bluuebunny/crossref_metadata_2025 huggingface dataset:
The 4.1 Protein Coracle Mediates Subunit-Selective Anchoring ofDrosophilaGlutamate Receptors to the Postsynaptic Actin Cytoskeleton
Authors: Chen Kaiyun , Merino Carlos , Sigrist Stephan J. , Featherstone David E.
Published: July 2005

GlutamatergicDrosophilaneuromuscular junctions contain two spatially, biophysically, and pharmacologically distinct subtypes of postsynaptic glutamate receptor (GluR). These receptor subtypes appear to be molecularly identical except that A receptors contain the subunit GluRIIA (but not GluRIIB), and B receptors contain the subunit GluRIIB (but not GluRIIA). A- and B-type receptors are coexpressed in the same cells, in which they form homotypic clusters. During development, A- and B-type receptors can be differentially regulated. The mechanisms that allow differential segregation and regulation of A- and B-type receptors are unknown. Presumably, A- and B-type receptors are differentially anchored to the membrane cytoskeleton, but essentially nothing is known about howDrosophilaglutamate receptors are localized or anchored. We identified coracle, a homolog of mammalian brain 4.1 proteins, in yeast two-hybrid and genetic screens for proteins that interact with and localizeDrosophilaglutamate receptors. Coracle interacts with the C terminus of GluRIIA but not GluRIIB. To test whether coracle is required for glutamate receptor localization, we immunocytochemically and electrophysiologically examined receptors in coracle mutants. In coracle mutants, synaptic A-type receptors are lost, but there is no detectable change in B-type receptor function or localization. Pharmacological disruption of postsynaptic actin phenocopies the coracle mutants, suggesting that A-type receptors are anchored to the actin cytoskeleton via coracle, whereas B-type receptors are anchored at the synapse by another (yet unknown) mechanism.
The ZebrafishshockedGene Encodes a Glycine Transporter and Is Essential for the Function of Early Neural Circuits in the CNS
Authors: Cui Wilson W. , Low Sean E. , Hirata Hiromi , Saint-Amant Louis , Geisler Robert , Hume Richard I. , Kuwada John Y.
Published: July 2005

shocked(sho) is a zebrafish mutation that causes motor deficits attributable to CNS defects during the first2dof development. Mutant embryos display reduced spontaneous coiling of the trunk, diminished escape responses when touched, and an absence of swimming. A missense mutation in theslc6a9gene that encodes a glycine transporter (GlyT1) was identified as the cause of theshophenotype. Antisense knock-down of GlyT1 in wild-type embryos phenocopiessho, and injection of wild-type GlyT1 mRNA into mutants rescues them. A comparison of glycine-evoked inward currents inXenopusoocytes expressing either the wild-type or mutant protein found that the missense mutation results in a nonfunctional transporter.glyt1and the relatedglyt2mRNAs are expressed in the hindbrain and spinal cord in nonoverlapping patterns. The fact that these regions are known to be required for generation of early locomotory behaviors suggests that the regulation of extracellular glycine levels in the CNS is important for proper function of neural networks. Furthermore, physiological analysis after manipulation of glycinergic activity in wild-type andshoembryos suggests that the mutant phenotype is attributable to elevated extracellular glycine within the CNS.
Development and Evaluation of the RZWQM‐CROPGRO Hybrid Model for Soybean Production
Authors: Ma L. , Hoogenboom G. , Ahuja L. R. , Nielsen D. C. , Ascough J. C.
Published: July 2005

It is common for agricultural system modelers to enhance their models by learning from other models and incorporating the best state‐the‐science into their models. In this study, the CROPGRO plant growth model of Decision Support System for Agrotechnology Transfer (DSSAT v3.5) was linked to the Root Zone Water Quality Model (RZWQM) to provide RZWQM users an option of using CROPGRO. In the hybrid model, RZWQM supplied CROPGRO with daily soil water and N, soil temperature, and potential evapotranspiration (PET), whereas CROPGRO supplied RZWQM with daily water and N uptake and plant growth variables. The RZWQM‐CROPGRO hybrid model was then evaluated against the original CROPGRO‐soybean model using several data sets from the literature. These data sets represented various drought conditions. Results showed that the RZWQM‐CROPGRO hybrid model simulated higher water stress than the original DSSAT‐CROPGRO model because of higher PET simulated by RZWQM, especially under semiarid climate conditions. Therefore, it was necessary to make some adjustments in the hybrid model under dry and windy conditions, e.g., using a different lower limit of plant available water as DSSAT. The hybrid model with a more detailed soil water balance calculation only affected soil water prediction at the top 60‐cm soil profile where soil water was more dynamic. This study demonstrated a successful linkage between RZWQM and CROPGRO, and the RZWQM‐CROPGRO hybrid model provides users with a tool to conduct detailed simulation of crop production in addition to addressing water quality concerns. This study also demonstrated that, when building models from various sources, compatibility of the interacting modules should be ensured.
Irrigation Management of Peanut with a Moving Sprinkler System: Runoff, Yield, and Water Use Efficiency
Authors: Plaut Z. , Ben‐Hur M.
Published: July 2005

Irrigation of peanut (Arachis hypogaea L.) with a moving sprinkler irrigation system (MSIS) could affect runoff, evaporation, and crop yield. The objective was to determine the effects of irrigation management on soil water withdrawal, runoff, peanut yield and quality, and irrigation water use efficiency (WUE). Peanut was grown in a commercial field on a loess soil that is sensitive to seal formation and runoff. Irrigations were applied once every 3 or 7 d during the vegetative stage, and each of these treatments was subdivided into three irrigation‐frequency treatments of 3, 7, and 10 d during the flowering and pod‐filling stages. The total water applied in the various irrigation treatments, based on the soil moisture deficit up to field capacity, ranged from 575 to 648 mm. The lower the irrigation frequency, the smaller was the amount of water applied. During the vegetative stage, irrigation every 3 d led to faster coverage of the soil surface by the peanut canopy and reduced the amount of runoff by 60 mm compared with irrigation every 7 d. Pod yields in the various treatments ranged from 602 to 651 g m−2, but the differences were statistically insignificant. Decreasing the irrigation frequencies during the vegetative and pod‐filling stages increased the WUE. Since peanut yield was insignificantly affected by the irrigation frequency, the enhanced WUE must have been due to reduced water losses during the irrigation season. The water saving through reduced runoff at the high irrigation frequencies may be canceled by higher losses through evaporation from the soil, interception by the canopy, and water removal by wind. One also has to consider the additional labor requirement and nonirrigating movements of the MSIS under high‐frequency irrigation management; these are factors that detract from the advantages of the MSIS.
An Algorithm for Calculating the Least Limiting Water Range of Soils
Authors: Leao Tairone Paiva , da Silva Alvaro Pires , Perfect Ed , Tormena Cassio Antonio
Published: July 2005

The least limiting water range (LLWR) is used to estimate the optimum soil water content for plant growth based on the range of bulk density values for a given soil series under evaluation. However, the use of this methodological approach by soil scientists has been limited by the lack of a detailed description of the statistical and mathematical procedures used for its calculation. This paper describes a Statistical Analysis System (SAS) algorithm for calculation of the LLWR from bulk density, volumetric water content, water potential, and soil penetration resistance data. Since nonlinear regression techniques are used, a brief description of the theory involved in this type of statistical analysis is presented. To improve the visualization and interpretation of the LLWR results, a plotting subroutine is also described. Five soils with different textures and management conditions were used to validate the algorithm. Statistical comparison with previously published LLWR calculations showed that the new method is reliable and accurate and can substantially reduce the time and labor necessary to estimate the LLWR of soils.
Response of Maize and Soybean to Variability in Stand Uniformity
Authors: Andrade Fernando H. , Abbate Pablo E.
Published: July 2005

The literature indicates variable results in response to uneven stands. We tested the hypothesis that the effect of uneven stands on grain yield varies depending on the vegetative and reproductive plasticity of the species and cultivars. Treatments consisted of a uniform control, nonuniform plant spacing between plants, and uneven seedling emergence. For maize (Zea mays L.), average yield per plant (Yp) decreased 0.68 g for every unit increase in percentage coefficient of variation (CV) for vegetative biomass per plant (Vp). Contrarily, soybean [Glycine max (L.) Merr.] Yp was not affected by increments in plant size variation. A model based on the relationship between Yp and Vp and on mean and CV for Vp was used to estimate the effect of nonuniformity on grain yield in maize and soybean cultivars. Based on these models and assuming constant average Vp with a normal frequency distribution throughout different stand uniformity treatments, increases in CV for Vp resulted in less grain yield in maize but not in soybean. Reductions in vegetative biomass produced further yield drops according to the specific relationship between Yp and Vp. The effect of unevenness in plant sizes on maize grain yield would depend on the characteristics of the hybrid. A stable hybrid is characterized by low decreases in Vp in response to heterogeneity, low threshold Vp for prolificacy and for grain yield, and a low curvature in the Yp/Vp relationship.
Natural Reseeding by Forage Legumes following Wheat in Western North Dakota
Authors: Carr Patrick M. , Poland Woodrow W. , Tisor Lee J.
Published: July 2005

Legume pasture is rotated with wheat (Triticum spp.) to enhance grain production sustainability. The legume species maintain or enhance wheat yield and regenerate from the soil seed bank. Our objectives were to determine: (i) grain yield when wheat followed legume forages and (ii) if legume species regenerated naturally following wheat in western North Dakota. Ten to 30 legume species were established in field experiments in 1999, 2000, and 2001. Legumes that regenerated or persisted in the second year were terminated chemically before seeding wheat in the third year. Plots were fallowed in the second year where legumes failed to regenerate or persist. Grain yield ranged from 1290 to 4100 kg ha−1 across the 3 yr when wheat followed yellow‐flowered sweetclover (Melilotus officinalis Lam.) and was equal or enhanced compared with fallowed plots where legumes did not reseed in 2 yr (P < 0.05). Grain yield never was enhanced and sometimes was reduced when wheat followed other legume forages compared with fallowed plots. Legume seedlings regenerated following wheat in birdsfoot trefoil (Lotus corniculatus L.) plots in all 3 yr, and forage production exceeded 3 Mg ha−1 in 2 yr. Other legume species failed to regenerate or produced less forage than birdsfoot trefoil in at least 1 yr. Birdsfoot trefoil has potential as a regenerating pasture species, but strategies are needed to enhance grain yield in legume–wheat rotations.
Effectiveness of RZWQM for Simulating Alternative Great Plains Cropping Systems
Authors: Anapalli Saseendran S. , Nielsen David C. , Ma Liwang , Ahuja Lajpat R. , Vigil Merle F. , Halvorson Ardell D.
Published: July 2005

The Root Zone Water Quality Model (RZWQM) is a comprehensive agricultural system model with the capacity to predict crop–environmental response to varying soil and crop management systems. Our objective was to evaluate RZWQM for its ability to simulate a 2‐yr winter wheat (Triticum aestivum L.)–fallow (WF) rotation and a more complex wheat–corn (Zea mays L.)–fallow (WCF) rotation under tilled and no‐till (NT) conditions on a Weld silt loam soil in semi‐arid northeastern Colorado. Measured data from all phases of both rotations were compared with simulated values using root mean square error (RMSE) values to quantify the agreement. Soil water in different layers, total soil profile (180 cm) water contents, and grain yield were accurately predicted with RMSEs ranging between 0.055 and 0.061 m3 m−3, 4.6 and 7.1 cm, and 244 and 867 kg ha−1, respectively. Leaf area index (LAI), evapotranspiration, and biomass predictions were less accurate with RMSEs between 0.7 and 1.6 cm2, 5.5 and 9.7 cm, and 1027 and 2714 kg ha−1, respectively. Greater soil water and crop yield measured for NT compared with conventional tillage (CT) were simulated reasonably well. Predicted soil organic C was greater in the surface 0.10 m for NT compared with CT after 11 yr. Although the crop growth component of RZWQM needs improvement, especially with regard to LAI, we conclude the model has potential for simulating alternative crop rotations in the central Great Plains. One potential application for RZWQM in this region may be to predict viable cropping opportunities for evolving conservation programs such as the Conservation Security Program (CSP).
General Recursion via Coinductive Types
Authors: Capretta Venanzio
Published: July 2005

A fertile field of research in theoretical computer science investigates the representation of general recursive functions in intensional type theories. Among the most successful approaches are: the use of wellfounded relations, implementation of operational semantics, formalization of domain theory, and inductive definition of domain predicates. Here, a different solution is proposed: exploiting coinductive types to model infinite computations. To every type A we associate a type of partial elements Partial(A), coinductively generated by two constructors: the first, return(a) just returns an element a:A; the second, step(x), adds a computation step to a recursive element x:Partial(A). We show how this simple device is sufficient to formalize all recursive functions between two given types. It allows the definition of fixed points of finitary, that is, continuous, operators. We will compare this approach to different ones from the literature. Finally, we mention that the formalization, with appropriate structural maps, defines a strong monad.
DNA
methylation in epigenetics, development, and imprinting
Authors: Sasaki Hiroyuki
Published: July 2005

DNA methylation is a key epigenetic mechanism that controls developmental gene expression, transposon silencing, and genome integrity. In vertebrates, methylation occurs at the cytosine of CpG dinucleotides, and this provides the basis for heritability of methylation patterns through replication. The DNA methyltransferases and methyl‐CpG‐binding proteins cooperate with chromatin modification enzymes to silence genes. Although some organisms such as yeast and nematode live happily without methylation, mammals are heavily dependent on it: loss of methylation in mice causes early embryonic death. Genomic imprinting, an epigenetic phenomenon crucial for normal mammalian development, is also controlled by methylation.
Rapidly evolving imprinted loci
Authors: Kim Joomyeong , Stubbs Lisa
Published: July 2005

Most imprinted genes are highly conserved, encoding proteins with similar structure and function in all mammals; some are even well conserved in nonmammalian vertebrates in which imprinting does not exist. These genes are likely to participate in well‐established pathways defining shared embryological and adult traits. However, certain imprinted genes vary in form, function, and tissue‐specific regulation in different mammalian species. One imprinted domain, located in human chromosome 19 and proximal mouse chromosome 7, is exceptional in that all of the resident genes are of this evolutionarily unstable type. Five of the six genes in this region encode SCAN‐ and KRAB‐containing
Kruppel‐
type zinc‐finger (ZNF) genes, and are therefore members of rapidly evolving, vertebrate‐specific gene families. The recent advent of these genes may help explain their unusual level of evolutionary instability. However, because of their predicted function as transcription factors, the lineage‐specific loss and divergence of these loci may have far‐reaching effects on development, morphology, and behavior that define distinguishing traits in different mammals.
Gene mapping, imprinting, and epigenetics
Authors: Strauch Konstantin
Published: July 2005

In this review, methods for linkage and association analysis are presented that take imprinting into account. This epigenetic factor is also known as the parent‐of‐origin effect. Here, it is described why it is important to adequately model imprinting in the context of gene mapping. Tests for linkage that account for imprinting are contrasted with tests for imprinting. Furthermore, the confounding between sex differences in recombination fractions and imprinting is mentioned, as well as how such confounding can be avoided in a mapping study.
Gene identification in common disorders: a tutorial
Authors: Goodarzi Mark O. , Rotter Jerome I.
Published: July 2005

The task of identifying genes that predispose to common disorders presents unique challenges because, unlike rare genetic disorders, a number of genes may contribute to a common condition, each gene with a mild/moderate effect. This necessitates the study of large cohorts of subjects and families with and without the disorder of interest. These studies must establish the inherited nature of the condition, using a precise and reproducible method of defining the disorder. Intermediate phenotypes, thought to represent the earliest stages of the condition, may also prove useful in identifying genetic determinants in those at risk, as well as to subclassify affected individuals. In the past, linkage and association studies relied heavily on the use of single nucleotide polymorphisms and microsatellites as genetic markers; currently, interest is growing in the use of haplotypes, which are collections of marker alleles inherited together on a chromosome. By providing coverage across large regions of the genome, haplotypes may increase the ability to identify genetic determinants.
The microdeletion syndromes
Authors: Hoffman Jodi D. , Zackai Elaine H.
Published: July 2005

The microdeletion syndromes are a group of multiorgan system genetic disorders due to noncytogenetically visible deletions. This article discusses the details of a patient with a microdeletion syndrome and how to approach other such patients.
Single molecule array‐based sequencing
Authors: Bennett Simon T. , Smith Tony J.
Published: July 2005

Single molecule array‐based sequencing permits simultaneous analysis of potentially hundreds of millions of single molecules of DNA per cm
2
in an array‐based format. In this massively parallel approach to DNA sequence acquisition, reagents are utilized in an extremely efficient manner to achieve unprecedented levels of cost reduction and increased throughput. Ultimately, single molecule array (SMA)‐based sequencing will enable analysis of individual whole human genomes in a single experiment.
UsingESTsfor genome annotation – predicting the transcriptome
Authors: Eyras Eduardo
Published: July 2005

Expressed sequence tags (ESTs) provide a quick and cost‐effective way to obtain information about the collection of expressed genes in a genome. They can also provide information about the expression of genes, alternative splicing, polymorphisms, and untranslated regions, complementing other standard methods of annotation and ab initio gene prediction. Here we describe some of the advantages and problems of the usage of ESTs for genome annotation, emphasizing their utility for describing alternative splicing.
Expression and localization of proteins in mammalian cells
Authors: Stow Jennifer L. , Teasdale Rohan D.
Published: July 2005

The transfer of genes and expression of recombinant proteins is one of the main methods for discovery in the quest for understanding as biology moves from genomes through to proteomes, and finally to working cells and organisms. The techniques and tools for the transfer and engineering of genetic material and for the detection and analysis of expressed proteins are evolving rapidly alongside the burgeoning databases they have to explore. Physical, chemical, and biologically based vectors increasingly enable gene transfer into mammalian cells for research and therapeutic purposes. The emergence of fluorescent protein tags now allows sophisticated tracking and functional analysis of expressed proteins. In this review, we summarize the methods and scientific tools contributing to this technology. Finally, the push is on to develop high‐throughput and computational methods for large‐scale protein expression, localization, and analysis, and here we set the stage by providing updates on the coming technology in these fields.
The promise of gene signatures in cancer diagnosis and prognosis
Authors: Sung Jimmy C. , Lee Alice Y. , Yeatman Timothy J.
Published: July 2005

Gene‐expression profiling is a relatively new technology that has promise for developing mathematical models that might be useful in predicting diagnoses and prognoses for a number of different cancer types. While the promise of this approach has not yet been realized, there is accumulating evidence that this approach is feasible. Extensive validation of all molecular classifiers with large independent test sets will be necessary prior to clinical application.
Protein microarrays as an emerging tool for proteomics
Authors: Qiu Ji , Hanash Sam
Published: July 2005

The emerging technology of protein microarrays has a far‐reaching potential to meet the needs for measuring not just the abundance of protein constituents but also their functional states and their interactions with other biomolecules, with the requisite high throughput and high sensitivity. While protein microarrays still present some challenging problems, recent progress makes it likely that it will be possible soon to interrogate proteins at a proteome scale, using protein microarrays, analogous to DNA microarrays, thus making a substantial impact on biomedical research.
Seven years of yeast microarray analysis
Authors: Sherlock Gavin , Spellman Paul T.
Published: July 2005

Since the advent of microarray technology in the mid‐1990s, and finishing of the complete genome sequence of the yeast
Saccharomyces cerevisiae
in 1996, yeast has been at the forefront of genomic biology. In this article, we review the uses of microarrays to investigate yeast biology, and the wide range of applications that they have been used for. While, typically, people think of microarrays for generating large‐scale expression measurements, we discuss several different experimental approaches that have used microarrays to probe almost every facet of a living yeast cell.
Small molecule fluorescent probes for protein labeling and their application to cell‐based imaging (including
Fl
As
H
etc.)
Authors: Cass Tony
Published: July 2005

The fluorescent imaging of live cells has benefited tremendously from the development of new types of highly specific protein reagents. Three broad approaches to introducing fluorescent proteins into live cells have been described; ex vivo labeling followed by the introduction of the labeled proteins into cells, heterologous expression of inherently fluorescent proteins as fusions to other proteins and heterologous expression of a tagged protein followed by labeling with a reagent that reacts specifically with the tag. This last approach will be the subject of this review, and both the principles of the method and some applications will be described.
History and future of
X
‐ray structure determination
Authors: Jaeger Joachim , Dennis Caitriona
Published: July 2005

Single crystal X‐ray diffraction was first applied at the beginning of the twentieth century and to this day remains the most commonly used and highly productive technique to elucidate macromolecular structures at the atomic level. Recent developments in the theoretical background and in computational methods, dramatic improvements in experimental designs of synchrotron beamlines and insertion devices, and technical advances in high‐throughput methods combined with robotics have had a major impact on the analysis of macromolecular structure. Combination of cryogenic imaging techniques (EM) with multidimensional NMR, X‐ray, and electron diffraction studies will lead to unprecedented, new insights into the structure–function relationships of biological macromolecules.
Repeatfinding
Authors: Sucgang Richard
Published: July 2005

Finding repeats in biological sequences is a necessary first step in recognizing patterns and biologically relevant motifs. Given the inexact nature of biological repeats, the software required to detect, identify, classify, and curate them have grown not only in variety but in sophistication as well, accommodating increases both in amount of data and available computing power. Open source and free‐for‐academic‐use programs implementing repeat finding algorithms, as well as databases that curate known biological repeat motifs are surveyed in this section.
Algorithms for sequence errors
Authors: Andersson Björn , Tammi Martti T.
Published: July 2005

There are many obvious reasons why we would want to use error‐free DNA sequence data. For example, computer assembly of sequence fragments would be algorithmically much simpler and the cost of genome sequencing would be lower, since less sequence redundancy would be required. Unfortunately, we cannot get perfect data, but we can measure the accuracy of the sequence. The accuracy measures or error probabilities help us correct sequence data.
Measuring evolutionary constraints as protein properties reflecting underlying mechanisms
Authors: Neuwald Andrew F. , Liu Jun S.
Published: July 2005

Selective constraints are revealed in protein multiple sequence and structural alignments as conserved residues and corresponding atomic interactions. These patterns of conservation contain implicit information about underlying protein mechanisms, just as crystalline X‐ray diffraction patterns contain implicit information about a protein's structure. Contrast hierarchical alignment and interaction network (CHAIN) analysis measures and characterizes selective constraints on the basis of co‐conserved patterns and fits mechanistic models to these and other constraints. Just as the quantity and quality of X‐ray diffraction patterns determines how well one can fit an atomic model to the inferred electron density, the quantity and quality of co‐conserved patterns determines how well one can fit possible mechanisms to these inferred constraints. In principle, given sufficient data, biological mechanisms may be identified with high certainty. Nevertheless, even at “low resolution”, this information can prune the possibilities down to a manageable number for further experimental follow‐up.
Silicon Compounds: Anthropogenic Silicas and Silicates
Authors: Falcone James
Published: July 2005

Synthetic akali silicates, M2O·mSiO2·nH2O, where M = Li, Na, and K, are manufactured as liquids or glasses that readily dissolve in water to form alkaline solutions. These silicates contain a complex mixture of polymeric species that vary as a function of modulus,m, of the material, solution concentration, impurities content, and pH value. The polymer chemistry of silicates influences the properties and function of these materials in a variety of applications including detergency, water treatment, mineral beneficiation, bleach stabilization, and as a raw material for the syntheses of silica sols, gels and precipites, zeolites, clays, and other siliceous materials. The speciation and structure of silicates have been studied using a broad variety of analytical methods including Fourier transform infrared, ft–nmr, laser Raman, and X‐ray photoelectron spectroscopic techniques. The current article discusses the properties of the synthetic alkali silicates that determine their function in a variety of commercial applications. Economic, manufacturing, regulatory and environmental aspects of silicate production and usage are reviewed.
The Drainage: Impacts, Plant Growth, and Water Table Levels
Authors: Madramootoo Chandra
Published: July 2005

Every soil has some degree of natural drainage. However, if the rates of precipitation or irrigation exceed the natural drainage rate of the soil, the high water table conditions will impair crop growth, because of a lack of oxygen in the root zone. Artificial, or tile drainage, is therefore required to remove excess soil water and to lower the water table, to maintain an optimum soil–air environment within the crop root zone. Most of the world's highly productive agricultural soils require either surface drainage or tile drainage, or a combination of both, to maintain stable crop yields. It is estimated that there are about 200 million hectares of cropland worldwide with improved drainage.
Pesticide Chemistry in the Environment
Authors: Miglioranza Karina S.B. , Gonzalez Mariana , Aizpún De Moreno Julia E. , Moreno Víctor J.
Published: July 2005

The use of pesticides has resulted in increased crop production but also raised concerns about potential adverse effects on the environment. The knowledge of pesticide environmental behavior, like soil adsorption, leaching, and volatility, is necessary to asses the risk to the environment and humans. The properties of pesticides, such as herbicides, insecticides, and fungicides, combined with the amount applied, determine how many pesticides can be transported along each route into the environment. Among insecticides, the monitoring of organochlorine pesticides (OCP) with low water solubility and high environmental persistence is highly recommended. Field studies determined that soil characteristics, topographic position, and land uses influence in OCP accumulation. The accumulation pattern represent a dynamic balance between deposition and erosion in association with wind‐induced circulation, tillage management practices, and effects by natural processes, such as rainfall and flooding periods, according to different soils. Moreover, the use of pesticides on agricultural land may have a negative effect on nearby aquatic ecosystems. This effect is determined by the specific chemicals used, the place and methods of application of the chemicals, and the various mechanisms available for transporting compounds to the waterbodies, with soil erosion being a major pathway. Hydrophobicity and persistence are the main properties of pesticides that control their accumulation in sediment and aquatic biota. Thus, this fact confirms the current necessity of OCP monitoring in natural areas.
Water Pollution from Fish Farms
Authors: Bergheim Asbjørn , Brinker Alexander
Published: July 2005

Wastes from aquaculture plants include all materials used in the process that are not removed from the system during harvest. The principle wastes from aquaculture are uneaten feed, excreta, chemicals, and therapeutics. In addition, the term “waste” can also refer to pathogens and dead or escaped fish.

Generally, the quantity of waste is closely connected to the culture system used.
Intensive
farm systems, typically monoculture of carnivorous finfish in the temperate zone reliant on artificial feed, may cause serious local pollution. So‐called semi‐intensive farm systems are supplied natural feed sources, such as vegetation, oil cakes, cereal bran, and organic‐chemical fertilizers. The latter systems dominate the tropical/subtropical production of herbivorous or omnivorous fish, e.g., the major production of carps and tilapia, and the waste output to the surrounding waters is much lower than from intensive fish farms.
Deep‐Well Turbine Pumps
Authors: Hanson Blaine
Published: July 2005

Deep‐well turbine pumps are used to pump groundwater. They consist of a housing or bowl, impellers, and a shaft, all of which are installed in the well. Impeller types include closed and semi‐open impellers. Submersible pumps are a modification of deep‐well turbines for which the electric motor is installed in the well, instead of at the ground surface. Performance curves, developed by pump manufacturers, describe relationships between total head and capacity, pump efficiency and capacity, and horsepower demand and capacity. These curves can select new pumps and evaluate existing pumps. A common cause of declining pump efficiency with time is wear caused by sand in the pumped water.
Nitrate Pollution Prevention
Authors: Maticic Brane
Published: July 2005

Groundwater and springwater are sources used for water supply in many countries. The pollution of surface and groundwater is caused mostly by the chemicals used in industry, urban wastes, and agriculture. The pollution of groundwater by nitrates, as well as the pollution of crops that we consume, is one of the most serious environmental concerns in most countries. Drinking water and eating vegetables with high amounts of nitrate and nitrite are toxic, especially for children and babies. It is not nitrate that is toxic, but the compounds derived from it, nitrites and nitrosamines.

To identify nitrogen surpluses (that may influence pollution of groundwater and surface waters) due to agricultural technology used in different countries, it is advisable to demonstrate a “mineral (nitrogen) balance” on regional and farm levels using a normative approach. In the most intensive arable region with a high intensity of animal husbandry (>2 LU/ha), nitrate surpluses are supposed to be found in the soil, crops and groundwater. These regions can be identified as vulnerable for nitrogen leaching into groundwater. In regions with limited growing conditions for agricultural plants (climate, soil depth), a small increase in livestock density can cause high nitrogen surpluses (karst regions).

To reduce mineral (nitrogen) surpluses in agriculture and to meet the standards of nitrate and nitrite in drinking water and crops, it is necessary to control water and food quality in connection with nitrates and nitrites and to exact certain regulations regarding change in agriculture, especially animal excrement management.

The regulations should give and follow different norms such as: the maximum allowed intensity of raising animals, proper timing for the application of organic manure on soil, the highest quantities of mineral fertilizers allowed per hectare, and suitably built dung yards and cesspools.

When the world is going through many changes regarding exploitation of its natural resources and environmental protection, new ideas for efficient and sustainable water management of agricultural land are very important to protect the quality of groundwater and water in rivers, as well as crops that we consume.
Biofuel Alternatives to Fossil Fuels
Authors: Reijnders Lucas
Published: July 2005

There is increased advocacy for replacing fossil fuels by biofuels by using advanced conversion technology. Increased use of biofuels has direct and indirect effects on water. Indirect effects are mediated by the impact of biofuels on climate. Specific biofuels may be linked to quite different inputs of fossil fuels, and effects on biogenic carbon stocks and are not necessarily “climate neutral.” Availability of water may be a limiting factor in biofuel production, making water efficiency an important matter. Peak flows, storm flows, and groundwater levels may be influenced by biofuel crops. The biofuel life cycle may mobilize large amounts of substances that may impact water. Biofuel crop production may be associated with silting, downstream channel instability, and increased concentrations of minerals and plant nutrients in surface water. Biofuel life cycle emissions of acidifying substances, persistent organic pollutants, heavy metals, and other hazardous elements may be significant. There are measures to limit the impact of substances mobilized during the biofuel life cycle.
Media Filters for Microirrigation
Authors: Haman Dorota Z.
Published: July 2005

Media (sometimes called sand) filters are well suited for removal of either organic or inorganic particles. Due to their three‐dimensional nature, media filters have the ability to entrap large amounts of contaminants. They do not seal off as easily and therefore will not clog as often as filters that trap particles on their surface, such as screen filters. Media filters consist of fine gravel and “sand” (that actually is crashed granite or silica) of selected sizes placed in pressurized tanks. The main body of the tank contains sand, which is the active filtering ingredient. The sand is placed on top of a thin layer of gravel that separates it from an outlet screen. Sharp‐edged sand or crushed rocks are recommended for the filtering media since the corners catch soft algal tissue. Crushed granite or silica graded into specific sizes for a particular system are commonly used porous media. Media filters are cleaned by backwashing. This operation consists of reversing the direction of water flow in the tank. Automatic back flush systems will eliminate sudden changes in water quality that can create problems if a filter is washed only at regular intervals.
Classification and Mapping of Agricultural Land for National Water‐Quality Assessment
Authors: Gilliom Robert J. , Thelin Gail P.
Published: July 2005

The U.S. Geological Survey's (USGS) National Water‐Quality Assessment (NAWQA) Program is designed to describe the status and trends in the quality of the nation's ground‐ and surface‐water resources and to link the status and trends with an understanding of the natural and human factors that affect the quality of water. The program integrates information about water quality at a wide range of spatial scales, from local to national, and focuses on water‐quality conditions that affect large areas of the nation or occur frequently within small areas.
Soil Conservation
Authors: Rickson R. J. , McHugh M. , Morgan R. P. C.
Published: July 2005

Soil is a precious natural resource, which performs many vital functions. As a growing medium, soil provides nutrients, air, and water to sustain life on earth, supporting global agricultural and manufacturing industries with renewable raw materials, enabling sustainable economic growth and prosperity. As a habitat, soil is an essential gene reservoir, maintaining a healthy biodiversity that enables micro‐ and macroorganisms to adapt successfully to environmental changes. Soil influences our natural and cultural landscapes by providing the foundation and raw materials for infrastructure, thus affecting the aesthetics of the world around us. Soils have enormous storage capacity, absorbing surface water, which helps to reduce flooding risk, and providing water supplies for agricultural, domestic, and industrial demands. Soil filters the water passing through it, and chemical transformations help neutralize potentially harmful substances. Soils also store nutrients, trace elements, and organic carbon. Soils are essential in the sequestration of carbon and in the absorption, storage, and reflection of solar energy—important processes that influence global climate and climate change.
Soil
N
Management Impact on the Quality of Surface and Subsurface Water
Authors: Sarkar Dibyendu , Vandanapu Vandana , Datta Rupali
Published: July 2005

Nitrogen (N) in the forms of nitrate or ammonium is a nutrient needed for plant growth. When the amount of soil‐supplied N is considered deficient for satisfactory crop yields, N fertilizer is added to supplement the soil‐supplied N. If N is supplied in excess of crop needs, a surplus is created that can cause significant water quality problems. Until recently, the main reason for investigations into the forms of N in soil systems below the rooting depth of plants was to evaluate the loss of nitrate to crops and to estimate the loss of production. In recent years, much attention has been focused on forms of N as potential pollutant sources of both groundwater and surface water. Nitrate concentrations above a certain level in drinking water may have critical health effects on animals and human infants. Alternately, N can also contribute to surface water contamination via surface water runoff and erosion. Excessive nitrate concentrations in surface water bodies, such as streams or lakes, can accelerate algae and plant growth, resulting in oxygen depletion. Nitrogen must be managed properly to protect water quality. Best management practices (BMPs) are methods that are the most effective, practical means of preventing or reducing nutrient pollution from nonpoint sources. Nitrogen BMPs primarily involve a change in fertilizer management practices, such as changing the timing, placement method, and/or the amount of fertilizer applied to reduce the possibilities of contaminating water resources. In addition, conservation tillage practices, cover crops, and crop rotation all help reduce surface runoff, erosion, and leaching of soil N. It is imperative to continue the development and implementation of new and effective management practices that increase N recovery and reduce potential N losses to the environment.
Waterlogging
Authors: Gupta Suresh K.
Published: July 2005

In its simplest form, waterlogging connotes congestion of drainage whether surface or subsurface. According to Webster's dictionary, waterlogging has been defined as follows: to saturate with water, as to waterlog soil by allowing stagnant water to stand on it; waterlogged, rendered soggy and unfit to till by water in excess of soil. Clayton has defined a land as waterlogged when the water table is within ±150 cm of the natural surface. A definition adopted in 1925 by the state of Punjab (India) designated land as waterlogged if it is thrown permanently out of cultivation due to a rise in subsoil water and is recorded asbanjar(barren) in the revenue records.
Water Spreading
Authors: Arasteh Peyman Daneshkar
Published: July 2005

Runoff farming is one of the most common techniques to supply some part of irrigation water in arid and semiarid areas of the world. For runoff farming, because of the lack of normal water supply, water harvesting techniques must be used, and one of these water harvesting methods is floodwater spreading. When rainfall intensity is more than infiltration and other catchment abstractions, surface runoff has occurred, and when the catchment natural waterways have a capacity less than runoff, flood has occurred. Flood spreading is a method to control the risks and hazards of floods, groundwater recharge, crop production, etc. In this article, flood spreading is mentioned as an irrigation method, and some aspects of the history of floodwater spreading, some design criteria, and some suitable references for designation of the system are introduced.
Domestic Solar Water Heaters
Authors: Smyth Mervyn
Published: July 2005

Solar water heating systems convert solar radiation into useable thermal energy in the form of hot water. Domestic solar water heaters can provide households with a large proportion of their hot water needs while reducing the amount of conventional fuel used and hence reducing home energy costs. The amount of hot water produced will depend on the type and size of the system, the climate, and location for solar access. Over the years, a variety of system designs have been developed and tested to meet specific consumer needs and environmental conditions.

Domestic solar water heaters can be categorized as being either active or passive and can be further grouped according to the configuration of the main solar water heating components: integral or distributed. Integrated systems combine the collector and storage functions in a single unit, whereas distributed systems have a separate solar collector and hot water store connected by a piping network. Distributed systems can be either active or passive. In active systems, a pump circulates the transfer fluid between the collector and the store. Integrated systems are almost always passive as they do not require external power.
Water Reuse
Authors: Cartwright, P.E. Peter S.
Published: July 2005

Water reuse
is the general term applied to the act of recovering water from a process and reusing it in the same process, or another one, before discharging it. Some experts attach labels to this activity based on the specific use of the water:
Recycle
involves redirecting the recovered water back to the same process.
Reuse
means reusing the recovered water in a different application.
Recovery
generally refers to the technologies used to accomplish this.
Household Drinking Water Treatment and Safe Storage
Authors: Murcott Susan
Published: July 2005

Household water treatment is the decentralized treatment of drinking water in the home and safe storage is the protection of drinking water in specially designated household storage vessels.

Even for the 50% of people worldwide with a tapped water supply, safety is not always assured. In such homes, household treatment units improve the aesthetics and/or remove harmful contaminants. Homes lacking a tapped drinking water supply are more likely to bear the burden of water‐related illnesses: 3.4 million deaths are water related; 1.4 million children die annually of diarrhea—the third highest cause of illness and sixth highest cause of mortality globally; and 1.1 billion—or about one in six people globally—lack access to improved drinking water.

For these people, household water treatment and safe storage may be their main barrier in the prevention of water‐related illnesses, and evidence shows that household treatment and safe storage systems are capable of dramatically improving the microbial quality of drinking water and reducing diarrheal and other water‐related diseases and death.

In the decade to come, we will witness innovation and scale‐up of these systems from hundreds to thousands to millions to meet the enormous global need for clean drinking water.
Corrosion Control in Drinking Water Systems
Authors: Volk Christian J.
Published: July 2005

Drinking water distribution systems are primarily composed of iron and steel pipes or other metallic pipes that are subject to corrosion. Various metals, such as lead, copper, zinc, cadmium, and iron, may be present in water when metals corrode in the water systems. Depending on water quality, the source water either causes corrosion or deposition of a film on pipes and plumbing fixtures. Corrosion of distribution system pipes has economic, hydraulic, and aesthetic impacts including water leaks, corrosion product buildup, increased pumping cost, and water quality deterioration. Corrosion of iron is also the primary factor for controlling bacteria growth. Many systems have to provide corrosion control to comply with the federal and state regulations enacted to protect consumers from health dangers of lead and copper in drinking water. This article provides an overview of corrosion in the distribution system, factors impacting corrosion, corrosion measurement, and the need for corrosion control.