results of a study testing the response of two saprophytic white-rot fungi species, Pleurotus pulmonarius and Coriolus versicolor, to charred biomass (charcoal) as a growth substrate. We used a combination of optical microscopy, scanning electron microscopy, elemental abundance measurements, and isotope ratio mass spectrometry ((13)C and (15)N) to investigate fungal colonisation of control and incubated samples of Scots Pine (Pinus sylvestris) wood, and charcoal from the same species produced at 300 degrees C and 400 degrees C. Both species of fungi colonise the surface and interior of wood and charcoals over time periods of less than 70 days; however, distinctly different growth forms are evident between the exterior and interior of the charcoal substrate, with hyphal penetration concentrated along lines of structural weakness. Although the fungi were able to degrade and metabolise the pine wood, charcoal does not form a readily available source of fungal nutrients at least for these species under the conditions used in this study.

  5. Investigation of cellular responses upon interaction with silver nanoparticles

    PubMed Central

    Subbiah, Ramesh; Jeon, Seong Beom; Park, Kwideok; Ahn, Sang Jung; Yun, Kyusik

    2015-01-01

    In order for nanoparticles (NPs) to be applied in the biomedical field, a thorough investigation of their interactions with biological systems is required. Although this is a growing area of research, there is a paucity of comprehensive data in cell-based studies. To address this, we analyzed the physicomechanical responses of human alveolar epithelial cells (A549), mouse fibroblasts (NIH3T3), and human bone marrow stromal cells (HS-5), following their interaction with silver nanoparticles (AgNPs). When compared with kanamycin, AgNPs exhibited moderate antibacterial activity. Cell viability ranged from ≤80% at a high AgNPs dose (40 µg/mL) to >95% at a low dose (10 µg/mL). We also used atomic force microscopy-coupled force spectroscopy to evaluate the biophysical and biomechanical properties of cells. This revealed that AgNPs treatment increased the surface roughness (P<0.001) and stiffness (P<0.001) of cells. Certain cellular changes are likely due to interaction of the AgNPs with the cell surface. The degree to which cellular morphology was altered directly proportional to the level of AgNP-induced cytotoxicity. Together, these data suggest that atomic force microscopy can be used as a potential tool to develop a biomechanics-based biomarker for the evaluation of NP-dependent cytotoxicity and cytopathology. PMID:26346562

  6. Hypoosmotic stress in the mussel Perna perna (Linnaeus, 1758): Is ecological history a determinant for organismal responses?

    NASA Astrophysics Data System (ADS)

    Rola, Regina Coimbra; Souza, Marta Marques; Sandrini, Juliana Zomer

    2017-04-01

    Ecological history of organisms may be related to different responses and adaptations to stressors. This study aims to evaluate whether marine brown mussels (Perna perna Linnaeus, 1758) collected from sites with distinct histories of fluctuations in abiotic parameters, including salinity, respond differently to hypoosmotic stress. Mussels were collected at different sites (a marine site, with no history of salinity variation, and an estuarine site, with usual salinity variations) and exposed in laboratory for 14 days to hypoosmotic stress (salinities 25 and 20). It was observed that mussels collected at the marine site showed increased oxygen consumption (VO2), reduced haemolymph osmolality and concentrations of Na+, Cl-, and K+; increased levels of ninhydrin-positive substances in the haemolymph, and no changes in gill Na+/K+-ATPase activity, as expected for osmoconforming organisms. For animals collected at the estuarine site, except for VO2, this same pattern was only observed on day 1 of hypoosmotic stress. Unexpectedly, on days 4 and 14, VO2 decreased, the osmolality and ionic concentration returned to near baseline values, and mussels gill Na+/K+-ATPase activity increased at day 4. This long-term response detected for estuarine mussels is similar to that observed for osmoregulating organisms, which is very unexpected for marine bivalves. Despite being novel in the relevant literature, these results suggest that in some situations mussels could adopt osmoregulating behavior, such as increasing Na+/K+-ATPase activity and thereby probably reducing water circulating inside valves. In conclusion, these results indicate that ecological history, shown here by differences in organismal origin, influence physiological parameters of mussels in response to a stressful situation.

  7. Investigating the Response of Microbial Communities to Cyclodextrin

    NASA Astrophysics Data System (ADS)

    Szponar, N.; Slater, G.; Smith, J.

    2009-05-01

    Recent studies have found applications of hydroxypropyl-β-cyclodextrin (HPβCD) to be highly effective in removing DDT from soils in situ. However, the persistence of HPβCD within the soil and its impact on soil microbial communities is still unclear. It has been suggested that cyclodextrin might provide a substrate for microbial communities resulting in changes in the ongoing effectiveness of remediation and/or soil hydraulic properties. The potential exists that stimulation of the soil microbial community may contribute to removal of DDT, along with the solubilization effects normally associated with cyclodextrin treatment. This study investigated the response of soil microbial communities from a site undergoing remediation of DDT with HPβCD through microcosm and bench scale column studies. Phospholipid fatty acid (PLFA) analysis and their natural abundance 13C signatures can be used to identify in situ microbial metabolism of HPβCD. Heterotrophic organisms have PLFA with 13C signatures 3 to 6‰ depleted from their carbon source. Cyclodextrin was found to have a δ13C of -16‰ resulting from its formation via enzymatic degradation of cornstarch. In contrast, soil organic matter, had a predominantly C3 plant derived signature and a δ13C of -25‰. Incorporation of HPβCD by soil microbial communities would therefore cause a shift to a more enriched isotopic value. While microcosm studies demonstrated no noticeable change in biomass and few changes in PLFA distribution, column studies treated with a 10% solution of HPβCD demonstrated an approximate doubling of microbial biomass after 6 weeks of application based on PLFA concentrations. Concurrent changes in PLFA distribution further indicated a response to cyclodextrin. Changes in PLFA concentration and distribution were concurrent with isotopic enrichment of PLFA in treated columns. This isotopic enrichment provided direct evidence for microbial consumption of cyclodextrin. Incorporation of 13C enriched

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

    USGS Publications Warehouse

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

    2012-01-01

    size of saltglands when demands are low suggests that any time costs of adjustment are lower than the costs of maintaining a larger size in this small but essential piece of metabolic machinery. ?? 2011 The Authors. Functional Ecology ?? 2011 British Ecological Society.

  9. [Ecology and ecologies].

    PubMed

    Valera, Luca

    2011-01-01

    Ecology (from the Greek words οιχοσ, "house" and λογια "study of") is the science of the "house", since it studies the environments where we live. There are three main ways of thinking about Ecology: Ecology as the study of interactions (between humans and the environment, between humans and living beings, between all living beings, etc.), Ecology as the statistical study of interactions, Ecology as a faith, or rather as a science that requires a metaphysical view. The history of Ecology shows us how this view was released by the label of "folk sense" to gain the epistemological status of science, a science that strives to be interdisciplinary. So, the aim of Ecology is to study, through a scientific methodology, the whole natural world, answering to very different questions, that arise from several fields (Economics, Biology, Sociology, Philosophy, etc.). The plurality of issues that Ecology has to face led, during the Twentieth-century, to branch off in several different "ecologies". As a result, each one of these new approaches chose as its own field a more limited and specific portion of reality.

  10. 21 CFR 812.110 - Specific responsibilities of investigators.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... investigation in accordance with the signed agreement with the sponsor, the investigational plan, this part and... determine whether potential subjects would be interested in participating in an investigation, but shall not... investigation and for 1 year following completion of the study. (e) Disposing of device. Upon completion...

  11. FACTORS AFFECTING SENSITIVITY OF CHEMICAL AND ECOLOGICAL RESPONSES OF MARINE EMBAYMEMTS TO NITROGEN LOADING

    EPA Science Inventory

    This paper summarizes an ongoing examination of the primary factors that affect sensitivity of marine embayment responses to nitrogen loading. Included is a discussion of two methods for using these factors: classification of embayments into discrete sensitivity classes and norma...

  12. Experimental investigation of the electrocaloric response in ferroelectric materials

    NASA Astrophysics Data System (ADS)

    Es'kov, A. V.; Belyavskii, P. Yu.; Anokhin, A. S.; Pakhomov, O. V.; Semenov, A. A.; Myl'nikov, I. L.; Nikitin, A. A.; Bui, M. T.; Cherkasskii, M. A.; Plotnikov, V. V.

    2016-07-01

    We have analyzed the electrocaloric response in ferroelectric materials in nonequilibrium thermal conditions. The temperature dependences of the electrocaloric response during polarization and depolarization of ferroelectric samples based on solid solutions of barium-strontium titanate and lead magnoniobate-titanate are considered. The difference in the electrocaloric responses for polarization and depolarization, which can be as large as 5 mK, has been demonstrated experimentally.

  13. Response to environmental flows in the Lower Tarim River, Xinjiang, China: an ecological interpretation of water-table dynamics.

    PubMed

    Hou, P; Beeton, R J S; Carter, R W; Dong, X G; Li, X

    2007-06-01

    Increased water-dependent development and utilization have led to significant environmental and hydrological degradation of the Tarim River in western China and its dependent ecosystems. Between the 1950s and 1970s, 350 km of the lower reaches were drained and between 1960 and 1980 the water-table fell from between -2 and -3 m to between -8 and -10 m. Subsequently, riparian ecosystems were seriously degraded. In 2000, the Chinese government launched a program to restore the lower reaches of the river. Four environmental flows of 1034 x 10(6) m(3) were released from 2000 to 2002. This paper interprets and discusses the ecological significance of changes following the releases and identifies the relationship between water-table dynamics and vegetation responses. Short-term objectives for river restoration are proposed with possible monitoring parameters suggested.

  14. The Ecosystem Concept and Linking Models of Physical-Chemical Processes to Ecological Responses: Introduction and Annotated Bibliography

    DTIC Science & Technology

    2007-07-01

    Schneider, D. C. 1994. Quantitative ecology. Spatial and temporal scaling. Academic Press. Shugart, H. H. 1990. Ecological models and the ecotone . In: The...ecology and management of aquatic-terrestrial ecotones . Man and the biosphere series, Vol. 4. ed. R. J. Naiman and H. Decamps, 23-36. Paris, France

  15. Investigation of Response Changes in the GRE Revised General Test

    ERIC Educational Resources Information Center

    Liu, Ou Lydia; Bridgeman, Brent; Gu, Lixiong; Xu, Jun; Kong, Nan

    2015-01-01

    Research on examinees' response changes on multiple-choice tests over the past 80 years has yielded some consistent findings, including that most examinees make score gains by changing answers. This study expands the research on response changes by focusing on a high-stakes admissions test--the Verbal Reasoning and Quantitative Reasoning measures…

  16. Identity Status and Empathic Response Patterns: A Multidimensional Investigation.

    ERIC Educational Resources Information Center

    Erlanger, David M.

    1998-01-01

    The multidimensional empathic response patterns of late adolescent undergraduate students (N=153) was examined according to their identity status. Subjects completed self-report measures of empathic response style and identity development. Findings for empathic concern, cognitive empathy, and empathic distress are related to identity status…

  17. Reinforcement Sensitivity and Responsiveness to Performance Feedback: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Lovett, Benjamin J.; Eckert, Tanya L.

    2009-01-01

    Variability in responsiveness to academic interventions is a common phenomenon in school psychology practice, but the variables associated with this responsiveness are not well understood. Reinforcement sensitivity, a generalized tendency to learn quickly in reward contingency situations, is one variable for increased understanding. In the present…

  18. An Investigation of Response Bias in the Chapman Scales.

    ERIC Educational Resources Information Center

    Peltier, B. David; Walsh, James A.

    1990-01-01

    The major response sets that can adversely affect the validity and usefulness of trait scales are briefly described. Using data from 228 college students, representative response set measures were then used to assess the degree to which scores on 4 of the Chapman Scales are determined by content-irrelevant factors. (TJH)

  19. A system for identifying and investigating unexpected response to treatment.

    PubMed

    Ozery-Flato, Michal; Ein-Dor, Liat; Neuvirth, Hani; Parush, Naama; Kohn, Martin S; Hu, Jianying; Aharonov, Ranit

    2015-01-01

    The availability of electronic health records creates fertile ground for developing computational models for various medical conditions. Using machine learning, we can detect patients with unexpected responses to treatment and provide statistical testing and visualization tools to help further analysis. The new system was developed to help researchers uncover new features associated with reduced response to treatment, and to aid physicians in identifying patients that are not responding to treatment as expected and hence deserve more attention. The solution computes a statistical score for the deviation of a given patient's response from responses observed individuals with similar characteristics and medication regimens. Statistical tests are then applied to identify clinical features that correlate with cohorts of patients showing deviant responses. The results provide comprehensive visualizations, both at the cohort and the individual patient levels. We demonstrate the utility of this system in a population of diabetic patients.

  20. Theoretical investigation of the oceanic inverted barometer response

    NASA Technical Reports Server (NTRS)

    Dickman, S. R.

    1988-01-01

    Dynamic tidal theory is generalized in order to predict the oceanic response to atmospheric pressure variations. The oceans are found to exhibit distinct dynamic behavior when forced at periods less than one week; depending on the harmonic type of forcing, the amplitude of the response can differ by about 20 percent or more from the static response. Even at roughly two months the traditional 'inverted barometer' may not be sufficiently accurate for applications in which detection of long-term sea level trends or vertical crustal motion is the goal. For forcing at periods of order one year the oceanic response differs by at most a few percent from the static (not the inverted barometer) response; thus calculations of meteorological excitation of the annual and Chandler wobbles can employ the static approximation without reservation.

  1. Ecology of SO2 resistance : IV. Predicting metabolic responses of fumigated shrubs and trees.

    PubMed

    Winner, W E; Koch, G W; Mooney, H A

    1982-01-01

    10 broadleafed trees and shrubs native to the mediterranean climactic zone in California were surveyed for their photosynthetic and stomatal responses to SO2. These species ranged from drought deciduous to evergreen and had diverse responses to SO2. These results suggest an approach for predicting SO2 resistances of plants.We found that conductance values of plants in SO2-free air can be used to estimate the quantity of SO2 which plants absorb. These estimates are based on conductance values for plants in non-limiting environmental conditions. SO2 absorption quantities are then used to predict relative photosynthesis following the fumigation. Thus, relative photosynthesis of plants following fumigation can be predicted on the basis of conductance in SO2-free air. This approach to predicting SO2 resistances of plants includes analysis of their stomatal responses to fumigation, their characteristics of SO2 adsorption and absorption, and their change in photosynthesis resulting from SO2 stress.

  2. Streamflow Responses and Ecological Implications of Climate Change in New York City Water Supply Watershed

    NASA Astrophysics Data System (ADS)

    Pradhanang, S. M.; Mukundan, R.; Schneiderman, E.; Zion, M. S.; Swamy, A.; Pierson, D. C.; Frei, A.; Easton, Z. M.; Fuka, D. R.; Steenhuis, T. S.

    2011-12-01

    The impact of climate change in the North East United States is already observed in the form of shorter winter, higher annual average temperature, and more frequent extreme heat and precipitation events. These changes could have profound effects on the New York City (NYC) Water Supply and ecological integrity of the watersheds; and the implications of such changes are not well understood. The objective of this study is to examine how future changes in precipitation and air temperature may translate into changes in streamflow in the NYC Water Supply watershed using the Soil and Water Assessment Tool-Water Balance (SWAT-WB). A comparative analysis between simulated streamflow for baseline period (1964-2008) and future scenarios (2081-2100) was carried out for streamflow indicators that are important for understanding how river flow dynamics will impact the water supply, aquatic health, and physical structures in the stream corridor. We analyze the impacts of changes in the magnitude, timing, duration, frequency, and rate of hydrologic events using the Indicators of Hydrologic Alteration (IHA) tool. Our results indicate that warming during the winter and the early spring diminishes snowpack and influence timing of snowmelt. The winter and spring streamflow are projected to increase but summer will be drier in future. Decreased flow during April and summer months will influence timing of fish spawning and their habitats. Low flows, hydrograph pulses, rise and fall rates are expected to increase due to climate change, potentially creating unfavorable conditions for native species and aquatic invertebrates inhabiting along river's edge, and affecting stream bank stability and physical structures.

  3. Salinity and Temperature Effects on Physiological Responses of Vibrio fischeri from Diverse Ecological Niches

    PubMed Central

    Soto, W.; Gutierrez, J.; Remmenga, M. D.; Nishiguchi, M. K.

    2009-01-01

    Vibrio fischeri is a bioluminescent bacterial symbiont of sepiolid squids (Cephalopoda: Sepiolidae) and monocentrid fishes (Actinopterygii: Monocentridae). V. fischeri exhibit competitive dominance within the allopatrically distributed squid genus Euprymna, which have led to the evolution of V. fischeri host specialists. In contrast, the host genus Sepiola contains sympatric species that is thought to have given rise to V. fischeri that have evolved as host generalists. Given that these ecological lifestyles may have a direct effect upon the growth spectrum and survival limits in contrasting environments, optimal growth ranges were obtained for numerous V. fischeri isolates from both free-living and host environments. Upper and lower limits of growth were observed in sodium chloride concentrations ranging from 0.0% to 9.0%. Sepiola symbiotic isolates possessed the least variation in growth throughout the entire salinity gradient, whereas isolates from Euprymna were the least uniform at <2.0% NaCl. V. fischeri fish symbionts (CG101 and MJ101) and all free-living strains were the most dissimilar at >5.0% NaCl. Growth kinetics of symbiotic V. fischeri strains were also measured under a range of salinity and temperature combinations. Symbiotic V. fischeri ES114 and ET101 exhibited a synergistic effect for salinity and temperature, where significant differences in growth rates due to salinity existed only at low temperatures. Thus, abiotic factors such as temperature and salinity have differential effects between free-living and symbiotic strains of V. fischeri, which may alter colonization efficiency prior to infection. PMID:18587609

  4. Placing prairie pothole wetlands along spatial and temporal continua to improve integration of wetland function in ecological investigations

    USGS Publications Warehouse

    Euliss, Ned H.; Mushet, David M.; Newton, Wesley E.; Otto, Clint R.V.; Nelson, Richard D.; LaBaugh, James W.; Scherff, Eric J.; Rosenberry, Donald O.

    2014-01-01

    We evaluated the efficacy of using chemical characteristics to rank wetland relation to surface and groundwater along a hydrologic continuum ranging from groundwater recharge to groundwater discharge. We used 27 years (1974–2002) of water chemistry data from 15 prairie pothole wetlands and known hydrologic connections of these wetlands to groundwater to evaluate spatial and temporal patterns in chemical characteristics that correspond to the unique ecosystem functions each wetland performed. Due to the mineral content and the low permeability rate of glacial till and soils, salinity of wetland waters increased along a continuum of wetland relation to groundwater recharge, flow-through or discharge. Mean inter-annual specific conductance (a proxy for salinity) increased along this continuum from wetlands that recharge groundwater being fresh to wetlands that receive groundwater discharge being the most saline, and wetlands that both recharge and discharge to groundwater (i.e., groundwater flow-through wetlands) being of intermediate salinity. The primary axis from a principal component analysis revealed that specific conductance (and major ions affecting conductance) explained 71% of the variation in wetland chemistry over the 27 years of this investigation. We found that long-term averages from this axis were useful to identify a wetland’s long-term relation to surface and groundwater. Yearly or seasonal measurements of specific conductance can be less definitive because of highly dynamic inter- and intra-annual climate cycles that affect water volumes and the interaction of groundwater and geologic materials, and thereby influence the chemical composition of wetland waters. The influence of wetland relation to surface and groundwater on water chemistry has application in many scientific disciplines and is especially needed to improve ecological understanding in wetland investigations. We suggest ways that monitoring in situ wetland conditions could be linked

  5. The experimental investigation of bounce characteristics of ACV responsive skirt

    NASA Astrophysics Data System (ADS)

    Zhou, W. L.; Ma, T.

    This paper presents some experimental results on the bounce characteristics of the bag-finger responsive skirt and on skirt frequency response under cushion pressure excitation obtained in a large-scale box facility. The influence of some parameters on the amplitude and frequency of the skirt bounce motion and the amplitude of the cushion pressure oscillation were explored, and the corresponding bounce boundary curves are given. Some interesting nonlinear phenomena related to the skirt instability in the time domain response are presented. The mechanism for skirt bounce and the important parameters affecting skirt dynamic stability are examined, and some means for eliminating skirt bounce are introduced.

  6. Space-time integration to assess ecological response to river restoration efforts

    NASA Astrophysics Data System (ADS)

    Power, M. E.; Wilcock, P.; Dietrich, W. E.; Palen, W.; Bode, C.

    2005-12-01

    To detect impacts of restoration measures on populations or ecosystem processes in rivers and watersheds, we must 1) relate local changes in state across the watershed to trajectories over time at downstream receiving points; and 2) distinguish responses to restoration measures from background fluctuations. Both tasks are challenging because of the extreme spatial heterogeneity and complex dynamics of watersheds and watershed processes over potentially relevant scales that range from seconds to centuries and mm2 to 1000's of km2. Despite these challenging realities, environmental scientists and managers are asked to assess the status and responses of riverine ecosystems following restoration efforts with modest, or no support for watershed-scale monitoring. Here we discuss selected research results that document temporal and spatial scales of responses to structural changes in channels by processes that underpin food webs that deliver ecosystem goods or services to society. The trajectories of some types of responses (e.g. uptake and detoxification or outgassing of pollutants) may be detectable over relatively short time scales (months or years); but others (population trajectories of resident salmonids) may require decades of monitoring before the magnitude and direction of effects are clear. We also discuss how new remote and in situ sensing technologies, and ongoing combinations of low and high tech approaches, could support the expanded monitoring programs that will be essential for realistic evaluations of the long-term efficacy of river restoration measures.

  7. Ecological traits affect the response of tropical forest bird species to land-use intensity.

    PubMed

    Newbold, Tim; Scharlemann, Jörn P W; Butchart, Stuart H M; Sekercioğlu, Cağan H; Alkemade, Rob; Booth, Hollie; Purves, Drew W

    2013-01-07

    Land-use change is one of the main drivers of current and likely future biodiversity loss. Therefore, understanding how species are affected by it is crucial to guide conservation decisions. Species respond differently to land-use change, possibly related to their traits. Using pan-tropical data on bird occurrence and abundance across a human land-use intensity gradient, we tested the effects of seven traits on observed responses. A likelihood-based approach allowed us to quantify uncertainty in modelled responses, essential for applying the model to project future change. Compared with undisturbed habitats, the average probability of occurrence of bird species was 7.8 per cent and 31.4 per cent lower, and abundance declined by 3.7 per cent and 19.2 per cent in habitats with low and high human land-use intensity, respectively. Five of the seven traits tested affected the observed responses significantly: long-lived, large, non-migratory, primarily frugivorous or insectivorous forest specialists were both less likely to occur and less abundant in more intensively used habitats than short-lived, small, migratory, non-frugivorous/insectivorous habitat generalists. The finding that species responses to land use depend on their traits is important for understanding ecosystem functioning, because species' traits determine their contribution to ecosystem processes. Furthermore, the loss of species with particular traits might have implications for the delivery of ecosystem services.

  8. EUTROPHICATION OF COASTAL WATER BODIES: RELATIONSHIPS BETWEEN NUTRIENT LOADINGS AND ECOLOGICAL RESPONSE

    EPA Science Inventory

    This newly initiated research is intended to provide environmental managers with an empirical method to develop regional nutrient input limits for East Coast estuaries and other coastal water bodies. Our goal is to create an improved model of nutrient load-response relationships....

  9. EUTROPHICATION OF COASTAL WATER BODIES: RELATIONSHIPS BETWEEN NUTRIENT LOADING AND ECOLOGICAL RESPONSE

    EPA Science Inventory

    This newly initiated research will provide environmental managers with an empirical method to develop regional nutrient input limits for East Coast estuaries/coastal water bodies. The goal will be to reduce the current uncertainty associated with nutrient load-response relationsh...

  10. Ecology, Microbial

    SciTech Connect

    Konopka, Allan

    2009-03-19

    Microbial ecology is a relatively young discipline within the field of microbiology. Its modern history spans just the past 60 years, and the field is defined by its emphasis on understanding the interactions of microbes with their environment, rather than their behavior under artificial laboratory conditions. Because microbes are ubiquitous, microbial ecologists study a broad diversity of habitats that range from aquatic to terrestrial to plant- or animal-associated. This has made it a challenge to identify unifying principles within the field. One approach is to recognize that although the activity of microbes in nature have effects at the macroscale, they interact with their physical, chemical and biological milieu at a scale of micrometers. At this scale, several different microbial ecosystems can be defined, based upon association with particles, the presence of environmental gradients and the continuous availability of water. Principles applicable to microbial ecology reflect not only their population ecology and physiological ecology, but also their broad versatility and quantitative importance in the biosphere as biogeochemical catalysts and capacity for rapid physiological and evolutionary responses.

  11. Ecology, Microbial

    SciTech Connect

    Konopka, Allan

    2009-05-15

    Microbial ecology is a relatively young discipline within the field of microbiology. Its modern history spans just the past 60 years, and the field is defined by its emphasis on understanding the interactions of microbes with their environment, rather than their behavior under artificial laboratory conditions. Because microbes are ubiquitous, microbial ecologists study a broad diversity of habitats that range from aquatic to terrestrial to plant- or animal-associated. This has made it a challenge to identify unifying principles within the field. One approach is to recognize that although the activity of microbes in nature have effects at the macroscale, they interact with their physical, chemical and biological milieu at a scale of micrometers. At this scale, several different microbial ecosystems can be defined, based upon association with particles, the presence of environmental gradients and the continuous availability of water. Principles applicable to microbial ecology reflect not only their population ecology and physiological ecology, but also their broad versatility and quantitative importance in the biosphere as biogeochemical catalysts and capacity for rapid physiological and evolutionary responses.

  12. An Investigation into the Prevalence of Ecological Misconceptions in Upper Secondary Students and Implications for Pre-Service Teacher Education

    ERIC Educational Resources Information Center

    Butler, J.; Mooney Simmie, G.; O'Grady, A.

    2015-01-01

    Students' and teachers' misconceptions are an international concern among researchers in science education; they influence how students learn and teachers' teach knowledge and are a hindrance in the acquisition of accurate knowledge. This paper reports on a literature synthesis of existing research about ecological misconceptions. One means of…

  13. The ecological response of Carex lasiocarpa community in the Riparian Wetlands to the environmental gradient of water depth in Sanjiang Plain, Northeast China.

    PubMed

    Luan, Zhaoqing; Wang, Zhongxin; Yan, Dandan; Liu, Guihua; Xu, Yingying

    2013-01-01

    The response of Carex lasiocarpa in riparian wetlands in Sanjiang Plain to the environmental gradient of water depth was analyzed by using the Gaussian Model based on the biomass and average height data, and the ecological water-depth amplitude of Carex lasiocarpa was derived. The results indicated that the optimum ecological water-depth amplitude of Carex lasiocarpa based on biomass was [13.45 cm, 29.78 cm], while the optimum ecological water-depth amplitude of Carex lasiocarpa based on average height was [2.31 cm, 40.11 cm]. The intersection of the ecological water-depth amplitudes based on biomass and height confirmed that the optimum ecological water-depth amplitude of Carex lasiocarpa was [13.45 cm, 29.78 cm] and the optimist growing water-depth of Carex lasiocarpa was 21.4 cm. The TWINSPAN, a polythetic and divisive classification tool, was used to classify the wetland ecological series into 6 associations. Result of TWINSPAN matrix classification reflected an obvious environmental gradient in these associations: water-depth gradient. The relation of biodiversity of Carex lasiocarpa community and water depth was determined by calculating the diversity index of each association.

  14. Investigation of the Strawberry Acute Cold Response through Transcriptome Sampling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cultivated strawberry (Fragaria xananassa) is a valuable perennial crop, yet in most growing regions cold temperature stress can dramatically impinge on fresh fruit production. In the interest of long-term crop improvement it is important to understand the molecular response of strawberry to cold, a...

  15. Adaptive Patterns of Stress Responsivity: A Preliminary Investigation

    ERIC Educational Resources Information Center

    Del Giudice, Marco; Hinnant, J. Benjamin; Ellis, Bruce J.; El-Sheikh, Mona

    2012-01-01

    The adaptive calibration model (ACM) is an evolutionary-developmental theory of individual differences in stress responsivity. In this article, we tested some key predictions of the ACM in a middle childhood sample (N = 256). Measures of autonomic nervous system activity across the sympathetic and parasympathetic branches validated the 4-pattern…

  16. Helping Children with Emotional Difficulties: A Response to Intervention Investigation

    ERIC Educational Resources Information Center

    Pearce, Lee R.

    2009-01-01

    This article describes a Response to Intervention (RTI) model of service delivery implemented within a rural elementary school for students in kindergarten through fifth grade experiencing significant emotional and behavioral difficulties. A multi-tiered model is presented that includes school wide interventions in Tier 1, as well as a six…

  17. "Yo Soy Indígena": Identifying and Using Traditional Ecological Knowledge (TEK) to Make the Teaching of Science Culturally Responsive for Maya Girls

    ERIC Educational Resources Information Center

    Hamlin, Maria L.

    2013-01-01

    This study examines how traditional ecological knowledge--TEK--can be identified and utilized to create culturally responsive science learning opportunities for Maya girls from a community in the Guatemalan highlands. Maya girls are situated in a complex socio-historical and political context rooted in racism and sexism. This study contextualizes…

  18. Ecological controls on water-cycle response to climate variability in deserts.

    PubMed

    Scanlon, B R; Levitt, D G; Reedy, R C; Keese, K E; Sully, M J

    2005-04-26

    The impact of climate variability on the water cycle in desert ecosystems is controlled by biospheric feedback at interannual to millennial timescales. This paper describes a unique field dataset from weighing lysimeters beneath nonvegetated and vegetated systems that unequivocally demonstrates the role of vegetation dynamics in controlling water cycle response to interannual climate variability related to El Nino southern oscillation in the Mojave Desert. Extreme El Nino winter precipitation (2.3-2.5 times normal) typical of the U.S. Southwest would be expected to increase groundwater recharge, which is critical for water resources in semiarid and arid regions. However, lysimeter data indicate that rapid increases in vegetation productivity in response to elevated winter precipitation reduced soil water storage to half of that in a nonvegetated lysimeter, thereby precluding deep drainage below the root zone that would otherwise result in groundwater recharge. Vegetation dynamics have been controlling the water cycle in interdrainage desert areas throughout the U.S. Southwest, maintaining dry soil conditions and upward soil water flow since the last glacial period (10,000-15,000 yr ago), as shown by soil water chloride accumulations. Although measurements are specific to the U.S. Southwest, correlations between satellite-based vegetation productivity and elevated precipitation related to El Nino southern oscillation indicate this model may be applicable to desert basins globally. Understanding the two-way coupling between vegetation dynamics and the water cycle is critical for predicting how climate variability influences hydrology and water resources in water-limited landscapes.

  19. Invader partitions ecological and evolutionary responses to above- and belowground herbivory.

    PubMed

    Huang, Wei; Carrillo, Juli; Ding, Jianqing; Siemann, Evan

    2012-11-01

    Interactions between above- and belowground herbivory may, affect plant performance and structure communities. Though many studies have documented interactions of invasive plants and.herbivores, none shows how above- and belowground herbivores interact to affect invasive plant performance. Here, in a common garden in China, we subjected genetically differentiated tallow trees (Triadica sebifera) from native (China) and invaded (United States) ranges to herbivory by aboveground adults and belowground larvae of a specialist beetle, Bikasha collaris. Overall, relative to plants from China, U.S. plants had greater total and aboveground mass, comparable belowground mass, lower resistance to both above- and belowground herbivory, and higher tolerance to aboveground herbivory only. Accordingly, aboveground adults had greater impacts on Chinese plants, but belowground larvae more strongly impacted U.S. plants. These results indicate that the invader may adopt an "aboveground first" strategy, allocating more resources aboveground in response to selection for increased competitive ability, which increases aboveground tolerance to herbivory. Furthermore, we found that adults facilitated larval success, and these feedbacks were stronger for U.S. plants, suggesting that aboveground feeding of adults may be associated with lower defenses and/or higher resources belowground in the invader. Therefore, plants may have evolved different responses to above- and belowground herbivory, which can affect invasion success and herbivore population dynamics. These findings may provide new insights for an effective biological control program against invasive plants.

  20. Lifestyle and Ice: The Relationship between Ecological Specialization and Response to Pleistocene Climate Change.

    PubMed

    Kašparová, Eva; Van de Putte, Anton P; Marshall, Craig; Janko, Karel

    2015-01-01

    Major climatic changes in the Pleistocene had significant effects on marine organisms and the environments in which they lived. The presence of divergent patterns of demographic history even among phylogenetically closely-related species sharing climatic changes raises questions as to the respective influence of species-specific traits on population structure. In this work we tested whether the lifestyle of Antarctic notothenioid benthic and pelagic fish species from the Southern Ocean influenced the concerted population response to Pleistocene climatic fluctuations. This was done by a comparative analysis of sequence variation at the cyt b and S7 loci in nine newly sequenced and four re-analysed species. We found that all species underwent more or less intensive changes in population size but we also found consistent differences between demographic histories of pelagic and benthic species. Contemporary pelagic populations are significantly more genetically diverse and bear traces of older demographic expansions than less diverse benthic species that show evidence of more recent population expansions. Our findings suggest that the lifestyles of different species have strong influences on their responses to the same environmental events. Our data, in conjunction with previous studies showing a constant diversification tempo of these species during the Pleistocene, support the hypothesis that Pleistocene glaciations had a smaller effect on pelagic species than on benthic species whose survival may have relied upon ephemeral refugia in shallow shelf waters. These findings suggest that the interaction between lifestyle and environmental changes should be considered in genetic analyses.

  1. Lifestyle and Ice: The Relationship between Ecological Specialization and Response to Pleistocene Climate Change

    PubMed Central

    Kašparová, Eva; Van de Putte, Anton P.; Marshall, Craig; Janko, Karel

    2015-01-01

    Major climatic changes in the Pleistocene had significant effects on marine organisms and the environments in which they lived. The presence of divergent patterns of demographic history even among phylogenetically closely-related species sharing climatic changes raises questions as to the respective influence of species-specific traits on population structure. In this work we tested whether the lifestyle of Antarctic notothenioid benthic and pelagic fish species from the Southern Ocean influenced the concerted population response to Pleistocene climatic fluctuations. This was done by a comparative analysis of sequence variation at the cyt b and S7 loci in nine newly sequenced and four re-analysed species. We found that all species underwent more or less intensive changes in population size but we also found consistent differences between demographic histories of pelagic and benthic species. Contemporary pelagic populations are significantly more genetically diverse and bear traces of older demographic expansions than less diverse benthic species that show evidence of more recent population expansions. Our findings suggest that the lifestyles of different species have strong influences on their responses to the same environmental events. Our data, in conjunction with previous studies showing a constant diversification tempo of these species during the Pleistocene, support the hypothesis that Pleistocene glaciations had a smaller effect on pelagic species than on benthic species whose survival may have relied upon ephemeral refugia in shallow shelf waters. These findings suggest that the interaction between lifestyle and environmental changes should be considered in genetic analyses. PMID:26535569

  2. Ecologically Relevant Cooling Early in Life Alters Prefledging Adrenocortical Response in Free-Living Songbirds.

    PubMed

    Lynn, Sharon E; Kern, Michael D

    In vertebrates, exposure to stressful stimuli early in development may alter the activity of the hypothalamo-pituitary-adrenal (HPA) axis, with the potential for fitness consequences later in life. For altricial species, whose young rely on their parents for food, warmth, and protection from predators, adult behavior can modify the impact of some stressors on their offspring after birth or hatching. We have shown that single bouts of cooling that normally occur when brooding females leave the nest elevate corticosterone secretion in very young free-living eastern bluebird (Sialia sialis) chicks. Thus, natural variation in maternal brooding patterns can result in differential exposure of offspring to cooling, and also to glucocorticoids, very early in development. We tested the hypothesis that exposure to repeated bouts of cooling (mimicking those that occur normally when females leave the nest) would alter the activity of the chicks' HPA axis later in life. We exposed free-living chicks to either four 18-min bouts of cooling or brooding temperatures (control) during the first week after hatching. Then, just before fledging (i.e., at least 7 d after the cooling treatments had ceased), we assessed their corticosterone responses to restraint. Repeatedly cooled chicks had a significantly lower corticosterone response to restraint than did control chicks but did not differ from controls in other measures of growth and development. Our data suggest that natural variation in maternal brooding patterns, and hence natural variation in the chicks' body temperature, can alter the activity of the HPA axis well beyond the brooding period.

  3. Ecological Genetics of Chinese Rhesus Macaque in Response to Mountain Building: All Things Are Not Equal

    PubMed Central

    Li, Qing-Qing; Wang, Yan-Qin; Murphy, Robert W.; Blair, Christopher; Wu, Shi-Fang; Yue, Bi-Song; Zhang, Ya-Ping

    2013-01-01

    Background Pliocene uplifting of the Qinghai-Tibetan Plateau (QTP) and Quaternary glaciation may have impacted the Asian biota more than any other events. Little is documented with respect to how the geological and climatological events influenced speciation as well as spatial and genetic structuring, especially in vertebrate endotherms. Macaca mulatta is the most widely distributed non-human primate. It may be the most suitable model to test hypotheses regarding the genetic consequences of orogenesis on an endotherm. Methodology and Principal Findings Using a large dataset of maternally inherited mitochondrial DNA gene sequences and nuclear microsatellite DNA data, we discovered two maternal super-haplogroups exist, one in western China and the other in eastern China. M. mulatta formed around 2.31 Ma (1.51–3.15, 95%), and divergence of the two major matrilines was estimated at 1.15 Ma (0.78–1.55, 95%). The western super-haplogroup exhibits significant geographic structure. In contrast, the eastern super-haplogroup has far greater haplotypic variability with little structure based on analyses of six variable microsatellite loci using Structure and Geneland. Analysis using Migrate detected greater gene flow from WEST to EAST than vice versa. We did not detect signals of bottlenecking in most populations. Conclusions Analyses of the nuclear and mitochondrial datasets obtained large differences in genetic patterns for M. mulatta. The difference likely reflects inheritance mechanisms of the maternally inherited mtDNA genome versus nuclear biparentally inherited STRs and male-mediated gene flow. Dramatic environmental changes may be responsible for shaping the matrilineal history of macaques. The timing of events, the formation of M. mulatta, and the divergence of the super-haplogroups, corresponds to both the uplifting of the QTP and Quaternary climatic oscillations. Orogenesis likely drove divergence of western populations in China, and Pleistocene glaciations are

  4. Ecological Response to Extreme Flow Events in Streams and Rivers: Implications of Climate Change for Aquatic Biodiversity

    NASA Astrophysics Data System (ADS)

    Hawkins, C. P.; Vander Laan, J. J.; Dhungel, S.; Tarboton, D. G.

    2014-12-01

    We used the USEPA's 2008-2009 National Rivers and Streams Assessment (NRSA) data to assess the potential sensitivity of stream biodiversity to both spatial variation in measures of extreme flow and likely changes in extreme flows associated with projected climate change. The NRSA data consisted of macroinvertebrate samples collected at 1313 reference-quality sites. We characterized the hydrologic regimes at each of these sites by developing Random Forest empirical models from long-term (≥ 20 years) daily flow records obtained from 601 gaged USGS stations. These models described spatial variation in 16 flow variables as a function of climate and watershed attributes. Three of the models characterized aspects of extreme flow: the mean number of zero-flow events per year (ZeroDays), the mean number of high-flow events per year (HighDays = number of events per year that exceed the 95th percentile of mean annual flow), and the coefficient of variation of daily flows (CV). We used these models to predict the flow attributes expected at each of the 1313 sites with ecological data. We then built additional Random Forest models that related among-site differences in stream macroinvertebrate taxonomic composition, assemblage richness, and the likelihood of observing individual taxa to the 16 measures of flow regime and other environmental predictors. At the national level, ZeroDays was an important predictor of macroinvertebrate biodiversity: richness declined as ZeroDays increased. A similar pattern was observed when analyses were restricted to lowland and plains streams. For eastern highland streams, HighDays was a better predictor of stream biodiversity than aspects of low flow: richness declined as HighDays increased. For western streams, CV was a better predictor of biodiversity than either ZeroDays or HighDays: biodiversity decreased as CV increased. Empirical models that linked flow attributes to climate change projections imply that flow regime response to climate

  5. Depth-related response of macroinvertebrates to the reversal of eutrophication in a Mediterranean lake: Implications for ecological assessment.

    PubMed

    Bazzanti, Marcello; Mastrantuono, Luciana; Pilotto, Francesca

    2017-02-01

    A better management of nutrient inflows into lakes has led to an improvement in their conditions (i.e. reversal of eutrophication) and the effects of this on macroinvertebrate communities that inhabit different lake-depth zones is largely unknown. This paper reports a comparison of macroinvertebrate communities living in the eulittoral, infralittoral and sublittoral/profundal zones of Lake Nemi (Central Italy) before and after its natural recovery from eutrophication following the deviation of domestic wastewater. The infralittoral zone responded more rapidly than the other two depth-zones to the improved ecological conditions, as shown by larger differences in community composition between the two periods. In the eulittoral sand, the combined effects of hydromorphological pressures and reversal of eutrophication hindered the biotic response. In the eulittoral and infralittoral zones, typical taxa of mesotrophic waters appeared or increased their abundances after the eutrophication reversal. Benthic invertebrate response was slower in the sublittoral/profundal zone due to deoxygenation that continued to prevail in the deepest area of the lake during summer. However, both tolerant and more sensitive taxa were collected there for the first time. After the reversal of eutrophication, the percentage of molluscan+large crustaceans increased in the infralittoral zone, whereas the oligochaete/chironomid ratio decreased in both sublittoral/profundal and infralittoral zones. Functional feeding metrics (percentages of filter-feeders, collector-gatherers, miners and scrapers/grazers) differently tracked the reversal of eutrophication in the three depth-zones probably according to the effects of the reduction of nutrients on food-web structure influencing macroinvertebrates. Biological Monitoring Working Party (BMWP) and the Average Score Per Taxon (ASPT) seemed to respond to eutrophication reversal only in the sublittoral/profundal zone, where deoxygenation plays a major role

  6. After the disaster: the hydrogeomorphic, ecological, and biological responses to the 1980 eruption of Mount St. Helens, Washington

    USGS Publications Warehouse

    Major, Jon J.; Crisafulli, Charlie; Bishop, John

    2009-01-01

    The 1980 eruption of Mount St. Helens caused instantaneous landscape disturbance on a grand scale. On 18 May 1980, an ensemble of volcanic processes, including a debris avalanche, a directed pyroclastic density current, voluminous lahars, and widespread tephra fall, abruptly altered landscape hydrology and geomorphology, and created distinctive disturbance zones having varying impacts on regional biota. Response to the geological and ecological disturbances has been varied and complex. In general, eruption-induced alterations in landscape hydrology and geomorphology led to enhanced stormflow discharge and sediment transport. Although the hydrological response to landscape perturbation has diminished, enhanced sediment transport persists in some basins. In the nearly 30 years since the eruption, 350 million (metric) tons of suspended sediment has been delivered from the Toutle River watershed to the Cowlitz River (roughly 40 times the average annual preeruption suspended-sediment discharge of the Columbia River). Such prodigious sediment loading has wreaked considerable socioeconomic havoc, causing significant channel aggradation and loss of flood conveyance capacity. Significant and ongoing engineering efforts have been required to mitigate these problems. The overall biological evolution of the eruption-impacted landscape can be viewed in terms of a framework of survivor legacies. Despite appearances to the contrary, a surprising number of species survived the eruption, even in the most heavily devastated areas. With time, survivor “hotspots” have coalesced into larger patches, and have served as stepping stones for immigrant colonization. The importance of biological legacies will diminish with time, but the intertwined trajectories of geophysical and biological successions will influence the geological and biological responses to the 1980 eruption for decades to come.

  7. The response of relatives to medicolegal investigations and forensic autopsy.

    PubMed

    Plattner, Thomas; Scheurer, Eva; Zollinger, Ulrich

    2002-12-01

    Relatives of deceased persons, on whose body a forensic autopsy had been performed at the Institute of Forensic Science, Bern, Switzerland, were interrogated by a questionnaire. The aim was to investigate the attitude of relatives toward medicolegal investigation procedures in general and toward forensic autopsy in particular. A great majority of the relatives showed a positive or indifferent attitude toward a forensic autopsy. They showed a great interest in autopsy results and wished to be informed. It was concluded that information given before the autopsy is important for better understanding and can, if properly given, improve the relatives' acceptance and collaboration regarding forensic investigations. By contrast, a lack of information before the autopsy and about the autopsy results can cause further suffering on behalf of the bereaved. A forensic autopsy can be of great benefit for relatives and can help them to cope with a tragic loss.

  8. Dependence of the results of ecological-epidemic investigation of influenza A(H1N1) on immunity

    NASA Astrophysics Data System (ADS)

    Fathudinova, Mohinav; Alimova, Barno; Rahimova, Halima

    2016-07-01

    This report presents the results of ecology-epidemical and immunological researches influ-enza virus A (H1 N1) and acute respiratory infection in Dushanbe from 2011 till 2015. The received results epidemiological and immunological analysis showed us, that last years has been changed not only characteristics of influenza epidemic, but it can not be notice the low-er of intensively of the collective immunity to actual versions influenza viruses A and B

  9. The effects of climate downscaling technique and observational data set on modeled ecological responses.

    PubMed

    Pourmokhtarian, Afshin; Driscoll, Charles T; Campbell, John L; Hayhoe, Katharine; Stoner, Anne M K

    2016-07-01

    Assessments of future climate change impacts on ecosystems typically rely on multiple climate model projections, but often utilize only one downscaling approach trained on one set of observations. Here, we explore the extent to which modeled biogeochemical responses to changing climate are affected by the selection of the climate downscaling method and training observations used at the montane landscape of the Hubbard Brook Experimental Forest, New Hampshire, USA. We evaluated three downscaling methods: the delta method (or the change factor method), monthly quantile mapping (Bias Correction-Spatial Disaggregation, or BCSD), and daily quantile regression (Asynchronous Regional Regression Model, or ARRM). Additionally, we trained outputs from four atmosphere-ocean general circulation models (AOGCMs) (CCSM3, HadCM3, PCM, and GFDL-CM2.1) driven by higher (A1fi) and lower (B1) future emissions scenarios on two sets of observations (1/8º resolution grid vs. individual weather station) to generate the high-resolution climate input for the forest biogeochemical model PnET-BGC (eight ensembles of six runs).The choice of downscaling approach and spatial resolution of the observations used to train the downscaling model impacted modeled soil moisture and streamflow, which in turn affected forest growth, net N mineralization, net soil nitrification, and stream chemistry. All three downscaling methods were highly sensitive to the observations used, resulting in projections that were significantly different between station-based and grid-based observations. The choice of downscaling method also slightly affected the results, however not as much as the choice of observations. Using spatially smoothed gridded observations and/or methods that do not resolve sub-monthly shifts in the distribution of temperature and/or precipitation can produce biased results in model applications run at greater temporal and/or spatial resolutions. These results underscore the importance of

  10. Forest response to CO{sub 2} enrichment: Physiology and ecology of loblolly pine

    SciTech Connect

    Strain, B.R.; Thomas, R.B.

    1997-03-10

    This report covers the results of a long-term project with the primary objective of developing and testing hypotheses on the environmental and physiological controls of loblolly pine response to atmospheric CO{sub 2} enrichment. Earlier research under DOE funding had provided information from loblolly pine and other plant species which allowed the development of specific hypotheses. Phase 1 of this research was a two year pot study of loblolly seedlings to determine the interaction of CO{sub 2} enrichment with soil nutrition. Phase 2 began with the enrichment of loblolly seedlings being grown in the ground, rather than pots, and continued through December 1995. Phase 3 began in April 1994 with the enrichment of undisturbed Piedmont North Carolina old field undergoing succession, including herbaceous annual plants, perennial grasses, and loblolly pine tree seedlings. Phase 3 was designed to gather preliminary information on a regenerating loblolly forest to be used for the development of hypotheses and measurement techniques for a long-term Free Air CO{sub 2} Enrichment (FACE) study of regenerating forest in Duke Forest.

  11. Demographic, ecological, and physiological responses of ringed seals to an abrupt decline in sea ice availability

    PubMed Central

    Young, Brent G.; Yurkowski, David J.; Anderson, Randi; Willing, Cornelia; Nielsen, Ole

    2017-01-01

    To assess whether demographic declines of Arctic species at the southern limit of their range will be gradual or punctuated, we compared large-scale environmental patterns including sea ice dynamics to ringed seal (Pusa hispida) reproduction, body condition, recruitment, and stress in Hudson Bay from 2003 to 2013. Aerial surveys suggested a gradual decline in seal density from 1995 to 2013, with the lowest density occurring in 2013. Body condition decreased and stress (cortisol) increased over time in relation to longer open water periods. The 2010 open water period in Hudson Bay coincided with extremes in large-scale atmospheric patterns (North Atlantic Oscillation, Arctic Oscillation, El Nino-Southern Oscillation) resulting in the earliest spring breakup and the latest ice formation on record. The warming event was coincident with high stress level, low ovulation rate, low pregnancy rate, few pups in the Inuit harvest, and observations of sick seals. Results provide evidence of changes in the condition of Arctic marine mammals in relation to climate mediated sea ice dynamics. We conclude that although negative demographic responses of Hudson Bay seals are occurring gradually with diminishing sea ice, a recent episodic environmental event played a significant role in a punctuated population decline. PMID:28168119

  12. Analysis of nutrient transport and ecological response in Honghu Lake, China by using a mathematical model.

    PubMed

    Zhang, Ting; Ban, Xuan; Wang, Xuelei; Cai, Xiaobin; Li, Enhua; Wang, Zhi; Yang, Chao; Zhang, Qing; Lu, Xiaorong

    2017-01-01

    A two-dimensional (2D) water quality model was established to determine the response of water quality variables and submerged aquatic vegetation biomass to load reduction from watershed inflows and enclosure aquaculture in Honghu Lake in China. Results showed that the total nitrogen (TN) and total phosphorus (TP) loads from upstream discharge were the major external loads in the lake, accounting for 70% and 63% of the total loads, respectively. Scenario simulation results indicated that 93.2% of the lake area in summer (August) and 89.5% in autumn (November) could reach the protective targets (TN<1.0mg/L) under 50% reduction of inflow TN loads. Meanwhile, 58.7% of the lake area in summer and 63.1% in autumn could reach the protective targets (TP<0.05mg/L) under 50% reduction of aquaculture areas. The mass budget results of TN and TP showed that TP immobilisation was larger than TN immobilisation. The immobilisations for TN and TP from July to September were higher than those of other months under the combined impacts of increasing runoff during the wet period, phytoplankton bloom and water residence time. The 2D water quality model provided a relevant example for assessing the effects of runoff and aquaculture activities and served as scientific support for lake management to improve water quality in large shallow macrophytic lakes.

  13. Administrative Ecology

    ERIC Educational Resources Information Center

    McGarity, Augustus C., III; Maulding, Wanda

    2007-01-01

    This article discusses how all four facets of administrative ecology help dispel the claims about the "impossibility" of the superintendency. These are personal ecology, professional ecology, organizational ecology, and community ecology. Using today's superintendency as an administrative platform, current literature describes a preponderance of…

  14. Extreme ecological response of a seabird community to unprecedented sea ice cover.

    PubMed

    Barbraud, Christophe; Delord, Karine; Weimerskirch, Henri

    2015-05-01

    Climate change has been predicted to reduce Antarctic sea ice but, instead, sea ice surrounding Antarctica has expanded over the past 30 years, albeit with contrasted regional changes. Here we report a recent extreme event in sea ice conditions in East Antarctica and investigate its consequences on a seabird community. In early 2014, the Dumont d'Urville Sea experienced the highest magnitude sea ice cover (76.8%) event on record (1982-2013: range 11.3-65.3%; mean±95% confidence interval: 27.7% (23.1-32.2%)). Catastrophic effects were detected in the breeding output of all sympatric seabird species, with a total failure for two species. These results provide a new view crucial to predictive models of species abundance and distribution as to how extreme sea ice events might impact an entire community of top predators in polar marine ecosystems in a context of expanding sea ice in eastern Antarctica.

  15. Developmental models for estimating ecological responses to environmental variability: structural, parametric, and experimental issues

    PubMed Central

    Moore, Julia L

    2014-01-01

    Developmental models that account for the metabolic effect of temperature variability on poikilotherms, such as degree-day models, have been widely used to study organism emergence, range and development, particularly in agricultural and vector-borne disease contexts. Though simple and easy to use, structural and parametric issues can influence the outputs of such models, often substantially. Because the underlying assumptions and limitations of these models have rarely been considered, this paper reviews the structural, parametric, and experimental issues that arise when using degree-day models, including the implications of particular structural or parametric choices, as well as assumptions that underlie commonly used models. Linear and nonlinear developmental functions are compared, as are common methods used to incorporate temperature thresholds and calculate daily degree-days. Substantial differences in predicted emergence time arose when using linear vs. non-linear developmental functions to model the emergence time in a model organism. The optimal method for calculating degree-days depends upon where key temperature threshold parameters fall relative to the daily minimum and maximum temperatures, as well as the shape of the daily temperature curve. No method is shown to be universally superior, though one commonly used method, the daily average method, consistently provides accurate results. The sensitivity of model projections to these methodological issues highlights the need to make structural and parametric selections based on a careful consideration of the specific biological response of the organism under study, and the specific temperature conditions of the geographic regions of interest. When degree-day model limitations are considered and model assumptions met, the models can be a powerful tool for studying temperature-dependent development. PMID:24443079

  16. Models and Methods to Investigate Acute Stress Responses in Cattle

    PubMed Central

    Chen, Yi; Arsenault, Ryan; Napper, Scott; Griebel, Philip

    2015-01-01

    There is a growing appreciation within the livestock industry and throughout society that animal stress is an important issue that must be addressed. With implications for animal health, well-being, and productivity, minimizing animal stress through improved animal management procedures and/or selective breeding is becoming a priority. Effective management of stress, however, depends on the ability to identify and quantify the effects of various stressors and determine if individual or combined stressors have distinct biological effects. Furthermore, it is critical to determine the duration of stress-induced biological effects if we are to understand how stress alters animal production and disease susceptibility. Common stress models used to evaluate both psychological and physical stressors in cattle are reviewed. We identify some of the major gaps in our knowledge regarding responses to specific stressors and propose more integrated methodologies and approaches to measuring these responses. These approaches are based on an increased knowledge of both the metabolic and immune effects of stress. Finally, we speculate on how these findings may impact animal agriculture, as well as the potential application of large animal models to understanding human stress. PMID:26633525

  17. Nutritional ecology of a parasitic wasp: food source affects gustatory response, metabolic utilization, and survivorship.

    PubMed

    Williams, Livy; Roane, Timberley M

    2007-12-01

    The success of biological control is partly mediated by the longevity and reproductive success of beneficial insects. Availability of nectar and honeydew can improve the nutrition of parasitic insects, and thereby increase their longevity and realized fecundity. The egg parasitoid, Anaphes iole, showed strong gustatory perception of trehalulose, a carbohydrate found in homopteran honeydew. Chromatographic analysis demonstrated that enzymatic hydrolysis of sucrose, a common nectar sugar, proceeded at a faster rate than that of melezitose, a sugar common in aphid honeydew. A long-term bioassay showed that longevity was greater at 20 degrees C than at 27 degrees C, and at both temperatures survival was generally greatest for wasps provisioned with the three major nectar sugars, sucrose, glucose, and fructose. Patterns of food acceptance and utilization showed that A. iole accepted and utilized a broad range of sugars found in nature, including those found in nectar as well as honeydew. Glucose, fructose, and several oligosaccharides composed of these monosaccharide units appear to be more suitable for A. iole than other sugars tested. Evidence suggests that individual fitness benefits afforded by food sources are important for a time-limited parasitoid, and that continued investigations on the interface between nutrition and biological control are warranted for A. iole.

  18. BIOLOGICAL RESPONSES OF THE SEA URCHIN, ARBACIA PUNTULATA, TO LEAD CONTAMINATION FOR AN ESTUARINE ECOLOGICAL RISK ASSESSMENT

    EPA Science Inventory

    An estuarine ecological risk assessment for the Portsmouth Naval Shipyard (PNS) Kittery, ME, was conducted utilizing the U.S. EPA's Framework for Ecological Risk Assessment (ERA). As part of the analysis phase of the ERA, laboratory studies were conducted to develop quantitative ...

  19. Response to Ecological Risk Assessment Forum Request for Information on the Benefits of PCB Congener-Specific Analyses

    EPA Science Inventory

    In August, 2001, the Ecological Risk Assessment Forum (ERAF) submitted a formal question to the Ecological Risk Assessment Support Center (ERASC) on the benefits of evaluating PCB congeners in environmental samples. This question was developed by ERAF members Bruce Duncan and Cla...

  20. 45 CFR 94.4 - Institutional responsibility regarding conflicting interests of investigators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Institutional responsibility regarding conflicting... ADMINISTRATION RESPONSIBLE PROSPECTIVE CONTRACTORS § 94.4 Institutional responsibility regarding conflicting... Investigator's reporting responsibilities, and of these regulations. If the Institution carries out the...

  1. Study on the Response of Ecological Capacity to Land-Use/Cover Change in Wuhan City: A Remote Sensing and GIS Based Approach

    PubMed Central

    Wang, Ying; Li, Xiangmei

    2014-01-01

    This research examined the spatiotemporal patterns of land-use/cover and the dynamics of ecological capacity in response to land-use/cover change in Wuhan city, central China. The data were derived from five years' remote-sensed images, that is, 1990, 1995, 2000, 2005, and 2010. This paper used an integrated approach of remote sensing and GIS techniques, ecological capacity and the bilateral dynamic degree models. The results are as follows. (1) From 1990 to 2010, remarkable changes in land-use/cover have occurred within the studied area, and the most prominent characteristics of the changes were continuous decline of arable land and rapid increase of built-up land. (2) The total ecological capacity dropped from 450.55 × 104 ghm2 in 1990 to 447.35 × 104 ghm2 in 2010. The eastern, western, and southern parts had higher ecological capacity whereas the northwestern hilly areas and the central district had lower ecological capacity. (3) Due to the conversion from arable land to built-up land, the ecological capacity losses during 1990–1995, 1995–2000, 2000–2005, and 2005–2010 were 155.52 × 102 ghm2, 114.12 × 102 ghm2, 455.48 × 102 ghm2, and 325.26 × 102 ghm2, respectively. The study would contribute to better understanding of the effects of land-use dynamics and the evolution of ecological capacity, which can provide scientific basis for land management and environment protection. PMID:25258734

  2. Study on the response of ecological capacity to land-use/cover change in Wuhan city: a remote sensing and GIS based approach.

    PubMed

    Wang, Ying; Li, Xiangmei; Li, Jiangfeng

    2014-01-01

    This research examined the spatiotemporal patterns of land-use/cover and the dynamics of ecological capacity in response to land-use/cover change in Wuhan city, central China. The data were derived from five years' remote-sensed images, that is, 1990, 1995, 2000, 2005, and 2010. This paper used an integrated approach of remote sensing and GIS techniques, ecological capacity and the bilateral dynamic degree models. The results are as follows. (1) From 1990 to 2010, remarkable changes in land-use/cover have occurred within the studied area, and the most prominent characteristics of the changes were continuous decline of arable land and rapid increase of built-up land. (2) The total ecological capacity dropped from 450.55 × 10(4) ghm(2) in 1990 to 447.35 × 10(4) ghm(2) in 2010. The eastern, western, and southern parts had higher ecological capacity whereas the northwestern hilly areas and the central district had lower ecological capacity. (3) Due to the conversion from arable land to built-up land, the ecological capacity losses during 1990-1995, 1995-2000, 2000-2005, and 2005-2010 were 155.52 × 10(2) ghm(2), 114.12 × 10(2) ghm(2), 455.48 × 10(2) ghm(2), and 325.26 × 10(2) ghm(2), respectively. The study would contribute to better understanding of the effects of land-use dynamics and the evolution of ecological capacity, which can provide scientific basis for land management and environment protection.

  3. Responses to colour and host odour cues in three cereal pest species, in the context of ecology and control.

    PubMed

    Arnold, S E J; Stevenson, P C; Belmain, S R

    2015-08-01

    Many insects show a greater attraction to multimodal cues, e.g. odour and colour combined, than to either cue alone. Despite the potential to apply the knowledge to improve control strategies, studies of multiple stimuli have not been undertaken for stored product pest insects. We tested orientation towards a food odour (crushed white maize) in combination with a colour cue (coloured paper with different surface spectral reflectance properties) in three storage pest beetle species, using motion tracking to monitor their behaviour. While the maize weevil, Sitophilus zeamais (Motsch.), showed attraction to both odour and colour stimuli, particularly to both cues in combination, this was not observed in the bostrichid pests Rhyzopertha dominica (F.) (lesser grain borer) or Prostephanus truncatus (Horn) (larger grain borer). The yellow stimulus was particularly attractive to S. zeamais, and control experiments showed that this was neither a result of the insects moving towards darker-coloured areas of the arena, nor their being repelled by optical brighteners in white paper. Visual stimuli may play a role in location of host material by S. zeamais, and can be used to inform trap design for the control or monitoring of maize weevils. The lack of visual responses by the two grain borers is likely to relate to their different host-seeking behaviours and ecological background, which should be taken into account when devising control methods.

  4. Tuning the Poisson's Ratio of Biomaterials for Investigating Cellular Response

    PubMed Central

    Meggs, Kyle; Qu, Xin; Chen, Shaochen

    2013-01-01

    Cells sense and respond to mechanical forces, regardless of whether the source is from a normal tissue matrix, an adjacent cell or a synthetic substrate. In recent years, cell response to surface rigidity has been extensively studied by modulating the elastic modulus of poly(ethylene glycol) (PEG)-based hydrogels. In the context of biomaterials, Poisson's ratio, another fundamental material property parameter has not been explored, primarily because of challenges involved in tuning the Poisson's ratio in biological scaffolds. Two-photon polymerization is used to fabricate suspended web structures that exhibit positive and negative Poisson's ratio (NPR), based on analytical models. NPR webs demonstrate biaxial expansion/compression behavior, as one or multiple cells apply local forces and move the structures. Unusual cell division on NPR structures is also demonstrated. This methodology can be used to tune the Poisson's ratio of several photocurable biomaterials and could have potential implications in the field of mechanobiology. PMID:24076754

  5. Investigations of human EEG response to viewing fractal patterns.

    PubMed

    Hagerhall, Caroline M; Laike, Thorbjörn; Taylor, Richard P; Küller, Marianne; Küller, Rikard; Martin, Theodore P

    2008-01-01

    Owing to the prevalence of fractal patterns in natural scenery and their growing impact on cultures around the world, fractals constitute a common feature of our daily visual experiences, raising an important question: what responses do fractals induce in the observer? We monitored subjects' EEG while they were viewing fractals with different fractal dimensions, and the results show that significant effects could be found in the EEG even by employing relatively simple silhouette images. Patterns with a fractal dimension of 1.3 elicited the most interesting EEG, with the highest alpha in the frontal lobes but also the highest beta in the parietal area, pointing to a complicated interplay between different parts of the brain when experiencing this pattern.

  6. New Modeling Approaches to Investigate Cell Signaling in Radiation Response

    NASA Technical Reports Server (NTRS)

    Plante, Ianik; Cucinotta, Francis A.; Ponomarev, Artem L.

    2011-01-01

    Ionizing radiation damages individual cells and tissues leading to harmful biological effects. Among many radiation-induced lesions, DNA double-strand breaks (DSB) are considered the key precursors of most early and late effects [1] leading to direct mutation or aberrant signal transduction processes. In response to damage, a flow of information is communicated to cells not directly hit by the radiation through signal transduction pathways [2]. Non-targeted effects (NTE), which includes bystander effects and genomic instability in the progeny of irradiated cells and tissues, may be particularly important for space radiation risk assessment [1], because astronauts are exposed to a low fluence of heavy ions and only a small fraction of cells are traversed by an ion. NTE may also have important consequences clinical radiotherapy [3]. In the recent years, new simulation tools and modeling approaches have become available to study the tissue response to radiation. The simulation of signal transduction pathways require many elements such as detailed track structure calculations, a tissue or cell culture model, knowledge of biochemical pathways and Brownian Dynamics (BD) propagators of the signaling molecules in their micro-environment. Recently, the Monte-Carlo simulation code of radiation track structure RITRACKS was used for micro and nano-dosimetry calculations [4]. RITRACKS will be used to calculate the fraction of cells traversed by an ion and delta-rays and the energy deposited in cells in a tissue model. RITRACKS also simulates the formation of chemical species by the radiolysis of water [5], notably the .OH radical. This molecule is implicated in DNA damage and in the activation of the transforming growth factor beta (TGF), a signaling molecule involved in NTE. BD algorithms for a particle near a membrane comprising receptors were also developed and will be used to simulate trajectories of signaling molecules in the micro-environment and characterize autocrine

  7. Investigation of rice proteomic change in response to microgravity

    NASA Astrophysics Data System (ADS)

    Sun, Weining

    Gravity is one of the environmental factors that control development and growth of plants. Plant cells which are not part of specialized tissues such as the root columella can also sense gravity. Space environment, such as space shuttle missions, space labortories and space stations, etc. provide unique oppotunities to study the microgravity response of plant. During the Shenzhou 8 mission in November 2011, we cultured rice cali on the spaceship and the samples were fixed 4 days after launch. The flying samples in the static position (micro g, mug) and in the centrifuge which provide 1 g force to mimic the 1 g gravity in space, were recovered and the proteome changes were analyzed by iTRAQ. In total, 4840 proteins were identified, including 2085 proteins with function annotation by GO analysis. 431 proteins were changed >1.5 fold in space µg /ground group, including 179 up-regulated proteins and down-regulated 252 proteins. 321 proteins were changed >1.5 fold in space muµg / space 1 g group, among which 205 proteins were the same differentially expressed proteins responsive to microgravity. Enrichment of the differnetially expressed proteins by GO analysis showed that the ARF GTPase activity regulation proteins were enriched when compared the space µg with space 1 g sample, whereas the nucleic acid binding and DNA damage repairing proteins were enriched when compared the space µg and ground sample. Microscopic comparison of the rice cali showed that the space grown cells are more uniformed in size and proliferation, suggesting that cell proliferation pattern was changed in space microgravity conditions.

  8. Electric field response in bilayer graphene: Ab initio investigation

    NASA Astrophysics Data System (ADS)

    Mori, Yutaro; Minamitani, Emi; Ando, Yasunobu; Kasamatsu, Shusuke; Watanabe, Satoshi

    2016-11-01

    Stimulated by quantum capacitance measurements, we have investigated the electric properties of bilayer graphene (BLG) with carrier doping under an external electric field using ab initio calculations. We found that the relative permittivity of BLG depends weakly on the applied electric field, and that the BLG can be regarded as a dielectric material rather than a pair of metallic films. We also found that carrier doping affects the band gap of BLG under electric fields, although carrier doping has a much smaller effect on the band gap and density of states than the application of electric fields.

  9. Birds in Anthropogenic Landscapes: The Responses of Ecological Groups to Forest Loss in the Brazilian Atlantic Forest

    PubMed Central

    Morante-Filho, José Carlos; Rhodes, Jonathan

    2015-01-01

    Habitat loss is the dominant threat to biodiversity and ecosystem functioning in terrestrial environments. In this study, we used an a priori classification of bird species based on their dependence on native forest habitats (forest-specialist and habitat generalists) and specific food resources (frugivores and insectivores) to evaluate their responses to forest cover reduction in landscapes in the Brazilian Atlantic Forest. From the patch-landscapes approach, we delimited 40 forest sites, and quantified the percentage of native forest within a 2 km radius around the center of each site (from 6 - 85%). At each site, we sampled birds using the point-count method. We used a null model, a generalized linear model and a four-parameter logistic model to evaluate the relationship between richness and abundance of the bird groups and the native forest amount. A piecewise model was then used to determine the threshold value for bird groups that showed nonlinear responses. The richness and abundance of the bird community as a whole were not affected by changes in forest cover in this region. However, a decrease in forest cover had a negative effect on diversity of forest-specialist, frugivorous and insectivorous birds, and a positive effect on generalist birds. The species richness and abundance of all ecological groups were nonlinearly related to forest reduction and showed similar threshold values, i.e., there were abrupt changes in individuals and species numbers when forest amount was less than approximately 50%. Forest sites within landscapes with forest cover that was less than 50% contained a different bird species composition than more extensively forested sites and had fewer forest-specialist species and higher beta-diversity. Our study demonstrated the pervasive effect of forest reduction on bird communities in one of the most important hotspots for bird conservation and shows that many vulnerable species require extensive forest cover to persist. PMID:26083245

  10. Birds in Anthropogenic Landscapes: The Responses of Ecological Groups to Forest Loss in the Brazilian Atlantic Forest.

    PubMed

    Morante-Filho, José Carlos; Faria, Deborah; Mariano-Neto, Eduardo; Rhodes, Jonathan

    2015-01-01

    Habitat loss is the dominant threat to biodiversity and ecosystem functioning in terrestrial environments. In this study, we used an a priori classification of bird species based on their dependence on native forest habitats (forest-specialist and habitat generalists) and specific food resources (frugivores and insectivores) to evaluate their responses to forest cover reduction in landscapes in the Brazilian Atlantic Forest. From the patch-landscapes approach, we delimited 40 forest sites, and quantified the percentage of native forest within a 2 km radius around the center of each site (from 6 - 85%). At each site, we sampled birds using the point-count method. We used a null model, a generalized linear model and a four-parameter logistic model to evaluate the relationship between richness and abundance of the bird groups and the native forest amount. A piecewise model was then used to determine the threshold value for bird groups that showed nonlinear responses. The richness and abundance of the bird community as a whole were not affected by changes in forest cover in this region. However, a decrease in forest cover had a negative effect on diversity of forest-specialist, frugivorous and insectivorous birds, and a positive effect on generalist birds. The species richness and abundance of all ecological groups were nonlinearly related to forest reduction and showed similar threshold values, i.e., there were abrupt changes in individuals and species numbers when forest amount was less than approximately 50%. Forest sites within landscapes with forest cover that was less than 50% contained a different bird species composition than more extensively forested sites and had fewer forest-specialist species and higher beta-diversity. Our study demonstrated the pervasive effect of forest reduction on bird communities in one of the most important hotspots for bird conservation and shows that many vulnerable species require extensive forest cover to persist.

  11. A predictive model of avian natal dispersal distance provides prior information for investigating response to landscape change.

    PubMed

    Garrard, Georgia E; McCarthy, Michael A; Vesk, Peter A; Radford, James Q; Bennett, Andrew F

    2012-01-01

    1. Informative Bayesian priors can improve the precision of estimates in ecological studies or estimate parameters for which little or no information is available. While Bayesian analyses are becoming more popular in ecology, the use of strongly informative priors remains rare, perhaps because examples of informative priors are not readily available in the published literature. 2. Dispersal distance is an important ecological parameter, but is difficult to measure and estimates are scarce. General models that provide informative prior estimates of dispersal distances will therefore be valuable. 3. Using a world-wide data set on birds, we develop a predictive model of median natal dispersal distance that includes body mass, wingspan, sex and feeding guild. This model predicts median dispersal distance well when using the fitted data and an independent test data set, explaining up to 53% of the variation. 4. Using this model, we predict a priori estimates of median dispersal distance for 57 woodland-dependent bird species in northern Victoria, Australia. These estimates are then used to investigate the relationship between dispersal ability and vulnerability to landscape-scale changes in habitat cover and fragmentation. 5. We find evidence that woodland bird species with poor predicted dispersal ability are more vulnerable to habitat fragmentation than those species with longer predicted dispersal distances, thus improving the understanding of this important phenomenon. 6. The value of constructing informative priors from existing information is also demonstrated. When used as informative priors for four example species, predicted dispersal distances reduced the 95% credible intervals of posterior estimates of dispersal distance by 8-19%. Further, should we have wished to collect information on avian dispersal distances and relate it to species' responses to habitat loss and fragmentation, data from 221 individuals across 57 species would have been required to obtain

  12. The freedom and the responsibility of investigator-initiated research.

    PubMed

    Brown, G E

    1994-06-01

    Since World War II, scientific inquiry and research have been based on the premise that the more investigator-initiated research is conducted, the more automatic benefits for society are created. It is finally becoming clear to many that this belief is neither rational, true, nor healthy; in short, we as a society have been indiscriminately embracing whatever we are able to do instead of doing those things that will take society where it needs to go. Trickle-down science and technology do not work any better than the famous trickle-down economics worked. The author praises the accomplishments of scientific research but gives several examples, including those involving health care, of the widening gap that unguided science and technology have helped to foster between the advantaged and disadvantaged populations in most of the world, including the United States. He proposes that while investigator-initiated research is crucial, it must be done in the context of strategic paths and a set of values that direct it toward achieving the goals for the nation and the world that must be reached if the planet and its increasing population are to survive. He emphasizes that such strategic paths provide the compass; they do not control the journey. For example, he is not saying that biomedical researchers should be directed to specific experiments, but rather that as researchers they must realize the moving from remediation to prevention is a primary national and international goal for human health.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Toxicity of sediments from around a North Sea oil platform: are metals or hydrocarbons responsible for ecological impacts?

    PubMed

    Grant, Alastair; Briggs, Andrew D

    2002-02-01

    Discharges of contaminated drill cuttings have caused appreciable ecological change of the benthos adjacent to many oil and gas platforms in the North Sea. Many platforms have large piles of cuttings lying beneath them and these probably present the greatest potential hazard to the environment during platform decommissioning and removal. There is, however, a lack of consensus on which aspects of drill cuttings are responsible for the adverse ecological effects. This hinders risk assessment of management options. Here we report data on the toxicity of sediments from around the North West Hutton platform to the amphipod Corophium volutator, the polychaete Arenicola marina and the Microtox" acute test system. Sediment was acutely toxic to Corophium out as far as 600 m from the platform. Sediment from 100 m from the platform remained acutely toxic to Corophium when 3% contaminated sediment was mixed with clean sediment. A 10% dilution of this sediment also inhibited Arenicola feeding almost completely. Sediment elutriates did not inhibit Microtox light output, but organics extracted by dichloromethane were very toxic. Fifteen minute EC50 values were as low as 0.25 mg ml(-1) and were strongly correlated with hydrocarbon concentrations. Metal concentrations in whole sediments were correlated with their toxicity to Corophium but the relationship was much weaker when data on dilutions were included. Except at sites immediately adjacent to the platform, metal concentrations were well below ERL values from the literature, so were too low to explain sediment toxicity. Toxicity of sediments to Corophium was closely correlated with their hydrocarbon content, even when tests on dilutions were included in the analysis. We conclude that hydrocarbons are the most significant cause of toxicity in these sediments contaminated with oil based drill cuttings and that polar organics, sulphide. ammonia and other water soluble substances are of much lower significance. Applying OSPAR

  14. Investigating the Anisotropic Scintillation Response in Organic Crystal Scintillator Detectors

    NASA Astrophysics Data System (ADS)

    Schuster, Patricia Frances

    This dissertation presents several studies that experimentally characterize the scintillation anisotropy in organic crystal scintillators. These include measurements of neutron, gamma-ray and cosmic muon interactions in anthracene, a historical benchmark among organic scintillator materials, to confirm and extend measurements previously available in the literature. The gamma-ray and muon measurements provide new experimental confirmation that no scintillation anisotropy is present in their interactions. Observations from these measurements have updated the hypothesis for the physical mechanism that is responsible for the scintillation anisotropy concluding that a relatively high dE/dx is required in order to produce a scintillation anisotropy. The directional dependence of the scintillation output in liquid and plastic materials was measured to experimentally confirm that no scintillation anisotropy correlated to detector orientation exists in amorphous materials. These observations confirm that the scintillation anisotropy is not due to an external effect on the measurement system, and that a fixed, repeating structure is required for a scintillation anisotropy. The directional dependence of the scintillation output in response to neutron interactions was measured in four stilbene crystals of various sizes and growth-methods. The scintillation anisotropy in these materials was approximately uniform, indicating that the crystal size, geometry, and growth method do not significantly impact the effect. Measurements of three additional pure crystals and two mixed crystals were made. These measurements showed that 1) the magnitude of the effect varies with energy and material, 2) the relationship between the light output and pulse shape anisotropy varies across materials, and 3) the effect in mixed materials is very complex. These measurements have informed the hypothesis of the mechanism that produces the directional dependence. By comparing the various relationships

  15. Investigating the phytohormone ethylene response pathway by chemical genetics.

    PubMed

    Lin, Lee-Chung; Chueh, Chiao-Mei; Wang, Long-Chi

    2014-01-01

    Conventional mutant screening in forward genetics research is indispensible to understand the biological operation behind any given phenotype. However, several issues, such as functional redundancy and lethality or sterility resulting from null mutations, frequently impede the functional characterization of genetic mutants. As an alternative approach, chemical screening with natural products or synthetic small molecules that act as conditional mutagens allows for identifying bioactive compounds as bioprobes to overcome the above-mentioned issues. Ethylene is the simplest olefin and is one of the major phytohormones playing crucial roles in plant physiology. Most of the current information on how ethylene works in plants came primarily from genetic studies of ethylene mutants identified by conventional genetic screening two decades ago. However, we lack a complete picture of functional interaction among components in the ethylene pathway and cross talk of ethylene with other phytohormones. Here, we describe our methodology for using chemical genetics to identify small molecules that interfere with the ethylene response. We set up a phenotype-based screening platform and a reporter gene-based system for verification of the hit compounds identified by chemical screening. We have successfully identified small molecules affecting the ethylene phenotype in etiolated seedlings and showed that a group of structurally similar compounds are novel inhibitors of ACC synthase, a rate-limiting enzyme in the ethylene biosynthesis pathway.

  16. Investigating the Responses of Human Epithelial Cells to Predatory Bacteria

    PubMed Central

    Monnappa, Ajay K.; Bari, Wasimul; Choi, Seong Yeol; Mitchell, Robert J.

    2016-01-01

    One beguiling alternative to antibiotics for treating multi-drug resistant infections are Bdellovibrio-and-like-organisms (BALOs), predatory bacteria known to attack human pathogens. Consequently, in this study, the responses from four cell lines (three human and one mouse) were characterized during an exposure to different predatory bacteria, Bdellovibrio bacteriovorus HD100, Bacteriovorus BY1 and Bacteriovorax stolpii EB1. TNF-α levels were induced in Raw 264.7 mouse macrophage cultures with each predator, but paled in comparison to those obtained with E. coli. This was true even though the latter strain was added at an 11.1-fold lower concentration (p < 0.01). Likewise, E. coli led to a significant (54%) loss in the Raw 264.7 murine macrophage viability while the predatory strains had no impact. Tests with various epithelial cells, including NuLi-1 airway, Caco2, HT29 and T84 colorectal cells, gave similar results, with E. coli inducing IL-8 production. The viabilities of the NuLi-1 and Caco-2 cells were slightly reduced (8%) when exposed to the predators, while T84 viability remained steady. In no cases did the predatory bacteria induce actin rearrangement. These results clearly demonstrate the gentle natures of predatory bacteria and their impacts on human cells. PMID:27629536

  17. Ecological Schoolyards.

    ERIC Educational Resources Information Center

    Danks, Sharon Gamson

    2000-01-01

    Presents design guidelines and organizational and site principles for creating schoolyards where students can learn about ecology. Principles for building schoolyard ecological systems are described. (GR)

  18. 33 CFR 133.23 - Investigation to determine the source and responsible party.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS § 133.23 Investigation to determine the source and...

  19. 33 CFR 133.23 - Investigation to determine the source and responsible party.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS § 133.23 Investigation to determine the source and...

  20. 33 CFR 133.23 - Investigation to determine the source and responsible party.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS § 133.23 Investigation to determine the source and...

  1. 33 CFR 133.23 - Investigation to determine the source and responsible party.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS § 133.23 Investigation to determine the source and...

  2. 33 CFR 133.23 - Investigation to determine the source and responsible party.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; STATE ACCESS § 133.23 Investigation to determine the source and...

  3. Aquatic vegetation in response to increased eutrophication and degraded light climate in Eastern Lake Taihu: Implications for lake ecological restoration

    NASA Astrophysics Data System (ADS)

    Zhang, Yunlin; Liu, Xiaohan; Qin, Boqiang; Shi, Kun; Deng, Jianming; Zhou, Yongqiang

    2016-04-01

    Terrestrial and aquatic ecosystem degradation is widely recognized as a major global environmental and development problem. Although great efforts have been made to prevent aquatic ecosystem degradation, the degree, extent and impacts of this phenomenon remain controversial and unclear, such as its driving mechanisms. Here, we present results from a 17-year field investigation (1998–2014) of water quality and a 12-year remote sensing mapping (2003–2014) of the aquatic vegetation presence frequency (VPF) in Eastern Lake Taihu, a macrophyte-dominated bay of Lake Taihu in China. In the past 17 years, nutrient concentrations and water level (WL) have significantly increased, but the Secchi disk depth (SDD) has significantly decreased. These changes were associated with increased lake eutrophication and a degraded underwater light climate that further inhibited the growth of aquatic vegetation. In Eastern Lake Taihu, increased nutrients, chlorophyll a and WL, and a decreased SDD were all significantly correlated with a decreased VPF. NH4+-N concentration and SDD/WL were the most important controlling factors for VPF. Therefore, increased anthropogenic nutrient inputs and a degraded underwater light climate surely result in a decreased VPF. These results elucidate the driving mechanism of aquatic vegetation degradation and will facilitate Lake Taihu ecological restoration.

  4. Aquatic vegetation in response to increased eutrophication and degraded light climate in Eastern Lake Taihu: Implications for lake ecological restoration

    PubMed Central

    Zhang, Yunlin; Liu, Xiaohan; Qin, Boqiang; Shi, Kun; Deng, Jianming; Zhou, Yongqiang

    2016-01-01

    Terrestrial and aquatic ecosystem degradation is widely recognized as a major global environmental and development problem. Although great efforts have been made to prevent aquatic ecosystem degradation, the degree, extent and impacts of this phenomenon remain controversial and unclear, such as its driving mechanisms. Here, we present results from a 17-year field investigation (1998–2014) of water quality and a 12-year remote sensing mapping (2003–2014) of the aquatic vegetation presence frequency (VPF) in Eastern Lake Taihu, a macrophyte-dominated bay of Lake Taihu in China. In the past 17 years, nutrient concentrations and water level (WL) have significantly increased, but the Secchi disk depth (SDD) has significantly decreased. These changes were associated with increased lake eutrophication and a degraded underwater light climate that further inhibited the growth of aquatic vegetation. In Eastern Lake Taihu, increased nutrients, chlorophyll a and WL, and a decreased SDD were all significantly correlated with a decreased VPF. NH4+-N concentration and SDD/WL were the most important controlling factors for VPF. Therefore, increased anthropogenic nutrient inputs and a degraded underwater light climate surely result in a decreased VPF. These results elucidate the driving mechanism of aquatic vegetation degradation and will facilitate Lake Taihu ecological restoration. PMID:27041062

  5. Investigating variation in the nutritional ecology and genetics of White-tailed Ptarmigan: implications for climate change

    NASA Astrophysics Data System (ADS)

    Oyler-McCance, S. J.; Stricker, C. A.; Braun, C. E.; Wann, G. T.; Aldridge, C. L.

    2010-12-01

    White-tailed Ptarmigan (Lagopus leucura) are well suited as a focal species for the study of climate change because they are adapted to cool, alpine environments that are expected to undergo unusually rapid climate change. We compared samples collected in the late 1930s, the late 1960s, and the late 2000s using molecular genetic and stable isotope methods in an effort to determine whether White-tailed Ptarmigan on Mt. Evans, Colorado have experienced recent environmental changes resulting in shifts in genetic diversity, gene frequency, and nutritional ecology. We genotyped 115 individuals spanning the three time periods using nine polymorphic microsatellite loci in our genetic analysis. These samples were also analyzed for stable carbon and nitrogen isotopic composition. We found a slight trend of lower heterozygosity through time and allelic richness values were lower in more recent times. We found no changes in allele frequencies across time periods suggesting that population sizes have not changed dramatically. Feather δ13C and δ15N values decreased significantly across time periods, whereas the range in isotope values increased consistently from the late 1930s to the later time periods. Inferred changes in the nutritional ecology of White-tailed Ptarmigan on Mt. Evans relates primarily to increased atmospheric deposition of nutrients that likely influenced foraging habits and tundra plant composition and nutritional quality. We briefly discuss similar ongoing work on the neighboring population in Rocky Mountain National Park, Colorado and tie in genetic results from across the species range.

  6. Immunohistochemical investigation of wound healing in response to fractional photothermolysis

    NASA Astrophysics Data System (ADS)

    Helbig, Doris; Bodendorf, Marc Oliver; Grunewald, Sonja; Kendler, Michael; Simon, Jan C.; Paasch, Uwe

    2009-11-01

    Despite growing clinical evidence of ablative fractional photothermolysis (AFP), little is known about the spatiotemporal molecular changes within the targeted compartments. Six subjects received three different single AFP treatments using a scanned 250 μm CO2-laser beam. Spatiotemporal changes of skin regeneration were estimated by immunohistochemical investigation (HSP70, HSP72, HSP47, TGFβ, procollagen III, CD3, CD20, and CD68) in skin samples 1 h, 3 days, and 14 days postintervention. The remodeling was uniformly started by regrowth of the epidermal compartment followed by partial to complete replacement of the microscopic ablation zones (MAZ) by newly synthesized condensed procollagen III. From day 3 to 14, the number of macrophages as well as giant cells surrounding the MAZ increased. TGFβ expression was highest 1 h to 3 days following AFP. HSP70 and HSP72 expressions were highest 3-14 days postintervention in the spinocellular layer leading to an upregulation of HSP47. AFP performed by a scanned CO2-laser results in an early epidermal remodeling, which is followed by a dermal remodeling leading to a replacement of the MAZ with newly synthesized (pro)-collagen. During this, an inflammatory infiltrate with CD3+ and CD20+ cells surrounds the MAZ. The count of macrophages and giant cells involved in the replacement of the necrotic zones seems to be crucial for wound healing.

  7. Investigations of the Climate System Response to Climate Engineering in a Hierarchy of Models

    NASA Astrophysics Data System (ADS)

    McCusker, Kelly E.

    Global warming due to anthropogenic emissions of greenhouse gases is causing negative impacts on diverse ecological and human systems around the globe, and these impacts are projected to worsen as climate continues to warm. In the absence of meaningful greenhouse gas emissions reductions, new strategies have been proposed to engineer the climate, with the aim of preventing further warming and avoiding associated climate impacts. We investigate one such strategy here, falling under the umbrella of `solar radiation management', in which sulfate aerosols are injected into the stratosphere. We use a global climate model with a coupled mixed-layer depth ocean and with a fully-coupled ocean general circulation model to simulate the stabilization of climate by balancing increasing carbon dioxide with increasing stratospheric sulfate concentrations. We evaluate whether or not severe climate impacts, such as melting Arctic sea ice, tropical crop failure, or destabilization of the West Antarctic ice sheet, could be avoided. We find that while tropical climate emergencies might be avoided by use of stratospheric aerosol injections, avoiding polar emergencies cannot be guaranteed due to large residual climate changes in those regions, which are in part due to residual atmospheric circulation anomalies. We also find that the inclusion of a fully-coupled ocean is important for determining the regional climate response because of its dynamical feedbacks. The efficacy of stratospheric sulfate aerosol injections, and solar radiation management more generally, depends on its ability to be maintained indefinitely, without interruption from a variety of possible sources, such as technological failure, a breakdown in global cooperation, lack of funding, or negative unintended consequences. We next consider the scenario in which stratospheric sulfate injections are abruptly terminated after a multi- decadal period of implementation while greenhouse gas emissions have continued unabated

  8. Ecological factors responsible for the geographic distribution of Rhabdias joaquinensis: where do lungworms infect anurans in nature?

    PubMed

    Langford, Gabriel J; Janovy, John

    2016-03-01

    The lungworm Rhabdias joaquinensis (Nematoda: Rhabdiasidae) is a common parasite of anurans in eastern Nebraska, yet absent from the same hosts in western Nebraska. This study investigated the ecology of the lungworm's free-living stages that reside in host feces and surrounding soils to establish the worm's free-living niche in eastern Nebraska. Using a comparative method, this study also investigated the absence of lungworms in western Nebraska's Sandhills. Soil composition, moisture, and temperature were experimentally varied in the laboratory to assess their effects on juvenile development and survival. Field mesocosm and host defecation experiments were used to determine where in nature lungworms survive and eventually infect frogs and toads and to discover if vegetation facilitates lungworm transmission to hosts. The results found loam soils were amenable to lungworm development, whereas soils with high clay or sand content produced few infective lungworms. Soil moisture <50 % did not support lungworm development. Infective juveniles successfully developed between 5 and 35 °C, albeit at different rates, whereas only a limited number of non-infective worms developed at 40 °C. Field studies found that shoreline environments supported lungworm development, and the majority of lungworm infections appear to occur within a zone of infection adjacent to shorelines in eastern Nebraska. The prevalence in vegetation mesocosms was 100 %, and a significantly higher mean abundance was found in toads from containers with vegetation than without. Overall, these experiments suggest that the spatial distribution of R. joaquinensis in Nebraska is constrained by the worm's ability to survive and reproduce in a soil matrix.

  9. Plasmid-Encoded Tetracycline Efflux Pump Protein Alters Bacterial Stress Responses and Ecological Fitness of Acinetobacter oleivorans

    PubMed Central

    Hong, Hyerim; Jung, Jaejoon; Park, Woojun

    2014-01-01

    Acquisition of the extracellular tetracycline (TC) resistance plasmid pAST2 affected host gene expression and phenotype in the oil-degrading soil bacterium, Acinetobacter oleivorans DR1. Whole-transcriptome profiling of DR1 cells harboring pAST2 revealed that all the plasmid genes were highly expressed under TC conditions, and the expression levels of many host chromosomal genes were modulated by the presence of pAST2. The host energy burden imposed by replication of pAST2 led to (i) lowered ATP concentrations, (ii) downregulated expression of many genes involved in cellular growth, and (iii) reduced growth rate. Interestingly, some phenotypes were restored by deleting the plasmid-encoded efflux pump gene tetH, suggesting that the membrane integrity changes resulting from the incorporation of efflux pump proteins also resulted in altered host response under the tested conditions. Alteration of membrane integrity by tetH deletion was shown by measuring permeability of fluorescent probe and membrane hydrophobicity. The presence of the plasmid conferred peroxide and superoxide resistance to cells, but only peroxide resistance was diminished by tetH gene deletion, suggesting that the plasmid-encoded membrane-bound efflux pump protein provided peroxide resistance. The downregulation of fimbriae-related genes presumably led to reduced swimming motility, but this phenotype was recovered by tetH gene deletion. Our data suggest that not only the plasmid replication burden, but also its encoded efflux pump protein altered host chromosomal gene expression and phenotype, which also alters the ecological fitness of the host in the environment. PMID:25229538

  10. Use of exposure-response bioassays on arabica punctulata for the determination of ecological risk. (Reannouncement with new availability information). Professional paper

    SciTech Connect

    Mueller, C.; Rogers, B.; Comeleo, P.; Jayaraman, S.; Munns, W.

    1992-11-01

    Two sea urchin exposure-response bioassays were conducted to develop a marine ecological risk assessment (ERA) model and to determine the effects of hazardous waste disposal at the Naval Construction Battalion Center (NCBC), Davisville,RI on the adjacent Allen Harbor and Narragansett Bay. Arbacia gametes and embryos were exposed for 20 min and 48 hr to serial dilutions of landfill-associated sediment extract and seep water samples to evaluate the effects of this disposal site on marine organisms. Successful fertilizations, normal and abnormal embryonic development, and 48 hr mortality were examined. Positive exposure-related responses were observed for both seep samples and sediment extracts. These models will be used to define current ecological risks to organisms representative of those in Allen Harbor.... Marine chemistry, Bentic flux.

  11. 28 CFR 57.2 - Responsibility for the conduct of investigations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Responsibility for the conduct of investigations. 57.2 Section 57.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) INVESTIGATION OF DISCRIMINATION IN THE SUPPLY OF PETROLEUM TO THE ARMED FORCES § 57.2 Responsibility for the conduct...

  12. 28 CFR 57.2 - Responsibility for the conduct of investigations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Responsibility for the conduct of investigations. 57.2 Section 57.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) INVESTIGATION OF DISCRIMINATION IN THE SUPPLY OF PETROLEUM TO THE ARMED FORCES § 57.2 Responsibility for the conduct...

  13. 28 CFR 57.2 - Responsibility for the conduct of investigations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Responsibility for the conduct of investigations. 57.2 Section 57.2 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) INVESTIGATION OF DISCRIMINATION IN THE SUPPLY OF PETROLEUM TO THE ARMED FORCES § 57.2 Responsibility for the conduct...

  14. Investigating the Decision Heuristics of Candidate Teachers Who Are Different in Their Responsibility Controls

    ERIC Educational Resources Information Center

    Özen, Yener

    2016-01-01

    In this study, decision heuristics used by individuals with different responsibility controls were investigated. In the research, 370 final grade university students studying at Erzincan University Faculty of Education were included. In order to collect data, Internally Controlled Responsibility-Externally Controlled Responsibility Scale of Özen…

  15. Ecological coassociations influence species' responses to past climatic change: an example from a Sonoran Desert bark beetle.

    PubMed

    Garrick, Ryan C; Nason, John D; Fernández-Manjarrés, Juan F; Dyer, Rodney J

    2013-06-01

    Ecologically interacting species may have phylogeographical histories that are shaped both by features of their abiotic landscape and by biotic constraints imposed by their coassociation. The Baja California peninsula provides an excellent opportunity to examine the influence of abiotic vs. biotic factors on patterns of diversity in plant-insect species.This is because past climatic and geological changes impacted the genetic structure of plants quite differently to that of codistributed free-living animals (e.g. herpetofauna and small mammals). Thus, 'plant-like' patterns should be discernible in host-specific insect herbivores. Here, we investigate the population history of a monophagous bark beetle, Araptus attenuatus, and consider drivers of phylogeographical patterns in the light of previous work on its host plant, Euphorbia lomelii. Using a combination of phylogenetic, coalescent-simulation-based and exploratory analyses of mitochondrial DNA sequences and nuclear genotypic data, we found that the evolutionary history of A. attenuatus exhibits similarities to its host plant that are attributable to both biotic and abiotic processes. Southward range expansion and recent colonization of continental Sonora from the Baja peninsula appear to be unique to this taxon pair and probably reflect influences of the host plant. On the other hand, abiotic factors with landscape level influences on a diverse suite of codistributed arid-adapted taxa, such as Plio- and Pleistocene-aged marine incursions in the region, also left genetic signatures in beetle and host plant populations. Superimposed on these similarities, bark beetle-specific patterns and processes were also evident: our data revealed two secondarily sympatric,reproductively isolated genetic lineages, as well as a previously unrecognized mid peninsular warm desert refuge. Taken together, this work illustrates that the evolutionary history of species-specific insect herbivores may represent a mosaic of influences

  16. Investigating the impact of a smart growth community on the contexts of children's physical activity using Ecological Momentary Assessment.

    PubMed

    Dunton, Genevieve F; Intille, Stephen S; Wolch, Jennifer; Pentz, Mary Ann

    2012-01-01

    This quasi-experimental research used Ecological Momentary Assessment with electronic surveys delivered through mobile phones to determine whether children change the type of contexts (i.e., settings) where they engage in physical activity after a recent move to a smart growth (SG) community in the U.S. as compared to children living in conventional low-to-medium density U.S. suburban communities (controls). SG vs. control children engaged in a greater proportion of physical activity bouts with friends, a few blocks from home, and at locations to which they walked. Over six months, the proportion of physical activity bouts reported at home (indoors) and in high traffic locations decreased among SG but not control children. Six-month increases in daily moderate-to-vigorous physical activity did not significantly differ by group. Children might have altered the type of contexts where they engage in physical activity after moving to SG communities, yet more time may be necessary for these changes to impact overall physical activity.

  17. Biobehavioral Mechanisms of Topiramate’s Effects on Alcohol Use: An Investigation Pairing Laboratory and Ecological Momentary Assessments

    PubMed Central

    Miranda, Robert; MacKillop, James; Treloar, Hayley; Blanchard, Alexander; Tidey, Jennifer W.; Swift, Robert M.; Chun, Thomas; Rohsenow, Damaris J.; Monti, Peter M.

    2014-01-01

    Topiramate reduces drinking, but little is known about the mechanisms that precipitate this effect. This double-blind randomized placebo-controlled study assessed the putative mechanisms by which topiramate reduces alcohol use among 96 adult nontreatment-seeking heavy drinkers in a laboratory-based alcohol cue reactivity assessment and in the natural environment using ecological momentary assessment methods. Topiramate reduced the quantity of alcohol heavy drinkers consumed on drinking days and reduced craving while participants were drinking but did not affect craving outside of drinking episodes in either the laboratory or in the natural environment. Topiramate did not alter the stimulant or sedative effects of alcohol ingestion during the ascending limb of the blood alcohol curve. A direct test of putative mechanisms of action using multilevel structural equation mediation models showed that topiramate reduced drinking indirectly by blunting alcohol-induced craving. These findings provide the first real-time prospective evidence that topiramate reduces drinking by reducing alcohol’s priming effects on craving and highlight the importance of craving as an important treatment target of pharmacotherapy for alcoholism. PMID:25353306

  18. Chemical ecology of fungi.

    PubMed

    Spiteller, Peter

    2015-07-01

    Fungi are widespread in nature and have conquered nearly every ecological niche. Fungi occur not only in terrestrial but also in freshwater and marine environments. Moreover, fungi are known as a rich source of secondary metabolites. Despite these facts, the ecological role of many of these metabolites is still unknown and the chemical ecology of fungi has not been investigated systematically so far. This review intends to present examples of the various chemical interactions of fungi with other fungi, plants, bacteria and animals and to give an overview of the current knowledge of fungal chemical ecology.

  19. Educational Responses to Newly Arrived Students in Sweden: Understanding the Structure and Influence of Post-Migration Ecology

    ERIC Educational Resources Information Center

    Nilsson, Jenny; Bunar, Nihad

    2016-01-01

    Education systems around the world have experienced a rise in the number of newly arrived students. This article explores the manner in which the Swedish education system responds to the diverse needs of these students. Using the concept of post-migration ecology, the authors outline and critically discuss the legal, organisational, and…

  20. Fire rehabilitation decisions at landscape scales: utilizing state-and-transition models developed through disturbance response grouping of ecological sites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recognizing the utility of ecological sites and the associated state-and-transition model (STM) for decision support, the Bureau of Land Management in Nevada partnered with Nevada NRCS and the University of Nevada, Reno (UNR) in 2009 with the goal of creating a team that could (1) expedite developme...

  1. An eco-hydrological approach to predicting regional vegetation and groundwater response to ecological water convergence in dryland riparian ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To improve the management strategy of riparian restoration, better understanding of the dynamic of eco-hydrological system and its feedback between hydrological and ecological components are needed. The fully distributed eco-hydrological model coupled with a hydrology component was developed based o...

  2. Ecological Misconceptions.

    ERIC Educational Resources Information Center

    Munson, Bruce H.

    1994-01-01

    Presents a summary of the research literature on students' ecological conceptions and the implications of misconceptions. Topics include food webs, ecological adaptation, carrying capacity, ecosystem, and niche. (Contains 35 references.) (MKR)

  3. Investigations into the organism level effects of the copper-induced oxidative stress response of Lemna gibba

    SciTech Connect

    Wall, V.D.; Klaine, S.J.

    1995-12-31

    The use of biochemical endpoints to indicate exposure to environmental toxicants is becoming an accepted technique to determine chemical bio-availability. However, these biochemical endpoints, or biomarkers, have not fulfilled their potential as indicators of sublethal stress when used in this capacity. Difficulties associated with using biochemical endpoints to assess stress arise in differentiating an ``abnormal`` stress response from a physiologically acceptable one and identifying sublethal stress in a biologically and ecologically significant manner. This research examines organism level effects of the copper-induced oxidative-stress response in Lemna gibba. The growth of Lemna gibba was significantly inhibited by aqueous copper concentrations greater than 0.05 ppm during a 10 day exposure. Although effects were dose dependent, the results indicated a conspicuous decrease in growth rates and increase in malformation and chlorosis at 0.5 ppm copper and higher. There were significantly elevated levels of lipid peroxidation products (expressed as thiobarbituric acid reactive species (TBARS)) at 0.1 ppm copper and higher. A decrease in growth rates without an increase in TBARS suggested a diversion of energy towards defensive mechanisms, primarily, superoxide dismutase, peroxidase, catalase and glutathione. These parameters were investigated and analyzed with respect to the organism-level effects (growth rates) of Lemna gibba. The utility and relevance of these sub-cellular parameters as indicators of chemical induced stress at the organism level will be discussed.

  4. Report on the remedial investigation of Bear Creek Valley at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee. Volume 6: Appendix G -- Baseline ecological risk assessment report

    SciTech Connect

    1996-09-01

    This Remedial Investigation (RI) Report characterizes the nature and extent of contamination, evaluates the fate and transport of contaminants, and assesses risk to human health and the environment resulting from waste disposal and other US Department of Energy (DOE) operations in Bear Creek Valley (BCV). BCV, which is located within the DOE Oak Ridge Reservation (ORR) encompasses multiple waste units containing hazardous and radioactive wastes arising from operations at the adjacent Oak Ridge Y-12 Plant. The primary waste units discussed in this RI Report are the S-3 Site, Oil Landfarm (OLF), Boneyard/Burnyard (BYBY), Sanitary Landfill 1 (SL 1), and Bear Creek Burial Grounds (BCBG). These waste units, plus the contaminated media resulting from environmental transport of the wastes from these units, are the subject of this RI. This BCV RI Report represents the first major step in the decision-making process for the BCV watershed. The RI results, in concert with the follow-on FS will form the basis for the Proposed Plan and Record of Decision for all BCV sites. This comprehensive decision document process will meet the objectives of the watershed approach for BCV. Appendix G contains ecological risks for fish, benthic invertebrates, soil invertebrates, plants, small mammals, deer, and predator/scavengers (hawks and fox). This risk assessment identified significant ecological risks from chemicals in water, sediment, soil, and shallow ground water. Metals and PCBs are the primary contaminants of concern.

  5. Seeing the Wood for the Trees: Applying the dual-memory system model to investigate expert teachers' observational skills in natural ecological learning environments

    NASA Astrophysics Data System (ADS)

    Stolpe, Karin; Björklund, Lars

    2012-01-01

    This study aims to investigate two expert ecology teachers' ability to attend to essential details in a complex environment during a field excursion, as well as how they teach this ability to their students. In applying a cognitive dual-memory system model for learning, we also suggest a rationale for their behaviour. The model implies two separate memory systems: the implicit, non-conscious, non-declarative system and the explicit, conscious, declarative system. This model provided the starting point for the research design. However, it was revised from the empirical findings supported by new theoretical insights. The teachers were video and audio recorded during their excursion and interviewed in a stimulated recall setting afterwards. The data were qualitatively analysed using the dual-memory system model. The results show that the teachers used holistic pattern recognition in their own identification of natural objects. However, teachers' main strategy to teach this ability is to give the students explicit rules or specific characteristics. According to the dual-memory system model the holistic pattern recognition is processed in the implicit memory system as a non-conscious match with earlier experienced situations. We suggest that this implicit pattern matching serves as an explanation for teachers' ecological and teaching observational skills. Another function of the implicit memory system is its ability to control automatic behaviour and non-conscious decision-making. The teachers offer the students firsthand sensory experiences which provide a prerequisite for the formation of implicit memories that provides a foundation for expertise.

  6. Distribution and mobility of heavy elements in floodplain agricultural soils along the Ibar River (Southern Serbia and Northern Kosovo). Chemometric investigation of pollutant sources and ecological risk assessment.

    PubMed

    Barać, Nemanja; Škrivanj, Sandra; Bukumirić, Zoran; Živojinović, Dragana; Manojlović, Dragan; Barać, Milan; Petrović, Rada; Ćorac, Aleksandar

    2016-05-01

    This work investigates the influence of a high-magnitude flood event on heavy elements (HEs) pollution and mobility in the agricultural soils along Ibar River in Southern Serbia and Northern Kosovo. The study area was one of the most important Pb/Zn industrial regions in Europe. Soil samples (n = 50) collected before and after the floods in May 2014 were subjected to the sequential extraction procedure proposed by the Community Bureau of Reference (BCR). The results indicated that the floods significantly increased not only the pseudo total concentrations of HEs in the soil but also their mobile and potentially bioavailable amounts. Moreover, higher concentrations (both pseudo total and potentially bioavailable) were found in the agricultural soils closer to the industrial hotspots. Principal component analysis and hierarchical cluster analysis successfully grouped the analyzed elements according to their anthropogenic or natural origin. The floods significantly increased the potential ecological risk of HEs associated with Pb/Zn industrial activities in the study area. The potential ecological risk of Cd after the floods was highest and should be of special concern.

  7. Backyard Ecology.

    ERIC Educational Resources Information Center

    Elser, Monica; Musheno, Birgit; Saltz, Charlene

    2003-01-01

    Describes the Ecology Explorers, the community education component of Arizona State University's Central Arizona Phoenix Long-Term Ecological Research project, which offers teacher internship programs that link university researchers, K-12 teachers, and students in studying urban ecology. Explains that student neighborhoods are dynamic ecosystems…

  8. Conspecific brood parasitism in the tropics: an experimental investigation of host responses in common moorhens and American purple gallinules

    PubMed Central

    McRae, Susan B

    2011-01-01

    Species occupying a broad latitudinal range may show greater phenotypic plasticity in behavior than species with smaller ranges or more specific habitat requirements. This study investigates for the first time the occurrence of conspecific brood parasitism (CBP) in sympatric tropical populations of the common moorhen (Gallinula chloropus pauxilla Bangs) and the American purple gallinule (Porphyrula martinica L.). CBP occurred in at least 20% (N = 76) of common moorhen nests on the Rio Chagres in Panama. Half (N = 20) of the parasitic eggs were accepted, but 10 were destroyed or ejected from host nests. Introductions of experimental eggs into nests revealed hosts were more likely to accept parasitism later in the host's laying period and during incubation, consistent with expectation of an adaptive response. CBP was not detected in a small sympatric population of American purple gallinules. Members of this population did not eject experimental eggs, suggesting a lack of experience with costly CBP. Contrasting ecological factors help explain why these two species of rail (Family Rallidae) differ in regard to CBP. Purple gallinule territories were sparse, owing to the distribution of preferred habitat. Moorhens flocked outside of the breeding season. They nested more synchronously, at higher densities, and primarily in ephemeral floating vegetation. Further, moorhens suffered a rate of nest loss nearly double that of American purple gallinules, and this increased over the course of the breeding season. Moorhen clutches were larger on average, and more variable in size than those of purple gallinules. Reproductive effort and rate (seasonality) constitute important life history differences between these species that may constrain the evolution of reproductive tactics. Comparing these sympatric populations, and others differing in life-history traits and ecological constraints, highlights the role of risk management in the evolution of CBP. PMID:22393503

  9. Experimental Investigation of Hydrofoil Force Response in Regular Seas at Low Chord Froude Numbers.

    DTIC Science & Technology

    1981-02-01

    7 AD-AU9 506 DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CE--ETC F/6 13/10 EXPERIMENTAL INVESTIGATION OF HYDROFOIL FORCE R SPONSE IN...r12 DAVID W. TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER Botheisda, Maryland 20084 0EXPERIMENTAL INVESTIGATION OF HYDROFOIL FORCE RESPONSE IN...NOTES 19. KEY WORDS (Continue on reverse side If necessary aid Identify by block number) Hydrofoil Response Lift Low Froude Number Drag Regular Waves

  10. Investigation of Millennial Students' Responses to a Shelter-in-Place Experience

    ERIC Educational Resources Information Center

    Johnson, Thomas C.; Frick, Melodie H.

    2016-01-01

    This study investigated millennial students' responses to an armed gunman threat and shelter-in-place warnings that occurred on a university campus. Using descriptive statistics and quantitative analysis, several significant differences were found for students' responses for sheltering-in-place and engaging in protective behaviors. Baxter Magolda'…

  11. Experimental investigation of the electrocaloric response and simulation of solid-state ferroelectric cooler

    NASA Astrophysics Data System (ADS)

    Es'kov, A. V.; Belyavskiy, P. Yu; Anokhin, A. S.; Semenov, A. A.; Pakhomov, V.; Mylnikov, I. L.; Nikitin, A. A.; Krylov, V. A.

    2016-08-01

    The electrocaloric response in ferroelectrics was experimentally investigated in nonequilibrium thermal conditions. The electrocaloric response reached 6 mK per one cycle polarization-depolarization of the ferroelectric sample. Computer modeling based on experimental data demonstrated the cooling capacity of multilayered structure at 25 W/cm3.

  12. Investigation of Stimulus-Response Compatibility Using a Startling Acoustic Stimulus

    ERIC Educational Resources Information Center

    Maslovat, Dana; Carlsen, Anthony N.; Franks, Ian M.

    2012-01-01

    We investigated the processes underlying stimulus-response compatibility by using a lateralized auditory stimulus in a simple and choice reaction time (RT) paradigm. Participants were asked to make either a left or right key lift in response to either a control (80dB) or startling (124dB) stimulus presented to either the left ear, right ear, or…

  13. Investigating Adult Language Input and Young Children's Responses in Naturalistic Environments: An Observational Framework

    ERIC Educational Resources Information Center

    Marinac, Julie V.; Woodyatt, Gail C.; Ozanne, Anne E.

    2008-01-01

    This paper reports the design and trial of an original Observational Framework for quantitative investigation of young children's responses to adult language in their typical language learning environments. The Framework permits recording of both the response expectation of the adult utterances, and the degree of compliance in the child's…

  14. Predictive systems ecology.

    PubMed

    Evans, Matthew R; Bithell, Mike; Cornell, Stephen J; Dall, Sasha R X; Díaz, Sandra; Emmott, Stephen; Ernande, Bruno; Grimm, Volker; Hodgson, David J; Lewis, Simon L; Mace, Georgina M; Morecroft, Michael; Moustakas, Aristides; Murphy, Eugene; Newbold, Tim; Norris, K J; Petchey, Owen; Smith, Matthew; Travis, Justin M J; Benton, Tim G

    2013-11-22

    Human societies, and their well-being, depend to a significant extent on the state of the ecosystems that surround them. These ecosystems are changing rapidly usually in response to anthropogenic changes in the environment. To determine the likely impact of environmental change on ecosystems and the best ways to manage them, it would be desirable to be able to predict their future states. We present a proposal to develop the paradigm of predictive systems ecology, explicitly to understand and predict the properties and behaviour of ecological systems. We discuss the necessary and desirable features of predictive systems ecology models. There are places where predictive systems ecology is already being practised and we summarize a range of terrestrial and marine examples. Significant challenges remain but we suggest that ecology would benefit both as a scientific discipline and increase its impact in society if it were to embrace the need to become more predictive.

  15. A new approach of Integrated Health Responses (IHR(s)) modeling for ecological risk/health assessments of an urban stream.

    PubMed

    Kim, Ja-Hyun; Yeom, Dong-Hyuk; An, Kwang-Guk

    2014-08-01

    The objective of this study was to evaluate the ecological health of an urban stream using Integrated Health Responses (IHRs). Water chemistry analysis, habitat health, and ecotoxicity tests were conducted in the stream along with analyses of molecular/biochemical, physiological biomarkers, and population-level responses in indicator species. Chemical stresses, measured as nutrient levels, ionic content and organic matter concentrations were significantly greater (p<0.01) at the downstream than the reference site (RF). The habitat health was largely impacted in the downstream reaches and had a negative relation with the land-use pattern of % urban area. Comet assay, 7-ethoxyresorufin-O-deethylase (EROD), acetylcholinesterase (AChE), and vitellogenin (VTG) were evaluated for low-level biomarker responses on DNA/physiological conditions of target species. The multi-metric fish model (Mm-F) was used to test the community-level response in relation to chemical and physical habitat stresses. The impaired responses of separate biomarker and bioindicator at the downstream sites occurred at all organizations from molecular/biochemical level to community level. Using all biomarkers/bioindicators, the star-plot model of IHRs was developed and then the integrative health/risk assessments were conducted in the urban stream. The reduced values of IHRs occurred in the downstream sites and the impacts were attributed to effluents from wastewater treatment plants (WTPs) and industrial complex. Ecological health impairments, thus, were evident in the urban reach, and reflected the long-term community responses as well as short-term responses of molecular biomarkers. The degradation of the urban stream was mainly due to a combined effect of chemical pollution and physical habitat modifications.

  16. Kyasanur forest disease virus breaking the endemic barrier: An investigation into ecological effects on disease emergence and future outlook.

    PubMed

    Ajesh, K; Nagaraja, B K; Sreejith, K

    2017-02-20

    Kyasanur Forest disease (KFD) is found in a limited range of India, but is epidemiologically understudied. The seasonal patterns of KFD are well known; however, the significant concern is on the extent to which changes in epidemiology happen especially under the influence of ecological destructions and by the eventual effects of resulting climate change. Presently, a southward and northward spread of the Kyasanur Forest disease virus (KFDV) along the Western Ghats has been reported in the adjoining states of Kerala, Tamil Nadu, Goa and Maharashtra. In this review, we investigate the cascade of factors that might have facilitated the resurgence of KFDV among the endemic regions in higher frequency and its recent emergence in the area previously not reported. Utilizing published data, we additionally endeavour to exhibit a portion of the impediments of control systems and embody the powerful option strategies for developing KFDV control.

  17. [Ecological monitoring in agro-ecological systems].

    PubMed

    Baĭkov, B D

    1983-01-01

    The fundamental principles of the ecologic monitoring in the antropogenic ecosystems are dealt with. Analyzed are the structure and function of the agroecologic systems, and, on the basis of the particular aspects established a concept is developed of the ecologic control at autoecologic and biocoenologic level. An analysis is likewise made of the ecologic sequelae resulting from the chemical war launched by the American aggressors in Vietnam and the specific trends therefrom in the substantiation of the ecologic monitoring. Stated is the necessity of profound investigations to establish the bioaccumulation of dioxine, a poisonous agent which was contained in herbicides and defoliants used in the war, and which was distinguished by exclusively high toxicity, producing teratogenic and cancerogenic effects and possessing high resistance in the environment.

  18. Ecological responses to UV radiation: interactions between the biological effects of UV on plants and on associated organisms.

    PubMed

    Paul, Nigel D; Moore, Jason P; McPherson, Martin; Lambourne, Cathryn; Croft, Patricia; Heaton, Joanna C; Wargent, Jason J

    2012-08-01

    Solar ultraviolet (UV)-B radiation (280-315 nm) has a wide range of effects on terrestrial ecosystems, yet our understanding of how UV-B influences the complex interactions of plants with pest, pathogen and related microorganisms remains limited. Here, we report the results of a series of experiments in Lactuca sativa which aimed to characterize not only key plant responses to UV radiation in a field environment but also consequential effects for plant interactions with a sap-feeding insect, two model plant pathogens and phylloplane microorganism populations. Three spectrally modifying filters with contrasting UV transmissions were used to filter ambient sunlight, and when compared with our UV-inclusive filter, L. sativa plants grown in a zero UV-B environment showed significantly increased shoot fresh weight, reduced foliar pigment concentrations and suppressed population growth of green peach aphid (Myzus persicae). Plants grown under a filter which allowed partial transmission of UV-A radiation and negligible UV-B transmission showed increased density of leaf surface phylloplane microbes compared with the UV-inclusive treatment. Effects of UV treatment on the severity of two plant pathogens, Bremia lactucae and Botrytis cinerea, were complex as both the UV-inclusive and zero UV-B filters reduced the severity of pathogen persistence. These results are discussed with reference to known spectral responses of plants, insects and microorganisms, and contrasted with established fundamental responses of plants and other organisms to solar UV radiation, with particular emphasis on the need for future integration between different experimental approaches when investigating the effects of solar UV radiation.

  19. Phase 1 Data Summary Report for the Clinch River Remedial Investigation: Health Risk and Ecological Risk Screening Assessment

    SciTech Connect

    Cook, R.B.

    1992-01-01

    The Clinch River Remedial Investigation (CRRI) is designed to address The transport, fate, and distribution of waterborne contaminants from the U.S. Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and to assess potential risks to human health and the environment associated with these contaminants. The contaminants released since the early 1940s include a variety of radionuclides, metals, and organic compounds. Primary areas of investigation are Melton Hill Reservoir, the Clinch River from Melton Hill Dam to its confluence with the Tennessee River, Poplar Creek, and Watts Bar Reservoir. The receiving river-reservoir system encompasses 140 river miles in length and 44,000 acres in surface area and is used for municipal water supply, sport fishing, navigation, boating, swimming, tourism, and residential development. The contaminants identified in the Clinch River/Watts Bar Reservoir (CR/WBR) downstream of the ORR are those associated with the water, suspended particles, deposited sediments, aquatic organisms, and wildlife feeding on aquatic organisms. A phased remedial investigation of the CR/WBR system is underway to (1) define the nature and extent of the off-site contamination, (2) evaluate associated environmental and human health risks, and (3) preliminarily identify and evaluate potential remediation alternatives. The purpose of this report is to summarize the results of Phase 1 of the CRRI.

  20. Investigation of P300 response characteristics through human color vision-based visual stimulation.

    PubMed

    Wilaiprasitporn, Theerawit; Yagi, Tohru

    2014-01-01

    In this study, we propose visual stimulation based on the primary colors (red, green, and blue) in order to investigate the characteristics of the P300 response. Eleven healthy volunteers participated in our experiment, and their brain signals were recorded by electroencephalography (EEG). Using two basic measures referred to as `on-peak' and `off-peak' for comparison of the P300 response among the participants, we found that the P300 response varies depending on the color of the stimulus. The results of this investigation are expected to contribute to various existing and future EEG-based applications.

  1. Putting flow-ecology relationships into practice: A decision-support system to assess fish community response to water-management scenarios

    USGS Publications Warehouse

    Cartwright, Jennifer M.; Caldwell, Casey; Nebiker, Steven; Knight, Rodney

    2017-01-01

    This paper presents a conceptual framework to operationalize flow–ecology relationships into decision-support systems of practical use to water-resource managers, who are commonly tasked with balancing multiple competing socioeconomic and environmental priorities. We illustrate this framework with a case study, whereby fish community responses to various water-management scenarios were predicted in a partially regulated river system at a local watershed scale. This case study simulates management scenarios based on interactive effects of dam operation protocols, withdrawals for municipal water supply, effluent discharges from wastewater treatment, and inter-basin water transfers. Modeled streamflow was integrated with flow–ecology relationships relating hydrologic departure from reference conditions to fish species richness, stratified by trophic, reproductive, and habitat characteristics. Adding a hypothetical new water-withdrawal site was predicted to increase the frequency of low-flow conditions with adverse effects for several fish groups. Imposition of new reservoir release requirements was predicted to enhance flow and fish species richness immediately downstream of the reservoir, but these effects were dissipated further downstream. The framework presented here can be used to translate flow–ecology relationships into evidence-based management by developing decision-support systems for conservation of riverine biodiversity while optimizing water availability for human use.

  2. Between Scylla and Charybdis: renegotiating resolution of the ‘obstetric dilemma’ in response to ecological change

    PubMed Central

    Wells, Jonathan C. K.

    2015-01-01

    Hominin evolution saw the emergence of two traits—bipedality and encephalization—that are fundamentally linked because the fetal head must pass through the maternal pelvis at birth, a scenario termed the ‘obstetric dilemma’. While adaptive explanations for bipedality and large brains address adult phenotype, it is brain and pelvic growth that are subject to the obstetric dilemma. Many contemporary populations experience substantial maternal and perinatal morbidity/mortality from obstructed labour, yet there is increasing recognition that the obstetric dilemma is not fixed and is affected by ecological change. Ecological trends may affect growth of the pelvis and offspring brain to different extents, while the two traits also differ by a generation in the timing of their exposure. Two key questions arise: how can the fit between the maternal pelvis and the offspring brain be ‘renegotiated’ as the environment changes, and what nutritional signals regulate this process? I argue that the potential for maternal size to change across generations precludes birthweight being under strong genetic influence. Instead, fetal growth tracks maternal phenotype, which buffers short-term ecological perturbations. Nevertheless, rapid changes in nutritional supply between generations can generate antagonistic influences on maternal and offspring traits, increasing the risk of obstructed labour. PMID:25602071

  3. Linking Topographic, Hydrologic, Climatic, and Ecologic Processes in Semi-arid Forests: an investigation of aboveground growth dynamics

    NASA Astrophysics Data System (ADS)

    Adams, H. R.; Loomis, A. K.; Barnard, H. R.

    2013-12-01

    Topography and climate play an integral role in the spatial variability and annual dynamics of aboveground carbon sequestration. Topographic, climatic, and hydrologic dynamics of a catchment interact to drive vegetation spatial distribution, growth patterns, and physiological processes in the catchment. Despite previous knowledge concerning gradient-theory influences on vegetation spatial distribution, little is known about the specific influence of complex terrain coupled with hydrologic and topo-climatic variation on aboveground biomass, especially in semi-arid forests of the Rocky Mountains. Climate change predictions for the semi-arid west, however, include increased temperatures, more frequent and extreme drought events, and decreases in snow pack all of which put forests at risk of altered species ranges and physiological processes, and susceptibility to disturbance events. In this study, we determine how species-specific tree growth patterns and water use efficiency respond to interannual variability in moisture availability (drought) through the use of dendrochronology techniques and carbon isotopes as a measure of water use efficiency with regard to topography and climate through data collection at 75 forest plots. Preliminary results suggest that tree growth and physiological processes respond directly to topographic and climatic parameters including aspect, elevation, and drought events (p < .05) and species vary in their response to these parameters (p < .05). Carbon isotope analyses indicate no significant difference appears in the water use efficiency of ponderosa pine between a drought year and a non-drought year while lodgepole pine water use efficiency increases significantly in a drought year. Both species, however, experience decreases in growth in drought years (p < .05) and, while aspect is a significant predictor of lodgepole pine tree growth in a wet year (p < .05), it becomes insignificant in a dry year. Varying responses from different

  4. Large-scale dam removal in the northeast United States: documenting ecological responses to the Penobscot River Restoration Project

    NASA Astrophysics Data System (ADS)

    Collins, M. J.; Aponte Clarke, G.; Baeder, C.; McCaw, D.; Royte, J.; Saunders, R.; Sheehan, T.

    2012-12-01

    The Penobscot River Restoration Project aims to improve aquatic connectivity in New England's second largest watershed ( 22,000 km2) by removing the two lowermost, mainstem dams and bypassing a third dam on a principal tributary upstream. Project objectives include: restoring unobstructed access to the entire historic riverine range for five lower river diadromous species including Atlantic and shortnose sturgeon; significantly improving access to upstream habitat for six upper river diadromous species including Atlantic salmon; reconnecting trophic linkages between headwater areas and the Gulf of Maine; restoring fluvial processes to the former impoundments; improving recreational and Penobscot Nation cultural opportunities; and maintaining basin-wide hydropower output. The project is expected to have landscape-scale benefits and the need for a significant investment in long-term monitoring and evaluation to formally quantify ecosystem response has been recognized. A diverse group of federal, state, tribal, NGO, and academic partners has developed a long-term monitoring and evaluation program composed of nine studies that began in 2009. Including American Recovery and Reinvestment Act (ARRA) funding that leveraged partner contributions, we have invested nearly $2M to date in pre- and post-removal investigations that evaluate geomorphology/bed sediment, water quality, wetlands, and fisheries. Given the number of affected diadromous species and the diversity of their life histories, we have initiated six distinct, but related, fisheries investigations to document these expected changes: Atlantic salmon upstream and downstream passage efficiency using passive integrated transponder (PIT) and acoustic telemetry; fish community structure via an index of biotic integrity (IBI); total diadromous fish biomass through hydroacoustics; shortnose sturgeon spawning and habitat use via active and passive acoustic telemetry; and freshwater-marine food web interactions by

  5. 36 CFR 219.20 - Ecological sustainability.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Ecological sustainability... Sustainability § 219.20 Ecological sustainability. To achieve ecological sustainability, the responsible official... diversity and species diversity are components of ecological sustainability. The planning process...

  6. 36 CFR 219.20 - Ecological sustainability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Ecological sustainability... Sustainability § 219.20 Ecological sustainability. To achieve ecological sustainability, the responsible official... diversity and species diversity are components of ecological sustainability. The planning process...

  7. Specificity in ecological interactions: attack from the same lepidopteran herbivore results in species-specific transcriptional responses in two solanaceous host plants.

    PubMed

    Schmidt, Dominik D; Voelckel, Claudia; Hartl, Markus; Schmidt, Silvia; Baldwin, Ian T

    2005-07-01

    Model systems have proven enormously useful in elucidating the biochemical function of plant genes. However their ecological function, having been sculpted by evolutionary forces specific to a species, may be less conserved across taxa. Responses to wounding and herbivore attack differ among plant families and are known to be mediated by oxylipin, ethylene, and systemin-signaling networks. We analyzed transcriptional responses of two native Solanaceous species to the attack of an herbivore whose elicitors are known not to be influenced by diet. With The Institute for Genomic Research 10k-cDNA potato (Solanum tuberosum) microarray, we compared the transcriptional responses of Nicotiana attenuata with those of black nightshade (Solanum nigrum) when both were attacked by the Solanaceous generalist herbivore, Manduca sexta. Based on an NADH dehydrogenase subunit F phylogeny, S. nigrum is more closely related to potato than N. attenuata but responded significantly less to M. sexta attack. Apart from transcriptional differences anticipated from their differences in secondary metabolism, both species showed distinct transcriptional patterns (with only 10% overlap in significantly regulated genes), which point to fundamental differences in the signaling cascades and downstream genes mediating herbivore resistance. The lackluster transcriptional response of S. nigrum could not be attributed to its inability to respond to elicitation, because methyl jasmonate elicitation of S. nigrum resulted in a strong transcriptional response. Given that attack from the same herbivore elicits profoundly different responses in two Solanaceaous taxa, we conclude that blueprints for commonly regulated responses to plant-herbivore interactions appear unlikely.

  8. Phase 1 data summary report for the Clinch River Remedial Investigation: Health risk and ecological risk screening assessment

    SciTech Connect

    Cook, R.B.; Adams, S.M.; Beauchamp, J.J.; Bevelhimer, M.S.; Blaylock, B.G.; Brandt, C.C.; Ford, C.J.; Frank, M.L.; Gentry, M.J.; Holladay, S.K.; Hook, L.A.; Levine, D.A.; Longman, R.C.; McGinn, C.W.; Skiles, J.L.; Suter, G.W.; Williams, L.F.

    1992-12-01

    The Clinch River Remedial Investigation (CRRI) is designed to address the transport, fate, and distribution of waterborne contaminants released from the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and to assess potential risks to human health and the environment associated with these contaminants. The contaminants released since the early 1940s include a variety of radionuclides, metals, and organic compounds. The purpose of this report is to summarize the results of Phase 1 of the CRRI. Phase 1 was designed to (1) obtain high-quality data to confirm existing historical data for contaminant levels in fish, sediment, and water from the CR/WBR; (2) determine the in the range of contaminant concentrations present river-reservoir system; (3) identify specific contaminants of concern; and (4) establish the reference (background) concentrations for those contaminants.

  9. Elevational clines in the temperature dependence of insect performance and implications for ecological responses to climate change

    PubMed Central

    Buckley, Lauren B.; Nufio, César R.

    2014-01-01

    To what extent is insect hopping and feeding performance, which constrains the ability to obtain and assimilate resources, thermally adapted along an elevation gradient? Does temperature dependence vary between populations and species and can differences account for individualistic responses to past climate change? We investigate these questions for three species of grasshoppers along a Rocky Mountain elevation gradient. All species and populations exhibit warm adaptation for consumption and digestion, with only modest inter- and intra-specific differences. Species differ substantially in the temperature of peak hopping performance. Low-elevation populations of the warm-adapted species exhibit the highest performance at high temperatures and the lowest performance at low temperatures. Developmental plasticity influences the temperature dependence of performance; grasshoppers reared at higher temperatures perform better at higher temperatures and possess broader thermal tolerance. We fitted thermal performance curves to examine whether performance shifts can account for changes in abundance between initial surveys in 1958–1960 and recent surveys since 2006. All species and populations are able to achieve greater feeding rates now. Estimated shifts in hopping performance vary between species and along the elevation gradient. The cool-adapted species has experienced declines in hopping performance, particularly at the lower elevation sites, while the warm-adapted species has experienced increases in performance concentrated at higher elevations. These estimated performance shifts broadly concur with observed abundance shifts. Performance metrics may have a greater potential to elucidate differential responses to climate change between populations and species than coarser and oft-used proxies, such as thermal tolerance. Assessing performance directly when temperature dependence varies between processes such as the acquisition and assimilation of energy may be

  10. Anuran larval developmental plasticity and survival in response to variable salinity of ecologically relevant timing and magnitude.

    PubMed

    Kearney, Brian D; Pell, Rebecca J; Byrne, Phillip G; Reina, Richard D

    2014-12-01

    Salinity in affected freshwater ecosystems fluctuates with seasonal rainfall, tidal flux, rates of evaporation, chemical runoff and the influence of secondary salinization. Environmental stressors such as salinity can have lasting effects on anuran development, yet little is known about the effects of fluctuating salinity on tadpole ontogeny or the effects of differing magnitudes of salinity exposure, as would occur in natural wetland systems. We examined how salinity fluctuations affected survival, growth and development of Litoria ewingii by exposing tadpoles to a range of salinity concentrations (5.6-10.85 ppt) at three different stages of development (hind limb-bud formation; toe differentiation and forearm development). We also investigated the plasticity of tadpole growth rates in response to non-lethal, transient salinity influxes, specifically examining the capacity for compensatory growth and its relationship to the timing, magnitude or frequency of salinity exposure. Our results show that later-stage tadpoles are more tolerant to elevated salinity than those exposed at a younger age, and that exposure to high salinity later in life suppresses the potential for compensatory growth. Tadpoles exposed to transient low salinity lost less mass during metamorphosis than animals in constant salinity treatments, indicating a possible alternate to compensatory growth. Exposure to near-lethal salinities early in development did not alter tadpole responses to subsequent salinity stress. Our results provide some of the first evidence that both the timing and magnitude of transient environmental stressors can have an effect on anuran development and developmental trade-offs in a stressful environment.

  11. A Field Study in Benin to Investigate the Role of Mosquitoes and Other Flying Insects in the Ecology of Mycobacterium ulcerans

    PubMed Central

    Zogo, Barnabas; Djenontin, Armel; Carolan, Kevin; Babonneau, Jeremy; Guegan, Jean-François; Eyangoh, Sara; Marion, Estelle

    2015-01-01

    Background Buruli ulcer, the third mycobacterial disease after tuberculosis and leprosy, is caused by the environmental mycobacterium M. ulcerans. There is at present no clear understanding of the exact mode(s) of transmission of M. ulcerans. Populations affected by Buruli ulcer are those living close to humid and swampy zones. The disease is associated with the creation or the extension of swampy areas, such as construction of dams or lakes for the development of agriculture. Currently, it is supposed that insects (water bugs and mosquitoes) are host and vector of M. ulcerans. The role of water bugs was clearly demonstrated by several experimental and environmental studies. However, no definitive conclusion can yet be drawn concerning the precise importance of this route of transmission. Concerning the mosquitoes, DNA was detected only in mosquitoes collected in Australia, and their role as host/vector was never studied by experimental approaches. Surprisingly, no specific study was conducted in Africa. In this context, the objective of this study was to investigate the role of mosquitoes (larvae and adults) and other flying insects in ecology of M. ulcerans. This study was conducted in a highly endemic area of Benin. Methodology/Principal Findings Mosquitoes (adults and larvae) were collected over one year, in Buruli ulcer endemic in Benin. In parallel, to monitor the presence of M. ulcerans in environment, aquatic insects were sampled. QPCR was used to detected M. ulcerans DNA. DNA of M. ulcerans was detected in around 8.7% of aquatic insects but never in mosquitoes (larvae or adults) or in other flying insects. Conclusion/Significance This study suggested that the mosquitoes don't play a pivotal role in the ecology and transmission of M. ulcerans in the studied endemic areas. However, the role of mosquitoes cannot be excluded and, we can reasonably suppose that several routes of transmission of M. ulcerans are possible through the world. PMID:26196901

  12. Epidemiologic Responses to Anthrax Outbreaks: A Review of Field Investigations, 1950–2001

    PubMed Central

    Bales, Michael E.; Brachman, Philip S.; Kaufmann, Arnold F.; Klatsky, Peter C.; Ashford, David A.

    2002-01-01

    We used unpublished reports, published manuscripts, and communication with investigators to identify and summarize 49 anthrax-related epidemiologic field investigations conducted by the Centers for Disease Control and Prevention from 1950 to August 2001. Of 41 investigations in which Bacillus anthracis caused human or animal disease, 24 were in agricultural settings, 11 in textile mills, and 6 in other settings. Among the other investigations, two focused on building decontamination, one was a response to bioterrorism threats, and five involved other causes. Knowledge gained in these investigations helped guide the public health response to the October 2001 intentional release of B. anthracis, especially by addressing the management of anthrax threats, prevention of occupational anthrax, use of antibiotic prophylaxis in exposed persons, use of vaccination, spread of B. anthracis spores in aerosols, clinical diagnostic and laboratory confirmation methods, techniques for environmental sampling of exposed surfaces, and methods for decontaminating buildings. PMID:12396934

  13. Epizootiologic and ecologic investigations of European brown hares (Lepus europaeus) in selected populations from Schleswig-Holstein, Germany.

    PubMed

    Frölich, Kai; Wisser, Jutta; Schmüser, Heiko; Fehlberg, Ulrich; Neubauer, Heinrich; Grunow, Roland; Nikolaou, Konstantin; Priemer, Jürgen; Thiede, Svenja; Streich, Wolf Jürgen; Speck, Stephanie

    2003-10-01

    From 1997-99 European brown hare (Lepus europaeus) population densities were estimated by spotlight surveys within different areas in Schleswig-Holstein, Germany. These areas showed a wide variation in local hare population densities. In addition, red fox (Vulpes vulpes) densities were estimated in 1997 by surveys of fox dens and litters. Sera of 321 hares (shot between 1998-2000) from four study areas were examined for antibodies against European brown hare syndrome virus (EBHSV) by enzyme linked immunosorbent assay (ELISA), Yersinia spp. (n = 299) and Francisella tularensis (n = 299) by western blotting, Brucella spp. by Rose Bengal test, and Toxoplasma gondii by Sabin-Feldman test (n = 318). Tissue samples comprising lung, liver, spleen, kidney, heart, and adrenal glands were collected for histopathology. Liver (n = 201) and spleen (n = 201) samples were processed for the detection of T. gondii-antigen in tissue sections and 321 liver and spleen samples were investigated for EBHSV-antigen by ELISA. Furthermore, 116 hares were examined macro- and microscopically for lungworms. Significant negative correlations between hare and fox densities were found in spring and autumn 1997. Antibodies against EBHSV were detected in 92 of 321 (29%), against Yersinia spp. in 163 of 299 (55%), and against T. gondii in 147 of 318 (46%) hares. We evaluated the potential influence of origin and hunting season on exposure rates of hares using logistic regression analysis. A strong association between hare densities and exposure rates was observed for various agents. One hundred and eight of 201 (57%) hares were positive for T. gondii-antigen. All sera were negative for antibodies against Brucella spp. and F. tularensis and all lung samples were negative for lungworms. In conclusion, variation in red fox densities may have an impact on the hare populations examined and the infectious diseases we studied seem to play a subordinate role in the dynamics of European brown hare

  14. An imaging-based tumour growth and treatment response model: Investigating the effect of tumour oxygenation on radiation therapy response

    PubMed Central

    Jeraj, Robert

    2010-01-01

    A multiscale tumour simulation model employing cell-line-specific biological parameters and functional information derived from pre-therapy PET/CT imaging data was developed to investigate effects of different oxygenation levels on the response to radiation therapy. For each tumour voxel, stochastic simulations were performed to model cellular growth and therapeutic response. Model parameters were fitted to published preclinical experiments of head and neck squamous cell carcinoma (HNSCC). Using the obtained parameters, the model was applied to a human HNSCC case to investigate effects of different uniform and non-uniform oxygenation levels and results were compared for treatment efficacy. Simulations of the preclinical studies showed excellent agreement with published data and underlined the model’s ability to quantitatively reproduce tumour behaviour within experimental uncertainties. When using a simplified transformation to derive non-uniform oxygenation levels from molecular imaging data, simulations of the clinical case showed heterogeneous tumour response and variability in radioresistance with decreasing oxygen levels. Once clinically validated, this model could be used to transform patient-specific data into voxel-based biological objectives for treatment planning and to investigate biologically optimized dose prescriptions. PMID:18677042

  15. ``Yo soy indígena'': identifying and using traditional ecological knowledge (TEK) to make the teaching of science culturally responsive for Maya girls

    NASA Astrophysics Data System (ADS)

    Hamlin, Maria L.

    2013-12-01

    This study examines how traditional ecological knowledge—TEK—can be identified and utilized to create culturally responsive science learning opportunities for Maya girls from a community in the Guatemalan highlands. Maya girls are situated in a complex socio-historical and political context rooted in racism and sexism. This study contextualizes the current situation of Maya women and girls in Guatemala and emphasizes the important need for educators to create science-learning opportunities that are culturally congruent. The author posits that when considering how to make the teaching and learning of science culturally responsive for Maya girls, educators must begin with the scientific knowledge inherent within Maya communities. Indigenous communities have a wealth of TEK that can be used to contextualize science curricula that can be purposely designed to meet the nuanced cultural needs of traditional Maya girls within and outside Guatemala.

  16. An ecological approach to promoting population mental health and well-being--a response to the challenge of climate change.

    PubMed

    Nurse, Jo; Basher, Damian; Bone, Angie; Bird, William

    2010-01-01

    Climate change can be viewed as human-induced change to climate and depletion of natural systems. It potentially the biggest global health threat of the 21st century. It is predicted to have wide-ranging impacts upon human mental health and well-being, through changes and challenges to people's environment, socioeconomic structures and physical security. Even the most conservative estimates of the health impacts are extremely alarming. Increasingly, the causes of poor human health and environmental damage are related. This implies that there are common solutions. For example, there are co-benefits to human health and biodiversity from mitigating and adapting to climate change (e.g. promoting active transport and reducing car use reduces CO2 emissions, benefits our environment and reduces morbidity and mortality associated with a sedentary lifestyle). This article outlines how climate change impacts upon mental health and well-being. It introduces ecological concepts, applies these to public health and outlines their implications in transforming the way that we prioritize and deliver public health in order to promote both environmental and human health. Evidence, from psychology and neuroscience, suggests that the perception of being disconnected from our inner selves, from each other and from our environment has contributed to poor mental and physical health. We argue that we must transform the way we understand mental health and well-being and integrate it into action against climate change. We describe a Public Health Framework for Developing Well-Being, based on the principles of ecological public health.

  17. Investigating the effectiveness of response strategies for vulnerabilities to corruption in the chinese public construction sector.

    PubMed

    Shan, Ming; Chan, Albert P C; Le, Yun; Hu, Yi

    2015-06-01

    Response strategy is a key for preventing widespread corruption vulnerabilities in the public construction sector. Although several studies have been devoted to this area, the effectiveness of response strategies has seldom been evaluated in China. This study aims to fill this gap by investigating the effectiveness of response strategies for corruption vulnerabilities through a survey in the Chinese public construction sector. Survey data obtained from selected experts involved in the Chinese public construction sector were analyzed by factor analysis and partial least squares-structural equation modeling. Analysis results showed that four response strategies of leadership, rules and regulations, training, and sanctions, only achieved an acceptable level in preventing corruption vulnerabilities in the Chinese public construction sector. This study contributes to knowledge by improving the understanding of the effectiveness of response strategies for corruption vulnerabilities in the public construction sector of developing countries.

  18. Is outcome responsibility at work emotionally exhausting? Investigating employee proactivity as a moderator.

    PubMed

    Schmitt, Antje; Den Hartog, Deanne N; Belschak, Frank D

    2015-10-01

    This study investigates the relationship between outcome responsibility and employees' well-being in terms of emotional exhaustion. Outcome responsibility is a job demand implying that employees' decisions at work have high material and/or nonmaterial consequences. Previous research indicates that outcome responsibility can have both positive and negative effects on employee well-being. Based on the person-job fit approach we hypothesize that whether or not outcome responsibility is positively or negatively related to emotional exhaustion depends on whether employees' behavioral style fits with this job demand. We investigate the role of proactive behavior as a personal resource that fits with high responsibility. We test our hypothesis in a multisource study among 138 employee-colleague dyads. Results of hierarchical moderated regression analysis reveal that peer-rated proactive behavior moderates the relationship between outcome responsibility and emotional exhaustion, such that the relationship is negative for employees showing high and nonsignificant for employees showing low proactivity. This finding holds also when controlling for trait positive and negative affect. The current study contributes to previous research on job design, proactivity, and occupational well-being and offers practical implications in terms of selection and training of employees for jobs high in outcome responsibility.

  19. Integration of aquatic fate and ecological responses to linear alkyl benzene sulfonate (LAS) in model stream ecosystems.

    PubMed

    Belanger, S E; Bowling, J W; Lee, D M; LeBlanc, E M; Kerr, K M; McAvoy, D C; Christman, S C; Davidson, D H

    2002-06-01

    An integrated model stream ecosystem fate and effect study of dodecyl linear alkylbenzene sulfonate (C(12)LAS) was performed in the summer and fall of 1996. The study addressed responses of periphytic microbes, immature benthic fauna including abundance, drift, and emergence of adult insects in a 56-day exposure. Exposures ranged from 126 to 2978 microg/L and were continuously presented in a single-pass, flow-through test system. Microbial heterotrophs acclimated to C(12)LAS exposure quickly (14 days) and biodegraded C(12)LAS at all concentrations. Blue-green algae responded by increasing in abundance with increasing C(12)LAS concentration. Invertebrates responded by increased drift and reduced benthic abundances at concentrations exceeding 293 microg/L. Emergence at 927 microg/L also declined relative to the control. Adverse responses for mayflies and chironomids were indicated using univariate statistical techniques. Multivariate techniques indicated these taxa plus mollusks, aquatic worms, caddisflies, and stoneflies were impaired at some concentrations. Bioavailability of C(12)LAS was investigated in streams as a function of the total suspended solid load in the water column driven by local weather and watershed patterns. A continuous bioavailability model indicated exposure was reduced by an average of 8.5+/-8.9%. A model ecosystem no-observed-effect concentration (NOEC) was concluded to be 293 microg/L based on measured water column exposure and adjusted to 268 microg/L by the bioavailability model. A literature review of 13 available model ecosystem studies was conducted and NOEC conclusions were adjusted by a structure-activity relationship to a dodecyl chain length (sulfophenyl position and distribution being ignored due to lack of information in the reviewed studies). Lentic studies (n=7) were found to have higher NOECs than lotic studies (n=6) and were more variable. Mean NOECs+/-SD for all studies, lentic studies only, and lotic studies only were 3320

  20. Spatially Explicit Landscape-Level Ecological Risks Induced by Land Use and Land Cover Change in a National Ecologically Representative Region in China.

    PubMed

    Gong, Jian; Yang, Jianxin; Tang, Wenwu

    2015-11-09

    Land use and land cover change is driven by multiple influential factors from environmental and social dimensions in a land system. Land use practices of human decision-makers modify the landscape of the land system, possibly leading to landscape fragmentation, biodiversity loss, or environmental pollution-severe environmental or ecological impacts. While landscape-level ecological risk assessment supports the evaluation of these impacts, investigations on how these ecological risks induced by land use practices change over space and time in response to alternative policy intervention remain inadequate. In this article, we conducted spatially explicit landscape ecological risk analysis in Ezhou City, China. Our study area is a national ecologically representative region experiencing drastic land use and land cover change, and is regulated by multiple policies represented by farmland protection, ecological conservation, and urban development. We employed landscape metrics to consider the influence of potential landscape-level disturbance for the evaluation of landscape ecological risks. Using spatiotemporal simulation, we designed scenarios to examine spatiotemporal patterns in landscape ecological risks in response to policy intervention. Our study demonstrated that spatially explicit landscape ecological risk analysis combined with simulation-driven scenario analysis is of particular importance for guiding the sustainable development of ecologically vulnerable land systems.

  1. Spatially Explicit Landscape-Level Ecological Risks Induced by Land Use and Land Cover Change in a National Ecologically Representative Region in China

    PubMed Central

    Gong, Jian; Yang, Jianxin; Tang, Wenwu

    2015-01-01

    Land use and land cover change is driven by multiple influential factors from environmental and social dimensions in a land system. Land use practices of human decision-makers modify the landscape of the land system, possibly leading to landscape fragmentation, biodiversity loss, or environmental pollution—severe environmental or ecological impacts. While landscape-level ecological risk assessment supports the evaluation of these impacts, investigations on how these ecological risks induced by land use practices change over space and time in response to alternative policy intervention remain inadequate. In this article, we conducted spatially explicit landscape ecological risk analysis in Ezhou City, China. Our study area is a national ecologically representative region experiencing drastic land use and land cover change, and is regulated by multiple policies represented by farmland protection, ecological conservation, and urban development. We employed landscape metrics to consider the influence of potential landscape-level disturbance for the evaluation of landscape ecological risks. Using spatiotemporal simulation, we designed scenarios to examine spatiotemporal patterns in landscape ecological risks in response to policy intervention. Our study demonstrated that spatially explicit landscape ecological risk analysis combined with simulation-driven scenario analysis is of particular importance for guiding the sustainable development of ecologically vulnerable land systems. PMID:26569270

  2. Thermal onset of cellular and endocrine stress responses correspond to ecological limits in brook trout, an iconic cold-water fish

    USGS Publications Warehouse

    Chadwick, Joseph G; Nislow, Kieth H; McCormick, Stephen

    2015-01-01

    Climate change is predicted to change the distribution and abundance of species, yet underlying physiological mechanisms are complex and methods for detecting populations at risk from rising temperature are poorly developed. There is increasing interest in using physiological mediators of the stress response as indicators of individual and population-level response to environmental stressors. Here, we use laboratory experiments to show that the temperature thresholds in brook trout (Salvelinus fontinalis) for increased gill heat shock protein-70 (20.7°C) and plasma glucose (21.2°C) are similar to their proposed thermal ecological limit of 21.0°C. Field assays demonstrated increased plasma glucose, cortisol and heat shock protein-70 concentrations at field sites where mean daily temperature exceeded 21.0°C. Furthermore, population densities of brook trout were lowest at field sites where temperatures were warm enough to induce a stress response, and a co-occurring species with a higher thermal tolerance showed no evidence of physiological stress at a warm site. The congruence of stress responses and proposed thermal limits supports the use of these thresholds in models of changes in trout distribution under climate change scenarios and suggests that the induction of the stress response by elevated temperature may play a key role in driving the distribution of species.

  3. Thermal onset of cellular and endocrine stress responses correspond to ecological limits in brook trout, an iconic cold-water fish

    PubMed Central

    Chadwick, Joseph G.; Nislow, Keith H.; McCormick, Stephen D.

    2015-01-01

    Climate change is predicted to change the distribution and abundance of species, yet underlying physiological mechanisms are complex and methods for detecting populations at risk from rising temperature are poorly developed. There is increasing interest in using physiological mediators of the stress response as indicators of individual and population-level response to environmental stressors. Here, we use laboratory experiments to show that the temperature thresholds in brook trout (Salvelinus fontinalis) for increased gill heat shock protein-70 (20.7°C) and plasma glucose (21.2°C) are similar to their proposed thermal ecological limit of 21.0°C. Field assays demonstrated increased plasma glucose, cortisol and heat shock protein-70 concentrations at field sites where mean daily temperature exceeded 21.0°C. Furthermore, population densities of brook trout were lowest at field sites where temperatures were warm enough to induce a stress response, and a co-occurring species with a higher thermal tolerance showed no evidence of physiological stress at a warm site. The congruence of stress responses and proposed thermal limits supports the use of these thresholds in models of changes in trout distribution under climate change scenarios and suggests that the induction of the stress response by elevated temperature may play a key role in driving the distribution of species. PMID:27293702

  4. Variation of Vegetation Ecological Water Consumption and Its Response to Vegetation Coverage Changes in the Rocky Desertification Areas in South China

    PubMed Central

    Zhou, Jinxing; Guo, Hongyan; Cui, Ming; Liu, Yuguo; Ning, Like; Tang, Fukai

    2016-01-01

    Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regional water stresses. This study explored the changes in the actual evapotranspiration (ETa) response to the vegetation coverage changes in the rocky desertification areas in South China based on the precipitation (P), potential evapotranspiration (ETp) and NDVI (the normalized difference vegetation index) datasets. The revised Bagrov model was used to simulate the actual evapotranspiration changes with the supposed increasing NDVI. The results indicated that the average NDVI value was lower when the rocky desertification was more severe. The ETa, evapotranspiration efficiency (ETa/ETp) and potential humidity (P/ETp) generally increased with the increasing NDVI. The sensitivity of the ETa response to vegetation coverage changes varied due to different precipitation conditions and different rocky desertification severities. The ETa was more sensitive under drought conditions. When a drought occurred, the ETa exhibited an average increase of 40~60 mm with the NDVI increasing of 0.1 in the rocky desertification areas. Among the 5 different severity categories of rocky desertification, the ETa values’ responses to NDVI changes were less sensitive in the severe rocky desertification areas but more sensitive in the extremely and potential rocky desertification areas. For example, with the NDVI increasing of 0.025, 0.05, 0.075, and 0.1, the corresponding ETa changes increased by an average of 2.64 mm, 10.62 mm, 19.19 mm, and 27.58 mm, respectively, in severe rocky desertification areas but by 4.94 mm, 14.99 mm, 26.80, and 37.13 mm, respectively, in extremely severe rocky

  5. Variation of Vegetation Ecological Water Consumption and Its Response to Vegetation Coverage Changes in the Rocky Desertification Areas in South China.

    PubMed

    Wan, Long; Tong, Jing; Zhou, Jinxing; Guo, Hongyan; Cui, Ming; Liu, Yuguo; Ning, Like; Tang, Fukai

    2016-01-01

    Over the past several decades, rocky desertification has led to severe ecological problems in karst areas in South China. After a rocky desertification treatment project was completed, the vegetation coverage changed greatly and, consequently, increased the ecology water consumption (approximately equal to the actual evapotranspiration) of the regional vegetation. Thus, it intensified the regional water stresses. This study explored the changes in the actual evapotranspiration (ETa) response to the vegetation coverage changes in the rocky desertification areas in South China based on the precipitation (P), potential evapotranspiration (ETp) and NDVI (the normalized difference vegetation index) datasets. The revised Bagrov model was used to simulate the actual evapotranspiration changes with the supposed increasing NDVI. The results indicated that the average NDVI value was lower when the rocky desertification was more severe. The ETa, evapotranspiration efficiency (ETa/ETp) and potential humidity (P/ETp) generally increased with the increasing NDVI. The sensitivity of the ETa response to vegetation coverage changes varied due to different precipitation conditions and different rocky desertification severities. The ETa was more sensitive under drought conditions. When a drought occurred, the ETa exhibited an average increase of 40~60 mm with the NDVI increasing of 0.1 in the rocky desertification areas. Among the 5 different severity categories of rocky desertification, the ETa values' responses to NDVI changes were less sensitive in the severe rocky desertification areas but more sensitive in the extremely and potential rocky desertification areas. For example, with the NDVI increasing of 0.025, 0.05, 0.075, and 0.1, the corresponding ETa changes increased by an average of 2.64 mm, 10.62 mm, 19.19 mm, and 27.58 mm, respectively, in severe rocky desertification areas but by 4.94 mm, 14.99 mm, 26.80, and 37.13 mm, respectively, in extremely severe rocky

  6. Soil Ecology

    NASA Astrophysics Data System (ADS)

    Killham, Ken

    1994-04-01

    Soil Ecology is designed to meet the increasing challenge faced by today's environmental scientists, ecologists, agriculturalists, and biotechnologists for an integrated approach to soil ecology. It emphasizes the interrelations among plants, animals, and microbes, by first establishing the fundamental physical and chemical properties of the soil habitat and then functionally characterizing the major components of the soil biota and some of their most important interactions. The fundamental principles underpinning soil ecology are established and this then enables an integrated approach to explore and understand the processes of soil nutrient (carbon, nitrogen, and phosphorus) cycling and the ecology of extreme soil conditions such as soil-water stress. Two of the most topical aspects of applied soil ecology are then selected. First, the ecology of soil pollution is examined, focusing on acid deposition and radionuclide pollution. Second, manipulation of soil ecology through biotechnology is discussed, illustrating the use of pesticides and microbial inocula in soils and pointing toward the future by considering the impact of genetically modified inocula on soil ecology.

  7. Ecology of estuaries

    SciTech Connect

    Kennish, M.J.

    1986-01-01

    This book is a summary of information available on estuarine ecology, that reviews concepts and problems of estuaries and assesses the value of these coastal systems. It investigates such topics as water circulation and mixing, trace elements, nutrients, organic matter, and sedimentary processes, with reviews on more than two decades of intense study. Chapters reflect contributions from a variety of interdisciplinary sciences including botany, chemistry, ecology, geology, physics, and zoology.

  8. [Comparative investigation of locust's phototactic visual spectrum effect and phototactic response to spectral illumination].

    PubMed

    Liu, Qi-Hang; Zhou, Qiang

    2014-07-01

    To provide theoretical support for determining locust's phototactic spectrum, and explore locust's phototactic mechanism stimulated by light, utilizing AvaSpec fiber-optic spectrometer system and AvaLight-DHS, the investigation of locust's phototactic visual spectrum effect after light energy stimulated locust's vision system was carried out and on this basis, utilizing the investigated device of locust's phototactic response to spectral illumination, the discrepancy of locust's phototactic response to spectral illumination was certificated comparatively. The results show that the degree of locust's vision system absorbing the single spectrum photon of 430, 545 and 610 nm is significant and there exists difference, and the behavioral response to orange, violet, green, and blue spectral light has the difference in selective sensitivity, with the intensity of response to violet light being the strongest. The degree of response to orange light is the maximum, simultaneously, locust's vision system absorbing spectral photon energy has selective difference and requirement of illumination time, moreover, the sensitive degree of locust's visual system to spectrum and the strength of the lighting energy, influencing locust's phototactic response degree, and the micro-response of locust's phototactic vision physiology, led by the photoelectric effect of locust absorbing sensitive photon and converting photon energy, is the reason for locust's phototactic orientation response. In addition, locust's phototactic visual spectrum effect, only when the biological photoelectric effect of locust's visual system is stimulated by spectral illumination, can present the sensitivity of the spectral absorption effect, so, using the stronger ultraviolet stimulation characteristic of violet light, the different sensitive stimulation of orange, green, blue spectral light on locust's phototactic vision, and combining orange, violet, green, blue spectral light field mechanism reasonably, can

  9. Investigating Nigerian Primary School Teachers' Preparedness to Adopt Personal Response System in ESL Classroom

    ERIC Educational Resources Information Center

    Agbatogun, Alaba Olaoluwakotansibe

    2012-01-01

    This study investigated the extent to which computer literacy dimensions (computer general knowledge, documents and documentations, communication and surfing as well as data inquiry), computer use and academic qualification as independent variables predicted primary school teachers' attitude towards the integration of Personal Response System in…

  10. An Investigation of Science Educators' View of Roles and Responsibilities for Climate Change Education

    ERIC Educational Resources Information Center

    McGinnis, J. Randy; McDonald, Chris; Hestness, Emily; Breslyn, Wayne

    2016-01-01

    This exploratory study investigates what science educators from differing groups (outside of higher education--informal and formal (K-12) and inside of higher education--content and pedagogy experts) believe are the roles and responsibilities (and what actions these might involve) in climate change education for: 1) their group of educators, and…

  11. Colony-specific investigations reveal highly variable responses among individual corals to ocean acidification and warming.

    PubMed

    Kavousi, Javid; Reimer, James Davis; Tanaka, Yasuaki; Nakamura, Takashi

    2015-08-01

    As anthropogenic climate change is an ongoing concern, scientific investigations on its impacts on coral reefs are increasing. Although impacts of combined ocean acidification (OA) and temperature stress (T) on reef-building scleractinian corals have been studied at the genus, species and population levels, there are little data available on how individual corals respond to combined OA and anomalous temperatures. In this study, we exposed individual colonies of Acropora digitifera, Montipora digitata and Porites cylindrica to four pCO2-temperature treatments including 400 μatm-28 °C, 400 μatm-31 °C, 1000 μatm-28 °C and 1000 μatm-31 °C for 26 days. Physiological parameters including calcification, protein content, maximum photosynthetic efficiency, Symbiodinium density, and chlorophyll content along with Symbiodinium type of each colony were examined. Along with intercolonial responses, responses of individual colonies versus pooled data to the treatments were investigated. The main results were: 1) responses to either OA or T or their combination were different between individual colonies when considering physiological functions; 2) tolerance to either OA or T was not synonymous with tolerance to the other parameter; 3) tolerance to both OA and T did not necessarily lead to tolerance of OA and T combined (OAT) at the same time; 4) OAT had negative, positive or no impacts on physiological functions of coral colonies; and 5) pooled data were not representative of responses of all individual colonies. Indeed, the pooled data obscured actual responses of individual colonies or presented a response that was not observed in any individual. From the results of this study we recommend improving experimental designs of studies investigating physiological responses of corals to climate change by complementing them with colony-specific examinations.

  12. Temporal change of photophobic step-up responses of Euglena gracilis investigated through motion analysis.

    PubMed

    Ozasa, Kazunari; Won, June; Song, Simon; Tamaki, Shun; Ishikawa, Takahiro; Maeda, Mizuo

    2017-01-01

    The adaptation to a strong light is one of the essential characteristics of green algae, yet lacking relatively the information about the photophobic responses of Eukaryotic microalgae. We investigated the photophobic step-up responses of Euglena gracilis over a time course of several hours with alternated repetition of blue-light pulse illumination and spatially patterned blue-light illumination. Four distinctive photophobic motions in response to strong blue light were identified in a trace image analysis, namely on-site rotation, running and tumbling, continuous circular swimming, and unaffected straightforward swimming. The cells cultured in autotrophic conditions under weak light showed mainly the on-site rotation response at the beginning of blue-light illumination, but they acquired more blue-light tolerant responses of running and tumbling, circular swimming, or straightforward swimming. The efficiency of escaping from a blue-light illuminated area improved markedly with the development of these photophobic motions. Time constant of 3.0 h was deduced for the evolution of photophobic responses of E. gracilis. The nutrient-rich metabolic status of the cells resulting from photosynthesis during the experiments, i.e., the accumulation of photosynthesized nutrient products in balance between formation and consumption, was the main factor responsible for the development of photophobic responses. The reduction-oxidation status in and around E. gracilis cells did not affect their photophobic responses significantly, unlike the case of photophobic responses and phototaxis of Chlamydomonas reinhardtii cells. This study shows that the evolution of photophobic motion type of E. gracilis is dominated mainly by the nutrient metabolic status of the cells. The fact suggests that the nutrient-rich cells have a higher threshold for switching the flagellar motion from straightforward swimming to rotation under a strong light.

  13. Temporal change of photophobic step-up responses of Euglena gracilis investigated through motion analysis

    PubMed Central

    Ozasa, Kazunari; Won, June; Song, Simon; Tamaki, Shun; Ishikawa, Takahiro; Maeda, Mizuo

    2017-01-01

    The adaptation to a strong light is one of the essential characteristics of green algae, yet lacking relatively the information about the photophobic responses of Eukaryotic microalgae. We investigated the photophobic step-up responses of Euglena gracilis over a time course of several hours with alternated repetition of blue-light pulse illumination and spatially patterned blue-light illumination. Four distinctive photophobic motions in response to strong blue light were identified in a trace image analysis, namely on-site rotation, running and tumbling, continuous circular swimming, and unaffected straightforward swimming. The cells cultured in autotrophic conditions under weak light showed mainly the on-site rotation response at the beginning of blue-light illumination, but they acquired more blue-light tolerant responses of running and tumbling, circular swimming, or straightforward swimming. The efficiency of escaping from a blue-light illuminated area improved markedly with the development of these photophobic motions. Time constant of 3.0 h was deduced for the evolution of photophobic responses of E. gracilis. The nutrient-rich metabolic status of the cells resulting from photosynthesis during the experiments, i.e., the accumulation of photosynthesized nutrient products in balance between formation and consumption, was the main factor responsible for the development of photophobic responses. The reduction-oxidation status in and around E. gracilis cells did not affect their photophobic responses significantly, unlike the case of photophobic responses and phototaxis of Chlamydomonas reinhardtii cells. This study shows that the evolution of photophobic motion type of E. gracilis is dominated mainly by the nutrient metabolic status of the cells. The fact suggests that the nutrient-rich cells have a higher threshold for switching the flagellar motion from straightforward swimming to rotation under a strong light. PMID:28234984

  14. Ecological Insights from Pelagic Habitats Acquired Using Active Acoustic Techniques

    NASA Astrophysics Data System (ADS)

    Benoit-Bird, Kelly J.; Lawson, Gareth L.

    2016-01-01

    Marine pelagic ecosystems present fascinating opportunities for ecological investigation but pose important methodological challenges for sampling. Active acoustic techniques involve producing sound and receiving signals from organisms and other water column sources, offering the benefit of high spatial and temporal resolution and, via integration into different platforms, the ability to make measurements spanning a range of spatial and temporal scales. As a consequence, a variety of questions concerning the ecology of pelagic systems lend themselves to active acoustics, ranging from organism-level investigations and physiological responses to the environment to ecosystem-level studies and climate. As technologies and data analysis methods have matured, the use of acoustics in ecological studies has grown rapidly. We explore the continued role of active acoustics in addressing questions concerning life in the ocean, highlight creative applications to key ecological themes ranging from physiology and behavior to biogeography and climate, and discuss emerging avenues where acoustics can help determine how pelagic ecosystems function.

  15. Ecological Insights from Pelagic Habitats Acquired Using Active Acoustic Techniques.

    PubMed

    Benoit-Bird, Kelly J; Lawson, Gareth L

    2016-01-01

    Marine pelagic ecosystems present fascinating opportunities for ecological investigation but pose important methodological challenges for sampling. Active acoustic techniques involve producing sound and receiving signals from organisms and other water column sources, offering the benefit of high spatial and temporal resolution and, via integration into different platforms, the ability to make measurements spanning a range of spatial and temporal scales. As a consequence, a variety of questions concerning the ecology of pelagic systems lend themselves to active acoustics, ranging from organism-level investigations and physiological responses to the environment to ecosystem-level studies and climate. As technologies and data analysis methods have matured, the use of acoustics in ecological studies has grown rapidly. We explore the continued role of active acoustics in addressing questions concerning life in the ocean, highlight creative applications to key ecological themes ranging from physiology and behavior to biogeography and climate, and discuss emerging avenues where acoustics can help determine how pelagic ecosystems function.

  16. Ecological Inference

    NASA Astrophysics Data System (ADS)

    King, Gary; Rosen, Ori; Tanner, Martin A.

    2004-09-01

    This collection of essays brings together a diverse group of scholars to survey the latest strategies for solving ecological inference problems in various fields. The last half-decade has witnessed an explosion of research in ecological inference--the process of trying to infer individual behavior from aggregate data. Although uncertainties and information lost in aggregation make ecological inference one of the most problematic types of research to rely on, these inferences are required in many academic fields, as well as by legislatures and the Courts in redistricting, by business in marketing research, and by governments in policy analysis.

  17. Sustainability evaluation of the Grain for Green Project: from local people's responses to ecological effectiveness in Wolong Nature Reserve.

    PubMed

    Xu, Jian-Ying; Chen, Li-Ding; Lu, Yi-He; Fu, Bo-Jie

    2007-07-01

    This article examines the sustainability of the Grain for Green Project in the Wolong Nature Reserve. Pertinent data were collected through a questionnaire survey and a spatial analysis of reforested lands. The study results identified four critical issues that may influence the sustainability of the project in the study area. The first issue is concerned with the project's impacts on local sustenance. Because local grain consumption depends greatly on compensation awarded by the project, the potential for sustainability of the project is compromised. The second issue is that the project causes negative effects on local incomes in the Wolong Nature Reserve, which may undermine local economic prospects. The third issue is that the project failed to deliver suitable habitat for the giant panda, although two of the suitability requirements that deal with landform features were met. Lastly, the project neglects great differences among geographical areas in the country, providing the same compensation and length of compensation period to all participants. Appropriate compensation mechanisms should be established and adapted to local economic, environmental, and social conditions. In managing nature reserves and moving toward sustainability, ensuring all aspects of local socioeconomic and ecological/environmental issues are properly addressed is a real challenge. Based on our study, some recommendations for improving sustainability of the project are given.

  18. Hydrologic, ecologic, and geomorphic responses of Brewery Creek to construction of a residential subdivision, Dane County, Wisconsin, 1999-2002

    USGS Publications Warehouse

    Selbig, William R.; Jopke, Peter L.; Marhshall, David W.; Sorge, Michael J.

    2004-01-01

    Other physical, biological, and ecological surveys including macroinvertebrates, fish, habitat, and geomorphology were done on segments of Brewery Creek affected by the study area. Macroinvertebrate sampling results (Hilsenhoff Biotic Index value, or HBI), on Brewery Creek ranged from 'very good' to 'good' water-quality with no appreciable differences during any phase of construction activity. Results for fish-community composition, however, were within the 'poor' range (Index of Biotic Integrity value, or IBI) during each year of testing. A general absence of intolerant species, with the exception of brown trout, reflects the low IBI values. Habitat values did not change significantly from preconstruction to postconstruction phases. Although installation of a double-celled culvert in Brewery Creek most likely altered the width-to-depth ratio in that reach, the overall habitat rating remained 'fair'. Fluvial geomorphology classifications including channel cross sections, bed- and bank-erosion surveys, and pebble counts did not indicate that stream geomorphic characteristics were altered by home-construction activity in the study area. Increases in fine-grained sediment at various cross sections were attributed to instream erosion processes, such as bank slumping, rather than increases in sediment delivery from the nearby construction site.

  19. Ecological ethics in captivity: balancing values and responsibilities in zoo and aquarium research under rapid global change.

    PubMed

    Minteer, Ben A; Collins, James P

    2013-01-01

    Ethical obligations to animals in conservation research and management are manifold and often conflicting. Animal welfare concerns often clash with the ethical imperative to understand and conserve a population or ecosystem through research and management intervention. The accelerating pace and impact of global environmental change, especially climate change, complicates our understanding of these obligations. One example is the blurring of the distinction between ex situ (zoo- and aquarium-based) conservation and in situ (field-based) approaches as zoos and aquariums become more active in field conservation work and as researchers and managers consider more intensive interventions in wild populations and ecosystems to meet key conservation goals. These shifts, in turn, have consequences for our traditional understanding of the ethics of wildlife research and management, including our relative weighting of animal welfare and conservation commitments across rapidly evolving ex situ and in situ contexts. Although this changing landscape in many ways supports the increased use of captive wildlife in conservation-relevant research, it raises significant ethical concerns about human intervention in populations and ecosystems, including the proper role of zoos and aquariums as centers for animal research and conservation in the coming decades. Working through these concerns requires a pragmatic approach to ethical analysis, one that is able to make trade-offs among the many goods at stake (e.g., animal welfare, species viability, and ecological integrity) as we strive to protect species from further decline and extinction in this century.

  20. Sustainability Evaluation of the Grain for Green Project: From Local People's Responses to Ecological Effectiveness in Wolong Nature Reserve

    NASA Astrophysics Data System (ADS)

    Xu, Jian-Ying; Chen, Li-Ding; Lu, Yi-He; Fu, Bo-Jie

    2007-07-01

    This article examines the sustainability of the Grain for Green Project in the Wolong Nature Reserve. Pertinent data were collected through a questionnaire survey and a spatial analysis of reforested lands. The study results identified four critical issues that may influence the sustainability of the project in the study area. The first issue is concerned with the project’s impacts on local sustenance. Because local grain consumption depends greatly on compensation awarded by the project, the potential for sustainability of the project is compromised. The second issue is that the project causes negative effects on local incomes in the Wolong Nature Reserve, which may undermine local economic prospects. The third issue is that the project failed to deliver suitable habitat for the giant panda, although two of the suitability requirements that deal with landform features were met. Lastly, the project neglects great differences among geographical areas in the country, providing the same compensation and length of compensation period to all participants. Appropriate compensation mechanisms should be established and adapted to local economic, environmental, and social conditions. In managing nature reserves and moving toward sustainability, ensuring all aspects of local socioeconomic and ecological/environmental issues are properly addressed is a real challenge. Based on our study, some recommendations for improving sustainability of the project are given.

  1. Acute effects of cocaine and cannabis on response inhibition in humans: an ERP investigation.

    PubMed

    Spronk, Desirée B; De Bruijn, Ellen R A; van Wel, Janelle H P; Ramaekers, Johannes G; Verkes, Robbert J

    2016-11-01

    Substance abuse has often been associated with alterations in response inhibition in humans. Not much research has examined how the acute effects of drugs modify the neurophysiological correlates of response inhibition, or how these effects interact with individual variation in trait levels of impulsivity and novelty seeking. This study investigated the effects of cocaine and cannabis on behavioural and event-related potential (ERP) correlates of response inhibition in 38 healthy drug using volunteers. A double-blind placebo-controlled randomized three-way crossover design was used. All subjects completed a standard Go/NoGo task after administration of the drugs. Compared with a placebo, cocaine yielded improved accuracy, quicker reaction times and an increased prefrontal NoGo-P3 ERP. Cannabis produced opposing results; slower reaction times, impaired accuracy and a reduction in the amplitude of the prefrontal NoGo-P3. Cannabis in addition decreased the amplitude of the parietally recorded P3, while cocaine did not affect this. Neither drugs specifically affected the N2 component, suggesting that pre-motor response inhibitory processes remain unaffected. Neither trait impulsivity nor novelty seeking interacted with drug-induced effects on measures of response inhibition. We conclude that acute drug effects on response inhibition seem to be specific to the later, evaluative stages of response inhibition. The acute effects of cannabis appeared less specific to response inhibition than those of cocaine. Together, the results show that the behavioural effects on response inhibition are reflected in electrophysiological correlates. This study did not support a substantial role of vulnerability personality traits in the acute intoxication stage.

  2. Simultaneous optical and mechanical probes to investigate complex cellular responses to physical cues

    NASA Astrophysics Data System (ADS)

    Haase, Kristina; Al-Rekabi, Zeinab; Guolla, Louise; Hickey, Ryan; Tremblay, Dominique; Pelling, Andrew E.

    2015-03-01

    Living cells possess an exquisite ability to sense and respond to physical information in their microenvironment. This ability plays a key role in many fundamentally important physiological and pathological processes. We will describe our work utilizing a variety of biophysical tools to investigate the dynamic responses of cells to mechanical stimuli and how physical cues can be employed to re-purpose and manipulate biological processes. These responses to physical cues are not simply a side-product of biology but are key components of biological and physical feedback loops that govern the life of a cell.

  3. Cognitive ecology.

    PubMed

    Hutchins, Edwin

    2010-10-01

    Cognitive ecology is the study of cognitive phenomena in context. In particular, it points to the web of mutual dependence among the elements of a cognitive ecosystem. At least three fields were taking a deeply ecological approach to cognition 30 years ago: Gibson's ecological psychology, Bateson's ecology of mind, and Soviet cultural-historical activity theory. The ideas developed in those projects have now found a place in modern views of embodied, situated, distributed cognition. As cognitive theory continues to shift from units of analysis defined by inherent properties of the elements to units defined in terms of dynamic patterns of correlation across elements, the study of cognitive ecosystems will become an increasingly important part of cognitive science.

  4. [Ecological memory and its potential applications in ecology: a review].

    PubMed

    Sun, Zhong-yu; Ren, Hai

    2011-03-01

    Ecological memory (EM) is defined as the capability of the past states or experiences of a community to influence the present or future ecological responses of the community. As a relatively new concept, EM has received considerable attention in the study of ecosystem structure and function, such as community succession, ecological restoration, biological invasion, and natural resource management. This review summarized the definition, components, and categories of EM, and discussed the possible mechanisms and affecting factors of EM. Also, the potential applications of EM were proposed, in order to further understand the mechanisms of community succession and to guide ecological restoration.

  5. Investigation of Constant Temperature Hot-wire System Response using Laser Pulse

    NASA Astrophysics Data System (ADS)

    Jaffa, Nicholas; Morris, Scott; Cameron, Joshua

    2016-11-01

    Constant temperature hot-wire systems use a Wheatstone bridge and feedback amplifier circuit to maintain a constant average temperature across the wire yielding frequency responses of order 100 kHz. This high frequency response allows hot-wires to be used extensively for aerodynamic measurements in high speed flows and uncertainty at these high frequencies can be difficult to diagnose. The standard frequency response check for constant temperature hot-wires uses an electronic pulse across the circuit to check the electronic feedback circuit response time, but does not account for the impact of the heat transfer along the wire. In order to investigate the frequency response of the entire constant temperature hot-wire system, including the heat transfer along the wire, a novel method was developed using a pulsed PIV laser focused to illuminate only the hot-wire. The laser pulse duration was effectively an instantaneous change in wire surface temperature through radiation. A hot-wire was placed in a uniform open calibration jet for a range of flow conditions. The response of the entire hot-wire system was observed across a range of conditions including changes in flow, wire temperature, and thermal boundary conditions and compared with the electronic pulse test.

  6. Investigating Power System Primary and Secondary Reserve Interaction under High Wind Penetration Using Frequency Response Model

    SciTech Connect

    Tan, Jin; Zhang, Yingchen; Krad, Ibrahim; Gevorgian, Vahan; Ela, Erik

    2015-10-12

    Power system frequency needs to be maintained close to its nominal value at all times to avoid machine damage, under-frequency load-shedding and even blackouts. Adequate primary frequency response and secondary frequency response are the primary forces to correct an energy imbalance at the second to minute level. As wind energy becomes a larger portion of the world's energy portfolio, there are greater oppotunities for wind to provide frequency response services. This paper addresses one area of frequency control that has been missing in previous work - the reliabilty impacts and interactions between primary and secondary frequency control. The lack of a commercially available tools to simulate the interaction of these two responses has limited the energy industry's understanding of when the depletion of primary control reserve will impact the performance of secondary conrol response or vice versa. To investigate this issue, in this paper we develop a multi-area frequency response integration model with combined primary and secondary frequency control capabilities.

  7. Constructing ecologies.

    PubMed

    Cropp, Roger; Norbury, John

    2012-02-07

    We synthesize the generic properties of ecologically realistic multi-trophic level models and define criteria for ecological realism. We define an "ecospace" in which all ecologically realistic dynamics are confined, and construct "resource rays" that define the resources available to each species at every point in the ecospace. Resource rays for a species are lines from a vertex of maximum resource to the opposite boundary where no resources are available. The growth functions of all biota normally decrease along their resource rays, and change sign from positive to negative. This property prescribes that each species must have a zero isosurface within the ecospace. We illustrate our conditions on a highly cited three trophic level model from population dynamics, showing how to extend this system biologically consistently to a closed ecological system. Our synthesis extends the concept of carrying capacity of population models to explicitly include exhaustion of limiting resources, and so allows for population biology models to be considered as ecologically closed systems with respect to a key limiting nutrient. This approach unifies many theoretical and applied models in a common biogeochemical framework, facilitates better understanding of the key structures of complex ecologies, and suggests strategies for efficient design of experiments.

  8. Preventing regime shifts on the Colorado Plateau: Application of ecological threshold concepts to land management decision making

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Investigating the mechanisms responsible for ecological thresholds is essential to understanding processes leading to ecosystem regime shifts. Dryland ecosystems are especially prone to threshold behavior wherein stressor-mediated alteration of patterns and processes can shift systems to alternative...

  9. Ultrasonographic Investigation of Human Fetus Responses to Maternal Communicative and Non-communicative Stimuli

    PubMed Central

    Ferrari, Gabriella A.; Nicolini, Ylenia; Demuru, Elisa; Tosato, Cecilia; Hussain, Merhi; Scesa, Elena; Romei, Luisa; Boerci, Maria; Iappini, Emanuela; Dalla Rosa Prati, Guido; Palagi, Elisabetta; Ferrari, Pier F.

    2016-01-01

    During pregnancy fetuses are responsive to the external environment, specifically to maternal stimulation. During this period, brain circuits develop to prepare neonates to respond appropriately. The detailed behavioral analysis of fetus’ mouth movements in response to mothers’ speech may reveal important aspects of their sensorimotor and affective skills; however, to date, no studies have investigated this response. Given that newborns at birth are capable of responding with matched behaviors to the social signals emitted by the caregiver, we hypothesize that such precocious responses could emerge in the prenatal period by exploiting infants’ sensitivity to their mother’s voice. By means of a two-dimensional (2D) ultrasonography, we assessed whether fetuses at 25 weeks of gestation, showed a congruent mouthmotor response to maternal acoustic stimulation. Mothers were asked to provide different stimuli, each characterized by a different acoustic output (e.g., chewing, yawning, nursery rhymes, etc.) and we recorded the behavioral responses of 29 fetuses. We found that, when mothers sang the syllable LA in a nursery rhyme, fetuses significantly increased mouth openings. Other stimuli provided by the mother did not produce other significant changes in fetus’ behavior. This finding suggests that fetuses are sensitive only to specific maternal vocalizations (LA) and that fetal matched responses are rudimentary signs of early mirroring behaviors that become functional in the postnatal period. In conclusion, fetuses seem to be predisposed to respond selectively to specific maternal stimuli. We propose that such responses may play a role in the development of behavioral and emotional attunement with their mothers long before birth. PMID:27014160

  10. Functional Molecular Ecological Networks

    PubMed Central

    Zhou, Jizhong; Deng, Ye; Luo, Feng; He, Zhili; Tu, Qichao; Zhi, Xiaoyang

    2010-01-01

    Biodiversity and its responses to environmental changes are central issues in ecology and for society. Almost all microbial biodiversity research focuses on “species” richness and abundance but not on their interactions. Although a network approach is powerful in describing ecological interactions among species, defining the network structure in a microbial community is a great challenge. Also, although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity are well established, its influences on belowground microbial communities, especially microbial interactions, are poorly understood. Here, a random matrix theory (RMT)-based conceptual framework for identifying functional molecular ecological networks was developed with the high-throughput functional gene array hybridization data of soil microbial communities in a long-term grassland FACE (free air, CO2 enrichment) experiment. Our results indicate that RMT is powerful in identifying functional molecular ecological networks in microbial communities. Both functional molecular ecological networks under eCO2 and ambient CO2 (aCO2) possessed the general characteristics of complex systems such as scale free, small world, modular, and hierarchical. However, the topological structures of the functional molecular ecological networks are distinctly different between eCO2 and aCO2, at the levels of the entire communities, individual functional gene categories/groups, and functional genes/sequences, suggesting that eCO2 dramatically altered the network interactions among different microbial functional genes/populations. Such a shift in network structure is also significantly correlated with soil geochemical variables. In short, elucidating network interactions in microbial communities and their responses to environmental changes is fundamentally important for research in microbial ecology, systems microbiology, and global change. PMID:20941329

  11. Investigations into the triggered lightning response of the F106B thunderstorm research aircraft

    NASA Technical Reports Server (NTRS)

    Rudolph, Terence H.; Perala, Rodney A.; Mckenna, Paul M.; Parker, Steven L.

    1985-01-01

    An investigation has been conducted into the lightning characteristics of the NASA F106B thunderstorm research aircraft. The investigation includes analysis of measured data from the aircraft in the time and frequency domains. Linear and nonlinear computer modelling has also been performed. In addition, new computer tools have been developed, including a new enhanced nonlinear air breakdown model, and a subgrid model useful for analyzing fine details of the aircraft's geometry. Comparison of measured and calculated electromagnetic responses of the aircraft to a triggered lightning environment are presented.

  12. Investigation on spectral response of micro-cavity structure by symmetrical tapered fiber tips

    NASA Astrophysics Data System (ADS)

    Liu, Yan; Li, Yang; Yan, Xiaojun; Li, Weidong

    2016-06-01

    We proposed and experimentally demonstrated a micro-cavity structure made of symmetrical tapered fiber tips. The waist of a conventional fiber taper fabricated from heating and stretching technique is symmetrically cleaved, and the aligned fiber tips with air gap constitute a Fabry-Perot micro-cavity due to the reflection at the tip facet. The spectral responses of such micro-cavity structure have been investigated both in beam propagation models and experiments. The multibeam interference in the micro-cavity and the impact of the waist diameter and cavity length on the spectral response has been successfully demonstrated. And a micro-cavity structure with 45 μm waist diameter was experimentally achieved, the measured spectra agree well with the simulation ones, indicating that the spectral response of the micro-cavity structure is contributed by both the multibeam interference and the Fabry-Perot micro-cavity.

  13. Experimental investigation of the shock response of bismuth under one-dimensional shock-loading

    NASA Astrophysics Data System (ADS)

    Whiteman, Glenn; Millett, Jeremy; Appleby-Thomas, Gareth; Wood, David; Hameed, Amer

    2017-01-01

    Interest in the dynamic response of bismuth is largely derived from the existence of multiple phase transitions attainable with increasing pressure. In addition, its industrial use has grown in recent years (e.g. in solder as a replacement for lead), in part due to its relatively low toxicity. While some shock experiments have been conducted on bismuth they have largely concentrated on equation of state research at relatively low stresses. To the authors' knowledge the strength behaviour under shock is not prevalent in the literature. To this end, the low pressure response of bismuth targets has been experimentally investigated here using commercial stress gauges mounted in both longitudinal and lateral orientation with respect to the loading axis. Of particular note was the potential to observe the relatively low pressure phase transitions in the lateral stress response.

  14. Investigation of the Gracilaria gracilis (Gracilariales, Rhodophyta) proteome response to nitrogen limitation.

    PubMed

    Naidoo, Rene K; Rafudeen, Muhammad S; Coyne, Vernon E

    2016-06-01

    Inorganic nitrogen has been identified as the major growth-limiting nutritional factor affecting Gracilaria gracilis populations in South Africa. Although the physiological mechanisms implemented by G. gracilis for adaption to low nitrogen environments have been investigated, little is known about the molecular mechanisms of these adaptions. This study provides the first investigation of G. gracilis proteome changes in response to nitrogen limitation and subsequent recovery. A differential proteomics approach employing two-dimensional gel electrophoresis and liquid chromatography-tandem mass spectrometry was used to investigate G. gracilis proteome changes in response to nitrogen limitation and recovery. The putative identity of 22 proteins that changed significantly (P < 0.05) in abundance in response to nitrogen limitation and recovery was determined. The identified proteins function in a range of biological processes including glycolysis, photosynthesis, ATP synthesis, galactose metabolism, protein-refolding and biosynthesis, nitrogen metabolism and cytoskeleton remodeling. The identity of fructose 1,6 biphosphate (FBP) aldolase was confirmed by western blot analysis and the decreased abundance of FBP aldolase observed with two-dimensional gel electrophoresis was validated by enzyme assays and western blots. The identification of key proteins and pathways involved in the G. gracilis nitrogen stress response provide a better understanding of G. gracilis proteome responses to varying degrees of nitrogen limitation and is the first step in the identification of biomarkers for monitoring the nitrogen status of cultivated G. gracilis populations.

  15. Investigation of Biomechanical Response Due to Fragment Impact on Ballistic Protective Helmet.

    DTIC Science & Technology

    1998-03-01

    Investigation of Biomechanical Response Due to Fragment Impact on Ballistic Protective Helmet 5. FUNDING NUMBERS 6. AUTHOR( S ) King, Quinten M 7...fragments traveling in excess of 2000 ft/ s (609 m/ s ). However, these strides have also exposed the body to greater impact energies without a...development of personnel body armor capable of preventing penetration of fragments traveling in excess of 2000 ft/ s (609 m/ s ). However these strides have

  16. Fundamental Investigation of the Microstructural Parameters to Improve Dynamic Response in Al-Cu Model System

    DTIC Science & Technology

    2014-05-01

    better engineer and optimize the properties of aluminum alloys for high strain rate applications.The composition of these alloys are shown in Table 4...rate application aluminum alloys . In A. Bajaj, P. Zavattieri, M. Koslowski, & T. Siegmund (Eds.). Proceedings of the Society of Engineering Science...chemistry on deformation in a series of model aluminum alloy systems were investigated in an attempt to understand the dominant features responsible for the

  17. Investigation of pitch motion portion in vertical response at sides of a Tension-Leg Platform

    NASA Astrophysics Data System (ADS)

    Tabeshpour, Mohammad Reza; Malayjerdi, Ebrahim

    2016-06-01

    Tendons vertically moor Tension-Leg Platforms (TLPs), thus, a deep understanding of physical tendon stresses requires the determination of the total axial deformation of the tendons, which is a combination of the heave, pitch, and surging responses. The vertical motion of the lateral sides of the TLP is coupled with surge and constitutes a portion of the pitch motion. Tendons are connected to the sides of the TLP; hence, the total displacement of the lateral sides is related to the total deformation of the tendons and the total axial stress. Therefore, investigating the total vertical response at the sides of the TLP is essential. The coupling between various degrees of freedom is not considered in the Response Amplitude Operator (RAO). Therefore, in frequency domain analysis, the estimated vertical RAO is incomplete. Also, in the time domain, only the heave motion at the center of TLP is typically studied; this problem needs to be addressed. In this paper, we investigate the portion of the pitch motion in the vertical response at the sides of the TLP in both the frequency and time domains. Numerical results demonstrate a significant effect of the pitch motion in the vertical motion of the edges of the TLP in some period ranges.

  18. Ecology-centered experiences among children and adolescents: A qualitative and quantitative analysis

    NASA Astrophysics Data System (ADS)

    Orton, Judy

    The present research involved two studies that considered ecology-centered experiences (i.e., experiences with living things) as a factor in children's environmental attitudes and behaviors and adolescents' ecological understanding. The first study (Study 1) examined how a community garden provides children in an urban setting the opportunity to learn about ecology through ecology-centered experiences. To do this, I carried out a yearlong ethnographic study at an urban community garden located in a large city in the Southeastern United States. Through participant observations and informal interviews of community garden staff and participants, I found children had opportunities to learn about ecology through ecology-centered experiences (e.g., interaction with animals) along with other experiences (e.g., playing games, reading books). In light of previous research that shows urban children have diminished ecological thought---a pattern of thought that privileges the relationship between living things---because of their lack of ecology-centered experiences (Coley, 2012), the present study may have implications for urban children to learn about ecology. As an extension of Study 1, I carried out a second study (Study 2) to investigate how ecology-centered experiences contribute to adolescents' environmental attitudes and behaviors in light of other contextual factors, namely environmental responsibility support, ecological thought, age and gender. Study 2 addressed three research questions. First, does ecological thought---a pattern of thought that privileges the relationship between living things---predict environmental attitudes and behaviors (EAB)? Results showed ecological thought did not predict EAB, an important finding considering the latent assumptions of previous research about the relationship between these two factors (e.g., Brugger, Kaiser, & Roczen, 2011). Second, do two types of contextual support, ecology-centered experiences (i.e., experiences with

  19. Echoic memory: investigation of its temporal resolution by auditory offset cortical responses.

    PubMed

    Nishihara, Makoto; Inui, Koji; Morita, Tomoyo; Kodaira, Minori; Mochizuki, Hideki; Otsuru, Naofumi; Motomura, Eishi; Ushida, Takahiro; Kakigi, Ryusuke

    2014-01-01

    Previous studies showed that the amplitude and latency of the auditory offset cortical response depended on the history of the sound, which implicated the involvement of echoic memory in shaping a response. When a brief sound was repeated, the latency of the offset response depended precisely on the frequency of the repeat, indicating that the brain recognized the timing of the offset by using information on the repeat frequency stored in memory. In the present study, we investigated the temporal resolution of sensory storage by measuring auditory offset responses with magnetoencephalography (MEG). The offset of a train of clicks for 1 s elicited a clear magnetic response at approximately 60 ms (Off-P50m). The latency of Off-P50m depended on the inter-stimulus interval (ISI) of the click train, which was the longest at 40 ms (25 Hz) and became shorter with shorter ISIs (2.5∼20 ms). The correlation coefficient r2 for the peak latency and ISI was as high as 0.99, which suggested that sensory storage for the stimulation frequency accurately determined the Off-P50m latency. Statistical analysis revealed that the latency of all pairs, except for that between 200 and 400 Hz, was significantly different, indicating the very high temporal resolution of sensory storage at approximately 5 ms.

  20. Investigation of Response Amplitude Operators for Floating Offshore Wind Turbines: Preprint

    SciTech Connect

    Ramachandran, G. K. V.; Robertson, A.; Jonkman, J. M.; Masciola, M. D.

    2013-07-01

    This paper examines the consistency between response amplitude operators (RAOs) computed from WAMIT, a linear frequency-domain tool, to RAOs derived from time-domain computations based on white-noise wave excitation using FAST, a nonlinear aero-hydro-servo-elastic tool. The RAO comparison is first made for a rigid floating wind turbine without wind excitation. The investigation is further extended to examine how these RAOs change for a flexible and operational wind turbine. The RAOs are computed for below-rated, rated, and above-rated wind conditions. The method is applied to a floating wind system composed of the OC3-Hywind spar buoy and NREL 5-MW wind turbine. The responses are compared between FAST and WAMIT to verify the FAST model and to understand the influence of structural flexibility, aerodynamic damping, control actions, and waves on the system responses. The results show that based on the RAO computation procedure implemented, the WAMIT- and FAST-computed RAOs are similar (as expected) for a rigid turbine subjected to waves only. However, WAMIT is unable to model the excitation from a flexible turbine. Further, the presence of aerodynamic damping decreased the platform surge and pitch responses, as computed by both WAMIT and FAST when wind was included. Additionally, the influence of gyroscopic excitation increased the yaw response, which was captured by both WAMIT and FAST.

  1. Art expertise modulates the emotional response to modern art, especially abstract: an ERP investigation.

    PubMed

    Else, Jane E; Ellis, Jason; Orme, Elizabeth

    2015-01-01

    Art is one of life's great joys, whether it is beautiful, ugly, sublime or shocking. Aesthetic responses to visual art involve sensory, cognitive and visceral processes. Neuroimaging studies have yielded a wealth of information regarding aesthetic appreciation and beauty using visual art as stimuli, but few have considered the effect of expertise on visual and visceral responses. To study the time course of visual, cognitive and emotional processes in response to visual art we investigated the event-related potentials (ERPs) elicited whilst viewing and rating the visceral affect of three categories of visual art. Two groups, artists and non-artists viewed representational, abstract and indeterminate 20th century art. Early components, particularly the N1, related to attention and effort, and the P2, linked to higher order visual processing, was enhanced for artists when compared to non-artists. This effect was present for all types of art, but further enhanced for abstract art (AA), which was rated as having lowest visceral affect by the non-artists. The later, slow wave processes (500-1000 ms), associated with arousal and sustained attention, also show clear differences between the two groups in response to both type of art and visceral affect. AA increased arousal and sustained attention in artists, whilst it decreased in non-artists. These results suggest that aesthetic response to visual art is affected by both expertise and semantic content.

  2. Art expertise modulates the emotional response to modern art, especially abstract: an ERP investigation

    PubMed Central

    Else, Jane E.; Ellis, Jason; Orme, Elizabeth

    2015-01-01

    Art is one of life’s great joys, whether it is beautiful, ugly, sublime or shocking. Aesthetic responses to visual art involve sensory, cognitive and visceral processes. Neuroimaging studies have yielded a wealth of information regarding aesthetic appreciation and beauty using visual art as stimuli, but few have considered the effect of expertise on visual and visceral responses. To study the time course of visual, cognitive and emotional processes in response to visual art we investigated the event-related potentials (ERPs) elicited whilst viewing and rating the visceral affect of three categories of visual art. Two groups, artists and non-artists viewed representational, abstract and indeterminate 20th century art. Early components, particularly the N1, related to attention and effort, and the P2, linked to higher order visual processing, was enhanced for artists when compared to non-artists. This effect was present for all types of art, but further enhanced for abstract art (AA), which was rated as having lowest visceral affect by the non-artists. The later, slow wave processes (500–1000 ms), associated with arousal and sustained attention, also show clear differences between the two groups in response to both type of art and visceral affect. AA increased arousal and sustained attention in artists, whilst it decreased in non-artists. These results suggest that aesthetic response to visual art is affected by both expertise and semantic content. PMID:27242497

  3. Ecological epigenetics.

    PubMed

    Kilvitis, Holly J; Alvarez, Mariano; Foust, Christy M; Schrey, Aaron W; Robertson, Marta; Richards, Christina L

    2014-01-01

    Biologists have assumed that heritable variation due to DNA sequence differences (i.e., genetic variation) allows populations of organisms to be both robust and adaptable to extreme environmental conditions. Natural selection acts on the variation among different genotypes and ultimately changes the genetic composition of the population. While there is compelling evidence about the importance of genetic polymorphisms, evidence is accumulating that epigenetic mechanisms (e.g., chromatin modifications, DNA methylation) can affect ecologically important traits, even in the absence of genetic variation. In this chapter, we review this evidence and discuss the consequences of epigenetic variation in natural populations. We begin by defining the term epigenetics, providing a brief overview of various epigenetic mechanisms, and noting the potential importance of epigenetics in the study of ecology. We continue with a review of the ecological epigenetics literature to demonstrate what is currently known about the amount and distribution of epigenetic variation in natural populations. Then, we consider the various ecological contexts in which epigenetics has proven particularly insightful and discuss the potential evolutionary consequences of epigenetic variation. Finally, we conclude with suggestions for future directions of ecological epigenetics research.

  4. Investigation of the nonlinear response of turbulent premixed flames to imposed inlet velocity oscillations

    SciTech Connect

    Armitage, C.A.; Mastorakos, E.; Cant, R.S.; Balachandran, R.

    2006-08-15

    Acoustically forced lean premixed turbulent bluff-body stabilized flames are investigated using turbulent combustion CFD. The calculations simulate aspects of the experimental investigation by Balachandran et al. [R. Balachandran, B. Ayoola, C. Kaminski, A. Dowling, E. Mastorakos, Combust. Flame 143 (2005) 37-55] and focus on the amplitude dependence of the flame response. For the frequencies of interest in this investigation an unsteady Reynolds-averaged Navier-Stokes (URANS) approach is appropriate. The combustion is represented using a modified laminar flamelet approach with an algebraic representation of the flame surface density. The predictions are compared with flame surface density (FSD) and OH* chemiluminescence measurements. In the experiments the response of the flame has been quantified by means of a number of single-frequency, amplitude-dependent transfer functions. The predicted flame shape and position are in good agreement with the experiment. The dynamic response of the flame to inlet velocity forcing is also well captured by the calculations. At moderate frequencies nonlinear behavior of the transfer functions is observed as the forcing amplitude is increased. In the experiments this nonlinearity was attributed in part to the rollup of the reacting shear layer into vortices and in part to the collision of the inner and outer flame sheets. This transition to nonlinearity is also observed in the transfer functions obtained from the predictions. Furthermore, the vortex shedding and flame-sheet collapse may be seen in snapshots of the predicted flow field taken throughout the forcing cycle. The URANS methodology successfully predicts the behavior of the forced premixed turbulent flames and captures the effects of saturation in the transfer function of the response of the heat release to velocity fluctuations. (author)

  5. Negative feedback adjustment challenges reconstruction study from tree rings: A study case of response of Populus euphratica to river discontinuous flow and ecological water conveyance.

    PubMed

    Ling, Hongbo; Zhang, Pei; Guo, Bin; Xu, Hailiang; Ye, Mao; Deng, Xiaoya

    2017-01-01

    Drought stress changes the relationship between the growth of tree rings and variations in ambient temperature. However, it is not clear how the growth of trees changes in response to drought of varying intensities, especially in arid areas. Therefore, Tree rings were studied for 6years in Populus euphratica to assess the impacts of abrupt changes in environment on tree rings using the theories and methods in dendrohydrology, ecology and phytophysiology. The width of tree rings increased by 8.7% after ecological water conveyance downstream of Tarim River compared to that when the river water had been cut off. However, during intermediate drought, as the depth of the groundwater increases, the downward trend in the tree rings was reversed because of changes in the physiology of the tree. Therefore, the growth of tree rings shows a negative feedback to intermediate drought stress, an observation that challenges the homogenization theory of tree ring reconstruction based on the traditional methods. Owing to the time lag, the cumulative effect and the negative feedback between the growth of tree rings and drought stress, the reconstruction of past environment by studying the patterns of tree rings is often inaccurate. Our research sets out to verify the hypothesis that intermediate drought stress results in a negative feedback adjustment and thus to answers two scientific questions: (1) How does the negative feedback adjustment promote the growth of tree rings as a result of intermediate drought stress? (2) How does the negative feedback adjustment lower the accuracy with which the past is reconstructed based on tree rings? This research not only enriches the connotations of intermediate disturbance hypothesis and reconstruction theory of tree rings, but also provides a scientific basis for the conservation of desert riparian forests worldwide.

  6. Ecological genomics of tropical trees: how local population size and allelic diversity of resistance genes relate to immune responses, cosusceptibility to pathogens, and negative density dependence.

    PubMed

    Marden, J H; Mangan, S A; Peterson, M P; Wafula, E; Fescemyer, H W; Der, J P; dePamphilis, C W; Comita, L S

    2017-01-02

    In tropical forests, rarer species show increased sensitivity to species-specific soil pathogens and more negative effects of conspecific density on seedling survival (NDD). These patterns suggest a connection between ecology and immunity, perhaps because small population size disproportionately reduces genetic diversity of hyperdiverse loci such as immunity genes. In an experiment examining seedling roots from six species in one tropical tree community, we found that smaller populations have reduced amino acid diversity in pathogen resistance (R) genes but not the transcriptome in general. Normalized R gene amino acid diversity varied with local abundance and prior measures of differences in sensitivity to conspecific soil and NDD. After exposure to live soil, species with lower R gene diversity had reduced defence gene induction, more cosusceptibility of maternal cohorts to colonization by potentially pathogenic fungi, reduced root growth arrest (an R gene-mediated response) and their root-associated fungi showed lower induction of self-defence (antioxidants). Local abundance was not related to the ability to induce immune responses when pathogen recognition was bypassed by application of salicylic acid, a phytohormone that activates defence responses downstream of R gene signalling. These initial results support the hypothesis that smaller local tree populations have reduced R gene diversity and recognition-dependent immune responses, along with greater cosusceptibility to species-specific pathogens that may facilitate disease transmission and NDD. Locally rare species may be less able to increase their equilibrium abundance without genetic boosts to defence via immigration of novel R gene alleles from a larger and more diverse regional population.

  7. Investigation of urban science teachers' pedagogical engagements: Are urban science teachers culturally responsive?

    NASA Astrophysics Data System (ADS)

    Udokwu, Chukwudi John

    This study utilized mixed methodology of quantitative and qualitative research approach to explore the current pedagogical engagements of twenty middle school urban science teachers in the Midwest region of the United States. It qualitatively examined twelve of these teachers' knowledge of culturally responsive pedagogy. The study investigated the following questions: What are the current pedagogical practices of urban middle school science teachers? To what extent are middle school science teachers' pedagogical practices in urban schools culturally responsive? What are urban students' perspectives of their teachers' current pedagogical engagements? The design of the study was qualitative and quantitative methods in order to investigate these teachers' pedagogical practices. Data collections were drawn from multiple sources such as lesson plans, students' sample works, district curriculum, surveys, observational and interview notes. Analysis of collected data was a mixed methodology that involved qualitative and quantitative methods using descriptive, interpretative, pattern codes, and statistical procedures respectively. Purposeful sampling was selected for this study. Thus, demographically there were twenty participants who quantitatively took part in this study. Among them were seven (35%) males and thirteen (65%) females, three (15%) African Americans and seventeen (85%) Caucasians. In determining to what extent urban science teachers' pedagogical practices were culturally responsive, eight questions were analyzed based on four cluster themes: (a) teachers' social disposition, (b) culturally responsive curriculum, (c) classroom interactions, and (d) power pedagogy. Study result revealed that only five (25%) of the participants were engaged in culturally responsive pedagogy while fifteen (75%) were engaged in what Haberman (1991) called the pedagogy of poverty. The goal was to investigate urban science teachers' pedagogical engagements and to examine urban

  8. Investigating the functionality of an OCT4-short response element in human induced pluripotent stem cells

    PubMed Central

    Vega-Crespo, Agustin; Truong, Brian; Hermann, Kip J; Awe, Jason P; Chang, Katherine M; Lee, Patrick C; Schoenberg, Benjamen E; Wu, Lily; Byrne, James A; Lipshutz, Gerald S

    2016-01-01

    Pluripotent stem cells offer great therapeutic promise for personalized treatment platforms for numerous injuries, disorders, and diseases. Octamer-binding transcription factor 4 (OCT4) is a key regulatory gene maintaining pluripotency and self-renewal of mammalian cells. With site-specific integration for gene correction in cellular therapeutics, use of the OCT4 promoter may have advantages when expressing a suicide gene if pluripotency remains. However, the human OCT4 promoter region is 4 kb in size, limiting the capacity of therapeutic genes and other regulatory components for viral vectors, and decreasing the efficiency of homologous recombination. The purpose of this investigation was to characterize the functionality of a novel 967bp OCT4-short response element during pluripotency and to examine the OCT4 titer-dependent response during differentiation to human derivatives not expressing OCT4. Our findings demonstrate that the OCT4-short response element is active in pluripotency and this activity is in high correlation with transgene expression in vitro, and the OCT4-short response element is inactivated when pluripotent cells differentiate. These studies demonstrate that this shortened OCT4 regulatory element is functional and may be useful as part of an optimized safety component in a site-specific gene transferring system that could be used as an efficient and clinically applicable safety platform for gene transfer in cellular therapeutics. PMID:27500178

  9. An Investigation of the Dynamic Response of Spur Gear Teeth with Moving Loads

    NASA Technical Reports Server (NTRS)

    Passerello, C. E.; Shuey, L. W.

    1987-01-01

    Two concepts relating to gear dynamics were studied. The first phase of the analysis involved the study of the effect of the speed of a moving load on the dynamic deflections of a gear tooth. A single spur gear tooth modelled using finite elements was subjected to moving loads with variable velocities. The tooth tip deflection time histories were plotted, from which it was seen that the tooth tip deflection consisted of a quasistatic response with an oscillatory response superimposed on it whose amplitude was dependent on the type of load engagement. Including the rim in the analysis added flexibility to the model but did not change the general behavior of the system. The second part of the analysis involved an investigation to determine the effect on the dynamic response of the inertia of the gear tooth. A simplified analysis using meshing cantilever beams was used. In one case, the beams were assumed massless. In the other, the mass (inertia) of the beams was included. From this analysis it was found that the inertia of the tooth did not affect the dynamic response of meshing cantilever beams.

  10. Negative hemodynamic response without neuronal inhibition investigated by combining optical imaging and electrophysiological recording.

    PubMed

    Ma, Zengguang; Cao, Pengjia; Sun, Pengcheng; Lu, Zhuofan; Li, Liming; Chen, Yao; Chai, Xinyu

    2017-01-10

    Understanding the mechanisms underlying negative hemodynamic responses is critical for the interpretation of functional brain imaging signals. Negative imaging signals have been found in the visual, somatosensory and motor cortices in functional magnetic resonance imaging (fMRI) and intrinsic signal optical imaging (ISOI) studies. However, the origin of negative imaging signals is still controversial. The present study investigated the visual cortical responses to peripheral grating stimuli using multi-wavelength ISOI and electrophysiological recording. We found an increased cerebral blood volume (CBV) in the stimulus-induced regions and a decreased CBV in the adjacent regions in the visual cortex. Nevertheless, there was no significant change in blood oxygenation in the negative CBV regions. Furthermore, by combining the planar and laminar electrophysiological recordings, we did not observe significantly decreased neuronal activity in the negative CBV regions. Our results suggest that the negative hemodynamic response does not necessarily originate in decreased neuronal activity. Therefore, caution should be taken when interpreting a negative hemodynamic response as neuronal inhibition.

  11. Investigation on the forced response of a radial turbine under aerodynamic excitations

    NASA Astrophysics Data System (ADS)

    Ma, Chaochen; Huang, Zhi; Qi, Mingxu

    2016-04-01

    Rotor blades in a radial turbine with nozzle guide vanes typically experience harmonic aerodynamic excitations due to the rotor stator interaction. Dynamic stresses induced by the harmonic excitations can result in high cycle fatigue (HCF) of the blades. A reliable prediction method for forced response issue is essential to avoid the HCF problem. In this work, the forced response mechanisms were investigated based on a fluid structure interaction (FSI) method. Aerodynamic excitations were obtained by three-dimensional unsteady computational fluid dynamics (CFD) simulation with phase shifted periodic boundary conditions. The first two harmonic pressures were determined as the primary components of the excitation and applied to finite element (FE) model to conduct the computational structural dynamics (CSD) simulation. The computed results from the harmonic forced response analysis show good agreement with the predictions of Singh's advanced frequency evaluation (SAFE) diagram. Moreover, the mode superposition method used in FE simulation offers an efficient way to provide quantitative assessments of mode response levels and resonant strength.

  12. Role of law enforcement response and microbial forensics in investigation of bioterrorism.

    PubMed

    Budowle, Bruce; Beaudry, Jodi A; Barnaby, Neel G; Giusti, Alan M; Bannan, Jason D; Keim, Paul

    2007-08-01

    The risk and threat of bioterrorism and biocrime have become a large concern and challenge for governments and society to enhance biosecurity. Law enforcement plays an important role in assessing and investigating activities involved in an event of bioterrorism or biocrime. Key to a successful biosecurity program is increased awareness and early detection of threats facilitated by an integrated network of responsibilities and capabilities from government, academic, private, and public assets. To support an investigation, microbial forensic sciences are employed to analyze and characterize forensic evidence with the goal of attribution or crime scene reconstruction. Two different molecular biology-based assays--real time polymerase chain reaction (PCR) and repetitive element PCR--are described and demonstrate how molecular biology tools may be utilized to aid in the investigative process. Technologies relied on by microbial forensic scientists need to be properly validated so that the methods used are understood and so that interpretation of results is carried out within the limitations of the assays. The three types of validation are preliminary, developmental, and internal. The first is necessary for rapid response when a threat is imminent or an attack has recently occurred. The latter two apply to implementation of routinely used procedures.

  13. Role of Law Enforcement Response and Microbial Forensics in Investigation of Bioterrorism

    PubMed Central

    Budowle, Bruce; Beaudry, Jodi A.; Barnaby, Neel G.; Giusti, Alan M.; Bannan, Jason D.; Keim, Paul

    2007-01-01

    The risk and threat of bioterrorism and biocrime have become a large concern and challenge for governments and society to enhance biosecurity. Law enforcement plays an important role in assessing and investigating activities involved in an event of bioterrorism or biocrime. Key to a successful biosecurity program is increased awareness and early detection of threats facilitated by an integrated network of responsibilities and capabilities from government, academic, private, and public assets. To support an investigation, microbial forensic sciences are employed to analyze and characterize forensic evidence with the goal of attribution or crime scene reconstruction. Two different molecular biology-based assays – real time polymerase chain reaction (PCR) and repetitive element PCR – are described and demonstrate how molecular biology tools may be utilized to aid in the investigative process. Technologies relied on by microbial forensic scientists need to be properly validated so that the methods used are understood and so that interpretation of results is carried out within the limitations of the assays. The three types of validation are preliminary, developmental, and internal. The first is necessary for rapid response when a threat is imminent or an attack has recently occurred. The latter two apply to implementation of routinely used procedures. PMID:17696298

  14. Effects of chewing gum on stress and health: a replication and investigation of dose-response.

    PubMed

    Smith, Andrew

    2013-04-01

    Research suggests that chewing gum may be associated with reduced stress, depression and a reduced likelihood of having high cholesterol and blood pressure. The present study aimed to replicate these findings and extend them by examining dose-response. A web-based survey was completed by a sample of 388 workers from public sector organisations (68.5% female; mean age: 42 years, range 17-64 years). The results showed that chewing gum was associated in a linear dose-response manner with lower levels of perceived stress (both at work and life in general), anxiety and depression. Occasional gum chewers also reported a reduced risk of high cholesterol and blood pressure. Intervention studies are now required to extend these findings, and the mechanisms underlying the effects reported here need further investigation.

  15. The effects of corporate social responsibility on employees' affective commitment: a cross-cultural investigation.

    PubMed

    Mueller, Karsten; Hattrup, Kate; Spiess, Sven-Oliver; Lin-Hi, Nick

    2012-11-01

    This study investigated the moderating effects of several Global Leadership and Organizational Behavior Effectiveness (GLOBE) cultural value dimensions on the relationship between employees' perceptions of their organization's social responsibility and their affective organizational commitment. Based on data from a sample of 1,084 employees from 17 countries, results showed that perceived corporate social responsibility (CSR) was positively related to employees' affective commitment (AC), after controlling for individual job satisfaction and gender as well as for nation-level differences in unemployment rates. In addition, several GLOBE value dimensions moderated the effects of CSR on AC. In particular, perceptions of CSR were more positively related to AC in cultures higher in humane orientation, institutional collectivism, ingroup collectivism, and future orientation and in cultures lower in power distance. Implications for future CSR research and cross-cultural human resources management are discussed.

  16. Biological and chemical investigation of Allium cepa L. response to selenium inorganic compounds.

    PubMed

    Michalska-Kacymirow, M; Kurek, E; Smolis, A; Wierzbicka, M; Bulska, E

    2014-06-01

    The aim of this study was to evaluate the biological and chemical response of Allium cepa L. exposed to inorganic selenium compounds. Besides the investigation of the total content of selenium as well as its chemical speciation, the Allium test was used to evaluate the growth of onion roots and mitotic activity in the roots' meristem. The total content of selenium was determined by inductively coupled plasma mass spectrometry (ICP MS). High-performance liquid chromatography (HPLC), coupled to ICP MS, was used for the selenium chemical speciation. Results indicated that A. cepa plants are able to biotransform inorganic selenium compounds into their organic derivatives, e.g., Se-methylselenocysteine from the Se(IV) inorganic precursor. Although the differences in the biotransformation of selenium are due mainly to the oxidation state of selenium, the experiment has also shown a fine effect of counter ions (H(+), Na(+), NH4 (+)) on the response of plants and on the specific metabolism of selenium.

  17. The "Hamburger Connection" as Ecologically Unequal Exchange: A Cross-National Investigation of Beef Exports and Deforestation in Less-Developed Countries

    ERIC Educational Resources Information Center

    Austin, Kelly

    2010-01-01

    This study explores Norman Myers's concept of the "hamburger connection" as a form of ecologically unequal exchange, where more-developed nations are able to transfer the environmental costs of beef consumption to less-developed nations. I used ordinary least squares (OLS) regression to test whether deforestation in less-developed…

  18. Training rats to voluntarily dive underwater: investigations of the mammalian diving response.

    PubMed

    McCulloch, Paul F

    2014-11-12

    Underwater submergence produces autonomic changes that are observed in virtually all diving animals. This reflexly-induced response consists of apnea, a parasympathetically-induced bradycardia and a sympathetically-induced alteration of vascular resistance that maintains blood flow to the heart, brain and exercising muscles. While many of the metabolic and cardiorespiratory aspects of the diving response have been studied in marine animals, investigations of the central integrative aspects of this brainstem reflex have been relatively lacking. Because the physiology and neuroanatomy of the rat are well characterized, the rat can be used to help ascertain the central pathways of the mammalian diving response. Detailed instructions are provided on how to train rats to swim and voluntarily dive underwater through a 5 m long Plexiglas maze. Considerations regarding tank design and procedure room requirements are also given. The behavioral training is conducted in such a way as to reduce the stressfulness that could otherwise be associated with forced underwater submergence, thus minimizing activation of central stress pathways. The training procedures are not technically difficult, but they can be time-consuming. Since behavioral training of animals can only provide a model to be used with other experimental techniques, examples of how voluntarily diving rats have been used in conjunction with other physiological and neuroanatomical research techniques, and how the basic training procedures may need to be modified to accommodate these techniques, are also provided. These experiments show that voluntarily diving rats exhibit the same cardiorespiratory changes typically seen in other diving animals. The ease with which rats can be trained to voluntarily dive underwater, and the already available data from rats collected in other neurophysiological studies, makes voluntarily diving rats a good behavioral model to be used in studies investigating the central aspects of the

  19. Study of the succession of microbial communities for sulfur cycle response to ecological factors change in sediment of sewage system.

    PubMed

    Liu, Yanchen; Dong, Qian; Wu, Chen; Zhou, Xiaohong; Shi, Hanchang

    2015-06-01

    The biological reaction process of sulfur in biofilms and sediments causes serious problems of corrosion and odor in sewage systems. This study aims to reveal the distribution and shift of microbial diversity that survives inside the sediment in response to surrounding changes in sewage systems. The successions of microbial community were compared via denaturing gradient gel electrophoresis and by constructing phylogenetic trees via maximum likelihood method. The results indicated that the shift of microbial diversity is not significant along the vertical layer inside the sediment. The influences of sediment accumulation time on the shift in microbial diversity are evident, particularly with the switch of the accumulation stage. Implementing a control strategy for oxygen injection and nitrate addition evidently inhibits and stimulates some dominant sulfate-reducing bacterial strains in the sediment. The diversity in the total bacteria is positively related with ORP, dissolved oxygen, and sulfide concentration.

  20. Phenological assessment in the Owhyee Uplands: integrating climate drivers and ecological response at local to regional scales

    NASA Astrophysics Data System (ADS)

    Torregrosa, A.; Hanser, S.; Tumbusch, M. L.; Bedford, D.

    2009-12-01

    The seasonal cycle of vegetation change in biomass, structure, and composition is a dominant landscape feature influencing many ecosystem components of the Owyhee Uplands particularly resident and migratory vertebrates and invertebrates. Encompassing portions of Idaho, Nevada, and Oregon, the Owyhee Uplands have remained relatively intact with climate, exotic plant invasions, and anthropogenic agents, such as grazing, acting as the principle causes of ecosystem stress. The sagebrush habitats of the Owyhee Uplands are a stronghold for several federal and state species of special concern, including the Greater sage-grouse (Centrocercus urophasianus). We examined phenological variation in response to climate conditions such as temperature, relative humidity, precipitation, soil moisture, solar irradiance, and snowfall at a range of spatial and temporal scales across a gradient of soil and landforms. We integrated/analyzed measures of greenness derived from ground-based cameras and several satellite sensors (AVHRR, MODIS, and Landsat), early and late season field-collected measures of plant species cover and passerine bird diversity and abundance, daily measurement of soil moisture conditions from in-situ sensors, site-level snow depth conditions from thermochron fitted snow poles, and climate conditions derived from a combination of site-based meteorological stations and interpolated PRISM data. Our objectives include 1) quantifying covariation between greenness-climate-soil-snow conditions and vertebrate and plant species phenology, 2) spatial interscale comparisons of the covariation, and 3) recommendations for on-going data collection and analysis methods to explore phenological response within the context of the natural range of variability and under climate change scenarios.

  1. Acid-base physiology response to ocean acidification of two ecologically and economically important holothuroids from contrasting habitats, Holothuria scabra and Holothuria parva.

    PubMed

    Collard, Marie; Eeckhaut, Igor; Dehairs, Frank; Dubois, Philippe

    2014-12-01

    Sea cucumbers are dominant invertebrates in several ecosystems such as coral reefs, seagrass meadows and mangroves. As bioturbators, they have an important ecological role in making available calcium carbonate and nutrients to the rest of the community. However, due to their commercial value, they face overexploitation in the natural environment. On top of that, occurring ocean acidification could impact these organisms, considered sensitive as echinoderms are osmoconformers, high-magnesium calcite producers and have a low metabolism. As a first investigation of the impact of ocean acidification on sea cucumbers, we tested the impact of short-term (6 to 12 days) exposure to ocean acidification (seawater pH 7.7 and 7.4) on two sea cucumbers collected in SW Madagascar, Holothuria scabra, a high commercial value species living in the seagrass meadows, and H. parva, inhabiting the mangroves. The former lives in a habitat with moderate fluctuations of seawater chemistry (driven by day-night differences) while the second lives in a highly variable intertidal environment. In both species, pH of the coelomic fluid was significantly negatively affected by reduced seawater pH, with a pronounced extracellular acidosis in individuals maintained at pH 7.7 and 7.4. This acidosis was due to an increased dissolved inorganic carbon content and pCO2 of the coelomic fluid, indicating a limited diffusion of the CO2 towards the external medium. However, respiration and ammonium excretion rates were not affected. No evidence of accumulation of bicarbonate was observed to buffer the coelomic fluid pH. If this acidosis stays uncompensated for when facing long-term exposure, other processes could be affected in both species, eventually leading to impacts on their ecological role.

  2. Activity Book: Ocean Ecology.

    ERIC Educational Resources Information Center

    Learning, 1992

    1992-01-01

    Presents a collection of activities to help elementary students study ocean ecology. The activities have students investigate ocean inhabitants, analyze animal adaptations, examine how temperature and saltiness affect ocean creatures, and learn about safeguarding the sea. Student pages offer reproducible learning sheets. (SM)

  3. Numerical investigation of the seismo-acoustic responses of the Source Physics Experiment underground explosions

    NASA Astrophysics Data System (ADS)

    Antoun, T.; Ezzedine, S. M.; Vorobiev, O.; Glenn, L. A.

    2015-12-01

    We have performed three-dimensional high resolution simulations of underground explosions conducted recently in jointed rock outcrop as part of the Source Physics Experiment (SPE) being conducted at the Nevada National Security Site (NNSS). The main goal of the current study is to investigate the effects of the structural and geomechanical properties on the spall phenomena due to underground explosions and its subsequent effect on the seismo-acoustic signature at far distances. Two parametric studies have been undertaken to assess the impact of different 1) conceptual geological models including a single layer and two layers model, with and without joints and with and without varying geomechanical properties, and 2) depth of bursts of the explosions and explosion yields. Through these investigations we have explored not only the near-field response of the explosions but also the far-field responses of the seismic and the acoustic signatures. The near-field simulations were conducted using the Eulerian and Lagrangian codes, GEODYN and GEODYN -L, respectively, while the far-field seismic simulations were conducted using the elastic wave propagation code, WPP, and the acoustic response using the Kirchhoff-Helmholtz-Rayleigh time-dependent approximation code, KHR. Though a series of simulations, we have recorded the velocity field histories a) at the ground surface on an acoustic-source-patch for the acoustic simulations, and 2) on a seismic-source-box for the seismic simulations. We first analyzed the SPE3 and SPE4-prime experimental data and simulated results, and then simulated SPE5, SPE6/7 to anticipate their seismo-acoustic responses given conditions of uncertainties. SPE experiments were conducted in a granitic formation; we have extended the parametric study to include other geological settings such dolomite and alluvial formations. These parametric studies enabled us 1) investigating the geotechnical and geophysical key parameters that impact the seismo

  4. Investigation of Self-Help Oil-Spill Response Techniques and Equipment

    DTIC Science & Technology

    1992-05-01

    results of the research performed on bioremediation do not conclusively indicate what the proper application ratio for the bioprod- ucts should be...AD-A260 881 Report No. CG-D-21-92 1, jjr II . I’ !,lI, INVESTIGATION OF SELF-HELP OIL-SPILL RESPONSE TECHNIQUES AND EQUIPMENT Walter I. Enderlin John...Springfield, Virginia 22161 JAN 2 2 1993 -" E Prepared for: . U.S. Coast Guard Research and Development Center 1082 Shennecossett Road Groton

  5. Fermentable fiber ameliorates fermentable protein-induced changes in microbial ecology, but not the mucosal response, in the colon of piglets.

    PubMed

    Pieper, Robert; Kröger, Susan; Richter, Jan F; Wang, Jing; Martin, Lena; Bindelle, Jérôme; Htoo, John K; von Smolinski, Dorthe; Vahjen, Wilfried; Zentek, Jürgen; Van Kessel, Andrew G

    2012-04-01

    Dietary inclusion of fermentable carbohydrates (fCHO) is reported to reduce large intestinal formation of putatively toxic metabolites derived from fermentable proteins (fCP). However, the influence of diets high in fCP concentration on epithelial response and interaction with fCHO is still unclear. Thirty-two weaned piglets were fed 4 diets in a 2 × 2 factorial design with low fCP/low fCHO [14.5% crude protein (CP)/14.5% total dietary fiber (TDF)]; low fCP/high fCHO (14.8% CP/16.6% TDF); high fCP low fCHO (19.8% CP/14.5% TDF); and high fCP/high fCHO (20.1% CP/18.0% TDF) as dietary treatments. After 21-23 d, pigs were killed and colon digesta and tissue samples analyzed for indices of microbial ecology, tissue expression of genes for cell turnover, cytokines, mucus genes (MUC), and oxidative stress indices. Pig performance was unaffected by diet. fCP increased (P < 0.05) cell counts of clostridia in the Clostridium leptum group and total short and branched chain fatty acids, ammonia, putrescine, histamine, and spermidine concentrations, whereas high fCHO increased (P < 0.05) cell counts of clostridia in the C. leptum and C. coccoides groups, shifted the acetate to propionate ratio toward acetate (P < 0.05), and reduced ammonia and putrescine (P < 0.05). High dietary fCP increased (P < 0.05) expression of PCNA, IL1β, IL10, TGFβ, MUC1, MUC2, and MUC20, irrespective of fCHO concentration. The ratio of glutathione:glutathione disulfide was reduced (P < 0.05) by fCP and the expression of glutathione transferase was reduced by fCHO (P < 0.05). In conclusion, fermentable fiber ameliorates fermentable protein-induced changes in most measures of luminal microbial ecology but not the mucosal response in the large intestine of pigs.

  6. Can ecological history influence response to pollutants? Transcriptomic analysis of Manila clam collected in different Venice lagoon areas and exposed to heavy metal.

    PubMed

    Milan, Massimo; Matozzo, Valerio; Pauletto, Marianna; Di Camillo, Barbara; Giacomazzo, Matteo; Boffo, Luciano; Binato, Giovanni; Marin, Maria Gabriella; Patarnello, Tomaso; Bargelloni, Luca

    2016-05-01

    Chronic exposure to environmental pollutants can exert strong selective pressures on natural populations, favoring the transmission over generations of traits that enable individuals to survive and thrive in highly impacted environments. The lagoon of Venice is an ecosystem subject to heavy anthropogenic impact, mainly due to the industrial activities of Porto Marghera (PM), which led to a severe chemical contamination of soil, groundwater, and sediments. Gene expression analysis on wild Manila clams collected in different Venice lagoon areas enabled to identify differences in gene expression profiles between clams collected in PM and those sampled in clean areas, and the definition of molecular signatures of chemical stress. However, it remains largely unexplored to which extent modifications of gene expression patterns persists after removing the source of contamination. It is also relatively unknown whether chronic exposure to xenobiotics affects the response to other chemical pollutants. To start exploring such issues, in the present study a common-garden experiment was coupled with transcriptomic analysis, to compare gene expression profiles of PM clams with those of clams collected in the less impacted area of Chioggia (CH) during a period under the same control conditions. Part of the two experimental groups were also exposed to copper for seven days to assess whether different "ecological history" does influence response to such pollutant. The results obtained suggest that the chronic exposure to chemical pollution generated a response at the transcriptional level that persists after removal for the contaminated site. These transcriptional changes are centered on key biological processes, such as defense against either oxidative stress or tissue/protein damage, and detoxification, suggesting an adaptive strategy for surviving in the deeply impacted environment of Porto Marghera. On the other hand, CH clams appeared to respond more effectively to copper

  7. Defending Ecology.

    ERIC Educational Resources Information Center

    Margolis, Brian

    2000-01-01

    Explains how non-native species' problems in the ecosystem can introduce fundamental ecological principles in the classroom. Provides background information on damages caused by non-native species. Discusses how educators can use this environmental issue in the classroom and gives the example of zebra mussels. Lists instructional strategies for…

  8. Trash Ecology

    ERIC Educational Resources Information Center

    Lind, Georgia J.

    2004-01-01

    A hands on activity involving density, frequency and biomass using transects, quadrats and a local good deed by cleaning up the neighborhood while practicing important techniques in ecology is detailed. The activity is designed for KCC-STEP, whose primary goal is to expand the scientific knowledge and research experiences of their students, who…

  9. Investigating Undergraduate Students' Science Literacy: Responses Related to Radiation and DNA

    NASA Astrophysics Data System (ADS)

    Impey, C.; Buxner, S.; Nieberding, M.; Romine, J.

    2015-11-01

    This study is part of a larger one investigating undergraduate students' science literacy. Over the past 25 years we have been investigating undergraduate students' basic science knowledge as well as beliefs and attitudes towards science and technology. Data has been collected from almost 12,000 students, mostly freshman and sophomore students and mostly non-STEM majors. This paper presents findings of two open ended questions that probe students' understanding of radiation and DNA. Each open ended question was coded using a scheme developed from existing literature and emergent themes. Analyses revealed that STEM students are better able to correctly describe radiation and had fewer misconceptions. Many students mentioned chemical characteristics and functions of DNA although a substantial number of students reported common misconceptions or trivial responses. Our results add to our existing work to help us understand how to better support students' learning in our undergraduate courses.

  10. Automated experimentation in ecological networks

    PubMed Central

    2011-01-01

    Background In ecological networks, natural communities are studied from a complex systems perspective by representing interactions among species within them in the form of a graph, which is in turn analysed using mathematical tools. Topological features encountered in complex networks have been proved to provide the systems they represent with interesting attributes such as robustness and stability, which in ecological systems translates into the ability of communities to resist perturbations of different kinds. A focus of research in community ecology is on understanding the mechanisms by which these complex networks of interactions among species in a community arise. We employ an agent-based approach to model ecological processes operating at the species' interaction level for the study of the emergence of organisation in ecological networks. Results We have designed protocols of interaction among agents in a multi-agent system based on ecological processes occurring at the interaction level between species in plant-animal mutualistic communities. Interaction models for agents coordination thus engineered facilitate the emergence of network features such as those found in ecological networks of interacting species, in our artificial societies of agents. Conclusions Agent based models developed in this way facilitate the automation of the design an execution of simulation experiments that allow for the exploration of diverse behavioural mechanisms believed to be responsible for community organisation in ecological communities. This automated way of conducting experiments empowers the study of ecological networks by exploiting the expressive power of interaction models specification in agent systems. PMID:21554669

  11. Ecological implications of behavioural syndromes.

    PubMed

    Sih, Andrew; Cote, Julien; Evans, Mara; Fogarty, Sean; Pruitt, Jonathan

    2012-03-01

    Interspecific trait variation has long served as a conceptual foundation for our understanding of ecological patterns and dynamics. In particular, ecologists recognise the important role that animal behaviour plays in shaping ecological processes. An emerging area of interest in animal behaviour, the study of behavioural syndromes (animal personalities) considers how limited behavioural plasticity, as well as behavioural correlations affects an individual's fitness in diverse ecological contexts. In this article we explore how insights from the concept and study of behavioural syndromes provide fresh understanding of major issues in population ecology. We identify several general mechanisms for how population ecology phenomena can be influenced by a species or population's average behavioural type, by within-species variation in behavioural type, or by behavioural correlations across time or across ecological contexts. We note, in particular, the importance of behavioural type-dependent dispersal in spatial ecology. We then review recent literature and provide new syntheses for how these general mechanisms produce novel insights on five major issues in population ecology: (1) limits to species' distribution and abundance; (2) species interactions; (3) population dynamics; (4) relative responses to human-induced rapid environmental change; and (5) ecological invasions.

  12. Phytoplankton shifts in response to rapid eutrophication: palaeo-ecological evidence from a polluted coastal embayment in China

    NASA Astrophysics Data System (ADS)

    Liu, Dongyan

    2013-04-01

    A multi-proxy palaeoecological method has been used to reconstruct a 100-year time series showing coastal eutrophic processes and phytoplankton response. Total organic carbon, total nitrogen, diatom frustules, dinoflagellate cysts, brassicasterol and dinosterol were extracted from chronologic sediment cores in Sishili Bay, a polluted Chinese coastal bay. The variations of these parameters in the cores showed that eutrophic processes occurred during about 1975-1985, which corresponds to increased human activity associated with China's economic development since 1978. During the processes of eutrophication, the biomass of diatoms and dinoflagellates increased and dominant species shifted abruptly. Small heavily silicified diatoms Cyclotella stylorum and Paralia sulcata gradually took the place of the large dominant diatom Coscinodiscus radiatus, while dinoflagellates displayed a progressive increase since 1975. Compared with the changes in temperature and rainfall during 1950-2010, increased fertilizer use, marine aquaculture and sewage discharge displayed a better match to the timeline of increased trend in biomass, species shift and nutrient concentration. Altered nutrient supply ratios caused by significant increased nitrogen could play an important role on the shifts in diatom and dinoflagellate assemblages.

  13. Ecological responses of a large shallow lake (Okeechobee, Florida) to climate change and potential future hydrologic regimes.

    PubMed

    Havens, Karl E; Steinman, Alan D

    2015-04-01

    We considered how Lake Okeechobee, a large shallow lake in Florida, USA, might respond to altered hydrology associated with climate change scenarios in 2060. Water budgets and stage hydrographs were provided from the South Florida Water Management Model, a regional hydrologic model used to develop plans for Everglades restoration. Future scenarios include a 10% increase or decrease in rainfall (RF) and a calculated increase in evapotranspiration (ET), which is based on a 1.5 °C rise in temperature. Increasing RF and ET had counter-balancing effects on the water budget and when changing concurrently did not affect hydrology. In contrast, when RF decreased while ET increased, this resulted in a large change in hydrology. The surface elevation of the lake dropped by more than 2 m under this scenario compared to a future base condition, and extreme low elevation persisted for multiple years. In this declining RF/increasing ET scenario, the littoral and near-shore zones, areas that support emergent and submerged plants, were dry 55% of the time compared to less than 4% of the time in the future base run. There also were times when elevation increased as much as 3 m after intense RF events. Overall, these changes in hydrologic conditions would dramatically alter ecosystem services. Uncertainty about responses is highest at the pelagic-littoral interface, in regard to whether an extremely shallow lake could support submerged vascular plants, which are critical to the recreational fishery and for migratory birds. Along with improved regional climate modeling, research in that interface zone is needed to guide the adaptive process of Everglades restoration.

  14. Molting in Salmonella Enteritidis-challenged laying hens fed alfalfa crumbles. II. Fermentation and microbial ecology response.

    PubMed

    Dunkley, K D; McReynolds, J L; Hume, M E; Dunkley, C S; Callaway, T R; Kubena, L F; Nisbet, D J; Ricke, S C

    2007-10-01

    The objective of this study was to examine microbial population shifts and short-chain fatty acid (SCFA) responses in the gastrointestinal tract of Salmonella Enteritidis-challenged molted and nonmolted hens fed different dietary regimens. Fifteen Salmonella-free Single Comb Leghorn hens (>50 wk old) were assigned to 3 treatment groups of 5 birds each based on diet in 2 trials: 100% alfalfa crumbles (ALC), full-fed (FF, nonmolted) 100% commercial layer ration, and feed withdrawal (FW). A forced molt was induced by either a 12-d alfalfa diet or FW. In all treatment groups, each hen was challenged by crop gavage orally 4 d after molt induction with a 1-mL inoculum containing 10(6) cfu of Salmonella Enteritidis. Fecal and cecal samples (d 4, 6, 8, 11, and necropsy on d 12) were collected postchallenge. Microbial population shifts were evaluated by PCR-based 16S ribosomal RNA gene amplification and denaturing gradient gel electrophoresis, and SCFA concentrations were measured. Total SCFA in fecal and cecal contents for FW molted hens were generally lower (P < or = 0.05) in the later stages of the molt period when compared to ALC and FF treatment groups. The overall trend of SCFA in cecal and fecal samples exhibited similar patterns. In trials 1 and 2, hens molted with ALC diet generally yielded more similar amplicon band patterns with the FF hens in both fecal and cecal samples by the end of the molting period than with FW hens. The results of these studies suggest that ALC molted hens supported microflora and fermentation activities, which were more comparable to FF hens than FW hens by the end of the molting period.

  15. Behavioral response races, predator-prey shell games, ecology of fear, and patch use of pumas and their ungulate prey.

    PubMed

    Laundré, John W

    2010-10-01

    The predator-prey shell game predicts random movement of prey across the landscape, whereas the behavioral response race and landscape of fear models predict that there should be a negative relationship between the spatial distribution of a predator and its behaviorally active prey. Additionally, prey have imperfect information on the whereabouts of their predator, which the predator should incorporate in its patch use strategy. I used a one-predator-one-prey system, puma (Puma concolor)-mule deer (Odocoileus hemionus) to test the following predictions regarding predator-prey distribution and patch use by the predator. (1) Pumas will spend more time in high prey risk/low prey use habitat types, while deer will spend their time in low-risk habitats. Pumas should (2) select large forage patches more often, (3) remain in large patches longer, and (4) revisit individual large patches more often than individual smaller ones. I tested these predictions with an extensive telemetry data set collected over 16 years in a study area of patchy forested habitat. When active, pumas spent significantly less time in open areas of low intrinsic predation risk than did deer. Pumas used large patches more than expected, revisited individual large patches significantly more often than smaller ones, and stayed significantly longer in larger patches than in smaller ones. The results supported the prediction of a negative relationship in the spatial distribution of a predator and its prey and indicated that the predator is incorporating the prey's imperfect information about its presence. These results indicate a behavioral complexity on the landscape scale that can have far-reaching impacts on predator-prey interactions.

  16. Change in Tongue Morphology in Response to Expiratory Resistance Loading Investigated by Magnetic Resonance Imaging

    PubMed Central

    Yanagisawa, Yukio; Matsuo, Yoshimi; Shuntoh, Hisato; Mitamura, Masaaki; Horiuchi, Noriaki

    2013-01-01

    [Purpose] The purpose of this study was to investigate the effect of expiratory resistance load on the tongue area encompassing the suprahyoid and genioglossus muscles. [Subjects] The subjects were 30 healthy individuals (15 males, 15 females, mean age: 28.9 years). [Methods] Magnetic resonance imaging was used to investigate morphological changes in response to resistive expiratory pressure loading in the area encompassing the suprahyoid and genioglossus muscles. Images were taken when water pressure was sustained at 0%, 10%, 30%, and 50% of maximum resistive expiratory pressure. We then measured tongue area using image analysis software, and the morphological changes were analyzed using repeated measures analysis of variance followed by post hoc comparisons. [Results] A significant change in the tongue area was detected in both sexes upon loading. Multiple comparison analysis revealed further significant differences in tongue area as well as changes in tongue area in response to the different expiratory pressures. [Conclusion] The findings demonstrate that higher expiratory pressure facilitates greater reduction in tongue area. PMID:24259824

  17. Are mouse models of asthma appropriate for investigating the pathogenesis of airway hyper-responsiveness?

    PubMed Central

    Kumar, Rakesh K.; Foster, Paul S.

    2012-01-01

    Whether mouse models of chronic asthma can be used to investigate the relationship between airway inflammation/remodeling and airway hyper-responsiveness (AHR) is a vexed question. It raises issues about the extent to which such models replicate key features of the human disease. Here, we review some of the characteristic pathological features of human asthma and their relationship to AHR and examine some limitations of mouse models that are commonly used to investigate these relationships. We compare these conventional models with our mouse model of chronic asthma involving long-term low-level inhalational challenge and review studies of the relationship between inflammation/remodeling and AHR in this model and its derivatives, including models of an acute exacerbation of chronic asthma and of the induction phase of childhood asthma. We conclude that while extrapolating from studies in mouse models to AHR in humans requires cautious interpretation, such experimental work can provide significant insights into the pathogenesis of airway responsiveness and its molecular and cellular regulation. PMID:23060800

  18. Application of Spectral Ratio Methods to an Investigation of Site Response in the Los Angeles Basin

    NASA Astrophysics Data System (ADS)

    Ng, R.; Polet, J.

    2015-12-01

    It is well established that sedimentary basins can increase the amplification and duration of earthquake ground motion. Past earthquakes have shown that site effects have a major influence on seismic damage and loss in urban areas. However, the response at any given site can vary significantly, even within the LA basin. We aim to investigate site response within the LA Basin through the application of the Horizontal-to-Vertical (H/V) spectral ratio method. This method was applied to 3-component broadband waveforms from the Los Angeles Syncline Seismic Interferometry Experiment (LASSIE). LASSIE is a collaborative, temporary, and dense array of 73 broadband seismometers that were active for a two month period starting October 2014 until November 2014, transecting the Los Angeles basin from Long Beach to La Puente. We use the Geopsy software to measure the fundamental frequency and minimum site amplification at each station. Data analysis and interpretation were conducted in accordance to the Site Effects Assessment Using Ambient Excitations (SESAME) guidelines for implementing the H/V ratio technique for investigations of site effects. Results from our initial data analysis indicate an average fundamental period at the basin center of 6 s - 12 s and peaks in the spectral ratio curves at much shorter periods for sites the basin edge of. We will show maps of the amplification and fundamental frequencies based on our spectral ratio analysis of the LASSIE data and compare our results with damage patterns of historic earthquakes, as well as models of the LA basin.

  19. Investigation of self-help oil-spill response techniques and equipment

    SciTech Connect

    Enderlin, W I; Downing, J P; Enderlin, C W; Sanquist, T F; Pope, W S

    1992-06-01

    The US Coast Guard commissioned Pacific Northwest Laboratory (PNL) to conduct this study of 45 self-help oil-spill response techniques and equipment for oceangoing tankers and inland tank barges to assess the potential effectiveness of the proposed countermeasure categories. This study considers the hypothetical outflow of oil in the case of side damage and bottom damage to single-hull designs. The results will be considered by the Coast Guard in drafting regulations pertaining to the requirement for tanker vessels to carry oil pollution response equipment (i.e., in response to the oil Pollution Act of 1990). PNL's approach to this investigation included: assessing time-dependent oil outflow in the cases of collision and grounding of both tankers and barges; identifying environmental constraints on self-help countermeasure operation; identifying human factor issues, such as crew performance, safety, and training requirements for the self-help countermeasures considered; and assessing each self-help countermeasure with respect to its potential for minimizing oil loss to the environment. Results from the time-dependent oil outflow, environmental limitations, and human factors requirements were input into a simulation model.

  20. Investigating flight response of Pacific brant to helicopters at Izembek Lagoon, Alaska by using logistic regression

    USGS Publications Warehouse

    Erickson, Wallace P.; Nick, Todd G.; Ward, David H.; Peck, Roxy; Haugh, Larry D.; Goodman, Arnold

    1998-01-01

    Izembek Lagoon, an estuary in Alaska, is a very important staging area for Pacific brant, a small migratory goose. Each fall, nearly the entire Pacific Flyway population of 130,000 brant flies to Izembek Lagoon and feeds on eelgrass to accumulate fat reserves for nonstop transoceanic migration to wintering areas as distant as Mexico. In the past 10 years, offshore drilling activities in this area have increased, and, as a result, the air traffic in and out of the nearby Cold Bay airport has also increased. There has been a concern that this increased air traffic could affect the brant by disturbing them from their feeding and resting activities, which in turn could result in reduced energy intake and buildup. This may increase the mortality rates during their migratory journey. Because of these concerns, a study was conducted to investigate the flight response of brant to overflights of large helicopters. Response was measured on flocks during experimental overflights of large helicopters flown at varying altitudes and lateral (perpendicular) distances from the flocks. Logistic regression models were developed for predicting probability of flight response as a function of these distance variables. Results of this study may be used in the development of new FAA guidelines for aircraft near Izembek Lagoon.

  1. A numerical and experimental investigation of premixed methane-air flame transient response

    SciTech Connect

    Habib N. Najm; Phillip H. Paul; Omar M. Knio; Andrew McIlroy

    2000-01-06

    The authors report the results of a numerical and experimental investigation of the response of premixed methane-air flames to transient strain-rate disturbances induced by a two-dimensional counter-rotating vortex-pair. The numerical and experimental time histories of flow and flame evolution are matched over a 10 ms interaction time. Measurements and computations of CH and OH peak data evolution are reported, and found to indicate mis-prediction of the flame time scales in the numerical model. Qualitative transient features of OH at rich conditions are not predicted in the computations. On the other hand, evolution of computed and measured normalized HCO fractions are in agreement. The computed CH{sub 3}O response exhibits a strong transient driven by changes to internal flame structure, namely temperature profile steepening, induced by the flow field. Steady state experimental PLIF CH{sub 3}O data is reported, but experimental transient CH{sub 3}O data is not available. The present analysis indicates that the flame responds at time scales that are quite distinct from ``propagation'' time scale derived from flame thickness and burning speed. Evidently, these propagation time scales are not adequate for characterizing the transient flame response.

  2. Investigation of auditory processing disorder and language impairment using the speech-evoked auditory brainstem response.

    PubMed

    Rocha-Muniz, Caroline N; Befi-Lopes, Debora M; Schochat, Eliane

    2012-12-01

    This study investigated whether there are differences in the Speech-Evoked Auditory Brainstem Response among children with Typical Development (TD), (Central) Auditory Processing Disorder (C)APD, and Language Impairment (LI). The speech-evoked Auditory Brainstem Response was tested in 57 children (ages 6-12). The children were placed into three groups: TD (n = 18), (C)APD (n = 18) and LI (n = 21). Speech-evoked ABR were elicited using the five-formant syllable/da/. Three dimensions were defined for analysis, including timing, harmonics, and pitch. A comparative analysis of the responses between the typical development children and children with (C)APD and LI revealed abnormal encoding of the speech acoustic features that are characteristics of speech perception in children with (C)APD and LI, although the two groups differed in their abnormalities. While the children with (C)APD might had a greater difficulty distinguishing stimuli based on timing cues, the children with LI had the additional difficulty of distinguishing speech harmonics, which are important to the identification of speech sounds. These data suggested that an inefficient representation of crucial components of speech sounds may contribute to the difficulties with language processing found in children with LI. Furthermore, these findings may indicate that the neural processes mediated by the auditory brainstem differ among children with auditory processing and speech-language disorders.

  3. Proteomic investigation of male Gammarus fossarum, a freshwater crustacean, in response to endocrine disruptors.

    PubMed

    Trapp, Judith; Armengaud, Jean; Pible, Olivier; Gaillard, Jean-Charles; Abbaci, Khedidja; Habtoul, Yassine; Chaumot, Arnaud; Geffard, Olivier

    2015-01-02

    While the decrease in human sperm count in response to pollutants is a worldwide concern, little attention is being devoted to its causes and occurrence in the biodiversity of the animal kingdom. Arthropoda is the most species-rich phyla, inhabiting all aquatic and terrestrial ecosystems. During evolution, key molecular players of the arthropod endocrine system have diverged from the vertebrate counterparts. Consequently, arthropods may have different sensitivities toward endocrine disrupting chemicals (EDCs). Here alteration of sperm quality in a crustacean, Gammarus fossarum, a popular organism in freshwater risk assessment, was investigated after laboratory exposure to various concentrations of three different xenobiotics: cadmium, methoxyfenozide, and pyriproxyfen. The integrity of the reproductive process was assessed by means of sperm-quality markers. For each substance, semiquantitative/relative proteomics based on spectral counting procedure was carried out on male gonads to observe the biological impact. The changes in a total of 871 proteins were monitored in response to toxic pressure. A drastic effect was observed on spermatozoon production, with a dose-response relationship. While exposure to EDCs leads to strong modulations of male-specific proteins in testis, no induction of female-specific proteins was noted. Also, a significant portion of orphans proved to be sensitive to toxic stress.

  4. An fMRI investigation of responses to peer rejection in adolescents with autism spectrum disorders.

    PubMed

    Masten, Carrie L; Colich, Natalie L; Rudie, Jeffrey D; Bookheimer, Susan Y; Eisenberger, Naomi I; Dapretto, Mirella

    2011-07-01

    Peer rejection is particularly pervasive among adolescents with autism spectrum disorders (ASD). However, how adolescents with ASD differ from typically developing adolescents in their responses to peer rejection is poorly understood. The goal of the current investigation was to examine neural responses to peer exclusion among adolescents with ASD compared to typically developing adolescents. Nineteen adolescents with ASD and 17 typically developing controls underwent fMRI as they were ostensibly excluded by peers during an online game called Cyberball. Afterwards, participants reported their distress about the exclusion. Compared to typically developing adolescents, those with ASD displayed less activity in regions previously linked with the distressing aspect of peer exclusion, including the subgenual anterior cingulate and anterior insula, as well as less activity in regions previously linked with the regulation of distress responses during peer exclusion, including the ventrolateral prefrontal cortex and ventral striatum. Interestingly, however, both groups self-reported equivalent levels of distress. This suggests that adolescents with ASD may engage in differential processing of social experiences at the neural level, but be equally aware of, and concerned about, peer rejection. Overall, these findings contribute new insights about how this population may differentially experience negative social events in their daily lives.

  5. Physiological and Proteomic Investigations to Study the Response of Tomato Graft Unions under Temperature Stress

    PubMed Central

    Muneer, Sowbiya; Ko, Chung Ho; Wei, Hao; Chen, Yuze; Jeong, Byoung Ryong

    2016-01-01

    Background Grafting is an established practice for asexual propagation in horticultural and agricultural crops. The study on graft unions has become of interest for horticulturists using proteomic and genomic techniques to observe transfer of genetic material and signal transduction pathways from root to shoot and shoot to root. Another reason to study the graft unions was potentially to observe resistance against abiotic stresses. Using physiological and proteomic analyses, we investigated graft unions (rootstock and scions) of tomato genotypes exposed to standard-normal (23/23 and 25/18°C day/night) and high-low temperatures (30/15°C day/night). Results Graft unions had varied responses to the diverse temperatures. High-low temperature, but not standard-normal temperature, induced the production of reactive oxygen species (ROS) in the form of H2O2 and O2-1 in rootstock and scions. However, the expression of many cell protection molecules was also induced, including antioxidant enzymes and their immunoblots, which also show an increase in their activities such as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). The graft interfaces thus actively defend against stress by modifying their physiological and proteomic responses to establish a new cellular homeostasis. As a result, many proteins for cellular defense were regulated in graft unions under diverse temperature, in addition to the regulation of photosynthetic proteins, ion binding/transport proteins, and protein synthesis. Moreover, biomass, hardness, and vascular transport activity were evaluated to investigate the basic connectivity between rootstock and scions. Conclusions Our study provides physiological evidence of the grafted plants’ response to diverse temperature. Most notably, our study provides novel insight into the mechanisms used to adapt the diverse temperature in graft unions (rootstock/scion). PMID:27310261

  6. Seismic response of rock slopes: Numerical investigations on the role of internal structure

    NASA Astrophysics Data System (ADS)

    Arnold, L.; Applegate, K.; Gibson, M.; Wartman, J.; Adams, S.; Maclaughlin, M.; Smith, S.; Keefer, D. K.

    2013-12-01

    The stability of rock slopes is significantly influenced and often controlled by the internal structure of the slope created by such discontinuities as joints, shear zones, and faults. Under seismic conditions, these discontinuities influence both the resistance of a slope to failure and its response to dynamic loading. The dynamic response, which can be characterized by the slope's natural frequency and amplification of ground motion, governs the loading experienced by the slope in a seismic event and, therefore, influences the slope's stability. In support of the Network for Earthquake Engineering Simulation (NEES) project Seismically-Induced Rock Slope Failure: Mechanisms and Prediction (NEESROCK), we conducted a 2D numerical investigation using the discrete element method (DEM) coupled with simple discrete fracture networks (DFNs). The intact rock mass is simulated with a bonded assembly of discrete particles, commonly referred to as the bonded-particle model (BPM) for rock. Discontinuities in the BPM are formed by the insertion of smooth, unbonded contacts along specified planes. The influence of discontinuity spacing, orientation, and stiffness on slope natural frequency and amplification was investigated with the commercially available Particle Flow Code (PFC2D). Numerical results indicate that increased discontinuity spacing has a non-linear effect in decreasing the amplification and increasing the natural frequency of the slope. As discontinuity dip changes from sub-horizontal to sub-vertical, the slope's level of amplification increases while the natural frequency of the slope decreases. Increased joint stiffness decreases amplification and increases natural frequency. The results reveal that internal structure has a strong influence on rock slope dynamics that can significantly change the system's dynamic response and stability during seismic loading. Financial support for this research was provided by the United States National Science Foundation (NSF

  7. Pore-scale investigation on the response of heterotrophic respiration to moisture conditions in heterogeneous soils

    SciTech Connect

    Yan, Zhifeng; Liu, Chongxuan; Todd-Brown, Katherine E.; Liu, Yuanyuan; Bond-Lamberty, Ben; Bailey, Vanessa L.

    2016-11-15

    The relationship between microbial respiration rate and soil moisture content is an important property for understanding and predicting soil organic carbon degradation, CO2 production and emission, and their subsequent effects on climate change. This paper reports a pore-scale modeling study to investigate the response of heterotrophic respiration to moisture conditions in soils and to evaluate various factors that affect this response. X-ray computed tomography was used to derive soil pore structures, which were then used for pore-scale model investigation. The pore-scale results were then averaged to calculate the effective respiration rates as a function of water content in soils. The calculated effective respiration rate first increases and then decreases with increasing soil water content, showing a maximum respiration rate at water saturation degree of 0.75 that is consistent with field and laboratory observations. The relationship between the respiration rate and moisture content is affected by various factors, including pore-scale organic carbon bioavailability, the rate of oxygen delivery, soil pore structure and physical heterogeneity, soil clay content, and microbial drought resistivity. Simulations also illustrates that a larger fraction of CO2 produced from microbial respiration can be accumulated inside soil cores under higher saturation conditions, implying that CO2 flux measured on the top of soil cores may underestimate or overestimate true soil respiration rates under dynamic moisture conditions. Overall, this study provides mechanistic insights into the soil respiration response to the change in moisture conditions, and reveals a complex relationship between heterotrophic microbial respiration rate and moisture content in soils that is affected by various hydrological, geochemical, and biophysical factors.

  8. The historical ecology of Namibian rangelands: vegetation change since 1876 in response to local and global drivers.

    PubMed

    Rohde, Richard F; Hoffman, M Timm

    2012-02-01

    The influence of both local and global drivers on long-term changes in the vegetation of Namibia's extensive rangelands was investigated. Fifty-two historical photographs of the Palgrave Expedition of 1876 were re-photographed and used to document changes over more than 130 years, in grass, shrub and tree cover within three major biomes along a 1200km climatic gradient in central and southern Namibia. We showed that patterns of change are correlated with mean annual precipitation (MAP) and that below a threshold of around 250mm, vegetation has remained remarkably stable regardless of land-use or tenure regime. Above this threshold, an increase in tree cover is linked to the rainfall gradient, the legacies of historical events in the late 19th century, subsequent transformations in land-use and increased atmospheric CO(2). We discuss these findings in relation to pastoral and settler societies, paleo- and historical climatic trends and predictions of vegetation change under future global warming scenarios. We argue that changes in land-use associated with colonialism (decimation of megaherbivores and wildlife browsers; fire suppression, cattle ranching), as well as the effects of CO(2) fertilisation provide the most parsimonious explanations for vegetation change. We found no evidence that aridification, as projected under future climate change scenarios, has started in the region. This study provided empirical evidence and theoretical insights into the relative importance of local and global drivers of change in the savanna environments of central and southern Namibia and global savanna ecosystems more generally.

  9. Metal-Polycyclic Aromatic Hydrocarbon Mixture Toxicity in Hyalella azteca. 1. Response Surfaces and Isoboles To Measure Non-additive Mixture Toxicity and Ecological Risk.

    PubMed

    Gauthier, Patrick T; Norwood, Warren P; Prepas, Ellie E; Pyle, Greg G

    2015-10-06

    Mixtures of metals and polycyclic aromatic hydrocarbons (PAHs) occur ubiquitously in aquatic environments, yet relatively little is known regarding their potential to produce non-additive toxicity (i.e., antagonism or potentiation). A review of the lethality of metal-PAH mixtures in aquatic biota revealed that more-than-additive lethality is as common as strictly additive effects. Approaches to ecological risk assessment do not consider non-additive toxicity of metal-PAH mixtures. Forty-eight-hour water-only binary mixture toxicity experiments were conducted to determine the additive toxic nature of mixtures of Cu, Cd, V, or Ni with phenanthrene (PHE) or phenanthrenequinone (PHQ) using the aquatic amphipod Hyalella azteca. In cases where more-than-additive toxicity was observed, we calculated the possible mortality rates at Canada's environmental water quality guideline concentrations. We used a three-dimensional response surface isobole model-based approach to compare the observed co-toxicity in juvenile amphipods to predicted outcomes based on concentration addition or effects addition mixtures models. More-than-additive lethality was observed for all Cu-PHE, Cu-PHQ, and several Cd-PHE, Cd-PHQ, and Ni-PHE mixtures. Our analysis predicts Cu-PHE, Cu-PHQ, Cd-PHE, and Cd-PHQ mixtures at the Canadian Water Quality Guideline concentrations would produce 7.5%, 3.7%, 4.4% and 1.4% mortality, respectively.

  10. Investigating the autonomic nervous system response to anxiety in children with autism spectrum disorders.

    PubMed

    Kushki, Azadeh; Drumm, Ellen; Pla Mobarak, Michele; Tanel, Nadia; Dupuis, Annie; Chau, Tom; Anagnostou, Evdokia

    2013-01-01

    Assessment of anxiety symptoms in autism spectrum disorders (ASD) is a challenging task due to the symptom overlap between the two conditions as well as the difficulties in communication and awareness of emotions in ASD. This motivates the development of a physiological marker of anxiety in ASD that is independent of language and does not require observation of overt behaviour. In this study, we investigated the feasibility of using indicators of autonomic nervous system (ANS) activity for this purpose. Specially, the objectives of the study were to 1) examine whether or not anxiety causes significant measurable changes in indicators of ANS in an ASD population, and 2) characterize the pattern of these changes in ASD. We measured three physiological indicators of the autonomic nervous system response (heart rate, electrodermal activity, and skin temperature) during a baseline (movie watching) and anxiety condition (Stroop task) in a sample of typically developing children (n = 17) and children with ASD (n = 12). The anxiety condition caused significant changes in heart rate and electrodermal activity in both groups, however, a differential pattern of response was found between the two groups. In particular, the ASD group showed elevated heart rate during both baseline and anxiety conditions. Elevated and blunted phasic electrodermal activity were found in the ASD group during baseline and anxiety conditions, respectively. Finally, the ASD group did not show the typical decrease in skin temperature in response to anxiety. These results suggest that 1) signals of the autonomic nervous system may be used as indicators of anxiety in children with ASD, and 2) ASD may be associated with an atypical autonomic response to anxiety that is most consistent with sympathetic over-arousal and parasympathetic under-arousal.

  11. Investigating the Autonomic Nervous System Response to Anxiety in Children with Autism Spectrum Disorders

    PubMed Central

    Kushki, Azadeh; Drumm, Ellen; Pla Mobarak, Michele; Tanel, Nadia; Dupuis, Annie; Chau, Tom; Anagnostou, Evdokia

    2013-01-01

    Assessment of anxiety symptoms in autism spectrum disorders (ASD) is a challenging task due to the symptom overlap between the two conditions as well as the difficulties in communication and awareness of emotions in ASD. This motivates the development of a physiological marker of anxiety in ASD that is independent of language and does not require observation of overt behaviour. In this study, we investigated the feasibility of using indicators of autonomic nervous system (ANS) activity for this purpose. Specially, the objectives of the study were to 1) examine whether or not anxiety causes significant measurable changes in indicators of ANS in an ASD population, and 2) characterize the pattern of these changes in ASD. We measured three physiological indicators of the autonomic nervous system response (heart rate, electrodermal activity, and skin temperature) during a baseline (movie watching) and anxiety condition (Stroop task) in a sample of typically developing children (n = 17) and children with ASD (n = 12). The anxiety condition caused significant changes in heart rate and electrodermal activity in both groups, however, a differential pattern of response was found between the two groups. In particular, the ASD group showed elevated heart rate during both baseline and anxiety conditions. Elevated and blunted phasic electrodermal activity were found in the ASD group during baseline and anxiety conditions, respectively. Finally, the ASD group did not show the typical decrease in skin temperature in response to anxiety. These results suggest that 1) signals of the autonomic nervous system may be used as indicators of anxiety in children with ASD, and 2) ASD may be associated with an atypical autonomic response to anxiety that is most consistent with sympathetic over-arousal and parasympathetic under-arousal. PMID:23577072

  12. Preliminary investigation into the design of thermally responsive Forster resonance energy transfer colloids

    NASA Astrophysics Data System (ADS)

    Bedford, Monte Scott

    While nuclear imaging techniques (Magnetic Resonance Imaging, Computed Tomography, and Positron Emission Tomography) have proven effective for diagnosis and treatment of disease in the human body, fluorescence-enhanced optical imaging offers additional benefits. Fluorescent imaging provides high resolution with real-time response, persistent lifetime (hours to days), cell targeting, and transdermal penetration with minimal physical encumbrance. Malignant cells can be targeted by absorbance of exogenous fluorescent nanoprobe contrast agents. Imaging is improved by fluorescent enhancement, especially by energy transfer between attached dyes. Also for use against cancer are heat-active treatments, such as hyperthermal, photothermal, and chemothermal therapies. Helpful to these treatments is the thermal response from nanoprobes, within human cells, which provide real-time feedback. The present study investigates the design and feasibility of a nanoprobe molecular device, absorbable into malignant human cells, which provides real-time tracking and thermal response, as indicated by enhanced fluorescence by energy transfer. A poly(propargyl acrylate) colloidal suspension was synthesized. The particles were modified with a triblock copolymer, previously shown to be thermally responsive, and an end-attached fluorescent dye. A second dye was modeled for attachment in subsequent work. When two fluorescent dyes are brought within sufficiently close proximity, and excitation light is supplied, energy can be transferred between dyes to give enhanced fluorescence with a large Stokes shift (increase in wavelength between excitation and emission). The dye pair was modeled for overlap of emission and absorbance wavelengths, and energy transfer was demonstrated with 23% efficiency and a 209 nm Stokes shift. The quantum yield of the donor dye was determined at 70%, and the distance for 50% energy transfer was calculated at 2.9 nm, consistent with reports for similar compounds. When

  13. On the slow decompressive response of volatile- and crystal-bearing magmas: An analogue experimental investigation

    NASA Astrophysics Data System (ADS)

    Spina, Laura; Cimarelli, Corrado; Scheu, Bettina; Di Genova, Danilo; Dingwell, Donald B.

    2016-01-01

    The degassing kinetics of ascending magma strongly affect eruption dynamics. The kinetics are in turn influenced by magma properties. The investigation of the relationship between magma properties and eruption dynamics is a key element in revealing the processes characterizing magmatic flows within the shallow conduit. To explore the effects of physical properties on degassing in basaltic eruptive systems, we have designed and carried out experiments on the slow decompressive response of analogue magmas, composed of silicone-oil-based suspensions, using a shock-tube apparatus. Four series of experiments were performed: 1) particle-free silicone oils with viscosity ranging from 1 to 1000 Pa s were used to constrain the liquid response; 2) silicone oils with variable proportion of suspended micrometric spherical particles were employed to assess the effect of different crystal fractions; 3) suspensions of elongated particles in silicone oils were used to investigate the role of crystal shape; 4) the effects of saturation time and pressure were examined. The rheology of both spherical- and elongated-particle-bearing suspensions were characterized by concentric cylinder rotational rheometry. The flow dynamics of the bubbly fluid, from the process of bubble nucleation up to the development of a permeable bubble network, were constrained using image analysis. Different fluid regimes were distinguished: (i) nucleation, (ii) foam build-up and (iii) foam oscillation. By comparing results obtained from the different series of experiments, we were able to assess the primary role played by the presence of particles on the evolution of the gas volume fraction within the samples. Particle fraction has a dominant role at high concentration, affecting the motion of the fluid. Finally, particle shape influences the long-term degassing efficiency of the fluid. Using scaling considerations, such observations are applied to mafic to intermediate systems. The results of our

  14. Geological Investigation and analysis in response to Earthquake Induced Landslide in West Sumatra

    NASA Astrophysics Data System (ADS)

    Karnawati, D.; Wilopo, W.; Salahudin, S.; Sudarno, I.; Burton, P.

    2009-12-01

    Substantial socio-economical loss occurred in response to the September 30. 2009 West Sumatra Earthquake with magnitude of 7.6. Damage of houses and engineered structures mostly occurred at the low land of alluvium sediments due to the ground amplification, whilst at the high land of mountain slopes several villages were buried by massive debris of rocks and soils. It was recorded that 1115 people died due to this disasters. Series of geological investigation was carried out by Geological Engineering Department of Gadjah Mada University, with the purpose to support the rehabilitation program. Based on this preliminary investigation it was identified that most of the house and engineered structural damages at the alluvial deposits mainly due to by the poor quality of such houses and engineered structures, which poorly resist the ground amplification, instead of due to the control of geological conditions. On the other hand, the existence and distribution of structural geology (faults and joints) at the mountaineous regions are significant in controlling the distribution of landslides, with the types of rock falls, debris flows and debris falls. Despite the landslide susceptibility mapping conducted by Geological Survey of Indonesia, more detailed investigation is required to be carried out in the region surrounding Maninjau Lake, in order to provide safer places for village relocation. Accordingly Gadjah Mada University in collaboration with the local university (Andalas University) as well as with the local Government of Agam Regency and the Geological Survey of Indonesia, serve the mission for conducting rather more detailed geological and landslide investigation. It is also crucial that the investigation (survey and mapping) on the social perception and expectation of local people living in this landslide susceptible area should also be carried out, to support the mitigation effort of any future potential earthquake induced landslides.

  15. Estimating the Influence of a Tributary on Primary Productivity in Delaware Bay from Continuous Data: Biogeochemical and Ecological Responses to Inputs from the Murderkill

    NASA Astrophysics Data System (ADS)

    Voynova, Y. G.; Lebaron, K. C.; Barnes, R. T.; Ullman, W. J.

    2014-12-01

    Since April 2012, the University of Delaware has operated a real-time water quality monitoring station at Bowers, DE, to determine the effect of nutrient loads from the Murderkill Estuary to the Delaware Bay. The Land Ocean Biogeochemical Observatory (LOBO; Hach/Sea-Bird Electronics) is deployed under a public dock, with support from the Kent County Board of Public Works and Delaware's Department of Natural Resources and Environmental Control, and in collaboration with the USGS that operates a gauging station at the same site (01484085). Every hour the LOBO measures salinity, temperature, pressure, dissolved oxygen, turbidity, chlorophyll, CDOM, nitrate (NO3-) and orthophosphate (PO43-). Ebb tide measurements reflect conditions in the Estuary and flood tide measurements reflect conditions in Delaware Bay. Real-time data are available to the public at kentcounty.loboviz.com. Using hourly data from the LOBO, we are able to assess the nutrient and particle exchange between the Murderkill and the Delaware Bay, as well as biogeochemical and ecological responses to this exchange. Primary production in the turbid Estuary is low and nutrients from the Murderkill are efficiently delivered to Delaware Bay, where O2 production response to nitrate influx is almost instantaneous. In the summer, during the day, nutrients originating in the Estuary (ebb tide NO3- > 50-60 μM) stimulate phytoplankton growth in Delaware Bay, indicated by chlorophyll increases and O2 supersaturation during flood tide. This suggests that the Murderkill and other similar tributaries are important nutrient sources to the Delaware Bay. We use a phase-sensitive analysis to extract data characterizing the Delaware Bay, and then use dissolved oxygen to calculate rates of primary production and respiration. Newly produced Delaware Bay phytoplankton (often > 40 µg Chla L-1) may be an important labile carbon source supporting respiration in the Estuary and its surrounding salt marshes.

  16. Light and desiccation responses of some Hymenophyllaceae (filmy ferns) from Trinidad, Venezuela and New Zealand: poikilohydry in a light-limited but low evaporation ecological niche

    PubMed Central

    Proctor, Michael C. F.

    2012-01-01

    Background and Aims Hymenophyllaceae (filmy ferns) are typically plants of shady, constantly moist habitats. They attain greatest species diversity and biomass in humid tropical montane forests and temperate hyperoceanic climates. This paper presents ecophysiological data bearing on their worldwide ecological niche space and its limits. Methods Chlorophyll fluorescence was used to monitor recovery in desiccation experiments, and for measurements of 95 % saturating irradiance [photosynthetic photon flux density (PPFD95 %)] of photosynthetic electron flow and other parameters, in the New Zealand Hymenophyllum sanguinolentum, and three species each of Hymenophyllum and Trichomanes from forests in Trinidad and Venezuela. Key Results Hymenophyllum sanguinolentum was comparable in desiccation tolerance and light responses with the European species. The more common species in the two tropical forests showed PPFD95 % >100 µmol m−2 s−1, and withstood moderate desiccation (–40 MPa) for several days. The four most shade-adapted species had PPFD95 % ≤51 µmol m−2 s−1, and were sensitive to even mild and brief desiccation (–22 MPa for 3 d). Conclusions Light and desiccation responses of filmy ferns can be seen as an integrated package. At low light and windspeed in humid forests, net radiation and saturation deficit are low, and diffusion resistance high. Water loss is slow and can be supported by modest conduction from the sub-stratum. With higher irradiance, selection pressure for desiccation tolerance increases progressively. With low light and high humidity, the filmy fern pattern of adaptation is probably optimal, and the vascular plant leaf with mesophyll and stomata offers no advantage in light capture, water economy or CO2 uptake. Trade-offs between light adaptation and desiccation tolerance, and between stem conduction and water absorption through the leaf surface, underlie adaptive radiation and niche differentiation of species within the family

  17. Biochemical responses of ecological importance in males of the austral South America amphipod Hyalella curvispina Shoemaker, 1942 exposed to waterborne cadmium and copper.

    PubMed

    Giusto, Anabella; Ferrari, Lucrecia

    2014-02-01

    The use of physiological parameters as sensitive indicators of toxic stress from exposure to different pollutants is an important issue to be studied. Hyalella curvispina is a Neotropical amphipod often used in ecotoxicological evaluations. This work aimed to quantify biochemical responses of ecological importance in H. curvispina males under stress exposure to sublethal concentrations of waterborne copper (Cu) and cadmium (Cd); in order to obtain basic physiological data as indicators of early effect on this species, on track to its standardization. In order to evaluate the physiological, biochemical and energetic status of the exposed animals, the following endpoints were selected: content of glycogen, total proteins, total lipids, triglycerides, glycerol, arginine, arginine phosphate, levels of lipid peroxidation (TBARS), and Na(+)/K(+)ATPase, catalase (CAT) and superoxide dismutase (SOD) activities. Our results show that the concentrations of Cu (135 and 175 µg/L) and Cd (6.5 and 10.5 µg/L) tested altered most of the biochemical variables measured (glycogen, total proteins, total lipids, triglycerides, arginine phosphate, TBARS, and SOD and Na(+)/K(+)ATPase activities). In addition, neither the levels of glycerol and arginine nor CAT activity were affected by exposure to either metal. Energy metabolism was similarly affected both by exposure to Cu and exposure to Cd. The results obtained show the existence of an energy imbalance associated with oxidative damage, suggesting a comprehensive response. This work represents a first contribution of the evaluation of the effect of two heavy metals in some parameters of oxidative stress and energy metabolism of H. curvispina males. The results indicate these parameters can provide a sensitive criterion for the assessment of early ecotoxicological effects of Cu and Cd in laboratory assays, on a native species representative of the zoobenthic and epiphytic communities of South America.

  18. Investigation of the energy response of EBT-2 GAFCHROMIC(TM) film model

    NASA Astrophysics Data System (ADS)

    Singh, Khushdeep

    The aim of this project is to quantify the energy response of the existing EBT-2 model GAFCHROMIC™ film and investigate for the eventual possible chemical compositions with improved energy response. In this work, the overall energy dependence of the EBT-2 model GAFCHROMIC™ film is quantized through intrinsic and absorbed dose energy response. Absorbed dose energy response is studied by calculating dose to film sensitive layer and dose to water using DOSRZnrc of EGSnrcMP Monte Carlo user-code. The film was simulated inside a large body of solid water for megavoltage beams, while at kilovoltage energies the film was modeled in air. The simulations were repeated to score the dose to water for megavoltage and air kerma for kilo-voltage beams, respectively. The intrinsic energy response is quantified through a measurement of total energy response divided by the Monte Carlo calculated absorbed dose energy response. The measurements consisted of delivering an exact dose of 2 Gy to the sensitive layer of the film at orthovoltage energies (50 kVp, 120 kVp, and 180 kVp), 192Ir and 60Co beam. AAPM TG-51 and TG-61 reports were used to determine the dose-to-water and air-kerma in air in megavoltage and orthovoltage beams, respectively, while Monte Carlo simulated corrections were used to convert these results to the desired dose to the sensitive layer of the film. For EBT-2 model GAFCHROMIC™ film, the overall energy dependence was found to vary by 39 % in the effective energy range from 24 keV to 1.25 MeV (for 60Co beam). It was determined that intrinsic (LET-dependent) energy dependence also plays an important role in the total energy dependence of EBT-2 model GAFCHROMIC™ film and cannot be ignored. The absorbed dose energy dependence was also studied for a wide variety of film active layer compositions in a 10 keV-100 keV energy range as well as at 60Co using Monte Carlo simulations. The composition of the film active layer was varied according to physical limits set

  19. Mitonuclear Ecology

    PubMed Central

    Hill, Geoffrey E.

    2015-01-01

    Eukaryotes were born of a chimeric union between two prokaryotes—the progenitors of the mitochondrial and nuclear genomes. Early in eukaryote evolution, most mitochondrial genes were lost or transferred to the nucleus, but a core set of genes that code exclusively for products associated with the electron transport system remained in the mitochondrion. The products of these mitochondrial genes work in intimate association with the products of nuclear genes to enable oxidative phosphorylation and core energy production. The need for coadaptation, the challenge of cotransmission, and the possibility of genomic conflict between mitochondrial and nuclear genes have profound consequences for the ecology and evolution of eukaryotic life. An emerging interdisciplinary field that I call “mitonuclear ecology” is reassessing core concepts in evolutionary ecology including sexual reproduction, two sexes, sexual selection, adaptation, and speciation in light of the interactions of mitochondrial and nuclear genomes. PMID:25931514

  20. Investigation of the Leak Response of a Carbon-Fiber Laminate Loaded in Biaxial Tension

    NASA Technical Reports Server (NTRS)

    Jackson, Wade C.; Ratcliffe, James G.

    2013-01-01

    Designers of pressurized structures have been reluctant to use composite materials because of concerns over leakage. Biaxial stress states are expected to be the worst-case loading condition for allowing leakage to occur through microcracks. To investigate the leakage behavior under in-plane biaxial loading, a cruciform composite specimen was designed that would have a relatively large test section with a uniform 1:1 biaxial loading ratio. A 7.6-cm-square test section was desired for future investigations of the leakage response as a result of impact damage. Many iterations of the cruciform specimen were evaluated using finite element analysis to reduce stress concentrations and maximize the size of the uniform biaxial strain field. The final design allowed the specimen to go to relatively high biaxial strain levels without incurring damage away from the test section. The specimen was designed and manufactured using carbon/epoxy fabric with a four-ply-thick, quasi-isotropic, central test section. Initial validation and testing were performed on a specimen without impact damage. The specimen was tested to maximum biaxial strains of approximately 4500micro epsilon without apparent damage. A leak measurement system containing a pressurized cavity was clamped to the test section and used to measure the flow rate through the specimen. The leakage behavior of the specimen was investigated for pressure differences up to 172 kPa

  1. Heading in football. Part 1: Development of biomechanical methods to investigate head response

    PubMed Central

    Shewchenko, N; Withnall, C; Keown, M; Gittens, R; Dvorak, J

    2005-01-01

    Objectives: There has been growing controversy regarding long term effects of repeated low severity head impacts such as when heading a football. However, there are few scientific data substantiating these concerns in terms of the biomechanical head response to impact. The present study aimed to develop a research methodology to investigate the biomechanical response of human subjects during intentional heading and identify strategies for reducing head impact severity. Methods: A controlled laboratory study was carried out with seven active football players, aged 20–23 and of average stature and weight. The subjects were fitted with photographic targets for kinematic analysis and instrumented to measure head linear/angular accelerations and neck muscle activity. Balls were delivered at two speeds (6 m/s and 8 m/s) as the subjects executed several specific forward heading manoeuvres in the standing position. Heading speeds up to 11 m/s were seen when the head closing speed was considered. One subject demonstrating averaged flexion–extension muscle activity phased with head acceleration data and upper torso kinematics was used to validate a biofidelic 50th percentile human model with a detailed head and neck. The model was exercised under ball incoming speeds of 6–7 m/s with parameter variations including torso/head alignment, neck muscle tensing, and follow through. The model output was subsequently compared with additional laboratory tests with football players (n = 3). Additional heading scenarios were investigated including follow through, non-active ball impact, and non-contact events. Subject and model head responses were evaluated with peak linear and rotational accelerations and maximum incremental head impact power. Results: Modelling of neck muscle tensing predicted lower head accelerations and higher neck loads whereas volunteer head acceleration reductions were not consistent. Modelling of head–torso alignment predicted a modest reduction in

  2. Investigating genotype specific response in photosynthetic behavior under drought stress and nitrogen limitation in Brassica rapa.

    NASA Astrophysics Data System (ADS)

    Pleban, J. R.; Mackay, D. S.; Ewers, B. E.; Weinig, C.; Aston, T.

    2015-12-01

    Challenges in terrestrial ecosystem modeling include characterizing the impact of stress on vegetation and the heterogeneous behavior of different species within the environment. In an effort to address these challenges the impacts of drought and nutrient limitation on the CO2 assimilation of multiple genotypes of Brassica rapa was investigated using the Farquhar Model (FM) of photosynthesis following a Bayesian parameterization and updating scheme. Leaf gas exchange and chlorophyll fluorescence measurements from an unstressed group (well-watered/well-fertilized) and two stressed groups (drought/well-fertilized and well-watered/nutrient limited) were used to estimate FM model parameters. Unstressed individuals were used to initialize Bayesian parameter estimation. Posterior mean estimates yielded a close fit with data as observed assimilation (An) closely matched predicted (Ap) with mean standard error for all individuals ranging from 0.8 to 3.1 μmol CO2 m-2 s-1. Posterior parameter distributions of the unstressed individuals were combined and fit to distributions to establish species level Bayesian priors of FM parameters for testing stress responses. Species level distributions of unstressed group identified mean maximum rates of carboxylation standardized to 25° (Vcmax25) as 101.8 μmol m-2 s-1 (± 29.0) and mean maximum rates of electron transport standardized to 25° (Jmax25) as 319.7 μmol m-2 s-1 (± 64.4). These updated priors were used to test the response of drought and nutrient limitations on assimilation. In the well-watered/nutrient limited group a decrease of 28.0 μmol m-2 s-1 was observed in mean estimate of Vcmax25, a decrease of 27.9 μmol m-2 s-1 in Jmax25 and a decrease in quantum yield from 0.40 mol photon/mol e- in unstressed individuals to 0.14 in the nutrient limited group. In the drought/well-fertilized group a decrease was also observed in Vcmax25 and Jmax25. The genotype specific unstressed and stressed responses were then used to

  3. Numerical and experimental investigation of the bending response of thin-walled composite cylinders

    NASA Technical Reports Server (NTRS)

    Fuchs, J. P.; Hyer, M. W.; Starnes, J. H., Jr.

    1993-01-01

    A numerical and experimental investigation of the bending behavior of six eight-ply graphite-epoxy circular cylinders is presented. Bending is induced by applying a known end-rotation to each end of the cylinders, analogous to a beam in bending. The cylinders have a nominal radius of 6 inches, a length-to-radius ratio of 2 and 5, and a radius-to-thickness ratio of approximately 160. A (+/- 45/0/90)S quasi-isotropic layup and two orthotropic layups, (+/- 45/0 sub 2)S and (+/- 45/90 sub 2)S, are studied. A geometrically nonlinear special-purpose analysis, based on Donnell's nonlinear shell equations, is developed to study the prebuckling responses and gain insight into the effects of non-ideal boundary conditions and initial geometric imperfections. A geometrically nonlinear finite element analysis is utilized to compare with the prebuckling solutions of the special-purpose analysis and to study the buckling and post buckling responses of both geometrically perfect and imperfect cylinders. The imperfect cylinder geometries are represented by an analytical approximation of the measured shape imperfections. Extensive experimental data are obtained from quasi-static tests of the cylinders using a test fixture specifically designed for the present investigation. A description of the test fixture is included. The experimental data are compared to predictions for both perfect and imperfect cylinder geometries. Prebuckling results are presented in the form of displacement and strain profiles. Buckling end-rotations, moments, and strains are reported, and predicted mode shapes are presented. Observed and predicted moment vs. end-rotation relations, deflection patterns, and strain profiles are illustrated for the post buckling responses. It is found that a geometrically nonlinear boundary layer behavior characterizes the prebuckling responses. The boundary layer behavior is sensitive to laminate orthotropy, cylinder geometry, initial geometric imperfections, applied end

  4. What does remote sensing do for ecology?

    NASA Technical Reports Server (NTRS)

    Roughgarden, J.; Running, S. W.; Matson, P. A.

    1991-01-01

    The application of remote sensing to ecological investigations is briefly discussed. Emphasis is given to the recruitment problem in marine population dynamics, the regional analysis of terrestrial ecosystems, and the monitoring of ecological changes. Impediments to the use of remote sensing data in ecology are addressed.

  5. The Coffee Berry Borer (Hypothenemus hampei) Invades Hawaii: Preliminary Investigations on Trap Response and Alternate Hosts

    PubMed Central

    Messing, Russell H.

    2012-01-01

    In August 2010 the coffee berry borer, Hypothenemus hampei, was first reported to have invaded the Kona coffee growing region of Hawaii, posing a severe economic challenge to the fourth largest agricultural commodity in the State. Despite its long and widespread occurrence throughout the tropics as the most serious pest of coffee, there are still discrepancies in the literature regarding several basic aspects of berry borer biology relevant to its control. In Kona coffee plantations, we investigated the beetles’ response to several trap and lure formulations, and examined the occurrence of beetles in seeds of alternate host plants occurring adjacent to coffee farms. While traps were shown to capture significant numbers of beetles per day, and the occurrence of beetles in alternate hosts was quite rare, the unique situation of coffee culture in Hawaii will make this pest extremely challenging to manage in the Islands. PMID:26466620

  6. The Coffee Berry Borer (Hypothenemus hampei) Invades Hawaii: Preliminary Investigations on Trap Response and Alternate Hosts.

    PubMed

    Messing, Russell H

    2012-07-11

    In August 2010 the coffee berry borer, Hypothenemus hampei, was first reported to have invaded the Kona coffee growing region of Hawaii, posing a severe economic challenge to the fourth largest agricultural commodity in the State. Despite its long and widespread occurrence throughout the tropics as the most serious pest of coffee, there are still discrepancies in the literature regarding several basic aspects of berry borer biology relevant to its control. In Kona coffee plantations, we investigated the beetles' response to several trap and lure formulations, and examined the occurrence of beetles in seeds of alternate host plants occurring adjacent to coffee farms. While traps were shown to capture significant numbers of beetles per day, and the occurrence of beetles in alternate hosts was quite rare, the unique situation of coffee culture in Hawaii will make this pest extremely challenging to manage in the Islands.

  7. Investigation of the Thermomechanical Response of Shape Memory Alloy Hybrid Composite Beams

    NASA Technical Reports Server (NTRS)

    Davis, Brian A.

    2005-01-01

    Previous work at NASA Langley Research Center (LaRC) involved fabrication and testing of composite beams with embedded, pre-strained shape memory alloy (SMA) ribbons. That study also provided comparison of experimental results with numerical predictions from a research code making use of a new thermoelastic model for shape memory alloy hybrid composite (SMAHC) structures. The previous work showed qualitative validation of the numerical model. However, deficiencies in the experimental-numerical correlation were noted and hypotheses for the discrepancies were given for further investigation. The goal of this work is to refine the experimental measurement and numerical modeling approaches in order to better understand the discrepancies, improve the correlation between prediction and measurement, and provide rigorous quantitative validation of the numerical model. Thermal buckling, post-buckling, and random responses to thermal and inertial (base acceleration) loads are studied. Excellent agreement is achieved between the predicted and measured results, thereby quantitatively validating the numerical tool.

  8. Time-series investigation of anomalous thermocouple responses in a liquid-metal-cooled reactor

    SciTech Connect

    Gross, K.C.; Planchon, H.P.; Poloncsik, J.

    1988-03-24

    A study was undertaken using SAS software to investigate the origin of anomalous temperature measurements recorded by thermocouples (TCs) in an instrumented fuel assembly in a liquid-metal-cooled nuclear reactor. SAS macros that implement univariate and bivariate spectral decomposition techniques were employed to analyze data recorded during a series of experiments conducted at full reactor power. For each experiment, data from physical sensors in the tests assembly were digitized at a sampling rate of 2/s and recorded on magnetic tapes for subsequent interactive processing with CMS SAS. Results from spectral and cross-correlation analyses led to the identification of a flow rate-dependent electromotive force (EMF) phenomenon as the origin of the anomalous TC readings. Knowledge of the physical mechanism responsible for the discrepant TC signals enabled us to device and justify a simple correction factor to be applied to future readings.

  9. A numerical investigation of vapor intrusion--the dynamic response of contaminant vapors to rainfall events.

    PubMed

    Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

    2012-10-15

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in determining

  10. A Numerical Investigation of Vapor Intrusion — the Dynamic Response of Contaminant Vapors to Rainfall Events

    PubMed Central

    Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

    2013-01-01

    The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1 m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in

  11. Agent-based computational model investigates muscle-specific responses to disuse-induced atrophy

    PubMed Central

    Martin, Kyle S.; Peirce, Shayn M.

    2015-01-01

    Skeletal muscle is highly responsive to use. In particular, muscle atrophy attributable to decreased activity is a common problem among the elderly and injured/immobile. However, each muscle does not respond the same way. We developed an agent-based model that generates a tissue-level skeletal muscle response to disuse/immobilization. The model incorporates tissue-specific muscle fiber architecture parameters and simulates changes in muscle fiber size as a result of disuse-induced atrophy that are consistent with published experiments. We created simulations of 49 forelimb and hindlimb muscles of the rat by incorporating eight fiber-type and size parameters to explore how these parameters, which vary widely across muscles, influence sensitivity to disuse-induced atrophy. Of the 49 muscles modeled, the soleus exhibited the greatest atrophy after 14 days of simulated immobilization (51% decrease in fiber size), whereas the extensor digitorum communis atrophied the least (32%). Analysis of these simulations revealed that both fiber-type distribution and fiber-size distribution influence the sensitivity to disuse atrophy even though no single tissue architecture parameter correlated with atrophy rate. Additionally, software agents representing fibroblasts were incorporated into the model to investigate cellular interactions during atrophy. Sensitivity analyses revealed that fibroblast agents have the potential to affect disuse-induced atrophy, albeit with a lesser effect than fiber type and size. In particular, muscle atrophy elevated slightly with increased initial fibroblast population and increased production of TNF-α. Overall, the agent-based model provides a novel framework for investigating both tissue adaptations and cellular interactions in skeletal muscle during atrophy. PMID:25722379

  12. Proteomic-based mechanistic investigation of low-dose radiation-induced cellular responses/effects

    SciTech Connect

    Chen, Xian

    2013-10-23

    The goal of our project is to apply our unique systems investigation strategy to reveal the molecular mechanisms underlying the radiation induction and transmission of oxidative damage, adaptive response, and bystander effect at low-doses. Beginning with simple in vitro systems such as fibroblast or epithelial pure culture, our amino acid-coded mass tagging (AACT) comparative proteomic platform will be used to measure quantitatively proteomic changes at high- or low-dose level with respect to their endogenous damage levels respectively, in which a broad range of unique regulated proteins sensitive to low-dose IR will be distinguished. To zoom in how these regulated proteins interact with other in the form of networks in induction/transmission pathways, these regulated proteins will be selected as baits for making a series of fibroblast cell lines that stably express each of them. Using our newly developed method of ?dual-tagging? quantitative proteomics that integrate the capabilities of natural complex expression/formation, simple epitope affinity isolation (not through tandem affinity purification or TAP), and ?in-spectra? AACT quantitative measurements using mass spectrometry (MS), we will be able to distinguish systematically interacting proteins with each bait in real time. Further, in addition to both proteome-wide (global differentially expressed proteins) and pathway-scale (bait-specific) profiling information, we will perform a computational network analysis to elucidate a global pathway/mechanisms underlying cellular responses to real-time low-dose IR. Similarly, we will extend our scheme to investigate systematically those induction/transmission pathways occurring in a fibroblast-epithelial interacting model in which the bystander cell (fibroblast) monitor the IR damage to the target cell (epithelial cell). The results will provide the proteome base (molecular mechanisms/pathways for signaling) for the low dose radiation-induced essential tissue

  13. The Investigation of Cortical Auditory Evoked Potentials Responses in Young Adults Having Musical Education

    PubMed Central

    Polat, Zahra; Ataş, Ahmet

    2014-01-01

    Background: In the literature, music education has been shown to enhance auditory perception for children and young adults. When compared to young adult non-musicians, young adult musicians demonstrate increased auditory processing, and enhanced sensitivity to acoustic changes. The evoked response potentials associated with the interpretation of sound are enhanced in musicians. Studies show that training also changes sound perception and cortical responses. The earlier training appears to lead to larger changes in the auditory cortex. Aims: Most cortical studies in the literature have used pure tones or musical instrument sounds as stimuli signals. The aim of those studies was to investigate whether musical education would enhance auditory cortical responses when speech signals were used. In this study, the speech sounds extracted from running speech were used as sound stimuli. Study Design: Non-randomized controlled study. Methods: The experimental group consists of young adults up to 21 years-old, all with a minimum of 4 years of musical education. The control group was selected from young adults of the same age without any musical education. The experiments were conducted by using a cortical evoked potential analyser and /m/, /t/ /g/ sound stimulation at the level of 65 dB SPL. In this study, P1 / N1 / P2 amplitude and latency values were measured. Results: Significant differences were found in the amplitude values of P1 and P2 (p<0.05). The differences among the latencies were not found to be significantly important (p>0.05). Conclusion: The results obtained in our study indicate that musical experience has an effect on the nervous system and this can be seen in cortical auditory evoked potentials recorded when the subjects hear speech. PMID:25667787

  14. Experimental Investigation and Optimization of Response Variables in WEDM of Inconel - 718

    NASA Astrophysics Data System (ADS)

    Karidkar, S. S.; Dabade, U. A.

    2016-02-01

    Effective utilisation of Wire Electrical Discharge Machining (WEDM) technology is challenge for modern manufacturing industries. Day by day new materials with high strengths and capabilities are being developed to fulfil the customers need. Inconel - 718 is similar kind of material which is extensively used in aerospace applications, such as gas turbine, rocket motors, and spacecraft as well as in nuclear reactors and pumps etc. This paper deals with the experimental investigation of optimal machining parameters in WEDM for Surface Roughness, Kerf Width and Dimensional Deviation using DoE such as Taguchi methodology, L9 orthogonal array. By keeping peak current constant at 70 A, the effect of other process parameters on above response variables were analysed. Obtained experimental results were statistically analysed using Minitab-16 software. Analysis of Variance (ANOVA) shows pulse on time as the most influential parameter followed by wire tension whereas spark gap set voltage is observed to be non-influencing parameter. Multi-objective optimization technique, Grey Relational Analysis (GRA), shows optimal machining parameters such as pulse on time 108 Machine unit, spark gap set voltage 50 V and wire tension 12 gm for optimal response variables considered for the experimental analysis.

  15. A theoretical investigation on influences of slab tracks on vertical dynamic responses of railway viaducts

    NASA Astrophysics Data System (ADS)

    Shi, Li; Cai, Yuanqiang; Wang, Peng; Sun, Honglei

    2016-07-01

    A railway viaduct model consisting of infinite spans of elastically-supported girders carrying a slab track of infinite length is established to investigate the influence of the slabs on the vertical dynamic response of the viaduct, when a moving harmonic point load or a moving sprung wheel is applied. The infinite rail, the discontinuous slabs and girders of identical span lengths are idealized as Euler-Bernoulli beams. The rail fasteners, the cushion layer beneath the slab and the elastic bearings at the girder supports are represented by discretely distributed springs of hysteretic damping. Due to the repetitive nature of the girders, the model can be divided into periodic three-beam units by the span length of the girder, and then solved analytically in the frequency domain using the property of periodic structure. Besides the first natural frequency of the girder with elastic bearings, it is found that the resonance frequency of the slab on the cushion layer has a significant influence on the dynamic response of the track and the girder. Parametric excitations due to the moving wheel periodically passing the discontinuous slabs contribute significantly to the wheel/rail interactions.

  16. Piloted Simulator Investigation of Techniques to Achieve Attitude Command Response with Limited Authority Servos

    NASA Technical Reports Server (NTRS)

    Key, David L.; Heffley, Robert K.

    2002-01-01

    The purpose of the study was to develop generic design principles for obtaining attitude command response in moderate to aggressive maneuvers without increasing SCAS series servo authority from the existing +/- 10%. In particular, to develop a scheme that would work on the UH-60 helicopter so that it can be considered for incorporation in future upgrades. The basic math model was a UH-60A version of GENHEL. The simulation facility was the NASA-Ames Vertical Motion Simulator (VMS). Evaluation tasks were Hover, Acceleration-Deceleration, and Sidestep, as defined in ADS-33D-PRF for Degraded Visual Environment (DVE). The DVE was adjusted to provide a Usable Cue Environment (UCE) equal to two. The basic concept investigated was the extent to which the limited attitude command authority achievable by the series servo could be supplemented by a 10%/sec trim servo. The architecture used provided angular rate feedback to only the series servo, shared the attitude feedback between the series and trim servos, and when the series servo approached saturation the attitude feedback was slowly phased out. Results show that modest use of the trim servo does improve pilot ratings, especially in and around hover. This improvement can be achieved with little degradation in response predictability during moderately aggressive maneuvers.

  17. A numerical investigation of pumping-test responses from contiguous aquifers

    NASA Astrophysics Data System (ADS)

    Rafini, Silvain; Chesnaux, Romain; Ferroud, Anouck

    2017-03-01

    Adequate groundwater management requires models capable of representing the heterogeneous nature of aquifers. A key point is the theoretical knowledge of flow behaviour in various heterogeneous archetypal conditions, using analytically or numerically based models. This study numerically investigates transient pressure transfers between linearly contiguous homogeneous domains with non-equal hydraulic properties, optionally separated by a conductive fault. Responses to pumping are analysed in terms of time-variant flow dimension, n. Two radial stages are predicted (n: 2 - 2) with a positive or negative vertical offset depending of the transmissivity ratio between domains. A transitional n = 4 segment occurs when the non-pumped domain is more transmissive (n: 2 - 4 - 2), and a fractional flow segment occurs when the interface is a fault (n: 2 - 4 - 1.5 - 2). The hydrodynamics are generally governed by the transmissivity ratio; the storativity ratio impact is limited. The drawdown log-derivative late stabilization, recorded at any well, does not tend to reflect the local transmissivity but rather the higher transmissivity region, possibly distant and blind, as it predominantly supplies groundwater to the well. This study provides insights on the behaviour of non-uniform aquifers and on theoretical responses that can aid practitioners to detect such conditions in nature.

  18. The brain’s response to pleasant touch: an EEG investigation of tactile caressing

    PubMed Central

    Singh, Harsimrat; Bauer, Markus; Chowanski, Wojtek; Sui, Yi; Atkinson, Douglas; Baurley, Sharon; Fry, Martin; Evans, Joe; Bianchi-Berthouze, Nadia

    2014-01-01

    Somatosensation as a proximal sense can have a strong impact on our attitude toward physical objects and other human beings. However, relatively little is known about how hedonic valence of touch is processed at the cortical level. Here we investigated the electrophysiological correlates of affective tactile sensation during caressing of the right forearm with pleasant and unpleasant textile fabrics. We show dissociation between more physically driven differential brain responses to the different fabrics in early somatosensory cortex – the well-known mu-suppression (10–20 Hz) – and a beta-band response (25–30 Hz) in presumably higher-order somatosensory areas in the right hemisphere that correlated well with the subjective valence of tactile caressing. Importantly, when using single trial classification techniques, beta-power significantly distinguished between pleasant and unpleasant stimulation on a single trial basis with high accuracy. Our results therefore suggest a dissociation of the sensory and affective aspects of touch in the somatosensory system and may provide features that may be used for single trial decoding of affective mental states from simple electroencephalographic measurements. PMID:25426047

  19. Investigation on the relationship between overpressure and sub-harmonic response from encapsulated microbubbles

    NASA Astrophysics Data System (ADS)

    Wu, Jun; Fan, Ting-Bo; Xu, Di; Zhang, Dong

    2014-10-01

    Sub-harmonic component generated from microbubbles is proven to be potentially used in noninvasive blood pressure measurement. Both theoretical and experimental studies are performed in the present work to investigate the dependence of the sub-harmonic generation on the overpressure with different excitation pressure amplitudes and pulse lengths. With 4-MHz ultrasound excitation at an applied acoustic pressure amplitude of 0.24 MPa, the measured sub-harmonic amplitude exhibits a decreasing change as overpressure increases; while non-monotonic change is observed for the applied acoustic pressures of 0.36 MPa and 0.48 MPa, and the peak position in the curve of the sub-harmonic response versus the overpressure shifts toward higher overpressure as the excitation pressure amplitude increases. Furthermore, the exciting pulse with long duration could lead to a better sensitivity of the sub-harmonic response to overpressure. The measured results are explained by the numerical simulations based on the Marmottant model. The numerical simulations qualitatively accord with the measured results. This work might provide a preliminary proof for the optimization of the noninvasive blood pressure measurement through using sub-harmonic generation from microbubbles.

  20. Numerical investigation of the hydroelastic response in cavitating flow around a flexible hydrofoil

    NASA Astrophysics Data System (ADS)

    Wu, Q.; Huang, B.; Wang, G. Y.; Wang, J. D.

    2015-01-01

    The objective of this paper is to investigate the hydroelastic response of cavitating flows around a flexible hydrofoil. The numerical simulations are performed by solving the incompressible and unsteady Reynolds Average Navier-Stokes (URANS) equations via the commercial CFD software ANSYS CFX. The k-ω SST turbulence model with the turbulence viscosity correction and the Kubota cavitation model are introduced to the present simulations. The results showed that the cavitation has significantly affected the foil deformation and the evolution of the transient cavity shape and the corresponding hydrodynamic response with time can be divided into three stages: during the development of the attached cavity, the cavity formed on the suction side of the flexible hydrofoil is much larger with a steeper slope of the cavity area, which is caused by the increase of the effective angle of attack due to the twist deformation. During the vortex-cavitation interaction process, the hydrodynamic loads for the rigid hydrofoil remain relatively flat, while that for the flexible hydrofoil fluctuates with high frequency because of the foil deformation, leading to a more complex cavitation pattern due to the interaction with the foil vibration. During the cavity shedding process, both the primary and the residual cavities shed downstream totally, together with the counter-rotational vortex structures, corresponding to a sharp drop in the hydrodynamic loads. The larger effective angle of attack leads to the advanced cavity inception of the next cavitation period.

  1. Application of randomized response techniques for investigating cannabis use by Spanish university students.

    PubMed

    Cobo, Beatriz; Rueda, M Mar; López-Torrecillas, Francisca

    2016-08-02

    Cannabis is the most widely used illicit drug in developed countries, and has a significant impact on mental and physical health in the general population. Although the evaluation of levels of substance use is difficult, a method such as the randomized response technique (RRT), which includes both a personal component and an assurance of confidentiality, provides a combination which can achieve a considerable degree of accuracy. Various RRT surveys have been conducted to measure the prevalence of drug use, but to date no studies have been made of the effectiveness of this approach in surveys with respect to quantitative variables related to drug use. This paper describes a probabilistic, stratified sample of 1146 university students asking sensitive quantitative questions about cannabis use in Spanish universities, conducted using the RRT. On comparing the results of the direct question (DQ) survey and those of the randomized response (RR) survey, we find that the number of cannabis cigarettes consumed during the past year (DQ = 3, RR = 17 approximately), and the number of days when consumption took place (DQ = 1, RR = 7) are much higher with RRT. The advantages of RRT, reported previously and corroborated in our study, make it a useful method for investigating cannabis use. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Clinical investigation of the lesions responsible for sensory disturbance in Minamata disease.

    PubMed

    Uchino, M; Mita, S; Satoh, H; Hirano, T; Arimura, K; Nakagawa, M; Nakamura, M; Uyama, E; Ando, Y; Wakamiya, J; Futatsuka, M

    2001-11-01

    To clarify the lesions responsible for sensory disturbance in Minamata disease (MD), we clinically investigated the characteristics of sensory disturbance. In all patients with the classical type MD, two-point discrimination was severely disturbed, but the involvement of superficial sensation was relatively mild. On short-latency somatosensory evoked potential study, the component corresponding to N20 was completely absent with normal N9, N11, and N13 components. Although 14 of 38 chronic MD patients demonstrated intact superficial sensation, 10 of these 14 showed mild to moderate disturbance in two-point discrimination. The two-point discrimination in chronic MD patients was significantly high irrespective of the disturbance of superficial sensation. These findings suggest that the sensory disturbance of MD patients may mainly be caused by a lesion in the sensory cortex rather than in the peripheral nerves. However, other foci could be also responsible for the sensory impairment, since 9 of 38 chronic MD patients showed intact two-point discrimination.

  3. Growth performance and gastrointestinal microbial ecology responses of piglets receiving Saccharomyces cerevisiae fermentation products after an oral challenge with Escherichia coli (K88).

    PubMed

    Kiarie, E; Bhandari, S; Scott, M; Krause, D O; Nyachoti, C M

    2011-04-01

    The effects of Saccharomyces cerevisiae fermentation products (YFP) on growth performance and gastrointestinal (GIT) microbial ecology in 90 weanling pigs orally challenged with Escherichia coli K88(+) (ETEC) were investigated. The YFP were an original YFP product (XPC) and a water-suspendable yeast fermentation prototype (WSYFP) from a commercial company. Treatments consisted of a negative control (NC, no in-feed or in-water additive), carbadox (AB, 55 mg of carbadox/kg of feed), XPC (in feed, 0.2%), and WSYFP (in water, 0.5, 1, or 2 g/pig per day), and each was allotted to 5 pens (3 pigs/pen). The diets met the 1998 NRC specifications. Pigs were acclimated to treatments for a 7-d period before an ETEC challenge. On d 8, blood was collected from pigs to determine the baseline packed cell volume (PCV) measurement, and pigs were orally challenged with ETEC. At various time points postchallenge, blood samples were taken, performance measures and fecal consistency scores were recorded, and gut digesta and tissue samples were taken to evaluate GIT morphology, microbial ecology, and metabolites. Preplanned contrasts were used for comparison. Pigs receiving YFP had greater ADFI than NC pigs on d 3 (424 vs. 378 g/d; P = 0.01) and d 7 (506 vs. 458 g/d; P = 0.03) postchallenge. This effect of YFP on ADFI was similar to that of AB on d 3, but pigs receiving AB ate more (576 vs. 506 g/d; P = 0.03) at d 7 than pigs receiving YFP. Pigs exhibited reduced (P < 0.001) PCV upon ETEC challenge; however, pigs receiving additives sustained a greater (P < 0.05) PCV at 72 h compared with the NC group. Compared with the NC pigs, pigs receiving YFP showed a smaller (P < 0.05) number of ileal mucosa adherent ETEC and prevalence of the order Enterobacteriales in the ileal digesta, which corresponded to less (5.09 vs. 6.97 mg/dL; P = 0.03) colonic ammonia on d 7 postchallenge. Most of the indices for ileal digesta bacterial richness and diversity were greater (P < 0.01) for YFP pigs compared

  4. Investigation of Nonlinear Site Response and Seismic Compression from Case History Analysis and Laboratory Testing

    NASA Astrophysics Data System (ADS)

    Yee, Eric

    ). Aside from the expected strong influence of RC, increasing fines content is found to generally decrease volume change for fines fractions consisting of silts and clayey silts with moderate to low plasticity. With truly non-plastic fines (rock flour), cyclic volume change increases with FC. Some materials also exhibit an effect of as-compacted saturation in which moderate saturation levels associated with high matric suction cause volume change to decrease. A preliminary empirical model to capture these effects is presented. The balance of the dissertation is related to a case history of strongly nonlinear site response and seismic compression associated with a free-field downhole array installed near the Service Hall at the Kashiwazaki-Kariwa nuclear power plant, which recorded strong ground motions from the Mw 6.6 2007 Niigata-ken Chuetsu-oki earthquake. Site conditions at the array consist of about 70 m of medium-dense sands overlying clayey bedrock, with ground water located at 45 m. Ground shaking at the bedrock level had geometric mean peak accelerations of 0.55 g which is reduced to 0.4 g at the ground surface, indicating nonlinear site response. Ground settlements of approximately 15+/-5 cm occurred at the site. A site investigation was performed to develop relevant soil properties for ground response and seismic compression analysis, including shear wave velocities, shear strength, relative density, and modulus reduction and damping curves. (Abstract shortened by UMI.)

  5. Metabolomics in chemical ecology.

    PubMed

    Kuhlisch, Constanze; Pohnert, Georg

    2015-07-01

    Chemical ecology elucidates the nature and role of natural products as mediators of organismal interactions. The emerging techniques that can be summarized under the concept of metabolomics provide new opportunities to study such environmentally relevant signaling molecules. Especially comparative tools in metabolomics enable the identification of compounds that are regulated during interaction situations and that might play a role as e.g. pheromones, allelochemicals or in induced and activated defenses. This approach helps overcoming limitations of traditional bioassay-guided structure elucidation approaches. But the power of metabolomics is not limited to the comparison of metabolic profiles of interacting partners. Especially the link to other -omics techniques helps to unravel not only the compounds in question but the entire biosynthetic and genetic re-wiring, required for an ecological response. This review comprehensively highlights successful applications of metabolomics in chemical ecology and discusses existing limitations of these novel techniques. It focuses on recent developments in comparative metabolomics and discusses the use of metabolomics in the systems biology of organismal interactions. It also outlines the potential of large metabolomics initiatives for model organisms in the field of chemical ecology.

  6. The Autoimmune Ecology

    PubMed Central

    Anaya, Juan-Manuel; Ramirez-Santana, Carolina; Alzate, Maria A.; Molano-Gonzalez, Nicolas; Rojas-Villarraga, Adriana

    2016-01-01

    Autoimmune diseases (ADs) represent a heterogeneous group of disorders that affect specific target organs or multiple organ systems. These conditions share common immunopathogenic mechanisms (i.e., the autoimmune tautology), which explain the clinical similarities they have among them as well as their familial clustering (i.e., coaggregation). As part of the autoimmune tautology, the influence of environmental exposure on the risk of developing ADs is paramount (i.e., the autoimmune ecology). In fact, environment, more than genetics, shapes immune system. Autoimmune ecology is akin to exposome, that is all the exposures – internal and external – across the lifespan, interacting with hereditary factors (both genetics and epigenetics) to favor or protect against autoimmunity and its outcomes. Herein, we provide an overview of the autoimmune ecology, focusing on the immune response to environmental agents in general, and microbiota, cigarette smoking, alcohol and coffee consumption, socioeconomic status (SES), gender and sex hormones, vitamin D, organic solvents, and vaccines in particular. Inclusion of the autoimmune ecology in disease etiology and health will improve the way personalized medicine is currently conceived and applied. PMID:27199979

  7. Cascading ecological effects of eliminating fishery discards

    PubMed Central

    Heath, Michael R.; Cook, Robin M.; Cameron, Angus I.; Morris, David J.; Speirs, Douglas C.

    2014-01-01

    Discarding by fisheries is perceived as contrary to responsible harvesting. Legislation seeking to end the practice is being introduced in many jurisdictions. However, discarded fish are food for a range of scavenging species; so, ending discarding may have ecological consequences. Here we investigate the sensitivity of ecological effects to discarding policies using an ecosystem model of the North Sea—a region where 30–40% of trawled fish catch is currently discarded. We show that landing the entire catch while fishing as usual has conservation penalties for seabirds, marine mammals and seabed fauna, and no benefit to fish stocks. However, combining landing obligations with changes in fishing practices to limit the capture of unwanted fish results in trophic cascades that can benefit birds, mammals and most fish stocks. Our results highlight the importance of considering the broader ecosystem consequences of fishery management policy, since species interactions may dissipate or negate intended benefits. PMID:24820200

  8. A theoretical investigation of human skin thermal response to near-infrared laser irradiation

    NASA Astrophysics Data System (ADS)

    Dai, Tianhong; Pikkula, Brian M.; Wang, Lihong V.; Anvari, Bahman

    2004-07-01

    Near-infrared wavelengths are absorbed less by epidermal melanin mainly located at the basal layer of epidermis (dermo-epidermal junction), and penetrate deeper into human skin dermis and blood than visible wavelengths. Therefore, laser irradiation using near-infrared wavelength may improve the therapeutic outcome of cutaneous hyper-vascular malformations in moderately to heavily pigmented skin patients and those with large-sized blood vessels or blood vessels extending deeply into the skin. A mathematical model composed of a Monte Carlo algorithm to estimate the distribution of absorbed light followed by numerical solution of a bio-heat diffusion equation was utilized to investigate the thermal response of human skin to near-infrared laser irradiation, and compared it with that to visible laser irradiation. Additionally, the effect of skin surface cooling on epidermal protection was theoretically investigated. Simulation results indicated that 940 nm wavelength is superior to 810 and 1064 nm in terms of the ratio of light absorption by targeted blood vessel to the absorption by the basal layer of epidermis, and is more efficient than 595 nm wavelength for the treatment of patients with large-sized blood vessels and moderately to heavily pigmented skin. Dermal blood content has a considerable effect on the laser-induced peak temperature at the basal layer of epidermis, while the effect of blood vessel size is minimum.

  9. Investigating the zonal wind response to SST warming using transient ensemble AGCM experiments

    SciTech Connect

    Palipane, Erool; Lu, Jian; Staten, Paul; Chen, Gang; Schneider, Edwin K.

    2016-04-13

    The response of the atmospheric circulation to greenhouse gas-induced SST warming is investigated using large ensemble experiments with two AGCMs, with a focus on the robust feature of the poleward shift of the eddy driven jet. In these experiments, large ensembles of simulations are conducted by abruptly switching the SST forcing on from January 1st to focus on the wintertime circulation adjustment. A hybrid, nite amplitude wave activity budget analysis is performed to elucidate the nonlinear and irreversible aspects of the eddy-mean ow interaction during the adjustment of the zonal wind towards a poleward shifted state. The results conrm the results from earlier more idealized studies, particularly the importance of reduced dissipation of wave activity and the dominant role of the decrease of elective diffusivity in the midlatitudes. Some quantitative discrences do exist between the wave activity budgets of our more realistic experiments and the earlier idealized ones, including larger wave activity tendency and diabatic wave source, and a somewhat greater role of the changing PV gradient in the total reduction of the wave activity dissipation. The relative importance of wave breaking-induced PV mixing versus diabatic PV source in the evolution of the Lagrangian PV gradient is also investigated. The former plays the dominant role in the PV gradient formation during the initial phase of the jet shift, while the latter even opposes the evolution of the Lagrangian PV gradient at times. The possible involvement of the wave reflection level at the poleward flank of the mean jet is also investigated.

  10. Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations

    USGS Publications Warehouse

    Rode, Karyn D.; Regehr, Eric V.; Douglas, David C.; Durner, George; Derocher, Andrew E.; Thiemann, Gregory W.; Budge, Suzanne M.

    2014-01-01

    Polar bears (Ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the Beaufort, Chukchi, and Bering Seas. In this study, we compared the body size, condition, and recruitment of polar bears captured in the Chukchi and Bering Seas (CS) between two periods (1986–1994 and 2008–2011) when declines in sea ice habitat occurred. In addition, we compared metrics for the CS population 2008–2011 with those of the adjacent southern Beaufort Sea (SB) population where loss in sea ice habitat has been associated with declines in body condition, size, recruitment, and survival. We evaluated how variation in body condition and recruitment were related to feeding ecology. Comparing habitat conditions between populations, there were twice as many reduced ice days over continental shelf waters per year during 2008–2011 in the SB than in the CS. CS polar bears were larger and in better condition, and appeared to have higher reproduction than SB bears. Although SB and CS bears had similar diets, twice as many bears were fasting in spring in the SB than in the CS. Between 1986–1994 and 2008–2011, body size, condition, and recruitment indices in the CS were not reduced despite a 44-day increase in the number of reduced ice days. Bears in the CS exhibited large body size, good body condition, and high indices of recruitment compared to most other populations measured to date. Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears. Geographic differences in the response of polar bears to climate change are relevant to range-wide forecasts for this and other ice-dependent species.

  11. Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations.

    PubMed

    Rode, Karyn D; Regehr, Eric V; Douglas, David C; Durner, George; Derocher, Andrew E; Thiemann, Gregory W; Budge, Suzanne M

    2014-01-01

    Polar bears (Ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the Beaufort, Chukchi, and Bering Seas. In this study, we compared the body size, condition, and recruitment of polar bears captured in the Chukchi and Bering Seas (CS) between two periods (1986-1994 and 2008-2011) when declines in sea ice habitat occurred. In addition, we compared metrics for the CS population 2008-2011 with those of the adjacent southern Beaufort Sea (SB) population where loss in sea ice habitat has been associated with declines in body condition, size, recruitment, and survival. We evaluated how variation in body condition and recruitment were related to feeding ecology. Comparing habitat conditions between populations, there were twice as many reduced ice days over continental shelf waters per year during 2008-2011 in the SB than in the CS. CS polar bears were larger and in better condition, and appeared to have higher reproduction than SB bears. Although SB and CS bears had similar diets, twice as many bears were fasting in spring in the SB than in the CS. Between 1986-1994 and 2008-2011, body size, condition, and recruitment indices in the CS were not reduced despite a 44-day increase in the number of reduced ice days. Bears in the CS exhibited large body size, good body condition, and high indices of recruitment compared to most other populations measured to date. Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears. Geographic differences in the response of polar bears to climate change are relevant to range-wide forecasts for this and other ice-dependent species.

  12. Investigating Assessment Bias for Constructed Response Explanation Tasks: Implications for Evaluating Performance Expectations for Scientific Practice

    NASA Astrophysics Data System (ADS)

    Federer, Meghan Rector

    Assessment is a key element in the process of science education teaching and research. Understanding sources of performance bias in science assessment is a major challenge for science education reforms. Prior research has documented several limitations of instrument types on the measurement of students' scientific knowledge (Liu et al., 2011; Messick, 1995; Popham, 2010). Furthermore, a large body of work has been devoted to reducing assessment biases that distort inferences about students' science understanding, particularly in multiple-choice [MC] instruments. Despite the above documented biases, much has yet to be determined for constructed response [CR] assessments in biology and their use for evaluating students' conceptual understanding of scientific practices (such as explanation). Understanding differences in science achievement provides important insights into whether science curricula and/or assessments are valid representations of student abilities. Using the integrative framework put forth by the National Research Council (2012), this dissertation aimed to explore whether assessment biases occur for assessment practices intended to measure students' conceptual understanding and proficiency in scientific practices. Using a large corpus of undergraduate biology students' explanations, three studies were conducted to examine whether known biases of MC instruments were also apparent in a CR instrument designed to assess students' explanatory practice and understanding of evolutionary change (ACORNS: Assessment of COntextual Reasoning about Natural Selection). The first study investigated the challenge of interpreting and scoring lexically ambiguous language in CR answers. The incorporation of 'multivalent' terms into scientific discourse practices often results in statements or explanations that are difficult to interpret and can produce faulty inferences about student knowledge. The results of this study indicate that many undergraduate biology majors

  13. An integrative approach to assess ecological risks of surface water contamination for fish populations.

    PubMed

    Santos, Raphael; Joyeux, Aude; Besnard, Aurélien; Blanchard, Christophe; Halkett, Cédric; Bony, Sylvie; Sanchez, Wilfried; Devaux, Alain

    2017-01-01

    Contamination of aquatic ecosystems is considered as one of the main threats to global freshwater biodiversity. Within the European Water Framework Directive (EU-WFD) a particular attention is dedicated to assess ecological risks of surface water contamination and mitigation of chemical pressures on aquatic ecosystems. In this work, we evaluated ecological risks of surface water contamination for fish populations in four EU-WFD rivers through an integrative approach investigating three Lines of Evidence (chemical contamination, biomarker responses as early warning signals of contamination impacting individuals and ecological analyses as an indicator of fish community disturbances). This work illustrates through 4 case studies the complementary role of biomarkers, chemical and ecological analyses which, used in combination, provide fundamental information to understand impacts of chemical pressures that can affect fish population dynamics. We discuss the limitations of this approach and future improvements needed within the EU-WFD to assess ecological risk of river contamination for fish populations.

  14. The Effects of Student Response Systems on Performance and Satisfaction: An Investigation in a Tax Accounting Class

    ERIC Educational Resources Information Center

    Cummings, Richard G.; Hsu, Maxwell

    2007-01-01

    Does the use of student response systems (clickers) in the classroom increase student performance on exams? Do students perceive a benefit to using clickers in the classroom? This study investigates the effect of student response systems on accounting students' learning outcome and perceived satisfaction. Results show that, though the use of…

  15. Investigating the long-term geodetic response to magmatic intrusions at volcanoes in northern California

    NASA Astrophysics Data System (ADS)

    Parker, A. L.; Biggs, J.; Annen, C.; Houseman, G. A.; Yamasaki, T.; Wright, T. J.; Walters, R. J.; Lu, Z.

    2014-12-01

    Ratios of intrusive to extrusive activity at volcanic arcs are thought to be high, with estimates ranging between 5:1 and 30:1. Understanding the geodetic response to magmatic intrusion is therefore fundamental to large-scale studies of volcano deformation, providing insight into the dynamics of the inter-eruptive period of the volcano cycle and the building of continental crust. In northern California, we identify two volcanoes - Medicine Lake Volcano (MLV) and Lassen Volcanic Center (LaVC) - that exhibit long-term (multi-decadal) subsidence. We test the hypothesis that deformation at these volcanoes results from processes associated with magmatic intrusions. We first constrain the spatial and temporal characteristics of the deformation fields, establishing the first time-series of deformation at LaVC using InSAR data, multi-temporal analysis techniques and global weather models. Although the rates of deformation at the two volcanoes are similar (~1 cm/yr), our results show that the ratio of vertical to horizontal displacements is significantly different, suggesting contrasting source geometries. To test the origin of deformation, we develop modeling strategies to investigate thermal and viscoelastic processes associated with magmatic intrusions. The first model we develop couples analytical geodetic models to a numerical model of volume loss due to cooling and crystallization based upon temperature-melt fraction relationships from petrological experiments. This model provides evidence that magmatic intrusion at MLV has occurred more recently than the last eruption ~1 ka. The second model we test uses a finite element approach to simulate the time-dependent viscoelastic response of the crust to magmatic intrusion. We assess the magnitude and timescales of ground deformation that may result from these processes, exploring the model parameter space before applying the models to our InSAR observations of subsidence in northern California.

  16. Transient freezing behavior in photophobic responses of Euglena gracilis investigated in a microfluidic device.

    PubMed

    Ozasa, Kazunari; Lee, Jeesoo; Song, Simon; Maeda, Mizuo

    2014-10-01

    We found that the transient freezing behavior in photophobic responses of Euglena gracilis is a good indicator of the metabolic status of the cells. The transient blue light photophobic responses of E. gracilis cells were investigated on-chip using a new measurement, 'trace momentum' (TM), to evaluate their swimming activity quantitatively in real time. When blue light of intensity >30 mW cm(-2) was repeatedly switched on and off, a large negative spike in the TM was observed at the onset of the 'blue-light-off' phase. Single-cell trace analysis at a blue light intensity of 40 mW cm(-2) showed that 48% (on average, n = 15) of tumbling Euglena cells ceased activity ('freezing') for 2-30 s at the onset of blue-light-off before commencing forward motion in a straight line (termed 'straightforward swimming'), while 45% smoothly commenced straightforward swimming without delay. The proportion of freezing Euglena cells depended on the blue light intensity (only 20% at 20 mW cm(-2)). When the cells were stimulated by four blue light pulses at the higher intensity, without pre-exposure, the transient freezing behavior was more prominent but, on repeating the stimuli after an 80 min interval in red light, the same cells did not freeze. This shows that the metabolism of the cells had changed to anti-freezing during the interval. The relationship between the interval time with/without light irradiation and the blue light adaptation was elucidated experimentally. The origin of the freezing behavior is considered to be a shortage of a metabolic substance that promotes smooth switching of flagellum movement from in situ rotation mode to a straightforward swimming mode.

  17. Numerical investigation of thermal response of laser-irradiated biological tissue phantoms embedded with gold nanoshells.

    PubMed

    Phadnis, Akshay; Kumar, Sumit; Srivastava, Atul

    2016-10-01

    The work presented in this paper focuses on numerically investigating the thermal response of gold nanoshells-embedded biological tissue phantoms with potential applications into photo-thermal therapy wherein the interest is in destroying the cancerous cells with minimum damage to the surrounding healthy cells. The tissue phantom has been irradiated with a pico-second laser. Radiative transfer equation (RTE) has been employed to model the light-tissue interaction using discrete ordinate method (DOM). For determining the temperature distribution inside the tissue phantom, the RTE has been solved in combination with a generalized non-Fourier heat conduction model namely the dual phase lag bio-heat transfer model. The numerical code comprising the coupled RTE-bio-heat transfer equation, developed as a part of the current work, has been benchmarked against the experimental as well as the numerical results available in the literature. It has been demonstrated that the temperature of the optical inhomogeneity inside the biological tissue phantom embedded with gold nanoshells is relatively higher than that of the baseline case (no nanoshells) for the same laser power and operation time. The study clearly underlines the impact of nanoshell concentration and its size on the thermal response of the biological tissue sample. The comparative study concerned with the size and concentration of nanoshells showed that 60nm nanoshells with concentration of 5×10(15)mm(-3) result into the temperature levels that are optimum for the irreversible destruction of cancer infected cells in the context of photo-thermal therapy. To the best of the knowledge of the authors, the present study is one of the first attempts to quantify the influence of gold nanoshells on the temperature distributions inside the biological tissue phantoms upon laser irradiation using the dual phase lag heat conduction model.

  18. Investigation of tryptophan hydroxylase 2 (TPH2) in schizophrenia and in the response to antipsychotics.

    PubMed

    Schuhmacher, Anna; Becker, Tim; Rujescu, Dan; Quednow, Boris B; Lennertz, Leonhard; Wagner, Michael; Benninghoff, Jens; Rietschel, Marcella; Häfner, Heinz; Franke, Petra; Wölwer, Wolfgang; Gaebel, Wolfgang; Maier, Wolfgang; Mössner, Rainald

    2012-08-01

    Serotonergic transmission is considered relevant in the pathophysiology and the treatment of schizophrenia. Tryptophan hydroxylase (TPH) is the rate limiting enzyme in the biosynthesis of serotonin. While the TPH1 gene has been found to be associated with schizophrenia, studies focusing on TPH2 variants did not yield conclusive results for schizophrenia or the response to antipsychotic medication. We analyzed eleven TPH2 SNPs in two case-control samples consisting of 4453 individuals in total. Six SNPs were selected because of their potential functional relevance (rs4570625, rs11178997, rs11178998, rs7954758, rs7305115, and, rs4290270) and were supported by another 5 tagging SNPs selected based on HapMap LD information. In the discovery sample (1476 individuals), we observed a significant association with schizophrenia for rs10784941 (p = 0.009, OR minor G-allele 0.82 [0.71-0.95]) and rs4565946 (p = 0.011, OR minor T-allele 0.83 [0.71-0.96]). Association was also observed with a common rs4570625-rs4565946 haplotype (OR G-C haplotype 1.20 [1.02-1.40]; p = 0.0046). Single-marker associations could not be replicated in the replication sample consisting of 2977 individuals, but there was a strong trend regarding the rs4570625-rs4565946 G-C haplotype (OR 1.10 [0.98-1.24]; p(one-sided test) = 0.054). In smaller sub-samples, the rare rs4570625-rs4565946 T-T haplotype was associated with reduced processing speed (n = 193, p = 0.004) and sensorimotor gating (n = 68, p = 0.006) of schizophrenia patients. TPH2 variants and the rs4570625-rs4565946 G-C haplotype did not influence the beneficial response to antipsychotic drugs (n = 210) after four weeks of treatment administering the Positive and Negative Syndrome Scale of Schizophrenia (PANSS). We also investigated the association of the SNPs to treatment response, but did not get significant results. In sum, our results argue for only a minor role of TPH2 in schizophrenia.

  19. Large-scale investigation of the parameters in response to Eimeria maxima challenge in broilers.

    PubMed

    Hamzic, E; Bed'Hom, B; Juin, H; Hawken, R; Abrahamsen, M S; Elsen, J M; Servin, B; Pinard-van der Laan, M H; Demeure, O

    2015-04-01

    Coccidiosis, a parasitic disease of the intestinal tract caused by members of the genera Eimeria and Isospora, is one of the most common and costly diseases in chicken. The aims of this study were to assess the effect of the challenge and level of variability of measured parameters in chickens during the challenge with Eimeria maxima. Furthermore, this study aimed to investigate which parameters are the most relevant indicators of the health status. Finally, the study also aimed to estimate accuracy of prediction for traits that cannot be measured on large scale (such as intestinal lesion score and fecal oocyst count) using parameters that can easily be measured on all animals. The study was performed in 2 parts: a pilot challenge on 240 animals followed by a large-scale challenge on 2,024 animals. In both experiments, animals were challenged with 50,000 Eimeria maxima oocysts at 16 d of age. In the pilot challenge, all animals were measured for BW gain, plasma coloration, hematocrit, and rectal temperature and, in addition, a subset of 48 animals was measured for oocyst count and the intestinal lesion score. All animals from the second challenge were measured for BW gain, plasma coloration, and hematocrit whereas a subset of 184 animals was measured for intestinal lesion score, fecal oocyst count, blood parameters, and plasma protein content and composition. Most of the parameters measured were significantly affected by the challenge. Lesion scores for duodenum and jejunum (P < 0.001), oocyst count (P < 0.05), plasma coloration for the optical density values between 450 and 490 nm (P < 0.001), albumin (P < 0.001), α1-globulin (P < 0.01), α2-globulin (P < 0.001), α3-globulin (P < 0.01), and β2-globulin (P < 0.001) were the most strongly affected parameters and expressed the greatest levels of variation. Plasma protein profiles proved to be a new, reliable parameter for measuring response to Eimeria maxima. Prediction of intestinal lesion score and fecal oocyst

  20. Investigating the zonal wind response to SST warming using transient ensemble AGCM experiments

    NASA Astrophysics Data System (ADS)

    Palipane, Erool; Lu, Jian; Staten, Paul; Chen, Gang; Schneider, Edwin K.

    2017-01-01

    The response of the atmospheric circulation to greenhouse gas-induced SST warming is investigated using large ensemble experimen