Suchergebnisse

Escaping seed predation is a classic "economy of scale" hypotheses (predator satiation hypothesis, Psh) to explain the selection for the synchronous production of massive and nil seed crops (masting) in plants. The Psh postulates that predator satiation occurs through a combination of (1) "functional satiation," as not all seeds can be consumed during a massive crop, and (2) "numerical satiation," as predator populations collapse during poor crop years. Many studies advocate for the Psh, but few have investigated the importance of masting compared to other factors for the control of predation extent. Namely, environmental cues prompting masting could also determine predator's success and, ultimately, influence directly and independently seed predation intensity. We explored this question in Mediterranean oaks, as they exhibit strong masting behavior; acorns are heavily predated upon by weevils; and rainfall stochasticity drives masting and the emergence of adult weevils from the soil. Results of two mid-term studies (4 and 11 yr) showed that acorn production and predation were highly variable across years, while the abundance of adult weevils was positively related to autumn rainfall and to the number of infested acorns the previous years. Ultimately, acorn predation was negatively influenced by inter-annual fluctuation of seed production (masting) yet, mainly and positively, prompted by autumn rainfall and acorn crop size (only in one site). Our results highlight the relevance of masting to reduce seed predation. Yet evidences that rainfall stochasticity directly determines the success of weevils, and it independently influences seed predation extent, indicate that environmental cues prompting masting may also fine-tune the output of this reproductive behavior. Additionally, local differences suggest that the relevance of masting may change with tree characteristics (low vs. high seed production) and landscape structure (isolated vs. dense forests). We also discuss what can be the effects of increasing drought in Mediterranean areas for this antagonistic interaction, triggered by rainfall. ; This research was supported by the projects NOV-FORESTS (CGL2012-33398), FORASSEMBLY (CGL2015-70558-P), and PLAGANADO (AGL2014-54739-R) of the Ministerio de Economia y Competitividad (Spain), andthe projects BEEMED (SGR913) of the Generalitat de Catalunya and PII1C09-0256-9052 of the Regional Government of Castilla-La Mancha and the European Social Fund. R.B. was funded by a contract of the Pro-grama Atraccion de Talento Investigador del Gobierno de Extremadura. M.F.M. was funded by the Generalitat de Catalunya FI-2013 grants. ; Peer Reviewed

This work was funded by the European Union Seventh Framework programme (Full4Health - grant number 266408) and the Scottish Government Rural and Environment Science and Analytical Services Division to the Rowett Institute. Funders had no role in the preparation of data or the manuscript ; Peer reviewed ; Postprint

Acknowledgements This work was funded by the European Union Seventh Framework programme (Full4Health - grant number 266408) and the Scottish Government Rural and Environment Science and Analytical Services Division. We thank Danisco, Kettering, UK, for the gift of emulsifier. We thanks Dr Claus-Dieter Mayer of Biomathematics & Statistics Scotland for help with statistical analysis. ; Peer reviewed ; Postprint

Objectives: To study the characteristics of masturbation in children below the age of six years and to assess the course and outcome of this condition. Methods and Materials: A retrospective study of all children diagnosed to have masturbation at the pediatric clinic of Queen Alia Military Hospital over duration of three and half year's period. A data- collecting sheet was developed which includes information on demographic characteristics, clinical presentations, investigations and modes of treatment. Children with proven urinary tract infection, epilepsy and gastrointestinal disease were excluded from our study. Results: Fifteen children (6 males and 9 females) were found to have masturbation during the study period. The most common reason for presentation to the clinic was possible urinary tract infection (8=53.3%), abdominal pain (4=26.7%) and possible epileptic seizures (3=20%). The age at first symptom was variable with a mean of 18.5 months. The frequency of the masturbation act varied from 3 times per week to 10 times per day. Only one child had abnormal EEG, four children had extensive investigations. Only one child aged 10 months had home video recording. Twelve patients were treated with behavioral therapy alone. Three female children had in addition to behavioral therapy, local Zylocaine cream at the genital area. Conclusion: Masturbation is not uncommon in young children and should be included in the differential diagnosis of common pediatric instinct. Home video recording of events may prevent unnecessary investigations and treatments.

Degrowth is gaining traction as a viable alternative to mainstream approaches to sustainability. However, translating degrowth insights into concrete strategies of collective action remains a challenge. To address this challenge, this paper develops a degrowth perspective for strategic spatial planning as well as a strategic approach for degrowth. I argue that a degrowth transition needs to address three strategic issues: depth, agency, and trajectory. Degrowth strategies aim for satiation, the satisfaction of all essential needs in a particular society. To do so, they rely on diffused societal power, raising from existing practices of reduction. Strategies also follow a nonlinear trajectory that seeks to prefigure satiation, popularize it among the masses, and then pressure existing institutions. Strategic spatial planning offers important insights for dealing with these challenges but needs to embrace satiation as a strategic goal. It can do so by creating complementarities between prefigurative practices that perform satiation. The article defines and illustrates these processes by looking at the making of Amsterdam's 'doughnut' strategy.

We analyse the demand for goods which the consumer has an aversion to consuming in mixtures. Examples are presented. It is suggested that the axiom of non‐satiation should be relaxed in order for the model to be internally consistent. The indifference map with mixture aversion and satiation is constructed and is shown to have very unusual properties. It is then demonstrated that constrained maximization of the underlying utility function can result in both goods being consumed. It is also demonstrated that the type of goods analysed here can exhibit the rare characteristic of Giffenity.