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Sample records for hypertrophic stratified lake

  1. Methane metabolism in a stratified boreal lake

    NASA Astrophysics Data System (ADS)

    Nykänen, Hannu; Peura, Sari; Kankaala, Paula; Jones, Roger

    2013-04-01

    Stratified lakes, typical of the boreal zone, are naturally anoxic from their bottoms. In these lakes methanogenesis can account for up to half of organic matter degradation. However, a major part of the methane (CH4) is oxidized in the water column before reaching the atmosphere. Since methanotrophs use CH4 as their sole carbon and energy source, much CH4-derived carbon is incorporated into their biomass. Microbially produced CH4 has strongly negative δ13C compared to other carbon forms in ecosystems, making it possible to follow its route in food webs. However, only a few studies have estimated the amount of this microbial biomass or its carbon stable isotopic composition due to difficulties in separating it from other biomass or from other carbon forms in the water column. We estimated methanotrophic biomass from measured CH4 oxidation, and δ13C of the biomass from measured δ13C values of CH4, DIC, POM and DOC. An estimate of the fraction of methanotrophs in total microbial biomass is derived from bacterial community composition measurements. The study was made in, Alinen Mustajärvi, a small (area 0.75 ha, maximum depth 6.5 m, mean depth 4.2 m,), oligotrophic, mesohumic headwater lake located in boreal coniferous forest in southern Finland. CH4 and DIC concentrations and their δ13C were measured over the deepest point of the lake at 1 m intervals. 13C of DOM and POM were analyzed from composite samples from epi-, meta-, and hypolimnion. Evasion of CH4 and carbon dioxide from the lake surface to the atmosphere was estimated with boundary layer diffusion equations. CH4oxidation was estimated by comparing differences between observed concentrations and CH4potentially transported by turbulent diffusion between different vertical layers in the lake and also by actual methanotrophy measurements and from vertical differences in δ13C-CH4. The estimate of CH4 production was based on the sum of oxidized and released CH4. Molecular microbiology methods were used to

  2. [Phylogenetic diversity of bacteria in soda lake stratified sediments].

    PubMed

    Tourova, T P; Grechnikova, M A; Kuznetsov, V V; Sorokin, D Yu

    2014-01-01

    Various previously developed techniques for DNA extraction from the samples with complex physicochemical structure (soils, silts, and sediments) and modifications of these techniques developed in the present work were tested. Their usability for DNA extraction from the sediments of the Kulunda Steppe hypersaline soda lakes was assessed, and the most efficient procedure for indirect (two-stage) DNA extraction was proposed. Almost complete separation of the cell fraction was shown, as well as the inefficiency of nested PCR for analysis of the clone libraries obtained from washed sediments by amplification of the 16S rRNA gene fragments. Analysis of the clone library obtained from the cell fractions of stratified sediments (upper, medium, and lower layers) revealed that in the sediments of Lake Gorchina-3 most eubacterial phylotypes belonged to the class Clostridia, phylum Firmicutes. They were probably specific for this habitatand formed a new, presently unknown high-rank taxon. The data obtained revealed no pronounced stratification of the spe- cies diversity of the eubacterial component of the microbial community inhabiting the sediments (0-20 cm) in the inshore zone of Lake Gorchina-3.

  3. Heterotrophic bacterioplankton control on organic and inorganic carbon cycle in stratified and non-stratified lakes of NW Russia

    NASA Astrophysics Data System (ADS)

    Shirokova, Liudmila; Vorobjeva, Taissia; Zabelina, Svetlana; Moreva, Olga; Klimov, Sergey; Shorina, Natalja; Chupakov, Artem; Pokrovsky, Oleg; Audry, Stephan; Viers, Jerome

    2010-05-01

    Lakes of boreal zone regulate the fate of dissolved carbon, nutrients and trace metals during their transport from the watershed to the ocean. Study of primary production - mineralization processes in the context of carbon biogeochemical cycle allows determination of the rate and mechanisms of phytoplankton biomass production and its degradation via aquatic heterotrophic bacteria. In particular, comparative study of vertical distribution of Dissolved Organic Carbon (DOC) in stratified and non-stratified lakes allows establishing the link between biological and chemical aspects of the carbon cycle which, in turns, determines an environmental stability and recovering potential of the entire ecosystem. In order to better understand the biogeochemical mechanisms that control dissolved organic and inorganic carbon migration in surface boreal waters, we studied in 2007-2009 two strongly stratified lakes (15-20 m deep) and two shallow lakes (2-4 m deep) in the Arkhangelsk region (NW Russia, White Sea basin). We conducted natural experiments of the lake water incubation for measurements of the intensity of production/mineralization processes and we determined vertical concentration of DOC during four basic hydrological seasons (winter and summer stratification, and spring and autumn lake overturn). Our seasonal studies of production/mineralization processes demonstrated high intensity of organic matter formation during summer period and significant retard of these processes during winter stagnation. During spring period, there is a strong increase of bacterial destruction of the allochtonous organic matter that is being delivered to the lake via terrigenous input. During autumn overturn, there is a decrease of the activity of phytoplankton, and the degradation of dead biomass by active bacterial community. Organic matter destruction processes are the most active in Svyatoe lake, whereas in the Beloe lake, the rate of organic matter production is significantly higher than

  4. Calcium, magnesium and strontium cycling in stratified, hardwater lakes: Lake Kinneret (Sea of Galilee), Israel

    NASA Astrophysics Data System (ADS)

    Katz, Amitai; Nishri, Ami

    2013-03-01

    In stratified hardwater lakes, calcite crystallization in the epilimnion and partial dissolution in the hypolimnion play important roles in the cycling of Ca2+ in the water column. Mg2+ and Sr2+ coprecipitate with this mineral, to be released together with Ca2+ upon its dissolution. Here, we focus on Lake Kinneret (Sea of Galilee, Israel), a stratified, warm, hardwater lake, searching for an interpretable, high resolution picture of the processes that drive Ca2+, Mg2+ and Sr2+cycling in this and similar lakes elsewhere. In total, 1428 water samples were collected from the lake, and another 81 samples were collected from the Jordan River and two small streams discharging into it, covering a full monomictic cycle from December 2001 through March 2003. Particulate material was retrieved from sediment traps in the hypolimnion. The water samples were analyzed for Na+, K+, Mg2+, Ca2+, Sr2+, Cl-, SO42-, HCO3- and Br-, and the trapped particulates were examined under SEM and analyzed for their Ca, Mg, and Sr content. Individual calcite crystals within the particulate material underwent LA-ICP-MS analysis for Ca, Mg, and Sr. Downward transport of Ca2+ involves crystallization of calcite in the epilimnion, followed by its settling through the water column, followed by its partial dissolution in the hypolimnion. Magnesium and Sr2+ follow Ca2+ by coprecipitation in calcite and are released upon its dissolution in the hypolimnion. Upward cycling of the three solutes occurs through an admixture of the hypolimnetic water into the epilimnion during thermocline deepening, terminated by overturn of the lake. Removal rates of Mg2+ and Sr2+ from the lake, relative to that of Ca2+, and the water-calcite distribution coefficients, DMg and DSr, were calculated from the analyses using: (1) epilimnion water and 'bulk' particulates; (2) epilimnion water only; and (3) epilimnion water and calcite crystals in the particulates. The DSr values obtained were internally consistent (0.194 ± 5

  5. Rising CO2 Levels Will Intensify Phytoplankton Blooms in Eutrophic and Hypertrophic Lakes

    PubMed Central

    Verspagen, Jolanda M. H.; Van de Waal, Dedmer B.; Finke, Jan F.; Visser, Petra M.; Van Donk, Ellen; Huisman, Jef

    2014-01-01

    Harmful algal blooms threaten the water quality of many eutrophic and hypertrophic lakes and cause severe ecological and economic damage worldwide. Dense blooms often deplete the dissolved CO2 concentration and raise pH. Yet, quantitative prediction of the feedbacks between phytoplankton growth, CO2 drawdown and the inorganic carbon chemistry of aquatic ecosystems has received surprisingly little attention. Here, we develop a mathematical model to predict dynamic changes in dissolved inorganic carbon (DIC), pH and alkalinity during phytoplankton bloom development. We tested the model in chemostat experiments with the freshwater cyanobacterium Microcystis aeruginosa at different CO2 levels. The experiments showed that dense blooms sequestered large amounts of atmospheric CO2, not only by their own biomass production but also by inducing a high pH and alkalinity that enhanced the capacity for DIC storage in the system. We used the model to explore how phytoplankton blooms of eutrophic waters will respond to rising CO2 levels. The model predicts that (1) dense phytoplankton blooms in low- and moderately alkaline waters can deplete the dissolved CO2 concentration to limiting levels and raise the pH over a relatively wide range of atmospheric CO2 conditions, (2) rising atmospheric CO2 levels will enhance phytoplankton blooms in low- and moderately alkaline waters with high nutrient loads, and (3) above some threshold, rising atmospheric CO2 will alleviate phytoplankton blooms from carbon limitation, resulting in less intense CO2 depletion and a lesser increase in pH. Sensitivity analysis indicated that the model predictions were qualitatively robust. Quantitatively, the predictions were sensitive to variation in lake depth, DIC input and CO2 gas transfer across the air-water interface, but relatively robust to variation in the carbon uptake mechanisms of phytoplankton. In total, these findings warn that rising CO2 levels may result in a marked intensification of

  6. Rising CO2 levels will intensify phytoplankton blooms in eutrophic and hypertrophic lakes.

    PubMed

    Verspagen, Jolanda M H; Van de Waal, Dedmer B; Finke, Jan F; Visser, Petra M; Van Donk, Ellen; Huisman, Jef

    2014-01-01

    Harmful algal blooms threaten the water quality of many eutrophic and hypertrophic lakes and cause severe ecological and economic damage worldwide. Dense blooms often deplete the dissolved CO2 concentration and raise pH. Yet, quantitative prediction of the feedbacks between phytoplankton growth, CO2 drawdown and the inorganic carbon chemistry of aquatic ecosystems has received surprisingly little attention. Here, we develop a mathematical model to predict dynamic changes in dissolved inorganic carbon (DIC), pH and alkalinity during phytoplankton bloom development. We tested the model in chemostat experiments with the freshwater cyanobacterium Microcystis aeruginosa at different CO2 levels. The experiments showed that dense blooms sequestered large amounts of atmospheric CO2, not only by their own biomass production but also by inducing a high pH and alkalinity that enhanced the capacity for DIC storage in the system. We used the model to explore how phytoplankton blooms of eutrophic waters will respond to rising CO2 levels. The model predicts that (1) dense phytoplankton blooms in low- and moderately alkaline waters can deplete the dissolved CO2 concentration to limiting levels and raise the pH over a relatively wide range of atmospheric CO2 conditions, (2) rising atmospheric CO2 levels will enhance phytoplankton blooms in low- and moderately alkaline waters with high nutrient loads, and (3) above some threshold, rising atmospheric CO2 will alleviate phytoplankton blooms from carbon limitation, resulting in less intense CO2 depletion and a lesser increase in pH. Sensitivity analysis indicated that the model predictions were qualitatively robust. Quantitatively, the predictions were sensitive to variation in lake depth, DIC input and CO2 gas transfer across the air-water interface, but relatively robust to variation in the carbon uptake mechanisms of phytoplankton. In total, these findings warn that rising CO2 levels may result in a marked intensification of

  7. Community shift from phototrophic to chemotrophic sulfide oxidation following anoxic holomixis in a stratified seawater lake.

    PubMed

    Pjevac, Petra; Korlević, Marino; Berg, Jasmine S; Bura-Nakić, Elvira; Ciglenečki, Irena; Amann, Rudolf; Orlić, Sandi

    2015-01-01

    Most stratified sulfidic holomictic lakes become oxygenated after annual turnover. In contrast, Lake Rogoznica, on the eastern Adriatic coast, has been observed to undergo a period of water column anoxia after water layer mixing and establishment of holomictic conditions. Although Lake Rogoznica's chemistry and hydrography have been studied extensively, it is unclear how the microbial communities typically inhabiting the oxic epilimnion and a sulfidic hypolimnion respond to such a drastic shift in redox conditions. We investigated the impact of anoxic holomixis on microbial diversity and microbially mediated sulfur cycling in Lake Rogoznica with an array of culture-independent microbiological methods. Our data suggest a tight coupling between the lake's chemistry and occurring microorganisms. During stratification, anoxygenic phototrophic sulfur bacteria were dominant at the chemocline and in the hypolimnion. After an anoxic mixing event, the anoxygenic phototrophic sulfur bacteria entirely disappeared, and the homogeneous, anoxic water column was dominated by a bloom of gammaproteobacterial sulfur oxidizers related to the GSO/SUP05 clade. This study is the first report of a community shift from phototrophic to chemotrophic sulfide oxidizers as a response to anoxic holomictic conditions in a seasonally stratified seawater lake. PMID:25344237

  8. Biogeochemistry of natural gases in three alkaline, permanently stratified (meromictic) lakes

    SciTech Connect

    Oremland, R.S.; Miller, L.G. )

    1993-01-01

    Methane and associated light hydrocarbons are present as dissolved gases in the water columns of three alkaline, permanently stratified (meromictic) lakes: Big Soda Lake (Nevada), Mono Lake (California), and Soap Lake (Washington). Methane originates in the bottom sediments, but higher gaseous hydrocarbons (that is, gaseous hydrocarbons of higher molecular weight) have either microbial or thermal sources in the different lakes. Stable isotopic composition, hydrocarbon indices, radiocarbon dating, abundance-versus-depth profiles, and biological experiments indicate that methane is formed in the sediments by microbial processes. Methanogenesis and sulfate-reduction have much higher activity in the shallow littoral sediments than in the colder, more saline pelagic sediments of all three lakes. Methane-rich gas seeps are common in Mono Lake and emanate from a natural-gas deposit underlying the current lakebed. Seeps do not occur in either Big Soda Lake or Soap Lake. Ethane and higher alkanes are present in Big Soda Lake and Mono Lake, but are not present in significant quantities in Soap Lake. It is not clear if the presence of these higher alkanes is a consequence of biological activity, a result of mixing with thermogenic gases, or a combination of both factors. These results indicate the potential complexity and diversity encountered in studying light-hydrocarbon biogeochemistry in thermally and microbially active systems. Hence, in the case of methane, detailed multidisciplinary studies are often needed to determine its origin. For ethane and higher alkanes, there is currently a paucity of basic scientific information to allow for unequivocal identification of microbial and thermogenetic sources. 61 refs., 12 figs., 6 tabs.

  9. Influence of wind and lake morphometry on the interaction between two rivers entering a stratified lake

    USGS Publications Warehouse

    Morillo, S.; Imberger, J.; Antenucci, J.P.; Woods, P.F.

    2008-01-01

    The interaction of two rivers flowing into Coeur d'Alene Lake (United States) was investigated with a field experiment and three-dimensional numerical simulations. The focus was on the influence of basin morphology, wind speed, and wind direction on the fate and transport of the inflowing water. Data from the field campaign showed that intrusions from the two rivers propagated into the lake at different depths, with the trace element polluted Coeur d'Alene River flowing into the lake above the trace element poor and nutrient rich St. Joe River inflow. The inflows initially intruded horizontally into the lake at their level of neutral buoyancy and later mixed vertically. Model results revealed that, as the intrusions entered the main lake basin, a forced horizontal mode-two basin-scale internal wave interacted with the intrusions to frequently siphon them into the lake proper and where rapid vertical mixing followed. The results serve to show how detailed transport and mixing patterns in a lake can have important consequences for the plankton ecology in the lake. ?? 2008 ASCE.

  10. Modeling the Thickness of Perennial Ice Covers on Stratified Lakes of the Taylor Valley, Antarctica

    NASA Technical Reports Server (NTRS)

    Obryk, M. K.; Doran, P. T.; Hicks, J. A.; McKay, C. P.; Priscu, J. C.

    2016-01-01

    A one-dimensional ice cover model was developed to predict and constrain drivers of long term ice thickness trends in chemically stratified lakes of Taylor Valley, Antarctica. The model is driven by surface radiative heat fluxes and heat fluxes from the underlying water column. The model successfully reproduced 16 years (between 1996 and 2012) of ice thickness changes for west lobe of Lake Bonney (average ice thickness = 3.53 m; RMSE = 0.09 m, n = 118) and Lake Fryxell (average ice thickness = 4.22 m; RMSE = 0.21 m, n = 128). Long-term ice thickness trends require coupling with the thermal structure of the water column. The heat stored within the temperature maximum of lakes exceeding a liquid water column depth of 20 m can either impede or facilitate ice thickness change depending on the predominant climatic trend (temperature cooling or warming). As such, shallow (< 20 m deep water columns) perennially ice-covered lakes without deep temperature maxima are more sensitive indicators of climate change. The long-term ice thickness trends are a result of surface energy flux and heat flux from the deep temperature maximum in the water column, the latter of which results from absorbed solar radiation.

  11. Invasive alien species water hyacinth Eichhornia crassipes as abode for macroinvertebrates in hypertrophic Ramsar Site, Lake Xochimilco, Mexico.

    PubMed

    Rocha-Ramirez, A; Robles-Valderrama, E; Ramirez-Flores, E

    2014-11-01

    This paper presents information on the density, diversity and functional feeding groups of macroinvertebrate assemblages associated with water hyacinth in Antiguo Canal Cuemanco, part of Lake Xochimilco in Mexico City. Rare (low frequency and density) and dominant (high frequency and density) taxa prevailed in the assemblages, with the most predominant being Hyalella azteca, Chironomus plumosus and Ischnura denticollis. Nonmetric Multidimensional Scaling confirmed two climatic seasons: warm-rainy and cold-dry; the former with the highest diversity and density of taxa. Canonical Correspondence Analysis showed that conductivity, nitrates and turbidity explained the density variations of taxa. Antiguo Canal Cuemanco waters are spatially homogeneous with the characteristics of hypertrophic shallow lakes, inhabited by scrapers and gathering-collectors. The species found were tolerant to organic pollution.

  12. Light-Dependent Aerobic Methane Oxidation Reduces Methane Emissions from Seasonally Stratified Lakes

    PubMed Central

    Oswald, Kirsten; Milucka, Jana; Brand, Andreas; Littmann, Sten; Wehrli, Bernhard; Kuypers, Marcel M. M.; Schubert, Carsten J.

    2015-01-01

    Lakes are a natural source of methane to the atmosphere and contribute significantly to total emissions compared to the oceans. Controls on methane emissions from lake surfaces, particularly biotic processes within anoxic hypolimnia, are only partially understood. Here we investigated biological methane oxidation in the water column of the seasonally stratified Lake Rotsee. A zone of methane oxidation extending from the oxic/anoxic interface into anoxic waters was identified by chemical profiling of oxygen, methane and δ13C of methane. Incubation experiments with 13C-methane yielded highest oxidation rates within the oxycline, and comparable rates were measured in anoxic waters. Despite predominantly anoxic conditions within the zone of methane oxidation, known groups of anaerobic methanotrophic archaea were conspicuously absent. Instead, aerobic gammaproteobacterial methanotrophs were identified as the active methane oxidizers. In addition, continuous oxidation and maximum rates always occurred under light conditions. These findings, along with the detection of chlorophyll a, suggest that aerobic methane oxidation is tightly coupled to light-dependent photosynthetic oxygen production both at the oxycline and in the anoxic bottom layer. It is likely that this interaction between oxygenic phototrophs and aerobic methanotrophs represents a widespread mechanism by which methane is oxidized in lake water, thus diminishing its release into the atmosphere. PMID:26193458

  13. Protistan diversity in a permanently stratified meromictic lake (Lake Alatsee, SW Germany).

    PubMed

    Oikonomou, Andreas; Filker, Sabine; Breiner, Hans-Werner; Stoeck, Thorsten

    2015-06-01

    Protists play a crucial role for ecosystem function(ing) and oxygen is one of the strongest barriers against their local dispersal. However, protistan diversity in freshwater habitats with oxygen gradients received very little attention. We applied high-throughput sequencing of the V9 region (18S rRNA gene) to provide a hitherto unique spatiotemporal analysis of protistan diversity along the oxygen gradient of a freshwater meromictic lake (Lake Alatsee, SW Germany). In the mixolimnion, the communities experienced most seasonal structural changes, with Stramenopiles dominating in autumn and Dinoflagellata in summer. The suboxic interface supported the highest diversity, but only 23 OTUs95% (mainly Euglenozoa, after quality check and removal of operational taxonomic units (OTUs) with less than three sequences) were exclusively associated with this habitat. Eukaryotic communities in the anoxic monimolimnion showed the most stable seasonal pattern, with Chrysophyta and Bicosoecida being the dominant taxa. Our data pinpoint to the ecological role of the interface as a short-term 'meeting point' for protists, contributing to the coupling of the mixolimnion and the monimolimnion. Our analyses of divergent genetic diversity suggest a high degree of previously undescribed OTUs. Future research will have to reveal if this result actually points to a high number of undescribed species in such freshwater habitats.

  14. Vertical stratification of bacteria and archaea in sediments of a boreal stratified humic lake

    NASA Astrophysics Data System (ADS)

    Rissanen, Antti J.; Mpamah, Promise; Peura, Sari; Taipale, Sami; Biasi, Christina; Nykänen, Hannu

    2015-04-01

    Boreal stratified humic lakes, with steep redox gradients in the water column and in the sediment, are important sources of methane (CH4) to the atmosphere. CH4 flux from these lakes is largely controlled by the balance between CH4-production (methanogenesis), which takes place in the organic rich sediment and in the deepest water layers, and CH4-consumption (methanotrophy), which takes place mainly in the water column. While there is already some published information on the activity, diversity and community structure of bacteria in the water columns of these lakes, such information on sediment microbial communities is very scarce. This study aims to characterize the vertical variation patterns in the diversity and the structure of microbial communities in sediment of a boreal stratified lake. Particular focus is on microbes with the potential to contribute to methanogenesis (fermentative bacteria and methanogenic archaea) and to methanotrophy (methanotrophic bacteria and archaea). Two sediment cores (26 cm deep), collected from the deepest point (~6 m) of a small boreal stratified lake during winter-stratification, were divided into depth sections of 1 to 2 cm for analyses. Communities were studied from DNA extracted from sediment samples by next-generation sequencing (Ion Torrent) of polymerase chain reaction (PCR) - amplified bacterial and archaeal 16S rRNA gene amplicons. The abundance of methanogenic archaea was also specifically studied by quantitative-PCR of methyl coenzyme-M reductase gene (mcrA) amplicons. Furthermore, the community structure and the abundance of bacteria were studied by phospholipid fatty acid (PLFA) analysis. Dominant potential fermentative bacteria belonged to families Syntrophaceae, Clostridiaceae and Peptostreptococcaceae. There were considerable differences in the vertical distribution among these groups. The relative abundance of Syntrophaceae started to increase from the sediment surface, peaked at depth layer from 5 to 10 cm (up

  15. Response in the trophic state of stratified lakes to changes in hydrology and water level: potential effects of climate change

    USGS Publications Warehouse

    Robertson, Dale M.; Rose, William J.

    2011-01-01

    To determine how climate-induced changes in hydrology and water level may affect the trophic state (productivity) of stratified lakes, two relatively pristine dimictic temperate lakes in Wisconsin, USA, were examined. Both are closed-basin lakes that experience changes in water level and degradation in water quality during periods of high water. One, a seepage lake with no inlets or outlets, has a small drainage basin and hydrology dominated by precipitation and groundwater exchange causing small changes in water and phosphorus (P) loading, which resulted in small changes in water level, P concentrations, and productivity. The other, a terminal lake with inlets but no outlets, has a large drainage basin and hydrology dominated by runoff causing large changes in water and P loading, which resulted in large changes in water level, P concentrations, and productivity. Eutrophication models accurately predicted the effects of changes in hydrology, P loading, and water level on their trophic state. If climate changes, larger changes in hydrology and water levels than previously observed could occur. If this causes increased water and P loading, stratified (dimictic and monomictic) lakes are expected to experience higher water levels and become more eutrophic, especially those with large developed drainage basins.

  16. Contrasting patterns of community assembly in the stratified water column of Great Salt Lake, Utah.

    PubMed

    Meuser, Jonathan E; Baxter, Bonnie K; Spear, John R; Peters, John W; Posewitz, Matthew C; Boyd, Eric S

    2013-08-01

    Phylogenetic examinations of communities sampled along geochemical gradients provide a framework for inferring the relative importance of niche-based ecological interactions (competition, environmental filtering) and neutral-based evolutionary interactions in structuring biodiversity. Great Salt Lake (GSL) in Utah exhibits strong spatial gradients due to both seasonal variation in freshwater input into the watershed and restricted fluid flow within North America's largest saline terminal lake ecosystem. Here, we examine the phylogenetic structure and composition of archaeal, bacterial, and eukaryal small subunit (SSU) rRNA genes sampled along a stratified water column (DWR3) in the south arm of GSL in order to infer the underlying mechanism of community assembly. Communities sampled from the DWR3 epilimnion were phylogenetically clustered (i.e., coexistence of close relatives due to environmental filtering) whereas those sampled from the DWR3 hypolimnion were phylogenetically overdispersed (i.e., coexistence of distant relatives due to competitive interactions), with minimal evidence for a role for neutral processes in structuring any assemblage. The shift from phylogenetically clustered to overdispersed assemblages was associated with an increase in salinity and a decrease in dissolved O2 (DO) concentration. Likewise, the phylogenetic diversity and phylogenetic similarity of assemblages was strongly associated with salinity or DO gradients. Thus, salinity and/or DO appeared to influence the mechanism of community assembly as well as the phylogenetic diversity and composition of communities. It is proposed that the observed patterns in the phylogenetic composition and structure of DWR3 assemblages are attributable to the meromictic nature of GSL, which prevents significant mixing between the epilimnion and the hypolimnion. This leads to strong physicochemical gradients at the halocline, which are capable of supporting a greater diversity. However, concomitant

  17. Spatial and Temporal Variations in Bacterial Macromolecule Labeling with [methyl-3H]Thymidine in a Hypertrophic Lake

    PubMed Central

    Robarts, Richard D.; Wicks, Richard J.; Sephton, Lynne M.

    1986-01-01

    The incorporation of [methyl-3H]thymidine into three macromolecular fractions, designated as DNA, RNA, and protein, by bacteria from Hartbeespoort Dam, South Africa, was measured over 1 year by acid-base hydrolysis procedures. Samples were collected at 10 m, which was at least 5 m beneath the euphotic zone. On four occasions, samples were concurrently collected at the surface. Approximately 80% of the label was incorporated into bacterial DNA in surface samples. At 10 m, total incorporation of label into bacterial macromolecules was correlated to bacterial utilization of glucose (r = 0.913, n = 13, P < 0.001). The labeling of DNA, which ranged between 0 and 78% of total macromolecule incorporation, was inversely related to glucose uptake (r = -0.823), total thymidine incorporation (r = -0.737), and euphotic zone algal production (r = -0.732, n = 13, P < 0.005). With decreased DNA labeling, increasing proportions of label were found in the RNA fraction and proteins. Enzymatic digestion followed by chromatographic separation of macromolecule fragments indicated that DNA and proteins were labeled while RNA was not. The RNA fraction may represent labeled lipids or other macromolecules or both. The data demonstrated a close coupling between phytoplankton production and heterotrophic bacterial activity in this hypertrophic lake but also confirmed the need for the routine extraction and purification of DNA during [methyl-3H]thymidine studies of aquatic bacterial production. PMID:16347241

  18. Interference pattern of the sound field in the presence of an internal Kelvin wave in a stratified lake.

    PubMed

    Katsnelson, Boris; Lunkov, Andrey; Ostrovsky, Ilia

    2016-02-01

    Internal Kelvin waves (IKWs) initiated by rotation of the Earth are one of the main hydrodynamic phenomena in large stratified lakes where baroclinic Rossby radius of deformation is smaller than the horizontal scale of the lake. IKWs can be identified using the spectra of internal waves, where in the presence of IKWs, the inertial frequency is at maximum. IKWs play a rather important role in the lake's dynamics for different processes, both in the water layer and sediment, especially at the periphery of lake. Due to influence of internal waves on the sound propagation, acoustical methods can be used for estimation of behaviour of IKWs. In this paper, the spatiotemporal variability of the mid-frequency (∼1 kHz) sound field in the presence of IKWs in a deep stratified Lake Kinneret is studied using numerical simulations based on normal-mode theory. Due to the specific character of perturbation of the water layer, IKWs can cause specific variations of interference pattern, in particular, a significant shift of the sound interference pattern both in spatial and frequency domain. These shifts can be easily measured and used for reconstruction of IKW parameters.

  19. Interference pattern of the sound field in the presence of an internal Kelvin wave in a stratified lake.

    PubMed

    Katsnelson, Boris; Lunkov, Andrey; Ostrovsky, Ilia

    2016-02-01

    Internal Kelvin waves (IKWs) initiated by rotation of the Earth are one of the main hydrodynamic phenomena in large stratified lakes where baroclinic Rossby radius of deformation is smaller than the horizontal scale of the lake. IKWs can be identified using the spectra of internal waves, where in the presence of IKWs, the inertial frequency is at maximum. IKWs play a rather important role in the lake's dynamics for different processes, both in the water layer and sediment, especially at the periphery of lake. Due to influence of internal waves on the sound propagation, acoustical methods can be used for estimation of behaviour of IKWs. In this paper, the spatiotemporal variability of the mid-frequency (∼1 kHz) sound field in the presence of IKWs in a deep stratified Lake Kinneret is studied using numerical simulations based on normal-mode theory. Due to the specific character of perturbation of the water layer, IKWs can cause specific variations of interference pattern, in particular, a significant shift of the sound interference pattern both in spatial and frequency domain. These shifts can be easily measured and used for reconstruction of IKW parameters. PMID:26936569

  20. Hydrological investigation of a multi-stratified pit lake using radioactive and stable isotopes combined with hydrometric monitoring

    NASA Astrophysics Data System (ADS)

    Sánchez-España, Javier; Diez Ercilla, Marta; Pérez Cerdán, Fernando; Yusta, Iñaki; Boyce, Adrian J.

    2014-04-01

    The internal configuration and hydrological dynamics of meromictic pit lakes is often complex and needs to be studied by different tools including stable and radiogenic isotopes. This study combines a multi-isotopic approach (3Hw, δ2Hw, δ18Ow, δ34SSO4) with meteorological, hydrological and hydrochemical monitoring to deduce the flooding history and hydrological dynamics of a meromictic and deeply stratified pit lake (Cueva de la Mora mine, SW Spain). The mine system is complex and includes horizontal galleries, shafts and large rooms physically connected to the mine pit. Specific conductance and temperature profiles obtained in the pit lake draw a physical structure with four monimolimnetic sub-layers of increasing density with depth. This characteristic stratification with m-scale layers separated by sharp transitional zones is rather unusual in other pit lakes and in most natural lakes. Tritium abundance in the different layers indicates that the deep lake water entered the pit basin between 1971 and 1972 which is coincident with the dates of mine closure. The oxygen and deuterium isotope composition of the different layers describes a marked and stable stratification, with an increasing evaporative influence towards the lake surface and a minimal influence of groundwater flow on the structure and composition of the monimolimnion. This study reveals that the initial stages of flooding (via influx of metal- and sulfate-loaded mine drainage from underlying galleries at different depths) may be essential to imprint a layered physical structure to pit lakes which would be very difficult to explain merely by physical processes. After reaching its present water level and morphology, the monimolimnion of this pit lake seems to have remained essentially isolated and chemically unmodified during decades.

  1. Controlling Cyanobacterial Blooms in Hypertrophic Lake Taihu, China: Will Nitrogen Reductions Cause Replacement of Non-N2 Fixing by N2 Fixing Taxa?

    PubMed Central

    Paerl, Hans W.; Xu, Hai; Hall, Nathan S.; Zhu, Guangwei; Qin, Boqiang; Wu, Yali; Rossignol, Karen L.; Dong, Linghan; McCarthy, Mark J.; Joyner, Alan R.

    2014-01-01

    Excessive anthropogenic nitrogen (N) and phosphorus (P) inputs have caused an alarming increase in harmful cyanobacterial blooms, threatening sustainability of lakes and reservoirs worldwide. Hypertrophic Lake Taihu, China’s third largest freshwater lake, typifies this predicament, with toxic blooms of the non-N2 fixing cyanobacteria Microcystis spp. dominating from spring through fall. Previous studies indicate N and P reductions are needed to reduce bloom magnitude and duration. However, N reductions may encourage replacement of non-N2 fixing with N2 fixing cyanobacteria. This potentially counterproductive scenario was evaluated using replicate, large (1000 L), in-lake mesocosms during summer bloom periods. N+P additions led to maximum phytoplankton production. Phosphorus enrichment, which promoted N limitation, resulted in increases in N2 fixing taxa (Anabaena spp.), but it did not lead to significant replacement of non-N2 fixing with N2 fixing cyanobacteria, and N2 fixation rates remained ecologically insignificant. Furthermore, P enrichment failed to increase phytoplankton production relative to controls, indicating that N was the most limiting nutrient throughout this period. We propose that Microcystis spp. and other non-N2 fixing genera can maintain dominance in this shallow, highly turbid, nutrient-enriched lake by outcompeting N2 fixing taxa for existing sources of N and P stored and cycled in the lake. To bring Taihu and other hypertrophic systems below the bloom threshold, both N and P reductions will be needed until the legacy of high N and P loading and sediment nutrient storage in these systems is depleted. At that point, a more exclusive focus on P reductions may be feasible. PMID:25405474

  2. GDGT distribution in a stratified lake and implications for the application of TEX86 in paleoenvironmental reconstructions

    PubMed Central

    Zhang, Zhaohui; Smittenberg, Rienk H.; Bradley, Raymond S.

    2016-01-01

    We investigated the relationship between distributions of GDGTs, GDGT-based proxies and environmental factors in a stratified lake in northwestern Norway. More than 90% of isoGDGTs were produced at the bottom of the oxycline, indicating a predominance of ammonia-oxidizing Group I.1a of Thaumarchaeota, supported by high crenarchaeol/caldarchaeol ratios. Dissolved oxygen content, rather than temperature, exercised a primary control on TEX86 values. In spite of low BIT value in surface sediment, the reconstructed lake surface temperature was “cold” biased. MBT values in streams and lake surface water were significantly smaller than those in the catchment soil, suggesting in situ production of brGDGTs in streams. A rapid transition of MBT vs. temperature/pH relationships occurring at the bottom of oxycline indicated the differential production of various brGDGTs with D.O. and depths. Only within the oxycline were CBT-based pH values close to in situ pH. Our results confirm earlier studies calling for caution in applying TEX86 as a surface temperature proxy, or MBT and/or CBT for reconstructing pH, in anoxic or euxinic lakes, estuaries and ocean basins. We propose that caldarchaeol/crenarchaeol ratio, an indicator of contributions from methanogenic archaea, together with the BIT and TEX86 proxies, can help reconstruct past levels of stratification. PMID:27694918

  3. GDGT distribution in a stratified lake and implications for the application of TEX86 in paleoenvironmental reconstructions

    NASA Astrophysics Data System (ADS)

    Zhang, Zhaohui; Smittenberg, Rienk H.; Bradley, Raymond S.

    2016-10-01

    We investigated the relationship between distributions of GDGTs, GDGT-based proxies and environmental factors in a stratified lake in northwestern Norway. More than 90% of isoGDGTs were produced at the bottom of the oxycline, indicating a predominance of ammonia-oxidizing Group I.1a of Thaumarchaeota, supported by high crenarchaeol/caldarchaeol ratios. Dissolved oxygen content, rather than temperature, exercised a primary control on TEX86 values. In spite of low BIT value in surface sediment, the reconstructed lake surface temperature was “cold” biased. MBT values in streams and lake surface water were significantly smaller than those in the catchment soil, suggesting in situ production of brGDGTs in streams. A rapid transition of MBT vs. temperature/pH relationships occurring at the bottom of oxycline indicated the differential production of various brGDGTs with D.O. and depths. Only within the oxycline were CBT-based pH values close to in situ pH. Our results confirm earlier studies calling for caution in applying TEX86 as a surface temperature proxy, or MBT and/or CBT for reconstructing pH, in anoxic or euxinic lakes, estuaries and ocean basins. We propose that caldarchaeol/crenarchaeol ratio, an indicator of contributions from methanogenic archaea, together with the BIT and TEX86 proxies, can help reconstruct past levels of stratification.

  4. Establishment of microbial eukaryotic enrichment cultures from a chemically stratified antarctic lake and assessment of carbon fixation potential.

    PubMed

    Dolhi, Jenna M; Ketchum, Nicholas; Morgan-Kiss, Rachael M

    2012-01-01

    Lake Bonney is one of numerous permanently ice-covered lakes located in the McMurdo Dry Valleys, Antarctica. The perennial ice cover maintains a chemically stratified water column and unlike other inland bodies of water, largely prevents external input of carbon and nutrients from streams. Biota are exposed to numerous environmental stresses, including year-round severe nutrient deficiency, low temperatures, extreme shade, hypersalinity, and 24-hour darkness during the winter (1). These extreme environmental conditions limit the biota in Lake Bonney almost exclusively to microorganisms (2). Single-celled microbial eukaryotes (called "protists") are important players in global biogeochemical cycling (3) and play important ecological roles in the cycling of carbon in the dry valley lakes, occupying both primary and tertiary roles in the aquatic food web. In the dry valley aquatic food web, protists that fix inorganic carbon (autotrophy) are the major producers of organic carbon for organotrophic organisms (4, 2). Phagotrophic or heterotrophic protists capable of ingesting bacteria and smaller protists act as the top predators in the food web (5). Last, an unknown proportion of the protist population is capable of combined mixotrophic metabolism (6, 7). Mixotrophy in protists involves the ability to combine photosynthetic capability with phagotrophic ingestion of prey microorganisms. This form of mixotrophy differs from mixotrophic metabolism in bacterial species, which generally involves uptake dissolved carbon molecules. There are currently very few protist isolates from permanently ice-capped polar lakes, and studies of protist diversity and ecology in this extreme environment have been limited (8, 4, 9, 10, 5). A better understanding of protist metabolic versatility in the simple dry valley lake food web will aid in the development of models for the role of protists in the global carbon cycle. We employed an enrichment culture approach to isolate potentially

  5. Quadruple sulfur isotope constraints on the origin and cycling of volatile organic sulfur compounds in a stratified sulfidic lake

    NASA Astrophysics Data System (ADS)

    Oduro, Harry; Kamyshny, Alexey; Zerkle, Aubrey L.; Li, Yue; Farquhar, James

    2013-11-01

    We have quantified the major forms of volatile organic sulfur compounds (VOSCs) distributed in the water column of stratified freshwater Fayetteville Green Lake (FGL), to evaluate the biogeochemical pathways involved in their production. The lake's anoxic deep waters contain high concentrations of sulfate (12-16 mmol L-1) and sulfide (0.12 μmol L-1 to 1.5 mmol L-1) with relatively low VOSC concentrations, ranging from 0.1 nmol L-1 to 2.8 μmol L-1. Sulfur isotope measurements of combined volatile organic sulfur compounds demonstrate that VOSC species are formed primarily from reduced sulfur (H2S/HS-) and zero-valent sulfur (ZVS), with little input from sulfate. Thedata support a role of a combination of biological and abiotic processes in formation of carbon-sulfur bonds between reactive sulfur species and methyl groups of lignin components. These processes are responsible for very fast turnover of VOSC species, maintaining their low levels in FGL. No dimethylsulfoniopropionate (DMSP) was detected by Electrospray Ionization Mass Spectrometry (ESI-MS) in the lake water column or in planktonic extracts. These observations indicate a pathway distinct from oceanic and coastal marine environments, where dimethylsulfide (DMS) and other VOSC species are principally produced via the breakdown of DMSP by plankton species.

  6. Vertical variation of bacterial community in Nam Co, a large stratified lake in central Tibetan Plateau.

    PubMed

    Liu, Keshao; Liu, Yongqin; Jiao, Nianzhi; Zhu, Liping; Wang, Junbo; Hu, Anyi; Liu, Xiaobo

    2016-10-01

    We assessed the vertical variation of bacterial abundance, diversity and community composition in deep, high-altitude (4730 m above sea level) Lake Nam Co. The bacterial abundance reduced with increasing depth, while bacterial diversity increased in the deeper bottom water. Pyrosequencing revealed that the bacterial community in the lake showed a pronounced vertical shift: the Bacteroidetes and Proteobacteria had relatively higher abundance in the epilimnion and metalimnion; the Firmicutes group dominated in the metalimnion; the Actinobacteria and Cyanobacteria mainly occupied the metalimnion and hypolimnion. Water temperature, conductivity, photosynthetically active radiation, and chlorophyll a were significantly correlated with the bacterial communities. These results indicated that the bacterial communities appeared to have an apparent vertical structure under lake stratification.

  7. Vertical variation of bacterial community in Nam Co, a large stratified lake in central Tibetan Plateau.

    PubMed

    Liu, Keshao; Liu, Yongqin; Jiao, Nianzhi; Zhu, Liping; Wang, Junbo; Hu, Anyi; Liu, Xiaobo

    2016-10-01

    We assessed the vertical variation of bacterial abundance, diversity and community composition in deep, high-altitude (4730 m above sea level) Lake Nam Co. The bacterial abundance reduced with increasing depth, while bacterial diversity increased in the deeper bottom water. Pyrosequencing revealed that the bacterial community in the lake showed a pronounced vertical shift: the Bacteroidetes and Proteobacteria had relatively higher abundance in the epilimnion and metalimnion; the Firmicutes group dominated in the metalimnion; the Actinobacteria and Cyanobacteria mainly occupied the metalimnion and hypolimnion. Water temperature, conductivity, photosynthetically active radiation, and chlorophyll a were significantly correlated with the bacterial communities. These results indicated that the bacterial communities appeared to have an apparent vertical structure under lake stratification. PMID:27406261

  8. Stratified distribution of nutrients and extremophile biota within freshwater ice covering the surface of Lake Baikal.

    PubMed

    Bondarenko, Nina A; Belykh, Olga I; Golobokova, Ludmila P; Artemyeva, Olga V; Logacheva, Natalia F; Tikhonova, Irina V; Lipko, Irina A; Kostornova, Tatyana Ya; Parfenova, Valentina V; Khodzher, Tamara V; Ahn, Tae-Seok; Zo, Young-Gun

    2012-02-01

    Biological entities and gradients of selected chemicals within the seemingly barren ice layers covering Lake Baikal were investigated. Ice cores 40-68 cm long were obtained from in shore and offshore sites of Southern Lake Baikal during the cold period of a year (March-April) in 2007 and 2008. In microscopic observations of the melted ice, both algae and bacteria were found in considerable numbers (>10(3) cells/L and >10(4) cells/ml, respectively). Among all organisms found, diatom was generally the most predominant taxon in the ice. Interestingly, both planktonic and benthic algae were present in considerable numbers (2-4×10(4) cells/L). Dominant phototrophic picoplankton were comprised of small green algae of various taxa and cyanobacteria of Synechococcus and Cyanobium. The bacterial community consisted mostly of short rod and cocci cells, either free-living or aggregated. Large numbers of yeast-like cells and actinomycete mycelium were also observed. Concentrations of silica, phosphorus, and nitrate were low by an order of magnitude where biota was abundant. The profile of the ice could be interpreted as vertical stratification of nutrients and biomass due to biological activities. Therefore, the organisms in the ice were regarded to maintain high activity while thriving under freezing conditions. Based on the results, it was concluded that the freshwater ice covering the surface of Lake Baikal is considerably populated by extremophilic microorganisms that actively metabolize and form a detritus food chain in the unique large freshwater ecosystem of Lake Baikal. PMID:22367932

  9. Stratified tephra records from lake sediment archives: Holocene eruptions of the Virunga Volcanic Province, East African Rift

    NASA Astrophysics Data System (ADS)

    Lane, Christine; Scholz, Christopher; Poppe, Sam; Schmid, Martin; Ross, Kelly Ann

    2016-04-01

    Lake sediments preserve rare stratified records of explosive volcanism, often with accompanying chronological controls or climatostratigraphic detail. In proximal areas where outcrop stratigraphies are complex, exposures isolated and sediments frequently eroded, the lacustrine archive provides a means to check the order of events and identify additional eruptions not preserved on land. The visible volcanic ash (tephra) record within lake sediments may be limited by eruption volume, distance from source and high sedimentation rates. A more complete eruption history can be detected through the study of non-visible tephra layers. Such "cryptotephra" records may be revealed through non-destructive core-scanning methods, such as XRF-scanning or magnetic susceptibility measurements, or by more thorough laboratory processes and microscopic analysis. Compositional analysis of tephra glass shards using WDS-EPMA and LA-ICP-MS provide a means to provenance eruptions, to cross-correlate between multiple sediment cores, and to establish connections between the lacustrine record and proximal outcrops. Here we present the results of such a "tephrostratigraphic" approach applied to the Holocene volcanic record of the Virunga Volcanic Province (VVP). More than 10 explosive volcanic eruptions, attributed to multiple volcanic centres, are evidenced over the last 12,000 years. This unique insight into the frequency of explosive eruptions from the VVP, demonstrates the potential of visible and cryptotephra investigations in lacustrine sediment archives as a means of studying past, present and future volcanic hazards.

  10. Stably Stratified Flows near a Notched Transverse Ridge across the Salt Lake Valley.

    NASA Astrophysics Data System (ADS)

    Chen, Ying; Ludwig, Francis L.; Street, Robert L.

    2004-09-01

    This paper describes observed and simulated interactions among atmospheric forcing, cold-pool development, and complex mountain terrain at the south end of the Salt Lake valley, near the Jordan Narrows and the Traverse Range. The Advanced Regional Prediction System (ARPS), a three-dimensional, nonhydrostatic compressible new-generation large-eddy simulation code in generalized terrain-following coordinates with advanced model parameterizations, was used. Past studies showed that a finer resolution produces more accurate simulations, and so this study used six one-way nested grids to resolve the complex topography. Horizontal grid spacing ranged from 20 km (initialized by Eta 40-km operational analyses) to 250 m; the finest grid had 200 vertically stretched levels between 5 m and 20 km above the surface. Two intense operating periods with weak synoptic forcing, stable stratification, and pronounced nighttime drainage were selected for simulation from the October 2000 Vertical Transport and Mixing (VTMX) experiment. Qualitative agreement between simulations and observations at four stations was good. Usually, the quantitative agreement was also good. Finer horizontal and vertical resolution improved agreement, capturing daytime and nighttime temperature structures, including inversion-layer strength. The simulations showed a complex flow near the Jordan Narrows, with hydraulic jumps and internal waves initiated by the Traverse Range to either side.

  11. Seasonal distribution of organic matter and copper under stratified conditions in a karstic, marine, sulfide rich environment (Rogoznica Lake, Croatia)

    NASA Astrophysics Data System (ADS)

    Plavšić, Marta; Ciglenečki, Irena; Strmečki, Slađana; Bura-Nakić, Elvira

    2011-04-01

    Closed, isolated small systems, as the representatives of a "unique-environmental feature", are valuable natural laboratories for studying different biogeochemical processes. The saline Rogoznica Lake ("Dragon Eye"), situated on the Eastern Adriatic coast is such a system (10 276 m 2, 15 m deep) typical of many stratified, sulfide rich water bodies. The depth of mixolimnion changes seasonally and it is greatly influenced by meteorological conditions, i.e. temperature and rainfall. Vertical mixing usually occurs during winter when cold, oxygen-rich water from the surface sinks downwards. In 2009 we monitored seasonal distribution and variation of copper complexing capacity (L T), related apparent stability constants (K app), concentration of Cu 2+ ions, surfactant activity (SAS), dissolved organic carbon (DOC) and reduced sulfur species (RSS). Our results have shown that L T is increasing with depth up to 8 m depth, while the concentrations of copper ions decrease with the depth due to the higher amount of RSS species in deeper layers. The values of log K app are also decreasing with depth as a consequence of a competition of organic ligands and sulfide ions for binding Cu. Below 8 m depth the presence of high amounts of RSS (˜1 mM) influences the electrochemical measuring of copper ion and L T determination, contributing to the copper ion binding.

  12. Hypertrophic scar.

    PubMed

    Gabriel, Vincent

    2011-05-01

    Hypertrophic scars are common complications of burn injury and other soft tissue injuries. Excessive extracellular matrix combined with inadequate remodeling of scar tissue results in an aesthetically and functionally unsatisfactory, painful, pruritic scar that can impair function. Treatment options are available to rehabilitation practitioners, but none are entirely satisfactory. An interdisciplinary clinical program is necessary for best outcomes. Challenges to be met by the rehabilitation community include research into the quantification of burn scar measurement, the effects of mechanical forces on wound healing and scar management, and the best combination of surgical, pharmacologic, and therapy interventions to maximize outcome from reconstructive procedures. PMID:21624722

  13. Depth profiles of spectral and hydrological characteristics of water and their relation to abundances of green sulfur bacteria in the stratified lakes of the White Sea

    NASA Astrophysics Data System (ADS)

    Kharcheva, Anastasia V.; Krasnova, Elena D.; Gorlenko, Vladimir M.; Lunina, Olga N.; Savvichev, Alexander S.; Voronov, Dmitry A.; Zhiltsova, Anna A.; Patsaeva, Svetlana V.

    2016-04-01

    We analyze the results received from two expeditions performed in August-September 2013, August-September 2014 and February 2015 in the Kandalaksha Bay of the White Sea. Depth profiles of hydrological characteristics and optical properties of water were recorded for five marine lakes being on different stages of isolation from the White Sea. Those relic lakes demonstrate a tendency to meromixis and are characterized by apparent stratification of the water bodies from the brackish top layer to the bottom salt water. Maximal concentrations of anoxygenic phototrophs (green sulfur bacteria) were found at depths close to the redox interface in all the studied lakes. To discriminate differently pigmented groups of microorganisms the fluorescence emission spectra of bacteriochlorophylls from the living cells were used. We puzzle out the data on light spectrum propagation through the water body in each lake using optical properties of water (attenuation spectra) in the UV, visible and NIR ranges, as well as direct measurements of the total irradiances at various depths. The changes in optical characteristics of water in the stratified reservoirs due to cromophoric dissolved organic matter (CDOM) and microbial pigments affect the light intensity and its spectral distribution at each water layer thus influencing the living conditions for differently pigmented phototrophic microorganisms and determining the composition of microbial community.

  14. Absorption and fluorescence of hydrophobic components of dissolved organic matter in several Karelian lakes with stratified structures

    NASA Astrophysics Data System (ADS)

    Khundzhua, Daria A.; Kharcheva, Anastasia V.; Krasnova, Elena D.; Gorshkova, Olga M.; Chevel, Kira A.; Yuzhakov, Viktor I.; Patsaeva, Svetlana V.

    2016-04-01

    Hydrophobic components of cromophoric dissolved organic matter (CDOM) extracted from water samples and sediments taken in several relic basins located on Karelian shoreline of the White Sea were analyzed using spectroscopic techniques. Those water reservoirs exist at various stages of isolation from the White Sea and represent complex stratified systems of fresh and marine water layers not completely mixing trough the year. Basins separating from the White Sea are the unique natural objects for investigations of properties CDOM, its transformation in the process of turning the marine ecosystem into freshwater environment. CDOM occurring in all types of natural water represents a significant reservoir of organic carbon and plays a key role in the carbon cycle on the Earth. However, aquatic CDOM and nonliving organic matter in sediments from relic separating basins still have not been studied. The target of this work was to study absorption and fluorescence spectra of hydrophobic components of aquatic CDOM from different water depth and sediments in several separated basins of the Kandalaksha Gulf of the White Sea located near the N.A. Pertsov White Sea Biological Station.

  15. Size and elemental distributions of nano- to micro-particulates in the geochemically-stratified Great Salt Lake

    USGS Publications Warehouse

    Diaz, X.; Johnson, W.P.; Fernandez, D.; Naftz, D.L.

    2009-01-01

    The characterization of trace elements in terms of their apportionment among dissolved, macromolecular, nano- and micro-particulate phases in the water column of the Great Salt Lake carries implications for the potential entry of toxins into the food web of the lake. Samples from the anoxic deep and oxic shallow brine layers of the lake were fractionated using asymmetric flow field-flow fractionation (AF4). The associated trace elements were measured via online collision cell inductively-coupled plasma mass spectrometry (CC-ICP-MS). Results showed that of the total (dissolved + particulate) trace element mass, the percent associated with particulates varied from negligible (e.g. Sb), to greater than 50% (e.g. Al, Fe, Pb). Elements such as Cu, Zn, Mn, Co, Au, Hg, and U were associated with nanoparticles, as well as being present as dissolved species. Particulate-associated trace elements were predominantly associated with particulates larger than 450 nm in size. Among the smaller nanoparticulates (<450 nm), some trace elements (Ni, Zn, Au and Pb) showed higher percent mass (associated with nanoparticles) in the 0.9-7.5 nm size range relative to the 10-250 nm size range. The apparent nanoparticle size distributions were similar between the two brine layers; whereas, important differences in elemental associations to nanoparticles were discerned between the two layers. Elements such as Zn, Cu, Pb and Mo showed increasing signal intensities from oxic shallow to anoxic deep brine, suggesting the formation of sulfide nanoparticles, although this may also reflect association with dissolved organic matter. Aluminum and Fe showed greatly increased concentration with depth and equivalent size distributions that differed from those of Zn, Cu, Pb and Mo. Other elements (e.g. Mn, Ni, and Co) showed no significant change in signal intensity with depth. Arsenic was associated with <2 nm nanoparticles, and showed no increase in concentration with depth, possibly indicating

  16. Density-stratified flow events in Great Salt Lake, Utah, USA: implications for mercury and salinity cycling

    USGS Publications Warehouse

    Naftz, David L.; Carling, Gregory T.; Angeroth, Cory; Freeman, Michael; Rowland, Ryan; Pazmiño, Eddy

    2014-01-01

    Density stratification in saline and hypersaline water bodies from throughout the world can have large impacts on the internal cycling and loading of salinity, nutrients, and trace elements. High temporal resolution hydroacoustic and physical/chemical data were collected at two sites in Great Salt Lake (GSL), a saline lake in the western USA, to understand how density stratification may influence salinity and mercury (Hg) distributions. The first study site was in a causeway breach where saline water from GSL exchanges with less saline water from a flow restricted bay. Near-surface-specific conductance values measured in water at the breach displayed a good relationship with both flow and wind direction. No diurnal variations in the concentration of dissolved (total and MeHg loadings was observed during periods of elevated salinity. The second study site was located on the bottom of GSL where movement of a high-salinity water layer, referred to as the deep brine layer (DBL), is restricted to a naturally occurring 1.5-km-wide “spillway” structure. During selected time periods in April/May, 2012, wind-induced flow reversals in a railroad causeway breach, separating Gunnison and Gilbert Bays, were coupled with high-velocity flow pulses (up to 55 cm/s) in the DBL at the spillway site. These flow pulses were likely driven by a pressure response of highly saline water from Gunnison Bay flowing into the north basin of Gilbert Bay. Short-term flow reversal events measured at the railroad causeway breach have the ability to move measurable amounts of salt and Hg from Gunnison Bay into the DBL. Future disturbance to the steady state conditions currently imposed by the railroad causeway infrastructure could result in changes to the existing chemical balance between Gunnison and Gilbert Bays. Monitoring instruments were installed at six additional sites in the DBL during October 2012 to assess impacts from any future modifications to the railroad causeway.

  17. Hypertrophic discoid lupus erythematosus.

    PubMed

    Farley-Loftus, Rachel; Elmariah, Sarina B; Ralston, Jonathan; Kamino, Hideko; Franks, Andrew G

    2010-11-15

    Hypertrophic discoid lupus erythematosus is a distinct form of chronic cutaneous (discoid) lupus, which is characterized by hyperkeratotic plaques that typically are observed over the face, arms, and upper trunk. We present the case of a 43-year-old man with verrucous plaques that were distributed symmetrically over the face, who initially was treated with oral antibiotics and topical glucocorticoids for acne vulgaris. A biopsy specimen confirmed the diagnosis of hypertrophic discoid lupus erythematosus. The clinical and histopathologic features of this clinical variant are reviewed.

  18. Hypertrophic Cardiomyopathy: A Review

    PubMed Central

    Houston, Brian A; Stevens, Gerin R

    2014-01-01

    Hypertrophic cardiomyopathy (HCM) is a global disease with cases reported in all continents, affecting people of both genders and of various racial and ethnic origins. Widely accepted as a monogenic disease caused by a mutation in 1 of 13 or more sarcomeric genes, HCM can present catastrophically with sudden cardiac death (SCD) or ventricular arrhythmias or insidiously with symptoms of heart failure. Given the velocity of progress in both the fields of heart failure and HCM, we present a review of the approach to patients with HCM, with particular attention to those with HCM and the clinical syndrome of heart failure. PMID:25657602

  19. Hypertrophic cardiomyopathy: a review.

    PubMed

    Hensley, Nadia; Dietrich, Jennifer; Nyhan, Daniel; Mitter, Nanhi; Yee, May-Sann; Brady, MaryBeth

    2015-03-01

    Hypertrophic cardiomyopathy (HCM) is a relatively common disorder that anesthesiologists encounter among patients in the perioperative period. Fifty years ago, HCM was thought to be an obscure disease. Today, however, our understanding and ability to diagnose patients with HCM have improved dramatically. Patients with HCM have genotypic and phenotypic variability. Indeed, a subgroup of these patients exhibits the HCM genotype but not the phenotype (left ventricular hypertrophy). There are a number of treatment modalities for these patients, including pharmacotherapy to control symptoms, implantable cardiac defibrillators to manage malignant arrhythmias, and surgical myectomy and septal ablation to decrease the left ventricular outflow obstruction. Accurate diagnosis is vital for the perioperative management of these patients. Diagnosis is most often made using echocardiographic assessment of left ventricular hypertrophy, left ventricular outflow tract gradients, systolic and diastolic function, and mitral valve anatomy and function. Cardiac magnetic resonance imaging also has a diagnostic role by determining the extent and location of left ventricular hypertrophy and the anatomic abnormalities of the mitral valve and papillary muscles. In this review on hypertrophic cardiomyopathy for the noncardiac anesthesiologist, we discuss the clinical presentation and genetic mutations associated with HCM, the critical role of echocardiography in the diagnosis and the assessment of surgical interventions, and the perioperative management of patients with HCM undergoing noncardiac surgery and management of the parturient with HCM. PMID:25695573

  20. A hydrodynamics-based approach to evaluating the risk of waterborne pathogens entering drinking water intakes in a large, stratified lake.

    PubMed

    Hoyer, Andrea B; Schladow, S Geoffrey; Rueda, Francisco J

    2015-10-15

    Pathogen contamination of drinking water lakes and reservoirs is a severe threat to human health worldwide. A major source of pathogens in surface sources of drinking waters is from body-contact recreation in the water body. However, dispersion pathways of human waterborne pathogens from recreational beaches, where body-contact recreation is known to occur to drinking water intakes, and the associated risk of pathogens entering the drinking water supply remain largely undocumented. A high spatial resolution, three-dimensional hydrodynamic and particle tracking modeling approach has been developed to analyze the risk and mechanisms presented by pathogen dispersion. The pathogen model represents the processes of particle release, transport and survival. Here survival is a function of both water temperature and cumulative exposure to ultraviolet (UV) radiation. Pathogen transport is simulated using a novel and computationally efficient technique of tracking particle trajectories backwards, from a drinking water intake toward their source areas. The model has been applied to a large, alpine lake - Lake Tahoe, CA-NV (USA). The dispersion model results reveal that for this particular lake (1) the risk of human waterborne pathogens to enter drinking water intakes is low, but significant; (2) this risk is strongly related to the depth of the thermocline in relation to the depth of the intake; (3) the risk increases with the seasonal deepening of the surface mixed layer; and (4) the risk increases at night when the surface mixed layer deepens through convective mixing and inactivation by UV radiation is eliminated. While these risk factors will quantitatively vary in different lakes, these same mechanisms will govern the process of transport of pathogens.

  1. Update on hypertrophic scar treatment

    PubMed Central

    Rabello, Felipe Bettini; Souza, Cleyton Dias; Júnior, Jayme Adriano Farina

    2014-01-01

    Scar formation is a consequence of the wound healing process that occurs when body tissues are damaged by a physical injury. Hypertrophic scars and keloids are pathological scars resulting from abnormal responses to trauma and can be itchy and painful, causing serious functional and cosmetic disability. The current review will focus on the definition of hypertrophic scars, distinguishing them from keloids and on the various methods for treating hypertrophic scarring that have been described in the literature, including treatments with clearly proven efficiency and therapies with doubtful benefits. Numerous methods have been described for the treatment of abnormal scars, but to date, the optimal treatment method has not been established. This review will explore the differences between different types of nonsurgical management of hypertrophic scars, focusing on the indications, uses, mechanisms of action, associations and efficacies of the following therapies: silicone, pressure garments, onion extract, intralesional corticoid injections and bleomycin. PMID:25141117

  2. Update on hypertrophic scar treatment.

    PubMed

    Rabello, Felipe Bettini; Souza, Cleyton Dias; Farina Júnior, Jayme Adriano

    2014-08-01

    Scar formation is a consequence of the wound healing process that occurs when body tissues are damaged by a physical injury. Hypertrophic scars and keloids are pathological scars resulting from abnormal responses to trauma and can be itchy and painful, causing serious functional and cosmetic disability. The current review will focus on the definition of hypertrophic scars, distinguishing them from keloids and on the various methods for treating hypertrophic scarring that have been described in the literature, including treatments with clearly proven efficiency and therapies with doubtful benefits. Numerous methods have been described for the treatment of abnormal scars, but to date, the optimal treatment method has not been established. This review will explore the differences between different types of nonsurgical management of hypertrophic scars, focusing on the indications, uses, mechanisms of action, associations and efficacies of the following therapies: silicone, pressure garments, onion extract, intralesional corticoid injections and bleomycin. PMID:25141117

  3. Misconceptions and Facts About Hypertrophic Cardiomyopathy.

    PubMed

    Argulian, Edgar; Sherrid, Mark V; Messerli, Franz H

    2016-02-01

    Hypertrophic cardiomyopathy is the most common genetic heart disease. Once considered relentless, untreatable, and deadly, it has become a highly treatable disease with contemporary management. Hypertrophic cardiomyopathy is one of cardiology's "great masqueraders." Mistakes and delays in diagnosis abound. Hypertrophic cardiomyopathy commonly "masquerades" as asthma, anxiety, mitral prolapse, and coronary artery disease. However, once properly diagnosed, patients with hypertrophic cardiomyopathy can be effectively managed to improve both symptoms and survival. This review highlights some of the misconceptions about hypertrophic cardiomyopathy. Providers at all levels should have awareness of hypertrophic cardiomyopathy to promptly diagnose and properly manage these individuals. PMID:26299316

  4. Lake

    ERIC Educational Resources Information Center

    Wien, Carol Anne

    2008-01-01

    The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

  5. Cardiac arrhythmias in hypertrophic cardiomyopathy.

    PubMed Central

    Bjarnason, I; Hardarson, T; Jonsson, S

    1982-01-01

    This study was designed to assess the prevalence of cardiac arrhythmias in a group of relatives of patients who had come to necropsy with hypertrophic cardiomyopathy. Another aim of the study was to assess the validity of an interventricular septal thickness of 1.3 cm or more, measured by echocardiography, as a diagnostic criterion of hypertrophic cardiomyopathy among relatives of cases proven at necropsy. Fifty close relatives of eight deceased patients were examined. By the above definition 22 relatives had hypertrophic cardiomyopathy and 28 did not. A comparison of the prevalence and types of cardiac arrhythmias, as shown by 24 hour ambulatory electrocardiographic monitoring, was made between the two groups and a third apparently healthy group of 40 people. The patients with hypertrophic cardiomyopathy showed a significant increase in supraventricular extrasystoles/24 hours, supraventricular arrhythmias, high grade ventricular arrhythmia, and the number of patients with more than 10 ventricular extrasystoles every 24 hours when compared with the other groups. There was no significant difference between normal relatives and controls. The prevalence and types of arrhythmia in these patients were similar to those found by other investigators using different diagnostic criteria. These results support the contention that these patients do indeed have hypertrophic cardiomyopathy and suggest that all close relatives of necropsy proven cases should be examined by echocardiography and subsequently by ambulatory electrocardiographic monitoring if the interventricular septal thickness is 1.3 more. PMID:7201843

  6. Geohydrology, water quality, and simulation of groundwater flow in the stratified-drift aquifer system in Virgil Creek and Dryden Lake Valleys, Town of Dryden, Tompkins County, New York

    USGS Publications Warehouse

    Miller, Todd S.; Bugliosi, Edward F.

    2013-01-01

    In 2002, the U.S. Geological Survey, in cooperation with the Tompkins County Planning Department and the Town of Dryden, New York, began a study of the stratified-drift aquifer system in the Virgil Creek and Dryden Lake Valleys in the Town of Dryden, Tompkins County. The study provided geohydrologic data needed by the town and county to develop a strategy to manage and protect their water resources. In this study area, three extensive confined sand and gravel aquifers (the upper, middle, and lower confined aquifers) compose the stratified-drift aquifer system. The Dryden Lake Valley is a glaciated valley oriented parallel to the direction of ice movement. Erosion by ice extensively widened and deepened the valley, truncated bedrock hillsides, and formed a nearly straight, U-shaped bedrock trough. The maximum thickness of the valley fill in the central part of the valley is about 400 feet (ft). The Virgil Creek Valley in the east part of the study area underwent less severe erosion by ice than the Dryden Lake Valley, and hence, it has a bedrock floor that is several hundred feet higher in altitude than that in the Dryden Lake Valley. The sources and amounts of recharge were difficult to identify in most areas because the confined aquifers are overlain by confining units. However, in the vicinity of the Virgil Creek Dam, the upper confined aquifer crops out at land surface in the floodplain of a gorge eroded by Virgil Creek, and this is where the aquifer receives large amounts of recharge from precipitation that directly falls over the aquifer and from seepage losses from Virgil Creek. The results of streamflow measurements made in Virgil Creek where it flows through the gorge indicated that the stream lost 1.2 cubic feet per second (ft3/s) or 0.78 million gallons per day (Mgal/d) of water in the reach extending from 220 ft downstream from the dam to 1,200 ft upstream from the dam. In the southern part of the study area, large amounts of recharge also replenish the

  7. Optical Measurements Reveal Interplay Between Surface and Bottom Processes Involving Phytoplankton, Organic Carbon, Iron, Light, and Oxygen in Two Stratified Mesotrophic Lakes

    NASA Astrophysics Data System (ADS)

    Hargreaves, B. R.; Vaidya, A.; Wiles, K. A.

    2009-12-01

    Water column distribution of phytoplankton, organic carbon, particulate and dissolved iron are described through detailed vertical optical measurements that include downwelling cosine irradiance, turbidity, dissolved oxygen, fluorescence by CDOM, Chl-a, phycobilin pigments, and diffuse attenuation for several UV wavebands, plus pH, temperature, and specific conductance. These measurements were completed with a group of profiling instruments during summer in two mid-latitude small lakes. Special calibration allowed for correcting the impact of CDOM and turbidity on the pigment fluorescence signals. These in situ data were combined with laboratory analysis of discrete water column samples for methanol-extracted chlorophyll-a, spectral absorbance of particles, concentration of particulates (dry mass and ash-free mass), total particulate and "dissolved" iron, DOC and CDOM (the "dissolved fraction" passes through a GF/F filter). Surface processes revealed by these measurement include solar heating and photobleaching of CDOM (partly distributed by wind-driven mixing), and nonphotochemical quenching of phytoplankton chlorophyll-a fluorescence. Bottom processes revealed by these measurements include oxygen consumption by net heterotrophic metabolism, release of DOC, CDOM, and iron from anoxic bottom sediments, and the development of a biological community structured by the light and temperature gradients and absence or scarcity of dissolved oxygen near the bottom. The iron associated with CDOM and particles in the deep samples substantially increased the latter's DOC-specific absorption once there was an opportunity for oxidation. A model for mass-specific spectral absorption of particulates accounts for the contribution of organic matter and iron associated with the particles. A detailed hydrologic budget for one of the lakes will allow the water column processes to be explored further by accounting for inputs and outputs of water and organic carbon (via precipitation

  8. Geohydrology, water quality, and simulation of groundwater flow in the stratified-drift aquifer system in Virgil Creek and Dryden Lake Valleys, Town of Dryden, Tompkins County, New York

    USGS Publications Warehouse

    Miller, Todd S.; Bugliosi, Edward F.

    2013-01-01

    In 2002, the U.S. Geological Survey, in cooperation with the Tompkins County Planning Department and the Town of Dryden, New York, began a study of the stratified-drift aquifer system in the Virgil Creek and Dryden Lake Valleys in the Town of Dryden, Tompkins County. The study provided geohydrologic data needed by the town and county to develop a strategy to manage and protect their water resources. In this study area, three extensive confined sand and gravel aquifers (the upper, middle, and lower confined aquifers) compose the stratified-drift aquifer system. The Dryden Lake Valley is a glaciated valley oriented parallel to the direction of ice movement. Erosion by ice extensively widened and deepened the valley, truncated bedrock hillsides, and formed a nearly straight, U-shaped bedrock trough. The maximum thickness of the valley fill in the central part of the valley is about 400 feet (ft). The Virgil Creek Valley in the east part of the study area underwent less severe erosion by ice than the Dryden Lake Valley, and hence, it has a bedrock floor that is several hundred feet higher in altitude than that in the Dryden Lake Valley. The sources and amounts of recharge were difficult to identify in most areas because the confined aquifers are overlain by confining units. However, in the vicinity of the Virgil Creek Dam, the upper confined aquifer crops out at land surface in the floodplain of a gorge eroded by Virgil Creek, and this is where the aquifer receives large amounts of recharge from precipitation that directly falls over the aquifer and from seepage losses from Virgil Creek. The results of streamflow measurements made in Virgil Creek where it flows through the gorge indicated that the stream lost 1.2 cubic feet per second (ft3/s) or 0.78 million gallons per day (Mgal/d) of water in the reach extending from 220 ft downstream from the dam to 1,200 ft upstream from the dam. In the southern part of the study area, large amounts of recharge also replenish the

  9. Topical treatments for hypertrophic scars.

    PubMed

    Zurada, Joanna M; Kriegel, David; Davis, Ira C

    2006-12-01

    Hypertrophic scars represent an abnormal, exaggerated healing response after skin injury. In addition to cosmetic concern, scars may cause pain, pruritus, contractures, and other functional impairments. Therapeutic modalities include topical medications, intralesional corticosteroids, laser therapy, and cryosurgery. Topical therapies, in particular, have become increasingly popular because of their ease of use, comfort, noninvasiveness, and relatively low cost. This review will discuss the properties and effectiveness of these agents, including pressure therapy, silicone gel sheeting and ointment, polyurethane dressing, onion extract, imiquimod 5% cream, and vitamins A and E in the prevention and treatment of hypertrophic scars. PMID:17097399

  10. Hypertrophic lupus vulgaris: an unusual presentation.

    PubMed

    Jain, Vijay K; Aggarwal, Kamal; Jain, Sarika; Singh, Sunita

    2009-07-01

    Lupus vulgaris is the most common form of cutaneous tuberculosis occurring in previously sensitized individuals with a high degree of tuberculin sensitivity. Various forms including plaque, ulcerative, hypertrophic, vegetative, papular, and nodular forms have been described. A 30-year-old male patient presented with a very large hypertrophic lupus vulgaris lesion over left side of chest since 22 years. Histopathological examination showed granulomatous infiltration without caseation necrosis. The Mantoux reaction was strongly positive. Hypertrophic lupus vulgaris of such a giant size and that too at an unusual site is extremely rare and hence is being reported.

  11. Laser application for hypertrophic rhinitis

    NASA Astrophysics Data System (ADS)

    Inouye, Tetsuzo; Tanabe, Tetsuya; Nakanoboh, Manabu; Ogura, Masami

    1995-05-01

    The CO2 and KTP/532 lasers have been used in the treatment of an allergic and hypertrophic rhinitis for the past several years. As we know, the laser enables a surgeon to perform the operation with minimum hemorrhage and minimized pain, during and after the procedure. Additionally many of these operations can be performed under local anesthesia instead of general anesthesia, on an outpatient basis. The laser is used to irradiate the mucous membranes of the inferior turbinates. Vaporization and cutting is easily done. Post operative management of the local operated area is easy. The advantages of laser surgery over regular surgical techniques are supreme for intranasal operations when performed under local anesthesia.

  12. A common factor in hypertrophic osteoarthropathy

    PubMed Central

    Carroll, K. B.; Doyle, L.

    1974-01-01

    Carroll, K. B. and Doyle, L. (1974).Thorax, 29, 262-264. A common factor in hypertrophic osteoarthropathy. Two cases of oesophageal disease with hypertrophic osteoarthropathy are presented. The unusual site of the primary lesion has prompted a review of the literature and led to the conclusion that there is a common innervation accounting for a common afferent arc which is an integral and basic part of the mechanism in this disorder. Images PMID:4831530

  13. Hypertrophic pachymeningitis accompanying neuromyelitis optica spectrum disorder: A case report.

    PubMed

    Kon, Tomoya; Nishijima, Haruo; Haga, Rie; Funamizu, Yukihisa; Ueno, Tatsuya; Arai, Akira; Suzuki, Chieko; Nunomura, Jin-ichi; Baba, Masayuki; Takahashi, Toshiyuki; Tomiyama, Masahiko

    2015-10-15

    We report a case of idiopathic cerebral hypertrophic pachymeningitis accompanying neuromyelitis optica spectrum disorder. No other identifiable cause of pachymeningitis was detected. Corticosteroid therapy was effective for both diseases. Hypertrophic pachymeningitis is closely related to autoimmune inflammatory disease of the central nervous system. This case supports the hypothesis that hypertrophic pachymeningitis can be a rare comorbidity of neuromyelitis optica spectrum disorder.

  14. Primary hypertrophic osteoarthropathy (pachydermoperiostosis): a case report.

    PubMed

    Karkucak, Murat; Erturk, Engin; Capkin, Erhan; Akyazi, Hikmet; Ozden, Gonca; Tosun, Mehmet

    2007-02-01

    Hypertrophic osteoarthropathy is characterized by digital clubbing and periosteal reaction of long bones. Most cases are associated with malignancy or other conditions such as congenital heart disease, liver cirrhosis, pulmonary fibrosis, biliary atresia, and gastrointestinal polyps. We report a 19-year-old man presenting with arthritis, broadening of the fingers and clubbing of the fingers and toes for the previous 3 years. The ankles and knees were swollen. X-rays showed periosteal apposition. The search for a secondary cause remained negative. In cases of arthralgia/arthritis together with clubbed fingers, consideration must be given to hypertrophic osteoarthropathy. The primary or idiopathic form is rare and has a good prognosis.

  15. Hypertrophic cardiomyopathy in a college athlete.

    PubMed

    Simons, S M; Moriarity, J

    1992-12-01

    The greatest catastrophy in sports is an athlete's unexpected sudden death. Identifying those athletes at risk remains a great challenge to physicians performing preseason examinations. Hypertrophic cardiomyopathy is the most common cause of nontraumatic sudden death in athletes. Most cases of this diseased heart are diagnosed easily by echocardiography. The case presented exemplifies the attention to detail required to differentiate the borderline diseased heart from the conditioned athletic heart. Once a diagnosis of hypertrophic cardiomyopathy is made, further participation in intense physical exercise is discouraged. This recommendation is necessary despite the unknown relative sudden death risk for the minimal criteria cases.

  16. Infective endocarditis in hypertrophic cardiomyopathy

    PubMed Central

    Dominguez, Fernando; Ramos, Antonio; Bouza, Emilio; Muñoz, Patricia; Valerio, Maricela C.; Fariñas, M. Carmen; de Berrazueta, José Ramón; Zarauza, Jesús; Pericás Pulido, Juan Manuel; Paré, Juan Carlos; de Alarcón, Arístides; Sousa, Dolores; Rodriguez Bailón, Isabel; Montejo-Baranda, Miguel; Noureddine, Mariam; García Vázquez, Elisa; Garcia-Pavia, Pablo

    2016-01-01

    Abstract Infective endocarditis (IE) complicating hypertrophic cardiomyopathy (HCM) is a poorly known entity. Although current guidelines do not recommend IE antibiotic prophylaxis (IEAP) in HCM, controversy remains. This study sought to describe the clinical course of a large series of IE HCM and to compare IE in HCM patients with IE patients with and without an indication for IEAP. Data from the GAMES IE registry involving 27 Spanish hospitals were analyzed. From January 2008 to December 2013, 2000 consecutive IE patients were prospectively included in the registry. Eleven IE HCM additional cases from before 2008 were also studied. Clinical, microbiological, and echocardiographic characteristics were analyzed in IE HCM patients (n = 34) and in IE HCM reported in literature (n = 84). Patients with nondevice IE (n = 1807) were classified into 3 groups: group 1, HCM with native-valve IE (n = 26); group 2, patients with IEAP indication (n = 696); group 3, patients with no IEAP indication (n = 1085). IE episode and 1-year follow-up data were gathered. One-year mortality in IE HCM was 42% in our study and 22% in the literature. IE was more frequent, although not exclusive, in obstructive HCM (59% and 74%, respectively). Group 1 exhibited more IE predisposing factors than groups 2 and 3 (62% vs 40% vs 50%, P < 0.01), and more previous dental procedures (23% vs 6% vs 8%, P < 0.01). Furthermore, Group 1 experienced a higher incidence of Streptococcus infections than Group 2 (39% vs 22%, P < 0.01) and similar to Group 3 (39% vs 30%, P = 0.34). Overall mortality was similar among groups (42% vs 36% vs 35%, P = 0.64). IE occurs in HCM patients with and without obstruction. Mortality of IE HCM is high but similar to patients with and without IEAP indication. Predisposing factors, previous dental procedures, and streptococcal infection are higher in IE HCM, suggesting that HCM patients could benefit from IEAP. PMID:27368014

  17. Aortic biomechanics in hypertrophic cardiomyopathy

    PubMed Central

    Badran, Hala Mahfouz; Soltan, Ghada; Faheem, Nagla; Elnoamany, Mohamed Fahmy; Tawfik, Mohamed; Yacoub, Magdi

    2015-01-01

    Background: Ventricular-vascular coupling is an important phenomenon in many cardiovascular diseases. The association between aortic mechanical dysfunction and left ventricular (LV) dysfunction is well characterized in many disease entities, but no data are available on how these changes are related in hypertrophic cardiomyopathy (HCM). Aim of the work: This study examined whether HCM alone is associated with an impaired aortic mechanical function in patients without cardiovascular risk factors and the relation of these changes, if any, to LV deformation and cardiac phenotype. Methods: 141 patients with HCM were recruited and compared to 66 age- and sex-matched healthy subjects as control group. Pulse pressure, aortic strain, stiffness and distensibility were calculated from the aortic diameters measured by M-mode echocardiography and blood pressure obtained by sphygmomanometer. Aortic wall systolic and diastolic velocities were measured using pulsed wave Doppler tissue imaging (DTI). Cardiac assessment included geometric parameters and myocardial deformation (strain and strain rate) and mechanical dyssynchrony. Results: The pulsatile change in the aortic diameter, distensibility and aortic wall systolic velocity (AWS') were significantly decreased and aortic stiffness index was increased in HCM compared to control (P < .001) In HCM AWS' was inversely correlated to age(r = − .32, P < .0001), MWT (r = − .22, P < .008), LVMI (r = − .20, P < .02), E/Ea (r = − .16, P < .03) LVOT gradient (r = − 19, P < .02) and severity of mitral regurg (r = − .18, P < .03) but not to the concealed LV deformation abnormalities or mechanical dyssynchrony. On multivariate analysis, the key determinant of aortic stiffness was LV mass index and LVOT obstruction while the role LV dysfunction in aortic stiffness is not evident in this population. Conclusion: HCM is associated with abnormal aortic mechanical properties. The severity of cardiac

  18. Contractile Dysfunction in Sarcomeric Hypertrophic Cardiomyopathy.

    PubMed

    MacIver, David H; Clark, Andrew L

    2016-09-01

    The pathophysiological mechanisms underlying the clinical phenotype of sarcomeric hypertrophic cardiomyopathy are controversial. The development of cardiac hypertrophy in hypertension and aortic stenosis is usually described as a compensatory mechanism that normalizes wall stress. We suggest that an important abnormality in hypertrophic cardiomyopathy is reduced contractile stress (the force per unit area) generated by myocardial tissue secondary to abnormalities such as cardiomyocyte disarray. In turn, a progressive deterioration in contractile stress provokes worsening hypertrophy and disarray. A maintained or even exaggerated ejection fraction is explained by the increased end-diastolic wall thickness producing augmented thickening. We propose that the nature of the hemodynamic load in an individual with hypertrophic cardiomyopathy could determine its phenotype. Hypertensive patients with hypertrophic cardiomyopathy are more likely to develop exaggerated concentric hypertrophy; athletic individuals an asymmetric pattern; and inactive individuals a more apical hypertrophy. The development of a left ventricular outflow tract gradient and mitral regurgitation may be explained by differential regional strain resulting in mitral annular rotation.

  19. Hypertrophic Cardiomyopathy in Athletes: Catching a Killer.

    ERIC Educational Resources Information Center

    Maron, Barry J.

    1993-01-01

    A leading cause of sudden death among young athletes, hypertrophic cardiomyopathy (HCM) does not always present cardiac signs and symptoms. Echocardiography offers the most effective means for diagnosis. Some patients require pharmaceutical or surgical intervention. Patients with HCM should not engage in organized competitive sports or…

  20. An unusual ST-segment elevation: apical hypertrophic cardiomyopathy shows the ace up its sleeve.

    PubMed

    de Santis, Francesco; Pergolini, Amedeo; Zampi, Giordano; Pero, Gaetano; Pino, Paolo Giuseppe; Minardi, Giovanni

    2013-01-01

    Apical hypertrophic cardiomyopathy is part of the broad clinical and morphologic spectrum of hypertrophic cardiomyopathy. We report a patient with electrocardiographic abnormalities in whom acute coronary syndrome was excluded and apical hypertrophic cardiomyopathy was demonstrated by careful differential diagnosis.

  1. Calcification of in vitro developed hypertrophic cartilage

    SciTech Connect

    Tacchetti, C.; Quarto, R.; Campanile, G.; Cancedda, R.

    1989-04-01

    We have recently reported that dedifferentiated cells derived from stage 28-30 chick embryo tibiae, when transferred in suspension culture in the presence of ascorbic acid, develop in a tissue closely resembling hypertrophic cartilage. Ultrastructural examination of this in vitro formed cartilage showed numerous matrix vesicles associated with the extracellular matrix. In the present article we report that the in vitro developed hypertrophic cartilage undergoes calcification. We indicate a correlation between the levels of alkaline phosphatase activity and calcium deposition at different times of development. Following the transfer of cells into suspension culture and an initial lag phase, the level of alkaline phosphatase activity rapidly increased. In most experiments the maximum of activity was reached after 5 days of culture. When alkaline phosphatase activity and /sup 45/Ca deposition were measured in the same experiment, we observed that the increase in alkaline phosphatase preceded the deposition of nonwashable calcium deposits in the cartilage.

  2. The embryological basis of subclinical hypertrophic cardiomyopathy.

    PubMed

    Captur, Gabriella; Ho, Carolyn Y; Schlossarek, Saskia; Kerwin, Janet; Mirabel, Mariana; Wilson, Robert; Rosmini, Stefania; Obianyo, Chinwe; Reant, Patricia; Bassett, Paul; Cook, Andrew C; Lindsay, Susan; McKenna, William J; Mills, Kevin; Elliott, Perry M; Mohun, Timothy J; Carrier, Lucie; Moon, James C

    2016-06-21

    Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomeric proteins, the commonest being MYBPC3 encoding myosin-binding protein C. It is characterised by left ventricular hypertrophy but there is an important pre-hypertrophic phenotype with features including crypts, abnormal mitral leaflets and trabeculae. We investigated these during mouse cardiac development using high-resolution episcopic microscopy. In embryonic hearts from wildtype, homozygous (HO) and heterozygous (HET) Mybpc3-targeted knock-out (KO) mice we show that crypts (one or two) are a normal part of wildtype development but they almost all resolve by birth. By contrast, HO and HET embryos had increased crypt presence, abnormal mitral valve formation and alterations in the compaction process. In scarce normal human embryos, crypts were sometimes present. This study shows that features of the human pre-hypertrophic HCM phenotype occur in the mouse. In an animal model we demonstrate that there is an embryological HCM phenotype. Crypts are a normal part of cardiac development but, along with the mitral valve and trabeculae, their developmental trajectory is altered by the presence of HCM truncating Mybpc3 gene mutation.

  3. The embryological basis of subclinical hypertrophic cardiomyopathy

    PubMed Central

    Captur, Gabriella; Ho, Carolyn Y.; Schlossarek, Saskia; Kerwin, Janet; Mirabel, Mariana; Wilson, Robert; Rosmini, Stefania; Obianyo, Chinwe; Reant, Patricia; Bassett, Paul; Cook, Andrew C.; Lindsay, Susan; McKenna, William J.; Mills, Kevin; Elliott, Perry M.; Mohun, Timothy J.; Carrier, Lucie; Moon, James C.

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomeric proteins, the commonest being MYBPC3 encoding myosin-binding protein C. It is characterised by left ventricular hypertrophy but there is an important pre-hypertrophic phenotype with features including crypts, abnormal mitral leaflets and trabeculae. We investigated these during mouse cardiac development using high-resolution episcopic microscopy. In embryonic hearts from wildtype, homozygous (HO) and heterozygous (HET) Mybpc3-targeted knock-out (KO) mice we show that crypts (one or two) are a normal part of wildtype development but they almost all resolve by birth. By contrast, HO and HET embryos had increased crypt presence, abnormal mitral valve formation and alterations in the compaction process. In scarce normal human embryos, crypts were sometimes present. This study shows that features of the human pre-hypertrophic HCM phenotype occur in the mouse. In an animal model we demonstrate that there is an embryological HCM phenotype. Crypts are a normal part of cardiac development but, along with the mitral valve and trabeculae, their developmental trajectory is altered by the presence of HCM truncating Mybpc3 gene mutation. PMID:27323879

  4. The embryological basis of subclinical hypertrophic cardiomyopathy.

    PubMed

    Captur, Gabriella; Ho, Carolyn Y; Schlossarek, Saskia; Kerwin, Janet; Mirabel, Mariana; Wilson, Robert; Rosmini, Stefania; Obianyo, Chinwe; Reant, Patricia; Bassett, Paul; Cook, Andrew C; Lindsay, Susan; McKenna, William J; Mills, Kevin; Elliott, Perry M; Mohun, Timothy J; Carrier, Lucie; Moon, James C

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is caused by mutations in sarcomeric proteins, the commonest being MYBPC3 encoding myosin-binding protein C. It is characterised by left ventricular hypertrophy but there is an important pre-hypertrophic phenotype with features including crypts, abnormal mitral leaflets and trabeculae. We investigated these during mouse cardiac development using high-resolution episcopic microscopy. In embryonic hearts from wildtype, homozygous (HO) and heterozygous (HET) Mybpc3-targeted knock-out (KO) mice we show that crypts (one or two) are a normal part of wildtype development but they almost all resolve by birth. By contrast, HO and HET embryos had increased crypt presence, abnormal mitral valve formation and alterations in the compaction process. In scarce normal human embryos, crypts were sometimes present. This study shows that features of the human pre-hypertrophic HCM phenotype occur in the mouse. In an animal model we demonstrate that there is an embryological HCM phenotype. Crypts are a normal part of cardiac development but, along with the mitral valve and trabeculae, their developmental trajectory is altered by the presence of HCM truncating Mybpc3 gene mutation. PMID:27323879

  5. Inflammation and cutaneous nervous system involvement in hypertrophic scarring

    PubMed Central

    Li, Shao-hua; Yang, Heng-lian; Xiao, Hu; Wang, Yi-bing; Wang, De-chang; Huo, Ran

    2015-01-01

    This study aimed to use a mouse model of hypertrophic scarring by mechanical loading on the dorsum of mice to determine whether the nervous system of the skin and inflammation participates in hypertrophic scarring. Results of hematoxylin-eosin and immunohistochemical staining demonstrated that inflammation contributed to the formation of a hypertrophic scar and increased the nerve density in scar tissue.Western blot assay verified that interleukin-13 expression was increased in scar tissue. These findings suggest that inflammation and the cutaneous nervous system play a role in hypertrophic scar formation. PMID:26692869

  6. Hypertrophic cardiomyopathy in a neonate associated with nemaline myopathy.

    PubMed

    Mir, Arshid; Lemler, Matthew; Ramaciotti, Claudio; Blalock, Shannon; Ikemba, Catherine

    2012-01-01

    Nemaline myopathy is a congenital nonprogressive skeletal muscle disorder with a characteristic rod body formation in the skeletal muscle fibers. Cardiac involvement in nemaline myopathy is rare, although both dilated and hypertrophic cardiomyopathy have been reported. We describe an infant diagnosed with hypertrophic cardiomyopathy and hypotonia on the first day of life. Muscle biopsy confirmed nemaline myopathy at 3 weeks of age. The diagnosis of nemaline myopathy precluded consideration of heart transplantation, thus shifting the focus to comfort care. This is the earliest presentation of hypertrophic cardiomyopathy reported in the literature in the setting of nemaline myopathy. The approach to determining an etiology for hypertrophic cardiomyopathy in an infant is reviewed. PMID:22067214

  7. Periostin induces fibroblast proliferation and myofibroblast persistence in hypertrophic scarring.

    PubMed

    Crawford, Justin; Nygard, Karen; Gan, Bing Siang; O'Gorman, David Brian

    2015-02-01

    Hypertrophic scarring is characterized by the excessive development and persistence of myofibroblasts. These cells contract the surrounding extracellular matrix resulting in the increased tissue density characteristic of scar tissue. Periostin is a matricellular protein that is abnormally abundant in fibrotic dermis, however, its roles in hypertrophic scarring are largely unknown. In this report, we assessed the ability of matrix-associated periostin to promote the proliferation and myofibroblast differentiation of dermal fibroblasts isolated from the dermis of hypertrophic scars or healthy skin. Supplementation of a thin type-I collagen cell culture substrate with recombinant periostin induced a significant increase in the proliferation of hypertrophic scar fibroblasts but not normal dermal fibroblasts. Periostin induced significant increases in supermature focal adhesion formation, α smooth muscle actin levels and collagen contraction in fibroblasts cultured from hypertrophic scars under conditions of increased matrix tension in three-dimensional type-I collagen lattices. Inhibition of Rho-associated protein kinase activity significantly attenuated the effects of matrix-associated periostin on hypertrophic scar fibroblasts and myofibroblasts. Depletion of endogenous periostin expression in hypertrophic scar myofibroblasts resulted in a sustained decrease in α smooth muscle actin levels under conditions of reducing matrix tension, while matrix-associated periostin levels caused the cells to retain high levels of a smooth muscle actin under these conditions. These findings indicate that periostin promotes Rho-associated protein kinase-dependent proliferation and myofibroblast persistence of hypertrophic scar fibroblasts and implicate periostin as a potential therapeutic target to enhance the resolution of scars.

  8. Topical modalities for treatment and prevention of postsurgical hypertrophic scars.

    PubMed

    Foo, Chong Wee; Tristani-Firouzi, Payam

    2011-08-01

    There is no universally accepted treatment regimen and no evidence-based literature to guide management of hypertrophic scars. This article summarizes the existing literature regarding topical treatments such as silicone gel sheeting and ointment, onion extract, vitamin E, pressure garment therapy, massage therapy, and topical imiquimod 5% cream in the management of hypertrophic scars.

  9. Topical modalities for treatment and prevention of postsurgical hypertrophic scars.

    PubMed

    Foo, Chong Wee; Tristani-Firouzi, Payam

    2011-08-01

    There is no universally accepted treatment regimen and no evidence-based literature to guide management of hypertrophic scars. This article summarizes the existing literature regarding topical treatments such as silicone gel sheeting and ointment, onion extract, vitamin E, pressure garment therapy, massage therapy, and topical imiquimod 5% cream in the management of hypertrophic scars. PMID:21856542

  10. Blepharoptosis and hypertrophic osteoarthropathy: A case report.

    PubMed

    Dogan, Aysun Sanal; Acaroglu, Gölge; Dikmetas, Ozlem

    2016-04-01

    A 52-year-old male patient presented to our hospital with a history of secondary hypertrophic osteoarthropathy (HOA) associated with an abdominal neoplasia and blepharoptosis. He had finger clubbing, hyperhidrosis, and hypertrichosis. He also had a recent history of extensive abdominal surgery with a pathology report of myelolipoma. Routine blood work was unremarkable. Upper eyelid reconstruction with blepharoplasty, upper eyelid wedge resection, and brow suspension was performed to address his eyelid concerns. By this case report, we would like to attract notice that the eyelid involvement may be a part of HOA and to emphasize the importance of systemic and pathologic evaluation in failed blepharoptosis surgery. PMID:27221686

  11. Screening for hypertrophic cardiomyopathy in cats.

    PubMed

    Häggström, Jens; Luis Fuentes, Virginia; Wess, Gerhard

    2015-12-01

    Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats, and it can lead to increased morbidity and mortality. Cats are often screened for HCM because of the presence of a heart murmur, but screening for breeding purposes has also become common. These cats are usually purebred cats of breeding age, and generally do not present with severe disease or with any clinical signs. This type of screening is particularly challenging because mild disease may be difficult to differentiate from a normal phenotype, and the margin for error is small, with potentially major consequences for the breeder. This article reviews HCM screening methods, with particular emphasis on echocardiography.

  12. Idiopathic Hypertrophic Pachymeningitis in the Craniocervical Junction

    PubMed Central

    Bang, Jin Hyuk; Kim, Eo Jin

    2015-01-01

    Idiopathic hypertrophic pachymeningitis (IHP) is a rare disease, and it is characterized by chronic progressive inflammatory fibrosis and thickening of the dura mater with resultant compression of the spinal cord or neural structure without any identifiable cause. It can occur in the intracranial or spinal dura mater alone or as a craniospinal form. The spinal form is rarer than the cranial form and the craniospinal form is extremely rare. We report a rare case of IHP in the craniocervical junction involving both the cranial and spinal dura mater and discuss the diagnosis and management of the disease. PMID:26512276

  13. Blepharoptosis and hypertrophic osteoarthropathy: A case report

    PubMed Central

    Doğan, Aysun Şanal; Acaroğlu, Gölge; Dikmetas, Ozlem

    2016-01-01

    A 52-year-old male patient presented to our hospital with a history of secondary hypertrophic osteoarthropathy (HOA) associated with an abdominal neoplasia and blepharoptosis. He had finger clubbing, hyperhidrosis, and hypertrichosis. He also had a recent history of extensive abdominal surgery with a pathology report of myelolipoma. Routine blood work was unremarkable. Upper eyelid reconstruction with blepharoplasty, upper eyelid wedge resection, and brow suspension was performed to address his eyelid concerns. By this case report, we would like to attract notice that the eyelid involvement may be a part of HOA and to emphasize the importance of systemic and pathologic evaluation in failed blepharoptosis surgery. PMID:27221686

  14. Twice malignant transformation of hypertrophic lichen planus.

    PubMed

    Krasowska, Dorota; Kozłowicz, Katarzyna; Kowal, Małgorzata; Kurylcio, Andrzej; Budzyńska-Włodarczyk, Jolanta; Polkowski, Wojciech; Chodorowska, Grażyna

    2012-01-01

    Lichen planus is a chronic mucocutaneous T-cell-mediated disease, the cause of which remains unknown. The first case of lichen planus that transformed into squamous cell carcinoma was reported in 1903. The presented study concerns the case of a 62-year-old woman in whom twice malignant transformation of hypertrophic lichen planus in the dorsal part of the left foot developed. Several studies have pointed out the malignant transformation potential of lichen planus. Epidemiological studies from the last 20 years have revealed a malignant transformation rate of 0.27% per year, emphasizing the importance of the clinical follow-up of lichen planus patients.

  15. RADIAL STABILITY IN STRATIFIED STARS

    SciTech Connect

    Pereira, Jonas P.; Rueda, Jorge A. E-mail: jorge.rueda@icra.it

    2015-03-01

    We formulate within a generalized distributional approach the treatment of the stability against radial perturbations for both neutral and charged stratified stars in Newtonian and Einstein's gravity. We obtain from this approach the boundary conditions connecting any two phases within a star and underline its relevance for realistic models of compact stars with phase transitions, owing to the modification of the star's set of eigenmodes with respect to the continuous case.

  16. Hypertrophic cardiomyopathy in owl monkeys (Aotus spp.).

    PubMed

    Knowlen, Grant G; Weller, Richard E; Perry, Ruby L; Baer, Janet F; Gozalo, Alfonso S

    2013-06-01

    Cardiac hypertrophy is a common postmortem finding in owl monkeys. In most cases the animals do not exhibit clinical signs until the disease is advanced, making antemortem diagnosis of subclinical disease difficult and treatment unrewarding. We obtained echocardiograms, electrocardiograms, and thoracic radiographs from members of a colony of owl monkeys that previously was identified as showing a 40% incidence of gross myocardial hypertrophy at necropsy, to assess the usefulness of these modalities for antemortem diagnosis. No single modality was sufficiently sensitive and specific to detect all monkeys with cardiac hypertrophy. Electrocardiography was the least sensitive method for detecting owl monkeys with hypertrophic cardiomyopathy. Thoracic radiographs were more sensitive than was electrocardiography in this context but cannot detect animals with concentric hypertrophy without an enlarged cardiac silhouette. Echocardiography was the most sensitive method for identifying cardiac hypertrophy in owl monkeys. The most useful parameters suggestive of left ventricular hypertrophy in our owl monkeys were an increased average left ventricular wall thickness to chamber radius ratio and an increased calculated left ventricular myocardial mass. Parameters suggestive of dilative cardiomyopathy were an increased average left ventricular myocardial mass and a decreased average ratio of left ventricular free wall thickness to left ventricular chamber radius. When all 4 noninvasive diagnostic modalities (physical examination, echocardiography, electrocardiography, and thoracic radiography) were used concurrently, the probability of detecting hypertrophic cardiomyopathy in owl monkeys was increased greatly.

  17. Cushing's syndrome in pregnancy and neonatal hypertrophic obstructive cardiomyopathy.

    PubMed

    Fayol, L; Masson, P; Millet, V; Simeoni, U

    2004-10-01

    Cushing's syndrome is rare in pregnancy but can cause spontaneous abortion, stillbirth or premature birth. We report a case of transient hypertrophic obstructive cardiomyopathy in a newborn whose mother had hypercortisolism due to a primary adrenal lesion. There was no family history of hypertrophic obstructive cardiomyopathy. Follow-up revealed complete resolution of the cardiac abnormalities in the infant. Cushing's syndrome in the mother resolved after delivery. Although maternal hypercortisolism seldom results in symptomatic hypercortisolism in the newborn, hypertrophic obstructive cardiomyopathy can occur. PMID:15499965

  18. Internal waves in the systems of stratified currents

    NASA Astrophysics Data System (ADS)

    Samolyubov, B. I.

    2009-04-01

    The system of stratified currents is a composition of flows (circulating, near-bottom, intermediate) developed at different depths and interacting to each other. Internal waves that usually present at such currents substantially influence both on dynamics of single flows (due to the action on their trajectories and thicknesses) and on the processes of interaction between currents in the systems. Such systems quite often include currents, directly caused by internal seiches. The investigations of systems of stratified currents with internal waves are inseparably linked with hydroecological and other problems of a great practical importance. The presented results are obtained during the investigations of the systems of stratified currents in Lakes Teletskoye (Gorny Altai, Russia) and Onega (Karelia, Russia) in 2006-2008. There are analyzed the following systems: 1) density current - jet - flow current at Teletskoye Lake and 2) circulating current - jet - near-bottom current at Lake Onega. The purposes of this work include: the revelation of mechanisms of the evolution of systems of stratified currents with internal waves, as well as of regularities of currents influence on the transfer of suspended sediments and dissolved salts. At Teletskoye Lake there were revealed mechanisms of jet-type stratified currents with topographical disturbances. Such currents were registered while overflow of higher density waters through the under-water sill and further over the entire area of their propagation above the complex bottom relief. The current under investigation was caused by water entrance from the deepwater part of the lake (with depth up to 325 m) into the shallow part and further to river Biya outflow. Problems of this current theoretical description are stipulated by its complex nature. It is formed while transition of the intermediate jet, sinking along the prominent isopicnical surface before the sill into the stratified current above the sill. The prominent

  19. The molecular basis of hypertrophic scars.

    PubMed

    Zhu, Zhensen; Ding, Jie; Tredget, Edward E

    2016-01-01

    Hypertrophic scars (HTS) are caused by dermal injuries such as trauma and burns to the deep dermis, which are red, raised, itchy and painful. They can cause cosmetic disfigurement or contractures if craniofacial areas or mobile region of the skin are affected. Abnormal wound healing with more extracellular matrix deposition than degradation will result in HTS formation. This review will introduce the physiology of wound healing, dermal HTS formation, treatment and difference with keloids in the skin, and it also review the current advance of molecular basis of HTS including the involvement of cytokines, growth factors, and macrophages via chemokine pathway, to bring insights for future prevention and treatment of HTS. PMID:27574672

  20. Stratified medicine for mental disorders.

    PubMed

    Schumann, Gunter; Binder, Elisabeth B; Holte, Arne; de Kloet, E Ronald; Oedegaard, Ketil J; Robbins, Trevor W; Walker-Tilley, Tom R; Bitter, Istvan; Brown, Verity J; Buitelaar, Jan; Ciccocioppo, Roberto; Cools, Roshan; Escera, Carles; Fleischhacker, Wolfgang; Flor, Herta; Frith, Chris D; Heinz, Andreas; Johnsen, Erik; Kirschbaum, Clemens; Klingberg, Torkel; Lesch, Klaus-Peter; Lewis, Shon; Maier, Wolfgang; Mann, Karl; Martinot, Jean-Luc; Meyer-Lindenberg, Andreas; Müller, Christian P; Müller, Walter E; Nutt, David J; Persico, Antonio; Perugi, Giulio; Pessiglione, Mathias; Preuss, Ulrich W; Roiser, Jonathan P; Rossini, Paolo M; Rybakowski, Janusz K; Sandi, Carmen; Stephan, Klaas E; Undurraga, Juan; Vieta, Eduard; van der Wee, Nic; Wykes, Til; Haro, Josep Maria; Wittchen, Hans Ulrich

    2014-01-01

    There is recognition that biomedical research into the causes of mental disorders and their treatment needs to adopt new approaches to research. Novel biomedical techniques have advanced our understanding of how the brain develops and is shaped by behaviour and environment. This has led to the advent of stratified medicine, which translates advances in basic research by targeting aetiological mechanisms underlying mental disorder. The resulting increase in diagnostic precision and targeted treatments may provide a window of opportunity to address the large public health burden, and individual suffering associated with mental disorders. While mental health and mental disorders have significant representation in the "health, demographic change and wellbeing" challenge identified in Horizon 2020, the framework programme for research and innovation of the European Commission (2014-2020), and in national funding agencies, clear advice on a potential strategy for mental health research investment is needed. The development of such a strategy is supported by the EC-funded "Roadmap for Mental Health Research" (ROAMER) which will provide recommendations for a European mental health research strategy integrating the areas of biomedicine, psychology, public health well being, research integration and structuring, and stakeholder participation. Leading experts on biomedical research on mental disorders have provided an assessment of the state of the art in core psychopathological domains, including arousal and stress regulation, affect, cognition social processes, comorbidity and pharmacotherapy. They have identified major advances and promising methods and pointed out gaps to be addressed in order to achieve the promise of a stratified medicine for mental disorders. PMID:24176673

  1. Sedimentation dynamics of disks in a linearly stratified fluid

    NASA Astrophysics Data System (ADS)

    Mercier, Matthieu; Pemeja, Justin; Ern, Patricia

    2014-11-01

    The settling dynamics of small objects in a stratified fluid is important to understand the fate of the biomass in lakes or oceanic environments, for industrial applications such as waste-water disposal for instance. Recent numerical and theoretical studies dedicated to freely falling (or rising) bodies in stratified environments have shown some important differences compared to the same problem in a homogeneous fluid. Experimental results are still needed for validation, especially at low and moderate values of the Reynolds number, Re = Ud / ν <= 100 , with U the instantaneous vertical velocity of the object, d its characteristic length, and ν the kinematic velocity of the fluid. We present original experimental results of freely falling disks of finite thickness in a linearly stratified fluid. Three-dimensional trajectories and the wake of the object are obtained using a pair of cameras visualizing two perpendicular planes, revealing a strong influence of the stratification on the dynamics of the object. In particular, the stratification enhances the steady drag experienced by the disks when falling broadside; and generates a change of stability for the disk orientation (from horizontal to vertical) when the Re number decreases below a threshold value.

  2. Vortex trails in stratified fluids

    NASA Astrophysics Data System (ADS)

    Pao, H.-P.; Lai, R. Y.; Schemm, C. E.

    1982-03-01

    A framework is proposed which accounts for the properties of atmospheric vortex trails used by wind flow. Similarities between atmospheric vortex patterns and those in stratified fluids are observed noting that the generation of vortex trails is primarily due to density stratification. Horizontal vortices form for values of Froude numbers between 2-505, and for Reynolds numbers between 600-100,000. The cause of late-wake vortices and the reason for their great regularity is the presence of a large-scale coherent structure in the early wake. A critical Froude number exists above which no horizontal vortices form and its value for a bluff body is about 160. Finally, it is also noted that ambient shear can prevent or destroy late-wake horizontal vortices.

  3. Broadband cloaking in stratified seas.

    PubMed

    Alam, Mohammad-Reza

    2012-02-24

    Here we show that floating objects in stratified fluids can be cloaked against broadband incident waves by properly architecting the bottom corrugations. The presented invisibility cloaking of gravity waves is achieved utilizing a nonlinear resonance concept that occurs between surface and internal waves mediated by the bottom topography. Our cloak bends wave rays from the surface into the body of the fluid. Wave rays then pass underneath the floating object and may be recovered back to the free surface at the downstream bearing no trace of diffraction or scattering. The cloak is the proper architecture of bottom corrugations only, and hence is surface noninvasive. The presented scheme is a nonlinear alternative to the transformation-based cloaking, but in the context of dispersive waves.

  4. Inhibited early immunologic response is associated with hypertrophic scarring.

    PubMed

    Butzelaar, Liselotte; Schooneman, Dennis P M; Soykan, Ezgi A; Talhout, Wendy; Ulrich, Magda M W; van den Broek, Lenie J; Gibbs, Susan; Beelen, Robert H J; Mink van der Molen, Aebele B; Niessen, Frank B

    2016-10-01

    This study aimed to examine changes in the inflammatory response in early hypertrophic compared to normal wound healing. The immune system is thought to be involved in hypertrophic scar formation. However, the exact mechanism and time of onset of the derailment remain unknown. In a prospective observational study, skin biopsies were taken directly postwounding and 3 hours later from patients who had elective cardiothoracic surgery. The skin biopsies were analysed for mRNA, proteins and cells involved in the early inflammatory phase of wound healing. The endpoint was scar outcome (hypertrophic (HTS) or normal (NTS)) at one year after surgery. There were significant differences between the NTS and HTS groups regarding the fold changes of mRNA expression of P-selectin during surgery. Postoperative skin concentrations of inflammatory proteins IL-6, IL-8 and CCL2 were significantly lower in the HTS compared to the NTS group. Also, a trend of higher pre-operative M2 macrophage numbers was observed in the HTS group. Neutrophil numbers increased equally during surgery in both groups. The increase of P-selectin mRNA in hypertrophic wound healing could affect leucocyte migration. The decreased concentrations of inflammatory proteins in hypertrophic wound healing indicate a reduced inflammatory response, which has consequences for the treatment of hypertrophic scarring during the early inflammatory phase. In a conclusion, alterations of wound healing associated with hypertrophic scarring are visible as early as 3 hours postwounding and include a reduced rather than increased inflammatory protein response. PMID:27249786

  5. Oxygenation of Stratified Reservoir Using Air Bubble Plume

    NASA Astrophysics Data System (ADS)

    Schladow, S. G.

    2006-12-01

    Excess nutrients loading from urban area and watershed into lakes and reservoirs increases the content of organic matter, which, through decomposition, needs increased dissolve oxygen (DO). Many eutrophic reservoirs and lakes cannot meet the DO requirement during stratified season and suffers from the hypolimnetic anoxia. As a result, benthic sediment produces anoxic products such as methane, hydrogen sulphide, ammonia, iron, manganese, and phosphorus. In order to address the hypolimnetic anoxia, oxygen is artificially supplied into reservoir using an aeration system (i.e., bubbler). The most common result of lake/reservoir aeration is to destratify the reservoir so that the water body may completely mix under natural phenomena and remain well oxygenated throughout. Other advantages of destratification are: (1) allows warm- water fish to inhabit the entire reservoir, (2) suppress the nutrient release from sediment, and (3) decreases the algal growth by sending them to the darker zone. A one-dimensional reservoir-bubbler model is developed and applied to examine the effects of an aeration system on mixing and dissolved oxygen dynamics in the Upper Peirce Reservoir, Singapore. After introduction of the aeration system in the reservoir, it was found that the hypolimnetic DO increased significantly, and the concentration of algae, soluble manganese and iron substantially reduced. It is found that the reservoir-bubbler model predicts the mixing (temperature as mixing parameter) and dissolved oxygen concentration in the reservoir with acceptable accuracy. It is shown in terms of bubbler mechanical efficiency (i.e., operating cost) and total DO contribution from the aeration system into the reservoir that the selections of airflow rate per diffuser, air bubble radius, and total number of diffusers are important design criteria of a bubbler system. However, the overall bubbler design also depends on the reservoir size and stratified area of interest, ambient climate, and

  6. Paraneoplastic hypertrophic osteopathy in 30 dogs

    PubMed Central

    Withers, S. S.; Johnson, E. G.; Culp, W. T. N.; Rodriguez, C. O.; Skorupski, K. A.; Rebhun, R. B.

    2016-01-01

    Paraneoplastic hypertrophic osteopathy (pHO) is known to occur in both canine and human cancer patients. While the pathology of pHO is well-described in the dog, very little information exists regarding the true clinical presentation of dogs affected with pHO. The primary objective of this study was to provide a more comprehensive clinical picture of pHO. To this end, we retrospectively identified 30 dogs and recorded data regarding presenting complaints and physical examination (PE) findings on the date of pHO diagnosis. As a secondary objective, any blood test results were also collected from the computerized records. The most common clinical signs included leg swelling, ocular discharge and/or episcleral injection, lameness, and lethargy. The most common haematological and serum biochemical abnormalities included anaemia, neutrophilia and elevated alkaline phosphatase. In addition to presenting a more detailed clinical description of pHO in the dog, these data support the previously described haematological, serum biochemical and PE abnormalities published in individual case reports. PMID:23489591

  7. Hypertrophic olivary degeneration secondary to pontine haemorrhage.

    PubMed

    Wein, Sara; Yan, Bernard; Gaillard, Frank

    2015-07-01

    We report a 58-year-old man who developed hyptertrophic olivary degeneration (HOD) after haemorrhage of a cavernous malformation in the pons. Lesions of the triangle of Guillain and Mollaret (the dentatorubro-olivary pathway) may lead to HOD, a secondary transsynaptic degeneration of the inferior olivary nucleus. HOD is considered unique because the degenerating olive initially becomes hypertrophic rather than atrophic. The primary lesion causing pathway interruption is often haemorrhage, either due to hypertension, trauma, surgery or, as in our patient, a vascular malformation such as a cavernoma. Ischaemia and demyelination can also occasionally be the inciting events. The classic clinical presentation of HOD is palatal myoclonus, although not all patients with HOD develop this symptom. The imaging features of HOD evolve through characteristic phases. The clue to the diagnosis of HOD is recognition of the distinct imaging stages and identification of a remote primary lesion in the triangle of Guillain and Mollaret. Familiarity with the classic imaging findings of this rare phenomenon is necessary in order to avoid misdiagnosis and prevent unnecessary intervention.

  8. PHOTOSPHERIC EMISSION FROM STRATIFIED JETS

    SciTech Connect

    Ito, Hirotaka; Nagataki, Shigehiro; Ono, Masaomi; Lee, Shiu-Hang; Mao, Jirong; Yamada, Shoichi; Pe'er, Asaf; Mizuta, Akira; Harikae, Seiji

    2013-11-01

    We explore photospheric emissions from stratified two-component jets, wherein a highly relativistic spine outflow is surrounded by a wider and less relativistic sheath outflow. Thermal photons are injected in regions of high optical depth and propagated until the photons escape at the photosphere. Because of the presence of shear in velocity (Lorentz factor) at the boundary of the spine and sheath region, a fraction of the injected photons are accelerated using a Fermi-like acceleration mechanism such that a high-energy power-law tail is formed in the resultant spectrum. We show, in particular, that if a velocity shear with a considerable variance in the bulk Lorentz factor is present, the high-energy part of observed gamma-ray bursts (GRBs) photon spectrum can be explained by this photon acceleration mechanism. We also show that the accelerated photons might also account for the origin of the extra-hard power-law component above the bump of the thermal-like peak seen in some peculiar bursts (e.g., GRB 090510, 090902B, 090926A). We demonstrate that time-integrated spectra can also reproduce the low-energy spectrum of GRBs consistently using a multi-temperature effect when time evolution of the outflow is considered. Last, we show that the empirical E{sub p}-L{sub p} relation can be explained by differences in the outflow properties of individual sources.

  9. Photospheric Emission from Stratified Jets

    NASA Astrophysics Data System (ADS)

    Ito, Hirotaka; Nagataki, Shigehiro; Ono, Masaomi; Lee, Shiu-Hang; Mao, Jirong; Yamada, Shoichi; Pe'er, Asaf; Mizuta, Akira; Harikae, Seiji

    2013-11-01

    We explore photospheric emissions from stratified two-component jets, wherein a highly relativistic spine outflow is surrounded by a wider and less relativistic sheath outflow. Thermal photons are injected in regions of high optical depth and propagated until the photons escape at the photosphere. Because of the presence of shear in velocity (Lorentz factor) at the boundary of the spine and sheath region, a fraction of the injected photons are accelerated using a Fermi-like acceleration mechanism such that a high-energy power-law tail is formed in the resultant spectrum. We show, in particular, that if a velocity shear with a considerable variance in the bulk Lorentz factor is present, the high-energy part of observed gamma-ray bursts (GRBs) photon spectrum can be explained by this photon acceleration mechanism. We also show that the accelerated photons might also account for the origin of the extra-hard power-law component above the bump of the thermal-like peak seen in some peculiar bursts (e.g., GRB 090510, 090902B, 090926A). We demonstrate that time-integrated spectra can also reproduce the low-energy spectrum of GRBs consistently using a multi-temperature effect when time evolution of the outflow is considered. Last, we show that the empirical E p-L p relation can be explained by differences in the outflow properties of individual sources.

  10. Core science: Stratified by a sunken impactor

    NASA Astrophysics Data System (ADS)

    Nakajima, Miki

    2016-10-01

    There is potential evidence for a stratified layer at the top of the Earth's core, but its origin is not well understood. Laboratory experiments suggest that the stratified layer could be a sunken remnant of the giant impact that formed the Moon.

  11. Medicinal Plants for the Treatment of Hypertrophic Scars

    PubMed Central

    Ye, Qi; Wang, Su-Juan; Chen, Jian-Yu; Xin, Hai-Liang; Zhang, Hong

    2015-01-01

    Hypertrophic scar is a complication of wound healing and has a high recurrence rate which can lead to significant abnormity in aesthetics and functions. To date, no ideal treatment method has been established. Meanwhile, the underlying mechanism of hypertrophic scarring has not been clearly defined. Although a large amount of scientific research has been reported on the use of medicinal plants as a natural source of treatment for hypertrophic scarring, it is currently scattered across a wide range of publications. Therefore, a systematic summary and knowledge for future prospects are necessary to facilitate further medicinal plant research for their potential use as antihypertrophic scar agents. A bibliographic investigation was accomplished by focusing on medicinal plants which have been scientifically tested in vitro and/or in vivo and proved as potential agents for the treatment of hypertrophic scars. Although the chemical components and mechanisms of action of medicinal plants with antihypertrophic scarring potential have been investigated, many others remain unknown. More investigations and clinical trials are necessary to make use of these medical plants reasonably and phytotherapy is a promising therapeutic approach against hypertrophic scars. PMID:25861351

  12. Hypertrophic scarring: the greatest unmet challenge after burn injury.

    PubMed

    Finnerty, Celeste C; Jeschke, Marc G; Branski, Ludwik K; Barret, Juan P; Dziewulski, Peter; Herndon, David N

    2016-10-01

    Improvements in acute burn care have enabled patients to survive massive burns that would have once been fatal. Now up to 70% of patients develop hypertrophic scars after burns. The functional and psychosocial sequelae remain a major rehabilitative challenge, decreasing quality of life and delaying reintegration into society. Approaches to optimise healing potential of burn wounds use targeted wound care and surgery to minimise the development of hypertrophic scarring. Such approaches often fail, and modulation of the established scar is continued although the optimal indication, timing, and combination of therapies have yet to be established. The need for novel treatments is paramount, and future efforts to improve outcomes and quality of life should include optimisation of wound healing to attenuate or prevent hypertrophic scarring, well-designed trials to confirm treatment efficacy, and further elucidation of molecular mechanisms to allow development of new preventive and therapeutic strategies.

  13. Hypertrophic olivary degeneration and cerebrovascular disease: movement in a triangle.

    PubMed

    Santos, Ana Filipa; Rocha, Sofia; Varanda, Sara; Pinho, João; Rodrigues, Margarida; Ramalho Fontes, João; Soares-Fernandes, João; Ferreira, Carla

    2015-02-01

    Hypertrophic olivary degeneration is a rare kind of trans-synaptic degeneration that occurs after lesions of the dentatorubro-olivary pathway. The lesions, commonly unilateral, may result from hemorrhage due to vascular malformation, trauma, surgical intervention or hypertension, tumor, or ischemia. Bilateral cases are extremely rare. This condition is classically associated with development of palatal tremor, but clinical manifestations can include other involuntary movements. We describe 2 cases: unilateral hypertrophic olivary degeneration in a 60-year-old man with contralateral athetosis and neurologic worsening developing several years after a pontine hemorrhage and bilateral hypertrophic olivary degeneration in a 77-year-old woman with development of palatal tremor, probably secondary to pontine ischemic lesions (small vessel disease).

  14. [Scarlet fever with multisystem organ failure and hypertrophic gastritis].

    PubMed

    Sandrini, J; Beucher, A-B; Kouatchet, A; Lavigne, C

    2009-05-01

    Scarlet fever is a rare disease in adult patients. We report a patient in whom scarlet fever was associated with hypertrophic gastritis and multiple organ failure. A 62-year-old woman presented with septic shock and multiple organ failure. Bacteriological survey was negative. Abdominal tomodensitometry showed an hypertrophic gastritis. Histological analysis demonstrated a non specific gastritis without any tumoral sign. Cefotaxime and amoxicillin led to improvement and hypertrophic gastritis progressively resolved. A sandpaper rash over the body with finger desquamation, elevation of antistreptolysin O and a recent contact with an infected grandson led to the diagnosis of scarlet fever. Due to antibiotic prescription, scarlet fever is now uncommon. Although classical, ENT or gastroenteritis presentations may be puzzling for the diagnosis of scarlet fever. As 150 years ago, diagnosis of scarlet fever is still a clinical challenge.

  15. Echocardiography in the treatment of hypertrophic cardiomyopathy.

    PubMed

    Musat, Dan; Sherrid, Mark V

    2006-12-01

    Echocardiography is the best technique to diagnose, evaluate, follow-up and guide the treatment of hypertrophic cardiomyopathy (HCM). Diagnosis of HCM depends on left ventricular wall thickness >/=15 mm. Also noted are mitral valve systolic anterior motion, anteriorly positioned mitral valve leaflet coaptation, anomalous anterior insertion of papillary muscles, and diastolic dysfunction. Resting left ventricular outflow tract (LVOT) gradient occurs in 25% of patients and provocable gradients may be demonstrated in more than half of patients. Echocardiography is important for sudden death risk assessment; patients with a wall thickness more than 30 mm have a higher risk of sudden cardiac death, as often as 2%/year. Two thirds of the symptomatic obstructed patients can be successfully managed long term with medical treatment alone (beta-blockers, disopyramide, verapamil) guided by transthoracic echocardiography (TTE) response and follow-up. Obstructed patients, who fail medical therapy, are usually offered invasive treatment: surgical septal myectomy, alcohol septal ablation, or DDD pacemaker. Preoperative TTE is a necessary guide for the surgeon in planning the operation. It gives the surgeon precise measurements of septal thickness, mitral valve leaflets length and floppiness and papillary muscle anomalies. Intraoperative transesophageal echocardiography is a very important tool for evaluating surgical results. Persistent SAM, resting outflow gradient more than 30 mm Hg or more than 50 mmHg with provocation, moderate to severe mitral regurgitation are indications for immediate revision. For patients >40 years old, and also not suitable for surgery because of comorbidities, alcohol septal ablation is viable alternative therapy for relief of obstruction and improvement of symptoms. Echocardiography is a valuable tool to choose the site of ablation (using myocardial contrast echocardiography), as well as for evaluation of results.

  16. The epidemiology of infantile hypertrophic pyloric stenosis.

    PubMed

    Schechter, R; Torfs, C P; Bateson, T F

    1997-10-01

    Infants with infantile hypertrophic pyloric stenosis (IHPS) born from 1983 to 1988 and recorded in the California Birth Defects Monitoring Program (CBDMP) database were compared with their birth cohort by demographic characteristics and selected associated birth defects. We identified 1963 cases of IHPS for a cumulative incidence of 1.9 per 1000 livebirths. The cumulative incidence per 1000 livebirths was 2.4 in White, 1.8 in Hispanic, 0.7 in Black, and 0.6 in Asian infants. Between weeks 3-12 after birth, 1871 (95%) IHPS cases were diagnosed. Premature infants were diagnosed with IHPS later than term or post-term infants. The incidence of IHPS declined for those born to maternal age groups of > or = 25 years and, independently, for successive birth ranks. The probandwise concordance rate for IHPS in monozygous twins was less than unity (0.25-0.44), although higher than the concordance for dizygous twins (0.05-0.10). The incidence of Smith-Lemli-Opitz syndrome (SLO) diagnosed in infants with IHPS (3 of 1963) was 157-fold higher than the incidence of SLO diagnosed in the CBDMP population. IHPS occurs in all of the largest racial and ethnic groups in California, most frequently in White and Hispanic infants. Pyloric stenosis presents only within a brief phase of development, which may be delayed in premature infants. A predominant discordance of disease state in monozygous twins implies an aetiological role for undetermined environmental factors. The association between SLO, caused by deficient cholesterol synthesis, and IHPS deserves additional study. Infants with suspected SLO require close observation for the onset of IHPS.

  17. Surviving competitive athletics with hypertrophic cardiomyopathy.

    PubMed

    Maron, B J; Klues, H G

    1994-06-01

    Hypertrophic cardiomyopathy (HC) is probably the most common cause of sudden cardiac death in youthful athletes, and this diagnosis has represented a contraindication to continued participation in competitive sports. Less well appreciated is the fact that within the clinical spectrum of HC are patients who, despite having this disease, have been able to undertake particularly intensive and often extraordinary levels of training for sports competition over many years without dying suddenly. Fourteen such patients (13 men and 1 woman, aged 30 to 66 years [mean 43]) form the present study group. HC was initially identified at 24 to 57 years of age (mean 34), usually under fortuitous circumstances. Patients most often competed in distance running (including the marathon, 7), but also in swimming, triathalon, basketball, and football. The duration of training ranged from 6 to 22 years (mean 15) and 5 continue to train and compete actively. The magnitude of training, competition, and achievement was considerable in most patients; 12 of the 14 performed either at the national, collegiate or professional level in their sport, completed numerous marathon and triathalon events, or sustained particularly rigorous training regimens of > or = 50 miles/week. Echocardiographic studies demonstrated a left ventricular wall thickness of 18 to 28 mm (mean 20) in most patients (12 of 14) having a relatively localized pattern of ventricular septal hypertrophy. It is possible for some patients with HC to tolerate particularly intense athletic training and competition for many years, and even maintain high levels of achievement without incurring symptoms and disease progression or dying suddenly.(ABSTRACT TRUNCATED AT 250 WORDS)

  18. [Hypertrophic scars and keloids: which therapeutic options today?].

    PubMed

    Gailloud-Matthieu, M C; Raffoul, W; Egloff, D V

    1999-09-01

    Hypertrophic scars and keloids are a hyperproliferative response of connective tissue to trauma. Histologically the difference between the two is that keloids invade normal tissue whereas hypertrophic scars remain confined within the original wound. A variety of treatments have been proposed, which we will review according to their efficiency. Prevention of pathological scarring will also be discussed, and we will present our current attitude to treat these scars. As a surgical treatment for keloids, we have been using the intralesional technique which we think gives better results.

  19. Familial idiopathic hypertrophic osteoarthropathy and cranial suture defects in children

    SciTech Connect

    Reginato, A.J.; Schiapachasse, V.; Guerrero, R.

    1982-05-01

    Three children with idiopathic hypertrophic osteoarthropathy and cranial suture defects are reported. The syndrome was recognized after birth and in the two oldest siblings, the cranial defects and subperiosteal bone formation resolved almost completely by age 4 and 6 years. The joint swelling and clubbing persisted and mild bone reabsorption of the distal phalanges became apparent at an older age. Two siblings and both parents had normal bone X-rays and no clubbing. This study confirms the association of cranial sutural defects and familial idopathic hypertrophic osteoarthropathy.

  20. Hypertrophic cardiomyopathy. Tools for identifying risk and alleviating symptoms.

    PubMed

    DeLuca, M; Tak, T

    2000-06-01

    Hypertrophic cardiomyopathy is characterized by left or right ventricular hypertrophy that is usually asymmetric and involves the interventricular septum. The condition has numerous genetic, anatomic, and clinical variations and continues to stimulate interest and investigation into causes and treatment options. New genetic forms of the disorder are being identified because of the rapid growth of molecular genetics. However, even with technological advances and a large database of information, risk stratification and treatment of hypertrophic cardiomyopathy remain difficult and controversial. Because of the high risk of sudden death, it is imperative that patients be advised against participation in competitive sports.

  1. Dynamics of CFCs in northern temperate lakes and adjacent groundwater

    USGS Publications Warehouse

    Walker, J.F.; Saad, D.A.; Hunt, R.J.

    2007-01-01

    [1] Three dimictic lakes and one meromictic lake in and near the Trout Lake, Wisconsin, watershed were sampled to determine the variation of chlorofluorocarbon (CFC) concentrations within the lakes. The lakes were sampled during stratified conditions, during fall turnover, and during ice cover. The results demonstrate a considerable variation in CFC concentrations and corresponding atmospheric mixing ratios in the lakes sampled, both with depth and season within a given lake, and across different lakes. CFC profiles and observed degradation were not related to the groundwater inflow rate and hence are likely the result of in-lake processes influenced by CFC degradation in the (lake) water column, CFC degradation in the lake-bed sediments, and gas exchange rates and the duration of turnover (turnover efficiency).

  2. How stratified is mantle convection?

    NASA Astrophysics Data System (ADS)

    Puster, Peter; Jordan, Thomas H.

    1997-04-01

    due to slabs alone. A stratification index, Sƒ≲0.2, is sufficient to exclude many stratified convection models still under active consideration, including most forms of chemical layering between the upper and lower mantle, as well as the more extreme versions of avalanching convection governed by a strong endothermic phase change.

  3. Waves in Turbulent Stably Stratified Shear Flow

    NASA Technical Reports Server (NTRS)

    Jacobitz, F. G.; Rogers, M. M.; Ferziger, J. H.; Parks, John W. (Technical Monitor)

    2002-01-01

    Two approaches for the identification of internal gravity waves in sheared and unsheared homogeneous stratified turbulence are investigated. First, the phase angle between the vertical velocity and density fluctuations is considered. It was found, however, that a continuous distribution of the phase angle is present in weakly and strongly stratified flow. Second, a projection onto the solution of the linearized inviscid equations of motion of unsheared stratified flow is investigated. It was found that a solution of the fully nonlinear viscous Navier-Stokes equations can be represented by the linearized inviscid solution. The projection yields a decomposition into vertical wave modes and horizontal vortical modes.

  4. [Left ventricular hypertrophy in the cat - "when hypertrophic cardiomyopathy is not hypertrophic cardiomyopathy"].

    PubMed

    Glaus, T; Wess, G

    2010-07-01

    According to WHO classification hypertrophic cardiomyopathy (HCM) is a primary genetic cardiomyopathy. Echocardiographically HCM is characterized by symmetric, asymmetric or focal left ventricular hypertrophy (LVH) without recognizable underlying physical cause. However, echocardiographically HCM in cats may not be distinguishable from other causes of a thick appearing left ventricle. Hypovolemia can look like a hypertrophied ventricle but is basically only pseudohypertrophic. Well recognized and logical physical causes of LVH include systemic hypertension and outflow obstruction. LVH similar to HCM may also be found in feline hyperthyroidism. The context of the disease helps to differentiate these physical / physiological causes of LVH. Difficult to distinguish from HCM, particularly when based on a snapshot of a single echocardiographic exam, are myocarditis and . Only the clinical and echocardiographic course allow a reasonably confident etiological diagnosis and the differentiation between HCM and secondary LVH. PMID:20582898

  5. Lake Life.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This quarterly publication of the State Historical Society of Iowa features articles and activities for elementary school students. This summer issue focuses on the topic of lake life. The issue includes the following features: (1) "Where the Lakes Are Map"; (2) "Letter from the Lake"; (3) "Lake People"; (4) "Spirit Lake"; (5) "Lake Manawa"; (6)…

  6. Process of Hypertrophic Scar Formation: Expression of Eukaryotic Initiation Factor 6

    PubMed Central

    Yang, Qing-Qing; Yang, Si-Si; Tan, Jiang-Lin; Luo, Gao-Xing; He, Wei-Feng; Wu, Jun

    2015-01-01

    Background: Hypertrophic scar is one of the most common complications and often causes the disfigurement or deformity in burn or trauma patients. Therapeutic methods on hypertrophic scar treatment have limitations due to the poor understanding of mechanisms of hypertrophic scar formation. To throw light on the molecular mechanism of hypertrophic scar formation will definitely improve the outcome of the treatment. This study aimed to illustrate the negative role of eukaryotic initiation factor 6 (eIF6) in the process of human hypertrophic scar formation, and provide a possible indicator of hypertrophic scar treatment and a potential target molecule for hypertrophic scar. Methods: In the present study, we investigated the protein expression of eIF6 in the human hypertrophic scar of different periods by immunohistochemistry and Western blot analysis. Results: In the hypertrophic scar tissue, eIF6 expression was significantly decreased and absent in the basal layer of epidermis in the early period, and increased slowly and began to appear in the basal layer of epidermis by the scar formation time. Conclusions: This study confirmed that eIF6 expression was significantly related to the development of hypertrophic scar, and the eIF6 may be a target molecule for hypertrophic scar control or could be an indicator of the outcomes for other treatment modalities. PMID:26481747

  7. Hypertrophic Osteoarthropathy Presenting as Unilateral Cellulitis with Successful Treatment Using Pamidronate Disodium

    PubMed Central

    Bernardo, Sebastian G.; Burnett, Mark E.; Gordon, Marsha

    2012-01-01

    Hypertrophic pulmonary osteoarthropathy is a paraneoplastic syndrome seen in patients with lung cancer. This condition is characterized by the presence of digital clubbing, periosteal thickening, synovial thickening, and severe pain of the affected joints. Other syndromes exhibiting clubbing may or may not have underlying diseases causing their manifestation. An example is primary hypertrophic osteoarthropathy, or pachydermoperiostosis. While clubbing makes up part of the clinical picture in both hypertrophic pulmonary osteoarthropathy and hypertrophic osteoarthropathy, the latter has no underlying disease associations. Rather, primary hypertrophic osteoarthropathy is familial, idiopathic, and has a chronic course often beginning during puberty in males. Secondary hypertrophic osteoarthropathy is an acquired form of clubbing that is classically associated with lung disease. However, it has also been associated with diseases of the heart, liver, and intestines. In the setting of pulmonary malignancy, secondary hypertrophic osteoarthropathy is known as hypertrophic pulmonary osteoarthropathy. Hypertrophic pulmonary osteoarthropathy has a distinct constellation of clinical findings that includes intractable pain often refractory to treatments other than resolution of the underlying disease process. The authors herein report a case of hypertrophic pulmonary osteoarthropathy masquerading as recurrent lower extremity cellulitis with chronic hand and foot pain in the setting of pulmonary malignancy that responded dramatically to intravenous pamidronate disodium (a bisphosphonate). Given the rarity of hypertrophic osteoarthropathy associated with lung cancer and the difficulty with pain management in such circumstances, the authors present the following case in which pain was mitigated by treatment with bisphosphonate therapy. PMID:23050033

  8. Magnetized stratified rotating shear waves

    NASA Astrophysics Data System (ADS)

    Salhi, A.; Lehner, T.; Godeferd, F.; Cambon, C.

    2012-02-01

    solution at infinite vertical wavelength (k3=0): There is an oscillatory behavior for τ>1+|K2/k1|, where τ=St is a dimensionless time and K2 is the radial component of the wave vector at τ=0. The model is suitable to describe instabilities leading to turbulence by the bypass mechanism that can be relevant for the analysis of magnetized stratified Keplerian disks with a purely azimuthal field. For initial isotropic conditions, the time evolution of the spectral density of total energy (kinetic + magnetic + potential) is considered. At k3=0, the vertical motion is purely oscillatory, and the sum of the vertical (kinetic + magnetic) energy plus the potential energy does not evolve with time and remains equal to its initial value. The horizontal motion can induce a rapid transient growth provided K2/k1≫1. This rapid growth is due to the aperiodic velocity vortex mode that behaves like Kh/kh where kh(τ)=[k12+(K2-k1τ)2]1/2 and Kh=kh(0). After the leading phase (τ>K2/k1≫1), the horizontal magnetic energy and the horizontal kinetic energy exhibit a similar (oscillatory) behavior yielding a high level of total energy. The contribution to energies coming from the modes k1=0 and k3=0 is addressed by investigating the one-dimensional spectra for an initial Gaussian dense spectrum. For a magnetized Keplerian disk with a purely vertical field, it is found that an important contribution to magnetic and kinetic energies comes from the region near k1=0. The limit at k1=0 of the streamwise one-dimensional spectra of energies, or equivalently, the streamwise two-dimensional (2D) energy, is then computed. The comparison of the ratios of these 2D quantities with their three-dimensional counterparts provided by previous direct numerical simulations shows a quantitative agreement.

  9. Magnetized stratified rotating shear waves.

    PubMed

    Salhi, A; Lehner, T; Godeferd, F; Cambon, C

    2012-02-01

    stability of the solution at infinite vertical wavelength (k(3) = 0): There is an oscillatory behavior for τ > 1+|K(2)/k(1)|, where τ = St is a dimensionless time and K(2) is the radial component of the wave vector at τ = 0. The model is suitable to describe instabilities leading to turbulence by the bypass mechanism that can be relevant for the analysis of magnetized stratified Keplerian disks with a purely azimuthal field. For initial isotropic conditions, the time evolution of the spectral density of total energy (kinetic + magnetic + potential) is considered. At k(3) = 0, the vertical motion is purely oscillatory, and the sum of the vertical (kinetic + magnetic) energy plus the potential energy does not evolve with time and remains equal to its initial value. The horizontal motion can induce a rapid transient growth provided K(2)/k(1)>1. This rapid growth is due to the aperiodic velocity vortex mode that behaves like K(h)/k(h) where k(h)(τ)=[k(1)(2) + (K(2) - k(1)τ)(2)](1/2) and K(h) =k(h)(0). After the leading phase (τ > K(2)/k(1)>1), the horizontal magnetic energy and the horizontal kinetic energy exhibit a similar (oscillatory) behavior yielding a high level of total energy. The contribution to energies coming from the modes k(1) = 0 and k(3) = 0 is addressed by investigating the one-dimensional spectra for an initial Gaussian dense spectrum. For a magnetized Keplerian disk with a purely vertical field, it is found that an important contribution to magnetic and kinetic energies comes from the region near k(1) = 0. The limit at k(1) = 0 of the streamwise one-dimensional spectra of energies, or equivalently, the streamwise two-dimensional (2D) energy, is then computed. The comparison of the ratios of these 2D quantities with their three-dimensional counterparts provided by previous direct numerical simulations shows a quantitative agreement. PMID:22463311

  10. Regulation of Cardiac Hypertrophic Signaling by Prolyl Isomerase Pin1

    PubMed Central

    Toko, Haruhiro; Konstandin, Mathias H.; Doroudgar, Shirin; Ormachea, Lucia; Joyo, Eri; Joyo, Anya Y.; Din, Shabana; Gude, Natalie A.; Collins, Brett; Völkers, Mirko; Thuerauf, Donna J.; Glembotski, Christopher C.; Chen, Chun-Hau; Lu, Kun Ping; Müller, Oliver J.; Uchida, Takafumi; Sussman, Mark A.

    2013-01-01

    Rationale Cardiac hypertrophy results from the complex interplay of differentially regulated cascades based upon the phosphorylation status of involved signaling molecules. While numerous critical regulatory kinases and phosphatases have been identified in the myocardium, the intracellular mechanism for temporal regulation of signaling duration and intensity remains obscure. In the non-myocyte context, control of folding, activity, and stability of proteins is mediated by the prolyl isomerase Pin1, but the role of Pin1 in the heart is unknown. Objective To establish the role of Pin1 in the heart. Methods and Results Here we show that either genetic deletion or cardiac over-expression of Pin1 blunts hypertrophic responses induced by transaortic constriction and consequent cardiac failure in vivo. Mechanistically, we find that Pin1 directly binds to Akt, MEK and Raf-1 in cultured cardiomyocytes following hypertrophic stimulation. Furthermore, loss of Pin1 leads to diminished hypertrophic signaling of Akt and MEK, while over-expression of Pin1 increases Raf-1 phosphorylation on the auto-inhibitory site Ser259 leading to reduced MEK activation. Conclusions Collectively, these data support a role for Pin1 as a central modulator of the intensity and duration of two major hypertrophic signaling pathways, thereby providing a novel target for regulation and control of cardiac hypertrophy. PMID:23487407

  11. Hypertrophic Cardiomyopathy: Practical Steps for Preventing Sudden Death.

    ERIC Educational Resources Information Center

    Maron, Barry J.

    2002-01-01

    Hypertrophic cardiomyopathy (HCM) is a rare cause of death among athletes, with deaths occurring in young, apparently healthy people. Differentiating HCM from conditioning hypertrophy is challenging. Routine detection involves family history, physical examination, electrocardiography, and echocardiography. Keys to differential diagnosis include…

  12. Difficulty of diagnosing infected hypertrophic pseudarthrosis by radionuclide imaging

    SciTech Connect

    Hadjipavlou, A.; Lisbona, R.; Rosenthall, L.

    1983-02-01

    Hypertrophic pseudarthrosis was studied with /sup 99m/Tc MDP and /sup 67/Ga citrate in 11 patients. Two of the 11 pseudarthroses were complicated by infection. A high concentration of both radiopharmaceuticals was obtained at all 11 sites and their distribution patterns were identical. It was therefore impossible to distinguish the infected from the noninfected pseudarthroses by using /sup 67/Ga.

  13. Hypertrophic osteopathy associated with a renal adenoma in a cat.

    PubMed

    Johnson, Robert L; Lenz, Stephen D

    2011-01-01

    Hypertrophic osteopathy is a hyperostotic syndrome of the appendicular skeleton that is most commonly associated with intrathoracic neoplasia or inflammation. The condition is rarely associated with intra-abdominal lesions. The majority of cases have occurred in dogs and human beings, with fewer cases reported in cats, horses, and other species. A 15-year-old male neutered Domestic Shorthair cat presented for swollen limbs and difficulty in ambulation. Radiographs and gross postmortem revealed severe periosteal hyperostosis of the diaphysis and metaphysis of all 4 limbs, including the humerus, radius, ulna, carpi, metacarpi, femur, tibia, tarsi, metatarsi, and phalanges. The axial skeleton was spared. Hyperostotic lesions were characterized microscopically by lamellar bony trabeculae separated by adipocytes and scant hematopoietic tissue. In several areas, fibrovascular connective tissue, woven bone, and islands of cartilage were also present. A 2.5 cm × 2.5 cm perirenal neoplasm compressed the left kidney and adrenal gland. This mass consisted of well-differentiated tubules of cuboidal epithelial cells and was most consistent with a renal tubular adenoma, because mitotic figures were rare, and no distant metastases were found. Thoracic pathology was absent. Hyperostosis was consistent with hypertrophic osteopathy secondary to the renal adenoma. The pathogenesis of hypertrophic osteopathy is uncertain, but predominant theories point to increased peripheral circulation and angiogenesis as a key initiating event. Recent literature highlights the potential role of vascular endothelial growth factor and platelet-derived growth factor in the human condition. The mechanism by which this renal adenoma caused hypertrophic osteopathy is unknown.

  14. Inflammation and impaired adipogenesis in hypertrophic obesity in man.

    PubMed

    Gustafson, Birgit; Gogg, Silvia; Hedjazifar, Shahram; Jenndahl, Lachmi; Hammarstedt, Ann; Smith, Ulf

    2009-11-01

    Obesity is associated mainly with adipose cell enlargement in adult man (hypertrophic obesity), whereas the formation of new fat cells (hyperplastic obesity) predominates in the prepubertal age. Adipose cell size, independent of body mass index, is negatively correlated with whole body insulin sensitivity. Here, we review recent findings linking hypertrophic obesity with inflammation and a dysregulated adipose tissue, including local cellular insulin resistance with reduced IRS-1 and GLUT4 protein content. In addition, the number of preadipocytes in the abdominal subcutaneous adipose tissue capable of undergoing differentiation to adipose cells is reduced in hypertrophic obesity. This is likely to promote ectopic lipid accumulation, a well-known finding in these individuals and one that promotes insulin resistance and cardiometabolic risk. We also review recent results showing that TNFα, but not MCP-1, resistin, or IL-6, completely prevents normal adipogenesis in preadipocytes, activates Wnt signaling, and induces a macrophage-like phenotype in the preadipocytes. In fact, activated preadipocytes, rather than macrophages, may completely account for the increased release of chemokines and cytokines by the adipose tissue in obesity. Understanding the molecular mechanisms for the impaired preadipocyte differentiation in the subcutaneous adipose tissue in hypertrophic obesity is a priority since it may lead to new ways of treating obesity and its associated metabolic complications.

  15. Hypertrophic osteoarthropathy as a clinical manifestation of lung cancer.

    PubMed

    Davis, Melissa C; Sherry, Victoria

    2011-10-01

    Hypertrophic osteoarthropathy is a paraneoplastic syndrome most often found in non-small cell lung cancer. Diagnosis is confirmed by the presence of clubbing on physical examination and periostitis on bone scintigram, and the syndrome generally resolves with treatment of the underlying malignancy. This article presents a case study and describes symptom management options, including nonsteroidal anti-inflammatory agents, octreotide, and bisphosphonates.

  16. Hypertrophic cardiomyopathy in infants: clinical features and natural history

    SciTech Connect

    Maron, B.J.; Tajik, A.J.; Ruttenberg, H.D.; Graham, T.P.; Atwood, G.F.; Victorica, B.E.; Lie, J.T.; Roberts, W.C.

    1982-01-01

    The clinical and morphologic features of hypertrophic cardiomyopathy in 20 patients recognized as having cardiac disease in the first year of life are described. Fourteen of these 20 infants were initially suspected of having heart disease solely because a heart murmur was identified. However, the infants showed a variety of clinical findings, including signs of marked congestive heart failure (in the presence of nondilated ventricular cavities and normal or increased left ventricular contractility) and substantial cardiac enlargement on chest radiograph. Other findings were markedly different from those usually present in older children and adults with hypertrophic cardiomyopathy (e.g., right ventricular hypertrophy on the ECG and cyanosis). Consequently, in 14 infants, the initial clinical diagnosis was congenital cardiac malformation other than hypertrophic cardiomyopathy. The clinical course was variable in these patients, but the onset of marked congestive heart failure in the first year of life appeared to be an unfavorable prognostic sign; nine of the 11 infants with congestive heart failure died within the first year of life. In infants with hypertrophic cardiomyopathy, unlike older children and adults with this condition, sudden death was less common (two patients) than death due to progressive congestive heart failure.

  17. A case of hypertrophic osteoarthropathy in a Belgian blue cow

    PubMed Central

    Guyot, Hugues; Sandersen, Charlotte; Rollin, Frédéric

    2011-01-01

    A 12-year-old cow was presented with chronic respiratory disease and lameness. Chronic pleuritis, pneumonia, and bronchial carcinoma were found as well as periosteal proliferation on limb bones. Ancillary tests and necropsy confirmed a combined pathology of pulmonary inflammation and neoplasm, and hypertrophic pulmonary osteopathy. PMID:22654134

  18. Sediment Ammonia-Oxidizing Microorganisms in Two Plateau Freshwater Lakes at Different Trophic States.

    PubMed

    Yang, Yuyin; Zhang, Jingxu; Zhao, Qun; Zhou, Qiheng; Li, Ningning; Wang, Yilin; Xie, Shuguang; Liu, Yong

    2016-02-01

    Both ammonia-oxidizing archaea (AOA) and bacteria (AOB) can contribute to ammonia biotransformation in freshwater lake ecosystems. However, the factors shaping the distribution of sediment AOA and AOB in plateau freshwater lake remains unclear. The present study investigated sediment AOA and AOB communities in two freshwater lakes (hypertrophic Dianchi Lake and mesotrophic Erhai Lake) on the Yunnan Plateau (China). A remarkable difference in the abundance, diversity, and composition of sediment AOA and AOB communities was observed between Dianchi Lake and Erhai Lake. AOB usually outnumbered AOA in Dianchi Lake, but AOA showed the dominance in Erhai Lake. Organic matter (OM), total nitrogen (TN), and total phosphorus (TP) might be the key determinants of AOB abundance, while AOA abundance was likely influenced by the ration of OM to TN (C/N). AOA or AOB community structure was found to be relatively similar in the same lake. TN and TP might play important roles in shaping sediment AOA and AOB compositions in Dianchi Lake and Erhai Lake. Moreover, Nitrososphaera-like AOA were detected in Dianchi Lake. Nitrosospira- and Nitrosomonas-like AOB were dominant in Dianchi Lake and Erhai Lake, respectively. Sediment AOA and AOB communities in Dianchi Lake and Erhai Lake were generally regulated by trophic state. PMID:26111964

  19. Sediment Ammonia-Oxidizing Microorganisms in Two Plateau Freshwater Lakes at Different Trophic States.

    PubMed

    Yang, Yuyin; Zhang, Jingxu; Zhao, Qun; Zhou, Qiheng; Li, Ningning; Wang, Yilin; Xie, Shuguang; Liu, Yong

    2016-02-01

    Both ammonia-oxidizing archaea (AOA) and bacteria (AOB) can contribute to ammonia biotransformation in freshwater lake ecosystems. However, the factors shaping the distribution of sediment AOA and AOB in plateau freshwater lake remains unclear. The present study investigated sediment AOA and AOB communities in two freshwater lakes (hypertrophic Dianchi Lake and mesotrophic Erhai Lake) on the Yunnan Plateau (China). A remarkable difference in the abundance, diversity, and composition of sediment AOA and AOB communities was observed between Dianchi Lake and Erhai Lake. AOB usually outnumbered AOA in Dianchi Lake, but AOA showed the dominance in Erhai Lake. Organic matter (OM), total nitrogen (TN), and total phosphorus (TP) might be the key determinants of AOB abundance, while AOA abundance was likely influenced by the ration of OM to TN (C/N). AOA or AOB community structure was found to be relatively similar in the same lake. TN and TP might play important roles in shaping sediment AOA and AOB compositions in Dianchi Lake and Erhai Lake. Moreover, Nitrososphaera-like AOA were detected in Dianchi Lake. Nitrosospira- and Nitrosomonas-like AOB were dominant in Dianchi Lake and Erhai Lake, respectively. Sediment AOA and AOB communities in Dianchi Lake and Erhai Lake were generally regulated by trophic state.

  20. Analysis of hypertrophic and normal scar gene expression with cDNA microarrays.

    PubMed

    Tsou, R; Cole, J K; Nathens, A B; Isik, F F; Heimbach, D M; Engrav, L H; Gibran, N S

    2000-01-01

    Hypertrophic scar is one form of abnormal wound healing. Previous studies have suggested that hypertrophic scar formation results from altered gene expression of extracellular matrix molecules. A broadscale evaluation of gene expression in hypertrophic scars has not been reported. To better understand abnormalities in hypertrophic scar gene expression, we compared messenger RNA expression in hypertrophic scars, normal scars, and uninjured skin with the use of complementary (c)DNA microarrays. Total RNA was extracted from freshly excised human hypertrophic scars, normal scars, or uninjured skin and reverse transcribed into cDNA with the incorporation of [33P] deoxycytidine triphosphate. The resulting radioactive cDNA probes were hybridized onto cDNA microarrays of 4000 genes. Hybridization signals were normalized and analyzed. In the comparison of tissue samples, mean intensities were calculated for each gene within each group (hypertrophic scars, normal scars, and uninjured skin). Ratios of the mean intensities of hypertrophic scars to normal scars, hypertrophic scars to uninjured skin, and normal scars to uninjured skin were generated. A ratio that was greater than 1 indicated upregulation of any particular gene and a ratio that was less than 1 indicated downregulation of any particular gene. Our data indicated that 142 genes were overexpressed and 50 genes were underexpressed in normal scars compared with uninjured skin, 107 genes were overexpressed and 71 were underexpressed in hypertrophic scars compared with uninjured skin, and 44 genes were overexpressed and 124 were underexpressed in hypertrophic scars compared with normal scars. Our analysis of collagen, growth factor, and metalloproteinase gene expression confirmed that our molecular data were consistent with published biochemical and clinical observations of normal scars and hypertrophic scars. cDNA microarray analysis provides a powerful tool for the investigation of differential gene expression in

  1. BEHAVIOR OF ARSENIC AND OTHER REDOX-SENSITIVE ELEMENTS IN CROWLEY LAKE, CA: A RESERVOIR IN THE LOS ANGELES AQUEDUCT SYSTEM. (R826202)

    EPA Science Inventory

    Elevated arsenic concentrations in Crowley Lake derive from upstream geothermal inputs. We examined the water column of Crowley Lake under stratified and unstratified conditions, seeking evidence for algal uptake and transformation of arsenic and its deposition to and release fro...

  2. THE WESTERN LAKE SUPERIOR COMPARATIVE WATERSHED FRAMEWORK: A FIELD TEST OF GEOGRAPHICALLY-DEPENDENT VS. THRESHOLD-BASED GEOGRAPHICALLY-INDEPENDENT CLASSIFICATION

    EPA Science Inventory

    Stratified random selection of watersheds allowed us to compare geographically-independent classification schemes based on watershed storage (wetland + lake area/watershed area) and forest fragmentation with a geographically-based classification scheme within the Northern Lakes a...

  3. Hypertrophic Cardiomyopathy Registry (HCMR): The rationale and design of an international, observational study of hypertrophic cardiomyopathy

    PubMed Central

    Kramer, Christopher M.; Appelbaum, Evan; Desai, Milind Y.; Desvigne-Nickens, Patrice; DiMarco, John P.; Friedrich, Matthias G.; Geller, Nancy; Heckler, Sarahfaye; Ho, Carolyn Y.; Jerosch-Herold, Michael; Ivey, Elizabeth A.; Keleti, Julianna; Kim, Dong-Yun; Kolm, Paul; Kwong, Raymond Y.; Maron, Martin S.; Schulz-Menger, Jeanette; Piechnik, Stefan; Watkins, Hugh; Weintraub, William S.; Wu, Pan; Neubauer, Stefan

    2015-01-01

    Hypertrophic cardiomyopathy (HCM) is the most common monogenic heart disease with a frequency as high as 1 in 200. In many cases, HCM is caused by mutations in genes encoding the different components of the sarcomere apparatus. HCM is characterized by unexplained left ventricular hypertrophy (LVH), myofibrillar disarray, and myocardial fibrosis. The phenotypic expression is quite variable. While the majority of patients with HCM are asymptomatic, serious consequences are experienced in a subset of affected individuals who present initially with sudden cardiac death (SCD) or progress to refractory heart failure (HF). The HCMR study is a National Heart Lung and Blood Institute (NHLBI)-sponsored 2750 patient, 41 site, international registry and natural history study designed to address limitations in extant evidence to improve prognostication in HCM (NCT01915615). In addition to collection of standard demographic, clinical, and echocardiographic variables, patients will undergo state-of-the-art cardiac magnetic resonance (CMR) for assessment of left ventricular (LV) mass and volumes as well as replacement scarring and interstitial fibrosis. In addition, genetic and biomarker analysis will be performed. HCMR has the potential to change the paradigm of risk stratification in HCM, using novel markers to identify those at higher risk. PMID:26299218

  4. Thermals in stratified regions of the ISM

    NASA Astrophysics Data System (ADS)

    Rodríguez-González, A.; Raga, A. C.

    2013-10-01

    We present a model of a ``thermal'' (i.e., a hot bubble) rising within an exponentially stratified region of the ISM. This model includes terms representing the ram pressure braking and the entrainment of environmental gas into the thermal. We then calibrate the free parameters associated with these two terms through a comparison with 3D numerical simulations of a rising bubble. Finally, we apply our ``thermal'' model to the case of a hot bubble produced by a SN within the stratified ISM of the Galactic disk.

  5. Stratified charge rotary engine for general aviation

    NASA Technical Reports Server (NTRS)

    Mount, R. E.; Parente, A. M.; Hady, W. F.

    1986-01-01

    A development history, a current development status assessment, and a design feature and performance capabilities account are given for stratified-charge rotary engines applicable to aircraft propulsion. Such engines are capable of operating on Jet-A fuel with substantial cost savings, improved altitude capability, and lower fuel consumption by comparison with gas turbine powerplants. Attention is given to the current development program of a 400-hp engine scheduled for initial operations in early 1990. Stratified charge rotary engines are also applicable to ground power units, airborne APUs, shipboard generators, and vehicular engines.

  6. Anomalous response of stratified fluid to forcing

    SciTech Connect

    Ingel, L. Kh.

    2006-01-15

    The time-independent disturbances induced by nonuniformly distributed surface shear stress in a binary fluid (salt water) are analyzed in the linear approximation. It is shown that correct treatment of two scalar fields (stratified background temperature and salinity distributions) may lead to counterintuitive qualitative predictions even if the thermal and salt diffusivities are equal. In particular, when stable salinity stratification is imposed on stable temperature stratification, both the amplitude and depth of the disturbance may substantially increase rather than decrease (contrary to intuitive expectations). A previously unknown mechanism of convective instability is revealed for a stable density-stratified binary fluid.

  7. Thermal laminarization of a stratified pipe flow

    SciTech Connect

    Oras, J.J.; Kasza, K.E.

    1984-01-01

    The present work constitutes a new program that grew out of a scoping assessment by ANL to determine the propensity for pipe stratification to occur in the reactor outlet nozzles and hot-leg piping of a generic LMFBR during events producing reverse pipe flow. This paper focuses on the role that thermal buoyancy plays relative to being able to laminarize a turbulent stratified shear zone in a horizontal pipe. The preceeding can influence the behavior of a pipe stratified-backflow-recirculation zone (cold plenum water down into the hot pipe flow) which developes as the result of a temperature difference between the pipe flow and the plenum.

  8. ESTIMATING TROPHIC STATE PROPORTIONS OF A REGIONAL LAKE POPULATION: ARE LARGER SAMPLES ALWAYS BETTER?

    EPA Science Inventory

    During the summers of 1991-1994, the Environmental Monitoring and Assessment Program (EMAP) sampled 344 lakes throughout the northeastern United States using a proportional stratified sampling design based on lake size. Approximately one-quarter of the 344 lakes were sampled eac...

  9. Effects of Noscarna™ on hypertrophic scarring in the rabbit ear model: histopathological aspects.

    PubMed

    Lee, Dong Won; Ku, Sae Kwang; Cho, Hyuk Jun; Kim, Jeong Hwan; Hiep, Tran Tuan; Han, Sang Duk; Kim, Bo Gyun; Kang, Min Kyung; Do, Eui Seon; Jun, Joon Ho; Jang, Sun Woo; Son, Mi-Won; Sohn, Young Taek; Choi, Han-Gon; Yong, Chul Soon; Kim, Jong Oh

    2012-11-01

    In this study, we evaluated the effects of silicone-based gel on the healing of hypertrophic scars in the rabbit ear model. After 4-week application of silicone-based gel containing allantoin, dexpanthenol and heparin (Noscarna™) to scars in a rabbit ear model of hypertrophic scarring, significant improvements in hypertrophic scar healing and a great loss of skin pigment were observed compared to the non-treated control, base or silicone control-treated scars. Furthermore, histological analysis of Noscarna™-treated scars revealed a significant reduction in scar elevation index (SEI), anterior skin and epithelial thicknesses, inflammatory cells, vessels, collagen disorganization and fibroblasts compared to all control hypertrophic scars. Furthermore, Noscarna™ showed more favorable effects on hypertrophic scars than a commercial product, Contractubex®. Therefore, these results clearly demonstrated that the newly developed silicone-based gel, Noscarna™, could be a promising formulation as an effective therapeutic agent for hypertrophic scars. PMID:23212642

  10. Idiopathic hypertrophic cranial pachymenigitis - A long follow-up needed.

    PubMed

    Hashmi, M A; Gautam, G; Sengupta, P; Singh, H; Haque, N

    2011-07-01

    Idiopathic hypertrophic cranial pachymenigitis is a rare clinical condition caused by localized or diffuse inflammatory thickening of dura matter. Described here is a person having diffuse thickening of dura matter of base of skull and he was on follow-up treatment for 5 years with us. Diagnosis was done by excluding other conditions and with biopsy. The patient responded to steroid and the MRI picture, which is given serially, shows improvement. PMID:22347338

  11. [The sonographic diagnosis of hypertrophic stenosis of the pylorus].

    PubMed

    Rodríguez, R I; Briceño de Rodríguez, J A; Urrutia, M

    1993-09-01

    The clinical records of 18 children were studied, between 15 and 60 days old. They were hospitalized due to vomiting and diagnosis of suspected pyloric hypertrophic stenosis (PHS). The sonography confirmed the diagnosis in 8 children, by the thickening of the muscular layer and enlargement of the pyloric canal. The surgery (pyloromyotomy) ratified the diagnosis in all 8 children. They all were in good health after being operated. PMID:8146343

  12. [The sonographic diagnosis of hypertrophic stenosis of the pylorus].

    PubMed

    Rodríguez, R I; Briceño de Rodríguez, J A; Urrutia, M

    1993-05-01

    The clinical records of 18 children were studied, between 15 and 60 days old. They were hospitalized due to vomiting and diagnosis of suspected pyloric hypertrophic stenosis (PHS). The sonography confirmed the diagnosis in 8 children, by the thickening of the muscular layer and enlargement of the pyloric canal. The surgery (pyloromyotomy) ratified the diagnosis in all 8 children. They all were in good health after being operated. PMID:8327749

  13. Mutations in 15-hydroxyprostaglandin dehydrogenase cause primary hypertrophic osteoarthropathy.

    PubMed

    Uppal, Sandeep; Diggle, Christine P; Carr, Ian M; Fishwick, Colin W G; Ahmed, Mushtaq; Ibrahim, Gamal H; Helliwell, Philip S; Latos-Bieleńska, Anna; Phillips, Simon E V; Markham, Alexander F; Bennett, Christopher P; Bonthron, David T

    2008-06-01

    Digital clubbing, recognized by Hippocrates in the fifth century BC, is the outward hallmark of pulmonary hypertrophic osteoarthropathy, a clinical constellation that develops secondary to various acquired diseases, especially intrathoracic neoplasm. The pathogenesis of clubbing and hypertrophic osteoarthropathy has hitherto been poorly understood, but a clinically indistinguishable primary (idiopathic) form of hypertrophic osteoarthropathy (PHO) is recognized. This familial disorder can cause diagnostic confusion, as well as significant disability. By autozygosity methods, we mapped PHO to chromosome 4q33-q34 and identified mutations in HPGD, encoding 15-hydroxyprostaglandin dehydrogenase, the main enzyme of prostaglandin degradation. Homozygous individuals develop PHO secondary to chronically elevated prostaglandin E(2) levels. Heterozygous relatives also show milder biochemical and clinical manifestations. These findings not only suggest therapies for PHO, but also imply that clubbing secondary to other pathologies may be prostaglandin mediated. Testing for HPGD mutations and biochemical testing for HPGD deficiency in patients with unexplained clubbing might help to obviate extensive searches for occult pathology. PMID:18500342

  14. Familial hypertrophic cardiomyopathy: vectorcardiographic findings in echocardiographically unaffected relative.

    PubMed Central

    Loperfido, F; Fiorilli, R; Digaetano, A; Di Gennaro, M; Santarelli, P; Bellocci, F; Coppola, E; Zecchi, P

    1982-01-01

    The electrocardiographic and vectorcardiographic (Frank system) features of the first degree relatives of subjects with documented familial hypertrophic cardiomyopathy were analysed. A total of nine affected members and 29 relatives were examined in four families. THe subjects were considered to be affected when the septal to free posterior wall thickness ratio exceeded 1.3 at M-mode echocardiography. Four relatives had asymmetric septal hypertrophy. Among 25 relatives without evidence of asymmetric septal hypertrophy, two over 20 years and 10 under 20 years of age showed increased voltage of QRS anterior forces (Qz amplitude greater than 0.80 mV) on the orthogonal electrocardiogram. The vectorcardiographic data of the relatives under 20 years of age without evidence of asymmetric septal hypertrophy (18 subjects) were compared with those of 38 normal control subjects of comparable age range. The young relatives without disproportionate septal hypertrophy had significantly greater Qz amplitude and Q/Rz ratio than the normal control subjects. In contrast, the echocardiographic data were not significantly different. We suggest that the electrocardiographic finding of abnormal anterior forces in one or more first degree relatives of subjects with documented hypertrophic cardiomyopathy may constitute a valuable aid in ascertaining the genetic transmission of the disease and in recognising affected members without echocardiographic evidence of hypertrophic cardiomyopathy. Images PMID:7200794

  15. Oscillations in a Linearly Stratified Salt Solution

    ERIC Educational Resources Information Center

    Heavers, Richard M.

    2007-01-01

    Our physics students like to watch a ball bouncing underwater. They do this by dropping a weighted plastic ball into a 1000-ml cylinder filled with a linearly stratified salt-water solution at room temperature. The ball oscillates and comes to rest at about mid-depth. Its motion is analogous to the damped vertical oscillations of a mass hanging…

  16. Risk-Stratified Imputation in Survival Analysis

    PubMed Central

    Kennedy, Richard E.; Adragni, Kofi P.; Tiwari, Hemant K.; Voeks, Jenifer H.; Brott, Thomas G.; Howard, George

    2013-01-01

    Background Censoring that is dependent on covariates associated with survival can arise in randomized trials due to changes in recruitment and eligibility criteria to minimize withdrawals, potentially leading to biased treatment effect estimates. Imputation approaches have been proposed to address censoring in survival analysis; and while these approaches may provide unbiased estimates of treatment effects, imputation of a large number of outcomes may over- or underestimate the associated variance based on the imputation pool selected. Purpose We propose an improved method, risk-stratified imputation, as an alternative to address withdrawal related to the risk of events in the context of time-to-event analyses. Methods Our algorithm performs imputation from a pool of replacement subjects with similar values of both treatment and covariate(s) of interest, that is, from a risk-stratified sample. This stratification prior to imputation addresses the requirement of time-to-event analysis that censored observations are representative of all other observations in the risk group with similar exposure variables. We compared our risk-stratified imputation to case deletion and bootstrap imputation in a simulated dataset in which the covariate of interest (study withdrawal) was related to treatment. A motivating example from a recent clinical trial is also presented to demonstrate the utility of our method. Results In our simulations, risk-stratified imputation gives estimates of treatment effect comparable to bootstrap and auxiliary variable imputation while avoiding inaccuracies of the latter two in estimating the associated variance. Similar results were obtained in analysis of clinical trial data. Limitations Risk-stratified imputation has little advantage over other imputation methods when covariates of interest are not related to treatment, although its performance is superior when covariates are related to treatment. Risk-stratified imputation is intended for

  17. Basic limnology of fifty-one lakes in Costa Rica.

    PubMed

    Haberyan, Kurt A; Horn, Sally P; Umaña, Gerardo

    2003-03-01

    We visited 51 lakes in Costa Rica as part of a broad-based survey to document their physical and chemical characteristics and how these relate to the mode of formation and geographical distribution of the lakes. The four oxbow lakes were low in elevation and tended to be turbid, high in conductivity and CO2, but low in dissolved O2; one of these, L. Gandoca, had a hypolimnion essentially composed of sea water. These were similar to the four wetland lakes, but the latter instead had low conductivities and pH, and turbidity was often due to tannins rather than suspended sediments. The thirteen artificial lakes formed a very heterogenous group, whose features varied depending on local factors. The thirteen lakes dammed by landslides, lava flows, or lahars occurred in areas with steep slopes, and were more likely to be stratified than most other types of lakes. The eight lakes that occupy volcanic craters tended to be deep, stratified, clear, and cool; two of these, L. Hule and L. Río Cuarto, appeared to be oligomictic (tending toward meromictic). The nine glacial lakes, all located above 3440 m elevation near Cerro Chirripó, were clear, cold, dilute, and are probably polymictic. Cluster analysis resulted in three significant groups of lakes. Cluster 1 included four calcium-rich lakes (average 48 mg l-1), Cluster 2 included fourteen lakes with more Si than Ca+2 and higher Cl- than the other clusters, and Cluster 3 included the remaining thirty-three lakes that were generally less concentrated. Each cluster included lakes of various origins located in different geographical regions; these data indicate that, apart from the high-altitude glacial lakes and lakes in the Miravalles area, similarity in lake chemistry is independent of lake distribution. PMID:15162686

  18. Flow and transport within a coastal aquifer adjacent to a stratified water body

    NASA Astrophysics Data System (ADS)

    Oz, Imri; Yechieli, Yoseph; Eyal, Shalev; Gavrieli, Ittai; Gvirtzman, Haim

    2016-04-01

    The existence of a freshwater-saltwater interface and the circulation flow of saltwater beneath the interface is a well-known phenomenon found at coastal aquifers. This flow is a natural phenomenon that occurs due to density differences between fresh groundwater and the saltwater body. The goals of this research are to use analytical, numerical, and physical models in order to examine the configuration of the freshwater-saltwater interface and the density-driven flow patterns within a coastal aquifer adjacent to long-term stratified saltwater bodies (e.g. meromictic lake). Such hydrological systems are unique, as they consist of three different water types: the regional fresh groundwater, and low and high salinity brines forming the upper and lower water layers of the stratified water body, respectively. This research also aims to examine the influence of such stratification on hydrogeological processes within the coastal aquifer. The coastal aquifer adjacent to the Dead Sea, under its possible future meromictic conditions, serves as an ideal example to examine these processes. The results show that adjacent to a stratified saltwater body three interfaces between three different water bodies are formed, and that a complex flow system, controlled by the density differences, is created, where three circulation cells are developed. These results are significantly different from the classic circulation cell that is found adjacent to non-stratified water bodies (lakes or oceans). In order to obtain a more generalized insight into the groundwater behavior adjacent to a stratified water body, we used the numerical model to perform sensitivity analysis. The hydrological system was found be sensitive to three dimensionless parameters: dimensionless density (i.e. the relative density of the three water bodies'); dimensionless thickness (i.e. the ratio between the relative thickness of the upper layer and the whole thickness of the lake); and dimensionless flux. The results

  19. Wakes of Maneuvering Bodies in Stratified Fluids

    NASA Astrophysics Data System (ADS)

    Voropayev, S. I.; Fernando, H. J.

    2007-05-01

    We present the results of experimental/theoretical studies on large momentum eddies generated in late wakes of unsteady moving self-propelled bodies in stratified fluids. The experiments were conducted with scaled submarine model at high Reynolds numbers (50,000), corresponding to the fully turbulent flow regime. Dye visualization and PIV were used for flow diagnostics. When a self-propelled body makes a maneuver, e.g. accelerates, it imparts net momentum on the surrounding fluid. We show that in a stratified fluid this leads to impulsive momentum wakes with large, long-lived coherent vortices in the late flows, which may be used as a signature for identification of submarine wakes in oceanic thermocline. First, we consider dynamics and properties of such wakes in a linearly stratified fluid and present a model that permits to predict the main flow characteristics. Second, we consider wakes in a two layer stratified fluid (analog of the upper ocean) and show that such wakes may penetrate to the water surface; we present a model for this phenomenon and propose criteria for the penetration of wake signatures to the water surface in terms of main governing parameters (signature contrast versus confinement number). Finally, we consider the evolution of such momentum wake eddies in the field of decaying background turbulence, which mimics the oceanic thermocline, and show that for the flow configuration studied the contrast number remains sufficiently large and detectable wake imprints survive for a long period of time. Some pertinent estimates for submarines cruising in the upper ocean are also given. For more details see [1-3]. This study was supported by grant from the Office of Naval Research. 1. Voropayev S.I., Fernando H.J.S., Smirnov S.A. & Morrison R.J. 2006. On surface signatures generated by submersed momentum sources. Phys. Fluids, under revision. 2. Voropayev S.I., Fernando H.J.S. & Morrison R.J. 2006. Dipolar eddies in a stratified turbulent flow. J. Fluid

  20. Competing risks regression for stratified data.

    PubMed

    Zhou, Bingqing; Latouche, Aurelien; Rocha, Vanderson; Fine, Jason

    2011-06-01

    For competing risks data, the Fine-Gray proportional hazards model for subdistribution has gained popularity for its convenience in directly assessing the effect of covariates on the cumulative incidence function. However, in many important applications, proportional hazards may not be satisfied, including multicenter clinical trials, where the baseline subdistribution hazards may not be common due to varying patient populations. In this article, we consider a stratified competing risks regression, to allow the baseline hazard to vary across levels of the stratification covariate. According to the relative size of the number of strata and strata sizes, two stratification regimes are considered. Using partial likelihood and weighting techniques, we obtain consistent estimators of regression parameters. The corresponding asymptotic properties and resulting inferences are provided for the two regimes separately. Data from a breast cancer clinical trial and from a bone marrow transplantation registry illustrate the potential utility of the stratified Fine-Gray model.

  1. Nitrogen transformations in stratified aquatic microbial ecosystems.

    PubMed

    Revsbech, Niels Peter; Risgaard-Petersen, Nils; Schramm, Andreas; Nielsen, Lars Peter

    2006-11-01

    New analytical methods such as advanced molecular techniques and microsensors have resulted in new insights about how nitrogen transformations in stratified microbial systems such as sediments and biofilms are regulated at a microm-mm scale. A large and ever-expanding knowledge base about nitrogen fixation, nitrification, denitrification, and dissimilatory reduction of nitrate to ammonium, and about the microorganisms performing the processes, has been produced by use of these techniques. During the last decade the discovery of anammmox bacteria and migrating, nitrate accumulating bacteria performing dissimilatory reduction of nitrate to ammonium have given new dimensions to the understanding of nitrogen cycling in nature, and the occurrence of these organisms and processes in stratified microbial communities will be described in detail.

  2. Stably Stratified Flow in a Shallow Valley

    NASA Astrophysics Data System (ADS)

    Mahrt, L.

    2016-07-01

    Stratified nocturnal flow above and within a small valley of approximately 12-m depth and a few hundred metres width is examined as a case study, based on a network of 20 sonic anemometers and a central 20-m tower with eight levels of sonic anemometers. Several regimes of stratified flow over gentle topography are conceptually defined for organizing the data analysis and comparing with the existing literature. In our case study, a marginal cold pool forms within the shallow valley in the early evening but yields to larger ambient wind speeds after a few hours, corresponding to stratified terrain-following flow where the flow outside the valley descends to the valley floor. The terrain-following flow lasts about 10 h and then undergoes transition to an intermittent marginal cold pool towards the end of the night when the larger-scale flow collapses. During this 10-h period, the stratified terrain-following flow is characterized by a three-layer structure, consisting of a thin surface boundary layer of a few metres depth on the valley floor, a deeper boundary layer corresponding to the larger-scale flow, and an intermediate transition layer with significant wind-directional shear and possible advection of lee turbulence that is generated even for the gentle topography of our study. The flow in the valley is often modulated by oscillations with a typical period of 10 min. Cold events with smaller turbulent intensity and duration of tens of minutes move through the observational domain throughout the terrain-following period. One of these events is examined in detail.

  3. Evolution of a forced stratified mixing layer

    NASA Astrophysics Data System (ADS)

    Rotter, J.; Fernando, H. J. S.; Kit, E.

    2007-06-01

    Laboratory measurements were carried out in a spatially developing stably stratified shear layer generated downstream of a splitter plate. The instabilities were controlled using a flapper spanning the entire shear layer, with the flapper forced at the fastest growing frequency of the primary [Kelvin-Helmholtz (KH)] instability. The measurements were taken as the KH instabilities roll up, break down, and degenerate into stratified turbulence. Both stratified and homogeneous shear layers were considered, the latter acting as the "baseline" case. The measurements included the streamwise and vertical velocities (made using X-wire hot film probes), which allowed calculation of the mean and rms velocities, turbulent kinetic energy (TKE) dissipation, and TKE production. The density and its gradients were measured using miniature conductivity probes. The measurements and flow visualization elicited interesting features of KH evolution, namely that KH billows may be turbulent from the onset, the TKE dissipation is largest at early stages of evolution, the production of TKE is a maximum at the breakdown of billows, the decay of turbulence to fossilized motions and concomitant formation of fine (layered) structure occur rapidly after the breakdown of billows, and episodic rebirth of (zombie) turbulence develops before a final permanently fossilized state is achieved.

  4. Structural differences in epiphyseal and physeal hypertrophic chondrocytes

    PubMed Central

    Shapiro, Frederic; Flynn, Evelyn

    2015-01-01

    We have observed that epiphyseal and physeal hypertrophic chondrocytes in BALB/c mice show considerable differences of light microscopic and ultrastructural appearance, even when the cells are at the same stage of differentiation. In addition, cell structure maintenance improved with tissue preparation controlled for osmolarity and for membrane stabilization using 0.5% ruthenium hexammine trichloride (RHT) for both light microscopy (LM) and electron microscopy (EM) or 0.5% lanthanum nitrate for LM. Physeal hypertrophic chondrocytes showed a gradual increase in size closer to the metaphysis and a change in shape as cells elongated along the long axis. The nucleus remained central, with uniformly dispersed chromatin, and the rough endoplasmic reticulum (RER) was randomly dispersed throughout cytoplasm with little to no presence against the cell membrane. Even the lowermost cells showed thin elongated or dilated cisternae of RER and intact cell membranes. Epiphyseal chondrocytes remained circular to oval with no elongation. Nucleus and RER were positioned as a complete transcellular central nucleocytoplasmic column or as an incomplete bud with RER of the column/bud always continuous with RER peripherally against the intact cell membrane. RER was densely packed with parallel cisternae with adjacent cytoplasm empty of organelles but often filled with circular deposits of moderately electron-dense material consistent with fat. Optimal technique for LM involved fixation using glutaraldehyde (GA) 1.3%, paraformaldehyde (PFA) 1% and RHT 0.5% (mOsm 606) embedded in JB-4 plastic and stained with 0.5% toluidine blue. Optimal technique for EM used fixation with GA 1.3%, PFA 1%, RHT 0.5% and cacodylate buffer 0.03 M (mOsm 511) and post-fixation including 1% osmium tetroxide. These observations lead to the possibility that the same basic cell, the hypertrophic chondrocyte, has differing functional mechanisms at different regions of the developing bone. PMID:25987982

  5. [A clinical study of hypertrophic obstructive cardiomyopathy in the elderly].

    PubMed

    Chida, K; Ohkawa, S; Maeda, S; Kuboki, K; Imai, T; Sakai, M; Watanabe, C; Matsushita, S; Ueda, K; Kuramoto, K

    1990-09-01

    Seven elderly patients with hypertrophic obstructive cardiomyopathy (HOCM), who had the three following characteristics on echocardiograms 1) extremely thickened septum, 2) systolic anterior motion of the mitral valve, 3) mid systolic semi-closure of the aortic valve, were clinically evaluated. Ages ranged from 73 to 86 years old (average 78.9% yr.) and all were women. None had not a family history of hypertrophic cardiomyopathy but they had mild hypertension. Six patients showed a significant high voltage on the ST-segment and T-wave abnormalities ("strain" pattern). The left ventricular posterior wall as well as the septum was thickened in 5 and the remaining 2 showed asymmetrical septal hypertrophy (ASH) on echocardiograms. The left ventricular cavity was narrowed due to left ventricular hypertrophy and the shape of the left ventricular cavity was ovoid in all patients. The aorto-septal angles in these 7 patients were 80 degrees to 120 degrees. In addition, proximal septal bulge in all and anterior displacement of the mitral posterior leaflet due to the mitral ring calcification (MRC) in some patients contributed to the narrowing of the left ventricular outflow tract, and the mitral valve was pulled up toward the septum because of the good left ventricular systolic function (ejection fraction: 70 to 94% by echocardiography) and blood was ejected at a high velocity through a narrowed outflow tract (Venturi effect). Pressure gradients in the left ventricular outflow tract was 38 to 146 mmHg in 5 examined by cardiac catheterization. Biopsy specimens were obtained from 2 patients, showing hypertrophic myocytes (diameter: 20 to 30 micron) in 2 and mild disarray in 1.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. A Novel Triple Medicine Combination Injection for the Resolution of Keloids and Hypertrophic Scars

    PubMed Central

    Gold, Michael H.

    2014-01-01

    Keloids and hypertrophic scars remain one of the more difficult treatment concerns for clinicians. A variety of therapies have been used in the past with moderate success. On occasion, combination therapy has been used to treat these lesion, in an attempt to lessen the symptoms of pain and pruritus that often accompanies keloids and hypertrophic scars, as well as treating the actual lesions themselves. A novel triple combination injection process is introduced here in an attempt to further reduce the signs and symptoms of these lesions. The combination includes 5-fluoruracil, triamcinolone acetonide, and hyaluronidase. All three work in concert to treat keloids and hypertrophic scars, and this is the first work at looking at these medicines given together, at the same time, in a series of recalcitrant keloids and hypertrophic scars. The positive results warrant further investigation and hope for those with keloids and hypertrophic scars. PMID:25489380

  7. Ehlers-Danlos Syndrome associated with cardiomyopathy hypertrophic obstructive.

    PubMed

    Pinto, Raimundo José Almeida de Oliveira; Santos, Adaílton Araújo dos; Azevedo, Mablo de Castro; Meira, Saulo Sacramento

    2015-01-01

    Ehlers-Danlos syndrome is a rare clinical condition caused by a genetic change that results in the formation of structurally or functionally altered collagen. The clinical manifestations are varied, being the most obvious skin hypermotility and increased joint flexibility, although other systems - such as cardiovascular, respiratory and neurological - may also be affected. This paper presents the report of a patient who sought medical attention with complaints of atypical chest pain. Clinical evaluation enabled hypothetical diagnosis of hypertrophic obstructive cardiomyopathy and Ehlers-Danlos syndrome. Initial electrocardiogram, echocardiogram and 24 hours holter allowed the confirmation of the first hypothesis. A skin biopsy performed later associated clinical data and confirmed the second hypothesis.

  8. Recurrent hypertrophic peroneal tubercle associated with peroneus brevis tendon tear.

    PubMed

    Ochoa, Leah M; Banerjee, Rahul

    2007-01-01

    Stenosing peroneal tenosynovitis resulting from hypertrophy of the peroneal tubercle has been well described. Successful surgical treatment addresses the hypertrophied peroneal tubercle as well as any intrinsic tendon pathology. We report a case of recurrent foot pain caused by stenosing peroneal tenosynovitis in a 16-year-old woman. Four months after excision of a hypertrophic peroneal tubercle, the patient developed a recurrence of symptoms. Imaging studies, repeat operative exploration, and pathologic specimen demonstrated a recurrence of the peroneal tubercle hypertrophy associated with a longitudinal tear of the peroneus brevis tendon. Re-resection of the hypertrophied tubercle and peroneal tendon repair resulted in a resolution of symptoms. PMID:17761327

  9. Spiral hypertrophic cardiomyopathy as detected by cardiac magnetic resonance.

    PubMed

    Amin, Nessim; Williams, Ronald B; Yarmozik, June A; Biederman, Robert W W

    2014-03-01

    Hypertrophic cardiomyopathy (HCM) is a genetically determined heart muscle disease; characterized by left ventricular hypertrophy (LVH). Spiral HCM is described as having a counterclockwise rotation pattern of hypertrophy along with variable degrees of fibrosis. A 34-year-old female presented with symptoms suggestive of heart failure. Echocardiography showed concentric LVH with normal contractility. Cardiac MRI showed asymmetric septal hypertrophy with mid-cavity obliteration and a spiral pattern of variably increasing wall thickness. Late gadolinium enhancement (LGE) demonstrated several areas of abnormal postgadolinium uptake. We report a case of spiral HCM. We should consider cardiovascular magnetic resonance (CMR) as the reference standard for diagnosing HCM. PMID:24749165

  10. Hypertrophic cardiomyopathy in a mixed breed cat family.

    PubMed

    Nakagawa, Kiyoshi; Takemura, Naoyuki; Machida, Noboru; Kawamura, Masamichi; Amasaki, Hajime; Hirose, Hisashi

    2002-07-01

    A spayed female mixed cat (case 1) and its female offspring, the result of a pairing between case 1 and its male sibling, were diagnosed with hypertrophic cardiomyopathy (HCM). A pedigree survey revealed that the prevalence of HCM was at least 12.5% in the family, which was considered to be significantly higher than that in a hospital-based population (approximately 1.6%). Thus, this finding seems to support the suspected occurrence of familial HCM in this group of related cats.

  11. Whole-lake burdens and spatial distribution of mercury in surficial sediments in Wisconsin seepage lakes

    USGS Publications Warehouse

    Rada, R.G.; Powell, D.E.; Wiener, J.G.

    1993-01-01

    We quantified total mercury in surficial sediments (uppermost 5 cm) of six small seepage lakes. Fifty cores were taken from each lake, based on a random sampling design stratified by water depth. Volumetric concentrations (mass per volume of wet sediment) more accurately portrayed the depth distribution of mercury in the lakes than did dry-weight concentrations, which underrepresented the significance of the shallow-water sediments as a reservoir of potentially available mercury. Estimates of whole-lake burdens (masses) of mercury in the surficial sediment, which represents the maximum amount of sedimentary mercury available for methylation, ranged from 45 to 149 g. We hypothesize that the observed variation in areal burdens of mercury was partly due to variation among lakes in the pH-related efflux of gaseous mercury (Hg super(0)) from the lakes to the atmosphere.

  12. Stably stratified canopy flow in complex terrain

    NASA Astrophysics Data System (ADS)

    Xu, X.; Yi, C.; Kutter, E.

    2015-07-01

    Stably stratified canopy flow in complex terrain has been considered a difficult condition for measuring net ecosystem-atmosphere exchanges of carbon, water vapor, and energy. A long-standing advection error in eddy-flux measurements is caused by stably stratified canopy flow. Such a condition with strong thermal gradient and less turbulent air is also difficult for modeling. To understand the challenging atmospheric condition for eddy-flux measurements, we use the renormalized group (RNG) k-ϵ turbulence model to investigate the main characteristics of stably stratified canopy flows in complex terrain. In this two-dimensional simulation, we imposed persistent constant heat flux at ground surface and linearly increasing cooling rate in the upper-canopy layer, vertically varying dissipative force from canopy drag elements, buoyancy forcing induced from thermal stratification and the hill terrain. These strong boundary effects keep nonlinearity in the two-dimensional Navier-Stokes equations high enough to generate turbulent behavior. The fundamental characteristics of nighttime canopy flow over complex terrain measured by the small number of available multi-tower advection experiments can be reproduced by this numerical simulation, such as (1) unstable layer in the canopy and super-stable layers associated with flow decoupling in deep canopy and near the top of canopy; (2) sub-canopy drainage flow and drainage flow near the top of canopy in calm night; (3) upward momentum transfer in canopy, downward heat transfer in upper canopy and upward heat transfer in deep canopy; and (4) large buoyancy suppression and weak shear production in strong stability.

  13. Deglacial and lake level fluctuation history recorded in cores, Beaver Lake, Upper Peninsula, Michigan

    USGS Publications Warehouse

    Fisher, Timothy G.; Whitman, Richard L.

    1999-01-01

    Sediment cores collected from the littoral and pelagic zones of Beaver Lake, Michigan record fluctuations in the water level of Lake Superior. Beaver Lake is a small 300 ha lake in Pictured Rocks National Lakeshore (PRNL) now separated from Lake Superior by a dune-capped barrier bar. Cores were collected using a vibracorer from a lake-ice platform in February 1997. A 2.85 m long core in 10 m of water contains well-sorted sand, rhythmites, peat, interbedded sand and gyttja, and is capped with 1 m of massive gyttja. A 9480 BP AMS age from the basal sand provides a minimum deglacial date for the area. Further analysis indicates a sand-dominated depositional environment from a low lake stand at approximately 8500 BP to present. An approximate 8800 BP red to gray sediment color transition records either the cessation of meltwater input from Lake Agassiz or receding ice, while a younger similarly colored transition, 6600 BP in age, likely records sediment reworking in the coastal zone. Four AMS ages on peat range from 8520 to 7340 BP and are indicative of the Houghton low phase. Burial of the peat by stratified sand and gyttja after 7340 BP indicates a rising lake level. Peat at a higher level in the lake basin, encountered in shallow littoral cores, ranges in age from 6800 to 6420 BP, which estimates a 0.91 m rise/century in lake level to the Nipissing level by 5000 BP.

  14. A Filtering Method For Gravitationally Stratified Flows

    SciTech Connect

    Gatti-Bono, Caroline; Colella, Phillip

    2005-04-25

    Gravity waves arise in gravitationally stratified compressible flows at low Mach and Froude numbers. These waves can have a negligible influence on the overall dynamics of the fluid but, for numerical methods where the acoustic waves are treated implicitly, they impose a significant restriction on the time step. A way to alleviate this restriction is to filter out the modes corresponding to the fastest gravity waves so that a larger time step can be used. This paper presents a filtering strategy of the fully compressible equations based on normal mode analysis that is used throughout the simulation to compute the fast dynamics and that is able to damp only fast gravity modes.

  15. Bayesian stratified sampling to assess corpus utility

    SciTech Connect

    Hochberg, J.; Scovel, C.; Thomas, T.; Hall, S.

    1998-12-01

    This paper describes a method for asking statistical questions about a large text corpus. The authors exemplify the method by addressing the question, ``What percentage of Federal Register documents are real documents, of possible interest to a text researcher or analyst?`` They estimate an answer to this question by evaluating 200 documents selected from a corpus of 45,820 Federal Register documents. Bayesian analysis and stratified sampling are used to reduce the sampling uncertainty of the estimate from over 3,100 documents to fewer than 1,000. A possible application of the method is to establish baseline statistics used to estimate recall rates for information retrieval systems.

  16. White dwarf stars with chemically stratified atmospheres

    NASA Technical Reports Server (NTRS)

    Muchmore, D.

    1982-01-01

    Recent observations and theory suggest that some white dwarfs may have chemically stratified atmospheres - thin layers of hydrogen lying above helium-rich envelopes. Models of such atmospheres show that a discontinuous temperature inversion can occur at the boundary between the layers. Model spectra for layered atmospheres at 30,000 K and 50,000 K tend to have smaller decrements at 912 A, 504 A, and 228 A than uniform atmospheres would have. On the basis of their continuous extreme ultraviolet spectra, it is possible to distinguish observationally between uniform and layered atmospheres for hot white dwarfs.

  17. Family communication in a population at risk for hypertrophic cardiomyopathy.

    PubMed

    Batte, Brittany; Sheldon, Jane P; Arscott, Patricia; Huismann, Darcy J; Salberg, Lisa; Day, Sharlene M; Yashar, Beverly M

    2015-04-01

    Encouraging family communication is an integral component of genetic counseling; therefore, we sought to identify factors impacting communication to family members at risk for Hypertrophic Cardiomyopathy (HCM). Participants (N = 383) completed an online survey assessing: 1) demographics (gender, genetic test results, HCM family history, and disease severity); 2) illness representations; 3) family functioning and cohesiveness; 4) coping styles; 5) comprehension of HCM autosomal dominant inheritance; and 6) communication of HCM risk information to at-risk relatives. Participants were a national sample of individuals with HCM, recruited through the Hypertrophic Cardiomyopathy Association. Data from 183 participants were analyzed using a logistic regression analysis, with family communication as a dichotomous dependent variable. We found that female gender and higher comprehension of autosomal dominant inheritance were significant predictors of participants' communication of HCM risk information to all their siblings and children. Our results suggest that utilizing interventions that promote patient comprehension (e.g., a teaching-focused model of genetic counseling) are important and may positively impact family communication within families with HCM.

  18. Reversible transition from a hypertrophic to a dilated cardiomyopathy

    PubMed Central

    Spillmann, Frank; Kühl, Uwe; Van Linthout, Sophie; Dominguez, Fernando; Escher, Felicitas; Schultheiss, Heinz‐Peter; Pieske, Burkert

    2015-01-01

    Abstract We report the case of a 17‐year‐old female patient with known hypertrophic cardiomyopathy and a Wolff‐Parkinson‐White syndrome. She came to our department for further evaluation of a new diagnosed dilated cardiomyopathy characterized by an enlargement of the left ventricle and a fall in ejection fraction. Clinically, she complained about atypical chest pain, arrhythmic episodes with presyncopal events, and dyspnea (NYHA III) during the last 6 months. Non‐invasive and invasive examinations including magnetic resonance imaging, electrophysiological examinations, and angiography did not lead to a conclusive diagnosis. Therefore, endomyocardial biopsies (EMBs) were taken to investigate whether a specific myocardial disease caused the impairment of the left ventricular function. EMB analysis resulted in the diagnosis of a virus‐negative, active myocarditis. Based on this diagnosis, an immunosuppressive treatment with prednisolone and azathioprine was started, which led to an improvement of cardiac function and symptoms within 3 months after initiating therapy. In conclusion, we show that external stress triggered by myocarditis can induce a reversible transition from a hypertrophic cardiomyopathy to a dilated cardiomyopathy phenotype. This case strongly underlines the need for a thorough and invasive examination of heart failure of unknown causes, including EMB investigations as recommend by the actual ESC position statement.

  19. Elastic Waves Green Functions For Stratified Medium

    NASA Astrophysics Data System (ADS)

    Albuquerque, E. L.; Ferreira, E. C.; Mauriz, P. W.

    Multiple scattering analysis of elastic waves propagating in a stratified medium is a powerful method to model seismic reflection signals, widely used in the exploration for oil and gas reservoirs. Reflection imaging and inversion method derive their exis- tence from the presence of singularities in the Earth's material properties that support the waves. Considering a Green's function formalism based on the {it frequency distri- bution} of the elastic wave spectra, we study their propagation within a model in which the Earth is treated as a stratified medium. The calculations are based on the linear response function approach, which is very convenient to deal with this kind of prob- lem. Both the displacement ({it space}) and the wavevector ({it space-time}) Green's functions are determined. A damping term gamma is included in a phenomenolog- ical way into the wavevector expression. In order to examine the waves' excitation, we also determine, by using the fluctuation-dissipation theorem, their power spectra, which have many interesting properties.

  20. Stratified coastal ocean interactions with tropical cyclones

    PubMed Central

    Glenn, S. M.; Miles, T. N.; Seroka, G. N.; Xu, Y.; Forney, R. K.; Yu, F.; Roarty, H.; Schofield, O.; Kohut, J.

    2016-01-01

    Hurricane-intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 °C and up to 11 °C) over a wide swath of the continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene's accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward. PMID:26953963

  1. Mixing and Vorticity Structure in Stratified Oceans

    NASA Astrophysics Data System (ADS)

    Magdalena Matulka, Anna; Redondo, Jose M.

    2010-05-01

    Several series of experiments in stratified and in rotating/stratified decaying flows after a grid is used to stir the two layer stable fluid brine and fresh water set up. (Matulka 2009). We measure by comparing the gained potential energy with the available kinetic energy AKE, the relative efficiency of mixing. The experiments in stratified rotating flows with grid driven turbulence were both periodic (quasi stationary) and non-monotonic (decaying) forcing(Matulka et al. 2008). A complex Parameter Space Using Ri, Ro, Re is used to compare field, experimental and numerical observations on the mixing structure and Topology(Redondo 2004, Redondo et al 1996) of the Stratified Rotating Flows. The horizontal spectra changes appreciable with slopes from 1.1 to 5, but relevant to dispersion, vorticity and local circulation, not only the spectral slope is important, but also the initial topology and forcing of the AKE (in Elliptical, vortex core regions ) or in hyperbolic regions dominated by shear). Using multi-fractal geometry as well, we can establish now a theoretical pattern for the turbulence behavior that is reflected in the different descriptors (volume fraction, velocity and vorticity and thus obtain a certain classification relating D3 and the sum (integral) of the different fractal dimensions D2 for different levels of scalar (volume fraction intensity or temperature). Vorticity evolution is smoother and different than that of scalar or tracer density. The correlation between the local Ri and the fractal dimension detected from energy or entropy is good. Using multi-fractal geometry we can also establish certain regions of higher local activity used to establish the geometry of the turbulence mixing, that needs to be studied in detail when interpreting the complex balance between the direct 3D Kolmogorov type cascade and the Inverse 2D Kraichnan type cascade. A large collection of SAR images obtained from three European coastal areas (Gade and Redondo 1999

  2. Stratified coastal ocean interactions with tropical cyclones.

    PubMed

    Glenn, S M; Miles, T N; Seroka, G N; Xu, Y; Forney, R K; Yu, F; Roarty, H; Schofield, O; Kohut, J

    2016-01-01

    Hurricane-intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 °C and up to 11 °C) over a wide swath of the continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene's accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward. PMID:26953963

  3. Jet-mixing of initially stratified flows

    NASA Astrophysics Data System (ADS)

    Wright, Stuart; Markides, Christos; Matar, Omar

    2015-11-01

    Low pipeline velocities in the oil-and-gas industry generally lead to liquid-liquid flows stratifying due to density differences. Pipeline stratified flows inherently have no single point for sub-sampling and phase slip leads to in situ phase fractions differing from input volume fractions. Establishing representative or average properties and phase fractions is therefore difficult for industry. This leads to sampling errors through measurement uncertainty. In-line mixing overcomes liquid-liquid stratification, establishing a liquid-liquid dispersion that minimises slip between phases. Here, we use jets-in-crossflow (JICF) as a means of mixing. We present results of CFD simulations using the volume-of- fluid method that demonstrate the breakup of stratification as a result of the application of JICF. A number of simple jet configurations are described, and their effectiveness in generating dispersions is compared. We also present preliminary experimental results based on the use of a matched-refractive-index method, laser-induced fluorescence, particle-tracking- and particle-image-velocimetry. Funding from Cameron for Ph.D. studentship (SW) gratefully acknowledged.

  4. Energy transfer in stably stratified turbulence

    NASA Astrophysics Data System (ADS)

    Kimura, Yoshifumi; Herring, Jackson

    2015-11-01

    Energy transfer in forced stable stratified turbulence is investigated using pseudo-spectral DNS of the Navier-Stokes equations under the Boussinesq approximation with 10243 grid points. Making use of the Craya-Herring decomposition, the velocity field is decomposed into vortex (Φ1) and wave (Φ2) modes. To understand the anisotropy of stably stratified turbulence, the energy flues in terms of the spherical, the horizontal and the vertical wave numbers, are investigated for the total kinetic, Φ1, Φ2 energies, respectively. Among the three fluxes, the spherical and the horizontal look similar for strong stratification, and Φ1 flux shows a wave number region of constant value, which implies Kolmogorov's inertial range. The corresponding spectral power are, however, k - 5 / 2 for the spherical and k⊥- 5 / 3 for the horizontal cases. In contrast to these, the vertical energy fluxes show completely different features. We have observed the saturation spectrum E (kz) ~ CN2kz-3 for strong stratification as before, but the mechanism to produce this spectrum seems different from the Kolmogorov picture.

  5. Stratified coastal ocean interactions with tropical cyclones

    NASA Astrophysics Data System (ADS)

    Glenn, S. M.; Miles, T. N.; Seroka, G. N.; Xu, Y.; Forney, R. K.; Yu, F.; Roarty, H.; Schofield, O.; Kohut, J.

    2016-03-01

    Hurricane-intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 °C and up to 11 °C) over a wide swath of the continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene's accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward.

  6. Stratified coastal ocean interactions with tropical cyclones.

    PubMed

    Glenn, S M; Miles, T N; Seroka, G N; Xu, Y; Forney, R K; Yu, F; Roarty, H; Schofield, O; Kohut, J

    2016-01-01

    Hurricane-intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 °C and up to 11 °C) over a wide swath of the continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene's accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward.

  7. Lake Eyre

    Atmospheric Science Data Center

    2013-04-16

    ...   View Larger Image Lake Eyre is a large salt lake situated between two deserts in one of Australia's driest regions. ... the effect of sunglint at the nadir camera view angle. Dry, salt encrusted parts of the lake appear bright white or gray. Purple areas have ...

  8. Effects of spatial allocation and parameter variability on lakewide estimates from surveys of Lake Superior, North America’s largest lake

    EPA Science Inventory

    Lake Superior was sampled in 2011 using a Generalized Random Tessellation Stratified design (n=54 sites) to characterize biological and chemical properties of this huge aquatic resource, with statistical confidence. The lake was divided into two strata (inshore <100m and offsh...

  9. Down Syndrome with Complete Atrioventricular Septal Defect, Hypertrophic Cardiomyopathy, and Pulmonary Vein Stenosis.

    PubMed

    Mahadevaiah, Guruprasad; Gupta, Manoj; Ashwath, Ravi

    2015-10-01

    The prevalence of congenital heart disease in infants with Down syndrome is 40%, compared with 0.3% in children who have normal chromosomes. Atrioventricular and ventricular septal defects are often associated with chromosomal aberrations, such as in trisomy 21, whereas hypertrophic cardiomyopathy is chiefly thought to be secondary to specific gene mutations. We found only one reported case of congenital hypertrophic cardiomyopathy and atrioventricular septal defect in an infant with Down syndrome. Here, we report atrioventricular septal defect, hypertrophic cardiomyopathy, and pulmonary vein stenosis in a neonate with Down syndrome-an apparently unique combination. In addition, we discuss the relevant medical literature.

  10. Down Syndrome with Complete Atrioventricular Septal Defect, Hypertrophic Cardiomyopathy, and Pulmonary Vein Stenosis

    PubMed Central

    Mahadevaiah, Guruprasad; Gupta, Manoj

    2015-01-01

    The prevalence of congenital heart disease in infants with Down syndrome is 40%, compared with 0.3% in children who have normal chromosomes. Atrioventricular and ventricular septal defects are often associated with chromosomal aberrations, such as in trisomy 21, whereas hypertrophic cardiomyopathy is chiefly thought to be secondary to specific gene mutations. We found only one reported case of congenital hypertrophic cardiomyopathy and atrioventricular septal defect in an infant with Down syndrome. Here, we report atrioventricular septal defect, hypertrophic cardiomyopathy, and pulmonary vein stenosis in a neonate with Down syndrome—an apparently unique combination. In addition, we discuss the relevant medical literature. PMID:26504441

  11. Hearing Profile in Patients with Dilated and Hypertrophic Cardiomyopathies

    PubMed Central

    El-Zarea, Gehan Abd El-Rahman; Hassan, Yasser Elsayed Mohamed; Mahmoud, Ahmed Mohamed Ahmed

    2016-01-01

    Introduction Cardiomyopathy may cause disruptions in the micro-vascular system of the stria vascularis in the cochlea, and, subsequently, may result in cochlear degeneration. Degeneration in the stria vascularis affects the physical and chemical processes in the organ of Corti, thereby causing a possible hearing impairment. The objective of this study was to assess the hearing profiles of patients with dilated and hypertrophic cardiomyopathies to determine the relationship between the degree of hearing loss and the degree and duration of the disease and to compare the dilated and hypertrophic cardiomyopathies as regards hearing profile. Methods In this case control study, we studied 21 patients (cases/study group/group 1) and 15 healthy individuals (controls/group 2). Six patients (group 1a) had hypertrophic cardiomyopathy (HCM), and 15 patients (group 1b) had dilated cardiomyopathy (DCM). The data were analyzed using the t-test, chi-squared test, Kruskal-Wallis test, and the Multiple Mann-Whitney test. Results The results of this study showed that 80% of those patients with DCM (group 1b) had bilateral sensorineural hearing loss (SNHL), and 100% of the patients with HCM (group 1a) had mild to severe bilateral sloping SNHL. Distortion Product Otoacoustic Emissions (DPOAEs) were present in 14% of the study group and in 100 % of the control group. The results of the measurements of auditory brainstem response (ABR) showed that 50% of the study group had abnormal latencies compared to the control group, and there was no correlation between the duration of the disease and the degree of hearing loss or DPOAE. Fifty percent of the patients with HCM and 35% of the patients with DCM had positive family histories of similar conditions, and 35% of those with HCM had a positive family history of sudden death. Conclusion The results of this study suggested that the link between heart disease and hearing loss and early identification of hearing loss in patients with

  12. Entrainment and mixing in stratified shear flows

    NASA Astrophysics Data System (ADS)

    Strang, Eric James

    1997-12-01

    The results of a laboratory experiment designed to study turbulent entrainment at sheared density interfaces are described. In the parameter ranges investigated the entrainment problem is mainly determined by two parameters, the bulk Richardson number RiB = /Delta bD//Delta U2 and the frequency ratio fN = ND//Delta U. When RiB > 1.5, the buoyancy effects play a governing role, whence interfacial instabilities locally mix heavy and light fluids. The nature of interfacial instabilities is governed by RiB or a related quantity, the mean local gradient Richardson number /overline [Ri]g=/overline [N(z)]2/(/overline[/partial u//partial z)]2, where N(z) is the Brunt-Vaisala frequency local to the interface. When RiB < 5 (or /overline [Rig] < 1), the interfacial mixing is dominated by Kelvin- Helmholtz (K-H) instabilities. Interfacial swelling as a result of the collective breakdown of K-H billows into turbulence persists for a time dictated by the rates of local generation and removal of mixed fluid, and the two processes appear to be coadjutant (with a maximum flux Richardson number or mixing efficiency of Rif ~ 0.15-0.4) when RiB≃ 3-5. At RiB~ 5, the K-H regime transitions to a new regime wherein the interface is dominated by interfacial/Holmboe wave instabilities. Here, the entrainment rates are much smaller and there is no evidence of interfacial swelling. In the K-H regime, the swelling of the interface introduces its own forcing time scale, which excites and radiates internal waves in the lower layer if it is continuously stratified. Consequently, the amount of energy available for entrainment decreases and, depending on fN, the entrainment velocities in the linearly stratified case can be substantially smaller than the two-layer case (up to 50%). In the interfacial/Holmboe wave breaking regime, internal wave radiation to the bottom layer is much smaller, so as the difference in entrainment rates of the two-layer and linearly stratified cases. Furthermore, when Ri

  13. Measurement of High Reynolds Number Near-Field Turbulent Sphere Wakes under Stratified Conditions

    NASA Astrophysics Data System (ADS)

    Kalumuck, Kenneth; Brandt, Alan; Decker, Kirk; Shipley, Kara

    2015-11-01

    To characterize the near-field of a stratified wake at Reynolds numbers, Re = 2 x 105 - 106, experiments were conducted with a large diameter (0.5 m) sphere towed through a thermally stratified fresh water lake. Stratification produced BV frequencies, N, up to 0.07/s (42 cph) resulting in Froude numbers F = U/ND >= 15. The submerged sphere and associated instrumentation including two Acoustic Doppler Velocimeters (ADVs) and an array of fast response thermistors were affixed to a common frame towed over a range of speeds. Three components of the instantaneous wake velocities were obtained simultaneously at two cross-wake locations with the ADVs while density fluctuations were inferred from temperature measurements made by the thermistors. These measurements were used to determine the mean, rms, and spectra of all three components of the turbulent velocity field and density fluctuations at multiple locations. The turbulence power spectra follow the expected -5/3 slope with wavenumber. Existing stratified near-field wake data for spheres are for Re =104 and less, and only a very limited set of data under unstratified conditions exists at these large values of Re. Those data are primarily measurements of the sphere drag, surface pressure distribution, and separation rather than in wake turbulence. Advances in CFD modeling have enabled simulations at these high Reynolds numbers without quantitative data available for validation. Sponsored by ONR Turbulence and Wakes program.

  14. Monte Carlo stratified source-sampling

    SciTech Connect

    Blomquist, R.N.; Gelbard, E.M.

    1997-09-01

    In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo {open_quotes}eigenvalue of the world{close_quotes} problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. The original test-problem was treated by a special code designed specifically for that purpose. Recently ANL started work on a method for dealing with more realistic eigenvalue of the world configurations, and has been incorporating this method into VIM. The original method has been modified to take into account real-world statistical noise sources not included in the model problem. This paper constitutes a status report on work still in progress.

  15. Spectral calculations in stably stratified turbulence.

    PubMed

    Dutta, Kishore; Nandy, Malay K

    2014-12-01

    We perform a Leslie-type perturbative treatment on stably stratified turbulence with Boussinesq approximation, where the buoyancy terms in the corresponding dynamical equations are treated as perturbations against the isotropic background fields. Thus we calculate the anisotropic corrections to various correlation functions, namely, velocity-velocity, temperature-temperature, and velocity-temperature correlations, up to second order in this scheme. We find that the prefactors associated with the anisotropic corrections depend on the energy flux, scalar flux, Kolmogorov constant, Batchelor constant, and the eddy-damping amplitudes. The correlation functions further yield the anisotropic parts of the energy and mean-square temperature spectra as k(-3) and the anisotropic buoyancy spectrum as k(-7/3). The resulting angle-dependent energy density is found to be concentrated predominantly around the vertical wave vector signifying layered structures in the physical space. PMID:25615193

  16. Emergence of helicity in rotating stratified turbulence

    NASA Astrophysics Data System (ADS)

    Marino, Raffaele; Mininni, Pablo D.; Rosenberg, Duane; Pouquet, Annick

    2013-03-01

    We perform numerical simulations of decaying rotating stratified turbulence and show, in the Boussinesq framework, that helicity (velocity-vorticity correlation), as observed in supercell storms and hurricanes, is spontaneously created due to an interplay between buoyancy and rotation common to large-scale atmospheric and oceanic flows. Helicity emerges from the joint action of eddies and of inertia-gravity waves (with inertia and gravity with respective associated frequencies f and N), and it occurs when the waves are sufficiently strong. For N/f<3 the amount of helicity produced is correctly predicted by a quasilinear balance equation. Outside this regime, and up to the highest Reynolds number obtained in this study, namely Re≈10000, helicity production is found to be persistent for N/f as large as ≈17, and for ReFr2 and ReRo2, respectively, as large as ≈100 and ≈24000.

  17. Domain Growth Kinetics in Stratifying Foam Films

    NASA Astrophysics Data System (ADS)

    Zhang, Yiran; Sharma, Vivek

    2015-03-01

    Baking bread, brewing cappuccino, pouring beer, washing dishes, shaving, shampooing, whipping eggs and blowing bubbles all involve creation of aqueous foam films. Typical foam films consist of two surfactant-laden surfaces that are μ 5 nm - 10 micron apart. Sandwiched between these interfacial layers is a fluid that drains primarily under the influence of viscous and interfacial forces, including disjoining pressure. Interestingly, for certain low molecular weight surfactants, a layered ordering of micelles inside the foam films (thickness <100 nm) leads to a stepwise thinning phenomena called stratification. We experimentally elucidate the influence of these different driving forces, and confinement on drainage kinetics of horizontal stratifying foam films. Thinner, darker domains spontaneously grow within foam films. Quantitative characterization of domain growth visualized in a using Scheludko-type thin film cell and a theoretical model based on lubrication analysis, provide critical insights into hydrodynamics of thin foam films, and the strength and nature of surface forces, including supramolecular oscillatory structural forces.

  18. On turbulence in a stratified environment

    NASA Astrophysics Data System (ADS)

    Sarkar, Sutanu

    2015-11-01

    John Lumley, motivated by atmospheric observations, made seminal contributions to the statistical theory (Lumley and Panofsky 1964, Lumley 1964) and second-order modeling (Zeman and Lumley 1976) of turbulence in the environment. Turbulent processes in the ocean share many features with the atmosphere, e.g., shear, stratification, rotation and rough topography. Results from direct and large eddy simulations of two model problems will be used to illustrate some of the features of turbulence in a stratified environment. The first problem concerns a shear layer in nonuniform stratification, a situation typical of both the atmosphere and the ocean. The second problem, considered to be responsible for much of the turbulent mixing that occurs in the ocean interior, concerns topographically generated internal gravity waves. Connections will be made to data taken during observational campaigns in the ocean.

  19. Direct multiangle solution for poorly stratified atmospheres.

    PubMed

    Kovalev, Vladimir; Wold, Cyle; Petkov, Alexander; Hao, Wei Min

    2012-09-01

    The direct multiangle solution is considered, which allows improving the scanning lidar-data-inversion accuracy when the requirement of the horizontally stratified atmosphere is poorly met. The signal measured at zenith or close to zenith is used as a core source for extracting optical characteristics of the atmospheric aerosol loading. The multiangle signals are used as auxiliary data to extract the vertical transmittance profile from the zenith signal. Details of the retrieval methodology are considered that eliminate, or at least soften, some specific ambiguities in the multiangle measurements in horizontally heterogeneous atmospheres. Simulated and experimental elastic lidar data are presented that illustrate the essentials of the data-processing technique. Finally, the prospects of the utilization of high-spectral-resolution lidar in the multiangle mode are discussed. PMID:22945162

  20. Stably stratified canopy flow in complex terrain

    NASA Astrophysics Data System (ADS)

    Xu, X.; Yi, C.; Kutter, E.

    2014-11-01

    The characteristics of stably stratified canopy flows in complex terrain are investigated by employing the Renormalized Group (RNG) k-ɛ turbulence model. In this two-dimensional simulation, we imposed persistent constant heat flux at ground surface and linearly increasing cooling rate in the upper canopy layer, vertically varying dissipative force from canopy drag elements, buoyancy forcing induced from thermal stratification and the hill terrain. These strong boundary effects keep nonlinearity in the two-dimensional Navier-Stokes equations high enough to generate turbulent behavior. The fundamental characteristics of nighttime canopy flow over complex terrain measured by a few multi-tower advection experiments can be produced by this numerical simulation, such as: (1) unstable layer in the canopy, (2) super-stable layer associated with flow decoupling in deep canopy and near the top of canopy, (3) upward momentum transfer in canopy, and (4) large buoyancy suppression and weak shear production in strong stability.

  1. Information content of household-stratified epidemics.

    PubMed

    Kinyanjui, T M; Pellis, L; House, T

    2016-09-01

    Household structure is a key driver of many infectious diseases, as well as a natural target for interventions such as vaccination programs. Many theoretical and conceptual advances on household-stratified epidemic models are relatively recent, but have successfully managed to increase the applicability of such models to practical problems. To be of maximum realism and hence benefit, they require parameterisation from epidemiological data, and while household-stratified final size data has been the traditional source, increasingly time-series infection data from households are becoming available. This paper is concerned with the design of studies aimed at collecting time-series epidemic data in order to maximize the amount of information available to calibrate household models. A design decision involves a trade-off between the number of households to enrol and the sampling frequency. Two commonly used epidemiological study designs are considered: cross-sectional, where different households are sampled at every time point, and cohort, where the same households are followed over the course of the study period. The search for an optimal design uses Bayesian computationally intensive methods to explore the joint parameter-design space combined with the Shannon entropy of the posteriors to estimate the amount of information in each design. For the cross-sectional design, the amount of information increases with the sampling intensity, i.e., the designs with the highest number of time points have the most information. On the other hand, the cohort design often exhibits a trade-off between the number of households sampled and the intensity of follow-up. Our results broadly support the choices made in existing epidemiological data collection studies. Prospective problem-specific use of our computational methods can bring significant benefits in guiding future study designs. PMID:27663787

  2. Laminar flame propagation in a stratified charge

    NASA Astrophysics Data System (ADS)

    Ra, Youngchul

    The propagation of laminar flame from a rich or stoichiometric mixture to a lean mixture in a stratified methane-air charge was investigated experimentally and numerically. Emphasis was on the understanding of the flame behavior in the transition region; in particular, on the mechanism of burning velocity enhancement in this region. In the experimental setup, mixtures of two different equivalence ratios were separated by a soap bubble in a spherical constant volume combustion vessel. The richer mixture inside the bubble was ignited by a focused laser beam. The flame development was observed by Schlieren technique and flame speeds were measured by heat release analysis of the pressure data. An one-dimensional, time- dependant numerical simulation of the flame propagation in a charge with step-stratification was used to interpret the experimental results. Both the experimental and numerical studies showed that the instantaneous flame speed depended on the previous flame history. Thus a `strong' (with mixture equivalence ratio close to stoichiometric) flame can sustain propagation into finite regions of substantially lean equivalence ratio. Both thermal and chemical effects were crucial for explaining the mechanism of the flame speed enhancement in the transition period. Because of the presence of this `back- support' effect, the usual concept of specifying the burning velocity as a function of the end gas state is inadequate for a stratified charge. A simple correlation for instantaneous flame velocity based on the local burned gas temperature is developed. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253- 1690.)

  3. Vortex Formation in Vertically Stratified Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Stewart, Glen R.

    2013-10-01

    A central problem of planet formation is how to form large planetesimals in a turbulent protoplanetary disk. Recent work suggests that MRI turbulence would excite such large velocities that the planetesimals would collisionally fragment rather than grow. The structure of chondritic meteorites indicates a gentle nebular environment where chondrules are sorted by size and cemented together rapidly. Although it is well established that anticyclones can concentrate particles that are weakly coupled to the gas in protoplanetary disks, the conditions required for the formation and long-time stability of anticyclones in a vertically stratified disk are still highly uncertain. Fully three dimensional fluid dynamic simulations of protoplanetary disks are computationally expensive when one requires a computational domain that is large compared to the vertical scale height of the disk. An alternative simulation approach is to use potential temperature as the vertical coordinate so that the equations of motion resemble the shallow water equations (Dowling et al. 1998). We have therefore modified a multilayer shallow water simulation code to model the formation of vortices in a vertically stratified protoplanetary disk with a radial entropy gradient. Vertical stratification of the disk is modeled by using multiple layers, where each layer has a different constant value of the entropy. By forcing a slope in the interfaces between the layers, we impose a radial entropy gradient in the disk. Radiative heating and cooling causes vertical mass exchange between adjacent constant entropy layers according to a Newton cooling formula. We find that the formation of anticyclones is robust, and that these vortices actively excite density waves, which in turn, transport angular momentum through the disk. Our simulations therefore yield new insights on how the dusty dead zones of protoplanetary disks can transport angular momentum through the disk by purely hydrodynamic processes. Support

  4. Information content of household-stratified epidemics.

    PubMed

    Kinyanjui, T M; Pellis, L; House, T

    2016-09-01

    Household structure is a key driver of many infectious diseases, as well as a natural target for interventions such as vaccination programs. Many theoretical and conceptual advances on household-stratified epidemic models are relatively recent, but have successfully managed to increase the applicability of such models to practical problems. To be of maximum realism and hence benefit, they require parameterisation from epidemiological data, and while household-stratified final size data has been the traditional source, increasingly time-series infection data from households are becoming available. This paper is concerned with the design of studies aimed at collecting time-series epidemic data in order to maximize the amount of information available to calibrate household models. A design decision involves a trade-off between the number of households to enrol and the sampling frequency. Two commonly used epidemiological study designs are considered: cross-sectional, where different households are sampled at every time point, and cohort, where the same households are followed over the course of the study period. The search for an optimal design uses Bayesian computationally intensive methods to explore the joint parameter-design space combined with the Shannon entropy of the posteriors to estimate the amount of information in each design. For the cross-sectional design, the amount of information increases with the sampling intensity, i.e., the designs with the highest number of time points have the most information. On the other hand, the cohort design often exhibits a trade-off between the number of households sampled and the intensity of follow-up. Our results broadly support the choices made in existing epidemiological data collection studies. Prospective problem-specific use of our computational methods can bring significant benefits in guiding future study designs.

  5. Stratified charge rotary engine combustion studies

    NASA Technical Reports Server (NTRS)

    Shock, H.; Hamady, F.; Somerton, C.; Stuecken, T.; Chouinard, E.; Rachal, T.; Kosterman, J.; Lambeth, M.; Olbrich, C.

    1989-01-01

    Analytical and experimental studies of the combustion process in a stratified charge rotary engine (SCRE) continue to be the subject of active research in recent years. Specifically to meet the demand for more sophisticated products, a detailed understanding of the engine system of interest is warranted. With this in mind the objective of this work is to develop an understanding of the controlling factors that affect the SCRE combustion process so that an efficient power dense rotary engine can be designed. The influence of the induction-exhaust systems and the rotor geometry are believed to have a significant effect on combustion chamber flow characteristics. In this report, emphasis is centered on Laser Doppler Velocimetry (LDV) measurements and on qualitative flow visualizations in the combustion chamber of the motored rotary engine assembly. This will provide a basic understanding of the flow process in the RCE and serve as a data base for verification of numerical simulations. Understanding fuel injection provisions is also important to the successful operation of the stratified charge rotary engine. Toward this end, flow visualizations depicting the development of high speed, high pressure fuel jets are described. Friction is an important consideration in an engine from the standpoint of lost work, durability and reliability. MSU Engine Research Laboratory efforts in accessing the frictional losses associated with the rotary engine are described. This includes work which describes losses in bearing, seal and auxillary components. Finally, a computer controlled mapping system under development is described. This system can be used to map shapes such as combustion chamber, intake manifolds or turbine blades accurately.

  6. Stratified scaffold design for engineering composite tissues.

    PubMed

    Mosher, Christopher Z; Spalazzi, Jeffrey P; Lu, Helen H

    2015-08-01

    A significant challenge to orthopaedic soft tissue repair is the biological fixation of autologous or allogeneic grafts with bone, whereby the lack of functional integration between such grafts and host bone has limited the clinical success of anterior cruciate ligament (ACL) and other common soft tissue-based reconstructive grafts. The inability of current surgical reconstruction to restore the native fibrocartilaginous insertion between the ACL and the femur or tibia, which minimizes stress concentration and facilitates load transfer between the soft and hard tissues, compromises the long-term clinical functionality of these grafts. To enable integration, a stratified scaffold design that mimics the multiple tissue regions of the ACL interface (ligament-fibrocartilage-bone) represents a promising strategy for composite tissue formation. Moreover, distinct cellular organization and phase-specific matrix heterogeneity achieved through co- or tri-culture within the scaffold system can promote biomimetic multi-tissue regeneration. Here, we describe the methods for fabricating a tri-phasic scaffold intended for ligament-bone integration, as well as the tri-culture of fibroblasts, chondrocytes, and osteoblasts on the stratified scaffold for the formation of structurally contiguous and compositionally distinct regions of ligament, fibrocartilage and bone. The primary advantage of the tri-phasic scaffold is the recapitulation of the multi-tissue organization across the native interface through the layered design. Moreover, in addition to ease of fabrication, each scaffold phase is similar in polymer composition and therefore can be joined together by sintering, enabling the seamless integration of each region and avoiding delamination between scaffold layers.

  7. Assessing iron dynamics in the release from a stratified reservoir

    USGS Publications Warehouse

    Ashby, S.L.; Faulkner, S.P.; Gambrell, R.P.; Smith, B.A.

    2004-01-01

    Field and laboratory studies were conducted to describe the fate of total, dissolved, and ferrous (Fe2.) iron in the release from a stratified reservoir with an anoxic hypolimnion. Concentrations of total iron in the tail water indicated a first order removal process during a low flow release (0.6 m3sec1), yet negligible loss was observed during a period of increased discharge (2.8 m 3 sec-1). Dissolved and ferrous iron concentrations in the tailwater were highly variable during both release regimes and did not follow responses based on theoretical predictions. Ferrous iron concentrations in unfiltered samples were consistently greater than concentrations observed in samples filtered separately through 0.4, 0.2, and 0.1 ??m filters. Total iron removal in laboratory studies followed first order kinetics, but was twice that rate (0.077 mg.L-1 .hr 1) observed during low flow discharge in the tailwater (0.036 mg. L1 .hr1). Dissolved and ferrous iron losses in laboratory studies were rapid (???75% in the first 15 minutes and 95% within 1 hour), followed theoretical predictions, and were much faster than observations in the tailwater (???30% within the first hour). The presence of particulate forms of ferrous iron in the field and differences in removal rates observed in field and laboratory studies indicate a need for improved field assessment techniques and consideration of complexation reactions when assessing the dynamics of iron in reservoir releases and downstream impacts as a result of operation regimes. ?? Copyright by the North American Lake Management Society 2004.

  8. Keloids and Hypertrophic Scars: A Spectrum of Clinical Challenges.

    PubMed

    Trace, Anthony P; Enos, Clinton W; Mantel, Alon; Harvey, Valerie M

    2016-06-01

    Since their earliest description, keloids and hypertrophic scars have beleaguered patients and clinicians alike. These scars can be aesthetically disfiguring, functionally debilitating, emotionally distressing, and psychologically damaging, culminating in a significant burden for patients. Our current understanding of keloid pathophysiology has grown and continues to advance while molecular biology, genetics, and technology provide ever-deepening insight into the nature of wound healing and the pathologic perturbations thereof. Greater understanding will lead to the development and application of refined therapeutic modalities. This article provides an overview of our current understanding of keloids, highlighting clinical characteristics and diagnostic criteria while providing a comprehensive summary of the many therapeutic modalities available. The proposed mechanism, application, adverse events, and reported efficacy of each modality is evaluated, and current recommendations are summarized. PMID:26894654

  9. Hypertrophic osteoarthropathy in patient with Crohn's disease: a case report.

    PubMed

    Rhee, Sung-Min; Park, Ki Jeong; Ha, Yong-Chan

    2014-05-01

    Numerous causes of hypertrophic osteoarthropathy (HOA) have been reported. Commonly, secondary osteoarthropathy accompanies pulmonary diseases such as carcinoma of the lung, pleural tumors, lung abscesses, and bronchiectasis. However, HOA in inflammatory bowel disease is a rare complication. There are only a few reports of secondary HOA with Crohn's disease. Our purpose was to report another case of HOA in Crohn's disease. We describe a case of a 27-year-old man with underlying Crohn's disease presenting with 2 years of pain in multiple joints. Radiographic findings suggested HOA in extremities. We performed a conservative treatment including medication and rehabilitations. The patient's symptoms were much improved at the latest follow-up. Although numerous studies on HOA have been published, the pathogenesis of HOA is still unclear. Various treatment modalities were recommended but further studies to uncover the pathogenesis of HOA with Crohn's disease and to establish a treatment modality are needed. PMID:25025001

  10. Hypertrophic cardiomyopathy with Jeune syndrome: The first reported case.

    PubMed

    Güvenç, Osman; Sündüs Uygun, Saime; Çimen, Derya; Aslan, Eyüp; Annagür, Ali

    2016-09-01

    Jeune syndrome (Asphyxiating thoracic dysplasia) is a rare dystrophy of the skeleton, inherited as an autosomal recessive condition. Patients develop a narrowed thorax, rhizomelic dwarfism, and hepatic, renal, and pancreatic abnormalities. High rates of pulmonary hypoplasia and pulmonary hypertension have been reported. Some patients die in early stages of life due to respiratory failure. The case of a patient referred with a history of severe asphyxiating birth, who had been diagnosed with Jeune syndrome and later hypertrophic cardiomyopathy (HCM) upon echocardiographic examination is described in the present report. This rare disease is discussed with respect to the current literature, as the present is the first reported case to be accompanied by HCM. PMID:27665332

  11. Clinical utility of natriuretic peptides and troponins in hypertrophic cardiomyopathy.

    PubMed

    Kehl, Devin W; Buttan, Anshu; Siegel, Robert J; Rader, Florian

    2016-09-01

    The diagnosis of hypertrophic cardiomyopathy (HCM) is based on clinical, echocardiographic and in some cases genetic findings. However, prognostication remains limited except in the subset of patients with high-risk indicators for sudden cardiac death. Additional methods are needed for risk stratification and to guide clinical management in HCM. We reviewed the available data regarding natriuretic peptides and troponins in HCM. Plasma levels of natriuretic peptides, and to a lesser extent serum levels of troponins, correlate with established disease markers, including left ventricular thickness, symptom status, and left ventricular hemodynamics by Doppler measurements. As a reflection of left ventricular filling pressure, natriuretic peptides may provide an objective measure of the efficacy of a specific therapy. Both natriuretic peptides and troponins predict clinical risk in HCM independently of established risk factors, and their prognostic power is additive. Routine measurement of biomarker levels therefore may be useful in the clinical evaluation and management of patients with HCM.

  12. Hypertrophic osteoarthropathy manifested with isolated calcaneal periostitis in bone scintigraphy.

    PubMed

    Moralidis, Efstratios; Gerasimou, Georgios; Theodoridou, Athina; Hilidis, Ilias; Mylonaki, Efrosyni; Gotzamani-Psarrakou, Anna

    2010-05-01

    Hypertrophic osteoarthropathy (HOA) is an incompletely understood syndrome characterized by digital clubbing and periosteal proliferation of long bones and it is commonly associated with primary lung tumors. Bone scintigraphy is a sensitive method in detecting HOA and characteristic findings have been reported. We present the case of a man with newly diagnosed non-small cell lung cancer, unremarkable clinical examination and blood tests and no digital clubbing. During disease staging, however, bone scintigraphy showed intense calcaneal cortical proliferation bilaterally without involvement of other parts of the skeleton. Cortical reaction of both calcanei resolved significantly after chemotherapy. This case indicates that HOA may manifest with isolated calcaneal periostitis bilaterally, which is a new addition to the literature.

  13. Ehlers-Danlos Syndrome associated with cardiomyopathy hypertrophic obstructive.

    PubMed

    Pinto, Raimundo José Almeida de Oliveira; Santos, Adaílton Araújo dos; Azevedo, Mablo de Castro; Meira, Saulo Sacramento

    2015-01-01

    Ehlers-Danlos syndrome is a rare clinical condition caused by a genetic change that results in the formation of structurally or functionally altered collagen. The clinical manifestations are varied, being the most obvious skin hypermotility and increased joint flexibility, although other systems - such as cardiovascular, respiratory and neurological - may also be affected. This paper presents the report of a patient who sought medical attention with complaints of atypical chest pain. Clinical evaluation enabled hypothetical diagnosis of hypertrophic obstructive cardiomyopathy and Ehlers-Danlos syndrome. Initial electrocardiogram, echocardiogram and 24 hours holter allowed the confirmation of the first hypothesis. A skin biopsy performed later associated clinical data and confirmed the second hypothesis. PMID:26312722

  14. Surgery management of rare hypertrophic frenum in an infant.

    PubMed

    Stroppa, Sheila de Carvalho; da Silva, Juliana Yassue Barbosa; Tavares, Maria Cristina Reis; Duda, João Gilberto; Losso, Estela Maris

    2014-01-01

    To report a rare case of a lateral frenum hypertrophy in an infant, this paper describes the case of a girl who came to a first dental appointment when she was 4 months old. A hypertrophic lateral frenum in the upper left canine region was detected. A great depression in the gingival rodet separated the anterior maxillary segment from the posterior one and also decreased the lip mobility in this region. A frenectomy was performed when the patient was 11 months old and the clinical follow-up was done up to the age of 30 months. There was normalization in the vestibular insertion of the lateral frenum, lip mobility, physiological development of the maxilla, and eruption of the upper incisors, canines, and first primary molars. Infants should go to a dental examination precociously in order to detect possible congenital and development alterations. PMID:25180104

  15. Hypertrophic cardiomyopathy and ultra-endurance running - two incompatible entities?

    PubMed

    Wilson, Mathew G; Chandra, Navin; Papadakis, Michael; O'Hanlon, Rory; Prasad, Sanjay K; Sharma, Sanjay

    2011-01-01

    Regular and prolonged exercise is associated with increased left ventricular wall thickness that can overlap with hypertrophic cardiomyopathy (HCM). Differentiating physiological from pathological hypertrophy has important implications, since HCM is the commonest cause of exercise-related sudden cardiac death in young individuals. Most deaths have been reported in intermittent 'start-stop' sports such as football (soccer) and basketball. The theory is that individuals with HCM are unable to augment stroke volume sufficiently to meet the demands of endurance sports and are accordingly 'selected-out' of participation in such events. We report the case of an ultra-endurance athlete with 25 years of > 50 km competitive running experience, with genetically confirmed HCM; thereby demonstrating that these can be two compatible entities.

  16. Infection level of monogenean gill parasite, Diplozoon kashmirensis (Monogenea, Polyopisthocotylea) in the Crucian Carp, Carassius carassius from lake ecosystems of an altered water quality: What factors do have an impact on the Diplozoon infection?

    PubMed

    Zargar, U R; Chishti, M Z; Yousuf, A R; Fayaz, A

    2012-10-26

    Monogeneans are of great interest to the ecologists because of their simple life cycle and are considered as one of the important and sensitive parasites to any changes in water quality. The monogenean gill parasite, Diplozoon kashmirensis of the Carassius carassius was examined with the aim to evaluate the infection level and the factors influencing the infection. Our results showed that highest prevalence (34.22%) of D. kashmirensis was in the lake having high trophic status and least prevalence (10.90%) in the lake having least trophic status. Infection levels were significantly higher at the basins/sites having deteriorated water quality in comparison to the basins/sites having better water quality. The combined effect of pollutants and eutrophication showed decrease in intensity of D. kashmirensis in one of the polluted/hypertrophied site in the hypertrophic lake (Anchar Lake), while as synergistic effect (i.e. increase) on prevalence and intensity was observed in one of the polluted/hypertrophied site in the eutrophic lake (Dal Lake). Sex was not an important factor influencing the D. kashmirensis in three lakes. The study showed that condition factor was significantly higher in the hypertrophic lake and in an uninfected fish. In addition microhabitat influenced the Diplozoon infection. Most preferable site for the D. kashmirensis was middle sector of the gill. Furthermore, the gill parasite showed significantly positive correlation (r(p)=0.6, P<0.05) with water temperature in the hypertrophic lake, thus showing the impact of water temperature on this parasite. It was concluded that intra lake differences, season, condition factor, microhabitat and water temperature influenced the infection of D. kashmirensis. It seems from the data that eutrophic and hypertrophic habitats were favourable for the D. kashmirensis. The D. kashmirensis showed both antagonistic and synergistic response to the combined effect of pollution and eutrophication.

  17. Idiopathic Hypertrophic Spinal Pachymeningitis with an Osteolytic Lesion

    PubMed Central

    Jee, Tae Keun; Lee, Sun-Ho; Kim, Eun-Sang

    2014-01-01

    Idiopathic hypertrophic spinal pachymeningitis (IHSP) is a chronic, progressive, inflammatory disorder characterized by marked fibrosis of the spinal dura mater with unknown etiology. According to the location of the lesion, it might induce neurologic deficits by compression of spinal cord and nerve root. A 58-year old female with a 3-year history of progressive weakness in both lower extremities was referred to our institute. Spinal computed tomography (CT) scan showed an osteolytic lesion involving base of the C6 spinous process with adjacent epidural mass. Magnetic resonance imaging (MRI) revealed an epidural mass involving dorsal aspect of cervical spinal canal from C5 to C7 level, with low signal intensity on T1 and T2 weighted images and non-enhancement on T1 weighted-enhanced images. We decided to undertake surgical exploration. At the operation field, there was yellow colored, thickened fibrous tissue over the dura mater. The lesion was removed totally, and decompression of spinal cord was achieved. Symptoms improved partially after the operation. Histopathologically, fibrotic pachymeninges with scanty inflammatory cells was revealed, which was compatible with diagnosis of idiopathic hypertrophic pachymeningitis. Six months after operation, motor power grade of both lower extremities was normal on physical examination. However, the patient still complained of mild weakness in the right lower extremity. Although the nature of IHSP is generally indolent, decompressive surgery should be considered for the patient with definite or progressive neurologic symptoms in order to prevent further deterioration. In addition, IHSP can present as an osteolytic lesion. Differential diagnosis with neoplastic disease, including giant cell tumor, is important. PMID:25328657

  18. Idiopathic hypertrophic spinal pachymeningitis with an osteolytic lesion.

    PubMed

    Jee, Tae Keun; Lee, Sun-Ho; Kim, Eun-Sang; Eoh, Whan

    2014-08-01

    Idiopathic hypertrophic spinal pachymeningitis (IHSP) is a chronic, progressive, inflammatory disorder characterized by marked fibrosis of the spinal dura mater with unknown etiology. According to the location of the lesion, it might induce neurologic deficits by compression of spinal cord and nerve root. A 58-year old female with a 3-year history of progressive weakness in both lower extremities was referred to our institute. Spinal computed tomography (CT) scan showed an osteolytic lesion involving base of the C6 spinous process with adjacent epidural mass. Magnetic resonance imaging (MRI) revealed an epidural mass involving dorsal aspect of cervical spinal canal from C5 to C7 level, with low signal intensity on T1 and T2 weighted images and non-enhancement on T1 weighted-enhanced images. We decided to undertake surgical exploration. At the operation field, there was yellow colored, thickened fibrous tissue over the dura mater. The lesion was removed totally, and decompression of spinal cord was achieved. Symptoms improved partially after the operation. Histopathologically, fibrotic pachymeninges with scanty inflammatory cells was revealed, which was compatible with diagnosis of idiopathic hypertrophic pachymeningitis. Six months after operation, motor power grade of both lower extremities was normal on physical examination. However, the patient still complained of mild weakness in the right lower extremity. Although the nature of IHSP is generally indolent, decompressive surgery should be considered for the patient with definite or progressive neurologic symptoms in order to prevent further deterioration. In addition, IHSP can present as an osteolytic lesion. Differential diagnosis with neoplastic disease, including giant cell tumor, is important. PMID:25328657

  19. A new era in clinical genetic testing for hypertrophic cardiomyopathy.

    PubMed

    Wheeler, Matthew; Pavlovic, Aleksandra; DeGoma, Emil; Salisbury, Heidi; Brown, Colleen; Ashley, Euan A

    2009-12-01

    Building on seminal studies of the last 20 years, genetic testing for hypertrophic cardiomyopathy (HCM) has become a clinical reality in the form of targeted exonic sequencing of known disease-causing genes. This has been driven primarily by the decreasing cost of sequencing, but the high profile of genome-wide association studies, the launch of direct-to-consumer genetic testing, and new legislative protection have also played important roles. In the clinical management of hypertrophic cardiomyopathy, genetic testing is primarily used for family screening. An increasing role is recognized, however, in diagnostic settings: in the differential diagnosis of HCM; in the differentiation of HCM from hypertensive or athlete's heart; and more rarely in preimplantation genetic diagnosis. Aside from diagnostic clarification and family screening, use of the genetic test for guiding therapy remains controversial, with data currently too limited to derive a reliable mutation risk prediction from within the phenotypic noise of different modifying genomes. Meanwhile, the power of genetic testing derives from the confidence with which a mutation can be called present or absent in a given individual. This confidence contrasts with our more limited ability to judge the significance of mutations for which co-segregation has not been demonstrated. These variants of "unknown" significance represent the greatest challenge to the wider adoption of genetic testing in HCM. Looking forward, next-generation sequencing technologies promise to revolutionize the current approach as whole genome sequencing will soon be available for the cost of today's targeted panel. In summary, our future will be characterized not by lack of genetic information but by our ability to effectively parse it.

  20. Coexistence of familial hypertrophic cardiomyopathy and vasospastic angina pectoris in two brothers.

    PubMed

    Suzuki, Nobuaki; Seto, Shinji; Koide, Yuji; Sato, Osami; Hirano, Hisataka; Kawano, Hiroaki; Yano, Katsusuke

    2003-09-01

    Two brothers had familial hypertrophic cardiomyopathy and vasospastic angina pectoris concurrently. Their family history showed that one of their sisters had hypertrophic cardiomyopathy and another brother died suddenly at age 52. The clinical diagnosis of hypertrophic cardiomyopathy was confirmed by an echocardiogram and left ventriculography. They had typical chest pain at rest, and a significant vasospasm of coronary arteries with chest pain and obvious ST-T changes in the electrocardiograms was provoked by intracoronary injection of acetylcholine in both patients. The administration of a calcium antagonist and nitrate was effective for ameliorating chest pain with no cardiovascular events during the follow up period of more than 3 years. Although underlying pathophysiologic abnormalities of familial hypertrophic cardiomyopathy and vasospastic angina pectoris are considered to be transmitted genetically, the genetic backgrounds of these cases remain to be clarified.

  1. Association of juvenile and adenomatous polyposis with pulmonary arteriovenous malformation and hypertrophic osteoarthropathy.

    PubMed

    Prieto, G; Polanco, I; Sarria, J; Larrauri, J; Lassaletta, L

    1990-07-01

    The juvenile form is the usual type of colonic polyp seen during childhood. However, mixed forms associating juvenile and adenomatous polyps have been reported. A syndrome including the association of generalized juvenile polyposis, pulmonary arteriovenous malformation, and hypertrophic osteoarthropathy has been described in three cases; however, this is the first report of the association of mixed juvenile and adenomatous polyposis, pulmonary arteriovenous malformation, and hypertrophic osteoarthropathy.

  2. Seismic modeling of complex stratified reservoirs

    NASA Astrophysics Data System (ADS)

    Lai, Hung-Liang

    Turbidite reservoirs in deep-water depositional systems, such as the oil fields in the offshore Gulf of Mexico and North Sea, are becoming an important exploration target in the petroleum industry. Accurate seismic reservoir characterization, however, is complicated by the heterogeneous of the sand and shale distribution and also by the lack of resolution when imaging thin channel deposits. Amplitude variation with offset (AVO) is a very important technique that is widely applied to locate hydrocarbons. Inaccurate estimates of seismic reflection amplitudes may result in misleading interpretations because of these problems in application to turbidite reservoirs. Therefore, an efficient, accurate, and robust method of modeling seismic responses for such complex reservoirs is crucial and necessary to reduce exploration risk. A fast and accurate approach generating synthetic seismograms for such reservoir models combines wavefront construction ray tracing with composite reflection coefficients in a hybrid modeling algorithm. The wavefront construction approach is a modern, fast implementation of ray tracing that I have extended to model quasi-shear wave propagation in anisotropic media. Composite reflection coefficients, which are computed using propagator matrix methods, provide the exact seismic reflection amplitude for a stratified reservoir model. This is a distinct improvement over conventional AVO analysis based on a model with only two homogeneous half spaces. I combine the two methods to compute synthetic seismograms for test models of turbidite reservoirs in the Ursa field, Gulf of Mexico, validating the new results against exact calculations using the discrete wavenumber method. The new method, however, can also be used to generate synthetic seismograms for the laterally heterogeneous, complex stratified reservoir models. The results show important frequency dependence that may be useful for exploration. Because turbidite channel systems often display complex

  3. Mercury biogeochemical cycling in a stratified estuary

    SciTech Connect

    Mason, R.P.; Fitzgerald, W.F. ); Hurley, J. ); Hanson, A.K. Jr.; Donaghay, P.L.; Sieburth, J.M. )

    1993-09-01

    Total Hg in the permanently stratified Pettaquamscutt estuary was <25 pM throughout the water column, even in highly sulfidic bottom waters. Particulate Hg was typically >40% of the total Hg. Reactive Hg (Hg[sub R]) was generally <3 pM and decreased with depth, but there is Hg[sub R] even in the anoxic bottom waters. Elemental Hg (Hg[sup 0]) was highest in the mixed layer and below the detection limit at depth. Demethylation is not an important source of Hg[sup 0] in this estuary. Dimethylmercury was not detected. Monomethylmercury (MMHg) was near the detection limit in the mixed layer and increased rapidly in the low oxygen region. Dissolved MMHg correlated with bacteriochlorophyll pigments, suggesting that the microbial community plays an important role in MMHg production in the estuary. The overall distributions of dissolved and particulate Hg species result from the interaction with Fe and Mn redox cycling, particulate scavenging and sinking, and MMHg production in the pycnocline. The estimated rate of MMHg production from Hg[sub R] in the pycnocline region is 1.7% d[sup [minus]1]. Hg[sup 0] and MMHg are formed principally in the mixed layer and in the pycnocline region, respectively. Particulate scavenging is important, and sedimentation, methylation, and Hg[sup 0] production are the principal sinks for Hg[sub R].

  4. Thermally unstable perturbations in stratified conducting atmospheres

    NASA Astrophysics Data System (ADS)

    Reale, Fabio; Serio, Salvatore; Peres, Giovanni

    1994-10-01

    We investigate the thermal stability of isobaric perturbations in a stratified isothermal background atmosphere with solar abundances, as resulting from the competition of optically thin plasma radiative cooling and of heating conducted from the surrounding atmosphere. We have analyzed the threshold line between stable and unstable perturbations, in the plane of the two important control parameters: the initial size of the perturbation and the temperature of the unperturbed medium; this line changes with the pressure of the unperturbed atmosphere. We have extended the results of linear perturbation analysis by means of numerical calculations of the evolution of spherical isobaric perturbations, using a two-dimensional hydrodynamic code including Spitzer heat conduction. We explore a wide range of the parameters appropriate to the solar and stellar upper atmospheres: the background uniform temperature is between 105 K and 107 K, the initial pressure betweeen 0.1 and 10 dyn/sq cm, and the perturbation size between 105 and 1010 cm. The numerical results are in substantial agreement with the linear analysis. We discuss possible implications of our results also in terms of observable effects, especially concerning plasma downflows, and propose thermal instability as a possible candidate to explain the observed redshifts in solar and stellar transition region lines.

  5. Acoustic propagation under tidally driven, stratified flow.

    PubMed

    Finette, Steven; Oba, Roger; Shen, Colin; Evans, Thomas

    2007-05-01

    Amplitude and phase variability in acoustic fields are simulated within a canonical shelf-break ocean environment using sound speed distributions computed from hydrodynamics. The submesoscale description of the space and time varying environment is physically consistent with tidal forcing of stratified flows over variable bathymetry and includes the generation, evolution and propagation of internal tides and solibores. For selected time periods, two-dimensional acoustic transmission examples are presented for which signal gain degradation is computed between 200 and 500 Hz on vertical arrays positioned both on the shelf and beyond the shelf break. Decorrelation of the field is dominated by the phase contribution and occurs over 2-3 min, with significant recorrelation often noted for selected frequency subbands. Detection range is also determined in this frequency band. Azimuth-time variations in the acoustic field are illustrated for 100 Hz sources by extending the acoustic simulations to three spatial dimensions. The azimuthal and temporal structure of both the depth-averaged transmission loss and temporal correlation of the acoustic fields under different environmental conditions are considered. Depth-averaged transmission loss varies up to 4 dB, depending on a combination of source depth, location relative to the slope and tidally induced volumetric changes in the sound speed distribution. PMID:17550157

  6. Aligning the Economic Value of Companion Diagnostics and Stratified Medicines

    PubMed Central

    Blair, Edward D.; Stratton, Elyse K.; Kaufmann, Martina

    2012-01-01

    The twin forces of payors seeking fair pricing and the rising costs of developing new medicines has driven a closer relationship between pharmaceutical companies and diagnostics companies, because stratified medicines, guided by companion diagnostics, offer better commercial, as well as clinical, outcomes. Stratified medicines have created clinical success and provided rapid product approvals, particularly in oncology, and indeed have changed the dynamic between drug and diagnostic developers. The commercial payback for such partnerships offered by stratified medicines has been less well articulated, but this has shifted as the benefits in risk management, pricing and value creation for all stakeholders become clearer. In this larger healthcare setting, stratified medicine provides both physicians and patients with greater insight on the disease and provides rationale for providers to understand cost-effectiveness of treatment. This article considers how the economic value of stratified medicine relationships can be recognized and translated into better outcomes for all healthcare stakeholders. PMID:25562363

  7. Lake Constance

    Atmospheric Science Data Center

    2013-04-17

    article title:  Lake Constance, Europe     View ... This Multi-angle Imaging SpectroRadiometer (MISR) image of Lake Constance covers an area measuring 355 kilometers x 287 kilometers, and ... wastewater and fertilizers. This leads to overproduction of algae and aquatic plants, exhaustion of available oxygen, loss of some fish ...

  8. Endostatin inhibits hypertrophic scarring in a rabbit ear model*

    PubMed Central

    Ren, Hai-tao; Hu, Hang; Li, Yuan; Jiang, Hong-fei; Hu, Xin-lei; Han, Chun-mao

    2013-01-01

    Objective: The present study was designed to use an in vivo rabbit ear scar model to investigate the efficacy of systemic administration of endostatin in inhibiting scar formation. Methods: Eight male New Zealand white rabbits were randomly assigned to two groups. Scar model was established by making six full skin defect wounds in each ear. For the intervention group, intraperitoneal injection of endostatin was performed each day after the wound healed (about 15 d post wounding). For the control group, equal volume of saline was injected. Thickness of scars in each group was measured by sliding caliper and the scar microcirculatory perfusion was assessed by laser Doppler flowmetry on Days 15, 21, 28, and 35 post wounding. Rabbits were euthanatized and their scars were harvested for histological and proteomic analyses on Day 35 post wounding. Results: Macroscopically, scars of the control group were thicker than those of the intervention group. Significant differences between the two groups were observed on Days 21 and 35 (p<0.05). Scar thickness, measured by scar elevation index (SEI) at Day 35 post wounding, was significantly reduced in the intervention group (1.09±0.19) compared with the controls (1.36±0.28). Microvessel density (MVD) observed in the intervention group (1.73±0.94) was significantly lower than that of the control group (5.63±1.78) on Day 35. The distribution of collagen fibers in scars treated with endostatin was relatively regular, while collagen fibers in untreated controls were thicker and showed disordered alignment. Western blot analysis showed that the expressions of type I collagen and Bcl-2 were depressed by injection of endostatin. Conclusions: Our results from the rabbit ear hypertrophic scar model indicate that systemic application of endostatin could inhibit local hypertrophic scar formation, possibly through reducing scar vascularization and angiogenesis. Our results indicated that endostatin may promote the apoptosis of

  9. Magnetic flux concentrations from turbulent stratified convection

    NASA Astrophysics Data System (ADS)

    Käpylä, P. J.; Brandenburg, A.; Kleeorin, N.; Käpylä, M. J.; Rogachevskii, I.

    2016-04-01

    Context. The formation of magnetic flux concentrations within the solar convection zone leading to sunspot formation is unexplained. Aims: We study the self-organization of initially uniform sub-equipartition magnetic fields by highly stratified turbulent convection. Methods: We perform simulations of magnetoconvection in Cartesian domains representing the uppermost 8.5-24 Mm of the solar convection zone with the horizontal size of the domain varying between 34 and 96 Mm. The density contrast in the 24 Mm deep models is more than 3 × 103 or eight density scale heights, corresponding to a little over 12 pressure scale heights. We impose either a vertical or a horizontal uniform magnetic field in a convection-driven turbulent flow in set-ups where no small-scale dynamos are present. In the most highly stratified cases we employ the reduced sound speed method to relax the time step constraint arising from the high sound speed in the deep layers. We model radiation via the diffusion approximation and neglect detailed radiative transfer in order to concentrate on purely magnetohydrodynamic effects. Results: We find that super-equipartition magnetic flux concentrations are formed near the surface in cases with moderate and high density stratification, corresponding to domain depths of 12.5 and 24 Mm. The size of the concentrations increases as the box size increases and the largest structures (20 Mm horizontally near the surface) are obtained in the models that are 24 Mm deep. The field strength in the concentrations is in the range of 3-5 kG, almost independent of the magnitude of the imposed field. The amplitude of the concentrations grows approximately linearly in time. The effective magnetic pressure measured in the simulations is positive near the surface and negative in the bulk of the convection zone. Its derivative with respect to the mean magnetic field, however, is positive in most of the domain, which is unfavourable for the operation of the negative

  10. STRATIFIED COMPOSITION EFFECTS ON PLANETARY NEUTRON FLUX

    SciTech Connect

    O. GASNAULT; ET AL

    2001-01-01

    All the bodies of the solar system that are directly irradiated by the galactic cosmic rays, emit enough neutrons to allow a measurement from space. These leakage neutron fluxes are indexes of the surface composition, depending on the energy of the neutrons [1]. Recent work propose geochemical interpretations of these fluxes: the thermal energy range is sensitive to iron, titanium, rare earth elements and thorium [2, 3], the epithermal energy range is sensitive to hydrogen, samarium and gadolinium [2] and the fast energy range is representative of the average soil atomic mass [4]. Nevertheless these studies make the hypothesis of a composition uniform within the footprint of the spectrometer and independent of depth. We show in this abstract that a stratified composition could change significantly the flux intensity and complicate the interpretation of the measurements. The neutron leakage flux is a competition between production effects (sensitive at high energy) and diffusion-capture effects (mostly sensitive at low energy). On one hand, it happens to be that the elements which produce the higher number of neutrons in typical lunar compositions are iron and titanium, which have also large cross section of absorption with the neutrons. On the other hand, the maximum of neutron intensity does not occur at the surface but at about 180 g cm{sup {minus}2} in depth. Therefore, if we have an iron- and/or titanium-rich soil (important production of neutrons) with a top layer having less iron and/or titanium (i.e. more transparent to the neutrons), we can expect an enhancement of the flux compared to a uniform composition.

  11. Involvement of impaired desmosome-related proteins in hypertrophic scar intraepidermal blister formation.

    PubMed

    Tan, Jianglin; He, Weifeng; Luo, Gaoxing; Wu, Jun

    2015-11-01

    Hypertrophic scar is one of the unique fibrotic diseases in human. Intraepidermal blister is a common clinical symptom following the hypertrophic scar formation. However, little is known about the reason of blister creation. In this study, we selected three patients with hypertrophic scar as manifested by raised, erythematous, pruritic, blister and thickened appearance undergoing scar resection. The first scar sample was 6 months after burn from the neck of a 3 years old male patient with 10 score by Vancouver Scar Scale (VSS). The second scar sample was 12 months after burn from the dorsal foot of a 16 years old female patient with 13 score by VSS. The third one was 9 months after burn from the elbow of a 34 years old male patients with 13 score by VSS. In order to understand the molecular mechanism of blister formation, we screened the different protein expression between hypertrophic scar and normal skin tissue by means of isobaric tags for relative and absolute quantitation (iTRAQ) labeling technology and high throughput 2D LC-MS/MS. There were 48 proteins found to be downregulated in hypertrophic scar. Among the downregulated ones, plakophilin1 (PKP1), plakophilin3 (PKP3) and desmoplakin (DSP) were the desmosome-related proteins which were validated by immunohistochemistry and western blotting assay. Transmission electron microscopy further showed the considerably reduced size and intensity of hemidesmosome and desmosome in hypertrophic scar tissue, compared to control normal skin. Our data indicted for the first time that downregulation of DSP, PKP1 and PKP3 in hypertrophic scar might be responsible for intraepidermal blister formation.

  12. Propofol improves recovery of the isolated working hypertrophic heart from ischaemia-reperfusion.

    PubMed

    King, Nicola; Al Shaama, Madj; Suleiman, M-Saadeh

    2012-11-01

    The general anaesthetic propofol shows promise in protecting normal hearts against various cardiac insults, but little is known about its cardioprotective potential in hypertrophic hearts. This study tested the hypothesis that propofol at a clinically relevant dose would enhance functional recovery in hypertrophic hearts following ischaemia. Hypertrophic hearts from spontaneously hypertensive rats and hearts from their normotensive controls, Wistar Kyoto Rats, were equilibrated in the working mode prior to global normothermic ischaemia. Reperfusion commenced with 10 min in Langendorff mode, followed by 30-min working reperfusion. Functional performance was measured throughout the working mode, whilst reperfusion damage was assessed from myocardial troponin I release during Langendorff reperfusion. Where used, 4 μg/ml propofol was added 10 min before ischaemia and was washed out 10 min into working reperfusion. An additional protocol investigated recovery of hearts protected by normothermic hyperkalaemic cardioplegic arrest. Following 20-min ischaemia, reperfusion damage was significantly worse in hypertrophic hearts compared to normal hearts, whilst addition of propofol to hypertrophic hearts significantly improved the aortic flow (31 ± 5.8 vs. 11.6 ± 2.0 ml/min, n = 6-7 ± SE, p < 0.05). Propofol also conferred significant protection following 30-min ischaemia where the recovery of cardiac output and stroke volume was similar to that for cardioplegia alone. Incubation with propofol improved the NADH/NAD(+) ratio in freshly isolated cardiomyocytes from hypertrophic hearts, suggesting possible improvements in metabolic flux. These findings suggest that propofol at the clinically relevant dose of 4 μg/ml is as effective as cardioplegic arrest in protecting hypertrophic hearts against ischaemia-reperfusion.

  13. Lake Superior Phytoplankton Characterization from the 2006 Probability Based Survey

    EPA Science Inventory

    We conducted a late summer probability based survey of Lake Superior in 2006 which consisted of 52 sites stratified across 3 depth zones. As part of this effort, we collected composite phytoplankton samples from the epilimnion and the fluorescence maxima (Fmax) at 29 of the site...

  14. Pharmacological treatment of hypertrophic cardiomyopathy: current practice and novel perspectives.

    PubMed

    Ammirati, Enrico; Contri, Rachele; Coppini, Raffaele; Cecchi, Franco; Frigerio, Maria; Olivotto, Iacopo

    2016-09-01

    Hypertrophic cardiomyopathy (HCM) is entering a phase of intense translational research that holds promise for major advances in disease-specific pharmacological therapy. For over 50 years, however, HCM has largely remained an orphan disease, and patients are still treated with old drugs developed for other conditions. While judicious use of the available armamentarium may control the clinical manifestations of HCM in most patients, specific experience is required in challenging situations, including deciding when not to treat. The present review revisits the time-honoured therapies available for HCM, in a practical perspective reflecting real-world scenarios. Specific agents are presented with doses, titration strategies, pros and cons. Peculiar HCM dilemmas such as treatment of dynamic outflow obstruction, heart failure caused by end-stage progression and prevention of atrial fibrillation and ventricular arrhythmias are assessed. In the near future, the field of HCM drug therapy will rapidly expand, based on ongoing efforts. Approaches such as myocardial metabolic modulation, late sodium current inhibition and allosteric myosin inhibition have moved from pre-clinical to clinical research, and reflect a surge of scientific as well as economic interest by academia and industry alike. These exciting developments, and their implications for future research, are discussed. PMID:27109894

  15. Idiopathic hypertrophic pachymeningitis mimicking prolactinoma with recurrent vision loss.

    PubMed

    Lok, Julie Y C; Yip, Nelson K F; Chong, Kelvin K L; Li, C L; Young, Alvin L

    2015-08-01

    Idiopathic hypertrophic pachymeningitis is a rare inflammatory condition with diffuse thickening of the dura mater, which may cause a compressive effect or vascular compromise. We report on a 28-year-old Chinese woman with a history of granulomatous mastitis 7 years previously and oligomenorrhoea, headache, blurred vision, and raised prolactin level 2 years previously, that was diagnosed as prolactinoma and treated conservatively with bromocriptine. However, she had recurrent bilateral vision loss when the bromocriptine was stopped. Her symptoms were resolved by high-dose steroid injection but remained steroid-dependent. Serial magnetic resonance imaging scan showed progressive diffuse thickening of the pachymeningitis with disappearance of pituitary apoplexy. Lumbar puncture showed lymphocytosis with no organisms. Open biopsy of the meninges was performed and histology showed features of inflammatory infiltrates and vasculitis. This is an unusual presentation of a rare condition in this age-group, with co-existing granulomatous mastitis and chronic otitis media, and is a diagnostic challenge mimicking pituitary macroadenoma and meningioma in initial magnetic resonance imaging scans.

  16. Diastolic filling in a physical model of obstructive hypertrophic cardiomyopathy

    NASA Astrophysics Data System (ADS)

    Schovanec, Joseph; Samaee, Milad; Lai, Hong Kuan; Santhanakrishnan, Arvind

    2015-11-01

    Hypertrophic Cardiomyopathy (HCM) is an inherited heart disease that affects as much as one in 500 individuals, and is the most common cause of sudden death in young athletes. The myocardium becomes abnormally thick in HCM and deforms the internal geometry of the left ventricle (LV). Previous studies have shown that a vortex is formed during diastolic filling, and further that the dilated LV morphology seen in systolic heart failure results in altering the filling vortex from elliptical to spherical shape. We have also previously shown that increasing LV wall stiffness decreases the filling vortex circulation. However, alterations to intraventricular filling fluid dynamics due to an obstructive LV morphology and locally elevated wall stiffness (in the hypertrophied region) have not been previously examined from a mechanistic standpoint. We conducted an experimental study using an idealized HCM physical model and compared the intraventricular flow fields obtained from 2D PIV to a baseline LV physical model with lower wall stiffness and anatomical geometry. The obstruction in the HCM model leads to earlier breakdown of the filling vortex as compared to the anatomical LV. Intraventricular filling in both models under increased heart rates will be discussed.

  17. Factors Associated with Uptake of Genetics Services for Hypertrophic Cardiomyopathy.

    PubMed

    Khouzam, Amirah; Kwan, Andrea; Baxter, Samantha; Bernstein, Jonathan A

    2015-10-01

    Hypertrophic cardiomyopathy (HCM) is a common cardiovascular disorder with variable expressivity and incomplete penetrance. Clinical guidelines recommend consultation with a genetics professional as part of an initial assessment for HCM, yet there remains an underutilization of genetics services. We conducted a study to assess factors associated with this underutilization within the framework of the Health Belief Model (HBM). An online survey was completed by 306 affected individuals and at risk family members. Thirty-seven percent of individuals (113/306) had visited a genetics professional for reasons related to HCM. Genetic testing was performed on 53 % (162/306). Individuals who had undergone testing were more likely to have seen a genetics professional (p < 0.001), had relatives with an HCM diagnosis (p = 0.002), and have a known familial mutation (p < 0.001). They were also more likely to agree that genetic testing would satisfy their curiosity (p < 0.001), provide reassurance (p < 0.001), aid family members in making healthcare decisions (p < 0.001), and encourage them to engage in a healthier lifestyle (p = 0.002). The HBM components of cues to action and perceived benefits and barriers had the greatest impact on uptake of genetic testing. In order to ensure optimal counseling and care for individuals and families with HCM, awareness and education around HCM and genetic services should be promoted in both physicians and patients alike.

  18. Echocardiographic diagnosis of the different phenotypes of hypertrophic cardiomyopathy.

    PubMed

    Parato, Vito Maurizio; Antoncecchi, Valeria; Sozzi, Fabiola; Marazia, Stefania; Zito, Annapaola; Maiello, Maria; Palmiero, Pasquale

    2016-01-01

    Hypertrophic Cardiomyopathy (HCM) is an inherited cardiovascular disorder of great genetic heterogeneity and has a prevalence of 0.1 - 0.2 % in the general population. Several hundred mutations in more than 27 genes, most of which encode sarcomeric structures, are associated with the HCM phenotype. Then, HCM is an extremely heterogeneous disease and several phenotypes have been described over the years. Originally only two phenotypes were considered, a more common, obstructive type (HOCM, 70 %) and a less common, non-obstructive type (HNCM, 30 %) (Maron BJ, et al. Am J Cardiol 48:418 -28, 1981). Wigle et al. (Circ 92:1680-92, 1995) considered three types of functional phenotypes: subaortic obstruction, midventricular obstruction and cavity obliteration. A leader american working group suggested that HCM should be defined genetically and not morphologically (Maron BJ, et al. Circ 113:1807-16, 2006). The European Society of Cardiology Working Group on Myocardial and Pericardial Diseases recommended otherwise a morphological classification (Elliott P, et al. Eur Heart J 29:270-6, 2008). Echocardiography is still the principal tool for the diagnosis, prognosis and clinical management of HCM. It is well known that the echocardiographic picture may have a clinical and prognostic impact. For this reason, in this article, we summarize the state of the art regarding the echocardiographic pattern of the HCM phenotypes and its impact on clinical course and prognosis. PMID:27519172

  19. Hypertrophic Olivary Degeneration: A Neurosurgical Point of View.

    PubMed

    Carvalho, Carlos Henrique; Kimmig, Hubert; Lopez, William Omar Contreras; Lange, Manfred; Oeckler, Reinhard

    2016-01-01

    Hypertrophic olivary degeneration (HOD) is a rare form of transsynaptic degeneration characterized by hypertrophy of the inferior olivary nucleus situated in the olivary body, part of the medulla oblongata, representing a major source of input to the cerebellum. HOD typically results from focal lesions interrupting connections from the inferior olive within the dentato-rubro-olivary pathway, a region also known as the triangle of Guillain-Mollaret (TGM) (red nucleus, inferior olivary nucleus, and contralateral dentate nucleus). Clinically, HOD presents classically as palatal tremor and can include dentatorubral tremor and/or ocular myoclonus. The pathologic changes associated with HOD feature radiologic changes with the inferior olivary nucleus appearing larger and increasing its T2-weighted signal intensity on magnetic resonance images. HOD is commonly managed with pharmacotherapy but may require surgical intervention in extreme cases. HOD has been found to develop as a consequence of any injury that disrupts the TGM pathways (e.g., pontine cavernoma).These findings highlight the critical importance of a thorough knowledge of TGM anatomy to avoid secondary HOD. We present a patient who developed HOD secondary to resection of a tectal plate cavernous malformation and review the literature with an emphasis on the current knowledge of this disorder.

  20. Infantile hypertrophic pyloric stenosis in Belfast, 1957-1969.

    PubMed Central

    Dodge, J A

    1975-01-01

    Infants with hypertrophic pyloric stenosis born in Belfast during the 13 years 1957-1969 have been reviewed. Their distribution shows a bias towards higher social classes, breast feeding, and primogeniture. Obstetric factors and parental ages seem to be of no importance. More affected infants were born during winter months than would be expected. The overall incidence of infantile pyloric stenosis in this community has fallen during the period under review. Clinically, the patients started vomiting at a mean age of 22 days and it is recommended that the condition should not be called 'congenital'. The size of the tumour is mainly determined by the size of the patient, rather than by his age or duration of symptoms. Attention is drawn to the occurrence of haematemesis in 17-5% and melaena in 2-9% of infants. Jaundice occurred in 1-8% of patients in this series, and is attributed to the adverse effect of starvation on hepatic glucuronyl transferase activity. Other conditions noted in these patients included inguinal hernia, partial thoracic stomach, and phenylketonuria. Subsequent growth and development were in the anticipated range. PMID:1170811

  1. Lake trout (Salvelinus namaycush) suppression for bull trout (Salvelinus confluentus) recovery in Flathead Lake, Montana, North America

    USGS Publications Warehouse

    Hansen, Michael J.; Hansen, Barry S; Beauchamp, David A.

    2016-01-01

    Non-native lake trout Salvelinus namaycush displaced native bull trout Salvelinus confluentus in Flathead Lake, Montana, USA, after 1984, when Mysis diluviana became abundant following its introduction in upstream lakes in 1968–1976. We developed a simulation model to determine the fishing mortality rate on lake trout that would enable bull trout recovery. Model simulations indicated that suppression of adult lake trout by 75% from current abundance would reduce predation on bull trout by 90%. Current removals of lake trout through incentivized fishing contests has not been sufficient to suppress lake trout abundance estimated by mark-recapture or indexed by stratified-random gill netting. In contrast, size structure, body condition, mortality, and maturity are changing consistent with a density-dependent reduction in lake trout abundance. Population modeling indicated total fishing effort would need to increase 3-fold to reduce adult lake trout population density by 75%. We conclude that increased fishing effort would suppress lake trout population density and predation on juvenile bull trout, and thereby enable higher abundance of adult bull trout in Flathead Lake and its tributaries.

  2. Gas slug ascent through rheologically stratified conduits

    NASA Astrophysics Data System (ADS)

    Capponi, Antonio; James, Mike R.; Lane, Steve J.

    2016-04-01

    Textural and petrological evidence has indicated the presence of viscous, degassed magma layers at the top of the conduit at Stromboli. This layer acts as a plug through which gas slugs burst and it is thought to have a role in controlling the eruptive dynamics. Here, we present the results of laboratory experiments which detail the range of slug flow configurations that can develop in a rheologically stratified conduit. A gas slug can burst (1) after being fully accommodated within the plug volume, (2) whilst its base is still in the underlying low-viscosity liquid or (3) within a low-viscosity layer dynamically emplaced above the plug during the slug ascent. We illustrate the relevance of the same flow configurations at volcanic-scale through a new experimentally-validated 1D model and 3D computational fluid dynamic simulations. Applied to Stromboli, our results show that gas volume, plug thickness, plug viscosity and conduit radius control the transition between each configuration; in contrast, the configuration distribution seems insensitive to the viscosity of magma beneath the plug, which acts mainly to deliver the slug into the plug. Each identified flow configuration encompasses a variety of processes including dynamic narrowing and widening of the conduit, generation of instabilities along the falling liquid film, transient blockages of the slug path and slug break-up. All these complexities, in turn, lead to variations in the slug overpressure, mirrored by changes in infrasonic signatures which are also associated to different eruptive styles. Acoustic amplitudes are strongly dependent on the flow configuration in which the slugs burst, with both acoustic peak amplitudes and waveform shapes reflecting different burst dynamics. When compared to infrasonic signals from Stromboli, the similarity between real signals and laboratory waveforms suggests that the burst of a slug through a plug may represent a viable first-order mechanism for the generation of

  3. Waves and vortices in rotating stratified turbulence

    NASA Astrophysics Data System (ADS)

    Pouquet, Annick; Herbert, Corentin; Marino, Raffaele; Rosenberg, Duane

    2015-04-01

    The interactions between vortices and waves is a long-standing problem in fluid turbulence. It can lead to a self-sustaining process that is dominant, for example in pipe flows, and to the prediction of large-scale coherent structures such as baroclinic jets in planetary atmospheres, and it can also be used as a control tool for the onset of turbulence. Similarly, the dynamics of the atmosphere and the ocean is dominated by complex interactions between nonlinear eddies and waves due to a combination of rotation and stratification (characterized respectively by frequencies f and N), as well as shear layers. The waves are faster at large scales, and this leads to a quasi-geostrophic quasi-linear regime in which there is a balance between pressure gradient and the Coriolis and gravity forces. The range of scales in these geophysical flows before dissipation prevails is such that other regimes can arise in which turbulence comes into play, with the eddy turn-over time becoming comparable to the wave period, and for which isotropy recovers for sufficiently high Reynolds numbers. One may decompose the flow-- observational, experimental or numerical, in terms of the normal modes that it supports, i.e. the inertia-gravity waves and the (slow, zero frequency) vortical modes carrying the potential vorticity, thanks to the existence of a small parameter, as for example the fluctuation around a mean flow or the ratio of the wave period to the eddy turn-over time. In this context an ensemble of data sets of rotating stratified turbulence will be analyzed, stemming from accurate direct numerical simulations of the Boussinesq equations at high resolution, up to 40963 grid points, using high-performance computing. These flows all support a constant-flux bi-directional cascade of energy towards both the large scales and the small scales. The parameter space includes the Reynolds number, the Prandtl number(s), and the Rossby and Froude numbers, and a universal response to a variety

  4. Using Nuclear Receptor Activity to Stratify Hepatocarcinogens

    PubMed Central

    Shah, Imran; Houck, Keith; Judson, Richard S.; Kavlock, Robert J.; Martin, Matthew T.; Reif, David M.; Wambaugh, John; Dix, David J.

    2011-01-01

    utility of in vitro assays for stratifying environmental contaminants based on a combination of human bioactivity and rodent toxicity. PMID:21339822

  5. Effect of Hematoporphyrin Monomethyl Ether-Sonodynamic Therapy (HMME-SDT) on Hypertrophic Scarring

    PubMed Central

    Liu, Youbin; Wu, Yin; Li, Hongxi; Zhao, Chengbin; Li, Huazhe; Meng, Qinggang; Li, Wei

    2014-01-01

    Objective The aim of the present study was to explore the potential for hematoporphyrin monomethyl ether-Sonodynamic Therapy (HMME-SDT) treatment of hypertrophic scars within rabbit ears. Methods 60 white rabbits were randomly divided into five groups: 1) untreated controls, 2) lesioned, 3) lesioned + HMME, 4) lesioned + US (Ultrasound), and 5) lesioned +HMME-SDT. After induction of a lesion upon the ears of the rabbits, hypertrophic scars were assessed at 14, 28, 42 and 56 days post-lesion +/− treatment. Assessments consisted of visual inspection in the change of the skin, scar formation pathological morphology by hematoxylin and eosin (HE) staining technique with optical microscopy, calculation of a hypertrophic index, fibroblastic density measures, and observation of collagen changes in the scar tissue by Van Gieson's (VG)Stain along with calculation of collagen area density. Results With continued HMME-SDT treatment there was a gradual improvement in all parameters over the duration of the experiment. The lesion-induced scars of rabbits receiving HMME-SDT treatment were soft, the size was reduced, hyperplasia was flat and the color pale. The fibroblasts and collagens were reduced and the collagens were light red, sparse and orderly. The hypertrophic index was reduced, since the fibroblastic density was lowered and collagen area density was decreased. Conclusion HMME is an effective sonosensitizer and the combination of HMME-SDT treatment can exert significant benefits in reducing the formation of hypertrophic scars. PMID:24465834

  6. Paclitaxel reduces formation of hypertrophic scars in the rabbit ear model

    PubMed Central

    Huang, Li-ping; Wang, Guo-qi; Jia, Zi-shan; Chen, Jing-wen; Wang, Gang; Wang, Xing-lin

    2015-01-01

    Background and objective The onset and progression of pathological scarring involves multiple cytokines and complex mechanisms. However, hyperplasia of fibroblasts and neovascularization plays important roles, which can be inhibited by paclitaxel. The aim of this study was to investigate the efficacy of paclitaxel in the treatment of hypertrophic scars on rabbit ears. Methods Rabbit ear models of hypertrophic scars were established to observe the therapeutic effects of paclitaxel at different concentrations (12 mg/L, 24 mg/L, 48 mg/L, 96 mg/L, 18 mg/L, 54 mg/L, 162 mg/L, 486 mg/L, 30 mg/L, 150 mg/L, 750 mg/L, 3,750 mg/L). The outcome measures included hypertrophic index (HI), density of fibroblasts, density of collagenous fibers, and microvessel density. Results In comparison with the control group, the concentrations of 96 mg/L, 150 mg/L, and 162 mg/L significantly reduce the formation of hypertrophic scars in the rabbit ear models. However, local necrosis was found in the rabbit ear models treated with paclitaxel solution >400 mg/L. Conclusion Paclitaxel has strong inhibitory effects on the hyperplasia of fibroblasts, deposition of collagen, and microangiogenesis in hypertrophic scars on rabbit ears within the concentration range from 48 mg/L to 162 mg/L, without causing local necrosis. PMID:26251604

  7. Hypertrophic phenotype in cardiac cell assemblies solely by structural cues and ensuing self-organization

    PubMed Central

    Chung, Chiung-yin; Bien, Harold; Sobie, Eric A.; Dasari, Vikram; McKinnon, David; Rosati, Barbara; Entcheva, Emilia

    2011-01-01

    In vitro models of cardiac hypertrophy focus exclusively on applying “external” dynamic signals (electrical, mechanical, and chemical) to achieve a hypertrophic state. In contrast, here we set out to demonstrate the role of “self-organized” cellular architecture and activity in reprogramming cardiac cell/tissue function toward a hypertrophic phenotype. We report that in neonatal rat cardiomyocyte culture, subtle out-of-plane microtopographic cues alter cell attachment, increase biomechanical stresses, and induce not only structural remodeling, but also yield essential molecular and electrophysiological signatures of hypertrophy. Increased cell size and cell binucleation, molecular up-regulation of released atrial natriuretic peptide, altered expression of classic hypertrophy markers, ion channel remodeling, and corresponding changes in electrophysiological function indicate a state of hypertrophy on par with other in vitro and in vivo models. Clinically used antihypertrophic pharmacological treatments partially reversed hypertrophic behavior in this in vitro model. Partial least-squares regression analysis, combining gene expression and functional data, yielded clear separation of phenotypes (control: cells grown on flat surfaces; hypertrophic: cells grown on quasi-3-dimensional surfaces and treated). In summary, structural surface features can guide cardiac cell attachment, and the subsequent syncytial behavior can facilitate trophic signals, unexpectedly on par with externally applied mechanical, electrical, and chemical stimulation.—Chung, C., Bien, H., Sobie, E. A., Dasari, V., McKinnon, D., Rosati, B., Entcheva, E. Hypertrophic phenotype in cardiac cell assemblies solely by structural cues and ensuing self-organization. PMID:21084696

  8. The treatment of keloids and hypertrophic scars with intralesional bleomycin in skin of color.

    PubMed

    Payapvipapong, Kittisak; Niumpradit, Nucha; Piriyanand, Chotinand; Buranaphalin, Sawanya; Nakakes, Artit

    2015-03-01

    Intralesional injection with corticosteroid remains the mainstay of therapy for hypertrophic scars and keloids, however some lesions are unresponsive or may result in skin atrophy. Intralesional bleomycin injection is an alternative therapy that has been widely reported. In order to compare the effectiveness and safety of bleomycin for the treatment of keloids and hypertrophic scars in skin of color population, Fitzpatrick skin type III to V patients with keloids or hypertrophic scars were randomized into two groups. Group A was treated monthly with intralesional triamcinolone acetonide (10 mg/mL), while group B with intralesional bleomycin (1 mg/mL) for three consecutive months. Evaluation of the treatment was performed using "Patient and Observer Scar Assessment Scale" (POSAS), self-rated patient satisfaction score, photography, and ultrasonography. Two patients had their bleomycin blood levels monitored. Twenty-six patients with keloids or hypertrophic scars were recruited. The clinical improvement as assessed by the POSAS was not statistically significant. In terms of patients satisfaction score, one half of both groups reported a very good improvement. Photographic as well as ultrasonographic evaluation showed no difference between the two groups. Bleomycin was found to enter the blood circulation in a very small amount. The major side effect was hyperpigmentation. There was no skin atrophy detected in this study. Intralesional bleomycin is a safe and effective treatment for keloids and hypertrophic scars. The treatment is comparable to intralesional triamcinolone. Unfortunately, hyperpigmentation was the major side effect in darker skin type.

  9. Morphologic stages of the terminal hypertrophic chondrocyte of growth plate cartilage.

    PubMed

    Farnum, C E; Wilsman, N J

    1987-11-01

    Recent biochemical and morphologic evidence supports the concept that hypertrophic chondrocytes of growth plate cartilage are fully viable cells that play a major functional role in controlling endochondral ossification. However, events associated with chondrocyte death remain unknown. In this study we assess the viability of terminal hypertrophic chondrocytes in situ in an organ culture system viewed simultaneously with rectified Nomarski interference contrast optics and with vital staining under fluorescence optics. Second, we use two methods of optimal chemical fixation at the ultrastructural level to define morphologically distinct stages of the terminal hypertrophic chondrocyte, which we interpret as the stages preceding chondrocyte death. An analysis of serial sections at the light microscope level showed that terminal chondrocytes were found, with different probabilities, in three morphologically distinguishable stages. Seventy-five percent of all profiles were fully hydrated cells with an intact plasma membrane making direct contact with the pericellular matrix, a morphology identical to that of living terminal chondrocytes viewed in Nomarski optics. Approximately 1% of terminal chondrocytes, while still in a fully hydrated state, consistently made a direct asymmetrical contact of the plasma membrane with the last transverse septum. In 24% of the profiles, terminal chondrocytes were found as condensed cells that retained their attachment to the last transverse septum. The stages were not characteristic of chondrocytes positioned more proximally in the growth plate. We hypothesize that a condensed morphology eventually characterizes each hypertrophic chondrocyte, and we relate these observations to current hypotheses concerning the mechanism of death of hypertrophic chondrocytes. PMID:3425941

  10. Relationship between p53 gene codon-72 polymorphisms and hypertrophic scar formation following caesarean section.

    PubMed

    Gao, Jianhua; Chen, Ying; Liao, Nong; Zhao, Wei; Zeng, Weisen; Li, Yingtao; Wang, Shaojing; Lu, Feng

    2014-05-01

    The aim of the present study was to determine the relationship between p53 gene codon-72 polymorphisms and hypertrophic scar formation following caesarean section (CS). Blood samples from 260 female patients were collected one week following a CS for the detection of p53 gene polymorphisms using a molecular beacon-coupled quantitative polymerase chain reaction technique. Patients had follow-ups for 12-18 months to observe the scar formation. From these observations, the relationship between the p53 codon-72 polymorphisms and hypertrophic scar formation occurrence was investigated. Among the patients with the CCC/CCC genotype, nine patients had hypertrophic scars and 46 patients showed normal healing, which is a ratio of 0.19. However, the follow-up investigations indicated that the presence of a homozygous or heterozygous C-to-G alteration at the codon-72 site in gene p53 resulted in 13 patients with hypertrophic scars and 192 patients with normal healing, which is a ratio of 0.07. Therefore, these results indicate that patients with the CCC/CCC genotype had a higher risk of developing hypertrophic scars compared with that for patients with the CCC/CGC or CGC/CGC genotypes.

  11. Delineating recharge areas for stratified-drift aquifers in Connecticut with geologic and topographic maps

    USGS Publications Warehouse

    Handman, E.H.

    1986-01-01

    Stratified-drift aquifers, the major source of large quantities of groundwater in Connecticut, are recharged principally by (1) precipitation that infiltrates the land surface overlying the aquifer and percolates downward to the saturated zone, (2) subsurface inflow of groundwater from adjacent till-and-bedrock uplands, and (3) surface water that infiltrates through streambed or lake-bottom sediments. Infiltration of surface water commonly occurs where pumping wells lower then water table sufficiently to reverse the normal hydraulic gradient between the aquifer and nearly surface-water body to which it is hydraulically connected. In most parts of Connecticut, groundwater circulation in unconsolidated deposits is probably confined within each basin drained by a major perrennial stream. Where this is the case, surface water and groundwater drainage divides commonly coincide, and areas that contribute recharge under natural conditions and under conditions of development can be estimated using geologic and topographic maps. Large stratified-drift aquifers that extend across surface water drainage, divides underlie most of north-central Connecticut and parts of the Quinnipiac and Farmington River basins. Definition of recharge areas for these aquifers is more complicated and requires more detailed hydrologic information. (USGS)

  12. Staphylococcus hominis native mitral valve bacterial endocarditis (SBE) in a patient with hypertrophic obstructive cardiomyopathy.

    PubMed

    Cunha, Burke A; Esrick, Michael D; Larusso, Melissa

    2007-01-01

    There are several species of coagulase-negative Staphylococci (CoNS) that are part of the normal skin flora and are relatively noninvasive/low virulence organisms. CoNS are important pathogens in patients with prosthetic devices and are the most common pathogen associated with prosthetic valve endocarditis. CoNS native valve infective endocarditis (IE) is rare. Patients with hypertrophic obstructive cardiomyopathy and an outflow pressure gradient greater than 30 mm Hg are predisposed to IE. There has been only one reported case of non-mitral valve IE due to CoNS in a patient with hypertrophic obstructive cardiomyopathy. To the best of our knowledge, we report the first case of Staphylococcal hominis mitral valve endocarditis in a patient with hypertrophic obstructive cardiomyopathy.

  13. Tenosynovitis of the peroneal tendons associated with a hypertrophic peroneal tubercle: radiography and MRI findings

    PubMed Central

    Celikyay, Fatih; Yuksekkaya, Ruken; Almus, Ferdag; Bilgic, Erkal

    2014-01-01

    An enlarged peroneal tubercle can cause a peroneal tendon tear and/or tenosynovitis due to chronic friction. We present the case of a 45-year-old man with tenosynovitis in the peroneus longus and brevis tendons associated with a hypertrophic peroneal tubercle. On admission to our facility, the patient presented with pain while walking and had a fixed mass on the lateral aspect of his right foot. In addition, an osseous prominence corresponding to a hypertrophic peroneal tubercle was seen on the lateral side of the right calcaneus on radiography. MRI confirmed the hypertrophic peroneal tubercle and revealed high-signal intensity within the peroneus longus and brevis tendons along with fluid in their sheaths. PMID:24748135

  14. Hypertrophy of the feet and ankles presenting in primary hypertrophic osteoarthropathy or pachydermoperiostosis: a case report

    PubMed Central

    2012-01-01

    Introduction Pachydermoperiostosis or primary hypertrophic osteoathropathy is a rare genetic disease with autosomal transmission. This disorder, which affects both bones and skin, is characterized by the association of dermatologic changes (pachydermia or thickening of the skin) and rheumatologic manifestations (periostosis and finger clubbing). Here, we report a new observation of pachydermoperiostosis. Case presentation A 20-year-old North African Tunisian Caucasian man presented with hypertrophic osteoarthropathy. On a clinical examination, we found morphologic abnormalities of his face and extremities associated with skin changes. The laboratory findings were normal. A work-up disclosed no organic etiology. The final diagnosis consisted of pachydermoperiostosis syndrome. Conclusion Pachydermoperiostosis is a rare entity that should be differentiated from secondary hypertrophic osteoarthropathy and chronic rheumatic diseases. PMID:22273836

  15. Successful management of hypertrophic cardiomyopathy in a Matschie's tree kangaroo (Dendrolagus matschiei).

    PubMed

    Fredholm, Daniel V; Jones, Ashley E; Hall, Natalie H; Russell, Kathleen; Heard, Darryl J

    2015-03-01

    A 3-yr-old, intact male Matschie's tree kangaroo (Dendrolagus matschiei) was examined for a 1-wk history of intermittent lethargy and tachypnea. An echocardiogram revealed concentric hypertrophy of the left ventricular free wall and interventricular septum. These findings were compared to measurements from healthy Matschie's tree kangaroos, supporting a diagnosis of hypertrophic cardiomyopathy. At the time of publication, the patient has been managed for over 11.5 yr, using a combination of enalapril, furosemide, diltiazem, and diet modifications. Hypertrophic cardiomyopathy should be considered as a differential diagnosis in tree kangaroos exhibiting signs of cardiovascular or respiratory distress. This case represents the first report of antemortem diagnosis and successful management of hypertrophic cardiomyopathy in a Matschie's tree kangaroo.

  16. 3-D Eutrophication Modeling for Lake Simcoe, Canada

    NASA Astrophysics Data System (ADS)

    Lu, Q.; Duckett, F.; Nairn, R.; Brunton, A.

    2006-12-01

    The Lake Simcoe Region Conservation Authority (LSRCA) and the Province of Ontario are undertaking a series of studies to facilitate management of the pressures of population growth in the Lake Simcoe watershed. With rapid population growth and urban development comes additional land clearing, storm water runoff and the discharge of treated sewage, all of which are sources of increased phosphorus loading to Lake Simcoe. Depressed oxygen levels were linked to phosphorous enrichment of the lake, with the resultant stimulation of algal growth in the sunlit upper waters of the lake, and its subsequent senescence and settling into the hypolimnion where bacterial decomposition consumes oxygen from the stratified waters. This poster describes a 3-D hydrodynamic, thermal and water quality model of Lake Simcoe developed using the Danish Hydraulics Institute (DHI) MIKE3 model. The hydrodynamic module includes wind-driven circulation, temperature variation, development of the thermocline and thermal stratification, and hydraulic forcing from inflowing tributaries. This is linked to the water quality module which simulates the eutrophication processes in the response of the lake to loadings of phosphorus, such as algal growth, the growth of aquatic plants and subsequent oxygen consumption. The model has been calibrated against Acoustic Doppler Current Profiler velocity data, plus measured temperature and water quality data at MOE stations in the lake and water intakes. The model is an important assessment tool for the management of the lake and its watersheds, allowing assessment of the impacts of the urban growth and land use change on the water quality in Lake Simcoe.

  17. Radiofrequency catheter septal ablation for hypertrophic obstructive cardiomyopathy in children

    PubMed Central

    Emmel, M.; Sreeram, N.

    2005-01-01

    Background The definitive therapeutic options for symptomatic obstructive cardiomyopathy in childhood are restricted. At present, extensive surgical myectomy is the only procedure that is of proven benefit. Patients and Methods Three patients, aged 5, 11 and 17 years, respectively, with progressive hypertrophic obstructive cardiomyopathy and increasing symptoms were considered for radiofrequency catheter septal ablation. The peak Doppler gradient recorded on several occasions ranged between 50 to 90mmHg. Via a femoral arterial approach, the His bundle was initially plotted and marked using the LocaLisa navigation system. Subsequently, using a cooled tip catheter a series of lesions were placed in the hypertrophied septum, taking care to stay away from the His bundle. A total of 17, 50 and 45 lesions were applied in the three patients. In one case, the procedure was complicated by two episodes of ventricular fibrillation requiring DC cardioversion but without any neurological sequelae. Results The preablation peak-to-peak gradient between left ventricle and aorta was 50 mmHg, 60 mmHg and 60 mmHg, respectively, and remained unchanged immediately after the procedure. All patients were discharged from hospital 48 hours later. Serial measurement of serum troponin T and CK-MB isoenzyme confirmed significant myocardial necrosis. Follow-up echocardiography both at seven days and at six weeks postablation confirmed a beneficial haemodynamic result, with reduction of left ventricular outflow obstruction and relief of symptoms. Conclusion In young children, in whom alcohol-induced septal ablation is not an option, radiofrequency catheter ablation offers an alternative to surgery, with the benefits of repeatability and a lower risk of procedure-related permanent AV block. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:25696442

  18. Altered patterns of cardiac intercellular junction distribution in hypertrophic cardiomyopathy.

    PubMed Central

    Sepp, R.; Severs, N. J.; Gourdie, R. G.

    1996-01-01

    OBJECTIVE: To examine the distribution pattern of intercellular junctions (the mechanically coupling desmosomes and the electrically coupling gap junctions) in hypertrophic cardiomyopathy (HCM) hearts showing myofibre disarray. DESIGN: Samples from six necropsied hearts were studied, representing the interventricular septum and the free walls of the left and right ventricles. Immunohistochemical labelling of desmoplakin was used as a marker for desmosomes, and of connexin43 as a marker for gap junctions, in single and double stainings. The slides were examined by confocal laser scanning microscopy. RESULTS: Marked disorganisation of intercalated discs was observed in areas featuring myofibre disarray. Besides overall derangement, localised abnormalities in desmosome organisation were evident, which included: (1) the formation of abnormally enlarged megadiscs; (2) the presence of intersecting disc structures; and (3) aberrant side to side desmosomal connections. Gap junctional abnormalities included: (1) random distribution of gap junctions over the surface of myocytes, rather than localisation to intercalated discs; (2) abundant side to side gap junction connections between adjacent myocytes; and (3) formation of abnormally shaped gap junctions. Circles of myocytes continuously interconnected by gap junctions were also observed. Regions of the diseased hearts lacking myofibre disarray, and control hearts of normal patients and patients with other cardiac diseases, did not show these alterations. CONCLUSIONS: The disorganisation of the intercellular junctions associated with myofibre disarray in HCM may play an important role in the pathophysiological manifestations of the disease. The remodelling of gap junction distribution may underlie the formation of an arrhythmogenic substrate, thereby contributing to the generation and maintenance of cardiac arrhythmias associated with HCM. Images PMID:8944586

  19. A Murine Hypertrophic Cardiomyopathy Model: The DBA/2J Strain.

    PubMed

    Zhao, Wenyuan; Zhao, Tieqiang; Chen, Yuanjian; Zhao, Fengbo; Gu, Qingqing; Williams, Robert W; Bhattacharya, Syamal K; Lu, Lu; Sun, Yao

    2015-01-01

    Familial hypertrophic cardiomyopathy (HCM) is attributed to mutations in genes that encode for the sarcomere proteins, especially Mybpc3 and Myh7. Genotype-phenotype correlation studies show significant variability in HCM phenotypes among affected individuals with identical causal mutations. Morphological changes and clinical expression of HCM are the result of interactions with modifier genes. With the exceptions of angiotensin converting enzyme, these modifiers have not been identified. Although mouse models have been used to investigate the genetics of many complex diseases, natural murine models for HCM are still lacking. In this study we show that the DBA/2J (D2) strain of mouse has sequence variants in Mybpc3 and Myh7, relative to widely used C57BL/6J (B6) reference strain and the key features of human HCM. Four-month-old of male D2 mice exhibit hallmarks of HCM including increased heart weight and cardiomyocyte size relative to B6 mice, as well as elevated markers for cardiac hypertrophy including β-myosin heavy chain (MHC), atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and skeletal muscle alpha actin (α1-actin). Furthermore, cardiac interstitial fibrosis, another feature of HCM, is also evident in the D2 strain, and is accompanied by up-regulation of type I collagen and α-smooth muscle actin (SMA)-markers of fibrosis. Of great interest, blood pressure and cardiac function are within the normal range in the D2 strain, demonstrating that cardiac hypertrophy and fibrosis are not secondary to hypertension, myocardial infarction, or heart failure. Because D2 and B6 strains have been used to generate a large family of recombinant inbred strains, the BXD cohort, the D2 model can be effectively exploited for in-depth genetic analysis of HCM susceptibility and modifier screens.

  20. Smac/DIABLO regulates the apoptosis of hypertrophic scar fibroblasts.

    PubMed

    Liu, Bao-Heng; Chen, Liang; Li, Shi-Rong; Wang, Zhen-Xiang; Cheng, Wen-Guang

    2013-09-01

    In abnormal skin wound healing, hypertrophic scars (HS) are characterized by excessive fibroblast hypercellularity and an overproduction of collagen, leading to atypical extracellular matrix (ECM) remodeling. Although the exact mechanisms of HS remain unclear, decreased HS fibroblast (HSFB) apoptosis and increased proliferation are evident in the development of HS. In this study, the contribution of the second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein (IAP)-binding protein with a low isoelectric point (pI) (Smac/DIABLO), an apoptosis-promoting protein released from the mitochondria, was investigated in human normal skin and HSFB cultures. The expression of Smac/DIABLO is usually decreased in many malignant tumors compared with normal tissues. Immunohistochemical analysis of skin tissues and the western blot analyses of fibroblasts revealed that the expression of Smac/DIABLO was lower in HS tissues compared with normal skin tissues. Of note, adenovirus-mediated Smac/DIABLO overexpression in the cultured HSFBs significantly reduced cell proliferation, as detected by the cell counting kit-8, and increased caspase-3 and -9 activity, as detected by spectrofluorimetry. In addition, it increased apoptosis, as detected by fluorescence-activated cell sorting (FACS). Furthermore, we found that the silencing of Smac with siRNA in the HSFBs induced a noticeable decrease in caspase-3 and -9 activity, leading to a significant reduction in apoptosis. In addition, the mRNA expression of type I and III pro-collagen detected in the HSFBs was significantly increased following the silencing of Smac with siRNA and was inhibited following Smac/DIABLO overexpression, as shown by real-time RT-PCR. In conclusion, Smac/DIABLO decreases the proliferation and increases the apoptosis of HSFBs. To our knowledge, the data from our study suggest for the first time that Smac/DIABLO is a novel therapeutic target for HS.

  1. Angiotensin converting enzyme gene polymorphism in familial hypertrophic cardiomyopathy patients

    SciTech Connect

    Yu, B; Peric, S.; Ross, D.

    1994-09-01

    An insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme (ACE) gene is a useful predictor of human plasma ACE levels. ACE levels tend to be lowest in subjects with ACE genotype DD and intermediate in subjects with ACE genotype ID. Angiotensin II (Ang II) as a product of ACE is a cardiac growth factor and produces a marked hypertrophy of the chick myocyte in cell culture. Rat experiments also suggest that a small dose of ACE inhibitor that does not affect the afterload results in prevention or regression of cardiac hypertrophy. In order to study the relationship of ACE and the severity of hypertrophy, the ACE genotype has been determined in 28 patients with a clinical diagnosis of familial hypertrophic cardiomyopathy (FHC) and 51 normal subjects. The respective frequencies of I and D alleles were: 0.52 and 0.48 (in FHC patients) and 0.44 and 0.56 (in the normal controls). There was no significant difference in the allele frequencies between FHC and normal subjects ({chi}{sup 2}=0.023, p>0.05). The II, ID, and DD genotypes were present in 7, 15, and 6 FHC patients, respectively. The averages of maximal thickness of the interventricular septum measured by echocardiography or at autopsy were 18 {plus_minus}3, 19{plus_minus}4, and 19{plus_minus}3 mm in II, ID and DD genotypes, respectively. The ACE gene polymorphism did not correlate with the severity of left ventricular hypertrophy in FHC patients (r{sub s}=0.231, p>0.05). These results do not necessarily exclude the possible effect of Ang II on the hypertrophy since the latter may be produced through the action of chymase in the human ventricles. However, ACE gene polymorphism is not a useful predictor of the severity of myocardial hypertrophy in FHC patients.

  2. Clinical significance of giant negative T waves in hypertrophic cardiomyopathy

    SciTech Connect

    Alfonso, F.; Nihoyannopoulos, P.; Stewart, J.; Dickie, S.; Lemery, R.; McKenna, W.J. )

    1990-04-01

    To assess the clinical significance of giant negative T waves in patients with hypertrophic cardiomyopathy from Western nations, clinical, echocardiographic, radionuclide and 48 h electrocardiographic (ECG) monitoring findings were compared in 27 patients with and 56 patients without giant negative T waves. Patients with giant negative T waves were older at diagnosis (43 +/- 15 versus 32 +/- 14 years, p less than 0.005), had greater ECG voltage (SV1 + RV5 = 57 +/- 20 versus 37 +/- 18 mm, p less than 0.001) and had a more vertical frontal plane axis (38.4 +/- 34 versus 13.4 +/- 45 degrees, p less than 0.05). Left ventricular wall thickness on two-dimensional echocardiography was similar at the mitral valve level (mean 16.5 +/- 4 versus 16.6 +/- 3 cm), but was greater at the papillary muscle level (mean 20.7 +/- 5 versus 17.6 +/- 3 mm, p less than 0.01) and apex (mean 23.3 +/- 5 versus 17.3 +/- 3 mm, p less than 0.001) in patients with giant negative T waves. Fewer patients with giant negative T waves had asymmetric septal hypertrophy (12 (44%) of 27 versus 36 (64%) of 56, p = 0.08) or systolic anterior motion of the mitral valve (4 (14%) of 27 versus 25 (45%) of 56, p less than 0.01), whereas left ventricular end-diastolic (44.1 +/- 6 versus 39.6 +/- 5 mm, p = 0.01) and end-systolic dimensions (27.8 +/- 4 versus 24 +/- 6 mm, p less than 0.05) were greater in this group. Nonsustained ventricular tachycardia was seen on ECG monitoring in 21% of patients in both groups.

  3. Hypertrophic Osteoarthropathy and Follicular Thyroid Cancer: A Rare Paraneoplastic Syndrome

    PubMed Central

    Tavarelli, Martina; Sarfati, Julie; De Gennes, Christian; Haroche, Julien; Buffet, Camille; Ghander, Cécile; Simon, Jean Marc; Ménégaux, Fabrice; Leenhardt, Laurence

    2015-01-01

    Background Hypertrophic osteoarthropathy (HOA) is a rare condition characterized by bone and joint pain and digital clubbing usually associated with bronchopulmonary diseases. Primary HOA is rare and the pathogenesis remains unclear. Objectives Cases of HOA as a paraneoplastic syndrome associated with thyroid carcinoma are very rare – only 2 cases have been described in the literature. Results We present the first case of a 40-year-old patient affected by HOA associated with invasive differentiated follicular thyroid carcinoma operated in 2 stages. Both operations were followed by radioiodine ablation, and then a rapid unresectable local recurrence developed requiring cervical radiotherapy (70 Gy). A second treatment with 100 mCi of 131I confirmed it was a refractory thyroid cancer. Further surgery confirmed a poorly differentiated follicular cancer and 12 cycles of chemotherapy by gemcitabine and oxaliplatin followed. During the 8 years of follow-up, cervical recurrence was stable, but severe episodes of hemoptysis occurred requiring iterative embolization of the bronchial and tracheal arteries. Other lung diseases were excluded. Digital clubbing appeared, which was associated with arthritis, bone pain and inflammatory syndrome. X-rays and magnetic resonance imaging found periosteal apposition in the long bones; bone scintigraphy confirmed the HOA diagnosis. Other causes of arthritis were eliminated. She was treated with colchicine, corticosteroids and nonsteroidal anti-inflammatory drugs, but only the combination of methotrexate and hydroxychloroquine reduced the morphine requirements. Conclusion HOA is exceptionally associated with thyroid cancer and we raised the hypothesis of the secretion of a circulating factor in a patient with invasive and recurrent follicular thyroid cancer, refractory to radioiodine. PMID:26835431

  4. Hypertrophic lichen planus versus prurigo nodularis: a dermoscopic perspective

    PubMed Central

    Ankad, Balachandra S.; Beergouder, Savitha L.

    2016-01-01

    Background: Hypertrophic lichen planus (HLP) classically involves shin and ankles and is characterized by hyperkeratotic plaques and nodules. Prurigo nodularis (PN) is a chronic neurodermatitis that presents with intensely pruritic nodules. Histopathology of HLP and PN demonstrate epidermal hyperplasia, hypergranulosis, and compact hyperkeratosis. The dermis shows vertically arranged collagen fibers and an increased number of fibroblasts and capillaries in both conditions. Moreover, basal cell degeneration is confined to the tips of rete ridges, and band-like infiltration is conspicuously absent in HLP. Therefore, both conditions mimic each other clinically, which makes diagnosis difficult. Hence, there is a need for a diagnostic technique to differentiate both conditions. Objective: To evaluate dermoscopic patterns in HLP and PN and to study these patterns histopathologically. Materials and methods: The study was conducted at S. Nijalingappa Medical College in Bagalkot. It was an observational case series study. Ethical clearance and informed consent was obtained. A Dermlite 3 dermoscope (3Gen, San Juan Capistrano, CA, USA) attached to a Sony Cyber Shot camera DSC-W800 (Sony Electronics Inc., San Diego, California, USA) was employed. Histopathology was done to confirm the diagnosis. Results: There were 10 patients each with HLP and PN. HLP was seen in 8 males and 2 females. PN was observed in 7 females and 3 males. Dermoscopy of HLP demonstrated pearly white areas and peripheral striations (100%), gray-blue globules (60%), comedo-like openings (30%), red dots (40%), red globules (10%), brownish-black globules (30%), and yellowish structures (90%). In PN, red dots (70%), red globules (60%), and pearly white areas with peripheral striations (100%) were observed under dermoscopy. Conclusion: Both HLP and PN demonstrated specific dermoscopic patterns which can be demonstrated on histopathologic findings. The authors propose that these patterns are hallmarks of each

  5. Hydrogeologic evaluation of selected stratified-drift deposits in Connecticut

    USGS Publications Warehouse

    Grady, S.J.; Handman, E.H.

    1983-01-01

    Test borings at 28 sites and seismic-refraction profiles at 16 sites provide data on the saturated thickness and grain-size characteristics of stratified-drift deposits in five areas of Connecticut. These data, together with information on the areal extent of the deposits and their proximity to sources of induced recharge, can be used to estimate the water-yielding potential of the stratified-drift deposits. Individual wells could potentially yield moderate to possibly very large quantities of water (50 to 2000 gallons per minute) at some locations in all five areas where saturated, dominantly coarse-grained stratified drift is 40 feet thick or greater and hydraulically connected to nearby surface-water bodies. Coarse-grained stratified drift is most extensive in the Glastonbury, Haddam, and Simsbury, Connecticut areas. Saturated thickness exceeds 150 feet in parts of the Glastonbury and Haddam areas, but is less than 100 feet in most places. The best sites for developing large quantities of water are in the Glastonbury and Haddam areas where thick, saturated, coarse-grained stratified drift is hydraulically connected to the Connecticut River. Water in the stratified drift is generally of good chemical quality except for excessive iron (0.64 to 20 mg/L) and manganese (0.1 to 10 mg/L) in some samples. (USGS)

  6. Seasonal habitat selection by lake trout (Salvelinus namaycush) in a small Canadian shield lake: Constraints imposed by winter conditions

    USGS Publications Warehouse

    Blanchfield, P.J.; Tate, L.S.; Plumb, J.M.; Acolas, M.-L.; Beaty, K.G.

    2009-01-01

    The need for cold, well-oxygenated waters significantly reduces the habitat available for lake trout (Salvelinus namaycush) during stratification of small temperate lakes. We examined the spatial and pelagic distribution of lake trout over two consecutive summers and winters and tested whether winter increased habitat availability and access to littoral regions in a boreal shield lake in which pelagic prey fish are absent. In winter, lake trout had a narrowly defined pelagic distribution that was skewed to the upper 3 m of the water column and spatially situated in the central region of the lake. Individual core areas of use (50% Kernel utilization distributions) in winter were much reduced (75%) and spatially non-overlapping compared to summer areas, but activity levels were similar between seasons. Winter habitat selection is in contrast to observations from the stratified season, when lake trout were consistently located in much deeper waters (>6 m) and widely distributed throughout the lake. Winter distribution of lake trout appeared to be strongly influenced by ambient light levels; snow depth and day length accounted for up to 69% of the variation in daily median fish depth. More restricted habitat use during winter than summer was in contrast to our original prediction and illustrates that a different suite of factors influence lake trout distribution between these seasons. ?? Springer Science+Business Media B.V. 2009.

  7. Arthralgia and digital clubbing in a child: hypertrophic osteoarthropathy with inflammatory pseudotumour of the lung.

    PubMed

    Pichler, G; Eber, E; Thalhammer, G; Muntean, W; Zach, M S

    2004-01-01

    Arthralgia in childhood is an unspecific symptom. One rare cause of arthralgia is hypertrophic osteoarthropathy associated with digital clubbing. We present a child where hypertrophic osteoarthropathy led to the rare diagnosis of an inflammatory pseudotumour of the lung. In a 12-year-old girl with arthralgia and digital clubbing, a chest radiograph disclosed a large round mass in the right upper lobe, and the following chest computed tomography scan showed a large solid homogenous, round, well marginated lesion with little contrast enhancement. A lobectomy of the right upper lobe was performed, and histological examination showed an inflammatory pseudotumour. The postoperative course was without problems: arthralgia and digital clubbing disappeared.

  8. Anaesthetic management of severe hypertrophic obstructive cardiomyopathy with bronchial asthma for emergency caesarean section.

    PubMed

    Rajesh, M C; Varma, Ravi; Lima, P; Ramdas, E K

    2012-10-01

    A 39-year-old primi and a known case of hypertrophic obstructive cardiomyopathy presented for emergency lower segment caesarean section. She was also an asthmatic with a recent exacerbation. She underwent uneventful lower segment caesarean section under general anaesthesia with lumbar epidural analgesia for postoperative pain relief. Anaesthetic agents and techniques were selected to suit the haemodynamic profile of severe hypertrophic obstructive cardiomyopathy in pregnancy. The case has been reported because of successful outcome in an emergency scenario with such high intraventricular gradients and omissions in the case so that it will be of benefit to readers who may happen to land up in similar situations. PMID:23738413

  9. Identification and characterization of the novel Col10a1 regulatory mechanism during chondrocyte hypertrophic differentiation

    PubMed Central

    Gu, J; Lu, Y; Li, F; Qiao, L; Wang, Q; Li, N; Borgia, J A; Deng, Y; Lei, G; Zheng, Q

    2014-01-01

    The majority of human skeleton develops through the endochondral pathway, in which cartilage-forming chondrocytes proliferate and enlarge into hypertrophic chondrocytes that eventually undergo apoptosis and are replaced by bone. Although at a terminal differentiation stage, hypertrophic chondrocytes have been implicated as the principal engine of bone growth. Abnormal chondrocyte hypertrophy has been seen in many skeletal dysplasia and osteoarthritis. Meanwhile, as a specific marker of hypertrophic chondrocytes, the type X collagen gene (COL10A1) is also critical for endochondral bone formation, as mutation and altered COL10A1 expression are often accompanied by abnormal chondrocyte hypertrophy in many skeletal diseases. However, how the type X collagen gene is regulated during chondrocyte hypertrophy has not been fully elucidated. We have recently demonstrated that Runx2 interaction with a 150-bp mouse Col10a1 cis-enhancer is required but not sufficient for its hypertrophic chondrocyte-specific reporter expression in transgenic mice, suggesting requirement of additional Col10a1 regulators. In this study, we report in silico sequence analysis of this 150-bp enhancer and identification of its multiple binding factors, including AP1, MEF2, NFAT, Runx1 and TBX5. Using this enhancer as bait, we performed yeast one-hybrid assay and identified multiple candidate Col10a1-interacting genes, including cyclooxygenase 1 (Cox-1) and Cox-2. We have also performed mass spectrometry analysis and detected EF1-alpha, Fus, GdF7 and Runx3 as components of the specific complex formed by the cis-enhancer and nuclear extracts from hypertrophic MCT (mouse chondrocytes immortalized with large T antigen) cells that express Col10a1 abundantly. Notably, some of the candidate genes are differentially expressed in hypertrophic MCT cells and have been associated with chondrocyte hypertrophy and Runx2, an indispensible Col10a1 regulator. Intriguingly, we detected high-level Cox-2 expression in

  10. Principles of lake sedimentology

    SciTech Connect

    Janasson, L.

    1983-01-01

    This book presents a comprehensive outline on the basic sedimentological principles for lakes, and focuses on environmental aspects and matters related to lake management and control-on lake ecology rather than lake geology. This is a guide for those who plan, perform and evaluate lake sedimentological investigations. Contents abridged: Lake types and sediment types. Sedimentation in lakes and water dynamics. Lake bottom dynamics. Sediment dynamics and sediment age. Sediments in aquatic pollution control programmes. Subject index.

  11. Overview of the limnology of crater lake

    USGS Publications Warehouse

    Larson, G.L.

    1996-01-01

    Crater Lake occupies the collapsed caldera of volcanic Mount Mazama in Crater Lake National Park, Oregon. It is the deepest lake (589 m) in the United States and the 7th deepest lake in the world. The water column mixes to a depth of about 200 m in winter and spring from wind energy and cooling. The deep lake is mixed in winter and early spring each year when relatively cold water near the surface sinks and exchanges positions with water in the deep basins of the lake. The lake becomes thermally stratified in summer and early fall. The metalimnion extends to a depth of about 100 m; thus most of the water column is a cold hypolimnion. Secchi disk clarity measurements typically are in the upper-20-m range to the low-30-m range in summer and early fall. Concentrations of nutrients are low, although conductivity is relatively high owing to the inflow of hydrothermal fluids. Total chlorophyll is low in concentration, but typically maximal at a depth of 120 m during periods of thermal stratification. Primary production also is low, with the maximum levels occurring between the depth of 40 and 80 m. Phytoplankton taxa are spatially segregated from each other within the water column to a depth of 200 m in summer and early fall. The same generalization applies to the Zooplankton taxa. Water level, clarity, concentrations of total chlorophyll, primary production, and abundances of zooplankton and introduced kokanee salmon exhibit long-term fluctuations. Based primarily on a recent 10-year study of the lake, the lake is considered to be pristine, except for the consequences of fish introductions. ?? 1996 by the Northwest Scientific Association. All rights reserved.

  12. Overview of the limnology of Crater Lake

    USGS Publications Warehouse

    Larson, Gary L.

    1996-01-01

    Crater Lake occupies the collapsed caldera of volcanic Mount Mazama in Crater Lake National Park, Oregon. It is the deepest lake (589 m) in the United States and the 7th deepest lake in the world. The water column mixes to a depth of about 200 m in winter and spring from wind energy and cooling. The deep lake is mixed in winter and early spring each year when relatively cold water near the surface sinks and exchanges positions with water in the deep basins of the lake. The lake becomes thermally stratified in summer and early fall. The metalimnion extends to a depth of about 100 m; thus most of the water column is a cold hypolimnion. Secchi disk clarity measurements typically are in the upper-20-m range to the low-30-m range in summer and early fall. Concentrations of nutrients are low, although conductivity is relatively high owing to the inflow of hydrothermal fluids. Total chlorophyll is low in concentration, but typically maximal at a depth of 120 m during periods of thermal stratification. Primary production also is low, with the maximum levels occurring between the depth of 40 and 80 m. Phytoplankton taxa are spatially segregated from each other within the water column to a depth of 200 m in summer and early fall. The same generalization applies to the zooplankton taxa. Water level, clarity, concentrations of total chlorophyll, primary production, and abundances of zooplankton and introduced kokanee salmon exhibit long-term fluctuations. Based primarily on a recent 10-year study of the lake, the lake is considered to be pristine, except for the consequences of fish introductions.

  13. Lake Powell

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The white ring around Lake Powell tells the story. The surface is down 98 feet. This is critical, because Powell, Lake Mead, and other lakes along the Colorado River provide water for millions of people in five states. We are in the eighth year of a drought on the Colorado River. This year was the driest year ever reported in Southern California, and there is a severe drought in Northern California, down to less than 30-percent of snow pack. This ASTER image of part of Lake Powell was acquired in 2001. The gray area depicts the shrunken, reduced 2007 lake extent compared to the extended, larger black area in 2001.

    The image covers an area of 24 x 30 km, and is centered near 37.1 degrees north latitude, 111.3 degrees west longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  14. Geohydrology and water quality of stratified-drift aquifers in the middle Merrimack River basin, south-central New Hampshire

    USGS Publications Warehouse

    Ayotte, Joseph D.; Toppin, Kenneth W.

    1995-01-01

    The U.S. Geological Survey, in cooperation with the State of New Hampshire, Department of Environmental Services, Water Resources Division has assessed the geohydrology and water quality of stratified-drift aquifers in the middle Merrimack River basin in south-central New Hampshire. The middle Merrimack River basin drains 469 square miles; 98 square miles is underlain by stratified-drift aquifers. Saturated thickness of stratified drift within the study area is generally less than 40 feet but locally greater than 100 feet. Transmissivity of stratified-drift aquifers is generally less than 2,000 feet squared per day but locally exceeds 6, 000 feet squared per day. At present (1990), ground-water withdrawals from stratified drift for public supply are about 0.4 million gallons per day within the basin. Many of the stratified-drift aquifers within the study area are not developed to their fullest potential. The geohydrology of stratified-drift aquifers was investigated by focusing on basic aquifer properties, including aquifer boundaries; recharge, discharge, and direction of ground-water flow; saturated thickness and storage; and transmissivity. Surficial geologic mapping assisted in the determination of aquifer boundaries. Data from 757 wells and test borings were used to produce maps of water-table altitude, saturated thickness, and transmissivity of stratified drift. More than 10 miles of seismic-refraction profiling and 14 miles of seismic-reflection profiling were also used to construct the water table and saturated-thickness maps. Stratified-drift aquifers in the southern, western, and central parts of the study area are typically small and discontinuous, whereas aquifers in the eastern part along the Merrimack River valley are continuous. The Merrimack River valley aquifers formed in glacial Lakes Merrimack and Hooksett. Many other smaller discontinuous aquifers formed in small temporary ponds during deglaciation. A stratified-drift aquifer in Goffstown was

  15. Hypertrophic scars and keloids in surgery: current concepts.

    PubMed

    Song, Colin

    2014-09-01

    Hypertrophic scars and keloids remain a challenge in surgery. We appreciate that our understanding of the process at cellular and molecular level, profound as it is, when it comes to the clinical evidence much is left to be desired. Although the bench to bedside conundrum remains, the science of translational research calls for an even higher level of cooperation between the scientist and the clinician for the impetus to succeed.The clinicians alerted us to the possible theories in the pathogenesis of keloid formation, inter alia, the ischemia theory, mast cell theory, immune theory, transforming growth factor β interaction, mechanical theory, and the melanocyte stimulating hormone theory. All of the above presupposed a stimulus that would result in an uncontrolled upregulation of collagen and extracellular matrix expression in the pathogenesis of the keloid. This bedside to bench initiative, as in true science, realized more ponderables than possibilities.By the same token, research into the epidermal-mesenchymal signaling, molecular biology, genomics, and stem cell research holds much promise in the bench top arena. To assess efficacy, many scar assessment scores exist in the literature. The clinical measurement of scar maturity can aid in determining end points for therapeutics. Tissue oxygen tension and color assessment of scars by standardized photography proved to be useful.In surgery, the use of dermal substitutes holds some promise as we surmise that quality scars that arise from dermal elements, molecular and enzyme behavior, and balance. Although a systematic review shows some benefit for earlier closure and healing of wounds, no such review exists at this point in time for the use of dermal substitutes in scars.Adipose-derived stem cell, as it pertains to scars, will hopefully realize the potential of skin regeneration rather than by repair in which we are familiar with as well as the undesirable scarring as a result of healing through the inflammatory

  16. Relationship between Regional Fat Distribution and Hypertrophic Cardiomyopathy Phenotype

    PubMed Central

    Guglielmi, Valeria; Maresca, Luciano; Lanzillo, Chiara; Marinoni, Giorgia Michela; D’Adamo, Monica; Di Roma, Mauro; Preziosi, Paolo; Bellia, Alfonso; Calò, Leonardo; Sbraccia, Paolo

    2016-01-01

    Background Hypertrophic cardiomyopathy (HCM), the most common genetic heart disease, is characterized by heterogeneous phenotypic expression. Body mass index has been associated with LV mass and heart failure symptoms in HCM. The aim of our study was to investigate whether regional (trunk, appendicular, epicardial) fat distribution and extent could be related to hypertrophy severity and pattern in HCM. Methods Cardiovascular magnetic resonance was performed in 32 subjects with echocardiography-based diagnosis of HCM (22M/10F, 57.2±12.6 years) characterized by predominant hypertrophy at the interventricular septum (IVS). Regional fat distribution was assessed by dual-energy X-ray absorptiometry. Results Gender differences were detected in maximum IVS thickness (M: 18.3±3.8 mm vs. F: 14.3±4 mm, p = 0.012), right ventricle (RV) systolic function (M: 61.3±6.7%; F: 67.5±6.3%, p = 0.048), indexed RV end-diastolic (M: 64.8±16.3 ml/m2; F: 50.7±15.5 ml/m2, p = 0.04) and end-systolic volumes (M: 24.3±8.3 ml/m2; F: 16.7±7.4 ml/m2, p = 0.04). After adjusting for age and gender, maximum IVS thickness was associated with truncal fat (Tr-FAT) (β = 0.43, p = 0.02), but not with either appendicular or epicardial fat. Epicardial fat resulted independently associated with NT-proBNP levels (β = 0.63, p = 0.04). Late Gadolinium Enhancement-positive subjects displayed greater maximum IVS thickness (p = 0.02), LV mass index (p = 0.015) and NT-proBNP levels (p = 0.04), but no associations with fat amount or distribution were observed. Conclusion Truncal, but not appendicular or epicardial fat amount, seems to be related with maximum IVS thickness, the hallmark feature in our cohort of HCM patients. Further prospective researches are needed to assess a potential causative effect of central adiposity on HCM phenotype. PMID:27388274

  17. Clinical Utility of Cardiovascular Magnetic Resonance in Hypertrophic Cardiomyopathy

    PubMed Central

    2012-01-01

    Hypertrophic cardiomyopathy (HCM) is characterized by substantial genetic and phenotypic heterogeneity, leading to considerable diversity in clinical course including the most common cause of sudden death in young people and a determinant of heart failure symptoms in patients of any age. Traditionally, two-dimensional echocardiography has been the most reliable method for establishing a clinical diagnosis of HCM. However, cardiovascular magnetic resonance (CMR), with its high spatial resolution and tomographic imaging capability, has emerged as a technique particularly well suited to characterize the diverse phenotypic expression of this complex disease. For example, CMR is often superior to echocardiography for HCM diagnosis, by identifying areas of segmental hypertrophy (ie., anterolateral wall or apex) not reliably visualized by echocardiography (or underestimated in terms of extent). High-risk HCM patient subgroups identified with CMR include those with thin-walled scarred LV apical aneurysms (which prior to CMR imaging in HCM remained largely undetected), end-stage systolic dysfunction, and massive LV hypertrophy. CMR observations also suggest that the cardiomyopathic process in HCM is more diffuse than previously regarded, extending beyond the LV myocardium to include thickening of the right ventricular wall as well as substantial morphologic diversity with regard to papillary muscles and mitral valve. These findings have implications for management strategies in patients undergoing invasive septal reduction therapy. Among HCM family members, CMR has identified unique phenotypic markers of affected genetic status in the absence of LV hypertrophy including: myocardial crypts, elongated mitral valve leaflets and late gadolinium enhancement. The unique capability of contrast-enhanced CMR with late gadolinium enhancement to identify myocardial fibrosis has raised the expectation that this may represent a novel marker, which may enhance risk stratification. At

  18. Myocardial Native T1 Time in Patients With Hypertrophic Cardiomyopathy.

    PubMed

    Kato, Shingo; Nakamori, Shiro; Bellm, Steven; Jang, Jihye; Basha, Tamer; Maron, Martin; Manning, Warren J; Nezafat, Reza

    2016-10-01

    In hypertrophic cardiomyopathy (HC), there are significant variations in left ventricular (LV) wall thickness and fibrosis, which necessitates a volumetric coverage. Slice-interleaved T1 (STONE) mapping sequence allows for the assessment of native T1 time with complete coverage of LV myocardium. The aims of this study were to evaluate spatial heterogeneity of native T1 time in patients with HC. Twenty-nine patients with HC (55 ± 16 years) and 15 healthy adult control subjects (46 ± 19 years) were studied. Native T1 mapping was performed using STONE sequence which enables acquisition of 5 slices in the short-axis plane within a 90 seconds free-breathing scan. We measured LV native T1 time and maximum LV wall thickness in each 16 segments from 3 slices (basal, midventricular and apical slice). Late gadolinium enhanced (LGE) magnetic resonance imaging was acquired to assess the presence of myocardial enhancement. In patients with HC, LV native T1 time was significantly elevated compared with healthy controls, regardless of the presence or absence of LGE (mean native T1 time; LGE positive segments from HC, 1,141 ± 46 ms; LGE negative segments from HC, 1,114 ± 56 ms; segments from healthy controls, 1,065 ± 35 ms, p <0.001). Elevation of native T1 time was defined as >1,135 ms, which was +2SD of native T1 time by STONE sequence in healthy controls. A total of 120 of 405 (30%) LGE negative segments from patients with HC showed elevated native T1 time. Prevalence of segments with elevated native T1 time for basal, midventricular, and apical slice was 29%, 25%, 38%, respectively. Significant correlation was found between LV wall thickness and LV native T1 time (y = 0.029 × -22.6, p <0.001 by Spearman's correlation coefficient). In conclusion, substantial number of segments without LGE showed elevation of native T1 time, and whole-heart T1 mapping revealed heterogeneity of myocardial native T1 time in patients with HC. PMID:27567135

  19. Left Atrial Mechanical Function and Global Strain in Hypertrophic Cardiomyopathy

    PubMed Central

    Yoon, Yeonyee E.; Kim, Hack-Lyoung; Lee, Seung-Pyo; Kim, Hyung-Kwan; Kim, Yong-Jin; Cho, Goo-Yeong; Zo, Joo-Hee; Sohn, Dae-Won

    2016-01-01

    Background Atrial fibrillation is the most common arrhythmia and is associated with adverse outcomes in hypertrophic cardiomyopathy (HCM). Although left atrial (LA) remodeling and dysfunction are known to associate with the development of atrial fibrillation in HCM, the changes of the LA in HCM patients remain unclear. This study aimed to evaluate the changes in LA size and mechanical function in HCM patients compared to control subjects and to determine the characteristics of HCM associated with LA remodeling and dysfunction. Methods Seventy-nine HCM patients (mean age, 54 ± 11 years; 76% were men) were compared to 79 age- and sex-matched controls (mean age, 54 ± 11 years; 76% were men) and 20 young healthy controls (mean age, 33 ± 5 years; 45% were men). The LA diameter, volume, and mechanical function, including global strain (ε), were evaluated by 2D-speckle tracking echocardiography. The phenotype of HCM, maximal left ventricular (LV) wall thickness, LV mass, and presence and extent of late gadolinium enhancement (LGE) were evaluated with cardiac magnetic resonance imaging. Results HCM patients showed increased LA volume index, impaired reservoir function, and decreased LA ε compared to the control subjects. When we divided the HCM group according to a maximal LA volume index (LAVImax) of 38.7 ml/m2 or LA ε of 21%, no significant differences in the HCM phenotype and maximal LV wall thickness were observed for patients with LAVImax >38.7 ml/m2 or LA ε ≤21%. Conversely, the LV mass index was significantly higher both in patients with maximal LA volume index >38.7 ml/m2 and with LA ε ≤21% and was independently associated with LAVImax and LA ε. Although the LGE extent was increased in patients with LA ε ≤21%, it was not independently associated with either LAVImax or LA ε. Conclusions HCM patients showed progressed LA remodeling and dysfunction; the determinant of LA remodeling and dysfunction was LV mass index rather than LV myocardial fibrosis

  20. Prediction of Sarcomere Mutations in Subclinical Hypertrophic Cardiomyopathy

    PubMed Central

    Captur, Gabriella; Lopes, Luis R.; Mohun, Timothy J.; Patel, Vimal; Li, Chunming; Bassett, Paul; Finocchiaro, Gherardo; Ferreira, Vanessa M.; Esteban, Maite Tome; Muthurangu, Vivek; Sherrid, Mark V.; Day, Sharlene M.; Canter, Charles E.; McKenna, William J.; Seidman, Christine E.; Bluemke, David A.; Elliott, Perry M.; Ho, Carolyn Y.; Moon, James C.

    2014-01-01

    Background Sarcomere protein mutations in hypertrophic cardiomyopathy (HCM) induce subtle cardiac structural changes prior to the development of left ventricular hypertrophy (LVH). We have proposed that myocardial crypts are part of this phenotype and independently associated with the presence of sarcomere gene mutations. We tested this hypothesis in genetic HCM pre-LVH (G+LVH−). Methods and Results A multi-centre case-control study investigated crypts and 22 other cardiovascular magnetic resonance (CMR) parameters in subclinical HCM to determine their strength of association with sarcomere gene mutation carriage. The G+LVH− sample (n=73) was 29±13 years old and 51% male. Crypts were related to the presence of sarcomere mutations (for ≥1 crypt, β=2.5, 95% confidence interval [CI] 0.5-4.4, p=0.014; for ≥2 crypts, β=3.0, 95%CI 0.8-7.9, p=0.004). In combination with 3 other parameters: anterior mitral valve leaflet (AMVL) elongation (β=2.1, 95%CI 1.7-3.1, p<0.001), abnormal LV apical trabeculae (β=1.6, 95%CI 0.8-2.5, p<0.001), and smaller LV end-systolic volumes (β=1.4, 95%CI 0.5-2.3, p=0.001), multiple crypts indicated the presence of sarcomere gene mutations with 80% accuracy and an area under the curve of 0.85 (95%CI 0.8-0.9). In this G+LVH− population cardiac myosin-binding protein C mutation carriers had twice the prevalence of crypts when compared to the other combined mutations (47 vs. 23%; odds ratio, 2.9; 95%CI 1.1–7.9; p=0.045). Conclusions The subclinical HCM phenotype measured by CMR in a multi-center environment and consisting of crypts (particularly multiple), AMVL elongation, abnormal trabeculae and smaller LV systolic cavity, is indicative of the presence of sarcomere gene mutations and highlights the need for further study. PMID:25228707

  1. MicroRNA 181b regulates decorin production by dermal fibroblasts and may be a potential therapy for hypertrophic scar.

    PubMed

    Kwan, Peter; Ding, Jie; Tredget, Edward E

    2015-01-01

    Hypertrophic scarring is a frequent fibroproliferative complication following deep dermal burns leading to impaired function and lifelong disfigurement. Decorin reduces fibrosis and induces regeneration in many tissues, and is significantly downregulated in hypertrophic scar and normal deep dermal fibroblasts. It was hypothesized that microRNAs in these fibroblasts downregulate decorin and blocking them would increase decorin and may prevent hypertrophic scarring. Lower decorin levels were found in hypertrophic scar as compared to normal skin, and in deep as compared to superficial dermis. A decorin 3' un-translated region reporter assay demonstrated microRNA decreased decorin in deep dermal fibroblasts, and microRNA screening predicted miR- 24, 181b, 421, 526b, or 543 as candidates. After finding increased levels of mir-181b in deep dermal fibroblasts, it was demonstrated that TGF-β1 stimulation decreased miR-24 but increased miR-181b and that hypertrophic scar and deep dermis contained increased levels of miR-181b. By blocking miR-181b with an antagomiR, it was possible to increase decorin protein expression in dermal fibroblasts. This suggests miR-181b is involved in the differential expression of decorin in skin and wound healing. Furthermore, blocking miR-181b reversed TGF-β1 induced decorin downregulation and myofibroblast differentiation in hypertrophic scar fibroblasts, suggesting a potential therapy for hypertrophic scar.

  2. [Molecular targets and novel pharmacological options to prevent myocardial hypertrophic remodeling].

    PubMed

    Coppini, Raffaele; Ferrantini, Cecilia; Poggesi, Corrado; Mugelli, Alessandro; Olivotto, Iacopo

    2016-03-01

    Myocardial hypertrophic remodeling is a pathophysiological feature of several cardiac conditions and is the hallmark of hypertrophic cardiomyopathy (HCM), the most common monogenic inherited disease of the heart. In recent years, preclinical and clinical studies investigated the underlying molecular mechanisms and intracellular signaling pathways involved in pathologic cardiomyocyte hypertrophy and highlighted a number of possible molecular targets of therapy aimed at preventing its development. Early prevention of myocardial hypertrophic remodeling is particularly sought after in HCM, as current therapeutic strategies are unable to remove the primary cause of disease, i.e. the disease-causing gene mutation. Studies on transgenic animal models or human myocardial samples from patients with HCM identified intracellular calcium overload as a central mechanism driving pathological hypertrophy. In this review, we analyze recent preclinical and clinical studies on animal models and patients with HCM aimed at preventing or modifying hypertrophic myocardial remodeling. Mounting evidence shows that prevention of pathological hypertrophy is a feasible strategy in HCM and will enter the clinical practice in the near future. Considering the close mechanistic similarities between HCM and secondary hypertrophy, these studies are also relevant for the common forms of cardiac hypertrophy, such as hypertensive or valvular heart disease. PMID:27029877

  3. The Metabolome in Finnish Carriers of the MYBPC3-Q1061X Mutation for Hypertrophic Cardiomyopathy

    PubMed Central

    Heliö, Tiina; Jääskeläinen, Pertti; Laine, Mika; Hilvo, Mika; Nieminen, Markku S.; Laakso, Markku; Hyötyläinen, Tuulia; Orešič, Matej; Kuusisto, Johanna

    2015-01-01

    Aims Mutations in the cardiac myosin-binding protein C gene (MYBPC3) are the most common genetic cause of hypertrophic cardiomyopathy (HCM) worldwide. The molecular mechanisms leading to HCM are poorly understood. We investigated the metabolic profiles of mutation carriers with the HCM-causing MYBPC3-Q1061X mutation with and without left ventricular hypertrophy (LVH) and non-affected relatives, and the association of the metabolome to the echocardiographic parameters. Methods and Results 34 hypertrophic subjects carrying the MYBPC3-Q1061X mutation, 19 non-hypertrophic mutation carriers and 20 relatives with neither mutation nor hypertrophy were examined using comprehensive echocardiography. Plasma was analyzed for molecular lipids and polar metabolites using two metabolomics platforms. Concentrations of branched chain amino acids, triglycerides and ether phospholipids were increased in mutation carriers with hypertrophy as compared to controls and non-hypertrophic mutation carriers, and correlated with echocardiographic LVH and signs of diastolic and systolic dysfunction in subjects with the MYBPC3-Q1061X mutation. Conclusions Our study implicates the potential role of branched chain amino acids, triglycerides and ether phospholipids in HCM, as well as suggests an association of these metabolites with remodeling and dysfunction of the left ventricle. PMID:26267065

  4. An FHL1-containing complex within the cardiomyocyte sarcomere mediates hypertrophic biomechanical stress responses in mice

    PubMed Central

    Sheikh, Farah; Raskin, Anna; Chu, Pao-Hsien; Lange, Stephan; Domenighetti, Andrea A.; Zheng, Ming; Liang, Xingqun; Zhang, Tong; Yajima, Toshitaka; Gu, Yusu; Dalton, Nancy D.; Mahata, Sushil K.; Dorn, Gerald W.; Heller-Brown, Joan; Peterson, Kirk L.; Omens, Jeffrey H.; McCulloch, Andrew D.; Chen, Ju

    2008-01-01

    The response of cardiomyocytes to biomechanical stress can determine the pathophysiology of hypertrophic cardiac disease, and targeting the pathways regulating these responses is a therapeutic goal. However, little is known about how biomechanical stress is sensed by the cardiomyocyte sarcomere to transduce intracellular hypertrophic signals or how the dysfunction of these pathways may lead to disease. Here, we found that four-and-a-half LIM domains 1 (FHL1) is part of a complex within the cardiomyocyte sarcomere that senses the biomechanical stress–induced responses important for cardiac hypertrophy. Mice lacking Fhl1 displayed a blunted hypertrophic response and a beneficial functional response to pressure overload induced by transverse aortic constriction. A link to the Gαq (Gq) signaling pathway was also observed, as Fhl1 deficiency prevented the cardiomyopathy observed in Gq transgenic mice. Mechanistic studies demonstrated that FHL1 plays an important role in the mechanism of pathological hypertrophy by sensing biomechanical stress responses via the N2B stretch sensor domain of titin and initiating changes in the titin- and MAPK-mediated responses important for sarcomere extensibility and intracellular signaling. These studies shed light on the physiological regulation of the sarcomere in response to hypertrophic stress. PMID:19033658

  5. Altering the Architecture of Tissue Engineered Hypertrophic Cartilaginous Grafts Facilitates Vascularisation and Accelerates Mineralisation

    PubMed Central

    Sheehy, Eamon J.; Vinardell, Tatiana; Toner, Mary E.; Buckley, Conor T.; Kelly, Daniel J.

    2014-01-01

    Cartilaginous tissues engineered using mesenchymal stem cells (MSCs) can be leveraged to generate bone in vivo by executing an endochondral program, leading to increased interest in the use of such hypertrophic grafts for the regeneration of osseous defects. During normal skeletogenesis, canals within the developing hypertrophic cartilage play a key role in facilitating endochondral ossification. Inspired by this developmental feature, the objective of this study was to promote endochondral ossification of an engineered cartilaginous construct through modification of scaffold architecture. Our hypothesis was that the introduction of channels into MSC-seeded hydrogels would firstly facilitate the in vitro development of scaled-up hypertrophic cartilaginous tissues, and secondly would accelerate vascularisation and mineralisation of the graft in vivo. MSCs were encapsulated into hydrogels containing either an array of micro-channels, or into non-channelled ‘solid’ controls, and maintained in culture conditions known to promote a hypertrophic cartilaginous phenotype. Solid constructs accumulated significantly more sGAG and collagen in vitro, while channelled constructs accumulated significantly more calcium. In vivo, the channels acted as conduits for vascularisation and accelerated mineralisation of the engineered graft. Cartilaginous tissue within the channels underwent endochondral ossification, producing lamellar bone surrounding a hematopoietic marrow component. This study highlights the potential of utilising engineering methodologies, inspired by developmental skeletal processes, in order to enhance endochondral bone regeneration strategies. PMID:24595316

  6. [Molecular targets and novel pharmacological options to prevent myocardial hypertrophic remodeling].

    PubMed

    Coppini, Raffaele; Ferrantini, Cecilia; Poggesi, Corrado; Mugelli, Alessandro; Olivotto, Iacopo

    2016-03-01

    Myocardial hypertrophic remodeling is a pathophysiological feature of several cardiac conditions and is the hallmark of hypertrophic cardiomyopathy (HCM), the most common monogenic inherited disease of the heart. In recent years, preclinical and clinical studies investigated the underlying molecular mechanisms and intracellular signaling pathways involved in pathologic cardiomyocyte hypertrophy and highlighted a number of possible molecular targets of therapy aimed at preventing its development. Early prevention of myocardial hypertrophic remodeling is particularly sought after in HCM, as current therapeutic strategies are unable to remove the primary cause of disease, i.e. the disease-causing gene mutation. Studies on transgenic animal models or human myocardial samples from patients with HCM identified intracellular calcium overload as a central mechanism driving pathological hypertrophy. In this review, we analyze recent preclinical and clinical studies on animal models and patients with HCM aimed at preventing or modifying hypertrophic myocardial remodeling. Mounting evidence shows that prevention of pathological hypertrophy is a feasible strategy in HCM and will enter the clinical practice in the near future. Considering the close mechanistic similarities between HCM and secondary hypertrophy, these studies are also relevant for the common forms of cardiac hypertrophy, such as hypertensive or valvular heart disease.

  7. Enhanced in Vivo Delivery of 5-Fluorouracil by Ethosomal Gels in Rabbit Ear Hypertrophic Scar Model

    PubMed Central

    Wo, Yan; Zhang, Zheng; Zhang, Yixin; Zhang, Zhen; Wang, Kan; Mao, Xiaohui; Su, Weijie; Li, Ke; Cui, Daxiang; Chen, Jun

    2014-01-01

    Applying Ethosomal Gels (EGs) in transdermal drug delivery systems has evoked considerable interest because of their good water-solubility and biocompatibility. However, there has not been an explicit description of applying EGs as a vehicle for hypertrophic scars treatment. Here, a novel transdermal EGs loaded with 5-fluorouracil (5-FU EGs) was successfully prepared and characterized. The stability assay in vitro revealed that 5-FU EGs stored for a period of 30 days at 4 ± 1 °C had a better size stability than that at 25 ± 1 °C. Furthermore, using confocal laser scanning microscopy, EGs labeled with Rhodamine 6 G penetrated into the deep dermis of the hypertrophic scar within 24 h in the rabbit ear hypertrophic model suggested that the EGs were an optional delivery carrier through scar tissues. In addition, the value of the Scar Elevation Index (SEI) of 5-FU EGs group in the rabbit ear scar model was lower than that of 5-FU Phosphate Buffered Saline gel and Control groups. To conclude, these results suggest that EGs delivery system loaded 5-fluorouracil is a perfect candidate drug for hypertrophic scars therapy in future. PMID:25501333

  8. Hypertrophic Pyloric Stenosis developing In a Patient Operated for Patent Urachus – A Case Report

    PubMed Central

    Jangid, Manoj Kumar; Yadav, Sunil Kumar; Taqi, Esmaeel

    2014-01-01

    A neonate with patent urachus (PU) who later developed hypertrophic pyloric stenosis (HPS) is being reported. The newborn was first operated for PU; post-operatively he developed persistent vomiting and radiological workup confirmed HPS. Pyloromyotomy was performed with an uneventful recovery. PMID:25057473

  9. Dietary copper supplementation reverses hypertrophic cardiomyopathy induced by chronic pressure overload in mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sustained pressure overload causes cardiac hypertrophy and the transition to heart failure. We show here that dietary supplementation with physiologically relevant levels of copper (Cu) reverses pre-established hypertrophic cardiomyopathy in the presence of pressure overload induced by ascending aor...

  10. Mid-ventricular obstructive hypertrophic cardiomyopathy with an apical aneurysm caused by vasospastic angina.

    PubMed

    Kiyooka, Takahiko; Satoh, Yasuhiro

    2014-03-20

    Mid-ventricular obstructive hypertrophic cardiomyopathy (MVOHCM) is a rare form of cardiomyopathy, characterized by the presence of a pressure gradient between the left ventricular basal and apical chambers and is frequently associated with an apical aneurysm. However, the exact cause of this aneurysm remains unknown. We here describe a patient with MVOHCM in whom the apical aneurysm may be caused by vasospastic angina.

  11. Hair-thread tourniquet syndrome of the hypertrophic clitoris in a 6-year-old girl.

    PubMed

    Parlak, Mesut; Karakaya, Ali Erdal

    2015-05-01

    Hair-thread tourniquet syndrome is defined as the ischemic strangulation of hair resulting in edema and severe pain and may cause amputation of organs. Strangulation of the external genitalia (clitoris, labia minora) has rarely been described in girls. Here, we present a case of hypertrophic clitoris injury secondary to hair strangulation in a 6-year-old girl.

  12. Missense mutation of the {beta}-cardiac myosin heavy-chain gene in hypertrophic cardiomyopathy

    SciTech Connect

    Arai, Shoichi; Matsuoka, Rumiko; Hirayama, Kenji; Sakurai, Hisanao

    1995-09-11

    Hypertrophic cardiomyopathy occurs as an autosomal dominant familial disorder or as a sporadic disease without familial involvement. We describe a missense mutation of the {beta}-cardiac myosin heavy chain (MHC) gene, a G to T transversion (741 Gly{r_arrow}Trp) identified by direct sequencing of exon 20 in four individuals affected with familial hypertrophic cardiomyopathy. Three individuals with sporadic hypertrophic cardiomyopathy, whose parents are clinically and genetically unaffected, had sequence variations of exon 34 of the {alpha}-cardiac MHC gene (a C to T transversion, 1658 Asp{r_arrow}Asp, resulting in FokI site polymorphism), of intron 33 of the {alpha}-cardiac MHC gene (a G to A and an A to T transversion), and also of intron 14 of the {beta}-cardiac MHC gene (a C to T transversion in a patient with Noonan syndrome). Including our case, 30 missense mutations of the {beta}-cardiac MHC gene in 49 families have been reported thus far worldwide. Almost all are located in the region of the gene coding for the globular head of the molecule, and only one mutation was found in both Caucasian and Japanese families. Missense mutations of the {Beta}-cardiac MHC gene in hypertrophic cardiomyopathy may therefore differ according to race. 29 refs., 6 figs., 3 tabs.

  13. Poincaré wave-induced shear instability in Lake Michigan

    NASA Astrophysics Data System (ADS)

    Hsieh, T.; Troy, C. D.; Hawley, N.

    2012-12-01

    Cross-thermocline mixing is an important process during the stratified period in the Great Lakes, especially in the lake interiors. Recent evidence suggests that basin-scale mixing in the world's largest lakes may actually occur primarily in the lake interiors. Several years of velocity and temperature data are examined from Lake Michigan in order to examine processes that are potentially responsible for cross-thermocline mixing. Near-inertial internal Poincaré waves are shown to thoroughly dominate surface currents and thermocline shear in Lake Michigan's deeper waters. Empirical orthogonal function decomposition of the observed velocity fields show that a vertical mode 1 Poincaré wave is dominant and responsible for most of the observed thermocline shear. Calculated Richardson numbers, observed microstructure, and stability analysis suggest that these waves do cause cross-thermocline mixing, and that high-resolution epxperiments are necessary to better quantify mixing in the interior of Lake Michigan.

  14. Insight into dissolved organic matter fractions in Lake Wivenhoe during and after a major flood.

    PubMed

    Aryal, Rupak; Grinham, Alistair; Beecham, Simon

    2016-03-01

    Dissolved organic matter is an important component of biogeochemical processes in aquatic environments. Dissolved organic matter may consist of a myriad of different fractions and resultant processing pathways. In early January 2011, heavy rainfall occurred across South East Queensland, Australia causing significant catchment inflow into Lake Wivenhoe, which is the largest water supply reservoir for the city of Brisbane, Australia. The horizontal and vertical distributions of dissolved organic matter fractions in the lake during the flood period were investigated and then compared with stratified conditions with no catchment inflows. The results clearly demonstrate a large variation in dissolved organic matter fractions associated with inflow conditions compared with stratified conditions. During inflows, dissolved organic matter concentrations in the reservoir were fivefold lower than during stratified conditions. Within the dissolved organic matter fractions during inflow, the hydrophobic and humic acid fractions were almost half those recorded during the stratified period whilst low molecular weight neutrals were higher during the flood period compared to during the stratified period. Information on dissolved organic matter and the spatial and vertical variations in its constituents' concentrations across the lake can be very useful for catchment and lake management and for selecting appropriate water treatment processes.

  15. Insight into dissolved organic matter fractions in Lake Wivenhoe during and after a major flood.

    PubMed

    Aryal, Rupak; Grinham, Alistair; Beecham, Simon

    2016-03-01

    Dissolved organic matter is an important component of biogeochemical processes in aquatic environments. Dissolved organic matter may consist of a myriad of different fractions and resultant processing pathways. In early January 2011, heavy rainfall occurred across South East Queensland, Australia causing significant catchment inflow into Lake Wivenhoe, which is the largest water supply reservoir for the city of Brisbane, Australia. The horizontal and vertical distributions of dissolved organic matter fractions in the lake during the flood period were investigated and then compared with stratified conditions with no catchment inflows. The results clearly demonstrate a large variation in dissolved organic matter fractions associated with inflow conditions compared with stratified conditions. During inflows, dissolved organic matter concentrations in the reservoir were fivefold lower than during stratified conditions. Within the dissolved organic matter fractions during inflow, the hydrophobic and humic acid fractions were almost half those recorded during the stratified period whilst low molecular weight neutrals were higher during the flood period compared to during the stratified period. Information on dissolved organic matter and the spatial and vertical variations in its constituents' concentrations across the lake can be very useful for catchment and lake management and for selecting appropriate water treatment processes. PMID:26837382

  16. Background oriented schlieren in a density stratified fluid

    NASA Astrophysics Data System (ADS)

    Verso, Lilly; Liberzon, Alex

    2015-10-01

    Non-intrusive quantitative fluid density measurement methods are essential in the stratified flow experiments. Digital imaging leads to synthetic schlieren methods in which the variations of the index of refraction are reconstructed computationally. In this study, an extension to one of these methods, called background oriented schlieren, is proposed. The extension enables an accurate reconstruction of the density field in stratified liquid experiments. Typically, the experiments are performed by the light source, background pattern, and the camera positioned on the opposite sides of a transparent vessel. The multimedia imaging through air-glass-water-glass-air leads to an additional aberration that destroys the reconstruction. A two-step calibration and image remapping transform are the key components that correct the images through the stratified media and provide a non-intrusive full-field density measurements of transparent liquids.

  17. Background oriented schlieren in a density stratified fluid.

    PubMed

    Verso, Lilly; Liberzon, Alex

    2015-10-01

    Non-intrusive quantitative fluid density measurement methods are essential in the stratified flow experiments. Digital imaging leads to synthetic schlieren methods in which the variations of the index of refraction are reconstructed computationally. In this study, an extension to one of these methods, called background oriented schlieren, is proposed. The extension enables an accurate reconstruction of the density field in stratified liquid experiments. Typically, the experiments are performed by the light source, background pattern, and the camera positioned on the opposite sides of a transparent vessel. The multimedia imaging through air-glass-water-glass-air leads to an additional aberration that destroys the reconstruction. A two-step calibration and image remapping transform are the key components that correct the images through the stratified media and provide a non-intrusive full-field density measurements of transparent liquids.

  18. Unsteady Shear Disturbances Within a Two Dimensional Stratified Flow

    NASA Technical Reports Server (NTRS)

    Yokota, Jeffrey W.

    1992-01-01

    The origin and evolution of shear disturbances within a stratified, inviscid, incompressible flow are investigated numerically by a Clebsch/Weber decomposition based scheme. In contrast to homogeneous flows, within which vorticity can be redistributed but not generated, the presence of a density stratification can render an otherwise irrotational flow vortical. In this work, a kinematic decomposition of the unsteady Euler equations separates the unsteady velocity field into rotational and irrotational components. The subsequent evolution of these components is used to study the influence various velocity disturbances have on both stratified and homogeneous flows. In particular, the flow within a two-dimensional channel is used to investigate the evolution of rotational disturbances, generated or convected, downstream from an unsteady inflow condition. Contrasting simulations of both stratified and homogeneous flows are used to distinguish between redistributed inflow vorticity and that which is generated by a density stratification.

  19. Wakes of Self-propelled Bodies in Stratified Fluids

    NASA Astrophysics Data System (ADS)

    Voropayev, S. I.; Fernando, H. J. S.

    2008-11-01

    Using high Reynolds number (Re=10^4-10^5) experiments, the dynamics of stratified momentum wakes of self-propelled underwater and surface bodies were studied in (i) deep linearly stratified (deep ocean pycnocline), (ii) two layer (shallow pycnocline), and (iii) surface stratified (turbocline) fluids, and theoretical models wee advanced to explain the flow behavior. These models: (i) predict conditions under which submerged wakes signatures penetrate to the water surface, as expressed by the Confinement and Contrast numbers, and (ii) describe IR (infra-red) surface wakes signatures, as expressed by the Contrast and modified Froude numbers. If decaying turbulence is present surrounding the wake, the penetration of wake signature to the surface is still possible. Estimates for typical oceanic cases are given. PIV, LIF and high sensitivity Infrared Imaging cameras were employed for flow diagnostics.

  20. The FOCUS4 design for biomarker stratified trials.

    PubMed

    Kaplan, Richard

    2015-09-01

    Randomised clinical trials (RCTs) remain the gold standard of evidence for the benefit of new therapeutics but standard designs fit awkwardly with key developments in biomarker-stratified drug development. Firstly, the unprecedented number of new agents being developed in oncology (usually with specific targets for which there may be predictive biomarkers) mandates a need for new trial designs that are more efficient in screening out new agents with modest likelihood of benefit, concentrating resources on the most promising ones. The multi-arm multi-stage (MAMS) design developed some years ago addresses this need. Secondly, biomarker-stratified trials, when tackled one biomarker/drug pairing at a time, are inherently highly inefficient. The FOCUS4 trial design was developed to overcome this problem, using a platform that incorporates multiple parallel biomarker-stratified RCTs in individual cohorts, and capable of adapting its design in response to developing evidence.

  1. Thermal Vibrational Convection in a Two-phase Stratified Liquid

    NASA Technical Reports Server (NTRS)

    Chang, Qingming; Alexander, J. Iwan D.

    2007-01-01

    The response of a two-phase stratified liquid system subject to a vibration parallel to an imposed temperature gradient is analyzed using a hybrid thermal lattice Boltzmann method (HTLB). The vibrations considered correspond to sinusoidal translations of a rigid cavity at a fixed frequency. The layers are thermally and mechanically coupled. Interaction between gravity-induced and vibration-induced thermal convection is studied. The ability of applied vibration to enhance the flow, heat transfer and interface distortion is investigated. For the range of conditions investigated, the results reveal that the effect of vibrational Rayleigh number and vibrational frequency on a two-phase stratified fluid system is much different than that for a single-phase fluid system. Comparisons of the response of a two-phase stratified fluid system with a single-phase fluid system are discussed.

  2. SINDA/FLUINT Stratified Tank Modeling for Cryrogenic Propellant Tanks

    NASA Technical Reports Server (NTRS)

    Sakowski, Barbara

    2014-01-01

    A general purpose SINDA/FLUINT (S/F) stratified tank model was created to simulate self-pressurization and axial jet TVS; Stratified layers in the vapor and liquid are modeled using S/F lumps.; The stratified tank model was constructed to permit incorporating the following additional features:, Multiple or singular lumps in the liquid and vapor regions of the tank, Real gases (also mixtures) and compressible liquids, Venting, pressurizing, and draining, Condensation and evaporation/boiling, Wall heat transfer, Elliptical, cylindrical, and spherical tank geometries; Extensive user logic is used to allow detailed tailoring - Don't have to rebuilt everything from scratch!!; Most code input for a specific case is done through the Registers Data Block:, Lump volumes are determined through user input:; Geometric tank dimensions (height, width, etc); Liquid level could be input as either a volume percentage of fill level or actual liquid level height

  3. [Obstruction of the right ventricular outflow tract on the obstructive hypertrophic cardiomyopathy. Case report and literature review].

    PubMed

    Soriano, Patricia Pérez; Estrada, Catalina Lomelí; Peralta, Martin Rosas; Negrete, J Antonio Lorenzo; González, Celso Mendoza; Ortiz, Arturo Méndez; Attié, Fause

    2008-01-01

    OHC is a disorder with a broad spectrum of morphological, functional and genetics abnormalities. The Obstruction on the Right Ventricular Outflow (OHCRV) is not expected most of the time, that's way it is not usually detected and rarely mentioned in the cardiological literature. Its clinical presentation may include basically systemic venous hypertension symptoms that come with the hypertrophic cardyomiopathy manifestations. The manifestations of an apparent Right Ventricular Hypertrophic (RVH) in the ECG are probably due to the huge septal vector that activates the septum with a major thickness. The clinical confirmation of the obstruction on the OHCRV produced by a considerable asymmetric septal hypertrophic is easily shown with bidimensional an Doppler echocardiography.

  4. Dual pathways to endochondral osteoblasts: a novel chondrocyte-derived osteoprogenitor cell identified in hypertrophic cartilage

    PubMed Central

    Park, Jung; Gebhardt, Matthias; Golovchenko, Svitlana; Perez-Branguli, Francesc; Hattori, Takako; Hartmann, Christine; Zhou, Xin; deCrombrugghe, Benoit; Stock, Michael; Schneider, Holm; von der Mark, Klaus

    2015-01-01

    According to the general understanding, the chondrocyte lineage terminates with the elimination of late hypertrophic cells by apoptosis in the growth plate. However, recent cell tracking studies have shown that murine hypertrophic chondrocytes can survive beyond “terminal” differentiation and give rise to a progeny of osteoblasts participating in endochondral bone formation. The question how chondrocytes convert into osteoblasts, however, remained open. Following the cell fate of hypertrophic chondrocytes by genetic lineage tracing using BACCol10;Cre induced YFP-reporter gene expression we show that a progeny of Col10Cre-reporter labelled osteoprogenitor cells and osteoblasts appears in the primary spongiosa and participates – depending on the developmental stage – substantially in trabecular, endosteal, and cortical bone formation. YFP+ trabecular and endosteal cells isolated by FACS expressed Col1a1, osteocalcin and runx2, thus confirming their osteogenic phenotype. In searching for transitory cells between hypertrophic chondrocytes and trabecular osteoblasts we identified by confocal microscopy a novel, small YFP+Osx+ cell type with mitotic activity in the lower hypertrophic zone at the chondro-osseous junction. When isolated from growth plates by fractional enzymatic digestion, these cells termed CDOP (chondrocyte-derived osteoprogenitor) cells expressed bone typical genes and differentiated into osteoblasts in vitro. We propose the Col10Cre-labeled CDOP cells mark the initiation point of a second pathway giving rise to endochondral osteoblasts, alternative to perichondrium derived osteoprogenitor cells. These findings add to current concepts of chondrocyte-osteocyte lineages and give new insight into the complex cartilage-bone transition process in the growth plate. PMID:25882555

  5. A New 4D Trajectory-Based Approach Unveils Abnormal LV Revolution Dynamics in Hypertrophic Cardiomyopathy

    PubMed Central

    Madeo, Andrea; Piras, Paolo; Re, Federica; Gabriele, Stefano; Nardinocchi, Paola; Teresi, Luciano; Torromeo, Concetta; Chialastri, Claudia; Schiariti, Michele; Giura, Geltrude; Evangelista, Antonietta; Dominici, Tania; Varano, Valerio; Zachara, Elisabetta; Puddu, Paolo Emilio

    2015-01-01

    The assessment of left ventricular shape changes during cardiac revolution may be a new step in clinical cardiology to ease early diagnosis and treatment. To quantify these changes, only point registration was adopted and neither Generalized Procrustes Analysis nor Principal Component Analysis were applied as we did previously to study a group of healthy subjects. Here, we extend to patients affected by hypertrophic cardiomyopathy the original approach and preliminarily include genotype positive/phenotype negative individuals to explore the potential that incumbent pathology might also be detected. Using 3D Speckle Tracking Echocardiography, we recorded left ventricular shape of 48 healthy subjects, 24 patients affected by hypertrophic cardiomyopathy and 3 genotype positive/phenotype negative individuals. We then applied Generalized Procrustes Analysis and Principal Component Analysis and inter-individual differences were cleaned by Parallel Transport performed on the tangent space, along the horizontal geodesic, between the per-subject consensuses and the grand mean. Endocardial and epicardial layers were evaluated separately, different from many ecocardiographic applications. Under a common Principal Component Analysis, we then evaluated left ventricle morphological changes (at both layers) explained by first Principal Component scores. Trajectories’ shape and orientation were investigated and contrasted. Logistic regression and Receiver Operating Characteristic curves were used to compare these morphometric indicators with traditional 3D Speckle Tracking Echocardiography global parameters. Geometric morphometrics indicators performed better than 3D Speckle Tracking Echocardiography global parameters in recognizing pathology both in systole and diastole. Genotype positive/phenotype negative individuals clustered with patients affected by hypertrophic cardiomyopathy during diastole, suggesting that incumbent pathology may indeed be foreseen by these methods

  6. A new 4D trajectory-based approach unveils abnormal LV revolution dynamics in hypertrophic cardiomyopathy.

    PubMed

    Madeo, Andrea; Piras, Paolo; Re, Federica; Gabriele, Stefano; Nardinocchi, Paola; Teresi, Luciano; Torromeo, Concetta; Chialastri, Claudia; Schiariti, Michele; Giura, Geltrude; Evangelista, Antonietta; Dominici, Tania; Varano, Valerio; Zachara, Elisabetta; Puddu, Paolo Emilio

    2015-01-01

    The assessment of left ventricular shape changes during cardiac revolution may be a new step in clinical cardiology to ease early diagnosis and treatment. To quantify these changes, only point registration was adopted and neither Generalized Procrustes Analysis nor Principal Component Analysis were applied as we did previously to study a group of healthy subjects. Here, we extend to patients affected by hypertrophic cardiomyopathy the original approach and preliminarily include genotype positive/phenotype negative individuals to explore the potential that incumbent pathology might also be detected. Using 3D Speckle Tracking Echocardiography, we recorded left ventricular shape of 48 healthy subjects, 24 patients affected by hypertrophic cardiomyopathy and 3 genotype positive/phenotype negative individuals. We then applied Generalized Procrustes Analysis and Principal Component Analysis and inter-individual differences were cleaned by Parallel Transport performed on the tangent space, along the horizontal geodesic, between the per-subject consensuses and the grand mean. Endocardial and epicardial layers were evaluated separately, different from many ecocardiographic applications. Under a common Principal Component Analysis, we then evaluated left ventricle morphological changes (at both layers) explained by first Principal Component scores. Trajectories' shape and orientation were investigated and contrasted. Logistic regression and Receiver Operating Characteristic curves were used to compare these morphometric indicators with traditional 3D Speckle Tracking Echocardiography global parameters. Geometric morphometrics indicators performed better than 3D Speckle Tracking Echocardiography global parameters in recognizing pathology both in systole and diastole. Genotype positive/phenotype negative individuals clustered with patients affected by hypertrophic cardiomyopathy during diastole, suggesting that incumbent pathology may indeed be foreseen by these methods. Left

  7. Anti-inflammatory cytokine TSG-6 inhibits hypertrophic scar formation in a rabbit ear model.

    PubMed

    Wang, Hui; Chen, Zhao; Li, Xiao-Jing; Ma, Li; Tang, Yue-Ling

    2015-03-15

    Hypertrophic scars are characterized by excessive fibrosis and extracellular matrix (ECM) deposition and can be functionally and cosmetically problematic; however, there are few satisfactory treatments for controlling hypertrophic scars. The inflammatory cells and cytokines involved in excessive inflammation during wound healing facilitate fibroblast proliferation and collagen deposition, leading to pathologic scar formation. TSG-6 exhibits anti-inflammatory activity. This study examined the effect of recombinant TSG-6 on inflammation in hypertrophic scars using a rabbit ear model. Six 7-mm, full-thickness, circular wounds were made on the ears of 12 rabbits. TSG-6 and PBS were intradermally injected into the right and left ear wounds, respectively. The methods of TEM and TUNEL were used to detect fibroblast apoptosis. The expressions of inflammatory factors: IL-1β, IL-6 and TNF-α, were detected by immunohistochemistry and real time polymerase chain reaction. Collagen I and III expression detected by immunohistochemistry and Masson׳s trichrome staining and SEI (scar elevation index) was used to evaluate the extent of scarring. TSG-6 injection mitigated the formation of a hypertrophic scar in the rabbit ear. TSG-6-treated wounds exhibited decreased inflammation compared with the control group, as evidenced by the lower levels of IL-1β, IL-6, TNF-α and MPO. The SEI and the synthesis of collagens I and III were significantly decreased in the TSG-6-treated scars compared with control scars. The apoptosis rate was higher in the TSG-6-treated scars. TSG-6 exhibited anti-inflammatory effects during the wound healing process and cicatrization and significantly diminished hypertrophic scar formation in a rabbit ear model.

  8. miR-182 Modulates Myocardial Hypertrophic Response Induced by Angiogenesis in Heart

    PubMed Central

    Li, Na; Hwangbo, Cheol; Jaba, Irina M.; Zhang, Jiasheng; Papangeli, Irinna; Han, Jinah; Mikush, Nicole; Larrivée, Bruno; Eichmann, Anne; Chun, Hyung J.; Young, Lawrence H.; Tirziu, Daniela

    2016-01-01

    Myocardial hypertrophy is an adaptive response to hemodynamic demands. Although angiogenesis is critical to support the increase in heart mass with matching blood supply, it may also promote a hypertrophic response. Previously, we showed that cardiac angiogenesis induced by placental growth factor (PlGF), promotes myocardial hypertrophy through the paracrine action of endothelium-derived NO, which triggers the degradation of regulator of G protein signaling 4 (RGS4) to activate the Akt/mTORC1 pathways in cardiomyocytes. Here, we investigated whether miRNAs contribute to the development of hypertrophic response associated with myocardial angiogenesis. We show that miR-182 is upregulated concurrently with the development of hypertrophy in PlGF mice, but not when hypertrophy was blocked by concomitant expression of PlGF and RGS4, or by PlGF expression in eNOS−/− mice. Anti-miR-182 treatment inhibits the hypertrophic response and prevents the Akt/mTORC1 activation in PlGF mice and NO-treated cardiomyocytes. miR-182 reduces the expression of Bcat2, Foxo3 and Adcy6 to regulate the hypertrophic response in PlGF mice. Particularly, depletion of Bcat2, identified as a new miR-182 target, promotes AktSer473/p70-S6KThr389 phosphorylation and cardiomyocyte hypertrophy. LV pressure overload did not upregulate miR-182. Thus, miR-182 is a novel target of endothelial-cardiomyocyte crosstalk and plays an important role in the angiogenesis induced-hypertrophic response. PMID:26888314

  9. miR-182 Modulates Myocardial Hypertrophic Response Induced by Angiogenesis in Heart.

    PubMed

    Li, Na; Hwangbo, Cheol; Jaba, Irina M; Zhang, Jiasheng; Papangeli, Irinna; Han, Jinah; Mikush, Nicole; Larrivée, Bruno; Eichmann, Anne; Chun, Hyung J; Young, Lawrence H; Tirziu, Daniela

    2016-01-01

    Myocardial hypertrophy is an adaptive response to hemodynamic demands. Although angiogenesis is critical to support the increase in heart mass with matching blood supply, it may also promote a hypertrophic response. Previously, we showed that cardiac angiogenesis induced by placental growth factor (PlGF), promotes myocardial hypertrophy through the paracrine action of endothelium-derived NO, which triggers the degradation of regulator of G protein signaling 4 (RGS4) to activate the Akt/mTORC1 pathways in cardiomyocytes. Here, we investigated whether miRNAs contribute to the development of hypertrophic response associated with myocardial angiogenesis. We show that miR-182 is upregulated concurrently with the development of hypertrophy in PlGF mice, but not when hypertrophy was blocked by concomitant expression of PlGF and RGS4, or by PlGF expression in eNOS(-/-) mice. Anti-miR-182 treatment inhibits the hypertrophic response and prevents the Akt/mTORC1 activation in PlGF mice and NO-treated cardiomyocytes. miR-182 reduces the expression of Bcat2, Foxo3 and Adcy6 to regulate the hypertrophic response in PlGF mice. Particularly, depletion of Bcat2, identified as a new miR-182 target, promotes Akt(Ser473)/p70-S6K(Thr389) phosphorylation and cardiomyocyte hypertrophy. LV pressure overload did not upregulate miR-182. Thus, miR-182 is a novel target of endothelial-cardiomyocyte crosstalk and plays an important role in the angiogenesis induced-hypertrophic response. PMID:26888314

  10. Stratified flows and internal waves in the Central West Atlantic

    NASA Astrophysics Data System (ADS)

    Grigorenko, K. S.; Makarenko, N. I.; Morozov, E. G.; Tarakanov, R. Yu; Frey, D. I.

    2016-06-01

    In this paper, we study stratified flows and internal waves in the fracture zones of the Mid Atlantic Ridge. The results of measurements carried out in the 39th and 40th cruises of RV Akademik Sergey Vavilov in the autumn of 2014 and 2015 are presented. Hydrophysical properties of the near-bottom flows are studied experimentally on the basis of CTD- and LADCP profiling. Theoretical analysis involves mathematical formulation of stratified fluid flow which uses CTD-data obtained from field observation in the Vema Fracture Zone region. Spectral properties and kinematic characteristics of internal waves are calculated by finite element method.

  11. Using a fast Fourier method to model sound propagation in a stratified atmosphere over a stratified porous-elastic ground

    NASA Technical Reports Server (NTRS)

    Tooms, S.; Attenborough, K.

    1990-01-01

    Using a Fast Fourier integration method and a global matrix method for solution of the boundary condition equations at all interfaces simultaneously, a useful tool for predicting acoustic propagation in a stratified fluid over a stratified porous-elastic solid was developed. The model for the solid is a modified Biot-Stoll model incorporating four parameters describing the pore structure corresponding to the Rayleigh-Attenborough rigid-porous structure model. The method is also compared to another Fast Fourier code (CERL-FFP) which models the ground as an impedance surface under a horizontally stratified air. Agreement with the CERL FFP is good. The effects on sound propagation of a combination of ground elasticity, complex ground structure, and atmospheric conditions are demonstrated by theoretical results over a snow layer, and experimental results over a model ground surface.

  12. Modeling the carbon cycle in Lake Matano.

    PubMed

    Kuntz, L B; Laakso, T A; Schrag, D P; Crowe, S A

    2015-09-01

    Lake Matano, Indonesia, is a stratified anoxic lake with iron-rich waters that has been used as an analogue for the Archean and early Proterozoic oceans. Past studies of Lake Matano report large amounts of methane production, with as much as 80% of primary production degraded via methanogenesis. Low δ(13)C values of DIC in the lake are difficult to reconcile with this notion, as fractionation during methanogenesis produces isotopically heavy CO2. To help reconcile these observations, we develop a box model of the carbon cycle in ferruginous Lake Matano, Indonesia, that satisfies the constraints of CH4 and DIC isotopic profiles, sediment composition, and alkalinity. We estimate methane fluxes smaller than originally proposed, with about 9% of organic carbon export to the deep waters degraded via methanogenesis. In addition, despite the abundance of Fe within the waters, anoxic ferric iron respiration of organic matter degrades <3% of organic carbon export, leaving methanogenesis as the largest contributor to anaerobic organic matter remineralization, while indicating a relatively minor role for iron as an electron acceptor. As the majority of carbon exported is buried in the sediments, we suggest that the role of methane in the Archean and early Proterozoic oceans is less significant than presumed in other studies.

  13. Echocardiography Differences Between Athlete’s Heart Hearth and Hypertrophic Cardiomyopathy

    PubMed Central

    Kreso, Amir; Barakovic, Fahir; Medjedovic, Senad; Halilbasic, Amila; Klepic, Muhamed

    2015-01-01

    Introduction: Among long term athletes there is always present hypertrophy of the left ventricle walls as well as increased cardiac mass. These changes are the result of the heart muscle adaptation to load during the years of training, which should not be considered as pathology. In people suffering from hypertrophic cardiomyopathy (HCM), there is also present hypertrophy of the left ventricle walls and increased mass of the heart, but these changes are the result of pathological changes in the heart caused by a genetic predisposition for the development HCM of. Differences between myocardial hypertrophy in athletes and HCM are not clearly differentiated and there are always dilemmas between pathological and physiological hypertrophy. The goal of the study is to determine and compare the echocardiographic cardiac parameters of longtime athletes to patients with hypertrophic cardiomyopathy. Material and methods: The study included 60 subjects divided into two groups: active athletes and people with hypertrophic cardiomyopathy. Results: Mean values of IVSd recorded in GB is IVSd=17.5 mm (n=20, 95% CI, 16.00–19.00 mm), while a significantly smaller mean value is recorded in GA, IVSd=10.0 mm (n=40, 95% CI, 9.00-11.00 mm). The mean value of the left ventricle in diastole (LVDd) recorded in the GA is LVDd=51 mm (n=40; 95% CI, 48.00 to 52.00 mm), while in the group with hypertrophic cardiomyopathy (GB) mean LVDd value is 42 mm (n=20; 95% CI, 40.00 to 48.00 mm). The mean value of the rear wall of the left ventricle (LVPWd) recorded in the GA is LVDd=10 mm (n=40; 95% CI, 9.00-10.00 mm) while in the group with hypertrophic cardiomyopathy (GB) mean LVDd is 14 mm (n=20; 95% CI, 12.00 to 16.00 mm). The mean of the left ventricle during systole (LVSD) observed in GA is LVSD=34 mm (n=40; 95% CI, 32.00 to 36.00 mm), while in the group with hypertrophic cardiomyopathy (GB) mean LVSD is 28 mm (n=20; 95% CI, 24.00 to 28.83 mm). The mean ejection fraction (EF%) observed in GA is EF

  14. Impingement of buoyancy-driven flows at a stratified interface

    NASA Astrophysics Data System (ADS)

    Cotel, Aline J.; Kudo, Yuriko

    2008-07-01

    Laser-induced fluorescence (LIF) and particle-image velocimetry (PIV) are used to study both thermals and plumes impinging on a stratified interface. Data are obtained for a central slice of the flow near the stratified interface. Both the thermal and plume are generated by releasing fresh water at the bottom of a tank filled with two layers of salt water of different densities. Thermals and plumes are studied at Reynolds numbers ranging from 3,000 to 8,000, above the value for the mixing transition, a Schmidt number of about 600, and Richardson numbers from 1 to 22. The Richardson and Reynolds numbers are based on the thermal or plume characteristics (size and vertical velocity) before impingement and the initial density difference across the interface. Laser-induced fluorescence (LIF) is used to determine the maximum penetration height, rebound distance and lateral spreading velocity. The vorticity results obtained from the PIV data reveal the vortical structure near impingement. When the thermal impinges upon the stratified interface, a baroclinic eddy generated at the interface appears to merge with eddies comprising the thermal itself to form a vortex ring. This ring remains near the interface, moving mainly along the lateral or horizontal direction away from the region of impingement. These results suggest that lateral transport is significant for thermals impinging on stratified interfaces, and that ignoring such transport may greatly underestimate overall transport and mixing in such flows.

  15. Dual Spark Plugs For Stratified-Charge Rotary Engine

    NASA Technical Reports Server (NTRS)

    Abraham, John; Bracco, Frediano V.

    1996-01-01

    Fuel efficiency of stratified-charge, rotary, internal-combustion engine increased by improved design featuring dual spark plugs. Second spark plug ignites fuel on upstream side of main fuel injector; enabling faster burning and more nearly complete utilization of fuel.

  16. Gravity-induced stresses in stratified rock masses

    USGS Publications Warehouse

    Amadei, B.; Swolfs, H.S.; Savage, W.Z.

    1988-01-01

    This paper presents closed-form solutions for the stress field induced by gravity in anisotropic and stratified rock masses. These rocks are assumed to be laterally restrained. The rock mass consists of finite mechanical units, each unit being modeled as a homogeneous, transversely isotropic or isotropic linearly elastic material. The following results are found. The nature of the gravity induced stress field in a stratified rock mass depends on the elastic properties of each rock unit and how these properties vary with depth. It is thermodynamically admissible for the induced horizontal stress component in a given stratified rock mass to exceed the vertical stress component in certain units and to be smaller in other units; this is not possible for the classical unstratified isotropic solution. Examples are presented to explore the nature of the gravity induced stress field in stratified rock masses. It is found that a decrease in rock mass anisotropy and a stiffening of rock masses with depth can generate stress distributions comparable to empirical hyperbolic distributions previously proposed in the literature. ?? 1988 Springer-Verlag.

  17. HYDRODYNAMIC AND TRANSPORT MODELING STUDY IN A HIGHLY STRATIFIED ESTUARY

    EPA Science Inventory

    This paper presents the preliminary results of hydrodynamic and salinity predictions and the implications to an ongoing contaminated sediment transport and fate modeling effort in the Lower Duwamish Waterway (LDW), Seattle, Washington. The LDW is highly strati-fied when freshwate...

  18. Nitrogen and carbon uptake dynamics in Lake Superior

    NASA Astrophysics Data System (ADS)

    Kumar, Sanjeev; Sterner, Robert W.; Finlay, Jacques C.

    2008-12-01

    Despite a fivefold rise in nitrate concentration over the last century, many fundamental aspects of Lake Superior's N and C cycles are still very poorly understood. We present here the first measurements of inorganic N uptake and in situ C uptake rates in Lake Superior, one of the largest lakes in the world. A profile of C uptake suggests that more than 95% of production occurs in the top 30 m with highest productivity to biomass ratio in the epilimnion. High C uptake:N uptake and particulate C: N ratio compared to the Redfield ratio (6.6) in the epilimnion suggests higher turnover rate of C compared to N in epilimnetic particles. Experiments performed over a range of typical environmental conditions suggest a strong temperature dependence of N uptake with maximum rates observed during the warmest stratified period. Lakewide N uptake estimates derived from a temperature-based model suggest that on an annual basis, uptake is considerably higher than total N inputs from outside the lake. This difference indicates that the lake is recycling N rapidly, leading to a shorter turnover time in the water column than previously assumed. The long-term buildup of nitrate in the lake has been hypothesized to arise from limited assimilation of nitrate entering the lake. In contrast, our results suggest that nitrate accumulating in the lake is a result of internal N cycling, a finding consistent with recent studies based on a nitrogen budget and NO3- stable isotope analyses.

  19. Great Lakes

    USGS Publications Warehouse

    Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

    1998-01-01

    The wild plants and animals and the natural systems that support them in the Great Lakes region are valuable resources of considerable local, regional, and national interest. They are also, in part, transboundary resources that the U.S. shares with its Canadian neighbors to the north. The way these resources are changing over time is inadequately known and is a concern for resource users and for those charged with managing and protecting these unique and valuable resources. This chapter describes the wild plants and animals and the systems that support them in the Great Lakes region; addresses their condition; and points out the gaps in our knowledge about them that, if filled, would aid in their conservation and appropriate use.

  20. Numerical analysis of internal waves in stratified wake flows

    NASA Astrophysics Data System (ADS)

    Fraunie, Philppe

    2014-05-01

    In laboratory investigations, increased attention has been given to internal waves generated by stationary placed oscillating sources and moving bodies in stratified fluids [1]. The main attention was paid to study flows past bodies of perfect shapes like sphere [2], cylinder [3] of thin strip [3] which are the best theoretical (analytical or numerical) studies. Due to simplicity of geometry, flow around a strip has a potential to investigate separately effects of a drag and lift forces on the body by changing the slope of the horizontally moving strip which can be placed vertically [1], horizontally [2], or be tilted under some angle to the direction of towing velocity [5]. Numeric modeling of a flow past vertical strip uniformly towing with permanent velocity in horizontal direction in a linearly stratified talk which was based on a finite differences solver adapted to the low Reynolds Navier-Stokes equation with transport equation for salinity (LES simulation [6] and RANS [7]) has demonstrated reasonable agreement with data of Schlieren visualization, density marker and probe measurements of internal wave fields. The chosen test cases allowed demonstrating the ability of selected numerical methods to represent stably stratified flows over horizontal strip [4] and hill type 2D obstacles [1, 3] with generation of internal waves. ACKNOWLEDGMENTS This research work was supported by the Region Provence Alpes Côte d'Azur - Modtercom project. The work was also supported by the Russian Foundation for Basic Research (grant 12-01-00128). REFERENCES [1] Chashechkin Yu.D., Mitkin V.V. Experimental study of a fine structure of 2D wakes and mixing past an obstacle in a continuously stratified fluid // Dynamics of Atmosphere and Oceans. 2001. V. 34. P. 165-187. [2] Chashechkin, Yu. D. Hydrodynamics of a sphere in a stratified fluid // Fluid Dyn. 1989. V.24(1) P. 1-7. [3] Mitkin V. V., Chashechkin Yu. D. Transformation of hanging discontinuities into vortex systems in a

  1. Is surgery the gold standard in the treatment of obstructive hypertrophic cardiomyopathy?

    PubMed Central

    Knyshov, Gennady; Lazoryshynets, Vasyl; Rudenko, Kostyantyn; Kravchuk, Borys; Beshlyaga, Vyacheslav; Zalevsky, Valery; Rasputnyak, Olga; Batsak, Bogdan

    2013-01-01

    OBJECTIVES Hypertrophic cardiomyopathy is a complex and relatively common genetic cardiac disease and has been the subject of intensive scrutiny and investigation for over 40 years. The aim of this non-randomized cohort study was to compare subjective and objective outcomes in hypertrophic cardiomyopathy patients undergoing drug therapy, surgical myotomy-myectomy, dual-chamber pacing and alcohol septal ablation. METHODS We examined 194 patients: 103 with non-obstructive hypertrophic cardiomyopathy and 91 with obstructive hypertrophic cardiomyopathy. All the patients with a non-obstructive form were on drug therapy. Ninety-one consecutive patients with drug-refractory obstructive hypertrophic cardiomyopathy were treated invasively. Dual-chamber pacemaker implantation was performed for 49 patients with previous positive temporary pacing test (Group 1). In 28 patients with massive left ventricle hypertrophy and obliteration of its cavities, extensive myotomy-myectomy was performed (Group 2). In 14 patients with midventricular obstruction and appropriate coronary anatomy, alcohol septal ablation was performed (Group 3). RESULTS The peak left ventricle outflow tract gradient was 84.1 ± 15.2 mmHg in Group 1, 113.3 ± 14.9 mmHg in Group 2 and 97.5 ± 8.9 mmHg in Group 3. Dual-chamber pacing in Group 1 with optimal atrio-ventricular delay (85–180 ms for atrium pacing and 45–120 ms for atrial sensing) leads to dramatic decreases in left ventricle outflow tract gradient to 17.6 ± 11.8 mmHg and degree of mitral regurgitation. After extensive myectomy in Group 2, we observed a reduction of left ventricle outflow tract gradient to 17.3 ± 10.2 mmHg. Septal alcohol ablation in Group 3 leads to a left ventricle outflow tract gradient decrease from 97.5 ± 8.9 to 25.3 ± 5.8 mmHg. CONCLUSIONS Surgical myectomy, dual-chamber pacing and alcohol septal ablation are equally effective in reducing obstruction in case of correct indications. Dual-chamber pacing is indicated in

  2. The effect of transparency on stratification and mixing regime in lakes

    NASA Astrophysics Data System (ADS)

    Shatwell, Tom; Adrian, Rita; Kirillin, Georgiy

    2016-04-01

    The mixing regime is fundamentally important to lake ecology. Whereas shallow lakes mix to the bottom regularly, deep lakes tend to stratify seasonally. Water transparency strongly affects stratification duration and the mixing regime of lakes of intermediate depth. We review our recent research on how water transparency affects stratification duration and mixing regime in lakes. Firstly we derive physical scaling for the critical depth at which lakes switch from polymixis to seasonal stratification based on the radiation balance, the wind speed, water transparency and lake length. This scaling relation showed that the critical depth varies almost linearly with Secchi depth (transparency) and successfully classified the mixing regime of over 80% of the 379 lakes in our dataset. Secondly we investigated how seasonal variation in transparency due to phytoplankton affects stratification and mixing by analysing long term lake data and performing simulations with a hydrodynamic model. Here we found that the spring clear water phase, which is caused when zooplankton graze the spring phytoplankton bloom, can strongly influence stratification duration and sometimes also the mixing regime. Finally using model simulations of climate scenarios, we show how global warming and a change in transparency can potentially affect lake mixing regimes. Polymictic - dimictic regime shifts were more sensitive to transparency than warming, whereas dimictic - monomictic regime shifts were more sensitive to warming than transparency. Transparency has the strongest effect on stratification in clear lakes between 4 and 10 m deep. Changes in transparency due to biotic interactions or anthropogenic impact may lead to mixing regime shifts in these lakes.

  3. Nutrient additions by waterfowl to lakes and reservoirs: predicting their effects on productivity and water quality

    USGS Publications Warehouse

    Manny, Bruce A.; Johnson, W.C.; Wetzel, R.G.

    1994-01-01

    Lakes and reservoirs provide water for human needs and habitat for aquatic birds. Managers of such waters may ask whether nutrients added by waterfowl degrade water quality. For lakes and reservoirs where primary productivity is limited by phosphorus (P), we developed a procedure that integrates annual P loads from waterfowl and other external sources, applies a nutrient load-response model, and determines whether waterfowl that used the lake or reservoir degraded water quality. Annual P loading by waterfowl can be derived from a figure in this report, using the days per year that each kind spent on any lake or reservoir. In our example, over 6500 Canada geese (Branta canadensis) and 4200 ducks (mostly mallards, Anas platyrhynchos) added 4462 kg of carbon (C), 280 kg of nitrogen (N), and 88 kg of P y-1 to Wintergreen Lake in southwestern Michigan, mostly during their migration. These amounts were 69% of all C, 27% of all N, and 70% of all P that entered the lake from external sources. Loads from all external sources totaled 840 mg P m-2 y-1. Application of a nutrient load-response model to this concentration, the hydraulic load (0.25 m y-1), and the water residence time (9.7 y) of Wintergreen Lake yielded an average annual concentration of total P in the lake of 818 mg m-3 that classified the lake as hypertrophic. This trophic classification agreed with independent measures of primary productivity, chlorophyll-a, total P, total N, and Secchi disk transparency made in Wintergreen Lake. Our procedure showed that waterfowl caused low water quality in Wintergreen Lake.

  4. Biological and Chemical Removal of Primary Cilia Affects Mechanical Activation of Chondrogenesis Markers in Chondroprogenitors and Hypertrophic Chondrocytes

    PubMed Central

    Deren, Matthew E.; Yang, Xu; Guan, Yingjie; Chen, Qian

    2016-01-01

    Chondroprogenitors and hypertrophic chondrocytes, which are the first and last stages of the chondrocyte differentiation process, respectively, are sensitive to mechanical signals. We hypothesize that the mechanical sensitivity of these cells depends on the cell surface primary cilia. To test this hypothesis, we removed the primary cilia by biological means with transfection with intraflagellar transport protein 88 (IFT88) siRNA or by chemical means with chloral hydrate treatment. Transfection of IFT88 siRNA significantly reduced the percentage of ciliated cells in both chondroprogenitor ATDC5 cells as well as primary hypertrophic chondrocytes. Cyclic loading (1 Hz, 10% matrix deformation) of ATDC5 cells in three-dimensional (3D) culture stimulates the mRNA levels of chondrogenesis marker Type II collagen (Col II), hypertrophic chondrocyte marker Type X collagen (Col X), and a molecular regulator of chondrogenesis and chondrocyte hypertrophy bone morphogenetic protein 2 (BMP-2). The reduction of ciliated chondroprogenitors abolishes mechanical stimulation of Col II, Col X, and BMP-2. In contrast, cyclic loading stimulates Col X mRNA levels in hypertrophic chondrocytes, but not those of Col II and BMP-2. Both biological and chemical reduction of ciliated hypertrophic chondrocytes reduced but failed to abolish mechanical stimulation of Col X mRNA levels. Thus, primary cilia play a major role in mechanical stimulation of chondrogenesis and chondrocyte hypertrophy in chondroprogenitor cells and at least a partial role in hypertrophic chondrocytes. PMID:26861287

  5. GPR Profiles of Stratified Deposits in Eastern Taylor Valley, Antarctica: Permafrost Periglacial or Glacial?

    NASA Astrophysics Data System (ADS)

    Arcone, S. A.; Prentice, M. L.

    2012-12-01

    In the Antarctic Dry Valleys, what might seem to be a permafrost periglacial feature such as a moraine, may actually be a dirt-rich or dirt-covered glacial structure. We discuss ground-penetrating radar (GPR) profiles we recorded along transects over the deeply frozen deposits of Hjorth Hill in Eastern Taylor Valley, Antarctica, overlooking the Ross Sea. The dirt-covered surface, uneven topography, and proximity to the nearby Wilson Piedmont Glacier and to the long receded Ross Sea Ice Sheet (RSIS), suggest the confluence of several glacial moraines and therefore, a permafrost feature. A few borehole logs up to 14 m depth reveal the nature and age of a few important horizons. Instead of a more random and partially or unstratified morainal structure, our 100 and 200 MHz profiles are well stratified, the major events of which are piece-wise continuous layers of ice 1-2 m thick and extending at least hundreds of meters. Bubbles within some of this ice suggest a lake-type origin. Although one log shows that a 9 m layer between these ice horizons is only about 22 percent ice by volume and not visibly stratified, thereby making this layer appear as an embedded permafrost feature, in the profiles the layers often appear relatively transparent, which suggests greater ice content at other locations and a glacial origin. In addition, and stratification within some of the ice within the cores appears basal (glacial) in origin. The relative dielectric permittivity for the whole section is near 5, as expected for ice and felsic mineralogy. Most C14 dates within the core range from 10000-12000 years BP. Wavelet phase structures suggest that the long horizons deeper than the cores are also responses to ice layers and that they are less thick than the insitu wavelength of about 2 m. The more detailed 400 MHz profiles show that material within 10 m of the surface appears be mainly ice with suspended clasts. Maximum penetration achieved within our time range was about 45 m within

  6. Relation of strain by feature tracking and clinical outcome in children, adolescents, and young adults with hypertrophic cardiomyopathy.

    PubMed

    Smith, Brandon M; Dorfman, Adam L; Yu, Sunkyung; Russell, Mark W; Agarwal, Prachi P; Ghadimi Mahani, Maryam; Lu, Jimmy C

    2014-10-15

    Evaluation of hypertrophic cardiomyopathy (HC) in young patients is limited by lack of age-specific norms for wall thickness on cardiovascular magnetic resonance (CMR) images. Left ventricular strain may have a role in identifying and risk stratifying patients with HC, but few data exist for strain measurement on CMR images. In 30 patients (14.1 ± 3.2 years) with clinically diagnosed HC and 24 controls (15.6 ± 2.8 years), strain (radial, longitudinal, and circumferential) was evaluated by 2 experienced readers using CMR feature tracking. In patients with HC, hypertrophied segments had decreased radial (28.0 ± 5.2% vs 58.6 ± 3.9%, p = 0.0002), circumferential (-23.7 ± 1.1% vs -28.3 ± 0.8%, p = 0.004), and longitudinal (-11.2 ± 1.2% vs -21.7 ± 0.8%, p <0.0001) strains versus control segments. Hypertrophied segments had decreased longitudinal (basal segments -12.2 ± 1.9% vs -22.6 ± 1.2%, p = 0.0002), radial (basal segments 22.7 ± 10.8% vs 78.8 ± 7.2%, p = 0.0001), and circumferential (basal segments -22.4 ± 1.7% vs -30.6 ± 1%, p = 0.0004) strains versus nonhypertrophied segments in patients with HC. Longitudinal strain had the lowest intraobserver and interobserver variabilities (coefficient of variability -15.7% and -18.5%). After a median follow-up of 28.1 months (interquartile range [IQR] 4.2 to 33.1), 7 patients with HC with an adverse event outcome (5 ventricular tachycardia, 1 appropriate implantable cardioverter-defibrillator discharge, and 1 death) had reduced global radial (median 39.7%, IQR 39.6% to 46.6% vs 65.4%, IQR 46.1% to 83.4%, p = 0.01) and longitudinal strains (median -16.5%, IQR -18.7% to -15.5% vs -19.7%, IQR -23.8% to -17.5%, p = 0.046) compared with patients with HC without an event. In conclusion, CMR feature tracking detects differences in global and segmental strains and may represent a novel method to predict clinical outcome in patients with HC. Further study is necessary to evaluate longitudinal changes in this population.

  7. Up-to-date approach to manage keloids and hypertrophic scars: a useful guide.

    PubMed

    Arno, Anna I; Gauglitz, Gerd G; Barret, Juan P; Jeschke, Marc G

    2014-11-01

    Keloids and hypertrophic scars occur anywhere from 30 to 90% of patients, and are characterized by pathologically excessive dermal fibrosis and aberrant wound healing. Both entities have different clinical and histochemical characteristics, and unfortunately still represent a great challenge for clinicians due to lack of efficacious treatments. Current advances in molecular biology and genetics reveal new preventive and therapeutical options which represent a hope to manage this highly prevalent, chronic and disabling problem, with long-term beneficial outcomes and improvement of quality of life. While we wait for these translational clinical products to be marketed, however, it is imperative to know the basics of the currently existing wide array of strategies to deal with excessive scars: from the classical corticotherapy, to the most recent botulinum toxin and lasers. The main aim of this review paper is to offer a useful up-to-date guideline to prevent and treat keloids and hypertrophic scars.

  8. [Non-pharmacological treatment of hypertrophic obstructive cardiomyopathy guided by echocardiography].

    PubMed

    La Canna, Giovanni; Montorfano, Matteo; Ficarra, Eleonora; Michev, Iassen; Capritti, Elvia; Grimaldi, Antonio; De Cobelli, Francesco; Verzini, Alessandro; Colombo, Antonio; Alfieri, Ottavio

    2006-03-01

    As a relevant cause of symptoms and adverse clinical prognosis, left ventricular obstruction should be regarded as an important therapeutic target in patients with hypertrophic obstructive cardiomyopathy. The surgical approach (including septal myectomy or mitral valve surgery) and percutaneous transluminal septal myocardial ablation offer a non-pharmacological option for the treatment of symptomatic left ventricular obstruction and symptoms unresponsive to medical treatment. The surgical approach is established as an effective strategy for relieving symptoms from dynamic obstruction. Percutaneous septal ablation, on the other hand, has only recently been introduced into clinical practice and, despite its efficacy as an obstructive abolisher, little is known about the prognostic long-term impact of procedural-induced myocardial damage. Due to its accuracy and diagnostic versatility, including intraprocedural use, Doppler echocardiography provides essential information for the planning and monitoring of non-pharmacological therapy in patients with hypertrophic obstructive cardiomyopathy.

  9. A small-molecule inhibitor of sarcomere contractility suppresses hypertrophic cardiomyopathy in mice

    PubMed Central

    Green, Eric M.; Wakimoto, Hiroko; Anderson, Robert L.; Evanchik, Marc J.; Gorham, Joshua M.; Harrison, Brooke C.; Henze, Marcus; Kawas, Raja; Oslob, Johan D.; Rodriguez, Hector M.; Song, Yonghong; Wan, William; Leinwand, Leslie A.; Spudich, James A.; McDowell, Robert S.; Seidman, J. G.; Seidman, Christine E.

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is an inherited disease of heart muscle that can be caused by mutations in sarcomere proteins. Clinical diagnosis depends on an abnormal thickening of the heart, but the earliest signs of disease are hyperdynamic contraction and impaired relaxation. Whereas some in vitro studies of power generation by mutant and wild-type sarcomere proteins are consistent with mutant sarcomeres exhibiting enhanced contractile power, others are not. We identified a small molecule, MYK-461, that reduces contractility by decreasing the adenosine triphosphatase activity of the cardiac myosin heavy chain. Here we demonstrate that early, chronic administration of MYK-461 suppresses the development of ventricular hypertrophy, cardiomyocyte disarray, and myocardial fibrosis and attenuates hypertrophic and profibrotic gene expression in mice harboring heterozygous human mutations in the myosin heavy chain. These data indicate that hyperdynamic contraction is essential for HCM pathobiology and that inhibitors of sarcomere contraction may be a valuable therapeutic approach for HCM. PMID:26912705

  10. An autopsy report of acute myocardial infarction with hypertrophic obstructive cardiomyopathy-like heart.

    PubMed

    Ushikoshi, Hiroaki; Okada, Hideshi; Morishita, Kentaro; Imai, Hajime; Tomita, Hiroyuki; Nawa, Takahide; Suzuki, Kodai; Ikeshoji, Haruka; Kato, Hisaaki; Yoshida, Takahiro; Yoshida, Shozo; Shirai, Kunihiro; Toyoda, Izumi; Hara, Akira; Ogura, Shinji

    2015-01-01

    An 84-year-old woman, who was followed up as hypertrophic obstructive cardiomyopathy (HOCM) in a local hospital, was transferred to our center because of anterior chest pain and diagnosed with acute myocardial infarction (MI). Coronary angiography showed total occlusion of the mid-left anterior descending, and flow was restored after endovascular thrombectomy. An autopsy was performed after she died on hospital day 6. At autopsy, there was no significant stenosis in this vessel and the absence of plaque rupture was confirmed. Likewise, it was unclear asymmetric hypertrophy at autopsy, it could not deny that a sigmoid deformity of the basal septum occurs in elderly patients and can mimic the asymmetric septal hypertrophy of hypertrophic cardiomyopathy. MI was thought to be caused by coronary spasm or squeezing in HOCM-like heart. Therefore, it may be necessary antithrombosis therapy in HOCM-like patients with no history of paroxysmal atrial fibrillation.

  11. Myocardial stunning in hypertrophic cardiomyopathy: recovery predicted by single photon emission computed tomographic thallium-201 scintigraphy

    SciTech Connect

    Fine, D.G.; Clements, I.P.; Callahan, M.J.

    1989-05-01

    A young woman with hypertrophic cardiomyopathy confirmed by echocardiography and cardiac catheterization presented with chest pain and features of a large left ventricular aneurysm. The initial diagnosis was myocardial ischemia with either an evolving or an ancient myocardial infarction. Subsequently, verapamil therapy was associated with complete resolution of the extensive left ventricular wall motion abnormalities, normalization of left ventricular ejection fraction and a minimal myocardial infarction. Normal thallium uptake on single photon emission computed tomographic scintigraphy early in the hospital course predicted myocardial viability in the region of the aneurysm. Thus, orally administered verapamil may reverse spontaneous extensive myocardial ischemia in hypertrophic cardiomyopathy and possibly limit the extent of myocardial infarction in such circumstances.

  12. Left Atrial trajectory impairment in Hypertrophic Cardiomyopathy disclosed by Geometric Morphometrics and Parallel Transport

    PubMed Central

    Piras, Paolo; Torromeo, Concetta; Re, Federica; Evangelista, Antonietta; Gabriele, Stefano; Esposito, Giuseppe; Nardinocchi, Paola; Teresi, Luciano; Madeo, Andrea; Chialastri, Claudia; Schiariti, Michele; Varano, Valerio; Uguccioni, Massimo; Puddu, Paolo E.

    2016-01-01

    The analysis of full Left Atrium (LA) deformation and whole LA deformational trajectory in time has been poorly investigated and, to the best of our knowledge, seldom discussed in patients with Hypertrophic Cardiomyopathy. Therefore, we considered 22 patients with Hypertrophic Cardiomyopathy (HCM) and 46 healthy subjects, investigated them by three–dimensional Speckle Tracking Echocardiography, and studied the derived landmark clouds via Geometric Morphometrics with Parallel Transport. Trajectory shape and trajectory size were different in Controls versus HCM and their classification powers had high AUC (Area Under the Receiving Operator Characteristic Curve) and accuracy. The two trajectories were much different at the transition between LA conduit and booster pump functions. Full shape and deformation analyses with trajectory analysis enabled a straightforward perception of pathophysiological consequences of HCM condition on LA functioning. It might be worthwhile to apply these techniques to look for novel pathophysiological approaches that may better define atrio–ventricular interaction. PMID:27713503

  13. Microvascular permeability changes might explain cardiac tamponade after alcohol septal ablation for hypertrophic cardiomyopathy.

    PubMed

    Hsu, Jen-Te; Hsiao, Ju-Feng; Chang, Jung-Jung; Chung, Chang-Min; Chang, Shih-Tai; Pan, Kuo-Li

    2014-04-01

    Various sequelae of alcohol septal ablation for hypertrophic obstructive cardiomyopathy have been reported. Of note, some cases of cardiac tamponade after alcohol septal ablation cannot be well explained. We describe the case of a 78-year-old woman with hypertrophic obstructive cardiomyopathy in whom cardiac tamponade developed one hour after alcohol septal ablation, probably unrelated to mechanical trauma. At that time, we noted a substantial difference in the red blood cell-to-white blood cell ratio between the pericardial effusion (1,957.4) and the peripheral blood (728.3). In addition to presenting the patient's case, we speculate that a possible mechanism for acute tamponade--alcohol-induced changes in microvascular permeability--is a reasonable explanation for cases of alcohol septal ablation that are complicated by otherwise-unexplainable massive pericardial effusions. PMID:24808788

  14. [Amelioration of secondary hypertrophic osteoarthropathy following tumor resection in a patient with primary lung cancer].

    PubMed

    Akizuki, M; Homma, M

    1991-06-01

    A 41 year-old female presented with swelling of lower extremities and polyarthralgia involving both knee joints. Physical examination revealed presence of finger clubbing, tenderness and pain-on-motion in knee and foot joints. A chest X-ray film showed a solitary tumor in the right mid-lung field. There were subperiosteal new bone formation and radioisotope accumulation in the legs bilaterally. The clubbing, periostitis and arthritis confirmed a diagnosis of hypertrophic osteoarthropathy. Adenocarcinoma was the biopsy diagnosis of the lung tumor. The characteristic features of hypertrophic osteoarthropathy resolved after surgical resection of the pulmonary lesion followed by chemotherapy. This case demonstrates a typical example of identification of a treatable malignant condition by rheumatic symptoms.

  15. Left Atrial trajectory impairment in Hypertrophic Cardiomyopathy disclosed by Geometric Morphometrics and Parallel Transport

    NASA Astrophysics Data System (ADS)

    Piras, Paolo; Torromeo, Concetta; Re, Federica; Evangelista, Antonietta; Gabriele, Stefano; Esposito, Giuseppe; Nardinocchi, Paola; Teresi, Luciano; Madeo, Andrea; Chialastri, Claudia; Schiariti, Michele; Varano, Valerio; Uguccioni, Massimo; Puddu, Paolo E.

    2016-10-01

    The analysis of full Left Atrium (LA) deformation and whole LA deformational trajectory in time has been poorly investigated and, to the best of our knowledge, seldom discussed in patients with Hypertrophic Cardiomyopathy. Therefore, we considered 22 patients with Hypertrophic Cardiomyopathy (HCM) and 46 healthy subjects, investigated them by three–dimensional Speckle Tracking Echocardiography, and studied the derived landmark clouds via Geometric Morphometrics with Parallel Transport. Trajectory shape and trajectory size were different in Controls versus HCM and their classification powers had high AUC (Area Under the Receiving Operator Characteristic Curve) and accuracy. The two trajectories were much different at the transition between LA conduit and booster pump functions. Full shape and deformation analyses with trajectory analysis enabled a straightforward perception of pathophysiological consequences of HCM condition on LA functioning. It might be worthwhile to apply these techniques to look for novel pathophysiological approaches that may better define atrio–ventricular interaction.

  16. Microvascular Permeability Changes Might Explain Cardiac Tamponade after Alcohol Septal Ablation for Hypertrophic Cardiomyopathy

    PubMed Central

    Hsu, Jen-Te; Hsiao, Ju-Feng; Chang, Jung-Jung; Chung, Chang-Min; Chang, Shih-Tai; Pan, Kuo-Li

    2014-01-01

    Various sequelae of alcohol septal ablation for hypertrophic obstructive cardiomyopathy have been reported. Of note, some cases of cardiac tamponade after alcohol septal ablation cannot be well explained. We describe the case of a 78-year-old woman with hypertrophic obstructive cardiomyopathy in whom cardiac tamponade developed one hour after alcohol septal ablation, probably unrelated to mechanical trauma. At that time, we noted a substantial difference in the red blood cell-to-white blood cell ratio between the pericardial effusion (1,957.4) and the peripheral blood (728.3). In addition to presenting the patient's case, we speculate that a possible mechanism for acute tamponade—alcohol-induced changes in microvascular permeability—is a reasonable explanation for cases of alcohol septal ablation that are complicated by otherwise-unexplainable massive pericardial effusions. PMID:24808788

  17. Hypertrophic Cardiomyopathy (HCM): How Flow Analysis May Drive Medical Management and Surgical Approach

    NASA Astrophysics Data System (ADS)

    Abraham, Theodore P.

    2011-11-01

    Hypertrophic Cardiomyopathy (HCM) is the most common inherited heart disease and occurs in 1 in 500 persons worldwide regardless of race, age and gender. It is the most common cause of sudden death in the young and also causes heart failure and cardiac arrhythmias. The primary anatomic abnormality is thickening of certain walls, or sometimes global thickening of the left or right ventricle. The patterns of thickening along with increased ventricular stiffness lead to suboptimal ventricular filling and inefficient ejection of blood from the ventricle. Treatment for HCM can be medical or surgical. The choice of therapy is driven by the presence and severity of outflow obstruction. Flow analysis could provide sophisticated information about outflow and inflow ventricular dynamics. These flow dynamics features may enable better medical choices and provide information that would allow superior surgical planning. Associate Professor of Medicine & Director, Hypertrophic Cardiomyopathy Clinic

  18. Classifying Lakes to Quantify Relationships Between Epilimnetic Chlorophyll a and Hypoxia

    NASA Astrophysics Data System (ADS)

    Yuan, Lester L.; Pollard, Amina I.

    2015-03-01

    Excess nutrient loading increases algal abundance which can cause hypoxia in many lakes and reservoirs. We used a divisive partitioning approach to analyze dissolved oxygen profile data collected across the continental United States to increase the precision of estimated relationships between chlorophyll a (chl a) concentrations and the extent of hypoxia in the water column. Chl a concentrations predicted the extent of hypoxia most accurately in lakes that were stratified at the time of sampling with a maximum temperature gradient of at least 1.2 °C/m. Lake elevation, Secchi depth, and lake geometry ratio further refined the specification of groups of lakes with different relationships between chl a and the extent of hypoxia. The statistical relationships between chl a and the extent of hypoxia that were estimated can be used directly for setting management thresholds for chl a in particular types of lakes.

  19. Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica.

    PubMed

    Herbei, Radu; Rytel, Alexander L; Lyons, W Berry; McKnight, Diane M; Jaros, Christopher; Gooseff, Michael N; Priscu, John C

    2016-01-01

    The McMurdo Dry Valleys constitute the largest ice free area of Antarctica. The area is a polar desert with an annual precipitation of ∼ 3 cm water equivalent, but contains several lakes fed by glacial melt water streams that flow from four to twelve weeks of the year. Over the past ∼20 years, data have been collected on the lakes located in Taylor Valley, Antarctica as part of the McMurdo Dry Valley Long-Term Ecological Research program (MCM-LTER). This work aims to understand the impact of climate variations on the biological processes in all the ecosystem types within Taylor Valley, including the lakes. These lakes are stratified, closed-basin systems and are perennially covered with ice. Each lake contains a variety of planktonic and benthic algae that require nutrients for photosynthesis and growth. The work presented here focuses on Lake Fryxell, one of the three main lakes of Taylor Valley; it is fed by thirteen melt-water streams. We use a functional regression approach to link the physical, chemical, and biological processes within the stream-lake system to evaluate the input of water and nutrients on the biological processes in the lakes. The technique has been shown previously to provide important insights into these Antarctic lacustrine systems where data acquisition is not temporally coherent. We use data on primary production (PPR) and chlorophyll-A (CHL)from Lake Fryxell as well as discharge observations from two streams flowing into the lake. Our findings show an association between both PPR, CHL and stream input. PMID:27441705

  20. Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica

    PubMed Central

    Rytel, Alexander L.; Lyons, W. Berry; McKnight, Diane M.; Jaros, Christopher; Gooseff, Michael N.; Priscu, John C.

    2016-01-01

    The McMurdo Dry Valleys constitute the largest ice free area of Antarctica. The area is a polar desert with an annual precipitation of ∼ 3 cm water equivalent, but contains several lakes fed by glacial melt water streams that flow from four to twelve weeks of the year. Over the past ∼20 years, data have been collected on the lakes located in Taylor Valley, Antarctica as part of the McMurdo Dry Valley Long-Term Ecological Research program (MCM-LTER). This work aims to understand the impact of climate variations on the biological processes in all the ecosystem types within Taylor Valley, including the lakes. These lakes are stratified, closed-basin systems and are perennially covered with ice. Each lake contains a variety of planktonic and benthic algae that require nutrients for photosynthesis and growth. The work presented here focuses on Lake Fryxell, one of the three main lakes of Taylor Valley; it is fed by thirteen melt-water streams. We use a functional regression approach to link the physical, chemical, and biological processes within the stream-lake system to evaluate the input of water and nutrients on the biological processes in the lakes. The technique has been shown previously to provide important insights into these Antarctic lacustrine systems where data acquisition is not temporally coherent. We use data on primary production (PPR) and chlorophyll-A (CHL)from Lake Fryxell as well as discharge observations from two streams flowing into the lake. Our findings show an association between both PPR, CHL and stream input. PMID:27441705

  1. Hydrological Controls on Ecosystem Dynamics in Lake Fryxell, Antarctica.

    PubMed

    Herbei, Radu; Rytel, Alexander L; Lyons, W Berry; McKnight, Diane M; Jaros, Christopher; Gooseff, Michael N; Priscu, John C

    2016-01-01

    The McMurdo Dry Valleys constitute the largest ice free area of Antarctica. The area is a polar desert with an annual precipitation of ∼ 3 cm water equivalent, but contains several lakes fed by glacial melt water streams that flow from four to twelve weeks of the year. Over the past ∼20 years, data have been collected on the lakes located in Taylor Valley, Antarctica as part of the McMurdo Dry Valley Long-Term Ecological Research program (MCM-LTER). This work aims to understand the impact of climate variations on the biological processes in all the ecosystem types within Taylor Valley, including the lakes. These lakes are stratified, closed-basin systems and are perennially covered with ice. Each lake contains a variety of planktonic and benthic algae that require nutrients for photosynthesis and growth. The work presented here focuses on Lake Fryxell, one of the three main lakes of Taylor Valley; it is fed by thirteen melt-water streams. We use a functional regression approach to link the physical, chemical, and biological processes within the stream-lake system to evaluate the input of water and nutrients on the biological processes in the lakes. The technique has been shown previously to provide important insights into these Antarctic lacustrine systems where data acquisition is not temporally coherent. We use data on primary production (PPR) and chlorophyll-A (CHL)from Lake Fryxell as well as discharge observations from two streams flowing into the lake. Our findings show an association between both PPR, CHL and stream input.

  2. A numerical study of laminar flames propagating in stratified mixtures

    NASA Astrophysics Data System (ADS)

    Zhang, Jiacheng

    Numerical simulations are carried out to study the structure and speed of laminar flames propagating in compositionally and thermally stratified fuel-air mixtures. The study is motivated by the need to understand the physics of flame propagation in stratified-charge engines and model it. The specific question of interest in this work is: how does the structure and speed of the flame in the stratified mixture differ from that of the flame in a corresponding homogeneous mixture at the same equivalence ratio, temperature, and pressure? The studies are carried out in hydrogen-air, methane-air, and n-heptane-air mixtures. A 30-species 184-step skeletal mechanism is employed for methane oxidation, a 9-species 21-step mechanism for hydrogen oxidation, and a 37-species 56-step skeletal mechanism for n-heptane oxidation. Flame speed and structure are compared with corresponding values for homogeneous mixtures. For compositionally stratified mixtures, as shown in prior experimental work, the numerical results suggest that when the flame propagates from a richer mixture to a leaner mixture, the flame speed is faster than the corresponding speed in the homogeneous mixture. This is caused by enhanced diffusion of heat and species from the richer mixture to the leaner mixture. In fact, the effects become more pronounced in leaner mixtures. Not surprisingly, the stratification gradient influences the results with shallower gradients showing less effect. The controlling role that diffusion plays is further assessed and confirmed by studying the effect of a unity Lewis number assumption in the hydrogen/air mixtures. Furthermore, the effect of stratification becomes less important when using methane or n-heptane as fuel. The laminar flame speed in a thermally stratified mixture is similar to the laminar flame speed in homogeneous mixture at corresponding unburned temperature. Theoretical analysis is performed and the ratio of extra thermal diffusion rate to flame heat release rate

  3. Determination of water retention in stratified porous materials

    USGS Publications Warehouse

    Constantz, J.

    1995-01-01

    Predicted and measured water-retention values, ??(??), were compared for repacked, stratified core samples consisting of either a sand with a stone-bearing layer or a sand with a clay loam layer in various spatial orientations. Stratified core samples were packed in submersible pressure outflow cells, then water-retention measurements were performed between matric potentials, ??, of 0 to -100 kPa. Predictions of ??(??) were based on a simple volume-averaging model using estimates of the relative fraction and ??(??) values of each textural component within a stratified sample. In general, predicted ??(??) curves resembled measured curves well, except at higher saturations in a sample consisting of a clay loam layer over a sand layer. In this case, the model averaged the air-entry of both materials, while the air-entry of the sample was controlled by the clay loam in contact with the cell's air-pressure inlet. In situ, avenues for air-entry generally exist around clay layers, so that the model should adequately predict air-entry for stratified formations regardless of spatial orientation of fine versus coarse layers. Agreement between measured and predicted volumetric water contents, ??, was variable though encouraging, with mean differences between measured and predicted ?? values in the range of 10%. Differences in ?? of this magnitude are expected due to variability in pore structure between samples, and do not indicate inherent problems with the volume averaging model. This suggets that explicit modeling of stratified formations through detailed characterization of the stratigraphy has the potential of yielding accurate ??(??) values. However, hydraulic-equilibration times were distinctly different for each variation in spatial orientation of textural layering, indicating that transient behavior during drainage in stratified formations is highly sensitive to the stratigraphic sequence of textural components, as well as the volume fraction of each textural

  4. Intrauterine Treatment of a Fetus with Familial Hypertrophic Cardiomyopathy Secondary to MYH7 Mutation.

    PubMed

    Hill, Meghan G; Sekhon, Mehtab K; Reed, Kathryn L; Anderson, Caroline F; Borjon, Nydia D; Tardiff, Jil C; Barber, Brent J

    2015-12-01

    There is no clear consensus on optimal management of fetuses affected by familial hypertrophic cardiomyopathy (HCM). Intrauterine treatment of the condition has not been attempted in any standardized fashion. We report the case of a fetus treated by maternal propranolol during the third trimester after septal hypertrophy and diastolic dysfunction was diagnosed on fetal echocardiogram. The pregnancy went successfully to term, and fetal septal hypertrophy was noted to improve prior to delivery. PMID:26337809

  5. Coronary artery ectasia and systolic flow cessation in a patient with hypertrophic cardiomyopathy: a case report.

    PubMed

    Zografos, Theodoros; Kokladi, Maria; Katritsis, Demosthenes

    2010-12-01

    Coronary artery ectasia (CAE) is characterized by diffuse or localized inappropriate dilation of coronary arteries and is often associated with slow coronary blood flow. Although CAE has been described to coexist with several clinical entities there are only three reports of CAE in the presence of hypertrophic cardiomyopathy (HCM). We report a case of CAE and slow coronary flow with systolic flow cessation in a 61-year old male with coronary artery disease and HCM.

  6. Health related quality of life and psychological wellbeing in patients with hypertrophic cardiomyopathy.

    PubMed Central

    Cox, S.; O'Donoghue, A. C.; McKenna, W. J.; Steptoe, A.

    1997-01-01

    OBJECTIVE: To assess the health related quality of life and psychological wellbeing of patients with hypertrophic cardiomyopathy, to correlate these with symptoms, clinical, and psychosocial factors. DESIGN: Questionnaire distributed to 171 hypertrophic cardiomyopathy patients aged at least 14 years, selected at random from a dataset of 480 patients. Assessments included the Short Form 36 (SF-36) Health Survey, the Hospital Anxiety and Depression questionnaire, and measures of adjustment, worry, and patient satisfaction. RESULTS: There was an 80.1% response rate to the questionnaire. Patients had severe limitations in all eight dimensions of quality of life assessed by the SF-36: physical functioning, role limitations owing to physical problems, role limitations owing to emotional problems, social functioning, mental health, general health perceptions, vitality, and bodily pain. Levels of anxiety and depression were also high compared with population norms. Quality of life was particularly impaired in patients with chest pain and dyspnoea, but was less consistently related to clinical cardiological measures. Adjustment to the condition and patient satisfaction were generally good. In multivariate analysis, quality of life was associated with a combination of symptom patterns and psychosocial factors. No differences in quality of life, anxiety or depression were observed between patients with no known family history, those with familial cardiomyopathy, and patients with a family history of premature sudden death. CONCLUSIONS: Hypertrophic cardiomyopathy is associated with substantial restrictions in health related quality of life. Symptoms, adjustment, and quality of interactions with clinical staff contribute to these limitations. Recognition of the problems confronted by patients with hypertrophic cardiomyopathy requires continued efforts at education both of the public and health professionals. PMID:9326995

  7. Papillary Thyroid Carcinoma Treated with Radiofrequency Ablation in a Patient with Hypertrophic Cardiomyopathy: A Case Report

    PubMed Central

    Sun, Jianyi; Liu, Xiaosun; Zhang, Qing; Hong, Yanyun; Song, Bin; Teng, Xiaodong

    2016-01-01

    Standard therapy has not been established for thyroid cancer when a thyroidectomy is contraindicated due to systemic disease. Herein, we reported a patient who had hypertrophic cardiomyopathy and papillary thyroid carcinoma treated by radiofrequency ablation because of inability to tolerate a thyroidectomy. Radiofrequency ablation can be used to treat thyroid cancer when surgery is not feasible, although the long-term outcome needs further observation. PMID:27390548

  8. Role of endocardial septal ablation in the treatment of hypertrophic obstructive cardiomyopathy.

    PubMed

    Aksu, Tolga; Güler, Tümer Erdem; Yalın, Kıvanç; Gölcük, Şükriye Ebru; Özcan, Kazım Serhan

    2016-09-01

    Septal reduction therapy is accepted as a first therapeutic option for symptomatic drug-resistant hypertrophic obstructive cardiomyopathy (HOCM). Although, surgical septal myectomy is the gold standard method, alcohol septal ablation is a well-studied alternative approach in the patients with suitable anatomy. Endocardial septal ablation (ESA) therapy was relatively new defined modality and outcomes of the procedure were not clearly elucidated yet. We aimed to review the clinical aspects of ESA procedure and provide some historical background. PMID:27609434

  9. Hypertrophic osteodystrophy preceding canine juvenile cellulitis in an Australian shepherd puppy

    PubMed Central

    Wentzell, Meaghan L.

    2011-01-01

    A 10-week-old intact female Australian shepherd dog was presented sternally recumbent, mildly pyrexic, and painful on long bone palpation of both forelimbs. Based on radiographs she was diagnosed with hypertrophic osteodystrophy. Analgesia was provided with intravenous, oral, and topical medications. Approximately 2 wk later she was presented for facial swelling, regional dermatitis, and lymphadenopathy. Canine juvenile cellulitis was diagnosed and successfully treated. PMID:21731101

  10. Hydrologic data and description of a hydrologic monitoring plan for Medicine Lake Volcano, California

    USGS Publications Warehouse

    Schneider, Tiffany Rae; McFarland, W.D.

    1996-01-01

    A hydrologic reconnaissance of the Medicine Lake Volcano area was done to collect data needed for the design of a hydrologic monitoring plan. The reconnaissance was completed during two field trips made in June and September 1992, during which geothermal and hydrologic features of public interest in the Medicine Lake area were identified. Selected wells, springs, and geothermal features were located and documented, and initial water-level, discharge, temperature, and specific-conductance measurements were made. Lakes in the study area also were surveyed during the September field trip. Temperature, specific- conductance, dissolved oxygen, and pH data were collected by using a multiparameter probe. The proposed monitoring plan includes measurement of water levels in wells, discharge from springs, and lake stage, as well as analysis of well-,spring-, and lake-water quality. In determining lake-water quality, data for both stratified and unstratified conditions would be considered. (Data for stratified conditions were collected during the reconnaissance phase of this project, but data for unstratified conditions were not.) In addition, lake stage also would be monitored. A geothermal feature near Medicine Lake is a "hot spot" from which hot gases discharge from two distinct vents. Gas chemistry and temperature would be monitored in one of these vents.

  11. Dilated cardiomyopathy and impaired cardiac hypertrophic response to angiotensin II in mice lacking FGF-2

    PubMed Central

    Pellieux, Corinne; Foletti, Alessandro; Peduto, Giovanni; Aubert, Jean-François; Nussberger, Jürg; Beermann, Friedrich; Brunner, Hans-R.; Pedrazzini, Thierry

    2001-01-01

    FGF-2 has been implicated in the cardiac response to hypertrophic stimuli. Angiotensin II (Ang II) contributes to maintain elevated blood pressure in hypertensive individuals and exerts direct trophic effects on cardiac cells. However, the role of FGF-2 in Ang II–induced cardiac hypertrophy has not been established. Therefore, mice deficient in FGF-2 expression were studied using a model of Ang II–dependent hypertension and cardiac hypertrophy. Echocardiographic measurements show the presence of dilated cardiomyopathy in normotensive mice lacking FGF-2. Moreover, hypertensive mice without FGF-2 developed no compensatory cardiac hypertrophy. In wild-type mice, hypertrophy was associated with a stimulation of the c-Jun N-terminal kinase, the extracellular signal regulated kinase, and the p38 kinase pathways. In contrast, mitogen-activated protein kinase (MAPK) activation was markedly attenuated in FGF-2–deficient mice. In vitro, FGF-2 of fibroblast origin was demonstrated to be essential in the paracrine stimulation of MAPK activation in cardiomyocytes. Indeed, fibroblasts lacking FGF-2 expression have a defective capacity for releasing growth factors to induce hypertrophic responses in cardiomyocytes. Therefore, these results identify the cardiac fibroblast population as a primary integrator of hypertrophic stimuli in the heart, and suggest that FGF-2 is a crucial mediator of cardiac hypertrophy via autocrine/paracrine actions on cardiac cells. PMID:11748268

  12. Osteogenic differentiation of hypertrophic chondrocytes involves asymmetric cell divisions and apoptosis

    PubMed Central

    1995-01-01

    We have investigated the early cellular events that take place during the change in lineage commitment from hypertrophic chondrocytes to osteoblast-like cells. We have induced this osteogenic differentiation by cutting through the hypertrophic cartilage of embryonic chick femurs and culturing the explants. Immunocytochemical characterization, [3H]thymidine pulse-chase labeling, in situ nick translation or end labeling of DNA breaks were combined with ultrastructural studies to characterize the changing pattern of differentiation. The first responses to the cutting, seen after 2 d, were upregulation of alkaline phosphatase activity, synthesis of type I collagen and single-stranded DNA breaks, probably indicating a metastable state. Associated with the change from chondrogenic to osteogenic commitment was an asymmetric cell division with diverging fates of the two daughter cells, where one daughter cell remained viable and the other one died. The available evidence suggests that the viable daughter cell then divided and generated osteogenic cells, while the other daughter cell died by apoptosis. The results suggest a new concept of how changes in lineage commitment of differentiated cells may occur. The concepts also reconcile previously opposing views of the fate of the hypertrophic chondrocyte. PMID:7593173

  13. Cone of skin exists in rat: A "hypertrophic scarring free" animal.

    PubMed

    Zuo, Yanhai; Yu, Xiaoping; Lu, Shuliang

    2016-08-01

    Cone of skin is deemed to be related to hypertrophic scarring and absent in such traditionally "hypertrophic scarring and keloid free" animals as rat. The purpose of our study is to determine whether the cone of skin exists in rat. If it was, why it was ignored, and what was the meaning of it. The depilation of left dorsum of 32 male Sprague-Dawley rats was performed using a wax/rosin mixture. Skin samples were harvested on 0 d, 3 d, 9 d, 15 d, 21 d, 27 d, 33 d, and 39 d after depilation and stained by hematoxylin and eosin methods. Light microscopic observation of the dermis-fat interface was studied at 25× magnification. It was observed that, "dome" like fat tissue bulged up into the dermis from 3 d to 27 d and hair follicle bulged down into the "dome" like fat tissue from 15 d to 27 d and a "cone" like structure was seen. Cone of skin exists in rat in certain stages of hair follicle cycle, which is a valuable addition to the scientific literature and might be a challenge to the relation between cone of skin and hypertrophic scarring. Anat Rec, 299:1140-1144, 2016. © 2016 Wiley Periodicals, Inc. PMID:27125905

  14. Astragaloside IV attenuates apoptosis of hypertrophic cardiomyocyte through inhibiting oxidative stress and calpain-1 activation.

    PubMed

    Mei, Meng; Tang, Futian; Lu, Meili; He, Xin; Wang, Hongxin; Hou, Xuwei; Hu, Jin; Xu, Chonghua; Han, Ronghui

    2015-11-01

    Calpain-1 activation and oxidative stress are two critical factors contributing to apoptosis of hypertrophic cardiomyocyte. Astragaloside IV (ASIV) exhibits protective effect against various heart diseases. The present study was designed to investigate whether the inhibitory effect of ASIV on isoproterenol (ISO)-induced apoptosis of hypertrophic cardiomyocyte was associated with the anti-oxidation and calpain-1 inhibition. Hypertrophy, apoptosis, mitochondrial oxidative stress and calpain-1 expression were measured in the heart tissue of Sprague-Dawley (SD) rats and H9C2 cells treated with ISO alone or combination with ASIV. The results showed that ASIV attenuated apoptotic rate, increased Bcl-2 expression, decreased Bax expression, ameliorated the integrity of mitochondrial structure and improved mitochondrial membrane potential (MMP). Moreover, ASIV combination reduced both calpain-1 protein expression and calpain activity, down-regulated mitochondrial NOX4 (mito-NOX4) expression, increased activity of mitochondrial superoxide dismutase (mito-SOD) and mitochondrial catalase (mito-CAT) compared to ISO treated alone. The results suggested that ASIV exerted anti-apoptosis effect on ISO-induced hypertrophic cardiomyocyte by attenuating oxidative stress and calpain-1 activation. PMID:26433482

  15. Amentoflavone inhibits angiogenesis of endothelial cells and stimulates apoptosis in hypertrophic scar fibroblasts.

    PubMed

    Zhang, Jinli; Liu, Zhihe; Cao, Wenjuan; Chen, Liying; Xiong, Xifeng; Qin, Shengnan; Zhang, Zhi; Li, Xiaojian; Hu, Chien-an A

    2014-08-01

    Amentoflavone (8-[5-(5,7-dihydroxy-4-oxo-chromen-2-yl)-2-hydroxy-phenyl]-5,7-dihydroxy-2-(4-hydroxyphenyl) chromen-4-one; AF) is a biflavonoid derived from the extracts of Selaginella tamariscina. It has been shown that AF has diverse biological effects such as antitumour, etc. It is well known that high cell proliferation, viability, angiogenesis and low apoptosis are key factors in hypertrophic scar formation. In this study, we report that AF inhibited viability and stimulated apoptosis in hypertrophic scar fibroblasts (HSFBs). Incubation of HSFBs with AF showed its inhibitory effect on cell viability and the exhibition of a series of cellular changes that were consistent with apoptosis. By Western-blot analysis, our data indicated significant increases in the amounts of cleaved caspases 3, 8, 9 and Bax, several apoptotic promoters and a significant decrease in translationally controlled tumour protein (TCTP), an apoptotic inhibitor, in HSFBs treated with AF. Furthermore, AF showed significant inhibitions on the viability, migration and tube formation of endothelial cells, which are associated with angiogenesis. In conclusion, this study suggests that AF stimulates apoptosis in HSFBs and inhibits angiogenesis of endothelial cells. Therefore, AF is a promising molecule that can be used in hypertrophic scar treatment.

  16. Inhibition of cyclooxygenase-2 impacts chondrocyte hypertrophic differentiation during endochondral ossification.

    PubMed

    Welting, T J M; Caron, M M J; Emans, P J; Janssen, M P F; Sanen, K; Coolsen, M M E; Voss, L; Surtel, D A M; Cremers, A; Voncken, J W; van Rhijn, L W

    2011-01-01

    Skeletogenesis and bone fracture healing involve endochondral ossification, a process during which cartilaginous primordia are gradually replaced by bone tissue. In line with a role for cyclooxygenase-2 (COX-2) in the endochondral ossification process, non-steroidal anti-inflammatory drugs (NSAIDs) were reported to negatively affect bone fracture healing due to impaired osteogenesis. However, a role for COX-2 activity in the chondrogenic phase of endochondral ossification has not been addressed before. We show that COX-2 activity fulfils an important regulatory function in chondrocyte hypertrophic differentiation. Our data reveal essential cross-talk between COX-2 and bone morphogenic protein-2 (BMP-2) during chondrocyte hypertrophic differentiation. BMP-2 mediated chondrocyte hypertrophy is associated with increased COX-2 expression and pharmacological inhibition of COX-2 activity by NSAIDs (e.g., Celecoxib) decreases hypertrophic differentiation in various chondrogenic models in vitro and in vivo, while leaving early chondrogenic development unaltered. Our findings demonstrate that COX-2 activity is a novel factor partaking in chondrocyte hypertrophy in the context of endochondral ossification and these observations provide a novel etiological perspective on the adverse effects of NSAIDs on bone fracture healing and have important implications for the use of NSAIDs during endochondral skeletal development. PMID:22183916

  17. Stratified charge rotary aircraft engine technology enablement program

    NASA Technical Reports Server (NTRS)

    Badgley, P. R.; Irion, C. E.; Myers, D. M.

    1985-01-01

    The multifuel stratified charge rotary engine is discussed. A single rotor, 0.7L/40 cu in displacement, research rig engine was tested. The research rig engine was designed for operation at high speeds and pressures, combustion chamber peak pressure providing margin for speed and load excursions above the design requirement for a high is advanced aircraft engine. It is indicated that the single rotor research rig engine is capable of meeting the established design requirements of 120 kW, 8,000 RPM, 1,379 KPA BMEP. The research rig engine, when fully developed, will be a valuable tool for investigating, advanced and highly advanced technology components, and provide an understanding of the stratified charge rotary engine combustion process.

  18. Avoidance-preference testing in density stratified solutions

    SciTech Connect

    Smith, E.H.; Logan, D.T.; Hansen, S.

    1994-12-31

    Toxicity testing is sometimes required where density stratifies test and reference solutions. Examples include freshwater effluents that float in estuarine and marine waters and desalinating plant effluents that sink. Standard avoidance-preference testing methods and apparatus are designed to test horizontal rather than vertical gradients and so are inappropriate for density stratified solutions. To overcome associated deficiencies, the authors modified testing chambers to take advantage of density stratification. Exposure levels for tests were selected based on NOELs from standard toxicity testing. Behavior of 10 striped bass was simultaneously observed using electronic surveillance. Measure of behavior include position in two axes and swimming speed. Avoidance-preference between several types of high density byproducts of salt water evaporation and lower density receiving water were tested. Results indicate that the modified test protocols allowed the authors to determine behavior responses to test materials.

  19. Investigation of salt stratified solar pond operational characteristics

    NASA Astrophysics Data System (ADS)

    Newell, T. A.

    1980-12-01

    Operational characteristics and economic feasibility of the salt stratified solar pond are examined. A one dimensional transient numerical model is developed which offers flexibility for pond property specifications, thermal energy performance prediction, and thermal energy extraction uses. Stability of the gradient zone of a salt stratified pond is one of the most important areas of pond operational feasibility. A criterion for the operational state of a solar pond which constrains the allowable salinity and temperature profiles is developed and extended for use as a design tool for solar ponds. The decanting method of thermal energy extraction is most feasible for large scale ponds. A two dimensional numerical fluid dynamics program has been developed for this purpose and examines the effect of inlet and outlet jet placement in the storage zone of a pond. A simple laboratory experiment for qualitative investigations of solar pond phenomena is described.

  20. Laboratory experiments on stratified flow through a suspended porous fence

    NASA Astrophysics Data System (ADS)

    Delavan, Sarah; Nokes, Roger; Plew, David

    2012-11-01

    This study explores stratified flow through a suspended, porous, fence-like obstacle to simulate flow through fish farm cages, mussel farm rope suspensions, flow through suspended aquatic vegetation, underwater energy production structures, or windbreak and wave break fencing. Laboratory experiments were performed in a density stratified, stationary flume with a suspended porous fence model using a particle tracking velocimetry (PTV) system. Experiments explored the effect on the fluid of the fence depth to total depth ratio, the system Richardson number, and the porosity of the fence. Preliminary results suggest that the density stratification of the fluid inhibits vertical fluid motion, that fence porosity greatly controls the vertical mixing of the fluid, and that there may be an optimal fence depth to total depth ratio for full development of the system flow structures.

  1. Elementary stratified flows with stability at low Richardson number

    SciTech Connect

    Barros, Ricardo; Choi, Wooyoung

    2014-12-15

    We revisit the stability analysis for three classical configurations of multiple fluid layers proposed by Goldstein [“On the stability of superposed streams of fluids of different densities,” Proc. R. Soc. A. 132, 524 (1931)], Taylor [“Effect of variation in density on the stability of superposed streams of fluid,” Proc. R. Soc. A 132, 499 (1931)], and Holmboe [“On the behaviour of symmetric waves in stratified shear layers,” Geophys. Publ. 24, 67 (1962)] as simple prototypes to understand stability characteristics of stratified shear flows with sharp density transitions. When such flows are confined in a finite domain, it is shown that a large shear across the layers that is often considered a source of instability plays a stabilizing role. Presented are simple analytical criteria for stability of these low Richardson number flows.

  2. Developing stratified epithelia: Lessons from the epidermis and thymus

    PubMed Central

    Roberts, Natalie; Horsley, Valerie

    2014-01-01

    Stratified squamous epithelial cells are found in a number of organs, including the skin epidermis and the thymus. The progenitor cells of the developing epidermis form a multilayered epithelium and appendages, like the hair follicle, to generate an essential barrier to protect against water loss and invasion of foreign pathogens. In contrast, the thymic epithelium forms a three-dimensional mesh of keratinocytes that are essential for positive and negative selection of self-restricted T cells. While these distinct stratified epithelial tissues derive from distinct embryonic germ layers, both tissues instruct immunity, and the epithelial differentiation programs and molecular mechanisms that control their development are remarkably similar. In this review, we aim to highlight some of the similarities between the thymus and the skin epidermis and its appendages during developmental specification. PMID:25176390

  3. Experimental and theoretical studies of wakes in stratified flows

    NASA Astrophysics Data System (ADS)

    Boyer, Don L.; Fernando, H. J.

    1995-01-01

    The long range goal was to obtain, by laboratory experimentation and associated theoretical/numerical analysis, an increased understanding of the dynamics of stratified flow past blunt obstacles including two-dimensional ones such as right circular cylinders and three-dimensional ones such as spheres. Emphasis was given to such phenomena as blocking, flow separation, vortex shedding, lee-wave generation, unsteady characteristics of the free stream, and lift and drag on the obstacles in question.

  4. Stability of stratified two-phase flows in inclined channels

    NASA Astrophysics Data System (ADS)

    Barmak, I.; Gelfgat, A. Yu.; Ullmann, A.; Brauner, N.

    2016-08-01

    Linear stability of the stratified gas-liquid and liquid-liquid plane-parallel flows in the inclined channels is studied with respect to all wavenumber perturbations. The main objective is to predict the parameter regions in which the stable stratified configuration in inclined channels exists. Up to three distinct base states with different holdups exist in the inclined flows, so that the stability analysis has to be carried out for each branch separately. Special attention is paid to the multiple solution regions to reveal the feasibility of the non-unique stable stratified configurations in inclined channels. The stability boundaries of each branch of the steady state solutions are presented on the flow pattern map and are accompanied by the critical wavenumbers and the spatial profiles of the most unstable perturbations. Instabilities of different nature are visualized by the streamlines of the neutrally stable perturbed flows, consisting of the critical perturbation superimposed on the base flow. The present analysis confirms the existence of two stable stratified flow configurations in a region of low flow rates in the countercurrent liquid-liquid flows. These configurations become unstable with respect to the shear mode of instability. It was revealed that in slightly upward inclined flows the lower and middle solutions for the holdup are stable in the part of the triple solution region, while the upper solution is always unstable. In the case of downward flows, in the triple solution region, none of the solutions are stable with respect to the short-wave perturbations. These flows are stable only in the single solution region at low flow rates of the heavy phase, and the long-wave perturbations are the most unstable ones.

  5. Sea surface wind stress in stratified atmospheric flow

    SciTech Connect

    Myrhaug, D.; Slaattelid, O.H.

    1996-12-31

    The paper presents the wind shear stress on the sea surface as well as the velocity profile in stably stratified atmospheric boundary layer flow over wind waves by using similarity theory. For a given geostrophic velocity, Coriolis parameter, spectral peak period and stratification parameter the sea surface shear stress is determined. Further, the direction of the sea surface shear stress and the velocity profile are given. Parameterizations of the results are also presented. Finally, the engineering relevance of the results is discussed.

  6. Hamiltonian structure for rotational capillary waves in stratified flows

    NASA Astrophysics Data System (ADS)

    Martin, Calin Iulian

    2016-07-01

    We show that the governing equations of two-dimensional water waves driven by surface tension propagating over two-layered stratified flows admit a Hamiltonian formulation. Moreover, the underlying flows that we consider here, have piecewise constant distribution of vorticity, the jump in vorticity being located along the interface separating the fluid of bigger density at the bottom from the lighter fluid adjacent to the free surface.

  7. Computation of mixing in large stably stratified enclosures

    NASA Astrophysics Data System (ADS)

    Zhao, Haihua

    This dissertation presents a set of new numerical models for the mixing and heat transfer problems in large stably stratified enclosures. Basing on these models, a new computer code, BMIX++ (Berkeley mechanistic MIXing code in C++), was developed by Christensen (2001) and the author. Traditional lumped control volume methods and zone models cannot model the detailed information about the distributions of temperature, density, and pressure in enclosures and therefore can have significant errors. 2-D and 3-D CFD methods require very fine grid resolution to resolve thin substructures such as jets, wall boundaries, yet such fine grid resolution is difficult or impossible to provide due to computational expense. Peterson's scaling (1994) showed that stratified mixing processes in large stably stratified enclosures can be described using one-dimensional differential equations, with the vertical transport by free and wall jets modeled using standard integral techniques. This allows very large reductions in computational effort compared to three-dimensional numerical modeling of turbulent mixing in large enclosures. The BMIX++ code was developed to implement the above ideas. The code uses a Lagrangian approach to solve 1-D transient governing equations for the ambient fluid and uses analytical models or 1-D integral models to compute substructures. 1-D transient conduction model for the solid boundaries, pressure computation and opening models are also included to make the code more versatile. The BMIX++ code was implemented in C++ and the Object-Oriented-Programming (OOP) technique was intensively used. The BMIX++ code was successfully applied to different types of mixing problems such as stratification in a water tank due to a heater inside, water tank exchange flow experiment simulation, early stage building fire analysis, stratification produced by multiple plumes, and simulations for the UCB large enclosure experiments. Most of these simulations gave satisfying

  8. SATURATED-SUBCOOLED STRATIFIED FLOW IN HORIZONTAL PIPES

    SciTech Connect

    Richard Schultz

    2010-08-01

    Advanced light water reactor systems are designed to use passive emergency core cooling systems with horizontal pipes that provide highly subcooled water from water storage tanks or passive heat exchangers to the reactor vessel core under accident conditions. Because passive systems are driven by density gradients, the horizontal pipes often do not flow full and thus have a free surface that is exposed to saturated steam and stratified flow is present.

  9. Continuous Dependence on the Density for Stratified Steady Water Waves

    NASA Astrophysics Data System (ADS)

    Chen, Robin Ming; Walsh, Samuel

    2016-02-01

    There are two distinct regimes commonly used to model traveling waves in stratified water: continuous stratification, where the density is smooth throughout the fluid, and layer-wise continuous stratification, where the fluid consists of multiple immiscible strata. The former is the more physically accurate description, but the latter is frequently more amenable to analysis and computation. By the conservation of mass, the density is constant along the streamlines of the flow; the stratification can therefore be specified by prescribing the value of the density on each streamline. We call this the streamline density function. Our main result states that, for every smoothly stratified periodic traveling wave in a certain small-amplitude regime, there is an L ∞ neighborhood of its streamline density function such that, for any piecewise smooth streamline density function in that neighborhood, there is a corresponding traveling wave solution. Moreover, the mapping from streamline density function to wave is Lipschitz continuous in a certain function space framework. As this neighborhood includes piecewise smooth densities with arbitrarily many jump discontinues, this theorem provides a rigorous justification for the ubiquitous practice of approximating a smoothly stratified wave by a layered one. We also discuss some applications of this result to the study of the qualitative features of such waves.

  10. Survival analysis of cervical cancer using stratified Cox regression

    NASA Astrophysics Data System (ADS)

    Purnami, S. W.; Inayati, K. D.; Sari, N. W. Wulan; Chosuvivatwong, V.; Sriplung, H.

    2016-04-01

    Cervical cancer is one of the mostly widely cancer cause of the women death in the world including Indonesia. Most cervical cancer patients come to the hospital already in an advanced stadium. As a result, the treatment of cervical cancer becomes more difficult and even can increase the death's risk. One of parameter that can be used to assess successfully of treatment is the probability of survival. This study raises the issue of cervical cancer survival patients at Dr. Soetomo Hospital using stratified Cox regression based on six factors such as age, stadium, treatment initiation, companion disease, complication, and anemia. Stratified Cox model is used because there is one independent variable that does not satisfy the proportional hazards assumption that is stadium. The results of the stratified Cox model show that the complication variable is significant factor which influent survival probability of cervical cancer patient. The obtained hazard ratio is 7.35. It means that cervical cancer patient who has complication is at risk of dying 7.35 times greater than patient who did not has complication. While the adjusted survival curves showed that stadium IV had the lowest probability of survival.

  11. Stratified source-sampling techniques for Monte Carlo eigenvalue analysis.

    SciTech Connect

    Mohamed, A.

    1998-07-10

    In 1995, at a conference on criticality safety, a special session was devoted to the Monte Carlo ''Eigenvalue of the World'' problem. Argonne presented a paper, at that session, in which the anomalies originally observed in that problem were reproduced in a much simplified model-problem configuration, and removed by a version of stratified source-sampling. In this paper, stratified source-sampling techniques are generalized and applied to three different Eigenvalue of the World configurations which take into account real-world statistical noise sources not included in the model problem, but which differ in the amount of neutronic coupling among the constituents of each configuration. It is concluded that, in Monte Carlo eigenvalue analysis of loosely-coupled arrays, the use of stratified source-sampling reduces the probability of encountering an anomalous result over that if conventional source-sampling methods are used. However, this gain in reliability is substantially less than that observed in the model-problem results.

  12. Direct Numerical Simulation of a Weakly Stratified Turbulent Wake

    NASA Technical Reports Server (NTRS)

    Redford, J. A.; Lund, T. S.; Coleman, Gary N.

    2014-01-01

    Direct numerical simulation (DNS) is used to investigate a time-dependent turbulent wake evolving in a stably stratified background. A large initial Froude number is chosen to allow the wake to become fully turbulent and axisymmetric before stratification affects the spreading rate of the mean defect. The uncertainty introduced by the finite sample size associated with gathering statistics from a simulation of a time-dependent flow is reduced, compared to earlier simulations of this flow. The DNS reveals the buoyancy-induced changes to the turbulence structure, as well as to the mean-defect history and the terms in the mean-momentum and turbulence-kinetic-energy budgets, that characterize the various states of this flow - namely the three-dimensional (essentially unstratified), non-equilibrium (or 'wake-collapse') and quasi-two-dimensional (or 'two-component') regimes observed elsewhere for wakes embedded in both weakly and strongly stratified backgrounds. The wake-collapse regime is not accompanied by transfer (or 'reconversion') of the potential energy of the turbulence to the kinetic energy of the turbulence, implying that this is not an essential feature of stratified-wake dynamics. The dependence upon Reynolds number of the duration of the wake-collapse period is demonstrated, and the effect of the details of the initial/near-field conditions of the wake on its subsequent development is examined.

  13. Ethanol dehydration to ethylene in a stratified autothermal millisecond reactor.

    PubMed

    Skinner, Michael J; Michor, Edward L; Fan, Wei; Tsapatsis, Michael; Bhan, Aditya; Schmidt, Lanny D

    2011-08-22

    The concurrent decomposition and deoxygenation of ethanol was accomplished in a stratified reactor with 50-80 ms contact times. The stratified reactor comprised an upstream oxidation zone that contained Pt-coated Al(2)O(3) beads and a downstream dehydration zone consisting of H-ZSM-5 zeolite films deposited on Al(2)O(3) monoliths. Ethanol conversion, product selectivity, and reactor temperature profiles were measured for a range of fuel:oxygen ratios for two autothermal reactor configurations using two different sacrificial fuel mixtures: a parallel hydrogen-ethanol feed system and a series methane-ethanol feed system. Increasing the amount of oxygen relative to the fuel resulted in a monotonic increase in ethanol conversion in both reaction zones. The majority of the converted carbon was in the form of ethylene, where the ethanol carbon-carbon bonds stayed intact while the oxygen was removed. Over 90% yield of ethylene was achieved by using methane as a sacrificial fuel. These results demonstrate that noble metals can be successfully paired with zeolites to create a stratified autothermal reactor capable of removing oxygen from biomass model compounds in a compact, continuous flow system that can be configured to have multiple feed inputs, depending on process restrictions. PMID:21834091

  14. A Zoology of unstable modes in a stratified cylinder wake

    NASA Astrophysics Data System (ADS)

    Bosco, Mickael; Meunier, Patrice

    2013-11-01

    Although the dynamics of a cylinder wake is well known and extremely rich for a homogeneous fluid, very few studies have been focused on stratified wakes despite the obvious extensive number of applications for geophysical flows and submarine wakes. The presence of the stratification may largely modify the dynamics of the wake. The study is devoted to understand the effect of the tilt and also of a strong stratification. So extensive experimental and numerical results have been investigated to describe the full dynamics of a tilted cylinder wake. For weak stratification and small tilt angle, the classical mode A found for a homogeneous fluid is still present, but for a large tilt angle, an instability appearing far from the cylinder is created. The case of a cylinder towed a very stratified fluid has been finally investigated. The dynamics is strongly modified and for moderate tilt angles, a new unstable mode appears with a structure similar to the Kelvin-Helmholtz billows (observed in the critical layer of a tilted stratified vortex), whereas for large tilt angles, another unstable mode characterized by a strong shear appears generated without a 2D von Karman structure. This reveals the rich dynamics of the cylinder wake in the presence of a stable stratification.

  15. MRI channel flows in vertically stratified models of accretion discs

    NASA Astrophysics Data System (ADS)

    Latter, Henrik N.; Fromang, Sebastien; Gressel, Oliver

    2010-08-01

    Simulations of the magnetorotational instability (MRI) in `unstratified' shearing boxes exhibit powerful coherent flows, whereby the fluid vertically splits into countermoving planar jets or `channels'. Channel flows correspond to certain axisymmetric linear MRI modes, and their preponderance follows from the remarkable fact that they are approximate non-linear solutions of the MHD equations in the limit of weak magnetic fields. We show in this paper, analytically and with one-dimensional numerical simulations, that this property is also shared by certain axisymmetric MRI modes in vertically stratified shearing boxes. These channel flows rapidly capture significant amounts of magnetic and kinetic energy, and thus are vulnerable to secondary shear instabilities. We examine these parasites in the vertically stratified context, and estimate the maximum amplitudes that channels attain before they are destroyed. These estimates suggest that a dominant channel flow will usually drive the disc's magnetic field to thermal strengths. The prominence of these flows and their destruction place enormous demands on simulations, but channels in their initial stages also offer a useful check on numerical codes. These benchmarks are especially valuable given the increasing interest in the saturation of the stratified MRI. Lastly, we speculate on the potential connection between `run-away' channel flows and outburst behaviour in protostellar and dwarf nova discs.

  16. Stability of stratified two-phase flows in horizontal channels

    NASA Astrophysics Data System (ADS)

    Barmak, I.; Gelfgat, A.; Vitoshkin, H.; Ullmann, A.; Brauner, N.

    2016-04-01

    Linear stability of stratified two-phase flows in horizontal channels to arbitrary wavenumber disturbances is studied. The problem is reduced to Orr-Sommerfeld equations for the stream function disturbances, defined in each sublayer and coupled via boundary conditions that account also for possible interface deformation and capillary forces. Applying the Chebyshev collocation method, the equations and interface boundary conditions are reduced to the generalized eigenvalue problems solved by standard means of numerical linear algebra for the entire spectrum of eigenvalues and the associated eigenvectors. Some additional conclusions concerning the instability nature are derived from the most unstable perturbation patterns. The results are summarized in the form of stability maps showing the operational conditions at which a stratified-smooth flow pattern is stable. It is found that for gas-liquid and liquid-liquid systems, the stratified flow with a smooth interface is stable only in confined zone of relatively low flow rates, which is in agreement with experiments, but is not predicted by long-wave analysis. Depending on the flow conditions, the critical perturbations can originate mainly at the interface (so-called "interfacial modes of instability") or in the bulk of one of the phases (i.e., "shear modes"). The present analysis revealed that there is no definite correlation between the type of instability and the perturbation wavelength.

  17. Spontaneous layer formation dynamics in stratified Taylor-Couette flow

    NASA Astrophysics Data System (ADS)

    Leclercq, Colin; Partridge, Jamie L.; Augier, Pierre; Caulfield, C. P.; Linden, Paul F.; Dalziel, Stuart B.; MUST Collaboration

    2015-11-01

    The spontaneous formation of horizontal layers is a common feature of strongly and stably stratified flows and plays a major role in the dynamics of geophysical flows. However, little is known about the physical mechanism setting the depth of the layers spontaneously emerging in ``stratified Taylor-Couette flow'' in the annulus between a rotating inner cylinder and a fixed outer cylinder, initially filled with stably, axially and linearly stratified fluid. Using linear stability analysis, direct numerical simulations and experiments, we investigate the relative importance of primary linear instability and secondary nonlinear processes in the transient dynamics leading to the experimentally and numerically observed step-like density profile in this flow. We explore the effects of the particular form of the spin-up of the inner cylinder and initial conditions on the transient dynamics and nonlinear attractor of the flow. By better understanding the dynamics of layer formation, we are able to identify the approriate scaling laws relating layer depth to rotation rate, initial stratification, gap width and radius ratio. EPSRC programme grant EP/K034529/1.

  18. Background stratified Poisson regression analysis of cohort data

    PubMed Central

    Langholz, Bryan

    2012-01-01

    Background stratified Poisson regression is an approach that has been used in the analysis of data derived from a variety of epidemiologically important studies of radiation-exposed populations, including uranium miners, nuclear industry workers, and atomic bomb survivors. We describe a novel approach to fit Poisson regression models that adjust for a set of covariates through background stratification while directly estimating the radiation-disease association of primary interest. The approach makes use of an expression for the Poisson likelihood that treats the coefficients for stratum-specific indicator variables as ‘nuisance’ variables and avoids the need to explicitly estimate the coefficients for these stratum-specific parameters. Log-linear models, as well as other general relative rate models, are accommodated. This approach is illustrated using data from the Life Span Study of Japanese atomic bomb survivors and data from a study of underground uranium miners. The point estimate and confidence interval obtained from this ‘conditional’ regression approach are identical to the values obtained using unconditional Poisson regression with model terms for each background stratum. Moreover, it is shown that the proposed approach allows estimation of background stratified Poisson regression models of non-standard form, such as models that parameterize latency effects, as well as regression models in which the number of strata is large, thereby overcoming the limitations of previously available statistical software for fitting background stratified Poisson regression models. PMID:22193911

  19. Ethanol Dehydration to Ethylene in a Stratified Autothermal Millisecond Reactor

    SciTech Connect

    Skinner, MJ; Michor, EL; Fan, W; Tsapatsis, M; Bhan, A; Schmidt, LD

    2011-08-10

    The concurrent decomposition and deoxygenation of ethanol was accomplished in a stratified reactor with 50-80 ms contact times. The stratified reactor comprised an upstream oxidation zone that contained Pt-coated Al(2)O(3) beads and a downstream dehydration zone consisting of H-ZSM-5 zeolite films deposited on Al(2)O(3) monoliths. Ethanol conversion, product selectivity, and reactor temperature profiles were measured for a range of fuel:oxygen ratios for two autothermal reactor configurations using two different sacrificial fuel mixtures: a parallel hydrogen-ethanol feed system and a series methane-ethanol feed system. Increasing the amount of oxygen relative to the fuel resulted in a monotonic increase in ethanol conversion in both reaction zones. The majority of the converted carbon was in the form of ethylene, where the ethanol carbon-carbon bonds stayed intact while the oxygen was removed. Over 90% yield of ethylene was achieved by using methane as a sacrificial fuel. These results demonstrate that noble metals can be successfully paired with zeolites to create a stratified autothermal reactor capable of removing oxygen from biomass model compounds in a compact, continuous flow system that can be configured to have multiple feed inputs, depending on process restrictions.

  20. Background stratified Poisson regression analysis of cohort data.

    PubMed

    Richardson, David B; Langholz, Bryan

    2012-03-01

    Background stratified Poisson regression is an approach that has been used in the analysis of data derived from a variety of epidemiologically important studies of radiation-exposed populations, including uranium miners, nuclear industry workers, and atomic bomb survivors. We describe a novel approach to fit Poisson regression models that adjust for a set of covariates through background stratification while directly estimating the radiation-disease association of primary interest. The approach makes use of an expression for the Poisson likelihood that treats the coefficients for stratum-specific indicator variables as 'nuisance' variables and avoids the need to explicitly estimate the coefficients for these stratum-specific parameters. Log-linear models, as well as other general relative rate models, are accommodated. This approach is illustrated using data from the Life Span Study of Japanese atomic bomb survivors and data from a study of underground uranium miners. The point estimate and confidence interval obtained from this 'conditional' regression approach are identical to the values obtained using unconditional Poisson regression with model terms for each background stratum. Moreover, it is shown that the proposed approach allows estimation of background stratified Poisson regression models of non-standard form, such as models that parameterize latency effects, as well as regression models in which the number of strata is large, thereby overcoming the limitations of previously available statistical software for fitting background stratified Poisson regression models. PMID:22193911

  1. Between- and within-lake responses of macrophyte richness metrics to shoreline developmen

    USGS Publications Warehouse

    Beck, Marcus W.; Vondracek, Bruce C.; Hatch, Lorin K.

    2013-01-01

    Aquatic habitat in littoral environments can be affected by residential development of shoreline areas. We evaluated the relationship between macrophyte richness metrics and shoreline development to quantify indicator response at 2 spatial scales for Minnesota lakes. First, the response of total, submersed, and sensitive species to shoreline development was evaluated within lakes to quantify macrophyte response as a function of distance to the nearest dock. Within-lake analyses using generalized linear mixed models focused on 3 lakes of comparable size with a minimal influence of watershed land use. Survey points farther from docks had higher total species richness and presence of species sensitive to disturbance. Second, between-lake effects of shoreline development on total, submersed, emergent-floating, and sensitive species were evaluated for 1444 lakes. Generalized linear models were developed for all lakes and stratified subsets to control for lake depth and watershed land use. Between-lake analyses indicated a clear response of macrophyte richness metrics to increasing shoreline development, such that fewer emergent-floating and sensitive species were correlated with increasing density of docks. These trends were particularly evident for deeper lakes with lower watershed development. Our results provide further evidence that shoreline development is associated with degraded aquatic habitat, particularly by illustrating the response of macrophyte richness metrics across multiple lake types and different spatial scales.

  2. Seismic reflection study of recessional moraines beneath Lake Superior and their relationship to regional deglaciation

    USGS Publications Warehouse

    Landmesser, C.W.; Johnson, T.C.; Wold, R.J.

    1982-01-01

    Approximately 8000 km of continuous seismic reflection profiles throughout Lake Superior were examined for evidence of recessional moraines and other ice-margin deposits associated with the retreat of late Wisconsin ice. These features are correlated with the record of glacial-lake evolution in western Lake Superior. An offlapping sequence of glacial and glacial-lacustrine dediments overlying bedrock is recognized in west-central Lake Superior that is progressively younger to the northeast. The sequence underlies more recent glaical-lacustrine and postglacial sediments. Four facies are recognized on the basis of geomorphologic and acoustic properties and are interpreted to represent a southwest-to-northeast assemblage of: proglacial stratified drift (facies A), drift in major end moraines (facies B), till deposited as glacial retreat resumed, or possibly late-stage ablation till (facies C), and basal till (facies D). The prominent moraines of facies B are unusually thick and are believed to mark the ice-margin shorelines of successive major proglacial lakes that formerly occupied parts of western Lake Superior. The moraines are tentatively correlated with Glacial Lake Duluth (unit 1), Glacial Lake Washburn (unit 2), and Glacial Lake Beaver Bay (unit 3), the most prominent of lakes drained via the progressively lower outlets via the Moose Lake/ Brule-St. Croix Rivers, the Huron Mountains, and the Au Train-Whitefish regions, respectively. ?? 1982.

  3. Regime Shifts in Lakes: Organic Carbon Dynamics and Whole Ecosystem Responses

    NASA Astrophysics Data System (ADS)

    Anderson, N. J.

    2015-12-01

    The concept of using sediment records to identify regime shifts in lakes has largely focussed on biological proxies, such as diatoms and chironomids. In this approach, long-term records of rapid ecological change are compared with independent proxies of the variables driving ecosystem change, for example, climate or catchment disturbance processes (hydrological budgets, deforestation, fire etc.). One of the main problems with this approach is that the sediment cores upon which the data analyses are made are taken from the central part of lakes, often at the deepest point. As a result, the ecological changes observed reflect pelagic (open water) processes rather than whole-lake responses. As most lakes (apart from hypertrophic systems) are dominated by benthic production it is unclear whether palaeolimnological assessments of regime shifts are representative of the whole lake response. Theoretically, this question can be addressed simply by using cores from shallow water. There are a number of problems with this approach, most notably the loss of temporal resolution in shallow water cores (due to the slower sediment accumulation rate) and the different biological assemblages in the shallow water (littoral) cores. There is a strong effect of water depth on the zonation and distribution of biological remains across any lake. An alternative approach therefore is to use total organic carbon [OC] accumulation rate as a measure of the whole lake response to see if there is, in fact, a regime shift at the whole lake scale. Here I present examples of Holocene OC accumulation rate responses to external forcing from shallow eutrophic and boreal lakes and compare them to biological records of structural ecological change to determine whether there has been a whole-lake regime shift.

  4. RELATIONSHIP OF STREAM FLOW REGIME IN THE WESTERN LAKE SUPERIOR BASIN TO WATERSHED TYPE CHARACTERISTICS

    EPA Science Inventory

    To test a conceptual model of nonlinear response of hydrologic regimes to watershed characteristics, we selected 48 second- and third-order study sites on the North and South Shores of western Lake Superior, MN (USA) using a random-stratified design based on hydrogeomorphic regio...

  5. Geohydrology and water quality of stratified-drift aquifers in the Contoocook River basin, south-central New Hampshire

    USGS Publications Warehouse

    Harte, P.T.; Johnson, William

    1995-01-01

    Stratified-drift aquifers discontinuously underlie 121 mi2 (square miles) of the Contoocook River Basin, which has a total drainage area of 776 mi2. Maps of these aquifers, showing water-table configurations, saturated thicknesses, and transmissivities were prepared from well and test-hole data and seismic-refraction profiles. The distribution of stratified-drift aquifers is largely controlled by the Pleistocene glaciation process and the formation of multiple glacial lakes along the main stem of the Contoocook River. Locally, saturated thickness of stratified drift within these aquifers are as great as 200 feet. Estimated transmissivities exceed 8,000 ft2/d (squared feet per day) at three locations and is as high as 22,800 ft2/d at one location. Stratified-drift aquifers that have the greatest potential to supply additional amounts of water include the aquifers at Greenfield-Otter Brook and Hancock-Norway Pond. Potential yields to hypothetical supply wells were estimated for the Greenfield-Otter Brook, Hillsborough-Contoocook River, and Andover- Blackwater River aquifers by use of a analytical ground-water-flow model. The model results predict that the potential yields are greatest from the Greenfield-Otter Brook aquifer, yielding up to 1.85 gallons per day during half-year periods of no recharge. The effective ground-water recharge to the entire basin, which includes recharge to the till, bedrock, and stratified drift, is 13.9 in./yr (inches per year) (521 million gallons per day) on the basis of hydrograph separation of streamflow. The quality of water obtained from 11 observation wells and 10 municipal supply wells is generally suitable for drinking and most other domestic purposes. Ground water in the region has low alkalinity, is slightly acidic, and has low concentrations of dissolved solids. Concentrations of dissolved constituents in ground-water samples were generally less than the U.S. Environmental Protection Agency's primary and secondary maximum

  6. Numerical simulation of 2D buoyant jets in ice-covered and temperature-stratified water

    NASA Astrophysics Data System (ADS)

    Gu, Ruochuan

    A two-dimensional (2D) unsteady simulation model is applied to the problem of a submerged warm water discharge into a stratified lake or reservoir with an ice cover. Numerical simulations and analyses are conducted to gain insight into large-scale convective recirculation and flow processes in a cold waterbody induced by a buoyant jet. Jet behaviors under various discharge temperatures are captured by directly modeling flow and thermal fields. Flow structures and processes are described by the simulated spatial and temporal distributions of velocity and temperature in various regions: deflection, recirculation, attachment, and impingement. Some peculiar hydrothermal and dynamic features, e.g. reversal of buoyancy due to the dilution of a warm jet by entraining cold ambient water, are identified and examined. Simulation results show that buoyancy is the most important factor controlling jet behavior and mixing processes. The inflow boundary is treated as a liquid wall from which the jet is offset. Similarity and difference in effects of boundaries perpendicular and parallel to flow, and of buoyancy on jet attachment and impingement, are discussed. Symmetric flow configuration is used to de-emphasize the Coanda effect caused by offset.

  7. Sulfur transformations at the hydrogen sulfide/oxygen interface in stratified waters and in cyanobacterial mats

    NASA Technical Reports Server (NTRS)

    Cohen, Y.

    1985-01-01

    Stratified water bodies allow the development of several microbial plates along the water column. The microbial plates develop in relation to nutrient availability, light penetration, and the distribution of oxygen and sulfide. Sulfide is initially produced in the sediment by sulfate-reducing bacteria. It diffuses along the water column creating a zone of hydrogen sulfide/oxygen interface. In the chemocline of Solar Lake oxygen and sulfide coexist in a 0 to 10 cm layer that moves up and down during a diurnal cycle. The microbial plate at the chemocline is exposed to oxygen and hydrogen sulfide, alternating on a diurnal basis. The cyanobacteria occupying the interface switch from anoxygenic photosynthesis in the morning to oxygenic photosynthesis during the rest of the day which results in a temporal build up of elemental sulfur during the day and disappears at night due to both oxidation to thiosulfate and sulfate by thiobacilli, and reduction to hydrogen sulfide by Desulfuromonas sp. and anaerobically respiring cyanobacteria. Sulfate reduction was enhanced in the light at the surface of the cyanobacterial mats. Microsulfate reduction measurements showed enhanced activity of sulfate reduction even under high oxygen concentrations of 300 to 800 micrometer. Apparent aerobic SO sub 4 reduction activity is explained by the co-occurrence of H sub 2. The physiology of this apparent sulfate reduction activity is studied.

  8. Longevity of Lake Superior lake trout

    USGS Publications Warehouse

    Schram, Stephen T.; Fabrizio, Mary C.

    1998-01-01

    The age structure of mature lake trout Salvelinus namaycush from the Wisconsin waters of Lake Superior increased following a population recovery that has taken place since the 1960s. As the population aged, it became apparent that scales were unreliable aging structures. Beginning in 1986, we examined both scale and sagittal otolith ages from tagged fish with a known period at liberty. We found large discrepancies in scale and sagittal otolith ages of mature fish, such that scale ages were biased low. We estimated lake trout living up to 42 years, which is greater than previously reported from Lake Superior. Investigators studying lake trout population dynamics in the Great Lakes should be aware that lake trout can live longer than previously thought.

  9. Lake Volta, Ghana

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This true-color image of Lake Volta in Ghana was acquired March 31, 2002 by the Moderate Resolution Imaging Spectroradiometer (MODIS). Lake Volta is one of the world's largest artificially created lakes. Lake Volta is actually a reservoir formed from the damming of the Volta River, and extends 250 miles north of the Akosombo Dam. The lake covers an area of 8,482 square km. Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  10. Paleoenvironments, Evolution, and Geomicrobiology in a Tropical Pacific Lake: The Lake Towuti Drilling Project (TOWUTI)

    NASA Astrophysics Data System (ADS)

    Vogel, Hendrik; Russell, James M.; Bijaksana, Satria; Crowe, Sean; Fowle, David; Haffner, Douglas; King, John; Marwoto, Ristiyanti; Melles, Martin; von Rintelen, Thomas; Stevenson, Janelle; Watkinson, Ian; Wattrus, Nigel

    2014-05-01

    Lake Towuti (2.5°S, 121°E) is a, 560 km2, 200-m deep tectonic lake at the downstream end of the Malili lake system, a set of five, ancient (1-2 MYr) tectonic lakes in central Sulawesi, Indonesia. Lake Towuti's location in central Indonesia provides a unique opportunity to reconstruct long-term paleoclimate change in a crucially important yet understudied region- the Indo-Pacific warm pool (IPWP), heart of the El Niño-Southern Oscillation. The Malili Lakes have extraordinarily high rates of floral and faunal endemism, and the lakes are surrounded by one of the most diverse tropical forests on Earth. Drilling in Lake Towuti will identify the age and origin of the lake and the environmental and climatic context that shaped the evolution of this unique lacustrine and terrestrial ecosystem. The ultramafic (ophiolitic) rocks and lateritic soils surrounding Lake Towuti provide metal substrates that feed a diverse, exotic microbial community, analogous to the microbial ecosystems that operated in the Archean Oceans. Drill core will provide unique insight into long-term changes in this ecosystem, as well as microbial processes operating at depth in the sediment column. High-resolution seismic reflection data (CHIRP and airgun) combined with numerous long sediment piston cores collected from 2007-2013 demonstrate the enormous promise of Lake Towuti for an ICDP drilling campaign. Well-stratified sequences of up to 150 m thickness, uninterrupted by unconformities or erosional truncation, are present in multiple sub-basins within Towuti, providing ideal sites for long-term environmental, climatic, and limnological reconstructions. Multiproxy analyses of our piston cores document a continuous and detailed record of moisture balance variations in Lake Towuti during the past 60 kyr BP. In detail our datasets show that wet conditions and rainforest ecosystems in central Indonesia persisted during Marine Isotope Stage 3 (MIS3) and the Holocene, and were interrupted by severe

  11. Paleoenvironments, Evolution, and Geomicrobiology in a Tropical Pacific Lake: The Lake Towuti Drilling Project (TOWUTI)

    NASA Astrophysics Data System (ADS)

    Vogel, Hendrik; Russell, James M.; Bijaksana, Satria; Fowle, David; von Rintelen, Thomas; Stevenson, Janelle; Watkinson, Ian; Marwoto, Ristiyanti; Melles, Martin; Crowe, Sean; Haffner, Doug; King, John

    2013-04-01

    Lake Towuti (2.5°S, 121°E) is a, 560 km2, 200-m deep tectonic lake at the downstream end of the Malili lake system, a set of five, ancient (1-2 MYr) tectonic lakes in central Sulawesi, Indonesia. Lake Towuti's location in central Indonesia provides a unique opportunity to reconstruct long-term paleoclimate change in a crucially important yet understudied region- the tropical Western Pacific warm pool, heart of the El Niño-Southern Oscillation. The Malili Lakes have extraordinarily high rates of floral and faunal endemism, and the lakes are surrounded by one of the most diverse tropical forests on Earth. Drilling in Lake Towuti will identify the age and origin of the lake and the environmental and climatic context that shaped the evolution of this unique lacustrine and terrestrial ecosystem. The ultramafic (ophiolitic) rocks and lateritic soils surrounding Lake Towuti provide metal substrates that feed a diverse, exotic microbial community, analogous to the microbial ecosystems that operated in the Archean Oceans. Drill core will provide unique insight into long-term changes in this ecosystem, as well as microbial processes operating at depth in the sediment column. While the Malili Lakes have long been considered high-priority drilling sites, only now do we have the requisite site survey information to propose the development of ICDP's first lake drilling target in the tropical western Pacific. High-resolution seismic reflection data (CHIRP and airgun) combined with numerous long sediment piston cores collected from 2007-2010 demonstrate the enormous promise of Lake Towuti for an ICDP drilling campaign. Well-stratified sequences of up to 150 m thickness, uninterrupted by unconformities or erosional truncation, are present in multiple sub-basins within Towuti, providing ideal sites for long-term environmental, climatic, and limnological reconstructions. Multiproxy analyses of our piston cores document a continuous and detailed record of moisture balance

  12. ESMI: a macrophyte index for assessing the ecological status of lakes.

    PubMed

    Ciecierska, Hanna; Kolada, Agnieszka

    2014-09-01

    The paper introduces the Ecological State Macrophyte Index (ESMI), a method compliant with the Water Framework Directive (2000/60/EC) for assessing the ecological status of lakes based on macrophytes. A description of the elaboration of macrophyte metrics, relevant reference conditions and a classification system for two types of high-alkalinity lowland lakes (stratified and polymictic), and a customised field survey procedure based on belt transects are presented. The ESMI evaluates two aspects of macrophyte community: taxonomic composition (index of evenness J) and abundance (colonisation index Z), which are combined into one multimetric. ESMI values range from 0 to 1, where 1 denotes pristine conditions and 0, highly degraded habitats. The high/good class boundary (H/G) was set at the first quartile of ESMI values of reference lakes. For the other classes, boundaries were set by dividing the range of ESMI values between the H/G boundary and the minimum value recorded in the dataset in a logarithmic scale into four. The ESMI correlated best with water transparency (Pearson's R = 0.62 in stratified lakes and 0.79 in polymictic ones), whereas the correlations with phosphorus and nitrogen concentrations were somewhat weaker (R = -0.48 to -0.57). Based on the results of international intercalibration, the original class boundaries were modified (merged for stratified and polymictic lakes, the good/moderate boundary tightened to approximately 20%), to make ESMI-based assessment results comparable with the outcomes of other European methods.

  13. Recruitment of Hexagenia mayfly nymphs in western Lake Erie linked to environmental variability

    USGS Publications Warehouse

    Bridgeman, Thomas B.; Schloesser, Don W.; Krause, Ann E.

    2006-01-01

    After a 40-year absence caused by pollution and eutrophication, burrowing mayflies (Hexagenia spp.) recolonized western Lake Erie in the mid 1990s as water quality improved. Mayflies are an important food resource for the economically valuable yellow perch fishery and are considered to be major indicator species of the ecological condition of the lake. Since their reappearance, however, mayfly populations have suffered occasional unexplained recruitment failures. In 2002, a failure of fall recruitment followed an unusually warm summer in which western Lake Erie became temporarily stratified, resulting in low dissolved oxygen levels near the lake floor. In the present study, we examined a possible link between Hexagenia recruitment and periods of intermittent stratification for the years 1997-2002. A simple model was developed using surface temperature, wind speed, and water column data from 2003 to predict stratification. The model was then used to detect episodes of stratification in past years for which water column data are unavailable. Low or undetectable mayfly recruitment occurred in 1997 and 2002, years in which there was frequent or extended stratification between June and September. Highest mayfly reproduction in 2000 corresponded to the fewest stratified periods. These results suggest that even relatively brief periods of stratification can result in loss of larval mayfly recruitment, probably through the effects of hypoxia. A trend toward increasing frequency of hot summers in the Great Lakes region could result in recurrent loss of mayfly larvae in western Lake Erie and other shallow areas in the Great Lakes.

  14. Sex stratified neuronal cultures to study ischemic cell death pathways.

    PubMed

    Fairbanks, Stacy L; Vest, Rebekah; Verma, Saurabh; Traystman, Richard J; Herson, Paco S

    2013-01-01

    Sex differences in neuronal susceptibility to ischemic injury and neurodegenerative disease have long been observed, but the signaling mechanisms responsible for those differences remain unclear. Primary disassociated embryonic neuronal culture provides a simplified experimental model with which to investigate the neuronal cell signaling involved in cell death as a result of ischemia or disease; however, most neuronal cultures used in research today are mixed sex. Researchers can and do test the effects of sex steroid treatment in mixed sex neuronal cultures in models of neuronal injury and disease, but accumulating evidence suggests that the female brain responds to androgens, estrogens, and progesterone differently than the male brain. Furthermore, neonate male and female rodents respond differently to ischemic injury, with males experiencing greater injury following cerebral ischemia than females. Thus, mixed sex neuronal cultures might obscure and confound the experimental results; important information might be missed. For this reason, the Herson Lab at the University of Colorado School of Medicine routinely prepares sex-stratified primary disassociated embryonic neuronal cultures from both hippocampus and cortex. Embryos are sexed before harvesting of brain tissue and male and female tissue are disassociated separately, plated separately, and maintained separately. Using this method, the Herson Lab has demonstrated a male-specific role for the ion channel TRPM2 in ischemic cell death. In this manuscript, we share and discuss our protocol for sexing embryonic mice and preparing sex-stratified hippocampal primary disassociated neuron cultures. This method can be adapted to prepare sex-stratified cortical cultures and the method for embryo sexing can be used in conjunction with other protocols for any study in which sex is thought to be an important determinant of outcome. PMID:24378980

  15. Stratified spin-up in a sliced, square cylinder

    SciTech Connect

    Munro, R. J.; Foster, M. R.

    2014-02-15

    We previously reported experimental and theoretical results on the linear spin-up of a linearly stratified, rotating fluid in a uniform-depth square cylinder [M. R. Foster and R. J. Munro, “The linear spin-up of a stratified, rotating fluid in a square cylinder,” J. Fluid Mech. 712, 7–40 (2012)]. Here we extend that analysis to a “sliced” square cylinder, which has a base-plane inclined at a shallow angle α. Asymptotic results are derived that show the spin-up phase is achieved by a combination of the Ekman-layer eruptions (from the perimeter region of the cylinder's lid and base) and cross-slope-propagating stratified Rossby waves. The final, steady state limit for this spin-up phase is identical to that found previously for the uniform depth cylinder, but is reached somewhat more rapidly on a time scale of order E{sup −1/2}Ω{sup −1}/log (α/E{sup 1/2}) (compared to E{sup −1/2}Ω{sup −1} for the uniform-depth cylinder), where Ω is the rotation rate and E the Ekman number. Experiments were performed for Burger numbers, S, between 0.4 and 16, and showed that for S≳O(1), the Rossby modes are severely damped, and it is only at small S, and during the early stages, that the presence of these wave modes was evident. These observations are supported by the theory, which shows the damping factors increase with S and are numerically large for S≳O(1)

  16. Magnetic Field in the Gravitationally Stratified Coronal Loops

    NASA Astrophysics Data System (ADS)

    Dwivedi, B. N.; Srivastava, A. K.

    2015-03-01

    We study the effect of gravitational stratification on the estimation of magnetic fields in the coronal loops. By using the method of MHD seismology of kink waves for the estimation of magnetic field of coronal loops, we derive a new formula for the magnetic field considering the effect of gravitational stratification. The fast-kink wave is a potential diagnostic tool for the estimation of magnetic field in fluxtubes. We consider the eleven kink oscillation cases observed by TRACE between July 1998 and June 2001. We calculate magnetic field in the stratified loops ( B str) and compare them with the previously calculated absolute magnetic field ( B abs). The gravitational stratification efficiently affects the magnetic field estimation in the coronal loops as it affects also the properties of kink waves. We find ≈22% increment in the magnetic field for the smallest ( L = 72 Mm) while ≈ 42% increment in the absolute magnetic field for the longest ( L = 406 Mm) coronal loops. The magnetic fields B str and B abs also increase with the number density, if the loop length does not vary much. The increment in the magnetic field due to gravitational stratification is small at the lower number densities, however, it is large at the higher number densities. We find that damping time of kink waves due to phase-mixing is less in the case of gravitationally stratified loops compared to nonstratified ones. This indicates the more rapid damping of kink waves in the stratified loops. In conclusion, we find that the gravitational stratification efficiently affects the estimation of magnetic field and damping time estimation especially in the longer coronal loops.

  17. Egg freezing, stratified reproduction and the logic of not

    PubMed Central

    Ikemoto, Lisa C.

    2015-01-01

    This commentary examines social and political implications of social egg freezing in a market that is stratified, globalized, and part of a larger bioeconomy. John Robertson's article and public discourse prompted by Facebook and Apple's ‘corporate egg freezing’ benefits provide touchstones for interrogating social and industry practices that embrace making reproductive capacity marketable. Supply of the cells and bodies necessary for assisted reproductive technology use depends on market thinking and structural inequality. What the industry produces are carefully calibrated social-political distances between participants in egg freezing and banking, as well as ‘third party reproduction.’ PMID:27774187

  18. Low Reynolds number swimming in a stratified fluid

    NASA Astrophysics Data System (ADS)

    Doostmohammadi, Amin; Stocker, Roman; Ardekani, Arezoo

    2011-11-01

    Significant progress has been made in analyzing low-Reynolds number locomotion in homogeneous fluids. Even though many aquatic environments are influenced by vertical variations in density, the effects of stratification on the hydrodynamics of swimming of small organisms are very poorly understood. In this article, by using a squirmer model, we show that motility, energy expenditure, and nutrient uptake of small organisms in a density stratified fluid can be largely influenced due to buoyancy effects. Not only does the stratification suppress the swimming velocity, but it also enhances the nutrient uptake and the energy required for a squirmer to swim across pycnoclines. This work is supported by NSF grant CBET-1066545.

  19. Fluid mixing in stratified gravity currents: the Prandtl mixing length.

    PubMed

    Odier, P; Chen, J; Rivera, M K; Ecke, R E

    2009-04-01

    Shear-induced vertical mixing in a stratified flow is a key ingredient of thermohaline circulation. We experimentally determine the vertical flux of momentum and density of a forced gravity current using high-resolution velocity and density measurements. A constant eddy-viscosity model provides a poor description of the physics of mixing, but a Prandtl mixing length model relating momentum and density fluxes to mean velocity and density gradients works well. For the average gradient Richardson number Ri(g) approximately 0.08 and a Taylor Reynolds number Re(lambda) approximately 100, the mixing lengths are fairly constant, about the same magnitude, comparable to the turbulent shear length.

  20. Development of a natural gas stratified charge rotary engine

    SciTech Connect

    Sierens, R.; Verdonck, W.

    1985-01-01

    A water model has been used to determine the positions of separate inlet ports for a natural gas, stratified charge rotary engine. The flow inside the combustion chamber (mainly during the induction period) has been registered by a film camera. From these tests the best locations of the inlet ports have been obtained, a prototype of this engine has been built by Audi NSU and tested in the laboratories of the university of Gent. The results of these tests, for different stratification configurations, are given. These results are comparable with the best results obtained by Audi NSU for a homogeneous natural gas rotary engine.

  1. Energy Spectra of Strongly Stratified and Rotating Turbulence

    NASA Technical Reports Server (NTRS)

    Mahalov, Alex; Nicolaenko, Basil; Zhou, Ye

    1998-01-01

    Turbulence under strong stratification and rotation is usually characterized as quasi-two dimensional turbulence. We develop a "quasi-two dimensional" energy spectrum which changes smoothly between the Kolmogorov -5/3 law (no stratification), the -2 scalings of Zhou for the case of strong rotation, as well as the -2 scalings for the case of strong rotation and stratification. For strongly stratified turbulence, the model may give the -2 scaling predicted by Herring; and the -5/3 scaling indicated by some mesoscale observations.

  2. Hydrology of the Goat Lake watershed, Snohomish County, Washington, 1982-87

    USGS Publications Warehouse

    Dion, N.P.; Ebbert, J.C.; Poole, J.E.; Peck, B.S.

    1989-01-01

    The Goat Lake watershed in Snohomish County, Washington, functions as an ' experimental watershed ' for long-term studies to determine the effects of acidic precipitation on water resources. Data have been collected there by the U.S. Geological Survey since 1982. The watershed is in a wilderness area of the Cascade Range and is downwind of an industrial and urban area that produces chemical compounds found in acidic precipitation. The lake is considered sensitive to acidic inputs from atmospheric deposition and streamflow. The mean annual discharge of the Goat Lake outflow is 35 cu ft/sec; precipitation on the watershed is calculated to be about 170 in/yr. The inflow to Goat Lake is sufficient to replace the entire contents of the lake basin on an average every 21.5 days, or 17 times/year. Water in Goat Lake, and that of the inlet and outlet, is of low ionic strength and of calcium-bicarbonate type. The lake, although considered oligotrophic, is sufficiently deep to stratify thermally, and summer dissolved-oxygen concentrations in the hypolimnion are depressed. Even though alkalinity and specific conductance at Goat Lake are in the range considered sensitive to acidic inputs , the pH of water in the lake has consistently ranged from 6.1 to 7.2, indicating that the lake is not acidified at this time. (USGS)

  3. Hydrology of Goat Lake watershed, Snohomish County, Washington, 1982-87

    SciTech Connect

    Dion, N.P.; Ebbert, J.C.; Poole, J.E.; Peck, B.S.

    1989-01-01

    The Goat Lake watershed functions as an experimental watershed for long-term studies to determine the effects of acidic precipitation on water resources. Data have been collected there by the US Geological Survey since 1982. The watershed is in a wilderness area of the Cascade Range and is downwind of an industrial and urban area that produces chemical compounds found in acidic precipitation. The lake is considered sensitive to acidic inputs from atmospheric deposition and streamflow. The mean annual discharge of the Goat Lake outflow is 35 cu ft/sec; precipitation on the watershed is calculated to be about 170 in/yr. The inflow to Goat Lake is sufficient to replace the entire contents of the lake basin on an average every 21.5 days, or 17 times/year. Water in Goat Lake, and that of the inlet and outlet, is of low ionic strength and of calcium-bicarbonate type. The lake, although considered oligotrophic, is sufficiently deep to stratify thermally, and summer dissolved-oxygen concentrations in the hypolimnion are depressed. Even though alkalinity and specific conductance at Goat Lake are in the range considered sensitive to acidic inputs, the pH of water in the lake has consistently ranged from 6.1 to 7.2, indicating that the lake is not acidified at this time. 36 refs., 11 figs., 8 tabs.

  4. River-Lake Mixing, Eutrophication, and Hypoxia in Green Bay, Lake Michigan

    NASA Astrophysics Data System (ADS)

    Klump, J. V.; LaBuhn, S.

    2014-12-01

    Despite being a freshwater system, Green Bay in Lake Michigan, has many estuarine-like characteristics, including water mass exchange and the mixing between riverine inflow and the open lake. The bay has experienced excessive nutrient loading for decades resulting in hyper-eutrophic conditions and extensive algal blooms. Combined with a restricted, estuarine like circulation, this has resulted in the reoccurrence of late summer "dead zones" and wide spread bottom water oxygen concentrations below water quality standards. The onset of hypoxia is clearly related to thermal stratification which, in Green Bay, arises both from direct atmospheric forcing, i.e. low winds, high air temperatures, and increased solar radiation, and from indirect atmospheric forcing that drives circulation patterns resulting in the southerly incursion of cooler Lake Michigan bottom waters onto highly reducing organic rich sediment deposits. This circulation pattern can re-stratify a well-mixed water column within hours, and can set up stable stratified water column conditions that persist for days to weeks during which time sediment oxygen demand rates are sufficient to completely deplete hypolimnetic oxygen. Modeling hypoxia, therefore, is somewhat more complex than in a system which is driven largely or solely by seasonal thermal fluctuations. Understanding both the general circulation and the onset and duration of stratification in the bay are essential to determining the potential for hypoxic conditions to improve or worsen, particularly in the face of climate change projections of warmer conditions, less ice cover, and an earlier summer. Using D and O-18 isotopes in water, Rn-222, and dissolved methane as tracers we examine the relationship between river/lake mixing, transport rates and oxygen depletion in an attempt to verify the spatial and temporal scales of hypoxia in the bay, and estimate the potential impact of future climate change projections.

  5. Ablative fractional photothermolysis for the treatment of hypertrophic burn scars in adult and pediatric patients: a single surgeon's experience.

    PubMed

    Khandelwal, Anjay; Yelvington, Miranda; Tang, Xinyu; Brown, Susan

    2014-01-01

    Many patients develop hypertrophic scarring after a burn injury. Numerous treatment modalities have been described and are currently in practice. Photothermolysis or laser therapy has been recently described as an adjunct for management of hypertrophic burn scars. This study is a retrospective chart review of adult and pediatric patients undergoing fractional photothermolysis at a verified burn center examining treatment parameters as well as pre- and post-Vancouver Scar Scale scores. Forty-four patients underwent fractional photothermolysis during the study period of 8 months. Mean pretreatment score was 7.6, and mean posttreatment score was 5.4. The mean decrease in score was 2.2, which was found to be statistically significant. There were no complications. Fractional photothermolysis is a safe and efficacious adjunct therapy for hypertrophic burn scars. Prospective trials would be beneficial to determine optimal therapeutic strategies.

  6. Myocardial edema in Takotsubo syndrome mimicking apical hypertrophic cardiomyopathy: An insight into diagnosis by cardiovascular magnetic resonance.

    PubMed

    Izgi, Cemil; Ray, Sanjoy; Nyktari, Evangelia; Alpendurada, Francisco; Lyon, Alexander R; Rathore, Sudhir; Baksi, Arun John

    2015-01-01

    Myocardial edema is one of the characteristic features in the pathogenesis of Takotsubo syndrome. We report a middle aged man who presented with typical clinical and echocardiographic features of apical variant of Takotsubo syndrome. However, a cardiovascular magnetic resonance study performed 10 days after presentation did not show any apical 'ballooning' but revealed features of an apical hypertrophic cardiomyopathy on cine images. Tissue characterization with T2 weighted images proved severe edema as the cause of significantly increased apical wall thickness. A follow-up cardiovascular magnetic resonance study was performed 5 months later which showed that edema, wall thickening and the appearance of apical hypertrophic cardiomyopathy all resolved, confirming Takotsubo syndrome as the cause of the initial appearance. As the affected myocardium most commonly involves the apical segments, an edema induced increase in apical wall thickness may lead to appearances of an apical hypertrophic cardiomyopathy rather than apical ballooning in the acute to subacute phase of Takotsubo syndrome.

  7. Late-onset hypertrophic pyloric stenosis with gastric outlet obstruction: case report and review of the literature.

    PubMed

    Wolf, Lindsey L; Nijagal, Amar; Flores, Alejandro; Buchmiller, Terry L

    2016-10-01

    We report late-onset hypertrophic pyloric stenosis in a 17-year-old female. She presented with abdominal pain and an episode of upper gastrointestinal hemorrhage and subsequently developed gastric outlet obstruction. Work-up revealed circumferential pyloric thickening, delayed gastric emptying, and a stenotic, elongated pyloric channel. Biopsies showed benign gastropathy, negative for Helicobacter pylori, without eosinophilic infiltrates. Botulinum toxin injection provided limited relief. Diagnostic laparoscopy confirmed the hypertrophic pylorus and we performed laparoscopic pyloromyotomy. The patient tolerated the procedure well and had complete symptom resolution at 1-year follow-up. Hypertrophic pyloric stenosis is a rare cause of gastric outlet obstruction in adolescents and may be managed successfully with laparoscopic pyloromyotomy. PMID:27506212

  8. Differential Expression of Cell Cycle Regulators During Hyperplastic and Hypertrophic Growth of Broiler Subcutaneous Adipose Tissue.

    PubMed

    Zhang, J; Suh, Y; Choi, Y M; Chen, P R; Davis, M E; Lee, K

    2015-10-01

    Hyperplastic growth and hypertrophic growth within adipose tissue is tightly associated with cell cycle activity. In this study, CCNG2 and CDKN2C were found to be correlated with cell cycle inhibition during fat cell differentiation, whereas CCND3, CCNA1, and ANAPC5 were positively associated with cell cycle activity during fat cell proliferation after selection based on GEO datasets available on the NCBI website. The findings were validated through comparison of expressions of these genes among different tissues/fractions in broiler chickens and time points during primary cell culture using quantitative real-time PCR. Development of broiler subcutaneous adipose tissue was investigated on embryonic days 15 and 17 and on post-hatch days 0, 5, 11, and 33 using H&E staining and PCNA immunostaining with DAPI counter stain. In addition, mRNA expressions of five cell cycle regulators as well as precursor cell and adipocyte markers were measured at those time points. The results suggest that cellular proliferation activity decreased as the fat pad grows, but a population of precursor cells seemed to be maintained until post-hatch day 5 despite increasing differentiation activity. Hypertrophic growth gradually intensified despite a slight cessation on post-hatch day 0 due to increased energy expenditure during hatching and delayed food access. From post-hatch day 5 to day 11, most of the precursor cells may become differentiated. After post-hatch day 11, hyperplastic growth seemed to slow, while hypertrophic growth may become dominant. This study provides further understanding about broiler fat tissue development which is imperative for effective control of fat deposition.

  9. Expression of proto-oncogenes and gene mutation of sarcomeric proteins in patients with hypertrophic cardiomyopathy.

    PubMed

    Kai, H; Muraishi, A; Sugiu, Y; Nishi, H; Seki, Y; Kuwahara, F; Kimura, A; Kato, H; Imaizumi, T

    1998-09-21

    Several mutations of cardiac beta-myosin heavy chain (beta-MHC) gene were reported in patients with hypertrophic cardiomyopathy (HCM). Involvement of proto-oncogenes has been shown in the mechanism of experimental cardiac hypertrophy. This study sought to examine the effects of c-H-ras and c-myc expression in the steady-state myocardium on hypertrophic changes and to evaluate the possible interaction between beta-MHC mutation and proto-oncogene expression in HCM. Endomyocardial biopsy was performed in 17 HCM patients (5 beta-MHC mutations and 1 troponin T mutation) and 7 control subjects (no mutation). Reverse transcription-polymerase chain reaction analysis revealed c-H-ras expression in all members of both groups. Cardiomyocyte size was correlated with the expression level of c-H-ras (P<0.001), and c-H-ras expression was upregulated in HCM patients (P<0.01). HCM patients with a beta-MHC mutation had the higher c-H-ras expression than did control subjects or patients without a mutation (P<0.01). c-myc mRNA was expressed in 7 of 17 HCM patients but not in control subjects. Myocyte size was greater in c-myc-positive HCM patients than in control subjects and c-myc-negative HCM patients (P<0.001 and P<0.05, respectively). The proto-oncogene expression did not affect clinical findings, myocardial fibrosis, or disarray. In conclusion, c-H-ras and c-myc expression in the steady-state myocardium may play a role in the hypertrophic mechanism in HCM. It is possible that ss-MHC gene mutation has some effect on the regulation of proto-oncogene expression in HCM.

  10. Time course of the angiogenic response during normotrophic and hypertrophic scar formation in humans.

    PubMed

    van der Veer, Willem M; Niessen, Frank B; Ferreira, José A; Zwiers, Peter J; de Jong, Etty H; Middelkoop, Esther; Molema, Grietje

    2011-01-01

    Previous research suggests that in hypertrophic scars (HSs), an excess of microvessels is present compared with normotrophic scars (NSs). The aim of our study was to quantify vascular densities in HSs and normotrophic scars and to provide an insight into the kinetics of changes in the expression of angiogenic factors in time during wound healing and HS formation. Human presternal wound healing after cardiothoracic surgery through a sternotomy incision was investigated in a standardized manner. Skin biopsies were collected at consecutive time points, i.e., during surgery and 2, 4, 6, 12, and 52 weeks postoperatively. The expression levels of angiopoietin-1, angiopoietin-2, Tie-2, vascular endothelial growth factor, and urokinase-type plasminogen activator were measured by real-time reverse transcription-polymerase chain reaction. Quantification of angiogenesis and cellular localization of the proteins of interest were based on immunohistochemical analysis. Microvessel densities were higher in the HSs compared with the normotrophic scars 12 weeks (p=0.017) and 52 weeks (p=0.030) postoperatively. Angiopoietin-1 expression was lower in the hypertrophic group (p<0.001), which, together with a nonsignificant increase of angiopoietin-2 expression, represented a considerable decrease in the angiopoietin-1/angiopoietin-2 ratio in the hypertrophic group 4 weeks (p=0.053), 12 weeks (p<0.001), and 52 weeks (p<0.001) postoperatively. The expression of urokinase-type plasminogen activator was up-regulated during HS formation (p=0.008). Vascular endothelial growth factor expression was not significantly different when comparing both groups. In summary, the differential expression of angiopoietin-1, angiopoietin-2, and urokinase-type plasminogen activator in time is associated with an increased vascular density in HSs compared with normotrophic scars.

  11. Blunted hypertrophic response in aged skeletal muscle is associated with decreased ribosome biogenesis

    PubMed Central

    Kirby, Tyler J.; Lee, Jonah D.; England, Jonathan H.; Chaillou, Thomas; Esser, Karyn A.

    2015-01-01

    The ability of skeletal muscle to hypertrophy in response to a growth stimulus is known to be compromised in older individuals. We hypothesized that a change in the expression of protein-encoding genes in response to a hypertrophic stimulus contributes to the blunted hypertrophy observed with aging. To test this hypothesis, we determined gene expression by microarray analysis of plantaris muscle from 5- and 25-mo-old mice subjected to 1, 3, 5, 7, 10, and 14 days of synergist ablation to induce hypertrophy. Overall, 1,607 genes were identified as being differentially expressed across the time course between young and old groups; however, the difference in gene expression was modest, with cluster analysis showing a similar pattern of expression between the two groups. Despite ribosome protein gene expression being higher in the aged group, ribosome biogenesis was significantly blunted in the skeletal muscle of aged mice compared with mice young in response to the hypertrophic stimulus (50% vs. 2.5-fold, respectively). The failure to upregulate pre-47S ribosomal RNA (rRNA) expression in muscle undergoing hypertrophy of old mice indicated that rDNA transcription by RNA polymerase I was impaired. Contrary to our hypothesis, the findings of the study suggest that impaired ribosome biogenesis was a primary factor underlying the blunted hypertrophic response observed in skeletal muscle of old mice rather than dramatic differences in the expression of protein-encoding genes. The diminished increase in total RNA, pre-47S rRNA, and 28S rRNA expression in aged muscle suggest that the primary dysfunction in ribosome biogenesis occurs at the level of rRNA transcription and processing. PMID:26048973

  12. Clinical and Histological Correlation in Post-Burn Hypertrophic Scar for Pain and Itching Sensation

    PubMed Central

    Choi, Young-Hee; Kim, Kwang-Min; Kim, Hye-One; Jang, Young-Chul

    2013-01-01

    Background Hypertrophic scar following a burn is caused by the excessive deposit of collagen resulting in an exaggerated wound healing response. The burn patient complains of pain and itching over the scar, which can give rise to cosmetic and functional problems. Objective The aim of this study was to investigate the clinical and histological correlation of a hypertrophic burn scar for itching and pain sensations. Methods Thirty-eight patients underwent a scar release and skin graft. the modified Vancouver scar scale and the verbal numerical rating scale were recorded. All biopsies were taken from scar tissue (scar) and normal tissue (normal). Histologically, tissues were observed in the epidermis, the monocytes around the vessels, the collagen fiber, elastic fiber, and the mast cells. Results The mean total score of MVSS was 8.4±2.7 (pliability 2.0±0.9; thickness 1.8±0.9; vascularity 2.0± 0.9; and pigmentation 2.1±0.9). Pain and itching were 2.4±2.0 and 2.9±3.0. Epidermis were 7.9±2.8 layers (scar) and 4.0±0.8 layers (normal). The collagen fibers were thin and dense (scar) and thicker and loose (normal). The elastic fibers were thin and nonexistent (scar) and thin and loose (normal). Mast cells were 11.2±5.8/high power field (scar) and 7.4±4.1 (normal). Conclusion As the scar tissue thickens, the itching becomes more severe. The stiffness of the scar with the pain appeared to be associated with the condition of the tissue. The correlation between clinical and histological post-burn hypertrophic scars will help further studies on the scar. This helped with the development of the base material for therapeutic strategies. PMID:24371389

  13. The Dynamic Nature of Hypertrophic and Fibrotic Remodeling of the Fish Ventricle

    PubMed Central

    Keen, Adam N.; Fenna, Andrew J.; McConnell, James C.; Sherratt, Michael J.; Gardner, Peter; Shiels, Holly A.

    2016-01-01

    Chronic pressure or volume overload can cause the vertebrate heart to remodel. The hearts of fish remodel in response to seasonal temperature change. Here we focus on the passive properties of the fish heart. Building upon our previous work on thermal-remodeling of the rainbow trout ventricle, we hypothesized that chronic cooling would initiate fibrotic cardiac remodeling, with increased myocardial stiffness, similar to that seen with pathological hypertrophy in mammals. We hypothesized that, in contrast to pathological hypertrophy in mammals, the remodeling response in fish would be plastic and the opposite response would occur following chronic warming. Rainbow trout held at 10°C (control group) were chronically (>8 weeks) exposed to cooling (5°C) or warming (18°C). Chronic cold induced hypertrophy in the highly trabeculated inner layer of the fish heart, with a 41% increase in myocyte bundle cross-sectional area, and an up-regulation of hypertrophic marker genes. Cold acclimation also increased collagen deposition by 1.7-fold and caused an up-regulation of collagen promoting genes. In contrast, chronic warming reduced myocyte bundle cross-sectional area, expression of hypertrophic markers and collagen deposition. Functionally, the cold-induced fibrosis and hypertrophy were associated with increased passive stiffness of the whole ventricle and with increased micromechanical stiffness of tissue sections. The opposite occurred with chronic warming. These findings suggest chronic cooling in the trout heart invokes a hypertrophic phenotype with increased cardiac stiffness and fibrosis that are associated with pathological hypertrophy in the mammalian heart. The loss of collagen and increased compliance following warming is particularly interesting as it suggests fibrosis may oscillate seasonally in the fish heart, revealing a more dynamic nature than the fibrosis associated with dysfunction in mammals. PMID:26834645

  14. Suppressed inflammatory gene expression during human hypertrophic scar compared to normotrophic scar formation.

    PubMed

    van den Broek, Lenie J; van der Veer, Willem M; de Jong, Etty H; Gibbs, Susan; Niessen, Frank B

    2015-08-01

    Hypertrophic scar formation is a result of adverse cutaneous wound healing. The pathogenesis of hypertrophic scar formation is still poorly understood. A problem next to the lack of suitable animal models is that often normal skin is compared to hypertrophic scar (HTscar) and not to normotrophic scar (NTscar) tissue. Another drawback is that often only one time period after wounding is studied, while scar formation is a dynamic process over a period of several months. In this study, we compared the expression of genes involved in inflammation, angiogenesis and extracellular matrix (ECM) formation and also macrophage infiltration in biopsies obtained before and up to 52 weeks after standard surgery in five patients who developed HTscar and six patients who developed NTscar. It was found that HTscar formation coincided with a prolonged decreased expression of inflammatory genes (TNFα, IL-1α, IL-1RN, CCL2, CCL3, CXCL2, CXCR2, C3 and IL-10) and an extended increased expression of ECM-related genes (PLAU, Col3A1, TGFβ3). This coincided with a delayed but prolonged infiltration of macrophages (type 2) in HTscar tissue compared to NTscar tissue. These findings were supported by immunohistochemical localization of proteins coding for select genes named above. Our study emphasizes that human cutaneous wound healing is a dynamic process that is needed to be studied over a period of time rather than a single point of time. Taken together, our results suggest innate immune stimulatory therapies may be a better option for improving scar quality than the currently used anti-inflammatory scar therapies. PMID:25939875

  15. Acute effects of sildenafil and dobutamine in the hypertrophic and failing right heart in vivo.

    PubMed

    Andersen, Asger; Nielsen, Jan M; Rasalingam, Sivagowry; Sloth, Erik; Nielsen-Kudsk, Jens Erik

    2013-09-01

    Abstract The purpose of this study was to investigate whether acute intravenous administration of the phosphodiesterase type 5 (PDE-5) inhibitor sildenafil in a single clinically relevant dose improves the in vivo function of the hypertrophic and failing right ventricle (RV). Wistar rats ([Formula: see text]) were subjected to pulmonary trunk banding (PTB) causing RV hypertrophy and failure. Four weeks after surgery, they were randomized to receive an intravenous bolus dose of sildenafil (1 mg/kg; [Formula: see text]), vehicle ([Formula: see text]), or dobutamine (10 μg/kg; [Formula: see text]). Invasive RV pressures were recorded continuously, and transthoracic echocardiography was performed 1, 5, 15, 25, 35, 50, 70, and 90 minutes after injecting the bolus. Cardiac function was compared to baseline measurements to evaluate the in vivo effects of each specific treatment. The PTB procedure caused significant hypertrophy, cardiac fibrosis, and reduction in RV function evaluated by echocardiography (TAPSE) and invasive pressure measurements. Sildenafil did not improve the function of the hypertrophic failing right heart in vivo, measured by TAPSE, RV systolic pressure (RVsP), and dp/dtmax. Dobutamine improved RV function 1 minute after injection measured by TAPSE ([Formula: see text] vs. [Formula: see text] cm; [Formula: see text]), RVsP ([Formula: see text] vs. [Formula: see text] mmHg; [Formula: see text]), and dp/dtmax ([Formula: see text] vs. [Formula: see text] mmHg/s; [Formula: see text]). Acute administration of the PDE-5 inhibitor sildenafil in a single clinically relevant dose did not modulate the in vivo function of the hypertrophic failing right heart of the rat measured by echocardiography and invasive hemodynamics. In the same model, dobutamine acutely improved RV function. PMID:24618544

  16. 11β-HSD1 reduces metabolic efficacy and adiponectin synthesis in hypertrophic adipocytes.

    PubMed

    Koh, Eun Hee; Kim, Ah-Ram; Kim, Hyunshik; Kim, Jin Hee; Park, Hye-Sun; Ko, Myoung Seok; Kim, Mi-Ok; Kim, Hyuk-Joong; Kim, Bum Joong; Yoo, Hyun Ju; Kim, Su Jung; Oh, Jin Sun; Woo, Chang-Yun; Jang, Jung Eun; Leem, Jaechan; Cho, Myung Hwan; Lee, Ki-Up

    2015-06-01

    Mitochondrial dysfunction in hypertrophic adipocytes can reduce adiponectin synthesis. We investigated whether 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) expression is increased in hypertrophic adipocytes and whether this is responsible for mitochondrial dysfunction and reduced adiponectin synthesis. Differentiated 3T3L1 adipocytes were cultured for up to 21 days. The effect of AZD6925, a selective 11β-HSD1 inhibitor, on metabolism was examined. db/db mice were administered 600 mg/kg AZD6925 daily for 4 weeks via gastric lavage. Mitochondrial DNA (mtDNA) content, mRNA expression levels of 11 β -H sd1 and mitochondrial biogenesis factors, adiponectin synthesis, fatty acid oxidation (FAO), oxygen consumption rate and glycolysis were measured. Adipocyte hypertrophy in 3T3L1 cells exposed to a long duration of culture was associated with increased 11 β -Hsd1 mRNA expression and reduced mtDNA content, mitochondrial biogenesis factor expression and adiponectin synthesis. These cells displayed reduced mitochondrial respiration and increased glycolysis. Treatment of these cells with AZD6925 increased adiponectin synthesis and mitochondrial respiration. Inhibition of FAO by etomoxir blocked the AZD6925-induced increase in adiponectin synthesis, indicating that 11β-HSD1-mediated reductions in FAO are responsible for the reduction in adiponectin synthesis. The expression level of 11 β -Hsd1 was higher in adipose tissues of db/db mice. Administration of AZD6925 to db/db mice increased the plasma adiponectin level and adipose tissue FAO. In conclusion, increased 11β-HSD1 expression contributes to reduced mitochondrial respiration and adiponectin synthesis in hypertrophic adipocytes.

  17. Myocardial metabolic, hemodynamic, and electrocardiographic significance of reversible thallium-201 abnormalities in hypertrophic cardiomyopathy

    SciTech Connect

    Cannon, R.O. 3d.; Dilsizian, V.; O'Gara, P.T.; Udelson, J.E.; Schenke, W.H.; Quyyumi, A.; Fananapazir, L.; Bonow, R.O. )

    1991-05-01

    Exercise-induced abnormalities during thallium-201 scintigraphy that normalize at rest frequently occur in patients with hypertrophic cardiomyopathy. However, it is not known whether these abnormalities are indicative of myocardial ischemia. Fifty patients with hypertrophic cardiomyopathy underwent exercise {sup 201}Tl scintigraphy and, during the same week, measurement of myocardial lactate metabolism and hemodynamics during pacing stress. Thirty-seven patients (74%) had one or more {sup 201}Tl abnormalities that completely normalized after 3 hours of rest; 26 had regional myocardial {sup 201}Tl defects, and 26 had apparent left ventricular cavity dilatation with exercise, with 15 having coexistence of these abnormal findings. Of the 37 patients with reversible {sup 201}Tl abnormalities, 27 (73%) had metabolic evidence of myocardial ischemia during rapid atrial pacing compared with four of 13 patients (31%) with normal {sup 201}Tl scans (p less than 0.01). Eleven patients had apparent cavity dilatation as their only {sup 201}Tl abnormality; their mean postpacing left ventricular end-diastolic pressure was significantly higher than that of the 13 patients with normal {sup 201}Tl studies (33 +/- 5 versus 21 +/- 10 mm Hg, p less than 0.001). There was no correlation between the angiographic presence of systolic septal or epicardial coronary arterial compression and the presence or distribution of {sup 201}Tl abnormalities. Patients with ischemic ST segment responses to exercise had an 80% prevalence rate of reversible {sup 201}Tl abnormalities and a 70% prevalence rate of pacing-induced ischemia. However, 69% of patients with nonischemic ST segment responses had reversible {sup 201}Tl abnormalities, and 55% had pacing-induced ischemia. Reversible {sup 201}Tl abnormalities during exercise stress are markers of myocardial ischemia in hypertrophic cardiomyopathy and most likely identify relatively underperfused myocardium.

  18. Usefulness of MRI to demonstrate the mechanisms of myocardial ischemia in hypertrophic cardiomyopathy with myocardial bridge.

    PubMed

    Thomson, Vivien; Botnar, Rene; Croisille, Pierre

    2007-01-01

    We present a case of symptomatic primary hypertrophic cardiomyopathy (HCM) associated with myocardial bridging of the left anterior descending (LAD) artery and suspected ischemia that could be related either to LAD artery compression or to microvascular perfusion abnormalities. MRI demonstrated the morphological appearance of myocardial hypertrophy, and coronary MR angiography evidenced the myocardial bridge and its functional consequences with stress MR perfusion. In conclusion, as a non-invasive comprehensive imaging technique, MRI should be considered in identifying the mechanisms of myocardial ischemia in HCM with myocardial bridge. PMID:16888385

  19. Right ventricular cavity near obliteration in neonatal severe biventricular hypertrophic cardiomyopathy

    PubMed Central

    Jivanji, Salim GM; Daubeney, Piers; Franklin, Rodney; Sheppard, Mary

    2014-01-01

    A newborn presenting with cyanosis at day 9 of life was admitted to the local hospital. Initial local echocardiography confirmed a cardiac issue and the patient was transferred to a tertiary cardiac hospital. Further imaging confirmed a rare presentation of cardiomyopathy with severe right ventricular outflow tract obstruction. Surgery was performed but with postoperative haemodynamic instability complicated by incessant ventricular tachycardia. Following discussion with the family, care was withdrawn. Postmortem demonstrated a rare form of hypertrophic cardiomyopathy with right ventricular outflow tract obstruction not previously described in a neonate. PMID:25336549

  20. The role of intraoperative transesophageal echocardiographic monitoring in a patient with hypertrophic cardiomyopathy undergoing laparoscopic surgery.

    PubMed

    Gregory, Stephen H; Fierro, Michael A

    2016-11-01

    Hypertrophic cardiomyopathy (HCM) presents a significant perioperative challenge. Anesthetic drugs, patient positioning, and surgical technique can provoke worsening left ventricular outflow tract obstruction and hemodynamic deterioration. In this case report, we present the perioperative management of a 70-year-old male with a history of HCM who underwent a robotic laparoscopic prostatectomy. Discussion focuses on the utilization of echocardiographic guidance in the care of patients with HCM undergoing noncardiac surgery, as well as the pathophysiology of laparoscopic insufflation and its effects on left ventricular outflow tract obstruction in HCM. PMID:27687358

  1. Trileaflet Mitral Valve with Three Papillary Muscles Associated with Hypertrophic Cardiomyopathy: A Novel Case.

    PubMed

    Rosanio, Salvatore; Simonsen, Cameron J; Starwalt, John; Keylani, Abdul M; Vitarelli, Antonio

    2015-09-01

    Congenital mitral valve (MV) malformations are uncommon, except for MV prolapse. Despite their infrequency, most of them are well-known and defined entities, such as congenital MV stenosis with two papillary muscles, parachute MV, supravalvular mitral ring, hypoplastic MV, isolated cleft in the anterior and/or posterior leaflets, and double-orifice MV. A trileaflet MV with three separate papillary muscles with concordant atrioventricular and ventricle-arterial connections is exceptionally rare. To the best of the authors' knowledge, it has been reported only once in association with subaortic valvular stenosis. We hereby describe a novel case associated with hypertrophic cardiomyopathy. PMID:25809503

  2. Homozygous mutations in the 15-hydroxyprostaglandin dehydrogenase gene in patients with primary hypertrophic osteoarthropathy.

    PubMed

    Yüksel-Konuk, Berrin; Sırmacı, Aslı; Ayten, Gülen Ece; Özdemir, Mustafa; Aslan, İdil; Yılmaz-Turay, Ülkü; Erdoğan, Yurdanur; Tekin, Mustafa

    2009-11-01

    Mutations in HPGD have recently been reported to cause primary hypertrophic osteoarthropathy (PHO), a rare genetic disease characterized by digital clubbing, pachydermia, and periostosis. We screened HPGD mutations in six patients from three unrelated Turkish families with PHO, in which we showed one previously reported, p.A140P, and one novel, p.M1L, homozygous mutations. Both mutations co-segregated with the phenotype in all three families and were absent in 100 Turkish controls. These results confirm the presence of biallelic HPGD mutations in patients with PHO in an independent series from a different population. PMID:19306095

  3. Thermal Convection in a Strongly Stratified Two-dimensional Fluid

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Wu, X. L.; Xia, K. Q.

    2004-03-01

    Thermal convection occurs when a fluid becomes gravitationally unstable in the presence of a temperature gradient. While most laboratory experiments investigate convections in fluids with a uniform mass distribution, natural convections often take place in fluids whose density is stratified. In the absence of temperature gradient, a freely suspended soap film stratifies under the action of gravity and assumes a nearly exponential thickness profile similar to the distribution of air mass in atmosphere. In the presence of such a gradient, thermal plumes are generated which drives fluid flows and at the time creates two-dimensional (2D) density fluctuations. We studied thickness power spectra in soap film convection by analyzing thermal radiation signal emitting from a single spot at the center of the film. The experiments were performed at different temperature gradients (ΔT), which were imposed vertically across the film. In the buoyancy sub-range, the frequency power spectrum shows a Bolgiano-Obukhov scaling f-1.4 when ΔT ≤ 50K, and a new scaling relation f-1.0 emerges when ΔT > 50K. This latter behavior was observed to coincide with the appearance of a large-scale circulation in the film.

  4. Spin-up from rest in a stratified fluid

    NASA Astrophysics Data System (ADS)

    Flor, Jan-Bert; Bush, John; Ungarish, Marius

    2002-11-01

    We investigate the spin-up from rest of a stratified fluid with initial Brunt-Väisälä frequency N bound within a cylindrical container of height H and radius R which is set to rotate impulsively with angular speed Ω. The initial phase of motion is marked by the establishment of axisymmetric corner vortices fed by radial Ekman transport, a process detailed in Flor, Ungarish & Bush (2001). The subsequent evolution of the central vortex depends critically on N/f. For N/f > 1 and H/R >1, the axisymmetry of the system is retained throughout the spin-up process: the central vortex attains a state of near solid body rotation by the diffusion of vorticity from the sidewalls. For N/f > 1 and H/R < 1, the central vortex breaks up into a series of vertical vortices that enhance transfer of angular momentum from the boundaries and so expedite the spin-up process. For N/f < 1, the central vortex becomes unstable through a tilting instability. In a short tank, this is marked by a simple tipping of the central stratified vortex. In a tall tank, the centerline of the central vortex is twisted from its vertical position, and the resulting instability gives rise to a stack of vortices with approximately constant Burger ratio Nh/fR.

  5. Dyadic Green's function of an eccentrically stratified sphere.

    PubMed

    Moneda, Angela P; Chrissoulidis, Dimitrios P

    2014-03-01

    The electric dyadic Green's function (dGf) of an eccentrically stratified sphere is built by use of the superposition principle, dyadic algebra, and the addition theorem of vector spherical harmonics. The end result of the analytical formulation is a set of linear equations for the unknown vector wave amplitudes of the dGf. The unknowns are calculated by truncation of the infinite sums and matrix inversion. The theory is exact, as no simplifying assumptions are required in any one of the analytical steps leading to the dGf, and it is general in the sense that any number, position, size, and electrical properties can be considered for the layers of the sphere. The point source can be placed outside of or in any lossless part of the sphere. Energy conservation, reciprocity, and other checks verify that the dGf is correct. A numerical application is made to a stratified sphere made of gold and glass, which operates as a lens. PMID:24690648

  6. Large-scale anisotropy in stably stratified rotating flows.

    PubMed

    Marino, R; Mininni, P D; Rosenberg, D L; Pouquet, A

    2014-08-01

    We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up to 1024(3) grid points and Reynolds numbers of ≈1000. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the kinetic energy displays a perpendicular (horizontal) spectrum with power-law behavior compatible with ∼k(⊥)(-5/3), including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.

  7. Large-scale anisotropy in stably stratified rotating flows

    SciTech Connect

    Marino, R.; Mininni, P. D.; Rosenberg, D. L.; Pouquet, A.

    2014-08-28

    We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up to $1024^3$ grid points and Reynolds numbers of $\\approx 1000$. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the total energy displays a perpendicular (horizontal) spectrum with power law behavior compatible with $\\sim k_\\perp^{-5/3}$, including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.

  8. Large-scale anisotropy in stably stratified rotating flows

    DOE PAGES

    Marino, R.; Mininni, P. D.; Rosenberg, D. L.; Pouquet, A.

    2014-08-28

    We present results from direct numerical simulations of the Boussinesq equations in the presence of rotation and/or stratification, both in the vertical direction. The runs are forced isotropically and randomly at small scales and have spatial resolutions of up tomore » $1024^3$ grid points and Reynolds numbers of $$\\approx 1000$$. We first show that solutions with negative energy flux and inverse cascades develop in rotating turbulence, whether or not stratification is present. However, the purely stratified case is characterized instead by an early-time, highly anisotropic transfer to large scales with almost zero net isotropic energy flux. This is consistent with previous studies that observed the development of vertically sheared horizontal winds, although only at substantially later times. However, and unlike previous works, when sufficient scale separation is allowed between the forcing scale and the domain size, the total energy displays a perpendicular (horizontal) spectrum with power law behavior compatible with $$\\sim k_\\perp^{-5/3}$$, including in the absence of rotation. In this latter purely stratified case, such a spectrum is the result of a direct cascade of the energy contained in the large-scale horizontal wind, as is evidenced by a strong positive flux of energy in the parallel direction at all scales including the largest resolved scales.« less

  9. LONGITUDINAL OSCILLATIONS IN DENSITY STRATIFIED AND EXPANDING SOLAR WAVEGUIDES

    SciTech Connect

    Luna-Cardozo, M.; Verth, G.; Erdelyi, R. E-mail: robertus@sheffield.ac.uk

    2012-04-01

    Waves and oscillations can provide vital information about the internal structure of waveguides in which they propagate. Here, we analytically investigate the effects of density and magnetic stratification on linear longitudinal magnetohydrodynamic (MHD) waves. The focus of this paper is to study the eigenmodes of these oscillations. It is our specific aim to understand what happens to these MHD waves generated in flux tubes with non-constant (e.g., expanding or magnetic bottle) cross-sectional area and density variations. The governing equation of the longitudinal mode is derived and solved analytically and numerically. In particular, the limit of the thin flux tube approximation is examined. The general solution describing the slow longitudinal MHD waves in an expanding magnetic flux tube with constant density is found. Longitudinal MHD waves in density stratified loops with constant magnetic field are also analyzed. From analytical solutions, the frequency ratio of the first overtone and fundamental mode is investigated in stratified waveguides. For small expansion, a linear dependence between the frequency ratio and the expansion factor is found. From numerical calculations it was found that the frequency ratio strongly depends on the density profile chosen and, in general, the numerical results are in agreement with the analytical results. The relevance of these results for solar magneto-seismology is discussed.

  10. Instability of Stratified Shear Flow: Intermittency and Length Scales

    NASA Astrophysics Data System (ADS)

    Ecke, Robert; Odier, Philippe

    2015-11-01

    The stability of stratified shear flows which occur in oceanic overflows, wind-driven thermoclines, and atmospheric inversion layers is governed by the Richardson Number Ri , a non-dimensional balance between stabilizing stratification and destabilizing shear. For a shear flow with velocity difference U, density difference Δρ and characteristic length H, one has Ri = g (Δρ / ρ) H /U2 . A more precise definition is the gradient Richardson Number Rig =N2 /S2 where the buoyancy frequency N =√{ (g / ρ) ∂ρ / ∂z } , the mean strain S = ∂U / ∂z with z parallel to gravity and with ensemble or time averages defining the gradients. We explore the stability and mixing properties of a wall-bounded shear flow for 0 . 1 < Rig < 1 using simultaneous measurements of density and velocity fields. The flow, confined from the top by a horizontal boundary, is a lighter alcohol-water mixture injected from a nozzle into quiescent heavier salt-water fluid. The injected flow is turbulent with Taylor Reynolds number about 75. We compare a set of length scales that characterize the mixing properties of our turbulent stratified shear flow including Thorpe Length LT, Ozmidov Length LO, and Ellison Length LE.

  11. Water and suspended sediment division at a stratified tidal junction

    NASA Astrophysics Data System (ADS)

    Buschman, F. A.; Vegt, M.; Hoitink, A. J. F.; Hoekstra, P.

    2013-03-01

    Tidal junctions play a crucial role in the transport of water, salt, and sediment through a delta distributary network. Water, salt and sediment are exchanged at tidal junctions, thereby influencing the transports in the connecting branches and the overall dynamics of the system. This paper presents observations of water, salt and sediment transports in three channels that connect at a stratified tidal junction. Flow variation in one channel was found to lag behind flow variation in a connected channel by more than 1 h, which is largely attributed to channel length differences from the junction to the sea. The water columns in the three channels were periodically stratified during spring tide, whereas the salinity structure represented a salt wedge during neap tide. Salinity differences between the three channels were substantial. The channels contain water bodies of different salinity and act largely independently. Flow velocities in the upper and lower layers differed substantially. Flow in the lower layer was generally in the direction of acceleration produced by the baroclinic pressure gradient. Interestingly, baroclinic pressure gradients were sometimes directed landward, indicating the presence of saltier water at the land side of the estuary. In sharp channel bends close to the junction, secondary flow was strongest at the highest axial flow velocity during spring tide. In one channel bend, these circulations steered the suspended sediment toward the inner bend, which affected the suspended sediment division.

  12. Sedimentation from Particle-Laden Plumes in Stratified Fluid

    NASA Astrophysics Data System (ADS)

    Sutherland, Bruce; Hong, Youn Sub

    2015-11-01

    Laboratory experiments are performed in which a mixture of particles, water and a small amount of dye is continuously injected upwards from a localized source into a uniformly stratified ambient. The particle-fluid mixture initially rises as a forced plume (which in most cases is buoyant, though in some cases due to high particle concentration is negative-buoyant at the source), reaches a maximum height, collapses upon itself and then spreads as a radial intrusion. The particles are observed to rain out of the descending intrusion and settle upon the floor of the tank. Using light attenuation, the depth of the particle mound is measured after the experiment has run for a fixed amount of time. In most experiments the distribution of particles is found to be approximately axisymmetric about the source with a near Gaussian structure for height as a function of radius. The results are compared with a code that combines classical plume theory with an adaptation to stratified fluids of the theory of Carey, Sigurdsson and Sparks (JGR, 1988) for the spread and fall of particles from a particle-laden plume impacting a rigid ceiling. Re-entrainment of particles into the plume is also taken into account.

  13. Effective mass discontinuity and current oscillations in stratified systems

    NASA Astrophysics Data System (ADS)

    Halilov, S.; Mil'shtein, S.

    2015-11-01

    Tunnelling transport in modulated film, which occurs either stoichiometrically or due to a stress field, is analysed in terms of the variable carrier effective mass tensor. It is shown that the mass tensor discontinuity alone, i.e. with no actual potential barrier present, may lead to current oscillations versus the size of the modulated region. While both effects of mass discontinuity and the band offset upon the carrier flow are formally described in terms of wave mechanics, their mechanisms are quite distinct: the magnitude of the current oscillations due to mass disruption is determined by the differential mass across the interface, i.e. by change in the covalency due to structural modulation, whereas the band offset is generally an effect of the affinity change across the interface. Both effects are superimposed by the 3D kinematic coupling of the orthogonal transport, either constructively or destructively, leading to an oscillatory dependence of the current magnitude on the film dimension. As an illustration, the analysis is applied to a Si1-x Ge x /Si stratified structure to demonstrate the effect of quasi-bound states on the transport. The modelling is corroborated by a device simulation of a SiGe system in a heterojunction bipolar transistor setting. The findings can be used as a general method to control anisotropic tunnelling transport in stratified structures.

  14. On Parameterizing Turbulence in the Stably Stratified Atmospheric Boundary Layer

    NASA Astrophysics Data System (ADS)

    Wilson, Jordan M.; Venayagamoorthy, Subhas K.

    2014-11-01

    Parameterizing turbulent mixing in the stably stratified atmospheric boundary layer remains an active area of research connecting available field measurements with appropriate model parameters. The research presented studies the pertinent mixing lengths for shear- and buoyancy-dominated (or weakly stable and very stable) regimes in the stable atmospheric boundary layer (SABL). Incorporating shear and buoyancy effects, two length scales can be constructed, LkS =k 1 / 2 / S and LkN =k 1 / 2 / N , respectively. Extending the conceptual framework of Mater & Venayagamoorthy (2014), LkS and LkN are shown to be accurate representations of large-scale motions from which relevant model parameters are developed using observations from three field campaigns. An a priori analysis of large-eddy simulation (LES) data evaluates the efficacy of parameterizations applied to the vertical structure of the SABL. The results of this study provide a thorough evaluation of the pertinent mixing lengths in stably stratified turbulence through applications to atmospheric observations and numerical models for the boundary layer extendable to larger-scale weather prediction or global circulation models. S.K.V. gratefully acknowledges the support of the National Science Foundation under Grant No. OCE-1151838.

  15. Turbulent plumes from ice melting into a linearly stratified ocean

    NASA Astrophysics Data System (ADS)

    Wells, Andrew; Magorrian, Samuel

    2015-11-01

    The melting of submerged marine glacier termini and ice shelves floating atop the ocean has important implications for ice sheet dynamics and sea level rise. When vertical or inclined ice faces melt into a warm salty ocean, the fresh meltwater rises in a buoyant plume along the ice-ocean interface and the resulting turbulent heat transfer provides a feedback on melting rates. We apply a turbulent plume model to consider the dynamics of well-mixed meltwater plumes rising along planar ice faces through a linearly stratified ocean, with vertical gradients of background ocean temperature and salinity. When the driving buoyancy force is dominated by salinity differences, the flow develops in a repeating series of layers, with the meltwater plume accelerating along the slope, rising past its neutral density level, and then separating from the ice face and intruding into the background ocean. We determine approximate scaling laws for the layer heights, melting rates and flow properties as a function of the background ocean temperature and salinity. These scaling laws provide a good collapse across a range of numerical solutions of the plume model, and may prove useful as a simple parameterisation of glacial melting in stratified Greenland fjords.

  16. Tidally-forced flow in a rotating, stratified, shoaling basin

    NASA Astrophysics Data System (ADS)

    Winters, Kraig B.

    2015-06-01

    Baroclinic flow of a rotating, stratified fluid in a parabolic basin is computed in response to barotropic tidal forcing using the nonlinear, non-hydrostatic, Boussinesq equations of motion. The tidal forcing is derived from an imposed, boundary-enhanced free-surface deflection that advances cyclonically around a central amphidrome. The tidal forcing perturbs a shallow pycnocline, sloshing it up and down over the shoaling bottom. Nonlinearities in the near-shore internal tide produce an azimuthally independent 'set-up' of the isopycnals that in turn drives an approximately geostrophically balanced, cyclonic, near-shore, sub-surface jet. The sub-surface cyclonic jet is an example of a slowly evolving, nearly balanced flow that is excited and maintained solely by forcing in the fast, super-inertial frequency band. Baroclinic instability of the nearly balanced jet and subsequent interactions between eddies produce a weak transfer of energy back into the inertia-gravity band as swirling motions with super-inertial vorticity stir the stratified fluid and spontaneously emit waves. The sub-surface cyclonic jet is similar in many ways to the poleward flows observed along eastern ocean boundaries, particularly the California Undercurrent. It is conjectured that such currents may be driven by the surface tide rather than by winds and/or along-shore pressure gradients.

  17. Lake Nasser and Toshka Lakes, Egypt

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Lake Nasser (center) and the Toshka Lakes (center left) glow emerald green and black in this MODIS true-color image acquired March 8, 2002. Located on and near the border of Egypt and Norther Sudan, these lakes are an oasis of water in between the Nubian (lower right) and Libyan Deserts (upper left). Also visible are the Red Sea (in the upper right) and the Nile River (running north from Lake Nasser). Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

  18. Thermal characteristics of Lake Michigan, 1954-55

    USGS Publications Warehouse

    Carr, John F.; Moffett, James W.; Gannon, John E.

    1973-01-01

    The thermal regime of Lake Michigan is described on the basis of the analysis of 1,671 bathythermograph casts made in 1954 and 1955. The beginning, duration, geographic extent, and ending of thermal stratification were determined from 51 thermal profiles from all areas of the open lake. The lake gained heat for about 5 months (mid-March to mid-August) and lost heat over the rest of the year. It was thermally stratified during much of the warming cycle and vertically isothermal during much of the cooling cycle. The annual warming period began by April and was well underway by mid-May. During the transitional period between the isothermal conditions of winter and the thermal stratification of summer, the rate of warming was relatively fast. Seasonal warming began in the shallow inshore waters, which were usually thermally stratified by mid to late May. Stratification persisted in the deeper offshore water into December. Maximum surface temperatures and highest average metalimnion temperatures were reached in early August. Local variations in water temperatures during stratification, however, were a common feature of the thermal characteristics of Lake Michigan. These sometimes sudden changes were caused by upwellings of cold bottom waters that in some instances affected areas of hundreds of square miles. During the warming period of 1954, the heat content of Lake Michigan increased an average of 425 gm-cal/cm??/day. The annual heat budget of the lake for 1954 was 51,700 calories which is similar to that reported for 1942 (50,000 calories) and 1943 (62,000 calories). Heat was lost from mid-August until March, at a rate of about 250 gm-cal/cm??/day. Seasonal thermal characteristics differed little between 1954 and 1955, and were similar to those observed during studies in 1941 and 1942.

  19. Molecular and isotopic insights into methane oxidation in Lake Kivu

    NASA Astrophysics Data System (ADS)

    Zigah, P. K.; Wehrli, B.; Schubert, C. J.

    2013-12-01

    Lake Kivu is a meromictic lake in the East African Rift Valley, located between the Republic of Rwanda and the Democratic Republic of Congo. The hypolimnion is permanently stratified and contain an unusually high amount of dissolved methane (CH4; ~ 60 km3) and carbon dioxide (CO2; ~300 km3) at standard temperature and pressure. While microbial-mediated methane oxidation is an important sink of methane in the lake, little is known about the distribution of microbes involved in the methane oxidation. To provide insights into methanotrophy in the lake, we analyzed depth profile of CH4, δ13C-CH4 and δ13C-DIC, δ13C-POC and the biomarkers of methanotrophic archaea and bacteria and their stable carbon isotopic composition from suspended particulate matter isolated from the lake water column. Our preliminary data show enhanced methane oxidation in oxic-anoxic transition zone in the water column. Depth distribution of diagnostic methanotrophic archaeal biomarkers such as archaeol and hydroxyarchaeol suggest archaea might be involved in anaerobic methane oxidation. Phospholipid fatty acids and diplopterol distribution and carbon isotopic signatures indicate bacteria-mediated anaerobic (and aerobic) methane oxidation in the lake.

  20. Calcite dissolution in two deep eutrophic lakes

    SciTech Connect

    Ramisch, F.; Dittrich, M.; Mattenberger, C.; Wehrli, B.; Wueest, A.

    1999-10-01

    The calcium cycle, in particular carbonate dissolution, was analyzed in two deep eutrophic lakes, Lago di Lugano (288 m maximum depth) and Sempachersee (87 m) located in Switzerland. A box model approach was used to calculate calcite dissolution in the water column and at the sediment-water interface based on various lake monitoring data such as sediment traps, sediment cores, water and pore-water interface based on various lake monitoring data such as sediment traps, sediment cores, water and pore-water analysis. A model for stationary conditions allowing the calculation of calcite dissolution in the water column for a given particle size distribution was developed. The relative values of the simulated flux were consistent with sediment trap observations. The best fit of the dissolution rate constant of sinking calcite in Lago di Lugano was on the same order of magnitude (3 {center{underscore}dot} 10{sup {minus}10} kg{sup 1/3} s{sup {minus}1}) as published laboratory values for this surface controlled process. Both lakes show a similar specific calcite precipitation rate of 170 g Ca m{sup {minus}2} a{sup {minus}1}. The diffusive flux across the sediment-water interface amounts to about 15 and 10% of total calcite precipitation in Sempachersee and Lago di Lugano, respectively. However, 61% of the precipitated calcite is dissolved in the water column of Lago di Lugano compared to only 13% in Sempachersee. These results point towards the importance of grain size distributions and settling times in stratified deep waters as the two most important factors determining calcite retention in sediments of hard water lakes.

  1. Pseudoepitheliomatous Hyperplasia in a Red Pigment Tattoo: A Separate Entity or Hypertrophic Lichen Planus-like Reaction?

    PubMed

    Kazlouskaya, Viktoryia; Junkins-Hopkins, Jacqueline M

    2015-12-01

    Red pigment tattoos are known to cause pseudoepitheliomatous hyperplasia in the skin, frequently simulating squamous cell carcinoma or keratoacanthoma. Herein, the authors present two additional cases of red pigment tattoo pseudoepitheliomatous hyperplasia in which they noted a lichenoid tissue reaction. They reviewed the previously published cases and observed a lichenoid reaction in the histopathological images similar to hypertrophic lichen planus. The authors suggest that these reactions might best be referred to as "lichenoid reaction with pseudoepitheliomatous hyperplasia" or "hypertrophic lichen planus-like reaction." Accordingly, recognition of an inflammatory component may allow additional treatment options. PMID:26705448

  2. Lake trout rehabilitation in Lake Ontario

    USGS Publications Warehouse

    Elrod, Joseph H.; O'Gorman, Robert; Schneider, Clifford P.; Eckert, Thomas H.; Schaner, Ted; Bowlby, James N.; Schleen, Larry P.

    1995-01-01

    Attempts to maintain the native lake trout (Salvelinus namaycush) population in Lake Ontario by stocking fry failed and the species was extirpated by the 1950s. Hatchery fish stocked in the 1960s did not live to maturity because of sea lamprey (Petromyzon marinus) predation and incidental commercial harvest. Suppression of sea lampreys began with larvicide treatments of Lake Ontario tributaries in 1971 and was enhanced when the tributaries of Oneida Lake and Lake Erie were treated in the 1980s. Annual stocking of hatchery fish was resumed with the 1972 year class and peaked at about 1.8 million yearlings and 0.3 million fingerlings from the 1985–1990 year classes. Survival of stocked yearlings declined over 50% in the 1980 s and was negatively correlated with the abundance of lake trout > 550 mm long (r = −0.91, P < 0.01, n = 12). A slot length limit imposed by the State of New York for the 1988 fishing season reduced angler harvest. Angler harvest in Canadian waters was 3 times higher in eastern Lake Ontario than in western Lake Ontario. For the 1977–1984 year classes, mean annual survival rate of lake trout age 6 and older was 0.45 (range: 0.35–0.56). In U.S. waters during 1985–1992, the total number of lake trout harvested by anglers was about 2.4 times greater than that killed by sea lampreys. The number of unmarked lake trout < 250 mm long in trawl catches in 1978–1992 was not different from that expected due to loss of marks and failure to apply marks at the hatchery, and suggested that recruitment of naturally-produced fish was nil. However, many of the obstacles which may have impeded lake trout rehabilitation in Lake Ontario during the 1980s are slowly being removed, and there are signs of a general ecosystem recovery. Significant recruitment of naturally produced lake trout by the year 2000, one interim objective of the rehabilitation plan for the Lake, may be achieved.

  3. Lakes Ecosystem Services Online

    EPA Science Inventory

    Northeastern lakes provide valuable ecosystem services that benefit residents and visitors and are increasingly important for provisioning of recreational opportunities and amenities. Concurrently, however, population growth threatens lakes by, for instance, increasing nutrient ...

  4. Utah: Salt Lake Region

    Atmospheric Science Data Center

    2014-05-15

    article title:  Winter and Summer Views of the Salt Lake Region     View Larger Image Magnificent views of the region surrounding Salt Lake City, Utah are captured in these winter and summer images from the ...

  5. Assessment of improvement scenario for water quality in Mogan Lake by using the AQUATOX Model.

    PubMed

    Akkoyunlu, Atilla; Karaaslan, Yakup

    2015-09-01

    In this study, the improvement scenarios for water quality in Mogan Lake were investigated using the AQUATOX Model. The ecosystem model AQUATOX simulates conventional pollutants, such as nutrients and sediments, and considers several trophic levels, including attached and planktonic algae, submerged aquatic vegetation, several types of invertebrates, and several types of fish. In this study, all data measured at both lakes and creeks was loaded into the AQUATOX Model including both initial concentration and dynamic loading for the year 2002. Then, the AQUATOX Model was calibrated and verified for the years 2004 and 2005. Accordingly, the Aquatox Model was utilized for the analysis of future scenarios as to improve water quality in terms of conventional parameters such as dissolved oxygen, temperature, total suspended solids, pH, total nitrogen, total phosphorus, and labile and refractory organic matters in water colon and sediment. During the development of future scenarios, some plans regarding measures were taken into account the modeling periods. In one of the scenarios, constructed wetlands located in big creeks' mouths were used for improving the water quality in Mogan Lake. The results indicated that Mogan Lake would improve its hypertrophic situation towards eutrophic situation. It would be anticipated that if the situation goes on like this, Mogan Lake would improve eutrophic situation towards mezotrophic situation. PMID:26257116

  6. Lake Borullus of the Nile Delta: a short history and an uncertain future.

    PubMed

    Dumont, Henri J; El-Shabrawy, Gamal M

    2007-12-01

    Borullus, the most centrally situated of the Nile Delta lakes, probably evolved around the eighth century AD from a preexisting salt marsh by fluviatile deposition of sand dunes north of the lake and subsidence of the preexisting tidal swamp behind this barrier. It was flooded yearly (September-December) by the Sebennytic branch of the Nile, and evacuated water through an exit, Bughaz. At low river levels, this process reversed and Bughaz functioned as a marine inlet. Because of this switch, its fauna and flora contained a mix of marine, freshwater, and brackish-water species. Around the mid-nineteenth century, damming of the Nile began, culminating with the high Aswan Dam (1964) that brought the yearly flood fully under control. As a result, a steady flow of Nile water, used for irrigated delta agriculture, began to drain to the lake and became a constant evacuator to the Mediterranean. It turned almost fresh, and its fishery, formerly marine and mullet-based, became cichlid-catfish based. However, rice and other new delta crops caused huge amounts of nutrients to wash down the drains, and currently the lake is eutrophied and only resists hypertrophication because of the low residence time of its water. Finally, the damming of the Nile terminated the influx to the delta of a yearly sediment layer, but subsidence and coastal erosion continue and are now consuming the sand bar that separates the lake from the sea.

  7. Assessment of improvement scenario for water quality in Mogan Lake by using the AQUATOX Model.

    PubMed

    Akkoyunlu, Atilla; Karaaslan, Yakup

    2015-09-01

    In this study, the improvement scenarios for water quality in Mogan Lake were investigated using the AQUATOX Model. The ecosystem model AQUATOX simulates conventional pollutants, such as nutrients and sediments, and considers several trophic levels, including attached and planktonic algae, submerged aquatic vegetation, several types of invertebrates, and several types of fish. In this study, all data measured at both lakes and creeks was loaded into the AQUATOX Model including both initial concentration and dynamic loading for the year 2002. Then, the AQUATOX Model was calibrated and verified for the years 2004 and 2005. Accordingly, the Aquatox Model was utilized for the analysis of future scenarios as to improve water quality in terms of conventional parameters such as dissolved oxygen, temperature, total suspended solids, pH, total nitrogen, total phosphorus, and labile and refractory organic matters in water colon and sediment. During the development of future scenarios, some plans regarding measures were taken into account the modeling periods. In one of the scenarios, constructed wetlands located in big creeks' mouths were used for improving the water quality in Mogan Lake. The results indicated that Mogan Lake would improve its hypertrophic situation towards eutrophic situation. It would be anticipated that if the situation goes on like this, Mogan Lake would improve eutrophic situation towards mezotrophic situation.

  8. Seasonal changes of methane concentration in boreal lakes of NW Russia

    NASA Astrophysics Data System (ADS)

    Zabelina, Svetlana; Desmukh, Chandrashekhar; Pokrovsky, Oleg; Savvichev, Alexander; Shirokova, Liudmila; Guerin, Frederic; Zakharova, Elena

    2010-05-01

    Methane (CH4), produced by methanogenic Archaea under strictly anoxic conditions in sediments, is an important atmospheric greenhouse gas, contributing to global warming. Besides, the importance of boreal lakes in global methane evaluation stem from the high coverage of arctic and subarctic land surface by lakes of glacial or thermokarst origin. The first step in the evaluation of methane biogeochemical cycle in high latitudes is the measurement of its concentration in the water column and bottom porewater sediments. In this work, we investigated several typical seasonally stratified lakes in Arkhnagelsk region of the NW Russia. Methane concentrations profiles were measured in the water column and sediment porewaters of two lakes of the Kenozersky National Park (KNP) (Lake Maselgskoe and Lake Vilno) located in the middle of taiga zone southwest from Arkhangelsk, and the lake Svjatoe located in the Geobiopsheric station "Rotkovetz" during the summer (2007, 2009) and winter (2008) stratification period. In addition, the lake Maselgskoe was studied during spring and autumn water overturn. During summer period, methane profiles in the lake Maselgskoe showed three zones with differed CH4 concentration: constant concentration around 0.22 µmol/L in the surface layer (0 to 6-7 m), then gradual decrease to 0.05 μmol/L (8 to 15 m) and significant increase to 80 μmol/L in near-bottom water. During autumn lake water overturn, mean СН4 concentration (0.31 µmol/L) in the water column of the lake Maselgskoe gradually but decreased insignificant from the surface to depth horizons. Stratified lake Svyatoe in 2007 and shallow lake Vilno in 2009 demonstrated similar features of CH4 concentration profile, however near-bottom concentration in lakes was an order of magnitude less than in Maselgskoe. The sediment porewaters of stratified lakes exhibit the concentration of methane ranging from 0.43 to 2.0 mmol/L in summer and from 1 to 2.4 mmol/L in winter in lake Maselgskoe and

  9. Axisymmetric modes in vertically stratified self-gravitating discs

    NASA Astrophysics Data System (ADS)

    Mamatsashvili, G. R.; Rice, W. K. M.

    2010-08-01

    We carry out a linear analysis of the vertical normal modes of axisymmetric perturbations in stratified, compressible, self-gravitating gaseous discs in the shearing-box approximation. An unperturbed disc has a polytropic vertical structure that allows us to study specific dynamics for subadiabatic, adiabatic and superadiabatic vertical stratifications, by simply varying the polytropic index. In the absence of self-gravity, four well-known principal modes can be identified in a stratified disc: acoustic p modes, surface gravity f modes, buoyancy g modes and inertial r modes. After classifying and characterizing modes in the non-self-gravitating case, we include self-gravity in the perturbation equations and in the equilibrium and investigate how it modifies the properties of these four modes. We find that self-gravity, to a certain degree, reduces their frequencies and changes the structure of the dispersion curves and eigenfunctions at radial wavelengths comparable to the disc height. Its influence on the basic branch of the r mode, in the case of subadiabatic and adiabatic stratifications, and on the basic branch of the g mode, in the case of superadiabatic stratification (which in addition exhibits convective instability), does appear to be strongest. Reducing the 3D Toomre's parameter Q3D results in the latter modes becoming unstable due to self-gravity, so that they determine the onset criterion and nature of the gravitational instability of a vertically stratified disc. By contrast, the p, f and convectively stable g modes, although their corresponding ω2 are reduced by self-gravity, never become unstable however small the value of Q3D. This is a consequence of the three dimensionality of the disc. The eigenfunctions corresponding to the gravitationally unstable modes are intrinsically three dimensional. We also contrast the more exact instability criterion based on our 3D model with that of density waves in 2D (razor-thin) discs. Based on these findings, we

  10. Gas bursts from cameroon crater lakes: a new natural hazard.

    PubMed

    Sigurdsson, H

    1988-06-01

    Gas bursts from tropical crater lakes constitute a hitherto unrecognized natural hazard, which claimed 37 lives around Lake Monoun in 1984 and 1,746 lives in 1986 around Lake Nyos in Cameroon, west Africa. Studies of these events indicate that the lethal gas clouds were dominantly CO(2) which exsolved catastrophically from deep waters of the lakes, producing in the case of Lake Nyos a gas cloud of 1.94 times 10(6) tons CO(2) . Carbon-isotope data indicate a magmatic source of the carbon dioxide, but the geochemistry of deep water and gases does not support a sudden injection of volcanic gas from a deep source into the lakes. Rather, it is proposed that the gas bursts were preceded by gradual build-up of dissolved bicarbonate in deep waters, where anoxic conditions in enclosed and stagnant basins led to low pH and pCO(2) close to saturation. Steady input from the Earth's mantle to submerged mofettes or CO(2) -rich soda springs within the lakes is most likely the primary source of carbon dioxide. Lethal effects of the gas bursts are almost entirely due to CO(2) -induced asphyxia. A small percentage of victims awoke from coma one or two days after the event, but most died. Unusual skin lesions on about 5% of victims arose from the comatose state. It is shown that the mass of gas required to account for the lethal effects and observed gas clouds is an order of magnitude less than the potential gas yield from the lakes. In view of the lethal gas bursts from the small Cameroon lakes, the potential hazard of future gas bursts from other much larger density-stratified equatorial lakes must be seriously considered, particularly in Lake Kivu in east Africa, where methane and carbon dioxide gas content is higher by two to four orders of magnitude than that of the Cameroon lakes. A gas burst from Lake Kivu would form a carbon dioxide cloud up to 340 km(3) in volume and expansion of the exsolving gas from deep water to atmospheric pressure would correspond to an energy release

  11. Gas bursts from cameroon crater lakes: a new natural hazard.

    PubMed

    Sigurdsson, H

    1988-06-01

    Gas bursts from tropical crater lakes constitute a hitherto unrecognized natural hazard, which claimed 37 lives around Lake Monoun in 1984 and 1,746 lives in 1986 around Lake Nyos in Cameroon, west Africa. Studies of these events indicate that the lethal gas clouds were dominantly CO(2) which exsolved catastrophically from deep waters of the lakes, producing in the case of Lake Nyos a gas cloud of 1.94 times 10(6) tons CO(2) . Carbon-isotope data indicate a magmatic source of the carbon dioxide, but the geochemistry of deep water and gases does not support a sudden injection of volcanic gas from a deep source into the lakes. Rather, it is proposed that the gas bursts were preceded by gradual build-up of dissolved bicarbonate in deep waters, where anoxic conditions in enclosed and stagnant basins led to low pH and pCO(2) close to saturation. Steady input from the Earth's mantle to submerged mofettes or CO(2) -rich soda springs within the lakes is most likely the primary source of carbon dioxide. Lethal effects of the gas bursts are almost entirely due to CO(2) -induced asphyxia. A small percentage of victims awoke from coma one or two days after the event, but most died. Unusual skin lesions on about 5% of victims arose from the comatose state. It is shown that the mass of gas required to account for the lethal effects and observed gas clouds is an order of magnitude less than the potential gas yield from the lakes. In view of the lethal gas bursts from the small Cameroon lakes, the potential hazard of future gas bursts from other much larger density-stratified equatorial lakes must be seriously considered, particularly in Lake Kivu in east Africa, where methane and carbon dioxide gas content is higher by two to four orders of magnitude than that of the Cameroon lakes. A gas burst from Lake Kivu would form a carbon dioxide cloud up to 340 km(3) in volume and expansion of the exsolving gas from deep water to atmospheric pressure would correspond to an energy release

  12. Great Minds? Great Lakes!

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Chicago, IL. Great Lakes National Program Office.

    This book contains lesson plans that provide an integrated approach to incorporating Great Lakes environmental issues into elementary subjects. The book is divided into three subject areas: (1) History, which includes the origins of the Great Lakes, Great Lakes people, and shipwrecks; (2) Social Studies, which covers government, acid rain as a…

  13. A Killer Lake

    ERIC Educational Resources Information Center

    Horvath, Thomas

    2005-01-01

    In 1986, Lake Nyos, a volcanic lake in Cameroon, released a huge amount of carbon dioxide gas, killing over 1,700 people in the surrounding area. This case study, developed for use in a limnology or aquatic biology course, explores that event, introducing students to concepts relating to lake formation, thermal stratification, and dissolved gases.…

  14. Great Lakes: Chemical Monitoring

    ERIC Educational Resources Information Center

    Delfino, Joseph J.

    1976-01-01

    The Tenth Great Lakes Regional Meeting of the American Chemical Society met to assess current Chemical Research activity in the Great Lakes Basin, and addressed to the various aspects of the theme, Chemistry of the Great Lakes. Research areas reviewed included watershed studies, atmospheric and aquatic studies, and sediment studies. (BT)

  15. Lake Layers: Stratification.

    ERIC Educational Resources Information Center

    Brothers, Chris; And Others

    This teacher guide and student workbook set contains two learning activities, designed for fifth through ninth grade students, that concentrate on lake stratification and water quality. In the activities students model the seasonal temperature changes that occur in temperate lakes and observe the resulting stratification of lake waters. Students…

  16. New treatment strategies for hypertrophic obstructive cardiomyopathy: alcohol ablation of the septum: the new gold standard?

    PubMed

    Hess, Otto M; Sigwart, Ulrich

    2004-11-16

    Hypertrophic cardiomyopathy is a primary myocardial disorder with an autosomal pattern of inheritance characterized by inappropriate myocardial hypertrophy. Annual mortality has been reported to be 1% to 2% and sudden death represents the most common cause. Treatment strategies are 1) medical therapy in patients with mild to moderate symptoms, 2) reduction of septal hypertrophy by surgical myectomy or alcohol ablation, and 3) implantation of an automatic cardioverter-defibrillator in the presence of non-sustained ventricular tachyarrhythmias. A debate has been started on whether surgical myectomy or alcohol ablation of the septum is the appropriate treatment for hypertrophic obstructive cardiomyopathy. Surgical (transaortic) myectomy has been the gold standard in the past 20 to 30 years for treatment of symptomatic patients with significant hemodynamic outflow tract obstruction. However, modern interventional technologies allow reduction of the myocardial septum by injection of alcohol into the first or second septal branch under guidance of two-dimensional (2D)-contrast echocardiography. This percutaneous technique not only has a lower morbidity than surgical myectomy but can be guided precisely by 2D echocardiography. One potential complication is transient (<30%) or permanent (<10%) atrioventricular block III; however, this complication is relatively rare. A randomized trial comparing the two treatment modalities is lacking, and the chance is small that such a trial will be performed because alcohol ablation can be done with high success and low complication rates, leaving only complex interventions (with valvular reconstructions and so on) for surgical myectomy.

  17. Percutaneous Septal Ablation in Hypertrophic Obstructive Cardiomyopathy: From Experiment to Standard of Care

    PubMed Central

    Faber, Lothar

    2014-01-01

    Hypertrophic cardiomyopathy (HCM) is one of the more common hereditary cardiac conditions. According to presence or absence of outflow obstruction at rest or with provocation, a more common (about 60–70%) obstructive type of the disease (HOCM) has to be distinguished from the less common (30–40%) nonobstructive phenotype (HNCM). Symptoms include exercise limitation due to dyspnea, angina pectoris, palpitations, or dizziness; occasionally syncope or sudden cardiac death occurs. Correct diagnosis and risk stratification with respect to prophylactic ICD implantation are essential in HCM patient management. Drug therapy in symptomatic patients can be characterized as treatment of heart failure with preserved ejection fraction (HFpEF) in HNCM, while symptoms and the obstructive gradient in HOCM can be addressed with beta-blockers, disopyramide, or verapamil. After a short overview on etiology, natural history, and diagnostics in hypertrophic cardiomyopathy, this paper reviews the current treatment options for HOCM with a special focus on percutaneous septal ablation. Literature data and the own series of about 600 cases are discussed, suggesting a largely comparable outcome with respect to procedural mortality, clinical efficacy, and long-term outcome. PMID:26556411

  18. Virtual Cardiac Surgery Using CFD: Application to Septal Myectomy in Obstructive Hypertrophic Cardiomyopathy

    NASA Astrophysics Data System (ADS)

    Vedula, Vijay; Mittal, Rajat; Abraham, Theodore

    2011-11-01

    Obstructive hypertrophic cardiomyopathy (HOCM) is characterized by ventricular wall thickening, diastolic dysfunction, and dynamic outflow tract obstruction, all of which strongly influence the vortex dynamics and pressure distribution in the left ventricle (LV). Severe cases of HCM are usually managed through septal myectomy where the surgeon resects the hypertrophic mass. Surgeons currently try to remove as much tissue as possible in order to optimize the post surgical result. However, excessive debulking increases the chance of ventricular septal defects, bundle branch block or complete heart block, and aneurysmal septal thinning. On the other hand, insufficient tissue removal also leads to unsatisfactory outcomes in terms of reduction of outflow tract pressure gradient. Knowing how much muscle to remove and where to remove it from could reduce the likelihood of complications and suboptimal outcomes. In the present study, we employ an immersed boundary solver to model the effect of septal myectomy for ventricles with HOCM and demonstrate the potential of such an approach for surgical planning. Computational resources were provided by the National Institute of Computational Science under Tergrid grant number TG-CTS100002.

  19. Prostaglandin E2 inhibits collagen synthesis in dermal fibroblasts and prevents hypertrophic scar formation in vivo.

    PubMed

    Zhao, Jingling; Shu, Bin; Chen, Lei; Tang, Jinming; Zhang, Lijun; Xie, Julin; Liu, Xusheng; Xu, Yingbin; Qi, Shaohai

    2016-08-01

    Hypertrophic scarring is a common dermal fibroproliferative disorder characterized by excessive collagen deposition. Prostaglandin E2 (PGE2 ), an important inflammatory product synthesized via the arachidonic acid cascade, has been shown to act as a fibroblast modulator and to possess antifibroblastic activity. However, the mechanism underlying the antifibrotic effect of PGE2 remains unclear. In this study, we explored the effects of PGE2 on TGF-β1-treated dermal fibroblasts in terms of collagen production and to determine the regulatory pathways involved, as well as understand the antiscarring function of PGE2 in vivo. We found that PGE2 inhibited TGF-β1-induced collagen synthesis by regulating the balance of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP). It did so by upregulating cAMP through the E prostanoid (EP)2 receptor. We determined that inhibition of the TGF-β1/Smad pathway by PGE2 is associated with its ability to inhibit collagen synthesis. An in vivo study further confirmed that PGE2 inhibits hypertrophic scar formation by decreasing collagen production. Our results demonstrate that the novel anti-scarring function of PGE2 is achieved by balancing MMPs/TIMP expression and decreasing collagen production. PMID:26997546

  20. Hypoxia-driven glycolytic and fructolytic metabolic programs: Pivotal to hypertrophic heart disease.

    PubMed

    Mirtschink, Peter; Krek, Wilhelm

    2016-07-01

    Pathologic cardiac growth is an adaptive response of the myocardium to various forms of systemic (e.g. pressure overload) or genetically-based (e. g. mutations in genes encoding sarcomeric proteins) stress. It represents a key aspect of different types of heart disease including aortic stenosis (AS) and hypertrophic cardiomyopathy (HCM). While many of the pathophysiological and hemodynamical aspects of pathologic cardiac hypertrophy have been uncovered during the last decades, its underlying metabolic determinants are only beginning to come into focus. Here, we review the epidemiological evidence and pathological features of hypertrophic heart disease in AS and HCM and consider in this context the development of microenvironmental tissue hypoxia as a key component of the heart's growth response to pathologic stress. We particularly reflect on recent evidence illustrating how activation of hypoxia-inducible factor (HIF) drives glycolytic and fructolytic metabolic programs to maintain ATP generation and support anabolic growth of the pathologically-stressed heart. Finally we discuss how this metabolic programs, when protracted, deprive the heart of energy leading ultimately to heart failure. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.

  1. Influence of verapamil therapy on left ventricular performance at rest and during exercise in hypertrophic cardiomyopathy.

    PubMed

    Hanrath, P; Schlüter, M; Sonntag, F; Diemert, J; Bleifeld, W

    1983-09-01

    To determine the hemodynamic effect of verapamil at rest and during exercise, 18 patients with hypertrophic cardiomyopathy were studied before and after 7 weeks of treatment with oral verapamil (maximal dose, 720 mg/day). At rest and at peak exercise, verapamil produced a significant increase in left ventricular (LV) systolic performance in terms of stroke volume index (rest, from 43 +/- 11 to 53 +/- 11 ml/m2, p less than 0.001; exercise, from 46 +/- 11 to 51 +/- 10 ml/m2, p less than 0.01), whereas heart rate decreased (rest, from 81 +/- 14 to 70 +/- 11 min-1, p less than 0.001; exercise, from 150 +/- 21 to 141 +/- 18 min-1, p less than 0.01). Cardiac index at rest and during exercise remained unchanged. Systolic vascular resistance did not change at rest, but decreased significantly during exercise (974 +/- 243 to 874 +/- 174 dynes s cm-5; p less than 0.05). After verapamil administration, pulmonary artery pressures did not change at rest, but decreased significantly during exercise. This was probably due to a shift in the LV pressure-volume relation. The improvement in LV hemodynamics was associated with a significant increase in exercise capacity. The findings of this study indicate that in patients with hypertrophic cardiomyopathy, hemodynamic improvement at rest and during exercise can be achieved by chronic administration of verapamil.

  2. Tetrandrine induces microRNA differential expression in human hypertrophic scar fibroblasts in vitro.

    PubMed

    Ning, P; Peng, Y; Liu, D W; Hu, Y H; Liu, Y; Liu, D M

    2016-01-01

    MicroRNAs (miRNAs) have recently been shown to play a role in normal wound healing process. miRNAs may be linked to pathologic wound healing and closely related to the formation of hypertrophic scars. This study aimed to explore the effects of tetrandrine on the miRNA expression profile in human hypertrophic scar fibroblasts (HSFs) in vitro. HSFs were randomly divided into two groups: the tetrandrine treatment group and the control group. The experimental and control groups were collected and analyzed by miRNA array after a 48-h culture. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to confirm the array results. The targets of differentially expressed miRNA were functionally annotated using bioinformatic approaches. miRNA microarray analysis identified 193 differentially expressed miRNAs and the expression of 186 miRNAs in the experimental group decreased while that of 7 miRNAs increased compared to the control group. The most significantly downregulated miRNA was hsa-miR-1246, and hsa-miR-27b had the highest expression level. Significant differentially expressed miRNAs were predicted to be related to several important signaling pathways related to scar wound healing. The differential miRNA expression identified in this study provides the experimental basis for further understanding the anti-fibrosis effect of tetrandrine. PMID:26909951

  3. Comparison between Stromal Vascular Fraction and Adipose Mesenchymal Stem Cells in Remodeling Hypertrophic Scars

    PubMed Central

    Maumus, Marie; Toupet, Karine; Frouin, Eric; Rigau, Valérie; Vozenin, Marie-Catherine; Magalon, Guy; Jorgensen, Christian; Noël, Danièle

    2016-01-01

    Hypertrophic scars (HTS) are characterized by excessive amount of collagen deposition and principally occur following burn injuries or surgeries. In absence of effective treatments, the use of mesenchymal stem/stromal cells, which have been shown to attenuate fibrosis in various applications, seems of interest. The objectives of the present study were therefore to evaluate the effect of human adipose tissue-derived mesenchymal stem cells (hASC) on a pre-existing HTS in a humanized skin graft model in Nude mice and to compare the efficacy of hASCs versus stromal vascular fraction (SVF). We found that injection of SVF or hASCs resulted in an attenuation of HTS as noticed after clinical evaluation of skin thickness, which was associated with lower total collagen contents in the skins of treated mice and a reduced dermis thickness after histological analysis. Although both SVF and hASCs were able to significantly reduce the clinical and histological parameters of HTS, hASCs appeared to be more efficient than SVF. The therapeutic effect of hASCs was attributed to higher expression of TGFβ3 and HGF, which are important anti-fibrotic mediators, and to higher levels of MMP-2 and MMP-2/TIMP-2 ratio, which reflect the remodelling activity responsible for fibrosis resorption. These results demonstrated the therapeutic potential of hASCs for clinical applications of hypertrophic scarring. PMID:27227960

  4. Comparison between Stromal Vascular Fraction and Adipose Mesenchymal Stem Cells in Remodeling Hypertrophic Scars.

    PubMed

    Domergue, Sophie; Bony, Claire; Maumus, Marie; Toupet, Karine; Frouin, Eric; Rigau, Valérie; Vozenin, Marie-Catherine; Magalon, Guy; Jorgensen, Christian; Noël, Danièle

    2016-01-01

    Hypertrophic scars (HTS) are characterized by excessive amount of collagen deposition and principally occur following burn injuries or surgeries. In absence of effective treatments, the use of mesenchymal stem/stromal cells, which have been shown to attenuate fibrosis in various applications, seems of interest. The objectives of the present study were therefore to evaluate the effect of human adipose tissue-derived mesenchymal stem cells (hASC) on a pre-existing HTS in a humanized skin graft model in Nude mice and to compare the efficacy of hASCs versus stromal vascular fraction (SVF). We found that injection of SVF or hASCs resulted in an attenuation of HTS as noticed after clinical evaluation of skin thickness, which was associated with lower total collagen contents in the skins of treated mice and a reduced dermis thickness after histological analysis. Although both SVF and hASCs were able to significantly reduce the clinical and histological parameters of HTS, hASCs appeared to be more efficient than SVF. The therapeutic effect of hASCs was attributed to higher expression of TGFβ3 and HGF, which are important anti-fibrotic mediators, and to higher levels of MMP-2 and MMP-2/TIMP-2 ratio, which reflect the remodelling activity responsible for fibrosis resorption. These results demonstrated the therapeutic potential of hASCs for clinical applications of hypertrophic scarring.

  5. Fibroproliferative effect of microRNA-21 in hypertrophic scar derived fibroblasts.

    PubMed

    Li, Guangzao; Zhou, Renpeng; Zhang, Qi; Jiang, Banghong; Wu, Qingkai; Wang, Chen

    2016-07-01

    Hypertrophic scar (HS) is a fibroproliferative disorder caused by abnormal wound healing, which is characterized by excessive deposition of extracellular matrix (ECM) secreted by fibroblasts. We previous have found that expression of microRNA-21(miR-21) was increased in tissues and fibroblasts of HS. However, the underlying molecular mechanism remains to be further elucidated. In this study, we identified the miR-21 was a marker for the phenotype of HS fibroblasts, as anti-miR-21 reduced expression of fibrosis markers such as Col1A1, Col3A1, Fn and α-SMA in fibroblasts and overexpression of miR-21 promoted fibroproliferative expression in fibroblasts. Furthermore, we also found that miR-21 promoted TGF-β1 induced fibroproliferative expression by repressing Smad7 expression in vitro. In addition, the miR-21 inhibitor inhibited the growth of hypertrophic scar tissue in vivo (nude mice experimental model). These results indicated that miR-21 was a critical regulator for HS formation and TGF- β1/miR-21/Smad7 pathway could be a useful therapeutic target for the treatment of HS. PMID:27207585

  6. TGF-β1 mediates the hypertrophic cardiomyocyte growth induced by angiotensin II

    PubMed Central

    Schultz, Jo El J.; Witt, Sandra A.; Glascock, Betty J.; Nieman, Michelle L.; Reiser, Peter J.; Nix, Stacey L.; Kimball, Thomas R.; Doetschman, Thomas

    2002-01-01

    Angiotensin II (Ang II), a potent hypertrophic stimulus, causes significant increases in TGFb1 gene expression. However, it is not known whether there is a causal relationship between increased levels of TGF-β1 and cardiac hypertrophy. Echocardiographic analysis revealed that TGF-β1–deficient mice subjected to chronic subpressor doses of Ang II had no significant change in left ventricular (LV) mass and percent fractional shortening during Ang IItreatment. In contrast, Ang II–treated wild-type mice showed a >20% increase in LV mass and impaired cardiac function. Cardiomyocyte cross-sectional area was also markedly increased in Ang II–treated wild-type mice but unchanged in Ang II–treated TGF-β1–deficient mice. No significant levels of fibrosis, mitotic growth, or cytokine infiltration were detected in Ang II–treated mice. Atrial natriuretic factor expression was ∼6-fold elevated in Ang II–treated wild-type, but not TGF-β1–deficient mice. However, the α- to β-myosin heavy chain switch did not occur in Ang II–treated mice, indicating that isoform switching is not obligatorily coupled with hypertrophy or TGF-β1. The Ang IIeffect on hypertrophy was shown not to result from stimulation of the endogenous renin-angiotensis system. These results indicate that TGF-β1 is an important mediator of the hypertrophic growth response of the heart to Ang II. PMID:11901187

  7. Hypoxia-driven glycolytic and fructolytic metabolic programs: Pivotal to hypertrophic heart disease.

    PubMed

    Mirtschink, Peter; Krek, Wilhelm

    2016-07-01

    Pathologic cardiac growth is an adaptive response of the myocardium to various forms of systemic (e.g. pressure overload) or genetically-based (e. g. mutations in genes encoding sarcomeric proteins) stress. It represents a key aspect of different types of heart disease including aortic stenosis (AS) and hypertrophic cardiomyopathy (HCM). While many of the pathophysiological and hemodynamical aspects of pathologic cardiac hypertrophy have been uncovered during the last decades, its underlying metabolic determinants are only beginning to come into focus. Here, we review the epidemiological evidence and pathological features of hypertrophic heart disease in AS and HCM and consider in this context the development of microenvironmental tissue hypoxia as a key component of the heart's growth response to pathologic stress. We particularly reflect on recent evidence illustrating how activation of hypoxia-inducible factor (HIF) drives glycolytic and fructolytic metabolic programs to maintain ATP generation and support anabolic growth of the pathologically-stressed heart. Finally we discuss how this metabolic programs, when protracted, deprive the heart of energy leading ultimately to heart failure. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel. PMID:26896647

  8. Fibroproliferative effect of microRNA-21 in hypertrophic scar derived fibroblasts.

    PubMed

    Li, Guangzao; Zhou, Renpeng; Zhang, Qi; Jiang, Banghong; Wu, Qingkai; Wang, Chen

    2016-07-01

    Hypertrophic scar (HS) is a fibroproliferative disorder caused by abnormal wound healing, which is characterized by excessive deposition of extracellular matrix (ECM) secreted by fibroblasts. We previous have found that expression of microRNA-21(miR-21) was increased in tissues and fibroblasts of HS. However, the underlying molecular mechanism remains to be further elucidated. In this study, we identified the miR-21 was a marker for the phenotype of HS fibroblasts, as anti-miR-21 reduced expression of fibrosis markers such as Col1A1, Col3A1, Fn and α-SMA in fibroblasts and overexpression of miR-21 promoted fibroproliferative expression in fibroblasts. Furthermore, we also found that miR-21 promoted TGF-β1 induced fibroproliferative expression by repressing Smad7 expression in vitro. In addition, the miR-21 inhibitor inhibited the growth of hypertrophic scar tissue in vivo (nude mice experimental model). These results indicated that miR-21 was a critical regulator for HS formation and TGF- β1/miR-21/Smad7 pathway could be a useful therapeutic target for the treatment of HS.

  9. Sex dimorphisms of crossbridge cycling kinetics in transgenic hypertrophic cardiomyopathy mice.

    PubMed

    Birch, Camille L; Behunin, Samantha M; Lopez-Pier, Marissa A; Danilo, Christiane; Lipovka, Yulia; Saripalli, Chandra; Granzier, Henk; Konhilas, John P

    2016-07-01

    Familial hypertrophic cardiomyopathy (HCM) is a disease of the sarcomere and may lead to hypertrophic, dilated, restrictive, and/or arrhythmogenic cardiomyopathy, congestive heart failure, or sudden cardiac death. We hypothesized that hearts from transgenic HCM mice harboring a mutant myosin heavy chain increase the energetic cost of contraction in a sex-specific manner. To do this, we assessed Ca(2+) sensitivity of tension and crossbridge kinetics in demembranated cardiac trabeculas from male and female wild-type (WT) and HCM hearts at an early time point (2 mo of age). We found a significant effect of sex on Ca(2+) sensitivity such that male, but not female, HCM mice displayed a decrease in Ca(2+) sensitivity compared with WT counterparts. The HCM transgene and sex significantly impacted the rate of force redevelopment by a rapid release-restretch protocol and tension cost by the ATPase-tension relationship. In each of these measures, HCM male trabeculas displayed a gain-of-function when compared with WT counterparts. In addition, cardiac remodeling measured by echocardiography, histology, morphometry, and posttranslational modifications demonstrated sex- and HCM-specific effects. In conclusion, female and male HCM mice display sex dimorphic crossbridge kinetics accompanied by sex- and HCM-dependent cardiac remodeling at the morphometric, histological, and cellular level.

  10. Supraventricular tachycardia in a patient with Lown-Ganong-Levine syndrome associated with apical hypertrophic cardiomyopathy.

    PubMed

    Hayano, M; Imamura, Y; Tsuruta, M; Inoue, J; Nakashima, H; Fukuyama, K; Eguchi, Y; Tsuji, S; Matsuo, S; Yano, K

    1988-03-01

    Electrophysiologic study of a 55-year-old patient with Lown-Ganong-Levine syndrome associated with apical hypertrophic cardiomyopathy is reported. The patient had a history of recurrent attacks of tachyarrhythmia and his electrocardiogram showed a short P-R interval (0.10 sec) with narrow QRS complex and left ventricular hypertrophy with giant negative T waves. His cineangiogram showed severe apical hypertrophy. An electrophysiologic study was performed. The results of programmed atrial pacing show the existence of the dual A-V nodal pathways. The A-H interval at rapid atrial pacing increased maximally by 103 msec. Atrial stimulation could depolarize parts of the atrium without altering the supraventricular tachycardia. These findings suggested that preferential rapidly conducting A-V nodal and intranodal reentry are the responsible mechanisms in this reciprocating tachycardia. We conclude that the short P-R interval was due to intranodal reentry through the dual A-V nodal pathways. To our knowledge, a case of Lown-Ganong-Levine syndrome with apical hypertrophic cardiomyopathy has not been previously described in the literature.

  11. An Anelastic Allspeed Projection Method for GravitationallyStratified Flows

    SciTech Connect

    Gatti-Bono, Caroline; Colella, Phillip

    2005-02-24

    This paper looks at gravitationally-stratified atmospheric flows at low Mach and Froude numbers and proposes a new algorithm to solve the compressible Euler equations, in which the asymptotic limits are recovered numerically and the boundary conditions for block-structured local refinement methods are well-posed. The model is non-hydrostatic and the numerical algorithm uses a splitting to separate the fast acoustic dynamics from the slower anelastic dynamics. The acoustic waves are treated implicitly while the anelastic dynamics is treated semi-implicitly and an embedded-boundary method is used to represent mountain ranges. We present an example that verifies our asymptotic analysis and a set of results that compares very well with the classical gravity wave results presented by Durran.

  12. Momentumless and almost-momentumless wakes in a stratified fluid

    NASA Astrophysics Data System (ADS)

    Spedding, Geoffrey; Meunier, Patrice

    2003-11-01

    Extensive measurements have been made on the wakes of towed spheres and other bodies for steady horizontal motion in a stratified fluid. It has been proposed, and largely verified, that these bluff body wakes can serve as canonical cases for the decay of initially turbulent motions in the presence of a stable background density gradient and applications have ranged from oceanography and climate modelling to prediction of signatures from undersea objects. While experimental data on momentumless wakes has been available for more than 25 years, it has not been in such quantitative detail as the towed body case and so the two have been difficult to compare directly. Here the similarity and scaling behaviour of mean and turbulence quantities are reported for slender and blunt bodies, at, or close to momentum balance. Results are then compared with literature values, and with the standard towed configuration, to identify those features that are general and those that are not.

  13. On upstream blocking in a viscous diffusive stratified flow

    NASA Technical Reports Server (NTRS)

    Koop, C. G.; Redekopp, L. G.

    1975-01-01

    The effect of diffusion of specie upon the flow about a transverse flat plate moving horizontally in a viscous stratified medium is considered. Asymptotic expansions are used to define a parameter regime where a viscous-diffusive-buoyancy balance is dominant. The solution, expressed in terms of an inverse Fourier transform, is numerically integrated. The results show that, as in the non-diffusive problem, a region of closed streamlines exists ahead of the body. However, unlike the case where diffusion is neglected, the density field within this recirculating region is uniquely determined and found to be statically stable. It is also found that varying the relative amount of diffusion affects not only the density distribution, but the velocity profile as well, indicating a strong coupling between the vorticity and specie equation.

  14. Nonlinear evolution of a layered stratified shear flow

    NASA Astrophysics Data System (ADS)

    Lee, V.; Caulfield, C. P.

    2001-10-01

    We investigate numerically and theoretically the nonlinear evolution of a parallel shear flow at moderate Reynolds number which has embedded within it a mixed layer of intermediate fluid. The two relatively thin strongly stratified density interfaces are centered on the edges of the shear layer. We are particularly interested in the development of primary and secondary instabilities. We present the results of a stability analysis which predicts that such flows may be unstable to stationary vortical disturbances which are a generalization of an inviscid instability first considered by G.I. Taylor. We investigate the behavior of these "Taylor billows" at finite amplitude through two-dimensional numerical simulations. We observe that the braid regions connecting adjacent primary Taylor billows are susceptible to secondary, inherently two-dimensional instabilities. We verify that these secondary instabilities, which take the form of small elliptical vortices, arise due to a local intensification of the spanwise vorticity in the braid region.

  15. Thermal surface signatures of ship propeller wakes in stratified waters

    NASA Astrophysics Data System (ADS)

    Voropayev, S. I.; Nath, C.; Fernando, H. J. S.

    2012-11-01

    When a ship moves in temperature stratified water, e.g., in the ocean diurnal thermocline, the propeller(s) as well as the turbulent boundary layer of the hull mix the surface water with underlying colder fluid. As a result, when observed from above, a temperature "wake signature" of ˜1-2 °C may be detected at the water surface. To quantify this phenomenon, theoretical modeling and physical experiments were conducted. The dominant processes responsible for thermal wake generation were identified and parameterized. Most important similarity parameters were derived and estimates for wake signature contrast were made. To verify model predictions, scaled experiments were conducted, with the water surface temperature measured using a sensitive infrared camera. Comparison of laboratory measurements with model estimates has shown satisfactory agreement, both qualitative and quantitatively. Estimates for ocean ship-wake scenarios are also given, which are supported by available field observations.

  16. Remote sensing of optical properties in continuously stratified waters

    NASA Technical Reports Server (NTRS)

    Gordon, H. R.

    1978-01-01

    The radiative transfer equation is solved by Monte Carlo methods for natural waters in which the optical properties are distributed with depth. It is demonstrated that interpreting the reflectance of a continuously stratified ocean in terms of an equivalent homogeneous ocean yields the average of a particular combination of the water's optical properties over the dimensionless penetration depth. Although in general the dimensionless penetration depth cannot be remotely measured, a method is presented for estimating the actual penetration depth from the remote observations if the medium's absorption coefficient is known, independent of depth, and sufficiently large. The application of this to the remote measurement of the vertical distribution of suspended sediments is discussed in detail.

  17. Hydrodynamics of stratified epithelium: Steady state and linearized dynamics

    NASA Astrophysics Data System (ADS)

    Yeh, Wei-Ting; Chen, Hsuan-Yi

    2016-05-01

    A theoretical model for stratified epithelium is presented. The viscoelastic properties of the tissue are assumed to be dependent on the spatial distribution of proliferative and differentiated cells. Based on this assumption, a hydrodynamic description of tissue dynamics at the long-wavelength, long-time limit is developed, and the analysis reveals important insights into the dynamics of an epithelium close to its steady state. When the proliferative cells occupy a thin region close to the basal membrane, the relaxation rate towards the steady state is enhanced by cell division and cell apoptosis. On the other hand, when the region where proliferative cells reside becomes sufficiently thick, a flow induced by cell apoptosis close to the apical surface enhances small perturbations. This destabilizing mechanism is general for continuous self-renewal multilayered tissues; it could be related to the origin of certain tissue morphology, tumor growth, and the development pattern.

  18. Microfluidic titer plate for stratified 3D cell culture.

    PubMed

    Trietsch, Sebastiaan J; Israëls, Guido D; Joore, Jos; Hankemeier, Thomas; Vulto, Paul

    2013-09-21

    Human tissues and organs are inherently heterogeneous. Their functionality is determined by the interplay between different cell types, their secondary architecture, vascular system and gradients of signaling molecules and metabolites. Here we propose a stratified 3D cell culture platform, in which adjacent lanes of gels and liquids are patterned by phaseguides to capture this tissue heterogeneity. We demonstrate 3D cell culture of HepG2 hepatocytes under continuous perfusion, a rifampicin toxicity assay and co-culture with fibroblasts. 4T1 breast cancer cells are used to demonstrate invasion and aggregation models. The platform is incorporated in a microtiter plate format that renders it fully compatible with automation and high-content screening equipment. The extended functionality, ease of handling and full compatibility to standard equipment is an important step towards adoption of Organ-on-a-Chip technology for screening in an industrial setting.

  19. Fluid mixing in stratified gravity currents: the Prandtl mixing length.

    PubMed

    Odier, P; Chen, J; Rivera, M K; Ecke, R E

    2009-04-01

    Shear-induced vertical mixing in a stratified flow is a key ingredient of thermohaline circulation. We experimentally determine the vertical flux of momentum and density of a forced gravity current using high-resolution velocity and density measurements. A constant eddy-viscosity model provides a poor description of the physics of mixing, but a Prandtl mixing length model relating momentum and density fluxes to mean velocity and density gradients works well. For the average gradient Richardson number Ri(g) approximately 0.08 and a Taylor Reynolds number Re(lambda) approximately 100, the mixing lengths are fairly constant, about the same magnitude, comparable to the turbulent shear length. PMID:19392360

  20. Acoustic field and array response uncertainties in stratified ocean media.

    PubMed

    Hayward, Thomas J; Dhakal, Sagar

    2012-07-01

    The change-of-variables theorem of probability theory is applied to compute acoustic field and array beam power probability density functions (pdfs) in uncertain ocean environments represented by stratified, attenuating ocean waveguide models. Computational studies for one and two-layer waveguides investigate the functional properties of the acoustic field and array beam power pdfs. For the studies, the acoustic parameter uncertainties are represented by parametric pdfs. The field and beam response pdfs are computed directly from the parameter pdfs using the normal-mode representation and the change-of-variables theorem. For two-dimensional acoustic parameter uncertainties of sound speed and attenuation, the field and beam power pdfs exhibit irregular functional behavior and singularities associated with stationary points of the mapping, defined by acoustic propagation, from the parameter space to the field or beam power space. Implications for the assessment of orthogonal polynomial expansion and other methods for computing acoustic field pdfs are discussed.

  1. The current structure of stratified tidal planetary boundary layer flow

    SciTech Connect

    Myrhaug, D.; Slaattelid, O.H.

    1995-12-31

    The paper presents the bottom shear stress and velocity profiles in stratified tidal planetary boundary layer flow by using similarity theory. For a given seabed roughness length, free stream current velocity components, frequency of tidal oscillation, Coriolis parameter and stratification parameter the maximum bottom shear stress is determined for flow conditions in the rough, smooth and transitional smooth-to-rough turbulent regime. Further, the direction of the bottom shear stress and the velocity profiles are given. Comparison is made with data from field measurements of time-independent as well as tidal planetary boundary layer flow for neutral conditions, and the agreement between the predictions and the data is generally good. Further, an example of application for stable stratification is given, and qualitatively the predictions show, as expected, that the bottom shear stress and the thickness of the boundary layer become smaller for stable than for neutral stratification. Other features of the tidal planetary boundary layer flow are also discussed.

  2. Internal combustion engine using premixed combustion of stratified charges

    DOEpatents

    Marriott, Craig D.; Reitz, Rolf D. (Madison, WI

    2003-12-30

    During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

  3. Advanced stratified charge rotary aircraft engine design study

    NASA Technical Reports Server (NTRS)

    Badgley, P.; Berkowitz, M.; Jones, C.; Myers, D.; Norwood, E.; Pratt, W. B.; Ellis, D. R.; Huggins, G.; Mueller, A.; Hembrey, J. H.

    1982-01-01

    A technology base of new developments which offered potential benefits to a general aviation engine was compiled and ranked. Using design approaches selected from the ranked list, conceptual design studies were performed of an advanced and a highly advanced engine sized to provide 186/250 shaft Kw/HP under cruise conditions at 7620/25,000 m/ft altitude. These are turbocharged, direct-injected stratified charge engines intended for commercial introduction in the early 1990's. The engine descriptive data includes tables, curves, and drawings depicting configuration, performance, weights and sizes, heat rejection, ignition and fuel injection system descriptions, maintenance requirements, and scaling data for varying power. An engine-airframe integration study of the resulting engines in advanced airframes was performed on a comparative basis with current production type engines. The results show airplane performance, costs, noise & installation factors. The rotary-engined airplanes display substantial improvements over the baseline, including 30 to 35% lower fuel usage.

  4. Status and trends in the fish community of Lake Superior, 2012

    USGS Publications Warehouse

    Gorman, Owen T.; Evrard, Lori M.; Cholwek, Gary A.; Vinson, Mark

    2015-01-01

    Due to ship mechanical failures, nearshore sampling was delayed from mid-May to mid-June to mid-June to late August. The shift to summer sampling when the lake was stratified may have affected our estimates, thus our estimates of status and trends for the nearshore fish community in 2012 are tentative, pending results of future surveys. However, the results of the 2012 survey are comparable with those during 2009 and 2010 when lake-wide fish biomass declined to < 1.40 kg/ha. Declines in prey fish biomass since the late 1990s can be attributed to a combination of increased predation by recovered lake trout populations and infrequent and weak recruitment by the principal prey fishes, cisco and bloater. In turn declines in lake trout biomass since the mid-2000s are likely linked to declines in prey fish biomass. If lean and siscowet lake trout populations in nearshore waters continue to remain at current levels, predation mortality will likely maintain the relatively low prey fish biomass observed in recent years. Alternatively, if lake trout populations show a substantial decline in abundance in upcoming years, prey fish populations may rebound in a fashion reminiscent to what occurred in the late 1970s to mid-1980s. However, this scenario depends on substantial increases in harvest of lake trout, which seems unlikely given that levels of lake trout harvest have been flat or declining in many regions of Lake Superior since 2000.

  5. Scale-Dependent Dispersion in a Stratified Granular Aquifer

    NASA Astrophysics Data System (ADS)

    Pickens, John F.; Grisak, Gerald E.

    1981-08-01

    The magnitude of longitudinal dispersivity in a sandy stratified aquifer was investigated using laboratory column and field tracer tests. The field investigations included two-single-well injection-withdrawal tracer tests using 131I and a two-well recirculating withdrawal-injection tracer test using 51Cr-EDTA. The tracer movement within the aquifer was monitored in great detail with multilevel point-sampling instrumentation. A constant value for dispersivity of 0.7 cm was found to be representative (and independent of travel distance) at the scale of an individual level within the aquifer. A dispersivity of 0.035 cm was determined from laboratory column tracer tests as a representative laboratory-scale value for sand from the field site. The scale effect observed between the laboratory dispersivity and the dispersivity from individual levels in the aquifer is caused by the greater inhomogeneity of the aquifer (e.g., laminations within individual layers) and the averaging caused by the groundwater sampling system. Full-aquifer dispersivities of 3 and 9 cm obtained from the single-well tests indicate a scale effect with the value obtained being dependent mainly on the effect of transverse migration of tracer between the layers and the total injection volume. The full-aquifer dispersivity of 50 cm from the two-well test is scale-dependent, controlled by the distance between the injection and withdrawal wells (8 m) and hydraulic conductivity distribution in the aquifer. Scale-dependent full-aquifer dispersivity expressions were derived relating dispersivity to the statistical properties of a stratified geologic system where the hydraulic conductivity distribution is normal, log normal or arbitrary. In the developed expressions, dispersivity is a linear function of the mean travel distance. Proportionality constants ranged from 0.041 to 0.256 for the hydraulic conductivity distributions obtained from the field tracer tests.

  6. The Negative Effective Magnetic Pressure in Stratified Forced Turbulence

    NASA Astrophysics Data System (ADS)

    Brandenburg, Axel; Kemel, Koen; Kleeorin, Nathan; Rogachevskii, Igor

    2012-04-01

    To understand the basic mechanism of the formation of magnetic flux concentrations, we determine by direct numerical simulations the turbulence contributions to the mean magnetic pressure in a strongly stratified isothermal layer with large plasma beta, where a weak uniform horizontal mean magnetic field is applied. The negative contribution of turbulence to the effective mean magnetic pressure is determined for strongly stratified forced turbulence over a range of values of magnetic Reynolds and Prandtl numbers. Small-scale dynamo action is shown to reduce the negative effect of turbulence on the effective mean magnetic pressure. However, the turbulence coefficients describing the negative effective magnetic pressure phenomenon are found to converge for magnetic Reynolds numbers between 60 and 600, which is the largest value considered here. In all these models, the turbulent intensity is arranged to be nearly independent of height, so the kinetic energy density decreases with height due to the decrease in density. In a second series of numerical experiments, the turbulent intensity increases with height such that the turbulent kinetic energy density is nearly independent of height. Turbulent magnetic diffusivity and turbulent pumping velocity are determined with the test-field method for both cases. The vertical profile of the turbulent magnetic diffusivity is found to agree with what is expected based on simple mixing length expressions. Turbulent pumping is shown to be down the gradient of turbulent magnetic diffusivity, but it is twice as large as expected. Corresponding numerical mean-field models are used to show that a large-scale instability can occur in both cases, provided the degree of scale separation is large enough and hence the turbulent magnetic diffusivity small enough.

  7. Stratified wakes, the high Froude number approximation, and potential flow

    NASA Astrophysics Data System (ADS)

    Vasholz, David P.

    2011-12-01

    Properties of a steady wake generated by a body moving uniformly at constant depth through a stratified fluid are studied as a function of two parameters inserted into the linearized equations of motion. The first parameter, μ, multiplies the along-track gradient term in the source equation. When formal solutions for an arbitrary buoyancy frequency profile are written as eigenfunction expansions, one finds that the limit μ → 0 corresponds to a high Froude number approximation accompanied by a substantial reduction in the complexity of the calculation. For μ = 1, upstream effects are present and the eigenvalues correspond to critical speeds above which transverse waves disappear for any given mode. For sufficiently high modes, the high Froude number approximation is valid. The second tracer multiplies the square of the buoyancy frequency term in the linearized conservation of mass equation and enables direct comparisons with the limit of potential flow. Detailed results are given for the simplest possible profile, in which the buoyancy frequency is independent of depth; emphasis is placed upon quantities that can, in principle, be experimentally measured in a laboratory experiment. The vertical displacement field is written in terms of a stratified wake form factor {{H}} , which is the sum of a wavelike contribution that is non-zero downstream and an evanescent contribution that appears symmetrically upstream and downstream. First- and second-order cross-track moments of {{H}} are analyzed. First-order results predict enhanced upstream vertical displacements. Second-order results expand upon previous predictions of wavelike resonances and also predict evanescent resonance effects.

  8. Visualization periodic flows in a continuously stratified fluid.

    NASA Astrophysics Data System (ADS)

    Bardakov, R.; Vasiliev, A.

    2012-04-01

    To visualize the flow pattern of viscous continuously stratified fluid both experimental and computational methods were developed. Computational procedures were based on exact solutions of set of the fundamental equations. Solutions of the problems of flows producing by periodically oscillating disk (linear and torsion oscillations) were visualized with a high resolutions to distinguish small-scale the singular components on the background of strong internal waves. Numerical algorithm of visualization allows to represent both the scalar and vector fields, such as velocity, density, pressure, vorticity, stream function. The size of the source, buoyancy and oscillation frequency, kinematic viscosity of the medium effects were traced in 2D an 3D posing problems. Precision schlieren instrument was used to visualize the flow pattern produced by linear and torsion oscillations of strip and disk in a continuously stratified fluid. Uniform stratification was created by the continuous displacement method. The buoyancy period ranged from 7.5 to 14 s. In the experiments disks with diameters from 9 to 30 cm and a thickness of 1 mm to 10 mm were used. Different schlieren methods that are conventional vertical slit - Foucault knife, vertical slit - filament (Maksoutov's method) and horizontal slit - horizontal grating (natural "rainbow" schlieren method) help to produce supplementing flow patterns. Both internal wave beams and fine flow components were visualized in vicinity and far from the source. Intensity of high gradient envelopes increased proportionally the amplitude of the source. In domains of envelopes convergence isolated small scale vortices and extended mushroom like jets were formed. Experiments have shown that in the case of torsion oscillations pattern of currents is more complicated than in case of forced linear oscillations. Comparison with known theoretical model shows that nonlinear interactions between the regular and singular flow components must be taken

  9. Creation of residual flows in a partially stratified estuary

    USGS Publications Warehouse

    Stacey, M.T.; Burau, J.R.; Monismith, Stephen G.

    2001-01-01

    The creation of residual flows in estuaries is examined using acoustic Doppler current profiler data sets from northern San Francisco Bay. The data sets are analyzed using principal component analysis to examine the temporal variability of the flows which create the residual circulation. It is seen that in this periodically and partially stratified estuary the residual flows are created through a series of pulses with strong variability at the 24-hour timescale, through the interaction of shear, stratification and mixing. This interaction is captured through the use of a dimensionless number, the horizontal Richardson number (Rix), which is developed to examine the local balance between the stratifying and destratifying forces at the tidal timescale. It is seen that Rix is a valuable parameter in predicting the onset of the residual-creating events, with a threshold value of ??? 3 on ebb tides. This critical value is argued to be a threshold, above which the stratification and shear flow create a feedback effect, each further intensifying the other. This feedback results in a highly variable exchange flow which creates the estuarine residual in intermittent pulses rather than as a steady flow. Although typically attributed to baroclinic forcing, an argument is made that these pulses of residual-creating exchange flow could be created by barotropic forcing in the presence of variable stratification which is asymmetric between flood and ebb tides. This result poses a great challenge for turbulence modeling, as the timing and magnitude of stratification and shear must be correctly simulated on the tidal timescale in order to reproduce the effects seen in the data sets presented. Copyright 2001 by the American Geophysical Union.

  10. Particle dispersion in a stably stratified channel flow

    NASA Astrophysics Data System (ADS)

    Pasquero, C.; Armenio, V.

    2003-04-01

    The motion of particles in a stably stratified channel flow is relevant in geophysic and environmental applications. In the present research this problem has been studied numerically using a mixed Lagrangian-Eulerian technique (Lagrangian motion of an ensemble of particles in an Eulerian field) by means of large eddy simulation. A stratified channel flows can be decomposed into a buoyancy affected region, with a strong turbulent activity, close to the walls, and into a buoyancy dominated region, where turbulence is strongly inhibited, in the center of the channel. For strong stratifications, counter gradient heat fluxes steepen the density gradient moving hot fluid up and cold fluid down. The stratification in the central region of the channel becomes extremely stable. However, the vertical turbulent energy, defined as the difference between the total vertical kinetic energy and its temporal average, is very strong. Particle statistics have shown that this can be related to the presence of high frequency internal waves, that do not contribute to dispersion because of their highly coherent behavior. Vertical stratification is shown to reduce or increase the decorrelation time for vertical motion, depending on the Richardson number. When stratification is increased there are two competing effects: Structures have a smaller vertical scale (acting to reduce the decorrelation time) and vertical velocities are smaller (acting to increase the decorrelation time, since particles stay for a longer time into a given structure in the flow). It has been shown that for low stratification the first mechanism dominates, while for large stratification the second effect is more important. The research is in progress and results for both fluid and inertial particles will be presented at the conference.

  11. Nonlinear gravity-wave interactions in stratified turbulence

    NASA Astrophysics Data System (ADS)

    Remmel, Mark; Sukhatme, Jai; Smith, Leslie M.

    2014-04-01

    To investigate the dynamics of gravity waves in stratified Boussinesq flows, a model is derived that consists of all three-gravity-wave-mode interactions (the GGG model), excluding interactions involving the vortical mode. The GGG model is a natural extension of weak turbulence theory that accounts for exact three-gravity-wave resonances. The model is examined numerically by means of random, large-scale, high-frequency forcing. An immediate observation is a robust growth of the so-called vertically sheared horizontal flow (VSHF). In addition, there is a forward transfer of energy and equilibration of the nonzero-frequency (sometimes called "fast") gravity-wave modes. These results show that gravity-wave-mode interactions by themselves are capable of systematic interscale energy transfer in a stratified fluid. Comparing numerical simulations of the GGG model and the full Boussinesq system, for the range of Froude numbers ( Fr) considered (0.05 ≤ Fr ≤ 1), in both systems the VSHF is hardest to resolve. When adequately resolved, VSHF growth is more vigorous in the GGG model. Furthermore, a VSHF is observed to form in milder stratification scenarios in the GGG model than the full Boussinesq system. Finally, fully three-dimensional nonzero-frequency gravity-wave modes equilibrate in both systems and their scaling with vertical wavenumber follows similar power-laws. The slopes of the power-laws obtained depend on Fr and approach -2 (from above) at Fr = 0.05, which is the strongest stratification that can be properly resolved with our computational resources.

  12. Reactive trace metals in the stratified central North Pacific

    SciTech Connect

    Bruland, K.W. ); Orians, K.J. ); Cowen, J.P. )

    1994-08-01

    Vertical concentration profiles of the dissolved and suspended particulate phases were determined for a suite of reactive trace metals, Al, Fe, Mn, Zn, and Cd, during summertime at a station in the center of the North Pacific gyre. During summer the euphotic zone becomes stratified, forming a shallow (0-25 m), oligotrophic, mixed layer overlying a subsurface (25-140 m), strongly-stratified region. The physical, biological, and chemical structure within the euphotic zone during this period enhanced the effect of atmospheric inputs of Al, Fe, and Mn on mixed layer concentrations. For example, the concentration of dissolved Fe in the surface mixed layer was eighteen times that observed at a depth of 100 m. The observed aeolian signature of these metals matched that predicted from estimates of atmospheric input during the period between the onset of stratification and sampling. The distributions of suspended particulate Al, Fe, and Mn all exhibited minima in the euphotic zone and increased with depth into the main thermocline. Particulate Al and Fe were then uniform with depth below 1000 m before increasing in the near bottom nepheloid layer. Average particulate phase concentrations in intermediate and deep waters of the central North Pacific were 1.0, 0.31, and 0.055 nmol[center dot]kg[sup [minus]1] for Al, Fe, and Mn, respectively. The distribution of particulate Cd exhibited a maximum within the subsurface euphotic zone. Particulate zinc also exhibited a surface maximum, albeit a smaller one. Concentrations of particulate Zn and Cd in intermediate and deep waters were 17 and 0.2 pmol[center dot]kg[sup [minus]1]. Substantial interbasin differences in particulate trace metals occur. Concentrations of suspended particulate Al, Fe, and Mn were three to four times lower in the central North Pacific than recently reported for the central North Atlantic gyre, consistent with differences in atmospheric input to these two regions.

  13. Vertical structure of organic-rich fine sediment relevant to resuspension: Lake Apopka, Florida

    NASA Astrophysics Data System (ADS)

    Mehta, Ashish; Manning, Andrew

    2014-05-01

    Wind-induced resuspension potential of organic-rich bottom sediment in many shallow lakes of Florida is a major management concern. If resuspension remains unabated, high oxygen demand of these waters typically rich in nutrients tends to bring about an abundance of toxic algae and drastic loss of fish population. A case in point is the highly eutrophic Lake Apopka in central Florida which has an area of 12,500 ha and a mean depth of about 2 m. The development of a water management strategy for this and similar lakes requires a thorough understanding of fine sediment dynamics peculiar to bottom muck. Although lake muck is fine-grained, from its surface down to a depth of 1 to 2 m it is significantly stratified with respect to material composition and density. As a result, characteristic parameters defining the state of the bottom, its resuspension by wind and settling of suspended matter tend to differ from those of beds of inorganic matter. In addition, above the bed surface defined by the so-called space-filling density of solids, a fluid-like, almost entirely organic, "fluff" layer can exist without dewatering to form a solid bed. Modeling the response of this lake sediment to wind requires a detailed characterization of the state and transport behavior of stratified muck. This characterization and its significance in sediment transport modeling are described for Lake Apopka.

  14. Long Term Deep Mixing Changes in Lakes to Climate Change. The Question of When and How?

    NASA Astrophysics Data System (ADS)

    Sahoo, G. B.; Schladow, S. G.; Reuter, J.

    2009-12-01

    Lake Tahoe (California-Nevada), an ice free warm-monomictic lake, has been warmed up over the last 35 years due to climate change. Lake Tahoe strongly stratifies during summer and its water body mixes well during winter. The last 35 years records indicate that complete lake turn over takes place once or twice in 3 to 4 years. If the lake warming trend continues, its deep mixing might be stopped at some point in the future. Since deep mixing supplies dissolved oxygen from surface to bottom, reduced mixing may result in evolution of anoxic condition near the sediment-water interface. The Intergovernmental Panel on Climate Change report (IPCC 2007) indicates continued warming over the next few decades. It is therefore important to assess mixing dynamics of the lake using predictions of the global circulation models (GCMs). The dynamic lake model (DLM), developed by University of California Davis researcher was used to estimate the mixing dynamics of the lake. The GCM-predicted trends in meteorological variables for the grid cell that includes Lake Tahoe were obtained from GCMs: (1) Model for Interdisciplinary Research on Climate V. 3.2 High Resolution (MIROC-HIRES) Japan, (2) National Center for Atmospheric Research, Community Climate Model (NCAR CCM V. 3.0), and (3) National Oceanic and Atmospheric Administration (NOAA) - Geophysical Fluid Dynamics Laboratory V CM2.1 (NOAA GFDL CM2.1). Sensitivity analysis results demonstrates that a change in longwave radiations has pronounced effect on lake warming. Results of 40-year simulations show that the lake continues to become warmer at the rate of approximately 0.013 oC per year and more stable. With continued climate change, deep mixing (full or greater than 300m) will cease after one-two decades. This indicates that Lake Tahoe is likely to transition to meromictic lake because of reduced mixing and increasing stability. This may result in major water quality problems and ecological changes over time.

  15. Settling-driven convection: A mechanism of sedimentation from stratified fluids

    NASA Astrophysics Data System (ADS)

    Hoyal, David C. J. D.; Bursik, Marcus I.; Atkinson, Joseph F.

    1999-04-01

    Convection driven by sediment particles may play an important role in sedimentation from the base of buoyant (hypopycnal) plumes, for example, fluvial plumes in stratified estuaries and lakes, black smokers on the ocean floor, volcanic clouds, and coastal currents. In addition to the well-known double-diffusive convection mechanism, another mode of convective instability development is by settling across the density interface. We performed laboratory experiments to investigate this fingering/convective instability mechanism and its effect on particle distribution in the water column and deposition at the bed. A simple theoretical model of finger formation at a fluid density interface is developed based on an analogy with thermal/plume formation at a flat heated plate. This model, which involves a thickening interface layer that becomes gravitationally unstable relative to the ambient fluid, is in good agreement with measurements of finger size and instability wavelength from visualization experiments. Since fingering at the density interface drives larger-scale convection in the fluid below, a mass balance model of the lower layer, assuming strong mixing (i.e., uniform sediment concentration) is successfully applied to predict sediment concentration in the water column and deposition at the bed. Strong mixing can be assumed since convective velocities are usually much greater than the particle fall velocities. As convection proceeds, the sediment concentrations in the two layers approach each other and convection will die out. Using the model equations, we develop analytical expressions for the time when convection ceases and the portion of sediment remaining in the water column.

  16. A Review of the Results and Methodology in the 1999 Noel Levitz Student Satisfaction Survey at Salt Lake Community College.

    ERIC Educational Resources Information Center

    Cooney, Frank

    This report analyzes the 1999 Student Satisfaction Inventory (SSI) survey results of Salt Lake Community College (SLCC) (Utah) conducted by the Noel-Levitz company. In 1999, a stratified random sample was utilized that produced a more representative profile of the student demographics compared to previous years (e.g., the percentage of full-time…

  17. Lake Superior Zooplankton Biomass Predictions from LOPC Tow Surveys Compare Well with a Probability Based Net Survey

    EPA Science Inventory

    We conducted a probability-based sampling of Lake Superior in 2006 and compared the zooplankton biomass estimate with laser optical plankton counter (LOPC) predictions. The net survey consisted of 52 sites stratified across three depth zones (0-30, 30-150, >150 m). The LOPC tow...

  18. Uighur medicine abnormal savda munzip (ASMq) suppresses expression of collagen and TGF-β1 with concomitant induce Smad7 in human hypertrophic scar fibroblasts

    PubMed Central

    Li, Nan; Kong, Menglong; Ma, Tao; Gao, Weicheng; Ma, Shaolin

    2015-01-01

    Background: Hypertrophic scar (HS) is a common dermal disease, for which numerous treatments are currently available but they do not always yield excellent therapeutic results. Hence, alternative strategy are needed. Recent basic and clinic research has shown that Uighur medicine abnormal savda munzip (ASMq) has anti-hypertrophic scar properties but its molecular mechanism is unknown. The aim of this study was to explore the effect of ASMq on TGF-β/Smads signaling in fibroblasts derived from hypertrophic scar. Purpose: To investigate the effect of ASMq on the TGF-β/Smads signaling pathway in hypertrophic scar fibroblasts (HSFs). Methods: Hypertrophic scar fibroblasts (HSFs) were isolated from human of hypertrophic scar and passaged to the 3~4 generation, which were treated with the different concentrations of ASMq. Cells treated with 5-Fu served as the positive control group. After treatment for 48 hours, expressions of Smad7, TGF-β1, type I and III collagen, were examined by immunocytochemistry, reverse transcription PCR and Western blotting, respectively. Results: ASMq markedly enhanced the expression of inhibitory Smad7, with suppression of type I and III collagen and TGF-β1. We observed that treatment of ASMq induced Smad7 to enter the cytoplasm from the nucleus of hypertrophic fibroblasts. Conclusions: ASMq inhibits scarring probably by enhancing the expression of inhibitory Smad7, and inhibiting TGF-β1, collagen expression, and is a potential treatment for scarring. PMID:26309506

  19. [Hypertrophic gastropathy similar to Ménétrier's disease in pigs slaughtered in accordance with regulations].

    PubMed

    Negro, M; Valenza, F; Galloni, M; Guarda, F

    1990-01-01

    The authors found during a study concerning the gastric pathology in pigs 2828 cases of hypertrophic gastropathy in 8408 regularly slaughtered animals. After a description of the morphologic patterns of the lesions, the authors make some pathogenetic hypothesis and conclude that this lesion is like Ménétrier's disease of man.

  20. In-the-bag decentration of an intraocular lens in a patient with a tendency to hypertrophic scarring

    PubMed Central

    Joshi, Rajesh Subhash

    2016-01-01

    Summary We report a case of rapid anterior lens capsular contraction leading to decentration of a hydrophilic acrylic lens with stiff haptics (Rayner design). To our knowledge, this is the first report to investigate early capsular contraction with folding of the haptic over the optic in a patient with a tendency toward hypertrophic scar formation. PMID:27330480

  1. Food of lake trout in Lake Superior

    USGS Publications Warehouse

    Dryer, William R.; Erkkila, Leo F.; Tetzloff, Clifford L.

    1965-01-01

    Stomachs were examined from 1,492 lake trout and 83 siscowets collected from Lake Superior. Data are given on the food of lake trout of legal size (17 inches or longer) by year, season, and depth of water, and on the relation between food and size among smaller lake trout. Fish contributed 96.7 to 99.9 per cent of the total volume of food in the annual samples. Ciscoes (Coregonus spp.) were most common (52.2 to 87.5 per cent of the volume) in 1950 to 1953 and American smelt ranked first (65.6 per cent of the volume) in 1963. Cottids were in 8.9 to 12.3 per cent of the stomachs in 1950 to 1953 but in only 4.3 per cent in 1963. Insects ranked second to fish in occurrence (9.6 per cent for the combined samples) and crustaceans followed at 3.9 per cent. The greatest seasonal changes in the food of lake trout were among fish caught at 35 fathoms and shallower. The occurrence of Coregonus increased from 34.6 per cent in February-March to 71.1 per cent in October-December. Smelt were in 76.9 per cent of the stomachs in February-March but in only 2.2 per cent in October-December. Cottids, Mysis relicta, and insects were most common in the July-September collections. Lake trout taken at depths greater than 35 fathoms had eaten a higher percentage of Cottidae and Coregonus than had those captured in shallower water. Smelt, ninespine sticklebacks, Mysis, and insects were more frequent in stomachs of lake trout from less than 35 fathoms. Crustaceans comprised more than 70 per cent of the total volume of food for 4.0- to 7.9-inch lake trout but their importance decreased as the lake trout grew larger. Pontoporeia affinis was the most common in the stomachs of 4.0- to 6.9-inch lake trout and Mysis held first rank at 7.0 to 12.9 inches. Ostracods were important only to 4.0- to 4.9-inch lake trout. As the lake trout became larger, the importance of fish grew from 4.4-per cent occurrence at 5.0 to 5.9 inches to 93.9 per cent at 16.0 to 16.9 inches. Smelt were most commonly eaten by

  2. Cultural Meromixis: the Influence of Road Salt Deicers on Two Urban Kettle Lakes

    NASA Astrophysics Data System (ADS)

    Koretsky, C.; Sibert, R.; Wyman, D. A.; Griffey, D.; Krishnamurthy, R. V.

    2014-12-01

    The increasing global use of road salt deicers has led to an influx of salts, particularly NaCl and CaCl2, into urban surface waters. This influx has led to documented salinization of drinking water supplies, as well as damage to ecosystems. There is an increasing recognition that the influx of road salt deciers may also influence the physical mixing of lakes, with dramatic consequences for lake biogeochemistry. In this study, the water column chemistry of two kettle lakes in urban Kalamazoo, MI, USA was monitored for over a year. Woods Lake, an ~9.7 ha, 14 m max depth lake, receives most water from storm water sewers, whereas nearby Asylum Lake, an ~19.8 ha, 15.8 m max depth lake, is primarily groundwater fed. The water columns of both lakes are strongly redox stratified, but exhibit some significant differences in water chemistry. The input of road salt has caused Woods Lake to transition to meromixis, with permanently anoxic bottom waters and significant accumulations of dissolved Mn(II), Fe(II), NH3, PO4-3 and sometimes HS- in the hypolimnion. In contrast, Asylum Lake appears to be monomictic, with turnover occurring in fall, but not spring. During most seasons, the hypolimnion of Asylum Lake has significant levels of dissolved Mn(II), NH3, PO4-3, and sometimes HS-, but dissolved Fe(II) remains below detection limits. A comparison of δ18O and δD with the local meteoric water line demonstrates that both lakes undergo significant evaporation. Woods Lake is considerably more influenced by evaporation than Asylum Lake, presumably due to the longer residence time of water in Woods Lake. The longer residence time, together with the smaller volume of water in Woods Lake, likely explains the more rapid transition to meromixis compared to Asylum Lake. This study demonstrates that road salt deicers can significantly influence the biogeochemistry and physical function of urban lakes, and in some cases can result in dimictic lakes transitioning to cultural meromixis.

  3. Phytoplankton variability in Lake Fraijanes, Costa Rica, in response to local weather variation.

    PubMed

    Umaña-Villalobos, Gerardo

    2014-06-01

    Phytoplankton species show a variety in morphology which is the result of adaptations to pelagic life including responses to fluctuations in water column dynamics driven by weather conditions. This has been reported in the oceans and in Northern temperate lakes. In order to observe whether tropical freshwater phytoplankton responds to seasonal variation in weather, the weekly variation in temperature of the water column and phytoplankton composition was studied in Lake Fraijanes, Costa Rica, a shallow (6.2m) lake at 1 640m above sea level. A chain of data loggers for temperature was placed in the deepest point in the lake to register temperature every hour at four different depths, and phytoplankton samples were retrieved every week for a year. Additional monthly samples for nutrients were taken at two depths. Notwithstanding its shallowness, the lake developed a thermal gradient which kept the water column stratified for several months during dry season. Whole lake overturns occurred during cold spells with intense precipitation. Phytoplankton changed throughout the year mainly through a shift in dominant taxa. From September to February the lake was frequently mixed by rain storms and windy weather. At this time, phytoplankton was dominated by Chlorococcal green algae. From March to June, the lake was stratified and warmer. Phytoplankton became dominated by Cyanobateria, mainly colonial Chroococcales. The rainy season started again in May 2009. During June and July the lake started to mix intermittently during rain events and phytoplankton showed a brief increase in the contribution of Chlorococcales. These changes fitted well to a general model of phytoplankton succession based on functional groups identified according to their morphology and adaptations.

  4. Characteristics of lakes in the eastern United States. Volume 3. Data compendium of site characteristics and chemical variables

    SciTech Connect

    Kanciruk, P.; Eilers, J.M.; McCord, R.A.; Landers, D.H.; Brakke, D.F.

    1986-06-01

    A water sample was collected from each of 1612 lakes. This subset of lakes was selected from within three regions of the eastern U.S. (the Northeast, Upper Midwest, and Southeast) expected to exhibit low buffering capacity. Each region was divided in subregions. Subregions were further stratified by alkalinity map class. A suite of chemical variables and physical attributes thought to influence or be influenced by surface-water acidification was measured for each lake. The results of these measurements and data analyses are described in the report.

  5. Water quality of Lake Austin and Town Lake, Austin, Texas

    SciTech Connect

    Andrews, F.L.; Wells, F.C.; Shelby, W.J.; McPherson, E.M.

    1988-01-01

    Lake Austin and Town Lake are impoundments on the Colorado River in Travis County, central Texas, and are a source of water for municipal industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Small vertical temperature variations in both lakes were attributed to shallow depths in the lakes and short retention times of water in the lakes during the summer months. The largest areal variations in dissolved oxygen generally occur in Lake Austin during the summer as a result of releases of water from below the thermocline in Lake Travis. Except for iron, manganese, and mercury, dissolved concentrations of trace elements in water collected from Lake Austin and Town Lake did not exceed the primary or secondary drinking water standards set by the US Environmental Protection Agency. Little or no effect of stormwater runoff on temperature, dissolved oxygen, or minor elements could be detected in either Lake Austin or Town Lake. Little seasonal or areal variation was noted in nitrogen concentrations in Lake Austin or Town lake. Total phosphorus concentrations generally were small in both lakes. Increased concentrations of nitrogen and phosphorus were detected after storm runoff inflow in Town Lake, but not in Lake Austin; densities of fecal-coliform bacteria increased in Lake Austin and Town Lake, but were substantially greater in Town Lake than in Lake Austin. 18 refs., 38 figs., 59 tabs.

  6. Lake trout rehabilitation in Lake Huron

    USGS Publications Warehouse

    Eshenroder, Randy L.; Payne, N. Robert; Johnson, James E.; Bowen, Charles; Ebener, Mark P.

    1995-01-01

    Efforts to restore lake trout (Salvelinus namaycush) in Lake Huron after their collapse in the 1940s were underway in the early 1970s with completion of the first round of lampricide applications in tributary streams and the stocking of several genotypes. We assess results of rehabilitation and establish a historical basis for comparison by quantifying the catch of spawning lake trout from Michigan waters in 1929-1932. Sixty-eight percent of this catch occurred in northern waters (MH-1) and most of the rest (15%) was from remote reefs in the middle of the main basin. Sea lampreys (Petromyzon marinus) increased in the early 1980s in the main basin and depressed spawning populations of lake trout. This increase was especially severe in northern waters and appeared to be associated with untreated populations in the St. Marys River. Excessive commercial fishing stemming from unresolved treaty rights also contributed to loss of spawning fish in northern Michigan waters. Seneca-strain lake trout did not appear to be attacked by sea lampreys until they reached a size > 532 mm. At sizes > 632 mm, Seneca trout were 40-fold more abundant than the Marquette strain in matched-planting experiments. Natural reproduction past the fry stage has occurred in Thunder Bay and South Bay, but prospects for self-sustaining populations of lake trout in the main basin are poor because sea lampreys are too abundant, only one side of the basin is stocked, and stocking is deferred to allow commercial gillnetting in areas where most of the spawning occurred historically. Backcross lake trout, a lake trout x splake (s. Fontinalis x s. Namaycush) hybrid, did not reproduce in Georgian Bay, but this genotype is being replaced with pure-strain lake trout, whose early performance appears promising.

  7. An open-label pilot study to evaluate the efficacy and tolerability of a silicone gel in the treatment of hypertrophic scars using clinical and ultrasound assessments.

    PubMed

    Lacarrubba, Francesco; Patania, Lara; Perrotta, Rosario; Stracuzzi, Giorgio; Nasca, Maria Rita; Micali, Giuseppe

    2008-01-01

    Silicone gel sheets and intralesional corticosteroids are effective treatments for hypertrophic scars according to evidence studies. The aim of this study was to evaluate, both clinically and by ultrasound, the efficacy and tolerability of a topical self-drying silicone gel containing polysiloxane and silicone dioxide applied twice daily in eight hypertrophic scars. After 6 months all lesions showed evident clinical and/or ultrasound improvement, with a mean scar thickness reduction of 37% (range 20-54%). Although controlled trials in larger series of patients are necessary, our results suggest that the self-drying silicone gel may represent a safe and effective treatment for hypertrophic scars.

  8. Methane and carbon dioxide emissions from 40 lakes along a north–south latitudinal transect in Alaska

    DOE PAGES

    Sepulveda-Jauregui, A.; Walter Anthony, K. M.; Martinez-Cruz, K.; Greene, S.; Thalasso, F.

    2014-09-12

    Uncertainties in the magnitude and seasonality of various gas emission modes, particularly among different lake types, limit our ability to estimate methane (CH4) and carbon dioxide (CO2) emissions from northern lakes. Here we assessed the relationship between CH4 and CO2 emission modes in 40 lakes along a latitudinal transect in Alaska to physicochemical limnology and geographic characteristics, including permafrost soil type surrounding lakes. Emission modes included Direct Ebullition, Diffusion, Storage flux, and a newly identified Ice-Bubble Storage (IBS) flux. We found that all lakes were net sources of atmospheric CH4 and CO2, but the climate warming impact of lake CH4more » emissions was two times higher than that of CO2. Ebullition and Diffusion were the dominant modes of CH4 and CO2 emissions respectively. IBS, ~ 10% of total annual CH4 emissions, is the release to the atmosphere of seasonally ice-trapped bubbles when lake ice confining bubbles begins to melt in spring. IBS, which has not been explicitly accounted for in regional studies, increased the estimate of springtime emissions from our study lakes by 320%. Geographically, CH4 emissions from stratified, dystrophic interior Alaska thermokarst (thaw) lakes formed in icy, organic-rich yedoma permafrost soils were 6-fold higher than from non-yedoma lakes throughout the rest of Alaska. Total CH4 emission was correlated with concentrations of phosphate and total nitrogen in lake water, Secchi depth and lake area, with yedoma lakes having higher nutrient concentrations, shallower Secchi depth, and smaller lake areas. Our findings suggest that permafrost type plays important roles in determining CH4 emissions from lakes by both supplying organic matter to methanogenesis directly from thawing permafrost and by enhancing nutrient availability to primary production, which can also fuel decomposition and methanogenesis.« less

  9. A new CO2 laser technique for the treatment of pediatric hypertrophic burn scars

    PubMed Central

    Żądkowski, Tomasz; Nachulewicz, Paweł; Mazgaj, Maciej; Woźniak, Magdalena; Cielecki, Czesław; Wieczorek, Andrzej Paweł; Beń-Skowronek, Iwona

    2016-01-01

    Abstract Treatment of hypertrophic scars arising as a result of thermal burns in children is still a big problem. The results of the treatment are not satisfactory for patients and parents, and new methods of treatment are still investigated. We present the use of one of the most modern carbon dioxide (CO2) lasers (Lumenis Encore laser equipped with a Synergistic Coagulation and Ablation for Advanced Resurfacing module) in the treatment of hypertrophic scars in children after burns. From March to April of 2013, a group of 47 patients aged 6 to 16 years underwent 57 laser surgery treatments. The average time from accident was 7.5 years. The results of treatment were investigated in 114 areas. The assessed areas were divided into 2 groups: 9-cm2 area 1, where the thickness of the scar measured by physician was the lowest and 9-cm2 area 2, where the thickness of the scar was the biggest. The results were considered on the Vancouver Scar Scale (VSS) independently by the surgeon and by parents 1, 4, and 8 months after the procedure. In addition, ultrasound evaluation of the scar thickness before and after laser procedure was made. VSS total score improved in all areas assessed by both the physician and parents. The biggest change in total VSS score in area 1 in the evaluation of the investigator was obtained at follow-up after the 1st month of treatment (average 7.23 points before and 5.18 points after the 1st month after surgery—a difference of 2.05 points). Scar ratings by parents and the physician did not differ statistically (P < 0.05). In the ultrasound assessment, the improvement was statistically significant, more frequently for both minimum and maximum thickness of the scars (B-mode measures) (P < 0.05). The use of a CO2 laser in the treatment of hypertrophic scars in children is an effective and safe method. The use of a CO2 laser improves the appearance and morphology of scarring assessed using the VSS by both the parents and the physician. The

  10. Using time scales to characterize phytoplankton assemblages in a deep subalpine lake during the thermal stratification period: Lake Iseo, Italy

    NASA Astrophysics Data System (ADS)

    Marti, Clelia Luisa; Imberger, Jörg; Garibaldi, Letizia; Leoni, Barbara

    2016-03-01

    A combination of field observations and 3-D hydrodynamic simulations were used to identify the phytoplankton species and to estimate the various time scales of the dominant physical and biological processes in Lake Iseo, a deep subalpine lake located in northern Italy, during a stratified period (July 2010). By ordering the rate processes time scales, we derive a phytoplankton patch categorization and growth interpretation that provides a general framework for the spatial distribution of phytoplankton concentration in Lake Iseo and illuminates the characteristics of their ecological niches. The results show that the diurnal surface layer was well mixed, received strong diurnal radiation, had low phosphorus concentrations and the phytoplankton biomass was sustained by the green alga Sphaerocystis schroeterii. The vertical mixing time scales were much shorter than horizontal mixing time scales causing a depth-uniform chlorophyll a concentration. The horizontal patch scale was determined by horizontal dispersion balancing the phytoplankton growth time scale, dictating the success of the observed green algae. The strongly stratified nutrient-rich metalimnion had mild light conditions and Diatoma elongatum and Planktothrix rubescens made up the largest proportions of the total phytoplankton biomass at the intermediate and deeper metalimnetic layers. The vertical transport time scales were much shorter than horizontal transport and vertical dispersion leading to growth niche for the observed phytoplankton. The study showed that time-scale hierarchy mandates the essential phytoplankton attributes or traits for success in a particular section of the water column and/or water body.

  11. Hypertrophic cardiomyopathy

    MedlinePlus

    ... permanent pacemaker to control the heartbeat An implanted defibrillator that recognizes life-threatening heart rhythms and sends an electrical pulse to stop them. Sometimes a defibrillator is placed, even if the patient has not ...

  12. Stage fluctuations of Wisconsin lakes

    USGS Publications Warehouse

    House, Leo B.

    1985-01-01

    This report describes lake-stage fluctuations of 83 gaged lakes in Wisconsin and presents techniques for estimating stage fluctuation at ungaged lakes. Included are stage information at 83 lakes and stage-frequency data for 32 of these lakes that had sufficient record for analysis. Lakes are classified by a hydrologic-topographic lake classification scheme as ground-water flowthrough (GWF) lakes, surface-water drainage (SWD) lakes, and surface-water flow-through (SWF) lakes. Lakes within the same class were found to have similar water-level fluctuations. The lake-stage records indicate that most annual maximums occur during the months of May and June for all three classes. Annual minimum lake levels generally occur in September for surface-water drainage lakes, in March for surface-water flowthrough lakes, and in November for ground-water flow-through lakes. Data for each lake include location, period of water-level record, hydrologic classification, drainage area, surface area, lake volume, maximum depth, long-term mean stage and its standard deviation, maximum and minimum observed lake stage, and the average annual lake-stage fluctuation.

  13. Fishing and the oceanography of a stratified shelf sea

    NASA Astrophysics Data System (ADS)

    Sharples, Jonathan; Ellis, Jim R.; Nolan, Glenn; Scott, Beth E.

    2013-10-01

    Fishing vessel position data from the Vessel Monitoring System (VMS) were used to investigate fishing activity in the Celtic Sea, a seasonally-stratifying, temperate region on the shelf of northwest Europe. The spatial pattern of fishing showed that three main areas are targeted: (1) the Celtic Deep (an area of deeper water with fine sediments), (2) the shelf edge, and (3) an area covering several large seabed banks in the central Celtic Sea. Data from each of these regions were analysed to examine the contrasting seasonality of fishing activity, and to highlight where the spring-neap tidal cycle appears to be important to fishing. The oceanographic characteristics of the Celtic Sea were considered alongside the distribution and timing of fishing, illustrating likely contrasts in the underlying environmental drivers of the different fished regions. In the central Celtic Sea, fishing mainly occurred during the stratified period between April and August. Based on evidence provided in other papers of this Special Issue, we suggest that the fishing in this area is supported by (1) a broad increase in primary production caused by lee-waves generated by seabed banks around spring tides driving large supplies of nutrients into the photic zone, and (2) greater concentrations of zooplankton within the region influenced by the seabed banks and elevated primary production. In contrast, while the shelf edge is a site of elevated surface chlorophyll, previous work has suggested that the periodic mixing generated by an internal tide at the shelf edge alters the size-structure of the phytoplankton community which fish larvae from the spawning stocks along the shelf edge are able to exploit. The fishery for Nephrops norvegicus in the Celtic Deep was the only one to show a significant spring-neap cycle, possibly linked to Nephrops foraging outside their burrows less during spring tides. More tentatively, the fishery for Nephrops correlated most strongly with a localised shift in

  14. Observations of turbulence in a partially stratified estuary

    USGS Publications Warehouse

    Stagey, M.T.; Monismith, Stephen G.; Burau, J.R.

    1999-01-01

    The authors present a field study of estuarine turbulence in which profiles of Reynolds stresses were directly measured using an ADCP throughout a 25-h tidal day. The dataset that is discussed quantifies turbulent mixing for a water column in northern San Francisco Bay that experiences a sequence of states that includes a weak ebb and flood that are stratified, followed by a strong, and eventually unstratified, ebb and flood. These measurements show that energetic turbulence is confined to a bottom mixed layer by the overlying stratification. Examination of individual Reynolds stress profiles along with profiles of Richardson number and turbulent Froude number shows that the water column can be divided into regions based on the relative importance of buoyancy effects. Using the measured turbulence production rate P, the dissipation rate e. is estimated. The observed turbulence had values of e/vN2 > 20 all of the time and e/vN2 > 200 most of the time, suggesting that the observed motions were buoyancy affected turbulence rather than internal waves. However, at times, turbulent Froude numbers in much of the upper-water column were less than one, indicating important stratification effects. Taken as a whole, the data show that stratification affects the turbulent velocity variance q2 most severely; that is, observed reductions in u'w' are largely associated with small values of q2 rather than with a dramatic reduction in the efficiency with which turbulent motions produce momentum fluxes. Finally, the dataset is compared to predictions made using the popular Mellor-Yamada level 2.5 closure. These comparisons show that the model tends to underestimate the turbulent kinetic energy in regions of strong stratification where the turbulence is strongly inhomogeneous and to overestimate the turbulent kinetic energy in weakly stratified regions. The length scale does not appear to compensate for these errors, and, as a result, similar errors are seen in the eddy viscosity

  15. Suppression of ventricular fibrillation by electrical modification of the Purkinje system in hypertrophic cardiomyopathy.

    PubMed

    Yokoshiki, Hisashi; Mitsuyama, Hirofumi; Watanabe, Masaya; Mizukami, Kazuya; Tsutsui, Hiroyuki

    2014-09-01

    A 56-year-old man in hypertrophic cardiomyopathy had an electrical storm caused by ventricular fibrillation (VF). Mapping during the initiation of the VF triggered by a premature ventricular contraction (PVC1), with right bundle branch block (RBBB)-like morphology and superior axis, demonstrated a prominent Purkinje-muscle junction (PMJ) delay at the distal portion of the left posterior fascicle. Delivery of radiofrequency (RF) energy to this area abolished the VF triggered by the PVC1. However, VF emerged by triggering another PVC (PVC2) with RBBB-like morphology and inferior axis. Similarly, the initiation of VF was associated with the PMJ delay at the peripheral left anterior fascicle, where RF delivery completely suppressed the VF. The PMJ delay and subsequent Purkinje-muscle reentry-like activity could be essential for the initiation of the Purkinje-related VF.

  16. A polarized multispectral imaging system for quantitative assessment of hypertrophic scars

    PubMed Central

    Ghassemi, Pejhman; Travis, Taryn E.; Moffatt, Lauren T.; Shupp, Jeffrey W.; Ramella-Roman, Jessica C.

    2014-01-01

    Hypertrophic scars (HTS) are a pathologic reaction of the skin and soft tissue to burn or other traumatic injury. Scar tissue can cause patients serious functional and cosmetic issues. Scar management strategies, specifically scar assessment techniques, are vital to improve clinical outcome. To date, no entirely objective method for scar assessment has been embraced by the medical community. In this study, we introduce for the first time, a novel polarized multispectral imaging system combining out-of-plane Stokes polarimetry and Spatial Frequency Domain Imaging (SFDI). This imaging system enables us to assess the pathophysiology (hemoglobin, blood oxygenation, water, and melanin) and structural features (cellularity and roughness) of HTS. To apply the proposed technique in an in vivo experiment, dermal wounds were created in a porcine model and allowed to form into scars. The developed scars were then measured at various time points using the imaging system. Results showed a good agreement with clinical Vancouver Scar Scale assessment and histological examinations. PMID:25360354

  17. [Recommendations for the prevention and therapy of hypertrophic scars and keloids].

    PubMed

    Gauglitz, G G; Kunte, C

    2011-05-01

    Hypertrophic scars and keloids form due to aberrations in the physiologic wound healing cascade characterized by greater and more sustained ECM deposition. Both entities are frequently associated with pain, pruritus and contractures, and are thus significantly affecting the patient's quality of life. Genetic susceptibility, specific anatomic locations, prolonged inflammation and delayed epithelialization significantly contribute to excessive scar formation. However, despite intensive scientific work in this field the complex mechanisms underlying the processes of scarring and wound contraction remain poorly understood and most therapeutic approaches are clinically unsatisfactory. Nevertheless, based on a rising number of clinical studies next to well-known therapeutic concepts including cryotherapy and intralesional triamcinolone, recent techniques extend the spectrum for treating excessive scars. Nonetheless, prevention of pathologic scarring is undoubtedly more effective than to later attempts to treat it. PMID:21468729

  18. Cardiac Magnetic Resonance and Computed Tomography in Hypertrophic Cardiomyopathy: an Update

    PubMed Central

    de Oliveira, Diogo Costa Leandro; Assunção, Fernanda Boldrini; dos Santos, Alair Agusto Sarmet Moreira Damas; Nacif, Marcelo Souto

    2016-01-01

    Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiovascular disease and represents the main cause of sudden death in young patients. Cardiac magnetic resonance (CMR) and cardiac computed tomography (CCT) are noninvasive imaging methods with high sensitivity and specificity, useful for the establishment of diagnosis and prognosis of HCM, and for the screening of patients with subclinical phenotypes. The improvement of image analysis by CMR and CCT offers the potential to promote interventions aiming at stopping the natural course of the disease. This study aims to describe the role of RCM and CCT in the diagnosis and prognosis of HCM, and how these methods can be used in the management of these patients. PMID:27305111

  19. [New strategies for assessing the risk of sudden cardiac death in hypertrophic cardiomyopathy].

    PubMed

    Jaworski, Krzysztof; Możeńska, Olga; Kosior, Dariusz A

    2016-07-01

    Hypertrophic cardiomyopathy (HCM) is characterized by a primarily increased ventricular wall thickness, usually caused by the mutations in genes encoding sarcomere proteins. Thanks to the growing awareness in the medical community as well as advances in diagnostic techniques HCM can be diagnosed at earlier stages than ever before. However, in some cases the first symptom of this disease is a sudden cardiac death (SCD) and diagnosis remains unknown until post-mortem examination. Implantation of a cardioverterdefibrillator (ICD) provides the most effective method of SCD prevention. Nevertheless, due to a number of risks associated with surgery as well as the possession of such devices, predictive factors of serious ventricular arrhythmia in individual patients have been sought for many years. The aim of this review is to present the current strategies of risk assessment and prevention of SCD in patients with HCM. PMID:27590646

  20. [New strategies for assessing the risk of sudden cardiac death in hypertrophic cardiomyopathy].

    PubMed

    Jaworski, Krzysztof; Możeńska, Olga; Kosior, Dariusz A

    2016-08-01

    Hypertrophic cardiomyopathy (HCM) is characterized by a primarily increased ventricular wall thickness, usually caused by the mutations in genes encoding sarcomere proteins. Thanks to the growing awareness in the medical community as well as advances in diagnostic techniques HCM can be diagnosed at earlier stages than ever before. However, in some cases the first symptom of this disease is a sudden cardiac death (SCD) and diagnosis remains unknown until post-mortem examination. Implantation of a cardioverterdefibrillator (ICD) provides the most effective method of SCD prevention. Nevertheless, due to a number of risks associated with surgery as well as the possession of such devices, predictive factors of serious ventricular arrhythmia in individual patients have been sought for many years. The aim of this review is to present the current strategies of risk assessment and prevention of SCD in patients with HCM. PMID:27591441