Showing papers by "University of Sussex published in 1991"

The creative mind: myths and mechanisms

Abstract: How is it possible to think new thoughts? What is creativity and can science explain it? And just how did Coleridge dream up the creatures of The Ancient Mariner? When The Creative Mind: Myths and Mechanisms was first published, Margaret A. Boden's bold and provocative exploration of creativity broke new ground. Boden uses examples such as jazz improvisation, chess, story writing, physics, and the music of Mozart together with computing models from the field of artificial intelligence to uncover the nature of human creativity in the arts, science and everyday life. The second edition of The Creative Mind has been updated to include recent developments in artificial intelligence, with a new preface, introduction and conclusion by the author. It is an essential work for anyone interested in the creativity of the human mind.

Large Firms in the Production of the World's Technology: An Important Case of “Non-Globalisation”

Abstract: US patenting by 686 of the world's largest manufacturing firms shows that their share of the world's production of technology is less than their share of R&D activities, and varies greatly amongst sectors. In most cases, the technological activities of these large firms are concentrated in their home country, the characteristics of which influence the volume and trends in their technological activities much more strongly then the international component of these activities. At the same time, these large firms are major elements in the volume and the pattern of sectoral specializations in their home countries' technological activities.

A lognormal model for the cosmological mass distribution.

Abstract: The use of a lognormal (LN) random field is discussed as a model for the distribution of matter in the Universe. A number of difficulties with the statistical treatment of density perturbations are revealed by an analysis of this model. In particular, the LN model is not completely specified by its moments. The reason for which this could be true for the actual matter field is explained. It is also shown that the usual method of representing the three- and four-point correlation functions of galaxies, in terms of the parameters Q and R, is not useful for discriminating between Gaussian and non-Gaussian fluctuations, and better parameterizations are proposed in terms of the skewness and kurtosis of the three- and four-point distributions, respectively.

External Linkages and Innovation in Small and Medium-Sized Enterprises

Abstract: While small and medium-sized enterprises (SMEs) can enjoy a number of behavioural advantages over their larger counterparts in the innovation process (e.g. rapid response to external threats and opportunities; efficient internal communication; interactive management style), they can also suffer from a number of mainly material disadvantages (e.g. inability to spread risk over a portfolio of new products; difficulties in market start-up abroad; problems in funding longer-term R&D). One area in which SMEs can suffer a marked disadvantage is that of establishing the appropriate network of contacts with external sources of scientific and technological expertise and advice. This paper addresses the issue of SMEs’ external linkages and presents data from a number of studies showing the importance of in-house technical skills to linkage activity; the importance of complementary between in-house and external know-how accumulation; and the importance of technology strategy in guiding the accumulation process. SME-oriented public technology policies should be adapted to the specific needs of SMEs in that they should focus on facilitating vertical (supplier-manufacturercustomer) linkages and offer support throughout the innovation chain from pre- competitive research through to product development. Numerous studies testify to the importance of firms extensively ‘networking’ in order to improve innovation potential (for example, Mowery, 1988; Contractor and Lorange, 1988; CEST, 1990). The majority of these studies focus on formal technology agreements, such as RD tend to feature large firm collaboration rather than that undertaken by small and medium-sized enterprises (SMEs); and while they often refer to the management problems involved in collaboration, few examine their management in any depth. This paper will describe the extensive collaborations of innovative SMEs, and will emphasise how the employment of key personnel affects the range and scope of linkages. It will highlight the broad diversity of linkages used by SMEs for technological development. And, by means of a case study of a highly technologically advanced SME, it will examine some of the most important management problems facing the collaborative process.

Localized sex in bacteria.

Abstract: Electrophoretic studies suggest that bacterial populations consist of a number of independent clones and that genetic recombination is rare in nature. But DNA sequencing reveals that individual bacterial genes have a mosaic structure that could have arisen only by recombination. How can these observations be reconciled and what is their relevance to prokaryotic evolution?

Large-scale structure in the Universe

Abstract: A variety of observations constrain models of the origin of large-scale cosmic structures. Enough observational data have accumulated to constrain (and perhaps determine) the power spectrum of primordial density fluctuations over a very large range of scales, independently of the particular cosmogonical theory assumed. Observations in the near future should be able to weed out many such theories.

Key Characteristics of the Large Innovating Firm

Abstract: SUMMARY Large innovating firms are a major source of the world's technology, and in the 20th century have shown great resilience in absorbing successive waves of radical innovations. The key characteristics of these firms derive from the properties of their innovative activities. First, given the specific, differentiated and cumulative nature of technological development, the range of possible choices about both product and processed technologies open to the firm depends on its accumulated competence. Second, given functional and professional specialization, the implementation of technological choices requires organization and orchestration across disciplinary, functional and divisional boundaries. Third, given cumulative development and uncertainty, the improvement of these competences requires continuous and collective learning. Fourth, in the light of these characteristics, systems for allocating resources must take into account the benefits of learning by doing, as well as the benefits of outcomes. As a consequence, the technical function in large firms involves not just the implementation of innovations, but also the definition of appropriate divisional objectives and boundaries, the exploration of radical technologies, and the formation of technological expectations about the future.

Horizontal transfer of multiple penicillin-binding protein genes, and capsular biosynthetic genes, in natural populations of Streptococcus pneumoniae.

Abstract: Summary Multiply antibiotic-resistant serotype 23F isolates of Streptococcus pneumoniae are prevalent in Spain and have also been recovered recently in the United Kingdom and the United States. Analysis of populations of these isolates by multilocus enzyme electrophoresis, and restriction endonuclease cleavage electrophoretic profiling of penicillin-binding protein (PBP) genes, has demonstrated that these isolates are a single clone (Munoz et al., 1991). Here we report studies of non-serotype 23F penicillin-resistant pneumococci isolated in Spain and the United Kingdom. One of the isolates expressed serotype 19 capsule but was otherwise indistinguishable from the serotype 23F clone on the basis of multilocus enzyme electrophoresis, antibiotic resistance profiling, and restriction endonuclease patterns of genes encoding PBP1A, PBP2B and PBP2X, a result which suggests that horizontal transfer of capsular biosynthesis genes had occurred. These same techniques revealed that six other resistant isolates, all expressing serotype 9 polysaccharide capsule, represent a clone. Interestingly, the chromosomal lineage of this clone is not closely related to the 23F clone; however, the serotype 9 and 23F clones harbour apparently identical PBP1 A, -2B and -2X genes. To explain these data, we favour the interpretation that horizontal gene transfer in natural populations has distributed genes encoding altered forms of PBP1A, -2B and -2X to distinct evolutionary lineages of S. pneumoniae.

Interspecies recombinational events during the evolution of altered PBP 2x genes in penicillin-resistant clinical isolates of Streptococcus pneumoniae.

Abstract: Penicillin resistance in pneumococci is due to the appearance of high molecular-weight penicillin-binding proteins (PBPs) that have reduced affinity for the antibiotic. We have compared the PBX 2x genes (pbpX) of one penicillin-susceptible and five penicillin-resistant clinical isolates of Streptococcus pneumoniae isolated from various parts of the world. All of the resistant isolates contained a low-affinity form of PBP 2x. The 2 kb region of the two penicillin-susceptible isolates differed at only eight nucleotide sites (0.4%) and resulted in one single amino acid difference in PBP 2x. In contrast, the sequences of the PBP 2x genes from the resistant isolates differed overall from those of the susceptible isolates at between 7 and 18% of nucleotide sites and resulted in between 27 and 86 amino acid substitutions in PBP 2x. The altered PBP 2x genes consisted of regions that were similar to those of susceptible strains (less than 3% diverged), alternating with regions that were very different (18-23% diverged). The presence of highly diverged regions within the PBP 2x genes of the resistant isolates contrasts with the uniformity of the sequences of the amylomaltase genes from the same isolates, and with the uniformity of the PBP 2x genes in the two susceptible isolates. It suggests that the altered PBP 2x genes have arisen by localized interspecies recombinational events involving the PBP 2x genes of closely related streptococci, as has been suggested to occur for altered PBP 2b genes (Dowson et al., 1989b). The PBP 2x genes from the resistant isolates could transform the susceptible strain R6 to increased levels of resistance to beta-lactam antibiotics, indicating that the altered forms of PBP 2x in the resistant isolates contribute to their resistance to penicillin.

The Cahn–Hilliard gradient theory for phase separation with non-smooth free energy Part II: Numerical analysis

Abstract: A mathematical analysis is carried out for the Cahn–Hilliard equation where the free energy takes the form of a double well potential function with infinite walls. Existence and uniqueness are proved for a weak formulation of the problem which possesses a Lyapunov functional. Regularity results are presented for the weak formulation, and consideration is given to the asymptotic behaviour as the time becomes infinite. An investigation of the associated stationary problem is undertaken proving the existence of a nontrivial stationary solution and further regularity results for any stationary solution. Stationary solutions are constructed in one and two dimensions; a formula for the number of stationary solutions in one dimension is derived. It is then natural to study the asymptotic behaviour as the phenomenological parameter λ→0, the main result being that the interface between the two phases has minimal area.

Theories of sexual selection.

Abstract: Recent research on sexual selection in animals has begun to indicate that ‘handicaps' and ‘honest signalling' may play more important roles than hitherto thought. This review reappraises theories of sexual selection in the light of these new developments.

Ion accumulation in the cell walls of rice plants growing under saline conditions: evidence for the Oertli hypothesis

Abstract: When plants of rice (Oryza sativa L.) are subjected to mildly saline (50 mol m-3 NaCl) conditions, the leaves show symptoms of water deficit, even though ion accumulation has been more than sufficient to adjust to the decrease in external water potential. After a few days of exposure to salt, there is a negative correlation, in a population of leaves, between the leaf water concentration (g water per g dry weight) and their sodium concentration (mmol Na per g dry weight). Ion concentrations in the cell walls and the cytoplasm of cells of plants grown in low salinity were measured by X-ray microanalysis. The NaCl concentration in solution in the apoplast was calculated to be around 600 mol m-3 in leaves of plants whose roots were exposed to only 50 mol m-3 NaCl. This constitutes strong evidence that an important factor in salt damage in rice is dehydration due to the extracellular accumulation of salt as suggested in the Oertli hypothesis. The implication, that changes in tissue ion concentration and solute potentials equivalent to the external medium is not evidence of plant osmotic adjustment to salinity, is discussed.

Substantive and procedural uncertainty

Abstract: Different sources of uncertainty are analysed and a representation of decision-making in principle consistent with behavioural evidence is proposed. The endogenous emergence of “innovations”, in the forms of unexpected events and novel behaviours is also examined.

Large infrared nonlinear optical response of C60.

Abstract: ${\mathrm{C}}_{60}$Buckminsterfullerene exhibits a large ultrafast third-order nonlinear optical response. Degenerate four-wave-mixing measurements in ${\mathrm{C}}_{60}$-benzene solutions were performed using 50-psec pulses at 1.064 \ensuremath{\mu}m. The magnitude of the nonlinear susceptibility per ${\mathrm{C}}_{60}$ molecule is \ensuremath{\Vert}\ensuremath{\gamma}\ensuremath{\Vert}=1.5\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}42}$ ${\mathrm{m}}^{5}$ ${\mathrm{V}}^{\mathrm{\ensuremath{-}}2}$ and of the same size as that observed in polydiacetylene. In contrast to conjugated polymers, however, a dominant positive real part of the nonlinearity is found, 3 times larger than the imaginary component. The nonlinear response can be described within the model of a free electron in a spherical box, confirming the complete delocalization of electrons on the ${\mathrm{C}}_{60}$ molecule.

Pleased and surprised: Children's cognitive theory of emotion

Abstract: This study looks at two emotions that are determined by whether a person's mental state matches or mismatches the state of the world. Results show that children from 3 years understand that being ‘pleased’ is a function of the match or mismatch between desire and reality. That is between what a person wants and what a person gets. A structurally similar problem is presented by the emotion ‘surprise’. ‘Surprise’ is a function of the match or mismatch between belief and reality. That is between what a person believes or expects to be the case and what actually is the case. It is shown that ‘surprise’ is not understood until children are 5 years old at the earliest. This developmental discrepancy can partly be explained by the fact that ‘surprise’ requires an understanding of belief as a misrepresentation. This is not typically understood before children reach 4 years of age. However, children younger than 4 years can understand ‘pleased’ as the result of reaching or not reaching a desired situation. Results also show that it is not until 5 years of age that children understand ‘happiness’ when ‘happiness’ is made dependent on belief about reality and not on reality itself. The fact that children understand ‘surprise’ and belief-based ‘happiness’ later than 4 years indicates a general lag between understanding belief and its role in determining emotion.

Technology Learning, Technology Strategy and Competitive Pressures

Abstract: SUMMARY This paper develops some hypotheses concerning technological learning in firms. The hypotheses are examined using a detailed study of Europe's leading dedicated biotechnology firm, Celltech Ltd. It relates how the competitive pressures facing the company, and similar US companies, have changed over the past decade, and how Celltech's technology strategy has placed considerable emphasis on technological learning in order to maintain its competitive position compared with large, multinational pharmaceutical companies. Some of the features of technological learning are examined, including: its purposive character; its differential and complex nature; its internal and external components; the complementary nature of the company's technology and human resource development strategy; and the importance of organizational considerations.

North‐South trade and female labour in manufacturing: An asymmetry

Abstract: A simple method of measuring the impact of North‐South trade on the female intensity of manufacturing is applied to data for developed and developing countries. The results confirm that growth of exports has increased the relative demand for female labour in the South. However, there does not appear to have been a general counterpart reduction in the relative demand for female labour in Northern manufacturing, even among blue‐collar workers. There are several possible reasons for the apparent conflict between these findings and other evidence that in Northern manufacturing females have been disproportionately displaced by trade with the South.

A comparison of variational and non-variational internally contracted multiconfiguration-reference configuration interaction calculations

Abstract: The internally contracted multiconfiguration-reference configuration interaction (CMRCI) method and several non-variational variants of this method (averaged coupled pair approximation (ACPF), quasidegenerate variational perturbation theory (QD-VPT), linearized coupled pair many electron theory (LCPMET)) have been employed to compute potential energy functions and other properties for a number of diatomic molecules (F2, O2, N2, CN, CO) using large basis sets and full valence CASSCF reference wavefunctions. In most cases the variational CMRCI wavefunctions yield more accurate spectroscopic constants than any of the employed non-variational methods. Several basis sets are compared for the N2 molecule. It is found that atomic natural orbital (ANO) contractions led to significant errors in the computedr e , ω e , andD e values.