Showing papers by "Bedford College published in 1975"

Social Class and Psychiatric Disturbance among Women in an Urban Population

Abstract: While an association between social status and prevalence of psychiatric disurbance has often been reported, little has been established about aetiology or its significance for social class differences. In a survey of a random sample of women living in south London a large class difference in the prevalence of psychiatric disturbance was found. This difference is particularly great among women with young children at home. This paper examines why working class women have a greater prevalence of (i) conditions with an onset in the year before interview and (ii) conditions that have lasted longer than one year. Severe life-events and major long term difficulties occurring in the year before onset play an important aetiological role. However although these aetiological agents are more common among working class women, they only explain a small part of the social class differences. The class difference is essentially due not to the greater frequency of events and difficulties but to the much greater likelihood...

Physical cluster mechanics: Statistical thermodynamics and nucleation theory for monatomic systems

Abstract: We extend previous computations of mechanical stability of atomic microclusters to the realm of statistical thermodynamics, obtaining thermodynamic functions for small, solid-like Van der Waals clusters of less than some 100 atoms possessing non-crystalline structures of ‘polytetrahedral’ type. These are shown to be almost invariably at a thermodynamic advantage over alternative lattice structures of the same number of atoms, at least for the Lennard-Jones potential in the harmonic-oscillator/rigid-rotor approximation. The dependence of thermodynamic functions upon cluster size appears to be essentially monotonic in the number of internal degrees of freedom; although there are certain exceptional structures, particularly with icosahedral symmetry, there proves to be little evidence for the occurrence of ‘magic numbers’ for stability at any temperature and within the size-range considered. Particular attention is given to the heat capacity of model systems in relation to their vibrational spectra....

Relaxation of the Bernal model

Abstract: RANDOM packings of spheres serve as models for a variety of noncrystalline particulate and molecular aggregates, some of which, for example the amorphous phases of metals and alloys, offer abundant possibilities for the comparison of theory and experiment1–4. Nevertheless there remain significant discrepancies between the measured structural characteristics of real systems and the geometrical models considered by Bernal5, Cohen and Turnbull6 and others to be prototypes for the simple vitreous state. The most enduring of these is perhaps the difference in position and intensity between the two components of the split second peak in the radial distribution function observed in actual and artificial systems2–4. Attempts to remove this disagreement by variation of the algorithm used in computer-simulated packings have only been partially successful. In particular Sadoc et al.2 have noted that it is relatively easy to build in strong local density inhomogeneities associated with icosahedral arrangements7,8 and Connell has experimented with the packing of compressible spheres, showing that significant shifts in the radial distribution function result from the softening of the interatomic potential9.

The in situ phosphorylation of microtubular protein in brain cortex slices and related studies on the phosphorylation of isolated brain tubulin preparations.

Abstract: A number of recent reports indicate that cytoplasmic microtubules (or their protein subunits) may participate in physiological processes associated with nerve cell function. For example, it has been shown that drugs such as colchicine and the Vincn alkaloids, which selectively interact with microtubular protein from a wide variety of cell types (see Refs. 1 and 2 for recent reviews), can also interrupt the intracellular translocation of materials along the axons and dendrites of nerve cells,:'block synaptic (i or modify the electrical status of neuronal membranes.' Furthermore, the use of these drugs in tissue culture systems has led to the view that microtubular systems may play a n important role in the growth and differentiation of nerve cells.c.!' However, in interpreting the effects of drugs, such as colchicine, on physiological processes i n nerve cells, it seems worth while to consider recent data concerning the subcellular distribution of colchicine-binding receptors in nerve tissue,lo-lS which points to the existence of at least three main forms of microtubular proteins. Intact microtubular structures, which are particularly evident in situ within axonal, dendritic, and glial processes (where they may be stabilized through intertubular or microtubule-membrane interactions) I G would represent the polymerized form of tubulin. Second, there is present throughout nerve cells a pool of free subunits,'::, part of which may be in dynamic equilibrium with intact microtubules.Is Finally, o n the basis of very recent evidence, it now seems likely that a highly significant fraction of tubulin is associated with nerve cell membranes, particularly with synaptic membrane^,^^. l i where it appears to represent a major integral component of the synaptic apparatus.In* ?\

Effects of indole alkaloids and related compounds on the properties of brain microtubular protein.

Abstract: In contrast with results on the rat, in the rabbit no arteriovenous differences were found in the plasma concentrations of free choline, phosphatidylcholine and lysophosphatidylcholine. The phospholipid values agreed with those of Nelson (1967). Blood samples were taken at intervals and the blood volume was replaced by infusing a dextran solution in which blood cells from earlier samplings were suspended. After this procedure, however, it was observed that the concentration of free choline in the plasma rose. This may be related to the transfusion of separated cells suspended in dextran. The concentration of the two choline glycerophospholipids fell owing in part to the plasma dilution with dextran, although the percentage of lysophosphatidylcholine rose from 17.6 to 26.0% of the total phospholipids. An infusion of choline (lpmol/min per kg body weight) caused a considerable rise in the free choline concentration of plasma followed by a fall to the ‘dextran-stimulated’ level. A second choline infusion again caused a rise in the free choline concentration. Infusion of choline failed to prevent the gradual decline in lipid choline concentrations. Thus although the rat showed marked differences in the free choline concentration of jugular vein compared with the femoral artery, this could not be detected in the rabbit. In the rabbit, choline infusion raised the concentration of free choline but failed to prevent the fall in the concentration of plasma choline glycerophospholipids.

The word problem for free fields: a correction and an addendum

Abstract: In [1] it was claimed that the word problem for free fields with infinite centre can be solved. In fact it was asserted that if K is a skew field with infinite central subfield C , then the word problem in the free field on a set X over K can be solved, relative to the word problem in K . As G. M. Bergman has pointed out (in a letter to the author), it is necessary to specify rather more precisely what type of problem we assume to be soluble for K : We must be able to decide whether or not a given finite set in K is linearly dependent over its centre. This makes it desirable to prove that the free field has a corresponding property (and not merely a soluble word problem). This is done in §2; interestingly enough it depends only on the solubility of the word problem in the free field (cf. Lemma 2 and Theorem 1′ below). Bergman also notes that the proof given in [1] does not apply when K is finite-dimensional over its centre; this oversight is rectified in §4, while §3 lifts the restriction on C (to be infinite). However, we have to assume C to be the precise centre of K , and not merely a central subfield, as claimed in [1]. I am grateful to G. M. Bergman for pointing out the various inaccuracies as well as suggesting remedies.

The connection between an Euclidean Gauss Markov Vector Field and the Real Proca Wightman Field

Abstract: We construct an Euclidean Gauss Markov Vector Field which leads to the Real Proca Wightman Field describing particles of mass >0 and spin 1, for space-time dimension equal to 4

Handwriting and self-presentation.

Abstract: Summary Relations were examined between students' self-conceptions and handwriting-based inferences about academically relevant traits made by members of the academic population to whom the writers were unknown. There was good interjudge agreement for some traits. Agreement between handwriting judgments and writer self-ratings was significantly reduced when judgments were based on best rather than normal handwriting, suggesting suppression of self-revelation. When asked to do so, students successfully conveyed “false” impressions of named traits via handwriting. Handwriting can be regarded as a social act; Ss showed knowledge of how it can be modified by situational demands to effect differing kinds and degrees of self-presentation.

Evidence for neuronal control of ion transport in chironomid larvae.

Abstract: THE role of anal papillae in the uptake of sodium and chloride ions has been established in the closely related culicid and chironomid larvae1–6, but studies on the ultrastructure of these organs have been limited to the former group7–9. The sites of active ion transport are located on the apical membrane of the epidermal cells below the cuticle5,8,10. The mechanism by which ion transport is controlled in culicid larvae is most probably hormonal4,11 but there are indications that a different system operates in the chironomid larvae12–14. To investigate this possibility, the ultrastructure of the anal papillae of Chironomus riparius Meigen has been examined. Axons were clearly present suggesting that ion transport may be under neuronal control.

Primary neural induction as studied by scanning electron microscopy.

Abstract: Normal primary neural induction has been studied by scanning electron microscopy and the results compared with those obtained by TEM. Mesoderm cells are usually in contact with several other cells, both mesodermal and endodermal in origin. By SEM the ectoderm layer has been shown to be in contact with the underlying mesoderm cells. Tufts of fibrous basement membrane are also present between the two cell types. TEM specimens also show an intermediate basement membrane.

The approach to hard-sphere brownian motion: Variational eigenfunctions and evaluation of the Rayleigh-Fokker-Planck equation

Abstract: We present detailed tabulations of the first few eigenfunctions of the hard-sphere energy scattering kernel for a test-particle in a background heat-bath. Calculations, for a range of heat bath/test particle mass-ratios between 1 8 and 1 1024 , were carried out by a Rayleigh-Ritz method using the exact solutions of the hard-sphere Fokker-Planck equation as a basis set and supplement our previously-published results for the eigenvalues alone. The results, given as expansion coefficients in this representation thus also serve to verify the accuracy of the Fokker-Planck equation itself, the departure from this equation being reflected in the off-diagonal contributions in the Rayleigh-Ritz expansion eigenvectors. As expected, the tendency towards brownian motion behaviour with decrease in the mass-ratio parameter shows itself in a progressive convergence of a larger and larger subset of the true eigenfunctions to the corresponding Fokker-Planck set, beginning with the eigenvalue of lowest index. The class of probability distributions whose evolution is satisfactory predicted by the Fokker-Planck equation is then precisely the class that can be adequately expanded in terms of this incomplete subset. In keeping with the approximations introduced in the derivation of the Fokker-Planck equation and the qualitative nature of the hard-sphere eigenvalue spectrum, the results confirm quantitatively the considerable restrictions which the former imposes upon acceptable solution functions, excluding in particular both short-time behaviour and solutions of insufficient smoothness. A mean-square criterion for accuracy of the Fokker-Planck solutions is suggested and examined in the light of our numerical results.

The Electro-Osmotic Theory

Abstract: The other day I was talking to Dr. Charles Hebant and he told me he was hoping, after the conference, to go to Vancouver in search of a “beautiful little moss”. I was incautious enough to ask him if it really was a very beautiful moss. “All mosses are beautiful” he replied, with great feeling.

The Greek Dark Ages - V. R. d'A. Desborough: The Greek Dark Ages . Pp. 388; 60 pls., 39 figs., 5 maps and plans. London: Benn, 1972. Cloth, £5.

Abstract: Study of the History of Religion, p. 337), he wrote: 'it is well known that it is possible to take the Synoptic Gospeb and to find Rabbinic parallels for nearly all the moral teachings of Jesus, for his teaching of the Fatherhood of God, and of the attitude which man should take to God and to man. And yet the way in which all was presented made it effective as the pre-existent elements had never been.' Certainly too much has been made of superficial resemblances between pagan cults and Christian doctrine, but the embracing study of the world of popular thought from which Christianity was born has still to be written. It is inevitable that a collection of papers spanning over forty years should invite supplementation and correction. It is remarkable both how consistent and how persuasive Nock's judgements remained. I draw attention to a few minutiae, as Nock would have wished himself, in order simply that the debate should continue. Pp. 348 ff.; the paper on Seviri and Augustales is outdated by several contributions, notably Meiggs, Ostia, pp. 217 ff. P. 371: see Callimachus, Aetia fr. 2 (Pfeiffer). P. 386: the Claudian passage has been explored much more fully by A. Cameron, Claudian, pp. 306-7. P. 392: the use of K

Some Lyric Fragments Reconsidered

Abstract: I Want to comment on five passages where I have provoked disagreement by a previous discussion. In the first three, my discussion was in Philologus cx (1966), 152–4, and my critic is Bruno Gentili in Quaderni Urbinati iv (1967), 177–81. I was not the first to make an emendation in any of the three places, so that in defending the transmitted text Gentili is actually not only criticizing me but others such as Hermann, Naeke, O. Müller, Schoemann, Hunt, Murray, and Page.

Pomponius Mela Gunnar Ranstrand: (1) Pomponii Melae De Chorographia libri tres , (2) Textkritische Beiträge zu Pomponius Mela. (Studia Graeca et Latina Gothoburgensia, xxviii–xxix.) Pp. vi+122, 48. Gothenburg: Almqvist & Wiksell, 1971. Paper, Kr.35·15.

Abstract: GUNNAR RANSTRAND: ( I ) Pomponii Melae De Chorographia libri ires, (2) Textkritische Beitrdge zu Pomponius Mela. (Studia Graeca et Latina Gothoburgensia, xxviii-xxix.) Pp. vi+122, 48. Gothenburg: Almqvist & Wiksell, 1971. Paper, Kr.35.15. MELA'S compendium of geography, 'impeditum opus et facundiae minim* capax', must have been as tedious to edit as it is to read. But, tedium apart, the task here facing an editor was not exceptionally exacting. Mela's text does indeed contain some serious and unsolved problems, but it poses no general difficulty in recension. Again, though Mela's expression is occasionally perplexing, his thought is on the whole simple enough. Yet again, Mela has rarely, in recent times at least, attracted the attention of first-rate critics: much therefore remained to be done which any competent and painstaking editor could do. In these circumstances a new edition merely somewhat better than its predecessors would have merited only scant praise. Happily Ranstrand's edition is of a quality far above the average, and it may, without hesitation, be accepted as standard. He has in matters of substance as of detail effected many decisive and unquestionable improvements. He has from time to time shown insight and originality. His meticulous concern with his author's usage, his command of relevant information, his perception of the requirements of sense, and his stability of judgement place his work in the best tradition of Scandinavian scholarship.