bluuebunny/crossref_metadata_2025 huggingface dataset:
The Pro's and Con's of Inverted oil Emulsion Mud-Statfjord ‘A’ Platform
Authors: Edelbrock Gregory J. , Gorgas Jan W. , Crackin Robert W. Mc
Published: May 2012

This paper presents an analysis of the-benefits and problems experienced with the use of inverted oil emulsion mud in drilling Statfjord ‘A’ Platform wells.

Problems encountered and their solution include both fluids handling (surface equipment) and fluid chemistry (hole stability). The Statfjord ‘A’ application is unique in that oil emulsion mud is used from surface to total depth, and a solvent immersion system is used to clean the cuttings prior to disposal.

The reasons for selecting this system are discussed. A cost/benefit analysis is included in the paper.
High Density Clear Fluids for Completions and Workovers
Authors: Place John , Paul James R. , Sigalas Antony
Published: May 2012

In recent years, the practical operating range of clear brines as completion and workover fluids has been significantly extended by the introduction of formulations incorporating bromide, so that the advantages of clear brines can now be obtained with fluids having densities as high as 19.2 lb/gal (2.3 g/cm3) at ambient temperatures, to give a series of fluids of proven cost-effectiveness.

The properties and formulation of a range of clear brines are described, including

calcium chloride – calcium bromide calcium chloride – calcium bromide – zinc bromide calcium bromide – zinc bromide sodium chloride – sodium bromide

Proper formulation of brines to achieve the best cost effectiveness is important and is emphasized in terms of the trade-off between costs and acceptable crystallization temperature. Handling, safety and environmental aspects of the various fluids are covered, as are practical operating aspects. The sodium salt brines are applicable in the special situation where calcium salts would be incompatible with connate water.

Incorporation of various additives is discussed – viscosifiers, fluid loss additives, corrosion inhibitors, as is the recovery and regeneration of fluids for re-use.

The heavy clear fluids are used for completion and workover, as packer fluids, and as drilling fluids (both aqueous and oil-invert systems). Case histories from North Sea operations are presented.
Rice Rotation and Tillage Effects on Soil Aggregation and Aggregate Carbon and Nitrogen Dynamics
Authors: Anders M. M. , Brye K. R. , Olk Dan C. , Schmid Bryan T.
Published: May 2012

Rice (Oryza sativa L.) production in Arkansas is tillage intensive. Traditional tillage (TT) has been shown to reduce soil quality. The objectives of this study were to assess the impact of TT and no‐till (NT) management on soil water‐stable aggregate (WSA) content, aggregate C and N concentrations, and aggregate C and N contribution to the bulk soil at two soil depths in seven rotations. For continuous rice or rotations containing rice every second year, total and mean WSA content in the 0‐ to 5‐cm soil layer was greater under NT than TT. There was no difference in total WSA content between soil depths for the TT treatment, with the 5‐ to 10‐cm layer (69 g kg−1) numerically greater than the NT 5‐ to 10‐cm layer. Water‐stable aggregate content increased when residue‐rich crops such as corn (Zea mays L.) and wheat (Triticum aestivum L.) were included in the rotation and decreased when soybean [Glycine max (L.) Merr.] was grown. The inclusion of wheat as a winter crop in rotation with rice resulted in the greatest bulk soil WSA C and N contents. Including soybean in rotation with rice resulted in reduced bulk soil WSA C and N contents. Bulk soil WSA C and N contents were determined more by the WSA content than the WSA C and N concentration. No‐till and increasing the frequency of rice in rotations resulted in greater soil WSA content and subsequent increased C and N content in the bulk soil.
Numerical Evaluation of Depth Effects of Double‐Ring Infiltrometers on Soil Saturated Hydraulic Conductivity Measurements
Authors: Lai Jianbin , Luo Yi , Ren Li
Published: May 2012

Previous research has indicated that the measurements of soil saturated hydraulic conductivity (Ks) are influenced by both the radial size and depth of a double‐ring infiltrometer. Few studies are available, however, on how the depth to which an infiltrometer is driven affects Ks measurement. In this study, six inner ring depths (di = 5, 10, 15, 25, 40, and 60 cm), six outer ring depths (do = 5, 10, 15, 25, 40, and 60 cm), and their combinations were designed. Thus 24 sets of driven depths of infiltrometer were involved. For each infiltrometer set, 31 stochastic fields of Ks were randomly generated in the simulation domain by adopting six correlation lengths (L = 0, 10, 20, 50, 100, and 200 cm) and six standard deviations (SD = 0, 0.1, 0.25, 0.5, 0.75, and 1.0). Therefore, a total of 7224 simulations were conducted to investigate the driven‐depth effect of the double‐ring infiltrometer on the measurements of soil saturated hydraulic conductivity of the wetted zone (Kw). Results demonstrated that the inner ring depth plays a more important role than the outer ring depth in Kw measurements by double‐ring infiltrometer, and increasing the inner ring depth could obtain a better approximation of accurate Kw measurements. Meanwhile, the outer ring added to a single‐ring infiltrometer was necessary in guaranteeing vertical water flow in the inner ring and improving measurement accuracy. Considering that the disturbance of soil caused by ring installation will increase with increasing ring depth, the ring depth of 5 to 15 cm that has been adopted in most ring‐infiltrometer‐related field experiments is acceptable and recommended for Kw measurements.
Pyrolysis‐Gas Chromatography/Mass Spectrometry Characterization of Humic Acids in Coastal Spodosols from Southeastern Brazil
Authors: González-Pérez Martha , Buurman P. , Vidal-Torrado P. , Martin-Neto L.
Published: May 2012

This study on humic acids (HAs) of podzol horizons from the southeastern region of Brazil investigated the accumulation and degradation of soil organic matter (SOM) in warm‐climate podzols. Humic acids from sandy coastal Spodosols (Histic Alaquod and Arenic Alorthod) from Cardoso Island in Sao Paulo State were characterized by pyrolysis in combination with gas chromatography and mass spectrometry (Py‐GC/MS). The soils developed on quartzitics, andy, nutrient‐poor parent materials under restinga forest in a coastal area. The Py‐GC/MS results show that the chemical composition of HAs in B horizons in one out of three profiles was influenced by both dissolved organic C (DOC) and C from in situ decaying roots. Carbon derived from DOC dominated in the deepest part of the B horizons. In the Arenic Alorthod (H9) profile, SOM from the B horizon seemed to be largely derived from roots. The DOC‐derived SOM was characterized by large contributions of phenol, methylphenols, and degraded polysaccharide products, while root contributions were mainly characterized by lignin products. Aliphatics were most abundant in A horizons (E and EB horizons were not analyzed). Both DOC‐derived and lignin‐derived SOM showed distinct degradation patterns. The Py‐GC/MS results corroborate those obtained by 13C variable amplitude cross polarization magic angle spinning nuclear magnetic resonance spectroscopy and Fourier‐transform infrared spectroscopy. Molecular chemistry showed that podzol B horizons are variable in composition, and local influences, such as drainage and vertical or lateral water transport, and SOM decomposition play an important role in podzolization processes in warm climates.
Net Nitrogen Mineralization from Past Years' Manure and Fertilizer Applications
Authors: Lentz Rodrick D. , Lehrsch Gary A.
Published: May 2012

The availability of soil N changes in years following a manure application. Experimental plots were established in a southern Idaho calcareous silt loam soil to measure these changes and aid N management in manure‐amended soils of the semiarid West. The study's six manure treatments included combinations of two manure rates, Man‐1× (0.31 Mg total N ha−1) and Man‐3× (0.97 Mg total N ha−1) applied in the fall either 1, 2, or 3 yr previously. Two non‐manure treatments were urea fertilizer applied per soil test (Fert) and a control with no amendment. We measured net N mineralization (0–30 cm) in the plots using buried bags in 2006, 2007, and 2009 for sprinkler‐irrigated crops. This resulted in (i) 2 yr of net N mineralization data for each manure rate applied 1, 2, or 3 yr before measurement, and (ii) 1 yr of data for each manure rate applied 4 or 5 yr previous to the measurement year. A 5‐yr decay series for each of the two manure rates was derived from functions fitted to the net N mineralization data, expressed as a fraction of total manure N applied. The decay series (Year 1–Year 5) for the Man‐1× treatment was 0.23, 0.12, 0.10, 0.09, and 0.08, while that for the Man‐3× rate was 0.20, 0.08, 0.05, 0.04, and 0.03. Soil at the 30‐ to 60‐cm depth contributed up to 28% of the total N mineralized in the 0‐ to 60‐cm soil layer of manure‐amended soils in the third year after application, with lesser amounts contributed in earlier years due to immobilization. The efficacy of N mineralization processes decreased as the manure application increased, thus using a single decay series to predict N availability across a range of manure application rates could lead to substantial estimation errors.
Nitrous Oxide Emissions from Claypan Soils Due to Nitrogen Fertilizer Source and Tillage/Fertilizer Placement Practices
Authors: Nash Patrick R. , Motavalli Peter P. , Nelson Kelly A.
Published: May 2012

Poorly drained soils can potentially have large amounts of applied fertilizer N lost through denitrification which can be a major contributor to soil nitrous oxide (N2O) emissions. These soil N2O emissions due to agricultural practices are significant because they contribute to global warming and ozone depletion. The objectives of this research were to quantify the effects of tillage/fertilizer placement (i.e., no‐till/surface broadcast and strip‐till/deep banded) and N fertilizer source [i.e., non‐coated urea (NCU), polymer‐coated urea (PCU), nontreated control] on soil N2O emissions from corn (Zea mays L.) production over the 2009 and 2010 growing seasons in a poorly drained claypan soil in Northeast Missouri. Averaged over 2009 and 2010, no significant differences were observed in cumulative soil N2O emissions, between treatment plots with NCU (5.21 kg N2O‐N ha−1) and PCU (5.48 kg N2O‐N ha−1). Soil N2O losses represented between 2.8 and 3.0% of annual fertilizer N applied, respectively. Strip‐till/deep banded N placement emitted 28% less N2O (0.2 kg N2O‐N) per Mg grain produced (P = 0.0284) compared to that of no‐till/surface broadcasted N. Impacts of alternative management practices on soil N2O losses may also need to consider changes in agricultural production to allow producers to decide which practices are best suited to balance their production and environmental goals.
Acoustic Measurements of Soil Pipeflow and Internal Erosion
Authors: Lu Zhiqu , Wilson G. V.
Published: May 2012

Internal erosion of soil pipes can lead to embankment failures, landslides, and gully erosion. Therefore, non‐intrusive methods are needed to detect and monitor soil pipeflow and the resulting internal erosion. This paper presents a laboratory study using both active and passive acoustic techniques to monitor and assess soil pipeflow and internal erosion. A 140 cm long by 100 cm wide soil bed, 25‐cm deep contained a single 6 mm diam. soil pipe at 15‐cm depth that extended from an upper water reservoir to the lower bed face. The soil pipe was maintained under a constant head of 2 cm and the flow rate and sediment concentration measured at 15 s intervals while measuring soil water pressures at several locations within the bed every 30 s. Acoustic measurements were conducted every 5 s, which consisted of two parts: actively monitoring the acoustic wave propagation at four locations along the soil pipe and passively recording water flow sounds at one location. For active measurements, the phase slope method was employed to measure the P‐wave velocity under noisy and dynamic conditions. The study showed that the variation of the P‐wave velocity reflected the ongoing internal erosion processes such as the onset of soil pipeflow, the buildup of positive water pressures within the soil pipe, the saturation of soil adjacent to the pipe, the variation of water pressures within and adjacent to the soil pipe as the soil drained following removal of the constant head, and relaxation of the soil. These observations can be analyzed and understood by using the concept of the effective stress and its relationship with the P‐wave velocity. For passive measurements, passive signals (including water flow sounds and ambient noises) were recorded by a sensor buried inside the soil and close to the soil pipe. Three signal processing algorithms were applied for the passive signal analysis, which revealed similar temporal characteristic of the water flow sounds. The passive study suggested that soil pipeflow can be identified and assessed from sound levels in terms of time‐domain root mean square (TD‐RMS) and frequency‐domain root mean square (FD‐RMS) and from the contrasts of the power spectrum image.
Effect of Aeration and Soil Water Redistribution on the Air Permeability under Subsurface Drip Irrigation
Authors: Niu Wenquan , Guo Qing , Zhou Xiaobo , Helmers Matthew J.
Published: May 2012

While subsurface drip irrigation supplies water to meet crop needs with high water use efficiency, it might cause low O2 levels around crop roots and affect plant growth and yield. A modified flow apparatus was used in the laboratory to investigate the impact of aeration following subsurface drip irrigation on transient air permeability. Disturbed samples from two soils from China, a Brown Forest soil (sandy loam) and Lou soil (silty clay loam), were repacked to construct soil columns with various bulk densities (1.3, 1.35, 1.4, 1.45, 1.5, and 1.55 g cm−3). Subsurface drip irrigation (350 mL) was performed at the 17‐cm soil depth. Aeration (1050 mL) was conducted through the emitter of the subsurface drip irrigation system for 5 min. The results showed that air permeability was affected by soil texture and bulk density. The measured air permeability from the modified apparatus was comparable to that from the classical apparatus. Soil air permeability after irrigation was reduced by 88.2, 70.1, and 42.5% for the Brown Forest soil with a bulk density of 1.3, 1.4, and 1.5 g cm−3, respectively, and 71.2, 65.4, and 54.3%, respectively, for the Lou soil. A short‐period aeration following irrigation quickly improved soil air permeability, however. The air permeability level within 10 min after aeration was 3.7, 2.0, and 1.5 times that before aeration for the Brown Forest soil with a bulk density of 1.3, 1.4, and 1.5 g cm−3, respectively, and 3.0, 2.5 and 2.0 times, respectively, for the Lou soil. It seems a feasible and economical approach to improve soil air permeability by aerating the soil through a subsurface irrigation system following irrigation.
Depthwise Carbon Dioxide Production and Transport in a Rangeland Soil
Authors: Verma A. K. , Kelleners T. J.
Published: May 2012

The objective of this study was to determine depthwise CO2 production in a semiarid rangeland soil near Laramie, WY, and to quantify the controls exerted by soil temperature and moisture. Depthwise CO2 flux and production were calculated for the 1 Nov. 2010 to 31 Oct. 2011 study period using continuous measurements of soil CO2 concentration, temperature, and water content. Calculated soil efflux using two different tortuosity models was compared with ecosystem respiration (Reco) as measured by a surface flux chamber. The efflux was mostly lower than the Reco values, as would be expected. Calculated CO2 production for the growing season was dominated by the 7.5‐ to 15‐cm depth (43 g C m‐2), compared with the 0‐ to 7.5‐cm depth (17 g C m‐2) and the 15‐ to 25‐cm depth (9 g C m‐2). The relatively high production at the 7.5‐ to 15‐cm depth was attributed to the fine‐textured soil at this depth, resulting in higher surface area, higher soil water retention, and possibly more favorable conditions for biological activity. The soil CO2 production increased with soil temperature, as expected, with temperature quotient (Q10) values of 2.98 and 3.03 for the 0‐ to 7.5‐ and 7.5‐ to 15‐cm depths, respectively. Temperature‐normalized CO2 production was found to be a function of soil water content (?w) at all depths. Maximum production was observed at ?w = 0.20 to 0.21 m3 m‐3 (0‐7.5‐cm depth), ?w = 0.17 to 0.23 m3 m‐3 (7.5‐15‐cm depth), and ?w = 0.19 to 0.22 m3 m‐3 (15‐25‐cm depth). The range of water contents for which soil respiration is at its peak should be confirmed for other rangelands.
Evaluation and thermodynamic calculation of ureolytic magnesium ammonium phosphate precipitation from UASB effluent at pilot scale
Authors: Desmidt E. , Ghyselbrecht K. , Monballiu A. , Verstraete W. , Meesschaert B. D.
Published: May 2012

The removal of phosphate as magnesium ammonium phosphate (MAP, struvite) has gained a lot of attention. A novel approach using ureolytic MAP crystallization (pH increase by means of bacterial ureases) has been tested on the anaerobic effluent of a potato processing company in a pilot plant and compared with NuReSys® technology (pH increase by means of NaOH). The pilot plant showed a high phosphate removal efficiency of 83 ± 7%, resulting in a final effluent concentration of 13 ± 7 mg · L−1 PO4-P. Calculating the evolution of the saturation index (SI) as a function of the remaining concentrations of Mg2+, PO4-P and NH4+ during precipitation in a batch reactor, resulted in a good estimation of the effluent PO4-P concentration of the pilot plant, operating under continuous mode. X-ray diffraction (XRD) analyses confirmed the presence of struvite in the small single crystals observed during experiments. The operational cost for the ureolytic MAP crystallization treating high phosphate concentrations (e.g. 100 mg · L−1 PO4-P) was calculated as 3.9 € kg−1 Premoved. This work shows that the ureolytic MAP crystallization, in combination with an autotrophic nitrogen removal process, is competitive with the NuReSys® technology in terms of operational cost and removal efficiency but further research is necessary to obtain larger crystals.
Effects of oxidant concentration and temperature on decolorization of azo dye: comparisons of UV/Fenton and UV/Fenton-like systems
Authors: Kuo C. Y. , Pai C. Y. , Wu C. H. , Jian M. Y.
Published: May 2012

This study applies photo-Fenton and photo-Fenton-like systems to decolorize C.I. Reactive Red 2 (RR2). The oxidants were H2O2 and Na2S2O8; Fe2+, Fe3+, and Co2+ were used to activate these two oxidants. The effects of oxidant concentration (0.3–2 mmol/L) and temperature (25–55 °C) on decolorization efficiency of the photo-Fenton and photo-Fenton-like systems were determined. The decolorization rate constants (k) of RR2 in the tested systems are consistent with pseudo-first-order kinetics. The rate constant increased as oxidant concentration and temperature increased. Activation energies of RR2 decolorization in the UV/H2O2/Fe2+, UV/H2O2/Fe3+, UV/Na2S2O8/Fe2+ and UV/Na2S2O8/Fe3+ systems were 32.20, 39.54, 35.54, and 51.75 kJ/mol, respectively.
Gene-expression programming for flip-bucket spillway scour
Authors: Guven Aytac , Azamathulla H. Md.
Published: May 2012

During the last two decades, researchers have noticed that the use of soft computing techniques as an alternative to conventional statistical methods based on controlled laboratory or field data, gave significantly better results. Gene-expression programming (GEP), which is an extension to genetic programming (GP), has nowadays attracted the attention of researchers in prediction of hydraulic data. This study presents GEP as an alternative tool in the prediction of scour downstream of a flip-bucket spillway. Actual field measurements were used to develop GEP models. The proposed GEP models are compared with the earlier conventional GP results of others (Azamathulla et al. 2008b; RMSE = 2.347, δ = 0.377, R = 0.842) and those of commonly used regression-based formulae. The predictions of GEP models were observed to be in strictly good agreement with measured ones, and quite a bit better than conventional GP and the regression-based formulae. The results are tabulated in terms of statistical error measures (GEP1; RMSE = 1.596, δ = 0.109, R = 0.917) and illustrated via scatter plots.
Isolation and characterization of a heterotrophic nitrifier from coke plant wastewater
Authors: Liu YuXiang , Li YaQing , Lv YongKang
Published: May 2012

This study investigated some factors affecting ammonium removal and nitrite accumulation by Alcaligenes faecalis C16, which was isolated from the activated sludge of a coking wastewater treatment plant. Nitrite was produced from ammonium only in the presence of citrate, acetate, meat extract, peptone or ethanol. The highest amount of nitrite was found with citrate as carbon source. A. faecalis C16 could not use glucose, fructose, sucrose and methanol. Under the optimum conditions of initial pH 6.0, C/N 14, 30 °C and 120 rpm, a maximum nitrite accumulation of 28.29 mg/L NO2−-N was achieved when the organism grew with citrate in four days. Nitrite accumulation increased with the increase of NH4+-N. Furthermore, A. faecalis C16 was shown to have phenol-degrading capacity during ammonium removal. Metabolism of phenol resulted in acidification of the media, which is not favorable for nitrification, whereas many other carbon sources made the medium more alkaline. However, no inhibitory effect by phenol was observed when phenol and acetate were used as mixed carbon source at different phenol/sodium acetate (P/S) ratios and their pH values were all controlled above 9.2 or P/S ratios below 5:5. These results suggested that A. faecalis C16 has some potential application in industrial wastewater treatment systems.
Rapid Tooling Method for Soft Customized Removable Oral Appliances
Authors: Salmi Mika , Tuomi Jukka , Sirkkanen Rauno , Ingman Tuula , Mäkitie Antti
Published: May 2012

Traditionally oral appliances i.e. removable orthodontic appliances, bite splints and snoring / sleep apnea appliances are made with alginate impressions and wax registrations. Our aim was to describe the process of manufacturing customized oral appliances with a new technique i.e. rapid tooling method. The appliance should ideally be custom made to match the teeth. An orthodontic patient, scheduled for conventional orthodontic treatment, served as a study subject. After a precise clinical and radiographic examination, the approach was to digitize the patient’s dental arches and then to correct them virtually by computer. Additive manufacturing was then used to fabricate a mould for a soft customized appliance. The mould was manufactured using stereolithography from Somos ProtoGen O-XT 18420 material. Casting material for the mould to obtain the final appliance was silicone. As a result we managed to create a customized soft orthodontic appliance. Also, the accuracy of the method was found to be adequate. Two versions of the described device were manufactured: one with small and one with moderate orthodontic force. The study person also gave information on the subjective patient adaptation aspects of the oral appliance.
Zoom Snowboards Incorporated: Understanding the Impact of Management Decisions on the Audit Plan
Authors: Jones Joanne C.
Published: May 2012

Zoom Snowboards Incorporated is a fictitious Canadian private company in the snowboard industry. While the company is fictitious, many of the facts are adopted from actual snowboard companies. The overall goal of this case is to give the students an opportunity to develop their ability to perform a rigorous analysis of an assurance case with multiple issues. Students assume the role of audit senior and are asked to prepare an audit planning memo for the partner. In order to perform a rigorous analysis, students will need to consider the broader issues related to business strategy, risk management, and corporate governance, as well as the regular components of an audit planning memo. Students will also need to consider how the various requests from client management, the bank, and the audit committee impact the financial statement audit as they are preparing their planning memo.
The impact of personality on adult patients' adjustability to orthodontic appliances
Authors: Cooper-Kazaz Rena , Ivgi Inbal , Canetti Laura , Bachar Eytan , Tsur Boaz , Chaushu Stella , Shalish Miriam
Published: May 2012

Objective:

To evaluate the impact of psychological traits on patients' choice of orthodontic appliances and their adjustability to orthodontic treatment.

Materials and Methods:

The sample consisted of 68 adult patients divided into three groups (28 buccal, 19 lingual, and 21 clear aligners). Prior to treatment participants filled out the Brief Symptom Inventory to assess symptoms of mental distress and the Narcissistic Vulnerability Scale to assess narcissistic personality traits. During the first week after appliance delivery and on day 14, patients completed a Health-Related Quality of Life questionnaire to assess their perception of pain and four areas of dysfunction. The correlation between personality traits and patients' reaction to treatment was evaluated.

Results:

Somatization was the only trait that affected the choice of lingual and clear aligner appliance. Reduced self-esteem regulation was associated with increased pain in all patients, while exploitation was associated with pain in lingual patients. Narcissistic vulnerability slightly influenced patients' adaptability to orthodontic appliances. Although adjustability to lingual appliances was the most difficult, only two parameters were affected by personality features. In the buccal group, adjustability was affected by numerous parameters. Adaptation to the clear aligner appliance was relatively uneventful and least affected by psychological features.

Conclusion:

Anxious individuals tend to prefer lingual and clear aligner appliances. The selection of lingual and clear aligner appliances governs the patient's response and recovery process, leaving little room for the effect of psychological features. On the other hand, the buccal appliance allows for greater impact of personality traits on adjustability.
Biodegradable polyhydroxybutyrate as a polyol for elastomeric polyurethanes
Authors: Vojtová Lucy , Kupka Vojtěch , Žídek Jan , Wasserbauer Jaromír , Sedláček Petr , Jančář Josef
Published: May 2012

In the proposed work, new elastomeric bio-polyol based polyurethanes (bio-PUs) with specific mechanical properties were prepared by a one-shot process without the presence of a solvent. Commercial non-degradable polyether polyol derived from petrochemical feed stock was partly (in the amount of 1 mass %, 5 mass %, and 10 mass %) substituted by the biodegradable polyhydroxybutyrate (PHB). Morphology of elastomeric PU composites was evaluated by scanning electron microscopy and mechanical properties of the prepared samples were obtained by both tensile measurements and prediction via the Mooney-Rivlin equation. Electron microscopy proved that the prepared materials have the character of a particle filled composite material, where PHB particles are regular with their size of about 1–2 μm in diameter. Tensile measurements demonstrated that the Young’s modulus, tensile stress at break, and tensile strain at break of each sample increase with the increase of the volume fraction of the filler. From the measured stress-strain data, the first and the second term of the Mooney-Rivlin equation were calculated. The obtained constants were applied to recalculate the stress-strain curves. It was found that the Mooney-Rivlin equation corresponds well with the stress-strain behavior of the prepared specimens.
Spectroscopic investigation of interaction of 6-methoxyflavanone and its β-cyclodextrin inclusion complex with calf thymus DNA
Authors: Yousuf Sameena , Enoch Israel
Published: May 2012

The interaction of 6-methoxyflavanone (6MF, 6-methoxy-2-phenyl-4H-1-benzopyran-4-one) with calf thymus DNA (ctDNA) was investigated by absorption spectroscopy, fluorescence spectroscopy, and cyclic voltammetry in the presence and absence of β-cyclodextrin (β-CD) acting as capping agent. Molecular modelling was used to optimise the study of 6MF-β-CD and 6MF-DNA interactions. Enhancement in the fluorescence intensity of 6MF was observed due to the formation of 1 : 1 complex with β-CD. In the presence and absence of DNA, 6MF showed different characteristics such as hyperchromic effect, red shift of absorption spectra and fluorescence quenching of 6MF due to binding between 6MF and ctDNA. The nature of the binding group was found to be different for the 6MF-ctDNA and 6MF-ctDNA-β-CD systems. An increase in fluorescence intensity was observed for the 6MF-ctDNA system while varying the concentration of β-CD due to encapsulation of a part of 6MF in cyclodextrin. The results are compatible with the possibility of the interaction of dihydrobenzopyran-4-one moiety of 6MF with ctDNA as well as with β-CD. Cyclic voltammetric studies confirmed the binding interaction between 6MF and ctDNA in the absence and presence of β-CD and molecular modelling explains the site of the interaction of 6MF with cyclodextrin and ctDNA.
Structures of copper(II) 2-chlorobenzoate monohydrate and copper(II) 3,5-dichlorobenzoate trihydrate
Authors: Medvecká Jana , Halaška Jozef , Jomova Klaudia , Moncol Jan
Published: May 2012

Structures of copper(II) 2-chlorobenzoate monohydrate and copper(II) 3,5-dichlorobenzoate trihydrate

The crystal structures of the title compounds, [Cu2(μ2-2-Clbz)4(H2O)2] (1) and [Cu(3,5-Cl2bz)2(H2O)3] (2), have been redetermined at 150 K. The compound1forms dimeric complex where two Cu2+cations are bridged through four 2-chlorobenzoate ligands. The Cu2+ion in1is pentacoordinated by four oxygen atoms of bridging 2-chlorobenzoate ligands and one coordinated water molecule. The compound2forms mononuclear complex, where the Cu2+ion is pentacoordinated by two oxygen atoms of monodentate 3,5-dichlorobenzoate ligands and three coordinated water molecule. Both complexes are connected through O—H· · ·O hydrogen bonds into frameworks. The π-π stacking interactions are also observed in crystal structure of2.
Theoretical study of 2-phenylpyrrole molecule using various quantum-chemical approaches
Authors: Rottmannová Lenka , Punyain Kraiwan , Rimarčík Ján , Lukeš Vladimír , Klein Erik , Kelterer Anne-Marie
Published: May 2012

Theoretical study of 2-phenylpyrrole molecule using various quantum-chemical approaches

A systematic theoretical study of 2-phenylpyrrole (PhPy) is presented for its neutral and monocharged states. The calculations were performed using the semiempirical Austin Model 1 (AM1) method, ab initio Møller-Plesset perturbation theory up to the second-order (MP2), density functional theory (DFT) and its tight-binding approximation (DFTB+). The comparison of the obtained equilibrium geometries showed that the C—C bond lengths in the phenylene ring are practically identical for the neutral state. Electric charging leads to significant changes in the geometry with respect to the neutral state. The C—N bonds in PhPy are elongated and the negative charging produces the out-of-plane distortion of N—H bond from the aromatic ring plane. The anionic state of the investigated molecule is connected with a higher perturbation of bond length alternation in both rings in comparison to the cationic state. The vibrationaly broadened absorption spectra, based on the on-the-fly molecular dynamics (MD) simulations, are also presented and compared with experimental spectra. Although the DFTB+ method has the tendency to planarize the investigated molecular structure, the agreement of simulated absorption spectra based on the MD DFTB+ geometries with TD-DFT calculations is acceptable.
Lipophilization of flavonoids for their food, therapeutic and cosmetic applications
Authors: Danihelová Martina , Viskupičová Jana , Šturdík Ernest
Published: May 2012

Lipophilization of flavonoids for their food, therapeutic and cosmetic applications

Flavonoids represent large group of plant pigments. These polyphenolic compounds may be found in the nature as active components of fruits, vegetables and other plants and derived products. Due to established biological effects they are attractive substances for many areas of human life. Many flavonoids are nowadays used in pharmaceutical, cosmetic and food preparations. Their practical applications are in most cases limited by low solubility and stability in lipophilic media. Chemical or enzymatic lipophilization of flavonoid skeleton may not only increase their solubility and stability in lipophilic environment but also their biological properties. This review summarizes current knowledge in this field.
L'extrême droite allemande : une stratégie de communication moderne
Authors: Iost Delphine
Published: May 2012

Aujourd’hui encore, la société allemande reste profondément marquée par le traumatisme du génocide des Juifs au cours de la Seconde Guerre mondiale et les organisations politiques ouvertement racistes et xénophobes n’ont pas voix au chapitre dans les médias de masse. Afin de contourner cette mise au ban médiatique, l’extrême droite allemande a développé une stratégie d’utilisation ciblée des outils de communication moderne (musique, Internet) afin de s’adresser à un public jeune. Outre cette occupation d’un espace virtuel, le Parti national-démocrate (NPD) et son organisation de jeunesse (JN) s’investissent massivement dans l’organisation d’une série de manifestations, véritables démonstrations de force dans l’espace public. Cette évolution ne reste toutefois pas sans rencontrer de résistance et les citoyens sont nombreux à se mobiliser contre ces apparitions publiques. Par le biais de contre-manifestations, mais aussi par une réflexion plus profonde sur les moyens à mettre en place au quotidien, nombreux sont ceux qui s’organisent pour protester contre l’extrême droite.
Les transformations urbaines et l'émergence des partis populistes de la droite radicale en Europe. Le cas de la ville de La Haye
Authors: Van Gent Wouter , Musterd Sako
Published: May 2012

Cet article reprend trois explications traditionnelles de l’émergence des partis populistes de la droite radicale dans une perspective urbaine, et tente de comprendre les changements spatiaux à l’intérieur même de la ville. Nous avançons l’idée que ces changements sont plus importants que la composition sociale des différents quartiers, et qu’ils résultent de processus sociaux et spatiaux découlant de trois décennies de transformation urbaines dans les villes d’Europe. En examinant la géographie électorale des partis populistes de la droite radicale à La Haye en 2010, nous avons identifié trois types de quartiers différents ceux caractérisés par la diversité ethnique, l’isolement social et la protestation politique. En conclusion nous proposons quelques pistes de recherches.
Deux visions de l'extrême droite dans l'ex-Yougoslavie : les cas de la Slovénie et de la Serbie
Authors: Hassid Laurent
Published: May 2012

Dans les deux anciennes républiques yougoslaves de Slovénie et de Serbie, indépendantes depuis 20 ans, l’extrême droite se manifeste de manière très différente. En Slovénie, le parti d’extrême droite, le SNS de Zmago Jelincic, n’est qu’un acteur secondaire du nationalisme, laissant le rôle essentiel au leader du parti conservateur (SDS) de Janez Jansa, Premier ministre de 2004 à 2008, comme l’a démontré l’exploitation politique de l’affaire des effacés. En Serbie, au contraire, le Parti radical de Vojislav Seselj a failli gagner des élections nationales à plusieurs reprises et des groupuscules, souvent violents, disséminés dans la société civile, se revendiquent d’extrême droite. L’indépendance du Kosovo en février 2008 a contribué à scinder l’extrême droite serbe avec la création du Parti progressiste dirigé par l’ancien dauphin de Seselj, Tomislav Nikolic, qui se présente désormais en chef d’un parti conservateur face au parti pro-européen du président Boris Tadic. Entre un parti conservateur slovène qui glisse vers un nationalisme excessif et l’extrême droite serbe qui se cherche une respectabilité, les débats autour de la nation restent primordiaux dans ces deux États balkaniques.
Lettre d'Athènes
Authors: Houdoy Xavier
Published: May 2012

Le LAOS, fondé en 2000, figure au sein de l’exécutif qui a vu le jour au lendemain de la chute du gouvernement de Georges Papandréou et doit assurer la transition politique du pays jusqu’aux législatives anticipées d’avril 2012. L’accession au pouvoir de ce parti peu représentatif a permis de dénouer la crise politique qui se dessinait, fruit d’une situation économique et financière de plus en plus difficile à gérer par les deux partis majoritaires. Au-delà, elle se fait le reflet de la profonde désillusion de la société grecque, qui désavoue massivement les deux partis majoritaires – PASOK et Nouvelle Démocratie – et dont une petite partie semble progressivement adhérer aux discours nationalistes et xénophobes tenus par une extrême droite qui monte en puissance.
Stromal Endothelial Cells Establish a Bidirectional Crosstalk with Chronic Lymphocytic Leukemia Cells through the TNF-Related Factors BAFF, APRIL, and CD40L
Authors: Cols Montserrat , Barra Carolina M. , He Bing , Puga Irene , Xu Weifeng , Chiu April , Tam Wayne , Knowles Daniel M. , Dillon Stacey R. , Leonard John P. , Furman Richard R. , Chen Kang , Cerutti Andrea
Published: May 2012

Chronic lymphocytic leukemia (CLL) is a clonal B cell disorder of unknown origin. Accessory signals from the microenvironment are critical for the survival, expansion, and progression of malignant B cells. We found that the CLL stroma included microvascular endothelial cells (MVECs) expressing BAFF and APRIL, two TNF family members related to the T cell-associated B cell-stimulating molecule CD40L. Constitutive release of soluble BAFF and APRIL increased upon engagement of CD40 on MVECs by CD40L aberrantly expressed on CLL cells. In addition to enhancing MVEC expression of CD40, leukemic CD40L induced cleavases that elicited intracellular processing of pro-BAFF and pro-APRIL proteins in MVECs. The resulting soluble BAFF and APRIL proteins delivered survival, activation, Ig gene remodeling, and differentiation signals by stimulating CLL cells through TACI, BAFF-R, and BCMA receptors. BAFF and APRIL further amplified CLL cell survival by upregulating the expression of leukemic CD40L. Inhibition of TACI, BCMA, and BAFF-R expression on CLL cells; abrogation of CD40 expression in MVECs; or suppression of BAFF and APRIL cleavases in MVECs reduced the survival and diversification of malignant B cells. These data indicate that BAFF, APRIL, and CD40L form a CLL-enhancing bidirectional signaling network linking neoplastic B cells with the microvascular stroma.
Point of care testing of HIV in children younger than 18 months with three different HIV virological assays. Experience from a district hospital in a resource-limited setting
Authors: Alvarez-Uria Gerardo , Azcona Jose M. , Reddy Srinivasulu , Midde Manoranjan , Naik Praveen K. , Reddy N. Raghuprakash
Published: May 2012

Diagnosis of HIV in children younger than 18 months can be challenging in developing countries because requires the use of HIV virological tests. In this study we describe the experience with three commercial assays, HIV- 1 DNA polymerase chain reaction (PCR) (Roche Amplicor 1.5) with dried blood spot, HIV-1 RNA PCR (Roche COBAS TaqMan) with plasma and reverse transcriptase activity assay (Cavidi Exavir Load 3) with plasma in a rural setting of India. Sensitivity and specificity were 98.1% (95% confidence interval [CI] 90- 100) and 99.3% (95% CI 97.9-99.9) for the HIV- 1 RNA PCR assay, 66.7% (95% CI 29.9-92.5) and 100% (95% CI 96.8-100) for the HIV-1 DNA PCR assay, and 100% (95% CI 48-100) and 98.7% (95% CI 92.8-100) for the reverse transcriptase activity assay respectively. The low sensitivity of the HIV-1 DNA PCR assay in this setting is worrisome and warrants further investigations.
A Case of Primary Clear Cell Hepatocellular Carcinoma in a Non-Cirrhotic Liver: an Immunohistochemical and Ultrastructural Study
Authors: Clayton Erica Fan , Furth Emma Elizabeth , Ziober Amy , Xu Theodore , Yao Yuan , Hwang Pil Gyu , Bing Zhanyong
Published: May 2012

The clear cell variant of hepatocellular carcinoma is a rare entity, occurring at a frequency of less than 10% of hepatocellular carcinoma, with a female prevalence and usually associated with hepatitis C and cirrhosis. We reported a case of primary clear cell hepatocellular carcinoma occurring in a non-cirrhotic liver without history of hepatitis. Our examination included gross pathology, histopathology, immunohistochemistry, special stains, and electron microscopy evaluation. The tumor was composed of sheets of medium-to-large cells with foamy and reticulated cytoplasm and small-to-medium sized nuclei with variably prominent nucleoli. Oil red O stain showed abundant intracellular lipid. Periodic Acid-Schiff stain confirmed the presence of abundant glycogen deposition. Immunohistochemically the tumor cells were positive for Hep Par1, negative for epithelial membrane antigen, steroidogenic factor-1, HMB45, melan A, CK7 and CK20. Electron microscopy study was performed, which was first done in a clear cell hepatocellular carcinoma occurring in a non-cirrhotic liver without elevation of liver function tests. Ultrastructural evaluation of the clear cells showed scarce cellular organelles, cytoplasmic lipid vacuoles and swollen mitochondria.
Unique Sex-Based Approach Identifies Transcriptomic Biomarkers Associated with Non-Syndromic Craniosynostosis
Authors: Stamper Brendan D. , Park Sarah S. , Beyer Richard P. , Bammler Theo K. , Cunningham Michael L.
Published: May 2012

Background

The premature fusion of one cranial suture, also referred to as non-syndromic craniosynostosis, most commonly involves premature fusion of the sagittal, coronal, or metopic sutures, in that order. Population-based epidemiological studies have found that the birth prevalence of single-suture craniosynostosis is both suture- and sex-dependent.

Methods

Transcriptomic data from 199 individuals with isolated sagittal (n = 100), unilateral coronal (n = 50), and metopic (n = 49) synostosis were compared against a control population (n = 50) to identify transcripts accounting for the different sex-based frequencies observed in this disease.

Results

Differential sex-based gene expression was classified as either gained (divergent) or lost (convergent) in affected individuals to identify transcripts related to disease predilection. Divergent expression was dependent on synostosis sub-type, and was extensive in metopic craniosynostosis specifically. Convergent microarray-based expression was independent of synostosis sub-type, with convergent expression of FBN2, IGF2BP3, PDE1C and TINAGL1 being the most robust across all synostosis sub-types.

Conclusions

Analysis of sex-based gene expression followed by validation by qRT-PCR identified that concurrent upregulation of FBN2 and IGF2BP3, and downregulation of TINAGL1 in craniosynostosis cases were all associated with increased RUNX2 expression and may represent a transcriptomic signature that can be used to characterize a subset of single-suture craniosynostosis cases.
Organizational learning culture and innovativeness in Turkish firms
Authors: Černe Matej , Jaklič Marko , Škerlavaj Miha , Aydinlik Arzu Ülgen , Polat Dilek Dönmez
Published: May 2012

The aim of this paper is to present and test a model that examines the relationship between organizational learning culture and innovativeness. Organizational learning culture consists of the organizational learning process and of different culture types that can be placed within the competing values framework. It is defined as a set of norms and values within an organization that support systematic, in-depth approaches aimed at achieving higher-level organizational learning. Innovativeness consists of both innovative culture and innovations. Innovations, the process or outcome of innovating, are more likely to occur and be more successful if there is a strong innovative culture, meaning that the behavioral patterns of the employees are directed towards innovating. We used data from 112 Turkish firms employing more than 50 people. The relationship between organizational learning culture and innovativeness is empirically tested via structural equation modeling (SEM). We found support for a very strong positive relationship between organizational learning culture and innovative culture, as well as for the indirect relation between organizational learning culture and innovations via innovative culture.
Probabilistic Solution of Rational Difference Equations System with Random Parameters
Authors: Kadry Seifedine
Published: May 2012

We study the periodicity of the solutions of the rational difference equations system of type , (), and then we propose new exact procedure to find the probability density function of the solution, where a, b, and are independent random variables.
On g-Semisymmetric Rings
Authors: Aly Farahat S. , Al Mestady Mohammed O.
Published: May 2012

We introduce right (left) g-semisymmetric ring as a new concept to generalize the well-known concept: symmetric ring. Examples are given to show that these classes of rings are distinct. They coincide under some conditions. It is shown that R is bounded right g-semisymmetric with boundary 1 from right if and only if R is symmetric, whenever R is regular. It is shown that a ring R is strongly regular if and only if R is regular and bounded right g-semisymmetric with boundary 1 from right. For a right p.p.-ring R it is shown that R is reduced if and only if R is symmetric, if and only if R is bounded right g-semisymmetric ring with boundary 1 from left, if and only if R is IFP, if and only if R is abelian. We prove that
there is a special subring of the ring of 3×3 matrices over a ring without zero divisors which is bounded right g-semisymmetric with boundary 2 from left and boundary 2 from right. Also we show that flat left modules over bounded left g-semisymmetric ring with boundaries 1 from left and 1 from right are bounded left g-semisymmetric with boundaries 1 from left and 1 from right.
Antagonistic Roles for GcvA and GcvB inhdeABExpression inEscherichia coli
Authors: Stauffer Lorraine T. , Stauffer George V.
Published: May 2012

InE. coli, the periplasmic proteins HdeA and HdeB have chaperone-like functions, suppressing aggregation of periplasmic proteins under acidic conditions. A microarray analysis of RNA isolated from anE. coliwild type and a ΔgcvB strain grown to mid-log phase in Luria-Bertani broth indicated thehdeABoperon, encoding the HdeA and HdeB proteins, is regulated by the sRNA GcvB. We wanted to verify that GcvB and its coregulator Hfq play a role in regulation of thehdeABoperon. In this study, we show that GcvB positively regulateshdeA::lacZandhdeB::lacZtranslational fusions in cells grown in Luria-Bertani broth and in glucose minimal media + glycine. Activation also requires the Hfq protein. Although many sRNAs dependent on Hfq regulate by an antisense mechanism, GcvB regulateshdeABeither directly or indirectly at the level of transcription. GcvA, the activator ofgcvB, negatively regulateshdeABat the level of transcription. Although expression ofgcvBis dependent on GcvA, activation ofhdeABby GcvB occurs independently of GcvA’s ability to repress the operon. Cell survival and growth at low pH are consistent with GcvA negatively regulating and GcvB positively regulating thehdeABoperon.