50 results on '"Wade, M. J"'
Search Results
2. MI-Sim: A MATLAB Package for the Numerical Analysis of Microbial Ecological Interactions
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Wade, M. J., Oakley, J., Harbisher, S., Parker, N. G., and Dolfing, J.
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Quantitative Biology - Quantitative Methods ,Mathematics - Dynamical Systems - Abstract
Food-webs and other classes of ecological network motifs, are a means of describing feeding relationships between consumers and producers in an ecosystem. They have application across scales where they differ only in the underlying characteristics of the organisms and substrates describing the system. Mathematical modelling, using mechanistic approaches to describe the dynamic behaviour and properties of the system through sets of ordinary differential equations, has been used extensively in ecology. Models allow simulation of the dynamics of the various motifs and their numerical analysis provides a greater understanding of the interplay between the system components and their intrinsic properties. We have developed the MI-Sim software for use with MATLAB to allow a rigorous and rapid numerical analysis of several common ecological motifs. MI-Sim contains a series of the most commonly used motifs such as cooperation, competition and predation. It does not require detailed knowledge of mathematical analytical techniques and is offered as a single graphical user interface containing all input and output options. The tools available in the current version of MI-Sim include model simulation, steady- state existence and stability analysis, and basin of attraction analysis. The software includes seven ecological interaction motifs and seven growth function models. Unlike other system analysis tools, MI-Sim is designed as a simple and user-friendly tool specific to ecological population type models, allowing for rapid assessment of their dynamical and behavioural properties., Comment: 15 pages, 3 figures
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- 2016
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3. Emergent behaviour in a chlorophenol-mineralising three-tiered microbial `food web'
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Wade, M. J., Pattinson, R. W., Parker, N. G., and Dolfing, J.
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Quantitative Biology - Populations and Evolution - Abstract
Anaerobic digestion enables the water industry to treat wastewater as a resource for generating energy and recovering valuable by-products. The complexity of the anaerobic digestion process has motivated the development of complex models. However, this complexity makes it intractable to pin-point stability and emergent behaviour. Here, the widely used Anaerobic Digestion Model No. 1 (ADM1) has been reduced to its very backbone, a syntrophic two-tiered microbial food chain and a slightly more complex three-tiered microbial food web, with their stability analysed as function of the inflowing substrate concentration and dilution rate. Parameterised for phenol and chlorophenol degradation, steady-states were always stable and non-oscillatory. Low input concentrations of chlorophenol were sufficient to maintain chlorophenol- and phenol-degrading populations but resulted in poor conversion and a hydrogen flux that was too low to sustain hydrogenotrophic methanogens. The addition of hydrogen and phenol boosted the populations of all three organisms, resulting in the counterintuitive phenomena that (i) the phenol degraders were stimulated by adding hydrogen, even though hydrogen inhibits phenol degradation, and (ii) the dechlorinators indirectly benefitted from measures that stimulated their hydrogenotrophic competitors; both phenomena hint at emergent behaviour., Comment: 19 pages, 8 figures
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- 2015
4. Suitability of aircraft wastewater for pathogen detection and public health surveillance
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Jones, D.L., Rhymes, J.M., Wade, M. J., Kevill, J.L., Malham, S.K., Grimsley, J.M.S., Doyle, C., Weightman, A.J., Farkas, K., Jones, D.L., Rhymes, J.M., Wade, M. J., Kevill, J.L., Malham, S.K., Grimsley, J.M.S., Doyle, C., Weightman, A.J., and Farkas, K.
- Abstract
International air travel is now widely recognised as one of the primary mechanisms responsible for the transnational movement and global spread of SARS-CoV-2. Monitoring the viral load and novel lineages within human-derived wastewater collected from aircraft and at air transport hubs has been proposed as an effective way to monitor the importation frequency of viral pathogens. The success of this approach, however, is highly dependent on the bathroom and defecation habits of air passengers during their journey. In this study of UK adults (n = 2103), we quantified the likelihood of defecation prior to departure, on the aircraft and upon arrival on both short- and long-haul flights. The results were then used to assess the likelihood of capturing the signal from infected individuals at UK travel hubs. To obtain a representative cross-section of the population, the survey was stratified by geographical region, gender, age, parenting status, and social class. We found that an individual's likelihood to defecate on short-haul flights (< 6 h in duration) was low (< 13 % of the total), but was higher on long-haul flights (< 36 %; > 6 h in duration). This behaviour pattern was higher among males and younger age groups. The maximum likelihood of defecation was prior to departure (< 39 %). Based on known SARS-CoV-2 faecal shedding rates (30–60 %) and an equal probability of infected individuals being on short- (71 % of inbound flights) and long-haul flights (29 %), we estimate that aircraft wastewater is likely to capture ca. 8–14 % of SARS-CoV-2 cases entering the UK. Monte Carlo simulations predicted that SARS-CoV-2 would be present in wastewater on 14 % of short-haul flights and 62 % of long-haul flights under current pandemic conditions. We conclude that aircraft wastewater alone is insufficient to effectively monitor all the transboundary entries of faecal-borne pathogens but can form part of a wider strategy for public heath surveillance at national borders.
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- 2022
5. Group Selection on a Quantitative Character
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Slatkin, M. and Wade, M. J.
- Published
- 1978
6. Paradox of Mother's Curse and the Maternally Provisioned Offspring Microbiome
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Wade, M. J., primary
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- 2014
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7. Maternal Adjustment of the Sex Ratio in Broods of the Broad-Horned Flour Beetle, Gnathocerus cornutus
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Cruickshank, T., primary and Wade, M. J., additional
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- 2012
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8. Bateman (1948): pioneer in the measurement of sexual selection
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Wade, M J, primary and Shuster, S M, additional
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- 2010
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9. Genetic Differentiation among Wild Populations of Tribolium castaneum Estimated Using Microsatellite Markers
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Drury, D. W., primary, Siniard, A. L., additional, and Wade, M. J., additional
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- 2009
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10. Don't Throw Bateman Out with the Bathwater!
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Wade, M. J., primary
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- 2005
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11. A comparison of health-related quality of life of elderly and younger insulin-treated adults with diabetes
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Trief, P. M., primary, Wade, M. J., additional, Pine, D., additional, and Weinstock, R. S., additional
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- 2003
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12. The population dynamics of maternal-effect selfish genes.
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Wade, M J, primary and Beeman, R W, additional
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- 1994
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13. Analysis of autosomal polygenic variation for the expression of Haldane's rule in flour beetles.
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Wade, M J, primary, Johnson, N A, additional, and Wardle, G, additional
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- 1994
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14. Female copying increases the variance in male mating success.
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Wade, M J, primary and Pruett-Jones, S G, additional
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- 1990
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15. Cytoplasmically inherited reproductive incompatibility in Tribolium flour beetles: the rate of spread and effect on population size.
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Stevens, L, primary and Wade, M J, additional
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- 1990
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16. Device for quantitative cytochemistry: a computerized scanning microdensitometer 'grain counter'.
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Markovic, N S, Lipkin, L E, Markovic, O S, and Wade, M J
- Abstract
A computerized scanning microdensitometer and autoradiographic grain counter was able to provide quantitative data on the cytochemical final reaction product formed within a single cell and also quantitate the kinetics of its formation. Optical density and area measurements were performed on hundreds of leukocytes from slides previously stained to demonstrate any one of a variety of reactions. These included cellular glycogen, lipids, peroxidase, esterases, alkaline phosphatase, and acid phosphatase. In addition to these slide studies, chamber studies with an adapted Dvorak-Stotler Chamber allowed the measurement of enzyme kinetics within single cells.
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- 1978
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17. Group selections among laboratory populations of Tribolium.
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Wade, M J
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Selection at the population level or group selection is defined as genetic change that is brought about or maintained by the differential extinction and/or proliferation of populations. Group selection for both increased and decreased adult population size was carried out among laboratory populations of Tribolium castaneum at 37-day intervals. The effect of individual selection within populations on adult population size was evaluated in an additional control series of populations. The response in the group selection treatments occurred rapidly, within three or four generations, and was large in magnitude, at times differing from the controls by over 200%. This response to selection at the populational level occurred despite strong individual selection which caused a decline in the mean size of the control populations from over 200 adults to near 50 adults in nine 37-day intervals. "Assay" experiments indicated that selective changes in fecundity, developmental time, body weight, and cannibalism rates were responsible in part for the observed treatment differences in adult population size. These findings have implications in terms of speciation in organisms whose range is composed of many partially isolated local populations.
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- 1976
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18. Liquid Encapsulated Compounding and Czochralski Growth of Semi-Insulating Gallium Arsenide for Microwave/Millimeter-Wave Applications.
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ARMY ELECTRONICS RESEARCH AND DEVELOPMENT COMMAND FORT MONMOUTH NJ ELECTRONICS TECHNOLOGY/DEVICES LAB, AuCoin,T R, Ross,R L, Wade,M J, Savage,R O, ARMY ELECTRONICS RESEARCH AND DEVELOPMENT COMMAND FORT MONMOUTH NJ ELECTRONICS TECHNOLOGY/DEVICES LAB, AuCoin,T R, Ross,R L, Wade,M J, and Savage,R O
- Abstract
A wide variety of semiconductor devices utilizing gallium arsenide are currently under development by the military for use in secure communication, improved surveillance, and high speed digital logic systems. The GaAs field effect transistor, a critical component in these systems, is experiencing a rapidly expanding use in oscillator, mixer, logic element, power amplification, and low-noise/high-gain applications. However, the full potential of this device has not been realized, partly because of poor and unpredictable quality semi-insulating GaAs substrates. More specifically, native defects, electrically active impurities, and diffusing charge traps are problems associated with commercial substrates. A silicon- and carbon-free modification of the liquid encapsulated Czochralski technique is described which yields high purity semi-insulating GaAs (approximately 10 to the 8th ohm-cm) without the intentional addition of charge compensators. The technique employs liquid encapsulated compounding of GaAs at nitrogen pressures to 100 atm, ultrapure elements, and pyrolytic boron nitride crucibles. A high pressure (135 atm) Varian HPCZ Czochralski crystal puller is employed for both compounding and crystal growth. (Author)
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- 1979
19. High Efficiency Pentaphosphates for Miniaturized Laser Applications
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ARMY ELECTRONICS TECHNOLOGY AND DEVICES LAB FORT MONMOUTH N J, Schwartz,A., Wade,M. J., Aucoin,T. R., Gualtieri,J. G., ARMY ELECTRONICS TECHNOLOGY AND DEVICES LAB FORT MONMOUTH N J, Schwartz,A., Wade,M. J., Aucoin,T. R., and Gualtieri,J. G.
- Abstract
The requirement for low-threshold high-efficiency laser sources for miniaturized rangefinder and fiber optic communication applications has led to the study of rare earth pentaphosphate compounds. Neodymium pentaphosphate (NdPP) has recently emerged as a promising 1.05 micrometer laser material operating in pulsed and cw modes, with thresholds of the latter reported less than 1 milliwatt. In contrast to doped lasers such as Nd:YAG, NdPP is a stoichiometric compound (NdP5O14) which accommodates up to thirty times more Nd than YAG. The evaluation and testing of NdPP lasers in prototype components using transverse and longitudinal optical pumping has been hindered due to the limited size (several mm), availabilty, and quality of the single crystals. We have devised unique modifications of conventional solution growth techniques in order to control reaction kinetics and precipitation rates. The largest bulk single crystals (greater than 1 cm) of yttrium and lanthanum substituted NdPP presently available were grown by these modified techniques. We have observed laser action in as-grown 90% Nd 10% Y pentaphosphate crystals with dimensions typically 4.5x3 mm in diamond-shaped cross section by 2 mm thick.
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- 1976
20. Performance of Concrete Pavements Containing Recycled Concrete Aggregate
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United States. Federal Highway Administration. Office of Engineering and Highway Operations R&D, Forster, Steven, Wade, M. J., Cuttell, G.D., Vandenbossche, Julie M, Yu, H. T., Smith, K. D., Snyder, M. B., University of Minnesota, Duluth. Department of Civil Engineering, United States. Federal Highway Administration. Office of Engineering and Highway Operations R&D, Forster, Steven, Wade, M. J., Cuttell, G.D., Vandenbossche, Julie M, Yu, H. T., Smith, K. D., Snyder, M. B., and University of Minnesota, Duluth. Department of Civil Engineering
- Abstract
DTFH61-93-C-00133, This interim report documents the field performance of nine concrete pavement projects that incorporate recycled concrete aggregate (RCA) in the construction of the pavement. Multiple sections were evaluated on many of the nine projects, due to perceived differences in performance levels or variations in pavement design (such as the use of virgin aggregate or the inclusion of dowel bars). All told, a total of 17 sections (of which 12 contain RCA) were subjected to an extensive field testing program, consisting of pavement condition surveys, drainage surveys, falling weight deflectometer (FWD) testing, coring, and serviceability assessments. A minimum of eight cores were retrieved from each section for laboratory evaluation of compressive strength, split tensile strength, dynamic elastic modulus, static elastic modulus, and thermal coefficient of expansion, as well as for volumetric surface testing and petrographic analyses. Each of the 17 sections included in the investigation is described in detail. Performance observations and results from the FWD and laboratory testing are presented, with emphasis on evaluating the effect of RCA on pavement performance. An overall summary is provided that synthesizes the findings and conclusions of the field testing program. A laboratory-based research effort is currently being planned to provide additional insight on the behavior of concrete mixtures using RCA. Those laboratory-based results, taken in conjunction with the results of the field testing program, will be used to produce guidelines for the design of recycled concrete mixtures and to develop recommendations for the design of concrete pavements using RCA.
21. Guidelines for Detection, Analysis, and Treatment of Materials-Related Distress in Concrete Pavements – Volume 3: Case Studies Using the Guidelines
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United States. Federal Highway Administration. Office of Research, Development, and Technology, Turner-Fairbank Highway Research Center, Forster, Stephen W., Sutter, Lawrence L., Peterson, K. R., Van Dam, Thomas J., Smith, K. D., Wade, M. J., Michigan Technological University. Department of Civil and Environmental Engineering, United States. Federal Highway Administration. Office of Research, Development, and Technology, Turner-Fairbank Highway Research Center, Forster, Stephen W., Sutter, Lawrence L., Peterson, K. R., Van Dam, Thomas J., Smith, K. D., Wade, M. J., and Michigan Technological University. Department of Civil and Environmental Engineering
- Abstract
DTFH61-96-C-00073, The performance of concrete pavements can be adversely affected by the concrete's inability to resist the environment in which it is placed. This lack of durability can occur even when the structural design of the pavement is adequate. The distresses that result from this lack of durability are referred to herein as materials-related distress (MRD). This report documents the investigation of MRD in concrete pavements and the development of a set of systematic guidelines for the evaluation of MRD. The guidelines developed cover three major areas of MRD: field distress surveys, pavement sampling, and sample handling; laboratory testing, data analysis, and interpretation; and treatment, rehabilitation, and prevention.
22. Sexual Reproduction
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WADE, M. J., primary
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- 1982
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23. The ecology of sexual selection: mean crowding of females and resource-defence polygyny
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Wade, M. J.
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MATHEMATICAL analysis ,REPRODUCTION ,SEXUAL selection - Published
- 1995
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24. Perspectives in Mathematical Modelling for Microbial Ecology
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Tewfik Sari, Matthew J. Wade, Bertrand Cloez, Boumediene Benyahia, Boumédiène Moussa Boubjemaa, Claude Lobry, Jean-Jacques Godon, Stephane Chaillou, Jérôme Harmand, Théodore Bouchez, Roger Arditi, Alain Rapaport, School of Civil Engineering and Geosciences [Newcastle], Newcastle University [Newcastle], Laboratoire de Biotechnologie de l'Environnement [Narbonne] (LBE), Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Modelling and Optimisation of the Dynamics of Ecosystems with MICro-organisme (MODEMIC), Inria Sophia Antipolis - Méditerranée (CRISAM), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Mathématiques, Informatique et STatistique pour l'Environnement et l'Agronomie (MISTEA), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Laboratoire d'Automatique de Tlemcen (LAT), Université Aboubekr Belkaid - University of Belkaïd Abou Bekr [Tlemcen], Hydrosystèmes et Bioprocédés (UR HBAN), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), MICrobiologie de l'ALImentation au Service de la Santé (MICALIS), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Unité de recherche Flore Lactique et Environnement Carné (UFLEC), Institut National de la Recherche Agronomique (INRA), Mathématiques, Informatique et STatistique pour l'Environnement et l'Agronomie (MISTEA), Laboratoire de Microbiologie Appliquée à l'Agroalimentaire, au Biomédical et à l'Environnement (LAMAABE), Information – Technologies – Analyse Environnementale – Procédés Agricoles (UMR ITAP), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Department of Biology [Fribourg], University of Freiburg [Freiburg], CIB/EPFL, School of Civil Engineering & Geosciences [Newcastle], Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA), Hydrosystèmes et bioprocédés (UR HBAN), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Wade, M. J., and Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut National de la Recherche Agronomique (INRA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)
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0301 basic medicine ,[SDV.BIO]Life Sciences [q-bio]/Biotechnology ,Operations research ,MESH: chemostat ,outil moléculaire ,[MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS] ,MESH: density dependence ,Biology ,01 natural sciences ,perspective de développement ,MATHEMATICAL MODELLING ,Microbial ecology ,03 medical and health sciences ,modèle mathématique ,MESH: thermodynamics ,[SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems ,mathematical modelling ,microbial ecology ,chemostat ,density dependence ,thermodynamics ,MESH: mathematical modelling ,0101 mathematics ,thermodynamique ,densité dépendance ,DENSITY DEPENDENCE ,MESH: microbial ecology ,Pace ,écologie microbienne ,Mathematical model ,Management science ,[SDE.IE]Environmental Sciences/Environmental Engineering ,Ecological Modeling ,010102 general mathematics ,Maturity (finance) ,Ecological Modelling ,030104 developmental biology ,Chemostat ,[SDE]Environmental Sciences ,Industrial systems ,Thermodynamics ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology - Abstract
[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [TR2_IRSTEA]INSPIRE; International audience; Although mathematical modelling has reached a degree of maturity in the last decades, microbial ecology is still developing, albeit at a rapid pace thanks to new insights provided by modern molecular tools. However, whilst microbiologists have long enjoyed the perspectives that particular mathematical frameworks can provide, there remains a reluctance to fully embrace the potential of models, which appear too complex, esoteric or distant from the “real-world”. Nevertheless there is a strong case for pursuing the development of mathematical models to describe microbial behaviour and interactions, dynamically, spatially and across scales. Here we put forward perspectives on the current state of mathematical modelling in microbial ecology, looking back at the developments that have defined the synergies between the disciplines, and outline some of the existing challenges that motivate us to provide practical models in the hope that greater engagement with empiricists and practitioners in the microbiological domain may be achieved. We also indicate recent advances in modelling that have had impact in both the fundamental understanding of microbial ecology and its practical application in engineered biological systems. In this way, it is anticipated that interest can be garnered from across the microbiological spectrum resulting in a broader uptake of mathematical concepts in lecture theatres, laboratories and industrial systems.
- Published
- 2016
25. On indirect genetic effects in structured populations.
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Agrawal AF, Brodie ED 3rd, and Wade MJ
- Abstract
Indirect genetic effects (IGEs) occur when the phenotype of an individual, and possibly its fitness, depends, at least in part, on the genes of its social partners. The effective result is that environmental sources of phenotypic variance can themselves evolve. Simple models have shown that IGEs can alter the rate and direction of evolution for traits involved in interactions. Here we expand the applicability of the theory of IGEs to evolution in metapopulations by including nonlinear interactions between individuals and population genetic structure. Although population subdivision alone generates some dramatic and nonintuitive evolutionary dynamics for interacting phenotypes, the combination of nonlinear interactions with subdivision reveals an even greater importance of IGEs. The presence of genetic structure links the evolution of interacting phenotypes and the traits that influence their expression ("effector traits") even in the absence of genetic correlations. When nonlinear social effects occur in subdivided populations, evolutionary response is altered and can even oppose the direction expected due to direct selection. Because population genetic structure allows for multilevel selection, we also investigate the role of IGEs in determining the response to individual and group selection. We find that nonlinear social effects can cause interference between levels of selection even when they act in the same direction. In some cases, interference can be so extreme that the actual evolutionary response to multilevel selection is opposite in direction to that predicted by summing selection at each level. This theoretical result confirms empirical data that show higher levels of selection cannot be ignored even when selection acts in the same direction at all levels.
- Published
- 2001
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26. Cultural inheritance as a mechanism for population sex-ratio bias in reptiles.
- Author
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Freedberg S and Wade MJ
- Subjects
- Animals, Behavior, Animal, Biological Evolution, Female, Genetics, Population, Male, Models, Biological, Sex Determination Processes, Sex Ratio, Turtles genetics, Turtles physiology, Reptiles genetics, Reptiles physiology
- Abstract
Although natural populations of most species exhibit a 1:1 sex ratio, biased sex ratios are known to be associated with non-Mendelian inheritance, as in sex-linked meiotic drive and cytoplasmic inheritance (Charnov 1982; Hurst 1993). We show how cultural inheritance, another type of non-Mendelian inheritance, can favor skewed primary sex ratios and propose that it may explain the female-biased sex ratios commonly observed in reptiles with environmental sex determination (ESD). Like cytoplasmic elements, cultural traits can be inherited through one sex. This, in turn, favors skewing the primary sex allocation in favor of the transmitting sex. Female nest-site philopatry is a sex-specific, culturally inherited trait in many reptiles with ESD and highly female-biased sex ratios. We propose that the association of nest-site selection with ESD facilitates the maternal manipulation of offspring sex ratios toward females.
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- 2001
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27. Maternal effect genes and the evolution of sociality in haplo-diploid organisms.
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Wade MJ
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- Alleles, Animals, Biological Evolution, Diploidy, Female, Genetics, Population, Haploidy, Hymenoptera physiology, Male, Nuclear Family, Sex Ratio, Hymenoptera genetics, Models, Genetic, Mothers, Social Behavior
- Abstract
Maternal care and female-biased sex ratios are considered by many to be essential prerequisites for the evolution of eusocial behaviors among the hymenoptera. Using population genetic models, I investigate the evolution of genes that have positive maternal effects but negative, direct effects on offspring fitness. I find that, under many conditions, such genes evolve more easily in haplo-diploids than in diplo-diploids. In fact, the conditions are less restrictive than those of kin selection theory, which postulate genes with negative direct effects but positive sib-social effects. For example, the conditions permitting the evolution of maternal effect genes are not affected if females mate multiply, whereas multiple mating reduces the efficacy of kin selection by reducing genetic relatedness within colonies. Inbreeding also differentially facilitates evolution of maternal effect genes in haplo-diploids relative to diplo-diploids, although it does not differentially affect the evolution of sib-altruism genes. Furthermore, when the direct, deleterious pleiotropic effect is restricted to sons, a maternal effect gene can evolve when the beneficial maternal effect is less than half (with inbreeding, much less) of the deleterious effect on sons. For kin selection, however, the sib-social benefits must always exceed the direct costs because genetic relatedness is always less than or equal to 1.0. The results suggest that haplo-diploidy facilitates (1) the evolution of maternal care, and (2) the evolution of maternal effect genes with antagonistic pleiotropic effects on sons. The latter effect may help explain the tendency toward female-biased sex ratios in haplo-diploids, especially those with inbreeding. I conclude that haplo-diploidy not only facilitates the evolution of sister-sister altruism by kin selection but also facilitates the evolution of maternal care and female-biased sex ratios, two prerequisites for eusociality.
- Published
- 2001
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28. Infectious speciation.
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Wade MJ
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- Animals, Cytoplasm, Female, Host-Parasite Interactions, Male, Reproduction, Wasps genetics, Biological Evolution, Wasps parasitology, Wolbachia physiology
- Published
- 2001
- Full Text
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29. Epistasis, complex traits, and mapping genes.
- Author
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Wade MJ
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- Alleles, Biological Evolution, Genetic Variation, Models, Genetic, Chromosome Mapping, Epistasis, Genetic, Multifactorial Inheritance
- Abstract
Using a three-locus model wherein two loci regulate a third, candidate locus, I examine physiological epistasis from the 'gene's eye view' of the regulated locus. I show that, depending upon genetic background at the regulatory loci, an allele at the candidate locus can be dominant, additive, recessive, neutral, over-dominant, or under-dominant in its effects on fitness. This kind of variation in allelic effect caused by variation in genetic background from population to population, from time to time in the same population, or sample to sample makes finding and mapping the genes underlying a complex phenotype difficult. The rate of evolution of such genes can also be slowed, especially in genetically subdivided metapopulations with migration. Nevertheless, understanding how variation in genetic background causes variation in allelic effects permits the genetic architecture of such complex traits to be dissected into the interacting component genes. While some backgrounds diminish allelic effects and make finding and mapping genes difficult, other backgrounds enhance allelic effects and facilitate gene mapping.
- Published
- 2001
30. Early invasive versus ischaemia-guided strategies in the management of non-Q wave myocardial infarction patients with and without prior myocardial infarction; results of Veterans Affairs Non-Q Wave Infarction Strategies in Hospital (VANQWISH) trial.
- Author
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Heggunje PS, Wade MJ, O'Rourke RA, Kleiger RE, Deedwania PC, Lavori PW, and Boden WE
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- Aged, Female, Humans, Male, Middle Aged, Myocardial Infarction physiopathology, Proportional Hazards Models, Recurrence, Risk, Survival Analysis, Myocardial Infarction therapy, Myocardial Revascularization methods
- Abstract
Aims: To compare the role of early invasive vs conservative management strategies in treating patients with non-Q wave myocardial infarction with or without a prior myocardial infarction., Background: In patients recovering from non-Q wave myocardial infarction, the prognosis among patients with a first non-Q wave myocardial infarction is significantly better than in patients with a prior myocardial infarction, yet physicians often adopt an early invasive strategy to treat patients with a first non-Q wave myocardial infarction., Methods: Non-Q wave myocardial infarction patients enrolled in the VANQWISH trial with a history of prior myocardial infarction were compared to those with a first non-Q wave myocardial infarction, for the trial primary end-point of death or myocardial infarction at 1 and 12 months, as well as for the initial randomized treatment strategy., Results: Of the 920 non-Q wave myocardial infarction patients, 396 had a history of prior myocardial infarction and 524 did not. Patients with a history of prior myocardial infarction were older and had a higher incidence of multiple high-risk baseline characteristics than those with a first non-Q wave myocardial infarction. Compared to the group with a first myocardial infarction, the prior myocardial infarction group suffered more events at both 1 month (11% vs 6%, P=0.007) and at 12 months (29% vs 16%, P<0.001). This difference in outcome remained significant even after adjusting for confounding variables (P<0.0001 at 12 months). Among the non-Q wave myocardial infarction patients with a prior myocardial infarction, the frequency of death or recurrent myocardial infarction was similar in both invasive and conservative groups during the first year of follow-up. Among the first non-Q wave myocardial infarction group, those assigned to the conservative strategy had significantly fewer events (3% vs 9%, P=0.009 at 1 month; 12% vs 20%, P=0.016 at 12 months) and mortality (1% vs 5%, P=0.012 at one month; 5% vs 11%, P=0.009 at 12 months) than those assigned to early invasive strategy., Conclusion: A history of prior myocardial infarction identifies a moderately high-risk subset of non-Q wave myocardial infarction patients who display similar long-term outcomes regardless of the strategy assignment; however, patients with a first non-Q wave myocardial infarction may fare better with a conservative or ischaemia-guided approach during the first post infarction year., (Copyright 2000 The European Society of Cardiology.)
- Published
- 2000
- Full Text
- View/download PDF
31. The ongoing synthesis: a reply to Coyne, Barton, and Turelli.
- Author
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Goodnight CJ and Wade MJ
- Subjects
- Animals, Epistasis, Genetic, Female, Genetics, Population, Male, Selection, Genetic, Species Specificity, Biological Evolution, Models, Genetic
- Published
- 2000
- Full Text
- View/download PDF
32. Opposing levels of selection can cause neutrality: mating patterns and maternal-fetal interactions.
- Author
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Wade MJ
- Subjects
- Alleles, Animals, Consanguinity, Female, Genetics, Population, Humans, Male, Mice, Models, Genetic, Pregnancy, Maternal-Fetal Exchange genetics, Selection, Genetic, Sexual Behavior
- Abstract
A biallelic viability model based on human data for maternal-fetal interactions reported by Hedrick (1997) gives the interesting result of neutral stability at all gene frequencies. I show that there are two levels of selection, within and among families, acting in opposing directions in this model and that the neutral stability occurs when the two levels of selection exactly balance one another, as they do in a randomly mating population. Deviations from random mating disrupt the balance and consequently destroy the neutral stability. However, with inbreeding avoidance, which characterizes the human histocompatibility loci, within-family selection is strengthened and among-family selection is weakened. This favors the invasion of new alleles and contributes to a high equilibrium level of genetic diversity at loci with maternal-fetal interactions affecting offspring viability in the pattern described by Hedrick. This pattern of selection is remarkably similar to that observed for the maternal effect selfish genes, Medea in flour beetles and scat in the mouse, and the Gp-9 gene in the fire ant.
- Published
- 2000
- Full Text
- View/download PDF
33. Populational heritability: empirical studies of evolution in metapopulations.
- Author
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Wade MJ and Griesemer JR
- Abstract
Using demes from experimental metapopulations of the flour beetle, Tribolium castaneum, we investigated phase 3 of Wright's shifting balance process. Using parent demes of high, intermediate, and low mean fitness, we experimentally modeled migration of varying amounts from demes of high mean fitness into demes of lower mean fitness (like phase 3) as well as the reciprocal (the opposite of phase 3). In natural populations, some migration among demes occurs independently of deme fitness. In this case, demes of high mean fitness are likely to receive migrants from demes of lower mean fitness; these effects might limit the effectiveness of phase 3 but have not been studied experimentally. We estimated the populational heritability of mean fitness by the regression of offspring deme means on the weighted parental means and found moderate levels of demic heritability one (0.641-0.690) and two (0.518-0.552) generations after migration. We discuss our findings in relation to the role of interdemic migration in "adaptive peak shifts" in metapopulations and the controversies over group selection and the units of inheritance.
- Published
- 1998
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- View/download PDF
34. Genetic variation segregating in natural populations of Tribolium castaneum affecting traits observed in hybrids with T. freemani.
- Author
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Wade MJ, Johnson NA, Jones R, Siguel V, and McNaughton M
- Subjects
- Animals, Female, Male, Sexual Behavior, Animal, Genetic Variation, Hybridization, Genetic genetics, Tribolium genetics
- Abstract
We investigated patterns of within-species genetic variation for traits observed in hybrids (hybrid numbers, hybrid sex ratios, and hybrid male deformities) between two species of flour beetles, Tribolium castaneum and T. freemani. We found genetic variation segregating among four natural populations of T. castaneum as well as within these populations. For some hybrid traits, we observed as much variation among populations 750 km apart as between populations on different continents, suggesting genetic differentiation at a local scale. Within natural populations, the variation segregating among sires is greater than that found in an earlier study for an outbred laboratory population and comparable to that observed between inbred lines derived from the outbred stock by eight generations of brother-sister mating. When sires from T. castaneum are mated to conspecific and heterospecific females, we do not observe a significant correlation at the level of the family mean between the intraspecific and interspecific phenotypes, suggesting the independence of the hybrid traits from comparable traits within species. We discuss our findings in relation to the evolutionary genetics of speciation and the expression of epistatic genetic variance in interspecific crosses.
- Published
- 1997
- Full Text
- View/download PDF
35. Incipient speciation in the flour beetle, Tribolium confusum: premating isolation between natural populations.
- Author
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Wade MJ, Chang NW, and McNaughton M
- Subjects
- Animals, Copulation, Croatia, Crosses, Genetic, Female, Fertility genetics, Genetics, Population, Male, Nigeria, Sex Ratio, Sexual Behavior, Animal, Biological Evolution, Tribolium genetics
- Abstract
We report the existence of partial reproductive isolation between two natural populations of the flour beetle, Tribolium confusum, collected in Kaduna, Nigeria and Zagreb, Croatia. When a female from either population is paired with a single sympatric or allopatric male, she produces near normal numbers of semifertile offspring. However, when females are multiply mated with allopatric and sympatric males, the sympatric males sire the large majority of offspring. When measured in offspring numbers, the mean relative fitness of allopatric males is 0.425 with Nigerian females and 0.085 with Croatian females. Thus, the reproductive isolation is reciprocal but asymmetric. Behavioural observations indicate that only a fraction of mating attempts by allopatric males are successful because females do not become quiescent as often when mounted by allopatric males. The premating isolation is also reciprocal but asymmetric: Nigerian females are more accepting of allopatric males as mates than are Croatian females. The prezygotic behavioural isolation between these two populations is different from the postmating, prezygotic isolation observed between two other species in the genus, T. castaneum and T. freemani. Furthermore, the T. confusum interpopulation hybrids are fertile although they exhibit a weak female bias.
- Published
- 1995
- Full Text
- View/download PDF
36. Increased male fertility in Tribolium confusum beetles after infection with the intracellular parasite Wolbachia.
- Author
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Wade MJ and Chang NW
- Subjects
- Animals, Female, Male, Symbiosis, Tribolium genetics, Tribolium microbiology, Fertility, Rickettsiaceae physiology, Tribolium physiology
- Abstract
The cytoplasmically inherited microorganism Wolbachia pipientis behaves like a sexually selected trait in its host, the flour beetle Tribolium confusum, enhancing male fertility at the expense of female fecundity. Here we show that infected females have fewer offspring than uninfected females but infected males have a large fertility advantage over uninfected males within multiply-inseminated infected or uninfected females. The male fertility effect accelerates the spread of the Wolbachia through the host population and expands the initial opportunity for hitch-hiking of host nuclear genes. Sperm competition in a host, mediated by endosymbionts, has not been previously described.
- Published
- 1995
- Full Text
- View/download PDF
37. Postcopulatory, prezygotic isolation: intraspecific and interspecific sperm precedence in Tribolium spp., flour beetles.
- Author
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Robinson T, Johnson NA, and Wade MJ
- Subjects
- Animals, Biological Evolution, Female, Genitalia, Female anatomy & histology, Male, Species Specificity, Tribolium genetics, Selection, Genetic, Sexual Behavior, Animal physiology, Spermatozoa physiology, Tribolium physiology
- Abstract
We investigated intraspecific and interspecific patterns of paternity in Tribolium castaneum, the flour beetle, by mating females either to pairs of conspecific males or to one conspecific and one heterospecific male of the closely related species, T. freemani. Females of both species store sperm in the spermatheca after copulation and postcopulatory, prezygotic reproductive isolation has been reported between this pair of species. When conspecific males of contrasting genotype are mated simultaneously to T. castaneum females, we observed extremely high levels of variation among females in the pattern of sperm precedence as shown by the offspring genotypes. In contrast, T. castaneum females mated simultaneously to a conspecific and a heterospecific male produced over 99 per cent conspecific progeny. When conspecific males were mated sequentially to T. castaneum females, within 3-7 days, all offspring were sired by the second male. In contrast, when a conspecific male was replaced with a T. freemani male, most females continued to produce only first-male, conspecific offspring for the next 10 days. When a heterospecific male was replaced with a conspecific male, T. castaneum females changed from producing hybrid to conspecific offspring within 3 days. We discuss the evolutionary implications of these findings.
- Published
- 1994
- Full Text
- View/download PDF
38. Reproductive isolation between two species of flour beetles, Tribolium castaneum and T. freemani: variation within and among geographical populations of T. castaneum.
- Author
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Wade MJ and Johnson NA
- Subjects
- Animals, Body Constitution, Coleoptera physiology, Crosses, Genetic, Female, Male, Reproduction physiology, Sex Ratio, Species Specificity, Coleoptera genetics, Genetic Variation, Hybridization, Genetic physiology
- Abstract
Tribolium castaneum and T. freemani produce sterile hybrid progeny in reciprocal crosses. The reciprocal crosses differ significantly in the mean numbers of progeny, progeny sex ratios, hybrid male body size and male antennal and leg morphologies. These results suggest an effect of either the X chromosome or the cytoplasm on characteristics of F1 hybrids. In contrast, large X chromosome effects on morphological traits are not usually observed in interspecific crosses among drosophilid flies. We also report large, significant differences in progeny numbers, body mass and degree of female bias in sex ratio between different geographic strains of T. castaneum when mated in reciprocal crosses with T. freemani. Sex ratio bias also varies significantly among matings within geographic strains of T. castaneum. When T. castaneum males are mated with T. freemani females, but not in the reciprocal cross, the F1 sex ratio is female biased, uncorrelated with family size and ranges from 57.14 per cent to 72.23 per cent female, depending on the geographic strain of the T. castaneum male.
- Published
- 1994
- Full Text
- View/download PDF
39. Postcopulatory, prezygotic isolation in flour beetles.
- Author
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Wade MJ, Patterson H, Chang NW, and Johnson NA
- Subjects
- Animals, Coleoptera embryology, Female, Male, Species Specificity, Zygote, Coleoptera physiology, Hybridization, Genetic physiology, Sexual Behavior, Animal
- Abstract
We report the existence of postmating but prezygotic reproductive isolation within flour beetles of the genus Tribolium. Specifically, when a female of either T. castaneum or T. freemani is paired simultaneously with both a conspecific and a heterospecific male, virtually all of the offspring are sired by the conspecific male. In contrast, when a female of either species is paired only with a heterospecific male, she produces near normal numbers of offspring. Mate choice experiments rule out the possibility that premating reproductive isolation accounts for this phenomenon. A number of different mechanisms could explain this phenomenon of postmating but prezygotic reproductive isolation.
- Published
- 1994
- Full Text
- View/download PDF
40. Wright's shifting balance theory: an experimental study.
- Author
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Wade MJ and Goodnight CJ
- Subjects
- Adaptation, Physiological, Animals, Coleoptera genetics, Gene Frequency, Genetic Variation, Selection, Genetic, Biological Evolution, Models, Genetic
- Abstract
Experimental confirmation of Wright's shifting balance theory of evolution, one of the most comprehensive theories of adaptive evolution, is presented. The theory is regarded by many as a cornerstone of modern evolutionary thought, but there has been little direct empirical evidence supporting it. Some of its underlying assumptions are viewed as contradictory, and the existence and efficacy of the theory's fundamental adaptive process, interdemic selection, is the focus of controversy. Interdemic selection was imposed on large arrays of laboratory populations of the flour beetle Tribolium castaneum in the manner described by Wright: the differential dispersion of individuals from demes of high fitness into demes of low fitness. A significant increase in average fitness was observed in the experimental arrays when compared to control populations with equivalent but random migration rates. The response was not proportional to the selection differential: The largest response occurred with interdemic selection every two generations rather than every generation or every three generations. The results indicate that the interdemic phase of Wright's shifting balance theory can increase average fitness and suggest that gene interactions are involved in the observed response.
- Published
- 1991
- Full Text
- View/download PDF
41. Kin selection: A classical approach and a general solution.
- Author
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Wade MJ
- Abstract
The necessary conditions for the spread of genes that determine social behaviors and the rate of spread of these genes are derived for a simple model (single locus, two alleles, random mating, discrete generations) by using the classical population genetics approach pioneered by Haldane and the linear fitness function used previously by D. S. Wilson. These results are derived for social behaviors that are manifested by individuals within families, within pairs of families, or within groups of k families, for both diploid and haplodiploid organisms. I show that, when the groups of socially interacting individuals consist of the members of more than one family, severe restrictions are placed on the evolution of altruistic and social behaviors. Specifically, in these instances, the necessary conditions for the evolution of social behaviors are more stringent and the rate of evolution is greatly reduced.
- Published
- 1978
- Full Text
- View/download PDF
42. Behavioral evolution: evolutionary genetics of invertebrate behavior.
- Author
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Wade MJ
- Published
- 1987
- Full Text
- View/download PDF
43. Kin selection: its components.
- Author
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Wade MJ
- Abstract
Change in gene frequency under kin selection is the sum of two components, namely, [See equation in the PDF file], a change in gene frequency caused by individual selection, and [See equation in the PDF file], a change caused by group selection. For the evolution of altruistic traits by kin selection, [See equation in the PDF file] is always negative-that is, individual selection operates against altruism-and [See equation in the PDF file] is always positive, so that selection between groups favors altruism. Hamilton's rule specifies the conditions under which [See equation in the PDF file]-that is, the conditions necessary for intergroup selection to override individual selection.
- Published
- 1980
- Full Text
- View/download PDF
44. Wright's View of Evolution.
- Author
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Wade MJ
- Published
- 1980
- Full Text
- View/download PDF
45. Geographic and genetic variation in death-feigning behavior in the flour beetle, Tribolium castaneum.
- Author
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Prohammer LA and Wade MJ
- Subjects
- Animals, Behavior, Animal, Conditioning, Classical, Female, Genetics, Behavioral, Male, Time Factors, Genetic Variation, Tribolium genetics
- Abstract
Five recently collected wild strains of the flour beetle, Tribolium castaneum, from Spain, Japan, and the United States were tested for phenotypic differences in the proclivity toward death feigning and in the duration of feints. Subsequently, the genetic basis for the observed geographic differences was established by within-strain and between-strain reciprocal crosses of the two most divergent strains. The results indicate that simple additive genetic factors are involved in the transmission of this behavior, with no detectable differences between sexes or evidence of maternal effects.
- Published
- 1981
- Full Text
- View/download PDF
46. High resolution shading correction.
- Author
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Schultz ML, Lipkin LE, Wade MJ, Lemkin PF, and Carman GM
- Subjects
- Autoanalysis, Computers, Computers, Analog, Diagnosis, Computer-Assisted, Evaluation Studies as Topic, Histocytochemistry, Lighting, Mass Screening, Methods, Staining and Labeling, Time Factors, Cells cytology
- Published
- 1974
- Full Text
- View/download PDF
47. Evolution of interference competition by individual, family, and group selection.
- Author
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Wade MJ
- Abstract
The necessary conditions for the evolution of social behaviors in a population with three levels of biological organization are derived by using a population genetic model (one locus, two alleles, random mating, discrete generations). Total selection on the behavior, Deltaq, is partitioned into the sum of three components: (i) Deltaq(I), selection between individuals within families; (ii) Deltaq(F), selection between families within groups; and (iii) Deltaq(G), selection between groups of families. I show that any level of selection can be made to operate in concert with or in opposition to any other, depending upon the fitness effects of the behavior. The implications of the model are discussed in relation to those adaptive explanations of phenotypic traits that generally consider selection to operate only between individuals.
- Published
- 1982
- Full Text
- View/download PDF
48. Microorganism mediated reproductive isolation in flour beetles (genus Tribolium).
- Author
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Wade MJ and Stevens L
- Subjects
- Animals, Crosses, Genetic, Female, Male, Reproduction, Tetracycline pharmacology, Tribolium drug effects, Tribolium microbiology, Bacterial Physiological Phenomena, Tribolium physiology
- Abstract
Reproductive isolation is induced by microorganisms in diverse geographic strains of the flour beetle Tribolium confusum (Coleoptera:Tenebrionidae). The incompatibility between populations is due to nongenetic cytoplasmically inherited factors. Males of infected strains produce no progeny when crossed with females of noninfected strains; however, they produce "normal" numbers of progeny when crossed with infected females. Males from noninfected strains show no reproductive isolation. Infected strains of T. confusum can be cured when tetracycline or other antibiotics are added to the flour medium. "Cured" strains become partially reproductively isolated from all noncured strains including the source strain
- Published
- 1985
- Full Text
- View/download PDF
49. Asbestos cytotoxicity in a long term macrophage-like cell culture.
- Author
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Wade MJ, Lipkin LE, Tucker RW, and Frank AL
- Subjects
- Asbestos metabolism, Cell Line, Cell Survival drug effects, Dose-Response Relationship, Drug, Macrophages physiology, Phagocytosis, Asbestos toxicity, Macrophages drug effects
- Published
- 1976
- Full Text
- View/download PDF
50. Apparatus to record bowel sounds and intestinal pressures.
- Author
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Garclay GA, Solman AJ, and Wade MJ
- Subjects
- Auscultation, Humans, Tape Recording, Intestines physiology
- Published
- 1967
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