448 research outputs found

    Cuando el desarrollo importa: de la psicología evolucionista a la

    Get PDF
    This article presents evolutionary developmental psychology (EDP) as an emerging field of evolutionary psychology (EP). In describing the core tenets of both approaches and the differences between them, we emphasize the important roles that evolution and development have in understanding human behaviour. We suggest that developmental psychologists should pay more attention to evolutionary issues and, conversely, evolutionary psychologists should take development seriously. Key words: evolutionary developmental psychology, evolutionary psychology, developmental psychology, evolutionary theory.Este artículo presenta la psicología evolucionista del desarrollo (PED) como una perspectiva que emerge de la psicología evolucionista (PE). Al describir las asunciones principales de ambos enfoques, así como sus diferencias, se enfatiza la importancia que la evolución y el desarrollo tienen para la comprensión del comportamiento humano. Se sugiere que los psicólogos del desarrollo deberían prestar más atención a las cuestiones evolucionistas y, a la inversa, los psicólogos evolucionistas deberían tomar el desarrollo en serio. Palabras clave: psicología evolucionista del desarrollo, psicología evolucionista, psicología del desarrollo, teoría de la evolución

    Quantum-limited force measurement with an optomechanical device

    Full text link
    We study the detection of weak coherent forces by means of an optomechanical device formed by a highly reflecting isolated mirror shined by an intense and highly monochromatic laser field. Radiation pressure excites a vibrational mode of the mirror, inducing sidebands of the incident field, which are then measured by heterodyne detection. We determine the sensitivity of such a scheme and show that the use of an entangled input state of the two sideband modes improves the detection, even in the presence of damping and noise acting on the mechanical mode.Comment: 8 pages, 4 figure

    Population genetics in compressible flows

    Full text link
    We study competition between two biological species advected by a compressible velocity field. Individuals are treated as discrete Lagrangian particles that reproduce or die in a density-dependent fashion. In the absence of a velocity field and fitness advantage, number fluctuations lead to a coarsening dynamics typical of the stochastic Fisher equation. We then study three examples of compressible advecting fields: a shell model of turbulence, a sinusoidal velocity field and a linear velocity sink. In all cases, advection leads to a striking drop in the fixation time, as well as a large reduction in the global carrying capacity. Despite localization on convergence zones, one species goes extinct much more rapidly than in well-mixed populations. For a weak harmonic potential, one finds a bimodal distribution of fixation times. The long-lived states in this case are demixed configurations with a single boundary, whose location depends on the fitness advantage.Comment: 10 pages, 5 figures, submitte

    Defining Young in the Context of Prostate Cancer

    Get PDF
    The experience of prostate cancer is for most men a major life stress with the psychological burden of this disease falling more heavily on those who are younger. Despite this, being young as it applies to prostate cancer is not yet clearly defined with varied chronological approaches applied. However, men’s responses to health crises are closely bound to life course and masculinities from which social roles emerge. This paper applied qualitative methodology (structured focus groups and semistructured interviews with expert informants) using interpretative phenomenological analysis to define what it means to be young and have prostate cancer. Structured focus groups were held with 26 consumer advisors (men diagnosed with prostate cancer who provide support to other men with prostate cancer or raise community awareness) and health professionals. As well, 15 men diagnosed with prostate cancer and in their 40s, 50s, or 60s participated in semi-structured interviews. Participants discussed the attributes that describe a young man with prostate cancer and the experience of being young and diagnosed with prostate cancer. Chronological definitions of a young man were absent or inconsistent. Masculine constructions of what it means to be a young man and life course characteristics appear more relevant to defining young as it applies to prostate cancer compared with chronological age. These findings have implications for better understanding the morbidities associated with this illness, and in designing interventions that are oriented to life course and helping young men reconstruct their identities after prostate cancer

    Origin and distribution of epipolythiodioxopiperazine (ETP) gene clusters in filamentous ascomycetes

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Genes responsible for biosynthesis of fungal secondary metabolites are usually tightly clustered in the genome and co-regulated with metabolite production. Epipolythiodioxopiperazines (ETPs) are a class of secondary metabolite toxins produced by disparate ascomycete fungi and implicated in several animal and plant diseases. Gene clusters responsible for their production have previously been defined in only two fungi. Fungal genome sequence data have been surveyed for the presence of putative ETP clusters and cluster data have been generated from several fungal taxa where genome sequences are not available. Phylogenetic analysis of cluster genes has been used to investigate the assembly and heredity of these gene clusters.</p> <p>Results</p> <p>Putative ETP gene clusters are present in 14 ascomycete taxa, but absent in numerous other ascomycetes examined. These clusters are discontinuously distributed in ascomycete lineages. Gene content is not absolutely fixed, however, common genes are identified and phylogenies of six of these are separately inferred. In each phylogeny almost all cluster genes form monophyletic clades with non-cluster fungal paralogues being the nearest outgroups. This relatedness of cluster genes suggests that a progenitor ETP gene cluster assembled within an ancestral taxon. Within each of the cluster clades, the cluster genes group together in consistent subclades, however, these relationships do not always reflect the phylogeny of ascomycetes. Micro-synteny of several of the genes within the clusters provides further support for these subclades.</p> <p>Conclusion</p> <p>ETP gene clusters appear to have a single origin and have been inherited relatively intact rather than assembling independently in the different ascomycete lineages. This progenitor cluster has given rise to a small number of distinct phylogenetic classes of clusters that are represented in a discontinuous pattern throughout ascomycetes. The disjunct heredity of these clusters is discussed with consideration to multiple instances of independent cluster loss and lateral transfer of gene clusters between lineages.</p

    Optomechanical Cooling of a Macroscopic Oscillator by Homodyne Feedback

    Get PDF
    We propose a simple optomechanical model in which a mechanical oscillator quadrature could be "cooled" well below its equilibrium temperature by applying a suitable feedback to drive the orthogonal quadrature by means of the homodyne current of the radiation field used to probe its position.Comment: 9 pages, RevTeX, Figures available from authors, to appear in Phys. Rev. Let

    Motional Squashed States

    Full text link
    We show that by using a feedback loop it is possible to reduce the fluctuations in one quadrature of the vibrational degree of freedom of a trapped ion below the quantum limit. The stationary state is not a proper squeezed state, but rather a ``squashed'' state, since the uncertainty in the orthogonal quadrature, which is larger than the standard quantum limit, is unaffected by the feedback action.Comment: 8 pages, 2 figures, to appear in the special Issue "Quantum Correlations and Fluctuations" of J. Opt.

    Optomechanical scheme for the detection of weak impulsive forces

    Get PDF
    We show that a cooling scheme and an appropriate quantum nonstationary strategy can be used to improve the signal to noise ratio for the optomechanical detection of weak impulsive forces.Comment: 4 pages, Revtex, 1 figur
    • …
    corecore