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The Mars Exploration Rover Opportunity investigated plains at Meridiani Planum, where laminated sedimentary rocks are present. The Opportunity rover's Athena morphological investigation showed microstructures organized in intertwined filaments of microspherules: a texture we have also found on samples of terrestrial (biogenic) stromatolites and other microbialites. We performed a quantitative image analysis to compare images (n=45) of microbialites with the images (n=30) photographed by the rover (corresponding, approximately, to 25,000/15,000 microstructures). Contours were extracted and morphometric indexes were obtained: geometric and algorithmic complexities, entropy, tortuosity, minimum and maximum diameters. Terrestrial and Martian textures present a multifractal aspect. Mean values and confidence intervals from the Martian images overlapped perfectly with those from the terrestrial samples. The probability of this occurring by chance is 1/2 8 , less than p<0.004. Terrestrial abiogenic pseudostromatolites showed a simple fractal structure and different morphometric values from those of the terrestrial biogenic stromatolite images or Martian images with a less ordered texture (p<0.001). Our work shows the presumptive evidence of microbialites in the Martian outcroppings: i.e., the presence of unicellular life on the ancient Mars.

Background: Hereditary non-polyposis colorectal cancer (HNPCC) (Lynch cancer family syndrome I (LCFS1) and II (LCFS2)) is one of the most common hereditary cancer disorders. HNPCC results from dominantly inherited germline mutations in mismatch repair (MMR) genes, leading to genomic instability and cancer. No predictive physical signs of HNPCC are available to date. Aims: Increased complexity in tumour associated vascular growth has been reported. Here, we tested the hypothesis that an increased vascular network complexity is a phenotypic marker for LCFS2. Methods: Fourteen subjects from an LCFS2 kindred (gene carriers, n = 5; non-carriers, n = 9) and 30 controls were examined. Fractal dimension (D) at two scales (D (1-46), and D (1-15), tortuosity (minimum path dimension, Dmin), and relative Lempel-Ziev complexity (L-Z) of the vascular networks from the lower gingival and vestibular oral mucosa were measured. Results: LCFS2 networks exhibited a significantly increased overall complexity at both larger (D (1-46) In the present study, we tested the hypothesis that an increased vascular network complexity is a phenotypic marker for LCFS2. METHODS SubjectsFourteen surviving members from a large Southern Italy LCFS2 kindred (eight males, six females; aged 40.2 (11.7) years (range 26-71)) were examined. Detailed characteristic features of this extensively affected family have been reported previously, including early age of onset of tumours, full details of the pedigree, clinical parameters, increased frequency of CRCs (mainly with proximal location), as well as high occurrence of gastric, endometrial, and multiple primary malignancies.12-14 LCFS2 gene mutation carriers (n = 5) were differentiated from non-carriers (n = 9) using a previously established linkage analysis.15 16 Two of five gene carrier patients had a history of proven cancer at the time of examination. Given the specific end point of the present study, family members without genetic testing available were excluded (four males, one female; aged 16.2 (5.7) years (range 10-18)). Thirty genetically unrelated age and sex matched healthy controls (17 males, 13 females; aged 40.0 (10.5) years (range 26-71)) were also enrolled. None of the examined subjects had known inherited connective tissue or vascular diseases. No cases of CRC were present in the family history or pedigrees of controls. Approval by the research ethics committee and informed consent for examination and photographic documentation were obtained. Oral vascular network analysisThe lower gingival and vestibular oral mucosa was chosen as the study area due to its high vasculature pattern visibility and easy accessibility. A 704 mm 2 size (32622 mm) area of the lower gingival and vestibular oral mucosa was photographed for each subject (1:1 ratio, orthogonal projection). All photographs were taken by a single operator using a Yashica Dental Eye photocamera with an automated on-axis flashbulb and a 55 mm f 1:4 Yashica lens (Yashica-Kyocera Co., Kyoto, Japan). Kodak Elite Chrome 100 ISO/21 DIN fil...

The only extraterrestrial life detection experiments ever conducted were the three which were components of the 1976 Viking Mission to Mars. Of these, only the Labeled Release experiment obtained a clearly positive response. In this experiment 14 C radiolabeled nutrient was added to the Mars soil samples. Active soils exhibited rapid, substantial gas release. The gas was probably CO 2 and, possibly, other radiocarbon-containing gases. We have applied complexity analysis to the Viking LR data. Measures of mathematical complexity permit deep analysis of data structure along continua including signal vs. noise, entropy vs.negentropy, periodicity vs. aperiodicity, order vs. disorder etc. We have employed seven complexity variables, all derived from LR data, to show that Viking LR active responses can be distinguished from controls via cluster analysis and other multivariate techniques. Furthermore, Martian LR active response data cluster with known biological time series while the control data cluster with purely physical measures. We conclude that the complexity pattern seen in active experiments strongly suggests biology while the different pattern in the control responses is more likely to be non-biological. Control responses that exhibit relatively low initial order rapidly devolve into near-random noise, while the active experiments exhibit higher initial order which decays only slowly. This suggests a robust biological response. These analyses support the interpretation that the Viking LR experiment did detect extant microbial life on Mars.

Our data suggest that eyes with ON and NAION seem to have increased vascular complexity in the optic nerve head, manifested as an increase in fractal dimension.

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The Mars Exploration Rover Spirit investigated plains at Gusev crater, where sedimentary rocks are present. The Spirit rover's Athena morphological investigation shows microstructures organized in intertwined filaments of microspherules: a texture we have also found on samples of terrestrial stromatolites and other microbialites. We performed a quantitative image analysis to compare 45 microbialites samplings with 50 rover's ones (approximately 25,000/20,000 microstructures). Contours were extracted and morphometric indexes obtained: geometric and algorithmic complexities, entropy, tortuosity, minimum and maximum diameters. Terrestrial and Martian textures resulted multifractals, while terrestrial abiogenic minerals showed a simple fractal structure. Mean values and confidence intervals from the Martian images overlapped perfectly with those from terrestrial samples. The probability of this occurring by chance was less than 1/2 8 , p<0.004. Our work show the presumptive evidence of microbialites in the Martian outcroppings explored by "Spirit", confirming our previous results concerning the Martian outcroppings explored by Opportunity at Meridiani Planum: unicellular life was widespread on the ancient Mars.

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