Carotenoid Raman signatures are better preserved in dried cells of the desert cyanobacterium Chroococcidiopsis than in hydrated counterparts after high-dose gamma irradiation

Carotenoids are promising targets in our quest to search for life on Mars due to their biogenic origin and easy detection by Raman spectroscopy, especially with a 532 nm excitation thanks to resonance effects. Ionizing radiations reaching the surface and subsurface of Mars are however detrimental for the long-term preservation of biomolecules. We show here that desiccation can protect carotenoid Raman signatures in the desert cyanobacterium Chroococcidiopsis sp. CCMEE 029 even after high-dose gamma irradiation. Indeed, while the height of the carotenoids Raman peaks was considerably reduced in hydrated cells exposed to gamma irradiation, it remained stable in dried cells irradiated with the highest tested dose of 113 kGy of gamma rays, losing only 15-20% of its non-irradiated intensity. Interestingly, even though the carotenoid Raman signal of hydrated cells lost 90% of its non-irradiated intensity, it was still detectable after exposure to 113 kGy of gamma rays. These results add insights into the preservation potential and detectability limit of carotenoid-like molecules on Mars over a prolonged period of time and are crucial in supporting future missions carrying Raman spectrometers to Mars’ surface

Architecture and permeability structure of the Sibillini Mts. Thrust and influence upon recent, extension-related seismicity in the central Apennines (Italy) through fault-valve behavior

The central Apennines are a fold-thrust belt currently affected by post-orogenic ex-tensional seismicity. To constrain the influ-ence that the inherited thrust-related struc-tures exert on the present seismic behavior of the belt, we provide the high-resolution structural and hydraulic characterization of one of the most external exposed thrust fault systems of the central Apennines, the Sibil-lini Mts. Thrust Front (STF). We integrate structural mapping, multiscale structural analysis, and in situ air permeability on the brittle structural facies of the thrust zone. We also performed K-Ar dating of selected fault rocks to better constrain structural in-heritance. The STF is defined by a complex, similar to 300-m-thick deformation zone involving Meso-Cenozoic marl and limestone that re-sults from the accommodation of both seis-mic and aseismic slip during shortening. Permeability measurements indicate that the low permeability (10-2 divided by 10-3 D) of the marly rich host rock diminishes within the thrust zone, where the principal slip surfaces and associated S-C structures represent efficient hydraulic barriers (permeability down to similar to 3 x 10-10 D) to sub-vertical fluid flow. Field data and K-Ar dating indicate that the STF began its evolution ca. 7 Ma (early Messin-ian). We suggest that the studied thrust zone may represent a barrier for the upward migration of deep fluids at the hypocentral depth of present-day extensional earth-quakes. We also speculate on the influence that similar deformation zones may have at depth on the overall regional seismotectonic pattern by causing transient fluid overpres-sures and, possibly, triggering cyclic exten-sional earthquakes on normal faults prone to slip while crosscutting the earlier thrust zones (as per a classic fault valve behavior). This mechanism may have controlled the ori-gin of the 2016-2017 central Apennines dev-astating earthquakes

A Multidisciplinary Approach to Earthquake Research: Implementation of a Geochemical Geographic Information System for the Gargano Site, Southern Italy

A priority task for correct environmental planning is to evaluate Natural Hazards, especially in highly populated areas. In particular, thorough investigations based on different Earth Science techniques must be addressed for the Seismic Hazard Assessment (SHA) in tectonically active areas. Not only the management but also the multidisciplinary analysis of all the SHA-related data sets is best performed using a Geographic Information System. In this paper we show how a researchoriented GIS is built and used in a practical case. The Geochemical Geographic Information System (G2IS) was developed and applied to the Gargano promontory (southern Italy) in the framework of an EC research project, the Geochemical Seismic Zonation (GSZ) Project. This multidisciplinary – multiscaling powerful tool is described in its structure, updating procedures and manipulation techniques. Preliminary results are presented on the detection of geochemically active fault zones and their correlation with remote sensing data and other evidences of seismogenic structures.Published255-278JCR Journalreserve

U and Th content in the Central Apennines continental crust: a contribution to the determination of the geo-neutrinos flux at LNGS

The regional contribution to the geo-neutrino signal at Gran Sasso National Laboratory (LNGS) was determined based on a detailed geological, geochemical and geophysical study of the region. U and Th abundances of more than 50 samples representative of the main lithotypes belonging to the Mesozoic and Cenozoic sedimentary cover were analyzed. Sedimentary rocks were grouped into four main "Reservoirs" based on similar paleogeographic conditions and mineralogy. Basement rocks do not outcrop in the area. Thus U and Th in the Upper and Lower Crust of Valsugana and Ivrea-Verbano areas were analyzed. Based on geological and geophysical properties, relative abundances of the various reservoirs were calculated and used to obtain the weighted U and Th abundances for each of the three geological layers (Sedimentary Cover, Upper and Lower Crust). Using the available seismic profile as well as the stratigraphic records from a number of exploration wells, a 3D modelling was developed over an area of 2^{\circ}x2^{\circ} down to the Moho depth, for a total volume of about 1.2x10^6 km^3. This model allowed us to determine the volume of the various geological layers and eventually integrate the Th and U contents of the whole crust beneath LNGS. On this base the local contribution to the geo-neutrino flux (S) was calculated and added to the contribution given by the rest of the world, yielding a Refined Reference Model prediction for the geo-neutrino signal in the Borexino detector at LNGS: S(U) = (28.7 \pm 3.9) TNU and S(Th) = (7.5 \pm 1.0) TNU. An excess over the total flux of about 4 TNU was previously obtained by Mantovani et al. (2004) who calculated, based on general worldwide assumptions, a signal of 40.5 TNU. The considerable thickness of the sedimentary rocks, almost predominantly represented by U- and Th- poor carbonatic rocks in the area near LNGS, is responsible for this difference.Comment: 45 pages, 5 figures, 12 tables; accepted for publication in GC

Soil deformation analysis through fluid-dynamic modelling and DInSAR measurements: a focus on groundwater withdrawal in the Ravenna area (Italy)

This study aims at assessing the deformation processes affecting an area NW of the city of Ravenna (northern Italy), caused by groundwater withdrawal activities. In situ data, geologic and structural maps, piezometric measurements, underground water withdrawal volumes, and satellite C-band SAR data were used to jointly exploit two different techniques: 1) fluid-dynamic and geomechanical modelling (by RSE S.p.A), and 2) Differential Synthetic Aperture Radar Interferometry (DInSAR) analysis (by CNR - IREA). The results of the comparative analysis presented in this work brought new evidence about the contribution of groundwater withdrawal to the total subsidence affecting the area during the 2000-2017 time interval. In particular, they show an increase of the subsidence from year 2000 to 2010 and a decrease from year 2010 to 2017. These results are generally in line with groundwater withdrawal data that report a reduction of the extracted water volumes during the considered temporal interval. Meantime, they show a delay effect in the subsidence process, partially recovered during the 2010-2017 thanks to a stabilisation of the extracted groundwater volumes. The presented results shade new light on the groundwater withdrawal contribution to the subsidence of the analysed zone, although further investigations are foreseen to better clarify the ongoing scenario

Silver nanowire networks: Physical properties and potential integration in solar cells

peer reviewedWith the growing interest in flexible electronics and the increased utilization of Indium Tin Oxide electrodes for display and photovoltaic applications the need for new materials is emerging. In this work we present the electro-optical properties of Ag nanowire networks as an alternative transparent conductive material. A comparison of different film deposition techniques is made and indicates that the properties of the network are independent of the fabrication method. Analysis of the electrical behavior as a function of nanowire density is made and compared with theoretical results as well as Monte Carlo simulations. Thermal annealing is shown to reduce the sheet resistance from 1000 Ω/sq to 8 Ω/sq; this reduction is achieved by local sintering of the nanowire junctions. Experimental optimization of Ag nanowire electrodes was undertaken and a peak in the electro-optical properties is observed at approximately 100 mg/m². Finally a discussion of the potential integration of Ag nanowire networks into solar cells is undertaken; we observe that these electrodes show promise as an emerging transparent conductive material, especially for flexible applications

To other planets with upgraded millennial kombucha in rhythms of sustainability and health support

Humankind has entered a new era of space exploration: settlements on other planetary bodies are foreseen in the near future. Advanced technologies are being developed to support the adaptation to extraterrestrial environments and, with a view on the longer term, to support the viability of an independent economy. Biological processes will likely play a key role and lead to the production of life-support consumables, and other commodities, in a way that is cheaper and more sustainable than exclusively abiotic processes. Microbial communities could be used to sustain the crews’ health as well as for the production of consumables, for waste recycling, and for biomining. They can self-renew with little resources from Earth, be highly productive on a per-volume basis, and be highly versatile—all of which will be critical in planetary outposts. Well-de!ned, semi-open, and stress-resistant microecosystems are particularly promising. An instance of it is kombucha, known worldwide as a microbial association that produces an eponymous, widespread soft drink that could be valuable for sustaining crews’ health or as a synbiotic (i.e., probiotic and prebiotic) after a rational assemblage of de!ned probiotic bacteria and yeasts with endemic or engineered cellulose producers. Bacterial cellulose products offer a wide spectrum of possible functions, from leather-like to innovative smart materials during long-term missions and future activities in extraterrestrial settlements. Cellulose production by kombucha is zero-waste and could be linked to bioregenerative life support system (BLSS) loops. Another advantage of kombucha lies in its ability to mobilize inorganic ions from rocks, which may help feed BLSS from local resources. Besides outlining those applications and others, we discuss needs for knowledge and other obstacles, among which is the biosafety of microbial producers