[en] The area covered by the Medina del Campo Groundwater Body (Duero River Basin, Spain) is an important agricultural production region. The area is prone to climatic and geomorphological hazards such as floods, dry spells and landslides. Climate projections indicate that these hazards might become more frequent in the future. The main economic activity of the area is agriculture, which is also the main water user almost entirely relying on groundwater. Currently there are more than 5000 wells pumping groundwater to supply the agricultural water demand. Measurements show that groundwater levels have declined up to 20 m in some areas in the last 40 years. In the framework of the NAIAD H2O20 project we developed a 3D numerical groundwater flow model with the objective to understand the dynamics of the groundwater, to evaluate the impact of climate change, and to assess the potential of some Nature Based Solutions (NBS) for recovering the original ecosystem services of the groundwater body. The model was built to simulate a pristine system without abstractions, and a system under anthropic pressure with the current abstractions. The NBS simulated include the artificial recharge of the aquifer, the change of crops, and the modification of abstraction rates and distribution. The preliminary results indicate that under a scenario of climate change with reduced precipitation, although the assessed NBS solutions can be beneficial, they are not able to totally reverse the impact caused by the abstractions, and therefore do not succeed to completely restore the original ecosystem services of the groundwater body.

[en] Human cells respond to carcinogen-induced damage in their DNA in at least two ways. The first response, excision repair, proceeds by at least three variations, depending on the nature of the damage. Nucleotide excision results in relatively large repair patches but few free DNA breaks, since the endonuclease step is limiting. Apurinic repair is characterized by the appearance of numerous breaks in the DNA and by short repair patches. The pathways behave as though they function independently. Lymphoic cells derived from a xeroderma pigmentosum complementation group C patient are deficient in their ability to perform nucleotide excision and also to excise 6 methoxyguanine adducts, but they are apurinic repair competent. Organisms may bypass damage in their DNA. Lymphoblastoid cells, including those derived from xeroderma pigmentosum treated with ³H-anti-BPDE, can replicate their DNA at low doses of carcinogen. Unexcised ³H is found in the light or parental strand of the resulting hybrid DNA when replication occurs in medium with BrdUrd. This observation indicates a bypass reaction occurring by a mechanism involving branch migration at DNA growing points. Branch migration in DNA preparations have been observed, but the evidence is that most occurs in BrdUrd-containing DNA during cell lysis. The measurement of the bifilarly substituted DNA resulting from branch migration is a convenient method of estimating the proportion of new synthesis remaining in the vicinity of the DNA growing point. Treatment with carcinogens or caffeine results in accumulation of DNA growing points accompanied by the synthesis of shortened pieces of daughter DNA

[en] Short communication