Science.gov

Sample records for unpredictable environmental conditions

  1. Maternal response to environmental unpredictability.

    PubMed

    Barbosa, Miguel; Lopes, Isabel; Venâncio, Catia; Janeiro, Maria João; Morrisey, Michael Blair; Soares, Amadeu M V M

    2015-10-01

    Mothers are expected to use environmental cues to modify maternal investment to optimize their fitness. However, when the environment varies unpredictably, cues may not be an accurate proxy of future conditions. Under such circumstances, selection favors a diversifying maternal investment strategy. While there is evidence that the environment is becoming more uncertain, the extent to which mothers are able to respond to this unpredictability is generally unknown. In this study, we test the hypothesis that Daphnia magna increase the variance in maternal investment in response to unpredictable variation in temperature consistent with global change predictions. We detected significant variability across temperature treatments in brood size, neonate size at birth, and time between broods. The estimated variability within-brood size was higher (albeit not statistically significant) in mothers reared in unpredictable temperature conditions. We also detected a cross-generational effect with the temperature history of mothers modulating the phenotypic response of F1's. Notably, our results diverged from the prediction that increased variability poses a greater risk to organisms than changes in mean temperature. Increased unpredictability in temperature had negligible effects on fitness-correlated traits. Mothers in the unpredictable treatment, survived as long, and produced as many F1's during lifetime as those produced in the most fecund treatment. Further, increased unpredictability in temperature did not affect the probability of survival of F1's. Collectively, we provide evidence that daphnia respond effectively to thermal unpredictability. But rather than increasing the variance in maternal investment, daphnia respond to uncertainty by being a jack of all temperatures, master of none. Importantly, our study highlights the essential need to examine changes in variances rather than merely on means, when investigating maternal responses. PMID:26668723

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed

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

    2015-01-01

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

  4. The Effects of Feeding Unpredictability and Classical Conditioning on Pre-Release Training of White-Lipped Peccary (Mammalia, Tayassuidae)

    PubMed Central

    Nogueira, Selene S. C.; Abreu, Shauana A.; Peregrino, Helderes; Nogueira-Filho, Sérgio L. G.

    2014-01-01

    Some authors have suggested that environmental unpredictability, accompanied by some sort of signal for behavioral conditioning, can boost activity or foster exploratory behavior, which may increase post-release success in re-introduction programs. Thus, using white-lipped peccary (Tayassu pecari), a vulnerable Neotropical species, as a model, we evaluated an unpredictable feeding schedule. Associating this with the effect of classical conditioning on behavioral activities, we assessed the inclusion of this approach in pre-release training protocols. The experimental design comprised predictable feeding phases (control phases: C1, C2 and C3) and unpredictable feeding phases (U1- signaled and U2- non-signaled). The animals explored more during the signaled and non-signaled unpredictable phases and during the second control phase (C2) than during the other two predictable phases (C1 and C3). The peccaries also spent less time feeding during the signaled unpredictable phase (U1) and the following control phase (C2) than during the other phases. Moreover, they spent more time in aggressive encounters during U1 than the other experimental phases. However, the animals did not show differences in the time they spent on affiliative interactions or in the body weight change during the different phases. The signaled unpredictability, besides improving foraging behavior, showing a prolonged effect on the next control phase (C2), also increased the competition for food. The signaled feeding unpredictability schedule, mimicking wild conditions by eliciting the expression of naturalistic behaviors in pre-release training, may be essential to fully prepare them for survival in the wild. PMID:24475072

  5. A New Tool for Assessing Context Conditioning Induced by US-Unpredictability in Humans: The Martians Task Restyled

    ERIC Educational Resources Information Center

    Meulders, Ann; Vervliet, Bram; Vansteenwegen, Debora; Hermans, Dirk; Baeyens, Frank

    2011-01-01

    Unpredictability of an unconditioned stimulus (US) typically produces context conditioning in animals and humans. We modified the Martians task--a computer game measuring learning of Pavlovian associations through conditioned suppression--for assessing context conditioning in humans. One between-subjects and one within-subjects study are reported.…

  6. Diet and social conditions during sexual maturation have unpredictable influences on female life history trade-offs.

    PubMed

    Barrett, E L B; Moore, A J; Moore, P J

    2009-03-01

    The trade-off between gametes and soma is central to life history evolution. Oosorption has been proposed as a mechanism by which females can redirect nutrients invested in oocytes into survival when conditions for reproduction are poor. Although positive correlations between oocyte degradation and lifespan have been documented in oviparous insects, the adaptive significance of this process in species with more complex reproductive biology has not been explored. Further, environmental condition is a multivariate state, and combinations of environmental stresses may interact in unpredictable ways. Previous work on the ovoviviparous cockroach, Nauphoeta cinerea, revealed that females manipulated to mate late relative to sexual maturation experience age-related loss in fecundity because of loss of viable oocytes via apoptosis. This loss in fecundity is correlated with a reduction in female mate choice. Food deprivation while mating is delayed further increases levels of oocyte apoptosis, but the relationship between starvation-induced apoptosis and life history are unknown. To investigate this, virgin females were either fed or starved from eclosion until provided with a mate at a time known to be suboptimal for fertility. Following mating, females were fed for the duration of their lifespan. We measured lifetime reproductive performance. Contrary to predictions, under conditions of delayed mating opportunity, starved females had greater fecundity, gave birth to more high-quality offspring and had increased longevity compared with that of fed females. We suggest that understanding proximal mechanisms underlying life history trade-offs, including the function of oocyte apoptosis, and how these mechanisms respond to varied environmental conditions is critical. PMID:19170814

  7. Apomorphine induced conditioned place preference and sensitization is greater in rats exposed to unpredictable chronic mild stress.

    PubMed

    Kanwal, Sumera; Ikram, Huma; Farhan, Muhammad; Haleem, Darakhshan Jabeen

    2015-11-01

    CNS stimulants are the class of the drugs that may be used to get relief from depression. Apomorphine is a D1 and D2 receptor agonist with a CNS stimulatory effect used for the treatment of Parkinson's disease is also abused. Although many drugs of abuse produce tolerance and dependence. Long term use of pshycostimulants produce reverse tolerance described as sensitization. These drugs also have a number of other beneficial effects but their therapeutic use is limited because of abuse potential. Conditioned place preference (CPP) test is used to monitor the reinforcing effect of drugs of abuse. Stress is an important factor that precipitates and potentiates addictive effects of different drugs of abuse. The present study was designed to investigate the addictive effect of apomorphine (1mg/kg) in rats previously exposed to repeated unpredictable chronic mild stress for 10 days (animal model of depression). Results from present study illustrate that unpredictable chronic mild stress potentiates the reinforcing effects of apomorphine as the number of entries and the time spent in the CPP compartment associated with drug administration is increased. Motor activity was taken as a parameter for behavioral sensitization which is induced by repeated administration of apomorphine, monitored as the number of cage crossings in light compartment of the CPP apparatus, also increased. PMID:26639488

  8. Intestinal pseudo-obstruction: An uncommon condition with heterogeneous etiology and unpredictable outcome

    PubMed Central

    Georgescu, Eugen Florin; Vasile, Ion; Ionescu, Reanina

    2008-01-01

    Intestinal pseudo-obstruction (IPO) either acute or chronic is a condition including features of intestinal ileus in absence of mechanical obstruction. Our paper presents such a rare case of idiopathic IPO in a 53-year-old male patient with recurrent episodes of pseudo-obstruction, which were successfully resolved by anticholinesterase agents, motilin agonists or colonic decompression. However, the patient finally underwent total colectomy. Huge colonic dilatation was identified intraoperatively, while histology showed a neuropathic variant of chronic intestinal pseudo-obstruction. Etiologic mechanisms and current therapeutic methods are reviewed in this paper, which concludes that IPO is a condition in which conservative treatment usually fails. Total colectomy with ileoanal pouch may be the only solution in these situations. PMID:18240359

  9. Ingestion of environmentally contaminated Lake Ontario salmon by laboratory rats increases avoidance of unpredictable aversive nonreward and mild electric shock

    SciTech Connect

    Daly, H.B.; Hertzler, D.R.; Sargent, D.M. )

    1989-12-01

    To determine what behavioral changes are caused by consumption of Lake Ontario salmon, a 30% diet of Lake Ontario or control Pacific Ocean salmon was fed to rats for 20 days. In Experiments 1 and 2 (preference-for-predictability E-maze test), rats fed Lake Ontario salmon developed a preference for predictable food rewards more quickly than did the control rats. In Experiments 3 (passive avoidance) and 4 (conditioned suppression), rats fed Lake Ontario salmon suppressed responding to food far more after the introduction of mild electric shocks than did control rats. All results supported the hypothesis that ingestion of Lake Ontario salmon, contaminated with polychlorinated biphenyls, mercury, lead, etc., increases the reactivity of rats to aversive events. The results were successfully simulated by DMOD, a mathematical model of learning, using the assumption that rats fed Lake Ontario salmon find unpredictable nonreward and mild shock more aversive.

  10. Strategic foresight: how planning for the unpredictable can improve environmental decision-making.

    PubMed

    Cook, Carly N; Inayatullah, Sohail; Burgman, Mark A; Sutherland, William J; Wintle, Brendan A

    2014-09-01

    Advanced warning of potential new opportunities and threats related to biodiversity allows decision-makers to act strategically to maximize benefits or minimize costs. Strategic foresight explores possible futures, their consequences for decisions, and the actions that promote more desirable futures. Foresight tools, such as horizon scanning and scenario planning, are increasingly used by governments and business for long-term strategic planning and capacity building. These tools are now being applied in ecology, although generally not as part of a comprehensive foresight strategy. We highlight several ways foresight could play a more significant role in environmental decisions by: monitoring existing problems, highlighting emerging threats, identifying promising new opportunities, testing the resilience of policies, and defining a research agenda. PMID:25097098

  11. Movement - unpredictable or jerky

    MedlinePLUS

    ... Anti-cardiolipin antibody syndrome Benign hereditary chorea (a rare inherited condition) Disorders of calcium, glucose, or sodium ... medicines such as antipsychotic drugs) Thyroid disease Other rare disorders

  12. Friction causing unpredictability

    NASA Astrophysics Data System (ADS)

    Oldham, Joshua; Weigert, Stefan

    2016-03-01

    We study the effect of friction on the dynamics of a classical point particle in a one-dimensional double-well potential. It turns out that finite uncertainty in the initial conditions of the particle may prevent us from reliably predicting the well in which the particle will come to rest. This difficulty—to make reliable long-term predictions—originates from the layered structure of phase-space regions sending the particle to the left and the right well, respectively. Similar structures are known to arise in models used, for example, to described the tossing of a coin where friction is, however, not the root cause of the phenomenon.

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

    NASA Technical Reports Server (NTRS)

    Dragonette, Richard A.; Suter, Joseph J.

    1992-01-01

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

  14. Criticality and unpredictability in macroevolution

    NASA Astrophysics Data System (ADS)

    Soléand, Ricard V.; Manrubia, Susanna C.

    1997-04-01

    A recently presented model of large-scale evolution exhibiting self-organized criticality is explored from the dynamical point of view. It is shown that the system approaches the critical state in an anomalous way, with a dynamical exponent z=0. At the same time, the complexity of the interactions among species increases, leading to higher unpredictability. The dynamic evolution is able to generate phylogenetic fractal trees with dimension close to the one obtained from real taxonomy. Some analytic results are presented and an interesting interpretation of the macroevolutionary process is suggested.

  15. Dynamic photosynthesis in different environmental conditions.

    PubMed

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

    2015-05-01

    Incident irradiance on plant leaves often fluctuates, causing dynamic photosynthesis. Whereas steady-state photosynthetic responses to environmental factors have been extensively studied, knowledge of dynamic modulation of photosynthesis remains scarce and scattered. This review addresses this discrepancy by summarizing available data and identifying the research questions necessary to advance our understanding of interactions between environmental factors and dynamic behaviour of photosynthesis using a mechanistic framework. Firstly, dynamic photosynthesis is separated into sub-processes related to proton and electron transport, non-photochemical quenching, control of metabolite flux through the Calvin cycle (activation states of Rubisco and RuBP regeneration, and post-illumination metabolite turnover), and control of CO? supply to Rubisco (stomatal and mesophyll conductance changes). Secondly, the modulation of dynamic photosynthesis and its sub-processes by environmental factors is described. Increases in ambient CO? concentration and temperature (up to ~35°C) enhance rates of photosynthetic induction and decrease its loss, facilitating more efficient dynamic photosynthesis. Depending on the sensitivity of stomatal conductance, dynamic photosynthesis may additionally be modulated by air humidity. Major knowledge gaps exist regarding environmental modulation of loss of photosynthetic induction, dynamic changes in mesophyll conductance, and the extent of limitations imposed by stomatal conductance for different species and environmental conditions. The study of mutants or genetic transformants for specific processes under various environmental conditions could provide significant progress in understanding the control of dynamic photosynthesis. PMID:25324402

  16. Environmental Conditions in Kentucky's Penal Institutions

    ERIC Educational Resources Information Center

    Bell, Irving

    1974-01-01

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

  17. Environmental Conditions in Kentucky's Penal Institutions

    ERIC Educational Resources Information Center

    Bell, Irving

    1974-01-01

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

  18. The effect of unpredictable early childhood environments on parenting in adulthood.

    PubMed

    Szepsenwol, Ohad; Simpson, Jeffry A; Griskevicius, Vladas; Raby, K Lee

    2015-12-01

    Life history theory suggests that individual differences in parenting are partially rooted in environmental conditions experienced early in life. Whereas certain conditions should promote increased investment in parenting, unpredictable and/or harsh environments should promote decreased investment in parenting, especially in men. We tested this hypothesis in 3 studies. In Study 1a, we conducted analyses on 112 parents taking part in the Minnesota Longitudinal Study of Risk and Adaptation (MLSRA), all of whom have been continuously studied starting before they were born. Parenting orientations were assessed at age 32 via an interview. Findings showed that experiencing more unpredictability at ages 0-4 (i.e., frequent changes in parental employment status, cohabitation status, and residence) prospectively forecasted more negative parenting orientations among men, but not women. This effect was serially mediated by lower early maternal supportive presence measured at ages 0-4 and insecure attachment assessed at ages 19 and 26. In Study 1b, we replicated these findings on 96 parents from the MLSRA using behavioral observations of their parental supportive presence. In Study 2, we replicated the effect of early-life unpredictability on men's parenting orientations with a sample of 435 parents. This effect was mediated by adult attachment anxiety and avoidance. Across all studies, greater early-life harshness (low socioeconomic status [SES]) did not predict adult parenting outcomes. These findings suggest that greater early-life unpredictability may be conveyed to children through less supportive parenting, which results in insecure attachment representations in adulthood. Among men, this process culminates in less positive adult parenting orientations and less supportive parenting. PMID:26461797

  19. Certifying Unpredictable Randomness from Quantum Nonlocality

    NASA Astrophysics Data System (ADS)

    Bierhorst, Peter

    2015-03-01

    A device-independent quantum randomness protocol takes an initial random seed as input and then expands it in to a longer random string. It has been proven that if the initial random seed is trusted to be unpredictable, then the longer output string can also be certified to be unpredictable by an experimental violation of Bell's inequality. It has furthermore been argued that the initial random seed may not need to be truly unpredictable, but only uncorrelated to specific parts of the Bell experiment. In this work, we demonstrate rigorously that this is indeed true, under assumptions related to ``no superdeterminism/no conspiracy'' concepts along with the no-signaling assumption. So if we assume that superluminal signaling is impossible, then a loophole-free test of Bell's inequality would be able to generate provably unpredictable randomness from an input source of (potentially predictable) classical randomness.

  20. Unpredictability and the transmission of numbers

    NASA Astrophysics Data System (ADS)

    Myers, John M.; Madjid, F. Hadi

    2015-08-01

    Curiously overlooked in physics is its dependence on the transmission of numbers. For example, the transmission of numerical clock readings is implicit in the concept of a coordinate system. The transmission of numbers and other logical distinctions is often achieved over a computer-mediated communications network in the face of an unpredictable environment. By unpredictable we mean something stronger than the spread of probabilities over given possible outcomes, namely an opening to unforeseeable possibilities. Unpredictability, until now overlooked in theoretical physics, makes the transmission of numbers interesting. Based on recent proofs within quantum theory that provide a theoretical foundation to unpredictability, here we show how regularities in physics rest on a background of channels over which numbers are transmitted. As is known to engineers of digital communications, numerical transmissions depend on coordination reminiscent of the cycle of throwing and catching by players tossing a ball back and forth. In digital communications, the players are computers, and the required coordination involves unpredictably adjusting "live clocks" that step these computers through phases of a cycle. We show how this phasing, which we call logical synchronization, constrains number-carrying networks, and, if a spacetime manifold in invoked, put "stripes" on spacetime. Via its logically synchronized channels, a network of live clocks serves as a reference against which to locate events. Such a network in any case underpins a coordinate frame, and in some cases the direct use of a network can be tailored to investigate an unpredictable environment. Examples include explorations of gravitational variations near Earth.

  1. Anxiety sensitivity and the anticipation of predictable and unpredictable threat: Evidence from the startle response and event-related potentials.

    PubMed

    Nelson, Brady D; Hodges, Allie; Hajcak, Greg; Shankman, Stewart A

    2015-06-01

    There is growing evidence that heightened sensitivity to unpredictable threat is a core mechanism of dysfunction in anxiety disorders. However, it is unclear whether anxiety sensitivity is also associated with sensitivity to unpredictable threat. In the present study, 131 participants completed the Anxiety Sensitivity Index-3, which includes physical concerns (PC), social concerns (SC), and cognitive concerns (CC) subscales, and a predictable vs. unpredictable threat-of-shock task. Startle eyeblink and ERP responses (N100, P300) to the acoustic startle probes were measured during the task. PC and CC were associated with heightened and attenuated, respectively, startle for the unpredictable (but not predictable) condition. CC were also associated with attenuated probe N100 for the unpredictable condition only, and PC were associated with increased P300 suppression across the predictable and unpredictable conditions. This study provides novel evidence that the different anxiety sensitivity dimensions demonstrate unique relationships with the RDoC domains "acute" and "potential" threat. PMID:26005838

  2. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  3. Environmental conditions and reproductive health outcomes

    EPA Science Inventory

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

  4. Resource unpredictability promotes species diversity and coexistence in an avian scavenger guild: a field experiment.

    PubMed

    Cortés-Avizanda, A; Jovani, R; Carrete, M; Donázar, J A

    2012-12-01

    Chance per se plays a key role in ecology and evolution, e.g., genetic mutation, resource spatiotemporal unpredictability. In community ecology, chance is recognized as a key factor in community assemblage, but less is known about its role in intraguild processes leading to species coexistence. Here we study the relevance of resource unpredictability per se as a promoter of intraguild positive interspecific interactions and as a biodiversity enhancer in an Old World avian scavenger guild, which has evolved to feed upon spatially and temporally unpredictable resources, i.e., carcasses. We performed a large-scale field experiment in which 58 carcasses were disposed of and observed until complete consumption, either in continuously active supplementary feeding stations (predictable carcasses) or disposed of at random in the field (unpredictable carcasses). Richness of scavenger species was similar at unpredictable and predictable carcasses, but their relative abundances were highly uneven at predictable carcasses leading to higher scavenger diversity (Shannon index) at unpredictable carcasses. Facilitatory interspecific processes only occurred at unpredictable resources but were disrupted in predictable conditions because the dominant specialist species (in our case, the Griffon Vulture Gyps fulvus) arrived earlier and in larger numbers, monopolizing the resource. Small, endangered scavengers congregated at supplementary feeding stations but profited less compared to unpredictable carcasses, suggesting that they could constitute an ecological trap. Our findings offer new insights into the relevance of unpredictability of trophic resources in promoting both positive facilitatory interspecific interactions and species diversity and thus maintaining the function of guilds. Finally, the preservation of randomness in resource availability and the processes associated with its exploitation should be a major goal of conservation strategies aimed to preserve scavenger guilds evolved under naturally unpredictable trophic resources. PMID:23431588

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

    PubMed

    Cardoso, Paulo; Freitas, Rosa; Figueira, Etelvina

    2015-01-01

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

  6. Eliminating Unpredictable Variation through Iterated Learning

    ERIC Educational Resources Information Center

    Smith, Kenny; Wonnacott, Elizabeth

    2010-01-01

    Human languages may be shaped not only by the (individual psychological) processes of language acquisition, but also by population-level processes arising from repeated language learning and use. One prevalent feature of natural languages is that they avoid unpredictable variation. The current work explores whether linguistic predictability might…

  7. Eliminating Unpredictable Variation through Iterated Learning

    ERIC Educational Resources Information Center

    Smith, Kenny; Wonnacott, Elizabeth

    2010-01-01

    Human languages may be shaped not only by the (individual psychological) processes of language acquisition, but also by population-level processes arising from repeated language learning and use. One prevalent feature of natural languages is that they avoid unpredictable variation. The current work explores whether linguistic predictability might…

  8. Crops Models for Varying Environmental Conditions

    NASA Technical Reports Server (NTRS)

    Jones, Harry; Cavazzoni, James; Keas, Paul

    2001-01-01

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

  9. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

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

  10. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

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

  11. 10 CFR 50.36b - Environmental conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Environmental conditions. 50.36b Section 50.36b Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES Applications for... § 50.36b Environmental conditions. (a) Each construction permit under this part, each early site...

  12. Environmental enrichment reduces impulsivity during appetitive conditioning.

    PubMed

    Wood, David A; Siegel, Amy K; Rebec, George V

    2006-06-15

    Although environmental enrichment is presumed to enhance learning, appetitive behavior may also be altered by this experience: anticipatory responding for sucrose is reduced in environmentally enriched (EE) rats [van der Harst, J.E., Baars, A.M. and Spruijt, B.M. Standard housed rats are more sensitive to rewards than enriched housed rats as reflected by their anticipatory behaviour. Behav Brain Res 2003;142:151-156]. To assess the impact of differential environmental experience on learning and appetitive behavior, we trained 17 EE and socially isolated (SI) rats in a three-phase, operant-shaping procedure for sucrose reinforcement. In phase one, a feeder cue was paired with sucrose availability. In phase two, a nose poke to either one of two lit holes on the opposing wall activated the feeder cue. In phase three, the feeder cue was elicited by a poke to a single lit hole. While acquisition rates in phase one and phase two were similar, EE animals reached phase-three criteria [completion of 100 trials in 45 min and 15 or fewer bad pokes] faster than SI animals. These two groups showed similar session completion rates, reinforced and non-reinforced licking responses, and overall behavioral activity during phase three acquisition; however, SI rats performed more bad pokes (responses to the non-lit hole after nose-poke cue onset) and intertrial interval (ITI) pokes during this training period. Because all ITI (and presumably many bad) pokes were initiated before onset of nose-poke cue, this difference indicates greater anticipatory responding in SI animals. This experience-dependent alteration in appetitive behavior may explain, in part, the tendency of SI rats to show attenuated learning rates in appetitive contexts in which complex contingencies exist. PMID:16678224

  13. Lunar Polar Environmental Testing: Regolith Simulant Conditioning

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie Elise

    2014-01-01

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

  14. Management of Cattle Exposed to Adverse Environmental Conditions.

    PubMed

    Mader, Terry L; Griffin, Dee

    2015-07-01

    During periods of adverse weather, optimum conditions for animal comfort and performance are compromised. Use of alternative supplementation programs need to be considered for livestock challenged by adverse environmental conditions. Use of additional water for consumption and cooling, shade, and/or alternative management strategies need to be considered to help livestock cope with heat stress. For animals reared outside during winter, strategies that increase animal space and environmental buffers need to be used to minimize effects of mud, wet conditions, and windchill. There are ample opportunities for livestock producers to enhance animal welfare and minimize the impact of environmental stress. PMID:26139190

  15. ENVIRONMENTALLY FRIENDLIER ORGANIC TRANSFORMATIONS ON MINERAL SUPPORTS UNDER NONTRADITIONAL CONDITIONS

    EPA Science Inventory

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

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

    USGS Publications Warehouse

    Waythomas, C.F.

    1994-01-01

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

  17. Beyond Cumulative Risk: Distinguishing Harshness and Unpredictability as Determinants of Parenting and Early Life History Strategy

    ERIC Educational Resources Information Center

    Belsky, Jay; Schlomer, Gabriel L.; Ellis, Bruce J.

    2012-01-01

    Drawing on life history theory, Ellis and associates' (2009) recent across- and within-species analysis of ecological effects on reproductive development highlighted two fundamental dimensions of environmental variation and influence: harshness and unpredictability. To evaluate the unique contributions of these factors, the authors of present…

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

    PubMed Central

    Korpe, Poonum S.; Petri, William A.

    2012-01-01

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

  19. Displacing Unpredictable Nulls in Antenna Radiation Patterns

    NASA Technical Reports Server (NTRS)

    Lux, James; Schaefer, Mark

    2005-01-01

    A method of maintaining radio communication despite the emergence of unpredictable fades and nulls in the radiation pattern of an antenna has been proposed. The method was originally intended to be applied in the design and operation of a radio antenna aboard a robotic exploratory vehicle on a remote planet during communication with a spacecraft in orbit around the planet. The method could also be applied in similar terrestrial situations for example, radio communication between two ground vehicles or between a ground vehicle and an aircraft or spacecraft. The method is conceptually simple, is readily adaptable to diverse situations, and can be implemented without adding greatly to the weight, cost, power demand, or complexity of a system to which it may be applied. The unpredictable fades and nulls in an antenna radiation pattern arise because of electromagnetic interactions between the antenna and other objects within the near field of the antenna (basically, objects within a distance of a few wavelengths). These objects can include general vehicle components, masts, robotic arms, other antennas, the ground, and nearby terrain features. Figure 1 presents representative plots of signal strength versus time during a typical pass of a spacecraft or aircraft through the far field of such an antenna, showing typical nulls and fades caused by nearby objects. The traditional approach to ensuring reliability of communication in the presence of deep fades calls for increasing the effective transmitter power and/or reducing the receiver noise figure at the affected ground vehicle, possibly in combination with appropriate redesign of the equipment at the spacecraft or aircraft end of the communication link. These solutions can be expensive and/or risky and, depending on the application, can add significantly to weight, cost, and power demand. The proposed method entails none of these disadvantages.

  20. Preference for unpredictable food rewards occurs with high proportion of reinforced trials or alcohol if rewards are not delayed.

    PubMed

    Daly, H B

    1989-01-01

    Organisms typically prefer situations where reward and nonreward are predictable rather than unpredictable. Although many theories can account for this result (e.g., information theory and delay-reduction theory), a recently developed mathematical model (DMOD) also predicts that subjects prefer the unpredictable reward situation under conditions that substantially decrease aversiveness of unpredictable nonreward (Daly & Daly, 1982). Because a high proportion of reinforced trials (lenient schedule) and alcohol injections decrease aversive conditioning, these variables were tested with rats in five E-maze experiments. A choice to one side of the maze resulted in a stimulus uncorrelated with reward outcome (unpredictable situation). A choice to the other side resulted in stimuli correlated with reward and nonreward (predictable situation). The stimuli were not visible until after the choice was made. A lenient reinforcement schedule resulted in preference for the unpredictable reward situation if rewards were not delayed. Alcohol resulted in preference for the unpredictable reward situation if a medium five-pellet reward was given. A lenient reinforcement schedule combined with an alcohol injection resulted in faster acquisition of the preference for the unpredictable reward situation than did a lenient schedule combined with a saline control injection. These results pose a major challenge to most theories, yet were predicted by DMOD. PMID:2926334

  1. Classical conditions of environmental cues to cigarette smoking.

    PubMed

    Lazev, A B; Herzog, T A; Brandon, T H

    1999-02-01

    Smoking-related cues tend to produce urges and cardiac responses in smokers. This reactivity has been assumed to reflect prior classical conditioning. However, little direct evidence exists supporting the notion that environmental cues can be classically conditioned to cigarette smoking. In this study, 8 smokers received 22 daily trials during which 2 cue complexes (comprising visual, olfactory, and auditory stimuli) were paired with smoking (CS+ trials) and not smoking (CS- trials). Reactivity to the environmental cues, as measured by self-report of urge and pulse rate, increased across CS+ trials, diverging from responses in the CS- trials. Reactivity was stronger among light smokers and those who verbalized awareness of smoking contingencies. Findings indicate that environmental cues can be classically conditioned to smoking. PMID:10036610

  2. Stress in Atlantic salmon: response to unpredictable chronic stress.

    PubMed

    Madaro, Angelico; Olsen, Rolf E; Kristiansen, Tore S; Ebbesson, Lars O E; Nilsen, Tom O; Flik, Gert; Gorissen, Marnix

    2015-08-01

    Combinations of stressors occur regularly throughout an animal's life, especially in agriculture and aquaculture settings. If an animal fails to acclimate to these stressors, stress becomes chronic, and a condition of allostatic overload arises with negative results for animal welfare. In the current study, we describe effects of exposing Atlantic salmon parr to an unpredictable chronic stressor (UCS) paradigm for 3?weeks. The paradigm involves exposure of fish to seven unpredictable stressors three times a day. At the end of the trial, experimental and control fish were challenged with yet another novel stressor and sampled before and 1?h after that challenge. Plasma cortisol decreased steadily over time in stressed fish, indicative of exhaustion of the endocrine stress axis. This was confirmed by a lower cortisol response to the novel stressor at the end of the stress period in chronically stressed fish compared with the control group. In the preoptic area (POA) and pituitary gland, chronic stress resulted in decreased gene expression of 11?hsd2, gr1 and gr2 in the POA and increased expression of those genes in the pituitary gland. POA crf expression and pituitary expression of pomcs and mr increased, whereas interrenal gene expression was unaffected. Exposure to the novel stressor had no effect on POA and interrenal gene expression. In the pituitary, crfr1, pomcs, 11?hsd2, grs and mr were down-regulated. In summary, our results provide a novel overview of the dynamic changes that occur at every level of the hypothalamic-pituitary gland-interrenal gland (HPI) axis as a result of chronic stress in Atlantic salmon. PMID:26056242

  3. Ceramic production during changing environmental/climatic conditions

    NASA Astrophysics Data System (ADS)

    Oestreich, Daniela B.; Glasmacher, Ulrich A.

    2015-04-01

    Ceramics, with regard to their status as largely everlasting everyday object as well as on the basis of their chronological sensitivity, reflect despite their simplicity the technological level of a culture and therefore also, directly or indirectly, the adaptability of a culture with respect to environmental and/or climatic changes. For that reason the question arises, if it is possible to identify changes in production techniques and raw material sources for ceramic production, as a response to environmental change, e.g. climate change. This paper will present results of a research about Paracas Culture (800 - 200 BC), southern Peru. Through several investigations (e.g. Schittek et al., 2014; Eitel and Mächtle, 2009) it is well known that during Paracas period changes in climate and environmental conditions take place. As a consequence, settlement patterns shifted several times through the various stages of Paracas time. Ceramics from three different sites (Jauranga, Cutamalla, Collanco) and temporal phases of the Paracas period are detailed archaeometric, geochemical and mineralogical characterized, e.g. Raman spectroscopy, XRD, and ICP-MS analyses. The aim of this research is to resolve potential differences in the chemical composition of the Paracas ceramics in space and time and to compare the data with the data sets of pre-Columbian environmental conditions. Thus influences of changing environmental conditions on human societies and their cultural conditions will be discussed. References Eitel, B. and Mächtle, B. 2009. Man and Environment in the eastern Atacama Desert (Southern Peru): Holocene climate changes and their impact on pre-Columbian cultures. In: Reindel, M. & Wagner, G. A. (eds.) New Technologies for Archaeology. Berlin Heidelberg: Springer-Verlag. Schittek, K., Mächtle, B., Schäbitz, F., Forbriger, M., Wennrich, V., Reindel, M., and Eitel, B.. Holocene environmental changes in the highlands of the southern Peruvian Andes (14° S) and their impact on pre-Columbian cultures, Clim. Past Discuss., 10, 1707-1746.

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

    NASA Astrophysics Data System (ADS)

    Perry, Mark Charles

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

  5. Environmental Conditions for Space Flight Hardware: A Survey

    NASA Technical Reports Server (NTRS)

    Plante, Jeannette; Lee, Brandon

    2005-01-01

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

  6. Uncontrollable and unpredictable stress interacts with subclinical depression and anxiety scores in determining anxiety response.

    PubMed

    Havranek, Michael M; Bolliger, Bianca; Roos, Sophie; Pryce, Christopher R; Quednow, Boris B; Seifritz, Erich

    2016-01-01

    According to learned helplessness theory, uncontrollable stress is assumed to be a critical etiological factor in the pathogenesis of depression. In contrast, unpredictability of stressors is assumed to facilitate the development of sustained anxiety. Despite the frequent co-morbidity of depression and anxiety disorders, these two factors have rarely been studied simultaneously in humans. Therefore, we investigated whether there are interaction effects of uncontrollability and unpredictability on anxiety response in healthy participants. Seventy-nine healthy participants performed a visual dot probe task with emotional faces, while receiving mild electrical shocks in four different conditions (2?×?2 factorial design). In (un)controllable conditions, participants were (not) able to attenuate shock intensity. In (un)predictable conditions, participants were (not) able to anticipate shock occurrence. Before the experiment, participants' subclinical depression and anxiety scores were measured using the Beck Depression and Anxiety Inventories (BDI/BAI). During the experiment, continuous skin conductance and self-reported state anxiety were assessed and attentional biases towards angry faces were calculated. As expected, participants showed greater anxiety in uncontrollable compared to controllable and in unpredictable compared to predictable conditions. Additionally, anxiety decreased within the test sessions in participants with low BDI/BAI scores but not in participants with higher BDI/BAI scores. Most importantly, controllability and predictability interacted with each other and with BDI/BAI scores with regard to anxiety. Our results provide evidence that uncontrollability and unpredictability of stressors not only have separate but also interaction effects on several anxiety measures in susceptible individuals and may provide insights into the psychological mechanisms underlying a depressive/anxiety co-morbidity. PMID:26669536

  7. Effects of Harsh and Unpredictable Environments in Adolescence on Development of Life History Strategies

    PubMed Central

    Figueredo, Aurelio José; Ellis, Bruce J.

    2010-01-01

    The National Longitudinal Study of Adolescent Health data were used to test predictions from life history theory. We hypothesized that (1) in young adulthood an emerging life history strategy would exist as a common factor underlying many life history traits (e.g., health, relationship stability, economic success), (2) both environmental harshness and unpredictability would account for unique variance in expression of adolescent and young adult life history strategies, and (3) adolescent life history traits would predict young adult life history strategy. These predictions were supported. The current findings suggest that the environmental parameters of harshness and unpredictability have concurrent effects on life history development in adolescence, as well as longitudinal effects into young adulthood. In addition, life history traits appear to be stable across developmental time from adolescence into young adulthood. PMID:20634914

  8. Environmental conditions influence tissue regeneration rates in scleractinian corals.

    PubMed

    Sabine, Alexis M; Smith, Tyler B; Williams, Dana E; Brandt, Marilyn E

    2015-06-15

    Natural and anthropogenic factors may influence corals' ability to recover from partial mortality. To examine how environmental conditions affect lesion healing, we assessed several water quality parameters and tissue regeneration rates in corals at six reefs around St. Thomas, US Virgin Islands. We hypothesized that sites closer to developed areas would have poor water quality due to proximity to anthropogenic stresses, which would impede tissue regeneration. We found that water flow and turbidity most strongly influenced lesion recovery rates. The most impacted site, with high turbidity and low flow, recovered almost three times slower than the least impacted site, with low turbidity, high flow, and low levels of anthropogenic disturbance. Our results illustrate that in addition to lesion-specific factors known to affect tissue regeneration, environmental conditions can also control corals' healing rates. Resource managers can use this information to protect low-flow, turbid nearshore reefs by minimizing sources of anthropogenic stress. PMID:25982415

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

    PubMed Central

    Burton, Tim; Metcalfe, Neil B.

    2014-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

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

  11. Alternative stable states explain unpredictable biological control of Salvinia molesta in Kakadu.

    PubMed

    Schooler, Shon S; Salau, Buck; Julien, Mic H; Ives, Anthony R

    2011-02-01

    Suppression of the invasive plant Salvinia molesta by the salvinia weevil is an iconic example of successful biological control. However, in the billabongs (oxbow lakes) of Kakadu National Park, Australia, control is fitful and incomplete. By fitting a process-based nonlinear model to thirteen-year data sets from four billabongs, here we show that incomplete control can be explained by alternative stable states--one state in which salvinia is suppressed and the other in which salvinia escapes weevil control. The shifts between states are associated with annual flooding events. In some years, high water flow reduces weevil populations, allowing the shift from a controlled to an uncontrolled state; in other years, benign conditions for weevils promote the return shift to the controlled state. In most described ecological examples, transitions between alternative stable states are relatively rare, facilitated by slow-moving environmental changes, such as accumulated nutrient loading or climate change. The billabongs of Kakadu give a different manifestation of alternative stable states that generate complex and seemingly unpredictable dynamics. Because shifts between alternative stable states are stochastic, they present a potential management strategy to maximize effective biological control: when the domain of attraction to the state of salvinia control is approached, augmentation of the weevil population or reduction of the salvinia biomass may allow the lower state to trap the system. PMID:21293376

  12. Lateralization and Gender Differences in the Dopaminergic Response to Unpredictable Reward in the Human Ventral Striatum

    PubMed Central

    Martin-Soelch, Chantal; Szczepanik, Joanna; Nugent, Allison; Barhaghi, Krystle; Rallis, Denise; Herscovitch, Peter; Carson, Richard E.; Drevets, Wayne C.

    2011-01-01

    Electrophysiological studies showed that mesostriatal dopamine (DA) neurons increase activity in response to unpredicted rewards. With respect to other functions of the mesostriatal dopaminergic system, dopamine’s actions show prominent laterality effects. Whether changes in DA transmission elicited by rewards also are lateralized, however, has not been investigated. Using [11C]raclopride-PET to assess the striatal DA response to unpredictable monetary rewards, we hypothesized that such rewards would induce an asymmetric reduction of [11C]raclopride binding in the ventral striatum, reflecting lateralization of endogenous dopamine release. In 24 healthy volunteers, differences in the regional D2/3 receptor binding potential (ΔBP) between an unpredictable reward condition and a sensorimotor control condition were measured using the bolus-plus-constant-infusion [11C]raclopride method. During the reward condition subjects randomly received monetary awards while performing a “slot-machine” task. The ΔBP between conditions was assessed in striatal regions-of-interest and compared between left and right sides. We found a significant condition × lateralization interaction in the ventral striatum. A significant reduction in binding potential (BPND) in the reward condition versus the control condition was found only in the right ventral striatum, and the ΔBP was greater in the right than the left ventral striatum. Unexpectedly, these laterality effects appeared to be partly accounted for by sex differences, as our data showed a significant bilateral BPND reduction in women, while in men the reduction reached significance only in the right ventral striatum. These data suggest that DA release in response to unpredictable reward is lateralized in the human ventral striatum, particularly in males. PMID:21453423

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

    PubMed Central

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

    2014-01-01

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

  14. Distinct state anxiety after predictable and unpredictable fear training in mice.

    PubMed

    Seidenbecher, Thomas; Remmes, Jasmin; Daldrup, Thiemo; Lesting, Jörg; Pape, Hans-Christian

    2016-05-01

    Sustained fear paradigms in rodents have been developed to monitor states of anxious apprehension and to model situations in patients suffering from long-lasting anxiety disorders. A recent report describes a fear conditioning paradigm, allowing distinction between phasic and sustained states of conditioned fear in non-restrained mice. However, so far no prospective studies have yet been conducted to elucidate whether induction of phasic or sustained fear can affect states of anxiety. Here, we used CS (conditioned stimulus) and US (unconditioned stimulus) pairing with predictable and unpredictable timing to induce phasic and sustained fear in mice. State anxiety during various fear response components was assessed using the elevated plus-maze test. Training with unpredictable CS-US timing resulted in CS-evoked sustained components of fear (freezing), while predictable CS-US timing resulted in rapid decline. Data suggested the influence of training procedure on state anxiety which is dependent on progression of conditioned fear during fear memory retrieval. Animals trained with unpredictable CS-US timing showed an unchanged high anxiety state throughout behavioral observation. In contrast, mice trained with predictable CS-US timing showed anxiolytic-like behavior 3min after CS onset, which was accompanied by a fast decline of the fear conditioned response (freezing). Further systematic studies are needed to validate the phasic/sustained fear model in rodents as translational model for anxiety disorders in humans. PMID:26876138

  15. Ecological Conditions Favoring Budding in Colonial Organisms under Environmental Disturbance

    PubMed Central

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

    2014-01-01

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

  16. Studying the relationship between on-farm environmental conditions and local meteorological station data during the summer.

    PubMed

    Shock, D A; LeBlanc, S J; Leslie, K E; Hand, K; Godkin, M A; Coe, J B; Kelton, D F

    2016-03-01

    High ambient heat and humidity have profound effects on the production, health, profitability, and welfare of dairy cattle. To describe the relationship between summer temperature and relative humidity in the barn and determine the appropriateness of using meteorological station data as a surrogate for on-farm environmental monitoring, a study was conducted on 48 farms in Ontario, Canada, over the summer (May through September) of 2013. Within-barn environmental conditions were recorded using remote data loggers. These values were compared with those of the closest official meteorological station. In addition, farm-level characteristics and heat-abatement strategies were recorded for each farm. Environmental readings within the barn were significantly higher than those of the closest meteorological station; however, this relationship varied greatly by herd. Daily temperature-humidity index (THI) values within the barn tended to be 1 unit higher than those of the closest meteorological station. Numerically, 1.5 times more mean daily THI readings were in excess of 68 (heat stress threshold for lactating dairy cows) in the barn, relative to the closest meteorological station. In addition, tiestalls, herds that were allowed access to pasture, and herds that had no permanent cooling strategy for their cows had the highest mean and maximum daily THI values. Minimum daily THI values were almost 4 units higher for tiestall relative to freestall herds. Overall, due to farm-specific and unpredictable variability in magnitude of environmental differences between on-farm and meteorological station readings, researchers attempting to study the effects of environment on dairy cows should not use readings from meteorological stations because these will often underestimate the level of heat stress to which cows are exposed. PMID:26778304

  17. Temperature and humidity environmental conditions in the VLTI

    NASA Astrophysics Data System (ADS)

    Puech, Florence; Lévêque, Samuel; Sarazin, Marc; Mathar, Richard J.

    2006-06-01

    Knowledge of the environmental conditions in the Very Large Telescope Interferometer (VLTI) is fundamental for assessing the performance of the scientific instruments and sub-systems of the VLTI, as well as for the calibration of measurement biases (e.g. in astrometry). Therefore, four temperature and humidity sensors were installed in the VLTI delay line tunnel and in the VLTI laboratory in September 2004. First results from the analysis of the long-term (18 months) humidity and temperature data measured by this network will be presented, along with a comparison of the temperatures monitored by the VLTI temperature sensors network and correlations with the external data of the Paranal weather station.

  18. A New Arbiter PUF for Enhancing Unpredictability on FPGA.

    PubMed

    Machida, Takanori; Yamamoto, Dai; Iwamoto, Mitsugu; Sakiyama, Kazuo

    2015-01-01

    In general, conventional Arbiter-based Physically Unclonable Functions (PUFs) generate responses with low unpredictability. The N-XOR Arbiter PUF, proposed in 2007, is a well-known technique for improving this unpredictability. In this paper, we propose a novel design for Arbiter PUF, called Double Arbiter PUF, to enhance the unpredictability on field programmable gate arrays (FPGAs), and we compare our design to conventional N-XOR Arbiter PUFs. One metric for judging the unpredictability of responses is to measure their tolerance to machine-learning attacks. Although our previous work showed the superiority of Double Arbiter PUFs regarding unpredictability, its details were not clarified. We evaluate the dependency on the number of training samples for machine learning, and we discuss the reason why Double Arbiter PUFs are more tolerant than the N-XOR Arbiter PUFs by evaluating intrachip variation. Further, the conventional Arbiter PUFs and proposed Double Arbiter PUFs are evaluated according to other metrics, namely, their uniqueness, randomness, and steadiness. We demonstrate that 3-1 Double Arbiter PUF archives the best performance overall. PMID:26491720

  19. A New Arbiter PUF for Enhancing Unpredictability on FPGA

    PubMed Central

    Machida, Takanori; Yamamoto, Dai; Iwamoto, Mitsugu; Sakiyama, Kazuo

    2015-01-01

    In general, conventional Arbiter-based Physically Unclonable Functions (PUFs) generate responses with low unpredictability. The N-XOR Arbiter PUF, proposed in 2007, is a well-known technique for improving this unpredictability. In this paper, we propose a novel design for Arbiter PUF, called Double Arbiter PUF, to enhance the unpredictability on field programmable gate arrays (FPGAs), and we compare our design to conventional N-XOR Arbiter PUFs. One metric for judging the unpredictability of responses is to measure their tolerance to machine-learning attacks. Although our previous work showed the superiority of Double Arbiter PUFs regarding unpredictability, its details were not clarified. We evaluate the dependency on the number of training samples for machine learning, and we discuss the reason why Double Arbiter PUFs are more tolerant than the N-XOR Arbiter PUFs by evaluating intrachip variation. Further, the conventional Arbiter PUFs and proposed Double Arbiter PUFs are evaluated according to other metrics, namely, their uniqueness, randomness, and steadiness. We demonstrate that 3-1 Double Arbiter PUF archives the best performance overall. PMID:26491720

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

    PubMed

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

    2015-09-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    PubMed

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

    2016-03-15

    Leaching of metals from cement under various environmental conditions was measured to evaluate their environmental safety. A cement product containing clinker, which was produced from cement kiln co-processing of hazardous wastes, was solidified and leaching of metals was characterized using the 8-period test. Concentrations and speciation of metals in cements were determined. Effects of ambient environment and particle size on leachability of metals and mineralogical phases of cement mortars were evaluated by use of XRD and SEM. Results indicated that metals in cements were leachable in various media in descending order of: sea water, groundwater and acid rain. Cr, Ni, As, Co and V were leached by simulated sea water, while Cu, Cd, Pb, Zn, Mn, Sb and Tl were not leached in simulated sea water, groundwater or acid rain. When exposed to simulated acid rain or groundwater, amounts of Cr, Ni, As and V leached was inversely proportional to particle size of cement mortar. According to the one-dimensional diffusion equation, Cr was most leachable and the cumulative leached mass was predicted to be 9.6 mg kg(-1) after 20 years. Results of this study are useful in predicting releases of metals from cement products containing ash and clinkers cement kiln co-processing of hazardous wastes, so that they can be safely applied in the environment. PMID:26802528

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

    SciTech Connect

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

    1996-04-01

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

  4. Effects of environmental conditions on latex degradation in aquatic systems.

    PubMed

    Lambert, Scott; Sinclair, Chris J; Bradley, Emma L; Boxall, Alistair B A

    2013-03-01

    Following use polymer materials may be released to the natural environment distributed to various environmental compartments and may undergo a variety of mechanical and chemical weathering processes. This study characterised the degradation of a latex polymer of different thicknesses under a range of environmental conditions in outdoor microcosms. Samples were immersed in either demineralised water, artificial freshwater and marine water media and exposed for a period of 200-250 days with exposure starting at different times of the year. Effects of pH, agitation and the exclusion of light on degradation were also studied. At the end of the exposure period, recovery of polymer material ? 1.6 ?m ranged from a low of 22.04% (± 16.35, for the freshwater treatment at pH5.5) to a high of 97.73% (± 0.38, for the exclusion of light treatment). The disappearance of the bulk material corresponded to an increase in nanoparticles and dissolved organic material in the test media. Modelled degradation kinetics were characterised by multi-phasic degradation patterns and the results indicated degradation rate is affected by light intensity and polymer thickness. Mass balance analysis indicates that losses of volatile materials to the air compartment may also be occurring. PMID:23384646

  5. Spectral Characterization of Phobos Analogues Under Simulated Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Donaldson Hanna, K. L.; Bowles, N. E.; Edwards, C. S.; Glotch, T. D.; Greenhagen, B. T.; Pieters, C. M.; Thomas, I.

    2014-12-01

    The surface of Phobos holds many keys for understanding its formation and evolution as well as the history and dynamics of the Mars-Phobos system. Visible to near infrared (VNIR) observations suggests that Phobos' surface is compositionally heterogeneous with 'redder' and 'bluer' units that both appear to be anhydrous in nature. Lunar highland spectra have been identified as spectral analogues for the 'redder' and 'bluer' units while thermally metamorphosed CI/CM chondrites, lab-heated carbonaceous chondrites and highly space weathered mafic mineral assemblages have been identified as the best analogues for the 'bluer' surface units. Additionally, thermal infrared emissivity spectra indicate that if Phobos' surface is optically mature it may be rich in feldspar, which is consistent with VNIR observations of Phobos' surface being spectrally similar to lunar highland spectra. While remote observations provide key insights into the composition and evolution of planetary surfaces, a fundamentally important component to any remote compositional analysis of planetary surfaces is laboratory measurements of well-characterized samples measured under the appropriate environmental conditions. The vacuum environment of airless bodies creates a steep thermal gradient in the upper hundreds of microns of regolith. Lab studies of particulate rocks and minerals as well as selected lunar soils under vacuum and lunar-like conditions have identified significant effects of this thermal gradient on thermal infrared (TIR) spectral measurements. However recent lab measurements of carbonaceous chondrites demonstrated that simulated asteroid conditions do not affect the resulting emissivity spectra to the degree observed in lunar soils and is highly dependent on composition. Such lab studies demonstrate the high sensitivity of TIR emissivity spectra to environmental conditions under which they are measured and indicate that the near surface environment of all airless bodies do not spectrally behave in similar ways. An initial set of TIR emissivity measurements of Phobos analogue materials will be made in the Simulated Lunar Environment chamber at the University of Oxford. These lab measurements will be characterized in an effort better understand how to interpret current and future TIR observations of Phobos.

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

    NASA Astrophysics Data System (ADS)

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

    2012-04-01

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

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

    PubMed

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

    2015-01-01

    Guanabara Bay is the second largest bay in the coast of Brazil, with an area of 384 km(2). In its surroundings live circa 16 million inhabitants, out of which 6 million live in Rio de Janeiro city, one of the largest cities of the country, and the host of the 2016 Olympic Games. Anthropogenic interference in Guanabara Bay area started early in the XVI century, but environmental impacts escalated from 1930, when this region underwent an industrialization process. Herein we present an overview of the current environmental and sanitary conditions of Guanabara Bay, a consequence of all these decades of impacts. We will focus on microbial communities, how they may affect higher trophic levels of the aquatic community and also human health. The anthropogenic impacts in the bay are flagged by heavy eutrophication and by the emergence of pathogenic microorganisms that are either carried by domestic and/or hospital waste (e.g., virus, KPC-producing bacteria, and fecal coliforms), or that proliferate in such conditions (e.g., vibrios). Antibiotic resistance genes are commonly found in metagenomes of Guanabara Bay planktonic microorganisms. Furthermore, eutrophication results in recurrent algal blooms, with signs of a shift toward flagellated, mixotrophic groups, including several potentially harmful species. A recent large-scale fish kill episode, and a long trend decrease in fish stocks also reflects the bay's degraded water quality. Although pollution of Guanabara Bay is not a recent problem, the hosting of the 2016 Olympic Games propelled the government to launch a series of plans to restore the bay's water quality. If all plans are fully implemented, the restoration of Guanabara Bay and its shores may be one of the best legacies of the Olympic Games in Rio de Janeiro. PMID:26635734

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

    PubMed Central

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

    2015-01-01

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

  9. [Individual adaptation strategy under extreme environmental conditions in humans].

    PubMed

    Soroko, S I; Aldasheva, A A

    2012-01-01

    Starting from the researches of I.M. Sechenov, I.P. Pavlov, A.A. Uchtomskii, the Russian psychophysiological school considers adaptation in connection with the biological and social origin of a man as the integrated, coordinated and self-controlled human organism's reaction to maintain the vital functions in the constantly changing environmental conditions. On the base of well-known systemic-dynamic methodology and scrutinizing the issue of man and environment interaction V.I. Medvedev added to the theory of man's adaptation the activity paradigm that enable to uncover the distinctive features of professional activities in various environment conditions. The theoretical and practical investigations based on the activity methodology gave the opportunity to find out the new principles of interaction between man and environment and on the strategy of adaptive behavior. From this investigations one could see that the main characteristic of interaction "man-environment" is that man represents proactive side, man simulate different adaptation strategies using both genetically-fixed and acquired mechanisms of adaptive behavior. PMID:23393785

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

    PubMed

    Rohrlack, Thomas; Haande, Sigrid; Molversmyr, Åge; Kyle, Marcia

    2015-01-01

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

  11. Leadership and Transformation in an Environment of Unpredictability.

    ERIC Educational Resources Information Center

    Gilliland, Martha W.; Tynan, Amelia

    1997-01-01

    Because the environment in which organizations operate is changing unpredictably, traditional leadership approaches work poorly. Effective leadership focuses on finding solutions for the future and enabling their implementation. At the University of Arizona's Center for Computing and Information Technology and Faculty Development Program, this…

  12. Episyenites within the Tauern Window metagranitoids: unpredictable?

    NASA Astrophysics Data System (ADS)

    Pennacchioni, Giorgio; Ceccato, Alberto; Fioretti, Anna Maria; Mazzoli, Claudio; Zorzi, Federico; Ferretti, Patrizia

    2015-04-01

    The core of the Tauern tectonic window (Eastern Alps) consists of dominant pre-Alpine granitoids (~295 Ma) that were metamorphosed and deformed during the Alpine orogenesis (at ~30 Ma). Ductile deformation at peak conditions (550-600 ° C and 0.5-0.7 GPa) was followed by cataclastic faulting (Pennacchioni and Mancktelow, 2007). Both deformation phases occurred in a fluid-rich environment with formation of veins filled with quartz- calcite-biotite-feldspar and quartz-chlorite-epidote-adularia-calcite, respectively. Faults are typically low displacement strike-slip structures (offset < 1m) organized in en-echelon arrays at different scales with a stepping geometry consistent with the sense of fault slip (e.g. left-stepping for dextral slip). Fault stepovers include pervasive fracturing dominated by a set of antithetic faults (Pennacchioni and Mancktelow, 2013). These faults were locally exploited by episyenitic alteration which represented the "last" event of fluid-rock interaction in the Tauern metagranitoids. Episyenites within metagranodiorites have a macroscopic porosity in the range between 25 and 35% volume (determined by microtomography), mostly derived from dissolution of multi-mm-sized quartz. Recent glacier-polished outcrops provide a unique opportunity to investigate the relationships between episyenites and overprinted faults. Detailed field mapping of a selected outcrop indicates that episyenites: (i) are spatially linked to precursor faults and statically overprinted all previous structures; (ii) occur discontinuously along faults; (iii) have a thickness (of as much as a few meters) that does not correlate with either the amount of fault slip or the density of the fracture network; (iv) developed independently of rock type (passing "undisturbed" lithologic boundaries with conspicuous variations of quartz grain size of the protolith lithology). Although the faults in the studied outcrop are extensively decorated by relatively large volumes of episyenite, occurrences of episyenite in the Tauern granitoids are generally rare. This study indicates that there is not a simple way to predict the location and the extent of episyenite alteration from the geometry and fracturing patterns of the network of precursor cataclastic faults. The dominant quartz dissolution during episyenitization was accompanied and/or followed by: (i) pervasive substitution of oligoclase and chlorite/biotite of the metagranodiorite by albite and clay-minerals, respectively, and (ii) limited precipitation of new adularia, anatase, calcite, hematite and zeolite within pores. Isotopic data from calcite filling the episyenite porosity suggest a meteoric source of the fluids (?18O (SMOW) ˜ -2 o). In contrast, fluids synkinematic with previous episodes of fluid-rock interaction during faulting and ductile shearing had a deeper origin (?18O (SMOW) ˜ 8-9 o). References Pennacchioni, G., Mancktelow, N.S., 2007. J. Struct. Geol. 29, 1757-1780. Pennacchioni, G., Mancktelow, N.S., 2013. Geol. Soc. Am. Bull. 125, 1468-1483.

  13. Epistatic interactions among metabolic genes depend upon environmental conditions.

    PubMed

    Jagdishchandra Joshi, Chintan; Prasad, Ashok

    2014-10-01

    When the effect of the state of one gene is dependent on the state of another gene in more than an additive or a neutral way, the phenomenon is termed epistasis. In particular, positive epistasis signifies that the impact of the double deletion is less severe than the neutral combination, while negative epistasis signifies that the double deletion is more severe. Epistatic interactions between genes affect the fitness landscape of an organism in its environment and are believed to be important for the evolution of sex and the evolution of recombination. Here we use large-scale computational metabolic models of microorganisms to study epistasis computationally using Flux Balance Analysis (FBA). We study what the effects of the environment are on epistatic interactions between metabolic genes in three different microorganisms: the model bacterium E. coli, the cyanobacteria Synechocystis PCC6803 and the model green algae, C. reinhardtii. Prior studies have shown that under standard laboratory conditions epistatic interactions between metabolic genes are dominated by positive epistasis. We show here that epistatic interactions depend strongly upon environmental conditions, i.e. the source of carbon, the carbon/oxygen ratio, and for photosynthetic organisms, the intensity of light. By a comparative analysis of flux distributions under different conditions, we show that whether epistatic interactions are positive or negative depends upon the topology of the carbon flow between the reactions affected by the pair of genes being considered. Thus complex metabolic networks can show epistasis even without explicit interactions between genes, and the direction and the scale of epistasis are dependent on network flows. Our results suggest that the path of evolutionary adaptation in fluctuating environments is likely to be very history dependent because of the strong effect of the environment on epistasis. PMID:25018101

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

    PubMed Central

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

    2015-01-01

    Diesel exhaust (DE) contains a variety of toxic air pollutants, including diesel particulate matter (DPM) and gaseous contaminants (e.g., carbon monoxide (CO)). DPM is dominated by fine (PM2.5) and ultrafine particles (UFP), and can be representatively determined by its thermal-optical refractory as elemental carbon (EC) or light-absorbing characteristics as black carbon (BC). The currently accepted reference method for sampling and analysis of occupational exposure to DPM is the National Institute for Occupational Safety and Health (NIOSH) Method 5040. However, this method cannot provide in-situ short-term measurements of DPM. Thus, real-time monitors are gaining attention to better examine DE exposures in occupational settings. However, real-time monitors are subject to changing environmental conditions. Field measurements have reported interferences in optical sensors and subsequent real-time readings, under conditions of high humidity and abrupt temperature changes. To begin dealing with these issues, we completed a controlled study to evaluate five real-time monitors: Airtec real-time DPM/EC Monitor, TSI SidePak Personal Aerosol Monitor AM510 (PM2.5), TSI Condensation Particle Counter 3007, microAeth AE51 BC Aethalometer, and Langan T15n CO Measurer. Tests were conducted under different temperatures (55, 70, and 80 °F), relative humidity (10, 40, and 80%), and DPM concentrations (50 and 200 µg/m3) in a controlled exposure facility. The 2-hour averaged EC measurements from the Airtec instrument showed relatively good agreement with NIOSH Method 5040 (R2=0.84; slope=1.17±0.06; N=27) and reported ~17% higher EC concentrations than the NIOSH reference method. Temperature, relative humidity, and DPM levels did not significantly affect relative differences in 2-hour averaged EC concentrations obtained by the Airtec instrument versus the NIOSH method (p<0.05). Multiple linear regression analyses, based on 1-min averaged data, suggested combined effects of up to 5% from relative humidity and temperature on real-time measurements. The overall deviations of these real-time monitors from the NIOSH method results were ≤20%. However, simultaneous monitoring of temperature and relative humidity is recommended in field investigations to understand and correct for environmental impacts on real-time monitoring data. PMID:25894766

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

    PubMed Central

    Haande, Sigrid; Molversmyr, Åge

    2015-01-01

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

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

    PubMed

    Pottosin, Igor; Shabala, Sergey

    2016-03-01

    Chloroplasts are central to solar light harvesting and photosynthesis. Optimal chloroplast functioning is vitally dependent on a very intensive traffic of metabolites and ions between the cytosol and stroma, and should be attuned for adverse environmental conditions. This is achieved by an orchestrated regulation of a variety of transport systems located at chloroplast membranes such as porines, solute channels, ion-specific cation and anion channels, and various primary and secondary active transport systems. In this review we describe the molecular nature and functional properties of the inner and outer envelope and thylakoid membrane channels and transporters. We then discuss how their orchestrated regulation affects thylakoid structure, electron transport and excitation energy transfer, proton-motive force partition, ion homeostasis, stromal pH regulation, and volume regulation. We link the activity of key cation and anion transport systems with stress-specific signaling processes in chloroplasts, and discuss how these signals interact with the signals generated in other organelles to optimize the cell performance, with a special emphasis on Ca(2+) and reactive oxygen species signaling. PMID:26597501

  17. Environmental Conditions in a Chamber with Dry Ice.

    PubMed

    Artwohl, James E.; Kovacs, Mark; Bennett, B. Taylor

    1999-01-01

    Dry ice is used in research laboratories as a source of CO2 for euthanasia of rodents. The present study was performed to evaluate environmental conditions created in a standard (9-liter) bell jar. By using a portable gas analyzer and measuring at 7.5 cm above the platform, we evaluated the chamber filling rate at room temperature with a known quantity of dry ice, maintenance of 70% CO2, and concentration of CO2 maintained when the top of the chamber was removed and replaced. Ambient temperature in the chamber and temperature of the platform were also measured. Results indicated that 500 g dry ice was required to maintain the filling rate and CO2 concentration at levels recommended by the American Veterinary Medical Association Panel on Euthanasia; that after removal of an animal, the lid should be replaced for 1 min before placing another animal in the chamber; and that although ambient temperature in the chamber never fell below 178C during an 80-min period, the platform temperature decreased to 08C. If a chamber must be used as described above for more than 1 h, consideration should be given to alternating between two chambers and allowing a chamber to warm to room temperature before reuse. PMID:12086455

  18. Age at menarche: the influence of environmental conditions

    NASA Astrophysics Data System (ADS)

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

    1988-03-01

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

  19. Impact of environmental conditions on the survival of cryptosporidium and giardia on environmental surfaces.

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  1. Seed germination ecology of the summer annual Cyperus squarrosus in an unpredictable mudflat habitat

    NASA Astrophysics Data System (ADS)

    Baskin, Carol C.; Baskin, Jerry M.; Chester, Edward W.

    2004-07-01

    The purpose of our study was to better understand seed germination ecology of the summer annual sedge Cyperus squarrosus, which grows in various habitats, including mudflats and shallow soil over limestone bedrock (rock outcrops), where timing of the period favorable for germination and completion of the life cycle is unpredictable. Over a 28.5-month period, temperature and light:dark requirements for germination were determined at monthly intervals for seeds collected from mudflats and buried under flooded and under nonflooded conditions at natural temperature regimes. Data on dormancy and germination were compared to those published for seeds collected from plants growing on rock outcrops. Under both flooded and nonflooded conditions, seeds from mudflats exhibited an annual conditional dormancy/nondormancy cycle, similar to those from rock outcrops buried under nonflooded conditions. Seeds from mudflats germinated to higher percentages at mid-summer temperatures (35/20 °C) in mid-summer than those from rock outcrops. On the other hand, seeds from rock outcrops germinated to higher percentages at March temperatures (15/6 °C) in March than those from mudflats. Thus, seeds could germinate on mudflats any time from April through September if dewatering occurred, and they could germinate on rock outcrops any time from March through June and in September if soil moisture was nonlimiting; in both habitats light would be required for germination. Since seeds on mudflats may be flooded for several consecutive years, mudflats are more unpredictable than rock outcrops. Ability of seeds from mudflats to germinate to high percentages in light at 35/20 °C throughout the summer and those from rock outcrops not to do so may be related to the greater unpredictability of the mudflat. Each year for 11 years, seeds germinated in mudflat soil samples kept in a nonheated greenhouse, reaching a total of 22526 ± 1401 (mean ± S.E.) seeds m -2; thus, the species has the potential to form a large long-lived persistent soil seed bank.

  2. The role of an alpha animal in changing environmental conditions.

    PubMed

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

    2014-06-22

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

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

    PubMed

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

    2015-01-01

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

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

    SciTech Connect

    Jantzen, C.M.

    1988-01-01

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

  6. EVALUATION OF GEOMEMBRANE SEAMS EXPOSED TO SELECTED ENVIRONMENTAL CONDITIONS

    EPA Science Inventory

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

  7. Clocking in the face of unpredictability beyond quantum uncertainty

    NASA Astrophysics Data System (ADS)

    Madjid, F. Hadi; Myers, John M.

    2015-05-01

    In earlier papers we showed unpredictability beyond quantum uncertainty in atomic clocks, ensuing from a proven gap between given evidence and explanations of that evidence. Here we reconceive a clock, not as an isolated entity, but as enmeshed in a self-adjusting communications network adapted to one or another particular investigation, in contact with an unpredictable environment. From the practical uses of clocks, we abstract a clock enlivened with the computational capacity of a Turing machine, modified to transmit and to receive numerical communications. Such "live clocks" phase the steps of their computations to mesh with the arrival of transmitted numbers. We lift this phasing, known in digital communications, to a principle of logical synchronization, distinct from the synchronization defined by Einstein in special relativity. Logical synchronization elevates digital communication to a topic in physics, including applications to biology. One explores how feedback loops in clocking affect numerical signaling among entities functioning in the face of unpredictable influences, making the influences themselves into subjects of investigation. The formulation of communications networks in terms of live clocks extends information theory by expressing the need to actively maintain communications channels, and potentially, to create or drop them. We show how networks of live clocks are presupposed by the concept of coordinates in a spacetime. A network serves as an organizing principle, even when the concept of the rigid body that anchors a special-relativistic coordinate system is inapplicable, as is the case, for example, in a generic curved spacetime.

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

    EPA Science Inventory

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

  9. Behavioral and neurochemical effects of dietary methyl donor deficiency combined with unpredictable chronic mild stress in rats.

    PubMed

    Javelot, H; Messaoudi, M; Jacquelin, C; Bisson, J F; Rozan, P; Nejdi, A; Lazarus, C; Cassel, J C; Strazielle, C; Lalonde, R

    2014-03-15

    Methyl donor deficiencies and chronic stress cause depression independently, but their interaction has never been thoroughly evaluated. In our study, methyl donor deficient diet and chronic stress condition consisted respectively of a B2, B9, B12, and choline-free diet and a chronic mild stress procedure. Rats were randomly assigned to six groups with three "diet" conditions (free-feeding, pair-fed and methyl donor deficient diet) and two "stress" conditions (no-stress and stress) and were evaluated in the open-field, the elevated plus-maze and the forced swimming test. After the behavioral evaluation, corticosterone and homocysteine plasma levels were measured and dopamine, DOPAC, serotonin, 5HIAA concentrations were evaluated in several brain areas. Rats given a methyl donor deficient diet for 11 weeks causing elevated plasma homocysteine levels were compared to pair-fed and free-feeding rats with or without unpredictable chronic mild stress. Regardless of stress environmental conditions, the methyl donor deficient diet decreased plasma corticosterone levels and caused disinhibition in the elevated plus-maze condition relative to both control groups. However, stress potentiated the effects of the deficient regimen on rearing in the open-field and climbing in the forced swim test. The dietary changes involved in behavior and plasma corticosterone could be caused by homocysteine-induced decreases in dopamine and 5-hydroxytryptamine metabolites in selective brain regions and it can be noted that regardless of stress-conditions, methyl donor deficient diet decreases DOPAC/dopamine and 5HIAA/serotonin ratios in striatum and hypothalamus and selectively 5HIAA/serotonin ratio in the sensorimotor cortex. Our experimental data is particularly relevant in the context of neuropsychiatric disorders frequently associated with folate deficiency and hyperhomocysteinemia. PMID:24333542

  10. INTEGRATED ASSESSMENTS OF THE ENVIRONMENTAL CONDITION OF THE CHESAPEAKE BAY

    EPA Science Inventory

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

  11. Environmental conditions that influence toxin biosynthesis in cyanobacteria.

    PubMed

    Neilan, Brett A; Pearson, Leanne A; Muenchhoff, Julia; Moffitt, Michelle C; Dittmann, Elke

    2013-05-01

    Over the past 15 years, the genetic basis for production of many cyanobacterial bioactive compounds has been described. This knowledge has enabled investigations into the environmental factors that regulate the production of these toxins at the molecular level. Such molecular or systems level studies are also likely to reveal the physiological role of the toxin and contribute to effective water resource management. This review focuses on the environmental regulation of some of the most relevant cyanotoxins, namely the microcystins, nodularin, cylindrospermopsin, saxitoxins, anatoxins and jamaicamides. PMID:22429476

  12. Perceiving environmental properties from motion information: Minimal conditions

    NASA Technical Reports Server (NTRS)

    Proffitt, Dennis R.; Kaiser, Mary K.

    1989-01-01

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

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

    PubMed Central

    Madden, Louise C.; Simmons, Peter A.

    2013-01-01

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

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

    PubMed Central

    Fobil, Julius; May, Juergen; Kraemer, Alexander

    2010-01-01

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

  15. EFFECTS OF ENVIRONMENTAL CONDITIONS ON ISOPRENE EMISSION FROM LIVE OAK

    EPA Science Inventory

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

  16. Energy systems and their technical, economic and environmental boundary conditions

    NASA Astrophysics Data System (ADS)

    Routti, Jorma

    Energy systems consisting of energy supply, transportation conversion and consumption form a cornerstone of industrial societies. Their evolution is dictated by technical, economic and environmental possibilities and constraints, as well as by political and societal aspects. Fossil fuels still cover 80 percent of world energy supplies. Future energy systems are based in both nuclear energy and renewable solar based supplies. Shorter term questions in Finland concentrate on the options of building additional and replacing old electricity whose market share has increased rapidly. Increasing energy efficiencies provide partial solutions, but also new capacity of the order of 1 to 2 GWe based on nuclear, coal, natural gas and/or domestic fuels is needed. Recent studies of thse equations are discussed.

  17. Controllability modulates the neural response to predictable but not unpredictable threat in humans.

    PubMed

    Wood, Kimberly H; Wheelock, Muriah D; Shumen, Joshua R; Bowen, Kenton H; Ver Hoef, Lawrence W; Knight, David C

    2015-10-01

    Stress resilience is mediated, in part, by our ability to predict and control threats within our environment. Therefore, determining the neural mechanisms that regulate the emotional response to predictable and controllable threats may provide important new insight into the processes that mediate resilience to emotional dysfunction and guide the future development of interventions for anxiety disorders. To better understand the effect of predictability and controllability on threat-related brain activity in humans, two groups of healthy volunteers participated in a yoked Pavlovian fear conditioning study during functional magnetic resonance imaging (fMRI). Threat predictability was manipulated by presenting an aversive unconditioned stimulus (UCS) that was either preceded by a conditioned stimulus (i.e., predictable) or by presenting the UCS alone (i.e., unpredictable). Similar to animal model research that has employed yoked fear conditioning procedures, one group (controllable condition; CC), but not the other group (uncontrollable condition; UC) was able to terminate the UCS. The fMRI signal response within the dorsolateral prefrontal cortex (PFC), dorsomedial PFC, ventromedial PFC, and posterior cingulate was diminished during predictable compared to unpredictable threat (i.e., UCS). In addition, threat-related activity within the ventromedial PFC and bilateral hippocampus was diminished only to threats that were both predictable and controllable. These findings provide insight into how threat predictability and controllability affects the activity of brain regions (i.e., ventromedial PFC and hippocampus) involved in emotion regulation, and may have important implications for better understanding neural processes that mediate emotional resilience to stress. PMID:26149610

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

    PubMed

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

    2015-04-01

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

  19. Environmental, health and economic conditions perceived by 50 rural communities in Bangladesh.

    PubMed

    Ohtsuka, Ryutaro; Inaoka, Tsukasa; Moji, Kazuhiko; Karim, Enamul; Yoshinaga, Mari

    2002-12-01

    For randomly selected 50 villages in Bangladesh, an interview survey with a structured questionnaire was conducted to reveal their perception on the environmental, health and economic conditions at present and for the past 10-year change. The eight following items were analyzed in this paper: air pollution and water pollution, which represent environmental conditions with close relation to health conditions, soil degradation and deforestation, which represent environmental conditions with close relation to economic conditions, epidemic diseases and malnutrition, which represent health conditions, and poverty and jobless, which represent economic conditions. Among the 50 villages, deforestation was most frequently perceived serious at present and worsened in the past 10 years. Of the remaining seven items, those related to economic conditions were more seriously perceived than those related to health and environmental conditions. As revealed by the cluster analysis for the inter-item relations, epidemic diseases, which formed the same cluster with the environmental items, were recognized less serious whereas malnutrition, which formed the same cluster with the economic items, was recognized more serious. These findings are useful not only for rural development programs but also for mitigation programs toward health and environmental hazards in Bangladesh. PMID:12908331

  20. Chaotic Stochasticity: A Ubiquitous Source of Unpredictability in Epidemics

    NASA Astrophysics Data System (ADS)

    Rand, D. A.; Wilson, H. B.

    1991-11-01

    We address the question of whether or not childhood epidemics such as measles and chickenpox are chaotic, and argue that the best explanation of the observed unpredictability is that it is a manifestation of what we call chaotic stochasticity. Such chaos is driven and made permanent by the fluctuations from the mean field encountered in epidemics, or by extrinsic stochastic noise, and is dependent upon the existence of chaotic repellors in the mean field dynamics. Its existence is also a consequence of the near extinctions in the epidemic. For such systems, chaotic stochasticity is likely to be far more ubiquitous than the presence of deterministic chaotic attractors. It is likely to be a common phenomenon in biological dynamics.

  1. Overview of environmental and hydrogeologic conditions at Barrow, Alaska

    USGS Publications Warehouse

    McCarthy, K.A.

    1994-01-01

    To assist the Federal Aviation Administration (FAA) in evaluating the potential effects of environmental contamination at their facility in Barrow, Alaska, a general assessment was made of the hydrologic system is the vicinity of the installation. The City of Barrow is located approximately 16 kilometers southwest of Point Barrow, the northernmost point in Alaska, and therefore lies within the region of continuous permafrost. Migration of surface or shallow- subsurface chemical releases in this environ- ment would be largely restricted by near-surface permafrost to surface water and the upper, suprapermafrost zone of the subsurface. In the arctic climate and tundra terrain of the Barrow area, this shallow environment has a limited capacity to attenuate the effects of either physical disturbances or chemical contamination and is therefore highly susceptible to degradation. Esatkuat Lagoon, the present drink- ing water supply for the City of Barrow, is located approximately 2 kilometers from the FAA facility. This lagoon is the only practical source of drinking water available to the City of Barrow because alternative sources of water in the area are (1) frozen throughout most of the year, (2) insufficient in volume, (3) of poor quality, or (4) too costly to develop and distribute.

  2. Multivariable environmental conditions promote photosynthetic adaptation potential in Arabidopsis thaliana.

    PubMed

    Wituszy?ska, Weronika; Ga??zka, Kamila; Rusaczonek, Anna; Vanderauwera, Sandy; Van Breusegem, Frank; Karpi?ski, Stanis?aw

    2013-04-15

    Most of our knowledge on the regulation of photosynthesis originates from studies performed in highly controlled laboratory conditions. However, in their natural habitats plants are simultaneously subjected to a broad range of abiotic and biotic stimuli which influence photosynthetic efficiency; hence there is an emerging need to examine the process of photosynthesis under multivariable field conditions in order to elucidate the mechanisms that underlie its regulation. Such knowledge has potential for providing novel targets that would improve both crop yield and performance. In the present study we compared laboratory- and field-grown Arabidopsis thaliana plants in terms of photosynthetic efficiency in modulated light intensities and CO2 concentrations. We show here that the field-acclimated plants display highly efficient photosynthesis and are more tolerant to variable light intensities and CO2 concentrations than their laboratory-grown counterparts. We also demonstrate that some structural rearrangements of LHCII and PSII, together with altered pigments composition and stomatal density, are responsible for the differences in assimilation and photochemistry. Furthermore, we employ a transcript profiling approach to explain the genetic mechanisms underlying these adaptations and suggest that they are mainly induced by the high and fluctuating light intensities which occur in the natural environment. PMID:23287000

  3. 76 FR 22161 - Fifty Seventh Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ... Conditions and Test Procedures for Airborne Equipment AGENCY: Federal Aviation Administration (FAA... Conditions and Test Procedures for Airborne Equipment. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 135: Environmental Conditions and Test Procedures...

  4. Rift Valley Fever Outbreaks in Mauritania and Related Environmental Conditions

    PubMed Central

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

    2014-01-01

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

  5. Corrosion behavior of carbon steels under tuff repository environmental conditions

    SciTech Connect

    McCright, R.D.; Weiss, H.

    1984-10-01

    Carbon steels may be used for borehole liners in a potential high-level nuclear waste repository in tuff in Nevada. Borehole liners are needed to facilitate emplacement of the waste packages and to facilitate retrieval of the packages, if required. Corrosion rates of low carbon structural steels AISI 1020 and ASTM A-36 were determined in J-13 well water and in saturated steam at 100{sup 0}C. Tests were conducted in air-sparged J-13 water to attain more oxidizing conditions representative of irradiated aqueous environments. A limited number of irradiation corrosion and stress corrosion tests were performed. Chromium-molybdenum alloy steels and cast irons were also tested. These materials showed lower general corrosion but were susceptible to stress corrosion cracking when welded. 4 references, 4 tables.

  6. Relationships among fisheries exploitation, environmental conditions, and ecological indicators across a series of marine ecosystems

    NASA Astrophysics Data System (ADS)

    Fu, Caihong; Large, Scott; Knight, Ben; Richardson, Anthony J.; Bundy, Alida; Reygondeau, Gabriel; Boldt, Jennifer; van der Meeren, Gro I.; Torres, Maria A.; Sobrino, Ignacio; Auber, Arnaud; Travers-Trolet, Morgane; Piroddi, Chiara; Diallo, Ibrahima; Jouffre, Didier; Mendes, Hugo; Borges, Maria Fatima; Lynam, Christopher P.; Coll, Marta; Shannon, Lynne J.; Shin, Yunne-Jai

    2015-08-01

    Understanding how external pressures impact ecosystem structure and functioning is essential for ecosystem-based approaches to fisheries management. We quantified the relative effects of fisheries exploitation and environmental conditions on ecological indicators derived from two different data sources, fisheries catch data (catch-based) and fisheries independent survey data (survey-based) for 12 marine ecosystems using a partial least squares path modeling approach (PLS-PM). We linked these ecological indicators to the total biomass of the ecosystem. Although the effects of exploitation and environmental conditions differed across the ecosystems, some general results can be drawn from the comparative approach. Interestingly, the PLS-PM analyses showed that survey-based indicators were less tightly associated with each other than the catch-based ones. The analyses also showed that the effects of environmental conditions on the ecological indicators were predominantly significant, and tended to be negative, suggesting that in the recent period, indicators accounted for changes in environmental conditions and the changes were more likely to be adverse. Total biomass was associated with fisheries exploitation and environmental conditions; however its association with the ecological indicators was weak across the ecosystems. Knowledge of the relative influence of exploitation and environmental pressures on the dynamics within exploited ecosystems will help us to move towards ecosystem-based approaches to fisheries management. PLS-PM proved to be a useful approach to quantify the relative effects of fisheries exploitation and environmental conditions and suggest it could be used more widely in fisheries oceanography.

  7. EVALUATION OF WASTE PACKAGE EXTERNAL ENVIRONMENTAL CONDITION STUDY

    SciTech Connect

    E. N. Lindner and E. F. Dembowski

    1998-07-23

    The U. S. Department of Energy (DOE) is studying Yucca Mountain as the possible site for a permanent underground repository for disposal of spent nuclear fuel (SNF) and other high-level waste (HLW). The emplacement of high-level radioactive waste in Yucca Mountain will release a large amount of heat into the rock above and below the repository. Due to this heat, the rock temperature will rise, and then decrease when the production of decay heat falls below the rate at which heat escapes from the hot zone. In addition to raising the rock temperature, the heat will vaporize water, which will condense in cooler regions. The condensate water may drain back toward the emplacement drifts or it may ''shed'' through the pillars between emplacement drifts. Other effects, such as coupled chemical and mechanical processes, may influence the movement of water above, within, and below the emplacement drifts. This study examined near field environmental parameters that could have an effect on the waste package, including temperature, humidity, seepage rate, pH of seepage, chemistry (dissolved salts/minerals) of seepage, composition of drift atmosphere, colloids, and biota. This report is a Type I analysis performed in support of the development of System Description Documents (SDDs). A Type I analysis is a quantitative or qualitative analysis that may fulfill any of a variety of purposes associated with the Monitored Geologic Repository (MGR), other than providing direct analytical support for design output documents. A Type I analysis may establish design input, as defined in the ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998). This study establishes a technical basis for emplacement drift (i.e. at the waste package surface) environment criteria to be considered in the development of the waste package design. The information will support development of several SDDs and resolve emplacement drift external environment questions in the criteria of those documents. This study supports the following System Description Documents (SDDs): Uncanistered SNF Disposal Container, Canistered SNF Disposal Container, DHLW Disposal Container, DOE Waste Forms Disposal Container, Non-Fuel Components Disposal Container, Naval SNF Disposal Container and Ex-Container Systems development. Minimum and maximum bounding values for the parameters described in the scope of this study are established to support environment criteria development for those systems.

  8. Sustainable Environmental Education: Conditions and Characteristics Needed for a Successfully Integrated Program in Public Elementary Schools

    NASA Astrophysics Data System (ADS)

    Rieckenberg, Cara Rae

    This case study investigated what conditions and characteristics contributed to a successful environmental education program within elementary schools of a school district where environmental education was the mandate. While research does exist on practical application of environmental education within schools, little if any literature has been written or research conducted on schools actually implementing environmental education to study what contributes to the successful implementation of the program. To study this issue, 24 participants from a Midwestern school district were interviewed, six of whom were principals of each of the six elementary schools included in the study. All participants were identified as champions of environmental education integration within their buildings due to leadership positions held focused on environmental education. Analysis of the data collected via interviews revealed findings that hindered the implementation of environmental education, findings that facilitated the implementation of environmental education, and findings that indicated an environmental education-focused culture existed within the schools. Conditions and characteristics found to contribute to the success of these school's environmental education programs include: professional development opportunities, administrative support, peer leadership opportunities and guidance, passion with the content and for the environment, comfort and confidence with the content, ease of activities and events that contribute to the culture and student success. Keywords: environmental education, integration, leadership, teachers as leaders.

  9. Environmental and behavioral conditions of bathing among elderly Japanese.

    PubMed

    Takasaki, Yuji; Ohnaka, Tadakatsu; Tochihara, Yutaka; Nagai, Yumiko; Ito, Hiromitsu; Yoshitake, Shiro

    2007-03-01

    This study investigated the bathing conditions of elderly Japanese, and sought to find factors relating to regional differences in death rates from bathtub accidents. A questionnaire survey was carried out in 11 areas of Japan. Questionnaires including questions regarding the length of time since houses had been built, types of facilities, and subjects' indoor thermal sensations and behavior while bathing were distributed to detached houses in each area twice, once in summer and once in winter. Completed questionnaires were collected from approximately 160 elderly people over 65 years old. Information regarding thermal sensations of rooms in winter revealed that a prefabricated bath and insulating window glass eased the cold in the bathroom. Unexpectedly, more subjects in the southern region than in the northern region reported being cold or a little cold while bathing in winter. In the present study, thermal sensations and behaviors while bathing seemed to be more affected by facilities and the location of houses than by the sex and age of the subjects. PMID:17435371

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

    EPA Science Inventory

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

  11. Multifunctional integrated optical circuit for the fiber gyro under environmental conditions

    NASA Astrophysics Data System (ADS)

    Regener, Rolf A.

    1989-02-01

    Pigtailed Ti:LiNbO3 multifunctional integrated optical circuits for use in fiber gyros have been developed and tested under environmental conditions. Emphasis has been placed on reliability of the fiber-to-waveguide attachment.

  12. Damage detection under varying environmental and operational conditions using Wavelet Transform Modulus Maxima decay lines similarity

    NASA Astrophysics Data System (ADS)

    Tjirkallis, A.; Kyprianou, A.

    2016-01-01

    Over the last three decades, there have been increasing demands to develop and deploy Structural Health Monitoring (SHM) systems for engineering structures in service. Since these structures are subjected to varying environmental and operational conditions, reliable SHM methodologies must be capable of not misattributing to damage changes due to environmental conditions. This paper presents a novel damage detection methodology based on the similarity between maxima decay lines of the continuous wavelet transform scalogram of the structural responses obtained under different operational and environmental conditions. The normalized cross correlation (NCC) is used as a measure of this similarity. In addition, the pointwise summation of similar Wavelet Transform Modulus Maxima (WTMM) decay lines is used to identify changes due to the presence of damage from different force realizations and/or varying environmental conditions. The effectiveness of the proposed methodology is demonstrated using a simulated 3DOF system and an experimental cantilever beam.

  13. 33 CFR 148.710 - What environmental conditions must be satisfied?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... serves the national interest. (c) In accordance with 40 CFR 1502.9, the Commandant (CG-5) will prepare a... HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: GENERAL Environmental Review Criteria for Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license...

  14. 33 CFR 148.710 - What environmental conditions must be satisfied?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... deepwater port for oil clearly best serves the national interest. (c) In accordance with 40 CFR 1502.9, the... HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: GENERAL Environmental Review Criteria for Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license...

  15. 33 CFR 148.710 - What environmental conditions must be satisfied?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... serves the national interest. (c) In accordance with 40 CFR 1502.9, the Commandant (CG-5) will prepare a... HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: GENERAL Environmental Review Criteria for Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license...

  16. 33 CFR 148.710 - What environmental conditions must be satisfied?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... deepwater port for oil clearly best serves the national interest. (c) In accordance with 40 CFR 1502.9, the... HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: GENERAL Environmental Review Criteria for Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license...

  17. 33 CFR 148.710 - What environmental conditions must be satisfied?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... serves the national interest. (c) In accordance with 40 CFR 1502.9, the Commandant (CG-5) will prepare a... HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: GENERAL Environmental Review Criteria for Deepwater Ports § 148.710 What environmental conditions must be satisfied? (a) MARAD may issue a license...

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

    ERIC Educational Resources Information Center

    Hill, Grant; Hulbert, George

    2007-01-01

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

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

    EPA Science Inventory

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

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

    ERIC Educational Resources Information Center

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

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

  1. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Air conditioning environmental test facility ambient requirements. 86.161-00 Section 86.161-00 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations...

  2. 40 CFR 86.1312-2007 - Filter stabilization and microbalance workstation environmental conditions, microbalance...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 20 2012-07-01 2012-07-01 false Filter stabilization and microbalance workstation environmental conditions, microbalance specifications, and particulate matter filter handling and weighing procedures. 86.1312-2007 Section 86.1312-2007 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

  3. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Air conditioning environmental test facility ambient requirements. 86.161-00 Section 86.161-00 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations...

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

    EPA Science Inventory

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

  5. 75 FR 9016 - Fifty-Fifth Meeting, RTCA Special Committee 135: Environmental Conditions and Test Procedures for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-26

    ... and Test Procedures for Airborne Equipment AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 135: Environmental Conditions and Test Procedures for Airborne Equipment... Committee 135: Environmental Conditions and Test Procedures for Airborne Equipment. DATES: The meeting...

  6. Disease in a more variable and unpredictable climate

    NASA Astrophysics Data System (ADS)

    McMahon, T. A.; Raffel, T.; Rohr, J. R.; Halstead, N.; Venesky, M.; Romansic, J.

    2014-12-01

    Global climate change is shifting the dynamics of infectious diseases of humans and wildlife with potential adverse consequences for disease control. Despite this, the role of global climate change in the decline of biodiversity and the emergence of infectious diseases remains controversial. Climate change is expected to increase climate variability in addition to increasing mean temperatures, making climate less predictable. However, few empirical or theoretical studies have considered the effects of climate variability or predictability on disease, despite it being likely that hosts and parasites will have differential responses to climatic shifts. Here we present a theoretical framework for how temperature variation and its predictability influence disease risk by affecting host and parasite acclimation responses. Laboratory experiments and field data on disease-associated frog declines in Latin America support this framework and provide evidence that unpredictable temperature fluctuations, on both monthly and diurnal timescales, decrease frog resistance to the pathogenic chytrid fungus Batrachochytrium dendrobatidis (Bd). Furthermore, the pattern of temperature-dependent growth of the fungus on frogs was inconsistent with the pattern of Bd growth in culture, emphasizing the importance of accounting for the host-parasite interaction when predicting climate-dependent disease dynamics. Consistent with our laboratory experiments, increased regional temperature variability associated with global El Niño climatic events was the best predictor of widespread amphibian losses in the genus Atelopus. Thus, incorporating the effects of small-scale temporal variability in climate can greatly improve our ability to predict the effects of climate change on disease.

  7. Neurochemical and Behavioral Effects of Chronic Unpredictable Stress

    PubMed Central

    Matuszewich, Leslie; McFadden, Lisa M.; Friedman, Ross D.; Frye, Cheryl A.

    2014-01-01

    Chronic stress can influence behaviors associated with medial prefrontal cortex (mPFC) function, such as cognition and emotion regulation. Dopamine in the mPFC is responsive to stress and modulates its behavioral effects. The current study tested whether exposure to 10 days of chronic unpredictable stress (CUS) altered the effects of acute elevation stress on dopamine release in the mPFC and on spatial recognition memory. Male rats previously exposed to CUS or non-stressed controls were tested behaviorally, and underwent microdialysis to assess mPFC dopamine or had blood sampled for corticosterone analysis. Dopamine in the mPFC significantly increased in both groups during acute elevation stress compared to baseline levels but was attenuated in CUS rats compared to controls. Control rats exposed to elevation stress immediately prior to the T-maze showed impaired performance, whereas CUS rats did not. No group differences were observed in general motor activity or plasma corticosterone following elevation stress. The present results indicate that prior exposure to this particular CUS procedure reduced dopamine release in the mPFC during acute elevation stress and prevented the impairment of performance on a spatial recognition test following an acute stressor. These findings may contribute to an understanding the complex behavioral consequences of stress. PMID:25003946

  8. Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence

    PubMed Central

    Chaby, Lauren E.; Cavigelli, Sonia A.; White, Amanda; Wang, Kayllie; Braithwaite, Victoria A.

    2013-01-01

    Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid “stress” hormone response matures and specific regions in the brain undergo considerable change. Aversive experiences during this time might, therefore, be expected to generate long-term consequences for the adult phenotype. Here we investigated the long-term effects of exposure to chronic unpredictable stress during adolescence on adult decision-making, coping response, cognitive bias, and exploratory behavior in rats. Rats exposed to chronic unpredictable stress (e.g., isolation, crowding, cage tilt) were compared to control animals that were maintained in standard, predictable conditions throughout development. Unpredictable stress during adolescence resulted in a suite of long-term behavioral and cognitive changes including a negative cognitive bias [F(1, 12) = 5.000, P < 0.05], altered coping response [T(1, 14) = 2.216, P = 0.04], and accelerated decision-making [T(1, 14) = 3.245, P = 0.01]. Exposure to chronic stress during adolescence also caused a short-term increase in boldness behaviors; in a novel object test 15 days after the last stressor, animals exposed to chronic unpredictable stress had decreased latencies to leave a familiar shelter and approach a novel object [T(1, 14) = 2.240, P = 0.04; T(1, 14) = 2.419, P = 0.03, respectively]. The results showed that stress during adolescence has long-term impacts on behavior and cognition that affect the interpretation of ambiguous stimuli, behavioral response to adverse events, and how animals make decisions. PMID:23847501

  9. Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence.

    PubMed

    Chaby, Lauren E; Cavigelli, Sonia A; White, Amanda; Wang, Kayllie; Braithwaite, Victoria A

    2013-01-01

    Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid "stress" hormone response matures and specific regions in the brain undergo considerable change. Aversive experiences during this time might, therefore, be expected to generate long-term consequences for the adult phenotype. Here we investigated the long-term effects of exposure to chronic unpredictable stress during adolescence on adult decision-making, coping response, cognitive bias, and exploratory behavior in rats. Rats exposed to chronic unpredictable stress (e.g., isolation, crowding, cage tilt) were compared to control animals that were maintained in standard, predictable conditions throughout development. Unpredictable stress during adolescence resulted in a suite of long-term behavioral and cognitive changes including a negative cognitive bias [F (1, 12) = 5.000, P < 0.05], altered coping response [T (1, 14) = 2.216, P = 0.04], and accelerated decision-making [T (1, 14) = 3.245, P = 0.01]. Exposure to chronic stress during adolescence also caused a short-term increase in boldness behaviors; in a novel object test 15 days after the last stressor, animals exposed to chronic unpredictable stress had decreased latencies to leave a familiar shelter and approach a novel object [T (1, 14) = 2.240, P = 0.04; T (1, 14) = 2.419, P = 0.03, respectively]. The results showed that stress during adolescence has long-term impacts on behavior and cognition that affect the interpretation of ambiguous stimuli, behavioral response to adverse events, and how animals make decisions. PMID:23847501

  10. 77 FR 15449 - 59th Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ... and Test Procedures for Airborne Equipment AGENCY: Federal Aviation Administration (FAA), U.S... Conditions and Test Procedures for Airborne Equipment. SUMMARY: The FAA is issuing this notice to advise the public of the fifty-ninth meeting of RTCA Special Committee 135, Environmental Conditions and...

  11. 78 FR 7850 - Sixty First Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-04

    ... and Test Procedures for Airborne Equipment AGENCY: Federal Aviation Administration (FAA), U.S... Conditions and Test Procedures for Airborne Equipment. SUMMARY: The FAA is issuing this notice to advise the public of the Sixty-First meeting of the RTCA Special Committee 135, Environmental Conditions and...

  12. 78 FR 43963 - Sixty-Second Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-22

    ... and Test Procedures for Airborne Equipment AGENCY: Federal Aviation Administration (FAA), U.S... Conditions and Test Procedures for Airborne Equipment. SUMMARY: The FAA is issuing this notice to advise the public of the Sixty-Second meeting of the RTCA Special Committee 135, Environmental Conditions and...

  13. 77 FR 56253 - 60th Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-12

    ... Test Procedures for Airborne Equipment AGENCY: Federal Aviation Administration (FAA), U.S. Department... Conditions and Test Procedures for Airborne Equipment SUMMARY: The FAA is issuing this notice to advise the public of the sixtieth meeting of the RTCA Special Committee 135, Environmental Conditions and...

  14. Coping with Unpredictability: Dopaminergic and Neurotrophic Responses to Omission of Expected Reward in Atlantic Salmon (Salmo salar L.)

    PubMed Central

    Vindas, Marco A.; Sørensen, Christina; Johansen, Ida B.; Folkedal, Ole; Höglund, Erik; Khan, Uniza W.; Stien, Lars H.; Kristiansen, Tore S.; Braastad, Bjarne O.; Øverli, Øyvind

    2014-01-01

    Comparative studies are imperative for understanding the evolution of adaptive neurobiological processes such as neural plasticity, cognition, and emotion. Previously we have reported that prolonged omission of expected rewards (OER, or ‘frustrative nonreward’) causes increased aggression in Atlantic salmon (Salmo salar). Here we report changes in brain monoaminergic activity and relative abundance of brain derived neurotrophic factor (BDNF) and dopamine receptor mRNA transcripts in the same paradigm. Groups of fish were initially conditioned to associate a flashing light with feeding. Subsequently, the expected food reward was delayed for 30 minutes during two out of three meals per day in the OER treatment, while the previously established routine was maintained in control groups. After 8 days there was no effect of OER on baseline brain stem serotonin (5-HT) or dopamine (DA) activity. Subsequent exposure to acute confinement stress led to increased plasma cortisol and elevated turnover of brain stem DA and 5-HT in all animals. The DA response was potentiated and DA receptor 1 (D1) mRNA abundance was reduced in the OER-exposed fish, indicating a sensitization of the DA system. In addition OER suppressed abundance of BDNF in the telencephalon of non-stressed fish. Regardless of OER treatment, a strong positive correlation between BDNF and D1 mRNA abundance was seen in non-stressed fish. This correlation was disrupted by acute stress, and replaced by a negative correlation between BDNF abundance and plasma cortisol concentration. These observations indicate a conserved link between DA, neurotrophin regulation, and corticosteroid-signaling pathways. The results also emphasize how fish models can be important tools in the study of neural plasticity and responsiveness to environmental unpredictability. PMID:24465595

  15. Coping with unpredictability: dopaminergic and neurotrophic responses to omission of expected reward in Atlantic salmon (Salmo salar L.).

    PubMed

    Vindas, Marco A; Sørensen, Christina; Johansen, Ida B; Folkedal, Ole; Höglund, Erik; Khan, Uniza W; Stien, Lars H; Kristiansen, Tore S; Braastad, Bjarne O; Øverli, Øyvind

    2014-01-01

    Comparative studies are imperative for understanding the evolution of adaptive neurobiological processes such as neural plasticity, cognition, and emotion. Previously we have reported that prolonged omission of expected rewards (OER, or 'frustrative nonreward') causes increased aggression in Atlantic salmon (Salmo salar). Here we report changes in brain monoaminergic activity and relative abundance of brain derived neurotrophic factor (BDNF) and dopamine receptor mRNA transcripts in the same paradigm. Groups of fish were initially conditioned to associate a flashing light with feeding. Subsequently, the expected food reward was delayed for 30 minutes during two out of three meals per day in the OER treatment, while the previously established routine was maintained in control groups. After 8 days there was no effect of OER on baseline brain stem serotonin (5-HT) or dopamine (DA) activity. Subsequent exposure to acute confinement stress led to increased plasma cortisol and elevated turnover of brain stem DA and 5-HT in all animals. The DA response was potentiated and DA receptor 1 (D1) mRNA abundance was reduced in the OER-exposed fish, indicating a sensitization of the DA system. In addition OER suppressed abundance of BDNF in the telencephalon of non-stressed fish. Regardless of OER treatment, a strong positive correlation between BDNF and D1 mRNA abundance was seen in non-stressed fish. This correlation was disrupted by acute stress, and replaced by a negative correlation between BDNF abundance and plasma cortisol concentration. These observations indicate a conserved link between DA, neurotrophin regulation, and corticosteroid-signaling pathways. The results also emphasize how fish models can be important tools in the study of neural plasticity and responsiveness to environmental unpredictability. PMID:24465595

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

    PubMed

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

    2009-01-01

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

  17. Anterior insula responds to temporally unpredictable aversiveness: an fMRI study.

    PubMed

    Shankman, Stewart A; Gorka, Stephanie M; Nelson, Brady D; Fitzgerald, Daniel A; Phan, K Luan; O'Daly, Owen

    2014-05-28

    A heightened sensitivity to unpredictable aversiveness is a key component of several anxiety disorders. Neuroimaging studies of unpredictable aversiveness have shown that the anterior region of the insula cortex (AIC) plays a central role in the anticipation of unpredictable aversiveness. The present study extended these findings by examining the role of the AIC in temporal unpredictability (i.e. not knowing when the stimulus will occur), a particularly critical aspect of unpredictability as it increases contextual anxiety and vigilance, given that the danger could happen 'at any time'. Nineteen healthy participants underwent functional MRI while anticipating either temporally unpredictable or predictable aversive (or neutral) images. Participants showed greater right AIC activation while anticipating unpredictable relative to predictable aversive images. In addition, activation in this region was correlated positively with self-reported individual differences in a key facet of intolerance of uncertainty (inhibitory behavior). Taken together, the present study suggests that the AIC plays an important role in the anticipation of temporally unpredictable aversiveness and may mediate key deficits in anxiety disorders. PMID:24614364

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

    PubMed Central

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

    2014-01-01

    Parasites play key ecological and evolutionary roles through the costs they impose on their host. In wild populations, the effect of parasitism is likely to vary considerably with environmental conditions, which may affect the availability of resources to hosts for defense. However, the interaction between parasitism and prevailing conditions is rarely quantified. In addition to environmental variation acting on hosts, individuals are likely to vary in their response to parasitism, and the combined effect of both may increase heterogeneity in host responses. Offspring hierarchies, established by parents in response to uncertain rearing conditions, may be an important source of variation between individuals. Here, we use experimental antiparasite treatment across 5 years of variable conditions to test how annual population productivity (a proxy for environmental conditions) and parasitism interact to affect growth and survival of different brood members in juvenile European shags (Phalacrocorax aristotelis). In control broods, last-hatched chicks had more plastic growth rates, growing faster in more productive years. Older siblings grew at a similar rate in all years. Treatment removed the effect of environment on last-hatched chicks, such that all siblings in treated broods grew at a similar rate across environmental conditions. There were no differences in nematode burden between years or siblings, suggesting that variation in responses arose from intrinsic differences between chicks. Whole-brood growth rate was not affected by treatment, indicating that within-brood differences were driven by a change in resource allocation between siblings rather than a change in overall parental provisioning. We show that gastrointestinal parasites can be a key component of offspring's developmental environment. Our results also demonstrate the value of considering prevailing conditions for our understanding of parasite effects on host life-history traits. Establishing how environmental conditions shape responses to parasitism is important as environmental variability is predicted to increase. PMID:25535557

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

    PubMed

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

    2014-09-01

    Parasites play key ecological and evolutionary roles through the costs they impose on their host. In wild populations, the effect of parasitism is likely to vary considerably with environmental conditions, which may affect the availability of resources to hosts for defense. However, the interaction between parasitism and prevailing conditions is rarely quantified. In addition to environmental variation acting on hosts, individuals are likely to vary in their response to parasitism, and the combined effect of both may increase heterogeneity in host responses. Offspring hierarchies, established by parents in response to uncertain rearing conditions, may be an important source of variation between individuals. Here, we use experimental antiparasite treatment across 5 years of variable conditions to test how annual population productivity (a proxy for environmental conditions) and parasitism interact to affect growth and survival of different brood members in juvenile European shags (Phalacrocorax aristotelis). In control broods, last-hatched chicks had more plastic growth rates, growing faster in more productive years. Older siblings grew at a similar rate in all years. Treatment removed the effect of environment on last-hatched chicks, such that all siblings in treated broods grew at a similar rate across environmental conditions. There were no differences in nematode burden between years or siblings, suggesting that variation in responses arose from intrinsic differences between chicks. Whole-brood growth rate was not affected by treatment, indicating that within-brood differences were driven by a change in resource allocation between siblings rather than a change in overall parental provisioning. We show that gastrointestinal parasites can be a key component of offspring's developmental environment. Our results also demonstrate the value of considering prevailing conditions for our understanding of parasite effects on host life-history traits. Establishing how environmental conditions shape responses to parasitism is important as environmental variability is predicted to increase. PMID:25535557

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

    PubMed

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

    2014-02-01

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

  1. Temporally Unpredictable Sounds Exert a Context-Dependent Influence on Evaluation of Unrelated Images

    PubMed Central

    Bach, Dominik R.; Seifritz, Erich; Dolan, Raymond J.

    2015-01-01

    Temporally unpredictable stimuli influence murine and human behaviour, as previously demonstrated for sequences of simple sounds with regular or irregular onset. It is unknown whether this influence is mediated by an evaluation of the unpredictable sound sequences themselves, or by an interaction with task context. Here, we find that humans evaluate unrelated neutral pictures as more negative when these are presented together with a temporally unpredictable sound sequence, compared to a predictable sequence. The same is observed for evaluation of neutral, angry and fearful face photographs. Control experiments suggest this effect is specific to interspersed presentation of negative and neutral visual stimuli. Unpredictable sounds presented on their own were evaluated as more activating, but not more aversive, and were preferred over predictable sounds. When presented alone, these sound sequences also did not elicit tonic autonomic arousal or negative mood change. We discuss how these findings might account for previous data on the effects of unpredictable sounds, in humans and rodents. PMID:26098105

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  3. The aetiopathogenesis of fatigue: unpredictable, complex and persistent

    PubMed Central

    Clark, James E.; Fai Ng, W.; Watson, Stuart; Newton, Julia L.

    2016-01-01

    Background Chronic fatigue syndrome is a common condition characterized by severe fatigue with post-exertional malaise, impaired cognitive ability, poor sleep quality, muscle pain, multi-joint pain, tender lymph nodes, sore throat or headache. Its defining symptom, fatigue is common to several diseases. Areas of agreement Research has established a broad picture of impairment across autonomic, endocrine and inflammatory systems though progress seems to have reached an impasse. Areas of controversy The absence of a clear consensus view of the pathophysiology of fatigue suggests the need to switch from a focus on abnormalities in one system to an experimental and clinical approach which integrates findings across multiple systems and their constituent parts and to consider multiple environmental factors. Growing points We discuss this with reference to three key factors, non-determinism, non-reductionism and self-organization and suggest that an approach based on these principles may afford a coherent explanatory framework for much of the observed phenomena in fatigue and offers promising avenues for future research. Areas timely for developing research By adopting this approach, the field can examine issues regarding aetiopathogenesis and treatment, with relevance for future research and clinical practice. PMID:26872857

  4. Intrusions of a drowsy mind: neural markers of phenomenological unpredictability

    PubMed Central

    Noreika, Valdas; Canales-Johnson, Andrés; Koh, Justin; Taylor, Mae; Massey, Irving; Bekinschtein, Tristan A.

    2015-01-01

    The transition from a relaxed to a drowsy state of mind is often accompanied by hypnagogic experiences: most commonly, perceptual imagery, but also linguistic intrusions, i.e., the sudden emergence of unpredictable anomalies in the stream of inner speech. This study has sought to describe the contents of such intrusions, to verify their association with the progression of sleep onset, and to investigate the electroencephalographic processes associated with linguistic intrusions as opposed to more common hypnagogic perceptual imagery. A single participant attended 10 experimental sessions in the EEG laboratory, where he was allowed to drift into a drowsy state of mind, while maintaining metacognition of his own experiences. Once a linguistic intrusion or a noticeable perceptual image occurred, the participant pressed a button and reported it verbally. An increase in the EEG-defined depth of drowsiness as assessed by the Hori system of sleep onset was observed in the last 20 s before a button press. Likewise, EEG Dimension of Activation values decreased before the button press, indicating that the occurrence of cognitively incongruous experiences coincides with the rapid change of EEG predictability patterns. EEG hemispheric asymmetry analysis showed that linguistic intrusions had a higher alpha and gamma power in the left hemisphere electrodes, whereas perceptual imagery reports were associated with a higher beta power over the right hemisphere. These findings indicate that the modality as well as the incongruence of drowsiness-related hypnagogic experiences is strongly associated with distinct EEG signatures in this participant. Sleep onset may provide a unique possibility to study the neural mechanisms accompanying the fragmentation of the stream of consciousness in healthy individuals. PMID:25814962

  5. Adapting to the unpredictable: reproductive biology of vertebrates in the Australian wet-dry tropics.

    PubMed

    Shine, Richard; Brown, Gregory P

    2008-01-27

    In the wet-dry tropics of northern Australia, temperatures are high and stable year-round but monsoonal rainfall is highly seasonal and variable both annually and spatially. Many features of reproduction in vertebrates of this region may be adaptations to dealing with this unpredictable variation in precipitation, notably by (i) using direct proximate (rainfall-affected) cues to synchronize the timing and extent of breeding with rainfall events, (ii) placing the eggs or offspring in conditions where they will be buffered from rainfall extremes, and (iii) evolving developmental plasticity, such that the timing and trajectory of embryonic differentiation flexibly respond to local conditions. For example, organisms as diverse as snakes (Liasis fuscus, Acrochordus arafurae), crocodiles (Crocodylus porosus), birds (Anseranas semipalmata) and wallabies (Macropus agilis) show extreme annual variation in reproductive rates, linked to stochastic variation in wet season rainfall. The seasonal timing of initiation and cessation of breeding in snakes (Tropidonophis mairii) and rats (Rattus colletti) also varies among years, depending upon precipitation. An alternative adaptive route is to buffer the effects of rainfall variability on offspring by parental care (including viviparity) or by judicious selection of nest sites in oviparous taxa without parental care. A third type of adaptive response involves flexible embryonic responses (including embryonic diapause, facultative hatching and temperature-dependent sex determination) to incubation conditions, as seen in squamates, crocodilians and turtles. Such flexibility fine-tunes developmental rates and trajectories to conditions--especially, rainfall patterns--that are not predictable at the time of oviposition. PMID:17638689

  6. Environmental performance of wastewater reuse systems: impact of system boundaries and external conditions.

    PubMed

    Baresel, Christian; Dalgren, Lena; Almemark, Mats; Lazic, Aleksandra

    2016-01-01

    Wastewater reclamation will be a significant part of future water management and the environmental assessment of various treatment systems to reuse wastewater has become an important research field. The secondary treatment process and sludge handling on-site are, especially, electricity demanding processes due to aeration, pumping, mixing, dewatering, etc. used for operation and are being identified as the main contributor for many environmental impacts. This study discusses how the environmental performance of reuse treatment systems may be influenced by surrounding conditions. This article illustrates and discusses the importance of factors commonly treated as externalities and as such not being included in optimization strategies of reuse systems, but that are necessary to environmentally assess wastewater reclamation systems. This is illustrated by two up-stream and downstream processes; electricity supply and the use of sludge as fertilizer commonly practiced in regions considered for wastewater reclamation. The study shows that external conditions can have a larger impact on the overall environmental performance of reuse treatment systems than internal optimizations could compensate for. These results imply that a more holistic environmental assessment of reuse schemes could provide less environmental impacts as externalities could be included in measures to reduce the overall impacts. PMID:27003080

  7. Does Environmental Heterogeneity Promote Cognitive Abilities?

    PubMed

    González-Gómez, Paulina L; Razeto-Barry, Pablo; Araya-Salas, Marcelo; Estades, Cristian F

    2015-09-01

    In the context of global change the possible loss of biodiversity has been identified as a major concern. Biodiversity could be seriously threatened as a direct consequence of changes in availability of food, changing thermal conditions, and loss and fragmentation of habitat. Considering the magnitude of global change, an understanding of the mechanisms involved in coping with a changing environment is urgent. We explore the hypothesis that species and individuals experiencing highly variable environments are more likely to develop a wider range of responses to handle the different and unpredictable conditions imposed by global change. In the case of vertebrates, the responses to the challenges imposed by unpredictable perturbations ultimately are linked to cognitive abilities allowing the solving of problems, and the maximization of energy intake. Our models were hummingbirds, which offer a particularly compelling group in which to examine the functional and mechanistic links between behavioral and energetic strategies in individuals experiencing different degrees of social and environmental heterogeneity. PMID:26082484

  8. ENVIRONMENTAL CONDITIONS MODULATE NEUROTOXIC EFFECTS OF PSYCHOMOTOR STIMULANT DRUGS OF ABUSE

    PubMed Central

    Kiyatkin, Eugene A.; Sharma, Hari S.

    2013-01-01

    Psychomotor stimulants such as methamphetamine (METH), amphetamine, and 3,4-Metylenedioxymethamphetamine (MDMA or ecstasy) are potent addictive drugs. While it is known that their abuse could result in adverse health complications, including neurotoxicity, both the environmental conditions and activity states associated with their intake could strongly enhance drug toxicity, often resulting in life-threatening health complications. In this review we analyze results of animal experiments that suggest that even moderate increases in environmental temperatures and physiological activation, the conditions typical of human raves parties, dramatically potentiate brain hyperthermic effects of METH and MDMA. We demonstrate that METH also induces breakdown of the blood-brain barrier (BBB), acute glial activation, brain edema, and structural abnormalities of various subtypes of brain cells; these effects are also strongly enhanced when the drug is used at moderately warm environmental conditions. We consider the mechanisms underlying environmental modulation of acute drug neurotoxicity and focus on the role of brain temperature, a critical homeostatic parameter that could be affected by metabolism-enhancing drugs and environmental conditions and affect neural activity and functions. PMID:22748829

  9. Environmental Condition and its Impact on Landscape Description by Salient Element

    NASA Astrophysics Data System (ADS)

    Soleimani, S.; Malek, M. R.; Soleimani, Z.; Arabsheibani, R.

    2015-12-01

    Describing a landscape means making link between concepts of visible features and people's perception. Most landscape description methods underline salient entities which are a key trigger for wayfinding problems and tourism management. Searching for a better understanding of landscape descriptions implies to explore and identify the main visual properties that differentiate between landscapes depending on both human cognition and environmental condition. Furthermore, this environmental condition affects the credibility of data produced by people, particularly when using Volunteered Geographical Information systems which brings forward a huge amount of information. Then this paper proposes an approach to emerge patterns by which describing landscape in general and choosing salient objects in particular have been influenced.

  10. Resistance of bioparticles formed of phosphate-accumulating bacteria and zeolite to harsh environmental conditions.

    PubMed

    Ivankovic, Tomislav; Hrenovic, Jasna; Matonickin-Kepcija, Renata

    2013-01-01

    Extreme environmental conditions, such as pH fluctuations, high concentrations of toxicants or grazing of protozoa, can potentially be found in wastewater treatment systems. This study was carried out to provide specific evidence on how 'bioparticles' can resist these conditions. The term 'bioparticle' is used to describe a particle comprising natural zeolitized tuff with a developed biofilm of the phosphate-accumulating bacterial species, Acinetobacter junii, on the surface. The bacteria in the biofilm were protected from the negative influence of extremely low pH, high concentrations of benzalkonium-chloride and grazing by Paramecium caudatum and Euplotes affinis, even under conditions that caused complete eradication of planktonic bacteria. During an incubation of 24?h, the biofilms were maintained and bacteria detached from the bioparticles, thus bioaugmenting the wastewater. The bioparticles provided a safe environment for the survival of bacteria in harsh environmental conditions and could be used for successful bioaugmentation in wastewater treatment plants. PMID:23706006

  11. The behavioural and physiological strategies of bird and reptile embryos in response to unpredictable variation in nest temperature.

    PubMed

    Du, Wei-Guo; Shine, Richard

    2015-02-01

    Temperature profoundly affects the rate and trajectory of embryonic development, and thermal extremes can be fatal. In viviparous species, maternal behaviour and physiology can buffer the embryo from thermal fluctuations; but in oviparous animals (like most reptiles and all birds), an embryo is likely to encounter unpredictable periods when incubation temperatures are unfavourable. Thus, we might expect natural selection to have favoured traits that enable embryos to maintain development despite those fluctuations. Our review of recent research identifies three main routes that embryos use in this way. Extreme temperatures (i) can be avoided (e.g. by accelerating hatching, by moving within the egg, by cooling the egg by enhanced rates of evaporation, or by hysteresis in rates of heating versus cooling); (ii) can be tolerated (e.g. by entering diapause, by producing heat-shock proteins, or by changing oxygen use); or (iii) the embryo can adjust its physiology and/or developmental trajectory in ways that reduce the fitness penalties of unfavourable thermal conditions (e.g. by acclimating, by exploiting brief windows of favourable conditions, or by producing the hatchling phenotype best suited to those incubation conditions). Embryos are not simply passive victims of ambient conditions. Like free-living stages of the life cycle, embryos exhibit behavioural and physiological plasticity that enables them to deal with unpredictable abiotic challenges. PMID:24593133

  12. Environmental Transmission Electron Microscopy Study of Diesel Carbon Soot Combustion under Simulated Catalytic-Reaction Conditions.

    PubMed

    Mori, Kohsuke; Watanabe, Keitaro; Sato, Takeshi; Yamashita, Hiromi

    2015-05-18

    Environmental transmission electron microscopy (ETEM) is used to monitor the catalytic combustion of diesel carbon soot upon exposure to molecular oxygen at elevated temperatures by using a gas-injection specimen heating holder. The reaction conditions simulated in the ETEM experiments reconstruct real conditions effectively. This study demonstrated for the first time that soot combustion occurs at the soot-catalyst interface for both Ag/CeO2 and Cu/BaO/La2 O3 catalysts. PMID:25603930

  13. The Influence of Causal Explanations and Diagnostic Labeling on Psychology Students' Beliefs About Treatments, Prognosis, Dangerousness and Unpredictability in Schizophrenia.

    PubMed

    Magliano, Lorenza; Read, John; Rinaldi, Angela; Costanzo, Regina; De Leo, Renata; Schioppa, Giustina; Petrillo, Miriam

    2016-04-01

    This study explored views of 566 Italian psychology students about schizophrenia. The most frequently cited causes were psychological traumas (68 %) and heredity (54 %). Thirty-three percent of students firmly believed that people with the condition could recover. Reporting heredity among the causes, and identifying schizophrenia were both associated with prognostic pessimism, greater confidence in pharmacological treatments and lower confidence in psychological treatments. Schizophrenia labeling was also associated with higher perception of unpredictability and dangerousness. Compared to first year students, fourth/fifth year students more frequently reported heredity among the causes, and were more pessimistic about schizophrenia recovery. Stigma topics should be included in future psychologists' education. PMID:26081981

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

    PubMed

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

    2012-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    SciTech Connect

    Vitiello, F.; Borfecchia, F.; De Cecco, L.; Martini, S.

    1997-08-01

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

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

    ERIC Educational Resources Information Center

    Meyer, Calvin F.; Benson, Robert T.

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

  18. 76 FR 59481 - Fifty Eighth Meeting: RTCA Special Committee 135, Environmental Conditions and Test Procedures...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-26

    ... and Test Procedures for Airborne Equipment AGENCY: Federal Aviation Administration (FAA), Department... and Test Procedures for Airborne Equipment. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 135: Environmental Conditions and Test Procedures...

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

    ERIC Educational Resources Information Center

    Teather, Lisa A.; Wurtman, Richard J.

    2005-01-01

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

  20. EVALUATION OF SEVERAL ASSESSMENT METHODS AS INDICATORS OF ESTUARINE ENVIRONMENTAL CONDITIONS

    EPA Science Inventory

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

  1. Ebola Virus RNA Stability in Human Blood and Urine in West Africa’s Environmental Conditions

    PubMed Central

    Delaune, Deborah; Poyot, Thomas; Valade, Eric; Mérens, Audrey; Rollin, Pierre E.; Foissaud, Vincent

    2016-01-01

    We evaluated RNA stability of Ebola virus in EDTA blood and urine samples collected from infected patients and stored in West Africa’s environmental conditions. In blood, RNA was stable for at least 18 days when initial cycle threshold values were <30, but in urine, RNA degradation occurred more quickly. PMID:26812135

  2. Environmental and genetic variation of soflavone content under Brazil growing conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  3. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.161-00 Air... conditioning compressor while operating on a specific driving cycle. The environmental facility control... average of 100 ±5 grains of water/pound of dry air. (2) Humidity is recorded continuously at a minimum...

  4. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.161-00 Air... conditioning compressor while operating on a specific driving cycle. The environmental facility control... average of 100 ±5 grains of water/pound of dry air. (2) Humidity is recorded continuously at a minimum...

  5. 40 CFR 86.161-00 - Air conditioning environmental test facility ambient requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Light-Duty Trucks and New Otto-Cycle Complete Heavy-Duty Vehicles; Test Procedures § 86.161-00 Air... conditioning compressor while operating on a specific driving cycle. The environmental facility control... average of 100 ±5 grains of water/pound of dry air. (2) Humidity is recorded continuously at a minimum...

  6. Ebola Virus RNA Stability in Human Blood and Urine in West Africa's Environmental Conditions.

    PubMed

    Janvier, Frédéric; Delaune, Deborah; Poyot, Thomas; Valade, Eric; Mérens, Audrey; Rollin, Pierre E; Foissaud, Vincent

    2016-02-01

    We evaluated RNA stability of Ebola virus in EDTA blood and urine samples collected from infected patients and stored in West Africa's environmental conditions. In blood, RNA was stable for at least 18 days when initial cycle threshold values were <30, but in urine, RNA degradation occurred more quickly. PMID:26812135

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

    PubMed

    Kring, David A

    2003-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Kring, David A.

    2003-01-01

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

  9. Real-time process control techniques for a system with unpredictable disturbances

    SciTech Connect

    O`Shaughnessy, P.T.

    1995-12-31

    The development of a feedback control system to maintain a desired concentration of an aerosol in an environmental chamber is discussed. System components include: a stepper-motor-driven dust generator connected by the serial port to a host computerl and an aerosol monitor connected to an analog-to-digital (A/D) converter in the computer capable of transmitting a voltage signal proportional to concentration. Uncontrolled trials revealed highly correlated concentration levels that exhibited unpredictable disturbances and tended to wander significantly off target. The automatic control system contained an expotentially weighted moving average (EWMA) algorithm, developed for use with correlated data, to both smooth the concentration readings near some average value and create control limits that vary over time. Control action was taken when either limit reached the setpoint by manipulating the dust generator output rate. This approach reduced the number of control actions needed to maintain the process near the setpoint and avoided unnecessary corrections when sudden, but short-lived, disturbances affected the system.

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

    PubMed Central

    Galloway, Aaron W. E.; Winder, Monika

    2015-01-01

    Essential fatty acids (EFA), which are primarily generated by phytoplankton, limit growth and reproduction in diverse heterotrophs. The biochemical composition of phytoplankton is well-known to be governed both by phylogeny and environmental conditions. Nutrients, light, salinity, and temperature all affect both phytoplankton growth and fatty acid composition. However, the relative importance of taxonomy and environment on algal fatty acid content has yet to be comparatively quantified, thus inhibiting predictions of changes to phytoplankton food quality in response to global environmental change. We compiled 1145 published marine and freshwater phytoplankton fatty acid profiles, consisting of 208 species from six major taxonomic groups, cultured in a wide range of environmental conditions, and used a multivariate distance-based linear model to quantify the total variation explained by each variable. Our results show that taxonomic group accounts for 3-4 times more variation in phytoplankton fatty acids than the most important growth condition variables. The results underscore that environmental conditions clearly affect phytoplankton fatty acid profiles, but also show that conditions account for relatively low variation compared to phylogeny. This suggests that the underlying mechanism determining basal food quality in aquatic habitats is primarily phytoplankton community composition, and allows for prediction of environmental-scale EFA dynamics based on phytoplankton community data. We used the compiled dataset to calculate seasonal dynamics of long-chain EFA (LCEFA; ≥C20 ɷ-3 and ɷ-6 polyunsaturated fatty acid) concentrations and ɷ-3:ɷ-6 EFA ratios in Lake Washington using a multi-decadal phytoplankton community time series. These analyses quantify temporal dynamics of algal-derived LCEFA and food quality in a freshwater ecosystem that has undergone large community changes as a result of shifting resource management practices, highlighting diatoms, cryptophytes and dinoflagellates as key sources of LCEFA. Moreover, the analyses indicate that future shifts towards cyanobacteria-dominated communities will result in lower LCEFA content in aquatic ecosystems. PMID:26076015

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

    PubMed

    Galloway, Aaron W E; Winder, Monika

    2015-01-01

    Essential fatty acids (EFA), which are primarily generated by phytoplankton, limit growth and reproduction in diverse heterotrophs. The biochemical composition of phytoplankton is well-known to be governed both by phylogeny and environmental conditions. Nutrients, light, salinity, and temperature all affect both phytoplankton growth and fatty acid composition. However, the relative importance of taxonomy and environment on algal fatty acid content has yet to be comparatively quantified, thus inhibiting predictions of changes to phytoplankton food quality in response to global environmental change. We compiled 1145 published marine and freshwater phytoplankton fatty acid profiles, consisting of 208 species from six major taxonomic groups, cultured in a wide range of environmental conditions, and used a multivariate distance-based linear model to quantify the total variation explained by each variable. Our results show that taxonomic group accounts for 3-4 times more variation in phytoplankton fatty acids than the most important growth condition variables. The results underscore that environmental conditions clearly affect phytoplankton fatty acid profiles, but also show that conditions account for relatively low variation compared to phylogeny. This suggests that the underlying mechanism determining basal food quality in aquatic habitats is primarily phytoplankton community composition, and allows for prediction of environmental-scale EFA dynamics based on phytoplankton community data. We used the compiled dataset to calculate seasonal dynamics of long-chain EFA (LCEFA; ?C20 ?-3 and ?-6 polyunsaturated fatty acid) concentrations and ?-3:?-6 EFA ratios in Lake Washington using a multi-decadal phytoplankton community time series. These analyses quantify temporal dynamics of algal-derived LCEFA and food quality in a freshwater ecosystem that has undergone large community changes as a result of shifting resource management practices, highlighting diatoms, cryptophytes and dinoflagellates as key sources of LCEFA. Moreover, the analyses indicate that future shifts towards cyanobacteria-dominated communities will result in lower LCEFA content in aquatic ecosystems. PMID:26076015

  12. The effects of environmental enrichment on nicotine condition place preference in male rats.

    PubMed

    Ewin, Sarah E; Kangiser, Megan M; Stairs, Dustin J

    2015-10-01

    Environmental enrichment has previously been shown to alter sensitivity to psychostimulants and opiates in various preclinical models. However, little research has been conducted studying the effects of environmental enrichment on the more commonly abused drug, nicotine. The current study raised male rats in either enriched conditions (EC) or isolated conditions (IC) and tested the animals' sensitivity to acquisition, extinction and reinstatement of nicotine conditioned place preference (CPP). Using a 3-chamber CPP apparatus, male Sprague-Dawley rats were conditioned with 1 of 3 doses of nicotine (0.4, 0.6, and 0.8 mg/kg) or saline on alternating days across 8 conditioning trials, followed by a test day for a nicotine-induced CPP response. Next, the animals had 5 extinction sessions followed by a nicotine-primed reinstatement session. EC rats displayed nicotine CPP at all 3 doses, whereas IC rats failed to show significant nicotine CPP relative to saline controls. EC rats also showed extinction of the nicotine-induced CPP response by the fifth extinction session for all 3 nicotine doses tested. However, only the 2 highest doses of the nicotine prime reinstated a CPP response in EC rats relative to saline controls. Taken together, these findings suggest that environmental enrichment may increase sensitivity to the rewarding effects of nicotine. PMID:26167715

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

    USGS Publications Warehouse

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

    2002-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Biryukov, Mikhail; Dippold, Michaela; Kuzyakov, Yakov

    2014-05-01

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

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

    NASA Astrophysics Data System (ADS)

    Baptista, V.; Leitão, F.

    2014-02-01

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

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

    SciTech Connect

    Bassow, S.L.; Bazzaz, F.A.

    1998-12-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  18. Oil Recovery from Water under Environmentally Relevant Conditions Using Magnetic Nanoparticles.

    PubMed

    Mirshahghassemi, Seyyedali; Lead, Jamie R

    2015-10-01

    Large oil spills and oily wastewater discharges from ships and industrial activities can have serious impacts on the environment with potentially major economic impacts. Current oil remediation techniques are inefficient and may have deleterious environmental consequences. However, nanotechnology offers a new route to potentially remediate oil pollution. In this study, a cheap and facile hydrothermal method was developed to synthesize polyvinylpyrrolidone-coated magnetite nanoparticles to separate a reference MC252 oil from oil-water mixture under environmentally relevant conditions. Fluorescence and Proton nuclear magnetic resonance spectroscopy results showed near 100% oil removal from oil-water mixture in the ultrapure water under optimum condition. Based on gas chromatography-mass spectrometry data, approximately 100% of lower molecular mass alkanes (C9-C21) were removed within 10 min of magnetic separation and by increasing the separation time to 40 min, greater than 67% of C22-25 alkanes were removed. Moreover, nanoparticles removed near 100% oil from synthetic seawater solutions in the presence and absence of fulvic acid showing excellent oil removal capacity of the nanoparticles under different conditions. Results show that these nanoparticles can be utilized to remove oil over a short time with a high removal efficiency under environmentally relevant conditions. PMID:26358198

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

    USGS Publications Warehouse

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

    2012-01-01

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

  20. Accounting for Variable Environmental Conditions in Time-Lapse Electrical Resistivity Images

    NASA Astrophysics Data System (ADS)

    Bentley, L. R.; Gharibi, M.; Hayley, K.

    2006-05-01

    Time-lapse electrical resistivity imaging (ERI) is being used to monitor salt transport at a remediation site in Alberta, Canada. The goal is to use ERI to produce images of salt concentration in soil. Mapping the salt concentration is possible because soil electrical conductivity (EC) is strongly correlated with salt concentration. However, soil EC is also affected by the temperature of the soil and the soil moisture content. Temperature and soil moisture conditions vary with changing environmental conditions. Three-D ERI results show that dramatically incorrect interpretations will result by neglecting differences in environmental conditions at the time of surveys. These results have two important implications 1) the petrophysical relationship that maps ERI values to salt concentration must be applied to images that have been converted to a standard condition equivalent EC value, and 2) auxiliary field measurements are required to establish temperature and saturation profiles at the time of surveys. We have chosen to standardize our images to 6 Deg. C and saturation of 1 because these values are most representative of the average conditions at the site. Laboratory measurements show that the temperature correction is 3.0% EC per Deg. C. The Waxman-Smits equation is used to correct for saturation differences. Finally, laboratory measurements have established an empirical relationship between soil EC at standard conditions and the regulatory measure of soil paste EC.

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

    PubMed Central

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

    2015-01-01

    In social groups, individuals' dominance rank, social bonds, and kinship with other group members have been shown to influence their foraging behavior. However, there is growing evidence that the particular effects of these social traits may also depend on local environmental conditions. We investigated this by comparing the foraging behavior of wild chacma baboons, Papio ursinus, under natural conditions and in a field experiment where food was spatially clumped. Data were collected from 55 animals across two troops over a 5-month period, including over 900 agonistic foraging interactions and over 600 food patch visits in each condition. In both conditions, low-ranked individuals received more agonism, but this only translated into reduced foraging performances for low-ranked individuals in the high-competition experimental conditions. Our results suggest one possible reason for this pattern may be low-ranked individuals strategically investing social effort to negotiate foraging tolerance, but the rank-offsetting effect of this investment being overwhelmed in the higher-competition experimental environment. Our results also suggest that individuals may use imbalances in their social bonds to negotiate tolerance from others under a wider range of environmental conditions, but utilize the overall strength of their social bonds in more extreme environments where feeding competition is more intense. These findings highlight that behavioral tactics such as the strategic investment of social effort may allow foragers to mitigate the costs of low rank, but that the effectiveness of these tactics is likely to be limited in certain environments. PMID:25691973

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

    PubMed

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

    2003-12-30

    Bacteria develop a number of devices for sensing, responding, and adapting to different environmental conditions. Understanding within a genomic perspective how the transcriptional machinery of bacteria is modulated, as a response for changing conditions, is a major challenge for biologists. Knowledge of which genes are turned on or turned off under specific conditions is essential for our understanding of cell behavior. In this study we describe how the information pertaining to gene expression and associated growth conditions (even with very little knowledge of the associated regulatory mechanisms) is gathered from the literature and incorporated into RegulonDB, a database on transcriptional regulation and operon organization in E. coli. The link between growth conditions, signal transduction, and transcriptional regulation is modeled in the database in a simple format that highlights biological relevant information. As far as we know, there is no other database that explicitly clarifies the effect of environmental conditions on gene transcription. We discuss how this knowledge constitutes a benchmark that will impact future research aimed at integration of regulatory responses in the cell; for instance, analysis of microarrays, predicting culture behavior in biotechnological processes, and comprehension of dynamics of regulatory networks. This integrated knowledge will contribute to the future goal of modeling the behavior of E. coli as an entire cell. The RegulonDB database can be accessed on the web at the URL: http://www.cifn.unam.mx/Computational_Biology/regulondb/. PMID:14708114

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

    SciTech Connect

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

    1995-12-31

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

  4. Neuroprotective Role of Intermittent Hypobaric Hypoxia in Unpredictable Chronic Mild Stress Induced Depression in Rats

    PubMed Central

    Deep, Satayanarayan; Prasad, Dipti; Singh, Shashi Bala; Khan, Nilofar

    2016-01-01

    Hypoxic exposure results in several pathophysiological conditions associated with nervous system, these include acute and chronic mountain sickness, loss of memory, and high altitude cerebral edema. Previous reports have also suggested the role of hypoxia in pathogenesis of depression and related psychological conditions. On the other hand, sub lethal intermittent hypoxic exposure induces protection against future lethal hypoxia and may have beneficial effect. Therefore, the present study was designed to explore the neuroprotective role of intermittent hypobaric hypoxia (IHH) in Unpredictable Chronic Mild Stress (UCMS) induced depression like behaviour in rats. The IHH refers to the periodic exposures to hypoxic conditions interrupted by the normoxic or lesser hypoxic conditions. The current study examines the effect of IHH against UCMS induced depression, using elevated plus maze (EPM), open field test (OFT), force swim test (FST), as behavioural paradigm and related histological and molecular approaches. The data indicated the UCMS induced depression like behaviour as evident from decreased exploration activity in OFT with increased anxiety levels in EPM, and increased immobility time in the FST; whereas on providing the IHH (5000m altitude, 4hrs/day for two weeks) these behavioural changes were ameliorated. The morphological and molecular studies also validated the neuroprotective effect of IHH against UCMS induced neuronal loss and decreased neurogenesis. Here, we also explored the role of Brain-Derived Neurotrophic Factor (BDNF) in anticipatory action of IHH against detrimental effect of UCMS as upon blocking of BDNF-TrkB signalling the beneficial effect of IHH was nullified. Taken together, the findings of our study demonstrate that the intermittent hypoxia has a therapeutic potential similar to an antidepressant in animal model of depression and could be developed as a preventive therapeutic option against this pathophysiological state. PMID:26901349

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

    PubMed Central

    Kim, Minseung; Zorraquino, Violeta; Tagkopoulos, Ilias

    2015-01-01

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

  6. Quantifying the effects of seed arrival and environmental conditions on tropical seedling community structure.

    PubMed

    Paine, C E Timothy; Harms, Kyle E

    2009-05-01

    Though it is recognized that both stochastic and deterministic processes structure all communities, empirical assessments of their relative importance are rare, particularly within any single community. In this paper, we quantify the dynamic effects of dispersal assembly and niche assembly on the seedling layer in a diverse neotropical rain forest. The two theories make divergent predictions regarding the roles of seed arrival and environmental heterogeneity in generating community structure. Put simply, dispersal assembly posits that the stochasticity inherent to seed arrival structures communities, whereas niche assembly suggests that heterogeneity in post-dispersal environmental conditions is more important. We experimentally sowed 15,132 seeds of eight tree species at varying levels of density and diversity. Every six months we censused the seedlings that germinated and assessed the abiotic and biotic conditions of each plot. We assessed the density, diversity, and species composition of three nested subsets of the seedling layer: seedlings germinated from sown seeds, all seedlings germinated between July 2003 and 2004, and all woody seedlings. We partitioned the variance in density and diversity of each subset of the seedling layer into components representing seed-addition treatments and environmental conditions at 6- to 12-month intervals. Seed additions initially explained more variance in the density and diversity than did environmental heterogeneity for seven of eight sown species, but explained little variance in the density or diversity of the entire seedling layer. Species composition was better explained by seed-addition treatments than by environmental heterogeneity for all three subsets and in all time periods. Nevertheless, the variance in community structure explained by seed-addition treatments declined over the two years following germination, presaging shifts in the relative importance of dispersal assembly and niche assembly. Our study quantifies how dispersal assembly and niche assembly may vary among the components of an ecological community and shift dynamically through time. PMID:19142667

  7. The ammonium excretion of the shore crab, carcinus maenas, in relation to environmental osmotic conditions

    NASA Astrophysics Data System (ADS)

    Spaargaren, D. H.

    Ammonia concentrations were measured in blood and external media of shore crabs, Carcinus maenas, acclimated to 6 different salinities at high (20° C) and low (4° C) temperatures. It is seen that environmental osmotic conditions (temperature and salinity) have a major influence on NH 4+ formation and thus on protein (amino acid) catabolism. Blood ammonia concentrations appear to be strongly stabilized, independent of environmental osmotic conditions, ranging between 0.25 and 0.55 mmol·l -1. At normal, low environmental NH 4+ concentrations blood NH 4+ is strongly hyper-ionic compared to external concentrations; at high environmental NH 4+ concentrations (even when artificially raised to 2.5 mmol·l -1), blood NH 4+ is strongly hypo-ionic. Regulation of the blood NH 4+ concentrations takes place by a variable efflux of NH 4+; at high environmental NH 4+ concentrations (> 0.28 mmol · l -1), in addition to a high NH 4+ efflux, stabilization of the blood NH 4+ concentrations is effectuated by the formation of urea. Ammonia efflux to the surrounding water is highly dependent to the osmotic conditions of the environment: viz. positively related to temperature and inversely related to external salinity, with relatively stable value near the isosmotic salinity. Related to the strong variations in ammonia efflux, external NH 4+ concentrations in a closed volume of water are highly variable. In the course of time very high values develop in media of low salinity at high temperature. A close connection between NH 4+ excretion and extracellular ion regulation is indicated.

  8. Investigating the genetic architecture of conditional strategies using the environmental threshold model.

    PubMed

    Buzatto, Bruno A; Buoro, Mathieu; Hazel, Wade N; Tomkins, Joseph L

    2015-12-22

    The threshold expression of dichotomous phenotypes that are environmentally cued or induced comprise the vast majority of phenotypic dimorphisms in colour, morphology, behaviour and life history. Modelled as conditional strategies under the framework of evolutionary game theory, the quantitative genetic basis of these traits is a challenge to estimate. The challenge exists firstly because the phenotypic expression of the trait is dichotomous and secondly because the apparent environmental cue is separate from the biological signal pathway that induces the switch between phenotypes. It is the cryptic variation underlying the translation of cue to phenotype that we address here. With a 'half-sib common environment' and a 'family-level split environment' experiment, we examine the environmental and genetic influences that underlie male dimorphism in the earwig Forficula auricularia. From the conceptual framework of the latent environmental threshold (LET) model, we use pedigree information to dissect the genetic architecture of the threshold expression of forceps length. We investigate for the first time the strength of the correlation between observable and cryptic 'proximate' cues. Furthermore, in support of the environmental threshold model, we found no evidence for a genetic correlation between cue and the threshold between phenotypes. Our results show strong correlations between observable and proximate cues and less genetic variation for thresholds than previous studies have suggested. We discuss the importance of generating better estimates of the genetic variation for thresholds when investigating the genetic architecture and heritability of threshold traits. By investigating genetic architecture by means of the LET model, our study supports several key evolutionary ideas related to conditional strategies and improves our understanding of environmentally cued decisions. PMID:26674955

  9. Food web expansion and contraction in response to changing environmental conditions.

    PubMed

    Tunney, Tyler D; McCann, Kevin S; Lester, Nigel P; Shuter, Brian J

    2012-01-01

    Macroscopic ecosystem properties, such as major material pathways and community biomass structure, underlie the ecosystem services on which humans rely. While ecologists have long sought to identify the determinants of the trophic height of food webs (food chain length), it is somewhat surprising how little research effort is invested in understanding changes among other food web properties across environmental conditions. Here we theoretically and empirically show how a suite of fundamental macroscopic food web structures respond, in concert, to changes in habitat accessibility using post-glacial lakes as model ecosystems. We argue that as resource accessibility increases in coupled food webs, food chain length contracts (that is, reduced predator trophic position), habitat coupling expands (that is, increasingly coupled macrohabitats) and biomass pyramid structure becomes more top heavy. Our results further support an emerging theoretical view of flexible food webs that provides a foundation for generally understanding ecosystem responses to changing environmental conditions. PMID:23033081

  10. Environmental Conditions Influence Allometric Patterns in the Blow Fly, Chrysomya albiceps

    PubMed Central

    Horenstein, M Battán; Peretti, Av

    2011-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

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

    PubMed

    Floridou, Georgia A; Müllensiefen, Daniel

    2015-05-01

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

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

    PubMed

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

    2013-01-01

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

  14. Creep and Environmental Durability of EBC/CMCs Under Imposed Thermal Gradient Conditions

    NASA Technical Reports Server (NTRS)

    Appleby, Matthew; Morscher, Gregory N.; Zhu, Dongming

    2013-01-01

    Interest in SiC fiber-reinforced SiC ceramic matrix composite (CMC) environmental barrier coating (EBC) systems for use in high temperature structural applications has prompted the need for characterization of material strength and creep performance under complex aerospace turbine engine environments. Stress-rupture tests have been performed on SiC/SiC composites systems, with varying fiber types and coating schemes to demonstrate material behavior under isothermal conditions. Further testing was conducted under exposure to thermal stress gradients to determine the effect on creep resistance and material durability. In order to understand the associated damage mechanisms, emphasis is placed on experimental techniques as well as implementation of non-destructive evaluation; including electrical resistivity monitoring. The influence of environmental and loading conditions on life-limiting material properties is shown.

  15. Experimental and Theoretical Investigations on the Nanoscale Kinetic Friction in Ambient Environmental Conditions.

    PubMed

    Gueye, Birahima; Zhang, Yan; Wang, Yujuan; Chen, Yunfei

    2015-07-01

    The liquid lubrication, thermolubricity and dynamic lubricity due to mechanical oscillations are investigated with an atomic force microscope in ambient environmental conditions with different relative humidity (RH) levels. Experimental results demonstrate that high humidity at low-temperature regime enhances the liquid lubricity while at high-temperature regime it hinders the effect of the thermolubricity due to the formation of liquid bridges. Friction response to the dynamic lubricity in both high- and low-temperature regimes keeps the same trends, namely the friction force decreases with increasing the amplitude of the applied vibration on the tip regardless of the RH levels. An interesting finding is that for the dynamic lubricity at high temperature, high-humidity condition leads to the friction forces higher than that at low-humidity condition while at low temperature the opposite trend is observed. An extended two-dimensional dynamic model accounting for the RH is proposed to interpret the frictional mechanism in ambient conditions. PMID:26103087

  16. Environmental conditions in favour of a hantavirus outbreak in 2015 in Germany?

    PubMed

    Reil, D; Imholt, C; Drewes, S; Ulrich, R G; Eccard, J A; Jacob, J

    2016-03-01

    Bank voles can harbour Puumala virus (PUUV) and vole populations usually peak in years after beech mast. A beech mast occurred in 2014 and a predictive model indicates high vole abundance in 2015. This pattern is similar to the years 2009/2011 when beech mast occurred, bank voles multiplied and human PUUV infections increased a year later. Given similar environmental conditions in 2014/2015, increased risk of human PUUV infections in 2015 is likely. Risk management measures are recommended. PMID:26177110

  17. Fitness consequences of environmental conditions at different life stages in a long-lived vertebrate

    PubMed Central

    Douhard, Mathieu; Plard, Floriane; Gaillard, Jean-Michel; Capron, Gilles; Delorme, Daniel; Klein, François; Duncan, Patrick; Loe, Leif Egil; Bonenfant, Christophe

    2014-01-01

    The predictive adaptive response (PAR) hypothesis proposes that animals adjust their physiology and developmental trajectory during early life in anticipation of their future environments. Accordingly, when environmental conditions in early life match environmental conditions during adulthood, individual fitness should be greater. Here, we test this hypothesis in a long-lived mammal, the roe deer, using data from two contrasting populations, intensively monitored for more than 35 years. In the highly productive site, the fitness of female roe deer increased with the quality of environment during adulthood and, contrary to predictions of PAR, individuals born in good conditions always outperformed those born under poor conditions. In the resource-limited site, the fitness of female roe deer born in poor years was better than those born in good conditions in poor years when the animals were adult, but not in good years. Although consistent with predictions of PAR, we showed that this pattern is likely to be a consequence of increased viability selection during the juvenile stage for animals born in poor years. While PARs are often advanced in evolutionary medicine, our findings suggest that detailed biological processes should be investigated before drawing conclusions about the existence of this phenomenon. PMID:24789898

  18. Heteroaggregation of titanium dioxide nanoparticles with model natural colloids under environmentally relevant conditions.

    PubMed

    Praetorius, Antonia; Labille, Jérôme; Scheringer, Martin; Thill, Antoine; Hungerbühler, Konrad; Bottero, Jean-Yves

    2014-09-16

    The heteroaggregation of engineered nanoparticles (ENPs) with natural colloids (NCs), which are ubiquitous in natural surface waters, is a crucial process affecting the environmental transport and fate of ENPs. Attachment efficiencies for heteroaggregation, ? hetero, are required as input parameters in environmental fate models to predict ENP concentrations and contribute to ENP risk assessment. Here, we present a novel method for determining ? hetero values by using a combination of laser diffraction measurements and aggregation modeling based on the Smoluchowski equation. Titanium dioxide nanoparticles (TiO2 NPs, 15 nm) were used to demonstrate this new approach together with larger silicon dioxide particles (SiO2, 0.5 ?m) representing NCs. Heteroaggregation experiments were performed at different environmentally relevant solution conditions. At pH 5 the TiO2 NPs and the SiO2 particles are of opposite charge, resulting in ? hetero values close to 1. At pH 8, where all particles are negatively charged, ? hetero was strongly affected by the solution conditions, with ? hetero ranging from <0.001 at low ionic strength to 1 at conditions with high NaCl or CaCl2 concentrations. The presence of humic acid stabilized the system against heteroaggregation. PMID:25127331

  19. Role of phenotypic plasticity and population differentiation in adaptation to novel environmental conditions.

    PubMed

    Volis, Sergei; Ormanbekova, Danara; Yermekbayev, Kanat

    2015-09-01

    Species can adapt to new environmental conditions either through individual phenotypic plasticity, intraspecific genetic differentiation in adaptive traits, or both. Wild emmer wheat, Triticum dicoccoides, an annual grass with major distribution in Eastern Mediterranean region, is predicted to experience in the near future, as a result of global climate change, conditions more arid than in any part of the current species distribution. To understand the role of the above two means of adaptation, and the effect of population range position, we analyzed reaction norms, extent of plasticity, and phenotypic selection across two experimental environments of high and low water availability in two core and two peripheral populations of this species. We studied 12 quantitative traits, but focused primarily on the onset of reproduction and maternal investment, which are traits that are closely related to fitness and presumably involved in local adaptation in the studied species. We hypothesized that the population showing superior performance under novel environmental conditions will either be genetically differentiated in quantitative traits or exhibit higher phenotypic plasticity than the less successful populations. We found the core population K to be the most plastic in all three trait categories (phenology, reproductive traits, and fitness) and most successful among populations studied, in both experimental environments; at the same time, the core K population was clearly genetically differentiated from the two edge populations. Our results suggest that (1) two means of successful adaptation to new environmental conditions, phenotypic plasticity and adaptive genetic differentiation, are not mutually exclusive ways of achieving high adaptive ability; and (2) colonists from some core populations can be more successful in establishing beyond the current species range than colonists from the range extreme periphery with conditions seemingly closest to those in the new environment. PMID:26380708

  20. Role of phenotypic plasticity and population differentiation in adaptation to novel environmental conditions

    PubMed Central

    Volis, Sergei; Ormanbekova, Danara; Yermekbayev, Kanat

    2015-01-01

    Species can adapt to new environmental conditions either through individual phenotypic plasticity, intraspecific genetic differentiation in adaptive traits, or both. Wild emmer wheat, Triticum dicoccoides, an annual grass with major distribution in Eastern Mediterranean region, is predicted to experience in the near future, as a result of global climate change, conditions more arid than in any part of the current species distribution. To understand the role of the above two means of adaptation, and the effect of population range position, we analyzed reaction norms, extent of plasticity, and phenotypic selection across two experimental environments of high and low water availability in two core and two peripheral populations of this species. We studied 12 quantitative traits, but focused primarily on the onset of reproduction and maternal investment, which are traits that are closely related to fitness and presumably involved in local adaptation in the studied species. We hypothesized that the population showing superior performance under novel environmental conditions will either be genetically differentiated in quantitative traits or exhibit higher phenotypic plasticity than the less successful populations. We found the core population K to be the most plastic in all three trait categories (phenology, reproductive traits, and fitness) and most successful among populations studied, in both experimental environments; at the same time, the core K population was clearly genetically differentiated from the two edge populations. Our results suggest that (1) two means of successful adaptation to new environmental conditions, phenotypic plasticity and adaptive genetic differentiation, are not mutually exclusive ways of achieving high adaptive ability; and (2) colonists from some core populations can be more successful in establishing beyond the current species range than colonists from the range extreme periphery with conditions seemingly closest to those in the new environment. PMID:26380708

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Thermal imaging of cucumber leaves affected by downy mildew and environmental conditions.

    PubMed

    Oerke, E-C; Steiner, U; Dehne, H-W; Lindenthal, M

    2006-01-01

    Pathogenesis of Pseudoperonospora cubensis causing downy mildew of cucumber resulted in changes in the metabolic processes within cucumber leaves including the transpiration rate. Due to the negative correlation between transpiration rate and leaf temperature, digital infrared thermography permitted a non-invasive monitoring and an indirect visualization of downy mildew development. Depending on the stage of pathogenesis and the topology of chloroses and necroses, infection resulted in a typical temperature pattern. Spatial heterogeneity of the leaf temperature could be quantified by the maximum temperature difference (MTD) within a leaf. The MTD increased during pathogenesis with the formation of necrotic tissue and was related to disease severity as described by linear and quadratic regression curves. Under controlled conditions, changes in temperature of infected leaves allowed the discrimination between healthy and infected areas in thermograms, even before visible symptoms of downy mildew appeared. Environmental conditions during thermographic measurement, in particular air temperature and humidity, as well as water content and age of the leaf influenced the temperature of its surface. Conditions enhancing the transpiration rate facilitated the detection of changes in leaf temperature of infected leaves at early stages of infection. As modified by environmental conditions, MTD alone is not suitable for the quantification of downy mildew severity in the field. PMID:16714311

  3. Distinctive Representation of Mispredicted and Unpredicted Prediction Errors in Human Electroencephalography.

    PubMed

    Hsu, Yi-Fang; Le Bars, Solene; Hämäläinen, Jarmo A; Waszak, Florian

    2015-10-28

    The predictive coding model of perception proposes that neuronal responses are modulated by the amount of sensory input that the internal prediction cannot account for (i.e., prediction error). However, there is little consensus on what constitutes nonpredicted stimuli. Conceptually, whereas mispredicted stimuli may induce both prediction error generated by prediction that is not perceived and prediction error generated by sensory input that is not anticipated, unpredicted stimuli involves no top-down, only bottom-up, propagation of information in the system. Here, we examined the possibility that the processing of mispredicted and unpredicted stimuli are dissociable at the neurophysiological level using human electroencephalography. We presented participants with sets of five tones in which the frequency of the fifth tones was predicted, mispredicted, or unpredicted. Participants were required to press a key when they detected a softer fifth tone to maintain their attention. We found that mispredicted and unpredicted stimuli are associated with different amount of cortical activity, probably reflecting differences in prediction error. Moreover, relative to predicted stimuli, the mispredicted prediction error manifested as neuronal enhancement and the unpredicted prediction error manifested as neuronal attenuation on the N1 event-related potential component. These results highlight the importance of differentiating between the two nonpredicted stimuli in theoretical work on predictive coding. PMID:26511253

  4. The terrestrial snail, Helix pomatia, adapts to environmental conditions by the modulation of central arousal.

    PubMed

    Hernádi, L; Hiripi, L; Gyori, J; Szabó, Henriette; Vehovszky, Agnes

    2008-01-01

    The osmotic stimulation which is able to change the behavioral state of the animal are most effective during rainy weather while they are less effective during dry weather conditions. In isolated CNS preparations from aestivated animals the highest firing activity and serotonin sensitivity of the serotonergic (RPas) heart modulator neurons are recorded during rainy weather and the lowest parameters are observed in dry conditions. In aestivated animals the serotonin (5HT) content in both the CNS and the foot is higher than the dopamine (DA) content during rainy weather, while in dry weather the DA level is higher than the 5HT. The inactivation-reactivation process is accompanied by decreasing both the DA and 5HT levels in the CNS and increasing them in the peripheral organs. Our results suggest that aestivated animals adapt to (favorable and unfavorable) environmental conditions by modulating their central arousal state through changing the levels and distribution of monoamines (5HT, DA) in their body. PMID:18652371

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

    SciTech Connect

    Daugherty, W; Stephen Harris, S

    2007-06-13

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

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

    PubMed Central

    2013-01-01

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

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

    PubMed

    Mader, T L

    2014-12-01

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

  8. Environmental Conditions in Low-Income Urban Housing: Clustering and Associations With Self-Reported Health

    PubMed Central

    Spengler, John D.; Harley, Amy E.; Stoddard, Anne; Yang, May; Alvarez-Reeves, Marty; Sorensen, Glorian

    2014-01-01

    Objectives. We explored prevalence and clustering of key environmental conditions in low-income housing and associations with self-reported health. Methods. The Health in Common Study, conducted between 2005 and 2009, recruited participants (n = 828) from 20 low-income housing developments in the Boston area. We interviewed 1 participant per household and conducted a brief inspection of the unit (apartment). We created binary indexes and a summed index for household exposures: mold, combustion by-products, secondhand smoke, chemicals, pests, and inadequate ventilation. We used multivariable logistic regression to examine the associations between each index and household characteristics and between each index and self-reported health. Results. Environmental problems were common; more than half of homes had 3 or more exposure-related problems (median summed index = 3). After adjustment for household-level demographics, we found clustering of problems in site (P < .01) for pests, combustion byproducts, mold, and ventilation. Higher summed index values were associated with higher adjusted odds of reporting fair–poor health (odds ratio = 2.7 for highest category; P < .008 for trend). Conclusions. We found evidence that indoor environmental conditions in multifamily housing cluster by site and that cumulative exposures may be associated with poor health. PMID:24028244

  9. Identifying the environmental conditions favouring West Nile Virus outbreaks in Europe.

    PubMed

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

    2015-01-01

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

  10. Identifying the Environmental Conditions Favouring West Nile Virus Outbreaks in Europe

    PubMed Central

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

    2015-01-01

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

  11. Photoacclimation supports environmental tolerance of a sponge to turbid low-light conditions

    NASA Astrophysics Data System (ADS)

    Biggerstaff, A.; Smith, D. J.; Jompa, J.; Bell, J. J.

    2015-12-01

    Changes to coral reefs are occurring worldwide, often resulting in declining environmental quality which can be in the form of higher sedimentation rates and increased turbidity. While environmental acclimation to turbid and low-light conditions has been extensively studied in corals, far less is known about other phototrophic reef invertebrates. The photosynthetic cyanobacteria containing sponge Lamellodysidea herbacea is one of the most abundant sponges in the Wakatobi Marine National Park (WMNP, Indonesia), and its abundance is greatest at highly disturbed, turbid sites. This study investigated photoacclimation of L. herbacea symbionts to turbid reef sites using in situ PAM fluorometry combined with shading and transplant experiments at environmental extremes of light availability for this species. We found in situ photoacclimation of L. herbacea to both shallow, clear, high-light environments and deep, turbid, low-light environments. Shading experiments provide some evidence that L. herbacea are dependent on nutrition from their photosymbionts as significant tissue loss was seen in shaded sponges. Symbionts within surviving shaded tissue showed evidence of photoacclimation. Lamellodysidea herbacea transplanted from high- to low-light conditions appeared to have photoacclimated within 5 d with no significant effect of the lowered light level on survival. This ability of L. herbacea to photoacclimate to rapid and extreme changes in light availability may be one of the factors contributing to their survival on more turbid reef sites in the WMNP. Our study highlights the ability of some sponge species to acclimate to changes in light levels as a result of increased turbidity.

  12. Variation in the Abundance of Neotropical Bees in an Unpredictable Seasonal Environment.

    PubMed

    Knoll, F R N

    2016-04-01

    This study provides information on the number of orchid bees based on a long-term monitoring study in an antropized savanna region in Southeastern Brazil. Sampling was carried out using chemical lures, and 77 samples were monthly collected to assess the number of individuals as well as the annual and seasonal species fluctuation. The number of species varied significantly among years but not among months, and there was a positive correlation between the number of species and the number of individuals in each sample. Monthly number counts revealed a seasonal pattern for Eulaema nigrita Lepeletier and Exaerete smaragdina Perty, which were more numerous during humid months but peaked in December, January, and February. Different species of Euglossa presented a significant variation in number among years, but not among months, with no pattern along the years. The community and the populations studied were less stable when compared to those of well-preserved habitats of equatorial forests. The El Niño phenomenon of 1997/98 did not result in negative effects in the populations studied; on the contrary, there was a peak in the number of E. nigrita. The amplitude in the yearly variation of the male orchid bee population reflects the evolutionary history of species living in unpredictable seasonal weather that led to the development of particular adaptive traits designed to deal with environmental uncertainties. This study suggests that the plasticity of the life cycle may explain population stability and provide greater resilience to severe climate change events in the future. PMID:26597968

  13. Experimental evidence of population differences in reproductive investment conditional on environmental stochasticity.

    PubMed

    Gauthey, Zoé; Panserat, Stéphane; Elosegi, Arturo; Herman, Alexandre; Tentelier, Cédric; Labonne, Jacques

    2016-01-15

    Environmental stochasticity is expected to shape life histories of species, wherein organisms subjected to strong environmental variation should display adaptive response by being able to tune their reproductive investment. For riverine ecosystems, climate models forecast an increase in the frequency and intensity of extreme events such as floods and droughts. The speed and the mechanisms by which organisms may adapt their reproductive investment are therefore of primary importance to understand how species will cope with such radical environmental changes. In the present study, we sampled spawners from two different populations of wild brown trout, originating from two environments with contrasting levels of flow stochasticity. We placed them in sympatry within an experimental channel during reproductive season. In one modality, water flow was maintained constant, whereas in another modality, water flow was highly variable. Reproductive investment of all individuals was monitored using weight and energetic plasma metabolite variation throughout the reproductive season. Only the populations originating from the most variable environment showed a plastic response to experimental manipulation of water flow, the females being able to reduce their weight variation (from 19.2% to 13.1%) and metabolites variations (from 84.2% to 18.6% for triglycerides for instance) under variable flow conditions. These results imply that mechanisms to cope with environmental stochasticity can differ between populations of the same species, where some populations can be plastic whereas other cannot. PMID:26406108

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

    PubMed Central

    Koivula, Matti J.

    2011-01-01

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

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

    PubMed

    Koivula, Matti J

    2011-01-01

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

  16. Environmental Conditions Influence the Plant Functional Diversity Effect on Potential Denitrification

    PubMed Central

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

    2011-01-01

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

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

    PubMed

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

    2014-12-01

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

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

    PubMed Central

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

    2011-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

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

    PubMed

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

    2011-11-22

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

  1. Response of mosquitofish (Gambusia affinis) populations to seasonally unpredictable perturbations

    SciTech Connect

    Horn, M.J.; Stewart, A.J.

    1990-07-01

    Many questions remain unresolved about the linkages between life history attributes of fishes and the tactics that these organisms employ in response to environmental uncertainty. Such questions include (1). If a perturbation affects the entire ecosystem, what are the consequences for a given population of fish (2) What tactics can a fish employ to increase its chances of leaving offspring (3) Do fish respond differently to such perturbations depending on the season (4) How do these changes relate to the overall resilience of the population The research reported here was designed to address such questions. Mosquito fish (Gambusia affinis) populations in thirteen experimental ponds at Oak Ridge National Laboratory were sampled ten times between June 1988, and July 1989 in response to a series of chemical disturbances. During each sampling period the population size and total biomass of Gambusia in each pond was estimated using photographs and a length weight regression. Size-frequency histograms were used to examine seasonal and dose-related changes in population structure. Lipid content and reproductive allotment were measured for a series of fish from each pond on all dates to explore the energy allocation patterns at the individual. 106 refs., 38 figs., 16 tabs.

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

    PubMed

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

    2015-04-15

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

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  4. Evaluating GIS for establishing and monitoring environmental conditions of oil fields

    SciTech Connect

    Pfeil, R.W.; Ellis, J.W.

    1995-04-01

    Good management of an oil field and compliance with ever-increasing environmental regulations is enhanced by technologies that improve a company`s understanding of field/production facilities and environmental conditions that have occurred to both through time. In Nigeria, Kazakhstan, Indonesia, and offshore Cabinda, remote sensing, computer-aided drafting (CAD) and Global Positioning System (GPF) technologies have effectively been used by Chevron to provide accurate maps of facilities and to better understand environmental conditions. Together these proven technologies have provided a solid and cost-effective base for planning field operation, verifying well and seismic locations, and locating sampling sites. The end product of these technologies is often locations, and locating sampling sites. The end product of these technologies is often cartographic-quality hardcopy images and maps for use in the office and field. Chevron has been evaluating the capability of Geographical Information System (GIS) technology to integrate images, maps, and tabular data into a useful database that can help managers and workers better evaluate conditions in an oil field, plan new facilities, and monitor/predict trends (for example, of air emissions, groundwater, soil chemistry, subsidence, etc.). Remote sensing, CAD (if formatted properly), and GPS data can be integrated to establish the spatial or cartographic base of the GIS. A major obstacle to establishing a sophisticated GIS for an overseas operation is the initial cost of data collection and conversion from legacy data base management systems and hardcopy to appropriate digital format. However, Chevron routinely uses GIS for oil spill modeling and is now using GIS in the field for integrating GPS data with field observations and programs.

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

    PubMed Central

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

    2014-01-01

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

  6. Note: Electrical resolution during conductive atomic force microscopy measurements under different environmental conditions and contact forces

    SciTech Connect

    Lanza, M.; Porti, M.; Nafria, M.; Aymerich, X.; Whittaker, E.; Hamilton, B.

    2010-10-15

    Conductive atomic force microscopy experiments on gate dielectrics in air, nitrogen, and UHV have been compared to evaluate the impact of the environment on topography and electrical measurements. In current images, an increase of the lateral resolution and a reduction of the conductivity were observed in N{sub 2} and, especially, in UHV (where current depends also on the contact force). Both effects were related to the reduction/elimination of the water layer between the tip and the sample in N{sub 2}/UHV. Therefore, since current measurements are very sensitive to environmental conditions, these factors must be taken into consideration when comparisons between several experiments are performed.

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

    PubMed

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

    2004-09-20

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

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

    PubMed

    Rynkiewicz, Evelyn C; Clay, Keith

    2014-01-01

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

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

    PubMed Central

    Rothstein, Steven J.

    2013-01-01

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

  11. The antidepressant effect of an antiulcer pentadecapeptide BPC 157 in Porsolt's test and chronic unpredictable stress in rats. A comparison with antidepressants.

    PubMed

    Sikiric, P; Separovic, J; Buljat, G; Anic, T; Stancic-Rokotov, D; Mikus, D; Marovic, A; Prkacin, I; Duplancic, B; Zoricic, I; Aralica, G; Lovric-Bencic, M; Ziger, T; Perovic, D; Rotkvic, I; Mise, S; Hanzevacki, M; Hahn, V; Seiwerth, S; Turkovic, B; Grabarevic, Z; Petek, M; Rucman, R

    2000-01-01

    Various antidepressants have antiulcer activity. Likewise, the models currently used in ulcers and depression disorders research have a considerable degree of similarity. Therefore, the possibility that depression disorders could be effectively influenced by a primary antiulcer agent with a cyto/organoprotective activity, such as the novel stomach pentadecapeptide BPC 157, was investigated in two rat depression assays. First, a forced swimming test (a Porsolt's procedure) was used. As a more severe procedure, chronic unpredictable stress (after 5 d of unpredictable stress protocol, once daily drug application during stress procedure, open field-immobility test assessment at fourth or sixth day of medication) was used. In a forced swimming test, a reduction of the immobility time in BPC 157 (10 microg, 10 ng x kg(-1) i.p.) treated rats corresponds to the activity of the 15 mg or 40 mg (i.p.) of conventional antidepressants, imipramine or nialamide, respectively, given according to the original Porsolt's protocol. In chronic unpredictable stress procedure, particular aggravation of experimental conditions markedly affected the conventional antidepressant activity, whereas BPC 157 effectiveness was continuously present. The effect of daily imipramine (30 mg) medication could be seen only after a more prolonged period, but not after a shorter period (i.e., 4-d protocol). In these conditions, no delay in the effectiveness was noted in BPC 157 medication and a reduction of the immobility of chronically stressed rats was noted after both 4 and 6 d of BPC 157 (10 microg, 10 ng) medication. PMID:10791689

  12. Detection of structural damage using novelty detection algorithm under variational environmental and operational conditions

    NASA Astrophysics Data System (ADS)

    El Mountassir, M.; Yaacoubi, S.; Dahmene, F.

    2015-07-01

    Novelty detection is a widely used algorithm in different fields of study due to its capabilities to recognize any kind of abnormalities in a specific process in order to ensure better working in normal conditions. In the context of Structural Health Monitoring (SHM), this method is utilized as damage detection technique because the presence of defects can be considered as abnormal to the structure. Nevertheless, the performance of such a method could be jeopardized if the structure is operating in harsh environmental and operational conditions (EOCs). In this paper, novelty detection statistical technique is used to investigate the detection of damages under various EOCs. Experiments were conducted with different scenarios: damage sizes and shapes. EOCs effects were simulated by adding stochastic noise to the collected experimental data. Different levels of noise were studied to determine the accuracy and the performance of the proposed method.

  13. Nonlinear Dielectric Properties of Yeast Cells Cultured in Different Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Kawanishi, Gomon; Fukuda, Naoki; Muraji, Masafumi

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

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

    PubMed

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

    2005-09-01

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

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

    PubMed

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

    2015-01-01

    The genome of the Antarctic bacterium Pseudomonas extremaustralis was analyzed searching for genes involved in environmental adaptability focusing on anaerobic metabolism, osmoregulation, cold adaptation, exopolysaccharide production and degradation of complex compounds. Experimental evidences demonstrated the functionality of several of these pathways, including arginine and pyruvate fermentation, alginate production and growth under cold conditions. Phylogenetic analysis along with genomic island prediction allowed the detection of genes with probable foreign origin such as those coding for acetate kinase, osmotic resistance and colanic acid biosynthesis. These findings suggest that in P. extremaustralis the horizontal transfer events and/or gene redundancy could play a key role in the survival under unfavorable conditions. Comparative genome analysis of these traits in other representative Pseudomonas species highlighted several similarities and differences with this extremophile bacterium. PMID:25316211

  16. Exploration of Experimental Data On Atrazine Degradation In Relation To Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Putters, B.

    The objective of this project is to find the soil factors which dominate the degradation behaviour of atrazine (pesticide). From published experiments on atrazine degradation in the subsurface, the available data concerning soil characteristics, experimental conditions, and the measured degra- dation rates were put into a database. From literature, environmental conditions could be related to degradation rates. These relationships were tested by exploration of the dataset by statistical techniques. In general, the degradation is mainly determined by the availability of the substrate (atrazine) and the biological activity. More specific re- lationships could be derived from the dataset and will be presented at the conference. The relationships can also be used for degradation rate estimates for modelling pur- poses.

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

    PubMed

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

    2015-01-01

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

  18. [Role of micro-organisms in adapting plants to environmental stress conditions].

    PubMed

    Hirt, Heribert

    2012-01-01

    Due to their sessile nature, plants have always been confronted to various abiotic and biotic stresses in their immediate environment. As a consequence, the survival of plants depended on their ability to adjust rapidly their physiology, development and growth to escape or mitigate the impacts of stress. All plants are known to perceive and respond to stress signals such as drought, heat, salinity, attacks by herbivores and pathogens. Some biochemical processes are common to all plant stress responses including the production of certain stress proteins and metabolites, as well as the modification of the reactive oxygen species (ROS) metabolism. Although there has been extensive research in the plant stress response field, it is not yet known which factors are responsible for conferring to some plant species the capacity to colonize extreme habitats. Although considerable progress has been made in our understanding of plant stress physiology, the contribution of the plant-associated microbial community in the soil, commonly called the rhizosphere, has only recently received enhanced attention. Recent studies showed that some plant species in natural habitats require microbial associations for stress tolerance and survival. Since plants have colonized land, they have evolved mechanisms to respond to changing environmental conditions and settle in extreme habitats. Although many plants lack the adaptive capability to adapt to stress conditions, the ability of a variety of plants to adapt to stress conditions appears to depend on the association with microbes, raising a number of questions: can all plants improve stress tolerance when associated with their appropriate microbial partners? Did we miss identifying the right partners for a given plant species or variety? What distinguishes the microbes and plants that are adapted to extreme environmental conditions from those living in temperate zones? Answers to these questions are likely to revolutionize plant biology and could lead to new methods for a sustainable agriculture. PMID:23419255

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

    PubMed

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

    2015-04-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1998-01-01

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

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

    PubMed

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

    2008-05-01

    A series of batch tests were performed and the impacts of environmental conditions and phase change on the sorption of volatile organic compounds (VOCs) were investigated. Benzene, trichloroethylene, tetrachloroethylene, and ethylbenzene were selected as target VOCs. Sorption of VOCs onto tire powder was well demonstrated by a linear-partitioning model. Water-tire partition coefficients of VOCs (not tested in this study) could be estimated using a logarithmic relationship between observed water-tire partition coefficients and octanol-water partition coefficients of the VOCs tested. The target VOCs did not seem to compete with other VOCs significantly when sorbed onto the tire powder for the range of concentrations tested. The influence of environmental conditions, such as pH and ionic strength also did not seem to be significant. Water-tire partition coefficients of benzene, trichloroethylene, tetrachloroethylene, and ethylbenzene decreased as the sorbent dosage increased. However, they showed stable values when the sorbent dosage was greater than 10 g/L. Air-tire partition coefficient could be extrapolated from Henry's law constants and water-tire partition coefficient of VOCs. PMID:17889437

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

    PubMed

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

    2014-07-01

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

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

    USGS Publications Warehouse

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

    2012-01-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    USGS Publications Warehouse

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

    2014-01-01

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

  6. Using magnetically responsive tea waste to remove lead in waters under environmentally relevant conditions.

    PubMed

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

    2013-01-01

    We report the use of a simple yet highly effective magnetite-waste tea composite to remove lead(II) (Pb(2+)) ions from water. Magnetite-waste tea composites were dispersed in four different types of water-deionized (DI), artificial rainwater, artificial groundwater and artificial freshwater-that mimic actual environmental conditions. The water samples had varying initial concentrations (0.16-5.55 ppm) of Pb(2+) ions and were mixed with the magnetite-waste tea composite for at least 24 hours to allow adsorption of the Pb(2+) ions to reach equilibrium. The magnetite-waste tea composites were stable in all the water samples for at least 3 months and could be easily removed from the aqueous media via the use of permanent magnets. We detected no significant leaching of iron (Fe) ions into the water from the magnetite-waste tea composites. The percentage of Pb adsorbed onto the magnetite-waste tea composite ranged from ?70% to 100%; the composites were as effective as activated carbon (AC) in removing the Pb(2+) ions from water, depending on the initial Pb concentration. Our prepared magnetite-waste tea composites show promise as a green, inexpensive and highly effective sorbent for removal of Pb in water under environmentally realistic conditions. PMID:23818955

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  10. A review on the effects of environmental conditions on growth and toxin production of Ostreopsis ovata.

    PubMed

    Pistocchi, R; Pezzolesi, L; Guerrini, F; Vanucci, S; Dell'aversano, C; Fattorusso, E

    2011-03-01

    Since the end of the 1990s the occurrence of blooms of the benthic dinoflagellates Ostreopsis spp. is spreading in many tropical and temperate regions worldwide, sometimes causing benthonic biocenosis suffering and occasional human distress. Ostreopsis ovata has been found to produce palytoxin-like compounds, a class of highly potent toxins. As general, the highest abundances of Ostreopsis spp. are recorded during warmer periods characterized by high temperature, salinity, and water column stability. Moreover, as these cells are easily resuspended in the water column, the role of hydrodynamism in the blooms development and decline has been highlighted. The environmental conditions appear, therefore, to be one of the main factors determining the proliferation of these species as testified by several field surveys. Laboratory studies on the effect of environmental parameters on growth and toxicity of O. ovata are rather scarce. With regard to the effects of temperature, culture results indicate that different strains blooming along Italian coasts displayed different optima, in accordance to blooming periods, and that higher toxin levels correlated with best growth conditions. Additionally, in relation to an Adriatic strain, cell growth positively correlated with the increase in salinity, while toxicity was lowest at the highest salinity value (i.e. 40). For the same strain, both nitrogen and phosphorus limitation determined a decrease in cell toxicity showing different behaviour with respect to many other toxic dinoflagellates. PMID:20920514

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

    PubMed

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

    2014-07-01

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

  12. Role of genetic factors and environmental conditions in recombinant protein production for molecular farming.

    PubMed

    Jamal, Arshad; Ko, Kinarm; Kim, Hyun-Soon; Choo, Young-Kug; Joung, Hyouk; Ko, Kisung

    2009-01-01

    Plants are generally considered to represent a promising heterologous expression system for the production of valuable recombinant proteins. Minimal upstream plant production cost is a salient feature driving the development of plant expression systems used for the synthesis of recombinant proteins. For such a plant expression system to be fully effective, it is first essential to improve plant productivity by plant biomass after inserting genes of interest into a suitable plant. Plant productivity is related closely to its growth and development, both of which are affected directly by environmental factors. These environmental factors that affect the cultivation conditions mainly include temperature, light, salinity, drought, nutrition, insects and pests. In addition, genetic factors that affect gene expression at the transcriptional, translational, and post-translational levels are considered to be important factors related to gene expression in plants. Thus, these factors influence both the quality and quantity of recombinant protein produced in transgenic plants. Among the genetic factors, the post-translational process is of particular interest as it influences subcellular localization, protein glycosylation, assembly and folding of therapeutic proteins, consequently affecting both protein quantity and biological quality. In this review, we discuss the effects of cultivation condition and genetic factors on recombinant protein production in transgenic plants. PMID:19698776

  13. The transcriptomic responses of the eastern oyster, Crassostrea virginica, to environmental conditions.

    PubMed

    Chapman, Robert W; Mancia, Annalaura; Beal, Marion; Veloso, Artur; Rathburn, Charles; Blair, Anne; Holland, A F; Warr, G W; Didinato, Guy; Sokolova, Inna M; Wirth, Edward F; Duffy, Edward; Sanger, Denise

    2011-04-01

    Understanding the mechanisms by which organisms adapt to environmental conditions is a fundamental question for ecology and evolution. In this study, we evaluate changes in gene expression of a marine mollusc, the eastern oyster Crassostrea virginica, associated with the physico-chemical conditions and the levels of metals and other contaminants in their environment. The results indicate that transcript signatures can effectively disentangle the complex interactive gene expression responses to the environment and are also capable of disentangling the complex dynamic effects of environmental factors on gene expression. In this context, the mapping of environment to gene and gene to environment is reciprocal and mutually reinforcing. In general, the response of transcripts to the environment is driven by major factors known to affect oyster physiology such as temperature, pH, salinity, and dissolved oxygen, with pollutant levels playing a relatively small role, at least within the range of concentrations found in the studied oyster habitats. Further, the two environmental factors that dominate these effects (temperature and pH) interact in a dynamic and nonlinear fashion to impact gene expression. Transcriptomic data obtained in our study provide insights into the mechanisms of physiological responses to temperature and pH in oysters that are consistent with the known effects of these factors on physiological functions of ectotherms and indicate important linkages between transcriptomics and physiological outcomes. Should these linkages hold in further studies and in other organisms, they may provide a novel integrated approach for assessing the impacts of climate change, ocean acidification and anthropogenic contaminants on aquatic organisms via relatively inexpensive microarray platforms. PMID:21426432

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

    PubMed

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

    2014-04-01

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

  15. National Education Goals and Standards: The Unpredictable Evolution of National Policy for All Students.

    ERIC Educational Resources Information Center

    Dungan, Andy T.; Brownbridge, Robert D.

    The National Education Goals, Goals 2000, were signed into law by President Clinton in 1994. From 1989 to 1994 the goals existed in a symbolic context with minimal funding to support them. An unpredictable series of events sustained the National Education Goals through a period of potential obscurity to enactment. The goals appear to be unique in…

  16. Living organisms influence on environmental conditions: pH modulation by amphibian embryos versus aluminum toxicity.

    PubMed

    Herkovits, Jorge; Castañaga, Luis Alberto; D'Eramo, José Luis; Jourani, Victoria Platonova

    2015-11-01

    The LC10, 50 and 90/24h of aluminum for Rhinella arenarum embryos at complete operculum stage were 0.55, 0.75 and 1mgAl(3+)/L respectively. Those values did not change significantly by expanding the exposure period till 168h. The aluminum toxicity was evaluated in different pH conditions by means of a citrate buffer resulting for instance, 1mgAl(3+)/L at pH 4, 4.1, 5 and 6 in 100%, 70%, 35% and 0% of lethality respectively. As an outstanding feature, the embryos changed the pH of the maintaining media both in the case of Al(3+) or citrate buffer treatments toward neutral. 10 embryos in 40mL of AMPHITOX solution were able to increase the pH from 4.2 to 7.05, a fact related with a metabolic shift resulting in an increase in nitrogen loss as ammonia. Our study point out the natural selection of the most resistant amphibian embryos both for pH or aluminum as well as the capacity of living organisms (as a population) to alter their chemical environment toward optimal conditions for their survival. As these facts occur at early life stages, it expand the concept that living organisms at ontogenic stages are biomarker of environmental signatures of the evolutionary process (Herkovits, 2006) to a global Onto-Evo concept which imply also the feedback mechanisms from living organisms to shape environmental conditions in a way that benefits them. PMID:26126231

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

    PubMed

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

    2010-06-15

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

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

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

  20. Multiscale effects of management, environmental conditions, and land use on nitrate leaching in dairy farms.

    PubMed

    Oenema, Jouke; Burgers, Saskia; Verloop, Koos; Hooijboer, Arno; Boumans, Leo; ten Berge, Hein

    2010-01-01

    Nitrate leaching in intensive grassland- and silage maize-based dairy farming systems on sandy soil is a main environmental concern. Here, statistical relationships are presented between management practices and environmental conditions and nitrate concentration in shallow groundwater (0.8 m depth) at farm, field, and point scales in The Netherlands, based on data collected in a participatory approach over a 7-yr period at one experimental and eight pilot commercial dairy farms on sandy soil. Farm milk production ranged from 10 to 24 Mg ha(-1). Soil and hydrological characteristics were derived from surveys and weather conditions from meteorological stations. Statistical analyses were performed with multiple regression models. Mean nitrate concentration at farm scale decreased from 79 mg L(-1) in 1999 to 63 in 2006, with average nitrate concentration in groundwater decreasing under grassland but increasing under maize land over the monitoring period. The effects of management practices on nitrate concentration varied with spatial scale. At farm scale, nitrogen surplus, grazing intensity, and the relative areas of grassland and maize land significantly contributed to explaining the variance in nitrate concentration in groundwater. Mean nitrate concentration was negatively correlated to the concentration of dissolved organic carbon in the shallow groundwater. At field scale, management practices and soil, hydrological, and climatic conditions significantly contributed to explaining the variance in nitrate concentration in groundwater under grassland and maize land. We conclude that, on these intensive dairy farms, additional measures are needed to comply with the European Union water quality standard in groundwater of 50 mg nitrate L(-1). The most promising measures are omitting fertilization of catch crops and reducing fertilization levels of first-year maize in the rotation. PMID:21284299

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

    NASA Astrophysics Data System (ADS)

    Ruprecht, Eszter; Fenesi, Annamária; Nijs, Ivan

    2013-02-01

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

  2. The ecophysiology of sulfur isotope fractionation by sulfate reducing bacteria in response to variable environmental conditions

    NASA Astrophysics Data System (ADS)

    Leavitt, W.; Bradley, A. S.; Johnston, D. T.; Pereira, I. A. C.; Venceslau, S.; Wallace, C.

    2014-12-01

    Microbial sulfate reducers (MSR) drive the Earth's biogeochemical sulfur cycle. At the heart of this energy metabolism is a cascade of redox transformations coupling organic carbon and/or hydrogen oxidation to the dissimilatory reduction of sulfate to sulfide. The sulfide produced is depleted in the heavier isotopes of sulfur relative to sulfate. The magnitude of discrimination (fractionation) depends on: i) the cell-specific sulfate reduction rate (csSRR, Kaplan & Rittenberg (1964) Can. J. Microbio.; Chambers et al. (1975) Can. J. Microbio; Sim et al. (2011) GCA; Leavitt et al. (2013) PNAS), ii) the ambient sulfate concentration (Harrison & Thode (1958) Research; Habicht et al. (2002) Science; Bradley et al. in review), iii) both sulfate and electron donor availability, or iv) an intrinsic physiological limitation (e.g. cellular division rate). When neither sulfate nor electron donor limits csSRR a more complex function relates the magnitude of isotope fractionation to cell physiology and environmental conditions. In recent and on-going work we have examined the importance of enzyme-specific fractionation factors, as well as the influence of electron donor or electron acceptor availability under carefully controlled culture conditions (e.g. Leavitt et al. (2013) PNAS). In light of recent advances in MSR genetics and biochemistry we utilize well-characterized mutant strains, along with a continuous-culture methodology (Leavitt et al. (2013) PNAS) to further probe the fractionation capacity of this metabolism under controlled physiological conditions. We present our latest findings on the magnitude of S and D/H isotope fractionation in both wild type and mutant strains. We will discuss these in light of recent theoretical advances (Wing & Halevy (2014) PNAS), examining the mode and relevance of MSR isotope fractionation in the laboratory to modern and ancient environmental settings, particularly anoxic marine sediments.

  3. Unpredictable Chronic Stress-Induced Reproductive Suppression Associated with the Decrease of Kisspeptin Immunoreactivity in Male Mice

    PubMed Central

    HIRANO, Tetsushi; KOBAYASHI, Yoshihiro; OMOTEHARA, Takuya; TATSUMI, Atsutoshi; HASHIMOTO, Rie; UMEMURA, Yuria; NAGAHARA, Daichi; MANTANI, Youhei; YOKOYAMA, Toshifumi; KITAGAWA, Hiroshi; HOSHI, Nobuhiko

    2014-01-01

    ABSTRACT Environmental stress affects various parts of mammals typically through the circulation of stress hormones. It has been identified as one of the possible reasons for male reproductive difficulties, but the complex mechanisms responsible for stress-induced reproductive suppression are poorly understood. Here, we examined the relationship between chronic environmental stress and hypothalamic kisspeptin, a recently discovered upstream regulator of the reproductive endocrine feedback system. We studied male mice under an unpredictable chronic stress procedure to replicate the situation of animals under chronic stress. Histological and immunohistochemical analyses were performed focusing on kisspeptin neurons in the arcuate hypothalamic nucleus (ARC) and DNA fragmented cells in seminiferous tubules. Although the ARC was not morphologically altered in either the stressed or non-stressed group, granular kisspeptin immunoreactivities decreased slightly in the stress group. In the testes of the stress group, several signs of testicular degeneration were observed, including increased numbers of ssDNA-positive cells per seminiferous tubule, thinning, vacuoled seminiferous epithelia and multinucleated giant cells. The decreases in kisspeptin in the stress group might be due to other hypothalamic peptides, such as corticotropin-releasing hormone and leptin, whose receptors are known to coexpress in the ARC. In addition, environmental stress directly and indirectly affects testicular function through stress hormones and gonadotropins. In summary, our findings enhance the understanding of stress-induced reproductive suppression possibly mediated by kisspeptin in the ARC. PMID:24871549

  4. Ethanol and cocaine: environmental place conditioning, stereotypy and synergism in planarians

    PubMed Central

    Tallarida, Christopher S.; Bires, Kristopher; Avershal, Jacob; Tallarida, Ronald J.; Seo, Stephanie; Rawls, Scott M.

    2015-01-01

    More than 90% of individuals who use cocaine also report concurrent ethanol use, but only a few studies, all conducted with vertebrates, have investigated pharmacodynamic interactions between ethanol and cocaine. Planaria, a type of flatworm often considered to have the simplest ‘brain’, is an invertebrate species especially amenable to the quantification of drug-induced behavioral responses and identification of conserved responses. Here, we investigated stereotypical and environmental place conditioning (EPC) effects of ethanol administered alone and in combination with cocaine. Planarians displayed concentration-related increases in C-shape movements following exposure to ethanol (0.01 – 1%) (maximal effect: 9.9 ± 1.1 C-shapes/5 min at 0.5%) or cocaine (0.1 – 5 mM) (maximal effect: 42.8 ± 4.1 C-shapes/5 min at 5 mM). For combined administration, cocaine (0.1 – 5 mM) were tested with submaximal ethanol concentrations (0.01, 0,1%), the observed effect for the combination was enhanced compared to its predicted effect, indicating synergism for the interaction. The synergy with ethanol was specific for cocaine, as related experiments revealed that combinations of ethanol and nicotine did not result in synergy. For EPC experiments, ethanol (0.0001 – 1%) concentration-dependently increased EPC, with significant environmental shifts detected at 0.01 and 1%. Cocaine (0.001 – 1 ?M) produced an inverted U-shaped concentration-effect curve, with a significant environmental shift observed at 0.01 ?M. For combined exposure, variable cocaine concentrations (0.001 – 1 ?M) were administered with a statistically ineffective concentration of ethanol (0.0001%). For each concentration of cocaine, the environmental shift was enhanced by ethanol, with significance detected at 1 ?M. Cocaethylene, a metabolite of cocaine and ethanol, also produced C-shapes and EPC. Lidocaine (0.001 – 10 ?M), an anesthetic and analog of cocaine, did not produce EPC or C-shape movements. Evidence from planarians that ethanol produces place-conditioning effects, motor dysfunction, and interacts synergistically with cocaine suggests that aspects of ethanol neuropharmacology are conserved across species. PMID:25212751

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

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  6. Environmental trends in extinction during the Paleozoic

    NASA Technical Reports Server (NTRS)

    Sepkoski, J. John, Jr.

    1987-01-01

    Extinction intensities calculated from 505 Paleozoic marine assemblages divided among six environmental zones and 40 stratigraphic intervals indicate that whole communities exhibit increasing extinction offshore but that genera within individual taxonomic classes tend to have their highest extinction onshore. The offshore trend at the community level results from a concentration of genera in classes with low characteristic extinction rates in nearshore environments. This finding is consistent with the ecologic expectation that organisms inhabiting unpredictably fluctuating environments should suffer more extinction than counterparts living under more predictably equitable conditions.

  7. Stability of ranitidine tablets subjected to stress and environmental conditions, by HPLC.

    PubMed

    Volonté, M G; Yuln, G; Mandrile, A; Longo, R; Cingolani, A

    2001-01-01

    High Performance Liquid Chromatographic (HPLC) method was applied in this study to comparatively evaluate the stability of tablets in their original package which 150 mg of Ranitidine from six different pharmaceutical laboratories in the market, according to ICH conditions for accelerated testing: 40 degrees C, 75% RH with and without light for six months. The stability at environmental conditions was evaluated for a twelve-month period, with and without light, with the same purpose. Ranitidine is widely used to treat peptic ulcer diseases. Ranitidine is susceptible to degradation under the influence of light, humidity and temperature. The chromatographic conditions were: RP-18 column of 250 mm yen 4 mm ID and a particle size of 5 mm; mobile phase of Acetonitrile-Ammonium acetate solution (0.2 M) (70:30; v/v) (pH*6) adjusted with glacial acetic acid; flow rate of 1 ml min-1; 25 degrees C of temperature; detection at 322 nm; injection volume of 20 ml, using height peak as the integration parameter. The results obtained at six months indicate that the stability of Ranitidine depends on the correct formulation and the primary container. The remaining content of Ranitidine, dissolved percentage in vitro and total impurity percentage were determined by HPLC. Organoleptic characteristics were visually examined. The proposed analytical method was validated and linearity, precision and selectivity were determined. Degradation products were detected. PMID:11680085

  8. Optimizing the trade-off between offspring number and quality in unpredictable environments: testing the role of differential androgen transfer to collared flycatcher eggs.

    PubMed

    Rice, Amber M; Vallin, Niclas; Kulma, Katarzyna; Arntsen, Hanna; Husby, Arild; Tobler, Michael; Qvarnström, Anna

    2013-05-01

    According to the brood reduction hypothesis, parents adjust their brood size in response to current environmental conditions. When resources are abundant, parents can successfully raise all hatched offspring, but when resources are scarce, brood reduction, i.e., the sacrifice of some siblings to secure the quality of a subset of offspring, may maximize fitness. Differential transfer of maternal androgens is one potential proximate mechanism through which female birds may facilitate brood reduction because it may alter the relative competitive ability of sibling nestlings. We tested the hypothesis that female collared flycatchers (Ficedula albicollis) manipulate sibling competition by transferring less androgens to eggs late in the laying sequence. We experimentally elevated androgen levels in i) whole clutches and ii) only the two last laid eggs, and compared growth and begging behavior of offspring from these treatments with a control treatment. By using three treatments and video assessment of begging, we examined the effects of within-clutch patterns of yolk androgen transfer on levels of sibling competition in situ. When androgens were elevated in only the two last laid eggs, begging was more even among siblings compared to control nests. We also found that female nestlings receiving additional yolk androgens showed higher mass gain later in the breeding season, while their male counterparts did not. Our results suggest that females may improve reproductive success in unpredictable environments by altering within-clutch patterns of yolk androgen transfer. We discuss the possibility that life-history divergence between the co-occurring collared and pied flycatcher (Ficedula hypoleuca) is amplified by patterns of yolk androgen transfer. PMID:23602767

  9. Environmental baseline conditions for impact assessment of unconventional gas exploitation: the G-Baseline project

    NASA Astrophysics Data System (ADS)

    Kloppmann, Wolfram; Mayer, Berhard; Millot, Romain; Parker, Beth L.; Gaucher, Eric; Clarkson, Christopher R.; Cherry, John A.; Humez, Pauline; Cahill, Aaron

    2015-04-01

    A major scientific challenge and an indispensible prerequisite for environmental impact assessment in the context of unconventional gas development is the determination of the baseline conditions against which potential environmental impacts on shallow freshwater resources can be accurately and quantitatively tested. Groundwater and surface water resources overlying the low-permeability hydrocarbon host rocks containing shale gas may be impacted to different extents by naturally occurring saline fluids and by natural gas emanations. Baseline assessments in areas of previous conventional hydrocarbon production may also reveal anthropogenic impacts from these activities not related to unconventional gas development. Once unconventional gas exploitation has started, the baseline may be irrevocably lost by the intricate superposition of geogenic and potential anthropogenic contamination by stray gas, formation waters and chemicals used during hydraulic fracturing. The objective of the Franco-Canadian NSERC-ANR project G-Baseline is to develop an innovative and comprehensive methodology of geochemical and isotopic characterization of the environmental baseline for water and gas samples from all three essential zones: (1) the production zone, including flowback waters, (2) the intermediate zone comprised of overlying formations, and (3) shallow aquifers and surface water systems where contamination may result from diverse natural or human impacts. The outcome will be the establishment of a methodology based on innovative tracer and monitoring techniques, including traditional and non-traditional isotopes (C, H, O, S, B, Sr, Cl, Br, N, U, Li, Cu, Zn, CSIA...) for detecting, quantifying and modeling of potential leakage of stray gas and of saline formation water mixed with flowback fluids into fresh groundwater resources and surface waters taking into account the pathways and mechanisms of fluid and gas migration. Here we present an outline of the project as well as first results from chemical and isotopic analyses on gas, fluid and solid samples collected during a baseline monitoring program at the Carbon Management Canada field research site in south-eastern Alberta, Canada.

  10. A qualitative study of internal wave ship wakes: Dependence on environmental conditions and experimental parameters

    SciTech Connect

    Mullenhoff, C.J.; Brase, J.M.

    1995-04-24

    For the past several years the UK-US Radar Ocean Imaging Program has conducted a series of field experiments with the primary purpose of gathering real aperture radar (RAR) imagery at low grazing angle of ship-generated internal wave (IW) wakes. The first observations with RAR`s were made in the 1989 Loch Linnhe experiment where it was observed that radar images at low grazing angles (LGA) of approximately six degrees had significantly higher modulation levels than SAR images made at higher grazing angles of 35 - 65 degrees. These initial observations have led to several more experiments designed to verify the phenomenon and to test its dependence on experimental and environmental conditions. A parallel effort began to develop theoretical models of the LGA imaging process. Through this series of experiments we have developed an extensive database of radar imagery and supporting environmental data. The objective of this report is twofold: (1) To describe the database and the associated space of parameters. We will look at the coverage of the parameter space within the database and at areas which should be covered. (2) To take an initial look at the dependence of qualitative modulation strength on the experimental and environmental parameters. This first look will indicate the strongest dependencies which can then be studied in more detail. Section 2 describes the experimental database and Section 3 discusses the parameter space, image quality, and their relationships based on the images in the database. In Section 4 we summarize our conclusions and make recommendations for both future analyses and experiments.

  11. Changes in fatty acid and hydrocarbon composition of zooplankton assemblages related to environmental conditions

    SciTech Connect

    Lambert, R.M.

    1989-01-01

    Changes in zooplankton fatty acid and hydrocarbon patterns are described in relation to changes in environmental conditions and species composition. The regulation of zooplankton abundance by sea nettle-ctenophore interaction was examined in a small Rhode Island coastal pond. Sea nettles were nettles were able to eliminate ctenophores from the pond and subsequently zooplankton abundance increased. During one increase in zooplankton abundance, it was found that polyunsaturated fatty acids decreased while monounsaturated fatty acids increased. It was concluded that this shift in biochemical pattern was due to food limitation. In addition, zooplankton fatty acids were used in multivariate discriminant analysis to classify whether zooplankton were from coastal or estuarine environments. Zooplankton from coastal environments were characterized by higher monounsaturate fatty acids. Zooplankton hydrocarbon composition was affected by species composition and by pollution inputs. The presence of Calanus finmarchicus was detected by increased levels of pristane.

  12. On robust regression analysis as a means of exploring environmental and operational conditions for SHM data

    NASA Astrophysics Data System (ADS)

    Dervilis, N.; Worden, K.; Cross, E. J.

    2015-07-01

    In the data-based approach to structural health monitoring (SHM), the absence of data from damaged structures in many cases forces a dependence on novelty detection as a means of diagnosis. Unfortunately, this means that benign variations in the operating or environmental conditions of the structure must be handled very carefully, lest they lead to false alarms. If novelty detection is implemented in terms of outlier detection, the outliers may arise in the data as the result of both benign and malign causes and it is important to understand their sources. Comparatively recent developments in the field of robust regression have the potential to provide ways of exploring and visualising SHM data as a means of shedding light on the different origins of outliers. The current paper will illustrate the use of robust regression for SHM data analysis through experimental data acquired from the Z24 and Tamar Bridges, although the methods are general and not restricted to SHM or civil infrastructure.

  13. On the identification and interpretation of human skin spectral responses under adverse environmental conditions.

    PubMed

    Baranoski, Gladimir V G; Chen, Tenn F

    2015-08-01

    The identification and interpretation of skin spectral responses play a central role in a wide range of biomedical engineering applications, from the noninvasive assessment of human health parameters to the location of individuals in distress during search and rescue operations. In this paper, we investigate the sensitivity of these responses to physiological changes triggered by adverse environmental conditions. Our findings, which are supported by predictive computer simulations and experimental observations reported in the scientific literature, indicate that the resulting variations of skin reflectance can be substantial. Accordingly, if not properly taken into account, they may considerably impair the efficacy of systems designed for the detection and analysis of skin signatures within and outside the visible spectral region. PMID:26736394

  14. The performance of RTK-GPS for surveying under challenging environmental conditions

    NASA Astrophysics Data System (ADS)

    Lee, I.-S.; Ge, L.

    2006-05-01

    The aim of this paper was to assess the availability of RTK GPS (Real-Time Kinematic Global Positioning Systems) under some challenging environmental conditions. Testing was performed under two of these condi-tions,i.e. a small tree-covered garden and a pylon for high-voltage electricity supply. The increase in the number of satellites had many benefits for the integer ambiguity resolution, but no significant contribution to the accuracy of RTK positions and PDOP (Precision Dilution of Position). The results of RTK testing were compared against results from Total Station surveying as a further quality check. The results indicate that integrating RTK GPS system with Total Station is favoured for surveying in urban environments.

  15. Environmental conditions impacting juvenile Chinook salmon growth off central California: An ecosystem model analysis

    NASA Astrophysics Data System (ADS)

    Fiechter, J.; Huff, D. D.; Martin, B. T.; Jackson, D. W.; Edwards, C. A.; Rose, K. A.; Curchitser, E. N.; Hedstrom, K. S.; Lindley, S. T.; Wells, B. K.

    2015-04-01

    A fully coupled ecosystem model is used to identify the effects of environmental conditions and upwelling variability on growth of juvenile Chinook salmon in central California coastal waters. The ecosystem model framework consists of an ocean circulation submodel, a biogeochemical submodel, and an individual-based submodel for salmon. Simulation results indicate that years favorable for juvenile salmon growth off central California are characterized by particularly intense early season upwelling (i.e., March through May), leading to enhanced krill concentrations during summer near the location of ocean entry (i.e., Gulf of the Farallones). Seasonally averaged growth rates in the model are generally consistent with observed values and suggest that juvenile salmon emigrating later in the season (i.e., late May and June) achieve higher weight gains during their first 90 days of ocean residency.

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

    PubMed

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

    2006-08-01

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

  17. The Impact of Different Environmental Conditions on Cognitive Function: A Focused Review

    PubMed Central

    Taylor, Lee; Watkins, Samuel L.; Marshall, Hannah; Dascombe, Ben J.; Foster, Josh

    2016-01-01

    Cognitive function defines performance in objective tasks that require conscious mental effort. Extreme environments, namely heat, hypoxia, and cold can all alter human cognitive function due to a variety of psychological and/or biological processes. The aims of this Focused Review were to discuss; (1) the current state of knowledge on the effects of heat, hypoxic and cold stress on cognitive function, (2) the potential mechanisms underpinning these alterations, and (3) plausible interventions that may maintain cognitive function upon exposure to each of these environmental stressors. The available evidence suggests that the effects of heat, hypoxia, and cold stress on cognitive function are both task and severity dependent. Complex tasks are particularly vulnerable to extreme heat stress, whereas both simple and complex task performance appear to be vulnerable at even at moderate altitudes. Cold stress also appears to negatively impact both simple and complex task performance, however, the research in this area is sparse in comparison to heat and hypoxia. In summary, this focused review provides updated knowledge regarding the effects of extreme environmental stressors on cognitive function and their biological underpinnings. Tyrosine supplementation may help individuals maintain cognitive function in very hot, hypoxic, and/or cold conditions. However, more research is needed to clarify these and other postulated interventions. PMID:26779029

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

    PubMed

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

    2016-03-01

    Wastewater from pesticide industries, agricultural or surface runoff containing pesticides and their residues has adverse environmental impacts. Present study demonstrates effect of petrochemicals and trace metals on chlorpyrifos (CP) biotransformation often released in wastewater of agrochemical industry. Biodegradation was investigated using bacterial strain Pseudomonas kilonensis SRK1 isolated from wastewater spiked with CP. Optimal environmental conditions for CP removal were CFU (306 × 10(6)), pH (8); initial CP concentration (150 mg/L) and glucose as additional carbon source. Among various organic solvents (petrochemicals) used in this study toluene has stimulatory effect on CP degradation process using SRK1, contrary to this benzene and phenol negatively inhibited degradation process. Application of metal ions (Cu (II), Fe (II) Zn (II) at low concentration (1 mg/L) took part in biochemical reaction and positively stimulated CP degradation process. Metal ions at high concentrations have inhibitory effect on degradation process. A first order growth model was shown to fit the data. It could be concluded that both type and concentration of metal ions and petrochemicals can affect CP degradation process. PMID:26692411

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

    PubMed

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

    1999-10-01

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

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

    SciTech Connect

    Runhaar, Hens; Runhaar, Piety R.; Oegema, Tammo

    2010-11-15

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

  1. The Impact of Different Environmental Conditions on Cognitive Function: A Focused Review.

    PubMed

    Taylor, Lee; Watkins, Samuel L; Marshall, Hannah; Dascombe, Ben J; Foster, Josh

    2015-01-01

    Cognitive function defines performance in objective tasks that require conscious mental effort. Extreme environments, namely heat, hypoxia, and cold can all alter human cognitive function due to a variety of psychological and/or biological processes. The aims of this Focused Review were to discuss; (1) the current state of knowledge on the effects of heat, hypoxic and cold stress on cognitive function, (2) the potential mechanisms underpinning these alterations, and (3) plausible interventions that may maintain cognitive function upon exposure to each of these environmental stressors. The available evidence suggests that the effects of heat, hypoxia, and cold stress on cognitive function are both task and severity dependent. Complex tasks are particularly vulnerable to extreme heat stress, whereas both simple and complex task performance appear to be vulnerable at even at moderate altitudes. Cold stress also appears to negatively impact both simple and complex task performance, however, the research in this area is sparse in comparison to heat and hypoxia. In summary, this focused review provides updated knowledge regarding the effects of extreme environmental stressors on cognitive function and their biological underpinnings. Tyrosine supplementation may help individuals maintain cognitive function in very hot, hypoxic, and/or cold conditions. However, more research is needed to clarify these and other postulated interventions. PMID:26779029

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

    NASA Astrophysics Data System (ADS)

    Komjáthy, E.; Mészáros, R.; Lagzi, I.

    2010-09-01

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

  3. Quantifying Preferences and Responsiveness of Marine Zooplankton to Changing Environmental Conditions using Microfluidics

    PubMed Central

    Merten, Christoph A.; Arendt, Detlev

    2015-01-01

    Global environmental change significantly affects marine species composition. However, analyzing the impact of these changes on marine zooplankton communities was so far mostly limited to assessing lethal doses through mortality assays and hence did not allow a direct assessment of the preferred conditions, or preferendum. Here, we use a microfluidic device to characterize individual behavior of actively swimming zooplankton, and to quantitatively determine their ecological preferendum. For the annelid zooplankton model Platynereis dumerilii we observe a broader pH preferendum than for the copepod Euterpina acutifrons, and reveal previously unrecognized sub-populations with different pH preferenda. For Platynereis, the minimum concentration difference required to elicit a response (responsiveness) is ~1 μM for H+ and ~13.7 mM for NaCl. Furthermore, using laser ablations we show that olfactomedin-expressing sensory cells mediate chemical responsiveness in the Platynereis foregut. Taken together, our microfluidic approach allows precise assessment and functional understanding of environmental perception on planktonic behaviour. PMID:26517120

  4. Interactions of environmental conditions and mechanical loads have influence on matrix turnover by nucleus pulposus cells.

    PubMed

    Neidlinger-Wilke, Cornelia; Mietsch, Antje; Rinkler, Christina; Wilke, Hans-Joachim; Ignatius, Anita; Urban, Jill

    2012-01-01

    Disc degeneration is associated with several changes in the physicochemical environment of intervertebral disc cells. Nucleus pulposus (NP) cells in the center of degenerated discs are exposed to decreased glucose supply, osmolarity, pH, and oxygen levels. To understand the complexity of these interactions on a cellular level, we designed standardized experiments in which we compared responses to these environmental factors under normal levels with those seen under two different degrees of disc degeneration. We hypothesized that these changes in environmental stimuli influence gene expression of matrix proteins and matrix degrading enzymes and alter their responses to cyclic hydrostatic pressure (HP). Our results suggest that a simulation of degenerative conditions influences the degradation of disc matrix through impairing matrix formation and accelerating matrix resorption via up- or down-regulation of the respective target genes. The greatest effects were seen for decreases in glucose concentration and pH. Low oxygen had little influence. HP had little direct effect but appeared to counteract matrix degradation by reducing or inverting some of the adverse effects of other stimuli. For ongoing in vitro studies, interactions between mechanical stimuli and factors in the physicochemical environment should not be ignored as these could markedly influence results. PMID:21674606

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

    PubMed Central

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

    2002-01-01

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

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

    PubMed Central

    Tardieu, François

    2013-01-01

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

  7. Nitrous Oxide Production and Fluxes from Coastal Sediments under Varying Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Ziebis, W.; Wankel, S. D.; de Beer, D.; Dentinger, J.; Buchwald, C.; Charoenpong, C.

    2014-12-01

    Although coastal zones represent important contributors to the increasing levels of atmospheric nitrous oxide (N2O), it is still unclear which role benthic processes play and whether marine sediments represent sinks or sources for N2O, since interactions among closely associated microbial groups lead to a high degree of variability. In addition, coastal areas are extremely dynamic regions, often exposed to increased nutrient loading and conditions of depleted oxygen. We investigated benthic N2O fluxes and how environmental conditions affect N2O production in different sediments at 2 different geographical locations (German Wadden Sea, a California coastal lagoon). At each location, a total of 32 sediment cores were taken in areas that differed in sediment type, organic content and pore-water nutrient concentrations, as well as in bioturbation activity. Parallel cores were incubated under in-situ conditions, low oxygen and increased nitrate levels for 10 days. Zones of N2O production and consumption were identified in intact cores by N2O microprofiles at the beginning and end of the experiments. In a collaborative effort to determine the dominant sources of N2O, samples were taken throughout the course of the experiments for the determination of the isotopic composition of N2O (as well as nitrate, nitrite and ammonium). Our results indicate that both, nitrate addition and low oxygen conditions in the overlying water, caused an increase of subsurface N2O production in most sediments, with a high variability between different sediment types. N2O production in the sediments was accompanied by N2O consumption, reducing the fluxes to the water column. In general, organic rich sediments showed the strongest response to environmental changes with increased production and efflux of N2O into the overlying water. Bioturbation activity added to the complexity of N2O dynamics by an increase in nitrification-denitrification processes, as well as enhanced pore-water transport. The results will be used in a metabolic modeling approach that will allow numerical simulation and prediction of sedimentary N2O dynamics.

  8. Female Weddell seals show flexible strategies of colony attendance related to varying environmental conditions.

    PubMed

    Chambert, Thierry; Rotella, Jay J; Garrott, Robert A

    2015-02-01

    Many animal life cycles involve movements among different habitats to fulfill varying resource demands. There are inherent costs associated with such movements, and the decision to leave or stay at a given location ought to be motivated by the benefits associated with potential target habitats. Because movement patterns, especially those associated with reproduction, can have important implications for the success (survival, reproduction) of individual animals, and therefore a population's dynamics, it is important to identify and understand their sources of variation (environmental and individual). Here, using a mark-recapture, multistate modeling approach, we investigated a set of a priori hypotheses regarding sources and patterns of variation in breeding-colony attendance for Weddell seal (Leptonychotes weddellii) females on sabbatical from pup production. For such females, colony attendance might be motivated by predation avoidance and positive social interactions related to reproduction, but some costs, such as reduced foraging opportunities or aggressive interactions with conspecifics, might also exist. We expected these benefits and costs to vary with a female's condition and the environment. Results revealed that the probability of being absent from colonies was higher (1) in years when the extent of local sea ice was larger, (2) for the youngest and oldest individuals, and (3) for females with less reproductive experience. We also found substantial levels of residual individual heterogeneity in these rates. Based on our a priori predictions, we postulate that the decision to attend breeding colonies or not is directly influenced by an individual's physiological condition, as well as by the ice-covered distance to good foraging areas, availability of predator-free haul-out sites, and the level of negative interactions with conspecifics inside colonies. Our results support the idea that in iteroparous species, and colonial animals in particular, seasonal and temporary movements from/to reproductive sites represent flexible behavioral strategies that can play an important role in coping with environmental variability. PMID:26240869

  9. Adaptations of the Secretome of Candida albicans in Response to Host-Related Environmental Conditions.

    PubMed

    Klis, Frans M; Brul, Stanley

    2015-12-01

    The wall proteome and the secretome of the fungal pathogen Candida albicans help it to thrive in multiple niches of the human body. Mass spectrometry has allowed researchers to study the dynamics of both subproteomes. Here, we discuss some major responses of the secretome to host-related environmental conditions. Three β-1,3-glucan-modifying enzymes, Mp65, Sun41, and Tos1, are consistently found in large amounts in culture supernatants, suggesting that they are needed for construction and expansion of the cell wall β-1,3-glucan layer and thus correlate with growth and might serve as diagnostic biomarkers. The genes ENG1, CHT3, and SCW11, which encode an endoglucanase, the major chitinase, and a β-1,3-glucan-modifying enzyme, respectively, are periodically expressed and peak in M/G1. The corresponding protein abundances in the medium correlate with the degree of cell separation during single-yeast-cell, pseudohyphal, and hyphal growth. We also discuss the observation that cells treated with fluconazole, or other agents causing cell surface stress, form pseudohyphal aggregates. Fluconazole-treated cells secrete abundant amounts of the transglucosylase Phr1, which is involved in the accumulation of β-1,3-glucan in biofilms, raising the question whether this is a general response to cell surface stress. Other abundant secretome proteins also contribute to biofilm formation, emphasizing the important role of secretome proteins in this mode of growth. Finally, we discuss the relevance of these observations to therapeutic intervention. Together, these data illustrate that C. albicans actively adapts its secretome to environmental conditions, thus promoting its survival in widely divergent niches of the human body. PMID:26453650

  10. Adaptations of the Secretome of Candida albicans in Response to Host-Related Environmental Conditions

    PubMed Central

    Brul, Stanley

    2015-01-01

    The wall proteome and the secretome of the fungal pathogen Candida albicans help it to thrive in multiple niches of the human body. Mass spectrometry has allowed researchers to study the dynamics of both subproteomes. Here, we discuss some major responses of the secretome to host-related environmental conditions. Three β-1,3-glucan-modifying enzymes, Mp65, Sun41, and Tos1, are consistently found in large amounts in culture supernatants, suggesting that they are needed for construction and expansion of the cell wall β-1,3-glucan layer and thus correlate with growth and might serve as diagnostic biomarkers. The genes ENG1, CHT3, and SCW11, which encode an endoglucanase, the major chitinase, and a β-1,3-glucan-modifying enzyme, respectively, are periodically expressed and peak in M/G1. The corresponding protein abundances in the medium correlate with the degree of cell separation during single-yeast-cell, pseudohyphal, and hyphal growth. We also discuss the observation that cells treated with fluconazole, or other agents causing cell surface stress, form pseudohyphal aggregates. Fluconazole-treated cells secrete abundant amounts of the transglucosylase Phr1, which is involved in the accumulation of β-1,3-glucan in biofilms, raising the question whether this is a general response to cell surface stress. Other abundant secretome proteins also contribute to biofilm formation, emphasizing the important role of secretome proteins in this mode of growth. Finally, we discuss the relevance of these observations to therapeutic intervention. Together, these data illustrate that C. albicans actively adapts its secretome to environmental conditions, thus promoting its survival in widely divergent niches of the human body. PMID:26453650

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

    NASA Astrophysics Data System (ADS)

    Orru, M.; Orru, H.

    2009-04-01

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

  12. Testing the Sensitivity of Extratropical Cyclones to Variations in Environmental Conditions

    NASA Astrophysics Data System (ADS)

    Tierney, G.; Booth, J. F.; Posselt, D. J.

    2014-12-01

    Extratropical cyclones are a main driver of mid-latitude weather conditions, continually interacting with their synoptic and mesoscale environment. These systems are a product of the cyclogenetic environment in which they develop, and their associated circulation, latent heating, and radiative heating in turn exert significant influence on the near and far-field dynamic and thermodynamic state. With the projected warming to our climate system, the environments in which mid-latitude cyclones develop are changing, as are the controlling influences on storm characteristics: temperature, moisture content, jet strength, and baroclinicity. Feedbacks between changes in the initial environment and changes in extratropical cyclone properties represent a challenge to our ability to characterize the effects of changes in climate on the winds and rainfall produced by these storms. In this presentation, we consider how extratropical cyclones might respond to simultaneous changes in multiple environmental factors. We utilize an idealized version of the Weather Research and Forecasting model (WRF), allowing for systematic control of environmental conditions. We perform a comprehensive ensemble analysis by tracking the variations in extratropical cyclone properties as a function of the changes in the surrounding environment, with the aim of identifying key controls on cyclone characteristics. We consider the socially relevant impacts of changes in dynamics and precipitation, as well as considering the climatologically relevant impacts of changes in cloud and radiative properties. We identify and implement tunable variables best approximating changes in temperature, moisture content, jet strength, and baroclinicity. Examining the effects of each variable with single-variable sensitivity tests, we document the effect of each variable alone, before filling out a multivariate parameter space by combining variations of two or more variables. In reviewing the multivariate results, we use the single-variable functions to untangle potential feedbacks in the system, teasing out relationships and interactions between our tunable variables and their effects on the entire system.

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

    PubMed Central

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

    1993-01-01

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

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

    PubMed

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

    2015-01-01

    An experiment was conducted to evaluate the effect of litter thickness on growth performance, immune status, environmental condition, and welfare quality in yellow broilers. In total, 1,800 one-day-old Suqin yellow broilers were raised for 21 d. On d 22, 1,600 birds of similar BW (404±12 g) were randomly selected and placed into 20 indoor pens (8 birds/m2, 10 m2/pen). These birds were assigned to a litter treatment of 4, 8, 12, and 16 cm. Each treatment was repeated in five pens. The results showed that a thicker litter was related to increased BW, daily weight gain, and daily feed intake (P<0.001). Feed conversion ratio and mortality were unaffected by litter thickness (P=0.320, P=0.353, respectively). Absolute and relative liver weights showed a significant linear response to increasing litter thickness (P=0.01, P=0.001, respectively). The litter moisture content, air ammonia, and CO2 content decreased, whereas the air dust content increased with increasing litter thickness (P<0.001, P=0.017, P=0.033, P<0.001, respectively). Litter thickness had no effect on gait, plumage damage, hock burn or breast skin crusting (P = 0.076, P=0.964, P=0.131, P=0.401, respectively). Plumage cleanliness, foot pad dermatitis, hock swelling and breast blister varied significantly with litter thickness (P=0.027, P=0.011, P=0.014, P=0.042, respectively). The results of this study suggest that an increasing litter thickness has a beneficial effect on the growth performance, environmental condition and welfare of birds. PMID:25577790

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

    PubMed

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

    2015-01-01

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

  16. Control of Saccharomyces cerevisiae pre-tRNA processing by environmental conditions.

    PubMed

    Foretek, Dominika; Wu, Jingyan; Hopper, Anita K; Boguta, Magdalena

    2016-03-01

    tRNA is essential for translation and decoding of the proteome. The yeast proteome responds to stress and tRNA biosynthesis contributes in this response by repression of tRNA transcription and alterations of tRNA modification. Here we report that the stress response also involves processing of pre-tRNA 3' termini. By a combination of Northern analyses and RNA sequencing, we show that upon shift to elevated temperatures and/or to glycerol-containing medium, aberrant pre-tRNAs accumulate in yeast cells. For pre-tRNAUAU (Ile) and pre-tRNAUUU (Lys) these aberrant forms are unprocessed at the 5' ends, but they possess extended 3' termini. Sequencing analyses showed that partial 3' processing precedes 5' processing for pre-tRNAUAU (Ile). An aberrant pre-tRNA(Tyr) that accumulates also possesses extended 3' termini, but it is processed at the 5' terminus. Similar forms of these aberrant pre-tRNAs are detected in the rex1? strain that is defective in 3' exonucleolytic trimming of pre-tRNAs but are absent in the lhp1? mutant lacking 3' end protection. We further show direct correlation between the inhibition of 3' end processing rate and the stringency of growth conditions. Moreover, under stress conditions Rex1 nuclease seems to be limiting for 3' end processing, by decreased availability linked to increased protection by Lhp1. Thus, our data document complex 3' processing that is inhibited by stress in a tRNA-type and condition-specific manner. This stress-responsive tRNA 3' end maturation process presumably contributes to fine-tune the levels of functional tRNA in budding yeast in response to environmental conditions. PMID:26729922

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

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

  18. Environmental conditions of the Laptev Sea region in the late postglacial time

    NASA Astrophysics Data System (ADS)

    Naidina, O. D.

    2016-01-01

    The comparison between the first results of comprehensive micropaleontological analysis (pollen, spores, foraminifera, and ostracods) and those of radiocarbon dating (AMS14C) for the sediments of the eastern inner shelf of the Laptev Sea (the core collected from depth of 37 m) indicates that considerable changes in natural conditions in the sea and on land coincide in time and refer to the time period of 1500-1700 years B.P. This period is characterized by changes in microfossils: appearance of thermophilic pollen and planktonic foraminifera and increase in total number of benthic foraminifera and ostracods. Intense warming and humidification of the climate reconstructed for this 200-year period promoted the expansion of large-shrub tundra. Summer air temperatures were lower than that in the peak mid-Holocene climatic optimum by 2°-3°C, but 1°C higher than the present-day temperature. An estuary freshwater basin developed: it was strongly affected by river discharge, but North Atlantic waters also intensely penetrated here in short-term intervals. In general, the studied microfossil complex reflects the relatively stable environmental conditions and decrease in seawater salinity in the eastern part of the Laptev Sea shelf during the last 2300 years.

  19. Controlled particle removal from surfaces by electrodynamic methods for terrestrial, lunar, and Martian environmental conditions

    NASA Astrophysics Data System (ADS)

    Calle, C. I.; Mazumder, M. K.; Immer, C. D.; Buhler, C. R.; Clements, J. S.; Lundeen, P.; Chen, A.; Mantovani, J. G.

    2008-12-01

    An Electrodynamic Dust Shield to remove already deposited micron-size particles from surfaces and to prevent the accumulation of such particles on surfaces has been developed. In addition to terrestrial application, our NASA laboratory is adapting this technology for the dusty and harsh environments of the Moon and Mars. The Apollo missions to the moon showed that lunar dust can hamper astronaut surface activities due to its ability to cling to most surfaces. NASA's Mars exploration landers and rovers have also shown that the problem is equally hard if not harder on Mars. In this paper, we show that an appropriate design can prevent the electrostatic breakdown at the low Martian atmospheric pressures. We are also able to show that uncharged dust can be lifted and removed from surfaces under simulated Martian environmental conditions. This technology has many potential benefits for removing dust from visors, viewports and many other surfaces as well as from solar arrays. We have also been able to develop a version of the electrodynamic dust shield working under hard vacuum conditions. This version should work well on the moon. We present data on the design and optimization of both types of dust shields as well substantial data on the clearing factors for transparent dust shields designed to protect solar panels for Martian exploration.

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

    PubMed

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

    2007-07-01

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

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

    PubMed

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

    2013-08-01

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

  2. [Protein synthesis-dependent reactivation of environmental conditioned reflex in terrestrial snails].

    PubMed

    Ga?nutdinova, T Kh; Tagirova, R R; Ismailova, A I; Muranova, L N; Ga?nutdinov, Kh L; Balaban, P M

    2004-01-01

    We investigated influence of anisomycine injection on reconsolidation of contextual memory after development of environmental conditioned reflex in terrestrial snail Helix. Testing the amplitude of behavioral reactions (tentacle withdrawal) in response to standard tactile stimulation of the skin in two contexts: a) when the snail was fixed by the shell and was moving on the surface of the ball floating in water, or b) was moving on the flat surface of glass terrarium, has shown no difference in response amplitudes. After a session of electric shocks (5 days) in one context only (ball) the associative learning was clearly observed as the significant difference of response amplitudes in two contexts. On the other day following testing was performed a session of "reminding", immediately after which the snails were injected by anisomycine (control snails were injected by saline solution). Testing has shown that injection of anisomycine led to impairment of the context conditioning. Results suggest that the mechanisms of consolidation of new memory and memory reconsolidation after retrieval are not identical. PMID:15658044

  3. Reconstruction of baseline time-trace under changing environmental and operational conditions

    NASA Astrophysics Data System (ADS)

    Aryan, P.; Kotousov, A.; Ng, C. T.; Wildy, S.

    2016-03-01

    Compensation of changing environmental and operational conditions (EOC) is often necessary when using guided-wave based techniques for structural health monitoring in real-world applications. Many studies have demonstrated that the effect of changing EOC can mask damage to a degree that a critical defect might not be detected. Several effective strategies, specifically for compensating the temperature variations, have been developed in recent years. However, many other factors, such as changing humidity and boundary conditions or degradation of material properties, have not received much attention. This paper describes a practical method for reconstruction of the baseline time-trace corresponding to the current EOC. Thus, there is no need for differentiation or compensation procedures when using this method for damage diagnosis. It is based on 3D surface measurements of the velocity field near the actuator using laser vibrometry, in conjunction with high-fidelity finite element simulations of guided wave propagation in free from defects structure. To demonstrate the feasibility and efficiency of the proposed method we provide several examples of the reconstruction and damage detection.

  4. Precursor Environmental Conditions Associated with the Termination of Madden-Julian Oscillation Events

    NASA Astrophysics Data System (ADS)

    Stachnik, J. P.; Waliser, D. E.; Majda, A.

    2014-12-01

    Current generations of global climate models continue to struggle with simulating many of the observed features of the Madden-Julian oscillation (MJO) and suffer from low skill regarding initiation forecasts. While recent work has focused on those mechanisms thought to be important for MJO initiation, fewer studies have examined the large-scale conditions associated with quiescent periods of the MJO and the decay of existing events. Understanding these mechanisms may provide a valuable context toward improving simulations of MJO initiation and propagation in climate and operational weather forecast models. This study presents an analysis of the precursor environmental conditions related to the termination of MJO events. A simple climatology is created using a real-time MJO monitoring index, documenting the locations and frequencies of MJO decay. Lead-lag composites of several atmospheric variables including temperature, moisture, and intraseasonal wind anomalies are generated from three reanalyses. Long-term, lower tropospheric moisture deficits over the local domain best identify terminating events over the Indian Ocean, with a northward shift of the Intertropical Convergence Zone (ITCZ) and corresponding lead times as much as 20 days prior to MJO decay. Statistically significant differences are also identified more than 10 days in advance of MJO termination events in the west Pacific, though the vertical velocity and moisture anomalies are more symmetric about the equator. We also present results for those MJOs that terminate over the maritime continent. Unlike the Indian Ocean and west Pacific, the likelihood of an MJO to cross the maritime continent appears related to its own intensity, rather than the upstream environmental conditions, with only the strongest MJOs propagating into the warm pool region. Finally, a budget analysis is performed on the three-dimensional moisture advection equation in order to better elucidate what time-scales and physical mechanisms are most important for MJO termination. The combination of intraseasonal vertical circulation anomalies coupled with the mean state specific humidity best explain the anomalous moisture patterns associated with MJO termination, suggesting that the upstream influence of the MJO circulation can eventually lead to its own demise.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2005-05-01

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

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

    PubMed

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

    2014-11-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2013-12-01

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

  10. Climatic and environmental conditions favoring the crossing of the Carpathians by early Neolithic populations

    NASA Astrophysics Data System (ADS)

    Perşoiu, Ioana; Perşoiu, Aurel

    2015-04-01

    The study of the origin and spread of Neolithic has been the subject of heated debate since the early studies of Childe (1942). To what extent the dispersal process was influenced by environmental factors is still debated, one of the issues being whether climatic conditions influencing agricultural practices, could have influenced the dispersal route, "blocking" some of the Neolithic societies in front of ecological barriers. Data from Neolithic sites in SE Europe shows that a continuous stream of people and cultures flowed through the Danube's Iron Gates towards Central Europe, while in the eastern part of Europe this process was delayed, people and cultures "moving" around the Carpathians and crossing them with a delay of ca. 1000 years. One of the possible avenues for this crossing is the floodplain of Someşu Mic River (Transylvanian depression), home to the oldest (~8500 cal. BP) Neolithic settlement in Romania. In this paper, we review the climatic and environmental changes that affected the region at the time of Neolithic dispersal. Pollen and stable isotopes in cave ice indicate an early Holocene rapid warming during summer months, peaking around 7 ka cal. BP; and a delayed warming for autumn and winter months, peaking at 5 ka cal. BP, both followed by a continuous cooling trend towards the present. Someşu Mic River developed and maintained a narrow sinuous channel during the Holocene, with local development of meanders and anabranches, in response to both climatic and geologic controlling factors. Archaeological finds in the floodplain and the lower terraces suggest that human societies in the region responded in sensitive manner to these climatic and environmental changes. During warm and dry periods, with low fluvial activity, the number of settlements increased in the floodplain's perimeter, while during the short cold and humid periods, the number of settlements rapidly increased on the lower terraces and on the valley slopes, disappearing from the flooded valley bottom and flash-flood prone alluvial fans. Our results suggest that once reaching the foothills of the Carpathian Mts., early Neolithic communities encountered a forested landscape and rather than clearing it for agriculture, they have moved along the middle Danube towards Pannonia and Central Europe, as well as along the lower reaches of the Danube's tributaries, following the most suitable and easily accessible terrain for agriculture practices.

  11. Environmental Conditions Affect Exhalation of H3N2 Seasonal and Variant Influenza Viruses and Respiratory Droplet Transmission in Ferrets

    PubMed Central

    Gustin, Kortney M.; Belser, Jessica A.; Veguilla, Vic; Zeng, Hui; Katz, Jacqueline M.; Tumpey, Terrence M.; Maines, Taronna R.

    2015-01-01

    The seasonality of influenza virus infections in temperate climates and the role of environmental conditions like temperature and humidity in the transmission of influenza virus through the air are not well understood. Using ferrets housed at four different environmental conditions, we evaluated the respiratory droplet transmission of two influenza viruses (a seasonal H3N2 virus and an H3N2 variant virus, the etiologic virus of a swine to human summertime infection) and concurrently characterized the aerosol shedding profiles of infected animals. Comparisons were made among the different temperature and humidity conditions and between the two viruses to determine if the H3N2 variant virus exhibited enhanced capabilities that may have contributed to the infections occurring in the summer. We report here that although increased levels of H3N2 variant virus were found in ferret nasal wash and exhaled aerosol samples compared to the seasonal H3N2 virus, enhanced respiratory droplet transmission was not observed under any of the environmental settings. However, overall environmental conditions were shown to modulate the frequency of influenza virus transmission through the air. Transmission occurred most frequently at 23°C/30%RH, while the levels of infectious virus in aerosols exhaled by infected ferrets agree with these results. Improving our understanding of how environmental conditions affect influenza virus infectivity and transmission may reveal ways to better protect the public against influenza virus infections. PMID:25969995

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

    NASA Astrophysics Data System (ADS)

    Vario, C.; Friedland, A.

    2012-12-01

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

  13. Effect of environmental conditions on the spectroscopic signature of DNT in sand

    NASA Astrophysics Data System (ADS)

    Blanco, Alejandro; Mina, Nairmen; Castro, Miguel E.; Castillo-Chara, Jairo; Hernandez-Rivera, Samuel P.

    2005-06-01

    Landmines have been a part of war technology for many years. As a result of the continued and indiscriminate use in approximately 90 countries landmines pose a severe and ever growing problem and a daily risk. Raman Spectroscopy is capable of providing rich information about the molecular structure of the sample and pinpoint detection of many chemicals, both of organic and inorganic nature. The presence of landmines in soils can be detected by Raman Spectroscopy sensing in a Point Detection modality, using characteristic vibrational signals of each explosive present in landmines. Detection of 2,4-DNT in sand and studies on how the vibrational signatures of 2,4-DNT is modified by interacting with soil particles and environmental conditions is reported. Raman Microspectrometers equipped with 514 nm and 785 nm laser excitation lines were used. The work focused in how the spectroscopic signatures of DNT in contact with Ottawa Sand are affected by the presence of humidity, pH, temperature, UV light and reaction times. Samples of mixtures of sand/2,4-DNT were analyzed by Raman Spectroscopy at 10, 50 and 100% water content and temperatures in range of 40-80 °C. Mixtures were also analyzed at different pH: 4, 7 and 10 and under ultraviolet light at 254 nm. Raman spectra were taken as a function of time in an interval from 24 to 336 hours (two weeks). Characteristic signals of 2,4-DNT were analyzed in different ranges 100-3800 cm-1, 600-1200 cm-1, 300-1700 cm-1 and 2800-3500 cm-1. The effect of these variables was measured during 45 consecutive days. It was confirmed that the decrease of characteristic vibrational signatures of 2,4-DNT can be attributed to increase of the degradation of 2,4-DNT by the simulated environmental conditions. Spectroscopic characterization of degradation products, both in contact with sand as well as airborne is under way. These results will make possible the development of highly sensitive sensors for detection of explosives materials and correlated with their degradation products in landmines.

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

    PubMed

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

    2011-07-01

    This study evaluated alternative protocols for culturing thermophilic campylobacters in environmental water. All samples were filtered through a sterile 0.45?m pore-size membrane, which was then incubated in Preston enrichment broth. Four variables were compared: water sample volume (2000mL vs. 500mL), enrichment broth volume (25mL vs. 100mL), enrichment incubation duration (24h vs. 48h), and number of enrichment passages (one vs. two). In addition, DNA extracts were prepared from all final broths and analyzed using three rRNA PCR assays. River water was collected at 3 sampling sites weekly for 9 weeks. Among these 27 collections, 25 (93%) yielded Campylobacter spp. under at least one of the 16 culture conditions. By univariate analysis, yields were significantly better for the 2000mL sample volume (68.5% vs. 43.0%, p<0.0001) and the 25mL enrichment broth volume (64.5% vs. 47.0%, p<0.0004). Neither of the enrichment period had a significant effect, although there was a trend in favor of 48h incubation (59.5% vs. 52.0%, p=0.13). The three PCR methods gave concordant results for 66 (33%) of the culture-negative samples and 103 (50%) of the culture-positive samples. Compared with culture results, Lubeck's 16S PCR assay had the best performance characteristics, with a sensitivity of 82% and a specificity of 94%. Of the 12 culture-negative samples positive by Lubeck's PCR assay, 11 (92%) samples were also positive by Denis' 16S PCR assay, suggesting that in these cases the culture might have been falsely negative. Based on our results, we conclude that the optimal conditions for detecting Campylobacter spp. in natural waters include 2000mL sample volume and a single enrichment broth of 25mL PB incubated for 48h. PMID:21504767

  15. Microbial diversity during cellulose decomposition in different forest stands: I. microbial communities and environmental conditions.

    PubMed

    Kubartová, Ariana; Moukoumi, Judicaël; Béguiristain, Thierry; Ranger, Jacques; Berthelin, Jacques

    2007-10-01

    We studied the effect of forest tree species on a community of decomposers that colonize cellulose strips. Both fungal and bacterial communities were targeted in a native forest dominated by beech and oak and 30-year-old beech and spruce plantations, growing in similar ecological conditions in the Breuil-Chenue experimental forest site in Morvan (France). Microbial ingrowths from the 3rd to 10th month of strip decomposition (May to December 2004) were studied. Community composition was assessed using temperature gradient gel electrophoresis with universal fungal (ITS1F, ITS2) and bacterial (1401r, 968f) primers. Soil temperature and moisture as well as fungal biomass were also measured to give additional information on decomposition processes. Changing the dominant tree species had no significant influence in the number of decomposer species. However, decomposer community composition was clearly different. If compared to the native forest, where community composition highly differed, young monocultures displayed similar species structure for fungi and bacteria. Both species numbers and community composition evolved during the decay process. Time effect was found to be more important than tree species. Nevertheless, the actual environmental conditions and seasonal effect seemed to be even more determining factors for the development of microbial communities. The course and correlations of the explored variables often differed between tree species, although certain general trends were identified. Fungal biomass was high in summer, despite that species richness (SR) decreased and conversely, that high SR did not necessarily mean high biomass values. It can be concluded that the growth and development of the microbiological communities that colonized a model material in situ depended on the combination of physical and biological factors acting collectively and interdependently at the forest soil microsite. PMID:17609845

  16. Simulation of the environmental climate conditions on martian surface and its effect on Deinococcus radiodurans

    NASA Astrophysics Data System (ADS)

    de la Vega, U. Pogoda; Rettberg, P.; Reitz, G.

    The resistance of terrestrial microorganisms under the thermo-physical conditions of Mars (diurnal temperature variations, UV climate, atmospheric pressure and gas composition) at mid-latitudes was studied for the understanding and assessment of potential life processes on Mars. In order to accomplish a targeted search for life on other planets, e.g. Mars, it is necessary to know the limiting physical and chemical parameters of terrestrial life. Therefore the polyextremophile bacterium Deinococcus radiodurans was chosen as test organism for these investigations. For the simulation studies at the Planetary and Space Simulation Facilities (PSI) at DLR, Cologne, Germany, conditions that are present during the southern summer at latitude of 60° on Mars were applied. We could simulate several environmental parameters of Mars in one single experiment: vacuum/low pressure, anoxic atmosphere and diurnal cycles in temperature and relative humidity, energy-rich ultraviolet (UV) radiation as well as shielding by different martian soil analogue materials. These parameters have been applied both single and in different combinations in laboratory experiments. Astonishingly the diurnal Mars-like cycles in temperature and relative humidity affected the viability of D. radiodurans cells quite severely. But the martian UV climate turned out to be the most deleterious factor, though D. radiodurans is red-pigmented due to carotenoids incorporated in its cell wall, which have been assigned not only a possible role as free radical scavenger but also as a UV-protectant. An additional UV-protection was accomplished by mixing the bacteria with nano-sized hematite.

  17. Innovative monitoring campaign of the environmental conditions of the Stibbert museum in Florence

    NASA Astrophysics Data System (ADS)

    Angelini, E.; Civita, F.; Corbellini, S.; Fulginiti, D.; Giovagnoli, A.; Grassini, S.; Parvis, M.

    2016-02-01

    Conservation of ancient metallic artefact displayed inside museums is a complex problem due to the large number of constraints mainly related to the artefacts fruition by people. The development of a simple procedure for monitoring the artefact conservation state promptly highlighting risky conditions without impacting on the normal museum operations could be of interest in the cultural heritage world. This paper describes the interesting results obtained by using a highly sensitive and innovative methodology for evaluating the safety level of the museum indoor areas, and more specifically of the interior of the showcases, with respect to the metallic artefacts. The methodology is based on the use of an innovative smart sensors network and of copper reference samples. The smart sensors network was employed for the continuous monitoring of temperature and relative humidity close to the artefacts, i.e. inside the display showcases. The reference specimens were Cu coated with a 100 nm Cu nanostructured layer put for 1 year in the exhibition rooms inside and outside the showcases and characterised by means of normal imaging, colorimetric and FESEM techniques at regular intervals. The results of the monitoring activity evidenced the higher reactivity to the environmental aggressivity of the nanocoated copper specimen with respect to bulk artefacts and therefore the possibility to use them as alerts to possible corrosion phenomena that may occur to the real artefacts. A proper temperature and relative humidity monitoring inside the showcases and close to each group of artefacts is a powerful though economic and non-invasive way to highlight most of the possible critical display conditions.

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

    PubMed Central

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

    2013-01-01

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

  19. Old males reduce melanin-pigmented traits and increase reproductive outcome under worse environmental conditions in common kestrels.

    PubMed

    Lopez-Idiaquez, David; Vergara, Pablo; Fargallo, Juan Antonio; Martinez-Padilla, Jesús

    2016-02-01

    Secondary sexual traits displayed by males and females may have evolved as a signal of individual quality. However, both individual quality and investment on producing or maintaining enhanced sexual traits change as individuals age. At the same time, the costs associated to produce sexual traits might be attenuated or increased if environmental conditions are benign or worse respectively. Accordingly, environmental conditions are expected to shape the association between the expression of sexual traits and their reproductive outcome as individuals age. Nonetheless, little is known about the environmental influence on the co-variation between sexual traits and reproductive outcome throughout the life of individuals. We studied the age-dependency of the number and size of back spots, a melanin-based and sexual trait in adults of common kestrels (Falco tinnunculus). We analysed the age-dependence of reproductive traits and the environmental influence, defined as vole abundance, using a 10-year individual-based dataset. We broke down age-related changes of reproductive traits into within- and between-individual variation to assess their contribution to population-level patterns. Our results showed a within-individual decrease in the number, but not the size, of back spots in males. The size of back spots was positively correlated with food availability in males. Reproductive performance of males increased as they aged, in agreement with the life-history theory but depending of vole abundance. Remarkably, we found that having fewer back spots was positively associated with clutch size only for old individuals under low-food conditions. We suggest that environmental variation may shape the association between the expression of a sexual signal and reproductive outcome. We speculate that the reliability of sexual traits is higher when environmental conditions are poor only for old individuals. Within an evolutionary context, we suggest that the expression of sexual traits might be constrained by environmental conditions at later stages of life. PMID:26941948

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  1. Modelling stream-fish functional traits in reference conditions: regional and local environmental correlates.

    PubMed

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

    2012-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  3. Non-coding RNAs in marine Synechococcus and their regulation under environmentally relevant stress conditions

    PubMed Central

    Gierga, Gregor; Voss, Björn; Hess, Wolfgang R

    2012-01-01

    Regulatory small RNAs (sRNAs) have crucial roles in the adaptive responses of bacteria to changes in the environment. Thus far, potential regulatory RNAs have been studied mainly in marine picocyanobacteria in genetically intractable Prochlorococcus, rendering their molecular analysis difficult. Synechococcus sp. WH7803 is a model cyanobacterium, representative of the picocyanobacteria from the mesotrophic areas of the ocean. Similar to the closely related Prochlorococcus it possesses a relatively streamlined genome and a small number of genes, but is genetically tractable. Here, a comparative genome analysis was performed for this and four additional marine Synechococcus to identify the suite of possible sRNAs and other RNA elements. Based on the prediction and on complementary microarray profiling, we have identified several known as well as 32 novel sRNAs. Some sRNAs overlap adjacent coding regions, for instance for the central photosynthetic gene psbA. Several of these novel sRNAs responded specifically to environmentally relevant stress conditions. Among them are six sRNAs changing their accumulation level under cold stress, six responding to high light and two to iron limitation. Target predictions suggested genes encoding components of the light-harvesting apparatus as targets of sRNAs originating from genomic islands and that one of the iron-regulated sRNAs might be a functional homolog of RyhB. These data suggest that marine Synechococcus mount adaptive responses to these different stresses involving regulatory sRNAs. PMID:22258101

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

    USGS Publications Warehouse

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

    1994-01-01

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

  5. Levels of (±) Abscisic Acid and Xanthoxin in Spinach under Different Environmental Conditions 1

    PubMed Central

    Zeevaart, Jan A. D.

    1974-01-01

    The levels of the growth inhibitors(+)-abscisic acid and xanthoxin were determined in the long day plant spinach (Spinacia oleracea L. cv. Savoy Hybrid 612) grown under different environmental conditions. When plants were transferred from light to darkness, the (+)-abscisic acid level always decreased, whereas the xanthoxin content did not change. The (+)-abscisic acid content was higher in plants grown under low than under high relative humidity. Xanthoxin levels were not affected by photoperiod, whereas the (+)-abscisic acid content increased 2 to 3 times upon transferring plants from short day to long day. Shoot tips with young leaves and mature leaves of the same plants analyzed separately did not differ in their inhibitor content when expressed per unit dry weight. No increase in xanthoxin level was observed in wilting plants. In general, the xanthoxin levels of spinach were much less affected by changes in the environment than were those of (+)-abscisic acid. In conclusion, there is no correlation between xanthoxin and (+)-abscisic acid levels in spinach on the one hand, and growth and flowering responses on the other. PMID:16658759

  6. Environmental fate of endocrine-disrupting dimethyl phthalate esters (DMPE) under sulfate-reducing condition.

    PubMed

    Cheung, Joseph K H; Lam, Rita K W; Shi, M Y; Gu, J-D

    2007-08-01

    Dimethyl phthalate esters (DMPE) can easily be released into the environment from plastic products. As endocrine disruptors, DMPE mimic estrogenic activities in animals and humans. The metabolites of DMPE are suspected to cause even more serious health problems. Among the common sterilization techniques adopted in the study of DMPE degradation, the average loss of the parent DMPE compounds after autoclaving was as high as 21.26%. In contrast, the loss after 0.2 microm filtration was significantly lower at 2.28%. It is suggested that filtration should be used over autoclaving for sterilizing DMPE. The environmental fate of DMPE under sulfate-reducing condition was simulated and studied in microcosm system. It was observed that dimethyl phthalate (DMP), dimethyl isophthalate (DMI) and dimethyl terephthalate (DMT) could not be mineralized over an extended period of 6 months, but with the transformation to the respective monomethyl phthalate and/or phthalic acid. The dominant species of microorganisms utilizing individual DMPE isomer as the sole carbon source were isolated and identified as facultative anaerobe Thauera sp., Xanthobacter sp. and Agrobacterium sp. for DMP, DMI and DMT, respectively. This study illustrates that the detrimental DMPE and their natural metabolites may accumulate in the sulfate-reducing environment. Accordingly, proper surveillance program should be devised to monitor both the parent compounds and degradation intermediates of DMPE in order to protect the aquatic ecosystem and human health. PMID:17462710

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

    PubMed

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

    2015-06-01

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

  8. Habitat-specific environmental conditions primarily control the microbiomes of the coral Seriatopora hystrix.

    PubMed

    Pantos, Olga; Bongaerts, Pim; Dennis, Paul G; Tyson, Gene W; Hoegh-Guldberg, Ove

    2015-09-01

    Reef-building corals form complex relationships with a range of microorganisms including bacteria, archaea, fungi and the unicellular microalgae of the genus Symbiodinium, which together form the coral holobiont. These symbionts are known to have both beneficial and deleterious effects on their coral host, but little is known about what the governing factors of these relationships are, or the interactions that exist between the different members of the holobiont and their environment. Here we used 16S ribosomal RNA gene amplicon sequencing to investigate how archaeal and bacterial communities associated with the widespread scleractinian coral Seriatopora hystrix are influenced by extrinsic (reef habitat and geographic location) and intrinsic (host genotype and Symbiodinium subclade) factors. Bacteria dominate the microbiome of S. hystrix, with members of the Alphaproteobacteria, Gammaproteobacteria and Bacteriodetes being the most predominant in all samples. The richness and evenness of these communities varied between reef habitats, but there was no significant difference between distinct coral host lineages or corals hosting distinct Symbiodinium subclades. The coral microbiomes correlated to reef habitat (depth) and geographic location, with a negative correlation between Alpha- and Gammaproteobacteria, driven by the key members of both groups (Rhodobacteraceae and Hahellaceae, respectively), which showed significant differences between location and depth. This study suggests that the control of microbial communities associated with the scleractinian coral S. hystrix is driven primarily by external environmental conditions rather than by those directly associated with the coral holobiont. PMID:25668159

  9. Toxicity of pentachlorophenol to aquatic organisms under naturally varying and controlled environmental conditions

    SciTech Connect

    Hedtke, S.F.; West, C.W.; Allen, K.N.; Norberg-King, T.J.; Mount, D.I.

    1986-06-01

    The toxicity of pentachlorophenol (PCP) was determined in the laboratory for 11 aquatic species. Tests were conducted seasonally in ambient Mississippi River water and under controlled conditions in Lake Superior water. Fifty-one acute toxicity tests were conducted, with LC50 values ranging from 85 micrograms/L for the white sucker Catastomus commersoni during the summer to greater than 7770 micrograms/L for the isopod Asellus racovitzai during the winter. The effect of PCP on growth and/or reproduction was determined for seven species. The most sensitive chronically exposed organisms were the cladoceran Ceriodaphnia reticulata and the snail Physa gyrina. The greatest variation in toxicity was due to species sensitivity. Within a given, season there was as much as a 40-fold difference in LC50 values between species. For any one species, the maximum variation in LC50 between seasons was approximately 14-fold. There were also substantial differences in acute-chronic relationships, with acute/chronic ratios ranging from greater than 37 for C. reticulata to 1 for Simocephalus vetulus. It is suggested that the composition of the aquatic community should be the most important consideration in estimating the potential environmental effects of PCP.

  10. Effect of environmental conditions on the decay of stone in archaeological site of Volubilis - Morocco

    NASA Astrophysics Data System (ADS)

    Aalil, Issam; Chaaba, Ali; Cherkaoui, Khalid; Brunetaud, Xavier; Beck, Kevin; Al-Mukhtar, Muzahim

    2015-04-01

    Volubilis is the most excavated and the best preserved archaeological site of Morocco. Located about thirty kilometres north of Meknes, it was a Mauritanian capital founded in the 3rd century B.C., and became an important outpost of the Roman Empire. Volubilis monuments are constructed with five regional lithotypes of limestone. A grey massive limestone and beige-yellowish calcarenite limestone are the two most largely used on Volubilis site, representing respectively about 30% and 60 % of the total volume of building stones. Field observations showed that the calcarenite limestone is more decayed than the massive limestone and is mainly affected by scaling, alveolization and sanding. This work aims to estimate the role of environmental conditions on the decay of the calcarenite stone through the effect of thermal stresses and freezing-thawing action. Air temperature data of Meknes station is analysed. Furthermore, mineralogical composition of the calcarenite limestone and its intrinsic properties required for stress calculation are determined. The results of this study show that the calcarenite limestone is a quite soft carbonate stone, contains about 71 % of calcite, 18 % of quartz and others accessory minerals. Besides, there is no risk of damage due to freezing-thawing processes. Nonetheless, thermal stresses may have an important role in the decay of calcarenite stones of the Volubilis site.

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

    PubMed Central

    Mantripragada, Venkata P.; Jayasuriya, Ambalangodage C.

    2014-01-01

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

  12. Variation of saponin contents and physiological status in Quillaja saponaria under different environmental conditions.

    PubMed

    Grandón, Angélica S; Espinosa, B Miguel; Ríos, Darcy L; Sánchez, O Manuel; Sáez, C Katia; Hernández, S Víctor; Becerra, A José

    2013-12-01

    Quillaja saponaria (Quillay), an evergreen tree found in Chile, is one of the main sources of saponins. Quillaja saponins have hypocholesterolaemic, anticarcinogenic, antioxidant and pesticidal properties, and are used as adjuvants for vaccines. Samples of Quillay growing at three zones in O'Higgins Region, Chile (Coastal, Central and Mountain zones) were analyzed for content of saponins and physiological status. The results revealed differences in the content of saponins depending on the zone of sample collection. The highest contents were found in samples from the Mountain zone, where the highest saponin contents were accompanied by the lowest foliar nitrogen contents, the highest antioxidant activity and the highest carotenoid contents. The results suggest a physiological and adaptive mechanism of saponins in plants to survive under unfavourable environmental conditions. The results have important implications for a theoretical basis for the design of a reasonable harvest, to avoid the cost of poor quality material, and also to provide a sustainable use and conservation of this important species. Further research on the effects of stress will improve our understanding of the saponins production and their physiological functions in plants, whereas they have generally been studied for their biological and chemical applications. PMID:24555275

  13. Environmental risk assessment of GE plants under low-exposure conditions.

    PubMed

    Roberts, Andrew; Devos, Yann; Raybould, Alan; Bigelow, Patrick; Gray, Alan

    2014-12-01

    The requirement for environmental risk assessment (ERA) of genetically engineered (GE) plants prior to large scale or commercial introduction into the environment is well established in national laws and regulations, as well as in international agreements. Since the first introductions of GE plants in commercial agriculture in the 1990s, a nearly universal paradigm has emerged for conducting these assessments based on a few guiding principles. These include the concept of case-by-case assessment, the use of comparative assessments, and a focus of the ERA on characteristics of the plant, the introduced trait, and the receiving environment as well as the intended use. In practice, however, ERAs for GE plants have frequently focused on achieving highly detailed characterizations of potential hazards at the expense of consideration of the relevant levels of exposure. This emphasis on exhaustive hazard characterization can lead to great difficulties when applied to ERA for GE plants under low-exposure conditions. This paper presents some relevant considerations for conducting an ERA for a GE plant in a low-exposure scenario in the context of the generalized ERA paradigm, building on discussions and case studies presented during a session at ISBGMO 12. PMID:24178711

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

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  15. Effects of environmental conditions on the nitrifying population dynamics in a pilot wastewater treatment plant.

    PubMed

    Lydmark, Pär; Almstrand, Robert; Samuelsson, Kristina; Mattsson, Ann; Sörensson, Fred; Lindgren, Per-Eric; Hermansson, Malte

    2007-09-01

    The effect of environmental conditions, especially ammonium concentration, on community composition and nitrification activity of nitrifying bacterial biofilms in a pilot wastewater treatment plant was examined. A decreasing ammonium gradient was created when four aerated tanks with suspended carrier material were serially fed with wastewater. Community composition was analysed using fluorescence in situ hybridization (FISH) probes as well as partial 16S rRNA and amoA gene analysis using polymerase chain reaction-denaturating gradient gel electrophoresis (PCR-DGGE) and sequencing. Fluorescence in situ hybridization probes identified at least five ammonia-oxidizing bacterial (AOB) and two nitrite-oxidizing bacterial (NOB) populations. A change in nitrifying community was detected in the tanks, indicating that ammonium was an important structuring factor. Further, we found support for different autoecology within the Nitrosomonas oligotropha lineage, as at least one population within this lineage increased in relative abundance with ammonium concentration while another population decreased. Absolute numbers of AOB and NOB growing in biofilms on the carriers were determined and the cell specific nitrification rates calculated seemed strongly correlated to ammonium concentration. Oxygen could also be limiting in the biofilms of the first tank with high ammonium concentrations. The response of the nitrifying community to increased ammonium concentrations differed between the tanks, indicating that activity correlates with community structure. PMID:17686020

  16. Environmental enrichment blocks reinstatement of ethanol-induced conditioned place preference in mice.

    PubMed

    Li, Xinjuan; Meng, Li; Huang, Keyu; Wang, Hua; Li, Dongliang

    2015-07-10

    This study aimed to explore the effect of environmental enrichment (EE) on the reinstatement of ethanol-induced conditioned place preference (CPP) in C57Bl/6J mice. To investigate the effect of training dose on the extinction and relapse of ethanol-induced CPP, doses of ethanol were applied and we found 0.8 g/kg and 1.6 g/kg training doses lead to significant CPP. In the reinstatement procedure, previously extinguished 1.6 g/kg ethanol CPP could be markedly reinstated by a priming injection of 0.8 g/kg. In contrast, priming with 0.4 g/kg of ethanol failed to reinstate the CPP induced by 0.8 g/kg. To investigate whether concomitant EE exposure could prevent the reinstatement of ethanol-induced CPP, one half of the mice were housed in standard environment (SE) and the other half in EE during the extinction and reinstatement session in the second experiment. Our study showed that reinstatement of ethanol-induced CPP was blocked by EE and the extinction rate was the same between SE and EE mice. These findings suggest that EE can block reinstatement of ethanol-induced CPP in mice, and aiding in the identification of new therapeutic strategies for alcohol addiction. PMID:26003446

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

    PubMed Central

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

    2012-01-01

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

  18. Ruggedizing infrared integrated Dewar-detector assemblies for harsh environmental conditions

    NASA Astrophysics Data System (ADS)

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

    2014-06-01

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

  19. Effect of environmental conditions on the permeability of high density polyethylene film to fumigant vapors.

    PubMed

    Papiernik, Sharon K; Yates, Scott R

    2002-04-15

    Soil fumigation in greenhouses or agricultural fields often includes tarping the soil surface with polyethylene (PE) films to contain the fumigant in the soil and reduce emissions to the atmosphere. Previous research has demonstrated that PE films are permeable to methyl bromide and other fumigant compounds. In these experiments, the effect of temperature, fumigant mixtures, condensed water, and field aging on the permeability of high-density polyethylene (HDPE) was determined. Mass transfer coefficients (h, a measure of permeability) of the fumigants methyl bromide, 1,3-dichloropropene, propargyl bromide, and chloropicrin across HDPE films were determined. In these studies, temperature and HDPE film type had the largest impact on the h of fumigant compounds across HDPE films. Other factors investigated, including fumigant mixtures, condensed water on the film, and field aging of UV-stabilized film, did not have a significant impact on h. The results of these experiments suggest that the permeability of an intact piece of an agricultural film will increase with increasing temperature but is relatively constant despite changes in other environmental conditions. PMID:11993884

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

    USGS Publications Warehouse

    MacCoy, Dorene E.

    2006-01-01

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

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

    PubMed Central

    Wang, Jian-Neng; Tang, Jaw-Luen

    2010-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

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

    PubMed

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

    2013-09-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  6. Transgene expression and Bt protein content in transgenic Bt maize (MON810) under optimal and stressful environmental conditions.

    PubMed

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

    2015-01-01

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

  7. Developmental programming: Cumulative effects of increased pre-hatching corticosterone levels and post-hatching unpredictable food availability on physiology and behaviour in adulthood?

    PubMed Central

    Zimmer, Cédric; Boogert, Neeltje J.; Spencer, Karen A.

    2013-01-01

    Prolonged exposure to stress during development can have long-term detrimental effects on health and wellbeing. However, the environmental matching hypothesis proposes that developmental stress programs physiology and behaviour in an adaptive way that can enhance fitness if early environments match those experienced later in life. Most research has focused on the harmful effects that stress during a single period in early life may exert in adulthood. In this study, we tested the potential additive and beneficial effects that stress experienced during both pre- and post-hatching development may have on adult physiology and behaviour. Japanese quail experienced different stress-related treatments across two developmental life stages: pre-hatching corticosterone (CORT) injection, post-hatching unpredictable food availability, both pre- and post-hatching treatments, or control. In adulthood, we determined quails' acute stress response, neophobia and novel environment exploration. The pre-hatching CORT treatment resulted in attenuated physiological responses to an acute stressor, increased activity levels and exploration in a novel environment. Post-hatching unpredictable food availability decreased adults' latency to feed. Furthermore, there were cumulative effects of these treatments across the two developmental stages: quail subjected to both pre- and post-hatching treatments were the most explorative and risk-taking of all treatment groups. Such responses to novel environments could enhance survival in unpredictable environments in later life. Our data also suggest that these behavioural responses may have been mediated by long-term physiological programming of the adrenocortical stress response, creating phenotypes that could exhibit fitness-enhancing behaviours in a changing environment. PMID:23891687

  8. Surface studies of dry and solid lubricants under different environmental conditions

    NASA Astrophysics Data System (ADS)

    Dudder, Gregory James

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

  9. Fat or lean: adjustment of endogenous energy stores to predictable and unpredictable changes in allostatic load

    USGS Publications Warehouse

    Schultner, Jannik; Kitaysky, Alexander S.; Welcker, Jorg; Hatch, Scott

    2013-01-01

    6. Overall, results of this study support the ‘lean and fit’ hypothesis. We conclude that increased energy stores may not necessarily reflect better environmental conditions experienced by individuals or predict their higher fitness. A major advantage of adopting a lean physique when environmental conditions allow may be the avoidance of additional energetic costs for moving a heavy body. In breeding seabirds, this advantage may be more important during chick-rearing. In the focal species, the secretion of glucocorticoids might be involved in regulation of energy stores within a life history stage but does not appear to mediate an adaptive shift in energy stores between the incubating and chick-rearing stages of reproduction.

  10. Effectiveness Analysis of Filters Used with Radon Detectors under Extreme Environmental Conditions for Long-term Exposures

    NASA Astrophysics Data System (ADS)

    Moreno, V.; Font, Ll.; Baixeras, C.; Garcia-Orellana, J.; Bach, J.; Grossi, C.; Vargas, A.

    Active and passive radon detectors have been exposed with different filter configurations at the INTE radon chamber controlled conditions. Correction factors and delay times of the radon diffusion through each filter have been determined. Additionally, some of the studied filter/detector configurations have been used to measure radon in several workplaces and outdoor sites under real extreme environmental conditions. Analysis of these detectors showed partial degradation, so used filters seem not to be protective enough for long-term exposures.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  12. Simulating Arctic mixed-phase clouds: Sensitivity to environmental conditions and cloud microphysical processes

    NASA Astrophysics Data System (ADS)

    Sednev, I.; Menon, S.

    2005-12-01

    The importance of Arctic mixed-phase clouds on radiation and the Arctic climate are evaluated using the NASA GISS single column model (SCM) and ARM observations. The observations were conducted during the DOE ARM campaign (MPACE) in October 2004 at the North Slope of Alaska. Of interest is the ability of the SCM cloud microphysics scheme to reproduce the development and persistence of mixed-phase stratiform clouds observed during MPACE. Improvements to the GISS SCM include the redesign of numerical algorithms used in the turbulence scheme and reformulation of the numerical surface boundary conditions to better represent the environmental conditions in which these cloud systems persist. The modified GISS SCM simulates the observed temperature and humidity fields more realistically during the two week observational period (October 5 to 20) compared to the older version, within the uncertainties of the forcing data used to initialise/drive the model. Although we simulate the entire two week episode, we mainly focus on two periods: October 5th and 6th, where multiple level clouds were observed; and Oct 8-12, where a single level stratus was observed. Both these cases had mixed-phase clouds. Our simulations show that despite its simplicity, the SCM cloud scheme is able to reproduce the qualitatively typical behavior of mixed-phase stratiform Arctic clouds for both cases. However, some modifications are required to improve the description of microphysical processes such as the ice nucleation mechanisms and processes related to the formation of precipitation. Sensitivity tests are conducted to understand the impact of the addition of various ice nucleation mechanisms (contact, immersion, condensational, etc.) to the cloud field and radiative fluxes. Observations of ice/water drop size distributions, cloud phase, etc., allow us to constrain model microphysical modifications more realistically. Additional observations of the temporal behaviour of properties such as cloud cover, liquid/ice water paths and radiative fluxes simulated by the model will also be compared with observations. This will help in evaluating the importance of the environment and the representation of cloud microphysics in simulating the Arctic mixed-phase cloud structure and lifetime, and finally to evaluate the impact of mixed-phase clouds on radiation.

  13. Incidence of exercise-induced asthma in adolescent athletes under different training and environmental conditions.

    PubMed

    Sidiropoulou, Maria P; Kokaridas, Dimitrios G; Giagazoglou, Paraskevi F; Karadonas, Michalis I; Fotiadou, Eleni G

    2012-06-01

    The aim of this study was to establish if there were differences in the incidence of exercise-induced bronchospasm between athletes in different sports, which take place under different environmental conditions such as open places, closed courses, and swimming pools with similar exercise intensity (football, basketball, water polo) using the free running test. The study included 90 adolescents (3 groups of 30) aged 14-18 years recruited from academies in northern Greece. All the participants were initially subjected to (a) a clinical examination and cardiorespiratory assessment by a physician and (b) free running test of a 6-minute duration and measurement with a microspirometer of the forced expiratory volume in 1 second (FEV?). Only the participants who had measured a decrease in FEV? ? 10% were reevaluated with the microspirometer during a training session. The examination of all the participants during the free running test showed that 22 athletes, that is, 9, 8, and 5 of football, basketball, and water polo athletes, respectively, demonstrated an FEV? ? 10 drop. Reevaluation of the 22 participants during training showed that 5 out 9 (55%) football athletes, 4 out of 8 basketball athletes (50%), and none of the 5 athletes of the water polo team displayed a drop of FEV? ? 10%. Despite the absence of any significant statistical differences between the 3 groups, the analysis of variances did show a trend of a lower incidence of EIA in the water polo athletes. It was found that a football or basketball game can induce EIA in young athletes but to a lesser degree than the free running test can induce. The water polo can be a safer sport even for participants with a medical history of asthma or allergies. PMID:21912293

  14. Conditional switching: a new variety of regression with many potential environmental applications.

    PubMed Central

    Tarter, M E; Lock, M D; Ray, R M

    1995-01-01

    We introduce a new form of regression that has many applications to environmental studies. For a sequence composed of key variates with prototypic value chi, this form differs from the estimation of a location parameter-based curve, mu(chi), a scale parameter-based curve, sigma(chi), or other currently used types of regression. Instead of estimating a curve location, scale, or alpha-quantile parameter, it assumes that there are two or more population subgroups; for example, consisting of unsensitized and sensitized individuals, respectively. Although within each subgroup the relationships mu(chi) or sigma(chi) may or may not be horizontal, these relationships are not deemed to be of primary importance. Instead, the mixing parameter P that indexes the proportions of the two subgroups is treated as being related to the key variate value chi. In the sense that its goal is the estimation of a proportion, the new procedure resembles logit regression. But, in terms of the continuous spectrum of values attained by the response variate, the means used to attain its goal are dissimilar from those of logit regression. Specifically, group membership is not known directly but is determined from a proxy continuous variate whose values overlap between groups. Examples are given with simulated and natural data where this new form of regression is applied. We believe that conditional switching regression is a particularly valuable research tool when chemical level chi of an induced asthma attack or birthweight chi measured in a study of the biomarker cotinine's effect on pregnancy outcomes determines whether an attack or a negative outcome occurs.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure C-1. Figure C-1. Figure C-1. Figure C-1. Figure C-1. Figure C-1. Figure D-1. Figure D-2. PMID:7588488

  15. Concrete Durability in Harsh Environmental Conditions Exposed to Freeze Thaw Cycles

    NASA Astrophysics Data System (ADS)

    Hamze, Youssef

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

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

    PubMed Central

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

    2012-01-01

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

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

    SciTech Connect

    1980-12-12

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

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

    PubMed Central

    Zimmermann, Boris; Kohler, Achim

    2014-01-01

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

  19. Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  20. Biodegradation of chemicals in a standardized test and in environmental conditions.

    PubMed

    Ahtiainen, Jukka; Aalto, Miia; Pessala, Piia

    2003-05-01

    The estimation of biodegradation rates is an important source of uncertainty in chemical risk assessment. The existing OECD tests for ready biodegradability have been developed to devise screening methods to determine whether a chemical is potentially easily biodegradable, rather than to predict the actual rate, of biodegradation in the environment. However, risk assessment needs degradation rates. In practice these rates are often estimated (default values) from ready biodegradability tests. These tests have many compromising arbitrary features compared to the situation in the real environment. One important difference is the concentration of the chemical. In wastewater treatment or in the environment many chemicals are present at ng l(-1) to microg l(-1) levels whereas in the tests the concentrations exceed 10-400 mg carbon per litre. These different concentrations of the chemical will lead to different growth kinetics and hence different biodegradation rates. At high concentrations the chemical, if it is degradable, can serve as a primary substrate and competent microorganisms will grow exponentially, resulting in a sigmoid biodegradation curve. At low environmental concentrations the chemical does not serve as a primary substrate, and therefore does not support significant growth of the degraders, and the substrate has a linear biodegradation rate. In this study the biodegradation rates of two reference chemicals, aniline and 4-chloroaniline, were compared in a standard method and in more realistic conditions at low concentrations, using 14C-labelled substances and different sources of inocula. Biomass evolution during the tests was monitored by adenosine triphosphate measurement and also on the basis of the residual 14C-activity in the particulate matter. The results partly support the thesis that low concentrations lead to different biodegradation kinetics compared to the concentrations used in the standard tests. Furthermore the biodegradation rates of the chemicals studied, particularly of 4-chloroaniline, in Finnish natural waters appeared to be lower than those reported in some other countries. PMID:12615106

  1. Degradation kinetics of a potent antifouling agent, butenolide, under various environmental conditions.

    PubMed

    Chen, Lianguo; Xu, Ying; Wang, Wenxiong; Qian, Pei-Yuan

    2015-01-01

    Here, we investigated the degradation kinetics of butenolide, a promising antifouling compound, under various environmental conditions. The active ingredient of the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), was used as positive control. The results showed that the degradation rate increased with increasing temperature. Half-lives of butenolide at 4 °C, 25 °C and 40 °C were>64 d, 30.5 d and 3.9 d, respectively. Similar half-lives were recorded for DCOIT: >64 d at 4 °C, 27.9 d at 25 °C and 4.5d at 40 °C. Exposure to sunlight accelerated the degradation of both butenolide and DCOIT. The photolysis half-lives of butenolide and DCOIT were 5.7 d and 6.8 d, respectively, compared with 9.7 d and 14.4 d for the dark control. Biodegradation led to the fastest rate of butenolide removal from natural seawater, with a half-life of 0.5 d, while no obvious degradation was observed for DCOIT after incubation for 4 d. The biodegradative ability of natural seawater for butenolide was attributed mainly to marine bacteria. During the degradation of butenolide and DCOIT, a gradual decrease in antifouling activity was observed, as indicated by the increased settlement percentage of cypris larvae from barnacle Balanus amphitrite. Besides, increased cell growth of marine diatom Skeletonema costatum demonstrated that the toxicity of seawater decreased gradually without generation of more toxic by-products. Overall, rapid degradation of butenolide in natural seawater supported its claim as a promising candidate for commercial antifouling industry. PMID:25460745

  2. Ultrastructure of potato tubers formed in microgravity under controlled environmental conditions.

    PubMed

    Cook, Martha E; Croxdale, Judith G

    2003-09-01

    Previous spaceflight reports attribute changes in plant ultrastructure to microgravity, but it was thought that the changes might result from growth in uncontrolled environments during spaceflight. To test this possibility, potato explants were examined (a leaf, axillary bud, and small stem segment) grown in the ASTROCULTURETM plant growth unit, which provided a controlled environment. During the 16 d flight of space shuttle Columbia (STS-73), the axillary bud of each explant developed into a mature tuber. Upon return to Earth, tuber slices were examined by transmission electron microscopy. Results showed that the cell ultrastructure of flight-grown tubers could not be distinguished from that of tuber cells grown in the same growth unit on the ground. No differences were observed in cellular features such as protein crystals, plastids with starch grains, mitochondria, rough ER, or plasmodesmata. Cell wall structure, including underlying microtubules, was typical of ground-grown plants. Because cell walls of tubers formed in space were not required to provide support against the force due to gravity, it was hypothesized that these walls might exhibit differences in wall components as compared with walls formed in Earth-grown tubers. Wall components were immunolocalized at the TEM level using monoclonal antibodies JIM 5 and JIM 7, which recognize epitopes of pectins, molecules thought to contribute to wall rigidity and cell adhesion. No difference in presence, abundance or distribution of these pectin epitopes was seen between space- and Earth-grown tubers. This evidence indicates that for the parameters studied, microgravity does not affect the cellular structure of plants grown under controlled environmental conditions. PMID:12867548

  3. Amoxicillin-degradation products formed under controlled environmental conditions: identification and determination in the aquatic environment.

    PubMed

    Gozlan, Igal; Rotstein, Adi; Avisar, Dror

    2013-05-01

    Amoxicillin (AMX) is a widely used penicillin-type antibiotic whose presence in the environment has been widely investigated, despite its rapid hydrolysis to various degradation products (DPs). In this work, the formation of AMX DPs was studied in various aqueous solutions containing 100?gmL(-1) AMX. Three phosphate buffer solutions, at pH 5, pH 7 and pH 8, and a fourth buffer solution at pH 7 with the addition of the bivalent ions Mg(2+)and Ca(2) as chelating agents, were examined under controlled environmental conditions. In addition, two solutions from natural sources were examined secondary effluents and tap water. The obtained DPs were identified by their MS/MS, UV and NMR spectra (obtained from pure compounds isolated by preparative HPLC) as: AMX penicilloic acid (ADP1/2), AMX penilloic acid (ADP4/5) and phenol hydroxypyrazine (ADP6). Two additional detected DPs AMX 2',5'-diketopiperazine (ADP8/9), and AMX-S-oxide (ADP3) were reported and discussed in our previous publications. These DPs were then detected in secondary effluent and groundwater from a well located beneath agricultural fields continuously irrigated with secondary effluent. Concentrations in the secondary effluent were: ADP1/2, several micrograms per liter; ADP4/5, 0.15?gL(-1), and ADP8/9, 0.5?gL(-1). ADP6 were detected but not quantified. In the groundwater, only ADP8/9 was detected, at a concentration of 0.03?gL(-1). The detection and quantification of DPs of other investigated drugs is recommended as an integral part of any study, method or technique dealing with pharmaceutical residues in aquatic environments. PMID:23466086

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

    USGS Publications Warehouse

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

    2005-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  8. 75 FR 47881 - Fifty-Sixth Meeting, RTCA Special Committee 135: Environmental Conditions and Test Procedures for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-09

    ... and Test Procedures for Airborne Equipment AGENCY: Federal Aviation Administration (FAA), Department... Test Procedures for Airborne Equipment meeting. SUMMARY: The FAA is issuing this notice to advise the.../SC135-678). Review/Approval Revised DO-160F--Environmental Conditions and Test Procedures for...

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

    ERIC Educational Resources Information Center

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

    2013-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    PubMed Central

    2014-01-01

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

  12. Temporal unpredictability of a stimulus sequence and the processing of neutral and emotional stimuli.

    PubMed

    Koppe, G; Heidel, A; Sammer, G; Bohus, M; Gallhofer, B; Kirsch, P; Lis, S

    2015-10-15

    Most experimental settings in cognitive neuroscience present a temporally structured stimulus sequence, i.e., stimuli may occur at either constant and predictable or variable and less predictable inter-stimulus intervals (ISIs). This experimental feature has been shown to affect behavior and activation of various cerebral structures such as the parietal cortex and the amygdala. Studies employing explicit or implicit cues to manipulate predictability of events have shown that unpredictability particularly accentuates the response to events of negative valence. The present study investigates whether the effects of unpredictability are similarly affected by the emotional content of stimuli when unpredictability is induced simply by the temporal structure of a stimulus sequence, i.e., by variable as compared to constant ISIs. In an fMRI study, we applied three choice-reaction-time tasks with stimuli of different social-emotional content. Subjects (N=30) were asked to identify the gender in angry and happy faces, or the shape of geometric figures. Tasks were performed with variable and constant ISIs. During the identification of shapes, variable ISIs increased activation in widespread areas comprising the amygdala and fronto-parietal regions. Conversely, variable ISIs during gender identification resulted in a decrease of activation in a small region near the intraparietal sulcus. Our findings reveal that variability in the temporal stimulus structure of an experimental setting affects cerebral activation depending on task demands. They suggest that the processing of emotional stimuli of different valence is not much affected by the decision of employing a constant or a variable temporal stimulus structure, at least in the context of implicit emotion processing tasks. In contrast, temporal structure diversely affects the processing of neutral non-social compared to emotional stimuli, emphasizing the relevance of considering this experimental feature in studies which aim at differentiating social-emotional from cognitive processing in general, and more particularly, aim at identifying circumscribed alterations of social cognition in mental disorders. PMID:26143208

  13. Experimental study of inequality and unpredictability in an artificial cultural market.

    PubMed

    Salganik, Matthew J; Dodds, Peter Sheridan; Watts, Duncan J

    2006-02-10

    Hit songs, books, and movies are many times more successful than average, suggesting that "the best" alternatives are qualitatively different from "the rest"; yet experts routinely fail to predict which products will succeed. We investigated this paradox experimentally, by creating an artificial "music market" in which 14,341 participants downloaded previously unknown songs either with or without knowledge of previous participants' choices. Increasing the strength of social influence increased both inequality and unpredictability of success. Success was also only partly determined by quality: The best songs rarely did poorly, and the worst rarely did well, but any other result was possible. PMID:16469928

  14. Effect of potential catastrophic morality and other unpredictable events on optimal forest rotation policy

    SciTech Connect

    Routledge, R.D.

    1980-09-01

    Because standard methods for computing the optimal rotation age of a forest stand must assume complete knowledge of the stand value at any future time, a forest manager must treat his estimates of future values as if they were completely accurate. Minor, unpredictable fluctuations from year to year are assumed to somehow cancel each other out. Potential catastrophes, such as forest fires or insect plagues, are customarily ignored. An alternate method for dealing with uncertainty is presented here. This method can incorporate estimates of the likelihood of catastrophes. It is shown that catastrophic moraltiy has a potentially significant effect on the optimal rotation strategy, average profits, and land valuation.

  15. Fatigue Crack Growth Analysis Under Spectrum Loading in Various Environmental Conditions

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

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

    EPA Science Inventory

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

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

    PubMed Central

    Watson, Hannah; Bolton, Mark; Monaghan, Pat

    2015-01-01

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

  18. Household environmental conditions are associated with enteropathy and impaired growth in rural Bangladesh.

    PubMed

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

    2013-07-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

    Crespi, Erica J; Warne, Robin W

    2013-12-01

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

  1. Short-term synaptic plasticity in the deterministic Tsodyks-Markram model leads to unpredictable network dynamics.

    PubMed

    Cortes, Jesus M; Desroches, Mathieu; Rodrigues, Serafim; Veltz, Romain; Muñoz, Miguel A; Sejnowski, Terrence J

    2013-10-01

    Short-term synaptic plasticity strongly affects the neural dynamics of cortical networks. The Tsodyks and Markram (TM) model for short-term synaptic plasticity accurately accounts for a wide range of physiological responses at different types of cortical synapses. Here, we report a route to chaotic behavior via a Shilnikov homoclinic bifurcation that dynamically organizes some of the responses in the TM model. In particular, the presence of such a homoclinic bifurcation strongly affects the shape of the trajectories in the phase space and induces highly irregular transient dynamics; indeed, in the vicinity of the Shilnikov homoclinic bifurcation, the number of population spikes and their precise timing are unpredictable and highly sensitive to the initial conditions. Such an irregular deterministic dynamics has its counterpart in stochastic/network versions of the TM model: The existence of the Shilnikov homoclinic bifurcation generates complex and irregular spiking patterns and--acting as a sort of springboard--facilitates transitions between the down-state and unstable periodic orbits. The interplay between the (deterministic) homoclinic bifurcation and stochastic effects may give rise to some of the complex dynamics observed in neural systems. PMID:24062464

  2. Testosterone has antidepressant-like efficacy and facilitates imipramine-induced neuroplasticity in male rats exposed to chronic unpredictable stress.

    PubMed

    Wainwright, Steven R; Workman, Joanna L; Tehrani, Amir; Hamson, Dwayne K; Chow, Carmen; Lieblich, Stephanie E; Galea, Liisa A M

    2016-03-01

    Hypogonadal men are more likely to develop depression, while testosterone supplementation shows antidepressant-like effects in hypogonadal men and facilitates antidepressant efficacy. Depression is associated with hypothalamic-pituitary-adrenal (HPA) axis hyperactivity and testosterone exerts suppressive effects on the HPA axis. The hippocampus also plays a role in the feedback regulation of the HPA axis, and depressed patients show reduced hippocampal neuroplasticity. We assessed the antidepressant-like effects of testosterone with, or without, imipramine on behavioral and neural endophenotypes of depression in a chronic unpredictable stress (CUS) model of depression. A 21-day CUS protocol was used on gonadectomized male Sprague-Dawley rats treated with vehicle, 1mg of testosterone propionate, 10mg/kg of imipramine, or testosterone and imipramine in tandem. Testosterone treatment reduced novelty-induced hypophagia following CUS exposure, but not under non-stress conditions, representing state-dependent effects. Further, testosterone increased the latency to immobility in the forced swim test (FST), reduced basal corticosterone, and reduced adrenal mass in CUS-exposed rats. Testosterone also facilitated the effects of imipramine by reducing the latency to immobility in the FST and increasing sucrose preference. Testosterone treatment had no significant effect on neurogenesis, though the combination of testosterone and imipramine increased PSA-NCAM expression in the ventral dentate gyrus. These findings demonstrate the antidepressant- and anxiolytic-like effects of testosterone within a CUS model of depression, and provide insight into the mechanism of action, which appears to be independent of enhanced hippocampal neurogenesis. PMID:26774465

  3. Dormant stages of crustaceans as a mechanism of propagation in the extreme and unpredictable environment in the Crimean hypersaline lakes

    NASA Astrophysics Data System (ADS)

    Shadrin, Nickolai V.; Anufriieva, Elena V.; Amat, Francisco; Eremin, Oleg Yu.

    2015-11-01

    A pool of dormant stages of planktonic organisms in saline lakes is a substantial component in the plankton communities; we need to take it into account to understand plankton dynamics. Hypersaline water bodies in Crimea, the largest peninsula in the Black Sea, constitute a very characteristic and peculiar habitat type in the region. We examined the presence of crustacean resting stages in sediments of dried up sites of the Crimean hypersaline lakes. Sediment samples were taken in 9 different lakes. Experiments performed on the hatching of these resting stages showed the presence of Moina salina (Cladocera), parthenogenetic Artemia and Artemia urmiana (Anostraca), Eucypris mareotica ( inflata) (Ostracoda), and Cletocamptus retrogressus (Harpacticoida). Comparing the experimental results obtained with clean dried brine shrimp cysts and those kept in sediment samples, it was noted that clean cysts hatched much faster than those from sediments did. Some components in bottom sediments slow down and desynchronize hatching from resting eggs in different groups of crustaceans. The sediments of different lakes inhibited the nauplii output from Artemia and ostracod resting eggs to different degrees. More data are needed before we can discuss the reasons of this inhibition. The nonsynchronous output of active stages from the bottom resting ones may be an adaptation that allows crustacean species to exist in extreme and unpredictably changing environments, avoiding the risk that all may emerge at once under unsuitable conditions.

  4. Short-term synaptic plasticity in the deterministic Tsodyks–Markram model leads to unpredictable network dynamics

    PubMed Central

    Cortes, Jesus M.; Desroches, Mathieu; Rodrigues, Serafim; Veltz, Romain; Muñoz, Miguel A.; Sejnowski, Terrence J.

    2013-01-01

    Short-term synaptic plasticity strongly affects the neural dynamics of cortical networks. The Tsodyks and Markram (TM) model for short-term synaptic plasticity accurately accounts for a wide range of physiological responses at different types of cortical synapses. Here, we report a route to chaotic behavior via a Shilnikov homoclinic bifurcation that dynamically organizes some of the responses in the TM model. In particular, the presence of such a homoclinic bifurcation strongly affects the shape of the trajectories in the phase space and induces highly irregular transient dynamics; indeed, in the vicinity of the Shilnikov homoclinic bifurcation, the number of population spikes and their precise timing are unpredictable and highly sensitive to the initial conditions. Such an irregular deterministic dynamics has its counterpart in stochastic/network versions of the TM model: The existence of the Shilnikov homoclinic bifurcation generates complex and irregular spiking patterns and—acting as a sort of springboard—facilitates transitions between the down-state and unstable periodic orbits. The interplay between the (deterministic) homoclinic bifurcation and stochastic effects may give rise to some of the complex dynamics observed in neural systems. PMID:24062464

  5. Quality of life in spite of an unpredictable future: the next of kin of patients with multiple sclerosis.

    PubMed

    Liedström, Elisabeth; Isaksson, Ann-Kristin; Ahlström, Gerd

    2010-12-01

    The aim of the study was to describe the quality of life of the next of kin of patients diagnosed as having multiple sclerosis (MS). Forty-four next of kin were interviewed and thereafter answered the Subjective Quality of Life questionnaire. The next of kin's quality of life emerged as good in terms of both external conditions and interpersonal relationships in both the interviews and the Subjective Quality of Life. In the interviews, most of the next of kin indicated a trusting and secure relationship with the cohabiting partner, but others described a strained situation with an unsatisfactory married/cohabiting life. There was worry about a worsening of the relationship in the future. In addition, the next of kin spoke of a decrease in freedom, self-actualization, and security, also of a more negative general mood and negative emotional experiences. The results of the questionnaire showed that a sense of engagement in life, having energy, self-actualization, self-assuredness, self-acceptance, security, and general mood were significantly correlated with quality of life as a whole. The study confirms that MS is a disease affecting the whole family, and the next of kin were living in uncertainty, facing an unpredictable future. The nurses could start family support groups and help the next of kin to look after their own health, giving advice on health-promoting behavior to make it possible for the person with MS to live at home even if the illness becomes worse. PMID:21207771

  6. Chronic unpredictable stress regulates visceral adipocyte‐mediated glucose metabolism and inflammatory circuits in male rats

    PubMed Central

    Karagiannides, Iordanes; Golovatscka, Viktoriya; Bakirtzi, Kyriaki; Sideri, Aristea; Salas, Martha; Stavrakis, Dimitris; Polytarchou, Christos; Iliopoulos, Dimitrios; Pothoulakis, Charalabos; Bradesi, Sylvie

    2014-01-01

    Abstract Chronic psychological stress is a prominent risk factor involved in the pathogenesis of many complex diseases, including major depression, obesity, and type II diabetes. Visceral adipose tissue is a key endocrine organ involved in the regulation of insulin action and an important component in the development of insulin resistance. Here, we examined for the first time the changes on visceral adipose tissue physiology and on adipocyte‐associated insulin sensitivity and function after chronic unpredictable stress in rats. Male rats were subjected to chronic unpredictable stress for 35 days. Total body and visceral fat was measured. Cytokines and activated intracellular kinase levels were determined using high‐throughput multiplex assays. Adipocyte function was assessed via tritiated glucose uptake assay. Stressed rats showed no weight gain, and their fat/lean mass ratio increased dramatically compared to control animals. Stressed rats had significantly higher mesenteric fat content and epididymal fat pad weight and demonstrated reduced serum glucose clearing capacity following glucose challenge. Alterations in fat depot size were mainly due to changes in adipocyte numbers and not size. High‐throughput molecular screening in adipocytes isolated from stressed rats revealed activation of intracellular inflammatory, glucose metabolism, and MAPK networks compared to controls, as well as significantly reduced glucose uptake capacity in response to insulin stimulation. Our study identifies the adipocyte as a key regulator of the effects of chronic stress on insulin resistance, and glucose metabolism, with important ramifications in the pathophysiology of several stress‐related disease states. PMID:24819750

  7. Unpredicted Pitch Modulates Beta Oscillatory Power during Rhythmic Entrainment to a Tone Sequence

    PubMed Central

    Chang, Andrew; Bosnyak, Dan J.; Trainor, Laurel J.

    2016-01-01

    Extracting temporal regularities in external stimuli in order to predict upcoming events is an essential aspect of perception. Fluctuations in induced power of beta band (15–25 Hz) oscillations in auditory cortex are involved in predictive timing during rhythmic entrainment, but whether such fluctuations are affected by prediction in the spectral (frequency/pitch) domain remains unclear. We tested whether unpredicted (i.e., unexpected) pitches in a rhythmic tone sequence modulate beta band activity by recording EEG while participants passively listened to isochronous auditory oddball sequences with occasional unpredicted deviant pitches at two different presentation rates. The results showed that the power in low-beta (15–20 Hz) was larger around 200–300 ms following deviant tones compared to standard tones, and this effect was larger when the deviant tones were less predicted. Our results suggest that the induced beta power activities in auditory cortex are consistent with a role in sensory prediction of both “when” (timing) upcoming sounds will occur as well as the prediction precision error of “what” (spectral content in this case). We suggest, further, that both timing and content predictions may co-modulate beta oscillations via attention. These findings extend earlier work on neural oscillations by investigating the functional significance of beta oscillations for sensory prediction. The findings help elucidate the functional significance of beta oscillations in perception. PMID:27014138

  8. Unpredicted Pitch Modulates Beta Oscillatory Power during Rhythmic Entrainment to a Tone Sequence.

    PubMed

    Chang, Andrew; Bosnyak, Dan J; Trainor, Laurel J

    2016-01-01

    Extracting temporal regularities in external stimuli in order to predict upcoming events is an essential aspect of perception. Fluctuations in induced power of beta band (15-25 Hz) oscillations in auditory cortex are involved in predictive timing during rhythmic entrainment, but whether such fluctuations are affected by prediction in the spectral (frequency/pitch) domain remains unclear. We tested whether unpredicted (i.e., unexpected) pitches in a rhythmic tone sequence modulate beta band activity by recording EEG while participants passively listened to isochronous auditory oddball sequences with occasional unpredicted deviant pitches at two different presentation rates. The results showed that the power in low-beta (15-20 Hz) was larger around 200-300 ms following deviant tones compared to standard tones, and this effect was larger when the deviant tones were less predicted. Our results suggest that the induced beta power activities in auditory cortex are consistent with a role in sensory prediction of both "when" (timing) upcoming sounds will occur as well as the prediction precision error of "what" (spectral content in this case). We suggest, further, that both timing and content predictions may co-modulate beta oscillations via attention. These findings extend earlier work on neural oscillations by investigating the functional significance of beta oscillations for sensory prediction. The findings help elucidate the functional significance of beta oscillations in perception. PMID:27014138

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

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

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

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

    PubMed Central

    Dillehay, Tom D.; Kolata, Alan L.

    2004-01-01

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

  11. The impact of an unpredictable context and intolerance of uncertainty on the electrocortical response to monetary gains and losses.

    PubMed

    Nelson, Brady D; Kessel, Ellen M; Jackson, Felicia; Hajcak, Greg

    2016-02-01

    There is growing evidence that unpredictability and uncertainty can alter reward system functioning. The present study examined the impact of (1) a task-irrelevant unpredictable relative to predictable context and (2) individual differences in intolerance of uncertainty (IU) on the reward-related positivity (RewP), an event-related potential (ERP) response to monetary gains relative to losses. Specifically, 64 participants listened to predictable and unpredictable tone sequences while electroencephalography was recorded during a monetary gambling task. Participants also completed the Intolerance of Uncertainty Scale, which measures both cognitive distress (prospective IU) and behavioral inhibition (inhibitory IU) elicited by uncertainty, in addition to the Depression Anxiety Stress Scale-21 and Penn State Worry Questionnaire. Results indicated that the RewP was reduced during the unpredictable relative to the predictable context. Greater self-reported anxiety elicited by the unpredictable context was associated with a decreased RewP, and a decreased RewP was associated with poorer lose-shift behavioral adjustment. Furthermore, the RewP mediated the relationship between self-reported anxiety elicited by the unpredictable context and lose-shift behavioral adjustment. The IU subscales demonstrated the opposite relationship with the RewP across both contexts-inhibitory IU was associated with an attenuated RewP and prospective IU was associated with an enhanced RewP. In contrast, anxiety, depression, stress, and worry symptomatology were not associated with the RewP. This is the first study to demonstrate that an unpredictable context and individual differences in the degree to which people cannot tolerate uncertainty impact an ERP measure of reward system functioning. PMID:26438205

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

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

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

    PubMed

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

    2015-01-01

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

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

    DOE PAGESBeta

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

    2015-03-02

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

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

    SciTech Connect

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

    2015-03-02

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

  16. Field lysimeters for the study of fate and transport of explosive chemicals in soils under variable environmental conditions

    NASA Astrophysics Data System (ADS)

    Molina, Gloria M.; Padilla, Ingrid; Pando, Miguel; Pérez, Diego D.

    2006-05-01

    Landmines and other buried explosive devices pose in an immense threat in many places of the world, requiring large efforts on detection and neutralization of these objects. Many of the available detection techniques require the presence of chemicals near the soil-atmospheric surface. The presence of explosive related chemicals (ERCs) near this surface and their relation to the location of landmines, however, depends on the source characteristics and on fate and transport processes that affect their movement in soils. Fate and transport processes of ERC is soils may be interrelated with each other and are influenced by chemical characteristics and interrelated soil and environmental factors. Accurate detection of ERCs near the soil surface must, therefore, take into the variability of ERC concentration distributions near the soil surface as affected by fate and transport processes controlled interrelated environmental factors. To effectively predict the concentration distributions of ERCs in soils and near soil surfaces, it is necessary to have good understanding of parameters values that control these processes. To address this need, field lysimeters have been designed and developed at the University of Puerto Rico, Mayaguez .This paper presents the design of two field lysimeter used to study the fate and transport behavior of ERC in the field subjected to varying uncontrolled subtropical environmental conditions in two different soils. Both lysimeters incorporate pressure and concentration sampling ports, thermocouples, and a drainage system. Hydrus-2D was used to simulate soil moisture and drainage in the lysimeter for average environmental conditions in the study for the two soils used. The field lysimeters allow collection and monitoring of spatial and temporal ERC concentrations under variable, uncontrolled environmental conditions.

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

    PubMed Central

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

    2015-01-01

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

  18. Environmental Conditions and the Occurrence of Exertional Heat Illnesses and Exertional Heat Stroke at the Falmouth Road Race

    PubMed Central

    DeMartini, Julie K.; Casa, Douglas J.; Belval, Luke N.; Crago, Arthur; Davis, Rob J.; Jardine, John J.; Stearns, Rebecca L.

    2014-01-01

    Context: The Falmouth Road Race is unique because of the environmental conditions and relatively short distance, which allow runners to maintain a high intensity for the duration of the event. Therefore, the occurrence of exertional heat illnesses (EHIs), especially exertional heat stroke (EHS), is 10 times higher than in other races. Objective: To summarize the occurrence and relationship of EHI and environmental conditions at the Falmouth Road Race. Design: Descriptive epidemiologic study. Setting: An 11.3-km (7-mile) road race in Falmouth, Massachusetts. Patients or Other Participants: Runners who sustained an EHI while participating in the Falmouth Road Race. Main Outcome Measure(s): We obtained 18 years of medical records and environmental conditions from the Falmouth Road Race and documented the incidence of EHI, specifically EHS, as related to ambient temperature (Tamb), relative humidity, and heat index (HI). Results: Average Tamb, relative humidity, and HI were 23.3 ± 2.5°C, 70 ± 16%, and 24 ± 3.5°C, respectively. Of the 393 total EHI cases observed, EHS accounted for 274 (70%). An average of 15.2 ± 13.0 EHS cases occurred each year; the incidence was 2.13 ± 1.62 cases per 1000 runners. Regression analysis revealed a relationship between the occurrence of both EHI and EHS and Tamb (R2 = 0.71, P = .001, and R2 = 0.65, P = .001, respectively) and HI (R2 = 0.76, P < .001, and R2 = 0.74, P < .001, respectively). Occurrences of EHS (24.2 ± 15.5 cases versus 9.3 ± 4.3 cases) and EHI (32.3 ± 16.3 versus 13.0 ± 4.9 cases) were higher when Tamb and HI were high compared with when Tamb and HI were low. Conclusions: Because of the environmental conditions and race duration, the Falmouth Road Race provides a unique setting for a high incidence of EHS. A clear relationship exists between environmental stress, especially as measured by Tamb and HI, and the occurrence of EHS or other EHI. Proper prevention and treatment strategies should be used during periods of high environmental temperatures as the likelihood of runners experiencing EHS is exacerbated in these harsh conditions. PMID:24972041

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

    USGS Publications Warehouse

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

    2011-01-01

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

  20. Temporal variation in environmental conditions and the structure of fish assemblages around an offshore oil platform in the North Sea.

    PubMed

    Fujii, Toyonobu

    2015-07-01

    This study reports temporal variations in the environmental conditions and the structure of fish assemblages observed in the vicinity of an offshore oil platform and the surrounding seafloor in the North Sea. Multi-seasonal sampling was conducted at a typical large steel jacketed facility, using mid-water fish traps at three different depths (i.e., 10, 50 & 100 m). Commercially important gadoids such as saithe Pollachius virens, haddock Melanogrammus aeglefinus and cod Gadus morhua were the most abundant species, however, the species composition and the relative abundances of the species varied with depth, season and between years. Comparisons with a large-scale bottom trawl survey data suggested highly dynamic and species-specific interactions between fish movements, changing environmental conditions and the physical presence of an offshore platform. Given the number of platforms currently installed across the North Sea, there is a need to identify biological mechanisms behind such dynamic interactions. PMID:25965149

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  2. Sustainability and environmental assessment of fertigation in an intensive olive grove under Mediterranean conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Over application of water and nitrogen is a major concern for intensive olive groves in South of Portugal. In this study, field experimental measurements were integrated with a system model, Root Zone Water Quality Model (RZWQM) to assess the sustainability and environmental impact of fertigation in...

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

    EPA Science Inventory

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

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

    EPA Science Inventory

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

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

    PubMed

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

    2013-05-01

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

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

    PubMed Central

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

    2013-01-01

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

  9. Assessment of the risk of failure of high voltage substations due to environmental conditions and pollution on insulators.

    PubMed

    Castillo Sierra, Rafael; Oviedo-Trespalacios, Oscar; Candelo, John E; Soto, Jose D

    2015-07-01

    Pollution on electrical insulators is one of the greatest causes of failure of substations subjected to high levels of salinity and environmental pollution. Considering leakage current as the main indicator of pollution on insulators, this paper focuses on establishing the effect of the environmental conditions on the risk of failure due to pollution on insulators and determining the significant change in the magnitude of the pollution on the insulators during dry and humid periods. Hierarchical segmentation analysis was used to establish the effect of environmental conditions on the risk of failure due to pollution on insulators. The Kruskal-Wallis test was utilized to determine the significant changes in the magnitude of the pollution due to climate periods. An important result was the discovery that leakage current was more common on insulators during dry periods than humid ones. There was also a higher risk of failure due to pollution during dry periods. During the humid period, various temperatures and wind directions produced a small change in the risk of failure. As a technical result, operators of electrical substations can now identify the cause of an increase in risk of failure due to pollution in the area. The research provides a contribution towards the behaviour of the leakage current under conditions similar to those of the Colombian Caribbean coast and how they affect the risk of failure of the substation due to pollution. PMID:25634366

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

    SciTech Connect

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

    2006-08-01

    Salmonella enterica serovar Typhimurium (aka, S. typhimurium) is a facultative intracellular pathogen that causes ~40,000 reported cases of acute gastroenteritis and diarrhea a year in the United States. To develop a deeper understanding of the infectious state of S. typhimurium, liquid chromatography-mass spectrometry-based “bottom-up” proteomics was used to globally analyze the proteins present under specific growth conditions. Salmonella typhimurium LT2 strain cells were grown in contrasting culture conditions that mimicked both natural free-living conditions and an infectious state, i.e., logarithm phase, stationary phase and Mg-depleted medium growth. Initial comparisons of the LT2 strain protein abundances among cell culture conditions indicate that the majority of proteins do not change significantly. Not unexpectedly, cells grown in Mg-depleted medium conditions had a higher abundance of Mg2+ transport proteins than found in other growth conditions. A second more virulent Salmonella typhimurium strain (14028) was also studied with these growth conditions and used to directly compare to the LT2 strain. The strain comparison offers a unique opportunity to compare and contrast observations in these closely related bacteria. One particular protein family, propanediol utilization proteins, was drastically more abundant in the 14028 strain than in the LT2 strain, and may be a contributor to increased pathogenicity in the 14028 strain.

  11. Individual consistency and phenotypic plasticity in rockhopper penguins: female but not male body mass links environmental conditions to reproductive investment.

    PubMed

    Dehnhard, Nina; Eens, Marcel; Demongin, Laurent; Quillfeldt, Petra; Poisbleau, Maud

    2015-01-01

    In marine habitats, increasing ocean temperatures due to global climate change may distinctly reduce nutrient and consequently food availability for seabirds. Food availability is a known driver of body mass and reproductive investment in birds, but these traits may also depend on individual effects. Penguins show extreme intra-annual body mass variation and rely on accumulated body reserves for successful breeding. However, no study so far has tested individual consistency and phenotypic responses in body mass and reproductive investment in this taxon. Using a unique dataset on individually marked female and male southern rockhopper penguins (Eudyptes chrysocome chrysocome) across six years, we investigated 1) the individual consistency in body mass (measured at egg laying), body condition and reproductive investment across years, subsequently 2) identified the best-explanatory temperature-related environmental variables for female and male body mass, and 3) tested the effect of female and male body mass on reproductive investment. Body mass, body condition and reproductive investment were all highly repeatable. As body condition should control for the structural size of the birds, the similarly high repeatability estimates for body mass and body condition suggested that the consistent between-individual body mass differences were independent of structural size. This supported the use of body mass for the subsequent analyses. Body mass was higher under colder environmental conditions (positive Southern Annular Mode), but the overall phenotypic response appeared limited. Reproductive investment increased with female but not male body mass. While environmental effects on body mass in our study period were rather small, one can expect that ongoing global climate change will lead to a deterioration of food availability and we might therefore in the long-term expect a phenotypical decline in body mass and reproductive investment. PMID:26030824

  12. Individual Consistency and Phenotypic Plasticity in Rockhopper Penguins: Female but Not Male Body Mass Links Environmental Conditions to Reproductive Investment

    PubMed Central

    Dehnhard, Nina; Eens, Marcel; Demongin, Laurent; Quillfeldt, Petra; Poisbleau, Maud

    2015-01-01

    In marine habitats, increasing ocean temperatures due to global climate change may distinctly reduce nutrient and consequently food availability for seabirds. Food availability is a known driver of body mass and reproductive investment in birds, but these traits may also depend on individual effects. Penguins show extreme intra-annual body mass variation and rely on accumulated body reserves for successful breeding. However, no study so far has tested individual consistency and phenotypic responses in body mass and reproductive investment in this taxon. Using a unique dataset on individually marked female and male southern rockhopper penguins (Eudyptes chrysocome chrysocome) across six years, we investigated 1) the individual consistency in body mass (measured at egg laying), body condition and reproductive investment across years, subsequently 2) identified the best-explanatory temperature-related environmental variables for female and male body mass, and 3) tested the effect of female and male body mass on reproductive investment. Body mass, body condition and reproductive investment were all highly repeatable. As body condition should control for the structural size of the birds, the similarly high repeatability estimates for body mass and body condition suggested that the consistent between-individual body mass differences were independent of structural size. This supported the use of body mass for the subsequent analyses. Body mass was higher under colder environmental conditions (positive Southern Annular Mode), but the overall phenotypic response appeared limited. Reproductive investment increased with female but not male body mass. While environmental effects on body mass in our study period were rather small, one can expect that ongoing global climate change will lead to a deterioration of food availability and we might therefore in the long-term expect a phenotypical decline in body mass and reproductive investment. PMID:26030824

  13. The natural history of diabetic nephropathy: unpredictable insulin requirements--a further clue.

    PubMed

    Avram, M M; Paik, S K; Okanya, D; Rajpal, K

    1984-01-01

    Diabetic nephropathy has evolved into the single most prevalent cause of uremia among patients sustained by the United States End Stage Renal Disease program. Clarification of the natural history of kidney involvement and insufficiency in Type I and II diabetes has improved substantially over the past 5 years. However, it remains a poorly understood and relatively underreported morbid entity. This report reviews the problem, then reconstructs the natural history of diabetic nephropathy by studying the course of 50 Type I and Type II uremic diabetics treated with hemodialysis at The Long Island College Hospital. It traces the various stages from hyperglycemia to proteinuria to renal failure, and then reports morbidity, including cardiac, eye, stroke, and amputation complications. A new paradox is herein reported--the unpredictable insulin requirement, including new insulin need for the first time once hemodialysis was begun, in 8 of 50 patients studied. PMID:6368068

  14. [Comment on Earthquake precursors: Banished forever?] Comment: Unpredictability of earthquakes-Truth or fiction?

    NASA Astrophysics Data System (ADS)

    Lomnitz, Cinna

    I was delighted to read Alexander Gusev's opinions on what he calls the “unpredictability paradigm” of earthquakes (Eos, February 10, 1998, p. 71). I always enjoy hearing from a good friend in the pages of Eos. I immediately looked up “paradigm” in my Oxford Dictionary and found this: paradigm n 1) set of all the different forms of a word: verb paradigms. 2) Type of something; pattern; model: a paradigm for others to copy.I wonder whether Sasha Gusev actually believes that branding earthquake prediction a “proven nonscience” [Geller, 1997] is a paradigm for others to copy. As for me, I choose to refrain from climbing on board this particular bandwagon for the following reasons.

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

    NASA Astrophysics Data System (ADS)

    Batzias, Fragiskos; Kopsidas, Odysseas

    2012-12-01

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

  16. Antidepressant-Like Effects of Cordycepin in a Mice Model of Chronic Unpredictable Mild Stress

    PubMed Central

    Tianzhu, Zhang; Shihai, Yang; Juan, Du

    2014-01-01

    Cordycepin (3?-deoxyadenosine), a major bioactive component isolated from Cordyceps militaris, has multiple pharmacological activities. This study is attempted to investigate whether cordycepin (COR) possesses beneficial effects on chronic unpredictable mild stress- (CUMS-) induced behavioral deficits (depression-like behaviors) and explore the possible mechanisms. ICR mice were subjected to chronic unpredictable mild stress for 42 consecutive days. Then, COR and fluoxetine (FLU, positive control drug) were administered for 21 consecutive days at the last three weeks of CUMS procedure. The classical behavioral tests, open field test (OFT), sucrose preference test (SPT), tail suspension test (TST), and forced swimming test (FST), were applied to evaluate the antidepressant effects of COR. Then the serotonin (5-HT) and noradrenaline (NE) concentrations in hippocampal were evaluated by HPLC; tumor necrosis factor-? (TNF-?) and interleukin-6 (IL-6) in hippocampal were evaluated, and the proteins of TNF-?, IL-6, NF-?BP65 5-HT2A receptor (5-HT2AR), and brain-derived neurotrophic factor (BDNF) in hippocampal were evaluated by Western blot. Our results indicated that 6 weeks of CUMS exposure induced significant depression-like behavior, with low 5-HT and NE levels, high TNF-? and IL-6 in brain and high hippocampal TNF-?, IL-6, P-NF-?BP65, and 5-HT2AR levels, and low BDNF expression levels. Whereas, chronic COR (20, 40?mg/kg) treatments reversed the behavioral deficiency induced by CUMS exposure, treatment with COR normalized the change of TNF-?, IL-6, 5-HT, and NE levels, which demonstrated that COR could partially restore CUMS-induced 5-HT receptor impairments and inflammation. Besides, hippocampal BDNF expressions were also upregulated after COR treatments. In conclusion, COR remarkably improved depression-like behavior in CUMS mice and its antidepressant activity is mediated, at least in part, by the upregulating BDNF and downregulating 5-HT2AR levels and inflammation in hippocampus. PMID:25587342

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

    EPA Science Inventory

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

  18. MEASURES OF GENETIC DIVERSITY ARE EFFECTIVE TOOLS FOR EVALUATING ENVIRONMENTAL CONDITION

    EPA Science Inventory

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

  19. 30 CFR 285.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility? 285.816 Section 285.816 Mineral Resources..., pipeline, or facility? If environmental or other conditions adversely affect a cable, pipeline, or...

  20. Repeated predictable or unpredictable stress: effects on cocaine-induced locomotion and cyclic AMP-dependent protein kinase activity.

    PubMed

    Araujo, Ana Paula N; DeLucia, Roberto; Scavone, Cristoforo; Planeta, Cleopatra S

    2003-02-17

    Stressful experiences appear to have a strong influence on susceptibility to drug taking behavior. Cross-sensitization between stress and drug-induced locomotor response has been found. Locomotor response to novelty or cocaine (10 mg/kg, i.p.), cyclic AMP-dependent protein kinase (PKA) activity in the nucleus accumbens and basal corticosterone levels were evaluated in male adult rats exposed to acute and chronic predictable or unpredictable stress. Rats exposed to a 14-day predictable stress showed increased locomotor response to novelty and to cocaine, whereas rats exposed to chronic unpredictable stress demonstrated increased cyclic AMP-dependent PKA activity in the nucleus accumbens. Both predictable and unpredictable stress increased basal corticosterone plasma levels. These experiments demonstrated that stress-induced early cocaine sensitization depends on the stress regime and is apparently dissociated from stress-induced changes in cyclic AMP-dependent PKA activity and corticosterone levels. PMID:12642178

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

    NASA Astrophysics Data System (ADS)

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

    2014-01-01

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

  2. Seasonal variations of phytoplankton dynamics in Nunatsiavut fjords (Labrador, Canada) and their relationships with environmental conditions

    NASA Astrophysics Data System (ADS)

    Simo-Matchim, Armelle-Galine; Gosselin, Michel; Blais, Marjolaine; Gratton, Yves; Tremblay, Jean-Éric

    2016-04-01

    We assessed phytoplankton dynamics and its environmental control in four Labrador fjords (Nachvak, Saglek, Okak, and Anaktalak) during summer, early fall and late fall. Primary production and chlorophyll a (chl a) biomass were measured at seven optical depths, including the depth of subsurface chl a maximum (SCM). Phytoplankton abundance, size structure and taxonomy were determined at the SCM. Principal component analysis and non-metric multidimensional scaling were used to analyze relationships between production, biomass and community composition in relation to environmental variables. We observed a marked seasonal variability, with significant differences in phytoplankton structure and function between summer and fall. Surprisingly, primary production and chl a biomass were not significantly different from one fjord to another. The highest values of primary production (1730 mg C m- 2 day- 1) and chl a biomass (96 mg chl a m- 2) were measured during the summer bloom, and those high values indicate that Labrador fjords are highly productive ecosystems. The summer community showed relatively high abundance of nanophytoplankton (2-20 μm) while the fall community was characterized by low primary production and chl a biomass as well as relatively high abundance of picophytoplankton (< 2 μm). The low value of carbon potentially exported out of the euphotic zone throughout the study (≤ 31% of total primary production) suggests that phytoplankton production was mainly grazed by microzooplankton rather than being exported to greater depths. We observed a mixed assemblage of diatoms and flagellates in summer, whereas the fall community was largely dominated by flagellates. Seasonal variations in phytoplankton dynamics were mainly controlled by the strength of the vertical stratification and by the large differences in day length due to the northerly location of Labrador fjords. This study documents for the very first time phytoplankton structure and function in Labrador fjords, and provides an essential foundation for further research and for monitoring environmental changes in arctic and subarctic coastal areas.

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

    SciTech Connect

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

    2011-06-01

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

  4. Environmental research on potential pesticides: indispensability and scope under conditions of Poland.

    PubMed

    Gwiazda, M; Gorecka, K

    1983-08-01

    In consideration of the ubiquitous presence of pesticides in the environment, research should be done for each new compound aimed at evaluation of the hazard resulting from its application. Environmental investigations conducted in Poland encompass research on: (a) abiotic transformations (hydrolysis, photodegradation), (b) metabolism in plants and animals, as well as the fate in aquatic and soil environments; (c) influence on biota (including microflora, honey-bee and other beneficial arthropoda, aquatic organisms, birds); (d) side effects (bioaccumulation, resistance, subsequent action of sublethal amounts on populations); (e) mechanisms of action; (f) biological survey of sewage. The data obtained make possible an evaluation of risk connected with application of the investigated compound. PMID:6630895

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

    NASA Technical Reports Server (NTRS)

    Edwards, D. L.

    1993-01-01

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

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

    PubMed

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

    2009-07-01

    Both cultivation and molecular techniques were used to investigate the microbial diversity and dynamic of a deep-sea vent chimney. The enrichment cultures performed in a gas-lift bioreactor were inoculated with a black smoker chimney sample collected on TAG site on the mid-Atlantic ridge. To mimic as close as possible environmental conditions, the cultures were performed in oligotrophic medium with nitrogen, hydrogen and carbon dioxide (N(2)/H(2)/CO(2)) gas sweeping. Also, the temperature was first settled at a temperature of 85 degrees C and colloidal sulphur was added. Then, the temperature was lowered to 60 degrees C and sulphur was omitted. Archaeal and bacterial diversity was studied in both culture and natural samples. Through 16S rRNA gene sequences analysis of the enrichment cultures microorganisms affiliated to Archeoglobales, Thermococcales were detected in both conditions while, Deferribacterales and Thermales were detected only at 65 degrees C in the absence of sulphur. Single-stranded conformational polymorphism and quantitative PCR permit to study the microbial community dynamic during the two enrichment cultures. The effect of environmental changes (modification of culture conditions), i.e. temperature, medium composition, electron donors and acceptors availability were shown to affect the microbial community in culture, as this would happen in their environment. The effect of environmental changes, i.e. temperature and medium composition was shown to affect the microbial community in culture, as this could happen in their environment. The modification of culture conditions, such as temperature, organic matter concentration, electron donors and acceptors availability allowed to enrich different population of prokaryotes inhabiting hydrothermal chimneys. PMID:19381756

  7. Variations in vertical temperature profile of extratropical cyclones under different environmental conditions

    NASA Astrophysics Data System (ADS)

    Karakhanyan, A. A.; Molodykh, S. I.

    2015-11-01

    We study variations in the vertical temperature profile in central parts of warm and cold sectors of extratropical cyclones which emerge and evolve in the Northern Hemisphere during solar minimum. Dynamics of the vertical temperature profile during cyclogenesis over the land and ocean under quiet and disturbed geomagnetic conditions is analyzed. The classic cyclolysis occur under quiet geomagnetic conditions; the temperature decreases in the warm sector and increases in the cold one at a level up to 300 hPa. Under disturbed geomagnetic conditions, there is a slow increase in temperature in the cold sector. The warm sector of the cyclone is characterized by a small increase and stabilization of temperature, which perhaps results in slow cyclolysis and in increased lifetime of cyclones.

  8. Performances of the Radiello ® diffusive sampler for BTEX measurements: Influence of environmental conditions and determination of modelled sampling rates

    NASA Astrophysics Data System (ADS)

    Pennequin-Cardinal, Anne; Plaisance, Hervé; Locoge, Nadine; Ramalho, Olivier; Kirchner, Séverine; Galloo, Jean-Claude

    Radiello ® diffusive samplers filled with a thermally desorbable adsorbent (graphitised carbon Carbograph 4) have been evaluated for the monitoring of BTEX according to the European standard EN 13528-2. Blank values and analytical recovery rates were in agreement with the requirements of this protocol. The sampling rates have been estimated under various controlled atmospheres in order to evaluate the effects of some environmental factors on the performances of the Radiello ® sampler: concentration levels, temperature, exposure time, humidity and wind velocity. The effects of back diffusion and a mixture of 37 VOC have been determined. According to the whole of these results, modelled sampling rates have been set up. These experiments in exposure chamber showed that, for a medium level of concentration in air (5 ?g m -3 for benzene), the expanded uncertainties were between 20% for benzene and 27% for m/ p-xylene under environmental indoor conditions and between 19% for benzene and 31% for m/ p-xylene under environmental outdoor conditions. The result for benzene is conform to the requirements of the future European Directive for benzene which define the maximum of uncertainty to 25% for annual concentrations near 5 ?g m -3.

  9. Droplet-turbulence interactions in sprays exposed to supercritical environmental conditions

    NASA Technical Reports Server (NTRS)

    Santavicca, Domenic A.

    1993-01-01

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

  10. Linking the lytic and lysogenic bacteriophage cycles to environmental conditions, host physiology and their variability in coastal lagoons.

    PubMed

    Maurice, C F; Bouvier, C; de Wit, R; Bouvier, T

    2013-09-01

    Changes in environmental conditions and prokaryote physiology can strongly affect the dynamics of both the lysogenic and lytic bacteriophage replication cycles in aquatic systems. However, it remains unclear whether it is the nature, amplitude or frequency of these changes that alter the phage replication cycles. We performed an annual survey of three Mediterranean lagoons with contrasting levels of chlorophyll a concentration and salinity to explore how these cues and their variability influence either replication cycle. The lytic cycle was always detected and showed seasonal patterns, whereas the lysogenic cycle was often undetected and highly variable. The lytic cycle was influenced by environmental and prokaryotic physiological cues, increasing with concentrations of dissolved organic carbon, chlorophyll a, and the proportion of respiring cells, and decreasing with the proportion of damaged cells. In contrast, lysogeny was not explained by the magnitude of any environmental or physiological parameter, but increased with the amplitude of change in prokaryote physiology. Our study suggests that both cycles are regulated by distinct factors: the lytic cycle is dependent on environmental parameters and host physiology, while lysogeny is dependent on the variability of prokaryote physiology. This could lead to the contrasting patterns observed between both cycles in aquatic systems. PMID:23581698

  11. Changing environmental conditions and applying organic fertilizers in Origanum vulgare L.

    PubMed Central

    Murillo-Amador, Bernardo; Morales-Prado, Luis E.; Troyo-Diéguez, Enrique; Córdoba-Matson, Miguel V.; Hernández-Montiel, Luis G.; Rueda-Puente, Edgar O.; Nieto-Garibay, Alejandra

    2015-01-01

    Any improvement in agricultural systems that results in higher production should also reduce negative environmental impacts and enhance sustainability. The aim of this research was to investigate the effect of two different production systems, one open-field and the other shade-enclosure with four bocashi doses, in order to find the best environmental option in terms of yield, physiological and morphometric characteristics in one oregano (Origanum vulgare L.) cultivar. In this study a completely randomized block design was used with four replications and evaluated for photosynthetic and transpiration rate, stomatal conductance, chlorophyll, leaf area and temperature, aerial and roots fresh and dry biomass, fresh and dry yield. The results showed that oregano adapted best to the shade-enclosure with increase yield of fresh and dry leaf weight of 165% and 118%, respectively, when compared to open-field. Also, higher doses of bocashi improved yield in both environments but more so in shade-enclosure. Soil moisture retention was higher in shade-enclosure which was reflected in physiological variables for soil matric potential, transpiration, stomatal conductivity, photosynthesis being significantly higher in shade-enclosure compared to open-field, thus improving yield. It seems that oregano plants can be grown and perform better under shade-enclosure than open-field and bocashi is a suitable organic fertilizer. PMID:26257756

  12. Reaction norm model to describe environmental sensitivity across first lactation in dairy cattle under tropical conditions.

    PubMed

    Bignardi, Annaiza Braga; El Faro, Lenira; Pereira, Rodrigo Junqueira; Ayres, Denise Rocha; Machado, Paulo Fernando; de Albuquerque, Lucia Galvão; Santana, Mário Luiz

    2015-10-01

    Reaction norm models have been widely used to study genotype by environment interaction (G?×?E) in animal breeding. The objective of this study was to describe environmental sensitivity across first lactation in Brazilian Holstein cows using a reaction norm approach. A total of 50,168 individual monthly test day (TD) milk yields (10 test days) from 7476 complete first lactations of Holstein cattle were analyzed. The statistical models for all traits (10 TDs and for 305-day milk yield) included the fixed effects of contemporary group, age of cow (linear and quadratic effects), and days in milk (linear effect), except for 305-day milk yield. A hierarchical reaction norm model (HRNM) based on the unknown covariate was used. The present study showed the presence of G?×?E in milk yield across first lactation of Holstein cows. The variation in the heritability estimates implies differences in the response to selection depending on the environment where the animals of this population are evaluated. In the average environment, the heritabilities for all traits were rather similar, in range from 0.02 to 0.63. The scaling effect of G?×?E predominated throughout most of lactation. Particularly during the first 2 months of lactation, G?×?E caused reranking of breeding values. It is therefore important to include the environmental sensitivity of animals according to the phase of lactation in the genetic evaluations of Holstein cattle in tropical environments. PMID:26143280

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

    NASA Technical Reports Server (NTRS)

    Boccippio, Dennis J.

    2002-01-01

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

  14. Sunna 535-nm photo-fluorescent film dosimeter response to different environmental conditions

    SciTech Connect

    Murphy, Mark K.; Kovacs, Andras; Mclaughlin, William L.; Miller, Steven D.); Puhl, James M.

    2003-12-01

    Evaluations on the influence of environmental variabilities on the red fluorescence component of the Sunna Model? photo-fluorescent dosimeter have previously been reported. This present paper describes the environmental effects on the response of the green fluorescence component of the same dosimeter, which is manufactured using the injection molding technique. The results presented include temperature, relative humidity, and light influences both during and after irradiation. The green fluorescence signal shows a significant dependence on irradiation temperature below room temperature at 1%/C. Above room temperature (approximately 24C to 60C), the irradiation temperature effect varies from -0.1-1.0%/C, depending on the absorbed dose level. For facilities with irradiation temperatures between 30-60C and absorbed dose levels above 10 kGy, irradiation temperature effects are minimal. Light-effects results indicate that the dosimeter is influenced by ultraviolet and blue wavelengths during irradiation as well as during the post-irradiation stabilization period (approx. 22 hours), requiring the use of light-tight packaging. Results also show that the dosimeter exhibits negligible effects from ambient moisture during and after irradiation when in the range of 33-95% relative humidity.

  15. Characterizing photochemical transformation of aqueous nC60 under environmentally relevant conditions.

    PubMed

    Hwang, Yu Sik; Li, Qilin

    2010-04-15

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

  16. Sunna 535-nm photo-fluorescent film dosimeter response to different environmental conditions

    NASA Astrophysics Data System (ADS)

    Murphy, M. K.; Kovács, A.; McLaughlin, W. L.; Miller, S. D.; Puhl, J. M.

    2003-12-01

    Evaluations on the influence of environmental variabilities on the red fluorescence component of the Sunna Model? photo-fluorescent dosimeter TM have previously been reported. This present paper describes the environmental effects on the response of the green fluorescence component of the same dosimeter, which is manufactured using the injection molding technique. The results presented include temperature, relative humidity, and light influences both during and after irradiation. The green fluorescence signal shows a significant dependence on irradiation temperature below room temperature at 1%/°C. Above room temperature (approximately 24-60°C), the irradiation temperature effect varies from -0.1%/°C to 1.0%/°C, depending on the absorbed dose level. For facilities with irradiation temperatures between 30°C and 60°C and absorbed dose levels above 10 kGy, irradiation temperature effects are minimal. Light-effects results indicate that the dosimeter is influenced by ultraviolet and blue wavelengths during irradiation as well as during the post-irradiation stabilization period (approximately 22 h), requiring the use of light-tight packaging. Results also show that the dosimeter exhibits negligible effects from ambient moisture during and after irradiation when in the range of 33-95% relative humidity.

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

    PubMed Central

    Mering, Satu; Jolkkonen, Jukka

    2015-01-01

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

  18. Reconstructing Historical Environmental Conditions in Pittsburgh Using Tree Ring Metal Concentrations

    NASA Astrophysics Data System (ADS)

    Johnson, A. L.; Bain, D. J.

    2009-12-01

    Urban and industrial activities emit trace metals into the atmosphere, water, and soil. This pollution can affect biota and necessitates an understanding of the effects of human emissions on organisms and systems. Trace metal (lead, copper, cadmium, zinc, and nickel) contamination recorded in a red oak tree (Quercus rubra) from Schenley Park in Pittsburgh, Pennsylvania is used to reconstruct the pollution history over the 126 year life of this tree (1880-2006). Preliminary results found a statistically significant (p<0.05) increases for all metals except nickel when concentrations in the earliest rings (1880-1900) were compared to those in the latest rings (1996-2006). This demonstrates increases in environmental pollution over this time period. Characterization of the remaining rings (1901-1995) will afford an annual record of metal assimilation and direct comparison of metal assimilation with industrial history. This history of regional industrial loadings is being concurrently reconstructed from archival records to understand processes controlling metal concentrations in individual rings. Ultimately this study will improve understanding of environmental pollution in Pittsburgh and the transfer of trace metals into vegetation in general.

  19. Variation of cyanobacteria with different environmental conditions in Nansi Lake, China.

    PubMed

    Tian, Chang; Peil, Haiyan; Hu, Wenrong; Xie, Jun

    2012-01-01

    Nansi Lake is located on the east line of the South-to-North Water Diversion Project in China. A comprehensive study was carried out to investigate the spatial and temporal distribution of cyanobacteria in the lake from June 2008 to May 2011 based on monthly sample monitoring from five stations. The effect of environmental factors on cyanobacterial abundance was also evaluated. The cyanobacterial community contained 15 genera and 23 species. The cyanobacterial abundance of each monitoring station ranged from 0 to 1.53 x 10(7) cells/L with an average of 1.45 x 10(6) cells/L, which accounted for 11.66% of the total phytoplankton abundance. The dominant species of cyanobacteria were Pseudanabaena (32.94%) and Merismopedia (19.85%), not the bloom-forming algae such as Microcystis and Anabaena. In addition, the cyanobacterial community structure and water quality variables changed substantially over the survey period. Redundancy analysis (RDA) suggested that temperature and phosphorus were important environmental factors that affected cyanobacteria. Temperature was the most important factor affecting cyanobacterial abundance. The effect of phosphorus on cyanobacterial abundance was more notable in warm periods than in periods with low temperature. PMID:23513680

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

    PubMed

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

    1991-09-01

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

  1. Basic Environmental Control Devices for Persons with Severe Multiple Handicapping Conditions.

    ERIC Educational Resources Information Center

    Giangreco, Michael F.

    The guide presents a non-technical approach to adapting battery-operated and electrical devices for persons with severe handicapping conditions. The material was developed through Project REACH (Reconstructive Equipment Adaptations for Children with Handicaps). Chapter 1 presents rationales for the use of adapted switches and devices, including…

  2. Basic Environmental Control Devices for Persons with Severe Multiple Handicapping Conditions.

    ERIC Educational Resources Information Center

    Giangreco, Michael F.

    The guide presents a non-technical approach to adapting battery-operated and electrical devices for persons with severe handicapping conditions. The material was developed through Project REACH (Reconstructive Equipment Adaptations for Children with Handicaps). Chapter 1 presents rationales for the use of adapted switches and devices, including…

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

    EPA Science Inventory

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

  4. ASSESSMENT OF FUNGAL GROWTH ON CEILING TILES UNDER ENVIRONMENTALLY CHARACTERIZED CONDITIONS

    EPA Science Inventory

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

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

    EPA Science Inventory

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

  6. THE EFFECT OF EARLY ENVIRONMENTAL MANIPULATION ON LOCOMOTOR SENSITIVITY AND METHAMPHETAMINE CONDITIONED PLACE PREFERENCE REWARD

    PubMed Central

    Hensleigh, E.; Pritchard, L. M.

    2014-01-01

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

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  8. Total environmental warming impact (TEWI) calculations for alternative automative air-conditioning systems

    SciTech Connect

    Sand, J.R.; Fischer, S.K.

    1997-01-01

    The Montreal Protocol phase-out of chlorofluorocarbons (CFCs) has required manufacturers to develop refrigeration and air-conditioning systems that use refrigerants that can not damage stratospheric ozone. Most refrigeration industries have adapted their designs to use hydrochlorofluorocarbon (HCFC) or hydrofluorocarbon (HFC) refrigerants; new automobile air- conditioning systems use HFC-134a. These industries are now being affected by scientific investigations of greenhouse warming and questions about the effects of refrigerants on global warming. Automobile air-conditioning has three separate impacts on global warming; (1) the effects of refrigerant inadvertently released to the atmosphere from accidents, servicing, and leakage; (2) the efficiency of the cooling equipment (due to the emission of C0{sub 2} from burning fuel to power the system); and (3) the emission of C0{sub 2} from burning fuel to transport the system. The Total Equivalent Warming Impact (TEWI) is an index that should be used to compare the global warming effects of alternative air-conditioning systems because it includes these contributions from the refrigerant, cooling efficiency, and weight. This paper compares the TEWI of current air-conditioning systems using HFC-134a with that of transcritical vapor compression system using carbon dioxide and systems using flammable refrigerants with secondary heat transfer loops. Results are found to depend on both climate and projected efficiency of C0{sub 2}systems. Performance data on manufacturing prototype systems are needed to verify the potential reductions in TEWI. Extensive field testing is also required to determine the performance, reliability, and ``serviceability`` of each alternative to HFC-134a to establish whether the potential reduction of TEWI can be achieved in a viable consumer product.

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

    PubMed Central

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

    2013-01-01

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

  10. Biofouling community composition across a range of environmental conditions and geographical locations suitable for floating marine renewable energy generation.

    PubMed

    Macleod, Adrian K; Stanley, Michele S; Day, John G; Cook, Elizabeth J

    2016-03-01

    Knowledge of biofouling typical of marine structures is essential for engineers to define appropriate loading criteria in addition to informing other stakeholders about the ecological implications of creating novel artificial environments. There is a lack of information regarding biofouling community composition (including weight and density characteristics) on floating structures associated with future marine renewable energy generation technologies. A network of navigation buoys were identified across a range of geographical areas, environmental conditions (tidal flow speed, temperature and salinity), and deployment durations suitable for future developments. Despite the perceived importance of environmental and temporal factors, geographical location explained the greatest proportion of the observed variation in community composition, emphasising the importance of considering geography when assessing the impact of biofouling on device functioning and associated ecology. The principal taxa associated with variation in biofouling community composition were mussels (Mytilus edulis), which were also important when determining loading criteria. PMID:26900732

  11. Chronic unpredictable stress exacerbates 7,12-dimethylbenz (a) anthracene induced hepatotoxicity and nephrotoxicity in Swiss albino mice.

    PubMed

    Suhail, Nida; Bilal, Nayeem; Hasan, Shirin; Banu, Naheed

    2011-09-01

    Oxidative stress, a pervasive condition induced by stress has been implicated and recognized to be a prominent feature of various pathological states including cancer and their progression. The present study sought to validate the effectiveness of chronic unpredictable stress (CUS) on hepatic and renal toxicity in terms of alterations of various in vivo biochemical parameters, oxidative stress markers and the extent of DNA damage in Swiss albino mice. Animals were randomized into different groups based on their exposure to CUS alone, 7,12-dimethylbenz (a) anthracene (DMBA) alone (topical), DMBA-12-O-tetradecanoylphorbol-13-acetate (TPA) (topical), and exposure to CUS prior to DMBA or DMBA-TPA treatment, and sacrificed after 16 weeks of treatment. Prior exposure to CUS increased the pro-oxidant effect of carcinogen as depicted by significantly compromised levels of antioxidants; superoxide dismutase, catalase, glutathione-S-transferase, glutathione reductase, reduced glutathione in hepatic and renal tissues accompanied by a significant elevation of thiobarbituric acid reactive species (TBARS) as compared to DMBA alone or DMBA-TPA treatments. Loss of structural integrity at the cellular level due to stress-induced oxidative damage was demonstrated by significant increases in the hepatic levels of intracellular marker enzymes such as glutamate oxaloacetate transaminase, glutamate pyruvate transaminase and alkaline phosphatase, and significantly reduced levels of uric acid in kidney tissues. The results of DNA damage studies further positively correlated with all the above biochemical measurements. Thus, exposure to physical or psychological stress may significantly enhance the hepatotoxic and nephrotoxic potential of carcinogens through enhanced oxidative stress even if the treatment is topical. PMID:21533768

  12. The impact of reproductive investment and early-life environmental conditions on senescence: support for the disposable soma hypothesis.

    PubMed

    Hammers, M; Richardson, D S; Burke, T; Komdeur, J

    2013-09-01

    Several hypotheses have been put forward to explain the evolution of senescence. One of the leading hypotheses, the disposable soma hypothesis, predicts a trade-off, whereby early-life investment in reproduction leads to late-life declines in survival (survival senescence). Testing this hypothesis in natural populations is challenging, but important for understanding the evolution of senescence. We used the long-term data set from a contained, predator-free population of individually marked Seychelles warblers (Acrocephalus sechellensis) to investigate how age-related declines in survival are affected by early-life investment in reproduction and early-life environmental conditions. The disposable soma hypothesis predicts that higher investment in reproduction, or experiencing harsh conditions during early life, will lead to an earlier onset, and an increased rate, of senescence. We found that both sexes showed similar age-related declines in late-life survival consistent with senescence. Individuals that started breeding at a later age showed a delay in survival senescence, but this later onset of breeding did not result in a less rapid decline in late-life survival. Although survival senescence was not directly related to early-life environmental conditions, age of first breeding increased with natal food availability. Therefore, early-life food availability may affect senescence by influencing age of first breeding. The disposable soma hypothesis of senescence is supported by delayed senescence in individuals that started breeding at a later age and therefore invested less in reproduction. PMID:23961923

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

    PubMed Central

    Iwasaki, Yoichiro; Misumi, Masato; Nakamiya, Toshiyuki

    2013-01-01

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

  14. Biofilm formation of the L. monocytogenes strain 15G01 is influenced by changes in environmental conditions.

    PubMed

    Nowak, Jessika; Cruz, Cristina D; Palmer, Jon; Fletcher, Graham C; Flint, Steve

    2015-12-01

    Listeria monocytogenes 15G01, a strain belonging to the persistent pulsotype 5132, was isolated from a seafood processing plant in New Zealand. Simple monoculture assays using crystal violet staining showed good biofilm formation for this strain and it was therefore chosen to be further investigated in regard to its biofilm forming ability. To evaluate its behaviour in different conditions commonly encountered in food processing environments, biofilm assays and growth studies were performed using common laboratory media under a range of temperatures (20°C, 30°C and 37°C). Furthermore, the effects of incubation time and different environmental conditions including static, dynamic and anaerobic incubation on biofilm formation were investigated. Changes in the environmental conditions resulted in different biofilm phenotypes of L. monocytogenes 15G01. We demonstrated that increasing temperature and incubation time led to a higher biofilm mass and that dynamic incubation has little effect on biofilm formation at 37°C but encourages biofilm formation at 30°C. Biofilm production at 20°C was minimal regardless of the medium used. We furthermore observed that anaerobic environment led to reduced biofilm mass at 30°C for all tested media but not at 37°C. Biofilm formation could not be narrowed down to one factor but was rather dependent on multiple factors with temperature and medium having the biggest effects. PMID:26524221

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

    PubMed

    Cooper, Christine Elizabeth; Withers, Philip Carew

    2014-10-15

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

  16. Effect of genotype and environmental conditions on health-promoting compounds in Brassica rapa.

    PubMed

    Francisco, Marta; Cartea, María Elena; Soengas, Pilar; Velasco, Pablo

    2011-03-23

    It is well-known that a variety of factors (genetic and environmental) affect the ultimate metabolite levels in brassica vegetables, although there is still little information about the role that genetics and environment play on glucosinolates and phenolic levels. Total glucosinolates were more abundant in turnip tops (26.02 ?mol g(-1) dw) than in turnip greens (17.78 ?mol g(-1) dw). On the other hand, total phenolic content was found in higher quantities in turnip greens (43.81 ?mol g(-1) dw) than in turnip tops (37.53 ?mol g(-1) dw). Aliphatic glucosinolates were clearly regulated by genotype; in contrast, the effects of environment and genotype×environment interaction on the indolic glucosinolate and phenolic compounds content appeared to be the main effects of variation. Identification of genotypes with enhanced and stable levels of these compounds would provide a value-added opportunity for marketing this crop with superior health promotion to consumers. PMID:21341668

  17. Chromosomes and plant cell division in space: environmental conditions and experimental details.

    PubMed

    Levine, H G; Krikorian, A D

    1992-01-01

    Details of the plant cultivation system developed for the CHROMEX experiment flown aboard the Shuttle Discovery (March, 1989) in NASA's Plant Growth Unit (PGU) are presented. The physical regime as measured during Spaceflight, both within the orbiter cabin environment and within the PGU itself, is discussed. These data function as a guide to what may be representative of the environmental regime in which Space-based plant cultivation systems will be operating, at least for the near-term. Attention is also given to practical considerations involved in conducting a plant experiment in Space. Of particular importance are the differences expected to occur in moisture distribution patterns within substrates used to cultivate plants in Space vs on Earth. PMID:11536992

  18. Male germplasm in relation to environmental conditions: synoptic focus on DNA

    USGS Publications Warehouse

    Jenkins, Jill A.

    2011-01-01

    Wild animals are generally more sensitive than humans to environmental stressors, thus they act as sentinels for resource degradation. Sublethal stress is generally manifested first at the sub-organismal level, where immune systems are compromised, reproductive success is reduced, and genetic integrity is altered. Biomarkers - variables quantifiably responsive to changes in the environment - provide useful information to resource managers and regulatory agencies. Biomarkers of sperm quality are proving useful in this capacity, as well as in artificial breeding. Cellular and molecular bioassays can help to determine mechanisms of action of deleterious agents, predict fertility and reproductive potential, and model population-wide and community level effects. A sequence of biomarker assays can be tailored to fit species of concern, to study physiological effects responsive to known contamination events, and can be selectively applied to fresh, thawed, and fixed samples, as well as those shipped to the laboratory from field sites.

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

    NASA Astrophysics Data System (ADS)

    Lau, Tobias; Lorenz, Enno; Koyuncu, Metin

    2013-04-01

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

  20. Habitat complexity, environmental change and personality: A tropical perspective.

    PubMed

    Pamela Delarue, Emma Michelle; Kerr, Sarah Emily; Lee Rymer, Tasmin

    2015-11-01

    Tropical rainforests are species-rich, complex ecosystems. They are increasingly being negatively affected by anthropogenic activity, which is rapidly and unpredictably altering their structure and complexity. These changes in habitat state may expose tropical animals to novel and unpredictable conditions, potentially increasing their extinction risk. However, an animal's ability to cope with environmental change may be linked to its personality. While numerous studies have investigated environmental influences on animal personalities, few are focused on tropical species. In this review, we consider how behavioural syndromes in tropical species might facilitate coping under, and adapting to, increasing disturbance. Given the complexity of tropical rainforests, we first discuss how habitat complexity influences personality traits and physiological stress in general. We then explore the ecological and evolutionary implications of personality in the tropics in the context of behavioural flexibility, range expansion and speciation. Finally, we discuss the impact that anthropogenic environmental change may have on the ecological integrity of tropical rainforests, positing scenarios for species persistence. Maintaining tropical rainforest complexity is crucial for driving behavioural flexibility and personality type, both of which are likely to be key factors facilitating long term persistence in disturbed habitats. PMID:26386151

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

    PubMed

    Sanderson, Peter; Naidu, Ravi; Bolan, Nanthi

    2016-04-01

    The stabilisation of Pb in the soil by phosphate is influenced by environmental conditions and physicochemical properties of the soils to which it is applied. Stabilisation of Pb by phosphate was examined in four soils under different environmental conditions. The effect of soil moisture and temperature on stabilisation of Pb by phosphate was examined by measurement of water extractable and bioaccessible Pb, sequential fractionation and X-ray absorption spectroscopy. The addition of humic acid, ammonium nitrate and chloride was also examined for inhibition or improvement of Pb stability with phosphate treatment. The effect of moisture level varied between soils. In soil MB and DA a soil moisture level of 50% water holding capacity was sufficient to maximise stabilisation of Pb, but in soil TV and PE reduction in bioaccessible Pb was inhibited at this moisture level. Providing moisture at twice the soil water holding capacity did not enhance the effect of phosphate on Pb stabilisation. The difference of Pb stability as a result of incubating phosphate treated soils at 18 °C and 37 °C was relatively small. However wet-dry cycles decreased the effectiveness of phosphate treatment. The reduction in bioaccessible Pb obtained was between 20 and 40% with the most optimal treatment conditions. The reduction in water extractable Pb by phosphate was substantial regardless of incubation conditions and the effect of different temperature and soil moisture regimes was not significant. Selective sequential extraction showed phosphate treatment converted Pb in fraction 1 (exchangeable, acid and water soluble) to fraction 2 (reducible). There were small difference in fraction 4 (residual) Pb and fraction 1 as a result of treatment conditions. X-ray absorption spectroscopy of stabilised PE soil revealed small differences in Pb speciation under varying soil moisture and temperature treatments. The addition of humic acid and chloride produced the greatest effect on Pb speciation in phosphate treated soils. PMID:26812009

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

    PubMed Central

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

    2012-01-01

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

  3. Periodic oscillations of a model for membrane permeability with fluctuating environmental conditions.

    PubMed

    Torres, Pedro J

    2015-07-01

    We perform an analytical study of the dynamics of a multi-solute model for water transport across a cell membrane under periodic fluctuations of the extracellular solute molalities. Under the presence of non-permeating intracellular solute, water volume experiences periodic oscillations if and only if the extracellular non-permeating solute molality is positive in the average. On the other hand, in the absence of non-permeating intracellular solute, a sufficient condition for the existence of an infinite number of periodic solutions of the model is provided. Such sufficient condition holds automatically in the case of only one permeating solute. The proofs are based on classical tools from the qualitative theory of differential equations, namely Brouwer degree, upper and lower solutions and comparison arguments. PMID:25017486

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

    PubMed Central

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

    2013-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2007-07-01

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

  6. Remotely sensed estimation of annual cotton production under different environmental conditions in Central Greece

    NASA Astrophysics Data System (ADS)

    Domenikiotis, C.; Spiliotopoulos, M.; Tsiros, E.; Dalezios, N. R.

    This study proposes an innovative approach for investigating the accumulated meteorological effects on cotton during the growing season. The quantification of the weather effects is based on the application of the Bhalme and Mooley drought index (BMDI) methodology on the vegetation condition index (VCI) extracted by NOAA/AVHRR data. The resulted Bhalme and Mooley vegetation condition index (BMVCI) is in the same scale as the Z-index, as proposed in the Palmer drought severity index (PDSI) for drought monitoring. The study area comprises the region of Thessaly, which is the most cotton productive area in Greece. Eighteen years of NOAA/AVHRR data are examined and processed with the BMVCI to examine the unfavorable conditions for cotton production. For the validation of BMVCI an empirical relationship between the cotton production of Thessaly and the BMVCI values is derived for the period 1982-1997. The methodology is validated for the two following years (1998 and 1999). The estimated cotton production approximates 5% and 2%, respectively, the real values for the validated years. The results confirm the usefulness of this integrated methodological approach as an effective tool to assess cotton production in Thessaly.

  7. Uranium Biominerals Precipitated by an Environmental Isolate of Serr