bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-Dose Dexamethasone Facilitates Extubation Among Chronically Ventilator-Dependent Infants: A Multicenter, International, Randomized, Controlled Trial
Authors: Doyle Lex W. , Davis Peter G. , Morley Colin J. , McPhee Andy , Carlin John B. ,   and the DART Study Investigators
Published: January 2006

OBJECTIVE. Postnatal corticosteroid therapy is controversial. The aim of this study was to determine the short-term effects of low-dose dexamethasone treatment among chronically ventilator-dependent neonates.

METHODS. Very preterm (gestational age: <28 weeks) or extremely low birth weight (birth weight: <1000 g) infants who were ventilator dependent after the first 1 week of life were eligible and were assigned randomly to receive masked dexamethasone (0.89 mg/kg over 10 days) or saline placebo. Data on ventilator and oxygen requirements and deaths were recorded.

RESULTS. Seventy infants were recruited from 11 centers, at a median age of 23 days. More infants were extubated successfully by 10 days of treatment in the dexamethasone group (60%, 21 of 35 patients) than in the control group (12%, 4 of 34 patients) (odds ratio [OR]: 11.2; 95% confidence interval [CI]: 3.2–39.0). Ventilator and oxygen requirements improved substantially, and the duration of intubation was shorter. There was little evidence for a reduction in either the mortality rate (dexamethasone group: 11%; control group: 20%; OR: 0.52; 95% CI: 0.14–1.95) or the rate of oxygen dependence at 36 weeks (dexamethasone group: 85%; control group: 91%; OR: 0.58; 95% CI: 0.13–2.66). There were no obvious effects of low-dose dexamethasone on blood glucose concentrations, blood pressure, or other complications. No infant experienced intestinal perforation.

CONCLUSIONS. Low-dose dexamethasone treatment after the first 1 week of life clearly facilitates extubation and shortens the duration of intubation among ventilator-dependent, very preterm/extremely low birth weight infants, without any obvious short-term complications. Combined with recent evidence that infants at very high risk of bronchopulmonary dysplasia may benefit in the long term, our study reopens debate regarding the role of low-dose, late postnatal, corticosteroid therapy.
Formation and morphology of Kurnakov type D022compound in disordered face-centered cubic γ–(Ni, Fe) matrix alloys
Authors: Suzuki Akane , Takeyama Masao
Published: January 2006

Formation and morphology of D022compound Ni3V in γ face-centered cubic (fcc) matrix phase were investigated to understand fundamentals for controlling microstructure of alloys strengthened by Kurnakov-type geometrically close-packed (GCP) intermetallics. The D022phase with plate-shaped morphology coherently precipitates in the γ + D022two-phase region above theT0line in Ni–V binary alloys. Due to the negative and positive lattice misfits along thea-axis and thec-axis of D022(δa< 0 < δc), an invariant line exists between the two phases, and the morphology of D022phase is changeable by controlling the two factors; the misfit strain ratio δc/δais a decisive factor to determine the habit plane defined by the invariant line and one of thea-axes of D022, whereas the magnitude of |δa| is responsible for the shape of D022phase with either prism or plate. These findings were extended to Ni–Fe–Nb–V system by partial replacement of Ni and V with Fe and Nb, respectively.
Instrumented Vickers microindentation of alumina-based materials
Authors: Bueno S. , Baudin C.
Published: January 2006

The adequacy of instrumented Vickers depth-sensing microindentation to determine Young's modulus of alumina-based ceramics was analyzed. Monophase alumina materials and alumina + 10 vol% aluminium titanate composites, with different microstructures, were tested to determine the effect of microcracking. The load–depth penetration of the indenter curves together with the observation of the imprints by scanning electron microscopy were used to analyze the behavior of the materials. Maximum stiffness was determined from the derivatives of the load-depth curves during unloading. The areas of the imprints measured optically were more representative of the behavior of the materials than the areas calculated from depth-penetration measurements. The formation of microcracks affected the shape of the unloading portion of the curves. Significant differences between the values of Young's modulus determined for different materials and definite relationships between the microstructural parameters of the materials and the Young's modulus were found.
Comments on “Comment on the determination of mechanical properties from the energy dissipated during indentation” by J. Malzbender [J. Mater. Res. 20, 1090 (2005)]
Authors: Alkorta J. , Martínez–Esnaola J.M. , Sevillano J. Gil , Malzbender Jürgen
Published: January 2006

Based on a comparison of relationships between energy dissipated during indentation and the ratio of hardness to reduced elastic modulus, Malzbender has recently proposed a procedure to determine both hardness and elastic modulus from a single loading–unloading indentation curve. However, a more accurate analysis of this relationship shows that, in fact, it suffers from the same limitations as the well-known Oliver and Pharr's method; i.e., in general, the true projected imprint area has to be measured in addition to the load–penetration curve or at least two such curves obtained with different indenter geometries are to be used to unequivocally determine the hardness and the elastic modulus of a material.
Electronically stimulated degradation of silicon solar cells
Authors: Schmidt J. , Bothe K. , Macdonald D. , Adey J. , Jones R. , Palmer D.W.
Published: January 2006

Carrier lifetime degradation in crystalline silicon solar cells under illumination with white light is a frequently observed phenomenon. Two main causes of such degradation effects have been identified in the past, both of them being electronically driven and both related to the most common acceptor element, boron, in silicon: (i) the dissociation of iron-boron pairs and (ii) the formation of recombination-active boron-oxygen complexes. While the first mechanism is particularly relevant in metal-contaminated solar-grade multicrystalline silicon materials, the latter process is important in monocrystalline Czochralski-grown silicon, rich in oxygen. This paper starts with a short review of the characteristic features of the two processes. We then briefly address the effect of iron-boron dissociation on solar cell parameters. Regarding the boron-oxygen-related degradation, the current status of the physical understanding of the defect formation process and the defect structure are presented. Finally, we discuss different strategies for effectively avoiding the degradation.
Synthesis and characterization of organic–inorganic poly(3,4-ethylenedioxythiophene)/MoS2 nanocomposite via in situ oxidative polymerization
Authors: Murugan A. Vadivel , Quintin Mathieu , Delville Marie-Helene , Campet Guy , Viswanath Annamraju Kasi , Gopinath Chinnakonda S. , Vijayamohanan K.
Published: January 2006

Here we demonstrate the synthesis of a new type of layered poly(3,4-ethylenedioxy- thiophene) (PEDOT)/MoS2 nanocomposite via flocculation of delaminated MoS2 with subsequent in situ oxidative polymerization of 3,4-ethylenedioxythiophene. The resulting nanocomposite was characterized by Fourier transform infrared spectroscopy, powder x-ray diffraction, x-ray photoelectron spectroscopy, thermal analysis, transmission electron microscopy, and four-probe electrical conductivity measurements with respect to temperature. X-ray diffraction results indicated that the exfoliated MoS2 and PEDOT are restacked to produce a novel nanoscale composite material containing alternate nanoribbons of PEDOT in between MoS2 with a basal distance of ∼1.38 nm. The nanocomposite, which could be used as a cathode material for small power rechargeable lithium batteries, has also been demonstrated by the electrochemical insertion of lithium into the PEDOT/MoS2 nanocomposite, where a significant enhancement in the discharge capacity is observed, compared to that of respective pristine molybdenum disulfide.
On the determination of reduced Young's modulus and hardness of elastoplastic materials using a single sharp indenter
Authors: Cao Yan Ping , Qian Xiu Qing , Lu Jian
Published: January 2006

In this work, we analyzed the theoretical errors of reduced Young's modulus and hardness of materials provided by single sharp indenter algorithms. According to the analysis, two conclusions can be drawn. First, various methods that use only the indentation loading and unloading curves from a single sharp indenter and omit the effect of the strain hardening exponent own the same widths of the theoretical error bands defined here. They are WEb for reduced Young's modulus and WHb for hardness. Second, the upper-bounds, BUE and BUH, and lower-bounds, BLE and BLH, of theoretical errors of the measured reduced Young's modulus and hardness might be different for different methods. These conclusions, on the one hand, are relevant to the evaluation of various established single sharp indenter algorithms. On the other hand, they provide useful information (i.e., to optimize the theoretical error bounds) for correcting an established method and the development of new single sharp indenter algorithms. According to the conclusions, an energy-based method has been devised to determine reduced Young's modulus and hardness of materials from nanoindentation tests using a standard Berkovich or Vickers indenter (equivalent to a 70.3° cone). It has been shown that the present method owns the reasonable theoretical error bounds and can provide stable results in the presence of data errors.
Structural development and electronic properties of hot filament low pressure chemical vapor deposited fluorocarbon polymer films
Authors: Rastogi A.C. , Desu S.B.
Published: January 2006

Fluorocarbon polymer films in the poly(tetrafluoroethylene) (PTFE)-like structure are formed by a low-pressure chemical vapor deposition technique using the hot filament excitation of the gaseous C3F6O precursor. The filament and substrate temperatures were found to influence the structure of the deposited films. Infrared absorption and electron spectroscopy studies reveal that a PTFE-like (CF2)2n linear molecular chain structure evolves by an adsorption driven nucleation and CF2 polymerization process in the films deposited with low (450 °C) filament and high (70 °C) substrate temperatures. The films formed at a low substrate temperature (–165 °C) show a higher concentration of CF and C–CF bond defects and shorter (CF2)2n chains. A high (8–10 at.%) oxygen concentration in the films deposited at 600 °C filament temperature is attributed to the reaction of the (CF2)2n chains with COF and peroxyradicals arising from the dissociation of CF3C(O)F and affects the thermal stability of the films. Such reactions are not involved in the film growth at a low (450 °C) filament temperature. These films have much lower (<2 at.%) bonded oxygen content. The films having an ordered (CF2)2n chain structure formed at 70 °C are characterized by low leakage currents ∼7 × 10−11 A cm−2 at 0.1 MV cm−1 field. In comparison, high leakage currents ∼1 × 10−8 A cm−2 are observed for the films having a higher concentration of C–F and C–CF bonds.
Consolidation and properties of Gd0.1Ce0.9O1.95 nanoparticles for solid-oxide fuel cell electrolytes
Authors: Tok A.I.Y. , Luo L.H. , Boey F.Y.C. , Woodhead J.L.
Published: January 2006

Gd-doped ceria solid solutions have been recognized to be leading electrolytes for use in intermediate-temperature fuel cells. In this paper, the preparation, solubility, and densification of Gd0.1Ce0.9O1.95 ceramics derived from carbonate co-precipitation are reported. The dissolution of Gd2O3 in CeO2 lattice was identified to be completed during the co-precipitation process by studying the lattice parameter as a function of temperature. After calcination at 800 °C for 2 h, the nano-sized Gd0.1Ce0.9O1.95 powder (∼33 nm) with a nearly spherical shape and a narrow particle-size distribution was obtained. This calcined powder has high sinterability and maximum densification rate at ∼1000 °C. Sintering at 1300 °C for 4 h yielded over 97% relative density with near maximum. The grain size increased with increases in sintering temperature. The ionic conductivity of these pellets was tested by alternating current impedance spectroscopy to elucidate the contribution of intragranular and intergranular conductivity to the total ionic conductivity. It was found that sintering temperature does not affect intragranular conductivity, though intergranular conductivity was strongly influenced by grain size, grain boundary area, and relativity density. This pellet sintered at 1500 °C for 4 h showed a high ionic conductivity of 5.90 × 10−2 s/cm when measured at 750 °C. The characterization and structural evaluation of the as-received powders were carried out using x-ray diffraction, transmission electron microscopy, Brunauer–Emmett–Teller, and dilatometer and impedance analysis.
Low-temperature polymer precursor-based synthesis of nanocrystalline particles of lanthanum calcium manganese oxide (La0.67Ca0.33MnO3) with enhanced ferromagnetic transition temperature
Authors: Shankar K. Shantha , Raychaudhuri A.K.
Published: January 2006

We report a simple modified polymeric precursor route for the synthesis of highly crystalline and homogenous nanoparticles of lanthanum calcium manganese oxide (LCMO). The LCMO phase formation was studied by thermal analysis, x-ray powder diffraction, and infrared spectroscopy at different stages of heating. These nanocrystallites (average particle size of 30 nm) possess ferromagnetic–paramagnetic transition temperature (Tc) of 300 K, nearly 50 K higher than that of a single crystal. The Rietveld analysis of the powder x-ray diffraction data of the nanopowders reveals significant lattice contraction and reduction in unit cell anisotropy-these structural changes are correlated to the enhancement in Tc.
Electrochemical corrosion study of Pb-free solders
Authors: Wu B.Y. , Chan Y.C. , Alam M.O. , Jillek W.
Published: January 2006

This paper presents an investigation on the corrosion behavior of five solders by means of polarization and electrochemical impedance spectroscopy (EIS) measurements. The Sn–9Zn and Sn–8Zn–3Bi solder, in comparison with the Sn–3.5Ag–0.5Cu and Sn–3.5Ag–0.5Cu–9In solder, were tested in 3.5 wt% NaCl solution and 0.1 wt% adipic acid solution, respectively. The Sn–37Pb solder was for reference in this work. The polarization curves indicated that the Sn–9Zn and Sn–8Zn–3Bi solder showed the worst corrosion resistance both in the salt and acid solutions, in terms of corrosion-current density, corrosion potential, linear polarization resistance, and passivation-current density. Meanwhile, the Sn–3.5Ag–0.5Cu solder remained the best corrosion characteristics in both solutions. It was found that due to microstructure alteration, Bi additive to the Sn–9Zn solder improved the corrosion behavior in the salt solution, whereas decreased that in the acid solution. However, the additive of In degraded the Sn–3.5Ag–0.5Cu solder in both solutions. The EIS results agreed well with the noble sequence of the five solders subjected to the two solutions with polarization. The equivalent circuits were also determined. Nevertheless, the four Pb-free solders exhibited acceptable corrosion properties since there was not much difference of key corrosion parameters between them and the Sn–37Pb solder.
Effect of epidermal growth factor and prostaglandin on the expression of aromatase (CYP19) in human adrenocortical carcinoma cell line NCI-H295R cells
Authors: Watanabe Masatada , Noda Mariko , Nakajin Shizuo
Published: January 2006

We investigated the effects of epidermal growth factor (EGF) and prostaglandins (PG) on the expression of aromatase (CYP19) in human adrenocortical carcinoma cell line NCI-H295R cells. EGF significantly increased aromatase activity and CYP19 gene transcript in NCI-H295R cells. Exon PII was selected from among several tissue-specific exon I regions. Promoter II that abuts on exon PII was activated by EGF. PGE2 also significantly increased aromatase activity, CYP19 gene transcript, and promoter II activity. The results of experiments using protein kinase (PK) inhibitors suggest that the cAMP–PKA signaling pathway is involved in the up-regulation of aromatase expression by EGF. PGE2 activated promoter II activity in 4 h, while12 h was required for its activation by EGF. In addition, PGE2 was secreted from NCI-H295R cells in response to EGF. Selective agonists for prostaglandin receptors EP1 and EP2 significantly increased aromatase activity, which was decreased by the corresponding antagonists. Finally, antagonists for EP1 and EP2 inhibited the up-regulation of aromatase expression following EGF. These results suggest that PGE2 secondarily acts as an autocrine signal in the up-regulation of aromatase expression by EGF in NCI-H295R cells.
Antioxidant defense system during endometrial receptivity in the guinea pig: effect of ormeloxifene, a selective estrogen receptor modulator
Authors: Makker A , Bansode F W , Srivastava V M L , Singh M M
Published: January 2006

The role of the antioxidant defense system during endometrial receptivity, a phenomenon crucial for implantation and decidualization, and the effect of ormeloxifene, a selective estrogen receptor modulator, were investigated in the guinea pig, a laboratory mammalian species with interstitial implantation and a long functional luteal phase during each estrous cycle. A sharp rise in the activity of superoxide dismutase (SOD) in both antimesometrial (AM) and mesometrial segments and peroxidase in the AM segment of the uterus was observed on the day of maximal endometrial receptivity. Pretreatment with ormeloxifene resulted in loss of endometrial responsiveness, as evidenced by inhibition of trauma-induced decidualization and the activity of ornithine decarboxylase, a marker of tissue growth and repair. This was associated with a decrease in SOD and estradiol dehydrogenase activities, with corresponding increases in estrone dehydrogenase activity and stimulation of uterine luminal epithelial cell height and a distension of the uterine and glandular lumen. A decrease in peroxidase activity was observed only in the AM segment of the uterus on the imminent day of maximal endometrial receptivity. No effect on peripheral plasma progesterone concentration or surface ultrastructure was evident. These findings demonstrate that SOD plays an important role, with peroxidase having a supplementary role, in the first line of defense against superoxide anion radicals during the period of maximal endometrial receptivity in the guinea pig. Inhibition of endometrial receptivity and decidualization by ormeloxifene administered during the pre-receptive phase appears to be due to a depressed antioxidant defense system via dysregulation of redox-sensitive signaling, resulting in altered cellular toxicity due to increased superoxide radicals, and might contribute to the contraceptive action of ormeloxifene. This might be related to its estrogen antagonistic activity and/or decreased bioavailability of estradiol at a cellular level due to its increased metabolism to biologically less-active estrone via activation of estradiol-17 beta-hydroxysteroid dehydrogenase and suppression of estrone-17 beta-hydroxysteroid dehydrogenase.
Evaluating the CROPGRO–Soybean Model Ability to Simulate Photosynthesis Response to Carbon Dioxide Levels
Authors: Alagarswamy G. , Boote K. J. , Allen L. H. , Jones J. W.
Published: January 2006

Atmospheric carbon dioxide concentration [CO2] will increase in the future and will affect global climate and ecosystem productivity. Crop models used in past assessments of climate change effect on ecosystem productivity have not been adequately tested for the ability to simulate ecosystem responses to [CO2]. Our objective was to evaluate the ability of the default CROPGRO–Soybean model to predict the responses of net leaf photosynthesis (A) and canopy photosynthesis (Acan) to photosynthetic photon flux (PPF) at different [CO2]. We also compared the default leaf photosynthesis equations in CROPGRO with the full Farquhar equations for ability to predict the response of A to [CO2]. Simulated and observed A and Acan were light saturated at 800 μmol m−2 s−1. PPF at ambient [CO2] but did not light saturate at PPF >1100 μmol m−2 s−1 at elevated [CO2]. Observed and simulated A responded asymptotically to increasing intercellular [CO2]. The CROPGRO default photosynthesis equations and the Farquhar equations simulated A equally well at all [CO2]. Doubled [CO2] increased simulated A by 52% and Acan by 42%; these values are close to the increases of 39 to 48% for A and 59% for Acan reported in the literature. Root mean square errors for simulated A and Acan were low, and Willmott's index of agreement ranged from 0.86 to 0.99, confirming that the CROPGRO model with default photosynthesis equations can be used to evaluate potential effects of [CO2] on soybean photosynthesis and productivity.
The Effect of a Baler Chopping System on Fermentation and Losses of Wrapped Big Bales of Alfalfa
Authors: Borreani Giorgio , Tabacco Ernesto
Published: January 2006

The improvement of wrapped big bale silage quality by increasing bale densities should be an important target. The objectives of this research were to evaluate the effects of the use of a cutting system (15 knives spaced 93 mm apart) installed behind the windrow pickup of a fixed chamber round baler. Three field trials were conducted near Turin, Italy (44°50′ N, 7°40′ E) by ensiling wrapped round bale of first‐ and second‐cutting alfalfa (Medicago sativa L.) at different dry matter (DM) concentrations. The DM and crude protein (CP) losses at baling, forage mean particle length, wet and dry bale weights, bale density, fermentation pattern, and the conservation losses were evaluated. The DM losses at baling ranged from 0.5 to 2.0% and from 0.7 to 4.7% of DM yield at cutting for unchopped and chopped treatments, respectively. The chopping system increased the percentage of stems shorter than 10 cm from 14 to 38% on a DM basis. Chopping increased DM bale density by about 4% in all the trials. After 140 d of conservation the final fermentation quality of silages was not consistently improved by chopping.
Soil and Herbicide Properties Influenced Mobility of Atrazine, Metolachlor, and Primisulfuron‐Methyl in Field Lysimeters
Authors: Weber Jerome B. , Taylor K. Allan , Wilkerson Gail G.
Published: January 2006

Understanding herbicide mobility in soils is necessary to prevent groundwater contamination. We studied the mass balance distribution of three14C‐labeled herbicides (atrazine, metolachlor, and primisulfuron‐methyl) in four soils (Dothan, Portsmouth, Rion, and Wagram) 128 d after application to soil column field lysimeters. Analyses were made of surface soil, subsoil, and leachate samples, and metabolites were identified in surface soil and leachate. Our objectives were to examine, measure, and correlate the leaching patterns of the chemicals and correlate their leaching characteristics with the physicochemical properties of the soils. Metolachlor was the most mobile herbicide as indicated by the retardation factor (Rf) (Rf= 0.35 in 1992 and 0.17 in 1993), followed by atrazine (Rf= 0.19 in 1992 and 0.09 in 1993) and primisulfuron‐methyl (Rf= 0.15 in 1992 and 0.12 in 1993). Herbicide mobility (Rf) was related to leachate volume collected from the four soils, herbicide aqueous solubility, and longevity of the chemicals. The herbicides were of greatest mobility in Rion and Wagram soils and of lowest mobility in Portsmouth and Dothan soils. Soil factors affected the weakly basic atrazine differently than the nonionizable metolachlor or the weakly acidic primisulfuron‐methyl. Volatility losses of the herbicides were inversely related to longevity (disappearance time in the field (DT50) of the compounds and to humic matter contents of the soils. Carbon‐14 herbicide in the subsoil and in the leachate was correlated with herbicide mobility (Rf), total leachate volume, and 50% disappearance time values. Herbicide mobility was in agreement with predictability using a simple decision‐aid model.
Fertilizer Nitrogen Efficiency in Durum Wheat under Rainfed Mediterranean Conditions: Effect of Split Application
Authors: López‐Bellido Luis , López‐Bellido Rafael J. , López‐Bellido Francisco J.
Published: January 2006

Efficient N fertilizer management is critical for the economic production of wheat and the long‐term protection of environmental quality. A 3‐yr field experiment on a rainfed Vertisol was designed to study the effects of N fertilizer timing on the efficiency of N in durum wheat (Triticum turgidum L. var. durum Desf.). A single rate of 150 kg N ha−1 was used with different fractions being applied at planting, tillering, and stem elongation. A 15N experiment was also conducted within the main experiment area, with microplots, to quantify N uptake from fertilizer and soil. Mean wheat recovery of N fertilizer ranged from 12.7% when applied at sowing to 41.6% when applied as a topdressing at the beginning of stem elongation. The mean annual contribution of soil residual N and mineralization was 167 kg N ha−1, representing a considerable proportion of total wheat N uptake—ranging from 80.4% when N fertilizer was applied in the fall to 56.3% when it was applied at stem elongation. This would account for the poor and inconsistent response of grain yield and N efficiency indices, and for the importance of soil N in Vertisols for predicting wheat N fertilizer requirements, due to the carryover effect. It is recommended that N fertilizer be applied mainly as a topdressing in durum wheat, between tillering and stem elongation, to enhance crop N use efficiency (NUE) and reduce losses through leaching and runoff.
Nitrogen Partitioning and Estimates of Degradable Intake Protein in Wilting Orchardgrass and Bermudagrass Hays Damaged by Simulated Rainfall
Authors: Scarbrough D. A. , Coblentz W. K. , Ogden R. K. , Turner J. E. , Humphry J. B. , Coffey K. P. , Daniel T. C. , Sauer T. J. , Jennings J. A. , Kellogg D. W.
Published: January 2006

This study investigated the effects of simulated rainfall on N partitioning and concentrations of degradable (DIP) or undegradable (UIP) intake protein for wilting orchardgrass (Dactylis glomerata L.) and bermudagrass [Cynodon dactylon (L.) Pers.] hays. Orchardgrass forage was wilted to 674, 153, or 41 g kg−1 of moisture (WET‐O, IDEAL‐O, and DRY‐O, respectively) in the field before applying the simulated rainfall (0, 13, 25, 38, 51, 64, or 76 mm). For WET‐O, DIP (g kg−1 crude protein [CP]) increased cubically (P = 0.020) with simulated rainfall, but the overall range of response was small (653–673 g kg−1 CP). Estimates of DIP (g kg−1 CP) for IDEAL‐O and DRY‐O decreased by 46 and 25 g kg−1 CP, respectively, between the 0‐ and 76‐mm rainfall increments; for IDEAL‐O, these decreases occurred in a linear (P < 0.0001) pattern, whereas quadratic (P = 0.009) and linear (P = 0.029) effects were observed for DRY‐O. Bermudagrass forage was field wilted to 761, 400, or 130 g kg−1 of moisture (WET‐B, MID‐B, and IDEAL‐B, respectively) and evaluated similarly. For WET‐B and MID‐B, DIP (g kg−1 CP) was not affected (P > 0.05) by simulated rainfall. In contrast, quartic (P = 0.019) and linear (P = 0.002) effects were observed for IDEAL‐B, but these responses were confined primarily to changes between the undamaged (0‐mm) control and the initial 13‐mm rainfall increment. On a practical basis, concentrations of DIP were, at most, altered only moderately in response to simulated rainfall and relatively little when forages were still too wet to bale.
Nitrogen and Tillage Effects on Irrigated Continuous Corn Yields
Authors: Halvorson Ardell D. , Mosier Arvin R. , Reule Curtis A. , Bausch Walter C.
Published: January 2006

A no‐till (NT) production system has potential to reduce soil erosion, fossil fuel consumption, and greenhouse gas emissions compared with a conventional till (CT) system. Nitrogen fertilization (four to six N rates) and tillage system (CT and NT) effects on irrigated, continuous corn (Zea mays L.) yields were evaluated for 5 yr on a clay loam soil to determine the viability of the NT system and N needs for optimum yield. Corn in both NT and CT systems responded similarly to available N supply. Grain yields were significantly increased by N fertilization in both tillage systems, with a 16% higher average maximum yield in the CT than in the NT system. Grain yields were near maximum with an available N (soil + fertilizer N) level of 276 and 268 kg N ha−1 in the CT and NT systems, respectively. Nitrogen fertilizer use efficiency (NFUE) averaged 43% over N rates and years for both systems. Total N required to produce 1 Mg of grain at maximum yield averaged 19 and 20 kg N Mg−1 grain for the CT and NT systems, respectively. Corn residue increased with increasing N rate with no difference in residue production between tillage systems. The lower grain yield with NT probably resulted from the slow early spring development and delayed tasseling compared with the CT system as a result of cooler spring soil temperatures in the NT system. No‐till, irrigated, continuous corn production has potential for replacing CT systems in the central Great Plains area, but with reduced yield potential. Current N fertilizer recommendations for CT corn based on yield goal may need to be modified for NT to account for the lower yield potential and slightly higher N requirement.
Mapping Residual Pyrite after a Mine Spill Using Non Co‐Located Spatiotemporal Observations
Authors: Vanderlinden Karl , Ordóñez Rafaela , Polo Maria J. , Giráldez Juan V.
Published: January 2006

Monitoring of soil chemical properties for pollution assessment generally requires destructive soil sampling and results in spatiotemporal datasets where data from different sampling dates are non co‐located. The objective of this study was to assess the spatial distribution of residual pyrite sludge at a reclaimed site, using temporally non co‐located data on pH; soil oxidizable fraction (SOF); and EDTA‐extractable Fe, Zn, and Cu from six different sampling dates over a period of 2 yr. During this period spatially averaged pH and Zn concentrations ranged, respectively, from 4.4 to 6.6 and from 60 to 140 mg kg−1, with minimum pH values of below 2.7. The data were merged into a single dataset for each chemical property after applying a normal score (ns) transform. Normal score pH was significantly negatively correlated with the ns metal concentrations. A principal component analysis (PCA) showed that normal score pH, Zn, and Fe were associated with the residual contamination, while ns Cu, SOF, and elevation were related with historic contamination. The spatial dependence between the properties was found to be scale‐dependent. The best ns estimates were produced by ordinary kriging with an anisotopic variogram model, for the properties related with Principal Component (PC) I, while those associated with PC II were best estimated using simple kriging with varying local means. A classified ns pH map showed that 33% of the study area reached at least once values of below 4 during the 2‐yr period. This part of the area should be excluded to ensure successful revegetation.
Environmental and Production Consequences of Using Alum‐Amended Poultry Litter as a Nutrient Source for Corn
Authors: Warren Jason G. , Phillips Steven B. , Mullins Greg L. , Keahey Dale , Penn Chad J.
Published: January 2006

Field trials were established to compare alum‐treated poultry litter (ATPL), normal poultry litter (NPL), and triple superphosphate (TSP) as fertilizer sources for corn (Zea mays L.) when applied at rates based on current litter management strategies in Virginia. Trials were established in the Costal Plain and Piedmont physiographic regions near Painter and Orange, VA, respectively. Nitrogen‐based applications of ATPL or NPL applied at rates estimated to supply 173 kg of plant‐available nitrogen (PAN) ha−1 resulted in significantly lower grain yields than treatments receiving commercial fertilizer at the same rate in 2000 and 2001 at Painter. These decreases in grain yield at the N‐based application rates were attributed to inadequate N availability, resulting from overestimates of PAN as demonstrated by tissue N concentrations. However, at Orange no treatment effects on grain yield were observed. Applications of ATPL did not affect Al concentrations in corn ear‐leaves at either location. Exchangeable soil Al concentrations were most elevated in treatments receiving only NH4NO3 as an N source. At N‐based application rates, the ATPL resulted in lower Mehlich 1–extractable P (M1‐P) and water‐extractable soil phosphorus (H2O‐P) concentrations compared to the application of NPL. A portion of this reduction could be attributed to lower rates of P applied in the N‐based ATPL treatments. Runoff collected from treatments which received ATPL 2 d before conducting rainfall simulations contained 61 to 71% less dissolved reactive phosphorus (DRP) than treatments receiving NPL. These results show that ATPL may be used as a nutrient source for corn production without significant management alterations. Alum‐treated poultry litter can also reduce the environmental impact of litter applications, primarily through minimizing the P status of soils receiving long‐term applications of litter and reductions in runoff DRP losses shortly after application.
Reduction of Malodorous Compounds from a Treated Swine Anaerobic Lagoon
Authors: Loughrin John H. , Szogi Ariel A. , Vanotti Matias B.
Published: January 2006

There is a need for treatment technologies that can eliminate environmental problems associated with anaerobic lagoons. These technologies must be able to capture nutrients, kill pathogens, and reduce emissions of ammonia and nuisance odors. To meet these needs, a full‐scale wastewater treatment plant was installed as a demonstration project on one of three 4360‐pig (Sus scrofa) production units in a finishing farm in Duplin County, North Carolina. Once the treatment plant was operational, flow of raw manure into the unit's corresponding lagoon was discontinued and the lagoon was used to store treated wastewater. Water quality was monitored in the converted lagoon and in the two conventional lagoons. A gas chromatographic method was developed to measure concentration of five selected malodorous compounds (phenol, p‐cresol, 4‐ethylphenol, indole, and skatole) in liquid lagoon samples. Dramatic improvements in the water quality parameters TKN, NH3–N, solids, COD, and BOD in the converted waste lagoon paralleled reductions in malodorous compounds. Nine months after conversion, identified malodorous compounds in liquid extractions averaged 6.6 and 38.8 ng mL−1 in water from the converted lagoon and the conventional lagoons, respectively. The reduction was particularly marked for p‐cresol, 4‐ethylphenol, and skatole, all of which make important contributions to swine waste odors due to their characteristic odors and low detection thresholds.
Fatty Acid Methyl Ester Analysis to Identify Sources of Soil in Surface Water
Authors: Banowetz Gary M. , Whittaker Gerald W. , Dierksen Karen P. , Azevedo Mark D. , Kennedy Ann C. , Griffith Stephen M. , Steiner Jeffrey J.
Published: January 2006

Efforts to improve land‐use practices to prevent contamination of surface waters with soil are limited by an inability to identify the primary sources of soil present in these waters. We evaluated the utility of fatty acid methyl ester (FAME) profiles of dry reference soils for multivariate statistical classification of soils collected from surface waters adjacent to agricultural production fields and a wooded riparian zone. Trials that compared approaches to concentrate soil from surface water showed that aluminum sulfate precipitation provided comparable yields to that obtained by vacuum filtration and was more suitable for handling large numbers of samples. Fatty acid methyl ester profiles were developed from reference soils collected from contrasting land uses in different seasons to determine whether specific fatty acids would consistently serve as variables in multivariate statistical analyses to permit reliable classification of soils. We used a Bayesian method and an independent iterative process to select appropriate fatty acids and found that variable selection was strongly impacted by the season during which soil was collected. The apparent seasonal variation in the occurrence of marker fatty acids in FAME profiles from reference soils prevented preparation of a standardized set of variables. Nevertheless, accurate classification of soil in surface water was achieved utilizing fatty acid variables identified in seasonally matched reference soils. Correlation analysis of entire chromatograms and subsequent discriminant analyses utilizing a restricted number of fatty acid variables showed that FAME profiles of soils exposed to the aquatic environment still had utility for classification at least 1 wk after submersion.
Fall Fertilization Timing Effects on Nitrate Leaching and Turfgrass Color and Growth
Authors: Mangiafico Salvatore S. , Guillard Karl
Published: January 2006

Fall season fertilization is a widely recommended practice for turfgrass. Fertilizer applied in the fall, however, may be subject to substantial leaching losses. A field study was conducted in Connecticut to determine the timing effects of fall fertilization on nitrate N (NO3−N) leaching, turf color, shoot density, and root mass of a 90% Kentucky bluegrass (Poa pratensisL.), 10% creeping red fescue (Festuca rubraL.) lawn. Treatments consisted of the date of fall fertilization: 15 September, 15 October, 15 November, 15 December, or control which received no fall fertilizer. Percolate water was collected weekly with soil monolith lysimeters. Mean log10NO3−N concentrations in percolate were higher for fall fertilized treatments than for the control. Mean NO3−N mass collected in percolate water was linearly related to the date of fertilizer application, with higher NO3−N loss for later application dates. Applying fall fertilizer improved turf color and density but there were no differences in color or density among applications made between 15 October and 15 December. These findings suggest that the current recommendation of applying N in mid‐ to late November in southern New England may not be compatible with water quality goals.
Specific Conductance and Ionic Characteristics of Farm Canals in the Everglades Agricultural Area
Authors: Chen Ming , Daroub Samira H. , Lang Timothy A. , Diaz Orlando A.
Published: January 2006

Specific conductance in farm canals of the Everglades Agricultural Area (EAA) in south Florida is an important water quality parameter that was categorized as a parameter of concern according to an observed frequency of >5% excursions over the Class III water quality criterion and needed to be addressed as a part of the Everglades Regulatory Program. This study was conducted to evaluate specific conductance in farm canals of the EAA. Specific conductance was monitored at 10 representative farms (a total of 12 pump stations) in the EAA using multi‐parameter water quality data loggers, for periods ranging from 24 to 83 mo. Cation and anion concentrations were also determined. Nonparametric Mann‐Kendall trend analyses and Sen's slope analysis of specific conductance were conducted to determine specific conductance trends. Mean specific conductance ranged from 0.74 to 1.68 dS m−1 and only 2 of the 10 farms were above the State Class III water quality criterion of 1.275 dS m−1 Statistically significant downward trends were observed at 3 of the 10 farms. Determination of ion compositions in grab samples at 8 of the 10 farms indicated that the major ions contributing to the increase in specific conductance in the EAA were Cl−, HCO3−, and Na+ Mean Na/Cl ratios in most of the EAA canals ranged from 0.57 to 0.78, whereas those of SO4/Cl ranged from 0.46 to 0.98. Investigation of historical data and literature indicates that elevated specific conductance in parts of the EAA is a natural phenomenon due to entrapment of connate seawater in the Everglades formation. Sulfur contributes minor increases in specific conductance in the EAA with probable sources from organic soil mineralization, ground water, Lake Okeechobee, and S fertilizers.
A Story-Based Model from Turkey to Foster Preschool Children's Communicative Input and Performance in the Process of Mother Tongue Acquisition
Authors: Kabadayi Abdülkadir
Published: January 2006

It is an undeniable fact that storytelling makes a remarkable contribution to the domains of child development at an early age since it is stated that storytelling is the original form of teaching. Firstly, the contributions and effects of storytelling techniques to the cultural, cognitive, linguistic, socio-emotional and psychological domains of children between three and eight years old are reviewed. Secondly, a story-based model is proposed for preschool teachers to apply effectively in the frame of before-implementing, while-implementing and post-implementing phases in mother tongue acquisition. Lastly, some suggestions are made for preschool teachers to implement the model to foster linguistic, cognitive, social and emotional domains of preschool children effectively in the classroom.
Studying across Race: A Conversation about the Place of Difference in Qualitative Research
Authors: Barclay-McLaughlin Gina , Hatch J. Amos
Published: January 2006

This article is a dialog between colleagues from different races who struggle with the complexities of doing qualitative research with participants who come from backgrounds that do not match their own. Based on transcriptions of extensive audiotaped conversations, the article explores issues related to studying across difference. The discussion is framed by four qualitative research paradigms: post-positivist, constructivist, critical/feminist, and poststructuralist.
Challenging Essentialist Discourses on Children's Self-Identities: ‘The Child’ in Cultural Radicalism and Revolutionary Practices in Sweden in the 1960s and 1970s
Authors: Ohrlander Kajsa
Published: January 2006

This article tries to understand, by using some poststructural tools, practices with children that were performed by a Left action group in Sweden in the 1960s and 1970s. Modernist resistance discourses of enlightenment and liberation from obedience, silence and innocence can be seen as being produced, together with postmodern acts of unfolding and deconstructing a unified and essentialist child subject. It finds those non-essential child subjects created in the unpredictable dramaturgy of happenings and actions, and in the decentred spread of talks, tasks and modes of addressing. It makes the point that by analysing how new discourses of childhood were lived out, acted on and performed rather than found in ideological debates, it is possible to add new understandings of changes in child discourses in the 1970s. The article stresses the open-endedness of those practices, and their relation to the creation of new rooms and spaces. It suggests something of a paradox: that the moving and changing of child subjectivities was produced within practices where collectivity was the priority.
Troubling the Identity of a Researcher: Methodological and Ethical Questions in Cooperating with Teacher-Carers in Norway
Authors: Bae Berit
Published: January 2006

The questions raised in this article have to do with how to take due care of the subjectivity of the persons involved in a research project. My main point is that a researcher's self-reflection on ethical problems is inextricably a part of doing research in early childhood settings, if we want to create knowledge which is valid and takes care of the subjectivity of the persons taking part. Questions concerning ethics and validity thus are intertwined. The article draws from the experiences of being a participant observer and cooperating with preschool teacher-carers in Norwegian preschool day-care centres or nursery schools. The purpose of the article is to draw attention to troubling questions which may arise in all phases of a research project involving practitioners in early childhood settings. The focus is on how reflecting on such questions may challenge the powerful role of the researcher and empower the position of the teacher.
Sticky Fingers, or How to Love a Postmodern Child
Authors: Bunyard Derek
Published: January 2006

This article uses figurations taken from popular culture to explore Donna Haraway's concept of cyborg identities, extending this to include childhood. Starting from her identification of the image of the cyborg as an ironic metaphorical response to capitalism, two negative forms of identity are explored in relation to current technological and sociological imperatives. The first prompts a re-interrogation of the natural, and the second an equivalent questioning of the artificial.
Mechanical and surface properties of membranes prepared from waterborne cationic hydroxyl‐terminated polydimethylsiloxane/polyurethane surfactant‐free micro‐emulsion
Authors: Li Xiaorui , Fei Guiqiang , Wang Haihua
Published: January 2006

With the action of catalyst and cosolvent, a series of hydroxyl‐terminated polydimethylsiloxane (HPMS) based polyurethane (PU) micro‐emulsion were gotten by surfactant‐free copolymerization. They were successfully prepared by reacting isophorone isocyanate, poly(tetramethylene glycol), and HPMS with N‐methyldiethanolamine (MDEA) as chain extender and trimethylolpropane (TMP) as crosslinker. After neutralizing with dimethyl sulfate and inversing the emulsion polymerization with deionized water, a series of microemulsions were obtained. The emulsions were then cast into membranes named as PU–HPMS. The mechanical properties and water absorption of the PU–HPMS were determined and simultaneously the effects of the content of hard segment, solvent, TMP, MDEA, HPMS, and the molecular weight of soft segment were studied. It is noticed that the tensile strength decreased and elongation at break increased in the HPMS/PU when compared with pure PU, which confirm that PU was end‐capped with PDMS. It is also noticed that water absorption increased in the HPMS/PU when compared with pure PU. As HPMS content increased from 0.0 to 25.0 wt %, the surface free energies decreased from 0.3446 to 0.2317 mN/cm and water absorption decreased from 11.2% to 0.14%. The surface free energies of the membranes were decreased by more than 32.76%, which demonstrate that the membrane surfaces have excellent water and oil repellency. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 40–46, 2006