Detection of Pristine Gas Two Billion Years after the Big Bang

In the current cosmological model, only the three lightest elements were created in the first few minutes after the Big Bang; all other elements were produced later in stars. To date, however, heavy elements have been observed in all astrophysical environments. We report the detection of two gas clouds with no discernible elements heavier than hydrogen. These systems exhibit the lowest heavy-element abundance in the early universe and thus are potential fuel for the most metal poor halo stars. The detection of deuterium in one system at the level predicted by primordial nucleosynthesis provides a direct confirmation of the standard cosmological model. The composition of these clouds further implies that the transport of heavy elements from galaxies to their surroundings is highly inhomogeneous.Comment: 32 pages, 11 figures, SOM included. To appear in Scienc

STRAWBERRY (FRAGARIA X ANANASSA DUCH.) TANNINS AS INGREDIENTS OF NUTRACEUTICALS WITH POTENTIAL ANTI-GASTRITIS PROPERTIES

Gastritis is an inflammatory-based disease, involving millions of people in the world. Helicobacter pylori (H. pylori) is the main cause of inflammation at the gastric level, inducing the expression and release of different pro-inflammatory cytokines (ex. IL-8 and IL-6) by gastric epithelial cells. The presence of H. pylori results also in reactive oxygen species (ROS) production by the gastric mucosa; gastric epithelial cells contribute to the production of ROS, thus exacerbating oxidative stress in this district. Strawberry is one of the most commonly consumed fruits in the world and it is an important source of sugars, vitamins, fibers, micronutrients and polyphenols, including anthocyanosides (i.e. pelargonidin and cyanidin glycosides) and tannins. Condensed (procyanidins) and hydrolysable tannins (especially ellagitannins, such as agrimoniin) are among the most abundant polyphenols. Although tannins are important components of strawberries, until now the activity of these strawberry compounds, on gastric inflammation, is unknown. In the present study, the chemical profile and the biological properties of tannin-enriched extracts from strawberries were analyzed in cell models of gastric inflammation, considering also the chemical and biological features of strawberry tannins after in vitro simulated gastric digestion. The anti-inflammatory activities of pure strawberry tannins were assayed to get mechanistic insights. Tannin-enriched extracts from strawberries inhibit IL-8 secretion in TNF\u3b1-treated human tumour gastric epithelial cells (AGS) by dampening the NF-\u3baB signaling. In vitro simulated gastric digestion slightly affects the chemical composition and the biological properties of strawberry tannins. By using pure compounds, I found that casuarictin may act as a pure NF-B inhibitor while agrimoniin inhibits IL-8 secretion also acting on other biological targets; in our system procyanidin B1 prevents the TNF\u3b1-induced effects without interfering with the NF-\u3baB pathway. The effects of strawberry tannins are maintained in normal gastric epithelial cells (GES-1) showing an inhibitory effect on NF-\u3baB activity and the expression and release of some pro-inflammatory mediators (like IL-8, IL-6 and MMP-9). Comparing the IC50s between AGS and GES-1 cells, the activity of strawberry tannins appear slightly higher in AGS cells than in GES-1 cells. Compounds from strawberry are able to counteract H. pylori-induced IL-8 release in both GES-1 and AGS cells, although the effect appears at higher concentrations than in TNF\u3b1-treated cells. Concentrations showing efficacy are easily reachable in vivo after with a moderate consumption of the fruit. Agrimoniin and casuarictin are able to exert an antioxidant activity in a cell-free system and to suppress basal Nrf2 activation. Taken together these results suggest that strawberry tannins, even after in vitro simulated gastric digestion, exert anti-inflammatory activities at nutritionally relevant concentrations

Potential Response of Soil-Borne Fungal Pathogens Affecting Crops to a Scenario of Climate Change in Europe

A study was carried out on the potential response of soil-borne pathogens causing crop yield losses under a climate change scenario in Europe. A controlled chamber set of experiments was carried out to quantify pathogen response to temperature using pure colonies of three soil-borne fungi, representative of low (Fusarium nivale), medium-high (Athelia rolfsii) and high (Macrophomina phaseolina) temperature requirements. A generic model to simulate fungal growth response to temperature based on these experiments was developed and linked to a soil temperature model component, and to components to simulate soil water content accounting for crop water uptake of potential hosts. Pathogens relative growth was simulated over Europe using the IPCC A1B emission scenario as realization of the Hadley-CM3 global climate model, available from the European Commission and processed for use with biophysical models. The simulations resulting from using the time span centred on 2030 were compared to the baseline, centred on the year 2000, using a sample of 30 years of daily weather. The general trend of soil-borne pathogens response to the scenario of climate change is a relative increase in growth in colder areas of Europe, as a function of their temperature requirements. Projections of F. nivale in the future indicate a relative increase of this winter pathogen of wheat in Northern European countries. A. rolfsii and M. phaseolina, two soil-borne pathogens typical of warmer agricultural areas, could find more favourable conditions in areas of the Central Europe, but they differentiated in Southern Europe where A. rolfsii resulted affected by summer soil temperatures above optimum