Primordial molecular clouds

It is now well known that a primordial chemistry, involving light elements produced during the nucleosynthesis period, might develop during the hydrogen post-recombination era. In particular, molecular ions and primordial molecules such as H2, HD and LiH will be produced. We summarize this primordial chemistry after the recombination epoch, and then present a simple gravitational collapse model of a cloud. The potentiality of fragmentation of this collapsing protoclouds through the thermal instability is also discussed. We suggest that this study could also be extended to the CO molecule, because the carbon reservoir molecule CO has already been observed in high redshifts objects.Comment: 12 pages, 1 figures, Invited Talk at 3K Cosmology Conference-Roma October 9

A targeted management of the nutrient solution in a soilless tomato crop according to plant needs

The adoption of closed soilless systems is useful in minimizing the environmental impact of the greenhouse crops. Instead, a significant problem in closed soilless systems is represented by the accumulation of ions in the recycled nutrient solution (NS), in particular the unabsorbed or poorly absorbed ones. To overcome such problem, we: (1) studied the effect of several values of the electrical conductivity (EC) of NS in a NFT (Nutrient Film Technique) system on a cherry type tomato crop, and (2) define a NS (called recovery solution), based on the concept of uptake concentration and transpiration-biomass ratio, that fits the real needs of the plant with respect to water and nutrients. Three levels of EC set point (SP), above which the NS was completely replaced (SP5, SP7.5, and SP10 for the EC limit of 5, 7.5, and 10 dS m(-1), respectively), were established. The SP10 treatment yield was not different from other treatments, and it allowed a better quality of the berries (for dry matter and total soluble solids) and higher environmental sustainability due to a lower discharge of total nutrients into the environment (37 and 59% with respect to SP7.5 and SP5, respectively). The recovery solution used in the second trial allowed a more punctual NS management, by adapting to the real needs of the crop. Moreover, it allowed a lesser amount of water and nutrients to be discharged into the environment and a better use of brackish water, due to a more accurate management of the EC of the NS. The targeted management, based on transpirationbiomass ratio, indicates that, in some stages of the plant cycle, the NS used can be diluted, in order to save water and nutrients. With such management a closed cycle can be realized without affecting the yield, but improving the quality of the tomato berries

Stem-Like Adaptive Aneuploidy and Cancer Quasispecies

We analyze and reinterpret experimental evidence from the literature to argue for an ability of tumor cells to self-regulate their aneuploidy rate. We conjecture that this ability is mediated by a diversification factor that exploits molecular mechanisms common to embryo stem cells and, to a lesser extent, adult stem cells, that is eventually reactivated in tumor cells. Moreover, we propose a direct use of the quasispecies model to cancer cells based on their significant genomic instability (i.e. aneuploidy rate), by defining master sequences lengths as the sum of all copy numbers of physically distinct whole and fragmented chromosomes. We compute an approximate error threshold such that any aneuploidy rate larger than the threshold would lead to a loss of fitness of a tumor population, and we confirm that highly aneuploid cancer populations already function with aneuploidy rates close to the estimated threshold

New Synthetic Approaches to Alk-1-enyl Sulfones and Sulfoxides

This thesis is devoted to the finding of new synthetic approaches to alk-1-enyl sulfones and sulfoxides. In particular, uncomplexed organoaluminum reagents reacted with aluminium sulfinates to afford alkenyl sulfoxides in good yields (72-75%). Sulfonyl chlorides reacted with pyridine-complexed alanes in the presence of PPh3 to afford sulfoxides in up to 94% yields; a reasonable mechanism is proposed. Sulfinyl chlorides react with alkynyl aluminium reagents to give alkynyl sulfoxides in modest yields (43-57%). Pyridine-complexed organoalanes react with sulfonyl chlorides in the presence of Ph3PO to give alkenyl sulfones in good yields (75%). Uncomplexed organoalanes reacted with pyridine-sulfonyl chloride complexes to afford sulfones in variable yields (40-90%). Finally, N-acyl-2-alkenyl-2H-dihydropyridine and dihydroisoquinoline derivatives are obtained via reaction of organoalane-pyridine complexes with acid halides