Showing papers by "University of Glasgow published in 1987"

Towards a Cognitive Theory of Emotions

Abstract: A theory is proposed that emotions are cognitively based states which co-ordinate quasi-autonomous processes in the nervous system. Emotions provide a biological solution to certain problems of transition between plans, in systems with multiple goals. Their function is to accomplish and maintain these transitions, and to communicate them to ourselves and others. Transitions occur at significant junctures of plans when the evaluation of success in a plan changes. Complex emotions are derived from a small number of basic emotions and arise at junctures of social plans.

Recombinant dna sequences, vectors containing them and method for the use thereof

Abstract: Recombinant DNA sequences which encode the complete amino acid sequence of a glutamine synthetase, vectors containing such sequences, and methods for their use, in particular as dominant selectable markers, for use in co-amplification of non-selected genes and in transforming host cell lines to glutamine independence.

Topographical control of cell behaviour I. Simple step cues

Abstract: The photolithographic techniques of the microelectronics industry have allowed us to fabricate patterned plastic substrata to investigate contact guidance of animal tissue cells. The reactions of cells to single steps on a substratum were examined using time-lapse videorecording and scanning electron microscopy. BHK cells and chick embryonic neural cell processes exhibited gradual inhibition of crossing steps with a concomitant increase in alignment at steps dependent on increasing step height. Comparison of these cells' reactions, with those of chick heart fibroblasts and rabbit neutrophils, at a 5 micron step revealed that the influence of topography is also dependent on cell type, the neutrophils being relatively unaffected. The presence of an adhesive difference at a series of steps altered BHK cells' reactions such that the frequency of crossing was dependent on the direction of approach to a step. Although our data are consistent with Dunn & Heath's proposal (1976) that the inflexibility of the cytoskeleton of a moving cell's protrusion is the cellular property determining such reactions to topography, we have found that, on encountering a topographical feature, the response of a cell may be predictable on a probabilistic basis, i.e. the topographical feature reduces the probability of a cell making a successful protrusion and contact in a given direction, that even the largest features tested did not act as absolute barriers to cell locomotion since a small proportion of a population of cells were able to overcome them, and that other guidance cues could significantly alter a cell's response. Even in situations where it is not the primary cue in directing cell locomotion, topographical control may be an important factor during morphogenesis since it must, at the very least, influence the efficiency of other cues.

Types and persistence in database programming languages

Abstract: Traditionally, the interface between a programming language and a database has either been through a set of relatively low-level subroutine calls, or it has required some form of embedding of one language in another. Recently, the necessity of integrating database and programming language techniques has received some long-overdue recognition. In response, a number of attempts have been made to construct programming languages with completely integrated database management systems. These languages, which we term database programming languages, are the subject of this review.The design of these languages is still in its infancy, and the purpose of writing this review is to identify the areas in which further research is required. In particular, we focus on the problems of providing a uniform type system and mechanisms for data to persist. Of particular importance in solving these problems are issues of polymorphism, type inheritance, object identity, and the choice of structures to represent sets of similar values. Our conclusion is that there are areas of programming language research—modules, polymorphism, persistence, and inheritance—that must be developed and applied to achieve the goal of a useful and consistent database programming language. Other research areas of equal importance, such as implementation, transaction handling, and concurrency, are not examined here in any detail.

Insect Midgut Function

Abstract: Publisher Summary This chapter presents recent progress in the study of the midgut, particularly with reference to ion and water transport. However, the midgut does not function in isolation, and so the attempt is to fit the role of the midgut into the context of the operation of the gut as a whole. The chapter considers the cockroach as an example of a classic generalist and looks at scavenging dipteran larvae, mainly aquatic. Midgut function is described in various types of insects such as solid/plant feeders (phytophagous insects), solid/animal feeders (carnivores), liquid/animal feeders (bloodsuckers), and liquid/plant feeders (sap and nectar feeders). The chapter also discusses the process of digestion of cellulose in insects. There are four categories of evidence that an insect can digest cellulose. It could survive on a diet of pure synthetic cellulose; it could be shown to incorporate and metabolize label from radioactive cellulose in the food; it could be shown to break down synthetic crystalline cellulose; or it could be shown that there is less cellulose in the excreta than was consumed in the food.

Calcitonin gene-related peptide and cerebral blood vessels: distribution and vasomotor effects.

Abstract: The innervation of cerebral blood vessels by nerve fibers containing calcitonin gene-related peptide (CGRP) and the vasomotor effects of this peptide are described for a number of different mammalian species CGRP-immunoreactive nerve fibers were present in the adventitia of cerebral arteries in all species examined (guinea pig, cat, rabbit, rat, and mouse) Numerous perikarya containing CGRP immunoreactivity are demonstrable in the trigeminal ganglion of all species In the cerebral perivascular nerve fibers and in trigeminal perikarya, CGRP is often colocalized with substance P and neurokinin A Marked interspecies differences exist both in the density of CGRP-immunoreactive nerve fibers and in the cerebrovascular levels measured with radioimmunoassay The highest concentrations were observed in cerebral vessels from guinea pigs, the lowest concentration in rabbit vessels, and intermediate levels in the feline and human cerebral vasculature CGRP is a potent dilator of cerebral arteries in all species examined (human pial, feline middle cerebral, rabbit, guinea pig and rat basilar arteries) The concentration of CGRP eliciting half-maximal responses ranged from 04 nM (human pial artery) to 3 nM (rat and rabbit basilar arteries) Pretreatment of cerebral arteries with low concentrations of either substance P (01 nM) or neurokinin A (3 nM) attenuated slightly the CGRP-induced relaxations of guinea pig basilar arteries Calcitonin was found to be a very weak dilator of cerebral arteries from human and guinea pig Thus, cardiovascular nerve fibers containing CGRP appear to be present in all mammalian species (although to varying degrees) and CGRP is invariably a potent dilator of the cerebral arteries for all species

An efficient algorithm for the “optimal” stable marriage

Abstract: In an instance of size n of the stable marriage problem, each of n men and n women ranks the members of the opposite sex in order of preference. A stable matching is a complete matching of men and women such that no man and woman who are not partners both prefer each other to their actual partners under the matching. It is well known [2] that at least one stable matching exists for every stable marriage instance. However, the classical Gale-Shapley algorithm produces a marriage that greatly favors the men at the expense of the women, or vice versa. The problem arises of finding a stable matching that is optimal under some more equitable or egalitarian criterion of optimality. This problem was posed by Knuth [6] and has remained unsolved for some time. Here, the objective of maximizing the average (or, equivalently, the total) “satisfaction” of all people is used. This objective is achieved when a person's satisfaction is measured by the position of his/her partner in his/her preference list. By exploiting the structure of the set of all stable matchings, and using graph-theoretic methods, an O(n4) algorithm for this problem is derived.

Method for dominant selection in eucaryotic cells

Abstract: Recombinant DNA sequences which encode the complete amino acid sequence of a glutamine synthetase, vectors containing such sequences, and methods for their use, in particular as dominant selectable markers, for use in co-amplificiation of non-selected genes and in transforming host cell lines to glutamine independence.

Ultraclean air and antibiotics for prevention of postoperative infection. A multicenter study of 8,052 joint replacement operations.

Abstract: To determine the value of ultraclean air in operating rooms, 8,052 operations for total hip- or knee-joint replacement were followed up for 1-4 years. For operations done in ultraclean air, bacterial contamination of the wound, deep joint sepsis, and major wound sepsis were substantially less than for operations done in conventionally ventilated rooms. Sepsis was also less frequent when prophylactic antibiotics had been given. The two precautions acted independently so that the incidence of sepsis after operation in ultraclean air and with antibiotics was much less than that when either was used alone. Wound sepsis was associated with an enhanced risk of joint sepsis. Staphylococcus aureus was the commonest joint pathogen, but infections with other organisms, often considered to be of low pathogenicity, were almost as numerous. Most S. aureus infections were traced to sources in the operating room.

Abolition of the expression of inhibitory guanine nucleotide regulatory protein Gi activity in diabetes.

Abstract: Many cell-surface receptors for hormones appear to exert their effects on target cells by interacting with specific guanine nucleotide binding regulatory proteins (G-proteins) which couple receptors to their second-messenger signal generation systems. A common intracellular second messenger, which is used by many hormones, is cyclic AMP. This is produced by adenylate cyclase, whose activity is controlled by two G-proteins, Gs which mediates stimulatory effects and Gi inhibitory effects on adenylate cyclase activity1. In liver, the hormone glucagon increases intracellular cAMP concentrations by activating adenylate cyclase by a Gs-mediated process. This effect of glucagon is antagonised by the hormone insulin, although the molecular mechanism by which insulin elicits its actions is obscure. However, insulin receptors exhibit a tyrosyl kinase activity2 and appear to interact with G-proteins2,3, perhaps by causing phosphorylation of them4. In type I diabetes, circulating insulin levels are abnormally low, giving rise to gross perturbations of metabolism as well as to a variety of complications such as ionic disturbances, neuropathies of the nervous system, respiratory and cardiovascular aberrations and predispostion to infection5. We show here that experimentally-induced type I diabetes leads to the loss of expression of G{ in rat liver. As it has been suggested that Gi may couple receptors to K+-channels6,7 as well as mediating the inhibition of adenylate cyclase, aberrations in the control of expression of this key regulatory protein in type I diabetes may be expected to lead to pleiotropic effects.

Herpes simplex virus 1 protein kinase is encoded by open reading frame US3 which is not essential for virus growth in cell culture.

Abstract: Earlier reports have described a novel protein kinase in cells infected with herpes simplex or pseudorabies viruses. These novel enzymes were characterized by their acceptance of protamine as a substrate and by their differential chromatographic behavior in anion-exchange chromatography. We report that this activity was not present in extracts of uninfected cells or of cells infected with a mutant constructed so as to contain a deletion in the US3 open reading frame mapping in the small component of herpes simplex virus 1 DNA. The activity was present in extracts of cells infected with wild-type virus and with a recombinant in which the US3 open reading frame had been rescued. Our results are consistent with the observation reported earlier that the coding sequences predict an amino acid motif common to protein kinases and lead to the conclusion that the US3 open reading frame encodes a virus-specific protein kinase that is not required for virus growth in cells in culture.

Projections for strictness analysis

Abstract: Contexts have been proposed as a means of performing strictness analysis on non-flat domains. Roughly speaking, a context describes how much a sub-expression will be evaluated by the surrounding program. This paper shows how contexts can be represented using the notion of projection from domain theory. This is clearer than the previous explanation of contexts in terms of continuations. In addition, this paper describes finite domains of contexts over the non-flat list domain. This means that recursive context equations can be solved using standard fixpoint techniques, instead of the algebraic manipulation previously used.

Clinical features and management

Abstract: Cats suffering from this disease were first recognized in late 1981. During the early months of 1982 the number of cases increased dramatically, and reached a peak in July, when we saw as many cases as in the previous 6 months put together. There may have been a drop in numbers during the winter of 1982 but a large number of cats were affected during 1983. Cases are continuing to occur but I have no accurate figures on incidence. However, a number of interested colleagues in practice in various parts of the United Kingdom have agreed to log their cases during the next year and this should give us a better picture of incidence totals, plus any indications of regional and seasonal variations. The pattern of the disease does not appear to have altered since it first appeared. Usually it occurs sporadically, with one cat in a household affected. However, there have been a number of instances in which several kittens in a litter have been affected, and pairs of related or unrelated cats in the same house have become ill at the same time. In other cases individual cats in adjacent houses have become ill at the same time, and instances have occurred where another cat in a previously affected household has developed the disease up to 12 months later. Nevertheless, these occurrences have tended to be the exception rather than the rule. Country cats as well as town cats have been affected and the disease has occurred in animals kept permanently indoors as well as in those allowed total freedom. Domestic short-haired cats have outnumbered pure-bred cats affected by about 4 : 1, and males to females by 3 : 2. Seventy five per cent of affected cats have been less than 3 years old at the onset of the disease with an overall age range of 2 months to 11 years. In most cases the owner reports that the disease has developed quite suddenly. Not infrequently many of the major signs have appeared in less than 12 hours. In other cases (about 30 per cent) the onset is more prolonged, up to one week, with the cat becoming vaguely ill prior to the onset of recognizable signs. The presenting signs vary, but generally consist of one or more of dullness, anorexia, ‘vomiting’, and ocular changes become apparent early on. In some cases, the change from healthy normality to severely ill has occurred so quickly and dramatically that a road accident has been suspected.

The pentafunctional arom enzyme of Saccharomyces cerevisiae is a mosaic of monofunctional domains.

Abstract: The nucleotide sequence of the Saccharomyces cerevisiae ARO1 gene which encodes the arom multifunctional enzyme has been determined. The protein sequence deduced for the pentafunctional arom polypeptide is 1588 amino acids in length and has a calculated Mr of 174555. Functional regions within the polypeptide chain have been identified by comparison with the sequences of the five monofunctional Escherichia coli enzymes whose activities correspond with those of the arom multifunctional enzyme. The observed homologies demonstrate that the arom polypeptide is a mosaic of functional domains and are consistent with the hypothesis that the ARO1 gene evolved by the linking of ancestral E. coli-like genes.

A longitudinal study of social support and depression in unemployed men.

Abstract: Interviews were conducted with 49 men just after they had become unemployed, and with a matched sample of 49 employed men. Follow-up interviews took place 6–8 months later. At follow-up 20 originally unemployed men were still without work, and were significantly more depressed than the employed. Five of these 20, but no employed men, had become clinically depressed. In a multiple regression analysis there was a significant employment × social support interaction which indicated that depression scores at follow-up were higher in those who remained unemployed and who had little social contact with others in the month before losing their jobs. Depression becomes likely when people lose a source of social interaction that is important to their sense of worth, and have no alternative means of experiencing this worth in other relationships.

Isolation and Partial Characterization of an Adhesin from Candida albicans

Abstract: Candida albicans produces extracellular polymeric material (EP) which contains a mannoprotein adhesin. EP isolated from culture supernatants of C. albicans GDH 2346 consisted of a mixture of glycoprotein components and inhibited yeast adhesion to buccal epithelial cells by up to 60%. Partial purification of the adhesin was achieved by a two-step procedure involving chromatography of EP on concanavalin A-Sepharose and DEAE-cellulose. The purified adhesin inhibited adhesion to buccal cells 30 times more efficiently (on a weight basis) than unfractionated EP. Pretreatment of EP with heat, dithiothreitol or proteolytic enzymes either partially or completely destroyed its ability to inhibit adhesion, whereas pretreatment with sodium periodate or alpha-mannosidase had little or no effect. These results suggest that the protein portion of the mannoprotein adhesin is more important than the carbohydrate moiety in mediating yeast attachment to buccal epithelial cells.

Development of a Unipolar Converter for Variable Reluctance Motor Drives

Abstract: A new converter concept for driving the switched reluctance motor has been developed. This converter has only one switching device per phase, uses a unipolar dc supply, returns all the trapped energy to the source, and does not require bifilar windings; it is called a C-dump converter because the trapped energy is dumped in a capacitor and then returned to the dc source. The topology for several different C-dump converters is presented. In addition, the design and experimental results for a C-dump converter using a chopper to recover the energy dumped on the capacitor are presented.

Role of glycosides as epithelial cell receptors for Candida albicans.

Abstract: SUMMARY: The effect of various lectins and sugars on adhesion of five strains of Candida albicans to buccal and vaginal epithelial cells in vitro was investigated. Adhesion of C. albicans GDH 2346 was inhibited primarily by l-fucose and winged-pea lectin, whereas adhesion of strain GDH 2023 was inhibited by N-acetyl-d-glucosamine, or d-glucosamine, and wheat-germ agglutinin. Three other strains of C. albicans (MRL 3153, GRI 681 and GRI 682) gave results similar to those obtained with strain GDH 2346. Extracellular polymeric material (EP) isolated from strain GDH 2346 inhibited adhesion of strains MRL 3153, GRI 681 and GRI 682 by more than 50%, but that of strain GDH 2023 by only 30%. EP from strain GDH 2023 had little or no effect on the adhesion of any other yeast strain. Lectin-like proteins with affinities for l-fucose, N-acetyl-d-glucosamine and d-mannose were detected in EP from all five strains in different amounts. These results indicate that there are at least two types of adhesion mechanism and that glycosides containing l-fucose or N-acetyl-d-glucosamine can function as epithelial cell receptors for C. albicans.

Separation of the genetic loci for the H-Y antigen and for testis determination on human Y chromosome.

Abstract: The mammalian Y chromosome encodes a testis-determining factor (termed TDF in the human), a master regulator of sex differentiation Embryos with a Y chromosome develop testes and become males whereas embryos lacking a Y chromosome develop ovaries and become females Expression of H-Y, a minor histocompatibility antigen, may also be controlled by a gene on the Y chromosome, and it has been proposed that this antigen is the testis-determining factor We have tested the postulated identity of H-Y and TDF in the human H-Y typing with T cells was carried out on a series of sex-reversed humans (XX males and XY females), each shown by DNA hybridization to carry part but not all of the Y chromosome This deletion analysis maps the gene for H-Y to the long arm or centromeric region of the human Y chromosome, far from the TDF locus, which maps to the distal short arm

The Policy Process

Abstract: Until relatively recently it was not generally believed that the communist states possessed anything that could properly be called a ‘policy process’. The ruling communist parties, it was believed, simply issued decisions which were then handed over for implementation to the various subordinate bureaucracies — governmental, social and cultured, and economic. Party decisions were binding in all matters of this kind, and they were held to reflect the influence of ideology or of power politics within the leadership, but not, as in a Western country, of individuals or groups outside the leadership or of the institutions responsible for implementing the policies on which the leadership had decided. These institutions, after all, were staffed by communist party members, usually on the advice of the relevant party committee, and there was no shortage of sanctions, from the secret police to the threat of loss of employment, to make sure that they complied with the party’s directives. Policies, moreover, were believed to be relatively simple, the overriding priority being the highest possible rate of economic growth and more particularly of heavy industry. This was clearly close to the view of communist politics held by those who adhered to the totalitarian approach, with its emphasis on party dominance.

Nerve fibers containing neuropeptide Y in the cerebrovascular bed: immunocytochemistry, radioimmunoassay, and vasomotor effects.

Abstract: Perivascular nerve fibers containing neuropeptide Y (NPY)-like immunoreactivity were identified around cerebral blood vessels of human, cat, guinea pig, rat, and mouse. The major cerebral arteries were invested by dense plexuses; veins, small arteries, and arterioles were accompanied by few fibers. Removal of the superior cervical ganglion resulted in a reduction of NPY-like material in pial vessels and dura mater. Pretreatment with 6-hydroxydopamine or reserpine reduced the number of visible NPY fibers and the concentration of NPY in rat cerebral vessels. Sequential immunostaining with antibodies toward dopamine-beta-hydroxylase (DBH) (an enzyme involved in the synthesis of noradrenaline) and NPY revealed an identical localization of DBH and NPY in nerve cell bodies in the superior cervical ganglion and in perivascular fibers of pial blood vessels, suggesting their coexistence. Administration of NPY in vitro resulted in concentration-dependent contractions that were not modified by a sympathectomy. The contractions induced by noradrenaline, 5-hydroxytryptamine, and prostaglandin F2 alpha and the dilator responses to calcitonin gene-related peptide were not modified by NPY in rat cerebral arteries. However, the constrictor response to NPY was reduced by 70% in the presence of the calcium entry blocker nifedipine, and abolished following incubation in a calcium-free buffer. These data suggest an interaction of NPY at a postsynaptic site, which for induction of contraction may open calcium channels in the sarcolemma of cerebral arteries.

Adhesion of Candida species to epithelial surfaces.

Abstract: Successful colonization and infection of host tissues by the pathogenic Candida species depend upon the ability of these organisms to adhere to mucosal surfaces. The different species vary in their ability to adhere, and there is a clear correlation between adhesion and virulence. The mechanism of adhesion of the most pathogenic species, Candida albicans, to epithelial cells has been studied in detail and is thought to involve lectin-like interactions between specific binding molecules (adhesins) on the yeast surface and complementary receptor molecules on the epithelial cell surface. Current information suggests that the protein portion of mannoprotein located in fibrils on the yeast surface serves as the adhesin and interacts with glycoside receptors on epithelial cells. The evidence for this proposed mechanism is critically discussed.