The message of ‘The Other North Sea’

This paper explains the objectives of organising the symposium ‘The Other North Sea’. A major goal is the submission of the conclusions and content of this symposium to the North Sea Task Force, an initiative of the Second Conference on the Protection of the North Sea (London, 1987) which is responsible for preparing a Quality Status Report on the North Sea by mid-1993. The conclusions and recommendations of the symposium are summarised and presented to the North Sea Task Force in connection with the preparations for the 1993 Quality Status Report. The paper stresses the need to subdivide the North Sea into areas of ecological entity and underlines the advantages of using diatom and meiofauna assemblages as indicators for present and past environmental actors in sediment conditions. A plea is also made for the promotion of research to improve understanding of disturbance of sensory perception and behaviour as an ecologically relevant early warning signal. The major role of fisheries in inducing changes of seabird and harbour porpoise populations is highlighted.     

The New Health Practitioner — The Past as Prologue

The training and utilization of New Health Practitioners (NHP''s) has moved within a decade from a small tentative beginning in the mid-1960''s to a major health manpower policy issue. Its discussion transcends a number of important and emotionally charged areas including the role of various professions in providing health care services, the renaissance of primary care, the geographic and economic maldistribution of medical services, and the cost of care. It is valuable to highlight what is known, what is professed and what needs to be studied further about this issue.     

The Weaker Sex? The Propensity for Male-Biased Piglet Mortality

For the most part solutions to farm animal welfare issues, such as piglet mortality, are likely to lie within the scientific disciplines of environmental design and genetic selection, however understanding the ecological basis of some of the complex dynamics observed between parent and offspring could make a valuable contribution. One interesting, and often discussed, aspect of mortality is the propensity for it to be sex-biased. This study investigated whether known physiological and behavioural indicators of piglet survival differed between the sexes and whether life history strategies (often reported in wild or feral populations) relating to parental investment were being displayed in a domestic population of pigs. Sex ratio (proportion of males (males/males+females)) at birth was 0.54 and sex allocation (maternal investment measured as piglet birth weight/litter weight) was statistically significantly male-biased at 0.55 (t₃₅ = 2.51 P = 0.017), suggesting that sows invested more in sons than daughters during gestation. Despite this investment in birth weight, a known survival indicator, total pre-weaning male mortality was statistically significantly higher than female mortality (12% vs. 7% respectively z = 2.06 P = 0.040). Males tended to suffer from crushing by the sow more than females and statistically significantly more males died from disease-related causes. Although males were born on average heavier, with higher body mass index and ponderal index, these differences were not sustained. In addition male piglets showed impaired thermoregulation compared to females. These results suggest male-biased mortality exists despite greater initial maternal investment, and therefore reflects the greater susceptibility of this sex to causal mortality factors. Life history strategies are being displayed by a domestic population of pigs with sows in this study displaying a form of parental optimism by allocating greater resources at birth to males and providing an over-supply of this more vulnerable sex in expectation of sex-biased mortality.     

The GTM Analogy: The “Organismic” Metaphor Revisited?

Metaphors and analogies have long been used as heuristic and explanatory devices in the sciences. This focal review comments on the article "The Transmission of Genes and Culture: A Questionable Analogy" by Drs. Cladiere and Andre, and discusses the usefulness of the GTM analogy for understanding the transmission of culture.     

The α-ketoglutarate-dehydrogenase complex

Damage from oxidative stress and mitochondrial dysfunction occur together in many common neurodegenerative diseases. The enzymes that form the mitochondrial alpha-ketoglutarate- dehydrogenase complex (KGDHC), a key and arguably rate-limiting enzyme system of the tricarboxylic acid cycle, might mediate the interaction of these processes. KGDHC activity is reduced in numerous age-related neurodegenerative diseases and is diminished by oxidative stress. In Alzheimer's disease (AD), the reduction correlates highly to diminished mental performance. Thus, research has focused on the mechanisms by which select oxidants reduce KGDHC and the consequences of such a reduction. Diminished KGDHC in cells is associated with apoptosis without changes in the mitochondrial membrane potential. Studies of isolated mitochondria and of animal models suggest that a reduction in KGDHC can predispose to damage by other toxins that promote neurodegeneration. Diminished oxidative metabolism can be plausibly linked to pathological features of neurodegenerative diseases (e.g., reduced mental function, the plaques and tangles in AD). Thus, reductions in KGDHC might be central to the pathophysiology of these diseases. Studies of proteins, cells, animal models, and humans suggest that treatments to diminish, or bypass, the reduction in KGDHC might be beneficial in age-related neurodegenerative disorders.     

The initiation mess?

This review concerns the mechanisms which control initiation of chromosome replication in enterobacteria with respect to cell growth. Initiation control is commonly separated into positive and negative regulatory mechanisms. Four main points are advanced concerning these different aspects of initiation control. (i) The average concentration of the initiator protein DnaA is proportional to the origin concentration, i.e. the origin per cell mass ratio and, thus, inversely proportional to the very often used term of the 'initiation mass'. (ii) The time of initiation of chromosome replication in the cell cycle is set by DnaA protein accumulating to a threshold level, which in concert with a number of other factors allows for a co-operative formation of the initiation complex. (iii) The time of initiation is not determined by the interaction with these other factors or by the transient interaction between newly replicated origins ( oriC  ) and the cell surface. (iv) The aberrant initiation phenotype observed in various mutants, including dnaA (ts) mutants, might be due to a defective pre-initiation DnaA– oriC interaction or it might be due to a defect in the protection of newly initiated origins from reinitiation. Many of these points are discussed and evaluated in view of recent developments concerning the regulation of chromosome replication in Escherichia coli     

The Edible Molecule…

Pettingill, Olin Se wall, Jr. Another Penguin Summer New York: Charles Scribner's Sons, 1975 80 pp., $10.00 Reviewed by A. Gilbert Wright

Grant, Verne Genetics of Flowering Plants New York: Columbia University Press, 1975 514 pp., $20.00 Reviewed by Martin Labar

Gutnik, Martin J. Energy: Its Past, Its Present, Its Future Chicago: Childrens Press, 1975 46 pp., individuals $6.60, institutions $4.95 Reviewed by George G. Mallinson

Wild, Robin, and Jocelyn Wild How Animals Work for Us New York: Parents' Magazine Press 64 pp., $4.99, 1975 Reviewed by Harold W. Puffer

Morse, Roger A. Bees and Bee-Keeping Ithaca, N.Y.: Cornell University Press 295 pp., $13.50, 1975 Reviewed by W.L. Gojmerac

Heintze, Carl The Bottom of the Sea and Beyond New York: Thomas Nelson, Inc., 1975 144 pp., $5.95 Reviewed by Albert C. Jensen

Cottrell, Alan Portrait of Nature New York: Charles Scribner's Sons, 1975 236 pp., $9.95 Reviewed by Paul S. Cohen

Hart, Leslie A. How the Brain Works New York: Basic Books, 1975 260 pp., $10.50 Reviewed by Julie Ann Miller

Schneider, Herman Science Fun for You in a Minute or Two New York: McGraw-Hill Junior Books, 1975 64 pp., $4.72 Reviewed by Julian R. Brandou

Williamson, H.D. The Year of the Koala New York: Charles Scribner's Sons, 1975 209 pp., $8.95 Reviewed by Austin T. Hyde

Heady, Eleanor B. Plants on the Go: A Book about Reproduction and Seed Dispersal (Finding-out books) New York: Parent's Magazine Press, 1975 64 pp., $4.59 Reviewed by Herbert Grossman

Durden, Kent A Fine and Peaceful Kingdom New York: Simon and Schuster 160 pp., $7.95, 1975 Reviewed by Robert Deitchman     

The elusive π-helix

Central to protein architecture is the local arrangement or secondary structure of the polypeptide backbone. Thirty to forty percent of protein domains are α-helices with 3.6 residues per turn. π-Helices, in which the peptide chain is more loosely coiled (4.4 residues per turn), have also been proposed. However, such structures necessitate an energetically unfavorable ～1 Å central helical hole. We show that rather than being composed of idealized π-helices, helical regions formed from putative π-helices actually consist of a series of concatenated wide turns with unique elliptical configurations. These structures have a larger helical radius akin to that of a π-helix, but without the loss of favorable cross-core van der Waals interactions. This not only obviates the helical void, but also endows proteins with important functionalities, including metal ion coordination, enhanced flexibility and specific enzyme-substrate binding interactions.     

The Badge of Jiuzhai

1. The background is a maple leaf, whose vein is the transformation of the first letter of "Jiu", that is J. In the front, there is a waterfall, which is the transformati on of Z, the first letter of Zhai. This makes "Jiuzhai" obvious. The first letter of China, "C", is transformed into a globe, symbol-     

The social brain?

The notion that there is a 'social brain' in humans specialized for social interactions has received considerable support from brain imaging and, to a lesser extent, from lesion studies. Specific roles for the various components of the social brain are beginning to emerge. For example, the amygdala attaches emotional value to faces, enabling us to recognize expressions such as fear and trustworthiness, while the posterior superior temporal sulcus predicts the end point of the complex trajectories created when agents act upon the world. It has proved more difficult to assign a role to medial prefrontal cortex, which is consistently activated when people think about mental states. I suggest that this region may have a special role in the second-order representations needed for communicative acts when we have to represent someone else's representation of our own mental state. These cognitive processes are not specifically social, since they can be applied in other domains. However, these cognitive processes have been driven to ever higher levels of sophistication by the complexities of social interaction.     

The Nature of Materials

This first essay is about a pending marriage between biology and some of the technologies of engineering. It is a story of a long-standing flirtation that has been consummated a number of times, but never properly solemnised, despite repeated attempts, and no one is quite sure how many of the offspring, if any, have been viable. Whether the union will be blessed in the near future is anyone‘ s guess. In the hope of helping the marriage on its way, I start with four lucky things the bride has to wear at the wedding for the marriage to succeed, at least in one of the more recent Western traditions.