bluuebunny/crossref_metadata_2025_split huggingface dataset:
The lipoprotein lipase gene in combined hyperlipidemia: evidence of a protective allele depletion
Authors: Wung Shu-Fen , Kulkarni Medha V , Pullinger Clive R , Malloy Mary J , Kane John P , Aouizerat Bradley E 
Published: August 2006

Abstract

Background
Lipoprotein Lipase (LPL), a key enzyme in lipid metabolism, catalyzes the hydrolysis of triglycerides (TG) from TG-rich lipoproteins, and serves a bridging function that enhances the cellular uptake of lipoproteins. Abnormalities in LPL function are associated with pathophysiological conditions, including familial combined hyperlipidemia (FCH). Whereas two LPL susceptibility alleles were found to co-segregate in a few FCH kindred, a role for common, protective alleles remains unexplored. The LPL Ser447Stop (S447X) allele is associated with anti-atherogenic lipid profiles and a modest reduction in risk for coronary disease. We hypothesize that significant depletion of the 447X allele exists in combined hyperlipidemia cases versus controls. A case-control design was employed. The polymorphism was assessed by restriction assay in 212 cases and 161 controls. Genotypic, allelic, and phenotypic associations were examined.

Results
We found evidence of significant allelic (447Xcontrol: 0.130 vs. 447Xcase: 0.031, χ2 = 29.085; 1df; p < 0.001) and genotypic association (SS: 0.745 vs. 0.939, and SX+XX: 0.255 vs. 0.061) in controls and cases, respectively (χ2 = 26.09; 1df; p < 0.001). In cases, depletion of the 447X allele is associated with a significant elevation in very-low-density lipoprotein cholesterol (VLDL-C, p = 0.045). Consonant with previous studies of this polymorphism, regression models predict that carriers of the 447X allele displayed significantly lower TG, low-density lipoprotein cholesterol (LDL-C) and TG/high-density lipoprotein cholesterol (HDL-C) ratio.

Conclusion
These findings suggest a role for the S447X polymorphism in combined hyperlipidemia and demonstrate the importance of evaluating both susceptibility and protective genetic risk factors.
On the surjectivity of the canonical Gaussian map for multiple coverings
Authors: Ballico Edoardo , Fontanari Claudio 
Published: August 2006

Abstract
Here we investigate the canonical Gaussian map for higher multiple coverings of curves, the case of double coverings being completely understood thanks to previous work by Duflot. In particular, we prove that every smooth curve can be covered with degree not too high by a smooth curve having arbitrarily large genus and surjective canonical Gaussian map. As a consequence, we recover an asymptotic version of a recent result by Ciliberto and Lopez and we address the Arbarello subvariety in the moduli space of curves.
Completely regular ovals
Authors: Maschietti Antonio 
Published: August 2006

Abstract
The following result concerning completely regular ovals is proved: Let Π be a projective plane of even order and let 𝒪 be a completely regular oval with nucleus N. Then Π is (N,N)-transitive. Combining this result with previous results [A. Maschietti, Symplectic translation planes and line ovals. Adv. Geom.
3 (2003), 123–143. MR1967995 (2004c:51008) Zbl 1030.51002] one obtains: A projective plane of even order admits a completely regular oval if and only if the plane is dual to a symplectic translation plane.
Dependence of Ammonia Emissions From Housing on the Time Cattle Spent Inside
Authors: Gilhespy Sarah , Webb J. , Retter Andrew , Chadwick David 
Published: August 2006

ABSTRACTBuildings housing cattle contribute 19% (42 kt NH3–N yr−1) of total UK ammonia (NH3) emissions. In the UK there is not usually an abrupt switch from cattle being kept inside to when they are turned out to graze 24 h a day. Moreover, during the summer dairy cows return to the farm twice a day to be milked and may spend some time inside buildings. Hence, there is uncertainty over the treatment of the transitional and summer periods when inventorying NH3 emissions. The aim of this study was to measure, under controlled and replicated conditions, the relationship between the number of hours cattle spend in buildings and the NH3 emissions from those buildings. Our results indicate that NH3 emissions decrease as the proportion of the day cattle spend in the buildings decreases, although the trend is not linear. Daily emission rates from cattle housed for 2 h ranged from 1.6 to 6.2 g NH3–N lu−1 whereas emissions from cattle housed for 24 h ranged from 8.1 to 24.1 g NH3–N lu−1 To significantly reduce NH3 emissions in comparison to those from buildings where cattle are housed for 24 h, the occupancy would have to be reduced to no more than 6 h each day. Thus, the strategy of extending the grazing season by allowing cattle to graze for c. 4 to 12 h during the winter is unlikely to reduce NH3 emissions from buildings or overall.
Nitrogen Loads through Baseflow, Stormflow, and Underflow to Rehoboth Bay, Delaware
Authors: Volk J. A. , Savidge K. B. , Scudlark J. R. , Andres A. S. , Ullman W. J. 
Published: August 2006

ABSTRACTA detailed study of water and nitrogen (N) discharge from a small, representative subwatershed of Rehoboth Bay, Delaware, was conducted to determine total N loads to the bay. The concentrations of ammonium (NH4+), nitrate + nitrite (NO3− + NO2−), and dissolved and particulate organic N were determined in baseflow and storm waters discharging from Bundicks Branch from October 1998 to April 2002. A novel hydrographic separation model that accounts for significant decreases in baseflow during storm events was developed to estimate N loads during unsampled storms. Nitrogen loads based on gauged flows alone (7100–19 100 kg/yr) significantly underestimated those based on land use–land cover (LULC) and estimated N export factors from different classes of LULC (32 000–40 600 kg/yr). However, when ungauged underflow and associated N loads were included in the total loads (25500–33800 kg/yr), there was much better agreement with LULC export models. This suggests that in permeable coastal plain sediments, underflow contributes significantly to N fluxes to estuarine receiving waters, particularly in drier years. Based on the similarity in LULC, N loads from the Bundicks Branch subwatershed were used to estimate upland loads to the entire Rehoboth Bay Watershed (259 000–316000 kg/yr). These N loads from the watershed were much greater than those from direct atmospheric deposition (49000–64 500 kg/yr) and from a local wastewater treatment plant (9700–13700 kg/yr). While the watershed was the principal source of N at all times during the year, the relative contributions from the watershed, wastewater, and direct atmospheric deposition varied predictably with season.
The Current Status and Environmental Impacts of Glyphosate‐Resistant Crops
Authors: Cerdeira Antonio L. , Duke Stephen O. 
Published: August 2006

ABSTRACTGlyphosate [N‐(phosphonomethyl) glycine]‐resistant crops (GRCs), canola (Brassica napusL.), cotton (Gossypium hirsutumL.), maize (Zea maysL.), and soybean [Glycine max(L.) Merr.] have been commercialized and grown extensively in the Western Hemisphere and, to a lesser extent, elsewhere. Glyphosate‐resistant cotton and soybean have become dominant in those countries where their planting is permitted. Effects of glyphosate on contamination of soil, water, and air are minimal, compared to some of the herbicides that they replace. No risks have been found with food or feed safety or nutritional value in products from currently available GRCs. Glyphosate‐resistant crops have promoted the adoption of reduced‐ or no‐tillage agriculture in the USA and Argentina, providing a substantial environmental benefit. Weed species in GRC fields have shifted to those that can more successfully withstand glyphosate and to those that avoid the time of its application. Three weed species have evolved resistance to glyphosate in GRCs. Glyphosate‐resistant crops have greater potential to become problems as volunteer crops than do conventional crops. Glyphosate resistance transgenes have been found in fields of canola that are supposed to be non‐transgenic. Under some circumstances, the largest risk of GRCs may be transgene flow (introgression) from GRCs to related species that might become problems in natural ecosystems. Glyphosate resistance transgenes themselves are highly unlikely to be a risk in wild plant populations, but when linked to transgenes that may impart fitness benefits outside of agriculture (e.g., insect resistance), natural ecosystems could be affected. The development and use of failsafe introgression barriers in crops with such linked genes is needed.
Nitrous Oxide Fluxes in Turfgrass
Authors: Bremer Dale J. 
Published: August 2006

ABSTRACTUrban ecosystems are rapidly expanding and their effects on atmospheric nitrous oxide (N2O) inventories are unknown. Our objectives were to: (i) measure the magnitude, seasonal patterns, and annual emissions of N2O in turfgrass; (ii) evaluate effects of fertilization with a high and low rate of urea N; and (iii) evaluate effects of urea and ammonium sulfate on N2O emissions in turfgrass. Nitrogen fertilizers were applied to turfgrass: (i) urea, high rate (UH; 250 kg N ha−1 yr−1); (ii) urea, low rate (UL; 50 kg N ha−1 yr−1); and (iii) ammonium sulfate, high rate (AS; 250 kg N ha−1 y−1); high N rates were applied in five split applications. Soil fluxes of N2O were measured weekly for 1 yr using static surface chambers and analyzing N2O by gas chromatography. Fluxes of N2O ranged from −22 μg N2O‐N m−2 h−1 during winter to 407 μg N2O‐N m−2 h−1 after fall fertilization. Nitrogen fertilization increased N2O emissions by up to 15 times within 3 d, although the amount of increase differed after each fertilization. Increases were greater when significant precipitation occurred within 3 d after fertilization. Cumulative annual emissions of N2O‐N were 1.65 kg ha−1 in UH, 1.60 kg ha−1 in AS, and 1.01 kg ha−1 in UL. Thus, annual N2O emissions increased 63% in turfgrass fertilized at the high compared with the low rate of urea, but no significant effects were observed between the two fertilizer types. Results suggest that N fertilization rates may be managed to mitigate N2O emissions in turfgrass ecosystems.
Modeling the Environmental Fate of Cadmium in a Large Wastewater Irrigation Area
Authors: Ingwersen Joachim , Streck Thilo 
Published: August 2006

ABSTRACTThe fate of cadmium in soils is governed by spatially heterogeneous processes that proceed from decades to centuries. This study aimed at modeling the fate of Cd within the wastewater irrigation area (WIA) of Braunschweig (Germany). The sandy soils (mainly Dystric Cambisol or Typic Haplumbrept) at this site (28 km2) have received considerable loads of heavy metals by irrigation of municipal wastewater for up to 40 yr. The soils of the WIA are in agricultural use. The main crops are sugar beet (Beta vulgaris L.), potato (Solanum tuberosum L.), and wheat (Triticum aestivum L.). As a result of asparagus (Asparagus officinalis L.) cropping, about 15% of the soils have been converted to Rigosols. In 1996, we measured the vertical distribution (0 to 1.2 m) of soil pH, organic carbon content, and the EDTA–extractable content and the solution phase concentration of Cd at 153 sites. At sites not used for asparagus cultivation, Cd has migrated on average to a depth of about 0.5 m. Due to deep plowing, which accelerates migration, Cd has been displaced on average to about 0.7 m at the Rigosol sites. To model the fate of Cd at the scale of the WIA, we used different parallel soil column approaches. In each column the local model SEFAH was used to simulate both displacement and plant uptake of Cd. The model was fed with measured or randomly generated soil data. The results of retrospective simulations from 1957 to 1996 agreed well with observed Cd profiles. The better the spatial variability of sorption was described, the better the performance. Our simulation results show that Cd pollution of soil at first affects the soil‐plant pathway. The breakthrough of Cd to the groundwater is dampened and is delayed for many decades.
Sorption Dynamics of Organic and Inorganic Phosphorus Compounds in Soil
Authors: Berg A. S. , Joern B. C. 
Published: August 2006

ABSTRACTPhosphorus retention in soils is influenced by the form of P added. The potential impact of one P compound on the sorption of other P compounds in soils has not been widely reported. Sorption isotherms were utilized to quantify P retention by benchmark soils from Indiana, Missouri, and North Carolina when P was added as inorganic P (Pi) or organic P (β‐D‐glucose‐6‐phosphate, G6P; adenosine 5′‐triphosphate, ATP; and myoinositol hexaphosphate, IP6) and to determine whether soil P sorption by these organic P compounds and Pi was competitive. Isotherm supernatants were analyzed for pH and total P using standard protocols, while Pi and organic P compounds were assayed using ion chromatography. Under the controlled conditions of this study, the affinity of all soils for P sources followed the order IP6 > G6P > ATP > Pi. Each organic P source had a different potential to desorb Pi from soils, and the order of greatest to least Pi desorption was G6P > ATP > IP6 Glucose‐6‐phosphate and ATP competed more directly with Pi for sorption sites than IP6 at greater rates of P addition, but at the lesser rates of P addition, IP6 actually desorbed more Pi. Inositol hexaphosphate was strongly sorbed by all three soils and was relatively unaffected by the presence of other P sources. Decreased total P sorption due to desorption of Pi can be caused by relatively small additions of organic P, which may help explain vertical P movement in manured soils. Sorption isotherms performed using Pi alone did not accurately predict total P sorption in soils.
Assessment of the Sulfur Hexafluoride (SF6) Tracer Technique for Measuring Enteric Methane Emissions from Cattle
Authors: McGinn S. M. , Beauchemin K. A. , Iwaasa A. D. , McAllister T. A. 
Published: August 2006

ABSTRACTA commonly used method of measuring enteric methane (CH4) emissions from ruminants is the SF6 tracer technique that measures respired and eructated CH4 However, within the animal, a small proportion of CH4 is produced post‐ruminally and some of this may escape through the rectum. The comparison of emissions using a chamber technique that measures all enteric CH4 losses, and the SF6 tracer technique, could give some insight into the magnitude of post‐ruminal emission. The objective of our study was to assess the precision and accuracy of the SF6 tracer technique against a chamber technique for cattle fed a range of diets. Using a repeated‐measures design, eight beef heifers were offered a high grain or high forage diet for ad libitum or restricted (65% of ad libitum) feed intake to vary the site of digestion within the gastrointestinal tract (n = 24). The SF6 tracer technique underestimated CH4 emissions on average by 4% relative to the chamber technique. This difference was not significant (P > 0.05) and suggests low post‐ruminal CH4 emissions. There was a trend for greater accuracy and precision of the SF6 tracer technique when used with cattle fed a high forage diet at a restricted level of intake. The high forage diet corresponds to the conditions of cattle grazing pasture, suggesting the SF6 tracer technique is most reliable for the grazing system.
Land Application of Carbonatic Lake‐Dredged Materials
Authors: Sigua Gilbert C. , Coleman Samuel W. , Holtkamp Mike L. 
Published: August 2006

ABSTRACTThe ability to reuse carbonatic lake‐dredged materials (CLDM) for agricultural purposes is important because it reduces offshore disposal and provides an alternative to disposal of the materials in landfills that are already overtaxed. A four‐year (2001 to 2005) study on land application of CLDM as an option for disposal was conducted on a beef cattle pasture in south central Florida. The objectives of this study were (i) to assess CLDM as a soil amendment to improve quality of sandy soils in most subtropical beef cattle pastures and (ii) to determine the effect of CLDM on productivity and nutritive values of bahiagrass (BG, Paspalum notatum Flügge) in subtropical beef cattle pasture. The five treatment combinations arranged in randomized complete block design were represented by plots with different ratios (R) of natural soil (NS) to CLDM: R1 (1000 g kg−1:0 g kg−1); R2 (750 g kg−1:250 g kg−1); R3 (500 g kg−1:500 g kg−1); R4 (250 g kg−1:750 g kg−1); and R5 (0 g kg−1:1000 g kg−1). Addition of CLDM had significant (p ≤ 0.001) effects on soil quality and favorable influence on forage establishment and nutritive values. Compared with the control plots (0 g kg−1), the soils in plots amended with CLDM exhibited (i) lower penetration resistance, (ii) an increase in soil pH and exchangeable cations (Ca and Mg), and (iii) decrease in the levels of soil trace metals (Mn, Cu, Fe, Zn, and Si). Results disclosed consistently and significantly (p ≤ 0.001) higher BG biomass production (forage yield = −106.3x2 + 1015.8x − 39.2; R2 = 0.99**) and crude protein content (CP = 1.24x + 6.48; R2 = 0.94**) from plots amended with CLDM than those of BG planted on plots with no CLDM treatment.
QSPR study on pKa values of N-methoxy-polynitroaniline derivatives
Authors: Beteringhe Adrian 
Published: August 2006

Abstract
A QSPR study is presented for acidities of thirteen N-methoxy-polynitroaniline derivatives. Hammett σ values are known for meta and para substituents, and in the present study values are introduced for ortho-substituents in these N-methoxy-polynitroaniline derivatives. Hammett σ values for ortho-substituents in these N-methoxy-polynitroaniline derivatives were obtained by multiplying para values with 0.65.
A convenient synthesis of long-chain 4-substituted benzyloxycarbonyl alkanethiols for the formation of self assembled monolayers on metal substrates
Authors: Angelova Polina , Kostova Kalina , Hinrichs Karsten , Tsankov Dimiter 
Published: August 2006

Abstract
New 4-substituted benzyl esters of 16-mercaptohexadecanoic acid were prepared by developing a practicable synthetic procedure and using readily available staring materials. The compounds synthesized have been characterized by NMR, MS, IR spectra and elemental analysis. The mercapto derivatives are precursors for the formation of self-assembled monolayers on metal substrates.
Laser assisted selective chemical metalization of Al2O3 films
Authors: Krumov Emil , Popov Dimitar , Starbov Nikolay 
Published: August 2006

Abstract
Thick aluminum oxide films are prepared on Al plates by anodizing. On the ceramic surface thus obtained a very thin Ag film is deposited via vacuum thermal evaporation. The Ag/Al2O3/Al samples prepared are irradiated by Nd:YAG laser through a suitable metal mask in order to remove the top metal film in the exposed areas. Thus, a negative silver image of the copied mask is obtained. Further, the samples are processed in Ni electroless chemical bath activated by the rest of silver. All processing steps are studied by scanning electron microscopy (SEM). EDS X-ray mapping is applied to study the final distribution of Al and Ni in the processed areas. In addition, the DC conductivity of the fabricated Ni wires obtained is measured. The proposed new method for selective chemical deposition of electroconductive Ni onto laser microstructured Ag/Al2O3/Al samples is simple, versatile and not restricted to the metal/ceramic system studied as well as to the electroless deposited metal.
Oxidative polymerization of acrylamide in the presence of thioglycolic acid
Authors: Özeroğlu Cemal , Erdoğan Sacide 
Published: August 2006

Abstract
Chemical polymerization of acrylamide at room temperature was examined by using thioglycolic acid-cerium (IV) sulfate and thioglycolic acid-KMnO4 redox systems in acid aqueous medium. Water soluble polyacrylamides containing thioglycolic acid end groups were synthesized. The effects of the molar ratio of acrylamide to Ce(IV) nAAm/nCe(IV), the polymerization time, the temperature, the monomer concentration, the molar ratio of cerium (IV) sulfate to thioglycolic acid and the concentration of sulfuric acid on the yield and molecular weight of polymer were investigated. Lower molar ratios of acrylamide/Ce(IV) at constant monomer concentration resulted in an increase in the yield but a decrease in molecular weight of polymer. The increase of reaction temperature from 20 to 70°C resulted in a decrease in the yield but generally resulted in a constant value for the molecular weight of polymer. With increasing polymerization time, the yield and molecular weight of polymer did not change substantially. Ce(IV) and Mn(VII) ions are reduced to Ce(III) and Mn(II) ions respectively in the polymerization reaction. The existence of Ce(III) ion bound to polymer was investigated by UV-visible spectrophotometry and fluoresce measurements. The amount of Mn(II) incorporated into the polymer was determined using graphite furnace atomic absorption spectrometry. The mechanism of this phenomenon is discussed.
The influence of temperature and photoinitiator concentration on photoinitiated polymerization of diacrylate monomer
Authors: Macarie Lavinia , Ilia Gheorghe 
Published: August 2006

Abstract
The behavior of p-methoxybenzoyldiphenylphosphine oxide, previously synthesized, as a photoinitiator for the polymerization of diacrylate monomer, in the presence of 3% (w/w) tertiary amine (triethyl amine) as synergist additive, was studied. The influence of temperature in the range 30–90°C at 3% (w/w) photoinitiator concentration and the influence of the photoinitiator concentration in the range 0.5–3.5% (w/w) at 30°C was investigated by differential scanning photocalorimetry (photo-DSC). In all experiments the photopolymerization was performed at constant light intensity (3 mW cm−2). The maximum conversion was obtained at temperature of 90°C at 3% (w/w) photoinitiator concentration and 3% (w/w) triethyl amine. The optimal concentration of photoinitiator to obtain maximum conversion was 3% (w/w), at 30°C. No thermal polymerization occurred at higher temperature.
SVD-based principal component analysis of geochemical data
Authors: Praus Petr 
Published: August 2006

Abstract
Principal Component Analysis (PCA) was used for the mapping of geochemical data. A testing data matrix was prepared from the chemical and physical analyses of the coals altered by thermal and oxidation effects. PCA based on Singular Value Decomposition (SVD) of the standardized (centered and scaled by the standard deviation) data matrix revealed three principal components explaining 85.2% of the variance. Combining the scatter and components weights plots with knowledge of the composition of tested samples, the coal samples were divided into seven groups depending on the degree of their oxidation and thermal alteration.
The PCA findings were verified by other multivariate methods. The relationships among geochemical variables were successfully confirmed by Factor Analysis (FA). The data structure was also described by the Average Group dendrogram using Euclidean distance. The found sample clusters were not defined so clearly as in the case of PCA. It can be explained by the PCA filtration of the data noise.
Inclusion-dependent mechanism of modification of cyclodextrins with heterocycles
Authors: Musiol Robert , Girek Tomasz 
Published: August 2006

Abstract
Mono(6-deoxy-dimethylpyridinium)-β-cyclodextrins have been synthesized in reaction of mono (p-toluenesulfonyl) derivative of β cyclodextrin with the appropriate lutidine under microwave irradiation and conventional conditions. The results indicate that the mechanism consists of inclusion complex formation.