4,231 research outputs found
Brillouin-Raman mapping of natural fibers with spectral moment analysis
This is the author accepted manuscript. The final version is available from the Optical Society of America via the DOI in this record.Brillouin spectroscopy has emerged as a novel analytical tool for biophotonic research and applications. It operates on a microscopic scale and in the GHz spectral range, providing a new spatial and frequency window for the analysis of the structure and elasticity of materials. Here we investigate spectral moments calculation as a means of analysing Brillouin and Raman spectra, providing rapid access to peak intensity and frequency shift, with robust application to fast scanning measurements. This work demonstrates the potential of the method, especially in the case of micro-structured samples, typical of bio-medical applications.COST (European Cooperation in Science and Technology
MIVIS image geocoding experience on merging position attitude system data and public domain GPS stream (ASI-GeoDAF)
The use of airborne scanners involves geo-referencing problems, which are difficult because of the need to know
the exact platform position and attitude for each scan line. The errors of the onboard navigation system are normally
corrected using ground control point on the image. This post-processing correction procedure is too long
in case of multiple flight campaigns, and besides it implies the need to have available 1:10000 orthophotoimages
or maps in digital format. To optimize the above procedure a new method to correct MIVIS navigational
data in the post-processing phase has been implemented. The procedure takes into consideration the GPS stream
in Rinex format of common knowledge and findable on the web, acquired at the ground stations of the Geodetic
Data Archiving Facilities provided by ASI. The application of this correction entails the assumption that the
environmental variables affecting both onboard and geodetic GPS equally affect the position measurements. The
airborne data correction was carried out merging the two data sets (onboard and ground station GPS) to achieve
a more precise aircraft trajectory. The present study compares the geo-coded images obtained by means of the
two post-processing methods
Image analysis applied to Brillouin images of tissue-mimicking collagen gelatins
This is the final version. Available on open access from Optical Society of America via the DOI in this recordBrillouin spectroscopy is an emerging analytical tool in biomedical and biophysical sciences. It probes viscoelasticity through the propagation of thermally induced acoustic waves at gigahertz frequencies. Brillouin light scattering (BLS) measurements have traditionally been performed using multipass Fabry-PĂ©rot interferometers, which have high contrast and resolution, however as they are scanning spectrometers they often require long acquisition times at low laser powers. In the last decade, a new concept of Brillouin spectrometer has emerged, making use of highly angle-dispersive Virtually Imaged Phase Array (VIPA) etalons, which enable fast acquisition times for minimally turbid materials, when high contrast is not imperative. The ability to acquire Brillouin spectra rapidly, together with long term system stability, make this system a viable candidate for use in biomedical applications, especially to probe live cells and tissues. While various methods are being developed to improve system contrast and speed, little work has been published discussing the details of imaging data analysis and spectral processing. Here we present a method that we developed for the automated retrieval of Brillouin line shape parameters from imaging datasets acquired with a dual-stage VIPA Brillouin microscope. We applied this method for the first time to BLS measurements of collagen gelatin hydrogels at different hydration levels and cross-linker concentrations. This work demonstrates that it is possible to obtain the relevant information from Brillouin spectra using software for real-time high-accuracy analysis.Engineering and Physical Sciences Research Council (EPSRC)Cancer Research U
Impulsive rats are less maternal.
Early life environment and maternal care can have long-lasting effects on behavior and physiology. Previously, we found that compared to mother-reared (MR) female rats, rats reared without mothers, siblings, and nest, through artificially rearing (AR), show reduced levels of maternal behavior when they grow up. These effects can be reversed if AR pups are provided with extra “licking-like” tactile stimulation during the preweaning period [Gonzalez et al. [2001] Developmental Psychobiology, 38(1), 11–42]. We also found that AR rats are more action impulsive and have reduced attentional capacities in comparison to their MR siblings [Lovic, Fletcher, & Fleming, in preparation; Lovic & Fleming [2004] Behavioural Brain Research 148: 209–219]. However, it is unknown whether increased impulsivity contributes to reduced levels of maternal behaviors. The purpose of this study was to assess the relationship between impulsivity and maternal behavior in AR and MR rats. Female rats were reared with (MR) or without mothers (AR) and half of the AR rats received additional stroking stimulation. As adults, AR and MR rats were mated and maternal behavior towards their own pups was assessed. In addition, rats were assessed on impulsive action (differential reinforcement of low-rate schedule; DRL-20s). Consistent with previous findings, AR rats were both less maternal and more action impulsive than MR rats. Partial correlations revealed that impulsivity was inversely related to pup licking-impulsive rats were less maternal. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 53: 13–22, 2011.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78484/1/20481_ftp.pd
PANEV: an R package for a pathway-based network visualization
BACKGROUND: During the last decade, with the aim to solve the challenge of post-genomic and transcriptomic data mining, a plethora of tools have been developed to create, edit and analyze metabolic pathways. In particular, when a complex phenomenon is considered, the creation of a network of multiple interconnected pathways of interest could be useful to investigate the underlying biology and ultimately identify functional candidate genes affecting the trait under investigation. RESULTS: PANEV (PAthway NEtwork Visualizer) is an R package set for gene/pathway-based network visualization. Based on information available on KEGG, it visualizes genes within a network of multiple levels (from 1 to n) of interconnected upstream and downstream pathways. The network graph visualization helps to interpret functional profiles of a cluster of genes. CONCLUSIONS: The suite has no species constraints and it is ready to analyze genomic or transcriptomic outcomes. Users need to supply the list of candidate genes, specify the target pathway(s) and the number of interconnected downstream and upstream pathways (levels) required for the investigation. The package is available at https://github.com/vpalombo/PANEV
Spatio-temporal anomalous diffusion in heterogeneous media by NMR
For the first time, the diffusion phase diagram in highly confined colloidal
systems, predicted by Continuous Time Random Walk (CTRW), is experimentally
obtained. Temporal and spatial fractional exponents, and ,
introduced within the framework of CTRW, are simultaneously measured by Pulse
Field Gradient Nuclear Magnetic Resonance technique in samples of micro-beads
dispersed in water. We find that depends on the disorder degree of the
system. Conversely, depends on both bead sizes and magnetic
susceptibility differences within samples. Our findings fully match the CTRW
predictions.Comment: 5 pages, 4 figures, submitted to Phys. Rev. Let
Sentinel lymph node biopsy in porocarcinoma: A case reports
Introduction: Eccrine porocarcinoma (EPC) is a slow-growing carcinoma arising from the eccrine sweat glands. Based on its clinical presentation it can be confused with malignant and benign skin lesions, both. Histological examination is essential to formulate a correct diagnosis. Surgical excision with clear margins is the standard therapeutic approach while the role of sentinel lymph node biopsy (SNLB) remains controversial. Case presentation: The Authors report two cases of EPC of the lower limbs occurred in two women. Patients were treated by wide surgical excision of the lesion and SNLB. 6 months follow-up was disease free for both patients. Conclusion: Although a rare cutaneous tumor, EPC has to be taken into account in the differential diagnosis of malignant skin lesions because of its possible loco-regional aggressiveness and related morbidity. Among the available treatment options, surgical excision is considered the standard approach whereas the role of SNLB is controversial although the Authors discuss a possible usefulness for staging and diagnosis
Genetic variation associated with hypersensitivity to mercury
OBJECTIVES: Very little is known about mechanisms of idiosyncratic sensitivity to the damaging effects of mercury (Hg); however, there is likely a genetic component. The aim of the present study was to search for genetic variation in genes thought to be involved in Hg metabolism and transport in a group of individuals identified as having elevated Hg sensitivity compared to a normal control group. MATERIALS AND METHODS: Survivors of pink disease (PD; infantile acrodynia) are a population of clinically identifiable individuals who are Hg sensitive. In the present study, single nucleotide polymorphisms in genes thought to be involved in Hg transport and metabolism were compared across two groups: (i) PD survivors (n = 25); and (ii) age- and sex-matched healthy controls (n = 25). RESULTS: Analyses revealed significant differences between groups in genotype frequencies for rs662 in the gene encoding paraoxanase 1 (PON1) and rs1801131 in the gene encoding methylenetetrahydrofolate reductase (MTHFR). CONCLUSIONS: We have identified two genetic polymorphisms associated with increased sensitivity to Hg. Genetic variation in MTHFR and PON1 significantly differentiated a group formerly diagnosed with PD (a condition of Hg hypersensitivity) with age- and gender-matched healthy controls
Laboratory activity for a new procedure of MIVIS calibration and relative validation with test data
Remotely sensed data, recorded by means of the MIVIS hyperspectral scanner in the framework of the research
activity of the CNR Institutes IIA-LARA and IMAA, have been calibrated to reflectance values and then quantitatively
compared with ground data. A new procedure for radiometric calibration has been defined by utilizing
the MIVIS test-bench and applying a wider radiance range with respect to the one provided by the manufacturing
company. New calibration curves have been determined and applied in the pre-processing chain. For validation
purpose ground spectra were measured during the campaign by means of a portable spectroradiometer. The
atmospheric correction has been carried out by implementing an IDL procedure to manage MODTRAN4 input
and output cards. MIVIS test data acquired over Passo Corese (Roma) have shown how the new calibration coefficients
significantly improve the radiometric accuracy. In particular, in the VIS spectral region the percentage
error, with respect to a ground truth spectrum, is about half of that occurring if the standard calibration coefficients
are used
Revised NODDI model for diffusion MRI data with multiple b-tensor encodings
This work proposes a revision of the NODDI model to relate brain tissue microstructure to the new generation of diffusion MRI data with
multiple b-tensor encodings. NODDI was developed originally for conventional multi-shell diffusion data acquired with linear tensor encoding
(LTE). While adequate for LTE data, it has been shown to be incompatible with data using spherical tensor encoding (STE). We embed a
different set of assumptions in NODDI, while retaining the tortuosity constraint, to accommodate both LTE and STE data. Experiments with
human data with multiple b-tensor encodings confirm the efficacy of the revision
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