bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of key climatic factors regulating the transport of pesticides in leaching and to tile drains
Authors: Nolan Bernard T , Dubus Igor G , Surdyk Nicolas , Fowler Hayley J , Burton Aidan , Hollis John M , Reichenberger Stefan , Jarvis Nicholas J 
Published: April 2008

AbstractBACKGROUND: Key climatic factors influencing the transport of pesticides to drains and to depth were identified. Climatic characteristics such as the timing of rainfall in relation to pesticide application may be more critical than average annual temperature and rainfall. The fate of three pesticides was simulated in nine contrasting soil types for two seasons, five application dates and six synthetic weather data series using the MACRO model, and predicted cumulative pesticide loads were analysed using statistical methods.RESULTS: Classification trees and Pearson correlations indicated that simulated losses in excess of 75th percentile values (0.046 mg m−2 for leaching, 0.042 mg m−2 for drainage) generally occurred with large rainfall events following autumn application on clay soils, for both leaching and drainage scenarios. The amount and timing of winter rainfall were important factors, whatever the application period, and these interacted strongly with soil texture and pesticide mobility and persistence. Winter rainfall primarily influenced losses of less mobile and more persistent compounds, while short‐term rainfall and temperature controlled leaching of the more mobile pesticides.CONCLUSIONS: Numerous climatic characteristics influenced pesticide loss, including the amount of precipitation as well as the timing of rainfall and extreme events in relation to application date. Information regarding the relative influence of the climatic characteristics evaluated here can support the development of a climatic zonation for European‐scale risk assessment for pesticide fate. Copyright © 2008 Society of Chemical Industry
Application timing and efficacy of alternatives for the insecticidal control of Tipula paludosa Meigen (Diptera: Tipulidae), a new invasive pest of turf in the northeastern United States
Authors: Peck Daniel C , Olmstead Daniel , Morales Anuar 
Published: April 2008

AbstractBACKGROUND: Two invasive crane flies, Tipula paludosa Meigen and Tipula oleracea L. (Diptera: Tipulidae), were detected in New York State for the first time in 2004. Both are damaging pests of turfgrass and other horticultural systems in North America where establishment has already been documented. To develop management recommendations for the Northeast and define opportunities for preventive (autumn) and curative (spring) control, four insecticide trials targeting T. paludosa larvae were conducted over a 2 year period.RESULTS: The most efficacious (≥70% control in both trials) products against early instars in autumn were bifenthrin, carbaryl, chlorantraniliprole, clothianidin and trichlorfon. Results varied for azadirachtin, Beauveria bassiana, cyfluthrin, dinotefuran, imidacloprid, imidacloprid + bifenthrin and indoxacarb. Clothianidin and dinotefuran were most efficacious against fourth instars in spring; results varied for imidacloprid, indoxacarb and trichlorfon.CONCLUSION: Several insecticides offer alternatives for preventive and curative control of T. paludosa, but, because there is little overlap with application windows for scarab larvae pests, management may entail an entirely new insecticide treatment window, implying new economic and environmental burdens to the turfgrass industry. Moreover, curtailing the impact and spread of these invasives may be severely hampered because the best performing alternatives (clothianidin, dinotefuran) are not registered in New York. Copyright © 2008 Society of Chemical Industry
Magnetotransport properties of GaMnAs with ferromagnetic nanodots
Authors: Suh Jooyoung , Chang Joonyeon , Kim Eun Kyu , Sapozhnikov M. V. , Mironov V. L. , Fraerman A. A. 
Published: April 2008

AbstractThe new hybrid device consisting of single array of Co nanodots on top of GaMnAs is presented to explore a new functionality of GaMnAs diluted magnetic semiconductor (DMS). Magnetic state of Co dots was observed by magnetic force microscopy (MFM). Magnetoresistance of pure GaMnAs microbridge strongly depends on the orientation of applied magnetic field. Magnetization reversal of the single domain state definitely affects the longitudinal magnetoresistance of GaMnAs. Inhomogeneous magnetic field induced by Co nanodot is a dominant contribution to the resistance change. This field was regarded to act as an effective potential that may affect the spin polarized carriers in GaMnAs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Diamond: a material for acoustic devices
Authors: Mortet V. , Williams O. A. , Haenen K. 
Published: April 2008

AbstractDiamond has been foreseen to replace silicon for high power, high frequency electronic applications or for devices that operates in harsh environments. However, diamond electronic devices are still in the laboratory stage due to the lack of large substrates and the complexity of diamond doping. On another hand, surface acoustic wave filters based on diamond are commercially available. Diamond is especially suited for acoustic applications because of its exceptional mechanical properties. The other properties of diamond such as bio‐inertness and chemical stability certainly make of diamond a key material for the next generation of acoustic sensors. In this article, we try to detail the interest of diamond films in composite acoustic applications and review the different type of acoustic devices/sensors. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Very low dislocation density, resistive GaN films obtained using transition metal nitride interlayers
Authors: Moram M. A. , Kappers M. J. , Zhang Y. , Barber Z. H. , Humphreys C. J. 
Published: April 2008

AbstractA threading dislocation density (TDD) reduction method for GaN films is described. Thin amorphous layers of Sc, Hf, Nb, Zr and Cr were deposited on MOVPE‐grown GaN‐on‐sapphire templates with a TDD of 5 × 109 cm–2 and annealed in NH3 to form metal nitrides. The ScN layer remained continuous, with a very low pinhole density, while the HfN layer contained a high pinhole density of approximately 3 × 109 cm–2. The NbN and ZrN layers formed oriented holey network structures. The Cr layer did not nitride. Coalesced GaN epilayers grown on the ScN layers had the lowest dislocation density of 3 × 107 cm–2 (un‐coalesced GaN on ScN had TDDs as low as 5 × 106 cm–2). Unlike GaN films grown using multiple SiNx interlayers, which contain a similar proportion of edge and mixed dislocations, the GaN‐on‐ScN layers contain substantially fewer mixed than edge dislocations, a proportion similar to that of the high‐TDD template. The low‐TDD GaN epilayers grown on ScN are also highly electrically resistive. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical polarization of m ‐plane In‐GaN/GaN light‐emitting diodes characterized via confocal microscope
Authors: Masui Hisashi , Yamada Hisashi , Iso Kenji , Hirasawa Hirohiko , Fellows Natalie N. , Speck James S. , Nakamura Shuji , DenBaars Steven P. 
Published: April 2008

AbstractA confocal microscope was applied to characterize near‐field optical polarization of light emission from InGaN‐based light‐emitting diodes prepared on a nonpolar orientation. Detection of stray light was significantly reduced as a result of the confocal technique compared to broad‐area measurements. The confocal measurement required no special sample preparation and obtained data was directly interpretable. A polarization ratio of 0.83 was measured on long‐wavelength emitting devices and was sustained over two orders of magnitude of low current range. Energy shifts and separation of emission peaks for the two polarization components were evaluated to discuss the valence‐band structure. Energy shifts indicated that the topmost band |X 〉 had a heavier effective mass than the lower band |Z 〉. Splitting energy of InGaN was estimated to be 30 meV. Results were consistent with the past reports, thus it was confirmed that the confocal microscope is a valid technique to characterize near‐field optical polarization. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Consultants' forum: should post hoc sample size calculations be done?
Authors: Walters Stephen J 
Published: April 2008

AbstractPre‐study sample size calculations for clinical trial research protocols are now mandatory. When an investigator is designing a study to compare the outcomes of an intervention, an essential step is the calculation of sample sizes that will allow a reasonable chance (power) of detecting a pre‐determined difference (effect size) in the outcome variable, at a given level of statistical significance. Frequently studies will recruit fewer patients than the initial pre‐study sample size calculation suggested. Investigators are faced with the fact that their study may be inadequately powered to detect the pre‐specified treatment effect and the statistical analysis of the collected outcome data may or may not report a statistically significant result. If the data produces a “non‐statistically significant result” then investigators are frequently tempted to ask the question “Given the actual final study size, what is the power of the study, now, to detect a treatment effect or difference?” The aim of this article is to debate whether or not it is desirable to answer this question and to undertake a power calculation, after the data have been collected and analysed. Copyright © 2008 John Wiley & Sons, Ltd.
Mass spectra of tetrahydroisoquinoline‐fused 1,3,2‐O,N,P‐ and 1,2,3‐O,S,N‐heterocycles: influence of ring size and fusion, of present heteroatoms, substituent effects and of the stereochemistry on fragmentation
Authors: Starke Ines , Schuster Ildikó , Fülöp Ferenc , Kleinpeter Erich 
Published: April 2008

AbstractThe electron ionization (EI) mass spectra of a variety of stereoisomeric tricyclic 1,3,2‐oxazaphosphino[4,3‐a]isoquinolines (1–4), 1,2,3‐oxathiazino[4,3‐a]isoquinoline‐4‐oxides (5–7) and the ‐4,4‐dioxides (8–10) of oxazaphospholo‐ and oxathiazolo[4,3‐a]‐ (11, 12, 15 and 16) and ‐[3,4‐b]isoquinolines (13, 14 and 17) were recorded. Ring size and fusion, the different heteroatoms (P and S) and substituents on the ring systems strongly influence the mass spectra. In addition, mass spectra of the stereoisomers of compounds 1, 2 and 13, 14 revealed stereochemically relevant differences which are not observed for the other pairs of isomers. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of stream hydraulics and other environmental variables on density of Narapa bonettoi (Oligochaeta) in the Paraná River system
Authors: Blettler Martín , Amsler Mario , de Drago Inés Ezcurra , Marchese Mercedes 
Published: April 2008

AbstractHydraulic and substratum conditions have been identified as two stream features which affect the benthic community composition, abundance and distribution. However, little attention has been given to the influence of hydraulic variables in large river beds. The aim of this study was to analyse the incidence of the near‐bottom hydraulic conditions and other environmental variables on the density of Narapa bonettoi (Oligochaeta, Narapidae), a typical and dominant species found in sandy bed rivers of diverse hierarchy of the Paraná River basin. A large amount of existing and available benthic data were used. The highest correlations among N. bonettoi densities and environmental variables were obtained with the hydraulic variables of friction Reynolds number (R*) and shear stress (τ0); the substratum type (sand, silt and clay) and organic matter content. The results show that N. bonettoi density would be related with the hydraulic variables following a ‘bell‐shaped’ tendency, e.g. with the friction Reynolds number, N. bonettoi would have a preference for transition values of turbulence (∼40 < R* < ∼50), which is equivalent to τ0 between ∼0.6 and ∼0.8 kg −2. Densities show a slight decreasing tendency toward the maximum R* values, suggesting that the species does not support a completely developed turbulence (R* > ∼70). Significant but negative correlations were reported in the literature between benthic macroinvertebrates typical of smaller and steeper streams and R* values far beyond the threshold 70 value. N. bonettoi shows a clear preference for a completely sandy substratum and for sand particles sizes around 300 µm. Finally, considering the important role played by the hydraulic variables on the benthic community studied herein, the contagious distribution pattern of N. bonettoi, reported by other authors, would be principally linked with the interactions between current and sediment near the bottom rather than with the mobility of these organisms. Copyright © 2008 John Wiley & Sons, Ltd.
The effect of the Grand Ditch on the abundance of benthic invertebrates in the Colorado River, Rocky Mountain National Park
Authors: Clayton Jordan A. , Westbrook Cherie J. 
Published: April 2008

AbstractWe investigate herein the hypothesis that there is a significant relationship between bed particle mobility and benthic invertebrate abundance in the gravel‐bed channel of the upper Colorado River in Rocky Mountain National Park. A large diversion channel called the Grand Ditch normally diverts a significant portion (∼50%) of the annual snowmelt runoff from the watershed northward out of the basin. In May 2003, a ∼30‐m section of the ditch was breached, contributing substantially to the magnitude and duration of discharge in the Colorado River until the ditch breach was repaired in July of that year. As a result, all grain sizes in the river channel were mobilized, which contrasted sharply with the minimal gravel transport experienced during the exceptional drought of the previous year. Benthic macroinvertebrates were collected in the field using a Surber sampler at the same six locations for both years, and the number of individuals of the orders ephemeroptera (mayflies), plecoptera (stoneflies), trichoptera (caddisflies) and diptera (e.g. chironomids) was counted in the laboratory. The total number of individuals was 240% higher in 2003, and the proportion of mayflies in the samples increased from 25% in 2002 to 40% in 2003. In 2003, samples were also taken immediately upstream and downstream of a large flow obstruction in the channel in order to further isolate the relative importance of sediment transport against other variables affecting the stream habitat. Numbers of individuals for all taxa collected (particularly ephemeroptera and plecoptera) were nearly an order of magnitude higher at the upstream site than at the downstream, protected location. These results have important implications for the ecosystem management of streams within Rocky Mountain National Park and elsewhere. Copyright © 2008 John Wiley & Sons, Ltd.
When does entrepreneurial self‐efficacy enhance versus reduce firm performance?
Authors: Hmieleski Keith M. , Baron Robert A. 
Published: April 2008

AbstractThe entrepreneurial self‐efficacy of lead founders has been generally considered to be a robust predictor of the performance of their firms. Few studies, however, have considered variables that might moderate this relationship. The current study attempts to fill this gap in the literature by examining two possible moderators of the effects of entrepreneurial self‐efficacy on firm performance: dispositional optimism and environmental dynamism. Results indicate that these factors do indeed moderate the effects of entrepreneurial self‐efficacy; in fact, a three‐way interaction between self‐efficacy, optimism, and environmental dynamism was observed with respect to firm performance. Consistent with predictions, in dynamic environments, the effects of high entrepreneurial self‐efficacy on firm performance were positive when combined with moderate optimism, but negative when combined with high optimism. In stable environments, in contrast, the effects of self‐efficacy were relatively weak, and were not moderated by optimism. Overall, results suggest that high self‐efficacy is not always beneficial for entrepreneurs and may, in fact, exert negative effects under some conditions. Copyright © 2008 Strategic Management Society.
A two‐level structural equation model approach for analyzing multivariate longitudinal responses
Authors: Song Xin‐Yuan , Lee Sik‐Yum , Hser Yih‐Ing 
Published: April 2008

AbstractThe analysis of longitudinal data to study changes in variables measured repeatedly over time has received considerable attention in many fields. This paper proposes a two‐level structural equation model for analyzing multivariate longitudinal responses that are mixed continuous and ordered categorical variables. The first‐level model is defined for measures taken at each time point nested within individuals for investigating their characteristics that are changed with time. The second level is defined for individuals to assess their characteristics that are invariant with time. The proposed model accommodates fixed covariates, nonlinear terms of the latent variables, and missing data. A maximum likelihood (ML) approach is developed for the estimation of parameters and model comparison. Results of a simulation study indicate that the performance of the ML estimation is satisfactory. The proposed methodology is applied to a longitudinal study concerning cocaine use. Copyright © 2008 John Wiley & Sons, Ltd.
Nanomosaic Network for the Detection of Proteins Without Direct Electrical Contact
Authors: Gamby Jean , Abid Jean‐Pierre , Tribollet Bernard , Girault Hubert H. 
Published: April 2008

AbstractA nanomosaic network of metallic nanoparticles for the detection of ultralow concentrations of proteins is reported, which uses two planar microelectrodes embedded in a microchip that permit generation of capacitive coupling to the nanomosaic system without the need for direct electrical contact with the channel. By tailoring the microchannel surface using a sandwich configuration of polyethylene terephthalate/gold nanoparticles/poly(L‐lysine), the surface charge can be modified following biomolecular interactions and monitored using a noncontact admittance technique. This nanodevice system behaves like a tunable capacitor and can be employed for the detection of any kind of molecule. The femtomolar detection of an anionic protein, such as β‐lactoglobulin in phosphate‐buffered saline medium, is taken as an example.
Micro‐organism‐Triggered Release of Silver Nanoparticles from Biodegradable Oxide Carriers Allows Preparation of Self‐Sterilizing Polymer Surfaces
Authors: Loher Stefan , Schneider Oliver D. , Maienfisch Tobias , Bokorny Stefan , Stark Wendelin J. 
Published: April 2008

AbstractThe antimicrobial activity of silver has attracted significant research interest and contributes to an exponentially growing use of this noble metal in commodity products. In this investigation, we describe a general approach to increase the antimicrobial activity of a silver‐containing surface by two to three orders of magnitude. The use of 1–2‐nm silver particles decorating the surface of 20–50‐nm carrier particles consisting of a phosphate‐based, biodegradable ceramic allows the triggered release of silver in the presence of a growing microorganism. This effect is based on the organism's requirements for mineral uptake during growth creating a flux of calcium, phosphate, and other ions to the organism. The growing micro‐organism dissolves the carrier containing these nutrients and thereby releases the silver nanoparticles. Further, we demonstrate the rapid self‐sterilization of polymer surfaces containing silver on calcium phosphate nanoparticles using a series of human pathogens. Colony‐forming units (viable bacteria or fungi counts) have been routinely reduced below detection limit and suggest application of these self‐sterilizing surfaces in hospital environments, food and pharmaceutical processing, and personal care.
Unequal tissue expression of proteins from the PA/PAI system, myoma necrosis, and uterus survival after uterine artery occlusion
Authors: Cheng Zhongping , Xie Yan , Dai Hong , Hu Liping , Zhu Yu , Gong Jun 
Published: April 2008

AbstractObjectiveTo further the understanding of the mechanism behind myoma necrosis and uterus survival after uterine artery occlusion.MethodMyomal and myometrial gene transcription and protein expression of tissue plasminogen activator (tPA), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor type 1 (PAI‐1) were investigated in 30 uteri.ResultsCompared with myometrial expression, myomal expression was less for uPA mRNA (1.34% ± 2.18% vs 2.84% ± 2.97%; P < 0.05) and greater for PAI‐1 mRNA (2.67% ± 1.82% vs 1.27% ± 1.99%; P < 0.05), but the difference in tPA mRNA expression was not significant. Accordingly, compared with myometrial expression, myomal expression was less for the uPA protein (P < 0.05) and greater for the PAI‐1 protein (P < 0.05), but the difference in tPA protein was not significant.ConclusionThe PA/PAI system was found to be expressed differently in myomas and the myometrium, which may play a role in uterus survival and myoma necrosis after uterine artery occlusion.
Minimum sampling effort for reliable non-invasive estimations of excretion abundance of Elaphostrongylus cervi L1 in red deer (Cervus elaphus) populations
Authors: Tayce J. , Acevedo P. , Vicente J. , Gortazar C. 
Published: April 2008

AbstractFaecal surveys are commonly used as non-invasive means to evaluate population abundance of animals as well as comparable indexes of prevalence and intensity of diseases between populations, especially macroparasites. While faecal surveys are among one of the simplest means to perform these evaluations, they are time consuming and labour intensive. The present study evaluated 80 red deer (Cervus elaphus) faecal samples collected in two study sites for the presence and abundance of first-stage larvae of the nematode Elaphostrongylus cervi and established pools of samples for epidemiological analysis. The analysis of 20–30 individual samples would produce a reliable estimate of the ‘true’ prevalence, and the error of the smaller sample size only doubled that of the 80 reference samples. The analysis of 5 pools of 5 pellet groups each, or of 4 pools of 10 pellet groups each, provided a reliable estimation of the ‘true’ excretion abundance estimated by the analysis of all 80 samples. These pools comprise a cost-effective and dependable alternative for measuring and obtaining comparable abundances of parasitic faecal excretion stages in red deer populations, which is very valuable for epidemiological and ecological research as well as for management purposes.
Facial nerve palsy secondary to middle-ear lipoma
Authors: Kasbekar A V , Donnelly N , Axon P 
Published: April 2008

AbstractObjective:We present the first reported case of a middle-ear lipoma presenting with facial nerve palsy. We review the available literature on middle-ear lipomas and alert the surgeon to the possibility of a lipoma occurring in this location.Case report:A 33-year-old man presented to our unit with a right-sided, House–Brackmann grade two, lower motor neurone facial palsy. A computed tomography scan revealed abnormal soft tissue in the epitympanic recess, extending to the region of the geniculate ganglion. At middle-ear exploration, a lump of fatty tissue was found filling the anterior middle-ear cleft, juxtaposed to the horizontal portion of the facial nerve. The patient's facial palsy resolved within a few weeks of surgery.Conclusion:Lipomas are a rare but real differential diagnosis of a mass in the middle ear. Early imaging is advised.