Here we use synchrotron tomography to characterise dental vasculature in the oldest known tooth-bearing
sharks, Leonodus carlsi Mader, 1986 and Celtiberina maderi Wang, 1993. Three dimensional reconstruction
of the vascular system and microstructure of both taxa revealed a complex and dense network of canals, including
horizontal, ascending and secondary bifurcated canals, as well as histological features consistent with
an osteodont histotype. However, L. carlsi and C. maderi also exhibit significant morphological differences,
showing Leonodus a typical diplodont tooth morphology with a linguo-labially elongated base, that contrast
with Celtiberina’s teeth that show a single conical cusp curved lingually with a week developed flat base mesio-
distally extended, perhaps reflecting distant relationship. These data are compatible with a pre-Devonian
diversification of the two main tooth types traditionally recognised in Palaeozoic sharks (i.e., “cladodont” vs
“diplodont”). Finally, our data demonstrate that existing dental classification schemes based on styles of vascularisation
are over-simplified, especially when Palaeozoic taxa are considered.
The paper presents plant communities from northern Wedel Jarlsberg Land. 55 species of vascular plants were described in this region. Differentiation of plant communities is discussed as controlled by habitat conditions. Plant succession in intramorainal zones of Renardbreen and Scottbreen has been also considered.
In this paper a review on biometric person identification has been discussed using features from retinal fundus image. Retina recognition is claimed to be the best person identification method among the biometric recognition systems as the retina is practically impossible to forge. It is found to be most stable, reliable and most secure among all other biometric systems. Retina inherits the property of uniqueness and stability. The features used in the recognition process are either blood vessel features or non-blood vessel features. But the vascular pattern is the most prominent feature utilized by most of the researchers for retina based person identification. Processes involved in this authentication system include pre-processing, feature extraction and feature matching. Bifurcation and crossover points are widely used features among the blood vessel features. Non-blood vessel features include luminance, contrast, and corner points etc. This paper summarizes and compares the different retina based authentication system. Researchers have used publicly available databases such as DRIVE, STARE, VARIA, RIDB, ARIA, AFIO, DRIDB, and SiMES for testing their methods. Various quantitative measures such as accuracy, recognition rate, false rejection rate, false acceptance rate, and equal error rate are used to evaluate the performance of different algorithms. DRIVE database provides 100% recognition for most of the methods. Rest of the database the accuracy of recognition is more than 90%.
Spectroscopy has become one of the most used non-invasive methods to detect plant diseases before symptoms are visible. In this study it was possible to characterize the spectral variation in leaves of Solanum lycopersicum L. infected with Fusarium oxysporum during the incubation period. It was also possible to identify the relevant specific wavelengths in the range of 380–1000 nm that can be used as spectral signatures for the detection and discrimination of vascular wilt in S. lycopersicum. It was observed that inoculated tomato plants increased their reflectance in the visible range (Vis) and decreased slowly in the near infrared range (NIR) measured during incubation, showing marked differences with plants subjected to water stress in the Vis/NIR. Additionally, three ranges were found in the spectrum related to infection by F. oxysporum (510–520 nm, 650–670 nm, 700–750 nm). Linear discriminant models on spectral reflectance data were able to differentiate between tomato varieties inoculated with F. oxysporum from healthy ones with accuracies higher than 70% 9 days after inoculation. The results showed the potential of reflectance spectroscopy to discriminate plants inoculated with F. oxysporum from healthy ones as well as those subjected to water stress in the incubation period of the disease.