bluuebunny/crossref_metadata_2025 huggingface dataset:
Intra- and Intersubject Whole Blood/Plasma Cannabinoid Ratios Determined by 2-Dimensional, Electron Impact GC-MS with Cryofocusing
Authors: Schwilke Eugene W , Karschner Erin L , Lowe Ross H , Gordon Ann M , Cadet Jean Lud , Herning Ronald I , Huestis Marilyn A
Published: March 2009

Background: Whole-blood concentrations of Δ9-tetrahydrocannabinol (THC), 11-hydroxy-THC (11-OH-THC), and 11-nor-9-carboxy-THC (THCCOOH) are approximately half of those in plasma due to high plasma protein binding and poor cannabinoid distribution into erythrocytes. Whole blood is frequently the only specimen available in forensic investigations; controlled cannabinoid administration studies provide scientific data for interpretation of cannabinoid tests but usually report plasma concentrations. Whole-blood/plasma cannabinoid ratios from simultaneously collected authentic specimens are rarely reported.

Methods: We collected whole blood for 7 days from 32 individuals residing on a closed research unit. Part of the whole blood was processed to obtain plasma, and the whole blood and plasma were stored at −20 °C until analysis by validated 2-dimensional GC-MS methods.

Results: We measured whole-blood/plasma cannabinoid ratios in 187 specimen pairs. Median (interquartile range) whole-blood/plasma ratios were 0.39 (0.28–0.48) for THC (n = 75), 0.56 (0.43–0.73) for 11-OH-THC (n = 17), and 0.37 (0.24–0.56) for THCCOOH (n = 187). Intrasubject variability was determined for the first time: 18.1%–56.6% CV (THC) and 10.8%–38.2% CV (THCCOOH). The mean whole-blood/plasma THC ratio was significantly lower than the THCCOOH ratio (P = 0.0001; 4 participants’ mean THCCOOH ratios were >0.8).

Conclusions: Intra- and intersubject whole-blood/plasma THC and THCCOOH ratios will aid interpretation of whole-blood cannabinoid data.
Heterogeneous Nuclear Ribonucleoprotein H1, a Novel Nuclear Autoantigen
Authors: Van den Bergh Karolien , Hooijkaas Herbert , Blockmans Daniel , Westhovens René , Op De Beéck Katrijn , Verschueren Patrick , Dufour Diana , van de Merwe Joop P , Fijak Monika , Klug Jörg , Michiels Georges , Devogelaere Benoit , De Smedt Humbert , Derua Rita , Waelkens Etienne , Blanckaert Norbert , Bossuyt Xavier
Published: March 2009

Background: Serum samples from patients with autoimmune connective tissue diseases that show a finely speckled antinuclear antibody (ANA) on indirect immune-fluorescence often have antibodies against unknown nuclear target antigens. To search for such autoantigens we applied a proteomic approach using sera from patients with a high ANA titer (≥640) and finely speckled fluorescence but in whom no antibodies to extractable nuclear antigens (ENA) could be identified.

Methods: Using an immunoproteomics approach we identified heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1) as a novel nuclear target of autoantibody response.

Results: Recombinant rat hnRNP H1 reacted in Western blot analyses with 48% of 93 sera from patients with primary Sjögren syndrome and with 5.2% of 153 sera from patients with other connective tissue diseases (diseased controls). For comparison, the diagnostic sensitivity and specificity of anti–Sjögren syndrome A (SSA) antibodies for primary Sjögren syndrome in the same patient cohort were 88.2% and 76.3%, respectively. Interestingly, 5 of 11 primary Sjögren syndrome patients with no anti-SSA or anti-SSB antibodies had anti–hnRNP H1 antibodies. Anti–hnRNP H1 antibodies were preabsorbed by hnRNP H1, as demonstrated by indirect immunofluorescence. In an evaluation of the presence of anti–hnRNP H1 antibodies in 188 consecutive samples submitted to the clinical laboratory with positive ANA (titer ≥160), anti–hnRNP H1 antibodies were found in 3 of 7 (2 primary and 5 secondary) Sjögren syndrome patients and in 8.3% of the diseased controls.

Conclusions: HnRNP H1 is a newly discovered autoantigen that could become an additional diagnostic marker.
Prostate Specific Antigen Detection Using Microgapped Electrode Array Immunosensor with Enzymatic Silver Deposition
Authors: Huang Yong , Wang Tai-Hong , Jiang Jian-Hui , Shen Guo-Li , Yu Ru-Qin
Published: March 2009

Background: Analysis of trace proteins plays an essential role in the fields of biomedical research and clinical diagnosis. Development of methods for the detection of proteins at very low concentrations has historically been a challenge in immunochemistry. We have developed an electrical immunosensor for the detection of prostate specific antigen (PSA).

Methods: The electrical immunosensor uses a microgapped interdigitated electrode array (MGIDEA) based on enzymatic silver deposition reaction. The deposition of silver was dispersed over the microgaps and allows the microgapped interdigitated electrodes to be electrically connected, resulting in an increase in electrical conductance of MGIDEA that is used to quantify the analyte concentration. We used this electrical immunosensor to measure PSA in human serum samples from patients with prostate diseases.

Results: This electrical immunosensor exhibited a linear response with PSA concentrations over a 6-decade range from 1.0 pg/L to 1.0 μg/L, with detection limit of 0.9 pg/L. PSA concentrations using this immunosensor agreed within 10% of those obtained using a commercial chemiluminescent immunoassay.

Conclusions: The MGIDEA method has characteristics (analyte specific, low background, low limit of detection) that provide potential for molecular detection in various biomedical areas.
Activity Assays and Immunoassays for Plasma Renin and Prorenin: Information Provided and Precautions Necessary for Accurate Measurement
Authors: Campbell Duncan J , Nussberger Juerg , Stowasser Michael , Danser A H Jan , Morganti Alberto , Frandsen Erik , Ménard Joël
Published: March 2009

Background: Measurement of plasma renin is important for the clinical assessment of hypertensive patients. The most common methods for measuring plasma renin are the plasma renin activity (PRA) assay and the renin immunoassay. The clinical application of renin inhibitor therapy has thrown into focus the differences in information provided by activity assays and immunoassays for renin and prorenin measurement and has drawn attention to the need for precautions to ensure their accurate measurement.

Content: Renin activity assays and immunoassays provide related but different information. Whereas activity assays measure only active renin, immunoassays measure both active and inhibited renin. Particular care must be taken in the collection and processing of blood samples and in the performance of these assays to avoid errors in renin measurement. Both activity assays and immunoassays are susceptible to renin overestimation due to prorenin activation. In addition, activity assays performed with peptidase inhibitors may overestimate the degree of inhibition of PRA by renin inhibitor therapy. Moreover, immunoassays may overestimate the reactive increase in plasma renin concentration in response to renin inhibitor therapy, owing to the inhibitor promoting conversion of prorenin to an open conformation that is recognized by renin immunoassays.

Conclusions: The successful application of renin assays to patient care requires that the clinician and the clinical chemist understand the information provided by these assays and of the precautions necessary to ensure their accuracy.
Cassification of first-order flexible regular bicycle polygons
Authors: Connelly Robert , Csikós Balázs
Published: March 2009

A bicycle (
n
,
k
)-gon is an equilateral
n
-gon whose
k
-diagonals are equal. S. Tabach-nikov proved that a regular
n
-gon is first-order flexible as a bicycle (
n
,
k
)-gon if and only if there is an integer 2 ≦
r
≦
n
-2 such that tan (π/
n
) tan (
kr
π/
n
) = tan (
k
π/
n
) tan (
r
π/
n
). In the present paper, we solve this trigonometric diophantine equation. In particular, we describe the family of first order flexible regular bicycle polygons.
Asymptotic approximations for coupon collectors
Authors: Pósfai Anna , Csörgő Sándor
Published: March 2009

A collector samples with replacement a set of
n
≧ 2 distinct coupons until he has
n
−
m
, 0 ≦
m
<
n
, distinct coupons for the first time. We refine the limit theorems concerning the standardized random number of necessary draws if
n
→ ∞ and
m
is fixed: we give a one-term asymptotic expansion of the distribution function in question, providing a better approximation of it, than the one given by the limiting distribution function, and proving in particular that the rate of convergence in these limiting theorems is of order (log
n
)/
n
.
Exact order of the Lebesgue constants for bivariate Lagrange interpolation at certain node-systems
Authors: Vecchia Biancamaria , Mastroianni Giuseppe , Vértesi Péter
Published: March 2009

The authors investigate two sets of nodes for bivariate Lagrange interpolation in [−1, 1]
2
and prove that the order of the corresponding Lebesgue constants is (log
n
)
2
.
The Rationale for Monitoring Invasive Plant Populations as a Crucial Step for Management
Authors: Maxwell Bruce D. , Lehnhoff Erik , Rew Lisa J.
Published: March 2009

Many land managers are faced with trying to optimize management of invasive plant species based on budget constraints and lack of knowledge of the true potential of the species. Generally, “early detection rapid response” (EDRR) is the assumed best management strategy and tends to drive management regardless of the invasion stage or possible variation in the invasion potential of the population. We created a simulation model to evaluate the optimal management strategy to reduce the rate of invasion of nonindigenous plant species. The strategies were specifically chosen to assess the value of information from monitoring populations. We compared four management strategies and a no-management control over a 20-yr period in the context of a management area: (1) managing a fixed number of populations at random each year (EDRR random), (2) managing an equivalent number of populations along a road each year (EDRR road), (3) managing half of the fixed populations that were determined by monitoring to be sources of new populations (monitoring every year), and (4) managing an equivalent set of source populations only on even years, leaving the odd years for monitoring (monitoring every other year). EDRR random location without regard to population invasion potential, and monitoring every year targeting management on populations determined to be invasive (sources for new populations), were the most successful strategies for reducing the increase in total number of populations. The model simulations suggest that managers could dedicate 50% of their management time to monitoring without risk of accelerating invasions or reducing the impact of their weed management program.
Geographic Patterns of Interspecific Hybridization between Spotted Knapweed (Centaurea stoebe) and Diffuse Knapweed (C. diffusa)
Authors: Blair Amy C. , Hufbauer Ruth A.
Published: March 2009

Hybridization between species has the potential to change invasion dynamics. Field observations suggest that spotted knapweed and diffuse knapweed, two ecologically and economically destructive invasive plants, hybridize in their introduced range. As a first step towards understanding whether hybridization has affected the dynamics of the invasion of these species, we conducted field surveys in the introduced (North American) and native (European) ranges to discern patterns of hybridization and measured fitness-related traits among field hybrids and parental species. In North America we detected plants with hybrid morphology in 97% of the diffuse knapweed sites (n= 40); such hybrid plants were taller and more often exhibited polycarpy than plants with typical diffuse knapweed morphology. Hybrids were not detected in North American spotted knapweed sites (n= 22). In most regions surveyed in Europe, diffuse knapweed and spotted knapweed were isolated from each other and existed as distinct, nonhybridizing species. However, in Ukraine, the two species frequently coexisted within a site, resulting in hybrid swarms. On average, the plants from the North American diffuse knapweed sites (including plants with both diffuse and hybrid morphology), were larger than the apparently pure diffuse knapweed in the native range. The cross-continental patterns of hybridization likely are explained by differences in cytology. It recently has been confirmed that the spotted knapweed in North America is tetraploid whereas the diffuse knapweed is diploid. Genetic incompatibilities associated with these two cytotypes likely prevent ongoing hybridization. We hypothesize that hybrid individuals were introduced to North America along with diffuse knapweed. Because plants with hybrid morphology are found in nearly all North American diffuse knapweed sites, the introduction of hybrids likely occurred early in the invasion of diffuse knapweed. Thus, although the presence of hybrids might facilitate the ongoing invasion of diffuse knapweed into North America, elevated concern regarding their presence might not be warranted. Because such individuals are not likely to represent a new hybridization event, currently effective management strategies used in diffuse knapweed sites should not need alteration.
Land Manager and Researcher Perspectives on Invasive Plant Research Needs in the Midwestern United States
Authors: Renz Mark , Gibson Kevin D. , Hillmer Jennifer , Howe Katherine M. , Waller Donald M. , Cardina John
Published: March 2009

In 2006, the Midwest Invasive Plant Network's Research Committee conducted a web-based survey to help identify research needs and interactions between land managers and researchers working to manage invasive plants in the Midwest. Of 192 responses, 30% identified themselves as researchers and 70% identified themselves as managers. Researchers and managers rated working together on invasive plant issues as high or medium in importance, but neither group rated the current level of cooperation as high, with over 90% describing current cooperation as low or medium. Both groups self-associate, with 89% of researchers working with other researchers and 77% of managers working with other managers. “Lack of time” and “lack of money” were the main issues limiting researchers and land managers from working more closely together: money was a greater constraint for researchers and time was more important for land managers. To help researchers and land managers work more effectively together, both groups favored opportunities to develop research-based projects at land managers' sites, with funding from a cooperative grant program. Open-ended responses suggest that on-site experiments and demonstrations of management methods could help researchers and land managers interact more effectively. Researchers rated basic biology as more important than land managers did, but neither group judged testing theories of invasion as a high priority. “Social/political factors” and “risk assessment” were viewed as less important despite their clear relevance in the introduction and spread of invasive plants.
Conclusions from the post-incident review for Ulley dam
Authors: Mason Peter J. , Hinks Jonathan L.
Published: March 2009

This paper summarises the main conclusions from the post-incident review instigated by the Environment Agency into the failure of the stepped masonry spillway at Ulley dam near Rotherham, UK, during a flood in June 2007.
Low level outlets 1: formula for target capacity
Authors: Hinks Jonathan
Published: March 2009

It has for some time been apparent that there is little consistency of approach in the United Kingdom to the question of low level outlet capacity or valve arrangements. The author suggests a new formula for low level outlet capacity for higher category earthfill dams in the United Kingdom which may also be of use for small reservoirs with earthfill dams overseas. The question of fitting upstream valves and/or lining of pipes is also discussed.
Stacking Seismograms to Improve Microseismic Images
Authors: Shemeta J. E. , Maxwell S. , Warpinski N. R. , Quimby S. , Riebel T. , Phillips Z. , Kinser J. R. , Hinds G. , Green T. W. , Waltman C. K.
Published: March 2009

Microseismic mapping's primary limitation is its viewing distance, which is affected by noise, attenuation, and the intrinsic size of the source event. In the Rocky Mountains, the required viewing distances are often less than typical offset-well spacings, making accurate mapping difficult in many fields. A new approach to improving microseismic mapping capabilities is to digitally stack the signals from separate adjacent receivers to obtain noise cancellation. This approach requires large numbers of receivers and fast telemetry rates to obtain the necessary data. An experiment has been conducted in the Uintah basin with a 12 level receiver array in which 3 of the 12 levels consisted of triple receiver stacks. The improvement in the signal quality consists of reduced noise, improved hodogram linearity, and clearer phase arrivals. The subsequent microseismic maps using stacked data are both more accurate and contain more events that can be analyzed.
Production Optimization by Real-Time Modeling and Alarming: The Sendji Field Case
Authors: Danquigny Jacques , Daïan Renaud , Tison Marc , Herrera Ronald , Ndombi Alain-Serge , Valette Pierre
Published: March 2009

Digital technologies can improve oil production and reduce operating costs. In this prospect, TOTAL launched a corporate program called "Field Monitoring" to capitalize affiliate previous experiences. For gas-lifted wells, it resulted in the development of the "Well Performance Monitoring" (WPM) tool implemented in December 2006 at the Sendji field located offshore Congo.

This paper presents the main workflows, functionalities, and added value of WPM.

Besides multi-real-time data trends, the application offers color-coded multialarm visualization versus time. These alarms are ranked in terms of "priority" and aggregated at each well, platform, field, and asset level, which allows well engineers to easily track down underperforming wells.

Alarms priority can be linked either to well integrity issues or production losses. These real-time estimated losses are computed using network and well-modeling softwares; they highlight deviation from optimum operating set points.

WPM makes easier regular optimization of gas-lift optimization by feeding models inputs with user-validated real-time data.

A major challenge of right-time production optimization is to sustain updated models. Two workflows address this issue: 1) automatic modeling of production well tests and 2) real-time modeling of the actual behavior of the production system. When a significant difference occurs between modeling and reality, a specific alarm is triggered.

This paper shows various examples of enhanced well performance diagnosis and the corresponding production gains. Also, good support from onsite teams was achieved thanks to key technical solutions, such as user-friendly interface, possible individual tuning of each alarm, and handling of unstable or unmatched wells. Finally, WPM enables computation of KPIs that allow the evaluation of potential well interventions.

This tool will be deployed at a corporate level and extended to ESP-lifted wells, gas injectors or producers, and to subsea wells in deep offshore environment. The general alarming, interface features, and data architecture will be applied to surface equipment monitoring and optimization.
A Systematic Investigation of Girassol Deepwater-Field Operational Data To Increase Confidence in Multiphase Simulation
Authors: Zakarian Erich , Larrey Dominique
Published: March 2009

After more than 5 years of experience as operator of Girassol, the earliest deepwater field put in production offshore West Africa, Total has recorded a large amount of operational data. The production system includes several conventional subsea loops connected to a floating-production, storage and offloading vessel (FPSO) at 1,350-m water depth, with gas lift injected at the bottom of the risers for activation and flow stabilization.

A systematic review of the operating parameters of the subsea production loops over the past years gave the opportunity to extract series of measurements representative of a wide range of flow rates, watercuts, and gas-lift rates, including flow-stability tests performed both on upward- and downward-sloping flow-lines. These data were compared to the results obtained from dynamic simulations performed with the simulation code OLGA, originally used for the design of the subsea production system. The comparison focused on the overall pressure drop between manifolds and topside and on the transition between stable and unstable flow with decreasing gas lift rate.

The work was conducted in two steps. First, updating the model of each flowline to implement the details of the as-built geometry, then performing extensive numerical simulations and post-processing of the selected operational cases. Particular attention was paid to the first step to achieve the best compromise between model accuracy and computation speed. The optimum was met when the model, run with the Slug Tracking option, was able to reproduce the transition to unstable flow observed onsite.

To investigate future operating conditions of the Girassol field, this methodology will help to establish a confidence level in multiphase simulation. This work can also serve as a reference for other deepwater-field developments.
Asphaltene Precipitation From Reservoir Fluids: Asphaltene Solubility and Particle Size vs. Pressure
Authors: Muhammad Moin , McFadden Jim , Creek Jeff
Published: March 2009

The near-infrared (NIR) light scattering technique, commercially known assolids detection system (SDS) is widely used to determine the asphalteneprecipitation pressure in reservoir fluids. In this study the SDS is used tocompare samples collected from the same zone in the same well at the same timebut in different sample chambers. The SDS technique is further compared withhigh pressure filtration for the same fluid studied by SDS In addition,asphaltene precipitation as a function of pressure was determined.

The results of this study indicate that the SDS test provides a quick toolto determine the asphatene precipitation pressure but has limited sensitivity.Furthermore, the bulk of asphaltenes tended to precipitate within a narrowpressure range near the precipitation onset pressure for the fluid sampletested in this study.
Seismic Geomorphology and Connectivity of Deepwater Reservoirs
Authors: Ragagnin Gilberto M. , Moraes Marco A. S.
Published: March 2009

Assessing reservoir connectivity and permeability heterogeneity is essential for predicting reservoir performance. Because reservoirs are 3D entities, there is little value in trying to predict reservoir connectivity on the basis of 2D data such as geological sections or maps. A new method for seismic volumetric visualization, complemented with outcrop analog data, was used for assessing reservoir connectivity and permeability heterogeneity of the deepwater reservoirs of Marlim Sul field, Campos basin, Brazil.

The seismic method consists of combining reflectivity and impedance seismic volumes. For the reservoir target zone, reflectivity was used as top drape covering the whole area, with color contrasts differentiating reservoirs from nonreservoirs. In the impedance volume, the anomalies represent the reservoirs. Such a volumetric visualization technique permits better identification of architectural elements and better understanding of the evolution of the depositional system. However, some limitations remain. Before building a reservoir model, it is necessary to assess the internal permeability heterogeneity of the different architectural elements and the petrophysical nature of the boundaries among the different elements. This was performed by comparing geometries and facies observed subsurface with geometries and facies documented in outcrop analogs. The main controls on connectivity and permeability heterogeneity in deepwater reservoirs are permeability barriers and baffles, such as hemipelagic shales and marls, turbiditic drapes, debris-flow deposits, shale-clast breccias, and cemented zones. Such features present a complex and varied distribution. Barrier and baffle 3D maps of the different architectural elements and of the limits among them obtained in representative outcrops were used to complement seismic information.

The integration of seismic volumetric visualization with outcrop analog data, calibrated by well information and tested against production data, proved to be useful for improving reservoir models.
Analytical Predictions and Lattice Boltzmann Simulations of Intrinsic Permeability for Mass Fractal Porous Media
Authors: Cihan Abdullah , Sukop Michael C. , Tyner John S. , Perfect Edmund , Huang Haibo
Published: March 2009

We derived two new expressions for the intrinsic permeability (k) of fractal porous media. The first approach, the probabilistic capillary connectivity (PCC) model, is based on evaluating the expected value of the cross‐sectional area of pores connected along various flow paths in the direction in which the permeability is sought. The other model is a modified version of Marshall's probabilistic approach (MPA) applied to random cross matching of pores present on two parallel slices through a fractal porous medium. The Menger sponge is a three‐dimensional mass fractal that represents the complicated pore space geometry of soil and rock. Predictions based on the analytical models were compared with estimates ofkderived from lattice Boltzmann method (LBM) simulations of saturated flow in virtual representations of Menger sponges. Overall, the analytically predictedkvalues matched thekvalues from the LBM simulations with <14% error for the deterministic sponges simulated. While the PCC model can represent variation in permeability due to the randomization process for each realization of the sponge, the MPA approach can capture only the average permeability resulting from all possible random realizations. Theoretical and empirical analyses of the surface fractal dimension (D2) for successive slices through a random Menger sponge show that the meanD2value 〈D2〉 =D3− 1, whereD3is the three‐dimensional mass fractal dimension. Incorporating 〈D2〉 into the MPA approach resulted in akthat compared favorably with the modal value ofkfrom LBM simulations performed on 100 random realizations of a random Menger sponge.
Advective–Dispersive Equation with Spatial Fractional Derivatives Evaluated with Tracer Transport Data
Authors: Martínez F. San José , Pachepsky Y. A. , Rawls W. J.
Published: March 2009

The classical model used to describe solute transport in soil is based on the advective–dispersive equation (ADE) in which an analog of Fick's law is used to model dispersion. The fractional ADE (FADE) has been proposed to address discrepancies between experimental solute concentrations and those predicted with the ADE. The order of the fractional derivative or Lévy exponent, α, characterizes the deviation of the FADE solutions from the ADE, which is a specific case of the FADE for α = 2. The objective of this work was to test the hypothesis that using the FADE with values of α other than 2 can provide more accurate simulations of solute transport in soils. We fitted the FADE to 47 published data sets on tracer breakthrough in disturbed and undisturbed soil columns. The FADE was solved numerically with a mass‐conserving boundary condition. While 19 breakthrough curves were best fitted with the ADE, the rest were fitted better using the FADE with α < 2. The RMSEs of the FADE and ADE were close when the FADE α was >1.5. In contrast, the FADE RMSEs were, on average, 1.5 times smaller than the ADE RMSE when the FADE was fitted with α < 1.5. The value of α apparently reflected the structure of the void space available for flow and transport. Considered as a generalization of the classical ADE, the FADE can be a useful model if tails of the breakthrough curve are of special interest.
Flow Dimension and Anomalous Diffusion of Aquifer Tests in Fracture Networks
Authors: Cello Pablo A. , Walker Douglas D. , Valocchi Albert J. , Loftis Bruce
Published: March 2009

Characterization and modeling of aquifers is particularly challenging in fractured media, where flow is concentrated into channels that are poorly suited to traditional approaches to analysis. The generalized radial flow model is an alternative method for hydraulic test interpretation that infers an additional parameter, the flow dimension n, to describe the flow geometry. This study was a Monte Carlo analysis of numerical models of aquifer tests in two‐dimensional fractured media, with the objective of understanding the relationships between the parameters of a discrete fracture network (DFN) with lengths distributed as a power law, the flow dimension, and the regime of hydraulic diffusion (e.g., Fickian or non‐Fickian). The diffusion regime of each realization was evaluated using 〈R2〉 ∼ tk, where t is time, 〈R2〉 is the mean squared radius of hydraulic diffusion, and an apparent value of k = 1 indicates normal (Fickian) diffusion and k < 1 indicates anomalous (non‐Fickian) diffusion. For the DFN model, the apparent flow dimension and exponent k depend on both the density and the power of the fracture length distribution, and thus also on the connectivity regime of the fracture network system. Depending on the connectivity regime, the apparent flow dimension stabilizes to less than the Euclidean dimension and the apparent value of k < 1 indicates that hydraulic diffusion is non‐Fickian. These results suggest that the flow dimension and the exponent k may be useful for characterizing flow and transport in fractured media.
Water Infiltration and Redistribution in Soil Aggregate Packings
Authors: Carminati A. , Flühler H.
Published: March 2009

Aggregation of soil particles is crucial for water flow in the vadose zone. Recent studies demonstrated that the unsaturated water flow through an aggregate pair is controlled by the contacts between aggregates. In these studies, the hydraulic conductivity of an aggregate pair was calculated as the harmonic mean of the conductivities of one aggregate and one contact, and it was fitted increasing the tortuosity from 0.5 to 5. In the present study, we investigated whether the contacts between aggregates control the water flow also in large aggregate packings. Our hypothesis was that unsaturated water flow in aggregate packings is primarily a flow in series through aggregates and contacts, and therefore the hydraulic conductivity of the system is properly approximated with that of an aggregate pair. To verify this hypothesis, we used neutron radiography to image water infiltration and redistribution in a cylindrical packing of aggregates. Then we numerically simulated the experiment using the hydraulic properties obtained from the model of an aggregate pair—i.e., tortuosity equal to 5. The observed water flow showed that the water redistribution following infiltration was particularly slow and the wetting front was very sharp. These features are explained by the bottleneck effect of the contacts, which were rapidly drained and limited the flow. This flow behavior was well reproduced in the simulations with tortuosity equal to 5, while simulations with tortuosity equal to 0.5, which is the tortuosity obtained for the aggregates, could not reproduce the observations. This study shows that the contacts control the unsaturated water flow also in larger aggregate packings and the process can be in a first approximation modeled as a flow in series through aggregates and contacts.
Effect of Sulfide Inhibition and Organic Shock Loading on Anaerobic Biofilm Reactors Treating a Low‐Temperature, High‐Sulfate Wastewater
Authors: McDonald Heather B. , Parkin Gene F.
Published: March 2009

To assess the long‐term treatment of sulfate‐ and carbon‐rich wastewater at low temperatures, anaerobic biofilm reactors were operated for over 900 days at 20°C and fed wastewater containing lactate and sulfate. Results showed the reactors could be operated at 20°C with a load rate of 1.3 g‐chemical oxygen demand (COD)/L · d or less and a sulfur loading rate (SLR) of 0.2 g‐S/L · d, with no significant deterioration in performance. With acclimation periods, load rates of 3.4 g‐COD/L · d and SLR of 0.3 g/L · d could be tolerated. Effluent dissolved sulfide and hydrogen sulfide levels were approximately 600 and 150 mg‐S/L, respectively, during this period. The effect of organic shock loading was also assessed. Reactors appeared to recover from one, but not two, lactate spikes of approximately 5000 mg‐COD/L. Long‐term stability was achieved in reactors containing large, stable populations of lactate‐ and propionate‐degrading sulfate‐reducing bacteria and aceticlastic methanogens.
A Preliminary Investigation on the Occurrence and Distribution of Antibiotics in the Yellow River and its Tributaries, China
Authors: Xu Weihai , Zhang Gan , Zou Shichun , Ling Zhenhao , Wang Guoliang , Yan Wen
Published: March 2009

This study investigated the residues of antibiotics present in the Yellow River and its tributaries. Ofloxacin, norfloxacin, roxithromycin, erythromycin, and sulfamethoxazole, were found in the river with mean concentrations from 25 to 152 ng/L, and in certain tributaries from 44 to 240 ng/L. The other four analytes were all below the limits of quantification. The results indicated that the detected antibiotics in the middle and lower Yellow River were primarily from its tributaries and ambient wastewater discharge. The concentrations of the antibiotics detected in the river were greater than that in other rivers in Europe. The antibiotics in the river and its tributaries at ng/L concentrations found in this study are unlikely to induce lethal toxicity to aquatic organism but could cause chronic ecological effects.
Research Note: Modeling of the Water Quality of Büyüksu Stream, Bolu, Turkey
Authors: Yıldırım Muhammet , Şen Ersin , Külköylüog˘lu Okan
Published: March 2009

The QUAL2E model was applied to the Büyüksu Stream, Bolu, Turkey, to predict the effect of conventional and industrial pollutant sources on stream quality. The model parameters were conditioned using data from eight sampling stations on a 24‐km stretch of the stream during a steady‐state period between May 2003 and June 2004. The higher biochemical oxygen demand (>50 mg/L) and lower dissolved oxygen concentrations measured (<4.0 mg/L), with their expected values, indicated that the water quality of the Büyüksu Stream was threatened by industrial and domestic pollution. The oxygen‐sag curves obtained by the model calculations proved that discharges of the Bolu City wastewater and wood‐processing plant effluent were the two primary pollutant sources affecting the stream. Results suggested that the conditioned model can be used as a tool to show the effects of pollutant sources on the Büyüksu Stream and to assess improvements expected by reducing the contribution of pollutant sources.
Characteristics of Highway Stormwater Runoff in Los Angeles: Metals and Polycyclic Aromatic Hydrocarbons
Authors: Lau Sim‐Lin , Han Younghan , Kang Joo‐Hyon , Kayhanian Masoud , Stenstrom Michael K.
Published: March 2009

Stormwater runoff from three highway sites in Los Angeles, California, was monitored, during the 2000 to 2003 wet seasons. Correlations among heavy metals, polycyclic aromatic hydrocarbons (PAHs), and storm characteristics were performed using datasets collected for 62 storm events. Statistical correlation analyses of the event mean concentrations (EMCs) and mass first‐flush ratios (MFFs) with storm characteristics were conducted to determine if the first flush is related to site or storm characteristics. This study agreed with other highway runoff characterization studies, in that strong correlations were observed among the heavy metals and between heavy metals and total PAHs, and total suspended solids were well correlated with most heavy metals. Only antecedent dry days among storm characteristics were reasonably well‐correlated with the EMCs of heavy metals and total PAHs, and dissolved and total metals exhibited similar MFFs, with approximately 30 to 35% of the mass being discharged in the first 20% of the runoff volume.
Using the Error in Pre-Election Polls to Test for the Presence of Pork
Authors: McIntosh Craig , Allen Jacob
Published: March 2009

Polls are used by politicians, voters, and businesspeople alike to form expectations over political outcomes. In an electoral system with pork' at the national level, local economic prospects will be a direct function of political support. Because every poll comes with its margin of error, we can exploit the error in sub-national polls to test for whether forward-looking investment in the economy adjusts to shocks in local political behavior. The covariance between the strength of this adjustment and local-level characteristics allows us to identify the locations in which strong pork' contracts exist. To illustrate the technique, we provide a theoretical foundation and an empirical exercise using data on Ugandan micro-entrepreneurs during the 2001 presidential election. We find evidence that investor behavior responds in a small but significant way to surprises in electoral support, and this responsiveness is strongest in core' electoral districts.
Accuracy, Sensitivity, and Correlation of FEA-Computed Coastdown Rolling Resistance
Authors: Terziyski J. , Kennedy R.
Published: March 2009

This research deals with finite element analysis (FEA) predictions of coastdown rolling resistance as outlined by the SAE J2452 test procedure. The proposed method employs a phenomenological formulation of hysteresis which considers the effects of strain, strain rate, and temperature. Through specifically designed test conditions, material parameters are established for typical tire rubber components. The strain and strain rate histories at the cross section integration points are obtained from a static FEA of a loaded tire for one tire revolution and the desired speed. In subsequent postprocessing, the locations of the octahedral shear strain reversal in tire volume are found, and then rolling resistance is calculated by assuming an isothermal analysis. The simulation sensitivity to modeling considerations, including geometry accuracy and FE mesh resolution, on predicted rolling losses is pointed out. The applicability of the present approach to daily product engineering is discussed through benchmark studies of a variety of tires of different sizes, constructions, tread materials, and test conditions. Correlation studies demonstrate that this is a robust and easily implemented technique for rolling resistance analysis. A steady-state temperature solution, obtained from the hysteretic loss results, is used to predict the temperature field in the tire and to investigate its influence on the rolling resistance calculation.
Introduction
Authors: Owczarzak Jill
Published: March 2009

The introduction to this special section explores the ways in which postcolonial studies contribute a deeper understanding of postsocialist change in Central and Eastern Europe. Since the collapse of socialism, anthropological and other social science studies of Eastern Europe have highlighted deep divides between “East” and “West” and drawn attention to the ways in which socialist practices persist into the postsocialist period. We seek to move beyond discourses of the East/West divide by examining the postsocialist context through the lens of postcolonial studies. We look at four aspects of postcolonial studies and explore their relevance for understanding postsocialist Eastern Europe: orientalism, nation and identity, hybridity, and voice. These themes are particular salient from the perspective of gender and sexuality, key concepts through which both postcolonialism and postsocialism can be understood. We thus pay particular attention to the exchange of ideas between East/West, local/global, and national/international arenas.
Re-imagining Amazonia
Authors: Viatori Maximilian
Published: March 2009

Michael Heckenberger, The ecology of power: Culture, place and personhood in the Southern Amazon, AD 1000-2000. London and New York: Routledge, 2004, 432 pp., ISBN: 0-415-94599-2 (paperback).

John Hemming, Tree of rivers: The story of the Amazon. London and New York: Thames and Hud- son, 2008, 366 pp., ISBN: 978-0-500-51401-6 (hardback).

Candice Slater, Entangled Edens: Visions of the Amazon, Berkeley: University of California Press, 2002, 332 pp., ISBN: 0-520-22641-0 (paperback).
Pastoral Nomad Rights in Inner Mongolia
Authors: Zhizhong Wu , Wen Du
Published: March 2009

It is not scientific to manage grasslands as farmland and manage nomads as farmers. We report evidence from Inner Mongolia that privatization of grassland use rights has led to large-scale wire fencing, grassland conversion to farming, excessive livestock stocking, and crises in grassland ecology, herders' living conditions and the Mongolian nomadic culture. The paper concludes that the ecological and cultural function of nomadism is non-substitutable from the perspectives of ecological security and cultural inheritance. The authors suggest that we should abolish private grassland use rights, tear down wire fencing, abolish set stocking rates and establish a legal nomad administrative licensing system to resume nomadism.
Effects of Different Grazing on the Typical Steppe Vegetation Characteristics on the Mongolian Plateau
Authors: Xiuxia Bao , Jin Yi , Shurun Liu , Jimuse Gaowa , Wureqimuge  , Jigejidesuren  , Budebateer  , Puchang Wang , Yong Lian
Published: March 2009

We studied plant community characteristics of typical steppe vegetation under different grazing systems on the Mongolian plateau of Inner Mongolia in China and the Republic of Mongolia. The different grazing types were defined as four season nomadic, four season rotational, two season rotational and settled grazing. Total cover (per cent), total weight (g/m2) and total plant richness were greater for the four season nomadic and four season rotational compared to the two season rotational and settled grazing. In general vegetation indicators exhibiting less grazing impact by grazing systems followed the following sequence: four season nomadic > four season rotational > two season rotational > settled grazing. There was little difference in estimated grazing capacity of the study areas but large differences in grassland degradation. Therefore, our findings suggest that under the same carrying capacity, four season nomadic and four season rotational grazing have less detrimental impacts on a typical Mongolian steppe vegetation characteristics compared to the settled grazing. We believe that vegetation restoration is also more rapid in the four season rotational systems because there is less trampling by livestock and in settled grazing there is little to no resumption of plant growth.
Between Cash Cows and Golden Calves: Adaptations of Mongolian Pastoralism in the 'Age of the Market'
Authors: Marin Andrei
Published: March 2009

Pastoralism in Mongolia has increasingly been portrayed by two powerful and mutually reinforcing discourses. First, the neo-liberal discourse enthusiastically embraced and reproduced by most of the Mongolian political elite constructs pastoralism as backward and unproductive, in need of modernization, and sedentarization. Second, an increasingly powerful essentialist discourse argues for the preservation of 'traditional' Mongolian pastoralism. By presenting a stereotypical image of 'the nomadic culture' on the brink of extinction, outsiders (e.g. NGOs, the tourist industry) become stakeholders in the debate on Mongolian identity and the country's development path. They also help (unwillingly perhaps) reinforce the image of the pastoralist as obsolete and 'timeless'. The article shows that the realities of Mongolian pastoralists lie beyond these two constructs. The pastoralists have taken steps toward adapting to the new socio-economic realities: they use veterinary services, try to use the market system and social services. Yet their adaptive capacity is severely limited by unfavourable social and economic circumstance endorsed by the State.
Anatomical features of the cisternal segment of the oculomotor nerve: neurovascular relationships and abnormal compression on magnetic resonance imaging
Authors: Liang Changhu , Du Yinglin , Lin Xiangtao , Wu Lebin , Wu Dawei , Wang Ximing
Published: March 2009

Object

The object of this study was to assess the detailed anatomical features and vascular relationships of the cisternal segment of the oculomotor nerve, and to assess the utility of MR imaging in oculomotor nerve palsy caused by abnormal compression related to arteries and tumors.

Methods

The anatomy of the oculomotor nerve was depicted using 3D Fourier transformation constructive interference in steady-state (CISS) MR imaging in 196 volunteers (392 total nerves), in 9 patients with paralysis of the oculomotor nerve, and in 1 preoperative patient with cholesteatoma in the pontine cistern. The vessels adjacent to the oculomotor nerve were detected and compared using 3D time-of-flight MR imaging. The 3D CISS multiplanar reconstruction (MPR) images of the oculomotor nerve in cadavers and in specimens from the cadavers were used to verify the oculomotor nerve shown in the 196 patients. The images were assessed with respect to the demonstration of the oculomotor nerve, the optimal display angles on MPR images, the visualized length of the nerve, neurovascular relationships, and abnormal compression caused by arteries and tumors.

Results

Three-dimensional CISS MR imaging depicted the cisternal segment of the oculomotor nerve with certainty in 100% of the patients in the transverse, sagittal, and coronal planes. Three-dimensional CISS imaging of the oculomotor nerve in 196 volunteers revealed similar results corresponding to 3D CISS MPR images of cadavers and cadaver specimens. The maximum visualized length of the oculomotor nerve was 14.61 ± 2.33 mm. The angle between the oculomotor nerve and the median sagittal plane was 24.48 ± 4.57° on the left and 24.48 ± 5.07° on the right. The posterior cerebral artery was observed to contact the oculomotor nerve in 216 (55.1%) of 392 nerves, and the superior cerebellar artery was observed to contact the oculomotor nerve in 231 (58.9%) of 392 nerves. The abnormal nerve compression in 9 patients with paralysis of the oculomotor nerve was displayed well in all patients. The adjacent relationship of the oculomotor nerve in 1 preoperative patient with cholesteatoma in the pontine cistern was also demonstrated clearly.

Conclusions

Use of 3D CISS sequences and 3D time-of-flight sequences enables accurate identification of the cisternal segment of the oculomotor nerve, neurovascular relationships, and abnormal compression caused by arteries and tumors.