Bacterial survival in Martian conditions

We shortly discuss the observable consequences of the two hypotheses about the origin of life on Earth and Mars: the Lithopanspermia (Mars to Earth or viceversa) and the origin from a unique progenitor, that for Earth is called LUCA (the LUCA hypothesis). To test the possibility that some lifeforms similar to the terrestrial ones may survive on Mars, we designed and built two simulators of Martian environments where to perform experiments with different bacterial strains: LISA and mini-LISA. Our LISA environmental chambers can reproduce the conditions of many Martian locations near the surface trough changes of temperature, pressure, UV fluence and atmospheric composition. Both simulators are open to collaboration with other laboratories interested in performing experiments on many kind of samples (biological, minerals, electronic) in situations similar to that of the red planet. Inside LISA we have studied the survival of several bacterial strains and endospores. We verified that the UV light is the major responsible of cell death. Neither the low temperature, nor the pressure, nor the desiccation or the atmospheric changes were effective in this sense. We found that some Bacillus strains have a particular capability to survive for some hours in Martian conditions without being screened by dust or other shields. We also simulated the coverage happening on a planet by dust transported by the winds, blowing on the samples a very small quantity of volcanic ash grains or red iron oxide particles. Samples covered by these dust grains have shown a high percentage of survival, indicating that under the surface dust, if life were to be present on Mars in the past, some bacteria colonies or cells could still be present.Comment: 5 pages, 3 figures, special issue of Planetary and Space science on Methane on Mars discovery. Topics: Astrobiology - Methods: laboratory - Mars - Panspermi

New approaches to the exploration: planet Mars and bacterial life

Planet Mars past environmental conditions were similar to the early Earth, but nowadays they are similar to those of a very cold desert, irradiated by intense solar UV light. However, some terrestrial lifeform showed the capability to adapt to very harsh environments, similar to the extreme condition of the Red Planet. In addition, recent discoveries of water in the Martian permafrost and of methane in the Martian atmosphere, have generated optimism regarding a potentially active subsurface Mars' biosphere. These findings increase the possibility of finding traces of life on a planet like Mars. However, before landing on Mars with dedicated biological experiments, it is necessary to understand the possibilities of finding life in the present Martian conditions. Finding a lifeform able to survive in Martian environment conditions may have a double meaning: increasing the hope of discovering extraterrestrial life and defining the limits for a terrestrial contamination of planet Mars. In this paper we present the Martian environment simulators LISA and mini-LISA, operating at the Astronomical Observatory of Padua, Italy. They have been designed to simulate the conditions on the surface of planet Mars (atmospheric pressure,0.6-0.9 kPa; temperature from -120 to 20 {\deg}C, Martian-like atmospheric composition and UV radiation). In particular, we describe the mini-LISA simulator, that allows to perform experiments with no time limits, by weekly refueling the liquid nitrogen reservoir. Various kind of experiments may be performed in the simulators, from inorganic chemistry to biological activity. They are offered as experimental facilities to groups interested in studying the processes that happen on the Martian surface or under its dust cover.Comment: This paper should be published in the Proceedings of IAU Symposium 269, "Galileo's Medicean Moons: Their impact on 400 years of discovery", printed by Cambridge University Press, but for an error of the editors was not included in the printed versio

Common-mode rejection in Martin-Puplett spectrometers for astronomical observations at mm-wavelengths

The Martin-Puplett interferometer (MPI) is a differential Fourier transform spectrometer (FTS), measuring the difference between spectral brightness at two input ports. This unique feature makes the MPI an optimal zero instrument, able to detect small brightness gradients embeddend in a large common background. In this paper we investigate experimentally the common-mode rejection achievable in the MPI at mm wavelengths, and discuss the use of the instrument to measure the spectrum of cosmic microwave background (CMB) anisotropy

Endocannabinoid-related compounds in gastrointestinal diseases

The endocannabinoid system (ECS) is an endogenous signalling pathway involved in the control of several gastrointestinal (GI) functions at both peripheral and central levels. In recent years, it has become apparent that the ECS is pivotal in the regulation of GI motility, secretion and sensitivity, but endocannabinoids (ECs) are also involved in the regulation of intestinal inflammation and mucosal barrier permeability, suggesting their role in the pathophysiology of both functional and organic GI disorders. Genetic studies in patients with irritable bowel syndrome (IBS) or inflammatory bowel disease have indeed shown significant associations with polymorphisms or mutation in genes encoding for cannabinoid receptor or enzyme responsible for their catabolism, respectively. Furthermore, ongoing clinical trials are testing EC agonists/antagonists in the achievement of symptomatic relief from a number of GI symptoms. Despite this evidence, there is a lack of supportive RCTs and relevant data in human beings, and hence, the possible therapeutic application of these compounds is raising ethical, political and economic concerns. More recently, the identification of several EC-like compounds able to modulate ECS function without the typical central side effects of cannabinomimetics has paved the way for emerging peripherally acting drugs. This review summarizes the possible mechanisms linking the ECS to GI disorders and describes the most recent advances in the manipulation of the ECS in the treatment of GI diseases

Polarization and high resolution parametric spectral analisys applied to the seismic signals recorded on the Marsili submarine volcano

The Ocean Bottom Seismometer with Hydrophone deployed by the Gibilmanna OBS Lab (CNT-INGV) from the 12th to the 21st July 2006 on the flat top of the Marsili submarine volcano (790m of depth) recorded more than 1000 seismic events. By comparing them with the ones recorded in other volcanic areas and described in literature (Wassermann, 2002; McNutt, 2002; Díaz et al., 2007), we grouped these events in three categories: 817 VTB (Volcanic-Tectonic type B) events, 159 HF (High Frequency) events and 53 SDE’s (Short Duration Event). Small-magnitude VTB swarms, with frequency band between 2 and 6 Hz and mean time length of about 30 seconds, were almost all recorded in the first 7 days, while in the last 2 days, OBS recorded HF events with frequency band over 40 Hz and few minutes of length. Signals with similar frequency and time domain features are associated, to hydrothermal activity (Ohminato, 2006). The SDE waveform, characterized by a monochromatic signal with a slowly decaying envelope, is generated by oscillations of a resonant body excited by magmatic or hydrothermal activity (Chouet, 1996). We applied, to all the signals dataset, polarization and high resolution parametric spectral analysis. This kind of study allowed to mark the VTB events as multi P-phase events with shallow sources placed in a narrow azimuthal window as regards the OBS/H position. The seismogenetic volume is probably located in the North-East sector of the Marsili building. The high resolution parametric spectral analysis of the SDE signals allowed to find with high accuracy their dominant complex frequencies (!=f+ig). Plotting them in the complex frequencies plane we identified two distinct clusters with middle complex frequencies f=7.8s^−1, g=-0.35s^−1 and f=7.5s^−1, g=-0.47s^−1 respectively. These two clusters are probably linked two different seismogenetic volumes

SNES - Seismic Network Evaluation through Simulation: an application to the Italian RSNC-INGV

earthquakes simulation (SNES - Seismic Networks Evaluation through Simulation). To be applied, the SNES method require: P and S velocity models, seismic attenuation law, seismic stations positions and their experimental noise spectra and, finally, an empirical law that link the variance of the residual times of a station to the hypocenter position. This method allow to map the confidence interval estimates of the hypocentral parameters as function of magnitude, focus depth and confidence level. The simulation was carried out assuming that the epicentres of synthetic earthquakes are located in the knots of a square grid which was covering the investigated area. For each synthetic earthquake, the seismic spectrum was calculated in every station to determine the local Signal to Noise Ratio (SNR): the set of active stations in the location procedure and the relative azimuthal gap was determined by a threshold value of this parameter. Finally, the covariance matrix of synthetic data and the partial derivatives of the model were determined and used to estimate the covariance matrix of the hypocentral parameters. This method was applied to the Italian RSNC-INGV to evaluate its location performance, with a 95% confidence level. This simulation was carried out for small magnitude earthquakes (1.5<ML<3, H=10km), both using only P arrival times and P and S arrival times. This simulation allowed to highlight some zones of the Italian peninsula and its surrounding seas that need an improvement of the seismic network. We show how the Ocean Bottom Seismometers can play an important role in this network improvement

Spatial and temporal hot spots of Aedes albopictus abundance inside and outside a South European metropolitan area

Aedes albopictus is a tropical invasive species which in the last decades spread worldwide, also colonizing temperate regions of Europe and US, where it has become a public health concern due to its ability to transmit exotic arboviruses, as well as severe nuisance problems due to its aggressive daytime outdoor biting behaviour. While several studies have been carried out in order to predict the potential limits of the species expansions based on eco-climatic parameters, few studies have so far focused on the specific effects of these variables in shaping its micro-geographic abundance and dynamics. The present study investigated eco-climatic factors affecting Ae. albopictus abundance and dynamics in metropolitan and sub-urban/rural sites in Rome (Italy), which was colonized in 1997 and is nowadays one of the most infested metropolitan areas in Southern Europe. To this aim, longitudinal adult monitoring was carried out along a 70 km-transect across and beyond the most urbanized and densely populated metropolitan area. Two fine scale spatiotemporal datasets (one with reference to a 20m circular buffer around sticky traps used to collect mosquitoes and the second to a 300m circular buffer within each sampling site) were exploited to analyze the effect of climatic and socio-environmental variables on Ae. albopictus abundance and dynamics along the transect. Results showed an association between highly anthropized habitats and high adult abundance both in metropolitan and sub-urban/ rural areas, with “small green islands” corresponding to hot spots of abundance in the metropolitan areas only, and a bimodal seasonal dynamics with a second peak of abundance in autumn, due to heavy rains occurring in the preceding weeks in association with permissive temperatures. The results provide useful indications to prioritize public mosquito control measures in temperate urban areas where nuisance, human-mosquito contact and risk of local arbovirus transmission are likely higher, and highlight potential public health risks also after the summer months typically associated with high mosquito densities

Signals and Power Distribution in the CMS Inner Tracker

\begin{abstract} This Note describes how the interconnection between the 3540 modules of the CMS Inner Tracker has been approached, focusing on the signal, high voltage and low voltage line distribution. The construction and tests of roughly a thousand interconnects called ``Mother Cables" is described. \end{abstract

Improvement of a coastal vulnerability index and its application along the Calabria Coastline, Italy

The present paper further develops a coastal vulnerability index formulation (CVI) previously proposed by the authors by integrating a new variable and redefining three variables to improve the suitability of the index for low-lying coasts. Eleven variables are divided into three typological groups: geological, hydro-physical process and vegetation. The geological variables are: geomorphology, shoreline erosion/accretion rates, coastal slope, emerged beach width, and dune. The hydro-physical process group includes: river discharge, sea-level change, mean significant wave height and mean tide range. The vegetation variables are: vegetation behind the back-beach and coverage of Posidonia oceanica. The index was applied to a stretch of the Ionian coast in the province of Crotone in the Calabria region (Southern Italy), and a vulnerability map was produced. A geography information system (GIS) platform was used to better process the data. For the case study area, the most influential variables are shoreline erosion/accretion rates, coastal slope, emerged beach width, dune, vegetation behind the back-beach, and coverage of Posidonia oceanica. The most vulnerable transects are those near urban areas characterized by the absence of dunes and vegetation. Statistical and sensitivity analyses were performed, and the proposed CVI was compared with the previous formulation proposed by the authors and with two other CVI methods present in the literature