Estimating the potential development of Diaporthe helianthi epidemics in Italy*

Diaporthe helianthi is the causal agent of a severe sunflower disease but, in Italy, disease outbreaks are sporadic with no significant losses. The present work investigates the role of meteorological conditions on the potential development of D. helianthi epidemics in Italy, using the French model Asphodel, which simulates the effect of air temperature, relative humidity and rainfall on ascospore maturation and dispersal, infection establishment, disease onset and severity during the period of host susceptibility. Meteorological data measured in eight stations distributed from north to south Italy, over a 5‐year period (1995–99), was used as model input. Results showed that meteorological conditions in Italy are frequently favourable for D. helianthi infections on sunflower, and severe epidemics are possible. Therefore, climatic conditions are not a limiting factor for disease development in the Italian sunflower‐growing areas. The lack of disease epidemics in Italy may be related to differences in the pathogen populations compared with the French ones.     

Mixotrophy in a Local Strain of Nannochloropsis granulata for Renewable High-Value Biomass Production on the West Coast of Sweden

A local strain of Nannochloropsis granulata (Ng) has been reported as the most productive microalgal strain in terms of both biomass yield and lipid content when cultivated in photobioreactors that simulate the light and temperature conditions during the summer on the west coast of Sweden. To further increase the biomass and the biotechnological potential of this strain in these conditions, mixotrophic growth (i.e., the simultaneous use of photosynthesis and respiration) with glycerol as an external carbon source was investigated in this study and compared with phototrophic growth that made use of air enriched with 1–2% CO₂. The addition of either glycerol or CO₂-enriched air stimulated the growth of Ng and theproduction of high-value long-chain polyunsaturated fatty acids (EPA) as well as the carotenoid canthaxanthin. Bioassays in human prostate cell lines indicated the highest antitumoral activity for Ng extracts and fractions from mixotrophic conditions. Metabolomics detected betaine lipids specifically in the bioactive fractions, suggesting their involvement in the observed antitumoral effect. Genes related to autophagy were found to be upregulated by the most bioactive fraction, suggesting a possible therapeutic target against prostate cancer progression. Taken together, our results suggest that the local Ng strain can be cultivated mixotrophically in summer conditions on the west coast of Sweden for the production of high-value biomass containing antiproliferative compounds, carotenoids, and EPA.     

Toward the Identification of Novel Antimicrobial Agents: One-Pot Synthesis of Lipophilic Conjugates of N-Alkyl d- and l-Iminosugars

In the effort to improve the antimicrobial activity of iminosugars, we report the synthesis of lipophilic iminosugars 10a–b and 11a–b based on the one-pot conjugation of both enantiomeric forms of N-butyldeoxynojirimycin (NBDNJ) and N-nonyloxypentyldeoxynojirimycin (NPDNJ) with cholesterol and a succinic acid model linker. The conjugation reaction was tuned using the established PS-TPP/I₂/ImH activating system, which provided the desired compounds in high yields (94–96%) by a one-pot procedure. The substantial increase in the lipophilicity of 10a–b and 11a–b is supposed to improve internalization within the bacterial cell, thereby potentially leading to enhanced antimicrobial properties. However, assays are currently hampered by solubility problems; therefore, alternative administration strategies will need to be devised.     

High-Pressure Iron-Sulfur Compound, Fe3S2, and Melting Relations in the Fe-FeS System

An iron-sulfur compound (Fe3S2) was synthesized at pressures greater than 14 gigapascals in the system Fe-FeS. The formation of Fe3S2 changed the melting relations from a simple binary eutectic system to a binary system with an intermediate compound that melted incongruently. The eutectic temperature in the system at 14 gigapascals was about 400°C lower than that extrapolated from Usselman's data, implying that previous thermal models of Fe-rich planetary cores could overestimate core temperature. If it is found in a meteorite, the Fe3S2 phase could also be used to infer the minimum size of a parent body.     

Behaviour in soil of polyethylene film and polyethylene film additivated with starch

Effective minesoil recovery requires spoils to be converted to soils of similar quality to those previously existing on that site. The developing minesoil should thus acquire three critical capacities, namely the capacities to a) support plant production, b) degrade organic matter and c) remove contaminants from water. The degree of development of these capacities provides a useful measure of soil quality and thus of the success of a given soil recovery technique. At the Meirama lignite mine in Galicia (northwest Spain), the possibility of using cattle slurry instead of the inorganic fertilizers currently used is being investigated. The results of a number of experiments suggest that cattle slurry is more effective (in terms of the above three critical capacities) than inorganic fertilizer. In slurry-fertilized spoils, rapid increases are observed in vegetation cover, in the relative abundance of self-seeded native plant species, in soil microbial activity and in those physical and chemical properties which affect infiltration and the capacity to remove contaminants from percolating water.     

Beacon-like immunoreactivity in the hypothalamus of domestic chick

Beacon-immunoreactive (B-ir) fibres and neurons in the hypothalamus of the domestic chick (Gallus domesticus) were studied using an immunohistochemical technique in order to verify the presence and elucidate the pattern of distribution of this novel peptide in an avian brain. B-ir neurons were seen in the n. supraopticus, pars ventralis and pars externus; n. magnocellularis preopticus, pars dorsalis, medialis and ventralis; n. preopticus periventricularis; n. suprachiasmaticus, pars medialis; n. ventrolateralis thalami. Only few B-ir cells were scattered in the most anterior part of the lateral hypothalamic area. B-ir fibres, appearing as thin punctuate structures, were seen mainly along the walls of the third ventricle and in the ventromedial hypothalamus. Labelled fibres and terminals were located in the external and internal zones of the anterior and posterior median eminence. In particular, fibre terminals were seen close to the capillary loops of the hypothalamo-hypophysial portal system. The anatomical data of the present study regarding the distribution of B-ir in the chick hypothalamus suggest that beacon may play a key role in the regulation of the neuroendocrine system by acting as a neuromodulator and/or neurotransmitter.