Estrategias para el mejoramiento de bananos y plátanos.

La producción de cultivares mejorados por cualquier método es un proceso que se basa en los principios de variación genética, selección y evaluación. Con el método tradicional estas etapas han sido en extremo laboriosas y lentas, además, poco han sido los resultados obtenidos que permitan ofrecer nuevas variedades al productor. Hoy en día la biotecnología ofrece varias alternativas, que se mencionan a través del artículo, para ampliar la variación genética y obtener en corto tiempo nuevas líneas para seleccionar y evaluar. Los avances biotecnológicos logrados en los últimos veinte años, se han alcanzado con el desarrollo de los sistemas in vitro y la ingeniería genéticaBanano- Musa acuminata - Musa paradisiacaPlátano-Musa sapientu

Self-tuning to the Hopf bifurcation in fluctuating systems

The problem of self-tuning a system to the Hopf bifurcation in the presence of noise and periodic external forcing is discussed. We find that the response of the system has a non-monotonic dependence on the noise-strength, and displays an amplified response which is more pronounced for weaker signals. The observed effect is to be distinguished from stochastic resonance. For the feedback we have studied, the unforced self-tuned Hopf oscillator in the presence of fluctuations exhibits sharp peaks in its spectrum. The implications of our general results are briefly discussed in the context of sound detection by the inner ear.Comment: 37 pages, 7 figures (8 figure files

SAFE, a new therapeutic intervention for families of children with autism: study protocol for a feasibility randomised controlled trial

IntroductionIncidence of autistic traits, mental health problems, stress and poor coping is high among family members of children with autism. These problems are coupled with challenging behaviour among children with autism. Current treatment for these families is disjointed and costly. The need for whole family support is supported by the National Institute for Health and Care Excellence recommendations, developments regarding children’s service provision, research and requests by families of children with autism. Despite evidence that family therapies can provide benefits to these families, efficacy has not been subject to a randomised controlled trial. Systemic Autism-related Family Enabling (SAFE) is a new family therapy intervention designed specifically for families of children with autism. We aim to establish the feasibility of running a fully powered randomised controlled trial to evaluate SAFE.Methods and analysisFamilies of children with autism aged 3–16 years will be invited to participate. Consenting participants will be randomised 2:1 to either SAFE+support as usual or support as usual alone. The proposed primary outcome measure for the main trial will be the Systemic CORE 15. Participants will also complete proposed secondary outcome measures, indexing changes in child behaviour, child-parent attachment, anxiety and depression. Generic health economic outcome measures (EuroQol 5 dimensions and Child Health Utility 9 Dimensions) will also provide data on the feasibility of cost-effectiveness analysis. Questionnaires will be completed at baseline and 32 weeks post-allocation. Data on ability to identify, recruit, randomise, retain and collect data from families, acceptability of outcome measures, adherence of therapists and families to the intervention, appropriateness of resource use questionnaires and effectiveness of training will be collected for feasibility analysis. Qualitative data will also explore acceptability of SAFE and reasons for declining and withdrawing from the study.Ethics and disseminationThe current trial protocol received ethical approval from the South West-Exeter Research Ethics Committee (Ref: 17/SW/0192). The findings of the trial will be disseminated in collaboration with our Family Consultation Group and other partners. Findings will be shared locally, nationally and internationally through events, conferences and published papers.Trial registration numberISCTRN83964946 (Pre-results) IRAS 213527</jats:sec

A model and experimental approach to the middle ear transfer function related to hearing in the humpback whale (Megaptera novaeangliae)

At present, there are no direct measures of hearing for any baleen whale (Mysticeti). The most viable alternative to in vivo approaches to simulate the audiogram is through modeling outer, middle, and inner ear functions based on the anatomy and material properties of each component. This paper describes a finite element model of the middle ear for the humpback whale (Megaptera novaeangliae) to calculate the middle ear transfer function (METF) to determine acoustic energy transmission to the cochlea. The model was developed based on high resolution computed tomography imaging and direct anatomical measurements of the middle ear components for this mysticete species. Mechanical properties for the middle ear tissues were determined from experimental measurements and published values. The METF for the humpback whale predicted a better frequency range between approximately 15 Hz and 3 kHz or between 200 Hz and 9 kHz based on two potential stimulation locations. Experimental measures of the ossicular chain, tympanic membrane, and tympanic bone velocities showed frequency response characteristics consistent with the model. The predicted best sensitivity hearing ranges match well with known vocalizations of this species

The transition into adoptive parenthood: adoption as a process of continued unsafe uncertainty when family scripts collide

Our prospective study investigated couples’ expectations of adoptive parenthood and explored how these changed with their actual experience of parenthood. Six heterosexual couples were interviewed just before placement began and six months after the children had arrived. Interpretative Phenomenological Analysis (IPA) was used to analyse both sets of interview data. Expectations of adoptive parenthood mostly transformed smoothly into adoption experience for couples but challenges were experienced when family scripts collided and a continued feeling of unsafe uncertainty then prevailed within these newly formed family systems. Family script collision seemed a particular problem for couples adopting sibling pairs. To further professional practice in working with families over the transition to adoptive parenting we suggest that professionals keep in mind a framework that includes: Internal and external world influences on family members, Intergenerational issues, Family scripts, and the Structural challenges of adoption (IIFS)

Illusory Percepts from Auditory Adaptation

Phenomena resembling tinnitus and Zwicker phantom tone are seen to result from an auditory gain adaptation mechanism that attempts to make full use of a fixed-capacity channel. In the case of tinnitus, the gain adaptation enhances internal noise of a frequency band otherwise silent due to damage. This generates a percept of a phantom sound as a consequence of hearing loss. In the case of Zwicker tone, a frequency band is temporarily silent during the presentation of a notched broad-band sound, resulting in a percept of a tone at the notched frequency. The model suggests a link between tinnitus and the Zwicker tone percept, in that it predicts different results for normal and tinnitus subjects due to a loss of instantaneous nonlinear compression. Listening experiments on 44 subjects show that tinnitus subjects (11 of 44) are significantly more likely to hear the Zwicker tone. This psychoacoustic experiment establishes the first empirical link between the Zwicker tone percept and tinnitus. Together with the modeling results, this supports the hypothesis that the phantom percept is a consequence of a central adaptation mechanism confronted with a degraded sensory apparatus

Ansiedad dimensional: Un análisis desde la teoría clásica del formulario autodiligenciado de Zung

RESUMEN Introducción: A pesar del uso extendido del formulario de Zung para ansiedad no se encontraron artículos sobre la invarianza de la prueba. Objetivo: Establecer la invarianza por género del formulario para ansiedad autodiligenciado de Zung desde la Teoría Clásica. Métodos: Muestra no aleaotoria de 336 mujeres y 205 hombres estudiantes de varias universidades colombianas que diligenciaron el formulario. El análisis se realizo con análisis confimatorio de factores. Se investigó la invarianza dimensional, de configuración y métrica. Resultados: Se encontró que las invarianzas dimensional y de configuración se cumplen al demostrarse que el constructo es unidimensional en los 2 géneros, seleccionando los modelos con el Criterio de información Bayesiano y que la carga de los ítems es en general alta. No así la invarianza métrica para la cual debieron eliminarse 9 ítems para lograr invarianza en las cargas. Conclusión: El formulario de Zung presenta invarianzas dimensional, de configuración y métrica con 11 ítems. Salud UIS 2011; 43 (2): 159-166 Palabras clave: Formulario autodiligenciado de Zung, invarianza, análisis de factores   ABSTRACT Introduction: There is not a published report of the invariance of anxiety Zung test, although is widely used. Objective: To stablish gender invariance of the Zung self-rating anxiety scale using Classical Test Theory. Methods: A non random sample of 336 women and 205 men students from several colombian universities that answered the scale. Confirmatory factor analysis was performed. Dimensional, configurational and metric invariance were investigated. Results: Dimensional and configurational invariance are met because for both genders theres is one dimension, using Bayesian Information Crietria as the model selection strategy, and the loadings are generally high. The metric invariance was obtained after deleting 9 items. Conclusion: Eleven items of The Zung self-rating anxiety scale show dimensional, configurational and metric invariance. Salud UIS 2011; 43 (2): 159-166 Keywords: The Zung self-rating scale, invariance, factor analysi

Ansiedad dimensional: Un análisis desde la teoría clásica del formulario autodiligenciado de Zung

RESUMEN Introducción: A pesar del uso extendido del formulario de Zung para ansiedad no se encontraron artículos sobre la invarianza de la prueba. Objetivo: Establecer la invarianza por género del formulario para ansiedad autodiligenciado de Zung desde la Teoría Clásica. Métodos: Muestra no aleaotoria de 336 mujeres y 205 hombres estudiantes de varias universidades colombianas que diligenciaron el formulario. El análisis se realizo con análisis confimatorio de factores. Se investigó la invarianza dimensional, de configuración y métrica. Resultados: Se encontró que las invarianzas dimensional y de configuración se cumplen al demostrarse que el constructo es unidimensional en los 2 géneros, seleccionando los modelos con el Criterio de información Bayesiano y que la carga de los ítems es en general alta. No así la invarianza métrica para la cual debieron eliminarse 9 ítems para lograr invarianza en las cargas. Conclusión: El formulario de Zung presenta invarianzas dimensional, de configuración y métrica con 11 ítems. Salud UIS 2011; 43 (2): 159-166 Palabras clave: Formulario autodiligenciado de Zung, invarianza, análisis de factores   ABSTRACT Introduction: There is not a published report of the invariance of anxiety Zung test, although is widely used. Objective: To stablish gender invariance of the Zung self-rating anxiety scale using Classical Test Theory. Methods: A non random sample of 336 women and 205 men students from several colombian universities that answered the scale. Confirmatory factor analysis was performed. Dimensional, configurational and metric invariance were investigated. Results: Dimensional and configurational invariance are met because for both genders theres is one dimension, using Bayesian Information Crietria as the model selection strategy, and the loadings are generally high. The metric invariance was obtained after deleting 9 items. Conclusion: Eleven items of The Zung self-rating anxiety scale show dimensional, configurational and metric invariance. Salud UIS 2011; 43 (2): 159-166 Keywords: The Zung self-rating scale, invariance, factor analysi

SAFE, a new therapeutic intervention for families of children with autism: a randomised controlled feasibility trial

ObjectivesTo establish the feasibility of a definitive randomised controlled trial of Systemic Autism-related Family Enabling (SAFE), an intervention for families of children with autism.DesignA randomised, controlled, multicentred feasibility study.SettingParticipants were identified from three National Health Service (NHS) diagnosing centres in Plymouth and Cornwall and a community pathway.Participants34 families of a child with a diagnosis of autism severity level 1 or 2 between 3 and 16 years. Four families were lost to follow-up.InterventionsSAFE is a manualised five-session family therapy-based intervention delivered over 16 weeks and designed for families of children with autism. SAFE involves families attending five 3-hour sessions led by systemic practitioners.Primary and secondary outcome measuresThe proposed primary outcome measure was the Systemic CORE 15 (SCORE-15). Proposed secondary outcome measures: Patient Health Questionnaire-Somatic Anxiety Depressive Symptoms, the Coding of Attachment-Related Parenting for use with children with Autism, the Child Behaviour Checklist (CBCL), the Reflective Functioning Questionnaire (RFQ) and the Caregiving Helplessness Questionnaire. Outcome measures were collected at baseline and 24 weeks post randomisation.ResultsAll primary caregivers retained in the study completed the SCORE-15 at both time points. 34 of the target of 36 families were recruited and 88% of families were retained. Training for therapists was effective. Feedback revealed willingness to undergo randomisation. There was 100% attendance at appropriate sessions for core family members. The SCORE-15 showed reduction in scores for families receiving SAFE compared with controls suggesting positive change. Qualitative data also revealed that families found the study acceptable and families receiving SAFE experienced positive change. Feedback indicated that the SCORE-15 should be retained as a primary measure in a future trial, but secondary measures should be reduced.ConclusionsThis study indicates that a larger trial of SAFE is feasible. Findings suggest that SAFE can address current gaps in recommended care, can be confidently delivered by NHS staff and has potential as a beneficial treatment.Trial registration numbersISCTRN83964946 and IRAS213527.</jats:sec