448 research outputs found
Cuando el desarrollo importa: de la psicologÃa evolucionista a la
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 artÃculo presenta la psicologÃa evolucionista del desarrollo (PED) como una perspectiva que emerge de la psicologÃa evolucionista (PE). Al describir las asunciones principales de ambos enfoques, asà 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 deberÃan prestar más atención a las cuestiones evolucionistas y, a la inversa, los psicólogos evolucionistas deberÃan tomar el desarrollo en serio. Palabras clave: psicologÃa evolucionista del desarrollo, psicologÃa evolucionista, psicologÃa del desarrollo, teorÃa de la evolución
Quantum-limited force measurement with an optomechanical device
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
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
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
Inhibition of tumor necrosis factor-alpha improves physiological angiogenesis and reduces pathological neovascularization in ischemic retinopathy
Origin and distribution of epipolythiodioxopiperazine (ETP) gene clusters in filamentous ascomycetes
<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
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
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
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
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