Das Projekt "Contaminant mixtures and human reproductive health - novel strategies for health impact and risk assessment of endocrine disrupters (CONTAMED)" wird/wurde gefördert durch: Kommission der Europäischen Gemeinschaften Brüssel. Es wird/wurde ausgeführt durch: Brunel University London, Institute for the Environment.Objective: Disruption of hormonal signalling in fetal life can irreversibly affect human development and reproductive health at a later age. Of considerable concern in Europe is a decline in male semen quality and a high prevalence of congenital malformations and hormone-dependent cancers. Although it appears plausible that environmental chemicals with endocrine activity may be involved in the causation of these disorders, there is no evidence for adverse effects of individual substances at relevant human exposure levels. However, there are indications that combinations of chemicals play a cumulative role. CONTAMED aims to explore the hypothesis that combined exposure to endocrine disrupting chemicals in fetal life may lead to adverse delayed impacts on human reproductive health. To achieve this goal, CONTAMED will combine epidemiological approaches with laboratory science. The work plan for CONTAMED is organised in three major strands focusing on human studies, animal models and in vitro assays including metabolomics.
Das Projekt "Sonderforschungsbereich (SFB) 564: Nachhaltige Landnutzung und ländliche Entwicklung in Bergregionen Südostasiens; Sustainable Land Use and Rural Development in Mountainous Regions of Southeast Asia, D 1.3: Regulation of flowering in tropical fruit crops on erosion prone sites in Northern Thailand" wird/wurde gefördert durch: Deutsche Forschungsgemeinschaft / Ministry of Science and Technology (MOST) / National Research Council of Thailand (NRCT). Es wird/wurde ausgeführt durch: Universität Hohenheim, Institut für Kulturpflanzenwissenschaften, Fachgebiet Ertragsphysiologie der Sonderkulturen (340f).NRCT component: Assoc.Prof.Dr. Sruamsiri, Pittaya - Development of Clean Technology for Off-season Fruit Production: A Case Study of Mango, Longan, Litchi and Tangerine. Specific basic and applied science activities for each crop will be carried out in an attempt to solve the following issues. Longan: Previous research work has shown that flower induction can successfully be manipulated by application of KClO3. This crop is therefore an ideal model plant to investigate the regulatory mechanisms of flowering by: 1. determining acquisition and distribution of KClO3 using isotope labelling techniques and measuring enzyme activities in leaves to decide whether nitrate reductase is involved in the conversion and flower inducing activity of KClO3; 2. identifying mutual influences between hormones including their time-dependent changes brought about by manipulation of hormone biosynthesis through exogenously applied plant growth regulators (PGRs); 3. investigating the effect of off-season production systems on carbohydrate distribution and reserves. Mango: Paclobutrazol (PBZ) is already commercially used to manipulated flower induction in mango, however, the technique may not be sustainable due to its persistence in plant and soil. Prohexadione-Ca (Pro-Ca), another gibberellin biosynthesis inhibiting compound, and specific crop management techniques may prove to be successful and more sustainable alternatives to PBZ and warrant detailed investigation by: 1. evaluating appropriate time-of-season, concentration and application procedure (injection or spray) of Pro-Ca as possible alternative of PBZ and subsequent effects on hormonal status; 2. pruning or defoliation techniques which may induce a secondary flower through an altered hormonal status in the bud tissue. Litchi: There are still no proven orchard management practices for inducing off-season flowering in litchi. The main research objective is to study the significance of plant stress (pruning, girdling shoot tipping techniques, water and nutrient deficiency) on flowering signals by determining carbohydrate changes and hormonal status.
Das Projekt "Evaluation of the effects of endocrine active chemicals (EACs) for sensitive aquatic wildlife species with the test organism Potamopyrgus antipodarum (Mollusca)" wird/wurde gefördert durch: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung. Es wird/wurde ausgeführt durch: Universität Frankfurt am Main, Institut für Ökologie, Evolution und Diversität, Abteilung Aquatische Ökotoxikologie.Recent reports have shown that a number of xenobiotics in the environment are able of interfering with the normal endocrine function in animals and also in humans. Suspected effects of such compounds, often referred to as endocrine disruptors (EDs) or endocrine active chemicals (EACs), in humans include decreased sperm counts, increased cases of breast, testicular and other forms of reproductive cancers, genital abnormalities (e.g. hypospadia, cryptorchidism), premature puberty in females, and increased cases of endometriosis. In contrast to these suspicious cases in humans there is convincing evidence for chemically-induced endocrine disruption from wildlife studies. However, the overwhelming majority of investigations on effects of EACs is laboratory based and focuses on vertebrates while much less has been done in the field to address potential population-level effects. More detailed information about the effects on and mechanisms of action in invertebrates has only been obtained from a few cases although invertebrates represent more than 95Prozent of the known species in the animal kingdom. The limited number of examples for endocrine disruption in invertebrates is partially due to the fact that their hormonal systems are rather poorly understood in comparison with vertebrates. Deleterious endocrine changes following an exposure to certain compounds may therefore easily be missed or simply be unmeasurable at present, even though a number of field investigations and laboratory studies show that endocrine disruption has probably occurred. The example of tributyltin (TBT) compounds and their masculinising effects in more than 150 species of prosobranch molluscs shows that apparently trivial biochemical changes can have drastic effects up to the community level by a final sterilisation of affected females with a consequent demise and local extinction of populations. However, with the exception of TBT in marine prosobranchs, it has never been convincingly shown that EACs are capable to exert such far-reaching effects in field populations and pose a risk for their survival at environmentally relevant concentrations. The objective of the proposed project is: (1) to analyse the degree to which aquatic wildlife in central Europe is exposed to EACs in its natural habitat by assessing the well-defined effects in the test with Potamopyrgus antipodarum and (2) to evaluate the potential role of EACs for population declines of sensitive aquatic wildlife species with the example of prosobranch snails by correlating effect data with results from analyses of the macrozoobenthic community.