The spectrum of R Cygni during its exceptionally low maximum of 1983

International Nuclear Information System (INIS)

Wallerstein, G.; Dominy, J.F.; Mattei, J.A.; Smith, V.V.

1985-01-01

In 1983 R Cygni experienced its faintest maximum ever recorded. A study of the light curve shows correlations between brightness at maximum and interval from the previous cycle, in the sense that fainter maxima occur later than normal and are followed by maxima that occur earlier than normal. Emission and absorption lines in the optical and near infrared (2.2 μm region) reveal two significant correlations. The amplitude of line doubling is independent of the magnitude at maximum for msub(v)(max)=7.1 to 9.8. The velocities of the emission lines, however, correlate with the magnitude at maximum, in that during bright maxima they are negatively displaced by 15 km s -1 with respect to the red component of absorption lines, while during the faintest maximum there is no displacement. (author)

Directional spike propagation in a recurrent network: dynamical firewall as anisotropic recurrent inhibition.

Science.gov (United States)

Samura, Toshikazu; Hayashi, Hatsuo

2012-09-01

It has been demonstrated that theta rhythm propagates along the septotemporal axis of the hippocampal CA1 of the rat running on a track, and it has been suggested that directional spike propagation in the hippocampal CA3 is reflected in CA1. In this paper, we show that directional spike propagation occurs in a recurrent network model in which neurons are connected locally and connection weights are modified through STDP. The recurrent network model consists of excitatory and inhibitory neurons, which are intrinsic bursting and fast spiking neurons developed by Izhikevich, respectively. The maximum length of connections from excitatory neurons is shorter in the horizontal direction than the vertical direction. Connections from inhibitory neurons have the same maximum length in both directions, and the maximum length of inhibitory connections is the same as that of excitatory connections in the vertical direction. When connection weights between excitatory neurons (E→E) were modified through STDP and those from excitatory neurons to inhibitory neurons (E→I) were constant, spikes propagated in the vertical direction as expected from the network structure. However, when E→I connection weights were modified through STDP, as well as E→E connection weights, spikes propagated in the horizontal direction against the above expectation. This paradoxical propagation was produced by strengthened E→I connections which shifted the timing of inhibition forward. When E→I connections are enhanced, the direction of effective inhibition changes from horizontal to vertical, as if a gate for spike propagation is opened in the horizontal direction and firewalls come out in the vertical direction. These results suggest that the advance of timing of inhibition caused by potentiation of E→I connections is influential in network activity and is an important element in determining the direction of spike propagation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Compilation of minimum and maximum isotope ratios of selected elements in naturally occurring terrestrial materials and reagents

Science.gov (United States)

Coplen, T.B.; Hopple, J.A.; Böhlke, J.K.; Peiser, H.S.; Rieder, S.E.; Krouse, H.R.; Rosman, K.J.R.; Ding, T.; Vocke, R.D.; Revesz, K.M.; Lamberty, A.; Taylor, P.; De Bievre, P.

2002-01-01

laboratories comparable. The minimum and maximum concentrations of a selected isotope in naturally occurring terrestrial materials for selected chemical elements reviewed in this report are given below: Isotope Minimum mole fraction Maximum mole fraction -------------------------------------------------------------------------------- 2H 0 .000 0255 0 .000 1838 7Li 0 .9227 0 .9278 11B 0 .7961 0 .8107 13C 0 .009 629 0 .011 466 15N 0 .003 462 0 .004 210 18O 0 .001 875 0 .002 218 26Mg 0 .1099 0 .1103 30Si 0 .030 816 0 .031 023 34S 0 .0398 0 .0473 37Cl 0 .240 77 0 .243 56 44Ca 0 .020 82 0 .020 92 53Cr 0 .095 01 0 .095 53 56Fe 0 .917 42 0 .917 60 65Cu 0 .3066 0 .3102 205Tl 0 .704 72 0 .705 06 The numerical values above have uncertainties that depend upon the uncertainties of the determinations of the absolute isotope-abundance variations of reference materials of the elements. Because reference materials used for absolute isotope-abundance measurements have not been included in relative isotope abundance investigations of zinc, selenium, molybdenum, palladium, and tellurium, ranges in isotopic composition are not listed for these elements, although such ranges may be measurable with state-of-the-art mass spectrometry. This report is available at the url: http://pubs.water.usgs.gov/wri014222.

Inhibition of polo-like kinase-1 by DNA damage occurs in an ATM- or ATR-dependent fashion

NARCIS (Netherlands)

van Vugt, MATM; Smits, VAJ; Klompmaker, R; Medema, RH

2001-01-01

Polo-like kinases play multiple roles in different phases of mitosis. We have recently shown that the mammalian polo-like kinase, Plk1, is inhibited in response to DNA damage and that this inhibition may lead to cell cycle arrests at multiple points in mitosis. Here we have investigated the role of

Maximum Water Hammer Sensitivity Analysis

OpenAIRE

Jalil Emadi; Abbas Solemani

2011-01-01

Pressure waves and Water Hammer occur in a pumping system when valves are closed or opened suddenly or in the case of sudden failure of pumps. Determination of maximum water hammer is considered one of the most important technical and economical items of which engineers and designers of pumping stations and conveyance pipelines should take care. Hammer Software is a recent application used to simulate water hammer. The present study focuses on determining significance of ...

Solar maximum mission

International Nuclear Information System (INIS)

Ryan, J.

1981-01-01

By understanding the sun, astrophysicists hope to expand this knowledge to understanding other stars. To study the sun, NASA launched a satellite on February 14, 1980. The project is named the Solar Maximum Mission (SMM). The satellite conducted detailed observations of the sun in collaboration with other satellites and ground-based optical and radio observations until its failure 10 months into the mission. The main objective of the SMM was to investigate one aspect of solar activity: solar flares. A brief description of the flare mechanism is given. The SMM satellite was valuable in providing information on where and how a solar flare occurs. A sequence of photographs of a solar flare taken from SMM satellite shows how a solar flare develops in a particular layer of the solar atmosphere. Two flares especially suitable for detailed observations by a joint effort occurred on April 30 and May 21 of 1980. These flares and observations of the flares are discussed. Also discussed are significant discoveries made by individual experiments

Inhibition of lactation.

Science.gov (United States)

Llewellyn-Jones, D

1975-01-01

The mechanism and hormonal regulation of lactation is explained and illustrated with a schematic representation. Circulating estrogen above a critical amount seems to be the inhibitory factor controlling lactation during pregnancy. Once delivery occurs, the level of estrogen falls, that of prolactin rises, and lactation begins. Nonsuckling can be used to inhibit lactation. Estrogens can also be used to inhibit lactation more quickly and with less pain. The reported association between estrogens and puerperal thromboembolism cannot be considered conclusive due to defects in the reporting studies. There is no reason not to use estrogens in lactation inhibition except for women over 35 who experienced a surgical delivery. Alternative therapy is available for these women. The recently-developed drug, brom-ergocryptine, may replace other methods of lactation inhibition.

Partial inhibition of in vitro pollen germination by simulated solar ultraviolet-B radiation

International Nuclear Information System (INIS)

Flint, S.D.; Caldwell, M.M.

1984-01-01

Pollen from four temperate-latitude taxa were treated with UV radiation in a portion of the UV-B (280-320 nm) waveband during in vitro germination. Inhibition of germination was noted in this pollen compared to samples treated identically except for the exclusion of the UV-B portion of the spectrum. Levels similar to maximum solar UV-B found in temperate-latitude areas failed to inhibit pollen germination significantly, while levels similar to maximum solar UV-B found in equatorial alpine locations caused partial inhibition of germination in three of the four taxa examined

Extreme Maximum Land Surface Temperatures.

Science.gov (United States)

Garratt, J. R.

1992-09-01

There are numerous reports in the literature of observations of land surface temperatures. Some of these, almost all made in situ, reveal maximum values in the 50°-70°C range, with a few, made in desert regions, near 80°C. Consideration of a simplified form of the surface energy balance equation, utilizing likely upper values of absorbed shortwave flux (1000 W m2) and screen air temperature (55°C), that surface temperatures in the vicinity of 90°-100°C may occur for dry, darkish soils of low thermal conductivity (0.1-0.2 W m1 K1). Numerical simulations confirm this and suggest that temperature gradients in the first few centimeters of soil may reach 0.5°-1°C mm1 under these extreme conditions. The study bears upon the intrinsic interest of identifying extreme maximum temperatures and yields interesting information regarding the comfort zone of animals (including man).

Parametric optimization of thermoelectric elements footprint for maximum power generation

DEFF Research Database (Denmark)

Rezania, A.; Rosendahl, Lasse; Yin, Hao

2014-01-01

The development studies in thermoelectric generator (TEG) systems are mostly disconnected to parametric optimization of the module components. In this study, optimum footprint ratio of n- and p-type thermoelectric (TE) elements is explored to achieve maximum power generation, maximum cost......-performance, and variation of efficiency in the uni-couple over a wide range of the heat transfer coefficient on the cold junction. The three-dimensional (3D) governing equations of the thermoelectricity and the heat transfer are solved using the finite element method (FEM) for temperature dependent properties of TE...... materials. The results, which are in good agreement with the previous computational studies, show that the maximum power generation and the maximum cost-performance in the module occur at An/Ap

Comprehensive performance analyses and optimization of the irreversible thermodynamic cycle engines (TCE) under maximum power (MP) and maximum power density (MPD) conditions

International Nuclear Information System (INIS)

Gonca, Guven; Sahin, Bahri; Ust, Yasin; Parlak, Adnan

2015-01-01

This paper presents comprehensive performance analyses and comparisons for air-standard irreversible thermodynamic cycle engines (TCE) based on the power output, power density, thermal efficiency, maximum dimensionless power output (MP), maximum dimensionless power density (MPD) and maximum thermal efficiency (MEF) criteria. Internal irreversibility of the cycles occurred during the irreversible-adiabatic processes is considered by using isentropic efficiencies of compression and expansion processes. The performances of the cycles are obtained by using engine design parameters such as isentropic temperature ratio of the compression process, pressure ratio, stroke ratio, cut-off ratio, Miller cycle ratio, exhaust temperature ratio, cycle temperature ratio and cycle pressure ratio. The effects of engine design parameters on the maximum and optimal performances are investigated. - Highlights: • Performance analyses are conducted for irreversible thermodynamic cycle engines. • Comprehensive computations are performed. • Maximum and optimum performances of the engines are shown. • The effects of design parameters on performance and power density are examined. • The results obtained may be guidelines to the engine designers

The first occurence of a pleistocenic coral along the Brazilian coast - Age dating of the maximum of the penultimate transgression

International Nuclear Information System (INIS)

Martin, L.; Bittencourt, A.C.S.P.; Silva Vilas Boas, G. da

1982-01-01

Age dating work on a coral from Olivenca, Bahia, Brazil, has disclosed the first occurrence of a pleistocenic coral along the Brazilian coast. This coral has its top at the present high tide level and is covered by a series of beach-ridges formed after the maximum of the penultimate transgression that rose above present sea level. Five determinations by the Ionium ( 230 Th)/Uranium method produced ages ranging from 116.000 to 142.000 years B.P., indicating that maximum in the area to have taken place 120.000-125.000 years B.P., consistent with its documentation in other parts of the world. At that time, mean sea level was 8 + - 2 m above the present. (Author) [pt

Evaluation of the role of damage to photosystem II in the inhibition of CO2 assimilation in pea leaves on exposure to UV-B radiation

International Nuclear Information System (INIS)

Nogues, S.; Baker, N.R.

1995-01-01

Mature pea (Pisum sativum L., cv. Meteor) leaves were exposed to two levels of UV-B radiation, with and without supplementary UV-C radiation, during 15 h photoperiods. Simultaneous measurements of CO 2 assimilation and modulated chlorophyll fluorescence parameters demonstrated that irradiation with UV-B resulted in decreases in CO 2 assimilation that are not accompanied by decreases in the maximum quantum efficiency of photosystem II (PSII) primary photochemistry. Increased exposure to UV-B resulted in a further loss of CO 2 assimilation and decreases in the maximum quantum efficiency of PSII primary photochemistry, which were accompanied by a loss of the capacity of thylakoids isolated from the leaves to bind atrazine, thus demonstrating that photodamage to PSII reaction centres had occurred. Addition of UV-C to the UV-B treatments increased markedly the rate of inhibition of photosynthesis, but the relationships between CO 2 assimilation and PSII characteristics remained the same, indicating that UV-B and UV-C inhibit leaf photosynthesis by a similar mechanism. It is concluded that PSII is not the primary target site involved in the onset of the inhibition of photosynthesis in pea leaves induced by irradiation with UV-B. (author)

Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings 1

Science.gov (United States)

Creelman, Robert A.; Mason, Hugh S.; Bensen, Robert J.; Boyer, John S.; Mullet, John E.

1990-01-01

Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite. Images Figure 6 Figure 7 PMID:16667248

In-shoe plantar tri-axial stress profiles during maximum-effort cutting maneuvers.

Science.gov (United States)

Cong, Yan; Lam, Wing Kai; Cheung, Jason Tak-Man; Zhang, Ming

2014-12-18

Soft tissue injuries, such as anterior cruciate ligament rupture, ankle sprain and foot skin problems, frequently occur during cutting maneuvers. These injuries are often regarded as associated with abnormal joint torque and interfacial friction caused by excessive external and in-shoe shear forces. This study simultaneously investigated the dynamic in-shoe localized plantar pressure and shear stress during lateral shuffling and 45° sidestep cutting maneuvers. Tri-axial force transducers were affixed at the first and second metatarsal heads, lateral forefoot, and heel regions in the midsole of a basketball shoe. Seventeen basketball players executed both cutting maneuvers with maximum efforts. Lateral shuffling cutting had a larger mediolateral braking force than 45° sidestep cutting. This large braking force was concentrated at the first metatarsal head, as indicated by its maximum medial shear stress (312.2 ± 157.0 kPa). During propulsion phase, peak shear stress occurred at the second metatarsal head (271.3 ± 124.3 kPa). Compared with lateral shuffling cutting, 45° sidestep cutting produced larger peak propulsion shear stress (463.0 ± 272.6 kPa) but smaller peak braking shear stress (184.8 ± 181.7 kPa), of which both were found at the first metatarsal head. During both cutting maneuvers, maximum medial and posterior shear stress occurred at the first metatarsal head, whereas maximum pressure occurred at the second metatarsal head. The first and second metatarsal heads sustained relatively high pressure and shear stress and were expected to be susceptible to plantar tissue discomfort or injury. Due to different stress distribution, distinct pressure and shear cushioning mechanisms in basketball footwear might be considered over different foot regions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inhibition of the coated vesicle proton pump and labeling of a 17,000-dalton polypeptide by N,N'-dicyclohexylcarbodiimide

International Nuclear Information System (INIS)

Arai, H.; Berne, M.; Forgac, M.

1987-01-01

N,N'-Dicyclohexylcarbodiimide (DCCD) inhibits 100% of proton transport and 80-85% of (Mg2+)-ATPase activity in clathrin-coated vesicles. Half-maximum inhibition of proton transport is observed at 10 microM DCCD after 30 min. Although treatment of the coated vesicle (H+)-ATPase with DCCD has no effect on ATP hydrolysis in the detergent-solubilized state, sensitivity of proton transport and ATPase activity to DCCD is restored following reconstitution into phospholipid vesicles. In addition, treatment of the detergent-solubilized enzyme with DCCD followed by reconstitution gives a preparation that is blocked in both proton transport and ATP hydrolysis. These results suggest that although the coated vesicle (H+)-ATPase can react with DCCD in either a membrane-bound or detergent-solubilized state, inhibition of ATPase activity is only manifested when the pump is present in sealed membrane vesicles. To identify the subunit responsible for inhibition of the coated vesicle (H+)-ATPase by DCCD, we have labeled the partially purified enzyme with [ 14 C]DCCD. A single polypeptide of molecular weight 17,000 is labeled. The extremely hydrophobic nature of this polypeptide is indicated by its extraction with chloroform:methanol. The 17,000-dalton protein can be labeled to a maximum stoichiometry of 0.99 mol of DCCD/mol of protein with 100% inhibition of proton transport occurring at a stoichiometry of 0.15-0.20 mol of DCCD/mol of protein. Amino acid analysis of the chloroform:methanol extracted 17,000-dalton polypeptide reveals a high percentage of nonpolar amino acids. The similarity in properties of this protein and the DCCD-binding subunit of the coupling factor (H+)-ATPases suggests that the 17,000-dalton polypeptide may function as part of a proton channel in the coated vesicle proton pump

Combined MEK and ERK inhibition overcomes therapy-mediated pathway reactivation in RAS mutant tumors.

Directory of Open Access Journals (Sweden)

Mark Merchant

Full Text Available Mitogen-activated protein kinase (MAPK pathway dysregulation is implicated in >30% of all cancers, rationalizing the development of RAF, MEK and ERK inhibitors. While BRAF and MEK inhibitors improve BRAF mutant melanoma patient outcomes, these inhibitors had limited success in other MAPK dysregulated tumors, with insufficient pathway suppression and likely pathway reactivation. In this study we show that inhibition of either MEK or ERK alone only transiently inhibits the MAPK pathway due to feedback reactivation. Simultaneous targeting of both MEK and ERK nodes results in deeper and more durable suppression of MAPK signaling that is not achievable with any dose of single agent, in tumors where feedback reactivation occurs. Strikingly, combined MEK and ERK inhibition is synergistic in RAS mutant models but only additive in BRAF mutant models where the RAF complex is dissociated from RAS and thus feedback productivity is disabled. We discovered that pathway reactivation in RAS mutant models occurs at the level of CRAF with combination treatment resulting in a markedly more active pool of CRAF. However, distinct from single node targeting, combining MEK and ERK inhibitor treatment effectively blocks the downstream signaling as assessed by transcriptional signatures and phospho-p90RSK. Importantly, these data reveal that MAPK pathway inhibitors whose activity is attenuated due to feedback reactivation can be rescued with sufficient inhibition by using a combination of MEK and ERK inhibitors. The MEK and ERK combination significantly suppresses MAPK pathway output and tumor growth in vivo to a greater extent than the maximum tolerated doses of single agents, and results in improved anti-tumor activity in multiple xenografts as well as in two Kras mutant genetically engineered mouse (GEM models. Collectively, these data demonstrate that combined MEK and ERK inhibition is functionally unique, yielding greater than additive anti-tumor effects and

Proactive modulation of long-interval intracortical inhibition during response inhibition

Science.gov (United States)

Cowie, Matthew J.; MacDonald, Hayley J.; Cirillo, John

2016-01-01

Daily activities often require sudden cancellation of preplanned movement, termed response inhibition. When only a subcomponent of a whole response must be suppressed (required here on Partial trials), the ensuing component is markedly delayed. The neural mechanisms underlying partial response inhibition remain unclear. We hypothesized that Partial trials would be associated with nonselective corticomotor suppression and that GABAB receptor-mediated inhibition within primary motor cortex might be responsible for the nonselective corticomotor suppression contributing to Partial trial response delays. Sixteen right-handed participants performed a bimanual anticipatory response inhibition task while single- and paired-pulse transcranial magnetic stimulation was delivered to elicit motor evoked potentials in the left first dorsal interosseous muscle. Lift times, amplitude of motor evoked potentials, and long-interval intracortical inhibition were examined across the different trial types (Go, Stop-Left, Stop-Right, Stop-Both). Go trials produced a tight distribution of lift times around the target, whereas those during Partial trials (Stop-Left and Stop-Right) were substantially delayed. The modulation of motor evoked potential amplitude during Stop-Right trials reflected anticipation, suppression, and subsequent reinitiation of movement. Importantly, suppression was present across all Stop trial types, indicative of a “default” nonselective inhibitory process. Compared with blocks containing only Go trials, inhibition increased when Stop trials were introduced but did not differ between trial types. The amount of inhibition was positively correlated with lift times during Stop-Right trials. Tonic levels of inhibition appear to be proactively modulated by task context and influence the speed at which unimanual responses occur after a nonselective “brake” is applied. PMID:27281744

Bioassay of naturally occurring allelochemicals for phytotoxicity.

Science.gov (United States)

Leather, G R; Einhellig, F A

1988-10-01

The bioassay has been one of the most widely used tests to demonstrate allelopathic activity. Often, claims that a particular plant species inhibits the growth of another are based entirely on the seed germination response to solvent extracts of the suspected allelopathic plant; few of these tests are of value in demonstrating allelopathy under natural conditions. The veracity of the bioassay for evaluating naturally occurring compounds for phytotoxicity depends upon the physiological and biochemical response capacity of the bioassay organism and the mechanism(s) of action of the allelochemicals. The possibility that more than one allelochemical, acting in concert at very low concentrations, may be responsible for an observed allelopathic effect makes it imperative that bioassays be extremely sensitive to chemical growth perturbation agents. Among the many measures of phytotoxicity of allelochemicals, the inhibition (or stimulation) of seed germination, radicle elongation, and/or seedling growth have been the parameters of choice for most investigations. Few of these assays have been selected with the view towards the possible mechanism of the allelopathic effect.

Locally formed dopamine inhibits Na+-K+-ATPase activity in rat renal cortical tubule cells

International Nuclear Information System (INIS)

Seri, I.; Kone, B.C.; Gullans, S.R.; Aperia, A.; Brenner, B.M.; Ballermann, B.J.

1988-01-01

Dopamine, generated locally from L-dopa, inhibits Na + -K + -ATPase in permeabilized rat proximal tubules under maximum transport rate conditions for sodium. To determine whether locally formed dopamine inhibits Na + -K + -ATPase activity in intact cortical tubule cells we studied the effect of L-dopa on ouabain-sensitive oxygen consumption rate (Qo 2 ) and 86 Rb uptake in renal cortical tubule cell suspensions. L-Dopa did not affect ouabain-insensitive Qo 2 or mitochondrial respiration. However, L-dopa inhibited ouabain-sensitive Qo 2 in a concentration-dependent manner, with half-maximal inhibition (K 0.5 ) of 5 x 10 -7 M and a maximal inhibition of 14.1 ± 1.5% at 10 -4 M. L-Dopa also blunted the nystatin-stimulated Qo 2 in a concentration-dependent manner, indicating the L-dopa directly inhibits Na + -K + -ATPase activity and not sodium entry. Ouabain-sensitive 86 Rb uptake was also inhibited by L-dopa. Carbidopa, an inhibitor of the conversion of L-dopa to dopamine, eliminated the effect of L-dopa on ouabain-sensitive Qo 2 and 86 Rb uptake, indicating that dopamine rather than L-dopa was the active agent. The finding that the L-dopa concentration-response curve was shifted to the left by one order of magnitude in the presence of nystatin suggests that the inhibitory effect is enhanced when the intracellular sodium concentration is increased. By studying the effect of L-dopa on ouabain-sensitive Qo 2 at increasing extracellular sodium concentrations in the presence of nystatin, the authors demonstrated that the inhibitory effect of locally formed dopamine on the Na + -K + -ATPase is indeed dependent on the sodium available for the enzyme and occurs in an uncompetitive manner

Maximum vehicle cabin temperatures under different meteorological conditions

Science.gov (United States)

Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

2009-05-01

A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76°C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68°C in the summer and 61°C in the spring. Cloudy days in both the spring and summer were on average approximately 10°C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses.

IN VITRO ANTIOXIDANT AND α-AMYLASE INHIBITION ACTIVITIES OF PANCHSAKAR CHURNA

Directory of Open Access Journals (Sweden)

Ashok Kumar B.S.

2013-12-01

Full Text Available Panchsakar Churna is the composition of Cassia angustifolia, Terminalia chebula, Zingiber officinale, Foeniculum vulgare and Saindhava lavana. Aqueous extract of churna was used to investigate antioxidant activity by ferrous ion chelating assay and ferric reducing power and alpha amylase inhibition activity by dinitrosalicylic acid method (DNSA. Aqueous extract of churna showed maximum ferrous chelating activity - 42.01 and ferric reducing power - 1.5 and 83.33 % of inhibition protein denaturation at 1000 µg/ml. Panchsakar churna showed significant antioxidant and alpha amylase inhibition activities.

Acetylcholinesterase assay for cerebrospinal fluid using bupivacaine to inhibit butyrylcholinesterase

Directory of Open Access Journals (Sweden)

Anders Jens

2001-12-01

Full Text Available Abstract Background Most test systems for acetylcholinesterase activity (E.C.3.1.1.7. are using toxic inhibitors (BW284c51 and iso-OMPA to distinguish the enzyme from butyrylcholinesterase (E.C.3.1.1.8. which occurs simultaneously in the cerebrospinal fluid. Applying Ellman's colorimetric method, we were looking for a non-toxic inhibitor to restrain butyrylcholinesterase activity. Based on results of previous in vitro studies bupivacaine emerged to be a suitable inhibitor. Results Pharmacokinetic investigations with purified cholinesterases have shown maximum inhibition of butyrylcholinesterase activity and minimal interference with acetylcholinesterase activity at bupivacaine final concentrations between 0.1 and 0.5 mmol/l. Based on detailed analysis of pharmacokinetic data we developed three equations representing enzyme inhibition at bupivacaine concentrations of 0.1, 0.2 and 0.5 mmol/l. These equations allow us to calculate the acetylcholinesterase activity in solutions containing both cholinesterases utilizing the extinction differences measured spectrophotometrically in samples with and without bupivacaine. The accuracy of the bupivacaine-inhibition test could be confirmed by investigations on solutions of both purified cholinesterases and on samples of human cerebrospinal fluid. If butyrylcholinesterase activity has to be assessed simultaneously an independent test using butyrylthiocholine iodide as substrate (final concentration 5 mmol/l has to be conducted. Conclusions The bupivacaine-inhibition test is a reliable method using spectrophotometrical techniques to measure acetylcholinesterase activity in cerebrospinal fluid. It avoids the use of toxic inhibitors for differentiation of acetylcholinesterase from butyrylcholinesterase in fluids containing both enzymes. Our investigations suggest that bupivacaine concentrations of 0.1, 0.2 or 0.5 mmol/l can be applied with the same effect using 1 mmol/l acetylthiocholine iodide as substrate.

The radial distribution of cosmic rays in the heliosphere at solar maximum

Science.gov (United States)

McDonald, F. B.; Fujii, Z.; Heikkila, B.; Lal, N.

2003-08-01

To obtain a more detailed profile of the radial distribution of galactic (GCRs) and anomalous (ACRs) cosmic rays, a unique time in the 11-year solar activity cycle has been selected - that of solar maximum. At this time of minimum cosmic ray intensity a simple, straight-forward normalization technique has been found that allows the cosmic ray data from IMP 8, Pioneer 10 (P-10) and Voyagers 1 and 2 (V1, V2) to be combined for the solar maxima of cycles 21, 22 and 23. This combined distribution reveals a functional form of the radial gradient that varies as G 0/r with G 0 being constant and relatively small in the inner heliosphere. After a transition region between ˜10 and 20 AU, G 0 increases to a much larger value that remains constant between ˜25 and 82 AU. This implies that at solar maximum the changes that produce the 11-year modulation cycle are mainly occurring in the outer heliosphere between ˜15 AU and the termination shock. These observations are not inconsistent with the concept that Global Merged Interaction. regions (GMIRs) are the principal agent of modulation between solar minimum and solar maximum. There does not appear to be a significant change in the amount of heliosheath modulation occurring between the 1997 solar minimum and the cycle 23 solar maximum.

Inhibition delay increases neural network capacity through Stirling transform

Science.gov (United States)

Nogaret, Alain; King, Alastair

2018-03-01

Inhibitory neural networks are found to encode high volumes of information through delayed inhibition. We show that inhibition delay increases storage capacity through a Stirling transform of the minimum capacity which stabilizes locally coherent oscillations. We obtain both the exact and asymptotic formulas for the total number of dynamic attractors. Our results predict a (ln2) -N-fold increase in capacity for an N -neuron network and demonstrate high-density associative memories which host a maximum number of oscillations in analog neural devices.

Gain control through divisive inhibition prevents abrupt transition to chaos in a neural mass model.

Science.gov (United States)

Papasavvas, Christoforos A; Wang, Yujiang; Trevelyan, Andrew J; Kaiser, Marcus

2015-09-01

Experimental results suggest that there are two distinct mechanisms of inhibition in cortical neuronal networks: subtractive and divisive inhibition. They modulate the input-output function of their target neurons either by increasing the input that is needed to reach maximum output or by reducing the gain and the value of maximum output itself, respectively. However, the role of these mechanisms on the dynamics of the network is poorly understood. We introduce a novel population model and numerically investigate the influence of divisive inhibition on network dynamics. Specifically, we focus on the transitions from a state of regular oscillations to a state of chaotic dynamics via period-doubling bifurcations. The model with divisive inhibition exhibits a universal transition rate to chaos (Feigenbaum behavior). In contrast, in an equivalent model without divisive inhibition, transition rates to chaos are not bounded by the universal constant (non-Feigenbaum behavior). This non-Feigenbaum behavior, when only subtractive inhibition is present, is linked to the interaction of bifurcation curves in the parameter space. Indeed, searching the parameter space showed that such interactions are impossible when divisive inhibition is included. Therefore, divisive inhibition prevents non-Feigenbaum behavior and, consequently, any abrupt transition to chaos. The results suggest that the divisive inhibition in neuronal networks could play a crucial role in keeping the states of order and chaos well separated and in preventing the onset of pathological neural dynamics.

Approximate maximum parsimony and ancestral maximum likelihood.

Science.gov (United States)

Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

2010-01-01

We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP.

Inhibition of apparent photosynthesis by nitrogen oxides

Energy Technology Data Exchange (ETDEWEB)

Hill, A C; Bennett, J H

1970-01-01

The nitrogen oxides (NO/sub 2/ and NO) inhibited apparent photosynthesis of oats and alfalfa at concentrations below those required to cause visible injury. There appeared to be a threshold concentration of about 0.6 ppm for each pollutant. An additive effect in depressing apparent photosynthesis occurred when the plants were exposed to a mixture of NO and NO/sub 2/. Although NO produced a more rapid effect on the plants, lower concentrations of NO/sub 2/ were required to cause a given inhibition after 2 hour of exposure. Inhibition by nitric oxide was more closely related to its partial pressure than was inhibition by NO/sub 2/.

Maximum covariance analysis to identify intraseasonal oscillations over tropical Brazil

Science.gov (United States)

Barreto, Naurinete J. C.; Mesquita, Michel d. S.; Mendes, David; Spyrides, Maria H. C.; Pedra, George U.; Lucio, Paulo S.

2017-09-01

A reliable prognosis of extreme precipitation events in the tropics is arguably challenging to obtain due to the interaction of meteorological systems at various time scales. A pivotal component of the global climate variability is the so-called intraseasonal oscillations, phenomena that occur between 20 and 100 days. The Madden-Julian Oscillation (MJO), which is directly related to the modulation of convective precipitation in the equatorial belt, is considered the primary oscillation in the tropical region. The aim of this study is to diagnose the connection between the MJO signal and the regional intraseasonal rainfall variability over tropical Brazil. This is achieved through the development of an index called Multivariate Intraseasonal Index for Tropical Brazil (MITB). This index is based on Maximum Covariance Analysis (MCA) applied to the filtered daily anomalies of rainfall data over tropical Brazil against a group of covariates consisting of: outgoing longwave radiation and the zonal component u of the wind at 850 and 200 hPa. The first two MCA modes, which were used to create the { MITB}_1 and { MITB}_2 indices, represent 65 and 16 % of the explained variance, respectively. The combined multivariate index was able to satisfactorily represent the pattern of intraseasonal variability over tropical Brazil, showing that there are periods of activation and inhibition of precipitation connected with the pattern of MJO propagation. The MITB index could potentially be used as a diagnostic tool for intraseasonal forecasting.

Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings : Analysis of Growth, Sugar Accumulation, and Gene Expression.

Science.gov (United States)

Creelman, R A; Mason, H S; Bensen, R J; Boyer, J S; Mullet, J E

1990-01-01

Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite.

Acumulación de hojarasca en un pastizal de Panicum maximum y en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala Litter accumulation in a Panicum maximum grassland and in a silvopastoral system of Panicum maximum and Leucaena leucocephala

Directory of Open Access Journals (Sweden)

Saray Sánchez

2007-09-01

Full Text Available Se realizó un estudio en la Estación Experimental de Pastos y Forrajes "Indio Hatuey", Matanzas, Cuba, con el objetivo de determinar la acumulación de la hojarasca en un pastizal de Panicum maximum Jacq cv. Likoni y en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham. En los pastizales de P. maximum de ambos sistemas se determinó la acumulación de la hojarasca según la técnica propuesta por Bruce y Ebershon (1982, mientras que la hojarasca de L. leucocephala acumulada en el sistema silvopastoril se determinó según Santa Regina et al. (1997. De forma general, los resultados demostraron que en ambos pastizales la guinea acumuló una menor cantidad de hojarasca durante el período junio-diciembre, etapa en la que se produce su mayor desarrollo vegetativo. En la leucaena la mayor producción de hojarasca ocurrió en el período de diciembre a enero, asociada con la caída natural de sus hojas que se produce por efecto de las temperaturas más bajas y la escasa humedad en el suelo. En el sistema silvopastoril la hojarasca de leucaena representó el mayor porcentaje de peso dentro de la producción total, con un contenido más alto de nitrógeno y de calcio que el de la hojarasca del estrato herbáceo. En la guinea la lluvia fue el factor climático que mayor correlación negativa presentó con la producción de hojarasca en ambos sistemas, y en la leucaena la mayor correlación negativa se encontró con la temperatura mínima.A study was carried out at the Experimental Station of Pastures and Forages "Indio Hatuey", Matanzas, Cuba, with the objective of determining the litter accumulation in a pastureland of Panicum maximum Jacq cv. Likoni and in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham. In the P. maximum pasturelands of both systems the litter accumulation was determined by means of the technique proposed by Bruce and Ebershon (1982, while

Nipah virus entry can occur by macropinocytosis

International Nuclear Information System (INIS)

Pernet, Olivier; Pohl, Christine; Ainouze, Michelle; Kweder, Hasan; Buckland, Robin

2009-01-01

Nipah virus (NiV) is a zoonotic biosafety level 4 paramyxovirus that emerged recently in Asia with high mortality in man. NiV is a member, with Hendra virus (HeV), of the Henipavirus genus in the Paramyxoviridae family. Although NiV entry, like that of other paramyxoviruses, is believed to occur via pH-independent fusion with the host cell's plasma membrane we present evidence that entry can occur by an endocytic pathway. The NiV receptor ephrinB2 has receptor kinase activity and we find that ephrinB2's cytoplasmic domain is required for entry but is dispensable for post-entry viral spread. The mutation of a single tyrosine residue (Y304F) in ephrinB2's cytoplasmic tail abrogates NiV entry. Moreover, our results show that NiV entry is inhibited by constructions and drugs specific for the endocytic pathway of macropinocytosis. Our findings could potentially permit the rapid development of novel low-cost antiviral treatments not only for NiV but also HeV.

Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, {alpha}-D-Glucose and Tannic acid)

Energy Technology Data Exchange (ETDEWEB)

Ostovari, A. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)], E-mail: A.Ostovari@gmail.com; Hoseinieh, S.M.; Peikari, M. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Shadizadeh, S.R. [Petroleum Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Hashemi, S.J. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)

2009-09-15

The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, {alpha}-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > {alpha}-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, α-D-Glucose and Tannic acid)

International Nuclear Information System (INIS)

Ostovari, A.; Hoseinieh, S.M.; Peikari, M.; Shadizadeh, S.R.; Hashemi, S.J.

2009-01-01

The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, α-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > α-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

Dose-dependent platelet stimulation and inhibition induced by anti-PIA1 IgG

International Nuclear Information System (INIS)

Ryu, T.; Davis, J.M.; Schwartz, K.A.

1990-01-01

The PIA1 antibody produces several clinically distinct and severe thrombocytopenias. Investigations have demonstrated divergent effects on platelet function; prior reports demonstrated inhibition, while a conflicting publication showed platelet activation. We have resolved this conflict using anti-PIA1 IgG produced by a patient with posttransfusion purpura. Relatively low concentrations stimulated platelet aggregation and release of adenosine triphosphate (ATP) whereas high concentrations inhibited platelet function, producing a thrombasthenia-like state. The number of molecules of platelet-associated IgG necessary to initiate aggregation and ATP release (2,086 +/- 556) or produce maximum aggregation (23,420 +/- 3,706) or complete inhibition (63,582 +/- 2654) were measured with a quantitative radiometric assay for bound anti-PIA1. Preincubation of platelets with high concentrations of PIA1 antibody inhibited platelet aggregation with 10 mumol/L adenosine diphosphate and blocked 125I-labeled fibrinogen platelet binding. Platelet activation with nonfibrinogen dependent agonist, 1 U/ml thrombin, was not inhibited by this high concentration of PIA1 IgG. In conclusion, anti-PIAI IgG produces (1) stimulation of platelet aggregation and ATP release that is initiated with 2000 molecules IgG per platelet and is associated with an increase of 125I-fibrinogen binding; (2) conversely, inhibition of platelet aggregation is observed with maximum antibody binding, 63,000 molecules IgG per platelet, and is mediated via a blockade of fibrinogen binding

Overview of Maximum Power Point Tracking Techniques for Photovoltaic Energy Production Systems

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2015-01-01

A substantial growth of the installed photovoltaic systems capacity has occurred around the world during the last decade, thus enhancing the availability of electric energy in an environmentally friendly way. The maximum power point tracking technique enables maximization of the energy production...... of photovoltaic sources during stochastically varying solar irradiation and ambient temperature conditions. Thus, the overall efficiency of the photovoltaic energy production system is increased. Numerous techniques have been presented during the last decade for implementing the maximum power point tracking...... process in a photovoltaic system. This article provides an overview of the operating principles of these techniques, which are suited for either uniform or non-uniform solar irradiation conditions. The operational characteristics and implementation requirements of these maximum power point tracking...

Gain control through divisive inhibition prevents abrupt transition to chaos in a neural mass model

Science.gov (United States)

Papasavvas, Christoforos A.; Wang, Yujiang; Trevelyan, Andrew J.; Kaiser, Marcus

2016-01-01

Experimental results suggest that there are two distinct mechanisms of inhibition in cortical neuronal networks: subtractive and divisive inhibition. They modulate the input-output function of their target neurons either by increasing the input that is needed to reach maximum output or by reducing the gain and the value of maximum output itself, respectively. However, the role of these mechanisms on the dynamics of the network is poorly understood. We introduce a novel population model and numerically investigate the influence of divisive inhibition on network dynamics. Specifically, we focus on the transitions from a state of regular oscillations to a state of chaotic dynamics via period-doubling bifurcations. The model with divisive inhibition exhibits a universal transition rate to chaos (Feigenbaum behavior). In contrast, in an equivalent model without divisive inhibition, transition rates to chaos are not bounded by the universal constant (non-Feigenbaum behavior). This non-Feigenbaum behavior, when only subtractive inhibition is present, is linked to the interaction of bifurcation curves in the parameter space. Indeed, searching the parameter space showed that such interactions are impossible when divisive inhibition is included. Therefore, divisive inhibition prevents non-Feigenbaum behavior and, consequently, any abrupt transition to chaos. The results suggest that the divisive inhibition in neuronal networks could play a crucial role in keeping the states of order and chaos well separated and in preventing the onset of pathological neural dynamics. PMID:26465514

Inhibition of white light of 86Rb+ absorption in the root apex of corn

International Nuclear Information System (INIS)

McKendree, W.L.; Smith, R.C.

1990-01-01

Measurements of cell lengths made at 0.5 millimeter intervals in median longitudinal sections of the primary roots of corn (Zea mays) were used to construct a growth curve. The region 1.5 to 4.0 millimeters from the apex contained the largest number of elongating cells. Absorption of 86 Rb + was measured using intact, dark-grown corn seedlings. Following uptake and exchange, the terminal 8.0 millimeters of each root was cut into four 2.0 millimeter segments. Maximum 86 Rb + uptake occurred in the region from 0.0 to 4.0 millimeter from the root tip. Washing the intact primary root in fresh 2.0 millimolar CaSO 4 for 2 hours prior to uptake augmented the rate of 86 Rb + uptake in all regions. Illumination with white light during washing caused a reduction of 86 Rb + uptake as compared with controls washing in darkness, and the region of greatest light response was the region of elongation. Removal of the coleoptile prior to washing did not prevent the light inhibition of subsequent 86 Rb + uptake. Removal of the root cap prior to washing in light partially reversed the light-induced inhibition of the washing response

Growth inhibition of Listeria monocytogenes by a nonbacteriocinogenic Carnobacterium piscicola

DEFF Research Database (Denmark)

Nilsson, Lilian; Bech Hansen, T.; Garrido, P.

2005-01-01

Aims: This study elucidates the mechanisms by which a nonbacteriocinogenic Carnobacterium piscicola inhibits growth of Listeria monocytogenes. Methods and Results: Listeria monocytogenes was exposed to live cultures of a bacteriocin-negative variant of C. piscicola A9b in co-culture, in a diffusion...... chamber system, and to a cell-free supernatant. Suppression of maximum cell density (0-3.5 log units) of L. monocytogenes was proportional to initial levels of C. pisciola (10(3)-10(7) CFU ml(-1)). Cell-to-cell contact was not required to cause inhibition. The cell-free C. piscicola supernatant caused...... a decrease in L. monocytogenes maximum cell density, which was abolished by glucose addition but not by amino acid, vitamin or mineral addition. The fermentate also gave rise to a longer lag phase and a reduction in growth rate. These effects were independent of glucose and may have been caused by acetate...

ACAT inhibition and progression of carotid atherosclerosis in patients with familial hypercholesterolemia: the CAPTIVATE randomized trial.

Science.gov (United States)

Meuwese, Marijn C; de Groot, Eric; Duivenvoorden, Raphaël; Trip, Mieke D; Ose, Leiv; Maritz, Frans J; Basart, Dick C G; Kastelein, John J P; Habib, Rafik; Davidson, Michael H; Zwinderman, Aeilko H; Schwocho, Lee R; Stein, Evan A

2009-03-18

Inhibition of acyl coenzyme A:cholesterol acyltransferase (ACAT), an intracellular enzyme involved in cholesterol accumulation, with pactimibe was developed to assist in the prevention of cardiovascular disease. To evaluate the efficacy and safety of pactimibe in inhibition of atherosclerosis. A prospective, randomized, stratified, double-blind, placebo-controlled study (Carotid Atherosclerosis Progression Trial Investigating Vascular ACAT Inhibition Treatment Effects [CAPTIVATE]) of 892 patients heterozygous for familial hypercholesterolemia conducted at 40 lipid clinics in the United States, Canada, Europe, South Africa, and Israel between February 1, 2004, and December 31, 2005. Study was terminated on October 26, 2005. Participants received either 100 mg/d of pactimibe (n = 443) or matching placebo (n = 438), in addition to standard lipid-lowering therapy. Carotid atherosclerosis, assessed by ultrasound carotid intima-media thickness (CIMT), at baseline, 12, 18, and 24 months. Maximum CIMT was the primary end point and mean CIMT the secondary end point. Because pactimibe failed to show efficacy in the intravascular coronary ultrasound ACTIVATE study, the CAPTIVATE study was terminated prematurely after a follow-up of 15 months. After 6 months of treatment with pactimibe, low-density lipoprotein cholesterol increased by 7.3% (SD, 23%) compared with 1.4% (SD, 28%) in the placebo group (P = .001). The carotid ultrasonographic scans of the 716 patients with at least 2 scans and obtained at least 40 weeks apart were analyzed. Maximum CIMT measurements did not show a pactimibe treatment effect (difference, 0.004 mm; 95% confidence interval [CI], -0.023 to 0.015 mm; P = .64); however, the less variable mean CIMT measurement revealed an increase of 0.014 mm (95% CI, -0.027 to 0.000 mm; P = .04) in patients administered pactimibe vs placebo. Major cardiovascular events (cardiovascular death, myocardial infarction, and stroke) occurred more often in patients administered

Maximum permissible dose

International Nuclear Information System (INIS)

Anon.

1979-01-01

This chapter presents a historic overview of the establishment of radiation guidelines by various national and international agencies. The use of maximum permissible dose and maximum permissible body burden limits to derive working standards is discussed

Behavioral predictors of alcohol drinking in a neurodevelopmental rat model of schizophrenia and co-occurring alcohol use disorder.

Science.gov (United States)

Khokhar, Jibran Y; Todd, Travis P

2018-04-01

Alcohol use disorder commonly occurs in patients with schizophrenia and contributes greatly to its morbidity. Unfortunately, the neural and behavioral underpinnings of alcohol drinking in these patients are not well understood. In order to begin to understand the cognitive and reward-related changes that may contribute to alcohol drinking, this study was designed to address: 1) latent inhibition; 2) conditioning; and 3) extinction of autoshaping in a neurodevelopmental rat model with relevance to co-occurring schizophrenia and alcohol use disorders, the neonatal ventral hippocampal lesioned (NVHL) rat. NVHL lesions (or sham surgeries) were performed on post-natal day 7 (PND7) and animals were given brief exposure to alcohol during adolescent (PND 28-42). Latent inhibition of autoshaping, conditioning and extinction were assessed between PND 72-90. On PND90 animals were given alcohol again and allowed to establish stable drinking. Latent inhibition of autoshaping was found to be prolonged in the NVHL rats; the NVHL rats pre-exposed to the lever stimulus were slower to acquire autoshaping than sham pre-exposed rats. NVHL rats that were not pre-exposed to the lever stimulus did not differ during conditioning, but were slower to extinguish conditioned responding compared to sham controls. Finally, the NVHL rats from both groups drank significantly more alcohol than sham rats, and the extent of latent inhibition predicted future alcohol intake in the pre-exposed animals. These findings suggest that the latent inhibition of autoshaping procedure can be used to model cognitive- and reward-related dysfunctions in schizophrenia, and these dysfunctions may contribute to the development of co-occurring alcohol use. Copyright © 2017 Elsevier B.V. All rights reserved.

Is forgetting caused by inhibition?

NARCIS (Netherlands)

Raaijmakers, J.G.W.; Jakab, E.

2013-01-01

A well-known finding in memory research is the forgetting effect that occurs because of practicing some Item A on the recall of a related Item B. The traditional explanation for such interference effects is based on the notion of competition. According to the inhibition theory of forgetting,

Urease from Staphylococcus saprophyticus. Some properties and inhibition by metal ions

Energy Technology Data Exchange (ETDEWEB)

Glemzha, A A; Kovzan, V B; Yuodval' kite, D Yu

1984-12-01

Data concerning the molecular weight, the dependence of the enzymic rate of the pH and the concentration of the substrate, and the effect of metal ions on urease activity are presented and discussed. Precipitation with ethanol was used to isolate a urease preparation with a specific activity of 250-300 units/mg of protein from Staphylococcus saprophyticus cells. The molecular weight of the enzyme, determined by gel filtration on a Sephadex G-200 column is 250,000. Maximum activity of St. saprophyticus urease occurred at pH 6.8-7.0; the K/sub m/ value, at 30/sup 0/C (pH 6.8) equalled 7.36 x 10/sup -3/ M, V/sub max/ is 1.5 ..mu..mol NH/sub 3//min. The enzyme was reversibly inhibited by heavy metal ions. The sequence of inhibiting effect of the ions studied is: Ag/sup +/>Ni/sup 2 +/>Cd/sup 2 +/>Co/sup 2 +/>Hg/sup 2 +/>Cu/sup 2 +/>Zn/sup 2 +/>Pb/sup 2 +/ and pK of groups of the active center equal 5.0-5.25 and 8.25 and are near in value to those of the imidazole ring of histidine (0.5-7.0) and the Sh-group of cysteine (8.3-8.6). 19 references, 4 figures.

Putting retrieval-induced forgetting in context: an inhibition-free, context-based account.

Science.gov (United States)

Jonker, Tanya R; Seli, Paul; MacLeod, Colin M

2013-10-01

We present a new theoretical account of retrieval-induced forgetting (RIF) together with new experimental evidence that fits this account and challenges the dominant inhibition account. RIF occurs when the retrieval of some material from memory produces later forgetting of related material. The inhibition account asserts that RIF is the result of an inhibition mechanism that acts during retrieval to suppress the representations of interfering competitors. This inhibition is enduring, such that the suppressed material is difficult to access on a later test and is, therefore, recalled more poorly than baseline material. Although the inhibition account is widely accepted, a growing body of research challenges its fundamental assumptions. Our alternative account of RIF instead emphasizes the role of context in remembering. According to this context account, both of 2 tenets must be met for RIF to occur: (a) A context change must occur between study and subsequent retrieval practice, and (b) the retrieval practice context must be the active context during the final test when testing practiced categories. The results of 3 experiments, which directly test the divergent predictions of the 2 accounts, support the context account but cannot be explained by the inhibition account. In an extensive discussion, we survey the literature on RIF and apply our context account to the key findings, demonstrating the explanatory power of context. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Conditions for maximum isolation of stable condensate during separation in gas-condensate systems

Energy Technology Data Exchange (ETDEWEB)

Trivus, N.A.; Belkina, N.A.

1969-02-01

A thermodynamic analysis is made of the gas-liquid separation process in order to determine the relationship between conditions of maximum stable condensate separation and physico-chemical nature and composition of condensate. The analysis was made by considering the multicomponent gas-condensate fluid produced from Zyrya field as a ternary system, composed of methane, an intermediate component (propane and butane) and a heavy residue, C/sub 6+/. Composition of 5 ternary systems was calculated for a wide variation in separator conditions. At each separator pressure there is maximum condensate production at a certain temperature. This occurs because solubility of condensate components changes with temperature. Results of all calculations are shown graphically. The graphs show conditions of maximum stable condensate separation.

Thiol dependent NF-κB suppression and inhibition of T-cell mediated adaptive immune responses by a naturally occurring steroidal lactone Withaferin A

Energy Technology Data Exchange (ETDEWEB)

Gambhir, Lokesh; Checker, Rahul; Sharma, Deepak; Thoh, M. [Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai (India); Patil, Anand [Advanced Centre for Treatment Research and Education in Cancer, Kharghar, Navi Mumbai (India); Degani, M. [Institute of Chemical Technology, Matunga, Mumbai (India); Gota, Vikram [Advanced Centre for Treatment Research and Education in Cancer, Kharghar, Navi Mumbai (India); Sandur, Santosh K., E-mail: sskumar@barc.gov.in [Radiation Biology & Health Sciences Division, Bio-science Group, Bhabha Atomic Research Centre, Mumbai (India)

2015-12-01

Withaferin A (WA), a steroidal lactone isolated from ayurvedic medicinal plant Withania somnifera, was shown to inhibit tumor growth by inducing oxidative stress and suppressing NF-κB pathway. However, its effect on T-cell mediated adaptive immune responses and the underlying mechanism has not been investigated. Since both T-cell responses and NF-κB pathway are known to be redox sensitive, the present study was undertaken to elucidate the effect of WA on adaptive immune responses in vitro and in vivo. WA inhibited mitogen induced T-cell and B-cell proliferation in vitro without inducing any cell death. It inhibited upregulation of T-cell (CD25, CD69, CD71 and CD54) and B-cell (CD80, CD86 and MHC-II) activation markers and secretion of Th1 and Th2 cytokines. WA induced oxidative stress by increasing the basal ROS levels and the immunosuppressive effects of WA were abrogated only by thiol anti-oxidants. The redox modulatory effects of WA in T-cells were attributed to its ability to directly interact with free thiols. WA inhibited NF-κB nuclear translocation in lymphocytes and prevented the direct binding of nuclear NF-κB to its consensus sequence. MALDI-TOF analysis using a synthetic NF-κB-p50 peptide containing Cys-62 residue suggested that WA can modify the cysteine residue of NF-κB. The pharmacokinetic studies for WA were also carried out and in vivo efficacy of WA was studied using mouse model of Graft-versus-host disease. In conclusion, WA is a potent inhibitor of T-cell responses and acts via a novel thiol dependent mechanism and inhibition of NF-κB pathway. - Highlights:: • Withaferin A (WA) inhibited T-cell and B-cell mediated immune responses. • WA increased basal ROS levels in lymphocytes. • WA directly interacted with GSH as studied using spectrophotometry and HPLC. • WA inhibited NF-κB nuclear translocation and binding of nuclear NF-κB to DNA. • WA inhibited induction of the graft-versus-host disease in mice.

Chirality Influence of Zaltoprofen Towards UDP-Glucuronosyltransferases (UGTs) Inhibition Potential.

Science.gov (United States)

Jia, Lin; Hu, Cuimin; Wang, Haina; Liu, Yongzhe; Liu, Xin; Zhang, Yan-Yan; Li, Wei; Wang, Li-Xuan; Cao, Yun-Feng; Fang, Zhong-Ze

2015-06-01

Zaltoprofen (ZLT) is a nonsteroidal antiinflammation drug, and has been clinically employed to treat rheumatoid arthritis, osteoarthritis, and other chronic inflammatory pain conditions. The present study aims to investigate the chirality influence of zaltoprofen towards the inhibition potential towards UDP-glucuronosyltransferases (UGTs) isoforms. In vitro a recombinant UGT isoforms-catalyzed 4-methylumbelliferone (4-MU) glucuronidation incubation system was employed to investigate the inhibition of (R)-zaltoprofen and (S)-zaltoprofen towards UGT isoforms. The inhibition difference capability was observed for the inhibition of (R)-zaltoprofen and (S)-zaltoprofen towards UGT1A8 and UGT2B7, but not for other tested UGT isoforms. (R)-zaltoprofen exhibited noncompetitive inhibition towards UGT1A8 and competitive inhibition towards UGT2B7. The inhibition kinetic parameters were calculated to be 35.3 μM and 19.2 μM for UGT1A8 and UGT2B7. (R)-zaltoprofen and (S)-zaltoprofen exhibited a different inhibition type towards UGT1A7. Based on the reported maximum plasma concentration of (R)-zaltoprofen in vivo, a high drug-drug interaction between (R)-zaltoprofen and the drugs mainly undergoing UGT1A7, UGT1A8, and UGT2B7-catalyzed glucuronidation was indicated. © 2015 Wiley Periodicals, Inc.

Corrosion Inhibition of Carbon Steel in HCl Solution by Some Plant Extracts

Directory of Open Access Journals (Sweden)

Ambrish Singh

2012-01-01

Full Text Available The strict environmental legislations and increasing ecological awareness among scientists have led to the development of “green” alternatives to mitigate corrosion. In the present work, literature on green corrosion inhibitors has been reviewed, and the salient features of our work on green corrosion inhibitors have been highlighted. Among the studied leaves, extract Andrographis paniculata showed better inhibition performance (98% than the other leaves extract. Strychnos nuxvomica showed better inhibition (98% than the other seed extracts. Moringa oleifera is reflected as a good corrosion inhibitor of mild steel in 1 M HCl with 98% inhibition efficiency among the studied fruits extract. Bacopa monnieri showed its maximum inhibition performance to be 95% at 600 ppm among the investigated stem extracts. All the reported plant extracts were found to inhibit the corrosion of mild steel in acid media.

Heightened Conflict in Cue-Target Translation Increases Backward Inhibition in Set Switching

Science.gov (United States)

Grange, James A.; Houghton, George

2010-01-01

Backward inhibition (BI) is a performance cost that occurs when an individual returns to a task after 1 (vs. more than 1) intervening trial, and it may reflect the inhibition of task-set components during switching. In 3 experiments, we support the theory that inhibition can target cue-based preparatory stages of a task. Participants performed a…

Locally formed dopamine inhibits Na sup + -K sup + -ATPase activity in rat renal cortical tubule cells

Energy Technology Data Exchange (ETDEWEB)

Seri, I.; Kone, B.C.; Gullans, S.R.; Aperia, A.; Brenner, B.M.; Ballermann, B.J. (Harvard Medical School, Boston, MA (USA) Karolinska Institute, Stockholm (Sweden))

1988-10-01

Dopamine, generated locally from L-dopa, inhibits Na{sup +}-K{sup +}-ATPase in permeabilized rat proximal tubules under maximum transport rate conditions for sodium. To determine whether locally formed dopamine inhibits Na{sup +}-K{sup +}-ATPase activity in intact cortical tubule cells we studied the effect of L-dopa on ouabain-sensitive oxygen consumption rate ({dot Q}o{sub 2}) and {sup 86}Rb uptake in renal cortical tubule cell suspensions. L-Dopa did not affect ouabain-insensitive {dot Q}o{sub 2} or mitochondrial respiration. However, L-dopa inhibited ouabain-sensitive {dot Q}o{sub 2} in a concentration-dependent manner, with half-maximal inhibition (K{sub 0.5}) of 5 {times} 10{sup {minus}7} M and a maximal inhibition of 14.1 {plus minus} 1.5% at 10{sup {minus}4}M. L-Dopa also blunted the nystatin-stimulated {dot Q}o{sub 2} in a concentration-dependent manner, indicating the L-dopa directly inhibits Na{sup +}-K{sup +}-ATPase activity and not sodium entry. Ouabain-sensitive {sup 86}Rb uptake was also inhibited by L-dopa. Carbidopa, an inhibitor of the conversion of L-dopa to dopamine, eliminated the effect of L-dopa on ouabain-sensitive {dot Q}o{sub 2} and {sup 86}Rb uptake, indicating that dopamine rather than L-dopa was the active agent. The finding that the L-dopa concentration-response curve was shifted to the left by one order of magnitude in the presence of nystatin suggests that the inhibitory effect is enhanced when the intracellular sodium concentration is increased. By studying the effect of L-dopa on ouabain-sensitive {dot Q}o{sub 2} at increasing extracellular sodium concentrations in the presence of nystatin, the authors demonstrated that the inhibitory effect of locally formed dopamine on the Na{sup +}-K{sup +}-ATPase is indeed dependent on the sodium available for the enzyme and occurs in an uncompetitive manner.

Measurement of the temperature of density maximum of water solutions using a convective flow technique

OpenAIRE

Cawley, M.F.; McGlynn, D.; Mooney, P.A.

2006-01-01

A technique is described which yields an accurate measurement of the temperature of density maximum of fluids which exhibit such anomalous behaviour. The method relies on the detection of changes in convective flow in a rectangular cavity containing the test fluid.The normal single-cell convection which occurs in the presence of a horizontal temperature gradient changes to a double cell configuration in the vicinity of the density maximum, and this transition manifests itself in changes in th...

Gas hydrate inhibition by perturbation of liquid water structure

Science.gov (United States)

Sa, Jeong-Hoon; Kwak, Gye-Hoon; Han, Kunwoo; Ahn, Docheon; Lee, Kun-Hong

2015-06-01

Natural gas hydrates are icy crystalline materials that contain hydrocarbons, which are the primary energy source for this civilization. The abundance of naturally occurring gas hydrates leads to a growing interest in exploitation. Despite their potential as energy resources and in industrial applications, there is insufficient understanding of hydrate kinetics, which hinders the utilization of these invaluable resources. Perturbation of liquid water structure by solutes has been proposed to be a key process in hydrate inhibition, but this hypothesis remains unproven. Here, we report the direct observation of the perturbation of the liquid water structure induced by amino acids using polarized Raman spectroscopy, and its influence on gas hydrate nucleation and growth kinetics. Amino acids with hydrophilic and/or electrically charged side chains disrupted the water structure and thus provided effective hydrate inhibition. The strong correlation between the extent of perturbation by amino acids and their inhibition performance constitutes convincing evidence for the perturbation inhibition mechanism. The present findings bring the practical applications of gas hydrates significantly closer, and provide a new perspective on the freezing and melting phenomena of naturally occurring gas hydrates.

A fusion-inhibiting peptide against Rift Valley fever virus inhibits multiple, diverse viruses.

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Jeffrey W Koehler

Full Text Available For enveloped viruses, fusion of the viral envelope with a cellular membrane is critical for a productive infection to occur. This fusion process is mediated by at least three classes of fusion proteins (Class I, II, and III based on the protein sequence and structure. For Rift Valley fever virus (RVFV, the glycoprotein Gc (Class II fusion protein mediates this fusion event following entry into the endocytic pathway, allowing the viral genome access to the cell cytoplasm. Here, we show that peptides analogous to the RVFV Gc stem region inhibited RVFV infectivity in cell culture by inhibiting the fusion process. Further, we show that infectivity can be inhibited for diverse, unrelated RNA viruses that have Class I (Ebola virus, Class II (Andes virus, or Class III (vesicular stomatitis virus fusion proteins using this single peptide. Our findings are consistent with an inhibition mechanism similar to that proposed for stem peptide fusion inhibitors of dengue virus in which the RVFV inhibitory peptide first binds to both the virion and cell membranes, allowing it to traffic with the virus into the endocytic pathway. Upon acidification and rearrangement of Gc, the peptide is then able to specifically bind to Gc and prevent fusion of the viral and endocytic membranes, thus inhibiting viral infection. These results could provide novel insights into conserved features among the three classes of viral fusion proteins and offer direction for the future development of broadly active fusion inhibitors.

Time-lapse cinematography of the capillary tube cell migration inhibition test.

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Bray, M A

1980-01-01

The kinetics of human and guinea pig cell migration inhibition have been studied using time-lapse cinematography of cells migrating from capillary tubes. Guinea pig and human cells exhibit markedly different kinetics in the absence of inhibitors. Specific antigen causes a dose-related inhibition of migration for up to 60 h using guinea pig cells and a peak of inhibition after 18 h using the human leucocyte system. The timing of measurement of maximum activity more critical for the latter test. The kinetics of lymphokine generation have been examined and the migration inhibitory activity of the plant mitogen (PHA), a Kurloff cell product and a continuous cell line supernatant have been compared with the inhibitory profiles of lymphokine preparations and specific antigen.

Conifers in cold environments synchronize maximum growth rate of tree-ring formation with day length.

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Rossi, Sergio; Deslauriers, Annie; Anfodillo, Tommaso; Morin, Hubert; Saracino, Antonio; Motta, Renzo; Borghetti, Marco

2006-01-01

Intra-annual radial growth rates and durations in trees are reported to differ greatly in relation to species, site and environmental conditions. However, very similar dynamics of cambial activity and wood formation are observed in temperate and boreal zones. Here, we compared weekly xylem cell production and variation in stem circumference in the main northern hemisphere conifer species (genera Picea, Pinus, Abies and Larix) from 1996 to 2003. Dynamics of radial growth were modeled with a Gompertz function, defining the upper asymptote (A), x-axis placement (beta) and rate of change (kappa). A strong linear relationship was found between the constants beta and kappa for both types of analysis. The slope of the linear regression, which corresponds to the time at which maximum growth rate occurred, appeared to converge towards the summer solstice. The maximum growth rate occurred around the time of maximum day length, and not during the warmest period of the year as previously suggested. The achievements of photoperiod could act as a growth constraint or a limit after which the rate of tree-ring formation tends to decrease, thus allowing plants to safely complete secondary cell wall lignification before winter.

The corrosion inhibition of aluminum and its copper alloys in 1.0 M H2SO4 solution using linear-sodium dodecyl benzene sulfonate as inhibitor

International Nuclear Information System (INIS)

Abd El Rehim, Sayed S.; Amin, Mohammed A.; Moussa, S.O.; Ellithy, Abdallah S.

2008-01-01

The corrosion inhibition of Al and its two copper alloys are the subject of tremendous technological importance due to the increased industrial applications of these materials. This paper reports the results of potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) measurements on the corrosion inhibition of Al (Al-2.5% Cu and Al-7.0% Cu) alloys in 1.0 M H 2 SO 4 solution carried out in different concentrations of linear-sodium dodecyl benzene sulfonate as an anionic surfactant (LAS) and temperature range from 10 to 60 deg. C. The data revealed that the inhibition efficiency increases with increasing surfactant concentration and time of immersion, and decreases with solution temperature. Energy dispersion X-ray (EDX) observations of the electrode surface confirmed the existence of LAS adsorbed film on the electrode surface. The surfactant acted mainly as cathodic inhibitor. Maximum inhibition efficiency of the surfactant is observed at concentration around its critical micelle concentration (CMC). The inhibition occurs through adsorption of the surfactant on the metal surface without modifying the mechanism of the corrosion process, which tested by UV-spectroscopy. The potential of zero charge (PZC) of aluminum and Al-7.0% Cu was studied by ac-impedance, and the mechanism of adsorption is discussed. The adsorption isotherm is described by Temkin adsorption isotherm. Thermodynamic functions for activation and adsorption process were determined

Cosmic shear measurement with maximum likelihood and maximum a posteriori inference

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Hall, Alex; Taylor, Andy

2017-06-01

We investigate the problem of noise bias in maximum likelihood and maximum a posteriori estimators for cosmic shear. We derive the leading and next-to-leading order biases and compute them in the context of galaxy ellipticity measurements, extending previous work on maximum likelihood inference for weak lensing. We show that a large part of the bias on these point estimators can be removed using information already contained in the likelihood when a galaxy model is specified, without the need for external calibration. We test these bias-corrected estimators on simulated galaxy images similar to those expected from planned space-based weak lensing surveys, with promising results. We find that the introduction of an intrinsic shape prior can help with mitigation of noise bias, such that the maximum a posteriori estimate can be made less biased than the maximum likelihood estimate. Second-order terms offer a check on the convergence of the estimators, but are largely subdominant. We show how biases propagate to shear estimates, demonstrating in our simple set-up that shear biases can be reduced by orders of magnitude and potentially to within the requirements of planned space-based surveys at mild signal-to-noise ratio. We find that second-order terms can exhibit significant cancellations at low signal-to-noise ratio when Gaussian noise is assumed, which has implications for inferring the performance of shear-measurement algorithms from simplified simulations. We discuss the viability of our point estimators as tools for lensing inference, arguing that they allow for the robust measurement of ellipticity and shear.

Growth inhibition of Listeria spp. on Camembert cheese by bacteria producing inhibitory substances.

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Sulzer, G; Busse, M

1991-12-01

Bacterial strains exhibiting antimicrobial activity towards other bacteria are quite common in nature. During the past few years several genera have been shown to exert inhibitory action against Listeria. spp. In the present work strains of Enterococcus, Lactobacillus and Lactococcus were tested for their influence on the development of Listeria spp. on Camembert cheese. Partial or complete inhibition of growth of Listeria spp. was observed using various inhibitory bacteria. Complete inhibition occurred when the inhibitory strain was used as a starter culture and there was a low level of contamination with Listeria spp. during the first stage of ripening. Very little inhibition occurred if the inhibitory strain was added together with the starter culture.

High Concentrations of Tranexamic Acid Inhibit Ionotropic Glutamate Receptors.

Science.gov (United States)

Lecker, Irene; Wang, Dian-Shi; Kaneshwaran, Kirusanthy; Mazer, C David; Orser, Beverley A

2017-07-01

The antifibrinolytic drug tranexamic acid is structurally similar to the amino acid glycine and may cause seizures and myoclonus by acting as a competitive antagonist of glycine receptors. Glycine is an obligatory co-agonist of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptors. Thus, it is plausible that tranexamic acid inhibits NMDA receptors by acting as a competitive antagonist at the glycine binding site. The aim of this study was to determine whether tranexamic acid inhibits NMDA receptors, as well as α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate subtypes of ionotropic glutamate receptors. Tranexamic acid modulation of NMDA, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, and kainate receptors was studied using whole cell voltage-clamp recordings of current from cultured mouse hippocampal neurons. Tranexamic acid rapidly and reversibly inhibited NMDA receptors (half maximal inhibitory concentration = 241 ± 45 mM, mean ± SD; 95% CI, 200 to 281; n = 5) and shifted the glycine concentration-response curve for NMDA-evoked current to the right. Tranexamic acid also inhibited α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (half maximal inhibitory concentration = 231 ± 91 mM; 95% CI, 148 to 314; n = 5 to 6) and kainate receptors (half maximal inhibitory concentration = 90 ± 24 mM; 95% CI, 68 to 112; n = 5). Tranexamic acid inhibits NMDA receptors likely by reducing the binding of the co-agonist glycine and also inhibits α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and kainate receptors. Receptor blockade occurs at high millimolar concentrations of tranexamic acid, similar to the concentrations that occur after topical application to peripheral tissues. Glutamate receptors in tissues including bone, heart, and nerves play various physiologic roles, and tranexamic acid inhibition of these receptors may contribute to adverse drug effects.

Maturation of cognitive control: delineating response inhibition and interference suppression.

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Christopher R Brydges

Full Text Available Cognitive control is integral to the ability to attend to a relevant task whilst suppressing distracting information or inhibiting prepotent responses. The current study examined the development of these two subprocesses by examining electrophysiological indices elicited during each process. Thirteen 18 year-old adults and thirteen children aged 8-11 years (mean=9.77 years completed a hybrid Go/Nogo flanker task while continuous EEG data were recorded. The N2 topography for both response inhibition and interference suppression changed with increasing age. The neural activation associated with response inhibition became increasingly frontally distributed with age, and showed decreases of both amplitude and peak latency from childhood to adulthood, possibly due to reduced cognitive demands and myelination respectively occurring during this period. Interestingly, a significant N2 effect was apparent in adults, but not observed in children during trials requiring interference suppression. This could be due to more diffuse activation in children, which would require smaller levels of activation over a larger region of the brain than is reported in adults. Overall, these results provide evidence of distinct maturational processes occurring throughout late childhood and adolescence, highlighting the separability of response inhibition and interference suppression.

Inhibition of Quorum Sensing-Controlled Virulence Factor Production in Pseudomonas aeruginosa PAO1 by Ayurveda Spice Clove (Syzygium Aromaticum Bud Extract

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Kok-Gan Chan

2012-03-01

Full Text Available Quorum sensing controls the virulence determinants in most proteobacteria. In this work, the hexane, chloroform and methanol extracts of an Ayurveda spice, namely clove (Syzygium aromaticum, shown anti-quorum sensing activity. Hexane and methanol extracts of clove inhibited the response of C. violaceum CV026 to exogenously supplied N‑hexanoylhomoserine lactone, in turn preventing violacein production. Chloroform and methanol extracts of clove significantly reduced bioluminescence production by E. coli [pSB1075] grown in the presence of N-(3-oxododecanoyl-L-homoserine lactone. We demonstrated that clove extract inhibited quorum sensing-regulated phenotypes in Pseudomonas aeruginosa PA01, including expression of lecA::lux (by hexane extract, swarming (maximum inhibition by methanol extract, pyocyanin (maximum inhibition by hexane extract. This study shows that the presence of natural compounds that exhibit anti-quorum sensing activity in the clove extracts may be useful as the lead of anti-infective drugs.

Preclinical characterization of naturally occurring polyketide cyclophilin inhibitors from the sanglifehrin family.

Science.gov (United States)

Gregory, Matthew A; Bobardt, Michael; Obeid, Susan; Chatterji, Udayan; Coates, Nigel J; Foster, Teresa; Gallay, Philippe; Leyssen, Pieter; Moss, Steven J; Neyts, Johan; Nur-e-Alam, Mohammad; Paeshuyse, Jan; Piraee, Mahmood; Suthar, Dipen; Warneck, Tony; Zhang, Ming-Qiang; Wilkinson, Barrie

2011-05-01

Cyclophilin inhibitors currently in clinical trials for hepatitis C virus (HCV) are all analogues of cyclosporine (CsA). Sanglifehrins are a group of naturally occurring cyclophilin binding polyketides that are structurally distinct from the cyclosporines and are produced by a microorganism amenable to biosynthetic engineering for lead optimization and large-scale production by fermentation. Preclinical characterization of the potential utility of this class of compounds for the treatment of HCV revealed that the natural sanglifehrins A to D are all more potent than CsA at disrupting formation of the NS5A-CypA, -CypB, and -CypD complexes and at inhibition of CypA, CypB, and CypD isomerase activity. In particular, sanglifehrin B (SfB) was 30- to 50-fold more potent at inhibiting the isomerase activity of all Cyps tested than CsA and was also shown to be a more potent inhibitor of the 1b subgenomic replicon (50% effective concentrations [EC50s] of 0.070 μM and 0.16 μM in Huh 5-2 and Huh 9-13 cells, respectively). Physicochemical and mouse pharmacokinetic analyses revealed low oral bioavailability (F5 h). These data demonstrate that naturally occurring sanglifehrins are suitable lead compounds for the development of novel analogues that are less immunosuppressive and that have improved metabolism and pharmacokinetic properties.

Hydraulic Limits on Maximum Plant Transpiration

Science.gov (United States)

Manzoni, S.; Vico, G.; Katul, G. G.; Palmroth, S.; Jackson, R. B.; Porporato, A. M.

2011-12-01

Photosynthesis occurs at the expense of water losses through transpiration. As a consequence of this basic carbon-water interaction at the leaf level, plant growth and ecosystem carbon exchanges are tightly coupled to transpiration. In this contribution, the hydraulic constraints that limit transpiration rates under well-watered conditions are examined across plant functional types and climates. The potential water flow through plants is proportional to both xylem hydraulic conductivity (which depends on plant carbon economy) and the difference in water potential between the soil and the atmosphere (the driving force that pulls water from the soil). Differently from previous works, we study how this potential flux changes with the amplitude of the driving force (i.e., we focus on xylem properties and not on stomatal regulation). Xylem hydraulic conductivity decreases as the driving force increases due to cavitation of the tissues. As a result of this negative feedback, more negative leaf (and xylem) water potentials would provide a stronger driving force for water transport, while at the same time limiting xylem hydraulic conductivity due to cavitation. Here, the leaf water potential value that allows an optimum balance between driving force and xylem conductivity is quantified, thus defining the maximum transpiration rate that can be sustained by the soil-to-leaf hydraulic system. To apply the proposed framework at the global scale, a novel database of xylem conductivity and cavitation vulnerability across plant types and biomes is developed. Conductivity and water potential at 50% cavitation are shown to be complementary (in particular between angiosperms and conifers), suggesting a tradeoff between transport efficiency and hydraulic safety. Plants from warmer and drier biomes tend to achieve larger maximum transpiration than plants growing in environments with lower atmospheric water demand. The predicted maximum transpiration and the corresponding leaf water

Maximum Acceleration Recording Circuit

Science.gov (United States)

Bozeman, Richard J., Jr.

1995-01-01

Coarsely digitized maximum levels recorded in blown fuses. Circuit feeds power to accelerometer and makes nonvolatile record of maximum level to which output of accelerometer rises during measurement interval. In comparison with inertia-type single-preset-trip-point mechanical maximum-acceleration-recording devices, circuit weighs less, occupies less space, and records accelerations within narrower bands of uncertainty. In comparison with prior electronic data-acquisition systems designed for same purpose, circuit simpler, less bulky, consumes less power, costs and analysis of data recorded in magnetic or electronic memory devices. Circuit used, for example, to record accelerations to which commodities subjected during transportation on trucks.

Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

International Nuclear Information System (INIS)

Xiao, Hong-Bo; Lu, Xiang-Yang; Sun, Zhi-Liang; Zhang, Heng-Bo

2011-01-01

Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE −/− ) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE −/− mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. -- Graphical abstract: Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis of ApoE −/− mice. Highlights: ► OPN–CD44 pathway plays a critical role in the development of atherosclerosis. ► We examine lesion area, OPN and CD44 changes after kaempferol treatment. ► Kaempferol treatment decreased atherosclerotic lesion area in ApoE −/− mice. ► Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE −/− mice. ► Kaempferol regulates OPN–CD44 pathway to inhibit the atherogenesis.

Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of apolipoprotein E deficient mice

Energy Technology Data Exchange (ETDEWEB)

Xiao, Hong-Bo, E-mail: xhbzhb@yahoo.com [College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128 (China); Lu, Xiang-Yang; Sun, Zhi-Liang [Hunan Agricultural University, Changsha 410128 (China); Zhang, Heng-Bo [Furong District Red Cross Hospital, Changsha 410126 (China)

2011-12-15

Recent studies show that osteopontin (OPN) and its receptor cluster of differentiation 44 (CD44) are two pro-inflammatory cytokines contributing to the development of atherosclerosis. The objective of this study was to explore the inhibitory effect of kaempferol, a naturally occurring flavonoid compound, on atherogenesis and the mechanisms involved. The experiments were performed in aorta and plasma from C57BL/6J control and apolipoprotein E-deficient (ApoE{sup -/-}) mice treated or not with kaempferol (50 or 100 mg/kg, intragastrically) for 4 weeks. Kaempferol treatment decreased atherosclerotic lesion area, improved endothelium-dependent vasorelaxation, and increased the maximal relaxation value concomitantly with decrease in the half-maximum effective concentration, plasma OPN level, aortic OPN expression, and aortic CD44 expression in ApoE{sup -/-} mice. In addition, treatment with kaempferol also significantly decreased reactive oxygen species production in mice aorta. The present results suggest that kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. -- Graphical abstract: Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis of ApoE{sup -/-} mice. Highlights: Black-Right-Pointing-Pointer OPN-CD44 pathway plays a critical role in the development of atherosclerosis. Black-Right-Pointing-Pointer We examine lesion area, OPN and CD44 changes after kaempferol treatment. Black-Right-Pointing-Pointer Kaempferol treatment decreased atherosclerotic lesion area in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol treatment decreased aortic OPN and CD44 expressions in ApoE{sup -/-} mice. Black-Right-Pointing-Pointer Kaempferol regulates OPN-CD44 pathway to inhibit the atherogenesis.

Neutron spectra unfolding with maximum entropy and maximum likelihood

International Nuclear Information System (INIS)

Itoh, Shikoh; Tsunoda, Toshiharu

1989-01-01

A new unfolding theory has been established on the basis of the maximum entropy principle and the maximum likelihood method. This theory correctly embodies the Poisson statistics of neutron detection, and always brings a positive solution over the whole energy range. Moreover, the theory unifies both problems of overdetermined and of underdetermined. For the latter, the ambiguity in assigning a prior probability, i.e. the initial guess in the Bayesian sense, has become extinct by virtue of the principle. An approximate expression of the covariance matrix for the resultant spectra is also presented. An efficient algorithm to solve the nonlinear system, which appears in the present study, has been established. Results of computer simulation showed the effectiveness of the present theory. (author)

Maximum Power from a Solar Panel

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Michael Miller

2010-01-01

Full Text Available Solar energy has become a promising alternative to conventional fossil fuel sources. Solar panels are used to collect solar radiation and convert it into electricity. One of the techniques used to maximize the effectiveness of this energy alternative is to maximize the power output of the solar collector. In this project the maximum power is calculated by determining the voltage and the current of maximum power. These quantities are determined by finding the maximum value for the equation for power using differentiation. After the maximum values are found for each time of day, each individual quantity, voltage of maximum power, current of maximum power, and maximum power is plotted as a function of the time of day.

Determination of the maximum inhibitory dilution of cetylpyridinium chloride-based mouthwashes against staphylococcus aureus: an in vitro study

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Evandro Watanabe

2008-08-01

Full Text Available The aim of this in vitro study was to determine the maximum inhibitory dilution (MID of four cetylpyridinium chloride (CPC-based mouthwashes: CPC+Propolis, CPC+Malva, CPC+Eucaliptol+Juá+Romã+Propolis (Natural Honey® and CPC (Cepacol®, against 28 Staphylococcus aureus field strains, using the agar dilution method. Decimal dilutions ranging from 1/10 to 1/655,360 were prepared and added to Mueller Hinton Agar. Strains were inoculated using Steers multipoint inoculator. The inocula were seeded onto the surface of the culture medium in Petri dishes containing different dilutions of the mouthwashes. The dishes were incubated at 37ºC for 24 h. For readings, the MID was considered as the maximum dilution of mouthwash still capable of inhibiting microbial growth. The obtained data showed that CPC+Propolis had antimicrobial activity against 27 strains at 1/320 dilution and against all 28 strains at 1/160 dilution, CPC+Malva inhibited the growth of all 28 strains at 1/320 dilution, CPC+Eucaliptol+Juá+Romã+Propolis inhibited the growth of 2 strains at 1/640 dilution and all 28 strains at 1/320 dilution, and Cepacol® showed antimicrobial activity against 3 strains at 1/320 dilution and against all 28 strains at 1/160 dilution. Data were submitted to Kruskal-Wallis test, showing that the MID of Cepacol® was lower than that determined for the other products (p<0.05. In conclusion, CPC-mouthwashes showed antimicrobial activity against S. aureus and the addition of other substances to CPC improved its antimicrobial effect.

Structure–inhibition relationship of ginsenosides towards UDP-glucuronosyltransferases (UGTs)

International Nuclear Information System (INIS)

Fang, Zhong-Ze; Cao, Yun-Feng; Hu, Cui-Min; Hong, Mo; Sun, Xiao-Yu; Ge, Guang-Bo; Liu, Yong; Zhang, Yan-Yan; Yang, Ling; Sun, Hong-Zhi

2013-01-01

The wide utilization of ginseng provides the high risk of herb–drug interaction (HDI) with many clinical drugs. The inhibition of ginsenosides towards drug-metabolizing enzymes (DMEs) has been regarded as an important reason for herb–drug interaction (HDI). Compared with the deep studies on the ginsenosides' inhibition towards cytochrome P450 (CYP), the inhibition of ginsenosides towards the important phase II enzymes UDP-glucuronosyltransferases (UGTs) remains to be unclear. The present study aims to evaluate the inhibition behavior of ginsenosides towards important UGT isoforms located in the liver and intestine using in vitro methods. The recombinant UGT isoform-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed as in vitro probe reaction. The results showed that structure-dependent inhibition existed for the inhibition of ginsenosides towards UGT isoforms. To clarify the possibility of in vivo herb–drug interaction induced by this kind of inhibition, the ginsenoside Rg 3 was selected as an example, and the inhibition kinetic type and parameters (K i ) were determined. Rg 3 competitively inhibited UGT1A7, 2B7 and 2B15-catalyzed 4-MU glucuronidation reaction, and exerted noncompetitive inhibition towards UGT1A8-catalyzed 4-MU glucuronidation. The inhibition parameters (K i values) were calculated to be 22.6, 7.9, 1.9, and 2.0 μM for UGT1A7, 1A8, 2B7 and 2B15. Using human maximum plasma concentration of Rg 3 (400 ng/ml (0.5 μM)) after intramuscular injection of 60 mg Rg 3 , the area under the plasma concentration-time curve (AUC) was extrapolated to increase by 2.2%, 6.3%, 26.3%, and 25% for the co-administered drugs completely undergoing the metabolism catalyzed by UGT1A7, 1A8, 2B7 and 2B15, respectively. All these results indicated that the ginsenosides' inhibition towards UGT isoforms might be an important reason for ginseng–drug interaction. - Highlights: ► Structure-dependent inhibition of ginsenoside towards UDP

Structure–inhibition relationship of ginsenosides towards UDP-glucuronosyltransferases (UGTs)

Energy Technology Data Exchange (ETDEWEB)

Fang, Zhong-Ze [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Cao, Yun-Feng [Key Laboratory of Contraceptives and Devices Research(NPFPC),Shanghai Engineer and Technology Research Center of Reproductive Health Drug and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai 200032 (China); Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Hu, Cui-Min [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892 (United States); Hong, Mo; Sun, Xiao-Yu [Joint Center for Translational Medicine, Dalian Institute of Chemical Physics Chinese Academy of Sciences and The first Affiliated Hospital of Liaoning Medical University, No.457, Zhongshan Road, Dalian 116023 (China); Ge, Guang-Bo; Liu, Yong; Zhang, Yan-Yan; Yang, Ling [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Dalian (China); Sun, Hong-Zhi, E-mail: zzfang228@gmail.com [The First Affiliated Hospital of Liaoning Medical University, Jinzhou 121001 (China)

2013-03-01

The wide utilization of ginseng provides the high risk of herb–drug interaction (HDI) with many clinical drugs. The inhibition of ginsenosides towards drug-metabolizing enzymes (DMEs) has been regarded as an important reason for herb–drug interaction (HDI). Compared with the deep studies on the ginsenosides' inhibition towards cytochrome P450 (CYP), the inhibition of ginsenosides towards the important phase II enzymes UDP-glucuronosyltransferases (UGTs) remains to be unclear. The present study aims to evaluate the inhibition behavior of ginsenosides towards important UGT isoforms located in the liver and intestine using in vitro methods. The recombinant UGT isoform-catalyzed 4-methylumbelliferone (4-MU) glucuronidation reaction was employed as in vitro probe reaction. The results showed that structure-dependent inhibition existed for the inhibition of ginsenosides towards UGT isoforms. To clarify the possibility of in vivo herb–drug interaction induced by this kind of inhibition, the ginsenoside Rg{sub 3} was selected as an example, and the inhibition kinetic type and parameters (K{sub i}) were determined. Rg{sub 3} competitively inhibited UGT1A7, 2B7 and 2B15-catalyzed 4-MU glucuronidation reaction, and exerted noncompetitive inhibition towards UGT1A8-catalyzed 4-MU glucuronidation. The inhibition parameters (K{sub i} values) were calculated to be 22.6, 7.9, 1.9, and 2.0 μM for UGT1A7, 1A8, 2B7 and 2B15. Using human maximum plasma concentration of Rg{sub 3} (400 ng/ml (0.5 μM)) after intramuscular injection of 60 mg Rg{sub 3}, the area under the plasma concentration-time curve (AUC) was extrapolated to increase by 2.2%, 6.3%, 26.3%, and 25% for the co-administered drugs completely undergoing the metabolism catalyzed by UGT1A7, 1A8, 2B7 and 2B15, respectively. All these results indicated that the ginsenosides' inhibition towards UGT isoforms might be an important reason for ginseng–drug interaction. - Highlights: ► Structure

The maximum entropy method of moments and Bayesian probability theory

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Bretthorst, G. Larry

2013-08-01

The problem of density estimation occurs in many disciplines. For example, in MRI it is often necessary to classify the types of tissues in an image. To perform this classification one must first identify the characteristics of the tissues to be classified. These characteristics might be the intensity of a T1 weighted image and in MRI many other types of characteristic weightings (classifiers) may be generated. In a given tissue type there is no single intensity that characterizes the tissue, rather there is a distribution of intensities. Often this distributions can be characterized by a Gaussian, but just as often it is much more complicated. Either way, estimating the distribution of intensities is an inference problem. In the case of a Gaussian distribution, one must estimate the mean and standard deviation. However, in the Non-Gaussian case the shape of the density function itself must be inferred. Three common techniques for estimating density functions are binned histograms [1, 2], kernel density estimation [3, 4], and the maximum entropy method of moments [5, 6]. In the introduction, the maximum entropy method of moments will be reviewed. Some of its problems and conditions under which it fails will be discussed. Then in later sections, the functional form of the maximum entropy method of moments probability distribution will be incorporated into Bayesian probability theory. It will be shown that Bayesian probability theory solves all of the problems with the maximum entropy method of moments. One gets posterior probabilities for the Lagrange multipliers, and, finally, one can put error bars on the resulting estimated density function.

Maximum allowable heat flux for a submerged horizontal tube bundle

International Nuclear Information System (INIS)

McEligot, D.M.

1995-01-01

For application to industrial heating of large pools by immersed heat exchangers, the socalled maximum allowable (or open-quotes criticalclose quotes) heat flux is studied for unconfined tube bundles aligned horizontally in a pool without forced flow. In general, we are considering boiling after the pool reaches its saturation temperature rather than sub-cooled pool boiling which should occur during early stages of transient operation. A combination of literature review and simple approximate analysis has been used. To date our main conclusion is that estimates of q inch chf are highly uncertain for this configuration

Illustrating Enzyme Inhibition Using Gibbs Energy Profiles

Science.gov (United States)

Bearne, Stephen L.

2012-01-01

Gibbs energy profiles have great utility as teaching and learning tools because they present students with a visual representation of the energy changes that occur during enzyme catalysis. Unfortunately, most textbooks divorce discussions of traditional kinetic topics, such as enzyme inhibition, from discussions of these same topics in terms of…

Prediction of transient maximum heat flux based on a simple liquid layer evaporation model

International Nuclear Information System (INIS)

Serizawa, A.; Kataoka, I.

1981-01-01

A model of liquid layer evaporation with considerable supply of liquid has been formulated to predict burnout characteristics (maximum heat flux, life, etc.) during an increase of the power. The analytical description of the model is built upon the visual and photographic observations of the boiling configuration at near peak heat flux reported by other investigators. The prediction compares very favourably with water data presently available. It is suggested from the work reported here that the maximum heat flux occurs because of a balance between the consumption of the liquid film on the heated surface and the supply of liquid. Thickness of the liquid film is also very important. (author)

Chlorpromazine inhibits tumour necrosis factor synthesis and cytotoxicity in vitro.

Science.gov (United States)

Zinetti, M; Galli, G; Demitri, M T; Fantuzzi, G; Minto, M; Ghezzi, P; Alzani, R; Cozzi, E; Fratelli, M

1995-11-01

Chlorpromazine (CPZ) has been previously shown to protect against endotoxin [lipopolysaccharide (LPS)] lethality and inhibit the release of tumour necrosis factor in vivo. We investigated at the cellular level whether this was due to direct inhibition of tumour necrosis factor-alpha (TNF-alpha) synthesis, using LPS-stimulated THP-1 human monocytic leukemia cells. We also studied the effect of CPZ on human TNF-alpha action by assessing TNF-alpha cytotoxicity on mouse fibrosarcoma L929 cells. CPZ (1-100 microM) inhibited TNF-alpha production in THP-1 cells in a dose dependent manner by a maximum of 80%. This effect was comparable to that of two well-known inhibitory drugs, dexamethasone and cyclicAMP. Inhibition was also evident at the mRNA level. On the other hand CPZ (10-25 microM) also inhibited TNF-alpha activity: in fact it reduced the cytotoxicity of TNF-alpha on L929 cells (EC50 was increased four times) and could provide protection even as a post-treatment. CPZ inhibited TNF-induced apoptosis in L929 cells, as detected by analysis of nuclear morphology. However, since we showed that apoptosis was very limited, and was not the main mode of cell death in our conditions, this could not explain the overall protection. Since CPZ did not interfere with either the oligomerization state of TNF-alpha or its receptor binding, our data suggest that it reduced cytotoxicity by inhibiting some steps in the TNF-alpha signalling pathways.

Regulation of spatial selectivity by crossover inhibition.

Science.gov (United States)

Cafaro, Jon; Rieke, Fred

2013-04-10

Signals throughout the nervous system diverge into parallel excitatory and inhibitory pathways that later converge on downstream neurons to control their spike output. Converging excitatory and inhibitory synaptic inputs can exhibit a variety of temporal relationships. A common motif is feedforward inhibition, in which an increase (decrease) in excitatory input precedes a corresponding increase (decrease) in inhibitory input. The delay of inhibitory input relative to excitatory input originates from an extra synapse in the circuit shaping inhibitory input. Another common motif is push-pull or "crossover" inhibition, in which increases (decreases) in excitatory input occur together with decreases (increases) in inhibitory input. Primate On midget ganglion cells receive primarily feedforward inhibition and On parasol cells receive primarily crossover inhibition; this difference provides an opportunity to study how each motif shapes the light responses of cell types that play a key role in visual perception. For full-field stimuli, feedforward inhibition abbreviated and attenuated responses of On midget cells, while crossover inhibition, though plentiful, had surprisingly little impact on the responses of On parasol cells. Spatially structured stimuli, however, could cause excitatory and inhibitory inputs to On parasol cells to increase together, adopting a temporal relation very much like that for feedforward inhibition. In this case, inhibitory inputs substantially abbreviated a cell's spike output. Thus inhibitory input shapes the temporal stimulus selectivity of both midget and parasol ganglion cells, but its impact on responses of parasol cells depends strongly on the spatial structure of the light inputs.

Sickle erythrocytes inhibit human endothelial cell DNA synthesis

International Nuclear Information System (INIS)

Weinstein, R.; Zhou, M.A.; Bartlett-Pandite, A.; Wenc, K.

1990-01-01

Patients with sickle cell anemia experience severe vascular occlusive phenomena including acute pain crisis and cerebral infarction. Obstruction occurs at both the microvascular and the arterial level, and the clinical presentation of vascular events is heterogeneous, suggesting a complex etiology. Interaction between sickle erythrocytes and the endothelium may contribute to vascular occlusion due to alteration of endothelial function. To investigate this hypothesis, human vascular endothelial cells were overlaid with sickle or normal erythrocytes and stimulated to synthesize DNA. The erythrocytes were sedimented onto replicate monolayers by centrifugation for 10 minutes at 17 g to insure contact with the endothelial cells. Incorporation of 3H-thymidine into endothelial cell DNA was markedly inhibited during contact with sickle erythrocytes. This inhibitory effect was enhanced more than twofold when autologous sickle plasma was present during endothelial cell labeling. Normal erythrocytes, with or without autologous plasma, had a modest effect on endothelial cell DNA synthesis. When sickle erythrocytes in autologous sickle plasma were applied to endothelial monolayers for 1 minute, 10 minutes, or 1 hour and then removed, subsequent DNA synthesis by the endothelial cells was inhibited by 30% to 40%. Although adherence of sickle erythrocytes to the endothelial monolayers was observed under these experimental conditions, the effect of sickle erythrocytes on endothelial DNA synthesis occurred in the absence of significant adherence. Hence, human endothelial cell DNA synthesis is partially inhibited by contact with sickle erythrocytes. The inhibitory effect of sickle erythrocytes occurs during a brief (1 minute) contact with the endothelial monolayers, and persists for at least 6 hours of 3H-thymidine labeling

Esterase inhibition by synergists in the western flower thrips Frankliniella occidentalis.

Science.gov (United States)

López-Soler, Neus; Cervera, Amelia; Quinto, Vicente; Abellán, Jaime; Bielza, Pablo; Martínez-Pardo, Rafael; Garcerá, Maria Dolores

2011-12-01

Western flower thrips (WFT), Frankliniella occidentalis (Pergande), is among the most important crop pests in the south-eastern region of Spain. Its increasing resistance to insecticides constitutes a serious problem, and understanding the mechanisms involved is therefore of great interest. Use of synergists to inhibit the enzymes involved in insecticide detoxification is widely used to determine their responsibility for insecticide resistance. However, they do not always act as intended or expected, and caution must be exercised when interpreting synergist results. Laboratory-selected strains of WFT were used to analyse the effects of the synergists piperonyl butoxide (PBO), S,S,S-tributyl phosphorotrithioate (DEF) and methiocarb on total esterase activity. Significant differences were found, indicating esterase activity inhibition by DEF, a lower effect for methiocarb and a small inhibition of the activity by PBO. Esterase isoenzyme inhibition by these compounds showed a similar result; this assay revealed an extreme sensitivity of Triplet A (resistance-associated esterases) to DEF. In an in vivo assay carried out with these compounds at different incubation times, only DEF caused posterior in vitro esterase activity inhibition, with a maximum effect 1 h after treatment. In this work, only DEF shows true synergistic inhibition of WFT esterases. Copyright © 2011 Society of Chemical Industry.

Acylation of proteins with myristic acid occurs cotranslationally

International Nuclear Information System (INIS)

Wilcox, C.; Hu, J.S.; Olson, E.N.

1987-01-01

Several proteins of viral and cellular origin are acylated with myristic acid early during their biogenesis. To investigate the possibility that myristylation occurred cotranslationally, the BC 3 H1 muscle cell line, which contains a broad array of myristylated proteins, was pulse-labeled with [ 3 H]myristic acid. Nascent polypeptide chains covalently associated with transfer RNA were isolated subsequently by ion-exchange chromatography. [ 3 H]Myristate was attached to nascent chains through an amide linkage and was identified by thin-layer chromatography after its release from nascent chains by acid methanolysis. Inhibition of cellular protein synthesis with puromycin resulted in cessation of [ 3 H]myristate-labeling of nascent chains, in agreement with the dependence of this modification on protein synthesis in vivo. These data represent a direct demonstration that myristylation of proteins is a cotranslational modification

[Pt(O,O’-acac)(γ-acac)(DMS)] Alters SH-SY5Y Cell Migration and Invasion by the Inhibition of Na+/H+ Exchanger Isoform 1 Occurring through a PKC-ε/ERK/mTOR Pathway

Science.gov (United States)

Muscella, Antonella; Vetrugno, Carla; Calabriso, Nadia; Cossa, Luca Giulio; De Pascali, Sandra Angelica; Fanizzi, Francesco Paolo; Marsigliante, Santo

2014-01-01

We previously showed that [Pt(O,O’-acac)(γ-acac)(DMS)] ([Pt(acac)2(DMS)]) exerted substantial cytotoxic effects in SH-SY5Y neuroblastoma cells, and decreased metalloproteases (MMPs) production and cells migration in MCF-7 breast cancer cells. The ubiquitously distributed sodium-hydrogen antiporter 1 (NHE1) is involved in motility and invasion of many solid tumours. The present study focuses on the effects of [Pt(acac)2(DMS)] in SH-SY5Y cell migration and also on the possibility that NHE1 may be involved in such effect. After sublethal [Pt(acac)2(DMS)] treatment cell migration was examined by wounding assay and cell invasion by transwell assay. NHE1 activity was measured in BCECF-loaded SH-SY5Y as the rate of Na+-dependent intracellular pH recovery in response to an acute acid pulse. Gelatin zymography for MMP-2/9 activities, Western blottings of MMPs, MAPKs, mTOR, S6 and PKCs and small interfering RNAs to PKC-ε/-δ mRNA were performed. Sublethal concentrations of [Pt(acac)2(DMS)] decreases NHE1 activity, inhibites cell migration and invasion and decreases expression and activity of MMP-2 and -9. [Pt(acac)2(DMS)] administered to SH-SY5Y cells provokes the increment of ROS, generated by NADPH oxidase, responsible for the PKC-ε and PKC-δ activation. Whilst PKC-δ activates p38/MAPK, responsible for the inhibition of MMP-2 and -9 secretion, PKC-ε activates a pathway made of ERK1/2, mTOR and S6K responsible for the inhibition of NHE1 activity and cell migration. In conclusion, we have shown a drastic impairment in tumour cell metastatization in response to inhibition of NHE1 and MMPs activities by [Pt(acac)2(DMS)] occurring through a novel mechanism mediated by PKC-δ/-ε activation. PMID:25372487

[Pt(O,O'-acac)(γ-acac)(DMS)] alters SH-SY5Y cell migration and invasion by the inhibition of Na+/H+ exchanger isoform 1 occurring through a PKC-ε/ERK/mTOR Pathway.

Science.gov (United States)

Muscella, Antonella; Vetrugno, Carla; Calabriso, Nadia; Cossa, Luca Giulio; De Pascali, Sandra Angelica; Fanizzi, Francesco Paolo; Marsigliante, Santo

2014-01-01

We previously showed that [Pt(O,O'-acac)(γ-acac)(DMS)] ([Pt(acac)2(DMS)]) exerted substantial cytotoxic effects in SH-SY5Y neuroblastoma cells, and decreased metalloproteases (MMPs) production and cells migration in MCF-7 breast cancer cells. The ubiquitously distributed sodium-hydrogen antiporter 1 (NHE1) is involved in motility and invasion of many solid tumours. The present study focuses on the effects of [Pt(acac)2(DMS)] in SH-SY5Y cell migration and also on the possibility that NHE1 may be involved in such effect. After sublethal [Pt(acac)2(DMS)] treatment cell migration was examined by wounding assay and cell invasion by transwell assay. NHE1 activity was measured in BCECF-loaded SH-SY5Y as the rate of Na+-dependent intracellular pH recovery in response to an acute acid pulse. Gelatin zymography for MMP-2/9 activities, Western blottings of MMPs, MAPKs, mTOR, S6 and PKCs and small interfering RNAs to PKC-ε/-δ mRNA were performed. Sublethal concentrations of [Pt(acac)2(DMS)] decreases NHE1 activity, inhibits cell migration and invasion and decreases expression and activity of MMP-2 and -9. [Pt(acac)2(DMS)] administered to SH-SY5Y cells provokes the increment of ROS, generated by NADPH oxidase, responsible for the PKC-ε and PKC-δ activation. Whilst PKC-δ activates p38/MAPK, responsible for the inhibition of MMP-2 and -9 secretion, PKC-ε activates a pathway made of ERK1/2, mTOR and S6K responsible for the inhibition of NHE1 activity and cell migration. In conclusion, we have shown a drastic impairment in tumour cell metastatization in response to inhibition of NHE1 and MMPs activities by [Pt(acac)2(DMS)] occurring through a novel mechanism mediated by PKC-δ/-ε activation.

[MAXIMUM SINGLE DOSE OF COLLOIDAL SILVER NEGATIVELY AFFECTS ERYTHROPOIESIS IN VITRO].

Science.gov (United States)

Tishevskayal, N V; Zakharovl, Y M; Bolotovl, A A; Arkhipenko, Yu V; Sazontova, T G

2015-01-01

Erythroblastic islets (EI) of rat bone marrow were cultured for 24 h in the presence of silver nanoparticles (1.07 · 10(-4) mg/ml; 1.07 · 10(-3) mg/ml; and 1.07 · 10(-2) mg/mL). The colloidal silver at 1.07 · 10(-3) mg/ml concentration inhibited the formation of new Elby disrupting contacts of bone marrow macrophages with CFU-E (erythropoiesis de novo) by 65.3% (p Colloidal silver nanoparticles suppressed the reconstruction of erythropoiesis and inhibited the formation of new EI by disrupting contacts of CFU-E and central macrophages with matured erythroidal "crown" (erythropoiesis de repeto). The colloidal silver concentration of 1.07 · 10(-3) mg/ml in the culture medium also reduced the number of self-reconstructing EI by 67.5% (p colloidal silver reduced this value by 93.7% (p Silver nanoparticles retarded maturation of erythroid cells at the stage of oxiphylic normoblast denucleation: 1.07 · 10(-3) mg/ml colloidal silver increased the number of mature El by 53% (p colloidal silver in concentration equivalent to the maximum single dose is related to the effect of silver nanoparticles rather than glycerol present in the colloidal suspension.

Cortical organization of inhibition-related functions and modulation by psychopathology.

Science.gov (United States)

Warren, Stacie L; Crocker, Laura D; Spielberg, Jeffery M; Engels, Anna S; Banich, Marie T; Sutton, Bradley P; Miller, Gregory A; Heller, Wendy

2013-01-01

Individual differences in inhibition-related functions have been implicated as risk factors for a broad range of psychopathology, including anxiety and depression. Delineating neural mechanisms of distinct inhibition-related functions may clarify their role in the development and maintenance of psychopathology. The present study tested the hypothesis that activity in common and distinct brain regions would be associated with an ecologically sensitive, self-report measure of inhibition and a laboratory performance measure of prepotent response inhibition. Results indicated that sub-regions of DLPFC distinguished measures of inhibition, whereas left inferior frontal gyrus and bilateral inferior parietal cortex were associated with both types of inhibition. Additionally, co-occurring anxiety and depression modulated neural activity in select brain regions associated with response inhibition. Results imply that specific combinations of anxiety and depression dimensions are associated with failure to implement top-down attentional control as reflected in inefficient recruitment of posterior DLPFC and increased activation in regions associated with threat (MTG) and worry (BA10). Present findings elucidate possible neural mechanisms of interference that could help explain executive control deficits in psychopathology.

Cortical organization of inhibition-related functions and modulation by psychopathology

Directory of Open Access Journals (Sweden)

Stacie L. Warren

2013-06-01

Full Text Available Individual differences in inhibition-related functions have been implicated as risk factors for a broad range of psychopathology, including anxiety and depression. Delineating neural mechanisms of distinct inhibition-related functions may clarify their role in the development and maintenance of psychopathology. The present study tested the hypothesis that activity in common and distinct brain regions would be associated with an ecologically sensitive, self-report measure of inhibition and a laboratory performance measure of prepotent response inhibition. Results indicated that sub-regions of DLPFC distinguished measures of inhibition, whereas left inferior frontal gyrus and bilateral inferior parietal cortex were associated with both types of inhibition. Additionally, co-occurring anxiety and depression modulated neural activity in select brain regions associated with response inhibition. Results imply that specific combinations of anxiety and depression dimensions are associated with failure to implement top-down attentional control as reflected in inefficient recruitment of posterior DLPFC and increased activation in regions associated with threat (MTG and worry (BA10. Present findings elucidate possible neural mechanisms of interference that could help explain executive control deficits in psychopathology.

Does combined strength training and local vibration improve isometric maximum force? A pilot study.

Science.gov (United States)

Goebel, Ruben; Haddad, Monoem; Kleinöder, Heinz; Yue, Zengyuan; Heinen, Thomas; Mester, Joachim

2017-01-01

The aim of the study was to determine whether a combination of strength training (ST) and local vibration (LV) improved the isometric maximum force of arm flexor muscles. ST was applied to the left arm of the subjects; LV was applied to the right arm of the same subjects. The main aim was to examine the effect of LV during a dumbbell biceps curl (Scott Curl) on isometric maximum force of the opposite muscle among the same subjects. It is hypothesized, that the intervention with LV produces a greater gain in isometric force of the arm flexors than ST. Twenty-seven collegiate students participated in the study. The training load was 70% of the individual 1 RM. Four sets with 12 repetitions were performed three times per week during four weeks. The right arm of all subjects represented the vibration trained body side (VS) and the left arm served as the traditional trained body side (TTS). A significant increase of isometric maximum force in both body sides (Arms) occurred. VS, however, significantly increased isometric maximum force about 43% in contrast to 22% of the TTS. The combined intervention of ST and LC improves isometric maximum force of arm flexor muscles. III.

Xylitol-mediated transient inhibition of ribitol utilization by Lactobacillus casei.

OpenAIRE

London, J; Hausman, S

1982-01-01

The growth of Lactobacillus casei strain Cl-16 at the expense or ribitol was inhibited if the non-metabolizable substrate xylitol was included in the medium at concentrations of 6 mM or greater. At these concentrations, xylitol, did not competitively inhibit ribitol transport. The cessation of growth was caused by the intracellular accumulation of xylitol-5-phosphate, which occurred because growth on ribitol had gratuitously induced a functional xylitol-specific phosphotransferase system but ...

Maximum concentrations at work and maximum biologically tolerable concentration for working materials 1991

International Nuclear Information System (INIS)

1991-01-01

The meaning of the term 'maximum concentration at work' in regard of various pollutants is discussed. Specifically, a number of dusts and smokes are dealt with. The valuation criteria for maximum biologically tolerable concentrations for working materials are indicated. The working materials in question are corcinogeneous substances or substances liable to cause allergies or mutate the genome. (VT) [de

40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

Science.gov (United States)

2010-07-01

... cylinders having an internal diameter of 13.0 cm and a 15.5 cm stroke length, the rounded displacement would... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Maximum engine power, displacement... Maximum engine power, displacement, power density, and maximum in-use engine speed. This section describes...

Preclinical Characterization of Naturally Occurring Polyketide Cyclophilin Inhibitors from the Sanglifehrin Family▿†

Science.gov (United States)

Gregory, Matthew A.; Bobardt, Michael; Obeid, Susan; Chatterji, Udayan; Coates, Nigel J.; Foster, Teresa; Gallay, Philippe; Leyssen, Pieter; Moss, Steven J.; Neyts, Johan; Nur-e-Alam, Mohammad; Paeshuyse, Jan; Piraee, Mahmood; Suthar, Dipen; Warneck, Tony; Zhang, Ming-Qiang; Wilkinson, Barrie

2011-01-01

Cyclophilin inhibitors currently in clinical trials for hepatitis C virus (HCV) are all analogues of cyclosporine (CsA). Sanglifehrins are a group of naturally occurring cyclophilin binding polyketides that are structurally distinct from the cyclosporines and are produced by a microorganism amenable to biosynthetic engineering for lead optimization and large-scale production by fermentation. Preclinical characterization of the potential utility of this class of compounds for the treatment of HCV revealed that the natural sanglifehrins A to D are all more potent than CsA at disrupting formation of the NS5A-CypA, -CypB, and -CypD complexes and at inhibition of CypA, CypB, and CypD isomerase activity. In particular, sanglifehrin B (SfB) was 30- to 50-fold more potent at inhibiting the isomerase activity of all Cyps tested than CsA and was also shown to be a more potent inhibitor of the 1b subgenomic replicon (50% effective concentrations [EC50s] of 0.070 μM and 0.16 μM in Huh 5-2 and Huh 9-13 cells, respectively). Physicochemical and mouse pharmacokinetic analyses revealed low oral bioavailability (F 5 h). These data demonstrate that naturally occurring sanglifehrins are suitable lead compounds for the development of novel analogues that are less immunosuppressive and that have improved metabolism and pharmacokinetic properties. PMID:21383094

Credal Networks under Maximum Entropy

OpenAIRE

Lukasiewicz, Thomas

2013-01-01

We apply the principle of maximum entropy to select a unique joint probability distribution from the set of all joint probability distributions specified by a credal network. In detail, we start by showing that the unique joint distribution of a Bayesian tree coincides with the maximum entropy model of its conditional distributions. This result, however, does not hold anymore for general Bayesian networks. We thus present a new kind of maximum entropy models, which are computed sequentially. ...

Maximum Entropy in Drug Discovery

Directory of Open Access Journals (Sweden)

Chih-Yuan Tseng

2014-07-01

Full Text Available Drug discovery applies multidisciplinary approaches either experimentally, computationally or both ways to identify lead compounds to treat various diseases. While conventional approaches have yielded many US Food and Drug Administration (FDA-approved drugs, researchers continue investigating and designing better approaches to increase the success rate in the discovery process. In this article, we provide an overview of the current strategies and point out where and how the method of maximum entropy has been introduced in this area. The maximum entropy principle has its root in thermodynamics, yet since Jaynes’ pioneering work in the 1950s, the maximum entropy principle has not only been used as a physics law, but also as a reasoning tool that allows us to process information in hand with the least bias. Its applicability in various disciplines has been abundantly demonstrated. We give several examples of applications of maximum entropy in different stages of drug discovery. Finally, we discuss a promising new direction in drug discovery that is likely to hinge on the ways of utilizing maximum entropy.

Maximum Quantum Entropy Method

OpenAIRE

Sim, Jae-Hoon; Han, Myung Joon

2018-01-01

Maximum entropy method for analytic continuation is extended by introducing quantum relative entropy. This new method is formulated in terms of matrix-valued functions and therefore invariant under arbitrary unitary transformation of input matrix. As a result, the continuation of off-diagonal elements becomes straightforward. Without introducing any further ambiguity, the Bayesian probabilistic interpretation is maintained just as in the conventional maximum entropy method. The applications o...

Various processes occurring in strong interactions between heavy ions: Compound nucleus formation, incomplete fusion, and quasifission

International Nuclear Information System (INIS)

Lefort, M.

1975-01-01

This paper deals with the problem of various deep processes occurring when two complex nuclei enter in collision. It is suggested that very deep inelastic processes may lead to either a compound nucleus or a composite system which shortly decays into two fission fragments (quasifission process). Particularly for heavy projectiles and targets, the predominant Coulomb potential inhibits the compound nucleus formation for low l waves. Then a critical angular momentum can be defined as the limit below which both processes (quasifission and compound nucleus formation) occur. For the heaviest nuclei, nearly all l waves below l) contribute to the quasifission phenomenon

Weighted Maximum-Clique Transversal Sets of Graphs

OpenAIRE

Chuan-Min Lee

2011-01-01

A maximum-clique transversal set of a graph G is a subset of vertices intersecting all maximum cliques of G. The maximum-clique transversal set problem is to find a maximum-clique transversal set of G of minimum cardinality. Motivated by the placement of transmitters for cellular telephones, Chang, Kloks, and Lee introduced the concept of maximum-clique transversal sets on graphs in 2001. In this paper, we study the weighted version of the maximum-clique transversal set problem for split grap...

Maximum power demand cost

International Nuclear Information System (INIS)

Biondi, L.

1998-01-01

The charging for a service is a supplier's remuneration for the expenses incurred in providing it. There are currently two charges for electricity: consumption and maximum demand. While no problem arises about the former, the issue is more complicated for the latter and the analysis in this article tends to show that the annual charge for maximum demand arbitrarily discriminates among consumer groups, to the disadvantage of some [it

Prevention of 5-fluorouracil-caused growth inhibition in Sordaria fimicola.

Science.gov (United States)

Schoen, H F; Berech, J

1977-02-01

Growth (dry weight accumulation) of Sordaria fimicola in standing liquid culture (sucrose-nitrate-salts-vitamins) is inhibited by the presence of 5 muM 5-fluorouracil in the medium. This inhibition is completely prevented by uracil, deoxyuridine, and 5-bromouracil, partly prevented (40 to 90% of growth observed without 5-fluorouracil) by uridine, thymidine, and 5-bromodeoxyuridine, and slightly prevented by trifluorothymine, cytosine, cytidine, deoxycytidine, and 5-methylcytosine (all at 0.5 to 1 mM). Thymidine and thymine riboside were without any apparent effect. Growth is also inhibited by 0.2 mM 6-azauracil, and this inhibition was completely prevented by uracil and uridine, partly prevented by deoxyuridine, 5-bromouracil, cytidine, and 5-methylcytosine, and slightly prevented by thymine, thymidine, 5-bromodeoxyuridine, cytosine, and deoxycytidine. The data suggest that the observed inhibition of growth by 5-fluorouracil is due to inhibition of both ribonucleic acid and deoxyribonucleic acid synthesis. The data also allow inferences concerning pyrimidine interconversions in S. fimicola; i.e., thymine can be anabolized to thymidylic acid without first being demethylated, although demethylation appears to occur also.

Corrosion inhibition of aluminum 6063 using some pharmaceutical compounds

International Nuclear Information System (INIS)

Fouda, A.S.; Al-Sarawy, A.A.; Ahmed, F.Sh.; El-Abbasy, H.M.

2009-01-01

The corrosion inhibition characteristics of some pharmaceutical compounds on aluminum 6063 in 0.5 mol l -1 H 3 PO 4 has been studied using weight loss and galvanostatic polarization techniques. Results showed that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency increased with increasing inhibitor concentration, but decreased with increasing temperature. The adsorption of first group pharmaceutical compounds on the metal surface is found to obey Frumkin's adsorption isotherm, but the adsorption of second group pharmaceutical compounds is found to obey Temkin's adsorption isotherm. Thermodynamic parameters for adsorption process were determined. Galvanostatic polarization studies showed that first and second groups' pharmaceutical compounds are mixed-type inhibitors and the results obtained from the two techniques are in good agreement

Inhibition of mitochondrial respiration by the anticancer agent 2-methoxyestradiol

International Nuclear Information System (INIS)

Hagen, Thilo; D'Amico, Gabriela; Quintero, Marisol; Palacios-Callender, Miriam; Hollis, Veronica; Lam, Francis; Moncada, Salvador

2004-01-01

2-Methoxyestradiol (2ME2), a naturally occurring metabolite of estradiol, is known to have antiproliferative, antiangiogenic, and proapoptotic activity. Mechanistically, 2ME2 has been shown to downregulate hypoxia-inducible factor 1α (HIF1α) and to induce apoptosis in tumour cells by generating reactive oxygen species (ROS). In this study we report that 2ME2 inhibits mitochondrial respiration in both intact cells and submitochondrial particles, and that this effect is due to inhibition of complex I of the mitochondrial electron transport chain (ETC). The prevention by 2ME2 of hypoxia-induced stabilisation of HIF1α in HEK293 cells was found not to be due to an effect on HIF1α synthesis but rather to an effect on protein degradation. This is in agreement with our recent observation using other inhibitors of mitochondrial respiration which bring about rapid degradation of HIF1α in hypoxia due to increased availability of oxygen and reactivation of prolyl hydroxylases. The concentrations of 2ME2 that inhibited complex I also induced the generation of ROS. 2ME2 did not, however, cause generation of ROS in 143B rho - cells, which lack a functional mitochondrial ETC. We conclude that inhibition of mitochondrial respiration explains, at least in part, the effect of 2ME2 on hypoxia-dependent HIF1α stabilisation and cellular ROS production. Since these actions of 2ME2 occur at higher concentrations than those known to inhibit cell proliferation, it remains to be established whether they contribute to its therapeutic effect

Loss of signal transduction and inhibition of lymphocyte locomotion in a ground-based model of microgravity

Science.gov (United States)

Sundaresan, Alamelu; Risin, Diana; Pellis, Neal R.; McIntire, L. V. (Principal Investigator)

2002-01-01

Inflammatory adherence to, and locomotion through the interstitium is an important component of the immune response. Conditions such as microgravity and modeled microgravity (MMG) severely inhibit lymphocyte locomotion in vitro through gelled type I collagen. We used the NASA rotating wall vessel bioreactor or slow-turning lateral vessel as a prototype for MMG in ground-based experiments. Previous experiments from our laboratory revealed that when lymphocytes (human peripheral blood mononuclear cells [PBMCs]) were first activated with phytohemaglutinin followed by exposure to MMG, locomotory capacity was not affected. In the present study, MMG inhibits lymphocyte locomotion in a manner similar to that observed in microgravity. Phorbol myristate acetate (PMA) treatment of PBMCs restored lost locomotory capacity by a maximum of 87%. Augmentation of cellular calcium flux with ionomycin had no restorative effect. Treatment of lymphocytes with mitomycin C prior to exposure to MMG, followed by PMA, restored locomotion to the same extent as when nonmitomycin C-treated lymphocytes were exposed to MMG (80-87%), suggesting that deoxyribonucleic acid replication is not essential for the restoration of locomotion. Thus, direct activation of protein kinase C (PKC) with PMA was effective in restoring locomotion in MMG comparable to the normal levels seen in Ig cultures. Therefore, in MMG, lymphocyte calcium signaling pathways were functional, with defects occurring at either the level of PKC or upstream of PKC.

A Fast Algorithm for Maximum Likelihood Estimation of Harmonic Chirp Parameters

DEFF Research Database (Denmark)

Jensen, Tobias Lindstrøm; Nielsen, Jesper Kjær; Jensen, Jesper Rindom

2017-01-01

. A statistically efficient estimator for extracting the parameters of the harmonic chirp model in additive white Gaussian noise is the maximum likelihood (ML) estimator which recently has been demonstrated to be robust to noise and accurate --- even when the model order is unknown. The main drawback of the ML......The analysis of (approximately) periodic signals is an important element in numerous applications. One generalization of standard periodic signals often occurring in practice are harmonic chirp signals where the instantaneous frequency increases/decreases linearly as a function of time...

Maximum parsimony, substitution model, and probability phylogenetic trees.

Science.gov (United States)

Weng, J F; Thomas, D A; Mareels, I

2011-01-01

The problem of inferring phylogenies (phylogenetic trees) is one of the main problems in computational biology. There are three main methods for inferring phylogenies-Maximum Parsimony (MP), Distance Matrix (DM) and Maximum Likelihood (ML), of which the MP method is the most well-studied and popular method. In the MP method the optimization criterion is the number of substitutions of the nucleotides computed by the differences in the investigated nucleotide sequences. However, the MP method is often criticized as it only counts the substitutions observable at the current time and all the unobservable substitutions that really occur in the evolutionary history are omitted. In order to take into account the unobservable substitutions, some substitution models have been established and they are now widely used in the DM and ML methods but these substitution models cannot be used within the classical MP method. Recently the authors proposed a probability representation model for phylogenetic trees and the reconstructed trees in this model are called probability phylogenetic trees. One of the advantages of the probability representation model is that it can include a substitution model to infer phylogenetic trees based on the MP principle. In this paper we explain how to use a substitution model in the reconstruction of probability phylogenetic trees and show the advantage of this approach with examples.

Effect of ethanol and methanol on growth of ruminal bacteria Selenomonas ruminantium and Butyrivibrio fibrisolvens.

Science.gov (United States)

Patterson, J A; Ricke, S C

2015-01-01

The effect of ethanol and methanol on growth of several ruminal bacterial strains was examined. Ethanol concentrations as low as 0.2% had a significant, but moderate, inhibitory effect on lag time or growth over time and 3.3% ethanol significantly inhibited maximum optical density obtained by both Selenomonas ruminantium and Butyrivibrio fibrisolvens. Little growth of either strain occurred at 10% ethanol concentrations. Methanol concentrations below 0.5% had little effect on either growth or maximum optical density of Selenomonas ruminantium whereas methanol concentrations below 3.3% had little effect on growth or maximum optical density of Butyrivibrio fibrisolvens. Higher methanol concentrations increasingly inhibited growth of both strains and no growth occurred at a 10% methanol concentration. Concentrations of ethanol or methanol used to add hydrophobic compounds to culture media should be kept below 1%.

Maximum entropy estimation of a Benzene contaminated plume using ecotoxicological assays

International Nuclear Information System (INIS)

Wahyudi, Agung; Bartzke, Mariana; Küster, Eberhard; Bogaert, Patrick

2013-01-01

Ecotoxicological bioassays, e.g. based on Danio rerio teratogenicity (DarT) or the acute luminescence inhibition with Vibrio fischeri, could potentially lead to significant benefits for detecting on site contaminations on qualitative or semi-quantitative bases. The aim was to use the observed effects of two ecotoxicological assays for estimating the extent of a Benzene groundwater contamination plume. We used a Maximum Entropy (MaxEnt) method to rebuild a bivariate probability table that links the observed toxicity from the bioassays with Benzene concentrations. Compared with direct mapping of the contamination plume as obtained from groundwater samples, the MaxEnt concentration map exhibits on average slightly higher concentrations though the global pattern is close to it. This suggest MaxEnt is a valuable method to build a relationship between quantitative data, e.g. contaminant concentrations, and more qualitative or indirect measurements, in a spatial mapping framework, which is especially useful when clear quantitative relation is not at hand. - Highlights: ► Ecotoxicological shows significant benefits for detecting on site contaminations. ► MaxEnt to rebuild qualitative link on concentration and ecotoxicological assays. ► MaxEnt shows similar pattern when compared with concentrations map of groundwater. ► MaxEnt is a valuable method especially when quantitative relation is not at hand. - A Maximum Entropy method to rebuild qualitative relationships between Benzene groundwater concentrations and their ecotoxicological effect.

49 CFR 230.24 - Maximum allowable stress.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the ultimate...

Analysis of Maximum Reasonably Foreseeable Accidents for the Yucca Mountain Draft Environmental Impact Statement (DEIS)

International Nuclear Information System (INIS)

Ross, S.B.; Best, R.E.; Maheras, S.J.; McSweeney, T.I.

2001-01-01

Accidents could occur during the transportation of spent nuclear fuel and high-level radioactive waste. This paper describes the risks and consequences to the public from accidents that are highly unlikely but that could have severe consequences. The impact of these accidents would include those to a collective population and to hypothetical maximally exposed individuals (MEIs). This document discusses accidents with conditions that have a chance of occurring more often than 1 in 10 million times in a year, called ''maximum reasonably foreseeable accidents''. Accidents and conditions less likely than this are not considered to be reasonably foreseeable

Co-Occurring Disorders

Science.gov (United States)

... the mental health field. Alcohol and Drug Abuse, Addiction and Co-occurring Disorders: Co-occurring Disorders and ... 500 Montgomery Street, Suite 820 Alexandria, VA 22314 Phone (703) 684.7722 Toll Free (800) 969.6642 ...

A maximum power point tracking for photovoltaic-SPE system using a maximum current controller

Energy Technology Data Exchange (ETDEWEB)

Muhida, Riza [Osaka Univ., Dept. of Physical Science, Toyonaka, Osaka (Japan); Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Park, Minwon; Dakkak, Mohammed; Matsuura, Kenji [Osaka Univ., Dept. of Electrical Engineering, Suita, Osaka (Japan); Tsuyoshi, Akira; Michira, Masakazu [Kobe City College of Technology, Nishi-ku, Kobe (Japan)

2003-02-01

Processes to produce hydrogen from solar photovoltaic (PV)-powered water electrolysis using solid polymer electrolysis (SPE) are reported. An alternative control of maximum power point tracking (MPPT) in the PV-SPE system based on the maximum current searching methods has been designed and implemented. Based on the characteristics of voltage-current and theoretical analysis of SPE, it can be shown that the tracking of the maximum current output of DC-DC converter in SPE side will track the MPPT of photovoltaic panel simultaneously. This method uses a proportional integrator controller to control the duty factor of DC-DC converter with pulse-width modulator (PWM). The MPPT performance and hydrogen production performance of this method have been evaluated and discussed based on the results of the experiment. (Author)

Tandem-pore K+ channels mediate inhibition of orexin neurons by glucose

DEFF Research Database (Denmark)

Burdakov, Denis; Jensen, Lise T; Alexopoulos, Haris

2006-01-01

Glucose-inhibited neurons orchestrate behavior and metabolism according to body energy levels, but how glucose inhibits these cells is unknown. We studied glucose inhibition of orexin/hypocretin neurons, which promote wakefulness (their loss causes narcolepsy) and also regulate metabolism...... and reward. Here we demonstrate that their inhibition by glucose is mediated by ion channels not previously implicated in central or peripheral glucose sensing: tandem-pore K(+) (K(2P)) channels. Importantly, we show that this electrical mechanism is sufficiently sensitive to encode variations in glucose...... levels reflecting those occurring physiologically between normal meals. Moreover, we provide evidence that glucose acts at an extracellular site on orexin neurons, and this information is transmitted to the channels by an intracellular intermediary that is not ATP, Ca(2+), or glucose itself...

Effect of Ovality on Maximum External Pressure of Helically Coiled Steam Generator Tubes with a Rectangular Wear

Energy Technology Data Exchange (ETDEWEB)

Shin, Dong In; Lim, Eun Mo; Huh, Nam Su [Seoul National Univ. of Science and Technology, Seoul (Korea, Republic of); Choi, Shin Beom; Yu, Je Yong; Kim, Ji Ho; Choi, Suhn [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

A structural integrity of steam generator tubes of nuclear power plants is one of crucial parameters for safe operation of nuclear power plants. Thus, many studies have been made to provide engineering methods to assess integrity of defective tubes of commercial nuclear power plants considering its operating environments and defect characteristics. As described above, the geometric and operating conditions of steam generator tubes in integral reactor are significantly different from those of commercial reactor. Therefore, the structural integrity assessment of defective tubes of integral reactor taking into account its own operating conditions and geometric characteristics, i. e., external pressure and helically coiled shape, should be made to demonstrate compliance with the current design criteria. Also, ovality is very specific characteristics of the helically coiled tube because it is occurred during the coiling processes. The wear, occurring from FIV (Flow Induced Vibration) and so on, is main degradation of steam generator tube. In the present study, maximum external pressure of helically coiled steam generator tube with wear is predicted based on the detailed 3-dimensional finite element analysis. As for shape of wear defect, the rectangular shape is considered. In particular, the effect of ovality on the maximum external pressure of helically coiled tubes with rectangular shaped wear is investigated. In the present work, the maximum external pressure of helically coiled steam generator tube with rectangular shaped wear is investigated via detailed 3-D FE analyses. In order to cover a practical range of geometries for defective tube, the variables affecting the maximum external pressure were systematically varied. In particular, the effect of tube ovality on the maximum external pressure is evaluated. It is expected that the present results can be used as a technical backgrounds for establishing a practical structural integrity assessment guideline of

Correlation between maximum isometric strength variables and specific performance of Brazilian military judokas

Directory of Open Access Journals (Sweden)

Michel Moraes Gonçalves

2017-06-01

Full Text Available It was our objective to correlate specific performance in the Special Judo Fitness Test (SJFT and the maximum isometric handgrip (HGSMax, scapular traction (STSMax and lumbar traction (LTSMax strength tests in military judo athletes. Twenty-two military athletes from the judo team of the Brazilian Navy Almirante Alexandrino Instruction Centre, with average age of 26.14 ± 3.31 years old, and average body mass of 83.23 ± 14.14 kg participated in the study. Electronic dynamometry tests for HGSMax, STSMax and LTSMax were conducted. Then, after approximately 1 hour-interval, the SJFT protocol was applied. All variables were adjusted to the body mass of the athletes. Pearson correlation coefficient for statistical analysis was used. The results showed moderate negative correlation between the SJFT index and STSMax (r= -0.550, p= 0.008, strong negative correlations between the SJFT index and HGSMax (r= -0.706, p< 0.001, SJFT index and LTSMax (r= -0.721; p= 0.001, besides the correlation between the sum of the three maximum isometric strength tests and the SJFT index (r= -0.786, p< 0.001. This study concludes that negative correlations occur between the SJFT index and maximum isometric handgrip, shoulder and lumbar traction strength and the sum of the three maximum isometric strength tests in military judokas.

Antibody-mediated neutralization of Ebola virus can occur by two distinct mechanisms

International Nuclear Information System (INIS)

Shedlock, Devon J.; Bailey, Michael A.; Popernack, Paul M.; Cunningham, James M.; Burton, Dennis R.; Sullivan, Nancy J.

2010-01-01

Human Ebola virus causes severe hemorrhagic fever disease with high mortality and there is no vaccine or treatment. Antibodies in survivors occur early, are sustained, and can delay infection when transferred into nonhuman primates. Monoclonal antibodies (mAbs) from survivors exhibit potent neutralizing activity in vitro and are protective in rodents. To better understand targets and mechanisms of neutralization, we investigated a panel of mAbs shown previously to react with the envelope glycoprotein (GP). While one non-neutralizing mAb recognized a GP epitope in the nonessential mucin-like domain, the rest were specific for GP1, were neutralizing, and could be further distinguished by reactivity with secreted GP. We show that survivor antibodies, human KZ52 and monkey JP3K11, were specific for conformation-dependent epitopes comprising residues in GP1 and GP2 and that neutralization occurred by two distinct mechanisms; KZ52 inhibited cathepsin cleavage of GP whereas JP3K11 recognized the cleaved, fusion-active form of GP.

Inhibition of denitrification and N2O emission by urine-derived benzoic and hippuric acid

NARCIS (Netherlands)

Groenigen, van J.W.; Palermo, V.; Kool, D.M.; Kuikman, P.J.

2006-01-01

Hippuric acid (HA) in cattle urine acts as a natural inhibitor of soil N2O emissions. As HA concentration varies with diet, we determined critical HA levels. We also tested the hypothesis that the inhibition occurs because the HA breakdown product benzoic acid (BA) inhibits denitrification rates.

Nickel Inhibits Mitochondrial Fatty Acid Oxidation

Science.gov (United States)

Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

2015-01-01

Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

Maximum skin hyperaemia induced by local heating: possible mechanisms.

Science.gov (United States)

Gooding, Kim M; Hannemann, Michael M; Tooke, John E; Clough, Geraldine F; Shore, Angela C

2006-01-01

Maximum skin hyperaemia (MH) induced by heating skin to > or = 42 degrees C is impaired in individuals at risk of diabetes and cardiovascular disease. Interpretation of these findings is hampered by the lack of clarity of the mechanisms involved in the attainment of MH. MH was achieved by local heating of skin to 42-43 degrees C for 30 min, and assessed by laser Doppler fluximetry. Using double-blind, randomized, placebo-controlled crossover study designs, the roles of prostaglandins were investigated by inhibiting their production with aspirin and histamine, with the H1 receptor antagonist cetirizine. The nitric oxide (NO) pathway was blocked by the NO synthase inhibitor, NG-nitro-L-arginine methyl esther (L-NAME), and enhanced by sildenafil (prevents breakdown of cGMP). MH was not altered by aspirin, cetirizine or sildenafil, but was reduced by L-NAME: median placebo 4.48 V (25th, 75th centiles: 3.71, 4.70) versus L-NAME 3.25 V (3.10, 3.80) (p = 0.008, Wilcoxon signed rank test). Inhibition of NO production (L-NAME) resulted in a more rapid reduction in hyperaemia after heating (p = 0.011), whereas hyperaemia was prolonged in the presence of sildenafil (p = 0.003). The increase in skin blood flow was largely confined to the directly heated area, suggesting that the role of heat-induced activation of the axon reflex was small. NO, but not prostaglandins, histamine or an axon reflex, contributes to the increase in blood flow on heating and NO is also a component of the resolution of MH after heating. Copyright 2006 S. Karger AG, Basel.

Verification of maximum impact force for interim storage cask for the Fast Flux Testing Facility

International Nuclear Information System (INIS)

Chen, W.W.; Chang, S.J.

1996-01-01

The objective of this paper is to perform an impact analysis of the Interim Storage Cask (ISC) of the Fast Flux Test Facility (FFTF) for a 4-ft end drop. The ISC is a concrete cask used to store spent nuclear fuels. The analysis is to justify the impact force calculated by General Atomics (General Atomics, 1994) using the ILMOD computer code. ILMOD determines the maximum force developed by the concrete crushing which occurs when the drop energy has been absorbed. The maximum force, multiplied by the dynamic load factor (DLF), was used to determine the maximum g-level on the cask during a 4-ft end drop accident onto the heavily reinforced FFTF Reactor Service Building's concrete surface. For the analysis, this surface was assumed to be unyielding and the cask absorbed all the drop energy. This conservative assumption simplified the modeling used to qualify the cask's structural integrity for this accident condition

Lake Basin Fetch and Maximum Length/Width

Data.gov (United States)

Minnesota Department of Natural Resources — Linear features representing the Fetch, Maximum Length and Maximum Width of a lake basin. Fetch, maximum length and average width are calcuated from the lake polygon...

Maximum permissible voltage of YBCO coated conductors

Energy Technology Data Exchange (ETDEWEB)

Wen, J.; Lin, B.; Sheng, J.; Xu, J.; Jin, Z. [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Hong, Z., E-mail: zhiyong.hong@sjtu.edu.cn [Department of Electrical Engineering, Shanghai Jiao Tong University, Shanghai (China); Wang, D.; Zhou, H.; Shen, X.; Shen, C. [Qingpu Power Supply Company, State Grid Shanghai Municipal Electric Power Company, Shanghai (China)

2014-06-15

Highlights: • We examine three kinds of tapes’ maximum permissible voltage. • We examine the relationship between quenching duration and maximum permissible voltage. • Continuous I{sub c} degradations under repetitive quenching where tapes reaching maximum permissible voltage. • The relationship between maximum permissible voltage and resistance, temperature. - Abstract: Superconducting fault current limiter (SFCL) could reduce short circuit currents in electrical power system. One of the most important thing in developing SFCL is to find out the maximum permissible voltage of each limiting element. The maximum permissible voltage is defined as the maximum voltage per unit length at which the YBCO coated conductors (CC) do not suffer from critical current (I{sub c}) degradation or burnout. In this research, the time of quenching process is changed and voltage is raised until the I{sub c} degradation or burnout happens. YBCO coated conductors test in the experiment are from American superconductor (AMSC) and Shanghai Jiao Tong University (SJTU). Along with the quenching duration increasing, the maximum permissible voltage of CC decreases. When quenching duration is 100 ms, the maximum permissible of SJTU CC, 12 mm AMSC CC and 4 mm AMSC CC are 0.72 V/cm, 0.52 V/cm and 1.2 V/cm respectively. Based on the results of samples, the whole length of CCs used in the design of a SFCL can be determined.

Receiver function estimated by maximum entropy deconvolution

Institute of Scientific and Technical Information of China (English)

吴庆举; 田小波; 张乃铃; 李卫平; 曾融生

2003-01-01

Maximum entropy deconvolution is presented to estimate receiver function, with the maximum entropy as the rule to determine auto-correlation and cross-correlation functions. The Toeplitz equation and Levinson algorithm are used to calculate the iterative formula of error-predicting filter, and receiver function is then estimated. During extrapolation, reflective coefficient is always less than 1, which keeps maximum entropy deconvolution stable. The maximum entropy of the data outside window increases the resolution of receiver function. Both synthetic and real seismograms show that maximum entropy deconvolution is an effective method to measure receiver function in time-domain.

Extraction and characterization of naturally occurring bioactive peptides from different tissues from Salmon (Salmo salar)

DEFF Research Database (Denmark)

Falkenberg, Susan Skanderup; Nielsen, Henrik Hauch

2011-01-01

used. Combination of different extraction conditions such as with/without boiling, with/without inhibitor and variation of pH resulted in a total of 36 extracts. The activity of the extracts was analyzed in vitro for ACE (angiotensin-converting enzyme) inhibiting activity, and anti-oxidative activity...... (Free Radical Scavenging assay). A number of extracts showed high ACE inhibiting and anti-oxidative activity. The extracts were then size fractionated by ultrafiltration using a 10 kDa filter, and relevant fractions below 10 kDa from gills, skin and belly flap were further fractionated by gel...... is therefore to extract and identify naturally occurring bioactive peptides from different tissues from salmon. A number of aqueous extracts were made from gills, skin and belly flap. In order to preserve the bioactivity of the peptides mild extraction procedures as acidic, basic and aqueous solutions were...

Enhanced longevity by ibuprofen, conserved in multiple species, occurs in yeast through inhibition of tryptophan import.

Directory of Open Access Journals (Sweden)

Chong He

2014-12-01

Full Text Available The common non-steroidal anti-inflammatory drug ibuprofen has been associated with a reduced risk of some age-related pathologies. However, a general pro-longevity role for ibuprofen and its mechanistic basis remains unclear. Here we show that ibuprofen increased the lifespan of Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster, indicative of conserved eukaryotic longevity effects. Studies in yeast indicate that ibuprofen destabilizes the Tat2p permease and inhibits tryptophan uptake. Loss of Tat2p increased replicative lifespan (RLS, but ibuprofen did not increase RLS when Tat2p was stabilized or in an already long-lived strain background impaired for aromatic amino acid uptake. Concomitant with lifespan extension, ibuprofen moderately reduced cell size at birth, leading to a delay in the G1 phase of the cell cycle. Similar changes in cell cycle progression were evident in a large dataset of replicatively long-lived yeast deletion strains. These results point to fundamental cell cycle signatures linked with longevity, implicate aromatic amino acid import in aging and identify a largely safe drug that extends lifespan across different kingdoms of life.

Enhanced Longevity by Ibuprofen, Conserved in Multiple Species, Occurs in Yeast through Inhibition of Tryptophan Import

Science.gov (United States)

He, Chong; Tsuchiyama, Scott K.; Nguyen, Quynh T.; Plyusnina, Ekaterina N.; Terrill, Samuel R.; Sahibzada, Sarah; Patel, Bhumil; Faulkner, Alena R.; Shaposhnikov, Mikhail V.; Tian, Ruilin; Tsuchiya, Mitsuhiro; Kaeberlein, Matt; Moskalev, Alexey A.; Kennedy, Brian K.; Polymenis, Michael

2014-01-01

The common non-steroidal anti-inflammatory drug ibuprofen has been associated with a reduced risk of some age-related pathologies. However, a general pro-longevity role for ibuprofen and its mechanistic basis remains unclear. Here we show that ibuprofen increased the lifespan of Saccharomyces cerevisiae, Caenorhabditis elegans and Drosophila melanogaster, indicative of conserved eukaryotic longevity effects. Studies in yeast indicate that ibuprofen destabilizes the Tat2p permease and inhibits tryptophan uptake. Loss of Tat2p increased replicative lifespan (RLS), but ibuprofen did not increase RLS when Tat2p was stabilized or in an already long-lived strain background impaired for aromatic amino acid uptake. Concomitant with lifespan extension, ibuprofen moderately reduced cell size at birth, leading to a delay in the G1 phase of the cell cycle. Similar changes in cell cycle progression were evident in a large dataset of replicatively long-lived yeast deletion strains. These results point to fundamental cell cycle signatures linked with longevity, implicate aromatic amino acid import in aging and identify a largely safe drug that extends lifespan across different kingdoms of life. PMID:25521617

Mass loss from the southern half of the Greenland Ice Sheet since the Little Ice Age Maximum

DEFF Research Database (Denmark)

Kjeldsen, Kristian Kjellerup; Kjær, Kurt H.; Bjørk, Anders Anker

Northern hemisphere temperatures reached their Holocene minimum and most glaciers reached their maximum during The Little Ice Age (LIA), but the timing of specific cold intervals is site-specific. In southern Greenland, we have compiled data from organic matter incorporated in LIA sediments, used...... retreat. Our results show that the advance of glaciers during the LIA occurs early after the Medieval Warm Period terminating soon after 1200 AD and culminates c. 1500-1600 AD. Historical maps also show that many glaciers on the western coast occupy a still-stand near the LIA maximum until 1900 AD before...

Aluminum Chloride Pretreatment of Elastin Inhibits Elastolysis by Matrix Metalloproteinases and Leads to Inhibition of Elastin-Oriented Calcification

OpenAIRE

Bailey, Michael; Xiao, Hui; Ogle, Matthew; Vyavahare, Naren

2001-01-01

Calcification of elastin occurs in many pathological cardiovascular diseases including atherosclerosis. We have previously shown that purified elastin when subdermally implanted in rats undergoes severe calcification and aluminum chloride (AlCl3) pretreatment of elastin inhibits calcification. In the present study we investigated whether matrix metalloproteinase (MMP) binding to elastin and elastin degradation is prevented by AlCl3 pretreatment. Subdermal implantation of AlCl3-pretreated elas...

Inhibition and recovery of DNA synthesis in human cells after exposure to ultraviolet light

International Nuclear Information System (INIS)

Painter, R.B.

1985-01-01

The inhibition of DNA synthesis in normal human cells by UV is a complex function of fluence because it has several causes. At low fluences, inhibition of replicon initiation is most important. This is made clear by the fact that it occurs to a lesser degree in cells from patients with ataxia telangiectasia (AT). Assuming that only leading strand synthesis is blocked by UV-induced lesions, single lesions between replicons in parental strands for leading strand synthesis inhibit DNA synthesis by acting as temporary blocks until they are replicated by extension of the lagging strand of the adjacent replicon. A more severe inhibition occurs when two lesions are induced between adjacent growing replicons, because one in four possible configurations may result in a long-lived unreplicated region (LLUR). In the absence of excision repair, these may eventually be replicated by activation of an otherwise unused origin within the LLUR. The frequency of LLURs increases steeply with fluence. Activation of normally unused origins to replicate LLURs may facilitate recovery from inhibition of DNA synthesis, but repair of lesions is probably more important. In excision-repair-defective cells, an LLUR without an origin to initiate its replication may be a lethal lesion. (orig.)

Optimal design of the gerotor (2-ellipses) for reducing maximum contact stress

Energy Technology Data Exchange (ETDEWEB)

Kwak, Hyo Seo; Li, Sheng Huan [Dept. of Mechanical Convergence Technology, Pusan National University, Busan (Korea, Republic of); Kim, Chul [School of Mechanical Design and Manufacturing, Busan Institute of Science and Technology, Busan (Korea, Republic of)

2016-12-15

The oil pump, which is used as lubricator of engines and auto transmission, supplies working oil to the rotating elements to prevent wear. The gerotor pump is used widely in the automobile industry. When wear occurs due to contact between an inner rotor and an outer rotor, the efficiency of the gerotor pump decreases rapidly, and elastic deformation from the contacts also causes vibration and noise. This paper reports the optimal design of a gerotor with a 2-ellipses combined lobe shape that reduces the maximum contact stress. An automatic program was developed to calculate Hertzian contact stress of the gerotor using the Matlab and the effect of the design parameter on the maximum contact stress was analyzed. In addition, the method of theoretical analysis for obtaining the contact stress was verified by performing the fluid-structural coupled analysis using the commercial software, Ansys, considering both the driving force of the inner rotor and the fluid pressure, which is generated by working oil.

Evaluation of Energy Dose and Output Power Optimum of Diode’s Laser of 450 nm and 650 nm in Photoantimicrobial Mechanisms Against Inhibition of C. Albicans Biofilm Cells

Science.gov (United States)

Dewi-Astuty, S.; Suhariningsih; Dyah-Astuti, S.; Baktir, A.

2018-03-01

Photoantimicrobial as a pathogenic microbial inhibitory therapy system such as C. albicans in biofilms forms has been studied in vitro. Mechanisms of inhibiting called inactivating used the absorb principles of a dye agents such as chlorophyll against the photon energy of diode laser which any number of ROS product depend on energy doses of a laser, time of irradiation, concentration and time of incubation the dyes agent. The inactivation profile of C. albicans biofilm cells was observed based on cell viability reduction after photoantimicrobial treatment with or without oxygenation by XTT assay test. Results show that the inhibiting significantly with the time incubation of the dye agents and the oxygen degree inside the sample. The inhibition for oxygenation biofilm’s group 10% lower than without oxygenation biofilm’s group at the maximum of reduction of cell viability occurred in the 3hour incubation group. Optimum of inactivation are 89.6% (without oxygenation) and 94.8% (with oxygenation) after irradiation with 450 nm laser (power output 128.73 at energy dose 86.09 J/cm2), While, by 650 nm laser (power output 164.53 mW at energy dose 92.52 J/cm2) irradiation treatment obtained optimum of inactivation are 89.5% (without oxygenation) and 92.3% (with oxygenation).

Free Radical Oxidation in Rat Myocardium after Maximum Permissible Hepatic Resection.

Science.gov (United States)

Ermolaev, P A; Khramykh, T P; Barskaya, L O

2016-03-01

Free radical oxidation in rat myocardial homogenate was studied by chemiluminescent assay during the early terms after maximum permissible liver resection. During this period, activation of free radical oxidation was biphasic. The critical terms characterized by dramatic intensification of free radical oxidation in the myocardium are the first hour and the first day after surgery. The period from 3 to 12 h after surgery, in which the indices of chemiluminescence decrease, can be tentatively termed as the period of "putative wellbeing". Normalization of the free radical oxidation processes in the myocardium occurred by day 7 after surgery.

Inhibition of phospholipase A2 from human plasma by sodium bisulfite

International Nuclear Information System (INIS)

Wiggins, C.W.; Franson, R.C.

1987-01-01

The anti-oxidant sodium bisulfite has been shown to inhibit acid active(lysosomal), non-Ca ++ -dependent phospholipase A 2 (PLA 2 ), and to interact reversibly with unsaturated fatty acids, altering their chromatographic mobility. The authors examined the effect of bisulfite on neutral active, Ca ++ -dependent PLA 2 from human plasma. Using [1- 14 C]oleate-labelled autoclaved E. coli as substrate, PLA 2 activity was inhibited in a dose-dependent manner by bisulfite. Maximal inhibition occurred at 100μM bisulfite. Preincubation of plasma for 0-30 minutes with bisulfite resulted in a time-dependent increase in PLA 2 inhibition. Preincubation of substrate with bisulfite had no such effect. When the plasma PLA 2 was purified 25-fold by SP-Sephadex chromatography it was no longer inhibited by bisulfite. The SP-Sephadex wash through fraction, which contained greater than 95% of the applied protein but not PLA 2 activity, did not inhibit the purified enzyme. When incubated with bisulfite however, the SP-wash through fraction produced dose-dependent inhibition of the purified enzyme. These results indicate that sodium bisulfite inhibits human plasma PLA 2 , in vitro, indirectly by interaction with a factor(s) present in plasma and suggests that anti-oxidants may similarly influence expression of extracellular PLA 2 in vivo

Determination of naturally occurring radionuclides in El-Sin Water

International Nuclear Information System (INIS)

Al-Masri, M.S.; Al-Rayyes, A.H.

2000-01-01

Naturally occurring radionuclides levels have been determined in El-Sin water for the period of 1995 and 1996. water samples were collected from four sites, which are the main drinking water sources of the area. Radon concentration was found to vary between 0.88 Bq/1 in Lattakia main water supply site and 8.4 Bq/1 in El-Sin springs.The highest values found for other radionuclides were 51.6 mBq/1, 18.6 mB/1 and 24.8 mBq/1 for sup 2 sup 2 sup 6 Ra, sup 2 sup 1 sup 0 Po and total uranium (sup 2 sup 3 sup 4 U and sup 2 sup 3 sup 8 U) respectively. These levels are much lower than the maximum permissible levels in drinking water set by international organization.(author)

Inhibition of prolyl 4-hydroxylase decreases muscle fibrosis following chronic rotator cuff tear.

Science.gov (United States)

Gumucio, J P; Flood, M D; Bedi, A; Kramer, H F; Russell, A J; Mendias, C L

2017-01-01

Rotator cuff tears are among the most frequent upper extremity injuries. Current treatment strategies do not address the poor quality of the muscle and tendon following chronic rotator cuff tears. Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor that activates many genes that are important in skeletal muscle regeneration. HIF-1α is inhibited under normal physiological conditions by the HIF prolyl 4-hydroxylases (PHDs). In this study, we used a pharmacological PHD inhibitor, GSK1120360A, to enhance the activity of HIF-1α following the repair of a chronic cuff tear, and measured muscle fibre contractility, fibrosis, gene expression, and enthesis mechanics. Chronic supraspinatus tears were induced in adult rats, and repaired 28 days later. Rats received 0 mg/kg, 3 mg/kg, or 10 mg/kg GSK1120360A daily. Collagen content, contractility, fibre type distribution and size, the expression of genes involved in fibrosis, lipid accumulation, atrophy and inflammation, and the mechanical properties of the enthesis were then assessed two weeks following surgical repair. At two weeks following repair, treatment groups showed increased muscle mass but there was a 15% decrease in force production in the 10 mg/kg group from controls, and no difference between the 0 mg/kg and the 3 mg/kg groups. There was a decrease in the expression of several gene transcripts related to matrix accumulation and fibrosis, and a 50% decrease in collagen content in both treated groups compared with controls. Additionally, the expression of inflammatory genes was reduced in the treated groups compared with controls. Finally, PHD inhibition improved the maximum stress and displacement to failure in repaired tendons. GSK1120360A resulted in improved enthesis mechanics with variable effects on muscle function. PHD inhibition may be beneficial for connective tissue injuries in which muscle atrophy has not occurred.Cite this article: J. P. Gumucio, M. D. Flood, A. Bedi, H. F. Kramer, A. J

Maximum stress estimation model for multi-span waler beams with deflections at the supports using average strains.

Science.gov (United States)

Park, Sung Woo; Oh, Byung Kwan; Park, Hyo Seon

2015-03-30

The safety of a multi-span waler beam subjected simultaneously to a distributed load and deflections at its supports can be secured by limiting the maximum stress of the beam to a specific value to prevent the beam from reaching a limit state for failure or collapse. Despite the fact that the vast majority of accidents on construction sites occur at waler beams in retaining wall systems, no safety monitoring model that can consider deflections at the supports of the beam is available. In this paper, a maximum stress estimation model for a waler beam based on average strains measured from vibrating wire strain gauges (VWSGs), the most frequently used sensors in construction field, is presented. The model is derived by defining the relationship between the maximum stress and the average strains measured from VWSGs. In addition to the maximum stress, support reactions, deflections at supports, and the magnitudes of distributed loads for the beam structure can be identified by the estimation model using the average strains. Using simulation tests on two multi-span beams, the performance of the model is evaluated by estimating maximum stress, deflections at supports, support reactions, and the magnitudes of distributed loads.

Maximum Gene-Support Tree

Directory of Open Access Journals (Sweden)

Yunfeng Shan

2008-01-01

Full Text Available Genomes and genes diversify during evolution; however, it is unclear to what extent genes still retain the relationship among species. Model species for molecular phylogenetic studies include yeasts and viruses whose genomes were sequenced as well as plants that have the fossil-supported true phylogenetic trees available. In this study, we generated single gene trees of seven yeast species as well as single gene trees of nine baculovirus species using all the orthologous genes among the species compared. Homologous genes among seven known plants were used for validation of the finding. Four algorithms—maximum parsimony (MP, minimum evolution (ME, maximum likelihood (ML, and neighbor-joining (NJ—were used. Trees were reconstructed before and after weighting the DNA and protein sequence lengths among genes. Rarely a gene can always generate the “true tree” by all the four algorithms. However, the most frequent gene tree, termed “maximum gene-support tree” (MGS tree, or WMGS tree for the weighted one, in yeasts, baculoviruses, or plants was consistently found to be the “true tree” among the species. The results provide insights into the overall degree of divergence of orthologous genes of the genomes analyzed and suggest the following: 1 The true tree relationship among the species studied is still maintained by the largest group of orthologous genes; 2 There are usually more orthologous genes with higher similarities between genetically closer species than between genetically more distant ones; and 3 The maximum gene-support tree reflects the phylogenetic relationship among species in comparison.

Evaluation of the potential of Trichoderma viride in the control of fungal pathogens of Roselle (Hibiscus sabdariffa L.) in vitro.

Science.gov (United States)

Eslaminejad Parizi, T; Ansaria, Mehdi; Elaminejad, Tahereh

2012-04-01

The potential of Trichoderma viride as a bio-control agent was evaluated in vitro against Roselle pathogens i.e. Phoma exigua, Fusarium nygamai and Rhizoctonia solani[1] using the dual culture technique. Volatile and non-volatile inhibitors of Trichoderma were also evaluated for this purpose. T. viride[2] was shown to have a marked inhibitory effect on the tested pathogens in vitro. Maximum inhibition occurred against P. exigua, with 71.76% reduction in mycelial radial growth. The three pathogens, P. exigua, F. nygamai and R. solani were also found to be susceptible to the volatile inhibitors produced by T. viride, giving rise to growth inhibition of about 68% in each case. When T. viride non-volatile metabolites were tested against the pathogens, maximum inhibition occurred against R. solani (73.95% mycelial growth inhibition), followed by P. exigua (37.17% inhibition). The inhibitory effect of the non-volatile metabolites on F. nygamai was, however, minimal. Copyright © 2012 Elsevier Ltd. All rights reserved.

A comparison of hydraulic architecture in three similarly sized woody species differing in their maximum potential height

Science.gov (United States)

Katherine A. McCulloh; Daniel M. Johnson; Joshua Petitmermet; Brandon McNellis; Frederick C. Meinzer; Barbara Lachenbruch; Nathan Phillips

2015-01-01

The physiological mechanisms underlying the short maximum height of shrubs are not understood. One possible explanation is that differences in the hydraulic architecture of shrubs compared with co-occurring taller trees prevent the shrubs from growing taller. To explore this hypothesis, we examined various hydraulic parameters, including vessel lumen diameter,...

Evolutionary History Underlies Plant Physiological Responses to Global Change Since the Last Glacial Maximum

Science.gov (United States)

Becklin, K. M.; Medeiros, J. S.; Sale, K. R.; Ward, J. K.

2014-12-01

Assessing family and species-level variation in physiological responses to global change across geologic time is critical for understanding factors that underlie changes in species distributions and community composition. Ancient plant specimens preserved within packrat middens are invaluable in this context since they allow for comparisons between co-occurring plant lineages. Here we used modern and ancient plant specimens preserved within packrat middens from the Snake Range, NV to investigate the physiological responses of a mixed montane conifer community to global change since the last glacial maximum. We used a conceptual model to infer relative changes in stomatal conductance and maximum photosynthetic capacity from measures of leaf carbon isotopes, stomatal characteristics, and leaf nitrogen content. Our results indicate that most of the sampled taxa decreased stomatal conductance and/or photosynthetic capacity from glacial to modern times. However, plant families differed in the timing and magnitude of these physiological responses. Additionally, leaf-level responses were more similar within plant families than within co-occurring species assemblages. This suggests that adaptation at the level of leaf physiology may not be the main determinant of shifts in community composition, and that plant evolutionary history may drive physiological adaptation to global change over recent geologic time.

Lithium ions induce prestalk-associated gene expression and inhibit prespore gene expression in Dictyostelium discoideum

NARCIS (Netherlands)

Peters, Dorien J.M.; Lookeren Campagne, Michiel M. van; Haastert, Peter J.M. van; Spek, Wouter; Schaap, Pauline

1989-01-01

We investigated the effect of Li+ on two types of cyclic AMP-regulated gene expression and on basal and cyclic AMP-stimulated inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) levels. Li+ effectively inhibits cyclic AMP-induced prespore gene expression, half-maximal inhibition occurring at about 2mM-LiCl.

Anaerobic co-digestion of desugared molasses with cow manure; focusingon sodium and potassium inhibition

DEFF Research Database (Denmark)

Fang, Cheng; Boe, Kanokwan; Angelidaki, Irini

2011-01-01

dilutions with water and co-digestion with manure. Stable operation at maximum methane yield of 300 mL-CH4/gVSadded was obtained at a mixture of 5% DM in cow manure. The biogas process was inhibited at DM concentrations higher than 15%. Manure was a good base substrate for co-digestion, and a stable...

Maximum neutron flux in thermal reactors

International Nuclear Information System (INIS)

Strugar, P.V.

1968-12-01

Direct approach to the problem is to calculate spatial distribution of fuel concentration if the reactor core directly using the condition of maximum neutron flux and comply with thermal limitations. This paper proved that the problem can be solved by applying the variational calculus, i.e. by using the maximum principle of Pontryagin. Mathematical model of reactor core is based on the two-group neutron diffusion theory with some simplifications which make it appropriate from maximum principle point of view. Here applied theory of maximum principle are suitable for application. The solution of optimum distribution of fuel concentration in the reactor core is obtained in explicit analytical form. The reactor critical dimensions are roots of a system of nonlinear equations and verification of optimum conditions can be done only for specific examples

Technology of sprouting inhibition by irradiation for ginger storage

International Nuclear Information System (INIS)

Feng Shuangqing; Wang Shoujing; Yu Zihou; Sun Shouyi; Zou Jiwan; Lei Peng

2003-01-01

The study results showed that the proper irradiation dose for ginger sprouting inhibition was 0.08-0.40 kGy and the maximum tolerable irradiation dose for ginger was 0.4 kGy. Treatment with proper irradiation combined with PE film package could keep ginger fresh after 120 days of storage and the fresh ratio was above 90%. In order to obtain good storage results, keeping lower absorbed dose ununiformity was necessary. Content of V C and Ca was not affected by the irradiation with 0.08-0.25 kGy

75 FR 43840 - Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for...

Science.gov (United States)

2010-07-27

...-17530; Notice No. 2] RIN 2130-ZA03 Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum... remains at $250. These adjustments are required by the Federal Civil Penalties Inflation Adjustment Act [email protected] . SUPPLEMENTARY INFORMATION: The Federal Civil Penalties Inflation Adjustment Act of 1990...

Half-width at half-maximum, full-width at half-maximum analysis

Indian Academy of Sciences (India)

addition to the well-defined parameter full-width at half-maximum (FWHM). The distribution of ... optical side-lobes in the diffraction pattern resulting in steep central maxima [6], reduc- tion of effects of ... and broad central peak. The idea of.

Isolation of Stem rot Disease Causing Organism of Brinjal and their in-vitro Inhibition with Fungicides and Bio-control Agents

Directory of Open Access Journals (Sweden)

Shaily Javeria

2014-09-01

Full Text Available Different strains of Sclerotinia sclerotiorum were isolated from the diseased samples collected from different hosts and locations. Among the 14 isolates, 12 isolates colonies covered the entire Petri plates within 96 hours but, two isolates from fababean and yellow mustard showed slow colony growth within 96 hours. All isolates produced sclerotia which were varied in number, but the fenugreek isolate produced maximum (43 number of sclerotia and lambs quarter isolate produced minimum number of sclerotia (12 on PDA medium. To examine inhibitory effect of fungicide on the mycelial growth of the pathogen, 9 fungicides were tested in vitro against Sclerotinia sclerotiorum, of those carbendazim, carboxin, topsin-M and carbendazim+ mancozeb (SAAF were found most effective and inhibited the mycelial growth of pathogen up to 100 per cent at 0.05%, 0.1%, and 0.2% concentration. The effect of different bioagents viz., Trichoderma harzianum, T. viride, T. koningii, T. atroviride, T. longibraciatum, Aspergillus niger, Chaetomium globosome and Penicillium notatum in inhibiting the growth of Sclerotinia sclerotiorum was studied through “Dual Culture Technique”. The data showed that among the eight biocontrol agent six were fond effective. The maximum inhibition was found by T. harzianum causing 70.82% inhibition of mycelial growth of the pathogen S. sclerotiorum.

Inhibition of Catalase by Tea Catechins in Free and Cellular State: A Biophysical Approach

Science.gov (United States)

Pal, Sandip; Dey, Subrata Kumar; Saha, Chabita

2014-01-01

Tea flavonoids bind to variety of enzymes and inhibit their activities. In the present study, binding and inhibition of catalase activity by catechins with respect to their structure-affinity relationship has been elucidated. Fluorimetrically determined binding constants for (−)-epigallocatechin gallate (EGCG) and (−)-epicatechin gallate (ECG) with catalase were observed to be 2.27×106 M−1 and 1.66×106 M−1, respectively. Thermodynamic parameters evidence exothermic and spontaneous interaction between catechins and catalase. Major forces of interaction are suggested to be through hydrogen bonding along with electrostatic contributions and conformational changes. Distinct loss of α-helical structure of catalase by interaction with EGCG was captured in circular dichroism (CD) spectra. Gallated catechins demonstrated higher binding constants and inhibition efficacy than non-gallated catechins. EGCG exhibited maximum inhibition of pure catalase. It also inhibited cellular catalase in K562 cancer cells with significant increase in cellular ROS and suppression of cell viability (IC50 54.5 µM). These results decipher the molecular mechanism by which tea catechins interact with catalase and highlight the potential of gallated catechin like EGCG as an anticancer drug. EGCG may have other non-specific targets in the cell, but its anticancer property is mainly defined by ROS accumulation due to catalase inhibition. PMID:25025898

Two-dimensional maximum entropy image restoration

International Nuclear Information System (INIS)

Brolley, J.E.; Lazarus, R.B.; Suydam, B.R.; Trussell, H.J.

1977-07-01

An optical check problem was constructed to test P LOG P maximum entropy restoration of an extremely distorted image. Useful recovery of the original image was obtained. Comparison with maximum a posteriori restoration is made. 7 figures

Maximum power point tracking

International Nuclear Information System (INIS)

Enslin, J.H.R.

1990-01-01

A well engineered renewable remote energy system, utilizing the principal of Maximum Power Point Tracking can be m ore cost effective, has a higher reliability and can improve the quality of life in remote areas. This paper reports that a high-efficient power electronic converter, for converting the output voltage of a solar panel, or wind generator, to the required DC battery bus voltage has been realized. The converter is controlled to track the maximum power point of the input source under varying input and output parameters. Maximum power point tracking for relative small systems is achieved by maximization of the output current in a battery charging regulator, using an optimized hill-climbing, inexpensive microprocessor based algorithm. Through practical field measurements it is shown that a minimum input source saving of 15% on 3-5 kWh/day systems can easily be achieved. A total cost saving of at least 10-15% on the capital cost of these systems are achievable for relative small rating Remote Area Power Supply systems. The advantages at larger temperature variations and larger power rated systems are much higher. Other advantages include optimal sizing and system monitor and control

Irregular activity arises as a natural consequence of synaptic inhibition

International Nuclear Information System (INIS)

Terman, D.; Rubin, J. E.; Diekman, C. O.

2013-01-01

Irregular neuronal activity is observed in a variety of brain regions and states. This work illustrates a novel mechanism by which irregular activity naturally emerges in two-cell neuronal networks featuring coupling by synaptic inhibition. We introduce a one-dimensional map that captures the irregular activity occurring in our simulations of conductance-based differential equations and mathematically analyze the instability of fixed points corresponding to synchronous and antiphase spiking for this map. We find that the irregular solutions that arise exhibit expansion, contraction, and folding in phase space, as expected in chaotic dynamics. Our analysis shows that these features are produced from the interplay of synaptic inhibition with sodium, potassium, and leak currents in a conductance-based framework and provides precise conditions on parameters that ensure that irregular activity will occur. In particular, the temporal details of spiking dynamics must be present for a model to exhibit this irregularity mechanism and must be considered analytically to capture these effects

Irregular activity arises as a natural consequence of synaptic inhibition

Energy Technology Data Exchange (ETDEWEB)

Terman, D., E-mail: terman@math.ohio-state.edu [Department of Mathematics, The Ohio State University, Columbus, Ohio 43210 (United States); Rubin, J. E., E-mail: jonrubin@pitt.edu [Department of Mathematics, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Diekman, C. O., E-mail: diekman@njit.edu [Department of Mathematical Sciences, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)

2013-12-15

Irregular neuronal activity is observed in a variety of brain regions and states. This work illustrates a novel mechanism by which irregular activity naturally emerges in two-cell neuronal networks featuring coupling by synaptic inhibition. We introduce a one-dimensional map that captures the irregular activity occurring in our simulations of conductance-based differential equations and mathematically analyze the instability of fixed points corresponding to synchronous and antiphase spiking for this map. We find that the irregular solutions that arise exhibit expansion, contraction, and folding in phase space, as expected in chaotic dynamics. Our analysis shows that these features are produced from the interplay of synaptic inhibition with sodium, potassium, and leak currents in a conductance-based framework and provides precise conditions on parameters that ensure that irregular activity will occur. In particular, the temporal details of spiking dynamics must be present for a model to exhibit this irregularity mechanism and must be considered analytically to capture these effects.

7 CFR 3565.210 - Maximum interest rate.

Science.gov (United States)

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Maximum interest rate. 3565.210 Section 3565.210... AGRICULTURE GUARANTEED RURAL RENTAL HOUSING PROGRAM Loan Requirements § 3565.210 Maximum interest rate. The interest rate for a guaranteed loan must not exceed the maximum allowable rate specified by the Agency in...

Determination of Measurement Points in Urban Environments for Assessment of Maximum Exposure to EMF Associated with a Base Station

Directory of Open Access Journals (Sweden)

Agostinho Linhares

2014-01-01

Full Text Available A base station (BS antenna operates in accordance with the established exposure limits if the values of electromagnetic fields (EMF measured in points of maximum exposure are below these limits. In the case of BS in open areas, the maximum exposure to EMF probably occurs in the antenna’s boresight direction, from a few tens to a few hundred meters away. This is not a typical scenery for urban environments. However, in the line of sight (LOS situation, the region of maximum exposure can still be analytically estimated with good results. This paper presents a methodology for the choice of measurement points in urban areas in order to assess compliance with the limits for exposure to EMF.

Inhibition by hyperthermia of repair synthesis and chromatin reassembly of ultraviolet-induced damage to DNA

International Nuclear Information System (INIS)

Bodell, W.J.; Cleaver, J.E.; Roti Roti, J.L.

1984-01-01

The authors have investigated the effects of hyperthermia treatment on sequential steps of the repair of UV-induced DNA damage in HeLa cells. DNA repair synthesis was inhibited by 40% after 15 min of hyperthermia treatment at 45 0 C; greater inhibition of repair synthesis occurred with prolonged incubation at 45 0 C. Enzymatic digestion of repair-labeled DNA with Exonuclease III indicated that once DNA repair was initiated, the DNA repair patch was synthesized to completion and that ligation of the DNA repair patch occurred. Thus, the observed inhibition of UV-induced DNA repair synthesis by hyperthermia treatment may be the result of inhibition of enzymes involved in the initiating steps(s) of DNA repair. DNA repair patches synthesized in UV-irradiated cells labeled at 37 0 C with[ 3 H]Thd were 2.2-fold more sensitive to micrococcal nuclease digestion than was parental DNA; if the length of the labeling period was prolonged, the nuclease sensitivity of the repair patch synthesized approached that of the parental DNA. DNA repair patches synthesized at 45 0 C, however, remained sensitive to micrococcal nuclease digestion even after long labeling periods, indicating that heat treatment inhibits the reassembly of the DNA repair patch into nucleosomal structures. 23 references, 3 figures, 2 tables

Odor-evoked inhibition of olfactory sensory neurons drives olfactory perception in Drosophila.

Science.gov (United States)

Cao, Li-Hui; Yang, Dong; Wu, Wei; Zeng, Xiankun; Jing, Bi-Yang; Li, Meng-Tong; Qin, Shanshan; Tang, Chao; Tu, Yuhai; Luo, Dong-Gen

2017-11-07

Inhibitory response occurs throughout the nervous system, including the peripheral olfactory system. While odor-evoked excitation in peripheral olfactory cells is known to encode odor information, the molecular mechanism and functional roles of odor-evoked inhibition remain largely unknown. Here, we examined Drosophila olfactory sensory neurons and found that inhibitory odors triggered outward receptor currents by reducing the constitutive activities of odorant receptors, inhibiting the basal spike firing in olfactory sensory neurons. Remarkably, this odor-evoked inhibition of olfactory sensory neurons elicited by itself a full range of olfactory behaviors from attraction to avoidance, as did odor-evoked olfactory sensory neuron excitation. These results indicated that peripheral inhibition is comparable to excitation in encoding sensory signals rather than merely regulating excitation. Furthermore, we demonstrated that a bidirectional code with both odor-evoked inhibition and excitation in single olfactory sensory neurons increases the odor-coding capacity, providing a means of efficient sensory encoding.

Hydraulic limits on maximum plant transpiration and the emergence of the safety-efficiency trade-off.

Science.gov (United States)

Manzoni, Stefano; Vico, Giulia; Katul, Gabriel; Palmroth, Sari; Jackson, Robert B; Porporato, Amilcare

2013-04-01

Soil and plant hydraulics constrain ecosystem productivity by setting physical limits to water transport and hence carbon uptake by leaves. While more negative xylem water potentials provide a larger driving force for water transport, they also cause cavitation that limits hydraulic conductivity. An optimum balance between driving force and cavitation occurs at intermediate water potentials, thus defining the maximum transpiration rate the xylem can sustain (denoted as E(max)). The presence of this maximum raises the question as to whether plants regulate transpiration through stomata to function near E(max). To address this question, we calculated E(max) across plant functional types and climates using a hydraulic model and a global database of plant hydraulic traits. The predicted E(max) compared well with measured peak transpiration across plant sizes and growth conditions (R = 0.86, P efficiency trade-off in plant xylem. Stomatal conductance allows maximum transpiration rates despite partial cavitation in the xylem thereby suggesting coordination between stomatal regulation and xylem hydraulic characteristics. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

Maximum Stress Estimation Model for Multi-Span Waler Beams with Deflections at the Supports Using Average Strains

Directory of Open Access Journals (Sweden)

Sung Woo Park

2015-03-01

Full Text Available The safety of a multi-span waler beam subjected simultaneously to a distributed load and deflections at its supports can be secured by limiting the maximum stress of the beam to a specific value to prevent the beam from reaching a limit state for failure or collapse. Despite the fact that the vast majority of accidents on construction sites occur at waler beams in retaining wall systems, no safety monitoring model that can consider deflections at the supports of the beam is available. In this paper, a maximum stress estimation model for a waler beam based on average strains measured from vibrating wire strain gauges (VWSGs, the most frequently used sensors in construction field, is presented. The model is derived by defining the relationship between the maximum stress and the average strains measured from VWSGs. In addition to the maximum stress, support reactions, deflections at supports, and the magnitudes of distributed loads for the beam structure can be identified by the estimation model using the average strains. Using simulation tests on two multi-span beams, the performance of the model is evaluated by estimating maximum stress, deflections at supports, support reactions, and the magnitudes of distributed loads.

Effects of synthetic and naturally occurring flavonoids on mitogen-induced proliferation of human peripheral-blood lymphocytes

International Nuclear Information System (INIS)

Hirano, Toshihiko; Oka, Kitaro; Kawashima, Etsuko; Akiba, Mitsuo

1989-01-01

Examination was made of the effects of 17 synthetic and naturally occurring flavonoids on human lymphocyte proliferation in the presence of concanavalin A as a mitogen. Twelve of the flavonoids examined were mono-hydroxy of methoxy derivatives. The mitogen-induced response of lymphocytes was evaluated from the extent of the incorporation of [ 3 H]thymidine into cells in vitro. All the compounds showed inhibitory effects; 4.5-77.7% of [ 3 H] thymidine incorporation was blocked by an 1.0 μg/ml concentration. The viability of lymphocytes before and after treatment, as assessed by a dye exclusion test, indicated no change, and thus the flavonoids may inhibit DNA synthesis. The flavonoids possessing 5-hydroxyl, 5-methoxyl and 6-methoxyl groups, and those with cyclohexyl instead of phenyl substituent (i.e. 2-cyclohexyl-benzopyran-4-one), showed the greatest inhibition. The inhibitory effect of any one of them was less than one half that of prednisolone, but essentially the same or somewhat exceeding that of bredinine of azathioprine. It would thus appear that the well-known anti-inflammatory effects of flavonoids may possibly arise in part from the inhibition of the proliferative response of lymphocytes

Naloxone inhibits superoxide but not enzyme release by human neutrophils

International Nuclear Information System (INIS)

Simpkins, C.; Alailima, S.; Tate, E.

1986-01-01

The release of toxic oxygen metabolites and enzymes by phagocytic cells is thought to play a role in the multisystemic tissue injury of sepsis. Naloxone protects septic animals. We have found that at concentrations administered to animals (10 -7 to 10 -4 M), naloxone inhibited (p 2 - ) by human neutrophils (HN), stimulated with N-formyl methionyl leucyl phenylalanine (FMLP). Naloxone had no effect on cell viability. Maximum inhibition was 65% of the total O 2 - released (13.1 nMoles/8 min/320,000 cells). FMLP-stimulated release of beta-glucoronidase or lysozyme was not altered by naloxone. Naloxone had no effect on the binding of 3 H FMLP to HN. Using 3 H naloxone and various concentrations of unlabeled naloxone higher affinity (K/sub D/ = 12nM) and lower affinity (K/sub D/ = 4.7 x 10 -5 ) binding sites were detected. The K/sub D/ of the low affinity site corresponded to the ED 50 for naloxone inhibition of O 2 - (1 x 10 -5 M). Binding to this low affinity site was decreased by (+) naloxone, beta-endorphin and N acetyl beta-endorphin, but not by leu-enkephalin, thyrotropin releasing factor, prostaglandin D 2 or E 2 . Conclusions: (1) naloxone inhibits FMLP-stimulated O 2 but not enzyme release, (2) this inhibition is not due to alteration of FMLP receptor binding, (3) naloxone may act via a low affinity binding site which is ligand specific, and (4) a higher affinity receptor is present on HN

Experimental and quantum chemical simulations on the corrosion inhibition of mild steel by 3-((5-(3,5-dinitrophenyl)-1,3,4-thiadiazol-2-yl)imino)indolin-2-one

Science.gov (United States)

Al-Azawi, Khalida F.; Mohammed, Iman Mahdi; Al-Baghdadi, Shaimaa B.; Salman, Taghried A.; Issa, Hamsa A.; Al-Amiery, Ahmed A.; Gaaz, Tayser Sumer; Kadhum, Abdul Amir H.

2018-06-01

Iraq has been one of the most extensive oil and natural gas industries in the world. The corrosion of mild steel is costly and insufficiency process. It is responsible for great loss in manufacture and environment. Natural and organic inhibitors have been utilized for a long time to inhibit the corrosion. Selected thiadiazol derivative, namely 3-((5-(3,5-dinitrophenyl)-1,3,4-thiadiazol-2-yl)imino)indolin-2-one (TDIO) was investigated for it inhibitive impacts in 1 M HCl medium on corrosion of mild steel using weight loss and scanning electron microscope techniques. The maximum inhibition efficiency up to 90.7% at the maximum inhibitor concentration 0.5 mM. Surface morphology of results demonstrated that TDIO formed adsorbed film on surface of mild steel in hydrochloric acid solution. Give molecular based clarifications to the inhibitive impacts of the studied. The interactions between mild steel surface and the inhibitor molecules have been undertaken to further corroborate the methodological results.

Andrographolide inhibits arrhythmias and is cardioprotective in rabbits.

Science.gov (United States)

Zeng, Mengliu; Jiang, Wanzhen; Tian, Youjia; Hao, Jie; Cao, Zhenzhen; Liu, Zhipei; Fu, Chen; Zhang, Peihua; Ma, Jihua

2017-09-22

Andrographolide has a protective effect on the cardiovascular system. To study its cardic-electrophysiological effects, action potentials and voltage-gated Na + (I Na ), Ca 2+ (I CaL ), and K + (I K1 , I Kr , I to and I Kur ) currents were recorded using whole-cell patch clamp and current clamp techniques. Additionally, the effects of andrographolide on aconitine-induced arrhythmias were assessed on electrocardiograms in vivo . We found that andrographolide shortened action potential duration and reduced maximum upstroke velocity in rabbit left ventricular and left atrial myocytes. Andrographolide attenuated rate-dependence of action potential duration, and reduced or abolished delayed afterdepolarizations and triggered activities induced by isoproterenol (1 μM) and high calcium ([Ca 2+ ] o =3.6 mM) in left ventricular myocytes. Andrographolide also concentration-dependently inhibited I Na and I CaL , but had no effect on I to , I Kur , I K1 , or I Kr in rabbit left ventricular and left atrial myocytes. Andrographolide treatment increased the time and dosage thresholds of aconitine-induced arrhythmias, and reduced arrhythmia incidence and mortality in rabbits. Our results indicate that andrographolide inhibits cellular arrhythmias (delayed afterdepolarizations and triggered activities) and aconitine-induced arrhythmias in vivo , and these effects result from I Na and I CaL inhibition. Andrographolide may be useful as a class I and IV antiarrhythmic therapeutic.

Inhibition of breathing after surfactant depletion is achieved at a higher arterial PCO2 during ventilation with liquid than with gas

Directory of Open Access Journals (Sweden)

Sindelar Richard

2005-03-01

Full Text Available Abstract Background Inhibition of phrenic nerve activity (PNA can be achieved when alveolar ventilation is adequate and when stretching of lung tissue stimulates mechanoreceptors to inhibit inspiratory activity. During mechanical ventilation under different lung conditions, inhibition of PNA can provide a physiological setting at which ventilatory parameters can be compared and related to arterial blood gases and pH. Objective To study lung mechanics and gas exchange at inhibition of PNA during controlled gas ventilation (GV and during partial liquid ventilation (PLV before and after lung lavage. Methods Nine anaesthetised, mechanically ventilated young cats (age 3.8 ± 0.5 months, weight 2.3 ± 0.1 kg (mean ± SD were studied with stepwise increases in peak inspiratory pressure (PIP until total inhibition of PNA was attained before lavage (with GV and after lavage (GV and PLV. Tidal volume (Vt, PIP, oesophageal pressure and arterial blood gases were measured at inhibition of PNA. One way repeated measures analysis of variance and Student Newman Keuls-tests were used for statistical analysis. Results During GV, inhibition of PNA occurred at lower PIP, transpulmonary pressure (Ptp and Vt before than after lung lavage. After lavage, inhibition of inspiratory activity was achieved at the same PIP, Ptp and Vt during GV and PLV, but occurred at a higher PaCO2 during PLV. After lavage compliance at inhibition was almost the same during GV and PLV and resistance was lower during GV than during PLV. Conclusion Inhibition of inspiratory activity occurs at a higher PaCO2 during PLV than during GV in cats with surfactant-depleted lungs. This could indicate that PLV induces better recruitment of mechanoreceptors than GV.

Trifluoperazine inhibits acetaminophen-induced hepatotoxicity and hepatic reactive nitrogen formation in mice and in freshly isolated hepatocytes

Directory of Open Access Journals (Sweden)

Sudip Banerjee

Full Text Available The hepatotoxicity of acetaminophen (APAP occurs by initial metabolism to N-acetyl-p-benzoquinone imine which depletes GSH and forms APAP-protein adducts. Subsequently, the reactive nitrogen species peroxynitrite is formed from nitric oxide (NO and superoxide leading to 3-nitrotyrosine in proteins. Toxicity occurs with inhibited mitochondrial function. We previously reported that in hepatocytes the nNOS (NOS1 inhibitor NANT inhibited APAP toxicity, reactive nitrogen and oxygen species formation, and mitochondrial dysfunction. In this work we examined the effect of trifluoperazine (TFP, a calmodulin antagonist that inhibits calcium induced nNOS activation, on APAP hepatotoxicity and reactive nitrogen formation in murine hepatocytes and in vivo. In freshly isolated hepatocytes TFP inhibited APAP induced toxicity, reactive nitrogen formation (NO, GSNO, and 3-nitrotyrosine in protein, reactive oxygen formation (superoxide, loss of mitochondrial membrane potential, decreased ATP production, decreased oxygen consumption rate, and increased NADH accumulation. TFP did not alter APAP induced GSH depletion in the hepatocytes or the formation of APAP protein adducts which indicated that reactive metabolite formation was not inhibited. Since we previously reported that TFP inhibits the hepatotoxicity of APAP in mice without altering hepatic APAP-protein adduct formation, we examined the APAP treated mouse livers for evidence of reactive nitrogen formation. 3-Nitrotyrosine in hepatic proteins and GSNO were significantly increased in APAP treated mouse livers and decreased in the livers of mice treated with APAP plus TFP. These data are consistent with a hypothesis that APAP hepatotoxicity occurs with altered calcium metabolism, activation of nNOS leading to increased reactive nitrogen formation, and mitochondrial dysfunction. Keywords: Acetaminophen, Neuronal nitric oxide, Oxidative stress, Mitochondria

MXLKID: a maximum likelihood parameter identifier

International Nuclear Information System (INIS)

Gavel, D.T.

1980-07-01

MXLKID (MaXimum LiKelihood IDentifier) is a computer program designed to identify unknown parameters in a nonlinear dynamic system. Using noisy measurement data from the system, the maximum likelihood identifier computes a likelihood function (LF). Identification of system parameters is accomplished by maximizing the LF with respect to the parameters. The main body of this report briefly summarizes the maximum likelihood technique and gives instructions and examples for running the MXLKID program. MXLKID is implemented LRLTRAN on the CDC7600 computer at LLNL. A detailed mathematical description of the algorithm is given in the appendices. 24 figures, 6 tables

Simultaneous maximum a posteriori longitudinal PET image reconstruction

Science.gov (United States)

Ellis, Sam; Reader, Andrew J.

2017-09-01

Positron emission tomography (PET) is frequently used to monitor functional changes that occur over extended time scales, for example in longitudinal oncology PET protocols that include routine clinical follow-up scans to assess the efficacy of a course of treatment. In these contexts PET datasets are currently reconstructed into images using single-dataset reconstruction methods. Inspired by recently proposed joint PET-MR reconstruction methods, we propose to reconstruct longitudinal datasets simultaneously by using a joint penalty term in order to exploit the high degree of similarity between longitudinal images. We achieved this by penalising voxel-wise differences between pairs of longitudinal PET images in a one-step-late maximum a posteriori (MAP) fashion, resulting in the MAP simultaneous longitudinal reconstruction (SLR) method. The proposed method reduced reconstruction errors and visually improved images relative to standard maximum likelihood expectation-maximisation (ML-EM) in simulated 2D longitudinal brain tumour scans. In reconstructions of split real 3D data with inserted simulated tumours, noise across images reconstructed with MAP-SLR was reduced to levels equivalent to doubling the number of detected counts when using ML-EM. Furthermore, quantification of tumour activities was largely preserved over a variety of longitudinal tumour changes, including changes in size and activity, with larger changes inducing larger biases relative to standard ML-EM reconstructions. Similar improvements were observed for a range of counts levels, demonstrating the robustness of the method when used with a single penalty strength. The results suggest that longitudinal regularisation is a simple but effective method of improving reconstructed PET images without using resolution degrading priors.

Inhibition of bovine kidney alpha-ketoglutarate dehydrogenase complex by reduced nicotinamide adenine dinucleotide in the presence or absence of calcium ion and effect of adenosine 5'-diphosphate on reduced nicotinamide adenine dinucleotide inhibition.

Science.gov (United States)

Lawlis, V B; Roche, T E

1981-04-28

Micromolar Ca2+ markedly reduces NADH inhibition of bovine kidney alpha-ketoglutarate dehydrogenase complex [Lawlis, V. B., & Roche, T. E. (1980) Mol. Cell. Biochem. 32, 147-152]. Product inhibition patterns from initial velocity studies conducted at less than 10(-9) M or at 1.5 X 10(-5) M Ca2+ with NAD+, CoA, or alpha-ketoglutarate as the variable substrate showed that NADH was a noncompetitive inhibitor with respect to each of these substrates, except at high NAD+ concentrations, where reciprocal plots were nonlinear and the inhibition pattern for NADH vs. NAD+ changed from a noncompetitive to a competitive pattern. From slope and intercept replots, 2-fold to 12-fold higher inhibition constants were estimated for inhibition by NADH vs. the various substrates in the presence of 1.5 X 10(-5) M Ca2+ than for inhibition at less than 10(-9) M Ca2+. These inhibition patterns and the lack of an effect of Ca2+ on the inhibition of the dihydrolipoyl dehydrogenase component suggested that Ca2+-modulated NADH inhibition occurs at an allosteric site with competitive binding at the site by high levels of NAD+. Decarboxylation of alpha-keto[1-14C]glutarate by the resolved alpha-ketoglutarate dehydrogenase component was investigated in the presence of 5.0 mM glyoxylate which served as an efficient acceptor. NADH (0.2 mM) or 1.0 mM ATP inhibited the partial reaction whereas 15 muM Ca2+, 1.0 mM ADP, or 10 mM NAD+ stimulated the partial reaction and reduced NADH inhibition of this reaction. Thus these effectors alter the activity of the alpha-ketoglutarate dehydrogenase complex by binding at allosteric sites on the alpha-ketoglutarate dehydrogenase component. Inhibition by NADH over a wide range of NADH/NAD+ ratios was measured under conditions in which the level of alpha-ketoglutarate was adjusted to give matching control activities at less than 10(-9) M Ca2+ or 1.5 X 10(-5) M Ca2+ in either the presence or the absence of 1.6 mM ADP. These studies establish that both Ca2+ and ADP

Research on inhibition of corneal neovascularization

Directory of Open Access Journals (Sweden)

Zhang-Hui Yang

2015-12-01

Full Text Available Corneal transparency is the basis of the normal physiological functions.However, corneal neovascularization(CNVmay occur in the infection, mechanical and chemical injury or under other pathological conditions,which make the cornea lose original transparency and severe visual impairment. In recent years, along with the development of immunology, molecular biology, biochemistry and other disciplines, there is more in-depth understanding on the CNV, and clinical treatment of CNV has made new breakthroughs. This article provides an overview of the inhibition of CNV.

GPR56/ADGRG1 Inhibits Mesenchymal Differentiation and Radioresistance in Glioblastoma

NARCIS (Netherlands)

Moreno, Marta; Pedrosa, Leire; Pare, Laia; Pineda, Estela; Bejarano, Leire; Martinez, Josefina; Balasubramaniyan, Veerakumar; Ezhilarasan, Ravesanker; Kallarackal, Naveen; Kim, Sung-Hak; Wang, Jia; Audia, Alessandra; Conroy, Siobhan; Marin, Mercedes; Ribalta, Teresa; Pujol, Teresa; Herreros, Antoni; Tortosa, Avelina; Mira, Helena; Alonso, Marta M.; Gomez-Manzano, Candelaria; Graus, Francesc; Sulman, Erik P.; Piao, Xianhua; Nakano, Ichiro; Prat, Aleix; Bhat, Krishna P.; de la Iglesia, Nuria

2017-01-01

A mesenchymal transition occurs both during the natural evolution of glioblastoma (GBM) and in response to therapy. Here, we report that the adhesion G-protein-coupled receptor, GPR56/ADGRG1, inhibits GBM mesenchymal differentiation and radioresistance. GPR56 is enriched in proneural and

Hypersensitivity to contact inhibition provides a clue to cancer resistance of naked mole-rat.

Science.gov (United States)

Seluanov, Andrei; Hine, Christopher; Azpurua, Jorge; Feigenson, Marina; Bozzella, Michael; Mao, Zhiyong; Catania, Kenneth C; Gorbunova, Vera

2009-11-17

The naked mole-rat is the longest living rodent with a maximum lifespan exceeding 28 years. In addition to its longevity, naked mole-rats have an extraordinary resistance to cancer as tumors have never been observed in these rodents. Furthermore, we show that a combination of activated Ras and SV40 LT fails to induce robust anchorage-independent growth in naked mole-rat cells, while it readily transforms mouse fibroblasts. The mechanisms responsible for the cancer resistance of naked mole-rats were unknown. Here we show that naked mole-rat fibroblasts display hypersensitivity to contact inhibition, a phenomenon we termed "early contact inhibition." Contact inhibition is a key anticancer mechanism that arrests cell division when cells reach a high density. In cell culture, naked mole-rat fibroblasts arrest at a much lower density than those from a mouse. We demonstrate that early contact inhibition requires the activity of p53 and pRb tumor suppressor pathways. Inactivation of both p53 and pRb attenuates early contact inhibition. Contact inhibition in human and mouse is triggered by the induction of p27(Kip1). In contrast, early contact inhibition in naked mole-rat is associated with the induction of p16(Ink4a). Furthermore, we show that the roles of p16(Ink4a) and p27(Kip1) in the control of contact inhibition became temporally separated in this species: the early contact inhibition is controlled by p16(Ink4a), and regular contact inhibition is controlled by p27(Kip1). We propose that the additional layer of protection conferred by two-tiered contact inhibition contributes to the remarkable tumor resistance of the naked mole-rat.

Inhibition of copper corrosion in sodium chloride solution by the self-assembled monolayer of sodium diethyldithiocarbamate

Energy Technology Data Exchange (ETDEWEB)

Liao, Q.Q., E-mail: liaoqq1971@yahoo.com.c [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Yue, Z.W.; Yang, D. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Z.H. [Department of Chemistry, Tongji University, Shanghai 200092 (China); Li, Z.H. [Department of Chemistry, Fudan University, Shanghai 200433 (China); Ge, H.H. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Y.J. [Department of Chemistry, Tongji University, Shanghai 200092 (China)

2011-05-15

Research highlights: DDTC is of low toxicity. DDTC SAM had good corrosion inhibition effects on copper in 3% NaCl solution. DDTC SAM was chemisorbed on copper surface by its S atoms. - Abstract: Sodium diethyldithiocarbamate (DDTC) self-assembled monolayer (SAM) on copper surface has been investigated by SERS and EDS and the results show that DDTC SAM is chemisorbed on copper surface by its S atoms with tilted orientation. Corrosion inhibition ability of DDTC SAM was measured in 3% NaCl solution using electrochemical methods. The impedance results indicate that the maximum inhibition efficiency of DDTC SAM can reach 99%. Quantum chemical calculations show that DDTC has relatively small {Delta}E between HOMO and LUMO and large negative charge in its two sulfur atoms, which facilitates the formation of a DDTC SAM on copper surface.

Comparison of inhibition capability of scutellarein and scutellarin towards important liver UDP-glucuronosyltransferase (UGT) isoforms.

Science.gov (United States)

Ma, Guang-You; Cao, Yun-Feng; Hu, Cui-Min; Fang, Zhong-Ze; Sun, Xiao-Yu; Hong, Mo; Zhu, Zhi-Tu

2014-03-01

Scutellarin is an important bioactive flavonoid extracted from Erigeron breviscapus (Vant.) Hand-Mazz, and scutellarein is the corresponding aglycone of scutellarin. The present study aims to compare the inhibition potential of scutellarin and scutellarein towards several important UDP-glucuronosyltransferase (UGT) isoforms, including UGT1A1, UGT1A6, UGT1A9 and UGT2B7. It was demonstrated that scutellarein exerted stronger inhibition towards the tested UGT isoforms than scutellarin. Furthermore, the inhibition kinetic type and parameters (Ki ) were determined for the scutellarein's inhibition towards these UGT isoforms. Competitive inhibition of scutellarein towards all these UGT isoforms was demonstrated, and the Ki values were calculated to be 0.02, 5.0, 5.8 and 35.9 μM for UGT1A1, 1A6, 1A9 and 2B7, respectively. Using in vivo maximum plasma concentration of scutellarein in rat, the in vitro-in vivo extrapolation was performed to predict in vivo situation, indicating the most possible in vivo adverse effects due to the inhibition of scutellarein towards UGT1A1. All these results remind us to monitor the utilization of scutellarin and scutellarein, and the herbs containing these two components. Copyright © 2013 John Wiley & Sons, Ltd.

Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

Energy Technology Data Exchange (ETDEWEB)

Lin Daohui [Department of Environmental Science, Zhejiang University, Hangzhou 310028 (China); Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States); Xing Baoshan [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Stockbridge Hall, Amherst, MA 01003 (United States)], E-mail: bx@pssci.umass.edu

2007-11-15

Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC{sub 50}) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth.

Phytotoxicity of nanoparticles: Inhibition of seed germination and root growth

International Nuclear Information System (INIS)

Lin Daohui; Xing Baoshan

2007-01-01

Plants need to be included to develop a comprehensive toxicity profile for nanoparticles. Effects of five types of nanoparticles (multi-walled carbon nanotube, aluminum, alumina, zinc, and zinc oxide) on seed germination and root growth of six higher plant species (radish, rape, ryegrass, lettuce, corn, and cucumber) were investigated. Seed germination was not affected except for the inhibition of nanoscale zinc (nano-Zn) on ryegrass and zinc oxide (nano-ZnO) on corn at 2000 mg/L. Inhibition on root growth varied greatly among nanoparticles and plants. Suspensions of 2000 mg/L nano-Zn or nano-ZnO practically terminated root elongation of the tested plant species. Fifty percent inhibitory concentrations (IC 50 ) of nano-Zn and nano-ZnO were estimated to be near 50 mg/L for radish, and about 20 mg/L for rape and ryegrass. The inhibition occurred during the seed incubation process rather than seed soaking stage. These results are significant in terms of use and disposal of engineered nanoparticles. - Engineered nanoparticles can inhibit the seed germination and root growth

Inhibition of DNA-double strand break repair by antimony compounds

International Nuclear Information System (INIS)

Takahashi, Sentaro; Sato, Hiroshi; Kubota, Yoshihisa; Utsumi, Hiroshi; Bedford, Joel S.; Okayasu, Ryuichi

2002-01-01

DNA double strand breaks (DSBs), induced by γ-irradiation in Chinese hamster ovary cells, were used to examine whether antimony compounds affect the repair of DNA damage. The cells were first incubated with antimony trichloride or antimony potassium tartrate (both Sb(III)) for 2 h, and then irradiated with γ-rays at a dose of 40 Gy. The DNA DSB was quantified with pulsed field gel electrophoresis immediately after irradiation (non-repair group) as well as at 30 min post-irradiation (repair group). The degree of repair inhibition was determined by the differences in the amount of DNA DSB between non-repair and repair groups. Both antimony compounds inhibited repair of DNA DSB in a dose dependent manner. In trichloride, 0.2 mM antimony significantly inhibited the rejoining of DSB, while 0.4 mM was necessary in potassium antimony tartrate. The mean lethal doses, D 0 , for the treatment with antimony trichloride and antimony potassium tartrate, were approximately 0.21 and 0.12 mM, respectively. This indicates that the repair inhibition by antimony trichloride occurred in the dose range near D 0 , but the antimony potassium tartrate inhibited the repair at doses where most cells lost their proliferating ability. This is the first report to indicate that antimony compounds may inhibit the repair of radiation-induced DNA DSB

78 FR 9845 - Minimum and Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for a Violation of...

Science.gov (United States)

2013-02-12

... maximum penalty amount of $75,000 for each violation, except that if the violation results in death... the maximum civil penalty for a violation is $175,000 if the violation results in death, serious... Penalties for a Violation of the Hazardous Materials Transportation Laws or Regulations, Orders, Special...

Hili Inhibits HIV Replication in Activated T Cells.

Science.gov (United States)

Peterlin, B Matija; Liu, Pingyang; Wang, Xiaoyun; Cary, Daniele; Shao, Wei; Leoz, Marie; Hong, Tian; Pan, Tao; Fujinaga, Koh

2017-06-01

P-element-induced wimpy-like (Piwil) proteins restrict the replication of mobile genetic elements in the germ line. They are also expressed in many transformed cell lines. In this study, we discovered that the human Piwil 2 (Hili) protein can also inhibit HIV replication, especially in activated CD4 + T cells that are the preferred target cells for this virus in the infected host. Although resting cells did not express Hili, its expression was rapidly induced following T cell activation. In these cells and transformed cell lines, depletion of Hili increased levels of viral proteins and new viral particles. Further studies revealed that Hili binds to tRNA. Some of the tRNAs represent rare tRNA species, whose codons are overrepresented in the viral genome. Targeting tRNA Arg (UCU) with an antisense oligonucleotide replicated effects of Hili and also inhibited HIV replication. Finally, Hili also inhibited the retrotransposition of the endogenous intracysternal A particle (IAP) by a similar mechanism. Thus, Hili joins a list of host proteins that inhibit the replication of HIV and other mobile genetic elements. IMPORTANCE Piwil proteins inhibit the movement of mobile genetic elements in the germ line. In their absence, sperm does not form and male mice are sterile. This inhibition is thought to occur via small Piwi-interacting RNAs (piRNAs). However, in some species and in human somatic cells, Piwil proteins bind primarily to tRNA. In this report, we demonstrate that human Piwil proteins, especially Hili, not only bind to select tRNA species, including rare tRNAs, but also inhibit HIV replication. Importantly, T cell activation induces the expression of Hili in CD4 + T cells. Since Hili also inhibited the movement of an endogenous retrovirus (IAP), our finding shed new light on this intracellular resistance to exogenous and endogenous retroviruses as well as other mobile genetic elements. Copyright © 2017 American Society for Microbiology.

Resveratrol induces autophagy by directly inhibiting mTOR through ATP competition

Science.gov (United States)

Park, Dohyun; Jeong, Heeyoon; Lee, Mi Nam; Koh, Ara; Kwon, Ohman; Yang, Yong Ryoul; Noh, Jungeun; Suh, Pann-Ghill; Park, Hwangseo; Ryu, Sung Ho

2016-01-01

Resveratrol (RSV) is a natural polyphenol that has a beneficial effect on health, and resveratrol-induced autophagy has been suggested to be a key process in mediating many beneficial effects of resveratrol, such as reduction of inflammation and induction of cancer cell death. Although various resveratrol targets have been suggested, the molecule that mediates resveratrol-induced autophagy remains unknown. Here, we demonstrate that resveratrol induces autophagy by directly inhibiting the mTOR-ULK1 pathway. We found that inhibition of mTOR activity and presence of ULK1 are required for autophagy induction by resveratrol. In line with this mTOR dependency, we found that resveratrol suppresses the viability of MCF7 cells but not of SW620 cells, which are mTOR inhibitor sensitive and insensitive cancer cells, respectively. We also found that resveratrol-induced cancer cell suppression occurred ULK1 dependently. For the mechanism of action of resveratrol on mTOR inhibition, we demonstrate that resveratrol directly inhibits mTOR. We found that resveratrol inhibits mTOR by docking onto the ATP-binding pocket of mTOR (i.e., it competes with ATP). We propose mTOR as a novel direct target of resveratrol, and inhibition of mTOR is necessary for autophagy induction. PMID:26902888

Inhibitive effect of a naturally-occurring substance, tobacco, on the dissolution of mild steel in hydrochloric acid

Energy Technology Data Exchange (ETDEWEB)

Srivastava, K; Srivastava, P

1980-12-01

A number of naturally-occurring substances has been found to be effective inhibitors for the dissolution of mild steel in hydrochloric acid. The alkaloids nicotine and papaverine, contained in natural products such as tobacco leaves and black pepper, have proved themselves as excellent inhibitors. Considering the low cost of tobacco leaves, detailed studies were made with these, and they have been found to form an effective inhibitor under all practical conditions. Adsorption studies based on weight-loss measurements showed that adsorption of inhibitor obeys Freundlich's adsorption isoth

TNF-α inhibits trophoblast integration into endothelial cellular networks.

Science.gov (United States)

Xu, B; Nakhla, S; Makris, A; Hennessy, A

2011-03-01

Preeclampsia has been linked to shallow trophoblast invasion and failure of uterine spiral artery transformation. Interaction between trophoblast cells and maternal uterine endothelium is critically important for this remodelling. The aim of our study was to investigate the effect of TNF-α on the interactions of trophoblast-derived JEG-3 cells into capillary-like cellular networks. We have employed an in vitro trophoblast-endothelial cell co-culture model to quantify trophoblast integration into endothelial cellular networks and to investigate the effects of TNF-α. Controlled co-cultures were also treated with anti-TNF-α antibody (5 μg/ml) to specifically block the effect of TNF-α. The invasion was evaluated by performing quantitative PCR (Q-PCR) to analyse gene expression of matrix metalloproteinases-2 (MMP-2), MMP-9, tissue inhibitor of matrix metalloproteinase (TIMP)-1, integrins (α(1)β(1) and α(6)β(4)), plasminogen activator inhibitor (PAI)-1, E-cadherin and VE-cadherin. JEG-3 cell integration into endothelial networks was significantly inhibited by exogenous TNF-α. The inhibition was observed in the range of 0.2-5 ng/ml, to a maximum 56% inhibition at the highest concentration. This inhibition was reversed by anti-TNF-α antibody. Q-PCR analysis showed that mRNA expression of integrins α(1)β(1) and MMP-2 was significantly decreased. VE-cadherin mRNA expression was significantly up-regulated (32-80%, p integration into maternal endothelial cellular networks, and this process involves the inhibition of MMP-2 and a failure of integrins switch from α(6)β(4) to α(1)β(1.) These molecular correlations reflect the changes identified in human preeclampsia. Copyright © 2011 Elsevier Ltd. All rights reserved.

Sites of inhibition of mitochondrial electron transport in macrophage-injured neoplastic cells.

Science.gov (United States)

Granger, D L; Lehninger, A L

1982-11-01

Previous work has shown that injury of neoplastic cells by cytotoxic macrophages (CM) in cell culture is accompanied by inhibition of mitochondrial respiration. We have investigated the nature of this inhibition by studying mitochondrial respiration in CM-injured leukemia L1210 cells permeabilized with digitonin. CM-induced injury affects the mitochondrial respiratory chain proper. Complex I (NADH-coenzyme Q reductase) and complex II (succinate-coenzyme Q reductase) are markedly inhibited. In addition a minor inhibition of cytochrome oxidase was found. Electron transport from alpha-glycerophosphate through the respiratory chain to oxygen is unaffected and permeabilized CM-injured L1210 cells oxidizing this substrate exhibit acceptor control. However, glycerophosphate shuttle activity was found not to occur within CM-injured or uninjured L1210 cells in culture hence, alpha-glycerophosphate is apparently unavailable for mitochondrial oxidation in the intact cell. It is concluded that the failure of respiration of intact neoplastic cells injured by CM is caused by the nearly complete inhibition of complexes I and II of the mitochondrial electron transport chain. The time courses of CM-induced electron transport inhibition and arrest of L1210 cell division are examined and the possible relationship between these phenomena is discussed.

Performance analysis and comparison of an Atkinson cycle coupled to variable temperature heat reservoirs under maximum power and maximum power density conditions

International Nuclear Information System (INIS)

Wang, P.-Y.; Hou, S.-S.

2005-01-01

In this paper, performance analysis and comparison based on the maximum power and maximum power density conditions have been conducted for an Atkinson cycle coupled to variable temperature heat reservoirs. The Atkinson cycle is internally reversible but externally irreversible, since there is external irreversibility of heat transfer during the processes of constant volume heat addition and constant pressure heat rejection. This study is based purely on classical thermodynamic analysis methodology. It should be especially emphasized that all the results and conclusions are based on classical thermodynamics. The power density, defined as the ratio of power output to maximum specific volume in the cycle, is taken as the optimization objective because it considers the effects of engine size as related to investment cost. The results show that an engine design based on maximum power density with constant effectiveness of the hot and cold side heat exchangers or constant inlet temperature ratio of the heat reservoirs will have smaller size but higher efficiency, compression ratio, expansion ratio and maximum temperature than one based on maximum power. From the view points of engine size and thermal efficiency, an engine design based on maximum power density is better than one based on maximum power conditions. However, due to the higher compression ratio and maximum temperature in the cycle, an engine design based on maximum power density conditions requires tougher materials for engine construction than one based on maximum power conditions

Long-range tactile masking occurs in the postural body schema.

Science.gov (United States)

D'Amour, Sarah; Harris, Laurence R

2016-02-01

Long-range tactile masking has been reported between mirror symmetric body locations. This suggests a general principle of contralateral inhibition between corresponding points on each side of the body that may serve to enhance distinguishing touches on the two halves of the body. Do such effects occur before or after posture is added to the body schema? Here, we address this question by exploring the effect of arm position on long-range tactile masking. The influence of arm position was investigated using different positions of both the test and masking arms. Tactile sensitivity was measured on one forearm, while vibrotactile-masking stimulation was applied to the opposite arm or to a control site on the shoulder. No difference was found in sensitivity when test arm position was varied. Physical contact between the arms significantly increased the effectiveness of a masking stimulus applied to the other arm. Long-range masking between the arms was strongest when the arms were held parallel to each other and was abolished if the position of either the test arm or the masking arm was moved from this position. Modulation of the effectiveness of masking by the position of both the test and masking arms suggests that these effects occur after posture information is added to the body's representation in the brain.

Anxiety and retrieval inhibition: support for an enhanced inhibition account.

Science.gov (United States)

Nuñez, Mia; Gregory, Josh; Zinbarg, Richard E

2017-02-01

Retrieval inhibition of negative associations is important for exposure therapy for anxiety, but the relationship between memory inhibition and anxiety is not well understood-anxiety could either be associated with enhanced or deficient inhibition. The present study tested these two competing hypotheses by measuring retrieval inhibition of negative stimuli by related neutral stimuli. Non-clinically anxious undergraduates completed measures of trait and state anxiety and completed a retrieval induced forgetting task. Adaptive forgetting varied with state anxiety. Low levels of state anxiety were associated with no evidence for retrieval inhibition for either threatening or non-threatening categories. Participants in the middle tertile of state anxiety scores exhibited retrieval inhibition for non-threatening categories but not for threatening categories. Participants in the highest tertile of state anxiety, however, exhibited retrieval inhibition for both threatening and non-threatening categories with the magnitude of retrieval inhibition being greater for threatening than non-threatening categories. The data are in line with the avoidance aspect of the vigilance-avoidance theory of anxiety and inhibition. Implications for cognitive behavioural therapy practices are discussed.

Occlusal splint versus modified nociceptive trigeminal inhibition splint in bruxism therapy: a randomized, controlled trial using surface electromyography.

Science.gov (United States)

Dalewski, B; Chruściel-Nogalska, M; Frączak, B

2015-12-01

An occlusal splint and a modified nociceptive trigeminal inhibition splint (AMPS, anterior deprogrammer, Kois deprogrammer, Lucia jig, etc.) are commonly and quite frequently used in the treatment of masticatory muscle disorders, although their sustainable and long-lasting effect on these muscles' function is still not very well known. Results of scant surface electromyography studies in patients with temporomandibular disorders have been contradictory. The aim of this study was to evaluate both devices in bruxism therapy; EMG activity levels during postural activity and maximum voluntary contraction of the superficial temporal and masseter muscles were compared before and after 30 days of treatment. Surface electromyography of the examined muscles was performed in two groups of bruxers (15 patients each). Patients in the first group used occlusal splints, while those in the second used modified nociceptive trigeminal inhibition splints. The trial was randomized, controlled and semi-blind. Neither device affected the asymmetry index or postural activity/maximum voluntary contraction ratio after 1 month of treatment. Neither the occlusal nor the nociceptive trigeminal inhibition splint showed any significant influence on the examined muscles. Different scientific methods should be considered in clinical applications that require either direct influence on the muscles' bioelectrical activity or a quantitative measurement of the treatment quality. © 2015 Australian Dental Association.

A Kinetic Modelling of Enzyme Inhibitions in the Central Metabolism of Yeast Cells

Science.gov (United States)

Kasbawati; Kalondeng, A.; Aris, N.; Erawaty, N.; Azis, M. I.

2018-03-01

Metabolic regulation plays an important role in the metabolic engineering of a cellular process. It is conducted to improve the productivity of a microbial process by identifying the important regulatory nodes of a metabolic pathway such as fermentation pathway. Regulation of enzymes involved in a particular pathway can be held to improve the productivity of the system. In the central metabolism of yeast cell, some enzymes are known as regulating enzymes that can be inhibited to increase the production of ethanol. In this research we study the kinetic modelling of the enzymes in the central pathway of yeast metabolism by taking into consideration the enzyme inhibition effects to the ethanol production. The existence of positive steady state solution and the stability of the system are also analysed to study the property and dynamical behaviour of the system. One stable steady state of the system is produced if some conditions are fulfilled. The conditions concern to the restriction of the maximum reactions of the enzymes in the pyruvate and acetaldehyde branch points. There exists a certain time of fermentation reaction at which a maximum and a minimum ethanol productions are attained after regulating the system. Optimal ethanol concentration is also produced for a certain initial concentration of inhibitor.

Anaerobic co-digestion of waste activated sludge and greasy sludge from flotation process: Batch versus CSTR experiments to investigate optimal design

OpenAIRE

Girault , R.; Bridoux , G.; Nauleau , F.; Poullain , C.; Buffet , J.; Peu , P.; Sadowski , A.G.; Béline , F.

2012-01-01

In this study, the maximum ratio of greasy sluvdge to incorporate with waste activated sludge was investigated in batch and CSTR experiments. In batch experiments, inhibition occurred with a greasy sludge ratio of more than 20-30% of the feed COD. In CSTR experiments, the optimal greasy sludge ratio was 60% of the feed COD and inhibition occurred above a ratio of 80%. Hence, batch experiments can predict the CSTR yield when the degradation phenomenon are additive but cannot be used to determi...

Rapid redistribution and inhibition of renal sodium transporters during acute pressure natriuresis

DEFF Research Database (Denmark)

Zhang, Y; Mircheff, A K; Hensley, C B

1996-01-01

and basolateral Na+ pumps to internal membranes. Arterial pressure was increased 50 mmHg by constricting various arteries. We also tested whether transporter internalization occurred when PT Na+ reabsorption was inhibited with the carbonic anhydrase inhibitor benzolamide. Five minutes after initiating either...

Naloxone inhibits superoxide but not enzyme release by human neutrophils

Energy Technology Data Exchange (ETDEWEB)

Simpkins, C.; Alailima, S.; Tate, E.

1986-03-01

The release of toxic oxygen metabolites and enzymes by phagocytic cells is thought to play a role in the multisystemic tissue injury of sepsis. Naloxone protects septic animals. We have found that at concentrations administered to animals (10/sup -7/ to 10/sup -4/M), naloxone inhibited (p < .001) the release of superoxide (O/sub 2//sup -/) by human neutrophils (HN), stimulated with N-formyl methionyl leucyl phenylalanine (FMLP). Naloxone had no effect on cell viability. Maximum inhibition was 65% of the total O/sub 2//sup -/ released (13.1 nMoles/8 min/320,000 cells). FMLP-stimulated release of beta-glucoronidase or lysozyme was not altered by naloxone. Naloxone had no effect on the binding of /sup 3/H FMLP to HN. Using /sup 3/H naloxone and various concentrations of unlabeled naloxone higher affinity (K/sub D/ = 12nM) and lower affinity (K/sub D/ = 4.7 x 10/sup -5/) binding sites were detected. The K/sub D/ of the low affinity site corresponded to the ED/sub 50/ for naloxone inhibition of O/sub 2//sup -/ (1 x 10/sup -5/M). Binding to this low affinity site was decreased by (+) naloxone, beta-endorphin and N acetyl beta-endorphin, but not by leu-enkephalin, thyrotropin releasing factor, prostaglandin D/sub 2/ or E/sub 2/. Conclusions: (1) naloxone inhibits FMLP-stimulated O/sub 2/ but not enzyme release, (2) this inhibition is not due to alteration of FMLP receptor binding, (3) naloxone may act via a low affinity binding site which is ligand specific, and (4) a higher affinity receptor is present on HN.

Neurobiology of mammalian olfactory learning that occurs during sensitive periods

Directory of Open Access Journals (Sweden)

Hideto KABA

2010-12-01

Full Text Available This review examines the organizational principles underlying olfactory learning in three specialized contexts that occur during sensitive periods of enhanced neural plasticity and emphasizes some of their common features. All three forms of olfactory learning are associated with neural changes in the olfactory bulb (OB at the first stage of sensory processing. These changes require the association of the olfactory and somatosensory signals in the OB. They all depend on somatosensory stimulation-induced release of noradrenaline that induces structural and functional changes at mitral-granule cell reciprocal synapses in the OB, resulting in increases in inhibitory transmission. In the accessory olfactory bulb, this represents the enhanced self-inhibition of mitral cells, which selectively disrupts the transmission of the mating male’s pregnancy-blocking signal at this level. In contrast, an extensive network of secondary dendrites of mitral cells in the main olfactory bulb probably results in a sharpening of the odor-induced pattern of activity, due to increases in lateral inhibition, leading to offspring recognition in sheep and neonatal learning in rats and rabbits. These findings show that inhibitory interneurons play a critical role in olfactory learning. Further work on how these neurons shape olfactory circuit function could provide important clues to understand memory functions of interneurons in other systems. Moreover, recent research has suggested that three forms of olfactory learning are controlled by synergistic, redundant, and distributed neural mechanisms. This has general implications regarding the mechanisms that may contribute to the robustness of memories [Current Zoology 56 (6: 819–833, 2010].

LCLS Maximum Credible Beam Power

International Nuclear Information System (INIS)

Clendenin, J.

2005-01-01

The maximum credible beam power is defined as the highest credible average beam power that the accelerator can deliver to the point in question, given the laws of physics, the beam line design, and assuming all protection devices have failed. For a new accelerator project, the official maximum credible beam power is determined by project staff in consultation with the Radiation Physics Department, after examining the arguments and evidence presented by the appropriate accelerator physicist(s) and beam line engineers. The definitive parameter becomes part of the project's safety envelope. This technical note will first review the studies that were done for the Gun Test Facility (GTF) at SSRL, where a photoinjector similar to the one proposed for the LCLS is being tested. In Section 3 the maximum charge out of the gun for a single rf pulse is calculated. In Section 4, PARMELA simulations are used to track the beam from the gun to the end of the photoinjector. Finally in Section 5 the beam through the matching section and injected into Linac-1 is discussed

Inhibition of E. coli P-enolpyruvate carboxylase by P-enol-3-bromopyruvate

International Nuclear Information System (INIS)

Asem, K.; Smith, T.E.

1986-01-01

The generality of the mechanism based inhibition of P-enolpyruvate carboxylases (PEPCase) by P-enol-3-bromopyruvate (BrPEP) was tested by measuring its effects on the allosterically regulated enzyme from E. coli. In the presence of 1mM Mn 2+ , BrPEP appears to be a competitive inhibitor (K/sub i/ = 0.0087mM) of PEPCase. Incubation of 0.005mM PEPCase with 0.5mM (or 1.0mM)BrPEP along with H 14 CO 3 - and Mn 2+ , yielded, upon reduction with NaBH 4 , a protein containing radioactivity in an amount approximately proportional to that expected from the loss of catalytic activity. At both a 25- and a 50-fold excess (0.5mM and 1.0mM, respectively) of BrPEP to PEPCase subunits, first order loss of activity occurred with k values of 5.24 x 10 -3 min -1 and 1.03 x 10 -2 min -1 , respectively. At the lower concentration of BrPEP the inactivation process appeared to be reversible after 40 min with no further inhibition occurring even up to two hours of incubation. At the higher concentration of BrPEP, the rate of inhibition slowed dramatically after 50 min and appeared insignificant over the next hour. These data suggest that BrPEP irreversibly inactivates the E. coli PEP carboxylase, but that there may be considerable dissociation of the product, Br-oxaloacetate, before irreversible binding occurs, and that the reduced rate of inactivation may be due to depletion of BrPEP

Influence of the composition of radionuclide mixtures on the maximum permissible concentration

International Nuclear Information System (INIS)

Schillinger, K.; Schuricht, V.

1975-08-01

By dividing radionuclides according to their formation mechanisms it is possible to assess the influence of separate partial mixtures on the maximum permissible concentration (MPC) of the total mixture without knowing exactly their contribution to the total activity. Calculations showed that the MPC of a total mixture of unsoluble radionuclides, which may occur in all fields of peaceful uses of nuclear energy, depends on the gastrointestinal tract as the critical organ and on the composition of the fission product mixture. The influence of fractionation on the MPC can be reglected in such a case, whereas in case of soluble radionuclides this is not possible

Evaluation of Plants and Weeds Extract on the Corrosion Inhibition of Mild Steel in Sulphuric Acid

Directory of Open Access Journals (Sweden)

Abida Begum

2011-01-01

Full Text Available Experiments were performed in order to determine the inhibitive effects of extracts of plants and weeds namely Parthenium hysterophorus, Dathura stromonium, Azadirachta indica, Helianthus annuus leaves extract for mild steel in sulphuric acid by using weight loss and thermometric technique. Results demonstrated that, all the experimental inhibitors show an adsorption on steel surface according to Langmuir’s isotherm. The inhibition efficiency increased with increase in the concentration of all tested inhibitors to attain a maximum value at 1.0%. Free energy values for adsorption process show that the process is spontaneous. The kinetic treatment of the results shows first order kinetics.

A comparative study of leaves extracts for corrosion inhibition effect on aluminium alloy in alkaline medium

Directory of Open Access Journals (Sweden)

Namrata Chaubey

2017-12-01

Full Text Available This paper deals with the comparative inhibition study of some plants leaves extract namely Cannabis sativa (CS, Rauwolfia serpentina (RS, Cymbopogon citratus (CC, Annona squamosa (AS and Adhatoda vasica (AV on the corrosion of aluminium alloy (AA in 1 M NaOH. The corrosion tests were performance by using gravimetric, electrochemical impedance spectroscopy (EIS, potentiodynamic polarization and linear polarization resistance (LPR techniques. RS showed maximum inhibition efficiency (η%, 97% at 0.2 g L−1. Potentiodynamic polarization curves justified that all the inhibitors are mixed-type. Surface morphology of AA is carried by scanning electron microscopy (SEM and atomic force microscopy (AFM.

Gradient microfluidics enables rapid bacterial growth inhibition testing.

Science.gov (United States)

Li, Bing; Qiu, Yong; Glidle, Andrew; McIlvenna, David; Luo, Qian; Cooper, Jon; Shi, Han-Chang; Yin, Huabing

2014-03-18

Bacterial growth inhibition tests have become a standard measure of the adverse effects of inhibitors for a wide range of applications, such as toxicity testing in the medical and environmental sciences. However, conventional well-plate formats for these tests are laborious and provide limited information (often being restricted to an end-point assay). In this study, we have developed a microfluidic system that enables fast quantification of the effect of an inhibitor on bacteria growth and survival, within a single experiment. This format offers a unique combination of advantages, including long-term continuous flow culture, generation of concentration gradients, and single cell morphology tracking. Using Escherichia coli and the inhibitor amoxicillin as one model system, we show excellent agreement between an on-chip single cell-based assay and conventional methods to obtain quantitative measures of antibiotic inhibition (for example, minimum inhibition concentration). Furthermore, we show that our methods can provide additional information, over and above that of the standard well-plate assay, including kinetic information on growth inhibition and measurements of bacterial morphological dynamics over a wide range of inhibitor concentrations. Finally, using a second model system, we show that this chip-based systems does not require the bacteria to be labeled and is well suited for the study of naturally occurring species. We illustrate this using Nitrosomonas europaea, an environmentally important bacteria, and show that the chip system can lead to a significant reduction in the period required for growth and inhibition measurements (<4 days, compared to weeks in a culture flask).

Temporal and spatial variation of maximum wind speed days during the past 20 years in major cities of Xinjiang

Science.gov (United States)

Baidourela, Aliya; Jing, Zhen; Zhayimu, Kahaer; Abulaiti, Adili; Ubuli, Hakezi

2018-04-01

Wind erosion and sandstorms occur in the neighborhood of exposed dust sources. Wind erosion and desertification increase the frequency of dust storms, deteriorate air quality, and damage the ecological environment and agricultural production. The Xinjiang region has a relatively fragile ecological environment. Therefore, the study of the characteristics of maximum wind speed and wind direction in this region is of great significance to disaster prevention and mitigation, the management of activated dunes, and the sustainable development of the region. Based on the latest data of 71 sites in Xinjiang, this study explores the temporal evolution and spatial distribution of maximum wind speed in Xinjiang from 1993 to 2013, and highlights the distribution of annual and monthly maximum wind speed and the characteristics of wind direction in Xinjiang. Between 1993 and 2013, Ulugchat County exhibited the highest number of days with the maximum wind speed (> 17 m/s), while Wutian exhibited the lowest number. In Xinjiang, 1999 showed the highest number of maximum wind speed days (257 days), while 2013 showed the lowest number (69 days). Spring and summer wind speeds were greater than those in autumn and winter. There were obvious differences in the direction of maximum wind speed in major cities and counties of Xinjiang. East of the Tianshan Mountains, maximum wind speeds are mainly directed southeast and northeast. North and south of the Tianshan Mountains, they are mainly directed northwest and northeast, while west of the Tianshan Mountains, they are mainly directed southeast and northwest.

13 CFR 107.840 - Maximum term of Financing.

Science.gov (United States)

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maximum term of Financing. 107.840... COMPANIES Financing of Small Businesses by Licensees Structuring Licensee's Financing of An Eligible Small Business: Terms and Conditions of Financing § 107.840 Maximum term of Financing. The maximum term of any...

20 CFR 226.52 - Total annuity subject to maximum.

Science.gov (United States)

2010-04-01

... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Total annuity subject to maximum. 226.52... COMPUTING EMPLOYEE, SPOUSE, AND DIVORCED SPOUSE ANNUITIES Railroad Retirement Family Maximum § 226.52 Total annuity subject to maximum. The total annuity amount which is compared to the maximum monthly amount to...

Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

Energy Technology Data Exchange (ETDEWEB)

Bhat, J. Ishwara [Mangalore Univ., Karnataka (India); Alva, Vijaya D. P. [Shree Devi Institute of Technology, Karnataka (India)

2014-02-15

The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum.

Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

International Nuclear Information System (INIS)

Bhat, J. Ishwara; Alva, Vijaya D. P.

2014-01-01

The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum

Drought occurence

Science.gov (United States)

John W. Coulston

2007-01-01

Why Is Drought Important? Drought is an important forest disturbance that occurs regularly in the Western United States and irregularly in the Eastern United States (Dale and others 2001). Moderate drought stress tends to slow plant growth while severedrought stress can also reduce photosynthesis (Kareiva and others 1993). Drought can also interact with...

Ultraviolet light inhibition of phytochrome-induced flavonoid biosynthesis and DNA photolyase formation in mustard cotyledons (Sinapis alba L.)

International Nuclear Information System (INIS)

Buchholz, G.; Ehmann, B.; Wellmann, E.

1995-01-01

In cotyledons of etiolated mustard (Sinapis alba L.) seedlings, phytochrome-far-red-absorbing form-induced flavonoid biosynthesis was found to be inhibited by short-term ultraviolet (UV) irradiations. UV inhibition was shown for the synthesis of quercetin, anthocyanin, and also for the accumulation of the mRNA for chalcone synthase, the key enzyme of this pathway. The UV effect was more pronounced on flavonoid biosynthesis, a process that selectively occurs in the epidermal layers, than on the synthesis of mRNA for chlorophyll a/b-binding protein localized in the mesophyll tissue. These UV inhibitory effects were accompanied by cyclobutane pyrimidine dimer (CPD) formation showing a linear fluence-response relationship. CPD formation and UV inhibition of flavonoid biosynthesis was found to be partially reversible by blue/UV-A light via DNA photolyase (PRE), allowing photoreactivation of the DNA by splitting of CPDs, which are the cause of the UV effect. Like flavonoid formation PRE was also induced by the far-red-absorbing form of phytochrome and induction was inhibited by UV. A potential risk of inhibition, in response to solar UV-B irradiation, was shown for anthocyanin formation. This inhibition, however, occurred only if photoreactivation was experimentally reduced. The PRE activity present in the etiolated seedlings (further increasing about 5-fold during light acclimatization) appears to be sufficient to prevent the persistence of CPDs even under conditions of high solar irradiation

Antiangiogenic and Antitumor Effects of Src Inhibition in Ovarian Carcinoma

Science.gov (United States)

Han, Liz Y.; Landen, Charles N.; Trevino, Jose G.; Halder, Jyotsnabaran; Lin, Yvonne G.; Kamat, Aparna A.; Kim, Tae-Jin; Merritt, William M.; Coleman, Robert L.; Gershenson, David M.; Shakespeare, William C.; Wang, Yihan; Sundaramoorth, Raji; Metcalf, Chester A.; Dalgarno, David C.; Sawyer, Tomi K.; Gallick, Gary E.; Sood, Anil K.

2011-01-01

Src, a nonreceptor tyrosine kinase, is a key mediator for multiple signaling pathways that regulate critical cellular functions and is often aberrantly activated in a number of solid tumors, including ovarian carcinoma. The purpose of this study was to determine the role of activated Src inhibition on tumor growth in an orthotopic murine model of ovarian carcinoma. In vitro studies on HeyA8 and SKOV3ip1 cell lines revealed that Src inhibition by the Src-selective inhibitor, AP23846, occurred within 1 hour and responded in a dose-dependent manner. Furthermore, Src inhibition enhanced the cytotoxicity of docetaxel in both chemosensitive and chemoresistant ovarian cancer cell lines, HeyA8 and HeyA8-MDR, respectively. In vivo, Src inhibition by AP23994, an orally bioavailable analogue of AP23846, significantly decreased tumor burden in HeyA8 (P = 0.02), SKOV3ip1 (P = 0.01), as well as HeyA8-MDR (P < 0.03) relative to the untreated controls. However, the greatest effect on tumor reduction was observed in combination therapy with docetaxel (P < 0.001, P = 0.002, and P = 0.01, for the above models, respectively). Proliferating cell nuclear antigen staining showed that Src inhibition alone (P = 0.02) and in combination with docetaxel (P = 0.007) significantly reduced tumor proliferation. In addition, Src inhibition alone and in combination with docetaxel significantly down-regulated tumoral production of vascular endothelial growth factor and interleukin 8, whereas combination therapy decreased the microvessel density (P = 0.02) and significantly affected vascular permeability (P < 0.05). In summary, Src inhibition with AP23994 has potent antiangiogenic effects and significantly reduces tumor burden in preclinical ovarian cancer models. Thus, Src inhibition may be an attractive therapeutic approach for patients with ovarian carcinoma. PMID:16951177

Maximum likely scale estimation

DEFF Research Database (Denmark)

Loog, Marco; Pedersen, Kim Steenstrup; Markussen, Bo

2005-01-01

A maximum likelihood local scale estimation principle is presented. An actual implementation of the estimation principle uses second order moments of multiple measurements at a fixed location in the image. These measurements consist of Gaussian derivatives possibly taken at several scales and/or ...

The multidrug transporter ABCG2 (BCRP) is inhibited by plant-derived cannabinoids.

Science.gov (United States)

Holland, M L; Lau, D T T; Allen, J D; Arnold, J C

2007-11-01

Cannabinoids are used therapeutically for the palliation of the adverse side effects associated with cancer chemotherapy. However, cannabinoids also inhibit both the activity and expression of the multidrug transporter, P-glycoprotein in vitro. Here we address the interaction of cannabinol (CBN), cannabidiol (CBD) and delta 9-tetrahydrocannabinol (THC) with the related multidrug transporter, ABCG2. Cannabinoid inhibition of Abcg2/ABCG2 was assessed using flow cytometric analysis of substrate accumulation and ATPase activity assays. The cytotoxicity and chemosensitization by cannabinoids was determined with cell viability assays. Expression of cannabinoid and vanilloid receptors was assessed using reverse transcriptase polymerase chain reaction, and cannabinoid modulation of ABCG2 expression was examined using immunoblotting. CBN, CBD and THC increased the intracellular accumulation of the Abcg2/ABCG2 substrate, mitoxantrone, in an over-expressing cell line. The THC metabolite, (-)-11-nor-9-carboxy-delta 9-THC was much less potent. The plant cannabinoids inhibited both basal and substrate stimulated ATPase activity of human ABCG2. Cannabinoid cytotoxicity occurred in the absence of known cannabinoid cell surface receptors, and only at concentrations higher than those required for Abcg2/ABCG2 inhibition. Sub-toxic concentrations of the cannabinoids resensitized the overexpressing cell line to the cytotoxic effect of Abcg2/ABCG2 substrates, mitoxantrone and topotecan. This occurred in the absence of any effect on ABCG2 expression. Cannabinoids are novel Abcg2/ABCG2 inhibitors, reversing the Abcg2-mediated multidrug-resistant phenotype in vitro. This finding may have implications for the co-administration of cannabinoids with pharmaceuticals that are ABCG2 substrates.

Naturally Occurring Off-Switches for CRISPR-Cas9.

Science.gov (United States)

Pawluk, April; Amrani, Nadia; Zhang, Yan; Garcia, Bianca; Hidalgo-Reyes, Yurima; Lee, Jooyoung; Edraki, Alireza; Shah, Megha; Sontheimer, Erik J; Maxwell, Karen L; Davidson, Alan R

2016-12-15

CRISPR-Cas9 technology would be enhanced by the ability to inhibit Cas9 function spatially, temporally, or conditionally. Previously, we discovered small proteins encoded by bacteriophages that inhibit the CRISPR-Cas systems of their host bacteria. These "anti-CRISPRs" were specific to type I CRISPR-Cas systems that do not employ the Cas9 protein. We posited that nature would also yield Cas9 inhibitors in response to the evolutionary arms race between bacteriophages and their hosts. Here, we report the discovery of three distinct families of anti-CRISPRs that specifically inhibit the CRISPR-Cas9 system of Neisseria meningitidis. We show that these proteins bind directly to N. meningitidis Cas9 (NmeCas9) and can be used as potent inhibitors of genome editing by this system in human cells. These anti-CRISPR proteins now enable "off-switches" for CRISPR-Cas9 activity and provide a genetically encodable means to inhibit CRISPR-Cas9 genome editing in eukaryotes. VIDEO ABSTRACT. Copyright © 2016 Elsevier Inc. All rights reserved.

Productivity feedback did not terminate the Paleocene-Eocene Thermal Maximum (PETM

Directory of Open Access Journals (Sweden)

A. Torfstein

2010-04-01

Full Text Available The Paleocene-Eocene Thermal Maximum (PETM occurred approximately 55 million years ago, and is one of the most dramatic abrupt global warming events in the geological record. This warming was triggered by the sudden release of thousands of gigatons of carbon into the atmosphere and is widely perceived to be the best analogue for current anthropogenic climate change. Yet, the mechanism of recovery from this event remains controversial. A massive increase in the intensity of the marine biological pump ("productivity feedback" has been suggested to cause a drawdown of atmospheric CO₂ and subsequent carbon sequestration in the ocean. A re-evaluation of the "productivity feedback hypothesis", based on biogenic barium mass accumulation rates (Ba-MARs for a site in the Southern Ocean, finds that any increase in export production lagged the initial carbon release by at least ~70 000 years. This implies that export production did not facilitate rapid removal of excess carbon from the atmosphere. Thus, the most likely mechanism for carbon removal appears to be silicate weathering, which occurred at much slower rates than previously assumed.

Maximum gravitational redshift of white dwarfs

International Nuclear Information System (INIS)

Shapiro, S.L.; Teukolsky, S.A.

1976-01-01

The stability of uniformly rotating, cold white dwarfs is examined in the framework of the Parametrized Post-Newtonian (PPN) formalism of Will and Nordtvedt. The maximum central density and gravitational redshift of a white dwarf are determined as functions of five of the nine PPN parameters (γ, β, zeta 2 , zeta 3 , and zeta 4 ), the total angular momentum J, and the composition of the star. General relativity predicts that the maximum redshifts is 571 km s -1 for nonrotating carbon and helium dwarfs, but is lower for stars composed of heavier nuclei. Uniform rotation can increase the maximum redshift to 647 km s -1 for carbon stars (the neutronization limit) and to 893 km s -1 for helium stars (the uniform rotation limit). The redshift distribution of a larger sample of white dwarfs may help determine the composition of their cores

Nicotine inhibits collagen synthesis and alkaline phosphatase activity, but stimulates DNA synthesis in osteoblast-like cells

International Nuclear Information System (INIS)

Ramp, W.K.; Lenz, L.G.; Galvin, R.J.

1991-01-01

Use of smokeless tobacco is associated with various oral lesions including periodontal damage and alveolar bone loss. This study was performed to test the effects of nicotine on bone-forming cells at concentrations that occur in the saliva of smokeless tobacco users. Confluent cultures of osteoblast-like cells isolated from chick embryo calvariae were incubated for 2 days with nicotine added to the culture medium (25-600 micrograms/ml). Nicotine inhibited alkaline phosphatase in the cell layer and released to the medium, whereas glycolysis (as indexed by lactate production) was unaffected or slightly elevated. The effects on medium and cell layer alkaline phosphatase were concentration dependent with maximal inhibition occurring at 600 micrograms nicotine/ml. Nicotine essentially did not affect the noncollagenous protein content of the cell layer, but did inhibit collagen synthesis (hydroxylation of [ 3 H]proline and collagenase-digestible protein) at 100, 300, and 600 micrograms/ml. Release of [ 3 H]hydroxyproline to the medium was also decreased in a dose-dependent manner, as was the collagenase-digestible protein for both the medium and cell layer. In contrast, DNA synthesis (incorporation of [ 3 H]thymidine) was more than doubled by the alkaloid, whereas total DNA content was slightly inhibited at 600 micrograms/ml, suggesting stimulated cell turnover. Morphologic changes occurred in nicotine-treated cells including rounding up, detachment, and the occurrence of numerous large vacuoles. These results suggest that steps to reduce the salivary concentration of nicotine in smokeless tobacco users might diminish damaging effects of this product on alveolar bone

Inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate.

Science.gov (United States)

Damodaran, Srinivasan

2007-12-26

The inhibition of ice crystal growth in ice cream mix by gelatin hydrolysate produced by papain action was studied. The ice crystal growth was monitored by thermal cycling between -14 and -12 degrees C at a rate of one cycle per 3 min. It is shown that the hydrolysate fraction containing peptides in the molecular weight range of about 2000-5000 Da exhibited the highest inhibitory activity on ice crystal growth in ice cream mix, whereas fractions containing peptides greater than 7000 Da did not inhibit ice crystal growth. The size distribution of gelatin peptides formed in the hydrolysate was influenced by the pH of hydrolysis. The optimum hydrolysis conditions for producing peptides with maximum ice crystal growth inhibitory activity was pH 7 at 37 degrees C for 10 min at a papain to gelatin ratio of 1:100. However, this may depend on the type and source of gelatin. The possible mechanism of ice crystal growth inhibition by peptides from gelatin is discussed. Molecular modeling of model gelatin peptides revealed that they form an oxygen triad plane at the C-terminus with oxygen-oxygen distances similar to those found in ice nuclei. Binding of this oxygen triad plane to the prism face of ice nuclei via hydrogen bonding appears to be the mechanism by which gelatin hydrolysate might be inhibiting ice crystal growth in ice cream mix.

Revealing the Maximum Strength in Nanotwinned Copper

DEFF Research Database (Denmark)

Lu, L.; Chen, X.; Huang, Xiaoxu

2009-01-01

boundary–related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced...

49 CFR 195.406 - Maximum operating pressure.

Science.gov (United States)

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Maximum operating pressure. 195.406 Section 195.406 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS... HAZARDOUS LIQUIDS BY PIPELINE Operation and Maintenance § 195.406 Maximum operating pressure. (a) Except for...

Herbicide glufosinate inhibits yeast growth and extends longevity during wine fermentation.

Science.gov (United States)

Vallejo, Beatriz; Picazo, Cecilia; Orozco, Helena; Matallana, Emilia; Aranda, Agustín

2017-09-29

Glufosinate ammonium (GA) is a widely used herbicide that inhibits glutamine synthetase. This inhibition leads to internal amino acid starvation which, in turn, causes the activation of different nutrient sensing pathways. GA also inhibits the enzyme of the yeast Saccharomyces cerevisiae in such a way that, although it is not used as a fungicide, it may alter yeast performance in industrial processes like winemaking. We describe herein how GA indeed inhibits the yeast growth of a wine strain during the fermentation of grape juice. In turn, GA extends longevity in a variety of growth media. The biochemical analysis indicates that GA partially inhibits the nutrient sensing TORC1 pathway, which may explain these phenotypes. The GCN2 kinase mutant is hypersensitive to GA. Hence the control of translation and amino acid biosynthesis is required to also deal with the damaging effects of this pesticide. A global metabolomics analysis under winemaking conditions indicated that an increase in amino acid and in polyamines occurred. In conclusion, GA affects many different biochemical processes during winemaking, which provides us with some insights into both the effect of this herbicide on yeast physiology and into the relevance of the metabolic step for connecting nitrogen and carbon metabolism.

CORROSION INHIBITIVE PROPERTIES OF EXTRACT OF JATROPHA CURCAS LEAVES ON MILD STEEL IN HYDROCHLORIC ACID ENVIRONMENT

Directory of Open Access Journals (Sweden)

J. Odusote

2016-09-01

Full Text Available Jatropha curcas leaves extract was tested as a green corrosion inhibitor for mild steel in aqueous hydrochloric acid solution using gravimetric and thermometric techniques. The results reveal that the inhibition efficiency vary with concentration of the leaf extract and the time of immersion. Maximum inhibition efficiency was found to be 95.92% in 2M HCl with 0.5 g/l concentration of the extract in gravimetric method, while 87.04% was obtained in thermometric method. The inhibiting effect was attributed to the presence of alkaloids, flavonoids, saponins, tannins and phenol in the extract. The adsorption processes of the Jatropha curcas leaves extract onto the mild steel is consistent with the assumptions of Langmuir isotherm model and also found to be spontaneous. From the results, a physical adsorption mechanism is proposed for the adsorption of Jatropha curcas leaves extract onto mild steel surface.

Maximum spectral demands in the near-fault region

Science.gov (United States)

Huang, Yin-Nan; Whittaker, Andrew S.; Luco, Nicolas

2008-01-01

The Next Generation Attenuation (NGA) relationships for shallow crustal earthquakes in the western United States predict a rotated geometric mean of horizontal spectral demand, termed GMRotI50, and not maximum spectral demand. Differences between strike-normal, strike-parallel, geometric-mean, and maximum spectral demands in the near-fault region are investigated using 147 pairs of records selected from the NGA strong motion database. The selected records are for earthquakes with moment magnitude greater than 6.5 and for closest site-to-fault distance less than 15 km. Ratios of maximum spectral demand to NGA-predicted GMRotI50 for each pair of ground motions are presented. The ratio shows a clear dependence on period and the Somerville directivity parameters. Maximum demands can substantially exceed NGA-predicted GMRotI50 demands in the near-fault region, which has significant implications for seismic design, seismic performance assessment, and the next-generation seismic design maps. Strike-normal spectral demands are a significantly unconservative surrogate for maximum spectral demands for closest distance greater than 3 to 5 km. Scale factors that transform NGA-predicted GMRotI50 to a maximum spectral demand in the near-fault region are proposed.

Removal of oxytetracycline (OTC) in a synthetic pharmaceutical wastewater by a sequential anaerobic multichamber bed reactor (AMCBR)/completely stirred tank reactor (CSTR) system: biodegradation and inhibition kinetics.

Science.gov (United States)

Sponza, Delia Teresa; Çelebi, Hakan

2012-01-01

An anaerobic multichamber bed reactor (AMCBR) was effective in removing both molasses-chemical oxygen demand (COD), and the antibiotic oxytetracycline (OTC). The maximum COD and OTC removals were 99% in sequential AMCBR/completely stirred tank reactor (CSTR) at an OTC concentration of 300 mg L(-1). 51%, 29% and 9% of the total volatile fatty acid (TVFA) was composed of acetic, propionic acid and butyric acids, respectively. The OTC loading rates at between 22.22 and 133.33 g OTC m(-3) d(-1) improved the hydrolysis of molasses-COD (k), the maximum specific utilization of molasses-COD (k(mh)) and the maximum specific utilization rate of TVFA (k(TVFA)). The direct effect of high OTC loadings (155.56 and -177.78 g OTC m(-3) d(-1)) on acidogens and methanogens were evaluated with Haldane inhibition kinetic. A significant decrease of the Haldane inhibition constant was indicative of increases in toxicity at increasing loading rates. Copyright © 2011 Elsevier Ltd. All rights reserved.

Maximum allowable load on wheeled mobile manipulators

International Nuclear Information System (INIS)

Habibnejad Korayem, M.; Ghariblu, H.

2003-01-01

This paper develops a computational technique for finding the maximum allowable load of mobile manipulator during a given trajectory. The maximum allowable loads which can be achieved by a mobile manipulator during a given trajectory are limited by the number of factors; probably the dynamic properties of mobile base and mounted manipulator, their actuator limitations and additional constraints applied to resolving the redundancy are the most important factors. To resolve extra D.O.F introduced by the base mobility, additional constraint functions are proposed directly in the task space of mobile manipulator. Finally, in two numerical examples involving a two-link planar manipulator mounted on a differentially driven mobile base, application of the method to determining maximum allowable load is verified. The simulation results demonstrates the maximum allowable load on a desired trajectory has not a unique value and directly depends on the additional constraint functions which applies to resolve the motion redundancy

Robust Maximum Association Estimators

NARCIS (Netherlands)

A. Alfons (Andreas); C. Croux (Christophe); P. Filzmoser (Peter)

2017-01-01

textabstractThe maximum association between two multivariate variables X and Y is defined as the maximal value that a bivariate association measure between one-dimensional projections αX and αY can attain. Taking the Pearson correlation as projection index results in the first canonical correlation

Public Health Goal for Naturally Occurring Radionuclides in Groundwater

International Nuclear Information System (INIS)

Kamel, N.H.M.; Omar, H.A.; El-Baset, L.A.

2008-01-01

Naturally occurring and man-made radionuclide in groundwater may have a health hazardous to some residents. The objective of this work is to provide criteria for safety of drinking-water with respect to the chemical parameters and the radionuclide content. The annual effective dose for the consumption of drinking water was considered. Ground water samples were selected from different sites in Egypt, that have the most population, it were taken from aquifer regions along Giza sites in Egypt. Chemical analyses for the major anions, cations, and the radiological analyses were tested . Activity concentrations (Bq/l) of the gross alpha and the gross beta activities of our investigated samples were compared with the maximum contaminant level (MCL) of the world health organization (WHO). Some of the water samples were found to have a higher of gross beta and alpha particles than the MCL. Alpha activity were found depending on to the total dissolved solids (TDS) content of the water samples. Gamma activity concentrations were analyzed using low background germanium detector, the higher of activity values was found in some investigated samples is due to increasing of 226 Ra and 228 Ra activities. Tritium activity concentrations also were measured using soft beta liquid scintillation counter, it was found lower than the MCL. Our investigated samples were found to have a higher concentrations of the phosphate, nitrites, iron, and manganese contents than the maximum permissible limit, all the ground water samples were found to have a higher of silica and alumina content. Commercial carbon powder and natural clay materials were tested as ion exchangers for the removal of inorganic contaminants in the ground water samples. Clay materials was found to have a higher selectivity than activated carbon for the removal of radionuclides, phosphates, nitrites, and manganese content at the ground water samples

Selection of the Maximum Spatial Cluster Size of the Spatial Scan Statistic by Using the Maximum Clustering Set-Proportion Statistic.

Science.gov (United States)

Ma, Yue; Yin, Fei; Zhang, Tao; Zhou, Xiaohua Andrew; Li, Xiaosong

2016-01-01

Spatial scan statistics are widely used in various fields. The performance of these statistics is influenced by parameters, such as maximum spatial cluster size, and can be improved by parameter selection using performance measures. Current performance measures are based on the presence of clusters and are thus inapplicable to data sets without known clusters. In this work, we propose a novel overall performance measure called maximum clustering set-proportion (MCS-P), which is based on the likelihood of the union of detected clusters and the applied dataset. MCS-P was compared with existing performance measures in a simulation study to select the maximum spatial cluster size. Results of other performance measures, such as sensitivity and misclassification, suggest that the spatial scan statistic achieves accurate results in most scenarios with the maximum spatial cluster sizes selected using MCS-P. Given that previously known clusters are not required in the proposed strategy, selection of the optimal maximum cluster size with MCS-P can improve the performance of the scan statistic in applications without identified clusters.

Influence of Thread Root Radius on Maximum Local Stresses at Large Diameter Bolts under Axial Loading

Directory of Open Access Journals (Sweden)

Cojocaru Vasile

2014-06-01

Full Text Available In the thread root area of the threaded bolts submitted to axial loading occur local stresses, higher that nominal stresses calculated for the bolts. These local stresses can generate failure and can reduce the fatigue life of the parts. The paper is focused on the study of the influence of the thread root radius on the maximum local stresses. A large diameter trapezoidal bolt was subjected to a static analysis (axial loading using finite element simulation.

Correlation between the Inhibition of Positronium Formation by Scavenger Molecules, and Chemical Reaction Rate of Electrons with these Molecules in Nonpolar Liquids

DEFF Research Database (Denmark)

Levay, B.; Mogensen, O. E.

1977-01-01

a correlation between the inhibition coefficient and the chemical rate constant of electrons with scavenger molecules. We found that the dependence of the inhibition coefficient on the work function (VOo)f electrons in different liquids shows a very unusual behavior, similar to that recently found...... for the chemical rate constants of quasifree electrons with the same scavenger molecules. The inhibition coefficient as a function of Vo had a maximum for C2HsBr, while it increased monotonously with decreasing V, for CC14. The inhibition coefficient for C2H5Br in a 1:l molar tetramethylsilane......-n-tetradecane mixture was found to be greater than in both of the pure components. The clear correlation found between electron scavenging rate constants and positronium inhibition constitutes the severest test to date of the spur reaction model of positronium formation. The importance of the positron annihilation...

Maximum-Likelihood Detection Of Noncoherent CPM

Science.gov (United States)

Divsalar, Dariush; Simon, Marvin K.

1993-01-01

Simplified detectors proposed for use in maximum-likelihood-sequence detection of symbols in alphabet of size M transmitted by uncoded, full-response continuous phase modulation over radio channel with additive white Gaussian noise. Structures of receivers derived from particular interpretation of maximum-likelihood metrics. Receivers include front ends, structures of which depends only on M, analogous to those in receivers of coherent CPM. Parts of receivers following front ends have structures, complexity of which would depend on N.

Light-stimulated cell expansion in bean (Phaseolus vulgaris L.) leaves. I. Growth can occur without photosynthesis

Science.gov (United States)

Van Volkenburgh, E.; Cleland, R. E.

1990-01-01

Cell expansion in dicotyledonous leaves is strongly stimulated by bright white light (WL), at least in part as a result of light-induced acidification of the cell walls. It has been proposed that photosynthetic reactions are required for light-stimulated transport processes across plasma membranes of leaf cells, including proton excretion. The involvement of photosynthesis in growth and wall acidification of primary leaves of bean has been tested by inhibiting photosynthesis in two ways: by reducing chlorophyll content of intact plants with tentoxin (TX) and by treating leaf discs with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU). Exposure to bright WL stimulated growth of intact leaves of TX-treated plants. Discs excised from green as well as from TX-or DCMU-treated leaves also responded by growing faster in WL, as long as exogenous sucrose was supplied to the photosynthetically inhibited tissues. The WL caused acidification of the epidermal surface of intact TX-leaves, but acidification of the incubation medium by mesophyll cells only occurred when photosynthesis was not inhibited. It is concluded that light-stimulated cell enlargement of bean leaves, and the necessary acidification of epidermal cell walls, are mediated by a pigment other than chlorophyll. Light-induced proton excretion by mesophyll cells, on the other hand, may require both a photosynthetic product (or exogenous sugars) and a non-photosynthetic light effect.

Maximum Entropy Fundamentals

Directory of Open Access Journals (Sweden)

F. Topsøe

2001-09-01

Full Text Available Abstract: In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over

A broad range quorum sensing inhibitor working through sRNA inhibition

DEFF Research Database (Denmark)

Jakobsen, Tim H.; Warming, Anders N.; Vejborg, Rebecca M.

2017-01-01

that the repressing effect of ajoene on quorum sensing occurs by inhibition of small regulatory RNAs (sRNA) in P. aeruginosa as well as in Staphylococcus aureus, another important human pathogen that employs quorum sensing to control virulence gene expression. Using various reporter constructs, we found that ajoene......-spectrum compounds transcending the Gram negative-positive borderline....

Maximum Credible Incidents

CERN Document Server

Strait, J

2009-01-01

Following the incident in sector 34, considerable effort has been made to improve the systems for detecting similar faults and to improve the safety systems to limit the damage if a similar incident should occur. Nevertheless, even after the consolidation and repairs are completed, other faults may still occur in the superconducting magnet systems, which could result in damage to the LHC. Such faults include both direct failures of a particular component or system, or an incorrect response to a “normal” upset condition, for example a quench. I will review a range of faults which could be reasonably expected to occur in the superconducting magnet systems, and which could result in substantial damage and down-time to the LHC. I will evaluate the probability and the consequences of such faults, and suggest what mitigations, if any, are possible to protect against each.

22 CFR 201.67 - Maximum freight charges.

Science.gov (United States)

2010-04-01

..., commodity rate classification, quantity, vessel flag category (U.S.-or foreign-flag), choice of ports, and... the United States. (2) Maximum charter rates. (i) USAID will not finance ocean freight under any... owner(s). (4) Maximum liner rates. USAID will not finance ocean freight for a cargo liner shipment at a...

Bacterial inhibiting surfaces caused by the effects of silver release and/or electrical field

DEFF Research Database (Denmark)

Chiang, Wen-Chi; Hilbert, Lisbeth Rischel; Schroll, Casper

2008-01-01

In this study, silver-palladium surfaces and silver-bearing stainless steels were designed and investigated focusing on electrochemical principles to form inhibiting effects on planktonic and/or biofilm bacteria in water systems. Silver-resistant Escherichia coli and silver-sensitive E. coli were...... silver ions release can occur from their Surfaces. For silver-bearing stainless steels, the inhibiting effect can only be explained by high local silver ions release. and can be limited or deactivated dependent on the specific environment. (c) 2008 Elsevier Ltd. All rights reserved....

Study on Corrosion Inhibition Efficiency of Stem Alkaloid Extract of Different Varieties of Holy Basil on Aluminium in HCl Solution

Energy Technology Data Exchange (ETDEWEB)

Kumpawat, Nutan; Chaturvedi, Alok; Upadhyay, R. K. [Synthetic and Surface Science Laboratory, Ajmer (India)

2012-08-15

Corrosion inhibition efficiencies of holy basil on Al in HCl solution were studied by weight loss and thermometric methods in presence and in absence of stem extract of three different varieties of holy basil viz. ocimum basilicum (E{sub B}), ocimum canum (E{sub C}) and ocimum sanctum (E{sub S}). Inhibition efficiency increases with the increasing concentration of stem extract and decreases with increases in acid strength. Results show that all varieties under study are good corrosion inhibitors, among which, E{sub B} is most effective. Maximum inhibition efficiency was found 97.09% in 0.5N HCl solution with 0.6% stem extract. The Langmuir adsorption isotherm indicates that surface coverage also increases with increasing in the concentration of extract of stem in HCl solution.

Study on Corrosion Inhibition Efficiency of Stem Alkaloid Extract of Different Varieties of Holy Basil on Aluminium in HCl Solution

International Nuclear Information System (INIS)

Kumpawat, Nutan; Chaturvedi, Alok; Upadhyay, R. K.

2012-01-01

Corrosion inhibition efficiencies of holy basil on Al in HCl solution were studied by weight loss and thermometric methods in presence and in absence of stem extract of three different varieties of holy basil viz. ocimum basilicum (E B ), ocimum canum (E C ) and ocimum sanctum (E S ). Inhibition efficiency increases with the increasing concentration of stem extract and decreases with increases in acid strength. Results show that all varieties under study are good corrosion inhibitors, among which, E B is most effective. Maximum inhibition efficiency was found 97.09% in 0.5N HCl solution with 0.6% stem extract. The Langmuir adsorption isotherm indicates that surface coverage also increases with increasing in the concentration of extract of stem in HCl solution

Determination of the maximum-depth to potential field sources by a maximum structural index method

Science.gov (United States)

Fedi, M.; Florio, G.

2013-01-01

A simple and fast determination of the limiting depth to the sources may represent a significant help to the data interpretation. To this end we explore the possibility of determining those source parameters shared by all the classes of models fitting the data. One approach is to determine the maximum depth-to-source compatible with the measured data, by using for example the well-known Bott-Smith rules. These rules involve only the knowledge of the field and its horizontal gradient maxima, and are independent from the density contrast. Thanks to the direct relationship between structural index and depth to sources we work out a simple and fast strategy to obtain the maximum depth by using the semi-automated methods, such as Euler deconvolution or depth-from-extreme-points method (DEXP). The proposed method consists in estimating the maximum depth as the one obtained for the highest allowable value of the structural index (Nmax). Nmax may be easily determined, since it depends only on the dimensionality of the problem (2D/3D) and on the nature of the analyzed field (e.g., gravity field or magnetic field). We tested our approach on synthetic models against the results obtained by the classical Bott-Smith formulas and the results are in fact very similar, confirming the validity of this method. However, while Bott-Smith formulas are restricted to the gravity field only, our method is applicable also to the magnetic field and to any derivative of the gravity and magnetic field. Our method yields a useful criterion to assess the source model based on the (∂f/∂x)max/fmax ratio. The usefulness of the method in real cases is demonstrated for a salt wall in the Mississippi basin, where the estimation of the maximum depth agrees with the seismic information.

Adsorption and corrosion inhibiting effect of riboflavin on Q235 mild steel corrosion in acidic environments

Energy Technology Data Exchange (ETDEWEB)

Chidiebere, Maduabuchi A. [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Electrochemistry and Materials Science Research Laboratory, Department of Chemistry, Federal University of Technology Owerri, PMB 1526 Owerri (Nigeria); Oguzie, Emeka E. [Electrochemistry and Materials Science Research Laboratory, Department of Chemistry, Federal University of Technology Owerri, PMB 1526 Owerri (Nigeria); Liu, Li [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Li, Ying, E-mail: liying@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Wang, Fuhui [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China)

2015-04-15

The inhibiting effect of Riboflavin (RF) on Q235 mild steel corrosion in 1 M HCl and 0.5 M H{sub 2}SO{sub 4} at 30 °C temperature was investigated using electrochemical techniques (electrochemical impedance spectroscopy and potentiodynamic polarization). The obtained results revealed that RF inhibited the corrosion reaction in both acidic solutions. Maximum inhibition efficiency values in 1 M HCl and 0.5 M H{sub 2}SO{sub 4} were 83.9% and 71.4%, respectively, obtained for 0.0012 M RF. Polarization data showed RF to be a mixed-type inhibitor, while EIS results revealed that the RF species adsorbed on the metal surface. The adsorption of RF followed Langmuir adsorption isotherm. Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) studies confirmed the formation of a protective layer adsorbed on the steel surface. Quantum chemical calculations were used to correlate the inhibition ability of RF with its electronic structural parameters. - Highlights: • The inhibitory mechanism was influenced by the nature of acid anions. • RF has reasonable inhibition effect especially in 1 M HCl solution. • Polarization studies showed that RF functioned as a mixed type inhibitor. • Improved surface morphology was observed in the presence of RF.

40 CFR 141.13 - Maximum contaminant levels for turbidity.

Science.gov (United States)

2010-07-01

... turbidity. 141.13 Section 141.13 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Maximum contaminant levels for turbidity. The maximum contaminant levels for turbidity are applicable to... part. The maximum contaminant levels for turbidity in drinking water, measured at a representative...

Modelling maximum canopy conductance and transpiration in ...

African Journals Online (AJOL)

There is much current interest in predicting the maximum amount of water that can be transpired by Eucalyptus trees. It is possible that industrial waste water may be applied as irrigation water to eucalypts and it is important to predict the maximum transpiration rates of these plantations in an attempt to dispose of this ...

40 CFR 141.62 - Maximum contaminant levels for inorganic contaminants.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for inorganic contaminants. 141.62 Section 141.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.62 Maximum...

Stimulus-category competition, inhibition, and affective devaluation: a novel account of the uncanny valley.

Science.gov (United States)

Ferrey, Anne E; Burleigh, Tyler J; Fenske, Mark J

2015-01-01

Stimuli that resemble humans, but are not perfectly human-like, are disliked compared to distinctly human and non-human stimuli. Accounts of this "Uncanny Valley" effect often focus on how changes in human resemblance can evoke different emotional responses. We present an alternate account based on the novel hypothesis that the Uncanny Valley is not directly related to 'human-likeness' per se, but instead reflects a more general form of stimulus devaluation that occurs when inhibition is triggered to resolve conflict between competing stimulus-related representations. We consider existing support for this inhibitory-devaluation hypothesis and further assess its feasibility through tests of two corresponding predictions that arise from the link between conflict-resolving inhibition and aversive response: (1) that the pronounced disliking of Uncanny-type stimuli will occur for any image that strongly activates multiple competing stimulus representations, even in the absence of any human-likeness, and (2) that the negative peak of an 'Uncanny Valley' should occur at the point of greatest stimulus-related conflict and not (in the presence of human-likeness) always closer to the 'human' end of a perceptual continuum. We measured affective responses to a set of line drawings representing non-human animal-animal morphs, in which each continuum midpoint was a bistable image (Experiment 1), as well as to sets of human-robot and human-animal computer-generated morphs (Experiment 2). Affective trends depicting classic Uncanny Valley functions occurred for all continua, including the non-human stimuli. Images at continua midpoints elicited significantly more negative affect than images at endpoints, even when the continua included a human endpoint. This illustrates the feasibility of the inhibitory-devaluation hypothesis and the need for further research into the possibility that the strong dislike of Uncanny-type stimuli reflects the negative affective consequences of

Stimulus-category competition, inhibition and affective devaluation: A novel account of the Uncanny Valley

Directory of Open Access Journals (Sweden)

Anne E. Ferrey

2015-03-01

Full Text Available Stimuli that resemble humans, but are not perfectly human-like, are disliked compared to distinctly human and nonhuman stimuli. Accounts of this Uncanny Valley effect often focus on how changes in human resemblance can evoke different emotional responses. We present an alternate account based on the novel hypothesis that the Uncanny Valley is not directly related to ‘human-likeness’ per se, but instead reflects a more general form of stimulus devaluation that occurs when inhibition is triggered to resolve conflict between competing stimulus-related representations. We consider existing support for this inhibitory-devaluation hypothesis and further assess its feasibility through tests of two corresponding predictions that arise from the link between conflict-resolving inhibition and aversive response: 1 that the pronounced disliking of Uncanny-type stimuli will occur for any image that strongly activates multiple competing stimulus representations, even in the absence of any human-likeness, and 2 that the negative peak of an ‘Uncanny Valley’ should occur at the point of greatest stimulus-related conflict and not (in the presence of human-likeness always closer to the ‘human’ end of a perceptual continuum. We measured affective responses to a set of line drawings representing nonhuman animal-animal morphs, in which each continuum midpoint was a bistable image (Exp. 1, as well as to sets of human-robot and human-animal computer-generated morphs (Exp. 2. Affective trends depicting classic Uncanny Valley functions occurred for all continua, including the nonhuman stimuli. Images at continua midpoints elicited significantly more negative affect than images at endpoints, even when the continua included a human endpoint. This illustrates the feasibility of the inhibitory-devaluation hypothesis and the need for further research into the possibility that the strong dislike of Uncanny-type stimuli reflects the negative affective consequences of

Weak scale from the maximum entropy principle

Science.gov (United States)

Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu

2015-03-01

The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.

Proteasome Inhibition Suppresses Dengue Virus Egress in Antibody Dependent Infection.

Directory of Open Access Journals (Sweden)

Milly M Choy

2015-11-01

Full Text Available The mosquito-borne dengue virus (DENV is a cause of significant global health burden, with an estimated 390 million infections occurring annually. However, no licensed vaccine or specific antiviral treatment for dengue is available. DENV interacts with host cell factors to complete its life cycle although this virus-host interplay remains to be fully elucidated. Many studies have identified the ubiquitin proteasome pathway (UPP to be important for successful DENV production, but how the UPP contributes to DENV life cycle as host factors remains ill defined. We show here that proteasome inhibition decouples infectious virus production from viral RNA replication in antibody-dependent infection of THP-1 cells. Molecular and imaging analyses in β-lactone treated THP-1 cells suggest that proteasome function does not prevent virus assembly but rather DENV egress. Intriguingly, the licensed proteasome inhibitor, bortezomib, is able to inhibit DENV titers at low nanomolar drug concentrations for different strains of all four serotypes of DENV in primary monocytes. Furthermore, bortezomib treatment of DENV-infected mice inhibited the spread of DENV in the spleen as well as the overall pathological changes. Our findings suggest that preventing DENV egress through proteasome inhibition could be a suitable therapeutic strategy against dengue.

Accurate modeling and maximum power point detection of ...

African Journals Online (AJOL)

Accurate modeling and maximum power point detection of photovoltaic ... Determination of MPP enables the PV system to deliver maximum available power. ..... adaptive artificial neural network: Proposition for a new sizing procedure.

40 CFR 141.61 - Maximum contaminant levels for organic contaminants.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for organic contaminants. 141.61 Section 141.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER... Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.61 Maximum contaminant...

The power and robustness of maximum LOD score statistics.

Science.gov (United States)

Yoo, Y J; Mendell, N R

2008-07-01

The maximum LOD score statistic is extremely powerful for gene mapping when calculated using the correct genetic parameter value. When the mode of genetic transmission is unknown, the maximum of the LOD scores obtained using several genetic parameter values is reported. This latter statistic requires higher critical value than the maximum LOD score statistic calculated from a single genetic parameter value. In this paper, we compare the power of maximum LOD scores based on three fixed sets of genetic parameter values with the power of the LOD score obtained after maximizing over the entire range of genetic parameter values. We simulate family data under nine generating models. For generating models with non-zero phenocopy rates, LOD scores maximized over the entire range of genetic parameters yielded greater power than maximum LOD scores for fixed sets of parameter values with zero phenocopy rates. No maximum LOD score was consistently more powerful than the others for generating models with a zero phenocopy rate. The power loss of the LOD score maximized over the entire range of genetic parameters, relative to the maximum LOD score calculated using the correct genetic parameter value, appeared to be robust to the generating models.

Maximum Power Training and Plyometrics for Cross-Country Running.

Science.gov (United States)

Ebben, William P.

2001-01-01

Provides a rationale for maximum power training and plyometrics as conditioning strategies for cross-country runners, examining: an evaluation of training methods (strength training and maximum power training and plyometrics); biomechanic and velocity specificity (role in preventing injury); and practical application of maximum power training and…

A rapid method for measuring maximum density temperatures in water and aqueous solutions for the study of quantum zero point energy effects in these liquids

International Nuclear Information System (INIS)

Deeney, F A; O'Leary, J P

2008-01-01

The connection between quantum zero point fluctuations and a density maximum in water and in liquid He 4 has recently been established. Here we present a description of a simple and rapid method of determining the temperatures at which maximum densities in water and aqueous solutions occur. The technique is such as to allow experiments to be carried out in one session of an undergraduate laboratory thereby introducing students to the concept of quantum zero point energy

Hepatitis B Virus Core Protein Dephosphorylation Occurs during Pregenomic RNA Encapsidation.

Science.gov (United States)

Zhao, Qiong; Hu, Zhanying; Cheng, Junjun; Wu, Shuo; Luo, Yue; Chang, Jinhong; Hu, Jianming; Guo, Ju-Tao

2018-07-01

Hepatitis B virus (HBV) core protein consists of an N-terminal assembly domain and a C-terminal domain (CTD) with seven conserved serines or threonines that are dynamically phosphorylated/dephosphorylated during the viral replication cycle. Sulfamoylbenzamide derivatives are small molecular core protein allosteric modulators (CpAMs) that bind to the heteroaryldihydropyrimidine (HAP) pocket between the core protein dimer-dimer interfaces. CpAM binding alters the kinetics and pathway of capsid assembly and can result in the formation of morphologically "normal" capsids devoid of viral pregenomic RNA (pgRNA) and DNA polymerase. In order to investigate the mechanism underlying CpAM inhibition of pgRNA encapsidation, we developed an immunoblotting assay that can resolve core protein based on its phosphorylation status and demonstrated, for the first time, that core protein is hyperphosphorylated in free dimers and empty capsids from both mock-treated and CpAM-treated cells but is hypophosphorylated in pgRNA- and DNA-containing nucleocapsids. Interestingly, inhibition of pgRNA encapsidation by a heat shock protein 90 (HSP90) inhibitor prevented core protein dephosphorylation. Moreover, core proteins with point mutations at the wall of the HAP pocket, V124A and V124W, assembled empty capsids and nucleocapsids with altered phosphorylation status. The results thus suggest that core protein dephosphorylation occurs in the assembly of pgRNA and that interference with the interaction between core protein subunits at dimer-dimer interfaces during nucleocapsid assembly alters not only capsid structure, but also core protein dephosphorylation. Hence, inhibition of pgRNA encapsidation by CpAMs might be due to disruption of core protein dephosphorylation during nucleocapsid assembly. IMPORTANCE Dynamic phosphorylation of HBV core protein regulates multiple steps of viral replication. However, the regulatory function was mainly investigated by phosphomimetic mutagenesis, which

Inhibition of fouling by animal growth - a study using wood constituents

International Nuclear Information System (INIS)

Shukla, S.K.

1983-01-01

Inhibitory effects of constituents from Dalbergia retusa, Tectona grandis and Lophira procera heartwoods on fouling were studied in field and laboratory tests and compared with a copper paint. Lophira extract impaired fouling by barnacles and tubeworms, R-4 methoxydalbergione, obtusaquinone and lapachol didn't. Lapachol proved to be more effective than R-4 methoxydalbergione and obtusaquinone against Balanus improvisus in LD 50 -tests. Maximum inhibition of 45 Ca and 14 C uptake in the shell of Balanus improvisus was caused by lapachol. The same trend was observed in studies on alkaline phosphatase of mantel. (orig.) [de

Maximum physical capacity testing in cancer patients undergoing chemotherapy

DEFF Research Database (Denmark)

Knutsen, L.; Quist, M; Midtgaard, J

2006-01-01

BACKGROUND: Over the past few years there has been a growing interest in the field of physical exercise in rehabilitation of cancer patients, leading to requirements for objective maximum physical capacity measurement (maximum oxygen uptake (VO(2max)) and one-repetition maximum (1RM)) to determin...... early in the treatment process. However, the patients were self-referred and thus highly motivated and as such are not necessarily representative of the whole population of cancer patients treated with chemotherapy....... in performing maximum physical capacity tests as these motivated them through self-perceived competitiveness and set a standard that served to encourage peak performance. CONCLUSION: The positive attitudes in this sample towards maximum physical capacity open the possibility of introducing physical testing...

Antimutagenic activity of some naturally occurring compounds towards cigarette-smoke condensate and benzo(a)pyrene in the Salmonella/microsome assay

Energy Technology Data Exchange (ETDEWEB)

Terwel, L.; van der Hoeven, J.C.

1985-10-01

Several compounds, occurring in food, were tested for antimutagenic activity towards cigarette-smoke condensate (CSC) and benzo(a)pyrene (BaP). Antimutagenicity was determined in the Salmonella/microsome test, with tester strain TA98, in the presence of rat-liver homogenate. Dose-response curves did show reduction of CSC- and BaP-induced mutagenicity by ellagic acid, riboflavin and chlorophyllin. Chlorophyll a and chlorophyll b, although less distinct, also inhibited CSC- and BaP-induced mutagenicity. Ascorbic acid, beta-carotene, tocopherol acetate, chlorogenic acid and butyl hydroxyanisole did not have any influence on the mutagenicity of CSC and BaP. The similarity in results for cigarette-smoke condensate and for BaP indicates that a general mechanism may be involved in the inhibition of CSC- and BaP-induced mutagenicity.

MAXIMUM PRINCIPLE FOR SUBSONIC FLOW WITH VARIABLE ENTROPY

Directory of Open Access Journals (Sweden)

B. Sizykh Grigory

2017-01-01

Full Text Available Maximum principle for subsonic flow is fair for stationary irrotational subsonic gas flows. According to this prin- ciple, if the value of the velocity is not constant everywhere, then its maximum is achieved on the boundary and only on the boundary of the considered domain. This property is used when designing form of an aircraft with a maximum critical val- ue of the Mach number: it is believed that if the local Mach number is less than unit in the incoming flow and on the body surface, then the Mach number is less then unit in all points of flow. The known proof of maximum principle for subsonic flow is based on the assumption that in the whole considered area of the flow the pressure is a function of density. For the ideal and perfect gas (the role of diffusion is negligible, and the Mendeleev-Clapeyron law is fulfilled, the pressure is a function of density if entropy is constant in the entire considered area of the flow. Shows an example of a stationary sub- sonic irrotational flow, in which the entropy has different values on different stream lines, and the pressure is not a function of density. The application of the maximum principle for subsonic flow with respect to such a flow would be unreasonable. This example shows the relevance of the question about the place of the points of maximum value of the velocity, if the entropy is not a constant. To clarify the regularities of the location of these points, was performed the analysis of the com- plete Euler equations (without any simplifying assumptions in 3-D case. The new proof of the maximum principle for sub- sonic flow was proposed. This proof does not rely on the assumption that the pressure is a function of density. Thus, it is shown that the maximum principle for subsonic flow is true for stationary subsonic irrotational flows of ideal perfect gas with variable entropy.

Maximum power point tracker based on fuzzy logic

International Nuclear Information System (INIS)

Daoud, A.; Midoun, A.

2006-01-01

The solar energy is used as power source in photovoltaic power systems and the need for an intelligent power management system is important to obtain the maximum power from the limited solar panels. With the changing of the sun illumination due to variation of angle of incidence of sun radiation and of the temperature of the panels, Maximum Power Point Tracker (MPPT) enables optimization of solar power generation. The MPPT is a sub-system designed to extract the maximum power from a power source. In the case of solar panels power source. the maximum power point varies as a result of changes in its electrical characteristics which in turn are functions of radiation dose, temperature, ageing and other effects. The MPPT maximum the power output from panels for a given set of conditions by detecting the best working point of the power characteristic and then controls the current through the panels or the voltage across them. Many MPPT methods have been reported in literature. These techniques of MPPT can be classified into three main categories that include: lookup table methods, hill climbing methods and computational methods. The techniques vary according to the degree of sophistication, processing time and memory requirements. The perturbation and observation algorithm (hill climbing technique) is commonly used due to its ease of implementation, and relative tracking efficiency. However, it has been shown that when the insolation changes rapidly, the perturbation and observation method is slow to track the maximum power point. In recent years, the fuzzy controllers are used for maximum power point tracking. This method only requires the linguistic control rules for maximum power point, the mathematical model is not required and therefore the implementation of this control method is easy to real control system. In this paper, we we present a simple robust MPPT using fuzzy set theory where the hardware consists of the microchip's microcontroller unit control card and

Actinonin, a naturally occurring antibacterial agent, is a potent deformylase inhibitor.

Science.gov (United States)

Chen, D Z; Patel, D V; Hackbarth, C J; Wang, W; Dreyer, G; Young, D C; Margolis, P S; Wu, C; Ni, Z J; Trias, J; White, R J; Yuan, Z

2000-02-15

Peptide deformylase (PDF) is essential in prokaryotes and absent in mammalian cells, thus making it an attractive target for the discovery of novel antibiotics. We have identified actinonin, a naturally occurring antibacterial agent, as a potent PDF inhibitor. The dissociation constant for this compound was 0.3 x 10(-)(9) M against Ni-PDF from Escherichia coli; the PDF from Staphylococcus aureus gave a similar value. Microbiological evaluation revealed that actinonin is a bacteriostatic agent with activity against Gram-positive and fastidious Gram-negative microorganisms. The PDF gene, def, was placed under control of P(BAD) in E. coli tolC, permitting regulation of PDF expression levels in the cell by varying the external arabinose concentration. The susceptibility of this strain to actinonin increases with decreased levels of PDF expression, indicating that actinonin inhibits bacterial growth by targeting this enzyme. Actinonin provides an excellent starting point from which to derive a more potent PDF inhibitor that has a broader spectrum of antibacterial activity.

Inhibition of the mitotic exit network in response to damaged telomeres.

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Mauricio Valerio-Santiago

Full Text Available When chromosomal DNA is damaged, progression through the cell cycle is halted to provide the cells with time to repair the genetic material before it is distributed between the mother and daughter cells. In Saccharomyces cerevisiae, this cell cycle arrest occurs at the G2/M transition. However, it is also necessary to restrain exit from mitosis by maintaining Bfa1-Bub2, the inhibitor of the Mitotic Exit Network (MEN, in an active state. While the role of Bfa1 and Bub2 in the inhibition of mitotic exit when the spindle is not properly aligned and the spindle position checkpoint is activated has been extensively studied, the mechanism by which these proteins prevent MEN function after DNA damage is still unclear. Here, we propose that the inhibition of the MEN is specifically required when telomeres are damaged but it is not necessary to face all types of chromosomal DNA damage, which is in agreement with previous data in mammals suggesting the existence of a putative telomere-specific DNA damage response that inhibits mitotic exit. Furthermore, we demonstrate that the mechanism of MEN inhibition when telomeres are damaged relies on the Rad53-dependent inhibition of Bfa1 phosphorylation by the Polo-like kinase Cdc5, establishing a new key role of this kinase in regulating cell cycle progression.

Maximum entropy methods

International Nuclear Information System (INIS)

Ponman, T.J.

1984-01-01

For some years now two different expressions have been in use for maximum entropy image restoration and there has been some controversy over which one is appropriate for a given problem. Here two further entropies are presented and it is argued that there is no single correct algorithm. The properties of the four different methods are compared using simple 1D simulations with a view to showing how they can be used together to gain as much information as possible about the original object. (orig.)

Algal growth inhibition test in filled, closed bottles for volatile and sorptive materials

DEFF Research Database (Denmark)

Mayer, Philipp; Nyholm, Niels; Verbruggen, Eric M. J.

2000-01-01

Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well as to the......Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well......, and the resulting dissolved CO2 concentration supported maximum algal growth rates without pH drift for algal densities up to 4 mg dry weight/L. Two-day toxicity tests with kerosene were performed with this new test design and compared with an open bottle test and with a closed bottle test with headspace. Exposure...... concentrations of the volatile fraction of kerosene decreased by 99% in the open test, by 77% in the closed flask test with headspace, and by 16% in the filled closed bottle test. Algal growth inhibition was observed at much lower additions of kerosene in the new test design because of the improved maintenance...

Cyclooxgenase-2 inhibiting perfluoropoly (ethylene glycol ether theranostic nanoemulsions-in vitro study.

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Sravan Kumar Patel

Full Text Available Cylcooxgenase-2 (COX-2 expressing macrophages, constituting a major portion of tumor mass, are involved in several pro-tumorigenic mechanisms. In addition, macrophages are actively recruited by the tumor and represent a viable target for anticancer therapy. COX-2 specific inhibitor, celecoxib, apart from its anticancer properties was shown to switch macrophage phenotype from tumor promoting to tumor suppressing. Celecoxib has low aqueous solubility, which may limit its tumor inhibiting effect. As opposed to oral administration, we propose that maximum anticancer effect may be achieved by nanoemulsion mediated intravenous delivery. Here we report multifunctional celecoxib nanoemulsions that can be imaged by both near-infrared fluorescence (NIRF and (19F magnetic resonance. Celecoxib loaded nanoemulsions showed a dose dependent uptake in mouse macrophages as measured by (19F NMR and NIRF signal intensities of labeled cells. Dramatic inhibition of intracellular COX-2 enzyme was observed in activated macrophages upon nanoemulsion uptake. COX-2 enzyme inhibition was statistically equivalent between free drug and drug loaded nanoemulsion. However, nanoemulsion mediated drug delivery may be advantageous, helping to avoid systemic exposure to celecoxib and related side effects. Dual molecular imaging signatures of the presented nanoemulsions allow for future in vivo monitoring of the labeled macrophages and may help in examining the role of macrophage COX-2 inhibition in inflammation-cancer interactions. These features strongly support the future use of the presented nanoemulsions as anti-COX-2 theranostic nanomedicine with possible anticancer applications.

Maximum entropy deconvolution of low count nuclear medicine images

International Nuclear Information System (INIS)

McGrath, D.M.

1998-12-01

Maximum entropy is applied to the problem of deconvolving nuclear medicine images, with special consideration for very low count data. The physics of the formation of scintigraphic images is described, illustrating the phenomena which degrade planar estimates of the tracer distribution. Various techniques which are used to restore these images are reviewed, outlining the relative merits of each. The development and theoretical justification of maximum entropy as an image processing technique is discussed. Maximum entropy is then applied to the problem of planar deconvolution, highlighting the question of the choice of error parameters for low count data. A novel iterative version of the algorithm is suggested which allows the errors to be estimated from the predicted Poisson mean values. This method is shown to produce the exact results predicted by combining Poisson statistics and a Bayesian interpretation of the maximum entropy approach. A facility for total count preservation has also been incorporated, leading to improved quantification. In order to evaluate this iterative maximum entropy technique, two comparable methods, Wiener filtering and a novel Bayesian maximum likelihood expectation maximisation technique, were implemented. The comparison of results obtained indicated that this maximum entropy approach may produce equivalent or better measures of image quality than the compared methods, depending upon the accuracy of the system model used. The novel Bayesian maximum likelihood expectation maximisation technique was shown to be preferable over many existing maximum a posteriori methods due to its simplicity of implementation. A single parameter is required to define the Bayesian prior, which suppresses noise in the solution and may reduce the processing time substantially. Finally, maximum entropy deconvolution was applied as a pre-processing step in single photon emission computed tomography reconstruction of low count data. Higher contrast results were

In vitro antibacterial, alpha-amylase inhibition potential of three nudibranchs extracts from South East coast of India

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Giji Sadhasivam

2013-10-01

Full Text Available Objective: To study the antibacterial and antiamylase properties of methanol and acetone extracts of nudibranchs including Bursatella leachii (B. leachii, Kalinga ornata (K. ornata, Aplysia sp. Methods: Crude methanol and acetone extracts of sea slugs were tested for inhibition of fish bacterial pathogens' growth through disc diffusion method. The activity was measured based on the formation of inhibition zone around the disc impregnated with crude extracts. The α-amylase inhibitory effect was also measured calorimetrically. The chemical fingerprinting of the extract was recorded with HPTLC and GC-MS. Results: The solvent extracts of all the three sea slugs showed antibacterial property. The maximum zone of inhibition (>15-20 mm was recorded for methanol and acetone extracts of K. ornata. The methanol extract of Aplysia sp. exhibited 93% inhibition against α-amylase, following by B. leachii (methanol 70.6% and K. ornata (methanol 49.03% inhibition respectively. The acetone extracts didn' t show any notable inhibition. The presence of free amino acids like lysine, aspartic acid, glutamic acid, arginine etc., terpenoids and pigents were confirmed through HPTLC analysis. The presence of siloxanes and propanoic acid were also revealed through GC-MS. Conclusions: This study suggests that further scrutinisation of the B. leachii, K. ornata and Aplysia sp. will pave the way for development of antibacterial and α-amylase inhibitory agent for therapeutic application.

Compound C inhibits macrophage chemotaxis through an AMPK-independent mechanism

Energy Technology Data Exchange (ETDEWEB)

Lee, Youngyi [College of Pharmacy, Woosuk University, Wanju, Jeonbuk 55338 (Korea, Republic of); Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896 (Korea, Republic of); Park, Byung-Hyun, E-mail: bhpark@jbnu.ac.kr [Department of Biochemistry, Chonbuk National University Medical School, Jeonju, Jeonbuk 54896 (Korea, Republic of); Bae, Eun Ju, E-mail: ejbae@woosuk.ac.kr [College of Pharmacy, Woosuk University, Wanju, Jeonbuk 55338 (Korea, Republic of)

2016-01-15

Macrophage infiltration in adipose tissue is a well-established cause of obesity-linked insulin resistance. AMP-activated protein kinase (AMPK) activation in peripheral tissues such as adipose tissue has beneficial effects on the protection against obesity-induced insulin resistance, which is mainly mediated by prevention of adipose tissue macrophage infiltration and inflammation. In examining the role of AMPK on adipose tissue inflammation, we unexpectedly found that compound C (CC), despite its inhibition of AMPK, robustly inhibited macrophage chemotaxis in RAW 264.7 cells when adipocyte conditioned medium (CM) was used as a chemoattractant. Here, we report that CC inhibition of macrophage migration occurred independently of AMPK. Mechanistically, this inhibitory effect of cell migration by CC was mediated by inhibition of the focal adhesion kinase, AKT, nuclear factor κB pathways. Moreover, the expression of chemokine monocyte chemoattractant protein-1 and pro-inflammatory genes such as tumor necrosis factor α and inducible nitric oxide synthase were prevented by CC treatment in RAW 264.7 cells stimulated with either adipocyte CM or lipopolysaccharide. Lastly, in accord with the findings of the anti-inflammatory effect of CC, we demonstrated that CC functioned as a repressor of macrophage CM-mediated insulin resistance in adipocytes. Taken together, our results suggest that CC serves as a useful inhibitory molecule against macrophage chemotaxis into adipose tissue and thus might have therapeutic potential for the treatment of obesity-linked adipose inflammation. - Highlights: • Compound C (CC) inhibits macrophage chemotaxis regardless of AMPK suppression. • CC enhances insulin sensitivity in adipocytes. • CC inhibits focal adhesion kinase, AKT, and NF-κB signaling in RAW 264.7 cells.

Identification of "ever-cropped" land (1984-2010) using Landsat annual maximum NDVI image composites: Southwestern Kansas case study.

Science.gov (United States)

Maxwell, Susan K; Sylvester, Kenneth M

2012-06-01

A time series of 230 intra- and inter-annual Landsat Thematic Mapper images was used to identify land that was ever cropped during the years 1984 through 2010 for a five county region in southwestern Kansas. Annual maximum Normalized Difference Vegetation Index (NDVI) image composites (NDVI(ann-max)) were used to evaluate the inter-annual dynamics of cropped and non-cropped land. Three feature images were derived from the 27-year NDVI(ann-max) image time series and used in the classification: 1) maximum NDVI value that occurred over the entire 27 year time span (NDVI(max)), 2) standard deviation of the annual maximum NDVI values for all years (NDVI(sd)), and 3) standard deviation of the annual maximum NDVI values for years 1984-1986 (NDVI(sd84-86)) to improve Conservation Reserve Program land discrimination.Results of the classification were compared to three reference data sets: County-level USDA Census records (1982-2007) and two digital land cover maps (Kansas 2005 and USGS Trends Program maps (1986-2000)). Area of ever-cropped land for the five counties was on average 11.8 % higher than the area estimated from Census records. Overall agreement between the ever-cropped land map and the 2005 Kansas map was 91.9% and 97.2% for the Trends maps. Converting the intra-annual Landsat data set to a single annual maximum NDVI image composite considerably reduced the data set size, eliminated clouds and cloud-shadow affects, yet maintained information important for discriminating cropped land. Our results suggest that Landsat annual maximum NDVI image composites will be useful for characterizing land use and land cover change for many applications.

Phytochemical Screening, Alpha-Glucosidase Inhibition, Antibacterial and Antioxidant Potential of Ajuga bracteosa Extracts.

Science.gov (United States)

Hafeez, Kokab; Andleeb, Saiqa; Ghousa, Tahseen; Mustafa, Rozina G; Naseer, Anum; Shafique, Irsa; Akhter, Kalsoom

2017-01-01

Ajuga bracteosa, a medicinal herb, is used by local community to cure a number of diseases such as inflammation, jaundice bronchial asthma, cancer and diabetes. The aim of present work was to evaluate the antioxidant potential, in vitro antidiabetic and antimicrobial effects of A. bracteosa. n-hexane, ethyl acetate, chloroform, acetone, methanol and aqueous extracts of Ajuga bracteosa roots, were prepared via maceration. Antibacterial activity was carried out by agar well diffusion method. Quantitative and qualitative phytochemical screening was done. The antioxidant activity was determined by iron (II) chelating activity, iron reducing power, DPPH, and ABTS free radical scavenging methods, Antidiabetic activity was evaluated through inhibition of α-glucosidase assay. Phytochemical analysis showed the presence of phenols, flavonoids, tannins, saponins, quinines, terpenoids, xanthoproteins, glycosides, carbohydrates, steroids, phytosterols and amino acids. DPPH and ABTS potential values were recorded as 61.92% to 88.84% and 0.11% to 38.82%, respectively. Total phenolic and total flavonoid contents were expressed as gallic acid and rutin equivalents. Total iron content was expressed as FeSO4 equivalents. Chloroform and n-hexane extracts showed significant enzyme inhibition potential with IC50 values of 29.92 μg/ml and 131.7 μg/ml respectively. Aqueous extract showed maximum inhibition of E. coli, S. typhimurium, E. amnigenus, S. pyogenes, and S. aureus, (18.0±1.0 mm, 12.5±0.7 mm, 17.0±0.0 mm, 11.0±0.0 mm and 15.3±2.0 mm mm), respectively. Similarly, n-hexane extract showed maximum inhibition of E. coli, E. amnigenus, S. aureus (11.6±1.5 mm; 11.3±1.5 mm; 13.3±0.5 mm). This study also shows that n-hexane, chloroform, ethyl acetate and aqueous extracts of A. bracteosa root possess α-glucosidase inhibitory activities and therefore it may be used as hypoglycemic agents in the management of postprandial hyperglycemia. Ajuga bracteosa root extracts may provide a

RTEL1 Inhibits Trinucleotide Repeat Expansions and Fragility

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Aisling Frizzell

2014-03-01

Full Text Available Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG⋅CAG repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vitro. The expansion-blocking activity of RTEL1 also required Rad18 and HLTF, homologs of yeast Rad18 and Rad5. These findings are reminiscent of budding yeast Srs2, which inhibits expansions, unwinds hairpins, and prevents triplet-repeat-induced chromosome fragility. Accordingly, we found expansions and fragility were suppressed in yeast srs2 mutants expressing RTEL1, but not Fbh1. We propose that RTEL1 serves as a human analog of Srs2 to inhibit (CTG⋅CAG repeat expansions and fragility, likely by unwinding problematic hairpins.

Fast inhibition of glutamate-activated currents by caffeine.

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Nicholas P Vyleta

Full Text Available BACKGROUND: Caffeine stimulates calcium-induced calcium release (CICR in many cell types. In neurons, caffeine stimulates CICR presynaptically and thus modulates neurotransmitter release. METHODOLOGY/PRINCIPAL FINDINGS: Using the whole-cell patch-clamp technique we found that caffeine (20 mM reversibly increased the frequency and decreased the amplitude of miniature excitatory postsynaptic currents (mEPSCs in neocortical neurons. The increase in mEPSC frequency is consistent with a presynaptic mechanism. Caffeine also reduced exogenously applied glutamate-activated currents, confirming a separate postsynaptic action. This inhibition developed in tens of milliseconds, consistent with block of channel currents. Caffeine (20 mM did not reduce currents activated by exogenous NMDA, indicating that caffeine block is specific to non-NMDA type glutamate receptors. CONCLUSIONS/SIGNIFICANCE: Caffeine-induced inhibition of mEPSC amplitude occurs through postsynaptic block of non-NMDA type ionotropic glutamate receptors. Caffeine thus has both pre and postsynaptic sites of action at excitatory synapses.

Maximum Principles for Discrete and Semidiscrete Reaction-Diffusion Equation

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Petr Stehlík

2015-01-01

Full Text Available We study reaction-diffusion equations with a general reaction function f on one-dimensional lattices with continuous or discrete time ux′  (or  Δtux=k(ux-1-2ux+ux+1+f(ux, x∈Z. We prove weak and strong maximum and minimum principles for corresponding initial-boundary value problems. Whereas the maximum principles in the semidiscrete case (continuous time exhibit similar features to those of fully continuous reaction-diffusion model, in the discrete case the weak maximum principle holds for a smaller class of functions and the strong maximum principle is valid in a weaker sense. We describe in detail how the validity of maximum principles depends on the nonlinearity and the time step. We illustrate our results on the Nagumo equation with the bistable nonlinearity.

Selective translational repression of HIV-1 RNA by Sam68DeltaC occurs by altering PABP1 binding to unspliced viral RNA

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Soros Vanessa

2008-10-01

Full Text Available Abstract HIV-1 structural proteins are translated from incompletely spliced 9 kb and 4 kb mRNAs, which are transported to the cytoplasm by Crm1. It has been assumed that once in the cytoplasm, translation of incompletely spliced HIV-1 mRNAs occurs in the same manner as host mRNAs. Previous analyses have demonstrated that Sam68 and a mutant thereof, Sam68ΔC, have dramatic effects on HIV gene expression, strongly enhancing and inhibiting viral structural protein synthesis, respectively. While investigating the inhibition of incompletely spliced HIV-1 mRNAs by Sam68ΔC, we determined that the effect was independent of the perinuclear bundling of the viral RNA. Inhibition was dependent upon the nuclear export pathway used, as translation of viral RNA exported via the Tap/CTE export pathway was not blocked by Sam68ΔC. We demonstrate that inhibition of HIV expression by Sam68ΔC is correlated with a loss of PABP1 binding with no attendant change in polyadenosine tail length of the affected RNAs. The capacity of Sam68ΔC to selectively inhibit translation of HIV-1 RNAs exported by Crm1 suggests that it is able to recognize unique characteristics of these viral RNPs, a property that could lead to new therapeutic approaches to controlling HIV-1 replication.

Minimal length, Friedmann equations and maximum density

Energy Technology Data Exchange (ETDEWEB)

Awad, Adel [Center for Theoretical Physics, British University of Egypt,Sherouk City 11837, P.O. Box 43 (Egypt); Department of Physics, Faculty of Science, Ain Shams University,Cairo, 11566 (Egypt); Ali, Ahmed Farag [Centre for Fundamental Physics, Zewail City of Science and Technology,Sheikh Zayed, 12588, Giza (Egypt); Department of Physics, Faculty of Science, Benha University,Benha, 13518 (Egypt)

2014-06-16

Inspired by Jacobson’s thermodynamic approach, Cai et al. have shown the emergence of Friedmann equations from the first law of thermodynamics. We extend Akbar-Cai derivation http://dx.doi.org/10.1103/PhysRevD.75.084003 of Friedmann equations to accommodate a general entropy-area law. Studying the resulted Friedmann equations using a specific entropy-area law, which is motivated by the generalized uncertainty principle (GUP), reveals the existence of a maximum energy density closed to Planck density. Allowing for a general continuous pressure p(ρ,a) leads to bounded curvature invariants and a general nonsingular evolution. In this case, the maximum energy density is reached in a finite time and there is no cosmological evolution beyond this point which leaves the big bang singularity inaccessible from a spacetime prospective. The existence of maximum energy density and a general nonsingular evolution is independent of the equation of state and the spacial curvature k. As an example we study the evolution of the equation of state p=ωρ through its phase-space diagram to show the existence of a maximum energy which is reachable in a finite time.

Maximum-Entropy Inference with a Programmable Annealer

Science.gov (United States)

Chancellor, Nicholas; Szoke, Szilard; Vinci, Walter; Aeppli, Gabriel; Warburton, Paul A.

2016-03-01

Optimisation problems typically involve finding the ground state (i.e. the minimum energy configuration) of a cost function with respect to many variables. If the variables are corrupted by noise then this maximises the likelihood that the solution is correct. The maximum entropy solution on the other hand takes the form of a Boltzmann distribution over the ground and excited states of the cost function to correct for noise. Here we use a programmable annealer for the information decoding problem which we simulate as a random Ising model in a field. We show experimentally that finite temperature maximum entropy decoding can give slightly better bit-error-rates than the maximum likelihood approach, confirming that useful information can be extracted from the excited states of the annealer. Furthermore we introduce a bit-by-bit analytical method which is agnostic to the specific application and use it to show that the annealer samples from a highly Boltzmann-like distribution. Machines of this kind are therefore candidates for use in a variety of machine learning applications which exploit maximum entropy inference, including language processing and image recognition.

Tissue transglutaminase inhibits the TRPV5-dependent calcium transport in an N-glycosylation-dependent manner

DEFF Research Database (Denmark)

Boros, Sandor; Xi, Qi; Dimke, Henrik Anthony

2011-01-01

Tissue transglutaminase (tTG) is a multifunctional Ca(2+)-dependent enzyme, catalyzing protein crosslinking. The transient receptor potential vanilloid (TRPV) family of cation channels was recently shown to contribute to the regulation of TG activities in keratinocytes and hence skin barrier form......, these observations imply that tTG is a novel extracellular enzyme inhibiting the activity of TRPV5. The inhibition of TRPV5 occurs in an N-glycosylation-dependent manner, signifying a common final pathway by which distinct extracellular factors regulate channel activity....

Class I HDAC inhibition is a novel pathway for regulating astrocytic apoE secretion.

Science.gov (United States)

Dresselhaus, Erica; Duerr, James M; Vincent, Fabien; Sylvain, Emily K; Beyna, Mercedes; Lanyon, Lorraine F; LaChapelle, Erik; Pettersson, Martin; Bales, Kelly R; Ramaswamy, Gayathri

2018-01-01

Despite the important role of apolipoprotein E (apoE) secretion from astrocytes in brain lipid metabolism and the strong association of apoE4, one of the human apoE isoforms, with sporadic and late onset forms of Alzheimer's disease (AD) little is known about the regulation of astrocytic apoE. Utilizing annotated chemical libraries and a phenotypic screening strategy that measured apoE secretion from a human astrocytoma cell line, inhibition of pan class I histone deacetylases (HDACs) was identified as a mechanism to increase apoE secretion. Knocking down select HDAC family members alone or in combination revealed that inhibition of the class I HDAC family was responsible for enhancing apoE secretion. Knocking down LXRα and LXRβ genes revealed that the increase in astrocytic apoE in response to HDAC inhibition occurred via an LXR-independent pathway. Collectively, these data suggest that pan class I HDAC inhibition is a novel pathway for regulating astrocytic apoE secretion.

The role of organic load and ammonia inhibition in anaerobic digestion of tannery fleshing

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Cecilia Polizzi

2018-06-01

Full Text Available In this study, batch tests on anaerobic digestion of tannery fleshing (skin-residue waste from hides’ tanning process, as sole substrate, have been performed with the purpose of assessing the effects of high substrate concentration and consequent ammonia inhibition on the process. Co-digestion with tannery primary sludge was also evaluated. According to the results, no inhibition occurred at initial organic load up to 5 gVS/l; an inhibited steady state was observed at 10 gVS/l, and system failure and instability was showed at the highest load of 20 gVS/l. Co-digestion with tannery primary sludge proved feasible, probably due to dilution effect. The observed ammonia and VFA accumulation over the experimental time-lapse is also discussed. Results are intended to increase knowledge on the technological application of anaerobic digestion of sole tannery fleshing, in the perspective of its application as on-site treatment solution for decentralised tanneries. Keywords: Anaerobic digestion, Tannery waste, Ammonia inhibition, Organic load

Comparative analysis of adsorption and corrosion inhibitive properties of ethanol extract of Dialium Guineense leaves for mild steel in 0.5 M HCl

OpenAIRE

Shola Elijah Adeniji; Bamigbola Abiola Akindehinde

2018-01-01

Adsorption and corrosion inhibitive properties of ethanol extract of Dialium guineense leaves for mild steel in 0.5M HCl was studied using the gravimetric method. The results showed that the ethanol extract of Dialium guineense leaves is a good corrosion inhibitor for mild steel in 0.5 M HCl. The inhibition efficiency was found to increase with increase in the concentration of ethanol extract of Dialium guineense leaves up to the maximum of 92 %, but at the same time it decreased as the tempe...

Probabilistic maximum-value wind prediction for offshore environments

DEFF Research Database (Denmark)

Staid, Andrea; Pinson, Pierre; Guikema, Seth D.

2015-01-01

statistical models to predict the full distribution of the maximum-value wind speeds in a 3 h interval. We take a detailed look at the performance of linear models, generalized additive models and multivariate adaptive regression splines models using meteorological covariates such as gust speed, wind speed......, convective available potential energy, Charnock, mean sea-level pressure and temperature, as given by the European Center for Medium-Range Weather Forecasts forecasts. The models are trained to predict the mean value of maximum wind speed, and the residuals from training the models are used to develop...... the full probabilistic distribution of maximum wind speed. Knowledge of the maximum wind speed for an offshore location within a given period can inform decision-making regarding turbine operations, planned maintenance operations and power grid scheduling in order to improve safety and reliability...

Characterizing graphs of maximum matching width at most 2

DEFF Research Database (Denmark)

Jeong, Jisu; Ok, Seongmin; Suh, Geewon

2017-01-01

The maximum matching width is a width-parameter that is de ned on a branch-decomposition over the vertex set of a graph. The size of a maximum matching in the bipartite graph is used as a cut-function. In this paper, we characterize the graphs of maximum matching width at most 2 using the minor o...

Microbial diversity from chlorophyll maximum, oxygen minimum and bottom zones in the southwestern Atlantic Ocean

Science.gov (United States)

Medina-Silva, Renata; de Oliveira, Rafael R.; Pivel, Maria A. G.; Borges, Luiz G. A.; Simão, Taiz L. L.; Pereira, Leandro M.; Trindade, Fernanda J.; Augustin, Adolpho H.; Valdez, Fernanda P.; Eizirik, Eduardo; Utz, Laura R. P.; Groposo, Claudia; Miller, Dennis J.; Viana, Adriano R.; Ketzer, João M. M.; Giongo, Adriana

2018-02-01

Conspicuous physicochemical vertical stratification in the deep sea is one of the main forces driving microbial diversity in the oceans. Oxygen and sunlight availability are key factors promoting microbial diversity throughout the water column. Ocean currents also play a major role in the physicochemical stratification, carrying oxygen down to deeper zones as well as moving deeper water masses up towards shallower depths. Water samples within a 50-km radius in a pockmark location of the southwestern Atlantic Ocean were collected and the prokaryotic communities from different water depths - chlorophyll maximum, oxygen minimum and deep-sea bottom (down to 1355 m) - were described. At phylum level, Proteobacteria were the most frequent in all water depths, Cyanobacteria were statistically more frequent in chlorophyll maximum zone, while Thaumarchaeota were significantly more abundant in both oxygen minimum and bottom waters. The most frequent microorganism in the chlorophyll maximum and oxygen minimum zones was a Pelagibacteraceae operational taxonomic unit (OTU). At the bottom, the most abundant genus was the archaeon Nitrosopumilus. Beta diversity analysis of the 16S rRNA gene sequencing data uncovered in this study shows high spatial heterogeneity among water zones communities. Our data brings important contribution for the characterisation of oceanic microbial diversity, as it consists of the first description of prokaryotic communities occurring in different oceanic water zones in the southwestern Atlantic Ocean.

Metabolic interactions between acetaminophen (paracetamol) and two flavonoids, luteolin and quercetin, through in-vitro inhibition studies.

Science.gov (United States)

Cao, Lei; Kwara, Awewura; Greenblatt, David J

2017-12-01

Excessive exposure to acetaminophen (APAP, paracetamol) can cause liver injury through formation of a reactive metabolite that depletes hepatic glutathione and causes hepatocellular oxidative stress and damage. Generation of this metabolite is mediated by Cytochrome-P450 (CYP) isoforms, mainly CYP2E1. A number of naturally occurring flavonoids can mitigate APAP-induced hepatotoxicity in experimental animal models. Our objective was to determine the mechanism of these protective effects and to evaluate possible human applicability. Two flavonoids, luteolin and quercetin, were evaluated as potential inhibitors of eight human CYP isoforms, of six UDP-glucuronosyltransferase (UGT) isoforms and of APAP glucuronidation and sulfation. The experimental model was based on in-vitro metabolism by human liver microsomes, using isoform-specific substrates. Luteolin and quercetin inhibited human CYP isoforms to varying degrees, with greatest potency towards CYP1A2 and CYP2C8. However, 50% inhibitory concentrations (IC 50 values) were generally in the micromolar range. UGT isoforms were minimally inhibited. Both luteolin and quercetin inhibited APAP sulfation but not glucuronidation. Inhibition of human CYP activity by luteolin and quercetin occurred with IC 50 values exceeding customary in-vivo human exposure with tolerable supplemental doses of these compounds. The findings indicate that luteolin and quercetin are not likely to be of clinical value for preventing or treating APAP-induced hepatotoxicity. © 2017 Royal Pharmaceutical Society.

The Maximum Resource Bin Packing Problem

DEFF Research Database (Denmark)

Boyar, J.; Epstein, L.; Favrholdt, L.M.

2006-01-01

Usually, for bin packing problems, we try to minimize the number of bins used or in the case of the dual bin packing problem, maximize the number or total size of accepted items. This paper presents results for the opposite problems, where we would like to maximize the number of bins used...... algorithms, First-Fit-Increasing and First-Fit-Decreasing for the maximum resource variant of classical bin packing. For the on-line variant, we define maximum resource variants of classical and dual bin packing. For dual bin packing, no on-line algorithm is competitive. For classical bin packing, we find...

Maximum entropy analysis of EGRET data

DEFF Research Database (Denmark)

Pohl, M.; Strong, A.W.

1997-01-01

EGRET data are usually analysed on the basis of the Maximum-Likelihood method \\cite{ma96} in a search for point sources in excess to a model for the background radiation (e.g. \\cite{hu97}). This method depends strongly on the quality of the background model, and thus may have high systematic unce...... uncertainties in region of strong and uncertain background like the Galactic Center region. Here we show images of such regions obtained by the quantified Maximum-Entropy method. We also discuss a possible further use of MEM in the analysis of problematic regions of the sky....

Density estimation by maximum quantum entropy

International Nuclear Information System (INIS)

Silver, R.N.; Wallstrom, T.; Martz, H.F.

1993-01-01

A new Bayesian method for non-parametric density estimation is proposed, based on a mathematical analogy to quantum statistical physics. The mathematical procedure is related to maximum entropy methods for inverse problems and image reconstruction. The information divergence enforces global smoothing toward default models, convexity, positivity, extensivity and normalization. The novel feature is the replacement of classical entropy by quantum entropy, so that local smoothing is enforced by constraints on differential operators. The linear response of the estimate is proportional to the covariance. The hyperparameters are estimated by type-II maximum likelihood (evidence). The method is demonstrated on textbook data sets

Effect of inhibition of microsomal Ca(2+)-ATPase on cytoplasmic calcium and enzyme secretion in pancreatic acini.

Science.gov (United States)

Metz, D C; Pradhan, T K; Mrozinski, J E; Jensen, R T; Turner, R J; Patto, R J; Gardner, J D

1994-01-13

We used thapsigargin (TG), 2,5-di-tert-butyl-1,4-benzohydroquinone (BHQ) and cyclopiazonic acid (CPA), each of which inhibits microsomal Ca(2+)-ATPase, to evaluate the effects of this inhibition on cytoplasmic free calcium ([Ca2+]i) and secretagogue-stimulated enzyme secretion in rat pancreatic acini. Using single-cell microspectrofluorimetry of fura-2-loaded acini we found that all three agents caused a sustained increase in [Ca2+]i by mobilizing calcium from inositol-(1,4,5)-trisphosphate-sensitive intracellular calcium stores and by promoting influx of extracellular calcium. Concentrations of all three agents that increased [Ca2+]i potentiated the stimulation of enzyme secretion caused by secretagogues that activate adenylate cyclase but inhibited the stimulation of enzyme secretion caused by secretagogues that activate phospholipase C. With BHQ, potentiation of adenylate cyclase-mediated enzyme secretion occurred immediately whereas inhibition of phospholipase C-mediated enzyme secretion occurred only after several min of incubation. In addition, the effects of BHQ and CPA on both [Ca2+]i and secretagogue-stimulated enzyme secretion were reversed completely by washing whereas the actions of TG could not be reversed by washing. Concentrations of BHQ in excess of those that caused maximal changes in [Ca2+]i inhibited all modes of stimulated enzyme secretion by a mechanism that was apparently unrelated to changes in [Ca2+]i. Finally, in contrast to the findings with TG and BHQ, CPA inhibited bombesin-stimulated enzyme secretion over a range of concentrations that was at least 10-fold lower than the range of concentrations over which CPA potentiated VIP-stimulated enzyme secretion.

Aptamer-Conjugated Calcium Phosphate Nanoparticles for Reducing Diabetes Risk via Retinol Binding Protein 4 Inhibition.

Science.gov (United States)

Torabi, Raheleh; Ghourchian, Hedayatollah; Amanlou, Massoud; Pasalar, Parvin

2017-06-01

Inhibition of the binding of retinol to its carrier, retinol binding protein 4, is a new strategy for treating type 2 diabetes; for this purpose, we have provided an aptamer-functionalized multishell calcium phosphate nanoparticle. First, calcium phosphate nanoparticles were synthesized and conjugated to the aptamer. The cytotoxicity of nanoparticles releases the process of aptamer from nanoparticles and their inhibition function of binding retinol to retinol binding protein 4. After synthesizing and characterizing the multishell calcium phosphate nanoparticles and observing the noncytotoxicity of conjugate, the optimum time (48 hours) and the pH (7.4) for releasing the aptamer from the nanoparticles was determined. The half-maximum inhibitory concentration (IC 50 ) value for inhibition of retinol binding to retinol binding protein 4 was 210 femtomolar (fmol). The results revealed that the aptamer could prevent connection between retinol and retinol binding protein 4 at a very low IC 50 value (210 fmol) compared to other reported inhibitors. It seems that this aptamer could be used as an efficient candidate not only for decreasing the insulin resistance in type 2 diabetes, but also for inhibiting the other retinol binding protein 4-related diseases. Copyright © 2017 Diabetes Canada. Published by Elsevier Inc. All rights reserved.

Leaf Dynamics of Panicum maximum under Future Climatic Changes.

Science.gov (United States)

Britto de Assis Prado, Carlos Henrique; Haik Guedes de Camargo-Bortolin, Lívia; Castro, Érique; Martinez, Carlos Alberto

2016-01-01

Panicum maximum Jacq. 'Mombaça' (C4) was grown in field conditions with sufficient water and nutrients to examine the effects of warming and elevated CO2 concentrations during the winter. Plants were exposed to either the ambient temperature and regular atmospheric CO2 (Control); elevated CO2 (600 ppm, eC); canopy warming (+2°C above regular canopy temperature, eT); or elevated CO2 and canopy warming (eC+eT). The temperatures and CO2 in the field were controlled by temperature free-air controlled enhancement (T-FACE) and mini free-air CO2 enrichment (miniFACE) facilities. The most green, expanding, and expanded leaves and the highest leaf appearance rate (LAR, leaves day(-1)) and leaf elongation rate (LER, cm day(-1)) were observed under eT. Leaf area and leaf biomass were higher in the eT and eC+eT treatments. The higher LER and LAR without significant differences in the number of senescent leaves could explain why tillers had higher foliage area and leaf biomass in the eT treatment. The eC treatment had the lowest LER and the fewest expanded and green leaves, similar to Control. The inhibitory effect of eC on foliage development in winter was indicated by the fewer green, expanded, and expanding leaves under eC+eT than eT. The stimulatory and inhibitory effects of the eT and eC treatments, respectively, on foliage raised and lowered, respectively, the foliar nitrogen concentration. The inhibition of foliage by eC was confirmed by the eC treatment having the lowest leaf/stem biomass ratio and by the change in leaf biomass-area relationships from linear or exponential growth to rectangular hyperbolic growth under eC. Besides, eC+eT had a synergist effect, speeding up leaf maturation. Therefore, with sufficient water and nutrients in winter, the inhibitory effect of elevated CO2 on foliage could be partially offset by elevated temperatures and relatively high P. maximum foliage production could be achieved under future climatic change.

Beta-lactam antibiotic-induced platelet dysfunction: Evidence for irreversible inhibition of platelet activation in vitro and in vivo after prolonged exposure to penicillin

International Nuclear Information System (INIS)

Burroughs, S.F.; Johnson, G.J.

1990-01-01

beta-Lactam antibiotics cause platelet dysfunction with bleeding complications. Previous in vitro studies documented reversible inhibition of agonist-receptor interaction. This mechanism is inadequate to explain the effect of beta-lactam antibiotics in vivo. Platelet function does not return to normal immediately after drug treatment, implying irreversible inhibition of platelet function. We report here evidence of irreversible platelet functional and biochemical abnormalities after in vitro and in vivo exposure to beta-lactam antibiotics. Irreversible binding of [14C]-penicillin (Pen) occurred in vitro. After 24 hours' in vitro incubation with 10 to 20 mmol/L Pen, or ex vivo after antibiotic treatment, irreversible functional impairment occurred; but no irreversible inhibition of alpha 2 adrenergic receptors, measured with [3H]-yohimbine, or high-affinity thromboxane A2/prostaglandin H2 (TXA2/PGH2) receptors, measured with agonist [3H]-U46619 and antagonist [3H]-SQ29548, occurred. However, low-affinity platelet TXA2/PGH2 receptors were decreased 40% after Pen exposure in vitro or in vivo, indicating irreversible membrane alteration. Two postreceptor biochemical events were irreversibly inhibited in platelets incubated with Pen for 24 hours in vitro or ex vivo after antibiotic treatment. Thromboxane synthesis was inhibited 28.3% to 81.7%. Agonist-induced rises in cytosolic calcium ([Ca2+]i) were inhibited 40.1% to 67.5% in vitro and 26.6% to 52.2% ex vivo. Therefore, Pen binds to platelets after prolonged exposure, resulting in irreversible dysfunction attributable to inhibition of TXA2 synthesis and impairment of the rise in [Ca2+]i. The loss of low-affinity TXA2/PGH2 receptors suggests that the primary site of action of these drugs is on the platelet membrane

Boron neutron capture therapy (BNCT) inhibits tumor development from precancerous tissue: An experimental study that supports a potential new application of BNCT

International Nuclear Information System (INIS)

Monti Hughes, A.; Heber, E.M.; Pozzi, E.; Nigg, D.W.; Calzetta, O.; Blaumann, H.; Longhino, J.; Nievas, S.I.; Aromando, R.F.; Itoiz, M.E.; Trivillin, V.A.; Schwint, A.E.

2009-01-01

We previously demonstrated the efficacy of boron neutron capture therapy (BNCT) mediated by boronophenylalanine (BPA), GB-10 (Na 2 10 B 10 H 10 ) and (GB-10+BPA) to control tumors, with no normal tissue radiotoxicity, in the hamster cheek pouch oral cancer model. Herein we developed a novel experimental model of field-cancerization and precancerous lesions (globally termed herein precancerous tissue) in the hamster cheek pouch to explore the long-term potential inhibitory effect of the same BNCT protocols on the development of second primary tumors from precancerous tissue. Clinically, second primary tumor recurrences occur in field-cancerized tissue, causing therapeutic failure. We performed boron biodistribution studies followed by in vivo BNCT studies, with 8 months follow-up. All 3 BNCT protocols induced a statistically significant reduction in tumor development from precancerous tissue, reaching a maximum inhibition of 77-100%. The inhibitory effect of BPA-BNCT and (GB-10+BPA)-BNCT persisted at 51% at the end of follow-up (8 months), whereas for GB-10-BNCT it faded after 2 months. Likewise, beam-only elicited a significant but transient reduction in tumor development. No normal tissue radiotoxicity was observed. At 8 months post-treatment with BPA-BNCT or (GB-10+BPA)-BNCT, the precancerous pouches that did not develop tumors had regained the macroscopic and histological appearance of normal (non-cancerized) pouches. A potential new clinical application of BNCT would lie in its capacity to inhibit local regional recurrences.

Boron neutron capture therapy (BNCT) inhibits tumor development from precancerous tissue: An experimental study that supports a potential new application of BNCT

Energy Technology Data Exchange (ETDEWEB)

Monti Hughes, A.; Heber, E.M. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Pozzi, E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Department of Research and Production Reactors, Ezeiza Atomic Center, CNEA, Buenos Aires (Argentina); Nigg, D.W. [Idaho National Laboratory, Idaho Falls, Idaho (United States); Calzetta, O.; Blaumann, H.; Longhino, J. [Department of Nuclear Engineering, Bariloche Atomic Center, CNEA, Rio Negro (Argentina); Nievas, S.I. [Department of Chemistry, CNEA, Buenos Aires (Argentina); Aromando, R.F. [Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires, Buenos Aires (Argentina); Itoiz, M.E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires, Buenos Aires (Argentina); Trivillin, V.A. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina); Schwint, A.E. [Department of Radiobiology, National Atomic Energy Commission (CNEA), Buenos Aires (Argentina)], E-mail: schwint@cnea.gov.ar

2009-07-15

We previously demonstrated the efficacy of boron neutron capture therapy (BNCT) mediated by boronophenylalanine (BPA), GB-10 (Na{sub 2}{sup 10}B{sub 10}H{sub 10}) and (GB-10+BPA) to control tumors, with no normal tissue radiotoxicity, in the hamster cheek pouch oral cancer model. Herein we developed a novel experimental model of field-cancerization and precancerous lesions (globally termed herein precancerous tissue) in the hamster cheek pouch to explore the long-term potential inhibitory effect of the same BNCT protocols on the development of second primary tumors from precancerous tissue. Clinically, second primary tumor recurrences occur in field-cancerized tissue, causing therapeutic failure. We performed boron biodistribution studies followed by in vivo BNCT studies, with 8 months follow-up. All 3 BNCT protocols induced a statistically significant reduction in tumor development from precancerous tissue, reaching a maximum inhibition of 77-100%. The inhibitory effect of BPA-BNCT and (GB-10+BPA)-BNCT persisted at 51% at the end of follow-up (8 months), whereas for GB-10-BNCT it faded after 2 months. Likewise, beam-only elicited a significant but transient reduction in tumor development. No normal tissue radiotoxicity was observed. At 8 months post-treatment with BPA-BNCT or (GB-10+BPA)-BNCT, the precancerous pouches that did not develop tumors had regained the macroscopic and histological appearance of normal (non-cancerized) pouches. A potential new clinical application of BNCT would lie in its capacity to inhibit local regional recurrences.

Analogue of Pontryagin's maximum principle for multiple integrals minimization problems

OpenAIRE

Mikhail, Zelikin

2016-01-01

The theorem like Pontryagin's maximum principle for multiple integrals is proved. Unlike the usual maximum principle, the maximum should be taken not over all matrices, but only on matrices of rank one. Examples are given.

Human erythrocytes inhibit complement-mediated solubilization of immune complexes by human serum

International Nuclear Information System (INIS)

Dorval, B.L.

1987-01-01

The aim of this study was to develop an autologus human system to evaluate the effects of human erythrocytes on solubilization of immune complex precipitates (IC) by human serum. Incubation of IC with fresh human serum or guinea pig serum resulted in solubilization of IC. When packed erythrocytes were added to human serum or guinea pig serum binding of IC to the erythrocyte occurred and IC solubilization was inhibited significantly (p <.025). Sheep erythrocytes did not bind IC or inhibit IC solubilization. To evaluate the role of human erythrocyte complement receptor (CR1) on these findings, human erythrocytes were treated with trypsin or anti-CR1 antibodies. Both treatments abrogated IC binding to human erythrocytes but did not affect the ability of the human erythrocyte to inhibit IC solubilization. Radioimmunoassay was used to measure C3, C4 and C5 activation in human serum after incubation with IC, human erythrocytes, human erythrocytes plus IC, whole blood or in whole blood plus IC

Mud Flow Characteristics Occurred in Izuoshima Island, 2013

Science.gov (United States)

Takebayashi, H.; Egashira, S.; Fujita, M.

2015-12-01

Landslides and mud flows were occurred in the west part of the Izuoshima Island, Japan on 16 October 2013. The Izuoshima Island is a volcanic island and the land surface is covered by the volcanic ash sediment in 1m depth. Hence, the mud flow with high sediment concentration was formed. The laminar layer is formed in the debris flow from the bed to the fluid surface. On the other hand, the laminar flow is restricted near the bed in the mud flow and the turbulence flow is formed on the laminar flow layer. As a result, the equilibrium slope of the mud flow becomes smaller comparing to the debris flow. In this study, the numerical analysis mud flow model considering the effect of turbulence flow on the equilibrium slope of the mud flow is developed. Subsequently, the model is applied to the mud flow occurred in the Izuoshima Island and discussed the applicability of the model and the flow characteristics of the mud flow. The differences of the horizontal flow areas between the simulated results and the field data are compared and it was found that the outline of the horizontal shape of the flow areas is reproduced well. Furthermore, the horizontal distribution of the erosion and deposition area is reproduced by the numerical analysis well except for the residential area (Kandachi area). Kandachi area is judged as the erosion area by the field observation, but the sediment was deposited in the numerical analysis. It is considered that the 1.5hour heavy rain over 100mm/h after the mud flow makes the discrepancy. The difference of the horizontal distribution of the maximum flow surface elevation between the simulated results and the field data are compared and it was found that the simulated flow depth is overestimated slightly, because of the wider erosion area due to the coarse resolution elevation data. The averaged velocity and the depth of the mud flow was enough large to collapse the houses.

Maximum entropy reconstructions for crystallographic imaging; Cristallographie et reconstruction d`images par maximum d`entropie

Energy Technology Data Exchange (ETDEWEB)

Papoular, R

1997-07-01

The Fourier Transform is of central importance to Crystallography since it allows the visualization in real space of tridimensional scattering densities pertaining to physical systems from diffraction data (powder or single-crystal diffraction, using x-rays, neutrons, electrons or else). In turn, this visualization makes it possible to model and parametrize these systems, the crystal structures of which are eventually refined by Least-Squares techniques (e.g., the Rietveld method in the case of Powder Diffraction). The Maximum Entropy Method (sometimes called MEM or MaxEnt) is a general imaging technique, related to solving ill-conditioned inverse problems. It is ideally suited for tackling undetermined systems of linear questions (for which the number of variables is much larger than the number of equations). It is already being applied successfully in Astronomy, Radioastronomy and Medical Imaging. The advantages of using MAXIMUM Entropy over conventional Fourier and `difference Fourier` syntheses stem from the following facts: MaxEnt takes the experimental error bars into account; MaxEnt incorporate Prior Knowledge (e.g., the positivity of the scattering density in some instances); MaxEnt allows density reconstructions from incompletely phased data, as well as from overlapping Bragg reflections; MaxEnt substantially reduces truncation errors to which conventional experimental Fourier reconstructions are usually prone. The principles of Maximum Entropy imaging as applied to Crystallography are first presented. The method is then illustrated by a detailed example specific to Neutron Diffraction: the search for proton in solids. (author). 17 refs.

Synthesis, characterization and corrosion inhibition properties of benzamide-2-chloro-4-nitrobenzoic acid and anthranilic acid-2-chloro-4-nitrobenzoic acid for mild steel corrosion in acidic medium

Science.gov (United States)

Pandey, Archana; Verma, Chandrabhan; Singh, B.; Ebenso, Eno E.

2018-03-01

The present study deals with the synthesis of two new compounds namely, benzamide - 2-chloro-4-nitrobenzoic acid (BENCNBA) and anthranilic acid-2-chloro-4-nitrobenzoic acid (AACNBA) using solid phase reactions. The phase diagram studies revealed that formation of the investigated compounds occurs in 1:1 molar ratio. The synthesized compounds were characterized using several spectral techniques such as FT-IR, 1H and 13C NMR, UV-Vis, powder X-ray diffraction (PXRD). Single crystal XRD (SCXRD) study showed that both BENCNBA and AACNBA compounds crystallize in triclinic crystal system with P-1 space group. Further, the presence of intermolecular hydrogen bonding between the constituent components was also supported by single crystal X-ray diffraction (SCXRD) method. Heat of mixing, entropy of fusion, roughness parameter, interfacial energy and excess thermodynamic functions have also been computed using the enthalpy of fusion values derived from differential scanning calorimeter (DSC) study. The inhibition effect of BENCNBA and AACNBA on the mild steel corrosion in hydrochloric acid solution was tested using electrochemical methods. Electrochemical impedance spectroscopy (EIS) study revealed that both BENCNBA and AACNBA behaved as interface corrosion inhibitors and showed maximum inhibition efficiencies of 95.71% and 96.42%, respectively at 400 ppm (1.23 × 10-3 M) concentration. Potentiodynamic polarization (PDP) measurements suggested that BENCNBA and AACNBA acted as mixed type corrosion inhibitors. EIS and PDP results showed that BENCNBA and AACNBA act as efficient corrosion inhibitors for mild steel and their inhibition efficiencies enhances on increasing their concentrations.

Electrical discharge occurring between a negatively charged particle cloud and a grounded sphere electrode

International Nuclear Information System (INIS)

Higashiyama, Y; Migita, S; Toki, K; Sugimoto, T

2008-01-01

Electrostatic discharge occurring between a space-charge cloud and a grounded object was investigated using a large-scale charged particle cloud formed by using three set of cloud generators consisting of a blower and corona charger. The ejecting velocity of the particles affects the formation of the charged cloud. At the lower velocity, the charged cloud spread due to electrostatic repulsion force, while at the higher velocity cloud forms an elongated conical shape. To cause electrostatic discharge between the cloud and a grounded object, a grounded sphere electrode with 100 mm in diameter was set at the inside or outside of the cloud. The brush-like discharge channels reached the maximum length of 0.55 m. The discharge current has a waveform with single or multi-peak, a current peak of several amperes, the maximum charge quantity of 2 μC, and the duration of several microseconds. The relationship between the charge quantity and the current peak or the duration in each discharge was examined. The discharge between the cloud and the electrode placed at the outside of the cloud has relatively longer channels and multi-peak current with the longer duration, while that at the inside of the cloud has the lower charge quantity with single peak.

Shower maximum detector for SDC calorimetry

International Nuclear Information System (INIS)

Ernwein, J.

1994-01-01

A prototype for the SDC end-cap (EM) calorimeter complete with a pre-shower and a shower maximum detector was tested in beams of electrons and Π's at CERN by an SDC subsystem group. The prototype was manufactured from scintillator tiles and strips read out with 1 mm diameter wave-length shifting fibers. The design and construction of the shower maximum detector is described, and results of laboratory tests on light yield and performance of the scintillator-fiber system are given. Preliminary results on energy and position measurements with the shower max detector in the test beam are shown. (authors). 4 refs., 5 figs

Maximum Power Point Tracking in Variable Speed Wind Turbine Based on Permanent Magnet Synchronous Generator Using Maximum Torque Sliding Mode Control Strategy

Institute of Scientific and Technical Information of China (English)

Esmaeil Ghaderi; Hossein Tohidi; Behnam Khosrozadeh

2017-01-01

The present study was carried out in order to track the maximum power point in a variable speed turbine by minimizing electromechanical torque changes using a sliding mode control strategy.In this strategy,fhst,the rotor speed is set at an optimal point for different wind speeds.As a result of which,the tip speed ratio reaches an optimal point,mechanical power coefficient is maximized,and wind turbine produces its maximum power and mechanical torque.Then,the maximum mechanical torque is tracked using electromechanical torque.In this technique,tracking error integral of maximum mechanical torque,the error,and the derivative of error are used as state variables.During changes in wind speed,sliding mode control is designed to absorb the maximum energy from the wind and minimize the response time of maximum power point tracking (MPPT).In this method,the actual control input signal is formed from a second order integral operation of the original sliding mode control input signal.The result of the second order integral in this model includes control signal integrity,full chattering attenuation,and prevention from large fluctuations in the power generator output.The simulation results,calculated by using MATLAB/m-file software,have shown the effectiveness of the proposed control strategy for wind energy systems based on the permanent magnet synchronous generator (PMSG).

Age-Related Differences of Maximum Phonation Time in Patients after Cardiac Surgery

Directory of Open Access Journals (Sweden)

Kazuhiro P. Izawa

2017-12-01

Full Text Available Background and aims: Maximum phonation time (MPT, which is related to respiratory function, is widely used to evaluate maximum vocal capabilities, because its use is non-invasive, quick, and inexpensive. We aimed to examine differences in MPT by age, following recovery phase II cardiac rehabilitation (CR. Methods: This longitudinal observational study assessed 50 consecutive cardiac patients who were divided into the middle-aged group (<65 years, n = 29 and older-aged group (≥65 years, n = 21. MPTs were measured at 1 and 3 months after cardiac surgery, and were compared. Results: The duration of MPT increased more significantly from month 1 to month 3 in the middle-aged group (19.2 ± 7.8 to 27.1 ± 11.6 s, p < 0.001 than in the older-aged group (12.6 ± 3.5 to 17.9 ± 6.0 s, p < 0.001. However, no statistically significant difference occurred in the % change of MPT from 1 month to 3 months after cardiac surgery between the middle-aged group and older-aged group, respectively (41.1% vs. 42.1%. In addition, there were no significant interactions of MPT in the two groups for 1 versus 3 months (F = 1.65, p = 0.20. Conclusion: Following phase II, CR improved MPT for all cardiac surgery patients.

Age-Related Differences of Maximum Phonation Time in Patients after Cardiac Surgery.

Science.gov (United States)

Izawa, Kazuhiro P; Kasahara, Yusuke; Hiraki, Koji; Hirano, Yasuyuki; Watanabe, Satoshi

2017-12-21

Background and aims: Maximum phonation time (MPT), which is related to respiratory function, is widely used to evaluate maximum vocal capabilities, because its use is non-invasive, quick, and inexpensive. We aimed to examine differences in MPT by age, following recovery phase II cardiac rehabilitation (CR). Methods: This longitudinal observational study assessed 50 consecutive cardiac patients who were divided into the middle-aged group (<65 years, n = 29) and older-aged group (≥65 years, n = 21). MPTs were measured at 1 and 3 months after cardiac surgery, and were compared. Results: The duration of MPT increased more significantly from month 1 to month 3 in the middle-aged group (19.2 ± 7.8 to 27.1 ± 11.6 s, p < 0.001) than in the older-aged group (12.6 ± 3.5 to 17.9 ± 6.0 s, p < 0.001). However, no statistically significant difference occurred in the % change of MPT from 1 month to 3 months after cardiac surgery between the middle-aged group and older-aged group, respectively (41.1% vs. 42.1%). In addition, there were no significant interactions of MPT in the two groups for 1 versus 3 months (F = 1.65, p = 0.20). Conclusion: Following phase II, CR improved MPT for all cardiac surgery patients.

32 CFR 842.35 - Depreciation and maximum allowances.

Science.gov (United States)

2010-07-01

... 32 National Defense 6 2010-07-01 2010-07-01 false Depreciation and maximum allowances. 842.35... LITIGATION ADMINISTRATIVE CLAIMS Personnel Claims (31 U.S.C. 3701, 3721) § 842.35 Depreciation and maximum allowances. The military services have jointly established the “Allowance List-Depreciation Guide” to...

Identification and characterization of naturally occurring inhibitors against UDP-glucuronosyltransferase 1A1 in Fructus Psoraleae (Bu-gu-zhi)

International Nuclear Information System (INIS)

Wang, Xin-Xin; Lv, Xia; Li, Shi-Yang; Hou, Jie; Ning, Jing; Wang, Jia-Yue; Cao, Yun-Feng; Ge, Guang-Bo; Guo, Bin; Yang, Ling

2015-01-01

As an edible traditional Chinese herb, Fructus psoraleae (FP) has been widely used in Asia for the treatment of vitiligo, bone fracture and osteoporosis. Several cases on markedly elevated bilirubin and acute liver injury following administration of FP and its related proprietary medicine have been reported, but the mechanism in FP-associated toxicity has not been well investigated yet. This study aimed to investigate the inhibitory effects of FP extract and its major constituents against human UDP-glucuronosyltransferase 1A1 (UGT1A1), the key enzyme responsible for metabolic elimination of bilirubin. To this end, N-(3-carboxy propyl)-4-hydroxy-1,8-naphthalimide (NCHN), a newly developed specific fluorescent probe for UGT1A1, was used to evaluate the inhibitory effects of FP extract or its fractions in human liver microsomes (HLM), while LC-UV fingerprint and UGT1A1 inhibition profile were combined to identity and characterize the naturally occurring inhibitors of UGT1A1 in FP. Our results demonstrated that both the extract of FP and five major components of FP displayed evident inhibitory effects on UGT1A1 in HLM. Among these five identified naturally occurring inhibitors, bavachin and corylifol A were found to be strong inhibitors of UGT1A1 with the inhibition kinetic parameters (K i ) values lower than 1 μM, while neobavaisoflavone, isobavachalcone, and bavachinin displayed moderate inhibitory effects against UGT1A1 in HLM, with the K i values ranging from 1.61 to 9.86 μM. These findings suggested that FP contains natural compounds with potent inhibitory effects against human UGT1A1, which may be one of the important reasons for triggering FP-associated toxicity, including elevated bilirubin levels and liver injury. - Graphical abstract: LC-UV fingerprint and UGT1A1 inhibition profiles were combined to identity and characterize the natural inhibitors of UGT1A1 in F. psoraleae for the first time. Five major components in F. psoraleae were identified as strong

Identification and characterization of naturally occurring inhibitors against UDP-glucuronosyltransferase 1A1 in Fructus Psoraleae (Bu-gu-zhi)

Energy Technology Data Exchange (ETDEWEB)

Wang, Xin-Xin [Liaoning Medical University, Jinzhou, Liaoning (China); Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Lv, Xia; Li, Shi-Yang [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Hou, Jie [Dalian Medical University, Dalian 116044 (China); Ning, Jing [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Dalian Medical University, Dalian 116044 (China); Wang, Jia-Yue [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Cao, Yun-Feng [Liaoning Medical University, Jinzhou, Liaoning (China); Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Ge, Guang-Bo, E-mail: geguangbo@dicp.ac.cn [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Guo, Bin, E-mail: jyguobin@126.com [Liaoning Medical University, Jinzhou, Liaoning (China); Yang, Ling [Laboratory of Pharmaceutical Resource Discovery, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 (China); Jiangxi University of Traditional Chinese Medicine, Nanchang 330006 (China)

2015-11-15

As an edible traditional Chinese herb, Fructus psoraleae (FP) has been widely used in Asia for the treatment of vitiligo, bone fracture and osteoporosis. Several cases on markedly elevated bilirubin and acute liver injury following administration of FP and its related proprietary medicine have been reported, but the mechanism in FP-associated toxicity has not been well investigated yet. This study aimed to investigate the inhibitory effects of FP extract and its major constituents against human UDP-glucuronosyltransferase 1A1 (UGT1A1), the key enzyme responsible for metabolic elimination of bilirubin. To this end, N-(3-carboxy propyl)-4-hydroxy-1,8-naphthalimide (NCHN), a newly developed specific fluorescent probe for UGT1A1, was used to evaluate the inhibitory effects of FP extract or its fractions in human liver microsomes (HLM), while LC-UV fingerprint and UGT1A1 inhibition profile were combined to identity and characterize the naturally occurring inhibitors of UGT1A1 in FP. Our results demonstrated that both the extract of FP and five major components of FP displayed evident inhibitory effects on UGT1A1 in HLM. Among these five identified naturally occurring inhibitors, bavachin and corylifol A were found to be strong inhibitors of UGT1A1 with the inhibition kinetic parameters (K{sub i}) values lower than 1 μM, while neobavaisoflavone, isobavachalcone, and bavachinin displayed moderate inhibitory effects against UGT1A1 in HLM, with the K{sub i} values ranging from 1.61 to 9.86 μM. These findings suggested that FP contains natural compounds with potent inhibitory effects against human UGT1A1, which may be one of the important reasons for triggering FP-associated toxicity, including elevated bilirubin levels and liver injury. - Graphical abstract: LC-UV fingerprint and UGT1A1 inhibition profiles were combined to identity and characterize the natural inhibitors of UGT1A1 in F. psoraleae for the first time. Five major components in F. psoraleae were identified as

Overview of Maximum Power Point Tracking Techniques for Photovoltaic Energy Production Systems

DEFF Research Database (Denmark)

Koutroulis, Eftichios; Blaabjerg, Frede

2017-01-01

production of PV sources, despite the stochastically varying solar irradiation and ambient temperature conditions. Thereby, the overall efficiency of the PV energy production system is increased. Numerous techniques have been presented during the last decades for implementing the MPPT process in a PV system......A substantial growth of the installed photovoltaic (PV) systems capacity has occurred around the world during the last decade, thus enhancing the availability of electric energy in an environmentally friendly way. The maximum power point tracking (MPPT) technique enables to maximize the energy....... This chapter provides an overview of the operating principles of these techniques, which are suited for either uniform or nonuniform solar irradiation conditions. The operational characteristics and implementation requirements of these MPPT methods are also analyzed in order to demonstrate their performance...

Eliminating Inhibition of Return by Changing Salient Nonspatial Attributes in a Complex Environment

Science.gov (United States)

Hu, Frank K.; Samuel, Arthur G.; Chan, Agnes S.

2011-01-01

Inhibition of return (IOR) occurs when a target is preceded by an irrelevant stimulus (cue) at the same location: Target detection is slowed, relative to uncued locations. In the present study, we used relatively complex displays to examine the effect of repetition of nonspatial attributes. For both color and shape, attribute repetition produced a…

Corrosion inhibition of magnesium heated in wet air, by surface fluoridation

International Nuclear Information System (INIS)

Caillat, R.; Darras, R.; Leclercq, D.

1960-01-01

The maximum temperature (350 deg. C) of magnesium corrosion resistance in wet air may be raised to 490-500 deg. C by the formation of a superficial fluoride film. This can be obtained by two different ways: either by addition of hydrofluoric acid to the corroding medium in a very small proportion such as 0,003 mg/litre; at atmospheric pressure, or by dipping the magnesium in a dilute aqueous solution of nitric and hydrofluoric acids at room temperature before exposing it to the corroding atmosphere. In both cases the corrosion inhibition is effective over a very long time, even several thousand hours. (author) [fr

Comparison of oxime reactivation and aging of nerve agent-inhibited monkey and human acetylcholinesterases.

Science.gov (United States)

Luo, Chunyuan; Tong, Min; Maxwell, Donald M; Saxena, Ashima

2008-09-25

Non-human primates are valuable animal models that are used for the evaluation of nerve agent toxicity as well as antidotes and results from animal experiments are extrapolated to humans. It has been demonstrated that the efficacy of an oxime primarily depends on its ability to reactivate nerve agent-inhibited acetylcholinesterase (AChE). If the in vitro oxime reactivation of nerve agent-inhibited animal AChE is similar to that of human AChE, it is likely that the results of an in vivo animal study will reliably extrapolate to humans. Therefore, the goal of this study was to compare the aging and reactivation of human and different monkey (Rhesus, Cynomolgus, and African Green) AChEs inhibited by GF, GD, and VR. The oximes examined include the traditional oxime 2-PAM, two H-oximes HI-6 and HLo-7, and the new candidate oxime MMB4. Results indicate that oxime reactivation of all three monkey AChEs was very similar to human AChE. The maximum difference in the second-order reactivation rate constant between human and three monkey AChEs or between AChEs from different monkey species was 5-fold. Aging rate constants of GF-, GD-, and VR-inhibited monkey AChEs were very similar to human AChE except for GF-inhibited monkey AChEs, which aged 2-3 times faster than the human enzyme. The results of this study suggest that all three monkey species are suitable animal models for nerve agent antidote evaluation since monkey AChEs possess similar biochemical/pharmacological properties to human AChE.

Functional brain correlates of motor response inhibition in children with developmental coordination disorder and attention deficit/hyperactivity disorder.

Science.gov (United States)

Thornton, Siobhan; Bray, Signe; Langevin, Lisa Marie; Dewey, Deborah

2018-06-01

Motor impairment is associated with developmental coordination disorder (DCD), and to a lesser extent with attention-deficit/hyperactivity disorder (ADHD). Previous functional imaging studies investigated children with DCD or ADHD only; however, these two disorders co-occur in up to 50% of cases, suggesting that similar neural correlates are associated with these disorders. This study compared functional brain activation in children and adolescents (age range 8-17, M = 11.73, SD = 2.88) with DCD (n = 9), ADHD (n = 20), co-occurring DCD and ADHD (n = 18) and typically developing (TD) controls (n = 20). When compared to TD controls, children with co-occurring DCD/ADHD showed decreased activation during response inhibition in primary motor and sensory cortices. These findings suggest that children with co-occurring DCD and ADHD display significant functional changes in brain activation that could interfere with inhibition of erroneous motor responses. In contrast to previous studies, significant alterations in brain activation relative to TD controls, were not found in children with isolated DCD or ADHD. These findings highlight the importance of considering co-occurring disorders when investigating brain function in children with neurodevelopmental disorders. Copyright © 2018 Elsevier B.V. All rights reserved.

A mesic maximum in biological water use demarcates biome sensitivity to aridity shifts.

Science.gov (United States)

Good, Stephen P; Moore, Georgianne W; Miralles, Diego G

2017-12-01

Biome function is largely governed by how efficiently available resources can be used and yet for water, the ratio of direct biological resource use (transpiration, E T ) to total supply (annual precipitation, P) at ecosystem scales remains poorly characterized. Here, we synthesize field, remote sensing and ecohydrological modelling estimates to show that the biological water use fraction (E T /P) reaches a maximum under mesic conditions; that is, when evaporative demand (potential evapotranspiration, E P ) slightly exceeds supplied precipitation. We estimate that this mesic maximum in E T /P occurs at an aridity index (defined as E P /P) between 1.3 and 1.9. The observed global average aridity of 1.8 falls within this range, suggesting that the biosphere is, on average, configured to transpire the largest possible fraction of global precipitation for the current climate. A unimodal E T /P distribution indicates that both dry regions subjected to increasing aridity and humid regions subjected to decreasing aridity will suffer declines in the fraction of precipitation that plants transpire for growth and metabolism. Given the uncertainties in the prediction of future biogeography, this framework provides a clear and concise determination of ecosystems' sensitivity to climatic shifts, as well as expected patterns in the amount of precipitation that ecosystems can effectively use.

Inhibition of HIV-1 infection by aqueous extracts of Prunella vulgaris L.

Directory of Open Access Journals (Sweden)

McCoy Joe-Ann

2011-04-01

Full Text Available Abstract Background The mint family (Lamiaceae produces a wide variety of constituents with medicinal properties. Several family members have been reported to have antiviral activity, including lemon balm (Melissa officinalis L., sage (Salvia spp., peppermint (Mentha × piperita L., hyssop (Hyssopus officinalis L., basil (Ocimum spp. and self-heal (Prunella vulgaris L.. To further characterize the anti-lentiviral activities of Prunella vulgaris, water and ethanol extracts were tested for their ability to inhibit HIV-1 infection. Results Aqueous extracts contained more anti-viral activity than did ethanol extracts, displaying potent antiviral activity against HIV-1 at sub μg/mL concentrations with little to no cellular cytotoxicity at concentrations more than 100-fold higher. Time-of-addition studies demonstrated that aqueous extracts were effective when added during the first five hours following initiation of infection, suggesting that the botanical constituents were targeting entry events. Further analysis revealed that extracts inhibited both virus/cell interactions and post-binding events. While only 40% inhibition was maximally achieved in our virus/cell interaction studies, extract effectively blocked post-binding events at concentrations similar to those that blocked infection, suggesting that it was targeting of these latter steps that was most important for mediating inhibition of virus infectivity. Conclusions We demonstrate that aqueous P. vulgaris extracts inhibited HIV-1 infectivity. Our studies suggest that inhibition occurs primarily by interference of early, post-virion binding events. The ability of aqueous extracts to inhibit early events within the HIV life cycle suggests that these extracts, or purified constituents responsible for the antiviral activity, are promising microbicides and/or antivirals against HIV-1.

A Mechanism of Unidirectional Transformation, Leading to Antibiotic Resistance, Occurs within Nasopharyngeal Pneumococcal Biofilm Consortia.

Science.gov (United States)

Lattar, Santiago M; Wu, Xueqing; Brophy, Jennifer; Sakai, Fuminori; Klugman, Keith P; Vidal, Jorge E

2018-05-15

Streptococcus pneumoniae acquires genes for resistance to antibiotics such as streptomycin (Str) or trimethoprim (Tmp) by recombination via transformation of DNA released by other pneumococci and closely related species. Using naturally transformable pneumococci, including strain D39 serotype 2 (S2) and TIGR4 (S4), we studied whether pneumococcal nasopharyngeal transformation was symmetrical, asymmetrical, or unidirectional. Incubation of S2 Tet and S4 Str in a bioreactor simulating the human nasopharynx led to the generation of Spn Tet/Str recombinants. Double-resistant pneumococci emerged soon after 4 h postinoculation at a recombination frequency (rF) of 2.5 × 10 -4 while peaking after 8 h at a rF of 1.1 × 10 -3 Acquisition of antibiotic resistance genes by transformation was confirmed by treatment with DNase I. A high-throughput serotyping method demonstrated that all double-resistant pneumococci belonged to one serotype lineage (S2 Tet/Str ) and therefore that unidirectional transformation had occurred. Neither heterolysis nor availability of DNA for transformation was a factor for unidirectional transformation given that the density of each strain and extracellular DNA (eDNA) released from both strains were similar. Unidirectional transformation occurred regardless of the antibiotic-resistant gene carried by donors or acquired by recipients and regardless of whether competence-stimulating peptide-receptor cross talk was allowed. Moreover, unidirectional transformation occurred when two donor strains (e.g., S4 Str and S19F Tmp ) were incubated together, leading to S19F Str/Tmp but at a rF 3 orders of magnitude lower (4.9 × 10 -6 ). We finally demonstrated that the mechanism leading to unidirectional transformation was due to inhibition of transformation of the donor by the recipient. IMPORTANCE Pneumococcal transformation in the human nasopharynx may lead to the acquisition of antibiotic resistance genes or genes encoding new capsular variants

Anaerobic co-digestion of waste activated sludge and greasy sludge from flotation process: batch versus CSTR experiments to investigate optimal design.

Science.gov (United States)

Girault, R; Bridoux, G; Nauleau, F; Poullain, C; Buffet, J; Peu, P; Sadowski, A G; Béline, F

2012-02-01

In this study, the maximum ratio of greasy sludge to incorporate with waste activated sludge was investigated in batch and CSTR experiments. In batch experiments, inhibition occurred with a greasy sludge ratio of more than 20-30% of the feed COD. In CSTR experiments, the optimal greasy sludge ratio was 60% of the feed COD and inhibition occurred above a ratio of 80%. Hence, batch experiments can predict the CSTR yield when the degradation phenomenon are additive but cannot be used to determine the maximum ratio to be used in a CSTR configuration. Additionally, when the ratio of greasy sludge increased from 0% to 60% of the feed COD, CSTR methane production increased by more than 60%. When the greasy sludge ratio increased from 60% to 90% of the feed COD, the reactor yield decreased by 75%. Copyright © 2011 Elsevier Ltd. All rights reserved.

Enhancing arsenic removal from groundwater at household level with naturally occurring iron

Directory of Open Access Journals (Sweden)

Anitha Kumari Sharma

2016-06-01

Full Text Available A supply of drinking water low in Arsenic (As prevents arsenic poisoning. The presence of high concentrations of iron (Fe in groundwater under the alluvial plains of the large rivers in Southeast Asia is a prerequisite for the simple removal of As. This study investigated the mechanisms and possibilities for enhancing As removal with naturally occurring Fe in a reliable, low cost and sustainable way. The results of the study show that As removal with Fe is greatly enhanced by the addition of an oxidizing agent (preferably KMnO4 immediately after the pumping of groundwater. Further enhancement of As removal in the presence of Fe can be achieved by adding a small volume of a concentrated basic solution of MnO4- and AlO2-, which has a combined oxidation, coagulation and buffering capacity. Best results were obtained when this solution was mixed with the groundwater immediately after its pumping until a pale pink color appeared. Maximum required reaction time was 10 minutes and subsequent filtration of the water was able to reduce the As concentration to near zero. Concentrations of MnO4- and AlO2- can be varied in the solution to achieve sufficient As removal to suit different Fe/As ratios and the presence of interfering co-occurring anions.

The neural markers of an imminent failure of response inhibition.

Science.gov (United States)

Bengson, Jesse J; Mangun, George R; Mazaheri, Ali

2012-01-16

In his novel Ulysses, James Joyce wrote that mistakes are the "…portals of discovery". The present study investigated the pre-stimulus oscillatory EEG signatures of selective attention and motor preparation that predicted failures of overt response inhibition. We employed a trial-by-trial spatial cueing task using a go/no-go response paradigm with bilateral target stimuli. Subjects were required to covertly attend to the spatial location cued on each trial and respond to most of the number targets (go trials) at that location while withholding responses for one designated number (no-go trials). We analyzed the post-cue/pre-target spectral patterns comparing no-go trials in which a response occurred in error (False Alarms, FA) with trials in which participants correctly withheld a response (Correct Rejections, CR). We found that cue-induced occipital alpha (8-12 Hz) lateralization and inter-frequency anti-correlations between the motor beta (18-24 Hz) and pre-frontal theta (3-5 Hz) bands each independently predicted subsequent failures of response inhibition. Based on these findings, we infer that independent perceptual and motor mechanisms operate in parallel to contribute to failures of response inhibition. Copyright © 2011 Elsevier Inc. All rights reserved.

Inhibition of uropathogenic biofilm growth on silicone rubber in human urine by lactobacilli - a teleologic approach

NARCIS (Netherlands)

Velraeds, MMC; van de Belt-Gritter, B; Busscher, HJ; Reid, G; van der Mei, HC

2000-01-01

The ability of three Lactobacillus strains to inhibit the adhesion and growth of naturally occurring uropathogens on silicone rubber was investigated in human urine. The importance of biosurfactant production by Lactobacillus in discouraging uropathogen growth was determined in relation to the

40 CFR 141.63 - Maximum contaminant levels (MCLs) for microbiological contaminants.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels (MCLs) for microbiological contaminants. 141.63 Section 141.63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.63 Maximum...

Effect of racemic ibuprofen dose on the magnitude and duration of platelet cyclo-oxygenase inhibition: relationship between inhibition of thromboxane production and the plasma unbound concentration of S(+)-ibuprofen.

Science.gov (United States)

Evans, A M; Nation, R L; Sansom, L N; Bochner, F; Somogyi, A A

1991-02-01

1. Four healthy male subjects received racemic ibuprofen (200, 400, 800 and 1200 mg), orally, on four occasions, 2 weeks apart, according to a four-way Latin-square design, in order to investigate the influence of increasing dose of ibuprofen on the magnitude and duration of its antiplatelet effect as well as on the relationship between such effect and drug concentration. 2. The antiplatelet effect of ibuprofen was assessed by measuring the inhibition of platelet thromboxane B2 (TXB2) generation during the controlled clotting of whole blood. The plasma unbound concentration of S(+)-ibuprofen, the enantiomer shown in an in vitro study to be responsible for the inhibitory effect of platelet TXB2 generation, was measured using an enantioselective method. 3. The maximum percentage inhibition of TXB2 generation increased significantly with dose from a mean +/- s.d. of 93.4 +/- 1.2% after the 200 mg dose to 98.8 +/- 0.3% after the 1200 mg dose, and there was an increase with dose in the duration of inhibition of TXB2 generation. The effect of ibuprofen on platelet TXB2 generation was transient and mirrored the time-course of unbound S(+)-ibuprofen in plasma; on all but one of the 16 occasions, serum TXB2 concentrations returned to at least within 10% of the pretreatment concentrations within 24 h of ibuprofen administration. 4. For each subject, the relationship between the percentage inhibition of TXB2 generation and the unbound concentration of S(+)-ibuprofen in plasma was modelled according to a sigmoidal Emax equation. The mean plasma unbound concentration of S(+)-ibuprofen required to inhibit platelet TXB2 generation by 50% (EC50) was 9.8 +/- 1.0 micrograms l-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Particle Swarm Optimization Based of the Maximum Photovoltaic ...

African Journals Online (AJOL)

Photovoltaic electricity is seen as an important source of renewable energy. The photovoltaic array is an unstable source of power since the peak power point depends on the temperature and the irradiation level. A maximum peak power point tracking is then necessary for maximum efficiency. In this work, a Particle Swarm ...

40 CFR 1045.140 - What is my engine's maximum engine power?

Science.gov (United States)

2010-07-01

...) Maximum engine power for an engine family is generally the weighted average value of maximum engine power... engine family's maximum engine power apply in the following circumstances: (1) For outboard or personal... value for maximum engine power from all the different configurations within the engine family to...

42 CFR 409.62 - Lifetime maximum on inpatient psychiatric care.

Science.gov (United States)

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Lifetime maximum on inpatient psychiatric care. 409....62 Lifetime maximum on inpatient psychiatric care. There is a lifetime maximum of 190 days on inpatient psychiatric hospital services available to any beneficiary. Therefore, once an individual receives...

Maximum-entropy description of animal movement.

Science.gov (United States)

Fleming, Chris H; Subaşı, Yiğit; Calabrese, Justin M

2015-03-01

We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic.

Apigenin Restricts FMDV Infection and Inhibits Viral IRES Driven Translational Activity

Directory of Open Access Journals (Sweden)

Suhong Qian

2015-03-01

Full Text Available Foot-and-mouth disease (FMD is a highly contagious disease of domestic and wild ruminants that is caused by FMD virus (FMDV. FMD outbreaks have occurred in livestock-containing regions worldwide. Apigenin, which is a flavonoid naturally existing in plant, possesses various pharmacological effects, including anti-inflammatory, anticancer, antioxidant and antiviral activities. Results show that apigenin can inhibit FMDV-mediated cytopathogenic effect and FMDV replication in vitro. Further studies demonstrate the following: (i apigenin inhibits FMDV infection at the viral post-entry stage; (ii apigenin does not exhibit direct extracellular virucidal activity; and (iii apigenin interferes with the translational activity of FMDV driven by internal ribosome entry site. Studies on applying apigein in vivo are required for drug development and further identification of potential drug targets against FDMV infection.

Apigenin restricts FMDV infection and inhibits viral IRES driven translational activity.

Science.gov (United States)

Qian, Suhong; Fan, Wenchun; Qian, Ping; Zhang, Dong; Wei, Yurong; Chen, Huanchun; Li, Xiangmin

2015-03-31

Foot-and-mouth disease (FMD) is a highly contagious disease of domestic and wild ruminants that is caused by FMD virus (FMDV). FMD outbreaks have occurred in livestock-containing regions worldwide. Apigenin, which is a flavonoid naturally existing in plant, possesses various pharmacological effects, including anti-inflammatory, anticancer, antioxidant and antiviral activities. Results show that apigenin can inhibit FMDV-mediated cytopathogenic effect and FMDV replication in vitro. Further studies demonstrate the following: (i) apigenin inhibits FMDV infection at the viral post-entry stage; (ii) apigenin does not exhibit direct extracellular virucidal activity; and (iii) apigenin interferes with the translational activity of FMDV driven by internal ribosome entry site. Studies on applying apigein in vivo are required for drug development and further identification of potential drug targets against FDMV infection.

On Maximum Entropy and Inference

Directory of Open Access Journals (Sweden)

Luigi Gresele

2017-11-01

Full Text Available Maximum entropy is a powerful concept that entails a sharp separation between relevant and irrelevant variables. It is typically invoked in inference, once an assumption is made on what the relevant variables are, in order to estimate a model from data, that affords predictions on all other (dependent variables. Conversely, maximum entropy can be invoked to retrieve the relevant variables (sufficient statistics directly from the data, once a model is identified by Bayesian model selection. We explore this approach in the case of spin models with interactions of arbitrary order, and we discuss how relevant interactions can be inferred. In this perspective, the dimensionality of the inference problem is not set by the number of parameters in the model, but by the frequency distribution of the data. We illustrate the method showing its ability to recover the correct model in a few prototype cases and discuss its application on a real dataset.

Lead inhibition of DNA-binding mechanism of Cys(2)His(2) zinc finger proteins.

Science.gov (United States)

Hanas, J S; Rodgers, J S; Bantle, J A; Cheng, Y G

1999-11-01

The association of lead with chromatin in cells suggests that deleterious metal effects may in part be mediated through alterations in gene function. To elucidate if and how lead may alter DNA binding of cysteine-rich zinc finger proteins, lead ions were analyzed for their ability to alter the DNA binding mechanism of the Cys(2)His(2) zinc finger protein transcription factor IIIA (TFIIIA). As assayed by DNase I protection, the interaction of TFIIIA with the 50-bp internal control region of the 5S ribosomal gene was partially inhibited by 5 microM lead ions and completely inhibited by 10 to 20 microM lead ions. Preincubation of free TFIIIA with lead resulted in DNA-binding inhibition, whereas preincubation of a TFIIIA/5S RNA complex with lead did not result in DNA-binding inhibition. Because 5S RNA binds TFIIIA zinc fingers, this result is consistent with an inhibition mechanism via lead binding to zinc fingers. The complete loss of DNase I protection on the 5S gene indicates the mechanism of inhibition minimally involves the N-terminal fingers of TFIIIA. Inhibition was not readily reversible and occurred in the presence of an excess of beta-mercaptoethanol. Inhibition kinetics were fast, progressing to completion in approximately 5 min. Millimolar concentrations of sulfhydryl-specific arsenic ions were not inhibitory for TFIIIA binding. Micromolar concentrations of lead inhibited DNA binding by Sp1, another Cys(2)His(2) finger protein, but not by the nonfinger protein AP2. Inhibition of Cys(2)His(2) zinc finger transcription factors by lead ions at concentrations near those known to have deleterious physiological effects points to new molecular mechanisms for lead toxicity in promoting disease.

Mycotoxins in grapes and wine in Europe: Occurence, factors affecting the occurence and related toxicological effects

NARCIS (Netherlands)

Stratakou, I.; Fels-Klerx, van der H.J.

2010-01-01

In 2006, the European Commission has established maximum levels for ochratoxin A in wine and grape products, using occurrence data up to 2001 and toxicity data up to 2006. This paper presents an up-to-date overview of the occurrence of mycotoxins in grapes and wine produced in Europe in the period

Fractal Dimension and Maximum Sunspot Number in Solar Cycle

Directory of Open Access Journals (Sweden)

R.-S. Kim

2006-09-01

Full Text Available The fractal dimension is a quantitative parameter describing the characteristics of irregular time series. In this study, we use this parameter to analyze the irregular aspects of solar activity and to predict the maximum sunspot number in the following solar cycle by examining time series of the sunspot number. For this, we considered the daily sunspot number since 1850 from SIDC (Solar Influences Data analysis Center and then estimated cycle variation of the fractal dimension by using Higuchi's method. We examined the relationship between this fractal dimension and the maximum monthly sunspot number in each solar cycle. As a result, we found that there is a strong inverse relationship between the fractal dimension and the maximum monthly sunspot number. By using this relation we predicted the maximum sunspot number in the solar cycle from the fractal dimension of the sunspot numbers during the solar activity increasing phase. The successful prediction is proven by a good correlation (r=0.89 between the observed and predicted maximum sunspot numbers in the solar cycles.

Quantitative analysis of the modes of growth inhibition by weak organic acids in Saccharomyces cerevisiae

NARCIS (Netherlands)

Ullah, A.; Orij, R.; Brul, S.; Smits, G.J.

2012-01-01

Weak organic acids are naturally occurring compounds that are commercially used as preservatives in the food and beverage industries. They extend the shelf life of food products by inhibiting microbial growth. There are a number of theories that explain the antifungal properties of these weak acids,

Automatic maximum entropy spectral reconstruction in NMR

International Nuclear Information System (INIS)

Mobli, Mehdi; Maciejewski, Mark W.; Gryk, Michael R.; Hoch, Jeffrey C.

2007-01-01

Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system

Stationary neutrino radiation transport by maximum entropy closure

International Nuclear Information System (INIS)

Bludman, S.A.

1994-11-01

The authors obtain the angular distributions that maximize the entropy functional for Maxwell-Boltzmann (classical), Bose-Einstein, and Fermi-Dirac radiation. In the low and high occupancy limits, the maximum entropy closure is bounded by previously known variable Eddington factors that depend only on the flux. For intermediate occupancy, the maximum entropy closure depends on both the occupation density and the flux. The Fermi-Dirac maximum entropy variable Eddington factor shows a scale invariance, which leads to a simple, exact analytic closure for fermions. This two-dimensional variable Eddington factor gives results that agree well with exact (Monte Carlo) neutrino transport calculations out of a collapse residue during early phases of hydrostatic neutron star formation

Prestimulus Inhibition of Saccades in Adults With and Without Attention-Deficit/Hyperactivity Disorder as an Index of Temporal Expectations.

Science.gov (United States)

Dankner, Yarden; Shalev, Lilach; Carrasco, Marisa; Yuval-Greenberg, Shlomit

2017-07-01

Knowing when to expect important events to occur is critical for preparing context-appropriate behavior. However, anticipation is inherently complicated to assess because conventional measurements of behavior, such as accuracy and reaction time, are available only after the predicted event has occurred. Anticipatory processes, which occur prior to target onset, are typically measured only retrospectively by these methods. In this study, we utilized a novel approach for assessing temporal expectations through the dynamics of prestimulus saccades. Results showed that saccades of neurotypical participants were inhibited prior to the onset of stimuli that appeared at predictable compared with less predictable times. No such inhibition was found in most participants with attention-deficit/hyperactivity disorder (ADHD), and particularly not in those who experienced difficulties in sustaining attention over time. These findings suggest that individuals with ADHD, especially those with sustained-attention deficits, have diminished ability to benefit from temporal predictability, and this could account for some of their context-inappropriate behaviors.

INHIBITION IN SPEAKING PERFORMANCE

OpenAIRE

Humaera, Isna

2015-01-01

The most common problem encountered by the learner in the languageacquisition process is learner inhibition. Inhibition refers to a temperamentaltendency to display wariness, fearfulness, or restrain in response tounfamiliar people, objects, and situations. There are some factors that causeinhibition, such as lack of motivation, shyness, self-confidence, self-esteem,and language ego. There are also levels of inhibition, it refers to kinds ofinhibition and caused of inhibition itself. Teacher ...

Maximum power per VA control of vector controlled interior ...

Indian Academy of Sciences (India)

Thakur Sumeet Singh

2018-04-11

Apr 11, 2018 ... Department of Electrical Engineering, Indian Institute of Technology Delhi, New ... The MPVA operation allows maximum-utilization of the drive-system. ... Permanent magnet motor; unity power factor; maximum VA utilization; ...

Application of maximum entropy to neutron tunneling spectroscopy

International Nuclear Information System (INIS)

Mukhopadhyay, R.; Silver, R.N.

1990-01-01

We demonstrate the maximum entropy method for the deconvolution of high resolution tunneling data acquired with a quasielastic spectrometer. Given a precise characterization of the instrument resolution function, a maximum entropy analysis of lutidine data obtained with the IRIS spectrometer at ISIS results in an effective factor of three improvement in resolution. 7 refs., 4 figs

Maximum Expected Wall Heat Flux and Maximum Pressure After Sudden Loss of Vacuum Insulation on the Stratospheric Observatory for Infrared Astronomy (SOFIA) Liquid Helium (LHe) Dewars

Science.gov (United States)

Ungar, Eugene K.

2014-01-01

The aircraft-based Stratospheric Observatory for Infrared Astronomy (SOFIA) is a platform for multiple infrared observation experiments. The experiments carry sensors cooled to liquid helium (LHe) temperatures. A question arose regarding the heat input and peak pressure that would result from a sudden loss of the dewar vacuum insulation. Owing to concerns about the adequacy of dewar pressure relief in the event of a sudden loss of the dewar vacuum insulation, the SOFIA Program engaged the NASA Engineering and Safety Center (NESC). This report summarizes and assesses the experiments that have been performed to measure the heat flux into LHe dewars following a sudden vacuum insulation failure, describes the physical limits of heat input to the dewar, and provides an NESC recommendation for the wall heat flux that should be used to assess the sudden loss of vacuum insulation case. This report also assesses the methodology used by the SOFIA Program to predict the maximum pressure that would occur following a loss of vacuum event.

RTEL1 inhibits trinucleotide repeat expansions and fragility.

Science.gov (United States)

Frizzell, Aisling; Nguyen, Jennifer H G; Petalcorin, Mark I R; Turner, Katherine D; Boulton, Simon J; Freudenreich, Catherine H; Lahue, Robert S

2014-03-13

Human RTEL1 is an essential, multifunctional helicase that maintains telomeres, regulates homologous recombination, and helps prevent bone marrow failure. Here, we show that RTEL1 also blocks trinucleotide repeat expansions, the causal mutation for 17 neurological diseases. Increased expansion frequencies of (CTG⋅CAG) repeats occurred in human cells following knockdown of RTEL1, but not the alternative helicase Fbh1, and purified RTEL1 efficiently unwound triplet repeat hairpins in vitro. The expansion-blocking activity of RTEL1 also required Rad18 and HLTF, homologs of yeast Rad18 and Rad5. These findings are reminiscent of budding yeast Srs2, which inhibits expansions, unwinds hairpins, and prevents triplet-repeat-induced chromosome fragility. Accordingly, we found expansions and fragility were suppressed in yeast srs2 mutants expressing RTEL1, but not Fbh1. We propose that RTEL1 serves as a human analog of Srs2 to inhibit (CTG⋅CAG) repeat expansions and fragility, likely by unwinding problematic hairpins. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

The maximum economic depth of groundwater abstraction for irrigation

Science.gov (United States)

Bierkens, M. F.; Van Beek, L. P.; de Graaf, I. E. M.; Gleeson, T. P.

2017-12-01

Over recent decades, groundwater has become increasingly important for agriculture. Irrigation accounts for 40% of the global food production and its importance is expected to grow further in the near future. Already, about 70% of the globally abstracted water is used for irrigation, and nearly half of that is pumped groundwater. In many irrigated areas where groundwater is the primary source of irrigation water, groundwater abstraction is larger than recharge and we see massive groundwater head decline in these areas. An important question then is: to what maximum depth can groundwater be pumped for it to be still economically recoverable? The objective of this study is therefore to create a global map of the maximum depth of economically recoverable groundwater when used for irrigation. The maximum economic depth is the maximum depth at which revenues are still larger than pumping costs or the maximum depth at which initial investments become too large compared to yearly revenues. To this end we set up a simple economic model where costs of well drilling and the energy costs of pumping, which are a function of well depth and static head depth respectively, are compared with the revenues obtained for the irrigated crops. Parameters for the cost sub-model are obtained from several US-based studies and applied to other countries based on GDP/capita as an index of labour costs. The revenue sub-model is based on gross irrigation water demand calculated with a global hydrological and water resources model, areal coverage of crop types from MIRCA2000 and FAO-based statistics on crop yield and market price. We applied our method to irrigated areas in the world overlying productive aquifers. Estimated maximum economic depths range between 50 and 500 m. Most important factors explaining the maximum economic depth are the dominant crop type in the area and whether or not initial investments in well infrastructure are limiting. In subsequent research, our estimates of

What controls the maximum magnitude of injection-induced earthquakes?

Science.gov (United States)

Eaton, D. W. S.

2017-12-01

Three different approaches for estimation of maximum magnitude are considered here, along with their implications for managing risk. The first approach is based on a deterministic limit for seismic moment proposed by McGarr (1976), which was originally designed for application to mining-induced seismicity. This approach has since been reformulated for earthquakes induced by fluid injection (McGarr, 2014). In essence, this method assumes that the upper limit for seismic moment release is constrained by the pressure-induced stress change. A deterministic limit is given by the product of shear modulus and the net injected fluid volume. This method is based on the assumptions that the medium is fully saturated and in a state of incipient failure. An alternative geometrical approach was proposed by Shapiro et al. (2011), who postulated that the rupture area for an induced earthquake falls entirely within the stimulated volume. This assumption reduces the maximum-magnitude problem to one of estimating the largest potential slip surface area within a given stimulated volume. Finally, van der Elst et al. (2016) proposed that the maximum observed magnitude, statistically speaking, is the expected maximum value for a finite sample drawn from an unbounded Gutenberg-Richter distribution. These three models imply different approaches for risk management. The deterministic method proposed by McGarr (2014) implies that a ceiling on the maximum magnitude can be imposed by limiting the net injected volume, whereas the approach developed by Shapiro et al. (2011) implies that the time-dependent maximum magnitude is governed by the spatial size of the microseismic event cloud. Finally, the sample-size hypothesis of Van der Elst et al. (2016) implies that the best available estimate of the maximum magnitude is based upon observed seismicity rate. The latter two approaches suggest that real-time monitoring is essential for effective management of risk. A reliable estimate of maximum

Topics in Bayesian statistics and maximum entropy

International Nuclear Information System (INIS)

Mutihac, R.; Cicuttin, A.; Cerdeira, A.; Stanciulescu, C.

1998-12-01

Notions of Bayesian decision theory and maximum entropy methods are reviewed with particular emphasis on probabilistic inference and Bayesian modeling. The axiomatic approach is considered as the best justification of Bayesian analysis and maximum entropy principle applied in natural sciences. Particular emphasis is put on solving the inverse problem in digital image restoration and Bayesian modeling of neural networks. Further topics addressed briefly include language modeling, neutron scattering, multiuser detection and channel equalization in digital communications, genetic information, and Bayesian court decision-making. (author)

Identification of nevadensin as an important herb-based constituent inhibiting estragole bioactivation and physiology-based biokinetic modeling of its possible in vivo effect

International Nuclear Information System (INIS)

Alhusainy, W.; Paini, A.; Punt, A.; Louisse, J.; Spenkelink, A.; Vervoort, J.; Delatour, T.; Scholz, G.; Schilter, B.; Adams, T.; Bladeren, P.J. van; Rietjens, I.M.C.M.

2010-01-01

Estragole is a natural constituent of several herbs and spices including sweet basil. In rodent bioassays, estragole induces hepatomas, an effect ascribed to estragole bioactivation to 1'-sulfooxyestragole resulting in DNA adduct formation. The present paper identifies nevadensin as a basil constituent able to inhibit DNA adduct formation in rat hepatocytes exposed to the proximate carcinogen 1'-hydroxyestragole and nevadensin. This inhibition occurs at the level of sulfotransferase (SULT)-mediated bioactivation of 1'-hydroxyestragole. The Ki for SULT inhibition by nevadensin was 4 nM in male rat and human liver fractions. Furthermore, nevadensin up to 20 μM did not inhibit 1'-hydroxyestragole detoxification by glucuronidation and oxidation. The inhibition of SULT by nevadensin was incorporated into the recently developed physiologically based biokinetic (PBBK) rat and human models for estragole bioactivation and detoxification. The results predict that co-administration of estragole at a level inducing hepatic tumors in vivo (50 mg/kg bw) with nevadensin at a molar ratio of 0.06, representing the ratio of their occurrence in basil, results in almost 100% inhibition of the ultimate carcinogen 1'-sulfooxyestragole when assuming 100% uptake of nevadensin. Assuming 1% uptake, inhibition would still amount to more than 83%. Altogether these data point at a nevadensin-mediated inhibition of the formation of the ultimate carcinogenic metabolite of estragole, without reducing the capacity to detoxify 1'-hydroxyestragole via glucuronidation or oxidation. These data also point at a potential reduction of the cancer risk when estragole exposure occurs within a food matrix containing SULT inhibitors compared to what is observed upon exposure to pure estragole.

Inhibition of tobacco mosaic virus replication in lateral roots is dependent on an activated meristem-derived signal.

Science.gov (United States)

Valentine, T A; Roberts, I M; Oparka, K J

2002-05-01

Viral invasion of the root system of Nicotiana benthamiana was studied noninvasively with a tobacco mosaic virus (TMV) vector expressing the green-fluorescent protein (GFP). Lateral root primordia, which developed from the pericycle of primary roots, became heavily infected as they emerged from the root cortex. However, following emergence, a progressive wave of viral inhibition occurred that originated in the lateral-root meristem and progressed towards its base. Excision of source and sink tissues suggested that the inhibition of virus replication was brought about by the basipetal movement of a root meristem signal. When infected plants were inoculated with tobacco rattle virus (TRV) expressing the red-fluorescent protein, DsRed, TRV entered the lateral roots and suppressed the host response, leading to a reestablishment of TMV infection in lateral roots. By infecting GFP-expressing transgenic plants with TMV carrying the complementary GFP sequence it was possible to silence the host GFP, leading to the complete loss of fluorescence in lateral roots. The data suggest that viral inhibition in lateral roots occurs by a gene-silencing-like mechanism that is dependent on the activation of a lateral-root meristem.

ITE inhibits growth of human pulmonary artery endothelial cells.

Science.gov (United States)

Pang, Ling-Pin; Li, Yan; Zou, Qing-Yun; Zhou, Chi; Lei, Wei; Zheng, Jing; Huang, Shi-An

2017-10-01

Pulmonary arterial hypertension (PAH), a deadly disorder is associated with excessive growth of human pulmonary artery endothelial (HPAECs) and smooth muscle (HPASMCs) cells. Current therapies primarily aim at promoting vasodilation, which only ameliorates clinical symptoms without a cure. 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE) is an endogenous aryl hydrocarbon receptor (AhR) ligand, and mediates many cellular function including cell growth. However, the roles of ITE in human lung endothelial cells remain elusive. Herein, we tested a hypothesis that ITE inhibits growth of human pulmonary artery endothelial cells via AhR. Immunohistochemistry was performed to localize AhR expression in human lung tissues. The crystal violet method and MTT assay were used to determine ITE's effects on growth of HPAECs. The AhR activation in HPAECs was confirmed using Western blotting and RT-qPCR. The role of AhR in ITE-affected proliferation of HPAECs was assessed using siRNA knockdown method followed by the crystal violet method. Immunohistochemistry revealed that AhR was present in human lung tissues, primarily in endothelial and smooth muscle cells of pulmonary veins and arteries, as well as in bronchial and alveolar sac epithelia. We also found that ITE dose- and time-dependently inhibited proliferation of HPAECs with a maximum inhibition of 83% at 20 µM after 6 days of treatment. ITE rapidly decreased AhR protein levels, while it increased mRNA levels of cytochrome P450 (CYP), family 1, member A1 (CYP1A1) and B1 (CYP1B1), indicating activation of the AhR/CYP1A1 and AhR/CYP1B1 pathways in HPAECs. The AhR siRNA significantly suppressed AhR protein expression, whereas it did not significantly alter ITE-inhibited growth of HPAECs. ITE suppresses growth of HPAECs independent of AhR, suggesting that ITE may play an important role in preventing excessive growth of lung endothelial cells.

Relative timing of last glacial maximum and late-glacial events in the central tropical Andes

Science.gov (United States)

Bromley, Gordon R. M.; Schaefer, Joerg M.; Winckler, Gisela; Hall, Brenda L.; Todd, Claire E.; Rademaker, Kurt M.

2009-11-01

Whether or not tropical climate fluctuated in synchrony with global events during the Late Pleistocene is a key problem in climate research. However, the timing of past climate changes in the tropics remains controversial, with a number of recent studies reporting that tropical ice age climate is out of phase with global events. Here, we present geomorphic evidence and an in-situ cosmogenic 3He surface-exposure chronology from Nevado Coropuna, southern Peru, showing that glaciers underwent at least two significant advances during the Late Pleistocene prior to Holocene warming. Comparison of our glacial-geomorphic map at Nevado Coropuna to mid-latitude reconstructions yields a striking similarity between Last Glacial Maximum (LGM) and Late-Glacial sequences in tropical and temperate regions. Exposure ages constraining the maximum and end of the older advance at Nevado Coropuna range between 24.5 and 25.3 ka, and between 16.7 and 21.1 ka, respectively, depending on the cosmogenic production rate scaling model used. Similarly, the mean age of the younger event ranges from 10 to 13 ka. This implies that (1) the LGM and the onset of deglaciation in southern Peru occurred no earlier than at higher latitudes and (2) that a significant Late-Glacial event occurred, most likely prior to the Holocene, coherent with the glacial record from mid and high latitudes. The time elapsed between the end of the LGM and the Late-Glacial event at Nevado Coropuna is independent of scaling model and matches the period between the LGM termination and Late-Glacial reversal in classic mid-latitude records, suggesting that these events in both tropical and temperate regions were in phase.

Combining Experiments and Simulations Using the Maximum Entropy Principle

DEFF Research Database (Denmark)

Boomsma, Wouter; Ferkinghoff-Borg, Jesper; Lindorff-Larsen, Kresten

2014-01-01

are not in quantitative agreement with experimental data. The principle of maximum entropy is a general procedure for constructing probability distributions in the light of new data, making it a natural tool in cases when an initial model provides results that are at odds with experiments. The number of maximum entropy...... in the context of a simple example, after which we proceed with a real-world application in the field of molecular simulations, where the maximum entropy procedure has recently provided new insight. Given the limited accuracy of force fields, macromolecular simulations sometimes produce results....... Three very recent papers have explored this problem using the maximum entropy approach, providing both new theoretical and practical insights to the problem. We highlight each of these contributions in turn and conclude with a discussion on remaining challenges....

Boric acid inhibits embryonic histone deacetylases: A suggested mechanism to explain boric acid-related teratogenicity

International Nuclear Information System (INIS)

Di Renzo, Francesca; Cappelletti, Graziella; Broccia, Maria L.; Giavini, Erminio; Menegola, Elena

2007-01-01

Histone deacetylases (HDAC) control gene expression by changing histonic as well as non histonic protein conformation. HDAC inhibitors (HDACi) are considered to be among the most promising drugs for epigenetic treatment for cancer. Recently a strict relationship between histone hyperacetylation in specific tissues of mouse embryos exposed to two HDACi (valproic acid and trichostatin A) and specific axial skeleton malformations has been demonstrated. The aim of this study is to verify if boric acid (BA), that induces in rodents malformations similar to those valproic acid and trichostatin A-related, acts through similar mechanisms: HDAC inhibition and histone hyperacetylation. Pregnant mice were treated intraperitoneally with a teratogenic dose of BA (1000 mg/kg, day 8 of gestation). Western blot analysis and immunostaining were performed with anti hyperacetylated histone 4 (H4) antibody on embryos explanted 1, 3 or 4 h after treatment and revealed H4 hyperacetylation at the level of somites. HDAC enzyme assay was performed on embryonic nuclear extracts. A significant HDAC inhibition activity (compatible with a mixed type partial inhibition mechanism) was evident with BA. Kinetic analyses indicate that BA modifies substrate affinity by a factor α = 0.51 and maximum velocity by a factor β = 0.70. This work provides the first evidence for HDAC inhibition by BA and suggests such a molecular mechanism for the induction of BA-related malformations

Maximum entropy beam diagnostic tomography

International Nuclear Information System (INIS)

Mottershead, C.T.

1985-01-01

This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore

Long-lasting ovulation inhibition with a new injectable progestagen ORG-2154.

Science.gov (United States)

Coutinho, E M; De Souza, J C; Barbosa, I C; Dourado Silva, V

1982-06-01

A new long-acting injectable progestagen was tested in 15 women who volunteered for the study. The occurrence of ovulation was assumed by the elevation of progesterone levels above 2ng/ml following a pre-ovulatory estradiol peak. Following a 200mg injection, ovulation was inhibited in all 15 women for five to ten months. In four subjects the interval between the injection and the first progesterone peak was five months. For eight, the interval was six to eight months. In the other three women, ovulation occurred more than eight months following injection. Bleeding episodes, similar to menstruation, occurred in most patients. Bleeding intervals lasting longer than 45 days occurred in nine subjects but more prolonged amenorrhea lasting longer than 60 days was reported by only five subjects. Blood chemistry which included blood cell counts, cholesterol, glucose, alkaline phosphatase, transaminases, urea nitrogen and creatinine remained within normal limits throughout the treatment.

Gastrointestinal motor inhibition by exogenous human, salmon, and eel calcitonin in conscious dogs.

Science.gov (United States)

Nakamura, H; Asano, T; Haruta, K; Takeda, K

1995-01-01

Effects of synthetic eel (E-), salmon (S-), and human (H-) calcitonin (CT) on gastrointestinal motility were studied in conscious beagle dogs, which had been implanted with strain gauge force transducers. Intramuscular administration of E-, S-, or H-CT interrupted gastric migrating motor complexes, digestive pattern, and gastric emptying. The order of potency was E-CT = S-CT > H-CT. Motor inhibition induced by CT occurred independently of plasma immunoreactive motilin levels or hypocalcemia. In addition, E-CT and S-CT induced vomiting without a retrograde giant contraction (RGC) during the postprandial state. Apomorphine or CuSO4 initiated RGC prior to vomiting. RGC induced by apomorphine was inhibited by pretreatment with E-CT as well as hexamethonium, atropine, or surgical vagotomy. E-CT showed no inhibitory effect on nicotine stimulated contraction of isolated guinea-pig ileum. These results suggest that peripherally administered CT inhibits canine gastrointestinal motility at the central nervous system level by lowering vagal activity.

Biomass hydrolysis inhibition at high hydrogen partial pressure in solid-state anaerobic digestion.

Science.gov (United States)

Cazier, E A; Trably, E; Steyer, J P; Escudie, R

2015-08-01

In solid-state anaerobic digestion, so-called ss-AD, biogas production is inhibited at high total solids contents. Such inhibition is likely caused by a slow diffusion of dissolved reaction intermediates that locally accumulate. In this study, we investigated the effect of H2 and CO2 partial pressure on ss-AD. Partial pressure of H2 and/or CO2 was artificially fixed, from 0 to 1 557mbars for H2 and from 0 to 427mbars for CO2. High partial pressure of H2 showed a significant effect on methanogenesis, while CO2 had no impact. At high [Formula: see text] , the overall substrate degradation decreased with no accumulation of metabolites from acidogenic bacteria, indicating that the hydrolytic activity was specifically impacted. Interestingly, such inhibition did not occur when CO2 was added with H2. This result suggests that CO2 gas transfer is probably a key factor in ss-AD from biomass. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synergistic Interactions with PI3K Inhibition that Induce Apoptosis. | Office of Cancer Genomics

Science.gov (United States)

Activating mutations involving the PI3K pathway occur frequently in human cancers. However, PI3K inhibitors primarily induce cell cycle arrest, leaving a significant reservoir of tumor cells that may acquire or exhibit resistance. We searched for genes that are required for the survival of PI3K mutant cancer cells in the presence of PI3K inhibition by conducting a genome scale shRNA-based apoptosis screen in a PIK3CA mutant human breast cancer cell. We identified 5 genes (PIM2, ZAK, TACC1, ZFR, ZNF565) whose suppression induced cell death upon PI3K inhibition.

A Maximum Radius for Habitable Planets.

Science.gov (United States)

Alibert, Yann

2015-09-01

We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

On semidefinite programming relaxations of maximum k-section

NARCIS (Netherlands)

de Klerk, E.; Pasechnik, D.V.; Sotirov, R.; Dobre, C.

2012-01-01

We derive a new semidefinite programming bound for the maximum k -section problem. For k=2 (i.e. for maximum bisection), the new bound is at least as strong as a well-known bound by Poljak and Rendl (SIAM J Optim 5(3):467–487, 1995). For k ≥ 3the new bound dominates a bound of Karisch and Rendl

Modeling multisite streamflow dependence with maximum entropy copula

Science.gov (United States)

Hao, Z.; Singh, V. P.

2013-10-01

Synthetic streamflows at different sites in a river basin are needed for planning, operation, and management of water resources projects. Modeling the temporal and spatial dependence structure of monthly streamflow at different sites is generally required. In this study, the maximum entropy copula method is proposed for multisite monthly streamflow simulation, in which the temporal and spatial dependence structure is imposed as constraints to derive the maximum entropy copula. The monthly streamflows at different sites are then generated by sampling from the conditional distribution. A case study for the generation of monthly streamflow at three sites in the Colorado River basin illustrates the application of the proposed method. Simulated streamflow from the maximum entropy copula is in satisfactory agreement with observed streamflow.

Frequency-Domain Maximum-Likelihood Estimation of High-Voltage Pulse Transformer Model Parameters

CERN Document Server

Aguglia, D; Martins, C.D.A.

2014-01-01

This paper presents an offline frequency-domain nonlinear and stochastic identification method for equivalent model parameter estimation of high-voltage pulse transformers. Such kinds of transformers are widely used in the pulsed-power domain, and the difficulty in deriving pulsed-power converter optimal control strategies is directly linked to the accuracy of the equivalent circuit parameters. These components require models which take into account electric fields energies represented by stray capacitance in the equivalent circuit. These capacitive elements must be accurately identified, since they greatly influence the general converter performances. A nonlinear frequency-based identification method, based on maximum-likelihood estimation, is presented, and a sensitivity analysis of the best experimental test to be considered is carried out. The procedure takes into account magnetic saturation and skin effects occurring in the windings during the frequency tests. The presented method is validated by experim...

The maximum ground level concentration of air pollutant and the effect of plume rise on concentration estimates

International Nuclear Information System (INIS)

Mayhoub, A.B.; Azzam, A.

1991-01-01

The emission of an air pollutant from an elevated point source according to Gaussian plume model has been presented. An elementary theoretical treatment for both the highest possible ground-level concentration and the downwind distance at which this maximum occurs for different stability classes has been constructed. The effective height release modification was taken into consideration. An illustrative case study, namely, the emission from the research reactor in Inchas, has been studied. The results of these analytical treatments and of the derived semi-empirical formulae are discussed and presented in few illustrative diagrams

Inhibition of neutrophil elastase and metalloprotease-9 of human adenocarcinoma gastric cells by chamomile (Matricaria recutita L.) infusion.

Science.gov (United States)

Bulgari, Michela; Sangiovanni, Enrico; Colombo, Elisa; Maschi, Omar; Caruso, Donatella; Bosisio, Enrica; Dell'Agli, Mario

2012-12-01

This study investigated whether the antiinflammatory effect of chamomile infusion at gastric level could be ascribed to the inhibition of metalloproteinase-9 and elastase. The infusions from capitula and sifted flowers (250-1500 µg/mL) and individual flavonoids (10 µM) were tested on phorbol 12-myristate 13-acetate-stimulated AGS cells and human neutrophil elastase. The results indicate that the antiinflammatory activity associated with chamomile infusions from both the capitula and sifted flowers is most likely due to the inhibition of neutrophil elastase and gastric metalloproteinase-9 activity and secretion; the inhibition occurring in a concentration dependent manner. The promoter activity was inhibited as well and the decrease of metalloproteinase-9 expression was found to be associated with the inhibition of NF-kB driven transcription. The results further indicate that the flavonoid-7-glycosides, major constituents of chamomile flowers, may be responsible for the antiinflammatory action of the chamomile infusion observed here. Copyright © 2012 John Wiley & Sons, Ltd.

The Hengill geothermal area, Iceland: variation of temperature gradients deduced from the maximum depth of seismogenesis

Science.gov (United States)

Foulger, G.R.

1995-01-01

Given a uniform lithology and strain rate and a full seismic data set, the maximum depth of earthquakes may be viewed to a first order as an isotherm. These conditions are approached at the Hengill geothermal area, S. Iceland, a dominantly basaltic area. The temperature at which seismic failure ceases for the strain rates likely at the Hengill geothermal area is determined by analogy with oceanic crust, and is about 650 ?? 50??C. The topographies of the top and bottom of the seismogenic layer were mapped using 617 earthquakes. The thickness of the seismogenic layer is roughly constant and about 3 km. A shallow, aseismic, low-velocity volume within the spreading plate boundary that crosses the area occurs above the top of the seismogenic layer and is interpreted as an isolated body of partial melt. The base of the seismogenic layer has a maximum depth of about 6.5 km beneath the spreading axis and deepens to about 7 km beneath a transform zone in the south of the area. -from Author

Maximum stellar iron core mass

Indian Academy of Sciences (India)

60, No. 3. — journal of. March 2003 physics pp. 415–422. Maximum stellar iron core mass. F W GIACOBBE. Chicago Research Center/American Air Liquide ... iron core compression due to the weight of non-ferrous matter overlying the iron cores within large .... thermal equilibrium velocities will tend to be non-relativistic.

GROWTH OF NATURALLY OCCURING Listeria innocua IN COPPA DI TESTA

Directory of Open Access Journals (Sweden)

G. Merialdi

2010-06-01

Full Text Available Coppa di testa is a traditional cooked pork salami produced in different Italian regions. The main raw material is deboned meat of pork head with the addition of tongue and rind. After a long (3-5 h high temperature (97°C cooking, additives and flavourings are added and the salami is prepared. After cooling the salami is often portioned and vacuum- packaged. In this study the growth of naturally occurring contamination of Listeria innocua in three batches of vacuum packaged Coppa di testa, stored at 4°C for 80 days, is described. The average max was 0.24 (days-1 and the average doubling time was 2.87 days. The maximum growth level ranged from 4.90 to 8.17 (log10 cfu/g. These results indicate that Coppa di testa definitely supports the growth of Listeria innocua in the considered storage conditions. Taking into account that at 4°C Listeria monocytogenes strains are associated with higher grow rates than L. innocua, these results emphasize the importance of preventing Listeria monocytogenes contamination in the production stages following cooking.

Occurance and distribution of poty viruses infecting garlic in Pakistan

International Nuclear Information System (INIS)

Gilani, S.T.; Hameed, S.; Shah, H.

2016-01-01

The study was designed to detect and determine the prevalence, incidence and distribution of the poty viruses causing diseases in garlic (Allium sativum) from major garlic growing areas of Pakistan. The yellow stripes, mosaic and chlorotic spot symptoms of the disease resemble the viral infection in garlic reported to occur worldwide. Altogether 690 samples were collected from 29 locations of Punjab and 40 locations of Khyber Pukhtunkhwa to determine the prevalence of Onion Yellow Dwarf Virus (OYDV) and Leek Yellow Stripe Virus (LYSV). Serological testing DAS-ELISA technique was used to test the samples collected from the farmer fields. Based on the DAS-ELISA poty viruses OYDV and LYSV were detected from both provinces although the percentage incidence varied from location to location. Few areas of district Punjab were found free of LYSV but OYDV was prevalent in all locations irrespective of the varieties cultivated. Maximum disease incidence was detected in Swabi (KPK) where OYDV was 90percent and LYSV was 38 percent while in Punjab major disease incidence of OYDV (87.14 percent) and LYSV (91.44 percent) was found in Sialkot. (author)

Caffeine inhibits homology-directed repair of I-SceI-induced DNA double-strand breaks.

Science.gov (United States)

Wang, Huichen; Boecker, Wilfried; Wang, Hongyan; Wang, Xiang; Guan, Jun; Thompson, Larry H; Nickoloff, Jac A; Iliakis, George

2004-01-22

We recently reported that two Chinese hamster mutants deficient in the RAD51 paralogs XRCC2 and XRCC3 show reduced radiosensitization after treatment with caffeine, thus implicating homology-directed repair (HDR) of DNA double-strand breaks (DSBs) in the mechanism of caffeine radiosensitization. Here, we investigate directly the effect of caffeine on HDR initiated by DSBs induced by a rare cutting endonuclease (I-SceI) into one of two direct DNA repeats. The results demonstrate a strong inhibition by caffeine of HDR in wild-type cells, and a substantial reduction of this effect in HDR-deficient XRCC3 mutant cells. Inhibition of HDR and cell radiosensitization to killing shows similar dependence on caffeine concentration suggesting a cause-effect relationship between these effects. UCN-01, a kinase inhibitor that effectively abrogates checkpoint activation in irradiated cells, has only a small effect on HDR, indicating that similar to radiosensitization, inhibition of checkpoint signaling is not sufficient for HDR inhibition. Recombination events occurring during treatment with caffeine are characterized by rearrangements reminiscent to those previously reported for the XRCC3 mutant, and immunofluorescence microscopy demonstrates significantly reduced formation of IR-specific RAD51 foci after caffeine treatment. In summary, our results identify inhibition of HDR as a significant contributor to caffeine radiosensitization.

The inhibition effect and mechanism of L-cysteine on the corrosion of bronze covered with a CuCl patina

International Nuclear Information System (INIS)

Wang, Tianran; Wang, Julin; Wu, Yuqing

2015-01-01

Highlights: • CuCl patina was synthesized on bronze electrodes with electrochemical method. • L-cysteine was used as a green inhibitor for bronze covered with CuCl patina. • The inhibition efficiency reached above 90%. • The inhibition mechanism of L-cysteine on CuCl patina was investigated. - Abstract: CuCl patina was synthesized on bronze electrodes with electrochemical method. The inhibition effect and mechanism of L-cysteine (Cys) on bronze covered with CuCl patina have been studied with electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) techniques. The EIS results show that Cys stabilized the CuCl patina to a great extent. The hydrolysis reaction of CuCl was inhibited effectively and an inhibition efficiency of over 90% was achieved. The XPS analyses indicate that the chemisorption of Cys molecules on CuCl surface occurred through sulfur atom in thiol and nitrogen atom in amino group

Uranium occurence in nature: Geophysical prospecting, and its occurence in Syria

International Nuclear Information System (INIS)

Al-Haj Rasheed, Zaki

1985-01-01

A general idea about naturaly occured uranium minerals such as uranite, pechblende, carnotite, coffinit, and bronnerit is given. At the same time, different geophysical methods and detecting devices applied for uranium exploration have been demonstrated. Investigations and studies carried out in Syria point to a uranium content of 100 ppm in the exploited Syrian phosphorite. 1 fig., 1 tab

Inhibition and recovery of the rate of DNA synthesis in V79 Chinese hamster cells following ultraviolet light irradiation

International Nuclear Information System (INIS)

Ventura, A.M.; Meneghini, R.

1984-01-01

Chinese hamster fibroblasts (V79 cell line) exhibit the phenomenon of recovery of DNA synthesis from the initial inhibition observed after ultraviolet light irradiation, in the absence of significant excision of pyrimidine dimers. In an attempt to determine whether the initial inhibition and subsequent recovery can be accounted for by parallel variations in the rate of movement of the replication fork, the cells were pulse-labeled with radioactive bromodeoxyuridine at different times following irradiation and their DNA centrifuged in neutral CsCl density gradients. When DNA synthesis inhibition was at a maximum, an accumulation of DNA, of density intermediate between hybrid and nonsubstituted DNA, was noticed in the density-distribution profiles. The density distribution of DNA along the gradient can provide an estimate of the rate of movement of the replication fork, and the results indicate that most of the variation in the overall rate of DNA synthesis can be accounted for by a parallel variation in the rate of fork movement. (Auth.)

The regulation of starch accumulation in Panicum maximum Jacq ...

African Journals Online (AJOL)

... decrease the starch level. These observations are discussed in relation to the photosynthetic characteristics of P. maximum. Keywords: accumulation; botany; carbon assimilation; co2 fixation; growth conditions; mesophyll; metabolites; nitrogen; nitrogen levels; nitrogen supply; panicum maximum; plant physiology; starch; ...

Fatigue life prediction method for contact wire using maximum local stress

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Seok; Haochuang, Li; Seok, Chang Sung; Koo, Jae Mean [Sungkyunkwan University, Suwon (Korea, Republic of); Lee, Ki Won; Kwon, Sam Young; Cho, Yong Hyeon [Korea Railroad Research Institute, Uiwang (Korea, Republic of)

2015-01-15

Railway contact wires supplying electricity to trains are exposed to repeated mechanical strain and stress caused by their own weight and discontinuous contact with a pantograph during train operation. Since the speed of railway transportation has increased continuously, railway industries have recently reported a number of contact wire failures caused by mechanical fatigue fractures instead of normal wear, which has been a more common failure mechanism. To secure the safety and durability of contact wires in environments with increased train speeds, a bending fatigue test on contact wire has been performed. The test equipment is too complicated to evaluate the fatigue characteristics of contact wire. Thus, the axial tension fatigue test was performed for a standard specimen, and the bending fatigue life for the contact wire structure was then predicted using the maximum local stress occurring at the top of the contact wire. Lastly, the tested bending fatigue life of the structure was compared with the fatigue life predicted by the axial tension fatigue test for verification.

Fatigue life prediction method for contact wire using maximum local stress

International Nuclear Information System (INIS)

Kim, Yong Seok; Haochuang, Li; Seok, Chang Sung; Koo, Jae Mean; Lee, Ki Won; Kwon, Sam Young; Cho, Yong Hyeon

2015-01-01

Railway contact wires supplying electricity to trains are exposed to repeated mechanical strain and stress caused by their own weight and discontinuous contact with a pantograph during train operation. Since the speed of railway transportation has increased continuously, railway industries have recently reported a number of contact wire failures caused by mechanical fatigue fractures instead of normal wear, which has been a more common failure mechanism. To secure the safety and durability of contact wires in environments with increased train speeds, a bending fatigue test on contact wire has been performed. The test equipment is too complicated to evaluate the fatigue characteristics of contact wire. Thus, the axial tension fatigue test was performed for a standard specimen, and the bending fatigue life for the contact wire structure was then predicted using the maximum local stress occurring at the top of the contact wire. Lastly, the tested bending fatigue life of the structure was compared with the fatigue life predicted by the axial tension fatigue test for verification.

In vitro screening of reversible and time-dependent inhibition on CYP3A by TM208 and TM209 in rat liver microsomes

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Miaoran Ning

2012-04-01

Full Text Available TM208 and TM209, dithiocarbamate derivatives with potential anti-cancer effects, were evaluated in reversible and time-dependent cytochrome P450 (CYP 3A inhibition assays in rat liver microsomes using testosterone as probe substrate. Both compounds were found to be weak reversible inhibitors and moderate mechanism-based inhibitors of rat CYP3A. For reversible inhibition on rat CYP3A, the Ki values of competitive inhibition model were 12.10±1.75 and 13.94±1.31 μM, respectively. For time-dependent inhibition, the inactivation constants (Kl were 31.93±12.64 and 32.91±15.58 μM, respectively, and the maximum inactivation rates (kinact were 0.03497±0.0069 and 0.07259±0.0172 min−1 respectively. These findings would provide useful in vitro information for future in vivo DDI studies on TM208 or TM209.

Picomolar-affinity binding and inhibition of adenylate cyclase activity by melatonin in Syrian hamster hypothalamus

International Nuclear Information System (INIS)

Niles, L.P.; Hashemi, F.

1990-01-01

1. The effect of melatonin on forskolin-stimulated adenylate cyclase activity was measured in homogenates of Syrian hamster hypothalamus. In addition, the saturation binding characteristics of the melatonin receptor ligand, [ 125 I]iodomelatonin, was examined using an incubation temperature (30 degree C) similar to that used in enzyme assays. 2. At concentrations ranging from 10 pM to 1 nM, melatonin caused a significant decrease in stimulated adenylate cyclase activity with a maximum inhibition of approximately 22%. 3. Binding experiments utilizing [ 125 I]iodomelatonin in a range of approximately 5-80 pM indicated a single class of high-affinity sites: Kd = 55 +/- 9 pM, Bmax = 1.1 +/- 0.3 fmol/mg protein. 4. The ability of picomolar concentrations of melatonin to inhibit forskolin-stimulated adenylate cyclase activity suggests that this affect is mediated by picomolar-affinity receptor binding sites for this hormone in the hypothalamus

Maximum entropy beam diagnostic tomography

International Nuclear Information System (INIS)

Mottershead, C.T.

1985-01-01

This paper reviews the formalism of maximum entropy beam diagnostic tomography as applied to the Fusion Materials Irradiation Test (FMIT) prototype accelerator. The same formalism has also been used with streak camera data to produce an ultrahigh speed movie of the beam profile of the Experimental Test Accelerator (ETA) at Livermore. 11 refs., 4 figs

A portable storage maximum thermometer

International Nuclear Information System (INIS)

Fayart, Gerard.

1976-01-01

A clinical thermometer storing the voltage corresponding to the maximum temperature in an analog memory is described. End of the measurement is shown by a lamp switch out. The measurement time is shortened by means of a low thermal inertia platinum probe. This portable thermometer is fitted with cell test and calibration system [fr

A Maximum Resonant Set of Polyomino Graphs

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Zhang Heping

2016-05-01

Full Text Available A polyomino graph P is a connected finite subgraph of the infinite plane grid such that each finite face is surrounded by a regular square of side length one and each edge belongs to at least one square. A dimer covering of P corresponds to a perfect matching. Different dimer coverings can interact via an alternating cycle (or square with respect to them. A set of disjoint squares of P is a resonant set if P has a perfect matching M so that each one of those squares is M-alternating. In this paper, we show that if K is a maximum resonant set of P, then P − K has a unique perfect matching. We further prove that the maximum forcing number of a polyomino graph is equal to the cardinality of a maximum resonant set. This confirms a conjecture of Xu et al. [26]. We also show that if K is a maximal alternating set of P, then P − K has a unique perfect matching.

Fructose effect to enhance liver glycogen deposition is due to inhibition of glycogenolysis

International Nuclear Information System (INIS)

Youn, J.; Kaslow, H.; Bergman, R.

1987-01-01

The effect of fructose on glycogen degradation was examined by measuring flux of [ 14 C] from prelabeled glycogen in perfused rat livers. During 2 h refeeding of fasted rats hepatic glycogen was labeled by injection of [U 14 C] galactose (0.1 mg and 0.02 μCi/g of body weight). Refed livers were perfused for 30 min with glucose only (10 mM) and for 60 min with glucose (10 mM) without (n=5) or with fructose (1, 2, 10 mM; n=5 for each). With fructose, label production immediately declined and remained suppressed through the end of perfusion (P < 0.05). Suppression was dose-dependent: steady state label production was suppressed 45, 64, and 72% by 1, 2, and 10 mM fructose (P < 0.0001), without significant changes in glycogen synthase or phosphorylase. These results suggest the existence of allosteric inhibition of phosphorylase in the presence of fructose. Fructose 1-phosphate (F1P) accumulated in proportion to fructose (0.11 +/- 0.01 without fructose, 0.86 +/- 0.03, 1.81 +/- 0.18, and 8.23 +/- 0.6 μmoles/g of liver with 1, 2, and 10 mM fructose. Maximum inhibition of phosphorylase was 82%; FIP concentration for half inhibition was 0.57 μmoles/g of liver, well within the concentration of F1P attained in refeeding. Fructose enhances net glycogen synthesis in liver by suppressing glycogenolysis and the suppression is presumably caused by allosteric inhibition of phosphorylase by F1P

Spatio-temporal observations of the tertiary ozone maximum

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V. F. Sofieva

2009-07-01

Full Text Available We present spatio-temporal distributions of the tertiary ozone maximum (TOM, based on GOMOS (Global Ozone Monitoring by Occultation of Stars ozone measurements in 2002–2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at an altitude of ~72 km. Although the explanation for this phenomenon has been found recently – low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses – models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time to obtain spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere.

The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory, TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of the tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model and found that the specific features are reproduced satisfactorily by the model.

Since ozone in the mesosphere is very sensitive to HO_x concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HO_x enhancement from the increased ionization.

Herbal extracts of Tribulus terrestris and Bergenia ligulata inhibit growth of calcium oxalate monohydrate crystals in vitro

Science.gov (United States)

Joshi, V. S.; Parekh, B. B.; Joshi, M. J.; Vaidya, A. B.

2005-02-01

A large number of people in this world are suffering from urinary stone problem. Calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) containing stones (calculi) are commonly found. In the present study, COM crystals were grown by a double diffusion gel growth technique using U-tubes. The gel was prepared from hydrated sodium metasilicate solution. The gel framework acts like a three-dimensional crucible in which the crystal nuclei are delicately held in the position of their formation, and nutrients are supplied for the growth. This technique can be utilized as a simplified screening static model to study the growth, inhibition and dissolution of urinary stones in vitro. The action of putative litholytic medicinal plants, Tribulus terrestris Linn. ( T.t) and Bergenia ligulata Linn. ( B.l.), has been studied in the growth of COM crystals. Tribulus terrestris and Bergenia ligulata are commonly used as herbal medicines for urinary calculi in India. To verify the inhibitive effect, aqueous extracts of Tribulus terrestris and Bergenia ligulata were added along with the supernatant solutions. The growth was measured and compared, with and without the aqueous extracts. Inhibition of COM crystal growth was observed in the herbal extracts. Maximum inhibition was observed in Bergenia ligulata followed by Tribulus terrestris. The results are discussed.

Hypothesis: holiday sudden cardiac death: food and alcohol inhibition of SULT1A enzymes as a precipitant.

Science.gov (United States)

Eagle, Ken

2012-10-01

Sudden cardiac death is a significant health issue, causing millions of deaths worldwide annually. Studies have found that the likelihood of such death is higher in winter. Further studies identified that the highest likelihood occurs on Christmas Day and New Years Day, but not the interim period. Thanksgiving, Independence Day and the Islamic holiday Eid Al-Fitr also show significant increases in the rate of cardiac events or death. A number of mechanisms have been proposed, but none have satisfactorily explained the evidence. This article reviews the data supporting the existence of a holiday cardiac death phenomenon, the involvement of catecholamines and the normal modes of human catecholamine deactivation. Further evidence is reviewed that supports a hypothesized mechanism whereby critical SULT1A catecholamine deactivation enzymes can in some patients be inhibited by naturally-occurring phenols and polyphenols in foods and alcohols. If deactivation is inhibited by holiday consumption excesses, holiday stress or excitement could lead to a buildup of catecholamines that can cause fatal arrhythmias. Awareness of this mechanism could reduce deaths, both through doctor/patient education leading to a moderation in consumption and through the potential identification of patients with a predisposition to SULT1A inhibition. This hypothesis also raises parallels between sudden cardiac death in adults and Sudden Infant Death Syndrome (SIDS). The possible involvement of SULT1A inhibition in SIDS is discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Hypothesis Holiday sudden cardiac death: food and alcohol inhibition of SULT1A enzymes as a precipitant

Science.gov (United States)

Eagle, Ken

2012-01-01

Sudden cardiac death is a significant health issue, causing millions of deaths worldwide annually. Studies have found that the likelihood of such death is higher in winter. Further studies identified that the highest likelihood occurs on Christmas Day and New Years Day, but not the interim period. Thanksgiving, Independence Day and the Islamic holiday Eid Al-Fitr also show significant increases in the rate of cardiac events or death. A number of mechanisms have been proposed, but none have satisfactorily explained the evidence. This article reviews the data supporting the existence of a holiday cardiac death phenomenon, the involvement of catecholamines and the normal modes of human catecholamine deactivation. Further evidence is reviewed that supports a hypothesized mechanism whereby critical SULT1A catecholamine deactivation enzymes can in some patients be inhibited by naturally-occurring phenols and polyphenols in foods and alcohols. If deactivation is inhibited by holiday consumption excesses, holiday stress or excitement could lead to a buildup of catecholamines that can cause fatal arrhythmias. Awareness of this mechanism could reduce deaths, both through doctor/patient education leading to a moderation in consumption and through the potential identification of patients with a predisposition to SULT1A inhibition. This hypothesis also raises parallels between sudden cardiac death in adults and Sudden Infant Death Syndrome (SIDS). The possible involvement of SULT1A inhibition in SIDS is discussed. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22678655

Oxidation mechanisms occurring in wines

OpenAIRE

Oliveira, Carla Maria; Ferreira, António César Silva; Freitas, Victor De; Silva, Artur M. S.

2011-01-01

The present review aims to show the state of the art on the oxidation mechanisms occurring in wines, as well as the methods to monitor, classify and diagnose wine oxidation. Wine oxidation can be divided in enzymatic oxidation and non-enzymatic oxidation. Enzymatic oxidation almost entirely occurs in grape must and is largely correlated with the content of hydroxycinnamates, such as caffeoyltartaric acid and paracoumaroyltartaric acid, and flavan-3-ols. Non-enzymatic oxidation, al...

Corollary discharge inhibition of wind-sensitive cercal giant interneurons in the singing field cricket

Science.gov (United States)

Hedwig, Berthold

2014-01-01

Crickets carry wind-sensitive mechanoreceptors on their cerci, which, in response to the airflow produced by approaching predators, triggers escape reactions via ascending giant interneurons (GIs). Males also activate their cercal system by air currents generated due to the wing movements underlying sound production. Singing males still respond to external wind stimulation, but are not startled by the self-generated airflow. To investigate how the nervous system discriminates sensory responses to self-generated and external airflow, we intracellularly recorded wind-sensitive afferents and ventral GIs of the cercal escape pathway in fictively singing crickets, a situation lacking any self-stimulation. GI spiking was reduced whenever cercal wind stimulation coincided with singing motor activity. The axonal terminals of cercal afferents showed no indication of presynaptic inhibition during singing. In two ventral GIs, however, a corollary discharge inhibition occurred strictly in phase with the singing motor pattern. Paired intracellular recordings revealed that this inhibition was not mediated by the activity of the previously identified corollary discharge interneuron (CDI) that rhythmically inhibits the auditory pathway during singing. Cercal wind stimulation, however, reduced the spike activity of this CDI by postsynaptic inhibition. Our study reveals how precisely timed corollary discharge inhibition of ventral GIs can prevent self-generated airflow from triggering inadvertent escape responses in singing crickets. The results indicate that the responsiveness of the auditory and wind-sensitive pathway is modulated by distinct CDIs in singing crickets and that the corollary discharge inhibition in the auditory pathway can be attenuated by cercal wind stimulation. PMID:25318763

Exposure to polystyrene nanoplastic leads to inhibition of anaerobic digestion system.

Science.gov (United States)

Fu, Shan-Fei; Ding, Jian-Nan; Zhang, Yun; Li, Yi-Fei; Zhu, Rong; Yuan, Xian-Zheng; Zou, Hua

2018-06-01

In this study, impacts of nanoplastic on the pure and mixed anaerobic digestion systems were investigated. Results showed the growth and metabolism of Acetobacteroides hydrogenigenes were partly inhibited by nanoplastic existed in the pure anaerobic digestion system. The anaerobic digestion of sewage sludge was also obviously inhibited by nanoplastic existed in the mixed anaerobic digestion system. Both the methane yield and methane production rate of the mixed anaerobic digestion system showed negative correlation with the nanoplastic concentration. Compared with anaerobic digestion system without nanoplastic, methane yield and maximum daily methane yield at the nanoplastic concentration of 0.2g/L decreased for 14.4% and 40.7%, respectively. In addition, the start-up of mixed anaerobic digestion system was prolonged by addition of nanoplastic. Microbial community structure analysis indicated the microbial community structures were also affected by nanoplastic existed in the system. At the nanoplastic concentration of 0.2g/L, the relative abundances of family Cloacamonaceae, Porphyromonadaceae, Anaerolinaceae and Gracilibacteraceae decreased partly. Conversely, the relative abundances of family Anaerolinaceae, Clostridiaceae, Geobacteraceae, Dethiosulfovibrionaceae and Desulfobulbaceae improved partly. Copyright © 2017 Elsevier B.V. All rights reserved.

Calculating the Prior Probability Distribution for a Causal Network Using Maximum Entropy: Alternative Approaches

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Michael J. Markham

2011-07-01

Full Text Available Some problems occurring in Expert Systems can be resolved by employing a causal (Bayesian network and methodologies exist for this purpose. These require data in a specific form and make assumptions about the independence relationships involved. Methodologies using Maximum Entropy (ME are free from these conditions and have the potential to be used in a wider context including systems consisting of given sets of linear and independence constraints, subject to consistency and convergence. ME can also be used to validate results from the causal network methodologies. Three ME methods for determining the prior probability distribution of causal network systems are considered. The first method is Sequential Maximum Entropy in which the computation of a progression of local distributions leads to the over-all distribution. This is followed by development of the Method of Tribus. The development takes the form of an algorithm that includes the handling of explicit independence constraints. These fall into two groups those relating parents of vertices, and those deduced from triangulation of the remaining graph. The third method involves a variation in the part of that algorithm which handles independence constraints. Evidence is presented that this adaptation only requires the linear constraints and the parental independence constraints to emulate the second method in a substantial class of examples.

Studies of the pressure dependence of the charge density distribution in cerium phosphide by the maximum-entropy method

CERN Document Server

Ishimatsu, N; Takata, M; Nishibori, E; Sakata, M; Hayashi, J; Shirotani, I; Shimomura, O

2002-01-01

The physical properties relating to 4f electrons in cerium phosphide, especially the temperature dependence and the isomorphous transition that occurs at around 10 GPa, were studied by means of x-ray powder diffraction and charge density distribution maps derived by the maximum-entropy method. The compressibility of CeP was exactly determined using a helium pressure medium and the anomaly that indicated the isomorphous transition was observed in the compressibility. We also discuss the anisotropic charge density distribution of Ce ions and its temperature dependence.

Inhibition effect of tetradecylpyridinium bromide on the corrosion of cold rolled steel in 7.0 M H3PO4

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Xianghong Li

2017-05-01

Full Text Available Inhibition effect of cationic surfactant of tetradecylpyridinium bromide (TDPB on the corrosion of cold rolled steel (CRS in phosphoric acid produced by dihydrate wet method process (7.0 M H3PO4 was investigated by weight loss and potentiodynamic polarization methods and electrochemical impedance spectroscopy (EIS and scanning electron microscopy (SEM. Quantum chemical calculation was applied to elucidate the adsorption mode of the inhibitor molecule on steel surface. The results show that TDPB acts as a good inhibitor, and its maximum inhibition efficiency is higher than 90% even at low concentration. The adsorption of TDPB obeys the Langmuir adsorption isotherm equation. Polarization curves indicate that TDPB behaves as a mixed-type inhibitor in H3PO4. EIS spectra exhibit one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process. The inhibition action of TDPB could also be evidenced by surface SEM images. Density functional theory (DFT calculations suggest that the pyridine ring is the active adsorption center. Depending on the results, the inhibitive mechanism is proposed from the viewpoint of adsorption theory.

Inhibition of S-adenosylmethionine decarboxylase and diamine oxidase activities by analogues of methylglyoxal bis(guanylhydrazone) and their cellular uptake during lymphocyte activation.

Science.gov (United States)

Jänne, J; Morris, D R

1984-03-15

Several congeners of methylglyoxal bis(guanylhydrazone) were tested for their ability to inhibit eukaryotic putrescine-activated S-adenosylmethionine decarboxylase (EC 4.1.1.50) and intestinal diamine oxidase (EC 1.4.3.6). All the compounds tested, namely methylglyoxal bis(guanylhydrazone), ethylglyoxal bis(guanylhydrazone), dimethylglyoxal bis(guanylhydrazone) and the di-N"-methyl derivative of methylglyoxal bis(guanylhydrazone), were strong inhibitors of both yeast and mouse liver adenosylmethionine decarboxylase activity in vitro. The enzyme from both sources was most powerfully inhibited by ethylglyoxal bis(guanylhydrazone). All the diguanidines likewise inhibited diamine oxidase activity in vitro. The maximum intracellular concentrations of the ethyl and dimethylated analogues achieved in activated lymphocytes were only about one-fifth of that of the parent compound. However, both derivatives appeared to utilize the polyamine-carrier system, as indicated by competition experiments with spermidine.

Optogenetic Inhibition Reveals Distinct Roles for Basolateral Amygdala Activity at Discrete Time Points during Risky Decision Making.

Science.gov (United States)

Orsini, Caitlin A; Hernandez, Caesar M; Singhal, Sarthak; Kelly, Kyle B; Frazier, Charles J; Bizon, Jennifer L; Setlow, Barry

2017-11-29

Decision making is a multifaceted process, consisting of several distinct phases that likely require different cognitive operations. Previous work showed that the basolateral amygdala (BLA) is a critical substrate for decision making involving risk of punishment; however, it is unclear how the BLA is recruited at different stages of the decision process. To this end, the current study used optogenetics to inhibit the BLA during specific task phases in a model of risky decision making (risky decision-making task) in which rats choose between a small, "safe" reward and a large reward accompanied by varying probabilities of footshock punishment. Male Long-Evans rats received intra-BLA microinjections of viral vectors carrying either halorhodopsin (eNpHR3.0-mCherry) or mCherry alone (control) followed by optic fiber implants and were trained in the risky decision-making task. Laser delivery during the task occurred during intertrial interval, deliberation, or reward outcome phases, the latter of which was further divided into the three possible outcomes (small, safe; large, unpunished; large, punished). Inhibition of the BLA selectively during the deliberation phase decreased choice of the large, risky outcome (decreased risky choice). In contrast, BLA inhibition selectively during delivery of the large, punished outcome increased risky choice. Inhibition had no effect during the other phases, nor did laser delivery affect performance in control rats. Collectively, these data indicate that the BLA can either inhibit or promote choice of risky options, depending on the phase of the decision process in which it is active. SIGNIFICANCE STATEMENT To date, most behavioral neuroscience research on neural mechanisms of decision making has used techniques that preclude assessment of distinct phases of the decision process. Here we show that optogenetic inhibition of the BLA has opposite effects on choice behavior in a rat model of risky decision making, depending on the phase

Direct maximum parsimony phylogeny reconstruction from genotype data

OpenAIRE

Sridhar, Srinath; Lam, Fumei; Blelloch, Guy E; Ravi, R; Schwartz, Russell

2007-01-01

Abstract Background Maximum parsimony phylogenetic tree reconstruction from genetic variation data is a fundamental problem in computational genetics with many practical applications in population genetics, whole genome analysis, and the search for genetic predictors of disease. Efficient methods are available for reconstruction of maximum parsimony trees from haplotype data, but such data are difficult to determine directly for autosomal DNA. Data more commonly is available in the form of ge...

Experimental and theoretical investigation on corrosion inhibition of AA5052 aluminium alloy by L-cysteine in alkaline solution

International Nuclear Information System (INIS)

Wang, Dapeng; Gao, Lixin; Zhang, Daquan; Yang, Dong; Wang, Hongxia; Lin, Tong

2016-01-01

The corrosion inhibition of L-cysteine on AA5052 aluminium alloy in 4 mol/L NaOH solution was investigated by hydrogen gas evolution experiment, polarisation curve, galvanostatic discharge, electrochemical impedance spectroscopy measurements and quantum chemical calculations. The adsorption of L-cysteine on aluminium alloy surface obeyed the amended Langmuir's adsorption isotherm. The polarisation curves indicated that L-cysteine acted as a cathodic inhibitor to inhibit cathodic reaction. The inhibition mechanism was dominated by the geometric covering effect. The galvanostatic discharge shows that the additives restrain the hydrogen evolution and increase the anodic utilization rate. Quantum chemical calculations indicated that L-cysteine molecules mainly interacted with on the carboxyl groups on the aluminium alloy surface. A strong hybridization occurred between the s-orbital and p-orbital of reactive sites in the L-cysteine molecule and the sp-orbital of Aluminium. - Highlights: • L-cysteine was used as corrosion inhibitor for Al alloy in alkaline solution. • Adsorption of L-cysteine on Al alloy surface obeyed the amended Langmuir's isotherm. • L-cysteine molecules interacted with the carboxyl groups on the Al alloy surface. • A strong orbital hybridization occurred between the reactive sites in L-cysteine and Al.

Should we stop thinking about inhibition? Searching for individual and age differences in inhibition ability.

Science.gov (United States)

Rey-Mermet, Alodie; Gade, Miriam; Oberauer, Klaus

2018-04-01

Inhibition is often conceptualized as a unitary construct reflecting the ability to ignore and suppress irrelevant information. At the same time, it has been subdivided into inhibition of prepotent responses (i.e., the ability to stop dominant responses) and resistance to distracter interference (i.e., the ability to ignore distracting information). The present study investigated the unity and diversity of inhibition as a psychometric construct, and tested the hypothesis of an inhibition deficit in older age. We measured inhibition in young and old adults with 11 established laboratory tasks: antisaccade, stop-signal, color Stroop, number Stroop, arrow flanker, letter flanker, Simon, global-local, positive and negative compatibility tasks, and n-2 repetition costs in task switching. In both age groups, the inhibition measures from individual tasks had good reliabilities, but correlated only weakly among each other. Structural equation modeling identified a 2-factor model with factors for inhibition of prepotent responses and resistance to distracter interference. Older adults scored worse in the inhibition of prepotent response, but better in the resistance to distracter interference. However, the model had low explanatory power. Together, these findings call into question inhibition as a psychometric construct and the hypothesis of an inhibition deficit in older age. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Fungic microflora of Panicum maximum and Styosanthes spp. commercial seed / Microflora fúngica de sementes comerciais de Panicum maximum e Stylosanthes spp.

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Larissa Rodrigues Fabris

2010-09-01

Full Text Available The sanitary quality of 26 lots commercial seeds of tropical forages, produced in different regions (2004-05 and 2005-06 was analyzed. The lots were composed of seeds of Panicum maximum ('Massai', 'Mombaça' e 'Tanzânia' and stylo ('Estilosantes Campo Grande' - ECG. Additionally, seeds of two lots of P. maximum for exportation were analyzed. The blotter test was used, at 20ºC under alternating light and darkness in a 12 h photoperiod, for seven days. The Aspergillus, Cladosporium and Rhizopus genus consisted the secondary or saprophytes fungi (FSS with greatest frequency in P. maximum lots. In general, there was low incidence of these fungus in the seeds. In relation to pathogenic fungi (FP, it was detected high frequency of contaminated lots by Bipolaris, Curvularia, Fusarium and Phoma genus. Generally, there was high incidence of FP in P. maximum seeds. The occurrence of Phoma sp. was hight, because in 81% of the lots showed incidence superior to 50%. In 'ECG' seeds it was detected FSS (Aspergillus, Cladosporium, and Penicillium genus and FP (Bipolaris, Curvularia, Fusarium and Phoma genus, usually, in low incidence. FSS and FP were associated to P. maximum seeds for exportation, with significant incidence in some cases. The results indicated that there was a limiting factor in all producer regions regarding sanitary quality of the seeds.Sementes comerciais de forrageiras tropicais, pertencente a 26 lotes produzidos em diferentes regiões (safras 2004-05 e 2005-06, foram avaliadas quanto à sanidade. Foram analisadas sementes de cultivares de Panicum maximum (Massai, Mombaça e Tanzânia e de estilosantes (Estilosantes Campo Grande – ECG. Adicionalmente, avaliou-se a qualidade sanitária de dois lotes de sementes de P. maximum destinados à exportação. Para isso, as sementes foram submetidas ao teste de papel de filtro em gerbox, os quais foram incubados a 20ºC, com fotoperíodo de 12 h, durante sete dias. Os fungos saprófitos ou

Echinocystic acid inhibits RANKL-induced osteoclastogenesis by regulating NF-κB and ERK signaling pathways

Energy Technology Data Exchange (ETDEWEB)

Yang, Jian-hui, E-mail: jianhui_yangxa@163.com [Rehabilitation Center, First Affiliated Hospital of Health Science Center, Xi’an Jiaotong University, Xi’an, 710061, Shaanxi Province (China); Li, Bing [Department of Dermatology, the 451st Hospital of People’s Liberation Army, Xi’an 710054, Shaanxi Province (China); Wu, Qiong; Lv, Jian-guo; Nie, Hui-Yong [Rehabilitation Center, First Affiliated Hospital of Health Science Center, Xi’an Jiaotong University, Xi’an, 710061, Shaanxi Province (China)

2016-09-02

Receptor activator of nuclear factor-κB ligand (RANKL) is a key factor in the differentiation and activation of osteoclasts. Echinocystic acid (EA), a pentacyclic triterpene isolated from the fruits of Gleditsia sinensis Lam, was reported to prevent reduction of bone mass and strength and improve the cancellous bone structure and biochemical properties in ovariectomy rats. However, the molecular mechanism of EA on the osteoclast formation has not been reported. The purpose of this study was to investigate the effects and mechanism of EA on RANKL-induced osteoclastogenesis. Our results showed that EA inhibited the formation of osteoclast, as well as the expression of osteoclastogenesis-related marker proteins in bone marrow macrophages (BMMs). At molecular levels, EA inhibited RANKL-induced NF-κB activation and ERK phosphorylation in BMMs. In conclusion, the present study demonstrated that EA can suppress osteoclastogenesis in vitro. Moreover, we clarified that these inhibitory effects of EA occur through suppression of NF-κB and ERK activation. Therefore, EA may be a potential agent in the treatment of osteoclast-related diseases such as osteoporosis. - Highlights: • EA inhibited the formation of osteoclast in BMMs. • EA inhibits the expression of osteoclastogenesis-related marker proteins in BMMs. • EA inhibits RANKL-induced NF-κB activation in BMMs. • EA inhibits RANKL-induced ERK phosphorylation in BMMs.

Carbamazepine (Tegretol) inhibits in vivo iodide uptake and hormone synthesis in rat thyroid glands

International Nuclear Information System (INIS)

Villa, S.M.; Alexander, N.M.

1987-01-01

Decreased serum concentrations of T3 and T4 occur in patients treated with the anticonvulsant drug carbamazepine (CBZ), but with rare exception, these patients remain euthyroid. The mechanism that accounts for diminished hormone levels is unknown, and our objective was to study the direct effect of CBZ on iodide uptake and hormone synthesis in thyroid glands of CBZ-treated and pair-fed control rats. Chronic ingestion (per os) of CBZ in male rats reduced the four hour thyroid 131I-iodide uptake by approximately 60%. This inhibition occurred after the animals had received sufficient CBZ to attain plasma CBZ concentrations of 0.8 microgram/ml. Continued treatment with CBZ ranging from 560 to 800 mg/kg/day for 14 days did not result in further inhibition of iodide uptake even though the plasma CBZ concentrations had increased 6-20 fold. No inhibition of iodide uptake was apparent when the animals initially received CBZ ranging from 40 to 152 mg/kg body weight for 22 days when there were no detectable levels of plasma CBZ. Overall growth rates of CBZ-treated rats were slightly (6-10%) less than the pair-fed control animals. Plasma T4 concentrations were reduced by 18% (p less than 0.05) in the CBZ-fed animals, while T3 concentrations were diminished by 53% (p less than 0.01). CBZ appeared to alter thyroidal iodide transport because the thyroid:plasma iodide ratios were decreased by 26% in the drug-treated rats. The distribution of radioiodine in thyroidal iodoamino acids was essentially the same in both groups of rats but the absolute quantities of radioiodine were more than 2.5 times greater in the control rats. CBZ failed to inhibit peroxidase-catalyzed iodide and guaiacol oxidation in vitro

78 FR 49370 - Inflation Adjustment of Maximum Forfeiture Penalties

Science.gov (United States)

2013-08-14

... ``civil monetary penalties provided by law'' at least once every four years. DATES: Effective September 13... increases the maximum civil monetary forfeiture penalties available to the Commission under its rules... maximum civil penalties established in that section to account for inflation since the last adjustment to...

5 CFR 838.711 - Maximum former spouse survivor annuity.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Maximum former spouse survivor annuity... Orders Awarding Former Spouse Survivor Annuities Limitations on Survivor Annuities § 838.711 Maximum former spouse survivor annuity. (a) Under CSRS, payments under a court order may not exceed the amount...

A tropospheric ozone maximum over the equatorial Southern Indian Ocean

Directory of Open Access Journals (Sweden)

L. Zhang

2012-05-01

Full Text Available We examine the distribution of tropical tropospheric ozone (O₃ from the Microwave Limb Sounder (MLS and the Tropospheric Emission Spectrometer (TES by using a global three-dimensional model of tropospheric chemistry (GEOS-Chem. MLS and TES observations of tropospheric O₃ during 2005 to 2009 reveal a distinct, persistent O₃ maximum, both in mixing ratio and tropospheric column, in May over the Equatorial Southern Indian Ocean (ESIO. The maximum is most pronounced in 2006 and 2008 and less evident in the other three years. This feature is also consistent with the total column O₃ observations from the Ozone Mapping Instrument (OMI and the Atmospheric Infrared Sounder (AIRS. Model results reproduce the observed May O₃ maximum and the associated interannual variability. The origin of the maximum reflects a complex interplay of chemical and dynamic factors. The O₃ maximum is dominated by the O₃ production driven by lightning nitrogen oxides (NO_x emissions, which accounts for 62% of the tropospheric column O₃ in May 2006. We find the contribution from biomass burning, soil, anthropogenic and biogenic sources to the O₃ maximum are rather small. The O₃ productions in the lightning outflow from Central Africa and South America both peak in May and are directly responsible for the O₃ maximum over the western ESIO. The lightning outflow from Equatorial Asia dominates over the eastern ESIO. The interannual variability of the O₃ maximum is driven largely by the anomalous anti-cyclones over the southern Indian Ocean in May 2006 and 2008. The lightning outflow from Central Africa and South America is effectively entrained by the anti-cyclones followed by northward transport to the ESIO.

Solar maximum observatory

International Nuclear Information System (INIS)

Rust, D.M.

1984-01-01

The successful retrieval and repair of the Solar Maximum Mission (SMM) satellite by Shuttle astronauts in April 1984 permitted continuance of solar flare observations that began in 1980. The SMM carries a soft X ray polychromator, gamma ray, UV and hard X ray imaging spectrometers, a coronagraph/polarimeter and particle counters. The data gathered thus far indicated that electrical potentials of 25 MeV develop in flares within 2 sec of onset. X ray data show that flares are composed of compressed magnetic loops that have come too close together. Other data have been taken on mass ejection, impacts of electron beams and conduction fronts with the chromosphere and changes in the solar radiant flux due to sunspots. 13 references

Post optimization paradigm in maximum 3-satisfiability logic programming

Science.gov (United States)

Mansor, Mohd. Asyraf; Sathasivam, Saratha; Kasihmuddin, Mohd Shareduwan Mohd

2017-08-01

Maximum 3-Satisfiability (MAX-3SAT) is a counterpart of the Boolean satisfiability problem that can be treated as a constraint optimization problem. It deals with a conundrum of searching the maximum number of satisfied clauses in a particular 3-SAT formula. This paper presents the implementation of enhanced Hopfield network in hastening the Maximum 3-Satisfiability (MAX-3SAT) logic programming. Four post optimization techniques are investigated, including the Elliot symmetric activation function, Gaussian activation function, Wavelet activation function and Hyperbolic tangent activation function. The performances of these post optimization techniques in accelerating MAX-3SAT logic programming will be discussed in terms of the ratio of maximum satisfied clauses, Hamming distance and the computation time. Dev-C++ was used as the platform for training, testing and validating our proposed techniques. The results depict the Hyperbolic tangent activation function and Elliot symmetric activation function can be used in doing MAX-3SAT logic programming.

Mass mortality of the vermetid gastropod Ceraesignum maximum

Science.gov (United States)

Brown, A. L.; Frazer, T. K.; Shima, J. S.; Osenberg, C. W.

2016-09-01

Ceraesignum maximum (G.B. Sowerby I, 1825), formerly Dendropoma maximum, was subject to a sudden, massive die-off in the Society Islands, French Polynesia, in 2015. On Mo'orea, where we have detailed documentation of the die-off, these gastropods were previously found in densities up to 165 m-2. In July 2015, we surveyed shallow back reefs of Mo'orea before, during and after the die-off, documenting their swift decline. All censused populations incurred 100% mortality. Additional surveys and observations from Mo'orea, Tahiti, Bora Bora, and Huahine (but not Taha'a) suggested a similar, and approximately simultaneous, die-off. The cause(s) of this cataclysmic mass mortality are currently unknown. Given the previously documented negative effects of C. maximum on corals, we expect the die-off will have cascading effects on the reef community.

Naturally Occurring Egg Drop Syndrome Infection in Turkeys

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Z. Biđin

2007-01-01

Full Text Available A decrease in the egg quality, production, fertility and hatchability without serious clinical signs of illness was recorded in turkey fl ocks in Croatia at the beginning of 2002. It was assumed that the egg drop syndrome virus might be one of the etiological agents responsible for the abnormalities in the egg production. The systematic serological monitoring, using a haemagglutination inhibition test, showed that the antibodies to the egg drop syndrome virus existed in 94.4 and 55.1% of the sera analysed in 2002 and 2003, respectively. The haemagglutination inhibition titres ranged from 16 to 128. The sera samples were randomly collected from 11 - to 46-week-old hens from the affected fl ocks. The serological evidence of the egg drop syndrome virus infection was confirmed by detection of the presence of the virus genome in the turkey sera by the polymerase chain reaction. Vaccination of the 18- and 25-week-old turkey hens against the egg drop syndrome virus started in March 2003. After this period, the presence of antibodies to the egg drop syndrome virus (the haemagglutination inhibition titres between 16 and 256 was found in 96.7% of the analysed sera, while the egg production reached normal or higher values for the Nicholas hybrid line of turkeys.

DNA Copy-Number Control through Inhibition of Replication Fork Progression

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Jared T. Nordman

2014-11-01

Full Text Available Proper control of DNA replication is essential to ensure faithful transmission of genetic material and prevent chromosomal aberrations that can drive cancer progression and developmental disorders. DNA replication is regulated primarily at the level of initiation and is under strict cell-cycle regulation. Importantly, DNA replication is highly influenced by developmental cues. In Drosophila, specific regions of the genome are repressed for DNA replication during differentiation by the SNF2 domain-containing protein SUUR through an unknown mechanism. We demonstrate that SUUR is recruited to active replication forks and mediates the repression of DNA replication by directly inhibiting replication fork progression instead of functioning as a replication fork barrier. Mass spectrometry identification of SUUR-associated proteins identified the replicative helicase member CDC45 as a SUUR-associated protein, supporting a role for SUUR directly at replication forks. Our results reveal that control of eukaryotic DNA copy number can occur through the inhibition of replication fork progression.

A comparison of muscle activity in concentric and counter movement maximum bench press.

Science.gov (United States)

van den Tillaar, Roland; Ettema, Gertjan

2013-01-01

The purpose of this study was to compare the kinematics and muscle activation patterns of regular free-weight bench press (counter movement) with pure concentric lifts in the ascending phase of a successful one repetition maximum (1-RM) attempt in the bench press. Our aim was to evaluate if diminishing potentiation could be the cause of the sticking region. Since diminishing potentiation cannot occur in pure concentric lifts, the occurrence of a sticking region in this type of muscle actions would support the hypothesis that the sticking region is due to a poor mechanical position. Eleven male participants (age 21.9 ± 1.7 yrs, body mass 80.7 ± 10.9 kg, body height 1.79 ± 0.07 m) conducted 1-RM lifts in counter movement and in pure concentric bench presses in which kinematics and EMG activity were measured. In both conditions, a sticking region occurred. However, the start of the sticking region was different between the two bench presses. In addition, in four of six muscles, the muscle activity was higher in the counter movement bench press compared to the concentric one. Considering the findings of the muscle activity of six muscles during the maximal lifts it was concluded that the diminishing effect of force potentiation, which occurs in the counter movement bench press, in combination with a delayed muscle activation unlikely explains the existence of the sticking region in a 1-RM bench press. Most likely, the sticking region is the result of a poor mechanical force position.

Inhibition of photosynthesis in the microalga Chaetoceros curvisetus (Bacillariophyta) by macroalga Gracilaria lemaneiformis (Rhodophyta)

Science.gov (United States)

Ye, Changpeng; Zhang, Mengcheng; Yang, Yufeng

2013-11-01

We investigated the effects of dried macroalga Gracilaria lemaneiformis (Rhodophyta) on photosynthesis of the bloom-forming microalga Chaetoceros curvisetus. C. curvisetus was cultured with different amounts of dried G. lemaneiformis under controlled laboratory conditions. We measured the photosynthetic oxygen evolution rate and established the chlorophyll a fluorescence transient (OJIP) curve coupled with its specific parameters. We observed concentration-dependent and time-dependent relationships between dried G. lemaneiformis and inhibition of photosynthesis in C. curvisetus. Co-culture with dried G. lemaneiformis also resulted in a decrease in the light-saturated maximum photosynthetic oxygen evolution rate ( P max) in C. curvisetus, and a decrease in the OJIP curve along with its specific parameters; the maximum photochemical efficiency of PSII ( F v / F m), the amount of active PSII reaction centers per excited cross section at t=0 and t= t FM (RC/CS0 and RC/CSm, respectively), the absorption flux per excited cross section at t =0 (ABS/ CS0), and the efficiency with which a trapped exciton moves an electron into the electron transport chain ( ψ 0). The dark respiration rate ( R d) increased in C. curvisetus co-cultured with dried G. lemaneiformis. The JIP-test and the oxygen evolution results indicated that dried G. lemaneiformis decreased the number of active reaction centers, blocked the electron transport chain, and damaged the oxygen-evolving complex of C. curvisetus. This result indicated that dried fragments of G. lemaneiformis could effectively inhibit photosynthesis of C. curvisetus, and thus, could serve as a functional product to control and mitigate C. curvisetus blooms.

Maximum phytoplankton concentrations in the sea

DEFF Research Database (Denmark)

Jackson, G.A.; Kiørboe, Thomas

2008-01-01

A simplification of plankton dynamics using coagulation theory provides predictions of the maximum algal concentration sustainable in aquatic systems. These predictions have previously been tested successfully against results from iron fertilization experiments. We extend the test to data collect...

Inhibition of ethylene production by putrescine alleviates aluminium-induced root inhibition in wheat plants.

Science.gov (United States)

Yu, Yan; Jin, Chongwei; Sun, Chengliang; Wang, Jinghong; Ye, Yiquan; Zhou, Weiwei; Lu, Lingli; Lin, Xianyong

2016-01-08

Inhibition of root elongation is one of the most distinct symptoms of aluminium (Al) toxicity. Although putrescine (Put) has been identified as an important signaling molecule involved in Al tolerance, it is yet unknown how Put mitigates Al-induced root inhibition. Here, the possible mechanism was investigated by using two wheat genotypes differing in Al resistance: Al-tolerant Xi Aimai-1 and Al-sensitive Yangmai-5. Aluminium caused more root inhibition in Yangmai-5 and increased ethylene production at the root apices compared to Xi Aimai-1, whereas the effects were significantly reversed by ethylene biosynthesis inhibitors. The simultaneous exposure of wheat seedlings to Al and ethylene donor, ethephon, or ethylene biosynthesis precursor, 1-aminocyclopropane-1-carboxylic acid (ACC), increased ethylene production and aggravated root inhibition, which was more pronounced in Xi Aimai-1. In contrast, Put treatment decreased ethylene production and alleviated Al-induced root inhibition in both genotypes, and the effects were more conspicuous in Yangmai-5. Furthermore, our results indicated that Al-induced ethylene production was mediated by ACC synthase (ACS) and ACC oxidase, and that Put decreased ethylene production by inhibiting ACS. Altogether, these findings indicate that ethylene is involved in Al-induced root inhibition and this process could be alleviated by Put through inhibiting ACS activity.

On the Pontryagin maximum principle for systems with delays. Economic applications

Science.gov (United States)

Kim, A. V.; Kormyshev, V. M.; Kwon, O. B.; Mukhametshin, E. R.

2017-11-01

The Pontryagin maximum principle [6] is the key stone of finite-dimensional optimal control theory [1, 2, 5]. So beginning with opening the maximum principle it was important to extend the maximum principle on various classes of dynamical systems. In t he paper we consider some aspects of application of i-smooth analysis [3, 4] in the theory of the Pontryagin maximum principle [6] for systems with delays, obtained results can be applied by elaborating optimal program controls in economic models with delays.

Comparison of the Spatiotemporal Variability of Temperature, Precipitation, and Maximum Daily Spring Flows in Two Watersheds in Quebec Characterized by Different Land Use

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Ali A. Assani

2016-01-01

Full Text Available We compared the spatiotemporal variability of temperatures and precipitation with that of the magnitude and timing of maximum daily spring flows in the geographically adjacent L’Assomption River (agricultural and Matawin River (forested watersheds during the period from 1932 to 2013. With regard to spatial variability, fall, winter, and spring temperatures as well as total precipitation are higher in the agricultural watershed than in the forested one. The magnitude of maximum daily spring flows is also higher in the first watershed as compared with the second, owing to substantial runoff, given that the amount of snow that gives rise to these flows is not significantly different in the two watersheds. These flows occur early in the season in the agricultural watershed because of the relatively high temperatures. With regard to temporal variability, minimum temperatures increased over time in both watersheds. Maximum temperatures in the fall only increased in the agricultural watershed. The amount of spring rain increased over time in both watersheds, whereas total precipitation increased significantly in the agricultural watershed only. However, the amount of snow decreased in the forested watershed. The magnitude of maximum daily spring flows increased over time in the forested watershed.

Maternal Encouragement to Approach Novelty: A Curvilinear Relation to Change in Anxiety for Inhibited Toddlers.

Science.gov (United States)

Kiel, Elizabeth J; Premo, Julie E; Buss, Kristin A

2016-04-01

Various parenting behaviors (e.g., protection, intrusiveness, sensitivity) have been shown to impact young children's anxiety development, particularly for temperamentally inhibited children. These behaviors have sometimes predicted both increases and decreases in anxiety in inhibited children, suggesting that linear relations may not adequately model their influence. In the current study, we proposed the dimension of encouragement to approach novelty to characterize parenting behavior ranging from very little encouragement (i.e., protective behavior) to very strong encouragement (i.e., intrusiveness), with gentle encouragement residing in the middle. In a sample of 110 toddlers (48 female, 62 male) and their mothers, the linear and curvilinear effects of this parenting dimension were investigated in relation to change in child separation anxiety and shyness from age 2 to age 3. Inhibited temperament was also investigated as a moderator. Encouragement to approach novelty displayed the hypothesized curvilinear relation to change in separation anxiety, but not shyness, at extreme levels of inhibited temperament. Toddlers increased in separation anxiety when mothers' encouragement resided at either extreme end of the continuum, with lower child anxiety occurring when mothers displayed behavior closer to the middle of the continuum. Implications for the study of parenting outcomes for inhibited toddlers are discussed.

Development of natural cellulase inhibitor mediated intensified biological pretreatment technology using Pleurotus florida for maximum recovery of cellulose from paddy straw under solid state condition.

Science.gov (United States)

Naresh Kumar, Manickam; Ravikumar, Rajarathinam; Thenmozhi, Senniyappan; Kirupa Sankar, Muthuvelu

2017-11-01

Inhibitor mediated intensified bio-pretreatment (IMBP) technology using natural cellulase inhibitor (NCI) for maximum cellulose recovery from paddy straw was studied. Pretreatment was carried out under solid state condition. Supplementation of 8% NCI in pretreatment medium improves cellulose recovery and delignification by 1.2 and 1.5-fold respectively, compared to conventional bio-pretreatment due to inhibition of 61% of cellulase activity in IMBP. Further increase in NCI concentration showed negative effect on Pleurotus florida growth and suppress the laccase productivity by 1.1-fold. Laccase activity in IMBP was found to be 2.0U/mL on 19 th day, which is higher than (1.5U/mL) conventional bio-pretreatment. Physico-chemical modifications in paddy straw before and after pretreatment were analysed by SEM, ATR-FTIR, XRD and TGA. According to these findings, the IMBP technology can be a viable eco-friendly technology for sustainable production of bioethanol with maximum cellulose recovery. Copyright © 2017 Elsevier Ltd. All rights reserved.

An Insecticidal Compound Produced by an Insect-Pathogenic Bacterium Suppresses Host Defenses through Phenoloxidase Inhibition

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Ihsan Ullah

2014-12-01

Full Text Available A bioassay-guided column chromatographic strategy was adopted in the present study to fractionate the culture extract of Photorhabdus temperata M1021 to identify potential insecticidal and antimicrobial compounds. An ethyl acetate (EtOAc culture extract of P. temperata was assayed against Galleria mellonella larvae through intra-hemocoel injection and exhibited 100% insect mortality within 60 h. The EtOAc fraction and an isolated compound exhibited phenoloxidase (PO inhibition of up to 60% and 63%, respectively. The compound was identified as 1,2-benzenedicarboxylic acid (phthalic acid, PA by gas chromatography-mass spectrometry and nuclear magnetic resonance. PA exhibited insecticidal activity against G. mellonella in a dose-dependent manner, and 100% insect mortality was observed at 108 h after injection of 1 M PA. In a PO inhibition assay, 0.5 and 1 M concentrations of PA were found to inhibit PO activity by 74% and 82%, respectively; and in a melanotic nodule formation assay, nodule formation was significantly inhibited (27 and 10 nodules by PA (0.5 and 1 M, respectively. PA was furthermore found to have substantial antioxidant activity and maximum antioxidant activity was 64.7% for 0.5 M PA as compare to control. Antibacterial activity was assessed by The MIC values ranged from 0.1 M to 0.5 M of PA. This study reports a multifunctional PA, a potential insecticidal agent, could a factor of insect mortality along with other toxins produced by P. temperata M1021.

Inhibition of DNA repair by Pentoxifylline and related methylxanthine derivatives

International Nuclear Information System (INIS)

Boehm, Lothar; Roos, Wynand Paul; Serafin, Antonio Mendes

2003-01-01

The methylxanthine drug Pentoxifylline is reviewed for new properties which have emerged only relatively recently and for which clinical applications can be expected. After a summary on the established systemic effects of Pentoxifylline on the microcirculation and reduction of tumour anoxia, the role of the drug in the treatment of vasoocclusive disorders, cerebral ischemia, infectious diseases, septic shock and acute respiratory distress, the review focuses on another level of drug action which is based on in vitro observations in a variety of cell lines. Pentoxifylline and the related drug Caffeine are known radiosensitizers especially in p53 mutant cells. The explanation that the drug abrogates the G2 block and shortens repair in G2 by promoting early entry into mitosis is not anymore tenable because enhancement of radiotoxicity requires presence of the drug during irradiation and fails when the drug is added after irradiation at the G2 maximum. Repair assays by measurement of recovery ratios and by delayed plating experiments indeed strongly suggested a role in repair which is now confirmed for Pentoxifylline by constant field gel electrophoresis (CFGE) measurements and for Pentoxifylline and for Caffeine by use of a variety of repair mutants. The picture now emerging shows that Caffeine and Pentoxifylline inhibit homologous recombination by targeting members of the PIK kinase family (ATM and ATR) which facilitate repair in G2. Pentoxifylline induced repair inhibition between irradiation dose fractions to counter interfraction repair has been successfully applied in a model for stereotactic surgery. Another realistic avenue of application of Pentoxifylline in tumour therapy comes from experiments which show that repair events in G2 can be targeted directly by addition of cytotoxic drugs and Pentoxifylline at the G2 maximum. Under these conditions massive dose enhancement factors of up to 80 have been observed suggesting that it may be possible to realise

MECHANISM OF ACTION OF ANTIBIOTICS WHICH INHIBIT SYNTHESIS OF BACTERIAL CELL WALL

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Indira Mujezinović

2013-03-01

Full Text Available Bacterial cell possess a cell wall, which is a main difference from mammalian cells. Its basic function is to provide the strength of bacteria, keeps its shape and provides an unusually high internal osmotic pressure. Synthesis of (construction of bacterial cell wall occurs in at least three phases. All of these three phases can be influence by a variety of antibiotics in way to inhibit its synthesis. The most important drugs that act in this manner are ß-lactam antibiotics (penicillins, cephalosporins, cephamycins and other ß-lactams. They interfere with the synthesis of the bacterial cell wall peptidoglycan. After attachment to penicillin binding proteins (PBP on bacteria, they inhibit the transpeptidation enzyme that cross-links the peptide chain attached to the backbone of the peptidoglycan. The final bactericidal event is the inactivation of an inhibitor of autolytic enzymes in the cell wall, wich leads to lysis of the bacteria. Vancomycin inhibits the release of the building block unit from the carrier, thus preventing its addition to the growing end of the peptidoglycan. Cycloserine, which is a structural analogue of D-alanine, prevents the addition of the two terminal alanine residue to the initial tripeptide side-chain on N-acetylmuramic acid by competitive inhibition. Bacitracin interferes with the regeneration of the lipid carrier by blocking its dephosphorylation. Key words: bacterial cell wall, paptidoglycan, antibiotics, ß-lactams

Autoinflammatory Reaction in Dogs Treated for Cancer via G6PD Inhibition

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Jonathan W. Nyce

2017-01-01

Full Text Available Glucose-6-phosphate dehydrogenase (G6PD is an oncoprotein that is overexpressed in cancer cells to provide the NADPH required for their increased anabolism. NADPH, sourced from G6PD fuels nucleotide biosynthesis, maintains redox potential of thioredoxin and glutathione and drives the mevalonate pathway that powers many of the basic mechanisms by which cancer cells escape host control. G6PD is thus a target for cancer treatment being addressed by many groups around the world. We have discovered that systemic inhibition of G6PD by high dose dehydroepiandrosterone (DHEA causes a severe autoinflammatory response in dogs, which does not occur in mice or rats. Since dogs more closely model the human adrenal androgen system than do common laboratory animals, this finding is relevant to the design of G6PD-inhibiting drugs for humans. The autoinflammatory reaction observed closely resembles mevalonate kinase deficiency (MKD, a rare autosomal recessive disease in humans characterized by recurrent febrile attacks, arthralgia, skin rash, and aphthous ulcers of mucocutaneous tissues. In a manner comparable to animal models of MKD, the reconstitution of protein geranylgeranylation blocked the autoinflammatory reaction caused by systemic G6PD inhibition. This autoinflammatory response to systemic G6PD inhibition represents an unexpected result that must be taken into consideration when targeting this oncoprotein.

Coronary ligation reduces maximum sustained swimming speed in Chinook salmon, Oncorhynchus tshawytscha

DEFF Research Database (Denmark)

Farrell, A P; Steffensen, J F

1987-01-01

The maximum aerobic swimming speed of Chinook salmon (Oncorhynchus tshawytscha) was measured before and after ligation of the coronary artery. Coronary artery ligation prevented blood flow to the compact layer of the ventricular myocardium, which represents 30% of the ventricular mass, and produced...... a statistically significant 35.5% reduction in maximum swimming speed. We conclude that the coronary circulation is important for maximum aerobic swimming and implicit in this conclusion is that maximum cardiac performance is probably necessary for maximum aerobic swimming performance....

A mathematical model of the maximum power density attainable in an alkaline hydrogen/oxygen fuel cell

Science.gov (United States)

Kimble, Michael C.; White, Ralph E.

1991-01-01

A mathematical model of a hydrogen/oxygen alkaline fuel cell is presented that can be used to predict the polarization behavior under various power loads. The major limitations to achieving high power densities are indicated and methods to increase the maximum attainable power density are suggested. The alkaline fuel cell model describes the phenomena occurring in the solid, liquid, and gaseous phases of the anode, separator, and cathode regions based on porous electrode theory applied to three phases. Fundamental equations of chemical engineering that describe conservation of mass and charge, species transport, and kinetic phenomena are used to develop the model by treating all phases as a homogeneous continuum.

AVS-1357 inhibits melanogenesis via prolonged ERK activation.

Science.gov (United States)

Kim, Dong-Seok; Lee, Hyun-Kyung; Park, Seo-Hyoung; Chae, Chong Hak; Park, Kyoung-Chan

2009-08-01

In this study, we demonstrated that a derivative of imidazole, AVS-1357, is a novel skin-whitening compound. AVS-1357 was found to significantly inhibit melanin production in a dose-dependent manner; however, it did not directly inhibit tyrosinase. Furthermore, we found that AVS-1357 induced prolonged activation of extracellular signal-regulated kinase (ERK) and Akt, while it downregulated microphthalmia-associated transcription factor (MITF) and tyrosinase. It has been reported that the activation of ERK and/or Akt is involved in melanogenesis. Therefore, we examined the effects of AVS-1357 on melanogenesis in the absence or presence of PD98059 (a specific inhibitor of the ERK pathway) and/or LY294002 (a specific inhibitor of the Akt pathway). PD98059 dramatically increased melanogenesis, whereas LY294002 had no effect. Furthermore, PD98059 attenuated AVS-1357 induced ERK activation, as well as the downregulation of MITF and tyrosinase. These findings suggest that the effects of AVS-1357 occur via downregulation of MITF and tyrosinase, which is caused by AVS-1357-induced prolonged ERK activation. Taken together, our results indicate that AVS-1357 has the potential as a new skin whitening agent.

Liver δ-Aminolevulinate Dehydratase Activity is Inhibited by Neonicotinoids and Restored by Antioxidant Agents

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Elisa Sauer

2014-11-01

Full Text Available Neonicotinoids represent the most used class of insecticides worldwide, and their precursor, imidacloprid, is the most widely marketed. The aim of this study was to evaluate the effect of imidacloprid on the activity of hepatic δ-aminolevulinate dehydratase (δ-ALA-D, protective effect of potential antioxidants against this potential effect and presence of chemical elements in the constitution of this pesticide. We observed that δ-ALA-D activity was significantly inhibited by imidacloprid at all concentrations tested in a dose-dependent manner. The IC50 value was obtained and used to evaluate the restoration of the enzymatic activity. δ-ALA-D inhibition was completely restored by addition of dithiotreitol (DTT and partly by ZnCl2, demonstrating that the inhibition occurs by oxidation of thiol groups and by displacement of the Zn (II, which can be explained by the presence of chemical elements found in the constitution of pesticides. Reduced glutathione (GSH had the best antioxidant effect against to δ-ALA-D inhibition caused by imidacloprid, followed by curcumin and resveratrol. It is well known that inhibition of the enzyme δ-ALA-D may result in accumulation of its neurotoxic substrate (δ-ALA, in this line, our results suggest that further studies are needed to investigate the possible neurotoxicity induced by neonicotinoids and the involvement of antioxidants in cases of poisoning by neonicotinoids.

Genistein inhibited ammonia induced astrocyte swelling by inhibiting NF-κB activation-mediated nitric oxide formation.

Science.gov (United States)

Dai, Hongliang; Jia, Guizhi; Wang, Wei; Liang, Chunguang; Han, Siyu; Chu, Minghui; Mei, Xifan

2017-06-01

Our previous study has indicated the involvement of epidermal growth factor receptor (EGFR) transactivation in ammonia-induced astrocyte swelling, which represents a major pathogenesis of brain edema in hepatic encephalopathy. In this study, we examined the effect of genistein, a naturally occurred broad-spectrum protein tyrosine kinase (PTK) inhibitor, on ammonia-induced cell swelling. We found that genistein pretreatment significantly prevented ammonia-induced astrocyte swelling. Mechanistically, ammonia triggered EGFR/extracellular signal-regulated kinase (ERK) association and subsequent ERK phosphorylation were alleviated by genistein pretreatment. Moreover, ammonia-induced NF-κB nuclear location, iNOS expression, and consequent NO production were all prevented by AG1478 and genistein pretreatment. This study suggested that genistein could alleviate ammonia-induced astrocyte swelling, which may be, at least partly, related to its PTK-inhibiting activity and repression of NF-κB mediated iNOS-derived NO accumulation.

Allicin from garlic inhibits the biofilm formation and urease activity of Proteus mirabilis in vitro.

Science.gov (United States)

Ranjbar-Omid, Mahsa; Arzanlou, Mohsen; Amani, Mojtaba; Shokri Al-Hashem, Seyyedeh Khadijeh; Amir Mozafari, Nour; Peeri Doghaheh, Hadi

2015-05-01

Several virulence factors contribute to the pathogenesis of Proteus mirabilis. This study determined the inhibitory effects of allicin on urease, hemolysin and biofilm of P. mirabilis ATCC 12453 and its antimicrobial activity against 20 clinical isolates of P. mirabilis. Allicin did not inhibit hemolysin, whereas it did inhibit relative urease activity in both pre-lysed (half-maximum inhibitory concentration, IC50 = 4.15 μg) and intact cells (IC50 = 21 μg) in a concentration-dependent manner. Allicin at sub-minimum inhibitory concentrations (2-32 μg mL(-1)) showed no significant effects on the growth of the bacteria (P > 0.05), but it reduced biofilm development in a concentration-dependent manner (P mirabilis isolates were determined to be 128 and 512 μg mL(-1), respectively. The results suggest that allicin could have clinical applications in controlling P. mirabilis infections. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The aryl hydrocarbon receptor ligand ITE inhibits TGFβ1-induced human myofibroblast differentiation.

Science.gov (United States)

Lehmann, Geniece M; Xi, Xia; Kulkarni, Ajit A; Olsen, Keith C; Pollock, Stephen J; Baglole, Carolyn J; Gupta, Shikha; Casey, Ann E; Huxlin, Krystel R; Sime, Patricia J; Feldon, Steven E; Phipps, Richard P

2011-04-01

Fibrosis can occur in any human tissue when the normal wound healing response is amplified. Such amplification results in fibroblast proliferation, myofibroblast differentiation, and excessive extracellular matrix deposition. Occurrence of these sequelae in organs such as the eye or lung can result in severe consequences to health. Unfortunately, medical treatment of fibrosis is limited by a lack of safe and effective therapies. These therapies may be developed by identifying agents that inhibit critical steps in fibrotic progression; one such step is myofibroblast differentiation triggered by transforming growth factor-β1 (TGFβ1). In this study, we demonstrate that TGFβ1-induced myofibroblast differentiation is blocked in human fibroblasts by a candidate endogenous aryl hydrocarbon receptor (AhR) ligand 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE). Our data show that ITE disrupts TGFβ1 signaling by inhibiting the nuclear translocation of Smad2/3/4. Although ITE functions as an AhR agonist, and biologically persistent AhR agonists, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin, cause severe toxic effects, ITE exhibits no toxicity. Interestingly, ITE effectively inhibits TGFβ1-driven myofibroblast differentiation in AhR(-/-) fibroblasts: Its ability to inhibit TGFβ1 signaling is AhR independent. As supported by the results of this study, the small molecule ITE inhibits myofibroblast differentiation and may be useful clinically as an antiscarring agent. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Translational step inhibited in vivo by aflatoxin B1 in rat-liver polysomes

International Nuclear Information System (INIS)

Sarasin, A.; Moule, Y.

1975-01-01

Aflatoxin B 1 strongly inhibits protein synthesis in rat liver cells. This paper confirms the foregoing results and represents an attempt to localize the translational step inhibited in vivo by aflatoxin B 1 . We used the simulation study developed by Li, Kisilevsky, Wasan and Hammond, 1972 (Biochim. Biophys. Acta, 272, 451-462) to determine precisely the site inhibited in vivo after drug intoxication. This analysis is based on two parameters: the kinetics of polysome labeling to follow the nascent peptide synthesis, and the kinetics of supernatant labeling to follow the completed protein synthesis. Up to 5 h after dosing, aflatoxin specifically inhibits the elongation and/or termination steps during protein synthesis; after longer periods of time inhibition occurs essentially at the initiation step. When the intracellular concentration of aflatoxin is too high, particularly 2 h after dosing, each step of protein synthesis is blocked. Polypeptide synthesis by the postmitochondrial supernatants isolated from aflatoxin-treated animals is impaired in the same proportion as protein synthesis in vivo. The damage caused by aflatoxin is mostly observed on microsomes. However, purified polysomes isolated from aflatoxin-treated rats synthesize proteins in vitro to the same extent as those from controls. These results suggest that aflatoxin metabolite(s) are bound to polysomes with noncovalent bonds. These active metabolites are probably lost during polysome isolation procedures. Finally, relationships between protein metabolism and aflatoxin carcinogenesis are discussed. (orig./BSC) [de

Thalamocortical NMDA conductances and intracortical inhibition can explain cortical temporal tuning

Science.gov (United States)

Krukowski, A. E.; Miller, K. D.

2001-01-01

Cells in cerebral cortex fail to respond to fast-moving stimuli that evoke strong responses in the thalamic nuclei innervating the cortex. The reason for this behavior has remained a mystery. We study an experimentally motivated model of the thalamic input-recipient layer of cat primary visual cortex that accounts for many aspects of cortical orientation tuning. In this circuit, inhibition dominates over excitation, but temporal modulations of excitation and inhibition occur out of phase with one another, allowing excitation to transiently drive cells. We show that this circuit provides a natural explanation of cortical low-pass temporal frequency tuning, provided N-methyl-D-aspartate (NMDA) receptors are present in thalamocortical synapses in proportions measured experimentally. This suggests a new and unanticipated role for NMDA conductances in shaping the temporal response properties of cortical cells, and suggests that common cortical circuit mechanisms underlie both spatial and temporal response tuning.

Fogging on T2-weighted MR after acute ischaemic stroke: how often might this occur and what are the implications?

International Nuclear Information System (INIS)

O'Brien, P.; Sellar, R.J.; Wardlaw, J.M.

2004-01-01

''Fogging'' is the temporary loss of visibility of an infarct on CT which occurs in the subacute phase at about 2 weeks after stroke. It occurs in up to 40% of medium to large infarcts on CT. It is unclear whether or how often fogging occurs on T2-weighted MR, but if it does occur, it can cause underestimation of true infarct size. This study examined the possible frequency and time scale of ''fogging'' on T2-weighted MR. We conducted a blinded, independent review of prospectively collected MR scans from patients with symptoms of cortical ischaemic stroke, scanned sequentially up to 7 weeks after stroke. On each scan maximum infarct area was measured, and the infarct extent and swelling were coded on a validated scale. ''Fogging'' was suggested by reduced infarct extent between initial and subsequent scans. In 30 patients (with 74 scans) there was some apparent ''fogging'' in 50% of patients between 6 and 36 days (median 10 days) after stroke. Reduction in infarct extent on T2-weighted MR which may be attributed to ''fogging'' occurs in a significant proportion of patients with cortical infarcts. This may lead to an underestimation of true final infarct extent. This suggests that true infarct extent on T2-weighted MR can probably only be assessed on scans obtained beyond 7 weeks after stroke. (orig.)

Effects of bruxism on the maximum bite force

Directory of Open Access Journals (Sweden)

Todić Jelena T.

2017-01-01

Full Text Available Background/Aim. Bruxism is a parafunctional activity of the masticatory system, which is characterized by clenching or grinding of teeth. The purpose of this study was to determine whether the presence of bruxism has impact on maximum bite force, with particular reference to the potential impact of gender on bite force values. Methods. This study included two groups of subjects: without and with bruxism. The presence of bruxism in the subjects was registered using a specific clinical questionnaire on bruxism and physical examination. The subjects from both groups were submitted to the procedure of measuring the maximum bite pressure and occlusal contact area using a single-sheet pressure-sensitive films (Fuji Prescale MS and HS Film. Maximal bite force was obtained by multiplying maximal bite pressure and occlusal contact area values. Results. The average values of maximal bite force were significantly higher in the subjects with bruxism compared to those without bruxism (p 0.01. Maximal bite force was significantly higher in the males compared to the females in all segments of the research. Conclusion. The presence of bruxism influences the increase in the maximum bite force as shown in this study. Gender is a significant determinant of bite force. Registration of maximum bite force can be used in diagnosing and analysing pathophysiological events during bruxism.

Behavioral inhibition and obsessive-compulsive disorder.

Science.gov (United States)

Coles, Meredith E; Schofield, Casey A; Pietrefesa, Ashley S

2006-01-01

Behavioral inhibition is frequently cited as a vulnerability factor for development of anxiety. However, few studies have examined the unique relationship between behavioral inhibition and obsessive-compulsive disorder (OCD). Therefore, the current study addressed the relationship between behavioral inhibition and OCD in a number of ways. In a large unselected student sample, frequency of current OC symptoms was significantly correlated with retrospective self-reports of total levels of childhood behavioral inhibition. In addition, frequency of current OC symptoms was also significantly correlated with both social and nonsocial components of behavioral inhibition. Further, there was evidence for a unique relationship between behavioral inhibition and OC symptoms beyond the relationship of behavioral inhibition and social anxiety. In addition, results showed that reports of childhood levels of behavioral inhibition significantly predicted levels of OCD symptoms in adulthood. Finally, preliminary evidence suggested that behavioral inhibition may be more strongly associated with some types of OC symptoms than others, and that overprotective parenting may moderate the impact of behavioral inhibition on OC symptoms. The current findings suggest the utility of additional research examining the role of behavioral inhibition in the etiology of OCD.

Relative contributions of pituitary-adrenal hormones to the ontogeny of behavioral inhibition in the rat.

Science.gov (United States)

Takahashi, L K; Kim, H

1995-04-01

Recent investigations revealed that adrenalectomized (ADX) rat pups exhibit deficits in behavioral inhibition. Furthermore, administration of exogenous corticosterone (CORT) restores behavioral inhibition in ADX pups. Although these studies suggest that CORT has an important role in the development of behavioral inhibition, the relative behavioral effects of elevated pituitary hormone secretion induced by ADX are not known. Therefore, experiments were conducted to assess the potential behavioral effects of elevated adrenocorticotropin (ACTH) secretion induced by ADX and to further evaluate the contribution of endogenous CORT to the development of behavioral inhibition. In Experiment 1., we verified that 10-day-old ADX rats exhibit high levels of plasma ACTH throughout the preweaning period associated with the development of behavioral inhibition. In Experiment 2, 10-day-old pups were hypophysectomized (HYPOX) and ADX and were compared behaviorally to sham-operated controls on day 14. When tested in the presence of an anesthetized unfamiliar adult male rat, HYPOX + ADX pups exhibited low levels of freezing accompanied by ultrasonic vocalizations. These pups also had reduced concentrations of plasma ACTH and CORT. In Experiment 3, 10-day-old pups were HYPOX and tested for behavioral inhibition on day 14. In comparison to sham-operated controls, HYPOX rats exhibited significantly lower levels of freezing and had reduced plasma concentrations of ACTH and CORT. Results demonstrate clearly that deficits in freezing occur even in the presence of low plasma ACTH concentrations. Therefore, elevated secretion of pituitary hormones is not a major factor that contributes to the ADX-induced deficits in behavioral inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)

Parameters determining maximum wind velocity in a tropical cyclone

International Nuclear Information System (INIS)

Choudhury, A.M.

1984-09-01

The spiral structure of a tropical cyclone was earlier explained by a tangential velocity distribution which varies inversely as the distance from the cyclone centre outside the circle of maximum wind speed. The case has been extended in the present paper by adding a radial velocity. It has been found that a suitable combination of radial and tangential velocities can account for the spiral structure of a cyclone. This enables parametrization of the cyclone. Finally a formula has been derived relating maximum velocity in a tropical cyclone with angular momentum, radius of maximum wind speed and the spiral angle. The shapes of the spirals have been computed for various spiral angles. (author)

RELIABILITY OF THE ONE REPETITION-MAXIMUM POWER CLEAN TEST IN ADOLESCENT ATHLETES

Science.gov (United States)

Faigenbaum, Avery D.; McFarland, James E.; Herman, Robert; Naclerio, Fernando; Ratamess, Nicholas A.; Kang, Jie; Myer, Gregory D.

2013-01-01

Although the power clean test is routinely used to assess strength and power performance in adult athletes, the reliability of this measure in younger populations has not been examined. Therefore, the purpose of this study was to determine the reliability of the one repetition maximum (1 RM) power clean in adolescent athletes. Thirty-six male athletes (age 15.9 ± 1.1 yrs, body mass 79.1 ± 20.3 kg, height 175.1 ±7.4 cm) who had more than 1 year of training experience with weightlifting exercises performed a 1 RM power clean on two nonconsecutive days in the afternoon following standardized procedures. All test procedures were supervised by a senior level weightlifting coach and consisted of a systematic progression in test load until the maximum resistance that could be lifted for one repetition using proper exercise technique was determined. Data were analyzed using an intraclass correlation coefficient (ICC [2,k]), Pearson correlation coefficient (r), repeated measures ANOVA, Bland-Altman plot, and typical error analyses. Analysis of the data revealed that the test measures were highly reliable demonstrating a test-retest ICC of 0.98 (95% CI = 0.96–0.99). Testing also demonstrated a strong relationship between 1 RM measures on trial 1 and trial 2 (r=0.98, pinjuries occurred during the study period and the testing protocol was well-tolerated by all subjects. These findings indicate that 1 RM power clean testing has a high degree of reproducibility in trained male adolescent athletes when standardized testing procedures are followed and qualified instruction is present. PMID:22233786

An event- and network-level analysis of college students' maximum drinking day.

Science.gov (United States)

Meisel, Matthew K; DiBello, Angelo M; Balestrieri, Sara G; Ott, Miles Q; DiGuiseppi, Graham T; Clark, Melissa A; Barnett, Nancy P

2018-04-01

Heavy episodic drinking is common among college students and remains a serious public health issue. Previous event-level research among college students has examined behaviors and individual-level characteristics that drive consumption and related consequences but often ignores the social network of people with whom these heavy drinking episodes occur. The main aim of the current study was to investigate the network of social connections between drinkers on their heaviest drinking occasions. Sociocentric network methods were used to collect information from individuals in the first-year class (N=1342) at one university. Past-month drinkers (N=972) reported on the characteristics of their heaviest drinking occasion in the past month and indicated who else among their network connections was present during this occasion. Average max drinking day indegree, or the total number of times a participant was nominated as being present on another students' heaviest drinking occasion, was 2.50 (SD=2.05). Network autocorrelation models indicated that max drinking day indegree (e.g., popularity on heaviest drinking occassions) and peers' number of drinks on their own maximum drinking occasions were significantly associated with participant maximum number of drinks, after controlling for demographic variables, pregaming, and global network indegree (e.g., popularity in the entire first-year class). Being present at other peers' heaviest drinking occasions is associated with greater drinking quantities on one's own heaviest drinking occasion. These findings suggest the potential for interventions that target peer influences within close social networks of drinkers. Copyright © 2017 Elsevier Ltd. All rights reserved.

Exercise-induced maximum metabolic rate scaled to body mass by ...

African Journals Online (AJOL)

Exercise-induced maximum metabolic rate scaled to body mass by the fractal ... rate scaling is that exercise-induced maximum aerobic metabolic rate (MMR) is ... muscle stress limitation, and maximized oxygen delivery and metabolic rates.

Electron density distribution in Si and Ge using multipole, maximum ...

Indian Academy of Sciences (India)

Si and Ge has been studied using multipole, maximum entropy method (MEM) and ... and electron density distribution using the currently available versatile ..... data should be subjected to maximum possible utility for the characterization of.

Naturally occurring radionuclides in food

International Nuclear Information System (INIS)

Djujic, I.

1995-01-01

The naturally occurring radionuclides are the major source of radiation exposure to humans. The principal way of natural radiation exposure is the inhalation of 222 Rn decay products (about 85% of the total). The remainder is equally divided between internally deposited radionuclides, cosmic and terrestrial sources. In the present study, the content of 40 K, 210 Pb, 226 Ra, 230 Th, 232 Th and 238 U in representative food samples (milk, pork, beef, potatoes, wheat and corn flour) and samples of different food items that do not represent entire national production but provide interesting additional data for approximative calculation of naturally occurring radionuclide intake is presented. Daily weight of food eaten, participation of food groups, as well as daily intake by food of mentioned naturally occurring radionuclides in the Serbian diet was obtained on the base of house hold budget surveys. The result obtained for daily intake estimates in mBq for Serbian population are 78.1 ( 40 K), 38.2( 210 Pb), 52.3( 226 Ra), 2.0( 230 Th) and 12.5( 238 U). (author)

Enhanced anaerobic treatment of CSTR-digested effluent from chicken manure: The effect of ammonia inhibition.

Science.gov (United States)

Liu, Zhan-Guang; Zhou, Xue-Fei; Zhang, Ya-Lei; Zhu, Hong-Guang

2012-01-01

The effect of ammonia inhibition was evaluated during the enhanced anaerobic treatment of digested effluent from a 700m(3) chicken-manure continuous stirred tank reactor (CSTR). A 12.3L internal circulation (IC) reactor inoculated with an anaerobic granular sludge and operated at 35±1°C was employed for the investigation. With a corresponding organic loading rate of 1.5-3.5kg-COD/m(3)d over a hydraulic retention time of 1.5d, a maximum volumetric biogas production rate of 1.2m(3)/m(3)d and TCOD (total COD) removal efficiency ranging from 70% to 80% was achieved. However, the continual increase in the influent TAN content led to ammonia inhibition in the methanogenesis system. The SCOD/TAN (soluble COD/total ammonia nitrogen) ratio was presented to be the key controlling factor for the anaerobic treatment of semi-digested chicken manure, and further validation through shock loading and ammonia inhibition experiments was conducted. The threshold value of the SCOD/TAN ratio was determined to be 2.4 (corresponding to a TAN of 1250mg/L) at an influent pH of 8.5-9. Copyright © 2011 Elsevier Ltd. All rights reserved.

NifI inhibits nitrogenase by competing with Fe protein for binding to the MoFe protein

International Nuclear Information System (INIS)

Dodsworth, Jeremy A.; Leigh, John A.

2007-01-01

Reduction of substrate by nitrogenase requires direct electron transfer from the Fe protein to the MoFe protein. Inhibition of nitrogenase activity in Methanococcus maripaludis occurs when the regulatory protein NifI 1,2 binds the MoFe protein. This inhibition is relieved by 2-oxoglutarate. Here we present evidence that NifI 1,2 binding prevents association of the two nitrogenase components. Increasing amounts of Fe protein competed with NifI 1,2 , decreasing its inhibitory effect. NifI 1,2 prevented the co-purification of MoFe protein with a mutant form of the Fe protein that forms a stable complex with the MoFe protein, and NifI 1,2 was unable to bind to an AlF 4 - -stabilized Fe protein:MoFe protein complex. NifI 1,2 inhibited ATP- and MoFe protein-dependent oxidation of the Fe protein, and 2OG relieved this inhibition. These results support a model where NifI 1,2 competes with the Fe protein for binding to MoFe protein and prevents electron transfer

The maximum-entropy method in superspace

Czech Academy of Sciences Publication Activity Database

van Smaalen, S.; Palatinus, Lukáš; Schneider, M.

2003-01-01

Roč. 59, - (2003), s. 459-469 ISSN 0108-7673 Grant - others:DFG(DE) XX Institutional research plan: CEZ:AV0Z1010914 Keywords : maximum-entropy method, * aperiodic crystals * electron density Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.558, year: 2003

Maximum-entropy clustering algorithm and its global convergence analysis

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

Constructing a batch of differentiable entropy functions touniformly approximate an objective function by means of the maximum-entropy principle, a new clustering algorithm, called maximum-entropy clustering algorithm, is proposed based on optimization theory. This algorithm is a soft generalization of the hard C-means algorithm and possesses global convergence. Its relations with other clustering algorithms are discussed.

Modulation of long-latency afferent inhibition by the amplitude of sensory afferent volley.

Science.gov (United States)

Turco, Claudia V; El-Sayes, Jenin; Fassett, Hunter J; Chen, Robert; Nelson, Aimee J

2017-07-01

Long-latency afferent inhibition (LAI) is the inhibition of the transcranial magnetic stimulation (TMS) motor-evoked potentials (MEP) by the sensory afferent volley following electrical stimulation of a peripheral nerve. It is unknown how the activation of sensory afferent fibers relates to the magnitude of LAI. This study investigated the relationship between LAI and the sensory nerve action potentials (SNAP) from the median nerve (MN) and the digital nerves (DN) of the second digit. LAI was obtained by delivering nerve stimulation 200 ms before a TMS pulse delivered over the motor cortex. Experiment 1 assessed the magnitude of LAI following stimulation of the contralateral MN or DN using nerve stimulus intensities relative to the maximum SNAP (SNAP max ) of that nerve and two TMS intensities (0.5- and 1-mV MEP). Results indicate that MN LAI is maximal at ~50% SNAP max , when presumably all sensory afferents are recruited for TMS of 0.5-mV MEP. For DN, LAI appears at ~50% SNAP max and does not increase with further recruitment of sensory afferents. Experiment 2 investigated the magnitude of LAI following ipsilateral nerve stimulation at intensities relative to SNAP max Results show minimal LAI evoked by ipsilateral MN and no LAI following ipsilateral DN stimulation. Implications for future studies investigating LAI include adjusting nerve stimulation to 50% SNAP max to obtain maximal LAI. Additionally, MN LAI can be used as a marker for neurological disease or injury by using a nerve stimulation intensity that can evoke a depth of LAI capable of increasing or decreasing. NEW & NOTEWORTHY This is the first investigation of the relationship between long-latency afferent inhibition (LAI) and the sensory afferent volley. Differences exist between median and digital nerve LAI. For the median nerve, LAI increases until all sensory fibers are presumably recruited. In contrast, digital nerve LAI does not increase with the recruitment of additional sensory fibers but

GSK-3β Inhibition Attenuates CLP-Induced Liver Injury by Reducing Inflammation and Hepatic Cell Apoptosis

Directory of Open Access Journals (Sweden)

Hui Zhang

2014-01-01

Full Text Available Liver dysfunction has been known to occur frequently in cases of sepsis. Excessive inflammation and apoptosis are pathological features of acute liver failure. Recent studies suggest that activation of glycogen synthase kinase- (GSK- 3β is involved in inflammation and apoptosis. We aimed to investigate the protective effects of GSK-3β inhibition on polymicrobial sepsis-induced liver injury and to explore the possible mechanisms. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP, and SB216763 was used to inhibit GSK-3β in C57BL/6 mice. GSK-3β was activated following CLP. Administration of SB216763 decreased mortality, ameliorated liver injury, and reduced hepatic apoptosis. The inhibition of GSK-3β also reduced leukocyte infiltration and hepatic inflammatory cytokine expression and release. Moreover, GSK-3β inhibition suppressed the transcriptional activity of nuclear factor-kappa B (NF-κB but enhanced the transcriptional activity of cAMP response element binding protein (CREB in the liver. In in vitro studies, GSK-3β inhibition reduced inflammatory cytokine production via modulation of NF-κB and CREB signaling pathways in lipopolysaccharide-stimulated macrophages. In conclusion, these findings suggest that GSK-3β blockade protects against CLP-induced liver via inhibition of inflammation by modulating NF-κB and CREB activity and suppression of hepatic apoptosis.

Inhibition of protein kinase C induces differentiation in Neuro-2a cells

International Nuclear Information System (INIS)

Minana, M.D.; Felipo, V.; Grisolia, S.

1990-01-01

1-(5-Isoquinolinylsulfonyl)-2-methylpiperazine (H7), a potent inhibitor of protein kinase C, induced neuritogenesis in Neuro-2a cells, whereas N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA 1004), which inhibits more efficiently cAMP- and cGMP-dependent protein kinases, did not. The effect, noticeable after 3 hr, was maximum (13-fold increase at 500 μM H7) between 1 and 3 days and was maintained over 2 months. In controls, 90% of the cells were undifferentiated, whereas after 3 hr with 500 μM H7 only 25% of the cells remained undifferentiated. DNA synthesis decreased as the number of differentiated cells increased. Differentiation is also functional since acetylcholinesterase activity increased ∼7-fold after 48 hr with 500 μM H7. Phorbol 12-myristate 13-acetate, a specific activator of protein kinase C, prevented or reversed the induction of neuritogenesis and the inhibition of DNA synthesis by H7. There is a good correlation between the level of protein kinase C and the percentage of differentiated cells. The results indicate that protein kinase C may play a key role in the control of differentiation of neural cells. Some possible clinical implications are briefly discussed

maximum neutron flux at thermal nuclear reactors

International Nuclear Information System (INIS)

Strugar, P.

1968-10-01

Since actual research reactors are technically complicated and expensive facilities it is important to achieve savings by appropriate reactor lattice configurations. There is a number of papers, and practical examples of reactors with central reflector, dealing with spatial distribution of fuel elements which would result in higher neutron flux. Common disadvantage of all the solutions is that the choice of best solution is done starting from the anticipated spatial distributions of fuel elements. The weakness of these approaches is lack of defined optimization criteria. Direct approach is defined as follows: determine the spatial distribution of fuel concentration starting from the condition of maximum neutron flux by fulfilling the thermal constraints. Thus the problem of determining the maximum neutron flux is solving a variational problem which is beyond the possibilities of classical variational calculation. This variational problem has been successfully solved by applying the maximum principle of Pontrjagin. Optimum distribution of fuel concentration was obtained in explicit analytical form. Thus, spatial distribution of the neutron flux and critical dimensions of quite complex reactor system are calculated in a relatively simple way. In addition to the fact that the results are innovative this approach is interesting because of the optimization procedure itself [sr

Antiviral activity of human lactoferrin: inhibition of alphavirus interaction with heparan sulfate

International Nuclear Information System (INIS)

Waarts, Barry-Lee; Aneke, Onwuchekwa J.C.; Smit, Jolanda M.; Kimata, Koji; Bittman, Robert; Meijer, Dirk K.F.; Wilschut, Jan

2005-01-01

Human lactoferrin is a component of the non-specific immune system with distinct antiviral properties. We used alphaviruses, adapted to interaction with heparan sulfate (HS), as a tool to investigate the mechanism of lactoferrin's antiviral activity. Lactoferrin inhibited infection of BHK-21 cells by HS-adapted, but not by non-adapted, Sindbis virus (SIN) or Semliki Forest virus (SFV). Lactoferrin also inhibited binding of radiolabeled HS-adapted viruses to BHK-21 cells or liposomes containing lipid-conjugated heparin as a receptor analog. On the other hand, low-pH-induced fusion of the viruses with liposomes, which occurs independently of virus-receptor interaction, was unaffected. Studies involving preincubation of virus or cells with lactoferrin suggested that the protein does not bind to the virus, but rather blocks HS-moieties on the cell surface. Charge-modified human serum albumin, with a net positive charge, had a similar antiviral effect against HS-adapted SIN and SFV, suggesting that the antiviral activity of lactoferrin is related to its positive charge. It is concluded that human lactoferrin inhibits viral infection by interfering with virus-receptor interaction rather than by affecting subsequent steps in the viral cell entry or replication processes

STAT6 Mediates Interleukin-4 Growth Inhibition in Human Breast Cancer Cells

Directory of Open Access Journals (Sweden)

Jennifer L. Gooch

2002-01-01

Full Text Available In addition to acting as a hematopoietic growth factor, interleukin-4 (IL-4 inhibits growth of some transformed cells in vitro and in vivo. In this study, we show that insulin receptor substrate (IRS-1, IRS-2, and signal transducer and activator of transcription 6 (STAT6 are phosphorylated following IL-4 treatment in MCF-7 breast cancer cells. STAT6 DNA binding is enhanced by IL-4 treatment. STAT6 activation occurs even after IRS-1 depletion, suggesting the two pathways are independent. To examine the role of STAT6 in IL-4-mediated growth inhibition and apoptosis, a fulllength STAT6 cDNA was transfected into MCF-7 cells. Transient overexpression of STAT6 resulted in both cytoplasmic and nuclear expression of the protein, increased DNA binding in response to IL-4, and increased transactivation of an IL-4 responsive promoter. In STAT6-transfected cells, basal proliferation was reduced whereas apoptosis was increased. Finally, stable expression of STAT6 resulted in reduced foci formation compared to vector-transfected cells alone. These results suggest STAT6 is required for IL-4mediated growth inhibition and induction of apoptosis in human breast cancer cells.

Monoamine oxidase B (MAO-B) inhibition by active principles from Uncaria rhynchophylla.

Science.gov (United States)

Hou, Wen-Chi; Lin, Rong-Dih; Chen, Cheng-Tang; Lee, Mei-Hsien

2005-08-22

Attenuation of monoamine oxidase B (MAO-B) activity may provide protection against oxidative neurodegeneration. For this reason, inhibition of MAO-B activity is used as part of the treatment of Parkinson's and Alzheimer's patients. The hook of Uncaria rhynchophylla (Miq.) Jacks. (Rubiaceae) is a traditional Chinese herbal drug that is generally used to treat convulsive disorders. In this study, the fractionation and purification of Uncaria rhynchophylla extracts using a bioguided assay isolated two known compounds, (+)-catechin and (-)-epicatechin. The compounds inhibited MAO-B, as measured by an assay of rat brain MAO-B separated by electrophoresis on a 7.5% native polyacrylamide gel. The IC(50) values of (+)-catechin and (-)-epicatechin were 88.6 and 58.9 microM, respectively, and inhibition occurred in a dose-dependent manner, as measured by the fluorescence method. The Lineweaver-Burk plot revealed K(i) values for (+)-catechin and (-)-epicatechin of 74 and 21 microM, respectively. This suggests that these two compounds, isolated here for the first time from Uncaria rhynchophylla, might be able to protect against neurodegeneration in vitro, and, therefore, the molecular mechanism deserves further study. This finding may also increase interest in the health benefits of Uncaria rhynchophylla.

Inhibition of collagen production in scleroderma fibroblast cultures by a connective tissue glycoprotein extracted from normal dermis

International Nuclear Information System (INIS)

Maquart, F.X.; Bellon, G.; Cornillet-Stoupy, J.; Randoux, A.; Triller, R.; Kalis, B.; Borel, J.P.

1985-01-01

It was shown in a previous paper that a connective tissue glycoprotein (CTGP) extracted from normal rabbit dermis was able to inhibit total protein and collagen syntheses by normal dermis fibroblast cultures. In the present study, the effects of CTGP on scleroderma fibroblasts were investigated. [ 14 C]Proline incorporation into total proteins of the supernatant was not significantly different from that found in controls. By contrast, the amount of collagen, expressed as percentage of total secreted protein, was far higher in scleroderma cultures than in normal ones (14.4% +/- 6.0% vs 4.6% +/- 0.9%). Addition of CTGP to the medium induced a concentration-dependent inhibition of [ 14 C]proline incorporation into proteins from both control and scleroderma cells. In control cultures, no significant decrease of the percentage of collagen was observed, but over 60 micrograms/ml, both cytotoxic effects and inhibition of protein synthesis occurred. In scleroderma cultures, the inhibition was twice as effective on collagen as on noncollagen protein synthesis. The inhibition of collagen secretion was not related either to changes in collagen hydroxylation or to the intracellular catabolism of newly synthesized procollagen

5 CFR 534.203 - Maximum stipends.

Science.gov (United States)

2010-01-01

... maximum stipend established under this section. (e) A trainee at a non-Federal hospital, clinic, or medical or dental laboratory who is assigned to a Federal hospital, clinic, or medical or dental... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY UNDER OTHER SYSTEMS Student...

Influence of maximum bite force on jaw movement during gummy jelly mastication.

Science.gov (United States)

Kuninori, T; Tomonari, H; Uehara, S; Kitashima, F; Yagi, T; Miyawaki, S

2014-05-01

It is known that maximum bite force has various influences on chewing function; however, there have not been studies in which the relationships between maximum bite force and masticatory jaw movement have been clarified. The aim of this study was to investigate the effect of maximum bite force on masticatory jaw movement in subjects with normal occlusion. Thirty young adults (22 men and 8 women; mean age, 22.6 years) with good occlusion were divided into two groups based on whether they had a relatively high or low maximum bite force according to the median. The maximum bite force was determined according to the Dental Prescale System using pressure-sensitive sheets. Jaw movement during mastication of hard gummy jelly (each 5.5 g) on the preferred chewing side was recorded using a six degrees of freedom jaw movement recording system. The motion of the lower incisal point of the mandible was computed, and the mean values of 10 cycles (cycles 2-11) were calculated. A masticatory performance test was conducted using gummy jelly. Subjects with a lower maximum bite force showed increased maximum lateral amplitude, closing distance, width and closing angle; wider masticatory jaw movement; and significantly lower masticatory performance. However, no differences in the maximum vertical or maximum anteroposterior amplitudes were observed between the groups. Although other factors, such as individual morphology, may influence masticatory jaw movement, our results suggest that subjects with a lower maximum bite force show increased lateral jaw motion during mastication. © 2014 John Wiley & Sons Ltd.

Maximum parsimony on subsets of taxa.

Science.gov (United States)

Fischer, Mareike; Thatte, Bhalchandra D

2009-09-21

In this paper we investigate mathematical questions concerning the reliability (reconstruction accuracy) of Fitch's maximum parsimony algorithm for reconstructing the ancestral state given a phylogenetic tree and a character. In particular, we consider the question whether the maximum parsimony method applied to a subset of taxa can reconstruct the ancestral state of the root more accurately than when applied to all taxa, and we give an example showing that this indeed is possible. A surprising feature of our example is that ignoring a taxon closer to the root improves the reliability of the method. On the other hand, in the case of the two-state symmetric substitution model, we answer affirmatively a conjecture of Li, Steel and Zhang which states that under a molecular clock the probability that the state at a single taxon is a correct guess of the ancestral state is a lower bound on the reconstruction accuracy of Fitch's method applied to all taxa.

Inhibition of serine palmitoyltransferase in vitro and long-chain base biosynthesis in intact Chinese hamster ovary cells by β-chloroalanine

International Nuclear Information System (INIS)

Medlock, K.A.; Merrill, A.H. Jr.

1988-01-01

The effects of β-chloroalanine (β-Cl-alanine) on the serine palmitoyltransferase activity and the de novo biosynthesis of sphinganine and sphingenine were investigated in vitro with rat liver microsomes and in vivo with intact Chinese hamster ovary (CHO) cells. The inhibition in vitro was rapid, irreversible, and concentration and time dependent and apparently involved the active site because inactivation only occurred with β-Cl-L-alanine and was blocked by L-serine. These are characteristics of mechanism-based (suicide) inhibition. Serine palmitoyltransferase (SPT) was also inhibited when intact CHO cells were incubated with β-Cl-alanine and this treatment inhibited [ 14 C]serine incorporation into long-chain bases by intact cells. The concentration dependence of the loss of SPT activity and of long-chain base synthesis was identical. The effects of β-Cl-alanine appeared to occur with little perturbation of other cell functions: the cells exhibited no loss in cell viability, [ 14 C]serine uptake was not blocked, total lipid biosynthesis from [ 14 C]acetic acid was not decreased (nor was the appearance of radiolabel in cholesterol and phosphatidylcholine), and [ 3 H]thymidine incorporation into DNA was not affected. There appeared to be little effect on protein synthesis based on the incorporation of [ 3 H]leucine, which was only decreased by 14%. Although β-Cl-L-alanine is known to inhibit other pyridoxal 5'-phosphate dependent enzymes, alanine and aspartate transaminases were not inhibited under these conditions. These results establish the close association between the activity of serine palmitoyltransferase and the cellular rate of long-chain base formation and indicate that β-Cl-alanine and other mechanism-based inhibitors might be useful to study alterations in cellular long-chain base synthesis

In vitro inhibition of phenolsulphotransferase by food and drink constituents.

Science.gov (United States)

Gibb, C; Glover, V; Sandler, M

1987-07-15

Several natural and synthetic food and drink constituents were tested in vitro for their inhibitory actions on phenolsulphotransferase P and M (PST P, PST M) and monoamine oxidase A and B (MAO A, MAO B). Cyanidin 3-rutinoside, a simple anthocyanin, (+)-catechin, a flavanol, and carmoisine, a synthetic food colorant, were found to be particularly potent, reversible inhibitors of PST P. All inhibited this enzyme by 100% at a concentration of 5 microM and had an IC50 in the microM range. The effects of these compounds on PST M and MAO A and B were less pronounced. There was a considerable difference in the inhibitory ability of different purified anthocyanins but all were selective for PST P. Several other phenolic food colorants were also found to be specific inhibitors of PST P, though less potent in their actions. Tartrazine, a non-phenolic food colorant, had little effect. The phenolic extracts from two red wines were also found selectively to inhibit PST P in vitro, suggesting that it is within this fraction that these inhibitors are to be found. PST is an important enzyme involved in the inactivation of a wide range of exogenous and endogenous phenols. If such a degree of inhibition were to occur in vivo, potentially toxic concentrations of some phenolic substrates might result.

Nitrogen-responsive Regulation of GATA Protein Family Activators Gln3 and Gat1 Occurs by Two Distinct Pathways, One Inhibited by Rapamycin and the Other by Methionine Sulfoximine*

Science.gov (United States)

Georis, Isabelle; Tate, Jennifer J.; Cooper, Terrance G.; Dubois, Evelyne

2011-01-01

Nitrogen availability regulates the transcription of genes required to degrade non-preferentially utilized nitrogen sources by governing the localization and function of transcription activators, Gln3 and Gat1. TorC1 inhibitor, rapamycin (Rap), and glutamine synthetase inhibitor, methionine sulfoximine (Msx), elicit responses grossly similar to those of limiting nitrogen, implicating both glutamine synthesis and TorC1 in the regulation of Gln3 and Gat1. To better understand this regulation, we compared Msx- versus Rap-elicited Gln3 and Gat1 localization, their DNA binding, nitrogen catabolite repression-sensitive gene expression, and the TorC1 pathway phosphatase requirements for these responses. Using this information we queried whether Rap and Msx inhibit sequential steps in a single, linear cascade connecting glutamine availability to Gln3 and Gat1 control as currently accepted or alternatively inhibit steps in two distinct parallel pathways. We find that Rap most strongly elicits nuclear Gat1 localization and expression of genes whose transcription is most Gat1-dependent. Msx, on the other hand, elicits nuclear Gln3 but not Gat1 localization and expression of genes that are most Gln3-dependent. Importantly, Rap-elicited nuclear Gln3 localization is absolutely Sit4-dependent, but that elicited by Msx is not. PP2A, although not always required for nuclear GATA factor localization, is highly required for GATA factor binding to nitrogen-responsive promoters and subsequent transcription irrespective of the gene GATA factor specificities. Collectively, our data support the existence of two different nitrogen-responsive regulatory pathways, one inhibited by Msx and the other by rapamycin. PMID:22039046

Nitrogen-responsive regulation of GATA protein family activators Gln3 and Gat1 occurs by two distinct pathways, one inhibited by rapamycin and the other by methionine sulfoximine.

Science.gov (United States)

Georis, Isabelle; Tate, Jennifer J; Cooper, Terrance G; Dubois, Evelyne

2011-12-30

Nitrogen availability regulates the transcription of genes required to degrade non-preferentially utilized nitrogen sources by governing the localization and function of transcription activators, Gln3 and Gat1. TorC1 inhibitor, rapamycin (Rap), and glutamine synthetase inhibitor, methionine sulfoximine (Msx), elicit responses grossly similar to those of limiting nitrogen, implicating both glutamine synthesis and TorC1 in the regulation of Gln3 and Gat1. To better understand this regulation, we compared Msx- versus Rap-elicited Gln3 and Gat1 localization, their DNA binding, nitrogen catabolite repression-sensitive gene expression, and the TorC1 pathway phosphatase requirements for these responses. Using this information we queried whether Rap and Msx inhibit sequential steps in a single, linear cascade connecting glutamine availability to Gln3 and Gat1 control as currently accepted or alternatively inhibit steps in two distinct parallel pathways. We find that Rap most strongly elicits nuclear Gat1 localization and expression of genes whose transcription is most Gat1-dependent. Msx, on the other hand, elicits nuclear Gln3 but not Gat1 localization and expression of genes that are most Gln3-dependent. Importantly, Rap-elicited nuclear Gln3 localization is absolutely Sit4-dependent, but that elicited by Msx is not. PP2A, although not always required for nuclear GATA factor localization, is highly required for GATA factor binding to nitrogen-responsive promoters and subsequent transcription irrespective of the gene GATA factor specificities. Collectively, our data support the existence of two different nitrogen-responsive regulatory pathways, one inhibited by Msx and the other by rapamycin.

Inhibition of the alpha-ketoglutarate dehydrogenase complex alters mitochondrial function and cellular calcium regulation.

Science.gov (United States)

Huang, Hsueh-Meei; Zhang, Hui; Xu, Hui; Gibson, Gary E

2003-01-20

Mitochondrial dysfunction occurs in many neurodegenerative diseases. The alpha-ketoglutarate dehydrogenase complex (KGDHC) catalyzes a key and arguably rate-limiting step of the tricarboxylic acid cycle (TCA). A reduction in the activity of the KGDHC occurs in brains and cells of patients with many of these disorders and may underlie the abnormal mitochondrial function. Abnormalities in calcium homeostasis also occur in fibroblasts from Alzheimer's disease (AD) patients and in cells bearing mutations that lead to AD. Thus, the present studies test whether the reduction of KGDHC activity can lead to the alterations in mitochondrial function and calcium homeostasis. alpha-Keto-beta-methyl-n-valeric acid (KMV) inhibits KGDHC activity in living N2a cells in a dose- and time-dependent manner. Surprisingly, concentration of KMV that inhibit in situ KGDHC by 80% does not alter the mitochondrial membrane potential (MMP). However, similar concentrations of KMV induce the release of cytochrome c from mitochondria into the cytosol, reduce basal [Ca(2+)](i) by 23% (Pcalcium release from the endoplasmic reticulum (ER) by 46% (P<0.005). This result suggests that diminished KGDHC activities do not lead to the Ca(2+) abnormalities in fibroblasts from AD patients or cells bearing PS-1 mutations. The increased release of cytochrome c with diminished KGDHC activities will be expected to activate other pathways including cell death cascades. Reductions in this key mitochondrial enzyme will likely make the cells more vulnerable to metabolic insults that promote cell death.

Experimental and theoretical investigation on corrosion inhibition of AA5052 aluminium alloy by L-cysteine in alkaline solution

Energy Technology Data Exchange (ETDEWEB)

Wang, Dapeng; Gao, Lixin [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Zhang, Daquan, E-mail: zhangdaquan@shiep.edu.cn [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Yang, Dong [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Hongxia; Lin, Tong [Institute for Frontier Materials, Deakin University, Geelong, VIC 3216 (Australia)

2016-02-01

The corrosion inhibition of L-cysteine on AA5052 aluminium alloy in 4 mol/L NaOH solution was investigated by hydrogen gas evolution experiment, polarisation curve, galvanostatic discharge, electrochemical impedance spectroscopy measurements and quantum chemical calculations. The adsorption of L-cysteine on aluminium alloy surface obeyed the amended Langmuir's adsorption isotherm. The polarisation curves indicated that L-cysteine acted as a cathodic inhibitor to inhibit cathodic reaction. The inhibition mechanism was dominated by the geometric covering effect. The galvanostatic discharge shows that the additives restrain the hydrogen evolution and increase the anodic utilization rate. Quantum chemical calculations indicated that L-cysteine molecules mainly interacted with on the carboxyl groups on the aluminium alloy surface. A strong hybridization occurred between the s-orbital and p-orbital of reactive sites in the L-cysteine molecule and the sp-orbital of Aluminium. - Highlights: • L-cysteine was used as corrosion inhibitor for Al alloy in alkaline solution. • Adsorption of L-cysteine on Al alloy surface obeyed the amended Langmuir's isotherm. • L-cysteine molecules interacted with the carboxyl groups on the Al alloy surface. • A strong orbital hybridization occurred between the reactive sites in L-cysteine and Al.

Fisetin suppresses ADAM9 expression and inhibits invasion of glioma cancer cells through increased phosphorylation of ERK1/2.

Science.gov (United States)

Chen, Chien-Min; Hsieh, Yi-Hsien; Hwang, Jin-Ming; Jan, Hsun-Jin; Hsieh, Shu-Ching; Lin, Shin-Huey; Lai, Chung-Yu

2015-05-01

Fisetin (3,3',4',7-tetrahydroxyflavone) is a naturally occurring flavonoid which is widely distributed in plants. It has been reported to possess some anticancer and anti-invasive capabilities. We set out to explore the effects of fisetin on antimetastatic and its mechanism of action in GBM8401 cells. The results indicated that fisetin exhibited effective inhibition of cell migration and inhibited the invasion of GBM8401 cells under non-cytotoxic concentrations. To identify the potential targets of fisetin, human proteinase antibody array analysis was performed, and the results indicated that the fisetin treatment inhibited the expression of ADAM9 protein and mRNA, which are known to contribute to the progression of glioma cancer. Our results showed that fisetin phosphorylated ERK1/2 in a sustained way that contributed to the inhibited ADAM9 protein and mRNA expression determined by Western blot and RT-PCR. Moreover, inhibition of ERK1/2 by U0126 or transfection with the siERK plasmid significantly abolished the fisetin-inhibited migration and invasion through activation of the ERK1/2 pathway. In summary, our results suggest that fisetin might be a potential therapeutic agent against human glioma cells based on its capacity to activate ERK1/2 and to inhibit ADAM9 expression.

Inhibition of X-ray-induced potentially lethal damage (PLD) repair in aerobic plateau-phase Chinese hamster cells by misonidazole

International Nuclear Information System (INIS)

Brown, D.M.

1984-01-01

The effect of the 2-nitroimidazole radiosensitizer misonidazole (MISO) and the hydrophilic analog SR-2508 on the repair of X-ray-induced potentially lethal damage (PLD) was studied in plateau-phase Chinese Hamster ovary (HA-1) cells. It was found that although MISO does not radiosensitize aerobic cells, it inhibits the repair of PLD. However, under hypoxic conditions, MISO has no effect on PLD repair. The major portion of the inhibition of PLD repair in aerobic cells requires the presence of MISO only during irradiation; little or no additional inhibition occurs when MISO is present during the postirradiation repair period. Also, treatment of aerobic cells with 5 mM MISO for either 5 or 30 min prior to irradiation is equally inhibitory. This suggests that the presence of MISO in some way modifies the initial lesion under aerobic conditions since it does not increase cell killing as determined by immediate plating but inhibits subsequent repair. The inhibition is concentration dependent; 0.5 mM MISO inhibits PLD repair by one-half while 5-10 mM totally inhibits the repair measured 6 hr postirradiation. This phenomenon suggests that radiosensitization of tissue in vivo by MISO and other 2-nitroimidazoles may not be unequivocal proof of the presence of hypoxic cells

The mode of inhibition of the Na+-K+ pump activity in mast cells by calcium

DEFF Research Database (Denmark)

Knudsen, T; Johansen, Torben

1989-01-01

, and hence the pump activity. This hypothesis is supported by the stimulation of pump activity produced by monensin, which is not inhibited by calcium. The enhancement of pump activity after exposure of calcium-deprived cells to EGTA might be the result of a further increase in the sodium permeability......1 The inhibition by calcium of the Na(+)-K+ pump in the plasma membrane of rat peritoneal mast cells was studied in pure populations of the cells by measuring the ouabain-sensitive uptake of the radioactive potassium analogue, 86rubidium (86Rb+). 2 Exposure of the cells to calcium induced a time......- and concentration-dependent decrease in the ouabain-sensitive K+(86Rb+)-uptake of the cells without influencing the ouabain-resistant uptake. The development of the inhibition required the presence of potassium in the medium in the millimolar range (1.5-8.0 mM), and it did not occur at a concentration of potassium...

Neural correlates of saccadic inhibition in healthy elderly and patients with amnestic mild cognitive impairment

Science.gov (United States)

Alichniewicz, K. K.; Brunner, F.; Klünemann, H. H.; Greenlee, M. W.

2013-01-01

Performance on tasks that require saccadic inhibition declines with age and altered inhibitory functioning has also been reported in patients with Alzheimer's disease. Although mild cognitive impairment (MCI) is assumed to be a high-risk factor for conversion to AD, little is known about changes in saccadic inhibition and its neural correlates in this condition. Our study determined whether the neural activation associated with saccadic inhibition is altered in persons with amnestic mild cognitive impairment (aMCI). Functional magnetic resonance imaging (fMRI) revealed decreased activation in parietal lobe in healthy elderly persons compared to young persons and decreased activation in frontal eye fields in aMCI patients compared to healthy elderly persons during the execution of anti-saccades. These results illustrate that the decline in inhibitory functions is associated with impaired frontal activation in aMCI. This alteration in function might reflect early manifestations of AD and provide new insights in the neural activation changes that occur in pathological ageing. PMID:23898312

LQG and maximum entropy control design for the Hubble Space Telescope

Science.gov (United States)

Collins, Emmanuel G., Jr.; Richter, Stephen

Solar array vibrations are responsible for serious pointing control problems on the Hubble Space Telescope (HST). The original HST control law was not designed to attenuate these disturbances because they were not perceived to be a problem prior to launch. However, significant solar array vibrations do occur due to large changes in the thermal environment as the HST orbits the earth. Using classical techniques, Marshall Space Flight Center in conjunction with Lockheed Missiles and Space Company developed modified HST controllers that were able to suppress the influence of the vibrations of the solar arrays on the line-of-sight (LOS) performance. Substantial LOS improvement was observed when two of these controllers were implemented on orbit. This paper describes the development of modified HST controllers by using modern control techniques, particularly linear-quadratic-gaussian (LQG) design and Maximum Entropy robust control design, a generalization of LQG that incorporates robustness constraints with respect to modal errors. The fundamental issues are discussed candidly and controllers designed using these modern techniques are described.

Maintenance of ovulation inhibition with a new progestogen-only pill containing drospirenone after scheduled 24-h delays in pill intake

DEFF Research Database (Denmark)

Duijkers, Ingrid J M; Heger-Mahn, Doris; Drouin, Dominique

2016-01-01

by four placebo tablets. A previous study showed that this new drospirenone-only pill effectively inhibited ovulation. Clinical efficacy, however, can be affected by compliance, and delayed or forgotten pill intake often occurs in daily life. The aim of this study was to investigate if inhibition.......8%; only one subject in Group A fulfilled the ovulation criteria in Cycle 2. Follicular diameters in the regular-intake and the delayed-intake cycles were similar. CONCLUSION: Despite the 4-day hormone-free period and multiple intentional 24-h delays in tablet intake, ovulation inhibition was maintained...... inhibition by the new-generation oestrogen-free pill, containing 4-mg drospirenone for 24 days followed by a 4-day treatment-free period, was maintained despite four 24-h delays in tablet intake, so the impact of delayed intake on contraceptive reliability will be low....

Inhibition of polyphenoloxidase by sulfite

International Nuclear Information System (INIS)

Sayavedra-Soto, L.A.; Montgomery, M.W.

1986-01-01

When polyphenoloxidase (PPO) was exposed to sulfite prior to substrate addition, inhibition was irreversible. Trials to regenerate PPO activity, using extensive dialysis, column chromatography, and addition of copper salts were not successful. Increased concentrations of sulfite and pH levels less than 5 enhanced the inhibition of PPO by sulfite. At pH 4, concentrations greater than 0.04 mg/mL completely inhibited 1000 units of PPO activity almost instantaneously. This suggested that the HSO 3 - molecule was the main component in the sulfite system inhibiting PPO. Column chromatography, extensive dialysis, and gel electrophoresis did not demonstrate 35 SO 2 bound to purified pear PPO protein. Formation of extra protein bands of sulfite inhibited purified pear PPO fractions on gel electrophoresis was demonstrated. This and other evidence suggested that the major mode of direct irreversible inhibition of PPO was modification of the protein structure, with retention of its molecular unity

Ursodeoxycholic acid inhibits TNFα-induced IL-8 release from monocytes.

Science.gov (United States)

O'Dwyer, Aoife M; Lajczak, Natalia K; Keyes, Jennifer A; Ward, Joseph B; Greene, Catherine M; Keely, Stephen J

2016-08-01

Monocytes are critical to the pathogenesis of inflammatory bowel disease (IBD) as they infiltrate the mucosa and release cytokines that drive the inflammatory response. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid with anti-inflammatory actions, has been proposed as a potential new therapy for IBD. However, its effects on monocyte function are not yet known. Primary monocytes from healthy volunteers or cultured U937 monocytes were treated with either the proinflammatory cytokine, TNFα (5 ng/ml) or the bacterial endotoxin, lipopolysaccharide (LPS; 1 μg/ml) for 24 h, in the absence or presence of UDCA (25-100 μM). IL-8 release into the supernatant was measured by ELISA. mRNA levels were quantified by qPCR and changes in cell signaling proteins were determined by Western blotting. Toxicity was assessed by measuring lactate dehydrogenase (LDH) release. UDCA treatment significantly attenuated TNFα-, but not LPS-driven, release of IL-8 from both primary and cultured monocytes. UDCA inhibition of TNFα-driven responses was associated with reduced IL-8 mRNA expression. Both TNFα and LPS stimulated NFκB activation in monocytes, while IL-8 release in response to both cytokines was attenuated by an NFκB inhibitor, BMS-345541. Interestingly, UDCA inhibited TNFα-, but not LPS-stimulated, NFκB activation. Finally, TNFα, but not LPS, induced phosphorylation of TNF receptor associated factor (TRAF2), while UDCA cotreatment attenuated this response. We conclude that UDCA specifically inhibits TNFα-induced IL-8 release from monocytes by inhibiting TRAF2 activation. Since such actions would serve to dampen mucosal immune responses in vivo, our data support the therapeutic potential of UDCA for IBD. Copyright © 2016 the American Physiological Society.

Maximum length scale in density based topology optimization

DEFF Research Database (Denmark)

Lazarov, Boyan Stefanov; Wang, Fengwen

2017-01-01

The focus of this work is on two new techniques for imposing maximum length scale in topology optimization. Restrictions on the maximum length scale provide designers with full control over the optimized structure and open possibilities to tailor the optimized design for broader range...... of manufacturing processes by fulfilling the associated technological constraints. One of the proposed methods is based on combination of several filters and builds on top of the classical density filtering which can be viewed as a low pass filter applied to the design parametrization. The main idea...

In Vitro Ability of Currently Available Oximes to Reactivate Organophosphate Pesticide-Inhibited Human Acetylcholinesterase and Butyrylcholinesterase

Directory of Open Access Journals (Sweden)

Kamil Musilek

2011-03-01

Full Text Available We have in vitro tested the ability of common, commercially available, cholinesterase reactivators (pralidoxime, obidoxime, methoxime, trimedoxime and HI-6 to reactivate human acetylcholinesterase (AChE, inhibited by five structurally different organophosphate pesticides and inhibitors (paraoxon, dichlorvos, DFP, leptophos-oxon and methamidophos. We also tested reactivation of human butyrylcholinesterase (BChE with the aim of finding a potent oxime, suitable to serve as a “pseudocatalytic” bioscavenger in combination with this enzyme. Such a combination could allow an increase of prophylactic and therapeutic efficacy of the administered enzyme. According to our results, the best broad-spectrum AChE reactivators were trimedoxime and obidoxime in the case of paraoxon, leptophos-oxon, and methamidophos-inhibited AChE. Methamidophos and leptophos-oxon were quite easily reactivatable by all tested reactivators. In the case of methamidophos-inhibited AChE, the lower oxime concentration (10−5 M had higher reactivation ability than the 10−4 M concentration. Therefore, we evaluated the reactivation ability of obidoxime in a concentration range of 10−3–10−7 M. The reactivation of methamidophos-inhibited AChE with different obidoxime concentrations resulted in a bell shaped curve with maximum reactivation at 10−5 M. In the case of BChE, no reactivator exceeded 15% reactivation ability and therefore none of the oximes can be recommended as a candidate for “pseudocatalytic” bioscavengers with BChE.

PTree: pattern-based, stochastic search for maximum parsimony phylogenies

OpenAIRE

Gregor, Ivan; Steinbr?ck, Lars; McHardy, Alice C.

2013-01-01

Phylogenetic reconstruction is vital to analyzing the evolutionary relationship of genes within and across populations of different species. Nowadays, with next generation sequencing technologies producing sets comprising thousands of sequences, robust identification of the tree topology, which is optimal according to standard criteria such as maximum parsimony, maximum likelihood or posterior probability, with phylogenetic inference methods is a computationally very demanding task. Here, we ...

Studies on `allergoids' prepared from naturally occurring allergens

Science.gov (United States)

Marsh, D. G.; Lichtenstein, L. M.; Campbell, D. H.

1970-01-01

The highly purified major allergenic component of rye grass pollen (Group I) was used to investigate the possibility of destroying selectively the allergenic properties of an antigen, while largely retaining its original immunizing capacities. The allergen was treated under mild conditions with formalin alone or formalin plus a reactive low molecular weight additive. Certain derivatives (allergoids) showed well over 99 per cent reduction in allergenicity, determined by the histamine released from allergic human leucocytes in vitro, but were still able to combine with rabbit antibody against native antigen. Furthermore, the allergoids stimulated production (in guinea-pigs) of appreciable amounts of antibody able to inhibit native allergen-mediated human allergic histamine release in vitro and to cross-react with native antigen by PCA tests in normal guinea-pigs. Residual allergenicity and cross-immunogenicity (by the inhibition assay) of the different formalinized derivatives varied appreciably according to the additive used in formalinization, but the cross-reactivities of the different preparations in quantitative precipitin analysis against rabbit anti-native antigen serum were similar. The residual allergenicities of individual derivatives varied by up to 1000-fold in different cell preparations, suggesting a heterogeneity of allergenic determinants. Allergoid derivatives showed no hapten-like activity in that they were unable to inhibit allergen-mediated histamine release from leucocytes. The theoretical and practical application of allergoids is discussed, including their potential usefulness in improving the immunotheraphy of atopic humans. ImagesFIG. 2 PMID:4192674

Experimental assessment of the role of the blood flow inhibition in hyperglycemia-enhanced radiation injury to tumor

International Nuclear Information System (INIS)

Kozin, S.V.; Sevast'yanov, A.I.; Yarmonenko, S.P.

1986-01-01

Experimental assessment of the role of the blood flow inhibition in enhancement of radiation injury to tumors using short-term hyperglycemia was provided. Experiments on mice with Ehrlich solid carcinoma showed the dependence of a rise of the antitumor effect of preceding radiation induced by glucose and glucose combined with mexamin on a degree of the blood flow inhibition under the influence of these modifying agents. It was established that a considerable enhancement of radiation injury occured but in such tumors where short-term hyperglycemia and mexamin decreased the blood flow level not less than 5-10 fold as estimated by 133 Xe clearance. The results of the above experiments showed that the noticeable inhibition of the blood flow in tumors was a necessary tough, probably, not the only condition for a high efficacy of short-term hyperglycemia used an ajuvant to radiotherapy

Pharmacological inhibition of dynamin II reduces constitutive protein secretion from primary human macrophages.

Directory of Open Access Journals (Sweden)

Maaike Kockx

Full Text Available Dynamins are fission proteins that mediate endocytic and exocytic membrane events and are pharmacological therapeutic targets. These studies investigate whether dynamin II regulates constitutive protein secretion and show for the first time that pharmacological inhibition of dynamin decreases secretion of apolipoprotein E (apoE and several other proteins constitutively secreted from primary human macrophages. Inhibitors that target recruitment of dynamin to membranes (MiTMABs or directly target the GTPase domain (Dyngo or Dynole series, dose- and time- dependently reduced the secretion of apoE. SiRNA oligo's targeting all isoforms of dynamin II confirmed the involvement of dynamin II in apoE secretion. Inhibition of secretion was not mediated via effects on mRNA or protein synthesis. 2D-gel electrophoresis showed that inhibition occurred after apoE was processed and glycosylated in the Golgi and live cell imaging showed that inhibited secretion was associated with reduced post-Golgi movement of apoE-GFP-containing vesicles. The effect was not restricted to macrophages, and was not mediated by the effects of the inhibitors on microtubules. Inhibition of dynamin also altered the constitutive secretion of other proteins, decreasing the secretion of fibronectin, matrix metalloproteinase 9, Chitinase-3-like protein 1 and lysozyme but unexpectedly increasing the secretion of the inflammatory mediator cyclophilin A. We conclude that pharmacological inhibitors of dynamin II modulate the constitutive secretion of macrophage apoE as a class effect, and that their capacity to modulate protein secretion may affect a range of biological processes.

The maximum significant wave height in the Southern North Sea

NARCIS (Netherlands)

Bouws, E.; Tolman, H.L.; Holthuijsen, L.H.; Eldeberky, Y.; Booij, N.; Ferier, P.

1995-01-01

The maximum possible wave conditions along the Dutch coast, which seem to be dominated by the limited water depth, have been estimated in the present study with numerical simulations. Discussions with meteorologists suggest that the maximum possible sustained wind speed in North Sea conditions is

Maximum mass ratio of AM CVn-type binary systems and maximum white dwarf mass in ultra-compact X-ray binaries

Directory of Open Access Journals (Sweden)

Arbutina Bojan

2011-01-01

Full Text Available AM CVn-type stars and ultra-compact X-ray binaries are extremely interesting semi-detached close binary systems in which the Roche lobe filling component is a white dwarf transferring mass to another white dwarf, neutron star or a black hole. Earlier theoretical considerations show that there is a maximum mass ratio of AM CVn-type binary systems (qmax ≈ 2/3 below which the mass transfer is stable. In this paper we derive slightly different value for qmax and more interestingly, by applying the same procedure, we find the maximum expected white dwarf mass in ultra-compact X-ray binaries.

Size dependence of efficiency at maximum power of heat engine

KAUST Repository

Izumida, Y.; Ito, N.

2013-01-01

We perform a molecular dynamics computer simulation of a heat engine model to study how the engine size difference affects its performance. Upon tactically increasing the size of the model anisotropically, we determine that there exists an optimum size at which the model attains the maximum power for the shortest working period. This optimum size locates between the ballistic heat transport region and the diffusive heat transport one. We also study the size dependence of the efficiency at the maximum power. Interestingly, we find that the efficiency at the maximum power around the optimum size attains a value that has been proposed as a universal upper bound, and it even begins to exceed the bound as the size further increases. We explain this behavior of the efficiency at maximum power by using a linear response theory for the heat engine operating under a finite working period, which naturally extends the low-dissipation Carnot cycle model [M. Esposito, R. Kawai, K. Lindenberg, C. Van den Broeck, Phys. Rev. Lett. 105, 150603 (2010)]. The theory also shows that the efficiency at the maximum power under an extreme condition may reach the Carnot efficiency in principle.© EDP Sciences Società Italiana di Fisica Springer-Verlag 2013.

Size dependence of efficiency at maximum power of heat engine