bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Shape of the Michigan River as Viewed from the Land of Sweatt v. Painter and Hopwood
Authors: Russell Thomas D. 
Published: July 2006

If general ideas and theories about what's going on in society are going to be anything other than moonshine, they have to be rooted in hard-bought knowledge of what in fact is happening in people's lives.
—J. Willard Hurst (1910-96)

There are 5 African Americans among the 433 students in The University of Texas School of Law's class of 2000. There are 7 in the class of 2001, and 7 in the class of 2002. With 1,387 students, the UT School of Law is big. The 19 African American students comprise 1.4% of the total.
Production of indole diterpenes by Aspergillus alliaceus
Authors: Junker B. , Walker A. , Connors N. , Seeley A. , Masurekar P. , Hesse M. 
Published: July 2006

AbstractProduction of two related indole diterpenes (differing by a dimethyl leucine side chain) by Aspergillus alliaceus was improved through several pilot scale fermentations. Media were optimized through focus primarily on initial increases, as well as mid‐cycle additions, of carbon and nitrogen sources. Fermentation conditions were improved by varying ventilation conditions using various combinations of air flowrate and back‐pressure set points. Production improvements were quantified based on total indole diterpene concentration as well as the ratio of the major‐to‐minor by‐product components. Those changes with a positive substantial impact primarily on total indole diterpene concentration included early cycle glycerol shots and enhanced ventilation conditions (high air flowrate, low back‐pressure). Those changes with a significant impact primarily on ratio included higher initial cerelose, soybean oil, monosodium glutamate, tryptophan, or ammonium sulfate concentrations, higher broth pH, and enhanced ventilation conditions. A few changes (higher initial glycerol and monosodium glutamate concentrations) resulted in less notable and desirable titer or ratio changes when implemented individually, but they were adopted to more fully realize the impact of other improvements or to simplify processing. Overall, total indole diterpene titers were improved at the 600 L pilot scale from 125–175 mg/L with a ratio of about 2.1 to 200–260 mg/L with a ratio of about 3.3–4.5. Thus, the ability to optimize total indole diterpene titer and/or ratio readily exists for secondary metabolite production using Aspergillus cultures. © 2006 Wiley Periodicals, Inc.
Isotopomer analysis of myocardial substrate metabolism: A systems biology approach
Authors: Vo Thuy D. , Palsson Bernhard O. 
Published: July 2006

AbstractThe increasing accessibility of mass isotopomer data via GC‐MS and NMR technology has necessitated the use of a systematic and reliable method to take advantage of such data for flux analysis. Here we applied a nonlinear, optimization‐based method to study substrate metabolism in cardiomyocytes using 13C data from perfused mouse hearts. The myocardial metabolic network used in this study accounts for 257 reactions and 240 metabolites, which are further compartmentalized into extracellular space, cytosol, and mitochondrial matrix. Analysis of the perfused mouse heart showed that the steady‐state ATP production rate was 16.6 ± 2.3 µmol/min · gww, with 30% of the ATP coming from glycolysis. Of the four substrates available in the perfusate (glucose, pyruvate, lactate, and oleate), exogenous glucose forms the majority of cytosolic pyruvate. Pyruvate decaboxylation is significantly higher than carboxylation, suggesting that anaplerosis is low in the perfused heart. Exchange fluxes were predicted to be high for reversible enzymes in the citric acid cycle (CAC), but low in the glycolytic pathway. Pseudoketogenesis amounted to approximately 50% of the net ketone body uptake. Sensitivity analysis showed that the estimated flux distributions were relatively insensitive to experimental errors. The application of isotopomer data drastically improved the estimation of reaction fluxes compared to results computed with respect to reaction stoichiometry alone. Further study of 12 commonly used 13C glucose mixtures showed that the mixtures of 20% [U‐13C6] glucose, 80% [3 13C] glucose and 20% [U‐13C6] glucose, 80% [4 13C] were best for resolving fluxes in the current network. © 2006 Wiley Periodicals, Inc.
Weak noncovalent Si···FC interactions stabilized fluoroalkylated rod‐like polysilanes as ultrasensitive chemosensors
Authors: Saxena Anubhav , Rai Roopali , Kim Sun‐Young , Fujiki Michiya , Naito Masanobu , Okoshi Kento , Kwak Giseop 
Published: July 2006

AbstractNoncovalent interactions, such as hydrogen bonding, metal coordination, and π‐π stacking, are increasingly being utilized to develop well‐ordered and self‐organized supramolecular materials. Recently, new types of nonclassical weak interactions, such as CH···π, CH···FC, and CH···O, have been exploited in stabilizing the specific conformations of molecules and molecular assemblies in the solid state. These noncovalent interactions play an important role in materials comprised of polymer chains, because cooperative effects from a large number of weak interactions can lead to drastic changes in its conformation, several properties, and functionalities. The programmed design of synthetic helical polymer with well‐defined molecular conformation has been the main subject in modern polymer science and engineering. Silicon‐catenated polysilane is an ideal helical silicon quantum wire and polymers with unique photophysical properties. The present review highlights the spectroscopic evidences for through‐space weak Si···FC interaction in poly(methyl‐3,3,3‐trifluoropropylsilane) (1) in noncoordinating and coordinating solvents by means of NMR (29Si and 19F) and IR spectroscopies, and viscometric measurement. It was found that 1 is applicable for chemosensors with an extremely high sensitivity and selectivity toward fluoride ions in tetrahydrofuran (THF) and with high sensitivity for nitroaromatic compounds, detected by a decrease in the photoluminescence intensity in THF and in thin solid film. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5060–5075, 2006
Environmentally benign atom transfer radical polymerization: Towards “green” processes and materials
Authors: Tsarevsky Nicolay V. , Matyjaszewski Krzysztof 
Published: July 2006

AbstractAtom transfer radical polymerization (ATRP) is a metal complex‐catalyzed method of controlled radical polymerization that has been successfully employed to prepare a multitude of well‐defined functional polymeric materials. The environmental aspects of ATRP that are reviewed in this work include (i) methods for catalyst removal and its potential further recycling, (ii) development of active ATRP catalysts that can be used at low concentration, (iii) conducting ATRP in environmentally friendly media (water, supercritical carbon dioxide, and ionic liquids), and (iv) application of ATRP to the production of advanced materials such as self‐plasticized poly(vinyl chloride) and (bio)degradable polymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5098–5112, 2006
Capturing urban student voices in the creation of a science mini‐documentary
Authors: Furman Melina , Barton Angela Calabrese 
Published: July 2006

AbstractIt has been widely proposed that student voices should play a crucial role in designing and implementing curriculum and instruction that promote students' engagement in science learning. In this study we examined the voices of two seventh grade boys from a low‐income urban community as they worked together in an after‐school program to create a student‐directed video documentary about science. Our analysis showed that these students used their voices to construct identities that they cared about in school, by reconstructing some aspects of their school identity that did not match who they aspired to be, as well as by gaining new resources to enact their desired identities. The examples provided demonstrate that integrating student voice in a science project can make participation in science a valuable tool in students' identity formation. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 667–694, 2006
The Effects of Elevated CO2 Concentration on Soybean Gene Expression. An Analysis of Growing and Mature Leaves
Authors: Ainsworth Elizabeth A. , Rogers Alistair , Vodkin Lila O. , Walter Achim , Schurr Ulrich 
Published: July 2006

Abstract
Improvements in carbon assimilation and water-use efficiency lead to increases in maximum leaf area index at elevated carbon dioxide concentration ([CO2]); however, the molecular drivers for this increase are unknown. We investigated the molecular basis for changes in leaf development at elevated [CO2] using soybeans (Glycine max) grown under fully open air conditions at the Soybean Free Air CO2 Enrichment (SoyFACE) facility. The transcriptome responses of rapidly growing and fully expanded leaves to elevated [CO2] were investigated using cDNA microarrays. We identified 1,146 transcripts that showed a significant change in expression in growing versus fully expanded leaves. Transcripts for ribosomal proteins, cell cycle, and cell wall loosening, necessary for cytoplasmic growth and cell proliferation, were highly expressed in growing leaves. We further identified 139 transcripts with a significant [CO2] by development interaction. Clustering of these transcripts showed that transcripts involved in cell growth and cell proliferation were more highly expressed in growing leaves that developed at elevated [CO2] compared to growing leaves that developed at ambient [CO2]. The 327 [CO2]-responsive genes largely suggest that elevated [CO2] stimulates the respiratory breakdown of carbohydrates, which provides increased energy and biochemical precursors for leaf expansion and growth at elevated [CO2]. While increased photosynthesis and carbohydrate production at elevated [CO2] are well documented, this research demonstrates that at the transcript and metabolite level, respiratory breakdown of starch is also increased at elevated [CO2].
THE EVALUATION OF SOILS AND THE DEFINITION OF QUALITY CLASSES FROM STUDIES OF THE PHYSICAL PROPERTIES OF THE SOIL PROFILE IN THE FIELD
Authors: CLARKE G. R. 
Published: July 2006

SummaryThe relative productivity of certain soil series has been determined from an evaluation of certain physical characteristics of the soil profile which are measurable in the field. The evaluation has been based on the assumption that the most important physical properties of a soil affecting its productivity are its texture, its depth, and the goodness of its drainage.The basis of the evaluation formula is that a rating is given to each textural class, ranging from 20 for a medium loam to 3 for a gravel and 5 for a heavy structureless clay, and this rating is given for each inch down to the bottom of the profile, or to an arbitrary depth of 30 in., whichever is the shallower. These ratings are added together to give a textural value, V, for the soil. If there is any gleying in the top 30 in. this value is then reduced by multiplying by a factor G, which is less than unity and which is smaller the higher the top of the gley horizon. The yield, of wheat, P, as. measured by the weight of ears produced per unit area at any spot in the field was calculated by the formula P = cVG, where c is an arbitrary constant. This prediction formula accounted for 90–7 per cent, of the variance of the wheat yield in 1947, a year in which accurate estimates of the yield were made, but only 68 per cent, of the variance in 1948, a year in which the yield figures were subject to large errors. The formula was less satisfactory for the yield of straw.The formula P = cVG was more accurate than P = cVG where VG is the textural value to the top of the gley horizon, a result interpreted as showing that wheat roots make some use of gleyed soil.
ISOTOPIC EQUILIBRIA BETWEEN PHOSPHATES IN SOIL AND THEIR SIGNIFICANCE IN THE ASSESSMENT OF FERTILITY BY TRACER METHODS
Authors: RUSSELL R. SCOTT , RICKSON J. B. , ADAMS S. N. 
Published: July 2006

AbstractThe isotopic exchange of phosphorus has been studied between solutions of orthophosphate and the following solid phases: anion‐exchange resin charged with phosphate; dicalcium phosphate; rock phosphates; hydroxyapatite aged to varying extents; and natural soils.The nature of exchange reactions in the soil is discussed. It is considered that all inorganic phosphate fractions in the soil undergo exchange with added phosphates, though at different rates.Consideration is given to procedures proposed by earlier workers for the estimation of the phosphate status of the soil by tracer methods. In particular, the hypothesis that‘plant available’soil phosphate can be estimated by comparing the specific activity of phosphate added to the soil with that of phosphate absorbed by plants is examined. It is shown that the method is of limited application. It appears, however, that since‘plant‐available’soil phosphate undergoes isotopic exchange more readily than‘unavailable’forms, it should be possible to estimate available soil phosphate by observing isotopic exchange between solutions and soil suspensions under controlled conditions. The appropriate procedure will vary between soil types and must be determined by ad hoc investigations.The limitations which isotopic exchange and isotopic dilution effects impose on the estimation of fertilizer absorption by tracer methods are discussed.
THE INFLUENCE OF VARIOUS ROTATIONS ON COARSE‐TEXTURED SOILS AT CHAPMAN AND WONGAN HILLS RESEARCH STATIONS, WESTERN AUSTRALIA
Authors: DROVER D. P. 
Published: July 2006

SummaryThe effect of four wheat rotations on soil organic carbon and nitrogen in two long‐term experiments at Chapman and Wongan Hills Research Stations is discussed. The experiments compare continuous wheat, fallow‐wheat, fallowwheat‐pasture, and fallow‐wheat‐z years lupins.On the assumption that adjacent uncultivated soils were comparable in carbon and nitrogen to the original virgin soils, the four‐course rotation is at each site the only one which maintained soil nitrogen at levels approaching those of the virgin soils. The two‐ and three‐course rotations, including in each case a year of fallow, by contrast, produced serious losses in both carbon and nitrogen at both localities, but particularly at Chapman. The soil‐nitrogen data support the hypothesis of Shier and Cullinane (1948) that these levels are influencing wheat yield and the flour quality of the grain.The data emphasize, also, the very low nitrogen and carbon contents of these soils both in the virgin condition and after zz years of a four‐course rotation in which half of each +year period was occupied by a leguminous crop.It is concluded that much longer periods under legumes are necessary if the carbon and nitrogen levels of these soils are to approach those typical of known highly fertile soils elsewhere.
PERMEABILITY MEASUREMENTS IN THE FIELD AS AN ASSESSMENT OF ANISOTROPY AND STRUCTURE DEVELOPMENT
Authors: CHILDS E. C. , COLLIS‐GEORGE N. , HOLMES J. W. 
Published: July 2006

SummaryThirteen sites were examined and the permeabilities determined by a combination of the two‐well (Childs) and the single‐tube (Kirkham) methods. Anisotropy occurred in less than half of these sites. The range of permeabilities encountered was ten‐thousand fold. Two of the clay soils have permeabilities comparable with those of gravelly sands.An argument is presented for the use of permeability as an objective measure of structure in the field and the principal disadvantages of the permeability method are listed.Variability in field structure is considered from the aspect of the ratio between the size of the well sample and the size of the structural units. Four cases of variability are interpreted in terms of their effect on the standard error and the asymmetry of results obtained by the two‐well method. This interpretation is shown to allow of the assessment of field structure from the permeability results. When sub‐units of structure and the experimental equipment have similar dimensions, individual determinations have questionable validity.The method of calculating permeability and anisotropy from field data is given in an Appendix. A comparison of the field descriptions with the permeability results for the experimental sites indicates that qualitative profile differentiation does not always imply a change of permeability; neither can visual profile uniformity be taken to indicate uniform permeability.
STUDIES ON THE BASALTIC SOILS OF NORTHERN IRELAND
Authors: McConaghy S. , McAleese D. M. 
Published: July 2006

SummaryDescriptions and analytical data are given relating to nine basaltic profiles representing soils which have been used in detailed studies on cation‐exchange properties and mineralogical constitution of basaltic soils in Northern Ireland.Three main groups of soils are considered: those with impeded or poor drainage, those with free drainage, and those which have good drainage in the agricultural sense but which show slight signs of mottling in lower horizons. In all three groups of basaltic soils the clay contents and the organic‐carbon contents fall appreciably with depth, but the cation‐exchange‐capacity values do not follow the changes in clay and organic‐matter contents. The total cation‐exchange capacity in the C or G2–3 horizon may be as high as or higher than in the surface horizon. In freely drained profiles the cation‐exchange capacity is generally lower in the B horizon than in the A(S) or in the C horizon, and usually in poorly drained profiles the cation‐exchange‐capacity value is also lowest in the B, G1, or the A2‐G horizon (due mainly to the fall in organic matter). Exchangeable magnesium forms a considerable percentage (up to about 40 per cent.) of the total cations in the C (or the G2) horizons of basaltic soils, and vaues of the order of 20 m.e. exchangeable magnesium per 1OO g. soil are recorded for some such horizons where drainage is impeded.
AFFORESTATION AND SOIL REACTION
Authors: OVINGTON J. D. , MADGWICK H. A. I. 
Published: July 2006

SummaryAn investigation is described of the pH relationships between the soil, litter, and tree leaves at ten experimental areas from 17 to 50 years after planting. At each of these areas a number of different tree species has been established.From the results of 6,900 pH measurements taken in 13 unplanted and 1OO forest plots some general relationships in the pH of tree leaves, litter, and soil are recognized. When a number of tree species are grown under identical conditions the acidity of their leaves and litter layers differs considerably between species. Soil pH is modified differentially by afforestation, largely depending upon the nature of the established tree species and for the ten series of plots it has been possible to prepare a list of tree species graded according to their effect on soil pH. Since the results have been obtained from only ten areas the detailed conclusions must be regarded as tentative. It is suggested that there is a need to establish experiments where the influence of tree species on site conditions can be critically studied. The application of these observations to problems of land use is discussed.
ABNORMALITIES IN NUTRIENT UPTAKE BY CORSICAN PINE GROWING ON AND DUNES
Authors: WRIGHT T. W. 
Published: July 2006

SummaryMonthly variations in foliar N, K, Ca, Mg, and P2O5 of young Corsican pine growing on the sand dunes of Culbin Forest, Morayshire, have been compared with monthly changes in the available moisture in the rooting zone, calculated with the aid of Penman's formula. A reversal of the normal seasonal trends has been observed in the second half of the growing season. In trees showing poor growth, heavy thinning delayed the drying out of the rooting zone and temporarily improved the K, Mg, and N levels in the foliage.
FEATURES OF SOME SEMI‐ARID SOILS IN THE DISTRICT OF KHARTOUM, SUDAN
Authors: WORRALL G. A. 
Published: July 2006

SummaryTwo soil groups in the Khartoum district are described. The Red Sand‐Iron‐stone Soils are characterized by a reddish sandy upper horizon, a second ironstone gravel horizon, and a third stony horizon, often consisting of kankar. They are dry soils, and contain very little soluble salts or plant nutrients, and the minerals are largely quartz and iron ores. The few heavy minerals show resemblance to those of the High Level Dark Clays in particular in their amounts of hornblende and epidote.The resemblance of the red sand to the ‘Goz’ and the ironstone gravel to murram of laterite areas is noted and discussed, and evidence is produced for attributing the origin of both to the weathering of the rocks of the Nubian Series, and the soils are regarded as intrazonal.The Riverain Soils of the Blue Nile and Main Nile have very variable textures, but the White Nile Clays are remarkably uniform in texture and profile. The differences can be attributed to the difference in the régime of the rivers. Salinity is also variable, but usually much lower than in the High Level Dark Clays, and the more saline soils are heavy‐textured and lying in slight depressions.The mineral content is similar in all the Riverain Soils except for the White Nile Clays which show some differences, and also similar to that in the High Level Dark Clays. The sources of the minerals are discussed, and a suggested mode of formation of the flood plain, by which islands link with the mainland, is proposed.
FACTORS AFFECTING THE ABILITY OF PLANTS TO ABSORB PHOSPHATE FROM SOILS
Authors: RUSSELL R. SCOTT , RUSSELL E. W. , MARAIS P. G. 
Published: July 2006

SummaryThe relationship between the absorption of phosphate by plants and labile soil phosphate has been investigated in four soils ranging from a calcareous alluvium to basaltic soils of reputed high ‘phosphate‐fixing’ capacity. Labile phosphate has been determined both by isotopic exchange and by applying the principles of isotopic dilution to the results obtained when plants are grown in soils to which labile phosphate has been added (the method of Larsen). The two measures gave generally similar but not identical results.Aliquots of each soil type were enriched with varying quantities of phosphate to give series of soils similar in all respects other than their phosphate status. The soils were sometimes stored for periods of up to a year before further examination was carried out. A large fraction of the added phosphate always remained in a labile form. In each such series of artificially enriched soils a closely linear relationship was found between absorption by test plants and the labile soil phosphate. Soils of contrasting origin, however, showed no such correlation, but absorption was related to the reciprocal of the quantity of phosphate sorbed by the soils from phosphate solutions under standard conditions.An interpretation of the factors which determine the extent to which phosphate can be absorbed by plants from different soils is advanced in terms of the concepts of phosphate ‘potential’ and ‘capacity’ introduced by Schofield. The labile soil phosphate is not, however, regarded as homogeneous; evidence of wide variation in activation energy between different labile‐phosphate fractions has been obtained.When used to assess the phosphate status of agricultural soils, tracer methods appear to be subject to limitations similar to those of the older extraction procedures.