Schizotypy, creativity and mating success in humans by Dr D Nettle and Ms HT Keenoo (rspb.2005.3349) Biologists have puzzled over how the genetic variants that predispose people to schizophrenia persist in the human gene pool, given that the effects of the disorder are so serious. A possible solution is the idea that these same variants can also enhance artistic creativity. Artistic creativity in turn has been hypothesized to increase sexual attractiveness. We investigated these ideas in 425 poets, artists and members of the public. We found that poets and artists share some (but not all) personality characteristics with schizophrenia patients, and, moreover, that they have more sexual partners than average. Thus, some of the personality traits predisposing to schizophrenia can actually be evolutionarily advantageous by increasing mating success. Contact: Dr D Nettle, Psychology, Brain and Behaviour, University of Newcastle, Henry Wellcome Building, NEWCASTLE, NE2 4HH
Proceedings B list continues below.
Journal of the Royal Society Interface
Evolution of hyperactivity, impulsivity, and cognitive diversity by Dr JOH Williams and Prof E Taylor The evolutionary status of ADHD is central to assessments of whether modern society created it, and is important in understanding its neurobiology and treatment. ADHD's association with a positively selected gene raises the possibility that ADHD itself is selected for. But previous suggestions of evolutionary benefits of ADHD have either been factually incorrect, or have not explained why, if it is useful, it remains confined to a minority. We present simulations showing that unpredictability, a key feature of ADHD, impairs individuals, but optimises foraging by the group. This is because risks are borne mainly by the individual, but the entire group benefits from behavioural and genetic experimentation. This 'group exploration' view accounts for the prevalence, sex & age distribution, severity distribution, and heterogeneity of ADHD.
Contact: Dr JOH Williams, Child & Adolescent Psychiatry, Institute of Psychiatry, De Crespigny Park, LONDON
Nanoprinting onto cells by Professor SG Curtis, Dr M Dalby and Dr N Gadegaard
Biological cells in tissue can react to the substratum nanotopography on which they are growing. These reactions may be of importance in the design of better metallic and polymer prostheses, eg. for hip replacement. In these examples a cell, perhaps 1/1000 cm long senses detail around it 100 to 300 times smaller. We have investigated this reaction. We find that the cell adopts the shape of the substratum so that the very fine detail is embossed onto it. The embossed surface details are signalled to the internal organisation of the cell-perhaps this is a new mode of signalling.
Contact: Professor A Curtis, Centre for Cell Engineering, University of Glasgow, Glasgow, G12 8QQ
Nano measurements with micro devices: mechanical properties of hydrated collagen fibrils by Professor SJE Eppell, Ms BNS Smith, Professor HK Kahn and Professor RB Ballarini
Predicting when bones may fracture and designing next generation spacecraft materials have something in common: the need to measure mechanical properties of nano-scale objects. Traditionally, large machines provide such measurements because they are stiff and can generate large forces. The new disciplines of Nanoscience and Nanotechnology require modernization of these machines. With technology similar to that used in manufacturing microchips, we produced a miniaturized mechanical testing device about the size of the width of a human hair. We used it to measure mechanical properties of a collagen fibril, a substructure in human bones ~100 times thinner than a human hair.
Contact: Professor SJE Eppell, Biomedical Engineering, Case Western Reserve University, 10900 Euclid Ave., CLEVELAND, OH 44106-7207, USA
Extending the dynamic range of phase contrast magnetic resonance velocity imaging using advanced higher-dimensional phase unwrapping algorithms by Dr MF Salfity, Professor JM Huntley, Mr MJ Graves, Dr O Marklund, Dr R Cusack and Dr DA Beauregard
Phase contrast magnetic resonance velocity imaging is a powerful non-invasive technique to measure in vivo blood flow. Its sensitivity is usually restricted to prevent the measured phase from being 'wrapped' onto the range –л to +л. Otherwise, the true phase must be estimated from the measured wrapped phase by a non-trivial phase unwrapping process. We investigate the performance of three different phase unwrapping algorithms. Compared to the traditional approach, the sensitivity can be increased by a factor of up to five times, which has the potential to improve the accuracy of stress measurements at the vessel walls to predict cardiovascular risk.
Contact: Dr MF Salfity, Mechanical and Manufacturing Engineering, Loughborough University, Ashby Road, LOUGHBOROUGH, LE11 3TU
Spatially resolved non-invasive chemical stimulation for modulation of signaling in reconstructed neuronal networks by Dr Y Mourzina, Mr A Steffen, Mr D Kaliaguine, Dr B Wolfrum, Dr P Shulte, Dr S Böcker-Meffert and Professor A Offenhäusser A biohybrid system is created, in which networks of neuronal cells are reconstructed on silicon chips and interfaced to a microfluidic system. Control over the network architecture and alignment of the network with the microfluidic interface is achieved by modification of the chip surface with cell-adhesive substances. The activity patterns of individual neurons in networks are manipulated by localized neurotransmitter application. This approach may be employed for the investigation of the influence of chemical gradients on network formation and signal processing in neuronal networks. Functional coupling of neuronal cells with silicon-based devices opens perspectives in information technologies and medical engineering.
Contact: Dr. Y Mourzina, Institute of Thin Films and Interfaces, Research Centre Juelich, JUELICH, 52425, GERMANY
Multiple feedback loop design in the tryptophan regulatory network of Escherichia coli suggests a paradigm for robust regulation of processes in series by Professor M Bhartiya, Mr N Chaudhary, Professor V Venkatesh and Professor J Doyle III
The evolutionary process has resulted in complex working designs of organisms to survive in uncertain environments. These designs are characterized by numerous molecular interactions resulting in a network. The bacterium Escherichia coli is capable of producing an amino acid called tryptophan that is essential for its survival. The machinery of the tryptophan network consists of process units arranged in series, similar to an assembly line in a manufacturing plant. To regulate the quantity of tryptophan produced, the network uses three distinct feedback loops that transmit information to the upstream process units. Our study reveals that this specific multiple feedback loop design enables the bacterium to maintain rapid and stable production of tryptophan even in presence of large disturbances in the individual process units. This superior performance, arising from a design principle, is intrinsic and therefore inherent to any similarly designed system, either natural or engineered. The study reverse engineers the design principle of the bacterium by demonstrating its beneficial attributes on a physical system. These evolutionary designs can suggest new paradigms that may be of relevance in future engineering endeavours.
Contact: Professor V Venkatesh, Chemical Engineering, IIT Bombay, Powai, MUMBAI, INDIA
Proceedings of the Royal Society B: Biological Sciences Continued…
The human brain is a detector of chemosensorily transmitted HLA-class I-similarity in same- and opposite-sex relations by Dr. BM Pause, Dr. K Krauel, Dipl.-Psych. C Schrader, Dipl.-Phys. B Sojka, Dr. E Westphal, Prof. W Müller-Ruchholtz and Prof. R Ferstl (rspb.2005.3342) Findings from animal and human research suggest that the major histocompatibility complex (MHC) plays an important role in the chemosensory communication between members of the same species. Our study investigated human odour-related brain responses and showed that the human brain processes body odours of people who are immunogenetically similar to the perceiver advantageously. When the odour donor and the odour perceiver where of the same sex, female and male participants showed locally different brain responses. We conclude that HLA-similarity is chemosensorily conveyed as a significant biological warning signal, acting in partner choice and male competitive behaviour.
Contact: Dr. BM Pause, Department of Psychology, University of Kiel, Olshausenstr. 62, KIEL, 24098, Germany
Cortisol levels are positively associated with pup-feeding rates in male meerkats by Dr A Carlson, Professor M Manser, Dr AJ Young, Dr AF Russell, Dr LL Sharpe, Prof AS McNeilly and Professor T H Clutton-Brock (rspb.2005.3087)
We investigated the biological basis of caring behaviour in wild groups of cooperatively breeding meerkats, a species in which adult 'helpers' provide care for the offspring of a dominant breeding pair. Correlational and experimental data revealed that significant differences in individual rates of pup-feeding were related, in part, to increased levels of the hormone cortisol; two other hormones previously thought to influence rates of offspring care, prolactin and testosterone, had no effect. Positive links between cooperative care and cortisol, a hormone primarily associated with physiological 'stress', suggest that small but significant increases in cortisol facilitate infant care by caregivers.
Contact: Dr A Carlson, Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
Selection for protection in an ant-plant mutualism: host sanctions, modularity, and a principal-agent game by Mr DP Edwards, Dr M Hassall, Professor W Sutherland and Dr. W. Yu (rspb.2005.3273)
How does one species get another species to do what it wants? For example, how do plants convince some animals to carry away seeds? We answer this question with an ant-plant symbiosis, where the plant houses an ant colony in exchange for protection against other insects that would eat the plant. We find that for each successful bout of protection the plant rewards its ants with a unit of housing, but withholds payment when the ant fails to protect. Thus, evolution solves the problem of cooperation by letting plants hire ants under a 'piecework' payment scheme that resembles many human employment contracts.
Contact: Mr DP Edwards, School of Biological Sciences, University of East Anglia, NORWICH, NR4 7TJ
Biology Letters
Genetic diversity in butterflies: interactive effects of habitat fragmentation and climate-driven range expansion by Dr JK Hill, Dr CL Hughes, Dr C Dytham and Dr JB Searle
Global climates are warming and some species are expanding their distributions to track these changes. We examined three British butterfly species in order to investigate the consequences of these range expansions on their genetic diversity. Overall, the two expanding species had lower genetic diversity than a non-expanding species. In addition, a decline in genetic diversity towards the northern boundary of the distribution was observed in the expanding species with the most fragmented breeding habitat. This suggests that some species currently expanding through human-modified fragmented landscapes may suffer reduced genetic diversity and thus be less able to adapt to new environmental changes in the future.
Contact: Dr JK Hill, Department of Biology, University of York, PO Box 373,York, YO10 5YW