bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrate and Chloride in Ground Water Under Irrigated Agriculture in Central Wisconsina
Authors: Saffigna P. G. , Keeney D. R.
Published: July 2006

Results of this study indicate that the nitrate and chloride concentrations in the ground water of the central Wisconsin sand plains are significantly above background, and that the main source is the irrigated agriculture in the region. Nitrate‐N concentrations ranged from nil to 56 mg/1 and chloride from nil to 68 mg/1. Nitrate‐N concentrations exceeded 10 ppm in 15 of 33 irrigation wells and in 2 of 3 domestic wells. Nitrate‐N and chloride concentrations varied widely between adjacent wells but the CI/NO3‐N ratio was much less variable. This suggests similar relative inputs of nitrogen and chloride presumably from nitrogen and potassium (potassium chloride) fertilizers.

The study was conducted at three levels of intensity; a small field during one growing season, a University Experimental Farm over several years, and many local farms during part of a growing season. Differences in concentrations of nitrate‐N and chloride in the surface of the ground water underlying the moderately fertilized potato field closely reflected the fertilizer and irrigation management on different parts of the field during that season. This detailed study of one field showed that solute transit times through the 16 feet (5 m) of unsaturated zone to the surface of the ground water are less than a year.

Differences in concentration of nitrate‐N and chloride between irrigation wells on the Experimental Farm closely reflected the irrigation and fertilizer practices on surrounding fields. Nitrate‐N and chloride concentrations in ground water were lower where the adjacent land had been idle for many years and only recently cropped. However, levels were high where fertilizer and irrigation inputs.

On a larger scale, the nitrate‐N and chloride concentrations in area farmer irrigation wells were as different between wells on the same farm as farm as between the various farms.
Solute Travel Times to Wellsa,b
Authors: Kirkham Don , Affleck S. B.
Published: July 2006

Theoretical travel times are given for a solute to reach a well from an injection point, for wells that fully penetrate confined aquifers of constant thickness and mainly constant conductivity and porosity. Solute is assumed to move along streamlines with the water in piston flow under steady flow conditions. Three cases are considered.

For a “standard” well of external radius of influence re and well radius rw, the travel time varies approximately directly as the square of the distance r of the injection point from the well, as the ratio f/K of porosity to conductivity, and as ln re/rw.

For a well in which the flow region is divided by radius re into two regions, with the region next to the well clogged and of very low conductivity KI the travel time varies approximately directly as r squared, as KI, and as ln rc/rw.

For a well being fed from a line drive (river) at a distance d from the well, the travel time from a point on the line drive to the well varies as the distance d squared, as f/K, as ln 2d/rw, and as a function of the position of the point along the line drive.

In each case, the travel time is inversely proportional to he ‐ hw, where he is the head at the radius of influence re (or at the line drive) and hw is the head at the well. In the three cases, doubling the pumping rate halves the travel time. Travel times can affect the extent of chemical changes of the solute (contaminant) during its flow to the well.
Water Quality at a Sludge Entrenchment Sitea
Authors: Sikora L. J. , Murray C. M. , Frankos N. H. , Walker J. M.
Published: July 2006

Surface‐water and ground‐water quality were evaluated at a site before and for four years after the area was used for entrenchment of sewage sludge. The soils in the area are sandy and are underlain by a clay barrier. Depth of the water table which in most instances is above the clay barrier is from 1.0 to 13.0 m. Water samples taken from monitoring wells, two drainage tiles located along the perimeter of the sludge trenches, a catchment pond and a nearby stream were analyzed for NO3‐N, NH4‐N, and CI. Increases in Cl concentrations were detected in shallow wells within the trench site perimeter 12 months after sludge entrenchment. Chloride levels peaked approximately 18 months after entrenchment and levels declined but not to background levels four years after entrenchment. Nitrate levels increased in shallow wells located within or near the trench site perimeter at 18 months after entrenchment and peaked at 30 months. Decreases in NO3‐N occurred thereafter but had not reached background levels in some wells. Ammonium increases were also detected in wells recording Cl and NO3‐N increases but NH4‐N increases were inconsistent. Increases in Cl and NO3‐N levels were recorded in wells potentially below the trench area, but these levels were less than those recorded for wells within the trench site perimeter. The data from this study indicate that contamination of ground water by leachate from sludge trenches was within the trench site perimeter with a lesser degree of contamination recorded in wells below the trench site. The drainage tiles and clay barrier may have had a significant effect on the resulting ground‐water data, and caution is advised in extrapolating these results to other locations.
Scavenging of Chromium and Cadmium by Aquifer Material — South Farmingdale‐Massapequa Area, Long Island, New Yorka
Authors: Ku Henry F. H. , Katz Brian G. , Sulam Dennis J. , Krulikas Richard K.
Published: July 2006

A plume of ground water enriched by liquid metal‐plating effluent has formed downgradient from an industrial park in southeast Nassau County, New York. Discharges from the plant to the shallow aquifer began in the 1940's and continue to the present.

Core samples of aquifer material from the plume were analyzed by oxalate extraction and dithionite‐citrate‐bicarbonate (DCB) extraction methods for the presence of chromium and cadmium. Results of the extraction indicate that for 1 kilogram of soil, the median concentrations of extracted chromium and cadmium in aquifer material are 7.5 and 1.1 milligrams, respectively, and the maximum concentrations are 19 and 2.3 milligrams, respectively.
Locating Ground Water in the Santa Catherina Area Using Geophysical Methods
Authors: Wachs D. , Arad A. , Olshina A.
Published: July 2006

An attempt was made to locate ground water in an arid, mountainous area in the Santa Catherina region of southern Sinai. A combination of classical geological methods, together with geophysical techniques was found to be particularly useful for the locality studied. It was found that water flow was mainly through the joints of the crystalline basement and that under favorable circumstances, fair ground‐water supplies can be found in alluvial valley fill. It was concluded that recharge of valley fill is derived mainly from the joint system of the bedrock and only partially from flooding.
Sources and Concentrations of Nitrate‐Nitrogen in Ground Water of the Central Platte Region, Nebraskaa
Authors: Gormly J. R. , Spalding R. F.
Published: July 2006

During 1976‐1977 nitrate‐nitrogen (NO3‐N) concentrations exceeded 10 mg/1 in 183 of the 256 ground‐water samples collected from parts of Buffalo, Hall, and Merrick counties in Nebraska. Comparison of the isotopic values with those of potential nitrate sources suggested that the primary source of contamination in most wells was fertilizer and that a small percentage of the wells contained significant concentrations of NO3‐N derived from animal wastes. A combination of two or more sources of contamination was assumed for those samples for which the source could not be identified. Significant negative correlations between δ15N and NO3‐N (‐0.35 in Buffalo and Hall Counties) and between δ5N and depth to water (–0.55 in Merrick County) indicate that denitrification is the major factor in isotopic fractionation of nitrogen from the nitrate sour
THE SOUTH AFRICAN PHILLIPS CURVE: HOW APPLICABLE IS THE GORDON MODEL?
Authors: Burger P. , Marinkov M.
Published: July 2006

Is there a Phillips curve relationship present in South Africa and if so, what form does it take? Traditionally the method to establish whether or not there is a relationship between the output gap and the change in inflation is merely to regress the latter on the former. This yields the well‐known augmented Phillips curve. However, Gordon has argued that this specification of the Phillips curve produces biased results. Instead, he puts forward and estimates successfully for several industrialised countries his so‐called triangular model that tests for hysteresis and inertia in the behaviour of inflation, as well as the impact on inflation of changes in the output level. This paper considers whether or not Gordon's triangle model is applicable to South Africa, i.e. are hysteresis and inertia present in South Africa? In addition, in an attempt to find a better estimation of the output gap, the paper also experiments with alternative ways to estimate the long‐run output level, including the standard HP‐filter, as well as a production function approach.
DURATION ANALYSIS IN SOUTH AFRICA: THE SEARCH FOR SUPERIOR MEASURES
Authors: Van Vuuren Gary , Styger Paul
Published: July 2006

The Macaulay duration is a highly successful tool for measuring and managing interest rate risk. However, it employs restrictive assumptions which constrain its usefulness in a rapidly evolving market. The Basel II implementation and ongoing accounting standard reassessments highlight the requirement for accurate, robust risk measures. Contemporary research has focused on augmenting the existing duration definition. We extend this work by relaxing some input assumptions, describing a different duration measure and applying it to interest rate driven price changes and examining the influence on the duration gap. The economic market value of equity (an important metric for regulators and risk management) is significantly improved.
ON THE OPTIMAL QUANTITY OF PUBLIC GOODS AND RELATED ISSUES
Authors: Agiobenebo Tj
Published: July 2006

This paper seeks to reopen a discussion on what the profession has considered settled and closed, namely the issue of the optimal quantity of a pure public good. We argue that determination of the optimal quantity by the intersection of the collective willingness to pay curve and the supply curve is inappropriate because it exaggerates the aggregate demand for the public good, thus giving rise to misleading supply decisions. The reason lies in the basic properties of pure public goods, in particular that of non‐rival consumption (joint supply). The paper submits that the optimal quantity of a public good is the largest quantity demanded by any single consumer (individually or as a collective). The individual demand curves are required in the analysis only for the purposes of determining the optimal benefit taxes and an equitable cost sharing formula. We show that under such a formula, based on benefit shares, the budget will be balanced, and since the tax burden is smaller than the benefits, less resentment to taxation could be anticipated under this framework.
The Constant Force Component due to Material Separation and Its Contribution to the Size Effect in Specific Cutting Energy
Authors: Subbiah Sathyan , Melkote Shreyes N.
Published: July 2006

The contribution of material separation in cutting ductile metals to the constant force component, and, hence, to the size effect in specific cutting energy is explored in this paper. A force-decomposition-based framework is proposed to reconcile the varied reasons given in literature for the size effect. In this framework, the cutting force is broken down into three components: one that is decreasing, another that is increasing, and the third that remains constant, with decreasing uncut chip thickness. The last component is investigated by performing orthogonal cutting experiments on OFHC copper at high rake angles of up to 70deg in an attempt to isolate it. As the rake angle is increased, the resulting experimental data show a trend toward a constant cutting-force component independent of the uncut chip thickness. Visual evidence of ductile tearing ahead of the tool associated with material separation leading to chip formation is shown. The measured constant force and the force needed for ductile crack extension are then compared.
A Wet Etching Method Coupled With Finite Element Analysis-Based Compliance Function to Determine Residual Stress in High-Speed Milling
Authors: Guo Y. B. , Ammula S. C. , Barkey M. E.
Published: July 2006

High-speed milling (HSM) is widely used in the automotive and aerospace industries in fabricating mechanical components. HSM induced residual stress may significantly impact fatigue life and the corrosion resistance of machined components. Traditional methods of residual stress measurement are very time consuming and expensive. In this paper we presents a wet etching approach to obtain strain as a function of slot depth introduced in the subsurface. The strain readings were collected from a strain gauge mounted on the specimen surface near the slot edge. A compliance function can be conveniently calculated by simulating slot cutting using a finite element method via a Legendre polynomial subroutine as the applied load. The calculated compliance functions and measured strain values at different depths were used as inputs into a program to calculate residual stress. This leads to a faster and less expensive method of determining residual stress when compared with the traditional methods. The capability of this new approach was demonstrated by high-speed milling 6061-T651 and 7050-T7451 aluminum alloys. A design-of-experiment method was used to conduct milling tests with three levels of cutting speed, feed rate, and DOC. Residual stress profiles with 12 data points with the spatial resolution as small as 1μm in the subsurface were then obtained. Residual stress sensitivity to cutting conditions was investigated. In addition, subsurface microstructure and microhardness were also measured to characterize surface integrity in a broad sense.
Response to Comment on "On the Regulation of Populations of Mammals, Birds, Fish, and Insects"
Authors: Sibly Richard M. , Barker Daniel , Denham Michael C. , Hone Jim , Pagel Mark
Published: July 2006

Our conclusions are unaffected by removal of the time series identified by Peacock and Garshelis as harvest data. The relationship between a population's growth rate and its size is generally concave in mammals, irrespective of their body sizes. However, our data set includes quality data for only five mammals larger than 20 kilograms, so strong conclusions cannot be made about these animals.
Coronary-pulmonary artery fistula diagnosed by multidetector computed tomography
Authors: Zeina A-R , Blinder J , Rosenschein U , Barmeir E
Published: July 2006

Coronary-pulmonary artery fistula is an uncommon cardiac anomaly, usually congenital. Most coronary-pulmonary artery fistulas are clinically and haemodynamically insignificant and are usually found incidentally. This report describes a case of complex coronary-pulmonary artery fistula with two feeding vessels of separate origins: one from the proximal part of the left anterior descending artery and another arising from the right aortic cusp. The complex anatomy of the fistula was shown in detail by multidetector computed tomography using multiplanar reconstruction and 3D volume rendering techniques.
Learning-Induced Reversal of the Effect of Noradrenalin on the Postburst AHP
Authors: Brosh Inbar , Rosenblum Kobi , Barkai Edi
Published: July 2006

Pyramidal neurons in the piriform cortex from olfactory-discrimination–trained rats have reduced postburst afterhyperpolarization (AHP), for 3 days after learning, and are thus more excitable during this period. Such AHP reduction is caused by decreased conductance of one or more of the calcium-dependent potassium currents, IAHPand s IAHP, that mediate the medium and slow AHPs. In this study, we examined which potassium current is reduced by learning and how the effect of noradrenalin (NE) on neuronal excitability is modified by such reduction. The small conductance (SK) channels inhibitor, apamin, that selectively blocks IAHP, reduced the AHP in neurons from trained, naïve, and pseudotrained rats to a similar extent, thus maintaining the difference in AHP amplitude between neurons from trained rats and controls. In addition, the protein expression level of the SK1, SK2, and SK3 channels was also similar in all groups. NE, which was shown to enhance IAHPwhile suppressingSIAHP, reduced the AHP in neurons from controls but enhanced the AHP in neurons from trained rats. Our data show that learning-induced enhancement of neuronal excitability is not the result of reduction in the IAHPcurrent. Thus it is probably mediated by reduction in conductance of the other calcium-dependent potassium current, s IAHP. Consequently, the effect of NE on neuronal excitability is reversed. We propose that the change in the effect of NE after learning may act to counterbalance learning-induced hyperexcitability and preserve the piriform cortex ability to subserve olfactory learning.
Janus Kinase 2: A Critical Target in Chronic Myelogenous Leukemia
Authors: Samanta Ajoy K. , Lin Hui , Sun Tong , Kantarjian Hagop , Arlinghaus Ralph B.
Published: July 2006

The Bcr-Abl tyrosine kinase is the causative factor in most chronic myelogenous leukemia (CML) patients. We have shown that Bcr-Abl is associated with a cluster of signaling proteins, including Janus kinase (Jak) 2, growth factor receptor binding protein 2–associated binder (Gab) 2, Akt, and glycogen synthase kinase (GSK)-3β. Treatment of CML cell lines and mouse Bcr-Abl+ 32D cells with either Jak2 short interfering RNA or Jak2 kinase inhibitor AG490 inhibited pTyr Gab2 and pSer Akt formation, inhibited the activation of nuclear factor-κB, and caused the activation of GSK-3β, leading to the reduction of c-Myc. Importantly, BaF3 cells expressing T315I and E255K imatinib-resistant mutants of Bcr-Abl underwent apoptosis on exposure to AG490 yet were resistant to imatinib. Similar to wild-type Bcr-Abl+ cells, inhibition of Jak2 by Ag490 treatment resulted in decrease of pSer Akt and c-Myc in imatinib-resistant cells. These results identify Jak2 as a potentially important therapeutic target for CML. (Cancer Res 2006; 66(13): 6468-72)
Valproic Acid–Induced Gene Expression through Production of Reactive Oxygen Species
Authors: Kawai Yumiko , Arinze Ifeanyi J.
Published: July 2006

Valproic acid (VPA) is a widely used anticonvulsive agent that has profound antiproliferative effects in many cell types, as well as inductive effects on a number of genes. The mechanism of its gene-inducing effect has been reported to involve transcription factors, Sp1 and activator protein-1. Using two well-characterized antioxidant response element (ARE)–driven gene promoters, i.e., mouse heme oxygenase-1 and human NAD(P)H:quinone oxidoreductase 1 genes as tools to monitor the transcriptional response to VPA, we show here that VPA-induced gene transcription was abrogated by antioxidants. With the human Gαi2 gene promoter, which was previously used to establish the involvement of Sp1 in the transcriptional action of VPA, we found that VPA-induced gene transcription was also blocked by antioxidants. Mutation of the ARE (5′-TGACtggGC-3′) in this promoter abrogated the transcriptional response to VPA. With such mutants, the NADPH oxidase inhibitor, diphenyleneiodonium, had no effect on VPA-induced transcription. In gel mobility shift assays, VPA-induced binding of nuclear proteins to a DNA probe containing the relevant ARE sequence in the Gαi2 gene promoter was decreased in nuclear extracts from cells pretreated with antioxidants. Chromatin immunoprecipitation assays showed that the prototype redox-sensitive transcription factors, Nrf2, small Maf protein(s), and c-Fos, were recruited to this promoter in VPA-treated cells. Overall, this study reveals that the mechanism of the transcriptional response to VPA includes VPA-induced production of reactive oxygen species which induce the activation of redox-sensitive transcription factors that interact with the ARE. (Cancer Res 2006; 66(13): 6563-9)
Of Electrum and the Armour of Achilles: Myth and Magic in a Manuscript of Heinrich Khunrath (1560-1605) Zusammenfassung
Authors: Tilton Hereward
Published: July 2006

Das Manuskript des Alchemisten und Theosophen Heinrich Khunrath (1560-1605), gerichtet an den Verteidiger der Interessen schwedischer Protestanten, Herzog Karl, beschreibt eine Methode zur Herstellung einer magischen Rüstung und bietet einen Einblick in die praktische Anwendung magischer Konzepte in der Tradition Ficinos, Agrippas, Paracelsus' und Della Portas. Die vorliegende Studie beschreibt detailliert Khunraths Anwendung einer pseudo-paracelsischen magischen Legierung, ebenso wie seine Rezeption der Beschreibungen der magischen Waffen Achills bei Homer und Vergil. Es wird gezeigt, daß Khunraths magische Rüstung gemäß der Ficinischen Prinzipien der “fascinatio” (Behexung) und der Einführung himmlischer Kräfte in Dinge durch die imaginative Kraft des Magus wirkt. Diese Prinzipien werden auf dem Hintergrund der neuplatonischen Kosmologie Khunraths erörtert. Die Frage der Beziehung der euhemeristischen Interpretation des antiken Mythos in diesem Manuskript zum vorherrschend allegorischen Genre der Mythoalchemie wird ebenso behandelt, wie andere Versuche, magische Überlegenheit und Unverletzbarkeit in der Kriegsführung des frühneuzeitlichen Europa zu gewinnen, angesprochen werden.
Root-Water-Uptake Based upon a New Water Stress Reduction and an Asymptotic Root Distribution Function
Authors: Li K. Y. , De Jong R. , Coe M. T. , Ramankutty N.
Published: July 2006

A water stress–compensating root-water-uptake module was developed based upon a newly proposed water stress reduction function and an asymptotic root distribution function. The water stress reduction function takes into account both soil water pressure head and soil resistance to water flow. It requires only physically based parameters that eliminate the need for empirical calibration. The root-water-uptake module, incorporated into a complete Soil–Vegetation–Atmosphere Transfer (SVAT) simulation model, was tested for a variety of soil, crop, and climatic conditions across Canada. Both the proposed water stress reduction and the asymptotic root distribution function performed similarly to existing ones, with the maximum difference in normalized root-mean-square error (NRMSE) between the new and existing water stress reduction function being 0.6%, and between the asymptotic and an exponential root distribution function being 1.2%. The entire root-water-uptake module worked as well as, or better than, published ones. Because the new module uses fewer empirical parameters, it becomes particularly useful in large-scale modeling applications of land surface, hydrology, and terrestrial ecosystems where such parameters are usually not readily available.
Changes in Instruments and Sites Affecting Historical Weather Records: A Case Study
Authors: Changnon Stanley A. , Kunkel Kenneth E.
Published: July 2006

All long historical climate records are based on measurements that experienced shifts in instrumentation, site characteristics, or locations. How such changes affect the quality of past data remains an uncertainty for the thousands of historical records, confounding efforts to assess climate change. Fortunately, one station in Illinois with 118 yr of records has also kept detailed records of all such shifts plus overlapping measurements of temperatures and precipitation, allowing exact measurements of how conditions changed over time. This study examined these data and found varying discontinuities of 0.1°–0.9°C in annual temperatures due to various shifts, but no changes in daily precipitation related to site shifts. However, hourly precipitation amounts from recording rain gauges did undergo a considerable shift due to changes in rain gauge types. Similar studies need to be made of other stations with comparable historical records of station and instrument shifts and with overlapping measurements when shifts were made.
The Control of Living Anionic Polymerization by Metalloporphyrins
Authors: Sugimoto Hiroshi , Aida Takuzo , Inoue Shohei
Published: July 2006

The living polymerization of methacrylic esters initiated with aluminium porphyrins was found to be dramatically accelerated upon the addition of organoaluminium or organoboron compounds as a Lewis acidic monomer activator (high-speed living polymerization). Under appropriate conditions, high-molecular-weight poly(methyl methacrylates) (Mn > 500000) having a narrow molecular-weight distribution (Mw/Mn = 1.1—1.2) were synthesized. The key concept of the high-speed living polymerization is the coexistence of nucleophilic growing species and a Lewis acid without a degradative direct reaction.
Regio- and Stereoselective Synthesis of 1,5-Dienes Using Allylic Barium Reagents
Authors: Yanagisawa Akira , Hibino Hiroaki , Habaue Shigeki , Hisada Yoshiyuki , Yasue Katsutaka , Yamamoto Hisashi
Published: July 2006

The highly α,α′ selective and stereocontrolled homocoupling reaction of allylic halides was achieved using barium reagent. The double-bond geometry of the starting allylic chloride was completely retained. The α,α′ cross-coupling products were also prepared stereospecifically and regioselectively by this method.
Solvent-Induced Vibrational Relaxation in Benzaldehyde
Authors: Bhattacharjee Debajyoti , Ghosh (Purkayastha) Anusree , Misra T N
Published: July 2006

The Raman band of the C=O stretching vibration of benzaldehyde has been recorded as a function of the concentration in a number of solvents. The experimental results suggest that dispersion forces are responsible for the observed frequency shift. The variation in the band-shape parameters have been interpreted using microviscosity theory.
Crystal Structures of Two Isomeric Series of Mesogens, 4-Cyanophenyl 4-n-Alkoxybenzoates and 4-n-Alkoxyphenyl 4-Cyanobenzoates
Authors: Iki Hitoe , Hori Kayako
Published: July 2006

Single crystal X-ray analysis has been done for two isomeric series, 4-cyanophenyl 4-n-alkoxybenzoates (CPnOB, n = 6, 7, and 8) with a phase sequence of crystal–nematic–isotropic and 4-n-alkoxyphenyl 4-cyanobenzoates (nOPCB, n = 6, 7, and 8), which have the smectic A phase as well as the nematic phase for n = 7 and 8. In the crystals of CP6OB and CP8OB, close arrangements between CN groups of a pair of molecules are observed, though in the latter crystal two carbonyloxy groups between another pair of molecules are also closely arranged. For CP7OB and 6OPCB, CN and carbonyloxy groups come close to each other between a pair of molecules. These pairs of molecules have half-and-half overlappings (imbricate structures), being closely related to the nematic structure. On the other hand, the crystal of 7OPCB has a distinct smectic-like layer structure with infinite networks of close arrangement of the CN groups, while in the crystal of 8OPCB dimers formed by association of the CN and carbonyloxy groups are arranged in an alternate stacking of core moieties and chains, also closely related to a smectic-like layer structure. The different features of the two series are discussed in terms of the different magnitudes of the overall dipole moments along the molecular long axes caused by opposite directions of the carbonyloxy groups between the two series.
Transfer of 2-Aminoethanethiolate (aet) from Nickel(II) to Cobalt(III) Coordination Sphere. Synthesis, Crystal Structure, and Some Properties of an S-Bridged Trinuclear Complex [Ni{Co(aet)2(en)}2]4+
Authors: Konno Takumi , Hidaka Jinsai , Okamoto Ken-ichi
Published: July 2006

The reaction of [CoCl2(en)2]+ with [Ni(aet)2] in water gave an S-bridged CoIIINiIICoIII trinuclear complex, [Ni{Co(aet)2(en)}2]4+ (1), which indicates that the bidentate-N,S ligand aet transfers from the NiII to the CoIII coordination sphere. 1 formed only the racemic compound of Δ(C2-cis(S))Δ(C2-cis(S)) and Λ(C2-cis(S))Λ(C2-cis(S)) isomers, and its crystal structure was analyzed by X-ray diffraction. [Ni{Co(aet)2(en)}2]Cl4·6H2O, chemical formula C12H52N8O6S4Cl4Co2Ni, crystallizes in the monoclinic space group C2/c with a = 14.987(4), b = 19.480(3), c = 12.916(4) Å, β = 113.67(1)°, V = 3454(1) Å3, Z = 4, and R = 0.046. The central NiII atom is situated in an environment markedly distorted from a square-planar to a tetrahedral geometry, coordinated by four thiolato sulfur atoms from two octahedral C2-cis(S)-[Co(aet)2(en)]+ units. The H2O2 oxidation of 1 caused the cleavage of the Ni–S bonds to afford the mononuclear sulfinato complex, [Co(NH2CH2CH2SO2-N,S)2(en)]+ (2), retaining the C2-cis(S) geometry of 1. 1 and 2 were optically resolved and their absorption, CD, and NMR spectral behavior are reported.
N-Nitroso-N-(n-butoxymethyl)arylamines
Authors: Verardo Giancarlo , Giumanini Angelo G , Gorassini Fausto , Strazzolini Paolo
Published: July 2006

The title compounds were promptly obtained in fair to good yields as distillable liquids by admixing 1,3,5-triarylhexahydro-1,3,5-triazines (1) with n-butyl nitrite (2) in anhydrous CH2Cl2 and were fully characterized by 1H and 13C NMR, IR, and MS. The pure products were invariably made up of geometric isomers which did not interconvert rapidly at room temperature. o-Substituents could cause difficulties in the free rotations of the aryl substituent about the C–N bond as well of the α-butoxymethyl group. The reaction is believed to occur on the monomeric imines derived from the thermal equilibration of their trimeric and dimeric precursors. Aliphatic hexahydrotriazines were found to be unreactive under the present conditions.
Dehydrooligopeptides. XVII. Practical Syntheses of All of the Diastereomers of N,N-Protected 2,3-Diaminobutanoic Acids from l- and d-Threonine Derivatives
Authors: Nakamura Yutaka , Hirai Miki , Tamotsu Kenji , Yonezawa Yasuchika , Shin Chung-gi
Published: July 2006

Syntheses of all of the diastereomers of 2,3-diaminobutanoic acids, found in some peptide antibiotics and toxins, were accomplished. The four isomers were derived mainly through two pathways including SN2 inversions of the β-substituent of l- or d-threonine derivatives. The various protecting groups and effective nucleophiles for the SN2 inversion were examined.
Mexican Contract Workers and the U.S. Capitalist Agricultural Labor Process: The Formative Era, 1942–1964*
Authors: Mize Ronald L.
Published: July 2006

Abstract  Rural sociologists have seemingly moved away from an active interest in the plight of migrant farmworkers and the centrality of their labor in the development of U.S. agribusiness. Answering Pfeffer's (1983) call to analyze the different forms of agricultural production, I focus on the key formative period of what I refer to as the U.S. capitalist agricultural labor process. During the United States‐Mexico Bracero Program, 1942–1964, U.S. agribusiness employed a coercive factory regime, introduced mechanization and increased work hazards, and employed a dual wage structure to keep Mexican contract workers at a serious disadvantage to advance their own collective well‐being. This study relies upon archival and oral history research to challenge the existing theoretical approaches to the labor process in capitalist agriculture and provide a theoretical explanation that more closely relates to U.S. post‐war agricultural production.
Air Pollution and Very Low Birth Weight Infants: A Target Population?
Authors: Rogers J. Felix , Dunlop Anne L.
Published: July 2006

OBJECTIVE. The goal was to examine systematically the association between maternal exposure to particulate matter of <10 μm and very low birth weight (<1500 g) delivery for evidence of an effect on duration of gestation and/or intrauterine growth restriction.

METHODS. This case-control study took place between April 1, 1986, and March 30, 1988, in Georgia Health Care District 9 and included 128 mothers of very low birth weight infants, all of whom were preterm and were classified as either small for gestational age or appropriate for gestational age, and 197 mothers of term, appropriate-for-gestational-age infants weighing ≥2500 g. Maternal exposure to particulate matter of <10 μm was estimated with 2 exposure measures, namely, a county-level measure based on residence in a county with an industrial point source and an environmental transport model based on the geographic location of the birth home.

RESULTS. Considering preterm/appropriate-for-gestational-age infants as cases and term/appropriate-for-gestational-age infants as controls, adjusted odds ratios for maternal exposure to particulate matter of <10 μm were statistically significant (adjusted odds ratio for county-level model: 4.31; adjusted odds ratio for environmental transport model: 3.68). Although elevated, no statistically significant association was found between maternal exposure and preterm/appropriate-for-gestational-age delivery when compared to preterm/small-for-gestational-age delivery.

CONCLUSIONS. There are increased odds of maternal exposure to ambient particulate matter of <10 μm for very low birth weight preterm/appropriate-for-gestational-age delivery, compared with term/appropriate-for-gestational-age delivery, which suggests that the observed association between maternal exposure to air pollution and low infant birth weight (particularly <1500 g) is at least partially attributable to an effect on duration of gestation.
Protecting Low-Income Children's Access to Care: Are Physician Visits Associated With Reduced Patient Dropout From Medicaid and the Children's Health Insurance Program?
Authors: Sommers Benjamin D.
Published: July 2006

OBJECTIVE. Dropout among patients who are enrolled in Medicaid and the Children's Health Insurance Program contributes to a lack of health care access among millions of Americans. The purpose of this study was to determine which, if any, types of clinical contact with physicians are associated with reduced dropout among children who are enrolled in Medicaid and the Children's Health Insurance Program.

METHODS. The data are from the nationally representative Medical Expenditure Panel Survey, 1998–2002. The sample is composed of all children (n = 3043) who were reported to have Medicaid or Children's Health Insurance Program coverage throughout their first year in the survey and who did not acquire other insurance during the study period. The outcome measure is whether an individual remained enrolled in Medicaid or the Children's Health Insurance Program by the end of the following year. Exposure variables were clinical contact during an individual's first year in the survey: numbers of office visits, hospital outpatient department visits, emergency department visits, inpatient hospital stays, and dental visits. The analysis uses multivariate logistic regression to control for patient and family characteristics—most important, health status, functional status, and overall health care expenditures.

RESULTS. Eight percent of the children in the sample had left Medicaid/the Children's Health Insurance Program by the end of the second year in the survey. More frequent contact with clinicians in an office setting was associated with a significantly lower risk for dropping out of Medicaid/the Children's Health Insurance Program among children, even controlling for demographics, health and functional status, and overall health care expenditures. After multivariate adjustment, more frequent contact in hospital outpatient departments also was associated with reduced dropout, with a borderline statistically significant odds ratio. Notably, emergency visits and inpatient stays were not associated with any significant change in the risk of Medicaid/Children's Health Insurance Program dropout.

CONCLUSIONS. These results suggest that some but not all types of clinician visits are serving an important function in maintaining Medicaid and the Children's Health Insurance Program coverage among low-income patients. Two possible approaches to improve access to care among low-income children therefore would be (1) increased awareness among clinicians, especially in hospitals and emergency departments, regarding Medicaid/Children's Health Insurance Program retention as an issue in the ongoing care of their patients and (2) Medicaid/Children's Health Insurance Program reimbursement of clinicians and their staff for assisting patients with the public insurance renewal process.
Impact of Postpartum Hospital-Stay Legislation on Newborn Length of Stay, Readmission, and Mortality in California
Authors: Datar Ashlesha , Sood Neeraj
Published: July 2006

OBJECTIVES. The objectives of this study were to examine the impact of postpartum hospital-stay legislation on newborns’ length of stay, neonatal readmissions, and 1-year mortality in California, and whether this legislation had differential impacts by demographics and complications during delivery or pregnancy.

METHODOLOGY. This study used linked birth certificates, death certificates and hospital discharge records for all full-term, normal birth weight, and singleton-birth newborns during 1991–2000 in California (n = 662 753). Interrupted time-series analyses were used to examine changes in newborns’ length of stay and outcomes after 1 year, 2 years, and 3 years since the passage of postpartum laws. Multivariate linear and logistic regressions were estimated separately by maternal characteristics (race, education, age, and partity), delivery type, and complications during pregnancy or delivery.

RESULTS. Length of stay increased by 9.5, 12, and 14 hours in years 1, 2, and 3, respectively, after the passage of the law. Increases were larger for newborns of white mothers, more educated mothers, mothers >35 years of age, primaparous mothers, cesarean deliveries, and Medicaid recipients, but there were no differences by pregnancy or delivery complications. The odds of neonatal readmission declined by 9.3%, 11.8%, and 19.7% in years 1, 2 and 3 after the law, respectively. The odds of infection-related readmissions declined by 21.5% and 30.3% in years 2 and 3, respectively. The odds of jaundice-related readmissions increased by 7% in year 1. There was no significant change in either the odds of readmission due to respiratory problems or the odds of 1-year mortality in the postlaw years. Demographic differences in the impact of the law on readmissions and mortality could not be detected because of lack of statistical power.

CONCLUSIONS. Postpartum length of stay legislation was associated with increased length of stay among all births in California, with significant variation in the law’s impact across demographic groups. After the law’s passage, there was a significant decline in neonatal readmissions but not in 1-year mortality.
Safety of reduced-dosage ketoprofen for long-term oral administration in healthy dogs
Authors: Narita Tatsuya , Sato Reeko , Tomizawa Nobuyuki , Tani Kenji , Komori Shinobu , Hara Shigeo
Published: July 2006

Objective—To evaluate the safety of reduced-dosage ketoprofen (RDKET) for long-term oral administration in healthy dogs.

Animals—14 healthy Beagles.

Procedures—Racemic ketoprofen (0.25 mg/kg, PO) and gelatin capsules, as a drug-free placebo, were each administered to 7 dogs for 30 days. Dogs were periodically monitored via physical examination, blood analyses, endoscopic examinations, fecal occult blood tests (tetramethylbenzidine and guaiac methods), renal function tests (effective renal plasma flow and glomerular filtration rate), urinalyses, urinary enzyme indices (N-acetyl-β-D-glucosaminidase and γ-glutamyl-transferase), and hemostatic function tests (buccal mucosa bleeding time, cuticle bleeding time, prothrombin time, activated partial thromboplastin time, and fibrinogen concentration).

Results—Pyloric antrum lesion grade was significantly higher in the RDKET group on day 28, compared with the pretreatment and control group grades. Fecal occult blood grade measured by use of the tetramethylbenzidine method was significantly higher in the RDKET group on day 30, compared with the pretreatment grade. No other significant differences were detected between treatment groups.

Conclusions and Clinical Relevance—RDKET induced mild to moderate gastric mucosal injuries especially in the pyloric antrum in healthy Beagles, whereas no adverse effects were observed in renal function or hemostasis. Fecal occult blood tests may be useful as screening tests for adverse gastrointestinal effects induced by RDKET in dogs.
Use of end-tidal partial pressure of carbon dioxide to predict arterial partial pressure of carbon dioxide in harp seals during isoflurane-induced anesthesia
Authors: Pang Daniel S. J. , Rondenay Yves , Troncy Eric , Measures Lena N. , Lair Stéphane
Published: July 2006

Objective—To evaluate the relationship between end-tidal partial pressure of CO2 (ETCO2) and PaCO2 in isoflurane-anesthetized harp seals.

Animals—Three 5-month-old 25- to 47-kg harp seals (Phoca groenlandica).

Procedures—PaCO2 was determined in serial arterial samples from isoflurane-anesthetized seals and compared with concomitant ETCO2 measured with a side-stream microstream capnograph. Twenty-four paired samples were subjected to linear regression analysis and the Bland-Altman method for assessment of clinical suitability of the 2 methods (ie, PaCO2 and ETCO2 determinations). The influence of ventilation rate per minute (VR) on the ETCO2 to PaCO2 difference (P[ET-a] CO2) was examined graphically.

Results—The correlation coefficient between the 2 measurements was 0.94. The level of agreement between ETCO2 and PaCO2 varied considerably. Values of ETCO2 obtained with a VR of < 5 underestimated PaCO2 to a greater degree (mean bias, −4.01 mm Hg) and had wider limits of agreement of −13.10 to 5.07 mm Hg (−4.01 mm Hg ± 1.96 SD), compared with a VR of ≥ 5 (mean bias, −2.24 mm Hg; limits of agreement, −7.79 to 3.30 mm Hg).

Conclusions and Clinical Relevance—These results indicate that a microstream sidestream capnograph provides a noninvasive, sufficiently accurate estimation of PaCO2 with intermittent positive ventilation at a VR ≥ 5 in anesthetized harp seals.
Assessment of antimicrobial transfer from treated to untreated mammary gland quarters by use of high-pressure liquid chromatography for detection of cloxacillin in milk samples from nonlactating dairy cows
Authors: Sanford Carolyn J. , Keefe Greg P. , Dohoo Ian R. , Leslie Ken E.
Published: July 2006

Objective—To determine whether half-udder intramammary infusion of cloxacillin results in transfer of cloxacillin from treated to untreated mammary gland quarters within nonlactating cows, and, if so, at what concentrations, and to determine whether selection of ipsilateral versus diagonal-contralateral quarters for treatment affects cloxacillin transfer among quarters.

Animals—20 Holstein-Friesian cows from a dairy herd.

Procedures—A within-cow half-udder comparison trial was used in which 2 of 4 mammary gland quarters (ipsilaterally or diagonally) received an intramammary infusion of cloxacillin on day 1 of the nonlactating period. Three days later, milk samples were taken from all untreated quarters and high-pressure liquid chromatography was used to detect and quantify milk cloxacillin concentrations.

Results—Cloxacillin was detected in 25% of all untreated mammary gland quarters. Mean cloxacillin concentration in untreated quarters was below minimum inhibitory concentrations for targeted mastitis pathogens. No significant difference in cloxacillin concentrations was found in the ipsilateral or diagonal treatment groups.

Conclusions and Clinical Relevance—Within-cow half-udder comparison trials are valid for antimicrobial trials in nonlactating cows, although transfer of antimicrobials does occur in trace concentrations. Ipsilateral or diagonal-contralateral treatment designs perform similarly. This type of design is economical for researchers, although care must be taken to account for within-cow clustering of mammary gland quarter data.
Comparison of the biological activity of recombinant human thyroid-stimulating hormone with bovine thyroid-stimulating hormone and evaluation of recombinant human thyroid-stimulating hormone in healthy dogs of different breeds
Authors: Boretti Felicitas S. , Sieber-Ruckstuhl Nadja S. , Willi Barbara , Lutz Hans , Hofmann-Lehmann Regina , Reusch Claudia E.
Published: July 2006

Objective—To evaluate whether use of recombinant human (rh) thyroid-stimulating hormone (TSH) induces equivalent stimulation, compared with bovine TSH (bTSH), and to evaluate activity of rhTSH in dogs of various large breeds.

Animals—18 healthy research Beagles and 20 healthy client-owned dogs of various breeds with body weight > 20 kg.

Procedures—The 18 Beagles were randomly assigned to 3 groups, and each dog received either 75 μg of rhTSH, IM or IV, or 1 unit of bTSH, IM, respectively, in a crossover design. The 20 client-owned dogs received 75 μg of rhTSH, IV. Blood samples were taken before and 6 hours after TSH administration for determination of total serum thyroxine (T4) concentration. Additional blood samples were taken after 2 and 4 hours in Beagles that received rhTSH, IM.

Results—There was a significant increase in T4 concentration in all dogs, but there were no differences between values obtained after administration of bTSH versus rhTSH or IV versus IM administration of rhTSH. Although there was a significant difference in age and body weight between Beagles and non-Beagles, there was no difference in post-TSH simulation T4 concentration between the 2 groups.

Conclusions and Clinical Relevance—Results indicated an equivalent biological activity of rhTSH, compared with bTSH. Use of 75 μg of rhTSH, IV, did not induce a different magnitude of stimulation in large-breed dogs, compared with Beagles. Euthyroidism was confirmed if post-TSH simulation T4 concentration was ≥ 2.5 μg/dL and at least 1.5 times basal T4 concentration.
Arresting, Fixing, and Separating Dimers Composed of Uniform Silica Colloidal Spheres
Authors: Ibisate M. , Zou Z. , Xia Y.
Published: July 2006

When fresh tetraethylorthosilicate is introduced into a colloidal suspension of silica spheres, it hydrolyzes and condenses in situ to arrest and fix the dimers resulting from constant collisions between the spheres. By optimizing the experimental parameters (including the length of aging time) and the diameter of the silica spheres, as well as the concentrations of counterions, water, and ammonia, it is possible to routinely produce monodisperse dimers with a yield as high as 50 %. When combined with centrifugation using a density gradient medium, the yield of such dimers could be further increased to 80 %. It is believed that this method will provide a simple and versatile approach to the high‐volume production of dimers from spherical colloids composed of different materials. These dimers may find widespread use in a range of applications such as fabrication of photonic crystals and fundamental studies related to colloidal science.