RESUMEN
On November 5-8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The conference gathered a community of actively publishing experts in disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset of conference attendees concluded that there is a realistic possibility that Mars hosts indigenous microbial life. A powerful theme that permeated the conference is that the key to the search for martian extant life lies in identifying and exploring refugia ("oases"), where conditions are either permanently or episodically significantly more hospitable than average. Based on our existing knowledge of Mars, conference participants highlighted four potential martian refugium (not listed in priority order): Caves, Deep Subsurface, Ices, and Salts. The conference group did not attempt to reach a consensus prioritization of these candidate environments, but instead felt that a defensible prioritization would require a future competitive process. Within the context of these candidate environments, we identified a variety of geological search strategies that could narrow the search space. Additionally, we summarized a number of measurement techniques that could be used to detect evidence of extant life (if present). Again, it was not within the scope of the conference to prioritize these measurement techniques-that is best left for the competitive process. We specifically note that the number and sensitivity of detection methods that could be implemented if samples were returned to Earth greatly exceed the methodologies that could be used at Mars. Finally, important lessons to guide extant life search processes can be derived both from experiments carried out in terrestrial laboratories and analog field sites and from theoretical modeling.
Asunto(s)
Exobiología , Medio Ambiente Extraterrestre , Marte , Cuevas , Simulación por Computador , Hielo , Vuelo EspacialRESUMEN
Numerical models have been highly successful in simulating global carbon and nutrient cycles in today's ocean, together with observed spatial and temporal patterns of chlorophyll and plankton biomass at the surface. With this success has come some confidence in projecting the century-scale response to continuing anthropogenic warming. There is also increasing interest in using such models to understand the role of plankton ecosystems in past oceans. However, today's marine environment is the product of billions of years of continual evolution-a process that continues today. In this paper, we address the questions of whether an assumption of species invariance is sufficient, and if not, under what circumstances current model projections might break down. To do this, we first identify the key timescales and questions asked of models. We then review how current marine ecosystem models work and what alternative approaches are available to account for evolution. We argue that for timescales of climate change overlapping with evolutionary timescales, accounting for evolution may to lead to very different projected outcomes regarding the timescales of ecosystem response and associated global biogeochemical cycling. This is particularly the case for past extinction events but may also be true in the future, depending on the eventual degree of anthropogenic disruption. The discipline of building new numerical models that incorporate evolution is also hugely beneficial in itself, as it forces us to question what we know about adaptive evolution, irrespective of its quantitative role in any specific event or environmental changes.
RESUMEN
BACKGROUND: Genetic predisposition is involved in only 10% of patients with breast cancer. This study was to evaluate the impact of prophylactic surgery. PATIENTS AND METHODS: This is a retrospective study of 61 patients who received prophylactic breast surgery. Data collection was carried out through the computer file of the ICO. The inclusion criteria were: patients who benefited from a bilateral prophylactic mastectomy. There were no exclusion criteria. Patients received a satisfaction questionnaire to complete. RESULTS: Our study included 61 patients, 67% had a history of breast cancer. Bilateral prophylactic surgery was performed in 40 patients. It was made an average of two interventions, 44.3% of them presented postoperative complications, 18% recovery. Forty-three patients were satisfied with the medical information before surgery. The end result matched the expectations of 54.4% and 67.4% of patients would be ready to start. It was found pain associated with breast surgery in 56.5% of patients and almost half reported a change in their sexual life. DISCUSSION AND CONCLUSION: Prophylactic mastectomy is the most effective technique to prevent the risk of breast cancer. The consequences of such an action are important. It is necessary to better select patients who would benefit most from this type of surgery.