bluuebunny/crossref_metadata_2025 huggingface dataset:
The Fate of Nitrogen Applied to a Mature Kentucky Bluegrass Turf
Authors: Frank Kevin W. , O'Reilly Kevin M. , Crum James R. , Calhoun Ronald N.
Published: December 2005

Research on nitrate‐nitrogen (NO3–N) leaching in turfgrass indicates that, in most cases, leaching poses little risk to the environment. Most of the research was conducted on sites that were recently established, and the potential for greater NO3–N leaching from mature turf sites is unknown. The fate of nitrogen (N) was examined for a 10‐yr‐old Kentucky bluegrass (Poa pratensis L.) turf using intact monolith lysimeters and microplots. From October 2000 through July 2002, half of the lysimeters and microplots were treated annually with urea at a high rate of 245 kg N ha−1 (49 kg N ha−1 application−1). The remaining lysimeters and microplots were treated annually with urea at a low rate of 98 kg N ha−1 (24.5 kg N ha−1 application−1). The Oct. 2000 urea application was made with 15N double‐labeled urea to facilitate fertilizer identification among clippings, verdure, thatch, soil, roots, and leachate. The average total recovery of applied labeled fertilizer nitrogen (LFN) for the low and high N rates was 78 and 74%, respectively. NO3–N concentrations in leachate for the low N rate were typically below 5 mg L−1. For the high N rate, NO3–N concentrations in leachate were often greater than 20 mg L−1. Over approximately 2 yr, 1 and 11% of LFN was recovered in leachate for the low and high N rates, respectively. This research indicates that single dose, high rate, water soluble N applications (49 kg N ha−1 application−1) to mature turfgrass stands should be avoided to minimize the potential for NO3–N leaching.
Intake and Digestion of ‘Jesup’ Tall Fescue Hays with a Novel Fungal Endophyte, without an Endophyte, or with a Wild‐Type Endophyte
Authors: Burns J. C. , Fisher D. S.
Published: December 2005

Tall fescue (Festuca arundinaceaSchreb.) is an important forage resource for beef (Bos taurusL.) production in the North–South transition zone. Recently, the cultivar ‘Jesup’ was released to provide improved stand survival when infected with a novel (nontoxic) endophyte marketed as MaxQ (Pennington Seed, Madison, GA), and warrants evaluation as a source of winter hay for beef cattle. Intake and digestion experiments were conducted to evaluate Jesup tall fescue containing the MaxQ endophyte (presumably without ergot alkaloids), Jesup with no endophyte, and Jesup with a wild‐type endophyte capable of producing ergot alkaloids. Initial growth of the three endophyte treatments was harvested in April and a regrowth harvested in June. These six hays were fed to goats (Capra hircusL.) and sheep (Ovis ariesL.). The hays harvested in June were also fed to cattle. The digestibility of the endophyte treatments was similar but goats had greater daily dry matter intake when fed MaxQ compared with wild‐type hay (2.63 vs. 2.43 kg 100−1kg body weight;P= 0.07) while intake was similar to the endophyte‐free hay. Sheep consumed hays similarly, regardless of harvest date, as did steers fed the June harvest. Daily intake of hays harvested in April and June were similar for goats, whereas sheep consumed more of the April hays (2.89 vs. 2.57 kg 100−1kg body weight;P< 0.01) and both digested the April hays to a greater extent. Endophyte status of the hays had little influence on their quality.
Estimating the Potential for Facilitated Transport of Napropamide by Dissolved Organic Matter
Authors: Williams C. F. , Letey J. , Farmer W. J.
Published: December 2005

Dissolved organic matter (DOM) has been found to significantly affect the soil sorption/desorption of napropamide [2‐(α‐naphthoxy‐N, N‐diethylpropionamide] and to enhance its transport through soil columns. A method to qualitatively predict if DOM will enhance the transport of napropamide based on easily determined sorptive characteristics is investigated. Batch sorption experiments were specifically designed to simulate field application of napropamide. The formation of a napropamide–DOM complex was enhanced by pretreating soils with pesticide and allowing the carrier solvent to evaporate prior to preparing a water extract of the soil (K1). A second adsorption coefficient was measured by equilibrating K1 with untreated soil (K2). Column transport studies using the same soils as the batch equilibrium studies were performed. After allowing napropamide to dry, columns were leached. Initial leachate from all soils contained napropamide indicating that the collected napropamide had been transported through the column without adsorption. However, the amount leached was dependant on soil type and in general soils with higher organic matter content had higher concentrations of napropamide in the initial 30 mL of leachate when compared with lower organic matter (OM) soils. The ratio of the K1 and K2 solutions from the batch equilibrium studies were found to be positively correlated with the mass of napropamide in the initial leachate. Therefore the ratio of K1 to K2 provided a better qualitative predictor of the potential for facilitated transport of napropmamide than soil OM content.
Spatial Distribution of Microbial 2,4‐Dichlorophenoxy Acetic Acid Mineralization from Field to Microhabitat Scales
Authors: Vieublé Gonod Laure , Chadoeuf Joël , Chenu Claire
Published: December 2005

Little is known about spatial variability of microbial activity, particularly at microscales. This is especially true for the fate and degradation of pesticides. The objective was to sample soil from micro to field scales and apply geostatistics on the potential mineralization of a widely used herbicide 2,4‐dichlorophenoxy acetic acid (2,4‐D; C8H6Cl2O3). Soil cores were sampled in the plow layer of a cultivated soil with a systematic sampling procedure. In a first experiment 2,4‐D mineralization was measured on 39 crushed cores and we analyzed variability of mineralization at the field scale, from decameter to meter and from meter to decimeter scale. In a second experiment, 432 soil cubes (about 216 mm3) were used to study the variability of mineralization at the “microhabitat” scale from meter to millimeter. The spatial dependence of 2,4‐D mineralization was first quantified by computing an empirical variogram function. Spatial independence was then tested by comparing the empirical variogram function to its individual confidence bounds at 95% level obtained under independence assumption by a Monte‐Carlo Method.

The potential for 2,4‐D mineralization was spatially heterogeneous from field to microhabitat. Mineralization variability increased when the scale decreased from field to microhabitats.

Specifically, the coefficient of variability (CV) of 2,4‐D mineralization was of 18.5% at the field scale, 7–22% at the meter scale, 47.9% at the inter‐cores scale, and 25–160% at the intra‐core scale (microhabitat scale). 2,4‐D mineralization was spatially structured only at the microhabitat scale (hot spots). This variability at fine scales should be considered when sampling soil processes involving microbial activities.
Hydration Energy Determines Isovalent Cation Exchange Selectivity by Clay Minerals
Authors: Teppen Brian J. , Miller David M.
Published: December 2005

Cation exchange is one of the most venerable concepts in soil science, yet it needs rethinking. This paper presents an extremely simple conceptual framework for interpreting many observed trends in cation exchange. Taking the example of Cs‐K exchange, the methods of computational molecular mechanics found that Cs‐montmorillonite is considerably higher in energy than K‐montmorillonite at constant water content, in agreement with inferences from a new thermodynamic cycle representation of cation exchange. Since montmorillonite selects Cs+ over K+ in real experiments, these results mean that alkali cation‐exchange selectivity is controlled by selectivity of the solution phase for the more strongly hydrated cation. Thus the clay does not “select” for Cs+ over K+ in any positive sense and it may be more useful to consider cation exchange as a partitioning reaction: Given two cations of equal valence, the more weakly hydrated will tend to partition into the “subaqueous” smectite interlayer phase. This concept seems not only parsimonious, but also more accurate than other hypotheses for cation exchange selectivity that impute more favorable interactions between smectite surfaces and the selected cations; such theories err by ignoring energy changes in the solution phase. This simple partitioning concept rationally explains the alkali and alkaline earth selectivity sequences as well as the selectivities of smectites for organic cations over inorganic, for larger organic cations over smaller, and for organometallic complexes over the uncomplexed metal.
Organic Matter Study of Whole Soil Samples Using Laser‐Induced Fluorescence Spectroscopy
Authors: Milori Débora Marcondes Bastos Pereira , Galeti Helder Vinicius Avanço , Martin-Neto Ladislau , Dieckow Jeferson , González-Pérez Martha , Bayer Cimélio , Salton Júlio
Published: December 2005

Fluorescence spectroscopy relies on the fluorescence emitted by rigid conjugated systems and thus can be used to assess the soil organic matter (SOM) humification. This technique is generally applied to solution samples of humic substances, and so far no information exists about its applicability to whole untreated soil samples. The laser‐induced fluorescence (LIF) spectroscopy is proposed as a novel technique to assess the organic matter humification in whole soil samples. We sampled the 0‐ to 2.5‐, 2.5‐ to 5‐, 5‐ to 10‐, 10‐ to 15‐, and 15‐ to 20‐cm layers of three Oxisols of long‐term experiments located in two sites of the Brazilian Cerrado. The humification index based on LIF spectroscopy (HLIF) of whole soil samples showed a close correlation with the humification indexes A4/A1, I465/I399, and A465 obtained after fluorescence spectroscopy analysis of the dissolved humic acids. The HLIF in soils under native cerrado or subjected to no‐tillage increased from the top to the deepest layer, which is consistent with the deposition of labile organic matter from plant residues on the soil surface. The soils subjected to conventional tillage, however, showed relatively constant HLIF along the profile, possibly because homogenization imparted by disturbance of the arable layer. Accordingly, for the two top layers, the soils under no‐tillage showed a lower HLIF than for conventionally tilled soils. Laser‐induced fluorescence spectroscopy is a promising technique to assess humification in whole soil samples, particularly in Oxisols, which due to high concentration of Fe3+ are not feasible to electron spin resonance (ESR) and Carbon‐13 nuclear magnetic resonance (13C NMR) spectroscopy, unless previous treatment is employed.
Percolation Treatment of Charge Transfer in Humidified Smectite Clays
Authors: Hunt Allen G. , Logsdon Sally D. , Laird David A.
Published: December 2005

Bulk electrical conductivity of soil is generally assumed to be dominated by the electrical conductivity of the soil solution, with perhaps a small contribution from surface charges associated with soil solids. Soils high in smectites often exhibit high electrical conductivity due to water associated with the clays. These charges are either associated with the exchangeable cations or with proton migration in the clay‐associated water. The purpose of this study was to use percolation principles to elucidate mechanisms of charge transfer in humidified smectites. The theory predictions were compared with electrical conductivity spectra measured for mono‐ionic humidified smectites. The measured spectra were consistent with a percolation model of proton hopping in the maximum interlayer spacing beyond a threshold water content, plus an offset term for some samples. The threshold water content for percolation in the maximum interlayer spacing was 0.07 m3 m−3, which was assumed the same for all basal spacings. The spectra should converge at the phonon frequency (vph), but for some samples at the higher humidity levels, the spectra were offset. The samples with this offset were determined by examining the spectra for the same mono‐ionic smectite at different humidity levels. The mean offset level was 0.015 m3 m−3 and was likely related to charge transfer on external surfaces. The phonon frequency fitted across all samples was 3.54 × 108 Hz, lower than the 1012 Hz often assumed. These results are generally consistent with the idea that water associated with smectite clays generated the observed electrical conductivity.
Phosphorus Loss in Runoff from Long‐term Continuous Wheat Fertility Trials
Authors: Zhang H. , Schroder J. L. , Davis R. L. , Wang J. J. , Payton M. E. , Thomason W. E. , Tang Y. , Raun W. R.
Published: December 2005

Some wheat (Triticum aestivum L.) farmers in the southern Great Plains routinely apply P fertilizer without soil testing. This practice may lead to P buildup in soils, hence, increased P runoff potential, making soil P management of concern in continuous wheat production. At present, there is also debate over the nature of P loss trends, particularly whether soil P release to runoff can be described generally, across a broad range of soils, or is soil‐specific. Paired 1 m by 2 m runoff plots were established on three existing long‐term continuous winter wheat fertility experiments. Two experiments have received annual fertilizer P application at different rates since 1970 (0–44 kg P ha−1), and the third received a one‐time P application at much higher rates in 1977 (0–587 kg P ha−1). Rainfall‐runoff experiments were conducted following the National P Research Project protocol. Simulated rain (75 mm h−1) produced 30 min of runoff from plots with different soil test P levels. Soil Mehlich‐3 P (M3P) ranged from 11.5 to 130 mg kg−1 and water‐soluble P (WSP) ranged from 0.70 to 15.7 mg kg−1 Runoff total P and dissolved reactive P (DRP) concentrations ranged from 0.47 to 1.5 and 0.03 to 0.70 mg L−1, respectively. Dissolved reactive P in runoff was significantly related to M3P, WSP, and ammonium oxalate P saturation index (PSIox) for combined soils as well as for individual soil series. Significant differences (p < 0.05) among the slopes of the regressions for the DRP‐M3P, DRP‐WSP, and DRP‐PSIox relationships indicate that the relationships are soil specific. This study highlights the need for soil specific management to protect water quality.
Soil Water Regime in Space and Time in a Small Georgia Piedmont Catchment under Pasture
Authors: Endale D. M. , Fisher D. S. , Schomberg H. H.
Published: December 2005

Soil water influences hydrological, biological, and biogeochemical processes that determine on‐ and off‐site response of landscapes under different agricultural uses. There are relatively little detailed spatial and temporal soil water measurements to validate current representations of spatial and temporal soil water variability. Soil water was measured over 3 yr at 12 sites to a 1.2‐m depth in a 7.8‐ha pasture catchment in the Georgia Piedmont in southeastern USA. The Mahalanobis statistical difference was estimated between all pairs of measurement sites for soil water. Multidimensional scaling of the Mahalanobis differences showed that only a single statistical dimension was separating the observed soil water variations at measurement sites (r = 0.99). This statistical dimension was then found to be most closely correlated with the depth to the Bt and the depth of the Ap horizons for explaining the observed variation in soil water between sampling sites (r = 0.69 and r = 0.8, respectively). Those sites where the Bt, an argillic horizon, was close to the surface, even when higher up the landscape, were generally wetter than those in which the Bt was deeper, even in the lower part of the landscape. The depth to the Bt horizon may serve as an indicator of the portions of the watershed most likely to be primary sources of runoff in association with the depth of overlying coarse‐textured soil. Volumetric soil water content was generally greatest in winter (22 to 30% average) and least in summer (8 to 12% except when influenced by intense summer storms). To fully understand the soil water dynamics of Piedmont or similar landscapes, it is important to know the spatial distribution of the depth to the Bt horizon. Improved understanding of the soil water dynamics could lead to improved land use decisions, erosion control, and management of water resources. This should be of interest to many researchers across many disciplines.
Spatial Variability of Substrate Water Content and Growth of White Spruce Seedlings
Authors: Lamhamedi Mohammed S. , Labbé Louise , Margolis Hank A. , Stowe Debra C. , Blais Louis , Renaud Mario
Published: December 2005

Irrigation by jet‐type sprinklers contributes to the spatial variability of substrate water content and growth of containerized white spruce [Picea glauca (Moench) Voss.] seedlings grown outdoors during their second growing season. Geostatistical analyses were used to identify the spatial structure of this variability throughout the growing season and to help develop a sampling strategy to facilitate irrigation management. Boundary line analysis confirmed that the heterogeneity of height growth is related to seasonal variations in substrate water content and that maximum height growth and seedling biomass is attained when average seasonal substrate water content is approximately 40% (v/v). Parameters estimated from semi‐variograms, most notably the range (a) and total variance (C0 + C1) of substrate water content, can be used to define sampling strategies specific to irrigation management and morphophysiological evaluation of seedlings. The relationship between leaching and substrate water content can be used, in conjunction with kriged maps, to estimate potential losses of mineral nutrients and to quantify water use for the production of white spruce seedlings during their second growing season in a forest nursery. More than 15% of the seedlings in the crop used in the present study were rejected at delivery. Knowledge of the spatial variability within a crop enables forest nurserymen to modify sampling techniques and cultural practices, produce more uniform seedlings and reduce the quantity of seedlings that fail to meet morphophysiological criteria.
Soil Management and Landscape Variability Affects Field‐Scale Cotton Productivity
Authors: Terra J. A. , Shaw Joey N. , Reeves D. W. , Raper R. L. , van Santen E. , Schwab E. B. , Mask P. L.
Published: December 2005

A better understanding of interactions between soil management and landscape variability and their effects on cotton (Gossypium hirsutum L.) productivity is needed for precision management. We assessed management practices and landscape variability effects on seed cotton yield in a 9‐ha, Alabama field (Typic and Aquic Paleudults) during 2001–2003. We hypothesize that landscapes have major effects on cotton productivity, but these effects vary based on management and climate. Treatments were established in replicated strips traversing the landscape in a corn (Zea mays L.)–cotton rotation. Treatments included a conventional system with or without 10 Mg ha−1yr−1 dairy manure (CTmanure or CT), and a conservation system with and without manure (NTmanure or NT). Conventional systems consisted of chisel plowing/disking + in‐row subsoiling without cover crops. Conservation systems combined no surface tillage with in‐row subsoiling and winter cover crops. A soil survey, topographic survey, and interpolated surfaces of soil electrical conductivity (EC), soil organic carbon (SOC), and surface soil texture were used to delineate five zones using fuzzy k‐means clustering. Overall (2001–2003), conservation systems improved cotton yield compared with conventional systems (2710 vs. 2380 kg ha−1); neither manure nor treatment × year interactions were significant. The conservation system was more productive than the conventional system in 87% of the cluster × year combinations. Slope, EC, SOC, and clay content were correlated with yield in all treatments. Soil and terrain attributes explained 16 to 64% of yield variation, however, their significance fluctuated between years and treatments. In dry years, factor analyses suggested variables related with soil quality and field‐scale water dynamics had greater impacts on CT yields than NT yields. Our results indicate that management zones developed using relatively static soil‐landscape data are relatively more suitable for conservation systems, and these zones are affected by soil management. In addition, the impact of NT on yields is most apparent on degraded soils in dry years.
Soil Organic Matter in a West Bengal Inceptisol after 30 Years of Multiple Cropping and Fertilization
Authors: Manna M. C. , Swarup A. , Wanjari R. H. , Singh Y. V. , Ghosh P. K. , Singh K. N. , Tripathi A. K. , Saha M. N.
Published: December 2005

Rice‐based multiple cropping systems are predominant in the Indo‐Gangetic Plains of Indian subcontinent. A decline in yield of such systems has been observed and ascribed to quantitative and qualitative variations of soil organic matter (SOM). We evaluated the impact of the annual rotation: rice (Oryza sativa L.), wheat (Triticum aestivum L.), jute (Corchorus olitorius L.), with and without fertilizer treatments (control, N, N–P, N–P–K, and N–P–K plus farmyard manure [FYM]) on SOM and aggregate properties. At 0‐ to 15‐cm soil depth, microbial biomass C and N, hot water–soluble C and N and hydrolyzable carbohydrates, and particulate organic matter C (POMC) and N (POMN) were found in the order N–P–K plus FYM > N–P–K > N–P > N > control. Over the course of the experiment, application of N alone decreased total organic C (TOC) by 20.4%, whereas N–P–K with or without FYM addition either maintained or enhanced compared to initial. Total soil N and mineralizable N declined in all the treatments except N–P–K plus FYM. Irrespective of treatments, microaggregates (53–250 μm) dominated with 43.9 to 51.3% of total soil aggregate size distribution, followed by macroaggregates (250–2000 μm with 34.6 to 40.1%). The C and N mineralization rate was greater in macroaggregates than in microaggregates, and correlated significantly with POMC (r = 0.67, P ≤ 0.01) and POMN (r = 0.88, P ≤ 0.01). Nitrogen–phosphorus–potassium plus FYM also improved overall soil aggregation as compared to other treatments. Therefore, the results suggest that the gradual depletion of nutrients and structural degradation may have collectively contributed to the crop yield declines in the rice–wheat–jute rotation and that the integrated use of N–P–K and FYM is an important nutrient management option for sustaining this cropping system.
Scenarios for future agriculture in Finland: a Delphi study among agri-food sector stakeholders
Authors: RIKKONEN P.
Published: December 2005

This article presents alternative scenarios for future agriculture in Finland up to 2025. These scenarios are the results of a large Delphi study carried out among Finnish agri-food sector stakeholders. The Delphi panel members gave their future view on desirable and probable futures. From these two dimensions, three scenarios were elaborated through the future images  the subjective future path and the importance analysis. The scenarios represent a technology optimistic day-dream agriculture, a probable future as industrialised agriculture and an undesirable future path as drifting agriculture. Two mini-scenarios are also presented. They are based on a discontinuity event as an unexpected impact of climate change and an analogy event as an ecological breakdown due to the expansive animal disease epidemics. In both mini-scenarios, the directions of storylines are dramatically changed. The scenarios support strategic planning introducing not only one forecast but alternative outcomes as a basis for future strategy and decisions. In this study the scenarios were constructed to address the opportunities as a desired vision and also the threats as to an undesirable future in the agricultural sector. These results bring to the table a Finnish agri-food expert community view of the future directions of relevant key issues in the agricultural policy agenda.;
Crop and soil specific N and P efficiency and productivity in Finland
Authors: BÄCKMAN S. , LANSINK A.
Published: December 2005

This paper estimates a stochastic production frontier based on experimental data of cereals production in Finland over the period 1977-1994. The estimates of the production frontier are used to analyze nitrogen and phosphorous productivity and efficiency differences between soils and crops. For this input specific efficiencies are calculated. The results can be used to recognize relations between fertilizer management and soil types as well as to learn where certain soil types and crop combinations require special attention to fertilization strategy. The combination of inputs as designed by the experiment shows significant inefficiencies for both N and P. The measures of mineral productivity and efficiency indicate that clay is the most mineral efficient and productive soil while silt and organic soils are the least efficient and productive soils. Furthermore, a positive correlation is found between mineral productivity and efficiency. The results indicate that substantial technical efficiency differences between different experiments prevail.;
Personality, pupils, and purple cows: we have the right answers, but do we have the right questions?
Authors: Sternberg Robert J.
Published: December 2005

In this article, I consider first the questions about the relation between personality and education that we have, to a large extent, answered, and then the questions that we have yet to answer, and, in large part, even to ask.
Laser Desorption Mass Spectrometry of Synthetic Multiporphyrin
Arrays
Authors: FENYO DAVID , CHAIT BRIAN T. , JOHNSON THOMAS E. , LINDSEY JONATHAN S.
Published: December 2005

Laser desorption mass spectrometry and matrix-assisted laser desorption
mass spectrometry (MALDI-MS) have been investigated for the analysis of a
set of synthetic compounds containing one, two, five, eight or nine
porphyrins. Intact singly ionized molecule ions were observed for each
compound and the spectra were readily interpretable. The use of a matrix of
4-hydroxy-α-cyano-cinnamic acid greatly diminished the extent of
fragmentation. Examination of the resulting mass spectra provides insight
into aspects of the MALDI process. The present results show that high
molecular weight photochemically active materials that absorb strongly at
the wavelength of laser illumination can be analysed effectively and that
MALDI-MS is a powerful analytical tool for synthetic chemistry of
porphyrin-based molecules with dimensions ranging to 10 nm. The strong
molecule ions observed for the largest compounds investigated ( Zn
8-octamer, Zn 9-nonamer)
indicates that this method should be applicable to even larger porphyrin
arrays.
Labile Electronic Ground State of the π-Cation Radical of Zinc(II) Tetraphenylporphyrin: a Variable-temperature ESR Investigation
Authors: DAVE PARESH C. , SRINIVAS D.
Published: December 2005

The UV-vis and variable-temperature X-band EPR spectral studies (298–77 K) on π-cation of zinc(II) tetraphenylporphyrin ( ZnTPP ) have revealed for the first time a labile electronic ground state. The electronic structure changes from 2 A 2u to 2 A 1u as the temperature is lowered from 298 to 150 K. Axial ligands and σ-donor solvents show a significant effect on the spectral data. The lability in the ground state electronic configuration is attributed to the flexibility of the porphyrin moiety in changing from a ‘ruffled’ to a lower symmetry.
The Mechanism of Dioxygen Reduction at Iron meso-Tetrakis (Pyridyl) Porphyrin: a Spectroelectrochemical Study
Authors: POPOVICI S. , LEYFFER W. , HOLZE R.
Published: December 2005

The mechanism of the dioxygen interaction with and reduction reaction at iron α,β,γ,δ-tetra(4-pyridyl) porphyrin ( FeTPyP ) deposited on carbon and silver supporting electrodes was investigated with cyclic voltammetry and FTIR, UV-vis and resonance Raman spectroscopies. Results indicate a strong influence of the ligand upon the reduction electrocatalysis. Spectroelectrochemical results support a two-electron pathway resulting most probably in hydrogen peroxide as the primary reduction product.
Ground and Excited State Electronic Properties of Halogenated Tetraarylporphyrins: Tuning the Building Blocks for Porphyrin-based Photonic Devices
Authors: YANG SUNG IK , SETH JYOTI , STRACHAN JON-PAUL , GENTEMANN STEVE , KIM DONGHO , HOLTEN DEWEY , LINDSEY JONATHAN S. , BOCIAN DAVID F.
Published: December 2005

The rational design of molecular photonic devices relies on the ability to select components with predictable electronic structure, excited state lifetimes and redox chemistry. Electronic communication in multiporphyrin arrays depends critically on the relative energies and electron density distributions of the frontier molecular orbitals, especially the energetically close highest occupied molecular orbitals (a2u and a1u). To explore how these ground and excited state properties can be modulated, we have synthesized and characterized 40 free base ( Fb ), magnesium and zinc tetraarylporphyrins. The porphyrins bear meso-substituents with the following substitution patterns: (1) four identical substituents (phenyl, o-chlorophenyl, p-chlorophenyl, o,o'-difluorophenyl, pentafluorophenyl, mesityl); (2) one, two, three or four o,o'-dichlorophenyl substituents; (3) one p-ethynylphenyl group and three mesityl or pentafluorophenyl groups; (4) one p-ethynyl-o,o″-dichlorophenyl or p-ethynyl-o,o″-dimethylphenyl and three phenyl groups. For each neutral complex the ground state electronic properties were investigated using electrochemical methods and optical absorption spectroscopy. Similarly the absorption, emission, and relaxation properties of the lowest singlet excited state were probed by time-resolved absorption and fluorescence methods. Each oxidized complex was investigated by static absorption and liquid and frozen solution EPR spectroscopy. The collective results of these investigations have provided insights into the direct (orbital overlap) and indirect (inductive/conjugative) mechanisms by which halogenated phenyl rings influence the static and dynamic electronic properties of neutral and oxidized porphyrinic chromophores. Three key findings are as follows. (1) The effective electron-withdrawing strength of halogenated phenyl rings required to reverse the ordering of the a2u and a1u HOMOs in Mg versus Zn tetraarylporphyrins has been elucidated. (2) Appropriate halogenation can significantly increase the excited state lifetime of a Zn porphyrin relative to the unsubstituted complex. (3) Halogenation can be used to modulate redox potentials in a manner that complements the enhancement of other electronic properties. The insights gained from study of this library of porphyrins provide a foundation for tuning the electronic properties of monomeric porphyrins as building blocks for multichromophoric assemblies in optoelectronics and other applications.
Pyridine and Pyridine Derivatives
Authors: Scriven Eric F. V. , Murugan Ramiah
Published: December 2005

Commercial manufacture, industrial chemistry, and market uses of pyridine and pyridine compounds are reviewed. Pyridines often serve as intermediates for manufacture of products that are bioactive, such as medicinals, herbicides, insecticides, and fungicides. Significant end products for these market applications are identified. Important physical properties are also listed. Discussion of manufacture includes raw materials used, energy utilization, economics, toxicity of compounds, and safety factors.
Tin and Tin Alloys
Authors: Gaver Charles C. ,   Updated by Staff
Published: December 2005

Tin is one of the world’s most ancient metals. In most cases, tin is used on or in a manufactured material in small amounts, much out of proportion to the purpose it serves. Tin in some form has been associated with the economic and cultural growth of civilization. Food preservation and canning developed rapidly with the invention of tin‐coated steel; transportation and high speed machinery became a reality with the invention of tin‐base bearing metals; the casting of type metal was an important advance in printing technology; bronze alloys became weapons, tools, and architectural objects; and telecommunications and electronic equipment depend on the tin‐lead soldered joint. New solders are expected to be lead‐free. In modern technology, uses of tin include the plating of protective coatings, nuclear energy, plastics and other polymers, agriculture, biochemistry, electronic packaging, and glassmaking. Physical properties, chemical properties, processing, economic aspects, specifications and analytical methods, health and safety factors, and uses of tin are discussed.
Synthesis of 2‐Haloalkylpyridines via Cp*RuCl‐Catalyzed Cycloaddition of 1,6‐Diynes with α‐Halonitriles. Unusual Halide Effect in Catalytic Cyclocotrimerization
Authors: Yamamoto Yoshihiko , Kinpara Keisuke , Nishiyama Hisao , Itoh Kenji
Published: December 2005

In the presence of 2–5 mol % Cp*RuCl (cod), various 1,6‐diynes reacted with α‐monohalo‐ and α,α‐dihalonitriles at ambient temperature to afford 2‐haloalkylpyridines in 42–93% isolated yields. The failure of acetonitrile, N,N‐dimethylaminoacetonitrile, phenylthioacetonitrile, and methyl cyanoacetate as nitrile substrate clearly showed that the α halogen substitution is essential for the present cycloaddition under mild conditions. The cycloaddition of unsymmetrical diynes bearing a substituent on one alkyne terminal gave 2,3,4,6‐substituted pyridines exclusively.
Stability of protease in organic solvent: Structural identification by solid‐state NMR of lyophilized papain before and after 1‐propanol treatment and the corresponding enzymatic activities
Authors: Matsubara Teruhiko , Fujita Risa , Sugiyama Shigeru , Kawashiro Katsuhiro
Published: December 2005

Lyophilized enzyme powder is often used in organic solvents. However, the enzymatic activity decreases during the reaction process. In the present study, the relation between structural stability and enzymatic activity in an organic solvent was investigated. 13C cross‐polarization magic angle spinning NMR spectroscopy was used to determine the secondary structure of lyophilized papain in the solid‐state. Deconvolution of the peaks of the backbone carbonyl carbons suggested that the proportion of β‐sheet conformation increased after lyophilization from a phosphate buffer solution. The esterification of N‐benzyloxycarbonyl phenylalanylalanine amide was attempted using the lyophilized papain as a catalyst in anhydrous 1‐propanol. The yield of ester was 46.1% after 48 h at 50°C, but this reaction slowed remarkably after 48 h. When the lyophilized papain was suspended in anhydrous 1‐propanol for 7 days without the substrate, the proportion of β‐sheet conformation was further increased and the suspended papain had no activity. These results suggest that the increase in β‐sheet conformation caused inactivation of papain. The increase in β‐sheet conformation caused by both lyophilization and suspension in propanol was found, which was related to a decrease in enzymatic activity. © 2005 Wiley Periodicals, Inc.
Changes in acquired immunodeficiency syndrome‐related non‐Hodgkin lymphoma in the era of highly active antiretroviral therapy
Authors: Diamond Catherine , Taylor Thomas H. , Aboumrad Tabatha , Anton‐Culver Hoda
Published: December 2005

BACKGROUND

The authors sought to determine whether the availability of highly active antiretroviral therapy (HAART) coincided with changes in the epidemiology of acquired immunodeficiency syndrome (AIDS)‐related non‐Hodgkin lymphoma (NHL).

METHODS

Cancer registry data from 1988–2000 were linked with AIDS registry data from 1981 to July 2003 for San Diego County to identify 537 AIDS‐NHL patients. By using the total number of patients with AIDS who were alive as of July 1 annually as the AIDS population denominator, the average annual incidence of NHL was estimated among patients with AIDS for the pre‐HAART period (1988–1995) and post‐HAART period (1996–2000). The chi‐square test was used to compare proportions, and a Cox proportional hazards model was used to compare survival between the pre‐HAART and post‐HAART periods.

RESULTS

The incidence of NHL decreased from 29.6 per 1000 person‐years pre‐HAART to 6.5 per 1000 person‐years post‐HAART. The proportion of patients who had NHL of central nervous system (CNS) origin decreased from 28% pre‐HAART to 17% post‐HAART. Among patients with systemic NHL, 54% received chemotherapy pre‐HAART, and 72% received chemotherapy post‐HAART. The percentage of intermediate‐grade NHL increased from 33% pre‐HAART to 49% post‐HAART, and the percentage of high‐grade NHL decreased from 38% to 19%, respectively. A diagnosis of human immunodeficiency virus infection preceding the NHL diagnosis and Stage IV NHL were associated with worse survival, whereas a diagnosis of NHL in the post‐HAART period and chemotherapy were associated with better survival. The median survival was 4 months pre‐HAART and 9 months post‐HAART.

CONCLUSIONS

Since the introduction of HAART, there has been a decrease in the incidence of systemic and CNS NHL among patients with AIDS. Among patients with systemic, AIDS‐related NHL, there has been decreased high‐grade histology, increased use of chemotherapy, and improved survival. Cancer 2006. © 2005 American Cancer Society.
Systemic application of CpG‐rich DNA suppresses adaptive T cell immunity via induction of IDO
Authors: Wingender Gerhard , Garbi Natalio , Schumak Beatrix , Jüngerkes Frank , Endl Elmar , von Bubnoff Dagmar , Steitz Julia , Striegler Jörg , Moldenhauer Gerd , Tüting Thomas , Heit Antje , Huster Katharina M. , Takikawa Osamu , Akira Shizuo , Busch Dirk H. , Wagner Hermann , Hämmerling Günter J. , Knolle Percy A. , Limmer Andreas
Published: December 2005

CpG‐rich oligonucleotides (CpG‐ODN) bind to Toll‐like receptor 9 (TLR9) and are used as powerful adjuvants for vaccination. Here we report that CpG‐ODN not only act as immune stimulatory agents but can also induce strong immune suppression depending on the anatomical location of application. In agreement with the adjuvant effect, subcutaneous application of antigen plus CpG‐ODN resulted in antigen‐specific T cell activation in local lymph nodes. In contrast, systemic application of CpG‐ODN resulted in suppression of T cell expansion and CTL activity in the spleen. The suppressive effect was mediated by indoleamine 2,3‐dioxygenase (IDO) as indicated by the observation that CpG‐ODN induced IDO in the spleen and that T cell suppression could be abrogated by 1‐methyl‐tryptophan (1‐MT), an inhibitor of IDO. No expression of IDO was observed in lymph nodes after injection of CpG‐ODN, explaining why suppression was restricted to the spleen. Studies with a set of knockout mice demonstrated that the CpG‐ODN‐induced immune suppression is dependent on TLR9 stimulation and independent of type I and type II interferons. The present study shows that for the use of CpG‐ODN as an adjuvant in vaccines, the route of application is crucial and needs to be considered. In addition, the results indicate that down‐modulation of immune responses by CpG‐ODN may be possible in certain pathological conditions.

See accompanying commentary: http://dx.doi.org/10.1002/eji.200535667
Feeding enrichment by self‐operated food boxes for white‐fronted lemurs (Eulemur fulvus albifrons) in the Masoala exhibit of the Zurich Zoo
Authors: Sommerfeld Ralf , Bauert Martin , Hillmann Edna , Stauffacher Markus
Published: December 2005

In the new Masoala exhibit of the Zurich Zoo four self‐operated food boxes were installed to encourage arboreal behavior and higher activity levels, and to increase the attractiveness to visitors of a group of three white‐fronted lemurs (Eulemur fulvus albifrons) and one Alaotran gentle lemur (Hapalemur griseus alaotrensis). Data obtained by direct observations with and without food boxes present were compared. In addition, visitors were surveyed to investigate attractiveness of the lemurs. Overall activity and locomotor behavior increased due to food box presentation. Furthermore, the visitor survey documented that the lemurs were spotted more often in trees when the food boxes were present. Because behavior patterns of the subjects approached natural levels with food boxes, the presentation of self‐operated food boxes seems a valuable tool to improve the captive environment of lemurs. Zoo Biol 0:1–10, 2005. © 2005 Wiley‐Liss, Inc.
Kinetic formulation for heterogeneous scalar conservation laws
Authors: Dalibard Anne-Laure
Published: December 2005

This article is concerned with the study of entropy solutions of the scalar conservation law

\partial _{t}u + \mathrm{div}_{x}A(x,u) = 0

. The main novelty of our work lies in the fact that the flux

A

is allowed to depend on the space variable

x

. We introduce a kinetic formulation for this equation, proven to be equivalent to the usual entropy inequalities. We check the existence and uniqueness of weak

L^{1}

solutions of the scalar law.

On étudie ici les solutions entropiques de lois de conservation scalaires hétérogènes

\partial _{t}u + \mathrm{div}_{x}A(x,u) = 0

. L'apport principal de notre étude vient de la forme plus générale du flux

A

, qui dépend explicitement de la variable d'espace

x

. On commence par introduire une formulation cinétique de la loi de conservation, dont on montre qu'elle est équivalente aux inégalités entropiques habituelles. On vérifie ensuite l'existence et l'unicité de solutions faibles

L^{1}

de la loi de conservation.
An inverse problem in the economic theory of demand
Authors: Ekeland Ivar , Djitté Ngalla
Published: December 2005

Given an exchange economy consisting of

k

consumers, there is an associated collective demand function, which is the sum of the individual demand functions. It maps the price system

p

to a goods bundle

x(p)

. Conversely, given a map

p\rightarrow x(p)

, it is natural to ask whether it is the collective demand function of a market economy. We answer that question in the case when

k

is less than the number of goods

n

. The proof relies on finding convex solutions to a strongly nonlinear system of partial differential equations.

La fonction de demande agrégée d'une société composée de

k

individus résulte de la sommation de

k

fonctions de demandes individuelles. Elle fait correspondre à un système de prix

p

, un vecteur de biens

x(p)

. Inversement, étant donnée une fonction

p\rightarrow x(p)

, est-elle une fonction de demande agrégée ? Nous apporterons une réponse à cette question dans le cas où il y a moins de consommateurs que de biens.
MLP accumulation and remodelling in the infarcted rat heart
Authors: Wilding James R. , Lygate Craig A. , Davies Kay E. , Neubauer Stefan , Clarke Kieran
Published: December 2005

Mutation of cytoskeletal protein genes results in abnormal protein function and causes cardiomyopathy. We hypothesised that cardiac levels of cytoskeletal proteins, such as dystrophin, desmin and muscle LIM protein (MLP), would be altered during remodelling caused by myocardial infarction (MI). We measured left‐ventricular morphology, function and cytoskeletal protein levels 10 weeks after coronary artery ligation or sham operation in male Wistar rats. Two‐dimensional echocardiography revealed significant impairment of systolic function and decreased ejection fraction in infarcted hearts compared with sham (47±5% versus 73±4%), commensurate with the development of heart failure. Western blotting was used to measure levels of β‐myosin heavy chain (β‐MyHC), a marker of hypertrophy, and levels of dystrophin, desmin, MLP, β‐tubulin, utrophin and syncoilin, using GAPDH for normalization. Relative to shams, β‐MyHC and MLP levels were increased 1.9‐fold and 1.7‐fold, respectively, in infarcted rat hearts, whereas the levels of other cytoskeletal proteins were unchanged. Both MLP and desmin protein levels correlated negatively with ejection fraction, with the strongest relation between MLP and ejection fraction (r=−0.95, n=13, p<0.0001). This work suggests that MLP may play an important compensatory role in cardiac remodelling following MI.
Colocalization of serotonin and substance P in the postnatal rat trigeminal motor nucleus and its surroundings
Authors: Nakamura Masaaki , Yasuda Kouichi , Hasumi‐Nakayama Yoko , Sugiura Maki , Tomita Ikuo , Mori Ryota , Tanaka Susumu , Furusawa Kiyofumi
Published: December 2005

Trigeminal motoneurons are involved in a variety of oral motor activities, including mastication and breathing, which must be adapted to postnatal environmental change. Serotonin has both an excitatory and an inhibitory effect on trigeminal motor function, whereas substance P has mainly an excitatory effect. In the present study, we measured the density of serotonin‐ and substance P‐immunoreactive nerve terminals in the trigeminal motor nucleus and the area 300 μm surrounding it in rats from embryonic day 19 to postnatal day 70. The density of these terminals gradually increased from embryonic day 19 to postnatal day 7 and decreased thereafter. The density was greatest in the ventromedial subnucleus of the trigeminal motor nucleus at embryonic day 19 and postnatal day 0 and in the area 300 μm surrounding trigeminal motor nucleus at postnatal day 4 and older. Two‐color fluorescence immunohistochemistry was used to identify nerve processes immunoreactive for both substance P and serotonin. Approximately, 90% of serotonergic terminals also contained substance P at all ages examined, which suggests that the physiological function of terminals in which these neurotransmitters are colocalized is similar throughout development.
On the effect of inertia and history forces on the slow motion of a spherical solid or gaseous inclusion in a solid-body rotation flow
Authors: CANDELIER FABIEN , ANGILELLA JEAN-RÉGIS , SOUHAR MOHAMED
Published: December 2005

The motion of a spherical inclusion released in a vertical solid-body rotation flow is investigated theoretically and experimentally. Solid spheres and bubbles are considered. The particle Reynolds number, the Taylor number, the Weber number and the capillary number are smaller than unity. The motion equations of the inclusion are obtained by revisiting the hydrodynamic equations. The axial (vertical) motion and the horizontal motion are uncoupled, even though they are sensitive to the rotation rate of the flow. Analytical solutions of the particle motion equation are compared to experimental results obtained by releasing a particle in a rotating tank filled with silicone oil. For solid spheres and bubbles, both the terminal velocity and the particle ejection rate (or trapping rate) predicted by the theory agree with experiments, without any empirical adjustment. In particular, the experimental device enables us to check the validity of various theories involving solid or gaseous inclusions with or without inertia or history effects. It is observed that the mobility tensor obtained by writing the fluid motion equations in the rotating frame accurately predicts the horizontal particle trajectory, like the Boussinesq-Basset equation obtained by writing the fluid motion equations in the non-rotating frame and neglecting the horizontal contribution of inertia effects.
Retraction dynamics of aqueous drops upon impact on non-wetting surfaces
Authors: BARTOLO DENIS , JOSSERAND CHRISTOPHE , BONN DANIEL
Published: December 2005

We study the impact and subsequent retraction of liquid droplets upon high-speed impact on hydrophobic surfaces. Extensive experiments show that the drop retraction rate is a material constant and does not depend on the impact velocity. We show that on increasing the Ohnesorge number, $\Oh\,{=}\,\eta/\sqrt{\rho R_{\rm I} \gamma}$, the retraction, i.e. dewetting, dynamics crosses from a capillary-inertial regime to a capillary-viscous regime. We rationalize the experimental observations by a simple but robust semi-quantitative model for the solid-liquid contact line dynamics inspired by the standard theories for thin-film dewetting.