bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sorption behavior of americium onto bentonite colloid
Authors: Iijima Kazuki , Shoji Y. , Tomura T. 
Published: November 2008

AbstractIn the geological disposal system, if colloids can stably exist in groundwater, radionuclides (RNs) might be sorbed onto the colloids and migrate long distance without retardation such as the sorption onto minerals and the matrix diffusion. The distribution coefficient (Rd), which is a measure for sorption onto colloids, is one of the sensitive parameters in evaluation of the effect of colloids on the RN migration. In this study, theRds of Am onto bentonite colloids were evaluated by batch sorption experiments under weakly basic and low ionic strength conditions. Colloidal species of Am seems to be generated even in the absence of bentonite colloids, however, it has less contribution toRd. The obtainedRdvalues are larger than those obtained for larger montmorillonite particles reported in literatures. The difference ofRdis considered to be due to a difference of composition of experimental solution and a difference of reactive site capacity affected by particle size. Site capacities of bentonite colloids are evaluated by acid titration and it is observed that bentonite colloids have about 8 times larger site capacities than bentonite sediments. A relatively simple and generalized mechanistic sorption model, 2SPNE SC/CE model, is applied to estimate theRdfor Am sorption onto bentonite colloids using reaction constants reported in literatures and site capacities obtained in this study. CalculatedRds mostly agree well with corresponding experimental data at pH 8, while,Rds are underestimated at pH 10. Based on the speciation plots, it is probably due to the underestimation of surface complexation reaction.
Vertical distribution of 238Pu, 239(40)Pu, 241Am, 90Sr and 137Cs in Austrian soil profiles
Authors: Srncik M. , Hrnecek Erich , Steier P. , Wallner A. , Wallner Gabriele , Bossew P. 
Published: November 2008

Abstract
The occurrence of 238Pu, 239(40)Pu, 241Am, 90Sr and 137Cs in the region of Nassfeld (Salzburg, Austria) is discussed at four different locations by evaluating a depth profile for each radionuclide. Furthermore, the plutonium separated from the soil samples was measured by Accelerator Mass Spectrometry (AMS) to get information on the isotope ratio 240Pu/ 239Pu. The radiochemical procedure consisted of a Pu separation step from Am and Sr by anion exchange in 8 M HNO3 after oxidation state adjustment to Pu(IV). Am and Sr were coprecipitated with calcium oxalate. Am was separated from Sr by extraction chromatography using TRU-resin. The Sr separation was performed also by extraction chromatography using Sr-resin; after coprecipitation as oxalate, 90Sr was measured in a gas proportional counter. For the determination of 239(40)Pu and 241Am by α-spectrometry thin sources were prepared by microprecipitation with NdF3.
With the respective Pu isotope ratios, it was possible to identify the global fallout as source of the contamination. This was confirmed by the ratio 241Am/239(40)Pu. From the activity ratio 90Sr/ 137Cs, it could be shown that most of these radionuclides stem from the reactor accident in Chernobyl.
Fasciculate rugose corals from Gzhelian and Lower Permian strata, Pequop
Mountains, northeast Nevada
Authors: Stevens Calvin H. 
Published: November 2008

Upper Carboniferous and Lower Permian shallow marine rocks in the Pequop
Mountains of northeastern Nevada contain an abundance of fossils, especially
fusulinids and fasciculate corals. As the composite stratigraphic section in this
area represents the most nearly complete sequence of this type of corals anywhere
in the Cordilleran miogeocline, this study was undertaken to document their
occurrence sequentially. This information should be useful for comparison with
other sections in the miogeocline containing similar corals.
Only one species of Durhamina is present in the
Gzhelian rocks. Durhamina, Heintzella, and
Paraheritschioides occur in the Asselian rocks, and
all of these genera plus Wilsonastraea are present in
the Sakmarian part of the section. Corals in the Artinskian and Kungurian are
represented by an advanced species of Durhamina and the
very advanced durhaminid, Sandolasma.
Newly described species are: Durhamina primitiva, D. snyderi,
Sandolasma perplexa, Heintzella davydovi, Paraheritschioides
nevadaensis, and Wilsonastraea
fraseri.
Biostratigraphy of crinoids from the Wymps Gap member of the Greenbrier
Formation (Mississippian, Chesterian) in northern West Virginia
Authors: Kammer Thomas W. , Springer Gregory S. 
Published: November 2008

Crowns of four crinoid species, Talarocrinus
planus Weller, 1920, Phacelocrinus
longidactylus (McChesney, 1860), Ampelocrinus
mundus? Kirk, 1942, and Phanocrinus
maniformis (Yandell and Shumard, 1847) are reported from the
limestones of the Wymps Gap Member of the Greenbrier Formation in northern West
Virginia. Collectively these species indicate an early Chesterian age for the
Wymps Gap Member, with the occurrence of T. planus
indicating correlation with the Ridenhower (Paint Creek) Formation of the Illinois
Basin. A review of the 17 species currently placed in
Talarocrinus suggests that the
Talarocrinus zone ranges no higher than the
Ridenhower Formation in the Upper Gnathodus bilineatus
conodont zone of the late Visean. The new occurrence of A.
mundus extends its range upwards from the Genevievian substage of
the Chesterian.
Previous studies have used sequence stratigraphy to correlate the Wymps Gap
Member with the lower part of the Union Limestone Formation of the Greenbrier
Group in southern West Virginia, which in turn has been correlated with the
Ridenhower Formation. The occurrence of T. planus in
the Wymps Gap Member provides independent confirmation of the correlations based
on sequence stratigraphy between the Appalachian and Illinois basins. Correlation
of the overlying Reynolds Member of the Mauch Chunk Formation with the Glen Dean
Formation of the Illinois Basin suggests a significant unconformity between the
Greenbrier Formation and Mauch Chunk Formation in northern West Virginia.
Vetupraecan. gen. andMucopraecan. gen. (Cryptodonta, Bivalvia): A reappraisal of Late Devonian bivalves from the Hercynian Facies
Authors: Nagel-Myers Judith , Amler Michael R. W. , Becker R. Thomas 
Published: November 2008

Bivalves from the Late Devonian pelagic or Hercynian Facies of classical regions such as eastern North America and Europe have not been investigated for almost a century.A group of small, radially ribbed bivalves frequently occurs in association with ammonoids and conodonts in pelagic cephalopod limestones and shales of the latest Frasnian and early Famennian. These bivalves have traditionally been assigned to the Late Silurian genusPraecardiumBarrande, 1881. Re-studying the types of the Late Devonian taxa,Cardium?vetustumHall, 1843,Cardiola duplicataMünster, 1840,Praecardium clymeniaeBeushausen, 1895,Praecardium melletesClarke, 1904, andPraecardium multicostatumClarke, 1904 shows that they differ significantly fromPraecardium.As a result, two new genera,Vetupraecan. gen. andMucopraecan. gen, are established. Furthermore, neotypes are designated forCardiola nehdensis, Kayser, 1873 andVetupraeca clymeniae(Beushausen, 1895), and lectotypes are chosen forMucopraeca multicostata(Clarke, 1904) andVetupraeca duplicata(Münster, 1840). These bivalve taxa were widely distributed in the subtropical to tropical, latest Frasnian/early Famennian outer shelf habitats of Laurussia and Gondwana.
Identification of hydroxyl copper toxicity to barley (Hordeum vulgare) root elongation in solution culture
Authors: Wang Xuedong , Ma Yibing , Hua Luo , McLaughlin Mike J. 
Published: November 2008

Abstract
The effect of pH on the acute toxicity of Cu to barley (Hordeum vulgare) root elongation was investigated in solution culture. The results showed that the median effective concentrations (EC50s; i.e., the concentration that reduced root elongation by 50% based on free Cu2+ activity) were not significantly different in the low-pH range from 4.5 to 6.5, but in the high-pH range from 7.0 to 8.0, a significant effect of pH on EC50s was found. The nonlinear relationship between EC50 and H+ activity in the present study indicated that the increased toxicity with increasing pH in solution may not be caused by decreasing H+ competition. When we take account of CuOH+ activities, a good linear relationship (r2 &gt; 0.97) between the ratio of CuOH+ activity to free Cu2+ activity and acute Cu toxicity to barley root elongation was achieved, which indicated that the observed toxicity in the high-pH range may be caused by CuOH+ plus free Cu2+ in solution. Linear-regression analysis suggested CuOH+ had a greater binding affinity than Cu2+ at the biotic ligand sites. The logistic dose–response curve showed that expressing the Cu dose as Cu2+ + 2.92·CuOH+ improved the data fit significantly compared to consideration of the free Cu2+ activity only. Thus, our results suggest CuOH+ was highly toxic to barley root elongation. The enhanced toxicity of CuOH+ therefore needs to be considered when modeling the effect of pH on Cu toxicity to barley for exposures having pH greater than 6.5.
Application of ridge regression to quantify marginal effects of collinear soil properties on phytoaccumulation of arsenic, cadmium, lead, and zinc
Authors: Anderson Richard H. , Basta Nicholas T. 
Published: November 2008

Abstract
Soil properties that mitigate hazardous effects of environmental contaminants through soil chemical sequestration should be considered when evaluating ecological risk from terrestrial contamination. The objective of this research was to identify predominant soil chemical/physical properties that modify phytoaccumulation of As, Cd, Pb, and Zn to the non-hyperaccumulating higher plants: Alfalfa (Medicago sativa L.), perennial ryegrass (Lolium perenne L.), and Japanese millet (Echinochloa crusgalli L.). Transmission coefficients were estimated from a dose–response experiment with the use of aboveground tissue contaminant concentrations and correlated with selected soil property measurements to develop statistical prediction models for soil-specific adjustments to ecological risk assessments. Significant correlations between soil properties and transmission coefficients were observed for all four contaminants. Intercorrelation was also observed among soil properties, including cation exchange capacity (CEC) and soil pH (p = 0.035), CEC and total clay (p = 0.030), organic carbon (OC) and total clay content (p = 0.085), reactive iron oxides (FeOX) and OC (p = 0.078), and reactive Mn oxide (MnOX) and total clay content (p &lt; 0.001). Ridge regression, a technique that suppresses the effects of multicollinearity and enables prediction, was used to assess the marginal contributions of soil properties found to mitigate phytoaccumulation. Prediction models were developed for all four contaminants. Significant variables were FeOX for As or pH, OC, CEC, clay content, or a combination of factors for cationic metal models. Ridge regression provides a powerful alternative to conventional multiple regression techniques for ecotoxicological studies when intercorrelated predictors are experimentally unavoidable, as with soil properties.
Improved scales for metal ion softness and toxicity
Authors: Kinraide Thomas B. 
Published: November 2008

Abstract
Ten scales relating to chemical hardness or softness of metal ions were compiled. These included eight published scales such as those of Pearson, Ahrland, Klopman, and Misono. Another scale consisted of the logs of the solubility products of metal sulfides, and yet another was a consensus scale constructed from —log K values for metal ion binding to seven soft ligands. These 10 scales were normalized and averaged. The resulting consensus scale for softness (σCon) appeared to be superior to any of the 10 scales used in its construction based on correlations among the scales. Other possible indicators of softness were examined, including the standard electrode potential (E0) and the bulk metal density (ρMetal), both of which were also superior to most of the 10 scales just mentioned. Vales for σCon may be computed from E0, ρMetal, and the first ionization potential (IP), R2 = 0.867, for the equation σCon = aE0IP + bρMetal. A consensus scale for toxicity (TCon) derived from studies with many different taxa correlated well (R2 = 0.807) with σCon computed from the preceding equation, but incorporation of ion charge (Z) into the following equation, TCon = aσCon + bσConZ + cZ, increased R2 to 0.923. Substitution of other softness scales for σCon into equations to predict TCon reduced the value of R2. Thus, σCon appears to be a superior scale for metal ion softness and toxicity, the latter being an interactive function of both softness and charge.
Characterization of the structural and functional diversity of indigenous soil microbial communities in smelter-impacted and nonimpacted soils
Authors: Anderson Jennifer A. H. , Hooper Michael J. , Zak John C. , Cox Stephen B. 
Published: November 2008

AbstractA century of mining and smelting activity at the Anaconda Smelter site in Anaconda, Montana, USA, has contaminated the surrounding soils and groundwater with metals. Soil microbial communities from six smelter-impacted sites and a nonimpacted site were compared to determine the long-term effects of a gradient of metal concentrations on microbial activity, biomass, functional diversity (Biolog microtiter plates), and structural diversity (denaturant gradient gel electrophoresis of 16S ribosomal DNA). Microbial activity and biomass were decreased in the smelter-impacted soils. Likewise, the functional and structural diversity of the microbial communities native to the smelter-impacted soils were shifted, relative to the microbial community, from the non-impacted site. These shifts were significantly correlated with soil metal concentration and several soil physicochemical properties (pH, organic matter, NO3, NH4, etc.), which provides evidence of the importance of many environmental variables on microbial community dynamics in soils. Preliminary evidence of functional redundancy was observed within microbial communities native to the smelter-impacted sites, based on overlapping carbon substrate utilization patterns. However, due to culture-based selection bias, redundancy pertains only to a subset of the community and may not be ecologically relevant. Nevertheless, the effects of metal contamination on microbial communities in the present study are pronounced and results provide preliminary insight into the complex relationship between soil microbial community structure and function in anthropogenically disturbed soils.
Periodontal Status of Patients With Metabolic Syndrome Compared to Those Without Metabolic Syndrome
Authors: Khader Yousef , Khassawneh Basheer , Obeidat Basel , Hammad Mohammad , El‐Salem Khalid , Bawadi Hiba , Al‐akour Nemeh 
Published: November 2008

Background: Metabolic syndrome (MeS) is common among Arab populations in Mediterranean countries. This study was conducted to assess the distribution of periodontal parameters among patients with MeS and subjects without MeS in northern Jordan.Methods: A list of all subjects aged ≥25 years who participated in a previous study that aimed to estimate the prevalence of MeS in northern Jordan was obtained. A simple random sample of 78 patients who had MeS and another simple random sample of 78 persons who did not have MeS were selected and invited for dental examination. The oral hygiene of six selected teeth and the periodontal status of all teeth, excluding third molars, were assessed using the plaque index of Silness and Löe, the gingival index of Löe and Silness, probing depth (PD), and clinical attachment level (CAL). Data were analyzed using the general linear model multivariate procedure with average PD, average CAL, percentage of sites with CAL ≥3 mm, and percentage of sites with PD ≥3 mm as outcome variables and MeS and its individual components as predictors.Results: In the multivariate analysis, the severity of periodontal disease, as measured by average PD and average CAL, and the extent of periodontal disease, as measured by the percentage of sites with CAL ≥3 mm and the percentage of sites with PD ≥3 mm, were significantly greater among patients with MeS compared to those without MeS.Conclusions: Patients with MeS displayed more severe and extensive periodontal disease compared to subjects without MeS. Additional large‐scale longitudinal epidemiologic and interventional studies are needed to establish whether periodontal disease is a contributing factor to or a result of MeS.
The Short‐Term Effectiveness of Non‐Surgical Treatment in Reducing Levels of Interleukin‐1β and Proteases in Gingival Crevicular Fluid From Patients With Type 2 Diabetes Mellitus and Chronic Periodontitis
Authors: Correa Fernanda O.B. , Gonçalves Daniela , Figueredo Carlos M.S. , Gustafsson Anders , Orrico Silvana R.P. 
Published: November 2008

Background: This study aimed to compare the effectiveness of non‐surgical periodontal treatment in improving periodontal status and reducing gingival crevicular fluid (GCF) levels of interleukin (IL)‐1β and IL‐18, elastase activity, and matrix metalloproteinase (MMP)‐‐8 and ‐‐9 in periodontitis patients with and without type 2 diabetes mellitus (T2DM).Methods: Twenty‐three patients with T2DM (diabetes group) and 26 systemically healthy subjects (control group) with chronic periodontitis participated in this study. The clinical examination included visible plaque index, gingival bleeding index, probing depth, clinical attachment level, and bleeding on probing. GCF samples were collected from five or six deep sites to evaluate the levels of IL‐1β and −18, elastase, and MMP‐8 and −9. Shallow sites were analyzed for IL‐1β and elastase. The glycemic control was analyzed by the concentration of glycated hemoglobin (HbA1c). The subjects received non‐surgical periodontal treatment and were reexamined 90 days later.Results: All clinical parameters showed a significant improvement after treatment, which was accompanied by a significant reduction in IL‐1β, elastase activity, and MMP‐8 and −9 levels in deep sites. The shallow sites also showed significant reductions in IL‐1β and elastase activity levels. Treatment did not significantly reduce HbA1c concentrations in patients with T2DM.Conclusions: Non‐surgical periodontal treatment was effective in reducing the levels of IL‐1β, elastase activity, and MMP‐8 and −9 in GCF from diabetes and control groups. Patients with T2DM showed less reduction only in elastase activity in shallow sites compared to controls. This reduction was associated with improvement of the clinical periodontal status.
Optimization of sample handling and processing for the carbon 13-labeled aminopyrine demethylation blood test and determination of a reference range for test results in healthy dogs
Authors: DeBiasio John V. , Steiner Jörg M. , Suchodolski Jan S. , Read Sarah A. 
Published: November 2008

Abstract
Objective—To determine the optimal sample handling and processing conditions for the carbon 13 (13C)-labeled aminopyrine demethylation blood test (ADBT; phase 1) and determine the reference range for test results (phase 2) in apparently healthy dogs.
Animals—44 apparently healthy dogs (phase 1, 19 dogs; phase 2, 44 dogs).
Procedures—In phase 1, a blood sample from each dog was collected before and 45 minutes after (day 0) IV administration of 13C-labeled aminopyrine (2 mg/kg); aliquots were immediately transferred into tubes containing sodium heparin and hydrochloric acid (samples A and B), sodium heparin alone (samples C, D, and E), or sodium fluoride (sample F). Hydrochloric acid was added to samples C through F at days 7, 14, 21, and 21, respectively. The baseline and 45-minute samples' absolute 13C:12C ratios were determined via fractional mass spectrometry on day 0 (control sample A) or 21 (samples B through F) and used to calculate the percentage dose of 13C recovered in CO2 extracted from samples (PCD). In phase 2, blood samples from each dog were collected into tubes containing sodium fluoride and processed within 3 weeks.
Results—Compared with the control sample value, PCDs for samples C through E differed significantly, whereas PCD in sample F did not. The 13C-ADBT–derived PCD reference range (central 95th percentile) for apparently healthy dogs was 0.08% to 0.2%.
Conclusions and Clinical Relevance—Glycolytic CO2 production in canine blood samples collected during 13C-ADBTs was sufficiently inhibited by sodium fluoride to allow delayed sample analysis and avoid transportation of hydrochloric acid–treated samples.
Comparison of the anesthetic efficacy and cardiopulmonary effects of continuous rate infusions of alfaxalone-2-hydroxypropyl-β-cyclodextrin and propofol in dogs
Authors: Ambros Barbara , Duke-Novakovski Tanya , Pasloske Kirby S. 
Published: November 2008

Abstract
Objective—To compare the cardiopulmonary effects of continuous rate infusions (CRIs) of alfaxalone-2-hydroxypropyl-β-cyclodextrin (HPCD) and propofol in healthy dogs.
Animals—6 young adult medium-sized healthy crossbred dogs.
Procedures—A crossover design was used with a washout period of 6 days between anesthetic treatments. Each dog was sedated with acepromazine (0.02 mg/kg, IV) and hydromorphone (0.05 mg/kg, IV). Anesthesia was induced with propofol (4 mg/kg) or alfaxalone-HPCD (2 mg/kg). After endotracheal intubation, anesthesia was maintained with the same agent (propofol, 0.25 mg/kg/min; alfaxalone-HPCD, 0.07 mg/kg/min) for 120 minutes. Dogs spontaneously breathed 100% oxygen. Measurements included end-tidal partial pressure of carbon dioxide, heart and respiratory rates, mean arterial blood pressure, thermodilution-derived cardiac output, and body temperature. Paired arterial and mixed venous blood samples were collected for determination of blood pH, PaCO2, and PaO2. Data were recorded prior to induction; 5, 15, 30, 60, 90, and 120 minutes after induction of anesthesia; and 20 minutes after stopping the CRI, when feasible. Stroke volume and systemic vascular resistance were calculated. Quality of anesthetic induction and recovery and interval to recovery were recorded.
Results—Both propofol and alfaxalone-HPCD produced excellent induction of anesthesia, maintenance, and recovery. Respiratory depression was evident with both anesthetics. Clinically acceptable, mild hemodynamic changes were similar for both anesthetics.
Conclusions and Clinical Relevance—Alfaxalone-HPCD produced clinically acceptable anesthetic quality and hemodynamic values ideal for use as a CRI. Ventilation may need to be supported if hydromorphone is used at these propofol and alfaxalone-HPCD infusion rates.