WorldWideScience

Sample records for submerged shock response

  1. Identification of a novel submergence response gene regulated by ...

    African Journals Online (AJOL)

    Tuoyo Aghomotsegin

    2016-12-07

    Dec 7, 2016 ... 3Engineering Research Center of Ecology and Agricultural Use of Wetland, Ministry of Education, Yangzte University,. Jingzhou 434025, P.R. .... intolerance to submergence) and M202(Sub1A) by qRT-. PCR. We identified a novel gene responsive to submergence, called RS1. The expression patterns of.

  2. Structural Response of Submerged Air-Backed Plates by Experimental and Numerical Analyses

    Directory of Open Access Journals (Sweden)

    Lloyd Hammond

    2000-01-01

    Full Text Available This paper presents the results of a series of small-scale underwater shock experiments that measured the structural responses of submerged, fully clamped, air-backed, steel plates to a range of high explosive charge sizes. The experimental results were subsequently used to validate a series of simulations using the coupled LS-DYNA/USA finite element/boundary element codes. The modelling exercise was complicated by a significant amount of local cavitation occurring in the fluid adjacent to the plate and difficulties in modelling the boundary conditions of the test plates. The finite element model results satisfactorily predicted the displacement-time history of the plate over a range of shock loadings although a less satisfactory correlation was achieved for the peak velocities. It is expected that the predictive capability of the finite element model will be significantly improved once hydrostatic initialisation can be fully utilised with the LS-DYNA/USA software.

  3. Identification of a novel submergence response gene regulated by ...

    African Journals Online (AJOL)

    Our results also show that RS1 is highly expressed under submergence, drought, and NaCl stresses, but not under cold or dehydration stress. Hormone ABA treatment induces, whereas GA treatment decreases, RS1 expression. The RS1 and Sub1A genes are co-regulated under submergence. Overexpression of RS1 in ...

  4. Structural and Acoustic Responses of a Submerged Stiffened Conical Shell

    Directory of Open Access Journals (Sweden)

    Meixia Chen

    2014-01-01

    Full Text Available This paper studies the vibrational behavior and far-field sound radiation of a submerged stiffened conical shell at low frequencies. The solution for the dynamic response of the conical shell is presented in the form of a power series. A smeared approach is used to model the ring stiffeners. Fluid loading is taken into account by dividing the conical shell into narrow strips which are considered to be local cylindrical shells. The far-field sound pressure is solved by the Element Radiation Superposition Method. Excitations in two directions are considered to simulate the loading on the surface of the conical shell. These excitations are applied along the generator and normal to the surface of the conical shell. The contributions from the individual circumferential modes on the structural responses of the conical shell are studied. The effects of the external fluid loading and stiffeners are discussed. The results from the analytical models are validated by numerical results from a fully coupled finite element/boundary element model.

  5. Physiological and transcriptomic characterization of submergence and reoxygenation responses in soybean seedlings.

    Science.gov (United States)

    Tamang, Bishal G; Magliozzi, Joseph O; Maroof, M A Saghai; Fukao, Takeshi

    2014-10-01

    Complete inundation at the early seedling stage is a common environmental constraint for soybean production throughout the world. As floodwaters subside, submerged seedlings are subsequently exposed to reoxygenation stress in the natural progression of a flood event. Here, we characterized the fundamental acclimation responses to submergence and reoxygenation in soybean at the seedling establishment stage. Approximately 90% of seedlings succumbed during 3 d of inundation under constant darkness, whereas 10 d of submergence were lethal to over 90% of seedlings under 12 h light/12 h dark cycles, indicating the significance of underwater photosynthesis in seedling survival. Submergence rapidly decreased the abundance of carbohydrate reserves and ATP in aerial tissue of seedlings although chlorophyll breakdown was not observed. The carbohydrate and ATP contents were recovered upon de-submergence, but sudden exposure to oxygen also induced lipid peroxidation, confirming that reoxygenation induced oxidative stress. Whole transcriptome analysis recognized genome-scale reconfiguration of gene expression that regulates various signalling and metabolic pathways under submergence and reoxygenation. Comparative analysis of differentially regulated genes in shoots and roots of soybean and other plants defines conserved, organ-specific and species-specific adjustments which enhance adaptability to submergence and reoxygenation through different metabolic pathways. © 2014 John Wiley & Sons Ltd.

  6. Dynamic Response Analysis of Cable of Submerged Floating Tunnel under Hydrodynamic Force and Earthquake

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    Zhiwen Wu

    2017-01-01

    Full Text Available A simplified analysis model of cable for submerged floating tunnel subjected to parametrically excited vibrations in the ocean environment is proposed in this investigation. The equation of motion of the cable is obtained by a mathematical method utilizing the Euler beam theory and the Galerkin method. The hydrodynamic force induced by earthquake excitations is formulated to simulate real seaquake conditions. The random earthquake excitation in the time domain is formulated by the stochastic phase spectrum method. An analytical model for analyzing the cable for submerged floating tunnel subjected to combined hydrodynamic forces and earthquake excitations is then developed. The sensitivity of key parameters including the hydrodynamic, earthquake, and structural parameters on the dynamic response of the cable is investigated and discussed. The present model enables a preliminary examination of the hydrodynamic and seismic behavior of cable for submerged floating tunnel and can provide valuable recommendations for use in design and operation of anchor systems for submerged floating tunnel.

  7. Nonequilibrium volumetric response of shocked polymers

    Energy Technology Data Exchange (ETDEWEB)

    Clements, B E [Los Alamos National Laboratory

    2009-01-01

    Polymers are well known for their non-equilibrium deviatoric behavior. However, investigations involving both high rate shock experiments and equilibrium measured thermodynamic quantities remind us that the volumetric behavior also exhibits a non-equilibrium response. Experiments supporting the notion of a non-equilibrium volumetric behavior will be summarized. Following that discussion, a continuum-level theory is proposed that will account for both the equilibrium and non-equilibrium response. Upon finding agreement with experiment, the theory is used to study the relaxation of a shocked polymer back towards its shocked equilibrium state.

  8. Calculation of a Shock Response Spectra

    Directory of Open Access Journals (Sweden)

    Jiri Tuma

    2011-11-01

    Full Text Available As it is stated in the ISO 18431-4 Standard, a Shock Response Spectrum is defined as the response to a given accelerationacting at a set of mass-damper-spring oscillators, which are adjusted to the different resonance frequencies while their resonancegains (Q-factor are equal to the same value. The maximum of the absolute value of the calculated responses as a function of theresonance frequencies compose the shock response spectrum (SRS. The paper will deal with employing Signal Analyzer, the softwarefor signal processing, for calculation of the SRS. The theory is illustrated by examples.

  9. Constitutive modeling of shock response of PTFE

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Eric N [Los Alamos National Laboratory; Reanyansky, Anatoly D [DSTO, AUSTRALIA; Bourne, Neil K [AWE, UK; Millett, Jeremy C F [AWE, UK

    2009-01-01

    The PTFE (polytetrafluoroethylene) material is complex and attracts attention of the shock physics researchers because it has amorphous and crystalline components. In turn, the crystalline component has four known phases with the high pressure transition to phase III. At the same time, as has been recently studied using spectrometry, the crystalline region is growing with load. Stress and velocity shock-wave profiles acquired recently with embedded gauges demonstrate feature that may be related to impedance mismatches between the regions subjected to some transitions resulting in density and modulus variations. We consider the above mentioned amorphous-to-crystalline transition and the high pressure Phase II-to-III transitions as possible candidates for the analysis. The present work utilizes a multi-phase rate sensitive model to describe shock response of the PTFE material. One-dimensional experimental shock wave profiles are compared with calculated profiles with the kinetics describing the transitions. The objective of this study is to understand the role of the various transitions in the shock response of PTFE.

  10. Contribution of seedling vigour and anoxia/hypoxia-responsive genes to submergence tolerance in Vietnamese lowland rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Hien Thi Thu Vu

    2016-09-01

    Full Text Available A direct-seeded rice cultivation system has been widely adopted in Asian countries. Optimum germination and vigorous seedling growth under submergence are key traits for the practice of direct seeding. We studied the post-germination seedling vigour in Vietnamese lowland rice accessions based on three bio-parameters, shoot elongation growth under five-day submergence in water-filled test-tubes, seedling recovery rate five days after transferring submerged seedlings to pots with soil and seedling survival rate 21 days after sowing seeds in nursery beds and immediate incubation under submergence. A large diversity was found in seedling vigour thus estimated among the accessions. Significantly high correlations were observed among all three bio-parameters, verifying the contribution of seedling vigour to the manifestation of submergence tolerance at this critical stage of rice development. To examine the roles of anoxia/hypoxia-responsive genes, the expression of 17 candidate genes was studied by reverse transcription polymerase chain reaction (RT-PCR and compared between selected vigorous and non-vigorous groups of accessions. Transcripts of all but two genes showed marked accumulation in submerged seedlings. No differences, however, were found between the two contrasting groups. The observed common and coordinate expression of anoxia/hypoxia-induced genes suggests that they might assume roles in attaining baseline tolerance against submergence stress. It was also suggested that some unknown genetic factors are operating in determining cultivar/genotype-specific levels of submergence tolerance as assessed by post-germination seedling vigour.

  11. Video monitoring of sandbar-shoreline response to an offshore submerged structure at a microtidal beach

    Science.gov (United States)

    Bouvier, Clément; Balouin, Yann; Castelle, Bruno

    2017-10-01

    In early 2013, an 800-m long and 12-m wide submerged breakwater with its crest in 2-m depth was implemented at the wave-dominated barred beach of Sète, SE France, to fight against erosion and submersion hazards. Daily video images from April 2011 to April 2016 covering an alongshore distance of 3.5 km are used to analyse the response of both the sandbar(s) and the shoreline to the structure implementation. Results show that the breakwater had a profound impact on the nearshore system, both shoreward of the structure and well away from it alongshore. A progressive rotation and linearisation of the sandbar was observed shoreward of the submerged breakwater. This resulted in the splitting of the sandbar adjacent to the structure during a net offshore sandbar migration event driven by a severe storm in December 2013. The typical formation of a salient or tombolo was not observed. Instead, shoreline coupled to the sandbar geometry, which resulted in a slight seaward migration of the shoreline in front of the structure. Overall, this study highlights that the role of the sandbar is critical to shoreline response to the implementation of breakwaters on barred beaches.

  12. Studies of Physcomitrella patens reveal that ethylene-mediated submergence responses arose relatively early in land-plant evolution

    KAUST Repository

    Yasumura, Yuki

    2012-10-18

    Colonization of the land by multicellular green plants was a fundamental step in the evolution of life on earth. Land plants evolved from fresh-water aquatic algae, and the transition to a terrestrial environment required the acquisition of developmental plasticity appropriate to the conditions of water availability, ranging from drought to flood. Here we show that extant bryophytes exhibit submergence-induced developmental plasticity, suggesting that submergence responses evolved relatively early in the evolution of land plants. We also show that a major component of the bryophyte submergence response is controlled by the phytohormone ethylene, using a perception mechanism that has subsequently been conserved throughout the evolution of land plants. Thus a plant environmental response mechanism with major ecological and agricultural importance probably had its origins in the very earliest stages of the colonization of the land. © 2012 Blackwell Publishing Ltd.

  13. Ethylene response factor BnERF2-like (ERF2.4 from Brassica napus L. enhances submergence tolerance and alleviates oxidative damage caused by submergence in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Yanyan Lv

    2016-06-01

    Full Text Available Ethylene response factor proteins play an important role in regulating a variety of stress responses in plants, but their exact functions in submergence stress are not well understood. In this study, we isolated BnERF2.4 from Brassica napus L. to study its function in submergence tolerance. The expression of the BnERF2.4 gene in B. napus and the expression of antioxidant enzyme genes in transgenic Arabidopsis were analyzed by quantitative RT-PCR. The expression of BnERF2.4 was induced by submergence in B. napus and the overexpression of BnERF2.4 in Arabidopsis increased the level of tolerance to submergence and oxidative stress. A histochemical method detected lower levels of H2O2, O2•− and malondialdehyde (MDA in transgenic Arabidopsis. Compared to the wild type, transgenic lines also had higher soluble sugar content and higher activity of antioxidant enzymes, which helped to protect plants against the oxidative damage caused by submergence. It was concluded that BnERF2.4 increased the tolerance of plants to submergence stress and may be involved in regulating soluble sugar content and the antioxidant system in defense against submergence stress.

  14. Response of sago pondweed, a submerged aquatic macrophyte, to herbicides in three laboratory culture systems

    Science.gov (United States)

    Fleming, W.J.; Ailstock, M.S.; Momot, J.J.; Norman, C.M.; Gorsuch, Joseph W.; Lower, William R.; Wang, Wun-cheng; Lewis, M.A.

    1991-01-01

    The phytotoxicity of atrazine, paraquat, glyphosate, and alachlor to sago pondweed (Potamogeton pectinatus), a submerged aquatic macrophyte, was tested under three types of laboratory culture conditions. In each case, tests were conducted in static systems, the test period was four weeks, and herbicide exposure was chronic, resulting from a single addition of herbicide to the test vessels at the beginning of the test period. The three sets of test conditions employed were(1) axenic cultures in 125-mL flasks containing a nutrient media and sucrose; (2) a microcosm system employing 18.9-L buckets containing a sand, shell, and peat substrate; and (3) an algae-free system employing O.95-L jars containing reconstituted freshwater and a nutrient agar substrate. The primary variable measured was biomass production. Plants grew well in all three test systems, with biomass of untreated plants increasing by a factor of about 5 to 6.5 during the four-week test period. Biomass production in response to herbicide exposure differed significantly among culture systems, which demonstrates the need for a standardized testing protocol for evaluating the effects of toxics on submerged aquatic plants.

  15. Oxygen, pH, and Eh microprofiles around submerged macrophyte Vallisneria natans response to growing stages

    Science.gov (United States)

    Dong, B.; Wang, G. X.; Yu, H. G.

    2017-08-01

    The periphyton, attached to the surfaces of submerged plants, has important effects on plant growth and development in eutrophic waters. Periphyton complicates the microenvironment of diffusive boundary layer around submerged plants. We researched periphyton characteristics, oxygen (O2), pH, and Eh microprofiles at various growing stages of Vallisneria natans. The results suggested that during the growing period of V. natans, O2 concentration and pH decreased from 0 to 2 mm above the leaf surface, whereas the Eh increased. As V. natans grew, O2 and pH gradually increased until they peaked during stable growing stages, while the Eh decreased. However, during the decline stage, O2 and pH gradually decreased, and Eh increased. To summarise, O2 and pH showed a unimodal pattern in response to the life cycle of V. natans, with the maximum levels during the stable growth stage and the minimum levels during the rapid growth and decline stages. Our study demonstrated that V. natans growth induced steep gradients in O2 concentrations, pH, and Eh at the DBL by increasing the layer’s thickness, macrophyte photosynthetic capacity, and periphyton biomass in eutrophic waters.

  16. Toxic shock syndrome responsive to steroids

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    Vergis Nikhil

    2007-02-01

    Full Text Available Abstract Background Toxic Shock Syndrome is a dangerous disease with clinical features mimicking bacterial sepsis. The best management of Toxic Shock Syndrome is not determined. Case presentation A 28 year-old woman presenting with high fever, tachycardia and widespread erythroderma is described. She failed to respond to intravenous antibiotics and required ITU admission. High dose corticosteroids dramatically improved her clinical condition. Conclusion Toxic Shock Syndrome should be considered in the differential diagnosis of unexplained fever, rash and features resembling septic shock. Corticosteroids should be considered in the treatment of Toxic Shock Syndrome.

  17. The changing macroeconomic response to stock market volatility shocks

    NARCIS (Netherlands)

    Beetsma, R.M.W.J.; Giuliodori, M.

    2012-01-01

    There is substantial consensus in the literature that positive uncertainty shocks predict a slowdown of economic activity. However, using US data since 1950 we show that the macroeconomic response pattern to stock market volatility shocks has changed substantially over time. The negative response of

  18. The changing macroeconomic response to stock market volatility shocks

    NARCIS (Netherlands)

    Beetsma, R.; Giuliodori, M.

    2011-01-01

    There is substantial consensus in the literature that positive uncertainty shocks predict a slowdown of economic activity. However, using U.S. data since 1950 we show that the macroeconomic response pattern to stock market volatility shocks has changed substantially over time. The negative response

  19. Systemic analysis of heat shock response induced by heat shock and a proteasome inhibitor MG132.

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    Hee-Jung Kim

    Full Text Available The molecular basis of heat shock response (HSR, a cellular defense mechanism against various stresses, is not well understood. In this, the first comprehensive analysis of gene expression changes in response to heat shock and MG132 (a proteasome inhibitor, both of which are known to induce heat shock proteins (Hsps, we compared the responses of normal mouse fibrosarcoma cell line, RIF-1, and its thermotolerant variant cell line, TR-RIF-1 (TR, to the two stresses. The cellular responses we examined included Hsp expressions, cell viability, total protein synthesis patterns, and accumulation of poly-ubiquitinated proteins. We also compared the mRNA expression profiles and kinetics, in the two cell lines exposed to the two stresses, using microarray analysis. In contrast to RIF-1 cells, TR cells resist heat shock caused changes in cell viability and whole-cell protein synthesis. The patterns of total cellular protein synthesis and accumulation of poly-ubiquitinated proteins in the two cell lines were distinct, depending on the stress and the cell line. Microarray analysis revealed that the gene expression pattern of TR cells was faster and more transient than that of RIF-1 cells, in response to heat shock, while both RIF-1 and TR cells showed similar kinetics of mRNA expression in response to MG132. We also found that 2,208 genes were up-regulated more than 2 fold and could sort them into three groups: 1 genes regulated by both heat shock and MG132, (e.g. chaperones; 2 those regulated only by heat shock (e.g. DNA binding proteins including histones; and 3 those regulated only by MG132 (e.g. innate immunity and defense related molecules. This study shows that heat shock and MG132 share some aspects of HSR signaling pathway, at the same time, inducing distinct stress response signaling pathways, triggered by distinct abnormal proteins.

  20. The Structural Response of Cylindrical Shells to Internal Shock Loading

    NARCIS (Netherlands)

    Beltman, W.M.; Burcsu, E.N.; Shepherd, J.E.; Zuhal, L.

    The internal shock loading of cylindrical shells can be represented as a step load advancing at constant speed. Several analytical models are available to calculate the structural response of shells to this type of loading. These models show that the speed of the shock wave is an important

  1. Differential Response of Floating and Submerged Leaves of Longleaf Pondweed to Silver Ions

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    Nisha Shabnam

    2017-06-01

    Full Text Available In this study, we have investigated variations in the potential of floating and submerged leaves of longleaf pondweed (Potamogeton nodosus to withstand silver ion (Ag+-toxicity. Both floating and submerged leaves changed clear colorless AgNO3 solutions to colloidal brown in the presence of light. Transmission electron microscopy revealed the presence of distinct crystalline Ag-nanoparticles (Ag-NPs in these brown solutions. Powder X-ray diffraction pattern showed that Ag-NPs were composed of Ag0 and Ag2O. Photosystem (PS II efficiency of leaves declined upon exposure to Ag+ with a significantly higher decline in the submerged leaves than in the floating leaves. Similarly, Ag+ treatment caused a significant reduction in the carboxylase activity of the ribulose bisphosphate carboxylase/oxygenase in leaves. The reduction in this carboxylase activity was significantly higher in the submerged than in the floating leaves. Ag+ treatment also resulted in a significant decline in the levels of non-enzymatic and enzymatic antioxidants; the decline was significantly lower in the floating than in submerged leaves. X-ray photoelectron spectroscopy revealed the presence of Ag2O in these leaves. Inductively coupled plasma mass spectrometry analysis revealed a three-fold higher Ag content in the submerged than in floating leaves. Our study demonstrates that floating leaves of longleaf pondweed have a superior potential to counter Ag+-toxicity compared with submerged leaves, which could be due to superior potential of floating leaves to reduce Ag+ to less/non-toxic Ag0/Ag2O-nanoparticles/nanocomplexes. We suggest that modulating the genotype of longleaf pondweed to bear higher proportion of floating leaves would help in cleaning fresh water bodies contaminated with ionic forms of heavy metals.

  2. The carbon starvation response of Aspergillus niger during submerged cultivation: Insights from the transcriptome and secretome

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    Nitsche Benjamin M

    2012-08-01

    Full Text Available Abstract Background Filamentous fungi are confronted with changes and limitations of their carbon source during growth in their natural habitats and during industrial applications. To survive life-threatening starvation conditions, carbon from endogenous resources becomes mobilized to fuel maintenance and self-propagation. Key to understand the underlying cellular processes is the system-wide analysis of fungal starvation responses in a temporal and spatial resolution. The knowledge deduced is important for the development of optimized industrial production processes. Results This study describes the physiological, morphological and genome-wide transcriptional changes caused by prolonged carbon starvation during submerged batch cultivation of the filamentous fungus Aspergillus niger. Bioreactor cultivation supported highly reproducible growth conditions and monitoring of physiological parameters. Changes in hyphal growth and morphology were analyzed at distinct cultivation phases using automated image analysis. The Affymetrix GeneChip platform was used to establish genome-wide transcriptional profiles for three selected time points during prolonged carbon starvation. Compared to the exponential growth transcriptome, about 50% (7,292 of all genes displayed differential gene expression during at least one of the starvation time points. Enrichment analysis of Gene Ontology, Pfam domain and KEGG pathway annotations uncovered autophagy and asexual reproduction as major global transcriptional trends. Induced transcription of genes encoding hydrolytic enzymes was accompanied by increased secretion of hydrolases including chitinases, glucanases, proteases and phospholipases as identified by mass spectrometry. Conclusions This study is the first system-wide analysis of the carbon starvation response in a filamentous fungus. Morphological, transcriptomic and secretomic analyses identified key events important for fungal survival and their chronology. The

  3. The dynamic response of electrostatically driven resonators under mechanical shock

    Science.gov (United States)

    Ibrahim, Mahmoud I.; Younis, Mohammad I.

    2010-02-01

    This paper presents a theoretical and experimental investigation of the response of electrostatically actuated parallel-plate resonators when subjected to mechanical shock. Resonators are commonly employed in resonant sensors, where they are operated at low pressure for enhanced sensitivity making their response to external disturbances such as shock a critical issue. A single-degree-of-freedom system is used to model a resonator, which is electrostatically driven by a dc load superimposed to an ac harmonic load. Simulation results are demonstrated in a series of shock spectra that help indicate the combined influence of shock, dc and ac loads. The effect of the shock duration coinciding with the ac harmonic frequency is investigated. It is concluded that accounting for electrostatic forces, especially the ac load, is crucial when addressing the reliability and performance of resonators against shock. It is found that for specific shock and ac excitation conditions, a resonator may experience early dynamic pull-in instability. Experimental work has been conducted on a capacitive sensor to verify the obtained theoretical results. The sensor is mounted on top of a small shaker and then both are placed inside a vacuum chamber. Acceleration pulses were applied on the sensor while powered by dc and ac loads. The response of the device was monitored using a laser-Doppler vibrometer. The experimental data were compared to the theoretical results and were found to be in good agreement.

  4. Clonal variation in the thermal response of the submerged aquatic macrophyte Potamogeton pectinatus

    NARCIS (Netherlands)

    Pilon, J.; Santamaria, L.

    2002-01-01

    Broadly distributed plants have to cope with dramatic differences across latitude in the prevailing environmental temperature. We investigated the effect of water temperature on plant morphology, biomass accumulation and oxygen-exchange for five clones of the submerged aquatic macrophyte Potamogeton

  5. Differential response to climatic variation of free-floating and submerged macrophytes in ditches

    NARCIS (Netherlands)

    Netten, J.J.C.; Zuidam, van J.P.; Kosten, S.; Peeters, E.T.H.M.

    2011-01-01

    1. Experimental studies have indicated in freshwater ecosystems that a shift in dominance from submerged to free-floating macrophytes may occur with climate change because of increased water surface temperatures and eutrophication. Field evidence is, however, rare. 2. Here, we analysed long-term (26

  6. Observations of the shock response of specific piezo resistive accelerometers

    Science.gov (United States)

    Benham, R. A.; Duggins, B. D.

    1992-02-01

    Pyro shock loads are generated in many missile or rocket systems when stages are separated or shrouds are removed. These shocks are localized, of short rise time (10's of nanoseconds) and of very high stress level. This paper will document some anomalous behavior that occurs when pyro shock accelerometers (Endevco 7270A) are exposed to levels of high frequency shock that is higher than the manufacturer's recommended limits. Such shocks occur in many pyro shock events. Standard, accepted recording techniques can produce totally erroneous data with no obvious indicator that the data is in error. Wide band data recording, along with Fourier Analysis of the data, and dynamic analysis, made by the gage manufacturer of the transducer, allow recognition of some of the non-standard response modes excited but no method of quantifying the corrupted data has been developed. Wide band recording, which will preserve the data in the gage resonance range and above, are required to insure understanding of these pyro shock events.

  7. Plasticity as a plastic response: how submergence-induced leaf elongation in Rumex palustris depends on light and nutrient availability in its early life stage.

    Science.gov (United States)

    Huber, Heidrun; Chen, Xin; Hendriks, Marloes; Keijsers, Danny; Voesenek, Laurentius A C J; Pierik, Ronald; Poorter, Hendrik; de Kroon, Hans; Visser, Eric J W

    2012-04-01

    Plants may experience different environmental cues throughout their development which interact in determining their phenotype. This paper tests the hypothesis that environmental conditions experienced early during ontogeny affect the phenotypic response to subsequent environmental cues. This hypothesis was tested by exposing different accessions of Rumex palustris to different light and nutrient conditions, followed by subsequent complete submergence. Final leaf length and submergence-induced plasticity were affected by the environmental conditions experienced at early developmental stages. In developmentally older leaves, submergence-induced elongation was lower in plants previously subjected to high-light conditions. Submergence-induced elongation of developmentally younger leaves, however, was larger when pregrown in high light. High-light and low-nutrient conditions led to an increase of nonstructural carbohydrates in the plants. There was a positive correlation between submergence-induced leaf elongation and carbohydrate concentration and content in roots and shoots, but not with root and shoot biomass before submergence. These results show that conditions experienced by young plants modulate the responses to subsequent environmental conditions, in both magnitude and direction. Internal resource status interacts with cues perceived at different developmental stages in determining plastic responses to the environment. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  8. Barcoding heat shock proteins to human diseases : looking beyond the heat shock response

    NARCIS (Netherlands)

    Kakkar, Vaishali; Meister-Broekema, Melanie; Minoia, Melania; Carra, Serena; Kampinga, Harm H.

    There are numerous human diseases that are associated with protein misfolding and the formation of toxic protein aggregates. Activating the heat shock response (HSR) - and thus generally restoring the disturbed protein homeostasis associated with such diseases - has often been suggested as a

  9. Experimental Investigation for Multi-Response Optimization of Bead Geometry in Submerged Arc Welding using Grey Analysis

    Science.gov (United States)

    Bhattacharya, A.; Batish, A.; Kumar, P.

    2012-06-01

    The present study was aimed at studying the effect of type and composition of flux, welding current, arc voltage, and travel speed on depth of penetration, bead height and bead width (bead geometry responses) and to optimize the process considering multi-response criteria in a submerged arc welding process. Using the grey relational analysis technique three responses were combined into a single grey relational grade and was analyzed using Analysis of Variance. Since the three responses had conflicting requirements, optimization of the complicated multiple performance characteristics was greatly simplified through this approach. The emperical relationship between the multi-response grey relational grade and the input parameters was developed using regression analysis which was used to predict the value of the grey relational grade using the optimal parameter levels.

  10. Hormonal modulation of the heat shock response: insights from fish with divergent cortisol stress responses

    DEFF Research Database (Denmark)

    LeBlanc, Sacha; Höglund, Erik; Gilmour, Kathleen M.

    2012-01-01

    shock response, we capitalized on two lines of rainbow trout specifically bred for their high (HR) and low (LR) cortisol response to stress. We predicted that LR fish, with a low cortisol but high catecholamine response to stress, would induce higher levels of HSPs after acute heat stress than HR trout......Acute temperature stress in animals results in increases in heat shock proteins (HSPs) and stress hormones. There is evidence that stress hormones influence the magnitude of the heat shock response; however, their role is equivocal. To determine whether and how stress hormones may affect the heat....... We found that HR fish have significantly higher increases in both catecholamines and cortisol compared with LR fish, and LR fish had no appreciable stress hormone response to heat shock. This unexpected finding prevented further interpretation of the hormonal modulation of the heat shock response...

  11. Exploring the Dynamics of Responses to Food Production Shocks

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    Aled Jones

    2017-06-01

    Full Text Available Food production shocks can lead to food crises where access to appropriate quantities and quality of food become inadequate, unaffordable, or unreliable on a major scale. While the physical causes of food production shocks are well researched, the dynamics of responses to them are less well understood. This paper reviews those dynamics and includes evidence gathered via interviews of 44 expert practitioners sourced globally from academia, government, industry, think-tanks, and development/relief organizations. The paper confirms that policy interventions are often prioritised for national interests and poorly coordinated at regional and global scales. The paper acknowledges future compounding trends such as climate change and demographic shifts and suggests that while there are signs of incremental progress in better managing the impacts of shock events, coordinated responses at scale will require a paradigm shift involving major policy, market, and technological advancements, and a wide range of public and private sector stakeholders.

  12. The Characteristic Response of Whistler Mode Waves to Interplanetary Shocks

    Science.gov (United States)

    Yue, Chao; Chen, Lunjin; Bortnik, Jacob; Ma, Qianli; Thorne, Richard M.; Angelopoulos, Vassilis; Li, Jinxing; An, Xin; Zhou, Chen; Kletzing, Craig; Reeves, Geoffrey D.; Spence, Harlan E.

    2017-10-01

    Magnetospheric whistler mode waves play a key role in regulating the dynamics of the electron radiation belts. Recent satellite observations indicate a significant influence of interplanetary (IP) shocks on whistler mode wave power in the inner magnetosphere. In this study, we statistically investigate the response of whistler mode chorus and plasmaspheric hiss to IP shocks based on Van Allen Probes and THEMIS satellite observations. Immediately after the IP shock arrival, chorus wave power is usually intensified, often at postmidnight to prenoon sector, while plasmaspheric hiss wave power predominantly decreases near the dayside but intensifies near the nightside. We conclude that chorus wave intensification outside the plasmasphere is probably associated with the suprathermal electron flux enhancement caused by the IP shock. Through a simple ray tracing modeling assuming the scenario that plasmaspheric hiss is originated from chorus, we find that the solar wind dynamic pressure increase changes the magnetic field configuration to favor ray penetration in the nightside and promote ray refraction away from the dayside, potentially explaining the magnetic local time-dependent responses of plasmaspheric hiss waves following IP shock arrivals.

  13. Accurate Determination of the Frequency Response Function of Submerged and Confined Structures by Using PZT-Patches†

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    Alexandre Presas

    2017-03-01

    Full Text Available To accurately determine the dynamic response of a structure is of relevant interest in many engineering applications. Particularly, it is of paramount importance to determine the Frequency Response Function (FRF for structures subjected to dynamic loads in order to avoid resonance and fatigue problems that can drastically reduce their useful life. One challenging case is the experimental determination of the FRF of submerged and confined structures, such as hydraulic turbines, which are greatly affected by dynamic problems as reported in many cases in the past. The utilization of classical and calibrated exciters such as instrumented hammers or shakers to determine the FRF in such structures can be very complex due to the confinement of the structure and because their use can disturb the boundary conditions affecting the experimental results. For such cases, Piezoelectric Patches (PZTs, which are very light, thin and small, could be a very good option. Nevertheless, the main drawback of these exciters is that the calibration as dynamic force transducers (relationship voltage/force has not been successfully obtained in the past. Therefore, in this paper, a method to accurately determine the FRF of submerged and confined structures by using PZTs is developed and validated. The method consists of experimentally determining some characteristic parameters that define the FRF, with an uncalibrated PZT exciting the structure. These parameters, which have been experimentally determined, are then introduced in a validated numerical model of the tested structure. In this way, the FRF of the structure can be estimated with good accuracy. With respect to previous studies, where only the natural frequencies and mode shapes were considered, this paper discuss and experimentally proves the best excitation characteristic to obtain also the damping ratios and proposes a procedure to fully determine the FRF. The method proposed here has been validated for the

  14. Accurate Determination of the Frequency Response Function of Submerged and Confined Structures by Using PZT-Patches†.

    Science.gov (United States)

    Presas, Alexandre; Valentin, David; Egusquiza, Eduard; Valero, Carme; Egusquiza, Mònica; Bossio, Matias

    2017-03-22

    To accurately determine the dynamic response of a structure is of relevant interest in many engineering applications. Particularly, it is of paramount importance to determine the Frequency Response Function (FRF) for structures subjected to dynamic loads in order to avoid resonance and fatigue problems that can drastically reduce their useful life. One challenging case is the experimental determination of the FRF of submerged and confined structures, such as hydraulic turbines, which are greatly affected by dynamic problems as reported in many cases in the past. The utilization of classical and calibrated exciters such as instrumented hammers or shakers to determine the FRF in such structures can be very complex due to the confinement of the structure and because their use can disturb the boundary conditions affecting the experimental results. For such cases, Piezoelectric Patches (PZTs), which are very light, thin and small, could be a very good option. Nevertheless, the main drawback of these exciters is that the calibration as dynamic force transducers (relationship voltage/force) has not been successfully obtained in the past. Therefore, in this paper, a method to accurately determine the FRF of submerged and confined structures by using PZTs is developed and validated. The method consists of experimentally determining some characteristic parameters that define the FRF, with an uncalibrated PZT exciting the structure. These parameters, which have been experimentally determined, are then introduced in a validated numerical model of the tested structure. In this way, the FRF of the structure can be estimated with good accuracy. With respect to previous studies, where only the natural frequencies and mode shapes were considered, this paper discuss and experimentally proves the best excitation characteristic to obtain also the damping ratios and proposes a procedure to fully determine the FRF. The method proposed here has been validated for the structure vibrating

  15. Households' vulnerability and responses to shocks: evidence from rural Kenya

    NARCIS (Netherlands)

    Ndirangu, L.

    2007-01-01

    Key words: Vulnerability, HIV/AIDS, weather shocks, risk management, coping strategies, rural households, gender.   Empirical investigation on household’s responses to sources of vulnerability is important for designing and implementation of social policies. The design of an effective

  16. Response Functions to Critical Shocks in Social Sciences:

    Science.gov (United States)

    Roehner, B. M.; Sornette, D.; Andersen, J. V.

    We show that, provided one focuses on properly selected episodes, one can apply to the social sciences the same observational strategy that has proved successful in natural sciences such as astrophysics or geodynamics. For instance, in order to probe the cohesion of a society, one can, in different countries, study the reactions to some huge and sudden exogenous shocks, which we call Dirac shocks. This approach naturally leads to the notion of structural (as opposed or complementary to temporal) forecast. Although structural predictions are by far the most common way to test theories in the natural sciences, they have been much less used in the social sciences. The Dirac shock approach opens the way to testing structural predictions in the social sciences. The examples reported here suggest that critical events are able to reveal pre-existing "cracks" because they probe the social cohesion which is an indicator and predictor of future evolution of the system, and in some cases they foreshadow a bifurcation. We complement our empirical work with numerical simulations of the response function ("damage spreading") to Dirac shocks in the Sznajd model of consensus build-up. We quantify the slow relaxation of the difference between perturbed and unperturbed systems, the conditions under which the consensus is modified by the shock and the large variability from one realization to another.

  17. Heat shock response improves heterologous protein secretion in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Hou, Jin; Österlund, Tobias; Liu, Zihe

    2013-01-01

    The yeast Saccharomyces cerevisiae is a widely used platform for the production of heterologous proteins of medical or industrial interest. However, heterologous protein productivity is often low due to limitations of the host strain. Heat shock response (HSR) is an inducible, global, cellular...... stress response, which facilitates the cell recovery from many forms of stress, e.g., heat stress. In S. cerevisiae, HSR is regulated mainly by the transcription factor heat shock factor (Hsf1p) and many of its targets are genes coding for molecular chaperones that promote protein folding and prevent......, human insulin precursor was only improved slightly and this only by high level over-expression of HSF1-R206S, supporting our previous findings that the production of this protein in S. cerevisiae is not limited by secretion. Our results provide an effective strategy to improve protein secretion...

  18. EXPERIMENTAL EVALUATION OF SHOCK SPECTRUM RESPONSE OF ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    A. V. Tretiakov

    2017-06-01

    Full Text Available Purpose. The article is aimed to analyze the increase in the effectiveness of traditional methods for carrying out shock tests of land vehicles, in order to assess their strength, reliability and durability. Methodology. To achieve this purpose, the authors of the article developed a technique for conducting impact tests and effective algorithm based on the ideas and methodological proposals contained in the UN Guidelines on the “Recommendations for Transportations of Dangerous Goods”. Findings. With the use of the modern programming language SI-Sharp, a specialized software package was created that implements the algorithm for handling shock processes, which has a "friendly" interface with the user of this complex and other software products of the computing environment powered by Windows. With the application of this complex, the results of tests of the tank-container of the model CTL-26/0.4, type UN T14 under different shock loading (collision rates, geometric, inertial and damping parameters of this design were processed. As a result, an objective evaluation of the properties of the tested object was obtained, and a conclusion was made that the calculated shock response spectrum (SRS was exceeded, its minimum permissible value in the entire spectrum of the investigated frequencies. Originality. For the first time, a complex theoretical and practical approach to the study of the strength, reliability, and durability of transport mechanical structures subjected to impact loads on the basis of the evaluation of the impact response spectra was realized. Practical value. The application of the proposed methodology and the developed software package for carrying out shock tests made it possible to increase the reliability of these tests, to shorten the time of their testing and to process the results. The results of the testing of the tank-container tests showed that this vehicle fully provides the required normative parameters of strength

  19. Systemic inflammatory response syndrome: a case of septic shock

    Directory of Open Access Journals (Sweden)

    Nicolò Gentiloni Silveri

    2008-09-01

    Full Text Available An elderly, diabetic male, with severe sepsis, swiftly treated with antibiotics that were efficacious in vitro against the E. Coli isolated in his blood, rapidly slides into multiple organ dysfunction syndrome and dies of septic shock after a month in intensive care, despite receiving appropriate pain relief and aetiopathogenetic therapy. This event provides us with the opportunity to take a new look at systemic inflammatory response syndrome and a critical review of the relative therapy

  20. Climate change effects on agriculture: economic responses to biophysical shocks.

    Science.gov (United States)

    Nelson, Gerald C; Valin, Hugo; Sands, Ronald D; Havlík, Petr; Ahammad, Helal; Deryng, Delphine; Elliott, Joshua; Fujimori, Shinichiro; Hasegawa, Tomoko; Heyhoe, Edwina; Kyle, Page; Von Lampe, Martin; Lotze-Campen, Hermann; Mason d'Croz, Daniel; van Meijl, Hans; van der Mensbrugghe, Dominique; Müller, Christoph; Popp, Alexander; Robertson, Richard; Robinson, Sherman; Schmid, Erwin; Schmitz, Christoph; Tabeau, Andrzej; Willenbockel, Dirk

    2014-03-04

    Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change's representative concentration pathway with end-of-century radiative forcing of 8.5 W/m(2). The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change.

  1. Climate Change Effects on Agriculture: Economic Responses to Biophysical Shocks

    Science.gov (United States)

    Nelson, Gerald C.; Valin, Hugo; Sands, Ronald D.; Havlik, Petr; Ahammad, Helal; Deryng, Delphine; Elliott, Joshua; Fujimori, Shinichiro; Hasegawa, Tomoko; Heyhoe, Edwina

    2014-01-01

    Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change's representative concentration pathway with end-of-century radiative forcing of 8.5 W/m(sup 2). The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change.

  2. The potential of heat shock response in the treatment of theileriosis ...

    African Journals Online (AJOL)

    Although the actual mechanism of this approach remains enigmatic, it might be linked with the protective role of heat shock response observed in several conditions. This prompts for closer look into the possible protective mechanisms of heat shock response against theileriosis. By gaining insight into how the heat shock ...

  3. On the shock response of the magnesium alloy Elektron 675

    Science.gov (United States)

    Hazell, Paul; Appleby-Thomas, Gareth; Siviour, Clive; Wielewski, Euan

    2011-06-01

    Alloying elements such as aluminium, zinc or rare-earths allow precipitation hardening of magnesium (Mg). The low densities of such strengthened Mg alloys have led to their adoption as aerospace materials and (more recently) they are being considered as armour materials. Consequently, understanding their response to high-strain rate loading is becoming increasingly important. Here, the plate-impact technique was employed to measure longitudinal stress evolution in armour-grade wrought Mg-alloy Elektron 675 under 1D shock loading. The strength and spall behaviour was interrogated, with an estimate made of the material's Hugoniot elastic limit. Finally, electron backscatter diffraction (EBSD) techniques were employed to investigate post-shock microstructural changes.

  4. Molecular shock response of explosives: electronic absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mcgrne, Shawn D [Los Alamos National Laboratory; Moore, David S [Los Alamos National Laboratory; Whitley, Von H [Los Alamos National Laboratory; Bolme, Cindy A [Los Alamos National Laboratory; Eakins, Daniel E [Los Alamos National Laboratory

    2009-01-01

    Electronic absorption spectroscopy in the range 400-800 nm was coupled to ultrafast laser generated shocks to begin addressing the question of the extent to which electronic excitations are involved in shock induced reactions. Data are presented on shocked polymethylmethacrylate (PMMA) thin films and single crystal pentaerythritol tetranitrate (PETN). Shocked PMMA exhibited thin film interference effects from the shock front. Shocked PETN exhibited interference from the shock front as well as broadband increased absorption. Relation to shock initiation hypotheses and the need for time dependent absorption data (future experiments) is briefly discussed.

  5. Dyanmic Response to Monetary Shocks in a Search Model of the Labor Market

    OpenAIRE

    Alvaro Riascos

    2002-01-01

    This paper studies the dynamic response of a few key macroeconomic variables to each one of three exogenous shocks: monetary, government spending and technological shocks. By using a cash in advance model with two market frictions, one in the intermediation of loanable funds, and one in the labor market, we address the ability of the model to simulate data embedded with the same dynamic response to shocks observed in historical data (i.e we estimate dynamic multipliers to exogenous shocks by ...

  6. A SIMPLE EXPERIMENTAL MODEL OF HEAT SHOCK RESPONSE IN RATS

    Directory of Open Access Journals (Sweden)

    Tufi Neder Meyer

    1998-10-01

    Full Text Available Objective: To obtain a simple model for the elicitation of the heat shock response in rats. Design: Laboratory study. Setting: University research laboratories. Sample: Seventy-nine adult male albino rats (weight range 200 g to 570 g. Procedures: Exposure to heat stress by heating animals in a warm bath for 5 min after their rectal temperatures reached 107.60 F (420 C. Liver and lung samples were collected for heat-shock protein 70 (HSP70 detection (Western analysis. Results: Western analysis was positive for HSP70 in the liver and in the lungs of heated animals. There was a temporal correlation between heating and HSP70 detection: it was strongest 1 day after heating and reduced afterwards. No heated animals died. Conclusion: These data show that heating rats in a warm (45o C bath, according to parameters set in this model, elicits efficiently the heat shock response.OBJETIVO: Obter um modelo simples para tentar esclarecer a resposta ao choque térmico em ratos. LOCAL: Laboratório de pesquisa da Universidade. MÉTODO: Amostra: 79 ratos albinos, adultos, entre 200g a 570g. Procedimentos: Exposição ao calor, em banho quente, por 5 minutos, após a temperatura retal chegar a 42 graus centigrados. Biópsias de fígado e pulmão foram obtidas para detectar a proteina 70 (HSP 70, pelo "Western blot". RESULTADOS: As análises foram positivas nos animais aquecidos, com uma correlação entre aquecimento e constatação da HSP 70. Foi mais elevada no primeiro dia e não houve óbitos nos animais aquecidos. CONCLUSÃO: Os ratos aquecidos a 45 graus centígrados respondem eficientemente ao choque térmico.

  7. Integrative analysis of the heat shock response in Aspergillus fumigatus

    Directory of Open Access Journals (Sweden)

    Brakhage Axel A

    2010-01-01

    Full Text Available Abstract Background Aspergillus fumigatus is a thermotolerant human-pathogenic mold and the most common cause of invasive aspergillosis (IA in immunocompromised patients. Its predominance is based on several factors most of which are still unknown. The thermotolerance of A. fumigatus is one of the traits which have been assigned to pathogenicity. It allows the fungus to grow at temperatures up to and above that of a fevered human host. To elucidate the mechanisms of heat resistance, we analyzed the change of the A. fumigatus proteome during a temperature shift from 30°C to 48°C by 2D-fluorescence difference gel electrophoresis (DIGE. To improve 2D gel image analysis results, protein spot quantitation was optimized by missing value imputation and normalization. Differentially regulated proteins were compared to previously published transcriptome data of A. fumigatus. The study was augmented by bioinformatical analysis of transcription factor binding sites (TFBSs in the promoter region of genes whose corresponding proteins were differentially regulated upon heat shock. Results 91 differentially regulated protein spots, representing 64 different proteins, were identified by mass spectrometry (MS. They showed a continuous up-, down- or an oscillating regulation. Many of the identified proteins were involved in protein folding (chaperones, oxidative stress response, signal transduction, transcription, translation, carbohydrate and nitrogen metabolism. A correlation between alteration of transcript levels and corresponding proteins was detected for half of the differentially regulated proteins. Interestingly, some previously undescribed putative targets for the heat shock regulator Hsf1 were identified. This provides evidence for Hsf1-dependent regulation of mannitol biosynthesis, translation, cytoskeletal dynamics and cell division in A. fumigatus. Furthermore, computational analysis of promoters revealed putative binding sites for an AP-2alpha

  8. Global transcriptome analysis of the heat shock response ofshewanella oneidensis

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Haichun; Wang, Sarah; Liu, Xueduan; Yan, Tinfeng; Wu, Liyou; Alm, Eric; Arkin, Adam P.; Thompson, Dorothea K.; Zhou, Jizhong

    2004-04-30

    Shewanella oneidensis is an important model organism for bioremediation studies because of its diverse respiratory capabilities. However, the genetic basis and regulatory mechanisms underlying the ability of S. oneidensis to survive and adapt to various environmentally relevant stresses is poorly understood. To define this organism's molecular response to elevated growth temperatures, temporal gene expression profiles were examined in cells subjected to heat stress using whole-genome DNA microarrays for S. oneidensis MR-1. Approximately 15 percent (711) of the predicted S. oneidensis genes represented on the microarray were significantly up- or down-regulated (P < 0.05) over a 25-min period following shift to the heat shock temperature (42 C). As expected, the majority of S. oneidensis genes exhibiting homology to known chaperones and heat shock proteins (Hsps) were highly and transiently induced. In addition, a number of predicted genes encoding enzymes in glycolys is and the pentose cycle, [NiFe] dehydrogenase, serine proteases, transcriptional regulators (MerR, LysR, and TetR families), histidine kinases, and hypothetical proteins were induced in response to heat stress. Genes encoding membrane proteins were differentially expressed, suggesting that cells possibly alter their membrane composition or structure in response to variations in growth temperature. A substantial number of the genes encoding ribosomal proteins displayed down-regulated co-expression patterns in response to heat stress, as did genes encoding prophage and flagellar proteins. Finally, based on computational comparative analysis of the upstream promoter regions of S.oneidensis heat-inducible genes, a putative regulatory motif, showing high conservation to the Escherichia coli sigma 32-binding consensus sequence, was identified.

  9. The Response of Dyneema to Shock-Loading

    Science.gov (United States)

    Chapman, David J.; Braithwaite, Christopher H.; Proud, William G.

    2009-12-01

    Dyneema is a registered trademark of a self-reinforced polyethylene (manufactured by DSM) which is showing great promise as a replacement for brittle-fibre-reinforced epoxies in various dynamic applications. As part of an investigation of its high-rate mechanical properties, we have measured the response of Dyneema under the condition of uniaxial strain during shock-loading. Data on the principal-Hugoniot curve was obtained using in-material manganin stress gauges to measure both longitudinal stress and shock-wave velocity. Off-Hugoniot data was generated using a plate-impact reverberation technique, where a Dyneema sample was sandwiched between two higher impedance copper anvils. Manganin stress gauges mounted at the interface between the Dyneema sample and copper anvils monitored the ring-up of stress in the specimen. Finally, the release curve from a given principal-Hugoniot state was measured using a reverse ballistic impact technique where free-surface velocity was measured using VISAR.

  10. Anaphylactic shock: catecholamine actions in the responses to opioid antagonists.

    Science.gov (United States)

    Amir, S

    1988-01-01

    The pathophysiological consequences of endorphin release in anaphylactic shock were investigated through pharmacological studies using opiate antagonists (naloxone, naltrexone, natrexone methyl bromide) as well as agonists (morphine, beta-endorphin). These studies suggest that induction of anaphylaxis provokes the release of endogenous opioids, possibly from the hypothalamus, which contribute to the shock process by stimulating opiate receptors in the CNS. The mechanism of pathophysiologic action of endorphin in anaphylaxis involves, at least in part, inhibition of the central component of the sympatho-adrenalmedullary system. This results in reduced effectiveness of the sympathetic system to physiologically reverse the circulatory effects of the toxic mediators of anaphylaxis. Naloxone, by blocking endorphin action at CNS opiate receptors located at autonomic regulatory centers (e.g. hypothalamus), reverses the sympatho-inhibitory effect of the endorphin peptides. This results in increased central sympathetic outflow to peripheral sympathetic neuroeffector mechanisms; it affords improved sympathetic compensatory responses and increases survival. TRH and DT gamma E physiologically oppose the action of endorphins upon the autonomic system. They stimulate central sympathetic mechanisms through their own receptor systems and increase outflow to peripheral sympathetic effectors. This also results in improved circulatory function and survival.

  11. The shock response of a tape wrapped carbon fiber composite

    Science.gov (United States)

    Wood, David Christopher; Hazell, Paul; Appleby-Thomas, Gareth James; Barnes, Nicholas

    2012-03-01

    Carbon fiber composites are becoming ever more important in the design and construction of vehicles for the aerospace industry. Such vehicles will be subjected to transient loading during their inservice lives. Consequently, it is important to know how carbon fiber composites behave while under shock loading. This study investigates the shock response of a tape wrapped carbon fiber composite with a phenolic resin matrix and with the carbon fiber weave angled perpendicular to the direction of impact. The Hugoniot equation of state was found to be linear and of the form US=3.69+0.59up. Periodic oscillations were observed on many of the traces, attributed to interactions between the various layers of the composite. Further, a Hugoniot elastic limit of 1.39 ± 0.19 GPa was found. Finally, embedded lateral stress gauges indicated that at low pressures (< 5 GPa), lateral stresses in the composite were comparable to what would be expected in the matrix material alone, e.g. the lateral behaviour was highly dependent on the phenolic resin.

  12. Submerged culture mycelium and broth of Grifola frondosa improve glycemic responses in diabetic rats.

    Science.gov (United States)

    Lo, Hui-Chen; Hsu, Tai-Hao; Chen, Ching-Yi

    2008-01-01

    Grifola frondosa, an edible fungus with a large fruiting body and overlapping caps, has been demonstrated to be a natural source of health-promoting substances, mainly due to its polysaccharides beta-glucan. By using male Wistar rats injected with saline (normal rats) or nicotinamide plus streptozotocin (diabetic rats), we investigated the effects of an orally ingested placebo (CON and STZ groups), culture mycelium (CGM and SGM groups), broth (CGB and SGB groups), and mycelium plus broth (CGX and SGX groups) of Grifola frondosa on glycemic responses. During the experimental period (from day 0 to day 15), the STZ group had significantly lower body weight compared to the CON group (one-way ANOVA, pGrifola frondosa have bioactivities for improving glycemic responses.

  13. Comparison of Shock Response Spectrum for Different Gun Tests

    Directory of Open Access Journals (Sweden)

    J.A. Cordes

    2013-01-01

    Full Text Available The Soft Catch Gun at Picatinny Arsenal is regularly used for component testing. Most shots contain accelerometers which record accelerations as a function of time. Statistics of accelerometer data indicate that the muzzle exit accelerations are, on average, higher than tactical firings. For that reason, Soft Catch Gun tests with unusually high accelerations may not be scored for Lot Acceptance Tests (LAT by some customers. The 95/50 Normal Tolerance Limit (NTL is proposed as a means of determining which test results should be scored. This paper presents comparisons of Shock Response Spectra (SRS used for the 95/50 scoring criteria. The paper also provides a Discussion Section outlining some concerns with scoring LAT results based on test results outside of the proposed 95/50 criteria.

  14. Understanding pyrotechnic shock dynamics and response attenuation over distance

    Science.gov (United States)

    Ott, Richard J.

    Pyrotechnic shock events used during stage separation on rocket vehicles produce high amplitude short duration structural response that can lead to malfunction or degradation of electronic components, cracks and fractures in brittle materials, local plastic deformation, and can cause materials to experience accelerated fatigue life. These transient loads propagate as waves through the structural media losing energy as they travel outward from the source. This work assessed available test data in an effort to better understand attenuation characteristics associated with wave propagation and attempted to update a historical standard defined by the Martin Marietta Corporation in the late 1960's using out of date data acquisition systems. Two data sets were available for consideration. The first data set came from a test that used a flight like cylinder used in NASA's Ares I-X program, and the second from a test conducted with a flat plate. Both data sets suggested that the historical standard was not a conservative estimate of shock attenuation with distance, however, the variation in the test data did not lend to recommending an update to the standard. Beyond considering attenuation with distance an effort was made to model the flat plate configuration using finite element analysis. The available flat plate data consisted of three groups of tests, each with a unique charge density linear shape charge (LSC) used to cut an aluminum plate. The model was tuned to a representative test using the lowest charge density LSC as input. The correlated model was then used to predict the other two cases by linearly scaling the input load based on the relative difference in charge density. The resulting model predictions were then compared with available empirical data. Aside from differences in amplitude due to nonlinearities associated with scaling the charge density of the LSC, the model predictions matched the available test data reasonably well. Finally, modeling best

  15. Growth and physiological responses of submerged plant Vallisneria natans to water column ammonia nitrogen and sediment copper

    Directory of Open Access Journals (Sweden)

    Zhengjie Zhu

    2016-04-01

    Full Text Available Background. The decline of submerged plant populations due to high heavy metal (e.g., Cu levels in sediments and ammonia nitrogen (ammonia-N accumulation in the freshwater column has become a significant global problem. Previous studies have evaluated the effect of ammonia-N on submerged macrophytes, but few have focused on the influence of sediment Cu on submerged macrophytes and their combined effects. Methods. In this paper, we selected three levels of ammonia-N (0, 3, and 6 mg L−1 and sediment Cu (25.75 ± 6.02 as the control, 125.75 ± 6.02, and 225.75 ± 6.02 mg kg−1, to investigate the influence of sediment Cu and ammonia-N on submerged Vallisneria natans. We measured the relative growth rate (RGR, above- and below- ground biomass, chlorophyll, non-protein thiol (NP-SH, and free proline. Results and Discussion. The below-ground biomass of V. natans decreased with increasing Cu sediment levels, suggesting that excessive sediment Cu can result in significant damage to the root of V. natans. Similarly, the above-ground biomass significantly decreased with increasing ammonia-N concentrations, indicating that excessive water ammonia-N can cause significant toxicity to the leaf of V. natans. In addition, high ammonia-N levels place a greater stress on submerged plants than sediment Cu, which is indicated by the decline of RGR and chlorophyll, and the increase of (NP-SH and free proline. Furthermore, high sediment Cu causes ammonia-N to impose greater injury on submerged plants, and higher sediment Cu levels (Cu ≥ 125.75 mg kg−1 led to the tolerant values of ammonia-N for V. natans decreasing from 6 to 3 mg L−1. This study suggests that high sediment Cu restricts the growth of plants and intensifies ammonia-N damage to V. natans.

  16. Highly trabeculated structure of the human endocardium underlies asymmetrical response to low-energy monophasic shocks

    Science.gov (United States)

    Connolly, Adam; Robson, Matthew D.; Schneider, Jürgen; Burton, Rebecca; Plank, Gernot; Bishop, Martin J.

    2017-09-01

    Novel low-energy defibrillation therapies are thought to be driven by virtual-electrodes (VEs), due to the interaction of applied monophasic electric shocks with fine-scale anatomical structures within the heart. Significant inter-species differences in the cardiac (micro)-anatomy exist, however, particularly with respect to the degree of endocardial trabeculations, which may underlie important differences in response to low-energy defibrillation protocols. Understanding the interaction of monophasic electric fields with the specific human micro-anatomy is therefore imperative in facilitating the translation and optimisation of these promising experimental therapies to the clinic. In this study, we sought to investigate how electric fields from implanted devices interact with the highly trabeculated human endocardial surface to better understand shock success in order to help optimise future clinical protocols. A bi-ventricular human computational model was constructed from high resolution (350 μm) ex-vivo MR data, including anatomically accurate endocardial structures. Monophasic shocks were applied between a basal right ventricular catheter and an exterior ground. Shocks of varying strengths were applied with both anodal [positive right ventricle (RV) electrode] and cathodal (negative RV electrode) polarities at different states of tissue refractoriness and during induced arrhythmias. Anodal shocks induced isolated positive VEs at the distal side of "detached" trabeculations, which rapidly spread into hyperpolarised tissue on the surrounding endocardial surfaces following the shock. Anodal shocks thus depolarised more tissue 10 ms after the shock than cathodal shocks where the propagation of activation from VEs induced on the proximal side of "detached" trabeculations was prevented due to refractory endocardium. Anodal shocks increased arrhythmia complexity more than cathodal shocks during failed anti-arrhythmia shocks. In conclusion, multiple detached

  17. Response and function of skeletal muscle heat shock protein 70.

    Science.gov (United States)

    Liu, Yuefei; Gampert, Larissa; Nething, Katja; Steinacker, Jürgen M

    2006-09-01

    In response to stress, cells produce a series of heat shock proteins (Hsps). One of the most prominent Hsps, is the 70 kDa Hsp (Hsp70). Hsp70 is a highly conserved and essential protein against stress. The skeletal muscle responds to a diverse group of stress signals namely, muscle contraction linked energy and milieu challenges, ischemia and exercise by producing Hsp70. The extent of this Hsp70 response in skeletal muscle depends on the type and intensity of the signal, and is characterized in a muscle fiber specific manner by a special time course. Hsp70 in the skeletal muscle is regulated at transcriptional, translational and posttranslational levels. Hsp70 serves as an indicator for cellular stress as a molecular chaperone, plays pivotal role in maintaining cellular homeostasis by preventing apoptosis, influences energy metabolism, facilitates cellular processes in terms of muscular adaptation and interacts with other signalling pathways. This review summarizes our current knowledge on the skeletal muscle Hsp70 response.

  18. US State Submerged Lands

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Submerged Lands Act (43 U.S.C. Section 1301 et seq.) grants coastal states title to natural resources located within their coastal submerged lands and navigable...

  19. Metastable Features of Economic Networks and Responses to Exogenous Shocks.

    Directory of Open Access Journals (Sweden)

    Ali Hosseiny

    Full Text Available It is well known that a network structure plays an important role in addressing a collective behavior. In this paper we study a network of firms and corporations for addressing metastable features in an Ising based model. In our model we observe that if in a recession the government imposes a demand shock to stimulate the network, metastable features shape its response. Actually we find that there exists a minimum bound where any demand shock with a size below it is unable to trigger the market out of recession. We then investigate the impact of network characteristics on this minimum bound. We surprisingly observe that in a Watts-Strogatz network, although the minimum bound depends on the average of the degrees, when translated into the language of economics, such a bound is independent of the average degrees. This bound is about 0.44ΔGDP, where ΔGDP is the gap of GDP between recession and expansion. We examine our suggestions for the cases of the United States and the European Union in the recent recession, and compare them with the imposed stimulations. While the stimulation in the US has been above our threshold, in the EU it has been far below our threshold. Beside providing a minimum bound for a successful stimulation, our study on the metastable features suggests that in the time of crisis there is a "golden time passage" in which the minimum bound for successful stimulation can be much lower. Hence, our study strongly suggests stimulations to arise within this time passage.

  20. Submergence-induced morphological, anatomical, and biochemical responses in a terrestrial species affect gas diffusion resistance and photosynthetic performance

    NARCIS (Netherlands)

    Mommer, L; Pons, TL; Wolters-Arts, M; Venema, JH; Visser, EJW

    Gas exchange between the plant and the environment is severely hampered when plants are submerged, leading to oxygen and energy deficits. A straightforward way to reduce these shortages of oxygen and carbohydrates would be continued photosynthesis under water, but this possibility has received only

  1. Algae mediate submerged macrophyte response to nutrient and dissolved inorganic carbon loading: a mesocosm study on different species.

    Science.gov (United States)

    Xie, Dong; Yu, Dan; You, Wen-Hua; Wang, Li-Gong

    2013-10-01

    Nutrient and dissolved inorganic carbon are two important factors that influence the development and species composition of submerged macrophyte communities in shallow lake ecosystems. Yet little is known about their potential interactive effects on the submerged macrophytes and competition outcome of macrophyte-phytoplankton. We performed a mesocosm experiment to investigate the growth and photosynthetic performance of three submerged macrophytes in relation to phytoplankton/epiphyton with nutrient and bicarbonate enrichment. During the experimental period (42 d), increase in nutrient loading in water column resulted in a substantial burst of phytoplankton and epiphyton growth and increased light attenuation. When combined with nutrient loading, bicarbonate enrichment also resulted in a heavily phytoplankton- and epiphyton-dominated state, although bicarbonate enrichment per se does not cause the phytoplankton and epiphyton growth. However, increase in nutrient loading in water column had significant negative impact on individual performances (growth and photosynthesis) of the three submerged macrophytes and bicarbonate enrichment increased the effect of eutrophication on two dissected-leaf macrophytes (M. spicatum and E. nuttallii). Furthermore, our results also suggest that species-specific photosynthetic performances occurred when submerged macrophytes in an environment with high abundance of phytoplankton/epiphyton. This study highlighted that increase in nutrient loading and bicarbonate in water column is likely to interactively impact both abiotic and biotic properties of a freshwater ecosystem. The interactions of these two factors could select macrophyte species that are able to resist the shading from phytoplankton/epiphyton, making these species more dominant in natural freshwater ecosystems. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. A minimal titration modelization of the mammalian dynamical heat shock response

    CERN Document Server

    Aude, Sivéry; Thommen, Quentin

    2015-01-01

    Environmental stress, such as oxidative or heat stress, induces the activation of the Heat Shock Response (HSR) which leads to an increase in the heat shock proteins (HSPs) level. These HSPs act as molecular chaperones to maintain proteostasis. Even if the main heat shock response partners are well known, a detailed description of the dynamical properties of the HSR network is still missing. In this study, we derive a minimal mathematical model of cellular response to heat shock that reproduces available experimental data sets both on transcription factor activity and cell viability. This simplistic model highlights the key mechanistic processes that rule the HSR network and reveals (i) the titration of Heat Shock Factor 1 (HSF1) by chaperones as the guiding line of the network, (ii) that protein triage governs the fate of damaged proteins and (iii) three different temperature regimes describing normal, acute or chronic stress.

  3. Identification of genes involved in cold-shock response in rainbow ...

    Indian Academy of Sciences (India)

    Andreas Borchel

    2017-08-30

    Aug 30, 2017 ... inducible, alpha (gadd45a) and sclerostin domain-containing protein 1 (sostdc1) were upregulated in the liver upon cold shock in two different rainbow trout strains, suggesting that these genes may be considered as general biomarkers for cold shock in rainbow trout. Keywords. stress response; fibroblast ...

  4. Invasive submerged freshwater macrophytes are more plastic in their response to light intensity than to the availability of free CO2 in air-equilibrated water

    DEFF Research Database (Denmark)

    Eller, Franziska; Alnoee, Anette B.; Boderskov, Teis

    2015-01-01

    1. The future increase in the atmospheric CO2 concentration is likely to affect the growth and performance of submerged freshwater macrophytes because of higher concentrations of free CO2 in the water at air equilibrium. We measured the plastic responses to free CO2 and light for several traits...... of four invasive aquatic plants (Elodea canadensis, Egeria densa, Hydrilla verticillata and Ceratophyllum demersum) that use bicarbonate. 2. The plants were grown in standard culture media at either high (HiC, c. 50 lmol L 1) or low concentrations of free CO2 (LowC, c. 19 lmol L 1) combined with high (Hi...

  5. EXPERIMENTAL EVALUATION OF SHOCK SPECTRUM RESPONSE OF ROLLING STOCK

    National Research Council Canada - National Science Library

    A. V. Tretiakov; O. A. Tretiakov; M. V. Zimakova; A. A. Petrov

    2017-01-01

    Purpose. The article is aimed to analyze the increase in the effectiveness of traditional methods for carrying out shock tests of land vehicles, in order to assess their strength, reliability and durability. Methodology...

  6. Three essays on monetary policy responses to oil price shocks

    Science.gov (United States)

    Plante, Michael

    This dissertation contains three chapters which explore the question of how monetary policy should respond to changes in the price of oil. Each chapter explores the question from the perspective of a different economic environment. The first chapter examines welfare maximizing optimal monetary policy in a closed economy New Keynesian model that is extended to include household and firm demand for oil products, sticky wages, and capital accumulation. When households and firms demand oil products a natural difference arises between the Consumer Price Index (CPI), the core CPI, and the GDP deflator. I show that when nominal wages are flexible then the optimal policy places a heavy emphasis on stabilizing the inflation rate of the core CPI. If aggregate nominal wages are sticky then the central bank should focus on stabilizing some combination of core inflation and nominal wage inflation. Under no case examined is it optimal to stabilize either GDP deflator or CPI inflation. The second chapter examines monetary policy responses to oil price shocks in a small open economy with traded and non-traded goods. Oil and labor are used to produce the traded and non-traded goods and prices are sticky in the non-traded sector. I show analytically that the ratio of the oil and labor cost shares in the traded and non-traded sectors is crucial for determining the dynamic behavior of many macroeconomic variables after a rise in the price of oil. A policy of fixed exchange rates can produce higher or lower inflation in the non-traded sector depending upon the ratio. Likewise, a policy that stabilizes the inflation rate of prices in the non-traded sector can cause the nominal exchange rate to appreciate or depreciate. For the proper calibration, a policy that stabilizes core inflation produces results very close to the one that stabilizes non-traded inflation. Analytical results show that the fixed exchange rate always produces a unique solution. The policy of stabilizing non

  7. Response of ocean bottom dwellers exposed to underwater shock waves

    Science.gov (United States)

    Hosseini, S. H. R.; Kaiho, Kunio; Takayama, Kazuyoshi

    2016-01-01

    The paper reports results of experiments to estimate the mortality of ocean bottom dwellers, ostracoda, against underwater shock wave exposures. This study is motivated to verify the possible survival of ocean bottom dwellers, foraminifera, from the devastating underwater shock waves induced mass extinction of marine creatures which took place at giant asteroid impact events. Ocean bottom dwellers under study were ostracoda, the replacement of foraminifera, we readily sampled from ocean bottoms. An analogue experiment was performed on a laboratory scale to estimate the domain and boundary of over-pressures at which marine creatures' mortality occurs. Ostracods were exposed to underwater shock waves generated by the explosion of 100mg PETN pellets in a chamber at shock over-pressures ranging up to 44MPa. Pressure histories were measured simultaneously on 113 samples. We found that bottom dwellers were distinctively killed against overpressures of 12MPa and this value is much higher than the usual shock over-pressure threshold value for marine-creatures having lungs and balloons.

  8. Restoration of Shallow Lakes in Subtropical and Tropical China: Response of Nutrients and Water Clarity to Biomanipulation by Fish Removal and Submerged Plant Transplantation

    Directory of Open Access Journals (Sweden)

    Jinlei Yu

    2016-10-01

    Full Text Available Fish removal has been used to restore temperate lakes, and positive effects on ecological state and water clarity have frequently been recorded in many lakes. Recently, a supplementary measure, transplantation of submerged macrophytes after fish removal, has been applied to restore warm Chinese shallow lakes in order to compensate for the expected lack of increasing grazing control of phytoplankton after the biomanipulation. These measures have successfully shifted turbid warm lakes to a clear water state, but little is known about the responses to restoration of key physico-chemical variables. We analyzed the seasonal variation in nutrient concentrations in two subtropical and one tropical biomanipulated shallow Chinese lakes subjected to restoration. In all three lakes, a marked decline occurred in the concentrations of lake total nitrogen (TN, total phosphorus (TP, total suspended solids (TSS, and chlorophyll a (Chl a, while the transparency (SD:WD ratio, Secchi depth to water depth ratio increased. A clear water state was established, lasting so far for 7 to 23 months, and TN, TP, Chl a, and TSS levels in the three restored lakes decreased to, on average, 49%, 58%, 41%, and 18% of the level prior to restoration and/or the level in a reference lake, respectively, while the annual mean SD:WD ratio exhibited a 1.5–4 fold increase. In conclusion, lake restoration by transplantation of submerged macrophytes after fish removal had major positive effects on the physico-chemical variables in our study lakes. However, continuous control of omnivorous and herbivorous fish biomass is recommended as the fish typically present in warm, shallow lakes to some extent feed on submerged macrophytes, when available.

  9. Evaluating the Mechanism of Oil Price Shocks and Fiscal Policy Responses in the Malaysian Economy

    Science.gov (United States)

    Bekhet, Hussain A.; Yusoff, Nora Yusma Mohamed

    2013-06-01

    The paper aims to explore the symmetric impact of oil price shock on economy, to understand its mechanism channel and how fiscal policy response towards it. The Generalized Impulse Response Function and Variance Decomposition under the VAR methodology were employed. The empirical findings suggest that symmetric oil price shock has a positive and direct impact on oil revenue and government expenditure. However, the real GDP is vulnerable in a short-term but not in the long term period. These results would confirm that fiscal policy is the main mechanism channel that mitigates the adverse effects oil price shocks to the economy.

  10. Control and regulation of the cellular responses to cold shock: the responses in yeast and mammalian systems

    National Research Council Canada - National Science Library

    Al-Fageeh, Mohamed B; Smales, C Mark

    2006-01-01

    Although the cold-shock response has now been studied in a number of different organisms for several decades, it is only in the last few years that we have begun to understand the molecular mechanisms...

  11. HSF1 and HSF3 cooperatively regulate the heat shock response in lizards.

    Directory of Open Access Journals (Sweden)

    Ryosuke Takii

    Full Text Available Cells cope with temperature elevations, which cause protein misfolding, by expressing heat shock proteins (HSPs. This adaptive response is called the heat shock response (HSR, and it is regulated mainly by heat shock transcription factor (HSF. Among the four HSF family members in vertebrates, HSF1 is a master regulator of HSP expression during proteotoxic stress including heat shock in mammals, whereas HSF3 is required for the HSR in birds. To examine whether only one of the HSF family members possesses the potential to induce the HSR in vertebrate animals, we isolated cDNA clones encoding lizard and frog HSF genes. The reconstructed phylogenetic tree of vertebrate HSFs demonstrated that HSF3 in one species is unrelated with that in other species. We found that the DNA-binding activity of both HSF1 and HSF3 in lizard and frog cells was induced in response to heat shock. Unexpectedly, overexpression of lizard and frog HSF3 as well as HSF1 induced HSP70 expression in mouse cells during heat shock, indicating that the two factors have the potential to induce the HSR. Furthermore, knockdown of either HSF3 or HSF1 markedly reduced HSP70 induction in lizard cells and resistance to heat shock. These results demonstrated that HSF1 and HSF3 cooperatively regulate the HSR at least in lizards, and suggest complex mechanisms of the HSR in lizards as well as frogs.

  12. Predicting The Fragility Of Renal Calculi In Response To Shock ...

    African Journals Online (AJOL)

    ray film of the kidneys, ureters and bladder (KUB) area as predictors of stone fragility during shock wave lithotripsy (SWL). Patients and Methods: This prospective study included 336 patients who had a single renal pelvic stone .20 mm and ...

  13. Underwater shock response analysis of a floating cylinder

    NARCIS (Netherlands)

    Aanhold, J.E. van; Vaders, J.A.A.; Trouwborst, W.

    2008-01-01

    Three-dimensional simulations were done of a heavy underwater shock trial on a floating cylinder, which was executed in 1996. The analyses were done using the so-called Simplified Interaction Tool, an approximate interaction method developed by TNO as an add-on to LS-DYNA. The analysis was continued

  14. Genomic expression profiling across the pediatric systemic inflammatory response syndrome, sepsis, and septic shock spectrum.

    Science.gov (United States)

    Wong, Hector R; Cvijanovich, Natalie; Allen, Geoffrey L; Lin, Richard; Anas, Nick; Meyer, Keith; Freishtat, Robert J; Monaco, Marie; Odoms, Kelli; Sakthivel, Bhuvaneswari; Shanley, Thomas P

    2009-05-01

    To advance our biological understanding of pediatric septic shock, we measured the genome-level expression profiles of critically ill children representing the systemic inflammatory response syndrome (SIRS), sepsis, and septic shock spectrum. Prospective observational study involving microarray-based bioinformatics. Multiple pediatric intensive care units in the United States. Children shock on day 1. The available day 3 samples included 20 patients still meeting sepsis criteria, 39 patients still meeting septic shock criteria, and 24 patients meeting the exclusive day 3 category, SIRS resolved. None other than standard care. Longitudinal analyses were focused on gene expression relative to control samples and patients having paired day 1 and day 3 samples. The longitudinal analysis focused on up-regulated genes revealed common patterns of up-regulated gene expression, primarily corresponding to inflammation and innate immunity, across all patient groups on day 1. These patterns of up-regulated gene expression persisted on day 3 in patients with septic shock, but not to the same degree in the other patient classes. The longitudinal analysis focused on down-regulated genes demonstrated gene repression corresponding to adaptive immunity-specific signaling pathways and was most prominent in patients with septic shock on days 1 and 3. Gene network analyses based on direct comparisons across the SIRS, sepsis, and septic shock spectrum, and all available patients in the database, demonstrated unique repression of gene networks in patients with septic shock corresponding to major histocompatibility complex antigen presentation. Finally, analyses focused on repression of genes corresponding to zinc-related biology demonstrated that this pattern of gene repression is unique to patients with septic shock. Although some common patterns of gene expression exist across the pediatric SIRS, sepsis, and septic shock spectrum, septic shock is particularly characterized by

  15. Non-Specific Protein Modifications by a Phytochemical Induce Heat Shock Response for Self-Defense

    Science.gov (United States)

    Ohnishi, Kohta; Ohkura, Shinya; Nakahata, Erina; Ishisaka, Akari; Kawai, Yoshichika; Terao, Junji; Mori, Taiki; Ishii, Takeshi; Nakayama, Tsutomu; Kioka, Noriyuki; Matsumoto, Shinya; Ikeda, Yasutaka; Akiyama, Minoru; Irie, Kazuhiro; Murakami, Akira

    2013-01-01

    Accumulated evidence shows that some phytochemicals provide beneficial effects for human health. Recently, a number of mechanistic studies have revealed that direct interactions between phytochemicals and functional proteins play significant roles in exhibiting their bioactivities. However, their binding selectivities to biological molecules are considered to be lower due to their small and simple structures. In this study, we found that zerumbone, a bioactive sesquiterpene, binds to numerous proteins with little selectivity. Similar to heat-denatured proteins, zerumbone-modified proteins were recognized by heat shock protein 90, a constitutive molecular chaperone, leading to heat shock factor 1-dependent heat shock protein induction in hepa1c1c7 mouse hepatoma cells. Furthermore, oral administration of this phytochemical up-regulated heat shock protein expressions in the livers of Sprague-Dawley rats. Interestingly, pretreatment with zerumbone conferred a thermoresistant phenotype to hepa1c1c7 cells as well as to the nematode Caenorhabditis elegans. It is also important to note that several phytochemicals with higher hydrophobicity or electrophilicity, including phenethyl isothiocyanate and curcumin, markedly induced heat shock proteins, whereas most of the tested nutrients did not. These results suggest that non-specific protein modifications by xenobiotic phytochemicals cause mild proteostress, thereby inducing heat shock response and leading to potentiation of protein quality control systems. We considered these bioactivities to be xenohormesis, an adaptation mechanism against xenobiotic chemical stresses. Heat shock response by phytochemicals may be a fundamental mechanism underlying their various bioactivities. PMID:23536805

  16. Improved fast response pressure gauge for shock reflection studies in ionized gases.

    Science.gov (United States)

    Hanson, R. K.; Baganoff, D.

    1972-01-01

    An improved design is presented for a fast response pressure gauge (0.1 microsec risetime) suitable for short duration measurements on the end wall of a shock tube. The design includes standard components to facilitate gauge construction, and it utilizes dual capacitive sensing elements together with a signal differencing scheme to permit use of the gauge in ionized gases. Pressure-time records obtained with the gauge are presented showing details of pressure profiles on the shock tube end wall for reflecting shock waves in ionized gases.

  17. In-Axis and Cross-Axid Accelerometer Response in Shock Environments

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, V.I.; Brown, F.A.

    1999-03-10

    The characteristics of a piezoresistive accelerometer in shock environments have been studied at Sandia National Laboratories (SNL) in the Mechanical Shock Testing Laboratory for ten years The SNL Shock Laboratory has developed a capability to characterize accelerometers and other transducers with shocks aligned with the transducer's sensing axis and perpendicular to the transducer's sensing axis. This unique capability includes Hopkinson bars made of aluminum, steel, titanium, and beryllium. The bars are configured as both single and split Hopkinson bars. Four different areas that conclude this study are summarized in this paper: characterization of the cross-axis response of the accelerometer in the four environments of static compression, static strain on a beam, dynamic strain, and mechanical shock, the accelerometer's response on a titanium Hopkinson bar with two 45{degree} flats on the end of the bar; failure analysis of the accelerometer; and measurement of the accelerometer's self-generating cable response in a shock environment.

  18. Properties of post-shock solar wind deduced from geomagnetic indices responses after sudden impulses

    CERN Document Server

    Li, Hui

    2016-01-01

    Interplanetary (IP) shock plays a key role in causing the global dynamic changes of the geospace environment. For the perspective of Solar-Terrestrial relationship, it will be of great importance to estimate the properties of post-shock solar wind simply and accurately. Motivated by this, we performed a statistical analysis of IP shocks during 1998-2008, focusing on the significantly different responses of two well-used geomagnetic indices (SYMH and AL) to the passive of two types of IP shocks. For the IP shocks with northward IMF (91 cases), the SYMH index keeps on the high level after the sudden impulses (SI) for a long time. Meanwhile, the change of AL index is relative small, with an mean value of only -29 nT. However, for the IP shocks with southward IMF (92 cases), the SYMH index suddenly decreases at a certain rate after SI, and the change of AL index is much significant, of -316 nT. Furthermore, the change rate of SYMH index after SI is found to be linearly correlated with the post-shock reconnection ...

  19. Mechanism of protonophores-mediated induction of heat-shock response in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Saha Swati

    2009-01-01

    Full Text Available Abstract Background Protonophores are the agents that dissipate the proton-motive-force (PMF across E. coli plasma membrane. As the PMF is known to be an energy source for the translocation of membrane and periplasmic proteins after their initial syntheses in cell cytoplasm, protonophores therefore inhibit the translocation phenomenon. In addition, protonophores also induce heat-shock-like stress response in E. coli cell. In this study, our motivation was to investigate that how the protonophores-mediated phenomena like inhibition of protein translocation and induction of heat-shock proteins in E. coli were correlated. Results Induction of heat-shock-like response in E. coli attained the maximum level after about 20 minutes of cell growth in the presence of a protonophore like carbonyl cyanide m-chloro phenylhydrazone (CCCP or 2, 4-dinitrophenol (DNP. With induction, cellular level of the heat-shock regulator protein sigma-32 also increased. The increase in sigma-32 level was resulted solely from its stabilization, not from its increased synthesis. On the other hand, the protonophores inhibited the translocation of the periplasmic protein alkaline phosphatase (AP, resulting its accumulation in cell cytosol partly in aggregated and partly in dispersed form. On further cell growth, after withdrawal of the protonophores, the previously accumulated AP could not be translocated out; instead the AP-aggregate had been degraded perhaps by an induced heat-shock protease ClpP. Moreover, the non-translocated AP formed binary complex with the induced heat-shock chaperone DnaK and the excess cellular concentration of DnaK disallowed the induction of heat-shock response by the protonophores. Conclusion Our experimental results suggested that the protonophores-mediated accumulation and aggregation of membrane proteins (like AP in cell cytosol had signaled the induction of heat-shock proteins in E. coli and the non-translocated protein aggregates were possibly

  20. The shock and spall response of AA 7010-T7651

    Science.gov (United States)

    Hazell, Paul; Appleby-Thomas, Gareth; Wood, David; Painter, Jonathan

    2013-06-01

    Aluminium alloys are used extensively in armour. Their use as armour materials is primarily due to their relatively low densities and their high strength characteristics. The aerospace-grade 7000-series alloy Al7010-T7651 is one possible contender for armour. In this study a series of plate-impact experiments were undertaken to investigate the behaviour of this alloy under shock. Manganin stress gauges and a heterodyne velocimeter system were used to interrogate both strength and dynamic tensile failure (spall) respectively; with microscopic analysis of recovered samples providing insight into the development of failure in the material.

  1. Influence of Shock-Wave Profile Shape (``Taylor-Wave'' versus Square-Topped) on the Shock-Hardening and Spallation Response of 316L Stainless Steel

    Science.gov (United States)

    Gray, G. T.; Bourne, N. K.; Millett, J. C. F.; Lopez, M. F.

    2004-07-01

    While much has been learned over the past five decades concerning shock hardening and the spallation response of materials shock-loaded using "square-topped" shock profiles, achieved via flyer plate loading, considerably less quantitative information is known concerning direct in-contact HE-driven or triangular-wave loading profile shock prestraining on metals and alloys. In this paper the influence of shock-wave profile, using both "square-topped" and triangular-wave pulses, on the shock hardening and spallation response of 316L stainless steel is presented. The shock hardening in 316L SS, using a triangular-shaped pulse and square-topped pulse (pulse duration of 0.75 μsec) to a peak shock pressure of 6.6 GPa was found to be reasonably similar. Square-wave loading at 6.6 GPa is observed to result in incipient spallation in 316L SS while triangular-wave loading to an equivalent peak stress is quantified to exhibit no wave-profile "pull-back" nor damage evolution.

  2. CHARADE: A characteristic code for calculating rate-dependent shock-wave response

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.N.; Tonks, D.L.

    1991-01-01

    In this report we apply spatially one-dimensional methods and simple shock-tracking techniques to the solution of rate-dependent material response under flat-plate-impact conditions. This method of solution eliminates potential confusion of material dissipation with artificial dissipative effects inherent in finite-difference codes, and thus lends itself to accurate calculation of elastic-plastic deformation, shock-to-detonation transition in solid explosives, and shock-induced structural phase transformation. Equations are presented for rate-dependent thermoelastic-plastic deformation for (100) planar shock-wave propagation in materials of cubic symmetry (or higher). Specific numerical calculations are presented for polycrystalline copper using the mechanical threshold stress model of Follansbee and Kocks with transition to dislocation drag. A listing of the CHARADE (for characteristic rate dependence) code and sample input deck are given. 26 refs., 11 figs.

  3. Dynamic response of the Martian ionosphere to an interplanetary shock: Mars Express and MAVEN observations

    Science.gov (United States)

    Harada, Y.; Gurnett, D. A.; Kopf, A. J.; Halekas, J. S.; Ruhunusiri, S.; Lee, C. O.; Hara, T.; Espley, J.; DiBraccio, G. A.; Mitchell, D. L.; Mazelle, C.; Larson, D. E.; Jakosky, B. M.

    2017-09-01

    Multipoint observations from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument on board Mars Express and the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission reveal a dynamic response of the Martian ionosphere to abrupt variations in the upstream solar wind plasma. On 2 February 2017, MAVEN, located upstream from the Martian bow shock, encountered a corotating interaction region-related interplanetary shock with a sudden enhancement in the dynamic pressure. MARSIS, operating in the upper ionosphere at ˜478 km altitudes and ˜78° solar zenith angles, observed a sharp increase in the local magnetic field magnitude ˜1 min after the shock passage at MAVEN. The time lag is roughly consistent with the expected propagation time of a pressure pulse from the bow shock to the upper ionosphere at the fast magnetosonic speed. Subsequently, remote soundings recorded disturbed signatures of the topside ionosphere below Mars Express.

  4. Limiting Performance Analysis of Underwater Shock Isolation of a System with Biodynamic Response Using Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    Z. Zong

    2000-01-01

    Full Text Available Biodynamic response of shipboard crew to underwater shock is of a major concern to navies. An underwater shock can produce very high accelerations, resulting in severe human injuries aboard a battleship. Protection of human bodies from underwater shock is implemented by installing onboard isolators. In this paper, the optimal underwater shock isolation to protect human bodies is studied. A simple shock-structure-isolator-human interaction model is first constructed. The model incorporates the effect of fluid-structure interaction, biodynamic response of human body, isolator influence. Based on this model, the optimum shock isolation is then formulated. The performance index and restriction are defined. Thirdly, GA (genetic algorithm is employed to solve the formulated optimization problem. GA is a powerful evolutionary optimization scheme suitable for large-scale and multi-variable optimization problems that are otherwise hard to be solved by conventional methods. A brief introduction to GA is given in the paper. Finally, the method is applied to an example problem and the limiting performance characteristic is obtained.

  5. Shock Compression Response of Calcium Fluoride (CaF2)

    Science.gov (United States)

    Root, Seth

    2017-06-01

    The fluorite crystal structure is a textbook lattice that is observed for many systems, such as CaF2, Mg2 Si, and CeO2. Specifically, CaF2 is a useful material for studying the fluorite system because it is readily available as a single crystal. Under static compression, CaF2 is known to have at least three solid phases: fluorite, cotunnite, and a Ni2 In phase. Along the Hugoniot CaF2 undergoes a fluorite to cotunnite phase transition, however, at higher shock pressures it is unknown whether CaF2 undergoes another solid phase transition or melts directly from the cotunnite phase. In this work, we conducted planar shock compression experiments on CaF2 using Sandia's Z-machine and a two-stage light gun up to 900 GPa. In addition, we use density functional theory (DFT) based quantum molecular dynamics (QMD) simulations to provide insight into the CaF2 state along the Hugoniot. In collaboration with: Michael Desjarlais, Ray Lemke, Patricia Kalita, Scott Alexander, Sandia National Laboratories. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL850.

  6. Management of the endoplasmic reticulum stress by activation of the heat shock response in yeast

    DEFF Research Database (Denmark)

    Hou, Jin; Tang, Hongting; Liu, Zihe

    2014-01-01

    In yeast Saccharomyces cerevisiae, accumulation of misfolded proteins in the endoplasmic reticulum (ER) causes ER stress and activates the unfolded protein response (UPR), which is mediated by Hac1p. The heat shock response (HSR) mediated by Hsf1p, mainly regulates cytosolic processes and protects...

  7. Impaired heat shock response in cells expressing full-length polyglutamine-expanded huntingtin.

    Directory of Open Access Journals (Sweden)

    Sidhartha M Chafekar

    Full Text Available The molecular mechanisms by which polyglutamine (polyQ-expanded huntingtin (Htt causes neurodegeneration in Huntington's disease (HD remain unclear. The malfunction of cellular proteostasis has been suggested as central in HD pathogenesis and also as a target of therapeutic interventions for the treatment of HD. We present results that offer a previously unexplored perspective regarding impaired proteostasis in HD. We find that, under non-stress conditions, the proteostatic capacity of cells expressing full length polyQ-expanded Htt is adequate. Yet, under stress conditions, the presence of polyQ-expanded Htt impairs the heat shock response, a key component of cellular proteostasis. This impaired heat shock response results in a reduced capacity to withstand the damage caused by cellular stress. We demonstrate that in cells expressing polyQ-expanded Htt the levels of heat shock transcription factor 1 (HSF1 are reduced, and, as a consequence, these cells have an impaired a heat shock response. Also, we found reduced HSF1 and HSP70 levels in the striata of HD knock-in mice when compared to wild-type mice. Our results suggests that full length, non-aggregated polyQ-expanded Htt blocks the effective induction of the heat shock response under stress conditions and may thus trigger the accumulation of cellular damage during the course of HD pathogenesis.

  8. Arctigenin from Fructus Arctii is a novel suppressor of heat shock response in mammalian cells

    Science.gov (United States)

    Ishihara, Keiichi; Yamagishi, Nobuyuki; Saito, Youhei; Takasaki, Midori; Konoshima, Takao; Hatayama, Takumi

    2006-01-01

    Because heat shock proteins (Hsps) are involved in protecting cells and in the pathophysiology of diseases such as inflammation, cancer, and neurodegenerative disorders, the use of regulators of the expression of Hsps in mammalian cells seems to be useful as a potential therapeutic modality. To identify compounds that modulate the response to heat shock, we analyzed several natural products using a mammalian cell line containing an hsp promoter-regulated reporter gene. In this study, we found that an extract from Fructus Arctii markedly suppressed the expression of Hsp induced by heat shock. A component of the extract arctigenin, but not the component arctiin, suppressed the response at the level of the activation of heat shock transcription factor, the induction of mRNA, and the synthesis and accumulation of Hsp. Furthermore, arctigenin inhibited the acquisition of thermotolerance in mammalian cells, including cancer cells. Thus, arctigenin seemed to be a new suppressive regulator of heat shock response in mammalian cells, and may be useful for hyperthermia cancer therapy. PMID:16817321

  9. Impacts of climate change on submerged and emergent wetland plants

    Science.gov (United States)

    Frederick T. Short; Sarian Kosten; Pamela A. Morgan; Sparkle L Malone; Gregg E. Moore

    2016-01-01

    Submerged and emergent wetland plant communities are evaluated for their response to global climate change (GCC), focusing on seagrasses, submerged freshwater plants, tidal marsh plants, freshwater marsh plants and mangroves. Similarities and differences are assessed in plant community responses to temperature increase, CO2increase, greater UV-B exposure, sea...

  10. Combining Prognostic and Predictive Enrichment Strategies to Identify Children With Septic Shock Responsive to Corticosteroids.

    Science.gov (United States)

    Wong, Hector R; Atkinson, Sarah J; Cvijanovich, Natalie Z; Anas, Nick; Allen, Geoffrey L; Thomas, Neal J; Bigham, Michael T; Weiss, Scott L; Fitzgerald, Julie C; Checchia, Paul A; Meyer, Keith; Quasney, Michael; Hall, Mark; Gedeit, Rainer; Freishtat, Robert J; Nowak, Jeffrey; Raj, Shekhar S; Gertz, Shira; Lindsell, Christopher J

    2016-10-01

    Prognostic and predictive enrichment strategies are fundamental tools of precision medicine. Identifying children with septic shock who may benefit from corticosteroids remains a challenge. We combined prognostic and predictive strategies to identify a pediatric septic shock subgroup responsive to corticosteroids. We conducted a secondary analysis of 288 previously published pediatric subjects with septic shock. For prognostic enrichment, each study subject was assigned a baseline mortality probability using the pediatric sepsis biomarker risk model. For predictive enrichment, each study subject was allocated to one of two septic shock endotypes, based on a 100-gene signature reflecting adaptive immunity and glucocorticoid receptor signaling. The primary study endpoint was complicated course, defined as the persistence of two or more organ failures at day 7 of septic shock or 28-day mortality. We used logistic regression to test for an association between corticosteroids and complicated course within endotype. Among endotype B subjects at intermediate to high pediatric sepsis biomarker risk model-based risk of mortality, corticosteroids were independently associated with more than a 10-fold reduction in the risk of a complicated course (relative risk, 0.09; 95% CI, 0.01-0.54; p = 0.007). A combination of prognostic and predictive strategies based on serum protein and messenger RNA biomarkers can identify a subgroup of children with septic shock who may be more likely to benefit from corticosteroids. Prospective validation of these strategies and the existence of this subgroup are warranted.

  11. Pro- and anti-inflammatory responses are regulated simultaneously from the first moments of septic shock.

    Science.gov (United States)

    Tamayo, Eduardo; Fernández, Ana; Almansa, Raquel; Carrasco, Elena; Heredia, María; Lajo, Carmen; Goncalves, Lisbeth; Gómez-Herreras, Jose I; de Lejarazu, Raúl Ortiz; Bermejo-Martin, Jesus F

    2011-06-01

    The relationships between cytokine responses in septic shock are currently poorly understood. Some studies have pointed to a biphasic model, with an initial proinflammatory phase, followed by a reactive, anti-inflammatory response to explain the pathogenesis of the most severe form of sepsis. However, evidence for the coexistence of both responses has been found. In this study, the plasma levels of 17 cytokines and chemokines, in 20 patients with septic shock, 11 patients with systemic inflammatory response syndrome (SIRS), during the first 24 hours following diagnosis, and 10 healthy controls, were analyzed and compared. Patients with septic shock showed increased levels of IL-6, IL-8, MCP-1, MIP-1β, IFN-γ, GM-CSF and IL-10 compared to healthy controls. Patients with SIRS showed higher levels of IL-6, IL-8, MCP-1, MIP-1β, G-CSF and IL-10 than controls. Patients with septic shock showed higher levels of IL-8, GM-CSF, MIP-1β than those with SIRS. The Spearman test demonstrated a positive association between the pro-inflammatory mediators IL-6, IL-8, MCP-1, MIP-1β, IFN-γ, GM-CSF and the immunomodulatory cytokine IL-10 in septic shock. Consequently, correlation studies supported the notion that secretion of pro- and anti-inflammatory mediators in septic shock occurs as a simultaneous immune response program initiated early in the course of the disease, revealing that both types of cytokine play a role from the very beginning of this life-threatening condition.

  12. Shock and Release Response of Unreacted Epon 828: Shot 2s-905

    Energy Technology Data Exchange (ETDEWEB)

    Pisa, Matthew Alexander [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fredenburg, David A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dattelbaum, Dana M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lang, John Michael [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sandoval, Donald Leon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-16

    This document summarizes the shock and release response of Epon 828 measured in the dynamic impact experiment 2s-905. Experimentally, a thin Kel-F impactor backed by a low impedance foam impacted an Epon 828 target with embedded electromagnetic gauges. Computationally, a one dimensional simulation of the impact event was performed, and tracer particles were located at the corresponding electromagnetic gauge locations. The experimental configuration was such that the Epon 828 target was initially shocked, and then allowed to release from the high-pressure state. Comparisons of the experimental gauge and computational tracer data were made to assess the performance of equation of state (EOS) 7603, a SESAME EOS for Epon 828, on and off the principal shock Hugoniot. Results indicate that while EOS 7603 can capture the Hugoniot response to better that 1%, while the sound speeds at pressure are under-predicted by 6 - 7%.

  13. Network analysis of oyster transcriptome revealed a cascade of cellular responses during recovery after heat shock.

    Directory of Open Access Journals (Sweden)

    Lingling Zhang

    Full Text Available Oysters, as a major group of marine bivalves, can tolerate a wide range of natural and anthropogenic stressors including heat stress. Recent studies have shown that oysters pretreated with heat shock can result in induced heat tolerance. A systematic study of cellular recovery from heat shock may provide insights into the mechanism of acquired thermal tolerance. In this study, we performed the first network analysis of oyster transcriptome by reanalyzing microarray data from a previous study. Network analysis revealed a cascade of cellular responses during oyster recovery after heat shock and identified responsive gene modules and key genes. Our study demonstrates the power of network analysis in a non-model organism with poor gene annotations, which can lead to new discoveries that go beyond the focus on individual genes.

  14. Inflammatory and Oxidative Stress Responses of an Alveolar Epithelial Cell Line to Airborne Zinc Oxide Nanoparticles at the Air-Liquid Interface: A Comparison with Conventional, Submerged Cell-Culture Conditions

    Directory of Open Access Journals (Sweden)

    Anke-Gabriele Lenz

    2013-01-01

    Full Text Available The biological effects of inhalable nanoparticles have been widely studied in vitro with pulmonary cells cultured under submerged and air-liquid interface (ALI conditions. Submerged exposures are experimentally simpler, but ALI exposures are physiologically more realistic and hence potentially biologically more meaningful. In this study, we investigated the cellular response of human alveolar epithelial-like cells (A549 to airborne agglomerates of zinc oxide (ZnO nanoparticles at the ALI, compared it to the response under submerged culture conditions, and provided a quantitative comparison with the literature data on different types of particles and cells. For ZnO nanoparticle doses of 0.7 and 2.5 μg ZnO/cm2 (or 0.09 and 0.33 cm2 ZnO/cm2, cell viability was not mitigated and no significant effects on the transcript levels of oxidative stress markers (HMOX1, SOD-2 and GCS were observed. However, the transcript levels of proinflammatory markers (IL-8, IL-6, and GM-CSF were induced to higher levels under ALI conditions. This is consistent with the literature data and it suggests that in vitro toxicity screening of nanoparticles with ALI cell culture systems may produce less false negative results than screening with submerged cell cultures. However, the database is currently too scarce to draw a definite conclusion on this issue.

  15. Traumatic shock: the fifth shock.

    Science.gov (United States)

    Anderson, Maighdlin W; Watson, Gregory A

    2013-01-01

    Although, historically, shock associated with traumatic injury has been evaluated through knowledge of the 4 recognized shock patterns--cardiogenic, obstructive, distributive, and hypovolemic--many trauma practitioners view traumatic shock as a unique fifth shock pattern. Although secondary to a systemic inflammatory response syndrome triggered by endogenous danger signals, traumatic shock represents a unique pathological condition that begins with multiple, usually blunt, trauma and may conclude with multiple organ dysfunction syndrome and death. While varying mechanisms of injury may lead to different presentations of shock and cardiovascular decompensation, a unifying theme of traumatic shock is an overwhelming inflammatory response driven by proinflammatory cytokines, and the downstream results of this cytokine storm including, but not limited to, acute respiratory distress syndrome, coagulopathy, sepsis, and multiple organ dysfunction syndrome. Treatment is primarily supportive; however, research into novel therapeutics for traumatic shock is ongoing and promises some direction for future care.

  16. Shock compression response of highly reactive Ni + Al multilayered thin foils

    Science.gov (United States)

    Kelly, Sean C.; Thadhani, Naresh N.

    2016-03-01

    The shock-compression response of Ni + Al multilayered thin foils is investigated using laser-accelerated thin-foil plate-impact experiments over the pressure range of 2 to 11 GPa. The foils contain alternating Ni and Al layers (parallel but not flat) of nominally 50 nm bilayer spacing. The goal is to determine the equation of state and shock-induced reactivity of these highly reactive fully dense thin-foil materials. The laser-accelerated thin-foil impact set-up involved combined use of photon-doppler-velocimetry to monitor the acceleration and impact velocity of an aluminum flyer, and VISAR interferometry was used to monitor the back free-surface velocity of the impacted Ni + Al multilayered target. The shock-compression response of the Ni + Al target foils was determined using experimentally measured parameters and impedance matching approach, with error bars identified considering systematic and experimental errors. Meso-scale CTH shock simulations were performed using real imported microstructures of the cross-sections of the multilayered Ni + Al foils to compute the Hugoniot response (assuming no reaction) for correlation with their experimentally determined equation of state. It was observed that at particle velocities below ˜150 m/s, the experimentally determined equation of state trend matches the CTH-predicted inert response and is consistent with the observed unreacted state of the recovered Ni + Al target foils from this velocity regime. At higher particle velocities, the experimentally determined equation of state deviates from the CTH-predicted inert response. A complete and self-sustained reaction is also seen in targets recovered from experiments performed at these higher particle velocities. The deviation in the measured equation of state, to higher shock speeds and expanded volumes, combined with the observation of complete reaction in the recovered multilayered foils, confirmed via microstructure characterization, is indicative of the occurrence

  17. Submergence tolerance in Hordeum marinum

    DEFF Research Database (Denmark)

    Pedersen, Ole; Malik, Al I.; Colmer, Timothy D.

    2010-01-01

    Floodwaters differ markedly in dissolved CO(2), yet the effects of CO(2) on submergence responses of terrestrial plants have rarely been examined. The influence of dissolved CO(2) on underwater photosynthesis and growth was evaluated for three accessions of the wetland plant Hordeum marinum Huds......) movement, would all contribute to submergence tolerance in H. marinum. The present study demonstrates that dissolved CO(2) levels can determine submergence tolerance of terrestrial plants. So, submergence experiments should be conducted with defined CO(2) concentrations and enrichment might be needed...

  18. Mathematical Modeling of the Heat-Shock Response in HeLa Cells

    Science.gov (United States)

    2015-07-01

    Guisbert, E., D. M. Czyz, ., R. I. Morimoto. 2013. Identification of a tissue-selective heat shock response regulatory network. PLoS Genet . 9...Med. Sci. Sports . 21:742–748. 46. Rakesh, V., J. D. Stallings, ., J. Reifman. 2013. A 3-D mathematical model to identify organ-specific risks in rats

  19. Decelerations and muscle responses during parachute opening shock.

    Science.gov (United States)

    Gladh, Kristofer; Ang, Björn O; Lindholm, Peter; Nilsson, Jenny; Westman, Anton

    2013-11-01

    Pain in the neck region among skydivers can be related to repeated parachute opening shocks (POS), but empirical data on ramair POS biomechanics is lacking in the literature. The aim of this study was to develop and evaluate a methodology for assessment of multidirectional accelerations and neck muscle activity during parachuting, and to describe preliminary data. In an experimental design, four experienced skydivers made two consecutive skydives. Deceleration was recorded with two triaxial accelerometers, one placed on the skydiver's cervicothoracic junction (acc-neck) and the other on the harness (acc-rig). Surface electromyography (EMG) was sampled from four sites bilaterally: anterior-neck, posterior upper and lower neck, and upper shoulder muscles. EMG activity was normalized against a premeasured maximum voluntarily produced electrical signal (MVE). The measuring equipment did not interfere with the parachute jumps. High-quality signals were recorded. The median peak POS deceleration for the acc-neck vs. acc-rig indicated differences (4.0 G vs. 5.1 G), in addition to significant differences emerging for medians of average and maximum onset rates of deceleration (avg: 1.2 G x s(-1) vs. 19.5 G x s(-1); max: 23.0 G x s(-1) vs. 80.0 G x s(-1)). The median of overall muscleactivity was as high as 87% MVE, but no differences in peak activity were found between muscles. Temporal activations of the posterior upper neck occurred less than 50 ms after deceleration initiation, indicating feedforward control of the neck. All instruments recorded data of good quality without impeding the skydiving activity. Triaxial accelerometry on the neck vs. the harness yielded dissimilar results, underlining the importance of correct accelerometer placement. Muscle activity was high during POS and neck muscles showed anticipatory tendencies.

  20. Analysis of DNA-damage response to ionizing radiation in serum-shock synchronized human fibroblasts

    OpenAIRE

    Corra', Samantha; Salvadori, Riccardo; Bee, Leonardo; Barbieri, Vito; Mognato, Maddalena

    2017-01-01

    Many aspects of cellular physiology, including cellular response to genotoxic stress, are related to the circadian rhythmicity induced by the molecular clock. The current study investigated if the cellular response to DNA damage is in relation to endogenous expression levels of the PER2 protein, a key component of the molecular regulatory system that confers rhythmicity in mammalian cells. Human normal fibroblasts (CCD-34Lu) were subjected to serum shock to induce circadian oscillations of th...

  1. Acidic pH shock induces the expressions of a wide range of stress-response genes

    Directory of Open Access Journals (Sweden)

    Hong Soon-Kwang

    2008-12-01

    Full Text Available Abstract Background Environmental signals usually enhance secondary metabolite production in Streptomycetes by initiating complex signal transduction system. It is known that different sigma factors respond to different types of stresses, respectively in Streptomyces strains, which have a number of unique signal transduction mechanisms depending on the types of environmental shock. In this study, we wanted to know how a pH shock would affect the expression of various sigma factors and shock-related proteins in S. coelicolor A3(2. Results According to the results of transcriptional and proteomic analyses, the major number of sigma factor genes were upregulated by an acidic pH shock. Well-studied sigma factor genes of sigH (heat shock, sigR (oxidative stress, sigB (osmotic shock, and hrdD that play a major role in the secondary metabolism, were all strongly upregulated by the pH shock. A number of heat shock proteins including the DnaK family and chaperones such as GroEL2 were also observed to be upregulated by the pH shock, while their repressor of hspR was strongly downregulated. Oxidative stress-related proteins such as thioredoxin, catalase, superoxide dismutase, peroxidase, and osmotic shock-related protein such as vesicle synthases were also upregulated in overall. Conclusion From these observations, an acidic pH shock was considered to be one of the strongest stresses to influence a wide range of sigma factors and shock-related proteins including general stress response proteins. The upregulation of the sigma factors and shock proteins already found to be related to actinorhodin biosynthesis was considered to have contributed to enhanced actinorhodin productivity by mediating the pH shock signal to regulators or biosynthesis genes for actinorhodin production.

  2. Depolarization and Electrical Response of Porous PZT 95/5 Ferroelectric Ceramics under Shock Wave Compression

    Science.gov (United States)

    Wang, Zhi-Zhu; Jiang, Yi-Xuan; Zhang, Pan; Wang, Xing-Zhe; He, Hong-Liang

    2014-07-01

    The release of bound charges by shock wave loading of poled lead zirconate titanate (PZT 95/5) ferroelectric ceramics can result in a high-power electrical energy output. In this study, a theoretical formulation describing the depolarization and electrical response of porous PZT 95/5 ceramics in the normal mode to shock wave compression loading perpendicular to the polarization direction is developed. The depoling process in porous poled PZT 95/5 ceramics is analyzed by using a parallel circuit consisting of a current source, capacitance, conductance and a circuit load. This modeling takes the effects of porosity on wave velocity and remanent polarization and dielectric constant into account, and the effects of variations in dielectric constant and conductivity in the shocked region are assessed. The output current characteristics of porous PZT 95/5 ceramics under short-circuit and resistive load conditions are analyzed and compared with the experiment, with the results showing that theoretical predictions taking into consideration the porosity of ferroelectric ceramics are in close agreement with the experimentally measured electrical response of porous PZT 95/5 under shock wave compression loading.

  3. The membrane-associated transient receptor potential vanilloid channel is the central heat shock receptor controlling the cellular heat shock response in epithelial cells.

    Directory of Open Access Journals (Sweden)

    Zohar Bromberg

    Full Text Available The heat shock response (HSR is a highly conserved molecular response to various types of stresses, including heat shock, during which heat-shock proteins (Hsps are produced to prevent and repair damages in labile proteins and membranes. In cells, protein unfolding in the cytoplasm is thought to directly enable the activation of the heat shock factor 1 (HSF-1, however, recent work supports the activation of the HSR via an increase in the fluidity of specific membrane domains, leading to activation of heat-shock genes. Our findings support the existence of a plasma membrane-dependent mechanism of HSF-1 activation in animal cells, which is initiated by a membrane-associated transient receptor potential vanilloid receptor (TRPV. We found in various non-cancerous and cancerous mammalian epithelial cells that the TRPV1 agonists, capsaicin and resiniferatoxin (RTX, upregulated the accumulation of Hsp70, Hsp90 and Hsp27 and Hsp70 and Hsp90 respectively, while the TRPV1 antagonists, capsazepine and AMG-9810, attenuated the accumulation of Hsp70, Hsp90 and Hsp27 and Hsp70, Hsp90, respectively. Capsaicin was also shown to activate HSF-1. These findings suggest that heat-sensing and signaling in mammalian cells is dependent on TRPV channels in the plasma membrane. Thus, TRPV channels may be important drug targets to inhibit or restore the cellular stress response in diseases with defective cellular proteins, such as cancer, inflammation and aging.

  4. Geomagnetic and ionospheric response to the interplanetary shock on January 24, 2012

    Science.gov (United States)

    Belakhovsky, V. B.; Pilipenko, V. A.; Sakharov, Ya. A.; Lorentzen, D. L.; Samsonov, S. N.

    2017-08-01

    We have examined multi-instrument observations of the magnetospheric and ionospheric response to the interplanetary shock on January 24, 2012. Apart from various instruments, such as ground and space magnetometers, photometers, and riometers used earlier for a study of possible response to a shock, we have additionally examined variations of the ionospheric total electron content as determined from the global navigation satellite system receivers. Worldwide ground magnetometer arrays detected shock-induced sudden commencement (SC) with preliminary and main impulses throughout the dayside sector. A magnetic field compression was found to propagate through the magnetosphere with velocity less than the local Alfven velocity. Though the preliminary pulse was evident on the ground, its signature was not observed by the THEMIS and GOES satellites in the magnetosphere. The SC was accompanied by a burst of cosmic noise absorption recorded along a latitudinal network of riometers in the morning and evening sectors. The SC also caused an impulsive enhancement of dayside auroral emissions (shock aurora) as observed by the hyperspectral all-sky imager NORUSCA II at Barentsburg and the meridian scanning photometer at Longyearbyen (both at Svalbard). The VHF EISCAT radar (Tromsø, Norway) observed a SC-associated increase in electron density in the lower ionosphere (100-180 km). The system for monitoring geomagnetically induced currents (GICs) in power lines at the Kola Peninsula recorded a burst of GIC during the SC. A ≤10% positive pulse of the ionospheric total electron content caused by the SC in the dusk sector was found. On the basis of the multi-instrument information, a validated theory of the magnetosphere-ionosphere response to IP shock may be constructed.[Figure not available: see fulltext.

  5. Cars submerged in water.

    NARCIS (Netherlands)

    2010-01-01

    Crashes in which cars are submerged in deep water or in a ditch are often complicated and serious. Considering their severity and the fact that approximately half the fatalities in this crash type are not due to drowning but to injury, preventive measures are to be preferred above measures that have

  6. Global Analysis of Heat Shock Response in Desulfovibrio vulgaris Hildenborough.

    Energy Technology Data Exchange (ETDEWEB)

    Chhabra, S.R.; He, Q.; Huang, K.H.; Gaucher, S.P.; Alm, E.J.; He,Z.; Hadi, M.Z.; Hazen, T.C.; Wall, J.D.; Zhou, J.; Arkin, A.P.; Singh, A.K.

    2005-09-16

    Desulfovibrio vulgaris Hildenborough belongs to a class ofsulfate-reducing bacteria (SRB) and is found ubiquitously in nature.Given the importance of SRB-mediated reduction for bioremediation ofmetal ion contaminants, ongoing research on D. vulgaris has been in thedirection of elucidating regulatory mechanisms for this organism under avariety of stress conditions. This work presents a global view of thisorganism's response to elevated growth temperature using whole-celltranscriptomics and proteomics tools. Transcriptional response (1.7-foldchange or greater; Z>1.5) ranged from 1,135 genes at 15 min to 1,463genes at 120 min for a temperature up-shift of 13oC from a growthtemperature of 37oC for this organism and suggested both direct andindirect modes of heat sensing. Clusters of orthologous group categoriesthat were significantly affected included posttranslationalmodifications; protein turnover and chaperones (up-regulated); energyproduction and conversion (down-regulated), nucleotide transport,metabolism (down-regulated), and translation; ribosomal structure; andbiogenesis (down-regulated). Analysis of the genome sequence revealed thepresence of features of both negative and positive regulation whichincluded the CIRCE element and promoter sequences corresponding to thealternate sigma factors ?32 and ?54. While mechanisms of heat shockcontrol for some genes appeared to coincide with those established forEscherichia coli and Bacillus subtilis, the presence of unique controlschemes for several other genes was also evident. Analysis of proteinexpression levels using differential in-gel electrophoresis suggestedgood agreement with transcriptional profiles of several heat shockproteins, including DnaK (DVU0811), HtpG (DVU2643), HtrA (DVU1468), andAhpC (DVU2247). The proteomics study also suggested the possibility ofposttranslational modifications in the chaperones DnaK, AhpC, GroES(DVU1977), and GroEL (DVU1976) and also several periplasmic ABCtransporters.

  7. Module-based analysis of robustness tradeoffs in the heat shock response system.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Kurata

    2006-07-01

    Full Text Available Biological systems have evolved complex regulatory mechanisms, even in situations where much simpler designs seem to be sufficient for generating nominal functionality. Using module-based analysis coupled with rigorous mathematical comparisons, we propose that in analogy to control engineering architectures, the complexity of cellular systems and the presence of hierarchical modular structures can be attributed to the necessity of achieving robustness. We employ the Escherichia coli heat shock response system, a strongly conserved cellular mechanism, as an example to explore the design principles of such modular architectures. In the heat shock response system, the sigma-factor sigma32 is a central regulator that integrates multiple feedforward and feedback modules. Each of these modules provides a different type of robustness with its inherent tradeoffs in terms of transient response and efficiency. We demonstrate how the overall architecture of the system balances such tradeoffs. An extensive mathematical exploration nevertheless points to the existence of an array of alternative strategies for the existing heat shock response that could exhibit similar behavior. We therefore deduce that the evolutionary constraints facing the system might have steered its architecture toward one of many robustly functional solutions.

  8. Optimization of hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus in submerged fermentation using response surface methodology

    NARCIS (Netherlands)

    Chen, H.; Xu, X.; Zhu, Y.

    2010-01-01

    The objectives of this study were to investigate the effect of fermentation medium on the hydroxyl radical scavenging activity of exopolysaccharides from Inonotus obliquus by response surface methodology (RSM). A two-level fractional factorial design was used to evaluate the effect of different

  9. Calibration of accelerometers: determination of amplitude and phase response upon shock excitation

    Science.gov (United States)

    Link, A.; Täubner, A.; Wabinski, W.; Bruns, T.; Elster, C.

    2006-07-01

    A novel approach is proposed for the analysis of shock calibration measurements of accelerometers. The input/output behaviour of an accelerometer is represented by a physical model in terms of a second-order differential equation. The unknown model parameters, i.e. the coefficients of the differential equation, are estimated by a frequency domain least-squares approach. The derived model is then used to determine the frequency response of the accelerometer. The method was applied to calibration measurements upon shock excitations of two back-to-back accelerometers (ENDEVCO type 2270 and Brüel & Kjær type 8305). The determined frequency response was then compared to additional calibration measurements upon sinusoidal excitation. The sinusoidal excitation measurements were analysed by means of the established sine approximation method. Consistent results were obtained by the two methods which confirm the validity of the proposed modelling approach.

  10. A minimal titration model of the mammalian dynamical heat shock response

    Science.gov (United States)

    Sivéry, Aude; Courtade, Emmanuel; Thommen, Quentin

    2016-12-01

    Environmental stress, such as oxidative or heat stress, induces the activation of the heat shock response (HSR) and leads to an increase in the heat shock proteins (HSPs) level. These HSPs act as molecular chaperones to maintain cellular proteostasis. Controlled by highly intricate regulatory mechanisms, having stress-induced activation and feedback regulations with multiple partners, the HSR is still incompletely understood. In this context, we propose a minimal molecular model for the gene regulatory network of the HSR that reproduces quantitatively different heat shock experiments both on heat shock factor 1 (HSF1) and HSPs activities. This model, which is based on chemical kinetics laws, is kept with a low dimensionality without altering the biological interpretation of the model dynamics. This simplistic model highlights the titration of HSF1 by chaperones as the guiding line of the network. Moreover, by a steady states analysis of the network, three different temperature stress regimes appear: normal, acute, and chronic, where normal stress corresponds to pseudo thermal adaption. The protein triage that governs the fate of damaged proteins or the different stress regimes are consequences of the titration mechanism. The simplicity of the present model is of interest in order to study detailed modelling of cross regulation between the HSR and other major genetic networks like the cell cycle or the circadian clock.

  11. Response of Empty and Fluid-Filled, Submerged Spherical Shells to Plane and Spherical, Step-Exponential Acoustic Waves

    Directory of Open Access Journals (Sweden)

    Michael A. Sprague

    1999-01-01

    Full Text Available The title problem is solved through extension of a method previously formulated for plane step-wave excitation, which employs generalized Fourier series augmented by partial closure of those series at early time. The extension encompasses both plane and spherical incident waves with step-exponential pressure profiles. The effects of incident-wave curvature and profile decay rate on response behavior are examined. A method previously developed for assessing the discrepancy between calculated and measured response histories is employed to evaluate the convergence of the truncated series solutions. Also studied is the performance of doubly-asymptotic approximations. Finally, the efficacy of modified Cesàro summation for improving the convergence of series solutions is examined. The documented computer program that produced the numerical results appearing in this paper, SPHSHK/MODSUM, may be down-loaded from the Web site http://saviac.xservices.com.

  12. KPNA3-knockdown eliminates the second heat shock protein peak associated with the heat shock response of male silkworm pupae (Bombyx mori) by reducing heat shock factor transport into the nucleus.

    Science.gov (United States)

    Li, Jun; Wei, Guoqing; Wang, Lei; Qian, Cen; Li, Kedong; Zhang, Congfen; Dai, Lishang; Sun, Yu; Liu, Dongran; Zhu, Baojian; Liu, Chaoliang

    2016-01-10

    In this study, we investigated the role of karyopherin alpha 3 in the heat shock response in male silkworm pupae. Karyopherin alpha recognizes the classical nuclear location sequence on proteins and transports them into the nucleus by forming a trimetric complex with karyopherin beta. Three predicted karyopherin alphas (KPNA1, KPNA2 and KPNA3) have been identified from the silkworm Bombyx mori. Pull-down assay result showed that KPNA3 can pull down heat shock transcription factor (HSF) from proteins extracted from tissues using non-denature lysis buffer. After 45 °C heat shock on male B. mori pupae for 30 min, we identified two heat shock protein (HSP) mRNA expression peaks correlating with HSP19.9, HSP20.4 and HSP25.4 at 4 h (peak 1) and 24 h (peak 2). The second peak was eliminated after knockdown of KPNA3. Similar results were obtained following knockdown of HSF, which is the trans-activating factor of heat shock. However, KPNA3 knockdown was not accompanied by the decreased HSF protein levels at 24 h after heat shock which were observed following HSF knockdown. We also expressed recombinant protein GST-KPNA3 and His-HSF in Escherichia coli to perform GST pull-down assay and the result confirmed the interaction between KPNA3 and HSF. We concluded that KPNA3 knockdown eliminates the second heat shock protein peak in the heat shock response of male silkworm pupae by reducing HSF transport into the nucleus. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. The Effect of Diazoxide Upon Heat Shock Protein and Physiological Response to Hemorrhagic Shock and Cerebral Stroke

    Science.gov (United States)

    2006-06-16

    lithium MAPK mitogen-activated protein kinases Mg2+ magnesium xvi mg milligram ml milliliter mmHg millimeters of mercury mKATP mitochondria...xvii SDH succinate dehydrogenase Sh shock (hemorrhagic) sKATP cell surface potassium ATP channel SOD superoxide dismutase Str...the antioxidant enzyme superoxide dismutase (SOD) [51], and heat shock proteins (HSP70, HSP25 and HSP 32) [47]. Delayed preconditioning also reduces

  14. Research on Formation Mechanism of Dynamic Response and Residual Stress of Sheet Metal Induced by Laser Shock Wave

    Science.gov (United States)

    Feng, Aixin; Cao, Yupeng; Wang, Heng; Zhang, Zhengang

    2018-01-01

    In order to reveal the quantitative control of the residual stress on the surface of metal materials, the relevant theoretical and experimental studies were carried out to investigate the dynamic response of metal thin plates and the formation mechanism of residual stress induced by laser shock wave. In this paper, the latest research trends on the surface residual stress of laser shock processing technology were elaborated. The main progress of laser shock wave propagation mechanism and dynamic response, laser shock, and surface residual stress were discussed. It is pointed out that the multi-scale characterization of laser and material, surface residual stress and microstructure change is a new hotspot in laser shock strengthening technology.

  15. Is Inappropriate Response to Cosyntropin Stimulation Test an Indication of Corticosteroid Resistance in Septic Shock?

    Science.gov (United States)

    Hyvernat, Hervé; Doyen, Denis; Barel, Rémy; Kaidomar, Michel; Goubaux, Bernard; Pradier, Christian; Panaïa-Ferrari, Patricia; Dellamonica, Jean; Bernardin, Gilles

    2017-10-04

    We recently published a comparison of two hydrocortisone dosage regimens in patients with septic shock. We compare the results conferred by the two regimens as a function of the response to cosyntropin stimulation test (CST). Patients with septic shock were treated by one of two hydrocortisone regimens: either a 50-mg intravenous bolus every six hours during seven days (200 mg group; n = 49), or a 100-mg initial bolus followed by a continuous infusion of 300 mg daily for five days (300 mg group; n = 50). Nonresponders was defined as a CST response of 9 μg/dl or less. Nonresponders had more severe septic shock, greater fluid resuscitation needs and greater vasopressor dependence than responders. When analyzed only as a function of CST results, there was no difference in survival between responders and nonresponders. However, analyses crossing CST results and the treatment regimens showed that patients who were responders and in the 300 mg group had significantly less ICU mortality compared to responders in the 200 mg group (respective mortality of 24% vs 55% [RR 0.43, 95% CI, 0.20 to 0.94, p = 0.018]). Multivariate analysis identified baseline blood cortisol as an independent prognostic factor for 28-day mortality in all groups. [HR 1.002, 95% CI, 1.001 to 1.002, p =< 0.0001]). The results suggest that in patients who respond to CST, hydrocortisone can provide a dose-dependent benefit. In contrast, nonresponse may indicate corticosteroid resistance. This heterogeneity of response to hydrocortisone may explain the difficulties encountered when trying to demonstrate its benefit in septic shock.

  16. A neuronal GPCR is critical for the induction of the heat shock response in the nematode C. elegans

    National Research Council Canada - National Science Library

    Maman, Moria; Carvalhal Marques, Filipa; Volovik, Yuli; Dubnikov, Tatyana; Bejerano-Sagie, Michal; Cohen, Ehud

    2013-01-01

    In the nematode Caenorhabditis elegans, the heat shock response (HSR) is regulated at the organismal level by a network of thermosensory neurons that senses elevated temperatures and activates the HSR in remote tissues...

  17. Transformation of eEF1B[delta] into heat-shock response transcription factor by alternative splicing

    National Research Council Canada - National Science Library

    Taku Kaitsuka; Kazuhito Tomizawa; Masayuki Matsushita

    2011-01-01

    .... Here, we show that eukaryotic elongation factor 1Bδ (eEF1Bδ) changes its structure and function from a translation factor into a heat-shock response transcription factor by alternative splicing...

  18. Empirical Model Development for Predicting Shock Response on Composite Materials Subjected to Pyroshock Loading

    Science.gov (United States)

    Gentz, Steven J.; Ordway, David O; Parsons, David S.; Garrison, Craig M.; Rodgers, C. Steven; Collins, Brian W.

    2015-01-01

    The NASA Engineering and Safety Center (NESC) received a request to develop an analysis model based on both frequency response and wave propagation analyses for predicting shock response spectrum (SRS) on composite materials subjected to pyroshock loading. The model would account for near-field environment (approx. 9 inches from the source) dominated by direct wave propagation, mid-field environment (approx. 2 feet from the source) characterized by wave propagation and structural resonances, and far-field environment dominated by lower frequency bending waves in the structure. This report documents the outcome of the assessment.

  19. Empirical Model Development for Predicting Shock Response on Composite Materials Subjected to Pyroshock Loading: Appendices

    Science.gov (United States)

    Gentz, Steven J.; Ordway, David O.; Parsons, David S.; Garrison, Craig M.; Rodgers, C. Steven; Collins, Brian W.

    2015-01-01

    The NASA Engineering and Safety Center (NESC) received a request to develop an analysis model based on both frequency response and wave propagation analyses for predicting shock response spectrum (SRS) on composite materials subjected to pyroshock loading. The model would account for near-field environment (approx. 9 inches from the source) dominated by direct wave propagation, mid-field environment (approx. 2 feet from the source) characterized by wave propagation and structural resonances, and far-field environment dominated by lower frequency bending waves in the structure. This document contains appendices to the Volume I report.

  20. Empirical Model Development for Predicting Shock Response on Composite Materials Subjected to Pyroshock Loading. [Appendices

    Science.gov (United States)

    Gentz, Steven J.; Ordway, David O.; Parsons, David S.; Garrison, Craig M.; Rodgers, C. Steven; Collins, Brian W.

    2015-01-01

    The NASA Engineering and Safety Center (NESC) received a request to develop an analysis model based on both frequency response and wave propagation analyses for predicting shock response spectrum (SRS) on composite materials subjected to pyroshock loading. The model would account for near-field environment (9 inches from the source) dominated by direct wave propagation, mid-field environment (approximately 2 feet from the source) characterized by wave propagation and structural resonances, and far-field environment dominated by lower frequency bending waves in the structure. This document contains appendices to the Volume I report.

  1. The Role of the Membrane-Initiated Heat Shock Response in Cancer

    Science.gov (United States)

    Bromberg, Zohar; Weiss, Yoram

    2016-01-01

    The heat shock response (HSR) is a cellular response to diverse environmental and physiological stressors resulting in the induction of genes encoding molecular chaperones, proteases, and other proteins that are essential for protection and recovery from cellular damage. Since different perturbations cause accumulation of misfolded proteins, cells frequently encounter fluctuations in the environment which alter proteostasis. Since tumor cells use their natural adaptive mechanism of coping with stress and misfolded proteins, in recent years, the proteostasis network became a promising target for anti-tumor therapy. The membrane is the first to be affected by heat shock and therefore may be the first one to sense heat shock. The membrane also connects between the extracellular and the intracellular signals. Hence, there is a “cross talk” between the HSR and the membranes since heat shock can induce changes in the fluidity of membranes, leading to membrane lipid remodeling that occurs in several diseases such as cancer. During the last decade, a new possible therapy has emerged in which an external molecule is used that could induce membrane lipid re-organization. Since at the moment there are very few substances that regulate the HSR effectively, an alternative way has been searched to modulate chaperone activities through the plasma membrane. Recently, we suggested that the use of the membrane Transient Receptor Potential Vanilloid-1 (TRPV1) modulators regulated the HSR in cancer cells. However, the primary targets of the signal transduction pathway are yet un-known. This review provides an overview of the current literature regarding the role of HSR in membrane remodeling in cancer since a deep understanding of the membrane biology in cancer and the membrane heat sensing pathway is essential to design novel efficient therapies. PMID:27200359

  2. The role of the membrane-initiated Heat Shock Response in cancer

    Directory of Open Access Journals (Sweden)

    Zohar eBromberg

    2016-04-01

    Full Text Available The heat shock response (HSR is a cellular response to diverse environmental and physiological stressors resulting in the induction of genes encoding molecular chaperones, proteases and other proteins that are essential for protection and recovery from cellular damage. Since different perturbations cause accumulation of misfolded proteins, cells frequently encounter fluctuations in the environment which alter proteostasis. Since tumor cells use their natural adaptive mechanism of coping with stress and misfolded proteins, in recent years, the proteostasis network became a promising target for anti-tumor therapy. The membrane is the first to be affected by heat shock and therefore may be the first one to sense heat shock. The membrane also connects between the extracellular and the intracellular signals. Hence, there is a cross talk between the HSR and the membranes since heat shock can induce changes in the fluidity of membranes, leading to membrane lipid remodeling that occurs in several diseases such as cancer. During the last decade, a new possible therapy has emerged in which an external molecule is used that could induce membrane lipid re-organization. Since at the moment there are very few substances that regulate the HSR effectively, an alternative way has been searched to modulate chaperone activities through the plasma membrane. Recently, we suggested that the use of the membrane Transient Receptor Potential Vanilloid-1 (TRPV1 modulators regulated the HSR in cancer cells. However, the primary targets of the signal transduction pathway are yet un-known. This review provides an overview of the current literature regarding the role of HSR in membrane remodeling in cancer since a deep understanding of the membrane biology in cancer and the membrane heat sensing pathway is essential to design novel efficient therapies.

  3. Dynamic m6A mRNA methylation directs translational control of heat shock response

    Science.gov (United States)

    Zhou, Jun; Wan, Ji; Gao, Xiangwei; Zhang, Xingqian; Qian, Shu-Bing

    2015-01-01

    The most abundant mRNA post-transcriptional modification is N6-methyladenosine (m6A) that has broad roles in RNA biology1-5. In mammalian cells, the asymmetric distribution of m6A along mRNAs leaves relatively less methylation in the 5′ untranslated region (5′UTR) compared to other regions6,7. However, whether and how 5′UTR methylation is regulated is poorly understood. Despite the crucial role of the 5′UTR in translation initiation, very little is known whether m6A modification influences mRNA translation. Here we show that in response to heat shock stress, m6A is preferentially deposited to the 5′UTR of newly transcribed mRNAs. We found that the dynamic 5′UTR methylation is a result of stress-induced nuclear localization of YTHDF2, a well characterized m6A “reader”. Upon heat shock stress, the nuclear YTHDF2 preserves 5′UTR methylation of stress-induced transcripts by limiting the m6A “eraser” FTO from demethylation. Remarkably, the increased 5′UTR methylation in the form of m6A promotes cap-independent translation initiation, providing a mechanism for selective mRNA translation under heat shock stress. Using Hsp70 mRNA as an example, we demonstrate that a single site m6A modification in the 5′UTR enables translation initiation independent of the 5′ end m7G cap. The elucidation of the dynamic feature of 5′UTR methylation and its critical role in cap-independent translation not only expands the breadth of physiological roles of m6A, but also uncovers a previously unappreciated translational control mechanism in heat shock response. PMID:26458103

  4. On the Unsteadiness of a Transitional Shock Wave-Boundary Layer Interaction Using Fast-Response Pressure-Sensitive Paint

    Science.gov (United States)

    Lash, E. Lara; Schmisseur, John

    2017-11-01

    Pressure-sensitive paint has been used to evaluate the unsteady dynamics of transitional and turbulent shock wave-boundary layer interactions generated by a vertical cylinder on a flat plate in a Mach 2 freestream. The resulting shock structure consists of an inviscid bow shock that bifurcates into a separation shock and trailing shock. The primary features of interest are the separation shock and an upstream influence shock that is intermittently present in transitional boundary layer interactions, but not observed in turbulent interactions. The power spectral densities, frequency peaks, and normalized wall pressures are analyzed as the incoming boundary layer state changes from transitional to fully turbulent, comparing both centerline and outboard regions of the interaction. The present study compares the scales and frequencies of the dynamics of the separation shock structure in different boundary layer regimes. Synchronized high-speed Schlieren imaging provides quantitative statistical analyses as well as qualitative comparisons to the fast-response pressure sensitive paint measurements. Materials based on research supported by the U.S. Office of Naval Research under Award Number N00014-15-1-2269.

  5. Molecular Dynamics Simulation of the Shock Response of Nanocrystalline Cu-Ta Systems

    Science.gov (United States)

    Chen, Jie; Tschopp, Mark; Dongare, Avinash

    2017-06-01

    Nanocrystalline (nc) metal alloys comprising of second phase solutes show promise towards the design of high strength materials as compared to their coarse-grained counterparts. One such system is the high strength nc-Cu-Ta alloy. The improved deformation response is attributed to grain boundary pining due to the presence of Ta precipitates resulting in limited grain boundary sliding and rotation at high temperatures. A thorough understanding of the role of microstructure and chemistry on the nucleation and evolution of defects under shock loading conditions is crucial for the design and optimization of Cu-Ta alloys for dynamic loading environments. Large-scale molecular dynamics (MD) simulations are therefore performed to examine the deformation and failure behavior of Ta solute strengthened bulk nc-Cu systems under shock loading conditions. The dynamic evolution of defects (dislocations and twinning behavior) is investigated for variations in microstructure (grain size of nc-Cu and Ta distribution in the form of solute atoms as well as precipitates) during shock compression and spall failure. The MD simulations suggest that the spall strengths of the metal are largely influenced by the distribution of the Ta solute in the nc-Cu matrix. The effect of Ta distribution at the grain boundaries, grain interior and as precipitates on the evolution of dislocation densities and the spall strength of the alloy will be presented. NSF,CMMI-1454547.

  6. The Response to Heat Shock and Oxidative Stress in Saccharomyces cerevisiae

    Science.gov (United States)

    Morano, Kevin A.; Grant, Chris M.; Moye-Rowley, W. Scott

    2012-01-01

    A common need for microbial cells is the ability to respond to potentially toxic environmental insults. Here we review the progress in understanding the response of the yeast Saccharomyces cerevisiae to two important environmental stresses: heat shock and oxidative stress. Both of these stresses are fundamental challenges that microbes of all types will experience. The study of these environmental stress responses in S. cerevisiae has illuminated many of the features now viewed as central to our understanding of eukaryotic cell biology. Transcriptional activation plays an important role in driving the multifaceted reaction to elevated temperature and levels of reactive oxygen species. Advances provided by the development of whole genome analyses have led to an appreciation of the global reorganization of gene expression and its integration between different stress regimens. While the precise nature of the signal eliciting the heat shock response remains elusive, recent progress in the understanding of induction of the oxidative stress response is summarized here. Although these stress conditions represent ancient challenges to S. cerevisiae and other microbes, much remains to be learned about the mechanisms dedicated to dealing with these environmental parameters. PMID:22209905

  7. Association of coral algal symbionts with a diverse viral community responsive to heat shock

    KAUST Repository

    Brüwer, Jan D.

    2017-08-17

    Stony corals provide the structural foundation of coral reef ecosystems and are termed holobionts given they engage in symbioses, in particular with photosynthetic dinoflagellates of the genus Symbiodinium. Besides Symbiodinium, corals also engage with bacteria affecting metabolism, immunity, and resilience of the coral holobiont, but the role of associated viruses is largely unknown. In this regard, the increase of studies using RNA sequencing (RNA-Seq) to assess gene expression provides an opportunity to elucidate viral signatures encompassed within the data via careful delineation of sequence reads and their source of origin.Here, we re-analyzed an RNA-Seq dataset from a cultured coral symbiont (Symbiodinium microadriaticum, Clade A1) across four experimental treatments (control, cold shock, heat shock, dark shock) to characterize associated viral diversity, abundance, and gene expression. Our approach comprised the filtering and removal of host sequence reads, subsequent phylogenetic assignment of sequence reads of putative viral origin, and the assembly and analysis of differentially expressed viral genes. About 15.46% (123 million) of all sequence reads were non-host-related, of which <1% could be classified as archaea, bacteria, or virus. Of these, 18.78% were annotated as virus and comprised a diverse community consistent across experimental treatments. Further, non-host related sequence reads assembled into 56,064 contigs, including 4856 contigs of putative viral origin that featured 43 differentially expressed genes during heat shock. The differentially expressed genes included viral kinases, ubiquitin, and ankyrin repeat proteins (amongst others), which are suggested to help the virus proliferate and inhibit the algal host\\'s antiviral response.Our results suggest that a diverse viral community is associated with coral algal endosymbionts of the genus Symbiodinium, which prompts further research on their ecological role in coral health and resilience.

  8. Viscoelastic and shock response of nanoclay and graphite platelet reinforced vinyl ester nanocomposites

    Science.gov (United States)

    Almagableh, Ahmad Mohammad

    The focus of ongoing research at University of Mississippi is to develop stronger, safer and more cost-effective structural materials for the new generation naval ships with an emphasis on lightweight nanoparticle reinforced glass/carbon polymeric based composites and structural foams for blast, shock and impact mitigation. Brominated 510A-40 vinyl ester nanocomposite resin systems are planned to be used in the composite face sheets of sandwich structures with fire-resistant foam layered in between to further reduce flammability along with optimal flexural rigidity, vibration damping and enhanced energy absorption. In this work, the viscoelastic and dynamic performance of brominated nanoclay and graphite platelet reinforced vinyl ester nanocomposites for blast (shock) loading applications are studied. The Dynamic Mechanical Analyzer (DMA Q800) was used to obtain the viscoelastic properties, modulus (stiffness), creep/ stress relaxation, and damping (energy dissipation), of 1.25 and 2.5 wt. percent nanoclay and exfoliated graphite nanoplatelet (xGnP) reinforced brominated vinyl ester. Effects of frequency (time) on the viscoelastic behavior were investigated by sweeping the frequency over three decades: 0.01, 0.1, 1 and 10 Hz, and temperature range from 30-150°C at a step rate of 4°C per minute. Master curves were generated by time-temperature superpositioning of the experimental data at a reference temperature. Bromination of vinyl ester resin was found to significantly increase the glass transition temperature (Tg) and damping for all nanocomposites. The nano reinforced composites, however showed a drop in initial storage modulus with bromination. Nanocomposites with 1.25 and 2.5 M. percent graphite had the highest storage modulus along with the lowest damping among brominated specimens. In this research, a shock Tube, servo-hydraulic Material Testing System (MTS) and Split-Hopkinson Pressure Bar (SHPB) are used to characterize the mechanical response and energy

  9. Assessing Mongolian gerbil emotional behavior: effects of two shock intensities and response-independent shocks during an extended inhibitory-avoidance task.

    Science.gov (United States)

    Hurtado-Parrado, Camilo; González-León, Camilo; Arias-Higuera, Mónica A; Cardona, Angelo; Medina, Lucia G; García-Muñoz, Laura; Sánchez, Christian; Cifuentes, Julián; Forigua, Juan Carlos; Ortiz, Andrea; Acevedo-Triana, Cesar A; Rico, Javier L

    2017-01-01

    Despite step-down inhibitory avoidance procedures that have been widely implemented in rats and mice to study learning and emotion phenomena, performance of other species in these tasks has received less attention. The case of the Mongolian gerbil is of relevance considering the discrepancies in the parameters of the step-down protocols implemented, especially the wide range of foot-shock intensities (i.e., 0.4-4.0 mA), and the lack of information on long-term performance, extinction effects, and behavioral patterning during these tasks. Experiment 1 aimed to (a) characterize gerbils' acquisition, extinction, and steady-state performance during a multisession (i.e., extended) step-down protocol adapted for implementation in a commercially-available behavioral package (Video Fear Conditioning System-MED Associates Fairfax, VT, USA), and (b) compare gerbils' performance in this task with two shock intensities - 0.5 vs. 1.0 mA-considered in the low-to-mid range. Results indicated that the 1.0 mA protocol produced more reliable and clear evidence of avoidance learning, extinction, and reacquisition in terms of increments in freezing and on-platform time as well as suppression of platform descent. Experiment 2 aimed to (a) assess whether an alternate protocol consisting of a random delivery of foot shocks could replicate the effects of Experiment 1 and (b) characterize gerbils' exploratory behavior during the step-down task (jumping, digging, rearing, and probing). Random shocks did not reproduce the effects observed with the first protocol. The data also indicated that a change from random to response-dependent shocks affects (a) the length of each visit to the platform, but not the frequency of platform descends or freezing time, and (b) the patterns of exploratory behavior, namely, suppression of digging and rearing, as well as increments in probing and jumping. Overall, the study demonstrated the feasibility of the extended step-down protocol for studying steady

  10. The Anisotropic Dynamic Response of Ultrafast Shocked Single Crystal PETN and Beta-HMX

    Science.gov (United States)

    Zaug, Joseph; Armstrong, Michael; Crowhurst, Jonathan; Austin, Ryan; Ferranti, Louis; Fried, Laurence; Bastea, Sorin

    2015-06-01

    We report results from ultrafast shockwave experiments conducted on single crystal high explosives. Experimental results consist of 12 picosecond time-resolved dynamic response wave profile data, (ultrafast time-domain interferometry-TDI), which are used to validate calculations of anisotropic stress-strain behavior of shocked loaded energetic materials. In addition, here we present unreacted equations of state data from PETN and beta-HMX up to higher pressures than previously reported, which are used to extend the predictive confidence of hydrodynamic simulations. Our previous results derived from a 360 ps drive duration yielded anisotropic elastic wave response in single crystal beta-HMX ((110) and (010) impact planes). Here we provide results using a 3x longer drive duration to probe the plastic response regime of these materials. We compare our ultrafast time domain interferometry (TDI) results with previous gun platform results. Ultrafast time scale resolution TDI measurements further guide the development of continuum models aimed to study pore collapse and energy localization in shock-compressed crystals of beta-HMX. This work was performed under the auspices of the U.S. Department of Energy jointly by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  11. Basal Serum Cortisol Levels are not Predictive of Response to Corticotropin but Have Prognostic Significance in Patients with Septic Shock

    OpenAIRE

    Kwon, Yong Soo; Suh, Gee Young; Kang, Eun-Hae; Koh, Won-Jung; Chung, Man Pyo; Kim, Hojoong; Kwon, O Jung

    2007-01-01

    Because high levels of cortisol are frequently observed in patients with septic shock, low levels of serum cortisol are considered indicative of relative adrenal insufficiency (RAI). This study was performed to investigate whether pretest clinical characteristics, including basal serum cortisol levels, are predictive of serum cortisol response to corticotropin and whether basal cortisol levels have a prognostic significance in patients with septic shock. We performed a retrospective analysis ...

  12. Optimization of submerged vane parameters

    Indian Academy of Sciences (India)

    Submerged vanes are airfoils which are in general placed at certain angle with respect to the flow direction in a channel to induce artificial circulations downstream. By virtue of these artificially generated circulations, submerged vanes were utilized to protect banks of rivers against erosion, to control shifting of rivers, to avoid ...

  13. Optimization of submerged vane parameters

    Indian Academy of Sciences (India)

    H Sharma

    velocities simulated from CFD using standard k-x model were very much in accordance with what it was measured by Wang and Odgaard [4]. Thus, model can be used to study the turbulence characteristics around submerged vanes and to predict various parameters downstream of the submerged vanes. After the model ...

  14. Cortisol and glucose responses in juvenile striped catfish subjected to a cold shock

    Directory of Open Access Journals (Sweden)

    Mohammad Nabi Adloo

    2015-07-01

    Full Text Available Cold-shock stress happens when a fish had been adjusted to a specific water temperature or range of temperatures and is consequently exposed to a rapid drop in temperature, resulting in a cascade of physiological and behavioral responses and, in some cases, death. In the current study, the stress response of striped Catfish (Pangasianodon hypophthalmus was studied by evaluating serum cortisol and glucose level following an abrupt reduction in water temperature (from 28°C to 15°C at different time points (prior to, and after 1h, 12h and 24h cold treatment, respectively. Regardless of some mortality occurred in cold challenged fish, none of the physiological parameters changed during evaluation period. The results, suggesting that despite of necessity of cortisol and glucose evaluation in any of stress assessment, yet, due to their high variability in different fish species, additional complementary tests such as measurement of other stress hormones e.g. heat shock proteins as well as blood-cell counts (preferably in chronic experiments should also be included.

  15. Submerged AUV Charging Station

    Science.gov (United States)

    Jones, Jack A.; Chao, Yi; Curtin, Thomas

    2014-01-01

    Autonomous Underwater Vehicles (AUVs) are becoming increasingly important for military surveillance and mine detection. Most AUVs are battery powered and have limited lifetimes of a few days to a few weeks. This greatly limits the distance that AUVs can travel underwater. Using a series of submerged AUV charging stations, AUVs could travel a limited distance to the next charging station, recharge its batteries, and continue to the next charging station, thus traveling great distances in a relatively short time, similar to the Old West “Pony Express.” One solution is to use temperature differences at various depths in the ocean to produce electricity, which is then stored in a submerged battery. It is preferred to have the upper buoy submerged a reasonable distance below the surface, so as not to be seen from above and not to be inadvertently destroyed by storms or ocean going vessels. In a previous invention, a phase change material (PCM) is melted (expanded) at warm temperatures, for example, 15 °C, and frozen (contracted) at cooler temperatures, for example, 8 °C. Tubes containing the PCM, which could be paraffin such as pentadecane, would be inserted into a container filled with hydraulic oil. When the PCM is melted (expanded), it pushes the oil out into a container that is pressurized to about 3,000 psi (approx equals 20.7 MPa). When a valve is opened, the high-pressure oil passes through a hydraulic motor, which turns a generator and charges a battery. The low-pressure oil is finally reabsorbed into the PCM canister when the PCM tubes are frozen (contracted). Some of the electricity produced could be used to control an external bladder or a motor to the tether line, such that depth cycling is continued for a very long period of time. Alternatively, after the electricity is generated by the hydraulic motor, the exiting low-pressure oil from the hydraulic motor could be vented directly to an external bladder on the AUV, such that filling of the bladder

  16. Heat shock-induced dissociation of TRF2 from telomeres does not initiate a telomere-dependent DNA damage response.

    Science.gov (United States)

    Petrova, Nadezhda V; Velichko, Artem K; Kantidze, Omar L; Razin, Sergey V

    2014-05-01

    Telomeric repeat binding factor 2 (TRF2) is a well-studied shelterin complex subunit that plays a major role in the protection of chomosome ends and the prevention of the telomere-associated DNA damage response. We show that heat shock induces the dissociation of TRF2 from telomeres in human primary and cancer cell cultures. TRF2 is not simply degraded in response to heat shock, but redistributed thoughout the nucleoplasm. This TRF2 depletion/redistribution does not initiate the DNA damage response at chomosome termini. © 2014 International Federation for Cell Biology.

  17. The innate immune response in HIV/AIDS septic shock patients: a comparative study.

    Directory of Open Access Journals (Sweden)

    Rodrigo T Amancio

    Full Text Available INTRODUCTION: In recent years, the incidence of sepsis has increased in critically ill HIV/AIDS patients, and the presence of severe sepsis emerged as a major determinant of outcomes in this population. The inflammatory response and deregulated cytokine production play key roles in the pathophysiology of sepsis; however, these mechanisms have not been fully characterized in HIV/AIDS septic patients. METHODS: We conducted a prospective cohort study that included HIV/AIDS and non-HIV patients with septic shock. We measured clinical parameters and biomarkers (C-reactive protein and cytokine levels on the first day of septic shock and compared these parameters between HIV/AIDS and non-HIV patients. RESULTS: We included 30 HIV/AIDS septic shock patients and 30 non-HIV septic shock patients. The HIV/AIDS patients presented low CD4 cell counts (72 [7-268] cells/mm(3, and 17 (57% patients were on HAART before hospital admission. Both groups were similar according to the acute severity scores and hospital mortality. The IL-6, IL-10 and G-CSF levels were associated with hospital mortality in the HIV/AIDS septic group; however, the CRP levels and the surrogates of innate immune activation (cytokines were similar among HIV/AIDS and non-HIV septic patients. Age (odds ratio 1.05, CI 95% 1.02-1.09, p=0.002 and the IL-6 levels (odds ratio 1.00, CI 95% 1.00-1.01, p=0.05 were independent risk factors for hospital mortality. CONCLUSIONS: IL-6, IL-10 and G-CSF are biomarkers that can be used to predict prognosis and outcomes in HIV/AIDS septic patients. Although HIV/AIDS patients are immunocompromised, an innate immune response can be activated in these patients, which is similar to that in the non-HIV septic population. In addition, age and the IL-6 levels are independent risk factors for hospital mortality irrespective of HIV/AIDS disease.

  18. Different responses to heat shock stress revealed heteromorphic adaptation strategy of Pyropia haitanensis (Bangiales, Rhodophyta.

    Directory of Open Access Journals (Sweden)

    Qijun Luo

    Full Text Available Pyropia has a unique heteromorphic life cycle with alternation stages between thallus and conchocelis, which lives at different water temperatures in different seasons. To better understand the different adaptation strategies for temperature stress, we tried to observe comparative biochemical changes of Pyropia haitanensis based on a short term heat shock model. The results showed that: (1 At normal temperature, free-living conchocelis contains significantly higher levels of H2O2, fatty acid-derived volatiles, the copy number of Phrboh and Phhsp70 genes,the activities of NADPH oxidase and floridoside than those in thallus. The released H2O2 and NADPH oxidase activity of conchocelis were more than 7 times higher than those of thallus. The copy number of Phrboh in conchocelis was 32 times that in thallus. (2 After experiencing heat shock at 35°C for 30 min, the H2O2 contents, the mRNA levels of Phrboh and Phhsp70, NADPH oxidase activity and the floridoside content in thallus were all significantly increased. The mRNA levels of Phrboh increased 5.78 times in 5 min, NADPH oxidase activity increased 8.45 times in 20 min. (3 Whereas, in conchocelis, the changes in fatty acids and their down-stream volatiles predominated, significantly increasing levels of saturated fatty acids and decreasing levels of polyunsaturated fatty acids occurred, and the 8-carbon volatiles were accumulated. However, the changes in H2O2 content and expression of oxidant-related genes and enzymatic activity were not obvious. Overall, these results indicate that conchocelis maintains a high level of active protective apparatus to endure its survival at high temperature, while thallus exhibit typical stress responses to heat shock. It is concluded that Pyropia haitanensis has evolved a delicate strategy for temperature adaptation for its heteromorphic life cycle.

  19. Different responses to heat shock stress revealed heteromorphic adaptation strategy of Pyropia haitanensis (Bangiales, Rhodophyta).

    Science.gov (United States)

    Luo, Qijun; Zhu, Zhenggang; Zhu, Zhujun; Yang, Rui; Qian, Feijian; Chen, Haimin; Yan, Xiaojun

    2014-01-01

    Pyropia has a unique heteromorphic life cycle with alternation stages between thallus and conchocelis, which lives at different water temperatures in different seasons. To better understand the different adaptation strategies for temperature stress, we tried to observe comparative biochemical changes of Pyropia haitanensis based on a short term heat shock model. The results showed that: (1) At normal temperature, free-living conchocelis contains significantly higher levels of H2O2, fatty acid-derived volatiles, the copy number of Phrboh and Phhsp70 genes,the activities of NADPH oxidase and floridoside than those in thallus. The released H2O2 and NADPH oxidase activity of conchocelis were more than 7 times higher than those of thallus. The copy number of Phrboh in conchocelis was 32 times that in thallus. (2) After experiencing heat shock at 35°C for 30 min, the H2O2 contents, the mRNA levels of Phrboh and Phhsp70, NADPH oxidase activity and the floridoside content in thallus were all significantly increased. The mRNA levels of Phrboh increased 5.78 times in 5 min, NADPH oxidase activity increased 8.45 times in 20 min. (3) Whereas, in conchocelis, the changes in fatty acids and their down-stream volatiles predominated, significantly increasing levels of saturated fatty acids and decreasing levels of polyunsaturated fatty acids occurred, and the 8-carbon volatiles were accumulated. However, the changes in H2O2 content and expression of oxidant-related genes and enzymatic activity were not obvious. Overall, these results indicate that conchocelis maintains a high level of active protective apparatus to endure its survival at high temperature, while thallus exhibit typical stress responses to heat shock. It is concluded that Pyropia haitanensis has evolved a delicate strategy for temperature adaptation for its heteromorphic life cycle.

  20. RhoA Activation Sensitizes Cells to Proteotoxic Stimuli by Abrogating the HSF1-Dependent Heat Shock Response

    NARCIS (Netherlands)

    Meijering, Roelien A. M.; Wiersma, Marit; van Marion, Denise M. S.; Zhang, Deli; Hoogstra-Berends, Femke; Dijkhuis, Anne-Jan; Schmidt, Martina; Wieland, Thomas; Kampinga, Harm H.; Henning, Robert H.; Brundel, Bianca J. J. M.

    2015-01-01

    Background The heat shock response (HSR) is an ancient and highly conserved program of stress-induced gene expression, aimed at reestablishing protein homeostasis to preserve cellular fitness. Cells that fail to activate or maintain this protective response are hypersensitive to proteotoxic stress.

  1. Response of soil physico-chemical properties to restoration approaches and submergence in the water level fluctuation zone of the Danjiangkou Reservoir, China.

    Science.gov (United States)

    Shu, Xiao; Zhang, KeRong; Zhang, QuanFa; Wang, WeiBo

    2017-11-01

    With the completion of the Danjiangkou Dam, the impoundment and drainage of dams can significantly alter shorelines, hydrological regime, and sediment and can result in the loss of soil and original riparian vegetation. Revegetation may affect soil properties and have broad important implications both for ecological services and soil recovery. In this work, we investigated the soil properties under different restoration approaches, and before and after submergence in the water level fluctuation zone (WLFZ) of the Danjiangkou Reservoir. Soil physical (bulk density and soil moisture), chemical (pH, soil organic carbon, nitrogen, phosphorus and potassium contents), and heavy metals were determined. This study reported that restoration approaches have impacts on soil moisture, pH, N, soil organic carbon, P, K and heavy metals in the WLFZ of the Danjiangkou Reservoir. Our results indicated that different restoration approaches could increase the soil moisture while decrease soil pH. Higher soil organic carbon in propagule banks transplantation (PBT) and shrubs restoration (SR) indicate that PBT and SR may provide soil organic matter more quickly than trees restoration (TR). SR and TR could significantly improve the soil total P and available P. PBT and SR could improve the soil total K and available K. SR and TR could significantly promote Cu and Zn adsorption, and Pb and Fe release by plant. Submergence could significantly affect the soil pH, NO3--N, NH4+-N, total P and available P. Submergence could promote NO3--N and available P adsorption, and NH4+-N and total P release by soil. The soil quality index (SQI) values implied that TR and PBT greatly improved soil quality. The present study suggests that PBT and TR could be effective for soil restoration in WLFZ of the Danjiangkou Reservoir. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Response of S. boulardii cells to {sup 60} Co irradiation and heat shock

    Energy Technology Data Exchange (ETDEWEB)

    Neves, M.J.; Andrade, A.S.R.; Santos, R.G. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Nicoli, J.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. Microbiologia

    1997-12-31

    Full text. Preparation of Saccharomyces boulardii, a non pathogenic yeast, has been widely used in Europe and other countries to prevent gastrointestinal disorders. However the mechanism of action of theses cells on the illness is unknown but the efficacy of S. boulardii depends on its viability. As trehalose is a well known viability protectant in yeast cells against several adverse conditions, we determined its level. We measured the level of trehalose in cells submitted to heat shock, gamma irradiation and simulation of gastric environmental, all these conditions are commonly found during the bio therapeutic production and in the patients oral treatment. Trehalose levels were higher in yeast cells surviving to gamma irradiation ({sup 60} Cobalt) than in control cells. S. boulardii cells growth in log phase and submitted to the heat shock (40 deg C). Accumulated more trehalose than S. cerevisiae and unlikely to these cells, the pool of trehalose accumulated in S. boulardii was mobilized very slowly (70% of the trehalose pool was present 5 hours after the return to the normal temperature 30 deg C). Our results suggested a rather different trehalose metabolism in S. boulardii when compared with S. cerevisiae and showed that one of the response to the stress of irradiation was an increasing on the level of intracellular trehalose

  3. Genome-wide survey and expression profiling of heat shock proteins and heat shock factors revealed overlapped and stress specific response under abiotic stresses in rice.

    Science.gov (United States)

    Hu, Wenhuo; Hu, Guocheng; Han, Bin

    2009-04-01

    Heat shock proteins (Hsps) are molecular chaperons, which function in protein folding and assembly, protein intracellular localization and secretion, and degradation of misfolded and truncated proteins. Heat shock factors (Hsfs) are the transcriptional activators of Hsps. It has been reported that Hsps and Hsfs are widely involved in response to various abiotic stresses such as heat, drought, salinity and cold. To elucidate the function and regulation of rice Hsp and Hsf genes, we examined a global expression profiling with heat stressed rice seedling, and then compared our results with the previous rice data under cold, drought and salt stresses. The comparison revealed that, while most Hsfs and Hsps had highly similar and overlapped response and regulation patterns under different stresses, some of those genes showed significantly specific response to distinct stress. We also found that heat-responsive gene profiling differed largely from those under cold/drought/salt stresses, and that drought treatment was more effective to up-regulate Hsf expression in rice than in Arabidopsis. Overall, our data suggests that Hsps and Hsfs might be important elements in cross-talk of different stress signal transduction networks. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  4. Heat shock response in yeast involves changes in both transcription rates and mRNA stabilities.

    Directory of Open Access Journals (Sweden)

    Laia Castells-Roca

    Full Text Available We have analyzed the heat stress response in the yeast Saccharomyces cerevisiae by determining mRNA levels and transcription rates for the whole transcriptome after a shift from 25 °C to 37 °C. Using an established mathematical algorithm, theoretical mRNA decay rates have also been calculated from the experimental data. We have verified the mathematical predictions for selected genes by determining their mRNA decay rates at different times during heat stress response using the regulatable tetO promoter. This study indicates that the yeast response to heat shock is not only due to changes in transcription rates, but also to changes in the mRNA stabilities. mRNA stability is affected in 62% of the yeast genes and it is particularly important in shaping the mRNA profile of the genes belonging to the environmental stress response. In most cases, changes in transcription rates and mRNA stabilities are homodirectional for both parameters, although some interesting cases of antagonist behavior are found. The statistical analysis of gene targets and sequence motifs within the clusters of genes with similar behaviors shows that both transcriptional and post-transcriptional regulons apparently contribute to the general heat stress response by means of transcriptional factors and RNA binding proteins.

  5. Analysis of double-step response to an interplanetary shock in the dayside magnetosphere

    Directory of Open Access Journals (Sweden)

    K. Andréeová

    2014-10-01

    Full Text Available We present an analysis of double-step magnetic field enhancement caused by interplanetary (IP shock impacts on the Earth's magnetosphere. The structures were observed by the GOES-8, 10, 11, and 12 spacecraft in the dayside geostationary orbit, particularly during northward interplanetary magnetic field (IMF conditions. The double-step structures, similar to what is observed in the ground horizontal magnetic field (H component at low and mid latitudes, were observed preferentially on the dayside. Structures observed around 12–15 magnetic local time (MLT displayed the steepest initial enhancement step, followed by a magnetic field strength decrease before the second enhancement step. At other dayside MLTs of the geostationary orbit, the initial response was smoother, and no decrease was observed before the second step. We suggest that this MLT asymmetry in the decrease of the total magnetic field is caused by the pushing of the plasmaspheric ions over the geostationary orbit due to the magnetospheric compression.

  6. Dynamic Fracture of Nanocomposites and Response of Fiber Composite Panels to Shock Loading

    Science.gov (United States)

    Shukla, Arun

    2009-06-01

    This lecture will present studies on the response of novel engineering materials to extreme dynamic loadings. In particular, the talk will focus on the behavior of sandwich composite materials to shock loading and dynamic fracture of nano-composite materials. Results from an experimental study on the response of sandwich materials to controlled blast loading will be presented. In this study, a shock tube facility was utilized to apply blast loading to simply supported plates of E-glass vinyl ester/PVC foam sandwich composite materials. Pressure sensors were mounted at the end of the muzzle section of the shock tube to measure the incident pressure and the reflected pressure profiles during the experiment. A high speed digital camera was utilized to capture the real time side deformation of the materials, as well as the development and progression of damage. Macroscopic and microscopic examination was then implemented to study the post-mortem damage. Conclusions on the relative performance of sandwich composites under blast loadings will also be discussed. Results from an experimental investigation conducted to evaluate the mechanical properties of novel materials fabricated using nano sized particles in polymer matrix will also be presented. Unsaturated polyester resin specimens embedded with small loadings of nano sized particles of TiO2 and Al2O3 were fabricated using a direct ultrasonification method to study the effects of nanosized particles on nanocomposite fracture properties. The ultrasonification method employed produced nanocomposites with excellent particle dispersion as verified by TEM. Experiments were conducted to investigate the dynamic crack initiation and rapid crack propagation in theses particle reinforced materials. High-speed digital imaging was employed along with dynamic photoelasticity to obtain real time, full-field quantification of the stress field associated with the dynamic fracture process. Birefringent coatings were used to conduct

  7. LDH inhibition impacts on heat shock response and induces senescence of hepatocellular carcinoma cells.

    Science.gov (United States)

    Manerba, Marcella; Di Ianni, Lorenza; Govoni, Marzia; Roberti, Marinella; Recanatini, Maurizio; Di Stefano, Giuseppina

    2017-07-15

    In normal cells, heat shock response (HSR) is rapidly induced in response to a variety of harmful conditions and represents one of the most efficient defense mechanism. In cancer tissues, constitutive activation converts HSR into a life-threatening process, which plays a major role in helping cell survival and proliferation. Overexpression of heat shock proteins (HSPs) has been widely reported in human cancers and was found to correlate with tumor progression. Hepatocellular carcinoma is one of the conditions in which HSR activation was shown to have the highest clinical significance. Transcription of HSPs is induced by HSF-1, which also activates glycolytic metabolism and increases the expression of LDH-A, the master regulator of the Warburg effect. In this paper, we tried to explore the relationship between HSR and LDH-A. In cultured hepatocellular carcinoma cells, by using two enzyme inhibitors (oxamate and galloflavin), we found that the reduction of LDH-A activity led to decreased level and function of the major HSPs involved in tumorigenesis. Galloflavin (a polyphenol) also inhibited the ATPase activity of two of the examined HSPs. Finally, hindering HSR markedly lowered the alpha-fetoprotein cellular levels and induced senescence. Specific inhibitors of single HSPs are currently under evaluation in different neoplastic diseases. However, one of the effects usually observed during treatment is a compensatory elevation of other HSPs, which decreases treatment efficacy. Our results highlight a connection between LDH and HSR and suggest LDH inhibition as a way to globally impact on this tumor promoting process. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. HSP70-Inducible hNIS-IRES-eGFP Reporter Imaging: Response to Heat Shock

    Directory of Open Access Journals (Sweden)

    Jiantu Che

    2007-11-01

    Full Text Available A retroviral vector pQHSP70/hNIS-IRES-eGFP (pQHNIG70 was constructed containing the hNIS-IRES-eGFP dual-reporter genes under the control of an inducible human heat shock protein (HSP70 promoter and RG2-pQHSP70/hNIS-IRES-eGFP (RG2-pQHNIG70 transduced cells were generated. Heat-induced expression of both reporter genes in RG2-pQHNIG70 cells was validated by enhanced green fluorescent protein (eGFP fluorescence-activated cell sorter, in vitro radiotracer assays, and immunoblot and immunocytochemistry. A 2.2- to 6.1-fold (131I−, a 6.1- to 14.4-fold (99mTcO4−, and a 5.1- to 39-fold (fluorescence increase above baseline was observed in response to graded hyperthermia (39–43°C. Increases in eGFP fluorescence and radiotracer uptake were first noted at 6 hours, reached a maximum at 24 hours, and fell toward baseline at 72 hours. A stable ratio of radiotracer uptake to eGFP fluorescence and to heat shock protein (HSP70 protein was demonstrated over a wide range of expression levels, induced by different levels of heating. We also demonstrate that the local application of heat on RG2-pQHNIG70 xenografts can effectively induce hNIS and eGFP gene expression in vivo and that this expression can be efficiently visualized by fluorescence, scintigraphic, and micro–positron emission tomography imaging. Endogenous HSP70 protein and reporter expression was confirmed by postmortem tissue evaluations (immunoblot and immunohistochemistry. The pQHNIG70 reporter system can be used to study stress and drug responses in transduced cells and tissues.

  9. Caffeine Induces the Stress Response and Up-Regulates Heat Shock Proteins in Caenorhabditis elegans.

    Science.gov (United States)

    Al-Amin, Mohammad; Kawasaki, Ichiro; Gong, Joomi; Shim, Yhong-Hee

    2016-02-01

    Caffeine has both positive and negative effects on physiological functions in a dose-dependent manner. C. elegans has been used as an animal model to investigate the effects of caffeine on development. Caffeine treatment at a high dose (30 mM) showed detrimental effects and caused early larval arrest. We performed a comparative proteomic analysis to investigate the mode of action of high-dose caffeine treatment in C. elegans and found that the stress response proteins, heat shock protein (HSP)-4 (endoplasmic reticulum [ER] chaperone), HSP-6 (mitochondrial chaperone), and HSP-16 (cytosolic chaperone), were induced and their expression was regulated at the transcriptional level. These findings suggest that high-dose caffeine intake causes a strong stress response and activates all three stress-response pathways in the worms, including the ER-, mitochondrial-, and cytosolic pathways. RNA interference of each hsp gene or in triple combination retarded growth. In addition, caffeine treatment stimulated a food-avoidance behavior (aversion phenotype), which was enhanced by RNAi depletion of the hsp-4 gene. Therefore, up-regulation of hsp genes after caffeine treatment appeared to be the major responses to alleviate stress and protect against developmental arrest.

  10. LPS-induced delayed preconditioning is mediated by Hsp90 and involves the heat shock response in mouse kidney.

    Directory of Open Access Journals (Sweden)

    Tamás Kaucsár

    Full Text Available We and others demonstrated previously that preconditioning with endotoxin (LPS protected from a subsequent lethal LPS challenge or from renal ischemia-reperfusion injury (IRI. LPS is effective in evoking the heat shock response, an ancient and essential cellular defense mechanism, which plays a role in resistance to, and recovery from diseases. Here, by using the pharmacological Hsp90 inhibitor novobiocin (NB, we investigated the role of Hsp90 and the heat shock response in LPS-induced delayed renal preconditioning.Male C57BL/6 mice were treated with preconditioning (P: 2 mg/kg, i.p. and subsequent lethal (L: 10 mg/kg, i.p. doses of LPS alone or in combination with NB (100 mg/kg, i.p.. Controls received saline (C or NB.Preconditioning LPS conferred protection from a subsequent lethal LPS treatment. Importantly, the protective effect of LPS preconditioning was completely abolished by a concomitant treatment with NB. LPS induced a marked heat shock protein increase as demonstrated by Western blots of Hsp70 and Hsp90. NB alone also stimulated Hsp70 and Hsp90 mRNA but not protein expression. However, Hsp70 and Hsp90 protein induction in LPS-treated mice was abolished by a concomitant NB treatment, demonstrating a NB-induced impairment of the heat shock response to LPS preconditioning.LPS-induced heat shock protein induction and tolerance to a subsequent lethal LPS treatment was prevented by the Hsp90 inhibitor, novobiocin. Our findings demonstrate a critical role of Hsp90 in LPS signaling, and a potential involvement of the heat shock response in LPS-induced preconditioning.

  11. Material response mechanisms are needed to obtain highly accurate experimental shock wave data

    Science.gov (United States)

    Forbes, Jerry W.

    2017-01-01

    The field of shock wave compression of matter has provided a simple set of equations relating thermodynamic and kinematic parameters that describe the conservation of mass, momentum and energy across a steady plane shock wave with one-dimensional flow. Well-known condensed matter shock wave experimental results will be reviewed to see whether the assumptions required for deriving these simple R-H equations are satisfied. Note that the material compression model is not required for deriving the 1-D conservation flow equations across a steady plane shock front. However, this statement is misleading from a practical experimental viewpoint since obtaining small systematic errors in shock wave measured parameters requires the material compression and release mechanisms to be known. A review will be presented on errors in shock wave data from common experimental techniques for elastic-plastic solids. Issues related to time scales of experiments, steady waves with long rise times and detonations will also be discussed

  12. Sex difference in the heat shock response to high external load resistance training in older humans.

    Science.gov (United States)

    Njemini, Rose; Forti, Louis Nuvagah; Mets, Tony; Van Roie, Evelien; Coudyzer, Walter; Beyer, Ingo; Delecluse, Christophe; Bautmans, Ivan

    2017-07-01

    Literature reports on the effects of resistance training on heat shock protein70 (Hsp70) adaptation in older subjects are scarce. Moreover, the optimum training load required to obtain a beneficial adaptation profile is lacking. Therefore, the aim of this study was to determine the effects of resistance training at various external loads on extracellular Hsp70 (eHsp70) resting levels in older humans. Fifty-six community-dwelling older (68±5years) volunteers were randomized to 12weeks of resistance training (3×/week) at either high-resistance (HIGH, 8 males, 10 females, 2×10-15 repetitions at 80% 1RM), low resistance (LOW, 9 Males, 10 Females, 1×80-100 repetitions at 20% 1RM), or mixed low resistance (LOW+, 9 Males, 10 Females, 1×60 repetitions at 20% 1RM followed by 1×10-20 repetitions at 40% 1RM). Serum was available from 48 out of the 56 participants at baseline and after 12weeks for determination of eHsp70. Mid-thigh muscle volume (computed tomography), muscle strength (1RM & Biodex dynamometer) and physical functioning (including 6min walk distance [6MWD]) were assessed. There was a sex-related dichotomy in the heat shock response to high external load training. We observed a significant decrease in eHsp70 concentration in the HIGH group for female, but not male, subjects. At baseline, men had a larger muscle volume, leg press and leg extension 1RM compared to women (all ptraining at high external load decreases the resting levels of eHsp70 in older females. Whether this reflects a better health status requires further investigation. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The stress response against denatured proteins in the deletion of cytosolic chaperones SSA1/2 is different from heat-shock response in Saccharomyces cerevisiae

    Science.gov (United States)

    Matsumoto, Rena; Akama, Kuniko; Rakwal, Randeep; Iwahashi, Hitoshi

    2005-01-01

    Background A yeast strain lacking the two genes SSA1 and SSA2, which encode cytosolic molecular chaperones, acquires thermotolerance as well as the mild heat-shocked wild-type yeast strain. We investigated the genomic response at the level of mRNA expression to the deletion of SSA1/2 in comparison with the mild heat-shocked wild-type using cDNA microarray. Results Yeast cDNA microarray analysis revealed that genes involved in the stress response, including molecular chaperones, were up-regulated in a similar manner in both the ssa1/2 deletion mutant and the mild heat-shocked wild-type. Genes involved in protein synthesis were up-regulated in the ssa1/2 deletion mutant, but were markedly suppressed in the mild heat-shocked wild-type. The genes involved in ubiquitin-proteasome protein degradation were also up-regulated in the ssa1/2 deletion mutant, whereas the unfolded protein response (UPR) genes were highly expressed in the mild heat-shocked wild-type. RT-PCR confirmed that the genes regulating protein synthesis and cytosolic protein degradation were up-regulated in the ssa1/2 deletion mutant. At the translational level, more ubiquitinated proteins and proteasomes were detected in the ssa1/2 deletion mutant, than in the wild-type, confirming that ubiquitin-proteasome protein degradation was up-regulated by the deletion of SSA1/2. Conclusion These results suggest that the mechanism for rescue of denatured proteins in the ssa1/2 deletion mutant is different from that in the mild heat-shocked wild-type: Activated protein synthesis in the ssa1/2 deletion mutant supplies a deficiency of proteins by their degradation, whereas mild heat-shock induces UPR. PMID:16209719

  14. Reduced heat shock response in human mononuclear cells during aging and its association with polymorphisms in HSP70 genes

    DEFF Research Database (Denmark)

    Singh, Ripudaman; Kølvraa, Steen; Bross, Peter

    2006-01-01

    was measured by genotyping the subjects for 3 single nucleotide polymorphisms, HSPA1A(A-110C), HSPA1B(A1267G), and HSPA1L(T2437C), 1 each in the 3 HSP70 genes. A significant age-related decrease in the induction of Hsp70 occurred after heat shock in both monocytes and lymphocytes. The noninducible......Age-dependent changes in heat shock response (HSR) were studied in mononuclear cells (monocytes and lymphocytes) collected from young (mean age = 22.6 +/- 1.7 years) and middle-aged (mean age = 56.3 +/- 4.7 years) subjects after 1 hour of heat shock at 42 degrees C. Genotype-specific HSR...... and inducible forms of Hsp70 decreased 1.3-fold (P induction than TT carriers in both monocytes...

  15. Low pressure shock response and dynamic failure of high density- and ultra-high molecular weight polyethylene

    Science.gov (United States)

    Jordan, Jennifer; Dattelbaum, Dana; Schilling, Benjamin; Welch, Cynthia; Stull, Jamie

    2017-06-01

    Polyethylene exhibits mechanical responses tailorable to a given application based on its network and chain structures (crystallinity) and molecular weight. Earlier reports have provided Hugoniot data for polyethylene over a broad range of conditions to very high shock stresses, while others focused on the discontinuous low pressure Hugoniot of crystalline forms of polyethylene. Surprisingly little is known about the influence of crystalline structure, and associated crystalline phase transitions including melt, on its dynamic compression response. Two different materials - high density polyethylene and ultrahigh molecular weight polyethylene - were chosen for investigation of the influence of a high percentage of crystallinity (>40%) on the shock response and dynamic tensile failure (spall). We have applied in-situ electromagnetic gauges to measure the evolution of particle velocity wave profiles with propagation distance to elucidate the nature of the discontinuous Hugoniot at low pressures. The first evidence of a three-wave structure in highly crystalline polyethylene was measured above a shock stress of 0.5 GPa. Above this region of discontinuity in the principal Hugoniot, the transition is overdriven, and a single shock wave is observed to stresses exceeding 10 GPa. Details about the nature of the transition, including wave velocities and changes in density, will be presented. Further, a series of dynamic tensile (spall) experiments were performed on polyethylene and will be discussed.

  16. An on-road shock and vibration response test series utilizing worst case and statistical analysis techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cap, J.S. [Sandia National Labs., Albuquerque, NM (US). Mechanical and Thermal Environments Dept.

    1997-11-01

    Defining the maximum expected shock and vibration responses for an on-road truck transportation environment is strongly dependent on the amount of response data that can be obtained. One common test scheme consists of measuring response data over a relatively short prescribed road course and then reviewing that data to obtain the maximum response levels. The more mathematically rigorous alternative is to collect an unbiased ensemble of response data during a long road trip. This paper compares data gathered both ways during a recent on-road certification test for a tractor trailer van being designed by Sandia.

  17. The oxygen reduction pathway and heat shock stress response are both required for Entamoeba histolytica pathogenicity.

    Science.gov (United States)

    Olivos-García, Alfonso; Saavedra, Emma; Nequiz, Mario; Santos, Fabiola; Luis-García, Erika Rubí; Gudiño, Marco; Pérez-Tamayo, Ruy

    2016-05-01

    Several species belonging to the genus Entamoeba can colonize the mouth or the human gut; however, only Entamoeba histolytica is pathogenic to the host, causing the disease amoebiasis. This illness is responsible for one hundred thousand human deaths per year worldwide, affecting mainly underdeveloped countries. Throughout its entire life cycle and invasion of human tissues, the parasite is constantly subjected to stress conditions. Under in vitro culture, this microaerophilic parasite can tolerate up to 5 % oxygen concentrations; however, during tissue invasion the parasite has to cope with the higher oxygen content found in well-perfused tissues (4-14 %) and with reactive oxygen and nitrogen species derived from both host and parasite. In this work, the role of the amoebic oxygen reduction pathway (ORP) and heat shock response (HSP) are analyzed in relation to E. histolytica pathogenicity. The data suggest that in contrast with non-pathogenic E. dispar, the higher level of ORP and HSPs displayed by E. histolytica enables its survival in tissues by diminishing and detoxifying intracellular oxidants and repairing damaged proteins to allow metabolic fluxes, replication and immune evasion.

  18. Small Heat Shock Protein Responses Differ between Chaparral Shrubs from Contrasting Microclimates

    Directory of Open Access Journals (Sweden)

    Charles A. Knight

    2010-01-01

    Full Text Available Small heat shock protein (sHsp responses were studied for two evergreen perennial shrubs in the northern California chaparral; one common on warm, south-facing slopes (Ceanothus cuneatus, and the other on cooler, north-facing slopes (Prunus ilicifolia. Small Hsp expression was induced experimentally for field collected leaves. Leaf collections were made where the species co-occur. Small Hsp expression was quantified using two antibodies, one specific to a chloroplast 22 kD sHsp and another that detects a broad range of sHsps. Differences between chloroplast sHsp accumulation, which protects thermally labile proteins in PSII, and the general sHsp response were examined. The species from the cooler microclimate, Prunus, had a lower induction temperature and accumulated greater levels of sHsps at low temperatures. Both Prunus and Ceanothus reached peak sHsp expression at 42∘C. The species from the warmer microclimate, Ceanothus, had greater sHsp expression at higher temperatures. Chloroplast sHsp expression generally tracked sHsp expression in Ceanothus, but in Prunus general Hsps were elevated before chloroplast sHsps. Variation between species for sHsp expression (induction temperatures, accumulation levels, and the duration of expression coupled with the costs of Hsp synthesis, may contribute to differences in the abundance and distribution of plants across environmental gradients.

  19. Behavioral and molecular responses to electroconvulsive shock differ between genetic and environmental rat models of depression.

    Science.gov (United States)

    Luo, Jie; Min, Su; Wei, Ke; Cao, Jun; Wang, Bin; Li, Ping; Dong, Jun; Liu, Yuanyuan

    2015-04-30

    Depression׳s causes play a role in individuals׳ different responses to antidepressant treatments, which require advancements. We investigated the mechanisms behind and responses to a highly effective antidepressant treatment, electroconvulsive therapy (ECT), in rat models with different (genetic or environmental) depression causes. Wistar Kyoto (WKY) rats and Wistar rats treated with chronic unpredictable mild stresses (CUMS) were used as genetic and environmental rat models of depression, respectively. The rats underwent electroconvulsive shock (ECS, the animal analog of ECT) or sham ECS. We performed a sucrose preference test, open field test, and Morris water maze to assess behavior. Hippocampal neuron numbers were measured with Nissl stain. Hippocampal BDNF, CREB, and p-CREB proteins were assayed with ELISA or western blotting. The main results showed that ECS impaired WKY rats׳ memories but improved CUMS rats׳ memories. It elevated hippocampal BDNF and CREB proteins only in CUMS rats, while it improved depressive behavior and hippocampal p-CREB protein levels in both rats, with more effective regulations in the CUMS rats. ECS did not change the hippocampal neuron number in both rats. These findings suggest that ECS exerted up-regulating effects on hippocampal BDNF and CREB (and its phosphorylation) in depressed rats, and the environmental model responded better. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Shock vibration and damage responses of primary auxiliary buildings from aircraft impact

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Shup [Korea Atomic Energy Research Institute, 1045 Daeduk-daero, Dukjin-dong, Yuseong-gu, Daejeon 305-303 (Korea, Republic of); Department of Civil and Environmental Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Hahm, Daegi [Korea Atomic Energy Research Institute, 1045 Daeduk-daero, Dukjin-dong, Yuseong-gu, Daejeon 305-303 (Korea, Republic of); Park, Taehyo, E-mail: cepark@hanyang.ac.kr [Department of Civil and Environmental Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2016-12-15

    Highlights: • Aircraft impact analyses of PABs were performed using both the force-time history method and missile-target interaction method. • The jet fuel was considered by using the added mass modeling method and SPH method, respectively. • The FRS and the structural integrity of the external wall of the PABs against an aircraft impact were analyzed. - Abstract: Safety assessments on nuclear power plants (NPPs) subjected to an aircraft impact (AI) caused by terrorists are pivotal focuses for amelioration of present. To date, most studies have mainly focused on structure responses and the integrity of the containment building at a nuclear island (NI) subjected to AI. However, the safety assessment of internal equipment and components by shock vibration as well as the structure damage induced by AI are also important. In this study, aircraft impact analyses (AIA) of primary auxiliary buildings (PABs) were carried out using both the force–time history method and the missile–target interaction method. For the AIA, the jet fuel was taken into account by using the added mass modeling method and the smooth particles hydrodynamics (SPH) method, respectively. In addition, the floor response spectra (FRS) and the structural integrity of the external wall of the PAB against an AI were analyzed. Finally, the difference in the FRS at the location of the components on both sides of the bay was analyzed.

  1. On the Shock Stress, Substructure Evolution, and Spall Response of Commercially Pure 1100-O Aluminum

    Science.gov (United States)

    2014-12-01

    were also previously measured by Williams et al. [20,21], and these values were used to compute the elastic properties. The density measurements were...Gray III, Shock recovery experiments: an assesment , in: S.C. Schmidt, J.N. Johnson, L.W. Davison (Eds.), Shock Compression of Condensed Matter – 1989

  2. Dynamic response and residual stress fields of Ti6Al4V alloy under shock wave induced by laser shock peening

    Science.gov (United States)

    Sun, Rujian; Li, Liuhe; Zhu, Ying; Zhang, Lixin; Guo, Wei; Peng, Peng; Li, Bo; Guo, Chao; Liu, Lei; Che, Zhigang; Li, Weidong; Sun, Jianfei; Qiao, Hongchao

    2017-09-01

    Laser shock peening (LSP), an innovative surface treatment technique, generates compressive residual stress on the surface of metallic components to improve their fatigue performance, wear resistance and corrosion resistance. To illustrate the dynamic response during LSP and residual stress fields after LSP, this study conducted FEM simulations of LSP in a Ti6Al4V alloy. Results showed that when power density was 7 GW cm-2, a plastic deformation occurred at 10 ns during LSP and increased until the shock pressure decayed below the dynamic yield strength of Ti6Al4V after 60 ns. A maximum tensile region appeared beneath the surface at around 240 ns, forming a compressive-tensile-compressive stress sandwich structure with a thickness of 98, 1020 and 606 μm for each layer. After the model became stabilized, the value of the surface residual compressive stress was 564 MPa at the laser spot center. Higher value of residual stress across the surface and thicker compressive residual stress layers were achieved by increasing laser power density, impact times and spot sizes during LSP. A ‘Residual stress hole’ occurred with a high laser power density of 9 GW cm-2 when laser pulse duration was 10 ns, or with a long laser pulse duration of 20 ns when laser power density was 7 GW cm-2 for Ti6Al4V. This phenomenon occurred because of the permanent reverse plastic deformation generated at laser spot center.

  3. Basal serum cortisol levels are not predictive of response to corticotropin but have prognostic significance in patients with septic shock.

    Science.gov (United States)

    Kwon, Yong Soo; Suh, Gee Young; Kang, Eun-Hae; Koh, Won-Jung; Chung, Man Pyo; Kim, Hojoong; Kwon, O Jung

    2007-06-01

    Because high levels of cortisol are frequently observed in patients with septic shock, low levels of serum cortisol are considered indicative of relative adrenal insufficiency (RAI). This study was performed to investigate whether pretest clinical characteristics, including basal serum cortisol levels, are predictive of serum cortisol response to corticotropin and whether basal cortisol levels have a prognostic significance in patients with septic shock. We performed a retrospective analysis of 68 patients with septic shock who underwent short corticotropin stimulation testing. RAI was defined as an increase in cortisol level significantly higher simplified acute physiology score II (SAPS II) and sequential organ failure assessment (SOFA) scores than the non-RAI group. The incidence of RAI was the same regardless of the basal serum cortisol level (p=0.447). The hospital mortality rate was 58.8% and was not significantly different between the RAI and non-RAI groups. However, a high basal serum cortisol level (> or =30 microgram/dL) was significantly associated with in-hospital mortality. In conclusion, our data suggest that basal serum cortisol levels are not predictive of serum cortisol response to corticotropin but have a significant prognostic value in patients with septic shock.

  4. Dayside response of the magnetosphere to a small shock compression: Van Allen Probes, Magnetospheric MultiScale, and GOES‐13

    Science.gov (United States)

    Breneman, A.; Colpitts, C.; Dombeck, J.; Thaller, S.; Tian, S.; Wygant, J.; Fennell, J.; Hudson, M. K.; Ergun, Robert; Russell, C. T.; Torbert, Roy; Lindqvist, Per‐Arne; Burch, J.

    2017-01-01

    Abstract Observations from Magnetospheric MultiScale (~8 Re) and Van Allen Probes (~5 and 4 Re) show that the initial dayside response to a small interplanetary shock is a double‐peaked dawnward electric field, which is distinctly different from the usual bipolar (dawnward and then duskward) signature reported for large shocks. The associated E × B flow is radially inward. The shock compressed the magnetopause to inside 8 Re, as observed by Magnetospheric MultiScale (MMS), with a speed that is comparable to the E × B flow. The magnetopause speed and the E × B speeds were significantly less than the propagation speed of the pulse from MMS to the Van Allen Probes and GOES‐13, which is consistent with the MHD fast mode. There were increased fluxes of energetic electrons up to several MeV. Signatures of drift echoes and response to ULF waves also were seen. These observations demonstrate that even very weak shocks can have significant impact on the radiation belts. PMID:29104327

  5. Dayside response of the magnetosphere to a small shock compression: Van Allen Probes, Magnetospheric MultiScale, and GOES-13

    Science.gov (United States)

    Cattell, C.; Breneman, A.; Colpitts, C.; Dombeck, J.; Thaller, S.; Tian, S.; Wygant, J.; Fennell, J.; Hudson, M. K.; Ergun, Robert; Russell, C. T.; Torbert, Roy; Lindqvist, Per-Arne; Burch, J.

    2017-09-01

    Observations from Magnetospheric MultiScale ( 8 Re) and Van Allen Probes ( 5 and 4 Re) show that the initial dayside response to a small interplanetary shock is a double-peaked dawnward electric field, which is distinctly different from the usual bipolar (dawnward and then duskward) signature reported for large shocks. The associated E × B flow is radially inward. The shock compressed the magnetopause to inside 8 Re, as observed by Magnetospheric MultiScale (MMS), with a speed that is comparable to the E × B flow. The magnetopause speed and the E × B speeds were significantly less than the propagation speed of the pulse from MMS to the Van Allen Probes and GOES-13, which is consistent with the MHD fast mode. There were increased fluxes of energetic electrons up to several MeV. Signatures of drift echoes and response to ULF waves also were seen. These observations demonstrate that even very weak shocks can have significant impact on the radiation belts.

  6. Transcriptomic Analysis of Oenococcus oeni SD-2a Response to Acid Shock by RNA-Seq

    Directory of Open Access Journals (Sweden)

    Longxiang Liu

    2017-08-01

    Full Text Available Oenococcus oeni can be applied to conduct malolactic fermentation (MLF, but also is the main species growing naturally in wine. Due to the high stress tolerance, it is an interesting model for investigating acid response mechanisms. In this study, the changes in the transcriptome of O.oeni SD-2a during the adaptation period have been studied. RNA-seq was introduced for the transcriptomic analysis of O. oeni samples treated with pH 4.8 and pH 3.0 at 0 and 1 h, respectively. Gene ontology (GO and Kyoto encyclopedia of genes and genome (KEGG were performed to compare the transcriptome data between different treatments. From GO analysis, the majority of differentially expressed genes (DEGs (pH 3.0_1 h-VS-pH 4.8_1 h, pH 3.0_1 h-VS-pH 4.8_0 h, and pH 4.8_1 h-VS-pH 4.8_0 h were found to be involved in the metabolic process, catalytic activity, cellular process, and binding. KEGG analysis reveals that the most functional gene categories affected by acid are membrane transport, amino acid metabolism and carbohydrate metabolism. Some genes, like the heat shock protein Hsp20, malate transporter and malate permease, were also over-expressed in response to acid stress. In addition, a considerable proportion of gene indicate a significantly different expression in this study, are novel, which needs to be investigated further. These results provide a new viewpoint and crucial resource on the acid stress response in O. oeni.

  7. Wait or escape? Contrasting submergence tolerance strategies of Rorippa amphibia, Rorippa sylvestris and their hybrid

    NARCIS (Netherlands)

    Akman, M.; Bhikharie, A.V.; McLean, E.H.; Boonman, A.; Visser, E.J.W.; Schranz, M.E.; van Tienderen, P.H.

    2012-01-01

    Background and Aims Differential responses of closely related species to submergence can provide insight into the evolution and mechanisms of submergence tolerance. Several traits of two wetland species from habitats with contrasting flooding regimes, Rorippa amphibia and Rorippa sylvestris, as well

  8. Drought and submergence tolerance in plants

    Science.gov (United States)

    Du, Hewei; Zhou, Yufan; Oksenberg, Nir; Ronald, Pamela

    2017-11-14

    The invention provides methods of genetically modified plants to increase tolerance to drought and/or submergence. The invention additionally provides plants having increased drought and/or submergence tolerance engineered using such methods.

  9. Stepwise construction of a metabolic network in Event-B: The heat shock response.

    Science.gov (United States)

    Sanwal, Usman; Petre, Luigia; Petre, Ion

    2017-12-01

    There is a high interest in constructing large, detailed computational models for biological processes. This is often done by putting together existing submodels and adding to them extra details/knowledge. The result of such approaches is usually a model that can only answer questions on a very specific level of detail, and thus, ultimately, is of limited use. We focus instead on an approach to systematically add details to a model, with formal verification of its consistency at each step. In this way, one obtains a set of reusable models, at different levels of abstraction, to be used for different purposes depending on the question to address. We demonstrate this approach using Event-B, a computational framework introduced to develop formal specifications of distributed software systems. We first describe how to model generic metabolic networks in Event-B. Then, we apply this method for modeling the biological heat shock response in eukaryotic cells, using Event-B refinement techniques. The advantage of using Event-B consists in having refinement as an intrinsic feature; this provides as a final result not only a correct model, but a chain of models automatically linked by refinement, each of which is provably correct and reusable. This is a proof-of-concept that refinement in Event-B is suitable for biomodeling, serving for mastering biological complexity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Shock Compression Response of the Light Noble Gases: Neon and Helium

    Science.gov (United States)

    Root, Seth; Shulenburger, Luke; Cochrane, Kyle; Lopez, Andrew; Shelton, Keegan; Villalva, Jose; Mattsson, Thomas

    2015-06-01

    Understanding material behavior at extreme conditions is important to a wide range of processes in planetary astrophysics and inertial confinement fusion. Modeling the high pressure - high temperature processes requires robust equations of state (EOS). For many materials, EOS models have been developed using low-pressure Hugoniot data. Assumptions are made to extrapolate the EOS models to Mbar pressure regimes, leading to different model behavior at extreme conditions. In this work, we examine the high pressure response of the light noble gases: neon and helium in the multi-Mbar regime. We perform a series of shock compression experiments using Sandia's Z-Machine on cryogenically cooled liquids of Ne (26 K) and He (2.2 K) to measure the Hugoniot and reshock states. In parallel, we use density functional theory methods to calculate the Hugoniot and reshock states. The experiments validated the DFT simulations and the combined experimental and simulation results are used to assess the EOS models. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Securities Administration under Contract No. DE-AC04-94AL85000.

  11. Comparative shock response of additively manufactured versus conventionally wrought 304L stainless steel

    Science.gov (United States)

    Wise, J. L.; Adams, D. P.; Nishida, E. E.; Song, B.; Maguire, M. C.; Carroll, J.; Reedlunn, B.; Bishop, J. E.; Palmer, T. A.

    2017-01-01

    Gas-gun experiments have probed the compression and release behavior of impact-loaded 304L stainless steel specimens that were machined from additively manufactured (AM) blocks as well as baseline ingot-derived bar stock. The AM technology permits direct fabrication of net- or near-net-shape metal parts. For the present investigation, velocity interferometer (VISAR) diagnostics provided time-resolved measurements of sample response for one-dimensional (i.e., uniaxial strain) shock compression to peak stresses ranging from 0.2 to 7.0 GPa. The acquired wave-profile data have been analyzed to determine the comparative Hugoniot Elastic Limit (HEL), Hugoniot equation of state, spall strength, and high-pressure yield strength of the AM and conventional materials. The possible contributions of various factors, such as composition, porosity, microstructure (e.g., grain size and morphology), residual stress, and/or sample axis orientation relative to the additive manufacturing deposition trajectory, are considered to explain differences between the AM and baseline 304L dynamic material results.

  12. Experimental study of frost heaving force based on transient shock response using piezoceramic sensors

    Science.gov (United States)

    Wang, Ruolin; Peng, Tongxiao; Wang, Ming L.

    2016-04-01

    In seasonally frozen soil regions, the frost heaving problem made it difficult to monitor or evaluate the pile safety for long term. So far, no mature tool can be utilized to monitor the frost heaving force, which was unevenly distributed along the pile. In this paper, a piezoceramic sensing based transient excitation response approach was proposed to monitor the frost heaving force in real time. Freeze-thaw cycles can result in great changes of soil engineering properties, including the frost heaving force. So, the freeze-thaw cycle was repeated fourth to study its effect. In the experiment, transient horizontal shock on the top of the pile will be detected by the 6 PZT sensors glued on the pile. The signal data received by the 6 PZT sensors can be used to illustrate the frost heaving force distribution along the pile. Moisture content effect is also one of the important reasons that cause the variation of soil mechanical properties. So three different moisture content (6%, 12%, 18%) testing soil were used in this experiment to detect the variance of the frost heaving force. An energy indicator was developed to quantitatively evaluate the frost heaving force applied on the pile. The experimental results showed that the proposed method was effective in monitoring the uneven distribution of frost heaving force along the pile.

  13. Heat shock protein 90 in plants: molecular mechanisms and roles in stress responses.

    Science.gov (United States)

    Xu, Zhao-Shi; Li, Zhi-Yong; Chen, Yang; Chen, Ming; Li, Lian-Cheng; Ma, You-Zhi

    2012-11-23

    The heat shock protein 90 (Hsp90) family mediates stress signal transduction, and plays important roles in the control of normal growth of human cells and in promoting development of tumor cells. Hsp90s have become a currently important subject in cellular immunity, signal transduction, and anti-cancer research. Studies on the physiological functions of Hsp90s began much later in plants than in animals and fungi. Significant progress has been made in understanding complex mechanisms of HSP90s in plants, including ATPase-coupled conformational changes and interactions with cochaperone proteins. A wide range of signaling proteins interact with HSP90s. Recent studies revealed that plant Hsp90s are important in plant development, environmental stress response, and disease and pest resistance. In this study, the plant HSP90 family was classified into three clusters on the basis of phylogenetic relationships, gene structure, and biological functions. We discuss the molecular functions of Hsp90s, and systematically review recent progress of Hsp90 research in plants.

  14. Development of a General Shocked-Materials-Response Description for Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Steven M. Valone

    2000-07-01

    This report outlines broad modeling issues pertaining to polymeric materials behavior under detonation conditions. Models applicable system wide are necessary to cope with the broad range of polymers and complex composite forms that can appear in Laboratory weapons systems. Nine major topics are discussed to span the breadth of materials, forms, and physical phenomena encountered when shocking polymers and foams over wide ranges of temperatures, pressures, shock strengths, confinement conditions, and geometries. The recommendations for directions of more intensive investigation consider physical fidelity, computational complexity, and application over widely varying physical conditions of temperature, pressure, and shock strength.

  15. Submerged membrane distillation for desalination of water

    KAUST Repository

    Francis, Lijo

    2016-10-27

    Submerged membrane modules for use for desalination of water are disclosed. In one or more aspects, the membrane modules can be submerged either in a feed solution tank or the feed solution can pass through the lumen side of the membrane submerged within the tank. The feed solution can be a water-based feed stream containing an amount of salt.

  16. Biology of the Heat Shock Response and Protein Chaperones: Budding Yeast (Saccharomyces cerevisiae) as a Model System

    Science.gov (United States)

    Verghese, Jacob; Abrams, Jennifer; Wang, Yanyu

    2012-01-01

    Summary: The eukaryotic heat shock response is an ancient and highly conserved transcriptional program that results in the immediate synthesis of a battery of cytoprotective genes in the presence of thermal and other environmental stresses. Many of these genes encode molecular chaperones, powerful protein remodelers with the capacity to shield, fold, or unfold substrates in a context-dependent manner. The budding yeast Saccharomyces cerevisiae continues to be an invaluable model for driving the discovery of regulatory features of this fundamental stress response. In addition, budding yeast has been an outstanding model system to elucidate the cell biology of protein chaperones and their organization into functional networks. In this review, we evaluate our understanding of the multifaceted response to heat shock. In addition, the chaperone complement of the cytosol is compared to those of mitochondria and the endoplasmic reticulum, organelles with their own unique protein homeostasis milieus. Finally, we examine recent advances in the understanding of the roles of protein chaperones and the heat shock response in pathogenic fungi, which is being accelerated by the wealth of information gained for budding yeast. PMID:22688810

  17. Theoretical study of the porosity effects on the shock response of graphitic materials

    Directory of Open Access Journals (Sweden)

    Pineau Nicolas

    2015-01-01

    Full Text Available In this paper we present a theoretical study of the shock compression of porous graphite by means of combined Monte Carlo and molecular dynamics simulations using the LCBOPII potential. The results show that the Hugoniostat methods can be used with “pole” properties calculated from porous models to reproduce the experimental Hugoniot of pure graphite and diamond with good accuracy. The computed shock temperatures show a sharp increase for weak shocks which we analyze as the heating associated with the closure of the initial porosity. After this initial phase, the temperature increases with shock intensity at a rate comparable to monocrystalline graphite and diamond. These simulations data can be exploited in view to build a full equation of state for use in hydrodynamic simulations.

  18. RhoA Activation Sensitizes Cells to Proteotoxic Stimuli by Abrogating the HSF1-Dependent Heat Shock Response.

    Directory of Open Access Journals (Sweden)

    Roelien A M Meijering

    Full Text Available The heat shock response (HSR is an ancient and highly conserved program of stress-induced gene expression, aimed at reestablishing protein homeostasis to preserve cellular fitness. Cells that fail to activate or maintain this protective response are hypersensitive to proteotoxic stress. The HSR is mediated by the heat shock transcription factor 1 (HSF1, which binds to conserved heat shock elements (HSE in the promoter region of heat shock genes, resulting in the expression of heat shock proteins (HSP. Recently, we observed that hyperactivation of RhoA conditions cardiomyocytes for the cardiac arrhythmia atrial fibrillation. Also, the HSR is annihilated in atrial fibrillation, and induction of HSR mitigates sensitization of cells to this disease. Therefore, we hypothesized active RhoA to suppress the HSR resulting in sensitization of cells for proteotoxic stimuli.Stimulation of RhoA activity significantly suppressed the proteotoxic stress-induced HSR in HL-1 atrial cardiomyocytes as determined with a luciferase reporter construct driven by the HSF1 regulated human HSP70 (HSPA1A promoter and HSP protein expression by Western Blot analysis. Inversely, RhoA inhibition boosted the proteotoxic stress-induced HSR. While active RhoA did not preclude HSF1 nuclear accumulation, phosphorylation, acetylation, or sumoylation, it did impair binding of HSF1 to the hsp genes promoter element HSE. Impaired binding results in suppression of HSP expression and sensitized cells to proteotoxic stress.These results reveal that active RhoA negatively regulates the HSR via attenuation of the HSF1-HSE binding and thus may play a role in sensitizing cells to proteotoxic stimuli.

  19. Inflation Responses to Commodity Price Shocks; How and Why Do Countries Differ?

    OpenAIRE

    R. G Gelos; Yulia Ustyugova

    2012-01-01

    This paper relates the inflationary impact of commodity price shocks across countries to a broad range of structural characteristics and policy frameworks over the period 2001-2010, using several approaches. The analysis suggests that economies with higher food shares in CPI baskets, fuel intensities, and pre-existing inflation levels were more prone to experience sustained inflationary effects from commodity price shocks. Countries with more independent central banks and higher governance sc...

  20. Comparative analysis of physical stress responses in soybean seedlings using cloned heat shock cDNAs.

    Science.gov (United States)

    Czarnecka, E; Edelman, L; Schöffl, F; Key, J L

    1984-01-01

    Soybean seedlings were subjected to a wide range of physical (abiotic) or environmental stresses. Cloned cDNAs to heat shock (hs)-induced mRNAs were used to assess whether these diverse stresses induced the accumulation of poly(A)RNAs in common with those induced by hs. Northern blot hybridization analyses indicated that a wide range of stress agents lead to the accumulation of detectable levels of several of the hs-induced poly(A)RNAs; the relative concentration of those RNAs 'induced' by the wide range of stress agents (e.g. water stress, salt stress, anaerobiosis, high concentrations of hormones, etc.), was generally in the order of 100-fold lower than that induced by hs. There are two notable exceptions to that pattern of response to the stress agents. First, arsenite treatment resulted in accumulation of the 'hs poly(A)RNAs' to levels similar to those induced by hs. Cadmium also induced a somewhat normal spectrum of the 'hs poly(A)RNAs', but generally lower levels accumulated than in hs- and arsenite0treated tissues. Second, one set of poly(A)RNAs which are present at low and variable levels in control (non-stressed tissue) tissue, and which are increased some 5- to 10-fold by hs, increased in relative concentration in response to a wide range of the stress agents similarly to the response to hs. The physiological significance of the accumulation of this set of poly(A)RNAs (which translate into four electrophoretically different 27 kd proteins) is not known, but they certainly seem to serve as a monitor (or barometer) of physiological stress conditions. Cadmium treatment results in the accumulation of those same poly(A)RNAs and an additional band of higher molecular weight poly(A)RNA homologous to the same hs cDNA clone (clone pCE 54). Ethylene seems to have no obvious causal relationship to the hs response, even though hs-treated seedlings display some symptoms similar to those exhibited by ethylene-treated seedlings.

  1. Financial and monetary policy responses to oil price shocks: evidence from oil-importing and oil-exporting countries

    OpenAIRE

    Filis, George; Chatziantoniou, I.

    2014-01-01

    In this study, we investigate the financial and monetary policy responses to oil price shocks using a Structural VAR framework. We distinguish between net oil-importing and net oil-exporting countries. Since the 80s, a significant number of empirical studies have been published investigating the effect of oil prices on macroeconomic and financial variables. Most of these studies though, do not make a distinction between oil-importing and oil-exporting economies. Overall, our results indicate ...

  2. Rice SUB1A constrains remodelling of the transcriptome and metabolome during submergence to facilitate post-submergence recovery.

    Science.gov (United States)

    Locke, Anna M; Barding, Gregory A; Sathnur, Sumukh; Larive, Cynthia K; Bailey-Serres, Julia

    2017-11-02

    The rice (Oryza sativa L.) ethylene-responsive transcription factor gene SUB1A-1 confers tolerance to prolonged, complete submergence by limiting underwater elongation growth. Upon desubmergence, SUB1A-1 genotypes rapidly recover photosynthetic function and recommence development towards flowering. The underpinnings of the transition from stress amelioration to the return to homeostasis are not well known. Here, transcriptomic and metabolomic analyses were conducted to identify mechanisms by which SUB1A improves physiological function over the 24 hr following a sublethal submergence event. Evaluation of near-isogenic genotypes after submergence and over a day of reaeration demonstrated that SUB1A transiently constrains the remodelling of cellular activities associated with growth. SUB1A influenced the abundance of ca. 1,400 transcripts and had a continued impact on metabolite content, particularly free amino acids, glucose, and sucrose, throughout the recovery period. SUB1A promoted recovery of metabolic homeostasis but had limited influence on mRNAs associated with growth processes and photosynthesis. The involvement of low energy sensing during submergence and recovery was supported by dynamics in trehalose-6-phosphate and mRNAs encoding key enzymes and signalling proteins, which were modulated by SUB1A. This study provides new evidence of convergent signalling pathways critical to the rapidly reversible management of carbon and nitrogen metabolism in submergence resilient rice. © 2017 John Wiley & Sons Ltd.

  3. Theoretical insight into the heat shock response (HSR) regulation in Lactobacillus casei and L. rhamnosus.

    Science.gov (United States)

    Rossi, Franca; Zotta, Teresa; Iacumin, Lucilla; Reale, Anna

    2016-08-07

    The understanding of the heat shock response (HSR) in lactobacilli from a regulatory point of view is still limited, though an increased knowledge on the regulation of this central stress response can lead to improvements in the exploitation of these health promoting microorganisms. Therefore the aim of this in silico study, that is the first to be carried out for members of the Lactobacillus genus, was predicting how HSR influences cell functions in the food associated and probiotic species Lactobacillus casei and Lactobacillus rhamnosus. To this purpose, thirteen whole genomes of these bacteria were analyzed to identify which genes involved in HSR are present. It was found that all the genomes share 25 HSR related genes, including those encoding protein repair systems, HSR repressors, HrcA and CtsR, and the positive regulators of HSR, alternative σ factors σ(32) and σ(24). Two genes encoding a σ(70)/σ(24) factor and a Lon protease, respectively, were found only in some genomes. The localization of the HSR regulators binding sites in genomes was analyzed in order to identify regulatory relationships driving HSR in these lactobacilli. It was observed that the binding site for the HrcA repressor is found upstream of the hrcA-grpE-dnaK-dnaJ and groES-groEL gene clusters, of two hsp genes, clpE, clpL and clpP, while the CtsR repressor binding site precedes the ctsR-clpC operon, clpB, clpE and clpP. Therefore the ClpE-ClpP protease complex is dually regulated by HrcA and CtsR. Consensus sequences for the promoters recognized by the HSR alternative σ factors were defined for L. casei and L. rhamnosus and were used in whole genome searches to identify the genes that are possibly regulated by these transcription factors and whose expression level is expected to increases in HSR. The results were validated by applying the same procedure of promoter consensus generation and whole genome search to an additional 11 species representative of the main Lactobacillus

  4. Pharmacometabolomics of l-Carnitine Treatment Response Phenotypes in Patients with Septic Shock

    Science.gov (United States)

    Puskarich, Michael A.; Finkel, Michael A.; Karnovsky, Alla; Jones, Alan E.; Trexel, Julie; Harris, Brooke N.

    2015-01-01

    Rationale: Sepsis therapeutics have a poor history of success in clinical trials, due in part to the heterogeneity of enrolled patients. Pharmacometabolomics could differentiate drug response phenotypes and permit a precision medicine approach to sepsis. Objectives: To use existing serum samples from the phase 1 clinical trial of l-carnitine treatment for severe sepsis to metabolically phenotype l-carnitine responders and nonresponders. Methods: Serum samples collected before (T0) and after completion of the infusion (T24, T48) from patients randomized to either l-carnitine (12 g) or placebo for the treatment of vasopressor-dependent septic shock were assayed by untargeted 1H-nuclear magnetic resonance metabolomics. The normalized, quantified metabolite data sets of l-carnitine- and placebo-treated patients at each time point were compared by analysis of variance with post-hoc testing for multiple comparisons. Pathway analysis was performed to statistically rank metabolic networks. Measurements and Main Results: Thirty-eight metabolites were identified in all samples. Concentrations of 3-hydroxybutyrate, acetoacetate, and 3-hydroxyisovalerate were different at T0 and over time in l-carnitine-treated survivors versus nonsurvivors. Pathway analysis of pretreatment metabolites revealed that synthesis and degradation of ketone bodies had the greatest impact in differentiating l-carnitine treatment response. Analysis of all patients based on pretreatment 3-hydroxybutyrate concentration yielded distinct phenotypes. Using the T0 median 3-hydroxybutyrate level (153 μM), patients were categorized as either high or low ketone. l-Carnitine-treated low-ketone patients had greater use of carnitine as evidenced by lower post-treatment l-carnitine levels. The l-carnitine responders also had faster resolution of vasopressor requirement and a trend toward a greater improvement in mortality at 1 year (P = 0.038) compared with patients with higher 3-hydroxybutyrate. Conclusions

  5. Pharmacometabolomics of l-carnitine treatment response phenotypes in patients with septic shock.

    Science.gov (United States)

    Puskarich, Michael A; Finkel, Michael A; Karnovsky, Alla; Jones, Alan E; Trexel, Julie; Harris, Brooke N; Stringer, Kathleen A

    2015-01-01

    Sepsis therapeutics have a poor history of success in clinical trials, due in part to the heterogeneity of enrolled patients. Pharmacometabolomics could differentiate drug response phenotypes and permit a precision medicine approach to sepsis. To use existing serum samples from the phase 1 clinical trial of l-carnitine treatment for severe sepsis to metabolically phenotype l-carnitine responders and nonresponders. Serum samples collected before (T0) and after completion of the infusion (T24, T48) from patients randomized to either l-carnitine (12 g) or placebo for the treatment of vasopressor-dependent septic shock were assayed by untargeted (1)H-nuclear magnetic resonance metabolomics. The normalized, quantified metabolite data sets of l-carnitine- and placebo-treated patients at each time point were compared by analysis of variance with post-hoc testing for multiple comparisons. Pathway analysis was performed to statistically rank metabolic networks. Thirty-eight metabolites were identified in all samples. Concentrations of 3-hydroxybutyrate, acetoacetate, and 3-hydroxyisovalerate were different at T0 and over time in l-carnitine-treated survivors versus nonsurvivors. Pathway analysis of pretreatment metabolites revealed that synthesis and degradation of ketone bodies had the greatest impact in differentiating l-carnitine treatment response. Analysis of all patients based on pretreatment 3-hydroxybutyrate concentration yielded distinct phenotypes. Using the T0 median 3-hydroxybutyrate level (153 μM), patients were categorized as either high or low ketone. l-Carnitine-treated low-ketone patients had greater use of carnitine as evidenced by lower post-treatment l-carnitine levels. The l-carnitine responders also had faster resolution of vasopressor requirement and a trend toward a greater improvement in mortality at 1 year (P = 0.038) compared with patients with higher 3-hydroxybutyrate. The results of this preliminary study, which were not readily apparent from

  6. The response of stromatolites to seismic shocks: Tomboliths from the Palaeoproterozoic Chaibasa Formation, E India

    Directory of Open Access Journals (Sweden)

    A.J. (Tom van Loon

    2016-09-01

    Full Text Available It is demonstrated here for the first time how Palaeoproterozoic stromatolites survived seismic disturbance of their substrate. The stromatolites under study could have been cyanobacteria or any other photoautotrophic microbes, which formed mats that covered a substrate of very fine-grained sandstones and mudstones of the Chaibasa Fm. in eastern India. The sediments represent a shelf environment. The local abundance of the stromatolites suggests that the low-energy environment formed a suitable habitat. The common phases of tectonic quiescence were, however, occasionally interrupted by seismic shocks. These were sufficiently strong to deform the mat layers, the lower parts of which might already have been (semi- consolidated. The mats became partly folded, partly faulted, and already consolidated parts of the stromatolite layers broke off. This can be deduced from the angular shapes of part of the broken-off fragments. It appears, however, that part of these fragments were still sufficiently soft to become rounded and deformed by rolling over the seafloor, probably under the influence of tidal currents. When come to rest, these fragments served as a new substrate for new generations of the micro-organisms. These micro-organisms thus survived by continued growth on the reworked fragments and built up new stromatolites that may show an ‘angular disconformity’ with the stromatolites of their substrate. It thus is shown that stromatolites have an adequate response to a sudden disturbance of their habitat, and that they survive earthquakes by colonization of broken-off fragments. We call the ‘healed’ fragments ‘tomboliths’ (tumbled stones.

  7. Continuum dislocation-density based models for the dynamic shock response of single-crystal and polycrystalline materials

    Science.gov (United States)

    Luscher, Darby

    2017-06-01

    The dynamic thermomechanical responses of polycrystalline materials under shock loading are often dominated by the interaction of defects and interfaces. For example, polymer-bonded explosives (PBX) can initiate under weak shock impacts whose energy, if distributed homogeneously throughout the material, translates to temperature increases that are insufficient to drive the rapid chemistry observed. In such cases, heterogeneous thermomechanical interactions at the mesoscale (i.e. between single-crystal and macroscale) lead to the formation of localized hot spots. Within metals, a prescribed deformation associated with a shock wave may be accommodated by crystallographic slip, provided a sufficient population of mobile dislocations is available. However, if the deformation rate is large enough, there may be an insufficient number of freely mobile dislocations. In these cases, additional dislocations may be nucleated, or alternate mechanisms (e.g. twinning, damage) activated in order to accommodate the deformation. Direct numerical simulation at the mesoscale offers insight into these physical processes that can be invaluable to the development of macroscale constitutive theories, if the mesoscale models adequately represent the anisotropic nonlinear thermomechanical response of individual crystals and their interfaces. This talk will briefly outline a continuum mesoscale modeling framework founded upon local and nonlocal variations of dislocation-density based crystal plasticity theory. The nonlocal theory couples continuum dislocation transport with the local theory. In the latter, dislocation transport is modeled by enforcing dislocation conservation at a slip-system level through the solution of advection-diffusion equations. The configuration of geometrically necessary dislocation density gives rise to a back-stress that inhibits or accentuates the flow of dislocations. Development of the local theory and application to modeling the explosive molecular crystal

  8. mTOR is essential for the proteotoxic stress response, HSF1 activation and heat shock protein synthesis.

    Directory of Open Access Journals (Sweden)

    Shiuh-Dih Chou

    Full Text Available The target of rapamycin (TOR is a high molecular weight protein kinase that regulates many processes in cells in response to mitogens and variations in nutrient availability. Here we have shown that mTOR in human tissue culture cells plays a key role in responses to proteotoxic stress and that reduction in mTOR levels by RNA interference leads to increase sensitivity to heat shock. This effect was accompanied by a drastic reduction in ability to synthesize heat shock proteins (HSP, including Hsp70, Hsp90 and Hsp110. As HSP transcription is regulated by heat shock transcription factor 1 (HSF1, we examined whether mTOR could directly phosphorylate this factor. Indeed, we determined that mTOR could directly phosphorylate HSF1 on serine 326, a key residue in transcriptional activation. HSF1 was phosphorylated on S326 immediately after heat shock and was triggered by other cell stressors including proteasome inhibitors and sodium arsenite. Null mutation of S326 to alanine led to loss of ability to activate an HSF1-regulated promoter-reporter construct, indicating a direct role for mTOR and S326 in transcriptional regulation of HSP genes during stress. As mTOR is known to exist in at least two intracellular complexes, mTORC1 and mTOR2 we examined which complex might interact with HSF1. Indeed mTORC1 inhibitor rapamycin prevented HSF1-S326 phosphorylation, suggesting that this complex is involved in HSF1 regulation in stress. Our experiments therefore suggest a key role for mTORC1 in transcriptional responses to proteotoxic stress.

  9. Short-term heat shock affects the course of immune response in Galleria mellonella naturally infected with the entomopathogenic fungus Beauveria bassiana.

    Science.gov (United States)

    Vertyporokh, Lidiia; Taszłow, Paulina; Samorek-Pieróg, Małgorzata; Wojda, Iwona

    2015-09-01

    We aimed to investigate how exposition of infected insects to short-term heat shock affects the biochemical and molecular aspects of their immune response. Galleria mellonella larvae were exposed to 43°C for 15min, at the seventy second hour after natural infection with entomopathogenic fungus Beauveria bassiana. As a result, both qualitative and quantitative changes in hemolymph protein profiles, and among them infection-induced changes in the amount of apolipophorin III (apoLp-III), were observed. Heat shock differently affects the expression of the tested immune-related genes. It transiently inhibits expression of antifungal peptides gallerimycin and galiomicin in both the fat body and hemocytes of infected larvae. The same, although to a lesser extent, concerned apoLp-III gene expression and was observed directly after heat shock. Nevertheless, in larvae that had recovered from heat shock, apoLp-III expression was higher in comparison to unshocked larvae in the fat body but not in hemocytes, which was consistent with the higher amount of this protein detected in the hemolymph of the infected, shocked larvae. Furthermore, lysozyme-type activity was higher directly after heat shock, while antifungal activity was significantly higher also in larvae that had recovered from heat shock, in comparison to the respective values in their non-shocked, infected counterparts. These results show how changes in the external temperature modulate the immune response of G. mellonella suffering from infection with its natural pathogen B. bassiana. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Empirical Model Development for Predicting Shock Response on Composite Materials Subjected to Pyroshock Loading. Volume 2, Part 1; Appendices

    Science.gov (United States)

    Gentz, Steven J.; Ordway, David O.; Parsons, David S.; Garrison, Craig M.; Rodgers, C. Steven; Collins, Brian W.

    2015-01-01

    The NASA Engineering and Safety Center (NESC) received a request to develop an analysis model based on both frequency response and wave propagation analyses for predicting shock response spectrum (SRS) on composite materials subjected to pyroshock loading. The model would account for near-field environment (approximately 9 inches from the source) dominated by direct wave propagation, mid-field environment (approximately 2 feet from the source) characterized by wave propagation and structural resonances, and far-field environment dominated by lower frequency bending waves in the structure. This document contains appendices to the Volume I report.

  11. [Effects of light on submerged macrophytes in eutrophic water: research progress].

    Science.gov (United States)

    Li-Sha, Zou; Ze-Yu, Nie; Xiao-Yan, Yao; Ji-Yan, Shi

    2013-07-01

    The restoration of submerged macrophytes is the key to remediate eutrophic water and maintain the health of aquatic ecosystem, while light is the main limiting factor. This paper summarized the factors affecting the light extinction in water and the mechanisms of light intensity affecting the physiology of submerged macrophytes, with the focuses on the metabolic mechanisms of carbon, nitrogen, and phosphorus, the responses of antioxidant enzyme system, and the feedbacks of pigment composition and concentration in the common submerged macrophytes under low light stress. Several engineering techniques applied in the ecological restoration of submerged macrophytes were presented, and the framework of the restoration of submerged macrophytes in eutrophic water was proposed. Some problems in current research and several suggestions on future research were addressed, which could help the related research and engineering practices.

  12. Genetic responses of the marine copepod Acartia tonsa (Dana) to heat shock and epibiont infestation

    DEFF Research Database (Denmark)

    Petkeviciute, Egle; Kania, Per Walter; Skovgaard, Alf

    2015-01-01

    Expression of stress-related genes was investigated in the marine copepod Acartia tonsa in relation to heat shock at two different salinities (10 and 32‰), and it was furthermore investigated whether experimentally induced epibiont infestation led to elevated expression of stress-related genes. E...

  13. Differential heat shock response of primary human cell cultures and established cell lines

    DEFF Research Database (Denmark)

    Richter, W W; Issinger, O G

    1986-01-01

    degrees C treatment, whereas in immortalized cell lines usually 90% of the cells were found in suspension. Enhanced expression of the major heat shock protein (hsp 70) was found in all heat-treated cells. In contrast to the primary cell cultures, established and transformed cell lines synthesized...

  14. Reactive oxygen species mediate growth and death in submerged plants

    Directory of Open Access Journals (Sweden)

    Bianka eSteffens

    2013-06-01

    Full Text Available Aquatic and semi-aquatic plants are well adapted to survive partial or complete submergence which is commonly accompanied by oxygen deprivation. The gaseous hormone ethylene controls a number of adaptive responses to submergence including adventitious root growth and aerenchyma formation. Reactive oxygen species (ROS act as signaling intermediates in ethylene-controlled submergence adaptation and possibly also independent of ethylene. ROS levels are controlled by synthesis, enzymatic metabolism and nonenzymatic scavenging. While the actors are by and large known, we still have to learn about altered ROS at the subcellular level and how they are brought about, and the signaling cascades that trigger a specific response. This review briefly summarizes our knowledge on the contribution of ROS to submergence adaptation and describes spectrophotometrical, histochemical and live cell imaging detection methods that have been used to study changes in ROS abundance. Electron paramagnetic resonance (EPR spectroscopy is introduced as a method that allows identification and quantification of specific ROS in cell compartments. The use of advanced technologies such as EPR spectroscopy will be necessary to untangle the intricate and partially interwoven signaling networks of ethylene and ROS.

  15. Receptor-interacting protein 140 as a co-repressor of Heat Shock Factor 1 regulates neuronal stress response.

    Science.gov (United States)

    Lin, Yu-Lung; Tsai, Hong-Chieh; Liu, Pei-Yao; Benneyworth, Michael; Wei, Li-Na

    2017-12-12

    Heat shock response (HSR) is a highly conserved transcriptional program that protects organisms against various stressful conditions. However, the molecular mechanisms modulating HSR, especially the suppression of HSR, is poorly understood. Here, we found that RIP140, a wide-spectrum cofactor of nuclear hormone receptors, acts as a co-repressor of heat shock factor 1 (HSF1) to suppress HSR in healthy neurons. When neurons are stressed such as by heat shock or sodium arsenite (As), cells engage specific proteosome-mediated degradation to reduce RIP140 level, thereby relieving the suppression and activating HSR. RIP140 degradation requires specific Tyr-phosphorylation by Syk that is activated in stressful conditions. Lowering RIP140 level protects hippocampal neurons from As stress, significantly it increases neuron survival and improves spine density. Reducing hippocampal RIP140 in the mouse rescues chronic As-induced spatial learning deficits. This is the first study elucidating RIP140-mediated suppression of HSF1-activated HSR in neurons and brain. Importantly, degradation of RIP140 in stressed neurons relieves this suppression, allowing neurons to efficiently and timely engage HSR programs and recover. Therefore, stimulating RIP140 degradation to activate anti-stress program provides a potential preventive or therapeutic strategy for neurodegeneration diseases.

  16. Caloric restriction induces heat shock response and inhibits B16F10 cell tumorigenesis both in vitro and in vivo

    Science.gov (United States)

    Novelle, Marta G.; Davis, Ashley; Price, Nathan L.; Ali, Ahmed; Fürer-Galvan, Stefanie; Zhang, Yongqing; Becker, Kevin; Bernier, Michel; de Cabo, Rafael

    2015-01-01

    Caloric restriction (CR) without malnutrition is one of the most consistent strategies for increasing mean and maximal lifespan and delaying the onset of age-associated diseases. Stress resistance is a common trait of many long-lived mutants and life-extending interventions, including CR. Indeed, better protection against heat shock and other genotoxic insults have helped explain the pro-survival properties of CR. In this study, both in vitro and in vivo responses to heat shock were investigated using two different models of CR. Murine B16F10 melanoma cells treated with serum from CR-fed rats showed lower proliferation, increased tolerance to heat shock and enhanced HSP-70 expression, compared to serum from ad libitum-fed animals. Similar effects were observed in B16F10 cells implanted subcutaneously in male C57BL/6 mice subjected to CR. Microarray analysis identified a number of genes and pathways whose expression profile were similar in both models. These results suggest that the use of an in vitro model could be a good alternative to study the mechanisms by which CR exerts its anti-tumorigenic effects. PMID:25948793

  17. Hemorrhagic shock-induced endothelial cell activation in a spontaneous breathing and a mechanical ventilation hemorrhagic shock model is induced by a proinflammatory response and not by hypoxia

    NARCIS (Netherlands)

    Meurs, M. van; Wulfert, F.M.; Jongman, R.M.; Schipper, M.; Houwertjes, M.C.; Vaneker, M.; Scheffer, G.J.; Teppema, L.J.; Aarts, L.P.; Heeringa, P.; Zijlstra, J.G.; Molema, G.

    2011-01-01

    INTRODUCTION: The interaction between neutrophils and activated endothelium is essential for the development of multiple organ dysfunction in patients with hemorrhagic shock (HS). Mechanical ventilation frequently is used in patients with HS. The authors sought to investigate the consequences of

  18. Hemorrhagic Shock-induced Endothelial Cell Activation in a Spontaneous Breathing and a Mechanical Ventilation Hemorrhagic Shock Model Is Induced by a Proinflammatory Response and Not by Hypoxia

    NARCIS (Netherlands)

    van Meurs, Matijs; Wulfert, Francis M.; Jongman, Rianne M.; Schipper, Martin; Houwertjes, Martin C.; Vaneker, Michiel; Scheffer, Gert Jan; Teppema, Luc J.; Aarts, Leon P. H. J.; Heeringa, Peter; Zijlstra, Jan G.; Molema, Grietje

    Introduction: The interaction between neutrophils and activated endothelium is essential for the development of multiple organ dysfunction in patients with hemorrhagic shock (HS). Mechanical ventilation frequently is used in patients with HS. The authors sought to investigate the consequences of

  19. An overview on the effect of manufacturing on the shock response of polymers

    Science.gov (United States)

    Kister, Guillaume; Wood, David; Appleby-Thomas, Gareth; Roberts, Andrew; Leighs, James; Goff, Michael; Hameed, Amer

    2013-06-01

    Polymers are widely employed in areas as diverse as consumer goods and explosives (matrix materials). The consequent commercial interest has led to a continual drive to improve material properties - e.g. via either manufacturing techniques or more fundamental improvements in the understanding of the underlying chemistry. It has been shown previously that chemical compositions can affect the shock profile of the polymer Poly-Methyl Methacrylate (PMMA). To this end the composition will change over time as new formulations are brought to market, for example due to the inclusion of additives that will increase the lifetime of the product. Significantly such changes may not affect the material properties at lower strain rates. At the higher strain rates these subtle difference can lead to larger discrepancies in the shock profiles. In this study comparisons of PMMA have been made between newly sourced and ``legacy'' material studied previously in the literature.

  20. Chlamydia trachomatis and chlamydial heat shock protein 60-specific antibody and cell-mediated responses predict tubal factor infertility

    DEFF Research Database (Denmark)

    Tiitinen, A.; Surcel, H.-M.; Halttunen, M.

    2006-01-01

    BACKGROUND: To evaluate the role of Chlamydia trachomatis-induced humoral and cell-mediated immune (CMI) responses in predicting tubal factor infertility (TFI). METHODS: Blood samples were taken from 88 women with TFI and 163 control women. C. trachomatis and chlamydial heat shock protein 60 (CHSP......60)-specific immunoglobulin G (IgG) antibodies were analysed using enzyme-linked immunosorbent assay (ELISA) kits. Proliferative reactivity of peripheral blood mononuclear cells was studied in vitro against Chlamydia elementary body (EB) and recombinant CHSP60 antigens. RESULTS: C. trachomatis-specific...

  1. The clonal antibody response to Pseudomonas aeruginosa heat shock protein is highly diverse in cystic fibrosis patients

    DEFF Research Database (Denmark)

    Ulanova, M; Petersen, T D; Ciofu, O

    1997-01-01

    The GroEL protein of Pseudomonas aeruginosa belongs to the bacterial 60-65 kDa heat shock protein family. A strong antibody response to GroEL has been found in cystic fibrosis (CF) patients with chronic pulmonary infection caused by P. aeruginosa. Clonotypes of IgG1 and IgG2 antibodies against Gro...... antibody clones against GroEL. The appearance of new clones with time reflected the long duration of the chronic infection. A striking addition of new clonotypes during the observation period occurred when a new unrelated bacterium (Burkholderia cepacia) had become established as a cause of the pulmonary...

  2. Dynamic response of Cu4Zr54 metallic glass to high strain rate shock loading: plasticity, spall and atomic-level structures

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Shengnian [Los Alamos National Laboratory; Arman, Bedri [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; Cagin, Tahir [TEXAS A& M UNIV

    2009-01-01

    We investigate dynamic response of Cu{sub 46}Zr{sub 54} metallic glass under adiabatic planar shock wave loading (one-dimensional strain) wjth molecular dynamics simulations, including Hugoniot (shock) states, shock-induced plasticity and spallation. The Hugoniot states are obtained up to 60 CPa along with the von Mises shear flow strengths, and the dynamic spall strength, at different strain rates and temperatures. The spall strengths likely represent the limiting values achievable in experiments such as laser ablation. For the steady shock states, a clear elastic-plastic transition is identified (e.g., in the shock velocity-particle velocity curve), and the shear strength shows strain-softening. However, the elastic-plastic transition across the shock front displays transient stress overshoot (hardening) above the Hugoniot elastic limit followed by a relatively sluggish relaxation to the steady shock state, and the plastic shock front steepens with increasing shock strength. The local von Mises shear strain analysis is used to characterize local deformation, and the Voronoi tessellation analysis, the corresponding short-range structures at various stages of shock, release, tension and spallation. The plasticity in this glass is manifested as localized shear transformation zones and of local structure rather than thermal origin, and void nucleation occurs preferentially at the highly shear-deformed regions. The Voronoi and shear strain analyses show that the atoms with different local structures are of different shear resistances that lead to shear localization (e.g., the atoms indexed with (0,0,12,0) are most shear-resistant, and those with (0,2,8,1) are highly prone to shear flow). The dynamic changes in local structures are consistent with the observed deformation dynamics.

  3. Cardiogenic shock

    Science.gov (United States)

    Shock - cardiogenic ... electrical system of the heart (heart block) Cardiogenic shock occurs when the heart is unable to pump ... orthostatic hypotension) Weak (thready) pulse To diagnose cardiogenic shock, a catheter (tube) may be placed in the ...

  4. The heat shock protein response following eccentric exercise in human skeletal muscle is unaffected by local NSAID infusion

    DEFF Research Database (Denmark)

    Mikkelsen, U R; Paulsen, G; Schjerling, P

    2013-01-01

    Non-steroidal anti-inflammatory drugs (NSAIDs) are widely consumed in relation to pain and injuries in skeletal muscle, but may adversely affect muscle adaptation probably via inhibition of prostaglandin synthesis. Induction of heat shock proteins (HSP) represents an important adaptive response...... in muscle subjected to stress, and in several cell types including cardiac myocytes prostaglandins are important in induction of the HSP response. This study aimed to determine the influence of NSAIDs on the HSP response to eccentric exercise in human skeletal muscle. Healthy males performed 200 maximal...... eccentric contractions with each leg with intramuscular infusion of the NSAID indomethacin or placebo. Biopsies were obtained from m. vastus lateralis before and after (5, 28 hrs and 8 days) the exercise bout from both legs (NSAID vs unblocked leg) and analysed for expression of the HSPs HSP70, HSP27 and a...

  5. Molecular cloning of the heat-shock cognate 70 (Hsc70) gene from the two-spotted spider mite, Tetranychus urticae, and its expression in response to heat shock and starvation.

    Science.gov (United States)

    Shim, Jae-Kyoung; Jung, Duck-Oung; Park, Jae-Woo; Kim, Dong-Woo; Ha, Dae-Myung; Lee, Kyeong-Yeoll

    2006-01-01

    We isolated a heat shock cognate 70 (hsc70) gene from the two-spotted spider mite, Tetranychus urticae, a serious agricultural pest. The hsc70 cDNA is 2275 bp and contains a 1962 bp open reading frame. The translated amino acid sequence consists of 654 residues with a calculated molecular mass of 71,275 Da and an isoelectronic point (pI) of 5.52. It also contains the highly conserved functional motifs of the Hsp70 family. A comparison of the deduced amino acid sequence shows a high identity (81-84%) with Hsp70s/Hsc70s of insects but the highest identity is with mussel Hsc71 (86%). Northern blot hybridization indicates that the hsc70 transcript level of female adults is higher than that of male adults. We evaluated the response of hsc70 gene to stresses from temperature and starvation. The level of hsc70 mRNA was not significantly changed by heat and cold shocks nor by recovery after the shocks. However, the hsc70 mRNA level was decreased by food restriction of female mites. Analysis of nucleotide and deduced amino acid sequences of hsc70 gene from T. urticae suggests that it is a member of heat shock cognate 70 gene in the highly conserved Hsp70 family but that its expression is influenced by food restriction rather than thermal stress. This is the first molecular analysis of a heat shock protein gene in an acarid.

  6. Tissue-Type-Specific Heat-Shock Response and Immunolocalization of Class I Low-Molecular-Weight Heat-Shock Proteins in Soybean.

    Science.gov (United States)

    Jinn, T. L.; Chang, PFL.; Chen, Y. M.; Key, J. L.; Lin, C. Y.

    1997-06-01

    A monospecific polyclonal antibody was used to study the tissue-type specificity and intracellular localization of class I low-molecular-weight (LMW) heat-shock proteins (HSPs) in soybean (Glycine max) under different heat-shock regimes. In etiolated soybean seedlings, the root meristematic regions contained the highest levels of LMW HSP. No tissue-type-specific expression of class I LMW HSP was detected using the tissue-printing method. In immunolocalization studies of seedlings treated with HS (40[deg]C for 2 h) the class I LMW HSPs were found in the aggregated granular structures, which were distributed randomly in the cytoplasm and in the nucleus. When the heat shock was released, the granular structures disappeared and the class I LMW HSPs became distributed homogeneously in the cytoplasm. When the seedlings were then given a more severe heat shock following the initial 40[deg]C -> 28[deg]C treatment, a large proportion of the class I LMW HSPs that originally localized in the cytoplasm were translocated into the nucleus and nucleolus. Class I LMW HSPs may assist in the resolubilization of proteins denatured or aggregated by heat and may also participate in the restoration of organellar function after heat shock.

  7. The heat-shock response co-inducer arimoclomol protects against retinal degeneration in rhodopsin retinitis pigmentosa.

    Science.gov (United States)

    Parfitt, D A; Aguila, M; McCulley, C H; Bevilacqua, D; Mendes, H F; Athanasiou, D; Novoselov, S S; Kanuga, N; Munro, P M; Coffey, P J; Kalmar, B; Greensmith, L; Cheetham, M E

    2014-05-22

    Retinitis pigmentosa (RP) is a group of inherited diseases that cause blindness due to the progressive death of rod and cone photoreceptors in the retina. There are currently no effective treatments for RP. Inherited mutations in rhodopsin, the light-sensing protein of rod photoreceptor cells, are the most common cause of autosomal-dominant RP. The majority of mutations in rhodopsin, including the common P23H substitution, lead to protein misfolding, which is a feature in many neurodegenerative disorders. Previous studies have shown that upregulating molecular chaperone expression can delay disease progression in models of neurodegeneration. Here, we have explored the potential of the heat-shock protein co-inducer arimoclomol to ameliorate rhodopsin RP. In a cell model of P23H rod opsin RP, arimoclomol reduced P23H rod opsin aggregation and improved viability of mutant rhodopsin-expressing cells. In P23H rhodopsin transgenic rat models, pharmacological potentiation of the stress response with arimoclomol improved electroretinogram responses and prolonged photoreceptor survival, as assessed by measuring outer nuclear layer thickness in the retina. Furthermore, treated animal retinae showed improved photoreceptor outer segment structure and reduced rhodopsin aggregation compared with vehicle-treated controls. The heat-shock response (HSR) was activated in P23H retinae, and this was enhanced with arimoclomol treatment. Furthermore, the unfolded protein response (UPR), which is induced in P23H transgenic rats, was also enhanced in the retinae of arimoclomol-treated animals, suggesting that arimoclomol can potentiate the UPR as well as the HSR. These data suggest that pharmacological enhancement of cellular stress responses may be a potential treatment for rhodopsin RP and that arimoclomol could benefit diseases where ER stress is a factor.

  8. Compressional sound velocity, equation of state, and constitutive response of shock-compressed magnesium oxide

    OpenAIRE

    Duffy, Thomas S.; Ahrens, Thomas J.

    1995-01-01

    Wave profile and equation of state (EOS) data are reported for low-porosity polycrystalline magnesium oxide under shock compression. The Hugoniot equation of state between 14 and 133 GPa is U_S = 6.87(10) + 1.24(4)u_p, where the numbers in parentheses are one standard deviation uncertainties in the last digit(s). Reverse-impact wave profiles constrain the compressional sound velocity, V_p, at 10–27 GPa to ±2%. Measured V_p values are consistent with ultrasonic data extrapolated from 3 GPa. By...

  9. Flow and scour around vertical submerged structures

    Indian Academy of Sciences (India)

    Although past investigations establish the effect of various parameters on scour around vertical submerged structures for live and clear water condition, yet further studies are required to analyze the scour around group of submerged structures for various bed sediments, understand the flow physics around the group and ...

  10. Tolerance of combined submergence and salinity in the halophytic stem-succulent Tecticornia pergranulata

    DEFF Research Database (Denmark)

    Colmer, T D; Vos, H; Pedersen, Ole

    2009-01-01

    in waters of high salinity. A 'quiescence response', i.e. no shoot growth, would conserve carbohydrates, but tissue sugars still declined with time. A low K(+) : Na(+) ratio, typical for tissues of succulent halophytes, was tolerated even during prolonged submergence, as evidenced by maintenance......BACKGROUND AND AIMS: Habitats occupied by many halophytes are not only saline, but are also prone to flooding. Few studies have evaluated submergence tolerance in halophytes. METHODS: Responses to submergence, at a range of salinity levels, were studied for the halophytic stem-succulent Tecticornia...... pergranulata subsp. pergranulata (syn. Halosarcia pergranulata subsp. pergranulata). Growth and total sugars in succulent stems were assessed as a function of time after submergence. Underwater net photosynthesis, dark respiration, total sugars, glycinebetaine, Na(+), Cl(-) and K(+), in succulent stems, were...

  11. Submergence Causes Similar Carbohydrate Starvation but Faster Post-Stress Recovery than Darkness in Alternanthera philoxeroides Plants.

    Directory of Open Access Journals (Sweden)

    Xiao Qi Ye

    Full Text Available Carbon assimilation by submerged plants is greatly reduced due to low light levels. It is hypothesized that submergence reduces carbohydrate contents and that plants recover from submergence in the same way as darkness-treated plants. To test this hypothesis, the responses of plants to submergence and darkness were studied and compared. Plants of a submergence-tolerant species, Alternanthera philoxeroides, were exposed to well drained and illuminated conditions, complete submergence conditions or darkness conditions followed by a recovery growth period in a controlled experiment. The biomass maintenance and accumulation, carbohydrate content dynamics and respiration rate in the plants were assessed to quantify the carbohydrate utilization rate and regrowth. The submerged plants maintained higher chlorophyll contents, more green leaf tissue and more biomass; recovered more quickly; and accumulated more carbohydrates and biomass than darkness-treated plants. The respiration rate was continuously reduced in the same pattern under both stress conditions but was maintained at a significantly lower level in the submerged plants; the total soluble sugar and total fructan contents were decreased at approximately the same rate of decrease, reaching similar low levels, in the two stress treatments. The A. philoxeroides plants were more tolerant of submergence than darkness. The faster recovery of desubmerged plants could not be explained by the similar carbohydrate contents at the start of recovery. Other types of carbon reserves besides carbohydrates or other mechanisms such as higher post-stress photosynthetic performance might be involved.

  12. Responses of bovine lymphocytes to heat shock as modified by breed and antioxidant status.

    Science.gov (United States)

    Kamwanja, L A; Chase, C C; Gutierrez, J A; Guerriero, V; Olson, T A; Hammond, A C; Hansen, P J

    1994-02-01

    We tested whether resistance of lymphocytes to heat stress is modified by breed, intracellular glutathione content, and extracellular antioxidants. In the first experiment, lymphocytes from Angus (Bos taurus, non-heat-tolerant), Brahman (B. indicus, heat-tolerant), and Senepol (B. taurus, heat-tolerant) heifers (12 heifers per breed) were cultured at 45 degrees C for 3 h to evaluate thermal killing, at 42 degrees C for 12 h in a 60-h phytohemagglutinin-induced proliferation test, and at 42 degrees C for 1 h to measure induction of heat shock protein 70 (HSP70). Killing at 45 degrees C was affected by breed x temperature (P Senepol. For phytohemagglutinin-stimulated lymphocytes, heating to 42 degrees C reduced [3H]thymidine incorporation equally for all breeds. Viability at the end of culture was affected (P < .001) by a breed x temperature interaction because the decrease in viability caused by culture at 42 degrees C was greatest for lymphocytes from Angus heifers. Heat shock for 1 h at 42 degrees C caused a two- to threefold increase in intracellular concentrations of HSP70, but there was no interaction of temperature with breed. In another experiment (with lymphocytes harvested from three Holstein cows), buthionine sulfoximine, a glutathione synthesis inhibitor, inhibited (P < .01) proliferation of phytohemagglutinin-stimulated lymphocytes at 38.5 and 42 degrees C. Addition of the antioxidants glutathione or thioredoxin to culture did not reduce the effects of heating to 42 degrees C on proliferation.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Comparative Shock Response of Additively Manufactured Versus Conventionally Wrought 304L Stainless Steel*

    Science.gov (United States)

    Wise, J. L.; Adams, D. P.; Nishida, E. E.; Song, B.; Maguire, M. C.; Carroll, J.; Reedlunn, B.; Bishop, J. E.

    2015-06-01

    Gas-gun experiments have probed the compression and release behavior of impact-loaded 304L stainless steel specimens machined from additively manufactured (AM) blocks as well as baseline ingot-derived bar stock. The AM technology allows direct fabrication of metal parts. For the present study, a velocity interferometer (VISAR) measured the time-resolved motion of samples subjected to one-dimensional (i.e., uniaxial strain) shock compression to peak stresses ranging from 0.2 to 7.5 GPa. The acquired wave-profile data have been analyzed to determine the comparative Hugoniot Elastic Limit (HEL), Hugoniot equation of state, spall strength, and high-pressure yield strength of the AM and conventional materials. Observed differences in shock loading and unloading characteristics for the two 304L source variants have been correlated to complementary Kolsky bar results for compressive and tensile testing at lower strain rates. The effects of composition, porosity, microstructure (e.g., grain size and morphology), residual stress, and sample axis orientation relative to the additive manufacturing deposition trajectory have been assessed to explain differences between the AM and baseline 304L dynamic mechanical properties. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  14. Constitutive modeling of shock response of phase-transforming and porous materials with strength

    Science.gov (United States)

    Resnyansky, A. D.

    2010-10-01

    The paper analyzes constitutive behavior of phase-transforming materials and metal powders loaded by shock waves. A two-phase material model developed earlier is extended to the case of materials with strength. Available experimental free surface velocities of iron samples under the α-ɛ phase transition and shock velocity data for porous aluminum and copper are analyzed numerically with the present model. The phase transition hysteresis is demonstrated by numerical analysis of experimental free surface velocities. Possible role of the martensitic mechanism in the hysteresis is emphasized. The calculated anomalous Hugoniots as well as pressure equilibrium (PE) and pressure-temperature equilibrium (PTE) Hugoniots are compared with available experiments for aluminum and copper powders. It is argued that a large nonequilibrium interphase heat transfer zone for aluminum powders results in a scatter of experimental Hugoniot points between the PE and PTE Hugoniots in low pressure region. In turn, in high pressure region, the effect of strength on porous Hugoniot may increase with porosity due to an extra dissipation, which improves description of experiments for an extremely porous aluminum.

  15. Using a gel/plastic surrogate to study the biomechanical response of the head under air shock loading: a combined experimental and numerical investigation.

    Science.gov (United States)

    Zhu, Feng; Wagner, Christina; Dal Cengio Leonardi, Alessandra; Jin, Xin; Vandevord, Pamela; Chou, Clifford; Yang, King H; King, Albert I

    2012-03-01

    A combined experimental and numerical study was conducted to determine a method to elucidate the biomechanical response of a head surrogate physical model under air shock loading. In the physical experiments, a gel-filled egg-shaped skull/brain surrogate was exposed to blast overpressure in a shock tube environment, and static pressures within the shock tube and the surrogate were recorded throughout the event. A numerical model of the shock tube was developed using the Eulerian approach and validated against experimental data. An arbitrary Lagrangian-Eulerian (ALE) fluid-structure coupling algorithm was then utilized to simulate the interaction of the shock wave and the head surrogate. After model validation, a comprehensive series of parametric studies was carried out on the egg-shaped surrogate FE model to assess the effect of several key factors, such as the elastic modulus of the shell, bulk modulus of the core, head orientation, and internal sensor location, on pressure and strain responses. Results indicate that increasing the elastic modulus of the shell within the range simulated in this study led to considerable rise of the overpressures. Varying the bulk modulus of the core from 0.5 to 2.0 GPa, the overpressure had an increase of 7.2%. The curvature of the surface facing the shock wave significantly affected both the peak positive and negative pressures. Simulations of the head surrogate with the blunt end facing the advancing shock front had a higher pressure compared to the simulations with the pointed end facing the shock front. The influence of an opening (possibly mimicking anatomical apertures) on the peak pressures was evaluated using a surrogate head with a hole on the shell of the blunt end. It was revealed that the presence of the opening had little influence on the positive pressures but could affect the negative pressure evidently.

  16. Exogenous heat shock cognate protein 70 pretreatment attenuates cardiac and hepatic dysfunction with associated anti-inflammatory responses in experimental septic shock.

    Science.gov (United States)

    Hsu, Jong-Hau; Yang, Rei-Cheng; Lin, Shih-Jen; Liou, Shu-Fen; Dai, Zen-Kong; Yeh, Jwu-Lai; Wu, Jiunn-Ren

    2014-12-01

    It has been recently demonstrated that intracellular heat shock cognate protein 70 (HSC70) can be released into extracellular space with physiologic effects. However, its extracellular function in sepsis is not clear. In this study, we hypothesize that extracellular HSC70 can protect against lipopolysaccharide (LPS)-induced myocardial and hepatic dysfunction because of its anti-inflammatory actions. In Wistar rats, septic shock developed with hypotension, tachycardia, and myocardial and hepatic dysfunction at 4 h following LPS administration (10 mg/kg, i.v.). Pretreatment with recombinant bovine HSC70 (20 μg/kg, i.v.) attenuated LPS-induced hypotension and tachycardia by 21% and 23%, respectively (P shock cognate protein 70 also prevented LPS-induced hypoglycemia (217 vs. 59 mg/dL, P shock, extracellular HSC70 conveys pleiotropic protection on myocardial, hepatic, and systemic derangements, with associated inhibition of proinflammatory mediators including tumor necrosis factor α, nitric oxide, cyclooxygenase 2, and matrix metalloproteinase 9, through mitogen-activated protein kinase/nuclear factor κB signaling pathways. Therefore, extracellular HSC70 may have a promising role in the prophylactic treatment of sepsis.

  17. Treatment of textile wastewater by submerged membrane bioreactor: In vitro bioassays for the assessment of stress response elicited by raw and reclaimed wastewater.

    Science.gov (United States)

    Friha, Inès; Bradai, Mohamed; Johnson, Daniel; Hilal, Nidal; Loukil, Slim; Ben Amor, Fatma; Feki, Firas; Han, Junkuy; Isoda, Hiroko; Sayadi, Sami

    2015-09-01

    The performance of a pilot-scale membrane bioreactor (MBR) system for the treatment of textile wastewater was investigated. The MBR was continuously operated for 7 months. Very high treatment efficiencies were achieved (color, 100%; chemical oxygen demand (COD), 98%; biochemical oxygen demand (BOD5), 96%; suspended solids (SS), 100%). Furthermore, the MBR treatment efficiency was analyzed from a toxicological-risk assessment point of view, via different In vitro bioassays using Caco-2 cells, a widely used cell model in toxicological studies. Results showed that MBR treatment significantly reduced the raw textile wastewater (RTWW) cytotoxicity on Caco-2 cells by 53% for a hydraulic retention time (HRT) of 2 days. Additionally, the RTWW-induced disruption in the barrier function (BF) of the Caco-2 cell monolayer was also significantly reduced after MBR treatment under a HRT of 2 days (no disruption of BF was observed). Moreover, the effect of RTWW and treated wastewater on stress response was investigated using different stress genes: AHSA1, HSPD1, HSPA1A, HSPA5 and HSPA8. The cell exposure to RTWW significantly increased the expression of all used stress genes; interestingly, the treated wastewater (HRT 2 days) did not show any significant modulation of the stress genes. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Formation of multiple energy dispersion of H+, He+, and O+ ions in the inner magnetosphere in response to interplanetary shock

    Science.gov (United States)

    Tsuji, H.; Ebihara, Y.; Tanaka, T.

    2017-04-01

    An interplanetary (IP) shock has a large impact on magnetospheric ions. Satellite observations have shown that soon after arrival of the IP shock, overall intensity of the ions rapidly increases and multiple energy dispersion appears in an energy-time spectrogram of the ions. In order to understand the response of the magnetospheric ions to IP shock, we have performed test particle simulation under the electric and magnetic fields provided by the global magnetohydrodynamic simulation. We reconstructed the differential flux of H+, He+, and O+ ions at (7, 0, 0) Re in GSM coordinates by means of the semi-Lagrangian (phase space mapping) method. Simulation results show that the ions respond to the IP shock in two different ways. First, overall intensity of the flux gradually increases at all pitch angles. As the compressional wave propagates tailward, the magnetic field increases, which accelerates the ions due to the gyrobetatron. Second, multiple energy-time dispersion appears in the reconstructed spectrograms of the ion flux. The energy-time dispersion is caused by the ion moving toward mirror point together with tailward propagating compressional wave at off-equator. The ions are primarily accelerated by the drift betatron under the strong electric field looking dawnward. The dispersion is absent in the spectrogram of equatorially mirroring ions. The dispersion appears at higher energy for heavier ions. These features are consistent with the satellite observations. Because the acceleration depends on bounce phase, the bounce-averaged approximation is probably invalid for the ions during the interval of geomagnetic sudden commencement.Plain Language SummarySolar storm can cause a significant compression of the magnetosphere on the dayside. The compression starts at the subsolar point and propagates toward the nightside in the magnetosphere. Some ions bouncing between the Northern Hemisphere and the Southern Hemisphere are found to be accelerated selectively when the

  19. Oxygen absorption by adventitious roots promotes the survival of completely submerged terrestrial plants.

    Science.gov (United States)

    Ayi, Qiaoli; Zeng, Bo; Liu, Jianhui; Li, Siqi; van Bodegom, Peter M; Cornelissen, Johannes H C

    2016-04-10

    Flooding imposes stress upon terrestrial plants because it results in oxygen deficiency, which is considered a major problem for submerged plants. A common response of terrestrial plants to flooding is the formation of aquatic adventitious roots. Some studies have shown that adventitious roots on submerged plants are capable of absorbing water and nutrients. However, there is no experimental evidence for the possible oxygen uptake function of adventitious roots or for how important this function might be for the survival of plants during prolonged submergence. This study aims to investigate whether adventitious roots absorb oxygen from the water column, and whether this new function is beneficial to the survival of completely submerged plants. TakingAlternanthera philoxeroides(Mart.) Griseb. as a representative species, the profiling of the underwater oxygen gradient towards living and dead adventitious roots on completely submerged plants was conducted, the oxygen concentration in stem nodes with and without adventitious roots was measured, and the growth, survival and non-structural carbohydrate content of completely submerged plants with and without adventitious roots was investigated. Oxygen profiles in the water column of adventitious roots showed that adventitious roots absorbed oxygen from water. It is found that the oxygen concentration in stem nodes having adventitious roots was higher than that in stem nodes without adventitious roots, which implies that the oxygen absorbed by adventitious roots from water was subsequently transported from the roots to other plant tissues. Compared with plants whose adventitious roots had been pruned, those with intact adventitious roots had slower leaf shedding, slower plant mass reduction, more efficient carbohydrate economy and prolonged survival when completely submerged. The adventitious roots ofA. philoxeroidesformed upon submergence can absorb oxygen from ambient water, thereby alleviating the adverse effects of

  20. Stress Responses of Small Heat Shock Protein Genes in Lepidoptera Point to Limited Conservation of Function across Phylogeny.

    Science.gov (United States)

    Zhang, Bo; Zheng, Jincheng; Peng, Yu; Liu, Xiaoxia; Hoffmann, Ary A; Ma, Chun-Sen

    2015-01-01

    The small heat shock protein (sHsp) family is thought to play an important role in protein refolding and signal transduction, and thereby protect organisms from stress. However little is known about sHsp function and conservation across phylogenies. In the current study, we provide a comprehensive assessment of small Hsp genes and their stress responses in the oriental fruit moth (OFM), Grapholita molesta. Fourteen small heat shock proteins of OFM clustered with related Hsps in other Lepidoptera despite a high level of variability among them, and in contrast to the highly conserved Hsp11.1. The only known lepidopteran sHsp ortholog (Hsp21.3) was consistently unaffected under thermal stress in Lepidoptera where it has been characterized. However the phylogenetic position of the sHsps within the Lepidoptera was not associated with conservation of induction patterns under thermal extremes or diapause. These findings suggest that the sHsps have evolved rapidly to develop new functions within the Lepidoptera.

  1. Stress Responses of Small Heat Shock Protein Genes in Lepidoptera Point to Limited Conservation of Function across Phylogeny.

    Directory of Open Access Journals (Sweden)

    Bo Zhang

    Full Text Available The small heat shock protein (sHsp family is thought to play an important role in protein refolding and signal transduction, and thereby protect organisms from stress. However little is known about sHsp function and conservation across phylogenies. In the current study, we provide a comprehensive assessment of small Hsp genes and their stress responses in the oriental fruit moth (OFM, Grapholita molesta. Fourteen small heat shock proteins of OFM clustered with related Hsps in other Lepidoptera despite a high level of variability among them, and in contrast to the highly conserved Hsp11.1. The only known lepidopteran sHsp ortholog (Hsp21.3 was consistently unaffected under thermal stress in Lepidoptera where it has been characterized. However the phylogenetic position of the sHsps within the Lepidoptera was not associated with conservation of induction patterns under thermal extremes or diapause. These findings suggest that the sHsps have evolved rapidly to develop new functions within the Lepidoptera.

  2. Response of beryllium to severe thermal shocks -simulation of disruption and vertical displacement events in future thermonuclear devices

    Energy Technology Data Exchange (ETDEWEB)

    Linke, J.; Duwe, R.; Roedig, M.; Schuster, A. [Association Euratom-Forschungszentrum Juelich GmbH (Germany); Merola, M.; Qian, R.H.

    1998-01-01

    Beryllium will play an important role for plasma facing components in next step thermonuclear fusion devices such as ITER. In particular for the first wall beryllium will be used with an armor thickness of several millimeters. However, during plasma instabilities they will experience severe thermal shocks. Here plasma disruptions with deposited energy densities of several ten MJm{sup -2} are the most essential damaging mechanism. However, a signifant fraction of the incident energy will be absorbed by a dense cloud of ablation vapor, hence reducing the effective energy density at the beryllium surface to values in the order of 10 MJm{sup -2}. To investigate the material response to all these plasma instabilities thermal shock tests on small scale test coupons (disruption effects) and on actively cooled divertor modules (VDEs) have been performed in the electron beam test facility JUDITH at ITER relevant surface heat loads. These tests have been performed on different bulk beryllium grades and on plasma sprayed coatings; the influence of pulse duration, power density, and temperature effects has been investigated experimentally. Detailed in-situ diagnostics (for beam characterization, optical pyrometry etc.) and post mortem analyses (profilometry, metallography, optical and electron microscopy) have been applied to quantify the resulting material damage. 1D- and 2D models have developed to verify the experimental results obtained in the electron beam simulation experiments. (J.P.N.)

  3. Variation in Hsp70 levels after cold shock: signs of evolutionary responses to thermal selection among Leptinotarsa decemlineata populations.

    Directory of Open Access Journals (Sweden)

    Anne Lyytinen

    Full Text Available Individuals of widely spread species are expected to show local adaption in temperature tolerance as they encounter a range of thermal conditions. We tracked thermal adaptations of the Colorado potato beetle (Leptinotarsa decemlineata that invaded Europe within the last 100 years. It has occupied various conditions although, like the majority of invasive species, it lost a measurable amount of neutral genetic variation due to bottleneck effect when it invaded Europe. We exposed diapausing beetles originated from three different latitudes (54°N, 59°N, 60°N to cold shock (-5°C, 1.5 hrs in order to test if beetles from the northern populations express differential levels of cold-induced and constitutive Hsp70 compared to the beetles from milder temperature regime. The level of cold-induced Hsp70 was lowest in the northernmost beetle populations while the level of constitutive Hsp70 did not differ with the population. Moreover, the southernmost beetles were more plastic in their response to cold shock than the northernmost beetles. These results suggest that physiological adaptation, like the synthesis of Hsp70, can evolve very quickly.

  4. Angiotensin II AT1 receptor blockade abolishes brain microvascular inflammation and heat shock protein responses in hypertensive rats.

    Science.gov (United States)

    Zhou, Jin; Ando, Hiromichi; Macova, Miroslava; Dou, Jingtao; Saavedra, Juan M

    2005-07-01

    Endothelial dysfunction and inflammation enhance vulnerability to hypertensive brain damage. To explore the participation of Angiotensin II (Ang II) in the mechanism of vulnerability to cerebral ischemia during hypertension, we examined the expression of inflammatory factors and the heat shock protein (HSP) response in cerebral microvessels from spontaneously hypertensive rats and their normotensive controls, Wistar Kyoto rats. We treated animals with vehicle or the Ang II AT(1) receptor antagonist candesartan, 0.3 mg/kg/day, via subcutaneously implanted osmotic minipumps for 4 weeks. Spontaneously hypertensive rats expressed higher Angiotensin II AT(1) receptor protein and mRNA than normotensive controls. Candesartan decreased the macrophage infiltration and reversed the enhanced tumor necrosis factor-alpha and interleukin-1beta mRNA and nuclear factor-kappaB in microvessels in hypertensive rats. The transcription of many HSP family genes, including HSP60, HSP70 and HSP90, and heat shock factor-1 was higher in hypertensive rats and was downregulated by AT(1) receptor blockade. Our results suggest a proinflammatory action of Ang II through AT(1) receptor stimulation in cerebral microvessels during hypertension, and very potent antiinflammatory effects of the Ang II AT(1) receptor antagonist. These compounds might be considered as potential therapeutic agents against ischemic and inflammatory diseases of the brain.

  5. Modeling and experimental investigations of the shock response of viscoelastic foams

    Science.gov (United States)

    Deigan, Richard J.

    This dissertation presents a new constitutive model for closed-cell foams tailored for compressive shock loads and an experimental investigation of two commercial foam products. The new model requires just two characterization experiments to find material parameters, making it far more convenient than other approaches. A specific form of the hyperelastic free energy function is developed that permits an extension of a three-phase composite theory to finite strain hyperelasticity providing the following advantages: (1) identification of the hyperelastic free energy contributions associated with the gas and material phases, (2) elimination of deviatoric experiments for parameter determination, and (3) proper behavior at the densification limit. A viscoelastic model of the matrix shear modulus is used to introduce rate effects and plasticity. A time-incremental formulation of the constitutive model is developed and implemented using a finite element approach. Model results are compared with data obtained in high strain-rate experiments.

  6. Real-time characterization of the neuronal response to osmotic shock by digital holographic microscopy

    Science.gov (United States)

    Gomariz, Maria; Garcia, Isabel; Soto-Sánchez, Cristina; Martínez-Navarrete, Gema; Fernández, Eduardo; Fimia, Antonio

    2015-05-01

    Digital holographic microscopy has numerous applications in biology for visualizing living cells and 3D tissues. This technique allows for the direct visualization of biological structures avoiding invasive and phototoxic procedures such as fixation and dying processing. In this study we have characterized the morphometry changes of neurons subject to osmolarity changes. For this purpose, we have measured the variations of the amplitude and the oscillation frequency of the plasmatic membrane, as well as the volume changes of the cells before the osmotic shock. There was a relation between the neural culture ageing and its behavioral changes. "Long-term" cultures that had not previously been studied were used to analyze the behavioral changes in aged cells.

  7. Characterization of the adaptive response and growth upon hyperosmotic shock in Saccharomyces cerevisiae.

    Science.gov (United States)

    Parmar, Jignesh H; Bhartiya, Sharad; Venkatesh, K V

    2011-04-01

    Molecular and physiological details of osmoadaptation in yeast Saccharomyces cerevisiae are well characterized. It is well known that a cell, upon osmotic shock, delays its growth, produces a compatible solute like glycerol in yeast to maintain the osmotic equilibrium. Many genes are regulated by the hyperosmolarity glycerol (HOG) singling pathway, some of which in turn control the carbon flux in the glycolytic pathway for glycerol synthesis and reduced growth. The whole process of survival of cells under hyperosmotic stress is controlled at multiple levels in signaling and metabolic pathways. To better understand the multi-level regulations in yeast to osmotic shock, a mathematical model is formulated which integrates the growth and the osmoadaptation process. The model included the HOG pathway which consists of Sho1 and Sln1 signaling branches, gene regulation, metabolism and cell growth on glucose and ethanol. Experiments were performed to characterize the effect of various concentrations of salt on the wild-type and mutant strains. The model was able to successfully predict the experimental observations for both the wild-type and mutant strains. Further, the model was used to analyze the effects of various regulatory mechanisms prevalent in the signaling and metabolic pathways which are essential in achieving optimum growth in a saline medium. The analysis demonstrated the relevance of the combined effects of regulation at several points in the signaling and metabolic pathways including activation of GPD1 and GPD2, inhibition of PYK and PDC1, closure of the Fps1 channel, volume effect on the glucose uptake rate, downregulation of ethanol synthesis and upregulation of ALD6 for acetate synthesis. The analysis demonstrated that these combined effects orchestrated the phenomena of adaptation to osmotic stress in yeast.

  8. Measurement of Submerged Oil/Gas Leaks using ROV Video

    Science.gov (United States)

    Shaffer, Franklin; de Vera, Giorgio; Lee, Kenneth; Savas, Ömer

    2013-11-01

    Drilling for oil or gas in the Gulf of Mexico is increasing rapidly at depths up to three miles. The National Commission on the Deepwater Horizon Oil Leak concluded that inaccurate estimates of the leak rate from the Deepwater Horizon caused an inadequate response and attempts to cap the leak to fail. The first response to a submerged oil/gas leak will be to send a Remotely Operated Vehicle (ROV) down to view the leak. During the response to the Deepwater Horizon crisis, the authors Savas and Shaffer were members of the Flow Rate Technical Group's Plume Team who used ROV video to develop the FRTG's first official estimates of the oil leak rate. Savas and Shaffer developed an approach using the larger, faster jet features (e.g., turbulent eddies, vortices, entrained particles) in the near-field developing zone to measure discharge rates. The authors have since used the Berkeley Tow Tank to test this approach on submerged dye-colored water jets and compressed air jets. Image Correlation Velocimetry has been applied to measure the velocity of visible features. Results from tests in the Berkeley Tow Tank and submerged oil jets in the OHMSETT facility will be presented.

  9. [Pathophysiology of hemorragic shock].

    Science.gov (United States)

    Copotoiu, R; Cinca, E; Collange, O; Levy, F; Mertes, P-M

    2016-11-01

    This review addresses the pathophysiology of hemorrhagic shock, a condition produced by rapid and significant loss of intravascular volume, which may lead to hemodynamic instability, decreases in oxygen delivery, decreased tissue perfusion, cellular hypoxia, organ damage, and death. The initial neuroendocrine response is mainly a sympathetic activation. Haemorrhagic shock is associated altered microcirculatory permeability and visceral injury. It is also responsible for a complex inflammatory response associated with hemostasis alteration. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  10. Iodine Removal Efficiency in Non-Submerged and Submerged Self-Priming Venturi Scrubber

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Majid; Yan, Changqi; Sun, Zhongning; Gu, Haifeng; Wang, Junlong; Mehboob; Khurram [Harbin Engineering Univ., Harbin (China)

    2013-04-15

    The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate (Na{sub 2}S{sub 2}O{sub 3}) in water to remove the gaseous iodine (I{sub 2}) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of 0.99±0.001 has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber.

  11. IODINE REMOVAL EFFICIENCY IN NON-SUBMERGED AND SUBMERGED SELF-PRIMING VENTURI SCRUBBER

    Directory of Open Access Journals (Sweden)

    MAJID ALI

    2013-04-01

    Full Text Available The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH and sodium thiosulphate (Na2S2O3 in water to remove the gaseous iodine (I2 from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of 0.99±0.001 has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber.

  12. Correlation of the hypotonic shock response and extent of shape change with the new ThromboLUX ™.

    Science.gov (United States)

    Kraemer, L; Raczat, T; Weiss, D R; Strobel, J; Eckstein, R; Ringwald, J

    2015-08-01

    ThromboLUX (TLX)-Score was compared with hypotonic shock response (HSR) and extent of shape change (ESC) in 99 samples from 42 platelet concentrates. Tests were performed in parallel and duplicate. Mean values for TLX Score, HSR and ESC were 30.3 ± 3.8%, 69.0 ± 12.2% and 23.2 ± 4.9%, respectively. We found no significant correlation between TLX Score and HSR or ESC (r = -0.158, P = 0.118 and r = -115, P = 0.255, respectively), whereas HSR and ESC correlated significantly (r = 0.351, P < 0.001). As TLX Score did not show significant correlation with HSR and ESC, the value of TLX for platelet quality testing remains unclear. Studies comparing these parameters with transfusion outcome are needed. © 2015 International Society of Blood Transfusion.

  13. Generalized Magneto-thermo-microstretch Response of a Half-space with Temperature-dependent Properties During Thermal Shock

    Directory of Open Access Journals (Sweden)

    Qi-lin Xiong

    Full Text Available Abstract The generalized magneto-thermoelastic problem of an infinite homogeneous isotropic microstretch half-space with temperature-dependent material properties placed in a transverse magnetic field is investigated in the context of different generalized thermoelastic theories. The upper surface of the half-space is subjected to a zonal time-dependent heat shock. By solving finite element governing equations, the solution to the problem is obtained, from which the transient magneto-thermoelastic responses, including temperature, stresses, displacements, microstretch, microrotation, induced magnetic field and induced electric field are presented graphically. Comparisons are made in the results obtained under different generalized thermoelastic theories to show some unique features of generalized thermoelasticity, and comparisons are made in the results obtained under three forms of temperature dependent material properties (absolute temperature dependent, reference temperature dependent and temperature-independent to show the effects of absolute temperature and reference temperature. Weibull or Log-normal.

  14. Development of Submerged Entry Nozzles that Resist Clogging

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Jeffrey D. Smith; Kent D. Peasle

    2002-10-14

    Accretion formation and the associated clogging of SENs is a major problem for the steel industry leading to decreased strand speed, premature changing of SENs or strand termination and the associated reductions in productivity, consistency, and steel quality. A program to evaluate potentially clog resistance materials was initiated at the University of Missouri-Rolla. The main objective of the research effort was to identify combinations of steelmaking and refractory practices that would yield improved accretion resistance for tundish nozzles and submerged entry nozzles. A number of tasks were identified during the initial kick-off meeting and each was completed with two exceptions, the thermal shock validation and the industrial trials. Not completing these two tasks related to not having access to industrial scale production facilities. Though much of the results and information generated in the project is of proprietary nature.

  15. Nosography of systemic inflammatory response syndrome, sepsis, severe sepsis, septic shock, and multiple organ dysfunction syndrome in internal medicine patients

    Directory of Open Access Journals (Sweden)

    Silvia Spoto

    2015-09-01

    Full Text Available Sepsis is defined by the presence of at least two systemic inflammatory response syndrome criteria associated with an infection microbiologically or clinically evidenced. In Italy sepsis is responsible for 80,000 hospital admissions per year and, in the last decades, severe sepsis and septic shock cases are increasing, in correlation with the increased prevalence of multi-drugresistant microbial strains. The predominant etiologic agents are Gram-positive and Gram-negative bacteria, but sepsis caused by fungi is increasing. The host response with both inflammatory and anti-inflammatory processes is responsible for organic failures, which complicate the syndrome, and for the susceptibility to secondary infections. The impairment of one or more organs or systems may be the onset clinical presentation. The organ dysfunctions complicating sepsis involve mainly cardiorespiratory system, kidneys, hemostatis and central nervous system. Fever or hypothermia, tachycardia, tachypnea, leukocytosis or leukopenia, elevated blood levels of lactate and procalcitonin, hypotension are diagnostically sensitive findings for sepsis. Definitive diagnosis requires isolation of the pathogen from blood sample or from the focus of infection. Therapeutic success against sepsis depends on the appropriate use of antibiotics, on the treatment of hemodynamic and respiratory disorder and on general supportive care. In some cases the use of activated protein C is to take in consideration.

  16. Aquatic adventitious root development in partially and completely submerged wetland plants Cotula coronopifolia and Meionectes brownii.

    Science.gov (United States)

    Rich, Sarah Meghan; Ludwig, Martha; Colmer, Timothy David

    2012-07-01

    A common response of wetland plants to flooding is the formation of aquatic adventitious roots. Observations of aquatic root growth are widespread; however, controlled studies of aquatic roots of terrestrial herbaceous species are scarce. Submergence tolerance and aquatic root growth and physiology were evaluated in two herbaceous, perennial wetland species Cotula coronopifolia and Meionectes brownii. Plants were raised in large pots with 'sediment' roots in nutrient solution and then placed into individual tanks and shoots were left in air or submerged (completely or partially). The effects on growth of aquatic root removal, and of light availability to submerged plant organs, were evaluated. Responses of aquatic root porosity, chlorophyll and underwater photosynthesis, were studied. Both species tolerated 4 weeks of complete or partial submergence. Extensive, photosynthetically active, aquatic adventitious roots grew from submerged stems and contributed up to 90 % of the total root dry mass. When aquatic roots were pruned, completely submerged plants grew less and had lower stem and leaf chlorophyll a, as compared with controls with intact roots. Roots exposed to the lowest PAR (daily mean 4.7 ± 2.4 µmol m(-2) s(-1)) under water contained less chlorophyll, but there was no difference in aquatic root biomass after 4 weeks, regardless of light availability in the water column (high PAR was available to all emergent shoots). Both M. brownii and C. coronopifolia responded to submergence with growth of aquatic adventitious roots, which essentially replaced the existing sediment root system. These aquatic roots contained chlorophyll and were photosynthetically active. Removal of aquatic roots had negative effects on plant growth during partial and complete submergence.

  17. EU emissions trading. The need for cap adjustment in response to external shocks and unexpected developments?

    Energy Technology Data Exchange (ETDEWEB)

    Diekmann, Jochen [DIW, Berlin (Germany)

    2012-11-15

    In this paper the advantages and disadvantages of the various adaptation options will be discussed from an economic perspective. Firstly, the criteria for identifying a need for potentially legitimate adaptation should be investigated. Furthermore, the issue of appropriate timely intervention points prior to or within the trading period will be discussed. In what periods and scenarios are adjustments to the cap worthwhile from an economic perspective? To what extent could minimum prices or price ranges make sense? What role could a strategic reserve play? By addressing these issues, it will be fundamentally discussed as to how the emissions trading scheme could be further developed and strengthened by greater flexibility. After a brief characterisation of emissions trading in theory and practice in Chapter 2, Chapter 3 will identify potential external shocks and unexpected developments which may impair the functioning of an emissions trading scheme. The current problems of cap setting for the third trading period of the EU ETS will be described in Chapter 4. Against this background, cap adjustments will be discussed in Chapter 5, minimum and maximum prices in Chapter 6 and strategic reserves in emissions trading in Chapter 7. The conclusions are summarised in Chapter 8.

  18. Heat Shock Response Associated with Hepatocarcinogenesis in a Murine Model of Hereditary Tyrosinemia Type I

    Energy Technology Data Exchange (ETDEWEB)

    Angileri, Francesca; Morrow, Geneviève; Roy, Vincent; Orejuela, Diana; Tanguay, Robert M., E-mail: robert.tanguay@ibis.ulaval.ca [Laboratory of Cell and Developmental Genetics, Department of Molecular Biology, Medical Biochemistry and Pathology, Institut de Biologie Intégrative et des Systèmes (IBIS) and PROTEO, 1030 avenue de la médecine, Université Laval, Québec G1V 0A6 (Canada)

    2014-04-23

    Hereditary Tyrosinemia type 1 (HT1) is a metabolic liver disease caused by genetic defects of fumarylacetoacetate hydrolase (FAH), an enzyme necessary to complete the breakdown of tyrosine. The severe hepatic dysfunction caused by the lack of this enzyme is prevented by the therapeutic use of NTBC (2-[2-nitro-4-(trifluoromethyl)benzoyl]cyclohexane-1,3-dione). However despite the treatment, chronic hepatopathy and development of hepatocellular carcinoma (HCC) are still observed in some HT1 patients. Growing evidence show the important role of heat shock proteins (HSPs) in many cellular processes and their involvement in pathological diseases including cancer. Their survival-promoting effect by modulation of the apoptotic machinery is often correlated with poor prognosis and resistance to therapy in a number of cancers. Here, we sought to gain insight into the pathophysiological mechanisms associated with liver dysfunction and tumor development in a murine model of HT1. Differential gene expression patterns in livers of mice under HT1 stress, induced by drug retrieval, have shown deregulation of stress and cell death resistance genes. Among them, genes coding for HSPB and HSPA members, and for anti-apoptotic BCL-2 related mitochondrial proteins were associated with the hepatocarcinogenetic process. Our data highlight the variation of stress pathways related to HT1 hepatocarcinogenesis suggesting the role of HSPs in rendering tyrosinemia-affected liver susceptible to the development of HCC.

  19. Schistosoma mansoni heat shock protein 70 elicits an early humoral immune response in S. mansoni infected baboons

    Directory of Open Access Journals (Sweden)

    Herminia Y Kanamura

    2002-07-01

    Full Text Available A study was undertaken to search for DNA recombinant Schistosoma mansoni proteins responsible for eliciting an antibody response from the host at a very early phase after infection. A S. mansoni adult worm cDNA expression library was screened using pooled sera from baboons with four weeks of infection. Based on their specific reactivity with the S. mansoni infected sera and no reactivity when tested against the pre-infection sera from the same baboons, four clones were selected for further studies. Sequence analysis revealed that they were homologous to the S. mansoni heat shock protein 70 (hsp70. The insert sizes of the four selected clones varied from 1150 to 2006 bp. The preliminary characterization for antibody reactivity against a panel of baboon sera showed that the longest clone was the most reactive, eight out of eight acute and three out of four chronic sera reacting positively to this clone. The shortest clone was the least reactive. Our results suggest that the S. mansoni hsp70 elicits an early and strong antibody response in baboons and that antibodies to this protein can be detected in chronically infected animals. Therefore S. mansoni hsp70 may be a valid target for immunodiagnosis. However further studies are needed to identify the portion of the hsp70 that best fits the requirements for a valuable diagnostic antigen.

  20. Shock response of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX): The C-N bond scission studied by molecular dynamics simulations

    Science.gov (United States)

    Yuan, Jiao-Nan; Wei, Yong-Kai; Zhang, Xiu-Qing; Chen, Xiang-Rong; Ji, Guang-Fu; Kotni, Meena Kumari; Wei, Dong-Qing

    2017-10-01

    The shock response has a great influence on the design, synthesis, and application of energetic materials in both industrial and military areas. Therefore, the initial decomposition mechanism of bond scission at the atomistic level of condensed-phase α-RDX under shock loading has been studied based on quantum molecular dynamics simulations in combination with a multi-scale shock technique. First, based on the frontier molecular orbital theory, our calculated result shows that the N-NO2 bond is the weakest bond in the α-RDX molecule in the ground state, which may be the initial bond for pyrolysis. Second, the changes of bonds under shock loading are investigated by the changes of structures, kinetic bond lengths, and Laplacian bond orders during the simulation. Also, the variation of thermodynamic properties with time in shocked α-RDX at 10 km/s along the lattice vector a for a timescale of up to 3.5 ps is presented. By analyzing the detailed structural changes of RDX under shock loading, we find that the shocked RDX crystal undergoes a process of compression and rotation, which leads to the C-N bond initial rupture. The time variation of dynamic bond lengths in a shocked RDX crystal is calculated, and the result indicates that the C-N bond is easier to rupture than other bonds. The Laplacian bond orders are used to predict the molecular reactivity and stability. The values of the calculated bond orders show that the C-N bonds are more sensitive than other bonds under shock loading. In a word, the C-N bond scission has been validated as the initial decomposition in a RDX crystal shocked at 10 km/s. Finally, the bond-length criterion has been used to identify individual molecules in the simulation. The distance thresholds up to which two particles are considered direct neighbors and assigned to the same cluster have been tested. The species and density numbers of the initial decomposition products are collected according to the trajectory.

  1. HLA-DR polymorphisms influence in vivo responses to staphylococcal toxic shock syndrome toxin-1 in a transgenic mouse model.

    Science.gov (United States)

    Krogman, A; Tilahun, A; David, C S; Chowdhary, V R; Alexander, M P; Rajagopalan, G

    2017-01-01

    Toxic shock syndrome toxin-1 (TSST-1) is a potent superantigen produced by Staphylococcus aureus. In addition to menstrual and nonmenstrual toxic shock syndromes, TSST-1 is also implicated in the immunopathogenesis of pneumonia, infective endocarditis, neonatal exanthematous disease, and atopic dermatitis among others. Superantigens first bind to major histocompatibility complex (MHC) class II molecules and then activate a large proportion of T cells by cross-linking their T cell receptor. As binding to MHC class II molecules is a critical step in the robust activation of the immune system by TSST-1 and other superantigens, polymorphic variations between different HLA-DR alleles could potentially influence the magnitude of immune activation and immunopathology caused by TSST-1. As TSST-1 is highly toxic to humans and given that multiple variations of alleles of HLA-DR and HLA-DQ are expressed in each individual, it is difficult to determine how HLA-DR polymorphisms quantitatively and qualitatively impact immune activation caused by TSST-1 in humans. However, such investigations can be conducted on transgenic mice lacking all endogenous MHC class II molecules and expressing specific HLA class II alleles. Therefore, transgenic mice expressing different HLA-DRB1 alleles (HLA-DRB1*15:01, HLA-DRB1*15:02, HLA-DRB1*03:01, HLA-DRB1*04:01), and sharing HLA-A1*01:01 chain, were systemically challenged with purified TSST-1 and multiple immune parameters were assessed. Among the HLA-DR alleles, mice expressing HLA-DRB1*15:01 allele elicited a significantly higher serum cytokine/chemokine response; greater splenic T cell expansion and most severe organ pathology. Our study highlights the potential utility of human leukocyte antigen (HLA) transgenic mice in understanding the impact of HLA polymorphisms on the outcomes of diseases caused by TSST-1 and other superantigens. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Responsibility of a Filament Eruption for the Initiation of a Flare, CME, and Blast Wave, and its Possible Transformation into a Bow Shock

    Science.gov (United States)

    Grechnev, V. V.; Uralov, A. M.; Kuzmenko, I. V.; Kochanov, A. A.; Chertok, I. M.; Kalashnikov, S. S.

    2015-01-01

    Multi-instrument observations of two filament eruptions on 24 February and 11 May 2011 suggest the following updated scenario for eruptive flare, coronal mass ejection (CME), and shock wave evolution. An initial destabilization of a filament results in stretching out of the magnetic threads belonging to its body that are rooted in the photosphere along the inversion line. Their reconnection leads to i) heating of parts of the filament or its environment, ii) an initial development of the flare cusp, arcade, and ribbons, iii) an increasing similarity of the filament to a curved flux rope, and iv) to its acceleration. Then the pre-eruption arcade enveloping the filament becomes involved in reconnection according to the standard model and continues to form the flare arcade and ribbons. The poloidal magnetic flux in the curved rope developing from the filament progressively increases and forces its toroidal expansion. This flux rope impulsively expands and produces a magnetohydrodynamical disturbance, which rapidly steepens into a shock. The shock passes through the arcade that expands above the filament and then freely propagates for some time ahead of the CME like a decelerating blast wave. If the CME is slow, then the shock eventually decays. Otherwise, the frontal part of the shock changes into the bow-shock regime. This was observed for the first time in the 24 February 2011 event. When reconnection ceases, the flux rope relaxes and constitutes the CME core-cavity system. The expanding arcade develops into the CME frontal structure. We also found that reconnection in the current sheet of a remote streamer forced by the shock passage results in a running flare-like process within the streamer responsible for a type II burst. The development of dimming and various associated phenomena are discussed.

  3. Cytosol-Localized Heat Shock Factor-Binding Protein, AtHSBP, Functions as a Negative Regulator of Heat Shock Response by Translocation to the Nucleus and Is Required for Seed Development in Arabidopsis1[C][W][OA

    Science.gov (United States)

    Hsu, Shih-Feng; Lai, Hui-Chuan; Jinn, Tsung-Luo

    2010-01-01

    Heat shock response (HSR) is a universal mechanism in all organisms. It is under tight regulation by heat shock factors (HSFs) and heat shock proteins (HSPs) after heat shock (HS) to prevent stress damage. On the attenuation of HSR, HSP70 and HSF Binding Protein1 (HSBP1) interact with HSF1 and thus dissociate trimeric HSF1 into an inert monomeric form in humans. However, little is known about the effect of HSBP with thermal stress in plants. This report describes our investigation of the role of AtHSBP in Arabidopsis (Arabidopsis thaliana) by genetic and molecular approaches. AtHSBP was heat inducible and ubiquitously expressed in all tissues; AtHSBP was also crucial for seed development, as demonstrated by AtHSBP-knockout lines showing seed abortion. Thermotolerance results showed that AtHSBP participates in acquired thermotolerance but not basal thermotolerance and is a negative regulator of HSR. Subcellular localization revealed that the cytosol-localized AtHSBP translocated to the nucleus in response to HS. Protoplast two-hybrid assay results confirmed that AtHSBP interacts with itself and with the HSFs, AtHSFA1a, AtHSFA1b, and AtHSFA2. AtHSBP also negatively affected AtHSFA1b DNA-binding capacity in vitro. Quantitative polymerase chain reaction and western-blot analysis demonstrated that altered levels of AtHSBP lead to differential HSP expression, mainly during the recovery from HS. These studies provide a new insight into HSBP in plants and reveal that AtHSBP is a negative regulator of HSR and required for seed development. PMID:20388662

  4. Cytosol-localized heat shock factor-binding protein, AtHSBP, functions as a negative regulator of heat shock response by translocation to the nucleus and is required for seed development in Arabidopsis.

    Science.gov (United States)

    Hsu, Shih-Feng; Lai, Hui-Chuan; Jinn, Tsung-Luo

    2010-06-01

    Heat shock response (HSR) is a universal mechanism in all organisms. It is under tight regulation by heat shock factors (HSFs) and heat shock proteins (HSPs) after heat shock (HS) to prevent stress damage. On the attenuation of HSR, HSP70 and HSF Binding Protein1 (HSBP1) interact with HSF1 and thus dissociate trimeric HSF1 into an inert monomeric form in humans. However, little is known about the effect of HSBP with thermal stress in plants. This report describes our investigation of the role of AtHSBP in Arabidopsis (Arabidopsis thaliana) by genetic and molecular approaches. AtHSBP was heat inducible and ubiquitously expressed in all tissues; AtHSBP was also crucial for seed development, as demonstrated by AtHSBP-knockout lines showing seed abortion. Thermotolerance results showed that AtHSBP participates in acquired thermotolerance but not basal thermotolerance and is a negative regulator of HSR. Subcellular localization revealed that the cytosol-localized AtHSBP translocated to the nucleus in response to HS. Protoplast two-hybrid assay results confirmed that AtHSBP interacts with itself and with the HSFs, AtHSFA1a, AtHSFA1b, and AtHSFA2. AtHSBP also negatively affected AtHSFA1b DNA-binding capacity in vitro. Quantitative polymerase chain reaction and western-blot analysis demonstrated that altered levels of AtHSBP lead to differential HSP expression, mainly during the recovery from HS. These studies provide a new insight into HSBP in plants and reveal that AtHSBP is a negative regulator of HSR and required for seed development.

  5. Heat transfer model for quenching by submerging

    Energy Technology Data Exchange (ETDEWEB)

    Passarella, D N; Varas, F [Departamento de Matematica Aplicada II, E.T.S. de Ing. de Telecomunicacion, Universidad de Vigo, Campus Marcosende, 36310 Vigo (Spain); MartIn, E B, E-mail: diego@dma.uvigo.es, E-mail: fvaras@uvigo.es, E-mail: emortega@uvigo.es [Area de Mecanica de Fluidos, E.T.S. de Ing. Industriales, Universidad de Vigo, Campus Marcosende, 36310 Vigo (Spain)

    2011-05-01

    In quenching by submerging the workpiece is cooled due to vaporization, convective flow and interaction of both mechanisms. The dynamics of these phenomena is very complex and the corresponding heat fluxes are strongly dependent on local flow variables such as velocity of fluid and vapor fraction. This local dependence may produce very different cooling rates along the piece, responsible for inappropriate metallurgical transformations, variability of material properties and residual stresses. In order to obtain an accurate description of cooling during quenching, a mathematical model of heat transfer is presented here. The model is based on the drift-flux mixture-model for multiphase flows, including an equation of conservation of energy for the liquid phase and specific boundary conditions that account for evaporation and presence of vapor phase on the surface of the piece. The model was implemented on Comsol Multiphysics software. Generation of appropriate initial and boundary conditions, as well as numerical resolution details, is briefly discussed. To test the model, a simple flow condition was analyzed. The effect of vapor fraction on heat transfer is assessed. The presence of the typical vapor blanket and its collapse can be recovered by the model, and its effect on the cooling rates on different parts of the piece is analyzed. Comparisons between numerical results and data from literature are made.

  6. Dynamic Shock Response of an S2 Glass/SC15 Epoxy Woven Fabric Composite Material System

    Science.gov (United States)

    Key, Christopher; Alexander, Scott; Harstad, Eric; Schumacher, Shane

    2017-06-01

    The use of S2 glass/SC15 epoxy woven fabric composite materials for blast and ballistic protection has been an area of on-going research over the past decade. In order to accurately model this material system within potential applications under extreme loading conditions, a well characterized and well understood anisotropic equation of state (EOS) is needed. This work details both an experimental program and associated analytical modelling efforts which aim to provide better physical understanding of the anisotropic EOS behavior of this material. Experimental testing focused on planar shock impact tests loading the composite to peak pressures of 15 GPa in both the through-thickness and on-fiber orientation. Test results highlighted the anisotropic response of the material and provided a basis by which the associated numeric micromechanical investigation was compared. Results of the combined experimental and numerical modelling investigation provided insights into not only the constituent material influence on the composite response but also the importance of the geometrical configuration of the plain weave microstructure and the stochastic significance of the microstructural configuration. Sandia National Laboratories is a multi-mission laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. Suppressive and Facilitative Effects of Shock Intensity and Interresponse Times Followed by Shock

    Science.gov (United States)

    Everly, Jessica B.; Perone, Michael

    2012-01-01

    Although response-dependent shock often suppresses responding, response facilitation can occur. In two experiments, we examined the suppressive and facilitative effects of shock by manipulating shock intensity and the interresponse times that produced shock. Rats' lever presses were reinforced on a variable-interval 40-s schedule of food…

  8. Coping with shocks in rural Ethiopia

    NARCIS (Netherlands)

    Debebe, Z.Y.; Mebratie, A.; Sparrow, R.; Abebaw, D.; Dekker, M.; Alemu, G.; Bedi, A.S.

    2013-01-01

    Based on household survey data and event history interviews undertaken in a highly shock prone country, this paper investigates which shocks trigger which coping responses and why? We find clear differences in terms of coping strategies across shock types. The two relatively covariate shocks, that

  9. The Inflammatory Response in Cardiac Surgery. An Up-to-date Overview with the Emphasis on the Role of Heat Shock Proteins (HSPs 60 and 70

    Directory of Open Access Journals (Sweden)

    Pavel Kuneš

    2007-01-01

    Full Text Available Cardiac surgical operations are associated with the development of a systemic inflammatory response syndrome (SIRS. In most cases, the inflammatory response is apparent only in its subclinical form. In some cases, however, it can become clinically manifest or even life-threatening. This review article presents some new data regarding its biological importance, along with an insight into the recently discovered role played by heat shock proteins 60 and 70.

  10. DIFFERENTIAL RESPONSE OF HEAT SHOCK PROTEINS TO UPHILL AND DOWNHILL EXERCISE IN HEART, SKELETAL MUSCLE, LUNG AND KIDNEY TISSUES

    Directory of Open Access Journals (Sweden)

    Pablo C. B. Lollo

    2013-09-01

    Full Text Available Running on a horizontal plane is known to increase the concentration of the stress biomarker heat-shock protein (HSP, but no comparison of the expression of HSP70 has yet been established between the uphill (predominantly concentric and downhill (predominantly eccentric muscle contractions exercise. The objective of the study was to investigate the relationships between eccentric and concentric contractions on the HSP70 response of the lung, kidney, gastrocnemius, soleus and heart. Twenty-four male Wistar weanling rats were divided into four groups: non-exercised and three different grades of treadmill exercise groups: horizontal, uphill (+7% and downhill (-7% of inclination. At the optimal time-point of six hours after the exercise, serum uric acid, creatine kinase (CK and lactate dehydrogenase (LDH were determined by standard methods and HSP70 by the Western blot analysis. HSP70 responds differently to different types of running. For kidney, heart, soleus and gastrocnemius, the HSP70 expression increased, 230, 180, 150 and 120% respectively of the reference (horizontal. When the contraction was concentric (uphill and compared to downhill the increase in response of HSP70 was greater in 80% for kidney, 75% for gastrocnemius, 60% for soleus and 280% for the heart. Uric acid was about 50% higher (0.64 ± 0.03 mg·dL-1 in the uphill group as compared to the horizontal or downhill groups. Similarly, the activities of serum CK and LDH were both 100% greater for both the uphill and downhill groups as compared to the horizontal group (2383 ± 253 and 647.00 ± 73 U/L, respectively. The responsiveness of HSP70 appeared to be quite different depending on the type of tissue, suggesting that the impact of exercise was not restricted to the muscles, but extended to the kidney tissue. The uphill exercise increases HSP70 beyond the eccentric type and the horizontal running was a lower HSP70 responsive stimulus

  11. Heat-shock responsive genes identified and validated in Atlantic cod (Gadus morhua) liver, head kidney and skeletal muscle using genomic techniques.

    Science.gov (United States)

    Hori, Tiago S; Gamperl, A Kurt; Afonso, Luis Ob; Johnson, Stewart C; Hubert, Sophie; Kimball, Jennifer; Bowman, Sharen; Rise, Matthew L

    2010-01-28

    Daily and seasonal changes in temperature are challenges that fish within aquaculture settings cannot completely avoid, and are known to elicit complex organismal and cellular stress responses. We conducted a large-scale gene discovery and transcript expression study in order to better understand the genes that are potentially involved in the physiological and cellular aspects of stress caused by heat-shock. We used suppression subtractive hybridization (SSH) cDNA library construction and characterization to identify transcripts that were dysregulated by heat-shock in liver, skeletal muscle and head kidney of Atlantic cod. These tissues were selected due to their roles in metabolic regulation, locomotion and growth, and immune function, respectively. Fish were exposed for 3 hours to an 8 degrees C elevation in temperature, and then allowed to recover for 24 hours at the original temperature (i.e. 10 degrees C). Tissue samples obtained before heat-shock (BHS), at the cessation of heat-shock (CS), and 3, 12, and 24 hours after the cessation of heat-shock (ACS), were used for reciprocal SSH library construction and quantitative reverse transcription - polymerase chain reaction (QPCR) analysis of gene expression using samples from a group that was transferred but not heat-shocked (CT) as controls. We sequenced and characterized 4394 ESTs (1524 from liver, 1451 from head kidney and 1419 from skeletal muscle) from three "forward subtracted" libraries (enriched for genes up-regulated by heat-shock) and 1586 from the liver "reverse subtracted" library (enriched for genes down-regulated by heat-shock), for a total of 5980 ESTs. Several cDNAs encoding putative chaperones belonging to the heat-shock protein (HSP) family were found in these libraries, and "protein folding" was among the gene ontology (GO) terms with the highest proportion in the libraries. QPCR analysis of HSP90alpha and HSP70-1 (synonym: HSPA1A) mRNA expression showed significant up-regulation in all three

  12. Heat-shock responsive genes identified and validated in Atlantic cod (Gadus morhua liver, head kidney and skeletal muscle using genomic techniques

    Directory of Open Access Journals (Sweden)

    Kimball Jennifer

    2010-01-01

    Full Text Available Abstract Background Daily and seasonal changes in temperature are challenges that fish within aquaculture settings cannot completely avoid, and are known to elicit complex organismal and cellular stress responses. We conducted a large-scale gene discovery and transcript expression study in order to better understand the genes that are potentially involved in the physiological and cellular aspects of stress caused by heat-shock. We used suppression subtractive hybridization (SSH cDNA library construction and characterization to identify transcripts that were dysregulated by heat-shock in liver, skeletal muscle and head kidney of Atlantic cod. These tissues were selected due to their roles in metabolic regulation, locomotion and growth, and immune function, respectively. Fish were exposed for 3 hours to an 8°C elevation in temperature, and then allowed to recover for 24 hours at the original temperature (i.e. 10°C. Tissue samples obtained before heat-shock (BHS, at the cessation of heat-shock (CS, and 3, 12, and 24 hours after the cessation of heat-shock (ACS, were used for reciprocal SSH library construction and quantitative reverse transcription - polymerase chain reaction (QPCR analysis of gene expression using samples from a group that was transferred but not heat-shocked (CT as controls. Results We sequenced and characterized 4394 ESTs (1524 from liver, 1451 from head kidney and 1419 from skeletal muscle from three "forward subtracted" libraries (enriched for genes up-regulated by heat-shock and 1586 from the liver "reverse subtracted" library (enriched for genes down-regulated by heat-shock, for a total of 5980 ESTs. Several cDNAs encoding putative chaperones belonging to the heat-shock protein (HSP family were found in these libraries, and "protein folding" was among the gene ontology (GO terms with the highest proportion in the libraries. QPCR analysis of HSP90α and HSP70-1 (synonym: HSPA1A mRNA expression showed significant up

  13. Impeller Submergence Depth for Stirred Tanks

    Directory of Open Access Journals (Sweden)

    Thiyam T. Devi

    2011-11-01

    Full Text Available Impeller submergence governs the performance of mixing tanks employed in oxygen transfer operation. Present work experimentally investigates the effect of impeller submergence depths on oxygen transfer and corresponding power consumption. It has been found that at higher range of impeller submergence, mixing tanks consume less power and gives higher values of oxygen transfer coefficient. Optimal range of submergence depth is 0.7 to 0.9 times the impeller diameter. Copyright ©2011 BCREC UNDIP. All rights reserved.(Received: 4th March 2011; Revised: 12nd July 2011; Accepted: 14th July 2011[How to Cite: T.T. Devi, A.P. Sinha, M. Thakre, and B. Kumar. (2011. Impeller Submergence Depth for Stirred Tanks. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (2: 123-128. doi:10.9767/bcrec.6.2.826.123-128][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.826.123-128 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/826] | View in 

  14. Effects of Long-Term Periodic Submergence on Photosynthesis and Growth of Taxodium distichum and Taxodium ascendens Saplings in the Hydro-Fluctuation Zone of the Three Gorges Reservoir of China.

    Science.gov (United States)

    Wang, Chaoying; Li, Changxiao; Wei, Hong; Xie, Yingzan; Han, Wenjiao

    2016-01-01

    Responses of bald cypress (Taxodium distichum) and pond cypress (Taxodium ascendens) saplings in photosynthesis and growth to long-term periodic submergence in situ in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR) were studied. Water treatments of periodic deep submergence (DS) and moderate submergence (MS) in situ were imposed on 2-year-old bald cypress and pond cypress saplings. The effects of periodic submergence on photosynthesis and growth were investigated after 3 years (i.e. 3 cycles) compared to a control (i.e. shallow submergence, abbreviated as SS). Results showed that pond cypress had no significant change in net photosynthetic rate (Pn) in response to periodic moderate and deep submergence in contrast to a significant decrease in Pn of bald cypress under both submergence treatments, when compared to that of SS. Ratios of Chlorophyll a/b and Chlorophylls/Carotenoid of pond cypress were significantly increased in periodic moderate submergence and deep submergence, while bald cypress showed no significant change. Diameter at breast height (DBH) and tree height of both species were significantly reduced along with submergence depth. Relative diameter and height growth rates of the two species were also reduced under deeper submergence. Moreover, bald cypress displayed higher relative diameter growth rate than pond cypress under deep submergence mainly attributed to higher productivity of the larger crown area of bald cypress. When subjected to deep subergence, both species showed significant reduction in primary branch number, while in moderate submergence, bald cypress but not pond cypress showed significant reduction in primary branch number. These results indicate that both bald cypress and pond cypress are suitbale candidates for reforestation in the TGDR region thanks to their submergence tolerance characteristics, but bald cypress can grow better than pond cypress under deep submergence overall.

  15. Effects of Long-Term Periodic Submergence on Photosynthesis and Growth of Taxodium distichum and Taxodium ascendens Saplings in the Hydro-Fluctuation Zone of the Three Gorges Reservoir of China.

    Directory of Open Access Journals (Sweden)

    Chaoying Wang

    Full Text Available Responses of bald cypress (Taxodium distichum and pond cypress (Taxodium ascendens saplings in photosynthesis and growth to long-term periodic submergence in situ in the hydro-fluctuation zone of the Three Gorges Dam Reservoir (TGDR were studied. Water treatments of periodic deep submergence (DS and moderate submergence (MS in situ were imposed on 2-year-old bald cypress and pond cypress saplings. The effects of periodic submergence on photosynthesis and growth were investigated after 3 years (i.e. 3 cycles compared to a control (i.e. shallow submergence, abbreviated as SS. Results showed that pond cypress had no significant change in net photosynthetic rate (Pn in response to periodic moderate and deep submergence in contrast to a significant decrease in Pn of bald cypress under both submergence treatments, when compared to that of SS. Ratios of Chlorophyll a/b and Chlorophylls/Carotenoid of pond cypress were significantly increased in periodic moderate submergence and deep submergence, while bald cypress showed no significant change. Diameter at breast height (DBH and tree height of both species were significantly reduced along with submergence depth. Relative diameter and height growth rates of the two species were also reduced under deeper submergence. Moreover, bald cypress displayed higher relative diameter growth rate than pond cypress under deep submergence mainly attributed to higher productivity of the larger crown area of bald cypress. When subjected to deep subergence, both species showed significant reduction in primary branch number, while in moderate submergence, bald cypress but not pond cypress showed significant reduction in primary branch number. These results indicate that both bald cypress and pond cypress are suitbale candidates for reforestation in the TGDR region thanks to their submergence tolerance characteristics, but bald cypress can grow better than pond cypress under deep submergence overall.

  16. Sirtuin 1 Agonist Minimizes Injury and Improves the Immune Response Following Traumatic Shock.

    Science.gov (United States)

    Luciano, Jason A; Kautza, Benjamin; Darwiche, Sophie; Martinez, Silvia; Stratimirovic, Sladjana; Waltz, Paul; Sperry, Jason; Rosengart, Matthew; Shiva, Sruti; Zuckerbraun, Brian S

    2015-08-01

    Survival from traumatic injury requires a coordinated and controlled inflammatory and immune response. Mitochondrial and metabolic responses to stress have been shown to play a role in these inflammatory and immune responses. We hypothesized that increases in mitochondrial biogenesis via a sirtuin 1 agonist would decrease tissue injury and partially ameliorate the immunosuppression seen following trauma. C57Bl/6 mice were subjected to a multiple trauma model. Mice were pretreated with either 100 mg/kg per day of the sirtuin 1 agonist, Srt1720, via oral gavage for 2 days prior to trauma and extended until the day the animals were killed, or they were pretreated with peroxisome proliferator-activated receptor γ coactivator 1α (PGC1α) siRNA via hydrodynamic tail vein injection 48 h prior to trauma. Markers for mitochondrial function and biogenesis were measured in addition to splenocyte proliferative capacity and bacterial clearance. Srt1720 was noted to improve mitochondrial biogenesis, mitochondrial function, and complex IV activity following traumatic injury (P changes in mitochondrial function were associated with altered severity of hepatic injury with significant reductions in serum alanine aminotransferase levels seen in mice treated with srt1720. Splenocyte proliferative capacity and intraperitoneal bacterial clearance were evaluated as markers for overall immune function following trauma-hemorrhage. Treatment with Srt1720 minimized the trauma-induced decreases in splenocyte proliferation (P < 0.05), whereas treatment with PGC1α siRNA led to diminished bacterial clearance. The PGC1α signaling pathway is an important regulator of mitochondrial function and biogenesis, which can potentially be harnessed to protect against hepatic injury and minimize the immunosuppression that is seen following trauma-hemorrhage.

  17. A dislocation density-based continuum model of the anisotropic shock response of single crystal α-cyclotrimethylene trinitramine

    Science.gov (United States)

    Luscher, D. J.; Addessio, F. L.; Cawkwell, M. J.; Ramos, K. J.

    2017-01-01

    We have developed a model for the finite deformation thermomechanical response of α-cyclotrimethylene trinitramine (RDX). Our model accounts for nonlinear thermoelastic lattice deformation through a free energy-based equation of state developed by Cawkwell et al. (2016) in combination with temperature and pressure dependent elastic constants, as well as dislocation-mediated plastic slip on a set of slip systems motivated by experimental observation. The kinetics of crystal plasticity are modeled using the Orowan equation relating slip rate to dislocation density and the dislocation velocity developed by Austin and McDowell (2011), which naturally accounts for transition from thermally activated to dislocation drag limited regimes. Evolution of dislocation density is specified in terms of local ordinary differential equations reflecting dislocation-dislocation interactions. This paper presents details of the theory and parameterization of the model, followed by discussion of simulations of flyer plate impact experiments. Impact conditions explored within this combined simulation and experimental effort span shock pressures ranging from 1 to 3 GPa for four crystallographic orientations and multiple specimen thicknesses. Simulation results generated using this model are shown to be in strong agreement with velocimetry measurements from the corresponding plate impact experiments. Finally, simulation results are used to motivate conclusions about the nature of dislocation-mediated plasticity in RDX.

  18. From protein-protein interaction to therapy response: Molecular imaging of heat shock proteins

    Energy Technology Data Exchange (ETDEWEB)

    Niu Gang [Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford University School of Medicine, 1201 Welch Rd, P095, Stanford, CA 94305-5484 (United States); Chen Xiaoyuan [Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford University School of Medicine, 1201 Welch Rd, P095, Stanford, CA 94305-5484 (United States)], E-mail: shawchen@stanford.edu

    2009-05-15

    HSP70 promoter-driven gene therapy and inhibition of HSP90 activity with small molecule inhibitors are two shining points in a newly developed cohort of cancer treatment. For HSP70 promoters, high efficiency and heat inducibility within a localized region make it very attractive to clinical translation. The HSP90 inhibitors exhibit a broad spectrum of anticancer activities due to the downstream effects of HSP90 inhibition, which interfere with a wide range of signaling processes that are crucial for the malignant properties of cancer cells. In this review article, we summarize exciting applications of newly emerged molecular imaging techniques as they relate to HSP, including protein-protein interactions of HSP90 complexes, therapeutic response of tumors to HSP90 inhibitors, and HSP70 promoters-controlled gene therapy. In the HSPs context, molecular imaging is expected to play a vital role in promoting drug development and advancing individualized medicine.

  19. Development of Drop/Shock Test in Microelectronics and Impact Dynamic Analysis for Uniform Board Response

    Science.gov (United States)

    Kallolimath, Sharan Chandrashekar

    For the past several years, many researchers are constantly developing and improving board level drop test procedures and specifications to quantify the solder joint reliability performance of consumer electronics products. Predictive finite element analysis (FEA) by utilizing simulation software has become widely acceptable verification method which can reduce time and cost of the real-time test process. However, due to testing and metrological limitations it is difficult not only to simulate exact drop condition and capture critical measurement data but also tedious to calibrate the system to improve test methods. Moreover, some of the important ever changing factors such as board flexural rigidity, damping, drop height, and drop orientation results in non-uniform stress/strain distribution throughout the test board. In addition, one of the most challenging tasks is to quantify uniform stress and strain distribution throughout the test board and identify critical failure factors. The major contributions of this work are in the four aspects of the drop test in electronics as following. First of all, an analytical FEA model was developed to study the board natural frequencies and responses of the system with the consideration of dynamic stiffness, damping behavior of the material and effect of impact loading condition. An approach to find the key parameters that affect stress and strain distributions under predominate mode responses was proposed and verified with theoretical solutions. Input-G method was adopted to study board response behavior and cut boundary interpolation methods was used to analyze local model solder joint stresses with the development of global/local FEA model in ANSYS software. Second, no ring phenomenon during the drop test was identified theoretically when the test board was modeled as both discrete system and continuous system. Numerical analysis was then conducted by FEA method for detailed geometry of attached chips with solder

  20. Pre-exercise alkalosis attenuates the heat shock protein 72 response to a single-bout of anaerobic exercise.

    Science.gov (United States)

    Peart, Daniel J; McNaughton, Lars R; Midgley, Adrian W; Taylor, Lee; Towlson, Christopher; Madden, Leigh A; Vince, Rebecca V

    2011-09-01

    The heat shock protein 72 (HSP72) response following exercise is well documented, however, little is known on whether the expression may be mediated by the ingestion of ergogenic aids prior to performance. The purpose of this research was to investigate the effect of sodium bicarbonate (NaHCO(3)) ingestion on monocyte and lymphocyte expressed HSP72 and oxidative stress for 4-h post exercise. Seven active males (22.3 ± 2.9 years, 181.6 ± 4.5 cm, 78.1 ± 8.1 kg) performed a 4-min 'all-out' cycle test following a dose of 0.3 g kg(-1) body mass of NaHCO(3), or an equimolar placebo dose of sodium chloride. HSP72 was measured by flow cytometry and oxidative stress was determined via plasma thiobarbituric acid substances (TBARS) analysis. The NaHCO(3) ingestion significantly increased blood pH (pexercise. Despite this there was no evidence of a significantly improved exercise performance when compared with the placebo trials (p ≥ 0.26) (means ± SD; average power 292 ± 43 W vs. 291 ± 50 W; peak power 770 ± 218 W vs. 775 ± 211 W; work completed 71 ± 10 kJ vs. 68 ± 10 kJ). Monocyte expressed HSP72 was significantly lower under experimental conditions during the 4-h post-exercise (p=0.013), as was plasma TBARS (pexercise alkalosis can attenuate the stress response to a single bout of anaerobic exercise. Copyright © 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  1. Myocardial and haemodynamic responses to two fluid regimens in African children with severe malnutrition and hypovolaemic shock (AFRIM study)

    NARCIS (Netherlands)

    Obonyo, Nchafatso; Brent, Bernadette; Olupot-Olupot, Peter; Boele van Hensbroek, Michael; Kuipers, Irene; Wong, Sidney; Shiino, Kenji; Chan, Jonathan; Fraser, John; van Woensel, Job B. M.; Maitland, Kathryn

    2017-01-01

    Background: Fluid therapy in severely malnourished children is hypothesized to be deleterious owing to compromised cardiac function. We evaluated World Health Organization (WHO) fluid resuscitation guidelines for hypovolaemic shock using myocardial and haemodynamic function and safety endpoints.

  2. Technological response to economic disruption: The role of new technologies in mitigating exogenous economic shocks

    Science.gov (United States)

    Spencer, Aron Scott

    2003-07-01

    The three essays in this dissertation deal with the role of technology in mitigating economic disruption. Much research has been done on the disruptive effects of technology; in contrast, these essays look at how technology can be used to reduce the effects of exogenous disruptions. Each essay looks at the issue at a different level; the first at the firm level, the second at the industry level and the final essay at the level of the national economy. The first essay examines the options and possible strategies for firms faced with increased instability in their electricity supply, as recently occurred in California. This paper develops response strategies for companies affected by an electrical crisis. These responses fall into three categories: Lead, Follow, or Get Out of the State. The technologies available to companies choosing to lead are reviewed, along with constraints to their adoption. From these strategies, it can be shown that areas with unstable electrical markets can expect a loss of firms to locales with less risk and uncertainty, unless governments adopt policies promoting distributed generation. The second essay projects the economic impacts of the adoption of high-temperature superconductor (FITS) technologies in electric generation, transmission, and distribution systems. Three technologies utilizing high-temperature superconductors are analyzed for their potential impact on the electrical utility industry. Distributed superconducting magnetic energy storage systems (D-SMES), superconducting cable, and HTS generators are each described along with their possible uses in the electrical utility industry. The economic impact of these technologies is then projected, along with a comparison between them and conventional technologies. The third essay deals with the role of technology in mitigating the economic effects of the reaction to terrorist attacks. In the wake of the terrorist attacks of September 11, 2001, public and private investments are

  3. Laser Beam Submerged Arc Hybrid Welding

    Science.gov (United States)

    Reisgen, Uwe; Olschok, Simon; Jakobs, Stefan; Schleser, Markus; Mokrov, Oleg; Rossiter, Eduardo

    The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The high deposition rate of the SA process in combination with the laser beam process offers, providing the appropriate choice of weld preparation, the possibility of welding plates with a thickness larger than 20° mm in a single pass, and also of welding thicker plates with the double-sided single pass technique.

  4. The 26 December 2001 Solar Eruptive Event Responsible for GLE63: III. CME, Shock Waves, and Energetic Particles

    Science.gov (United States)

    Grechnev, V. V.; Kiselev, V. I.; Uralov, A. M.; Klein, K.-L.; Kochanov, A. A.

    2017-08-01

    The SOL2001-12-26 moderate solar eruptive event (GOES importance M7.1, microwaves up to 4000 sfu at 9.4 GHz, coronal mass ejection (CME) speed 1446 km s-1) produced strong fluxes of solar energetic particles and ground-level enhancement (GLE) of cosmic-ray intensity (GLE63). To find a possible reason for the atypically high proton outcome of this event, we study multi-wavelength images and dynamic radio spectra and quantitatively reconcile the findings with each other. An additional eruption probably occurred in the same active region about half an hour before the main eruption. The latter produced two blast-wave-like shocks during the impulsive phase. The two shock waves eventually merged around the radial direction into a single shock traced up to 25 R_{⊙} as a halo ahead of the expanding CME body, in agreement with an interplanetary Type II event recorded by the Radio and Plasma Wave Investigation (WAVES) experiment on the Wind spacecraft. The shape and kinematics of the halo indicate an intermediate regime of the shock between the blast wave and bow shock at these distances. The results show that i) the shock wave appeared during the flare rise and could accelerate particles earlier than usually assumed; ii) the particle event could be amplified by the preceding eruption, which stretched closed structures above the developing CME, facilitated its lift-off and escape of flare-accelerated particles, enabled a higher CME speed and stronger shock ahead; iii) escape of flare-accelerated particles could be additionally facilitated by reconnection of the flux rope, where they were trapped, with a large coronal hole; and iv) the first eruption supplied a rich seed population accelerated by a trailing shock wave.

  5. Multielement stoichiometry of submerged macrophytes across Yunnan plateau lakes (China)

    National Research Council Canada - National Science Library

    Xing, Wei; Wu, Haoping; Shi, Qiao; Hao, Beibei; Liu, Han; Wang, Zhixiu; Liu, Guihua

    2015-01-01

    .... We predicted that tissue element composition in submerged macrophytes is affected by lake trophic level and taxonomy, and submerged macrophytes have weak stoichiometric homeostasis for all above 16 elements...

  6. Study of the response of Zircaloy- 4 cladding to thermal shock during water quenching after double sided steam oxidation at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Sawarn, Tapan K., E-mail: sawarn@barc.gov.in; Banerjee, Suparna; Kumar, Sunil

    2016-05-15

    This study investigates the failure of embrittled Zircaloy-4 cladding in a simulated loss of coolant accident condition and correlates it with the evolved stratified microstructure. Isothermal steam oxidation of Zircaloy-4 cladding at high temperatures (900–1200 °C) with soaking periods in the range 60–900 s followed by water quenching was carried out. The combined oxide + oxygen stabilized α-Zr layer thickness and the fraction of the load bearing phase (recrystallised α-Zr grains + prior β-Zr or only prior β-Zr) of clad tube specimens were correlated with the %ECR calculated using Baker-Just equation. Average oxygen concentration of the load bearing phase corresponding to different oxidation conditions was calculated from the average microhardness using an empirical correlation. The results of these experiments are presented in this paper. Thermal shock sustainability of the clad was correlated with the %ECR, combined oxide+α-Zr(O) layer thickness, fraction of the load bearing phase and its average oxygen concentration. - Highlights: • Response of the embrittled Zircaloy-4 clad towards thermal shock, simulated under LOCA condition was investigated. • Thermal shock sustainability of the clad was correlated with its evolved stratified microstructure. • Cladding fails at %ECR value ≥ 29. • To resist the thermal shock, clad should have load bearing phase fraction > 0.44 and average oxygen concentration < 0.69 wt%.

  7. Detection of the Host Immune Response to Burkholderia mallei Heat-Shock Proteins GroEL and DnaK in a Glanders Patient and Infected Mice

    Science.gov (United States)

    2007-01-01

    host cell. A GroEL-like protein in Actinobacillus actinomycetemcomitans, a patho- gen associated with periodontal disease , was found in extracellular...shock proteins in protection from and pathogenesis of infectious diseases . Clin Microbiol Rev 12:19–39. Zugel U, Schoel B, Yamamoto S, Hengel H...us Disease 59 (2007) 137–147 www.elsevier.com/locate/diagmicrobioDiagnostic Microbiology and InfectioDetection of the host immune response to

  8. Oxygen dynamics in submerged rice (Oryza sativa L.)

    DEFF Research Database (Denmark)

    Colmer, Timothy D.; Pedersen, Ole

    2008-01-01

    Complete submergence of plants prevents direct O2 and CO2 exchange with air. Underwater photosynthesis can result in marked diurnal changes in O2 supply to submerged plants. Dynamics in pO2 had not been measured directly for submerged rice (Oryza sativa), but in an earlier study, radial O2 loss...

  9. Responses of heat shock protein 70 and caspase-3/7 to dietary selenomethionine in juvenile white sturgeon

    Directory of Open Access Journals (Sweden)

    Weifang Wang

    2016-03-01

    Full Text Available An 8-week feeding trial was conducted to investigate the responses of juvenile white sturgeon (Acipenser transmontanus to elevated dietary selenium (Se based on the determination of the RNA/DNA ratio in muscle, heat shock protein 70 (Hsp70, and caspase-3/7 in muscle and/or liver tissues. Four semi-purified test diets were prepared by adding different levels of L-selenomethionine (0, 50, 100, and 200 mg/kg diet. The analytical determinations of total Se were 2.2, 19.7, 40.1, and 77.7 mg/kg diet. The sturgeon (initial body weight: 30 ± 2 g; mean ± SEM were raised in indoor tanks provided with flow through freshwater (18–19 °C. There were three replicates for each dietary treatment with 25 fish per replicate. The liver and muscle tissues were collected at 4 and 8 weeks after feeding the test diets. A significant interaction between duration and levels of dietary Se exposures on RNA/DNA ratio in the muscle tissue was detected (P < 0.05. Although there was no significant main effect due to the duration of dietary Se exposures (i.e., 4 weeks versus 8 weeks on muscle RNA/DNA ratio (P ≥ 0.05, the ratio was significantly decreased with increasing dietary Se levels. Significant main effects were caused by the duration and levels of dietary Se exposures on Hsp70 in both the muscle and liver tissues, with significant increases in Hsp70 due to a longer exposure (8 weeks and higher levels (40.1 and 77.7 mg Se/kg diet of dietary Se. The caspase-3/7 activity in the liver were significantly higher in fish fed the diets containing 40.1 and 77.7 mg Se/kg diet than those fed the other diets. The toxic thresholds of Se in the muscle were estimated to be 32.2 and 26.6 mg Se/kg for the depressed specific growth rate and the induced Hsp70 response in muscle, respectively. This result indicated that the Hsp70 response in muscle is a more sensitive biomarker than the SGR of sturgeon for evaluating Se toxicity in white sturgeon. Results of the

  10. Silver nanoparticles and dissolved silver activate contrasting immune responses and stress-induced heat shock protein expression in sea urchin.

    Science.gov (United States)

    Magesky, Adriano; de Oliveira Ribeiro, Ciro A; Beaulieu, Lucie; Pelletier, Émilien

    2017-07-01

    Using immune cells of sea urchin Strongylocentrotus droebachiensis in early development as a model, the cellular protective mechanisms against ionic and poly(allylamine)-coated silver nanoparticle (AgNPs; 14 ± 6 nm) treatments at 100 μg L -1 were investigated. Oxidative stress, heat shock protein expression, and pigment production by spherulocytes were determined as well as AgNP translocation pathways and their multiple effects on circulating coelomocytes. Sea urchins showed an increasing resilience to Ag over time because ionic Ag is accumulated in a steady way, although nanoAg levels dropped between 48 h and 96 h. A clotting reaction emerged on tissues injured by dissolved Ag (present as chloro-complexes in seawater) between 12 h and 48 h. Silver contamination and nutritional state influenced the production of reactive oxygen species. After passing through coelomic sinuses and gut, AgNPs were found in coelomocytes. Inside blood vessels, apoptosis-like processes appeared in coelomocytes highly contaminated by poly(allylamine)-coated AgNPs. Increasing levels of Ag accumulated by urchins once exposed to AgNPs pointed to a Trojan-horse mechanism operating over 12-d exposure. However, under short-term treatments, physical interactions of poly(allylamine)-coated AgNPs with cell structures might be, at some point, predominant and responsible for the highest levels of stress-related proteins detected. The present study is the first report detailing nano-translocation in a marine organism and multiple mechanisms by which sea urchin cells can deal with toxic AgNPs. Environ Toxicol Chem 2017;36:1872-1886. © 2016 SETAC. © 2016 SETAC.

  11. Benthic bacterial diversity in submerged sinkhole ecosystems.

    Science.gov (United States)

    Nold, Stephen C; Pangborn, Joseph B; Zajack, Heidi A; Kendall, Scott T; Rediske, Richard R; Biddanda, Bopaiah A

    2010-01-01

    Physicochemical characterization, automated ribosomal intergenic spacer analysis (ARISA) community profiling, and 16S rRNA gene sequencing approaches were used to study bacterial communities inhabiting submerged Lake Huron sinkholes inundated with hypoxic, sulfate-rich groundwater. Photosynthetic cyanobacterial mats on the sediment surface were dominated by Phormidium autumnale, while deeper, organically rich sediments contained diverse and active bacterial communities.

  12. Production of extracellular aspartic protease in submerged ...

    African Journals Online (AJOL)

    Yomi

    29(1): 1-6. Fraile ER, Bernardinelli SE, Handel M, Jauregui AM (1978). Selección de cepas de Mucor sp productoras de enzimas coagulantes de leche. Rev. Arg. Microbiol. 10(2): 65-69. Ghareib M, Hamdy HS, Khalil AA (2001). Production of intracellular milk clotting enzyme in submerged cultures of Fusarium subglutinans.

  13. Topology optimization for submerged buoyant structures

    NARCIS (Netherlands)

    Picelli, R.; van Dijk, R.; Vicente, W.M.; Pavanello, R.; Langelaar, M.; van Keulen, A.

    2017-01-01

    This paper presents an evolutionary structural topology optimization method for the design of completely submerged buoyant modules with design-dependent fluid pressure loading. This type of structure is used to support offshore rig installation and pipeline transportation at all water depths. The

  14. Production of extracellular aspartic protease in submerged ...

    African Journals Online (AJOL)

    Fungal milk-clotting enzymes have gained value as bovine Chymosin substitutes in the cheese industry. In this work, the effects of culture conditions on the production of extracellular milk clotting enzymes from Mucor mucedo DSM 809 in submerged fermentation were studied. The maximum activity was observed after 48 h ...

  15. What Causes Cardiogenic Shock?

    Science.gov (United States)

    ... Home / Shock Cardiogenic Shock Causes Immediate Causes Cardiogenic shock occurs if the ... is cardiogenic shock. Tests and Procedures To Diagnose Shock and Its Underlying Causes Blood Pressure Test Medical ...

  16. What Is Cardiogenic Shock?

    Science.gov (United States)

    ... Home / Shock Cardiogenic Shock Causes Immediate Causes Cardiogenic shock occurs if the ... is cardiogenic shock. Tests and Procedures To Diagnose Shock and Its Underlying Causes Blood Pressure Test Medical ...

  17. Chlamydia trachomatis responds to heat shock, penicillin induced persistence, and IFN-gamma persistence by altering levels of the extracytoplasmic stress response protease HtrA

    Directory of Open Access Journals (Sweden)

    Mathews Sarah A

    2008-11-01

    Full Text Available Abstract Background Chlamydia trachomatis, an obligate intracellular human pathogen, is the most prevalent bacterial sexually transmitted infection worldwide and a leading cause of preventable blindness. HtrA is a virulence and stress response periplasmic serine protease and molecular chaperone found in many bacteria. Recombinant purified C. trachomatis HtrA has been previously shown to have both activities. This investigation examined the physiological role of Chlamydia trachomatis HtrA. Results The Chlamydia trachomatis htrA gene complemented the lethal high temperature phenotype of Escherichia coli htrA- (>42°C. HtrA levels were detected to increase by western blot and immunofluorescence during Chlamydia heat shock experiments. Confocal laser scanning microscopy revealed a likely periplasmic localisation of HtrA. During penicillin induced persistence of Chlamydia trachomatis, HtrA levels (as a ratio of LPS were initially less than control acute cultures (20 h post infection but increased to more than acute cultures at 44 h post infection. This was unlike IFN-γ persistence where lower levels of HtrA were observed, suggesting Chlamydia trachomatis IFN-γ persistence does not involve a broad stress response. Conclusion The heterologous heat shock protection for Escherichia coli, and increased HtrA during cell wall disruption via penicillin and heat shock, indicates an important role for HtrA during high protein stress conditions for Chlamydia trachomatis.

  18. Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

    Directory of Open Access Journals (Sweden)

    N. Simos

    2016-11-01

    Full Text Available A comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace industries due to their unique combination of high temperature stability, low density, and high strength. The performance of carbon-carbon composites and compounds under intense proton beams and long-term irradiation have been studied in a series of experiments and compared with the performance of graphite. The 24-GeV proton beam experiments confirmed the inherent ability of a 3D C/C fiber composite to withstand a thermal shock. A series of irradiation damage campaigns explored the response of different C/C structures as a function of the proton fluence and irradiating environment. Radiolytic oxidation resulting from the interaction of oxygen molecules, the result of beam-induced radiolysis encountered during some of the irradiation campaigns, with carbon atoms during irradiation with the presence of a water coolant emerged as a dominant contributor to the observed structural integrity loss at proton fluences ≥5×10^{20}  p/cm^{2}. The carbon-fiber composites were shown to exhibit significant anisotropy in their dimensional stability driven by the fiber weave and the microstructural behavior of the fiber and carbon matrix accompanied by the presence of manufacturing porosity and defects. Carbon-fiber-reinforced molybdenum-graphite compounds (MoGRCF selected for their impedance properties in the Large Hadron Collider beam collimation exhibited significant decrease in postirradiation load-displacement behavior even after low dose levels (∼5×10^{18}

  19. Response of the polymers KEL-F, polysulfone, high density polyethylene and polymethylmethacrylate to shock loading and release from 0. 3 to 2. 4 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, M.U.

    1991-01-01

    The Bauer PVDF stress-rate gauge has been used to study the response of the cited polymers from measurements at the impact surface and in-situ'' at sample thicknesses of 1.5 and 3 mm. The PVDF stress- rate dependent piezoelectric output combined with appropriate signal recording techniques allow accurate recording over the broad range of stress rates encountered during shock compression of polymers. Strong viscous response effects are observed. The release velocity is found to increase strongly with pressure, and the release-rate history is recorded with PVDF as a continuous function of pressure. 12 refs., 4 figs., 1 tab.

  20. Over-expression of Sub1 A, a submergence tolerance gene from ...

    African Journals Online (AJOL)

    Sub1A, an ethylene-response-factor-like (ERE-like) gene, mediates the extinguished submergence tolerance of rice. To gain further insight into the function of Sub1A in other species, we transformed tobacco plants with the gene under the control of the ubiquitin promoter. Compared to the wild-type plants, transgenic plants ...

  1. Septic Shock

    Science.gov (United States)

    Seymour, Christopher W.; Rosengart, Matthew R.

    2015-01-01

    IMPORTANCE Septic shock is a clinical emergency that occurs in more than 230 000 US patients each year. OBSERVATIONS AND ADVANCES In the setting of suspected or documented infection, septic shock is typically defined in a clinical setting by low systolic (≤90 mm Hg) or mean arterial blood pressure (≤65 mm Hg) accompanied by signs of hypoperfusion (eg, oliguria, hyperlactemia, poor peripheral perfusion, or altered mental status). Focused ultrasonography is recommended for the prompt recognition of complicating physiology (eg, hypovolemia or cardiogenic shock), while invasive hemodynamic monitoring is recommended only for select patients. In septic shock, 3 randomized clinical trials demonstrate that protocolized care offers little advantage compared with management without a protocol. Hydroxyethyl starch is no longer recommended, and debate continues about the role of various crystalloid solutions and albumin. CONCLUSIONS AND RELEVANCE The prompt diagnosis of septic shock begins with obtainment of medical history and performance of a physical examination for signs and symptoms of infection and may require focused ultrasonography to recognize more complex physiologic manifestations of shock. Clinicians should understand the importance of prompt administration of intravenous fluids and vasoactive medications aimed at restoring adequate circulation, and the limitations of protocol-based therapy, as guided by recent evidence. PMID:26284722

  2. Pressure Hull Analysis under Shock Loading

    Directory of Open Access Journals (Sweden)

    Ya-Jung Lee

    2008-01-01

    Full Text Available The hull of high performance submarines must resist underwater shock loading due to exploding torpedoes or depth bombs. An underwater shock involving an initial shock wave and successive bubble pulsating waves is so complex that a theoretical technique for deriving shock pressure distribution is required for improving simulation efficiency. Complete shock loading is obtained theoretically in this work, and responses of a submarine pressure hull are calculated using ABAQUS USA (Underwater Shock Analysis codes. In the long run, this deflection and stress data will assist in examining the structural arrangement of the submarine pressure hull.

  3. THE INFLUENCE OF SUBMERGED MACROPHYTES ON SEDIMENTARY DIATOM ASSEMBLAGES(1).

    Science.gov (United States)

    Vermaire, Jesse C; Prairie, Yves T; Gregory-Eaves, Irene

    2011-12-01

    Submerged macrophytes are a central component of lake ecosystems; however, little is known regarding their long-term response to environmental change. We have examined the potential of diatoms as indicators of past macrophyte biomass. We first sampled periphyton to determine whether habitat was a predictor of diatom assemblage. We then sampled 41 lakes in Quebec, Canada, to evaluate whether whole-lake submerged macrophyte biomass (BiomEpiV) influenced surface sediment diatom assemblages. A multivariate regression tree (MRT) was used to construct a semiquantitative model to reconstruct past macrophyte biomass. We determined that periphytic diatom assemblages on macrophytes were significantly different from those on wood and rocks (ANOSIM R = 0.63, P macrophyte, nutrient-limited lakes (BiomEpiV ≥525 μg · L(-1) ; total phosphorus [TP] macrophyte, nutrient-limited lakes (BiomEpiV eutrophic lakes (TP ≥35 μg · L(-1) ; six lakes). A semiquantitative model correctly predicted the MRT group of the lake 71% of the time (P macrophytes have a significant influence on diatom community structure and that sedimentary diatom assemblages can be used to infer past macrophyte abundance. © 2011 Phycological Society of America.

  4. Pump Coastdown with the Submerged Flywheel

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Hyun-Gi; Seo, KyoungWoo; Kim, Seong Hoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Many research reactors are generally designed as open pool types in consideration of the heat removal of the nuclear fuels, reactor operation and accessibility. Reactor structure assembly is generally placed at the pool bottom as shown in Fig. 1. Primary cooling system pump circulates the coolant from the reactor structure to the heat exchanger in order to continuously remove the heat generated from the reactor core in the research reactor as shown in Fig. 1. The secondary cooling system releases the transferred heat to the atmosphere by the cooling tower. Coastdown flow rate of the primary cooling system pump with the submerged flywheel are calculated analytically in case of the accident situation. Coastdown flow rate is maintained until almost 80 sec when the pump stops normally. But, coastdown flow rate is rapidly decreased when the flywheel is submerged because of the friction load on the flywheel surface.

  5. Factors involved in spatiotemporal dynamics of submerged macrophytes in a Portuguese coastal lagoon under Mediterranean climate

    Science.gov (United States)

    Antunes, Cristina; Correia, Otília; Marques da Silva, Jorge; Cruces, Anabela; Freitas, Maria da Conceição; Branquinho, Cristina

    2012-09-01

    Submerged macrophytes are key in coastal ecosystems, with important structural and functional roles. Thus, the characterization of the submerged aquatic vegetation dynamics is of prime importance for assessing the ecological status of coastal ecosystems. The main aim of this study was to assess the spatial and temporal dynamics of submerged macrophytes biomass in a temporarily open coastal lagoon in Melides, Portugal, and to evaluate the physiological performance of the dominant macrophyte in the system. This lagoon is subject to several disturbances such as the dramatic changes in water physicochemical parameters over time, since temporarily opens to the sea occur renewing the lagoon water content. Moreover it is under a Mediterranean climate with the inherently high temporal variability of precipitation and high temperatures during the summer. Our study shows that the submerged macrophyte community was dominated initially by Ruppia cirrhosa and then replaced by Potamogeton pectinatus, which showed a marked temporal and spatial pattern with extremely high values of biomass in August and in the inner part of the lagoon. The spatial and temporal biomass patterns in submerged macrophytes were mainly related with water level, salinity, pH and transparency. The physiological performance of R. cirrhosa was lower when there was greater biomass accumulation and in extremely shallow waters, whereas physiological vigor seemed to be greater at moderate temperatures and in areas with higher salinity and dissolved oxygen. The data from this study can be used to predict submerged biomass macrophyte responses to extreme water quality changes and to feed a decision support system for the best period to promote the seasonal artificial breaching of the sandy barrier.

  6. Elevation dynamics in a restored versus a submerging salt marsh in Long Island Sound

    Science.gov (United States)

    Anisfeld, Shimon C.; Hill, Troy D.; Cahoon, Donald R.

    2016-01-01

    Accelerated sea-level rise (SLR) poses the threat of salt marsh submergence, especially in marshes that are relatively low-lying. At the same time, restoration efforts are producing new low-lying marshes, many of which are thriving and avoiding submergence. To understand the causes of these different fates, we studied two Long Island Sound marshes: one that is experiencing submergence and mudflat expansion, and one that is undergoing successful restoration. We examined sedimentation using a variety of methods, each of which captures different time periods and different aspects of marsh elevation change: surface-elevation tables, marker horizons, sediment cores, and sediment traps. We also studied marsh hydrology, productivity, respiration, nutrient content, and suspended sediment. We found that, despite the expansion of mudflat in the submerging marsh, the areas that remain vegetated have been gaining elevation at roughly the rate of SLR over the last 10 years. However, this elevation gain was only possible thanks to an increase in belowground volume, which may be a temporary response to waterlogging. In addition, accretion rates in the first half of the twentieth century were much lower than current rates, so century-scale accretion in the submerging marsh was lower than SLR. In contrast, at the restored marsh, accretion rates are now averaging about 10 mm yr−1 (several times the rate of SLR), much higher than before restoration. The main cause of the different trajectories at the two marshes appeared to be the availability of suspended sediment, which was much higher in the restored marsh. We considered and rejected alternative hypotheses, including differences in tidal flooding, plant productivity, and nutrient loading. In the submerging marsh, suspended and deposited sediment had relatively high organic content, which may be a useful indicator of sediment starvation.

  7. Coastline Protection by a Submerged Breakwater

    Science.gov (United States)

    Valentine, B. D.; Hayatdavoodi, M.; Ertekin, R. C.

    2016-02-01

    Coastal communities are in danger of the impact caused by storm surge and waves. Storm surge brings the water level to a higher elevation and farther inland. This rise in water level increases the chance of a higher number and larger set of waves approaching shorelines, and it can potentially devastate the coastal infrastructure. In this study, we evaluate the performance of a submerged, horizontal breakwater located near shore. Unlike other types of breakwaters, such as the ones that extend to the surface, either fixed or floating, a submerged horizontal breakwater does not create any visual distraction or limit most of the recreational and commercial activities in the nearshore areas. The Level I Green-Naghdi (GN) nonlinear water wave equations are utilized here to study the wave transformation over a submerged breakwater that is located in shallow water. The GN theory is based on the theory of directed fluid sheets and assumes an incompressible and inviscid fluid; no assumption on the rotationality of the flow is required. In this approach, the nonlinear boundary conditions and the averaged conservation laws are satisfied exactly. The reflection and transmission coefficients due to nonlinear shallow water waves are determined implementing two approaches which use Goda's (1976) and Grue's (1992) methods. The results are compared with the existing laboratory experiments, and close agreement is observed overall. Preliminary results of the performance of the breakwater on dissipating storm waves during Hurricane Ike (2008), approaching the shore of Galveston, Texas, are presented.

  8. Coping with shocks in rural Ethiopia

    NARCIS (Netherlands)

    Z.Y. Debebe (Zelalem); A.D. Mebratie (Anagaw); R.A. Sparrow (Robert); D. Abebaw Ejigie (Degnet); M. Dekker (Marleen); G. Alemu (Getnet ); A.S. Bedi (Arjun Singh)

    2013-01-01

    textabstractBased on household survey data and event history interviews undertaken in a highly shock prone country, this paper investigates which shocks trigger which coping responses and why? We find clear differences in terms of coping strategies across shock types. The two relatively covariate

  9. Altered proteostasis in aging and heat shock response in C. elegans revealed by analysis of the global and de novo synthesized proteome.

    Science.gov (United States)

    Liang, Vanessa; Ullrich, Milena; Lam, Hong; Chew, Yee Lian; Banister, Samuel; Song, Xiaomin; Zaw, Thiri; Kassiou, Michael; Götz, Jürgen; Nicholas, Hannah R

    2014-09-01

    Protein misfolding and aggregation as a consequence of impaired protein homeostasis (proteostasis) not only characterizes numerous age-related diseases but also the aging process itself. Functionally related to the aging process are, among others, ribosomal proteins, suggesting an intimate link between proteostasis and aging. We determined by iTRAQ quantitative proteomic analysis in C. elegans how the proteome changes with age and in response to heat shock. Levels of ribosomal proteins and mitochondrial chaperones were decreased in aged animals, supporting the notion that proteostasis is altered during aging. Mitochondrial enzymes of the tricarboxylic acid cycle and the electron transport chain were also reduced, consistent with an age-associated energy impairment. Moreover, we observed an age-associated decline in the heat shock response. In order to determine how protein synthesis is altered in aging and in response to heat shock, we complemented our global analysis by determining the de novo proteome. For that, we established a novel method that enables both the visualization and identification of de novo synthesized proteins, by incorporating the non-canonical methionine analogue, azidohomoalanine (AHA), into the nascent polypeptides, followed by reacting the azide group of AHA by 'click chemistry' with an alkyne-labeled tag. Our analysis of AHA-tagged peptides demonstrated that the decreased abundance of, for example, ribosomal proteins in aged animals is not solely due to degradation but also reflects a relative decrease in their synthesis. Interestingly, although the net rate of protein synthesis is reduced in aged animals, our analyses indicate that the synthesis of certain proteins such as the vitellogenins increases with age.

  10. Radio frequency induced hyperthermia mediated by dextran stabilized LSMO nanoparticles: in vitro evaluation of heat shock protein response

    Science.gov (United States)

    Bhayani, K. R.; Rajwade, J. M.; Paknikar, K. M.

    2013-01-01

    Dextran stabilized La0.7Sr0.3MnO3 (Dex-LSMO) is an alternative cancer hyperthermia agent holding considerable promise. Here, we have carried out a comparative study on radio frequency (˜264 kHz) induced Dex-LSMO mediated heating and extraneous heating (mimicking generalized hyperthermia) in terms of changes in the morphology, proliferation pattern and induction of heat shock proteins in a human melanoma cell line (A375). Our results clearly show that the cellular effects seen with extraneous heating (60 min at 43 °C) could be reproduced by just six minutes of radio frequency induced Dex-LSMO mediated heating. More importantly, the observed enhanced levels of HSP 70 and 90 (molecular markers of heat shock that trigger favorable immunological reactions) seen with Dex-LSMO mediated heating were comparable to extraneous heating. These results suggest the possible utility of Dex-LSMO as a cancer hyperthermia agent.

  11. Radiation damage and thermal shock response of carbon-fiber-reinforced materials to intense high-energy proton beams

    OpenAIRE

    Simos, N; Z. Zhong; Ghose, S.; H. G. Kirk; L-P Trung; K. T. McDonald; Z. Kotsina; Nocera, P.; Assmann, R; Redaelli, S.; Bertarelli, A.; Quaranta, E.; Rossi, A.; Zwaska, R.; Ammigan, K.

    2017-01-01

    A comprehensive study on the effects of energetic protons on carbon-fiber composites and compounds under consideration for use as low-Z pion production targets in future high-power accelerators and low-impedance collimating elements for intercepting TeV-level protons at the Large Hadron Collider has been undertaken addressing two key areas, namely, thermal shock absorption and resistance to irradiation damage. Carbon-fiber composites of various fiber weaves have been widely used in aerospace ...

  12. Experimental Investigation into the Dynamic Response of Two DOF Tuned Deck Simulator for Shock Qualification of Shipboard Systems

    Science.gov (United States)

    1994-06-01

    System Natural Frequencies Using MATHCAD ( ...... 29 B FREQUENCIES OF SHOCK SPECTRAL PEAKS ............................... 29 1 . M eth o d s U tiliz e d...71 APPENDIX Cý MATLAB’ PROGRAMS AND MATHCAD " WORKSHEET ............ 73 A ppendix C .1 M odel A P P C 1 .M...75 Appendix C.3 MATHCAD ’ Worksheet: System Natural Frequencies ........... 81 L IST O F R E F E R E N C E S ............... 83

  13. Genetic divergence in cellular resistance to heat shock in cattle: differences between breeds developed in temperate versus hot climates in responses of preimplantation embryos, reproductive tract tissues and lymphocytes to increased culture temperatures.

    Science.gov (United States)

    Paula-Lopes, F F; Chase, C C; Al-Katanani, Y M; Krininger, C E; Rivera, R M; Tekin, S; Majewski, A C; Ocon, O M; Olson, T A; Hansen, P J

    2003-02-01

    The detrimental effects of heat stress on fertility in cattle are less pronounced in heat-tolerant breeds. Although these genetic differences reflect differences in thermoregulation, cells from heat-tolerant breeds are less adversely compromised by increased temperature (that is, heat shock) than cells from heat-sensitive breeds. Experiments were performed to test the hypothesis that cells and tissues from two thermotolerant breeds (Brahman and Senepol) are better able to survive and function after exposure to increased temperature than cells and tissues from two thermosensitive breeds (Holstein and Angus). Exposure of embryos at>eight-cell stage at day 5 after insemination to heat shock of 41.0 degrees C for 6 h decreased development to the blastocyst stage and the number of cells per embryo. However, the deleterious effect of heat shock on blastocyst formation and the number of cells per embryo was less pronounced for Brahman than for Holstein and Angus breeds. Embryos from Senepol cows had very low development and it was not possible to determine heat shock effects in this breed. In contrast to the sensitivity of embryos to heat shock, there was no effect of a 41.0 degrees C heat shock on [(3)H]leucine incorporation into proteins secreted by oviductal or endometrial explants. Lymphocytes from Brahman and Senepol cows were more resistant to heat-induced apoptosis than lymphocytes from other breeds. Heat shock reduced lymphocyte glutathione content but the magnitude of the decrease was not affected by breed. In conclusion, embryos from Brahman cows are more resistant to heat shock than embryos from Holstein or Angus cows. Genetic differences are also present in thermotolerance for apoptosis response in lymphocytes, with Brahman and Senepol cattle being more resistant to heat shock than Angus and Holstein breeds. It is likely that the evolutionary forces that led to the Brahman and Senepol breeds being adapted to hot climates resulted in the selection of genes

  14. Management of Refractory Vasodilatory Shock.

    Science.gov (United States)

    Jentzer, Jacob C; Vallabhajosyula, Saraschandra; Khanna, Ashish K; Chawla, Lakhmir S; Busse, Laurence W; Kashani, Kianoush B

    2018-01-09

    Refractory shock is a lethal manifestation of cardiovascular failure defined by an inadequate hemodynamic response to high doses of vasopressor medications. Approximately 7% of critically ill patients will develop refractory shock, with short-term mortality exceeding 50%. Refractory vasodilatory shock develops from uncontrolled vasodilation and vascular hyporesponsiveness to endogenous vasoconstrictors, causing failure of physiologic vasoregulatory mechanisms. Standard approaches to the initial management of shock include fluid resuscitation and initiation of norepinephrine. When these measures are inadequate to restore BP, vasopressin or epinephrine can be added. Few randomized studies exist to guide clinical management and hemodynamic stabilization in patients who do not respond to this standard approach. Adjunctive therapies, such as hydrocortisone, thiamine, and ascorbic acid, may increase BP in severe shock and should be considered when combination vasopressor therapy is needed. Novel vasopressor agents, such as synthetic human angiotensin II, can increase BP and reduce the need for high doses of catecholamine vasopressors in severe or refractory vasodilatory shock. Few effective rescue therapies exist for established refractory shock, which emphasizes the importance of aggressive intervention before refractory shock develops, including the earlier initiation of rational combination vasopressor therapy. The present review discusses the diagnosis and management of refractory shock to offer guidance for management of this important clinical problem and to provide a framework for future research. Copyright © 2018 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  15. Genome-Wide Characterization of Heat-Shock Protein 70s from Chenopodium quinoa and Expression Analyses of Cqhsp70s in Response to Drought Stress.

    Science.gov (United States)

    Liu, Jianxia; Wang, Runmei; Liu, Wenying; Zhang, Hongli; Guo, Yaodong; Wen, Riyu

    2018-01-23

    Heat-shock proteins (HSPs) are ubiquitous proteins with important roles in response to biotic and abiotic stress. The 70-kDa heat-shock genes (Hsp70s) encode a group of conserved chaperone proteins that play central roles in cellular networks of molecular chaperones and folding catalysts across all the studied organisms including bacteria, plants and animals. Several Hsp70s involved in drought tolerance have been well characterized in various plants, whereas no research on Chenopodium quinoa HSPs has been completed. Here, we analyzed the genome of C. quinoa and identified sixteen Hsp70 members in quinoa genome. Phylogenetic analysis revealed the independent origination of those Hsp70 members, with eight paralogous pairs comprising the Hsp70 family in quinoa. While the gene structure and motif analysis showed high conservation of those paralogous pairs, the synteny analysis of those paralogous pairs provided evidence for expansion coming from the polyploidy event. With several subcellular localization signals detected in CqHSP70 protein paralogous pairs, some of the paralogous proteins lost the localization information, indicating the diversity of both subcellular localizations and potential functionalities of those HSP70s. Further gene expression analyses revealed by quantitative polymerase chain reaction (qPCR) analysis illustrated the significant variations of Cqhsp70s in response to drought stress. In conclusion, the sixteen Cqhsp70s undergo lineage-specific expansions and might play important and varied roles in response to drought stress.

  16. Early Response Roles for Prolactin Cortisol and Circulating and Cellular Levels of Heat Shock Proteins 72 and 90α in Severe Sepsis and SIRS

    Science.gov (United States)

    Vardas, K.; Apostolou, K.; Briassouli, E.; Goukos, D.; Psarra, K.; Botoula, E.; Tsagarakis, S.; Magira, E.; Routsi, C.; Nanas, S.; Briassoulis, G.

    2014-01-01

    Objective. To evaluate the early heat shock protein (HSP) and hormonal stress response of intensive care unit (ICU) patients with severe sepsis/septic shock (SS) or systemic inflammatory response syndrome (SIRS) compared to healthy subjects (H). Methods. Patients with early (first 48 hrs) SS (n = 29) or SIRS (n = 29) admitted to a university ICU and 16 H were enrolled in the study. Serum prolactin, cortisol, and plasma ACTH were determined using immunoassay analyzers. ELISA was used to evaluate extracellular HSPs (eHSP90α, eHSP72) and interleukins. Mean fluorescence intensity (MFI) values for intracellular HSPs (iHSP72, iHSP90α) were measured using 4-colour flow-cytometry. Results. Prolactin, cortisol, and eHSP90α levels were significantly increased in SS patients compared to SIRS and H (P APACHE II scores and cortisol with eHSP90α, IL-6, and lactate (P < 0.05). In SS and SIRS eHSP90α was related with eHSP72, IL-6, and IL-10. Conclusion. Prolactin, apart from cortisol, may have a role in the acute stress response in severe sepsis. In this early-onset inflammatory process, cortisol relates to eHSP90α, monocytes suppress iHSP72, and plasma eHSP72 increases. PMID:25243181

  17. [Obstructive shock].

    Science.gov (United States)

    Pich, H; Heller, A R

    2015-05-01

    An acute obstruction of blood flow in central vessels of the systemic or pulmonary circulation causes the clinical symptoms of shock accompanied by disturbances of consciousness, centralization, oliguria, hypotension and tachycardia. In the case of an acute pulmonary embolism an intravascular occlusion results in an acute increase of the right ventricular afterload. In the case of a tension pneumothorax, an obstruction of the blood vessels supplying the heart is caused by an increase in extravascular pressure. From a hemodynamic viewpoint circulatory shock caused by obstruction is closely followed by cardiac deterioration; however, etiological and therapeutic options necessitate demarcation of cardiac from non-cardiac obstructive causes. The high dynamics of this potentially life-threatening condition is a hallmark of all types of obstructive shock. This requires an expeditious and purposeful diagnosis and a rapid and well-aimed therapy.

  18. IODINE REMOVAL EFFICIENCY IN NON-SUBMERGED AND SUBMERGED SELF-PRIMING VENTURI SCRUBBER

    OpenAIRE

    Ali, Majid; CHANGQI, YAN; ZHONGNING, SUN; HAIFENG, GU; JUNLONG, WANG; MEHBOOB, KHURRAM

    2013-01-01

    The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate (Na2S2O3) in water to remove the gaseous iodine (I2) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine...

  19. Tissue-specific induction of Hsp90 mRNA and plasma cortisol response in chinook salmon following heat shock, seawater challenge, and handling challenge

    Science.gov (United States)

    Palmisano, Aldo N.; Winton, J.R.; Dickhoff, Walton W.

    2000-01-01

    In studying the whole-body response of chinook salmon (Oncorhynchus tshawytscha) to various stressors, we found that 5-hour exposure to elevated temperature (mean 21.6??C; + 10.6??C over ambient) induced a marked increase in Hsp90 messenger RNA accumulation in heart, brain, gill, muscle, liver, kidney, and tail fin tissues. The most vital tissues (heart, brain, gill, and muscle) showed the greatest Hsp90-mRNA response, with heart tissue increasing approximately 35-fold, Heat shock induced no increase in plasma cortisol. In contrast, a standard handling challenge induced high plasma cortisol levels, but no elevation in Hsp90 mRNA in any tissue, clearly separating the physiological and cellular stress responses. We saw no increase either in tissue Hsp90 mRNA levels or in plasma cortisol concentrations after exposing the fish to seawater overnight.

  20. Toxic shock syndrome

    Science.gov (United States)

    Staphylococcal toxic shock syndrome; Toxic shock-like syndrome; TSLS ... Toxic shock syndrome is caused by a toxin produced by some types of staphylococcus bacteria. A similar problem, called toxic shock- ...

  1. Proteome changes in rainbow trout (Oncorhynchus mykiss) fertilized eggs as an effect of triploidization heat-shock treatment.

    Science.gov (United States)

    Babaheydari, Samad Bahrami; Keyvanshokooh, Saeed; Dorafshan, Salar; Johari, Seyed Ali

    2016-03-01

    The aim of the present study was to explore proteome changes in rainbow trout (Oncorhynchus mykiss) fertilized eggs as an effect of triploidization heat-shock treatment. Eggs and milt were taken from eight females and six males. The gametes were pooled to minimize the individual differences. After insemination, the eggs were incubated at 10°C for 10min. Half of the fertilized eggs were then subjected to heat shock for 10min submerged in a 28°C water bath to induce triploidy. The remainder were incubated normally and used as diploid controls. Three batches of eggs were randomly selected from each group and were incubated at 10-11°C under the same environmental conditions in hatchery troughs until the fry stage. Triplicate samples of 30 eggs (10 eggs per trough) from each group were randomly selected 1.5h post-fertilization for proteome extraction. Egg proteins were analyzed using two-dimensional electrophoresis (2-DE) and MALDI-TOF/TOF mass spectrometry. Based on the results from the statistical analyses, 15 protein spots were found to decrease significantly in abundance in heat-shock treated group and were selected for identification. Out of 15 protein spots showing altered abundance, 14 spots were successfully identified. All of the egg proteins identified in our study were related to vitellogenin (vtg). Decreased abundance of vitellogenin in heat-shock treated eggs in our study may either be explained by (i) higher utilization of vtg as an effect of increased cell size in triploids or (ii) changed metabolism in response to heat-shock stress and (iii) diffusion of vtg through chorion due to incidence of egg shell damage. Decreased abundance of vitellogenin in heat-shock treated eggs was associated with reduced early survival rates and lowered growth performance of triploid fish. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Effect of "heat shock" treatments on QPX disease and stress response in the hard clam, Mercenaria mercenaria.

    Science.gov (United States)

    Wang, Kailai; Pales Espinosa, Emmanuelle; Allam, Bassem

    2016-07-01

    The hard clam, Mercenaria mercenaria, is one of the most valuable commercial mollusk species along the eastern coast of the United States. Throughout the past 2 decades, the hard clam industry in the Northeast was significantly impacted by disease outbreaks caused by a lethal protistan parasite known as Quahog Parasite Unknown (QPX). QPX is an opportunistic pathogen and the infection has been shown to be a cold water disease, where warmer conditions (above 21°C) lead to disease reduction and clam healing. In vitro studies also showed a sharp reduction in parasite growth and survivorship at temperatures exceeding 27°C. In this study, we evaluated the effect of short-term exposures to high temperatures on QPX disease dynamic and clam recovery. Infected clams were collected from an enzootic site and subsequently submitted to one of ten "heat shock" treatments involving a gradient of temperatures and exposure times. QPX prevalence was compared before and 10weeks after heat shock to assess the effect of each treatment on disease progress. Expression of several stress-related genes was measured 1 and 7days after heat shock using qPCR to evaluate the effect of each treatment on clam physiology. Anti-QPX activity in clam plasma was also measured in an attempt to link changes in defense factors to thermal stress and disease progress. Our results suggest that brief exposures to moderate high temperatures promote the greatest remission while imposing the mildest stress to clams. These results are discussed with the aim of providing the industry with possible strategies to mitigate QPX disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Haemodynamic response to crystalloids or colloids in shock: an exploratory subgroup analysis of a randomised controlled trial.

    Science.gov (United States)

    Heming, Nicholas; Elatrous, Souheil; Jaber, Samir; Dumenil, Anne Sylvie; Cousson, Joël; Forceville, Xavier; Kimmoun, Antoine; Trouillet, Jean Louis; Fichet, Jérôme; Anguel, Nadia; Darmon, Michael; Martin, Claude; Chevret, Sylvie; Annane, Djillali

    2017-10-06

    To compare the haemodynamic effect of crystalloids and colloids during acute severe hypovolaemic shock. Exploratory subgroup analysis of a multicentre randomised controlled trial (Colloids Versus Crystalloids for the Resuscitation of the Critically Ill, CRISTAL, ClinicalTrials.gov NCT00318942). CRISTAL was conducted in intensive care units in Europe, North Africa and Canada. Current analysis included all patients who had a pulmonary artery catheter in place at randomisation. 220 patients (117 received crystalloids vs 103 colloids) underwent pulmonary artery catheterisation. Crystalloids versus colloids for fluid resuscitation in hypovolaemic shock. Haemodynamic data were collected at the time of randomisation and subsequently on days 1, 2, 3, 4, 5, 6 and 7. Median cumulative volume of fluid administered during the first 7 days was higher in the crystalloids group than in the colloids group (3500 (2000-6000) vs 2500 (1000-4000) mL, p=0.01). Patients in the colloids arm exhibited a lower heart rate over time compared with those allocated to the crystalloids arm (p=0.014). There was no significant difference in Cardiac Index (p=0.053), mean blood pressure (p=0.4), arterial lactates (p=0.9) or global Sequential Organ Failure Assessment score (p=0.3) over time between arms. During acute severe hypovolaemic shock, patients monitored by a pulmonary artery catheter achieved broadly similar haemodynamic outcomes, using lower volumes of colloids than crystalloids. The heart rate was lower in the colloids arm. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  4. “The response of stromatolites to seismic shocks: Tomboliths from the Palaeoproterozoic Chaibasa Formation, E India”: Reply

    Directory of Open Access Journals (Sweden)

    A.J. (Tom van Loon

    2017-07-01

    Full Text Available Our contribution about a newly recognized sedimentological feature, which we called tombolith, has raised some comments on the etymology of the term, the assumed lack of field data, the usage of a term that has a special meaning in stratigraphy, the origin of the seismic shocks that played a role, so-called basic tenets, the origin of soft-sediment deformation structures, and the role of liquefaction. We argue that most comments result from an insufficiently thorough reading of our text, whereas some other remarks concern aspects that we did not deal with. Finally, several remarks are based on outdated literature and from insufficient knowledge of the regional geology.

  5. First report on heat shock protein expression in red spider mites (Oligonychus coffeae) in response to pesticide exposure

    OpenAIRE

    AK Prasad; G Handique; Barua, A.; Roy, S.

    2016-01-01

    ISJ 13: 350-354, 2016 ISSN 1824-307X Red spider mites (RSM) is one of the major pest of tea and reported from all tea producing regions around the world. Chemical acaricides are the primary control method against this pest which induced biochemical changes in the RSM. In this study early expression of heat shock proteins have been observed in RSM exposed to commonly used acaricides viz., ethion, dicofol and fenpropathrin. In case of pesticide exposed RSM, hsp90 showed more pr...

  6. Calibration of submerged multi-sluice gates

    Directory of Open Access Journals (Sweden)

    Mohamed F. Sauida

    2014-09-01

    The main objective of this work is to study experimentally and verify empirically the different parameters affecting the discharge through submerged multiple sluice gates (i.e., the expansion ratios, gates operational management, etc.. Using multiple regression analysis of the experimental results, a general equation for discharge coefficient is developed. The results show, that the increase in the expansion ratio and the asymmetric operation of gates, give higher values for the discharge coefficient. The obtained predictions of the discharge coefficient using the developed equations are compared to the experimental data. The present developed equations showed good consistency and high accuracy.

  7. The Transcriptional Heat Shock Response of Salmonella Typhimurium Shows Hysteresis and Heated Cells Show Increased Resistance to Heat and Acid Stress

    DEFF Research Database (Denmark)

    Pin, C.; Hansen, Trine; Munoz-Cuevas, M.

    2012-01-01

    We investigated if the transcriptional response of Salmonella Typhimurium to temperature and acid variations was hysteretic, i.e. whether the transcriptional regulation caused by environmental stimuli showed memory and remained after the stimuli ceased. The transcriptional activity of non.......e., they remained up-regulated after the environmental stress ceased. At 25uC the transcriptional regulation of genes encoding for heat shock proteins was determined by the previous environment. Gene networks constructed with up-regulated genes were significantly more modular than those of down-regulated genes......H 4.5 were not affected. The exposure to pH 5 only caused up-regulation of 12 genes and this response was neither hysteretic nor accompanied of increased resistance to inactivation conditions. Cellular memory at the transcriptional level may represent a mechanism of adaptation to the environment...

  8. Shock Waves

    CERN Document Server

    Jiang, Z

    2005-01-01

    The International Symposium on Shock Waves (ISSW) is a well established series of conferences held every two years in a different location. A unique feature of the ISSW is the emphasis on bridging the gap between physicists and engineers working in fields as different as gas dynamics, fluid mechanics and materials sciences. The main results presented at these meetings constitute valuable proceedings that offer anyone working in this field an authoritative and comprehensive source of reference.

  9. Damage detection in submerged plates using ultrasonic guided waves

    Indian Academy of Sciences (India)

    Suitable ultrasonic guided wave modes with optimum scanning capabilities have been generated and identified in submerged plate system. Finally, the propagation of selected modes through submerged notched plates is investigated. Sensitivity of leaky waves to the notches has been studied. The methodology would help ...

  10. Automating a submerged pump method for operating oil wells

    Energy Technology Data Exchange (ETDEWEB)

    Popa, I.

    1984-01-01

    The basic parameters of wells which operate in a mode of submerged operation are presented. The basic systems for measuring and testing the parameters of submerged operation are described. Worldwide experience in solving this particular problem is analyzed. Romanian (SRR) use of systems for automation, remote signaling and remote management is examined.

  11. Early Response Roles for Prolactin Cortisol and Circulating and Cellular Levels of Heat Shock Proteins 72 and 90α in Severe Sepsis and SIRS

    Directory of Open Access Journals (Sweden)

    K. Vardas

    2014-01-01

    Full Text Available Objective. To evaluate the early heat shock protein (HSP and hormonal stress response of intensive care unit (ICU patients with severe sepsis/septic shock (SS or systemic inflammatory response syndrome (SIRS compared to healthy subjects (H. Methods. Patients with early (first 48 hrs SS (n=29 or SIRS (n=29 admitted to a university ICU and 16 H were enrolled in the study. Serum prolactin, cortisol, and plasma ACTH were determined using immunoassay analyzers. ELISA was used to evaluate extracellular HSPs (eHSP90α, eHSP72 and interleukins. Mean fluorescence intensity (MFI values for intracellular HSPs (iHSP72, iHSP90α were measured using 4-colour flow-cytometry. Results. Prolactin, cortisol, and eHSP90α levels were significantly increased in SS patients compared to SIRS and H (P<0.003. ACTH and eHSP72 were significantly higher in SS and SIRS compared to H (P<0.005. SS monocytes expressed lower iHSP72 MFI levels compared to H (P=0.03. Prolactin was related with SAPS III and APACHE II scores and cortisol with eHSP90α, IL-6, and lactate (P<0.05. In SS and SIRS eHSP90α was related with eHSP72, IL-6, and IL-10. Conclusion. Prolactin, apart from cortisol, may have a role in the acute stress response in severe sepsis. In this early-onset inflammatory process, cortisol relates to eHSP90α, monocytes suppress iHSP72, and plasma eHSP72 increases.

  12. Real-time cell analysis and heat shock protein gene expression in the TcA Tribolium castaneum cell line in response to environmental stress conditions.

    Science.gov (United States)

    García-Reina, Andrés; Rodríguez-García, María Juliana; Ramis, Guillermo; Galián, José

    2017-06-01

    The rust red flour beetle, Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae), is a pest of stored grain and one of the most studied insect model species. Some of the previous studies involved heat response studies in terms of survival and heat shock protein expression, which are regulated to protect other proteins against environmental stress conditions. In the present study, we characterize the impedance profile with the xCELLigence Real-Time Cell Analyzer and study the effect of increased temperature in cell growth and viability in the cell line BCIRL-TcA-CLG1 (TcA) of T. castaneum. This novel system measures cells behavior in real time and is applied for the first time to insect cells. Additionally, cells are exposed to heat shock, increased salinity, acidic pH and UV-A light with the aim of measuring the expression levels of Hsp27, Hsp68a, and Hsp83 genes. Results show a high thermotolerance of TcA in terms of cell growth and viability. This result is likely related to gene expression results in which a significant up-regulation of all studied Hsp genes is observed after 1 h of exposure to 40 °C and UV light. All 3 genes show similar expression patterns, but Hsp27 seems to be the most affected. The results of this study validate the RTCA method and reveal the utility of insect cell lines, real-time analysis and gene expression studies to better understand the physiological response of insect cells, with potential applications in different fields of biology such as conservation biology and pest management. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  13. Laser-matter Interaction with Submerged Samples

    Energy Technology Data Exchange (ETDEWEB)

    Mariella, R; Rubenchik, A; Norton, M; Donohue, G; Roberts, K

    2010-03-25

    With the long-term goal in mind of investigating if one could possibly design a 'universal solid-sample comminution technique' for debris and rubble, we have studied pulsed-laser ablation of solid samples that were contained within a surrounding fluid. Using pulses with fluences between 2 J and 0.3 J, wavelengths of 351 and 527 nm, and samples of rock, concrete, and red brick, each submerged in water, we have observed conditions in which {micro}m-scale particles can be preferentially generated in a controlled manner, during the laser ablation process. Others have studied laser peening of metals, where their attention has been to the substrate. Our study uses non-metallic substrates and analyzes the particles that are ablated from the process. The immediate impact of our investigation is that laser-comminution portion of a new systems concept for chemical analysis has been verified as feasible.

  14. Submerged arc welding of heavy plate

    Science.gov (United States)

    Wilson, R. A.

    1972-01-01

    The submerged arc process is particularly suitable for heavy plate welding because of its ability to combine very high deposit rates along with excellent quality. It does these things without the smoke and spatter often accompanying other processes. It is available today in several forms that are pointed to the fabricators of heavy sections with long, short or round about welds. Tandem arc full automatic equipment is particularly suitable for those long heavy welds where speed and deposit rate are of the first order. An attachment called long stick-out which makes use of the IR drop on long electrode extensions can be included on this equipment to increase deposition rates 50% or more.

  15. Modeling tabular icebergs submerged in the ocean

    Science.gov (United States)

    Stern, A. A.; Adcroft, A.; Sergienko, O.; Marques, G.

    2017-08-01

    Large tabular icebergs calved from Antarctic ice shelves have long lifetimes (due to their large size), during which they drift across large distances, altering ambient ocean circulation, bottom-water formation, sea-ice formation, and biological primary productivity in the icebergs' vicinity. However, despite their importance, the current generation of ocean circulation models usually do not represent large tabular icebergs. In this study, we develop a novel framework to model large tabular icebergs submerged in the ocean. In this framework, tabular icebergs are represented by pressure-exerting Lagrangian elements that drift in the ocean. The elements are held together and interact with each other via bonds. A breaking of these bonds allows the model to emulate calving events (i.e., detachment of a tabular iceberg from an ice shelf) and tabular icebergs breaking up into smaller pieces. Idealized simulations of a calving tabular iceberg, its drift, and its breakup demonstrate capabilities of the developed framework.

  16. Crassulacean acid metabolism in submerged aquatic plants

    Science.gov (United States)

    Keeley, Jon E.; Sybesme, C.

    1984-01-01

    CO2-fixation in the dark is known to occur in various organs of many plants. However, only in species possessing crassulacean acid metabolism (CAM) does dark CO2-fixation contribute substantially to the carbon economy of the plant. Until very recently CAM was known only from terrestrial species, largely drought adapted succulents. The discovery of CAM in the submerged aquatic fern ally Isoetes howellii (Isoetaceae)(Keeley 1981) adds a new dimension to our understanding of crassulacean acid metabolism. In this paper I will summarize 1) the evidence of CAM in Isoetes howellii, 2) the data on the distribution of CAM in aquatic species, and 3) the work to date on the functional significance of CAM in aquatic species.

  17. Dynamic Behaviour of Submerged Floating Tunnels under Seismic Loadings with Different Cable Configurations

    Directory of Open Access Journals (Sweden)

    Endah Wahyuni

    2012-05-01

    Full Text Available The paper presents the dynamic behavior of a Submerged Floating Tunnel (SFT in the Seribu Archipelago crossing under seismic loadings by using the different cable configurations. The SFT is a tubular structure submerged in the water at a fixed depth, which features several advantages from the structural and environmental impact points of view. In particular, the structural system is suited for waterway crossings in seismicity zones. Its interaction with the water provides additional damping and inertia to the system. To evaluate the SFT structural response of seismic loadings, a response spectrum analyses were carried out, in which the ground multi-support excitation is considered. The investigation of the different cable system configurations were also carried out. Both static and dynamic analyses were carried to find the optimal configuration of the structural system. Although the paper has had a definitive conclusion yet, the results gave useful indications of responses of Submerged Floating Tunnels subjected to earthquake. The SFT with two cable diagonals perpendicular with SFT’s body (called Model C shows the optimal structural configuration compared with others.

  18. Workshop on ROVs and deep submergence

    Science.gov (United States)

    The deep-submergence community has an opportunity on March 6 to participate in a unique teleconferencing demonstration of a state-of-the-art, remotely operated underwater research vehicle known as the Jason-Medea System. Jason-Medea has been developed over the past decade by scientists, engineers, and technicians at the Deep Submergence Laboratory at Woods Hole Oceanographic Institution. The U.S. Navy, the Office of the Chief of Naval Research, and the National Science Foundation are sponsoring the workshop to explore the roles that modern computational, communications, and robotics technologies can play in deep-sea oceanographic research.Through the cooperation of Electronic Data Systems, Inc., the Jason Foundation, and Turner Broadcasting System, Inc., 2-1/2 hours of air time will be available from 3:00 to 5:30 PM EST on March 6. Twenty-seven satellite downlink sites will link one operating research vessel and the land-based operation with workshop participants in the United States, Canada, the United Kingdom, and Bermuda. The research ship Laney Chouest will be in the midst of a 3-week educational/research program in the Sea of Cortez, between Baja California and mainland Mexico. This effort is focused on active hydrothermal vents driven by heat flow from the volcanically active East Pacific Rise, which underlies the sediment-covered Guaymas Basin. The project combines into a single-operation, newly-developed robotic systems, state-of-the-art mapping and sampling tools, fiber-optic data transmission from the seafloor, instantaneous satellite communication from ship to shore, and a sophisticated array of computational and telecommunications networks. During the workshop, land-based scientists will observe and participate directly with their seagoing colleagues as they conduct seafloor research.

  19. Submerged membrane distillation for seawater desalination

    KAUST Repository

    Francis, Lijo

    2014-08-11

    A submerged membrane distillation (SMD) process for fresh water production from Red Sea water using commercially available hollow fiber membranes has been successfully employed and compared with the conventional direct contact membrane distillation (DCMD) process. The hollow fiber membranes have been characterized for its morphology using field effect scanning electron microscope. In SMD process, a bunch of hollow fiber membranes are glued together at both ends to get a simplified open membrane module assembly submerged into the coolant tank equipped with a mechanical stirrer. Hot feed stream is allowed to pass through the lumen side of the membrane using a feed pump. Continuous stirring at the coolant side will reduce the temperature and concentration polarization. During the conventional DCMD process, using feed-coolant streams with co-current and counter-current flows has been tested and the results are compared in this study. In SMD process, a water vapor flux of 10.2 kg m-2 h-1 is achieved when using a feed inlet temperature of 80°C and coolant temperature of 20°C. Under the same conditions, during conventional DCMD process, a water vapor flux of 11.6 and 10.1 kg m-2 h-1 were observed during counter-current and co-current flow streams, respectively. Results show that the water production in the SMD process is comparable with the conventional DCMD process, while the feed-coolant flow streams are in the co-current direction. During conventional DCMD operation, a 15% increase in the water production is observed when feed-coolant streams are in the counter-current direction compared to the co-current direction. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

  20. Pediatric cardiogenic shock: Current perspectives

    Directory of Open Access Journals (Sweden)

    Subhranshu Sekhar Kar

    2015-01-01

    Full Text Available Cardiogenic shock is a pathophysiologic state where an abnormality of cardiac function is responsible for the failure of the cardiovascular system to meet the metabolic needs of the body tissues.Though it is less common than hypovolemia as the primary etiology in paediatric shock, eventually myocardial function is affected because of reduced perfusion in all forms of shock. Myocardial malfunction, in other forms of shock, is secondary to ischemia, acidosis, drugs, toxins or inflammation. Cardiogenic shock is a low output state characterized by elevated filling pressures, neurohormonal activation with the evidence of end-organ hypoperfusion. The management is challenging and consists of a combination of conventional cardio-respiratory support, vasoactive medications with correction of the anatomic cardiac defects. Treatment options like Extracorporeal membrane oxygenation and Ventricular assist devices provide a bridge to recovery, surgery or transplant. As cardiogenic shock in children carries a high risk of morbidity and mortality, emphasis should be placed on expedient management to arrest the pathophysiological cascade and avoid hypotension.This article aims to review the aetio-pathophysiological basis of pediatric cardiogenic shock, diagnostic options, recent advances in management modalities and outcome.

  1. Inorganic zinc supplementation modulates heat shock and immune response in heat stressed peripheral blood mononuclear cells of periparturient dairy cows.

    Science.gov (United States)

    Sheikh, Aasif Ahmad; Aggarwal, Anjali; B, Indu; Aarif, Ovais

    2017-06-01

    Thermal stress in India is one of the major constraints affecting dairy cattle productivity. Every attempt should be made to ameliorate the heat and calving related stress in high producing dairy cows for higher economic returns. In the current study, inorganic zinc was tried to alleviate the adverse effects of thermal stress in periparturient cows. Twelve cows, six each of Sahiwal and Karan Fries (KF) in their second parity with confirmed pregnancy were chosen for the experiment. The blood samples were collected periparturiently on three occasions viz. -21, 0 and +21 days relative to calving. The in vitro study was conducted after isolating peripheral blood mononuclear cells (PBMC) from whole blood. The cultured PBMC were subjected to three different levels of exposures viz. 37°C as control, 42°C to induce thermal stress and 42°C + zinc to ameliorate the adverse effects of high temperature. Heat shock lead to a significant (Pdairy cows. The study could help to alleviate the heat stress and potentiate immunity by providing mineral supplements in periparturient dairy cattle habituating tropics. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Geomagnetic avtivity triggered by interplanetary shocks: The shock impact angle as a controlling factor

    Science.gov (United States)

    Oliveira, D. M.; Raeder, J.; Tsurutani, B.; Gjerloev, J. W.

    2015-12-01

    We study the influence of interplanetary (IP) shock impact angles in the shock geoeffectiveness focusing on simulations and observations. In our simulations, we use OpenGGCM simulations to study the magnetospheric and ionospheric responses to shock impacts. Three cases are presented here: two inclined shocks, with 3.7 and 7.4 Mach numbers, and a frontal shock, whose shock normal is along the Sun-Earth line, with Mach number of 7.4. We find that, in the two inclined cases, due to the north-south asymmetry, the magnetotail is deflected southward, leading to a mild compression. The geomagnetic activity observed in the nightside ionosphere is then weak. On the other hand, in the head-on case, the magnetotail is compressed from both sides symmetrically. This compression triggers a substorm. By comparing the strong inclined shock and the frontal shock, we find that, despite the inclined shock having a larger Mach number, the frontal shock leads to a larger geomagnetic response in the nightside ionosphere. As a result, we conclude that IP shocks with similar upstream conditions, such as Mach number, can have different geoeffectiveness, depending on their shock normal orientation. In our observational study, we present a survey of IP shocks at 1 AU using Wind and ACE satellite data from Jan 1995 to Dec 2013 to study the same shock-related effects. A shock list covering one and a half solar cycle is compiled. We use data from SuperMAG, a large chain with more than 300 geomagnetic stations, to study geoeffectiveness triggered by IP shocks. The SuperMAG SML index (enhanced AL index), is used to quantify substorm strength. The jumps of the SML index triggered by shock impacts is investigated in terms of shock orientation and speed. We find that, in general, strong and almost frontal shocks are more geoeffective than inclined shocks with low speed. The highest correlations (R = 0.78) occurs for fixed shock speed and varying the shock impact angle. We attribute this result

  3. Multi-Objective Optimization of Submerged Arc Welding Process

    Directory of Open Access Journals (Sweden)

    Saurav Datta

    2010-06-01

    Full Text Available Submerged arc welding (SAW is an important metal fabrication technology specially applied to join metals of large thickness in a single pass. In order to obtain an efficient joint, several process parameters of SAW need to be studied and precisely selected to improve weld quality. Many methodologies were proposed in the past research to address this issue. However, a good number of past work seeks to optimize SAWprocess parameters with a single response only. In practical situations, not only is the influence of process parameters and their interactive effects on output responses are to be critically examined but also an attempt is to be made to optimize more than one response, simultaneously. To this end, the present study considers four process control parameters viz. voltage (OCV, wire feed rate, traverse speed and electrode stick-out. The selected weld quality characteristics related to features of bead geometry are depth of penetration, reinforcement and bead width. In the present reporting, an integrated approach capable of solving the simultaneous optimization of multi-quality responses in SAW was suggested. In the proposed approach, the responses were transformed into their individual desirability values by selecting appropriate desirability function. Assuming equal importance for all responses, these individual desirability values were aggregated to calculate the overall desirability values. Quadratic Response Surface Methodology (RSM was applied to establish a mathematical model representing overall desirability as a function involving linear, quadratic and interaction effect of process control parameters. This model was optimized finally within the experimental domain using PSO (Particle Swarm Optimization algorithm. A confirmatory test showed a satisfactory result. A detailed methodology of RSM, desirability function (DF and a PSO-based optimization approach was illustrated in the paper.

  4. Submerged Conidiation and Product Formation by Aspergillus niger at Low Specific Growth Rates Are Affected in Aerial Developmental Mutants

    DEFF Research Database (Denmark)

    Jørgensen, Thomas R.; Nielsen, Kristian Fog; Arentshorst, Mark

    2011-01-01

    . fwnA encodes the polyketide synthase responsible for melanin biosynthesis during aerial differentiation, and we show that conidial melanin synthesis in submerged retentostat cultures and aurasperone B production are fwnA dependent. The scl-1 and scl-2 strains are two UV mutants generated in the Δfwn...

  5. The Shock Routine

    DEFF Research Database (Denmark)

    van Hooren, Franca; Kaasch, Alexandra; Starke, Peter

    2014-01-01

    The idea that moments of crisis form opportunities for fundamental policy change is widespread in political science and public policy. It is usually associated with historical institutionalism and the notion of ‘critical junctures’. On the basis of an in-depth analysis of social policy responses...... in Australia, Belgium, the Netherlands and Sweden over the course of four global economic shocks, we ask whether the notion of critical junctures is useful in understanding the nature of change triggered by crisis. The main empirical finding is that fundamental change in the aftermath of an exogenous shock...... is the exception rather than the rule. Instead, incremental ‘crisis routines’ based on existing policy instruments are overwhelmingly used to deal with economic hardship. We discuss these findings in the light of the psychological ‘threat-rigidity’ effect and reflect on their consequences for theories...

  6. Shock-induced deformation twinning in tantalum

    Energy Technology Data Exchange (ETDEWEB)

    Murr, L.E.; Niou, C.S.; Pappu, S.; Kennedy, C. [Univ. of Texas, El Paso, TX (United States). Dept. of Metallurgical and Materials Engineering; Meyers, M.A.; Chen, Y.J. [Univ. of California, San Diego, La Jolla, CA (United States). Dept. of Applied Mechanics and Engineering Sciences

    1997-01-01

    Shock-wave deformation of tantalum to a pressure of 45 GPa and duration of 1.8 {micro}s generates profuse twinning. The post-shock mechanical response is significantly affected, with shock hardening exceeding the expected hardening due to the transient shock strain {epsilon}{sub s} = (4/3)ln(V/V{sub 0}); this enhanced hardening, and other alterations in response, are attributed to the barriers presented to plastic deformation by the deformation twins. A constitutive model is proposed that predicts the threshold shock stress for mechanical twinning; it is based on the application of the Swegle-Grady relationship between shock stress and strain rate to constitute equations describing the critical stress for slip and twinning. This constitutive model incorporates grain-size effects and predicts a threshold twinning stress that is a function of temperature and grain size; predictions of the model are in qualitative agreement with experimental results.

  7. Heat shock protein 27 is a potential indicator for response to YangZheng XiaoJi and chemotherapy agents in cancer cells.

    Science.gov (United States)

    Owen, Sioned; Zhao, Huishan; Dart, Alwyn; Wang, Yamei; Ruge, Fiona; Gao, Yong; Wei, Cong; Wu, Yiling; Jiang, Wen G

    2016-11-01

    Heat shock protein 27 (HSP27) is a member of the heat shock protein family which has been linked to tumour progression and, most interestingly, to chemotherapy resistance in cancer patients. The present study examined the potential interplay between HSP27 and YangZheng XiaoJi, a traditional Chinese medicine used in cancer treatment. A range of cell lines from different tumour types including pancreatic, lung, gastric, colorectal, breast, prostate and ovarian cancer (both wild-type and resistant) were used. Levels and activation of HSP27 and its potential associated signalling pathways were evaluated by protein array and western blotting. Knockdown of HSP27 in cancer cells was achieved using siRNA. Localisation and co-localisation of HSP27 and other proteins were carried out by immunofluorescence. Cell growth and migration were evaluated in their response to a range of chemotherapeutic agents. The present study first identified, by way of protein array, that YangZheng XiaoJi was able to inhibit the phosphorylation of HSP27 protein in cancer cells. We further demonstrated that HSP27, which is co-localised with caspase-9, can be blocked from localising in focal adhesions and co-localising with caspase-9 by YangZheng XiaoJi. The study also demonstrated that YangZheng XiaoJi was able to sensitise cancer cells including those cells that were resistant to chemotherapy, to chemotherapeutic agents. Finally, knocking down HSP27 markedly reduced the migration of cancer cells and increased the sensitivity of cancer cells to the inhibitory effect on cellular migration by YangZheng XiaoJi. YangZheng XiaoJi can act as an agent in first sensitising cancer cells to chemotherapy and secondly to overcome, to some degree, chemoresistance when used in an appropriate fashion in patients who have active HSP27.

  8. Geometrical shock dynamics of fast magnetohydrodynamic shocks

    Science.gov (United States)

    Mostert, Wouter; Pullin, Dale I.; Samtaney, Ravi; Wheatley, Vincent

    2016-11-01

    We extend the theory of geometrical shock dynamics (GSD, Whitham 1958), to two-dimensional fast magnetohydrodynamic (MHD) shocks moving in the presence of nonuniform magnetic fields of general orientation and strength. The resulting generalized area-Mach number rule is adapted to MHD shocks moving in two spatial dimensions. A partially-spectral numerical scheme developed from that of Schwendeman (1993) is described. This is applied to the stability of plane MHD fast shocks moving into a quiescent medium containing a uniform magnetic field whose field lines are inclined to the plane-shock normal. In particular, we consider the time taken for an initially planar shock subject to an initial perturbed magnetosonic Mach number distribution, to first form shock-shocks. Supported by KAUST OCRF Award No. URF/1/2162-01.

  9. Localized shocks

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, Daniel A. [Center for Theoretical Physics and Department of Physics,Massachusetts Institute of Technology, Cambridge, MA (United States); Stanford, Douglas [Stanford Institute for Theoretical Physics and Department of Physics,Stanford University, Stanford, CA (United States); School of Natural Sciences, Institute for Advanced Study,Princeton, NJ (United States); Susskind, Leonard [Stanford Institute for Theoretical Physics and Department of Physics,Stanford University, Stanford, CA (United States)

    2015-03-10

    We study products of precursors of spatially local operators, W{sub x{sub n}}(t{sub n})…W{sub x{sub 1}}(t{sub 1}), where W{sub x}(t)=e{sup −iHt}W{sub x}e{sup iHt}. Using chaotic spin-chain numerics and gauge/gravity duality, we show that a single precursor fills a spatial region that grows linearly in t. In a lattice system, products of such operators can be represented using tensor networks. In gauge/gravity duality, they are related to Einstein-Rosen bridges supported by localized shock waves. We find a geometrical correspondence between these two descriptions, generalizing earlier work in the spatially homogeneous case.

  10. Pyrotechnic Shock Analysis Using Statistical Energy Analysis

    Science.gov (United States)

    2015-10-23

    29th Aerospace Testing Seminar, October 2015 Pyrotechnic Shock Analysis Using Statistical Energy Analysis James Ho-Jin Hwang Engineering...maximum structural response due to a pyrotechnic shock input using Statistical Energy Analysis (SEA). It had been previously understood that since the...pyrotechnic shock is not a steady state event, traditional SEA method may not applicable. A new analysis methodology effectively utilizes the

  11. Durability performance of submerged concrete structures - phase 2.

    Science.gov (United States)

    2015-09-01

    This project determined that severe corrosion of steel can occur in the submerged : portions of reinforced concrete structures in marine environments. Field studies of decommissioned : pilings from Florida bridges revealed multiple instances of stron...

  12. Submerged Aquatic Vegetation of Bogue Sound, North Carolina 1992 Geodatabase

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1992, 1:20,000 scale aerial photography for Bogue Sound, North Carolina was collected as part of an effort to map submerged aquatic vegetation (SAV) in...

  13. Submerged Aquatic Vegetation of Bogue Sound, North Carolina 1992 Substrate

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1992, 1:20,000 scale aerial photography for Bogue Sound, North Carolina was collected as part of an effort to map submerged aquatic vegetation (SAV) in...

  14. Marine algal flora of submerged Angria Bank (Arabian Sea)

    Digital Repository Service at National Institute of Oceanography (India)

    Untawale, A.G.; Reddy, C.R.K.; Ambiye, V.

    Submerged Angria Bank was surveyed for the deep water marine algal flora. About 57 species were reported from this bank for the first time. Rhodophyta dominated (30 species) followed by Chlorophyta (18 species) and Phaeophyta (9 species). A few...

  15. Submerged Aquatic Vegetation of Bogue Sound, North Carolina 1992 Biotic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1992, 1:20,000 scale aerial photography for Bogue Sound, North Carolina was collected as part of an effort to map submerged aquatic vegetation (SAV) in...

  16. Submerged Aquatic Vegetation of Bogue Sound, North Carolina 1992 Geoform

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During 1992, 1:20,000 scale aerial photography for Bogue Sound, North Carolina was collected as part of an effort to map submerged aquatic vegetation (SAV) in...

  17. Supporting Calculations For Submerged Bed Scrubber Condensate Disposal Preconceptual Study

    Energy Technology Data Exchange (ETDEWEB)

    Pajunen, A. J.; Tedeschi, A. R.

    2012-09-18

    This document provides supporting calculations for the preparation of the Submerged Bed Scrubber Condensate Disposal Preconceptual Study report The supporting calculations include equipment sizing, Hazard Category determination, and LAW Melter Decontamination Factor Adjustments.

  18. Evolution of the reflection and focusing patterns and stress states in two-fluid cylindrical shell systems subjected to an external shock wave

    Science.gov (United States)

    Iakovlev, S.; Dooley, G.; Williston, K.; Gaudet, J.

    2011-12-01

    Several most important features of the hydrodynamic field induced inside a circular cylindrical shell filled with and submerged into different fluids when it is subjected to an external shock wave are considered. This investigation is a follow-up of an earlier study of the two-fluid shell-shock interaction [S. Iakovlev, Interaction between an external shock wave and a cylindrical shell filled with and submerged into different fluids, Journal of Sound and Vibration 322 (2009) 401-437], and it addresses a number of practically important issues not covered in that work. The focus of this study is on the evolution of the respective hydrodynamic patterns in response to the continuous change of the parameters of the fluids, in particular the speed of sound. Along with the analysis of the hydrodynamic patterns it is also demonstrated that when one is concerned with the highest pressure attained inside the shell, the most dangerous combination of the parameters occurs when the ratio of the internal and external acoustic speeds is close to 0.48, with the respective pressure exceeding the maximum incident pressure by more than 110 percent. The effect that the hydrodynamic features discussed have on the stress state of the shell is addressed as well, and it is observed that the maximum tensile stress is significantly affected by the evolution of the considered hydrodynamic features, whereas the maximum compressive stress is not. It is also observed that the maximum tensile stress is very sensitive to the change of the ratio of the acoustic speeds in the internal and external fluids, with as little an increase of the latter as 13 percent resulting in more than doubling of the former in some cases.

  19. Impeded Carbohydrate Metabolism in Rice Plants under Submergence Stress

    Directory of Open Access Journals (Sweden)

    Malay Kumar ADAK

    2011-06-01

    Full Text Available The detrimental effects of submergence on physiological performances of some rice varieties with special references to carbohydrate metabolisms and their allied enzymes during post-flowering stages have been documented and clarified in the present investigation. It was found that photosynthetic rate and concomitant translocation of sugars into the panicles were both related to the yield. The detrimental effects of the complete submergence were recorded in generation of sucrose, starch, sucrose phosphate synthase and phosphorylase activity in the developing panicles of the plants as compared to those under normal or control (i.e. non-submerged condition. The accumulation of starch was significantly lower in plants under submergence and that was correlated with ADP-glucose pyrophosphorylase activity. Photosynthetic rate was most affected under submergence in varying days of post-flowering and was also related to the down regulation of Ribulose bisphosphate carboxylase activity. However, under normal or control condition, there recorded a steady maintenance of photosynthetic rate at the post-flowering stages and significantly higher values of Ribulose bisphosphate carboxylase activity. Still, photosynthetic rate of the plants under both control and submerged conditions had hardly any significant correlation with sugar accumulation and other enzymes of carbohydrate metabolism like invertase with grain yield. Finally, plants under submergence suffered significant loss of yield by poor grain filling which was related to impeded carbohydrate metabolism in the tissues. It is evident that loss of yield under submergence is attributed both by lower sink size or sink capacity (number of panicles, in this case as well as subdued carbohydrate metabolism in plants and its subsequent partitioning into the grains.

  20. Incipient motion of sediment in presence of submerged flexible vegetation

    OpenAIRE

    Wang, Hao; Tang, Hong-Wu; Zhao, Han-Qing; Xuan-yu ZHAO; Lü, Sheng-qi

    2015-01-01

    The presence of submerged vegetation on river beds can change the water flow structure and alter the state of sediment motion. In this study, the incipient motion of sediment in the presence of submerged flexible vegetation in open channels was investigated in a laboratory experiment. The vegetation was simulated with flexible rubber cylinders arranged in parallel arrays. The effect of the vegetation density, water depth, and sediment grain size on the incipient motion was investigated. The e...

  1. Nodulin 22, a novel small heat-shock protein of the endoplasmic reticulum, is linked to the unfolded protein response in common bean.

    Science.gov (United States)

    Rodriguez-López, Jonathan; Martínez-Centeno, Cynthia; Padmanaban, Annamalai; Guillén, Gabriel; Olivares, Juan Elías; Stefano, Giovanni; Lledías, Fernando; Ramos, Fernando; Ghabrial, Said A; Brandizzi, Federica; Rocha-Sosa, Mario; Díaz-Camino, Claudia; Sanchez, Federico

    2014-01-01

    The importance of plant small heat shock proteins (sHsp) in multiple cellular processes has been evidenced by their unusual abundance and diversity; however, little is known about their biological role. Here, we characterized the in vitro chaperone activity and subcellular localization of nodulin 22 of Phaseolus vulgaris (PvNod22; common bean) and explored its cellular function through a virus-induced gene silencing-based reverse genetics approach. We established that PvNod22 facilitated the refolding of a model substrate in vitro, suggesting that it acts as a molecular chaperone in the cell. Through microscopy analyses of PvNod22, we determined its localization in the endoplasmic reticulum (ER). Furthermore, we found that silencing of PvNod22 resulted in necrotic lesions in the aerial organs of P. vulgaris plants cultivated under optimal conditions and that downregulation of PvNod22 activated the ER-unfolded protein response (UPR) and cell death. We also established that PvNod22 expression in wild-type bean plants was modulated by abiotic stress but not by chemicals that trigger the UPR, indicating PvNod22 is not under UPR control. Our results suggest that the ability of PvNod22 to suppress protein aggregation contributes to the maintenance of ER homeostasis, thus preventing the induction of cell death via UPR in response to oxidative stress during plant-microbe interactions.

  2. Heat Shock Protein 70 and 90 Genes in the Harmful Dinoflagellate Cochlodinium polykrikoides: Genomic Structures and Transcriptional Responses to Environmental Stresses

    Directory of Open Access Journals (Sweden)

    Ruoyu Guo

    2015-01-01

    Full Text Available The marine dinoflagellate Cochlodinium polykrikoides is responsible for harmful algal blooms in aquatic environments and has spread into the world’s oceans. As a microeukaryote, it seems to have distinct genomic characteristics, like gene structure and regulation. In the present study, we characterized heat shock protein (HSP 70/90 of C. polykrikoides and evaluated their transcriptional responses to environmental stresses. Both HSPs contained the conserved motif patterns, showing the highest homology with those of other dinoflagellates. Genomic analysis showed that the CpHSP70 had no intron but was encoded by tandem arrangement manner with separation of intergenic spacers. However, CpHSP90 had one intron in the coding genomic regions, and no intergenic region was found. Phylogenetic analyses of separate HSPs showed that CpHSP70 was closely related with the dinoflagellate Crypthecodinium cohnii and CpHSP90 with other Gymnodiniales in dinoflagellates. Gene expression analyses showed that both HSP genes were upregulated by the treatments of separate algicides CuSO4 and NaOCl; however, they displayed downregulation pattern with PCB treatment. The transcription of CpHSP90 and CpHSP70 showed similar expression patterns under the same toxicant treatment, suggesting that both genes might have cooperative functions for the toxicant induced gene regulation in the dinoflagellate.

  3. Stroke volume variation does not predict fluid responsiveness in patients with septic shock on pressure support ventilation

    DEFF Research Database (Denmark)

    Perner, A; Faber, T

    2006-01-01

    Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown.......Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown....

  4. The use of a beryllium Hopkinson bar to characterize in-axis and cross-axis accelerometer response in shock environments

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, V.I.; Brown, F.A.

    1997-05-01

    The characteristics of a piezoresistive accelerometer in shock environments are being studied at Sandia National Laboratories in the Mechanical Shock Testing Laboratory. A beryllium Hopkinson bar capability has been developed to extend the understanding of the piezoresistive accelerometer, in two mechanical configurations and with and without mechanical isolation, in the high frequency, high shock environments where measurements are being made. In this paper, recent measurements with beryllium single and split-Hopkinson bar configurations are described. The in axis performance of the piezoresistive accelerometer in mechanical isolation for frequencies of dc-30 kHz and shock magnitudes of up to 6,000 g as determined from measurements with a beryllium Hopkinson bar with a certified laser doppler vibrometer as the reference measurement are presented. Results of characterizations of the accelerometers subjected to cross axis shocks in a split beryllium Hopkinson bar configuration are also presented.

  5. Management of Shock in Neonates.

    Science.gov (United States)

    Bhat, B Vishnu; Plakkal, Nishad

    2015-10-01

    Shock is characterized by inadequate oxygen delivery to the tissues, and is more frequent in very low birth weight infants, especially in the first few days of life. Shock is an independent predictor of mortality, and the survivors are at a higher risk of neurologic impairment. Understanding the pathophysiology helps to recognize and classify shock in the early compensated phase and initiate appropriate treatment. Hypovolemia is rarely the primary cause of shock in neonates. Myocardial dysfunction is especially common in extremely preterm infants, and in term infants with perinatal asphyxia. Blood pressure measurements are easy, but correlate poorly with cerebral and systemic blood flows. Point-of-care cardiac ultrasound can help in individualized assessment of problems, selecting appropriate therapy and monitoring response, but may not always be available, and long-term benefits need to be demonstrated. The use of near-infrared spectroscopy to guide treatment of neonatal shock is currently experimental. In the absence of hypovolemia, excessive administration of fluid boluses is inappropriate therapy. Dobutamine and dopamine are the most common initial inotropes used in neonatal shock. Dobutamine has been shown to improve systemic blood flow, especially in very low birth weight infants, but dopamine is better at improving blood pressure in hypotensive infants. Newer inodilators including milrinone and levosimendan may be useful in selected settings. Data on long-term survival and neurologic outcomes following different management strategies are scarce and future research efforts should focus on this.

  6. Stroke volume variation does not predict fluid responsiveness in patients with septic shock on pressure support ventilation

    DEFF Research Database (Denmark)

    Perner, A; Faber, T

    2006-01-01

    Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown....

  7. Effects of a Single Dose of Parecoxib on Inflammatory Response and Ischemic Tubular Injury Caused by Hemorrhagic Shock in Rats

    Directory of Open Access Journals (Sweden)

    Mariana Takaku

    2018-01-01

    Full Text Available Parecoxib, a selective COX-2 inhibitor, is used to improve analgesia in postoperative procedures. Here we evaluated whether pretreatment with a single dose of parecoxib affects the function, cell injury, and inflammatory response of the kidney of rats subjected to acute hemorrhage. Inflammatory response was determined according to serum and renal tissue cytokine levels (IL-1α, IL-1β, IL-6, IL-10, and TNF-α. Forty-four adult Wistar rats anesthetized with sevoflurane were randomized into four groups: placebo/no hemorrhage (Plc/NH; parecoxib/no hemorrhage (Pcx/NH; placebo/hemorrhage (Plc/H; and parecoxib/hemorrhage (Pcx/H. Pcx groups received a single dose of intravenous parecoxib while Plc groups received a single dose of placebo (isotonic saline. Animals in hemorrhage groups underwent bleeding of 30% of blood volume. Renal function and renal histology were then evaluated. Plc/H showed the highest serum levels of cytokines, suggesting that pretreatment with parecoxib reduced the inflammatory response in rats subjected to hemorrhage. No difference in tissue cytokine levels between groups was observed. Plc/H showed higher percentage of tubular dilation and degeneration, indicating that parecoxib inhibited tubular injury resulting from renal hypoperfusion. Our findings indicate that pretreatment with a single dose of parecoxib reduced the inflammatory response and tubular renal injury without altering renal function in rats undergoing acute hemorrhage.

  8. Expression of heat shock proteins (HSPs) in Aedes aegypti (L) and Aedes albopictus (Skuse) (Diptera: Culicidae) larvae in response to thermal stress.

    Science.gov (United States)

    Sivan, Arun; Shriram, Ananganallur Nagarajan; Muruganandam, Nagarajan; Thamizhmani, Ramanathan

    2017-03-01

    Climatic changes are responsible, to a certain extent for the occurrence and spread of arboviral pathogens world over. Temperature is one of the important abiotic factors influencing the physiological processes of mosquitoes. Several genes of heat shock protein (HSP) families are known to be expressed in mosquitoes, which aid in overcoming stress induced by elevated temperature. In order to understand expression of HSP family genes in the Andaman population of Aedes aegypti and Aedes albopictus, we used quantitative real-time polymerase chain reaction (qPCR) to examine expression levels of HSPs in response to thermal stress under laboratory and in actual field conditions. HSP genes AeaHsp26, AeaHsp83 and AeaHsc70 were examined by comparing relative transcript expression levels at 31°C, 33°C, 34°C, 37°C and 39°C respectively. Enhanced up-regulation of HSPs was evident in third instar larvae of Ae. aegypti with rise in water temperatures (31°C, 33°C, 34°C) in the containers in the nature and thermally stressed (37°C and 39°C) in laboratory conditions. In Ae. albopictus up-regulation of HSPs was observed in field conditions at 34°C only and when thermally treated at 37°C, while down regulation was evident in larvae subjected to thermal stress in laboratory at 39°C. Data on expression levels revealed that larvae of Ae. aegypti was tolerant to thermal stress, while Ae. albopictus larvae was sensitive to heat shock treatment. Statistical analysis indicated that AeaHsp83 genes were significantly up-regulated in Ae. aegypti larvae after 360min exposure to high temperature (39°C). The difference in expression levels of AeaHsp26, AeaHsc70 and AeaHsp83 genes in Ae. albopictus larvae was statistically significant between different exposure temperatures. All of these genes were significantly up-regulated at 37°C. These results indicate that AeaHsp26, AeaHsc70 and AeaHsp83 are important markers of stress and perhaps function as proteins conferring protection and

  9. Collisionless electrostatic shocks

    DEFF Research Database (Denmark)

    Andersen, H.K.; Andersen, S.A.; Jensen, Vagn Orla

    1970-01-01

    An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth......An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth...

  10. Investigation of scour adjacent to submerged geotextiles used for shore protection

    Energy Technology Data Exchange (ETDEWEB)

    Gorton, Alicia M.; Herrington, Thomas O.; Smith, Ernest R.

    2018-01-03

    This study presents the results of an experimental investigation of morphology change in the vicinity of submerged geotextiles placed within the surf zone. The study was motivated by the emerging use of submerged geotextile tubes for shore protection, shoreline stabilization, and surf amenity enhancement and the need to understand the mechanisms responsible for scour in the vicinity of these structures to preserve their structural integrity and reduce their structural failure. A movable bed physical model experiment was conducted at the U.S. Army Engineer Research and Development Center’s Large-scale Sediment Transport Facility (LSTF) to develop empirical formulations to predict the mean scour depth adjacent to geotextiles under oblique wave-breaking conditions as a function of the maximum Keulegan-Carpenter, Shields, and Reynolds numbers. The observed scour in the vicinity of the geotextiles was also compared to a previous study of scour in the vicinity of submerged cylinders. Formulations developed by Cataño-Lopera and García (2006) relating the Keulegan-Carpenter, Shields, and Reynolds numbers to the scour depth were used to predict the scour observed during the LSTF experiment. Results show that the formulations of Cataño-Lopera and García (2006) over-predict the observed scour when calculated using the maximum Keulegan-Carpenter, Shields, and Reynolds numbers. New, modified expressions of Cataño-Lopera and García (2006) were developed for use in oblique random wave fields.

  11. Screening of phytase producers and optimization of culture conditions for submerged fermentation.

    Science.gov (United States)

    Coban, Hasan B; Demirci, Ali

    2014-04-01

    Phytase (myo-inositol-hexakisphosphate phosphohydrolase) is an enzyme, which breaks down phytate to inositol and orthophosphoric acid. Phytase has been used as feed additive, and in some medical applications for years. To date, phytase production has been usually performed as a solid-state fermentation with small production volumes. Therefore, the aim of this study was to increase the phytase activity in submerged fermentations by screening several microorganism strains based on the literature to select the most productive phytase producer and optimizing growth parameters such as temperature, pH, and aeration level using response surface methodology (RSM). As a result, among the four different microorganisms evaluated, Aspergillus ficuum (NRRL 3135) was selected as the most productive strain. Optimum temperature, pH, and aeration values were determined as 33 °C, 4.5, and 0.9 vvm, respectively, for A. ficuum in 2-l batch submerged phytase productions. Under these conditions, phytase activity was measured as 2.27 U/ml. Therefore, this is a unique study showing the production of phytase with A. ficuum successfully in submerged fermentation as opposed to the traditional solid-state fermentation.

  12. Scale resolving computation of submerged wall jets on flat wall with different roughness heights

    Science.gov (United States)

    Paik, Joongcheol; Bombardelli, Fabian

    2014-11-01

    Scale-adaptive simulation is used to investigate the response of velocity and turbulence in submerged wall jets to abrupt changes from smooth to rough beds. The submerged wall jets were experimentally investigated by Dey and Sarkar [JFM, 556, 337, 2006] at the Reynolds number of 17500 the Froude number of 4.09 and the submergence ratio of 1.12 on different rough beds that were generated by uniform sediments of different median diameters The SAS is carried out by means of a second-order-accurate finite volume method in space and time and the effect of bottom roughness is treated by the approach of Cebeci (2004). The evolution of free surface is captured by employing the two-phase volume of fluid (VOF) technique. The numerical results obtained by the SAS approach, incorporated with the VOF and the rough wall treatment, are in good agreement with the experimental measurements. The computed turbulent boundary layer grows more quickly and the depression of the free surface is more increased on the rough wall than those on smooth wall. The size of the fully developed zone shrinks and the decay rate of maximum streamwise velocity and Reynolds stress components are faster with increase in the wall roughness. Supported by NSF and NRF of Korea.

  13. Oral administration of submerged cultivated Grifola frondosa enhances phagocytic activity in normal mice.

    Science.gov (United States)

    Wang, Lisu; Ha, Choi-Lan; Cheng, Tso-Lin; Cheng, Su-Yun; Lian, Tzi-Wei; Wu, Ming-Jiuan

    2008-02-01

    Grifola frondosa fruiting body (Maitake) has been used as a dietary supplement due to its antitumour and immunomodulatory properties. The aim of this study was to evaluate the immunomodulatory effects of orally administered submerged cultivated G. frondosa mixture, including both mycelium and culture broth, in a healthy murine model. Composition analyses showed that submerged cultivated G. frondosa mixture contained only 32.48% carbohydrate, which was less than half of fruiting bodies. The content of adenosine, a potential immunomodulatory agent in medicinal mushrooms, was 2.8 mg g(-1). After feeding 8-week-old female BALB/cByJ mice with AIN-93G diet containing 0% (C), 1% (G1), 3% (G3) or 5% (G5) (wt/wt) G. frondosa mixture for 31 days, neither body weight nor the outward appearance of organs showed any significant difference among different diet groups. Splenocyte subpopulation, mitogen-activated cytokine release and splenic NK activity were not affected by G. frondosa administration, either. On the other hand, the phagocytic activity was enhanced in leucocytes of groups G3 and G5, without exerting detectable levels of serum proinflammatory cytokines. These results suggested that oral administration of submerged cultivated G. frondosa mixture may enhance host innate immunity against foreign pathogens without eliciting adverse inflammatory response.

  14. Development and validation of phytotoxicity tests with emergent and submerged aquatic plants

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, J.S. [Carolina Ecotox, Inc., Durham, NC (United States); Powell, R.L. [Monsanto Co., St. Louis, MO (United States); Nelson, M.K. [National Biological Service, Columbia, MO (United States)

    1995-12-31

    Toxicity testing procedures have recently been developed for assessment of contaminant effects on emergent and submerged aquatic macrophytes commonly found in freshwater wetlands. These tests have potential application in risk assessments for contaminated wetlands as well as for new chemical substances. The objective of this study was to evaluate and modify, if necessary, these methods and to validate them, using two benchmark chemicals, in a contract laboratory setting. Oryza sativa (domestic rice) was used as a surrogate emergent vascular plant, while Ceratophylium demersum (coontail) and Myriophyllum heterophyllum (variable-leaf milfoil) were the representative submerged vascular plants. Subsequent to evaluating culturing techniques and testing conditions, toxicity tests were conducted using boron and metribuzin. The test procedure for the emergent plants involves a two-week pro-exposure period followed by a two-week aqueous exposure. Five types of sediment, including both natural and artificial sediments, were evaluated for use with rice. Fresh weight and chlorophyll a content were the selected test endpoints. The submerged plants were exposed for two weeks, and the response variables evaluated included length, weight (fresh and dry), and root number. The sensitivity of these tests were comparable to the results obtained for the same two chemicals using the green alga, Selenastrum capricornutum, and the duckweed, Lemna gibba, with the exception that rice was less sensitive to metribuzin than the other species.

  15. Development of a flyer design to perform plate impact shock-release-shock experiments on explosives

    Science.gov (United States)

    Finnegan, Simon; Ferguson, James; Millett, Jeremy; Goff, Michael

    2017-06-01

    A flyer design to generate a shock-release-shock loading history within a gas gun target was developed before being used to study the response of an HMX based explosive. The flyer consisted of two flyer plates separated by a vacuum gap. This created a rear free surface that, with correct material choice, allowed the target to release to close to ambient pressure between the initial shock and subsequent re-shock. The design was validated by impacting piezoelectric pin arrays to record the front flyer deformation. Shots were performed on PCTFE targets to record the shock states generated in an inert material prior to subjecting an HMX based explosive to the same loading. The response of the explosive to this loading history was recorded using magnetic particle velocity (PV) gauges embedded within the targets. The behavior during the run to detonation is compared with the response to sustained shocks at similar input pressures.

  16. Basic Shock Physiology and Critical Care.

    Science.gov (United States)

    Roberts, Brian K

    2016-05-01

    Veterinarians practicing emergency medicine and/or working with exotic animals must be well versed in the pathophysiology of shock because many exotic pets present with an acute crisis or an acute manifestation of a chronic process causing poor organ perfusion. This article discusses the pathophysiology of shock and the systemic inflammatory response syndrome, which may lead to organ dysfunction, organ failure, sepsis, and death. The physiology of perfusion, perfusion measurements, categories of shock, and altered function of the immune system, gastrointestinal barrier, and coagulation system are discussed. Veterinarians providing emergency care to patients with shock must also be aware of comorbidities. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Understanding the Heat Shock Response in the Sea Cucumber Apostichopus japonicus, Using iTRAQ-Based Proteomics

    Directory of Open Access Journals (Sweden)

    Dongxue Xu

    2016-02-01

    Full Text Available The sea cucumber Apostichopus japonicus is exploited as a commercial species owing to their high nutritive and medicinal value. Recent high summer temperatures have caused high mortality rates in A. japonicus. In this study, we applied the isobaric tag for relative and absolute quantitation (iTRAQ technique to investigate the global protein expression profile under an acute short-term (48 h heat stress. In total, 3432 proteins were identified, and 127 proteins showed significant heat stress responses, with 61 upregulated proteins and 66 downregulated proteins. Our results suggest that heat stress influenced the expression of proteins involved in various biological processes, such as tissue protection and detoxification, lipid and amino acid metabolism, energy production and usage, transcription and translation, cell apoptosis, and cell proliferation. These findings provide a better understanding about the response and thermo-tolerance mechanisms of A. japonicus under heat stress.

  18. Shock heating of the solar wind plasma

    Science.gov (United States)

    Whang, Y. C.; Liu, Shaoliang; Burlaga, L. F.

    1990-01-01

    The role played by shocks in heating solar-wind plasma is investigated using data on 413 shocks which were identified from the plasma and magnetic-field data collected between 1973 and 1982 by Pioneer and Voyager spacecraft. It is found that the average shock strength increased with the heliocentric distance outside 1 AU, reaching a maximum near 5 AU, after which the shock strength decreased with the distance; the entropy of the solar wind protons also reached a maximum at 5 AU. An MHD simulation model in which shock heating is the only heating mechanism available was used to calculate the entropy changes for the November 1977 event. The calculated entropy agreed well with the value calculated from observational data, suggesting that shocks are chiefly responsible for heating solar wind plasma between 1 and 15 AU.

  19. Immunomodulatory properties of Grifola frondosa in submerged culture.

    Science.gov (United States)

    Wu, Ming-Jiuan; Cheng, Tso-Lin; Cheng, Su-Yun; Lian, Tzi-Wei; Wang, Lisu; Chiou, Shu-Yuan

    2006-04-19

    Maitake (Grifola frondosa) is a popular mushroom in Asia for its tasty flavor and immune-stimulating property. The aim of the study is to investigate the innate immunity augmentation effects of different extracts of mycelia and culture filtrate from G. frondosa in submerged cultures. The hot water extract of mycelia showed the strongest cytokine induction effect as a function of its concentration in human whole blood culture. The most potent fractions of hot water extract, Fr. I and II, were mainly composed of polysaccharides with molecular masses of 43-140 and 13-38 kDa, respectively. These fractions (0.025 mg/mL) showed marked activity in enhancing phagocytosis of human polymorphonuclear neutrophils (PMN). In parallel, the expression of CD11b, an early marker of PMN activation, was also up-regulated dose dependently. This result suggested that complement receptor 3 was primed by these fractions. In addition to activation of phagocytes, these bioactive fractions also increased human peripheral blood natural killer cell cytotoxicity. These results imply that the relatively low molecular mass polysaccharides isolated from mycelia of G. frondosa can enhance innate immunity in vitro and therefore may serve as biological response modifiers.

  20. Anaphylactic shock during hydatid cyst surgery

    Directory of Open Access Journals (Sweden)

    Mustapha Bensghir

    2012-01-01

    Full Text Available Intraoperative anaphylactic shock is an unusual complication. Different causes can be involved. Surgery of hydatid cyst is rarely responsible. About a case report of anaphylactic shock due to hydatid cyst surgery, the authors discuss the mechanisms, principles of treatment, and prevention measures of this complication.

  1. Analysis of the heat shock response in mouse liver reveals transcriptional dependence on the nuclear receptor peroxisome proliferator-activated receptor α (PPARα

    Directory of Open Access Journals (Sweden)

    Jonnalagadda Sudhakar

    2010-01-01

    Full Text Available Abstract Background The nuclear receptor peroxisome proliferator-activated receptor alpha (PPARα regulates responses to chemical or physical stress in part by altering expression of genes involved in proteome maintenance. Many of these genes are also transcriptionally regulated by heat shock (HS through activation by HS factor-1 (HSF1. We hypothesized that there are interactions on a genetic level between PPARα and the HS response mediated by HSF1. Results Wild-type and PPARα-null mice were exposed to HS, the PPARα agonist WY-14,643 (WY, or both; gene and protein expression was examined in the livers of the mice 4 or 24 hrs after HS. Gene expression profiling identified a number of Hsp family members that were altered similarly in both mouse strains. However, most of the targets of HS did not overlap between strains. A subset of genes was shown by microarray and RT-PCR to be regulated by HS in a PPARα-dependent manner. HS also down-regulated a large set of mitochondrial genes specifically in PPARα-null mice that are known targets of PPARγ co-activator-1 (PGC-1 family members. Pretreatment of PPARα-null mice with WY increased expression of PGC-1β and target genes and prevented the down-regulation of the mitochondrial genes by HS. A comparison of HS genes regulated in our dataset with those identified in wild-type and HSF1-null mouse embryonic fibroblasts indicated that although many HS genes are regulated independently of both PPARα and HSF1, a number require both factors for HS responsiveness. Conclusions These findings demonstrate that the PPARα genotype has a dramatic effect on the transcriptional targets of HS and support an expanded role for PPARα in the regulation of proteome maintenance genes after exposure to diverse forms of environmental stress including HS.

  2. Early Treatment in Shock

    Science.gov (United States)

    2010-06-17

    Shock 8 RBC membranes.(5) After cooling, 1.0 ml water and 1.0 ml hexane containing 50 mg/L 1 butylated hydroxytoulene (BHT, an antioxidant, Sigma...LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRC U a. REPORT b. ABSTRACT U U c. THIS PAGE UU 50 19b. TELEPHONE...use of DHEA , but studies in our laboratories have failed to show a useful effect (6). Studies with omega-3 fatty acids have shown promise, but are

  3. Advanced and Exploratory Shock Sensing Mechanisms.

    Energy Technology Data Exchange (ETDEWEB)

    Nelsen, Nicholas H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kolb, James D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kulkarni, Akshay G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorscher, Zachary [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Habing, Clayton D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mathis, Allen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Beller, Zachary J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    Mechanical component response to shock environments must be predictable in order to ensure reliability and safety. Whether the shock input results from accidental drops during transportation to projectile impact scenarios, the system must irreversibly transition into a safe state that is incapable of triggering the component . With this critical need in mind, the 2017 Nuclear Weapons Summer Product Realization Institute (NW SPRINT) program objective sought the design of a passive shock failsafe with emphasis on additively manufactured (AM) components. Team Advanced and Exploratory (A&E) responded to the challenge by designing and delivering multiple passive shock sensing mech anisms that activate within a prescribed mechanical shock threshold. These AM failsafe designs were tuned and validated using analytical and computational techniques including the shock response spectrum (SRS) and finite element analysis (FEA). After rapid prototyping, the devices experienced physical shock tests conducted on Sandia drop tables to experimentally verify performance. Keywords: Additive manufacturing, dynamic system, failsafe, finite element analysis, mechanical shock, NW SPRINT, shock respon se spectrum

  4. Geometrical shock dynamics for magnetohydrodynamic fast shocks

    KAUST Repository

    Mostert, W.

    2016-12-12

    We describe a formulation of two-dimensional geometrical shock dynamics (GSD) suitable for ideal magnetohydrodynamic (MHD) fast shocks under magnetic fields of general strength and orientation. The resulting area–Mach-number–shock-angle relation is then incorporated into a numerical method using pseudospectral differentiation. The MHD-GSD model is verified by comparison with results from nonlinear finite-volume solution of the complete ideal MHD equations applied to a shock implosion flow in the presence of an oblique and spatially varying magnetic field ahead of the shock. Results from application of the MHD-GSD equations to the stability of fast MHD shocks in two dimensions are presented. It is shown that the time to formation of triple points for both perturbed MHD and gas-dynamic shocks increases as (Formula presented.), where (Formula presented.) is a measure of the initial Mach-number perturbation. Symmetry breaking in the MHD case is demonstrated. In cylindrical converging geometry, in the presence of an azimuthal field produced by a line current, the MHD shock behaves in the mean as in Pullin et al. (Phys. Fluids, vol. 26, 2014, 097103), but suffers a greater relative pressure fluctuation along the shock than the gas-dynamic shock. © 2016 Cambridge University Press

  5. Response of heat shock protein genes of the oriental fruit moth under diapause and thermal stress reveals multiple patterns dependent on the nature of stress exposure.

    Science.gov (United States)

    Zhang, Bo; Peng, Yu; Zheng, Jincheng; Liang, Lina; Hoffmann, Ary A; Ma, Chun-Sen

    2016-07-01

    Heat shock protein gene (Hsp) families are thought to be important in thermal adaptation, but their expression patterns under various thermal stresses have still been poorly characterized outside of model systems. We have therefore characterized Hsp genes and their stress responses in the oriental fruit moth (OFM), Grapholita molesta, a widespread global orchard pest, and compared patterns of expression in this species to that of other insects. Genes from four Hsp families showed variable expression levels among tissues and developmental stages. Members of the Hsp40, 70, and 90 families were highly expressed under short exposures to heat and cold. Expression of Hsp40, 70, and Hsc70 family members increased in OFM undergoing diapause, while Hsp90 was downregulated. We found that there was strong sequence conservation of members of large Hsp families (Hsp40, Hsp60, Hsp70, Hsc70) across taxa, but this was not always matched by conservation of expression patterns. When the large Hsps as well as small Hsps from OFM were compared under acute and ramping heat stress, two groups of sHsps expression patterns were apparent, depending on whether expression increased or decreased immediately after stress exposure. These results highlight potential differences in conservation of function as opposed to sequence in this gene family and also point to Hsp genes potentially useful as bioindicators of diapause and thermal stress in OFM.

  6. Toll-like receptor 2-independent host innate immune response against an epidemic strain of Streptococcus suis that causes a toxic shock-like syndrome in humans.

    Directory of Open Access Journals (Sweden)

    Claude Lachance

    Full Text Available Streptococcus suis is an emerging zoonotic agent causing meningitis and septicemia. Outbreaks in humans in China with atypical cases of streptococcal toxic shock-like syndrome have been described to be caused by a clonal epidemic S. suis strain characterized as sequence type (ST 7 by multilocus sequence typing, different from the classical ST1 usually isolated in Europe. Previous in vitro studies showed that Toll-like receptor (TLR 2 plays a major role in S. suis ST1 interactions with host cells. In the present study, the in vivo role of TLR2 in systemic infections caused by S. suis ST1 or ST7 strains using TLR2 deficient (TLR2(-/- mice was evaluated. TLR2-mediated recognition significantly contributes to the acute disease caused by the highly virulent S. suis ST1 strain, since the TLR2(-/- mice remained unaffected when compared to wild type (WT mice. The lack of mortality could not be associated with a lower bacterial burden; however, a significant decrease in the induction of pro-inflammatory mediators, as evaluated by microarray, real-time PCR and protein assays, was observed. On the other hand, TLR2(-/- mice infected with the epidemic ST7 strain presented no significant differences regarding survival and expression of pro-inflammatory mediators when compared to the WT mice. Together, these results show a TLR2-independent host innate immune response to S. suis that depends on the strain.

  7. Submerged cultivation of medicinal mushrooms: bioprocesses and products (review).

    Science.gov (United States)

    Elisashvili, Vladimir

    2012-01-01

    Medicinal mushrooms belonging to higher Basidiomycetes are an immensely rich yet largely untapped resource of useful, easily accessible, natural compounds with various biological activities that may promote human well-being. The medicinal properties are found in various cellular components and secondary metabolites (polysaccharides, proteins and their complexes, phenolic compounds, polyketides, triterpenoids, steroids, alkaloids, nucleotides, etc.), which have been isolated and identified from the fruiting bodies, culture mycelium, and culture broth of mushrooms. Some of these compounds have cholesterol-lowering, anti-diabetic, antioxidant, antitumor, immunomodulating, antimicrobial, and antiviral activities ready for industrial trials and further commercialization, while others are in various stages of development. Recently, the submerged cultivation of medicinal mushrooms has received a great deal of attention as a promising and reproducible alternative for the efficient production of mushroom mycelium and metabolites. Submerged cultivation of mushrooms has significant industrial potential, but its success on a commercial scale depends on increasing product yields and development of novel production systems that address the problems associated with this technique of mushroom cultivation. In spite of many researchers' efforts for the production of bioactive metabolites by mushrooms, the physiological and engineering aspects of submerged cultures are still far from being thoroughly studied. The vast majority of studies have focused on polysaccharide and ganoderic acid production in submerged cultivation of medicinal mushrooms, and very little has been written so far on the antioxidant and hemagglutinating activity of submerged mushroom cultures. The purpose of this review is to provide an update of the present state of the art and future prospects of submerged cultivation of medicinal mushrooms to produce mycelium and bioactive metabolites, and to make a

  8. Predicting effects of cold shock: modeling the decline of a thermal plume

    Energy Technology Data Exchange (ETDEWEB)

    Becker, C.D.; Trent, D.S.; Schneider, M.J.

    1977-10-01

    Predicting direct impact of cold shock on aquatic organisms after termination of power plant thermal discharges requires thermal tests that provide quantitative data on the resistance of acclimated species to lower temperatures. Selected examples from the literature on cold shock resistance of freshwater and marine fishes are illustrated to show predictive use. Abrupt cold shock data may be applied to field situations involving either abrupt or gradual temperature declines but yield conservative estimates under the latter conditions. Gradual cold shock data may be applied where heated plumes gradually dissipate because poikilotherms partially compensate for lowering temperature regimes. A simplified analytical model is presented for estimating thermal declines in terminated plumes originating from offshore, submerged discharges where shear current and boundary effects are minimal. When applied to site-specific conditions, the method provides time-temperature distributions for correlation with cold resistance data and, therefore, aids in assessing cold shock impact on aquatic biota.

  9. Efficacy of transthoracic cardioversion of atrial fibrillation using a biphasic, truncated exponential shock waveform at variable initial shock energies.

    Science.gov (United States)

    Rashba, Eric J; Gold, Michael R; Crawford, Fred A; Leman, Robert B; Peters, Robert W; Shorofsky, Stephen R

    2004-12-15

    Biphasic shocks are more effective than damped sine wave monophasic shocks for transthoracic cardioversion (CV) of atrial fibrillation (AF), but the optimal protocol for CV with biphasic shocks has not been defined. We conducted a prospective, randomized study of 120 consecutive patients with persistent AF to delineate the dose-response curve for CV of AF with a biphasic truncated exponential shock waveform and to identify clinical predictors of shock efficacy. Our data suggest that the initial shock energy for CV with this waveform should be 200 J if the patient weighs /=90 kg.

  10. Shock Safe Nepal: team one

    NARCIS (Netherlands)

    Oosterhof, A.J.; Düzgün, B.C.; Spelt, C.J.; De Stoppelaar, A.O.; Van Wijnbergen, E.C.M.

    2016-01-01

    As a response to the 2015 Nepal earthquakes Shock Safe Nepal was founded to function as platform intended to contribute to the development of knowledge on earthquake safe housing. The project started on initiative of the Consul General of Nepal to The Netherlands Cas de Stoppelaar and the faculty of

  11. Differentially expressed seed aging responsive heat shock protein OsHSP18.2 implicates in seed vigor, longevity and improves germination and seedling establishment under abiotic stress.

    Directory of Open Access Journals (Sweden)

    Harmeet eKaur

    2015-09-01

    Full Text Available Small heat shock proteins (sHSP are a diverse group of proteins and are highly abundant in plant species. Although majority of these sHSPs were shown to express specifically in seed, their potential function in seed physiology remains to be fully explored. Our proteomic analysis revealed that OsHSP18.2, a class II cytosolic HSP is an aging responsive protein as its abundance significantly increased after artificial aging in rice seeds. OsHSP18.2 transcript was found to markedly increase at the late maturation stage being highly abundant in dry seeds and sharply decreased after germination. Our biochemical study clearly demonstrated that OsHSP18.2 forms homooligomeric complex and is dodecameric in nature and functions as a molecular chaperon. OsHSP18.2 displayed chaperone activity as it was effective in preventing thermal inactivation of Citrate Synthase. Further, to analyze the function of this protein in seed physiology, seed specific Arabidopsis overexpression lines for OsHSP18.2 were generated. Our subsequent functional analysis clearly demonstrated that OsHSP18.2 has ability to improve seed vigor and longevity by reducing deleterious ROS accumulation in seeds. In addition, transformed Arabidopsis seeds displayed better performance in germination and cotyledon emergence under adverse conditions as well. Collectively, our work demonstrates that OsHSP18.2 is an aging responsive protein which functions as a molecular chaperon and possibly protect and stabilize the cellular proteins from irreversible damage particularly during maturation drying, desiccation and aging in seeds by restricting ROS accumulation and thereby improves seed vigor, longevity and seedling establishment.

  12. Heat shock transcriptional responses in an MC-Producing Cyanobacterium (Planktothrix agardhii) and its MC-deficient mutant under high light conditions.

    Science.gov (United States)

    Tran, Thi Du Chi; Bernard, Cecile; Ammar, Myriam; Chaouch, Soraya; Comte, Katia

    2013-01-01

    Microcystins (MCs) are the most commonly-reported hepatotoxins produced by various cyanobacterial taxa in fresh waters to constitute a potential threat to human and animal health. The biological role of MCs in the producer organisms is not known, and it would be very useful to understand the driving force behind the toxin production. Recent studies have suggested that MCs may have a protective function in cells facing environmental stress. Following this starting premise, we speculate that under adverse conditions the expression of stress-related genes coding for Heat Shock Proteins (Hsp) might be different in an MC-producing strain and its MC-deficient mutant. We therefore used RT-qPCR to compare the expression of 13 hsp genes of an MC-producing strain of Planktothrix agardhii (CYA126/8) and its MC-deficient ΔmcyD mutant over different periods of exposure to high light stress (HL). Three reference genes (RGs) were selected from six candidates to normalize the RT-qPCR data. Of these three RGs (rsh, rpoD, and gltA), gltA is used here for the first time as an RG in prokaryotes. Under HL stress, five genes were found to be strongly up-regulated in both strains (htpG, dnaK, hspA, groES, and groEL). Unexpectedly, we found that the MC-producing wild type strain accumulated higher levels of htpG and dnaK transcripts in response to HL stress than the MC-deficient mutant. In addition, a significant increase in the mcyE transcript was detected in the mutant, suggesting that MCs are required under HL conditions. We discuss several possible roles of MCs in the response to HL stress through their possible involvement in the protective mechanisms of the cells.

  13. Cardiogenic shock: management of right ventricular infarction shock.

    Science.gov (United States)

    Ruiz Bailén, M; Ruiz García, M I; Ferrezuelo Mata, A; Quirós Barrera, R

    2012-04-01

    Right ventricular infarction is a not uncommon cause of cardiogenic shock, whose frecuency is variable and could be underestimated. Although left ventricular myocardial management is well defined in the right ventricular infarction are few studies with low level of evidence, to establish definitive guidelines. It is assumed that the treatment is similar to that of the left ventricle, although there are some differences. The axis of the therapeutic management, as well as the left ventricle infarction, is based on early myocardial reperfusion, particularly through percutaneous coronary interventionism. Throm-bolysis is an option, especially after an increase in systemic blood pressure using vasoactive drugs such as norepinephrine. The preload optimization by volume administration during resuscitation of shock is useful, but it must be with caution. The use of levosimendan could be potentially beneficial option. On the neurohormonal modulation of systemic inflammatory response produced after the cardiogenic shock (CS), the use of ACE inhibitors and beta-blockers is controversial.

  14. Sepsis and Septic Shock Strategies.

    Science.gov (United States)

    Armstrong, Bracken A; Betzold, Richard D; May, Addison K

    2017-12-01

    Three therapeutic principles most substantially improve organ dysfunction and survival in sepsis: early, appropriate antimicrobial therapy; restoration of adequate cellular perfusion; timely source control. The new definitions of sepsis and septic shock reflect the inadequate sensitivity, specify, and lack of prognostication of systemic inflammatory response syndrome criteria. Sequential (sepsis-related) organ failure assessment more effectively prognosticates in sepsis and critical illness. Inadequate cellular perfusion accelerates injury and reestablishing perfusion limits injury. Multiple organ systems are affected by sepsis and septic shock and an evidence-based multipronged approach to systems-based therapy in critical illness results in improve outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Curcumin treatment enhances islet recovery by induction of heat shock response proteins, Hsp70 and heme oxygenase-1, during cryopreservation.

    Science.gov (United States)

    Kanitkar, Meghana; Bhonde, Ramesh R

    2008-01-16

    Limited recovery of islets post-cryopreservation influences graft survival and transplantation efficiency during diabetes treatment. As curcumin, a potent antioxidant/radical scavenging compound, protects islets against beta cell toxins, we hypothesized that inclusion of curcumin during cryopreservation or during post-thaw culture or both may rescue islets from cryoinjury. To test the effect of curcumin inclusion on islet recovery murine islets were isolated by the collagenase digestion, cultured for 48 h, cryopreserved using dimethylsulphoxide as cryoprotectant -- with or without curcumin (10 microM) -- and then slow cooled to -40 degrees C before immersing them in liquid nitrogen for 7 days. Following rapid thawing with sucrose gradient and 24 h post-thaw culture -- in presence or absence of curcumin (10 microM) -- islet viability and functionality were determined. Islet recovery in curcumin treated groups was significantly higher than in groups where islets were cryopreserved without curcumin. Islets cryopreserved with curcumin also showed more intact islets as well as better morphology as compared to islets cryopreserved without curcumin. Curcumin treated islets also showed significant inhibition of ROS generation as compared to islets cryopreserved without curcumin. Glucose responsiveness and insulin secretion in islets cryopreserved with curcumin was equal to that of the freshly isolated islets as against islets cryopreserved without curcumin. Elevated level of Hsp 70 and HO-1 were observed in islets cryopreserved with curcumin and may contribute to curcumin-induced islet rescue. Hence, we conclude that inclusion of curcumin into cryopreservation medium inhibits ROS generation and corresponding islet damage and dysfunction.

  16. Shock compression of simulated adobe

    Science.gov (United States)

    Braithwaite, C. H.; Church, P. D.; Gould, P. J.; Stewart, B.; Jardine, A. P.

    2017-01-01

    A series of plate impact experiments were conducted to investigate the shock response of a simulant for adobe, a traditional form of building material widely used around the world. Air dried bricks were sourced from the London brick company, dry machined and impacted at a range of velocities in a single stage gas gun. The shock Hugoniot was determined (Us =2.26up+0.37) as well as release information. The material was found to behave in a manner which was similar to that of loose sand and considerably less stiff than a weak porous sandstone. The effect of any cementing of the grains was examined by shocking powdered samples contained within a cell arrangement.

  17. Shock compression of liquid hydrazine

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, B.O. [Los Alamos National Lab., NM (United States); Chavez, D.J. [Rockwell White Sands Test Facility, Las Cruces, NM (United States)

    1995-01-01

    Liquid hydrazine (N{sub 2}H{sub 4}) is a propellant used by the Air Force and NASA for aerospace propulsion and power systems. Because the propellant modules that contain the hydrazine can be subject to debris impacts during their use, the shock states that can occur in the hydrazine need to be characterized to safely predict its response. Several shock compression experiments have been conducted in an attempt to investigate the detonability of liquid hydrazine; however, the experiments results disagree. Therefore, in this study, we reproduced each experiment numerically to evaluate in detail the shock wave profiles generated in the liquid hydrazine. This paper presents the results of each numerical simulation and compares the results to those obtained in experiment. We also present the methodology of our approach, which includes chemical kinetic experiments, chemical equilibrium calculations, and characterization of the equation of state of liquid hydrazine.

  18. Comparison of GC-MS and NMR for metabolite profiling of rice subjected to submergence stress.

    Science.gov (United States)

    Barding, Gregory A; Béni, Szabolcs; Fukao, Takeshi; Bailey-Serres, Julia; Larive, Cynthia K

    2013-02-01

    Natural disasters such as drought, extreme temperatures, and flooding can severely impact crop production. Understanding the metabolic response of crops threatened with these disasters provides insights into biological response mechanisms that can influence survival. In this study, a comparative analysis of GC-MS and (1)H NMR results was conducted for wild-type and tolerant rice varieties stressed by up to 3 days of submergence and allowed 1 day of postsubmergence recovery. Most metabolomics studies are conducted using a single analytical platform. Each platform, however, has inherent advantages and disadvantages that can influence the analytical coverage of the metabolome. In this work, a more thorough analysis of the plant stress response was possible through the use of both (1)H NMR and GC-MS. Several metabolites, such as S-methyl methionine and the dipeptide alanylglycine, were only detected and quantified by (1)H NMR. The high dynamic range of NMR, as compared with that of the GC-TOF-MS used in this study, provided broad coverage of the metabolome in a single experiment. The sensitivity of GC-MS facilitated the quantitation of sugars, organic acids, and amino acids, some of which were not detected by NMR, and provided additional insights into the regulation of the TCA cycle. The combined metabolic information provided by (1)H NMR and GC-MS was essential for understanding the complex biochemical and molecular response of rice plants to submergence.

  19. Interactions between piscivores, zooplanktivores and zooplankton in submerged macrophytes : Preliminary observations from enclosure and pond experiments

    DEFF Research Database (Denmark)

    Jacobsen, Lene; Perrow, M.R.; Landkildehus, F.

    1997-01-01

    behavioural changes of zooplanktivores has received little attention, even though this may be an important mechanism in enhancing the stability of submerged macrophytes in shallow lakes. Preliminary observations from an unreplicated large-scale field enclosure experiment and a replicated pond experiment...... and the presence of zooplanktivores typically changed the habitat selection of cladoceran zooplankton. In the case of piscivore/zooplanktivore interactions, the risk of predation was enough to generate clear responses even where the losses to predation were low. However, only in the enclosure experiment...

  20. Wave power absorption by a submerged balloon fixed to the sea bed

    DEFF Research Database (Denmark)

    Kurniawan, Adi; Greaves, Deborah

    2016-01-01

    The possibility of absorbing wave energy using a submerged balloon fixed to the sea bed is investigated. The balloon is in the form of a fabric encased within an array of meridional tendons which terminate at a point at the top of the balloon and at some radius at the bottom. The expansion...... and contraction of the balloon in waves pump air via a turbine into and out of a chamber of constant volume. A more refined model than that used by Kurniawan and Greaves [Proc. 2nd Offshore Energy and Storage Symposium , 2015] predicts a similarly broad-banded response, but the maximum absorption is less than...

  1. Stress response and tolerance of Zea mays to CeO2 nanoparticles: cross talk among H2O2, heat shock protein, and lipid peroxidation.

    Science.gov (United States)

    Zhao, Lijuan; Peng, Bo; Hernandez-Viezcas, Jose A; Rico, Cyren; Sun, Youping; Peralta-Videa, Jose R; Tang, Xiaolei; Niu, Genhua; Jin, Lixin; Varela-Ramirez, Armando; Zhang, Jian-ying; Gardea-Torresdey, Jorge L

    2012-11-27

    The rapid development of nanotechnology will inevitably release nanoparticles (NPs) into the environment with unidentified consequences. In addition, the potential toxicity of CeO(2) NPs to plants and the possible transfer into the food chain are still unknown. Corn plants (Zea mays) were germinated and grown in soil treated with CeO(2) NPs at 400 or 800 mg/kg. Stress-related parameters, such as H(2)O(2), catalase (CAT), and ascorbate peroxidase (APX) activity, heat shock protein 70 (HSP70), lipid peroxidation, cell death, and leaf gas exchange were analyzed at 10, 15, and 20 days post-germination. Confocal laser scanning microscopy was used to image H(2)O(2) distribution in corn leaves. Results showed that the CeO(2) NP treatments increased accumulation of H(2)O(2), up to day 15, in phloem, xylem, bundle sheath cells and epidermal cells of shoots. The CAT and APX activities were also increased in the corn shoot, concomitant with the H(2)O(2) levels. Both 400 and 800 mg/kg CeO(2) NPs triggered the up-regulation of the HSP70 in roots, indicating a systemic stress response. None of the CeO(2) NPs increased the level of thiobarbituric acid reacting substances, indicating that no lipid peroxidation occurred. CeO(2) NPs, at both concentrations, did not induce ion leakage in either roots or shoots, suggesting that membrane integrity was not compromised. Leaf net photosynthetic rate, transpiration, and stomatal conductance were not affected by CeO(2) NPs. Our results suggest that the CAT, APX, and HSP70 might help the plants defend against CeO(2) NP-induced oxidative injury and survive NP exposure.

  2. Cardiosphere Derived Cells from Pediatric End-Stage Heart Failure Patients Have Enhanced Functional Activity due to the Heat Shock Response Regulating the Secretome

    Science.gov (United States)

    Sharma, Sudhish; Mishra, Rachana; Simpson, David; Wehman, Brody; Colletti, Evan J.; Deshmukh, Savitha; Datla, Srinivasa Raju; Balachandran, Keerti; Guo, Yin; Chen, Ling; Siddiqui, Osama T.; Kaushal, Shalesh; Kaushal, Sunjay

    2016-01-01

    We have demonstrated that human neonatal cardiosphere derived cells (CDCs) derived from the young are more regenerative due to their robust secretome. However, it is unclear how the decompensated pediatric heart impacts the functional activity of their CDCs. Our aim was to characterize the potency of pediatric CDCs derived from normal functioning myocardium of control heart disease (CHD) patients to those generated from age matched end stage heart failure (ESHF) patients and determine the mechanisms involved. ESHF derived CDCs contained a higher number of c-kit+, Islet-1+, and Sca-1+ cells. When transplanted into an infarcted rodent model, ESHF derived CDCs significantly demonstrated higher restoration of ventricular function, prevented adverse remodeling, and enhanced angiogenesis when compared to CHD patients. The superior functional recovery of the ESHF derived CDCs was mediated in part by increased SDF-1α and VEGF-A secretion resulting in augmented recruitment of endogenous stem cells and proliferation of cardiomyocytes. We determined the mechanism is due to the secretome directed by the heat shock response (HSR), which is supported by three lines of evidence. Firstly, gain of function studies demonstrated that increased HSR induced the lower functioning CHD derived CDCs to significantly restore myocardial function. Secondly, loss-of function studies targeting the HSR impaired the ability of the ESHF derived CDCs to functionally recover the injured myocardium. Finally, the native ESHF myocardium had an increased number of c-kit+ CSCs. These findings suggest that the HSR enhances the functional activity of ESHF derived CDCs by increasing their secretome activity, notably SDF-1α and VEGF-A. PMID:25752510

  3. Chronic fatigue syndrome: acute infection and history of physical activity affect resting levels and response to exercise of plasma oxidant/antioxidant status and heat shock proteins.

    Science.gov (United States)

    Jammes, Y; Steinberg, J G; Delliaux, S

    2012-07-01

    A history of high-level physical activity and/or acute infection might constitute stress factors affecting the plasma oxidant-antioxidant status and levels of heat shock proteins (HSPs) in patients with chronic fatigue syndrome (CFS). This case-control study compared data from 43 CFS patients to results from a matched control group of 23 healthy sedentary subjects. Five patients had no relevant previous history (group I). Eighteen had practised high-level sport (group II), and severe acute infection had been diagnosed in nine patients (group III). A combination of sport practice and infection was noted in 11 patients (group IV). After examination at rest, all subjects performed a maximal cycling exercise test. Plasma levels of two markers of oxidative stress [thiobarbituric acid reactive substances (TBARS) and reduced ascorbic acid (RAA)] and both HSP27 and HSP70 were measured. At rest, compared with the control group, the TBARS level was higher in groups II, III and IV patients, and the RAA level was lower in groups III and IV. In addition, HSP70 levels were significantly lower in all CFS groups, compared with controls, but negative correlations were found between resting HSP27 and HSP70 levels and the history of physical activity. After exercise, the peak level of TBARS significantly increased in groups II, III and IV, and the variations in HSP27 and HSP70 were attenuated or suppressed, with the greatest effects in groups III and IV. The presence of stress factors in the history of CFS patients is associated with severe oxidative stress and the suppression of protective HSP27 and HSP70 responses to exercise. © 2011 The Association for the Publication of the Journal of Internal Medicine.

  4. Diverging oxidative damage and heat shock protein 72 responses to endurance training and chronic testosterone propionate treatment in three striated muscle types of adolescent male rats.

    Science.gov (United States)

    Sadowska-Krepa, E; Klapcinska, B; Jagsz, S; Chalimoniuk, M; Chrapusta, S J; Wanke, A; Grieb, P; Langfort, J

    2013-10-01

    The aim of the study was to assess the effects of a combination of anabolic-androgenic steroid abuse and endurance training during adolescence on selected aspects of oxidative stress and antioxidant defenses in various striated muscle types. The effects were studied of testosterone propionate (TP) treatment (8 and 80 mg/kg/week, for 6 weeks), given alone or in combination with moderate-intensity endurance training, starting at adolescence, on thiobarbituric acid-reactive substances and heat shock protein 72 (Hsp72) contents, and androgen receptorm(AR) mRNA level in the heart left ventricle, soleus and extensor digitorum longus of male Wistar rats. TP treatment alone markedly elevated thiobarbituric acid-reactive substances only in the left ventricle and soleus; this effect was but marginally enhanced by endurance training. The training alone markedly elevated Hsp72 content in all muscles studied. TP treatment alone dose-dependently upregulated Hsp72, while the lower TP dose slightly curtailed the effect of the training. Low-dose TP treatment alone elevated, whereas high-dose TP treatment alone lowered androgen receptor mRNA level in the soleus and extensor digitorum longus. Endurance training alone elevated AR mRNA in all muscles studied, whereas TP treatment dose-dependently counteracted this effect. Exercise-associated rise in body temperature was significantly less in the TP-treated rats. We came to the conclusion that chronic suprapharmacological TP treatment might exert a protective effect on muscle cell proteins in adolescent sedentary rats, but it markedly enhanced lipid peroxidation. These effects were unlikely to result from an androgen receptor-mediated genomic action of testosterone. Exercise-related heat stress, and not oxidative stress, was mainly responsible for Hsp72 upregulation in striated muscles of chronic TP-treated endurance-trained adolescent male rats.

  5. Peculiarities of thermal dissociation of oxides during submerged arc welding

    Directory of Open Access Journals (Sweden)

    Leonid Zhdanov

    2013-12-01

    Full Text Available A method of settlement of the process of thermal dissociation of oxides in reaction zone during the submerged arc welding and welding deposition is presented. Combined non-linear equations for definition of gas-vapour mixture composition were developed. They describe the dissociation of MeO, MeO2 and Me2O3 types of oxides. Calculations of the processes of oxide dissociation were performed for the oxides that are commonly included into welding fluxes. Their results and analysis are presented. The method proposed appeared to be adequate and applicable for analysis of processes during submerged arc operation that run in the gas phase.

  6. EAARL-B Submerged Topography—Saint Croix, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A submerged topography digital elevation model (DEM) mosaic for a portion of the submerged environs of Saint Croix, U.S. Virgin Islands, was produced from remotely...

  7. EAARL-B Submerged Topography--Saint Thomas, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A submerged topography Digital Elevation Model (DEM) mosaic for a portion of the submerged environs of Saint Thomas, U.S. Virgin Islands, was produced from remotely...

  8. Long-term allelopathic control of phytoplankton by the submerged macrophyte Elodea nuttallii

    NARCIS (Netherlands)

    Vanderstukken, M.; Declerck, S.A.J.; Decaestecker, E.; Muylaert, K.

    2014-01-01

    Keywords: allelochemicals; chemical ecology; competition; nutrient limitation; shallow lakes Summary 1.It is well known that submerged macrophytes can suppress phytoplankton blooms in lakes and thus promote water quality and biodiversity. One of the possible mechanisms through which submerged

  9. Invasive Crayfish Threaten the Development of Submerged Macrophytes in Lake Restoration

    NARCIS (Netherlands)

    Wal, van der J.E.M.; Dorenbosch, M.; Immers, A.K.; Vidal Forteza, C.; Geurts Van Kessel, J.M.M.; Peeters, E.T.H.M.; Koese, B.; Bakker, E.S.

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous

  10. Invasive crayfish threaten the development of submerged macrophytes in lake restoration

    NARCIS (Netherlands)

    Van der Wal, J.E.M.; Dorenbosch, M.; Immers, A.; Vidal Forteza, C.; Geurts, J.J.M.; Peeters, E.T.H.M.; Koese, B.; Bakker, E.S.

    2013-01-01

    Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous

  11. Biomass shock pretreatment

    Science.gov (United States)

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  12. Through-flow of water in leaves of a submerged plant is influenced by the apical opening

    DEFF Research Database (Denmark)

    Pedersen, Ole; Jørgensen, Lise Bolt; Sand-Jensen, Kaj

    1997-01-01

    Submerged plant, apical opening, hydathode, Sparganium, hydraulic architecture, leaf specific conductivity......Submerged plant, apical opening, hydathode, Sparganium, hydraulic architecture, leaf specific conductivity...

  13. The Use of a Beryllium Hopkinson Bar to Characterize In-Axis and Cross-Axis Accelerometer Response in Shock Environments

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, V.I.; Brown, F.A.

    1999-01-01

    The characteristics of a piezoresistive accelerometer in shock environments have been studied at Sandia National Laboratories in the Mechanical Shock Laboratory. A beryllium Hopkinson bar capability with diameters of 0.75 in. and 2.0 in has been developed to extend our understanding of the piezoresistive accelerometer, in two mechanical configurations, in the high frequency, high shock environments where measurements are being made. The in-axis performance of the piezoresistive accelerometer determined from measurements with a beryllium Hopkinson bar and a certified laser doppler vibrometer as the reference measurement is presented. The cross-axis performance of the accelerometer subjected to static compression on a beryllium cylinder, static strain on a steel beam, dynamic strain on a steel beam (ISA-RP 37.2, Paragraph 6.6), and compressive shocks in a split beryllium Hopkinson bar configuration is also presented. The performance of the accelerometer in a combined in-axis and cross-axis shock environment is shown for one configuration. Finally, a failure analysis conducted in cooperation with ENDEVCO gives a cause for the occasional unexplained failures that have occurred in some applications.

  14. Characterization of Shocked Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Cady, Carl M [Los Alamos National Laboratory; Adams, Chris D [Los Alamos National Laboratory; Hull, Lawrence M [Los Alamos National Laboratory; Gray III, George T [Los Alamos National Laboratory; Prime, Michael B [Los Alamos National Laboratory; Addessio, Francis L [Los Alamos National Laboratory; Wynn, Thomas A [Los Alamos National Laboratory; Brown, Eric N [Los Alamos National Laboratory

    2012-08-24

    Beryllium metal has many excellent structural properties in addition to its unique radiation characteristics, including: high elastic modulus, low Poisson's ratio, low density, and high melting point. However, it suffers from several major mechanical drawbacks: 1) high anisotropy - due to its hexagonal lattice structure and its susceptibility to crystallographic texturing; 2) susceptibility to impurity-induced fracture - due to grain boundary segregation; and 3) low intrinsic ductility at ambient temperatures thereby limiting fabricability. While large ductility results from deformation under the conditions of compression, the material can exhibit a brittle behavior under tension. Furthermore, there is a brittle to ductile transition at approximately 200 C under tensile conditions. While numerous studies have investigated the low-strain-rate constitutive response of beryllium, the combined influence of high strain rate and temperature on the mechanical behavior and microstructure of beryllium has received limited attention over the last 40 years. Prior studies have focused on tensile loading behavior, or limited conditions of dynamic strain rate and/or temperature. The beryllium used in this study was Grade S200-F (Brush Wellman, Inc., Elmore, OH) material. The work focused on high strain rate deformation and examine the validity of constitutive models in deformation rate regimes, including shock, the experiments were modeled using a Lagrangian hydrocode. Two constitutive strength (plasticity) models, the Preston-Tonks-Wallace (PTW) and Mechanical Threshold Stress (MTS) models, were calibrated using the same set of quasi-static and Hopkinson bar data taken at temperatures from 77K to 873K and strain rates from 0.001/sec to 4300/sec. In spite of being calibrated on the same data, the two models give noticeably different results when compared with the measured wave profiles. These high strain rate tests were conducted using both explosive drive and a gas gun to

  15. Hydrogen mitigation in submerged arc welding

    Science.gov (United States)

    Klimowicz, Steven

    With the role of hydrogen in weld metal well understood in its relation to cold cracking, there has been a push to produce welds with lower and lower diffusible hydrogen contents. The push for lower diffusible hydrogen contents has placed pressure on consumables manufactures to create consumables that can achieve the requirements for lower diffusible hydrogen content. Currently EM12K flux is produced so that it can achieve below 4 ml of diffusible hydrogen for every 100g of weld metal deposited (ml/100g) for submerged arc welding (SAW). The recent trend for industry is to preferentially achieve diffusible hydrogen contents below 3 ml/100g. Making it necessary to find a way to modify the flux to achieve a lower diffusible hydrogen content for the welds it produces. To achieve this goal a two phase plan was developed. The first phase was to characterize the entire welding system for hydrogen. Since the goal of the project is hydrogen mitigation, any amount of hydrogen that could be reduced is helpful and therefore must first be discovered. Sources of hydrogen may be found by analyzing the welding wire and base metal, as well as breaking the flux down into its components and production steps. The wire was analyzed for total hydrogen content as was the base metal. The flux and its components were analyzed using differential thermal analysis-simultaneous thermal analysis (DTA-STA) and later vacuum degassing for moisture content. The analysis of the wire showed that the copper coating on the wire was the largest contributor of hydrogen. There was lubricant present on the wire surface as well, but it did not contribute as much as the copper coating. It was found that a simple low temperature baking of the wire was enough to remove the lubricant and coating moisture. The base metal was found to have a similar total hydrogen content to that of the wire. The breakdown of the flux and production process for moisture content analysis revealed that the production process

  16. Shock wave compression of condensed matter a primer

    CERN Document Server

    Forbes, Jerry W

    2012-01-01

    This book introduces the core concepts of the shock wave physics of condensed matter, taking a continuum mechanics approach to examine liquids and isotropic solids. The text primarily focuses on one-dimensional uniaxial compression in order to show the key features of condensed matter’s response to shock wave loading. The first four chapters are specifically designed to quickly familiarize physical scientists and engineers with how shock waves interact with other shock waves or material boundaries, as well as to allow readers to better understand shock wave literature, use basic data analysis techniques, and design simple 1-D shock wave experiments. This is achieved by first presenting the steady one-dimensional strain conservation laws using shock wave impedance matching, which insures conservation of mass, momentum and energy. Here, the initial emphasis is on the meaning of shock wave and mass velocities in a laboratory coordinate system. An overview of basic experimental techniques for measuring pressure...

  17. Collisionless Weibel shocks: Full formation mechanism and timing

    Energy Technology Data Exchange (ETDEWEB)

    Bret, A. [ETSI Industriales, Universidad de Castilla-La Mancha, 13071 Ciudad Real (Spain); Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Campus Universitario de Ciudad Real, 13071 Ciudad Real (Spain); Stockem, A. [GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon (Portugal); Institut für Theoretische Physik, Lehrstuhl IV: Weltraum- und Astrophysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Narayan, R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51 Cambridge, Massachusetts 02138 (United States); Silva, L. O. [GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Lisbon (Portugal)

    2014-07-15

    Collisionless shocks in plasmas play an important role in space physics (Earth's bow shock) and astrophysics (supernova remnants, relativistic jets, gamma-ray bursts, high energy cosmic rays). While the formation of a fluid shock through the steepening of a large amplitude sound wave has been understood for long, there is currently no detailed picture of the mechanism responsible for the formation of a collisionless shock. We unravel the physical mechanism at work and show that an electromagnetic Weibel shock always forms when two relativistic collisionless, initially unmagnetized, plasma shells encounter. The predicted shock formation time is in good agreement with 2D and 3D particle-in-cell simulations of counterstreaming pair plasmas. By predicting the shock formation time, experimental setups aiming at producing such shocks can be optimised to favourable conditions.

  18. Increasing heat storage by wearing extra clothing during upper body exercise up-regulates heat shock protein 70 but does not modify the cytokine response.

    Science.gov (United States)

    Leicht, Christof A; Papanagopoulos, Aris; Haghighat, Sam; Faulkner, Steve H

    2017-09-01

    Plasma heat shock protein 70 (HSP70) concentrations rise during heat stress, which can independently induce cytokine production. Upper body exercise normally results in modest body temperature elevations. The aim of this study was to investigate the impacts of additional clothing on the body temperature, cytokine and HSP70 responses during this exercise modality. Thirteen males performed 45-min constant-load arm cranking at 63% maximum aerobic power (62 ± 7%V̇O2peak) in either a non-permeable whole-body suit (intervention, INT) or shorts and T-shirt (control, CON). Exercise resulted in a significant increase of IL-6 and IL-1ra plasma concentrations (P  0.19). The increase in HSP70 from pre to post was only significant for INT (0.12 ± 0.11ng∙mL-1, P < 0.01 vs. 0.04 ± 0.18 ng∙mL-1, P = 0.77). Immediately following exercise, Tcore was elevated by 0.46 ± 0.29 (INT) and 0.37 ± 0.23ºC (CON), respectively (P < 0.01), with no difference between conditions (P = 0.16). The rise in mean Tskin (2.88 ± 0.50 and 0.30 ± 0.89ºC, respectively) and maximum heat storage (3.24 ± 1.08 and 1.20 ± 1.04 J∙g-1, respectively) was higher during INT (P < 0.01). Despite large differences in heat storage between conditions, the HSP70 elevations during INT, even though significant, were very modest. Possibly, the Tcore elevations were too low to induce a more pronounced HSP70 response to ultimately affect cytokine production.

  19. Brain tumor magnetic targeting and biodistribution of superparamagnetic iron oxide nanoparticles linked with 70-kDa heat shock protein study by nonlinear longitudinal response

    Energy Technology Data Exchange (ETDEWEB)

    Shevtsov, Maxim A., E-mail: shevtsov-max@mail.ru [Institute of Cytology of the Russian Academy of Sciences (RAS), Tikhoretsky Ave. 4, St. Petersburg 194064 (Russian Federation); A.L. Polenov Russian Research Scientific Institute of Neurosurgery, Mayakovsky str. 12, St. Petersburg 191014 (Russian Federation); Nikolaev, Boris P. [Research Institute of Highly Pure Biopreparations, Pudozhskaya str. 12, St. Petersburg 197110 (Russian Federation); Ryzhov, Vyacheslav A. [Petersburg Nuclear Physics Institute, NRC Kurchatov Institute, Gatchina 188300 (Russian Federation); Yakovleva, Ludmila Y. [Research Institute of Highly Pure Biopreparations, Pudozhskaya str. 12, St. Petersburg 197110 (Russian Federation); Dobrodumov, Anatolii V. [Institute of Macromolecular Compounds of the Russian Academy of Sciences (RAS), Bolshoi pr. 31, St. Petersburg 199004 (Russian Federation); Marchenko, Yaroslav Y. [Research Institute of Highly Pure Biopreparations, Pudozhskaya str. 12, St. Petersburg 197110 (Russian Federation); Margulis, Boris A. [Institute of Cytology of the Russian Academy of Sciences (RAS), Tikhoretsky Ave. 4, St. Petersburg 194064 (Russian Federation); Pitkin, Emil [The Wharton School, University of Pennsylvania, 3730 Walnut St., Philadelphia, PA 19104 (United States); Guzhova, Irina V. [Institute of Cytology of the Russian Academy of Sciences (RAS), Tikhoretsky Ave. 4, St. Petersburg 194064 (Russian Federation)

    2015-08-15

    Brain tumor targeting efficiency and biodistribution of the superparamagnetic nanoparticles conjugated with heat shock protein Hsp70 (SPION–Hsp70) were evaluated in experimental glioma model. Synthesized conjugates were characterized using the method of longitudinal nonlinear response of magnetic nanoparticles to a weak ac magnetic field with measurements of second harmonic of magnetization (NLR-M{sub 2}). Cellular interaction of magnetic conjugates was analyzed in 9L glioma cell culture. The biodistribution of the nanoparticles and their accumulation in tumors was assessed by the latter approach as well. The efficacy of Hsp70-conjugates for contrast enhancement in the orthotopic model of 9L glioma was assessed by MR imaging (11 T). Magnetic nanoparticles conjugated with Hsp70 had the relaxivity properties of the MR-negative contrast agents. Morphological observation and cell viability test demonstrated good biocompatibility of Hsp70-conjugates. Analysis of the T{sub 2}-weighted MR scans in tumor-bearing rats demonstrated the high efficacy of Hsp70-conjugates in contrast enhancement of the glioma in comparison to non-conjugated nanoparticles. High contrast enhancement of the glioma was provided by the accumulation of the SPION–Hsp70 particles in the glioma tissue (as shown by the histological assay). Biodistribution analysis by NLR-M{sub 2} measurements evidenced the many-fold increase (~40) in the tumor-to-normal brain uptake ratio in the Hsp70-conjugates treated animals. Biodistribution pattern of Hsp70-decorated nanoparticles differed from that of non-conjugated SPIONs. Coating of the magnetic nanoparticles with Hsp70 protein enhances the tumor-targeting ability of the conjugates that could be applied in the MR imaging of the malignant brain tumors. - Highlights: • Second-harmonic nonlinear magnetic response is used for biodistribution analysis. • NLR-M{sub 2} ensures high sensibility in detection of SPIONs in tissue. • SPION–Hsp70 conjugates

  20. Heat Shock Proteins 60 and 70 Specific Proinflammatory and Cytotoxic Response of CD4+CD28null Cells in Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Ashok K. Yadav

    2013-01-01

    Full Text Available Background. CD4+CD28null T cells are expanded in peripheral blood of patients with chronic kidney disease and associated with subclinical atherosclerosis. However, triggers for the oligoclonal expansion and activation of these cells are not clear. Methods. We investigated twenty-five stage V-IV chronic kidney disease (CKD patients and eight healthy subjects (HC. Peripheral mononuclear cells were isolated and incubated with heat shock protein- (HSP 60 and 70. CD4+CD28null and CD4+CD28+ cells were sorted by flowcytometry and antigen specific response was assessed by the mRNA and protein expression of interferon (IFN-γ, perforin, and granzyme B using qRT-PCR and Elispot. Results. The basal mRNA expression of IFN-γ, perforin, and granzyme B in CD4+CD28null cells was higher in subjects with CKD compared to that in HC (P<0.0001. Subjects with CKD also showed expression of IFN-γ, perforin, and granzyme B in the CD4+CD28+ subset, but this was much weaker than that seen in the CD4+CD28null population (P<0.0001. We did not note the expression of these molecules at mRNA or protein level in either subset of CD4 cells in HC. After incubation with HSP60 and HSP70, CD4+CD28null cells showed increased expression at mRNA (P<0.001 and protein level (P<0.001. CD4+CD28+ cells also showed a weak increase in expression. No antigen-specific response was noted in HC. Conclusion. These data show that CD4+CD28null cells in subjects with CKD react with HSP60 and HSP70 by upregulating the expression of IFN-γ, perforin and granzyme B. Increased circulating level of HSP60 and HSP70 might play a role in initiation and/or progression of atherosclerosis in CKD subjects through perturbation of CD4+CD28null cells.

  1. Proposed gas generation assembly would recover deeply submerged objects

    Science.gov (United States)

    Sprague, C. W.

    1968-01-01

    Gas generation system, used for recovery of submerged objects, generates hydrogen gas by the reaction of sodium with sea water. The assembly consists of flooded flotation tanks cabled together, equipped with relief valves to equalize pressure as the array ascends and hydrostatic pressure diminishes, and carrying remotely activated welding units.

  2. Implementation of Submerged Arc Welding Training. Final Report.

    Science.gov (United States)

    Bowick, Earl; Todd, John

    A unit on submerged arc welding (SAW) was developed and integrated into the welding program at Seattle Central Community College (Washington) during the period December 1983 through May 1984. During this time, 10 major users of SAW in the area were contacted and mailed questionnaires. Follow up consisted of telephone calls and personal contact as…

  3. Benthic Bacterial Diversity in Submerged Sinkhole Ecosystems▿ †

    Science.gov (United States)

    Nold, Stephen C.; Pangborn, Joseph B.; Zajack, Heidi A.; Kendall, Scott T.; Rediske, Richard R.; Biddanda, Bopaiah A.

    2010-01-01

    Physicochemical characterization, automated ribosomal intergenic spacer analysis (ARISA) community profiling, and 16S rRNA gene sequencing approaches were used to study bacterial communities inhabiting submerged Lake Huron sinkholes inundated with hypoxic, sulfate-rich groundwater. Photosynthetic cyanobacterial mats on the sediment surface were dominated by Phormidium autumnale, while deeper, organically rich sediments contained diverse and active bacterial communities. PMID:19880643

  4. Effects of submerged and anaerobic fermentations on cassava flour ...

    African Journals Online (AJOL)

    Oke Oluwatoyin Victoria

    2015-03-18

    Mar 18, 2015 ... Cassava tubers for processing into cassava flour, Lafun a Nigerian locally fermented product was subjected to two different types of fermentations: submerged and anaerobic fermentation for 72 h. Physicochemical changes that occurred during fermentation and their influence on the functional, rheological ...

  5. Surface Intermediate Zone of Submerged Turbulent Buoyant Jet in Current

    DEFF Research Database (Denmark)

    Chen, H. B.; Larsen, Torben

    1995-01-01

    This paper deals with the intermediate zone between the jet and plume stages of a submerged buoyant discharge from sea outfall in current. The stability criteria, plume width and height after the intermediate zone and the dilution within the intermediate region have been studied theoretically and...

  6. Effects of prolonged elevated water salinity on submerged ...

    African Journals Online (AJOL)

    environmental change, global warming. * To whom all correspondence should be addressed. e-mail: ian.russell@sanparks.org. Received 9 March 2017; accepted in revised form 10 October 2017. INTRODUCTION. Estuarine submerged macrophyte communities can be highly variable at both spatial and temporal scales, ...

  7. Protein enrichment of cassava peel by submerged fermentation ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... Key words: Cassava peel, Trichoderma viride, enzyme, submerged fermentation, protein, amino acids. INTRODUCTION. Protein-energy malnutrition remains a major public health problem in many developing countries and there is the need to increase daily intake of protein, especially animal protein, using ...

  8. Relationships between the biomass of waterfowl and submerged ...

    African Journals Online (AJOL)

    The Wilderness Lakes system, comprising three estuarine lakes (Eilandvlei, Langvlei and Rondevlei), supports a diverse waterbird community, which includes 12 duck species and the abundant Red-knobbed Coot Fulica cristata. Biannual counts of waterfowl (ducks and Red-knobbed Coot) and assessments of submerged ...

  9. Protein enrichment of cassava peel by submerged fermentation with ...

    African Journals Online (AJOL)

    Protein enrichment of cassava peel by submerged fermentation with Trichoderma viride (ATCC 36316). OO Ezekiel, OC Aworh, HP Blaschek, TC Ezeji. Abstract. Cassava (Manihot esculenta Crantz) peel is one of the solid wastes produced as a consequence of cassava processing. It is low in protein but contains a large ...

  10. Nitrification in a submerged attached growth bioreactor using Luffa ...

    African Journals Online (AJOL)

    A laboratory-scale submerged attached growth bioreactor using Luffa cylindrica as support material for the immobilization of nitrifying bacteria was applied for polishing the effluent of an UASB reactor treating domestic wastewater under the tropical conditions of northeast Brazil, in the City of Campina Grande (7o 13' 11” ...

  11. Effects of submerged vegetation on water clarity across climates

    NARCIS (Netherlands)

    Kosten, S.; Lacerot, G.; Jeppesen, E.; Motta Marques, D.M.L.; Nes, van E.H.; Mazzeo, N.; Scheffer, M.

    2009-01-01

    A positive feedback between submerged vegetation and water clarity forms the backbone of the alternative state theory in shallow lakes. The water clearing effect of aquatic vegetation may be caused by different physical, chemical, and biological mechanisms and has been studied mainly in temperate

  12. Precursors to Interstellar Shocks of Solar Origin

    Science.gov (United States)

    Gurnett, D. A.; Kurth, W. S.; Stone, E. C.; Cummings, A. C.; Krimigis, S. M.; Decker, R. B.; Ness, N. F.; Burlaga, L. F.

    2015-12-01

    On or about 2012 August 25, the Voyager 1 spacecraft crossed the heliopause into the nearby interstellar plasma. In the nearly three years that the spacecraft has been in interstellar space, three notable particle and field disturbances have been observed, each apparently associated with a shock wave propagating outward from the Sun. Here, we present a detailed analysis of the third and most impressive of these disturbances, with brief comparisons to the two previous events, both of which have been previously reported. The shock responsible for the third event was first detected on 2014 February 17 by the onset of narrowband radio emissions from the approaching shock, followed on 2014 May 13 by the abrupt appearance of intense electron plasma oscillations generated by electrons streaming outward ahead of the shock. Finally, the shock arrived on 2014 August 25, as indicated by a jump in the magnetic field strength and the plasma density. Various disturbances in the intensity and anisotropy of galactic cosmic rays were also observed ahead of the shock, some of which are believed to be caused by the reflection and acceleration of cosmic rays by the magnetic field jump at the shock, and/or by interactions with upstream plasma waves. Comparisons to the two previous weaker events show somewhat similar precursor effects, although differing in certain details. Many of these effects are very similar to those observed in the region called the "foreshock" that occurs upstream of planetary bow shocks, only on a vastly larger spatial scale.

  13. Shocks in collisionless plasmas

    Science.gov (United States)

    Parks, G. K.; Lee, E.; Fu, S. Y.; Lin, N.; Liu, Y.; Yang, Z. W.

    2017-12-01

    The Earth's bow shock is the best-known collisionless shock in space. Although much is known about the bow shock, the mechanisms of heating and thermalization processes still remain poorly understood. Collisionless shocks are different from ordinary fluid shocks, because a fraction of the incident solar wind is reflected from the bow shock and the transmitted particles are not immediately thermalized. The reflected particles interact with the incident solar wind producing waves and instabilities that can heat and accelerate particles to high energies. Some of the waves can grow to large amplitudes such as Short Large Amplitude Magnetic Structures. Other upstream nonlinear structures include hot flow anomalies and density holes. The upstream nonlinear structures subsequently convect Earthward with the SW and could impact the structure and dynamics of the bow shock. These observations have clearly indicated that the upstream dynamics are an integral part of the bow shock system. Although much has been learned about the behavior of Earth's bow shock dynamics from the existing data, many fundamental questions remain not answered. This article will review observations of ion dynamics of Earth's bow shock system, what we have learned from recent and past observations. We provide new perspectives from multi-spacecraft Cluster observations about the spatial and temporal variations including the fundamental shock heating, acceleration, and entropy generation processes.

  14. A Transmission Electron Microscope Study of Experimentally Shocked Pregraphitic Carbon

    Science.gov (United States)

    Rietmeijer, Frans J. M.

    1995-01-01

    A transmission electron microscope study of experimental shock metamorphism in natural pre-graphitic carbon simulates the response of the most common natural carbons to increased shock pressure. The d-spacings of this carbon are insensitive to the shock pressure and have no apparent diagnostic value, but progressive comminution occurs in response to increased shock pressure up to 59.6 GPa. The function, P = 869.1 x (size(sub minimum )(exp -0.83), describes the relationship between the minimum root-mean-square subgrain size (nm) and shock pressure (GPa). While a subgrain texture of natural pregraphitic carbons carries little information when pre-shock textures are unknown, this texture may go unnoticed as a shock metamorphic feature.

  15. Climate Shocks and the Timing of Migration from Mexico.

    Science.gov (United States)

    Nawrotzki, Raphael J; DeWaard, Jack

    2016-09-01

    Although evidence is increasing that climate shocks influence human migration, it is unclear exactly when people migrate after a climate shock. A climate shock might be followed by an immediate migration response. Alternatively, migration, as an adaptive strategy of last resort, might be delayed and employed only after available in-situ (in-place) adaptive strategies are exhausted. In this paper, we explore the temporally lagged association between a climate shock and future migration. Using multilevel event-history models, we analyze the risk of Mexico-U.S. migration over a seven-year period after a climate shock. Consistent with a delayed response pattern, we find that the risk of migration is low immediately after a climate shock and increases as households pursue and cycle through in-situ adaptive strategies available to them. However, about three years after the climate shock, the risk of migration decreases, suggesting that households are eventually successful in adapting in-situ.

  16. Shock, post-shock annealing, and post-annealing shock in ureilites

    Science.gov (United States)

    Rubin, Alan E.

    2006-01-01

    The thermal and shock histories of ureilites can be divided into four periods: 1) formation, 2) initial shock, 3) post-shock annealing, and 4) post-annealing shock. Period 1 occurred ˜4.55 Ga ago when ureilites formed by melting chondritic material. Impact events during period 2 caused silicate darkening, undulose to mosaic extinction in olivines, and the formation of diamond, lonsdaleite, and chaoite from indigenous carbonaceous material. Alkali-rich fine-grained silicates may have been introduced by impact injection into ureilites during this period. About 57% of the ureilites were unchanged after period 2. During period 3 events, impact-induced annealing caused previously mosaicized olivine grains to become aggregates of small unstrained crystals. Some ureilites experienced reduction as FeO at the edges of olivine grains reacted with C from the matrix. Annealing may also be responsible for coarsening of graphite in a few ureilites, forming euhedral-appearing, idioblastic crystals. Orthopyroxene in Meteorite Hills (MET) 78008 may have formed from pigeonite by annealing during this period. The Rb-Sr internal isochron age of ˜4.0 Ga for MET 78008 probably dates the annealing event. At this late date, impacts are the only viable heat source. About 36% of ureilites experienced period 3 events, but remained unchanged afterwards. During period 4, ˜7% of the ureilites were shocked again, as is evident in the polymict breccia, Elephant Moraine (EET) 83309. This rock contains annealed mosaicized olivine aggregates composed of small individual olivine crystals that exhibit undulose extinction. Ureilites may have formed by impact-melting chondritic material on a primitive body with heterogeneous O isotopes. Plagioclase was preferentially lost from the system due to its low impedance to shock compression. Brief melting and rapid burial minimized the escape of planetary-type noble gases from the ureilitic melts. Incomplete separation of metal from silicates during impact

  17. Radiative shocks in gas on the Omega laser

    Science.gov (United States)

    Reighard, A.; Drake, R. P.; Keiter, P.; Korreck, K. E.; Perry, T. S.; Robey, H. A.; Remington, B. A.; Wallace, R. J.; Ryutov, D. D.; Knauer, J.; Calder, A.; Rosner, R.; Fryxell, B.; Arnett, D.; Turner, N.; Stone, J.; Koenig, M.; Bouquet, Serge

    2002-11-01

    A number of astrophysical systems involve radiative shocks that collapse spatially in response to the energy lost through radiation. This is believed to produce thin, dense, unstable shells. We have begun experiments on the Omega laser intended to produce such collapsing shocks and to study their evolution. The experiments use the laser to accelerate a thin slab of Be, which becomes a piston that drives a shock through 1.1 atm of Ar gas at 100 km/s. The shock is predicted to collapse. Experiments are in preparation that will detect the dense layer and also the radiative precursor in front of the shock. We will report their results.

  18. Effect of multiple microsporidian infections and temperature stress on the heat shock protein 70 (hsp70) response of the amphipod Gammarus pulex

    Science.gov (United States)

    2014-01-01

    Background Increasing temperatures can be a significant stressor for aquatic organisms. Amphipods are one of the most abundant and functionally important groups of freshwater macroinvertebrates. Therefore, we conducted a laboratory experiment with Gammarus pulex, naturally infected with microsporidians. Methods In each group, 42 gammarids were exposed to 15°C and 25°C for 24 h. Sex of gammarids was determined and microsporidian infections were detected by specific PCR. To quantify stress levels of the amphipods, the 70 kDa heat shock proteins (hsp70) were analyzed by western blot. Results More males than females were detected in the randomized population sample (ratio of females/males: 0.87). No mortality occurred at 15°C, while 42.9% of gammarids died at 25°C. Sequences of three microsporidians (M1, M2, M3) were detected in this G. pulex population (99.7%-100% sequence identity to Microsporidium spp. from GenBank). Previous studies showed that M3 is vertically transmitted, while M1 and M2 are presumably horizontally transmitted. Prevalences, according to PCR, were 27.0%, 37.8% and 64.9% for Microsporidium sp. M1, M2 and M3, respectively. Cumulative prevalence was 82.4%. Multiple infections with all three microsporidians in single gammarids were detected with a prevalence of 8.1%, and bi-infections ranged between 12.2% and 25.7%. In dead gammarids, comparatively low prevalences were noted for M1 (males and females: 11.1%) and M2 (females: 11.1%; males 0%), while prevalence of M3 was higher (females: 66.7%; males: 88.9%). No significant effect of host sex on microsporidian infection was found. Significant effects of temperature and bi-infection with Microsporidium spp. M2 + M3 on hsp70 response were detected by analysis of the whole sample (15°C and 25°C group) and of M2 + M3 bi-infection and gammarid weight when analyzing the 25°C group separately. None of the parameters had a significant effect on hsp70 levels in the 15°C group. Conclusion This

  19. Molecular Cloning and mRNA Expression of Heat Shock Protein Genes and Their Response to Cadmium Stress in the Grasshopper Oxya chinensis.

    Directory of Open Access Journals (Sweden)

    Yuping Zhang

    Full Text Available Heat shock proteins (Hsps are highly conserved molecular chaperones that are synthesized in response to stress. In this study, we cloned the full-length sequences of the Grp78 (glucose-regulated protein 78, Hsp70, Hsp90, and Hsp40 genes from the Chinese rice grasshopper Oxya chinensis. The full-length cDNA sequences of OcGrp78, OcHsp70, OcHsp90, and OcHsp40 contain open reading frames of 1947, 1920, 2172, and 1042 bp that encode proteins of 649, 640, 724, and 347 amino acids, respectively. Fluorescent real-time quantitative PCR (RT-qPCR was performed to quantify the relative transcript levels of these Hsp genes in different tissues and developmental stages. The mRNAs encoding these four Hsp genes were present at all developmental stages and in all tissues examined but were expressed at varying levels. Additionally, we investigated the mRNA expression profiles of these four Hsps in O. chinensis subjected to Cadmium (Cd stress. OcGrp78, OcHsp70, OcHsp90, and OcHsp40 mRNA expression was induced under acute Cd stress; the levels reached a maximum within a short time (6 h, were reduced significantly at 12 h, and were lowered to or below control levels by 48 h. Regarding induction efficiency, OcHsp70 was the most sensitive gene to acute Cd stress. Chronic Cd exposure showed that dietary Cd treatment induced increased OcGrp78, OcHsp90, and OcHsp40 expression. However, dietary Cd induced a significant reduction of OcHsp70 expression. In the period tested, no significant difference in the mortality of the grasshoppers was observed. Our results suggest that these four Hsps genes, especially OcHsp70, are sensitive to acute Cd stress and could be used as molecular markers for toxicology studies. However, our results also indicate that OcHsp70 is not suitable for use as a molecular marker of chronic Cd contamination.

  20. Implications of heterogeneity in the shock wave propagation of dynamically shocked materials

    Science.gov (United States)

    LaJeunesse, Jeff

    The field of shock physics as a whole has only recently begun to pay particular attention to modeling heterogeneous materials under shock loading. These materials are important because of their practicality in terms of creating stronger, more shock resistant materials. To understand why they absorb shock impact energy better than homogeneous materials means that the small-scale processes that occur during the shock loading of these heterogeneous materials needs to be understood. Recent computational experiments, called mesoscale simulations, have shown that explicitly incorporating small-scale heterogeneous features into hydrocode simulations allows the bulk shock response of the heterogeneous material to be observed while not requiring the use of empirically determined constitutive equations. Including these features in simulations can offer insights into the irreversible mechanisms that dominate the propagation of shock waves in heterogeneous materials. Three cases where the mesoscale approach for modeling the dynamic shock loading of heterogeneous materials are presented. These materials fall into three categories: granular - dry sand, granular with binder - concrete, and granular contained in a metal foam with a binder - granular explosive contained in an aluminum foam. The processes in which shock waves propagate through each material are addressed and relationships between the three materials are discussed. Particle velocity profiles for dry sand and concrete was obtained from Harvard University and Eglin Air Force Base, respectively. Mesoscale simulations using CTH are conducted for each type of heterogeneous material and the results are compared to the experimental data.

  1. Generation of complement molecular complex C5b-9 (C5b-9) in response to poly-traumatic hemorrhagic shock and evaluation of C5 cleavage inhibitors in non-human primates.

    Science.gov (United States)

    Paredes, R Madelaine; Reyna, Sarah; Vernon, Philip; Tadaki, Douglas K; Dallelucca, Jurandir J; Sheppard, Forest

    2018-01-01

    Severe trauma initiates a systemic inflammatory cascade and that involves early activation of complement and cleavage of C5 into C5a (anaphylatoxin) and C5b (C5b-9 membrane attack complex). We examined activation of C5 in non-human primate (NHP) models of hemorrhagic shock. Blood plasma concentrations of C5b-9 were significantly increased in NHPs in response to hemorrhage alone and were further increased with the addition of tissue trauma. The onset of increased C5 cleavage was accelerated in NHPs that experienced decompensated poly-traumatic hemorrhagic shock. Next, to identify an effective inhibitor of NHP C5 cleavage in vitro, as a first step in the development of a potential therapy, three inhibitors of human C5 cleavage and hemolysis were tested in vitro. NHP C5 cleavage and complement-mediated hemolysis were successfully inhibited by pre-treatment of serum samples with a small, inhibitory peptide RA101348. Commercially-available C5 inhibitory antibodies were found to exhibit species-specific efficacy in vitro. Quidel's A217 antibody demonstrated dose-dependent inhibition of C5 cleavage and hemolysis in NHP samples, whereas LGM-Eculizumab only inhibited complement-mediated hemolysis in human samples. This study shows that complement activation in NHPs following experimental poly-traumatic hemorrhagic shock is consistent with clinical reports, and that cleavage of C5 and complement-mediated hemolysis can be effectively inhibited in vitro using a small peptide inhibitor. Taken together, these findings offer a clinically-relevant vehicle and a potential strategy for treatment of hemorrhagic shock with poly-traumatic injury. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Applying the seedling-emergence method under waterlogged conditions to detect the seed bank of aquatic plants in submerged sediments

    NARCIS (Netherlands)

    Boedeltje, G; ter Heerdt, GNJ; Bakker, JP

    Seed bank studies focused on submerged aquatic plants are generally performed under submerged conditions, using the seedling-emergence method. However, if a study targets at both submerged species and helophytes, submerged conditions are generally not suitable. We tested the emergence of seedlings

  3. Patterns of indole alkaloids synthesis in response to heat shock, 5-azacytidine and Na-butyrate treatment of cultured catharanthus roseus mesophyll protoplasts

    Energy Technology Data Exchange (ETDEWEB)

    Saleem, M.; Cutler, A.J.

    1986-04-01

    Alkaloids of C. roseus are in high demand for therapeutic and other reasons. Cultured Catharanthus cells can produce limited quantities of these alkaloids. The authors have found that cultured mesophyll protoplasts in the presence of /sup 14/C-Tryptamine are capable of synthesizing alkaloids. The pattern of alkaloids synthesis changes when protoplasts are subjected to a heat shock at 37/sup 0/C. The heat shocked protoplasts incorporated 33% more /sup 14/C-Tryptamine and produced 3 new types of alkaloids. Treatment of protoplasts with 5-azacytidine, a DNA hypomethylating agent and Na-butyrate which induces hyperacetylation of histones produced qualitative and quantitative changes in the alkaloid pattern. Four new alkaloids following the above treatments were detected by TLC and HPLC of the extracts. It is suggested that the alkaloid pattern of the cultured protoplasts can be altered by treatment with compounds known as regulators of gene expression. Work is in progress to isolate and identify these new alkaloids.

  4. Shock activation of catalysts

    Science.gov (United States)

    Graham, R. A.; Morosin, B.; Richards, P. M.; Stohl, F. V.; Granoff, B.

    1981-02-01

    Scientists in the Soviet Union have demonstrated that high pressure shock-wave loading can cause significant improvement in the performance of catalysts. This increased catalytic activity is apparently the result of the shock-induced defects, especially vacancies, which act to facilitate atomic migration. We have carried out shock activation experiments on a coal-derived pyrite which has been previously used as a catalyst in coal liquefaction studies. The pyrite powder was packed to a density of about 2.0 Mg/m3 in a copper capsule and explosively loaded to a pressure of about 15 GPa in the copper. The starting and shock-activated samples were analyzed by x-ray diffraction and magnetization measurements. The diffraction patterns of the shock-activated samples were dominated by broadened pyrite lines indicative of a significant increase in crystal defects. The diffraction patterns also showed the presence of pyrrhotite (Fe1-xS) in quantities of a few percent. An iron carbide found in the shocked material was apparently formed from carbon originating from either the calcite or organic impurities in the starting material. Magnetic properties of the sample were found to be substantially changed by the shock loading. The study has demonstrated that shock loading can significantly alter the crystalline order of pyrite and produce measurable quantities of pyrrhotite. The effects of shock-activated pyrite on the liquefaction of coal are being assessed by means by tubing reactor experiments.

  5. Shock Metamorphism in L Chondrites Above Shock Stage S6

    Science.gov (United States)

    Hu, J.; Sharp, T. G.; De Carli, P. S.

    2013-09-01

    We investigated several L6 chondrites shocked to between stage S6 and whole rock melting. The study presents the effects of high post-shock temperature and the annealing of high-pressure evidence in highly shocked chondrites.

  6. Impaired Fracture Healing after Hemorrhagic Shock

    Directory of Open Access Journals (Sweden)

    Philipp Lichte

    2015-01-01

    Full Text Available Impaired fracture healing can occur in severely injured patients with hemorrhagic shock due to decreased soft tissue perfusion after trauma. We investigated the effects of fracture healing in a standardized pressure controlled hemorrhagic shock model in mice, to test the hypothesis that bleeding is relevant in the bone healing response. Male C57/BL6 mice were subjected to a closed femoral shaft fracture stabilized by intramedullary nailing. One group was additionally subjected to pressure controlled hemorrhagic shock (HS, mean arterial pressure (MAP of 35 mmHg for 90 minutes. Serum cytokines (IL-6, KC, MCP-1, and TNF-α were analyzed 6 hours after shock. Fracture healing was assessed 21 days after fracture. Hemorrhagic shock is associated with a significant increase in serum inflammatory cytokines in the early phase. Histologic analysis demonstrated a significantly decreased number of osteoclasts, a decrease in bone quality, and more cartilage islands after hemorrhagic shock. μCT analysis showed a trend towards decreased bone tissue mineral density in the HS group. Mechanical testing revealed no difference in tensile failure. Our results suggest a delay in fracture healing after hemorrhagic shock. This may be due to significantly diminished osteoclast recruitment. The exact mechanisms should be studied further, particularly during earlier stages of fracture healing.

  7. Radiation from Shock-Accelerated Particles

    Science.gov (United States)

    Nishikawa, Ken-ichi; Choi, E. J.; Min, K. W.; Niemiec, J.; Zhang, B.; Hardee, P.; Mizuno, Y.; Medvedev, M.; Nordlund, A.; Frederiksen, J.; hide

    2012-01-01

    Plasma instabilities excited in collisionless shocks are responsible for particle acceleration, generation of magnetic fields , and associated radiation. We have investigated the particle acceleration and shock structure associated with an unmagnetized relativistic jet propagating into an unmagnetized plasma. Cold jet electrons are thermalized and slowed while the ambient electrons are swept up to create a partially developed hydrodynamic-like shock structure. The shock structure depends on the composition of the jet and ambient plasma (electron-positron or electron-ions). Strong electromagnetic fields are generated in the reverse , jet shock and provide an emission site. These magnetic fields contribute to the electron's transverse deflection behind the shock. We have calculated, self-consistently, the radiation from electrons accelerated in the turbulent magnetic fields. We found that the synthetic spectra depend on the Lorentz factor of the jet, its thermal temperature and strength of the generated magnetic fields. The detailed properties of the radiation are important for understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jet shocks, and supernova remnants

  8. Methods for geothermal reservoir detection emphasizing submerged environments

    Energy Technology Data Exchange (ETDEWEB)

    Case, C.W.; Wilde, P.

    1976-05-21

    This report has been prepared for the California State Lands Commission to aid them in evaluating exploration programs for geothermal reservoirs, particularly in submerged land environments. Three charts show: (1) a logical progression of specific geologic, geochemical, and geophysical exploration techniques for detecting geothermal reservoirs in various geologic environments with emphasis on submerged lands, (2) various exploration techniques which can be used to develop specific information in geothermal areas, and (3) if various techniques will apply to geothermal exploration according to a detailed geologic classification. A narrative in semi-outline form supplements these charts, providing for each technique; a brief description, advantages, disadvantages, special geologic considerations, and specific references. The specific geologic situation will control the exploration criterion to be used for reservoir detection. General guidelines are established which may be of use in evaluating such a program, but the optimum approach will vary with each situation.

  9. Antitumor activity of submerged biomass of Hericium erinaceus

    OpenAIRE

    Avtonomova, A.; Bakanov, A.; Vinokurov, V.; Bukhman, V.; Krasnopolskaya, L.

    2011-01-01

    Submerged cultivation of Hericium erinaceus in various media has been studied. The yield of biomass was shown to depend mainly on the carbon source, whereas the content of watersoluble polysaccharides depended primarily on the nitrogen source. Using optimal medium composition, the biomass yield of 22-23 g/l in 7 days was achieved. The antitumor activity was studied in vivo with using 2 tumor strains. The inhibition ratio of tumor in these experience reached 86%. An exposure of mice with tumor...

  10. Submerged beachrock preservation in the context of wave ravinement

    Science.gov (United States)

    Pretorius, Lauren; Green, Andrew N.; Andrew Cooper, J.

    2018-02-01

    This study examines a Holocene-aged submerged shoreline, Limestone Reef, located in the shallow subtidal zone of South Africa's east coast. It comprises an elongate, coast-oblique, slab-like outcrop of beachrock situated above the contemporary fair-weather wave base. It is currently undergoing mechanical disintegration. Its unique and rare preservation in a high-energy setting affords an opportunity to examine the mechanical processes occurring during wave ravinement associated with rising sea level. The submerged shoreline and the adjacent shoreface were examined using high-resolution seismic reflection, side-scan sonar and shallow-water multibeam echosounding techniques. Limestone Reef rests on top of unconsolidated Holocene deposits. The structure's surface is characterised by reef-perpendicular gullies with rubble derived from the slab fringing its seaward edge. Limestone Reef slopes gently seawards and has a steep landward-facing edge where gullies are most prominently developed. Teardrop-shaped rippled scour depressions, marked by high backscatter, are located seawards of the submerged shoreline. These elongate in a seaward direction and are filled with bioclastic gravels and residual rubble from Limestone Reef. The gullies in the upstanding structure are indicative of wave plucking and abrasion of the shoreline. The material exposed by the rippled scour depressions is identical to that comprising the postglacial ravinement surface identified in the offshore stratigraphy. These deposits are considered to represent the contemporary, actively forming wave ravinement surface. The results suggest that wave ravinement of submerged shorelines is a discontinuous process dominated by the seaward entrainment of material from its landward edge controlled by high-energy drawback during storm surges. The ravinement process appears to operate at the seasonal scale and averages out over the long-term millennial scale for the continuous surface.

  11. Submerged Pagodas of Mahabalipuram - Study based on underwater investigations

    Digital Repository Service at National Institute of Oceanography (India)

    Sundaresh; Gaur, A.S.; Tripati, S.; Vora, K.H.; Rao, K.M.

    - gested that this place could have served as an ancient port (Dayalan, 1992). Mahabalipuram was well known to earlier mariners as 'Seven Pagodas' since the 1 7h century AD. it is generally believed that out of 7 temples originally con- structed, all... based on the local traditions and available literature. The local tradition and the people of Mahabalipuram believe that five temples similar to the Shore Temple have been submerged in the sea. On the basis of local traditions Ancient Tamil...

  12. Instrumentation, control, and automation for submerged anaerobic membrane bioreactors

    OpenAIRE

    Robles Martínez, Ángel; Durán Pinzón, Freddy; Ruano García, María Victoria; Ribes Bertomeu, José; Rosado Muñoz, Alfredo; SECO TORRECILLAS, AURORA; Ferrer, J.

    2015-01-01

    A submerged anaerobic membrane bioreactor (AnMBR) demonstration plant with two commercial hollow-fibre ultrafiltration systems (PURON® , Koch Membrane Systems, PUR-PSH31) was designed and operated for urban wastewater treatment. An instrumentation, control, and automation (ICA) system was designed and implemented for proper process performance. Several single-input-single-output (SISO) feedback control loops based on conventional on off and PID algorithms were implemented to control the follo...

  13. On the submerging of a spherical intruder into granular beds

    Science.gov (United States)

    Wu, Chuan-Yu; Zhang, Ling; Chen, Lan

    2017-06-01

    Granular materials are complex systems and their mechanical behaviours are determined by the material properties of individual particles, the interaction between particles and the surrounding media, which are still incompletely understood. Using an advanced discrete element method (DEM), we simulate the submerging process of a spherical projectile (an intruder) into granular materials of various properties with a zero penetration velocity (i.e. the intruder is touching the top surface of the granular bed and released from stationary) and examine its settling behaviour. By systematically changing the density and size of the intruder and the particle density (i.e. the density of the particles in the granular bed), we find that the intruder can sink deep into the granular bed even with a zero penetration velocity. Furthermore, we confirm that under certain conditions the granular bed can behave like a Newtonian liquid and the submerging intruder can reach a constant velocity, i.e. the terminal velocity, identical to the settling of a sphere in a liquid, as observed experimentally. A mathematical model is also developed to predict the maximum penetration depth of the intruder. The model predictions are compared with experimental data reported in the literature,good agreement was obtained, demonstrating the model can accurately predict the submerging behaviour of the intruder in the granular media.

  14. Research efforts for detection and recovery of submerged oil

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, K. [United States Coast Guard, Groton, CT (United States). Research and Development Center

    2009-07-01

    Submerged oil can sink and destroy shellfish and other marine populations in addition to causing closure of water intakes at industrial facilities and power plants. However, current methods to find and recover oil from spills involving submerged oil are inadequate. The underwater environment presents major challenges such as poor visibility, difficulty in tracking oil spill movement, colder temperatures, inadequate containment methods and problems with the equipment's interaction with water. This paper reported on a multi-year project launched by the Research and Development Center of the United States Coast Guard to develop a complete approach for spills of submerged oil. The project involved detection technologies and recovery methods for oil on the bottom of any body of water. Proof of concept (POC) and prototype tests of potential detection technologies were evaluated during tests at the Ohmsett facility in Leonardo, New Jersey. The technologies included sonar, laser fluorometry, real-time mass spectrometry and in-situ fluorometry. This paper described the development of a complete specification for an integrated recovery system along with a plan for future development. 9 refs., 2 tabs., 11 figs.

  15. Production of Alpha Amylase by Bacillus cereus in Submerged Fermentation

    Directory of Open Access Journals (Sweden)

    Helen H. Raplong

    2014-09-01

    Full Text Available Microorganisms have the ability to secrete enzymes when they are grown in the presence of certain substrates. Amylases are among the most important industrial enzymes and are of great significance in biotechnological studies. Bacteria belonging to the genus Bacillus were isolated using mannitol egg yolk polymyxin B (MYP agar a highly selective media for Bacillus cereus isolation. The isolates were tested for α-amylase production on nutrient agar supplemented with starch and in submerged fermentation. The bacteria isolated and identified (using the Microgen Bacillus identification kit were all Bacillus cereus and SB2 had the largest zone of hydrolysis of 12mm on nutrient agar supplemented with starch as well as the highest enzyme activity of 1.62U/ml. Amylase activity of 2.56U/ml was obtained after 24 hours incubation in submerged fermentation. When amylase enzyme production parameters where optimized, maximum amylase activity was obtained at a pH of 6.5, temperature of 350C, incubation time of 24 hours and 4% inoculums concentration. Bacillus cereus SB2 is a potential isolate for alpha-amylase production with soluble starch as the sole carbon source in submerged fermentation.

  16. On the submerging of a spherical intruder into granular beds

    Directory of Open Access Journals (Sweden)

    Wu Chuan-Yu

    2017-01-01

    Full Text Available Granular materials are complex systems and their mechanical behaviours are determined by the material properties of individual particles, the interaction between particles and the surrounding media, which are still incompletely understood. Using an advanced discrete element method (DEM, we simulate the submerging process of a spherical projectile (an intruder into granular materials of various properties with a zero penetration velocity (i.e. the intruder is touching the top surface of the granular bed and released from stationary and examine its settling behaviour. By systematically changing the density and size of the intruder and the particle density (i.e. the density of the particles in the granular bed, we find that the intruder can sink deep into the granular bed even with a zero penetration velocity. Furthermore, we confirm that under certain conditions the granular bed can behave like a Newtonian liquid and the submerging intruder can reach a constant velocity, i.e. the terminal velocity, identical to the settling of a sphere in a liquid, as observed experimentally. A mathematical model is also developed to predict the maximum penetration depth of the intruder. The model predictions are compared with experimental data reported in the literature,good agreement was obtained, demonstrating the model can accurately predict the submerging behaviour of the intruder in the granular media.

  17. Roles of heat shock factors in gametogenesis and development.

    Science.gov (United States)

    Abane, Ryma; Mezger, Valérie

    2010-10-01

    Heat shock factors form a family of transcription factors (four in mammals), which were named according to the first discovery of their activation by heat shock. As a result of the universality and robustness of their response to heat shock, the stress-dependent activation of heat shock factor became a ‘paradigm’: by binding to conserved DNA sequences (heat shock elements), heat shock factors trigger the expression of genes encoding heat shock proteins that function as molecular chaperones, contributing to establish a cytoprotective state to various proteotoxic stress and in several pathological conditions. Besides their roles in the stress response, heat shock factors perform crucial roles during gametogenesis and development in physiological conditions. First, during these process, in stress conditions, they are either proactive for survival or, conversely, for apoptotic process, allowing elimination or, inversely, protection of certain cell populations in a way that prevents the formation of damaged gametes and secure future reproductive success. Second, heat shock factors display subtle interplay in a tissue- and stage-specific manner, in regulating very specific sets of heat shock genes, but also many other genes encoding growth factors or involved in cytoskeletal dynamics. Third, they act not only by their classical transcription factor activities, but are necessary for the establishment of chromatin structure and, likely, genome stability. Finally, in contrast to the heat shock gene paradigm, heat shock elements bound by heat shock factors in developmental process turn out to be extremely dispersed in the genome, which is susceptible to lead to the future definition of ‘developmental heat shock element’.

  18. Recognition of a Kawasaki Disease Shock Syndrome

    Science.gov (United States)

    Kanegaye, John T.; Wilder, Matthew S.; Molkara, Delaram; Frazer, Jeffrey R.; Pancheri, Joan; Tremoulet, Adriana H.; Watson, Virginia E.; Best, Brookie M.; Burns, Jane C.

    2010-01-01

    objective We sought to define the characteristics that distinguish Kawasaki disease shock syndrome from hemodynamically normal Kawasaki disease. methods We collected data prospectively for all patients with Kawasaki disease who were treated at a single institution during a 4-year period. We defined Kawasaki disease shock syndrome on the basis of systolic hypotension for age, a sustained decrease in systolic blood pressure from baseline of ≥20%, or clinical signs of poor perfusion. We compared clinical and laboratory features, coronary artery measurements, and responses to therapy and analyzed indices of ventricular systolic and diastolic function during acute and convalescent Kawasaki disease. results Of 187 consecutive patients with Kawasaki disease, 13 (7%) met the definition for Kawasaki disease shock syndrome. All received fluid resuscitation, and 7 (54%) required vasoactive infusions. Compared with patients without shock, patients with Kawasaki disease shock syndrome were more often female and had larger proportions of bands, higher C-reactive protein concentrations, and lower hemoglobin concentrations and platelet counts. Evidence of consumptive coagulopathy was common in the Kawasaki disease shock syndrome group. Patients with Kawasaki disease shock syndrome more often had impaired left ventricular systolic function (ejection fraction of <54%: 4 of 13 patients [31%] vs 2 of 86 patients [4%]), mitral regurgitation (5 of 13 patients [39%] vs 2 of 83 patients [2%]), coronary artery abnormalities (8 of 13 patients [62%] vs 20 of 86 patients [23%]), and intravenous immunoglobulin resistance (6 of 13 patients [46%] vs 32 of 174 patients [18%]). Impairment of ventricular relaxation and compliance persisted among patients with Kawasaki disease shock syndrome after the resolution of other hemodynamic disturbances. conclusions Kawasaki disease shock syndrome is associated with more-severe laboratory markers of inflammation and greater risk of coronary artery

  19. Our Favorite Film Shocks

    DEFF Research Database (Denmark)

    Willerslev, Rane; Suhr, Christian

    2014-01-01

    The modern medium of film has long been hailed for its capacity for producing shocks of an entertaining, thought-provoking, or even politically emancipative nature. But what is a shock, how and when does it occur, how long does it last, and are there particular techniques for producing cinematic...

  20. Shock Properties of Fansteel85

    Energy Technology Data Exchange (ETDEWEB)

    Erskine, D J; Nellis, W J

    2008-08-22

    The shock response of Fansteel85 was investigated in the pressure range 10-90 GPa. The linear U{sub s}-U{sub p} coefficients were found to be C = 4.160 {+-} .015 km/s and S = 1.195 {+-} .015. Ultrasound measurements yielded C{sub L} = 4.827 and C{sub T} = 2.101, implying a bulk sound speed C{sub B} = 4.173, which is in excellent agreement with the measured value for C. The Hugoniot elastic limit was determined to be 3.11 {+-} .05 GPa at U{sub p} = .0595 {+-} .001 km/s and U{sub s} = 4.886 {+-} .01 km/s. The speed of sound in the material behind the shock front was determined to be 5.10 {+-} .06 km/s at 10.2 GPa and 5.25 {+-} .06 km/s at 20.6 GPa.

  1. Density shock waves in confined microswimmers

    CERN Document Server

    Tsang, Alan Cheng Hou

    2015-01-01

    Motile and driven particles confined in microfluidic channels exhibit interesting emergent behavior from propagating density bands to density shock waves. A deeper understanding of the physical mechanisms responsible for these emergent structures is relevant to a number of physical and biomedical applications. Here, we study the formation of density shock waves in the context of an idealized model of microswimmers confined in a narrow channel and subject to a uniform external flow. Interestingly, these density shock waves exhibit a transition from `subsonic' with compression at the back to `supersonic' with compression at the front of the population as the intensity of the external flow increases. This behavior is the result of a non-trivial interplay between hydrodynamic interactions and geometric confinement, and is confirmed by a novel quasilinear wave model that properly captures the dependence of the shock formation on the external flow. These findings can be used to guide the development of novel mechan...

  2. Reflection of curved shock waves

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Shock curvatures are related to pressure gradients, streamline curvatures and vorticity in flows with planar and axial symmetry. Explicit expressions, in an influence coefficient format, are used to relate post-shock pressure gradient, streamline curvature and vorticity to pre-shock gradients and shock curvature in steady flow. Using higher order, von Neumann-type, compatibility conditions, curved shock theory is applied to calculate the flow near singly and doubly curved shocks on curved surfaces, in regular shock reflection and in Mach reflection. Theoretical curved shock shapes are in good agreement with computational fluid dynamics calculations and experiment.

  3. Antioxidant Properties of the Edible Basidiomycete Armillaria mellea in Submerged Cultures

    OpenAIRE

    Lung, Ming-Yeou; Chang, Yu-Cheng

    2011-01-01

    Antioxidant components, ascorbic acid, total flavonoids and total phenols are produced effectively by Armillaria mellea submerged cultures. Dried mycelia and mycelia-free broths obtained by A. mellea submerged cultures are extracted with methanol and hot water and investigated for antioxidant properties. Methanolic extracts from dried mycelia (MEM) and mycelia-free broth (MEB) and hot water extracts from dried mycelia (HWEM) by A. mellea submerged cultures show good antioxidant properties as ...

  4. Enhanced effects of biotic interactions on predicting multispecies spatial distribution of submerged macrophytes after eutrophication

    OpenAIRE

    Song, Kun; Cui, Yichong; Zhang, Xijin; Pan, Yingji; Xu, Junli; Xu, Kaiqin; Da, Liangjun

    2017-01-01

    Abstract Water eutrophication creates unfavorable environmental conditions for submerged macrophytes. In these situations, biotic interactions may be particularly important for explaining and predicting the submerged macrophytes occurrence. Here, we evaluate the roles of biotic interactions in predicting spatial occurrence of submerged macrophytes in 1959 and 2009 for Dianshan Lake in eastern China, which became eutrophic since the 1980s. For the four common species occurred in 1959 and 2009,...

  5. Pediatric Toxic Shock Syndrome

    Directory of Open Access Journals (Sweden)

    Jennifer Yee

    2017-09-01

    Full Text Available Audience: This scenario was developed to educate emergency medicine residents on the diagnosis and management of a pediatric patient with toxic shock syndrome. The case is also appropriate for teaching of medical students and advanced practice providers, as well as a review of the principles of crisis resource management, teamwork, and communication. Introduction: Toxic shock syndrome is a low-frequency, high-acuity scenario requiring timely identification and aggressive management. If patients suffering from this condition are managed incorrectly, they may progress into multi-organ dysfunction and potentially death. Toxic shock syndrome has been associated with Streptococcus and Staphylococcus aureus (Staph. Approximately half of Staph cases are associated with menstruation, which was first described in the 1970s-1980s and was associated with the use of absorbent tampons.1 Group A Streptococcus may cause complications such as necrotizing fasciitis and gangrenous myositis.2 Pediatric patients may present critically ill from toxic shock syndrome. Providers need to perform a thorough history and physical exam to discern the source of infection. Management requires aggressive care with antibiotics and IV fluids. Objectives: By the end of this simulation session, the learner will be able to: 1 Recognize toxic shock syndrome. 2 Review the importance of a thorough physical exam. 3 Discuss management of toxic shock syndrome, including supportive care and the difference in antibiotic choices for streptococcal and staphylococcal toxic shock syndrome. 4 Appropriately disposition a patient suffering from toxic shock syndrome. 5 Communicate effectively with team members and nursing staff during a resuscitation of a critically ill patient. Method: This session was conducted using high-fidelity simulation, followed by a debriefing session and lecture on toxic shock syndrome.

  6. GigaUnit Transplant System: A New Mechanical Tool for Transplanting Submerged Aquatic Vegetation

    National Research Council Canada - National Science Library

    Shafer, Deborah J

    2008-01-01

    Submerged aquatic vegetation (SAV) performs many important ecosystem functions, including wave attenuation and sediment stabilization, water quality improvement, primary production, food web support for secondary consumers...

  7. Effect of sludge characteristics on membrane fouling during start-up of a tertiary submerged membrane bioreactor.

    Science.gov (United States)

    Díaz, Oliver; Vera, Luisa; González, Enrique; García, Elisa; Rodríguez-Sevilla, Juan

    2016-05-01

    In membrane bioreactors applied to wastewater treatment, fouling is typically a complex function of sludge characteristics. A pilot-scale tertiary submerged membrane bioreactor (tMBR) was continuously operated for over 200 days to assess the effect of biomass physiological state and environmental stress on process performance. Sludge characteristics were evaluated in terms of suspended solid concentration (MLSS and MLVSS), apparent viscosity, bioflocculation state, filterability, bioactivity, biopolymeric clusters (BPCs) and soluble microbial products. During the initial period of the tMBR start-up, when MLSS was below 3000 mg/L, the biomass was found to be very sensitive to environmental stress by sudden oxygen increase or organic shock loading, resulting in temporary biomass deflocculation and BPC release, and consequently, severe induced membrane fouling. However, at higher MLSS values, low stable biomass growth (0.04 ± 0.002 kg MLVSS/kg COD) was measured, regardless of organic overloading shocks or feeding failures. This period was also characterised by low bioactivity, BPC content and membrane fouling. Statistical analysis showed that BPCs have an important role when compared with other sludge properties as indicators of its fouling potential.

  8. Shock breakout theory

    OpenAIRE

    Waxman, Eli; Katz, Boaz

    2016-01-01

    The earliest supernova (SN) emission is produced when the optical depth of the plasma lying ahead of the shock, which ejects the envelope, drops below c/v, where v is the shock velocity. This "breakout" may occur when the shock reaches the edge of the star, producing a bright X-ray/UV flash on time scales of seconds to a fraction of an hour, followed by UV/optical "cooling" emission from the expanding cooling envelope on a day time-scale. If the optical depth of circumstellar material (CSM) e...

  9. CAM Photosynthesis in Submerged Aquatic Plants

    Science.gov (United States)

    Keeley, J.E.

    1998-01-01

    Crassulacean acid metabolism (CAM) is a CO2-concentrating mechanism selected in response to aridity in terrestrial habitats, and, in aquatic environments, to ambient limitations of carbon. Evidence is reviewed for its presence in five genera of aquatic vascular plants, including Isoe??tes, Sagittaria, Vallisneria, Crassula, and Littorella. Initially, aquatic CAM was considered by some to be an oxymoron, but some aquatic species have been studied in sufficient detail to say definitively that they possess CAM photosynthesis. CO2-concentrating mechanisms in photosynthetic organs require a barrier to leakage; e.g., terrestrial C4 plants have suberized bundle sheath cells and terrestrial CAM plants high stomatal resistance. In aquatic CAM plants the primary barrier to CO2 leakage is the extremely high diffusional resistance of water. This, coupled with the sink provided by extensive intercellular gas space, generates daytime CO2(Pi) comparable to terrestrial CAM plants. CAM contributes to the carbon budget by both net carbon gain and carbon recycling, and the magnitude of each is environmentally influenced. Aquatic CAM plants inhabit sites where photosynthesis is potentially limited by carbon. Many occupy moderately fertile shallow temporary pools that experience extreme diel fluctuations in carbon availability. CAM plants are able to take advantage of elevated nighttime CO2 levels in these habitats. This gives them a competitive advantage over non-CAM species that are carbon starved during the day and an advantage over species that expend energy in membrane transport of bicarbonate. Some aquatic CAM plants are distributed in highly infertile lakes, where extreme carbon limitation and light are important selective factors. Compilation of reports on diel changes in titratable acidity and malate show 69 out of 180 species have significant overnight accumulation, although evidence is presented discounting CAM in some. It is concluded that similar proportions of the aquatic

  10. Stress response of Nidula niveo-tomentosa to UV-A light.

    Science.gov (United States)

    Taupp, Daniela E; Nimtz, Manfred; Berger, Ralf G; Zorn, Holger

    2008-01-01

    Exposition to UV-A light stimulated the growth and synthesis of raspberry ketone in submerged cultures of the basidiomycete Nidula niveotomentosa. To investigate the fungus' response to UV-A light differentially expressed proteins were identified by means of 2D-electrophoresis. Light induced proteins were de novo sequenced by ESI-MS/MS spectrometry, and the encoding nucleotide sequences were cloned from cDNA or genomic DNA. The spectrum of UV-A light-induced proteins comprised several stress-related proteins including a catalase, heat-shock proteins, glutathione S-transferases and proteasomes. In addition, growth-related enzymes of the citric cycle were found to be up-regulated as a response to irradiation with UV-A.

  11. Aerobic and anaerobic ethanol production by Mucor circinelloides during submerged growth

    DEFF Research Database (Denmark)

    Lübbehüsen, Tina Louise; Nielsen, Jens; Mcintyre, Mhairi

    2004-01-01

    The dimorphic organism Mucor circinelloides is currently being investigated as a potential host for heterologous protein production. The production of ethanol on pentose and hexose sugars was studied in submerged batch cultivations to further the general knowledge of Mucor physiology, with a view...... to the minimisation or elimination of the by-product ethanol for future process design. Large amounts of ethanol were produced during aerobic growth on glucose under non-oxygen limiting conditions, which is indicative of M. circinelloides being a Crabtree-positive organism. Ethanol production on galactose or xylose...... was less significant. The response of the organism to increased ethanol concentrations, both as the sole carbon source and in the presence of a sugar, was investigated in terms of biomass formation and morphology....

  12. The role of cable stiffness in the dynamic behaviours of submerged floating tunnel

    Directory of Open Access Journals (Sweden)

    Muhammad Naik

    2017-01-01

    Full Text Available Submerged floating tunnel (SFT is a new solution for the transportation infrastructure through sea straits, fjords, and inland waters and can be a good alternative to long span suspension bridges and immersed tunnels. The mooring cables/anchors are main structural components to provide restoring capacity to the SFT. The time domain dynamic problem of SFT moored by vertical and inclined mooring cables/anchors is formulated. The dynamic analysis of SFT subjected to hydrodynamic and seismic excitations is performed. As the cable stiffness determines the deformation ability of SFT, therefore it becomes crucial to evaluate the effect of mooring cable stiffness on the response of SFT. The displacements and internal forces of SFT clearly specify that the vertical/tension leg mooring cables provide very small stiffness as compared to inclined mooring cables. In order to keep the SFT displacements within an acceptable limit, the effect of cable stiffness should be properly evaluated for practical design of SFT.

  13. The Aboriginal Challenge − the Post-Soviet Response: Can the Aboriginal Peoples of Russia Be Rescued from the Modernisation Shock?

    Directory of Open Access Journals (Sweden)

    Vladislav Steljmah

    1998-10-01

    Full Text Available The paper treats the theme of aboriginal/native peoples in Post-Soviet Russia. First the authors ask: how is a people to be defined as aboriginal, or else how can such a people be distinguished from "small ethnic groups" or "ethnic minorities"? They find an answer in Convention No. 169 of the International Labour Organisation, which gives two criteria: a a social type in which pre-state forms are maintained, a more or less traditional economy and remains of collective land ownership, b a specific view of the world, sacralisation of nature, the land and its resources. According to this, 26 ethnic groups in the North and Far East of the Russian Federation can be termed aboriginal. Their total number does not surpass 9% of the population of these areas. Their present situation is marked by crisis, caused, inter alia, by the demise of former economic forms and general deculturation, unequal participation in the modern economy, demographic catastrophe, a poor health situation, aggravated by alcoholism, with also an increase of suicides and depression. The authors find the reasons for this crisis in: 1 the modernisation shock which traditional societies always suffer when coming into contact with industrial or post-industrial societies, 2 crude interference in the Soviet period into traditional modes of livings, 3 an undefined legal status and system for the protection of aboriginals and 4 years of ignoring the opinions of the latter regarding their position in the broader society. The authors identify three models of adaptation to modemisation: full adaptation, partial adaptation and no adaptation. The first is typical of individuals, but on the group level does not preserve ethnicity. The third leads to ethnic self-isolation, which is rare in Russia. The third model dominates − it entails rejection of marginalisation and a striving to be included into the broader society, but not at the expense of ethnic specificity. This was expressed by the

  14. Restoring Ecological Function to a Submerged Salt Marsh

    Science.gov (United States)

    Stagg, C.L.; Mendelssohn, I.A.

    2010-01-01

    Impacts of global climate change, such as sea level rise and severe drought, have altered the hydrology of coastal salt marshes resulting in submergence and subsequent degradation of ecosystem function. A potential method of rehabilitating these systems is the addition of sediment-slurries to increase marsh surface elevation, thus ameliorating effects of excessive inundation. Although this technique is growing in popularity, the restoration of ecological function after sediment addition has received little attention. To determine if sediment subsidized salt marshes are functionally equivalent to natural marshes, we examined above- and belowground primary production in replicated restored marshes receiving four levels of sediment addition (29-42 cm North American Vertical Datum of 1988 [NAVD 88]) and in degraded and natural ambient marshes (4-22 cm NAVD 88). Moderate intensities of sediment-slurry addition, resulting in elevations at the mid to high intertidal zone (29-36 cm NAVD 88), restored ecological function to degraded salt marshes. Sediment additions significantly decreased flood duration and frequency and increased bulk density, resulting in greater soil drainage and redox potential and significantly lower phytotoxic sulfide concentrations. However, ecological function in the restored salt marsh showed a sediment addition threshold that was characterized by a decline in primary productivity in areas of excessive sediment addition and high elevation (>36 cm NAVD 88). Hence, the addition of intermediate levels of sediment to submerging salt marshes increased marsh surface elevation, ameliorated impacts of prolonged inundation, and increased primary productivity. However, too much sediment resulted in diminished ecological function that was equivalent to the submerged or degraded system. ?? 2010 Society for Ecological Restoration International.

  15. Enhanced Sorbitol Production under Submerged Fermentation using Lactobacillus plantarum

    Directory of Open Access Journals (Sweden)

    Khan Nadiya Jan

    2017-04-01

    Full Text Available Background and Objective: Sorbitol is a non-toxic and slightly hygroscopic compound with different applications. Zymomonas mobiles produces sorbitol from sucrose or mixtures of glucose and fructose (formation is coupled with the dehydrogenation of glucose to glucono-δ- lactone. Recombinant Zymomonas mobilis may produce sorbitol and gluconic acid from glucose and fructose using different divalent metal ions with reduced the ethanol yield andsignificantly increased yield of sorbitol. Current study envisaged to alter the media components, physical process parameters and supplementation of amino acids for enhanced sorbitol production.Material and Methods: Several process variables were evaluated on sorbitol production including carbon sources (glucose, fructose, maltose, sucrose, carbon concentrations (5, 10, 20 and 25 g l-1, nitrogen sources (peptone, tryptone, yeast extract, beef extract and organic nitrogen mix, temperatures (25, 29, 33, 37, 41°C, pH (6, 6.5, 7 , 7.5 ,8, agitation rate (50, 100, 150, 200 rpm and amino acids (cysteine, cystine, tryptophanin batch cultivation ofLactobacillus plantarum NCIM 2912. Shake flask cultivation performed under optimum conditions like temperature 37°C, pH 7.0 and agitation rate of 150 rpm, resulted in enhanced sorbitol production. Comparative study of sorbitol production in solid state fermentation and submerged fermentation was also evaluated.Results and Conclusion: Batch cultivation under submerged conditions further performed in 7.5-l lab scale bioreactor (working volume 3.0-l under optimized conditions resulted in maximum cell biomass of 8.95±0.03 g g-1 and a sorbitol content of 9.78±0.04 g l-1 after 42.0 h of fermentation. Scale up study on bioreactor resulted in maximum sorbitol yield (Yp/x and productivity of 1.11 g g-1 and 0.50 g l-1 h under submerged fermentation, respectively.Conflict of interest: The authors declare no conflict of interest.

  16. Shock wave treatment in medicine

    Indian Academy of Sciences (India)

    Extracorporeal shock wave therapy in orthopedics and traumatology is still a young therapy method. Since the last few years the development of shock wave therapy has progressed rapidly. Shock waves have changed the treatment of urolithiasis substantially. Today shock waves are the first choice to treat kidney and ...

  17. [Genetic algorithm for fermentation kinetics of submerged fermentation by Morchella].

    Science.gov (United States)

    Wang, Ying; Piao, Meizi; Sun, Yonghai

    2008-08-01

    Fermentation kinetics is important for optimizing control and up-scaling fermentation process. We studied submerged fermentation kinetics of Morchella. Applying the genetic Algorithm in the Matlab software platform, we compared suitability of the Monod and Logistic models, both are commonly used in process of fungal growth, to describe Morchella growth kinetics. Meanwhile, we evaluated parameters involved in the models for Morchella growth, EPS production and substrate consumption. The results indicated that Logistic model fit better with the experimental data. The average error of this model was 5.8%. This kinetics model can be useful for optimizing and up-scaling fungal fermentation process.

  18. Liquid Film Diffusion on Reaction Rate in Submerged Biofilters

    DEFF Research Database (Denmark)

    Christiansen, Pia; Hollesen, Line; Harremoës, Poul

    1995-01-01

    Experiments were carried out in order to investigate the influence of liquid film diffusion on reaction rate in a submerged biofilter with denitrification and in order to compare with a theoretical study of the mass transfer coefficient. The experiments were carried out with varied flow, identified...... by the empty bed velocity of inflow and recirculation, respectively 1.3, 2.8, 5.6 and 10.9 m/h. The filter material consisted of 3 mm biostyren spheres. The results indicate that the influence of liquid film diffusion on reaction rate can be ignored....

  19. Slag Metal Reactions during Submerged Arc Welding of Alloy Steels

    Science.gov (United States)

    Mitra, U.; Eagar, T. W.

    1984-01-01

    The transfer of Cr, Si, Mn, P, S, C, Ni, and Mo between the slag and the weld pool has been studied for submerged arc welds made with calcium silicate and manganese silicate fluxes. The results show a strong interaction between Cr and Si transfer but no interaction with Mn. The manganese silicate flux produces lower residual sulfur while the calcium silicate fluxes are more effective for removal of phosphorus. The effective oxygen reaction temperature lies between 1700 and 2000 °C for all elements studied. Evidence of Cr and Mn loss by metal vaporization is also presented.

  20. Circulatory shock in horses

    OpenAIRE

    José Monteira da Silva Filho; Maristela Silveira Palhares; Cíntia Ferreira; Ubiratan Pereira de Melo

    2010-01-01

    Circulatory shock can be defined as an acute circulatory failure with an inadequate tissue delivery of oxygen and nutritive substrates to the tissues, resulting in generalised cellular hypoxia. Shock can be classified as cardiogenic, obstructive, hypovolaemic, or distributive. The pathophysiologic consequences of inadequate tissue perfusion are directly related to cell ischemia, inadequate O2 delivery, and the production of proinflammatory mediators. If abnormalities of tissue perfusion are a...

  1. Microbial etiology and clinical characteristics of distributive shock.

    Science.gov (United States)

    Bamberger, D M; Gurley, M B

    1994-05-01

    Although septic shock may be the most common cause of distributive shock, to our knowledge, no studies have defined the likelihood and type of infection among patients with distributive shock. We performed a retrospective study of 100 consecutive patients who were admitted to a city-county hospital with hemodynamic evidence of distributive shock. Forty-nine of 100 patients with distributive shock had microbiological documentation of infection. Six patients had clinical evidence of infection without microbiological documentation. Forty-five patients had no microbiological or clinical evidence of infection. Among patients with microbiologically documented infections, the incidence of infection due to aerobic gram-positive cocci equaled the incidence of infection due to aerobic gram-negative bacilli. Clinical parameters, such as the criteria for the systemic inflammatory response syndrome, were not useful in distinguishing the group with infections from the group without infections. In conclusion, many patients with distributive shock do not have evidence of infection.

  2. Simulation of Relativistic Shocks and Associated Self-Consistent Radiation

    Science.gov (United States)

    Nishikawa, K.-I.; Niemiec, J.; Medvedev, M.; Zhang, B.; Hardee, P.; Mizuno, Y.; Nordlund, A.; Frederiksen, J.; Sol, H.; Pohl, M.; hide

    2010-01-01

    Plasma instabilities excited in collisionless shocks are responsible for particle acceleration. We have investigated the particle acceleration and shock structure associated with an unmagnetized relativistic electron-positron jet propagating into an unmagnetized electron-positron plasma. Cold jet electrons are thermalized and slowed while the ambient electrons are swept up to create a partially developed hydrodynamic-like shock structure. In the leading shock, electron density increases by a factor of about 3.5 in the simulation frame. Strong electromagnetic fields are generated in the trailing shock and provide an emission site. These magnetic fields contribute to the electrons transverse deflection behind the shock. We calculate the radiation from deflected electrons in the turbulent magnetic fields. The properties of this radiation may be important for understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets in general, and supernova remnants.

  3. Shock Tube as an Impulsive Application Device

    Directory of Open Access Journals (Sweden)

    Soumya Ranjan Nanda

    2017-01-01

    Full Text Available Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

  4. Heat shock genes–integrating cell survival and death

    Indian Academy of Sciences (India)

    2007-03-22

    Mar 22, 2007 ... Heat shock induced gene expression and other cellular responses help limit the damage caused by stress and thus facilitate cellular recovery. Cellular damage also triggers apoptotic cell death through several pathways. This paper briefly reviews interactions of the major heat shock proteins with ...

  5. Development of immunoassay for the identification of cold shock ...

    African Journals Online (AJOL)

    Cold shock response in various organisms is induced by an abrupt downshift in temperature and leads to a dramatic increase in production of a homologous class of cold shock proteins. These proteins are essential for low temperature survival of bacteria. To identify CSP from diversified microflora, immunoassay was ...

  6. Modeling the Shock Hugoniot in Porous Materials

    Science.gov (United States)

    Cochrane, Kyle R.; Shulenburger, Luke; Mattsson, Thomas R.; Lane, J. Matthew D.; Weck, Philippe F.; Vogler, Tracy J.; Desjarlais, Michael P.

    2017-06-01

    Porous materials are present in many scenarios from planetary science to ICF. Understanding how porosity modifies the behavior of the shock Hugoniot in an equation of state is key to being able to predictively simulate experiments. For example, modeling shocks in under-dense iron oxide can aid in understanding planetary formation and silica aerogel can be used to approximate the shock response of deuterium. Simulating the shock response of porous materials presents a variety of theoretical challenges, but by combining ab initio calculations with a surface energy and porosity model, we are able to accurately represent the shock Hugoniot. Finally, we show that this new approach can be used to calculate the Hugoniot of porous materials using existing tabular equations of state. Sandia National Laboratories is a multi-mission laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  7. Collisionless electrostatic shock formation and ion acceleration in intense laser interactions with near critical density plasmas

    CERN Document Server

    Liu, M; Li, Y T; Yuan, D W; Chen, M; Mulser, P; Sheng, Z M; Murakami, M; Yu, L L; Zheng, X L; Zhang, J

    2016-01-01

    Laser-driven collisonless electrostatic shock formation and the subsequent ion acceleration have been studied in near critical density plasmas. Particle-in-cell simulations show that both the speed of laser-driven collisionless electrostatic shock and the energies of shock-accelerated ions can be greatly enhanced due to fast laser propagation in near critical density plasmas. However, a response time longer than tens of laser wave cycles is required before the shock formation in a near critical density plasma, in contrast to the quick shock formation in a highly overdense target. More important, we find that some ions can be reflected by the collisionless shock even if the electrostatic potential jump across the shock is smaller than the ion kinetic energy in the shock frame, which seems against the conventional ion-reflection condition. These anomalous ion reflections are attributed to the strongly time-oscillating electric field accompanying laser-driven collisionless shock in a near critical density plasma...

  8. Cathodic disbonding of organic coatings on submerged steel

    Energy Technology Data Exchange (ETDEWEB)

    Knudsen, Ole oeystein

    1998-12-31

    In offshore oil production, submerged steel structures are commonly protected by an organic coating in combination with cathodic protection. The main advantage is that the coating decreases the current demand for cathodic protection. But the coating degrades with time. This thesis studies one of the most important mechanisms for coating degradation in seawater, cathodic disbonding. Seven commercial coatings and two model coatings with various pigmentations have been studied. Parameter studies, microscopy and studies of free films were used in the mechanism investigations. Exposure to simulated North Sea conditions was used in the performance studies. The effect of aluminium and glass barrier pigments on cathodic disbonding was investigated. The mechanism for the effect of the aluminium pigments on cathodic disbonding was also investigated. The transport of charge and oxygen to the steel/coating interface during cathodic disbonding was studied for two epoxy coatings. Cathodic disbonding, blistering and current demand for cathodic protection was measured for nine commercial coatings for submerged steel structures, using the ASTM-G8 standard test and a long term test under simulated North Sea conditions. The relevance of the ASTM-G8 test as a prequalification test was evaluated. 171 refs., 40 figs., 6 tabs.

  9. Period Doubling in Bubbling from a Submerged Nozzle

    Science.gov (United States)

    Dennis, Jordan; Grace, Laura; Lehman, Susan

    The timing of bubbles rising from a nozzle submerged in a viscous solution was measured to examine the period-doubling route to chaos in this system. A narrow nozzle was submerged in a mixture of water and glycerin, and nitrogen was supplied to the nozzle at a varying flow rate. The bubbles were detected using a laser and photodiode system; when the bubbles rise through the laser beam, they scatter the light so that the signal at the photodiode decreases. The period between bubbles as well as the duration of each bubble (a function of bubble size and bubble velocity) was determined, and examined as the nitrogen flow rate increased, for solutions with five different concentrations of glycerin. Bubbles were also recorded visually using a high-speed camera. Within the flow rates tested, we observed a bifurcation of the period to period-2 behavior for all solutions tested, and a further bifurcation to period-4 for all solutions except pure glycerin. The solution viscosity affected both the onset of the bifurcation and the precise bubble behavior during the bifurcation. Unusually, a short period/long period pair of bubbles recurring at a regular interval was sometimes observed in the low flow regime which is typically period-1, an observation which requires further investigation. Research supported by NSF DMR 1560093.

  10. Magnetic imaging of a submerged Roman harbour, Caesarea Maritima, Israel

    Science.gov (United States)

    Boyce, J. I.; Reinhardt, E. G.; Raban, A.; Pozza, M. R.

    2003-04-01

    The harbour built by King Herod's engineers at Caesarea represented a major advance in Roman harbour construction that incorporated the use of large (390 m^3), form-filled hydraulic concrete blocks to build an extensive foundation for the harbour moles and breakwater barriers. Marine geophysical surveys were recently conducted across the submerged harbour in an attempt to map the configuration of the buried concrete foundation. A total of 107 line km of high-resolution marine magnetic surveys (nominal 15 m line separations) and bathymetry data were acquired over a 1 km^2 area of the submerged harbour using an Overhauser marine magnetometer, integrated DGPS and single-beam (200 KHz) echosounder. The feasibility of magnetic detection of the concrete was established before the survey by magnetic susceptibility testing of concrete core samples. All concrete samples contained appreciable amounts of fe-oxide-rich volcanic ash ('pozzolana') and showed uniformly high susceptibility values (k > 10^-^4 cgs) when compared to harbour bottom sediments and building stones (k construction of the harbour moles and quays.

  11. Methane oxidation associated to submerged brown-mosses buffers methane emissions from Siberian polygonal peatlands

    Science.gov (United States)

    Liebner, Susanne; Zeyer, Josef; Knoblauch, Christian

    2010-05-01

    Circumpolar peatlands store roughly 18 % of the globally stored carbon in soils [based on 1, 2]. Also, northern wetlands and tundra are a net source of methane (CH4), an effective greenhouse gas (GHG), with an estimated annual CH4 release of 7.2% [3] or 8.1% [4] of the global total CH4 emission. Although it is definite that Arctic tundra significantly contributes to the global methane emissions in general, regional variations in GHG fluxes are enormous. CH4 fluxes of polygonal tundra within the Siberian Lena Delta, for example, were reported to be low [5, 6], particularly at open water polygonal ponds and small lakes [7] which make up around 10 % of the delta's surface. Low methane emissions from polygonal ponds oppose that Arctic permafrost thaw ponds are generally known to emit large amounts of CH4 [8]. Combining tools of biogeochemistry and molecular microbiology, we identified sinks of CH4 in polygonal ponds from the Lena Delta that were not considered so far in GHG studies from Arctic wetlands. Pore water CH4 profiling in polygonal ponds on Samoylov, a small island in the central part of the Lena Delta, revealed a pronounced zone of CH4 oxidation near the vegetation surface in submerged layers of brown-mosses. Here, potential CH4 oxidation was an order of magnitude higher than in non-submerged mosses and in adjacent bulk soil. We could additionally show that this moss associated methane oxidation (MAMO) is hampered when exposure of light is prevented. Shading of plots with submerged Scorpidium scorpioides inhibited MAMO leading to higher CH4 concentrations and an increase in CH4 fluxes by a factor of ~13. Compared to non-submerged mosses, the submerged mosses also showed significantly lower δ13C values indicating that they use carbon dioxide derived from methane oxidation for photosynthesis. Applying stable isotope probing of DNA, type II methanotrophs were identified to be responsible for the oxidation of CH4 in the submerged Scorpidium scorpioides. Our

  12. Growth rate, protein:RNA ratio and stoichiometric homeostasis of submerged macrophytes under eutrophication stress

    OpenAIRE

    Xing W.; Shi Q.; Liu H.; Liu G.

    2016-01-01

    Growth rate hypothesis (GRH) and stoichiometric homeostasis of photoautotrophs have always been questioned. However, little is known about GRH and stoichiometric homeostasis of aquatic plants, especially submerged macrophytes. Therefore, we aim to test the GRH and explore stoichiometric homeostasis of four freshwater submerged macrophytes under eutrophication stress. At the single species level and the multi-species level, N:P ratios ...

  13. Multiple shocks, coping and welfare consequences: natural disasters and health shocks in the Indian Sundarbans.

    Science.gov (United States)

    Mazumdar, Sumit; Mazumdar, Papiya Guha; Kanjilal, Barun; Singh, Prashant Kumar

    2014-01-01

    Based on a household survey in Indian Sundarbans hit by tropical cyclone Aila in May 2009, this study tests for evidence and argues that health and climatic shocks are essentially linked forming a continuum and with exposure to a marginal one, coping mechanisms and welfare outcomes triggered in the response is significantly affected. The data for this study is based on a cross-sectional household survey carried out during June 2010. The survey was aimed to assess the impact of cyclone Aila on households and consequent coping mechanisms in three of the worst-affected blocks (a sub-district administrative unit), viz. Hingalganj, Gosaba and Patharpratima. The survey covered 809 individuals from 179 households, cross cutting age and gender. A separate module on health-seeking behaviour serves as the information source of health shocks defined as illness episodes (ambulatory or hospitalized) experienced by household members. Finding reveals that over half of the households (54%) consider that Aila has dealt a high, damaging impact on their household assets. Result further shows deterioration of health status in the period following the incidence of Aila. Finding suggests having suffered multiple shocks increases the number of adverse welfare outcomes by 55%. Whereas, suffering either from the climatic shock (33%) or the health shock (25%) alone increases such risks by a much lesser extent. The multiple-shock households face a significantly higher degree of difficulty to finance expenses arising out of health shocks, as opposed to their counterparts facing only the health shock. Further, these households are more likely to finance the expenses through informal loans and credit from acquaintances or moneylenders. This paper presented empirical evidence on how natural and health shocks mutually reinforce their resultant impact, making coping increasingly difficult and present significant risks of welfare loss, having short as well as long-run development manifestations.

  14. Evidence of shoreline shift on the northern Saurashtra coast: Study based on the submerged temple complex at Pindara

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh

    . It is difficult to assign a particular reason for the submergence of the temple in discussion, however minor sea level rise and seismic activity might have played a vital role in submergence of the temple complex....

  15. Submerged beach ridge lineation and associated sedentary fauna in the innershelf of Gopalpur Coast, Orissa, Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, K.M.; Murthy, K.S.R.; Reddy, N.P.C.; Subrahmanyam, A.S.; Lakshminarayana, S.; Rao, M.M.M.; Sarma, K.V.L.N.S.; Premkumar, M.K.; Sree, A.; Bapuji, M.

    . (e - mail: kmrao@kadali.nio.org) RESEARCH COMMUNICATIONS CURRENT SCIENCE, VOL. 81, NO. 7, 10 OCTOBER 2001 829 mic profiling to locate the submerged roc k outcrops. Though the submerged topographic features were r e por - ted by some...

  16. EAARL-B Submerged Topography–Saint Croix, U.S. Virgin Islands, 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A submerged topography Digital Elevation Model (DEM) mosaic for a portion of the submerged environs of Saint Croix, U.S. Virgin Islands, was produced from remotely...

  17. Dual neuroprotective pathways of a pro-electrophilic compound via HSF-1-activated heat-shock proteins and Nrf2-activated phase 2 antioxidant response enzymes.

    Science.gov (United States)

    Satoh, Takumi; Rezaie, Tayebeh; Seki, Masaaki; Sunico, Carmen R; Tabuchi, Takahito; Kitagawa, Tomomi; Yanagitai, Mika; Senzaki, Mutsumi; Kosegawa, Chihiro; Taira, Hideharu; McKercher, Scott R; Hoffman, Jennifer K; Roth, Gregory P; Lipton, Stuart A

    2011-11-01

    Activation of the Keap1/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and consequent induction of phase 2 antioxidant enzymes is known to afford neuroprotection. Here, we present a series of novel electrophilic compounds that protect neurons via this pathway. Natural products, such as carnosic acid (CA), are present in high amounts in the herbs rosemary and sage as ortho-dihydroquinones, and have attracted particular attention because they are converted by oxidative stress to their active form (ortho-quinone species) that stimulate the Keap1/Nrf2 transcriptional pathway. Once activated, this pathway leads to the production of a series of antioxidant phase 2 enzymes. Thus, such dihydroquinones function as redox-activated 'pro-electrophiles'. Here, we explored the concept that related para-dihydroquinones represent even more effective bioactive pro-electrophiles for the induction of phase 2 enzymes without producing toxic side effects. We synthesized several novel para-hydroquinone-type pro-electrophilic compounds (designated D1 and D2) to analyze their protective mechanism. DNA microarray, PCR, and western blot analyses showed that compound D1 induced expression of heat-shock proteins (HSPs), including HSP70, HSP27, and DnaJ, in addition to phase 2 enzymes such as hemeoxygenase-1 (HO-1), NADP(H) quinine-oxidoreductase1, and the Na(+)-independent cystine/glutamate exchanger (xCT). Treatment with D1 resulted in activation of Nrf2 and heat-shock transcription factor-1 (HSF-1) transcriptional elements, thus inducing phase 2 enzymes and HSPs, respectively. In this manner, D1 protected neuronal cells from both oxidative and endoplasmic reticulum (ER)-related stress. Additionally, D1 suppressed induction of 78 kDa glucose-regulated protein (GRP78), an ER chaperone protein, and inhibited hyperoxidation of peroxiredoxin 2 (PRX2), a molecule that is in its reduced state can protect from oxidative stress. These results suggest that D1 is a novel pro

  18. The optimization of Marasmius androsaceus submerged fermentation conditions in five-liter fermentor.

    Science.gov (United States)

    Meng, Fanxin; Xing, Gaoyang; Li, Yutong; Song, Jia; Wang, Yanzhen; Meng, Qingfan; Lu, Jiahui; Zhou, Yulin; Liu, Yan; Wang, Di; Teng, Lirong

    2016-01-01

    Using desirability function, four indexes including mycelium dry weight, intracellular polysaccharide, adenosine and mannitol yield were uniformed into one expected value (Da) which further served as the assessment criteria. In our present study, Plackett-Burman design was applied to evaluate the effects of eight variables including initial pH, rotating speed, culture temperature, inoculum size, ventilation volume, culture time, inoculum age and loading volume on Da value during Marasmius androsaceus submerged fermentation via a five-liter fermentor. Culture time, initial pH and rotating speed were found to influence Da value significantly and were further optimized by Box-Behnken design. Results obtained from Box-Behnken design were analyzed by both response surface regression (Design-Expert.V8.0.6.1 software) and artificial neural network combining the genetic algorithm method (Matlab2012a software). After comparison, the optimum M. androsaceus submerged fermentation conditions via a five-liter fermentor were obtained as follows: initial pH of 6.14, rotating speed of 289.3 rpm, culture time of 6.285 days, culture temperature of 26 °C, inoculum size of 5%, ventilation volume of 200 L/h, inoculum age of 4 days, and loading volume of 3.5 L/5 L. The predicted Da value of the optimum model was 0.4884 and the average experimental Da value was 0.4760. The model possesses well fitness and predictive ability.

  19. THE STUDY ON THE DURABILITY OF SUBMERGED STRUCTURE DISPLACEMENT DUE TO CONCRETE FAILURE

    Directory of Open Access Journals (Sweden)

    M. Mohd

    2016-09-01

    Full Text Available Concrete structures that exposed to marine environments are subjected to multiple deterioration mechanisms. An overview of the existing technology for submerged concrete, pressure resistant, concrete structures which related such as cracks, debonds, and delamination are discussed. Basic knowledge related to drowning durability such as submerged concrete structures in the maritime environment are the durability of a concrete and the ability to resist to weathering, chemical attack, abrasion or other deterioration processes. The measuring techniques and instrumentation for geometrical monitoring of submerged structural displacements have traditionally been categorized into two groups according to the two main groups, namely as geodetic surveying and geotechnical structural measurements of local displacements. This paper aims to study the durability of submerged concrete displacement and harmful effects of submerged concrete structures.

  20. Macroeconomic shocks and firms' labor adjustment

    DEFF Research Database (Denmark)

    Eriksson, Tor

    2013-01-01

    This article discusses some recent research which aims at producing evidence on how firms adjust their employment in response to output shocks using micro-level data and with a particular focus on the relationship between worker and job flows. The evidence presented is mainly based on Danish data...

  1. MONETARY SHOCKS AND REAL EXCHANGE RATE FLUCTUATIONS IN CEE COUNTRIES

    Directory of Open Access Journals (Sweden)

    Nataša Erjavec

    2012-12-01

    Full Text Available The aim of this paper is to investigate the role of the exchange rate regime in absorbing macroeconomic shocks for a group of Central and East European countries (CEE. Whether the flexible exchange rate regime is beneficial for an economy depends on the capacity of the exchange rate to act as a shock absorber. An appropriate framework for assessing the role of the exchange rate is a structural vector autoregressive (SVAR model. Impact of two types of macroeconomic shocks is estimated: nominal and real. The shocks are identified on the basis of Blanchard-Quah long run identification scheme which means that the restrictions are imposed on the long run responses while the short run dynamics is kept unrestricted. The importance of nominal and real shocks is assessed using the variance decomposition and the impulse response functions.

  2. Bioactive Coating with Two-Layer Hierarchy of Relief Obtained by Sol-Gel Method with Shock Drying and Osteoblast Response of Its Structure

    Directory of Open Access Journals (Sweden)

    Elena G. Zemtsova

    2017-10-01

    Full Text Available In this work, we analyze the efficiency of the modification of the implant surface. This modification was reached by the formation of a two-level relief hierarchy by means of a sol-gel approach that included dip coating with subsequent shock drying. Using this method, we fabricated a nanoporous layer with micron-sized defects on the nanotitanium surface. The present work continues an earlier study by our group, wherein the effect of osteoblast-like cell adhesion acceleration was found. In the present paper, we give the results of more detailed evaluation of coating efficiency. Specifically, cytological analysis was performed that included the study of the marker levels of osteoblast-like cell differentiation. We found a significant increase in the activity of alkaline phosphatase at the initial incubation stage. This is very important for implantation, since such an effect assists the decrease in the induction time of implant engraftment. Moreover, osteopontin expression remains high for long expositions. This indicates a prolonged osteogenic effect in the coating. The results suggest the acceleration of the pre-implant area mineralization and, correspondingly, the potential use of the developed coatings for bone implantation.

  3. An Analytical Solution for Dynamic Response of Water Barrier Subjected to Strong Shock Waves Caused by an Underwater Explosion to Dams

    Directory of Open Access Journals (Sweden)

    Lu Lu

    2017-08-01

    Full Text Available Shock waves arriving at a dam site are close to plane waves when the center of an underwater explosion is far from the dam site. In general, the wave pressure is calculated with COLE empirical formula. The COLE formula is a negative exponential function with respect to time. In this paper, a new analytical solution algorithm is proposed, which does not require the use of step-by-step time integration. In Comparison with the step-by-step time integration, the proposed algorithm requires relatively less calculation and avoids high-frequency oscillation. Furthermore, the vertical upstream surface and the sloping upstream surface in two types of the dams are analyzed in this paper. The research results indicate that the analytical solution can be applied for a dam with a vertical upstream surface. However, because the upstream face of a dam is inclined, the analytical solution can be obtained only for dams that are at lower height. Whenever the height of a dam is higher, then no analytical solution can be obtained, and only the use of step-by-step time integration can obtain a solution.

  4. Optimal monetary policy and oil price shocks

    Science.gov (United States)

    Kormilitsina, Anna

    This dissertation is comprised of two chapters. In the first chapter, I investigate the role of systematic U.S. monetary policy in the presence of oil price shocks. The second chapter is devoted to studying different approaches to modeling energy demand. In an influential paper, Bernanke, Gertler, and Watson (1997) and (2004) argue that systematic monetary policy exacerbated the recessions the U.S. economy experienced in the aftermath of post World War II oil price shocks. In the first chapter of this dissertation, I critically evaluate this claim in the context of an estimated medium-scale model of the U.S. business cycle. Specifically, I solve for the Ramsey optimal monetary policy in the medium-scale dynamic stochastic general equilibrium model (henceforth DSGE) of Schmitt-Grohe and Uribe (2005). To model the demand for oil, I use the approach of Finn (2000). According to this approach, the utilization of capital services requires oil usage. In the related literature on the macroeconomic effects of oil price shocks, it is common to calibrate structural parameters of the model. In contrast to this literature, I estimate the parameters of my DSGE model. The estimation strategy involves matching the impulse responses from the theoretical model to responses predicted by an empirical model. For estimation, I use the alternative to the classical Laplace type estimator proposed by Chernozhukov and Hong (2003). To obtain the empirical impulse responses, I identify an oil price shock in a structural VAR (SVAR) model of the U.S. business cycle. The SVAR model predicts that, in response to an oil price increase, GDP, investment, hours, capital utilization, and the real wage fall, while the nominal interest rate and inflation rise. These findings are economically intuitive and in line with the existing empirical evidence. Comparing the actual and the Ramsey optimal monetary policy response to an oil price shock, I find that the optimal policy allows for more inflation, a

  5. Biophoton emission induced by heat shock.

    Directory of Open Access Journals (Sweden)

    Katsuhiro Kobayashi

    Full Text Available Ultraweak biophoton emission originates from the generation of reactive oxygen species (ROS that are produced in mitochondria as by-products of cellular respiration. In healthy cells, the concentration of ROS is minimized by a system of biological antioxidants. However, heat shock changes the equilibrium between oxidative stress and antioxidant activity, that is, a rapid rise in temperature induces biophoton emission from ROS. Although the rate and intensity of biophoton emission was observed to increase in response to elevated temperatures, pretreatment at lower high temperatures inhibited photon emission at higher temperatures. Biophoton measurements are useful for observing and evaluating heat shock.

  6. Leaf gas films contribute to rice (Oryza sativa) submergence tolerance during saline floods

    DEFF Research Database (Denmark)

    Herzog, Max; Konnerup, Dennis; Pedersen, Ole

    2018-01-01

    Floods and salinization of agricultural land adversely impact global rice production. We investigated whether gas films on leaves of submerged rice delay salt entry during saline submergence. Two-week-old plants with leaf gas films (+GF) or with gas films experimentally removed (-GF) were submerg...

  7. Shock Detector for SURF model

    Energy Technology Data Exchange (ETDEWEB)

    Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-11

    SURF and its extension SURFplus are reactive burn models aimed at shock initiation and propagation of detonation waves in high explosives. A distinctive feature of these models is that the burn rate depends on the lead shock pressure. A key part of the models is an algorithm to detect the lead shock. Typically, shock capturing hydro algorithms have small oscillations behind a shock. Here we investigate how well the shock detection algorithm works for a nearly steady propagating detonation wave in one-dimension using the Eulerian xRage code.

  8. Performance Evaluation of Submerged Floating Tunnel Subjected to Hydrodynamic and Seismic Excitations

    Directory of Open Access Journals (Sweden)

    Naik Muhammad

    2017-10-01

    Full Text Available Submerged floating tunnels (SFTs are innovative structural solutions to waterway crossings, such as sea-straits, fjords and lakes. As the width and depth of straits increase, the conventional structures such as cable-supported bridges, underground tunnels or immersed tunnels become uneconomical alternatives. For the realization of SFT, the structural response under extreme environmental conditions needs to be evaluated properly. This study evaluates the displacements and internal forces of SFT under hydrodynamic and three-dimensional seismic excitations to check the global performance of an SFT in order to conclude on the optimum design. The formulations incorporate modeling of ocean waves, currents and mooring cables. The SFT responses were evaluated using three different mooring cable arrangements to determine the stability of the mooring configuration, and the most promising configuration was then used for further investigations. A comparison of static, hydrodynamic and seismic response envelope curves of the SFT is provided to determine the dominant structural response. The study produces useful conclusions regarding the structural behavior of the SFT using a three-dimensional numerical model.

  9. Lupus and autoimmune shock: Use of intravenous gammaglobulin. Case report and proposal for a new designation

    OpenAIRE

    Hernández Bautista Victor Manuel; Stamatelos Albarrán Daniela; Vázquez García Rubén Ernesto

    2014-01-01

    Shock is a state of hypotension and hypoperfusion which in turn leads to cellular dysfunction, neuroendocrine responses, inflam- matory mediator release, and alterations of the microcirculation. There are various ways of classifying tissue perfusion failure. A simple method is dividing them into a distributive category, such as septic or anaphylactic shock, and a non-distributive category such as hypovolemic shock. There is extensive knowledge on septic shock; the interaction between bacteria...

  10. Physics of Collisionless Shocks Space Plasma Shock Waves

    CERN Document Server

    Balogh, André

    2013-01-01

    The present book provides a contemporary systematic treatment of shock waves in high-temperature collisionless plasmas as are encountered in near Earth space and in Astrophysics. It consists of two parts. Part I develops the complete theory of shocks in dilute hot plasmas under the assumption of absence of collisions among the charged particles when the interaction is mediated solely by the self-consistent electromagnetic fields. Such shocks are naturally magnetised implying that the magnetic field plays an important role in their evolution and dynamics. This part treats both subcritical shocks, which dissipate flow energy by generating anomalous resistance or viscosity, and supercritical shocks. The main emphasis is, however, on super-critical shocks where the anomalous dissipation is insufficient to retard the upstream flow. These shocks, depending on the direction of the upstream magnetic field, are distinguished as quasi-perpendicular and quasi-parallel shocks which exhibit different behaviours, reflecti...

  11. Passive Shock Isolation Utilising Dry Friction

    Directory of Open Access Journals (Sweden)

    Mohd Ikmal Ismail

    2017-01-01

    Full Text Available A novel shock isolation strategy for base excited system is presented by introducing a two-degree-of-freedom model with passive friction, where the friction is applied to an attached mass instead of directly to the primary isolated mass. The model is evaluated against the benchmark case of single-degree-of-freedom system with friction applied directly to the primary isolated mass. The performances of the models are compared in terms of the maximum displacement response and the acceleration during the application of the shock input for the case when the shock input duration is approximately equal to the natural period of the system (amplification region. From the results, the two-degree-of-freedom model can produce both maximum displacement reduction and smoother acceleration at the point of motion transition. An experimental rig was built to validate the theoretical results against the experimental results; it is found that the experimental results closely match the theoretical predictions.

  12. Shock Scattering in a Multiphase Flow Model

    Energy Technology Data Exchange (ETDEWEB)

    Klem, D

    2003-04-08

    Multiphase flow models have been proposed for use in situations which have combined Rayleigh-Taylor (RTI) and Richtmyer-Meshkov (RMI) instabilities. Such an approach work poorly for the case of a heavy to light shock incidence on a developed interface. The physical original of this difficulty is traced to an inadequate model of the interfacial pressure term as it appears in the momentum and turbulence kinetic energy equations. Constraints on the form of a better model from a variety of sources are considered. In this context it is observed that a new constraint on closures arises. This occurs because of the discontinuity within the shock responsible for the RMI. The proposed model (Shock Scattering) is shown to give useful results.

  13. Shock wave science and technology reference library

    CERN Document Server

    2009-01-01

    This book is the second of several volumes on solids in the Shock Wave Science and Technology Reference Library. These volumes are primarily concerned with high-pressure shock waves in solid media, including detonation and high-velocity impact and penetration events. Of the four extensive chapters in this volume, the first two describe the reactive behavior of condensed phase explosives, - Condensed-Phase Explosives: Shock Initiation and Detonation Phenomena (SA Sheffield and R Engelke) - First Principles Molecular Simulations of Energetic Materials at High-Pressures (F Zhang, S Alavi, and TK Woo), and the remaining two discuss the inert, mechanical response of solid materials. - Combined Compression and Shear Plane Waves (ZP Tang and JB Aidun), and - Dynamic Fragmentation of Solids (D Grady). All chapters are each self-contained, and can be read independently of each other. They offer a timely reference, for beginners as well as professional scientists and engineers, on the foundations of detonation phenomen...

  14. Pathophysiological roles of peroxynitrite in circulatory shock.

    Science.gov (United States)

    Szabó, Csaba; Módis, Katalin

    2010-09-01

    Peroxynitrite is a reactive oxidant produced from nitric oxide and superoxide, which reacts with proteins, lipids, and DNA, and promotes cytotoxic and proinflammatory responses. Here, we overview the role of peroxynitrite in various forms of circulatory shock. Immunohistochemical and biochemical evidences demonstrate the production of peroxynitrite in various experimental models of endotoxic and hemorrhagic shock both in rodents and in large animals. In addition, biological markers of peroxynitrite have been identified in human tissues after circulatory shock. Peroxynitrite can initiate toxic oxidative reactions in vitro and in vivo. Initiation of lipid peroxidation, direct inhibition of mitochondrial respiratory chain enzymes, inactivation of glyceraldehyde-3-phosphate dehydrogenase, inhibition of membrane Na+/K+ ATPase activity, inactivation of membrane sodium channels, and other oxidative protein modifications contribute to the cytotoxic effect of peroxynitrite. In addition, peroxynitrite is a potent trigger of DNA strand breakage, with subsequent activation of the nuclear enzyme poly(ADP-ribose) polymerase, which promotes cellular energetic collapse and cellular necrosis. Additional actions of peroxynitrite that contribute to the pathogenesis of shock include inactivation of catecholamines and catecholamine receptors (leading to vascular failure) and endothelial and epithelial injury (leading to endothelial and epithelial hyperpermeability and barrier dysfunction), as well as myocyte injury (contributing to loss of cardiac contractile function). Neutralization of peroxynitrite with potent peroxynitrite decomposition catalysts provides cytoprotective and beneficial effects in rodent and large-animal models of circulatory shock.

  15. Culture shock and travelers.

    Science.gov (United States)

    Stewart, L; Leggat, P A

    1998-06-01

    As travel has become easier and more affordable, the number of people traveling has risen sharply. People travel for many and varied reasons, from the business person on an overseas assignment to backpackers seeking new and exotic destinations. Others may take up residence in different regions, states or countries for family, business or political reasons. Other people are fleeing religious or political persecution. Wherever they go and for whatever reason they go, people take their culture with them. Culture, like language, is acquired innately in early childhood and is then reinforced through formal and complex informal social education into adulthood. Culture provides a framework for interpersonal and social interactions. Therefore, the contact with a new culture is often not the exciting or pleasurable experience anticipated. When immersed in a different culture, people no longer know how to act when faced with disparate value systems. Contact with the unfamiliar culture can lead to anxiety, stress, mental illness and, in extreme cases, physical illness and suicide. "Culture shock" is a term coined by the anthropologist Oberg. It is the shock of the new. It implies that the experience of the new culture is an unpleasant surprise or shock, partly because it is unexpected and partly because it can lead to a negative evaluation of one's own culture. It is also known as cross-cultural adjustment, being that period of anxiety and confusion experienced when entering a new culture. It affects people intellectually, emotionally, behaviorally and physically and is characterized by symptoms of psychological distress. Culture shock affects both adults and children. In travelers or workers who have prolonged sojourns in foreign countries, culture shock may occur not only as they enter the new culture, but also may occur on their return to their original culture. Children may also experience readjustment problems after returning from leading sheltered lives in expatriate

  16. Histological change and heat shock protein 70 expression in different tissues of Japanese flounder Paralichthys olivaceus in response to elevated temperature

    Science.gov (United States)

    Liu, Yifan; Ma, Daoyuan; Xiao, Zhizhong; Xu, Shihong; Wang, Yanfeng; Wang, Yufu; Xiao, Yongshuang; Song, Zongcheng; Teng, Zhaojun; Liu, Qinghua; Li, Jun

    2015-01-01

    High temperature influences the homeostasis of fish. We investigated the effects of elevated temperature on tissues of Japanese flounder ( Paralichthys olivaceus) by analyzing the histology and heat shock protein 70 ( hsp70) expression of fish reared in warm conditions. In this study, temperature was increased at 1±0.5°C/day starting at 24±0.5°C, and was kept at that temperature for 5 days before the next rise. After raising temperature at the rate up to 32±0.5°C, tissue samples from midgut, spleen, stomach, liver, muscle, gill, heart, trunk kidney and brain were collected for histological analysis and mRNA assay. Almost all the tissues showed changes in morphological structure and hsp70 level at 32±0.5°C. Histological assessment of the tissues indicated that the gill had the most serious damage, including highly severe epithelial lifting and edema, curved tips and hyperemia at the ending of the lamellars, desquamation and necrosis. The next most severe damage was found in liver and kidney. The hsp70 levels in all the tissues first increased and then decreased. The gut, stomach, muscle, heart, and brain had the highest expressions in 6 h, whereas the spleen, liver, gill and kidney had the highest expressions in 2 h. Therefore, tissues with the most significant lesions (especially gill and liver) responded much earlier (2 h) in hsp70 expression than other tissues, and these tissues demonstrated the most marked histological disruption and elevated mRNA levels, making them ideal candidates for further studies on the thermal physiology of this species.

  17. Deep sequencing analyses expands the Pseudomonas aeruginosa AmpR regulon to include small RNA-mediated regulation of iron acquisition, heat shock and oxidative stress response

    Science.gov (United States)

    Balasubramanian, Deepak; Kumari, Hansi; Jaric, Melita; Fernandez, Mitch; Turner, Keith H.; Dove, Simon L.; Narasimhan, Giri; Lory, Stephen; Mathee, Kalai

    2014-01-01

    Pathogenicity of Pseudomonas aeruginosa, a major cause of many acute and chronic human infections, is determined by tightly regulated expression of multiple virulence factors. Quorum sensing (QS) controls expression of many of these pathogenic determinants. Previous microarray studies have shown that the AmpC β-lactamase regulator AmpR, a member of the LysR family of transcription factors, also controls non-β-lactam resistance and multiple virulence mechanisms. Using RNA-Seq and complementary assays, this study further expands the AmpR regulon to include diverse processes such as oxidative stress, heat shock and iron uptake. Importantly, AmpR affects many of these phenotypes, in part, by regulating expression of non-coding RNAs such as rgP32, asRgsA, asPrrF1 and rgRsmZ. AmpR positively regulates expression of the major QS regulators LasR, RhlR and MvfR, and genes of the Pseudomonas quinolone system. Chromatin immunoprecipitation (ChIP)-Seq and ChIP–quantitative real-time polymerase chain reaction studies show that AmpR binds to the ampC promoter both in the absence and presence of β-lactams. In addition, AmpR directly binds the lasR promoter, encoding the QS master regulator. Comparison of the AmpR-binding sequences from the transcriptome and ChIP-Seq analyses identified an AT-rich consensus-binding motif. This study further attests to the role of AmpR in regulating virulence and physiological processes in P. aeruginosa. PMID:24157832

  18. Thermal Shock-resistant Cement

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Pyatina, T.; Gill, S.

    2012-02-01

    We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved

  19. Critical Assessment of Temperature Distribution in Submerged Arc Welding Process

    Directory of Open Access Journals (Sweden)

    Vineet Negi

    2013-01-01

    Full Text Available Temperature distribution during any welding process holds the key for understanding and predicting several important welding attributes like heat affected zone, microstructure of the weld, residual stress, and distortion during welding. The accuracy of the analytical approaches for modeling temperature distribution during welding has been constrained by oversimplified assumptions regarding boundary conditions and material properties. In this paper, an attempt has been made to model the temperature distribution during submerged arc welding process using finite element modeling technique implemented in ANSYS v12. In the present analysis, heat source is assumed to be double-ellipsoidal with Gaussian volumetric heat generation. Furthermore, variation of material properties with temperature and both convective and radiant heat loss boundary condition have been considered. The predicted temperature distribution is then validated against the experimental results obtained by thermal imaging of the welded plate, and they are found to be in a good agreement.

  20. Arc characteristics of submerged arc welding with stainless steel wire

    Science.gov (United States)

    Li, Ke; Wu, Zhi-sheng; Liu, Cui-rong; Chen, Feng-hua

    2014-08-01

    The arc characteristics of submerged arc welding (SAW) with stainless steel wire were studied by using Analysator Hannover (AH). The tests were carried out under the same preset arc voltage combined with different welding currents. By comparing the probability density distribution (PDD) curves of arc voltage and welding current, the changes were analyzed, the metal transfer mode in SAW was deduced, and the characteristics of a stable arc were summarized. The analysis results show that, with an increase of welding parameters, the short-circuiting peak in the PDD curves of arc voltage decreases gradually until it disappears, and the dominant metal transfer mode changes from flux-wall guided transfer to projected transfer and then to streaming transfer. Moreover, when the PDD curves of arc voltage are both unimodal and generally symmetrical, the greater the peak probability and the smaller the peak span, the more stable the arc becomes.