Multispectral imaging of Mars: ISM results

Summary Multispectral imaging of planets opens a new class of studies of atmospheric and surface signatures. With ISM experiment on board Phobos, the first IR multispectral imaging of Mars from space was achieved. In viem of the Future Omega experiment on board Mars 94, we present here a sample of data and results (and problems) which can be achieved by studying spectral reflectance. Paper presented at the V Cosmic Physics National Conference, S. Miniato, November 27–30, 1990.     

In vivo mapping of functional domains and axonal connectivity in cat visual cortex using magnetic resonance imaging

Noninvasive cognitive neuroimaging studies based on functional magnetic resonance imaging (fMRI) are of ever-increasing importance for basic and clinical neurosciences. The explanatory power of fMRI could be greatly expanded, however, if the pattern of the neuronal circuitry underlying functional activation could be made visible in an equally noninvasive manner. In this study, blood oxygenation level-dependent (BOLD)-based fMRI and diffusion tensor imaging (DTI) were performed in the same cat visual cortex, and the foci of fMRI activation utilized as seeding points for 3D DTI fiber reconstruction algorithms, thus providing the map of the axonal circuitry underlying visual information processing. The methods developed in this study will lay the foundation for in vivo neuroanatomy and the ability for noninvasive longitudinal studies of brain development.     

Investigating directed cortical interactions in time-resolved fMRI data using vector autoregressive modeling and Granger causality mapping

We present a framework aimed to reveal directed interactions of activated brain areas using time-resolved fMRI and vector autoregressive (VAR) modeling in the context of Granger causality. After describing the underlying mathematical concepts, we present simulations helping to characterize the conditions under which VAR modeling and Granger causality can reveal directed interactions from fluctuations in BOLD-like signal time courses. We apply the proposed approach to a dynamic sensorimotor mapping paradigm. In an event-related fMRI experiment, subjects performed a visuomotor mapping task for which the mapping of two stimuli (“faces” vs “houses”) to two responses (“left” or “right”) alternated periodically between the two possible mappings. Besides expected activity in sensory and motor areas, a fronto-parietal network was found to be active during presentation of a cue indicating a change in the stimulus-response (S-R) mapping. The observed network includes the superior parietal lobule and premotor areas. These areas might be involved in setting up and maintaining stimulus-response associations. The Granger causality analysis revealed a directed influence exerted by the left lateral prefrontal cortex and premotor areas on the left posterior parietal cortex.     

Quiet-time solar-wind ionic composition

Summary The ISEE-B EGD solar-wind plasma experiment often observes heavy ions in the solar wind. Selecting two periods of quiet solar wind with no particles observed backstreaming from the Earth’s bow-shock, we show that different ion species follow similar trends in terms of changes in the bulk speed and changes in the particle number density. In particular, quiet-solar-wind ionic abundances in these two cases are (relative to H⁺)⁴He²⁺=(1”5)·10⁻²,³He²⁺=1.5·10⁻⁴, 0⁺⁶=(3”15)·10⁻⁴, O⁺⁷=3·10⁻⁴, Si=1·10⁻⁴, Fe=0.5·10⁻⁴. We show that, if⁴He²⁺ abundance increases, the same occurs for the Si, O⁺⁷ and O⁺⁶ abundances. Finally the O⁺⁶ density fluctuations seem to be anticorrelated with⁴He²⁺ density fluctuations.

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Riassunto L’esperimento sul plasma del vento solare dell’EGD ISEE-B spesso osserva ioni pesanti nel vento solare. Scegliendo due periodi di vento solare quieto in cui non si osservano particelle che rifluiscono dall’onda d’urto della Terra, si mostra che differenti specie di ioni hanno andamenti simili delle variazioni della velocità complessiva e dei cambiamenti nella densità numerica delle particelle. In particolare le abbondanze ioniche nei periodi di vento solare quieto sono in questi due casi (relativamente all’H⁺)⁴He²⁺=(1”5)·10⁻²,³He²⁺=1.5·10⁻⁴, O⁺⁶=(3”15)·10⁻⁴, O⁺⁷=3·10⁻⁴, Si=1·10⁻⁴, Fe=0.5·10⁻⁴. Si mostra che, se l’abbondanza dell’⁴He²⁺ cresce, lo stesso avviene dalle abbondanze di Si, O⁺⁷ e O⁺⁶. Infine, le fluttuazioni della densità dell’O⁺⁶ sembrano essere anticorrelate a quelle dell’⁴He²⁺.

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Резюме При проведении плазменного эксперимента ISEE-B EGD часто обнаруживают тяжелые ионы в солнечном ветре. Отбирая два периода спокойного солнечного ветра, мы показываем, что различные ионные компоненты подчиняются аналогичным тенденциям в изменениях объемной скорости и в изменениях плотности числа частиц. При особенно спокойном солнечном ветре ионные концентрации в указанных двух случаях составляют (по отношению к H⁺)⁴He²⁺=(1”5)·10⁻²,³He²⁺=1.5·10⁻⁴, O⁺⁶=(3”15)·10⁻⁴, O⁺⁷=3·10⁻⁴, Si=1·10⁻⁴, Fe=0.5·10⁻⁴. Мы показываем, что если распространенность⁴He²⁺ увеличивается, то имеет место увеличение распространенностей Si, O⁺⁷ и O⁺⁶. Флуктуации плотности O⁺⁶, по-видимому, антикоррелируют с флуктуациями плотности⁴He²⁺.

     

Electrochemical detection of miRNA-222 by use of a magnetic bead-based bioassay

MicroRNAs (miRNAs, miRs) are naturally occurring small RNAs (approximately 22 nucleotides in length) that have critical functions in a variety of biological processes, including tumorigenesis. They are an important target for detection technology for future medical diagnostics. In this paper we report an electrochemical method for miRNA detection based on paramagnetic beads and enzyme amplification. In particular, miR 222 was chosen as model sequence, because of its involvement in brain, lung, and liver cancers. The proposed bioassay is based on biotinylated DNA capture probes immobilized on streptavidin-coated paramagnetic beads. Total RNA was extracted from the cell sample, enriched for small RNA, biotinylated, and then hybridized with the capture probe on the beads. The beads were then incubated with streptavidin–alkaline phosphatase and exposed to the appropriate enzymatic substrate. The product of the enzymatic reaction was electrochemically monitored. The assay was finally tested with a compact microfluidic device which enables multiplexed analysis of eight different samples with a detection limit of 7 pmol L^?1 and RSD?=?15 %. RNA samples from non-small-cell lung cancer and glioblastoma cell lines were also analyzed.     

Clarkson–McCarthy Inequalities for l p -Spaces of Operators in Schatten Ideals

In this paper we obtain generalized Clarkson–McCarthy inequalities for spaces l _q (S ^p ) of operators from Schatten ideals S ^p . We show that all Clarkson–McCarthy type inequalities are, in fact, some estimates on the norms of operators acting on the spaces l _q (S ^p ) or from one such space into another. We also extend some inequalities for partitioned operators and for Cartesian decomposition of operators.     

Optimizing ICA in fMRI using information on spatial regularities of the sources

Spatial independent component analysis (ICA) is a well-established technique for multivariate analysis of functional magnetic resonance imaging (fMRI) data. It blindly extracts spatiotemporal patterns of neural activity from functional measurements by seeking for sources that are maximally independent. Additional information on one or more sources (e.g., spatial regularity) is often available; however, it is not considered while looking for independent components. In the present work, we propose a new ICA algorithm based on the optimization of an objective function that accounts for both independence and other information on the sources or on the mixing model in a very general fashion. In particular, we apply this approach to fMRI data analysis and illustrate, by means of simulations, how inclusion of a spatial regularity term helps to recover the sources more effectively than with conventional ICA. The improvement is especially evident in high noise situations. Furthermore we employ the same approach on data sets from a complex mental imagery experiment, showing that consistency and physiological plausibility of relatively weak components are improved.     

Comparison of essential oil components and in vitro anticancer activity in wild and cultivated Salvia verbenaca

The objectives of our research were to study the chemical composition and the in vitro anticancer effect of the essential oil of Salvia verbenaca growing in natural sites in comparison with those of cultivated (Sc) plants. The oil from wild (Sw) S. verbenaca presented hexadecanoic acid (23.1%) as the main constituent, while the oil from Sc plants contained high quantities of hexahydrofarnesyl acetone (9.7%), scarce in the natural oil (0.7%). The growth-inhibitory and proapoptotic effects of the essential oils from Sw and Sc S. verbenaca were evaluated in the human melanoma cell line M14, testing cell vitality, cell membrane integrity, genomic DNA fragmentation and caspase-3 activity. Both the essential oils were able to inhibit the growth of the cancer cells examined inducing also apoptotic cell death, but the essential oil from cultivated samples exhibited the major effects.     

A study on the essential oil of Ferulago campestris: How much does extraction method influence the oil composition?

The essential oil of different parts of Ferulago campestris (Bess.) collected in Sicily has been extracted by microwave-assisted hydrodistillation (MAHD) and by classic hydrodistillation (HD). A comparative qualitative-quantitative study on the composition of the oils was carried out. A total of 100 compounds were identified in the oils obtained by MAHD, whereas 88 compounds characterized the HD oils. The most prominent components were, in all different parts of F. campestris and in both extraction methods, 2,4,5-trimethylbenzaldehyde and 2,4,6-trimethylbenzaldehyde isomers; the latter was not previously found. The attempt to evaluate where the oil components are located in all parts of the plant was carried out by means of a kinetic study. Then, electron microscopy observation on the different parts before and after MAHD and HD was performed.     

Analysis of essential oils from Scutellaria orientalis ssp. alpina and S. utriculata by GC and GC-MS

The chemical composition of the essential oils obtained from aerial parts of Scutellaria orientalis L. ssp. alpina (Boiss.) O. Schwarz and S. utriculata Labill. growing wild in Lebanon, were analyzed by GC and GC-MS. In S. orientalis ssp. alpina, strongly characterized by sesquiterpenes (41.2%) and particularly sesquiterpene hydrocarbons (31.7%), hexahydrofarnesylacetone (11.7%) was recognized as the main constituent, together with hexadecanoic acid (7.6%), caryophyllene (7.4%), caryophyllene oxide (6.8%), 4-vinylguaiacol (5.4%) and germacrene D (5.4%). S. utriculata oil was instead constituted above all by monoterpenes (42.2%), particularly oxygen containing monoterpenes (39.9%), and in this oil the main compounds were linalool (20.1%), 4-vinyl guaiacol (15.5%), alpha-terpineol (8.9%), (E)-nerolidol (8.9%) and geraniol (8.2%).