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

Two new species of the flea beetle genus Psylliodes Latreille of the montana species-group from Eastern Africa (Coleoptera: Chrysomelidae)

In this paper, Psylliodes afromontana sp. nov. and P. shira sp. nov., both from Eastern Africa [Kenya (Kikuyu Escarpment) and Tanzania (Kilimanjaro) respectively], are described. The two new species are attributed to the montana species-group, currently including four other wingless species occurring in the montane forests of Kenya and Tanzania: Psylliodes montana Weise, P. kikuyana Biondi, P. masai Biondi, P. manobioides Nadein. Micrographs of diagnostic characters, comprehending male and female genitalia are supplied. Ecological data for each species, including habitat preference, and phenology are also reported

Revision of Diphaulacosoma Jacoby, an endemic flea beetle genus from Madagascar, with description of three new species (Coleoptera: Chrysomelidae, Galerucinae, Alticini)

A taxonomic revision of the flea beetle genus Diphaulacosoma Jacoby, endemic to Madagascar, is provided. This genus includes seven species of which three are new to science: D. elegans sp. n., D. jenisi sp. n., and D. nigroscutis sp. n. An updated catalogue including new material, new faunistic records, distributions, chorotypes, and ecological notes is supplied. Lectotypes for Diphaulacosoma laevipenne Jacoby, D. bicolor (Weise) and D. scutellare (Weise) are designated. Additionally, the revision comprises a key for the identification of all seven species considered, habitus photos, and microscope and scanning electron micrographs of diagnostic characters, including aedeagus and spermatheca

Two new species of Chaetocnema Stephens from South Africa (Coleoptera: Chrysomelidae, Galerucinae, Alticini)

In this paper Chaetocnema adamastori sp. nov. and C. saldanhai sp. nov., both from Western Cape Province (Republic of South Africa), are described. The two new species are closely related with C. audisiana Biondi and C. capensis Bryant, respectively. Micrographs of diagnostic characters, including male and female genitalia, are supplied. Ecological data for each species, including habitat preference, host plant and phenology, are also reported

Entomological knowledge in Madagascar by GBIF datasets: estimates on the coverage and possible biases (Insecta)

Although Madagascar is one of the world's most important biodiversity hotspots, the knowledge of its faunistic diversity is still incomplete, notwithstanding many field campaigns were organized since the 17th century until nowadays, leading to a huge number of vertebrate and invertebrate records. In this contribution, taking into consideration the geographic distribution by a GBIF dataset including 286,764 records referred to nine insect orders (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, Odonata, Orthoptera, Trichoptera), we tried to supply some observations on the spatial distribution and to point out some possible biases in the entomological knowledge of Madagascar. Hymenoptera, Coleoptera and Diptera were the most represented orders in the dataset, respectively. Some orders show many "coupled" sampling, with peaks of shared sampled localities between Diptera with Hymenoptera (98.07%) and Hemiptera with Coleoptera (64.21%). Considering the geographic location and the extension of the vegetation macrogroups in Madagascar, the entomological data result unevenly distributed. Current Protected Areas' (PAs) network covers about the 70% of the total of the collecting localities for the nine insect orders considered, even though some, such as Trichoptera, Odonata, and Neuroptera seem significantly less protected than others. However, the possible new PAs planned for Madagascar could greatly increase in the future the protection level for all 9 insect orders analyzed, especially for Neuroptera, Odonata and Lepidoptera. A percentage of 82.3% of the whole sampling localities falls inside the PAs themselves or within 1000 m from their borders. A similar pattern is observed for the road network: the 62.9% of the localities fall at least at 1000 m from a road, with no sampling localities observed further than 10 km from a road; statistically significant clusters were observed in evaluating these biases, coinciding with major towns or PAs

Autonomous Observations in Antarctica with AMICA

The Antarctic Multiband Infrared Camera (AMICA) is a double channel camera operating in the 2-28 micron infrared domain (KLMNQ bands) that will allow to characterize and exploit the exceptional advantages for Astronomy, expected from Dome C in Antarctica. The development of the camera control system is at its final stage. After the investigation of appropriate solutions against the critical environment, a reliable instrumentation has been developed. It is currently being integrated and tested to ensure the correct execution of automatic operations. Once it will be mounted on the International Robotic Antarctic Infrared Telescope (IRAIT), AMICA and its equipment will contribute to the accomplishment of a fully autonomous observatory.Comment: 12 pages, 4 figures, Advances in Astronomy Journal, Special Issue "Robotic Astronomy", Accepted 11 February 201

Electromechanical modelling of a new class of nanocomposite cement-based sensors for structural health monitoring

This work focuses on the analysis of a new nanocomposite cement-based sensor (carbon nanotube cement-based sensor), for applications in vibration-based structural health monitoring of civil engineering structures. The sensor is constituted of a cement paste doped with multi-walled carbon nanotubes, so that mechanical deformations produce a measurable change of the electrical resistance. Prior work of some of the authors has addressed the fabrication process, dynamic behaviour and implementation to full-scale structural components. Here, we investigate the effectiveness of a linear lumped-circuit electromechanical model, in which dynamic sensing is associated with a strain-dependent modulation of the internal resistance. Salient circuit parameters are identified from a series of experiments where the distance between the electrodes is parametrically varied. Experimental results indicate that the lumped-circuit model is capable of accurately predicting the step response to a voltage input and its steady-state response to a harmonic uniaxial deformation. Importantly, the model is successful in anticipating the presence of a superharmonic component in sensor’s output