bluuebunny/crossref_metadata_2025 huggingface dataset:
Improved Inventory Targets in the Presence of Limited Historical Demand Data
Authors: Akcay Alp , Biller Bahar , Tayur Sridhar
Published: February 2011

Most of the literature on inventory management assumes that the demand distribution and the values of its parameters are known with certainty. In this paper, we consider a repeated newsvendor setting where this is not the case and study the problem of setting inventory targets when there is a limited amount of historical demand data. Consequently, we achieve the following objectives: (1) to quantify the inaccuracy in the inventory-target estimation as a function of the length of the historical demand data, the critical fractile, and the shape parameters of the demand distribution; and (2) to determine the inventory target that minimizes the expected cost and accounts for the uncertainty around the demand parameters estimated from limited historical data. We achieve these objectives by using the concept of expected total operating cost and representing the demand distribution with the highly flexible Johnson translation system. Our procedures require no restrictive assumptions about the first four moments of the demand random variables, and they can be easily implemented in practical settings with reduced expected total operating costs.
Fluid Tasks and Fluid Teams: The Impact of Diversity in Experience and Team Familiarity on Team Performance
Authors: Huckman Robert S. , Staats Bradley R.
Published: February 2011

In this paper, we consider how the structures of tasks and teams interact to affect team performance. We study the effects of diversity in experience on a team's ability to respond to task changes by separately examining interpersonal team diversity (i.e., differences in experience across the entire team) and intrapersonal team diversity (i.e., whether individuals on the team are more or less specialized). We also examine whether team familiarity—team members' prior experience working with one another—helps teams to better manage challenges created by task changes and greater interpersonal team diversity. Using detailed project- and individual-level data from an Indian software services firm, we find that the interaction of task change with intrapersonal diversity is related to improved project performance, whereas the interaction of task change with interpersonal diversity is related to diminished performance. Additionally, the interaction of team familiarity with interpersonal diversity is related to improved project performance in some cases. Our results highlight a need for more nuanced approaches to leveraging experience in team management.
Formulations and Branch-and-Cut Algorithms for the Generalized Vehicle Routing Problem
Authors: Bektaş Tolga , Erdoğan Güneş , Røpke Stefan
Published: February 2011

The generalized vehicle routing problem (GVRP) consists of finding a set of routes for a number of capacitated vehicles on a graph where the vertices are partitioned into clusters with given demands, such that the total cost of travel is minimized and all demands are met. This paper describes and compares four new integer linear programming formulations for the GVRP, two based on multicommodity flow and the other two based on exponential-size sets of inequalities. Branch-and-cut algorithms are proposed for the latter two. Computational results on a large set of instances are presented.
Constructive Heuristics for the Multicompartment Vehicle Routing Problem with Stochastic Demands
Authors: Mendoza Jorge E. , Castanier Bruno , Guéret Christelle , Medaglia Andrés L. , Velasco Nubia
Published: February 2011

The vehicle routing problem with stochastic demands (VRPSD) consists of designing transportation routes of minimal expected cost to satisfy a set of customers with random demands of known probability distribution. This paper tackles a generalization of the VRPSD known as the multicompartment VRPSD (MC-VRPSD), a problem in which each customer demands several products that, because of incompatibility constraints, must be loaded in independent vehicle compartments. To solve the problem, we propose three simple and effective constructive heuristics based on a stochastic programming with recourse formulation. One of the heuristics is an extension to the multicompartment scenario of a savings-based algorithm for the VRPSD; the other two are different versions of a novel look-ahead heuristic that follows a route-first, cluster-second approach. In addition, to enhance the performance of the heuristics these are coupled with a post-optimization procedure based on the classical 2-Opt heuristic. The three algorithms were tested on instances of up to 200 customers from the MC-VRPSD and VRPSD literature. The proposed heuristics unveiled 26 and 12 new best known solutions for a set of 180 MC-VRPSD problems and a 40-instance testbed for the VRPSD, respectively.
Integrating Slot Exchange, Safety, Capacity, and Equity Mechanisms Within an Airspace Flow Program
Authors: Sherali Hanif D. , Hill Justin M. , McCrea Michael V. , Trani Antonio A.
Published: February 2011

In this paper, we study an airspace flow program in the context of weather-related disruptions by augmenting the airspace planning and collaborative decision-making model (APCDM). The proposed model selects among alternative flight plans for the affected flights while integrating slot exchange mechanisms induced by multiple ground delay programs (GDPs) to permit airlines to improve flight efficiencies through a mediated bartering of assigned slots, and simultaneously considering issues related to sector workloads and airspace conflicts, as well as overall equity concerns among the involved airlines in regard to accepted slot trades and flight plans. The APCDM is enhanced to include (a) the selection of slot exchange trade offers suggested by the airlines based on their allotted slots under a GDP; (b) connections between continuing flights; and (c) several alternative equity concepts. Both full and light versions of this model are developed and tested using realistic data derived from the enhanced traffic management system data provided by the Federal Aviation Administration.
Quantitative Mid-Infrared Diffuse Reflection of Occupational Wood Dust Exposures
Authors: Chirila Madalina M. , Lee Taekhee , Flemmer Michael M. , Slaven James E. , Harper Martin
Published: February 2011

Occupational exposure to airborne wood dust has been implicated in the development of several symptoms and diseases, including nasal carcinoma. However, the assessment of occupational wood dust exposure is usually performed by gravimetric analysis, which is non-specific. In this study, a mid-infrared (mid-IR) diffuse reflection method was adapted for direct on-filter determination of wood dust mass. The cup from the diffuse reflection unit was replaced with a horizontal translational stage and a filter with wood dust was set thereon. Diffuse reflection (DR) spectra were collected from filters with six different diameters in order to average the signal from the most filter surface. Two absorption bands around 1595 and 1510 cm−1, attributed to lignin, were monitored for quantitative analysis. Calibration curves were constructed for standard extrathoracic red oak and yellow pine (aerodynamic particle diameters between 10 and 100 (μm). Calibration of DR intensity versus known wood dust mass on the filter using the Kubelka-Munk function showed a nonlinear dependence for mass of less than 10 mg of wood dust. The experimental data and small-thickness samples indicate that Kubelka-Munk conditions are not obeyed. Alternatively, the pseudo-absorption function log(1/ R), for which R is the relative reflectance, while still giving nonlinear dependence against mass, is closer to a linear dependence and has been preferred by other researchers. Therefore, we consider the use of the log(1/ R) function for mid-infrared DR analysis of neat, small-thickness wood dust samples. Furthermore, we suggest the use of a silver metal membrane filter for direct on-filter analysis of wood dust rather than the glass fiber filters that have been used previously.
Surface Reaction of LiCoO2/Li System under High-Voltage Conditions by X-Ray Spectroscopy and Two-Dimensional Correlation Spectroscopy (2D-COS)
Authors: Park Yeonju , Kim Nam Hoon , Kim Jong Myong , Kim Young Chul , Jeong Yeon Uk , Lee Sung Man , Choi Hyun Chul , Jung Young Mee
Published: February 2011

We studied the surface reactions of a LiCoO2/Li cell under high-voltage conditions using X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and two-dimensional correlation spectroscopy (2D-COS). 2D XPS correlation spectra show that Li2CO3 is formed first by decomposition of the organic solvents, and then polycarbonate, which is formed by polymerization of the electrolytes, is produced on the cathode surface of the LiCoO2/Li system under high-voltage conditions. XAS measurements also confirm that the solid electrolyte interface (SEI) layer is formed on the LiCoO2 electrode by decomposition of the organic solvents. The thickness of the SEI layer is less than 100 Å.
Newborn Screening for Isovaleric Acidemia Using Tandem Mass Spectrometry: Data from 1.6 Million Newborns
Authors: Ensenauer Regina , Fingerhut Ralph , Maier Esther M , Polanetz Roman , Olgemöller Bernhard , Röschinger Wulf , Muntau Ania C
Published: February 2011

BACKGROUND

Electrospray ionization–tandem mass spectrometry (ESI-MS/MS) has been used in the Bavarian newborn screening (NBS) program since 1999. The use of ESI-MS/MS has led to the inclusion of isovaleric acidemia (IVA) into NBS. We retrospectively evaluated data on more than 1.6 million newborns screened during 9.5 years.

METHODS

Acylcarnitines from whole blood spotted on filter paper were converted to their corresponding butyl esters, and the samples were analyzed by use of ESI-MS/MS with stable isotope labeled internal standards.

RESULTS

A total of 24 individuals with IVA were detected by use of a multiparametric threshold criteria panel including isovalerylcarnitine (C5) and the ratios of C5 to octanoyl-, butyryl-, and propionylcarnitine. A cutoff set at the 99.99th percentile for isolated C5 or at the 99th percentile for C5 plus at least 2 ratios resulted in a positive predictive value for IVA screening of 7.0% and an overall recall rate of 0.024%. Adjusted reference ranges for age and birth weight were applied, and the incidence of IVA in the study population was calculated to be 1 in 67 000. Missed cases were not brought to our attention. IVA was also detectable in cord blood and early postnatal blood samples.

CONCLUSIONS

IVA can be reliably detected in NBS through acylcarnitine analysis in dried blood spots by using multiparametric threshold criteria. Further improvement (positive predictive value 13.0%, recall rate 0.01%) can be achieved by using more stringent recall criteria. In view of the potentially life-threatening natural course of IVA in early life, presymptomatic diagnosis may thus prevent mortality and morbidity.
Messunsicherheitsbestimmung für die industrielle Computertomografie anhand kalibrierter Bauteile
Authors: Schmitt Robert , Damm Björn , Niggemann Christian
Published: February 2011

Bei der Messung dimensioneller Größen mit Röntgen-Computertomografie (CT) kann die Messunsicherheit anhand kalibrierter Werkstücke ermittelt werden. Die Methode eignet sich sowohl zur Abschätzung von Einflussgrößen auf das Messergebnis als analytisches Instrument als auch zum Nachweis der Eignung eines Prüfprozesses. Beide Möglichkeiten werden vor dem Hintergrund der komplexen Messung mit CT aufgezeigt und die Anwendbarkeit diskutiert.
Gewachsene Siliziumstrukturen zum Kalibrieren von Messgeräten im nm-Bereich
Authors: Dietzsch Michael , Gröger Sophie
Published: February 2011

Der Beitrag stellt die Ergebnisse eines Ringvergleiches zur Messung plateauartiger Nano-Strukturen auf einer gewachsenen Siliziumoberfläche mit verschiedenen taktilen und optischen Messgeräten vor. Die Strukturen sind Inseln mit einem Durchmesser von ca. 800 nm und einer Höhe von ca. 12 nm. Neben der vertikalen und horizontalen Ausdehnung können damit Auflösung, Sensoreigenschaften, Stufenhöhen und auf Grund des ideal ebenen Grundmaterials auch die Geradheiten von Führungsbahnen im Nanometerbereich kalibriert werden.
Neuere Entwicklungen von Normalen für die 3D-Mikro- und Nanometrologie
Authors: Neuschaefer-Rube Ulrich , Neugebauer Michael , Dziomba Thorsten , Danzebrink Hans-Ulrich , Koenders Ludger , Bosse Harald
Published: February 2011

Der Beitrag gibt einen Überblick über neuere Entwicklungen von Normalen und Messverfahren für die 3D-Mikro- und Nanometrologie mit Fokus auf Arbeiten der PTB. Ziel der Entwicklungen ist die Verringerung der Messunsicherheiten von Messgeräten zur dimensionellen Charakterisierung von Mikro- und Nanostrukturen.
Early post-transplantation hypophosphatemia is associated with elevated FGF-23 levels
Authors: Trombetti Andrea , Richert Laura , Hadaya Karine , Graf Jean-Daniel , Herrmann François R , Ferrari Serge L , Martin Pierre-Yves , Rizzoli René
Published: February 2011

Background

We examined the hypothesis that high FGF-23 levels early after transplantation contribute to the onset of hypophosphatemia, independently of parathyroid hormone (PTH) and other factors regulating phosphate metabolism.

Methods

We measured serum phosphate levels (sPi), renal tubular reabsorption of Pi (TmPi/GFR), estimated GFR (eGFR), intact PTH (iPTH), calcitriol, intact (int) and C-terminal (Cter) FGF-23, dietary Pi intake and cumulative doses of glucocorticoids in 69 patients 12 days (95% confidence interval, 10–13) after renal transplantation.

Results

Hypophosphatemia was observed in 43 (62%) of the patients 12 days after transplantation. Compared with non-hypophosphatemic subjects, their post-transplantation levels of intact and CterFGF-23 were higher (195 (108–288) vs 48 (40–64) ng/l,P<0.002 for intFGF-23; 205 (116–384) vs 81 (55–124) U/ml,P<0.002, for CterFGF-23). In all subjects, Cter and intFGF-23 correlated inversely with sPi (r=−0.35,P<0.003; −0.35,P<0.003, respectively), and TmPi/GFR (r=−0.50,P<0.001; −0.54,P<0.001, respectively). In multivariate models, sPi and TmPi/GFR were independently associated with FGF-23, iPTH and eGFR. Pre-transplant iPTH levels were significantly higher in patients developing hypophosphatemia after renal transplantation. Pre-transplant levels of FGF-23 were not associated with sPi at the time of transplantation.

Conclusion

In addition to PTH, elevated FGF-23 may contribute to hypophosphatemia during the early post-renal transplant period.
Coronally Advanced Flap Combined With a Subepithelial Connective Tissue Graft Using Full‐ or Partial‐Thickness Flap Reflection
Authors: Mazzocco Fabio , Comuzzi Luca , Stefani Riccardo , Milan Ylenia , Favero Giovanni , Stellini Edoardo
Published: February 2011

Background: Although the use of a subepithelial connective tissue graft (SCTG) in conjunction with a coronally advanced flap (CAF) is a widely performed periodontal procedure, the creation of a partial‐thickness flap can incur a risk of perforation or overthinning of the flap itself. Therefore, the aim of the present trial is to compare the efficacies of partial‐ and full‐thickness flap reflections combined with an SCTG.

Methods: Twenty patients with Miller Class I or II defects (52 teeth) were selected, and teeth with defects were randomly assigned to the test group (25 teeth) for a CAF and SCTG using a full‐thickness flap reflection or to the control group (27 teeth) for a CAF associated with an SCTG and partial‐thickness flap reflection. The probing depth (PD), gingival recession (GR), and width of the keratinized tissue (KT) were assessed at baseline and 6 months after surgery.

Results: The mean root coverage was 97% in the test group (mean reduction in GR: 2.27 ± 1.15 mm) and 95% in the control group (mean reduction in GR: 1.68 ± 0.74 mm). The gain in KT was 0.46 ± 1.47 mm in the test group and 0.49 ± 1.3 mm in the control group, the PD ranged from 1.33 to 1.55 mm in the test group and from 1.31 to 1.64 mm in the control group; no statistically significant difference was found between the two groups for all of these parameters (P >0.05).

Conclusions: The elevation of a full‐ or partial‐thickness flap did not appear to influence the amount of KT or the percentage of root coverage achieved post‐surgically. More expanded studies are needed to confirm the present findings.
Advantages and Challenges of Worldwide Standardization of Rig and Equipment Audits
Authors: Wirth S. A. , Spoerker H. F. , Ali M. K.
Published: February 2011

Any organization operating in diverse geographic areas experiences the challenge of standardizing equipment and service requirements to a common quality level. Controlling the level of risk that a company is willing to accept on its operations is one of the key reasons for having Management Systems, which are only as good as the auditing initiatives behind them to ensure compliance across the board. Such risk control can only be achieved if a consistent quality of all rigs and equipment working for the Company's worldwide subsidiaries in ensured.

Standardizing such auditing initiatives makes the outcomes comparable and usable as key performance indicators for benchmarking subsidiary compliance levels with corporate Standards. Having operations in countries as diverse as Austria, Yemen, Libya, UK/Norway, Pakistan, Kazakhstan etc. provides unique challenges in implementing one consistent set of Standards and executing audits to the same scope in all environments. What is considered as minimum requirement in one operating environment can sometimes be seen as excessive in another – and lead to conflicts with other operators who see such initiatives as unwarranted cost increases in generally less regulated areas.

This paper is intended to show the efforts taken by OMV in establishing a standardized audit procedure/schedule and producing an adequate framework of standards. As audits are not purely focused on equipment but strongly include personnel competence and management systems, the paper also presents typical challenges and findings from the first two years of auditing initiatives.
Remediation: An Evolution to Sustainable Environmental Practices
Authors: Martinson Michael , van den Brand Marco
Published: February 2011

Applying environmental sustainability concepts to contaminant remediation continues to evolve in the remediation cleanup marketplace. Increasingly, we recognize that mass transfer remediation practices only defer contamination problems to the future. The importance of environmental footprints in remediation work related to global issues has led to the consideration and development of sustainable practices in the selection and design of remediation systems. The recent development of Remediation Carbon Footprint Models (RCFMs) globally illustrate a variety of approaches to estimating the carbon footprints of remediation activities, ranging from simple, user-friendly input to comprehensive inputs resulting in cradle-to-grave considerations of carbon footprint impacts. Preferred practices in environmental sustainability increasingly contribute to long-term protection of human health and the environment, conservation of natural resources, and biodiversity – all balanced against economic viability. Sustainable remediation seeks to connect and balance shared values between economics, environmental, and social contributions.
Strong Reporting Culture as Stepping Stone To Continuously Drive Safety Performance Improvement
Authors: Stough J..
Published: February 2011

This paper will review the leading indicator research findings drawn from analyzing a large Energy industry data set. The source of research includes data sets and Safety business practices spanning operating sites in over 100 countries involving some global industry leading companies such as ExxonMobil, ConocoPhillips, Shell, Total, OMV, and multiple others.

From the analytical research and careful review with industry Safety executives and Subject Matter Experts, it was clear that attaining a strong Reporting Culture is a critical milestone necessary to begin the process of proactively driving Safety performance. The factors that best predicted the Safety outcome performance of an organization included measurements of (a) proactive event reporting (Reporting Culture), (b) the discipline and consistency in execution of HSE processes, (c) the timeliness in closure of important corrective / preventive actions, and finally (d) the responsiveness and accountability of supervisors and line managers.

In each of these key areas, solid performance can be attributed to the tone set by leadership and the influential day-to-day behavior of field supervision and line management. So, we will explore how these leaders can be engaged to improve the above factors.

This paper will also review the measurable leading factors that have been found to be uniquely strong in organizations that have sustained top-level Safety lagging performance. We will review some examples of creative technology solutions to reach out to front-line workers and leaders to engage them directly in the reporting process.

Lastly we will discuss the affects of risk-aware, accountable leadership in each of the key leading areas. And finally, we will demonstrate a process for implementing practical, "actionable" leading metrics in each key area to drive line manager / leadership behavior and ultimately improve HSE performance outcomes.
Compositional Flow Simulation Using Reduced-Variables and Stability-Analysis Bypassing
Authors: Pan Huanquan , Tchelepi Hamdi A.
Published: February 2011

The Phase Equilibrium Computations (PEC) associated with compositional flow simulation include: (1) Phase-Stability Analysis (PSA) of single-phase cells, and (2) Two-Phase Flash (TPF) for cells that change from one to two phases over a Newton iteration. For simulation of multi-contact miscible displacements, the PEC cost increases dramatically with the number of components, and for highly detailed models, PEC can become the most time consuming part of a simulation. In this work, we integrated the Reduced-Variables (RV) method (Pan and Firoozabadi 2002, 2003) for PEC with a compositional simulator that uses the natural-variables formulation (Coats, 1980). We also implemented an RV-based form of Rasmussen et al.'s (2006) method for bypassing PSA computations during a simulation run. We present and analyze simulation results for a wide range of problems. Specifically, we used three reservoir models: the top layer of the SPE10 reservoir model, a discrete fracture model, and a 3D model with 400,000 cells. Three different fluids were investigated, namely, the SPE3 fluid (9 components in the critical region), a 15-component gas-condensate system at high pressure, and a 26-component oil. We focused on multi-contact miscible displacement involving complex phase behavior, both in space and time. Compositional flow simulation with the RV-based method for bypassing PSA computations proved to be robust and efficient. Compared with the standard approach, over 80% of the PSA computations are bypassed, and where PSA is needed, the RV-based Newton method converges quadratically. In a typical simulation, the PEC computations take up only about 10% of the total CPU time. The exceptional performance of the RV-based method with PSA bypassing allows for modeling complex EOR processes of practical interest, where large numbers of components and highly detailed reservoir descriptions are needed. Implementation of the RV-based approach with PSA bypassing in existing reservoir simulators, especially those based on the natural-variables set, is straight forward.
Effects of Pasture Renovation on Hydrology, Nutrient Runoff, and Forage Yield
Authors: de Koff J. P. , Moore P. A. , Formica S. J. , Van Eps M. , DeLaune P. B.
Published: February 2011

Proper pasture management is important in promoting optimal forage growth and reducing runoff and nutrient loss. Pasture renovation is a management tool that improves aeration by mechanically creating holes or pockets within the soil. Pasture renovation was performed before manure application (poultry litter or swine slurry) on different pasture soils and rainfall simulations were conducted to identify the effects of pasture renovation on nutrient runoff and forage growth. Renovation of small plots resulted in significant and beneficial hydrological changes. During the first rainfall simulation, runoff volumes were 45 to 74% lower for seven out of eight renovated treatments, and infiltration rates increased by 3 to 87% for all renovated treatments as compared with nonrenovated treatments. Renovation of pasture soils fertilized with poultry litter led to significant reductions in dissolved reactive P (DRP) (74–87%), total P (TP) (76–85%), and total nitrogen (TN) (72–80%) loads in two of the three soils studied during the first rainfall simulation. Renovation did not result in any significant differences in forage yields. Overall, beneficial impacts of renovation lasted up to 3 mo, the most critical period for nutrient runoff following manure application. Therefore, renovation could be an important best management practice in these areas.
PAHs Pass Through the Cell Wall and Partition into Organelles of Arbuscular Mycorrhizal Roots of Ryegrass
Authors: Gao Yanzheng , Cao Xuezhang , Kang Fuxing , Cheng Zhaoxia
Published: February 2011

The subcellular process and distribution of polycyclic aromatic hydrocarbons (PAHs) in arbuscular mycorrhizal plants remains to be elucidated. This work used a greenhouse experiment to show that, accompanied by the apoplastic and symplastic water movement through the root, acenaphthene (ACE) as a representative PAH passed through the cell‐wall boundary, dissolved in the cell solution, and partitioned into organelles in arbuscular mycorrhizal roots of ryegrass (Lolium multiflorum Lam.). The observed concentrations of ACE in organelles were 0.6 to 4.4 times higher than in the cell walls. The cell wall and organelles were the dominant storage domains for ACE in the root, and the distribution of ACE in cells of mycorrhizal ryegrass roots was, in descending order, cell organelles (40.8–70.8%) > cell wall (19.7–39.8%) > cell solution (9.6–20.5%).
Runoff Transport of Pyrethroids from a Residential Lawn in Central California
Authors: Hanzas John P. , Jones Russell L. , White Jeffrey W.
Published: February 2011

An irrigation runoff study on a residential lawn was conducted in California, northeast of Sacramento, during the summer and fall of 2008 to investigate the contribution of turf uses of pyrethroids to residues in Californian urban creek sediments. This study examined how over irrigation (i.e., irrigation that produces runoff) in the summer season may transport recently applied pyrethroids. The study included liquid and granular applications of both bifenthrin [(2‐methyl‐3‐phenyl‐phenyl)methyl 3‐(2‐chloro‐3,3,3‐trifluoro‐prop‐1‐enyl)‐2,2‐dimethyl‐cyclopropane‐1‐carboxylate] and β‐cyfluthrin [Cyano(4‐fluoro‐3‐phenoxyphenyl)methyl 3‐(2,2‐dichloroethenyl)‐2,2‐dimethyl‐cyclopropanecarboxylate]. Generally, runoff did not occur at irrigation rates of 2.03 cm/h (0.8 in/h) but did occur when the irrigation rates were increased to about 3.81 cm/h (1.5 in/h), generating chemical losses in the first runoff event of up to 0.58 and 0.08% of applied for β‐cyfluthrin and bifenthrin, respectively. Chemical runoff losses dropped significantly between over‐irrigation events with the third over‐irrigation event chemical runoff losses representing 0.026 and 0.015% of applied for β‐cyfluthrin and bifenthrin, respectively. Runoff losses were generally less for liquid formulations than granular formulations but within a factor of three. Additionally, the study included a simulated winter rainstorm 8 wk after application. The low runoff losses from turf seen in this study suggest that other sources could be contributing to observed residues in urban streams. Other sources could include pyrethroids ending up on impervious surfaces, such as concrete driveways from off‐target applications to turf, spills, and other poor handling practices, or pyrethroids applied directly to impervious surfaces for insect control.
Solute‐Dependent Capillarity‐Induced Focused Flow during Infiltration into Alcohol‐Contaminated Soil
Authors: Smith J. E. , Henry E. J. , Bashir R.
Published: February 2011

Most organic compounds, when dissolved in water, decrease the surface tension of the water and many change the wettability of porous media. This directly affects capillary pressures and can induce water flow and solute transport in the vadose zone. This study investigated a coupled unsaturated flow and transport phenomenon, solute‐dependent capillarity‐induced focused flow (SCIFF), that has significant implications for infiltration into contaminated unsaturated zones. A two‐dimensional laboratory flow cell and the two‐dimensional hysteretic saturated–unsaturated flow and transport numerical model HYDRUS‐2D, which was modified to include solute concentration‐dependent hydraulic functions, were used to demonstrate and quantify the effect of SCIFF on point‐source infiltration of clean water into contaminated sand. The difference between the SCIFF infiltration event and traditional water infiltration into uncontaminated sand is striking. Highly focused vertical flow with very little horizontal migration was characteristic of the SCIFF infiltration event from a constant‐flux point source. The SCIFF resembles a single finger as in classic flow instability fingering; however, the SCIFF system has the added complexities of aqueous solute concentration‐dependent hydraulic functions. The SCIFF mechanism may well be active at many sites where the vadose zone has significant contamination with organic compounds. Another significant finding was that the magnitude and trend in moisture content changes measured by time domain reflectometry (TDR) did not match point values from the simulations because the TDR sample area extended beyond the width of the SCIFF zone. A good match between TDR and simulated values was obtained by determining the average simulated moisture content within the same region sampled by the TDR.
Finite‐Element Regression to Estimate Production Profiles of Greenhouse Gases in Soils
Authors: Schack-Kirchner Helmer , Kublin Edgar , Hildebrand Ernst E.
Published: February 2011

The gradient method used to quantify gas fluxes in soils is based on Fick's second law. The production term is proportional to the second derivative of the concentration profile. Existing methods reveal important limitations, however. We suggest dividing the soil into homogeneous finite elements consisting of second‐order polynomials for the gas concentration. A new statistical procedure combining the mechanistic constraints with quadratic splines was used to estimate the derivatives of scattered gas data. The method was tested in a Picea abies (L.) H. Karst. stand for CO2 and N2O depth profiles. The field results yielded a mean annual efflux of 5.9 Mg ha−1 yr−1 CO2−C, of which 86% originated from the mineral soil. The Ah horizon and the forest floor of both plots yielded around 0.8 kg ha−1 yr−1 N2O−N. In the subsoil, N2O−N production revealed a high spatial heterogeneity. To test for robustness, synthetic data sets were simulated for re‐estimation of belowground gas fluxes with the new procedure and with linear and exponential fits. When only the efflux at the surface was considered, both the finite element method and the local linear fit yielded results close to the expected value. For the deeper soil, the finite element fit yielded unbiased results as long as the preconditions were fulfilled. Otherwise, and this applied also to the alternative methods, results were rather arbitrary. Until now, no alternative to the gradient method for gas flux estimation in the deeper soil has been available. Therefore, deep soil gas flux estimations are questionable as long as the preconditions for the differentiating method are not thoroughly confirmed. As an alternative, we suggest an inverse parameter optimization based on a numerical solution of Fick's second law.
History and perspectives of hydrological catchment modelling
Authors: Todini E.
Published: February 2011

This paper presents a brief historical excursus on the development of hydrological catchment models together with a number of possible future perspectives. Given the wide variety of available hydrological models which, according to the embedded level of prior physical information, vary from the simple input–output lumped models to complex physically meaningful ones, the paper suggests how to accommodate and to reconcile the different approaches. This can be performed by better clarifying the roles and the limitations of the different models through objective benchmarks or test-beds characterizing the diverse potential hydrological applications. Furthermore, when dealing with hydrological forecasting, the reconciliation can be obtained in terms of forecasting uncertainty, by developing Bayesian frameworks to combine together models of different nature in order to assess and reduce predictive uncertainty.
Co-Immobilization of Glucose Oxidase-Catalase: Optimization of Immobilization Parameters to Improve the Immobilization Yield
Authors: Bankar Sandip B , Bule Mahesh V , Singhal Rekha S , Ananthanarayan Laxmi A
Published: February 2011

Co-immobilization of glucose oxidase (EC 1.1.3.4) and catalase (EC 1. 11.1.6) on non-porus glass surfaces using ?-aminopropyltriethoxysilane and polyethyleneimine as an activator and gluteraldehyde as cross linking agent has been carried out for its potential use. Polyethyleneimine was found to be a superior immobilization activator than ?-aminopropyltriethoxysilane. In present study, the effects of rough and smooth beads and optimization of the ratio of enzyme concentrations, activator material and concentration of the cross linking agent were investigated using response surface technology. With optimized concentration of glucose oxidase to catalase ratio (0.97), polyethyleneimine (150 mg/l) and gluteraldehyde (15 ml), the effect of glass bead concentration for maximum immobilization yield was investigated. Central composite optimization strategy with 16 experiments increased immobilization yield from 82.63% to 92.74%. It was observed that 0.3 ml of beads per 120 U of glucose oxidase were necessary for higher immobilization yield.
Disruption of Thyroid Hormone Activation in Type 2 Deiodinase Knockout Mice Causes Obesity With Glucose Intolerance and Liver Steatosis Only at Thermoneutrality
Authors: Castillo Melany , Hall Jessica A. , Correa-Medina Mayrin , Ueta Cintia , Won Kang Hye , Cohen David E. , Bianco Antonio C.
Published: February 2011

OBJECTIVE

Thyroid hormone accelerates energy expenditure; thus, hypothyroidism is intuitively associated with obesity. However, studies failed to establish such a connection. In brown adipose tissue (BAT), thyroid hormone activation via type 2 deiodinase (D2) is necessary for adaptive thermogenesis, such that mice lacking D2 (D2KO) exhibit an impaired thermogenic response to cold. Here we investigate whether the impaired thermogenesis of D2KO mice increases their susceptibility to obesity when placed on a high-fat diet.

RESEARCH DESIGN AND METHODS

To test this, D2KO mice were admitted to a comprehensive monitoring system acclimatized to room temperature (22°C) or thermoneutrality (30°C) and kept either on chow or high-fat diet for 60 days.

RESULTS

At 22°C, D2KO mice preferentially oxidize fat, have a similar sensitivity to diet-induced obesity, and are supertolerant to glucose. However, when thermal stress is eliminated at thermoneutrality (30°C), an opposite phenotype is encountered, one that includes obesity, glucose intolerance, and exacerbated hepatic steatosis. We suggest that a compensatory increase in BAT sympathetic activation of the D2KO mice masks metabolic repercussions that they would otherwise exhibit.

CONCLUSIONS

Thus, upon minimization of thermal stress, high-fat feeding reveals the defective capacity of D2KO mice for diet-induced thermogenesis, provoking a paradigm shift in the understanding of the role of the thyroid hormone in metabolism.
Regional, Geographic, and Racial/Ethnic Variation in Glycemic Control in a National Sample of Veterans With Diabetes
Authors: Egede Leonard E. , Gebregziabher Mulugeta , Hunt Kelly J. , Axon Robert N. , Echols Carrae , Gilbert Gregory E. , Mauldin Patrick D.
Published: February 2011

OBJECTIVE

We performed a retrospective analysis of a national cohort of veterans with diabetes to better understand regional, geographic, and racial/ethnic variation in diabetes control as measured by HbA1c.

RESEARCH DESIGN AND METHODS

A retrospective cohort study was conducted in a national cohort of 690,968 veterans with diabetes receiving prescriptions for insulin or oral hypoglycemic agents in 2002 that were followed over a 5-year period. The main outcome measures were HbA1c levels (as continuous and dichotomized at ≥8.0%).

RESULTS

Relative to non-Hispanic whites (NHWs), HbA1c levels remained 0.25% higher in non-Hispanic blacks (NHBs), 0.31% higher in Hispanics, and 0.14% higher in individuals with other/unknown/missing racial/ethnic group after controlling for demographics, type of medication used, medication adherence, and comorbidities. Small but statistically significant geographic differences were also noted with HbA1c being lowest in the South and highest in the Mid-Atlantic. Rural/urban location of residence was not associated with HbA1c levels. For the dichotomous outcome poor control, results were similar with race/ethnic group being strongly associated with poor control (i.e., odds ratios of 1.33 [95% CI 1.31–1.35] and 1.57 [1.54–1.61] for NHBs and Hispanics vs. NHWs, respectively), geographic region being weakly associated with poor control, and rural/urban residence being negligibly associated with poor control.

CONCLUSIONS

In a national longitudinal cohort of veterans with diabetes, we found racial/ethnic disparities in HbA1c levels and HbA1c control; however, these disparities were largely, but not completely, explained by adjustment for demographic characteristics, medication adherence, type of medication used to treat diabetes, and comorbidities.
Nontraditional Markers of Glycemia
Authors: Selvin Elizabeth , Francis Lesley M.A. , Ballantyne Christie M. , Hoogeveen Ron C. , Coresh Josef , Brancati Frederick L. , Steffes Michael W.
Published: February 2011

OBJECTIVE

To compare the associations of nontraditional (fructosamine, glycated albumin, 1,5-anhydroglucitol [1,5-AG]) and standard (fasting glucose, HbA1c) glycemic markers with common microvascular conditions associated with diabetes mellitus.

RESEARCH DESIGN AND METHODS

We conducted a cross-sectional study of 1,600 participants (227 with a history of diabetes and 1,323 without) from the Atherosclerosis Risk in Communities (ARIC) Study, a community-based population. We conducted logistic regression analyses of the associations of diabetes-specific tertiles of fructosamine, glycated albumin, 1/(1,5-AG), fasting glucose, and HbA1c with prevalence of chronic kidney disease, albuminuria, and retinopathy after adjustment for demographic, clinical, and lifestyle variables.

RESULTS

We observed significant positive trends in the associations of each marker with albuminuria and retinopathy, even after accounting for demographic, clinical, and lifestyle factors (all P trends <0.05). The associations with chronic kidney disease were similar in direction but were only significant for higher glycated albumin (P trend = 0.005), fructosamine (P trend = 0.003), and HbA1c (P trend = 0.005) values. After further adjustment for HbA1c, glycated albumin and fructosamine remained significantly or borderline significantly associated with the microvascular outcomes.

CONCLUSIONS

In cross-sectional analyses, two serum markers of glycemia—glycated albumin and fructosamine—are as, or more strongly, associated with microvascular conditions as HbA1c. These markers may be useful in settings where whole blood is not available. Whether they might complement or outperform HbA1c in terms of long-term predictive value requires further investigation.
Theoretical studies of excitation dynamics in a peridinin-chlorophyll-protein coupled to a metallic nanoparticle
Authors: Schmidt Mikolaj , Mackowski Sebastian
Published: February 2011

In this work we study the influence of plasmon excitations on the excitation dynamics within a protein complex embedding two chlorophyll molecules coupled to a gold nanosphere. Small separation between the chlorophylls and metallic nanoparticle allows us to simplify the calculations of the Förster energy transfer rate and non-radiative processes by replacing a spherical nanoparticle with a metallic surface. Our results show modifications of all relevant processes and the energy transfer pathways within the system as well as the radiative processes. Plasmon induced changes result in strong qualitative effects of the fluorescence of the studied light-harvesting complex.
Preparation of polymeric nanoparticles using a new polymerizable surfactant
Authors: Bunio Paulina , Zielińska Katarzyna , Chlebicki Jan , Wilk Kazimiera
Published: February 2011

A novel polymerizable surfactant (so-called surfmer) was synthesized and characterized according to its structure, surface activity and polymerization ability. Polymeric micelles (size of 6 and 130 nm) appeared in the polyreaction initiated by free radicals from VA-044. In the presence of the monomer (i.e., methyl methacrylate) microemulsion systems were formed that in turn were transformed into latex entities (size — 40 nm). Additionally, an emulsion polymerization was performed with the use of n-hexadecane as an oil phase resulting in the production of nanocapsules (size in the range — 165–220 nm). The shape and morphologies of the nanoobjects were confirmed using Atomic Force Microscopy (AFM).
Characterization of chemical and physical parameters of post copper slag
Authors: Lowinska-Kluge Aldona , Piszora Pawel , Darul Jolanta , Kantel Teresa , Gambal Pawel
Published: February 2011

Pilot studies concerning industrial scale application of post copper slag as a nano-additive for the modification of the corrosion resistance of cement composites have been described. The influence of a tribochemical treatment on some physicochemical properties as well as the corrosion resistance of the obtained composites have been evaluated based on DTG, RTG, and SEM coupled with EDX measurements and chemical analysis. It was observed that the so-called “size particle additive effect” influences the course and rate of transformations in the formed cement composites, and may lead to specific and desirable properties.
Uniform illumination by diffractive shaping of independent light beams
Authors: Sobczyk A. , Sypek M. , Siemion Ag. , Makowski M. , Siemion A. , Suszek J. , Kołodziejczyk A.
Published: February 2011

This article presents a new optical set-up for illumination of a common area with a few independent light sources. The main aim is to create a uniform light distribution of a constant shape even if one of the light sources will stop working. In such a case, the shape of the light distribution should remain unchanged, however, the total light intensity will be lower. The novelty of the proposed solution is based on the usage of a small number of the independent light sources in opposite to a well known LED arrays approach. The beam shaping is made using Dammann gratings and specially designed blazed phase diffractive gratings. The article contains the theoretical analysis and the computer simulation verified by the experiment.
A New Species of the Genus Proctophyllodes (Analgoidea, Proctophyllodidae) from Golden Oriole
Authors: Burdejnaja S. , Kivganov D.
Published: February 2011

A New Species of the Genus Proctophyllodes (Analgoidea, Proctophyllodidae) from Golden Oriole

The species Proctophyllodes orioli Burdejnaja et Kivganov, sp. n. from Golden Oriole Oriolus oriolus Linnaeus, 1758 (Passeriformes) was described (Zmiinyi Island, Ukraine). New species belonging to the group of species "musicus", is morphologically close to P. dasyxiphus Atyeo et Braasch, 1966 from (Eastem) Black-Headed Oriole Oriolus larvatus Lichtenstein, 1823.
New Faunistic Records of Tiger Moths in West Pakistan (Lepidoptera, Arctiidae, Arctiinae)
Authors: Gurko V. , Inayatullah M. , Mashwani M.
Published: February 2011

New Faunistic Records of Tiger Moths in West Pakistan (Lepidoptera, Arctiidae, Arctiinae)

Four species were collected in Balochistan Province: Axiopoena maura (Eichwald, 1830), Lacydes incurvata (Ebert, 1973), Utetheisa pulchella (Linnaeus, 1758) and Nebrarctia transversa (Moore, 1879). L. incurvata is recorded from Pakistan for the first time. Distribution and systematic position of all mentioned species are discussed.
A Kingdom Cleared of Castles: the Role of the Castle in the Campaigns of Robert Bruce
Authors: CORNELL DAVID
Published: February 2011

In 1314 the English-held castles of Roxburgh, Edinburgh and Stirling were seized and destroyed by Robert Bruce. This was the pinnacle of a policy by which Bruce systematically slighted the castles he seized in Scotland. The reign of Edward II has been seen as a period in which the military value of the castle was in decline and by analysing the role the castle played in the campaigns of Bruce it is possible to assess the importance a successful contemporary commander attached to the castle during this period. Bruce had first-hand experience of the castle at war and knew of its limitations. In 1306, however, he seized and garrisoned a number of castles preparing to use them for a specific purpose, but defeat in the field rendered them redundant. On his return in 1307 Bruce initiated a policy of destruction. Castles in the north of Scotland were slighted as they were the regional focus of the political power of his Scottish enemies, and militarily they were of little value to Bruce. In the Lowlands the first-rate castles of Scotland were destroyed precisely because they were so militarily powerful. Bruce recognised that these castles, used aggressively, were indispensable to the English war effort, and consequently he undertook a prolonged and expensive campaign to reduce them, a campaign which involved the tactic of both surprise assault and, more importantly, the set-piece siege. In 1314 the imminent English campaign led Bruce to launch an unprecedented offensive against the English-held castles of Roxburgh, Edinburgh and Stirling. These castles were subsequently slighted despite their inextricable association with the Scottish Crown. Bruce recognised that, unlike the English, he did not need to occupy castles in Scotland to fight the war. Although in Ireland a small number of castles were occupied, and Berwick was also garrisoned by Scottish troops, in northern England Bruce did not attempt to occupy English castles. Those which were seized were destroyed, an indication that Bruce never intended a conquest of Northumberland. Indeed Bruce never undertook a serious campaign aimed at the seizure of the first-rate castles of Northumberland despite their frequently perilous state. Instead he sought to gain political capital by threatening their loss and so placing enormous pressure on the English Crown. That the castle featured prominently in the campaigns of Bruce demonstrates it was not in decline. Bruce understood the continued military and political value of the castle, but he was able to exploit its inherent vulnerabilities in order to gain victory in war.