bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plant epidemics, models and analysis
Authors: Madden Laurence V. , Hughes G. 
Published: September 2006

Abstract
Plants are susceptible to many diseases; fungal, bacterial, viral, and other forms of epidemics occur commonly in agricultural systems, resulting in substantial crop yield reductions. There are two primary ways of measuring plant disease, incidence and severity. Plant disease incidence can be defined as the number of diseased plants, or plant parts expressed as a proportion of the total number of plants, or plant parts, assessed. Plant disease incidence is a binary variable, because individuals are either diseased or not. Plant disease severity, on the other hand, can be defined as the area or volume of plant tissue that is diseased, usually relative to the total plant tissue. It is a continuous variable, typically bounded by 0 and 1. In this article, emphasis is placed on incidence. Statistical issues regarding plant diseases in crops or natural systems concern the characterization of spatial patterns of disease, estimation of rates of disease increase over time, and rates of spatial spread. There is a variety of statistical tools available to quantify spatial pattern of disease incidence, which can be categorized based on the general type of analysis – point pattern or geostatistical analysis – or on whether the data consist of mapped or unmapped observations.
Quantitative Structure‐Activity Relationships (
QSARs
)
Authors: Williams Paige L. 
Published: September 2006

Abstract
Quantitative structure activity relationships (QSARs) have historically been used in the design and evaluation of new pharmaceutical products. With the rapid increase in modern computing power, the use of QSAR methods in the field of drug development has seen an explosive range of applications in the late 1990s. QSAR approaches have also been used in environmental risk assessment to predict the carcinogenicity or genotoxicity of toxic agents, and thus reduce the costs of conducting long‐term animal studies. The application of QSAR methods has traditionally encompassed two different approaches: the extrathermodynamic approach proposed by Hansch and Fujita, and the ‘substructural’ or ‘connectivity’ approach of Free and Wilson.
Radiation and Radiative Transfer
Authors: Essex Christopher 
Published: September 2006

Abstract
Radiation surrounds us, runs through us, and is even produced within us. While the term has taken on a sinister connotation since the development and use of nuclear power in the middle of the twentieth century, it is a misconception that radiation is not a natural part of the environment. There is no way to escape it entirely, neither would one want to. Sunshine is the most obvious form of radiation in our lives. Despite recent worry about it, from the standpoint of ultraviolet radiation, the world would literally die without solar radiation. Moreover, it pertains to many global environmental issues, from forecasts of global warming to ozone depletion. These topics too are burdened with misconceptions that are especially pertinent to those seeking a quantitative, environmetric outlook on radiation. Some of the most important of these will be identified in this article.
Ranks
Authors: Hallin Marc 
Published: September 2006

AbstractRank tests were introduced as a reaction against the traditional assumption of Gaussian observations. The most attractive feature of ranks and rank statistics is that they are distribution‐free, and thus, in principle, allow for exact critical values, irrespective of the underlying distribution of the observation. Their domain of application is, mainly but not exclusively, the class of semiparametric models obtained from the traditional parametric ones (location, scale, regression, autoregression, etc.) by treating the density of the underlying error or noise as an unspecified nuisance. Their popularity is explained by their success in a variety of practical situations, and their robustness against deviations from standard distributional assumptions.
Recursive Residuals
Authors: Frühwirth‐Schnatter Sylvia 
Published: September 2006

Abstract
Recursive residuals are used for model diagnostics, especially for time series models of continuous observations. By model diagnostics one means checking properties residuals should have under the assumption that the data were generated by the model under investigation. This check can be exploratory or formal. What distinguishes diagnostics based on recursive residuals from more conventional methods is the way the residuals are defined in a recursive manner from one‐step ahead predictive densities.
Rivers, Canals and Estuaries
Authors: Monismith Stephen 
Published: September 2006

AbstractEnvironmentally important flows in rivers, canals and estuaries are characterized by turbulence generated at their sides and bottoms, and are capped by free surfaces that deform in response to the underlying flow, giving rise to a rich range of behavior including multiple flow depths for a given flow and a variety of wave propagation phenomena. They also have erodible and moveable beds that respond to the flow, leading to meandering channels as well as to significant transport of sediments from the land to the sea. Estuaries, where fresh river water mixes with salty ocean water, often have significant tidal motions that play an important role in sediment dynamics, mixing of pollutants, and salinity intrusion, an increase in river salinity that can render fresh water non‐potable or even unusable for irrigation. A significant aspect of the mixing in estuaries is the difference in density between salt and fresh water, a difference that leads to buoyancy forces that significantly influence flows found in estuaries.
Seemingly Unrelated Regressions
Authors: Bartels R. 
Published: September 2006

Abstract
Seemingly unrelated regression (SUR) is a widely used modeling approach introduced by Zellner for situations where several linear regression relationships are being investigated at the same time. Examples of the use of SUR in environmetrics include Boisvert et al., who considered separate equations for the effect of water contamination on both the purchase price and rental value of farmland, and Xu, who estimated separate equations for the impact of environmental legislation on the output of each of a number of industrial sectors. The key feature in these cases is that each of the linear equations, on its own, satisfies the classical conditions underpinning the linear regression model, and hence the ordinary least squares (OLS) estimator can be used to estimate each equation individually. However, if the error terms of the different equations are correlated across the equations, then joint estimation of the equations may be able to exploit this cross equation correlation to obtain more efficient estimates.
Soil Surveys
Authors: Abbitt Pamela J. 
Published: September 2006

Abstract
Soil surveys are conducted in order to construct maps delineating soil map units (SMUs) and descriptions of the soil characteristics of each map unit. Soil survey reports are used in the areas of farming, forestry, rangeland management, conservation planning, and urban activities such as transportation planning and residential and industrial development. Information from soil surveys is needed increasingly to support analyses in the areas of soil quality and environmental research and management. Natural resource scientists need geo‐referenced data and statistical descriptions of soil characteristics in order to model the complex processes that are affected by soil properties.
Spatial Analysis in Ecology
Authors: Fortin Marie‐Josée , Dale Mark R.T. , ver Hoef Jay 
Published: September 2006

Abstract

The first step in understanding ecological processes is to identify patterns. Ecological data are usually characterized by spatial structures due to spatial autocorrelation.
Spatial autocorrelation
refers to the pattern in which observations from nearby locations are more likely to have similar magnitude than by chance alone. The magnitude, intensity, as well as extent of spatial autocorrelation can be quantified using spatial statistics. Most ecological data exhibit some degree of spatial autocorrelation, depending on the scale at which the data were recorded and then analyzed. Ecological phenomena are also characterized by the multiple ecological processes that act upon them; these processes often operate at more than one spatial scale. Ecological data are a composite of several spatial scales: trends at macroscales; patches, gradients and patterns at meso‐ and local scales; and random patterns at local and microscales. The different processes and patterns at different scales are not necessarily linear or additive, and this contributes to the degree of spatial dependence in the data.
Spatially Constrained Sampling
Authors: See Kyoungah , Song Sung‐Yell 
Published: September 2006

AbstractEnvironmental epidemiology is a discipline that relies to a large extent on observational studies; even the case–control studies that are a standard tool of epidemiologists do not approach the rigor of the design of agricultural field trials. There is a very real tension in environmental epidemiology between the desire to establish a network of causation and the lack of experimental control available in observational studies. However, when the ‘signal’ is strong enough, sometimes it is possible to establish causative relationships. To make progress with noisy data and vaguely formulated hypotheses, statistical models have been developed that allow inference even down to individual levels, such as in frailty models. Many of these models are hierarchical and some are spatial, and it is on these that this article focuses.
Stochastic Model
Authors: Preisler Haiganoush K. 
Published: September 2006

AbstractEnvironmental scientists use models – a system of assumptions presented in a mathematical framework – to study complex interrelationships in ecological processes and to assess and predict the impact of our actions on the environment, among other things. There are a variety of model types: stochastic, deterministic, numerical, to name a few. A major concept that distinguishes stochastic models from other models is the idea of probability, or randomness, that is explicit in all stochastic models.
Tessellations
Authors: Schoenberg Frederic Paik 
Published: September 2006

Abstract

A
tessellation
may be defined as a division of a space into convex polygonal regions; divisions of the
plane
(

R
2

) are most often discussed. While geometrists centuries ago reserved the term tessellation merely for divisions of the plane into
regular
polygons of equal size, most authors now define tessellations very broadly so as to include any arrangements of nonoverlapping shapes covering

R
d

, as well as partitions of other metric spaces.
Trawl Surveys
Authors: Nordahl Victor , Clark Steve 
Published: September 2006

Abstract
Trawl surveys for fishery resources are conducted throughout the world by government and non‐government agencies. Modern fishery management requires standard time series of data on management units or ‘stocks’ and their response to exploitation: trends in abundance and biomass; spawning success; biological parameters; distribution; and environmental factors that can be provided only through standardized sampling programs. Trawl surveys provide the opportunity for controlled sampling in space and time.
Up‐and‐Down Designs
Authors: Flournoy Nancy 
Published: September 2006

AbstractUp‐and‐down designs are useful for evaluating and comparing the toxicity of pesticides and other chemical compounds. In particular, the primary goal of an up‐and‐down design in toxicity studies is to estimate the dose having a prespecified toxicity rate γ, 0 > γ > 1. A secondary goal is to limit the experimental subjects that are given highly toxic exposure. Up‐and‐down designs can be sequential or group sequential.
Wavelets
Authors: Percival Donald B. 
Published: September 2006

AbstractWavelets are a special class of functions (or sequences) that are widely used for analyzing time‐ series. Just as Fourier analysis is based upon the notion of representing (or re‐expressing) a time series as a linear combination of sinusoids, the idea underlying wavelet analysis is to represent the series as a linear combination of wavelets. In Fourier analysis, each sinusoid is associated with a particular frequencyf, so what frequencies are important in a particular time series can be deduced by studying the magnitudes of the coefficients of the various sinusoids in the linear combination. In contrast, each wavelet is associated with two independent variables, namely, timetand scaleτ, because each wavelet is essentially nonzero only inside a particular interval of times, namely, [t – τ,t + τ]. Within that interval, the wavelet spends roughly an equal amount of time above and below zero, so it appears to be a ‘small wave’ centered at timetand having a width of 2τ. We can thus learn how a time series varies on particular scales across time if it is re‐expressed using wavelets.
Weibull Distribution
Authors: Fotopoulos Stergios B. , Jandhyala Venkata K. 
Published: September 2006

AbstractThe article brings together various results on the Weibull distribution in a unified manner. The introduction contains numerous references regarding applications of the Weibull distribution and subsequent sections address a variety of theoretical developments. Some of the theoretical developments covered include characterization, extreme value theory, parameter estimation and goodness of fit. The estimation and goodness of fit methods are illustrated by modeling the data on minimum temperatures in Uppsala, Sweden.
Whole Effluent Toxicity
Authors: Fox John F. , Denton Debra L. 
Published: September 2006

Abstract
Whole effluent toxicity (WET) tests are designed to estimate the toxicity of aqueous chemical mixtures, effluents, ambient (receiving) waters or stormwaters. WET tests use freshwater or marine plants, invertebrates or vertebrates to measure the aggregate toxicity of such waters. Tests for acute toxicity (‘acute tests’) measure mortality, usually after 24, 48 or 96 hours. Tests of chronic toxicity (‘chronic tests’) usually run longer and measure sublethal effects, such as reduced reproduction, growth, fertilization or larval development, in addition to mortality. Regulatory authorities recommend testing wastewaters with organisms from several phyla to determine the most sensitive test species for routine testing.
Lost in transition: Challenges in the expanding field of adult genetics
Authors: Taylor Matthew R.G. , Edwards Janice G. , Ku Lisa 
Published: October 2006

AbstractIt is increasingly clear that medical genetics has broad relevance in adult clinical medicine. More adult patients with genetic conditions are being recognized, genetic testing for adult‐onset genetic conditions is expanding, and children with genetic conditions are now more likely to survive to adulthood. While the number of patients who could benefit from medical genetic services increases, adult care providers are less well educated about clinical genetics and are not sufficiently prepared to meet the growing needs of this population. Genetics professionals may also be ill‐suited for this challenge, since geneticists and genetic counselors have traditionally had greater experience in pediatric and prenatal settings. Communication between primary care physicians who treat adults and the genetics community is currently suboptimal and the identification and subsequent referral of adult patients for genetic services need improvement. Finally, published guidelines that address how to deliver genetic services to adult patients are unavailable for many genetic conditions. In this article we address the challenges of transitioning genetics services from traditional, and largely pediatric‐based models to paradigms that can best address the needs of adult patients with genetic conditions. Potential solutions and the practicality of implementation of a team‐based approach to adult genetic medicine, including the application of genetic counseling, are also discussed. © 2006 Wiley‐Liss, Inc.
Recreational physical activity and survival among young women with breast cancer
Authors: Abrahamson Page E. , Gammon Marilie D. , Lund Mary Jo , Britton Julie A. , Marshall Stephen W. , Flagg Elaine W. , Porter Peggy L. , Brinton Louise A. , Eley J. William , Coates Ralph J. 
Published: September 2006

AbstractBACKGROUNDMost epidemiologic studies report a reduced risk of developing breast cancer associated with higher levels of recreational physical activity, but little is known regarding its effect on prognosis.METHODSIn this study, the authors investigated whether activity undertaken prior to diagnosis influenced breast cancer survival in a population‐based cohort. A follow‐up study was conducted among 1264 women ages 20 to 54 years who were diagnosed with invasive breast cancer between 1990 and 1992. Women in the study were interviewed within several months of diagnosis and were asked about their average frequency of moderate and vigorous activity at age 13 years, age 20 years, and during the year before diagnosis. With 8 to 10 years of follow‐up, all‐cause mortality status was determined by using the National Death Index (n= 290 deaths).RESULTSA modest reduction in the hazards ratio (HR) was observed for the highest quartile of activity in the year before diagnosis compared with the lowest quartile (stage‐adjusted and income‐adjusted HR, 0.78; 95% confidence interval [95% CI], 0.56–1.08). High activity was associated with a reduced HR among women who were overweight or obese at the time of diagnosis (HR, 0.70; 95% CI, 0.49–0.99) but not among ideal weight or underweight women (HR, 1.08; 95% CI, 0.77–1.52). A reduced HR was not evident for activity at age 13 years or 20 years or for average activity across the 3 periods studied.CONCLUSIONSThe results of this study provided some suggestive evidence for a beneficial effect on survival of recreational physical activity undertaken in the year before diagnosis, particularly among women who are overweight or obese near the time of diagnosis. Cancer 2006. Published 2006 by the American Cancer Society.
Clinical outcome of anaplastic thyroid carcinoma treated with radiotherapy of once‐ and twice‐daily fractionation regimens
Authors: Wang Yongjin , Tsang Richard , Asa Sylvia , Dickson Brendan , Arenovich Tamara , Brierley James 
Published: September 2006

AbstractBACKGROUNDThe purpose was to assess local control, survival, and toxicity after radiotherapy in patients with anaplastic thyroid carcinoma, and to compare clinical outcomes between once‐daily and twice‐daily fractionation regimens.METHODSA retrospective review of patients with anaplastic thyroid carcinoma (n = 47) who underwent external beam radiotherapy from 1983 to 2004 was conducted. Twenty‐three patients underwent radical radiotherapy with a radiation dose >40 Gy, and 24 patients underwent palliative radiotherapy with a dose ≤40 Gy. Of radical radiotherapy, radiation was given with once‐daily (14 patients) or twice‐daily fractionation (9 patients; 1.5 Gy per fraction) to a total dose of 45–66 Gy. Most patients (37 patients; 78.7%) were followed to death.RESULTSThe 6‐month local progression‐free rate in patients who underwent radical radiotherapy was 94.1%, significantly higher compared with palliative radiotherapy (64.6%; P = .02). The median actuarial overall survival was greater in patients with radical radiotherapy (11.1 months) compared with palliative radiotherapy (3.2 months; P < .0001). The median overall survival in patients with twice‐daily fractionation (13.6 months) was 3.3 months longer than patients treated with once‐daily fractionation (10.3 months), but the difference was not statistically significant (P = .3). For patients treated with twice‐daily fractionation, 3 patients had Grade 3 acute skin toxicity, and no patient had Grade 3 or higher esophageal toxicity.CONCLUSIONSRadiotherapy can result in local control of anaplastic thyroid carcinoma. A twice‐daily fractionation regimen is well tolerated and has a trend to longer survival, which deserves a larger study. Cancer 2006. © 2006 American Cancer Society.
Molecular symmetry and ferroelectricity in pure organic molecular crystals
Authors: Choudhury R. R. , Chitra R. 
Published: September 2006

AbstractThe molecular symmetry of all the existing organic ferroelectrics was analyzed with an intention to develop a criterion to search for new low molecular weight organic ferroelectric. We present here a summery of the analysis; it is conclude that in order to exhibit ferroelectricity in crystalline state the molecules should necessarily poses symmetry higher than C1, since this appears to be an important requirement to ensure reorientability of the electrical polarization of the crystals. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Square‐root domain wave filters
Authors: Psychalinos C. 
Published: September 2006

AbstractIn this paper the wave method is used for designing high‐order square‐root domain filters, which emulate the topology of the corresponding LC ladder prototypes. This is achieved by transposing the signal flow graph that corresponds to the wave equivalent of the elementary two‐port subnetwork in the linear domain to the corresponding one in the square‐root domain, by employing an appropriate set of complementary operators. As the equivalents of the other reactive elements are derived from the wave equivalent of the elementary subnetwork, by interchanging the terminals of the appropriate wave signals and/or using inverters, an advantage offered by the proposed technique is the modularity of the derived filter configurations. As an example, a fifth‐order lowpass square‐root domain wave filter was designed and its behaviour was studied through simulation results in order to demonstrate the validity of the proposed design technique. Copyright © 2006 John Wiley & Sons, Ltd.
Triethanolamine as an Efficient and Reusable Base, Ligand and Reaction Medium for Phosphane‐Free Palladium‐Catalyzed Heck Reactions
Authors: Li Hong Ji , Wang Lei 
Published: September 2006

AbstractTriethanolamine was found to be an efficient and reusable base, ligand and reaction medium for phosphane‐free palladium‐catalyzed Heck reactions. The olefination of iodo‐ and bromoarenes generated the corresponding products in good to excellent yields in the presence of catalytic amounts of palladium acetate in triethanolamine without any additive. Moderate yields of the desired products were obtained with activated chloroarenes. In addition, triethanolamine could be recovered and recycled for five consecutive trials without significant loss of its reactivity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Glutathione Peroxidase‐Based Amperometric Biosensor for the Detection of S‐Nitrosothiols
Authors: Musameh Mustafa , Moezzi Neda , Schauman Lisa M. , Meyerhoff Mark E. 
Published: October 2006

AbstractA new biosensor is described for the detection of S‐nitrosothiols (RSNOs) based on their decomposition by immobilized glutathione peroxidase (GPx), an enzyme containing selenocysteine residue that catalytically produces nitric oxide (NO) from RSNOs. The enzyme is entrapped at the distal tip of a planar amperometric NO sensor. The new biosensor shows good sensitivity, linearity, reversibility, and response times towards various RSNO species in PBS buffer, pH 7.4 . In most cases, the response time is less than 5 min, and the response is linear up to 6 μM of the tested RSNO species. The lowest detection limit is obtained for S‐nitrosocysteine (CysNO), at approx. 0.2 μM. The biosensor's sensitivity is not affected by the addition of EDTA as a chelating agent; an advantage over other potential catalytic enzymes that contain copper ion centers, such as CuZn‐superoxide dismutase and xanthine oxidase. However, lifetime of the new sensor is limited, with sensitivity decrease of 50% after two days of use. Nonetheless, the new amperometric GPx based RSNO sensor could prove useful for detecting relative RSNO levels in biological samples, including whole blood.