RESUMEN
Human altruism is often expressed through charitable donation-supporting a cause that benefits others in society, at cost to oneself. The underlying mechanisms of this other-regarding behavior remain imperfectly understood. By recording event-related-potential (ERP) measures of brain activity from human participants during a social gambling task, we identified markers of differential responses to receipt of monetary outcomes for oneself vs for a charitable cause. We focused our ERP analyses on the frontocentral feedback-related negativity (FRN) and three subcomponents of the attention-related P300 (P3) brain wave: the frontocentral P2 and P3a and the parietal P3b. The FRN distinguished between gains and losses for both self and charity outcomes. Importantly, this effect of outcome valence was greater for self than charity for both groups and was independent of two altruism-related measures: participants' pre-declared intended donations and the actual donations resulting from their choices. In contrast, differences in P3 subcomponents for outcomes for self vs charity strongly predicted both of our laboratory measures of altruism-as well as self-reported engagement in real-life altruistic behaviors. These results indicate that individual differences in altruism are linked to individual differences in the relative deployment of attention (as indexed by the P3) toward outcomes affecting other people.
Asunto(s)
Altruismo , Ondas Encefálicas/fisiología , Potenciales Evocados/fisiología , Recompensa , Adolescente , Adulto , Potenciales Relacionados con Evento P300/fisiología , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
The gradient of Bicoid (Bcd) is key for the establishment of the anterior-posterior axis in Drosophila embryos. The gradient properties are compatible with the SDD model in which Bcd is synthesized at the anterior pole and then diffuses into the embryo and is degraded with a characteristic time. Within this model, the Bcd diffusion coefficient is critical to set the timescale of gradient formation. This coefficient has been measured using two optical techniques, Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Correlation Spectroscopy (FCS), obtaining estimates in which the FCS value is an order of magnitude larger than the FRAP one. This discrepancy raises the following questions: which estimate is "correct''; what is the reason for the disparity; and can the SDD model explain Bcd gradient formation within the experimentally observed times? In this paper, we use a simple biophysical model in which Bcd diffuses and interacts with binding sites to show that both the FRAP and the FCS estimates may be correct and compatible with the observed timescale of gradient formation. The discrepancy arises from the fact that FCS and FRAP report on different effective (concentration dependent) diffusion coefficients, one of which describes the spreading rate of the individual Bcd molecules (the messengers) and the other one that of their concentration (the message). The latter is the one that is more relevant for the gradient establishment and is compatible with its formation within the experimentally observed times.
Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriología , Drosophila melanogaster/metabolismo , Proteínas de Homeodominio/metabolismo , Transactivadores/metabolismo , Transporte Activo de Núcleo Celular , Animales , Animales Modificados Genéticamente , Fenómenos Biofísicos , Tipificación del Cuerpo , Biología Computacional , Simulación por Computador , Difusión , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Recuperación de Fluorescencia tras Fotoblanqueo , Proteínas de Homeodominio/genética , Modelos Biológicos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Espectrometría de Fluorescencia , Transactivadores/genéticaRESUMEN
OBJECTIVE: To determine the prevalence of potential dosing errors of medication dispensed to children for 22 common medications. STUDY DESIGN: Using automated pharmacy data from 3 health maintenance organizations (HMOs), we randomly selected up to 120 children with a new dispensing prescription for each drug of interest, giving 1933 study subjects. Errors were defined as potential overdoses or potential underdoses. Error rate in 2 HMOs that use paper prescriptions was compared with 1 HMO that uses an electronic prescription writer. RESULTS: Approximately 15% of children were dispensed a medication with a potential dosing error: 8% were potential overdoses and 7% were potential underdoses. Among children weighing <35 kg, only 67% of doses were dispensed within recommended dosing ranges, and more than 1% were dispensed at more than twice the recommended maximum dose. Analgesics were most likely to be potentially overdosed (15%), whereas antiepileptics were most likely potentially underdosed (20%). Potential error rates were not lower at the site with an electronic prescription writer. CONCLUSIONS: Potential medication dosing errors occur frequently in outpatient pediatrics. Studies on the clinical impact of these potential errors and effective error prevention strategies are needed.
Asunto(s)
Atención Ambulatoria/normas , Prescripciones de Medicamentos , Errores de Medicación/estadística & datos numéricos , Pediatría/normas , Adolescente , Niño , Preescolar , Femenino , Sistemas Prepagos de Salud , Humanos , Lactante , Recién Nacido , Modelos Logísticos , Masculino , Errores de Medicación/prevención & control , Sistemas de Medicación , Estudios Retrospectivos , Factores de Riesgo , Estados UnidosRESUMEN
In the Xenopus laevis oocyte, calcium ion channels are clustered in a thin shell. Motivated by this morphology, we study a general class of reaction-diffusion systems that include most of the well-known models that support wave propagation but restricting excitability to a "sheet" of codimension 1. We find waves that undergo propagation failure with increasing diffusion coefficient and a scaling regime in which the wave speed is independent of it.