Integral control for population management

We present a novel management methodology for restocking a declining population. The strategy uses integral control, a concept ubiquitous in control theory which has not been applied to population dynamics. Integral control is based on dynamic feedback-using measurements of the population to inform management strategies and is robust to model uncertainty, an important consideration for ecological models. We demonstrate from first principles why such an approach to population management is suitable via theory and examples

Ibuprofen results in alterations of human fetal testis development

International audienceAmong pregnant women ibuprofen is one of the most frequently used pharmaceutical compounds with up to 28% reporting use. Regardless of this, it remains unknown whether ibuprofen could act as an endocrine disruptor as reported for fellow analgesics paracetamol and aspirin. To investigate this, we exposed human fetal testes (7-17 gestational weeks (GW)) to ibuprofen using ex vivo culture and xenograft systems. Ibuprofen suppressed testosterone and Leydig cell hormone INSL3 during culture of 8-9 GW fetal testes with concomitant reduction in expression of the steroidogenic enzymes CYP11A1, CYP17A1 and HSD17B3, and of INSL3. Testosterone was not suppressed in testes from fetuses younger than 8 GW, older than 10-12 GW, or in second trimester xenografted testes (14-17 GW). Ex vivo, ibuprofen also affected Sertoli cell by suppressing AMH production and mRNA expression of AMH, SOX9, DHH, and COL2A1. While PGE2 production was suppressed by ibuprofen, PGD2 production was not. Germ cell transcripts POU5F1, TFAP2C, LIN28A, ALPP and KIT were also reduced by ibuprofen. We conclude that, at concentrations relevant to human exposure and within a particular narrow 'early window' of sensitivity within first trimester, ibuprofen causes direct endocrine disturbances in the human fetal testis and alteration of the germ cell biology

In competition with a brother: Women's inheritance positions in contemporary Swedish family forestry

Swedish family forestry is characterized by traditional perceptions of the farm as a project that spans generations and a strong desire to preserve family ownership in accordance with a paternal inheritance tradition. In this study women's inheritance positions in contemporary family forestry in Sweden were examined using three different sources: (1) a national register of all forest owners; (2) an inquiry study; and (3) narrative accounts from female forest owners. An asymmetrical ownership pattern was exposed in the analysis of all three materials. Gender had an impact on who, what and how family owned forest land was transferred from one generation to another. Furthermore, analysis of the narrative accounts showed that a minority of the women corresponded to the concept transitive element. A typology with three additional concepts, namely transitive agent, transformative element and transformative agent, is therefore suggested and discussed