Fellow of Queen's College

E-mail:
  john.pannell@plants.ox.ac.uk

Tel  +44 (0)1865 275145
Fax +44 (0)1865 275074

Last Modified: May 2012

Research in my lab is broadly centred on the areas of ecological genetics and plant evolutionary ecology. We are particularly interested in understanding (1) plant gender and sex allocation strategies; (2) the ecology, genetics and evolution of polyploidy, especially in its interaction with the sexual system; (3) the evolution of local adaptation in colonising plant species; and (4) the ecology and population genetics of metapopulations subject to repeated local extinctions and re-colonisations. We approach these topics from both a theoretical and an empirical perspective, with the latter both field- and lab-based. The lab is fully equipped for the use of DNA- and enzyme-based molecular markers to address ecological and evolutionary questions.

Projects currently underway in the lab

Testing models of sex allocation in subdivided populations
How should individuals divide their limited reproductive resources between the production and dispersal of pollen versus seeds when they occur in a fragmented population? We are currently addressing this question from a theoretical perspective through the construction of evolutionarily stable strategy (ESS) and quantitative genetic models of sex allocation for metapopulations, in which local populations are subject to dramatic fluctuations in their size, including extinction and colonisation events. The predictions made by this theory are being tested using the plant Mercurialis annua as a model system. This species shows remarkable variation in its sexual system in Europe, especially in the , where dioecious (the co-occurrence of males and females), monoecious (functional hermaphrodites) and androdioecious populations (the co-occurrence of males with hermaphrodites) are all widespread in different regions. The following studies are addressing various aspects of the theory of sex allocation in a metapopulation. These include work aimed at testing evolutionary models directly, as well as placing the study species into its evolutionary and phylogeographic context.

·  Comparisons of the patterns of sex allocation across several geographically independent transitions in the sexual system of Mercurialis annua in , and .

·  Estimates of inbreeding depression under dioecy, monoecy and androdioecy, using crossing designs and fitness essays in the field.

·  Longitudinal surveys of the occupancy, size and extent of multiple populations of M. annua distributed across geographically independent transitions in its sexual system.

·  Quantitative genetic analysis of sex allocation, including the use of selection experiments in which male frequencies are used as a selective agent increase and decrease the pollen production by hermaphrodites.

·  Ecophysiological studies of dioecious populations to estimate the cost of male versus female functions, in order to test theories of gender plasticity and secondary sexual dimorphism in plants.

·  A reconstruction of the polyploid history, including interspecific hybridisation, of the M. annua species complex within the context of the genus as a whole and using both chloroplast and nuclear DNA sequence variation.

·  An examination of the outcome of pollen dispersal across ploidy boundaries, where different sexual systems meet.

A spatially hierarchical analysis of the role of colonisation in plant metapopulations
Annual plant populations are notoriously patchy. Whether these patches should usefully be regarded as subpopulations or not is a largely operational question. However, the way in which patches become established, become extinct, or coalesce into a continuous population by expansion into one another can have a profound influence on the amount and patterns of genetic diversity maintained within a species. We are currently assessing the extent to which patches within spatially extended populations are spatially coherent, particularly with a view towards understanding why many self-fertilising annual plant populations maintain much less variation than one would expect on the basis of species-wide diversity.

The genetic and ecological significance of cryptic females in dioecious species
In dioecious species, it is usually only the males that produce pollen. However, several species in a range of different families are known in which males and ‘hermaphrodites’ occur at a ratio of 1:1. Species with even sex ratios must be functionally dioecious, and simple theory tells us that the apparent pollen producing ‘hermaphrodites’ are functioning only as females. We are interested in the functional significance of pollen produced by functional females in the Mediterranean species Fraxinus ornus. In collaboration with Miguel Verdú in , , we have shown that pollen from females is viable and fully capable of siring progeny, but that the progeny are less fit than those sired by males. Ongoing studies include:

·  Theoretical modelling of the hypothesis that ‘bad’ pollen is produced by females in response to selection for spiteful behaviour in local neighbourhoods.

·  Tests of the hypothesis that the reduced fitness of female-sired progeny may be an epigenetic outcome of differentially imprinted genomes by males and females as fathers, as opposed to the hypothesis that the sex-determination locus is linked to viability loci, which is known to be the case in several species of androdioecious crustaceans, for example.

The evolution of local adaptation in colonising plants
Colonising plants, like all organisms, are expected to become locally adapted to their environments as a response to natural selection. They are particularly interesting for at least two reasons. First, colonising species that are new arrivals in a region will be potentially subject to strong selection in their new environment and might be expected to show rapid responses to this selection. And second, their morphology, life history and physiology is expected to respond to natural selection not only locally, but also to selective forces acting at regional level during the process of colonising itself. Selection at the regional or metapopulation level is thus particularly likely to shape dispersal-related traits, including the mating system. These issues form the general background for the following studies in the lab:

·  Ecophysiological experiments investigating the evolution of local adaptation and ecological divergence in the plant Senecio squalidus, which was introduced to in 1799 and has spread rapidly to most parts of the country.

·  Quantitative genetics of local adaptation across altitudinal clines and species barriers in a hybrid zone on between Senecio aethnensis and S. chrysanthemifolius, the putative parents of S. squalidus.

·  Ecophysiological and reciprocal transplant experiments across ploidy boundaries in the plant Mercurialis annua in , where different sexual systems implicate selection on pollen dispersal and the mating system.

·  Metapopulation models of pollen interference between ploidy levels, to predict its impact on distribution range limits and the geographic position of contact zones.

The evolution and ecology of secondary sexual dimorphism in plants
Many dioecious species show dimorphism not only in their sex allocation and floral structures, but also in vegetative traits, with males and females often differing in their morphology and architecture, physiology and life history. Secondary sexual divergence has been much studied in animals, but our understanding of the underlying selective forces in plants are poorly understood. Can some of this variation be the result of sexual selection, or selective agents analogous to sexual selection? Or is it largely due to selection on the different reproductive roles carried out by males and females, which presumably have divergent costs and benefits? Ongoing studies in the lab include:

·  A comparative analysis of variation in sexual dimorphism in the genus Leucadendron, which occurs in the Cape of South Africa.

·  A comparative analysis of variation in sexual dimorphism in the genus Leucadendron, which occurs in the Cape of South Africa.

·  Experimental studies of sexual dimorphism in resource allocation in dioecious and androdioecious populations of Mercurialis annua.

·  The quantitative genetics of sexual dimorphism in Silene latifolia, particularly its interaction with local adaptation due to selection on loci transmitted through different genomic compartments

The evolution of plant-plant signalling strategies for gender determination
Because plants are sessile, their success depends critically on an ability to respond plastically to changes in their environment. For example, they respond to light quality, day length, soil nutrient availability, herbivory, etc. Such responses typically maximise growth and survivorship in a given context, but to what extent is phenotypic plasticity used to maximise mating and reproductive success? In many animal species, individuals are known to modify their morphology and behaviour in response to local mating opportunities. Given that the mating success of plants, too, should depend on local mate availability, we might expect natural selection to have favoured a similar ability to switch gender in response to perceived opportunities. We are currently following up on pilot studies conducted in our lab that point to the use of chemical signals in the soil to influence the gender of conspecific neighbours of the plant Mercurialis annua. Our aims include:

·  The characterisation of the nature of the responses elecited by soil- and air-borne signals.

·  The identification of the chemicals responsible.

Perry, L.E, Pannell, J.R, Dorken, M.E. (2012) Two's company, three's a crowd: Experimental evaluation of the evolutionary maintenance of trioecy in Mercurialis annua (Euphorbiaceae) PLoS ONE. 7 (4):.
doi:10.1371/journal.pone.0035597.

Hesse, E, Pannell, J.R. (2011) Sexual dimorphism in a dioecious population of the wind-pollinated herb Mercurialis annua: The interactive effects of resource availability and competition Annals of Botany. 107 (6): pp 1039-1045.
doi:10.1093/aob/mcr046.

Hesse, E, Pannell, J.R. (2011) Sexual dimorphism in androdioecious Mercurialis annua, a wind-pollinated herb International Journal of Plant Sciences. 172 (1): pp 49-59.
doi:10.1086/657279.

Hesse, E, Pannell, J.R. (2011) Density-dependent pollen limitation and reproductive assurance in a wind-pollinated herb with contrasting sexual systems Journal of Ecology. 99 (6): pp 1531-1539.
doi:10.1111/j.1365-2745.2011.01880.x.

Korbecka, G, Hamilton, A, Pannell, J.R. (2011) Mixed mating in androdioecious Mercurialis annua inferred using progeny arrays and diploid-acting microsatellite loci in a hexaploid background Annals of Botany. 107 (6): pp 1057-1061.
doi:10.1093/aob/mcr028.

Moore, J.C, Pannell, J.R. (2011) Sexual selection in plants Current Biology. 21 (5):.
doi:10.1016/j.cub.2010.12.035.

Pfeiffer, T, Roschanski, A.M, Pannell, J.R, Korbecka, G, Schnittler, M. (2011) Characterization of microsatellite loci and reliable genotyping in a polyploid plant, Mercurialis perennis (Euphorbiaceae) Journal of Heredity. 102 (4): pp 479-488.
doi:10.1093/jhered/esr024.

Sanchez, Vilas J, Pannell, J.R. (2011) Sex-differential herbivory in androdioecious Mercurialis annua. PloS one. 6 (7):.
doi:10.1371/journal.pone.0022083.

Sanchez, Vilas J, Pannell, J.R. (2011) Sexual dimorphism in resource acquisition and deployment: Both size and timing matter Annals of Botany. 107 (1): pp 119-126.
doi:10.1093/aob/mcq209.

Sanchez-Vilas, J, Turner, A, Pannell, J.R. (2011) Sexual dimorphism in intra- and interspecific competitive ability of the dioecious herb Mercurialis annua Plant Biology. 13 (1): pp 218-222.
doi:10.1111/j.1438-8677.2010.00408.x.

Vilas, J.S, Pannell, J.R. (2011) Sex-differential herbivory in androdioecious Mercurialis annua PLoS ONE. 6 (7):.
doi:10.1371/journal.pone.0022083.

Dufay, M, Pannell, J.R. (2010) The effect of pollen versus seed flow on the maintenance of nuclear-cytoplasmic gynodioecy Evolution. 64 (3): pp 772-784.
doi:10.1111/j.1558-5646.2009.00847.x.

Harris, M.S, Pannell, J.R. (2010) Canopy seed storage is associated with sexual dimorphism in the woody dioecious genus Leucadendron Journal of Ecology. 98 (2): pp 509-515.
doi:10.1111/j.1365-2745.2009.01623.x.

Korbecka, G, Rymer, P.D, Harris, S.A, Pannell, J.R. (2010) Solving the problem of ambiguous paralogy for marker loci: Microsatellite markers with diploid inheritance in allohexaploid mercurialis annua (Euphorbiaceae) Journal of Heredity. 101 (4): pp 504-511.
doi:10.1093/jhered/esq026.

Pannell, J.R, Korbecka, G. (2010) Mating-system evolution: Rise of the irresistible males Current Biology. 20 (11): pp 482-484.
doi:10.1016/j.cub.2010.04.033.

Pujol, B, Obbard, D.J, Pannell, J.R. (2010) Symptoms of population range expansion: Lessons from phenotypic and genetic differentiation in hexaploid Mercurialis annua Plant Ecology and Diversity. 3 (2): pp 103-108.
doi:10.1080/17550874.2010.516027.

Sanchez-Vilas, J, Pannell, J.R. (2010) Differential niche modification by males and females of a dioecious herb: Extending the Jack Sprat effect Journal of Evolutionary Biology. 23 (10): pp 2262-2266.
doi:10.1111/j.1420-9101.2010.02089.x.

Zhou, S.-R, Pannell, J.R. (2010) Inbreeding depression and genetic load at partially linked loci in a metapopulation Genetics Research. 92 (2): pp 127-140.
doi:10.1017/S0016672310000133.

Zhou, S, Zhou, C, Pannell, J.R. (2010) Genetic load, inbreeding depression and heterosis in an age-structured metapopulation Journal of Evolutionary Biology. 23 (11): pp 2324-2332.
doi:10.1111/j.1420-9101.2010.02091.x.

Allan, E, Pannell, J.R. (2009) Rapid divergence in physiological and life-history traits between northern and southern populations of the British introduced neo-species, Senecio squalidus Oikos. 118 (7): pp 1053-1061.
doi:10.1111/j.1600-0706.2009.17135.x.

Bernasconi, G, Antonovics, J, Biere, A, Charlesworth, D, Delph, L.F, Filatov, D, Giraud, T, Hood, M.E, Marais, G.A.B, McCauley, D, Pannell, J.R, Shykoff, J.A, Vyskot, B, Wolfe, L.M, Widmer, A. (2009) Silene as a model system in ecology and evolution Heredity. 103 (1): pp 5-14.
doi:10.1038/hdy.2009.34.

Dorken, M.E, Pannell, J.R. (2009) Hermaphroditic Sex Allocation Evolves When Mating Opportunities Change Current Biology. 19 (6): pp 514-517.
doi:10.1016/j.cub.2009.01.067.

Eppley, S.M, Pannell, J.R. (2009) Inbreeding depression in dioecious populations of the plant Mercurialis annua: comparisons between outcrossed progeny and the progeny of self-fertilized feminized males Heredity. 102 (6): pp 600-608.
doi:10.1038/hdy.2009.21.

Harris, S.-R, Henbest, K.B, Maeda, K, Pannell, J.R, Timmel, C.R, Hore, P.J, Okamoto, H. (2009) Effect of magnetic fields on cryptochrome-dependent responses in Arabidopsis thaliana Journal of the Royal Society Interface. 6 (41): pp 1193-1205.
doi:10.1098/rsif.2008.0519.

Pannell, J.R. (2009) Mating-System Evolution: Succeeding by Celibacy Current Biology. 19 (21):.
doi:10.1016/j.cub.2009.09.030.

Pannell, J.R. (2009) Mating-System Evolution: Genies from a Bottleneck Current Biology. 19 (9):.
doi:10.1016/j.cub.2009.03.031.

Pannell, J.R, Pujol, B. (2009) The paradoxical spread of a new Y chromosome - a novel explanation Trends in Ecology and Evolution. 24 (2): pp 59-63.
doi:10.1016/j.tree.2008.09.013.

Pannell, J.R. (2009) On the problems of a closed marriage: Celebrating Darwin 200 Biology Letters. 5 (3): pp 332-335.
doi:10.1098/rsbl.2009.0142.

Pujol, B, Zhou, S.-R, Vilas, J.S, Pannell, J.R. (2009) Reduced inbreeding depression after species range expansion Proceedings of the National Academy of Sciences of the United States of America. 106 (36): pp 15379-15383.
doi:10.1073/pnas.0902257106.

Dorken, M.E, Pannell, J.R. (2008) Density-dependent regulation of the sex ratio in an annual plant American Naturalist. 171 (6): pp 824-830.
doi:10.1086/587524.

Gleiser, G, Segarra-Moragues, J.G, Pannell, J.R, Verdu, M. (2008) Siring success and paternal effects in heterodichogamous Acer opalus Annals of Botany. 101 (7): pp 1017-1026.
doi:10.1093/aob/mcn030.

Gleiser, G, Verdu, M, Segarra-Moragues, J.G, Gonzalez-Martinez, S.C, Pannell, J.R. (2008) Disassortative mating, sexual specialization, and the evolution of gender dimorphism in heterodichogamous Acer opalus Evolution. 62 (7): pp 1676-1688.
doi:10.1111/j.1558-5646.2008.00394.x.

Harris, M.S, Pannell, J.R. (2008) Roots, shoots and reproduction: Sexual dimorphism in size and costs of reproductive allocation in an annual herb Proceedings of the Royal Society B: Biological Sciences. 275 (1651): pp 2595-2602.
doi:10.1098/rspb.2008.0585.

Janko, K, Drozd, P, Flegr, J, Pannell, J.R. (2008) Clonal turnover versus clonal decay: A null model for observed patterns of asexual longevity, diversity and distribution Evolution. 62 (5): pp 1264-1270.
doi:10.1111/j.1558-5646.2008.00359.x.

Pannell, J.R, Dorken, M.E, Pujol, B, Berjano, R. (2008) Gender variation and transitions between sexual systems in Mercurialis annua (Euphorbiaceae) International Journal of Plant Sciences. 169 (1): pp 129-139.
doi:10.1086/523360.

Pannell, J.R. (2008) Consequences of inbreeding depression due to sex-linked loci for the maintenance of males and outcrossing in branchiopod crustaceans Genetics Research. 90 (1): pp 73-84.
doi:10.1017/S0016672307008981.

Pujol, B, Wilson, A.J, Ross, R.I.C, Pannell, J.R. (2008) Are QST-FST comparisons for natural populations meaningful? Molecular Ecology. 17 (22): pp 4782-4785.
doi:10.1111/j.1365-294X.2008.03958.x.

Pujol, B, Pannell, J.R. (2008) Reduced responses to selection after species range expansion Science. 321 (5885): pp 96.
doi:10.1126/science.1157570.

Buggs, R.J.A, Pannell, J.R. (2007) Ecological differentiation and diploid superiority across a moving ploidy contact zone Evolution. 61 (1): pp 125-140.
doi:10.1111/j.1558-5646.2007.00010.x.

Dorken, M.E, Pannell, J.R. (2007) The maintenance of hybrid zones across a disturbance gradient Heredity. 99 (1): pp 89-101.
doi:10.1038/sj.hdy.6800969.

Eppley, S.M, Pannell, J.R. (2007) Density-dependent self-fertilization and male versus hermaphrodite siring success in an androdioecious plant Evolution. 61 (10): pp 2349-2349.
doi:10.1111/j.1558-5646.2007.00195.x.

Eppley, S.M, Pannell, J.R. (2007) Sexual systems and measures of occupancy and abundance in an annual plant: Testing the metapopulation model American Naturalist. 169 (1): pp 20-28.
doi:10.1086/509944.

Pannell, J.R. (2007) Dispersal Ecology: Where Have All the Seeds Gone? Current Biology. 17 (10):.
doi:10.1016/j.cub.2007.03.021.

Buggs, R.J.A, Pannell, J.R. (2006) Rapid Displacement of a Monoecious Plant Lineage Is Due to Pollen Swamping by a Dioecious Relative Current Biology. 16 (10): pp 996-1000.
doi:10.1016/j.cub.2006.03.093.

Obbard, D.J, Harris, S.A, Pannell, J.R. (2006) Simple allelic-phenotype diversity and differentiation statistics for allopolyploids Heredity. 97 (4): pp 296-303.
doi:10.1038/sj.hdy.6800862.

Obbard, D.J, Pannell, J.R, Harris, S.A. (2006) Mercurialis canariensis (Euphorbiaceae), a new endemic to the Canary Islands Kew Bulletin. 61 (1): pp 99-106

Obbard, D.J, Harris, S.A, Buggs, R.J.A, Pannell, J.R. (2006) Hybridization, polyploidy, and the evolution of sexual systems in Mercurialis (Euphorbiaceae) Evolution. 60 (9): pp 1801-1815.
doi:10.1554/06-104.1.

Obbard, D.J, Harris, S.A, Pannell, J.R. (2006) Sexual systems and population genetic structure in an annual plant: Testing the metapopulation model American Naturalist. 167 (3): pp 354-366

Pannell, J.R, Dorken, M.E. (2006) Colonisation as a common denominator in plant metapopulations and range expansions: Effects on genetic diversity and sexual systems Landscape Ecology. 21 (6): pp 837-848.
doi:10.1007/s10980-005-5389-7.

Pannell, J.R, Verdu, M. (2006) The evolution of gender specialization from dimorphic hermaphroditism: Paths from heterodichogamy to gynodioecy and androdioecy Evolution. 60 (4): pp 660-673.
doi:10.1554/05-481.1.

Verdu, M, Gonzalez-Martinez, S.C, Montilla, A.I, Mateu, I, Pannell, J.R. (2006) Ovule discounting in an outcrossing, cryptically dioecious tree Evolution. 60 (10): pp 2056-2063.
doi:10.1554/06-236.1.

Pannell, J.R, Dorken, M.E, Eppley, S.M. (2005) 'Haldane's Sieve' in a metapopulation: Sifting through plant reproductive polymorphisms Trends in Ecology and Evolution. 20 (7): pp 374-379.
doi:10.1016/j.tree.2005.05.004.

Pannell, J.R. (2005) Phenotypic plasticity and a functional vs genetic perspective of plant gender New Phytologist. 168 (3): pp 506-509.
doi:10.1111/j.1469-8137.2005.01579.x.

Pannell, J.R, Eppley, S.M. (2004) Intraorganismal genetic heterogeneity: Is it a useful concept? Journal of Evolutionary Biology. 17 (6): pp 1180-1181.
doi:10.1111/j.1420-9101.2004.00810.x.

Pannell, J.R, Obbard, D.J, Buggs, R.J.A. (2004) Polyploidy and the sexual system: What can we learn from Mercurialis annua? Biological Journal of the Linnean Society. 82 (4): pp 547-560

Verdu, M, Montilla, A.I, Pannell, J.R. (2004) Paternal effects on functional gender account for cryptic dioecy in a perennial plant Proceedings of the Royal Society - Biological Sciences (Series B). 271 (1552): pp 2017-2023.
doi:10.1098/rspb.2004.2836.

Lopez-Almansa, J.C, Pannell, J.R, Gil, L. (2003) Female sterility in Ulmus minor (Ulmaceae): A hypothesis invoking the cost of sex in a clonal plant American Journal of Botany. 90 (4): pp 603-609

Pannell, J.R, Obbard, D.J. (2003) Probing the primacy of the patch: What makes a metapopulation? Journal of Ecology. 91 (3): pp 485-488

Pannell, J.R. (2003) Coalescence in a metapopulation with recurrent local extinction and recolonization Evolution. 57 (5): pp 949-961

Pannell, J.R. (2002) The evolution and maintenance of androdioecy Annual Review of Ecology and Systematics. 33: pp 397-425.
doi:10.1146/annurev.ecolsys.33.010802.150419.

Pannell, J.R. (2002) What is functional androdioecy? Functional Ecology. 16 (6): pp 862-865

Sleeman, J.D, Dudley, S.A, Pannell, J.R, Barrett, S.C.H. (2002) Responses of carbon acquisition traits to irradiance and light quality in Mercurialis annua (Euphorbiaceae): Evidence for weak integration of plastic responses American Journal of Botany. 89 (9): pp 1388-1400

Pannell, J.R, Barrett, S.C.H. (2001) Effects of population size and metapopulation dynamics on a mating-system polymorphism Theoretical Population Biology. 59 (2): pp 145-155.
doi:10.1006/tpbi.2000.1496.

Pannell, J.R. (2000) Evolution in subdivided populations Trends in Ecology and Evolution. 15 (3): pp 90-92.
doi:10.1016/S0169-5347(99)01777-2.

Pannell, J.R. (2000) A hypothesis for the evolution of androdioecy: The joint influence of reproductive assurance and local mate competition in a metapopulation Evolutionary Ecology. 14 (3): pp 195-211.
doi:10.1023/A:1011082827809.

Pannell, J.R, Ojeda, F. (2000) Patterns of flowering and sex-ratio variation in the Mediterranean shrub Phillyrea angustifolia (Oleaceae): Implications for the maintenance of males with hermaphrodites Ecology Letters. 3 (6): pp 495-502.
doi:10.1046/j.1461-0248.2000.00173.x.

Pannell, J.R, Charlesworth, B. (2000) Effects of metapopulation processes on measures of genetic diversity Philosophical Transactions of the Royal Society of London Series B Biological Sciences. 355 (1404): pp 1851-1864.
doi:10.1098/rstb.2000.0740.

Pannell, J.R, Charlesworth, B. (1999) Neutral genetic diversity in a metapopulation with recurrent local extinction and recolonization Evolution. 53 (3): pp 664-676

Pannell, J. (1997) Mixed genetic and environmental sex determination in an androdioecious population of Mercurialis annua Heredity. 78 (1): pp 50-56.
doi:10.1038/sj.hdy.6881080.

Pannell, J. (1997) Variation in sex ratios and sex allocation in androdioecious Mercurialis annua Journal of Ecology. 85 (1): pp 57-69

Pannell, J. (1997) Widespread functional androdioecy in Mercurialis annua L. (Euphorbiaceae) Biological Journal of the Linnean Society. 61 (1): pp 95-116.
doi:10.1006/bijl.1996.0117.

Pannell, J. (1997) The maintenance of gynodioecy and androdioecy in a metapopulation Evolution. 51 (1): pp 10-20

Pannell, J.R, Myerscough, P.J. (1993) Canopy-stored seed banks of Allocasuarina distyla and A. nana in relation to time since fire Australian Journal of Botany. 41 (1): pp 1-9

M. Dorken, Trent University, Canada
S. Eppley, University of Oregon
R. Freckleton, Sheffield, UK
M. Verdu, CSIC, Valencia, Spain
S. Weeks, Akron University, Ohio

PAST MEMBERS OF RESEARCH GROUP

Dr. Sarah M. Eppley
Dr. Marcel Dorken
Dr. Darren Obbard
Dr. Richard J.A. Buggs
Dr. Mark Harris
Dr. Shurong Zhou
Dr. Gill Campbell
Dr. Paul Rymer