bluuebunny/crossref_metadata_2025 huggingface dataset:
Parallel Machines And Models — An Overview
Authors: Lakshmivarahan S. , Dhall Sudarshan K.
Published: November 2020

This chapter provides an overview of many issues related to the analysis of parallel algorithms in general. Starting with a discussion of the need for parallelism, a classification of parallel architectures, the need and the use of parallel models in algorithm development and various measures for quantifying the performance of parallel algorithms are presented. The definition, the role, and the properties of the key parallel complexity class called NC (Nick’s Class) are then described. This chapter concludes with a discussion of a basic result called Brent’s inequality and the derivation of a simple lower bound on the parallel time complexity. The conventional approach to engineering design critically depends on laboratory testing of scaled models — witness wind tunnel testing of models of aircraft and its parts. While such an approach has resulted in considerable success, it often involves destructive testing and is time consuming. It is said that it took nearly ten years and approximately three billion dollars to develop the now commercially successful Boeing 747 aircraft used in long-haul commercial flights. Computer simulation provides a convenient and economically attractive alternative. In simulation, the physical processes of interest are represented by a system of non-linear partial differential equations involving the three space dimensions and the time. These model equations are solved numerically using the finite difference or finite element methods. The behavior of the solution of these model equations provides insight on the effectiveness of the model in describing the physical phenomenon of interest, be it a model of an aircraft or a model of a weather phenomenon, etc. This approach, based on computer simulations has several inherent advantages. It is certainly non-destructive and easily allows for the analysis of the quality of the model for various combinations of initial and boundary conditions and the values of many key parameters of interest. The time required to complete a model run is a direct function of a number of factors. The number of grid points in space and time, the nature of the discretization scheme, such as, finite difference, finite elements, etc., the non-linearity and the coupling between the variables in the models.
Size vs. Depth Trade-Off In Parallel Prefix Circuits
Authors: Lakshmivarahan S. , Dhall Sudarshan K.
Published: November 2020

Ladner-Fischer [1980] was the first one to demonstrate size vs. depth trade-off in parallel prefix circuits. In this Chapter, a lower bound from Snir [1986] on (size + depth) for prefix circuits is first derived. Several designs of parallel prefix circuits with optimal (size + depth) trade-offs are described. In this section, we derive a lower bound from Snir [1986] on the sum of depth and size of a class of prefix circuits. Let x = { x1, x2, • • • , XN }, be a set of N variables. Let D be the domain over which elements of x take their values, and let FN = { f1, f 2, . . . , fN } be a set of functions satisfying the following conditions: (SR1) fi, depends only on the variables x1, x2 , • • • xi, and (SR2) For each variable xi, i = 1, 2, • • • , N, there exist values ai, in D, such that, the set of functions fj |xi = ai = fj(x1,x2, . . . , xi-1, xi = ai, xi+1, . . . , xj), j=1,2, . . . , N, contains a family of (N - 1) functions satisfying these conditions. The family FN satisfying these two conditions is called a self reducible family of functions. Clearly, fi (x1, x2, . . . , xi) = x1 o x2 o . . . o xi, 1 ≤ i ≤ N, satisfies these conditions. Following is an example of a self-reducible family of functions. An associative binary operation θ is said to be non-trivial if the following conditions are satisfied: (i) Let z = x θ y. Then z depends on both x and y, that is, θ is not a projection, nor a constant operation, and (ii) There exists a (right) unit element e of θ, such that, x = x θ e.
Cognitive Systems and the Scientific Explanation of Cognition
Authors: Giunti Marco
Published: November 2020

A cognitive system is any real system that has some cognitive property. Therefore, cognitive systems are a special type of K-systems (see chapter 3, section 3). Note that this definition includes both natural systems such as humans and other animals, and artificial devices such as robots, implementations of AI (artificial intelligence) programs, some implementations of neural networks, etc. Focusing on what all cognitive systems have in common, we can state a very general but nonetheless interesting thesis: All cognitive systems are dynamical systems. Section 2 explains what this thesis means and why it is (relatively) uncontroversial. It will become clear that this thesis is a basic methodological assumption that underlies practically all current research in cognitive science. The goal of section 3 is to contrast two styles of scientific explanation of cognition: computational and dynamical. Computational explanations are characterized by the use of concepts drawn from computation theory, while dynamical explanations employ the conceptual apparatus of dynamical systems theory. Further, I will suggest that all scientific explanations of cognition might end up sharing the same dynamical style, for dynamical systems theory may well turn out to be useful in the study of all types of models currently employed in cognitive science. In particular, a dynamical viewpoint might even benefit those scientific explanations of cognition which are based on symbolic models. Computational explanations of cognition, by contrast, can only be based on symbolic models or, more generally, on any other type of computational model. In particular, those scientific explanations of cognition which are based on an important class of connectionist models cannot be computational, for this class of models falls beyond the scope of computation theory. Arguing for this negative conclusion requires the formal explication of the concept of a computational system that I gave in chapter 1 (see definition 3). Finally, section 4 explores the possibility that scientific explanations of cognition might be based on Galilean models of cognitive systems (see chapter 3, section 5). Most cognitive scientists have not yet considered this possibility. The goals of this section are to contrast this proposal with the current modeling practice in cognitive science, to make clear its potential benefits, and to indicate possible ways to implement it.
Geological Methods for Archaeology
Authors: Herz Norman , Garrison Ervan G.
Published: November 2020

This book discusses the application of geological methods and theory to archaeology. Written as a survey text covering appropriate methods and techniques taken from geology, geophysics, geochemistry, and geochronology, it shows the student the practicality and importance of each technique's use in solving archaeological problems. Specific techniques are illustrated by practical results obtained from the authors' use on archaeological digs. With an international geographical scope, the book draws on sites from both hemispheres, including the Franchthi Cave in Greece, St. Catherines Island in the U.S., the Roman site of Drand in France, and Monte Verde, Chile. The authors also address applications in less traditional areas such as underwater, historical, industrial, and conservation archaeology.
Environmental Data for Specific Sites within the Dead Sea Region
Authors: Emery K. O. , Neev David
Published: November 2020

Discussion of Early Bronze cultural history at Bab edh-Dhr’a and Numeira sites east of the Lisan Peninsula and on the northeast flank of the Dead Sea south basin is guided mostly by Rast (1987) and Rast and Schaub (1974, 1978, 1980, and 1981). This epoch was divided by Rast and Schaub into two sections according to traditional archaeological chronology. The first section is the urban period of Bab edh-Dhr'a (4890 to 4340 B.P.) including Early Bronze I, II, and III. The second is the posturban period (4340 to 4190 B.P.), Early Bronze IV or the Intermediate Bronze age according to Kochavi (1967), Kenyon (1979), Gophna (1992), and R. Amiran and Kochavi (1985) as well as Middle Bronze I according to Albright (1962). Although no prominent cultural hiatus separates these two sections, the transition between them contains abundant indications of extensive destruction and fire events brought about by natural disasters such as earthquakes. Donahue (1980, 1981) considered that not just one but two severe earthquakes occurred, one about 4400 B.P. and the other 4350 B.P. Numeira was totally and finally abandoned after the second earthquake, whereas Bab edh-Dhr’a was reinhabited apparently as a result of conquest by seminomadic people of the same cultural background. This second earthquake probably was the one by which Sodom and Gomorrah were totally destroyed. Abrupt cultural changes also were recorded in the southeast Negev at Uvda Valley during transition from Early Bronze III to Middle Bronze I about 4300 B.P. These changes were from a gradually increasing population within a walled city having a life-style based on a combination of agriculture and animal husbandry into a more nomadic community with unfortified houses and primarily a grazing economy. According to Avner (1990, p. 133) “Subsequent to a brief climatic crisis at the end of the third millennium BC the climate improved, allowing the new culture to blossom in the desert.” This climatic crisis could have been extreme dryness. By the middle of the Intermediate Bronze age at about 4200 B.P., Bab edh-Dhr’a, the last Early Bronze site to survive was totally abandoned and the Dead Sea south basin remained basically unsettled for more than 1,500 years until Hellenistic time.
Particle Absorption and Scatter
Authors: Thomas Michael E.
Published: November 2020

Particles are composed of solids and/or liquids, thus the bulk optical properties of these media must be known before propagation modeling within a medium of suspended particles (called aerosols when in air) can begin. We return to our discussion of propagation in the atmosphere and oceans of the earth that began in Chapters 7 and 9, and we now include attenuation by small particles. Particles vary in size, shape, concentration, and composition. Size and concentration distributions are described in the following two sections. The composition of the most common particles is presented in the last section. Unfortunately, a representation of shape variation does not exist. As mentioned in Chapter 4 (Section 4.4.2 on Mie scattering), a collection of real aerosols will have a range of different radii. This is called a polydisperse medium. Various models are used to represent particle size distributions. One commonly used model for particle number density as a function of radius is the modified gamma distribution function, as given by . . . ρp(r) = Arα exp(−brγ), (10.1) . . . where A, b, α, and γ are empirically determined parameters. This function represents the number of particles per unit volume and unit radius as a function of radius r. The total particle number density is obtained by integrating ρp(r ) over all r.
William D. Phillips Memorial Lecture
Authors: Ackerman J.J.H.
Published: November 2020

It is a privilege to be able to share with you a few moments of reflection on William Dale Phillips, a good friend of mine and of many in this audience (Presented at a plenary session of the XVth International Conference on Magnetic Resonance in Biological Systems, August 14-19, 1994, Veldhoven, the Netherlands). Bill Phillips was a pioneer in the use of magnetic resonance for determination of protein structure. Although a major portion of his scientific career was spent in industry, primarily at EI du Pont de Nemours and Co. in Wilmington, Delaware. Bill also spent time in service to academics and the federal government. He most recently served as Associate Director for Industrial Technology in the Bush Administration’s Office of Science and Technology Policy. He was 68. The cause of his death was cancer of the prostate. I first met Bill Phillips in 1979 when George Radda, in whose laboratory I was working, suggested that I contact his good friend regarding a position at Washington University. Phillips had recently moved from DuPont, where he had been Assistant Director of Research and Development, to Washington University in St. Louis where he was Charles Allen Thomas Professor and Chairman of the Department of Chemistry. Bill had been given the task of rebuilding the department. I was immediately struck by his vision and sense of commitment. This was a person who got things done. I was hooked. In many ways Bill’s move to St. Louis was a return home to his beloved Midwest. He was born in Kansas, City, Missouri and grew up there graduating from high school at the age of 17 in 1943. During the war he served in the U.S. Navy V-12 program achieving the rank of Lt. (jg). After the war he returned to the Midwest and in 1948 he received a B.A. in chemistry from the University of Kansas. Following his undergraduate education, Bill left the Midwest again, this time for a long sojourn to the east coast. First stop was MIT where he studied physical chemistry (focusing on the vibrational spectroscopy of organic molecules). He received his Ph.D. in 1951. It was at MIT that Bill met Esther Parker, a Wellesley College student, better known to her friends as “Cherry”. Married in 1951, Cherry was a loving partner assisting Bill in his many adventures.
The Interaction of Antigens and Superantigens with the Human Class II Major Histocompatibility Complex Molecule HLA-DR1
Authors: Jardetzky T.
Published: November 2020

The initiation and maintenance of an immune response to pathogens requires the interactions of cells and proteins that together are able to distinguish appropriate non-self targets from the myriadof self-proteins (Janeway and Bottomly, 1994). This discrimination between self and non-self is in part accomplished by three groups of proteins of the immune system that have direct and specific interactions with antigens: antibodies, T cell receptors (TcR) and major histocompatibility complex (MHC) proteins. Antibodies and TcR molecules are clonally expressed by the B and T cells of the immune system, respectively, defining each progenitor cell with a unique specificity for antigen. In these cell types both antibodies and TcR proteins undergo similar recombination events to generate a variable antigen combining site and thus produce a nearly unlimited number of proteins of different specificities. TcR molecules are further selected to recognize antigenic peptides bound to MHC proteins, during a process known as thymic selection, restricting the repertoire of T cells to the recognition of antigens presented by cells that express MHC proteins at their surface. Thymic selection of TcR and the subsequent restricted recognition of peptide-MHC complexes by peripheral T cells provides a fundamental molecular basis for the discrimination of self from non-sell and the regulation of the immune response (Allen, 1994; Nossal, 1994; von Boehmer, 1994). For example, different classes of T cells are used to recognize and kill infected cells (cytotoxic T cells) arid to provide lymphokiries that induce the niajority of soluble antibody responses of B cells (helper T cells). In contrast to the vast combinatorial and clonal diversity of antibodies and TcRs, a small set of MHC molecules is used to recognize a potentially unlimited universe of foreign peptide antigens for antigen presentation to T cells (Germain, 1994). This poses the problem of how each MHC molecule is capable of recognizing enough peptides to insure an immune response to pathogens. In addition, the specificity of the TcR interaction with MHC-peptide complexes is clearly crucial to the problem of self :non-self discrimination, with implications for both protective immunity and auto-immune disease.
Design and Characterization of New Sequence Specific DNA Ligands
Authors: Wemmer D.
Published: November 2020

During the early 1980s there were two developments which lead to our studies of sequence specific DNA ligands. The first was the development of sequential assignment methods based on 2D NMR spectra which allowed complete assignment of resonances for proteins (Wüthrich, 1986). The assignments in turn allowed determination of many structural restraints through interpretation of NOESY crosspeaks and coupling constants from COSY type spectra. The second advance was the improvement of the chemistry for direct synthesis of DNA oligomers. With multimilligram samples of DNA oligomers available sequential assignment methods for DNA, paralleling those for proteins, were also worked out. Again with assignments came the possibility of determining DNA structures in solution. Howeverfor double stranded, Watson-Crick paired DNAs the structure can be reasonably approximated by the standard B-form model derived from fiber diffraction. The accurate determination of local conformational features has been somewhat difficult using NMR since tertiary contacts (as are so valuable in determining protein structures) do not occur. However with careful quantitative analysis some of the local details of structure can be determined. These NMR methods also offered the possibility of trying to understand the structural basis for binding of ligands to DNA oligomers. In order to make welldefined complexes we wanted to start with a compound that showed some sequence specificity in binding, and selected distamycin (shown below), a polypyrrole antibiotic which was known to have preference for binding to A-T rich DNA sequences. A close relative, netropsin, had been studied by Dinshaw Patel who showed that the binding is in the minor groove by identifying an NOE between a proton of the ligand and an adenosine H2 in the center of the minor groove (Patel, 1982). We began by making a complex with the self-complementary DNA oligomer: 5'-CGCGAATTCGCG-3', which had been studied extensively by X-- ray crystallography, and also by NMR. Distamycin did form a well-defined complex with this DNA, which was is slow exchange with free DNA during titrations (Klevit et al., 1986).
Time-Differencing Schemes
Authors: Krishnamurti T. N. , Bedi H. S. , Hardiker V. M.
Published: November 2020

Atmospheric models generally require the solutions of partial differential equations. In spectral models, the governing partial differential equations reduce to a set of coupled ordinary nonlinear differential equations where the dependent variables contain derivatives with respect to time as well. To march forward in time in numerical weather prediction, one needs to use a time-differencing scheme. Although much sophistication has emerged for the spatial derivatives (i.e., second- and fourth-order differencing), the time derivative has remained constructed mostly around the first- and second-order accurate schemes. Higher-order schemes in time require the specification of more than a single initial state, which has been considered to be rather cumbersome. Therefore, following the current state of the art, we focus on the first- and second-order accurate schemes. However, higher-order schemes, especially for long-term integrations such as climate modeling, deserve examination. We start with the differential equation dF/dt = G, where F = F(t) and G = G(t). If the exact solution of the above equation can be expressed by trigonometric functions, then our problem would be to choose an appropriate time step in order to obtain a solution which behaves properly; that is, it remains bounded with time. This is illustrated in Fig. 3.1. We next show that: (1) if an improper time step is chosen, then the approximate finite difference solution may become unbounded, and (2) if a proper time step is chosen, then the finite difference solution will behave quite similar to the exact solution. The stability or instability of a numerical scheme will be discussed for a single Fourier wave. This would also be valid for a somewhat more general case, since the total solution is a linear combination of sine and cosine functions, which are all bounded. We next define an amplification factor |λ|, the magnitude of which would determine whether a scheme is stable or not.
Polythermal, Fixed, and Sliding Paths
Authors: Bethke Craig M.
Published: November 2020

In this chapter we consider how to construct reaction models that are somewhat more sophisticated than those discussed in the previous chapter, including reaction paths over which temperature varies and those in which species activities and gas fugacities are buffered. The latter cases involve the transfer of mass between the equilibrium system and an external buffer. Mass transfer in these cases occurs at rates implicit in solving the governing equations, rather than at rates set explicitly by the modeler. In Chapter 14 we consider the use of kinetic rate laws, a final method for defining mass transfer in reaction models. Polythermal reactions paths are those in which temperature varies as a function of reaction progress, ξ. In the simplest case, the modeler prescribes the temperatures T0 and Tf at the beginning and end of the reaction path. The model then varies temperature linearly with reaction progress. This type of model is sometimes called a “sliding temperature” path. The calculation procedure for a sliding temperature path is straightforward. In taking a reaction step, the model evaluates the temperature to be attained at the step’s end.
Sediment Diagenesis
Authors: Bethke Craig M.
Published: November 2020

Diagenesis is the set of processes by which sediments evolve after they are deposited and begin to be buried. Diagenesis includes physical effects such as compaction and the deformation of grains in the sediment (or sedimentary rock), as well as chemical reactions such as the dissolution of grains and the precipitation of minerals to form cements in the sediment's pore space. The chemical aspects of diagenesis are of special interest here. Formerly, geologists considered chemical diagenesis to be a process by which the minerals and pore fluid in a sediment reacted with each other in response to changes in temperature, pressure, and stress. As early as the 1960s and especially since the 1970s, however, geologists have recognized that many diagenetic reactions occur in systems open to groundwater flow and mass transfer. The reactions proceed in response to a supply of reactants introduced into the sediments by flowing groundwater, which also serves to remove reaction products. Hay (1963, 1966), in studies of the origin of diagenetic zeolite, was perhaps the first to emphasize the effects of mass transport on sediment diagenesis. He showed that sediments open to groundwater flow followed reaction pathways different from those observed in sediments through which flow was restricted. Sibley and Blatt (1976) used cathodoluminescence microscopy to observe the Tuscarora orthoquartzite of the Appalachian basin. The almost nonporous Tuscarora had previously been taken as a classic example of pressure welding, but the microscopy demonstrated that the rock is not especially well compacted but, instead, tightly cemented. The rock consists of as much as 40% quartz (SiO2) cement that was apparently deposited by advecting groundwater. By the end of the decade, Hayes (1979) and Surdam and Boles (1979) argued forcefully that the extent to which diagenesis has altered sediments in sedimentary basins can be explained only by recognition of the role of groundwater flow in transporting dissolved mass. This view has become largely accepted among geoscientists, although it is clear that the scale of groundwater flow might range from the regional (e.g., Bethke and Marshak, 1990) to circulation cells perhaps as small as tens of meters (e.g., Bjorlykke and Egeberg, 1993; Aplin and Warren, 1994).
Comparative Results of 27Al NMR Spectrometric and Ferron Colorimetric Analyses of Hydroxyaluminum Hydrolysis Products in Aged, Mildly Acidic, Aqueous Systems
Authors: Vivit Davison V. , Thorn Kevin A.
Published: November 2020

The abundant presence of aluminum (Al) in the environment, its commercial importance, and the potential toxic effects of dissolved forms of Al on living organisms have brought about extensive studies of Al hydrolysis products that originate from natural processes and industrial activities. A recent review of past studies of hydroxyaluminum (hydroxy-Al) solutions illustrates the complexity of aluminum hydrolysis. Because of the need to identify and quantify individual Al ion species, initial investigations of concentrated solutions of hydroly/ed aluminum salts using 27A1 nuclear magnetic resonance (NMR) spectrometry began more than 20 years ago in the United Kingdom with continuous-wave instrumentation. Since then, groups in Switzerland, France, and the United States as well as in the UK, involved with geochemical and pharmacological investigations, have applied pulse NMR instruments to conduct research mostly with concentrated Al hydrolysates. In NMR spectrometry, shapes and positions of spectral peaks indicate aluminum nuclei in different chemical environments, and the peak areas are proportional to the number of nuclei in each given symmetry. Figures 8.1 (a) and (b) and 8.2(a) and (b) illustrate liquid-state 27A1 NMR spectra of aluminum hydrolysis products. The well-defined peak at 62.5ppm, downfield from the Oppm reference position for Al(H2O)3+6, has been attributed to the tetrahedrally coordinated aluminum ion within the highly symmetrical configuration of the [AlO4Al12(OH)24(H2O)12]7+ species or “Al13” polyion in aqueous solution. This geometrical arrangement, also termed the “Keggin” structure, was originally deduced from X-ray diffraction studies of aluminum hydroxysulfate and hydroxyselenate salts precipitated from heated concentrated aluminum solutions after being partly neutralized with base. The Al13 structural unit that was postulated has 12 Al ions octahedrally coordinated with OH ions enclosing the central tetrahedral Al ion which is bonded to four of the octahedral ions through bridging by O2− ions. For a given sample specimen, broad NMR spectral peaks indicate the existence of (1) chemical-exchange processes and (2) species having less symmetry and larger electric field gradients than those which give rise to narrower peaks. Mildly acidic solutions of aluminum hydrolysis products exhibit a broad peak downfield from 0ppm centered at ~1 to ~2ppm.
X-Ray Charge Densities and Chemical Bonding
Authors: Coppens Philip
Published: November 2020

This book deals with the electron density distribution in molecules and solids as obtained experimentally by X-ray diffraction. It is a comprehensive treatment of the methods involved, and the interpretation of the experimental results in terms of chemical bonding and intermolecular interactions. Inorganic and organic solids, as well as metals, are covered in the chapters dealing with specific systems. As a whole, this monograph is especially appealing because of its broad interface with numerous disciplines. Accurate X-ray diffraction intensities contain fundamental information on the charge distribution in crystals, which can be compared directly with theoretical results, and used to derive other physical properties, such as electrostatic moments, the electrostatic potential and lattice energies, which are accessible by spectroscopic and thermodynamic measurements. Consequently, the work will be of great interest to a broad range of crystallographers and physical scientists.
Chemical Bonding and the X-ray Scattering Formalism
Authors: Coppens Philip
Published: November 2020

The assumption that the atomic electron density is well described by the spherically averaged density of the isolated atom has been the basis of X-ray structure analysis since its inception. The independent-atom model (IAM) is indeed a very good approximation for the heavier atoms, for which the valence shell is a minor part of the total density, but is much less successful for the lighter atoms. The lightest atom, hydrogen, has no inner shells of electrons, so that the effect of bonding is relatively pronounced. Because of the overlap density in covalent X—H bonds (X = C, N, O), the mean of the hydrogen electron distribution is significantly displaced inwards into the bond. When a spherical IAM hydrogen scattering factor is used in a least-squares adjustment of the atomic “position,” the result will be biased because the centroid of the density associated with the H atom is shifted in the direction of the bond. The result is an apparent shortening of X—H bonds which is far beyond the precision of X-ray structure determination (Hanson et al. 1973). For sucrose, for example, the differences between X-ray and neutron bond lengths are 0.13 (1) Å averaged over 14 C—H bonds, and 0.18 (3) A averaged over eight O—H bonds (Hanson et al. 1973). The observed discrepancy between X-ray results and spectroscopic values was first explained in terms of the electron distribution in the 1950s by Cochran (1956) and Tomii (1958). That the bond density is also of significance for heavier atoms is evident from the occurrence of the spherical-atom forbidden (222) reflection of diamond and silicon, even at low temperatures where anharmonic thermal effects (see chapter 2) are negligible. The historical importance of the nonzero intensity of the diamond (222) reflection is illustrated by the following comment made by W. H. Bragg, in 1921: . . . Another point of interest is the existence of a small (222) reflection (in diamond). This has been looked for previously but without success. . . .
The Electron Density and the Lattice Energy of Crystals
Authors: Coppens Philip
Published: November 2020

The total energy of a quantum-mechanical system can be written as the sum of its kinetic energy T, Coulombic energy ECoui and exchange and electron correlation contributions Ex and Ecorr, respectively: . . . E=T+Ecoui+Ex+Ecorr (9.1) . . . The only term in this expression that can be derived directly from the charge distribution is the Coulombic energy. It consists of nucleus–nucleus repulsion, nucleus–electron attraction, and electron–electron repulsion terms.
Contending with Modernity
Authors: Gleason Philip
Published: November 2020

How did Catholic colleges and universities deal with the modernization of education and the rise of research universities? In this book, Philip Gleason offers the first comprehensive study of Catholic higher education in the twentieth century, tracing the evolution of responses to an increasingly secular educational system. At the beginning of the century, Catholics accepted modernization in the organizational sphere while resisting it ideologically. Convinced of the truth of their religious and intellectual position, the restructured Catholic colleges grew rapidly after World War I, committed to educating for a "Catholic Renaissance." This spirit of militance carried over into the post-World War II era, but new currents were also stirring as Catholics began to look more favorably on modernity in its American form. Meanwhile, their colleges and universities were being transformed by continuing growth and professionalization. By the 1960's, changes in church teaching and cultural upheaval in American society reinforced the internal transformation already under way, creating an "identity crisis" which left Catholic educators uncertain of their purpose. Emphasizing the importance to American culture of the growth of education at all levels, Gleason connects the Catholic story with major national trends and historical events. By situating developments in higher education within the context of American Catholic thought, Contending with Modernity provides the fullest account available of the intellectual development of American Catholicism in the twentieth century.
DNA
Authors: Rice Peter M. , EHiston Keith
Published: November 2020

Software packages are available for all common laboratory computer systems. The packages for personal computers (PC or Macintosh) are able assemble and correct the sequence, those for the larger systems (VAX or Unix) are generally able to analyze the sequence in greater detail. Most laboratories will be able to use sequence assembly programs in their favorite sequence analysis software package. In general, the stages of sequence assembly are gel entry, overlap detection, editing, and reporting. The available programs differ in the ways they handle each of these tasks. No single package is ideal, though all should be adequate for a smaller project such as a single cDNA. Particular attention should be given to the quality and features of the editor, as this is where most time will be spent, and to the possibilities of extending the software to cope with problems that may arise. Good status reports and a choice of methods for overlap detection can save considerable time in resolving ambiguities and correcting errors later. Figure 1 lists some of the commonly used sequence assembly programs. The prices vary widely depending on the features of the package and the options for academic or commercial licenses. Originally, each package used its own “special” codes to represent ambiguous bases and gaps in sequences. Mostpackages now use the standard IUB-IUPAC codes (Figure 2) for the nucleotides, though the program documentation should be checked before starting the project. The task of sequence reading depends on the sequencing protocol used. In many laboratories the sequence is generated on an autoradiograph (Figure 3) from which the sequence is read. Although automated gel readers are on the market, most sequence data is read manually with the aid of a digitizer. Most sequence assembly programs accept DNA sequence read by a sonic digitizer. An example of a device which is supported by most of the available programs is the GrafBar GP-7 [Science Accessories Corporation, Southport, CT, US A and P.M.S. (Instruments) Ltd., Waldeck House, Reform Road, Maidenhead, Berks, SL6 8BX, UK]. Sonic digitizers have a stylus to point to locations on an autoradiograph, which is illuminated from below by a light box.
Visual Information and Valid Reasoning
Authors: Barwise Jon , Etchemendy John
Published: November 2020

Psychologists have long been interested in the relationship between visualization and the mechanisms of human reasoning. Mathematicians have been aware of the value of diagrams and other visual tools both for teaching and as heuristics for mathematical discovery. As the chapters in this volume show, such tools are gaining even greater value, thanks in large part to the graphical potential of modern computers. But despite the obvious importance of visual images in human cognitive activities, visual representation remains a second-class citizen in both the theory and practice of mathematics. In particular, we are all taught to look askance at proofs that make crucial use of diagrams, graphs, or other nonlinguistic forms of representation, and we pass on this disdain to our students. In this chapter, we claim that visual forms of representation can be important, not just as heuristic and pedagogic tools, but as legitimate elements of mathematical proofs. As logicians, we recognize that this is a heretical claim, running counter to centuries of logical and mathematical tradition. This tradition finds its roots in the use of diagrams in geometry. The modern attitude is that diagrams are at best a heuristic in aid of finding a real, formal proof of a theorem of geometry, and at worst a breeding ground for fallacious inferences. For example, in a recent article, the logician Neil Tennant endorses this standard view: . . . [The diagram] is only an heuristic to prompt certain trains of inference; . . . it is dispensable as a proof-theoretic device; indeed, . . . it has no proper place in the proof as such. For the proof is a syntactic object consisting only of sentences arranged in a finite and inspectable array (Tennant [1984]). . . . It is this dogma that we want to challenge. We are by no means the first to question, directly or indirectly, the logocentricity of mathematics arid logic. The mathematicians Euler and Venn are well known for their development of diagrammatic tools for solving mathematical problems, and the logician C. S. Peirce developed an extensive diagrammatic calculus, which he intended as a general reasoning tool.
Business
Authors: Pool Robert
Published: November 2020

In January 1975, the magazine Popular Electronics trumpeted the beginnings of a revolution. “Project Breakthrough,” the cover said: “World’s First Minicomputer Kit to Rival Commercial Models.” Inside, a six-page article described the Altair, an unassembled computer that could be ordered from MITS, a company in Albuquerque originally founded to sell radio transmitters for controlling model airplanes. To the uninitiated, it didn’t look like much of a revolution. For $397 plus shipping, a hobbyist or computer buff could get a power supply, a metal case with lights and switches on the front panel, and a set of integrated circuit chips and other components that had to be soldered into place. When everything was assembled, a user gave the computer instructions by flipping the panel’s seventeen switches one at a time in a carefully calculated order; loading a relatively simple program might involve thousands of flips. MITS had promised that the Altair could be hooked up to a Teletype machine for its input, but the circuit boards needed for the hookup wouldn’t be available for a number of months. To read the computer’s output, a user had to interpret the on/off pattern of flashing lights; it would be more than a year before MITS would offer an interface board to transform the output into text or figures on a television screen. And the computer had no software. A user had to write the programs himself in arcane computer code or else borrow the efforts of other enthusiasts. One observer of the early computer industry summed up the experience like this: “You buy the Altair, you have to build it, then you have to build other things to plug into it to make it work. You are a weird-type person. Because only weird-type people sit in kitchens and basements and places all hours of the night, soldering things to boards to make machines go flickety-flock.” But despite its shortcomings, several thousand weird-type people bought the Altair within a few months of its appearance. What inspired and intrigued them was the semiconductor chip at the heart of the computer.
Foundation Concepts
Authors: Kukulska-Hulme Agnes
Published: November 2020

• Why is communication a risky undertaking? • When do computer users find themselves at a loss for words? • Why does it matter that words go together in pairs? • Are there words that are never spoken? • Can someone know a great deal about a word without understanding it? . . . This chapter begins to shed some light on fundamental issues connected to language. It explores the above questions and introduces some conceptual distinctions that will help in understanding the more specific, applied notions considered in parts II and III. The core concepts are communication, function, and meaning, and these are explained along with other important related terms. Grammar is discussed in a communicative perspective, and language is set in the context of other modes of communication and in relation to reality (a philosophical issue, tackled here strictly from an applied language angle). Most of us know that the language we speak, English, for example, is not really one language but many—due to regional variations, for instance. Most people are also aware of qualitative differences: “good” and “bad” English. This value judgment is the basis of what can be described as a prescriptive attitude to language. “Correct” spelling, punctuation, and grammar immediately spring to mind. The prescriptive view has it that there are certain standards and conventions to be maintained, in order to protect or preserve the language or for the sake of good communication. Accuracy, consistency, and avoidance of jargon are often quoted as qualities of English that enhance communication. Advice on how to achieve these qualities can be found in “guides to style and usage,” such as Gowers (1954). Cameron (1996) is a recent academic work that discusses the issue of “correct” language in a balanced way. Although advocating “correct” usage, some of the style guides stress the fact that they are against pedantry or language dictatorship. This more liberal approach to language correctness is a relatively recent development. Simon Jenkins notes that: “Guidance that might once have been mandatory is often now permissive”.
Language Change
Authors: Kukulska-Hulme Agnes
Published: November 2020

• Are computer applications changing our language? • Why do some people reject technology? • Are adults willing to change their language? • Do other cultures want to borrow English computing terms? • Is our knowledge of word meanings out of date? . . . In this chapter on language change, we address these questions first by examining the reasons for change and looking at the various types of change that can occur. We then focus on developments in the language of adults (life-long language learning) and on how language is organized in the minds of speakers. We consider people’s expectations with regard to meanings as well as the process of acquiring new words and meanings. The final part of the chapter deals with the issue of borrowing words from other languages. No one really knows why languages change over time, though a number of possible explanations have been put forward concerning specific instances of change. Historical events can sometimes provide explanations, when new contact or loss of contact between groups of people is eventually reflected in the word stock or sounds of a language. It is interesting to speculate whether electronic contact (e.g., through the Internet) might have the same degree of power to change languages over time. Certainly, in that environment, as in the “real world,” social forces can be observed: Borrowing words from another language and integrating them into one’s own can be part of a process of wanting to imitate another culture—especially one that is seen to be more fashionable or more technologically advanced. If new objects, ideas, and processes have to be named, new words will appear; similarly, old ones will fall out of use. Technological advancements contribute to these needs. They also create new human communication environments, which require new forms of text or speech, which in turn have an effect on the language to be used.
Language Correspondences
Authors: Kukulska-Hulme Agnes
Published: November 2020

• Is a crossword puzzle clue a definition of a word? • Can you enter to exit? • Are unrecoverable errors recoverable? • How can a word like “caution” mean “guarantee”? • What is it that happens unless you do something else? . . . This chapter is about the ways in which elements of language are at times able to correspond to each other in usage and in meaning. It explains equivalence, the baseline for distinctions between words, and clarifies widespread misconceptions about synonyms. It shows that words have values that are sometimes obvious and sometimes concealed. These concepts are relevant to all word choices in language, and they must be considered with due attention with translation of a user interface or documentation into another language. Ambiguity and culture are the two big issues that will inevitably come to the fore at such a time. It will also become clear that there are gaps to be filled in languages, and that interference and confusion are bound to get in the way. Multiple language environments create their own special demands with respect to all of these concepts. In a typical crossword puzzle, we are asked to think of words that correspond to descriptions or suggestions of their meaning. Because a crossword is a kind of game, the clues may well be phrased so as to make the word discovery difficult. By contrast, in dictionaries, descriptions of meaning are meant to correspond much more directly to designated words. A direct link is made between a particular language element—a word or phrase—and the language used to express its meaning, which stands in or substitutes for that element in a variety of ways. Definition is one way, within one language; translation is another way, between languages. Equivalence, in the sense of a perfect match on the level of meaning, may be achieved through definition, which draws on a rich range of language resources, but equivalence is much more problematic in translation. In translation into a target language, a word with exactly the same meaning may not exist.
Explanation and Assistance
Authors: Kukulska-Hulme Agnes
Published: November 2020

It is easy to say that an explanation should be simple and that it should be written in familiar language. Advice of this sort is offered in many a technical writing handbook, often with limited elaboration. The concepts of familiarity and simplicity are not as straightforward as they appear to be, however. Users’ familiarity with particular terms can never really be predetermined because of the different ways we can “know” a word (as described in chapter 2). And what exactly is “simple” language? Hartley (1985), in his book on designing instructional text, makes several references to a writer’s conscious selection of words for a target text. Word length is mentioned (short, familiar words are easier to understand, although some long words, because of their frequent use, are quite familiar, e.g., “communication”), word type (concrete words and phrases are clearer than abstract ones), and ambiguity resulting from excessive use of abbreviations and acronyms. He also writes about the option of using readability formulas to check the suitability of a text for a given reader age group. Emden (1990) devotes a section to vocabulary choice in her handbook on writing for engineers and offers this advice: “Use words which the reader will understand”. She rightly points out the insidious danger in the use of technical language: “The reader may assume that he understands and the writer may assume that he is understood. Both may be understanding different meanings”. Sides (1984), cautioning about the use of jargon in papers and reports on computer technology, says this: “The issue of jargon is audience-dependent. Always use what the audience will understand”. This is sound advice, yet on reflection, it is so cursory that it is doubtful whether it can genuinely be fol lowed. The writer can strive to get to know the audience, and even think about providing definitions of terms, but there is still the matter of knowing how to select words or adapt one’s “jargon.” Use “fewer and simpler words,” advises Sides, referring to S. T. Coleridge as an authority on the matter.