Using hydrogen at high pressures of up to 150 bar as an OH scavenger in aqueous MV"2"+ solutions (pH 1) it is possible to differentiate between two kinds of transient formed simultaneously by H-atom attack on methyl viologen. One of them is assigned to an H adduct on the N atom, MV"+H"+, with absorption bands identical to those of the radical cation, MV"+. The MV"+H"+ species deprotonates forming the long-lived radical cation, MV"+. The second type of transient produced is attributed to an H-adduct on the ring carbon, MV"2"+H, decaying by second-order kinetics. The formation of MV"+ by electron transfer from the propan-2-ol radical has been reinvestigated (pH 0 to 7); its absorption spectrum does not change in this pH range. Rate constants and molar extinction coefficients are presented. (U.K.).
The reactions of native bovine catalase with superoxide and solvated electrons have been investigated using three different methods for generating these reducing substrates: [gamma]-radiolysis of oxygenated or deaerated buffer solutions in the presence of an OH radicalscavenger; either xanthine or acetaldehyde with xanthine oxidase; and low-temperature (77 K) [gamma]-radiolysis of buffered ethylene glycol/water solutions with subsequent annealing of samples at 183 K. (Author).
The extracts from kinnow peel, kinnow seeds, litchi pericarp, litchi seeds, grape seeds, and banana peel were screened for total phenolic content (TPC), trolox equivalent antioxidant capacity (TEAC), 1,1 diphenyl-2-picryl hydrazyl (DPPH) radicalscavenging activity, as well as reducing power. Kinnow peel extract exhibited the highest reducing power, TEAC, and DPPH free radicalscavenging activity, whereas, the phenolic content of 37.4 mg GAE/g-dw was highest for grape seed extract. Banana peel extract with a low TPC showed the lowest reducing power, TEAC as well as DPPH free radicalscavenging activity among the fruit residue extracts examined in the present study. Correlation analysis between the reducing power and DPPH radicalscavenging ability; reducing power and ABTS radical scavengin...
BackgroundTrichloroethylene (TCE) may induce oxidative stress which generates free radicals and alters antioxidants or oxygen-free radicalscavenging enzymes.MethodsTwenty...Full Text Available
Formation of oxidizing and reducing radicals was studied by pulse radiolysis of [Fe(CN)_6]"4"- - BrO_3"- - CN"- system in ethylene glycol - water solvent mixture. Oxidizing #centre dot#BrO_2 and BrO radicals formed by electron scavenging with #centre dot#BrO_2"- were identified and their reactions were investigated. The reaction of hydroxyl radicals with ethylene glycol leads to formation of reactive radicals with reducing properties and of compounds which reduce slowly in dark the ferricyanide formed in the reaction of #centre dot#BrO_2 radical with ferrocyanide. (author) 21 refs.; 7 figs.
A solvent extraction method was developed to obtain methanolic extracts rich in antioxidants from banana peel. Central composite design ''2^3+star'' and response surface methodology were used in order to optimise the number of extraction steps, extraction temperature and extraction time. The number of extractions was statistically the most significant factor in scavenging activity against both DPPH? and ABTS?^+ radicals and in the inhibition of TBARS formation, while the extraction temperature had an important impact on the capacity to prevent b-carotene bleaching. However, the effect of the extraction time on antioxidant activity was less important. The optimum values of the factors that influence the capacity to scavenge DPPH? and ABTS?^+ radicals or to inhibit b-carotene bleaching were ...
Abstract Green tea extract showed false-negative results in the determination of glucose via glucose oxidase (GOD) test. This investigation was undertaken to verify and find out the precise mechanism underlying this interference by determining the reaction kinetics of production and reduction of end-point chromophore. The peroxidase step of the GOD test was found to be interfered and phenols of the green tea were the interfering compounds. Green tea interfered and exerted its influence in a dual fashion. A part of the interference was observed as a result of the reduction of the finally formed chromophore, whereas the other form of interference was due to its hydrogen peroxide/free radical-scavenging activity. Reducing potential and the free radical-scavenging activity of the phenols in th...
Three alternative extraction procedures were carried out in order to separate the antioxidant components and isolate an efficient extract from Origanum dictamnus. Procedure A included sequential extractions with petroleum ether (PE), diethyl ether (DE) and ethanol; procedure B sequential extractions with PE and ethyl acetate (EAc); procedure C a single step extraction with ethanol. The most efficient radicalscavengers, according to the DPPH method, were isolated in ethanol extract of procedure A (mainly rosmarinic acid), followed by ethanol extract of procedure C. However, both ethanol extracts had low solubility in oil and could not protect it. EAc and DE extracts, containing mainly apigenin and epirosmanol ethyl ether, presented lower radicalscavenging activity but were very effective ...
Banana (Musa acuminata Colla AAA) peel extracts obtained in this work had a high capacity to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2prime-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS+) free radicals, and they were also good lipid peroxidation inhibitors. Acetone:water extracts were considerably more effective (compared with methanol, ethanol, acetone, water, methanol:water or ethanol:water) at inhibiting the peroxidation of lipids in the b-carotene/linoleic acid system or scavenging free radicals. However, aqueous extracts had a high capacity to protect lipids from oxidation in the thiobarbituric acid reactive substances (TBARS) test, as well as in the b-carotene bleaching assay. In addition, acetone:water most efficiently extracted all extractable components (54+-...
The antioxidant properties of magnolol and honokiol were evaluated in the experimental systems of reducing ONOO^- and ^1O"2, bleaching @b-carotene in linoleic acid (LH) emulsion, and trapping 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) cationic radical (ABTS^+?) and 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH), and then were applied to inhibit the oxidation of DNA induced by Cu^2^+/glutathione (GSH) and 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH). Magnolol and honokiol were active to reduce ONOO^- and ^1O"2. Honokiol showed a little higher activity to protect LH and to inhibit Cu^2^+/GSH-induced oxidation of DNA than magnolol. In addition, honokiol exhibited higher activities to trap ABTS^+? and DPPH than magnolol. In particular, honokiol trapped 2.5 radicals while magnolol o...
The phlebotomine sand fly Lutzomyia longipalpis is the most important vector of American visceral leishmaniasis (AVL), the disseminated and most serious form of the disease in Central...Full Text Available
The purpose was to study the toxicity of drugs known to generate free radicals on isolated pancreatic islets. The accumulattion of "8"6Rb"+ by mouse pancreatic islets was measured in vitro. Exposing the islets to 6-hydroxydopamine, minhydrin, or phenazine methosulphate + NADH inhibited the Rb"+ uptake, whereas paraquat or acetylphenylhydrazine had no effect. This effect of 6-hydroxydopamine was prevented by either of the hydroxyl radicalscavengers, sodium benzoate and mannitol, but not by the non-scavenger,urea; ninhydrin was partially protected against by mannitol but not by benzoate. Protection against 6-hydroxydopamine was also afforded by D-glucose but not by L-glucose or 3-O-methyl-D-glucose; none of the sugars protected against ninhydrin. In damaging islet beta-cells and in being protected against by D-glucose, 6-hydroxydopamine closely resembles the diabetogenic drug, alloxan. It is suggested ...
Experiments in a homogeneous charge compression ignition (HCCI) engine have been conducted with four gasoline surrogate fuel blends. The pure components in the surrogate fuels consisted of n-heptane, isooctane, toluene, ethanol and diisobutylene and fuel sensitivities (RON-MON) in the fuel blends ranged from two to nine. The operating conditions for the engine were p{sub in}=0.1 and 0.2 MPa, T{sub in}=80 and 250 C, {phi}=0.25 in air and engine speed 1200 rpm. A semidetailed chemical kinetic model (142 species and 672 reactions) for gasoline surrogate fuels, validated against ignition data from experiments conducted in shock tubes for gasoline surrogate fuel blends at 1.0{<=} p{<=}5.0MPa, 700{<=} T{<=}1200 K and {phi}=1.0, was successfully used to qualitatively predict the HCCI experiments using a single zone modeling approach. The fuel blends that had higher fuel sensitivity were more resistant to autoignition for low intake temperature ...
The efficacy of gamma irradiation as a method of decontamination for food and herbal materials is well established. In the present study, Glycyrrhiza glabra roots were irradiated at doses 5, 10, 15, 20 and 25 kGy in a cobalt-60 irradiator. The irradiated and un-irradiated control samples were evaluated for phenolic contents, antimicrobial activities and DPPH scavenging properties. The result of the present study showed that radiation treatment up to 20 kGy does not affect the antifungal and antibacterial activity of the plant. While sample irradiated at 25 kGy does showed changes in the antibacterial activity against some selected pathogens. No significant differences in the phenolic contents were observed for control and samples irradiated at 5, 10 and 15 kGy radiation doses. However, phenolic contents increased in samples treated with 20 and 25 kGy doses. The DPPH scavenging activity significantly (p<0.05) increased in all irradiated ...
Oxidative degradation of methylene blue (MB) by Co^2^+-HCO3^- system with H2O2 in aqueous solution was studied. Nearly complete decolorization of the dye was obtained in less than 50min in diluted NaHCO3 solution (25mM) in the presence of only 20mM Co^2^+ ions. Meanwhile, the conjugated structure and phenyl rings of the MB molecule were destroyed or even broken down into small organic acids and inorganic ions, as indicated by FT-IR spectra and ion-chromatography. Photoluminescence probing and radicalscavenging technologies suggested that the reaction of MB degradation in this system mainly involved the generation and participation of hydroxyl radicals. Furthermore, by cyclovoltammetric measurements, the in situ formed different complexes between Co^2^+ and HCO3^- were observed at differen...
Hyperquenching of liquid water with cooling rates of 10{sup 6}-10{sup 7} K s{sup -1} yields glassy water. Upon {gamma}-irradiation at 77 K, the only paramagnetic species accumulating in hyperquenched glassy water are the hydroxyl and hydroperoxyl radicals. There are no hydrogen atoms or electrons seen by the ESR technique. For irradiation doses up to about 70 kGy, the relative contributions of hydroxyl and hydroperoxyl radicals to the total amount of paramagnetic species remain virtually constant. The total amount of paramagnetic species, n, is sublinear in dose, d, well approximated by n=8.55x10{sup 16}d{sup 0.8} for n in spin g{sup -1} and d in kGy.
SUMMARYA gene eam in Clostridium difficile encodes a protein that is homologous to lysine 2,3-aminomutase (LAM) in many other species but does...Full Text Available
The free radical theory of ageing posits that accrual of oxidative damage underlies the increased cellular, tissue and organ dysfunction and failure associated with advanced age. In support of this...Full Text Available
The degradation of irradiated human insulin in aqueous solutions was investigated in order to protect the protein against ionizing radiation. The influence of the drug concentration, excipients and irradiation temperature were studied.Aqueous solutions at pH 2 were irradiated by gamma rays or by accelerated electrons. Two different high-performance liquid chromatography (HPLC) methods were used: reverse-phase high-performance liquid chromatography (RP-HPLC)/UV and size exclusion liquid chromatography (SEC/UV) to investigate both the fragmentation and the formation of higher molecular weight proteins.In solution without excipients irradiated at ambient temperature at 10kGy, the loss of human insulin is almost complete. Addition of radio-protecting excipients (free radicalsscavengers) and c...
ObjectivesTo assess the influence of epigallocatechin-3-gallate (EGCG) on the efficacy of ionizing radiation on prostate cancer cells because of the increased use of dietary interventions, especially by patients with prostate cancer. Radiotherapy is used to treat localized prostate cancer. Some people consume green tea (EGCG) as a chemopreventive agent against prostate cancer. Green tea can act as an antioxidant and induce superoxide dismutase enzymes, which could scavenge the free oxygen radicals generated by radiotherapy. MethodsProstate cancer cell line DU145 cells were treated with EGCG or radiotherapy, or both. Cell death was assessed using trypan blue cell counting, and apoptosis was confirmed by assessing poly (adenosine phosphate ribose) polymerase cleavage. The antioxidant potenti...
The physical and antioxidant properties of alginate biodegradable film incorporating white, red and extruded white ginseng extracts were investigated. No differences in moisture contents of all alginate film samples were noticeable (p>0.05) except those film samples incorporated without ginseng extract, which had the highest moisture content. The addition of ginseng extract to alginate film decreased tensile strength and elastic modulus (p<0.05) but increased the percent elongation at break. The presence of extracts did not significantly affect the water vapor permeability of the film samples. Alginate film containing extruded white ginseng extract at a barrel temperature of 130degreeC presented the highest (61.12%) free-radicalscavenging activity against the 2,2-diphenyl-1-picryhydrazyl ...
4-Methylcoumarins that possess two hydroxyl groups ortho to each other in the benzenoid ring have shown to have excellent antioxidant and radical-scavenging properties in different experimental models. Furthermore, they cannot be metabolized by the liver P450 monoxygenases and thus cannot form 3,4-coumarin epoxides, which are believed to be mutagenic. Herein, we present a study on the structure activity relationship of eight synthetic 4-methylcoumarins, carried out by employing a series of different chemical cell-free tests. These compounds were tested by means of three assays involving one redox reaction with the oxidant (DPPH assay, ABTS+ assay and FRAP). Other assays were employed to evaluate the antioxidant properties of the coumarins under investigation against NO, O2- and HClO, which...
Abstract Superoxide dismutase (SOD) is ubiquitous in aerobic organisms and constitutes the first link in the enzyme scavenging system of reactive oxygen species. In the present study, species and organ diversity of SOD activity in a solution and in an in-gel assay system, as well as the effects of hydrogen peroxide (H2O2) on SOD activity, were investigated. In a solution assay system, SOD activity of jackfruit root, shoot, leaves, axes, and cotyledons, of maize embryos and endosperms, of mung bean leaves and seeds, of sacred lotus axes and cotyledons, and of rice and wheat leaves was increased by 1-15 mmol/L H2 O2. However, SOD activity in rice root and seeds, maize roots and leaves, mung bean roots and shoots, and wheat seeds was decreased by 1-15 mmol/L H2O2. The SOD activity of wheat ro...
The aim of present study was to evaluate antioxidant property of Glycyrrhiza glabra root extracts using in vitro models. The dose-dependent aqueous and ethanolic extracts demonstrated the scavenging activity against nitric oxide (concentration that caused 50% inhibition of nitric oxide radicals [IC(50)]=72 and 62.1 microg/ml, respectively), superoxide (IC(50)=64.2 and 38.4 microg/ml, respectively), hydroxyl (IC(50)=81.9 and 63 microg/ml, respectively), DPPH (IC(50)=43.6 and 28.3 microg/ml, respectively) and ABTS(*+) (IC(50)=77.3 and 57.2 microg/ml, respectively) radicals. Further, both extracts showed strong reducing power and iron-chelating capacities. In the Fe(2+)/ascorbate system, both extracts were found to inhibit mitochondrial fraction lipid peroxidation. In copper-catalyzed human serum and low-density lipoprotein oxidation models, both extracts significantly (P<0.05) lengthened the lag phase along with a decline ...
The development of detailed chemical kinetic reaction mechanisms for oxidation of n-octane and iso-octane is described, with emphasis on the factors which are specific to many large hydrocarbon fuel molecules. Elements which are of particular importance are found to include site-specific abstraction of H atoms, radical isomerization of alkyl radicals by internal H atom abstraction, and rapid ..beta..-scission of the alkyl radicals. These features, combined with distinctions in the types of intermediate olefin species produced, are used to explain the significant differences in the rate of oxidation between n-octane and iso-octane. Experimental results from the turbulent flow reactor and low pressure laminar flames, using both n-octane and iso-octane as fuels, are used to test the reaction mechanisms and indicate those parts of the total mechanisms which are in greatest need of further development and ...
Pulse radiolysis studies of the formation kinetics and the yields of various phenylcarbenium ions from several different solutes in 1,2-dichloroethane solution have been carried out. The results indicate that there are two kinetically distinguishable cationic species of the solvent which react selectively with the different solutes to form the phenylcarbenium ions. It is suggested that one is a cation radical (yield 0.68 molecule/100 eV) and the other a carbocation (yield 0.20 molecule/100 eV). Rate constants for their separate reactions with selected aromatic compounds and with ammonia have been determined. Molar extinction coefficients have been estimated for benzyl cation, diphenyl cation radical, and anthracene cation radical. 6 figures, 1 table.
Pulse radiolysis studies of the formation kinetics and the yields of various phenylcarbenium ions from several different solutes in 1,2-dichloroethane solution have been carried out. The results indicate that there are two kinetically distinguishable cationic species of the solvent which react selectively with the different solutes to form the phenylcarbenium ions. It is suggested that one is a cation radical (yield 0.68 molecule/100 eV) and the other a carbocation (yield 0.20 molecule/100 eV). Rate constants for their separate reactions with selected aromatic compounds and with ammonia have been determined. Molar extinction coefficients have been estimated for benzyl cation, diphenyl cation radical, and anthracene cation radical. 6 figures, 1 table.
Aqueous deoxyhemoglobin solutions (2 mg/ml) were gamma-irradiated by a "6"0Co source in the presence of methanol, ethanol, 1-butanol and t-butanol under N_2O or argon. The effects of the interaction of the particular alcohol radicalspecies with hemoglobin were determined according to the detected spectral alterations in the visible range. The amounts of stable final products in the form of methemoglobin (MetHb) and the sum of hemichromes and cholehemichromes (Hemichr) were estimated in irradiated preparations. For preparations irradiated under N_2O, the radiation yield for MetHb formation was three-fold lower in the presence of ethanol and 1-butanol [G(MetHb) = 0.33[ compared with preparations irradiated in the presence of t-butanol or without alcohol [G(MetHb) = 1.00[. The yield of hemichromes and cholehemichromes in preparations irradiated under N_2O increased in the order: ethanol (G = 0.38), 1-butanol (B = 0.52), t-butanol (G = 0.59), and ...
Summary The antioxidant properties and toxicity profile of roasted noni (Morinda citrifolia L.) leaf infusion were evaluated. The 2,2-diphenylpicrylhydrazyl (DPPH) radicalscavenging activity was greater than green tea infusion (81.6 +- 0.9% vs. 57.5 +- 1.8%, P < 0.001). The mean quercetin and kaempferol contents of roasted noni leaf infusion, as prepared by the consumer, were 0.24 +- 0.01 and 0.14 +- 0.01 mg mL-1, respectively. Tannic acid content was 10 +- 1 mg mL-1. The infusion was non-mutagenic in the reverse mutation test in Salmonella typhimurium and did not induce primary DNA damage in E. coli PQ37. Further, no significant primary DNA damage was induced by 5,15-dimethylmorindol, which was the only detectable anthraquinone in noni leaves. The infusion was not cytotoxic in the 24 h b...
We quantified the resistance levels of transgenic rice plants, expressing Myxococcus xanthus protoporphyrinogen oxidase (PROTOX) in chloroplasts and mitochondria, to PROTOX inhibitors, acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon. We also determined whether active oxygen species-scavenging enzymes are involved in the resistance mechanism of transgenic rice. The transgenic rice line M4 was about >200-fold more resistant to oxyfluorfen than the wild-type (WT). M4 was also resistant to acifluorfen, carfentrazone-ethyl, and oxadiazon, but did not show multiple resistance to imazapyr and paraquat, which have different target sites. Acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon reduced the chlorophyll content in leaves of WT, but had minimal or no effect on M4. The...
Recent work has shown that natural hydrocarbon emissions can significantly affect the levels of urban and regional tropospheric ozone. We report on the reactivities of these biogenic trace gases, particularly isoprene, focusing on their importance in the production of aldehydes and peroxy radicals, leading to increased levels of hydrogen over regional forests. Hydrogen peroxide can lead to the wet oxidation of sulfur dioxide to acidic sulfate in aerosols, fogs, and clouds. In turn, acidic sulfate can act to as a light scattering aerosol and a source of cloud condensation nuclei (CCN), potentially leading to global cooling. Aerosol sulfate and other dissolved organic and inorganic compounds can also play important roles as a greenhouse species in the lower troposphere.
To elucidate the mechanism of sunlight-induced skin damage, guinea pigs exposed to UV light (280-320 nm, UV B, 4J/cm"2) and a homogenate of the epidermis was examined by means of the thiobarbituric acid (TBA) test. Three hours after the exposure, TBA-malondialdehyde adducts had increased while glutathione reductase activity had decreased, indicating lipid peroxidation. To detect the initial species, spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was applied to a suspension of illuminated epidermal cells (0.5 J/cm"2). An ESR signal obtained only with irradiation comprised a 1 : 2 : 2 : 1 quartet [a (N) =a (#beta#H) =1.49 mT] attributable to a spin adduct of hydroxyl radicals. These results suggest that sunlight exposure of skin may lead to hydroxyl radical generation and simultaneous lipid peroxidation. (author).
Observational evidence is presented for the nucleation of condensation nuclei (CN) in the clear air adjacent to an isolated, marine, cumulus cloud. Two separate regions of particle nucleation are identified: one located above the cloud top, and the second located downwind of the cloud near the level of the anvil outflow. The regions of high CN concentrations were located in extremely clean marine air, with unactivated aerosol surface area (excluding the nucleation mode) less than 2 sq micrometers/cu cm, air temperature -31 C, and higher relative humidities than the undisturbed environment. Vertical profile measurements downwind of the cloud showed that CN concentrations at the level of the anvil outflow (4.9 km) were 8 times greater than at any other level between the surface and 5.3 km. A conceptual model is formulated in which aerosol particles, sulfur dioxide (SO2), sulfuric acid vapor (H2SO4), dimethyl sulfide (DMS), and ozone (O3) from the boundary layer are entrained into the ...
In order to develop modern two-stroke engines with low fuel consumption, respectively with low exhaust emissions, two alternative development areas -- the mixture formation and the scavenging system -- have been correlated. For a satisfying mixture formation without fuel losses by scavenging, the direct injection seems to be one of the best solution for the high speed two-stroke engine of the future. On the other hand the modern development of two-stroke scavenging systems shows a large field of application and improvement methods of cross and loop scavenging. Based on the specific optimization factors of the injection system, respectively of the scavenging system, the aim off this common work of the Universities of Pisa and Zwickau is to correlate both the optimization fields in an advantageous mixture formation process. The principal elements of this correlation are the design of ...
Nitrite was measured in atmospheric liquid phase samples between 1998 and 2005 to investigate the heterogeneous formation of nitrous acid in the lower atmosphere, as well as to assess the quality of water recovered from dew. The samples were collected during ground-based cloud field experiments at different German mountain sites (Brocken, Schmucke, and Hohenpeissenberg) and at a site south of the Bordeaux urban area (France). Concentrations found in Bordeaux dew samples (up to 2800 ?gl-1) are comparable to those found elsewhere in urban fog and dew water and considerably higher than those detected in cloud water or rain. Particulate nitrite (and nitrate) as well as HNO2 (HNO3) data in air masses from a foothill site of Mt. Schmucke, before involved in cloud processing, are also presented. In clouds at Mt. Brocken, both the interstitial HNO2 gas and the aqueous phase nitrite concentration have been measured simultaneous. Significant deviations from Henry's law have been observed, ...
Numerous studies have investigated degradation of individual endocrine disrupting compounds (EDCs) in lab or natural waters. However, natural variations in water matrices and mixtures of EDCs in the environment may confound analysis of the treatment efficiency. Because chemical based analytical methods cannot represent the combined or synergistic activities between water quality parameters and/or the EDC mixtures at environmentally relevant concentrations ({mu}g L{sup -1}-ng L{sup -1}), bioanalytical assessments of residual estrogenic activity in treated water were used to evaluate the performance of the UV based advanced oxidation process for estrogenic contaminants in water. Four EDCs including estradiol (E{sub 2}), ethinyl estradiol (EE{sub 2}), bisphenol-A (BPA) and nonylphenol (NP) were spiked individually or as a mixture at {mu}g L{sup -1}-ng L{sup -1} in laboratory or natural river water. The removal rates of estrogenic activity were quantitatively evaluated by in vitro yeast ...
Since antioxidants have been shown to play a major role in preventing some of the effects of aging and photoaging in skin, it is important to study this phenomenon in a controlled manner. This was accomplished by developing a simple and reliable in vitro technique to assay antioxidant efficacy. Inhibition of peroxidation by antioxidants was used as a measure of relative antioxidant potential. Liposomes, high in polyunsaturated fatty acids (PUFA), were dispersed in buffer and irradiated with ultraviolet (UV) light. Irradiated liposomes exhibited a significantly higher amount of hydroperoxides than liposomes containing antioxidants in a dose- and concentration-dependent manner. Lipid peroxidation was determined spectrophotometrically by an increase in thiobarbituric acid reacting substances. To further substantiate the production of lipid peroxides, gas chromatography was used to measure a decrease in PUFA substrate. In order of decreasing antioxidant effectiveness, the following results ...
The nature of radicals in wood irradiated in vacuum was studied by ESR method. The decay rate of radicals changes in three temperature ranges. Long-lived radicals are very stable at 298"0K, at which the wood-plastics composite has often been studied. The number of radicals formed by irradiations shows fairly good agreement with the total number of radicals in each isolated wood component. The graft copolymerization of MMA to irradiated wood was also studied by means of ESR, and it was found that PMMA propagating radicals are formed in irradiated wood. These radicals are probably formed by the result of graft copolymerization of MMA of wood. (auth.).
A number of amines can be employed for all volatile treatment (AVT) of steam generator (SG) systems of nuclear power reactors. These amines form complexes with Cu{sup 2+} and Ni{sup 2+} ions which come into water due to corrosion. The redox reactions of a number of Cu(II)-AVT amine complexes and the stability of the transient species formed have been studied by pulse radiolysis technique. Rate constants for the reaction of e{sub aq}{sup -} with a number of Cu(II)-amine complexes have been determined by following the decay of e{sub aq}{sup -} absorption. Stability of Cu(I)-amine complexes was studied by following the kinetics of the bleaching signal formed at the {lambda}{sub max} of the Cu(II) amine complex. Except for Cu(I)-triethanolamine complex all other Cu(I)-amine complexes were found to be stable. One-electron oxidation of Cu(II) amine complexes was studied using azidyl radicals for the oxidation reaction as OH ...
Microsecond pulse radiolysis of oxygenated aqueous solutions containing 0.02 mol dm"-"3 sodium formate and 2 mmol dm"-"3 phosphate buffer at pH 7 was used to generate superoxide anion radicals. The influence of some biologically important compounds upon the rate of O_2"."-"b"a"r decay as monitored spectrophotometrically in the range of 245-300 nm. Hematoporphyrin (HP), hemin C (HC), catalase (Cat), cobalt sulfophthalocyanine (CoTSPc) were studied. Among the investigated compounds only Cat was found to show a high catalytic efficiency towards the self-decay of O_2"."-"b"a"r. A red shift of 0_2"."-"b"a"r absorption band and slowing down of its decay were observed to take place by adding HP or CoTSPc to the solutions containing formate ions in excess. This effect is associated with the formation of a transient superoxo-complex. An appearance of an intermediate species with absorption maxima at 350 nm and half-life of about 2 s was observed to ...
A methodology for assessing the impact of subacute concentrations of organometallic agents on bioenergetic and oxidative damage processes in animals, cells and energy transducing subcellular organelles is being developed. Several of the assays are noninvasive and thus lend themselves to human tests. At the whole-animal level we utilize a treadmill chamber where physiological parameters of exercising animals are monitored. These include parameters of whole animals' work performance such as oxygen consumption, carbon dioxide evolution and endurance. Oxidative damage can be monitored in experiments by analyzing expired air of the animals for ethane and n-pentane. These alkanes correlate with lipid peroxidation in vivo. At the cellular and subcellular levels, respiratory activity, lipid peroxidation and free radicalspecies are assayed. Respiratory activity is measured in muscle homogenates and isolated mitochondria using substrates which ...
The transients involved in the reaction of tetracycline (TC) with reducing radicals such as e{sub aq}{sup -}, (CH{sub 3}){sub 2}COH and CO{sub 2}{sup .-}have been characterized by the pulse radiolysis technique. The semi-reduced species formed ({lambda}{sub max} = 630 nm, {epsilon} 3.4 x 10{sup 3} dm{sup 3} mol{sup -1} cm{sup -1}) has been found to be a strong reductant with reduction potential lying in the range -0.450 to -1.40 V vs NHE. TC reacts with e{sub aq}{sup -} at diffusion-controlled rates and the rate constant, depending upon the ionic form of TC existing at a particular pH, varies from 1.2 x 10{sup 10} to 2.8 x 10{sup 10} dm{sup 3} mol{sup -1} s{sup -1}. Based on these results a plausible site of electron addition has been suggested. Reaction of H atoms with TC gives rise to a transient which exhibits spectral and kinetic features different from that of semi-reduced species. (author).
Abstract Male infertility continues to be a clinical challenge of increasing significance. While male factors such as decreased semen quality are responsible for 25% of all infertility issues, the etiology of suboptimal semen quality is poorly understood. Many physiological, environmental, and genetic factors have been implicated, including oxidative stress. Oxidative stress is induced by reactive oxygen species (ROS), or free radicals, and although ROS are required for critical aspects of sperm function, excessive levels of ROS can negatively impact sperm quality. The origin of ROS generation, and the etiologies of increased ROS in men with suboptimal sperm quality have only recently been elucidated, offering multiple targets for potential therapy. Here, we present a critical review of th...
The reactions of tetraphenylphosphonium ion (Ar_4P"+) with esub(aq)"-, H atoms and OH radicals have been investigated. The absorption spectra of three transient species were obtained. Ar_4Psup(.) radicals formed by the reaction: Ar_4P"+ + esub(aq)"- #-># Ar_4Psup(.) have a maximum absorption at 305 nm [epsilon _3_0_5 = (9400 +- 300)dm"3mol"-"1cm"-"1] and decays by second-order kinetics with the rate constant 2k = (2.7 +- 0.4) x 10"9dm"3mol"-"1s"-"1. H atoms and OH radicals form transient adducts to the phenyl groups of the Ar_4P"+ ion with the rate constants of (1.5 +- 0.3) x 10"9 dm"3mol"-"1s"-"1 and (3.0 +- 0.3) x 10"9dm"3mol"-"1s"-"1, respectively. Both adducts have broad absorption spectra at 300 approximately 380 nm (lambdasub(max) = 340 nm) with the molar extinction coefficients epsilonsub(340) = 5400 +- 300 dm"3mol"-"1cm"-"1 for the H adduct and epsilonsub(340) = 3500 +- 200 dm"3mol"-"1cm"-"1 ...
The heterogeneous processing of atmospheric aerosols by reaction with nitrogen oxides results in the formation of particulate and adsorbed nitrates. The water content of these hygroscopic nitrate aerosols and consequently the nitrate ion concentration depend on relative humidity, which can impact the physicochemical properties of these aerosols. This report focuses on the 310 nm photolysis of aqueous sodium and calcium nitrate solutions at pH 4 over a wide concentration range of nitrate ion concentrations representative of atmospheric aerosols. In particular, the quantum yield (phi) of nitrite formation was measured and found to significantly decrease at high concentrations of nitrate for Ca(NO(3))(2). In particular, phi for Ca(NO(3))(2) was found to have a maximum value of (7.8 +/- 0.1) x 10(-3) for nitrate ion solution concentrations near one molal, with the smallest quantum yield for the highest concentration solution above 14 m nitrate ion, phi = (2.3 +/- 2.0) x 10(-4). The effect ...
A vast amount of circumstantial evidence implicates oxygen-derived free radicals (especially, superoxide and hydroxyl radical) and high-energy oxidants [such as peroxynitrite (OONO−)]...Full Text Available
Comparisons have been made between Buddhism and the philosophy of science in general, but there have been only a few attempts to draw comparisons directly with the philosophy of radical behaviorism....Full Text Available
The authors present some recent measurements on electroweak physics using data collected by the CDF experiment at the Tevatron proton anti-proton collider ({radical}s = 1.96 TeV) at Fermilab.
A method for the quantitative determination of atmospheric hydroperoxyl radical comprising: (a) contacting a liquid phase atmospheric sample with a chemiluminescent compound which luminesces on contact with hydroperoxyl radical; (b) determining luminescence intensity from the liquid phase atmospheric sample; and (c) comparing said luminescence intensity from the liquid phase atmospheric sample to a standard luminescence intensity for hydroperoxyl radical. An apparatus for automating the method is also included.
Phospholipid vesicles were found to be lysed by exposure to free radicals derived from irradiated glycine and galactose. The decomposition yield increased with vesicle concentration, and attained values of 0.0006 vesicles destroyed per radical added. Ionic charge at the phospholipid end groups was found to be more important than degree of unsaturation in determining this yield. Radicals derived from irradiated serine and alanine had no detectable lytic action at the vesicle concentrations tested.
Experimental investigation data are systematized of free radical states and processes in irradiated proteins. The investigation is performed by the radiospectral methods. Results are discussed in detail of the study of free radicals electronic structure of amino acids, peptides and proteins formed by the action of ionizing radiation. The specificity is stressed of the study of monocrystalls of these compounds by the method of electronic paramagnetic resonance. The nature is also studied of primary centres formed under the effect of radiation on biologically important compounds and their subsequent reactions in solid and liquid solutions. Ion-radical states of different functional groups of the protein molecule are studied. Prospects of the study and the role of anion-radicals in biological processes are discusses.
Spectra of e.p.r. radicals in cellulose and timber gamma-irradiated at 77 and 300 K have been measured. Radiation yields and the kinetics of radicals accumulation have been studied. The effect of ionizing radiation on cellulose is the appearance of radicals resulting from rupture of C-H bonds in positions 1 and 4. Timber, additionally, forms ''lignin'' radicals. A mechanism of cellulose and timber radiolysis is suggested. ''Lignin''-type compounds present in timber protect polysaccharides from radiation-induced destruction.
In this thesis the rate constants for a number of radical reactions in aqueous solution have been studied in a wide temperature range. The reactions of H with H_2O_2, OH and HO_2 and the reactions of HO_2 with OH, Fe"2"+ and Cu"2"+ have been studied. For each reaction rate constants have been determined as a function of temperature using the technique of high temperature, high pressure (HTP) pulse radiolysis. The rate constants were obtained by fitting a kinetic computer model to the experimental data. From an Arrhenius plot the activation energy of each reaction was determined. The data determined in this way are important for modeling of radiolysis in nuclear light water reactors. A previously developed model for calculation of the effect of water radiolysis products on oxidation and dissolution of spent nuclear fuel has been improved. In the new model, called TraRaMo, simultaneous transport by diffusion and chemical reactions induced by radiolysis can be ...
The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an {sup 55}Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of ...
The role of intermediate products of dioxygen reduction in cytotoxic effects ascribed to oxygen molecules was studied in vivo using various yeast mutants with changed response to oxygen stress. It has been documented that superoxide radical exerts its deleterious effects on yeast cells directly and the role of other oxygen species derived from it is hardly detectable. Yeast Saccharomyces cerevisiae, however, cannot be considered as a typical eukaryotic organism due to its inability of synthesizing polyunsaturated fatty acids (pufa). These fatty acids are known as main target molecules during oxidative stress and their peroxidation leads to cytotoxic effects. As fatty acid content could be easily manipulated in yeast, this organism was used to evaluate the contribution of pufa peroxidation process to the cytotoxic effects of oxygen. Results obtained show, that yeast cells containing linolenic acid as the main constituent of phospholipids are ...
Electron paramagnetic resonance (EPR) of coals was considered by using iodine doping technique. Sub-bituminous coal (WA) and bituminous coal (UF) were used to observe EPR spectra using microwaves. With the UF coal, strength of the narrow component of the spectra was found constant regardless of amount of the doped iodine, wherein radicals without interaction with iodine were detected. Strength of the broad component increased with the iodine doping amount, where in deviation of {pi} electrons was detected, which have been generated as a result of interaction between aromatic rings and iodine in the coals. Spin concentration of the WA coal with low coalification degree is constant regardless of the iodine doping amount, and the interaction of the iodine with the aromatic rings was found small. The higher the coalification degree, the more the aromatic ring structure grows, and electron donor capability for the iodine increases. In a system with the entire spin being ...
The rate coefficients for the reactions of OH radical with CH3Br and CH2Br2 were measured as functions of temperature using the laser photolysis - laser induced fluorescence method. This data was incorporated into a semiempirical model (Solomon et al., 1992) and a 2D model to calculate the steady-state ozone depletion potentials (ODP) and atmospheri lifetimes, tau, with greatly improved accuracy as compared to earlier studies. The calculated ODPs and tau are 0.65 and 1.7 years and 0.17 and 0.41 years for CH3Br and CH2Br2, respectively, using the semiempirical model. These lifetimes agree well with those calculated using a 2D model. This study better quantifies the ODPs and tau of these species which are needed inputs for discussion of possible regulation of human emissions currently under international considerations. 29 refs.
Though central to our understanding of how roots perform their vital function of scavenging water and solutes from the soil, no direct genetic evidence currently exists to support the foundational model...Full Text Available
Red cell transfusions are associated with the development of acute lung injury in the critically ill. Recent evidence suggests that storage induced alterations of the red blood cell (RBC) collectively...Full Text Available
Exteriorized phosphatidylserine (PS) residues in apoptotic cells trigger rapid phagocytosis by macrophage scavenger receptor pathways. Mimicking apoptosis with liposomes containing PS may represent...Full Text Available
B lymphocytes can function independently as efficient APCs. However, our previous studies demonstrate that both dendritic cells and macrophages are necessary to propagate immune responses initiated...Full Text Available
Cd36 is a small-molecular-weight integral membrane protein expressed in a diverse, but select, range of cell types. It has an equally diverse range of ligands and physiological functions, which has...Full Text Available
Measurements were completed on the solubility of cupric and cuprous oxides in liquid water and steam at controlled pH conditions from 25 to 400 C (77 to 752 F). The results of this study have been combined with those reported from this laboratory in two previous EPRI reports to provide a complete description of the solubility of these oxides and the speciation of copper dissolved in liquid water and steam as a function of oxidation state, temperature, pH, and in the case of steam, pressure. These constitute the first set of reliable data for cuprous oxide solubility over this range of conditions. For the more intensively studied CuO case, agreement was found between our results and those of previous studies of its solubility in steam, whereas only partial agreement was evident for its solubility in liquid water. For both oxides this disagreement often amounted to orders of magnitude. The solubility of cuprous oxide is somewhat lower than that of CuO at ambient conditions, except as ...
The radical cations from aziridine and azetidine have been characterized by ESR spectroscopy following their generation in the solid state by #gamma# irradiation of dilute solutions of the parent compounds in the CFCl_3 matrix at 77 K. The ESR parameters of the azetidine radical cation are typical of those for nitrogen-centered amine radical cations such as Me_2NH*"+. On the other hand, the radical cation formed from aziridine has very different ESR parameters that compare closely to those for the isoelectronic C...C ring-opened form of the oxirane radical cation and the allyl radical. The radical cation formed from azetidine is therefore assigned a ring-closed structure with the unpaired electron in a 2p/sub z/ orbital on nitrogen perpendicular to the ring plane, whereas the cation from aziridine is an allylic C...C ring-opened planar ...
The radical cations from aziridine and azetidine have been characterized by ESR spectroscopy following their generation in the solid state by ..gamma.. irradiation of dilute solutions of the parent compounds in the CFCl/sub 3/ matrix at 77 K. The ESR parameters of the azetidine radical cation are typical of those for nitrogen-centered amine radical cations such as Me/sub 2/NH*/sup +/. On the other hand, the radical cation formed from aziridine has very different ESR parameters that compare closely to those for the isoelectronic C...C ring-opened form of the oxirane radical cation and the allyl radical. The radical cation formed from azetidine is therefore assigned a ring-closed structure with the unpaired electron in a 2p/sub z/ orbital on nitrogen perpendicular to the ring plane, whereas the cation from aziridine is an allylic C...C ...
Objective. Cervical cancer patients who had an abandoned radical hysterectomy were evaluated for preoperative clinical predictors, complication rates, and outcomes. Study...Full Text Available
The OH-initiated photo-oxidation of n-butane was used as a source of 1- and 2-butoxy radicals. Reactions producing ketones and other organic compounds are explained. Rates of photolysis were determined and are discussed.
PurposeThe objective of this study is to evaluate the continence rate following reconstruction of the posterior urethral plate in robot-assisted laparoscopic radical prostatectomy...Full Text Available
Free radical formation has been implicated in the toxicity of a wide range of xenobiotics. In recent years, particular interest has been paid to compounds which can undergo a one electron reduction...Full Text Available
Introduction:Although radical prostatectomy (RP) is an effective treatment for prostate cancer, it has potentially deleterious effects on health-related quality of life (HRQoL)....Full Text Available
Despite being free of charge, treatment adherence to 7-day primaquine for the radical cure of Plasmodium vivax was estimated at 62.2% among patients along the Iquitos-Nauta road in...Full Text Available
We have undertaken a program which measures the photoelectron spectra of negative-ion beams. This experiment has afforded us direct information about these ions and the corresponding neutral radicals. Several ions and numerous radicals are believed to be crucial intermediates in combustion processes and flame chemistry. We have fabricated a spectrometer which directly measures electron affinities (EA). Knowledge of the EA and gas-phase acidity of a radical has enabled us to deduce several radical heats of formation and bond strengths.
Radicals formed in gamma-irradiated crystals of galactose and glycine were found, upon dissolution, to cause mutagenesis of Salmonella typhimurium strains TA-98 and TA-100. Although the reproducibility of the results has not been adequately determined, they suggest the possibility of developing a test to measure the mutagenic-carcinogenic potential of radiation-induced free radicals with a microbial system.
... Three prototype reactors were constructed and the photocatalysts used were TiO2 for hydroxyl radical generation, dyes such as methylene blue and rose bengal for singlet oxygen generation, and ferric chloride/hydrogen peroxide in Photo-Fenton OH radical generation. Singlet oxygen was effective against some of the pesticides but reacted slowly or not at all with others. All pesticides were degraded by OH radical generating agents (such as methylene blue)...
The work presented here demonstrates the ability of proton-transfer-reaction mass spectrometry (PTR-MS) to perform fast-response measurements of volatile organic compounds (VOCs) (including methanol, acetonitrile, acetaldehyde, acetone, PAN-type compounds, alpha- and beta-pinene, nopinone and pinonaldehyde) at the pptv level and its versatile applicability in the field of environmental trace gas analysis. Laboratory and field experiments including various calibration techniques and intercomparisons with other measurement techniques such as gas chromatography, atmospheric pressure chemical ionization and Fourier transformation infrared spectroscopy were performed providing a first characterization of the PTR-MS instrument performance (sensitivity, detection limit, precision, accuracy). Typically a detection limit (S/N=2) of 50 pptv for a 10 s signal integration time, a precision of 5 % and an accuracy in the range between 10 and 25 % were observed. Due to its compactness and ruggedness ...
One important market related capability for firms which seek to develop radical innovations is the competence to involve the 'right' users at the 'right' time in the 'right' form. While former studies have identified a rather passive role of users in the radical innovation process, this paper focuses on the involvement of such users that are in the position to play an active role as inventors and (co)-developers. A multiple case study analysis was conducted in the field of medical technology. Five radical innovation projects within four firms were selected including medical robots and computer-assisted navigation systems. The case study analysis reveals that firms who closely interact with specific users benefit significantly for their radical innovation work. These users have a high motivation toward new solutions, are open to new technologies, possess diverse competencies, and are embedded into a very ...
Abstract Acid-treated cobia (Rachycentron canadum) skin was extracted in a retort (121C) to obtain retorted skin gelatin hydrolysates (RSGHs) containing antioxidant peptides with noticeable antioxidant properties. To improve the antioxidant activity of cobia RSGHs, five processing factors including alkali concentration, alkali pretreatment time, phosphoric acid concentration (PC), water/skin ratio (WS) and retorting time (RT) in RSGH production were screened using a fractional factorial design to identify critical factors. It indicated that PC, WS and RT had significant effects on ,-diphenyl--picrylhydrazyl (DPPH) scavenging by RSGHs. Subsequently, the optimization of PC, WS and RT on the DPPH scavenging of RSGHs was studied using a central composite design to collect data that resulted in...
Radical cations of various 3-methylalkanes (C_6-C_1_4) have been produced and stabilized by #gamma#-irradiation of the corresponding neutral compounds in saturated chlorofluorocarbon and perfluorocarbon matrices at 77 K. The perfluorocarbon matrices appeared more suitable for studies of the lighter radical cations, whereas the chlorofluorocarbon matrices were more suited for studies of the heavier radical cations; intermediary cations could be studied in both types of matrices. After irradiation, electronic absorptions associated with both the matrix and the alkane additive were observed. Pure spectra of the 3-methylalkane radical cations were obtained by difference spectrometry, after selective elimination of these cations by illumination. The electronic absorption spectra of the 3-methylalkane radical cations consist in all cases of a single broad absorption band. The spectral ...
BackgroundThe study of bacterial species interactions in a mixed-species community can be facilitated by transcriptome analysis of one species in the community using cDNA microarray...Full Text Available
PWR primary circuit radiolysis model describes oxygen/hydrogen behavior in the Westinghouse Sizewell B 4-loop PWR (SNUPPS design). The effect of oxygen ingress have also been evaluated using the same model. There is clear agreement from experimental and modelling data that the dissolved hydrogen concentration required to suppress radiolysis decreases as the temperature increases. There is good evidence from the study at the Belleville PWR that {approx}5 cc(STP)kg{sup -1} H{sub 2} is sufficient to suppress radiolysis during power operation. Modelling indicates that the minimum hydrogen concentration is about 0.5 cc (STP)kg{sup -1} at PWR operating temperatures and that the presence of boric acid has little effect on this value, although it does increase the steady-state concentration of H{sub 2}O{sub 2}. Downstream of the core the concentrations of both oxygen and hydrogen peroxide fall by about two orders of magnitude at full power due to reaction with radicals ...
Carbonyl compounds constitute an important reactive class of non methane volatile organic compounds. They can be emitted directly to the atmosphere from primary sources such as combustion engines, landfills and wastewater surfaces or as secondary products by the photochemical oxidation of hydrocarbons and other volatile organic compounds 1-3. Carbonyls photo-oxidize during the day to produce toxic radicals such as OH, HO_2, RO and RO_2. These species react with nitrogen oxides (NOx) and other VOCs present in the atmosphere to form tropospheric ozone (O_3); a highly reactive oxidizing agent that is harmful to human health, agricultural products and climate 4, 5. Hence identifying the levels and sources of ozone precursors such as low carbonyls, carbon monoxide (CO) and NOx derivatives, and understanding their physical and chemical transformation in the troposphere is an important task due to their atmospheric and adverse health implications. ...
Fully fluorinated compounds (perfluoro compounds) represent a class of chemicals which include many extremely inert species-inert to both chemical reaction and photodissociation. Well known examples include SF6 and the perfluorocarbons (PFCs) CF_4 and Teflon. SF_6 is used industrially in electrical switch gear and as an atmospheric tracer. CF_4 and C_2F_6 are released into the atmosphere as a by-product of aluminum manufacture. Several perfluoro compounds have been proposed as substitutes for the ozone-destroying Freons and halons; proposed substitutes include SF_6, c-C_4F_8, C_5F_1_2, and C_6F_1_4. These chemicals were chosen in part because they do not harm the stratospheric ozone layer and were therefore considered environmentally friendly. Recently, Ravishankara et al. reported that perfluoro compounds have significant global warming potential (GWP), contributing to the greenhouse effect due to strong infrared absorption. The perfluoro compounds have ...
Decay mechanism of H{sub 2}{sup -} anions produced by {gamma}-ray or X-ray radiolysis of solid para-H{sub 2} (p-H{sub 2}) has been studied using high-resolution ESR spectroscopy in the temperature range between 2.7-6.6 K. The results can be summarized as follows; First, the decay rate constant of the H{sub 2}{sup -} anion is not proportional to initial yields of reactive species such as H radical and cation but proportional to concentrations of HD and D{sub 2} impurities in p-H{sub 2}. Second, ESR spectra assigned as electron bubbles were observed in solid p-H{sub 2} containing large amount of HD or D{sub 2} (11 mol %), while they were not observed in pure solid p-H{sub 2}. Third, the decay rate constant of the H{sub 2}{sup -} anion increases with the decrease in temperature between 2.7-5 K, while it decreases with the decrease between 5-6.6 K. Fourth, the decay of the H{sub 2}{sup -} anion is suppressed by addition of ortho-H{sub 2} (o-H{sub ...
Benzene molecules , present in the proto-planetary nebula CRL 618, are ionized and dissociated by ultraviolet (UV) and X-ray photons originated from the hot central star and by its fast wind. Ionic species and free radicals produced by these processes can lead to the formation of new organic molecules. The aim of this work is to study the photoionization and photodissociation processes of the benzene molecule, using synchrotron radiation and time-of-flight mass spectrometry. Mass spectra were recorded at different energies corresponding to the vacuum UV (21.21 eV) and soft X-ray (282-310 eV) spectral regions. The production of ions from the benzene dissociative photoionization is here quantified, indicating that C_6H_6 is more efficiently fragmented by soft X-ray than UV radiation, where 50% of the ionized benzene molecules survive to UV dissociation while only about 4% resist to C-rays. Partial ion yields of H and small hydrocarbons, such as ...
The mechanism for afterglow suppression in codoped CsI:Tl,Eu reported in the preceding paper was investigated by combined radioluminescence and thermoluminescence experiments. Model rate equations informed by these experiments were employed to simulate afterglow. It was found that codoping with europium introduces deep electron traps, with room-temperature glow peaks, that effectively scavenge the electrons from shallow traps associated with thallium, thus suppressing afterglow in the time domain of tens of milliseconds.
Effects of gamma irradiation on the physiological effectiveness of Korean medicinal herbs were investigated. The physiological effectiveness including antioxidant and anticomplement function, nitrite scavenging and electron donating ability of Korean medicinal herbs by gamma irradiation at 10 kGy did not differ from that of the nonirradiated control.
In relation to coal liquefaction reaction, the effect of the coexistence of transferable hydrogen (TH) from process solvent on reduction of radical concentration and the effect of pre-heat treatment on average structure of coals were studied. In experiment, change in radical concentration with temperature rise was measured using the system composed of Yallourn coal and process solvent. The results are as follows. Process solvent with a wide boiling point range of 180-420{degree}C is effective in suppressing an increase in radical concentration even at higher temperature. The effect of hydrogen-donating solvent increases with TH. It was also suggested that high-boiling point constituents in solvent stabilize radicals even over 400{degree}C by vapor phase hydrogenation. The experimental results of pre-heat treatment are as follows. Although the conversion improvement effect of TH is equivalent to that of ...
The mono- and intramolecular cation-radicals (CR) reactions of diethylmercury in the CFCl_3, CFCl_2CF_2Cl matrices and CF_2BrCF_2Br and CFCl_3 freons vitrified mixture (1:1) were studied through the EPR method. Formation of radical products of transformations of the initial CR diethylmercury (X-ray radiation dose - 100-200 Gy at the temperature of 293 K) was studied through the spin trap of 2.4.6 - tri-tret-butylnitrosebenzene.
The kinetics of HO{sub 2} radicals in UV-irradiated frozen dilute solutions of H{sub 2}O{sub 2} were followed by the ESR technique. Radical disproportionations at the irradiation temperature were found to be adequately described in terms of dispersive kinetics by a second-order equal-concentration kinetic equation with rate parameters changing non-monotonically in the temperature range 100-200 K. These changes are thought to occur due to well separated structural relaxation regions of polycrystalline ice in the above temperature range. (author).
PurposeTo conduct a retrospective analysis within a large university teaching hospital, comparing outcomes between patients receiving either radical surgery or radiotherapy as curative treatment for bladder cancer.Patients and MethodsBetween March 1996 and December 2000, 169 patients were treated radically for muscle-invasive bladder cancer. Data were collected from patient notes. Statistical analyses were performed using Kaplan-Meier methods and Cox proportional hazards regression analysis to compare radiotherapy and surgical outcome data.ResultsThere was no difference in overall, cause-specific, and distant recurrence-free survival at 5 years between the two groups, despite the radiotherapy group being older (median age, 75.3 years vs. 68.2 years). There were 31 local bladder recurrences...
ROBOT-ASSISTED RADICAL LAPAROSCOPIC PROSTATECTOMY WAKE FOREST UNIVERSITY BAPTIST MEDICAL CENTER WINSTON-SALEM, NC 00:00:08 ANTHONY ATALA, MD: I would like ...
Penile rehabilitation therapy following radical prostatectomy is a much debated topic. Erectile dysfunction is still a significant contributor to postoperative morbidity following radical prostatectomy, despite meticulous nerve-sparing technique. Secondary smooth muscle changes in the penis have been identified as the underlying causes of penile atrophy, veno-occlusive dysfunction, and fibrosis. Initial observations that intracavernous injection therapies used on a regular basis postoperatively resulted in improvements in the return of spontaneous erectile function led to the development of penile rehabilitation protocols. Chronic dosing of PDE-V inhibitors is now commonly used by urologists after radical prostatectomy. Despite the current enthusiasm of penile rehabilitation therapy, current scientific evidence with clinical trials is still limited. PMID:19255627
The Mitochondrial Free Radical Theory of Aging (MFRTA) is currently one of the most widely accepted theories used to explain aging....Full Text Available
Pulsed radiolysis method is used to study transformations intermediates of 6-aminophenalenone in ethanol. In alkaline medium the main product is radical-anion of 6-aminophenalenone, which optical absorption spectrum contains two bands with maxima at 355 and 400 nm. The particle precursors are e_s, CH_3CHOH and CH_3CHO"- radicals. In neutral and acid medium radical-anions are protonated in reactions with alcohol and hydrogen ions. The resulting H-adduct of 6-aminophenalenone has optical absorption maxima at 350 and 390 nm. Availability of two maxima is related to two various product structures. Molar extinction coefficients of radical-anions and H-adducts of 6-aminophenalenone and rate constants of reactions with their participation are estimated.
Intermediate products of the conversions of 6-aminophenalenone in ethanol were investigated by pulse radiolysis. In alkaline medium the main product is the 6-aminophenalenone radical cation, the optical absorption spectrum of which contains two bands with maxima at 355 and 400 nm. The precursors of this particle are e_s, CH_3CHOH and CH_3CHO"- radicals. In neutral and acid medium, radical cations are protonated in reactions with alcohol and hydrogen ions. The H-adduct of 6-aminophenalenone that arises has optical absorption maxima at 350 and 390 nm. The presence of two maxima is due to two different structures of the product. The molar extinction coefficients of the radical anions and H-adducts of 6-aminophenalenone and the rate constants of the reactions involving them were estimated. 6 refs., 4 figs., 2 tabs.
The n3 and n4 vibrational transitions of CH3 and CD3 isolated in solid parahydrogen were studied by high-resolution infrared spectroscopy. The radicals were produced by in situ UV photolysis of methyl iodides trapped in solid parahydrogen. The observed spectra showed clear rotational fine structures, which were subjected to further splitting due to the electrostatic field of solid parahydrogen. The molecular constants and crystal field parameters of the radicals in solid parahydrogen were determined by analyzing the spectral structures of the n3 and n4 transitions of CD3 by the crystal field theory. The rotational constants of the CD3 radical were found to be only a few percent smaller than those in the gas phase. The determined crystal field parameters indicated significant quantum effect...
There are several methods of generating OH free radicals from ozone and/or hydrogen peroxide and ultraviolet light. They all have in common that the OH free radicals originate in one single source only whereas in the combination of ozone with ionizing radiation two simultaneous working sources for the OH free radicals exist. The resulting higher OH free radical concentration makes this process especially apt for the remediation of low level contaminated groundwater as for example trichloroethylene (TCE) contamination in the sub-ppm range. A cost comparison between O_3/UV and O_3/electron beam for remediation of a groundwater contaminated with 100 ppb TCE indicated that for a throughput of about 5 million gallons/day the O_3/electron beam process is more cost-effective. (authors).
of Concern; Parks; Management; Monitoring Exotic and Invasive Species Northern Arizona University. Canyons, Cultures, and Environmental Change. Species of Concern; Contacts;...
In recent years, Clostridium species have rapidly reemerged as human and animal pathogens. The detection and identification of pathogenic Clostridium species...Full Text Available
Decomposition yields of tetracycline sulphate and oxytetracycline sulphate were determined in argon saturated 0.1N H/sub 2/SO/sub 4/ solutions. The decomposition yields of teracyclines decrease in the presence of the Cl/sup -/ ions. The reaction rate constants of the OH radicals with tetracyclines were also determined.
Esters of dihydric alcohols with alkenylphosphonic or alkenylphosphinic acids which are polymerizable by free radicals are described. They are combined with polymer binders, in particular water-soluble polymers, and photoinitiators forming free radicals to give photopolymerizable mixtures which are suitable for the production of photoresists and printing plates. The mixtures display low heat-sensitivity and have long shelf lives. (author) 1 tab.
Practical procedures were developed for large-scale microbial decontamination of dry egg powder and gelatine with gamma radiation ("6"0Co). The formation and lifes of free organic radicals in these materials were examined by ESR measurements of powder samples. The concentration of these radicals was studied in dependence on the time of storage. Secondary oxidation of egg fats by air oxygen was investigated. Sensoric tests of irradiated gelatine, both in powder and hydrogel form, were performed. (author). 4 figs., 2 tabs., 2 refs.
The author is exploring the efficiency of pulsed plasma processing in the removal of nitrogen dioxide, nitrogen oxide, and other pollutants. This process uses an electrical discharge to create chemical radicals from air molecules. These radicals can react with pollutants and form harmless compounds. Additives such as hydrocarbons are also used to improve the efficiency of the removal. The efficient removal of nitrogen dioxide has required the presence of dilute aqueous solution of ammonia.
The high-energy radiation-induced degradation of an H-acid derivative azo dye, Apollofix-Red SF-28 (AR-28) was studied in aqueous solution by using pulse radiolysis with kinetic spectroscopic detection for transient measurements. Gamma radiolysis with UV-VIS spectroscopy and gradient ionpair HPLC separation with diode array detection were applied for following the destruction of AR-28 and measuring the products. The reactions of hydrated electron (e_a_q "-) and hydroxyl ("#centre dot#OH) radical were investigated separately. "#centre dot#OH reacts with the unsaturated bonds of the molecule. In the further reactions of the "#centre dot#OH adduct radicals, the AR-28 molecules partly reform with a slightly modified structure. The products formed in the first reaction of "#centre dot#OH and AR-28 molecules have also high reactivity towards the "#centre dot#OH radicals. For these reasons the efficiency of "#centre dot#OH ...
Invasive species pose serious threats to community structure and ecosystem function worldwide. The impacts of invasive species can be more pervasive than simple reduction of species numbers. By using...Full Text Available
Method for determining the concentration of atomic species in gases and solids. Measurement of at least two emission intensities from a species in a plasma containing the species after a sufficient time period has elapsed after the generation of the plasma and during a second time period, permits an instantaneous temperature to be established within the sample. The concentration of the atomic species to be determined is then derived from the known emission intensity of a predetermined concentration of that species in the sample at the measured temperature, a quantity which is measured prior to the determination of the unknown concentration, and the actual measured emission from the unknown species, or by this latter emission and the emission intensity of a species having known concentration within the sample.
The radiation reduction of bis(1-ethylimidazole)tartratoplatinum(II) (EITPt(II)) complexes in methanol-water solution have been examined. The yields of Pt(I) depend on the presence of O{sub 2} in solutions as well as the dose applied. The rate constants of e{sub s}{sup -} scavenging by EITPt(II) and cis(diammine-1,1-cyclobutanedicarboxylato) platinum(II) (CBDCAPt(II)) have been determined by pulse radiolysis to be equal to 5.4 x 10{sup 9} and 6.4 x 10{sup 9} M{sup -1} s{sup -1}, respectively. The efficiencies of e{sub t}{sup -} scavenging by EITPt(II) and the rate of e{sub t}{sup -} photobleaching have also been determined in LiCl : H{sub 2}O : CH{sub 3}OH and MgCl{sub 2} : H{sub 2}O : CH{sub 3}OH glasses, respectively. (author).
Ternary copper(II) complexes [Cu(L1)B](ClO4) (1, 2) and [Cu(L2)B](ClO4) (3, 4), where HL1 and HL2 are tridentate NSO- and ONO-donor Schiff bases and B is a heterocyclic base, viz. dipyrido[3,2-d:2',3'-f]quinoxaline (dpq, 1 and 3) or dipyrido[3,2-a:2',3'-c]phenazine (dppz, 2 and 4), were prepared and their DNA binding and photoinduced DNA cleavage activity studied. Complex 1, structurally characterized by single-crystal X-ray crystallography, shows an axially elongated square-pyramidal (4 + 1) coordination geometry in which the monoanionic L1 binds at the equatorial plane. The NN-donor dpq ligand exhibits an axial-equatorial binding mode. The complexes display good binding propensity to calf thymus DNA, giving a relative order 2 (NSO-dppz) > 4 (ONO-dppz) > 1 (NSO-dpq) > 3 (ONO-dpq). They cleave supercoiled pUC19 DNA to its nicked circular form when treated with 3-mercaptopropionic acid (MPA) by formation of hydroxyl radicals as the cleavage active ...
One-electron reduction of the square-planar nickel precursor (PNP)NiCl ( 1) (PNP (-) = N[2-P(CHMe 2) 2-4-methylphenyl] 2) with KC 8 effects ligand reorganization of the pincer ligand to assemble a Ni(I) dimer, [Ni(mu 2-PNP)] 2 ( 2), containing a Ni 2N 2 core structure, as inferred by its solid-state X-ray structure. Solution magnetization measurements are consistent with a paramagnetic Ni(I) system likely undergoing a monomer dimer equilibrium. The room-temperature and 4 K solid-state X-band electron paramagnetic resonance (EPR) spectra display anisotropic signals. Low-temperature solid-state X-band EPR data at 4 K reveal rhombic values g z = 1.980(4), g x = 2. 380(4), and g y = 2.225(4), as well as a forbidden signal at g = 4.24 for the Delta M S = 2 half field transition, in accord with 2 having two weakly interacting metal centers. Utilizing an S = 1 model, full spin Hamiltonian simulation of the low-temperature EPR spectrum on the solid sample was achieved by applying a nonzero ...
For better understanding and proper use of organic chemicals addition data are needed, including kinetic data on the scavenging reactions in actual cycles, data on ambient temperature stability and decomposition, sampling and analsyis information, data on effects in a case of fire, and more corrosion data. Use of these chemicals for layup of boilers and other equipment needs to be evaluated for each application. After a preliminary evaluation, such as outlined in this report, every new water treatment chemical should be evaluated in at least two month test in actual steam cycle. (orig.).
Conduction-band electrons, formed by pulse radiolysis of Degussa P25 TiO_2 particles, have been monitored by time-resolved microwave conductivity and found to undergo equilibrium localization and eventual recombination at the particle surface. In the presence of isopropyl alcohol recombination is retarded due to surface hole scavenging. The particle bulk can then be pumped with mobile electrons, which survive for seconds.
Insect host/parasitoid interactions are co-evolved systems in which host defenses are balanced by parasitoid mechanisms to disable or hide from host immune effectors. Although there is a rich literature on these systems, parasitoid immune-disabling mechanisms have not been fully elucidated. Here we report on a newly discovered immune-disabling mechanism in the Pieris rapae/Pteromalus puparum host/parasitoid system. Because venom injections and parasitization suppresses host phagocytosis, we turned attention to the P. rapae scavenger receptor (Pr-SR), posing the hypothesis that P. puparum venom suppresses expression of the host Pr-SR gene. To test our hypothesis, we cloned a full-length cDNA of the Pr-SR. Multiple sequences alignment showed the deduced amino acid sequence of Pr-SR is similar to scavenger receptors of other lepidopterans. Bacterial and bead injections induced Pr-SR mRNA and protein expression, which peaked at 4h post-bead ...
Quivers (directed graphs) and species (a generalization of quivers) and their representations play a key role in many areas of mathematics including combinatorics, geometry, and algebra. Their importance is especially apparent in their applications to the representation theory of associative algebras, Lie algebras, and quantum groups. In this paper, we discuss the most important results in the representation theory of species, such as Dlab and Ringel's extension of Gabriel's theorem, which classifies all species of finite and tame representation type. We also explain the link between species and K-species (where K is a field). Namely, we show that the category of K-species can be viewed as a subcategory of the category of species. Furthermore, we prove two results about the structure of the tensor ring of a species ...
Kinetics of postradiation polymerization of triethylene glycol ..cap alpha.., ..omega..-dimethacrylate has been studied by calorimetric method. The low-temperature radiolysis has been studied by ESR method. The radiation-chemical yield of radicals on ..gamma..-irradiation by /sup 60/Co is determined being equal to 6+-1 1/100 ev. Transformation of the radicals spectrum into the spectrum of propagating macroradicals proceeds at 140 K. After the transition from glassy to liquid state (Tsub(g)=193 K) the intensive postpolymerization begins. During the polymerization the disappearance of radicals is observed. For the low-temperature region the effective activation energy of polymerization is determined beina equal to 50.7+-0.8 kJ/mol.
The effects of TANOL radical have been examined on chemical shifts and relaxation rates of /sup 109/Ag NMR in aqueous solution of silver salts. The silver ion in aqueous solution is found to coordinate with TANOL radical. A small amount of TANOL is added as a doping agent(0.020M), since /sup 109/Ag signals are obtained for (1.0M) silver ion within 30 minutes. The /sup 109/Ag chemical shifts of silver salt in aqueous solutions were found within the range of 0 to -1000 ppm relative to that of 1.0M AgNo/sub 3/.
Exercise training is known to induce an increase in free radical production potentially leading to enhanced muscle injury. Vitamins C and E are well known antioxidants that may prevent muscle cell damage....Full Text Available
Exposure of albumin to Cu(II) (10-100 microM) and ascorbate (0.1-2 mM) results in extensive molecular modifications, indicated by decreased fluorescence and chain breaks. The rate of utilization of...Full Text Available
The authors report on a search for pair production of first-generation scalar leptoquarks (LQ) in p{bar p} collisions at {radical}s = 1.96 TeV using an integrated luminosity of 252 pb{sup -1} collected at the Fermilab Tevatron collider by the D0 detector. They observe no evidence for LQ production in the topologies arising from LQ{ovr LQ} {yields} eqeq and LQ{ovr LQ} {yields} eqvq, and derive 95% C.L. lower limits on the LQ mass as a function of {beta}, where {beta} is the branching fraction for LQ {yields} eq. The limits are 241 and 218 GeV/c{sup 2} for {beta} = 1 and 0.5, respectively. These results are combined with those obtained by D0 at {radical}s = 1.8 TeV, which increases these LQ mass limits to 256 and 234 GeV/c{sup 2}.
Our group has developed a physician-operated inpatient order-entry system (BICS-OE). Mindful of the problems inherent in bringing a radical cultural change such as this to the hospital, we conducted...Full Text Available
BackgroundThe optimal treatment for locally recurrent rectal cancer (LRRC) is still a matter of debate. This study assessed the outcome of LRRC patients treated with multimodality...Full Text Available
Background. The Free Radical Theory of Aging mechanistically links oxidative stress to aging. Okinawa has among the world's longest-lived populations but oxidative stress in this...Full Text Available
Recurrent tumour after radical pancreaticoduodenectomy may cause obstruction of the small bowel loop draining the liver. Roux-loop obstruction presents a particular therapeutic challenge, since the...Full Text Available
The CNS can exhibit features of inflammation in response to injury, infection or disease, whereby resident cells generate inflammatory mediators, including cytokines, prostaglandins, free radicals and...Full Text Available
Because copper catalyzes the conversion of H2O2 to hydroxyl radicals in vitro, it has been proposed that oxidative DNA damage may be an important component of copper toxicity....Full Text Available
It was previously reported that the tritium tracer method is useful for the quantitative consideration of hydrogen behavior in coal during coal liquefaction reaction. Tetralin is excellent hydrogen donating solvent, and is considered as one of the model compounds of coal. In this study, effects of H2S and H2O on the hydrogen exchange reaction between tetralin and gaseous hydrogen labeled by tritium were investigated. It was suggested that the conversion of tetralin and the hydrogen exchange reaction between gaseous hydrogen and tetralin proceed through the radical reaction mechanism with a tetralyl radical as an intermediate product. When H2S existed in this reaction, the hydrogen exchange yield increased drastically without changing the conversion yield. This suggested that the hydrogen exchange reaction proceeds even in the reaction where radical does not give any effect. In the case of H2O addition, the conversion yield ...
By using EPR measurements of radiation-induced radicals it is possible to utilize human fingernails to estimate radiation dose after-the-fact. One of the potentially limiting factors in this...Full Text Available
The dissociation of methylal is investigated using mass spectrometry, combined with a pyrolytic radical source and femtosecond pump probe experiments. Based on preliminary results two reaction paths of methylal dissociation are proposed and discussed. (author) 4 fig., 3 refs.
ObjectiveThe aim of this study was to ascertain whether all cervical cancer patients who received adjuvant concurrent chemoradiation (CCRT) for high risk of treatment failure after...Full Text Available
Two additional hyperfine components of the interstellar radical C3H were detected. In addition, methanol was discovered in interstellar clouds. The abundance of HCCN and various chemical isomers in molecular clouds was investigated.
OBJECTIVE: To test the hypothesis that perioperative transfusion of allogeneic and autologous red blood cells (RBCs) stored for a prolonged period speeds biochemical recurrence of prostate cancer...Full Text Available
RC-12 [1,2-dimethoxy-4-(bis-diethylaminoethyl)-amino-5-bromobenzene] was evaluated for prophylactic, radical curative, and suppressive activities against infections with Plasmodium cynomolgi and subacute...Full Text Available
... Risk (Adverse) for Endangered Species: Risk to aquatic species if anticipated pesticide residue levels equal one-fifth of LD10 or one-tenth of LC50; risk to ...terrestrial species if anticipated pesticide residue levels equal one-fifth of LC10 or one-tenth of LC50. Risk Assessment: Qualitative and quantitative evaluation of the ... Risk for Non-Endangered Species: Risk to species if anticipated pesticide residue levels are equal to or greater than LC50. Risk Management: The process ...
Pulse radiolysis has been used to optically and kinetically characterize the transient free radicals formed by the reaction of H"s"m"-"b"u"l"l"e"t, N_3"s"m"-"b"u"l"l"e"t, or OH"s"m"-"b"u"l"l"e"t with 2,4,5-trichlorophenol (TCP-OH). The hydroxy-2,4,5-trichlorocyclohexadienyl radical (H-TCP-OH) formed by H"s"m"-"b"u"l"l"e"t addition to TCP-OH [k = (1.1 #+-# 0.2) x 10"9 M"-"1 s"-"1] has an absorption maximum at 360 nm with #epsilon#_3_6_0 = (4700 #+-# 1000) M"-"1 cm"-"1. The 2,4,5-trichlorophenoxyl radical (TCP-O"s"m"-"b"u"l"l"e"t) formed by the reaction of N_3"s"m"-"b"u"l"l"e"t with TCP-O- [k = (4.3 #+-# 0.8) x 10"9 M"-"1 s"-"1] has an absorption maximum at 430 nm with #epsilon#_4_3_0 = (3600 #+-# 600) M"-"1 cm"-"1. The dihydroxy-2,4,5-trichlorocyclohexadienyl radical (HO-TCP-OH) formed by OH"s"m"-"b"u"l"l"e"t radical addition to TCP-OH [k = (1.2 #+-# 0.1) x 10"1"0 M"-"1 s"-"1] has an ...
Chlorophyll a, chlorophyll b, and bacteriochlorophyll a in aqueous micellar solutions of Trition X 100 (2%) are readily oxidized by pulse-radiolytically generated N_3., Br_2"-., and (SCN)_2"-. radicals at nearly diffusion-controlled rates. The kinetic study suggests that pigment molecules occupy multiple sites in the micelle. Pheophytin a is only oxidized by N_3. and Br_2"-. radicals. The absolute spectra and the molar extinction coefficients of chlorophyll a, bacteriochlorophyll a, chlorophyll b, and pheophytin a cations have been determined. The chlorophyll a cation has been observed in the presence of pigment aggregates.
Forty-three patients with basal and squamous cell carcinomata arising on the pinna were treated radically using a 10 MeV electron beam. The technique and dosage are described and discussed. Primary cancer control with retention of the pinna was achieved in 34 patients. Salvage pinnectomy was performed in four patients for recurrence and one patient for radiation necrosis. Two patients with large primary tumours failed to resolve and died of their disease. The advantages for the patient of the policy of primary radical electron beam therapy are discussed.
Hydroperoxides are important atmospheric oxidants. They are responsible for most of the oxidation of aqueous-phase SO(sub 2) to sulfate in the northeastern United States, resulting in the formation of acid precipitation and visibility-reducing sulfate aerosol (Penkett et al., 1979; Lind et al., 1987; Madronich and Calvert, 1990; Tanner and Schorran, 1995). Atmospheric hydrogen peroxide (H(sub 2)O(sub 2) or HP) is produced by the self-reaction of hydroperoxyl radicals (HO(sub 2)); higher organic peroxides are produced by reaction of HO(sub 2) with alkylperoxyl radicals (RO(sub 2)). Peroxyl radicals, along with OH, are chain carriers in the complex photochemical process that produces tropospheric ozone. Thus, concentrations of peroxides and their free radical precursors depend on solar intensity and ambient concentrations of water vapor, ozone, NO(sub x) (NO+ NO(sub 2)), and VOCs (volatile organic ...
The authors present a measurement of the B{sub s}{sup 0} meson lifetime using fully and partially reconstructed hadronic decays B{sub s}{sup 0} {yields} D{sub s}{sup -} {pi}{sup +}(X) followed by D{sub s}{sup -} {yields} {phi}{pi}{sup -}. The data sample was recorded with the CDF II detector at the Fermilab Tevatron and corresponds to an integrated luminosity of 1.3 fb{sup -1} from p{bar p} collisions at {radical}s = 1.96 TeV.
Purpose: To conduct a retrospective analysis within a large university teaching hospital, comparing outcomes between patients receiving either radical surgery or radiotherapy as curative treatment for bladder cancer. Patients and Methods: Between March 1996 and December 2000, 169 patients were treated radically for muscle-invasive bladder cancer. Data were collected from patient notes. Statistical analyses were performed using Kaplan-Meier methods and Cox proportional hazards regression analysis to compare radiotherapy and surgical outcome data. Results: There was no difference in overall, cause-specific, and distant recurrence-free survival at 5 years between the two groups, despite the radiotherapy group being older (median age, 75.3 years vs. 68.2 years). There were 31 local bladder recurrences in the radiotherapy group (24 solitary), but there was no significant difference in distant recurrence-free survival. In a more recent (2002-2006) ...
... The costal plain still supports Jarrah (Eucalyptus marginata ) forest, dense woodlands, coastal heath and diverse swamplands. Many species of plants are endemic. 20 species of mammals and 12 species of introduced mammals including with feral pigs, rabbits and foxes of particular concern....
Many species introduced by humans for social and economic benefits have invaded new ranges by escaping from captivity. Such invasive species can negatively affect biodiversity and economies. Understanding...Full Text Available
Numbers of non-indigenous species--species introduced from elsewhere - are increasing rapidly worldwide, causing both environmental and economic damage. Rigorous quantitative risk-analysis frameworks,...Full Text Available
BackgroundSister species divergence and reproductive isolation commonly results from ecological adaptation. In mimetic Heliconius butterflies, shifts in colour pattern...Full Text Available
Species invasions are a principal component of global change, causing large losses in biodiversity as well as economic damage. Invasion theory attempts to understand and predict invasion success and...Full Text Available
Abstract: Some conservationists argue for a focused effort to protect the most critically endangered species, and others suggest a large-scale endeavor to safeguard common species across large areas. Similar arguments are applicable to the distribution of scientific effort among species. Should conservation scientists focus research efforts on threatened species, common species, or do all species deserve equal attention? We assessed the scientific equity among 1909 mammals, birds, reptiles, and amphibians of southern Africa by relating the number of papers written about each species to their status on the International Union for Conservation of Nature Red List. Threatened large mammals and reptiles had more papers written about them than their nonthreatened counterparts, whereas threatened...
BackgroundCo-flowering plant species frequently share pollinators. Pollinator sharing is often detrimental to one or more of these species, leading to competition for pollination....Full Text Available
Since the last review of the problem of insecticide-resistance was presented in this journal at the beginning of 1958, resistance has been discovered in 16 new species, and in at least 14 species both...Full Text Available
Social organisms that cooperate with some members of their own species, such as close relatives, may fail to cooperate with other genotypes of the same species. Such noncooperation may take the form...Full Text Available
Monthly sampling of slightly alkaline arsenic-rich stream in the Mokrsko gold deposit revealed seasonal variations in dissolved Zn, Cu, As and Mo. Concentrations of trace metal cations (Zn, Cu) increased as much as 330 and 178%, respectively, from minimum mean values at autumn to maximum mean values at spring. In contrast, concentrations of trace element oxyanions (As, Mo) revealed opposite seasonal pattern with increase to 189% (As) and 123% (Mo) during summer?autumn, indicating that in-stream biogeochemical process(es) played the main role in controlling the seasonal variations of these trace elements. The trace elements were mainly scavenged by low crystalline Mn oxyhydroxide and Fe oxyhydroxide (ferrihydrite). Results are consistent with sorption and coprecipitation processes controlli...
Microgel-clay composite particles were prepared by one-step surfactant-free precipitation polymerization. Laponite nanoparticles present in the reaction mixture become encapsulated during the microgel formation process. Microgel-clay composites based on poly(N-vinylcaprolactam-co-acetoacetoxyethyl methacrylate) containing different amount of incorporated clay nanoparticles were synthesized. The clay content was varied from 2 wt% to 18 wt%. The extremely high incorporation efficiency of the clay nanoparticles into microgels was detected. The size of the hybrid microgels was decreased from 700 nm to 100 nm by increase of the clay concentration in the reaction mixture. Obtained hybrid microgels exhibit negative surface charge and excellent colloidal stability. Microgel-clay composite particle...
The performance of the gaseous fuel supply and its influence on hydrocarbon (HC) emissions of dual-fuel engines have been investigated. A new design of manifold respirators with mixers is also presented in the paper. The design of the gaseous fuel supply system has a great influence on HC emissions in the dual-fuel engine at light load. The problem of scavenging is discussed and solved by using the manifold respirators in the dual-fuel engine. It performs the function of retarding the gaseous fuel entry timing from the moment of intake valve opening, and its delaying effects have been measured and tested. Experimental results show that the manifold respirator gives the best performance in reducing HC emissions compared with a common pipe mixer and a respirator with bo miser. In addition, the mixing effects are sensitive to the mixer configuration. (Author)
The function of selenium in an organism is mediated mostly by selenoproteins including glutathione peroxidase. Glutathione peroxidase is a potent anti-oxidative enzyme, scavenging a variety of peroxides. The green alga Scenedesmus quadricauda was used to investigate the relationship between the toxicity of selenium and the glutathione peroxidase activity. Selenium resistant strains SeIV and SeVI were synchronized and grown in high concentrations of Se (selenite or selenate). As a measure of selenium toxicity the EC50 values were determined. During growth of the untreated wild type, glutathione peroxidase activity increased slightly and then declined gradually until the end of the cell cycle. A similar pattern was observed in untreated resistant strains and when resistant strains were grown...
Detailed chemical kinetic reaction mechanisms are developed for combustion of all nine isomers of heptane (C{sub 7}H{sub 16}), and these mechanisms are tested by simulating autoignition of each isomer under rapid compression machine conditions. The reaction mechanisms focus on the manner in which the molecular structure of each isomer determines the rates and product distributions of possible classes of reactions. The reaction pathways emphasize the importance of alkylperoxy radical isomerizations and addition reactions of molecular oxygen to alkyl and hydroperoxyalkyl radicals. A new reaction group has been added to past models, in which hydroperoxyalkyl radicals that originated with abstraction of an H atom from a tertiary site in the parent heptane molecule are assigned new reaction sequences involving additional internal H atom abstractions not previously allowed. This process accelerates autoignition in fuels with ...
Some 43 papers were presented in 4 sections: Organ and bud culture of tree species (24 papers); Cell suspension and callus culture of tree species (11); Culture of haploid tissue of tree species and production of wood homozygotes (3); and Isolation, culture and somatic fusion of protoplasts as a means of somatic hybridization and genetic engineering (5).
Sida cordifolia is a plant belonging to the Malvaceae family used in many ayurvedic preparations. This study aimed at assessing the effects of ethanolic extract of Sida cordifolia root on quinolinic acid (QUIN) induced neurotoxicity and to compare its effect with the standard drug deprenyl in rat brain. Rats were divided into six groups: (1) control group (2) QUIN (55 microg/100 g bwt/day) (3) 50% ethanolic plant extract treated group (50 mg/100 g bwt/day) (4) Deprenyl (100 microg/100 g bwt/day) (5) QUIN (55 microg/100 g bwt/day) + 50% ethanolic plant extract treated group (50 mg/100 g bwt/day) (6) QUIN (55 microg/100 g bwt/day) + Deprenyl (100 microg/100 g bwt/day). At the end of the experimental period a status of lipid peroxidation products, protein peroxidation product, activities of the scavenging enzymes and the activities of the inflammatory markers were analyzed. Results revealed that the lipid peroxidation products decreased and the activities of the ...
Two new species of the genus Microplana are described from the Iberian Peninsula. The new taxa are compared with congeneric species. Distributional records for two other European species, Microplana monacensis (Heinzel, 1929) and Microplana groga Jones et al. 2008, are presented and the presence of Microplana terrestris (Muller, 1774) is confirmed on the Iberian Peninsula. A partial re-description of Microplana nana Mateos, Giribet and Carranza, 1998 is provided. The finding of a new and probably introduced, but unidentified, species of land planarian is reported. Land planarians were generally found in the vicinity of deciduous trees and rivers.
The A2P-X2+Dv=-3 bands of the 12C14N radical have been observed by time-resolved Fourier transform spectroscopy in the 1850-3100cm-1 region with a wavenumber resolution of 0.025cm-1. The radical was produced in a pulsed positive column discharge in a cyanogene and helium mixture. Seven bands of v=0-3, 1-4, 2-5, 3-6, 4-7, 5-8, and 6-9 were analyzed to give the molecular constants of each state by least-squares fitting of 801 lines. The pulsed discharge was found to be efficient for production of CN in the excited A2P state. The vibrational excitation temperature was determined to be 6680+-835K and 6757+-534K for the A2P and X2+ states, respectively. The population of the A2P was found to be 4% of that of the X2+ state in the time after turning off the discharge.
A novel technique is proposed for the growth of an InN film on a GaN/Al2O3(0001) template by radio-frequency plasma-excited molecular beam epitaxy (RF-MBE). The method involves 1) InN growth under an In-rich condition and 2) additional nitrogen radical irradiation after the InN growth under an In-rich condition. Excess In that appeared on the InN surface in the InN growth under an In-rich condition is transformed to InN by the additional nitrogen radical irradiation. The effective V/III ratio is easily controlled by monitoring the intensity in a reflection high-energy electron diffraction (RHEED) pattern. The growth of the InN film by repeating the InN growth under an In-rich condition and the additional nitrogen radical irradiation is also demonstrated. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)
It is well established from experiments in premixed, laminar flames, jet-stirred reactors, flow reactors, and batch reactors that SO2 acts to catalyze hydrogen atom removal at stoichiometric and reducing conditions. However, the commonly accepted mechanism for radical removal, SO2 + H(+M) reversible arrow HOSO(+M), HOSO + H/OH reversible arrow SO2 + H-2/H2O, has been challenged by recent theoretical and experimental results. Based on ab initio calculations for key reactions, we update the kinetic model for this chemistry and re-examine the mechanism of fuel/SO2 interactions. We find that the interaction of SO, with the radical pool is more complex than previously assumed, involving HOSO and SO, as well as, at high temperatures also HSO, SH, and S. The revised mechanism with a high rate constant for H + SO2 recombination and with SO + H2O, rather than SO2 + H-2, as major products of the HOSO + H reaction is in agreement with a range of ...
Lysozyme dimers produced on oxidation of lysozyme with Br_2anion radicals in aqueous solutions exhibit a fluorescence spectrum (lambdasub(max) = 400 nm) closely similar to that of bi-tyrosine. This suggests that the dimer is likely to have a tyrosine-tyrosine bond resulting from the combination of tyrosine phenoxy radicals of two lysozyme molecules. Kinetic studies on dimer formation were made by measuring time-dependent fluorescence after pulsed-electron irradiation over wide pH range. The results lead to the following conclusions. The second-order growth of the dimer fluorescence observed at pH 10.7-12.5 reflects the combination process of the lysozyme radicals, which is rate-determining in the pH range. On the other hand, the first-order growth observed at pH 6.8-10.2 is attributable to the enolization of the keto-form of the dimer. A tentative reaction scheme is proposed for the dimer formation. (author).
The present study was undertaken in 27 children with localized Ewing's sarcoma treated at our hospital. In 9 cases the lesion was central and in 18 peripheral. Treatment consisted of: 1) Chemotherapy with 6 drugs (vincristine, cyclophosphamide, methotrexate, bleomycin, dactinomycin and doxorubicin) for one year in all patients; 2) Radiotherapy in 24 patients at a dose of 30-40 Gy in the entire bone with a booster dose of 10-15 Gy in the lesion. In 7 patients debulking surgery was performed followed by irradiation. Two cases with tumor in expendable bones and one with extensive destructive lesion in the tibia underwent radical surgery. One patient suffered local recurrence (femur) and 6 developed distant metastases. The remaining 20 (74%) patients were alive and tumor-free after follow-up periods of 17-80 months. Among the 12 patients with extremity lesions who were alive, 7 (58%) had minimal or mild treatment sequelae, 2 moderate, and 3 severe sequelae but no ...
Bacteriophage M13 mp10 DNA were irradiated with near-UV light in the presence of tetracycline derivatives and primed with synthetic oligonucleotide to be used for DNA synthesis using Escherichia coli DNA polymerase. Chain terminations were observed by denaturing polyacrylamide gel electrophoresis and mapped precisely. All the synthesis stops occurred before or at the level of guanine residues, showing that the photoreaction mediated by tetracycline derivatives led to a preferential alteration of guanine residues. These lesions were demonstrated to be induced in DNA through a pathway involving singlet oxygen. Tetracycline derivatives also photoinduced the breakage of the DNA sugar-phosphate backbone monitored by the conversion of supercoiled phi X174 DNA to a relaxed form. This lesion was shown to be initiated by hydroxyl radicals. The production of this free radical has been confirmed by electron paramagnetic resonance (EPR) spin trapping ...
Two measurement methods to determine the rate of neutral free radical production by the photo-deionization of negative ion beams (PDINIB) are introduced. These methods, namely, photoelectron-current measurement by low-frequency electro-modulation probe (PMMP) and measurement of decrease in the negative-ion beam current (DNIC) were employed to evaluate the production rate in a trial surface-processing apparatus developed in the author's laboratory utilizing a steady-flux refined beam of neutral free radicals (RBNR) produced by the PDINIB procedure. A {sup 63}Cu{sup -} negative ion beam of kinetic energy E{sub i} varied up to 15 keV was irradiated with a 514.5 nm visible light beam from a 25 W CW Ar{sup +} ion laser. The detection limit of the production rate by the PMMP setup was as high as 6 x 10{sup 9} s{sup -1} under the condition that E{sub i}=15 keV, the negative-ion beam current I{sub i}=4 {mu}A and the laser power P=6 W. The DNIC ...
We summarize the predictions of different models for total #gamma##gamma# cross-sections. The experimentally observed rise of #sigma#_#gamma#_#gamma# with s radical _#gamma#_#gamma#, faster than that for #sigma#_p_-_b_a_r_p, #sigma#_#gamma#_p is in agreement with the predictions of the Eikonalized Minijet Models as opposed to those of the Regge-Pomeron models. We then show that a measurement of #sigma#_#gamma#_#gamma# with an accuracy of < or approx. 8-9% (6-7%) is necessary to distinguish among different Regge-Pomeron type models (the different parameterisations of the EMM models) and a precision of < or approx. 20% is required to distinguish the predictions of the EMMs and of those models which treat 'photon like a proton', for the energy range 300< s radical_#gamma#_#gamma# <500 GeV. We further show that the difference in model predictions for #sigma#_#gamma#_#gamma# of about a factor 2 at s radical ...
The authors search Z{prime} bosons in dielectron events produced in p{bar p} collisions at {radical}s = 1.96 TeV, using a 0.45 fb{sup -1} dataset accumulated with the CDF II detector at the Fermilab Tevatron. To identify the Z{prime} {yields} e{sup +}e{sup -} signal, both the dielectron invariant mass distribution and the angular distribution of the electron pair are used. No evidence of a signal is found, and 95% confidence level lower limits are set on the Z{prime} mass for several models. Limits are also placed on the mass and gauge coupling of a generic Z{prime}, as well as on the contact interaction mass scales for different helicity structure scenarios.
The incidence of hilar cholangiocarcinoma is very rare worldwide. Radical resection is the only prognostic factor for long survival in patients with hilar cholangiocarcinoma. Postoperative radiation therapy can improve local control and survival rates for patients with palliative resection, but it remains controversial in patients with radical resection. Biliary drainage can effectively release bile duct obstruction for the majority of patients with locally advanced disease, and may even prolong survival when combined with radiation therapy. Radiation therapy includes extrernal beam therapy alone, external beam therapy with intraluminal brachytheapy and new radiation technique, such as three dimentional conformal therapy and intensity modulated radiation therapy. The propective randomized clinical study is needed for further investigation in the role of combined modality therapy especially for hilar cholangiocarcinoma. (authors)
Purpose. To compare erectile function (EF) recovery of patients treated by early penile rehabilitation therapy (PRT) with sildenafil and with control group. Method. Forty men treated by bilateral nerve sparing radical prostatectomy (NSRP) and with a normal pre-operative EF were enrolled. Fourteen days after surgery, they were randomised to a flexible-dose sildenafil group and to a control group. The International Index of Erectile Function (IIEF) questionnaire was completed before surgery and at 3, 6, 12 and 24 weeks after NSRP. Results. In the group treated, the mean IIEF score before surgery was 26.2 and 14.1, 16.2, 22.5 and 25.2 at 3, 6, 12 and 24 weeks after NSRP, respectively. In the control group, the respective scores were 26.5 and 12.4, 15.8, 15.3 and 17.4. There was a significant ...
ABSTRACT Introduction. Postprostatectomy erectile dysfunction (ED) remains a serious quality-of-life issue. Recent advances in the understanding of the mechanism of postprostatectomy ED have stimulated great attention toward penile rehabilitation. Aim. This review presents and analyzes a contemporary series of the recent medical literature pertaining to penile rehabilitation therapy after radical prostatectomy (RP). Main Outcome Measures. The laboratory and clinical studies related to penile rehabilitation are analyzed. The validity of the methodology and the conclusion of the findings from each study are determined. Methods. The published and presented reports dealing with penile rehabilitation following RP in human and cavernous nerve injury in animal models are reviewed. Results. Exciti...
The optimal management of men with very favorable clinicopathological factors who develop biochemical recurrence (BCR) after radical prostatectomy (RP) has not been previously reported. Both local and systemic recurrences are unlikely in this cohort. This study examines their management and outcomes. Between October 2000 to March 2010, 1627 men underwent open RP by a single surgeon. In all, 448 (27.5%) met the following criteria for extremely low risk disease: preoperative PSA level <10?ng?ml?1, clinical stage T1c/T2a, Gleason score ?6, estimated cancer volume in the surgical specimen ?5% and no evidence for positive surgical margin. Undetectable PSA was defined as ?0.04?ng?ml?1. BCR was defined as PSA ?0.2?ng?ml...
One-electron oxidation of several derivatives of pyrazolin-5-one, including the drug antipyrine, were studied by pulse radiolysis of aqueous solutions. All the compounds were found to be oxidized by Br2 rapidly but considerably more slowly by weaker oxidants, such as peroxyl radicals. From redox equilibria using p-methoxyphenol and N,N,N',N'-tetramethyl-p-phenylenediamine as reference compounds, the one-electron oxidation potentials of the methyl-substituted 2-pyrazolin-5-ones were found to be in the range of 0.32-0.39 V versus normal hydrogen electrode. The relevance of these findings to the properties of the drug nafazatrom is discussed. Antipyrine was found to have a much higher oxidation potential, estimated as 1.2-1.5 V, which is rationalized on the basis of the phenyl substitution and lack of resonance stabilization of the radical cation.
The radiation induced reactions in LDPE in the presence of phenolic type antioxidants have been studied. It was shown that various antioxidants can influence the polyethylene network formation and the radical yield in different ways. The dependence of network structure on absorbed doses was determined by gel analysis, hot-set test and extraction of antioxidants for samples irradiated with accelerated electrons. It was found that the antioxidants eluted from polyethylene in higher percentage influence polymer crosslinking to a smaller degree. The ESR studies of #gamma#-irradiated blends of polyethylene with antioxidant indicate the presence of alkyl and phenoxyl radicals. The role of antioxidant molecules on radiation induced reactions in polyethylene-antioxidant systems is considered. The correlation between the network structure and the type of additive in polyethylene is also discussed. (author).
Five arylethylenes with 1-naphthyl, 2-naphthyl, and phenyl groups in 1,2-positions have been studied for singlet-mediated charge-transfer interactions with several amines and paraquat dication. 1-Phenyl-2-(2-naphthyl)ethylene and 1,2-di(2-naphthyl)ethylene exhibit distinct dependence of exciplex emission maxima and lifetimes, and fluorescence quenching constants, on excitation and/or monitoring wavelengths; this is in conformity with the existence of ground-state rotamers for these systems, wtih distinguishable absorption-emission spectra and fluorescence lifetimes. The fluorescence quenching by aromatic amines and paraquat dication occurs with rate constants in the limit of diffusion control and is accompanied by the formation of radical ions in polar solvents (acetonitrile). The transient spectra and kinetics associated with the radical ions, observed by 337.1- and 355-nm laser flash photolysis, are also reported. 10 figures, 4 tables.
Evidence is reported for a narrow structure near the J/{psi}{phi} threshold in exclusive B{sup +} {yields} J/{psi}{phi}K{sup +} decays produced in {bar p}p collisions at {radical}s = 1.96 TeV. A signal of 14 {+-} 5 events, with statistical significance in excess of 3.8 standard deviations, is observed in a data sample corresponding to an integrated luminosity of 2.7 fb{sup -1}, collected by the CDF II detector. The mass and natural width of the structure are measured to be 4143.0 {+-} 2.9(stat) {+-} 1.2(syst) MeV/c{sup 2} and 11.7{sub -5.0}{sup +8.3}(stat) {+-} 3.7(syst) MeV/c{sup 2}.
Abstract Purpose: We evaluated complications of urologic laparoscopic surgery at our institution. Patients and Methods: From December 1991 to January 2009, 1017 urologic laparoscopic surgical procedures were performed in Kansai Medical University, including 277 radical prostatectomies, 13 donor nephrectomies, 74 partial nephrectomies, 158 radical nephrectomies, 55 pyeloplasties, 97 nephrouretectomies, 54 simple nephrectomies, 128 adrenalectomies, 34 varicocelectomies, and 127 other procedures. Medical records of each procedure were retrospectively evaluated. The difficulty of each procedure was classified according to the European Scoring System (ESS). Intraoperative and postoperative complications were graded according to the Satava and Clavien classifications, respectively. Results: Amon...
The reactions of the hydroxyl radical with hydrocarbons and fluoro hydrocarbons attract significant attention due to their importance in atmospheric chemistry. Its reactions with the two first hydrocarbons, methane and ethane are of special interest because, owing to the small size of these systems, they serve as a prototype for the theoretical studies of hydrogen abstraction reactions. In this work, the reaction and activation energies of the hydroxyl radical abstraction reaction with methane and ethane have been investigated by correlated ab initio and DFT methods. The DFT reaction energies are in good agreement with experimental values, but the activation energies may be in severe error. (authors) 22 refs.
I describe a search for anomalous production of Z pairs through a new massive resonance X in 2.5-2.9 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV using the CDFII Detector at the Fermilab Tevatron. I reconstruct Z pairs through their decays to electrons, muons, and quarks. To achieve perhaps the most efficient lepton reconstruction ever used at CDF, I apply a thorough understanding of the detector and new reconstruction software heavily revised for this purpose. In particular, I have designed and employ new general-purpose algorithms for tracking at large {eta} in order to increase muon acceptance. Upon analyzing the unblinded signal samples, I observe no X {yields} ZZ candidates and set upper limits on the production cross section using a Kaluza-Klein graviton-like acceptance.
The high rate of deforestation over the Andean forests has generated a large proportion of fragmented landscapes in the country. The distribution of oak groves in the country was determined based on ecosystem maps. Charala and Encino oak groves patches are the largest ones found at the east Andes and like others, due to the unfair use of these resources, have suffered a fragmentation process. Fifty-five species of mammals included in 10 orders and 14 families were found in these forests. Chiroptera and Rodentia were the most representative groups. Anthropic processes had produced a 68.1% loss of the habitat and constitute the main threat for these forests. The sizes of the patches were evaluated for three mammal species categories. The patches' area are not favorable for large-size species, intermediately to favorable to medium-size species and are favorable for small-size species. ...
A method and device have been provided for distinguishing Africanized honeybees from European honeybees. The method is based on the discovery of a distinct difference in the acoustical signatures of these two species of honeybees in flight. The European honeybee signature has a fundamental power peak in the 210 to 240 Hz range while the Africanized honeybee signature has a fundamental power peak in the 260 to 290 Hz range. The acoustic signal produced by honeybees is analyzed by means of a detecting device to quickly determine the honeybee species through the detection of the presence of frequencies in one of these distinct ranges. The device includes a microphone for acoustical signal detection which feeds the detected signal into a frequency analyzer which is designed to detect the presence of either of the known fundamental wingbeat frequencies unique to the acoustical signatures of these species as an indication of the ...
The known metazoa parasite fauna of the invasive round goby Apollonia melanostoma (formerly Neogobius melanostomus) consists of 12 species. The core of the parasite fauna comprises two species: Cryptocotyle concavum and Diplostomum spathaceum; secondary species are absent; satellite species include Cercariae gen. sp. and Ergasilus sieboldi; rare species are Acanthocephalus lucii, Anguillicola crassus, Bothriocephalus sp., Dichelyne minutus, Hysterothylacium aduncum, Pomphorhynchus laevis, Piscicola geometra, and Tylodelphys clavata. Fifty percent of metazoa parasites that occurred in the invasive round goby in the Gulf of Gda?sk (an invasion that was first detected in 1990) are also typically found in the native Gulf of Gda?sk gobiids. The round goby hosts common fish parasite species: C. ...
Mowing a meadow is an example of an equalizing process that reduces differences among species by removing aboveground biomass approximately 5?cm above ground. This regular disturbance that affects all plants prevents competitive exclusion of small species and thus allows coexistence of numerous species differing in shoot size. In this paper we search for the mechanism behind this by comparing the shoot biomass of 41 common species in dry and wet species-rich meadows in mown and recently abandoned plots in June (before mowing) and in October. We asked the following questions: i) Do the plants differ in proportion of biomass lost by mowing? ii) Are the mown plants able to compensate for biomass lost by mowing? iii) Is the compensatory ability of mown plants related to their size? iv) Is the ...
Often ecologists and natural resource managers can easily access data on invasive species occurrence across a region. Yet, collecting species abundance data over a large area is arguably more important for decision making, but inherently costly, so methods which can provide robust information at low-cost are particularly valuable. Studies of species distribution often use occurrence data to build models of the environmental niche. Environmental suitability derived from such models may be used to predict the potential distributions of species. The ability of such models to predict spatial patterns in abundance have recently been demonstrated. Here we tested the relationship of environmental suitability with local abundance of an aquatic invasive species, olive hymenachne (Hymenachne amplexi...
The association between invasive and native species varies across spatial scales and is affected by phylogenetic relatedness, but these issues have rarely been addressed in aquatic ecosystems. In this study, we used a non-native, highly invasive species of Poaceae (tropical signalgrass) to test the hypotheses that (i) tropical signalgrass success correlates negatively with success of most native species of macrophytes at fine spatial scales, but its success correlates positively or at random with natives at coarse spatial scales, and that (ii) tropical signalgrass is less associated with native species belonging to the family Poaceae than with species belonging to other families (Darwin?s naturalization hypothesis). We used a dataset obtained at fine (0.25?m2) and coarse (ca. 1,000?m2) sca...
The use of absorbable polyglactin 910 mesh (Vicryl) is described in a case of Ewing's sarcoma of the pelvis. An operation was performed to hold the small bowel and colon out of the pelvis for a temporary period during which radical radiotherapy was delivered. The mesh allowed the temporary displacement of bowel and obviated bowel radiation morbidity. (author).
Although silicosis has been studied extensively, the mechanism is still not fully understood. Experiments do provide evidence that the actions of unique properties of silica surface on the cell membrane are the starting point of silicotic processes. This paper summarizes literature on chemical properties of silica surface, and the effect of particle size on silica toxicity. This paper also discusses the ways in which silica dusts are though to interact with the cell membrane, with emphasis on freshness, hydrogen bonding, and free-radical interactions.
The application of kinetic probes that allow one to determine relative reactivities of biologically relevant substrates with oxidizing intermediates in the Fenton reagent (H2O2 plus Fe2+ in acidic aqueous...Full Text Available
The purpose of work is systematical studying of benzo (B) of thiophene-1,1-dioxides and their 2,3-di-hydro derivatives behaviour in the reactions of electrophflic, radical, nucleophilic nitration, reduction of nitro group, embodiment of synthesis of N-amino derivatives, investigation of sulfur containing hetero-cyclic compounds, including of residues of some steroids
Abstract A diacrylate polysulfone oligomer is synthesized and used as the acrylic oligomer for the in situ synthesis of noble metal/PSU nanocomposites through UV-induced simultaneous radical polymerization of acrylic functionalities and NP formation by reduction of their precursors. Thus, silver or gold NPs are formed in situ during polymer network formation. FESEM analysis of the morphology of the cured systems demonstrates that the nanoparticles of the noble metals are homogeneously distributed in the network without macroscopic agglomeration.
We demonstrate the nonuniqueness of the basic assumptions leading to spiral structure in self-propagating star formation models. Even in the case where star formation occurs purely spontaneously and does not propagate, we have generated spiral structure by adopting the radically different assumption where star formation is systematically inhibited.
The use of low rank coal leads to a reduction of the coke strength because of the reduction of the caking property of coking coal. The authors have tried to understand this mechanism by extracting and analyzing the caking component of low rank coal and coking coal. It was found that the caking component is decreased by radical attack from the low rank coal, and thus the caking property is reduced. 11 figs., 3 tabs.
There have been no radically new commercial bulk explosives since Atlas Powder Company's introduction of emulsions onto the market in 1968. But the effectiveness, safety and management of these familiar explosives is continuously being improved by the development of blast design techniques, explosives delivery and initiation systems, and monitoring methods. The author looks at developments in blasting technology and discusses experiences with Handibulk emulsion delivery systems.
DescriptionProgramme background Nanotechnology is the design and manufacture of substances typically between one and several hundred billionths of a metre in size. In this size range the properties of substances can change quite radically, offering potentially large socio-economic, health and environmental benefits. For example, nanofuel additives could help reduce emissions and particles from diesel engines. Nanoparticles may also be able to help remove persistent pollutants in soils and groundwaters. Th [continued...
The introduction of CT scan and, more recently, magnetic resonance imaging, has radically changed the diagnostic approach to tumors developed in the internal auditory canal and cerebellopontine angle. CT scan with intravenous injection visualizes tumors lying in the cerebellopontine angle. Magnetic resonance imaging, especially using gadolinium, is a very accurate means for diagnosing tumors of both the auditory canal and cerebellopontine angle.
Some applications of magnetic resonance in coal liquefaction research described briefly are: (1) investigation of the nature of carbon deposits on used coal-liquefaction catalysts, (2) determination of the fate of hydrogen during coal liquefaction, and (3) observation of transient free radicals during coal pyrolysis. The first two applications make use of cross-polarization /sup 13/C magnetic resonance combined with magic angle spinning, and the third application is an electron spin resonance study. (BLM)
Abstract High Post-Modernism with its understanding of the significance of the image anticipated the flattening of culture, first in advertising and the printed media, and more recently online. Sam Jacob of FAT speculates on architecture's relationship with the Internet, -a flatland of undifferentiated information-, and how Radical Post-Modernism might be best placed to resist the ubiquity of global culture while reanimating the social and cultural agenda of Modernism and Post-Modernism. Copyright 2011 John Wiley & Sons, Ltd.
Mating signals are often directed at numerous senses and provide information about species identity, gender, receptiveness, individual identity and mate quality. Given the diversity of colourful body...Full Text Available
Invasive species are increasingly becoming a policy priority. This has spurred researchers and managers to try to estimate the risk of invasion. Conceptually, invasions are dependent both on the receiving...Full Text Available
Unlike most mammalian species, the prairie vole is highly affiliative, forms enduring social bonds between mates, and displays biparental behavior. Over two decades of research in this species...Full Text Available
Six species having characteristics of plants with the C4 dicarboxylic photosynthetic pathway, Echinochloa utilis L. Ohwi et Yabuno (Japanese millet), Cynodon dactylon...Full Text Available
Alterations in mass transport patterns of low-density lipoproteins (LDL) and oxygen are known to cause atherosclerosis in larger arteries. We hypothesise that the species transport processes in coronary...Full Text Available
Organisms ranging from bacteria and corals to plants and vertebrates can form intransitive competitive networks, in which coexistence can be maintained because no one species or genotype is superior...Full Text Available
... presumed first instar Geocharidius. Anillines occur in deep forest litters, beneath rocks and in soil (endogean), or as ... their small size and cryptic mode of life. Forest litter inhabiting anillines ma...
The presence of albumin structures with the capacity to bind to a surface receptor in group C and G streptococci was studied in serum samples from 45 mammalian species representing 15 different orders,...Full Text Available
BackgroundThe genus Vibrio is a diverse group of Gram-negative bacteria comprised of 74 species. Furthermore, the genus has and is expected to continue expanding...Full Text Available
Some common decay organisms of vegetables and ripened fruits are Alternaria species. Even fruits and vegetables kept under refrigeration can be spoiled by Alternaria species because the mold grows at...Full Text Available
Evolutionary biologists have long been fascinated by both the ways in which species respond to ecological conditions at the edges of their geographic ranges and the way that species' body sizes evolve...Full Text Available
Oryza sativa or Asian cultivated rice is one of the major cereal grass species domesticated for human food use during the Neolithic. Domestication of this species from the wild grass...Full Text Available
Background and AimsPlant species from various taxa ‘escape’ from low oxygen conditions associated with submergence by a suite of traits collectively called the low...Full Text Available
Species of bacteria associated with Stylophora pistillata were determined by analyses of 16S ribosomal genes. Coral samples were taken from two distinct sites at Kenting, in the far...Full Text Available
BackgroundPopulation densities of many species throughout the world are changing due to direct persecution as well as anthropogenic habitat modification. These changes may induce...Full Text Available
Background and AimsVariation in mating patterns may be particularly evident in colonizing species because they commonly experience wide variation in plant density. Here, the role...Full Text Available
BackgroundBengal tiger Panthera tigris tigris the National Animal of India, is an endangered species. Estimating populations for such species is the main objective...Full Text Available
Several Bartonella species have now been implicated as human pathogens. The recovery of these fastidious organisms in the clinical microbiology laboratory remains difficult, and current...Full Text Available
Despite their ecological and economical importance, fishes of the family Ariidae are still genetically and cytogenetically poorly studied. Among the 133 known species of ariids, only eight have been...Full Text Available
Species differences in lifespan have been attributed to cellular survival during various stressors, designated here as ‘cell resilience’. In primary fibroblast cultures, cell...Full Text Available
Increased production of reactive oxygen species (ROS) in mitochondria underlies major systemic diseases, and this clinical problem stimulates a great scientific interest in the mechanism of ROS generation....Full Text Available
Consistent holistic view of sexual species as the highest form of biological existence is presented. The Weismann's idea that sex and recombination provide the variation for the natural...Full Text Available
Thaxtomin A is a phytotoxin produced by Streptomyces scabies and other Streptomyces species, the causative agents of common scab disease in potato and other taproot...Full Text Available
by American scientists, ecosystems containing a greater number of plant species, produce more biomass.This result ...to meet the increasing demand for land for farmland planted with monocultures, buildings and roads.For ...have hypothesized that greater ecological diversity (diversity of plant and animal species) leads to a greater
... Southeastern Forests Feral Pig Fishes of Georgia: Georgia Freshwater Fish Distribution, Classification, and Information Flora of the Oconee National ... ...
Ultraviolet (UV) photoirradiation of Ag(I) compounds in the presence of an aqueous Triton X-100 solution has been exploited for the first time to prepare reproducible yellow silver hydrosol. The evolution of nanosized silver particles has been examined critically under the influence of different anions/ligands. Hence, time dependent evolution of silver hydrosol from different silver compounds in micelle via photochemical reduction is observed. Anions/ligands of precursor salts have been found to show profound influence (due to electron scavenging property, solubility, stability etc.) on the evolution route and efficiency of photochemical reduction of Ag(I) to Ag(O) in micelle and thereby classification of silver compounds becomes possible. Kinetic results reveal that the formation of silver particles proceeds via autocatalytic growth mechanism. The observed variation in rate constant values for the evolution of nanoparticles from different silver compounds have ...
A gas injection diesel engine was developed as an approaching measure to the diversification of fuel. Contrary to the usual low pressure gas application engine, this engine applies a so-called diffuse combustion method, in which high pressure (24.7Mpa) gas fuel is injected directly in the cylinder and is ignited and combusted by a little pilot fuel injected almost at the same time. The engine have following features. As a principle, it can attain the same heat efficiency and output rate as a diesel engine in any load range. It is excellent in responsibility to load fluctuation. There is no internal leakage of gas fuel to the scavenging chamber (the crank chamber) in the compression stroke. Not only a wide range of mixed combustion of gas fuel and heavy oil fuel, but also single combustion of heavy oil is possible. It is, therefore, drawing attention as an engine for an LNG ship and also for a power generation plant with the recent increasing demand of gas fuel ...
The adsorption capacity of radionuclides onto suspended sediment was experimented on each of the coastal seawater sampled around the Kori and the Wolsung nuclear power plant. During the experiment the quantity and size fraction of suspended sediment were adjusted and the seawater and sediment chemistry is approximated to the expected field condition. Because the sorption capacity depends on the specific minerals, ocean chemistry and radionuclide involved, it is necessary to analyze sediment mineralogy. Clay mineral is dominant in seabed mineral and suspended sediment as the result of x-ray diffraction. Radionuclide sorbed to silty-clay mineral can be rather transported to ocean than scavenged to seabed because of low quantity and fine grained suspended sediment in the coast around the Kori and the Wolsung. The result of adsorption examinations shows that {sup 139}Ce and {sup 51}Cr and {sup 110m}Ag are strongly sorbed to suspended particle, while {sup 137}Cs is less ...
The adsorption capacity of radionuclides onto suspended sediment was experimented on each of the coastal seawater sampled around the Kori and the Wolsung nuclear power plant. During the experiment the quantity and size fraction of suspended sediment were adjusted and the seawater and sediment chemistry is approximated to the expected field condition. Because the sorption capacity depends on the specific minerals, ocean chemistry and radionuclide involved, it is necessary to analyze sediment mineralogy. Clay mineral is dominant in seabed mineral and suspended sediment as the result of x-ray diffraction. Radionuclide sorbed to silty-clay mineral can be rather transported to ocean than scavenged to seabed because of low quantity and fine grained suspended sediment in the coast around the Kori and the Wolsung. The result of adsorption examinations shows that "1"3"9Ce and "5"1Cr and "1"1"0"mAg are strongly sorbed to suspended particle, while "1"3"7Cs is less sorbed and ...
Poly(methyl methacrylate), PMMA, Acrigel, a Brazilian polymer, is used in the manufacture of medical supplies sterelizable by ionizing radiation. However, when PMMA is gamma-irradiated it undergoes main chain scissions, which promote molecular degradation causing reduction in its mechanical properties. Therefore, radiolytic of PMMA is important for it to become commercially radiosterizable. In this work some commercial additives, originally used in photo-and thermo-oxidate stabilization of polymers, were tested. Only two additives, type HALS (Hindered Amine Light Stabilizer), denoted Scavenger, showed a good protective quality. The investigation of radiation-induced main scissions was carried out by viscosimetric method. The most effective additive, added to the polymer system at 0.3 w/w%, promotes a great molecular radioprotection of 93%. That means a reduction of G-value (scissions/100 eV) from 0.611 to 0.053. In addition, the glassy transition temperature (T{sub ...
Inductively coupled plasma etching of InGaP, AlInP and AlGaP in BI{sub 3} or BBr{sub 3} discharges was investigated as a function of source power, dc chuck bias and plasma composition. InGaP etches at the fastest rates ({gt}6000thinsp{Angstrom}thinspmin{sup {minus}1}) in both chemistries, followed by AlGaP. It is found that AlInP provides an excellent etch stop for the other two materials in both mixtures. The InGaP surface morphology improves with increasing BI{sub 3} or BBr{sub 3} content, and with increasing dc chuck bias. The etched features for this material are highly anisotropic. Etch selectivities for InGaP over SiO{sub 2} and SiN{sub x} of {ge}8 are obtained in both plasma chemistries, and there is no etch incubation time with either mixture, indicating that both can scavenge the native oxide on InGaP, AlGaP and AlInP. {copyright} {ital 1998 American Vacuum Society.}
Inductively coupled plasma etching of InGaP, AlInP and AlGaP in BI_3 or BBr_3 discharges was investigated as a function of source power, dc chuck bias and plasma composition. InGaP etches at the fastest rates (>6000 Angstrom min"-"1) in both chemistries, followed by AlGaP. It is found that AlInP provides an excellent etch stop for the other two materials in both mixtures. The InGaP surface morphology improves with increasing BI_3 or BBr_3 content, and with increasing dc chuck bias. The etched features for this material are highly anisotropic. Etch selectivities for InGaP over SiO_2 and SiN_x of #>=#8 are obtained in both plasma chemistries, and there is no etch incubation time with either mixture, indicating that both can scavenge the native oxide on InGaP, AlGaP and AlInP. copyright 1998 American Vacuum Society.
This project was conducted to evaluate novel approaches for removing radioactive strontium (Sr) and cesium (Cs) from the tank wastes. The bulk of the Sr removal research conducted as part of this project investigated adsorption of Sr onto a novel adsorbent known as iron-oxide-coated sand. The second major focus of the work was on the removal of cesium. Since the chemistries of strontium and cesium have little commonality, different materials (namely, cesium scavengers known as hexacyanoferrates, HCFs) were employed in these tests. This study bridged several scientific areas and yielded valuable knowledge for implementing new technological processes. The applicability of the results extends beyond the highly specialized application niches investigated experimentally to other issues of potential interest for EMSP programs (e.g., separation of chromium from a variety of wastes using IOCS, separation of Cs from neutral and acidic wastes with EC-controlled HCFs).
The wet and dry venom yields for most Australian native dangerous snakes and a number of non-Australian species are presented. Snakes from the Pseudonaja genus yielded higher than previously published amounts and suggest reconsideration be given to increasing the volume of antivenom in each vial. Higher percentage solids were obtained from venoms from the 4 cobra species (Naja) and Pseudechis genus included in this series. PMID:16937075
The structure of the layers formed on a silver electrode by the adsorption of pyridine, Cl"-, CN"- and SO_4"2"- is discussed. A comparison of the amount of the species adsorbed with their Raman spectra shows that there is no simple relation between the species concentration and the enhancement of the Raman intensity. Furthermore, the inhomogeneity of the layers is shown by Raman microscopy observations. These results lead the authors to propose the formation of a new species stabilized in the colloidal silver layer. The Raman enhancement could be explained by the existence of a resonance effect. (Auth.).
The primary objective of this project is to investigate the effects of global change on the biodiversity of aphid communities in Western Europe. Biodiversity has been examined at 3 levels: total number of species, phenology and reproductive strategy. Data were provided by EXAMINE, the European suction traps network which has been now operating for 35 years. 392 different species have been identified. At each location, total number of species has been regularly increasing, one additional species being caught every 1 or 2 years depending on location. This is due to introduced species but also to warming which favours rare species. No general trend of increasing density has been detected, but phenological earliness of almost all species (annual date of first appearance in suction traps) is strongly correlated with temperature and especially ...
DescriptionPhytoplankton is the collective name given to the microscopic floating plants in seas and lakes. Under certain conditions, the abundance of phytoplankton as a whole or of one or more species in particular, can reach a magnitude at which it is visible through discolouration of the sea. Some of these blooms because of the colour of the water have been called 'Red Tides'. Blooms of some 300 species of the phytoplankton are known as Harmful Algal Bloom (HAB) species in recognition of their poten [continued...
Demidospermus annulus sp. nov. (Platyhelminthes, Monogenea, Ancyrocephalidae) is described from the gills of the catfish Parapimelodus valenciennis L?tken collected in Samboromb?n Bay, Argentina. The new species differs from all congeneric species mainly by the structure of the accessory piece of the male copulatory organ, the sclerotized ring-shaped vaginal aperture and the dorsal bar articulation.
Abstract Mitochondrial ribosomal gene sequences were used to investigate the status of several populations of hydromedusae belonging to the genus Turritopsis (family Oceaniidae). Several nominal species have been described for this genus, but most of them had been synonymized and attributed to one cosmopolitan species, Turritopsis nutricula. A recent revision based on morphological and reproductive characters, however, has shown that many different populations can be distinguished and that several of the nominal Turritopsis species are likely valid biological species. Our investigation using molecular sequence data of 16S mitochondrial gene confirms these results. The Mediterranean Turritopsis must be attributed to Turritopsis dohrnii and the Turritopsis of New Zealand must be referred to ...
Pulse radiolysis was used to examine the nature of the silver species obtained when an aqueous solution containing sequestered Ag"+ ions was reduced by hydrated electrons in the presence of a surfactant macrocyclic crown ether, labeled L, and/or a maltoside surfactant. The initially formed product is the Ag"0(L) species which rapidly loses its ligand (half-life #<=#5 #mu#s) and reacts with another Ag"+(L) ion to form Ag_2"+(L). The latter species decays by a bimolecular process to form the Ag_4"2"+(L)_n species at a faster rate than its ligand free analogue. Ultimately, colloidal metallic silver, (Ag)_n, forms which is stabilized by the surfactant moieties. No long-term stability to the reduced monomolecular species could be obtained.
Surveys were carried out in 2006 and 2007 in Umbria (central Italy) to evaluate the presence of mycotoxigenic fungi and mycotoxins in maize grain sampled at harvest. Fusarium spp., were the most abundant species detected in maize kernels, followed by Aspergillus species of sections Flavi and Nigri and by Penicillium spp. Among Fusarium species, F. verticillioides was the most prevalent species, as detected by PCR directly on the kernels and on the fungi isolated from the kernels, followed by F. proliferatum and F. subglutinans. Fumonisins were the predominant mycotoxins with values, on average, of 4.3 and 5.7mgkg-1, in 2006 and 2007, respectively, with a maximum of 76.3mgkg-1 in the second year. Deoxynivalenol ranged from 0.2 to 3.98mgkg-1 in 2006 (average 1.04mgkg-1) and from undetectable...
We tested two approaches to forecast species distributions while balancing the impact of climate change against the inertia promoted by other influential factors that have been forecast as not changing. Given that mountain species are presumed to be more at risk due to climate warming, we selected an amphibian, a reptile, a bird, and a mammal species present in the Spanish mountains, to model their distributional response to climate change during this century. The climatic forecasts were made according to the general circulation models CGCM2 and ECHAM4 and to the A2 and B2 emission scenarios. We modelled the response of the species to spatial, topographic, human, and climatic variables separately. In our first approach, we compared each of these single-factor models using the Akaike Inform...
W. E. B. Du Bois, one of the brightest lights in African American history, wrote a sparkling critique of the American social and economic system originally planned as part of the Bronze Booklets series, edited and published by Alain Locke and the Associates in Negro Folk Education. The piece was never published and has, until now, been lost to the annals of adult education history. Using historical evidence, the authors examine Du Bois's Basic American Negro Creed and the circumstances that led to its exclusion from the series. It is argued that the Creed was far too radical for the liberal minded Carnegie Corporation and its leaders who were only interested in accommodating adult education for Blacks through the AAAE funded Bronze Booklets. The exclusion of the Creed represents an example of repressive tolerance by the AAAE.
The authors present a search for excited and exotic muon states {mu}*, conducted using an integrated luminosity of 371 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV at the Tevatron with the CDF II detector. They search for associated production of {mu}{mu}* followed by the decay {mu}* {yields} {mu}{gamma}, resulting in the {mu}{mu}{gamma} final state. They compare the data to model predictions as a function of the mass of the excited muon M{sub {mu}*}, the compositeness energy scale {Lambda}, and the gauge coupling factor f. No signal above the standard model expectation is observed in the {mu}{gamma} mass spectrum. In the contact interaction model, they exclude 107 < M{sub {mu}*} < 853 GeV/c{sup 2} for {Lambda} = M{sub {mu}*}; in the gauge-mediated model, they exclude 100 < M{sub {mu}*} < 410 GeV/c{sup 2} for f/{Lambda} = 10{sup -2} GeV{sup -1}. These 95% confidence level exclusions extend previous limits ...
Erectile dysfunction following radical prostatectomy remains a frequent problem despite the development of nerve-sparing techniques. This erectile dysfunction is believed to be neurogenic, enhanced by hypoxia-induced structural changes which result in additional veno-occlusive dysfunction. Recently, daily use of intracavernous vasoactive substances and oral use of PDE5-inhibitors have been clinically studied for treatment of postprostatectomy erectile dysfunction. Since these studies showed benefits of "penile rehabilitation therapy," these effects have been studied in a preclinical setting. We reviewed experimental literature on erectile tissue preserving and neuroregenerative treatment strategies, and found that preservation of the erectile tissue by the use of intracavernous nitric oxide donors or vasoactive substances, oral PDE5-inhibitors, and hyperbaric oxygen therapy improved erectile function by antifibrotic effects and preservation of smooth muscle. ...
A measurement of the t{bar t} production cross section at {radical}s = 1.96 TeV in the dilepton final states using a lepton+track selection and secondary vertex b-tagging is presented. One of the two leptons from the decay of the t{bar t} pair is allowed to be identified only as an isolated track to improve the selection efficiency. The result is combined with a measurement in the t{bar t} {yields} e{mu} final state. The measurements are based on 370 pb{sup -1} of data collected with the D0 experiment at the Tevatron collider. The preliminary cross section obtained in the combined lepton+track and e{mu} channel is: {sigma}{sub t{bar t}} = 8.6{sub -1.7}{sup +1.9}(stat) {+-} 1.1(syst) {+-} 0.6(lumi) pb.
The authors measure the dipion mass spectrum in X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -} decays using 360 pb{sup -1} of {bar p}p collisions at {radical}s = 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity ({sup 3}S{sub 1}, {sup 1}P{sub 1}, and {sup 3}D{sub J}) charmonia decaying to J/{psi}{pi}{sup +}{pi}{sup -}, as well as event C-parity states in which the pions are from {rho}{sup 0} decay. The latter case also encompasses exotic interpretations, such as a D{sup 0}{bar D}*{sup 0} molecule. Only the {sup 3}S{sub 1} and J/{psi} {rho} hypotheses are compatible with the data. Since {sup 3}S{sub 1} is untenable on other grounds, decay via J/{psi} {rho} is favored, which implies C = +1 for the X(3872). Models for different J/{psi}-{rho} angular momenta L are considered. Flexibility in the models, especially the introduction of {rho}-{omega} interference, enable good descriptions of the data for both L = 0 and 1.
This invention is a manufacturing method of a metal-hydrogen alkali battery cell consisting of a positive electrode of metal oxides, alkaline electrolyte solution and a separator containing an amide-radical, wherein the above treating solution is aqueous solution of KOH (or NaOH) which is heated at least at 40 centigrade and the separator is first immersiion-treated and then water-washed and dried. The amide-radical-containing separaator uses a nylon non-woven fabrics. Average molecular weight of nylon 66 is 12,000 - 20,000. In this invention, in order to improve the storage ability and the cycle characteristics which are caused by corrosion of a separator which takes place in the cell after its assembly, the separator is immersed in a hot alkali in order to obtain a non-woven fabric of nylon 66 consisting of alkali-stable high molecular weight portion, which is assembled into a battery. By this, the dissolving of the non-woven fabric and the ...
Penile rehabilitation has been an area of intense study and debate over the last decade. Interest in this topic was stimulated by the observation that erectile dysfunction remained a significant problem after radical prostatectomy despite meticulous nerve-sparing technique. Smooth muscle alterations and fibrotic changes in the penis were identified as the underlying causes of penile atrophy, veno-occlusive dysfunction, and Peyronie's-like changes that were observed after surgery. Initial observations that intracavernous injection therapies used on a regular basis postoperatively resulted in improvements in the return of spontaneous erectile function led to the development of penile rehabilitation protocols. Chronic dosing of oral type V phosphodiesterase inhibitors is now commonly used by urologists after radical prostatectomy despite a lack of convincing evidence from randomized, placebo-controlled clinical trials. Use of local therapies to ...
The EUROTRAC sub-project ''Tropospheric Ozone Research'' (TOR) follows a dual strategy: - Observation of the chemical processes contributing to the oxygen balance directly in the atmosphere; - Establishment of a validated data base for model calculations. Both tasks require simultaneous measurements of a wide range of chemical and meteorological components. In the case of the investigation of the chemical processes, it is also desirable to measure the free radicals directly involved in ozone production. In the project described, a measuring station was set up. For a period of two years and a half, continuous measurements were made of ozone and its chemical precursors (NO, NO_2, NO_y, VOC, CO), as well as other photooxidants (H_2O_2 and organic hydroperoxides, organic nitrates), the photolysis frequency of NO_2, and meteorological parameters (wind, temperature, moisture, aerosols). The station was located on the Schauinsland mountain in the southern Black Forest, at ...
The Green-Chasman lattice, which is the basis for both NSLS storage rings, was conceived with insertion devices in mind. Long, field-free straight sections were provided in the design. The electron optics were chosen so that these sections had zero dispersion and the effects of new magnetic structures placed in these regions would have minimal effect on the emittance of the electron beam. This design concept has been followed by all high-brightness rings which were built subsequent to the NSLS. The X-Ray Ring straight sections also have a very small vertical {beta} function, in addition to the zero dispersion. This was done to optimize the brightness of wiggler sources. There is a further benefit however. The {beta} function determines the beam size and divergence at a particular point in the storage ring lattice. The size is proportional to {radical}{beta} and the divergence is proportional to 1/{radical}{beta}. Thus the electron beam is very ...
The addition of paraquat (methyl viologen) to a growing culture of Escherichia coli K-12 led within 1 hr to a 10- to 20-fold increase in the level of endonuclease IV, a DNase for apurinic/apyrimidinic sites. The induction was blocked by chloramphenicol. Increases of 3-fold or more were also seen with plumbagin, menadione, and phenazine methosulfate. H_2O_2 produced no more than a 2-fold increase in endonuclease IV activity. The following agents had no significant effect: streptonigrin, nitrofurantoin, tert-butyl hydroperoxide, #gamma# rays, 260-nm UV radiation, methyl methanesulfonate, mitomycin C, and ascorbate. Paraquat, plumbagin, menadione, and phenazine methosulfate are known to generate superoxide radical anions via redox cycling in vivo. A mutant lacking superoxide dismutase was unusually sensitive to induction by paraquat. In addition, endonuclease IV could be induced by merely growing the mutant in pure O_2. The levels of endonuclease IV in uninduced or ...
We present a systematic analysis of backward pion photoproduction for the reactions {gamma}p{yields}{pi}{sup 0}p and {gamma}p{yields}{pi}{sup +}n. Regge phenomenology is applied at invariant collision energies above 3GeV in order to fix the reaction amplitude. A comparision with older data on {pi}{sup 0}- and {pi}{sup +}-photoproduction at {theta}=180 indicates that the high-energy limit as given by the Regge calculation could be reached possibly at energies of around {radical}(s){approx_equal}3 GeV. In the energy region of {radical}(s){<=}2.5 GeV, covered by the new measurements of {gamma}p{yields}{pi}{sup 0} p differential cross-sections at large angles at ELSA, JLab, and LEPS, we see no clear signal for a convergence towards the Regge results. The baryon trajectories obtained in our analysis are in good agreement with those given by the spectrum of excited baryons. (orig.)
Environmental Impact Assessment (EIA) must account for legally protected and endangered species. Uncertainties relating to the validity and sensitivity of EIA arise from predictions and valuation of effects on these species. This paper presents a validity and sensitivity analysis of a model (BIO-SAFE) for assessment of impacts of land use changes and physical reconstruction measures on legally protected and endangered river species. The assessment is based on links between species (higher plants, birds, mammals, reptiles and amphibians, butterflies and dragon- and damselflies) and ecotopes (landscape ecological units, e.g., river dune, soft wood alluvial forests), and on value assignment to protected and endangered species using different valuation criteria (i.e., EU Habitats and Birds directive, Conventions of Bern and Bonn and Red Lists). The validity of BIO-SAFE has been tested ...
New partial differential equations (PDEs) for the full order weak schemes of the Langevin simulations are formulated. They are solved recursively in full order series solutions with respect to {radical}(t) (the full order weak Taylor schemes). Arbitrariness involved in the solutions is analyzed and clarified in detail. Specific solutions within some orders are presented as examples of the weak Taylor schemes. These PDEs and their solutions will serve for further developments of efficient higher order Runge-Kutta-like schemes. The similar formulation is possible for the imaginary time Hamiltonian evolution kernels as well. (orig.). 9 refs.
Faced with a changing business emphasis, plus the need to reduce operations and maintenance costs in the North Sea, the Forties Field engineering partnership between BP and Brown and Root recognised the need to make radical changes in its organisational structure. An innovative change management programme was planned and executed inside 12 months with the purpose of right-sizing the Forties Operations Engineering team. Not only has the initiative succeeded in cutting costs by 40 per cent; it has also enhanced the quality of engineering support services supplied to the BP Forties platforms. (author)
Purpose: We present an update analysis of the multiinstitutional Ewing's sarcoma study CESS 86. Methods and Materials: From January 1986 through June 1991, 177 patients with localized Ewing's sarcoma of bone, aged 25 years or less, were recruited. Chemotherapy consisted of four 9-week courses of vincristine, actinomycin D, cyclophosphamide, and adriamycin (VACA) in low-risk tumors (extremity tumors =# 100 cm"3). Local therapy was an individual decision in each patient and was either radical surgery (amputation, wide resection) or resection plus postoperative irradiation with 45 Gy or definitive radiotherapy with 60 Gy (45 Gy plus boost). Irradiated patients were randomized concerning the type of fractionation in either conventional fractionation (once daily 1.8-2.0 Gy, break of chemotherapy) or hyperfractionated split-course irradiation simultaneously with the VACA/VAIA chemotherapy (twice daily 1.6 Gy, break of 12 days after 22.4 Gy and 44.8 Gy, total dose and ...
This article reviews antisocial personality disorder, psychopathy, and violence and develops a three factor model of personality traits. Then a discussion of related personality disorders precedes the development of a categorical two factor model of impulsive versus remorseless violence. A paradigm of proactive, medical, and school based early intervention and prevention is advocated as a useful addition to the reactive detention of criminal justice. Integration of psychological tests, neuroimaging, and genomic data in early childhood and school based intervention strategies to prevent the development of conduct disorder and attenuate criminal propensity inform this approach. PMID:20422651
This short communication aims to update the review of non-nitro radiation sensitizers (Shenoy and Singh 1985) and correct omissions. Work is mentioned and bibliography given for studied of cis-platinum, potassium permanganate, cobalt hexammine, sodium bromide, dimethylsulphoxide, zinc and copper ions, organic nitroxyl free radicals (TAN,TMPN and NPPN + PNAP), halogenated pyrimidines, organic and inorganic iodine containing compounds, diacetyl, acetone and acetophenone, rho-hydrobenzoic acid and its esters, pentobarbitone and secobarbitone, heparin and 9-anilinoacridines, dehydropiandosterone and paraquat. (U.K.).
Nano-materials in which a large fraction of atoms resides within a few atomic layers near the surface can be designed to have novel properties by manipulating their surface parameters. We show that the effective elastic constants of nano-porous/cellular materials can be made to exceed those of the parent materials provided the pore surface elastic parameters satisfy certain conditions. These stiff nano-porous materials herald a radical breakthrough in sandwich-type construction.
Nano-materials in which a large fraction of atoms resides within a few atomic layers near the surface can be designed to have novel properties by manipulating their surface parameters. We show that the effective elastic constants of nano-porous/cellular materials can be made to exceed those of the parent materials provided the pore surface elastic parameters satisfy certain conditions. These stiff nano-porous materials herald a radical breakthrough in sandwich-type construction.
Fractal dimensional analysis was employed to obtain a quantitative measure of the morphology of polymer networks formed by UV irradiation induced polymerization of photo-reactive mesogenic monomers dissolved in a liquid crystal host medium. The fractal dimensions obtained, may be interpreted by polymer network growth following a percolation-like model for monomer concentrations well below the solubility limit. On passing the solubility limit, the polymerization process changes from a (radical chain) solution polymerization to a dispersion polymerization, with fractal dimensions decreasing and suggesting a cluster-cluster aggregation process for monomer concentrations above the solubility limit, similar to the aggregation of colloidal particles.
Decomposition yields of tetracycline hydrochloride (TC.HCl) and chlorotetracycline hydrochloride (ClTC.HCl) in methanol solution saturated with Ar or N/sub 2/O were determined. Rate constants of the reaction esub(s)/sup -/ with some antibiotics were obtained. It was demonstrated by /sup 1/H NMR that the radical formed by degradation of 7-C-Cl group is recombined with the H atoms leading to ClTC.HCl being converted into tetracycline hydrochloride (TC.HCl).
We prove a cosmic no-hair theorem for Bianchi models in power-law inflation. Provided that the potential of an inflaton {phi} is exp({minus}{lambda}{kappa}{phi}) with 0{le}{lambda}{lt} {radical}2/3 , we find that the isotropic power-law solution is the unique attractor for any initially expanding Bianchi-type models except type IX. For Bianchi type IX, this conclusion is also true if the initial ratio of the vacuum energy to the maximum three-curvature is larger than one half.
The author presents a new technique for production of yellow cake with double precipitation, thus solving a series of problems for precipitating uranium with traditional double precipitation. The new technique can not only remove ferric ions and sulfate radicals but also make solid-liquid separation easy, utilize effectively the sulfuric acid produced in ferric ions precipitation process, and increase uranium concentration of leaching liquor. To take it as producing yellow cake will save investment, simplify operation, and cut down the consumption of raw materials and energies. It is more competitive than ion-exchange or solvent extraction in the process of extracting-purifying and preparing yellow cake.
We summarize the predictions of different models for total {gamma}{gamma} cross-sections. The experimentally observed rise of {sigma}{sub {gamma}}{sub {gamma}} with s radical {sub {gamma}}{sub {gamma}}, faster than that for {sigma}{sub p-barp}, {sigma}{sub {gamma}}{sub p} is in agreement with the predictions of the Eikonalized Minijet Models as opposed to those of the Regge-Pomeron models. We then show that a measurement of {sigma}{sub {gamma}}{sub {gamma}} with an accuracy of < or approx. 8-9% (6-7%) is necessary to distinguish among different Regge-Pomeron type models (the different parameterisations of the EMM models) and a precision of < or approx. 20% is required to distinguish the predictions of the EMMs and of those models which treat 'photon like a proton', for the energy range 300< s radical{sub {gamma}}{sub {gamma}} <500 GeV. We further show that the difference in model predictions for ...
The water soluble, photolabile nitrene precursor, azidonaphthalene-2,7-disulfonic acid (ANDS) was encapsulated in small unilamellar, isoelectric (egg PC) or negatively charged (egg PC + dihexadecylphosphate) liposomes. The individual and combined effects of heme-proteins and UV irradiation on the fluorescence of these vesicles under aerobic conditions were studied. Consistent with the catalytic action of heme-proteins on lipid peroxidation and peroxide decomposition, addition of cytochrome c (positively charged) or catalase (negatively charged) to the vesicles elicited immediate formation of a fluorescence band at 470 nm, characteristic of Schiff bases that form from aldehyde byproducts of decomposing hydroperoxides. Ultraviolet irradiation of liposomes caused no significant changes in the fluorescence spectrum, in spite of the radiolysis of ANDS inside the vesicles with consequent formation of nitrene radicals. When isoelectric vesicles were irradiated with UV ...
Two electroactive polymeric arylene bisimides, namely poly[(4,7,10-trioxatrideca-1,13-diyl)-(1,4,5,8-naphthalenetetracarboxylic bisimide-N,N'-diyl)] and its perylene analogue - poly[(4,7,10-trioxatrideca-1,13-diyl)-(3,4,9,10-perylenetetracarboxylic bisimide-N,N'-diyl)] have been synthesized and studied by cyclic voltammetry, UV-vis-NIR as well as Raman spectroeletrochemistry. Contrary to low molecular weight arylene bisimides, which show a clear two electron, double-step electrochemical reduction (neutral form to radical anion and from radical anion to dianion), in the synthesized polymers multielectron transfers are observed, accompanied with a strong electrochromic effect. However, as probed by cyclic voltammetry, their first reduction step is retarded and covers a wider potential range. We attribute this effect to macromolecular nature of the compounds being reduced and their structural inhomogeneity caused by ?-stacking induced ...
The atmospheric chemical behaviour of 2H-Heptafluoropropane (CF[sub 3]CHFCF[sub 3], HFC-227) with respect to its rate and mechanism of degradation in the troposphere has been investigated. The rate coefficient for the reaction of HFC-227 with OH radicals has been determined in direct time resolved experiments using a combination of laser-pulse initiation and LIF. In the temperature range T=298-463 K the Arrhenius expression k(T)=(3.8[+-]0.8) 10[sup -13] exp(-1596[+-]77 K/T) cm[sup 3]/s, which corresponds to k (298 K) = (1.8[+-]0.3) 10[sup -15] cm[sup 3]/s, was found. The mechanism of the atmospheric degradation of HFC-227 has been investigated using both, laser-pulse initiated/time resolved and UV photolysis/FTIR product studies. It is concluded that the major carbonyl products are CF[sub 3]COF and CF[sub 2]O which result from the decomposition of the oxy radical CF[sub 3]CF(O)CF[sub 3] by C-C bound fission. The rate coefficient for this ...
The evaluation of radiotherapy and surgery as exclusive local treatment in comparably selected subgroups of patients with Ewing's sarcoma on the basis of the CESS 86-data. In the German multicenter Ewing's sarcoma study CESS 86, treatment consisted for four 9-week-courses of VACA- or VAIA-chemotherapy plus local therapy. VACA (vincristine, actinomycin D, cyclophosphamide, adriamycin) was given in low-risk extremity tumors with a tumor volume below 100 cm"3. Highrisk patients with central lesions or a tumor volume >100 m"3 received VAIA (ifosfamide instead of cyclophosphamide). Local therapy started after one complete chemotherapy course in week 10. Based on an individual decision in each patient, local therapy was either radical surgery or resection plus postoperative irradiation with 45 Gy or definitive radiotherapy with 60 Gy. Because of poor results with radiotherapy in a preceeding study, it was intended to restrict irradiation to patients with small ...
The gas-phase reaction of benzene with O(3P) is of considerable interest for modeling of aromatic oxidation, and also because there exist fundamental questions concerning the prominence of intersystem crossing in the reaction. While its overall rate constant has been studied extensively, there are still significant uncertainties in the product distribution. The reaction proceeds mainly through the addition of the O atom to benzene, forming an initial triplet diradical adduct, which can either dissociate to form the phenoxy radical and H atom, or undergo intersystem crossing onto a singlet surface, followed by a multiplicity of internal isomerizations, leading to several possible reaction products. In this work, we examined the product branching ratios of the reaction between benzene and O(3P) over the temperature range of 300 to 1000 K and pressure range of 1 to 10 Torr. The reactions were initiated by pulsed-laser photolysis of NO2 in the presence of benzene and ...
Gamma-irradiation of isolated rat liver mitochondria with up to 475 Gy leading to hydrated electrons (G = 1.9, corrected for reaction with solutes), 30 Gy leading to carbohydrate radicals, (G = 5.6), 100 Gy leading to superoxide radicals (G = 6.2), and 130 Gy leading to formate radicals (G = 6.2) showed no effects on the rate of oxygen uptake in various respiratory states, the respiratory control ratio, or the adenosine diphosphate to atomic oxygen ratio. Typical values were 0.020-0.100 nmol O/sub 2/ s/sup -1/ mg protein/sup -1/ for State 1 respiration, 0.25-0.33 nmol O/sub 2/ s/sup -1/ mg protein/sup -1/ for State 4 respiration and 0.65-1.10 nmol O/sub 2/ s/sup -1/ mg protein/sup -1/ for State 3 respiration. Typical respiratory control ratios ranged from 2.0-3.5 for succinate and 4.0-6.5 for a 1:1 glutamate: malate substrate mixture. Adenosine diphosphate to atomic oxygen ratios with succinate as substrate varied from 1.6 ...
An updated listing of the vascular plants of the Hanford Site is provided, along with discussions of how humans may interact with local plants and have influenced the regional flora. Based on examinations of herbarium collections at the Westinghouse Hanford Company, Pacific Northwest Laboratory, Washington State University, and Brigham Young University, 590 vascular plant species have been identified on or near the Hanford Site. This is more than twice the number of species on previously published lists of Hanford Site vascular plants. A review of the plant species that are currently listed as endangered, threatened, sensitive, or otherwise of concern to the Washington State Natural Heritage Program and the Federal Fish and Wildlife Service is included. Color photographs of selected species are included to aid identification. Lists are provided of the Hanford Site plant species that ...
The use of entire plant communities of native species is gaining interest in the green roof industry. Plant communities must be matched with environmental conditions that mimic conditions in their original habitats. Urban built environments do not differ significantly from the rocky outcrops with poor, shallow soil that many plants colonize. This paper provided details of an experiment investigating the impact of plant community structure and species diversity on living roof performance. The aim of the experiment was to determine the impact of species diversity on precipitation interception, nutrient retention, temporal biomass constancy and roof temperature constancy. The diversity treatment included separate monocultures of 8 species in the community, randomly determined mixtures of 4 species, and a mixture of all 8. Functional groups included mosses, liverworts, colonial algae ...
Total mercury content and its distribution in muscles and viscera of male and female blue crab (Callinectes sapidus Rothbum) and deep water pink shrimp (Parapenacus longirostris) collected from the 3 main fishing grounds near the Alexandria coast in the Mediterranean sea was estimated. The results indicate that the mercury content in the muscles of both species differ according to fishing areas, size, sex, and species. More than 75% of total mercury were accumulated in the viscera of both species which indicates that the mercury entered in these organisms via the feed chain. PMID:3696196
During solvent extraction of At"-, [At(H_2O)_2]"+, AtCl, AtCl_2"- as well as of astatine compounds with higher oxidation states like AtO_n"-, the astatine species are changed into astatine of the oxidation state zero at the phase boundary independent on the organic solvent used. At(O) probably reacts with components of the organic phase or with decomposition products formed by chemical reactions or by radiolysis. The extraction coefficients of the astatine species depend on the experimental conditions applied, the redox potential, and on complex forming reactions or associations, resp., occuring in the aqueous phase. (author).
The marine environment is becoming increasingly contaminated by environmental pollutants with the potential to damage DNA, with marine sediments acting as a sink for many of these contaminants. Understanding genotoxic responses in sediment-dwelling marine organisms, such as polychaetes, is therefore of increasing importance. This study is an exploration of species-specific and cell-specific differences in cell sensitivities to DNA-damaging agents in polychaete worms, aimed at increasing fundamental knowledge of their responses to genotoxic damage. The sensitivities of coelomocytes from three polychaetes species of high ecological relevance, i.e. the lugworm Arenicola marina, the harbour ragworm Nereis diversicolor and the king ragworm Nereis virens to genotoxic damage are compared, and dif...
DescriptionOrchids belong to the family Orchidaceae which, with around 20,000 species, is the largest in the Plant Kingdom. Orchids hold a particular fascination because of their spectacular flowers and the rarity of many species- which has increased in recent years as a result of plant collecting, intensification of agriculture and land use changes have placed many species in jeopardy. One feature of orchids that distinguishes them from many other plants is that their seeds are so reduced in size that th [continued...
Ultraconserved elements (UCEs) are sequences that are identical between reference genomes of distantly related species. As they are under negative selection and enriched near or in specific classes...Full Text Available
Mar 30, 2007 ... Tropical forests are home to half the Earth's species, and their trees are an immense standing reservoir of carbon. Deforestation will have ...
... including exotic species such as Hydrilla verticellata (hydrilla), Hygrophila polysperma (hygrophila), Cryptocoryne beckettii (water trumpet), leaving little space ... ...
The protocols presently established for optimum seed storage do not account for the chemical composition of different seed species, the physiological status of the seed, and the physical status of water...Full Text Available
Mitochondrial superoxide production is an important source of reactive oxygen species in cells, and may cause or contribute to ageing and the diseases of ageing. Seven major sites of superoxide...Full Text Available
Diet overlap and niche breadth are well-known species traits from trophic ecology that can assist in explaining how species interact and coexist as well as the ecological mechanisms that influence biodiversity. In the present study, we analyzed the relationships between these trophic variables and indicators of resource availability with some attributes of fish assemblages (species richness, Shannon diversity index, evenness, density and individual body size). The physical and chemical characteristics of the biotopes (topography, water quality and conservation of slopes) were examined to identify possible patterns. Monthly sampling using electrofishing was conducted in 2003 along five streams located in the Cuiab? River watershed. The relationships between environmental variables and attri...
Cultures of chick skin fibroblasts were dissolved in solutions of sodium dodecyl sulphate, and their entire protein content was examined by gel electrophoresis. The most abundant species migrated in...Full Text Available
BackgroundUnderstanding the mechanisms that control rates of disease progression in humans and other species is an important area of research relevant to epidemiology and to translating...Full Text Available
... Congo. It is probable that the type locality Matadi is in error and is the location from ... specimens of this species have been collected between Matadi and Luozi. (click map to view...
The in vivo photochemical activity of photosystem II was inferred from modulated chlorophyll fluorescence and photoacoustic measurements in intact leaves of several plant species (Lycopersicon...Full Text Available
Legionella pneumophila is a gram-negative bacterial species that is ubiquitous in almost any aqueous environment. It is the agent of Legionnaires’ disease, an acute and often...Full Text Available
The Sirtuins are a family of orthologues of yeast Sir2 found in a wide range of organisms from bacteria to man. They display a high degree of conservation between species, in both sequence and function,...Full Text Available
Superfluidity in fermionic systems originates from pairing of fermions, and Bose condensation of these so-called Cooper pairs. The Cooper pairs are usually made of fermions of different species; for example in superconductors they are pairs of electrons with opposite spins. Thus the most favorable situation for pairing and superfluidity is when the two species of fermions that form pairs have the same density. This paper studies the possible superfluid states when the two pairing species have different densities, and show that the resultant states have remarkable similarities to the phases of liquid crystals. This enables us to provide a unified description of the possible pairing phases, and understand the phase transitions among them.
BackgroundSection Calochroi is one of the most species-rich lineages in the genus Cortinarius (Agaricales, Basidiomycota) and is widely distributed...Full Text Available
BackgroundPhotorhabdus luminescens is a Gram-negative luminescent enterobacterium and a symbiote to soil nematodes belonging to the species Heterorhabditis...Full Text Available
Roads function as prime habitats and corridors for invasive plant species. Yet despite the diversity of road types, there is little research on the influence of these types on the spread of invaders. Common ragweed (Ambrosia artemisiifolia), a plant producing large amounts of allergenic pollen, was selected as a species model for examining the impact of road type on the spread of invasive plants. We examined this relationship in an agricultural region of Quebec, Canada. We mapped plant distribution along different road types, and constructed a model of species presence. Common ragweed was found in almost all sampling sites located along regional (97%) and local paved (81%) roads. However, verges of unpaved local roads were rarely (13%) colonized by the plant. A model (53% of variance expla...
Ethane oxidation was studied in ethane-grown resting cells (mycelia) of an Acremonium sp. and in cell-free preparations of such mycelia. From resting cell experiments evidence was found for a pathway...Full Text Available
In order to clarify the taxonomic status and to preserve the stability of the species, a neotype is designated for the tuliptree scale: Coccus liriodendri Gmelin (now Toumeyella...Full Text Available
Rosas-Valdez, R., Choudhury, A. & Prez-Ponce de Len, G. (2011). Molecular prospecting for cryptic species in Phyllodistomum lacustri (Platyhelminthes, Gorgoderidae). -Zoologica Scripta, 40, 296-305. Partial sequences of the 28S ribosomal RNA and cytochrome c oxidase I (COI) genes were compared among populations of a widely distributed and morphologically uniform digenean species in North America, Phyllodistomum lacustri, a parasite characteristically associated with ictalurid catfishes. Specimens were collected from the urinary bladder of ictalurid hosts in six localities of North America, spanning most of the latitudinal range of this freshwater fish group. Sequences of other congeneric species, including a potentially close relative, P.-staffordi, were also obtained and used for comparis...
Weaning of beef calves is usually done abruptly and early compared to the natural weaning of the species, and is associated with simultaneous exposure of calves to a range of social and environmental...Full Text Available
BackgroundBorrelia lonestari infects Amblyomma americanum, the tick species that is the most common cause of tick bites in southeast...Full Text Available
The acute acetoclastic methanogenic inhibition of several inorganic and organic arsenicals was assayed. Trivalent species, i.e., methylarsonous acid and arsenite, were highly inhibitory, with 50% inhibitory...Full Text Available
Inert markers (evaporated tungsten and silver) were used in growth studies of silicides formed both by thermal annealing and by ion mixing in the Ni/Si, Pd/Si, and Cr/Si systems. The markers were initially imbedded inside silicides and backscattering spectrometry was used to determine the marker displacement after different processing conditions. The results obtained in thermal annealing are quite consistent with that found in previous investigations. Ni is the dominant diffusing species in Ni_2Si, while Si is the diffusing species in CrSi_2. In Pd_2Si, both Pd and Si are moving species with Pd the faster of the two. In contrast, in growth of silicides by ion irradiation Si is the faster diffusing species in all three systems.
Inert markers (evaporated tungsten and silver) were used in growth studies of silicides formed both by thermal annealing and by ion mixing in the Ni/Si, Pd/Si, and Cr/Si systems. The markers were initially imbedded inside silicides and backscattering spectrometry was used to determine the marker displacement after different processing conditions. The results obtained in thermal annealing are quite consistent with that found in previous investigations. Ni is the dominant diffusing species in Ni/sub 2/Si, while Si is the diffusing species in CrSi/sub 2/. In Pd/sub 2/Si, both Pd and Si are moving species with Pd the faster of the two. In contrast, in growth of silicides by ion irradiation Si is the faster diffusing species in all three systems.
Background and AimsIt is well known that genome size differs among species. However, information on the variation and dynamics of genome size in wild populations and on the early...Full Text Available
BackgroundIt is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission...Full Text Available
This Memorandum, after summarizing the life cycle of the different species of human schistosome, reviews the present knowledge of the immunology of schistosomiasis. Each stage of the parasite contains...Full Text Available
Pork identification in four types of food products, which are sausages and the casings, bread and biscuits, using species-specific polymerase chain reaction (PCR) detection of a conserved region in the mitochondrial (mt) 12S ribosomal RNA (rRNA) gene was developed. Genomic DNA of the food products were successfully extracted except for the casing samples, where no genomic DNA was detected. The extracted genomic DNA was then subjected to PCR amplification targeting the specific regions of the 12S rRNA gene. The genomic DNA from the food products were found to be of good quality and produced clear PCR products on the amplification of 12S rRNA gene of 387 base pairs (bp) from pork species. The species-specific PCR identification yielded excellent results for identification of pork derivatives...
The diversity of ectoparasites in Southeast Asia and flea-host associations remain largely understudied. We explore specialization and interaction patterns of fleas infesting non-volant small mammals in Bornean rainforests, using material from a field survey carried out in two montane localities in northwestern Borneo (Sabah, Malaysia) and from a literature database of all available interactions in both lowland and montane forests. A total of 234 flea individuals collected during our field survey resulted in an interaction network of eight flea species on seven live-captured small mammal species. The interaction network from all compiled studies currently includes 15 flea species and 16 small mammal species. Host specificity and niche partitioning of fleas infesting diurnal treeshrews and ...
We investigated gathering and cultivating practices and how they complement each other in a rural population of Northwestern Patagonia. We analyzed plant diversity, species similarity, biogeographic origin, and plant use by means of semi-structured interviews and field visits. Pichi Leufu inhabitants used 173 species: 138 cultivated plants, mainly for edible purposes, and 45 wild species principally for medicinal use. Most cultivated species were exotic (91.3%), whereas gathered plants were both native and exotic. While locals maintained vegetable gardens, the adoption of greenhouses improved conditions for certain crops. The integration of novel practices with ancestral knowledge suggests resilient processes in this community, probably reflected in the dynamics of current horticultural an...
Aging is a biological process that affects most cells, organisms and species. Human aging is associated with increased susceptibility to a variety of chronic diseases, including cardiovascular disease,...Full Text Available
The heptageniid mayflies Epeorus latifolium and Epeorus l-nigrus are often the dominant species in the upper and midstream areas of Japanese rivers; as such, they play a significant role in river ecosystems. However, although these two species have been identified using the morphological characteristics of the male in its adult stage, it is impossible to differentiate them in their nymphal stage. We conducted a study to elucidate their distribution pattern, i.e., the current distribution of these two species in the Shinano-gawa River basin, based on quantitative field sampling and genetic analysis of nymphs and also some male adults; for these, it was possible to differentiate between the two species reliably. The data collected from the 30 study sites of the 1-year-long study revealed tha...
... accidentally released from a Soviet military laboratory (Meselson ... Robert Koch and Louis Pasteur worked to introduce ... species (eg, rat, mouse, dog, monkey) for ...
Francisella tularensis is a Gram-negative bacterium capable of causing the zoonotic disease tularaemia in a large number of mammalian species and in arthropods. F. tularensis...Full Text Available
Sufficient genetic diversity exists in Indian tree species to give large genetic gains. Improvement potential, using wild gene resources for selection and breeding is vast as there are over 244 genera and 400 forest tree species in India. Of these over 30 species and 22 genera are of outstanding forestry value. Selective genetic-variation can be lifted from wild populations, multiplied vegetatively or by seed, and planted with controlled germplasm sources. Among the Indian species no less than 74 reproduce by cutting, 11 by layers, 9 by grafting and buding and 104 by root suckers. More than 161 species coppice vigorously. Afforestation techniques of over 170 species have been worked out. Tree genetic approach of survey of natural variability, quick evaluation, selection, conservation multiplication and planting superior variability directly in the field can give ...
... perennials; the dominant species included, in order of their relative importance, Polygonum lapathifolium (C = 0 Heartsease), Arctium minus (C = 0 ...
Background and AimsAnnonaceae are one of the largest families of Magnoliales. This study investigates the comparative floral development of 15 species to understand the basis for...Full Text Available
Reactive chemical transport models developed over the past decade have generally relied on the assumption that local thermodynamic equilibrium is achieved at all times between aqueous species in a given system. Consequently, homogeneous aqueous systems characterized by a number of kinetically slow reactions, particularly problems involving organic species, cannot be satisfactorily modeled. In this study, we present a prototype computer model, KINETRAN, which is designed to handle kinetically-controlled homogeneous reactions in the aqueous phase, along with the transport of the various species involved, through geologic media. 31 refs., 53 figs., 10 tabs.
Periodontitis is an infectious process characterized by inflammation affecting the supporting structures of the teeth. Porphyromonas gingivalis is a major oral bacterial species implicated...Full Text Available
In natural ecosystems, hundreds of species typically share the same environment and are connected by a dense network of interactions such as predation or competition for resources. Much is known about...Full Text Available
Behavioral responses to wind are thought to play a critical role in controlling the dispersal and population genetics of wild Drosophila species1,Full Text Available
Summary 1.-Plant-plant interactions fluctuate between competition and facilitation depending upon ecological conditions and species traits. Facilitative interactions are expected to increase in frequency via associational defences with increasing consumer pressure. The ability of species to cope with competition and/or ecological stressors may alter the outcome of plant-plant interactions. 2.-We conducted a transplant experiment to determine if native and non-native grasses and forbs respond similarly to interactions with Juncus effusus L., an unpalatable benefactor species, along a grazing intensity gradient in two contrasting pasture types: intensively managed and semi-natural. We expected competitive taller, erect species (grasses) and non-natives to obtain stronger facilitative effects...
Ether extracts of cultures of 29 strains representing 6 species of Bacillus, and of individual strains of Escherichia coli, Aerobacter aerogenes, and Pseudomonas...Full Text Available
This is the first record from China of the bopyrid isopod genus Asymmetrione, of which the new species Asymmetrione globifera, a parasite of the hermit crab Dardanus hessii (Miers) in Beibu Gulf and South China Sea, is described. The female A. globifera differs from Asymmetrione nossibensis Bourdon in the shape of its barbula and ornamentation of the first oostegite. A tabulation of the occurrence of all currently known species of Asymmetrione is included. New genus Parasymmetrione is described. The type species, Parasymmetrione tuberculineata, sp. nov., a parasite of Clibanarius corallinus (H. Milne-Edwards) Xisha, is similar in appearance to Asymmetrione spp. but differs, in the female, in not having the propodi of its pereopods produced into sockets and having uniramous uropoda; the mal...
As adulterated and substituted Chinese medicinal materials are common in the market, therapeutic effectiveness of such materials cannot be guaranteed. Identification at species-, strain- and locality-levels,...Full Text Available
The data were collected over three growing seasons. They include density, vegetative biomass, and seed biomass of the two species within the plots. There ... ...
The study of genetic variability within natural populations of pathogens may provide insight into their evolution and pathogenesis. We used a Mycobacterium tuberculosis high-density...Full Text Available
Salt stress elicits betaine accumulation to high levels in species from several diverse dicot families (Chenopodiaceae, Amaranthaceae, Convolvulaceae, Solanaceae, and Asteraceae). FAM-MS studies with deuterated precursors showed that species from all these families synthesize betaine from choline. Enzyme assays and immunotitration data showed that all accumulating species contained betaine aldehyde dehydrogenase (BADH) enzyme activity recognized by antibodies raised against purified BADH isolated from Spinacia oleracea. Immunoblotting indicated that the BADH monomer was in all cases of Mr {approx} 63,000. The similarity of BADH in the different species is consistent with a single evolutionary origin for the betaine pathway. This was supported by the presence in immunoblots of a cross-reacting band at Mr {approx} 63,000 in Magnolia x Soulangiana, a primitive angiosperm.
A tunable diode laser is used to obtain infrared spectra of carbon dioxide in biological materials. The spectral resolution is sufficient to readily distinguish differing isotopic species. The technique may prove useful in clinical tests.
We report the isolation of adherent, clonogenic, fibroblast-like cells with osteogenic and adipogenic potential from the blood of four mammalian species. These cells phenotypically resemble but are...Full Text Available
Due to the use of a limited number of species and subchronic exposures, current ecological hazard assessment processes can underestimate the chronic toxicity of environmental contaminants resulting...Full Text Available
In recent years, there have been major advances in knowledge of Vibrio species and related organisms that are responsible for diarrhoeal diseases, particularly V. cholerae...Full Text Available
Epizootics of neoplasms in freshwater fish species are considered in relation to circumstantial and experimental evidence that suggest that some epizootics of neoplasia of hepatocellular, cholangiocellular,...Full Text Available
The CERL Code was developed to describe the solution chemistry of the water on the steam generating side of PWR reactors. It is designed to calculate the equilibrium species distribution resulting from the interaction of impurities, corrosion products, and additives in the aqueous solution. It calculates the extent of ion-ion interactions, the precipitation of insoluble species and the amount of solute that partitions into the vapor phase when some of the water evaporates. This knowledge of the bulk phase equilibrium distribution of species, especially the pH should be useful in describing the corrosion processes at the solid liquid boundary. The code does not calculate any changes in oxidation states or any rates of reaction. Therefore, it is incapable of calculating the actual corrosion rates. It is anticipated that it will be used as a subprogram of a larger program that will include the redox reactions and the rates of ...
site for reference information. Other recipients include Google's Translator, WikiLeaks, The ICUN Red List of Threatened Species, and the Public Library of Science (PLOS)....
Recent field observations have shown that the atmospheric plumes of quiescently degassing volcanoes are chemically very active, pointing to the role of chemical cycles involving halogen species and...Full Text Available
Arbuscular mycorrhizal (AM) fungi are mutualistic symbionts living in the roots of 80% of land plant species, and developing extensive, below-ground extraradical hyphae fundamental for the uptake of...Full Text Available
BackgroundArtificial duplicates from pyrosequencing reads may lead to incorrect interpretation of the abundance of species and genes in metagenomic studies. Duplicated reads were...Full Text Available
The effects of antimalarials, chloroquine and quinacrine, on the generation of reactive oxygen species were examined both in polymorphonuclear leucocytes and in the xanthine-xanthine oxidase system....Full Text Available
In order to better understand the structure and composition of forest plant communities, we aimed to predict the abundance of understory herbaceous species locally at the stand level and according to different environments. For this, we seeked to model species distributions of abundance at a regional scale in relationship with the local stand structure (canopy openness) and regional soil resources (soil pH). Floristic inventories, performed in different light and soil conditions located in 1202 records of north eastern France, were used to analyze the combined effect of canopy openness and soil pH on the abundance of 12 common western European forest species: Anemone nemorosa, Deschampsia flexuosa, Festuca altissima, Hedera helix, Lamium galeobdolon, Lonicera periclymenum, Molinia caerulea...
A model is described for simulating thermal hydraulic and chemical conditions within fuel crud deposits. Heat transfer takes place by wick boiling in which water flows through the porous deposit and evaporates into steam at the surface of chimneys. The transport and chemistry of dissolved species within the deposit is also modelled. This chemistry includes the equilibrium chemistry of Li/boric acid species, the equilibrium chemistry of Fe/Ni species and the radiolysis chemistry of water. The unique feature of this model is that the chemistry is coupled to the thermal hydraulics via the increase in the saturation temperature with the concentration of dissolved species. This has a profound effect on evaporative heat transfer within thick deposits, leading to conditions that explain the precipitation of LiBO{sub 2} and the possible formation of bonaccordite. The model helps understand several crud scrape ...
BackgroundMycobacterium avium subspecies paratuberculosis causes systemic infection and chronic intestinal inflammation in many species including...Full Text Available
We used microarrays and a previously established linkage map to localize the genetic determinants of brain gene expression for a backcross family of lake whitefish species pairs (Coregonus sp.). Our...Full Text Available
A comparison of the concentration-response effects of inhaled ozone (O/sub 3/) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation studies of this gas. The effect of 4-hour exposure to ozone (O/sub 3/) at concentrations of 0.0, 0.2, 0.5, 1.0, and 2.0 ppm was determined in rabbits, guinea pigs, rats, hamsters and mice. Lavage fluid protein (LFP) accumulation 18 hr after exposure was used as the indicator of O/sub 3/-induced pulmonary edema. All species had similar basal levels of LFP (250-350 ug/ml) when a volume of saline which approximated the total lung capacity was used for lavage of the collapsed lungs. Exponential dose-response curves were seen in all species except guinea pigs, which showed significant increases in LFP at low O/sub 3/ concentrations (0.2 ppm) and a leveling off of response at the higher O/sub 3/ ...
The evolutionary history of the reef fish genus Naso (F. Acanthuridae) was examined using a complete species-level molecular phylogeny of all recognized (19) species based on three loci (one nuclear ETS2 and two mitochondrial 16S, cyt b). This study demonstrates that distinct foraging modes and specialized body shapes arose independently at different times in the evolutionary history of the genus. Members of the subgenus Axinurus, characterized by a scombriform morphology, caudal fin structure and pelagic foraging mode, were consistently placed basal to the remaining Naso species, suggesting that pelagic foraging is plesiomorphic and benthic foraging derived in this genus. We used a genus-level phylogeny (nuclear marker, ETS2), which included several taxa from all other acanthurid genera, to obtain a range of age estimates for the most recent common ancestor of the genus Naso. These age estimates (range of 52-43.3 MY) were ...
DescriptionM291272: Annex A - Electronic data capture of woodland survey records (baseline for studying change and variation in woods) Rationale During the 1980s and 1990s, particularly, much woodland survey was undertaken in England by the Nature Conservancy Council and its successor English Nature. Most of the records are only in paper form and the species data they contain has not been available for further analysis or use in wider context such as species and habitat recording schemes. The aims o [continued...
A ligase chain reaction assay based on a single-base-pair difference in the V9 region of the 16S rRNA gene (16S rDNA) was developed to distinguish between Listeria monocytogenes and other Listeria species....Full Text Available
The application of differential optical absorption (DOA) techniques for the in-situ determination of the chemical composition of coal gasification process streams is investigated. Absorption spectra of relevant molecular species and the temperature and pressure effects on DOA-determined spectral characteristics of these species will be determined and cataloged. A system will be configured, assembled, and tested.
Coatings and sensors having both steric and chemical selectivity. Controlled porosity provides the steric selectivity, whereas chemically tailored film properties, using controlled composition or modification by coupling agents, chemical species replacement, or chemical species within pores, provide the chemical selectivity. Single or multiple layers may be provided.
Sputter-removal rates of overlayer and interfacial species on silicon are analyzed to determine sputtering yields for the species involved. Sputtering yields up to two orders of magnitude lower than those measured for silicon are found, and the results are interpreted in terms of a cascade mixing process which continually reburies much of the overlayer material beyond the escape depth of the sputtered atoms.
Sputter-removal rates of overlayer and interfacial species on silicon are analyzed to determine sputtering yields for the species involved. Sputtering yields up to two orders of magnitude lower than those measured for silicon are found, and the results are interpreted in terms of a cascade mixing process which continually reburies much of the overlayer material beyond the escape depth of the sputtered atoms.
The distribution of Cu, Ni, Co and Mn between an aqueous solution of constant ionic strength and Versatic Acid 911 diluted with benzene was investigated. Only one extracted species of Cu was revealed to have a dimeric structure of the composition (CuR_2.RH)_2, while both monomer and dimer were found in the extraction of Ni, Co and Mn. The curve-fitting method was employed to determine these species, from which the composition of the extracted species was found to be NiR_2.4RH and (NiR_2.2RH)_2, CoR_2.4RH and (CoR_2.2RH)_2, and MnR_2.4RH and (MnR_2.2RH)_2, respectively. The apparent equilibrium constants of the above species and those between monomer and dimer were also determined. The curve-fitting method was proved to be a precise method for determining the equilibrium constants and extracted species. (author).
Selection of suitable species, which will survive the severe environment of low light, cool temperatures, and high winds, poses serious problems to revegetation programs in the Aleutian Islands. Selection must be based on adaptability of plants to the extremes of the Aleutian climate and, as realized more recently, on lack of disruption of the natural ecosystem. This places the emphasis on use of native species in revegetation. Elymus mollis Trin., American dunegrass, a dominant of the Aleutian dune community, was studied to better understand its potential for use in reclamation work. As the species occupies both beach and inland sites, an emphasis was placed on documenting its wide latitude of habitat occurrence. Community composition, dispersal, growth response, ecotypic variation, and nutrient relations were studied at two beach sites and two inland sites on Adak Island in the central Aleutian Islands in the 1977 and ...
We consider a general, neutral, dynamical model of biodiversity. Individuals have i.i.d. lifetime durations, which are not necessarily exponentially distributed, and each individual gives birth independently at constant rate \\lambda. We assume that types are clonally inherited. We consider two classes of speciation models in this setting. In the immigration model, new individuals of an entirely new species singly enter the population at constant rate \\mu (e.g., from the mainland into the island). In the mutation model, each individual independently experiences point mutations in its germ line, at constant rate \\theta. We are interested in the species abundance distribution, i.e., in the numbers, denoted I_n(k) in the immigration model and A_n(k) in the mutation model, of species represented by k individuals, k=1,2,...,n, when there are n individuals in the total population. In the immigration model, we prove that the ...
Propylene and ethylene glycol deicers are commonly used at airports in the US and other countries to remove and retard the accumulation of snow and ice on aircraft. Deicers may not only enter water bodies without treatment, due to excessive storm-related flow, but also may expose terrestrial organisms to high concentrations through surface runoff. Most available toxicity data are for aquatic vertebrates and invertebrate species; this study examined effects on terrestrial and aquatic plants. Terrestrial plant species included both a monocot (rye grass, Lolium perenne) and a dicot (lettuce, Lactuca saliva). Aquatic species included a single cell alga (Selenastrum capricomutum), and an aquatic macrophyte (duckweed, Lemna minor). Glycol deicers were obtained in the formulated mixtures used on aircraft. Pure ethylene and propylene glycol were obtained from Sigma{reg_sign}. Parameters measured included germination, root and shoot ...
Transient experiments in a Temporal Analysis of Products (TAP) Reactor were performed to elucidate the role of surface oyxgen species in the oxidation of benzene to phenol on ZSM-5 type zeolites with nitrous oxide as a selective oxidant. It was shown by puls experiments with nitrous oxide that the mean lifetime of the generated surface oxygen species is between 0.2s at 500 C and about 4.2 s at 400 C. Afterwards the surface oxygen species desorb as molecular oxygen into the gas phase where total oxidation will take place if hydrocarbons are present. Dual puls experiments consisting of a nitrous oxide puls followed by a benzene puls allowed studying the reactivity of the surface oxygen species formed during the first puls. The observation of the phenol formation was impeded due to the strong sorption of phenol. Multipulse experiments were necessary to reach a pseudo steady state phenol yield. (orig.)
Although low-energy ion radiation has been proven to have a wide range of biological effects and led to fruitful achievements as a new mutagenic source for genetic modification, there still exist some disputes about its mutagenic mechanisms because of its short-penetrating property. In present research, Arabidopsis thaliana transgenic for GUS recombination substrate was used to evaluate the genomic instability induced by irradiations of alpha particle (3.3MeV) and Low-energy-Argon ion (30 KeV). A pronounced effects of alpha particle irradiation to Arabidopsis thaliana seedlings and Argon ion irradiation to seeds on the somatic homologous recombination frequency (sHRF) were reported. The sHRFs increased 1.88-fold and 2.42-fold, respectively, which indicated that the short-penetrating radiation could effectively induce the plant genomic instability in either dry seeds or seedlings with active metabolism. The local alpha particle irradiation of root was performed. Result exhibited ...
Anthropogenic nitrogen (N) deposition affects many natural processes, including forest litter decomposition. Saprotrophic fungi are the only organisms capable of completely decomposing lignocellulosic (woody) litter in temperate ecosystems, and therefore the responses of fungi to N deposition are critical in understanding the effects of global change on the forest carbon cycle. Plant litter decomposition under elevated N has been intensively studied, with varying results. The complexity of forest floor biota and variability in litter quality have obscured N-elevation effects on decomposers. Field experiments often utilize standardized substrates and N-levels, but few studies have controlled the decay organisms. Decomposition of beech (Fagus sylvatica) blocks inoculated with two cord-forming basidiomycete fungi, Hypholoma fasciculare and Phanerochaete velutina, was compared experimentally under realistic levels of simulated N deposition at Wytham Wood, Oxfordshire, UK. Mass loss was ...
This paper describes a practical knowledge on gas engine performance and combustion characteristics which are required by experimental studies for two types of developed gas burning engines, i. e. a spark ignited gas engine and a dual fuel engine, and also introduces their practical use and application. As for dual fuel engine performance, a manifold air pressure of about 27% was decreased, a scavenging ratio of 23% reduced and an exhaust temperature at the turbine inlet on 14% was increased at the gas engine operation under the mean effective cylinder pressure of 1.22 MPa in comparison with the diesel operation. Furthemore, empirical data on the effect of excess air ration on the engine performance and combustion characteristics, a risk of knocking during changing over on the dual fuel engine operation, and the rated output in case of using alternate fuel gas were reported. Two spark ignited gas engines with a rated output of 250 PS each using town gas for the ...
The aim of the study is to prepare ionic exchangers using the polymerization of unsaturated polyster with monomeric styrene units in a ratio of 60%: 40% respectively. The type of method involved in this preparation, is called An Emulsion Polymerization. Such type of polymerization was carried out by two techniques: chemical and irradiation techniques. The first techniques requires the formation of free radical monomers by use of methyl Ethy Ketone Peroxide capable of decomposing into free radicals upon heating, while the other technique involves the use of gamma rays (using Co-60 source) capable of activating monomers towards free radical formations. A number of very effective chemical parameters and physical factors were used and investigated throughout the reactions such as: dispersant matrix, viscosity, rate of mixing, and irradiation dose. Besides, the study has included the study of the rate of Resin Beads Swelling ...
The production of ozone in a negative corona discharge fed by carbon dioxide with embedded traces of oxygen and water has been studied. The presence of traces of oxygen in both pure and dry CO_2 leads to an increase in nascent ozone concentrations. In contrast, traces of water vapour (0-800 ppm) are shown to rapidly suppress ozone concentrations with the largest decreases being observed at lowest gas pressures in the discharge (300 Torr). The presence of water vapour did not considerably affect the electrical properties of negative dc corona suggesting that a chemical process is responsible for the ozone loss. We have shown that the addition of water up to a concentration of 1500 ppm has only a marginal effect on the processes of ozone formation but the catalytic cycle of ozone destruction involving OH radicals can be the reason for observed decrease in the total ozone concentration with increasing water concentration.
In the first paper of this series devoted to a structural analysis of a binary metallic glass model, we study a Pd/sub 80/Si/sub 20/ sample obtained by numerical relaxation. We discuss the reproducibility of the method and make a comparison with the experimental interference functions. Then we undertake a microscopic structural analysis from several point of view: we first study the number of neighbours of each type for each type of atoms; secondly, we analyse the structure by means of the radical plane method; at last, we show that it is possible to generalize the five fundamental characteristic units introduced by Bernal, so that we can define the environment of any Si atom without any ambiguity. All these methods reveal a certain tendency towards a prismatic environment for the metalloids.
Women treated of localised stages of cervix cancer have a very good prognosis. But do health care professionals have a tendency to underestimate the potential need for rehabilitation of this group? To be able to answer this question this study aimed to develop knowledge concerning these women's own perception of their health during a long period after surgical cancer treatment. A total of 398 women who underwent radical hysterectomy in the period from the 1 January 1983 to 31 December 2000 participated in the study at Aarhus University Hospital, Skejby in Denmark 2001-2003. All patients initially filled in an internally validated questionnaire. Subsequently a sample of 100 women filled in the questionnaires Short Form -36 and Sense of Coherence to evaluate their self-reported health. Analy...
uv irradiation (365 nm) of air-saturated methanol solutions of 20 drugs absorbing in the 300 to 400 nm region gave rise to oxygen uptake, as determined with a polarographic oxygen electrode. The drugs were tested for photosensitizing capability by either a Type I (free radical) or a Type II (single molecular oxygen) mechanism. This testing was done by the inclusion of either acrylamide or 2,5-dimethylfuran in the irradiated drug solution, with observation of the subsequent polymerization or oxidation, respectively. Phenothiazine and thiazide derivatives appear capable of photosensitization by both mechanisms; promethazine, trifluoperazine, and furosemide show relatively high reactivity. Diazepam (weak), hexachlorophene, aminacrine, pyrilamine, tetracycline, demeclocyline, quinine, and anthracene (strong) react only by a Type II mechanism, with a photosensitizing efficiency increasing in the order given. A correlation appears to exist with reports of in vivo ...
The mutual influence between the PP/PS polymer blend components during UV photodegradation was studied. Polypropylene (PP) and polystyrene (PS) have different photodegradation mechanisms, due to the larger UV absorption of polystyrene and formation of more stable tertiary carbon radicals. To compare the stabilities the kinetics of carbonyl formation was measured in different blend compositions. The results show that polystyrene presented a faster carbonyl formation than polypropylene, while the blends display faster kinetics than the isolated components. The kinetics of carbonyl formation of the blends was a function of polypropylene content. This result is unexpected if one considers the behaviour of each component alone. The kinetics and mechanism of UV degradation can be only explained ...
A three-dimensional, continuous-energy, coupled neutron-gamma Monte Carlo model of the advanced neutron source (ANS) final preconceptual reference core design has been developed using MCNP Version 3b. This model contains the reactor core with control rods, the heavy-water reflector tank with shutdown rods and representative beam tubes, and the outer light-water poor. Eighty homogenized fuel zones per fuel element are used to represent the radical and axial {sup 235}U fuel grading. This model is the most sophisticated, physically accurate reactor physics model of the ANS currently available. The purpose of this summary is to demonstrate the MCNP methods and applications for the ANS.
Subcutaneous involvement frequently occurs in maxillary sinus carcinoma. Radical resection does not include removal of the skin at risk. In standard postoperative wedge-pair treatment plans, the surface dose is dependent upon beam weighting, beam energy, and patient contour. Thermoluminescent dosimetry (TLD) measurements were performed to evaluate the surface dose of patients undergoing postoperative irradiation of maxillary sinus carcinoma following primary resection. When 60 Gy was delivered to isocenter with a 45 degrees wedge pair and 6 MV photons with 1 cm bolus, the subcutaneous tissues at risk received {approximately} 30 Gy. Based upon presented TLD measurements, supplemental electron beam therapy to the subcutaneous tissues if primarily involved should be considered.
New market based approaches are becoming increasingly important as instruments of environmental policy. The two main market approaches, i.e., transferable pollution permits (experimented in America), and 'green' energy surcharges (European philosophy), are described and discussed. An analysis of information on their state of implementation shows that, in the case of the former method, the greatest sources of difficulty arise in the determination of acceptable ceiling levels of emissions, in the distribution of permits among the various polluting firms, and in the legality of granting rights to pollute. Instead, the European experience has evidenced that energy surcharges motivated by environmental policy cannot have an appreciable positive impact on consumers or the economic system in general unless they are accompanied by well defined measures geared towards the promotion or creation of alternative solutions such as to stimulate radical change in ...
A 46-year-old man was referred to us after he presented to his local physician complaining of difficulty eating. Upper gastrointestinal endoscopy revealed a tumor at the esophagogastric junction (EGJ), and moderately differentiated adenocarcinoma was diagnosed from the biopsy findings. Computed tomography (CT) showed apparent enlargement of the pretracheal lymph nodes, the lymph nodes around the bilateral recurrent laryngeal nerves, and the lower thoracic paraesophageal lymph nodes, confirming metastasis. Since the disease was far advanced esophagogastric cancer with marked lymph node metastases throughout the mediastinum, curative resection would have been unlikely. Thus, he was commenced on systemic chemotherapy with cisplatin (90 mg/body, day 8) + S-1 (120 mg/body/day, given for 3 weeks...
We investigate how, and to what extent, morphological complexity of the language influences text classification using support vector machines (SVM). The Croatian-English parallel corpus provides the basis for direct comparison of two languages of radically different morphological complexity. We quantified, compared, and statistically tested the effects of morphological normalisation on SVM classifier performance based on a series of parallel experiments on both languages, carried over a large scale of different feature subset sizes obtained by different feature selection methods, and applying different levels of morphological normalisation. We also quantified the trade-off between feature space size and performance for different levels of morphological normalisation, and compared the resul...
An organic inhibitor for acid corrosion inhibition is described. The inhibitor is a condensation product of a mixture of diethyl- and dibutyl-thiourea with hexamethylenetatramine. This condensation product is preferably made by reacting a mixture of diethyl- and dibutyl-thiourea, in a weight ratio of from 1:5 to 5:1, with 0.1 to 1 mole of hexamethylene tetramine per mole of the thiourea mixture, at temperatures of from 100 to 150 C. It is possible to modify this by using other organic thiourea derivatives containing organic radicals (aliphatic or aromatic) having up to 10 carbon atoms, for example, ditoluyl-thiourea, in addition to the mixture of diethyl- and dibutyl-thiourea, but the amount by weight of these other derivatives must not exceed 20% of the diethyl-dibutyl-thiourea mixture. The advantages of the inhibitor are observed mainly when it is used in hydrofluoric acid solutions. 6 claims.
Childhood cancer survivors at highest risk of developing a secondary malignancy are those with hereditary retinoblastoma. The majority of such secondary cancers will be sarcomas, most commonly of bone. One-third of these occur outside a typical radiation field, commonly in an extremity. Bone sarcoma is also the most commonly reported secondary cancer to develop among survivors of Ewing's sarcoma. In this group, radiation doses greater than 60 Gy as well as alkylating agent chemotherapy have been identified as contributors to the increased risk. The prognosis for patients with a secondary sarcoma has been poor, with few cures reported to date. However, an aggressive, combined modality approach, including radical resection, postoperative radiation, and adjuvant chemotherapy, may improve the survival rate.
The proposed active sites on the catalyst surface in heterogeneous propylene ammoxidation have been successfully modelled by structurally characterized pinacolato W(VI) tert-butylimido complexes. These compounds exist as an equilibrating mixture of amine-bis(imido) and imido-bis(amido) complexes, the position of this equilibrium is dependent on the electronic nature of the glycolate ligand. Both of the C-N bond-forming reactions proposed in recent studies by Grasselli et al. (1) have been reproduced using discrete Group VI d{sup 0} organoimido complexes under mild conditions suitable for detailed mechanistic studies. These reactions are: (1) oxidative trapping of radicals at molybdenum imido sites, and (2) migration of the allyl group from oxygen to an imido nitrogen atom.
The paper proposes a concept of power driver for industrial thermonuclear reactor based on inertial thermonuclear synthesis (ITS). The circuit is based on the application of free electron laser (FEL) as a energy source for thermonuclear target compression which becomes feasible due to the application of a radically new circuit of FEL-amplifier. In the project under consideration the FEL-based laser system operates on the wave length of 0.5 micrometer. The full energy of laser radiation equals 1 MJ. This energy is delivered to the target in the pulse whose length is controlled within the range of 0.1-2 ns. The laser system brightness is 4 x 10"2"2 W cm"-"2. The FEL operating pulse repetition frequency is 40 Hz, full efficiency of electricity conversion into the energy of optical radiation is 11%. 9 refs., 3 figs., 2 tabs.
The primary charge separation in photosynthetic bacteria generates a dimeric bacteriochlorophyll (BChl) cation and a bacteriopheophytin (BPheo) anion which lie within close proximity of each other (approx. 10 A). The two radicals also lie within van der Waals contact on opposite sides of a lone BChl bridging molecule. Spectral changes in the red (Q/sub y/) band of the bridge BChls have been observed on picosecond time scales following excitation of the reaction center (RC) and have been variously attributed to the formation of a BChl anion, to a charge-transfer state, or to electrochromic effects. They present calculations here which suggest that electrochromic effects caused by the photogenerated cation and/or anion can rationalize the optical changes observed in the flash photolyses as well as in trapping experiments.
This study uses an electronic commerce (E-commerce) innovation model to analyze the differences in technological knowledge, business model, and dynamic capability aspects used in Internet-enabled commerce (I-commerce) versus mobile commerce (M-commerce) versus ubiquitous commerce (U-commerce). The results indicate that the innovation from I-commerce to M-commerce is radical, leading to drastic changes in the business model. However, from M-commerce to U-commerce, disruptive changes occur in both technological and business model dimensions. A set of critical dynamic capabilities for each innovation is identified. These results provide great insight for practitioners and scholars for enhancing their understanding of E-commerce innovation, and provide guidelines to help practitioners adapt fr...
Ionizing radiation has been used to treat poultry to remove harmful microorganisms, mainly Salmonella, which contaminates chicken, goose and other fresh and frozen poultry. This microorganism is sensitive to low dose radiation. Thus, irradiating these foods with doses between 1 to 7 kGy results in a large reduction of bacteria. Since it is necessary to determine whether irradiation has occurred and to what extend, this work studied the signal produced by ionizing radiation within the hard crystalline matrix of chicken`s bone to establish a control method. Chicken`s drumsticks were irradiated and bones separated from flesh were lyophilized and milled. ESR spectrum was then obtained. The ESR signal increased linearly with dose over the range 0.25 to 8.0 kGy. Free radicals evaluated during 30 days after irradiation showed stable in this period. (Author).
During this report period, we have obtained a model of montmorillonite clay, and this model has been of great assistance in visualizing how the chemistry of substrate molecules might be altered as it occurs on the surface of the clay. A stereochemical representation of this montmorillonite model is shown. Of particular significance, this model indicates that hydroxyl groups are located in the center of each siloxane ring on the surface of the montmorillonite clay. These hydroxyl groups might serve to bond substrate molecules to the surface of the clay. The next step in our systematic examination of the radical cation-initiated dimerization of plant monomers from the C{sub 6}-C{sub 3} pool of shikimic acid metabolites was to study the dimerization of cinnamic acid and its derivatives. In the next block of research, we examined the reaction of montmorillonite clay (K-10) with methyleugenol. 2 refs.
Recent data on {eta} -meson photoproduction off a proton target in the energy range 2 {<=}{radical}(s){<=} 3 GeV are analyzed with regard to their overall consistency. Results from the ELSA and CLAS measurements are compared with predictions of a Regge model whose reaction amplitude was fixed via a global fit to pre-2000 measurements of differential cross sections and polarization observables for {gamma}p{yields}{eta}p at higher energies. We find that all recent experimental results on differential cross sections for {eta} -meson photoproduction are in good agreement with each other, except for the CLAS data from 2009. However, the latter can be made consistent with the other data at the expense of introducing an energy-dependent renormalization factor. We point out that there are indications in the data for a possible excitation of baryon resonances with masses around 2.1 and 2.4GeV. (orig.)
A comparison of the concentration-response effects of inhaled ozone (O/sub 3/) and phosgene (COCl/sub 2/) in different species of laboratory animals was made in order to better understand the influence of the choice of species in inhalation toxicity studies. The effect of 4-h exposures to ozone at concentrations of 0.2, 0.5, 1.0, and 2.0 ppm, and to COCl/sub 2/ and 0.1, 0.2, 0.5, and 1.0 ppm was determined in rabbits, guinea pigs, rats, hamsters, and mice. Lavage fluid protein (LFP) accumulation 18-20 h after exposure was used as the indicator of O3- and COCl/sub 2/-induced pulmonary edema. All species had similar basal levels of LFP (250-350 mg/ml) when a volume of saline that approximated the total lung capacity was used to lavage the collapsed lungs. Ozone effects were most marked in guinea pigs, which showed significant effects at 0.2 ppm and above. Mice, hamsters, and rats showed effects at 1.0 ppm O3 and above, while ...
The massive star-forming core MM1 of W75N was observed using the Submillimeter Array with #approx#1'' and 2'' spatial resolutions at 217 and 347 GHz, respectively. From the 217 GHz continuum we found that the MM1 core consists of two sources, separated by about 1'': MM1a (#approx#0.6 M_s_u_n) and MM1b (#approx#1.4 M_s_u_n), located near the radio continuum sources VLA 2/VLA 3 and VLA 1, respectively. Within MM1b, two gas clumps were found to be expanding away from VLA 1 at about #+-#3 km s"-"1, as a result of the most recent star formation activity in the region. Observed molecular lines show emission peaks at two positions, MM1a and MM1b: sulfur-bearing species have emission peaks toward MM1a, but methanol and saturated species at MM1b. We identified high-temperature (#approx#200 K) gas toward MM1a and the hot core in MM1b. This segregation may result from the evolution of the massive star-forming core. In the very early phase of star ...
Vermicompost preparations are increasingly used in agricultural practice. There is a possibility, that crop plants are sensitive to negative effect of vermicompost at early stages of development. The aim of the present study was to test the effects of vermicompost on seed germination and seedling growth of different vegetable crop species. Vermicompost substitution inhibited seed germination and seedling growth with almost linear decrease of growth with increasing concentration of vermicopost in the substrate. However, both leaf chlorophyll content and photochemical activity of photosynthesis increased in all crop species with the exception of pea seedlings. Vermicompost extract as a watering solution showed positive effect on growth of bean and pea seedlings. Germination response of vermi...
Biomarkers are biometric measurements that provide critical quantitative information about the biological condition of the animal or individual being tested. In drug safety studies, established toxicity biomarkers are used along with other conventional study data to determine dose-limiting organ toxicity, and to define species sensitivity for new chemical entities intended for possible use as human medicines. A continuing goal of drug safety scientists in the pharmaceutical industry is to discover and develop better trans-species biomarkers that can be used to determine target organ toxicities for preclinical species in short-term studies at dose levels that are some multiple of the intended human dose and again later in full development for monitoring clinical trials at lower therapeutic ...
Benthic biological samples were taken in 1977 from the vicinity of the Farallon Islands radioactive waste disposal sites for characterization of the infaunal macroinvertebrates and foraminifera. A total of 120 invertebrate species were collected, of which 75 species (63 percent) were polychaetes. Forty-three of these polychaete species have not previously been reported from depths greater than 1000m. A total of 1044 macroinvertebrate specimens were collected of which 54 percent were polychates. Only the nematods were present at all six benthic stations, but the community structure was dominated by the polychaetes Tauberia gracilis, Allia pulchra, Chaetozone setosa, and Cossura candida. Living and dead foraminifera were reported. The possible role of polychaetes in bioturbation and in the marine food chain is briefly discussed with respect to the various polychaete feeding mechanisms.
Summary Despite the great interest of red porgy as a new species for Mediterranean aquaculture, its commercial production is constrained by the high incidence of skeletal deformities occurring in this species under culture conditions. Several studies have been conducted to better understand the origin of these anomalies in this species, using different system intensiveness, rotifers enrichment products or rotifers docosahexaenoic acid content. The first study showed that culture intensification increased the number of fish with an extra vertebrae, what was probably related to the different nutritional quality of live preys employed in each treatment, since water temperature, salinity and genetic background were identical for the different batches of fish studied. Total incidence of skeleta...
The primary goal was to address several questions with regard to how soil seed banks change in a successional series. How does the composition of the viable seed bank change, and how does the relationship of the soil seed bank and vegetation change with succession? Can the seed bank be regarded as a potential as a source of seeds for wetland restoration? We collected soil seed bank samples and sampled the vegetation in four different successional stages and used the NMDS (nonmetric multidimensional scaling) to evaluate the relationship of species composition between the seed banks and vegetation. The difference of seed density and species richness in different habitats and soil depths also was compared. Viable seeds of half (37) the species in the early-successional stage were found in all...
A survey of wetlands on the Oak Ridge Reservation (ORR) was conducted in 1990. Wetlands occurring on ORR were identified using National Wetlands Inventory (NWI) maps and field surveys. More than 120 sites were visited and 90 wetlands were identified. Wetland types on ORR included emergent communities in shallow embayments on reservoirs, emergent and aquatic communities in ponds, forested wetland on low ground along major creeks, and wet meadows and marshes associated with streams and seeps. Vascular plant species occurring on sites visited were inventoried, and 57 species were added to the checklist of vascular plants on ORR. Three species listed as rare in Tennessee were discovered on ORR during the wetlands survey. The survey provided an intensive ground truth of the wetlands identified by NWI and offered an indication of wetlands that the NWI remote sensing techniques did not detect.
A survey of wetlands on the Oak Ridge Reservation (ORR) was conducted in 1990. Wetlands occurring on ORR were identified using National Wetlands Inventory (NWI) maps and field surveys. More than 120 sites were visited and 90 wetlands were identified. Wetland types on ORR included emergent communities in shallow embayments on reservoirs, emergent and aquatic communities in ponds, forested wetland on low ground along major creeks, and wet meadows and marshes associated with streams and seeps. Vascular plant species occurring on sites visited were inventoried, and 57 species were added to the checklist of vascular plants on ORR. Three species listed as rare in Tennessee were discovered on ORR during the wetlands survey. The survey provided an intensive ground truth of the wetlands identified by NWI and offered an indication of wetlands that the NWI remote sensing techniques did not detect.
Analytical methods developed to sample and characterize ambient organic aerosols often face the trade-off between long sampling times and the loss of detailed information regarding specific chemical species present. In the work presented here, high-time resolution ambient measurements (3.5 minutes) are achieved by using the Photoionization Aerosol Mass Spectrometer (PIAMS) in conjunction with the mini-Versatile Aerosol Concentration Enrichment System (m-VACES). Aerosol sampling took place for one week at State of Delaware Air Quality Monitoring Site in Wilmington, Delaware in June 2006. The soft, universal ionization scheme of PIAMS allows for identification of various chemical compounds by a signature ion, often the molecular ion. Meteorological data was used to link some species, such as...
The effect of mean daily air temperature (MDT) on flowering rate (the reciprocal of days to flower) was quantified for 18 species of annual bedding plants. Plants were grown in environmental growth chambers at constant air temperature set points of 5, 7.5, 10, 15, 25, or 30^oC and under an irradiance of 160-180mmolm^-^2s^-^1, with a 16-h photoperiod. Nonlinear mathematical equations were developed to predict the effect of MDT on flowering rate and to estimate the base, optimum, and maximum temperatures (Tmin, Topt, and Tmax), which are the temperatures at which flowering rates are zero (low temperature), maximal, and zero once again (high temperature), respectively. The estimated Tmin varied among species and ranged from 1.1^oC in French marigold (Tagetes patula L.) to 9.9^oC in angelonia ...
An hydrazone derivative, 1,2-cyclohexanedione bis-benzoyl-hydrazone (1,2-CHBBH), has been used as a selective reagent for an advanced environmental application consisting of separating the different species of nickel in natural waters by solvent extraction. The effects of pH and reagent concentration on the extraction process were studied, as well as the influence of both organic (humic acids) and inorganic ligands (Cl-). Under natural conditions, organic and inorganic nickel species presented different extraction behaviors, and the variations in extraction yields could be correlated with the concentrations of organic complexes in the samples, allowing the separation of labile and non-labile nickel species in both fresh and marine waters.
Abstract Aim- To explore whether the subspecific genetic entities of Acacia saligna occupy different bioclimatic niches in their native and introduced ranges and whether these niches are predictable using species distribution models (SDMs). Location- Australia, South Africa and the Mediterranean Basin. Methods- Species distribution models were developed in MAXENT using six climatic variables to calculate the climatic suitability of the ranges of A.saligna. We assessed (1) the subspecific niche differences identified by SDMs using measures of niche overlap and model performance; (2) the ability of SDMs to predict the most likely subspecific genetic entities present in South Africa based on comparisons to genetic data; and (3) the ability of SDMs to predict the most likely subspecific geneti...
This is a continuation of our paper [Liu, M., Wang, K., 2010. Persistence and extinction of a stochastic single-species model under regime switching in a polluted environment, J. Theor. Biol. 264, 934-944]. Taking both white noise and colored noise into account, a stochastic single-species model under regime switching in a polluted environment is studied. Sufficient conditions for extinction, stochastic nonpersistence in the mean, stochastic weak persistence and stochastic permanence are established. The threshold between stochastic weak persistence and extinction is obtained. The results show that a different type of noise has a different effect on the survival results. PMID:20816991
Pathway analyses are regarded by National Plant Protection Organizations as a very efficient way to address the risks posed by invasive alien species. Data on import of aquatic plants was obtained from 10 EPPO countries (Austria, Czech Republic, Estonia, France, Germany, Hungary, the Netherlands, Latvia, Switzerland and Turkey) and aggregated in order to consider whether invasive or potentially invasive alien plants could be introduced in the EPPO region through this pathway. This study highlights that this pathway mainly consists of the import of tropical plants for use in aquaria, and which do not represent a risk due to their climatic requirements. However, a few species require thorough attention owing to the threats they cause. Of the 247 species recorded as imported, only 10 are curr...
Summary During a histopathological survey of the geoduck, Panopea abbreviata (Hiatellidae), and the razor clam, Ensis macha (Pharidae), in northern Patagonian gulfs (Argentina), turbellarian worms were found in the intestine lumen. In this work, we described a new species of Paravortex (Platyhelminthes, Graffillidae). We collected the hosts by scuba diving and dissected alive for studying the turbellarians. In this new species, the pharynx continues in a short esophagus and the latter in a saccular intestine. Gravid specimens have from 2 to 8 twin embryos in the parenchyma. A short penis papilla arises from the seminal vesicle and the gonopore presents a strong sphincter. This species resembled P. nicolli Szidat, 1965, which was described paraziting Mytilus edulis platensis in Buenos Aires...
The management programs for invasive species have been proposed and implemented in many regions of the world. However, practitioners and scientists have not reached a consensus on how to control them yet. One reason is the presence of various uncertainties associated with the management. To give some guidance on this issue, we characterize the optimal strategy by developing a dynamic model of invasive species management under uncertainties. In particular, focusing on (i) growth uncertainty and (ii) measurement uncertainty, we identify how these uncertainties affect optimal strategies and value functions. Our results suggest that a rise in growth uncertainty causes the optimal strategy to involve more restrained removals and the corresponding value function to shift up. Furthermore, we also...
One of vector-borne avian protozoa, Leucocytozoon lovati, has been found in the Japanese rock ptarmigans (Lagopus mutus japonicus), the endangered bird species distributed in the alpine regions in Japan. Vector arthropod species of L. lovati has also been estimated as Simuliidae black flies distributed in the same habitat of the host bird, however, possible blood meals of the black flies were not identified yet. To reveal host animals of black flies, we estimated the blood resources by using molecular techniques. Black flies were collected at Mt. Chogatake, one of the alpine regions of Japan in which Japanese rock ptarmigans live in June 2005. The analyzed 144 specimens were morphologically identified into five species including Simulium japonicum (n?=?87), Prosimulium hirtipes (n?=?48), P...
Abstract Development of inhibitors and vaccines that mitigate rumen-derived methane by targeting methanogens relies on knowledge of the methanogens present. We investigated the composition of archaeal communities in the rumens of farmed sheep (Ovis aries), cattle (Bos taurus) and red deer (Cervus elaphus) using denaturing gradient gel electrophoresis (DGGE) to generate fingerprints of archaeal 16S rRNA genes. The total archaeal communities were relatively constant across species and diets, and were less variable and less diverse than bacterial communities. There were diet- and ruminant-species-based differences in archaeal community structure, but the same dominant archaea were present in all rumens. These were members of three coherent clades: species related to Methanobrevibacter ruminan...
Abstract: The cane toad (Bufo marinus), a large, toxic, American anuran, was introduced to Australia in 1935. Populations of many of Australia's reptiles (snakes, varanid lizards, crocodiles) and carnivorous mammals (dasyurid marsupials) have declined because these predators are killed by the toad's powerful toxins. In contrast to these well-studied species, little is known about the cane toads impacts on Australian birds. We reviewed published and unpublished data on behavioral interactions between Australian avian predators and cane toads and collated distributional and dietary information to identify avian taxa potentially at risk from cane toad invasion. Cane toads are sympatric with 172 frog-eating bird species in Australia, and an additional 8 bird species overlap with the predicted ...
The benefits provided by underutilised fruit tree species such as baobab (Adansonia digitata L.) in combating increasing malnutrition and poverty become more apparent as awareness grows regarding concerns of climate change and food security. Due to its multiple uses, its high nutritional and medicinal value, drought tolerance and relatively easy cultivation, baobab has been identified as one of the most important edible forest trees to be conserved, domesticated and valued in Africa. In order to contribute towards the cultivation of the species, suitability of sites in Africa and worldwide was evaluated for potential cultivation using species? locality data and spatial environmental data in MAXENT modelling framework. A total of 450 geo-referenced records of the baobab tree were assembled ...
Long-term fishery datasets can provide valuable insights into fishing histories, and represent a baseline against which to examine current status and plan for future management. For coral reef-associated fisheries, however, such datasets are extremely rare. We analyse a unique 45-year set of landings data on six reef fishes of commercial importance in Cubas coastal fisheries, together with information on management interventions, and examine the likely implications of over-fishing and management on the long-term condition of one grouper (Serranidae) and five snapper (Lutjanidae) species. The data clearly demonstrate differential responses to fishing and management according to the biology of the different species examined. In particular, those species that aggregate most predictably, and a...
30 species belonging to 18 genera were isolated from floor dust of 30 homes in Riyadh. Out of them 16 species and 10 genera were isolated from dust of air conditioners of the same homes. The most common genera in floor dust were Aspergillus, Penicillium and Cladosporium. Aspergillus repens, A. amstelodami, A. versicolor, A. fumigatus, Penicillium purpurogenum, P. crustosum, Cladosporium cladosporoides and C. herbarum were frequently isolated. The most abundant genera in air conditioner dust were Aspergillus and Penicillium. Aspergillus fumigatus, A. ochraceus, A. terreus, Penicillium oxalicium and P. crustosum were most frequent species. PMID:2330766
We report experimental evidence of a previously unseen species-dependent effect in the transverse emittances of momentum-analyzed {sup 28}Si{sup {minus}}, {sup 58}Ni{sup {minus}}, and {sup 197}Au{sup {minus}} negative-ion beams generated by cesium-ion sputtering. The differences in the emittances are found to be principally correlated with differences in the energy spreads in the respective ion beams, which have their origins in the sputter-ejection negative-ion formation process. The experimental equipment and techniques utilized for emittance data acquisition and analysis, and evidence for a species-dependent effect in the emittances and brightnesses of the subject ion beams, are presented in this paper.
Abstract: Environmental synergisms may pose the greatest threat to tropical biodiversity. Using recently updated data sets from the International Union for Conservation of Nature (IUCN) Red List, we evaluated the incidence of perceived threats to all known mammal, bird, and amphibian species in tropical forests. Vulnerable, endangered, and extinct species were collectively far more likely to be imperiled by combinations of threats than expected by chance. Among 45 possible pairwise combinations of 10 different threats, 69%, 93%, and 71% were significantly more frequent than expected for threatened mammals, birds, and amphibians, respectively, even with a stringent Bonferroni-corrected probability value (p= 0.003). Based on this analysis, we identified five key environmental synergisms in t...
Thinning and burning forests established on revegetated mine pits in jarrah (Eucalyptus marginata) forests of south-west Australia is being considered as a management option to accelerate succession in sites with excessive tree densities. To assess the impact of thinning and burning on reptiles and small mammals, we installed trapping grids in eight thinned and burned sites, each paired with untreated controls. Of the eight pairs, four were in rehabilitated sites (planted with nonlocal species) and four were in restored sites (seeded with local species). Thinning and burning had no significant impact on the small mammal community, although Cercatetus concinnus was more abundant in rehabilitated sites. In contrast, thinning and burning significantly increased reptile abundance and species r...
Summary 1.-Traditional views of ecological disturbance emphasize the role that physical disturbances play in reducing competition between populations and maintaining species coexistence. I present an alternative view that employs a simple Lotka-Volterra model to demonstrate how disturbance resistance, disturbance resilience and resource storage can increase competition between individual perennial plants of similar growth form along a resource supply gradient. 2.-In contrasting the growth of individual genets of two hypothetical species, I assumed that traits associated with inherently low module (i.e. plant part) mortality in infertile soils resulted in greater resource storage, but traded off with maximum potential net photosynthesis rates and thus disturbance resilience. 3.-The species ...
Forensic signatures are present in any Pu sample that can determine the sample`s origin: isotopic ratio of Pu, progeny species that grow into the sample, and contaminant species left over from incomplete purification of the Pu in fuel reprocessing. In the context of intelligence information, this can result in attribution of responsibility for the product of clandestine proliferant operations or material smuggled from existing stockpiles. A list of signature elements and what can be determined from them have been developed. Work needs to be done in converting concentrations of signature species into a quantitative forensic analysis, particularly in regard to reactor performance, but this should require only a small effort. A radiochemical analysis scheme has been developed for measuring these nuclides; more work is needed, particularly for determining fission product concentrations. A sample of Pu metal has been analyzed ...
Poaching of wildlife animals for subsistence and commercial purposes has lead to population declines in Africa. In forensic cases, a need exists to identify the species of origin of carcasses, meat or blood. In the study presented here, the mitochondrial COI gene was sequenced to determine the species of unknown samples in three suspect South African forensic wildlife cases. In two cases the unknown samples were identified as originating from domestic cattle (Bos taurus) and in the third case the sample was identified as common reedbuck (Redunca arundinum). This is the first report of the COI sequence of common reedbuck. The study highlights the need for accurate wildlife reference material from each country in order to convict wildlife cases.
Titanium stabilized austenitic steel is sensitive to SCC in the secondary water under the horizontal steam generator operating conditions. SCC was observed under crevice conditions both at the primary collector flanges and the heat exchange tubes. In the crevice environment sulfates and chlorides as aggressive species and silicates and alumino-silicates as ''non-aggressive'' species are present in significant amounts. Local water chemistry parameters were evaluated using the MULTEQ Code. SCC experiments were carried out by rising displacement tests ar 275 deg C in an environment simulating the crevice conditions. Crack growth rate and K{sub IS}8C{sub C} were determined for the environment where contents of some species were from 10{sup 2} to 10{sup 4} times higher than in blowdowns. (authors)
Titanium stabilized austenitic steel is sensitive to SCC in the secondary water under the horizontal steam generator operating conditions. SCC was observed under crevice conditions both at the primary collector flanges and the heat exchange tubes. In the crevice environment sulfates and chlorides as aggressive species and silicates and alumino-silicates as ''non-aggressive'' species are present in significant amounts. Local water chemistry parameters were evaluated using the MULTEQ Code. SCC experiments were carried out by rising displacement tests ar 275 deg C in an environment simulating the crevice conditions. Crack growth rate and K_I_S8C_C were determined for the environment where contents of some species were from 10"2 to 10"4 times higher than in blowdowns. (authors)
The formation constants of species formed in the system H"+"+alanine and VO_"2"+alanine have be determined in aqueous solution for 1.0species with alanine of the type VO_2L and VO_2L_2 The protonation constant of the amino group of alanine has been determined using a computer program which employ a least-squares method. The defence of the protonation of alanine and the stability constant of the species on ionic strength are described by a Debby-huckel type equation.
Old World Bluestems (OWB), introduced from Europe and Asia in the 1920s, recently have begun to raise concerns in the Great Plains. Despite suggestion in the late 1950s that OWB were weedy and negatively impacted biological diversity, they were widely introduced throughout the Great Plains for agricultural purposes. Anecdotal evidence suggests that OWB exhibit invasive characteristics that promote competitive exclusion of native species. The objective of our study was to quantify the competitive abilities of two OWB species (Caucasian bluestem; Bothriochloa bladhii (Retz.) S.T. Blake (=?Bothriochloa caucasica (Trin.) C.E. Hubb.) and yellow bluestem; Bothriochloa ischaemum (L.) Keng) with three native grass species (big bluestem (Andropogon gerardii Vitman), little bluestem (Schizachyrium s...
The lower condition factors for two catfish species in water heated by effluents from APCo's Glen Lyn, Virginia plant as compared to control areas probably is not due to lack of food as evidenced by macroinvertebrate sampling and the fact that only 4.3 percent of the catfish stomachs were empty. Results suggested that young-of-the-year channel catfish were nonselectively eating food organisms present at both control and heated stations. The difference between stomach contents of flatheat catfish from the heated site and fauna available at that site indicated that fish were either moving out of the heated area to feed or were selectively feeding on organisms (particularly mayflies) which were in the substrate or drifted into the heated area. Stomach contents of the two species and distribution and abundance of the macroinvertebrate benthos community are detailed.
Here we present a revision of the fossil record of chitons (Mollusca, Polyplacophora) of Late Pleistocene and Holocene marine deposits of Uruguay and discuss their potential for palaeoenvironmental reconstruction. Chitons were recorded as isolated valves in bivalve- and gastropod-rich assemblages. They are represented by the species Chaetopleura angulata (Spengler), C. isabellei (d'Orbigny), C. asperrima (Gould) and Ischnochiton striolatus (Gray). The last two species are recorded for the first time as fossils not only in Uruguay but also in South America. Exclusively recorded for the Late Pleistocene is the warm water species I. striolatus, whose current southern range limit is located in Santa Catarina, Brazil. Higher temperatures than at present are inferred for the Uruguayan coast duri...
Bothriochloa ischaemum L. and Lespedeza davurica (Laxm.) Schindl. are two co-dominant species of great importance in reducing soil and water loss and maintaining the distinctive natural scenery of the semiarid Loess Plateau of China. Our aim was to determine the growth and interspecific competition between these species under water stress to facilitate the prediction of community succession and guide the selection of appropriate methods of conservation and use in the area. A pot experiment was designed to investigate the effects of water stress and competition on biomass production and allocation, relative competitive ability and water use efficiency of the two species. Bothriochloa ischaemum (a C4 perennial herbaceous grass) was planted in the same pot with L. davurica (a C3 perennial leg...
Abstract Question: How do the diversity, size structure, and spatial pattern of woody species in a temperate (Mediterranean climate) forest compare to temperate and tropical forests? Location: Mixed evergreen coastal forest in the Santa Cruz Mountains, California, USA. Methods: We mapped, tagged, identified, and measured all woody stems (?1 cm diameter) in a 6-ha forest plot, following Center for Tropical Forest Science protocols. We compared patterns to those found in 14 tropical and 12 temperate forest plots. Results: The forest is dominated by Douglas-fir (Pseudotsuga menziesii) and three species of Fagaceae (Quercus agrifolia, Q. parvula var. shrevei, and Lithocarpus densiflorus), and includes 31 woody species and 8180 individuals. Much of the diversity was in small-diameter shrubs,...
Effects of avian gut-passage on seed germination are important to assess the effectiveness of frugivores in woodland regeneration, particularly in biodiversity hotspots that have a high incidence of avian frugivory. We examined the effect of avian gut-passage on seed germination in contrast to seeds that remain uneaten in five shrub species in Mediterranean central Chile and sought to determine the physiological mechanism(s) by which seed germinability is modified. Germination assays were conducted in a glasshouse for five common shrub species of the sub-Andean matorral: Azara dentata (Flacourtiaceae), Schinus polygamus and Schinus molle (Anacardiaceae), Cestrum parqui (Solanaceae), and Maytenus boaria (Celastraceae). We estimated germinability (final percent germination), dormancy length ...
The raw materials used in manufacturing of phosphate fertilizer products were derived from rocks. Rocks contain a remarkable of natural radioactivity. Uranium and phosphorous were originally initiated at the same time of the initiated rocks. The purpose of this research is to investigate solubility of uranium phosphate species at the phosphate fertilizer samples, samples including; raw phosphate material, single super phosphates (SSP) granules and powdered, triple super phosphates (TSP) and phosphogypsum samples were obtained from Abu-Zabal factory in Egypt. Solubility of uranium phosphate species was estimated. It was found that, less than half of the uranium phosphate species are soluble in water. The soluble uranium may be enter into the food chains by plant. Therefore, restriction should be done in order to limit contamination of land and the public.
An efficient micropropagation protocol was established for Cryptocoryne wendtii and Cryptocoryne becketti using shoot tips explants. Multiple shoots were induced from shoot tip explants of both species cultured on agar-gelled as well as liquid MS medium supplemented with 0.5?mg/L BA and 0.2?mg/L IBA (proliferation medium). The multiple shoots of both the species formed on agar-gelled as well as liquid medium were vigorously growing with well-developed roots and leaves after 4?weeks of culture. Highest number of multiple shoots was obtained from shoot tip explants of both the species cultured in liquid proliferation medium after 4?weeks of culture. The shoot tip explants of C. wendtii and C. becketti, that were cultured in liquid proliferation medium (2?weeks) followed by culturing on agar-...
This study concerns the thermotolerance of spores of mesophilic fungi isolated from a tropical semi-arid habitat subject to dry season fire in the Western Ghats, southern India. Among 25 species of Ascomycota isolated from leaf litter, nine were able to grow after incubation in a drying oven for 2h at 100degreeC; the spores of two of these species survived 2h incubation at 110degreeC, and one survived exposure to 115degreeC for 2h. The range of thermotolerance among mesophilic fungi isolated from the leaf litter was surprising: filamentous fungi from other habitats, including species that colonize scorched vegetation after fires and thermophilic forms occurring in self-heating plant composts, cannot survive even brief exposure to such high temperatures. It is possible that the exceptional ...
Purpose: The results of therapy in 288 men with pathologic Stage C prostate cancer who underwent radical retropubic prostatectomy (RRP) were analyzed to determine the effects of adjuvant therapy. Methods and Materials: Twenty-seven of the 288 patients received preoperative neoadjuvant hormonal therapy (leuprolide acetate). Postoperatively, 60 patients received adjuvant radiotherapy (RT) to the prostate bed. Follow-up ranged from 3 to 83 months (median = 32 months). Freedom from failure (FFF) was defined as maintaining a serum PSA level of #<=# 0.3 ng/ml. Results: The FFF was 61% at 3 years and 45% at 5 years for the entire group. The FFF following RRP plus RT was 75% at 3 years and 57% at 5 years as compared to 56% at 3 years and 40% at 5 years for RRP without RT (p = 0.049). The FFF following RRP plus neoadjuvant hormonal therapy was 58% at 3 years and 40% at 5 years as compared to 60% at 3 years and 45% at 5 years following RRP without hormonal therapy (p = ...
Here we report a new method for measuring the heterogeneous chemistry of submicron organic aerosol particles using a continuous flow stirred tank reactor. This approach is designed to quantify the real time heterogeneous kinetics, using a relative rate method, under conditions of low oxidant concentration and long reaction times that more closely mimic the real atmosphere. A general analytical expression, which couples the aerosol chemistry with the flow dynamics in the chamber is developed and applied to the heterogeneous oxidation of squalane particles by hydroxyl radicals (OH) in the presence of O2. The particle phase reaction is monitored via photoionization aerosol mass spectrometry and yields a reactive uptake coefficient of 0.51+-0.10, using OH concentrations of 1-7x108 molec cdot cm-3 and reaction times of 1.5+-3 hours. This uptake coefficient is larger than that found for the reaction carried out under high OH concentrations (~;;1x1010 molec cdot cm-3) and ...
The authors report the observation of B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations from a time-dependent measurement of the B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillation frequency {Delta}m{sub s}. Using a data sample of 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, they find signals of 5600 fully reconstructed hadronic B{sub s} decays, 3100 partially reconstructed hadronic B{sub s} decays, and 61,500 partially reconstructed semileptonic B{sub s} decays. They measure the probability as a function of proper decay time that the B{sub s} decays with the same, or opposite, flavor as the flavor at production, and they find a signal for B{sub s}{sup 0}-{bar B}{sub s}{sup 0} oscillations. The probability that random fluctuations could produce a comparable signal is 8 x 10{sup -8}, which exceeds 5{sigma} significance. They measure {Delta}m{sub s} = 17.77 {+-} 0.10(stat) {+-} 0.07(syst) ...
The reactions of CF{sub 3}O radicals with (1) NO and (2) NO{sub 2} were studied using two different experimental techniques. A laser photolysis/LIF detection method was applied for measuring the rate constants as a function of temperature (T=222-302 K) and total pressure (p{sub tot}=7-107 mbar). Whereas the reaction with (1) NO was found to be independent of temperature and pressure with k{sub 1}=(4.5{+-}1.2) x 10{sup -11} cm{sup 3}s{sup -1}, the reaction with (2) NO{sub 2} was found to be dependent on both of these variables. The temperature dependence of k{sub 2} in the high pressure limit can be given by the expression k{sub 2{infinity}}{sup -}(T)=(8{+-}5) x 10{sup -13} exp ((863{+-}194) K/T) cm{sup 3}s{sup -1}. The product distributions of the two reactions were determined in separate experiments using steady-state photolysis combined with FTIR spectroscopy. For reaction (1) only CF{sub 2}O was found as a reaction product with a yield of 0.93{+-}0.10, ...
Background and purpose: A diagnosis of malignancy and its treatment is a very stressful time for patients and their families. This study was conducted to determine the impact of more intensive written information on patients' anxiety levels. The secondary aim was to determine the impact of this information on patients' satisfaction levels. Materials and methods: This prospective randomized trial consisted of patients with a pathological diagnosis of cancer having radical radiotherapy (RT). Patients were randomized to receive the more intensive information (including written information and a telephone call from the research nurse) or not to receive the more intensive information at the time of their initial consultation with the radiation oncologist. Study questionnaires measuring anxiety (STAI form) were completed prior to their first consultation (baseline) at the time of simulation (pre-RT) and at the completion of radiotherapy. A second questionnaire assessing ...
This paper explores for the first time the post-radiation-induced-graft polymerization on solid substrate using reversible addition-fragmentation transfer (RAFT) mechanism. Radiation-induced graft polymerization onto polymers is a potentially interesting technique to create easily new materials from highly resistant polymers, e.g. surface graft polymerization of acrylic acid (AA) onto poly(vinylidene difluoride) (PVDF) improves its surface properties without losing its excellent mechanical properties. As a consequence of the radical nature of the polymerization processes it is difficult to control molecular weight of grafted chains, and therefore design and standardize the properties of the final product. RAFT polymerization is a suitable method to obtain monodisperse polymers. The ability of the RAFT agents to control the polymer chain length could be an interesting approach to improve the grafted polymers obtained by post-radiation-induced-graft polymerization ...
Extensive research into the treatment and control of Volatile Organic Compounds (VOCs) from semiconductor industry manufacturing processes has identified the need for alternatives to existing combustion devices. Specifically, semiconductor manufacturing design is moving toward exploiting effective, small-scale, abatement control technologies for specific point-of-use (POU) waste streams associated with a particular component or manufacturing tool. The Silent Discharge Plasma (SDP) developed at Los Alamos National Laboratory is a nonthermal plasma technology created by a dielectric-ballasted electrical discharge. Influent gas-phase pollutants are destroyed in the reactor by the free radicals or electrons generated by the plasma. This paper examines the potential for SDP to be used in niche circumstances for POU control of VOC exhaust streams specific to the semiconductor industry. A sensitivity analysis is presented, showing how SDP cost of ownership is affected by ...
A study was conducted to determine the feasibility and the opportunity of photochemical pretreatment on the biodegradation and detoxification of Methyl Tert Butyl Ether (MTBE), Ethyl Tert Butyl Ether (ETBE) and Tert Amyl Methyl Ether (TAME), the most common oxygenates used as octane enhancers in unleaded gasoline. The production, storage, uses and disposal of oxygenates result in an unknown amount of groundwater pollution. Because of their high solubility, MTBE, ETBE and TAME are detected in large portions in saturated zones of aquifers. The biodegradation of these oxygenates is difficult and slow, and information regarding their biodegradability is scarce. Photo-decomposition of oxidants under appropriate UV radiation has been shown to be very effective because the hydroxyl radicals produced possess high oxidation potential. In this study, the H{sub 2}O{sub 2}/UV process was used to generate hydroxyl radicals. Maximal oxygenates transformation ...
A study was conducted to determine the feasibility and the opportunity of photochemical pretreatment on the biodegradation and detoxification of Methyl Tert Butyl Ether (MTBE), Ethyl Tert Butyl Ether (ETBE) and Tert Amyl Methyl Ether (TAME), the most common oxygenates used as octane enhancers in unleaded gasoline. The production, storage, uses and disposal of oxygenates result in an unknown amount of groundwater pollution. Because of their high solubility, MTBE, ETBE and TAME are detected in large portions in saturated zones of aquifers. The biodegradation of these oxygenates is difficult and slow, and information regarding their biodegradability is scarce. Photo-decomposition of oxidants under appropriate UV radiation has been shown to be very effective because the hydroxyl radicals produced possess high oxidation potential. In this study, the H_2O_2/UV process was used to generate hydroxyl radicals. Maximal oxygenates transformation was ...
The side effects of cancer therapy on normal tissues limit the success of therapy. Generation of reactive oxygen species (ROS) has been implicated for numerous chemotherapeutic agents including doxorubicin...Full Text Available
Wildlife Monitoring System Schematic .......................... 40 ...... sentinel species - healthy fish are placed in an environment of water (where they arc not .... The way ir! which data for the fnre mdor study groups will be gathered tor managciacilt ...... Earth Resources Aircraft Program (ERAP) Camera ...
BackgroundThe epidemiology of avian influenza viruses (AIVs) in gulls is only partially known. The role of the world's most numerous gull species, the black-legged kittiwake (Rissa...Full Text Available
Highly polymorphic genes with central roles in lymphocyte mediated immune surveillance are grouped together in the major histocompatibility complex (MHC) in higher vertebrates. Generally, across vertebrate...Full Text Available
Background and AimsIn spatially heterogeneous environments, a trade-off between seedling survival and relative growth rate may promote the coexistence of plant species. In temperate...Full Text Available
Inhibiting insulin/IGF-1 signalling extends lifespan and delays age-related disease in species throughout the animal kingdom. This life-extension pathway, the first to be defined, was discovered through...Full Text Available
Gas exchange between the plant and the environment is severely hampered when plants are submerged, leading to oxygen and energy deficits. A straightforward way to reduce these shortages of oxygen and...Full Text Available
Most insects are thought to fly by creating a leading-edge vortex that remains attached to the wing as it translates through a stroke. In the species examined so far, stroke amplitude is large, and...Full Text Available
A mild reduction in mitochondrial respiration extends the life span of many species, including C. elegans. We recently showed that hypoxia-inducible factor 1 (HIF-1) is required for...Full Text Available
The phylogeny and taxonomy of mammalian species were originally based upon shared or derived morphological characteristics. However, genetic analyses have more recently played an increasingly important...Full Text Available
Mapping the restriction fragments of the Brucella melitensis 16M genome with a new restriction endonuclease, PacI, which cut the DNA into only eight fragments, indicated that this species contains two...Full Text Available
Rapamycin inhibits the mTOR (target of rapamycin) pathway and extends lifespan in multiple species. The tuberous sclerosis complex (TSC) protein is a negative regulator of mTOR. In humans, loss of the...Full Text Available
... being reported (Kisseberth et al., 1984; Ma, 1989; Shore and Douben, 1994). Small mammals are useful indicator species because they have relatively small home ranges allowing a direct tie to the source of ...
Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered...Full Text Available
The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding the role of dilatation and turbulence-chemistry interactions on the progress variable dissipation rate. Compared to the progress variable, the mixing rates of intermediate species is found to be several times greater. The variation of species mixing rates are explained with reference to the structure of one-dimensional premixed laminar flames. According to this analysis, mixing rates are governed by the strong gradients which are imposed by flamelet structures at high Damkoehler numbers. This suggests a modeling approach to estimate the mixing rate of ...
A controlled fire burner was constructed where various natural vegetation species could be used as fuel. The burner was equipped with thermocouples to measure fuel surface temperature and used as a...Full Text Available
Despite the availability of dozens of animal genome sequences, two key questions remain unanswered: First, what fraction of any species' genome confers biological function, and second, are apparent...Full Text Available
There is general consensus that climate change has contributed to the observed decline, and extinction, of many amphibian species throughout the world. ... ...
Simian retroperitoneal fibromatosis (RF) is a vascular fibroproliferative neoplasm which has many morphological and histological similarities to human Kaposi's sarcoma (KS). Like epidemic KS in AIDS...Full Text Available
The Carassius auratus complex in natural populations includes diploid triploid and polyploidy individuals. Diploid individuals belong to the species Carassius auratus...Full Text Available
The biological accumulation of heavy metals and cesium, strontium, and uranium in plants is discussed. The role of nutrient deficiencies and foliar treatments of manganese and iron compounds is described.
Arbuscular mycorrhizal fungi (AMF) are ecologically important root symbionts of most terrestrial plants. Ecological studies of AMF have concentrated on differences between species; largely assuming...Full Text Available
(hidróxido de calcio o cal hidratada) como un plaguicida en un programa de cuarentena para controlar la especie invasora, el coquí. Hawai está preocupada de que estos...
Natural accumulations of skeletal material (death assemblages) have the potential to provide historical data on species diversity and population structure for regions lacking decades of wildlife monitoring,...Full Text Available
The role of pheromone biosynthesis activating neuropeptide (PBAN) in the regulation of pheromone biosynthesis of several female moth species is well elucidated, but its role in the males has been a...Full Text Available
BackgroundThe western African clawed frog Xenopus tropicalis is an anuran amphibian species now used as model in vertebrate comparative genomics. It provides the...Full Text Available
BackgroundA previous study showed for Anopheles gambiae s.s. a gradation of feeding preference on common plant species growing in a malaria holoendemic area in western...Full Text Available
The CYP1A (EROD)-inducing potencies of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3minutes or feet,4,4minutes or feet,5-pentachlorobiphenyl (PCB126) and benzo(k)fluoranthene (B(k)F) were studied in avian embryo livers. TCDD and PCB126 proved to be much more potent as inducers in the chicken than in the other species examined. This finding is consistent with a considerably higher sensitivity of the chicken compared with a number of other avian species to the embryotoxic effects of these compounds. Furthermore, the relative potencies of the tested Ah receptor agonists as CYP1A inducers differed substantially between species. B(k)F and PCB126 showed similar induction potencies in domestic duck embryos, whereas PCB126 is much more potent than B(k)F in the chicken. Also, the potency of PCB126,relative to that of TCDD, was much lower in quail embryo liver in vitro than in chicken embryo liver. Thus, there are large ...
Species of the large family Orchidaceae display a spectacular array of adaptations and rapid speciations that are linked to several innovative features, including specialized pollination syndromes,...Full Text Available
In most insect species, juvenile hormones regulate critical physiological processes such as metamorphosis and reproduction. In insects, these sesquiterpenoids are synthesized by retrocerebral endocrine...Full Text Available
The honeybee has been the most important insect species for study of social behavior. The recently released draft genomic sequence for the bee will accelerate honeybee behavioral genetics. Although...Full Text Available
Arbuscular mycorrhizal fungi (AMF) are obligate biotrophs, known to play an important role in ecological processes. Conventional light microscopy is the most common method used to detect their presence...Full Text Available
BackgroundThe goat (Capra hircus) represents one of the most important farm animal species. It is reared in all continents with an estimated world population of...Full Text Available
Cells of the terrestrial plant species bromegrass (Bromus inermis L.) are not naturally adapted to withstand the hydrostatic pressures encountered in aquatic environments. However,...Full Text Available
Several nematode species have now attained ‘model organism’ status, yet there remain many niches in basic biological inquiry for which nematodes would be ideal model systems of study....Full Text Available
New habitat-based models for spread of hantavirus are developed which account for interspecies interaction. Existing habitat-based models do not consider interspecies pathogen transmission,...Full Text Available
The decline in immune function with aging, known as immunosenescence, has been implicated in evolutionarily diverse species, but the underlying molecular mechanisms are not understood. During aging...Full Text Available