bluuebunny/crossref_metadata_2025 huggingface dataset:
Resampling Methods
Authors: Friedl Herwig , Stampfer Erwin
Published: September 2006

Statistical inference is based generally on some statistics (estimates) that are functions of the data. Their sampling distributions depend on the underlying population and therefore are unknown. Resampling methods offer strategies to estimate or approximate the sampling distribution of a statistic or its characteristics. These include accuracy measures of an estimate like its bias or the mean squared error, or relevant quantiles of a test statistic, among others.
Risk Assessment, Ecological
Authors: Halbrook Richard S.
Published: September 2006

An Ecological Risk Assessment (ERA) is a process that estimates the probability of an adverse effect on nonhumans. There are three major groups involved with the ERA process; the risk manager (responsible for making decisions), risk assessor (technical component of the assessment), and affected or interested parties. The major phases of an ERA are the problem formulation phase, analysis phase, and risk characterization phase. The end product of the ERA is a risk assessment report prepared by the risk assessor for the risk manager. The risk manager with use results of the ERA, along with economical, legal, and social factors in making risk management decisions and communicating with stakeholders regarding these decisions.

Prepared by: Richard S. Halbrook
Risk Assessment, Management and Uncertainties
Authors: Griffiths Richard
Published: September 2006

The need to understand the risks of an undertaking has led to the development of systematic methods of analysis for a number of areas of application. Some are concerned mainly or even solely with one kind of potential gain or loss, e.g. financial, whilst others are more obviously multidimensional, involving factors that are essentially incommensurate. Industrial impact on the environment is the focus of this article, and the term
industrial and environmental risk is used
to indicate the general scope. This article attempts to trace the development of the subject in such a way as to illustrate concepts and methods that have a general relevance across a number of specific areas of application. It is emphasized that risk is a multidimensional and dynamic concept that defies attempts to encompass its complexity within a single disciplinary framework, or to express it quantitatively on a single scale. The article emphasizes the need to be aware of the interaction between factual information and the value systems of stakeholders. Pitfalls of not maintaining this awareness are illustrated. The article aims to promote a critical approach to the use of risk assessment methods and concepts in pursuing the objectives of risk management.
Risk Perception
Authors: Everitt Brian S.
Published: September 2006

Life is a risky business, and deciding which risks are worth taking and which should be avoided has important implications both for an individual's lifestyle, and the way society operates. The benefits gained from taking a risk need to be weighed against the possible disadvantages. Acceptable risk is proportional to the amount of benefits. For the individual, living life to the fullest means achieving a balance between reasonable and unreasonable risk, and this will often be a matter of judgement depending largely on the individual's personality. However, in society as a whole, where the same balancing act is required, it has to be achieved through political action and legislation.
Robust Regression
Authors: Jorgensen Murray
Published: September 2006

Unusual observations can have a large effect on least squares fits of regression coefficients. The most common defenses against this problem are residual plots and the diagnostic statistics based on residuals and leverages. These tools are most effective when the dataset is moderate in size and the analyst is in close touch with, or is, the person who collected the data. However, regression diagnostics become very time consuming to use in large data sets. In this situation it may be preferable to use more
resistant
estimators that are relatively unaffected by even large changes to a small proportion of the data. In general, resistance must be ‘purchased’ at the cost of some loss of efficiency when the standard model assumptions hold, but these assumptions are seldom tenable in large data sets anyway. Regression diagnostics and robust regression are regarded by some as conflicting solutions to the problem of the sensitivity of standard least squares regression parameter estimates to unusual, possibly erroneous, observations. However, the two approaches can be seen as complementary. Residuals from robust fits can highlight interesting groups of observations not obvious from standard residual plots; leverage diagnostics can supplement the fits of some convenient, but only partially robust, regression methods.
S+Spatialstats
Authors: Vega Silvia C. , Kaluzny Stephen P.
Published: September 2006

S+SpatialStats is an add‐on module to the S‐Plus system for data analysis and graphics. S‐Plus is an environment for data analysis that provides an object‐oriented programming language and a multitude of functions for the statistical analysis of data. +patialStats provides a comprehensive suite of tools designed for the statistical analysis of
spatial
data. The current version, 1.5, features a graphical user interface (GUI), that is menus and dialogs designed for convenient access to the functionality described in this article.
Seismological Modeling
Authors: Rathbun Stephen L.
Published: September 2006

The precise assessment of the long‐term risk of major earthquakes is required for setting insurance rates, for establishing appropriate building codes, and for allocating resources to emergency management. The locations of earthquake epicenters’ together with the times at which they occur, form a spatiotemporal point pattern. If, in addition, their magnitudes (on the Richter scale) are available, then one has a marked spatiotemporal point pattern. For risk assessment, one shall assume that this pattern is a realization of a marked spatiotemporal point process, a random mechanism for generating the locations and times of events as well as their marks. The statistical approach to earthquake risk assessment depends on whether one is interested in assessing risk at a specific site (e.g. Los Angeles), or in assessing risk as a function of location. For the former, one shall consider models for the marginal temporal point pattern formed by the times of seismological events. Methods for fitting parametric models are described, and then the use of fitted models for assessing risk is considered. To assess risk as a function of location, the marginal spatial point pattern is considered. Here, a nonparametric approach is described for estimating the intensity of earthquake epicenters as a function of location.
Criticality, Self‐Organized
Authors: Li Bai‐Lian
Published: September 2006

The causes and possible relations between the abundance of fractal structures (
see
Fractal dimensions) and 1/
f
signals found in nature have puzzled scientists for years. Based on observations of computer simulations of the cellular automata sandpile model, the term self‐organized criticality (SOC) was invented by theoretical physicists and was used to explain a universal dynamic organizing process governing various fractal growths in space and time. SOC describes that systems organize themselves so their internal dynamics produce critical behavior over a very wide range of length scales. The term consists of two parts.
Self‐organization
has been used to describe the ability of certain nonequilibrium systems to develop structures and patterns often without explicit pressure or involvement from outside the systems.
Criticality
is a technical word used in connection with phase transitions, and has a very precise meaning, in which the system becomes critical when all members of the system influence each other and events of all sizes occur.
Sensitivity Analysis
Authors: Fassò Alessandro , Perri Pier Francesco
Published: September 2006

Sensitivity analysis (SA) concerns the mathematical model representation of a physical system, and attempts to assess the sensitivity of the model outputs to variations of model inputs given by variables or parameters and variations of model assumptions.
Sick Building Syndrome
Authors: Zhang Heping
Published: September 2006

Sick building syndrome (SBS) is loosely defined as an increase in the frequency of a constellation of acute nonspecific symptoms characteristically affecting multiple occupants of a building.
Sign Tests
Authors: Al‐saidy Obaid M.
Published: September 2006

The sign test is the oldest form of the distribution free tests, first introduced by Arbuthnot in 1710. Aside from its well‐established status, the sign test is easy to carry out and is applicable in a variety of situations. This article discusses the ordinary sign test for the median based on a single sample and on paired samples, and the Cox–Stuart sign test for detecting monotonic trend.
Simulation and Monte Carlo Methods
Authors: Storvik Geir
Published: September 2006

Simulation involves using a model to produce results. The growing power of computers and the evolving simulation methodology have led to the recognition of computation as a third approach for advancing the natural sciences, together with theory and traditional experimentation. Many applications of simulation are based on purely deterministic models. If the model contains a stochastic element, we have stochastic simulation, which will be the issue in this article. Stochastic simulation is often called Monte Carlo sampling, especially in engineering and physics literature.
Size‐Biased Sampling
Authors: Zimmerman Dale
Published: September 2006

Size biased sampling refers to a type of nonrandom sampling in which the likelihood of an object's inclusion in the sample is proportional to the size (or length) of the object.
Small Area Estimation
Authors: Lahiri P. , Meza Jane L.
Published: September 2006

The term
small area
usually refers to a geographical area in which a limited number of observations are available. How does one produce reliable small‐area estimates? It is evident that various relevant sources of information need to be gathered from outside the survey itself. Once these have been identified, one needs to develop a method that will combine information from all relevant sources. This is usually done by either implicit or explicit models. In this article, design‐based estimators, indirect estimators and model‐based estimators will be discussed. Most of these methods borrow information from related areas and use auxiliary data by either implicit or explicit modeling.
Smoothing in Environmental Epidemiology
Authors: Wand M.P. , Schwartz J.
Published: September 2006

Smoothing is a branch of regression analysis that allows for a predictor to impact the response as an arbitrary smooth function. It is also known as nonparametric regression. The purpose is to alleviate the restrictiveness of parametric functional relationships, such as that imposed by linearity.
Soil Conservation and Remediation
Authors: Fyfe W.S.
Published: September 2006

Our life support systems, our quality of life, depend on a number of major parts of our Earth systems and all are related. These include: quality air to breathe; quality water for all species; a reliable climate; quality soil to support all the surface biomass; biodiversity. All are changing rapidly due to human actions. For truly sustainable development, for food security, we must conserve soil and stop soil erosion.
Soil Wetness Index
Authors: Basist Alan , Williams Claude , Grody Norman , Ross Thomas , Shen Sam
Published: September 2006

Soil wetness is identified as the magnitude of liquid water residing in a vertical profile observable by the satellite instrument. The frequencies flown on the SSMI (Special Sensor Microwave Imager) instrument are incapable of penetrating deep into the soil or through a dense vegetative canopy. Therefore, the index represents the amount of water in the upper reaches of the soil (top few centimeters) or where a dense canopy is present, it represents the water intercepted by the canopy. The index can also monitor the amount of liquid water present in a melting snow pack.
Source Apportionment
Authors: Sato Manabu , Ohtaki Megu
Published: September 2006

The concept of
source apportionment
is identifying the sources of air pollution and estimating the apportionments of the concentrations of the pollutants observed at the sites in the environment. The results obtained can be used to help manage effectively the quality of the environment.
Space‐Time Kalman Filter
Authors: Cressie Noel , Wikle Christopher K.
Published: September 2006

The Kalman filter arose out of R.E. Kalman's interest in applying the concept of state vectors to the Wiener filtering problem. The success of this method was evident in early applications to trajectory estimation and control of spacecraft; it was so successful, in fact, that the Kalman filter quickly became an essential component of modern control systems theory and practice. This initial success led to the propagation of Kalman‐filtering ideas to other scientific disciplines, within which the methodology was adapted to suit numerous state–space oriented problems. Kalman filtering (of spatial data) is still an active area of research in the atmospheric and oceanic sciences.
Species Diversity
Authors: Kempton R.A.
Published: September 2006

In much environmental assessment, biodiversity is measured by the number of species in an area – the species richness. However, using the number of species to measure diversity requires the resolution of a number of issues. First, there is the choice of taxonomic group, since differences in the species concept and the levels of discrimination applied in different taxa mean that species counts cannot automatically be combined across groups. Measuring species richness at the global or large regional scale often runs into problems of synonymy, the same species being given different names in different regions. A simple species count also gives all species equal value, which may be inappropriate from a conservation standpoint. Furthermore, with more mobile taxa such as birds, the total count can be substantially inflated by transient vagrants that may be better omitted from environmental comparisons. These issues will vary in importance, and their resolution will depend on the objective of the diversity assessment. A more pervasive problem arises in the estimation of species richness from samples.
Spherical Statistics
Authors: Jupp Peter E.
Published: September 2006

Spherical statistics is concerned with data that lie on the sphere of unit radius, and so are unit vectors representing directions in three‐dimensional space. Typical examples of such data are directions of paleomagnetism in rock or directions birds fly from a nest.
Splines in Nonparametric Regression
Authors: Wahba Grace
Published: September 2006

This article is interested in splines as tools for visualizing and analyzing noisy observational data, and so restricts itself to smoothing splines and regression splines. The article first describes the univariate polynomial smoothing spline, which may be thought of as the forerunner of spline functions used in data analysis. It then describes cross validation and Generalized Cross Validation (GCV) for choosing the smoothing parameter. After briefly describing regression splines, this entry then describes a number of generalizations of the univariate smoothing spline to various domains, which are obtained via the solution of a variational problem. These include the thin plate spline, the histospline, splines on the sphere, vector splines on the sphere, hybrid splines, partial splines, and smoothing spline analysis of variance (ANOVA) models on complex domains. It then ends with some remarks on computing. Publicly available software is mentioned along the way.
Stochasticity
Authors: Cox D.R.
Published: September 2006

Stochasticity is the abstract noun associated with the adjective
stochastic
, which in its modern usage means
random
, with nuances that if represented mathematically, probability is the appropriate language and moreover, often, that there is a dynamic element involved.
Superfund Site, US
Authors: Bowers Teresa Suter
Published: September 2006

The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) provides authority for the cleanup of abandoned landfills, warehouses, and other properties sufficiently contaminated by hazardous waste such that they were deemed to represent threats to human health and the environment. Superfund sites become identified as such when they are added to the US National Priorities List (NPL), a list prioritizing sites most in need of remedial response due to contamination.
Sustainability
Authors: Bossel Hartmut
Published: September 2006

Different notions of sustainability are introduced, and conditions for sustainability are discussed. Fundamental environmental properties force systems to adopt certain fundamental orientations. Inadequate attention to this multidimensional set of ‘basic orientors’ leads to unsustainability. Sustainability can be assessed by defining a corresponding system‐specific set of indicators; a sample set is provided. Ethical considerations implicitly or explicitly shape particular paths to sustainability.
Systematics, Numerical Methods
Authors: Giribet Gonzalo
Published: September 2006

An introduction to biological systematics is provided with description of basic principles in systematics and tree topologies. Tree search strategies for methods based on optimality criteria are discussed, and common modern software is briefly introduced. The article is complemented with a list of general recommended readings.
Temporal Change
Authors: Esterby Sylvia
Published: September 2006

The study of temporal change in environmental quality indicators is motivated by the need to know if the state of the environment has deteriorated or, in some cases, if it has improved as a result of the removal or lessening of stress on the system. The data available for study of temporal change are observational, and usually it is not even possible to relate there to observational data on the level of the stressor. Thus, statements about the change in the quality indicator are made on the basis of measurements and analysis, where other effects have been removed as much as possible from the term corresponding to change over time.
Trend Tests For Binary Data
Authors: Corcoran Chris
Published: September 2006

In the context of biomedical studies (particularly in fields such as environmental toxicology or epidemiology), trend tests are widely used to detect a dose–response relationship between ordered levels of some exposure and the probability of a binary outcome of interest.
The International Environmetric Society
Authors: Esterby S.R.
Published: September 2006

The International Environmetrics Society (TIES) was founded in 1989. The objectives of the society are to foster the development and use of statistical and other quantitative methods in environmental sciences, environmental engineering and environmental monitoring and protection.
Threshold Models
Authors: Drees Holger
Published: September 2006

In many environmental contexts extreme random events may lead to hazardous situations or even catastrophes. Extreme sea levels, for example, can cause floods, and a high concentration of air pollutants can constitute a severe health threat. In order to assess these risks, it is necessary to estimate the probability that the quantity under consideration (e.g. sea level or concentration of pollutants) exceeds certain high thresholds. However, since by definition such extreme events rarely occur, their relative frequency is a virtually useless estimator of the exceedance probability. So if there is no theory at hand explaining the underlying physical random mechanism and thus providing the statistician with a sound parametric model, which holds true even in the tail regions of the distribution, then clearly specific models for the tails are needed. Since results for the lower tail can be deduced from the results for the upper tail applied to the observations multiplied with −1, it suffices to examine exceedances over high thresholds.
Time Series
Authors: Bühlmann Peter
Published: September 2006

Many data occur in the form oftime serieswhere observations are recorded at different times. The presence of the notion of time often creates dependence among observations whose structure is of particular interest in time series analysis. When viewed from a stochastic perspective, time series dataxtwitht= 1, 2, …,nare one finite realization of sample sizenfrom a stochastic process {Xt: t = 0, ±1, ±2, …}:xtandXtare generallyr‐vectors whose components take values on the real line, or in some discrete space being categorical or having an order. The restriction to equi‐spaced time recordings can be relaxed tot1 > t2 > … > tnand the data‐generating process can be indexed by continuous time {Xt}, for example witht[0, 1].
Time Series, Periodic
Authors: Lund Robert B. , Seymour Lynne
Published: September 2006

Periodicities arise naturally in many observed environmental random sequences. Time series of hourly tidal levels, monthly average temperatures, daily streamflow discharges, etc., all display periodicities in their first and second moments. This article discusses general properties and statistical analysis of such periodic time series.
T
oxic Substances Control Act,
US
Authors: Margosches Elizabeth H.
Published: September 2006

The Toxic Substances Control Act (TSCA) regulates commerce and protects human health and the environment by requiring testing and necessary use restrictions on certain chemical substances.
Toxicology, Environmental
Authors: John Bailer A. , Oris James T.
Published: September 2006

Environmental toxicology, and indeed much of toxicology, has intimate ties to regulatory action. Thus, one context for viewing environmental toxicology is its place in environmental risk assessment. Many models for analyzing environmental risk exist. The most common model was a four step process described in a US National Academy of Sciences publication. In this model, risk assessment is comprised of the following components: hazard identification, exposure assessment, dose–response modeling and risk characterization. Within this framework, environmental toxicology issues are encountered at each step of the process.
Trace Gas Emissions
Authors: Frolking Steve
Published: September 2006

Trace gases are generally defined as those with low concentrations in the normal atmosphere. Many trace gases of interest are biogenic, produced and/or consumed by micro‐organisms in soils, sediments, or water columns, or produced by plants and animals. Others are entirely synthetic and are a by‐product of industrial activity.
Trace Level Detection
Authors: Little Tom Tadfor , Miller Guthrie , Martz Harry F. , Inkret William C.T. , Schillaci Mario E.
Published: September 2006

An important component of protecting individuals from the hazards of radiation exposure is to be able to determine whether radionuclides have been taken into the body, and in what quantities. For example, a urine sample from an individual who works with plutonium can be analyzed by α spectroscopy or mass spectroscopy to determine if plutonium is present in the sample, and hence to make an inference about possible plutonium intakes in the individual's history. Often, the quantities of plutonium that one seeks to detect are comparable to the measurement uncertainties. Hence, statistical considerations are a very important aspect of the detection methodology.
Transmission/Disequilibrium Test
Authors: Seillier‐moiseiwitsch Françoise , Niu Tianhua
Published: September 2006

The transmission/disequilibrium test (TDT) can be utilized as a test of linkage between a marker and a disease locus or as a test of association between these loci. It relies on the marker information from triads consisting of parents and their affected child. Its properties depend on the purpose it is used for. Its validity for stratified populations makes it particularly attractive. Also, it is often more powerful than allele‐sharing methods for complex diseases.
Tree Morphology
Authors: Maguire Douglas A.
Published: September 2006

Tree morphology at its most basic level refers to the geometric shape of different portions of the tree, most commonly the bole (main stem) or the tree crown (foliated portion). The geometric solid describing the crowns of various tree species, for example, can range from a cone or paraboloid to an ellipsoid or inverted neiloid. The morphology of tree root systems, while of much interest to foresters and ecologists, has less commonly been characterized with respect to its geometric occupancy due to the difficulty of direct observation and its more irregular pattern.
Turbulent Diffusion
Authors: Chatwin Philip , Sullivan Paul
Published: September 2006

From the point of view of the environment, arguably the most important practical property of fluids (i.e. liquids and gases) in motion is how they transport heat and matter. Examples of the latter include the spreading of foreign gases (e.g. SO2, NO2 and many others) and particulates in the atmosphere, the dispersion of plankton in the seas and oceans, and the distribution of salt in estuaries. Nearly all fluid motions in the environment are turbulent. This means that the motion is unpredictable, changing apparently at random in both space and time.
Uncertainty Analysis
Authors: Smith Eric
Published: September 2006

In risk assessment, available information is collected and utilized to make decisions regarding the risk associated with a particular stressor such as a chemical, biological, or physical agent. Decisions in risk assessment are typically not crystal clear and hence there is uncertainty. Uncertainty analysis is the part of risk assessment that focuses on the uncertainties in the assessment. Important components of uncertainty analysis include qualitative analysis that identifies the uncertainties, quantitative analysis of the effects of the uncertainties on the decision process, and communication of the uncertainty. Uncertainty analysis covers a wide range of techniques and analyses. The analyses range from simple descriptive procedures to quantitative estimation of uncertainty, to more formal decision‐based procedures. The analysis may be qualitative or quantitative, depending on the level of resolution required and the amount of information available. The assessment of uncertainty is also tied to the view of uncertainty from the scientist and risk manager.
Utility Theory
Authors: French Simon
Published: September 2006

Utility theory has a long history, tracing its origins back to Bernoulli in the early eighteenth century; but only in the last half century have the assumptions behind the use of ‘utilities’ been understood. At its simplest, utility provides a model of the preferences of a decision‐maker (DM) between alternatives. The complexity arises when it is asked what aspects of the DM's preferences are modeled and how the model is to be used in an analysis. For instance, it is possible to model strength of preference and risk attitude either separately or simultaneously. Moreover, is the model to be used descriptively, reporting peoples preferences ‘as they are’, or is it to used prescriptively, guiding the evolution of judgment in a complex evaluation process? Thus a very brief guide to different types of utility model is given in this article, followed by the use of such models in analyses. First a single DM is considered; later the use of utility theory within group and societal contexts is discussed.
Validation Studies
Authors: Spiegelman Donna
Published: September 2006

Validation studies obtain information on measurement errors in exposures and other covariates used in epidemiological studies by comparing the conventional exposure measurements with ‘gold standard’ measurements.
Water Quality
Authors: Whitehead Paul G.
Published: September 2006

In addition to being major sources of water, river systems are used as the principal disposal pathways for industrial, agricultural, and domestic effluent. As demand for water increases and water quality deteriorates, there is a requirement for effective decision making techniques which can be applied to solve water quality management problems. Over the past century, increasing effort has been devoted to the development of suitable techniques, largely by engineers, system analysts, and scientists. As long ago as 1912 the Royal Commission on Environmental Pollution in the UK proposed a simple 1 to 8 ratio for effluent discharge to river flow in an attempt to clean up UK rivers. In the USA major developments by Streeter and Phelps led to the dissolved oxygen (DO) and biochemical oxygen demand (BOD) equations that enable steady‐state and dynamic modeling of oxygen balances in rivers. Major studies in the area of water quality modeling were undertaken in the US (e.g. Great Lakes, Delaware Study), the UK (e.g. Trent Study and Bedford Case Study), and in Australia (Peel–Harvey Inlet), and these all evolved new techniques to address major water quality problems.
Weather Prediction
Authors: Lin Charles
Published: September 2006

At the heart of the weather forecast procedure is the numerical weather prediction model. The governing equations are the equations for the three spatial components of momentum, temperature, humidity and mass. The model is made from a spatial discretization of the governing equations on the entire globe using numerical methods (e.g. finite difference and spectral methods). The finite model grid size means that parameterizations of physical processes such as mixing and convective adjustment are necessary. Such models typically have millions of degrees of freedom, and frequently require supercomputers for their efficient solution. The equations are integrated forward in time, again using numerical methods, starting from some initial state. Global forecasts of meteorological quantities such as surface temperature and precipitation are made for up to about two weeks.
Wildlife Ecology
Authors: Bowyer R. Terry
Published: September 2006

Wildlife ecology is concerned principally with the biology of birds and mammals, although broader taxonomic definitions are also possible. Studies in wildlife ecology often involve species that are hunted, trapped, or are of additional economic or aesthetic importance to humans, including species that are rare, threatened, or endangered. Modern wildlife ecology often applies ecological theory to management and conservation of animals, but also includes theoretical studies on species that are considered wildlife. The focus of the discipline is on the population rather than the individual; consequently, population ecology is central to most wildlife conservation and management.
Positive association of schizophrenia to JARID2 gene
Authors: Pedrosa Erika , Ye Kenny , Nolan Karen A. , Morrell Lauren , Okun Jeffrey M. , Persky Adam D. , Saito Takuya , Lachman Herbert M.
Published: September 2006

Dysbindin (DTNBP1) is a positional candidate gene for 6p22.3‐linked schizophrenia (SZ). However, so far, no disease‐causing alleles have been identified. DTNBP1 is immediately adjacent to JARID2, a member of the ARID (AT‐rich interaction domain) family of transcription modulators. We have previously suggested that proteins which bind to AT‐rich domains could play a role in SZ pathogenesis. Consequently, we explored the possibility that JARID2 itself could be a candidate gene for 6p22.3‐linked SZ. We used a case control design to analyze single nucleotide polymorphisms (SNPs) and insertion/deletion variants affecting AT‐rich domains in both the DTNBP1 and JARID2 genes. Three of the DTNBP1 SNPs analyzed had previously been shown to be associated with SZ. We did not detect any significant difference in allele, genotype or haplotype distribution for any of these DTNBP1 markers. However, we did detect a significant difference in allele distribution for a tetranucleotide repeat polymorphism in the JARID2 gene that affects an AT‐rich domain. A significant increase in short alleles (less than 11 repeats) was found in patients with SZ (χ2 = 7.02; P = 0.008). No other JARID2 marker displayed statistically significant allele and genotype distributions. Our findings suggest that JARID2 should be viewed as a candidate gene for 6p22.3‐linked SZ. © 2006 Wiley‐Liss, Inc.
Association of tagSNPs in the urokinase‐plasminogen activator (PLAU) gene with Alzheimer's disease and associated quantitative traits
Authors: Ozturk Ayla , Minster Ryan L. , DeKosky Steven T. , Kamboh M. Ilyas
Published: September 2006

The gene coding for urokinase‐plasminogen activator (PLAU) is a strong biological and positional candidate gene for Alzheimer's disease (AD). Previously some studies have examined the role of common variation in the PLAU gene with AD risk but the results have been inconsistent and this inconsistency could have been due to the use of relatively small sample sizes. In this study we evaluated the distribution of four tagSNPs (rs2227562 in intron 5, rs2227564 in exon 6, rs2227571 in intron 9, and rs4065 in 3′UTR) in the PLAU gene in a large case‐control study consisting of up to 1,000 AD patients and 697 white control subjects. We examined the role of these tagSNPs with AD risk and quantitative traits of AD, including age‐at‐onset (AAO), disease duration, and mini‐mental state examination (MMSE) scores. The 3′UTR SNP revealed modest significant association with risk (OR = 0.71, 95% CI: 0.53–0.95; P = 0.02), AAO (P = 0.036) and disease duration (P = 0.04) of AD. In addition, the intron 9 SNP also revealed a significant association with AAO (P = 0.01) and disease duration (P = 0.006). Our data on a large number of AD cases and controls suggest that genetic variation in PLAU may affect the risk and AAO of AD. © 2006 Wiley‐Liss, Inc.
Effects of SCA1, MJD, and DPRLA triplet repeat polymorphisms on cognitive phenotypes in a normal population of adolescent twins
Authors: Luciano M. , Hine E. , Wright M.J. , Duffy D.L. , MacMillan J. , Martin N.G.
Published: September 2006

The expansion of unstable trinucleotide CAG repeat polymorphisms of a number of genes causes several neurodegenerative disorders with decreased cognitive function, the severity of the disorder being related to allele length at the triplet repeat locus. While the effects of repeat length have been well studied in clinical samples, there has been little investigation of the effects of triplet repeat variation in the normal range for these genes. We have, therefore, examined linkage and association for three CAG triplet repeat markers (Spinocerebellar Ataxia Type 1, SCA1; Machado‐Joseph Disease, MJD; Dentatorubro‐pallidoluysian Atrophy, DRPLA) to assess their contribution to variation in cognitive ability (IQ, reading ability, processing speed) in a normal, unselected sample of adolescent twins (248 dizygotic (DZ) sibling pairs, aged 16 years). Association tests, performed in Mx and QTDT, showed a consistent positive association of SCA1 with Arithmetic (P = 0.04). While association was supported between SCA1 and Cambridge reading scores and between DRPLA and inspection time, results were inconsistent across software packages. Given the number of statistical tests performed, it is unlikely that trinucleotide repeat variation in the normal range for these genes influences variation in normal cognition. © 2006 Wiley‐Liss, Inc.
Titelbild: Making the True “CP” Ligand (Angew. Chem. 37/2006)
Authors: Cordaro Joseph G. , Stein Daniel , Rüegger Heinz , Grützmacher Hansjörg
Published: September 2006

Die Suche nach Cyaphid, dem Phosphor‐Äquivalent von Cyanid, war lange eine Herausforderung. H. Grützmacher et al. schildern in der Zuschrift auf S. 6305 ff., wie sie den ersten stabilen terminalen Cyaphid‐Komplex, [RuH(CP)(dppe)2] (dppe=Bis(1,2‐diphenylphosphanylethan)), herstellten. In einer Silyl‐geschützten Vorstufe war das Ru‐Zentrum zunächst durch das P‐Atom des CP‐Liganden koordiniert. Die Entfernung der Silyl‐Gruppe ergab dann den C‐koordinierten Ru‐Komplex, dessen Struktur im Titelbild zu sehen ist.
Cover Picture: Making the True “CP” Ligand (Angew. Chem. Int. Ed. 37/2006)
Authors: Cordaro Joseph G. , Stein Daniel , Rüegger Heinz , Grützmacher Hansjörg
Published: September 2006

The quest for cyaphide, the phosphorus equivalent of cyanide, has been a challenge for many years. In their Communication on page 6159 ff., H. Grützmacher and co‐workers describe their approach to prepare the first stable terminal cyaphide complex [RuH(CP)(dppe)2] (dppe=bis(1,2‐diphenylphosphinoethane)). In an initial silyl‐protected complex, the Ru center was P‐coordinated by the CP ligand. Removal of the silyl group yielded the C‐coordinated Ru complex, whose structure is shown on the cover picture.
3‐Hydroxybenzene 1,2,4‐Trisphosphate, a Novel Second Messenger Mimic and unusual Substrate for Type‐I myo‐Inositol 1,4,5‐Trisphosphate 5‐Phosphatase: Synthesis and Physicochemistry
Authors: Mills Stephen J. , Dozol Hélène , Vandeput Fabrice , Backers Katrien , Woodman Timothy , Erneux Christophe , Spiess Bernard , Potter Barry V. L.
Published: September 2006

3‐Hydroxybenzene 1,2,4‐trisphosphate 4 is a new myo‐inositol 1,4,5‐trisphosphate analogue based on the core structure of benzene 1,2,4‐trisphosphate 2 with an additional hydroxyl group at position‐3, and is the first noninositol based compound to be a substrate for inositol 1,4,5‐trisphosphate 5‐phosphatase. In physicochemical studies on 2, when three equivalents of protons were added, the 31P NMR spectrum displayed monophasic behaviour in which phosphate‐1 and phosphate‐2 behaved independently in most of the studied pH range. For compound 4, phosphate‐2 and phosphate‐4 interacted with the 3‐OH group, which does not titrate at physiological pH, displaying complex biphasic behaviour which demonstrated co‐operativity between these groups. Phosphate‐1 and phosphate‐2 strongly interacted with each other and phosphate‐4 experienced repulsion because of the interaction of the 3‐OH group. Benzene 1,2,4‐trisphosphate 2 is resistant to inositol 1,4,5‐trisphosphate type I 5‐phosphatase catalysed dephosphorylation. However, surprisingly, 3‐hydroxybenzene 1,2,4‐trisphosphate 4 was dephosphorylated by this 5‐phosphatase to give the symmetrical 2,3‐dihydroxybenzene 1,4‐bisphosphate 16. The extra hydroxyl group is shown to form a hydrogen bond with the vicinal phosphate groups at −15 °C, and 1H NMR titration of the ring and hydroxyl protons in 4 shows the OH proton to be strongly stabilized as soon as the phosphate groups are deprotonated. The effect of the phenolic 3‐OH group in compound 4 confirms a critical role for the 6‐OH group of the natural messenger in the dephosphorylation mechanism that persists even in radically modified analogues.
A simple method to identify supramolecules in action: Hill coefficients for exergonic self‐assembly
Authors: Bhosale Sheshanath , Matile Stefan
Published: September 2006

Precise supramolecular architecture is often essential for significant function. Simple methods to reliably and rapidly demonstrate the existence of such supramolecular structure and function at relevant concentrations in complex systems are badly needed. Hill plots, describing the dependence of a signal on the n‐th power of the monomer concentration, are compatible only with the identification of supramolecules that do not really exist, that is, endergonic self‐assembly (Litvinchuk et al., J Am Chem Soc 2004;126:10067). Here, we show that the artificial increase in monomer concentration by chemical denaturation restores compatibility of Hill plots with exergonic self‐assembly and affords Hill coefficients n > 1 for stable supramolecules. Recent rigid‐rod π‐stack architecture with photosynthetic and ion channel activity is used as timely example, circular dichroism (CD) spectroscopy as method of choice for both sensitive and selective detection under relevant conditions. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Colchicine delays the development of hepatocellular carcinoma in patients with hepatitis virus‐related liver cirrhosis
Authors: Arrieta Oscar , Rodriguez‐Diaz Jose Luis , Rosas‐Camargo Vanessa , Morales‐Espinosa Daniela , de Leon Sergio Ponce , Kershenobich David , Leon‐Rodriguez Eucario
Published: September 2006

BACKGROUND

Hepatocellular carcinoma (HCC) is a malignant neoplasm associated with liver cirrhosis, with an annual incidence of 3% to 9%, which is one of the main causes of death in patients with cirrhosis. Viral hepatitis is associated with an increased risk of HCC, probably due to an inflammatory reaction. Colchicine is an antiinflammatory agent that inhibits the formation of intracellular microtubules, affecting mitosis and fibrogenesis. Diverse clinical studies have failed to demonstrate the benefit of colchicine over the progression of fibrosis in patients with liver cirrhosis; nevertheless, to the authors' knowledge there are no studies that evaluate its effect in the development of HCC.

METHODS

The effect of the administration of colchicine on the development of HCC was evaluated in 186 patients with hepatitis virus‐related liver cirrhosis in a retrospective cohort study. The minimum follow‐up time was 3 years (median, 84 months ± 2.8 months). One hundred sixteen patients received treatment with colchicine. The characteristics of both groups were similar.

RESULTS

The percentage of patients who developed HCC was significantly smaller in the colchicine group when compared with the noncolchicine group (9% vs. 29%; P = .001). On multivariate analysis, an α‐fetoprotein level ≥5 ng/dL (P = .03), a platelet count <100,000 at diagnosis (P = .05), alanine aminotransferase ≥52 IU (P = .006), and a lack of treatment with colchicine (P = .0001) were found to be associated with an earlier development of HCC. The average time for the development of HCC was 222 months ± 15 months and 150 months ± 12 months in the patients who received and who did not receive colchicine, respectively.

CONCLUSIONS

The results suggest that treatment with colchicine prevents and delays the development of HCC in patients with hepatitis virus‐related cirrhosis. The protective mechanisms of colchicine over the development of HCC could be related to antiinflammatory properties and inhibition of mitosis. Prospective studies to confirm this observation with a greater number of patients and long‐term follow‐up may be indicated. Cancer 2006. © 2006 American Cancer Society.
Health profiles of younger and older breast cancer survivors
Authors: Stava Charles J. , Lopez Adriana , Vassilopoulou‐Sellin Rena
Published: September 2006

BACKGROUND.

Over the past several decades, the incidence of prolonged survival after a diagnosis of cancer has increased; however, little is known regarding the long‐term health profiles of cancer survivors in general and of breast cancer survivors in particular. To obtain more information concerning the consequences of surviving breast cancer, the authors conducted a large‐scale health survey of patients who had been treated for the disease at their institution.

METHODS.

A descriptive analysis of information was provided by cancer survivors. Of the breast cancer survivors who were studied, 695 women were age <45 years, 580 women were between ages 46 years and 54 years, and 655 women were age > 55 years at the time of diagnosis. Their medical and psychosocial responses were analyzed and compared with those of age‐matched responders in a national survey.

RESULTS.

Younger breast cancer survivors received chemotherapy more often than older survivors and were more likely to report memory loss and that cancer had affected their overall health adversely. Several other differences in physiologic and psychosocial characteristics, such as interpersonal relationships, also emerged.

CONCLUSIONS.

Physiologic and psychosocial differences distinguished younger breast cancer survivors from older breast cancer survivors. The findings of this study suggested that a systematic analysis of cancer survivors is needed to understand their unique health profiles and needs. Cancer 2006. © 2006 American Cancer Society.
Treatment of acute myelogenous leukemia with outpatient azacitidine
Authors: Sudan Nimit , Rossetti James M. , Shadduck Richard K. , Latsko Joan , Lech John A. , Kaplan Robert B. , Kennedy Margaret , Gryn Jeffrey F. , Faroun Yacoub , Lister John
Published: September 2006

BACKGROUND

Patients older than 55 years of age with acute myelogenous leukemia (AML) are less likely to achieve complete remission and more likely to experience toxicity with conventional induction chemotherapy than younger patients. Azacitidine administered in the outpatient setting is well tolerated and can induce complete hematological remission in patients with myelodysplastic syndromes (MDS). At higher doses, azacitidine has activity in AML.

METHODS

Twenty patients were retrospectively identified who had been treated with azacitidine with bone marrow blast counts between 21 and 38%. Patients with blast counts up to 29% were initially treated as MDS, but by WHO now meet criteria for AML. Patients with blast counts over 29% were treated with azacitidine after being deemed poor candidates for induction chemotherapy. Azacitidine 75 mg/m2/day was administered subcutaneously for 7 days every 4 weeks, which was defined as 1 cycle.

RESULTS

The overall response rate was 60% (12/20): complete response (CR; n = 4; 20%); partial response (PR; n = 5; 25%); hematologic improvement (HI; n = 3; 15%). The median survival of responders was 15+ months compared with 2.5 months for nonresponders (P = .009). During therapy, responders had an Eastern Cooperative Oncology Group (ECOG) performance status of 1 or 0. The most common toxic event was infection (n = 8). Four patients were hospitalized during the first cycle of treatment.

CONCLUSIONS

Azacitidine administered in the outpatient setting can induce remission in AML. The therapy is well tolerated and might be an alternative for patients unlikely to tolerate standard induction chemotherapy. Cancer 2006. © 2006 American Cancer Society.
Growth of cadmium zinc telluride by liquid phase electroepitaxy
Authors: Armour N. , Sheibani H. , Dost S.
Published: September 2006

This study was undertaken to examine the feasibility of growing CdZnTe by liquid phase electroepitaxy. Based on our successful LPEE system of GaInAs, a new crucible to grow CdZnTe was developed. The development presented numerous difficulties. The physical properties of CdZnTe make this material very difficult to grow. All components of the system were investigated. Electromigration of the solute across the solution carries species towards the growth interface. In liquid Cd‐Zn‐Te, the CdTe and ZnTe species remain associated, contrary to the GaInAs system. Experiments showed that LPEE growth of CdZnTe is possible and the electromigration mechanism functions well in the CdZnTe solution. Despite this, other problems remained with the new LPEE system. The preparation of the solution proved difficult without pressurizing the LPEE crucible. Control of the reaction required the use of pre‐compounded CdTe and ZnTe. Proper control of the solution saturation is imperative to ensure minimal dissolution of the seed prior to growth initiation and a reasonable growth rate during growth. The solution remained an issue during the duration of growth due to the high vapor pressures of the constituents. Tellurium evaporation during growth could lower solution volume until electrical contact across the solution is broken. Careful preparation of appropriate solution volume was imperative for successful growth. In LPEE, a uniform electric current passage across the growth interface is necessary for uniform and stable growth interface. This requires the design of a uniform contact zone between the bottom graphite electrode and the seed crystal. The contact zone issue was not adequately resolved in this study. However, a number of successful growth runs were achieved despite the electrical contact problems. Results show that the LPEE of growth CdZnTe is feasible. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)