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Sample records for conditions alter retention

  1. Antecedent growth conditions alter retention of environmental Escherichia coli isolates in transiently wetted porous media

    DEFF Research Database (Denmark)

    Yang, H.-H.; Morrow, J. B.; Grasso, D.;

    2008-01-01

    retentive capacity, may present one such approach. Eight environmental E coli isolates were selected to conduct operational retention tests (ORT) with potential biobarrier materials Pyrax or dolomite, or silica glass as control. The conditions in the ORT were chosen to simulate conditioning by manure...

  2. Retention of acoustic conditioning in St Peter's fish Sarotherodon galilaeus.

    Science.gov (United States)

    Zion, B; Barki, A; Grinshpon, J; Rosenfeld, L; Karplus, I

    2011-03-01

    Groups of St Peter's fish Sarotherodon galilaeus were trained during 28 days of classical conditioning to respond to an acoustic signal by approaching a feeder. Their ability to retain the acoustically conditioned behaviour was tested after eight different intervals ranging from 12 to 188 days from termination of training. Retention tests comprised 7 consecutive days of retraining and the fish response was compared with that of naive fish. Fish response drastically diminished with time. After 55 days, there was no apparent expression of memory on the first test day but fish response was restored on subsequent retraining days, indicating the existence of latent memory. Six months from the end of training, there was no indication of behavioural retention and the response completely vanished. The study was conducted in the context of sea ranching, with classical conditioning used to gain control over fish location. In light of the present results, it is suggested that periodic reinforcement of the acoustically conditioned behaviour should be used.

  3. Effect of reference conditions on flow rate, modifier fraction and retention in supercritical fluid chromatography.

    Science.gov (United States)

    De Pauw, Ruben; Shoykhet Choikhet, Konstantin; Desmet, Gert; Broeckhoven, Ken

    2016-08-12

    When using compressible mobile phases such as fluidic CO2, the density, the volumetric flow rates and volumetric fractions are pressure dependent. The pressure and temperature definition of these volumetric parameters (referred to as the reference conditions) may alter between systems, manufacturers and operating conditions. A supercritical fluid chromatography system was modified to operate in two modes with different definition of the eluent delivery parameters, referred to as fixed and variable mode. For the variable mode, the volumetric parameters are defined with reference to the pump operating pressure and actual pump head temperature. These conditions may vary when, e.g. changing the column length, permeability, flow rate, etc. and are thus variable reference conditions. For the fixed mode, the reference conditions were set at 150bar and 30°C, resulting in a mass flow rate and mass fraction of modifier definition which is independent of the operation conditions. For the variable mode, the mass flow rate of carbon dioxide increases with system pump operating pressure, decreasing the fraction of modifier. Comparing the void times and retention factor shows that the deviation between the two modes is almost independent of modifier percentage, but depends on the operating pressure. Recalculating the set volumetric fraction of modifier to the mass fraction results in the same retention behaviour for both modes. This shows that retention in SFC can be best modelled using the mass fraction of modifier. The fixed mode also simplifies method scaling as it only requires matching average column pressure.

  4. Dense understory dwarf bamboo alters the retention of canopy tree seeds

    Science.gov (United States)

    Qian, Feng; Zhang, Tengda; Guo, Qinxue; Tao, Jianping

    2016-05-01

    Tree seed retention is thought to be an important factor in the process of forest community regeneration. Although dense understory dwarf bamboo has been considered to have serious negative effects on the regeneration of forest community species, little attention has been paid to the relationship between dwarf bamboo and seed retention. In a field experiment we manipulated the density of Fargesia decurvata, a common understory dwarf bamboo, to investigate the retention of seeds from five canopy tree species in an evergreen and deciduous broad-leaved mixed forest in Jinfoshan National Nature Reserve, SW China. We found that the median survival time and retention ratio of seeds increased with the increase in bamboo density. Fauna discriminately altered seed retention in bamboo groves of different densities. Arthropods reduced seed survival the most, and seeds removed decreased with increasing bamboo density. Birds removed or ate more seeds in groves of medium bamboo density and consumed fewer seeds in dense or sparse bamboo habitats. Rodents removed a greater number of large and highly profitable seeds in dense bamboo groves but more small and thin-husked seeds in sparse bamboo groves. Seed characteristics, including seed size, seed mass and seed profitability, were important factors affecting seed retention. The results suggested that dense understory dwarf bamboo not only increased seeds concealment and reduced the probability and speed of seed removal but also influenced the trade-off between predation and risk of animal predatory strategies, thereby impacting the quantity and composition of surviving seeds. Our results also indicated that dense understory dwarf bamboo and various seed characteristics can provide good opportunities for seed storage and seed germination and has a potential positive effect on canopy tree regeneration.

  5. Multi-decadal water-table manipulation alters peatland hydraulic structure and moisture retention.

    Science.gov (United States)

    Moore, Paul; Morris, Paul; Waddington, James

    2015-04-01

    Peatlands are a globally important store of freshwater and soil carbon. However, there is a concern that these water and carbon stores may be at risk due to climate change as vapour pressure deficits, evapotranspiration and summer moisture deficits are expected to increase, leading to greater water table (WT) drawdown in northern continental regions where peatlands are prevalent. We argue that in order to evaluate the hydrological response (i.e. changes in WT level, storage, surface moisture availability, and moss evaporation) of peatlands under future climate change scenarios, the hydrophysical properties of peat and disparities between microforms must be well understood. A peatland complex disturbed by berm construction in the 1950's was used to examine the long-term impact of WT manipulation on peatland hydraulic properties and moisture retention at three adjacent sites with increasing average depth to WT (WET, INTermediate reference, and DRY). All three sites exhibited a strong depth dependence for hydraulic conductivity, specific yield, and bulk density. Moreover, the effect of microform on near-surface peat properties tended to be greater than the site effect. Bulk density was found to explain a high amount of variance (r2 > 0.69) in moisture retention across a range of pore water pressures (-15 to -500 cm H2O), where bulk density tended to be higher in hollows. The estimated residual water content for surface Sphagnum samples, while on average lower in hummocks (0.082 m3 m-3) versus hollows (0.087 m3 m-3), increased from WET (0.058 m3 m-3) to INT (0.088 m3 m-3) to DRY (0.108 m3 m-3) which has important implications for moisture stress under conditions of persistent WT drawdown. While we did not observe significant differences between sites, we did observe a greater proportional coverage and greater relative height of hummocks at the drier sites. Given the potential importance of microtopographic succession for altering peatland hydraulic structure, our

  6. Plant growth conditions alter phytolith carbon

    Directory of Open Access Journals (Sweden)

    Kimberley L Gallagher

    2015-09-01

    Full Text Available Many plants, including grasses and some important human food sources, accumulate and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a glass wastebasket. Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction.

  7. Plant growth conditions alter phytolith carbon.

    Science.gov (United States)

    Gallagher, Kimberley L; Alfonso-Garcia, Alba; Sanchez, Jessica; Potma, Eric O; Santos, Guaciara M

    2015-01-01

    Many plants, including grasses and some important human food sources, accumulate, and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM) that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin, and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a "glass wastebasket." Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins, and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction.

  8. Can bread processing conditions alter glycaemic response?

    Science.gov (United States)

    Lau, Evelyn; Soong, Yean Yean; Zhou, Weibiao; Henry, Jeyakumar

    2015-04-15

    Bread is a staple food that is traditionally made from wheat flour. This study aimed to compare the starch digestibility of western baked bread and oriental steamed bread. Four types of bread were prepared: western baked bread (WBB) and oriental steamed bread (OSB), modified baked bread (MBB) made with the OSB recipe and WBB processing, and modified steamed bread (MSB) made with the WBB recipe and OSB processing. MBB showed the highest starch digestibility in vitro, followed by WBB, OSB and MSB. A similar trend was observed for glycaemic response in vivo. MBB, WBB, OSB and MSB had a glycaemic index of 75±4, 71±5, 68±5 and 65±4, respectively. Processing differences had a more pronounced effect on starch digestibility in bread, and steamed bread was healthier in terms of glycaemic response. The manipulation of processing conditions could be an innovative route to alter the glycaemic response of carbohydrate-rich foods. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. EFFECT OF PAPERMAKING CONDITIONS ON THE RETENTION OF REVERSIBLE THERMOCHROMIC MICROCAPSULE IN PULP

    Directory of Open Access Journals (Sweden)

    Xiaozhou Li

    2011-11-01

    Full Text Available Reversible thermochromic paper able to resist counterfeiting was prepared by adding reversible thermochromic microcapsules (RTM to a slurry of cellulosic fibers, a process that is difficult to imitate. However, the loss of RTM is one of the biggest problems that inhibits industrial use of this approach. So, the retention of RTM in pulp was investigated. The RTM was synthesized by in-situ polymerization, and its properties were characterized. It exhibited strong color contrast between cool and heated conditions, and such behavior could be used to achieve distinctive anticounterfeiting characteristics in the paper. The surface of each microcapsule was smooth, and there was no coherence between particles. The diameters of the microcapsules were mainly in the range 3.0 μm to 5.0 μm. Retention of RTM was closely related to beating degree and pulp composition; the higher the beating degree and hardwood pulp content, the higher the retention of RTM. On the other hand, the retention of RTM was influenced by filler and retention aid. Retention aid promoted retention of RTM to some degree; however, filler was not conductive to retention of RTM. Different addition sequences between RTM and filler or retention aid also influenced the retention of RTM.

  10. The Impact of Principal Leadership on Working Conditions and Teacher Retention in North Carolina Middle Schools

    Science.gov (United States)

    Tomon, Catherine

    2009-01-01

    Research indicates that administrative leadership is the most important factor in determining the climate of a school, and there are specific leadership attributes such as improving working conditions that promote retention. This study seeks to identify leadership behaviors that positively affect quality teacher retention among two particular…

  11. Obsidian: alteration study under hydrothermal-like conditions for its assessment as a nuclear waste glass

    Energy Technology Data Exchange (ETDEWEB)

    Rania, Nishi; Shrivastava, J.P. [Department of Geology, University of Delhi, Delhi - 110007 (India); Bajpai, R.K. [BETDD, Nuclear Recycle Group, BARC, Mumbai - 400008 (India)

    2013-07-01

    Alteration experiments of obsidian (from Osham Hill, Gujarat, India) were performed under hydrothermal-like conditions. Neo-formed minerals were compared with naturally altered minerals to assess its performance. Altered specimens show partial to complete leaching of glass, where ionic release is of the order of Na>Si>K>Ca>Al = Mg>Mn>Ti. SEM-BSE images show distinct microstructures and mineral paragenesis of smectite, chlorite, nontronite, and illite inside and outside of the secondary layers - show retention of Si, Al, and Mg ions, fixation in the alteration products after their meager release to the solution. Secondary minerals-palagonite, chlorite, calcite, zeolite and white colored clays - formed after experiments largely correspond to altered obsidian in the natural environment since ∼ 65 Ma. (authors)

  12. Distributed and Conditional Documents: Conceptualizing Bibliographical Alterities

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    Johanna Drucker

    2014-11-01

    Full Text Available To conceptualize a future history of the book we have to recognize that our understanding of the bibliographical object of the past is challenged by the ontologically unbound, distributed, digital, and networked conditions of the present. As we draw on rich intellectual traditions, we must keep in view the need to let go of the object-centered approach that is at the heart of book history. My argument begins, therefore, with a few assertions. First, that we have much to learn from the scholarship on Old and New World contact that touches on bibliography, document studies, and book history for formulating a non-object centered conception of what a book is. Second, that the insights from these studies can be usefully combined with a theory of the “conditional” document to develop the model of the kinds of distributed artifacts we encounter on a daily basis in the networked conditions of current practices. Finally, I would suggest that this model provides a different conception of artifacts (books, documents, works of textual or graphic art, one in which reception is production and therefore all materiality is subject to performative engagement within varied, and specific, conditions of encounter.

  13. Retention and Extinction of Delay Eyeblink Conditioning Are Modulated by Central Cannabinoids

    Science.gov (United States)

    Steinmetz, Adam B.; Freeman, John H.

    2011-01-01

    Rats administered the cannabinoid agonist WIN55,212-2 or the antagonist SR141716A exhibit marked deficits during acquisition of delay eyeblink conditioning, as noted by Steinmetz and Freeman in an earlier study. However, the effects of these drugs on retention and extinction of eyeblink conditioning have not been assessed. The present study…

  14. Classical Conditioning and Retention of the Infant's Eyelid Response: Effects of Age and Interstimulus Interval.

    Science.gov (United States)

    Little, Arlene H.; And Others

    1984-01-01

    Reports that lengthy interstimulus interval facilitates classical conditioning in very young infants. Infants trained in a single session at 20 days of age exhibited reliable retention of the conditioned eyelid reflex 10 days later, but infants 10 days of age did not. (Author)

  15. The Effects of Hypertext Gloss on Comprehension and Vocabulary Retention under Incidental and Intentional Learning Conditions

    Science.gov (United States)

    Zandieh, Zeinab; Jafarigohar, Manoochehr

    2012-01-01

    The present study investigated comprehension, immediate and delayed vocabulary retention under incidental and intentional learning conditions via computer mediated hypertext gloss. One hundred and eighty four (N = 184) intermediate students of English as a foreign language at an English school participated in the study. They were randomly assigned…

  16. Cellular chloride and bicarbonate retention alters intracellular pH regulation in Cftr KO crypt epithelium.

    Science.gov (United States)

    Walker, Nancy M; Liu, Jinghua; Stein, Sydney R; Stefanski, Casey D; Strubberg, Ashlee M; Clarke, Lane L

    2016-01-15

    Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR), an anion channel providing a major pathway for Cl(-) and HCO3 (-) efflux across the apical membrane of the epithelium. In the intestine, CF manifests as obstructive syndromes, dysbiosis, inflammation, and an increased risk for gastrointestinal cancer. Cftr knockout (KO) mice recapitulate CF intestinal disease, including intestinal hyperproliferation. Previous studies using Cftr KO intestinal organoids (enteroids) indicate that crypt epithelium maintains an alkaline intracellular pH (pHi). We hypothesized that Cftr has a cell-autonomous role in downregulating pHi that is incompletely compensated by acid-base regulation in its absence. Here, 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein microfluorimetry of enteroids showed that Cftr KO crypt epithelium sustains an alkaline pHi and resistance to cell acidification relative to wild-type. Quantitative real-time PCR revealed that Cftr KO enteroids exhibit downregulated transcription of base (HCO3 (-))-loading proteins and upregulation of the basolateral membrane HCO3 (-)-unloader anion exchanger 2 (Ae2). Although Cftr KO crypt epithelium had increased Ae2 expression and Ae2-mediated Cl(-)/HCO3 (-) exchange with maximized gradients, it also had increased intracellular Cl(-) concentration relative to wild-type. Pharmacological reduction of intracellular Cl(-) concentration in Cftr KO crypt epithelium normalized pHi, which was largely Ae2-dependent. We conclude that Cftr KO crypt epithelium maintains an alkaline pHi as a consequence of losing both Cl(-) and HCO3 (-) efflux, which impairs pHi regulation by Ae2. Retention of Cl(-) and an alkaline pHi in crypt epithelium may alter several cellular processes in the proliferative compartment of Cftr KO intestine.

  17. Disruption of Responding Maintained by Conditioned Reinforcement: Alterations in Response-Conditioned-Reinforcer Relations

    Science.gov (United States)

    Lieving, Gregory A.; Reilly, Mark P.; Lattal, Kennon A.

    2006-01-01

    An observing procedure was used to investigate the effects of alterations in response-conditioned-reinforcer relations on observing. Pigeons responded to produce schedule-correlated stimuli paired with the availability of food or extinction. The contingency between observing responses and conditioned reinforcement was altered in three experiments.…

  18. Uranium(VI) retention by Ca-bentonite under (hyper)alkaline conditions

    Energy Technology Data Exchange (ETDEWEB)

    Philipp, Thimo; Schmeide, Katja [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

    2017-06-01

    The sorption behavior of U(VI) on Ca-bentonite was studied in saline, (hyper)alkaline solution via batch experiments. At pH 8.5-9.5 sorption is low in the presence of CO{sub 2} due to the formation of weakly sorbing uranyl carbonate species, which have been observed to dominate speciation up to pH 10 by time-resolved laser-induced fluorescence spectroscopy (TRLFS). In the pH region 10-12, U(VI) retention is almost complete. The retention can either be attributed to strongly sorbing uranyl hydroxo complexes or to a partial precipitation of uranium due to an altered solubility of U(VI) induced by ions leached out of the bentonite.

  19. Involvement of hippocampal NMDA receptors in retention of shuttle avoidance conditioning in rats

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    Roesler R.

    1998-01-01

    Full Text Available The purpose of this research was to evaluate the role of hippocampal N-methyl-D-aspartate (NMDA receptors in acquisition and consolidation of memory during shuttle avoidance conditioning in rats. Adult male Wistar rats were surgically implanted with cannulae aimed at the CA1 area of the dorsal hippocampus. After recovery from surgery, animals were trained and tested in a shuttle avoidance apparatus (30 trials, 0.5-mA footshock, 24-h training-test interval. Immediately before or immediately after training, animals received a bilateral intrahippocampal 0.5-µl infusion containing 5.0 µg of the NMDA competitive receptor antagonist aminophosphonopentanoic acid (AP5 or vehicle (phosphate-buffered saline, pH 7.4. Infusion duration was 2 min per side. Pre-training infusion of AP5 impaired retention test performance (mean ± SEM number of conditioned responses (CRs during retention test session was 16.47 ± 1.78 in the vehicle group and 9.93 ± 1.59 in the AP5 group; P<0.05. Post-training infusion of AP5 did not affect retention (mean ± SEM number of conditioned responses during retention test session was 18.46 ± 1.94 in the vehicle group and 20.42 ± 2.38 in the AP5 group; P>0.10. This impairment could not be attributed to an effect on acquisition, motor activity or footshock sensitivity since AP5 affected neither training session performance measured by the number of CRs nor the number of intertrial crossings during the training session. These data suggest that NMDA receptors in the hippocampus are critical for retention of shuttle avoidance conditioning, in agreement with previous evidence showing a role of NMDA receptors in fear memory.

  20. ALTERATION OF U(VI)-PHASES UNDER OXIDIZING CONDITIONS

    Energy Technology Data Exchange (ETDEWEB)

    A.P. Deditius; S. Utsunomiya; R.C. Ewing

    2006-02-21

    Uranium-(VI) phases are the primary alteration products of the UO{sub 2} in spent nuclear fuel and the UO{sub 2+x}, in natural uranium deposits. The U(VI)-phases generally form sheet structures of edge-sharing UO{sub 2}{sup 2+} polyhedra. The complexity of these structures offers numerous possibilities for coupled-substitutions of trace metals and radionuclides. The incorporation of radionuclides into U(VI)-structures provides a potential barrier to their release and transport in a geologic repository that experiences oxidizing conditions. In this study, we have used natural samples of UO{sub 2+x}, to study the U(VI)-phases that form during alteration and to determine the fate of the associated trace elements.

  1. Age differences in fear retention and extinction in male Sprague-Dawley rats: effects of ethanol challenge during conditioning.

    Science.gov (United States)

    Broadwater, Margaret; Spear, Linda P

    2013-09-01

    Pavlovian fear conditioning is an ideal model to investigate how learning and memory are influenced by alcohol use during adolescence because the neural mechanisms involved have been studied extensively. In Exp 1, adolescent and adult male Sprague-Dawley rats were non-injected or injected with saline, 1 or 1.5 g/kg ethanol intraperitoneally 10 min prior to tone or context conditioning. Twenty-four hours later, animals were tested for tone or context retention and extinction, with examination of extinction retention conducted 24h thereafter. In Exp 2, a context extinction session was inserted between the tone conditioning and the tone fear retention/extinction days to reduce pre-CS baseline freezing levels at test. Basal levels of acquisition, fear retention, extinction, and extinction retention after tone conditioning were similar between adolescent and adult rats. In contrast adolescents showed faster context extinction than adults, while again not differing from adults during context acquisition, retention or extinction retention. In terms of ethanol effects, adolescents were less sensitive to ethanol-induced context retention deficits than adults. No age differences emerged in terms of tone fear retention, with ethanol disrupting tone fear retention at both ages in Exp 1, but at neither age in Exp 2, a difference seemingly due to group differences in pre-CS freezing during tone testing in Exp 1, but not Exp 2. These results suggest that age differences in the acute effects of ethanol on cognitive function are task-specific, and provide further evidence for age differences cognitive functioning in a task thought to be hippocampally related.

  2. Alteration of coffinite under reducing and oxidizing conditions

    Science.gov (United States)

    Deditius, Artur P.; Utsunomiya, Satoshi; Pointeau, Veronique; Ewing, Rodney C.

    2010-05-01

    Coffinite, USiO4, is a one of the two naturally occurring actinide silicates (second is thorite, ThSiO4) studied to elucidate the alteration of spent nuclear fuel (SNF) under reducing conditions in a Si-rich environment. In order to understand the stability of coffinite under different redox condition in natural systems, we have investigated coffinite the Grants Uranium Belt, New Mexico, USA (reducing and oxidizing conditions) utilizing a variety of electron microbeam techniques. Fine-grained coffinite (≤10 μm) from Woodrow Mine coexists with carbonate-fluorapatite (CFAp) and (Ca,Sr)-(meta)autunite (M-Aut). It precipitated under reducing conditions replacing CFAp, pyrite and aluminosilicates. Electron-microprobe analyses (EMPA) of coffinite indicate limited incorporation of P2O5 and CaO, below 2.7 and 3.0 wt.%, respectively, into the coffinite structure during replacement of CFAp. The chemical formula of coffinite is (U0.95±0.09Ca0.15±0.02)Σ1.10±0.1(Si0.84±0.08P0.06±0.02)Σ0.90±0.08. Analysis by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) revealed that coffinite initially formed as crystals as large as 100 nm at the edges of altered CFAp. Subsequently, infiltration of (Na,Ba,Sr)-rich oxidizing fluids into fractures resulted in precipitation of Sr-rich M-Aut (up to 4 wt.% of SrO) at the expense of coffinite and CFAp. High-resolution TEM reveals that Na-rich fluids caused a distortion of the ideal coffinite structure and stabilized amorphous domains that formed due to alpha-decay event radiation damage. Subsequently, the Na-enriched amorphous areas of coffinite were preferentially altered, and secondary porosity formed at the scale of ~1 μm. Porosity also was formed during alteration of CFAp to M-Aut, which facilitated the migration of oxidizing fluids over distances of ~150 μm into CFAp, as evidenced by precipitation of M-Aut. These results show that micro-scale dissolution of apatite can create conditions

  3. CAROTENOID RETENTION IN MINIMALLY PROCESSED BIOFORTIFIED GREEN CORN STORED UNDER RETAIL MARKETING CONDITIONS

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    Natália Alves Barbosa

    2015-08-01

    Full Text Available Storing processed food products can cause alterations in their chemical compositions. Thus, the objective of this study was to evaluate carotenoid retention in the kernels of minimally processed normal and vitamin A precursor (proVA-biofortified green corn ears that were packaged in polystyrene trays covered with commercial film or in multilayered polynylon packaging material and were stored. Throughout the storage period, the carotenoids were extracted from the corn kernels using organic solvents and were quantified using HPLC. A completely factorial design including three factors (cultivar, packaging and storage period was applied for analysis. The green kernels of maize cultivars BRS1030 and BRS4104 exhibited similar carotenoid profiles, with zeaxanthin being the main carotenoid. Higher concentrations of the carotenoids lutein, β-cryptoxanthin, and β-carotene, the total carotenoids and the total vitamin A precursor carotenoids were detected in the green kernels of the biofortified BRS4104 maize. The packaging method did not affect carotenoid retention in the kernels of minimally processed green corn ears during the storage period.

  4. Retention of short chain fatty acids under drying and storage conditions

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    Alexandre Santos Souza

    2011-09-01

    Full Text Available Cheese whey permeate was used as a substrate for the fermentation of Propionibacterium freudenreichi PS1 for the production of short chain fatty acids, components of the bio-aroma of Swiss cheese. The liquid bio-aroma was encapsulated by spray drying under different conditions of air inlet temperature and feed rate. A study was carried out on the stability of the bio-aroma during storage in laminated packages at 30 °C for 96 days using the product showing the greatest retention of acetic and propionic acids. The results showed that the best drying conditions were an air entrance temperature of 180 °C and a feed rate of 24 g/min resulting in particles with a smooth surface and few invaginations and micro-fissures. However, 72% of the acetic acid and 80% of the propionic acid were lost during storage showing that the wall material used was inadequate to guarantee product stability.

  5. [Facilitation of the retention and acceleration of operant conditioning extinction after cingulate cortex lesions in BALB/c mice].

    Science.gov (United States)

    Destrade, C; Gauthier, M

    1981-12-21

    One week after receiving bilateral electrolytic lesions of the cingulate cortex, BALB/c Mice underwent acquisition, retention and extinction of an appetitive operant-conditioning task in a Skinner box. There was no significant difference between lesioned and control animals in acquisition; however, lesioned mice exhibited improved retention and faster extinction. These results suggest a possible involvement of the cingulate cortex in memory processes.

  6. Liquorice-induced sodium retention. Merely an acquired condition of apparent mineralocorticoid excess? A case report.

    Science.gov (United States)

    Negro, A; Rossi, E; Regolisti, G; Perazzoli, F

    2000-01-01

    Excessive ingestion of liquorice may result in sodium retention, hypertension, hypokalemia, and suppression of renin and aldosterone. Similarities between liquorice-induced effects and congenital apparent mineralocorticoid excess have recently been emphasized, as in both conditions, reduced activity of the enzyme 11 beta-hydroxysteroid dehydrogenase type 2 allows cortisol to act as a potent mineralocorticoid. We report a case of generalized edema without any increase in blood pressure, with biochemical and hormonal features of apparent mineralocorticoid excess, in a young woman who had been ingesting substantial amounts of liquorice for several years. Liquorice-induced wide-spread edema without hypertension in our patient, as well as in a few other cases previously reported, and the more common occurrence of edema associated with hypertension challenge the current explanation of liquorice syndrome as a purely acquired apparent mineralocorticoid excess. Indeed, in both congenital apparent and true mineralocorticoid excess, edema is typically absent, as a result of the sodium escape phenomenon. As pressure-natriuresis may be an essential mechanism accounting for the sodium escape phenomenon, some component of liquorice could partially or completely oppose the circulatory response that converts liquorice-induced sodium retention into blood pressure elevation. In patients with unexplained generalized edema and hypokalemia without hypertension, liquorice ingestion should be carefully investigated and the renin-aldosterone system should be assayed.

  7. Low Nitrogen Retention in Soil and Litter under Conditions without Plants in a Subtropical Pine Plantation

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    Yanmei Xiong

    2015-07-01

    Full Text Available Soil acts as a major sink for added nitrogen (N in forests, but it remains unclear about the capacity of soil to immobilize N under conditions without plant roots and whether added N interacts with ecosystem N to affect N retention. We added 15NH415NO3 to in situ soil columns (with leaching and leaf litter (without leaching of two tree species in a subtropical Pinus elliottii plantation. Soil and litter were collected three or eight months after N addition to measure concentrations of indigenous and exogenous N. About 70% of exogenous N was retained in soil three months after N addition, of which 65.9% were in inorganic forms. Eight months after N addition, 16.0% of exogenous N was retained in soil and 9.8%–13.6% was immobilized in litter. N addition increased the mineral release and nitrification of soil indigenous N. Loss of litter indigenous N was also increased by N addition. Our results suggest that N deposition on lands with low root activities or low soil carbon (C contents may lead to increased N output due to low N immobilization. Moreover, the effects of added N on ecosystem indigenous N may decrease the capacity of soil and litter in N retention.

  8. Bacteria transport and retention in intact calcareous soil columns under saturated flow conditions

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    Farrokhian Firouzi Ahmad

    2015-06-01

    Full Text Available Study of bacterial transport and retention in soil is important for various environmental applications such as groundwater contamination and bioremediation of soil and water. The main objective of this research was to quantitatively assess bacterial transport and deposition under saturated conditions in calcareous soil. A series of leaching experiments was conducted on two undisturbed soil columns. Breakthrough curves of Pseudomonas fluorescens and Cl were measured. After the leaching experiment, spatial distribution of bacteria retention in the soil columns was determined. The HYDRUS-1D one- and two-site kinetic models were used to predict the transport and deposition of bacteria in soil. The results indicated that the two-site model fits the observed data better than one-site kinetic model. Bacteria interaction with the soil of kinetic site 1 revealed relatively fast attachment and slow detachment, whereas attachment to and detachment of bacteria from kinetic site 2 was fast. Fast attachment and slow detachment of site 1 can be attributed to soil calcium carbonate that has favorable attachment sites for bacteria. The detachment rate was less than 0.02 of the attachment rate, indicating irreversible attachment of bacteria. High reduction rate of bacteria was also attributed to soil calcium carbonate.

  9. Angiopoietin 2 alters pancreatic vascularization in diabetic conditions.

    Directory of Open Access Journals (Sweden)

    Sophie Calderari

    Full Text Available AIMS/HYPOTHESIS: Islet vascularization, by controlling beta-cell mass expansion in response to increased insulin demand, is implicated in the progression to glucose intolerance and type 2 diabetes. We investigated how hyperglycaemia impairs expansion and differentiation of the growing pancreas. We have grafted xenogenic (avian embryonic pancreas in severe combined immuno-deficient (SCID mouse and analyzed endocrine and endothelial development in hyperglycaemic compared to normoglycaemic conditions. METHODS: 14 dpi chicken pancreases were grafted under the kidney capsule of normoglycaemic or hyperglycaemic, streptozotocin-induced, SCID mice and analyzed two weeks later. Vascularization was analyzed both quantitatively and qualitatively using either in situ hybridization with both mouse- and chick-specific RNA probes for VEGFR2 or immunohistochemistry with an antibody to nestin, a marker of endothelial cells that is specific for murine cells. To inhibit angiopoietin 2 (Ang2, SCID mice were treated with 4 mg/kg IP L1-10 twice/week. RESULTS: In normoglycaemic condition, chicken-derived endocrine and exocrine cells developed well and intragraft vessels were lined with mouse endothelial cells. When pancreases were grafted in hyperglycaemic mice, growth and differentiation of the graft were altered and we observed endothelial discontinuities, large blood-filled spaces. Vessel density was decreased. These major vascular anomalies were associated with strong over-expression of chick-Ang2. To explore the possibility that Ang2 over-expression could be a key step in vascular disorganization induced by hyperglycaemia, we treated mice with L1-10, an Ang-2 specific inhibitor. Inhibition of Ang2 improved vascularization and beta-cell density. CONCLUSIONS: This work highlighted an important role of Ang2 in pancreatic vascular defects induced by hyperglycaemia.

  10. Carbon black retention in saturated natural soils: Effects of flow conditions, soil surface roughness and soil organic matter.

    Science.gov (United States)

    Lohwacharin, J; Takizawa, S; Punyapalakul, P

    2015-10-01

    We evaluated factors affecting the transport, retention, and re-entrainment of carbon black nanoparticles (nCBs) in two saturated natural soils under different flow conditions and input concentrations using the two-site transport model and Kelvin probe force microscopy (KPFM). Soil organic matter (SOM) was found to create unfavorable conditions for the retention. Despite an increased flow velocity, the relative stability of the estimated maximum retention capacity in soils may suggest that flow-induced shear stress forces were insufficient to detach nCB. The KPFM observation revealed that nCBs were retained at the grain boundary and on surface roughness, which brought about substantial discrepancy between theoretically-derived attachment efficiency factors and the ones obtained by the experiments using the two-site transport model. Thus, decreasing ionic strength and increasing solution pH caused re-entrainment of only a small fraction of retained nCB in the soil columns.

  11. Aerobic Mercury-resistant bacteria alter Mercury speciation and retention in the Tagus Estuary (Portugal).

    Science.gov (United States)

    Figueiredo, Neusa L; Canário, João; O'Driscoll, Nelson J; Duarte, Aida; Carvalho, Cristina

    2016-02-01

    Aerobic mercury-resistant bacteria were isolated from the sediments of two highly mercury-polluted areas of the Tagus Estuary (Barreiro and Cala do Norte) and one natural reserve area (Alcochete) in order to test their capacity to transform mercury. Bacterial species were identified using 16S rRNA amplification and sequencing techniques and the results indicate the prevalence of Bacillus sp. Resistance patterns to mercurial compounds were established by the determination of minimal inhibitory concentrations. Representative Hg-resistant bacteria were further tested for transformation pathways (reduction, volatilization and methylation) in cultures containing mercury chloride. Bacterial Hg-methylation was carried out by Vibrio fluvialis, Bacillus megaterium and Serratia marcescens that transformed 2-8% of total mercury into methylmercury in 48h. In addition, most of the HgR bacterial isolates showed Hg(2+)-reduction andHg(0)-volatilization resulting 6-50% mercury loss from the culture media. In summary, the results obtained under controlled laboratory conditions indicate that aerobic Hg-resistant bacteria from the Tagus Estuary significantly affect both the methylation and reduction of mercury and may have a dual face by providing a pathway for pollution dispersion while forming methylmercury, which is highly toxic for living organisms. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Partial Müllerian Duct Retention in Smad4 Conditional Mutant Male Mice.

    Science.gov (United States)

    Petit, Fabrice G; Deng, Chuxia; Jamin, Soazik P

    2016-01-01

    Müllerian duct regression is a complex process which involves the AMH signalling pathway. We have previously demonstrated that besides AMH and its specific type II receptor (AMHRII), BMPR-IA and Smad5 are two essential factors implicated in this mechanism. Mothers against decapentaplegic homolog 4 (Smad4) is a transcription factor and the common Smad (co-Smad) involved in transforming growth factor beta (TGF-β) signalling pathway superfamily. Since Smad4 null mutants die early during gastrulation, we have inactivated Smad4 in the Müllerian duct mesenchyme. Specific inactivation of Smad4 in the urogenital ridge leads to the partial persistence of the Müllerian duct in adult male mice. Careful examination of the urogenital tract reveals that the Müllerian duct retention is randomly distributed either on one side or both sides. Histological analysis shows a uterus-like structure, which is confirmed by the expression of estrogen receptor α. As previously described in a β-catenin conditional mutant mouse model, β-catenin contributes to Müllerian duct regression. In our mutant male embryos, it appears that β-catenin expression is locally reduced along the urogenital ridge as compared to control mice. Moreover, the expression pattern is similar to those observed in control female mice. This study shows that reduced Smad4 expression disrupts the Wnt/β-catenin signalling leading to the partial persistence of Müllerian duct.

  13. The impact of humanitarian context conditions and individual characteristics on aid worker retention

    NARCIS (Netherlands)

    Korff, Valeska P.; Balbo, Nicoletta; Mills, Melinda; Heyse, Liesbet; Wittek, Rafael

    2015-01-01

    High employee turnover rates constitute a major challenge to effective aid provision. This study examines how features of humanitarian work and aid workers' individual characteristics affect retention within one humanitarian organisation, Medecins Sans Frontieres (MSF) Holland. The study extends exi

  14. Changing CS Features Alters Evaluative Responses in Evaluative Conditioning

    Science.gov (United States)

    Unkelbach, Christian; Stahl, Christoph; Forderer, Sabine

    2012-01-01

    Evaluative conditioning (EC) refers to changes in people's evaluative responses toward initially neutral stimuli (CSs) by mere spatial and temporal contiguity with other positive or negative stimuli (USs). We investigate whether changing CS features from conditioning to evaluation also changes people's evaluative response toward these CSs. We used…

  15. The Effect of Labor Market Conditions and Financial Aid on Doctoral Student Retention

    Science.gov (United States)

    Ampaw, Frimpomaa D.

    2010-01-01

    Forty-three percent of doctoral students never complete their degree. This dropout is the highest among graduate and professional degree programs. Previous cross sectional studies of doctoral students' retention show the importance of financial aid in predicting degree completion. The studies however, do not estimate the labor market's effect on…

  16. Cell proliferation alterations in Chlorella cells under stress conditions

    Energy Technology Data Exchange (ETDEWEB)

    Rioboo, Carmen [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain); O' Connor, Jose Enrique [Laboratorio de Citomica, Unidad Mixta de Investigacion CIPF-UVEG, Centro de Investigacion Principe Felipe, Avda. Autopista del Saler, 16, 46013 Valencia (Spain); Prado, Raquel; Herrero, Concepcion [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain); Cid, Angeles, E-mail: cid@udc.es [Laboratorio de Microbiologia, Facultad de Ciencias, Universidad de A Coruna, Campus da Zapateira s/n, 15008 A Coruna (Spain)

    2009-09-14

    Very little is known about growth and proliferation in relation to the cell cycle regulation of algae. The lack of knowledge is even greater when referring to the potential toxic effects of pollutants on microalgal cell division. To assess the effect of terbutryn, a triazine herbicide, on the proliferation of the freshwater microalga Chlorella vulgaris three flow cytometric approaches were used: (1) in vivo cell division using 5-,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) staining was measured, (2) the growth kinetics were determined by cytometric cell counting and (3) cell viability was evaluated with the membrane-impermeable double-stranded nucleic acid stain propidium iodide (PI). The results obtained in the growth kinetics study using CFSE to identify the microalgal cell progeny were consistent with those determined by cytometric cell counting. In all C. vulgaris cultures, each mother cell had undergone only one round of division through the 96 h of assay and the cell division occurred during the dark period. Cell division of the cultures exposed to the herbicide was asynchronous. Terbutryn altered the normal number of daughter cells (4 autospores) obtained from each mother cell. The number was only two in the cultures treated with 250 nM. The duration of the lag phase after the exposure to terbutryn could be dependent on the existence of a critical cell size to activate cytoplasmic division. Cell size, complexity and fluorescence of chlorophyll a of the microalgal cells presented a marked light/dark (day/night) cycle, except in the non-dividing 500 nM cultures, where terbutryn arrested cell division at the beginning of the cycle. Viability results showed that terbutryn has an algastatic effect in C. vulgaris cells at this concentration. The rapid and precise determination of cell proliferation by CFSE staining has allowed us to develop a model for assessing both the cell cycle of C. vulgaris and the in vivo effects of pollutants on growth and

  17. Serum levels of acylcarnitines are altered in prediabetic conditions.

    Directory of Open Access Journals (Sweden)

    Manuel Mai

    Full Text Available OBJECTIVE: The role of mitochondrial function in the complex pathogenesis of type 2 diabetes is not yet completely understood. Therefore, the aim of this study was to investigate serum concentrations of short-, medium- and long-chain acylcarnitines as markers of mitochondrial function in volunteers with normal, impaired or diabetic glucose control. METHODS: Based on a 75 g oral glucose tolerance test, 1019 studied subjects were divided into a group with normal glucose tolerance (NGT; n = 636, isolated impaired fasting glycaemia (IFG; n = 184, impaired glucose tolerance (IGT; n = 87 or type 2 diabetes (T2D; n = 112. Serum concentrations of free carnitine and 24 acylcarnitines were measured by mass spectrometry. RESULTS: Serum levels of acetylcarnitine (C2, propionylcarnitine (C3, octanoylcarnitine (C8, malonylcarnitine/hydroxybutyrylcarnitine (C3DC+C4OH, hexanoylcarnitine (C6, octenoylcarnitine (C8:1, decanoylcarnitine (C10, decenoylcarnitine (C10:1, dodecanoylcarnitine (C12, tetradecenoylcarnitine (C14:1, tetradecadienylcarnitine (C14:2, hydroxytetradecanoylcarnitine (C14OH, hydroxyhexadecanoylcarnitine (C16OH and octadecenoylcarnitine (C18:1 were significantly different among the groups (all p<0.05 adjusted for age, gender and BMI. Between the prediabetic states C14:1, C14:2 and C18:1 showed significantly higher serum concentrations in persons with IGT (p<0.05. Compared to T2D the IFG and the IGT subjects showed lower serum concentrations of malonylcarnitine/hydroxybutyrylcarnitine (C3DC+C4OH (p<0.05. CONCLUSION: Alterations in serum concentrations of several acylcarnitines, in particular tetradecenoylcarnitine (C14:1, tetradecadienylcarnitine (C14:2, octadecenoylcarnitine (C18:1 and malonylcarnitine/hydroxybutyrylcarnitine (C3DC+C4OH are associated not only with T2D but also with prediabetic states.

  18. Modeling fecal bacteria transport and retention in agricultural and urban soils under saturated and unsaturated flow conditions.

    Science.gov (United States)

    Balkhair, Khaled S

    2017-03-01

    Pathogenic bacteria, that enter surface water bodies and groundwater systems through unmanaged wastewater land application, pose a great risk to human health. In this study, six soil column experiments were conducted to simulate the vulnerability of agricultural and urban field soils for fecal bacteria transport and retention under saturated and unsaturated flow conditions. HYDRUS-1D kinetic attachment and kinetic attachment-detachment models were used to simulate the breakthrough curves of the experimental data by fitting model parameters. Results indicated significant differences in the retention and drainage of bacteria between saturated and unsaturated flow condition in the two studied soils. Flow under unsaturated condition retained more bacteria than the saturated flow case. The high bacteria retention in the urban soil compared to agricultural soil is ascribed not only to the dynamic attachment and sorption mechanisms but also to the greater surface area of fine particles and low flow rate. All models simulated experimental data satisfactorily under saturated flow conditions; however, under variably saturated flow, the peak concentrations were overestimated by the attachment-detachment model and underestimated by the attachment model with blocking. The good match between observed data and simulated concentrations by the attachment model which was supported by the Akaike information criterion (AIC) for model selection indicates that the first-order attachment coefficient was sufficient to represent the quantitative and temporal distribution of bacteria in the soil column. On the other hand, the total mass balance of the drained and retained bacteria in all transport experiments was in the range of values commonly found in the literature. Regardless of flow conditions and soil texture, most of the bacteria were retained in the top 12 cm of the soil column. The approaches and the models used in this study have proven to be a good tool for simulating fecal

  19. Alteration, adsorption and nucleation processes on clay-water interfaces: Mechanisms for the retention of uranium by altered clay surfaces on the nanometer scale

    Science.gov (United States)

    Schindler, Michael; Legrand, Christine A.; Hochella, Michael F.

    2015-03-01

    structure is characterized by a low degree of long-range order. Adsorption of U and nucleation of metazeunerite and cuprosklodowskite are strongly controlled by the presence of the adsorbed oxy-anion species arsenate and silica on the Fe-enriched silicates. Heterogeneous nucleation of nano-crystals of the uranyl minerals occurs most likely on adsorption sites of binary uranyl-, arsenate- and silica-complexes as well as on ternary uranyl-arsenate or uranyl-silicate complexes. The uranyl minerals occur as aggregates of misoriented nano-size crystals and are the result of supersaturated solutions and a high number of nucleation sites that prevented the formation of larger crystals through Oswald ripening. The results of this study provide an understanding of interfacial nano-scale processes between uranyl species and altered clay buffers in a potential Nuclear Waste repository as similar alteration conditions of clays may occur in a multi-barrier system.

  20. A Computer-Based Undergraduate Exercise Using Internet-Accessible Simulation Software for the Study of Retention Behavior and Optimization of Separation Conditions in Ion Chromatography

    Science.gov (United States)

    Haddad, Paul R.; Shaw, Matthew J.; Madden, John E.; Dicinoski, Greg W.

    2004-01-01

    The ability to scan retention data over a wide range of eluent composition opens up the possibility of a computerized selection of the optimal separation conditions. The major characteristics of retention behavior, peak-shape effects and pH effects evident in ion chromatography (IC) using common stationary phases and eluents are illustrated.

  1. Pavlovian conditioning of morphine-induced alterations of immune status: evidence for opioid receptor involvement.

    Science.gov (United States)

    Coussons-Read, M E; Dykstra, L A; Lysle, D T

    1994-12-01

    Prior work in our laboratory has shown that morphine's immunomodulatory effects can become conditioned to environmental stimuli that predict drug administration. These immune alterations include conditioned changes in natural killer cell activity, interleukin-2 production, and mitogen-induced lymphocyte proliferation. The present study examined the involvement of opioid receptor activity in the establishment and expression of conditioned morphine-induced alterations of immune status. During the training phase of the experiment, Lewis rats received two conditioning sessions during which a subcutaneous injection of 15 mg/kg morphine sulfate was paired with exposure to a distinctive environment. On the test day, animals were re-exposed to the distinctive environment alone prior to sacrifice. Saline or naltrexone (0.3, 1.0, 3.0 or 10.0 mg/kg) was administered during either the training or the test session. Administration of naltrexone prior to training antagonized the development of all of the conditioned alterations of immune status including changes in the mitogenic responsiveness of splenocytes, suppression of natural killer cell activity, and interleukin-2 production by splenocytes. Naltrexone administration prior to testing also was effective in antagonizing the expression of a subset of morphine-induced conditioned alterations in immune status. Taken together, these studies indicate that opioid receptor activity is involved in the establishment of conditioned morphine-induced immune alterations, as well as in the expression of a subset of these conditioned alterations of immune status.

  2. Role and properties of the gel formed during nuclear glass alteration: importance of gel formation conditions

    Science.gov (United States)

    Gin, S.; Ribet, I.; Couillard, M.

    2001-09-01

    A French SON 68 nuclear glass sample was experimentally altered to assess the mechanisms limiting the glass alteration kinetics, especially during the transition phase between the initial rate r0 and the final rate under silicon saturation conditions. A glass specimen was altered at the initial rate for one week to form a silicon-depleted non-protective gel; the specimen was then leached under static conditions at a glass-surface-to-solution-volume ( S/ V) ratio of 500 m-1 and the alteration kinetics were compared with those of a pristine glass specimen altered under the same conditions. Unexpectedly, after static leaching the previously leached glass was 2.7 times as altered as the pristine specimen, and the steady-state silicon concentration was twice as high for the previously leached specimen. STEM characterization of the alteration films showed that the initial non-protective gel constituted a silicon pump with respect to the glass, and that the glass alteration kinetics were limited only when a fraction of the gel became saturated with silicon, and exhibited protective properties. This work also shows that silicon recondensation was uniform at micrometer scale: the silicon hydrolyzed at the reaction interface then diffused before recondensing over a length comparable to the gel thickness. In addition to these findings, this investigation suggests a reinterpretation of the effect of the S/ V ratio on the glass alteration kinetics and on the steady-state dissolved silicon concentration.

  3. Formation Sequences of Iron Minerals in the Acidic Alteration Products and Variation of Hydrothermal Fluid Conditions

    Science.gov (United States)

    Isobe, H.; Yoshizawa, M.

    2008-12-01

    Iron minerals have important role in environmental issues not only on the Earth but also other terrestrial planets. Iron mineral species related to alteration products of primary minerals with surface or subsurface fluids are characterized by temperature, acidity and redox conditions of the fluids. We can see various iron- bearing alteration products in alteration products around fumaroles in geothermal/volcanic areas. In this study, zonal structures of iron minerals in alteration products of the geothermal area are observed to elucidate temporal and spatial variation of hydrothermal fluids. Alteration of the pyroxene-amphibole andesite of Garan-dake volcano, Oita, Japan occurs by the acidic hydrothermal fluid to form cristobalite leaching out elements other than Si. Hand specimens with unaltered or weakly altered core and cristobalite crust show various sequences of layers. XRD analysis revealed that the alteration degree is represented by abundance of cristobalite. Intermediately altered layers are characterized by occurrence including alunite, pyrite, kaolinite, goethite and hematite. A specimen with reddish brown core surrounded by cristobalite-rich white crust has brown colored layers at the boundary of core and the crust. Reddish core is characterized by occurrence of crystalline hematite by XRD. Another hand specimen has light gray core, which represents reduced conditions, and white cristobalite crust with light brown and reddish brown layers of ferric iron minerals between the core and the crust. On the other hand, hornblende crystals, typical ferrous iron-bearing mineral of the host rock, are well preserved in some samples with strongly decolorized cristobalite-rich groundmass. Hydrothermal alteration experiments of iron-rich basaltic material shows iron mineral species depend on acidity and temperature of the fluid. Oxidation states of the iron-bearing mineral species are strongly influenced by the acidity and redox conditions. Variations of alteration

  4. Prediction of the retention of s-triazines in reversed-phase high-performance liquid chromatography under linear gradient-elution conditions.

    Science.gov (United States)

    D'Archivio, Angelo Antonio; Maggi, Maria Anna; Ruggieri, Fabrizio

    2014-08-01

    In this paper, a multilayer artificial neural network is used to model simultaneously the effect of solute structure and eluent concentration profile on the retention of s-triazines in reversed-phase high-performance liquid chromatography under linear gradient elution. The retention data of 24 triazines, including common herbicides and their metabolites, are collected under 13 different elution modes, covering the following experimental domain: starting acetonitrile volume fraction ranging between 40 and 60% and gradient slope ranging between 0 and 1% acetonitrile/min. The gradient parameters together with five selected molecular descriptors, identified by quantitative structure-retention relationship modelling applied to individual separation conditions, are the network inputs. Predictive performance of this model is evaluated on six external triazines and four unseen separation conditions. For comparison, retention of triazines is modelled by both quantitative structure-retention relationships and response surface methodology, which describe separately the effect of molecular structure and gradient parameters on the retention. Although applied to a wider variable domain, the network provides a performance comparable to that of the above "local" models and retention times of triazines are modelled with accuracy generally better than 7%.

  5. Intra-accumbal blockade of endocannabinoid CB1 receptors impairs learning but not retention of conditioned relief.

    Science.gov (United States)

    Bergado Acosta, Jorge R; Schneider, Miriam; Fendt, Markus

    2017-10-01

    Humans and animals are able to associate an environmental cue with the feeling of relief from an aversive event, a phenomenon called relief learning. Relief from an aversive event is rewarding and a relief-associated cue later induces an attenuation of the startle magnitude or approach behavior. Previous studies demonstrated that the nucleus accumbens is essential for relief learning. Here, we asked whether accumbal cannabinoid type 1 (CB1) receptors are involved in relief learning. In rats, we injected the CB1 receptor antagonist/inverse agonist SR141716A (rimonabant) directly into the nucleus accumbens at different time points during a relief learning experiment. SR141716A injections immediately before the conditioning inhibited relief learning. However, SR141716A injected immediately before the retention test was not effective when conditioning was without treatment. These findings indicate that accumbal CB1 receptors play an important role in the plasticity processes underlying relief learning. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. A strange condition of things : alterity and knowingness in Dickens' 'David Copperfield'.

    OpenAIRE

    Smith, R D

    2013-01-01

    It is sometimes said that we are strangers to ourselves, bearers of internal alterity, as well as to each other. The profounder this strangeness then the greater the difficulty of giving any systematic account of it without paradox: of supposing that our obscurity to ourselves can readily be illuminated. To attempt such an account, in defiance of the paradox, is to risk knowingness: a condition which, appearing to challenge our alterity but in fact often confirming it, holds an ambiguous plac...

  7. Grade retention risk among children with asthma and other chronic health conditions in a large urban school district.

    Science.gov (United States)

    Moonie, Sheniz; Cross, Chad L; Guillermo, Chrisalbeth J; Gupta, Tina

    2010-09-01

    Asthma accounts for 12.8 million missed school days for children nationwide. Whether this excess absenteeism contributes to poor outcomes such as grade retention is of interest. The Clark County School District in Las Vegas, NV has incorporated the Federal "No Child Left Behind Act," which states that absences per individual in excess of 10 per school year are considered unapproved and may put a child at risk for repeating a grade. The purpose of this study was to determine if children with asthma are at increased risk for absenteeism associated with grade retention. Secondary data were obtained for students in attendance for the 2006-2007 school year. Days absent were weighted for enrollment time. Frequencies were obtained using descriptive statistics, and multivariate logistic regression was used to model the odds of absenteeism > 10 days per year. Of 300 881 students, 27 299 (9.1%) reported having asthma, as determined by school health records. The population was 52% male, 37% white, and 39% Hispanic. Significant predictors of missing > 10 days per school year included ethnicity, gender, grade, and health status (P 10 school days per year compared with healthy students or those with a medical condition other than asthma (P school setting for school-aged children.

  8. Role of conceptual knowledge in learning and retention of conditioned fear.

    Science.gov (United States)

    Dunsmoor, Joseph E; Martin, Alex; LaBar, Kevin S

    2012-02-01

    Associating sensory cues with aversive outcomes is a relatively basic process shared across species. Yet higher-order cognitive processes likely contribute to associative fear learning in many circumstances, especially in humans. Here we ask whether fears can be acquired based on conceptual knowledge of object categories, and whether such concept-based fear conditioning leads to enhanced memory representations for conditioned objects. Participants were presented with a heterogeneous collection of images of animals and tools. Objects from one category were reinforced by an electrical shock, whereas the other category was never reinforced. Results confirmed concept-based fear learning through subjective report of shock expectancy, heightened skin conductance responses, and enhanced 24h recognition memory for items from the conditioned category. These results provide novel evidence that conditioned fear can generalize through knowledge of object concepts, and sheds light on the persistent nature of fear memories and category-based fear responses symptomatic of some anxiety disorders.

  9. EFFECTS OF RESPONSE SPACING ON ACQUISITION AND RETENTION OF CONDITIONAL DISCRIMINATIONS

    OpenAIRE

    Porritt, Matthew; Wagner, Karen; Poling, Alan

    2009-01-01

    Pigeons were exposed to a repeated acquisition procedure in which no delays were imposed and rate of responding was relatively high. They also were exposed to conditions in which delays were arranged between trials within chains or between completed chains, and rates of responding were lower. Number of trials, rate of reinforcement, difficulty of the discrimination, and motivating operations were held constant. Terminal accuracy was highest under the no-delay condition, in which rate of respo...

  10. Resistant starch alters gut microbiota and reduces uremic retention solutes in rats with adenine-induced chronic kidney disease

    Science.gov (United States)

    Chronic kidney disease (CKD) is characterized by the reduced ability to void urine, leading to accumulation of waste products in the body. Recently, it has been observed that patients with CKD have an altered gut microbiome. This may in part be due to reduced fiber intake. Patients with CKD are ofte...

  11. SO{sub 2} retention on CaO/activated carbon sorbents. Part III. Study of the retention and regeneration conditions

    Energy Technology Data Exchange (ETDEWEB)

    M.C. Macias-Perez; A. Bueno-Lopez; M.A. Lillo-Rodenas; C. Salinas-Martinez de Lecea; A. Linares-Solano [University of Alicante, Alicante (Spain). Department of Inorganic Chemistry

    2008-11-15

    The retention of SO{sub 2} on CaO/activated carbon sorbents is studied. The effect of several variables such as the reaction temperature, partial pressure of SO{sub 2} for different calcium loads, and O{sub 2} presence are analysed. Additionally, the regeneration and reutilization of spent sorbents is investigated. In all cases presence of well-dispersed CaO in the sorbents improves SO{sub 2} retention in comparison with the activated carbon. In absence of O{sub 2} in the gas mixture, the amount of SO{sub 2} retained does not depend on the SO{sub 2} partial pressure in the range of partial pressures studied and, as expected, SO{sub 2} physisorption on the activated carbon support occurs at room temperature. SO{sub 2} retention occurs in surface CaO between 100{sup o}C and 250{sup o}C, and in bulk CaO above 300{sup o}C. The total calcium conversion is reached at 500{sup o}C. Above 550{sup o}C calcium-catalysed carbon gasification by SO{sub 2} occurs. In presence of O{sub 2} in the gas mixture, the studied sorbents are very effective for SO{sub 2} removal. However, the SO{sub 2} retention process in presence of oxygen must be carried out at temperatures lower than 300{sup o}C to avoid carbon gasification by O{sub 2}. The thermal regeneration of the spent sorbents can be done under inert atmosphere (880{sup o}C) with only 20% activity loss after the first regeneration cycle due to sintering and formation of CaS. No additional activity loss is detected in the subsequent cycles. 22 refs., 10 figs.

  12. Super-Latent Inhibition of Conditioned Taste Preference with a Long Retention Interval

    Science.gov (United States)

    De la Casa, L. G.; Marquez, R.; Lubow, R. E.

    2009-01-01

    A long delay inserted between conditioning and test phases of a 3-stage Latent Inhibition (LI) procedure produces differential effects on LI depending on the delay context. Thus, enhanced LI has been obtained when the delay is spent in a context that is different from the remaining experimental contexts, but not when it is the same. The present…

  13. Alteration of conditioned emotional response and conditioned taste aversion after neonatal ventral hippocampus lesions in rats.

    Science.gov (United States)

    Angst, Marie-Josée; Macedo, Carlos Eduardo; Guiberteau, Thierry; Sandner, Guy

    2007-04-27

    Sprague-Dawley rats were submitted to bilateral ventral hippocampus lesions 7 days after birth according to the Lipska and Weinberger's procedure for modeling schizophrenia. The aim of the present work was to better characterize their learning capacity. A double latent inhibition study was conducted using respectively conditioned taste aversion and conditioned emotional response. In the background of this evaluation, locomotion under apomorphine and startle reactions, inhibited or not by prepulses, was also evaluated. Our experimental methods were the same as those used in previous studies from the laboratory which were found to be sensitive to pharmacological manipulations and shown by others to be unaffected by lesions of the ventral hippocampus carried out in adult rats. In contrast, neonatally lesioned rats, once adults (over 60 days old), were hyper-responsive to noise--i.e., the startle response to a 105 db(A) noise pulse was enhanced--and hyperactive under apomorphine (0.7 mg/kg). The prepulse inhibition properties of the startle remained unchanged. Lesioned rats showed a deficit but not a suppression of conditioning, similar in both tests, but latent inhibition was preserved. Such observations complement the already known memory deficit produced in this neurodevelopmental model of schizophrenia.

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

    Science.gov (United States)

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

    2014-08-01

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

  15. Response of the photosynthetic system to altered protein composition and changes in environmental conditions

    NARCIS (Netherlands)

    Tóth, T.

    2014-01-01

    The photosynthetic thylakoid membrane has a hierarchically ordered structure containing pigment-protein complexes that capture solar radiation and convert it into chemical energy. Its highly dynamic structure is capable to continuously respond to the altered environmental conditions, e.g., light

  16. Response of the photosynthetic system to altered protein composition and changes in environmental conditions

    NARCIS (Netherlands)

    Tóth, T.

    2014-01-01

    The photosynthetic thylakoid membrane has a hierarchically ordered structure containing pigment-protein complexes that capture solar radiation and convert it into chemical energy. Its highly dynamic structure is capable to continuously respond to the altered environmental conditions, e.g., light qua

  17. Phosphorus retention and fractionation in an eutrophic wetland: A one-year mesocosms experiment under fluctuating flooding conditions.

    Science.gov (United States)

    Tercero, María Del Carmen; Álvarez-Rogel, José; Conesa, Héctor Miguel; Párraga-Aguado, Isabel; González-Alcaraz, María Nazaret

    2017-04-01

    This study aimed to evaluate the response of salt marshes to pulses of PO4(3-)-enriched water, with and without the presence of Phragmites australis. A one-year mesocosms experiment was performed in simulated soil profiles (fine-textured surface layers and sandy subsurface layers) from a coastal salt marsh of the Mar Menor lagoon under alternating flooding-drying conditions with eutrophic water, under low (1.95 mg L(-1) P-PO4(3-)) and high (19.5 mg L(-1) P-PO4(3-)) P load, and with the presence/absence of Phragmites. The PO4(3-) concentrations in soil porewater and drainage water were regularly measured, and P accumulated in soils (including a fractionation procedure) and plants (roots, rhizomes, stems and leaves) were analyzed. The experimental mesocosms were highly effective in the removal of P from the eutrophic flooding water (>90% reduction of the P added to the system both in the soil pore water and drainage water), regardless of the nutrient load, the season of the year and the presence/absence of Phragmites. The soil was the main sink of the P added to the system, while Phragmites had a minor role in P removal. The biomass of Phragmites accumulated ∼27% of the P added with the flooding water in the treatment with water of low P load while ∼12% of P in that of high P load; the rhizomes were the organs that contributed the most (∼67-72% of the total P retained by the plants). Ca/Mg compounds were the main contributors to the retention of P in the soil compartment, especially in the fine-textured surface soil layers (∼34-53% of the total P in the soil was present in this fraction). Phragmites favored the retention of P onto metal oxides (∼12% increase of the P retained in the metal oxides fraction in the treatment with water of high P load). Hence, the use of constructed wetlands to ameliorate the negative impacts of P-enriched waters in the Mar Menor lagoon and similar areas is recommended. We propose the incorporation of fine

  18. Ischemic conditioning protects from axoglial alterations of the optic pathway induced by experimental diabetes in rats.

    Directory of Open Access Journals (Sweden)

    Diego C Fernandez

    Full Text Available Diabetic retinopathy is a leading cause of blindness. Visual function disorders have been demonstrated in diabetics even before the onset of retinopathy. At early stages of experimental diabetes, axoglial alterations occur at the distal portion of the optic nerve. Although ischemic conditioning can protect neurons and synaptic terminals against ischemic damage, there is no information on its ability to protect axons. We analyzed the effect of ischemic conditioning on the early axoglial alterations in the distal portion of the optic nerve induced by experimental diabetes. Diabetes was induced in Wistar rats by an intraperitoneal injection of streptozotocin. Retinal ischemia was induced by increasing intraocular pressure to 120 mm Hg for 5 min; this maneuver started 3 days after streptozotocin injection and was weekly repeated in one eye, while the contralateral eye was submitted to a sham procedure. The application of ischemia pulses prevented a deficit in the anterograde transport from the retina to the superior colliculus, as well as an increase in astrocyte reactivity, ultraestructural myelin alterations, and altered morphology of oligodendrocyte lineage in the optic nerve distal portion at early stages of experimental diabetes. Ischemia tolerance prevented a significant decrease of retinal glutamine synthetase activity induced by diabetes. These results suggest that early vision loss in diabetes could be abated by ischemic conditioning which preserved axonal function and structure.

  19. Resting-state connectivity of the amygdala is altered following Pavlovian fear conditioning.

    Science.gov (United States)

    Schultz, Douglas H; Balderston, Nicholas L; Helmstetter, Fred J

    2012-01-01

    Neural plasticity in the amygdala is necessary for the acquisition and storage of memory in Pavlovian fear conditioning, but most neuroimaging studies have focused only on stimulus-evoked responses during the conditioning session. This study examined changes in the resting-state functional connectivity (RSFC) of the amygdala before and after Pavlovian fear conditioning, an emotional learning task. Behavioral results from the conditioning session revealed that participants learned normally and fMRI data recorded during learning identified a number of stimulus-evoked changes that were consistent with previous work. A direct comparison between the pre- and post-conditioning amygdala connectivity revealed a region of dorsal prefrontal cortex (PFC) in the superior frontal gyrus that showed a significant increase in connectivity following the conditioning session. A behavioral measure of explicit memory performance was positively correlated with the change in amygdala connectivity within a neighboring region in the superior frontal gyrus. Additionally, an implicit autonomic measure of conditioning was positively correlated with the change in connectivity between the amygdala and the anterior cingulate cortex (ACC). The resting-state data show that amygdala connectivity is altered following Pavlovian fear conditioning and that these changes are also related to behavioral outcomes. These alterations may reflect the operation of a consolidation process that strengthens neural connections to support memory after the learning event.

  20. Resting-state connectivity of the amygdala is altered following Pavlovian fear conditioning

    Directory of Open Access Journals (Sweden)

    Douglas H Schultz

    2012-08-01

    Full Text Available Neural plasticity in the amygdala is necessary for the acquisition and storage of memory in Pavlovian fear conditioning, but most neuroimaging studies have focused only on stimulus-evoked responses during the conditioning session. This study examined changes in the resting-state functional connectivity (RSFC of the amygdala before and after Pavlovian fear conditioning, an emotional learning task. Behavioral results from the conditioning session revealed that participants learned normally and FMRI data recorded during learning identified a number of stimulus-evoked changes that were consistent with previous work. A direct comparison between the pre and post-conditioning amygdala connectivity revealed a region of dorsal prefrontal cortex (PFC in the superior frontal gyrus that showed a significant increase in connectivity following the conditioning session. A behavioral measure of explicit memory performance was positively correlated with the change in amygdala connectivity within a neighboring region in the superior frontal gyrus. Additionally, an implicit autonomic measure of conditioning was positively correlated with the change in connectivity between the amygdala and the anterior cingulate cortex. The resting-state data show that amygdala connectivity is altered following Pavlovian fear conditioning and that these changes are also related to behavioral outcomes. These alterations may reflect the operation of a consolidation process that strengthens neural connections to support memory after the learning event.

  1. Influence of sludge retention time and temperature on the sludge removal in a submerged membrane bioreactor: comparative study between pure oxygen and air to supply aerobic conditions.

    Science.gov (United States)

    Rodríguez, F A; Leyva-Díaz, J C; Reboleiro-Rivas, P; González-López, J; Hontoria, E; Poyatos, J M

    2014-01-01

    Performance of a bench-scale wastewater treatment plant, which consisted of a membrane bioreactor, was monitored daily using pure oxygen and air to supply aerobic conditions with the aim of studying the increases of the aeration and sludge removal efficiencies and the effect of the temperature. The results showed the capacity of membrane bioreactor systems for removing organic matter. The alpha-factors of the aeration were determined for six different MLSS concentrations in order to understand the system working when pure oxygen and air were used to supply aerobic conditions in the system. Aeration efficiency was increased between 30.7 and 45.9% when pure oxygen was used in the operation conditions (a hydraulic retention time of 12 h and MLSS concentrations between 4,018 and 11,192 mg/L). Sludge removal efficiency increased incrementally, from 0.2 to 1.5% when pure oxygen was used at low sludge retention time and from 1.5% to 15.4% at medium sludge retention time when temperature conditions were lower than 20°C. Moreover, the difference between calculated and experimental sludge retention time was lesser when pure oxygen was used to provide aerobic conditions, so the influence of the temperature decreased when the pure oxygen was used. These results showed the convenience of using pure oxygen due to the improvement in the performance of the system.

  2. Experience of inundation or drought alters the responses of plants to subsequent water conditions

    DEFF Research Database (Denmark)

    Wang, Shu; Callaway, Ragan M.; Zhou, Dao-Wei

    2017-01-01

    early drought. * Results indicate that early exposure to inundation or drought conditions alters how plants respond to later conditions and suggest that exposure to extreme events can induce physiological or morphological changes that improve tolerance for either extreme conditions later. This increased......The availability of water is often highly variable over the life of a plant in nature, and most plants experience episodic extremes in water scarcity and abundance. The importance of plant plasticity in coping with such experiences is widely recognized, but little is known about how plastic...... responses to current conditions are affected by prior environmental experiences. * Our objectives were to investigate the effects of early inundation or drought on the subsequent responses of plant species to the same, opposite or more favourable conditions. * To address these questions, we subjected four...

  3. Alterations in the growth and adhesion pattern of Vero cells induced by nutritional stress conditions.

    Science.gov (United States)

    Genari, S C; Gomes, L; Wada, M L

    1998-01-01

    The pattern of growth, adhesion and protein synthesis in Vero cells submitted to nutritional stress conditions was investigated. The control cells presented a characteristic pattern, with monolayer growth, while the stressed cells presented multilayered growth, with aggregate or spheroid formation which detached on the flask surface and continued their growth in another region. In the soft agar assay, with reduced amount of nutrients, only the stressed cells presented growth, indicating physical and nutritional independence. A 44-kDa protein was observed in stressed cells and was absent in non-stressed cells. The adhesion index and fibronectin synthesis and distribution were altered in stressed cells. After confluence, control cells presented fibronectin accumulation in lateral cell-cell contact regions, while this fibronectin accumulation pattern was not observed in stressed cells. These alterations may be responsible for the multilayered growth and decreased adhesion index observed in stressed cells which were transformed by nutritional stress conditions.

  4. Neuroplastic reactivity of fish induced by altered gravity conditions: a review of recent results

    Science.gov (United States)

    Rahmann, H.; Anken, R. H.

    A review is being presented concerning behavioural, biochemical, histochemical and electronmicroscopical data on the influence of altered gravitational forces on the swimming performance and on the neuronal differentiation of the brain of cichlid fish larvae and adult swordtail fish that had been exposed to hyper-gravity (3g in laboratory centrifuges), hypo-gravity (>10^-2g in a fast-rotating clinostat) and to near weightlessness (10^-4g aboard the spacelab D-2 mission). After long-term alterations of gravity (and parallel light deprivation), initial disturbances in the swimming behaviour followed by a stepwise regain of normal swimming modes are induced. Parallely, neuroplastic reactivities on different levels of investigation were found, such as adaptive alterations of activities of various enzymes in whole brain as well as in specific neuronal integration centers and an intraneuronal reactivity on ultrastructural level in individual brain parts and in the sensory epithelia of the inner ear. Taken together, these data reveal distinct adaptive neuroplastic reactions of fish to altered gravity conditions.

  5. Altered Cerebellar Activity in Visceral Pain-Related Fear Conditioning in Irritable Bowel Syndrome.

    Science.gov (United States)

    Claassen, J; Labrenz, F; Ernst, T M; Icenhour, A; Langhorst, J; Forsting, M; Timmann, D; Elsenbruch, S

    2017-04-01

    There is evidence to support a role of the cerebellum in emotional learning processes, which are demonstrably altered in patients with chronic pain. We tested if cerebellar activation is altered during visceral pain-related fear conditioning and extinction in irritable bowel syndrome (IBS). Cerebellar blood oxygenation level-dependent (BOLD) data from N = 17 IBS patients and N = 21 healthy controls, collected as part of a previous fMRI study, was reanalyzed utilizing an advanced normalizing method of the cerebellum. The differential fear conditioning paradigm consisted of acquisition, extinction, and reinstatement phases. During acquisition, two visual conditioned stimuli (CS) were presented either paired (CS+) or unpaired (CS-) with painful rectal distension as unconditioned stimulus (US). In the extinction phase, the CS+ and CS- were presented without US. For reinstatement, unpaired US presentations were followed by unpaired CS+ and CS- presentations. Group differences in cerebellar activation were analyzed for the contrasts CS+ > CS- and CS- > CS+. During acquisition, IBS patients revealed significantly enhanced cerebellar BOLD responses to pain-predictive (CS+) and safety (CS-) cues compared to controls (p  CS- and CS- > CS+. Group differences were most prominent in the contrast CS- > CS+. During extinction and reinstatement, no significant group differences were found. During visceral pain-related fear conditioning, IBS patients showed increased activations in circumscribed areas of the medial, intermediate, and lateral cerebellum. These areas are involved in autonomic, somatosensory, and cognitive functions and likely contribute to the different aspects of pain-related fear. The cerebellum contributes to altered pain-related fear learning in IBS.

  6. SILICON CARBIDE GRAIN BOUNDARY DISTRIBUTIONS, IRRADIATION CONDITIONS, AND SILVER RETENTION IN IRRADIATED AGR-1 TRISO FUEL PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Lillo, T. M.; Rooyen, I. J.; Aguiar, J. A.

    2016-11-01

    Precession electron diffraction in the transmission electron microscope was used to map grain orientation and ultimately determine grain boundary misorientation angle distributions, relative fractions of grain boundary types (random high angle, low angle or coincident site lattice (CSL)-related boundaries) and the distributions of CSL-related grain boundaries in the SiC layer of irradiated TRISO-coated fuel particles. Two particles from the AGR-1 experiment exhibiting high Ag-110m retention (>80%) were compared to a particle exhibiting low Ag-110m retention (<19%). Irradiated particles with high Ag-110m retention exhibited a lower fraction of random, high angle grain boundaries compared to the low Ag-110m retention particle. An inverse relationship between the random, high angle grain boundary fraction and Ag-110m retention is found and is consistent with grain boundary percolation theory. Also, comparison of the grain boundary distributions with previously reported unirradiated grain boundary distributions, based on SEM-based EBSD for similarly fabricated particles, showed only small differences, i.e. a greater low angle grain boundary fraction in unirradiated SiC. It was, thus, concluded that SiC layers with grain boundary distributions susceptible to Ag-110m release were present prior to irradiation. Finally, irradiation parameters were found to have little effect on the association of fission product precipitates with specific grain boundary types.

  7. THE PRESENT CONDITION OF SMALL WATER RETENTION AND THE PROSPECTS OF ITS DEVELOPMENT USING THE EXAMPLE OF THE PODLASKIE VOIVODESHIP

    Directory of Open Access Journals (Sweden)

    Joanna Szczykowska

    2014-07-01

    Full Text Available The necessity and purposefulness of the investments related to water retention are justified mostly due to the preservation of the environment equilibrium as well as due to its farming, anti-flood, landscape and recreation aspects. Reasonable water management where various forms of retention are used gives large chances for the mitigation of the effects of unfavorable phenomena related to its insufficient amount. The creation of plans regarding the formation of reservoirs accumulating water is not necessarily synonymous with their realization. The reason of problems connected with the implementation of plans regarding the formation of new reservoirs lies mainly in financial measures and in problems with obtaining them. Water deficit in Poland is the reason for which the principles of its national usage need to be complied with. Realization of plans at both Voivodeship and municipality level that are focused on small retention will contribute to considerable increase in the retention capacity and will enable considerable increase in available resources in hydrographic catchments of both the characterized area and the entire country. The paper presents the characteristics of the present state and assumes the perspective development of small water retention in the Podlaskie Voivodeship using the example of the Podlaskie Voivodeship.

  8. Induced sporicidal activity of chlorhexidine against Clostridium difficile spores under altered physical and chemical conditions.

    Directory of Open Access Journals (Sweden)

    Michelle M Nerandzic

    Full Text Available Chlorhexidine is a broad-spectrum antimicrobial commonly used to disinfect the skin of patients to reduce the risk of healthcare-associated infections. Because chlorhexidine is not sporicidal, it is not anticipated that it would have an impact on skin contamination with Clostridium difficile, the most important cause of healthcare-associated diarrhea. However, although chlorhexidine is not sporicidal as it is used in healthcare settings, it has been reported to kill spores of Bacillus species under altered physical and chemical conditions that disrupt the spore's protective barriers (e.g., heat, ultrasonication, alcohol, or elevated pH. Here, we tested the hypothesis that similarly altered physical and chemical conditions result in enhanced sporicidal activity of chlorhexidine against C. difficile spores.C. difficile spores became susceptible to heat killing at 80 °C within 15 minutes in the presence of chlorhexidine, as opposed to spores suspended in water which remained viable. The extent to which the spores were reduced was directly proportional to the concentration of chlorhexidine in solution, with no viable spores recovered after 15 minutes of incubation in 0.04%-0.0004% w/v chlorhexidine solutions at 80 °C. Reduction of spores exposed to 4% w/v chlorhexidine solutions at moderate temperatures (37 °C and 55 °C was enhanced by the presence of 70% ethanol. However, complete elimination of spores was not achieved until 3 hours of incubation at 55 °C. Elevating the pH to ≥9.5 significantly enhanced the killing of spores in either aqueous or alcoholic chlorhexidine solutions.Physical and chemical conditions that alter the protective barriers of C. difficile spores convey sporicidal activity to chlorhexidine. Further studies are necessary to identify additional agents that may allow chlorhexidine to reach its target within the spore.

  9. Evaluation of cell culture flasks designed for experiment under altered gravity-vector conditions.

    Science.gov (United States)

    Gyotoku, Jun-Ichiro; Nagase, Mutsumu; Ando, Noboru; Tanigaki, Fumiaki; Takaoki, Muneo

    2003-10-01

    Cell culture flasks applicable for altered gravity conditions, such as centrifugation, clino-rotation or microgravity in space, were manufactured for trial. The flask has flat polystyrene surface for monolayer culture and gas-permeable film window on the opposite face. The space in-between consists the culture chamber to be filled with liquid medium. To reduce the water loss and bubble formation in the culture fluid, another gas permeable window was placed on top to form a space where distilled water may be filled. The double-decker culture flask can be used for both space and ground-based experiments in common.

  10. Experimental Evaluation of the Surface Alteration of Gasket Samples under Operative Conditions

    Directory of Open Access Journals (Sweden)

    M.C. Bignozzi

    2015-12-01

    Full Text Available This paper investigates the surface alteration of gasket samples commercialized by two alternative producers. These gaskets, in polymeric materials, are installed in process plants used for cleaning tires molds by a pioneering ultrasonic process. They are exposed to a combination of ultrasonic waves, temperature, humidity and acid attack causing several erosion phenomena. Their surface degradation under ordinary operative conditions was investigated using mechanical and tribological tests. The experimental characterization was performed by optical microscopy, scanning electron microscopy, thermograms, differential scanning calorimetry curves and infrared spectra aiming at defining the specific mechanics of wearing. As a conclusion, it was possible to state that even if samples exhibit similar chemical structures, their thermal and mechanical properties as well as their geometric dimensions are different. Such differences in the materials might cause various unexpected wear behaviors when gaskets are employed in the same working conditions.


  11. EEG oscillatory states: universality, uniqueness and specificity across healthy-normal, altered and pathological brain conditions.

    Directory of Open Access Journals (Sweden)

    Alexander A Fingelkurts

    Full Text Available For the first time the dynamic repertoires and oscillatory types of local EEG states in 13 diverse conditions (examined over 9 studies that covered healthy-normal, altered and pathological brain states were quantified within the same methodological and conceptual framework. EEG oscillatory states were assessed by the probability-classification analysis of short-term EEG spectral patterns. The results demonstrated that brain activity consists of a limited repertoire of local EEG states in any of the examined conditions. The size of the state repertoires was associated with changes in cognition and vigilance or neuropsychopathologic conditions. Additionally universal, optional and unique EEG states across 13 diverse conditions were observed. It was demonstrated also that EEG oscillations which constituted EEG states were characteristic for different groups of conditions in accordance to oscillations' functional significance. The results suggested that (a there is a limit in the number of local states available to the cortex and many ways in which these local states can rearrange themselves and still produce the same global state and (b EEG individuality is determined by varying proportions of universal, optional and unique oscillatory states. The results enriched our understanding about dynamic microstructure of EEG-signal.

  12. EEG Oscillatory States: Universality, Uniqueness and Specificity across Healthy-Normal, Altered and Pathological Brain Conditions

    Science.gov (United States)

    Fingelkurts, Alexander A.; Fingelkurts, Andrew A.

    2014-01-01

    For the first time the dynamic repertoires and oscillatory types of local EEG states in 13 diverse conditions (examined over 9 studies) that covered healthy-normal, altered and pathological brain states were quantified within the same methodological and conceptual framework. EEG oscillatory states were assessed by the probability-classification analysis of short-term EEG spectral patterns. The results demonstrated that brain activity consists of a limited repertoire of local EEG states in any of the examined conditions. The size of the state repertoires was associated with changes in cognition and vigilance or neuropsychopathologic conditions. Additionally universal, optional and unique EEG states across 13 diverse conditions were observed. It was demonstrated also that EEG oscillations which constituted EEG states were characteristic for different groups of conditions in accordance to oscillations’ functional significance. The results suggested that (a) there is a limit in the number of local states available to the cortex and many ways in which these local states can rearrange themselves and still produce the same global state and (b) EEG individuality is determined by varying proportions of universal, optional and unique oscillatory states. The results enriched our understanding about dynamic microstructure of EEG-signal. PMID:24505292

  13. Retentive strength of fiber-reinforced composite posts with composite resin cores: Effect of remaining coronal structure and root canal dentin conditioning protocols.

    Science.gov (United States)

    Saker, Samah; Özcan, Mutlu

    2015-12-01

    The prognosis of a fixed dental prosthesis cemented to endodontically treated teeth is primarily determined by the presence of a ferrule on the tooth. Adhesion of the post in the root canal, conditioning methods for the canal and the amount of coronal structure could also be decisive on survival of reconstructions cemented on endodontically treated teeth. The purpose of this in vitro study was to test the effect of remaining coronal structure on the retention of airborne-particle abraded fiber-reinforced composite resin posts built up with composite resin cores after the treatment of root canal dentin with different conditioning protocols. One hundred and fifty extracted human teeth with single root canal space were endodontically treated and divided into 3 groups as follows: group CEJ: the teeth were sectioned at the level of cementoenamel junction (CEJ); group CEJ1: the teeth were sectioned 1 mm above the CEJ; group CEJ2: the teeth were sectioned 2 mm above the CEJ. Each group was further divided into 5 subgroups (n=10 per group) according to the root canal treatments as follows: group C: no conditioning (control); group PH: conditioning with 37% phosphoric acid gel for 15 seconds; group E: conditioning with 17% ethylenediaminetetraacetic acid (EDTA) for 60 seconds; group CHX: conditioning with 2% chlorhexidine (CHX) for 60 seconds; group Q: conditioning with combination of 2% CHX with 17% EDTA and a surfactant solution for 60 seconds. Glass fiber-reinforced composite resin posts were airborne-particle abraded and luted to the root canal dentin with a self-adhesive resin cement (RelyX Unicem). The retentive force was tested by applying a tensile load parallel to the long axis of these posts at a crosshead speed of 2 mm/min. Two-way ANOVA and the Tukey HSD post hoc test were used to analyze the data. The highest retention (N) was obtained with the CHX-EDTA conditioned group (374.7 ±29.8) followed by 17% EDTA (367.9 ±33.3) conditioning when 2 mm remaining

  14. Altered Clock and Lipid Metabolism-Related Genes in Atherosclerotic Mice Kept with Abnormal Lighting Condition

    Directory of Open Access Journals (Sweden)

    Zhu Zhu

    2016-01-01

    Full Text Available Background. The risk of atherosclerosis is elevated in abnormal lipid metabolism and circadian rhythm disorder. We investigated whether abnormal lighting condition would have influenced the circadian expression of clock genes and clock-controlled lipid metabolism-related genes in ApoE-KO mice. Methods. A mouse model of atherosclerosis with circadian clock genes expression disorder was established using ApoE-KO mice (ApoE-KO LD/DL mice by altering exposure to light. C57 BL/6J mice (C57 mice and ApoE-KO mice (ApoE-KO mice exposed to normal day and night and normal diet served as control mice. According to zeitgeber time samples were acquired, to test atheromatous plaque formation, serum lipids levels and rhythmicity, clock genes, and lipid metabolism-related genes along with Sirtuin 1 (Sirt1 levels and rhythmicity. Results. Atherosclerosis plaques were formed in the aortic arch of ApoE-KO LD/DL mice. The serum lipids levels and oscillations in ApoE-KO LD/DL mice were altered, along with the levels and diurnal oscillations of circadian genes, lipid metabolism-associated genes, and Sirt1 compared with the control mice. Conclusions. Abnormal exposure to light aggravated plaque formation and exacerbated disorders of serum lipids and clock genes, lipid metabolism genes and Sirt1 levels, and circadian oscillation.

  15. Ghrelin-Reactive Immunoglobulins in Conditions of Altered Appetite and Energy Balance

    Science.gov (United States)

    Fetissov, Sergueï O.; Lucas, Nicolas; Legrand, Romain

    2017-01-01

    Part of circulating ghrelin is bound to immunoglobulins (Ig) protecting it from degradation and preserving its functional activity. This review summarizes the data on ghrelin- and desacyl-ghrelin-reactive IgG in conditions of altered appetite and energy balance. Plasma levels and affinity kinetics of such IgG were compared in patients with obesity and anorexia nervosa (AN) and in animal models of obesity including ob/ob mice, high-fat diet-induced obese mice, and obese Zucker rats as well as in mice after chronic food restriction and activity-based anorexia and in rats with methotrexate-induced anorexia. We show that plasmatic IgG in both obese humans and animals are characterized by increased affinity for ghrelin. In contrast, patients with AN and anorectic rodents all show lower affinity of ghrelin- and desacyl-ghrelin-reactive IgG, respectively, the changes which were not observed in non-anorectic, chronically starved mice. We also show that affinity of ghrelin-reactive IgG correlate with plasma levels of ghrelin. These data point to common mechanisms underlying modifications of affinity kinetics properties of ghrelin-reactive IgG during chronic alterations of energy balance in humans and rodents and support a functional role of such autoantibodies in ghrelin-mediated regulation of appetite. PMID:28191004

  16. Altered Clock and Lipid Metabolism-Related Genes in Atherosclerotic Mice Kept with Abnormal Lighting Condition.

    Science.gov (United States)

    Zhu, Zhu; Hua, Bingxuan; Shang, Zhanxian; Yuan, Gongsheng; Xu, Lirong; Li, Ermin; Li, Xiaobo; Sun, Ning; Yan, Zuoqin; Qian, Ruizhe; Lu, Chao

    2016-01-01

    Background. The risk of atherosclerosis is elevated in abnormal lipid metabolism and circadian rhythm disorder. We investigated whether abnormal lighting condition would have influenced the circadian expression of clock genes and clock-controlled lipid metabolism-related genes in ApoE-KO mice. Methods. A mouse model of atherosclerosis with circadian clock genes expression disorder was established using ApoE-KO mice (ApoE-KO LD/DL mice) by altering exposure to light. C57 BL/6J mice (C57 mice) and ApoE-KO mice (ApoE-KO mice) exposed to normal day and night and normal diet served as control mice. According to zeitgeber time samples were acquired, to test atheromatous plaque formation, serum lipids levels and rhythmicity, clock genes, and lipid metabolism-related genes along with Sirtuin 1 (Sirt1) levels and rhythmicity. Results. Atherosclerosis plaques were formed in the aortic arch of ApoE-KO LD/DL mice. The serum lipids levels and oscillations in ApoE-KO LD/DL mice were altered, along with the levels and diurnal oscillations of circadian genes, lipid metabolism-associated genes, and Sirt1 compared with the control mice. Conclusions. Abnormal exposure to light aggravated plaque formation and exacerbated disorders of serum lipids and clock genes, lipid metabolism genes and Sirt1 levels, and circadian oscillation.

  17. Olfactory aversive conditioning alters olfactory bulb mitral/tufted cell glomerular odor responses

    Directory of Open Access Journals (Sweden)

    Max L Fletcher

    2012-03-01

    Full Text Available The anatomical organization of receptor neuron input into the olfactory bulb (OB allows odor information to be transformed into an odorant-specific spatial map of mitral/tufted cell glomerular activity at the upper level of the olfactory bulb. In other sensory systems, neuronal representations of stimuli can be reorganized or enhanced following learning. While the mammalian OB has been shown to undergo experience-dependent plasticity at the glomerular level, it is still unclear if similar representational change occurs within mitral/tufted cell glomerular odor representations following learning. To address this, odorant-evoked glomerular activity patterns were imaged in mice expressing a GFP-based calcium indicator (GCaMP2 in OB mitral/tufted cells. Glomerular odor responses were imaged before and after olfactory associative conditioning to aversive foot shock. Following conditioning, we found no overall reorganization of the glomerular representation. Training, however, did significantly alter the amplitudes of individual glomeruli within the representation in mice in which the odor was presented together with foot shock. Further, the specific pairing of foot shock with odor presentations lead to increased responses primarily in initially weakly activated glomeruli. Overall, these results suggest that associative conditioning can enhance the initial representation of odors within the olfactory bulb by enhancing responses to the learned odor in some glomeruli.

  18. AFM characterization of nanobubble formation and slip condition in oxygenated and electrokinetically altered fluids.

    Science.gov (United States)

    Bhushan, Bharat; Pan, Yunlu; Daniels, Stephanie

    2013-02-15

    Nanobubbles are gas-filled features that spontaneously form at the interface of hydrophobic surfaces and aqueous solutions. In this study, an atomic force microscope (AFM) was used to characterize the morphology of nanobubbles formed on hydrophobic polystyrene (PS) and octadecyltrichlorosilane (OTS) films immersed in DI water, saline, saline with oxygen and an electrokinetically altered saline solution produced with Taylor-Couette-Poiseuille flow under elevated oxygen pressure. AFM force spectroscopy was used to evaluate hydrodynamic and electrostatic forces and boundary slip condition in various fluids. The effect of solution, electric field and surface charge on shape, size and density of nanobubbles as well as slip length was quantified and the results and underlying mechanisms are presented in this paper.

  19. Low temperature conditioning of garlic (Allium sativum L. "seed" cloves induces alterations in sprouts proteome

    Directory of Open Access Journals (Sweden)

    Miguel David Dufoo-Hurtado

    2015-05-01

    Full Text Available Low-temperature conditioning of garlic seed cloves substitutes the initial climatic requirements of the crop and accelerates the cycle. We have reported that seed bulbs from ‘Coreano’ variety conditioned at 5 °C for five weeks reduces growth and plant weight as well as the crop yields and increases the synthesis of phenolic compounds and anthocyanins. Therefore, this treatment suggests a cold stress. Plant acclimation to stress is associated with deep changes in proteome composition. Since proteins are directly involved in plant stress response, proteomics studies can significantly contribute to unravel the possible relationships between protein abundance and plant stress acclimation. The aim of this work was to study the changes in the protein profiles of garlic seed cloves subjected to conditioning at low-temperature using proteomics approach. Two sets of garlic bulbs were used, one set was stored at room temperature (23 °C, and the other was conditioned at low temperature (5 °C for five weeks. Total soluble proteins were extracted from sprouts of cloves and separated by two-dimensional gel electrophoresis. Protein spots showing statistically significant changes in abundance were analyzed by LC-ESI-MS/MS and identified by database search analysis using the Mascot search engine. The results revealed that low-temperature conditioning of garlic seed cloves causes alterations in the accumulation of proteins involved in different physiological processes such as cellular growth, antioxidative/oxidative state, macromolecules transport, protein folding and transcription regulation process. The metabolic pathways affected include protein biosynthesis and quality control system, photosynthesis, photorespiration, energy production, and carbohydrate and nucleotide metabolism. These processes can work cooperatively to establish a new cellular homeostasis that might be related with the physiological and biochemical changes observed in previous

  20. Low temperature conditioning of garlic (Allium sativum L.) "seed" cloves induces alterations in sprouts proteome.

    Science.gov (United States)

    Dufoo-Hurtado, Miguel D; Huerta-Ocampo, José Á; Barrera-Pacheco, Alberto; Barba de la Rosa, Ana P; Mercado-Silva, Edmundo M

    2015-01-01

    Low-temperature conditioning of garlic "seed" cloves substitutes the initial climatic requirements of the crop and accelerates the cycle. We have reported that "seed" bulbs from "Coreano" variety conditioned at 5°C for 5 weeks reduces growth and plant weight as well as the crop yields and increases the synthesis of phenolic compounds and anthocyanins. Therefore, this treatment suggests a cold stress. Plant acclimation to stress is associated with deep changes in proteome composition. Since proteins are directly involved in plant stress response, proteomics studies can significantly contribute to unravel the possible relationships between protein abundance and plant stress acclimation. The aim of this work was to study the changes in the protein profiles of garlic "seed" cloves subjected to conditioning at low-temperature using proteomics approach. Two sets of garlic bulbs were used, one set was stored at room temperature (23°C), and the other was conditioned at low temperature (5°C) for 5 weeks. Total soluble proteins were extracted from sprouts of cloves and separated by two-dimensional gel electrophoresis. Protein spots showing statistically significant changes in abundance were analyzed by LC-ESI-MS/MS and identified by database search analysis using the Mascot search engine. The results revealed that low-temperature conditioning of garlic "seed" cloves causes alterations in the accumulation of proteins involved in different physiological processes such as cellular growth, antioxidative/oxidative state, macromolecules transport, protein folding and transcription regulation process. The metabolic pathways affected include protein biosynthesis and quality control system, photosynthesis, photorespiration, energy production, and carbohydrate and nucleotide metabolism. These processes can work cooperatively to establish a new cellular homeostasis that might be related with the physiological and biochemical changes observed in previous studies.

  1. Evaluation of tensile retention of Y-TZP crowns after long-term aging: effect of the core substrate and crown surface conditioning.

    Science.gov (United States)

    Amaral, R; Rippe, M; Oliveira, B G; Cesar, P F; Bottino, M A; Valandro, L F

    2014-01-01

    This study evaluated the effect of the core substrate type (dentin and composite resin) on the retention of crowns made of yttrium oxide stabilized tetragonal zirconia polycrystal (Y-TZP), submitted to three inner surface conditionings. For this purpose, 72 freshly extracted molars were embedded in acrylic resin, perpendicular to the long axis, and prepared for full crowns: 36 specimens had crown preparations in dentin; the remaining 36 teeth had the crowns removed, and crown preparations were reconstructed with composite resin plus fiber posts with dimensions identical to the prepared dentin. The preparations were impressed using addition silicone, and 72 Y-TZP copings for the tensile test were produced. Cementation was performed with a dual-cured cement containing phosphate monomers. For cementation, the crown preparation (dentin or resin) was conditioned with the adhesive system, and the ceramic was subjected to one of three surface treatments: isopropyl alcohol, tribochemical silica coating, or thin low-fusing glassy porcelain layer application plus silanization. After 24 hours, all specimens were submitted to thermocycling (6000 cycles) and placed in a special tensile testing device in a universal testing machine to determine failure loads. The failure modes of all samples were analyzed under a stereomicroscope. Two-way analysis of variance showed that the surface treatment and substrate type (α=0.05) affected the tensile retention results. The dentin substrate presented the highest tensile retention values, regardless of the surface treatment. When the substrate was resin, the tribochemical silica coating and low-fusing glaze application plus silanization groups showed the higher retention values.

  2. Baclofen alters gustatory discrimination capabilities and induces a conditioned taste aversion (CTA

    Directory of Open Access Journals (Sweden)

    Wilson Gina N

    2011-12-01

    Full Text Available Abstract Background Studies intending to measure drug-induced changes in learning and memory are challenged to parse out the effects of drugs on sensory, motor, and associative systems in the brain. In the context of conditioned taste aversion (CTA, drugs that alter the sensorium of subjects and affect their ability to taste and/or feel malaise may limit the ability of investigators to make conclusions about associative effects of these substances. Since the GABAergic system is implicated in inhibition, the authors were hopeful to use the GABA agonist, baclofen (BAC, to enhance extinction of a CTA, but first a preliminary evaluation of BAC's peripheral effects on animals' sensorium had to be completed due to a lack of published literature in this area. Findings Our first experiment aimed to evaluate the extent to which the GABAB agonist, BAC, altered the ability of rats to differentiate between 0.3% and 0.6% saccharin (SAC in a two bottle preference test. Here we report that 2 or 3 mg/kg (i.p. BAC, but not 1 mg/kg BAC, impaired animals' gustatory discrimination abilities in this task. Furthermore, when SAC consumption was preceded by 2 or 3 mg/kg (i.p. BAC, rats depressed their subsequent SAC drinking. A second experiment evaluated if the suppression of SAC and water drinking (revealed in Experiment 1 was mediated by amnesiac effects of BAC or whether BAC possessed US properties in the context of the CTA paradigm. The time necessary to reach an asymptotic level of CTA extinction was not significantly different in those animals that received the 3 mg/kg dose of BAC compared to more conventionally SAC + lithium chloride (LiCl, 81 mg/kg conditioned animals. Conclusions Our findings were not consistent with a simple amnesia-of-neophobia explanation. Instead, results indicated that 2 and 3 mg/kg (i.p. BAC were capable of inducing a CTA, which was extinguishable via repeated presentations of SAC only. Our data indicate that, depending on the dose, BAC

  3. Altered acetylation and succinylation profiles in Corynebacterium glutamicum in response to conditions inducing glutamate overproduction.

    Science.gov (United States)

    Mizuno, Yuta; Nagano-Shoji, Megumi; Kubo, Shosei; Kawamura, Yumi; Yoshida, Ayako; Kawasaki, Hisashi; Nishiyama, Makoto; Yoshida, Minoru; Kosono, Saori

    2016-02-01

    The bacterium Corynebacterium glutamicum is utilized during industrial fermentation to produce amino acids such as L-glutamate. During L-glutamate fermentation, C. glutamicum changes the flux of central carbon metabolism to favor L-glutamate production, but the molecular mechanisms that explain these flux changes remain largely unknown. Here, we found that the profiles of two major lysine acyl modifications were significantly altered upon glutamate overproduction in C. glutamicum; acetylation decreased, whereas succinylation increased. A label-free semi-quantitative proteomic analysis identified 604 acetylated proteins with 1328 unique acetylation sites and 288 succinylated proteins with 651 unique succinylation sites. Acetylation and succinylation targeted enzymes in central carbon metabolic pathways that are directly related to glutamate production, including the 2-oxoglutarate dehydrogenase complex (ODHC), a key enzyme regulating glutamate overproduction. Structural mapping revealed that several critical lysine residues in the ODHC components were susceptible to acetylation and succinylation. Furthermore, induction of glutamate production was associated with changes in the extent of acetylation and succinylation of lysine, suggesting that these modifications may affect the activity of enzymes involved in glutamate production. Deletion of phosphotransacetylase decreased the extent of protein acetylation in nonproducing condition, suggesting that acetyl phosphate-dependent acetylation is active in C. glutamicum. However, no effect was observed on the profiles of acetylation and succinylation in glutamate-producing condition upon disruption of acetyl phosphate metabolism or deacetylase homologs. It was considered likely that the reduced acetylation in glutamate-producing condition may reflect metabolic states where the flux through acid-producing pathways is very low, and substrates for acetylation do not accumulate in the cell. Succinylation would occur more

  4. Pavlovian conditioning of morphine-induced alterations of immune status: evidence for peripheral beta-adrenergic receptor involvement.

    Science.gov (United States)

    Coussons-Read, M E; Dykstra, L A; Lysle, D T

    1994-09-01

    The present studies examined the involvement of peripheral beta-adrenergic receptor activity in the establishment and expression of conditioned morphine-induced alterations of immune status. Previous work in our laboratory has shown that morphine's immunomodulatory effects can become conditioned to environmental stimuli which predict drug administration. These immune alterations include conditioned changes in natural killer cell activity, interleukin-2 production, and mitogen-induced lymphocyte proliferation. During the training phase of these experiments, Lewis rats received two conditioning sessions during which a subcutaneous injection of 15 mg/kg morphine sulfate was paired with exposure to a distinctive environment. On the test day, rats were reexposed to the conditioned stimulus prior to sacrifice. Saline or nadolol (0.002, 0.02, 0.2, or 2.0 mg/kg) was administered either prior to the training sessions or prior to the test session. Administration of nadolol prior to training did not affect the development of conditioned alterations of immune status. Conversely, nadolol administration prior to testing completely attenuated the expression of a subset of the conditioned morphine-induced changes in immune status. Taken together, these studies suggest that whereas peripheral beta-adrenergic receptor activity is not required for the establishment of conditioned morphine-induced alterations of immune status, it is involved in the expression of a subset of these conditioned immunomodulatory effects.

  5. Altered differentiation and paracrine stimulation of mammary epithelial cell proliferation by conditionally activated Smoothened.

    Science.gov (United States)

    Visbal, Adriana P; LaMarca, Heather L; Villanueva, Hugo; Toneff, Michael J; Li, Yi; Rosen, Jeffrey M; Lewis, Michael T

    2011-04-01

    The Hedgehog (Hh) signaling network is critical for patterning and organogenesis in mammals, and has been implicated in a variety of cancers. Smoothened (Smo), the gene encoding the principal signal transducer, is overexpressed frequently in breast cancer, and constitutive activation in MMTV-SmoM2 transgenic mice caused alterations in mammary gland morphology, increased proliferation, and changes in stem/progenitor cell number. Both in transgenic mice and in clinical specimens, proliferative cells did not usually express detectable Smo, suggesting the hypothesis that Smo functioned in a non-cell autonomous manner to stimulate proliferation. Here, we employed a genetically tagged mouse model carrying a Cre-recombinase-dependent conditional allele of constitutively active Smo (SmoM2) to test this hypothesis. MMTV-Cre- or adenoviral-Cre-mediated SmoM2 expression in the luminal epithelium, but not in the myoepithelium, was required for the hyper-proliferative phenotypes. High levels of proliferation were observed in cells adjacent or in close-proximity to Smo expressing cells demonstrating that SmoM2 expressing cells were stimulating proliferation via a paracrine or juxtacrine mechanism. In contrast, Smo expression altered luminal cell differentiation in a cell-autonomous manner. SmoM2 expressing cells, purified by fluorescence activated cell sorting (FACS) via the genetic fluorescent tag, expressed high levels of Ptch2, Gli1, Gli2, Jag2 and Dll-1, and lower levels of Notch4 and Hes6, in comparison to wildtype cells. These studies provide insight into the mechanism of Smo activation in the mammary gland and its possible roles in breast tumorigenesis. In addition, these results also have potential implications for the interpretation of proliferative phenotypes commonly observed in other organs as a consequence of hedgehog signaling activation.

  6. Alterations in plasma lipid profile patterns in head and neck cancer and oral precancerous conditions

    Directory of Open Access Journals (Sweden)

    Patel Prabhudas

    2004-01-01

    Full Text Available BACKGROUND : The changes in lipid profile have long been associated with cancer because lipids play a key role in maintenance of cell integrity. AIMS : The present study evaluated alterations in plasma lipid profile in untreated head and neck cancer patients as well as patients with oral precancerous conditions (OPC and its association with habit of tobacco consumption. MATERIAL AND METHODS : This hospital-based case control study included 184 head and neck cancer patients, 153 patients with OPC and 52 controls. Plasma lipids including: (i Total cholesterol, (ii LDL cholesterol (LDLC, (iii HDL cholesterol (HDLC (iv VLDL cholesterol (VLDLC and (v triglycerides were analysed by spectrophotometric kits. STATISTICAL ANALYSIS USED : Student′s t-test was performed to compare mean values of the parameters. RESULTS : A significant decrease in plasma total cholesterol and HDLC was observed in cancer patients (P=0.008 and P=0.000 respectively as well as in patients with OPC (P=0.014 and P=0.000, respectively as compared to the controls. The plasma VLDL and triglycerides levels were significantly lower in cancer patients as compared to the patients with OPC (P=0.04 and controls (P=0.059. The tobacco habituates showed lower plasma lipid levels than the non-habituates. Our data strengthen the evidence of an inverse relationship between plasma lipid levels and head and neck malignancies as well as OPC. CONCLUSION :The lower levels of plasma cholesterol and other lipid constituents in patients might be due to their increased utilization by neoplastic cells for new membrane biogenesis. The findings strongly warrant an in-depth study of alterations in plasma lipid profile in head neck cancer patients.

  7. Surface morphology changes and deuterium retention in Toughened, Fine-grained Recrystallized Tungsten under high-flux irradiation conditions

    Energy Technology Data Exchange (ETDEWEB)

    Oya, M., E-mail: ohya@st.eie.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Lee, H.T.; Ueda, Y. [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); Kurishita, H. [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Oyaidzu, M.; Hayashi, T. [Fusion Research and Development Directorate, International Fusion Energy Research Center, Japan Atomic Energy Agency, Rokkasho-mura, Aomori 039-3212 (Japan); Yoshida, N. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka (Japan); Morgan, T.W.; De Temmerman, G. [FOM Institute DIFFER Dutch Institute for Fundamental Energy Research, Nieuwegein 3439 MN (Netherlands)

    2015-08-15

    Surface morphology changes and deuterium (D) retention in Toughened, Fine-Grained Recrystallized Tungsten (TFGR W) with TaC dispersoids (W-TaC) and pure tungsten exposed to D plasmas to a fluence of 10{sup 26} D/m{sup 2} s were studied as a function of the D ion flux (10{sup 22}–10{sup 24} D/m{sup 2} s). As the flux increased from 10{sup 22} D/m{sup 2} s to 10{sup 24} D/m{sup 2} s, the numbers of blisters increased for both materials. However, smaller blisters were observed on W-TaC compared to pure W. In W-TaC, cracks beneath the surface along grain boundaries were observed, which were comparable to the blister sizes. The reason for the smaller blister sizes may arise from smaller grain sizes of W-TaC. In addition, reduction of the D retention in W-TaC was observed for higher flux exposures. D depth profiles indicate this reduction arises due to decrease in trapping in the bulk.

  8. Microbial and biochemical alterations due to storage of deep-sea sediments under ambient tropical conditions

    Digital Repository Service at National Institute of Oceanography (India)

    Das, A.; Fernandes, C.E.G.; Naik, S.S.; Mourya, B.S.; Sujith, P.P.; Sharma, R.; LokaBharathi, P.A.

    stabilization. Protein: carbohydrate ratio fluctuated considerably. The four samples responded distinctively to storage, suggesting dependence of variations on inherent sedimentary properties. Though bacteriologically and biochemically altered, the integrity...

  9. Niacin alters the ruminal microbial composition of cattle under high-concentrate condition

    Directory of Open Access Journals (Sweden)

    Dan Luo

    2017-06-01

    Full Text Available To understand the effects of niacin on the ruminal microbial ecology of cattle under high-concentrate diet condition, Illumina MiSeq sequencing technology was used. Three cattle with rumen cannula were used in a 3 × 3 Latin-square design trial. Three diets were fed to these cattle during 3 periods for 3 days, respectively: high-forage diet (HF; forage-to-concentrate ratio = 80:20, high-concentrate diet (HC; forage-to-concentrate ratio = 20:80, and HC supplemented with 800 mg/kg niacin (HCN. Ruminal pH was measured before feeding and every 2 h after initiating feeding. Ruminal fluid was sampled at the end of each period for microbial DNA extraction. Overall, our findings revealed that subacute ruminal acidosis (SARA was induced and the α-diversity of ruminal bacterial community decreased in the cattle of HC group. Adding niacin in HC could relieve the symptoms of SARA in the cattle but the ruminal pH value and the Shannon index of ruminal bacterial community of HCN group were still lower than those of HF group. Whatever the diet was, the ruminal bacterial community of cattle was dominated by Bacteroidetes, Firmicutes and Proteobacteria. High-concentrate diet significantly increased the abundance of Prevotella, and decreased the abundance of Paraprevotella, Sporobacter, Ruminococcus and Treponema than HF. Compared with HC, HCN had a trend to decrease the percentage of Prevotella, and to increase the abundance of Succiniclasticum, Acetivibrio and Treponema. Increasing concentrate ratio could decrease ruminal pH value, and change the ruminal microbial composition. Adding niacin in HC could increase the ruminal pH value, alter the ruminal microbial composition.

  10. Spatial structuring of an evolving life-history strategy under altered environmental conditions.

    Science.gov (United States)

    Hegg, Jens C; Kennedy, Brian P; Chittaro, Paul M; Zabel, Richard W

    2013-08-01

    Human disturbances to ecosystems have created challenges to populations worldwide, forcing them to respond phenotypically in ways that increase their fitness under current conditions. One approach to examining population responses to disturbance in species with complex life histories is to study species that exhibit spatial patterns in their phenotypic response across populations or demes. In this study, we investigate a threatened population of fall chinook salmon (Oncorhynchus tshawytscha) in the Snake River of Idaho, in which a significant fraction of the juvenile population have been shown to exhibit a yearling out-migration strategy which had not previously been thought to exist. It has been suggested that dam-related environmental changes may have altered the selective pressures experienced by out-migrating fall chinook, driving evolution of a later and more selectively advantageous migration strategy. Using isotopic analysis of otoliths from returning adult spawners, we reconstructed the locations of individual fish at three major juvenile life stages to determine if the representation of the yearling life history was geographically structured within the population. We reconstructed juvenile locations for natal, rearing and overwintering life stages in each of the major spawning areas in the basin. Our results indicate that the yearling life-history strategy is predominantly represented within one of the main spawning regions, the Clearwater River, rather than being distributed throughout the basin. Previous studies have shown the Clearwater River to have cooler temperatures, later hatch dates, and later outmigration of juveniles, indicating a link between environment and expression of the yearling life history. Our data suggest that this new yearling life history may be disproportionally represented in returning adult spawners, indicating selection for this life history within the population.

  11. Influence of sludge retention time at constant food to microorganisms ratio on membrane bioreactor performances under stable and unstable state conditions.

    Science.gov (United States)

    Villain, Maud; Marrot, Benoît

    2013-01-01

    Food to microorganisms ratio (F/M) and sludge retention time (SRT) are known to affect in different ways biomass growth, bioactivities and foulants characteristics. Thus the aim of this study was to dissociate the effects of SRT from those of F/M ratio on lab-scale membrane bioreactors performances during stable and unstable state. Two acclimations were stabilized at a SRT of either 20 or 50 d with a constant F/M ratio of 0.2 kg(COD)kg(MLVSS)(-1) d(-1). During stable state, a higher N-NH(4)(+) removal rate (78%) was obtained at SRT of 50 d as an easier autotroph development was observed. Soluble microbial products (SMPs) release was double at 50 d with a majority of polysaccharides (49% of total SMP). The unstable conditions consisted in F/M ratio changes and operation without air and nutrient. Autotrophs were highly affected by the tested disturbances and SMP retention on membrane surface exhibited consistent changes during the performed stresses.

  12. Alteration of media composition and light conditions change morphology, metabolic profile, and beauvericin biosynthesis in Cordyceps bassiana mycelium.

    Science.gov (United States)

    Hyun, Sun-Hee; Lee, Seok-Young; Park, Shin Jung; Kim, Da Yeon; Chun, Young-Jin; Sung, Gi-Ho; Kim, Seong Hwan; Choi, Hyung-Kyoon

    2013-01-01

    Metabolic alterations of Cordyceps bassiana mycelium were investigated under the following culture medium and light conditions: dextrose agar supplemented with 0.5% yeast extract (SDAY) medium with light (SL), SDAY medium without light (SD), nut medium without light (ND), and iron-supplemented SDAY medium without light (FD). The levels of asparagine, aspartic acid, glutamic acid, glutamine, histidine, lysine, ornithine, and proline were significantly higher under SD and SL conditions. The levels of most of the alcohols, saturated fatty acids, unsaturated fatty acids, fatty acid esters, sterols, and terpenes were higher under the ND condition than in the other conditions, but beauvericin was not detectable under the ND condition. The FD condition was favorable for the enhanced production of aminomalonic acid, malic acid, mannonic acid, and erythritol. Thus, the metabolic characteristics of C. bassiana can be manipulated by varying the cultivation conditions, rendering this fungus potentially favorable as a nutraceutical and medicinal resource.

  13. Suitability of a Coupled Hydrodynamic Water Quality Model to Predict Changes in Water Quality from Altered Meteorological Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Leon van der Linden

    2015-01-01

    Full Text Available Downscaled climate scenarios can be used to inform management decisions on investment in infrastructure or alternative water sources within water supply systems. Appropriate models of the system components, such as catchments, rivers, lakes and reservoirs, are required. The climatic sensitivity of the coupled hydrodynamic water quality model ELCOM-CAEDYM was investigated, by incrementally altering boundary conditions, to determine its suitability for evaluating climate change impacts. A series of simulations were run with altered boundary condition inputs for the reservoir. Air and inflowing water temperature (TEMP, wind speed (WIND and reservoir inflow and outflow volumes (FLOW were altered to investigate the sensitivity of these key drivers over relevant domains. The simulated water quality variables responded in broadly plausible ways to the altered boundary conditions; sensitivity of the simulated cyanobacteria population to increases in temperature was similar to published values. However the negative response of total chlorophyll-a suggested by the model was not supported by an empirical analysis of climatic sensitivity. This study demonstrated that ELCOM-CAEDYM is sensitive to climate drivers and may be suitable for use in climate impact studies. It is recommended that the influence of structural and parameter derived uncertainty on the results be evaluated. Important factors in determining phytoplankton growth were identified and the importance of inflowing water quality was emphasized.

  14. Tissue biochemical alterations of Cyprinus carpio exposed to commercial herbicide containing clomazone under rice-field conditions.

    Science.gov (United States)

    Cattaneo, Roberta; Moraes, Bibiana Silveira; Loro, Vania Lucia; Pretto, Alexandra; Menezes, Charlene; Sartori, Gerson Meneghetti Sarzi; Clasen, Bárbara; de Avila, Luis Antonio; Marchesan, Enio; Zanella, Renato

    2012-01-01

    Field and laboratory experiments were performed to evaluate toxicological responses of Cyprinus carpio exposed to the commercial herbicide clomazone (500 mg l(-1)). Fish were exposed to 0.5 mg l(-1) of the formulated herbicide for 7, 30, and 90 days. Fish were exposed to clomazone in field conditions (7, 30, or 90 days trapped in submersed cages together with rice crops) and in laboratory conditions where the fish were placed in 45-l tanks with tap water only for 7 days. Fish exposed for 7, 30, or 90 days showed no alterations in acetylcholinesterase (AChE) activity under field conditions. Under laboratory conditions, decreased muscle AChE activity was observed only after 7 days of exposure. During the same evaluation period (7 days), oxidative stress parameters changed under both field and laboratory conditions; however, metabolic parameters were altered only under field conditions. Disorders in oxidative stress parameters and metabolism were evident in different tissues up to day 90 after treatment. These overall results show that AChE activity changed only under laboratory conditions. Oxidative stress, along with metabolic parameters, may be good indicators of herbicide contamination in C. carpio under rice-field conditions.

  15. Effect of a retention interval between pre-exposure and conditioning on latent inhibition in humans using a blink conditioning procedure.

    Science.gov (United States)

    De la Casa Rivas, Luis Gonzalo; Traverso Arcos, Luis Miguel; Márquez Zamora, Raúl

    2010-11-01

    Latent inhibition, retarded learning after pre-exposure to the to-be-conditioned stimulus, was examined using a blink conditioned procedure in humans. Experiment 1 showed that the procedure is suited to inducing the latent inhibition effect. In Experiment 2, the introduction of a 3-minute interval between pre-exposure and conditioning phases attenuated latent inhibition. These results contribute to identify the mechanisms involved in pre-exposure and subsequent conditioning of a stimulus, which is particularly important if we bear in mind that latent inhibition has been used repeatedly as an instrument to analyze the course of attentional processes in normal and pathological populations.

  16. Sex-based differences in brain alterations across chronic pain conditions.

    Science.gov (United States)

    Gupta, Arpana; Mayer, Emeran A; Fling, Connor; Labus, Jennifer S; Naliboff, Bruce D; Hong, Jui-Yang; Kilpatrick, Lisa A

    2017-01-02

    Common brain mechanisms are thought to play a significant role across a multitude of chronic pain syndromes. In addition, there is strong evidence for the existence of sex differences in the prevalence of chronic pain and in the neurobiology of pain. Thus, it is important to consider sex when developing general principals of pain neurobiology. The goal of the current Mini-Review is to evaluate what is known about sex-specific brain alterations across multiple chronic pain populations. A total of 15 sex difference and 143 single-sex articles were identified from among 412 chronic pain neuroimaging articles. Results from sex difference studies indicate more prominent primary sensorimotor structural and functional alterations in female chronic pain patients compared with male chronic pain patients: differences in the nature and degree of insula alterations, with greater insula reactivity in male patients; differences in the degree of anterior cingulate structural alterations; and differences in emotional-arousal reactivity. Qualitative comparisons of male-specific and female-specific studies appear to be consistent with the results from sex difference studies. Given these differences, mixed-sex studies of chronic pain risk creating biased data or missing important information and single-sex studies have limited generalizability. The advent of large-scale neuroimaging databases will likely aid in building a more comprehensive understanding of sex differences and commonalities in brain mechanisms underlying chronic pain. © 2016 Wiley Periodicals, Inc.

  17. A Strange Condition of Things: Alterity and Knowingness in Dickens' "David

    Science.gov (United States)

    Smith, Richard

    2013-01-01

    It is sometimes said that we are strangers to ourselves, bearers of internal alterity, as well as to each other. The profounder this strangeness then the greater the difficulty of giving any systematic account of it without paradox: of supposing that our obscurity to ourselves can readily be illuminated. To attempt such an account, in defiance of…

  18. Molecular alteration of marine dissolved organic matter under experimental hydrothermal conditions

    Science.gov (United States)

    Hawkes, Jeffrey A.; Hansen, Christian T.; Goldhammer, Tobias; Bach, Wolfgang; Dittmar, Thorsten

    2016-02-01

    Marine dissolved organic matter (DOM) is a large (660 Pg) pool of reduced carbon that is subject to thermal alteration in hydrothermal systems and sedimentary basins. In natural high-temperature hydrothermal systems, DOM is almost completely removed, but the mechanism and temperature dependence of this removal have not been studied to date. We investigated molecular-level changes to DOM that was solid-phase extracted (SPE-DOM) from the deep ocean of the North Pacific Ocean. This complex molecular mixture was experimentally exposed to temperatures between 100 and 380 °C over the course of two weeks in artificial seawater, and was then characterised on a molecular level via ultrahigh-resolution Fourier-transform ion cyclotron mass spectrometry (FT-ICR-MS). Almost 93% of SPE-DOM was removed by the treatment at 380 °C, and this removal was accompanied by a consistent pattern of SPE-DOM alteration across the temperatures studied. Higher molecular weight and more oxygen rich compounds were preferentially removed, suggesting that decarboxylation and dehydration of carboxylic acid and alcohol groups are the most rapid degradation mechanisms. Nitrogen containing compounds followed the same overall trends as those containing just C, H and O up to 300 °C. Above this temperature, the most highly altered samples contained very little of the original character of marine DOM, instead being mainly composed of very low intensity N- and S- containing molecules with a high H/C ratio (>1.5). Our results suggest that abiotic hydrothermal alteration of SPE-DOM may already occur at temperatures above 68 °C. Our experiments were conducted without a sedimentary or mineral phase, and demonstrate that profound molecular alteration and almost complete removal of marine SPE-DOM requires nothing more than heating in a seawater matrix.

  19. Prenatal Choline Availability Alters the Context Sensitivity of Pavlovian Conditioning in Adult Rats

    Science.gov (United States)

    Lamoureux, Jeffrey A.; Meck, Warren H.; Williams, Christina L.

    2008-01-01

    The effects of prenatal choline availability on Pavlovian conditioning were assessed in adult male rats (3-4 mo). Neither supplementation nor deprivation of prenatal choline affected the acquisition and extinction of simple Pavlovian conditioned excitation, or the acquisition and retardation of conditioned inhibition. However, prenatal choline…

  20. Prenatal Choline Availability Alters the Context Sensitivity of Pavlovian Conditioning in Adult Rats

    Science.gov (United States)

    Lamoureux, Jeffrey A.; Meck, Warren H.; Williams, Christina L.

    2008-01-01

    The effects of prenatal choline availability on Pavlovian conditioning were assessed in adult male rats (3-4 mo). Neither supplementation nor deprivation of prenatal choline affected the acquisition and extinction of simple Pavlovian conditioned excitation, or the acquisition and retardation of conditioned inhibition. However, prenatal choline…

  1. Widespread oxidized and hydrated amorphous silicates in CR chondrites matrices: Implications for alteration conditions and H2 degassing of asteroids

    Science.gov (United States)

    Le Guillou, Corentin; Changela, Hitesh G.; Brearley, Adrian J.

    2015-06-01

    The CR chondrites carry one of the most pristine records of the solar nebula materials that accreted to form planetesimals. They have experienced very variable degrees of aqueous alteration, ranging from incipient alteration in their matrices to the complete hydration of all of their components. In order to constrain their chemical alteration pathways and the conditions of alteration, we have investigated the mineralogy and Fe oxidation state of silicates in the matrices of 8 CR chondrites, from type 3 to type 1. Fe-L edge X-ray Absorption Near Edge Structure (XANES) was performed on matrix FIB sections using synchrotron-based scanning transmission X-ray microscopy (STXM). The Fe3+ / ∑ Fe ratio of submicron silicate particles was obtained and coordinated with TEM observations. In all the least altered CR chondrites (QUE 99177, EET 87770, EET 92042, LAP 02342, GRA 95229 and Renazzo), we find that the matrices consist of abundant submicron Fe-rich hydrated amorphous silicate grains, mixed with nanometer-sized phyllosilicates. The Fe3+ / ∑ Fe ratios of both amorphous and nanocrystalline regions are very high with values ranging from 68 to 78%. In the most altered samples (Al Rais and GRO 95577), fine-grained phyllosilicates also have a high Fe3+ / ∑ Fe ratio (around 70%), whereas the coarse, micrometer-sized phyllosilicates are less oxidized (down to 55%) and have a lower iron content. These observations suggest the following sequence: submicron Fe2+-amorphous silicate particles were the building blocks of CR matrices; after accretion they were quickly hydrated and oxidized, leading to a metastable, amorphous gel-like phase. Nucleation and growth of crystalline phyllosilicates was kinetically-limited in most type 3 and 2 CRs, but increased as alteration became more extensive in Al Rais and GRO 95577. The decreasing Fe3+ / ∑ Fe ratio is interpreted as a result of the transfer of Fe3+ from silicates to oxides during growth, while aqueous alteration progressed

  2. Postural control in response to altered sensory conditions in persons with dysvascular and traumatic transtibial amputation.

    Science.gov (United States)

    Jayakaran, Prasath; Johnson, Gillian M; Sullivan, S John

    2015-02-01

    To compare the postural control of persons with a dysvascular transtibial amputation and traumatic transtibial amputation with able-bodied adults with and without a dysvascular condition in altered sensory testing conditions. Cross-sectional study. University balance clinic. The study participants (N=35) included: participants with a dysvascular transtibial amputation (n=9), participants with a traumatic transtibial amputation (n=9), age-matched able-bodied adults without a dysvascular condition (n=9), and able-bodied adults with a dysvascular condition (n=8). Six Sensory Organization Test (SOT) conditions, which included standing with eyes open (condition 1) and closed (condition 2) on a static force platform with visual surround; standing with eyes open on a static force platform with movable visual surround (condition 3); standing with eyes open (condition 4) and closed (condition 5) on a movable force platform with static visual surround; and standing with eyes open on a movable force platform with movable visual surround (condition 6). Bilateral anteroposterior (AP) and mediolateral (ML) center of pressure variables, namely root mean square distance (RMSD) and mean velocity (mVel), for each of the 6 SOT conditions. The dysvascular transtibial amputation group demonstrated a higher AP RMSD (P≤.04) on the sound side than did the able-bodied adults without a dysvascular condition and the able-bodied adults with a dysvascular condition in SOT conditions 1 and 2, respectively. Both the dysvascular transtibial amputation group and the traumatic transtibial amputation group demonstrated a higher AP RMSD (P≤.002) than the able-bodied adults without a dysvascular condition in SOT conditions 3 and 4. The dysvascular transtibial amputation group showed higher AP mVel (P≤.002) on the sound side for SOT conditions 2 and 3, whereas both amputation groups showed higher AP mVel for SOT conditions 1 and 4 than the able-bodied adults with and without a dysvascular

  3. Short-term total sleep deprivation alters delay-conditioned memory in the rat.

    Science.gov (United States)

    Tripathi, Shweta; Jha, Sushil K

    2016-06-01

    Short-term sleep deprivation soon after training may impair memory consolidation. Also, a particular sleep stage or its components increase after learning some tasks, such as negative and positive reinforcement tasks, avoidance tasks, and spatial learning tasks, and so forth. It suggests that discrete memory types may require specific sleep stage or its components for their optimal processing. The classical conditioning paradigms are widely used to study learning and memory but the role of sleep in a complex conditioned learning is unclear. Here, we have investigated the effects of short-term sleep deprivation on the consolidation of delay-conditioned memory and the changes in sleep architecture after conditioning. Rats were trained for the delay-conditioned task (for conditioning, house-light [conditioned stimulus] was paired with fruit juice [unconditioned stimulus]). Animals were divided into 3 groups: (a) sleep deprived (SD); (b) nonsleep deprived (NSD); and (c) stress control (SC) groups. Two-way ANOVA revealed a significant interaction between groups and days (training and testing) during the conditioned stimulus-unconditioned stimulus presentation. Further, Tukey post hoc comparison revealed that the NSD and SC animals exhibited significant increase in performances during testing. The SD animals, however, performed significantly less during testing. Further, we observed that wakefulness and NREM sleep did not change after training and testing. Interestingly, REM sleep increased significantly on both days compared to baseline more specifically during the initial 4-hr time window after conditioning. Our results suggest that the consolidation of delay-conditioned memory is sleep-dependent and requires augmented REM sleep during an explicit time window soon after training. (PsycINFO Database Record

  4. Zonal rate model for stacked membrane chromatography part II: characterizing ion-exchange membrane chromatography under protein retention conditions.

    Science.gov (United States)

    Francis, Patrick; von Lieres, Eric; Haynes, Charles

    2012-03-01

    The Zonal Rate Model (ZRM) has previously been shown to accurately account for contributions to elution band broadening, including external flow nonidealities and radial concentration gradients, in ion-exchange membrane (IEXM) chromatography systems operated under nonbinding conditions. Here, we extend the ZRM to analyze and model the behavior of retained proteins by introducing terms for intra-column mass transfer resistances and intrinsic binding kinetics. Breakthrough curve (BTC) data from a scaled-down anion-exchange membrane chromatography module using ovalbumin as a model protein were collected at flow rates ranging from 1.5 to 20 mL min(-1). Through its careful accounting of transport nonidealities within and external to the membrane stack, the ZRM is shown to provide a useful framework for characterizing putative protein binding mechanisms and models, for predicting BTCs and complex elution behavior, including the common observation that the dynamic binding capacity can increase with linear velocity in IEXM systems, and for simulating and scaling separations using IEXM chromatography. Global fitting of model parameters is used to evaluate the performance of the Langmuir, bi-Langmuir, steric mass action (SMA), and spreading-type protein binding models in either correlating or fundamentally describing BTC data. When combined with the ZRM, the bi-Langmuir, and SMA models match the chromatography data, but require physically unrealistic regressed model parameters to do so. In contrast, for this system a spreading-type model is shown to accurately predict column performance while also providing a realistic fundamental explanation for observed trends, including an observed increase in dynamic binding capacity with flow rate.

  5. The tomato res mutant which accumulates JA in roots in non-stressed conditions restores cell structure alterations under salinity.

    Science.gov (United States)

    Garcia-Abellan, José O; Fernandez-Garcia, Nieves; Lopez-Berenguer, Carmen; Egea, Isabel; Flores, Francisco B; Angosto, Trinidad; Capel, Juan; Lozano, Rafael; Pineda, Benito; Moreno, Vicente; Olmos, Enrique; Bolarin, Maria C

    2015-11-01

    Jasmonic acid (JA) regulates a wide spectrum of plant biological processes, from plant development to stress defense responses. The role of JA in plant response to salt stress is scarcely known, and even less known is the specific response in root, the main plant organ responsible for ionic uptake and transport to the shoot. Here we report the characterization of the first tomato (Solanum lycopersicum) mutant, named res (restored cell structure by salinity), that accumulates JA in roots prior to exposure to stress. The res tomato mutant presented remarkable growth inhibition and displayed important morphological alterations and cellular disorganization in roots and leaves under control conditions, while these alterations disappeared when the res mutant plants were grown under salt stress. Reciprocal grafting between res and wild type (WT) (tomato cv. Moneymaker) indicated that the main organ responsible for the development of alterations was the root. The JA-signaling pathway is activated in res roots prior to stress, with transcripts levels being even higher in control condition than in salinity. Future studies on this mutant will provide significant advances in the knowledge of JA role in root in salt-stress tolerance response, as well as in the energy trade-off between plant growth and response to stress.

  6. Herbivore body condition response in altered environments: mule deer and habitat management.

    Directory of Open Access Journals (Sweden)

    Eric J Bergman

    Full Text Available The relationships between habitat, body condition, life history characteristics, and fitness components of ungulates are interwoven and of interest to researchers as they strive to understand the impacts of a changing environment. With the increased availability of portable ultrasound machines and the refinement of hormonal assays, assessment of ungulate body condition has become an accessible monitoring strategy. We employed body condition scoring, estimation of % ingesta-free body fat (%IFBF, assessment of free thyroid hormones (FT4 and FT3, and assessment of pregnancy, as metrics to determine if landscape-level habitat treatments affected body condition of adult (≥ 1.5 years old female mule deer (Odocoileus hemionus. All body condition related metrics were measured on 2 neighboring study areas--a reference area that had received no habitat treatments and a treatment study area that had received mechanical removal of pinyon pine (Pinyus edulis--Utah juniper (Juniperus osteosperma forest, chemical control of weeds, and reseeding with preferred mule deer browse species. A consistent trend of higher %IFBF was observed in the treatment study area [Formula: see text] than in the reference study area [Formula: see text], although variation of estimates was larger than hypothesized. A similar pattern was observed with higher thyroid hormones concentrations being observed in the treatment study area, but large amounts of variation within concentration estimates were also observed. The consistent pattern of higher body condition related estimates in our treatment study area provides evidence that large mammalian species are sensitive to landscape change, although variation within estimates underlie the challenge in detecting population level impacts stemming from environmental change.

  7. Clinically Relevant Growth Conditions Alter Acinetobacter baumannii Antibiotic Susceptibility and Promote Identification of Novel Antibacterial Agents.

    Directory of Open Access Journals (Sweden)

    Jennifer M Colquhoun

    Full Text Available Biological processes that govern bacterial proliferation and survival in the host-environment(s are likely to be vastly different from those that are required for viability in nutrient-rich laboratory media. Consequently, growth-based antimicrobial screens performed in conditions modeling aspects of bacterial disease states have the potential to identify new classes of antimicrobials that would be missed by screens performed in conventional laboratory media. Accordingly, we performed screens of the Selleck library of 853 FDA approved drugs for agents that exhibit antimicrobial activity toward the Gram-negative bacterial pathogen Acinetobacter baumannii during growth in human serum, lung surfactant, and/or the organism in the biofilm state and compared those results to that of conventional laboratory medium. Results revealed that a total of 90 compounds representing 73 antibiotics and 17 agents that were developed for alternative therapeutic indications displayed antimicrobial properties toward the test strain in at least one screening condition. Of the active library antibiotics only four agents, rifampin, rifaximin, ciprofloxacin and tetracycline, exhibited antimicrobial activity toward the organism during all screening conditions, whereas the remainder were inactive in ≥ 1 condition; 56 antibiotics were inactive during serum growth, 25 and 38 were inactive toward lung surfactant grown and biofilm-associated cells, respectively, suggesting that subsets of antibiotics may outperform others in differing infection settings. Moreover, 9 antibiotics that are predominantly used for the treatment Gram-positive pathogens and 10 non-antibiotics lacked detectable antimicrobial activity toward A. baumannii grown in conventional medium but were active during ≥ 1 alternative growth condition(s. Such agents may represent promising anti-Acinetobacter agents that would have likely been overlooked by antimicrobial whole cell screening assays performed in

  8. A distinct role for interleukin-6 as a major mediator of cellular adjustment to an altered culture condition.

    Science.gov (United States)

    Son, Hwa-Kyung; Park, Iha; Kim, Jue Young; Kim, Do Kyeong; Illeperuma, Rasika P; Bae, Jung Yoon; Lee, Doo Young; Oh, Eun-Sang; Jung, Da-Woon; Williams, Darren R; Kim, Jin

    2015-11-01

    Tissue microenvironment adjusts biological properties of different cells by modulating signaling pathways and cell to cell interactions. This study showed that epithelial-mesenchymal transition (EMT)/ mesenchymal-epithelial transition (MET) can be modulated by altering culture conditions. HPV E6/E7-transfected immortalized oral keratinocytes (IHOK) cultured in different media displayed reversible EMT/MET accompanied by changes in cell phenotype, proliferation, gene expression at transcriptional, and translational level, and migratory and invasive activities. Cholera toxin, a major supplement to culture medium, was responsible for inducing the morphological and biological changes of IHOK. Cholera toxin per se induced EMT by triggering the secretion of interleukin 6 (IL-6) from IHOK. We found IL-6 to be a central molecule that modulates the reversibility of EMT based not only on the mRNA level but also on the level of secretion. Taken together, our results demonstrate that IL-6, a cytokine whose transcription is activated by alterations in culture conditions, is a key molecule for regulating reversible EMT/MET. This study will contribute to understand one way of cellular adjustment for surviving in unfamiliar conditions.

  9. Altering the growth conditions of Gluconacetobacter xylinus to maximize the yield of bacterial cellulose.

    Science.gov (United States)

    Ruka, Dianne R; Simon, George P; Dean, Katherine M

    2012-06-20

    An extensive matrix of different growth conditions including media, incubation time, inoculum volume, surface area and media volume were investigated in order to maximize the yield of bacterial cellulose produced by Gluconacetobacter xylinus, which will be used as reinforcement material to produce fully biodegradable composites. Crystallinity was shown to be controllable depending on the media and conditions employed. Samples with significant difference in crystallinity in a range from 50% to 95% were produced. Through experimental design, the yield of cellulose was maximized; primarily this involved reactor surface area design, optimized media and the use of mannitol being the highest cellulose-producing carbon source. Increasing the volume of the media did achieve a higher cellulose yield, however this increase was not found to be cost or time effective.

  10. Evaluation of Geochemical Fracture Conductivity Alterations in Shale under Laboratory Conditions

    Science.gov (United States)

    Radonjic, M.; Olabode, A.

    2015-12-01

    In large scale subsurface injection of carbondioxide as obtainable in carbon sequestration programs and in environmentally friendly hydraulic fracturing processes (using supercritical CO2), rock-fluid interaction can affect reservoir and seal rocks properties which are essential in monitoring the progress of these operations. The mineralogical components of sedimentary rocks are geochemically active particularly under enormous earth stresses. While geomechanical properties such as rock stiffness, Poisson's ratio and fracture geometry largely govern fluid flow characteristics in deep fractured formations, the effect of mineralization can lead to flow impedance in the presence of favorable geochemical and thermodynamic conditions. Experimental works which employed the use of analytical tools such as ICP-OES, XRD, SEM/EDS, TOC and BET techniques in investigating diagenetic and micro-structural properties of crushed shale caprock/CO2-brine system concluded that net precipitation reaction processes can affect the distribution of petrophysical nanopores in the shale as a result of rock-fluid interactions. Simulation results previously reported, suggest that influx-induced mineral dissolution/precipitation reactions within clay-based sedimentary rocks can continuously close micro-fracture networks, though injection pressure and effective-stress transformation first rapidly expand these fractures. This experimental modelling research investigated the impact of in-situ geochemical precipitation on conductivity of fractures under geomechanical stress conditions. Conductivity is measured as differential-pressure drop equivalence, using a pressure pulse-decay liquid permeametry/core flooding system, as geochemically saturated-fluid is transported through composite cores with embedded micro-tubings that mimic fractures. The reactive fluid is generated from crushed shale rocks of known mineralogical composition when flooded with aqueous CO2 at elevated temperature and pressure

  11. Optimization of phytase production from escherichia coli by altering solids-state fermentation conditions

    OpenAIRE

    McKinney, K.; Combs, J.; Becker, P.; Humphries, A.; K. Filer; Vriesekoop, F.

    2015-01-01

    Cultivation of Escherichia coli on wheat-bran substrate under various Solid-State Fermentation (SSF) conditions was evaluated for phytase yield along with the enzyme activity profile as a potential, low-cost alternative to submerged-liquid fermentation. The maximum phytase activity achieved by E. coli was 350 ± 50 SPU of phytase activity per gram of bran, incubated for 96 h with a substrate bed moisture content of 70% (w/v) at 37 °C with a relative air humidity of 90%, and supplemented with 1...

  12. Verbal instructions targeting valence alter negative conditional stimulus evaluations (but do not affect reinstatement rates).

    Science.gov (United States)

    Luck, Camilla C; Lipp, Ottmar V

    2017-01-31

    Negative conditional stimulus (CS) valence acquired during fear conditioning may enhance fear relapse and is difficult to remove as it extinguishes slowly and does not respond to the instruction that unconditional stimulus (US) presentations will cease. We examined whether instructions targeting CS valence would be more effective. In Experiment 1, an image of one person (CS+) was paired with an aversive US, while another (CS-) was presented alone. After acquisition, participants were given positive information about the CS+ poser and negative information about the CS- poser. Instructions reversed the pattern of differential CS valence present during acquisition and eliminated differential electrodermal responding. In Experiment 2, we compared positive and negative CS revaluation by providing positive/negative information about the CS+ and neutral information about CS-. After positive revaluation, differential valence was removed and differential electrodermal responding remained intact. After negative revaluation, differential valence was strengthened and differential electrodermal responding was eliminated. Unexpectedly, the instructions did not affect the reinstatement of differential electrodermal responding.

  13. Sleep alterations in mammals: did aquatic conditions inhibit rapid eye movement sleep?

    Science.gov (United States)

    Madan, Vibha; Jha, Sushil K

    2012-12-01

    Sleep has been studied widely in mammals and to some extent in other vertebrates. Higher vertebrates such as birds and mammals have evolved an inimitable rapid eye movement (REM) sleep state. During REM sleep, postural muscles become atonic and the temperature regulating machinery remains suspended. Although REM sleep is present in almost all the terrestrial mammals, the aquatic mammals have either radically reduced or completely eliminated REM sleep. Further, we found a significant negative correlation between REM sleep and the adaptation of the organism to live on land or in water. The amount of REM sleep is highest in terrestrial mammals, significantly reduced in semi-aquatic mammals and completely absent or negligible in aquatic mammals. The aquatic mammals are obligate swimmers and have to surface at regular intervals for air. Also, these animals live in thermally challenging environments, where the conductive heat loss is approximately ~90 times greater than air. Therefore, they have to be moving most of the time. As an adaptation, they have evolved unihemispheric sleep, during which they can rove as well as rest. A condition that immobilizes muscle activity and suspends the thermoregulatory machinery, as happens during REM sleep, is not suitable for these animals. It is possible that, in accord with Darwin's theory, aquatic mammals might have abolished REM sleep with time. In this review, we discuss the possibility of the intrinsic role of aquatic conditions in the elimination of REM sleep in the aquatic mammals.

  14. Intravenous Prenatal Nicotine Exposure Alters METH-Induced Hyperactivity, Conditioned Hyperactivity, and BDNF in Adult Rat Offspring.

    Science.gov (United States)

    Lacy, Ryan T; Brown, Russell W; Morgan, Amanda J; Mactutus, Charles F; Harrod, Steven B

    2016-01-01

    In the USA, approximately 15% of women smoke tobacco cigarettes during pregnancy. In utero tobacco smoke exposure produces somatic growth deficits like intrauterine growth restriction and low birth weight in offspring, but it can also negatively influence neurodevelopmental outcomes in later stages of life, such as an increased incidence of obesity and drug abuse. Animal models demonstrate that prenatal nicotine (PN) alters the development of the mesocorticolimbic system, which is important for organizing goal-directed behavior. In the present study, we determined whether intravenous (IV) PN altered the initiation and/or expression of methamphetamine (METH)-induced locomotor sensitization as a measure of mesocorticolimbic function in adult rat offspring. We also determined whether PN and/or METH exposure altered protein levels of BDNF (brain-derived neurotrophic factor) in the nucleus accumbens, the dorsal striatum, and the prefrontal cortex of adult offspring. BDNF was of interest because of its role in the development and maintenance of the mesocorticolimbic pathway and its ability to modulate neural processes that contribute to drug abuse, such as sensitization of the dopamine system. Dams were injected with IV nicotine (0.05 mg/kg/injection) or saline, 3×/day on gestational days 8-21. Testing was conducted when offspring reached adulthood (around postnatal day 90). Following 3 once daily habituation sessions the animals received a saline injection and baseline locomotor activity was measured. PN and prenatal saline (PS)-exposed offspring then received 10 once daily injections of METH (0.3 mg/kg) to induce locomotor sensitization. The animals received a METH injection (0.3 mg/kg) to assess the expression of sensitization following a 14-day period of no injections. A day later, all animals were injected with saline and conditioned hyperactivity was assessed. Brain tissue was harvested 24 h later. PN animals habituated more slowly to the activity chambers

  15. Adrenergic drugs modify the level of noradrenaline in the insular cortex and alter extinction of conditioned taste aversion in rats.

    Science.gov (United States)

    Fresquet, Nadine; Angst, Marie-Josée; Schleef, Carmen; Gobaille, Serge; Sandner, Guy

    2007-03-12

    We compared the effect of conditioned taste aversion in rats by measuring the amount of sucrose that they drunk after conditioning, which differed according to whether rats had drunk the sucrose freely (SD: self drinking) during the conditioning session, or had been forced to drink it (IO: intra-oral administration through a chronically implanted cannula). The SD procedure delayed the extinction of conditioned taste aversion. Enhanced arousal, alertness, awareness or attention in the SD condition may have strengthened the memory of the taste. Brain noradrenergic networks are involved in such processes. We administered two noradrenergic drugs that produce opposite effects on noradrenaline release in the brain, methoxy-idazoxan, RX821002 (1mg/kg, i.p.), and guanfacine (0.12mg/kg, i.p.). We evaluated their effect (i) on the level of noradrenaline in the gustatory cortex using microdialysis, (ii) on glycaemia that is an essential factor of taste learning and (iii) on the comparative SD versus IO conditioned taste aversion protocol mentioned above. Injecting RX821001 increased the level of noradrenaline in the gustatory cortex up to two-fold of the baseline. This effect lasted 1h. The same dose of RX821002 did not elicit any alteration of glycaemia. It enhanced extinction of conditioned taste aversion in the SD group of rats. Injecting 0.12mg/kg of guanfacine produced the opposite effect. The noradrenaline level of the gustatory cortex decreased, but only down to 20% of the baseline. This decrease lasted 2h. Guanfacine increased glycaemia. Extinction of conditioned taste aversion was only marginally decreased by guanfacine in the SD group of rats. These results fit with Aston-Jones' point of view that the role of the noradrenergic coeruleo-cortical system may be to enhance arousal, alertness, awareness or attention to an event by a transient increase of cortical noradrenaline.

  16. Alteration of MX-80 by hydrothermal treatment under high salt content conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, R. [Geodevelopment AB, Lund (Sweden); Kasbohm, J. [Greifswald Univ. (Germany). Geological Dep.

    2002-02-01

    If brammalit, i.e. sodium illite, is formed from smectite in Na-rich salt water at high temperature such conversion can also take place in the buffer clay that surrounds the canisters in a KBS-3 repository. The present study comprised two laboratory test series with MX-80 clay, one with compacted clay powder with a dry density of 1200 to 1300 kg/m{sup 3} and saturation with 10% and 20% NaCl solutions followed by heating to 110 deg C under closed conditions for 30 days. In the second series air-dry compacted clay powder in a cell was heated at 110 deg C for the same period of time and connected to vessels with 10% and 20% NaCl solutions. The first series represents the conditions in the buffer clay after saturation with Na-rich salt water while the second one corresponds to the conditions in the course of saturation with such water. All laboratory tests were made after short-term percolation with distilled water for making sure that the hydro-thermally treated samples were fully fluid-saturated. The results from the physical testing showed that the hydraulic conductivity and swelling pressure of the hydrothermally treated clay samples were on the same order of magnitude as for untreated clay. Comparison with illitic clays shows that the latter are at least a hundred times more permeable than the hydrothermally treated salt clays in the present study, which hence indicates that conversion to illite was insignificant. This is obvious also from the fact that while illitic clays have very low swelling pressures the hydrothermally treated clays exhibited swelling pressures on the same order of magnitude as untreated MX-80. XRD analysis showed a clear difference in mineral constitution between the two test series. Thus, while no significant change from the typical mineralogy of untreated MX-80 was found for hydrothermal treatment of clay saturated with 10 and 20% NaCl solution, except for some very slight neoformation of illite-smectite mixed layers or irreversible

  17. Ultrastructural alteration of the cell surface of Staphylococcus aureus cultured in a different salt condition

    Directory of Open Access Journals (Sweden)

    Kanemasa,Yasuhiro

    1974-10-01

    Full Text Available Staphylococcus aureus growing in a normal NaGI medium has a specific NaGI tolerance property to grow in the medium contain. ing NaGl in as high a concentration as over 10%. In our comparative study of the cells proliferating in the normal NaGI medium and 10% NaGl medium, we have observed the following differences aside from the changes of lipid composition in the cytoplasmic membrane previously reported. 1. S. aureus grown in high NaGl medium undergoes changes as to increase its size and reduce its surface area. 2. The thickness and weight of cell wall are increased to about 1. 7 times and 1. 32 times, respectively. 3. The protoplast prepared from S. aureus growing in the high NaGI medium shows a weaker resistance to hypotonic condition than that from normal cell.

  18. Alteration of MX-80 by hydrothermal treatment under high salt content conditions

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, R. [Geodevelopment AB, Lund (Sweden); Kasbohm, J. [Greifswald Univ. (Germany). Geological Dep.

    2002-02-01

    If brammalit, i.e. sodium illite, is formed from smectite in Na-rich salt water at high temperature such conversion can also take place in the buffer clay that surrounds the canisters in a KBS-3 repository. The present study comprised two laboratory test series with MX-80 clay, one with compacted clay powder with a dry density of 1200 to 1300 kg/m{sup 3} and saturation with 10% and 20% NaCl solutions followed by heating to 110 deg C under closed conditions for 30 days. In the second series air-dry compacted clay powder in a cell was heated at 110 deg C for the same period of time and connected to vessels with 10% and 20% NaCl solutions. The first series represents the conditions in the buffer clay after saturation with Na-rich salt water while the second one corresponds to the conditions in the course of saturation with such water. All laboratory tests were made after short-term percolation with distilled water for making sure that the hydro-thermally treated samples were fully fluid-saturated. The results from the physical testing showed that the hydraulic conductivity and swelling pressure of the hydrothermally treated clay samples were on the same order of magnitude as for untreated clay. Comparison with illitic clays shows that the latter are at least a hundred times more permeable than the hydrothermally treated salt clays in the present study, which hence indicates that conversion to illite was insignificant. This is obvious also from the fact that while illitic clays have very low swelling pressures the hydrothermally treated clays exhibited swelling pressures on the same order of magnitude as untreated MX-80. XRD analysis showed a clear difference in mineral constitution between the two test series. Thus, while no significant change from the typical mineralogy of untreated MX-80 was found for hydrothermal treatment of clay saturated with 10 and 20% NaCl solution, except for some very slight neoformation of illite-smectite mixed layers or irreversible

  19. Sleep alterations in mammals: Did aquatic conditions inhibit rapid eye movement sleep?

    Institute of Scientific and Technical Information of China (English)

    Vibha Madan; Sushil K.Jha

    2012-01-01

    Sleep has been studied widely in mammals and to some extent in other vertebrates.Higher vertebrates such as birds and mammals have evolved an inimitable rapid eye movement (REM) sleep state.During REM sleep,postural muscles become atonic and the temperature regulating machinery remains suspended.Although REM sleep is present in almost all the terrestrial mammals,the aquatic mammals have either radically reduced or completely eliminated REM sleep.Further,we found a significant negative correlation between REM sleep and the adaptation of the organism to live on land or in water.The amount of REM sleep is highest in terrestrial mammals,significantly reduced in semi-aquatic mammals and completely absent or negligible in aquatic mammals.The aquatic mammals are obligate swimmers and have to surface at regular intervals for air.Also,these animals live in thermally challenging environments,where the conductive heat loss is approximately ~90 times greater than air.Therefore,they have to be moving most of the time.As an adaptation,they have evolved unihemispheric sleep,during which they can rove as well as rest.A condition that immobilizes muscle activity and suspends the thermoregulatory machinery,as happens during REM sleep,is not suitable for these animals.It is possible that,in accord with Darwin's theory,aquatic mammals might have abolished REM sleep with time.In this review,we discuss the possibility of the intrinsic role of aquatic conditions in the elimination of REM sleep in the aquatic mammals.

  20. Identification of alterations in the Jacobian of biochemical reaction networks from steady state covariance data at two conditions.

    Science.gov (United States)

    Kügler, Philipp; Yang, Wei

    2014-06-01

    Model building of biochemical reaction networks typically involves experiments in which changes in the behavior due to natural or experimental perturbations are observed. Computational models of reaction networks are also used in a systems biology approach to study how transitions from a healthy to a diseased state result from changes in genetic or environmental conditions. In this paper we consider the nonlinear inverse problem of inferring information about the Jacobian of a Langevin type network model from covariance data of steady state concentrations associated to two different experimental conditions. Under idealized assumptions on the Langevin fluctuation matrices we prove that relative alterations in the network Jacobian can be uniquely identified when comparing the two data sets. Based on this result and the premise that alteration is locally confined to separable parts due to network modularity we suggest a computational approach using hybrid stochastic-deterministic optimization for the detection of perturbations in the network Jacobian using the sparsity promoting effect of [Formula: see text]-penalization. Our approach is illustrated by means of published metabolomic and signaling reaction networks.

  1. Frontal white matter alterations in short-term medicated panic disorder patients without comorbid conditions: a diffusion tensor imaging study.

    Directory of Open Access Journals (Sweden)

    Borah Kim

    Full Text Available The frontal cortex might play an important role in the fear network, and white matter (WM integrity could be related to the pathophysiology of panic disorder (PD. A few studies have investigated alterations of WM integrity in PD. The aim of this study was to determine frontal WM integrity differences between patients with PD without comorbid conditions and healthy control (HC subjects by using diffusion tensor imaging. Thirty-six patients with PD who had used medication within 1 week and 27 age- and sex-matched HC subjects participated in this study. Structural brain magnetic resonance imaging was performed on all participants. Panic Disorder Severity Scale and Beck Anxiety Inventory (BAI scores were assessed. Tract-based spatial statistics (TBSS was used for image analysis. TBSS analysis showed decreased fractional anisotropy (FA in frontal WM and WM around the frontal lobe, including the corpus callosum of both hemispheres, in patients with PD compared to HC subjects. Moreover, voxel-wise correlation analysis revealed that the BAI scores for patients with PD were positively correlated with their FA values for regions showing group differences in the FA of frontal WM of both hemispheres. Altered integrity in frontal WM of patients with PD without comorbid conditions might represent the structural pathophysiology in these patients, and these changes could be related to clinical symptoms of PD.

  2. Cultivation conditions and selenium fertilization alter the phenolic profile, glucosinolate, and sulforaphane content of broccoli.

    Science.gov (United States)

    Robbins, Rebecca J; Keck, Anna-Sigrid; Banuelos, Gary; Finley, John W

    2005-01-01

    Broccoli is a food often consumed for its potential health-promoting properties. The health benefits of broccoli are partly associated with secondary plant compounds that have bioactivity; glucosinolates and phenolic acids are two of the most abundant and important in broccoli. In an effort to determine how variety, stress, and production conditions affect the production of these bioactive components broccoli was grown in the greenhouse with and without selenium (Se) fertilization, and in the field under conventional or organic farming procedures and with or without water stress. High-performance liquid chromatography/mass spectrometry was used to separate and identify 12 primary phenolic compounds. Variety had a major effect: There was a preponderance of flavonoids in the Majestic variety, but hydroxycinnamic esters were relatively more abundant in the Legacy variety. Organic farming and water stress decreased the overall production of phenolics. Se fertilization increased glucosinolates in general, and sulforaphane in particular, up to a point; above that Se fertilization decreased glucosinolate production. Organic farming and water stress also decreased glucosinolate production. These data show environmental and genetic variation in phenolics and glucosinolates in broccoli, and warn that not all broccoli may contain all health-promoting bioactive components. They further show that selection for one bioactive component (Se) may decrease the content of other bioactive components such as phenolics and glucosinolates.

  3. Ablation of mouse adult neurogenesis alters olfactory bulb structure and olfactory fear conditioning

    Directory of Open Access Journals (Sweden)

    Matthew Valley

    2009-11-01

    Full Text Available Adult neurogenesis replenishes olfactory bulb (OB interneurons throughout the life of most mammals, yet during this constant fl ux it remains unclear how the OB maintains a constant structure and function. In the mouse OB, we investigated the dynamics of turnover and its impact on olfactory function by ablating adult neurogenesis with an x-ray lesion to the subventricular zone (SVZ. Regardless of the magnitude of the lesion to the SVZ, we found no change in the survival of young adult born granule cells (GCs born after the lesion, and a gradual decrease in the population of GCs born before the lesion. After a lesion producing a 96% reduction of incoming adult born GCs to the OB, we found a diminished behavioral fear response to conditioned odor cues but not to audio cues. Interestingly, despite this behavioral defi cit and gradual anatomical changes, we found no electrophysiological changes in the GC population assayed in vivo through dendro-dendritic synaptic plasticity and odor-evoked local fi eld potential oscillations. These data indicate that turnover in the granule cell layer is generally decoupled from the rate of adult neurogenesis, and that OB adult neurogenesis plays a role in a wide behavioral system extending beyond the OB.

  4. Effects of various storage conditions and alterations of antioxidant contents on chromatic aberration of hydroquinone ointment.

    Science.gov (United States)

    Matsubayashi, Teruhisa; Sakaeda, Toshiyuki; Kita, Tomoko; Nakamura, Tsutomu; Kakumoto, Mikio; Funasaka, Yoko; Ichihashi, Masamitsu; Fujita, Takuya; Kamiyama, Fumio; Yamamoto, Akira; Nordlund, James J; Kaneko, Masafumi; Iida, Akira; Okumura, Katsuhiko

    2003-01-01

    Ointments of the skin depigmentation agent hydroquinone (HQ) have been prepared by extemporaneous nonsterile compounding in our hospital. The HQ ointments were highly effective in the treatment of various types of skin pigmentations; however, various problems have emerged including chromatic aberration of the ointments, a relatively large variability of efficacy, and mild side effects. Chromatic aberration is expected to induce non-compliance, and this may be the reason for the relatively large variability in efficacy. In this paper, the effects of various storage conditions on the chromatic aberration and HQ content of HQ ointments were evaluated, and it was suggested that the chromatic aberration was accelerated by exposure to high temperature, air and light, although these had no effect on the HQ content. In addition, various types of HQ ointments were prepared to find a formulation to minimize chromatic aberration, and it was found that the concentrations of antioxidants, Na(2)SO(3) and L(+)-ascorbic acid (AsA), seemed to be too high, and that the protective effect of AsA on chromatic aberration was mainly due to its acidifying effect.

  5. Alteration of chaperonin60 and pancreatic enzyme in pancreatic acinar cell under pathological condition

    Institute of Scientific and Technical Information of China (English)

    Yong-Yu Li; Moise Bendayan

    2005-01-01

    AIM: To investigate the changes of chaperonin60 (Cpn60)and pancreatic enzymes in pancreatic acinar cells, and to explore their roles in the development of experimental diabetes and acute pancreatitis (AP).METHODS: Two different pathological models were replicated in Sprague-Dawley rats: streptozotocininduced diabetes and sodium deoxycholate-induced AP. The contents of Cpn60 and pancreatic enzymes in different compartments of the acinar cells were measured by quantitative immunocytochemistry.RESULTS: The levels of Cpn60 significantly increased in diabetes, but decreased in AP, especially in the zymogen granules of the pancreatic acinar cells. The elevation of Cpn60 was accompanied with the increased levels of pancreatic lipase and chymotrypsinogen in diabetes.However, a decreased Cpn60 level was accompanied by high levels of lipase and chymotrypsinogen in AP.The amylase level was markedly reduced in both the pathological conditions.CONCLUSION: The equilibrium between Cpn60 and pancreatic enzymes in the acinar cells breaks in AP, and Cpn60 content decreases, suggesting an insufficient chaperone capacity. This may promote the aggregation and autoactivation of the premature enzymes in the pancreatic acinar cells and play roles in the development of AP.

  6. Foraging behavior under starvation conditions is altered via photosynthesis by the marine gastropod, Elysia clarki.

    Directory of Open Access Journals (Sweden)

    Michael L Middlebrooks

    Full Text Available It has been well documented that nutritional state can influence the foraging behavior of animals. However, photosynthetic animals, those capable of both heterotrophy and symbiotic photosynthesis, may have a delayed behavioral response due to their ability to photosynthesize. To test this hypothesis we subjected groups of the kleptoplastic sea slug, Elysia clarki, to a gradient of starvation treatments of 4, 8, and 12 weeks plus a satiated control. Compared to the control group, slugs starved 8 and 12 weeks displayed a significant increase in the proportion of slugs feeding and a significant decrease in photosynthetic capability, as measured in maximum quantum yield and [chl a]. The 4 week group, however, showed no significant difference in feeding behavior or in the metrics of photosynthesis compared to the control. This suggests that photosynthesis in E. clarki, thought to be linked to horizontally-transferred algal genes, delays a behavioral response to starvation. This is the first demonstration of a link between photosynthetic capability in an animal and a modification of foraging behavior under conditions of starvation.

  7. Perturbation of the Secondary Structure of the Scrapie Prion Protein Under Conditions that Alter Infectivity

    Science.gov (United States)

    Gasset, Maria; Baldwin, Michael A.; Fletterick, Robert J.; Prusiner, Stanley B.

    1993-01-01

    Limited proteolysis of the scrapie prion protein (PrPSc) generates PrP 27-30, which polymerizes into amyloid. By attenuated total reflection-Fourier transform infrared spectroscopy, PrP 27-30 polymers contained 54% β-sheet, 25% α-helix, 10% turns, and 11% random coil; dispersion into detergent-lipid-protein-complexes preserved infectivity and secondary structure. Almost 60% of the β-sheet was low-frequency infrared-absorbing, reflecting intermolecular aggregation. Decreased low-frequency β-sheet and increased turn content were found after SDS/PAGE, which disassembled the amyloid polymers, denatured PrP 27-30, and diminished scrapie infectivity. Acid-induced transitions were reversible, whereas alkali produced an irreversible transition centered at pH 10 under conditions that diminished infectivity. Whether PrPSc synthesis involves a transition in the secondary structure of one or more domains of the cellular prion protein from α-helical, random coil, or turn into β-sheet remains to be established.

  8. Plant cell death and cellular alterations induced by ozone: Key studies in Mediterranean conditions

    Energy Technology Data Exchange (ETDEWEB)

    Faoro, Franco, E-mail: franco.faoro@unimi.i [Istituto di Patologia Vegetale, Universita di Milano and CNR, Istituto di Virologia Vegetale, U.O.T di Milano, Via Celoria 2, 20133 Milan (Italy); Iriti, Marcello [Istituto di Patologia Vegetale, Universita di Milano and CNR, Istituto di Virologia Vegetale, U.O.T di Milano, Via Celoria 2, 20133 Milan (Italy)

    2009-05-15

    An account of histo-cytological and ultrastructural studies on ozone effect on crop and forest species in Italy is given, with emphasis on induced cell death and the underlying mechanisms. Cell death phenomena possibly due to ambient O{sub 3} were recorded in crop and forest species. In contrast, visible O{sub 3} effects on Mediterranean vegetation are often unclear. Microscopy is thus suggested as an effective tool to validate and evaluate O{sub 3} injury to Mediterranean vegetation. A DAB-Evans blue staining was proposed to validate O{sub 3} symptoms at the microscopic level and for a pre-visual diagnosis of O{sub 3} injury. The method has been positively tested in some of the most important crop species, such as wheat, tomato, bean and onion and, with some restriction, in forest species, and it also allows one to gain some very useful insights into the mechanisms at the base of O{sub 3} sensitivity or tolerance. - Ozone-induced cell death is a frequent phenomenon in Mediterranean conditions, not only in the most sensitive crops but also in forest species.

  9. Warmer and drier conditions and nitrogen fertilizer application altered methanotroph abundance and methane emissions in a vegetable soil.

    Science.gov (United States)

    Ran, Yu; Xie, Jianli; Xu, Xiaoya; Li, Yong; Liu, Yapeng; Zhang, Qichun; Li, Zheng; Xu, Jianming; Di, Hongjie

    2016-11-12

    soil by altering soil conditions (particularly soil moisture) and related microbial communities.

  10. Pressure vessel deformation under in-vessel retention condition%熔融物堆内滞留条件下压力容器变形

    Institute of Scientific and Technical Information of China (English)

    温爽; 李铁萍; 李聪新; 高新力

    2016-01-01

    熔融物堆内滞留(In-Vessel Retention, IVR)已经成为第三代反应堆一项关键的严重事故缓解策略,而压力容器外部冷却(External Reactor Vessel Cooling, ERVC)技术则是保证IVR得以成功实施的关键。当发生堆芯熔化时,高温熔融物对压力容器(Reactor Pressure Vessel, RPV)下封头的热冲击会导致RPV壁面和由其构成的外部冷却通道的形状发生变化,使局部传热恶化,进而造成IVR的失效。因此,有必要对IVR条件下RPV壁面的变形进行研究。本文利用有限元软件ANSYS对RPV进行了几何建模、温度场分析和力学场分析。结果表明,在RPV外部实现冷却、内部实现泄压的前提下,壁面变形为13.85−18.75 mm。在1 MPa内压的作用下,高温蠕变会使壁面变形随时间增大,但其增量有限。热膨胀是造成壁面变形的主要因素。%Background: In-vessel retention (IVR) has become an important severe accident mitigation strategy for advanced light water reactor in recent years. The successful implementation of IVR depends on the external reactor vessel cooling (ERVC) technique. In case of core melt, the bottom head of reactor pressure vessel (RPV) becomes deformed due to the thermal impacts of high temperature, and causes the narrowing of external coolant channel which is the gap between pressure vessel outer wall and insulation layer. This phenomenon could lead to local heat transfer deterioration and then causes the failure of IVR.Purpose: The aim of this paper is to analyze the deformation of reactor pressure vessel under IVR condition.Methods: The thermal and mechanical calculations of reactor pressure vessel are performed by using the finite element methods. This work can be divided into two steps. The first step is the evaluation of the thermal field of RPV, and the second step is the calculation of stress and displacement of RPV based on its temperature fields.Results: The result shows that the maximum vertical

  11. Retentivity, selectivity and thermodynamic behavior of polycyclic aromatic hydrocarbons on charge-transfer and hypercrosslinked stationary phases under conditions of normal phase high performance liquid chromatography.

    Science.gov (United States)

    Jiang, Ping; Lucy, Charles A

    2016-03-11

    Charge-transfer and hypercrosslinked polystyrene phases offer retention and separation for polycyclic aromatic hydrocarbons (PAHs) and thus have potential for petroleum analysis. The size, shape and planarity selectivity for PAH standards on charge-transfer (DNAP column) and hypercrosslinked polystyrene (HC-Tol and 5HGN columns) phases are different under normal phase liquid chromatography (NPLC). The HC-Tol column behaves like a conventional NPLC column with low retention of PAHs. Retention of PAHs on the DNAP and 5HGN are strong and increases with the number of aromatic rings. The main retention mechanism is through π-π interactions and dipole-induced dipole interaction. Thermodynamics indicates that the retention mechanism of PAHs remains unchanged over the temperature range 20-60°C. In addition, on either DNAP or 5HGN column, both linear and bent PAHs are retained through the same mechanism. But DNAP possesses smaller π-π interaction and higher planarity selectivity than 5HGN for PAHs. This is suggestive that DNAP interacts with PAHs through a disordered phase arrangement, while 5HGN behaves as an ordered adsorption phase.

  12. Modulation of the genotoxicity of bleomycin by amines through noncovalent DNA interactions and alteration of physiological conditions in yeast

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, George R. [Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395 (United States)], E-mail: ghoffmann@holycross.edu; Gessner, Gabrielle S.; Hughes, Jennifer F.; Ronan, Matthew V.; Sylvia, Katelyn E.; Willett, Christine J. [Department of Biology, College of the Holy Cross, One College Street, Worcester, MA 01610-2395 (United States)

    2007-10-01

    noncovalent association with DNA, altered BLM access to DNA, and modulation of physiological conditions.

  13. Effect of chromatographic conditions on retention behavior and system efficiency for HPTLC of selected psychotropic drugs on chemically bonded stationary phases.

    Science.gov (United States)

    Petruczynik, Anna; Wróblewski, Karol; Waksmundzka-Hajnos, Monika

    2015-01-01

    Selected psychotropic drug standards have been chromatographed on RP18, CN and diol layers with a variety of aqueous and nonaqueous mobile phases. The effect of buffers at acidic or basic pH, acetic acid, ammonia and diethylamine (DEA) in aqueous mobile phases on retention, efficiency and peak symmetry was examined. Improved peak symmetry and separation selectivity for investigated compounds were observed when ammonia or DEA were used as mobile phase additives. The effect of diethylamine concentration in aqueous eluents on retention, peak symmetry and theoretical plate number obtained on CN plates was also investigated. Because of the strong retention of these basic drugs on stationary phases bonded on silica matrix, nonaqueous eluents containing medium polar diluents, strongly polar modifiers and silanol blockers (ammonia or diethylamine) were applied. Aqueous and nonaqueous eluent systems with the best selectivity and efficiency were used for separate psychotropic drug standards' mixture on CN layer by 2D TLC.

  14. Assessing inflow alterations into Lake Baikal from Selenga river basin with respect to changing climate and land use conditions

    Science.gov (United States)

    Moreido, Vsevolod; Kalugin, Andrey; Motovilov, Yuri; Millionshchikova, Tatiana

    2017-04-01

    The trans-boundary Selenga river basin is the largest tributary of Lake Baikal, which has been experiencing a profound increase of annual near-surface air temperature - 1.6 to 1.8⁰C during the last 70 years, nearly twice as global increase. A significant drought that has been registered in the Selenga basin for the last 20 years has drawn attention of a number of hydrologists worldwide to investigate its drivers. In this study we used the ECOMAG hydrological modeling software to construct a semi-distributed data-driven hydrological model that accounts for weather forcing, hydrological soil properties and land-use conditions to assess runoff generation in the river basin and its current and future response to climate and land-use alteration. Due to lack of daily weather observation data, the model was driven with EWEMBI weather dataset for calibration and validation purposes. To investigate the possible impact on runoff due to climate change in the XXI century we used an ensemble of 7 GCMs from CMIP5 experiment operating according to 4 IPCC greenhouse gas RCPs. To account for possible land-use changes we used HYDE dataset for the years 1990-2100. The modeling results show that the current drought conditions may be prolonged and intensified according to the most severe RCPs. At the same time, land-use conditions appear to have limited influence on the runoff generation for this area is not subject to heavy irrigation-intensive agriculture.

  15. Low temperature conditioning of garlic (Allium sativum L.) “seed” cloves induces alterations in sprouts proteome

    Science.gov (United States)

    Dufoo-Hurtado, Miguel D.; Huerta-Ocampo, José Á.; Barrera-Pacheco, Alberto; Barba de la Rosa, Ana P.; Mercado-Silva, Edmundo M.

    2015-01-01

    Low-temperature conditioning of garlic “seed” cloves substitutes the initial climatic requirements of the crop and accelerates the cycle. We have reported that “seed” bulbs from “Coreano” variety conditioned at 5°C for 5 weeks reduces growth and plant weight as well as the crop yields and increases the synthesis of phenolic compounds and anthocyanins. Therefore, this treatment suggests a cold stress. Plant acclimation to stress is associated with deep changes in proteome composition. Since proteins are directly involved in plant stress response, proteomics studies can significantly contribute to unravel the possible relationships between protein abundance and plant stress acclimation. The aim of this work was to study the changes in the protein profiles of garlic “seed” cloves subjected to conditioning at low-temperature using proteomics approach. Two sets of garlic bulbs were used, one set was stored at room temperature (23°C), and the other was conditioned at low temperature (5°C) for 5 weeks. Total soluble proteins were extracted from sprouts of cloves and separated by two-dimensional gel electrophoresis. Protein spots showing statistically significant changes in abundance were analyzed by LC-ESI-MS/MS and identified by database search analysis using the Mascot search engine. The results revealed that low-temperature conditioning of garlic “seed” cloves causes alterations in the accumulation of proteins involved in different physiological processes such as cellular growth, antioxidative/oxidative state, macromolecules transport, protein folding and transcription regulation process. The metabolic pathways affected include protein biosynthesis and quality control system, photosynthesis, photorespiration, energy production, and carbohydrate and nucleotide metabolism. These processes can work cooperatively to establish a new cellular homeostasis that might be related with the physiological and biochemical changes observed in previous studies

  16. The influence of production conditions, starting material and deposition environment on charcoal alteration in a tropical biome.

    Science.gov (United States)

    Ascough, Philippa; Bird, Michael; Meredith, Will; Large, David; Snape, Colin; Manion, Corinne

    2014-05-01

    Natural and anthropogenic burning events are a key link in the global carbon cycle, substantially influencing atmospheric CO2 levels, and consuming c.8700 teragrams yr-1 of dry biomass [1,2,3]. An important result of this process is charcoal, when lignocellulosic structures in biomass (e.g. wood) are converted to aromatic domains with high chemical stability. Charcoal is therefore not readily re-oxidized to CO2, with estimates of 5-7 ky for the half-life of charcoal carbon in soils [3,4]. Charcoal's high carbon content coupled with high environmental resistance has led to the concept of biochar as a valuable means of global carbon sequestration, capable of carbon offsets comparable to annual anthropogenic fuel emissions [5,6,7]. Charcoal is not, however, an environmentally inert substance, and at least some components of charcoal are susceptible to alteration in depositional environments. Despite the importance of charcoal in global carbon cycling, the mechanisms by which charcoal is altered in the environment remain, as yet, poorly understood. This fact limits our ability to properly incorporate both natural environmental charcoal and biochar into global carbon budgets. This study aimed to improve understanding of charcoal alteration in the environment by examining the influence of production conditions, starting material and deposition environment on the physical and chemical characteristics of charcoal at a field site in the Daintree rainforest. These factors have been identified as critical in determining the dynamics of charcoal in depositional environments [8,9] and climatic conditions at the field site (in Tropical Queensland, Australia) are likely to result in extensive alteration of charcoal. Charcoal from wood (Nothofagus spp.), algae (Enteromorpha spp.), and sugarcane (Saccharum spp.) biomass was produced at temperatures over 300-500°C and exposed to conditions of varying pH and vegetation cover. The effect of these variables on charcoal chemistry

  17. Turnover: strategies for staff retention.

    Science.gov (United States)

    SnowAntle, S

    1990-01-01

    This discussion has focused on a number of areas where organizations may find opportunities for more effectively managing employee retention. Given the multitude of causes and consequences, there is no one quick fix. Effective management of employee retention requires assessment of the entire human resources process, that is, recruitment, selection, job design, compensation, supervision, work conditions, etc. Regular and systematic diagnosis of turnover and implementation of multiple strategies and evaluation are needed (Mobley, 1982).

  18. Conditional postnatal deletion of the neonatal murine hepatic circadian gene, Npas2, alters the gut microbiome following restricted feeding.

    Science.gov (United States)

    O'Neil, Derek S; Stewart, Christopher J; Chu, Derrick M; Goodspeed, Danielle M; Gonzalez-Rodriguez, Pablo J; Shope, Cynthia D; Aagaard, Kjersti M

    2017-08-01

    We have recently shown in both non-human primates and in rodents that fetal and neonatal hepatic expression of the circadian transcription factor, Npas2, is modulated by a high fat maternal diet and plays a critical role in establishing life-long metabolic homeostasis. Similarly, we and others have also established the importance of the maternal and early postnatal diet on establishment of the early gut microbiome. We hypothesized that altered circadian gene expression solely in the neonatal liver would result in gut microbiome dysbiosis, especially with diet-induced metabolic stress (ie, restricted feeding). Using a murine model in which we conditionally knock out Npas2 in the neonatal liver, we aimed to determine the role of the circadian machinery in gut dysbiosis with restricted feeding. We collected fecal samples from liver Npas2 conditional knockout (n = 11) and wild-type (n = 13) reproductive-aged mice before (study day 0) and after the restricted feeding study (study day 17). Extracted DNA was sequenced using the MiSeq Illumina platform using primers specific for the V4 region of the 16S ribosomal DNA gene. The resulting sequences were quality filtered, aligned, and assigned taxonomy. Principal coordinate analysis was performed on unweighted and weighted UniFrac distances between samples with a permutation analysis of variance to assess clustering significance between groups. Microbial taxa that significantly differ between groups of interest was determined using linear discriminate analysis effect size and randomForrest. Principal coordinate analysis performed on weighted UniFrac distances between male conditional knockout and wild-type cohorts revealed that the gut microbiome of the mice did not differ by genotype at the start of the restricted feeding study but did differ by virtue of genotype at the end of the study (P = .001). Moreover, these differences could be at least partially attributed to restricted feeding-associated alterations in relative

  19. The pancreas is altered by in utero androgen exposure: implications for clinical conditions such as polycystic ovary syndrome (PCOS.

    Directory of Open Access Journals (Sweden)

    Mick Rae

    Full Text Available Using an ovine model of polycystic ovary syndrome (PCOS, (pregnant ewes injected with testosterone propionate (TP (100 mg twice weekly from day (d62 to d102 of d147 gestation (maternal injection - MI-TP, we previously reported female offspring with normal glucose tolerance but hyperinsulinemia. We therefore examined insulin signalling and pancreatic morphology in these offspring using quantitative (Q RT-PCR and western blotting. In addition the fetal pancreatic responses to MI-TP, and androgenic and estrogenic contributions to such responses (direct fetal injection (FI of TP (20 mg or diethylstilbestrol (DES (20 mg at d62 and d82 gestation were assessed at d90 gestation. Fetal plasma was assayed for insulin, testosterone and estradiol, pancreatic tissue was cultured, and expression of key β-cell developmental genes was assessed by QRT-PCR. In female d62MI-TP offspring insulin signalling was unaltered but there was a pancreatic phenotype with increased numbers of β-cells (P<0.05. The fetal pancreas expressed androgen receptors in islets and genes involved in β-cell development and function (PDX1, IGF1R, INSR and INS were up-regulated in female fetuses after d62MI-TP treatment (P<0.05-0.01. In addition the d62MI-TP pancreas showed increased insulin secretion under euglycaemic conditions (P<0.05 in vitro. The same effects were not seen in the male fetal pancreas or when MI-TP was started at d30, before the male programming window. As d62MI-TP increased both fetal plasma testosterone (P<0.05 and estradiol concentrations (P<0.05 we assessed the relative contribution of androgens and estrogens. FI-TP (commencing d62 (not FI-DES treatment caused elevated basal insulin secretion in vitro and the genes altered by d62MI-TP treatment were similarly altered by FI-TP but not FI-DES. In conclusion, androgen over-exposure alters fetal pancreatic development and β-cell numbers in offspring. These data suggest that that there may be a primary pancreatic

  20. Formation of Complex Amino Acid Precursors in Simulated Primitive Atmosphere and Their Alteration under Simulated Submarine Hydrothermal Conditions

    Science.gov (United States)

    Kobayashi, Kensei; Kurihara, Hironari; Hirako, Tomoaki; Obayashi, Yumiko; Kaneko, Takeo; Takano, Yoshinori; Yoshimura, Yoshitaka

    Since late 1970's a great number of submarine hydrothermal systems (SHSs) has been dis-covered, and they are considered possible sites of chemical evolution and generation of life on the Earth since their discovery in late 1970s. A number of experiments simulating the con-ditions of SHSs were conducted, and abiotic production and polymerization of amino acids were reported. Free amino acids were frequently used as starting materials to examine possible organic reactions in the simulation experiments. In our early studies, not free amino acids but complex amino acids precursors with large molecular weights were formed abiotically from simulated primitive Earth atmosphere (a mixture of CO, N2 and H2 O) (Takano et al., 2004). Such complex organics (hereafter referred as to CNWs) should have been delivered to SHSs in Primitive Ocean, where they were subjected to further alteration. We examined possible alteration of the complex organics in high-temperature high-pressure environments by the su-percritical water flow reactor (SCWFR) (Islam et al.. 2003) and an autoclave. CNWs were quite hydrophilic compounds whose molecular weights were ca. 3000. After heating 573 K for 2 min in the SCWFR, aggregates of organics were formed, which were separated from aque-ous solution with a Nucleopore filter (pore size: 200 nm). We propose the following scenario of chemical evolution: (1) Complex organics including amino acid precursors were formed in primitive atmosphere and/or extraterrestrial environments, (ii) they were delivered to primor-dial SHSs, (iii) hydrothermal alteration occurred in SHSs to give organic aggregates, (iv) quite primitive molecular systems with subtle biological functions were generated in the competition among such aggregates. References: Islam, Md. N., Kaneko, T., and Kobayashi, K (2003). Reactions of Amino Acids with a Newly ConstructedSupercritical Water Flow Reactor Simulating Submarine Hydrothermal Systems. Bull. Chem. Soc. Jpn., 76, 1171. Takano, Y

  1. Alteration of Basaltic Glass to Mg/Fe-Smectite under Acidic Conditions: A Potential Smectite Formation Mechanism on Mars

    Science.gov (United States)

    Peretyazhko, Tanya; Sutter, Brad; Ming, Douglas W.

    2014-01-01

    Phyllosilicates of the smectite group including Mg- and Fe-saponite and Fe(III)-rich nontronite have been identified on Mars. Smectites are believed to be formed under neutral to alkaline conditions that prevailed on early Mars. This hypothesis is supported by the observation of smectite and carbonate deposits in Noachian terrain on Mars. However, smectite may have formed under mildly acidic conditions. Abundant smectite formations have been detected as layered deposits hundreds of meters thick in intracrater depositional fans and plains sediments, while no large deposits of carbonates are found. Development of mildly acidic conditions at early Mars might allow formation of smectite but inhibit widespread carbonate precipitation. Little is known regarding the mechanisms of smectite formation from basaltic glass under acidic conditions. The objective of this study was to test a hypothesis that Mars-analogue basaltic glass alters to smectite minerals under acidic conditions (pH 4). The effects of Mg and Fe concentrations and temperature on smectite formation from basaltic glass were evaluated. Phyllosilicate synthesis was performed in batch reactors (Parr acid digestion vessel) under reducing hydrothermal conditions at 200 C and 100 C. Synthetic basaltic glass with a composition similar to that of the Gusev crater rock Adirondack (Ground surface APXS measurement) was used in these experiments. Basaltic glass was prepared by melting and quenching procedures. X-ray diffraction (XRD) analysis indicated that the synthesized glass was composed of olivine, magnetite and X-ray amorphous phase. Samples were prepared by mixing 250 mg Adirondack with 0.1 M acetic acid (final pH 4). In order to study influence of Mg concentration on smectite formation, experiments were performed with addition of 0, 1 and 10 mM MgCl2. After 1, 7 and 14 day incubations the solution composition was analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the altered glass and formed

  2. Post-operative urinary retention.

    Science.gov (United States)

    Steggall, Martin; Treacy, Colm; Jones, Mark

    Urinary retention is a common complication of surgery and anaesthesia. The risk of post-operative urinary retention is increased following certain surgical procedures and anaesthetic modalities, and with patients' advancing age. Patients at increased risk of post-operative urinary retention should be identified before surgery or the condition should be identified and treated in a timely manner following surgery. If conservative measures do not help the patient to pass urine, the bladder will need to be drained using either an intermittent catheter or an indwelling urethral catheter, which can result in catheter-associated urinary tract infections. This article provides an overview of normal bladder function, risk factors for developing post-operative urinary retention, and treatment options. Guidance drawn from the literature aims to assist nurses in identifying at-risk patients and inform patient care.

  3. Effect of the water content on the retention and enantioselectivity of albendazole and fenbendazole sulfoxides using amylose-based chiral stationary phases in organic-aqueous conditions.

    Science.gov (United States)

    Materazzo, Sabrina; Carradori, Simone; Ferretti, Rosella; Gallinella, Bruno; Secci, Daniela; Cirilli, Roberto

    2014-01-31

    Four commercially available immobilized amylose-derived CSPs (Chiralpak IA-3, Chiralpak ID-3, Chiralpak IE-3 and Chiralpak IF-3) were used in the HPLC analysis of the chiral sulfoxides albendazole (ABZ-SO) and fenbendazole (FBZ-SO) and their in vivo sulfide precursor (ABZ and FBZ) and sulfone metabolite (ABZ-SO2 and FBZ-SO2) under organic-aqueous mode. U-shape retention maps, established by varying the water content in the acetonitrile- and ethanol-water mobile phases, were indicative of two retention mechanisms operating on the same CSP. The dual retention behavior of polysaccharide-based CSPs was exploited to design greener enantioselective and chemoselective separations in a short time frame. The enantiomers of ABZ-SO and FBZ-SO were baseline resolved with water-rich mobile phases (with the main component usually being 50-65% water in acetonitrile) on the IF-3 CSP and ethanol-water 100:5 mixture on the IA-3 and IE-3 CSPs. A simultaneous separation of ABZ (or FBZ), enantiomers of the corresponding sulfoxide and sulfone was achieved on the IA-3 using ethanol-water 100:60 (acetonitrile-water 100:100 for FBZ) as a mobile phase.

  4. Antimicrobial therapy in critically ill patients: a review of pathophysiological conditions responsible for altered disposition and pharmacokinetic variability.

    Science.gov (United States)

    Pea, Federico; Viale, Pierluigi; Furlanut, Mario

    2005-01-01

    Antimicrobials are among the most important and commonly prescribed drugs in the management of critically ill patients. Selecting the appropriate antimicrobial at the commencement of therapy, both in terms of spectrum of activity and dose and frequency of administration according to concentration or time dependency, is mandatory in this setting. Despite appropriate standard dosage regimens, failure of the antimicrobial treatment may occur because of the inability of the antimicrobial to achieve adequate concentrations at the infection site through alterations in its pharmacokinetics due to underlying pathophysiological conditions. According to the intrinsic chemicophysical properties of antimicrobials, hydrophilic antimicrobials (beta-lactams, aminoglycosides, glycopeptides) have to be considered at much higher risk of inter- and intraindividual pharmacokinetic variations than lipophilic antimicrobials (macrolides, fluoroquinolones, tetracyclines, chloramphenicol, rifampicin [rifampin]) in critically ill patients, with significant frequent fluctuations of plasma concentrations that may require significant dosage adjustments. For example, underexposure may occur because of increased volume of distribution (as a result of oedema in sepsis and trauma, pleural effusion, ascites, mediastinitis, fluid therapy or indwelling post-surgical drainage) and/or enhanced renal clearance (as a result of burns, drug abuse, hyperdynamic conditions during sepsis, acute leukaemia or use of haemodynamically active drugs). On the other hand, overexposure may occur because of a drop in renal clearance caused by renal impairment. Care with all these factors whenever choosing an antimicrobial may substantially improve the outcome of antimicrobial therapy in critically ill patients. However, since these situations may often coexist in the same patient and pharmacokinetic variability may be unpredictable, the antimicrobial policy may further benefit from real-time application of therapeutic

  5. Presynaptic transporter-mediated release of glutamate evoked by the protonophore FCCP increases under altered gravity conditions

    Science.gov (United States)

    Borisova, T. A.; Krisanova, N. V.

    2008-12-01

    High-affinity Na +-dependent glutamate transporters of the plasma membrane mediate the glutamate uptake into neurons, and thus maintain low levels of extracellular glutamate in the synaptic cleft. The study focused on the release of glutamate by reversal of Na +-dependent glutamate transporters from rat brain nerve terminals (synaptosomes) under conditions of centrifuge-induced hypergravity. Flow cytometric analysis revealed similarity in the size and cytoplasmic granularity between synaptosomal preparations obtained from control and G-loaded animals (10 G, 1 h). The release of cytosolic L-[ 14C]glutamate from synaptosomes was evaluated using the protonophore FCCP, which dissipated synaptic vesicle proton gradient, thus synaptic vesicles were not able to keep glutamate inside and the latter enriched cytosol. FCCP per se induced the greater release of L-[ 14C]glutamate in hypergravity as compared to control (4.8 ± 1.0% and 8.0 ± 1.0% of total label). Exocytotic release of L-[ 14C]glutamate evoked by depolarization was reduced down to zero after FCCP application under both conditions studied. Depolarization stimulated release of cytosolic L-[ 14C]glutamate from synaptosomes preliminary treated with FCCP was considerably increased from 27.0 ± 2.2% of total label in control to 35.0 ± 2.3% in hypergravity. Non-transportable inhibitor of glutamate transporter DL-threo-β-benzyloxyaspartate was found to significantly inhibit high-KCl and FCCP-stimulated release of L-[ 14C]glutamate, confirming the release by reversal of glutamate transporters. The enhancement of transporter-mediated release of glutamate in hypergravity was found to result at least partially from the inhibition of the activity of Na/K-ATPase in the plasma membrane of synaptosomes. We suggested that hypergravity-induced alteration in transporter-mediated release of glutamate indicated hypoxic injury of neurons.

  6. Can retention forestry help conserve biodiversity? A meta-analysis.

    Science.gov (United States)

    Fedrowitz, Katja; Koricheva, Julia; Baker, Susan C; Lindenmayer, David B; Palik, Brian; Rosenvald, Raul; Beese, William; Franklin, Jerry F; Kouki, Jari; Macdonald, Ellen; Messier, Christian; Sverdrup-Thygeson, Anne; Gustafsson, Lena

    2014-12-01

    Industrial forestry typically leads to a simplified forest structure and altered species composition. Retention of trees at harvest was introduced about 25 years ago to mitigate negative impacts on biodiversity, mainly from clearcutting, and is now widely practiced in boreal and temperate regions. Despite numerous studies on response of flora and fauna to retention, no comprehensive review has summarized its effects on biodiversity in comparison to clearcuts as well as un-harvested forests. Using a systematic review protocol, we completed a meta-analysis of 78 studies including 944 comparisons of biodiversity between retention cuts and either clearcuts or un-harvested forests, with the main objective of assessing whether retention forestry helps, at least in the short term, to moderate the negative effects of clearcutting on flora and fauna. Retention cuts supported higher richness and a greater abundance of forest species than clearcuts as well as higher richness and abundance of open-habitat species than un-harvested forests. For all species taken together (i.e. forest species, open-habitat species, generalist species and unclassified species), richness was higher in retention cuts than in clearcuts. Retention cuts had negative impacts on some species compared to un-harvested forest, indicating that certain forest-interior species may not survive in retention cuts. Similarly, retention cuts were less suitable for some open-habitat species compared with clearcuts. Positive effects of retention cuts on richness of forest species increased with proportion of retained trees and time since harvest, but there were not enough data to analyse possible threshold effects, that is, levels at which effects on biodiversity diminish. Spatial arrangement of the trees (aggregated vs. dispersed) had no effect on either forest species or open-habitat species, although limited data may have hindered our capacity to identify responses. Results for different comparisons were largely

  7. A Study on Employee Retention Techniques

    OpenAIRE

    Savarimuthu, Dr. A; Hemalatha, N

    2013-01-01

    The objective of perusing this study is to assess the level of satisfaction of employee retention techniques at GB Engineering Enterprises PVT Limited., Trichy.This study gains significance because of employee retention techniques can be approached from various angles. It is desirable state of existence involving retention strategies generally fall in to one of four categories salary, working conditions, job enrichment and education. These four elements together constitute. The structure of e...

  8. Retention, dosing, tolerability and patient reported seizure outcome of Zonisamide as only add-on treatment under real-life conditions in adult patients with partial onset seizures: Results of the observational study ZOOM.

    Science.gov (United States)

    Hamer, Hajo; Baulac, Michel; McMurray, Rob; Kockelmann, Edgar

    2016-01-01

    Zonisamide is licensed for adjunctive therapy for partial-onset seizures with or without secondary generalisation in patients 6 years and older and as monotherapy for the treatment of partial seizures in adult patients with newly diagnosed epilepsy, and shows a favourable pharmacokinetic profile with low interaction potential with other drugs. The aim of the present study was to gather real-life data on retention and modalities of zonisamide use when administered as only add-on treatment to a current AED monotherapy in adult patients with partial-onset seizures. This multicenter observational study was performed in 4 European countries and comprised three visits: baseline, and after 3 and 6 months. Data on patients' retention, reported efficacy, tolerability and safety, and quality of life was collected. Of 100 included patients, 93 could be evaluated. After 6 months, the retention rate of zonisamide add-on therapy was 82.8%. At this time, a reduction of seizure frequency of at least 50% was observed in 79.7% of patients, with 43.6% reporting seizure freedom over the last 3 months of the study period. Adverse events were reported by 19.4% of patients, with fatigue, agitation, dizziness, and headache being most frequent. Approximately 25% of patients were older than 60 years, many of whom suffered from late-onset epilepsy. Compared to younger patients, these patients showed considerable differences with regard to their antiepileptic drug regimen at baseline, and slightly higher responder and retention rates at 6 months. Despite limitations due to the non-interventional open-label design and the low sample size, the results show that zonisamide as only add-on therapy is well retained, indicating effectiveness in the majority of patients under real-life conditions. Copyright © 2015. Published by Elsevier Ltd.

  9. Differential cloning of novel intestine-specific genes whose expression is altered under conditions of villus atrophy.

    Science.gov (United States)

    Hodin, R A; Meng, S; Shei, A

    1995-07-01

    Atrophy of the small intestinal villi occurs in a variety of disease states and is associated with diarrhea, malabsorption, and impaired barrier function. We have previously demonstrated that villus atrophy is associated with an increase in lactase and a decrease in intestinal alkaline phosphatase gene expression. Given these changes in enterocyte phenotype with villus atrophy, we speculated that there may be other intestine-specific genes whose expression is altered as a function of epithelial growth state. We have employed two molecular techniques in order to identify and clone complementary DNAs (cDNA) which are differentially expressed in atrophic compared to normal small intestinal mucosa. In differential cDNA library (+/-) screening, duplicate filters of a normal jejunal cDNA library are hybridized with radiolabeled cDNA probes from either atrophic or control tissues. Comparisons of the intensities of hybridized clones allows for the identification of differentially expressed gene products. In the mRNA differential display system, RT-PCR is used to randomly amplify mRNA species. Similar to cDNA library screening, comparisons of radiolabeled bands on a polyacrylamide sequencing gel allow for the identification of differentially expressed genes. Using these methods, we have identified a novel cDNA, called D9, which appears to be expressed exclusively in the intestinal mucosa. Northern analyses have confirmed that the expression of the D9 mRNA is dramatically decreased under conditions of villus atrophy, suggesting an underlying relationship with epithelial growth state. DNA sequence analysis (GenBank) reveals no identity to previously cloned genes.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Altered morphology of hippocampal dentate granule cell presynaptic and postsynaptic terminals following conditional deletion of TrkB.

    Science.gov (United States)

    Danzer, Steve C; Kotloski, Robert J; Walter, Cynthia; Hughes, Maya; McNamara, James O

    2008-01-01

    Dentate granule cells play a critical role in the function of the entorhinal-hippocampal circuitry in health and disease. Dentate granule cells are situated to regulate the flow of information into the hippocampus, a structure required for normal learning and memory. Correspondingly, impaired granule cell function leads to memory deficits, and, interestingly, altered granule cell connectivity may contribute to the hyperexcitability of limbic epilepsy. It is important, therefore, to understand the molecular determinants of synaptic connectivity of these neurons. Brain-derived neurotrophic factor and its receptor TrkB are expressed at high levels in the dentate gyrus (DG) of the hippocampus, and are implicated in regulating neuronal development, neuronal plasticity, learning, and the development of epilepsy. Whether and how TrkB regulates granule cell structure, however, is incompletely understood. To begin to elucidate the role of TrkB in regulating granule cell morphology, here we examine conditional TrkB knockout mice crossed to mice expressing green fluorescent protein in subsets of dentate granule cells. In stratum lucidum, where granule cell mossy fiber axons project, the density of giant mossy fiber boutons was unchanged, suggesting similar output to CA3 pyramidal cell targets. However, filopodial extensions of giant boutons, which contact inhibitory interneurons, were increased in number in TrkB knockout mice relative to wildtype controls, predicting enhanced feedforward inhibition of CA3 pyramidal cells. In knockout animals, dentate granule cells possessed fewer primary dendrites and enlarged dendritic spines, indicative of disrupted excitatory synaptic input to the granule cells. Together, these findings demonstrate that TrkB is required for development and/or maintenance of normal synaptic connectivity of the granule cells, thereby implying an important role for TrkB in the function of the granule cells and hippocampal circuitry.

  11. Differential gene regulation under altered gravity conditions in follicular thyroid cancer cells: relationship between the extracellular matrix and the cytoskeleton

    NARCIS (Netherlands)

    Ulbrich, C.; Pietsch, J.; Grosse, J.; Wehland, M.; Schulz, H.; Saar, K.; Hübner, N.; Hauslage, J.; Hemmersbach, R.; Braun, M.; van Loon, J.; Vagt, N.; Egli, M.; Richter, P.; Einspanier, R.; Sharbati, S.; Baltz, T.; Infanger, M.; Ma, X.; Grimm, D.

    2011-01-01

    Extracellular matrix proteins, adhesion molecules, and cytoskeletal proteins form a dynamic network interacting with signalling molecules as an adaptive response to altered gravity. An important issue is the exact differentiation between real microgravity responses of the cells or cellular reactions

  12. [The influence of acute hypoxia on motility of rats in the open field test under the conditions of an altered photoperiod].

    Science.gov (United States)

    Sopova, I Iu

    2014-01-01

    The influence of acute hypoxia on the motility of rats under the conditions of an altered photoperiod in the open field test was studied. Thus, keeping the animals in constant darkness after the modeling of acute hypoxia leads to the depression of locomotive and exploratory components of the behavior. At the same time the animals that were kept under the conditions of constant light show a change in the correlation between the components of motility after the action of hypoxia.

  13. Fuel nozzle tube retention

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  14. Conditional Cash Transfers Improve Retention in PMTCT Services by Mitigating the Negative Effect of Not Having Money to Come to the Clinic.

    Science.gov (United States)

    Yotebieng, Marcel; Moracco, Kathryn E; Thirumurthy, Harsha; Edmonds, Andrew; Tabala, Martine; Kawende, Bienvenu; Wenzi, Landry K; Okitolonda, Emile W; Behets, Frieda

    2017-02-01

    To elucidate the mechanisms by which a cash incentive intervention increases retention in prevention of mother-to-child transmission services. We used data from a randomized controlled trial in Kinshasa, Democratic Republic of Congo. Perceptual factors associated with loss to follow-up (LTFU) through 6 weeks postpartum were first identified. Then, binomial models were used to assess interactions between LTFU and identified factors, and the cash incentive intervention. Participants were less likely to be LTFU if they perceived HIV as a "very serious" health problem for their baby vs. not [risk difference (RD), -0.13; 95% confidence interval (CI): -0.30 to 0.04], if they believed it would be "very likely" to pass HIV to their baby if they did not take any HIV drug vs. not (RD, -0.15; 95% CI: -0.32 to 0.02), and if they anticipated that not having money would make it difficult for them to come to the clinic vs. not (RD, 0.12; 95% CI: -0.07 to 0.30). The effect of each of the 3 factors on LTFU was antagonistic to that of receiving the cash incentive intervention. The excess risk due to interaction between the cash incentive intervention and the anticipated difficulty of "not having money" to come to the clinic was exactly equal to the effect of removing this perceived barrier (excess risk due to interaction, -0.12; 95% CI: -0.35 to 0.10). Our analyses show that cash transfers improve retention in prevention of mother-to-child transmission services mainly by mitigating the negative effect of not having money to come to the clinic.

  15. Partitioning of the rare earths and actinides between R7T7 nuclear glass alteration products and solution according to disposal conditions; Partage des terres rares et des actinides entre solution et produits d`alteration du verre nucleaire type R7T7 en fonction des conditions de stockage

    Energy Technology Data Exchange (ETDEWEB)

    Menard, O.

    1995-10-25

    The alteration of nuclear glass by water is liable to release radionuclides into the environment. Determining the release kinetics of these elements and their aqueous chemical forms are therefore essential steps in establishing the safety of a geological repository site. Leach tests were conducted with a nonradioactive specimen of the French ``R7T7`` light water containment glass spiked with U and Th, and with two R7T7 specimens spiked with {sup 237}Np and {sup 239}Pu, respectively. The alteration solution compositions were representative of deep groundwater and contained carbonate, sulfate, phosphate, fluorine and chlorine ions. The release of U, Th, Np and Pu, as well as of the rare earths La, Ce and Nd were monitored by ICP mass spectrometry and by {alpha} spectrometry. Scanning and transmission electron microscopic examination of the nonradioactive altered glass surfaces was also performed to assess the partitioning balance for the rare earths, U and Th between the glass alteration products and solution. The mobility of these elements depends on two competing mechanisms. The rare earths and thorium are incorporated in the alteration products (gel); the retention process is assumed to involve chemisorption or coprecipitation, enhanced in the gel layer by the presence of phosphate ions in particular. Conversely, the aqueous species in the alteration solutions (mainly anions) form complexes with the actinides and rare earths; this phenomenon is particularly evident with U and Np. The presence of carbonate ions favors this mobility. Plutonium differs from U and Np in that it is adsorbed mainly on colloids formed by glass dissolution, the principal factors governing its chemical evolution in solution. (author). refs., 122 figs., 185 tabs.

  16. Alteration of R7T7-type nuclear glass in deep geological storage conditions; Alteration du verre de confinement de dechets type R7T7 en condition de stockage geologique

    Energy Technology Data Exchange (ETDEWEB)

    Combarieu, G. de

    2007-02-15

    This PhD thesis is aimed to study the alteration of SON68 glass, French inactive glass of R7T7-type, in contact with near field materials of a deep geological storage (French concept from ANDRA) which are mainly metallic iron and Callovo-Oxfordian clay. Therefore, experiments involving a 'glass-iron-clay' system at lab-scale have been carried out. Interactions between glass, iron and clay have been characterised from submicron to millimeter scale by means of SEM, TEM, XRD and XAS and Raman spectroscopies in terms of chemistry and crystal-chemistry. In the mean time, a conceptual model of glass alteration has been developed to account for most of the experimental observations and known mechanisms of alteration. The model has been then transposed within the transport-chemistry code HYTEC, together with developed models of clay and iron corrosion, to simulate the experiments described above. This work is thus a contribution to the understanding of iron corrosion in Callovo-Oxfordian clay and subsequent glass alteration in the newly formed corrosion products, the whole process being considered as a lab-scale model of a deep geological storage of radioactive wastes. (author)

  17. Progress of Radioactive Waste Treatment Technology:Study on Alteration of Simulated HLW Glass under Simulated Geological Disposal Condition

    Institute of Scientific and Technical Information of China (English)

    HUA; Xiao-hui; WANG; Lei; YOU; Xin-feng; ZHENG; Wen-jun; YANG; Lin-yue; LI; Yu-song; ZHENG; Yu; LI; Teng; ZHANG; Zhen-tao

    2015-01-01

    1/200 scale simulated disposal experimental device was set up in 2013 and operated from 2014,in which ground water penetrated host rock,buffer materials,container materials and simulated HLW glass.The leaching velocity,alteration of HLW glass and corrosion of container materials were investigated.Moreover,temperature,host rock,

  18. Implication of surface modified NZVI particle retention in the porous media: Assessment with the help of 1-D transport model

    Indian Academy of Sciences (India)

    Trishikhi Raychoudhury; Vikranth Kumar Surasani

    2017-06-01

    Retention of surface-modified nanoscale zero-valent iron (NZVI) particles in the porous media near the point of injection has been reported in the recent studies. Retention of excess particles in porous media can alter the media properties. The main objectives of this study are, therefore, to evaluate the effect of particle retention on the porous media properties and its implication on further NZVI particle transport under different flow conditions. To achieve the objectives, a one-dimensional transport model is developed by considering particle deposition, detachment, and straining mechanisms along with the effect of changes in porosity resulting from retention of NZVI particles. Two different flow conditions are considered for simulations. The first is a constant Darcy’s flow rate condition, which assumes a change in porosity, causes a change in pore water velocity and the second, is a constant head condition, which assumes the change in porosity, influence the permeability and hydraulic conductivity (thus Darcy’s flow rate). Overall a rapid decrease in porosity was observed as a result of high particle retention near the injection points resulting in a spatial distribution of deposition rate coefficient. In the case of constant head condition, the spatial distribution of Darcy’s velocities is predicted due to variation in porosity and hydraulic conductivity. The simulation results are compared with the data reported from the field studies; which suggests straining is likely to happen in the real field condition.

  19. Altered Morphology of Hippocampal Dentate Granule Cell Presynaptic and Postsynaptic Terminals Following Conditional Deletion of TrkB

    OpenAIRE

    Danzer, Steve C.; Kotloski, Robert J.; Walter, Cynthia; Hughes, Maya; McNamara, James O.

    2008-01-01

    Dentate granule cells play a critical role in the function of the entorhinal-hippocampal circuitry in health and disease. Dentate granule cells are situated to regulate the flow of information into the hippocampus, a structure required for normal learning and memory. Correspondingly, impaired granule cell function leads to memory deficits, and, interestingly, altered granule cell connectivity may contribute to the hyperexcitability of limbic epilepsy. It is important, therefore, to understand...

  20. Unlocking the Sporicidal Potential of Ethanol: Induced Sporicidal Activity of Ethanol against Clostridium difficile and Bacillus Spores under Altered Physical and Chemical Conditions.

    Directory of Open Access Journals (Sweden)

    Michelle M Nerandzic

    Full Text Available Due to their efficacy and convenience, alcohol-based hand sanitizers have been widely adopted as the primary method of hand hygiene in healthcare settings. However, alcohols lack activity against bacterial spores produced by pathogens such as Clostridium difficile and Bacillus anthracis. We hypothesized that sporicidal activity could be induced in alcohols through alteration of physical or chemical conditions that have been shown to degrade or allow penetration of spore coats.Acidification, alkalinization, and heating of ethanol induced rapid sporicidal activity against C. difficile, and to a lesser extent Bacillus thuringiensis and Bacillus subtilis. The sporicidal activity of acidified ethanol was enhanced by increasing ionic strength and mild elevations in temperature. On skin, sporicidal ethanol formulations were as effective as soap and water hand washing in reducing levels of C. difficile spores.These findings demonstrate that novel ethanol-based sporicidal hand hygiene formulations can be developed through alteration of physical and chemical conditions.

  1. Unlocking the Sporicidal Potential of Ethanol: Induced Sporicidal Activity of Ethanol against Clostridium difficile and Bacillus Spores under Altered Physical and Chemical Conditions

    Science.gov (United States)

    Nerandzic, Michelle M.; Sunkesula, Venkata C. K.; C., Thriveen Sankar; Setlow, Peter; Donskey, Curtis J.

    2015-01-01

    Background Due to their efficacy and convenience, alcohol-based hand sanitizers have been widely adopted as the primary method of hand hygiene in healthcare settings. However, alcohols lack activity against bacterial spores produced by pathogens such as Clostridium difficile and Bacillus anthracis. We hypothesized that sporicidal activity could be induced in alcohols through alteration of physical or chemical conditions that have been shown to degrade or allow penetration of spore coats. Principal Findings Acidification, alkalinization, and heating of ethanol induced rapid sporicidal activity against C. difficile, and to a lesser extent Bacillus thuringiensis and Bacillus subtilis. The sporicidal activity of acidified ethanol was enhanced by increasing ionic strength and mild elevations in temperature. On skin, sporicidal ethanol formulations were as effective as soap and water hand washing in reducing levels of C. difficile spores. Conclusions These findings demonstrate that novel ethanol-based sporicidal hand hygiene formulations can be developed through alteration of physical and chemical conditions. PMID:26177038

  2. The presence of the sexual partner and nutritional condition alter the Anastrepha obliqua MacQuart (Diptera: Tephritidae) protein discrimination threshold

    Energy Technology Data Exchange (ETDEWEB)

    Cresoni-Pereira, Carla; Zucoloto, Fernando S. [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Biologia

    2005-11-15

    The minimum protein amount that Anastrepha obliqua MacQuart can detect in its alimentary source is variable, though the causes of such variation are not very well known. In this study, the authors tested whether the sexual partners nutritional condition and presence devoid of direct contact alter the A. obliqua protein discrimination threshold. Male and female insects were assigned to groups as follows: (1) newly emerged, (2) deprived of protein source (yeast) during 18 days, (3) non-yeast-deprived during 18 days, (4) yeast-deprived in the presence of equally yeast-deprived sexual partners, (5) yeast-deprived in the presence of non-yeast-deprived partners, (6) non-yeast-deprived with yeast-deprived partners and (7) non-yeast-deprived with non-yeast-deprived partners. The sexual partners were maintained apart by a transparent plastic screen with small holes. Not only the males presence but also their nutritional condition have altered the females discrimination threshold, particularly when the females were deprived and when non- deprived females cohabited with deprived males. Therefore, the females threshold was determined by their own nutritional condition in addition to recognition of the males nutritional condition. The males discrimination threshold was higher for non-deprived subjects than for the deprived ones. The occurrence of responses in the absence of direct contact between males and females has shown that they may use a chemical mechanism for mutual recognition of the sexual partner nutritional condition. (author)

  3. Enhancement of Laccase Production from Pleurotus ostreatus PVCRSP-7 by altering the Nutritional Conditions using Response Surface Methodology

    OpenAIRE

    Potu Venkata Chiranjeevi; Moses Rajasekara Pandian; Sathish Thadikamala

    2014-01-01

    Submerged culture conditions for laccase production by Pleurotus ostreatus were optimized by response surface methodology (RSM). A total of six factors, carbon (glucose), nitrogen sources (urea and peptone), 2,5-xylidine (inducer), wheat bran (lignocellulosic material), and medium pH, were optimized. A total of 50 experiments were conducted, and the obtained data were modeled using a second-order polynomial. The optimized conditions show significant improvement in laccase expression, by appro...

  4. Psychologist Retention Factors.

    Science.gov (United States)

    RETENTION(PSYCHOLOGY), *JOB SATISFACTION, *ALL VOLUNTEER, MANAGEMENT PLANNING AND CONTROL, ATTITUDES(PSYCHOLOGY), DEMOGRAPHY, ATTRITION, SURVEYS, QUESTIONNAIRES, PERCEPTION (PSYCHOLOGY), PSYCHOLOGISTS .

  5. Children with specific language impairment are not impaired in the acquisition and retention of Pavlovian delay and trace conditioning of the eyeblink response.

    Science.gov (United States)

    Hardiman, Mervyn J; Hsu, Hsin-jen; Bishop, Dorothy V M

    2013-12-01

    Three converging lines of evidence have suggested that cerebellar abnormality is implicated in developmental language and literacy problems. First, some brain imaging studies have linked abnormalities in cerebellar grey matter to dyslexia and specific language impairment (SLI). Second, theoretical accounts of both dyslexia and SLI have postulated impairments of procedural learning and automatisation of skills, functions that are known to be mediated by the cerebellum. Third, motor learning has been shown to be abnormal in some studies of both disorders. We assessed the integrity of face related regions of the cerebellum using Pavlovian eyeblink conditioning in 7-11year-old children with SLI. We found no relationship between oral language skills or literacy skills with either delay or trace conditioning in the children. We conclude that this elementary form of associative learning is intact in children with impaired language or literacy development. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Avoidance Prone Individuals Self Reporting Behavioral Inhibition Exhibit Facilitated Acquisition and Altered Extinction of Conditioned Eyeblinks With Partial Reinforcement Schedules

    Directory of Open Access Journals (Sweden)

    Michael Todd Allen

    2014-10-01

    Full Text Available Avoidance in the face of novel situations or uncertainty is a prime feature of behavioral inhibition which has been put forth as a risk factor for the development of anxiety disorders. Recent work has found that behaviorally inhibited individuals acquire conditioned eyeblinks faster than non-inhibited individuals in omission and yoked paradigms in which the predictive relationship between the conditioned stimulus (CS and unconditional stimulus (US is less than optimal as compared to standard training with CS-US paired trials (Holloway et al., 2014. In the current study, we tested explicitly partial schedules in which half the trials were CS alone or US alone trials in addition to the standard CS-US paired trials. One hundred and forty nine college-aged undergraduates participated in the study. All participants completed the Adult Measure of Behavioral Inhibition (i.e., AMBI which was used to group participants as behaviorally inhibited and non-inhibited. Eyeblink conditioning consisted of 3 US alone trials, 60 acquisition trials, and 20 CS-alone extinction trials presented in one session. Conditioning stimuli were a 500 ms tone conditioned stimulus (CS and a 50-ms air puff unconditional stimulus (US. Behaviorally inhibited individuals receiving 50% partial reinforcement with CS alone or US alone trials produced facilitated acquisition as compared to non-inhibited individuals. A partial reinforcement extinction effect was evident with CS alone trials in behaviorally inhibited but not non-inhibited individuals. These current findings indicate that avoidance prone individuals self-reporting behavioral inhibition over-learn an association and are slow to extinguish conditioned responses when there is some level of uncertainty between paired trials and CS or US alone presentations.

  7. Enhancement of Laccase Production from Pleurotus ostreatus PVCRSP-7 by altering the Nutritional Conditions using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Potu Venkata Chiranjeevi

    2014-05-01

    Full Text Available Submerged culture conditions for laccase production by Pleurotus ostreatus were optimized by response surface methodology (RSM. A total of six factors, carbon (glucose, nitrogen sources (urea and peptone, 2,5-xylidine (inducer, wheat bran (lignocellulosic material, and medium pH, were optimized. A total of 50 experiments were conducted, and the obtained data were modeled using a second-order polynomial. The optimized conditions show significant improvement in laccase expression, by approximately 3.5-fold (12,124 U/L.

  8. Region-Specific Involvement of Actin Rearrangement-Related Synaptic Structure Alterations in Conditioned Taste Aversion Memory

    Science.gov (United States)

    Bi, Ai-Ling; Wang, Yue; Li, Bo-Qin; Wang, Qian-Qian; Ma, Ling; Yu, Hui; Zhao, Ling; Chen, Zhe-Yu

    2010-01-01

    Actin rearrangement plays an essential role in learning and memory; however, the spatial and temporal regulation of actin dynamics in different phases of associative memory has not been fully understood. Here, using the conditioned taste aversion (CTA) paradigm, we investigated the region-specific involvement of actin rearrangement-related…

  9. Natal conditions alter age-specific reproduction but not survival or senescence in a long-lived bird of prey.

    Science.gov (United States)

    Millon, Alexandre; Petty, Steve J; Little, Brian; Lambin, Xavier

    2011-09-01

    1. Natal conditions and senescence are two major factors shaping life-history traits of wild animals. However, such factors have rarely been investigated together, and it remains largely unknown whether they interact to affect age-specific performance. 2. We used 27 years of longitudinal data collected on tawny owls with estimates of prey density (field voles) from Kielder Forest (UK) to investigate how prey density at birth affects ageing patterns in reproduction and survival. 3. Natal conditions experienced by tawny owls, measured in terms of vole density, dramatically varied among cohorts and explained 87% of the deviance in first-year apparent survival (annual estimates ranging from 0·07 to 0·33). 4. We found evidence for senescence in survival for females as well as for males. Model-averaged estimates showed that adult survival probability declined linearly with age for females from age 1. In contrast, male survival probability, lower on average than for female, declined after a plateau at age 1-3. 5. We also found evidence for reproductive senescence (number of offspring). For females, reproductive performance increased until age 9 then declined. Males showed an earlier decline in reproductive performance with an onset of senescence at age 3. 6. Long-lasting effects of natal environmental conditions were sex specific. Female reproductive performance was substantially related to natal conditions (difference of 0·24 fledgling per breeding event between females born in the first or third quartile of vole density), whereas male performance was not. We found no evidence for tawny owls born in years with low prey density having accelerated rates of senescence. 7. Our results, combined with previous findings, suggest the way natal environmental conditions affect senescence varies not only across species but also within species according to gender and the demographic trait considered.

  10. Avoidance prone individuals self reporting behavioral inhibition exhibit facilitated acquisition and altered extinction of conditioned eyeblinks with partial reinforcement schedules.

    Science.gov (United States)

    Allen, Michael Todd; Myers, Catherine E; Servatius, Richard J

    2014-01-01

    Avoidance in the face of novel situations or uncertainty is a prime feature of behavioral inhibition which has been put forth as a risk factor for the development of anxiety disorders. Recent work has found that behaviorally inhibited (BI) individuals acquire conditioned eyeblinks faster than non-inhibited (NI) individuals in omission and yoked paradigms in which the predictive relationship between the conditioned stimulus (CS) and unconditional stimulus (US) is less than optimal as compared to standard training with CS-US paired trials (Holloway et al., 2014). In the current study, we tested explicitly partial schedules in which half the trials were CS alone or US alone trials in addition to the standard CS-US paired trials. One hundred and forty nine college-aged undergraduates participated in the study. All participants completed the Adult Measure of Behavioral Inhibition (i.e., AMBI) which was used to group participants as BI and NI. Eyeblink conditioning consisted of three US alone trials, 60 acquisition trials, and 20 CS-alone extinction trials presented in one session. Conditioning stimuli were a 500 ms tone CS and a 50-ms air puff US. Behaviorally inhibited individuals receiving 50% partial reinforcement with CS alone or US alone trials produced facilitated acquisition as compared to NI individuals. A partial reinforcement extinction effect (PREE) was evident with CS alone trials in BI but not NI individuals. These current findings indicate that avoidance prone individuals self-reporting behavioral inhibition over-learn an association and are slow to extinguish conditioned responses (CRs) when there is some level of uncertainty between paired trials and CS or US alone presentations.

  11. Altered reproduction in fish exposed to pulp and paper mill effluents: roles of individual compounds and mill operating conditions.

    Science.gov (United States)

    Hewitt, L Mark; Kovacs, Tibor G; Dubé, Monique G; MacLatchy, Deborah L; Martel, Pierre H; McMaster, Mark E; Paice, Michael G; Parrott, Joanne L; van den Heuvel, Michael R; van der Kraak, Glen J

    2008-03-01

    For the last 20 years, studies conducted in North America, Scandinavia, and New Zealand have shown that pulp and paper mill effluents affect fish reproduction. Despite the level of effort applied, few leads are available regarding the factors responsible. Effluents affect reproduction in multiple fish species, as evidenced by decreased gonad size, decreased circulating and gonadal production of reproductive steroids, altered expression of secondary sex characteristics, and decreased egg production. Several studies also have shown that effluent constituents are capable of accumulating in fish and binding to sex steroid receptors/ binding proteins. Studies aimed at isolating biologically active substances within the pulping and papermaking process have provided clues about their source, and work has progressed in identifying opportunities for in-mill treatment technologies. Following comparisons of manufacturing processes and fish responses before and after process changes, it can be concluded that effluent from all types of mill processes are capable of affecting fish reproduction and that any improvements could not be attributed to a specific process modification (because mills normally performed multiple modifications simultaneously). Improved reproductive performance in fish generally was associated with reduced use of molecular chlorine, improved condensate handling, and liquor spill control. Effluent biotreatment has been effective in reducing some effects, but biotreated effluents also have shown no difference or an exacerbation of effects. The role of biotreatment in relation to effects on fish reproduction remains unclear and needs to be resolved.

  12. Alteration of functional state of peripheral blood erythrocytes in women of different age groups at dislipidemia conditions.

    Science.gov (United States)

    Ratiani, L; Intskirveli, N; Ormotsadze, G; Sanikidze, T

    2011-12-01

    The aim of the study was identification of statistically reliable correlations and the cause-effect relationships between viability of red blood cells and dislipidema parametres and/or metabolic disorders, induced by age related alterations of estrogen content, in women of different ages (reproductive, menopausal) On the basis of the analysis of research results we can conclude that in the different age groups of women with atherosclerosis-induced cardiovascular diseases revealed estrogen-related dependence between Tg-s and HDL content, functional status of phereperial blood erytrotcites and severity of dislipidemia. The aterogenic index Tg/HD proved to be sensitive marker of dislipidemia in reproductive aging women, but does't reflect disorders of lipid metabolism in postmenosal women. It was proved the existence of reliable corelation between red blood cells dysfunction indicator, spherulation quality, and atherogenic index Tg/HDL highlights; however, the correlation coefficient is 2 times higher in the reproductive age as in menopause. Spherulation quality of red blood cells at low HDL content showd fast growth rate in reproductive-aged women, and was unsensetive to HDL content in postmenopasal women. It was concluded that age-related lack of estrogens in postmenopausal women indirectly contributes to decrease protection of red blood cells against oxidative damage, reduces their deformabelity and disturbances the rheological properties. So, Spherulation quality of red blood cells may be used as a diagnostic marker of severity of atherosclerosis.

  13. [Electrical activity of the visual cortex under conditions of altered monoamine levels in the brain of animals].

    Science.gov (United States)

    Vorob'ev, V V; Gal'chenko, A A; Deriugina, O N

    1990-01-01

    In experiments on 8 rabbits and 12 rats changes in electrograms of the visual cortex of alert animals were studied under photic stimulation in conditions of pharmacological action on monoamine (MA) brain systems. After injection of MA precursors (5-oxitriptophane and d, 1-dioxiphenylalanine) following phenomena were observed: a) decrease of the amplitude of the averaged evoked potentials to rhythmic photic stimuli (1-20 imp. sec.-1); b) an enhancement of fast (15-25 Hz) oscillations in the cortical spontaneous electrical activity and weakening and modification of the effects of the blockader of synthesis of MA-alpha-methyl-dioxiphenylalanine. Under light stimulation potentiation of MA precursors effects was observed in the frequency spectra of electrocorticograms. In the same conditions the specificity of action of cathecholamines precursor was revealed in the form of an increase of power of rhythms of 5-7 Hz and it; decrease in 2-3 Hz. Possible mechanisms of the revealed phenomena are discussed.

  14. Stomatal malfunctioning under low VPD conditions: induced by alterations in stomatal morphology and leaf anatomy or in the ABA signaling?

    Science.gov (United States)

    Aliniaeifard, Sasan; Malcolm Matamoros, Priscila; van Meeteren, Uulke

    2014-12-01

    Exposing plants to low VPD reduces leaf capacity to maintain adequate water status thereafter. To find the impact of VPD on functioning of stomata, stomatal morphology and leaf anatomy, fava bean plants were grown at low (L, 0.23 kPa) or moderate (M, 1.17 kPa) VPDs and some plants that developed their leaves at moderate VPD were then transferred for 4 days to low VPD (M→L). Part of the M→L-plants were sprayed with ABA (abscisic acid) during exposure to L. L-plants showed bigger stomata, larger pore area, thinner leaves and less spongy cells compared with M-plants. Stomatal morphology (except aperture) and leaf anatomy of the M→L-plants were almost similar to the M-plants, while their transpiration rate and stomatal conductance were identical to that of L-plants. The stomatal response to ABA was lost in L-plants, but also after 1-day exposure of M-plants to low VPD. The level of foliar ABA sharply decreased within 1-day exposure to L, while the level of ABA-GE (ABA-glucose ester) was not affected. Spraying ABA during the exposure to L prevented loss of stomatal closing response thereafter. The effect of low VPD was largely depending on exposure time: the stomatal responsiveness to ABA was lost after 1-day exposure to low VPD, while the responsiveness to desiccation was gradually lost during 4-day exposure to low VPD. Leaf anatomical and stomatal morphological alterations due to low VPD were not the main cause of loss of stomatal closure response to closing stimuli.

  15. Ophthalmic Alterations in the Sturge-Weber Syndrome, Klippel-Trenaunay Syndrome, and the Phakomatosis Pigmentovascularis: An Independent Group of Conditions?

    Directory of Open Access Journals (Sweden)

    Solmaz Abdolrahimzadeh

    2015-01-01

    Full Text Available The phakomatoses have been traditionally defined as a group of hereditary diseases with variable expressivity characterized by multisystem tumors with possible malignant transformation. The Sturge-Weber syndrome, Klippel-Trenaunay syndrome, and the phakomatosis pigmentovascularis have the facial port-wine stain in common. Numerous pathophysiogenetic mechanisms have been suggested such as venous dysplasia of the emissary veins in the intracranial circulation, neural crest alterations leading to alterations of autonomic perivascular nerves, mutation of the GNAO gene in the Sturge-Weber syndrome, PIK3CA mutation in malformative/overgrowth syndromes such as the Klippel-Trenaunay syndrome, and the twin-spotting phenomenon in phakomatosis pigmentovascularis. Other features linked to the port-wine stain and typical to all of the three conditions are glaucoma and choroidal alterations. Glaucoma can be due to malformations of the anterior chamber or high episcleral venous pressure and in phakomatosis pigmentovascularis it can also be associated with angle hyperpigmentation. The choroid can be thickened in all diseases. Furthermore, choroidal melanocytosis in the phakomatosis pigmentovascularis can lead to malignant transformation. Although the multiple pathophysiological mechanisms still require clarification, similarities in ophthalmic manifestations make it reasonable to classify these diseases in an independent group.

  16. Alteration of Drosophila life span using conditional, tissue-specific expression of transgenes triggered by doxycycline or RU486/Mifepristone

    OpenAIRE

    Ford, Daniel; Hoe, Nicholas; Landis, Gary N.; Tozer, Kevin; Luu, Allan; Bhole, Deepak; Badrinath, Ananth; Tower, John

    2007-01-01

    The conditional systems Tet-on and Geneswitch were compared and optimized for the tissue-specific expression of transgenes and manipulation of life span in adult Drosophila. Two versions of Tet-on system reverse-tetracycline-Trans-Activator (rtTA) were compared: the original rtTA, and rtTAM2-alt containing mutations designed to optimize regulation and expression. The rtTAM2-alt version gave less leaky expression of target constructs in the absence of doxycycline, however the absolute level of...

  17. Conditioned response suppression in the IntelliCage: assessment of mouse strain differences and effects of hippocampal and striatal lesions on acquisition and retention of memory.

    Science.gov (United States)

    Voikar, Vootele; Colacicco, Giovanni; Gruber, Oliver; Vannoni, Elisabetta; Lipp, Hans-Peter; Wolfer, David P

    2010-12-01

    The IntelliCage allows fully automated continuous testing of various behaviours in the home cage environment without handling the mice. Here we tested whether conditioned avoidance is retained after a time period delay spent outside the IntelliCage. During the training, nosepokes in one of the four learning corners were punished with an air-puff. After 24h of training, the mice were placed in regular cages for 24h. During the last 18h of this interval, the mice were water deprived and then returned to the IntelliCage for a probe trial where drinking was allowed in all corners. The C57BL/6 mice developed a significant suppression of nosepoking in the punished corner during training, and the avoidance was carried over to the following probe trial. Repetition of the experiment by delivering punishment in a different corner assigned to individual mice revealed a similar performance pattern. Comparison between the different strains revealed a reduced nosepoke suppression in DBA/2 and B6D2F1 mice as compared to C57BL/6 mice in the probe trial, despite similar error rates during the training with short (1-s) air-puffs. However, the performance of the three strains in the probe trial were equalised when the air-puffs were prolonged until the end of the corner visit. Significant extinction of the nosepoke suppression occurred after 6 days. A prolonged interval (7 days) between the training and the probe trial resulted in a loss of suppression in DBA/2 mice, but not in C57BL/6 and B6D2F1 mice. Additional experiments revealed that performance in the probe trial was dependent on a complex set of intramaze cues. Testing of mice with bilateral excitotoxic lesions of the hippocampus or dorso-lateral striatum revealed that learning this task was dependent on an intact hippocampus, but not on an intact striatum. In summary, the conditioned nosepoke suppression test presented here is sensitive to both genetic differences and hippocampal lesions. This test could be applied to the

  18. Altered physiological conditions of the terrestrial isopod Porcellio scaber as a measure of subchronic TiO2 effects.

    Science.gov (United States)

    Srpčič, Anja Menard; Drobne, Damjana; Novak, Sara

    2015-03-01

    Titanium dioxide nanoparticles (nano-TiO2) show low toxic potential against a variety of environmental organisms when measured by conventional toxicity endpoints. However, the question is whether the conventional measures of toxicity can define the adverse effects of nanoparticles. The aim of this study was to asses the potential toxic and cytotoxic effects of the ingested nano-TiO2 (anatase, Porcellio scaber. In addition to conventional toxicity parameters, the physiological condition of the animals was assessed. Following 28-day feeding exposure to nano-TiO2 at concentrations up to 5,000 μg nano-TiO2/g leaf dry weight, no toxic or cytotoxic effects were demonstrated. However, the physiological condition of the animals was affected in a dose-dependent manner. The physiological state of organisms is an important parameter to assess the potential population implications due to the exposure to nanomaterials. Therefore, we suggest that only if both, the physiological state of the animals exposed to nano-TiO2 and the conventional toxicity markers show no effects, the exposure dose can be interpreted as non-hazardous.

  19. Altered vocal fold kinematics in synthetic self-oscillating models that employ adipose tissue as a lateral boundary condition.

    Science.gov (United States)

    Saidi, Hiba; Erath, Byron D.

    2015-11-01

    The vocal folds play a major role in human communication by initiating voiced sound production. During voiced speech, the vocal folds are set into sustained vibrations. Synthetic self-oscillating vocal fold models are regularly employed to gain insight into flow-structure interactions governing the phonation process. Commonly, a fixed boundary condition is applied to the lateral, anterior, and posterior sides of the synthetic vocal fold models. However, physiological observations reveal the presence of adipose tissue on the lateral surface between the thyroid cartilage and the vocal folds. The goal of this study is to investigate the influence of including this substrate layer of adipose tissue on the dynamics of phonation. For a more realistic representation of the human vocal folds, synthetic multi-layer vocal fold models have been fabricated and tested while including a soft lateral layer representative of adipose tissue. Phonation parameters have been collected and are compared to those of the standard vocal fold models. Results show that vocal fold kinematics are affected by adding the adipose tissue layer as a new boundary condition.

  20. Differential gene expression of human chondrocytes cultured under short-term altered gravity conditions during parabolic flight maneuvers.

    Science.gov (United States)

    Wehland, Markus; Aleshcheva, Ganna; Schulz, Herbert; Saar, Katrin; Hübner, Norbert; Hemmersbach, Ruth; Braun, Markus; Ma, Xiao; Frett, Timo; Warnke, Elisabeth; Riwaldt, Stefan; Pietsch, Jessica; Corydon, Thomas Juhl; Infanger, Manfred; Grimm, Daniela

    2015-03-20

    Chondrocytes are the main cellular component of articular cartilage. In healthy tissue, they are embedded in a strong but elastic extracelluar matrix providing resistance against mechanical forces and friction for the joints. Osteoarthritic cartilage, however, disrupted by heavy strain, has only very limited potential to heal. One future possibility to replace damaged cartilage might be the scaffold-free growth of chondrocytes in microgravity to form 3D aggregates. To prepare for this, we have conducted experiments during the 20th DLR parabolic flight campaign, where we fixed the cells after the first (1P) and the 31st parabola (31P). Furthermore, we subjected chondrocytes to isolated vibration and hypergravity conditions. Microarray and quantitative real time PCR analyses revealed that hypergravity regulated genes connected to cartilage integrity (BMP4, MMP3, MMP10, EDN1, WNT5A, BIRC3). Vibration was clearly detrimental to cartilage (upregulated inflammatory IL6 and IL8, downregulated growth factors EGF, VEGF, FGF17). The viability of the cells was not affected by the parabolic flight, but showed a significantly increased expression of anti-apoptotic genes after 31 parabolas. The IL-6 release of chondrocytes cultured under conditions of vibration was not changed, but hypergravity (1.8 g) induced a clear elevation of IL-6 protein in the supernatant compared with corresponding control samples. Taken together, this study provided new insights into the growth behavior of chondrocytes under short-term microgravity.

  1. conditions

    Directory of Open Access Journals (Sweden)

    M. Venkatesulu

    1996-01-01

    Full Text Available Solutions of initial value problems associated with a pair of ordinary differential systems (L1,L2 defined on two adjacent intervals I1 and I2 and satisfying certain interface-spatial conditions at the common end (interface point are studied.

  2. Red:far-red light conditions affect the emission of volatile organic compounds from barley (Hordeum vulgare), leading to altered biomass allocation in neighbouring plants.

    Science.gov (United States)

    Kegge, Wouter; Ninkovic, Velemir; Glinwood, Robert; Welschen, Rob A M; Voesenek, Laurentius A C J; Pierik, Ronald

    2015-05-01

    Volatile organic compounds (VOCs) play various roles in plant-plant interactions, and constitutively produced VOCs might act as a cue to sense neighbouring plants. Previous studies have shown that VOCs emitted from the barley (Hordeum vulgare) cultivar 'Alva' cause changes in biomass allocation in plants of the cultivar 'Kara'. Other studies have shown that shading and the low red:far-red (R:FR) conditions that prevail at high plant densities can reduce the quantity and alter the composition of the VOCs emitted by Arabidopsis thaliana, but whether this affects plant-plant signalling remains unknown. This study therefore examines the effects of far-red light enrichment on VOC emissions and plant-plant signalling between 'Alva' and 'Kara'. The proximity of neighbouring plants was mimicked by supplemental far-red light treatment of VOC emitter plants of barley grown in growth chambers. Volatiles emitted by 'Alva' under control and far-red light-enriched conditions were analysed using gas chromatography-mass spectrometry (GC-MS). 'Kara' plants were exposed to the VOC blend emitted by the 'Alva' plants that were subjected to either of the light treatments. Dry matter partitioning, leaf area, stem and total root length were determined for 'Kara' plants exposed to 'Alva' VOCs, and also for 'Alva' plants exposed to either control or far-red-enriched light treatments. Total VOC emissions by 'Alva' were reduced under low R:FR conditions compared with control light conditions, although individual volatile compounds were found to be either suppressed, induced or not affected by R:FR. The altered composition of the VOC blend emitted by 'Alva' plants exposed to low R:FR was found to affect carbon allocation in receiver plants of 'Kara'. The results indicate that changes in R:FR light conditions influence the emissions of VOCs in barley, and that these altered emissions affect VOC-mediated plant-plant interactions. © The Author 2015. Published by Oxford University Press on

  3. Chronic but not acute antidepresant treatment alters serum zinc/copper ratio under pathological/zinc-deficient conditions in mice.

    Science.gov (United States)

    Mlyniec, K; Ostachowicz, B; Krakowska, A; Reczynski, W; Opoka, W; Nowak, G

    2014-10-01

    Depression is the leading psychiatric disorder with a high risk of morbidity and mortality. Clinical studies report lower serum zinc in depressed patients, suggesting a strong link between zinc and mood disorders. Also copper as an antagonistic element to zinc seems to play a role in depression, where elevated concentration is observed. In the present study we investigated serum copper and zinc concentration after acute or chronic antidepressant (AD) treatment under pathological/zinc-deficient conditions. Zinc deficiency in mice was induced by a special diet administered for 6 weeks (zinc adequate diet - ZnA, contains 33.5 mgZn/kg; zinc deficient diet - ZnD, contains 0.2 mgZn/kg). Animals received acute or chronically saline (control), imipramine, escitalopram, reboxetine or bupropion. To evaluate changes in serum copper and zinc concentrations the total reflection X-ray fluorescence (TXRF) and flame atomic absorption spectrometry (FAAS) was performed. In ZnD animals serum zinc level was reduced after acute ADs treatment (similarly to vehicle treatment), however, as demonstrated in the previous study after chronic ADs administration no differences between both ZnA and ZnD groups were observed. Acute ADs in ZnD animals caused different changes in serum copper concentration with no changes after chronic ADs treatment. The calculated serum Zn/Cu ratio is reduced in ZnD animals (compared to ZnA subjects) treated with saline (acutely or chronically) and in animals treated acutely with ADs. However, chronic treatment with ADs normalized (by escitalopram, reboxetine or bupropion) or increased (by imipramine) this Zn/Cu ratio. Observed in this study normalization of serum Zn/Cu ratio in depression-like conditions by chronic (but not acute) antidepressants suggest that this ratio may be consider as a marker of depression or treatment efficacy.

  4. Alteration of histone acetylation pattern during long-term serum-free culture conditions of human fetal placental mesenchymal stem cells.

    Science.gov (United States)

    Zhu, Yongzhao; Song, Xumei; Han, Fei; Li, Yukui; Wei, Jun; Liu, Xiaoming

    2015-01-01

    Increasing evidence suggests that the mesenchymal stem cells (MSCs) derived from placenta of fetal origin (fPMSCs) are superior to MSCs of other sources for cell therapy. Since the initial number of isolated MSCs is limited, in vitro propagation is often required to reach sufficient numbers of cells for therapeutic applications, during which MSCs may undergo genetic and/or epigenetic alterations that subsequently increase the probability of spontaneous malignant transformation. Thus, factors that influence genomic and epigenetic stability of MSCs following long-term expansions need to be clarified before cultured MSCs are employed for clinical settings. To date, the genetic and epigenetic stability of fPMSCs after long-term in vitro expansion has not been fully investigated. In this report, alterations to histone acetylation and consequence on the expression pattern of fPMSCs following in vitro propagation under serum-free conditions were explored. The results show that fPMSCs maintain their MSC characteristics before they reached a senescent state. Furthermore, acetylation modification patterns were changed in fPMSCs along with gradually increased global histone deacetylase (HDAC) activity and expression of HDAC subtypes HDAC4, HDAC5 and HDAC6, as well as a down-regulated global histone H3/H4 acetylation during in vitro culturing. In line with the acetylation alterations, the expression of oncogenes Oct4, Sox2 and TERT were significantly decreased over the propagation period. Of note, the down-regulation of Oct4 was strongly associated with changes in acetylation. Intriguingly, telomere length in fPMSCs did not significantly change during the propagating process. These findings suggest that human fPMSCs may be a safe and reliable resource of MSCs and can be propagated under serum-free conditions with less risk of spontaneous malignancy, and warrants further validation in clinical settings.

  5. Synaptic plasticity and NO-cGMP-PKG signaling regulate pre- and postsynaptic alterations at rat lateral amygdala synapses following fear conditioning.

    Directory of Open Access Journals (Sweden)

    Kristie T Ota

    Full Text Available In vertebrate models of synaptic plasticity, signaling via the putative "retrograde messenger" nitric oxide (NO has been hypothesized to serve as a critical link between functional and structural alterations at pre- and postsynaptic sites. In the present study, we show that auditory Pavlovian fear conditioning is associated with significant and long-lasting increases in the expression of the postsynaptically-localized protein GluR1 and the presynaptically-localized proteins synaptophysin and synapsin in the lateral amygdala (LA within 24 hrs following training. Further, we show that rats given intra-LA infusion of either the NR2B-selective antagonist Ifenprodil, the NOS inhibitor 7-Ni, or the PKG inhibitor Rp-8-Br-PET-cGMPS exhibit significant decreases in training-induced expression of GluR1, synaptophysin, and synapsin immunoreactivity in the LA, while those rats infused with the PKG activator 8-Br-cGMP exhibit a significant increase in these proteins in the LA. In contrast, rats given intra-LA infusion of the NO scavenger c-PTIO exhibit a significant decrease in synapsin and synaptophysin expression in the LA, but no significant impairment in the expression of GluR1. Finally, we show that intra-LA infusions of the ROCK inhibitor Y-27632 or the CaMKII inhibitor KN-93 impair training-induced expression of GluR1, synapsin, and synaptophysin in the LA. These findings suggest that the NO-cGMP-PKG, Rho/ROCK, and CaMKII signaling pathways regulate fear memory consolidation, in part, by promoting both pre- and post-synaptic alterations at LA synapses. They further suggest that synaptic plasticity in the LA during auditory fear conditioning promotes alterations at presynaptic sites via NO-driven "retrograde signaling".

  6. Alterations in Red Blood Cell Functionality Induced by an Indole Scaffold Containing a Y-Iminodiketo Moiety: Potential Antiproliferative Conditions

    Directory of Open Access Journals (Sweden)

    Angela Scala

    2016-01-01

    Full Text Available We have recently proposed a new erythrocyte-based model of study to predict the antiproliferative effects of selected heterocyclic scaffolds. Starting from the metabolic similarity between erythrocytes and cancer cells, we have demonstrated how the metabolic derangement induced by an indolone-based compound (DPIT could be related to its antiproliferative effects. In order to prove the validity of our biochemical approach, in the present study the effects on erythrocyte functionality of its chemical precursor (PID, whose synthesis we reported, were investigated. The influence of the tested compound on band 3 protein (B3, oxidative state, ATP efflux, caspase 3, metabolism, intracellular pH, and Ca2+ homeostasis has been evaluated. PID crosses the membrane localizing into the cytosol, increases anion exchange, induces direct caspase activation, shifts the erythrocytes towards an oxidative state, and releases less ATP than in normal conditions. Analysis of phosphatidylserine externalization shows that PID slightly induces apoptosis. Our findings indicate that, due to its unique features, erythrocyte responses to exogenous molecular stimuli can be fruitfully correlated at structurally more complex cells, such as cancer cells. Overall, our work indicates that erythrocyte is a powerful study tool to elucidate the biochemical/biological effects of selected heterocycles opening considerable perspectives in the field of drug discovery.

  7. Alterations in Red Blood Cell Functionality Induced by an Indole Scaffold Containing a Y-Iminodiketo Moiety: Potential Antiproliferative Conditions

    Science.gov (United States)

    Scala, Angela; Ficarra, Silvana; Russo, Annamaria; Giunta, Elena; Galtieri, Antonio; Tellone, Ester

    2016-01-01

    We have recently proposed a new erythrocyte-based model of study to predict the antiproliferative effects of selected heterocyclic scaffolds. Starting from the metabolic similarity between erythrocytes and cancer cells, we have demonstrated how the metabolic derangement induced by an indolone-based compound (DPIT) could be related to its antiproliferative effects. In order to prove the validity of our biochemical approach, in the present study the effects on erythrocyte functionality of its chemical precursor (PID), whose synthesis we reported, were investigated. The influence of the tested compound on band 3 protein (B3), oxidative state, ATP efflux, caspase 3, metabolism, intracellular pH, and Ca2+ homeostasis has been evaluated. PID crosses the membrane localizing into the cytosol, increases anion exchange, induces direct caspase activation, shifts the erythrocytes towards an oxidative state, and releases less ATP than in normal conditions. Analysis of phosphatidylserine externalization shows that PID slightly induces apoptosis. Our findings indicate that, due to its unique features, erythrocyte responses to exogenous molecular stimuli can be fruitfully correlated at structurally more complex cells, such as cancer cells. Overall, our work indicates that erythrocyte is a powerful study tool to elucidate the biochemical/biological effects of selected heterocycles opening considerable perspectives in the field of drug discovery. PMID:27651854

  8. Effects of nutritional and ambient oxygen condition on biofilm formation in Mycobacterium avium subsp. hominissuis via altered glycolipid expression

    Science.gov (United States)

    Totani, Takahiro; Nishiuchi, Yukiko; Tateishi, Yoshitaka; Yoshida, Yutaka; Kitanaka, Hiromi; Niki, Mamiko; Kaneko, Yukihiro; Matsumoto, Sohkichi

    2017-01-01

    Mycobacterium avium subsp. hominissuis (MAH) is the major causative agent of nontuberculous mycobacteriosis, the representative case of environment-related infectious diseases the incidence of which is increasing in industrialized countries. MAH is found in biofilm in drinking water distribution system and residential environments. We investigated the effect of gaseous and nutritional conditions, and the role of glycopeptidolipids (GPLs) on biofilm-like pellicle formation in MAH. Pellicle formation was observed under 5% oxygen in Middlebrook 7H9 broth containing 0.2% glycerol and 10% albumin-dextrose-catalase enrichment but not under normoxia or in nutrient-poor media. An analysis of 17 environmental isolates revealed that hypoxia (5% oxygen) preferentially enhanced pellicle formation both in plastic plates and in glass tubes, compared with hypercapnia (5% carbon dioxide). Wild-type strains (WT) developed much thicker pellicles than GPL-deficient rough mutants (RM). WT bacterial cells distributed randomly and individually in contrast to that RM cells positioned linearly in a definite order. Exogenous supplementation of GPLs thickened the pellicles of RM, resulting in a similar morphological pattern to WT. These data suggest a significant implication of eutrophication and hypoxia in biofilm-like pellicle formation, and a functional role of GPLs on development of pellicles in MAH. PMID:28155911

  9. Improvement of fermentation ability under baking-associated stress conditions by altering the POG1 gene expression in baker's yeast.

    Science.gov (United States)

    Sasano, Yu; Haitani, Yutaka; Hashida, Keisuke; Oshiro, Satoshi; Shima, Jun; Takagi, Hiroshi

    2013-08-01

    During the bread-making process, yeast cells are exposed to many types of baking-associated stress. There is thus a demand within the baking industry for yeast strains with high fermentation abilities under these stress conditions. The POG1 gene, encoding a putative transcription factor involved in cell cycle regulation, is a multicopy suppressor of the yeast Saccharomyces cerevisiae E3 ubiquitin ligase Rsp5 mutant. The pog1 mutant is sensitive to various stresses. Our results suggested that the POG1 gene is involved in stress tolerance in yeast cells. In this study, we showed that overexpression of the POG1 gene in baker's yeast conferred increased fermentation ability in high-sucrose-containing dough, which is used for sweet dough baking. Furthermore, deletion of the POG1 gene drastically increased the fermentation ability in bread dough after freeze-thaw stress, which would be a useful characteristic for frozen dough baking. Thus, the engineering of yeast strains to control the POG1 gene expression level would be a novel method for molecular breeding of baker's yeast.

  10. Alteration of Drosophila life span using conditional, tissue-specific expression of transgenes triggered by doxycyline or RU486/Mifepristone.

    Science.gov (United States)

    Ford, Daniel; Hoe, Nicholas; Landis, Gary N; Tozer, Kevin; Luu, Allan; Bhole, Deepak; Badrinath, Ananth; Tower, John

    2007-06-01

    The conditional systems Tet-on and Geneswitch were compared and optimized for the tissue-specific expression of transgenes and manipulation of life span in adult Drosophila. Two versions of Tet-on system reverse-tetracycline-Trans-Activator (rtTA) were compared: the original rtTA, and rtTAM2-alt containing mutations designed to optimize regulation and expression. The rtTAM2-alt version gave less leaky expression of target constructs in the absence of doxycyline, however the absolute level of expression that could be achieved was less than that produced by rtTA, in contrast to a previous report. Existing UAS-rtTAM2-alt insertions were re-balanced, and combined with several tissue-general and tissue-specific GAL4 driver lines to yield tissue-specific, doxycyline-inducible transgene expression over three orders of magnitude. The Geneswitch (GS) system also had low background, but the absolute level of expression was low relative to Tet-on. Consequently, actin5C-GS multi-insert chromosomes were generated and higher-level expression was achieved without increased background. Moderate level over-expression of MnSOD has beneficial effects on life span. Here high-level over-expression of MnSOD was found to have toxic effects. In contrast, motor-neuron-specific over-expression of MnSOD had no detectable effect on life span. The results suggest that motor-neuron tissue is not the essential tissue for either MnSOD induced longevity or toxicity in adult males.

  11. Retention models for programmed gas chromatography.

    Science.gov (United States)

    Castello, G; Moretti, P; Vezzani, S

    2009-03-06

    The models proposed by many authors for the prediction of retention times and temperatures, peak widths, retention indices and separation numbers in programmed temperature and pressure gas chromatography by starting from preliminary measurements of the retention in isothermal and isobaric conditions are reviewed. Several articles showing the correlation between retention data and thermodynamic parameters and the determination of the optimum programming rate are reported. The columns of different polarity used for the experimental measurement and the main equations, mathematical models and calculation procedures are listed. An empirical approach was used in the early models, followed by the application of thermodynamic considerations, iterative calculation procedures and statistical methods, based on increased computing power now available. Multiple column arrangements, simultaneous temperature and pressure programming, applications of two-dimensional and fast chromatography are summarised.

  12. Drug Retention Times

    Energy Technology Data Exchange (ETDEWEB)

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user.

  13. Drug Retention Times

    Energy Technology Data Exchange (ETDEWEB)

    Center for Human Reliability Studies

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user

  14. Liquid Effluent Retention Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Liquid Effluent Retention Facility (LERF) is located in the central part of the Hanford Site. LERF is permitted by the State of Washington and has three liquid...

  15. Post-operative urinary retention in a general surgical population

    DEFF Research Database (Denmark)

    Dreijer, Bjørn; Møller, Morten H; Bartholdy, Jens

    2011-01-01

    Post-operative urine retention is a frequent and serious complication. The aims of this study were to evaluate the prevalence of post-operative urinary retention in a general surgical population and to identify the perioperative risk factors for developing this condition.......Post-operative urine retention is a frequent and serious complication. The aims of this study were to evaluate the prevalence of post-operative urinary retention in a general surgical population and to identify the perioperative risk factors for developing this condition....

  16. The Genetic Absence Epilepsy Rats from Strasbourg model of absence epilepsy exhibits alterations in fear conditioning and latent inhibition consistent with psychiatric comorbidities in humans.

    Science.gov (United States)

    Marks, Wendie N; Cavanagh, Mary E; Greba, Quentin; Cain, Stuart M; Snutch, Terrance P; Howland, John G

    2016-01-01

    Behavioural, neurological, and genetic similarities exist in epilepsies, their psychiatric comorbidities, and various psychiatric illnesses, suggesting common aetiological factors. Rodent models of epilepsy are used to characterize the comorbid symptoms apparent in epilepsy and their neurobiological mechanisms. The present study was designed to assess Pavlovian fear conditioning and latent inhibition in a polygenetic rat model of absence epilepsy, i.e. Genetic Absence Epilepsy Rats from Strasbourg (GAERS) and the non-epileptic control (NEC) strain. Electrophysiological recordings confirmed the presence of spike-wave discharges in young adult GAERS but not NEC rats. A series of behavioural tests designed to assess anxiety-like behaviour (elevated plus maze, open field, acoustic startle response) and cognition (Pavlovian conditioning and latent inhibition) was subsequently conducted on male and female offspring. Results showed that GAERS exhibited significantly higher anxiety-like behaviour, a characteristic reported previously. In addition, using two protocols that differed in shock intensity, we found that both sexes of GAERS displayed exaggerated cued and contextual Pavlovian fear conditioning and impaired fear extinction. Fear reinstatement to the conditioned stimuli following unsignalled footshocks did not differ between the strains. Male GAERS also showed impaired latent inhibition in a paradigm using Pavlovian fear conditioning, suggesting that they may have altered attention, particularly related to previously irrelevant stimuli in the environment. Neither the female GAERS nor NEC rats showed evidence of latent inhibition in our paradigm. Together, the results suggest that GAERS may be a particularly useful model for assessing therapeutics designed to improve the emotional and cognitive disturbances associated with absence epilepsy.

  17. Radionuclide Retention in Concrete Wasteforms

    Energy Technology Data Exchange (ETDEWEB)

    Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.; Cordova, Elsa A.

    2012-09-24

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  18. Meningitis retention syndrome

    Directory of Open Access Journals (Sweden)

    Abhishek Krishna

    2012-04-01

    Full Text Available A 50-year-old Caucasian woman presented with signs and symptoms of meningitis preceded by a 3 day history of flu-like symptoms and progressive difficulty with urination. Cerebrospinal Fluid (CSF analysis was consistent with aseptic meningitis. She was found to have a significant urinary retention secondary to atonic bladder. MRI of the brain and spine were normal and CSF-PCR (polymerase chain reaction was positive for HSV-2. Urinary retention in the context of meningitis and CSF pleocytosis is known as Meningitis Retention Syndrome (MRS. MRS is a rare but important complication of meningitis most commonly associated with HSV-2. Involvement of central pathways may have a role in the pathogenesis of MRS but this is poorly documented. MRS is different from Elsberg syndrome wherein patients display features of lumbosacral polyradiculitis or radiculomyelitis. Early treatment with antiviral therapy was associated with a favorable outcome in our patient.

  19. Conditions of Formation of Secondary Quartz in Hydrothermally Altered, Subsurface Dacite beneath the Deep-Sea PACMANUS Hydrothermal Field, Manus Basin, Papua New Guinea

    Science.gov (United States)

    Vanko, D. A.; Wicker, S. G.; Binns, R. A.

    2006-05-01

    New fluid inclusion (FI) data from secondary quartz within the altered felsic rocks underlying the PACMANUS hydrothermal field provide additional constraints on the thermal conditions and fluid salinities accompanying hydrothermal alteration. PACMANUS, at a water depth of about 1650 to 1700 m on the summit of the neovolcanic Pual Ridge in the eastern part of the Manus backarc basin, is an active seafloor system situated in a felsic volcanic setting at a convergent plate boundary. Two sites of active venting - Roman Ruins, with high-temperature (220-276° C) sulfide chimneys, and Snowcap, which is an area of lower-temperature (6- 65° C) diffuse flow - were cored during Ocean Drilling Program Leg 193. Drilling reached sub-seafloor depths of 387 m at Snowcap and 206 m at Roman Ruins. At both Snowcap and Roman Ruins, fresh dacite/rhyodacite is underlain by highly to completely altered rocks with clays (illite, illite-smectite, chlorite, and mixed layer clays), disseminated pyrite, silica and late stage anhydrite. At shallow depths the silica is mostly cristobalite, whereas quartz is the polymorph at depth. Secondary quartz occurs in amygdules, alone or with accessory anhydrite and pyrite; in cm-scale granular nodules; and as tiny grains forming an open mosaic with interstitial clays and pore space. Scarce FI in secondary quartz are small (10-20μ), irregular, and contain liquid (L) plus vapor. Only a few are arrayed along healed fractures, and most are interpreted as primary. FI from Snowcap homogenize to L between 290° C and 390° C. Ice melting temperatures vary between about -10° C and -0.4° C, with most ice melting near -2.0° C. Thus, while most FI have near-seawater salinities, a significant number are much more saline, while others are much less saline, approaching fresh water. FI from Roman Ruins homogenize between 257° C and 370° C, and ice melting temperatures vary from about -14° C to -1.2° C. These data are best explained if the hydrothermal

  20. Adolescent social defeat induced alterations in anxious behavior and cognitive flexibility in adult mice: effects of developmental stage and social condition

    Directory of Open Access Journals (Sweden)

    Fang Zhang

    2016-07-01

    Full Text Available Negative social experiences during adolescence increase the risk of psychiatric disorders in adulthood. Using resident-intruder stress, the present study aimed to investigate the effects of adolescent social defeat on emotional and cognitive symptoms associated with psychiatric disorders during adulthood and the effects of the developmental stage and social condition on this process. In experiment 1, animals were exposed to social defeat or manipulation for 10 days during early adolescence (EA, PND 28-37, late adolescence (LA, PND 38-47, and adulthood (ADULT, PND 70-79 and then singly housed until the behavioral tests. Behaviors, including social avoidance of the defeat context and cortically mediated cognitive flexibility in an attentional set-shifting task (AST, were assessed during the week following stress or after 6 weeks during adulthood. We determined that social defeat induced significant and continuous social avoidance across age groups at both time points. The mice that experienced social defeat during adulthood exhibited short-term impairments in reversal learning on the AST that dissipated after 6 weeks. In contrast, social defeat during EA but not LA induced a delayed deficit in extra-dimensional set-shifting in adulthood but not during adolescence. In experiment 2, we further examined the effects of social condition (isolation or social housing after stress on the alterations induced by social defeat during EA in adult mice. The adult mice that had experienced stress during EA exhibited social avoidance similar to the avoidance identified in experiment 1 regardless of the isolation or social housing after the stress. However, social housing after the stress ameliorated the cognitive flexibility deficits induced by early adolescent social defeat in the adult mice, and the social condition had no effect on cognitive function. These findings suggest that the effects of social defeat on emotion and cognitive function are differentially

  1. General Reviews of Vocabulary Retention

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yuan

    2013-01-01

    This paper will try to review two important theories (repletion and retrieval) which are crucial for vocabulary retention. These two methods are well connected and each of them cannot lead to successful vocabulary retention without sensible utilization of the other.

  2. phosphorus retention data and metadata

    Data.gov (United States)

    U.S. Environmental Protection Agency — phosphorus retention in wetlands data and metadata. This dataset is associated with the following publication: Lane , C., and B. Autrey. Phosphorus retention of...

  3. Soil Water Retention Curve

    Science.gov (United States)

    Johnson, L. E.; Kim, J.; Cifelli, R.; Chandra, C. V.

    2016-12-01

    Potential water retention, S, is one of parameters commonly used in hydrologic modeling for soil moisture accounting. Physically, S indicates total amount of water which can be stored in soil and is expressed in units of depth. S can be represented as a change of soil moisture content and in this context is commonly used to estimate direct runoff, especially in the Soil Conservation Service (SCS) curve number (CN) method. Generally, the lumped and the distributed hydrologic models can easily use the SCS-CN method to estimate direct runoff. Changes in potential water retention have been used in previous SCS-CN studies; however, these studies have focused on long-term hydrologic simulations where S is allowed to vary at the daily time scale. While useful for hydrologic events that span multiple days, the resolution is too coarse for short-term applications such as flash flood events where S may not recover its full potential. In this study, a new method for estimating a time-variable potential water retention at hourly time-scales is presented. The methodology is applied for the Napa River basin, California. The streamflow gage at St Helena, located in the upper reaches of the basin, is used as the control gage site to evaluate the model performance as it is has minimal influences by reservoirs and diversions. Rainfall events from 2011 to 2012 are used for estimating the event-based SCS CN to transfer to S. As a result, we have derived the potential water retention curve and it is classified into three sections depending on the relative change in S. The first is a negative slope section arising from the difference in the rate of moving water through the soil column, the second is a zero change section representing the initial recovery the potential water retention, and the third is a positive change section representing the full recovery of the potential water retention. Also, we found that the soil water moving has traffic jam within 24 hours after finished first

  4. Enhancing retention of partial dentures using elastomeric retention rings

    Directory of Open Access Journals (Sweden)

    Kakkirala Revathi

    2015-01-01

    Full Text Available This report presents an alternative method for the retention of partial dentures that relies on the engagement of tooth undercuts by a lining material. The lab procedures are also presented. A new maxillary and mandibular acrylic partial dentures were fabricated using elastomeric retention technique for a partially dentate patient. A partially dentate man reported difficulty in retaining his upper removable partial denture (RPD. The maxillary RPD was designed utilizing elastomeric retention technique. During follow-up, it was necessary to replace the retention rings due to wear. The replacement of the retention rings, in this case, was done through a chairside reline technique. Elastomeric retention technique provides exceptionally good retention can be indicated to stabilize, cushion, splint periodontally involved teeth, no enough undercut for clasps, eliminate extractions, single or isolated teeth.

  5. Selective Surface Modification on Lubricant Retention

    Science.gov (United States)

    Jiang, Yu; Suvanto, Mika; Pakkanen, Tapani A.

    2016-11-01

    While surface patterns are effective in improving tribological properties, nevertheless they alter the surface wettability, which will in turn affect the surface-lubricant interactions. When there is a shortage of lubricant on a patterned surface, the lubricant stored inside the cavities will be extracted to compensate the surface lubricant dissipation. Additionally, the lubricant retention effect provided by the cavities is competing with the release of the lubricant. With weak surface-lubricant interaction, the retention is limited. Therefore, the lubrication will have a sudden failure, giving a dramatic transition to abrasive wear. To improve the performance of polar lubricants on hydrophobic polymer surfaces, both topographical and selective surface modifications were incorporated on injection molded polypropylene surfaces. Distinctive lubrication improvement was observed when the surface structure density for the lubricant storage was high, and the release of the lubricant was controlled by the interaction with the selectively modified surfaces.

  6. Retention performance of green roofs in three different climate regions

    Science.gov (United States)

    Sims, Andrew W.; Robinson, Clare E.; Smart, Charles C.; Voogt, James A.; Hay, Geoffrey J.; Lundholm, Jeremey T.; Powers, Brandon; O'Carroll, Denis M.

    2016-11-01

    Green roofs are becoming increasingly popular for moderating stormwater runoff in urban areas. This study investigated the impact different climates have on the retention performance of identical green roofs installed in London Ontario (humid continental), Calgary Alberta (semi-arid, continental), and Halifax Nova Scotia (humid, maritime). Drier climates were found to have greater percent cumulative stormwater retention with Calgary (67%) having significantly better percent retention than both London (48%) and Halifax (34%). However, over the same study period the green roof in London retained the greatest depth of stormwater (598 mm), followed by the green roof in Halifax (471 mm) and then Calgary (411 mm). The impact of climate was largest for medium sized storms where the antecedent moisture condition (AMC) at the beginning of a rainfall event governs retention performance. Importantly AMC was a very good predictor of stormwater retention, with similar retention at all three sites for a given AMC, emphasizing that AMC is a relevant indicator of retention performance in any climate. For large rainfall events (i.e., >45 mm) green roof average retention ranged between 16% and 29% in all cities. Overall, drier climates have superior retention due to lower AMC in the media. However, moderate and wet climates still provide substantial total volume reduction benefits.

  7. Impact of phosphorus control measures on in-river phosphorus retention associated with point source pollution

    Directory of Open Access Journals (Sweden)

    B. O. L. Demars

    2005-01-01

    Full Text Available In-river phosphorus retention alters the quantity and timings of phosphorus delivery to downstream aquatic systems. Many intensive studies of in-river phosphorus retention have been carried out but generally on a short time scale (2-4 years. In this paper, monthly water quality data, collected by the Environment Agency of England and Wales over 12 years (1990-2001, were used to model daily phosphorus fluxes and monthly in-river phosphorus retention in the lowland calcareous River Wensum, Norfolk, UK. The effectiveness of phosphorus stripping at two major sewage treatment works was quantified over different hydrological conditions. The model explained 78% and 88% of the observed variance before and after phosphorus control, respectively. During relatively dry years, there was no net export of phosphorus from the catchment. High retention of phosphorus occurred, particularly during the summer months, which was not compensated for, by subsequent higher flow events. The critical discharge (Q above which net remobilisation would occur, was only reached during few, high flow events Q25-Q13. Phosphorus removal from the effluent at two major STWs (Sewage Treatment Works reduced the phosphorus catchment mass balance variability by 20-24% under the Q99-Q1. range of flow conditions. Although the absorbing capacity of the catchment against human impact was remarkable, further phosphorus remedial strategies will be necessary to prevent downstream risks of eutrophication occuring independently of the unpredictable variability in weather conditions.

  8. Mouse social stress induces increased fear conditioning, helplessness and fatigue to physical challenge together with markers of altered immune and dopamine function.

    Science.gov (United States)

    Azzinnari, Damiano; Sigrist, Hannes; Staehli, Simon; Palme, Rupert; Hildebrandt, Tobias; Leparc, German; Hengerer, Bastian; Seifritz, Erich; Pryce, Christopher R

    2014-10-01

    In neuropsychiatry, animal studies demonstrating causal effects of environmental manipulations relevant to human aetiology on behaviours relevant to human psychopathologies are valuable. Such valid models can improve understanding of aetio-pathophysiology and preclinical discovery and development of new treatments. In depression, specific uncontrollable stressful life events are major aetiological factors, and subsequent generalized increases in fearfulness, helplessness and fatigue are core symptoms or features. Here we exposed adult male C57BL/6 mice to 15-day psychosocial stress with loss of social control but minimal physical wounding. One cohort was assessed in a 3-day test paradigm of motor activity, fear conditioning and 2-way avoid-escape behaviour on days 16-18, and a second cohort was assessed in a treadmill fatigue paradigm on days 19 and 29, followed by the 3-day paradigm on days 30-32. All tests used a physical aversive stimulus, namely mild, brief electroshocks. Socially stressed mice displayed decreased motor activity, increased fear acquisition, decreased 2-way avoid-escape responding (increased helplessness) and increased fatigue. They also displayed increased plasma TNF and spleen hypertrophy, and adrenal hypertrophy without hyper-corticoidism. In a third cohort, psychosocial stress effects on brain gene expression were assessed using next generation sequencing. Gene expression was altered in pathways of inflammation and G-protein coupled receptors in prefrontal cortex and amygdala; in the latter, expression of genes important in dopamine function were de-regulated including down-regulated Drd2, Adora2a and Darpp-32. This model can be applied to identify targets for treating psychopathologies such as helplessness or fatigue, and to screen compounds/biologics developed to act at these targets. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Pre-exercise hyperhydration-induced bodyweight gain does not alter prolonged treadmill running time-trial performance in warm ambient conditions.

    Science.gov (United States)

    Gigou, Pierre-Yves; Dion, Tommy; Asselin, Audrey; Berrigan, Felix; Goulet, Eric D B

    2012-08-01

    This study compared the effect of pre-exercise hyperhydration (PEH) and pre-exercise euhydration (PEE) upon treadmill running time-trial (TT) performance in the heat. Six highly trained runners or triathletes underwent two 18 km TT runs (~28 °C, 25%-30% RH) on a motorized treadmill, in a randomized, crossover fashion, while being euhydrated or after hyperhydration with 26 mL/kg bodyweight (BW) of a 130 mmol/L sodium solution. Subjects then ran four successive 4.5 km blocks alternating between 2.5 km at 1% and 2 km at 6% gradient, while drinking a total of 7 mL/kg BW of a 6% sports drink solution (Gatorade, USA). PEH increased BW by 1.00 ± 0.34 kg (P < 0.01) and, compared with PEE, reduced BW loss from 3.1% ± 0.3% (EUH) to 1.4% ± 0.4% (HYP) (P < 0.01) during exercise. Running TT time did not differ between groups (PEH: 85.6 ± 11.6 min; PEE: 85.3 ± 9.6 min, P = 0.82). Heart rate (5 ± 1 beats/min) and rectal (0.3 ± 0.1 °C) and body (0.2 ± 0.1 °C) temperatures of PEE were higher than those of PEH (P < 0.05). There was no significant difference in abdominal discomfort and perceived exertion or heat stress between groups. Our results suggest that pre-exercise sodium-induced hyperhydration of a magnitude of 1 L does not alter 80-90 min running TT performance under warm conditions in highly-trained runners drinking ~500 mL sports drink during exercise.

  10. Pre-Exercise Hyperhydration-Induced Bodyweight Gain Does Not Alter Prolonged Treadmill Running Time-Trial Performance in Warm Ambient Conditions

    Directory of Open Access Journals (Sweden)

    Eric D. B. Goulet

    2012-08-01

    Full Text Available This study compared the effect of pre-exercise hyperhydration (PEH and pre-exercise euhydration (PEE upon treadmill running time-trial (TT performance in the heat. Six highly trained runners or triathletes underwent two 18 km TT runs (~28 °C, 25%–30% RH on a motorized treadmill, in a randomized, crossover fashion, while being euhydrated or after hyperhydration with 26 mL/kg bodyweight (BW of a 130 mmol/L sodium solution. Subjects then ran four successive 4.5 km blocks alternating between 2.5 km at 1% and 2 km at 6% gradient, while drinking a total of 7 mL/kg BW of a 6% sports drink solution (Gatorade, USA. PEH increased BW by 1.00 ± 0.34 kg (P < 0.01 and, compared with PEE, reduced BW loss from 3.1% ± 0.3% (EUH to 1.4% ± 0.4% (HYP (P < 0.01 during exercise. Running TT time did not differ between groups (PEH: 85.6 ± 11.6 min; PEE: 85.3 ± 9.6 min, P = 0.82. Heart rate (5 ± 1 beats/min and rectal (0.3 ± 0.1 °C and body (0.2 ± 0.1 °C temperatures of PEE were higher than those of PEH (P < 0.05. There was no significant difference in abdominal discomfort and perceived exertion or heat stress between groups. Our results suggest that pre-exercise sodium-induced hyperhydration of a magnitude of 1 L does not alter 80–90 min running TT performance under warm conditions in highly-trained runners drinking ~500 mL sports drink during exercise.

  11. The Effect of Testing on the Retention of Coherent and Incoherent Text Material

    Science.gov (United States)

    de Jonge, Mario; Tabbers, Huib K.; Rikers, Remy M. J. P.

    2015-01-01

    Research has shown that testing during learning can enhance the long-term retention of text material. In two experiments, we investigated the testing effect with a fill-in-the-blank test on the retention of text material. In Experiment 1, using a coherent text, we found no retention benefit of testing compared to a restudy (control) condition. In…

  12. Improved denture retention in patients with retracted tongues.

    Science.gov (United States)

    Lee, Ji-Hua; Chen, Jen-Hao; Lee, Huey-Er; Chang, Hong-Po; Chen, Hong-Sen; Yang, Yi-Hsin; Chou, Tsau-Mau

    2009-08-01

    Patients who wear mandibular dentures and hold their tongues in retracted positions alter the dimensions of the sublingual space and disrupt the peripheral seal that is needed for optimal denture retention. The authors studied whether retention could be improved if patients moved their tongues from a retracted resting position to an ideal resting position. The authors observed and classified the mandibular residual ridge morphologies of 85 participants who wore complete dentures. The authors recorded and compared the retention of the mandibular denture before and after repositioning the tongue to the ideal resting position. When the participants' tongues were in a retracted resting position, the average retention of the mandibular denture was 75.38 gram weight (+/- 81.83 standard deviation [SD]). After participants repositioned their tongues to the ideal resting position, the average retention of the mandibular denture was 118.89 gw (+/- 93.00 SD), an increase of 57.73 percent. In all morphological classes, when participants held their tongues in the ideal resting position, the average mandibular denture retention increased by 57.73 percent, a statistically significant improvement compared with when participants held their tongues in a retracted resting position. Clinicians are encouraged to evaluate carefully the tongue resting position in all patients who wear dentures, help create reasonable therapeutic expectations by informing patients about the significant effect that tongue position will have on future denture retention and provide helpful neuromuscular training for patients with retracted-tongue habits.

  13. HPLC retention thermodynamics of grape and wine tannins.

    Science.gov (United States)

    Barak, Jennifer A; Kennedy, James A

    2013-05-08

    The effect of grape and wine tannin structure on retention thermodynamics under reversed-phase high-performance liquid chromatography conditions on a polystyrene divinylbenzene column was investigated. On the basis of retention response to temperature, an alternative retention factor was developed to approximate the combined temperature response of the complex, unresolvable tannin mixture. This alternative retention factor was based upon relative tannin peak areas separated by an abrupt change in solvent gradient. Using this alternative retention factor, retention thermodynamics were calculated. Van't Hoff relationships of the natural log of the alternative retention factor against temperature followed Kirchoff's relationship. An inverse quadratic equation was fit to the data, and from this the thermodynamic parameters for tannin retention were calculated. All tannin fractions exhibited exothermic, spontaneous interaction, with enthalpy-entropy compensation observed. Normalizing for tannin size, distinct tannin compositional effects on thermodynamic parameters were observed. The results of this study indicate that HPLC can be valuable for measuring the thermodynamics of tannin interaction with a hydrophobic surface and provides a potentially valuable alternative to calorimetry. Furthermore, the information gathered may provide insight into understanding red wine astringency quality.

  14. In vitro hypoxia-conditioned colon cancer cell lines derived from HCT116 and HT29 exhibit altered apoptosis susceptibility and a more angiogenic profile in vivo

    NARCIS (Netherlands)

    Yao, K; Gietema, JA; Shida, S; Selvakumaran, M; Fonrose, [No Value; Haas, NB; Testa, J; O'Dwyer, PJ

    2005-01-01

    Hypoxia is an important selective force in the clonal evolution of tumours. Through HIF-1 and other transcription factors combined with tumour-specific genetic alterations, hypoxia is a dominant factor in the angiogenic phenotype. Cellular adaptation to hypoxia is an important requirement of tumour

  15. Drug Retention Times

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2007-05-01

    The purpose of this monograph is to provide information on drug retention times in the human body. The information provided is based on plausible illegal drug use activities that might be engaged in by a recreational drug user. Based on anecdotal evidence, most people “party” during extended time away from the work environment. Therefore, the following scenarios were envisioned: (1) a person uses an illicit drug at a party on Saturday night (infrequent user); (2) a person uses a drug one time on Friday night and once again on Saturday night (infrequent user); and (3) a person uses a drug on Friday night, uses a drug twice on Saturday night, and once again on Sunday (frequent user).

  16. Dislocation mechanism of deuterium retention in tungsten under plasma implantation.

    Science.gov (United States)

    Dubinko, V I; Grigorev, P; Bakaev, A; Terentyev, D; van Oost, G; Gao, F; Van Neck, D; Zhurkin, E E

    2014-10-01

    We have developed a new theoretical model for deuterium (D) retention in tungsten-based alloys on the basis of its being trapped at dislocations and transported to the surface via the dislocation network with parameters determined by ab initio calculations. The model is used to explain experimentally observed trends of D retention under sub-threshold implantation, which does not produce stable lattice defects to act as traps for D in conventional models. Saturation of D retention with implantation dose and effects due to alloying of tungsten with, e.g. tantalum, are evaluated, and comparison of the model predictions with experimental observations under high-flux plasma implantation conditions is presented.

  17. 5 CFR 9901.356 - Pay retention.

    Science.gov (United States)

    2010-01-01

    ... retention. (b) Pay retention will be based on the employee's rate of base salary in effect immediately... the range of rates of base salary applicable to the employee's position. (c) Pay retention will be... the 104-week retention limit. (d) Under NSPS, pay retention will be granted when an employee's base...

  18. Toward a Record Retention Policy

    Science.gov (United States)

    Vaughan, Jason

    2007-01-01

    An academic library working group was charged in 2005 to create a records retention schedule and policy applicable to records containing personally identifiable information of library patrons. This group conducted a survey and extensive research, culminating in an adopted library records retention schedule and policy implemented in 2006.

  19. Military Retention. A Comparative Outlook

    Directory of Open Access Journals (Sweden)

    Vasile Sminchise

    2016-06-01

    Full Text Available One of the main goals for human resources management structures and for armed forces leaders is to maintain all necessary personnel, both qualitatively and quantitatively for operational needs or for full required capabilities. The retention of military personnel is essential to keep morale and unit readiness and to reduce the costs for recruiting, training, replacement of manpower. Retention rates depend not only on money or other social measures. The goal for retention is to keep in use the most valuable resource that belongs to an organization: the human beings and their knowledge. The aim pf this paper is to provide a comparative analysis of retention measures in various countries based on Research and Technology Organisation report released in 2007 and, thus, provide more examples of retention measures as far as the Romanian military system is concerned.

  20. Acidic Conditions in the NHE2-/- Mouse Intestine Result in an Altered Mucosa-Associated Bacterial Population with Changes in Mucus Oligosaccharides

    Directory of Open Access Journals (Sweden)

    Melinda A. Engevik

    2013-12-01

    Full Text Available Background: The mechanisms bacteria use to proliferate and alter the normal bacterial composition remain unknown. The ability to link changes in the intestinal micro-environment, such as ion composition and pH, to bacterial proliferation is clinically advantageous for diseases that involve an altered gut microbiota, such as Inflammatory Bowel Disease, obesity and diabetes. In human and mouse intestine, the apical Na+/H+ exchangers NHE2 and NHE3 affect luminal Na+, water, and pH. Loss of NHE2 results in acidic luminal pH. Since acid resistance systems in gram-positive bacteria are well documented, we hypothesize that gram-positive bacteria would increase in representation in the acidic NHE2-/- intestine. Methods: Intestinal ion composition was measured by fame photometry and chloridometry and pH measured electrochemically. DNA extracted from intestinal flushes or from mucosal scrapings was analyzed by qRT-PCR to examine luminal and mucosa-associated bacterial populations. Epithelial mucus oligosaccharide patterns were examined by histology with FIT-C labeled lectins. Results: Although total luminal and mucosa-associated bacteria were unchanged in NHE2-/- intestine, gram-positive bacterial phyla were increased in the mucosa-associated bacterial population in a region-specific manner. The genera Clostridium and Lactobacillus were increased in the cecum and colon which corresponded to changes in NHE2-/- mucus oligosaccharide composition of mannose, N-acetyglucosamine, N-acetygalactosamine and galactose. Conclusions: Together these data indicate that changes in ion transport induce region-specific bacterial changes, which alter host mucus oligosaccharide patterns. These host-bacterial interactions provide a possible mechanism of niche-development and shed insight on how certain groups proliferate in changing environments and maintain their proliferation by altering the host.

  1. Biofilm roughness determines Cryptosporidium parvum retention in environmental biofilms.

    Science.gov (United States)

    DiCesare, E A Wolyniak; Hargreaves, B R; Jellison, K L

    2012-06-01

    The genus Cryptosporidium is a group of waterborne protozoan parasites that have been implicated in significant outbreaks of gastrointestinal infections throughout the world. Biofilms trap these pathogens and can contaminate water supplies through subsequent release. Biofilm microbial assemblages were collected seasonally from three streams in eastern Pennsylvania and used to grow biofilms in laboratory microcosms. Daily oocyst counts in the influx and efflux flow allowed the calculation of daily oocyst retention in the biofilm. Following the removal of oocysts from the influx water, oocyst attachment to the biofilm declined to an equilibrium state within 5 days that was sustained for at least 25 days. Varying the oocyst loading rate for the system showed that biofilm retention could be saturated, suggesting that discrete binding sites determined the maximum number of oocysts retained. Oocyst retention varied seasonally but was consistent across all three sites; however, seasonal oocyst retention was not consistent across years at the same site. No correlation between oocyst attachment and any measured water quality parameter was found. However, oocyst retention was strongly correlated with biofilm surface roughness and roughness varied among seasons and across years. We hypothesize that biofilm roughness and oocyst retention are dependent on environmentally driven changes in the biofilm community rather than directly on water quality conditions. It is important to understand oocyst transport dynamics to reduce risks of human infection. Better understanding of factors controlling biofilm retention of oocysts should improve our understanding of oocyst transport at different scales.

  2. Retention in orthodontics.

    Science.gov (United States)

    Johnston, C D; Littlewood, S J

    2015-02-16

    Retention is necessary following orthodontic treatment to prevent relapse of the final occlusal outcome. Relapse can occur as a result of forces from the periodontal fibres around the teeth which tend to pull the teeth back towards their pre-treatment positions, and also from deflecting occlusal contacts if the final occlusion is less than ideal. Age changes, in the form of ongoing dentofacial growth, as well as changes in the surrounding soft tissues, can also affect the stability of the orthodontic outcome. It is therefore essential that orthodontists, patients and their general dental practitioners understand the importance of wearing retainers after orthodontic treatment. This article will update the reader on the different types of removable and fixed retainers, including their indications, duration of wear, and how they should be managed in order to minimise any unwanted effects on oral health and orthodontic outcomes. The key roles that the general dental practitioner can play in supporting their patients wearing orthodontic retainers are also emphasised.

  3. Data Retention and Anonymity Services

    Science.gov (United States)

    Berthold, Stefan; Böhme, Rainer; Köpsell, Stefan

    The recently introduced legislation on data retention to aid prosecuting cyber-related crime in Europe also affects the achievable security of systems for anonymous communication on the Internet. We argue that data retention requires a review of existing security evaluations against a new class of realistic adversary models. In particular, we present theoretical results and first empirical evidence for intersection attacks by law enforcement authorities. The reference architecture for our study is the anonymity service AN.ON, from which we also collect empirical data. Our adversary model reflects an interpretation of the current implementation of the EC Directive on Data Retention in Germany.

  4. A modelling study of long term green roof retention performance.

    Science.gov (United States)

    Stovin, Virginia; Poë, Simon; Berretta, Christian

    2013-12-15

    This paper outlines the development of a conceptual hydrological flux model for the long term continuous simulation of runoff and drought risk for green roof systems. A green roof's retention capacity depends upon its physical configuration, but it is also strongly influenced by local climatic controls, including the rainfall characteristics and the restoration of retention capacity associated with evapotranspiration during dry weather periods. The model includes a function that links evapotranspiration rates to substrate moisture content, and is validated against observed runoff data. The model's application to typical extensive green roof configurations is demonstrated with reference to four UK locations characterised by contrasting climatic regimes, using 30-year rainfall time-series inputs at hourly simulation time steps. It is shown that retention performance is dependent upon local climatic conditions. Volumetric retention ranges from 0.19 (cool, wet climate) to 0.59 (warm, dry climate). Per event retention is also considered, and it is demonstrated that retention performance decreases significantly when high return period events are considered in isolation. For example, in Sheffield the median per-event retention is 1.00 (many small events), but the median retention for events exceeding a 1 in 1 yr return period threshold is only 0.10. The simulation tool also provides useful information about the likelihood of drought periods, for which irrigation may be required. A sensitivity study suggests that green roofs with reduced moisture-holding capacity and/or low evapotranspiration rates will tend to offer reduced levels of retention, whilst high moisture-holding capacity and low evapotranspiration rates offer the strongest drought resistance.

  5. [Systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography].

    Science.gov (United States)

    Fu, Qing; Wang, Jun; Liang, Tu; Xu, Xiaoyong; Jin, Yu

    2013-11-01

    A systematic evaluation of retention behavior of carbohydrates in hydrophilic interaction liquid chromatography (HILIC) was performed. The influences of mobile phase, stationary phase and buffer salt on the retention of carbohydrates were investigated. According to the results, the retention time of carbohydrates decreased as the proportion of acetonitrile in mobile phase decreased. Increased time of carbohydrates was observed as the concentration of buffer salt in mobile phase increased. The retention behavior of carbohydrates was also affected by organic solvent and HILIC stationary phase. Furthermore, an appropriate retention equation was used in HILIC mode. The retention equation lnk = a + blnC(B) + cC(B) could quantitatively describe the retention factors of carbohydrates of plant origin with good accuracy: the relative error of the predicted time to actual time was less than 0.3%. The evaluation results could provide guidance for carbohydrates to optimize the experimental conditions in HILIC method development especially for carbohydrate separation

  6. Fuzzy indicators for customer retention

    National Research Council Canada - National Science Library

    Valenzuela-Fernández, Leslier; Nicolas, Carolina; Gil-Lafuente, Jaime; Merigó, José M

    2016-01-01

    .... Nevertheless, one cannot ignore the existence of a gap on how to measure this relationship. Following this idea, this study proposes six fuzzy key performance indicators that aims to measure customer retention and loyalty of the portfolio...

  7. 5 CFR 575.315 - Retention incentives for employees likely to leave for a different position in the Federal service.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention incentives for employees likely... Retention incentives for employees likely to leave for a different position in the Federal service. (a... approve a retention incentive for an individual employee under the conditions prescribed in this section...

  8. RAINWATER RETENTION ON THE HEAVILY INDUSTRIALIZED AREAS

    Directory of Open Access Journals (Sweden)

    Bartosz Kaźmierczak

    2016-06-01

    Full Text Available The paper presents the dimensioning of retention reservoirs indicator method regarding to the German DWA-A 117 guideline, recommended for small rainfall catchments (with an area of 200 ha. A comparative calculation of the retention reservoirs overflow useful volume were conducted for 4 variants of catchment development (degree sealing surface varied from 60% to 90%, under the assumed sewage outflow from the tank at the level of the urban basin natural runoff. At given conditions required unit volume of retention reservoirs, from 145.4 m3 to 206.7 m3 for each 1 ha of catchment area were determined. The obtained results confirmed the fact that useful volume of the tanks were decreased, when Blaszczyk’s pattern reliable rainwater streams were used for calculations. Because the DWA-A 117 guideline method should be applied to a small rainfall catchments, it is recommended to verify the hydraulic capacity of dimensioned channels and objects using hydrodynamic simulations at different load of rainfall catchment scenarios, variable in time and space.

  9. Combined pressure-temperature effects on carotenoid retention and bioaccessibility in tomato juice.

    Science.gov (United States)

    Gupta, Rockendra; Kopec, Rachel E; Schwartz, Steven J; Balasubramaniam, V M

    2011-07-27

    This study highlights the changes in lycopene and β-carotene retention in tomato juice subjected to combined pressure-temperature (P-T) treatments ((high-pressure processing (HPP; 500-700 MPa, 30 °C), pressure-assisted thermal processing (PATP; 500-700 MPa, 100 °C), and thermal processing (TP; 0.1 MPa, 100 °C)) for up to 10 min. Processing treatments utilized raw (untreated) and hot break (∼93 °C, 60 s) tomato juice as controls. Changes in bioaccessibility of these carotenoids as a result of processing were also studied. Microscopy was applied to better understand processing-induced microscopic changes. TP did not alter the lycopene content of the tomato juice. HPP and PATP treatments resulted in up to 12% increases in lycopene extractability. all-trans-β-Carotene showed significant degradation (p temperature, and time. Its retention in processed samples varied between 60 and 95% of levels originally present in the control. Regardless of the processing conditions used, lycopene appeared in the form of micelles (lycopene crystals in HPP and PATP processed juice than in thermally processed juice. However, lycopene crystals did appear to be enveloped regardless of the processing conditions used. The processed juice (HPP, PATP, TP) showed significantly higher (p lycopene extractability. However, the in vitro bioaccessibility of carotenoids was not significantly different among the treatments (TP, PATP, HPP) investigated.

  10. Spektrofotometrijska procjena promjene boje zuba dugotrajno izloženih različitim uvjetima = Spectrophotometric evaluation of color alterations of teeth exposed to different conditions in time

    NARCIS (Netherlands)

    Dozic, A.; Zukanovic, A.; Bajsman, A.; Secic, S.; Petaros, A.

    2011-01-01

    Human teeth consist of organic and anorganic tissue components similair to bones. Therefore, it is assumable that the registration of structural changes of teeth color in different enviromental conditions may prove useful within forensic taphonomy field, for example, for verification of burial envir

  11. Conditional ablation of myeloid TNF increases lesion volume after experimental stroke in mice, possibly via altered ERK1/2 signaling

    DEFF Research Database (Denmark)

    Clausen, Bettina Hjelm; Degn, Matilda; Sivasaravanaparan, Mithula

    2016-01-01

    Microglia are activated following cerebral ischemia and increase their production of the neuro- and immunomodulatory cytokine tumor necrosis factor (TNF). To address the function of TNF from this cellular source in focal cerebral ischemia we used TNF conditional knock out mice (LysMcreTNF(fl/fl))...

  12. Effect of the protonophore carbonyl cyanide-p-trifluoromethoxyphenyl-hydrazon on the glutamate release from rat brain nerve terminals under altered gravity conditions.

    Science.gov (United States)

    Borisova, T.; Krisanova, N.

    L-glutamate acts within the mammalian central nervous system as the predominant excitatory neurotransmitter and as a potent neurotoxin The balance between these physiological and pathological actions of glutamate is thought to be kept in check by the rapid removal of the neurotransmitter from the synaptic cleft The majority of uptake is mediated by the high-affinity Na -dependent glutamate transporters Depolarization leads to stimulation of glutamate efflux mediated by reversal of the high-affinity glutamate transporters The effects of the protonophore carbonyl cyanide-p-trifluoromethoxyphenyl-hydrazon FCCP on the glutamate release from isolated nerve terminals rat brain synaptosomes were investigated in control and after centrifuge-induced hypergravity rats were rotated in a long-arm centrifuge at ten-G during one-hour period The treatment of synaptosomes with 1 mu M FCCP during 11 min resulted in the increase in L- 14 C glutamate release by 23 0 pm 2 3 of total accumulated synaptosomal label in control animals and 24 0 pm 2 3 animals subjected to hypergravity FCCP evoked release of L- 14 C glutamate from synaptosomes was not altered in animals exposed to hypergravity as compared to control Glutamate transport is of electrogenic nature and thus depends on the membrane potential The high-KCl stimulated L- 14 C glutamate release in Ca 2 -free media occurred due to reversal of the glutamate transporters Carrier --mediated release of L- 14 C glutamate 6 min slightly increased as a result of

  13. Confounding Impacts of Iron Reduction on Arsenic Retention

    Energy Technology Data Exchange (ETDEWEB)

    Tufano, K.J.; Fendorf, S.

    2009-05-26

    A transition from oxidizing to reducing conditions has long been implicated to increase aqueous As concentrations, for which reductive dissolution of iron (hydr)oxides is commonly implicated as the primary culprit. Confounding our understanding of processes controlling As retention, however, is that reductive transformation of ferrihydrite has recently been shown to promote As retention rather than release. To resolve the role iron phases have in regulating arsenic concentrations, here we examine As desorption from ferrihydrite-coated sands presorbed with As(lll); experiments were performed at circumneutral pH under Fe-reducing conditions with the dissimilatory iron reducing bacterium Shewanella putrefaciens strain CN-32 over extended time periods. We reveal that with the initial phase of iron reduction, ferrihydrite undergoes transformation to secondary phases and increases As(lll) retention (relative to abiotic controls). However, with increased reaction time, cessation of the phase transitions and ensuing reductive dissolution result in prolonged release of As(III) to the aqueous phase. Our results suggest that As(lll) retention during iron reduction is temporally dependent on secondary precipitation of iron phases; during transformation to secondary phases, particularly magnetite, As(lll) retention is enhanced even relative to oxidized systems. However, conditions that retard secondary transformation (more stable iron oxides or limited iron reducing bacterial activity), or prolonged anaerobiosis, will lead to both the dissolution of ferric (hydr)oxides and release of As(lll) to the aqueous phase.

  14. Radionuclide Retention in Concrete Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

    2010-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

  15. Radionuclide Retention in Concrete Wasteforms - FY13

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Michelle MV; Golovich, Elizabeth C.; Wellman, Dawn M.; Crum, Jarrod V.; Lapierre, Robert; Dage, Denomy C.; Parker, Kent E.; Cordova, Elsa A.

    2013-10-15

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of low-level waste and mixed low-level waste, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.

  16. Climate change conditions (elevated CO2 and temperature) and UV-B radiation affect grapevine (Vitis vinifera cv. Tempranillo) leaf carbon assimilation, altering fruit ripening rates.

    Science.gov (United States)

    Martínez-Lüscher, J; Morales, F; Sánchez-Díaz, M; Delrot, S; Aguirreolea, J; Gomès, E; Pascual, I

    2015-07-01

    The increase in grape berry ripening rates associated to climate change is a growing concern for wine makers as it rises the alcohol content of the wine. The present work studied the combined effects of elevated CO2, temperature and UV-B radiation on leaf physiology and berry ripening rates. Three doses of UV-B: 0, 5.98, 9.66 kJm(-2)d(-1), and two CO2-temperature regimes: ambient CO2-24/14 °C (day/night) (current situation) and 700 ppm CO2-28/18 °C (climate change) were imposed to grapevine fruit-bearing cuttings from fruit set to maturity under greenhouse-controlled conditions. Photosynthetic performance was always higher under climate change conditions. High levels of UV-B radiation down regulated carbon fixation rates. A transient recovery took place at veraison, through the accumulation of flavonols and the increase of antioxidant enzyme activities. Interacting effects between UV-B and CO2-temperature regimes were observed for the lipid peroxidation, which suggests that UV-B may contribute to palliate the signs of oxidative damage induced under elevated CO2-temperature. Photosynthetic and ripening rates were correlated. Thereby, the hastening effect of climate change conditions on ripening, associated to higher rates of carbon fixation, was attenuated by UV-B radiation.

  17. Mobile Learning and Student Retention

    Directory of Open Access Journals (Sweden)

    Bharat Inder Fozdar

    2007-06-01

    Full Text Available Student retention in open and distance learning (ODL is comparatively poor to traditional education and, in some contexts, embarrassingly low. Literature on the subject of student retention in ODL indicates that even when interventions are designed and undertaken to improve student retention, they tend to fall short. Moreover, this area has not been well researched. The main aim of our research, therefore, is to better understand and measure students’ attitudes and perceptions towards the effectiveness of mobile learning. Our hope is to determine how this technology can be optimally used to improve student retention at Bachelor of Science programmes at Indira Gandhi National Open University (IGNOU in India. For our research, we used a survey. Results of this survey clearly indicate that offering mobile learning could be one method improving retention of BSc students, by enhancing their teaching/ learning and improving the efficacy of IGNOU’s existing student support system. The biggest advantage of this technology is that it can be used anywhere, anytime. Moreover, as mobile phone usage in India explodes, it offers IGNOU easy access to a larger number of learners. This study is intended to help inform those who are seeking to adopt mobile learning systems with the aim of improving communication and enriching students’ learning experiences in their ODL institutions.

  18. Alteration of microbial communities colonizing leaf litter in a temperate woodland stream by growth of trees under conditions of elevated atmospheric CO2.

    Science.gov (United States)

    Kelly, John J; Bansal, Amit; Winkelman, Jonathan; Janus, Lori R; Hell, Shannon; Wencel, Marie; Belt, Patricia; Kuehn, Kevin A; Rier, Steven T; Tuchman, Nancy C

    2010-08-01

    Elevated atmospheric CO(2) can cause increased carbon fixation and altered foliar chemical composition in a variety of plants, which has the potential to impact forested headwater streams because they are detritus-based ecosystems that rely on leaf litter as their primary source of organic carbon. Fungi and bacteria play key roles in the entry of terrestrial carbon into aquatic food webs, as they decompose leaf litter and serve as a source of nutrition for invertebrate consumers. This study tested the hypothesis that changes in leaf chemistry caused by elevated atmospheric CO(2) would result in changes in the size and composition of microbial communities colonizing leaves in a woodland stream. Three tree species, Populus tremuloides, Salix alba, and Acer saccharum, were grown under ambient (360 ppm) or elevated (720 ppm) CO(2), and their leaves were incubated in a woodland stream. Elevated-CO(2) treatment resulted in significant increases in the phenolic and tannin contents and C/N ratios of leaves. Microbial effects, which occurred only for P. tremuloides leaves, included decreased fungal biomass and decreased bacterial counts. Analysis of fungal and bacterial communities on P. tremuloides leaves via terminal restriction fragment length polymorphism (T-RFLP) and clone library sequencing revealed that fungal community composition was mostly unchanged by the elevated-CO(2) treatment, whereas bacterial communities showed a significant shift in composition and a significant increase in diversity. Specific changes in bacterial communities included increased numbers of alphaproteobacterial and cytophaga-flavobacter-bacteroides (CFB) group sequences and decreased numbers of betaproteobacterial and firmicutes sequences, as well as a pronounced decrease in overall gram-positive bacterial sequences.

  19. Significant alteration of soil bacterial communities and organic carbon decomposition by different long-term fertilization management conditions of extremely low-productivity arable soil in South China.

    Science.gov (United States)

    Xun, Weibing; Zhao, Jun; Xue, Chao; Zhang, Guishan; Ran, Wei; Wang, Boren; Shen, Qirong; Zhang, Ruifu

    2016-06-01

    Different fertilization managements of red soil, a kind of Ferralic Cambisol, strongly affected the soil properties and associated microbial communities. The association of the soil microbial community and functionality with long-term fertilization management in the unique low-productivity red soil ecosystem is important for both soil microbial ecology and agricultural production. Here, 454 pyrosequencing analysis of 16S recombinant ribonucleic acid genes and GeoChip4-NimbleGen-based functional gene analysis were used to study the soil bacterial community composition and functional genes involved in soil organic carbon degradation. Long-term nitrogen-containing chemical fertilization-induced soil acidification and fertility decline and significantly altered the soil bacterial community, whereas long-term organic fertilization and fallow management improved the soil quality and maintained the bacterial diversity. Short-term quicklime remediation of the acidified soils did not change the bacterial communities. Organic fertilization and fallow management supported eutrophic ecosystems, in which copiotrophic taxa increased in relative abundance and have a higher intensity of labile-C-degrading genes. However, long-term nitrogen-containing chemical fertilization treatments supported oligotrophic ecosystems, in which oligotrophic taxa increased in relative abundance and have a higher intensity of recalcitrant-C-degrading genes but a lower intensity of labile-C-degrading genes. Quicklime application increased the relative abundance of copiotrophic taxa and crop production, although these effects were utterly inadequate. This study provides insights into the interaction of soil bacterial communities, soil functionality and long-term fertilization management in the red soil ecosystem; these insights are important for improving the fertility of unique low-productivity red soil.

  20. The effect of sugars on the retention of ethyl butyrate by gellan gels.

    Science.gov (United States)

    Evageliou, Vasiliki; Patsiakou, Anna

    2014-08-15

    The effect of sucrose, glucose and fructose on the retention of ethyl butyrate by low acyl gellan gels was investigated by static headspace gas chromatography. The air/biopolymer partition coefficient (K) and percentage of retention (R%) were determined. When 5 g of sample were left to equilibrate at 37 °C for 24 h, the obtained results were explained in terms of gel rigidity, as increased rigidity resulted in increased aroma retention. Glucose showed the greatest aroma release among the sugars and resulted in either the same or increased aroma release with increasing concentration. Increasing concentrations of fructose and sucrose did not alter aroma release significantly. For 15 g of sample mass, sucrose exhibited the lowest partition coefficient values among the sugars. The two higher sucrose concentrations resulted in decreased coefficient values. For fructose and glucose, aroma retention decreased with increasing concentration. The percentage of retention values were positive for all sugars, throughout their concentration range and for both experiments.

  1. Macro- and microclimate conditions may alter grapevine deacclimation: variation in thermal amplitude in two contrasting wine regions from North and South America

    Science.gov (United States)

    Antivilo, Francisco Gonzalez; Paz, Rosalía Cristina; Keller, Markus; Borgo, Roberto; Tognetti, Jorge; Juñent, Fidel Roig

    2017-07-01

    Low temperature is a limiting factor that affects vineyard distribution globally. The level of cold hardiness acquired during the dormant season by Vitis sp. is crucial for winter survival. Most research published on this topic has been generated beyond 40° N latitude, where daily mean temperatures may attain injurious levels during the dormant season resulting in significant damage to vines and buds. Symptoms of cold injury have been identified in Mendoza (32-35° S latitude), a Southern Hemisphere wine region characterized by a high thermal amplitude, and warm winds during the dormant season. These symptoms have usually been attributed to drought and/or pathogens, but not to rapid deacclimation followed by injurious low temperatures. Because local information on meteorological events as probable causes is scarce, this research was designed to test and study this assumption by comparing macro-, meso-, and microclimatic data from Mendoza, Argentina, and eastern Washington, USA. The goal was to unveil why freezing damage has occurred in both regions, despite the existence of large climatic differences. Because environmental parameters under field conditions may not correspond to data recorded by conventional weather stations, sensors were installed in vineyards for comparison. Microclimatic conditions on grapevines were also evaluated to assess the most vulnerable portions of field-grown grapevines. In order to better understand if it may be possible to modify cold hardiness status in a short period with high thermal amplitude conditions, deacclimation was induced using a thermal treatment. Hence, despite the fact that Mendoza is warmer, and temperatures are not as extreme as in Washington, high daily thermal amplitude might be partially involved in plant deacclimation, leading to a differential cold hardiness response.

  2. Mn2+ alters peroxidase profiles and lignin degradation by the white-rot fungus Pleurotus ostreatus under different nutritional and growth conditions.

    Science.gov (United States)

    Cohen, Roni; Persky, Limor; Hazan-Eitan, Zahit; Yarden, Oded; Hadar, Yitzhak

    2002-01-01

    The white-rot fungus Pleurotus ostreatus produces two types of extracellular peroxidases: manganese-dependent peroxidase (MnP) and versatile peroxidase (VP). The effect of Mn2+ on fungal growth, peroxidase activity profiles, and lignin degradation by P. ostreatus was studied in liquid culture and under solid-state fermentation conditions on perlite, the latter resembling the natural growth conditions of this fungus. The fungus was grown in either a defined asparagine-containing basidiomycete selective medium (BSM) or in a rich peptone medium (PM). Biomass production, as determined by respiration experiments in solid-state fermentation and liquid cultures and fungal growth on Petri dishes, was higher in the PM than in the BSM. Mn2+ affected biomass production only in the PM on Petri dishes. In the nonamended PM, high levels of MnP and VP activity were detected relative to the nonamended BSM. Nevertheless, a higher rate of 14C-lignin mineralization was measured in the Mn2+-amended BSM, as determined during the course of 47 d of fermentation. Mn2+ amendment of the PM increased mineralization rate to that obtained in the Mn2+-amended BSM. The enzyme activity profiles of MnP and VP were studied in the BSM using anion-exchange chromatography. In the nonamended BSM, only minute levels of MnP and VP were detected. On Mn2+ amendment, two MnP isoenzymes (B1 and B2) appeared. Isoenzyme B2 was purified and showed 100% identity with the MnP isoenzyme purified in our previous study from PM-solid-state fermentation (P6). P6 was found to be the dominant isoenzyme in terms of activity level and gene expression compared with the VP isoenzymes. Based on these results, we concluded that Mn2+ plays a key role in lignin degradation under different nutritional and growth conditions, since it is required for the production of MnP in P. ostreatus.

  3. Factors affecting retention of early pregnancy in dairy cattle.

    Science.gov (United States)

    Starbuck, Melanie J; Dailey, Robert A; Inskeep, E Keith

    2004-08-01

    Potential factors affecting retention of pregnancy during weeks 5-9 of gestation were studied in dairy cows and heifers (N = 211) on two farms. Cows were examined by ultrasonography for presence of a viable embryo, and sizes of the corpus luteum (CL) and of follicles > or = 5mm were recorded. Blood samples were taken at each examination and assayed for progesterone and estradiol. Overall pregnancy loss was 11.4%. Cows with two CL did not have greater concentrations of progesterone than cows with one CL and they retained fewer pregnancies (P Embryos that were lost apparently died before CL regression. Retention of pregnancy declined in cows with high body condition and as age of the cow increased. Pregnancy retention was lower in cows bred to one of four frequently-used service sires (P body condition and service sire.

  4. High-fat diet feeding alters metabolic response to fasting/non fasting conditions. Effect on caveolin expression and insulin signalling

    Directory of Open Access Journals (Sweden)

    Martínez J Alfredo

    2011-04-01

    Full Text Available Abstract Background The effect of food intake on caveolin expression in relation to insulin signalling was studied in skeletal muscle and adipocytes from retroperitoneal (RP and subcutaneous (SC adipose tissue, comparing fasted (F to not fasted (NF rats that had been fed a control or high-fat (HF diet for 72 days. Methods Serum glucose was analysed enzymatically and insulin and leptin by ELISA. Caveolins and insulin signalling intermediaries (IR, IRS-1 and 2 and GLUT4 were determined by RT-PCR and western blotting. Caveolin and IR phosphorylation was measured by immunoprecipitation. Data were analysed with Mann-Whitney U test. Results High-fat fed animals showed metabolic alterations and developed obesity and insulin resistance. In skeletal muscle, food intake (NF induced activation of IR and increased expression of IRS-2 in control animals with normal metabolic response. HF animals became overweight, hyperglycaemic, hyperinsulinemic, hyperleptinemic and showed insulin resistance. In skeletal muscle of these animals, food intake (NF also induced IRS-2 expression together with IR, although this was not active. Caveolin 3 expression in this tissue was increased by food intake (NF in animals fed either diet. In RP adipocytes of control animals, food intake (NF decreased IR and IRS-2 expression but increased that of GLUT4. A similar but less intense response was found in SC adipocytes. Food intake (NF did not change caveolin expression in RP adipocytes with either diet, but in SC adipocytes of HF animals a reduction was observed. Food intake (NF decreased caveolin-1 phosphorylation in RP but increased it in SC adipocytes of control animals, whereas it increased caveolin-2 phosphorylation in both types of adipocytes independently of the diet. Conclusions Animals fed a control-diet show a normal response to food intake (NF, with activation of the insulin signalling pathway but without appreciable changes in caveolin expression, except a small increase

  5. Tumor microenvironment conditions alter Akt and Na+/H+ exchanger NHE1 expression in endothelial cells more than hypoxia alone

    DEFF Research Database (Denmark)

    Pedersen, Anna-Kathrine; Mendes Lopes de Melo, Joana; Mørup, Nina

    2017-01-01

    Background Chronic angiogenesis is a hallmark of most tumors and takes place in a hostile tumor microenvironment (TME) characterized by hypoxia, low nutrient and glucose levels, elevated lactate and low pH. Despite this, most studies addressing angiogenic signaling use hypoxia as a proxy for tumor......% hypoxia, low serum, glucose, pH, high lactate) or 1% hypoxia for 24 or 48 h, with or without NHE1 inhibition or siRNA-mediated knockdown. mRNA and protein levels of NHE1, Akt1–3, and downstream effectors were assessed by qPCR and Western blotting, vascular endothelial growth factor (VEGF) release by ELISA...... cells, Akt1 most abundantly. Akt1 protein expression was reduced by TME yet unaffected by hypoxia, while Akt phosphorylation was increased by TME. The Akt loss was partly reversed by MCF-7 human breast cancer cell conditioned medium, suggesting that in vivo, the cancer cell secretome may compensate...

  6. Potential possibilities of water retention in agricultural loess catchments

    Directory of Open Access Journals (Sweden)

    Zubala Tomasz

    2016-09-01

    Full Text Available The growing water deficit and the increased demand for water, as well as economic problems and inadequate spatial planning in many regions indicate a necessity of developing more effective rules of programming and realisation of works concerning the water management in small catchments. The paper presents a sample analysis of the possibilities of increasing water retention in the agricultural loess catchments with periodic streams. The scope of the study included the determination of physical parameters of selected sub-catchments (geometry, soil cover, land use, etc. and of the sources of threat to water resources, resulting from construction and geomorphological conditions. Pre-design assumptions of dammings were developed, taking into account anti-erosion protective measures, and treatments increasing the landscape retention of water were proposed. Creating surface retention objects should be an important source of water in simplified agroecosystems, especially in regions, where productivity to a great extent depends on natural weather conditions. Proper management of the fourth-order loess basin of the Ciemięga River (area of about 150 km2, the presence of 50 lateral valleys could give a temporary reservoir retention reaching 500 thousand m3. Farmers should be encouraged to seek “own water sources” (including the accumulation of water within wasteland, using appropriate economic instruments (tax reliefs for the documented volume of retained water, e.g. in small retention reservoirs.

  7. Pre-Exercise Hyperhydration-Induced Bodyweight Gain Does Not Alter Prolonged Treadmill Running Time-Trial Performance in Warm Ambient Conditions

    Science.gov (United States)

    Gigou, Pierre-Yves; Dion, Tommy; Asselin, Audrey; Berrigan, Felix; Goulet, Eric D. B.

    2012-01-01

    This study compared the effect of pre-exercise hyperhydration (PEH) and pre-exercise euhydration (PEE) upon treadmill running time-trial (TT) performance in the heat. Six highly trained runners or triathletes underwent two 18 km TT runs (~28 °C, 25%–30% RH) on a motorized treadmill, in a randomized, crossover fashion, while being euhydrated or after hyperhydration with 26 mL/kg bodyweight (BW) of a 130 mmol/L sodium solution. Subjects then ran four successive 4.5 km blocks alternating between 2.5 km at 1% and 2 km at 6% gradient, while drinking a total of 7 mL/kg BW of a 6% sports drink solution (Gatorade, USA). PEH increased BW by 1.00 ± 0.34 kg (P Running TT time did not differ between groups (PEH: 85.6 ± 11.6 min; PEE: 85.3 ± 9.6 min, P = 0.82). Heart rate (5 ± 1 beats/min) and rectal (0.3 ± 0.1 °C) and body (0.2 ± 0.1 °C) temperatures of PEE were higher than those of PEH (P running TT performance under warm conditions in highly-trained runners drinking ~500 mL sports drink during exercise. PMID:23016126

  8. Regulation of crayfish, Orconectes virilis, tail muscle lactate dehydrogenase (LDH) in response to anoxic conditions is associated with alterations in phosphorylation patterns.

    Science.gov (United States)

    Green, Stuart R; Storey, Kenneth B

    2016-12-01

    Lactate dehydrogenase (LDH), the terminal enzyme of anaerobic glycolysis, has a crucial role in sustaining ATP production by glycolysis during periods of anoxia via regenerating NAD(+) through the production of lactate. The present study examined the effects of prolonged (20h) anoxic submergence on LDH from the tail muscle of an anoxia-tolerant crayfish (Orconectes virilis). LDH was purified to homogeneity from tail muscle of both aerobic control and anoxic crayfish in a three step process. Analysis of the kinetic parameters and the stability of LDH showed that the Vmax in the pyruvate-reducing direction was significantly higher for the enzyme from anoxic crayfish whereas in the lactate-oxidizing direction the Vmax was significantly higher for the control enzyme. Differential scanning fluorimetry was used to assess thermal unfolding of crayfish LDH. The results showed that the enzyme from control muscle had a significantly higher melting temperature (greater thermal stability) than the anoxic enzyme form, suggesting that there was a structural difference between the two enzyme forms. Immunoblotting of purified LDH implicated post-translational modification as the reason for this difference; purified LDH from aerobic control crayfish showed significantly higher amounts of serine/threonine phosphorylation than did the anoxic enzyme form. This study provides evidence for anoxia-induced modifications of crayfish muscle LDH that may contribute significantly to modulating enzyme function under anoxic conditions.

  9. Retention of contaminants in constructed and semi-natural wetland soils in urban river systems

    Science.gov (United States)

    Kalinski, Kira; Gröngröft, Alexander; Eschenbach, Annette

    2017-04-01

    The retention of floods is one of the most relevant ecosystem function of urban floodplains, which is often improved by the construction of retention ponds and other water management measures. Retention ponds are connected to the river in a direct or a parallel arrangement and can be constructed as dry or wet retention pond under normal run-off conditions. Further important ecosystem functions provided by the floodplains soils are carbon sequestration, nutrient and contaminant regulation and recreation. However, with ongoing urbanization these ecosystem functions are significantly endangered. In our study we analyze the soil-based ecosystem functions of two river catchments in the City of Hamburg. The presentation will focus on the retention of contaminants in soils and sediments of eleven retention ponds within one catchment. The amount and concentrations of contaminants will be analyzed for controlling factors like grain size distribution, land-use within the headwaters and others.

  10. [Acute retention of urine secondary to a congenital diverticulum of the bladder].

    Science.gov (United States)

    Azahouani, A; Hida, M; Lasseri, A; Lahfaoui, M; Zaari, N; Belahcen, M; Elazzouzi, D; Benhaddou, H

    2016-10-01

    Bladder diverticula in children are mostly congenital, frequently associated with vesicoureteral reflux. Their positive diagnosis is based primarily on retrograde urethrocystography. One complication of this condition is acute urinary retention. We report the case of a 4-month-old infant who presented acute retention of urine secondary to bilateral congenital bladder diverticulum and review the literature on this subject.

  11. Basic Retention Mechanisms

    DEFF Research Database (Denmark)

    Jensen, Bror Skytte; Jensen, H.

    1986-01-01

    . The data for kaolinite were similarly interpreted as adsorption of hydroxylated complexes of the polyvalent cations, a mechanism which has previously been suggested for the adsorption of heavy metals onto muds, sludges and organic debris. In the case of kaolinite, indications of additional reactions like......The effect of multiple cation competition on the adsorption of Sr onto two synthetic ion-exchange resins, i. e. DOWEX 50W and DOWEX CCR-2, as well as onto the clay mineral, kaolinite has been studied. The results for DOWEX 50W, and under certain experimental conditions also for DOWEX CCR-2 were...... in good agreement with theoretical predictions for multielement ion-exchange taking the limiting effect of ion-exchange capacity into account. In the case of very low cation adsorption, DOWEX CCR-2 showed an unexpected behavior which is interpreted as ion-pair or ion-cluster adsorption of polyvalent ions...

  12. Ab inito based model for subsurface flow and wett-ability alterations at reservoir condition for variation in ionic composition for carbonates

    Science.gov (United States)

    Hara Chakravarty, Krishna; Thomsan, Kaj

    2013-04-01

    free energy profile was also developed for polar hydrocarbon-Metal ion-water complex (CH3COO(-)-M2+-[H2O]n).Herein the two layer model was observed with Ca2+ and Sr2+ while the inner shell was still inconsistent with the 4.2 ( i.e. 3.9 to 4.4 ) Å local energy well model, the outer shell was observed near 6 Å. While with Mg2+ one major shell free energy model was obtained with several minor variations with changing temperature. Here the Ca2+ complex was significantly more stable being the only complex with a negative energy profile around 4.2 Å. Further these observations were together investigated to propose a wett-ability and flow rate model at on the surface described as: Mg2+ + Calcite +(5-6)H2O - -> Mg2+[H2O]5-6- Calcite + eV Calcite- [H2O]4 -Ca2+-CH3COO(-) + eV + SO42-+ (Ca2+,Sr2+) -> Calcite- [H2O] + Calcite- Ca2+- SO42-+ (Ca2+,Sr2+)-(-)OOCCH3 A large part of the work also includes the categorical rejection of many other possible structures, complexes and clusters formations. The model abides to all the experimentally observed points both in field and lab in wett ability alteration, and enhanced oil recovery, and through these energy variation the model categorically explains the effect of temperature on the flow behavior. This model provides a new view to the activity of Mg2+ in surface chemistry for carbonate rock structures in general and can have application in study of erosion, corrosion and other fields as well. This is the first comprehensive mathematical model to extensively explain the low salinity behaviors observed in enhanced oil recovery from a microscopic level to the best of our knowledge.

  13. Maslow's Hierarchy and Student Retention.

    Science.gov (United States)

    Brookman, David M.

    1989-01-01

    Abraham Maslow's hierarchy of needs offers perspective on student motivation and a rationale for college retention programing. Student affairs and faculty interventions addressing student safety needs and engaging students' sense of purpose reinforce persistence. A mentor program is a possible cooperative effort between student personnel and…

  14. Lake retention of manufactured nanoparticles

    NARCIS (Netherlands)

    Koelmans, A.A.; Quik, J.T.K.; Velzeboer, I.

    2015-01-01

    For twenty-five world lakes and three engineered nanoparticles (ENP), lake retention was calculated using a uniformly mixed lake mass balance model. This follows similar approaches traditionally used in water quality management. Lakes were selected such that lake residence times, depths and areal hy

  15. Strategies for improving employee retention.

    Science.gov (United States)

    Verlander, Edward G; Evans, Martin R

    2007-03-28

    This article proposes a solution to the perennial problem of talent retention in the clinical laboratory. It includes the presentation of 12 strategies that may be used to significantly improve institutional identity formation and establishment of the psychological contract that employees form with laboratory management. Identity formation and psychological contracting are deemed as essential in helping reduce employee turnover and increase retention. The 12 conversational strategies may be used as a set of best practices for all employees, but most importantly for new employees, and should be implemented at the critical moment when employees first join the laboratory. This time is referred to as "retention on-boarding"--the period of induction and laboratory orientation. Retention on-boarding involves a dialogue between employees and management that is focused on the psychological, practical, cultural, and political dimensions of the laboratory. It is placed in the context of the modern clinical laboratory, which is faced with employing and managing Generation X knowledge workers. Specific topics and broad content areas of those conversations are outlined.

  16. Lake retention of manufactured nanoparticles

    NARCIS (Netherlands)

    Koelmans, A.A.; Quik, J.T.K.; Velzeboer, I.

    2015-01-01

    For twenty-five world lakes and three engineered nanoparticles (ENP), lake retention was calculated using a uniformly mixed lake mass balance model. This follows similar approaches traditionally used in water quality management. Lakes were selected such that lake residence times, depths and areal hy

  17. Institutionalization of a Retention Model

    Science.gov (United States)

    Davis, E. J.; Campbell, A.

    2006-05-01

    Bowie State University and NASA Goddard Space Flight Center have, for the past 10 years, worked diligently together to enhance the science, mathematics, engineering and technology (SMET) domain. Efforts made, because of a Model Institutions for Excellence (MIE) Award, have changed the landscape of the SMET domain by increasing the retention and graduation rates, the number of students entering graduate and professional schools, and the number of students entering SMET related careers for minorities and women. Several initiatives a Scholarship Program, PRISEM Tutoring Center, Safety-net Program, Research emphasis, Focused Mentoring, a Summer Academy for accepted incoming students, a Bridge Program for students needing assistance being admitted to the University, the RISE Program and the Bowie State Satellite Operations and Control Center (BSOCC) provide the nurturing, mentoring, and opportunities for our students. As a result of efforts made, the retention rate has increase to approximately 80%, the graduation rate has increased 40%, and 85% of the SMET students are now interested or entering graduate and professional schools. Successes that have been documented by various assessment activities have led to the institutionalization of the Retention Model of the MIE Initiative. It is anticipated that University-wide application of the retention model will prove the incentives necessary to obtain similar results as the MIE Initiative.

  18. Maslow's Hierarchy and Student Retention.

    Science.gov (United States)

    Brookman, David M.

    1989-01-01

    Abraham Maslow's hierarchy of needs offers perspective on student motivation and a rationale for college retention programing. Student affairs and faculty interventions addressing student safety needs and engaging students' sense of purpose reinforce persistence. A mentor program is a possible cooperative effort between student personnel and…

  19. Human omental adipose-derived mesenchymal stem cell-conditioned medium alters the proteomic profile of epithelial ovarian cancer cell lines in vitro

    Directory of Open Access Journals (Sweden)

    Zhang YL

    2017-03-01

    Full Text Available Yanling Zhang,1,* Weihong Dong,1,* Junjie Wang,2 Jing Cai,1 Zehua Wang1 1Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 2Department of Obstetrics and Gynecology, Renhe Hospital, China Three Gorges University, Yichang, People’s Republic of China *These authors contributed equally to this work Abstract: Mesenchymal stem cells (MSCs have been reported to participate in the formation of supportive tumor stroma. The abilities of proliferation and invasion of human epithelial ovarian cancer (EOC cells were significantly enhanced when indirectly cocultured with human omental adipose-derived MSCs (O-ADSCs in vitro. However, the underlying mechanisms remain poorly understood. In this study, EOC cells were cultured with conditioned medium (CM from O-ADSCs (O-ADSC, and the effect of O-ADSC CM on the proteomic profile of EOC cells was assessed by two-dimensional gel electrophoresis (2-DE, followed by liquid chromatography and tandem mass spectrometry. The 2-DE assays revealed a global increase in protein expression in the EOC cells treated with CM. Nine proteins were identified from 11 selected protein spots with differential expression after treatment with CM from O-ADSCs. All the nine proteins have been linked to carcinoma and apoptosis, and the migration ability of tumor cells can be regulated by these proteins. Moreover, the upregulation of prohibitin and serine/arginine-rich splicing factor 1 in EOC cells treated with CM was further confirmed by quantitative real-time polymerase chain reaction. These results suggest that O-ADSCs affect the proteomic profile of EOC cells via paracrine mechanism in favor of EOC progression. Keywords: ovarian cancer, mesenchymal stromal cells, mesenchymal stem cells, omentum, proteomic

  20. Phosphorus retention capacity of sediments in Mandovi estuary (Goa)

    Digital Repository Service at National Institute of Oceanography (India)

    Rajagopal, M.D.; Reddy, C.V.G.

    Experiments carried out under controlled conditions to study P retention capacity of sediments indicate that the processes of adsorption and desorption of P are pH dependent. Adsorption of P is maximum (58-99%) at pH 4. Both the exchangeable P...

  1. RETENTION TIME EFFECT ON METAL REMOVAL BY PEAT COLUMNS

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, E

    2007-02-28

    The potential use of a peat bed to treat the H-12 Outfall discharge to bring it to new compliance limits was previously investigated and reported utilizing a 7 hour retention time. The influence of retention time (contact time) of water with peat moss on the removal of copper from the water was investigated under laboratory conditions using vertical flow peat moss columns. Reduction of the necessary retention time has a large influence on the design sizing of any peat bed that would be constructed to treat the H-12 discharge on a full scale basis. Retention times of 5 hours, 3 hours and 1 hour were tested to determine the copper removal by the peat columns using vertical flow. Water samples were collected after 4, 8, 12, and 16 water volumes had passed through the columns and analyzed for a suite of metals, with quantitative emphasis on copper. Laboratory results indicated that copper removal was very high at each of the 3 retention times tested, ranging from 99.6 % removal at 5 and 3 hours to 98.8% removal at 1 hour. All these values are much lower that the new compliance limit for the outfall. The results also indicated that most divalent metals were removed to their normal reporting detection limit for the analytical methods used, including zinc. Lead levels in the H-12 discharge used in this study were below PQL in all samples analyzed. While each of the retention times studied removed copper very well, there were indications that 1 hour is probably too short for an operational, long-term facility. At that retention time, there was about 6% compaction of the peat in the column due to the water velocity, and this may affect long term hydraulic conductivity of the peat bed. At that retention time, copper concentration in the effluent was higher than the other times tested, although still very low. Because of the potential compacting and somewhat reduced removal efficiency at a 1 hour retention time, it would be prudent to design to at least a 3 hour retention

  2. SHEARING AND WATER RETENTION BEHAVIOR OF UNSATURATED LOAM WITH MODELING

    Science.gov (United States)

    Kiyohara, Yukoh; Kazama, Motoki

    Unsaturated triaxial tests were carried out to study deformation behavior, effective stress path and water retention property of consolidated loam during consolidation and shearing processes. Initial matric suction was set as 0, 50, and 90 kPa, and confining pressures (net normal stresses) were set as 100 kPa. Then shearing processes were done under undrained and drained conditions. We clarified the relation between void ratio and Van Genuchten model parameter by using water retention curve. To predict the unsaturated shearing behavior, a modified Cam Clay model considering void ratio dependent Van Genuchten parameter was proposed. Those numerical test results were agreed well with laboratory tests results.

  3. Updating metacognitive control in response to expected retention intervals.

    Science.gov (United States)

    Fiechter, Joshua L; Benjamin, Aaron S

    2016-10-21

    In five experiments, we investigated whether expected retention intervals affect subjects' encoding strategies. In the first four experiments, our subjects studied paired associates consisting of words from the Graduate Record Exam and a synonym. They were told to expect a test on a word pair after either a short or a longer interval. Subjects were tested on most pairs after the expected retention interval. For some pairs, however, subjects were tested after the other retention interval, allowing for a comparison of performance at a given retention interval conditional upon the expected retention interval. No effect of the expected retention interval was found for 1 min versus 4 min (Exp. 1), 30 s versus 3 min (Exp. 2), and 30 s versus 10 min (Exps. 3 and 4), even when subjects were given complete control over the pacing of study items (Exp. 4). However, when the difference between the expected retention intervals was increased massively (10 min vs. 24 h; Exp. 5), subjects remembered more items that they expected to be tested sooner, an effect consistent with the idea that they traded off efforts to remember items for the later test versus items that were about to be tested. Overall, this set of results accords with much of the test-expectancy literature, revealing that subjects are often reluctant to adjust encoding strategies on an item-by-item basis, and when they do, they usually make quantitative, rather than qualitative, adjustments.

  4. Music and Alterity Processes

    Directory of Open Access Journals (Sweden)

    Josep Martí

    2014-10-01

    Full Text Available The concept of alterity constitutes an important issue in anthropological research and, therefore, in the study of musical practices, as well. Without it, we could hardly understand other kinds of music situated in different spaces and time from the observer. In order to effectively approach these musical practices, we have to develop strategies to help us reduce as much as possible that which distorts the vision of the other. However, beyond the strictly epistemological and methodological issues, the study of music cannot ignore the ethical question related to the manner in which Western thought has understood and treated the other: through a hierarchical and stereotypical type of thinking based on the condition of otherness. Throughout the article, different alterity procedures are presented and discussed, such as synecdochization, exoticization, undervaluation, overvaluation, misunderstanding and exclusion. Taking these different alterity strategies into account may help us to better understand how the musical other is constructed, used and ultimately instrumentalized.

  5. APPLICATION OF BORON MODIFIED SILICA SOL ON RETENTION AND DRAINAGE

    Institute of Scientific and Technical Information of China (English)

    JinxiaMa; YuxiuPeng; ZhongzhengLi

    2004-01-01

    In this paper it was studied that these dosage effectsof CPAM, cationic starch,boron modified silica sol(BMS), A12(SO4)3, pH value and electrolyte on theretention and drainage of different microparticulatesystems including CPAM, cationic starch and boronsilica sol. The research results indicated that CPAMhad no good retention when used with boron silicasol. The best retention efficiency was the micropar-ticulate system of CPAM + cationic starch withboron modified silica sol; Secondly was that ofcationic starch with boron modified silica sol; Theworst was that of CPAM with boron modified silicasol. The retention efficiency had no relation with theaddition order between CPAM and cationic starch. Itwas also found that the microparticulate retentionsystem of boron modified silica sol could be used inalum-rosin sizing and in acidity, neutral or alkalinepapermaking conditions. This system also could beused with close circulate water so that it could reducethe water pollution and waste.

  6. APPLICATION OF BORON MODIFIED SILICA SOL ON RETENTION AND DRAINAGE

    Institute of Scientific and Technical Information of China (English)

    Jinxia Ma; Yuxiu Peng; Zhongzheng Li

    2004-01-01

    In this paper it was studied that these dosage effects of CPAM, cationic starch、boron modified silica sol (BMS), Al2(SO4)3, pH value and electrolyte on the retention and drainage of different microparticulate systems including CPAM, cationic starch and boron silica sol. The research results indicated that CPAM had no good retention when used with boron silica sol. The best retention efficiency was the microparticulate system of CPAM + cationic starch with boron modified silica sol; Secondly was that of cationic starch with boron modified silica sol; The worst was that of CPAM with boron modified silica sol. The retention efficiency had no relation with the addition order between CPAM and cationic starch. It was also found that the microparticulate retention system of boron modified silica sol could be used in alum-rosin sizing and in acidity, neutral or alkaline papermaking conditions. This system also could be used with close circulate water so that it could reduce the water pollution and waste.

  7. Designing Online Courses to Promote Student Retention

    Science.gov (United States)

    Dietz-Uhler, Beth; Fisher, Amy; Han, Andrea

    2008-01-01

    Although the issue of student retention is a campus-wide one, it is of special interest in online distance learning courses, where retention rates are reported to be lower than in face-to-face classes. Among the explanations and theories of retention rates in online courses, one that struck us as most useful is a structural one, namely, course…

  8. 5 CFR 351.404 - Retention register.

    Science.gov (United States)

    2010-01-01

    ... FORCE Scope of Competition § 351.404 Retention register. (a) When a competing employee is to be released from a competitive level under this part, the agency shall establish a separate retention register for... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention register. 351.404 Section 351...

  9. [Effect of acute hypoxia on the intensity of free radical processes in the basal nuclei of the brain, and the rat behaviour in the open field test under conditions of altered photoperiod].

    Science.gov (United States)

    Sopova, I Iu; Zamorskiĭ, I I

    2011-03-01

    The effect of acute hypoxia on the intensity of free radical processes in the basal nuclei (the nucleus caudatus, globus pallidus. nucleus accumbens. amygdaloid complex) of the brain, and the rat behaviour in the open field test has been studied under conditions of altered photoperiod. It has been shown that constant darkness levels the effect of acute hypoxia on the intensity of lipid peroxidation, preserves the activity of superoxide dismutase and catalase at a higher level, lowers the activity of glutathione peroxidase. Under light, the sensitivity of basal nuclei neurons to acute hypoxia is enhanced, the latter being reflected in intensification of lipid peroxidation at the expense of increased formation of dien conjugates. The activity of catalase at that considerably exceeds the level of even intact rats in all the structures. It has been established that an altered photoperiod modulates the effect of acute hypoxia on the parameters of rat's activity in the open field, the character of their change depending on the nature of a photophase change.

  10. Small scale retentive structures and Dinophysis

    Science.gov (United States)

    Xie, Hongqin; Lazure, Pascal; Gentien, Patrick

    2007-01-01

    Despite its rarity, Dinophysis acuminata is in terms of economic impact, the first toxic algal species along the coasts of Western Europe. It is observed at low levels (growth of this species will be a step forward to prediction of harmful events at the coast. This species has been observed at increased, albeit low cell densities in retentive eddies located in pycnocline layers. A concentration build-up of one species results from the balance between growth and loss processes, one of the latter being dispersal. The scales of interest for a D. acuminata population are of the order of 10 nautical miles on the horizontal and duration of 10 days, for a reported achievable growth rate of 0.6 day - 1 . A three dimensional (3D) hydrodynamical model of the Bay of Biscay has been elaborated to reproduce hydrological structures over the last decade. We attempt here to relate the existence of retentive structures revealed from simulations under realistic forcing conditions and the toxic coastal events recorded in the 10-year time series of the French plankton monitoring network database. The eddies in the coastal area appear to be directly related with the Dinophysis coastal events and they may be a potential effective tool to predict those.

  11. Alteration of 'R7T7' type nuclear glasses: statistical approach, experimental validation, local evolution model; Alteration des verres nucleaires de type 'R7T7': demarche statistique, validation experimentale, modele local d'evolution

    Energy Technology Data Exchange (ETDEWEB)

    Thierry, F

    2003-02-01

    The aim of this work is to propose an evolution of nuclear (R7T7-type) glass alteration modeling. The first part of this thesis is about development and validation of the 'r(t)' model. This model which predicts the decrease of alteration rates in confined conditions is based upon a coupling between a first-order dissolution law and a diffusion barrier effect of the alteration gel layer. The values and the uncertainties regarding the main adjustable parameters of the model ({alpha}, Dg and C*) have been determined from a systematic study of the available experimental data. A program called INVERSION has been written for this purpose. This work lead to characterize the validity domain of the 'r(t)' model and to parametrize it. Validation experiments have been undertaken, confirming the validity of the parametrization over 200 days. A new model is proposed in the second part of this thesis. It is based on an inhibition of glass dissolution reaction by silicon coupled with a local description of silicon retention in the alteration gel layer. This model predicts the evolutions of boron and silicon concentrations in solution as well as the concentrations and retention profiles in the gel layer. These predictions have been compared to measurements of retention profiles by the secondary ion mass spectrometry (SIMS) method. The model has been validated on fractions of gel layer which reactivity present low or moderate disparities. (author)

  12. NH4+ rather than NO3- production and retention processes are susceptible to enhanced NH4+ deposition in a subtropical plantation

    Science.gov (United States)

    Gao, Wenlong; Kou, Liang; Yang, Hao; Zhang, Jinbo; Muller, Christoph; Li, Shenggong

    2016-04-01

    It remains largely unknown how increasing N depositions may alter soil N cycling and N retention capacity of subtropical/tropical forest ecosystem functions. Here we report results from a 15N tracing study on soil from a subtropical forest plantation in China. Nitrogen fertilizer was applied monthly for more than 2.5 years at a rate of 40 (low) and 120 (high) kg NH4Cl-N hm-2 yr-1, respectively. High NH4+ input significantly retarded gross N mineralization, with a greater inhibition on mineralization of recalcitrant organic N than labile organic N which can possibly be related to a decreased fungal biomass. With increasing NH4+ inputs, rates of NH4+ immobilization into recalcitrant organic-N showed a trend of rise first and then fall. Interestingly, microbial NH4+ cycling moved toward to be a more open N cycling under low NH4+ input conditions, but was driven to be a tightly coupled N cycling under high NH4+ input conditions. On the contrary, microbial NO3- production (heterotrophic nitrification and autotrophic nitrification) and retention (NO3- immobilization and DNRA) processes showed insensitivity to elevated NH4+ input. Our results highlight that in acid subtropical/tropical forest soil, NH4+ rather than NO3- production and retention processes are susceptible to enhanced NH4+ deposition.

  13. Water Retention Curves of Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Romero, F. J.

    2012-11-01

    The water retention curve of Opalinus clay samples was determined under different conditions: total and matric suction, stress or no-stress conditions, wetting and drying paths. Through the fitting of these results to the van Genuchten expression the P parameter, related to the air entry value (AEV), was obtained. The AEV is the suction value above which air is able to enter the pores of the sample, and consequently, above which 2-phase flow can take place in the soil pore structure. The samples used in this research came from two different boreholes, BHT-1 and BHG-D1, but the behaviour of them did not depend on their location, what was probably due to the fact that both were drilled in the shay facies of the Opalinus clay. There was not a distinct difference between the results obtained under total or matric suctions. In the drying paths, both the water contents and the degrees of saturation tended to be higher when total suction was applied, however the reverse trend was observed for the water contents reached in wetting paths. As well, no clear difference was observed in the water retention curves obtained in odometers under matric and total suctions, what points to the osmotic component of suction in Opalinus clay not being significant. Overall, the water contents were lower and the degrees of saturation higher when suction was applied under vertical stress, what would indicate that the water retention capacity was lower under 8 MPa vertical stress than under free volume conditions. This vertical stress value is slightly higher than the maximum in situ stress. Also, the samples showed hysteresis according to the expected behaviour, i.e. the water contents for a given suction were higher during a drying path than during a wetting path. The P values obtained were between 6 and 34 MPa, and tended to be higher for the samples tested under stress, in drying paths and when total suction was used. The air entry value calculated from the mercury intrusion porosimetry

  14. Retention of Root Canal Posts

    DEFF Research Database (Denmark)

    Sahafi, A; Benetti, Ana Raquel; Flury, S;

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc......] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half...... received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement...

  15. Detailed insights into the retention mechanism of caffeine metabolites on the amide stationary phase in hydrophilic interaction chromatography.

    Science.gov (United States)

    Guo, Yong; Shah, Rajan

    2016-09-09

    The amide phase was investigated using a wide range of acetonitrile content in the mobile phase in both the HILIC and RPLC modes. Using caffeine metabolites as the model compounds, the retention, thermodynamic and kinetic data was obtained under various mobile phase conditions and supported the previous postulation that there might be a transition of the predominant retention mechanism in relation to the acetonitrile content in HILIC. On the amide phase, hydrophilic partitioning seemed to be the predominant retention mechanism below 85% acetonitrile; and a different retention mechanism (presumably surface adsorption) made more and more significant contributions to the overall retention when the acetonitrile content reached above 85%. This study also provided more direct evidences to explain the effect of salt concentration on the retention of non-charged solutes in HILIC. In addition, the retention, thermodynamic and kinetic data suggest that the amide phase behaved very differently from the conventional C18 phase in the RPLC mode.

  16. Hysteresis of Colloid Retention and Release in Saturated Porous Media During Transients in Solution Chemistry

    Science.gov (United States)

    Saturated packed column and micromodel transport studies wereconducted to gain insightonmechanismsof colloid retention and release under unfavorable attachment conditions. The initial deposition of colloids in porous media was found to be a strongly coupled process that depended on solution chemistr...

  17. How stress alters memory in 'smart' snails.

    Directory of Open Access Journals (Sweden)

    Sarah Dalesman

    Full Text Available Cognitive ability varies within species, but whether this variation alters the manner in which memory formation is affected by environmental stress is unclear. The great pond snail, Lymnaea stagnalis, is commonly used as model species in studies of learning and memory. The majority of those studies used a single laboratory strain (i.e. the Dutch strain originating from a wild population in the Netherlands. However, our recent work has identified natural populations that demonstrate significantly enhanced long-term memory (LTM formation relative to the Dutch strain following operant conditioning of aerial respiratory behaviour. Here we assess how two populations with enhanced memory formation (i.e. 'smart' snails, one from Canada (Trans Canada 1: TC1 and one from the U.K. (Chilton Moor: CM respond to ecologically relevant stressors. In control conditions the Dutch strain forms memory lasting 1-3 h following a single 0.5 h training session in our standard calcium pond water (80 mg/l [Ca(2+], whereas the TC1 and CM populations formed LTM lasting 5+ days following this training regime. Exposure to low environmental calcium pond water (20 mg/l [Ca(2+], which blocks LTM in the Dutch strain, reduced LTM retention to 24 h in the TC1 and CM populations. Crowding (20 snails in 100 ml immediately prior to training blocks LTM in the Dutch strain, and also did so in TC1 and CM populations. Therefore, snails with enhanced cognitive ability respond to these ecologically relevant stressors in a similar manner to the Dutch strain, but are more robust at forming LTM in a low calcium environment. Despite the two populations (CM and TC1 originating from different continents, LTM formation was indistinguishable in both control and stressed conditions. This indicates that the underlying mechanisms controlling cognitive differences among populations may be highly conserved in L. stagnalis.

  18. Transport and retention of bacteria and viruses in biochar-amended sand.

    Science.gov (United States)

    Sasidharan, Salini; Torkzaban, Saeed; Bradford, Scott A; Kookana, Rai; Page, Declan; Cook, Peter G

    2016-04-01

    The transport and retention of Escherichia coli and bacteriophages (PRD1, MS2 and ФX174), as surrogates for human pathogenic bacteria and viruses, respectively, were studied in the sand that was amended with several types of biochar produced from various feedstocks. Batch and column studies were conducted to distinguish between the role of attachment and straining in microbe retention during transport. Batch experiments conducted at various solution chemistries showed negligible attachment of viruses and bacteria to biochar before or after chemical activation. At any given solution ionic strength, the attachment of viruses to sand was significantly higher than that of biochar, whereas bacteria showed no attachment to either sand or biochar. Consistent with batch results, biochar addition (10% w/w) to sand reduced virus retention in the column experiments, suggesting a potential negative impact of biochar application to soil on virus removal. In contrast, the retention of bacteria was enhanced in biochar-amended sand columns. However, elimination of the fine fraction (bacteria retention. Results from batch and column experiments suggest that land application of biochar may only play a role in microbe retention via straining, by alteration of pore size distribution, and not via attachment. Consequently, the particle size distribution of biochar and sediments is a more important factor than type of biochar in determining whether land application of biochar enhances or diminishes microbial retention.

  19. Enhanced methodology for porting ion chromatography retention data.

    Science.gov (United States)

    Park, Soo Hyun; Shellie, Robert A; Dicinoski, Greg W; Schuster, Georg; Talebi, Mohammad; Haddad, Paul R; Szucs, Roman; Dolan, John W; Pohl, Christopher A

    2016-03-04

    Porting is a powerful methodology to recalibrate an existing database of ion chromatography (IC) retention times by reflecting the changes of column behavior resulting from either batch-to-batch variability in the production of the column or the manufacture of new versions of a column. This approach has been employed to update extensive databases of retention data of inorganic and organic anions forming part of the "Virtual Column" software marketed by Thermo Fisher Scientific, which is the only available commercial optimization tool for IC separation. The current porting process is accomplished by performing three isocratic separations with two representative analyte ions in order to derive a porting equation which expresses the relationship between old and new data. Although the accuracy of retention prediction is generally enhanced on new columns, errors were observed on some columns. In this work, the porting methodology was modified in order to address this issue, where the porting equation is now derived by using six representative analyte ions (chloride, bromide, iodide, perchlorate, sulfate, and thiosulfate). Additionally, the updated porting methodology has been applied on three Thermo Fisher Scientific columns (AS20, AS19, and AS11HC). The proposed approach showed that the new porting methodology can provide more accurate and robust retention prediction on a wide range of columns, where average errors in retention times for ten test anions under three eluent conditions were less than 1.5%. Moreover, the retention prediction using this new approach provided an acceptable level of accuracy on a used column exhibiting changes in ion-exchange capacity.

  20. Collaborative learning in engineering: A quest to improve student retention

    Science.gov (United States)

    Marquard, Paul J.

    Colleges of engineering are concerned with retention of their undergraduates. Several studies have determined the reasons students leave engineering to major in other disciplines. The list includes poor teaching, a difficult curriculum, and a lack of belonging. This study alters the traditional lecture format of an engineering dynamics class by using a flipped classroom where scheduled class time emphasizes a collaborative learning pedagogy. Material coverage was facilitated with online lectures. After initiating this change, student attitudes and self-efficacy were measured as well as test performance and study time.

  1. 条件性恐惧消退保持早期边缘下区细胞周期素依赖性蛋白激酶5的动态变化%Change of cyclin-dependent kinase 5 in infra-limbic cortex in the early of conditioned fear extinction retention

    Institute of Scientific and Technical Information of China (English)

    李培培; 李敏; 张丽丽; 韦美; 汪涛

    2010-01-01

    Objective To observe the change of cyclin-dependent kinase 5(Cdk5)in infra-limbie cortex in the early of conditioned fear extinction retention.Methods Fifty-six male adult SD rats were randomly divided into extinction group,sham extinction group and naive group.Conditioned fear model of rats was established by tone paired foot shock.Fear extinction was trained in 24 hours after establishment of fear memory.For extinction group and sham extinction group,retention test and immunnohistochemistry of Cdk5 were done at 2nd,4th and 8th day after fear.Results(1)Retention scores of extinction group and sham extinction group were worse than naive group at 2nd and 4th days after fear(P<0.01),the scores of extinction group(71.04±11.65)and naive group were better than sham extinction group(35.48±12.37,P<0.01)at 8th day after fear.(2)Cdk5 in IL of sham extinction group increased at 2nd day after fear(429±70,P<0.05),the expression of extinction group's Cdk5 deereasod at 4th day after fear(208±30,P<0.01),but it returned to normal at 8th day after fear.Conclusion The expression of Cdk5 in IL may increase after conditioned fear,but extinction may reduce its expression,which may be good for the early of conditioned fear extinction retention.%目的 研究内侧前额叶皮层边缘下区(IL区)细胞周期素依赖性蛋白激酶5(Cdk5)在条件性恐惧消退保持早期的动态变化.方法 成年雄性SD大鼠56只,随机分为消退组(n=24)、假消退组(n=24)和正常组(n=8).采用声音结合足底电击建立大鼠条件性恐惧模型,消退组在恐惧建模后24h进行消退训练,假消退组则不进行消退训练,2组均在不同时间点(恐惧建模后第2、4和8天)测定消退保持成绩,并用免疫组织化学法检测各组大鼠内侧前额叶皮层IL区Cdk5的表达.结果 (1)与正常组相比,消退组和假消退组在恐惧建立后第2天和第4天的不僵立时间百分比显著较少(P<0.01),而在恐惧建立后第8天,消退组的

  2. Gastro retention using polymer cocoons.

    Science.gov (United States)

    Arnold, Julien; Hunkeler, David

    2015-02-01

    A gastro-retentive capsule has been prepared which is retained in the stomach for a period of 24h, providing a vehicle for the controlled delivery to the upper intestines. These "gastro cocoons" can resist passage through the sphincter of the stomach, and can retain a high drug payload (30%). They are made from oppositely charged polyelectrolytes and can swell to twice their initial volume. They are strong and also can resist 550 N of compressive force. They are based on filled pharmaceutical capsules which are visible to X-rays. Using ambroxol hydrochloride as a model drug linear, zero-order, release curves were obtained.

  3. Retention of Highly Skilled Workers in Science and Technology: Distant Regional Employers’ Point of View

    Directory of Open Access Journals (Sweden)

    Catherine Beaudry

    2014-05-01

    Full Text Available This exploratory research focuses on the retention of highly skilled workers in science and technology (HSWST in the distant regions of Canada.  Indeed, the human resource shortage forces them to seek more stability in their employment relationships. Our first objective is to analyze the point of view of distant regional employers regarding their retention capacity of HSWST and the reasons behind voluntary turnover in this group of workers. Our second objective is to analyze the retention strategies and practices implemented by these employers. This study uses a qualitative approach, which is to say the case study of businesses hiring HSWST in the Lower St. Lawrence Region of Canada. Results show that employers generally think they have good retention capacity. Employers believe that departures are chiefly due to personal reasons or working conditions. In addition, employers generally have no formal or planned strategies or practices with respect to retention.

  4. The effect of brumation on memory retention

    Science.gov (United States)

    Wilkinson, Anna; Hloch, Anne; Mueller-Paul, Julia; Huber, Ludwig

    2017-01-01

    Long-term torpor is an adaptive strategy that allows animals to survive harsh winter conditions. However, the impact that prolonged torpor has on cognitive function is poorly understood. Hibernation causes reduced synaptic activity and experiments with mammals reveal that this can have adverse effects on memories formed prior to hibernation. The impact of brumation, the winter dormancy that is observed in ectotherms, on memory remains unknown. The aim of this study was to examine whether an amphibian, the fire salamander (Salamandra salamandra), was able to retain learned spatial information after a period of brumation. Twelve fire salamanders were trained to make a simple spatial discrimination using a T-maze. All subjects learned the initial task. Upon reaching criterion, half of the subjects were placed into brumation for 100 days while the other half served as controls and were maintained under normal conditions. A post-brumation memory retention test revealed that animals from both conditions retained the learned response. Control tests showed that they solved the task using learned information and not olfactory cues. This finding contrasts with much of the mammalian research and suggests that the processes involved in prolonged torpor may have a fundamentally different impact on memory in mammals and amphibians. PMID:28074838

  5. Promotion effect of D-cycloserine on long-term retention of rat extinction memory of conditioned fear%D-环丝氨酸促进大鼠条件性恐惧消退记忆的长期保持

    Institute of Scientific and Technical Information of China (English)

    张钰; 李敏

    2011-01-01

    目的 研究D-环丝氨酸(D-serine,DCS)对条件性恐惧消退记忆的长时保持的影响.方法 成年雄性SD大鼠40只,采用完全随机方法分为空白对照组、消退对照组、消退训练组、消退训练前DCS干预组、消退训练后DCS干预组,每组8只.在消退训练后3d时进行僵立行为测试与旷场行为测试.结果 ①消退训练组的僵立时间百分比[(39.77±22.69)%]显著低于消退对照组[(61.46±11.10)%](P<0.05),但仍高于空白对照组[(2.82±1.27)%](P<0.01);旷场测试中消退训练组的中央路程百分比及直立次数[(2.82±2.89)%,(7±4)]显著高于消退对照组[(0.50±0.84)%,(3士4)],但低于空白对照组[(19.29±6.08)%,(20±6)](P<0.05);②消退训练后DCS干预组的僵立时间百分比与旷场行为测试成绩与其他组比较均有统计学差异(P<0.05).结论 消退训练后给予D-环丝氨酸能够促进条件化恐惧消退记忆的长时保持.%Objective To investigate the influence of D-cycloserine (DCS) on the long-term retention of rat extinction memory of conditioned fear. Methods Forty healthy male adult SD rats were randomly divided into five groups (n = 8 ): a blank control group, an extinction control group, an extinction training group, a group with DCS treatment before extinction training, and a group with DCS treatment after extinction training. Following fear conditioning, which includes auditory conditioned stimulus (CS) paired with foot-shock uncondi tioned stimulus (US), rats received non-reinforced exposure to CS for extinction training. CS-elicited freezing test for fear assessment and open-field test were conducted 3 d after extinction training. Results The percent age of freezing time of the extinction training group [( 39.77 ± 22.69 ) %]was significantly lower than that of the extinction control group[(61.46 ± 11.10) %]( P < 0. 05 ), but significantly higher than that of the blank control group[(2.82 ± 1.27)%](P <0. 01 ). The percentage of

  6. Fission-product retention in HTGR fuels

    Energy Technology Data Exchange (ETDEWEB)

    Homan, F.J.; Kania, M.J.; Tiegs, T.N.

    1982-01-01

    Retention data for gaseous and metallic fission products are presented for both Triso-coated and Biso-coated HTGR fuel particles. Performance trends are established that relate fission product retention to operating parameters, such as temperature, burnup, and neutron exposure. It is concluded that Biso-coated particles are not adequately retentive of fission gas or metallic cesium, and Triso-coated particles which retain cesium still lose silver. Design implications related to these performance trends are identified and discussed.

  7. Tree retention in boreal pine forest

    OpenAIRE

    Santaniello, Francesca

    2017-01-01

    Tree retention forestry aims at increasing structural diversity in managed forests. In this study, I have investigated the influence of tree retention forestry on delivery of two ecosystem services (wood production and carbon sequestration) and dead wood (as a proxy for biodiversity). Furthermore, habitat requirements of lichens dependent on dead wood were investigated. The study was conducted in 15 Scots pine forest stands with five various tree retention levels, in which four...

  8. Plant community controls on short-term ecosystem nitrogen retention.

    Science.gov (United States)

    de Vries, Franciska T; Bardgett, Richard D

    2016-05-01

    Retention of nitrogen (N) is a critical ecosystem function, especially in the face of widespread anthropogenic N enrichment; however, our understanding of the mechanisms involved is limited. Here, we tested under glasshouse conditions how plant community attributes, including variations in the dominance, diversity and range of plant functional traits, influence N uptake and retention in temperate grassland. We added a pulse of (15) N to grassland plant communities assembled to represent a range of community-weighted mean plant traits, trait functional diversity and divergence, and species richness, and measured plant and microbial uptake of (15) N, and leaching losses of (15) N, as a short-term test of N retention in the plant-soil system. Root biomass, herb abundance and dominant plant traits were the main determinants of N retention in the plant-soil system: greater root biomass and herb abundance, and lower root tissue density, increased plant (15) N uptake, while higher specific leaf area and root tissue density increased microbial (15) N uptake. Our results provide novel, mechanistic insight into the short-term fate of N in the plant-soil system, and show that dominant plant traits, rather than trait functional diversity, control the fate of added N in the plant-soil system.

  9. Biofilm retention on surfaces with variable roughness and hydrophobicity.

    Science.gov (United States)

    Tang, Lone; Pillai, Saju; Revsbech, Niels Peter; Schramm, Andreas; Bischoff, Claus; Meyer, Rikke Louise

    2011-01-01

    Biofilms on food processing equipment cause food spoilage and pose a hazard to consumers. The bacterial community on steel surfaces in a butcher's shop was characterized, and bacteria representative of this community enriched from minced pork were used to study biofilm retention. Stainless steel (SS) was compared to two novel nanostructured sol-gel coatings with differing hydrophobicity. Surfaces were characterized with respect to roughness, hydrophobicity, protein adsorption, biofilm retention, and community composition of the retained bacteria. Fewer bacteria were retained on the sol-gel coated surfaces compared to the rougher SS. However, the two sol-gel coatings did not differ in either protein adsorption, biofilm retention, or microbial community composition. When polished to a roughness similar to sol-gel, the SS was colonized by the same amount of bacteria as the sol-gel, but the bacterial community contained fewer Pseudomonas cells. In conclusion, biofilm retention was affected more by surface roughness than chemical composition under the condition described in this study.

  10. Morphine-induced conditioned place preference and the alterations of p-ERK, p-CREB and c-fos levels in hypothalamus and hippocampus: the effects of physical stress.

    Science.gov (United States)

    Pahlevani, P; Fatahi, Z; Moradi, M; Haghparast, A

    2014-12-08

    The hypothalamus and hippocampus are important areas involved in stress responses and reward processing. In addition, ERK/CREB pathway plays a critical role in the control of cellular responses to stress and reward. In the current study, effects of acute and subchronic stress on the alteration of p-ERK, p-CREB and c-fos levels in the hypothalamus and hippocampus of saline- or morphine-treated animals during morphine-induced conditioned place preference (CPP) procedure were investigated. Male Wistar rats were divided into two saline- and morphine-treated supergroups. Each supergroup includes of control, acute stress and subchronic stress groups. In all of groups, the CPP procedure was done, afterward the alternation of p-ERK/ERK ratio, p-CREB/CREB ratio and c-fos level in the hypothalamus and hippocampus were estimated by Western blot analysis. The results indicated that in saline- or morphine-treated animals, p-ERK/ERK ratio, p-CREB/CREB ratio and c-fos level increased after application of acute and subchronic stress (except for p-ERK/ERK ratio in morphine-control group). Our findings revealed that in saline- or morphine-treated animals, acute and subcronic stress increased the p-ERK/ERK ratio, p-CREB/CREB ratio and c-fos level in the hypothalamus and hippocampus and this enhancement in morphine-treated animals, was more considerable than that in saline-treated animals.

  11. Time-Induced Super-Latent Inhibition Is Dependent on the Distinctiveness of the Retention-Interval Context from the Other Experimental Contexts

    Science.gov (United States)

    Lubow, R.E.; De la Casa, L.G.

    2005-01-01

    A conditioned taste aversion experiment examined the role of the retention-interval context (between conditioning and test stages) on the modulation of long-delay latent inhibition (LI). A super-LI effect was obtained only when the animals spent the retention interval in a context that was different from that of preexposure, conditioning, and…

  12. Experimental Evidence of the Relative Effectiveness of Problem-Based Learning for Knowledge Acquisition and Retention

    Science.gov (United States)

    Wijnen, Marit; Loyens, Sofie M. M.; Schaap, Lydia

    2016-01-01

    This study investigated the effects of problem-based learning (PBL) on knowledge acquisition and knowledge retention in a controlled experiment in a lab setting. Eighty-eight first-year psychology students were randomly assigned to either a PBL condition, a lecture condition, or a self-study condition. All participants had the opportunity to study…

  13. Breastfeeding reduces postpartum weight retention

    DEFF Research Database (Denmark)

    Baker, Jennifer Lyn; Gamborg, Michael; Heitmann, Berit L

    2008-01-01

    BACKGROUND: Weight gained during pregnancy and not lost postpartum may contribute to obesity in women of childbearing age. OBJECTIVE: We aimed to determine whether breastfeeding reduces postpartum weight retention (PPWR) in a population among which full breastfeeding is common and breastfeeding...... duration is long. DESIGN: We selected women from the Danish National Birth Cohort who ever breastfed (>98%), and we conducted the interviews at 6 (n = 36 030) and 18 (n = 26 846) mo postpartum. We used regression analyses to investigate whether breastfeeding (scored to account for duration and intensity......) reduced PPWR at 6 and 18 mo after adjustment for maternal prepregnancy body mass index (BMI) and gestational weight gain (GWG). RESULTS: GWG was positively (P Breastfeeding was negatively associated with PPWR in all women but those...

  14. The Medical School Retention Game

    DEFF Research Database (Denmark)

    O'Neill, Lotte Dyhrberg; Hartvigsen, Jan; Wallstedt, Birgitta

    2011-01-01

    grades (quota 1), while the other half went through a composite non-grade based admission test (quota 2). Educational as well as social predictor variables (doctor parent, origin in the developed world, parenthood, parents live together, parent on benefit, university educated parents) were also examined...... association between admission-test survival and program retention – a program specific admission test survivability factor - regardless of admission-test content, prior education, and program priority. The generalisability and other important limitations of the results (e.g. missing data, potential...... scores and dropout. REFERENCES 1.O’Neill L, Wallstedt B, Eika B, Hartvigsen J. Factors associated with dropout in medical education: a literature review. Med Educ (In press). 2.Urlings-Strop LC, Stijnen T, Themmen APN, Splinter TAW. Selection of medical students: a controlled experiment. Med Educ 2009...

  15. Developing retention and return strategies for South African advanced life support paramedics: A qualitative study

    Directory of Open Access Journals (Sweden)

    Kevin Govender

    2013-06-01

    Results and discussion: Findings suggest that the success of retention and return strategies depends on the degree of collaborative stewardship that must exist between the SA National and Provincial Department of Health, the Emergency Medical Service/s (EMS statutory governing body, training institutions, and private and public EMS providers. In addition, the constructs of return and retention strategies have to extend as far as revising both acceptance criteria and candidate recruitment policies. Furthermore, while particular attention must be placed on improving working conditions, security, and remuneration of ALS paramedics, return and retention strategies have to be continuously monitored, and updated.

  16. Altered anterior visual system development following early monocular enucleation

    Directory of Open Access Journals (Sweden)

    Krista R. Kelly

    2014-01-01

    Conclusions: The novel finding of an asymmetry in morphology of the anterior visual system following long-term survival from early monocular enucleation indicates altered postnatal visual development. Possible mechanisms behind this altered development include recruitment of deafferented cells by crossing nasal fibres and/or geniculate cell retention via feedback from primary visual cortex. These data highlight the importance of balanced binocular input during postnatal maturation for typical anterior visual system morphology.

  17. Galantamine reverses scopolamine-induced behavioral alterations in Dugesia tigrina.

    Science.gov (United States)

    Ramakrishnan, Latha; Amatya, Christina; DeSaer, Cassie J; Dalhoff, Zachary; Eggerichs, Michael R

    2014-09-01

    In planaria (Dugesia tigrina), scopolamine, a nonselective muscarinic receptor antagonist, induced distinct behaviors of attenuated motility and C-like hyperactivity. Planarian locomotor velocity (pLMV) displayed a dose-dependent negative correlation with scopolamine concentrations from 0.001 to 1.0 mM, and a further increase in scopolamine concentration to 2.25 mM did not further decrease pLMV. Planarian hyperactivity counts was dose-dependently increased following pretreatment with scopolamine concentrations from 0.001 to 0.5 mM and then decreased for scopolamine concentrations ≥ 1 mM. Planarian learning and memory investigated using classical Pavlovian conditioning experiments demonstrated that scopolamine (1 mM) negatively influenced associative learning indicated by a significant decrease in % positive behaviors from 86 % (control) to 14 % (1 mM scopolamine) and similarly altered memory retention, which is indicated by a decrease in % positive behaviors from 69 % (control) to 27 % (1 mM scopolamine). Galantamine demonstrated a complex behavior in planarian motility experiments since co-application of low concentrations of galantamine (0.001 and 0.01 mM) protected planaria against 1 mM scopolamine-induced motility impairments; however, pLMV was significantly decreased when planaria were tested in the presence of 0.1 mM galantamine alone. Effects of co-treatment of scopolamine and galantamine on memory retention in planaria via classical Pavlovian conditioning experiments showed that galantamine (0.01 mM) partially reversed scopolamine (1 mM)-induced memory deficits in planaria as the % positive behaviors increased from 27 to 63 %. The results demonstrate, for the first time in planaria, scopolamine's effects in causing learning and memory impairments and galantamine's ability in reversing scopolamine-induced memory impairments.

  18. Persistent postpartum urinary retention following vaginal delivery: a rare complication in obstetrics practice

    Directory of Open Access Journals (Sweden)

    Amrita Chaurasia

    2013-06-01

    Full Text Available Postpartum urinary retention occurs in 10-15% of women and is likely to be multifactorial in origin. Long labour, epidural analgesia, instrumental delivery, nulliparity, significant vaginal and perineal laceration or a previous history of voiding difficulty are risk factors for altered voiding parameters. Previous literatures have defined two types of urinary retention, first, overt retention and the other covert variety. Overt variety represents the acute retention while covert variety is of subacute in nature. Being subacute in nature, it damages the detrusors slowly. Sometimes the damage is so much so that it may take substantial time to recover or may not recover at all and the patient may have lifelong detrusor hypotonia with persistent urinary retention, requiring lifelong intermittent self-catheterization. This badly affects her personal as well as social wellbeing and also poses her for recurrent urinary tract infection. Here, we report a case of 25 yrs old, 36 weeks primigravida having persistent postpartum urinary retention following vaginal delivery, Who was enough fortunate to have recovery of detrusors. But, still it took 3-4 weeks for complete recovery of the urinary bladder. [Int J Reprod Contracept Obstet Gynecol 2013; 2(3.000: 475-477

  19. 12 CFR 609.945 - Records retention.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Records retention. 609.945 Section 609.945 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM ELECTRONIC COMMERCE Standards for Boards and Management § 609.945 Records retention. Records stored electronically must be accurate,...

  20. 5 CFR 353.302 - Retention protections.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Retention protections. 353.302 Section... TO DUTY FROM UNIFORMED SERVICE OR COMPENSABLE INJURY Compensable Injury § 353.302 Retention protections. An injured employee enjoys no special protection in a reduction in force. Separation by reduction...

  1. Managing human resources to improve employee retention.

    Science.gov (United States)

    Arnold, Edwin

    2005-01-01

    Managers face increased challenges as the demand for health care services increases while the supply of employees with the requisite skills continues to lag. Employee retention will become more important in the effort to service health care needs. Appropriate human resource management strategies and policies implemented effectively can significantly assist managers in dealing with the employee retention challenges ahead.

  2. 76 FR 24089 - Credit Risk Retention

    Science.gov (United States)

    2011-04-29

    ... Department of Housing and Urban Development 24 CFR Part 267 Credit Risk Retention; Proposed Rule #0;#0..., and HUD (the Agencies) are proposing rules to implement the credit risk retention requirements of... securitizer of asset-backed securities to retain not less than five percent of the credit risk of the...

  3. Positive Youth Development and Undergraduate Student Retention

    Science.gov (United States)

    Demetriou, Cynthia; Powell, Candice

    2014-01-01

    The primary theoretical tradition in the study of college retention has been sociological. A review and synthesis of common themes of development among traditional-age, college students suggests that a developmental perspective on the retention of youth in college may have more to offer than the dominant sociological paradigm. This article argues…

  4. 12 CFR 219.24 - Retention period.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Retention period. 219.24 Section 219.24 Banks...) Recordkeeping and Reporting Requirements for Funds Transfers and Transmittals of Funds § 219.24 Retention period. All records that are required to be retained by this subpart shall be retained for a period of five...

  5. Novel Word Retention in Sequential Bilingual Children

    Science.gov (United States)

    Kan, Pui Fong

    2014-01-01

    Children's ability to learn and retain new words is fundamental to their vocabulary development. This study examined word retention in children learning a home language (L1) from birth and a second language (L2) in preschool settings. Participants were presented with sixteen novel words in L1 and in L2 and were tested for retention after…

  6. African Retentions in Blues and Jazz.

    Science.gov (United States)

    Meadows, Eddie S.

    1979-01-01

    The perseverance of African musical characteristics among American Blacks is an historic reality. African retentions have been recorded in Black music of the antebellum period. Various African scales and rhythms permeate Black American music today as evidenced in the retentions found in blues and jazz. (RLV)

  7. Staff nurse retention: strategies for success.

    Science.gov (United States)

    Lassiter, S S

    1989-04-01

    At the same time the demand for nurses is on the rise, the supply is dwindling. Recruitment and retention are the two main factors which can be adjusted to affect supply. Recruitment has become increasingly difficult in the past two or three years due to decreasing enrollment in nursing education programs and increased demand for nurses in alternative delivery systems. Therefore staff nurse retention has become an issue of major importance. This article will begin by briefly delineating need and expectancy theories which in part explain job satisfaction and, hence, retention. Secondly, findings from the Magnet Hospital Study are summarized. Creative retention strategies will then be explored, concluding with a framework for developing a strategic plan for successful staff nurse retention.

  8. Optimization based on retention prediction and information theory for liquid-chromatographic analysis of alkylbenzenes

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Rieko; Hayashi Yuzuru; Suzuki Takashi; Saito Yukio (National Inst. of Hygienic Sciences, Tokyo (Japan)); Jinno Kiyokatsu (Toyohashi Univ. of Technology (Japan))

    1991-11-01

    The mobile phase composition and column length are optimized for analyses of six alkylbenzenes in reversed-phase liquid chromatography with the aid of retention prediction and information theory. Optimal conditions selected according to the resolution Rs and information theory are evaluated from the viewpoint of the precision and analytical efficiency (rapidity) of chromatography. The combination of the information-theoretical optimization with the retention prediction will accelerate the development in the automation of liquid-chromatographic analysis.

  9. Biogenesis of lysosomal enzymes in the alpha-glucosidase II-deficient modA mutant of Dictyostelium discoideum: retention of alpha-1,3-linked glucose on N-linked oligosaccharides delays intracellular transport but does not alter sorting of alpha-mannosidase or beta-glucosidase.

    Science.gov (United States)

    Ebert, D L; Bush, J M; Dimond, R L; Cardelli, J A

    1989-09-01

    The endoplasmic reticulum-localized enzyme alpha-glucosidase II is responsible for removing the two alpha-1,3-linked glucose residues from N-linked oligosaccharides of glycoproteins. This activity is missing in the modA mutant strain, M31, of Dictyostelium discoideum. Results from both radiolabeled pulse-chase and subcellular fractionation experiments indicate that this deficiency did not prevent intracellular transport and proteolytic processing of the lysosomal enzymes, alpha-mannosidase and beta-glucosidase. However, the rate at which the glucosylated precursors left the rough endoplasmic reticulum was several-fold slower than the rate at which the wild-type precursors left this compartment. Retention of glucose residues did not disrupt the binding of the precursor forms of the enzymes with intracellular membranes, indicating that the delay in movement of proteins from the ER did not result from lack of association with membranes. However, the mutant alpha-mannosidase precursor contained more trypsin-sensitive sites than did the wild-type precursor, suggesting that improper folding of precursor molecules might account for the slow rate of transport to the Golgi complex. Percoll density gradient fractionation of extracts prepared from M31 cells indicated that the proteolytically processed mature forms of alpha-mannosidase and beta-glucosidase were localized to lysosomes. Finally, the mutation in M31 may have other, more dramatic, effects on the lysosomal system since two enzymes, N-acetylglucosaminidase and acid phosphatase, were secreted much less efficiently from lysosomal compartments by the mutant strain.

  10. Clay particle retention in small constructed wetlands.

    Science.gov (United States)

    Braskerud, B C

    2003-09-01

    Constructed wetlands (CWs) can be used to mitigate non-point source pollution from arable fields. Previous investigations have shown that the relative soil particle retention in small CWs increases when hydraulic load increases. This paper investigates why this phenomenon occurs, even though common retention models predict the opposite, by studying clay and silt particle retention in two Norwegian CWs. Retention was measured with water flow proportional sampling systems in the inlet and outlet of the wetlands, and the texture of the suspended solids was analyzed. The surface area of the CWs was small compared to the watershed area (approximately 0.07%), giving high average hydraulic loads (1.1 and 2.0 md(-1)). One of the watersheds included only old arable land, whereas the other included areas with disturbed topsoil after artificial land leveling. Clay particle retention was 57% for the CW in the first watershed, and 22% for the CW in the disturbed watershed. The different behavior of the wetlands could be due to differences in aggregate size and stability of the particles entering the wetlands. Results showed that increased hydraulic loads did affect CW retention negatively. However, as runoff increased, soil particles/aggregates with higher sedimentation velocities entered the CWs (e.g., the clay particles behaved as silt particles). Hence, clay particle settling velocity is not constant as assumed in many prediction models. The net result was increased retention.

  11. Scale and Seasonal Controls on Nitrate and Sediment Retention in Freshwater Tidal Wetlands

    Science.gov (United States)

    Prestegaard, K. L.; Seldomridge, E.; Statkiewicz, A.

    2013-12-01

    Channel networks in freshwater tidal wetlands convey water, sediment, and solutes into marsh interiors where sediment deposition and biogeochemical processes, such as denitrification and nitrogen uptake occur. Tidal inlets that connect these channel network systems to the main estuary define the initial solute or sediment load into these systems, but channel, soil, and vegetation characteristics influence nitrate and sediment retention. We used field measurements and remotely sensed images to determine marsh area, stream length, inlet morphology, and channel morphology for the 267 marshes in the freshwater tidal ecosystem. Discharge and water volume over high tidal cycles was measured at selected inlets representative of the range of inlet sizes in the ecosystem. Aquatic vegetation distribution and density was also measured at these inlets. These data were used to develop geomorphic-hydraulic relationships for the marshes for winter (no vegetation) and summer (vegetated) conditions. Nitrate and sediment retention were determined from field mass balance measurements based on water flux and concentration measurements taken over tidal cycle at inlets to selected marshes of varying size over a 3-year period. These mass balance data indicate that net nitrate retention is a simple function of tidal water volume for marshes of different sizes and for various vegetated conditions. These data suggest that nitrate retention is transport limited for the range of initial nitrate concentrations observed in this system. Although nitrate retention was a function of tidal water volume, it was also seasonally variable due to restrictions in water flow and volume caused by aquatic vegetation in summer months. Sediment retention is seasonally variable due to the strong controls exerted by emergent and submerged aquatic vegetation and decoupled from the water volume dependence observed for nitrate retention. Variations in sediment retention caused by vegetation resulted in channel

  12. Retention Models on Core-Shell Columns.

    Science.gov (United States)

    Jandera, Pavel; Hájek, Tomáš; Růžičková, Marie

    2017-07-13

    A thin, active shell layer on core-shell columns provides high efficiency in HPLC at moderately high pressures. We revisited three models of mobile phase effects on retention for core-shell columns in mixed aqueous-organic mobile phases: linear solvent strength and Snyder-Soczewiński two-parameter models and a three-parameter model. For some compounds, two-parameter models show minor deviations from linearity due to neglect of possible minor retention in pure weak solvent, which is compensated for in the three-parameter model, which does not explicitly assume either the adsorption or the partition retention mechanism in normal- or reversed-phase systems. The model retention equation can be formulated as a function of solute retention factors of nonionic compounds in pure organic solvent and in pure water (or aqueous buffer) and of the volume fraction of an either aqueous or organic solvent component in a two-component mobile phase. With core-shell columns, the impervious solid core does not participate in the retention process. Hence, the thermodynamic retention factors, defined as the ratio of the mass of the analyte mass contained in the stationary phase to its mass in the mobile phase in the column, should not include the particle core volume. The values of the thermodynamic factors are lower than the retention factors determined using a convention including the inert core in the stationary phase. However, both conventions produce correct results if consistently used to predict the effects of changing mobile phase composition on retention. We compared three types of core-shell columns with C18-, phenyl-hexyl-, and biphenyl-bonded phases. The core-shell columns with phenyl-hexyl- and biphenyl-bonded ligands provided lower errors in two-parameter model predictions for alkylbenzenes, phenolic acids, and flavonoid compounds in comparison with C18-bonded ligands.

  13. Formation and retention of methane in coal

    Energy Technology Data Exchange (ETDEWEB)

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  14. Uptake and retention of amitriptyline by kaolinite.

    Science.gov (United States)

    Lv, Guocheng; Stockwell, Christie; Niles, Jacqueline; Minegar, Skylar; Li, Zhaohui; Jiang, Wei-Teh

    2013-12-01

    As the most commonly prescribed tricyclic antidepressant, amitriptyline (AT) is frequently detected in wastewater, surface runoff, and effluents from sewage treatment plants, and could potentially reach agriculture land through the application of municipal biosolids or reclaimed water. Kaolinite is one of the most important soil components under warm and humid climate conditions. In this study, the uptake and retention of AT by kaolinite from aqueous solution were investigated by batch tests, XRD, and FTIR analyses. The uptake of AT on kaolinite was instantaneous, attributed to surface adsorption as confirmed by XRD analyses. Quantitative correlation between desorption of exchangeable cations and AT adsorption confirmed experimentally that cation exchange was the dominant mechanism of AT uptake on kaolinite. The values for free energy of adsorption also suggested physi-sorption such as cation exchange. Solution pH had minimal influence at pH 5-11 even though the pKa value of AT was 9.4 and the surface charge of kaolinite was pH-dependent. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Effect of ceramic membrane channel diameter on limiting retentate protein concentration during skim milk microfiltration.

    Science.gov (United States)

    Adams, Michael C; Barbano, David M

    2016-01-01

    Our objective was to determine the effect of retentate flow channel diameter (4 or 6mm) of nongraded permeability 100-nm pore size ceramic membranes operated in nonuniform transmembrane pressure mode on the limiting retentate protein concentration (LRPC) while microfiltering (MF) skim milk at a temperature of 50°C, a flux of 55 kg · m(-2) · h(-1), and an average cross-flow velocity of 7 m · s(-1). At the above conditions, the retentate true protein concentration was incrementally increased from 7 to 11.5%. When temperature, flux, and average cross-flow velocity were controlled, ceramic membrane retentate flow channel diameter did not affect the LRPC. This indicates that LRPC is not a function of the Reynolds number. Computational fluid dynamics data, which indicated that both membranes had similar radial velocity profiles within their retentate flow channels, supported this finding. Membranes with 6-mm flow channels can be operated at a lower pressure decrease from membrane inlet to membrane outlet (ΔP) or at a higher cross-flow velocity, depending on which is controlled, than membranes with 4-mm flow channels. This implies that 6-mm membranes could achieve a higher LRPC than 4-mm membranes at the same ΔP due to an increase in cross-flow velocity. In theory, the higher LRPC of the 6-mm membranes could facilitate 95% serum protein removal in 2 MF stages with diafiltration between stages if no serum protein were rejected by the membrane. At the same flux, retentate protein concentration, and average cross-flow velocity, 4-mm membranes require 21% more energy to remove a given amount of permeate than 6-mm membranes, despite the lower surface area of the 6-mm membranes. Equations to predict skim milk MF retentate viscosity as a function of protein concentration and temperature are provided. Retentate viscosity, retentate recirculation pump frequency required to maintain a given cross-flow velocity at a given retentate viscosity, and retentate protein

  16. A strategic approach to employee retention.

    Science.gov (United States)

    Gering, John; Conner, John

    2002-11-01

    A sound retention strategy should incorporate a business plan, a value proposition, progress measures, and management influences. The business plan will indicate whether a healthcare organization will achieve a return on investment for its effort. A value proposition will showcase an organization's strengths and differentiate it from its competitors. Measuring progress toward meeting retention goals at regular intervals will help keep an organization on track. The best managers require accountability, rewarding employees for their successes and taking corrective action as necessary. Retention rate targets must be at a level that will achieve a competitive advantage in the served market.

  17. Sex differences in learning processes of classical and operant conditioning.

    Science.gov (United States)

    Dalla, Christina; Shors, Tracey J

    2009-05-25

    Males and females learn and remember differently at different times in their lives. These differences occur in most species, from invertebrates to humans. We review here sex differences as they occur in laboratory rodent species. We focus on classical and operant conditioning paradigms, including classical eyeblink conditioning, fear-conditioning, active avoidance and conditioned taste aversion. Sex differences have been reported during acquisition, retention and extinction in most of these paradigms. In general, females perform better than males in the classical eyeblink conditioning, in fear-potentiated startle and in most operant conditioning tasks, such as the active avoidance test. However, in the classical fear-conditioning paradigm, in certain lever-pressing paradigms and in the conditioned taste aversion, males outperform females or are more resistant to extinction. Most sex differences in conditioning are dependent on organizational effects of gonadal hormones during early development of the brain, in addition to modulation by activational effects during puberty and adulthood. Critically, sex differences in performance account for some of the reported effects on learning and these are discussed throughout the review. Because so many mental disorders are more prevalent in one sex than the other, it is important to consider sex differences in learning when applying animal models of learning for these disorders. Finally, we discuss how sex differences in learning continue to alter the brain throughout the lifespan. Thus, sex differences in learning are not only mediated by sex differences in the brain, but also contribute to them.

  18. Employee retention and integrated disability management practices as demand side factors.

    Science.gov (United States)

    Habeck, Rochelle; Hunt, Allan; Rachel, Colleen Head; Kregel, John; Chan, Fong

    2010-12-01

    Demand-side employment research on company policies and practices related to retention and absence and disability management (ADM) can contribute to our understanding of employment issues related to people with disabilities from the employers' perspective. To examine company ADM and retention practices and their effectiveness, as well as how these company policies and practices might influence hiring of people with disabilities. Disability Management Employer Coalition employer members (N = 650) were surveyed by internet and the survey data were analyzed using descriptive statistics, correlation, and multiple regression. Ninety-five participants responded to the survey resulting in a response rate of 14%. Retention practice was found to be associated with retention effectiveness (r = .39, P employees at every level, seeking the ideas and involvement of employees, and assuring they know how their work and performance support the mission. ADM practice was related to improving health and managing health conditions (r = .26, P employee-oriented culture (r = .23), safety/risk prevention (r = .21), and very early intervention (r = .21) correlated with delaying/preventing employment exits related to health impairment. Retention practice, ADM practice, retention effectiveness, ADM effectiveness and disability attitudes comprised a model to predict the hiring of people with disabilities. The six-predictor model was significant, F(6, 86) = 13.54, P employees who develop potentially disabling conditions; but they are not directly connected to hiring people with disabilities. These appear to be two different policy and practice issues within most companies.

  19. Spatial and temporal distributions of migration in bio-retention systems

    Directory of Open Access Journals (Sweden)

    Li Yu-Qi

    2014-01-01

    Full Text Available Urban bio-retention system is meaningful in reducing rainfall runoff and enhancing infiltration capacity. But the moisture migration in bio-retention systems are not clear under climate change. The spatial and temporal distribution of moisture under different rainfall events in bio-retention systems are studied in this paper based on experimental data in Beijing. Richards model is introduced to simulate the spatial and temporal distribution of moisture including pressure head, hydraulic head and water content under different initial and boundary conditions. As a result, we found that from the depth of the node to the lower boundary, the values of pressure head and hydraulic head increase with depth and decrease with time, while the values of water content represent opposite trends relative to the distribution of pressure head and hydraulic head in bio-retention systems.

  20. Self-Learning and Independent Study And Their Role In Learning Retention Of Physical Education Graduates

    Directory of Open Access Journals (Sweden)

    S.H. Mousavi

    2011-10-01

    Full Text Available New ways of Education focus on transferring learning responsibility tothe learner rather than teacher.Self -Learning and independent study is one of the active learning ways in which sustainability learning(retention is effectively achieved in some subjects and courses. Thestudy was quasi-experimental study aimed to evaluate the effect ofindividual learning and learning retention of graduates in physicaleducation. Information was gathered through eight questions on thepackage (240 questions and the statistical population included graduates of physical education in state universities in second semester-2008-2011. The results showed that in general, independent study and self-learning would be effective in graduates` learning retention and those who had studied under individual training and education conditions had a higher retention level.

  1. Sleep physiology predicts memory retention after reactivation

    National Research Council Canada - National Science Library

    Macdonald, Kevin J; Cote, Kimberly A

    2016-01-01

    ...) received reminders designed to leave these memories in a stable state. No significant differences in memory retention were found between blocks or groups the following morning. Frontal delta (0.5–4 Hz...

  2. International perspectives on retention and persistence

    Directory of Open Access Journals (Sweden)

    Gary Burkholder

    2014-06-01

    Full Text Available Access to higher education globally is increasing dramatically; attainment of tertiary degrees is a high priority, as educational attainment is associated with increased personal incomes as well as growth of the middle class in developing countries. The purpose of this essay is to briefly examine retention and persistence issues from a global perspective, review some retention strategies that have been employed at schools outside the United States, and to identify several key factors that related to retention and persistence globally, including access, infrastructure, financial consideration, and readiness for tertiary education.  There exists an opportunity to utilize knowledge gained in the evolution of the higher education system in the United States to help address the problems associated with retention and persistence.   DOI: 10.18870/hlrc.v4i2.208

  3. Employee Retention Strategies And Organizational Performance ...

    African Journals Online (AJOL)

    The study empirically examines the relationship between employee retention ... in form of enhanced and regular monthly Salary package, workers participation in ... and provision of incentives that bothers on staff family welfare retains and ...

  4. Retention practices in education human resources management ...

    African Journals Online (AJOL)

    The review of retention practices for teachers is premised on the principles of quality ... of business principles and public service management principles based on legal and statutory provision. An increase in customer satisfaction is necessary.

  5. Spinal morphine anesthesia and urinary retention.

    Science.gov (United States)

    Mahan, K T; Wang, J

    1993-11-01

    Spinal anesthetic is a common form of surgical anesthetic used in foot and ankle surgery. Spinal morphine anesthetic is less common, but has the advantage of providing postoperative analgesia for 12 to 24 hr. A number of complications can occur with spinal anesthesia, including urinary retention that may be a source of severe and often prolonged discomfort and pain for the patient. Management of this problem may require repeated bladder catheterization, which may lead to urinary tract infections or impairment of urethrovesicular function. This study reviews the incidence of urinary retention in 80 patients (40 after general anesthesia and 40 after spinal anesthesia) who underwent foot and ankle surgery at Saint Joseph's Hospital, Philadelphia, PA. Twenty-five percent of the patients who had spinal anesthesia experienced urinary retention, while only 7 1/2% of the group who had general anesthesia had this complication. Predisposing factors, treatment regimen, and recommendations for the prevention and management of urinary retention are presented.

  6. Deuterium retention in tungsten under combined high cycle ELM-like heat loads and steady-state plasma exposure

    Directory of Open Access Journals (Sweden)

    A. Huber

    2016-12-01

    Enhanced blister formation has been observed under combined loading conditions at power densities close to the threshold for damaging. It is shown that blisters are not mainly responsible for the pronounced increase of the D retention.

  7. Best practices in doctoral retention: Mentoring

    OpenAIRE

    Brill, Judie L.; Balcanoff, Karen K.; Denise Land; Maurice Gogarty; Freda Turner

    2014-01-01

    The aim of this critical literature review is to outline best practices in doctoral retention and the successful approach of one university to improve graduation success by providing effective mentorship for faculty and students alike. The focus of this literature review is on distance learning relationships between faculty and doctoral students, regarding retention, persistence, and mentoring models. Key phrases and words used in the search and focusing on mentoring resulted in over 20,000 s...

  8. Environmental Effects on Data Retention in Flash Cells

    Science.gov (United States)

    Katz, Rich; Flowers, David; Bergevin, Keith

    2017-01-01

    Flash technology is being utilized in fuzed munition applications and, based on the development of digital logic devices in the commercial world, usage of flash technology will increase. Antifuse technology, prevalent in non-volatile field programmable gate arrays (FPGAs), will eventually be phased out as new devices have not been developed for approximately a decade. The reliance on flash technology presents a long-term reliability issue for both DoD and NASA safety- and mission-critical applications. A thorough understanding of the data retention failure modes and statistics associated with Flash data retention is of vital concern to the fuze safety community. A key retention parameter for a flash cell is the threshold voltage (VTH), which is an indirect indicator of the amount of charge stored on the cells floating gate. This paper will present the results of our on-going tests: long-term storage at 150 C for a small population of devices, neutron radiation exposure, electrostatic discharge (ESD) testing, and the trends of large populations (over 300 devices for each condition) exposed to three difference temperatures: 25 C, 125 C, and 150 C.

  9. Simulating retention in gas-liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Martin, M.G.; Siepmann, J.I.; Schure, M.R.

    1999-12-16

    Accurate predictions of retention times, retention indices, and partition constants are a long sought-after goal for theoretical studies in chromatography. Configurational-bias Monte Carlo (CBMC) simulations in the Gibbs ensemble using the transferable potentials for phase equilibria-united atom (TraPPE-UA) force field have been carried out to obtain a microscopic picture of the partitioning of 10 alkane isomers between a helium vapor phase and a squalane liquid phase, a protypical gas-liquid chromatography system. The alkane solutes include some topological isomers that differ only in the arrangement of their building blocks (e.g., 2,5-dimethylhexane and 3,4-dimethylhexane), for which the prediction of the retention order is particularly difficult. The Kovats retention indices, a measure of the relative retention times, are calculated directly from the partition constants and are in good agreement with experimental values. The calculated Gibbs free energies of transfer for the normal alkanes conform to Martin's equation which is the basis of linear free energy relationships used in many process modeling packages. Analysis of radial distribution functions and the corresponding energy integrals does not yield evidence for specific retention structures and shows that the internal energy of solvation is not the main driving force for the separation of topological isomers in this system.

  10. Retention Benefit Based Intelligent Cache Replacement

    Institute of Scientific and Technical Information of China (English)

    李凌达; 陆俊林; 程旭

    2014-01-01

    The performance loss resulting from different cache misses is variable in modern systems for two reasons: 1) memory access latency is not uniform, and 2) the latency toleration ability of processor cores varies across different misses. Compared with parallel misses and store misses, isolated fetch and load misses are more costly. The variation of cache miss penalty suggests that the cache replacement policy should take it into account. To that end, first, we propose the notion of retention benefit. Retention benefits can evaluate not only the increment of processor stall cycles on cache misses, but also the reduction of processor stall cycles due to cache hits. Then, we propose Retention Benefit Based Replacement (RBR) which aims to maximize the aggregate retention benefits of blocks reserved in the cache. RBR keeps track of the total retention benefit for each block in the cache, and it preferentially evicts the block with the minimum total retention benefit on replacement. The evaluation shows that RBR can improve cache performance significantly in both single-core and multi-core environment while requiring a low storage overhead. It also outperforms other state-of-the-art techniques.

  11. Best practices in doctoral retention: Mentoring

    Directory of Open Access Journals (Sweden)

    Judie L. Brill

    2014-06-01

    Full Text Available The aim of this critical literature review is to outline best practices in doctoral retention and the successful approach of one university to improve graduation success by providing effective mentorship for faculty and students alike. The focus of this literature review is on distance learning relationships between faculty and doctoral students, regarding retention, persistence, and mentoring models. Key phrases and words used in the search and focusing on mentoring resulted in over 20,000 sources. The search was narrowed to include only doctoral study and mentoring. Research questions of interest were: Why do high attrition rates exist for doctoral students? What are the barriers to retention? What are the benefits of doctoral mentoring? What programs do institutions have in place to reduce attrition? The researchers found a key factor influencing doctoral student retention and success is effective faculty mentorship. In particular, the design of a mentoring and faculty training program to increase retention and provide for success after graduation is important. This research represents a key area of interest in the retention literature, as institutions continue to search for ways to better support students during their doctoral programs and post-graduation. DOI: 10.18870/hlrc.v4i2.186

  12. Water retention behaviour of compacted bentonites: experimental observations and constitutive model

    Directory of Open Access Journals (Sweden)

    Dieudonne Anne-Catherine

    2016-01-01

    Full Text Available Bentonite-based materials are studied as potential barriers for the geological disposal of radioactive waste. In this context, the hydro-mechanical behaviour of the engineered barrier is first characterized by free swelling conditions followed by constant volume conditions. This paper presents an experimental study conducted in order to characterize the water retention behaviour of a compacted MX-80 bentonite/sand mixture. Then, based on observations of the material double structure and the water retention mechanisms in compacted bentonites, a new water retention model is proposed. The model considers adsorbed water in the microstructure and capillary water in the aggregate-porosity. The model is calibrated and validated against the experimental data. It is used for better understanding competing effects between volume change and water uptake observed during hydration under free swelling conditions.

  13. Colloid retention mechanisms in single, saturated, variable-aperture fractures.

    Science.gov (United States)

    Rodrigues, S N; Dickson, S E; Qu, J

    2013-01-01

    The characterization of fractured aquifers is commonly limited to the methodologies developed for unconsolidated porous media aquifers, which results in many uncertainties. Recent work indicates that fractured rocks remove more particulates than they are conventionally credited for. This research was designed to quantify the number of Escherichia coli RS2-GFP retained in single, saturated, variable-aperture fractures extracted from the natural environment. Conservative solute and E. coli RS2-GFP tracer experiments were used to elucidate the relationships between dominant retention mechanisms, aperture field characteristics, and flow rate. A non-destructive method of determining a surrogate measure of a coefficient of variation (COV(S)) for each fracture was used to better understand the transport behaviour of E. coli RS2-GFP. The results from this research all point to the importance of aperture field characterization in understanding the fate and transport of contaminants in fractured aquifers. The mean aperture was a very important characteristic in determining particulate recovery, so were matrix properties, COV(s), and flow rate. It was also determined that attachment is a much more significant retention mechanism than straining under the conditions employed in this research. Finally, it was demonstrated that the dominant retention mechanism in a fracture varies depending on the specific discharge. An improved understanding of the mechanisms that influence the fate and transport of contaminants through fractures will lead to the development of better tools and methodologies for the characterization of fractured aquifers, as well as the ability to manipulate the relevant mechanisms to increase or decrease retention, depending on the application.

  14. Retention systems for extraoral maxillofacial prosthetic implants: a critical review.

    Science.gov (United States)

    Cobein, M V; Coto, N P; Crivello Junior, O; Lemos, J B D; Vieira, L M; Pimentel, M L; Byrne, H J; Dias, R B

    2017-05-25

    We describe the techniques available for retention of implant-supported prostheses: bar-clips, O-rings, and magnets. We present reported preferences and, although this is limited by the heterogeneity of methods used and patients studied, we hope we have identified the best retention systems for maxillofacial prosthetic implants. If practitioners know the advantages and disadvantages of each system, they can choose the most natural and comfortable prosthesis. We searched the PubMed and Scopus databases, and restricted our search to papers published 2001-13. MeSH terms used were Maxillofacial prosthesis and Craniofacial prosthesis OR Craniofacial prostheses. We found a total of 2630 papers, and after duplicates had been removed we analysed the rest and found 25 papers for review. Of these, 12 were excluded because they were case reports or non-systematic reviews. Of the remaining 13, 10 described group analyses and seemed appropriate to find practitioner's choices, as cited in the abstract (n=1611 prostheses). Three papers did not mention the type of prosthetic connection used, so were excluded. The most popular choices for different conditions were analysed, though the sites and retention systems were not specified in all 10 papers. The bar-clip system was the most used in auricular (6/10 papers) and nasal prostheses (4/10). For the orbital region, 6/10 favoured magnets. Non-osseointegrated mechanical or adhesive retention techniques are the least expensive and have no contraindications. When osseointegrated implants are possible, each facial region has a favoured system. The choice of system is influenced by two factors: standard practice and the abilities of the maxillofacial surgeon and maxillofacial prosthetist. Copyright © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  15. Rainwater runoff retention on an aged intensive green roof.

    Science.gov (United States)

    Speak, A F; Rothwell, J J; Lindley, S J; Smith, C L

    2013-09-01

    Urban areas are characterised by large proportions of impervious surfaces which increases rainwater runoff and the potential for surface water flooding. Increased precipitation is predicted under current climate change projections, which will put further pressure on urban populations and infrastructure. Roof greening can be used within flood mitigation schemes to restore the urban hydrological balance of cities. Intensive green roofs, with their deeper substrates and higher plant biomass, are able to retain greater quantities of runoff, and there is a need for more studies on this less common type of green roof which also investigate the effect of factors such as age and vegetation composition. Runoff quantities from an aged intensive green roof in Manchester, UK, were analysed for 69 rainfall events, and compared to those on an adjacent paved roof. Average retention was 65.7% on the green roof and 33.6% on the bare roof. A comprehensive soil classification revealed the substrate, a mineral soil, to be in good general condition and also high in organic matter content which can increase the water holding capacity of soils. Large variation in the retention data made the use of predictive regression models unfeasible. This variation arose from complex interactions between Antecedant Dry Weather Period (ADWP), season, monthly weather trends, and rainfall duration, quantity and peak intensity. However, significantly lower retention was seen for high rainfall events, and in autumn, which had above average rainfall. The study period only covers one unusually wet year, so a longer study may uncover relationships to factors which can be applied to intensive roofs elsewhere. Annual rainfall retention for Manchester city centre could be increased by 2.3% by a 10% increase in intensive green roof construction. The results of this study will be of particular interest to practitioners implementing greenspace adaptation in temperate and cool maritime climates.

  16. Causes and implications of colloid and microorganism retention hysteresis

    Science.gov (United States)

    Bradford, Scott A.; Kim, Hyunjung

    2012-09-01

    Experiments were designed to better understand the causes and implications of colloid and microorganism retention hysteresis with transients in solution ionic strength (IS). Saturated packed column experiments were conducted using two sizes of carboxyl modified latex (CML) microspheres (0.1 and 1.1 μm) and microorganisms (coliphage φX174 and E. coli D21g) under various transient solution chemistry conditions, and 360 μm Ottawa sand that was subject to different levels of cleaning, namely, a salt cleaning procedure that removed clay particles, and a salt + acid cleaning procedure that removed clay and reduced microscopic heterogeneities due to metal oxides and surface roughness. Comparison of results from the salt and salt + acid treated sand indicated that microscopic heterogeneity was a major contributor to colloid retention hysteresis. The influence of this heterogeneity increased with IS and decreasing colloid/microbe size on salt treated sand. These trends were not consistent with calculated mean interaction energies (the secondary minima), but could be explained by the size of the electrostatic zone of influence (ZOI) near microscopic heterogeneities. In particular, the depth of local minima in the interaction energy has been predicted to increase with a decrease in the ZOI when the colloid size and/or the Debye length decreased (IS increased). The adhesive interaction was therefore largely irreversible for smaller sized 0.1 μm CML colloids, whereas it was reversible for larger 1.1 μm CML colloids. Similarly, the larger E. coli D21g exhibited greater reversibility in retention than φX174. However, direct comparison of CML colloids and microbes was not possible due to differences in size, shape, and surface properties. Retention and release behavior of CML colloids on salt + acid treated sand was much more consistent with mean interaction energies due to reduction in microscopic heterogeneities.

  17. Deuterium retention in tungsten exposed to mixed D + N plasma at divertor relevant fluxes in Magnum-PSI

    Science.gov (United States)

    Lee, H. T.; De Temmerman, G.; Gao, L.; Schwarz-Selinger, T.; Meisl, G.; Höschen, T.; Ueda, Y.

    2015-08-01

    Nitrogen (N) has been proposed as an extrinsic impurity species in the divertor to reduce the local power load onto tungsten (W) plasma-facing components. Laboratory studies at low incident fluxes have indicated N increases deuterium (D) retention in tungsten. Here we show that W exposed to D + N Magnum-PSI plasmas under divertor relevant particle fluxes (∼1024 D/m2 s), also results in an increase in D retention by enhanced near surface trapping up to 1100 K due either to N or Mo impurities, and increased retention in the bulk at T > 700 K. These results demonstrate that N or Mo surface impurities have the potential to alter the tritium inventory in tungsten plasma-facing components under diverter relevant particle fluxes by affecting surface and bulk retention processes.

  18. Deuterium retention in tungsten exposed to mixed D + N plasma at divertor relevant fluxes in Magnum-PSI

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H.T., E-mail: heunlee@wakate.frc.eng.osaka-u.ac.jp [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan); De Temmerman, G. [Dutch Institute for Fundamental Energy Research, Nieuwegein, 3439 MN (Netherlands); Gao, L.; Schwarz-Selinger, T.; Meisl, G.; Höschen, T. [Max-Planck-Institut für Plasmaphysik, D-85748 Garching (Germany); Ueda, Y. [Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan)

    2015-08-15

    Nitrogen (N) has been proposed as an extrinsic impurity species in the divertor to reduce the local power load onto tungsten (W) plasma-facing components. Laboratory studies at low incident fluxes have indicated N increases deuterium (D) retention in tungsten. Here we show that W exposed to D + N Magnum-PSI plasmas under divertor relevant particle fluxes (∼10{sup 24} D/m{sup 2} s), also results in an increase in D retention by enhanced near surface trapping up to 1100 K due either to N or Mo impurities, and increased retention in the bulk at T > 700 K. These results demonstrate that N or Mo surface impurities have the potential to alter the tritium inventory in tungsten plasma-facing components under diverter relevant particle fluxes by affecting surface and bulk retention processes.

  19. Effect of concentration, homogenization and stabilizing salts on heat stability and rheological properties of cow skim milk ultrafiltered retentate.

    Science.gov (United States)

    Meena, Ganga Sahay; Singh, Ashish Kumar; Borad, Sanket; Panjagari, Narender Raju

    2016-11-01

    Ultrafiltration (UF) of skimmed milk altered the composition of UF retentate and decreased the heat stability. Heat stability further reduced upon its subsequent homogenization or diafiltration. Poor heat stability of UF retentate restricts its processing at elevated temperatures. Therefore, this study was aimed to investigate the effect of protein concentration, homogenization and addition of stabilizing salts on the heat stability and rheological properties of UF retentates. Changes in the heat stability of fivefold homogenized UF retentate (5× HUFR) was studied in the pH range of 6.1-7.0. Disodium phosphate and trisodium citrate significantly increased the heat coagulation time (HCT) from 1.45 min (pH 6.41) to 120 min (at pH 6.5, 6.6, 7.0) and 80 min (pH 6.6), respectively. Significant reduction in ζ-potential of UF retentates was observed with an increase in calcium and reduction in pH during UF process. Rheological behaviour of retentates above threefold concentration exhibited Herschel-Bulkley behavior with linear increase in flow behavior index (n). Changes in the viscosity of the homogenized retentates were measured at the respective pH of maximum heat stability as a function of temperature (20-80 °C). Promising approaches that might improve the heat stability, solubility and other functional properties of protein rich powders have been discussed in this article.

  20. 5 CFR 575.309 - Payment of retention incentives.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Payment of retention incentives. 575.309... RECRUITMENT, RELOCATION, AND RETENTION INCENTIVES; SUPERVISORY DIFFERENTIALS; AND EXTENDED ASSIGNMENT INCENTIVES Retention Incentives § 575.309 Payment of retention incentives. (a) An authorized agency official...

  1. 5 CFR 575.306 - Authorizing a retention incentive.

    Science.gov (United States)

    2010-01-01

    ... a retention incentive; (2) Determine when a group or category of employees has unusually high or... in the absence of a retention incentive; (3) Approve a retention incentive for an employee (or group... the limitation on the maximum amount of a retention incentive for an employee (or group or category of...

  2. Effect of substituents on prediction of TLC retention of tetra-dentate Schiff bases and their Copper(II) and Nickel(II) complexes.

    Science.gov (United States)

    Stevanović, Nikola R; Perušković, Danica S; Gašić, Uroš M; Antunović, Vesna R; Lolić, Aleksandar Đ; Baošić, Rada M

    2017-03-01

    The objectives of this study were to gain insights into structure-retention relationships and to propose the model to estimating their retention. Chromatographic investigation of series of 36 Schiff bases and their copper(II) and nickel(II) complexes was performed under both normal- and reverse-phase conditions. Chemical structures of the compounds were characterized by molecular descriptors which are calculated from the structure and related to the chromatographic retention parameters by multiple linear regression analysis. Effects of chelation on retention parameters of investigated compounds, under normal- and reverse-phase chromatographic conditions, were analyzed by principal component analysis, quantitative structure-retention relationship and quantitative structure-activity relationship models were developed on the basis of theoretical molecular descriptors, calculated exclusively from molecular structure, and parameters of retention and lipophilicity. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Water retention curves and thermal insulating properties of Thermosand

    Science.gov (United States)

    Leibniz, Otto; Winkler, Gerfried; Birk, Steffen

    2010-05-01

    The heat loss and the efficiency of isolating material surrounding heat supply pipes are essential issues for the energy budget of heat supply pipe lines. Until now heat loss from the pipe is minimized by enlarging the polyurethane (PU) - insulation thickness around the pipe. As a new approach to minimize the heat loss a thermally insulating bedding material was developed and investigated. Conventional bedding sands cover all necessary soil mechanical properties, but have a high thermal conductivity from λ =1,5 to 1,7 W/(m K). A newly developed embedding material 'Thermosand' shows thermal properties from λ=0,18 W/(m K) (dry) up to 0,88 W/(m K) (wet). The raw material originates from the waste rock stockpiles of a coal mine near Fohnsdorf, Austria. With high temperatures up to nearly 1000 ° C and a special mineral mixture, a natural burned reddish material resembling clinker arises. The soilmechanical properties of Thermosand has been thoroughly investigated with laboratory testing and in situ investigations to determine compaction-, permeability- and shear-behaviour, stiffness and corresponding physical parameters. Test trenches along operational heat pipes with temperature-measurement along several cross-sections were constructed to compare conventional embedding materials with 'Thermosand'. To investigate the influence of varying moisture content on thermal conductivity a 1:1 large scale model test in the laboratory to simulate real insitu-conditions was established. Based on this model it is planned to develop numerical simulations concerning varying moisture contents and unsaturated soil mechanics with heat propagation, including the drying out of the soil during heat input. These simulations require the knowledge about the water retention properties of the material. Thus, water retention curves were measured using both steady-state tension and pressure techniques and the simplified evaporation method. The steady-state method employs a tension table (sand

  4. STUDY ON A NEW NONIONIC MICRIOPARTICLE RETENTION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Xiuwu Hou; Xiaofan Zhou; Rui Peng; Fei Wang

    2004-01-01

    The retention and drainage performances of microparticle retention system were studied in this paper, through measuring the improvement of beaten degree and retention ratio of slurry. The effects the retention system on paper sheet were discussed by measuring physical properties of paper. Compared with the influence of Hydrocol system (CPAM/bentonite) on the aspects of retention aid and drainage properties as well as increased product cost per ton paper, the developed nonionic system has some superiority and better practicability.

  5. Prediction of peptide retention times in high-pressure liquid chromatography on the basis of amino acid composition.

    Science.gov (United States)

    Meek, J L

    1980-03-01

    Analysis of peptides by reverse-phase high-pressure liquid chromatography would be simplified if retention times could be predicted by summing the contribution to retention of each of the peptide's amino acid side chains. This paper describes the derivation of values ("retention coefficients") that represent the contribution to retention of each of the common amino acids and end groups. Peptide retention times were determined on a Bio-Rad "ODS" column at room temperature with a linear gradient from 0.1 M NaclO(4), pH 7.4 or 2.1, at 0 min to 60% acetonitrile/0.1 M NaclO(4) at 80 min. The NaclO(4), a chaotropic agent, was added to improve peak shape and to minimize conformational effects. Retention coefficients for the amino acids were computed by using a Hewlett-Packard 9815A calculator programmed to change the retention coefficients for all amino acids sequentially to obtain a maximum correlation between actual and predicted retention times. Correlations of 0.999 at pH 7.4 and 0.997 at pH 2.1 were obtained for 25 peptides including glucagon, oxytocin, [Met]enkephalin, neurotensin, and somatostatin. This high degree of correlation suggests that, for peptides containing up to 20 residues, retention is primarily due to partition processes that involve all the residues. Although steric or conformational factors do have some effect on retention, the data suggest that under the above chromatographic conditions the retention of peptides containing up to 20 residues can be predicted solely on the basis of their amino acid composition. This possibility was tested by using data taken from the literature.

  6. Storm Water Retention on Three Green Roofs with Distinct Climates

    Science.gov (United States)

    Breach, P. A.; Sims, A.; O'Carroll, D. M.; Robinson, C. E.; Smart, C. C.; Powers, B. S. C.

    2014-12-01

    As urbanization continues to increase the impact of cities on their surrounding environments, the feasibility of implementing low-impact development such as green roofs is of increasing interest. Green roofs retain and attenuate storm water thereby reducing the load on urban sewer systems. In addition, green roofs can provide insulation and lower roof surface temperature leading to a decrease in building energy load. Green roof technology in North American urban environments remains underused, in part due to a lack of climate appropriate green roof design guidelines. The capacity of a green roof to moderate runoff depends on the storage capacity of the growing medium at the start of a rainfall event. Storage capacity is finite, which makes rapid drainage and evapotranspiration loss critical for maximizing storage capacity between subsequent storms. Here the retention and attenuation of storm events are quantified for experimental green roof sites located in three representative Canadian climates corresponding to; semiarid conditions in Calgary, Alberta, moderate conditions in London, Ontario, and cool and humid conditions in Halifax, Nova Scotia. The storage recovery and storm water retention at each site is modelled using a modified water balance approach. Components of the water balance including evapotranspiration are predicted using climate data collected from 2012 to 2014 at each of the experimental sites. During the measurement period there were over 300 precipitation events ranging from small, frequent events (green roofs in their respective climates.

  7. Comparison between the Requirements of Flowability and Moldability and the Shape Retention of PIM Compacts during Debinding Process

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    To successfully employ powder injection molding (PIM) as a manufacturing technique, the function of the component, design of the part, material and process should be optimized for overall processing ability of the PIM process. A comparison between the requirements of flowability and moldability and the compacts shape retention has been made in this work. There is often a contradiction between the requirements of flowability and the compacts shape retention. Many works have been done to attain good molding conditions. However, they fail to take into accountthe effect of some factors that satisfies good molding conditions on the compacts shape reten-tion during debinding. This paper studies the effect of the powder-binder mixture characteristicsand the molding conditions on the flowability and moldability and the shape retention of PIM compacts during debinding process so as to attain the benefits of each.

  8. Nursing Student Retention in Associate Degree Nursing Programs Utilizing a Retention Specialist

    Science.gov (United States)

    Schrum, Ronna A.

    2014-01-01

    The purpose of this study was to examine specific variables associated with nursing student retention in Associate Degree Nursing (ADN) Programs. Jeffreys (2004) Nursing Undergraduate Retention and Success (NURS) conceptual model provided the framework for this descriptive correlational study. One hundred sixty eight pre-licensure associate degree…

  9. Retention of Fiber and Cast Posts with Different Lengths:A Comparative Study

    Directory of Open Access Journals (Sweden)

    Z. Khamverdi

    2007-12-01

    Full Text Available Objective: There is no definitive data on the strength of glass fiber and cast posts with different length. This in vitro study was designed to investigate and compare the effect of length on the retentive strength of glass fiber and cast posts.Materials and Methods: Sixty recently extracted intact maxillary canine teeth were cut 1 mm above the CEJ. The specimens were endodontically treated and randomly divided into four groups (n=15. Specimens in groups FP(9 and FP(12 were prepared using Fiber postwith 9 and 12 mm in length while groups CP(9 and CP(12 used cast post with 9 and 12 mm length respectively. The force required to dislodge each post was recorded as retentive strength. Collected data were statistically analyzed using two-way ANOVA and post-hoctests (α=5%.Results: The mean retentive strength of groups FP(9, FP(12, CP(9 and CP(12 were 203.74 (SD=38.46, 324.54 (SD=42.92, 156.82 (SD=32.69, and 210.73 (SD=54.60 respectively.The results revealed a significant difference among retention values of tested groups, except for the FP(9 and CP(12 (P<0.05.Conclusion: Under the condition of this study, the retention of fiber posts was significantly more than cast posts with the same length. On the other hand, post length seems to have an impact on the retention of fiber and cast posts.

  10. Effects of receptor-mediated endocytosis and tubular protein composition on volume retention in experimental glomerulonephritis

    DEFF Research Database (Denmark)

    Kastner, Christian; Pohl, Marcus; Sendeski, Mauricio

    2009-01-01

    Human glomerulonephritis (GN) is characterized by sustained proteinuria, sodium retention, hypertension, and edema formation. Increasing quantities of filtered protein enter the renal tubule, where they may alter epithelial transport functions. Exaggerated endocytosis and consequent protein overl...... mechanism of channel activation which may involve the action of filtered plasma proteases....... and channels involved in volume regulation were altered in GN, and 2) proximal tubular endocytosis may influence locally as well as downstream expressed tubular transporters and channels. Effects of anti-glomerular basement membrane GN were studied in controls and megalin-deficient mice with blunted proximal...

  11. Employee retention: a customer service approach.

    Science.gov (United States)

    Gerson, Richard F

    2002-01-01

    Employee retention is a huge problem. There are staff shortages in radiology because not enough people are entering the profession; too many people are leaving the profession for retirement, higher-paying jobs or jobs with less stress; and there are not enough opportunities for career advancement. Staff shortages are exacerbated by difficulty in retaining people who enter the profession. While much work has been focused on recruitment and getting more people "in the front door," I suggest that the bulk of future efforts be focused on employee retention and "closing the back door." Employee retention must be an ongoing process, not a program. Approaches to employee retention that focus on external things, i.e., things that the company can do to or for the employee, generally are not successful. The truth is that employee retention processes must focus on what the employee gets out of the job. The process must be a benefits-based approach that helps employees answer the question, "What's in it for me?" The retention processes must be ongoing and integrated into the daily culture of the company. The best way to keep your employees is to treat them like customers. Customer service works for external customers. We treat them nicely. We work to satisfy them. We help them achieve their goals. Why not do the same for our employees? If positive customer service policies and practices can satisfy and keep external customers, why not adapt these policies and practices for employees? And, there is a service/satisfaction link between employee retention and higher levels of customer satisfaction. Customers prefer dealing with the same employees over and over again. Employee turnover destroys a customer's confidence in the company. Just like a customer does not want to have to "train and educate" a new provider, they do not want to do the same for your "revolving door" employees. So, the key is to keep employees so they in turn will help you keep your customers. Because the

  12. Is there a crisis in nursing retention in New South Wales?

    Science.gov (United States)

    Doiron, Denise; Hall, Jane; Jones, Glenn

    2008-01-01

    Background There is a severe shortage of nurses in Australia. Policy makers and researchers are especially concerned that retention levels of nurses in the health workforce have worsened over the last decade. There are also concerns that rapidly growing private sector hospitals are attracting qualified nurses away from the public sector. To date no systematic analysis of trends in nursing retention rates over time has been conducted due to the lack of consistent panel data. Results A 1.4 percentage point improvement in retention has led to a 10% increase in the overall supply of nurses in NSW. There has also been a substantial aging of the workforce, due to greater retention and an increase in mature age entrants. The improvement in retention is found in all types of premises and is largest in nursing homes. There is a substantial amount of year to year movement in and out of the workforce and across premises. The shortage of nurses in public hospitals is due to a slowdown in entry rather than competition from the rapidly growing private sector hospitals. Policy Implications The finding of an improvement (rather than a worsening) in retention suggests that additional improvements may be difficult to achieve as further retention must involve individuals more and more dissatisfied with nursing relative to other opportunities. Hence policies targeting entry such as increased places in nursing programs and additional subsidies for training costs may be more effective in dealing with the workforce shortage. This is also the case for shortages in public sector hospitals as retention in nursing is found to be relatively high in this sector. However, the large amount of year to year movements across nursing jobs, especially among the younger nurses, also suggests that policies aimed at reducing job switches and increasing the number who return to nursing should also be pursued. More research is needed in understanding the relative importance of detailed working conditions

  13. Healthcare Learning Community and Student Retention

    Directory of Open Access Journals (Sweden)

    Sherryl W. Johnson, PhD

    2014-08-01

    Full Text Available Teaching, learning, and retention processes have evolved historically to include multifaceted techniques beyond the traditional lecture. This article presents related results of a study using a healthcare learning community in a southwest Georgia university. The value of novel techniques and tools in promoting student learning and retention remains under review. This study includes a healthcare learning community as a cutting-edge teaching and learning modality. The results of an introspective survey of 22 students in a learning community explore strategies to enhance culturally relevant teaching, learning, and retention. Although learning and retention studies have been conducted at numerous universities, few have included feedback from students in a healthcare learning community. Frequencies from student responses were tabulated using five thematic factors: social support, career knowledge/opportunities, academic support, networking and faculty rapport/relationship building. Of the five theme areas, social support was identified most frequently by students as a means to support their learning and retention in the university setting.

  14. [Altered states of consciousness].

    Science.gov (United States)

    Gora, E P

    2005-01-01

    The review of modern ideas concerning the altered states of consciousness is presented in this article. Various methods of entry into the altered states of consciousness are looked over. It is shown that the altered states of consciousness are insufficiently known, but important aspects of human being existence. The role of investigation of the altered states of consciousness for the creation of integrative scientific conception base is discussed.

  15. Effect of grain size on the behavior of hydrogen/helium retention in tungsten: a cluster dynamics modeling

    Science.gov (United States)

    Zhao, Zhe; Li, Yonggang; Zhang, Chuanguo; Pan, Guyue; Tang, Panfei; Zeng, Zhi

    2017-08-01

    Reducing ion retention in materials is a key factor in the management of tritium inventory, the selection of compatible plasma-facing materials (PFMs), and thus the future development of fusion reactors. In this work, by introducing the cellular sink strength of grain boundaries (GBs) into the cluster dynamics model, the behavior of hydrogen (H) and helium (He) retention in W with different grain sizes is studied under various irradiation conditions systematically. It is found that the H/He retention increases dramatically with decreasing grain size at typical service temperatures, due to the enhancement of H/He capture ratio by GBs. Generally, He retention exists in three forms: He in GBs, in dislocations and in clusters (He m V n , He n and He n I). Our further study shows that, under the irradiation of low energy and low fluence ions, the contribution of He in clusters is negligible. The total He retention is thus dominated by the competing absorption of GBs and dislocations, that is, changing from the dislocation-based to grain boundary-based retention with decreasing grain size. H retention also presents the same behavior. In view of these grain size-related behaviors of H/He retention in W, it is suggested that coarse-grained crystals should be selected for W-based PFMs in practice.

  16. The temperature and ion energy dependence of deuterium retention in lithium films

    Science.gov (United States)

    Buzi, Luxherta; Koel, Bruce E.; Skinner, Charles H.

    2016-10-01

    Lithium conditioning of plasma facing components in magnetic fusion devices has improved plasma performance and lowered hydrogen recycling. For applications of lithium in future high heat flux and long pulse duration machines it is important to understand and parameterize deuterium retention in lithium. This work presents surface science studies of deuterium retention in lithium films as a function of surface temperature, incident deuterium ion energy and flux. Initial experiments are performed on thin (3-30 ML) lithium films deposited on a single crystal molybdenum substrate to avoid effects due to grain boundaries, intrinsic defects and impurities. A monoenergetic and mass-filtered deuterium ion beam was generated in a differentially pumped Colutron ion gun. Auger electron spectroscopy and X-ray photoelectron spectroscopy were used to identify the elemental composition and temperature programmed desorption was used to measure the deuterium retention under the different conditions. Support was provided through DOE Contract Number DE-AC02-09CH11466.

  17. Foliar retention, transport and leaching of polonium-210 and lead-210

    Energy Technology Data Exchange (ETDEWEB)

    Athalye, V.V.; Mistry, K.B.

    1972-01-01

    Polonium-210 and lead-210, the long-lived daughter radionuclides of gaseous radon-222, are deposited on plant surfaces under conditions of atmospheric washout. Foliar retention, transport and leaching of these radionuclides in Red Kidney beans were investigated in nutrient culture experiments. Under identical conditions, over 90 percent of foliar applied radiolead was retained by the plant while only about 30 percent of polonium was retained. Over a 48-hr period small quantities of polonium were translocated from the treated leaflet to other parts of the plant. By comparison, radiolead was totally immobilized at the site of retention. Leachability of root absorbed radiolead from bean leaves was 20-fold greater than that of polonium. The marked differences in the extent of foliar retention, translocation and leaching of polonium and radiolead could significantly affect the levels of these long-lived radionuclides attained in plants.

  18. Retention and failure morphology of prefabricated posts

    DEFF Research Database (Denmark)

    Sahafi, Alireza; Peutzfeldt, Anne; Asmussen, Erik;

    2004-01-01

    PURPOSE: This study evaluated the effect of cement, post material, surface treatment, and shape (1) on the retention of posts luted in the root canals of extracted human teeth and (2) on the failure morphology. MATERIALS AND METHODS: Posts of titanium alloy (ParaPost XH), glass fiber (Para......Post Fiber White), and zirconia (Cerapost) received one of several surface treatments-sandblasting, CoJet treatment, application of Metalprimer II, or sandblasting followed by silane application-and were then luted in the prepared root canal of human incisors and canines (n = 10). Following water storage...... at 37 degrees C for 7 days, retention was determined by extraction of the posts. Failure morphology of extracted posts was analyzed and quantified stereomicroscopically. RESULTS: Type of luting cement, post material, and shape of post influenced the retention and failure morphology of the posts. Because...

  19. Safeguards Workforce Repatriation, Retention and Utilization

    Energy Technology Data Exchange (ETDEWEB)

    Gallucci, Nicholas [Brookhaven National Lab. (BNL), Upton, NY (United States); Poe, Sarah [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-10-01

    Brookhaven National Laboratory was tasked by NA-241 to assess the transition of former IAEA employees back to the United States, investigating the rate of retention and overall smoothness of the repatriation process among returning safeguards professionals. Upon conducting several phone interviews, study authors found that the repatriation process went smoothly for the vast majority and that workforce retention was high. However, several respondents expressed irritation over the minimal extent to which their safeguards expertise had been leveraged in their current positions. This sentiment was pervasive enough to prompt a follow-on study focusing on questions relating to the utilization rather than the retention of safeguards professionals. A second, web-based survey was conducted, soliciting responses from a larger sample pool. Results suggest that the safeguards workforce may be oversaturated, and that young professionals returning to the United States from Agency positions may soon encounter difficulties finding jobs in the field.

  20. Mercury retention, a trait of chickens

    Energy Technology Data Exchange (ETDEWEB)

    Miller, V.L.; Bearse, G.E.; Hammermeister, K.E.

    1959-01-01

    Experiments were performed in order to gain further information on the mercury retention of two strains of chickens, the reciprocal crosses of these lines and sex differences in retention. White Leghorns were selected for resistance and susceptibility to the avian leukosis complex. Approximately 6 males and 6 females from each of the strains and reciprocal crosses were injected in the breast muscle with phenylmercury acetate at the rate of 3.0 mg. mercury per kg. body weight. The kidneys were excised and analyzed for total mercury. Results indicate that the first generation cross chicks resembled the parent that retained mercury poorly more closely than they did the one retaining large amounts of mercury. There was no significant differences between sexes in mercury retention. 4 references, 1 table.

  1. Height, Relationship Satisfaction, Jealousy, and Mate Retention

    Directory of Open Access Journals (Sweden)

    Gayle Brewer

    2009-07-01

    Full Text Available Male height is associated with high mate value. In particular, tall men are perceived as more attractive, dominant and of a higher status than shorter rivals, resulting in a greater lifetime reproductive success. Female infidelity and relationship dissolution may therefore present a greater risk to short men. It was predicted that tall men would report greater relationship satisfaction and lower jealousy and mate retention behavior than short men. Ninety eight heterosexual men in a current romantic relationship completed a questionnaire. Both linear and quadratic relationships were found between male height and relationship satisfaction, cognitive and behavioral jealousy. Tall men reported greater relationship satisfaction and lower levels of cognitive or behavioral jealousy than short men. In addition, linear and quadratic relationships were found between male height and a number of mate retention behaviors. Tall and short men engaged in different mate retention behaviors. These findings are consistent with previous research conducted in this area detailing the greater attractiveness of tall men.

  2. USAR Nurse Referral and Retention Program.

    Science.gov (United States)

    Foley, J E; Foley, B J

    1992-09-01

    In 1987, the 804th Hospital Center made alleviating the shortfall of registered nurses in the Command a priority. The Command had only 79% of its registered nurse positions filled at the time. Using the recruitment strategies of an employee referral program and a mailing list, the Command reached 100% fill in 2 years and maintained those gains for an additional year. Retention strategies were also implemented which lowered the attrition rate. This paper describes the Army Nurse Referral and Retention Program developed and implemented at the 804th Hospital Center that relieved the shortfall of registered nurses in the United States Army Reserve in New England.

  3. Nitrogen Saturation in Highly Retentive Watersheds?

    Science.gov (United States)

    Daley, M. L.; McDowell, W. H.

    2009-12-01

    Watershed managers are often concerned with minimizing the amount of N delivered to N-limited estuaries and coastal zones. A major concern is that watersheds might reach N saturation, in which N delivered to coastal zones increases due to declines in the efficiency of N retention despite constant or even reduced N inputs. We have quantified long-term changes in N inputs (atmospheric deposition, imported food and agricultural fertilizers), outputs (N concentration and export) and retention in the urbanizing Lamprey River watershed in coastal NH. Overall, the Lamprey watershed is 70% forested, receives about 13.5 kg N/ha/yr and has a high rate of annual N retention (85%). Atmospheric deposition (8.7 kg/ha/yr) is the largest N input to the watershed. Of the 2.2 kg N/ha/yr exported in the Lamprey River, dissolved organic N (DON) is the dominant form (50% of total) and it varies spatially throughout the watershed with wetland cover. Nitrate accounts for 30% of the N exported, shows a statistically significant increase from 1999 to 2009, and its spatial variability in both concentration and export is related to human population density. In sub-basins throughout the Lamprey, inorganic N retention is high (85-99%), but the efficiency of N retention declines sharply with increased human population density and associated anthropogenic N inputs. N assimilation in the vegetation, denitrification to the atmosphere and storage in the groundwater pool could all be important contributors to the current high rates of N retention. The temporal and spatial patterns that we have observed in nitrate concentration and export are driven by increases in N inputs and impervious surfaces over time, but the declining efficiency of N retention suggests that the watershed may also be reaching N saturation. The downstream receiving estuary, Great Bay, already suffers from low dissolved oxygen levels and eelgrass loss in part due to N loading from the Lamprey watershed. Targeting and reducing

  4. Retention and release of deuterium implanted in copper coatings on Al-6061

    CERN Document Server

    Inal, M Y; Kurz, K L; Cowgill, D F; Causey, R

    2000-01-01

    To mitigate the problem of retention and permeation of tritium implanted in Al-6061, the use of copper coatings was investigated. Copper coatings (having weights of 0.03, 0.06 and 0.088 kg/m sup 2) deposited on Al-6061 substrates by the RF Magnetron sputtering method were implanted with deuterium (D) in an accelerator at 350 K, and the resulting D profiles were monitored using negative SIMS and the D( sup 3 He,p) sup 4 He nuclear reaction. The retention characteristics of deuterium were subsequently studied as a function of coating weight, D sup + fluence (varied in the 1-3x10 sup 2 sup 1 D sup + /m sup 2 range) and D sup + ion energy (40 and 120 keV). Under identical implantation conditions, deuterium retention in Al-6061 was higher than in Al-6061 coated with 0.088 kg/m sup 2 Cu. In the various coatings implanted under different conditions, deuterium retention ranged between 1.2% and 5.4% of the implanted amount. The deuterium retention decreased with increasing coating weight and then leveled off with furt...

  5. EVALUATION OF WATER RETENTION CAPABILITY IN WETLANDS AT SMALL FOREST CATCHMENT

    Directory of Open Access Journals (Sweden)

    Daniel Liberacki

    2015-07-01

    Full Text Available The paper presents the results of researches carried out in the middle part of Pizza Zielonka forest complex. The aim was the evaluation of retention changes at wetlands and mid-forest ponds. The object of the study was the catchment of the Trojanka watercourse, considering from the origin to the cross-section of Zielonka Lake. The catchment is located in in the central part of the Wielkopolska region, approximatelly 20 km on the North-East of Poznań. The area of this forestall catchment is about 223 ha. In the paper an analysis of the results from three hydrological years was presented. The results of the years 1987 (wet year, 2003 (dry year and 2009 (medium year were analysed against meteorological conditions. Retention capacity in each wetlands, as well as the possibility of water retention in the Trojanka watercourse was calculated. The researches confirmed significant meteorological conditions influence the amount of retentioned water. The calculated capacity of retentioned water was 15 852 m3 considering the total area of wetland and swamp (8,58 ha and precipitation sum of 555 mm. 18% increase of water capacity was observed in wet year (1987 In this year the sum of precipitation was 100 mm higher than multiyear average sum. Meanwhile 62% decrease of water capacity was observed in dry year (2003, when the precipitation sum was 208 mm lower than multiyear average one.

  6. Network modelling of fluid retention behaviour in unsaturated soils

    Directory of Open Access Journals (Sweden)

    Athanasiadis Ignatios

    2016-01-01

    Full Text Available The paper describes discrete modelling of the retention behaviour of unsaturated porous materials. A network approach is used within a statistical volume element (SVE, suitable for subsequent use in hydro-mechanical analysis and incorporation within multi-scale numerical modelling. The soil pore structure is modelled by a network of cylindrical pipes connecting spheres, with the spheres representing soil voids and the pipes representing inter-connecting throats. The locations of pipes and spheres are determined by a Voronoi tessellation of the domain. Original aspects of the modelling include a form of periodic boundary condition implementation applied for the first time to this type of network, a new pore volume scaling technique to provide more realistic modelling and a new procedure for initiating drying or wetting paths in a network model employing periodic boundary conditions. Model simulations, employing two linear cumulative probability distributions to represent the distributions of sphere and pipe radii, are presented for the retention behaviour reported from a mercury porosimetry test on a sandstone.

  7. Suburban watershed nitrogen retention: Estimating the effectiveness of stormwater management structures

    Directory of Open Access Journals (Sweden)

    Benjamin J. Koch

    2015-07-01

    Full Text Available Abstract Excess nitrogen (N is a primary driver of freshwater and coastal eutrophication globally, and urban stormwater is a rapidly growing source of N pollution. Stormwater best management practices (BMPs are used widely to remove excess N from runoff in urban and suburban areas, and are expected to perform under a wide variety of environmental conditions. Yet the capacity of BMPs to retain excess N varies; and both the variation and the drivers thereof are largely unknown, hindering the ability of water resource managers to meet water quality targets in a cost-effective way. Here, we use structured expert judgment (SEJ, a performance-weighted method of expert elicitation, to quantify the uncertainty in BMP performance under a range of site-specific environmental conditions and to estimate the extent to which key environmental factors influence variation in BMP performance. We hypothesized that rain event frequency and magnitude, BMP type and size, and physiographic province would significantly influence the experts’ estimates of N retention by BMPs common to suburban Piedmont and Coastal Plain watersheds of the Chesapeake Bay region. Expert knowledge indicated wide uncertainty in BMP performance, with N removal efficiencies ranging from 40%. Experts believed that the amount of rain was the primary identifiable source of variability in BMP efficiency, which is relevant given climate projections of more frequent heavy rain events in the mid-Atlantic. To assess the extent to which those projected changes might alter N export from suburban BMPs and watersheds, we combined downscaled estimates of rainfall with distributions of N loads for different-sized rain events derived from our elicitation. The model predicted higher and more variable N loads under a projected future climate regime, suggesting that current BMP regulations for reducing nutrients may be inadequate in the future.

  8. Prevention and management of postoperative urinary retention after urogynecologic surgery

    Directory of Open Access Journals (Sweden)

    Geller EJ

    2014-08-01

    Full Text Available Elizabeth J Geller Division of Female Pelvic Medicine and Reconstructive Surgery, Department of Obstetrics and Gynecology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA Abstract: Postoperative urinary retention (POUR is a frequent consequence of gynecologic surgery, especially with surgical correction of urinary incontinence and pelvic organ prolapse. Estimates of retention rates after pelvic surgery range from 2.5%–43%. While there is no standard definition for POUR, it is characterized by impaired bladder emptying, with an elevation in the volume of retained urine. The key to management of POUR is early identification. All patients undergoing pelvic surgery, especially for the correction of incontinence or prolapse, should have an assessment of voiding function prior to discharge. There are several ways to assess voiding function – the gold standard is by measuring a postvoid residual. Management of POUR is fairly straightforward. The goal is to decompress the bladder to avoid long-term damage to bladder integrity and function. The decision regarding when to discontinue catheter-assisted bladder drainage in the postoperative period can be assessed in an ongoing fashion by measurement of postvoid residual. The rate of prolonged POUR beyond 4 weeks is low, and therefore most retention can be expected to resolve spontaneously within 4–6 weeks. When POUR does not resolve spontaneously, more active management may be required. Techniques include urethral dilation, sling stretching, sling incision, partial sling resection, and urethrolysis. While some risk of POUR is inevitable, there are risk factors that are modifiable. Patients that are at higher risk – either due to the procedures being performed or their clinical risk factors – should be counseled regarding the risks and management options for POUR prior to their surgery. Although POUR is a serious condition that can have serious consequences if left untreated, it

  9. Carbon dioxide retention in divers

    Energy Technology Data Exchange (ETDEWEB)

    Florio, J.T.; Mackenzie, D.A.R.; McKenzie, R.S. [ARE Physiological Laboratory, Gosport (United Kingdom)

    1998-04-01

    This report summarises the work carried out at the ARE Physiological Laboratory (ARE(PL)) between July 1978 and December 1983. The work was intended to examine the proposition that some divers have a low ventilatory response to carbon dioxide; that this results in a low ventilatory response to exercise with consequent hypercapnia; and that these characteristics put the diver at a greater-than-normal risk by increasing the individual`s susceptibility to oxygen toxicity and to other hazards associated with diving (e.g. nitrogen narcosis, decompression sickness and hypothermia). The specific aims of the project can be summarised as follows: (a) to demonstrate the existence of divers who exhibit the tendency to `retain carbon dioxide` when working in hyperbaric conditions; (b) to define the circumstances under which such individuals are at risk; (c) to assess the magnitude of the risk; and (d) to recommend ways to eliminate or to reduce the risk. (author)

  10. Modelling of Pb release during Portland cement alteration

    Energy Technology Data Exchange (ETDEWEB)

    Benard, A. [INERIS Mediterrannee, F-13545 Aix En Provence 04 (France); Rose, J.; Borschneck, D.; Bottero, J.Y. [Univ Paul Cezanne, CNRS, UMR 6635, CEREGE, IFR PMSE 112, F-13545 Aix En Provence, (France); Hazemann, J.L. [CNRS, Cristallog Lab, F-38042 Grenoble 09 (France); Proux, O. [Univ Grenoble 1, CNRS, UMR, LGIT, F-38400 St Martin Dheres (France); Trotignon, L. [CEA Cadarache, DTN, SMTM, Lab Modelisat Transferts Environm, 13 - Saint Paul lez Durance (France); Nonat, A. [Univ Bourgogne, CNRS, UMR 5613, Fac Sci Mirande, Lab Rech Reactivite Solides, F-21078 Dijon (France); Chateau, L. [ADEME, F-49004 Angers (France)

    2009-07-01

    Complex cementitious matrices undergo weathering with environmental exchange and can release metallic pollutants during alteration. The molecular mechanisms responsible for metal release are difficult to identify, though this is necessary if such processes are to be controlled. The present study determines and models the molecular mechanisms of Pb release during Portland cement leaching. As Pb release is strongly related to its speciation (i.e. atomic environment and the nature of bearing phases), the first objective of the present study was to investigate the evolution of Pb retention sites together with the evolution of the cement mineralogy during leaching. Complementary and efficient investigation tools were used, namely X-ray diffraction, micro-X-ray fluorescence and X-ray absorption fine structures. The second objective was to reproduce our results with a reactive transport code (CHESS/HYTEC) in order to test the proposed speciation model of Pb. Combined results indicate that in both the unaltered core and the altered layer of the leached cement, Pb(II) would be retained through C-S-H 'nano-structure', probably linked to a Q(1) or Q(2P) silicate tetrahedra. Moreover in the altered layer, the presence of Fe atoms in the atomic environment of Pb is highly probable. Unfortunately little is known about Fe phases in cement, which makes the interpretation difficult. Can Fe-substituted hydrogranet (C(3)AH(6)) be responsible for Pb retention? Modelling results were consistent with Pb retention through C-S-H in layers and also in an additional, possibly Fe-containing, Pb-retention phase in the altered layer. (authors)

  11. The Case for Focusing on Millennial Retention.

    Science.gov (United States)

    Koppel, Jenna; Deline, Marisa; Virkstis, Katherine

    A concern for nurse leaders is rapid turnover of engaged, early-tenure millennial nurses. In this 1st article in a 2-part series, the authors describe why leaders should supplement their organization's current investments in engagement with retention strategies targeted at millennial nurses.

  12. 5 CFR 293.511 - Retention schedule.

    Science.gov (United States)

    2010-01-01

    ... RECORDS Employee Medical File System Records § 293.511 Retention schedule. (a) Temporary EMFS records must... accordance with General Records Schedule (GRS) 1, item 21, issued by the National Archives and Records Administration (NARA). (b) Occupational Medical Records considered to be long-term records must be maintained...

  13. Studies on nitrogen retention in growing pigs

    DEFF Research Database (Denmark)

    Thorbek, G; Henckel, S; Chwalibog, André;

    1987-01-01

    Nitrogen retention (RN) was measured in 60 barrows of Danish Landrace and a total of 470 balance periods was carried out during the growth period from 20 to 85 kg live weight. In the first serie (Expt A) six different feed compounds of high biological value (HBV) were fed to 48 barrows, while...... in the second serie (Expt B) 12 barrows were measured on feed compounds of HBV or low biological value (LBV). Three different levels of gross energy were used in Expt B. Individual differences of 10-20% in the pigs capability for nitrogen retention were observed. Nitrogen retention increased from 12 to 21 g N....../d on the HBV-compounds and was not influenced by increasing nitrogen or energy intake. Nitrogen retention was curvilinear in relation to metabolic live weight (kg0.75) in both series. A parabolic function on kg0.75 gave the best fit to the data with the following regression equations: Expt A + B: RN, g/d = 1...

  14. Relationship of Personality Traits to Student Retention

    Science.gov (United States)

    Liang, John Paul

    2010-01-01

    Carl Jung's theory of psychological types has been the basis for the development of personality categorization, including tests such as Myers-Briggs Type Indicator (MBTI). This study analyzed the extent of the relationship between MBTI and Tinto (1993) retention factors that influence Oriental medicine students' choice of staying or dropping out…

  15. Relationship of Personality Traits to Student Retention

    Science.gov (United States)

    Liang, John Paul

    2010-01-01

    Carl Jung's theory of psychological types has been the basis for the development of personality categorization, including tests such as Myers-Briggs Type Indicator (MBTI). This study analyzed the extent of the relationship between MBTI and Tinto (1993) retention factors that influence Oriental medicine students' choice of staying or dropping out…

  16. Healthcare Learning Community and Student Retention

    Science.gov (United States)

    Johnson, Sherryl W.

    2014-01-01

    Teaching, learning, and retention processes have evolved historically to include multifaceted techniques beyond the traditional lecture. This article presents related results of a study using a healthcare learning community in a southwest Georgia university. The value of novel techniques and tools in promoting student learning and retention…

  17. Water retention in mushroom during sustainable processing

    NARCIS (Netherlands)

    Paudel, E.

    2015-01-01

    This thesis deals with the understanding of the water holding capacity of mushroom, in the context of a redesign of their industrial processing. For designing food process the retention of food quality is of the utmost importance. Water holding capacity is an important quality aspect of mushrooms. A

  18. Structural Information Retention in Visual Art Processing.

    Science.gov (United States)

    Koroscik, Judith Smith

    The accuracy of non-art college students' longterm retention of structural information presented in Leonardo da Vinci's "Mona Lisa" was tested. Seventeen female undergraduates viewed reproductions of the painting and copies that closely resembled structural attributes of the original. Only 3 of the 17 subjects reported having viewed a reproduction…

  19. Employee Retention: A Challenge of the Nineties.

    Science.gov (United States)

    Zeiss, Tony

    1990-01-01

    Considers ways in which community colleges can help employers implement programs to improve the work environment and retain trained workers. Presents a model for employee retention that has worked effectively in Pueblo, Colorado. Describes Pueblo Community College's cooperative program with the Wats Marketing Group to help reduce employee…

  20. 5 CFR 293.404 - Retention schedule.

    Science.gov (United States)

    2010-01-01

    ... RECORDS Employee Performance File System Records § 293.404 Retention schedule. (a)(1) Except as provided... in this system, including transfer with the employee who changes positions, shall be as agencies... performance-related documents five years old or less shall be forwarded in the Employee Performance File...

  1. Recruitment and Retention with a Spin

    Science.gov (United States)

    Lindgren, Rita; Hixson, Carla Braun

    2010-01-01

    Strategic planning and innovation at Bismarck State College (BSC) found common ground in the college's goal to recruit and retain employees in an environment of low unemployment and strong competition for skilled employees. BSC's strategic plan for 2007-09 included the objective "to increase retention of employees." One of the strategies…

  2. Managing talent retention: an ROI approach

    National Research Council Canada - National Science Library

    Phillips, Jack J; Edwards, Lisa

    2009-01-01

    .... Employee retention will continue to be an important issue for most job groups in the next decade. Unwanted talent departure continues to be one of the most unappreciated and undervalued issues facing business leaders. This stems from several important assumptions and conclusions about turnover: 1. All stakeholders involved in the issue, including human ...

  3. Water retention in mushroom during sustainable processing

    NARCIS (Netherlands)

    Paudel, E.

    2015-01-01

    This thesis deals with the understanding of the water holding capacity of mushroom, in the context of a redesign of their industrial processing. For designing food process the retention of food quality is of the utmost importance. Water holding capacity is an important quality aspect of mushrooms. A

  4. Structural Information Retention in Visual Art Processing.

    Science.gov (United States)

    Koroscik, Judith Smith

    The accuracy of non-art college students' longterm retention of structural information presented in Leonardo da Vinci's "Mona Lisa" was tested. Seventeen female undergraduates viewed reproductions of the painting and copies that closely resembled structural attributes of the original. Only 3 of the 17 subjects reported having viewed a reproduction…

  5. Tribune: Retention Policy for Ethnic Minority Students

    NARCIS (Netherlands)

    Herfs, Paul

    2003-01-01

    The question of the retention of ethnic minority university students in universities in the Netherlands, especially at the University of Utrecht, is examined. In particular, the cases of Surinamese, Antillian, and Aruban students, foreign refugee students, particularly medical doctors, and Turkish a

  6. Nigerian Federal Civil Service: Employee Recruitment, Retention ...

    African Journals Online (AJOL)

    This study delved into the recruitment and retention of employees in the ... Civil Service (NFCS), to establish their impact on the effectiveness of the service. ... the study found that the service lagged behind in providing adequate incentives to ... its application should also pay attention to the merit of prospective employees.

  7. Testing to Enhance Retention in Human Anatomy

    Science.gov (United States)

    Logan, Jessica M.; Thompson, Andrew J.; Marshak, David W.

    2011-01-01

    Recent work in cognitive psychology has shown that repeatedly testing one's knowledge is a powerful learning aid and provides substantial benefits for retention of the material. To apply this in a human anatomy course for medical students, 39 fill-in-the-blank quizzes of about 50 questions each, one for each region of the body, and four about the…

  8. Effects of Emotional Intelligence on Teacher Retention

    Science.gov (United States)

    Gerald, Grant Ronald

    2010-01-01

    This mixed methods, explanatory design study focused on determining if the emotional intelligence of principals affects the retention of new teachers. In phase one, a non-random cluster sample of 138 public school principals in the state of Louisiana was surveyed using a quantitative instrument. A Factor Analysis, Analysis of Variance (ANOVA), and…

  9. Conjoint Retention of Maps and Related Discourse.

    Science.gov (United States)

    Kulhavy, Raymond, W.; And Others

    1985-01-01

    Two experiments used fifth grade students to test the hypothesis that conjointly presented verbal/spatial information facilitates retrieval from either stimulus format. Results support the notion of conjoint retention which assumes that related verbal/spatial arrays are stored in a fashion which allows separate use of both formats during…

  10. 78 FR 57927 - Credit Risk Retention

    Science.gov (United States)

    2013-09-20

    .... Asset-Backed Commercial Paper Conduits 5. Commercial Mortgage-Backed Securities 6. Government-Sponsored... purchaser in commercial mortgage-backed securities (CMBS) transactions and an exemption that would permit... purchasers to hold risk retention in commercial mortgage-backed securitizations instead of sponsors (as...

  11. Retention--A Pseudo-Problem?

    Science.gov (United States)

    Geis, George L.

    1999-01-01

    Discusses retention of learning; training methods; maintenance issues; the effect of punishment; reinforcement; the performance environment; transfer of training; forgetting; implications for designers of instructional materials or designers of training programs; and the division between training and on-the-job performance. (LRW)

  12. Attrition and Retention among Special Education Paraprofessionals

    Science.gov (United States)

    Hall, Kimberly D.

    2009-01-01

    The purpose of the study was to obtain information about issues of turnover and retention among former and current special education paraprofessionals in one school district. Survey data and findings indicated ways to retain staff and reduce turnover. Information from this study was shared within the district and will be considered in creating…

  13. Impaired extinction of fear conditioning after REM deprivation is magnified by rearing in an enriched environment.

    Science.gov (United States)

    Hunter, Amy Silvestri

    2015-07-01

    Evidence from both human and animal studies indicates that rapid eye movement sleep (REM) is essential for the acquisition and retention of information, particularly of an emotional nature. Learning and memory can also be impacted by manipulation of housing condition such as exposure to an enriched environment (EE). This study investigated the effects of REM deprivation and EE, both separately and combined, on the extinction of conditioned fear in rats. Consistent with prior studies, conditioning was enhanced in EE-reared rats and extinction was impaired in REM deprived rats. In addition, rats exposed to both REM deprivation and EE showed the greatest impairment in extinction, with effects persisting through the first two days of extinction training. This study is the first to explore the combination of REM deprivation and EE and suggests that manipulations that alter sleep, particularly REM, can have persisting deleterious effects on emotional memory processing.

  14. Donald Campbell's Model of the Creative Process: Creativity as Blind Variation and Selective Retention.

    Science.gov (United States)

    Simonton, Dean Keith

    1998-01-01

    This introductory article discusses a blind-variation and selective-retention model of the creative process developed by Donald Campbell. According to Campbell, creativity contains three conditions: a mechanism for introducing variation, a consistent selection process, and a mechanism for preserving and reproducing selected variations. (Author/CR)

  15. Retention and remobilization of stabilized silver nanoparticles in an undisturbed loamy sand soil

    Science.gov (United States)

    Column experiments were conducted with undisturbed loamy sand soil under unsaturated conditions (around 90% saturation degree) to investigate the retention of surfactant stabilized silver nanoparticles (AgNPs) with various input concentration (Co), flow velocity, and ionic strength (IS), and the rem...

  16. Effect of Intermittent Reinforcement on Acquisition and Retention in Delayed Matching-to-Sample in Pigeons

    Science.gov (United States)

    Grant, Douglas S.

    2011-01-01

    Experiments 1 and 2 involved independent groups that received primary reinforcement after a correct match with a probability of 1.0, 0.50 or 0.25. Correct matches that did not produce primary reinforcement produced a conditioned reinforcer. Both experiments revealed little evidence that acquisition or retention was adversely affected by use of…

  17. Surface morphology and deuterium retention of tungsten after low- and high-flux deuterium plasma exposure

    NARCIS (Netherlands)

    Hoen, M. H. J. 't; Balden, M.; Manhard, A.; Mayer, M.; Elgeti, S.; Kleyn, A. W.; van Emmichoven, P. A. Zeijlma

    2014-01-01

    The surface morphology and deuterium retention were investigated of polycrystalline tungsten targets that were exposed to deuterium plasmas at widely varying conditions. By changing only one parameter at a time, the isolated effects of flux, time and pre-damaging on surface modifications and deuteri

  18. Retention of ascorbic acid in fortified orange juice powers during storage

    Directory of Open Access Journals (Sweden)

    G. S. Siddappa

    1960-10-01

    Full Text Available Both Coorg and Sathgudi orange juice powders are good carriers for added ascorbic acid during prolonged storage at ordinary temperatures. There is not much difference between nitrogen and air packs as regards retention of ascorbic acid during storage. Nitrogen pack, however, helps to keep the power in a better free-flowing condition.

  19. Moral School Building Leadership: Investigating a Praxis for Alternative Route Teacher Retention

    Science.gov (United States)

    Easley, Jacob, II

    2008-01-01

    Purpose: The purpose of this paper is to identify and explore the factors and conditions of moral leadership that affect the potential for teacher retention among Alternative Route Certification teachers. Design/methodology/approach: Alternative Route Certification teachers participated in a single focus group. Participants' dialogues were…

  20. Retention of Mastoidectomy Skills After Virtual Reality Simulation Training.

    Science.gov (United States)

    Andersen, Steven Arild Wuyts; Konge, Lars; Cayé-Thomasen, Per; Sørensen, Mads Sølvsten

    2016-07-01

    pretraining relative reaction time, 1.42 [95% CI, 1.37-1.47]; mean end of training relative reaction time, 1.24 [95% CI, 1.16-1.32]; and mean retention relative reaction time, 1.36 [95% CI, 1.30-1.42]; massed practice group: mean pretraining relative reaction time, 1.34 [95% CI, 1.28-1.40]; mean end of training relative reaction time, 1.31 [95% CI, 1.21-1.42]; and mean retention relative reaction time, 1.39 [95% CI, 1.31-1.46]) indicated that cognitive load during the virtual procedures had returned to the pretraining level. Mastoidectomy skills acquired under time-distributed practice conditions were retained better than skills acquired under massed practice conditions. Complex psychomotor skills should be regularly reinforced to consolidate both motor and cognitive aspects. Virtual reality simulation training provides the opportunity for such repeated training and should be integrated into training curricula.

  1. Simulation of arsenic retention in constructed wetlands.

    Science.gov (United States)

    Valles-Aragón, M C; Alarcón-Herrera, M T; Llorens, E; Obradors-Prats, J; Leyva, A

    2017-01-01

    The software RCB-arsenic was developed previously to simulate the metalloid behavior in a constructed wetland (CW). The model simulates water flow and reactive transport by contemplating the major processes of arsenic (As) retention inside of CW. The objective of this study was to validate the RCB-arsenic model by simulating the behavior of horizontal flow CW for As removal from water. The model validation was made using data from a 122-day experiment. Two CWs prototypes were used: one planted with Eleocharis macrostachya (CW_planted) and another one unplanted (CW_unplanted) as a control. The prototypes were fed with synthetic water prepared using well water and sodium arsenite (NaAsO2). In the RCB-arsenic model, a CW prototype was represented using a 2D mesh sized in accordance with the experiment. For simulation of As retention in CW, data addition was established in two stages that considered the mechanisms in the system: (1) aqueous complexation, precipitation/dissolution, and adsorption on granular media and (2) retention by plants: uptake (absorption) and rhizofiltration (adsorption). Simulation of As outlet (μg/L) in stage_1 was compared with CW_unplanted; the experimental mean was 40.79 ± 7.76 and the simulated 39.96 ± 6.32. As concentration (μg/L) in stage_2 was compared with CW_planted, the experimental mean was 9.34 ± 4.80 and the simulated 5.14 ± 0.72. The mass-balance simulation and experiment at 122 days of operation had a similar As retention rate (94 and 91%). The calibrated model RCB-arsenic adequately simulated the As retention in a CW; therefore, it constitutes a powerful tool of design.

  2. Determination of theoretical retention times for peptides analyzed by reversed- -phase high-performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Jerzy Dziuba

    2011-06-01

    -line application and experimental retention times. The above function can effectively predict retention times in situations when experimental conditions differ from the computational environment (various columns, mobile phase composition, use or resignation from chemical modifications during sample preparation, various HPLC equipments. On-line available tR predicting application with correction based on user’s own data may be a useful tool in food peptidomics.  

  3. Retention behaviors of tritium loaded near the surface region of metals by gas absorption and plasma implantation

    Energy Technology Data Exchange (ETDEWEB)

    Otsuka, T., E-mail: t-otsuka@nucl.kyushu-u.ac.jp; Ogawa, Y.; Higaki, M.; Ishitani, Y.

    2015-08-15

    Retention behaviors of hydrogen loaded by gas absorption and plasma implantation to pure copper, pure tungsten and the F82H steels at various temperatures have been examined by the tritium imaging plate technique. Three components are distinguished in hydrogen retained near the surface region; one is an endothermic trapping component in the bulk or near the surface region, second is an exothermic trapping component induced by plasma implantation and third is a trapping component in oxide layers. The relative amount of each component in depth near the surface region of the metals can alter retention behaviors of hydrogen with respect to the loading temperatures.

  4. Physical conditions

    DEFF Research Database (Denmark)

    Nielsen, Birte Lindstrøm; Appleby, M.C.; Waran, N.K.

    2011-01-01

    The physical environment of an animal is sometimes altered if it is found to cause problems for animal welfare. These changes are commonly quite specific (making changes to space, food, water, aspects of housing design such as flooring, or to other environmental factors such as air quality) and may...... be effective in preventing injuries or disease. However, such measures may not be implemented in practice (usually for economic reasons), and where implemented may cause other problems, as when concern for hygiene leads to animals being kept in barren conditions. Numerous ways have also been tried to diversify...... feeding methods in order to improve animal welfare, but specific changes to the environment such as these often have widespread effects, some of which may be detrimental. For example, inclusion of novel pen structures meant to enrich the environment may lead to increased aggression. A more general...

  5. Proteasome inhibition compromises direct retention of cytochrome P450 2C2 in the endoplasmic reticulum.

    Science.gov (United States)

    Szczesna-Skorupa, Elzbieta; Kemper, Byron

    2008-10-15

    To determine whether protein degradation plays a role in the endoplasmic reticulum (ER) retention of cytochromes P450, the effects of proteasomal inhibitors on the expression and distribution of green fluorescent protein chimeras of CYP2C2 and related proteins was examined. In transfected cells, expression levels of chimeras of full-length CYP2C2 and its cytosolic domain, but not its N-terminal transmembrane sequence, were increased by proteasomal inhibition. Redistribution of all three chimeras from the reticular ER into a perinuclear compartment and, in a subset of cells, also to the cell surface was observed after proteasomal inhibition. Redistribution was blocked by the microtubular inhibitor, nocodazole, suggesting that redistribution to the cell surface followed the conventional vesicular transport pathway. Similar redistributions were detected for BAP31, a CYP2C2 binding chaperone; CYP2E1 and CYP3A4, which are also degraded by the proteasomal pathway; and for cytochrome P450 reductase, which does not undergo proteasomal degradation; but not for the ER membrane proteins, sec61 and calnexin. Redistribution does not result from saturation of an ER retention "receptor" since in some cases protein levels were unaffected. Proteasomal inhibition may, therefore, alter ER retention by affecting a protein critical for ER retention, either directly, or indirectly by affecting the composition of the ER membranes.

  6. Effect of lowering dietary calcium intake on fractional whole body calcium retention

    Energy Technology Data Exchange (ETDEWEB)

    Dawson-Hughes, B.; Stern, D.T.; Shipp, C.C.; Rasmussen, H.M.

    1988-07-01

    Although fractional calcium absorption is known to vary inversely with calcium intake, the extent and timing of individual hormonal and calcium absorption responses to altered calcium intake have not been defined. We measured fractional whole body retention of orally ingested /sup 47/Ca, an index of calcium absorption, in nine normal women after they had eaten a 2000-mg calcium diet for 8 weeks and a 300-mg calcium diet for 1, 2, 4, and 8 weeks. After the diet change, serum intact PTH (32.2% increase; P = 0.005), serum 1,25-dihydroxyvitamin D (1,25-(OH)2D; 43.8% increase; P = 0.003), and fractional whole body calcium retention (42.8% increase; P = 0.004) increased within 1 week. Although the PTH and calcium retention responses remained fairly constant throughout the low calcium intake period, serum 1,25-(OH)2D concentrations declined toward baseline after week 1. Thus, the late increase in calcium retention may have resulted from calcium absorption that was independent of 1,25-(OH)2D stimulation.

  7. Intracellular sAPP retention in response to Abeta is mapped to cytoskeleton-associated structures.

    Science.gov (United States)

    Henriques, Ana Gabriela; Vieira, Sandra Isabel; Crespo-López, Maria Elena; Guiomar de Oliveira, Márcio A; da Cruz e Silva, Edgar F; da Cruz e Silva, Odete A B

    2009-05-01

    Amyloid beta (Abeta) contributes to neurodegeneration in Alzheimer's disease and provides a close association between molecular events and pathology, although the underlying molecular mechanisms are unclear. In the work described here, Abeta did not induce amyloid precursor protein (APP) expression, but APP processing/trafficking was markedly affected. In COS-7 cells, Abeta provokes retention of intracellular sAPPalpha (isAPPalpha). Intracellular holo-APP levels remain unchanged, and extracellular total sAPP increases, although extracellular sAPPalpha alone was not altered significantly. In primary neuronal cultures and PC12 cells, isAPP also increased, but this was mirrored by a decrease in extracellular total sAPP. The isAPP retention was particularly associated with the cytoskeletal fraction. The retention "per se" occurred in vesicular-like densities, negative for a C-terminal antibody and strongly positive for the 6E10 antibody, clearly showing abnormal intracellular accumulation of sAPPalpha in response to Abeta. Our data support a dynamic model for intracellular retention of sAPPalpha as an early response to Abeta exposure. Particularly noteworthy was the observation that removal of Abeta reversed the isAPP accumulation. Mechanistically, these findings disclose an attractive physiological response, revealing the capacity of cells to deal with adverse effects induced by Abeta.

  8. Cr(VI) retention and transport through Fe(III)-coated natural zeolite.

    Science.gov (United States)

    Du, Gaoxiang; Li, Zhaohui; Liao, Libing; Hanson, Renee; Leick, Samantha; Hoeppner, Nicole; Jiang, Wei-Teh

    2012-06-30

    Cr(VI) is a group A chemical based on the weight of evidence of carcinogenicity. Its transport and retention in soils and groundwater have been studied extensively. Zeolite is a major component in deposits originated from volcanic ash and tuff after alteration. In this study, zeolite aggregates with the particle size of 1.4-2.4mm were preloaded with Fe(III). The influence of present Fe(III) on Cr(VI) retention by and transport through zeolite was studied under batch and column experiments. The added Fe(III) resulted in an enhanced Cr(VI) retention by the zeolite with a capacity of 82mg/kg. The Cr(VI) adsorption on Fe(III)-zeolite followed a pseudo-second order kinetically and the Freundlich adsorption isotherm thermodynamically. Fitting the column experimental data to HYDRUS-1D resulted in a retardation factor of 3 in comparison to 5 calculated from batch tests at an initial Cr(VI) concentration of 3mg/L. The results from this study showed that enhanced adsorption and retention of Cr(VI) may happen in soils derived from volcanic ash and tuff that contains significant amounts of zeolite with extensive Fe(III) coating. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Source or Sink: Investigating the role of storm water retention ponds in the urban landscape (Invited)

    Science.gov (United States)

    Lev, S.; Casey, R.; Ownby, D.; Snodgrass, J.

    2009-12-01

    hydrologic, ecologic, and geochemical conditions have been identified. Results from these investigations suggest that pollutant conditions, specifically trace metals and chloride, limit the use of these ponds by amphibians and effect the distribution of earthworms within ponds. The soils in ponds associated with high use roadways contain elevated levels of PAHs, Zn and Cu and the groundwater beneath these same ponds tends to have elevated chloride levels year round. Pond and associated flood plain soils in these systems have been altered and exhibit elevated Na+ or Ca2+ concentrations suggesting years of interaction with road salt contaminated discharge. These Na+ and Ca2+ form soils affect the retention of dissolved trace metals with Ca-enriched soils potentially increasing the dissolved metal concentrations of surface and pore waters and enabling the transport of roadway derived metals to surface waters and Na-enriched soils scavenging trace metals from incoming runoff. The increase in dissolved metals may also increase the toxicity to amphibians and other organisms inhabiting the storm water ponds and ultimately, streams fed by ground water recharge from ponds. Our results to date suggest both the intended and unintended function of storm water ponds in urban landscapes are complicated and deserving of more attention.

  10. Correlation between retention force of experimental plates and viscosity of experimental fluids

    Directory of Open Access Journals (Sweden)

    Mladenović Dragan

    2011-01-01

    Full Text Available Introduction. Saliva viscosity plays a significant role in the biophysical segment of the total retention potential of total dentures. Objective. The aim of the paper was to establish the dependence of dynamic retention force of experimental plates on experimental fluid viscosity and especially time dependence of these parameters, following at the same time relative changes of the distance between the experimental plate and dentures support established by the dislocation of the experimental plate in both directions. Methods. For experimental verification we used an original device with the aim to enable in vivo simulation on the phantom made of the upper total denture prosthesis support and experimental plate. The experiment consisted of two parts. In the first part we determined the value of the dynamic retention force with plates without and with achieved ventilation effect. In the second part we determined time dependence of the dynamic retention force of experimental plates on the viscosity of experimental fluids that had been priorly determined on identical samples (8 ml of experimental fluid samples using a rotational viscometer (Haake RV-12 with a sensor (MV, Germany. Results Under the conditions of variable viscosity rates of seven experimental fluids (from 0.02 to 1309.04 mPa•s, we registered the time dependence of dynamic retention force of the experimental plate related to fluid viscosity during the action of the continual dislocating force of the separating directions. In addition, the maximal height of the dislocation of the experimental plate was registered. The dynamic retention force, manifested by the separating direction of the experimental plate dislocation, was increased concurrently with increased viscosity. Conclusion. The increase of dynamic retention force depends directly on medium viscosity. Close border values of fluid viscosity above the investigated ones, the impossibility of experimental layer thinning and the

  11. Phosphorus Retention in Stormwater Control Structures across Streamflow in Urban and Suburban Watersheds

    Directory of Open Access Journals (Sweden)

    Shuiwang Duan

    2016-09-01

    Full Text Available Recent studies have shown that stormwater control measures (SCMs are less effective at retaining phosphorus (P than nitrogen. We compared P retention between two urban/suburban SCMs and their adjacent free-flowing stream reaches at the Baltimore Long-Term Ecological Study (LTER site, and examined changes in P retention in SCMs across flow conditions. Results show that, when compared with free-flowing stream reaches, the SCMs had significantly lower dissolved oxygen (%DO and higher P concentrations, as well as lower mean areal retention rates and retention efficiencies of particulate P (PP. In all the SCMs, concentrations of total dissolved phosphorus (TDP consistently exhibited inverse correlations with %DO that was lower during summer base flows. Particulate phosphorus (PP concentrations peaked during spring high flow period in both streams and in-line pond/SCMs, but they were also higher during summer base flows in suburban/urban SCMs. Meanwhile, PP areal retention rates and retention efficiencies of the SCMs changed from positive (indicating retention during high flows to negative (indicating release during low flows, while such changes across flow were not observed in free-flowing stream reaches. We attribute the changing roles of SCMs from a PP sink to a PP source to changes in SCM hydrologic mass balances, physical sedimentation and biogeochemical mobilization across flows. This study demonstrates that in suburban/urban SCMs, P retained during high flow events can be released during low flows. Cultivation of macrophytes and/or frequent sediment dredging may provide potential solutions to retaining both P and nitrogen in urban SCMs.

  12. Exploring The Benefits Of Staff Retention Strategies And ...

    African Journals Online (AJOL)

    Exploring The Benefits Of Staff Retention Strategies And Performance In The ... between staff retention strategies (rewards) and organizational performance. Further ... and provision of appropriate incentives that favoured welfare of employees' ...

  13. The drivers of student enrolment and retention: A stakeholder ...

    African Journals Online (AJOL)

    ... and retention: A stakeholder perception analysis in higher education. ... and tuition, institutional performance, inconsistency in teaching quality and the relative ... retention, higher education, Q methodology, student development strategy, ...

  14. Satisfaction with retention factors as predictors of the job ...

    African Journals Online (AJOL)

    2013-05-03

    May 3, 2013 ... scarce skills in a South African client services company. Retention ... satisfaction with retention factors and their job embeddedness have been shown to influence their ..... 'Quality of working life and turnover intention in ...

  15. Memory Vocabulary Learning Strategies and Long-Term Retention ...

    African Journals Online (AJOL)

    Memory Vocabulary Learning Strategies and Long-Term Retention. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING ... The results were reflected in the students' short-term and long-term memory retention.

  16. DRAINAGE AND RETENTION ENHANCEMENT OF A WHEAT STRAW PULP CONTAINING FURNISH USING MICROPARTICLE RETENTION AIDS

    Directory of Open Access Journals (Sweden)

    Tom Hultholm

    2011-02-01

    Full Text Available The usage of non-wood pulps in furnishes for the production of various paper grades is a real alternative for the substitution of wood pulp in papermaking. In terms of the papermaking process, the main limiting factor for non-wood pulp utilization is poor dewatering. This problem can be partially solved by means of retention aids, and the modern microparticle-based retention aids are very promising for this application. In this study the main aim was to characterize how the microparticle retention systems affect the retention, dewatering, and formation of a non-wood pulp furnish and how these effects and mechanisms differ when compared to normal wood pulp. The performance of several commercially available retention aids was studied by making dynamic sheet forming tests for reference and an organosolv wheat straw furnish. The emphasis in the experiments was on drainage enhancement. The maximum drainage gain obtained with the bentonite-CPAM retention aid system was about 5%. Despite the improved drainage, dewatering of the reference furnish was better than for the non-wood containing furnish.

  17. Serotonin transporter polyadenylation polymorphism modulates the retention of fear extinction memory.

    Science.gov (United States)

    Hartley, Catherine A; McKenna, Morgan C; Salman, Rabia; Holmes, Andrew; Casey, B J; Phelps, Elizabeth A; Glatt, Charles E

    2012-04-01

    Growing evidence suggests serotonin's role in anxiety and depression is mediated by its effects on learned fear associations. Pharmacological and genetic manipulations of serotonin signaling in mice alter the retention of fear extinction learning, which is inversely associated with anxious temperament in mice and humans. Here, we test whether genetic variation in serotonin signaling in the form of a common human serotonin transporter polyadenylation polymorphism (STPP/rs3813034) is associated with spontaneous fear recovery after extinction. We show that the risk allele of this polymorphism is associated with impaired retention of fear extinction memory and heightened anxiety and depressive symptoms. These STPP associations in humans mirror the phenotypic effects of serotonin transporter knockout in mice, highlighting the STPP as a potential genetic locus underlying interindividual differences in serotonin transporter function in humans. Furthermore, we show that the serotonin transporter polyadenylation profile associated with the STPP risk allele is altered through the chronic administration of fluoxetine, a treatment that also facilitates retention of extinction learning. The propensity to form persistent fear associations due to poor extinction recall may be an intermediate phenotype mediating the effects of genetic variation in serotonergic function on anxiety and depression. The consistency and specificity of these data across species provide robust support for this hypothesis and suggest that the little-studied STPP may be an important risk factor for mood and anxiety disorders in humans.

  18. Influence of hydrologic loading rate on phosphorus retention and ecosystem productivity in created wetlands. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Mitsch, W.J.; Cronk, J.K.

    1995-01-01

    Four 2- to 3-ha constructed freshwater riparian wetlands in Lake County, Illinois, were subjected to two hydrologic regimes of pumped river water to simulate nonpoint source pollution. The experimental wetlands at the Des Plaines River Wetland Demonstration Project were designed to develop and test wetland design principles, construction methods, and management programs needed to create and maintain wetlands for the purposes of water quality management, flood control, and fish and wildlife habitat. High-flow wetlands (HFW) with short retention times received 34 to 38 cm of river water per week, and low-flow wetlands (LFW) with high retention times received 10 to 15 cm per week. This report summarizes research results for phosphorus dynamics and retention, macrophyte development, periphyton productivity, and overall water column metabolism through 1992. All of these functions were hypothesized to be related to hydrologic conditions.

  19. Retention performance of green roofs in representative climates worldwide

    Science.gov (United States)

    Viola, F.; Hellies, M.; Deidda, R.

    2017-10-01

    role of climatic conditions, namely annual rainfall, potential evapotranspiration and their seasonality cycles, we found that they drive green roofs retention performance, which are the maxima when rainfall and temperature are in phase. Finally, we provide design charts for a first approximation of possible hydrological benefits deriving from the implementation of intensive or extensive green roofs in different world areas. As an example, 25 big cities have been indicated as benchmark case studies.

  20. Inguinal Herniation of the Urinary Bladder Presenting as Recurrent Urinary Retention

    Directory of Open Access Journals (Sweden)

    Amit Frenkel

    2015-01-01

    Full Text Available Herniation of the urinary bladder into the inguinal canal is an uncommon finding, observed in 0.5–4% of inguinal hernias (Curry (2000. It is usually associated with other conditions that increase intra-abdominal pressure such as bladder neck obstruction due to prostatic hypertrophy. Consequently, in men, it is usually associated with some degree of urinary retention. We present a 42-year-old man in whom herniation of the urinary bladder was the cause of urinary retention, and not vice versa. The patient was on tumor necrosis factor alpha antagonist (TNFA (Etanercept for severe Ankylosing spondylitis. Initially, the urinary retention was thought to be a side effect of the medication, but after the drug was discontinued, urinary retention persisted. CT and MRI demonstrated huge herniation of the urinary bladder into the inguinal canal. Immediately after the hernia was repaired, bladder function was restored. TNF treatment was restarted, and no further urinary symptoms were observed in the next two years of follow-up. In this case, the primary illness and its treatment were distracting barriers to early diagnosis and treatment. In younger patients with a large hernia who develop unexpected urinary retention, herniation of the urinary bladder should be highly considered in the differential diagnosis.

  1. Retention of arsenic and selenium compounds using limestone in a coal gasification flue gas.

    Science.gov (United States)

    Diaz-Somoano, Mercedes; Martinez-Tarazona, M Rosa

    2004-02-01

    Volatile arsenic and selenium compounds present in coals may cause environmental problems during coal combustion and gasification. A possible way to avoid such problems may be the use of solid sorbents capable of retaining these elements from flue gases in gas cleaning systems. Lime and limestone are materials that are extensively employed for the capture of sulfur during coal processing. Moreover, they have also proven to have good retention characteristics for arsenic and selenium during combustion. The aim of this work was to ascertain whether this sorbent is also useful for retaining arsenic and selenium species in gases produced in coal gasification. The study was carried out in a laboratory-scale reactor in which the sorbent was employed as a fixed bed, using synthetic gas mixtures. In these conditions, retention capacities for arsenic may reach 17 mg g(-1) in a gasification atmosphere free of H2S, whereas the presence of H2S implies a significant decrease in arsenic retention. In the case of selenium, H2S does not influence retention which may reach 65 mg g(-1). Post-retention sorbent characterization, thermal stability, and water solubility tests have shown that chemical reaction is one of the mechanisms responsible for the capture of arsenic and selenium, with Ca(AsO2)2 and CaSe being the main compounds formed.

  2. Retention modeling in combined pH/organic solvent gradient reversed-phase HPLC.

    Science.gov (United States)

    Zisi, Ch; Fasoula, S; Nikitas, P; Pappa-Louisi, A

    2013-07-07

    An approach for retention modeling of double pH/organic solvent gradient data easily generated by automatically mixing two mobile phases with different pH and organic content according to a linear pump program is proposed. This approach is based on retention models arising from the evaluation of the retention data of a set of 17 OPA derivatives of amino acids obtained in 27 combined pH/organic solvent gradient runs performed between fixed initial pH/organic modifier values but different final ones and for different gradient duration. The derived general model is a ninth parameter equation easily manageable through a linear least-squares fitting but it requires eighteen initial pH/organic modifier gradient experiments for a satisfactory retention prediction in various double gradients of the same kind with those used in the fitting procedure. Two simplified versions of the general model, which were parameterized based on six only initial pH/organic modifier gradients, were also proposed, when one of the final double gradient conditions, pH or organic content was kept constant. The full and the simplified models allowed us to predict the experimental retention data in simultaneous pH/organic solvent double gradient mode very satisfactorily without the solution of the fundamental equation of gradient elution.

  3. 5 CFR 536.202 - Optional grade retention.

    Science.gov (United States)

    2010-01-01

    ... §§ 536.102 and 536.203, an authorized agency official may provide grade retention to an employee moving... lower-graded position. (c) When an employee is offered a position with grade retention under this... entitlement to grade retention under § 536.201 if the agency actually moves the employee to the lower-graded...

  4. 5 CFR 536.302 - Optional pay retention.

    Science.gov (United States)

    2010-01-01

    ....102 and this section, an authorized agency official may provide pay retention to an employee not... employee to pay retention under paragraph (a) of this section, the agency must apply the geographic... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Optional pay retention. 536.302 Section...

  5. 5 CFR 536.208 - Termination of grade retention.

    Science.gov (United States)

    2010-01-01

    ... grade retention benefits (except that, if an employee's election specifically provides that the... grade retention terminates under this section, the employee's rate of basic pay must be set in... CFR part 531, subpart B, for GS positions). An employee is not entitled to pay retention under subpart...

  6. 5 CFR 351.401 - Determining retention standing.

    Science.gov (United States)

    2010-01-01

    ... REDUCTION IN FORCE Scope of Competition § 351.401 Determining retention standing. Each agency shall determine the retention standing of each competing employee on the basis of the factors in this subpart and... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Determining retention standing. 351.401...

  7. 4 CFR 5.2 - Grade and pay retention.

    Science.gov (United States)

    2010-01-01

    ... terminate. (e) Pay retention. (1) Any GAO employee: who ceases to be entitled to a retained grade by reason... 4 Accounts 1 2010-01-01 2010-01-01 false Grade and pay retention. 5.2 Section 5.2 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM COMPENSATION § 5.2 Grade and pay retention. (a) Change of...

  8. 5 CFR 536.301 - Mandatory pay retention.

    Science.gov (United States)

    2010-01-01

    ... § 536.102 and this section, an agency must provide pay retention to an employee who moves between... action that may entitle the employee to pay retention under paragraph (a) of this section, the agency.... Optional pay retention under § 536.302 may apply when an employee transfers to a different agency as a...

  9. 5 CFR 536.204 - Period of grade retention.

    Science.gov (United States)

    2010-01-01

    ... that provides entitlement to grade retention for 2 years beginning on the date the employee is placed... reduces an employee in grade under circumstances also entitling the employee to grade retention, the...-year grade retention period if the employee's grade was retained under this part in the appointment...

  10. 5 CFR 351.506 - Effective date of retention standing.

    Science.gov (United States)

    2010-01-01

    ... the performance factor as provided in § 351.504: (a) The retention standing of each employee released... is so released. (b) The retention standing of each employee retained in a competitive level as an... been released had the exception not been used. The retention standing of each employee retained under...

  11. Summary and frequency of KR presentation effects on retention of a motor skill.

    Science.gov (United States)

    Sidaway, B; Moore, B; Schoenfelder-Zohdi, B

    1991-03-01

    This experiment investigates the recent proposal of Schmidt, Young, Swinnen, and Shapiro (1989) that summary knowledge of results (KR) improves skill retention. In Schmidt et al.'s experiment, however, summary length varied concomitantly with the frequency of KR presentation. The current investigation held KR presentation frequency constant while manipulating the number of trials seen in the summary KR display. Subjects were required to perform a timing task on a linear slide. Five groups (n = 12) of subjects participated in acquisition trials then in 10-min and 2-day delayed no-KR retention tests. In 4 conditions, subjects completed each acquisition block without any KR, but following each block they received KR on either 15, 7, 3, or 1 of the 15 trials performed in that block. In the final condition subjects received immediate KR. Analysis of the absolute constant error (magnitude of CE) data for acquisition revealed all groups improved with practice and the immediate KR group performed better than all the summary groups which in turn did not differ significantly. Analysis of the magnitude of CE retention data found performance to be worse on the 2-day retention test for all groups. The effect of condition was significant. The 1/1 group had lower error scores than all other groups, which in turn were not significantly different. Analyses of variable error (VE) revealed only that VE decreased with practice. These findings suggest frequency of KR presentation may be the basis for the summary KR effect found by Schmidt et al. (1989).

  12. Aespoe Hard Rock Laboratory. Final report of the first stage of the tracer retention understanding experiments

    Energy Technology Data Exchange (ETDEWEB)

    Winberg, A. [Conterra AB, Uppsala (Sweden); Andersson, Peter [Geosigma AB, Uppsala (Sweden); Hermanson, Jan [Golder Grundteknik, Solna (Sweden); Byegaard, Johan [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry; Cvetkovic, V. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Water Resources Engineering; Birgersson, Lars [Kemakta Konsult AB, Stockholm (Sweden)

    2000-03-15

    in the laboratory. A test using {sup 137}Cs showed that after termination of the test, some 63% of the injected activity remained sorbed in the rock. The interpretation of the in situ tests with sorbing tracers was performed using the LaSAR approach, developed as a part of the TRUE project. In this approach the studied flow path is viewed as a part of an open fracture. Key processes are spatially variable advection and mass transfer. The evaluation shows that laboratory diffusion data are not representative for in situ conditions, and that a close fit between field and modelled breakthrough is obtained only when a parameter group which includes diffusion is enhanced with a factor varying between 32-50 for all tracers and experiments (except for Cs) and 137 for Cs. Our interpretation is that the enhancement is mainly due to higher diffusivity/porosity and higher sorption in the part of the altered rim zone of the feature which is accessible over the time scales of the in situ experiments, compared to data obtained from core samples in the laboratory. Estimates of in situ values of the important transport parameters are provided under an assumption of a valid range of porosity in the accessible part of the rim zone in the order of 2-2.4%. Unlimited diffusion/sorption in the matrix rock was interpreted as the dominant retention mechanism on the time scales of the TRUE-1 in situ experiments. This is particularly true for the more strongly sorbing tracers, e.g. Cs. The effects on tracer retention by equilibrium surface sorption and limited sorption in gouge material were found to be observable, but of secondary importance. Similarly, the effect of sorption into stagnant water zones was found to be limited.

  13. Membrane bioreactor sludge rheology at different solid retention times.

    Science.gov (United States)

    Laera, G; Giordano, C; Pollice, A; Saturno, D; Mininni, G

    2007-10-01

    Rheological characterization is of crucial importance in sludge management both in terms of biomass dewatering and stabilization properties and in terms of design parameters for sludge handling operations. The sludge retention time (SRT) has a significant influence on biomass properties in biological wastewater treatment systems and in particular in membrane bioreactors (MBRs). The aim of this work is to compare the rheological behaviour of the biomass in a MBR operated under different SRTs. A bench-scale MBR was operated for 4 years under the same conditions except for the SRT, which ranged from 20 days to complete sludge retention. The rheological properties were measured over time and the apparent viscosity was correlated with the concentration of solid material when equilibrium conditions were reached and maintained. The three models most commonly adopted for rheological simulations were evaluated and compared in terms of their parameters. Then, steady-state average values of these parameters were related to the equilibrium biomass concentration (MLSS). The models were tested to select the one better fitting the experimental data in terms of mean root square error (MRSE). The relationship between the apparent viscosity and the shear rate, as a function of solid concentration, was determined and is proposed here. Statistical analysis showed that, in general, the Bingham model provided slightly better results than the Ostwald one. However, considering that a strong correlation between the two parameters of the Ostwald model was found for all the SRTs tested, both in the transient growth phases and under steady-state conditions, this model might be used more conveniently. This feature suggests that the latter model is easier to be used for the determination of the sludge apparent viscosity.

  14. 糖尿病状态下P-糖蛋白表达和功能的改变及其临床意义%Alterations in Expression and Function of P-glycoprotein Under Diabetic Condition and Their Mechanism

    Institute of Scientific and Technical Information of China (English)

    张璐璐; 刘晓东

    2011-01-01

    糖尿病是由多种原因引起的胰岛素分泌不足以及靶细胞对胰岛素敏感性降低,继而引起糖、蛋白质、脂肪及水电解质代谢异常的一种临床综合征.P-糖蛋白作为药物的外排泵,参与了糖尿病及其并发症的发生发展的全过程.糖尿病所引起的体内环境的变化,会导致各组织中P-糖蛋白功能和表达发生改变,而这种改变义会进一步影响药物治疗的药理毒理效应.因此研究糖尿病状态下各组织中P-糖蛋白功能和表达的改变模式及其机制对于糖尿病及其并发症的治疗具有极其重要的临床意义.%Diabetes is a clinical syndrome which is caused by a variety of reasons for the absolute or relative lack of insulin secretion and reduced insulin sensitivity of target cells,and then causing sugar rising,protein,fat and water electrolyte metabolic disorders. P-glycoprotein, as a drug efflux pump, involves in the whole process of the development of diabetes and its complications. The changes in the environment of body caused by diabetes will lead to the alterations of function and expression of P-glycoprotein in various tissues, which will further affect the pharmacological and toxicological effects of drug. Therefore,it is extremely important for the clinical treatment of diabetes and its complications to study the phenomenon and mechanism of P-glycoprotein alteration in different tissues.

  15. Improving student retention in computer engineering technology

    Science.gov (United States)

    Pierozinski, Russell Ivan

    The purpose of this research project was to improve student retention in the Computer Engineering Technology program at the Northern Alberta Institute of Technology by reducing the number of dropouts and increasing the graduation rate. This action research project utilized a mixed methods approach of a survey and face-to-face interviews. The participants were male and female, with a large majority ranging from 18 to 21 years of age. The research found that participants recognized their skills and capability, but their capacity to remain in the program was dependent on understanding and meeting the demanding pace and rigour of the program. The participants recognized that curriculum delivery along with instructor-student interaction had an impact on student retention. To be successful in the program, students required support in four domains: academic, learning management, career, and social.

  16. Teacher professionalisation in relation to retention strategies

    DEFF Research Database (Denmark)

    Wahlgren, Bjarne

    2014-01-01

    pedagogical strategies have any impact on retention? The project started in 2010 and includes annual interventions and measurements of the output of these inventions. The intervention includes various teacher training programs e.g. about training in cooperative learning, classroom management, conflict......Teacher professionalization in relation to retention strategies Bjarne Wahlgren, professor, director National Centre of Competence Development, University of Aarhus, Denmark The research project ‘New roles for the teacher’ was initiated due to a concern about the increasing number of dropouts...... within Danish VET. The main research questions are: Is it possible to train teachers to be able to focus on the students’ completion of the program and not only on the subject matter? Do teachers change their attitudes and actual performance in the classroom after training programs? And do new...

  17. Retention technique #1. Developing managerial warmth.

    Science.gov (United States)

    Davidhizar, R

    1989-01-01

    A manager who has interpersonal warmth is not simply gullible or naive, but instead possesses a valuable skill in reaching others. In most manager-employee relationships, some degree of limit-setting and judgment are necessary; however, warmth integrated with limit-setting is more satisfying for both employee and manager. Although warmth as an interpersonal phenomenon is affected by the employee's perception, certain managerial actions can increase the likelihood of being perceived as warm; yet, in spite of careful adherence to the guidelines for communicating warmth, managerial warmth will still be rejected in some situations. As is true of any managerial technique, the effective use of warmth requires an assessment of the employee's personality and the approach most appropriate for the situation at hand. The excellent manager is able to quickly adapt, matching the level of warmth to the situation. See Nurse Manager Retention Factors for viewpoints from nurses themselves. Interpersonal management style is an important retention factor.

  18. Mouse Model for Protein Tyrosine Phosphatase D (PTPRD) Associations with Restless Leg Syndrome or Willis-Ekbom Disease and Addiction: Reduced Expression Alters Locomotion, Sleep Behaviors and Cocaine-Conditioned Place Preference

    Science.gov (United States)

    Drgonova, Jana; Walther, Donna; Wang, Katherine J; Hartstein, G Luke; Lochte, Bryson; Troncoso, Juan; Uetani, Noriko; Iwakura, Yoichiro; Uhl, George R

    2015-01-01

    The receptor type protein tyrosine phosphatase D (PTPRD) gene encodes a cell adhesion molecule likely to influence development and connections of addiction-, locomotion- and sleep-related brain circuits in which it is expressed. The PTPRD gene harbors genome-wide association signals in studies of restless leg syndrome (Willis-Ekbom disease [WED]/restless leg syndrome [RLS]; p p > 10−8 associations in several reports). We now report work that seeks (a) association between PTPRD genotypes and expression of its mRNA in postmortem human brains and (b) RLS-related, addiction-related and comparison behavioral phenotypes in hetero- and homozygous PTPRD knockout mice. We identify associations between PTPRD SNPs and levels of PTPRD mRNA in human brain samples that support validity of mouse models with altered PTPRD expression. Knockouts display less behaviorally defined sleep at the end of their active periods. Heterozygotes move more despite motor weakness/impersistence. Heterozygotes display shifted dose-response relationships for cocaine reward. They display greater preference for places paired with 5 mg/kg cocaine and less preference for places paired with 10 or 20 mg/kg. The combined data provide support for roles for common, level-of-expression PTPRD variation in locomotor, sleep and drug reward phenotypes relevant to RLS and addiction. Taken together, mouse and human results identify PTPRD as a novel therapeutic target for RLS and addiction phenotypes. PMID:26181631

  19. Push Vs Pull: Factors Influence Student Retention

    OpenAIRE

    Matthew Leone; Robert G. Tian

    2009-01-01

    Problem statement: Student retention becomes one of the most significant issues that administrators of colleges and universities must deal with in todays highly competitive market. Approach: In fact retaining a student is fundamental to the ability of an institution to carry out its mission. A high rate of attrition is not only a fiscal problem for schools, but a symbolic failure of an institution to achieve its purpose. Results: There are many ways to keep students retain at the same college...

  20. Maximizing Female Retention In the Navy

    Science.gov (United States)

    2014-03-01

    GUARD guaranteed assignment retention detailing JAG judge advocate general corps JAMRS joint advertising market research and studies LT lieutenant...Secretary of Defense, Personnel and Readiness, 2011). Furthermore, women are half as likely to continue to serve according to the Joint Advertising ... stereotypes will occur, thus leading to better intergroup relations (Tolbert et al., 1995). Critical mass is related to social contact theory in that

  1. 300 Area Building Retention Evaluation Mitigation Plan

    Energy Technology Data Exchange (ETDEWEB)

    D. J. McBride

    2007-07-03

    Evaluate the long-term retention of several facilities associated with the PNNL Capability Replacement Laboratory and other Hanfor mission needs. WCH prepared a mitigation plan for three scenarios with different release dates for specific buildings. The evaluations present a proposed plan for providing utility services to retained facilities in support of a long-term (+20 year) lifespan in addition to temporary services to buildings with specified delayed release dates.

  2. The Combinatorial Retention Auction Mechanism (CRAM)

    OpenAIRE

    Coughlan, Peter; Gates, William (Bill); Myung, Noah

    2013-01-01

    Approved for public release; distribution is unlimited. Revised version We propose a reverse uniform price auction called Combinatorial Retention Auction Mechanism (CRAM) that integrates both monetary and non-monetary incentives (NMIs). CRAM computes the cash bonus and NMIs to a single cost parameter, retains the lowest cost employees and provides them with compensation equal to the cost of the first excluded employee. CRAM is dominant strategy incentive compatible. We provide optimal b...

  3. POSSIBLE RECESSION CURVE APPLICATIONS FOR RETENTION EVALUATION

    Directory of Open Access Journals (Sweden)

    Daniel Liberacki

    2015-11-01

    Full Text Available The objective of the article was to present possible applications of recession flow curve in a small lowland watershed retention discharge size evaluation. The examined woodland micro catchment area of 0.52 sq km is located in Puszcza Zielonka in central Wielkopolska. The Hutka catchment is typically woody with high retention abilities. The catchment of the Hutka watercourse is forested in 89%, the other 11% is covered by swamps and wasteland. The predominant sites are fresh mixed coniferous forest (BMśw, fresh coniferous forest (Bśw and alder carr forest (Ol. Landscape in catchment is characterized by a large number of interior depressions, filled partly with rainwater or peatbogs, with poorly developed natural drainage. The watercourses do not exceed 1 km in length, the mean width is approx. 0.5 m, while mean depth ranges from 0.2 to 0.3 m. During hydrological research conducted in 1997/1998–1999/2000, 35 major (characteristic raised water stages were observed in Hutka after substantial precipitation. The recession curve dating from 18–24 September 2000 has the α and n rates nearest to average. Comparing the model curve and the curve created by observing watercourse flow, one can notice their resemblance and that they have similar ordinate values as well as shape. In the case of other recession curves, the maximum differences of ordinate values are also about 0.1–0.2 l/s/km2. The measuured α and n rates do not reveal any regularities. There are no significant statistical Horton model parameter (for recession flow curves dependencies between α and n and e.g. initial flows (Qo or the whole period of high water waves (Qp. Consequently, calculated relation between these parameters is only an approximation for the general evaluation of the retention discharge in the catchment area towards retention with flow function.

  4. Epigenetic Alterations in Density Selected Human Spermatozoa for Assisted Reproduction.

    Directory of Open Access Journals (Sweden)

    Bolan Yu

    Full Text Available Epidemiological evidence indicates that assisted reproductive technologies (ART may be associated with several epigenetic diseases such as Beckwith-Wiedemann syndrome (BWS or Silver-Russell syndrome (SRS. Selection of sperm by density-gradients in ART has improved DNA integrity and sperm quality; however, epigenetic alterations associated with this approach are largely unknown. In the present study, we investigated DNA methylation and histone retention profiles in raw sperm and selected sperm derived from the same individual and separated by using density-gradients. Results from a study group consisting of 93 males demonstrated that both global DNA methylation and histone retention levels decreased in density selected sperm. Compared to unselected raw sperm, histone transition rates decreased by an average of 27.2% in selected sperm, and the global methylation rate was 3.8% in unselected sperm and 3.3% in the selected sperm. DNA methylation and histone retention location profiling analyses suggested that these alterations displayed specific location patterns in the human genome. Changes in the pattern of hypomethylation largely occurred in transcriptional factor gene families such as HOX, FOX, and GATA. Histone retention increased in 67 genes, whereas it was significantly clustered in neural development-related gene families, particularly the olfactory sensor gene family. Although a causative relationship could not be established, the results of the present study suggest the possibility that sperm with good density also possess unique epigenetic profiles, particularly for genes involved in neural and olfactory development. As increasing evidence demonstrates that epigenetics plays a key role in embryonic development and offspring growth characteristics, the specific epigenetic alterations we observed in selected sperm may influence the transcriptional process and neural development in embryos.

  5. Improved motor sequence retention by motionless listening.

    Science.gov (United States)

    Lahav, Amir; Katz, Tal; Chess, Roxanne; Saltzman, Elliot

    2013-05-01

    This study examined the effect of listening to a newly learned musical piece on subsequent motor retention of the piece. Thirty-six non-musicians were trained to play an unfamiliar melody on a piano keyboard. Next, they were randomly assigned to participate in three follow-up listening sessions over 1 week. Subjects who, during their listening sessions, listened to the same initial piece showed significant improvements in motor memory and retention of the piece despite the absence of physical practice. These improvements included increased pitch accuracy, time accuracy, and dynamic intensity of key pressing. Similar improvements, though to a lesser degree, were observed in subjects who, during their listening sessions, were distracted by another task. Control subjects, who after learning the piece had listened to nonmusical sounds, showed impaired motoric retention of the piece at 1 week from the initial acquisition day. These results imply that motor sequences can be established in motor memory without direct access to motor-related information. In addition, the study revealed that the listening-induced improvements did not generalize to the learning of a new musical piece composed of the same notes as the initial piece learned, limiting the effects to musical motor sequences that are already part of the individual's motor repertoire.

  6. Determinants of feedback retention in soccer players

    Directory of Open Access Journals (Sweden)

    Januário Nuno

    2016-06-01

    Full Text Available This study analyzed soccer players’ retention of coaches’ feedback during training sessions. We intended to determine if the retention of information was influenced by the athletes’ personal characteristic (age, gender and the sports level, the quantity of information included in coach’s feedback (the number of ideas and redundancy, athletes’ perception of the relevance of the feedback information and athletes’ motivation as well as the attention level. The study that was conducted over the course of 18 sessions of soccer practice, involved 12 coaches (8 males, 4 females and 342 athletes (246 males, 96 females, aged between 10 and 18 years old. All coach and athlete interventions were transposed to a written protocol and submitted to content analysis. Descriptive statistics and multiple linear regression were calculated. The results showed that a substantial part of the information was not retained by the athletes; in 65.5% of cases, athletes experienced difficulty in completely reproducing the ideas of the coaches and, on average, the value of feedback retention was 57.0%. Six variables with a statistically significant value were found: gender, the athletes’ sports level, redundancy, the number of transmitted ideas, athletes’ perception of the relevance of the feedback information and the athletes’ motivation level.

  7. Retention of perceptual generalization of fear extinction.

    Science.gov (United States)

    Pappens, Meike; Schroijen, Mathias; Van den Bergh, Omer; Van Diest, Ilse

    2015-12-01

    Fear reduction obtained during a fear extinction procedure can generalize from the extinction stimulus to other perceptually similar stimuli. Perceptual generalization of fear extinction typically follows a perceptual gradient, with increasing levels of fear reduction the more a stimulus resembles the extinction stimulus. The current study aimed to investigate whether perceptual generalization of fear extinction can be observed also after a retention interval of 24h. Fear was acquired to three geometrical figures of different sizes (CS(+), CS1(+) and CS2(+)) by consistently pairing them with a short-lasting suffocation experience (US). Three other geometrical figures that were never followed by the US served as control stimuli (CS(-), CS1(-), CS2(-)). Next, only the CS(+) was extinguished by presenting it in the absence of the US. One day later, fear responses to all stimuli were assessed without any US-presentation. Outcome measures included startle blink EMG, skin conductance, US expectancy, respiratory rate and tidal volume. On day 2 spontaneous recovery of fear was observed in US expectancy and tidal volume, but not in the other outcomes. Evidence for the retention of fear extinction generalization was present in US expectancy and skin conductance, but a perceptual gradient in the retention of generalized fear extinction could not be observed.

  8. Leadership training to improve nurse retention.

    Science.gov (United States)

    Wallis, Allan; Kennedy, Kathy I

    2013-05-01

    This paper discusses findings from an evaluation of a training programme designed to promote collaborative, team-based approaches to improve nurse retention within health care organizations. A year-long leadership training programme was designed and implemented to develop effective teams that could address retention challenges in a diverse set of organizations in Colorado ranging from public, private to non-profit. An evaluation, based on a combination of participant observation, group interviews, and the use of standardized tests measuring individual emotional intelligence and team dynamics was conducted to assess the effectiveness of the training programme. What role do the emotional intelligence of individual members and organizational culture play in team effectiveness? Out of five teams participating in the training programme, two performed exceptionally well, one experienced moderate success and two encountered significant problems. Team dynamics were significantly affected by the emotional intelligence of key members holding supervisory positions and by the existing culture and structure of the participating organizations. Team approaches to retention hold promise but require careful development and are most likely to work where organizations have a collaborative problem-solving environment. © 2012 Blackwell Publishing Ltd.

  9. Measuring Predictors of Student Retention Rates

    Directory of Open Access Journals (Sweden)

    Allen L. Webster

    2011-01-01

    Full Text Available Problem statement: Colleges and universities place more emphasis on student retention rates than ever before. Educational institutions are intensifying efforts to discourage student departure and preserve their established student base. Economic pressures that bear heavily on academic administration make such efforts highly critical for institutional success. Research on this vital issue is especially important due to the vigorous competition among college and universities to recruit students and maintain enrollment levels. This pressure is heightened by the fact that it costs more to attract students than it does to retain them. Approach: This study uses institutional-based data to examine student attrition levels with the intent to identify their chief determinants and provide the foundation for post-secondary institutions to explore the viability of their own retention programs. Discriminant analysis is used to distinguish those schools that exhibit a higher degree of success in retaining student enrollments from those who suffer higher departure trends. Results: Tuition, student/teacher ratio and the amount of dollar aid offered the students all play substantial roles in encouraging persistence. The acceptance rate and enrollment levels were found to provide less discriminatory power. Conclusion: Students are influenced by the personal attention they receive and the manner in which their chosen institution of higher education caters to their individual needs, problems and concerns. Colleges and universities concerned with student retention would benefit from concentrated programs designed to provide individualized student services that address immediate student needs.

  10. High efficiency diffusion molecular retention tumor targeting.

    Directory of Open Access Journals (Sweden)

    Yanyan Guo

    Full Text Available Here we introduce diffusion molecular retention (DMR tumor targeting, a technique that employs PEG-fluorochrome shielded probes that, after a peritumoral (PT injection, undergo slow vascular uptake and extensive interstitial diffusion, with tumor retention only through integrin molecular recognition. To demonstrate DMR, RGD (integrin binding and RAD (control probes were synthesized bearing DOTA (for (111 In(3+, a NIR fluorochrome, and 5 kDa PEG that endows probes with a protein-like volume of 25 kDa and decreases non-specific interactions. With a GFP-BT-20 breast carcinoma model, tumor targeting by the DMR or i.v. methods was assessed by surface fluorescence, biodistribution of [(111In] RGD and [(111In] RAD probes, and whole animal SPECT. After a PT injection, both probes rapidly diffused through the normal and tumor interstitium, with retention of the RGD probe due to integrin interactions. With PT injection and the [(111In] RGD probe, SPECT indicated a highly tumor specific uptake at 24 h post injection, with 352%ID/g tumor obtained by DMR (vs 4.14%ID/g by i.v.. The high efficiency molecular targeting of DMR employed low probe doses (e.g. 25 ng as RGD peptide, which minimizes toxicity risks and facilitates clinical translation. DMR applications include the delivery of fluorochromes for intraoperative tumor margin delineation, the delivery of radioisotopes (e.g. toxic, short range alpha emitters for radiotherapy, or the delivery of photosensitizers to tumors accessible to light.

  11. Measuring the value of customer retention

    Energy Technology Data Exchange (ETDEWEB)

    Monts, K.; Bonevac, B.; Lauer, J.; Tessema, D.

    1997-05-01

    Competition will require changes in how market research is conducted and how customers are pursued. The question remains: How does one approach customer retention in a way that provides meaningful guidelines? The conventional wisdom is that {open_quotes}the business of business is selling.{close_quotes} There is some truth to this, but the key question today is: What bearing does this have on how to run a business in a competitive environment? A recent article in the Harvard Business Review noted that, {open_quotes}Increasingly, companies are less focused on selling products and more interested in keeping customers.{close_quotes} Indeed, some observers have posited a natural societal evolutionary trend toward a shift of emphasis toward customer retention vis-a-vis customer acquisition, as a consequence of the primary marketing communication technology shifting from {open_quotes}broadcast{close_quotes} (where messages are sent out to inchoate masses) to {open_quotes}interactive{close_quotes} (where relationships are cultivated with precisely defined market niches or individual customers). The business of growing a business, then, can be framed as a matter of getting customers and keeping them so as to grow the value of the customer base to its fullest potential. In these terms, setting a marketing budget becomes the task of balancing what is spent on customer acquisition with what is spent on retention.

  12. Natural flood retention in mountain areas by forests and forest like short rotation coppices

    Science.gov (United States)

    Reinhardt-Imjela, Christian; Schulte, Achim; Hartwich, Jens

    2017-04-01

    the water retention effect decreases. The second factor is the hydraulic behavior of soils. The initial properties of the SRC soils (pore volume, field capacity, hydraulic conductivity etc.) shortly after implementation of the plantation can be assumed to be similar to arable land if there is no prior conditioning such as deep tilling. However with increasing age of the plantation the properties are expected to converge to forest soils with their higher water retention capacities. Accordingly the infiltration potentials of the plantation strongly depends on the development of soil properties underneath. In general it can be concluded that short rotation coppices cannot solve flood problems in mountain areas solely. However together with other natural and distributed measures (e.g. retention basins, reforestation, conservation tillage etc.) they can be interesting elements of flood retention strategies in mountain areas.

  13. Altered histone retention and epigenetic modifications in the sperm of infertile men

    Institute of Scientific and Technical Information of China (English)

    Rafael Oliva; Josep Luís Ballescà

    2012-01-01

    It is well know that the nuclei of spermatogenic cells experience one of the most extremely marked chromatin changes known in cells.At the end of spermatogenesis,the histones are removed in many species and the DNA is condensed by the highly positively charged protamines forming highly compact nucleoprotamine complexes.1-3 In the human mature sperm cell,the nucleoprotamine complexes condense most of the DNA,while 5%-15% of the DNA remains associated to nucleosomes.4,5 For many years,it was thought that the only function of the sperm cell was to transmit the patemal genomic DNA into the next generation.1 This idea started to change with the discovery of sex-specific imprinting of genes mediated through DNA methylation differences set during gametogenesis,and epigenetically transmitted to the next generation.

  14. Retention and chiral recognition mechanism of organo-phosphorus compounds in high-performance liquid chroma-tography

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In normal phase condition, a series of chiral phosphorus organic compounds have been separated by high-performance liquid chromatography. In order to study the retention and chiral recognition mechanism, the method of quantitative structure-enantioselectivity retention relationships (QSERRs) has been investigated from the quantitative equations established between the chromatographic retention of enantiomers and their molecular descriptors of physicochemical properties. The results show that on the Pirkle-type chiral stationary phase (CSP) of Sumichiral OA4700, it is the parameter of LUMO that gives the most contribution to the chromatographic re-tention of O-ethyl O-(substituted) phenyl N-isopropyl phosphoroamidothioates resulting from the interaction of hydrogen bond and (or) p-p interaction. Meanwhile, the chiral recognition is formed from the contribution of logP and LUMO.

  15. Role of glutathione in lung retention of 99mTc-hexamethylpropyleneamine oxime in two unique rat models of hyperoxic lung injury.

    Science.gov (United States)

    Audi, Said H; Roerig, David L; Haworth, Steven T; Clough, Anne V

    2012-08-15

    Rat exposure to 60% oxygen (O(2)) for 7 days (hyper-60) or to >95% O(2) for 2 days followed by 24 h in room air (hyper-95R) confers susceptibility or tolerance, respectively, of the otherwise lethal effects of subsequent exposure to 100% O(2). The objective of this study was to determine if lung retention of the radiopharmaceutical agent technetium-labeled-hexamethylpropyleneamine oxime (HMPAO) is differentially altered in hyper-60 and hyper-95R rats. Tissue retention of HMPAO is dependent on intracellular content of the antioxidant GSH and mitochondrial function. HMPAO was injected intravenously in anesthetized rats, and planar images were acquired. We investigated the role of GSH in the lung retention of HMPAO by pretreating rats with the GSH-depleting agent diethyl maleate (DEM) prior to imaging. We also measured GSH content and activities of mitochondrial complexes I and IV in lung homogenate. The lung retention of HMPAO increased by ≈ 50% and ≈ 250% in hyper-60 and hyper-95R rats, respectively, compared with retention in rats exposed to room air (normoxic). DEM decreased retention in normoxic (≈ 26%) and hyper-95R (≈ 56%) rats compared with retention in the absence of DEM. GSH content increased by 19% and 40% in hyper-60 and hyper-95R lung homogenate compared with normoxic lung homogenate. Complex I activity decreased by ≈ 50% in hyper-60 and hyper-95R lung homogenate compared with activity in normoxic lung homogenate. However, complex IV activity was increased by 32% in hyper-95R lung homogenate only. Furthermore, we identified correlations between the GSH content in lung homogenate and the DEM-sensitive fraction of HMPAO retention and between the complex IV/complex I activity ratio and the DEM-insensitive fraction of HMPAO retention. These results suggest that an increase in the GSH-dependent component of the lung retention of HMPAO may be a marker of tolerance to sustained exposure to hyperoxia.

  16. HEATING AND AIR CONDITIONING EDUCATIONAL PROGRAM.

    Science.gov (United States)

    Lennox Industries, Inc., Marshalltown, IA.

    INCREASED MOTIVATION, INCREASED INITIAL COMPREHENSION, AND INCREASED RETENTION ARE THE PRIME GOALS OF THE LENNOX HEATING AND AIR CONDITIONING EDUCATION PROGRAM. IT IS A COMPLETE PROGRAM WITH ALL THE TEACHING TOOLS REQUIRED TO PRODUCE A KNOWLEDGEABLE HEATING AND AIR-CONDITIONING INSTALLER OR SERVICE MAN. THIS INSTRUCTIONAL PROGRAM IS DESIGNED…

  17. Modelling glass alteration in an altered argillaceous environment

    Science.gov (United States)

    Bildstein, O.; Trotignon, L.; Pozo, C.; Jullien, M.

    2007-05-01

    The long term behaviour of materials such as glass, steel and clay has been investigated in the context of deep geological disposal of radioactive wastes. The interactions between vitrified wastes, canister corrosion products (CPs) and clay are studied using a modified version of the reaction-transport code Crunch, especially looking at pH changes and possible cementation at the interface with the clayey materials. These perturbations may indeed affect the lifetime of glass matrix in deep repositories, e.g., high pH enhances the rate of glass alteration. This work focuses on the argillite of Bure. The calculations were performed at 323 K with a glass alteration rate switching from a high initial rate to a residual rate according to the sorption capacity of CPs. The time at which this sorption capacity is saturated is crucial to the system in terms of wastes package lifetime. The results show that the glass alteration imposes a high pH value at the interface with CPs and clay: up to a value of 9.2, compared to 7.3 which is the initial pH value in the argillite. Experimental data show that the rate of glass alteration is much higher in such pH conditions. For a R7T7-type glass, the rate is about five times higher at pH 9 than at pH 7. This pH perturbation migrates through the clayey domain as a result of the migration of mobile elements such as boron and sodium, and despite the existence of strong pH buffers in the argillite. The cementation of porosity at the interface between glass and clay is predicted by the model due to the massive precipitation of iron corrosion products and glass alteration products. At this point of the evolution of the system, the pH starts to decrease and the alteration rate of the glass could be significantly reduced. This porosity clogging effect is difficult to confirm by experiments especially since existing data on short term experiments tend to show a pervasive precipitation of silica in the domain instead of a localized precipitation

  18. Alignment of retention time obtained from multicapillary column gas chromatography used for VOC analysis with ion mobility spectrometry.

    Science.gov (United States)

    Perl, Thorsten; Bödeker, Bertram; Jünger, Melanie; Nolte, Jürgen; Vautz, Wolfgang

    2010-07-01

    Multicapillary column (MCC) ion mobility spectrometers (IMS) are increasingly in demand for medical diagnosis, biological applications and process control. In a MCC-IMS, volatile compounds are differentiated by specific retention time and ion mobility when rapid preseparation techniques are applied, e.g. for the analysis of complex and humid samples. Therefore, high accuracy in the determination of both parameters is required for reliable identification of the signals. The retention time in the MCC is the subject of the present investigation because, for such columns, small deviations in temperature and flow velocity may cause significant changes in retention time. Therefore, a universal correction procedure would be a helpful tool to increase the accuracy of the data obtained from a gas-chromatographic preseparation. Although the effect of the carrier gas flow velocity and temperature on retention time is not linear, it could be demonstrated that a linear alignment can compensate for the changes in retention time due to common minor deviations of both the carrier gas flow velocity and the column temperature around the MCC-IMS standard operation conditions. Therefore, an effective linear alignment procedure for the correction of those deviations has been developed from the analyses of defined gas mixtures under various experimental conditions. This procedure was then applied to data sets generated from real breath analyses obtained in clinical studies using different instruments at different measuring sites for validation. The variation in the retention time of known signals, especially for compounds with higher retention times, was significantly improved. The alignment of the retention time--an indispensable procedure to achieve a more precise identification of analytes--using the proposed method reduces the random error caused by small accidental deviations in column temperature and flow velocity significantly.

  19. Implicit characteristic parameter of a programmed temperature retention index database

    Institute of Scientific and Technical Information of China (English)

    孙亦梁; 黄爱今; 王青清; 韦平

    1996-01-01

    In a programmed temperature retention index (PTRI) database, there exists a characteristic parameter rt0/β that can be calculated if the experimental parameters are clearly given. This characteristic parameter can be used to flexibly reproduce the original PTRI data under chromatographic conditions different from those originally given. As this characteristic parameter is not explicitly given, it is suggested to name this parameter as the implicit characteristic parameter (TCP) of a PTRI database. The ICP in White’s PTRI database was easily found and used satisfactorily to reproduce PTRI of some test compounds using either a Hewlett-Packard ultra-performance OV-1 column or a self-coated OV-1 column. The reproduction of PTRI could not be realized on columns of different materials. The fact that several PTRI databases measured on glass capillary columns could not satisfactorily be reproduced on fused silica column is explained.

  20. Shape retention of injection molded stainless steel compacts

    Institute of Scientific and Technical Information of China (English)

    LI Yi-min; K.A.Khalil; HUANG Bai-yun

    2005-01-01

    The effects of the binder composition, the powder loading, the thermal properties of feedstocks, and the injection molding parameters on the compact shape retention for metal injection molding 17-4PH stainless steel were investigated. The high-density polyethylene is more effective than ethylene vinyl acetate as a second component of the wax-based binder to retain compact shape due to its higher pyrolytic temperature and less heat of fusion. The compact distortion decreases with increasing the powder loading, molding pressure and molding temperature. There exists an optimal process combination including the powder loading of 68%, molding pressure of 120 MPa and molding temperature of 150 ℃. Under this process condition, the percentage of distorted compacts is the lowest.

  1. The effect of post-learning presentation of music on long-term word-list retention.

    Science.gov (United States)

    Judde, Sarah; Rickard, Nikki

    2010-07-01

    Memory consolidation processes occur slowly over time, allowing recently formed memories to be altered soon after acquisition. Although post-learning arousal treatments have been found to modulate memory consolidation, examination of the temporal parameters of these effects in humans has been limited. In the current study, 127 participants learned a neutral word list and were exposed to either a positively or negatively arousing musical piece following delays of 0, 20 or 45min. One-week later, participants completed a long-term memory recognition test, followed by Carver and White's (1994) approach/avoidance personality scales. Retention was significantly enhanced, regardless of valence, when the emotion manipulation occurred at 20min, but not immediately or 45min, post-learning. Further, the 20min interval effect was found to be moderated by high 'drive' approach sensitivity. The selective facilitatory conditions of music identified in the current study (timing and personality) offer valuable insights for future development of more specified memory intervention strategies.

  2. Genetics Home Reference: chylomicron retention disease

    Science.gov (United States)

    ... a rare condition with approximately 40 cases described worldwide. Related Information What information about a genetic condition can statistics provide? Why are some genetic conditions more common ...

  3. Association between Odontogenic Conditions and Maxillary Sinus Disease: A Study Using Cone-beam Computed Tomography.

    Science.gov (United States)

    Nascimento, Eduarda Helena Leandro; Pontual, Maria Luiza A; Pontual, Andrea A; Freitas, Deborah Q; Perez, Danyel E Cruz; Ramos-Perez, Flávia M M

    2016-10-01

    The maxillary sinus can be affected by dental infections because of its close relationship with upper teeth. This study aimed to assess the most common types of maxillary sinus alterations and to associate them with odontogenic conditions using cone-beam computed tomographic (CBCT) images. CBCT scans of 400 patients showing sinus disease in 1 or both maxillary sinuses were evaluated. Sinus alteration was considered as follows: generalized or localized mucosal thickening (MT), maxillary sinusitis (MS), and retention cysts (RCs). The odontogenic conditions evaluated were inadequate endodontic treatment, periapical lesions, and periodontal bone loss. Descriptive and multiple logistic regression analyses were performed. Sinus diseases were observed in 85.9% of the maxillary sinuses. The most prevalent condition was generalized MT (65.2%) followed by localized MT (24.8%), MS (6.4%), and RCs (3.6%). Generalized MT was more related to males (odds ratio = 1.45, P teeth and the sinus floor (odds ratio = 2.77, P sinus diseases were the generalized and localized MT, and they were the only ones related to odontogenic conditions (periodontal bone loss and periapical lesions, respectively). We emphasize that CBCT imaging is an appropriate method for evaluating the maxillary sinus findings and their associated odontogenic conditions. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Optimal sludge retention time for a bench scale MBR treating municipal sewage.

    Science.gov (United States)

    Pollice, A; Laera, G; Saturno, D; Giordano, C; Sandulli, R

    2008-01-01

    Membrane bioreactors allow for higher sludge concentrations and improved degradation efficiencies with respect to conventional activated sludge. However, in the current practice these systems are often operated under sub-optimal conditions, since so far no precise indications have yet been issued on the optimal operating conditions of MBR for municipal wastewater treatment. This paper reports some results of four years of operation of a bench scale membrane bioreactor where steady state conditions were investigated under different sludge retention times. The whole experimental campaign was oriented towards the investigation of optimal process conditions in terms of COD removal and nitrification, biomass activity and growth, and sludge characteristics. The membrane bioreactor treated real municipal sewage, and four different sludge ages were tested (20, 40, 60, and 80 days) and compared with previous data on complete sludge retention. The results showed that the the biology of the system, as assessed by the oxygen uptake rate, is less affected than the sludge physical parameters. In particular, although the growth yield was observed to dramatically drop for SRT higher than 80 days, the biological activity was maintained under all the tested conditions. These considerations suggest that high SRT are convenient in terms of limited excess sludge production without losses of the treatment capacity. Physical characteristics such as the viscosity and the filterability appear to be negatively affected by prolonged sludge retention times, but their values remain within the ranges normally reported for conventional activated sludge.

  5. Potential retention effect at fish farms boosts zooplankton abundance

    Science.gov (United States)

    Fernandez-Jover, D.; Toledo-Guedes, K.; Valero-Rodríguez, J. M.; Fernandez-Gonzalez, V.; Sanchez-Jerez, P.

    2016-11-01

    Coastal aquaculture activities influence wild macrofauna in natural environments due to the introduction of artificial structures, such as floating cages, that provide structural complexity in the pelagic system. This alters the abundance and distribution of the affected species and also their feeding behaviour and diet. Despite this, the effects of coastal aquaculture on zooplankton assemblages and the potential changes in their abundance and distribution remain largely unstudied. Traditional plankton sampling hauls between the farm mooring systems entail some practical difficulties. As an alternative, light traps were deployed at 2 farms in the SW Mediterranean during a whole warm season. Total zooplankton capture by traps at farms was higher than at control locations on every sampling night. It ranged from 3 to 10 times higher for the taxonomic groups: bivalvia, cladocera, cumacea, fish early-life-stages, gastropoda, polychaeta and tanaidacea; 10-20 times higher for amphipoda, chaetognatha, isopoda, mysidacea and ostracoda, and 22 times higher for copepoda and the crustacean juvenile stages zoea and megalopa. Permutational analysis showed significant differences for the most abundant zooplankton groups (copepoda, crustacean larvae, chaetognatha, cladocera, mysidacea and polychaeta). This marked incremental increase in zooplankton taxa at farms was consistent, irrespective of the changing environmental variables registered every night. Reasons for the greater abundance of zooplankton at farms are discussed, although results suggest a retention effect caused by cage structures rather than active attraction through physical or chemical cues.

  6. Increase in seizure susceptibility in sepsis like condition explained by spiking cytokines and altered adhesion molecules level with impaired blood brain barrier integrity in experimental model of rats treated with lipopolysaccharides.

    Science.gov (United States)

    Sewal, Rakesh K; Modi, Manish; Saikia, Uma Nahar; Chakrabarti, Amitava; Medhi, Bikash

    2017-09-01

    Epilepsy is a neurological disorder characterized by recurrent unprovoked seizures. Sepsis is a condition which initiates a cascade of a surge of inflammatory mediators. Interplay between seizures and inflammation other than of brain origin is yet to be explored. The present study was designed to evaluate the seizure susceptibility in experimental models of lipopolysaccharide (LPS) induced sepsis. Experimental sepsis was induced using lipopolysaccharides in Wistar rats. Valproic acid, dexametasone were given to two different groups of animals along with LPS. Two groups of animals were subjected to administration of vehicle and LPS respectively with no other treatment. 24h later, animals were subjected to seizures by using either maximal electro shock or pentylenetetrazole. Seizures related parameters, oxidative stress and TNF-α, IL-6, IL-1β, ICAM-1, ICAM-2, VCAM-1, MMP-9 level in serum and brain samples were evaluated. Histopathological and blood brain barrier permeability studies were conducted. Seizures were decreased in valproic acid treated animals. Reduced oxidative stress was seen in dexamethasone plus valproic acid treated groups as compared to LPS alone treated group. TNF-α, IL-6, IL-1β, ICAM-1, VCAM-1, MMP-9 levels were found increased in LPS treated animals whereas a reverse observation was noted for ICAM-2 level in brain and serum. Histopathological findings confirmed the successful establishment of sepsis like state in animals. Blood brain barrier permeability was found increased in LPS treated groups of animals. Seizure susceptibility may escalate during the sepsis like inflammatory conditions and curbing the inflammatory state might reverse the phenomenon. Copyright © 2017. Published by Elsevier B.V.

  7. Student retention in athletic training education programs.

    Science.gov (United States)

    Dodge, Thomas M; Mitchell, Murray F; Mensch, James M

    2009-01-01

    The success of any academic program, including athletic training, depends upon attracting and keeping quality students. The nature of persistent students versus students who prematurely leave the athletic training major is not known. Understanding the profiles of athletic training students who persist or leave is important. To (1) explore the relationships among the following variables: anticipatory factors, academic integration, clinical integration, social integration, and motivation; (2) determine which of the aforementioned variables discriminate between senior athletic training students and major changers; and (3) identify which variable is the strongest predictor of persistence in athletic training education programs. Descriptive study using a qualitative and quantitative mixed-methods approach. Thirteen athletic training education programs located in District 3 of the National Athletic Trainers' Association. Ninety-four senior-level athletic training students and 31 college students who changed majors from athletic training to another degree option. Data were collected with the Athletic Training Education Program Student Retention Questionnaire (ATEPSRQ). Data from the ATEPSRQ were analyzed via Pearson correlations, multivariate analysis of variance, univariate analysis of variance, and a stepwise discriminant analysis. Open-ended questions were transcribed and analyzed using open, axial, and selective coding procedures. Member checks and peer debriefing techniques ensured trustworthiness of the study. Pearson correlations identified moderate relationships among motivation and clinical integration (r = 0.515, P students. Understanding student retention in athletic training is important for our profession. Results from this study suggest 3 key factors associated with student persistence in athletic training education programs: (1) student motivation, (2) clinical and academic integration, and (3) the presence of a peer-support system. Educators and program

  8. Psychogenic urine retention during doping controls

    DEFF Research Database (Denmark)

    Elbe, Anne-Marie; Schlegel, Marius M.; Brand, Ralf

    2012-01-01

    relation to recovery, performance, and self-perception of professionalism and athletic excellence. Furthermore, a scale developed especially for the close description and measurement of PURD is presented. A questionnaire was used for measuring paruresis. The results are based on two online and one paper...... and pencil study involving 222 German-speaking athletes from various sports. The results indicate that 60% of these athletes have experienced psychogenic urine retention during doping controls, with only 39% of them showing symptoms of paruresis. PURD impacts athlete recovery and self...

  9. Clasp retention and composites: an abrasion study.

    Science.gov (United States)

    Davenport, J C; Hawamdeh, K; Harrington, E; Wilson, H J

    1990-08-01

    An in vitro test for screening the abrasion resistance and abrasivity of composite resins when used to provide tooth undercuts for removable partial denture clasps is described. In the present study nine composite resins were tested against wrought stainless steel round clasps. The results indicated that the abrasion of any of the composites tested was unlikely to cause a noticeable loss of retention in the clinical situation. However, there was marked abrasion of the clasps by two of the composites which would be likely to be clinically relevant.

  10. Retention and failure morphology of prefabricated posts

    DEFF Research Database (Denmark)

    Sahafi, Alireza; Peutzfeldt, Anne; Asmussen, Erik

    2004-01-01

    PURPOSE: This study evaluated the effect of cement, post material, surface treatment, and shape (1) on the retention of posts luted in the root canals of extracted human teeth and (2) on the failure morphology. MATERIALS AND METHODS: Posts of titanium alloy (ParaPost XH), glass fiber (Para......Post Fiber White), and zirconia (Cerapost) received one of several surface treatments-sandblasting, CoJet treatment, application of Metalprimer II, or sandblasting followed by silane application-and were then luted in the prepared root canal of human incisors and canines (n = 10). Following water storage...

  11. Evaluation of the retention pattern on ionic liquid columns for gas chromatographic analyses of fatty acid methyl esters.

    Science.gov (United States)

    Lin, Chen-Chen; Wasta, Ziar; Mjøs, Svein A

    2014-07-11

    Fatty acid methyl esters from marine sources were analyzed by gas chromatography-mass spectrometry on three ionic liquid columns, SLB-IL61, SLB-IL82 and SLB-IL100 (Supelco). Retention indices (equivalent chain lengths) are reported for more than 100 compounds and the overlap patterns are evaluated from these data. The influence of chromatographic conditions on the retention indices of unsaturated fatty acid methyl esters is also evaluated. Compared to typical alternative phases the retention patterns on all three columns are highly dependent on the conditions. The SLB-IL61 phase had overlaps between nutritionally important fatty acids that could not be resolved by changing the chromatographic conditions. This column is therefore regarded as unsuitable for clinical and nutritional studies of the fatty acid composition, but similar overlaps may be avoided on IL82 and IL100. On all three columns double bonds close to the carboxyl group in the analytes contribute with limited retention, which makes it challenging to predict the retention of polyunsaturated fatty acid methyl esters.

  12. Multiple pixel-scale soil water retention curves quantified by neutron radiography

    Science.gov (United States)

    Kang, M.; Perfect, E.; Cheng, C. L.; Bilheux, H. Z.; Lee, J.; Horita, J.; Warren, J. M.

    2014-03-01

    The soil water retention function is needed for modeling multiphase flow in porous media. Traditional techniques for measuring the soil water retention function, such as the hanging water column or pressure cell methods, yield average water retention data which have to be modeled using inverse procedures to extract relevant point parameters. In this study, we have developed a technique for directly measuring multiple point (pixel-scale) water retention curves for a repacked sand material using 2-D neutron radiography. Neutron radiographic images were obtained under quasi-equilibrium conditions at nine imposed basal matric potentials during monotonic drying of Flint sand at the High Flux Isotope Reactor (HFIR) Cold Guide (CG) 1D beamline at Oak Ridge National Laboratory. All of the images were normalized with respect to an image of the oven dry sand column. Volumetric water contents were computed on a pixel by pixel basis using an empirical calibration equation after taking into account beam hardening and geometric corrections. Corresponding matric potentials were calculated from the imposed basal matric potential and pixel elevations. Volumetric water content and matric potential data pairs corresponding to 120 selected pixels were used to construct 120 point water retention curves. Each curve was fitted to the Brooks and Corey equation using segmented non-linear regression in SAS. A 98.5% convergence rate was achieved resulting in 115 estimates of the four Brooks and Corey parameters. A single Brooks and Corey point water retention function was constructed for Flint sand using the median values of these parameter estimates. This curve corresponded closely with the point Brooks and Corey function inversely extracted from the average water retention data using TrueCell. Forward numerical simulations performed using HYDRUS 1-D showed that the cumulative outflows predicted using the point Brooks and Corey functions from both the direct (neutron radiography) and

  13. Attention Alters Perceived Attractiveness.

    Science.gov (United States)

    Störmer, Viola S; Alvarez, George A

    2016-04-01

    Can attention alter the impression of a face? Previous studies showed that attention modulates the appearance of lower-level visual features. For instance, attention can make a simple stimulus appear to have higher contrast than it actually does. We tested whether attention can also alter the perception of a higher-order property-namely, facial attractiveness. We asked participants to judge the relative attractiveness of two faces after summoning their attention to one of the faces using a briefly presented visual cue. Across trials, participants judged the attended face to be more attractive than the same face when it was unattended. This effect was not due to decision or response biases, but rather was due to changes in perceptual processing of the faces. These results show that attention alters perceived facial attractiveness, and broadly demonstrate that attention can influence higher-level perception and may affect people's initial impressions of one another.

  14. Football and Freshmen Retention: Examining the Impact of College Football on Institutional Retention Rates

    Science.gov (United States)

    Jones, Willis A.

    2010-01-01

    Student retention has been one of the more researched topics in the study of American higher education over the past 20 years (Braxton, Hirschy, & McClendon, 2004; Pascarella & Terenzini, 2005). Very little of this research, however, has attempted to examine the impact of college athletics on an institution's ability to retain students. This…

  15. Football and Freshmen Retention: Examining the Impact of College Football on Institutional Retention Rates

    Science.gov (United States)

    Jones, Willis A.

    2010-01-01

    Student retention has been one of the more researched topics in the study of American higher education over the past 20 years (Braxton, Hirschy, & McClendon, 2004; Pascarella & Terenzini, 2005). Very little of this research, however, has attempted to examine the impact of college athletics on an institution's ability to retain students.…

  16. Football and Freshmen Retention: Examining the Impact of College Football on Institutional Retention Rates

    Science.gov (United States)

    Jones, Willis A.

    2010-01-01

    Student retention has been one of the more researched topics in the study of American higher education over the past 20 years (Braxton, Hirschy, & McClendon, 2004; Pascarella & Terenzini, 2005). Very little of this research, however, has attempted to examine the impact of college athletics on an institution's ability to retain students.…

  17. Mechanistic failure mode investigation and resolution of parvovirus retentive filters.

    Science.gov (United States)

    LaCasse, Daniel; Lute, Scott; Fiadeiro, Marcus; Basha, Jonida; Stork, Matthew; Brorson, Kurt; Godavarti, Ranga; Gallo, Chris

    2016-07-01

    Virus retentive filters are a key product safety measure for biopharmaceuticals. A simplistic perception is that they function solely based on a size-based particle removal mechanism of mechanical sieving and retention of particles based on their hydrodynamic size. Recent observations have revealed a more nuanced picture, indicating that changes in viral particle retention can result from process pressure and/or flow interruptions. In this study, a mechanistic investigation was performed to help identify a potential mechanism leading to the reported reduced particle retention in small virus filters. Permeate flow rate or permeate driving force were varied and analyzed for their impact on particle retention in three commercially available small virus retentive filters. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:959-970, 2016.

  18. Gender differences in problem severity at assessment and treatment retention.

    Science.gov (United States)

    Arfken, C L; Klein, C; di Menza, S; Schuster, C R

    2001-01-01

    Women in treatment for substance abuse have been reported to have more severe problems at assessment than men but not to differ in treatment retention. To examine gender differences in problems at assessment, 30-day retention, and treatment completion, data from Detroit's publicly funded substance abuse treatment system were used. Women had significantly more severe problems at assessment, lower 30-day retention, and lower treatment completion rates than men. These gender differences in retention remained significant even after controlling for problem severity, primary drug of abuse, and referred treatment setting. There was no evidence of improvements in women's problems at assessment or retention over time during this period. Women presented with more severe problems at assessment and were less likely to stay in treatment for 30 days or to complete treatment than men. Monitoring gender differences in problems at presentation and retention outcomes is recommended to assess local need for interventions.

  19. Laboratory and Field Investigations of Dynamic Effects in Soil Water Retention Curve

    Science.gov (United States)

    Chiu, Yung-Chia; Tseng, Yen-Huiang; Ye, Jiun-Yan

    2015-04-01

    The unsaturated soil is a multi-phase system and the embedded physical mechanisms and chemical reactions are very complicated. The characteristics of groundwater flow and mechanisms of mass transport are still ambiguous so far. In order to fully understand the flow and transport in the unsaturated zone, the soil water retention curve plays an important role in description of water flow. However, the measurements and calculations of soil water retention curve are usually obtained under the static condition or steady state (equilibrium), in which the dynamic effects (non-equilibrium) are not considered, and the obtained relationship between capillary pressure and saturation is skeptical. Therefore, the sandbox experiments and field tests will be conducted to discuss the dynamic effects in the soil water retention curve and hysteresis effect in this study. In the laboratory, the relations between capillary pressure, saturation, the rate of change of water content, and dynamic constant are evaluated through different setting of boundary conditions and different sizes of particles. In the field, the tests are conducted to describe the soil water retention curve through the rain simulator and artificial evaporation. Besides, the dynamic dewpoint potentiameter is used to analyze the hysteresis effect of soil samples, and its results are compared with the results obtained from sandbox and field experiments. Finally, through a series of experiments, the relationship between capillary pressure and saturation under the dynamic effects is established, and the associated theories and mechanisms are discussed. The works developed in this study can provide as reference tools for the hydrogeological investigation and contaminated site remediation in the future. Keywords: capillary pressure, saturation, soil water retention curve, hysteresis, sandbox experiment, field test

  20. Modeling of the Transport and Retention of Fullerene C60 Aggregates in Porous Media

    Science.gov (United States)

    Li, Y.; Wang, Y.; Pennell, K.; Abriola, L.

    2008-12-01

    Buckminster fullerene (C60) has recently gained wide application in many commercial products. Given its widespread use, release of C60 into the environment during manufacture, transportation, and/or application is likely. Although C60 has negligible solubility in water, it is capable of acquiring charge and form highly stable nano-scale aggregates (nC60) in aqueous systems. In recent years, several laboratory research efforts have been devoted to studying the potential fate and transport of nC60 in porous media representative of the natural subsurface environment. Traditional clean-bed filtration theory is typically applied to analyze the experimental results. Far less attention has focused on the applicability of filtration theory to nC60 transport under different soil and solution conditions. In this work, we simulate column transport of nC60 under progressively more complex conditions and compare with laboratory observations. For nC60 transport in columns packed with Ottawa sand and simple electrolyte solutions, i.e. 1mM CaCl2 and 1mM NaCl, simulation results reveal that traditional clean-bed filtration theory is not sufficient to model the asymmetric breakthrough curves and relatively flat retention profiles observed in these systems. Modification of the filtration model, incorporating a maximum retention capacity term, can provide remarkably improved modeling results. The second application is for transport of nC60 in Ottawa sand coated with surfactant. The observed retention profiles in these experiments exhibit a hyper-exponential feature. Modeling results demonstrate that coupled simulation of both surfactant and nC60 transport is required to correctly capture the hyper-exponential retention profile in these systems. Finally, efforts to model the transport of nC60 in real soils, including Appling and Webster soils, are presented, suggesting that modification of filtration theory is also necessary in this case, to capture the shape of the observed retention

  1. Micromechanical analysis of water retention phenomenon

    Science.gov (United States)

    Gras, J.-P.; Delenne, J.-Y.; Soulié, F.; El Youssoufi, M. S.

    2009-06-01

    We investigate the water distribution and the link between suction and water content in granular media. Firstly, we examine the effect of suction on the shape and the volume of the liquid bridge for different parameters (grain radius, inter-particle distance, contact angle, surface tension). This local behaviour is then used in a discrete element study of a sample composed of several thousands of grains. We focus our study on the pendular state. The existence of a liquid film around the grains which involves the continuity of the liquid phase is assumed. The water distribution and the water content associated with a given suction are calculated. Then retention curves of the granular media are built. Four different methods are used. The first is based on the local expression of the capillary force coupled with the "gorge method," the second is based on the Laplace equation, and the third and the fourth are based on the integration of the differential equation that defines the liquid bridge shape. A parametric study is made to bring to light the effect of macroscopic parameters (grain-size distribution, density) and physical parameters (liquid/air surface tension, contact angle) on the water retention curve. Finally, numerical data are compared to experimental results.

  2. Retention of Halogens in Waste Glass

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R.

    2010-05-01

    In spite of their potential roles as melting rate accelerators and foam breakers, halogens are generally viewed as troublesome components for glass processing. Of five halogens, F, Cl, Br, I, and At, all but At may occur in nuclear waste. A nuclear waste feed may contain up to 10 g of F, 4 g of Cl, and ≤100 mg of Br and I per kg of glass. The main concern is halogen volatility, producing hazardous fumes and particulates, and the radioactive iodine 129 isotope of 1.7x10^7-year half life. Because F and Cl are soluble in oxide glasses and tend to precipitate on cooling, they can be retained in the waste glass in the form of dissolved constituents or as dispersed crystalline inclusions. This report compiles known halogen-retention data in both high-level waste (HLW) and low-activity waste (LAW) glasses. Because of its radioactivity, the main focus is on I. Available data on F and Cl were compiled for comparison. Though Br is present in nuclear wastes, it is usually ignored; no data on Br retention were found.

  3. Husband's Esteem Predicts his Mate Retention Tactics

    Directory of Open Access Journals (Sweden)

    Christopher J. Holden

    2014-07-01

    Full Text Available delity or prevent their defection from the relationship. These tactics include low-risk acts that render the current relationship more attractive by bestowing benefits on the woman, as well as cost-inflicting acts that render defection from the relationship risky or dangerous for her. Previous research has linked men's mate retention behavior with men's mate value (value as a current or potential partner using women's reports. The current research addresses limitations of that research using self-reports and cross-spousal reports from 107 married couples concerning their self-esteem and their esteem for their partner. The results indicate that the level of esteem that wives have for their husbands is positively associated with their perception of their husband's use of positive inducements and negatively associated with their husband's self-reported use of cost-inflicting mate retention behaviors (i.e., Direct Guarding, Intersexual Negative Inducements, and Intrasexual Negative Inducements. The level of self-esteem reported by men was negatively associated with their self-reported direct guarding behavior. Discussion explores the possibility that esteem—both self-esteem and esteem from one's partner—functions as an internal gauge of relative mate value.

  4. Retention of Halogens in Waste Glass

    Energy Technology Data Exchange (ETDEWEB)

    Hrma, Pavel R.

    2010-05-01

    In spite of their potential roles as melting rate accelerators and foam breakers, halogens are generally viewed as troublesome components for glass processing. Of five halogens, F, Cl, Br, I, and At, all but At may occur in nuclear waste. A nuclear waste feed may contain up to 10 g of F, 4 g of Cl, and ≤100 mg of Br and I per kg of glass. The main concern is halogen volatility, producing hazardous fumes and particulates, and the radioactive iodine 129 isotope of 1.7x10^7-year half life. Because F and Cl are soluble in oxide glasses and tend to precipitate on cooling, they can be retained in the waste glass in the form of dissolved constituents or as dispersed crystalline inclusions. This report compiles known halogen-retention data in both high-level waste (HLW) and low-activity waste (LAW) glasses. Because of its radioactivity, the main focus is on I. Available data on F and Cl were compiled for comparison. Though Br is present in nuclear wastes, it is usually ignored; no data on Br retention were found.

  5. Retention and resistance of preparations for cast restorations.

    Science.gov (United States)

    Potts, R G; Shillingburg, H T; Duncanson, M G

    1980-03-01

    Five preparation designs were tested for retention and resistance. Retention values for all partial veneer crowns were significantly lower than those for the complete veneer crown. Resistance values increased significantly with the addition of grooves and/or extension of axial surface coverage. Addition of grooves and/or extension of axial surface coverage produced small increases in retention values but marked increases in resistance values.

  6. Job embeddedness as a nurse retention strategy for rural hospitals.

    Science.gov (United States)

    Stroth, Chandra

    2010-01-01

    RN turnover is expensive and disruptive for rural hospitals, constraining finances, impacting patient care, and stressing remaining nurses. Recent investigations have described a promising new construct related to employee retention: job embeddedness. Leaders in nonhealthcare organizations have adopted a job-embeddedness model to guide retention strategies and experienced a subsequent reduction in turnover. The author explores job embeddedness as an effective retention plan strategy for rural hospitals.

  7. Learning communities: the link to recruitment and retention.

    Science.gov (United States)

    Bassi, Sherry; Polifroni, E Carol

    2005-01-01

    The professional learning community is a strategy to help staff development educators address recruitment and retention and organizational culture. The purpose of this article is to analyze the concept of learning communities and discuss their potential to increase the recruitment and retention of new graduate nurses and returning practitioners to the nursing profession. Incorporating learning communities into the healthcare organization will decrease the number of nurses leaving nursing, foster retention, and thus, enhance recruitment.

  8. Air Force Pilot Retention: A Look at 1996

    Science.gov (United States)

    1990-04-07

    PILOT RETENTION A LOOK AT 1996 BY COLONEL DANIEL F . CRUM DISTRIBUTIlON STATEMENT A: Approved f or public releasel distribution to un1ated. 7 APRIL 1990...by the appropriate mli.tar- service or government agency. AIR FORCE PILOT RETENTION A LOOK AT 1996 AN INDIVIDUAL STUDY PROJECT by Colonel Daniel F . Crum...35 I ABSTRACT AUTHOR: Daniel F . Crum TITLE: Air Force Pilot Retention: A Look at 1996 FORMAT: Individual Study

  9. EFFECTS OF ANISOMYCIN ON RETENTION OF THE PASSIVE-AVOIDANCE HABIT AS A FUNCTION OF AGE

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Hasker P.; Rosenzweig, Mark R.; Kinkade, Patrick T.; Bennett, Edward L.

    1980-09-01

    Three age groups of male Swiss albino CD-1 mice (2-3 mo, 6-7 mo, and 14-15 mo) were treated with a 120 mg/kg dose of the protein synthesis inhibitor anisomycin or with an equal volume of saline at various times before and after training (20 min pretraining, 0, 10, 30, and 180 min posttraining) in a shock motivated passive-avoidance task. Young (2-3 mo) and intermediate-aged (6-7 mo) mice treated with anisomycin before or immediately after training demonstrated impaired retention at a 7 day test, but retention was normal for mice injected 10, 30, or 180 min posttraining. The older mice (14-15 mo) showed similar results, with one exception: Those older mice injected with anisomycin 10 min posttraining were significantly impared in retention as compared to older saline controls and to identically treated young or intermediate-aged mice. The prolonged gradient of retrograde amnesia demonstrated by older mice could not be accounted for by impaired acquisition, impaired short-term memory, altered spontaneous locomotor activity, or differential inhibition of brain protein synthesis.

  10. Retention and release mechanisms of deuterium implanted into beryllium

    Science.gov (United States)

    Oberkofler, M.; Reinelt, M.; Linsmeier, Ch.

    2011-06-01

    The fraction of deuterium (D) that is retained upon irradiation of beryllium (Be) as well as the temperatures at which implanted D is released are of importance for the international fusion experiment ITER, where Be will be used as an armor material. The influence of single parameters on retention and release is investigated in laboratory experiments performed under well defined conditions with the aim to identify dominant underlying mechanisms and thus be able to predict the behavior of the Be wall in ITER. Recent progress in the quantification of retained fractions and release temperatures as well as in the understanding of the governing mechanisms is presented. The retained fraction upon implantation of D at 1 keV into Be(1 1 2¯ 0) to fluences far below the saturation threshold of 10 21 m -2 is almost 95%, the remaining 5% being attributed to reflection at the surface. At these low fluences, no dependence of the retained fractions on implantation energy is observed. At fluences of the order of 10 21 m -2 and higher, saturation of the irradiated material affects the retention, leading to lower retained fractions. Furthermore, at these fluences the retained fractions decrease with decreasing implantation energies. Differences in the retained fractions from implanted Be(1 1 2¯ 0) and polycrystalline Be are explained by anisotropic diffusion of interstitials during implantation, leading to an amount of surviving D-trap complexes that depends on surface-orientation. Temperature-programmed desorption (TPD) spectra are recorded after implantation of fluences of the order of 10 19 m -2 at various energies and simulated by means of a newly developed code based on coupled reaction-diffusion systems (CRDS). The asymmetric shape of the TPD peaks is reproduced by introducing a local D accumulation process into the model.

  11. Working without accumulation membrane in flow field-flow fractionation. Effect of sample loading on retention.

    Science.gov (United States)

    Melucci, Dora; Zattoni, Andrea; Casolari, Sonia; Reggiani, Matteo; Sanz, Ramses; Reschiglian, Pierluigi; Torsi, Giancarlo

    2004-03-01

    Membraneless hyperlayer flow field-flow fractionation (Hyp FIFFF) has shown improved performance with respect to Hyp FIFFF with membrane. The conditions for high recovery and recovery independent of sample loading in membraneless Hyp FIFFF have been previously determined. The effect of sample loading should be also investigated in order to optimize the form of the peaks for real samples. The effect of sample loading on peak retention parameters is of prime importance in applications such as the conversion of peaks into particle size distributions. In this paper, a systematic experimental work is performed in order to study the effect of sample loading on retention parameters. A procedure to regenerate the frit operating as accumulation wall is described. High reproducibility is obtained with low system conditioning time.

  12. The effect of hydrate saturation on water retention curves in hydrate-bearing sediments

    Science.gov (United States)

    Mahabadi, Nariman; Zheng, Xianglei; Jang, Jaewon

    2016-05-01

    The experimental measurement of water retention curve in hydrate-bearing sediments is critically important to understand the behavior of hydrate dissociation and gas production. In this study, tetrahydrofuran (THF) is selected as hydrate former. The pore habit of THF hydrates is investigated by visual observation in a transparent micromodel. It is confirmed that THF hydrates are not wetting phase on the quartz surface of the micromodel and occupy either an entire pore or part of pore space resulting in change in pore size distribution. And the measurement of water retention curves in THF hydrate-bearing sediments with hydrate saturation ranging from Sh = 0 to Sh = 0.7 is conducted for excess water condition. The experimental results show that the gas entry pressure and the capillary pressure increase with increasing hydrate saturation. Based on the experimental results, fitting parameters for van Genuchten equation are suggested for different hydrate saturation conditions.

  13. Modelling of the water retention characteristic of deformable soils

    Directory of Open Access Journals (Sweden)

    Wang Yu

    2016-01-01

    Full Text Available A recently proposed water retention model has been further developed for the application on unsaturated deformable soils. The physical mechanisms underpinning the water retention characteristic of soils was at first described in terms of traditional theories of capillarity and interfacial physical chemistry at pore level. Then upscaling to macroscopic level of material scale in terms of average volume theorem produces an analytical formula for the water retention characteristic. The methodology produces an explicit form of the water retention curve as a function of three state parameters: the suction, the degree-of-water-saturation and the void-ratio. At last, the model has been tested using experimental measurements.

  14. A causal involvement of the left supramarginal gyrus during the retention of musical pitches.

    Science.gov (United States)

    Schaal, Nora K; Williamson, Victoria J; Kelly, Maria; Muggleton, Neil G; Pollok, Bettina; Krause, Vanessa; Banissy, Michael J

    2015-03-01

    Brain stimulation studies have previously demonstrated a causal link between general pitch memory processes and activity within the left supramarginal gyrus (SMG). Building on this evidence, the present study tested the impact of left SMG stimulation on two distinct pitch memory phases, retention and encoding. Repetitive transcranial magnetic stimulation (rTMS) was employed during the retention stage (Experiment 1) and the encoding phase (Experiment 2) of a pitch recognition task. Stimulation was applied on a trial-by-trial basis over the left SMG (target site) or the vertex (control site). A block without TMS was also completed. In Experiment 1, rTMS over the left SMG during pitch retention led to significantly increased reaction times compared to control conditions. In Experiment 2 no rTMS modulation effects were found during encoding. Experiment 3 was conducted as a control for non-specific stimulation effects; no effects were found when rTMS was applied over the left SMG at the two different time points during a perceptual task. Taken together, these findings highlight a phase-specific involvement of the left SMG in the retention phase of pitch memory, thereby indicating that the left SMG is involved in the maintenance of pitch information. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Influence of particle flux density and temperature on surface modifications of tungsten and deuterium retention

    Energy Technology Data Exchange (ETDEWEB)

    Buzi, Luxherta, E-mail: l.buzi@fz-juelich.de [Ghent University, Department of Applied Physics, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium); FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Institut für Energie und Klimaforschung – Plasmaphysik, Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52425 Jülich (Germany); Université de Lorraine, Institut Jean Lamour, CNRS UMR 7198, Bvd. des Aiguillettes, F-54506 Vandoeuvre (France); Temmerman, Greg De [FOM Institute DIFFER-Dutch Institute for Fundamental Energy Research, Edisonbaan 14, 3439 MN, PO Box 1207, 3430 BE Nieuwegein (Netherlands); Unterberg, Bernhard; Reinhart, Michael; Litnovsky, Andrey; Philipps, Volker [Institut für Energie und Klimaforschung – Plasmaphysik, Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52425 Jülich (Germany); Oost, Guido Van [Ghent University, Department of Applied Physics, Sint-Pietersnieuwstraat 41, B-9000 Ghent (Belgium); Möller, Sören [Institut für Energie und Klimaforschung – Plasmaphysik, Forschungszentrum Jülich GmbH, Leo-Brandt-Straße, 52425 Jülich (Germany)

    2014-12-15

    Systematic study of deuterium irradiation effects on tungsten was done under ITER – relevant high particle flux density, scanning a broad surface temperature range. Polycrystalline ITER – like grade tungsten samples were exposed in linear plasma devices to two different ranges of deuterium ion flux densities (high: 3.5–7 · 10{sup 23} D{sup +}/m{sup 2} s and low: 9 · 10{sup 21} D{sup +}/m{sup 2} s). Particle fluence and ion energy, respectively 10{sup 26} D{sup +}/m{sup 2} and ∼38 eV were kept constant in all cases. The experiments were performed at three different surface temperatures 530 K, 630 K and 870 K. Experimental results concerning the deuterium retention and surface modifications of low flux exposure confirmed previous investigations. At temperatures 530 K and 630 K, deuterium retention was higher at lower flux density due to the longer exposure time (steady state plasma operation) and a consequently deeper diffusion range. At 870 K, deuterium retention was found to be higher at high flux density according to the thermal desorption spectroscopy (TDS) measurements. While blisters were completely absent at low flux density, small blisters of about 40–50 nm were formed at high flux density exposure. At the given conditions, a relation between deuterium retention and blister formation has been found which has to be considered in addition to deuterium trapping in defects populated by diffusion.

  16. Prediction of retention time in reversed-phase liquid chromatography as a tool for steroid identification

    Energy Technology Data Exchange (ETDEWEB)

    Randazzo, Giuseppe Marco [School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva (Switzerland); Tonoli, David [School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva (Switzerland); Swiss Centre for Applied Human Toxicology (SCAHT), Universities of Basel and Geneva, Basel (Switzerland); Human Protein Sciences Department, University of Geneva, Geneva (Switzerland); Hambye, Stephanie; Guillarme, Davy [School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva (Switzerland); Jeanneret, Fabienne [School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva (Switzerland); Swiss Centre for Applied Human Toxicology (SCAHT), Universities of Basel and Geneva, Basel (Switzerland); Human Protein Sciences Department, University of Geneva, Geneva (Switzerland); Nurisso, Alessandra [School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva (Switzerland); Goracci, Laura [Department of Chemistry, Biology and Biotechnology, University of Perugia, Perugia (Italy); Boccard, Julien [School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva (Switzerland); Rudaz, Serge, E-mail: serge.rudaz@unige.ch [School of Pharmaceutical Sciences, University of Geneva and University of Lausanne, Geneva (Switzerland); Swiss Centre for Applied Human Toxicology (SCAHT), Universities of Basel and Geneva, Basel (Switzerland)

    2016-04-15

    The untargeted profiling of steroids constitutes a growing research field because of their importance as biomarkers of endocrine disruption. New technologies in analytical chemistry, such as ultra high-pressure liquid chromatography coupled with mass spectrometry (MS), offer the possibility of a fast and sensitive analysis. Nevertheless, difficulties regarding steroid identification are encountered when considering isotopomeric steroids. Thus, the use of retention times is of great help for the unambiguous identification of steroids. In this context, starting from the linear solvent strength (LSS) theory, quantitative structure retention relationship (QSRR) models, based on a dataset composed of 91 endogenous steroids and VolSurf + descriptors combined with a new dedicated molecular fingerprint, were developed to predict retention times of steroid structures in any gradient mode conditions. Satisfactory performance was obtained during nested cross-validation with a predictive ability (Q{sup 2}) of 0.92. The generalisation ability of the model was further confirmed by an average error of 4.4% in external prediction. This allowed the list of candidates associated with identical monoisotopic masses to be strongly reduced, facilitating definitive steroid identification. - Highlights: • Difficulties regarding steroid identification are encountered when considering isotopomeric steroids. • Quantitative structure retention relationship (QSRR) models were developed from the linear solvent strength theory. • A dataset composed of 91 steroids and VolSurf + descriptors combined with a new dedicated molecular fingerprint, were used. • The list of candidates associated with identical monoisotopic masses was reduced, facilitating steroid identification.

  17. RETENTION AND PAPER-STRENGTH CHARACTERISTICS OF ANIONIC POLYACRYLAMIDES CONJUGATED WITH CARBOHYDRATE-BINDING MODULES

    Directory of Open Access Journals (Sweden)

    Shingo Yokota

    2009-02-01

    Full Text Available The retention behavior of polymers having the specific affinities of glyco-hydrolases for pulp fibers was investigated with regard to paper-strength enhancement in contaminated papermaking systems. Carbohydrate-binding modules (CBMs of cellulases derived from Trichoderma viride and T. reesei, and of xylanase from Thermomyces lanuginosus, were obtained by site-directed digestion with papain, then introduced into anionic polyacrylamide (A-PAM via a peptide condensation reaction. Three types of CBM-conjugated A-PAMs (CBM-A-PAMs displayed different retention behavior, depending on the kind of pulp substrates, i.e. hardwood and softwood fibers. The CBM-A-PAM from T. viride demonstrated good additive retention for hardwood pulp fibers, resulting in high tensile strength of paper sheets, even under contaminated conditions in the presence of Ca2+ ions and ligninsulfonate. The CBM-A-PAM from T. reesei showed better performance for softwood than for hardwood sheets. The xylanase CBM-A-PAM was preferentially retained on hardwood fibers in which hemicelluloses might be present. Such an additive retention system, with inherent affinities of enzymes for pulp fibers, is expected to expand the application range of CBM-polymers in practical wet-end processes.

  18. Retention behavior of phenols, anilines, and alkylbenzenes in liquid chromatographic separations using subcritical water as the mobile phase.

    Science.gov (United States)

    Yang, Y; Jones, A D; Eaton, C D

    1999-09-01

    The unique characteristic of subcritical water is its widely tunable physical properties. For example, the polarity (measured by dielectric constant) of water is significantly decreased by raising water temperature. At temperatures of 200-250 °C (under moderate pressure to keep water in the liquid state), the polarity of pure water is similar to that of pure methanol or acetonitrile at ambient conditions. Therefore, pure subcritical water may be able to serve as the mobile phase for reversed-phase separations. To investigate the retention behavior in subcritical water separation, the retention factors of BTEX (benzene, toluene, ethylbenzene, and m-xylene), phenol, aniline, and their derivatives have been determined using subcritical water, methanol/water, and acetonitrile/water systems. Subcritical water separations were also performed using alumina, silica-bonded C18, and poly(styrene-divinylbenzene) columns to study the influence of the stationary phase on analyte retention under subcritical water conditions.

  19. Method for training honeybees to respond to olfactory stimuli and enhancement of memory retention therein

    Energy Technology Data Exchange (ETDEWEB)

    McCade, Kirsten J.; Wingo, Robert M.; Haarmann, Timothy K.; Sutherland, Andrew; Gubler, Walter D.

    2015-12-15

    A specialized conditioning protocol for honeybees that is designed for use within a complex agricultural ecosystem. This method ensures that the conditioned bees will be less likely to exhibit a conditioned response to uninfected plants, a false positive response that would render such a biological sensor unreliable for agricultural decision support. Also described is a superboosting training regime that allows training without the aid of expensive equipment and protocols for training in out in the field. Also described is a memory enhancing cocktail that aids in long term memory retention of a vapor signature. This allows the bees to be used in the field for longer durations and with fewer bees trained overall.

  20. A Survey of Olivine Alteration Products Using Raman Spectroscopy

    Science.gov (United States)

    Kuebler, K.; Jolliff, B. L.; Wang, A.; Haskin, L. A.

    2004-01-01

    Identification of mineral alteration products will aid in the crucial task of interpreting past Martian environmental conditions, especially aqueous environments. Olivine has been identified at the surface of Mars and is readily altered in aqueous environments. Using Raman spectroscopy, we studied three rocks with altered olivine and compared the data with mineral chemistry from electron microprobe analysis. Although the alteration in all three samples has loosely been called iddingsite their appearances and modes of occurrences differ as described. Alteration products in all three samples are likely fine-grained mixtures.