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Increasing global reliance on stormwater control measures to reduce discharge to surface water, increase groundwater recharge, and minimize contaminant delivery to receiving water-bodies necessitates improved understanding of stormwater—contaminant profiles. A multiagency study of organic and inorganic chemicals in urban stormwater from 50 runoff events at 21 sites across the United States demonstrated that stormwater transports substantial mixtures of polycyclic aromatic hydrocarbons, bioactive contaminants (pesticides and pharmaceuticals), and other organic chemicals known or suspected to pose environmental health concern. Numerous organic-chemical detections per site (median number of chemicals detected = 73), individual concentrations exceeding 10 000 ng/L, and cumulative concentrations up to 263 000 ng/L suggested concern for potential environmental effects during runoff events. Organic concentrations, loads, and yields were positively correlated with impervious surfaces and highly developed urban catchments. Episodic storm-event organic concentrations and loads were comparable to and often exceeded those of daily wastewater plant discharges. Inorganic chemical concentrations were generally dilute in concentration and did not exceed chronic aquatic life criteria. Methylmercury was measured in 90% of samples with concentrations that ranged from 0.05 to 1.0 ng/L., Graphical Abstract

This article examines some of the key points attributed to the Liberal Reform of 1857 as they appeared in the debate over immigration policy in Mexico from 1836 to 1855. It argues that many of the key provisions of reform that are attributed to the radical Liberals of 1857 were, in fact, part of a more broad-ranging and moderate debate for decades before. In this manner, immigration policy debates often served as a “test balloon“for what would later be defined as the essential points of liberalism.

Natural attenuation of an acidic plume in the aquifer underneath a uranium mill tailings pond in Wyoming, USA was simulated using the multi-component reactive transport code phreeqc . A one-dimensional model was constructed for the site and the model included advective–dispersive transport, aqueous speciation of 11 components, and precipitation–dissolution of six minerals. Transport simulation was performed for a reclamation scenario in which the source of acidic seepage will be terminated after 5 years and the plume will then be flushed by uncontaminated upgradient groundwater. Simulations show that successive pH buffer reactions with calcite, Al(OH) 3 (a), and Fe(OH) 3 (a) create distinct geochemical zones and most reactions occur at the boundaries of geochemical zones. The complex interplay of physical transport processes and chemical reactions produce multiple concentration waves. For SO 4 2− transport, the concentration waves are related to advection–dispersion, and gypsum precipitation and dissolution. Wave speeds from numerical simulations compare well to an analytical solution for wave propagation.

Mineralogical compositions and their spatial distributions are important initial conditions for reactive transport modeling. However, popular Kd-based “reactive” transport models only require contaminant concentrations in the pore fluids as initial conditions, and minerals implicitly represent infinite sources and sinks in these models. That situation results in a general neglect of mineralogical characterization in site investigations. This study uses a coupled multi-component reactive mass transport model to predict the natural attenuation of a ground water plume at a uranium mill tailings site in western USA. Numerous ground water geochemistry data are available at this site, but mineralogical data are sketchy. Even given the well-defined pore fluid chemistry, variations of secondary mineral species and mineral abundances in the aquifer resulted in significantly different modeling outcomes. Results show that the amount of calcite in the aquifer determines the distances of plume migration. The possible presence of jurbanite, an aluminum sulfate phase, can store acidity temporarily but cause more severe contamination on a later date. The surfaces of iron oxyhydroxides can store significant amounts of sulfate and protons and serve as a second source for prolonged contamination. These simulations under field conditions illustrate that mineralogical compositions are an essential requirement for accurate prediction of contaminant fate and transport.

The sequence of nucleotides within a DNA molecule can yield a wealth of information. Important biological features such as amino acid sequence, exact amino acid composition, and gene structure are contained within sequences. The data can be used for highly specific manipulations of cloned DNA, such as changing a single nucleotide, substituting promoters between genes, and fusing of genes to yield hybrid (heterologous) proteins. Probes can also be designed for a variety of uses, including the detection of genetic diseases and pathogenic microbes.

Before anything can be constructed, it is first necessary to gather the building materials, and, therefore, harvesting genomic DNA is a prerequisite for cloning. Normally two types of DNA are required for cloning, namely, the source DNA containing the targeted gene (that which is to be cloned), and the vector (a DNA molecule that carries the target). The source or genomic DNA can be from any organism or DNA virus. The vector, on the other hand, is a specially designed DNA molecule derived from either a bacteriophage, a plasmid, or some combination of both. As we shall see, the vector will serve as a carrier for the genomic DNA fragments.

Cloning a gene is similar to finding a needle in a hay stack. A gene, even in the simplest of organisms, represents only a tiny fraction of the DNA in a genome (all the genetic information in the cell). A typical scheme for cloning involves removing the genomic DNA from a donor, breaking the DNA into many thousands of small pieces, and then searching those pieces for the desired gene. The search is accomplished by using molecular probes that adhere specifically to the targeted gene.

Cloning involves isolating, fragmenting, and combining genomic DNA with a vector, followed by introducing the recombinant molecule into a host where it is replicated. The genomic DNA used in cloning is predominantly chromosomal which is large and fragile (i.e., large polymers break). By necessity, the DNA must be broken into manageable pieces, a process normally accomplished by DNA cleaving enzymes called restriction endonucleases. After the DNA is fragmented, the pieces are linked to a vector to form recombined or recombinant molecules. This population of different genomic fragments linked to vector molecules is called a gene bank or gene library.

The initial step in protein isolation from its source is to physically or chemically disrupt the biological tissue or organism in order to release the protein into the extract. In some cases, the organism secretes the protein, and cell disruption is unnecessary. The protein is usually produced in dilute concentration so it is advantageous if the initial isolation also results in the concentration of the protein. An important feature in any isolation procedure is product yield with the goal being to extract as much of the desired protein as possible in a minimum amount of time.

Once E. coli is transformed with a ligation mixture, the task of identifying the desired clone follows. Depending on the DNA source, tens to hundreds of thousands of clones may be screened before the target is identified. As we explored in Chapter 7, the strategy used in the cloning process will determine the amount of work required to identify that clone.

Introductory biology texts often present the biologist as a naturalist, such as Darwin or Lamark, who through careful observations develops theories and draws conclusions about living organisms. Originally these scientists kept biology and its subtopics as pure areas of study and resisted the multidisciplinary nature of modern science. For instance, in the 1830s Cagniard de Latour and von Liebig argued that fermentation was a biological phenomenon, not chemical. At this time biochemistry had yet to evolve, and the notion that biology and chemistry overlapped had not been fully realized. As the biology of the cell was discovered, several different scientific disciplines found it necessary to communicate in order to answer questions. In 1953, for instance, the structure of DNA was elucidated only after Watson and Crick pooled the information produced by biologists, chemists, and physicists. Since that time, the various scientific disciplines have continued to actively interact. However, it wasn’t until the 1970s and 1980s that biology and business wholeheartedly converged to produce today’s biotechnology industry.

Following the removal of the gross contaminants from the crude extract, the remaining protein components must be resolved. The most popular and ubiquitous technique for this separation is column chromatography. Similar to batch purification, column chromatography utilizes chemical and biological properties of the protein for its purification, but produces greater resolution.

The analysis of a protein is usually an attempt to characterize its structure and/or determine its degree of purity. Proteins of unknown structure are purified to apparent homogeneity and then analyzed to determine structure. The success of the structural analysis is, of course, critically dependent on the level of purification achieved.

The obvious first step in biochemical research is the discovery of some interesting biological activity followed by efforts to determine what type of biomolecule is responsible for that activity. The next few chapters in this book will deal with some of the issues that arise when the molecule of interest is a protein that must be purified and characterized prior to cloning the associated gene.

The range of different techniques used in the biotechnology laboratory is vast, and as demonstrated by the experiments of the previous thirteen chapters, can cross through many disciplines. Any one researcher can easily be expected to perform every task presented in this manual, from making agar plates to analyzing sequence data on a computer. As a person becomes more experienced in a chosen area of research, his or her repertoire of skills increases far beyond those presented in this manual. However, the skills presented here are the base upon which other abilities are built.

A crude protein extract derived from some type of physical or chemical manipulation of a source will typically contain several types of contaminating biomolecules. These contaminants can include carbohydrates, lipids, nucleic acids, proteins, salts, and other cellular debris. The separation of the protein fraction of the extract from these contaminants is usually referred to as the capture step and is typically performed early in the purification process. The desired protein is then separated from the other captured proteins in subsequent steps using higher resolution purification techniques.

It is necessary to clone DNA prior to its molecular analysis and subsequent manipulation and application. Once cloned, its characteristics such as fragment size, restriction sites, nucleotide sequence, and subsequence identification (biologically significant sequences) are forthcoming.

The construction of a gene bank is only part of the cloning process. To clone DNA, the recombinant molecules must be introduced into an organism in which they are replicated, and as the cell grows and divides, also propagated. In genomic cloning, the recombinant DNA is normally introduced into the bacterium Escherichia coli.

On oral administration, the non-selective beta-adrenoceptor blocking drugs (+/-)-bufuralol, (-)-bufuralol, propanolol, oxprenolol, pindolol and alprenolol produced hypotensive responses in the conscious cat; (+)-bufuralol was without effect. The selective beta-adrenoceptor blocking drugs practolol and atenolol had no effect on blood pressure but tolamolol elicited a hypotensive response. All the drugs tested reduced the tachycardia due to intravenous isoprenaline in the conscious cat; however, not all doses of these drugs reduced blood pressure. (+)-Bufuralol was devoid to beta-adrenoceptive blocking activity. Only tolamolol reduced the pressor response to i.v. phenylephrine in the conscious cat, indicating that alpha-adrenoceptive blocking activity may contribute to its hypotensive action. The results suggest that beta-adrenoceptive blocking activity is necessary for the hypotensive responses of these drugs. However, for the different drugs, there was no correlation between peripheral beta-adrenoceptive blocking activity and hypotensive response.

A series of 4-substituted phenoxypropanolamines was prepared and examined for beta-adrenoceptor activity. Some of the compounds, especially the [4-[2-[[2-(4-fluorophenyl)ethyl] oxy]ethoxy]phenoxy]propanolamines (14, 15, and 24), showed potent beta 1-blockade with virtually no beta 2-blockade at doses over a 1000 times greater. The compounds also possessed partial agonist activity. Structure-activity relationships are discussed, and conclusions are drawn about the binding sites on beta-adrenoceptors.

This paper presents a modeling analysis of the geochemical evolution of a contaminated sandy aquifer at a uranium mill tailings site in the western United States. The tailings pond contains fluids having a pH of 1.5 to 3.5 and high levels of As, Be, Cd, Cr, Pb, Mo, Ni, Se, 226Ra, 228Ra, 230Th, 238U, and 234U. Seepage of tailings fluids into the aquifer has formed a low-pH ground water plume. The reclamation plan is to install a low-permeability cover on the tailings pond to stop the seepage and allow the plume to be attenuated by reactions with the aquifer matrix and flushed by uncontaminated upgradient ground water. To evaluate this reclamation scenario, ground water and sediment core samples were analyzed along one flowpath. Speciation-solubility and mass-transfer modeling revealed two sets of chemical reactions for acid seepage and flushing, respectively. The current concentrations and distribution of ground water constituents can be interpreted as being controlled by stepwise pH-buffer reactions with calcite, amorphous aluminum hydroxide, and amorphous iron hydroxides. These buffer reactions divide the aquifer into zones of near-constant pH, separated by interface zones. For the flushing stage, it is predicted that reactions with surface-bound species will dominate the reaction paths, and more pore volumes are required to neutralize the plume than predicted by models that do not consider surface reactions. Direct mineralogical and surface analysis is needed to substantiate this assertion.