Partial least squares discriminant analysis: A dimensionality reduction method to classify hyperspectral data

The recent development of more sophisticated spectroscopic methods allows acquisition of high dimensional datasets from which valuable information may be extracted using multivariate statistical analyses, such as dimensionality reduction and automatic classification (supervised and unsupervised). In this work, a supervised classification through a partial least squares discriminant analysis (PLS-DA) is performed on the hy- perspectral data. The obtained results are compared with those obtained by the most commonly used classification approaches

Partial least squares discriminant analysis: A dimensionality reduction method to classify hyperspectral data

The recent development of more sophisticated spectroscopic methods allows acqui- sition of high dimensional datasets from which valuable information may be extracted using multivariate statistical analyses, such as dimensionality reduction and automatic classification (supervised and unsupervised). In this work, a supervised classification through a partial least squares discriminant analysis (PLS-DA) is performed on the hy- perspectral data. The obtained results are compared with those obtained by the most commonly used classification approaches

Reciprocal regulation of the bile acid-activated receptor FXR and the interferon-γ-STAT-1 pathway in macrophages

AbstractNuclear receptors are a family of ligand regulated factors that exert homeostatic functions at the interface between metabolic and immune function. The farnesoid X receptor (FXR) is a bile acid sensor expressed in immune cells such as macrophages where it exerts counter-regulatory effects. FXR deficient mice demonstrate disregulated immune response. Expression of FXR is down-regulated in inflamed tissues but the mechanism that leads to FXR down-regulation by inflammatory mediators is unknown. In the present study we have investigated the effect of inflammation-related cytokines on macrophages and demonstrated that INFγ is a potent inhibitor of FXR gene expression/function in macrophages. STAT1 silencing and over-expression experiments demonstrated that FXR repression is mediated by INFγ dependent activation of STAT1. Since IFNγ is a potent activator of STAT1 we searched for STAT1 binding sites in the human FXR genomic and identified a region of the human FXR gene between the second and third exon that contains three hypothetical STAT1 binding sites. RAW 264.7 transiently transfected with an FXR genomic reporter construct which contained the three STAT binding sites responded to IFNγ with a robust decrease in the reporter activity, demonstrating the potent modulation of FXR transcription by IFNγ. Chromatin immunoprecipitation assay revealed that this region was immunoprecipitated following treatment of macrophage cell lines and supershift assay demonstrated that STAT1 was able to bind one of three identified sites. In summary, these results suggest that IFNγ induced STAT1 homodimers modulate the transcriptional repression of FXR gene in macrophages during inflammation-related cytokines

Fast Ultrahigh-Density Writing of Low Conductivity Patterns on Semiconducting Polymers

The exceptional interest in improving the limitations of data storage, molecular electronics, and optoelectronics has promoted the development of an ever increasing number of techniques used to pattern polymers at micro and nanoscale. Most of them rely on Atomic Force Microscopy to thermally or electrostatically induce mass transport, thereby creating topographic features. Here we show that the mechanical interaction of the tip of the Atomic Force Microscope with the surface of a class of conjugate polymers produces a local increase of molecular disorder, inducing a localized lowering of the semiconductor conductivity, not associated to detectable modifications in the surface topography. This phenomenon allows for the swift production of low conductivity patterns on the polymer surface at an unprecedented speed exceeding 20 $\mu m s^{-1}$; paths have a resolution in the order of the tip size (20 nm) and are detected by a Conducting-Atomic Force Microscopy tip in the conductivity maps.Comment: 22 pages, 6 figures, published in Nature Communications as Article (8 pages

Application of nuclear magnectic resonance (NRM) to study of grape dehydration cv. bombino

[SPA] Actualmente Italia ha experimentado un importante crecimiento en la producción de vinos dulces o de postre de calidad. Asimismo, se han modificado las técnicas de secado de sistemas tradicionales a sistemas más tecnificados. El incremento de la demanda por una mejor calidad de los productos, ha provocado la investigación y desarrollo de técnicas de medida y evaluación no destructiva. La técnica de deshidratación consiste en un túnel de secado dotado de ventiladores que trabajan en régimen de aspiración donde se controlan las variables de velocidad de aire, temperatura y humedad relativa. Se seleccionaron 100 bayas numeradas y se dispusieron en el interior del túnel a una velocidad de aire de 1,5 m/s, una temperatura de 20ºC y una humedad relativa 45-50%. El tiempo de secado fue de 13 días hasta alcanzar aproximadamente el 30% de peso perdido. Se tomaron diferentes imágenes de resonancia magnética (RMI) a lo largo del proceso de secado, pudiendo visualizar el movimiento del agua durante el proceso de deshidratación, que ocurre desde las capas más superficiales hacia el centro geométrico de la baya. [ENG] Now days, Italy has experimented an important development in the production of quality sweet wines or dessert wines. In this way, it has modified the systems of drying techniques. The increase of the need of a better quality of products, has caused the research and the development of non destructive measurement and evaluation techniques. The dehydration technique consists of drying tunnel with funs working in a regime of aspiration where the air variation, temperature and relative humidity are controlled.100 berries numbered were selected and they were set into the tunnel at an air speed of 1,5 m/s, a temperature of 20ºC and the relative humidity 45-50%. The time of drying was 13 days until reaching 30% of weight loss. It takes different nuclear magnetic imagining during grape drying. We can observe the water movement during the dehydration process which happens from the superficial tissue below the skin towards to the centre by concentric circles.Trabajo de investigación financiado por el Ministerio de Agricultura Italiano (MUVON Project). Al programa Sócrates /Erasmus de la UPCT la ayuda financiera para la estancia de Alejandro Tomás en Italia

Hydrogen sulphide induces μ opioid receptor-dependent analgesia in a rodent model of visceral pain

<p>Abstract</p> <p>Background</p> <p>Hydrogen sulphide (H₂S) is a gaseous neuro-mediator that exerts analgesic effects in rodent models of visceral pain by activating K_ATPchannels. A body of evidence support the notion that K_ATPchannels interact with endogenous opioids. Whether H₂S-induced analgesia involves opioid receptors is unknown.</p> <p>Methods</p> <p>The perception of painful sensation induced by colorectal distension (CRD) in conscious rats was measured by assessing the abdominal withdrawal reflex. The contribution of opioid receptors to H₂S-induced analgesia was investigated by administering rats with selective μ, κ and δ opioid receptor antagonists and antisenses. To investigate whether H₂S causes μ opioid receptor (MOR) transactivation, the neuronal like cells SKNMCs were challenged with H₂S in the presence of MOR agonist (DAMGO) or antagonist (CTAP). MOR activation and phosphorylation, its association to β arrestin and internalization were measured.</p> <p>Results</p> <p>H₂S exerted a potent analgesic effects on CRD-induced pain. H₂S-induced analgesia required the activation of the opioid system. By pharmacological and molecular analyses, a robust inhibition of H₂S-induced analgesia was observed in response to central administration of CTAP and MOR antisense, while κ and δ receptors were less involved. H₂S caused MOR transactivation and internalization in SKNMCs by a mechanism that required AKT phosphorylation. MOR transactivation was inhibited by LY294002, a PI3K inhibitor, and glibenclamide, a K_ATPchannels blocker.</p> <p>Conclusions</p> <p>This study provides pharmacological and molecular evidence that antinociception exerted by H₂S in a rodent model of visceral pain is modulated by the transactivation of MOR. This observation provides support for development of new pharmacological approaches to visceral pain.</p

Dirac Equation-Based Formulation for the Quantum Conductivity in 2D-Nanomaterials

bstract: Starting from the four component-Dirac equation for free, ballistic electrons with finite mass, driven by a constant d.c. field, we derive a basic model of scalar quantum conductivity, capable of yielding simple analytic forms, also in the presence of magnetic and polarization effects. The classical Drude conductivity is recovered as a limit case. A quantum-mechanical evaluation is provided for parabolic and linear dispersion, as in graphene, recovering currently used expressions as particular cases. Numerical values are compared with the ones from the literature in the case of graphene under d.c. applied field

The Bile Acid Sensor FXR Protects against Dyslipidemia and Aortic Plaques Development Induced by the HIV Protease Inhibitor Ritonavir in Mice

Although human immunodeficiency virus (HIV)–related morbidity and mortality rates in patients treated with a combination of high active antiretroviral therapy (HAART) have declined, significant metabolic/vascular adverse effects associated with the long term use of HIV protease inhibitors (PIs) have emerged as a significant side effect. Here we illustrate that targeting the bile acid sensor farnesoid X receptor (FXR) protects against dyslipidemia and vascular injury induced HIV-PIs in rodents. mice with gemfibrozil, a PPARα agonist. FXR activation counter-regulated induction of expression/activity of CD36 caused by HIV-PIs in circulating monocytes and aortic plaques. In macrophages cell lines, CDCA attenuated CD36 induction and uptake of acetylated LDL caused by ritonavir. Natural and synthetic FXR ligands reduced the nuclear translocation of SREBP1c caused by ritonavir.Activation of the bile acid sensor FXR protects against dyslipidemia and atherosclerotic caused by ritonavir, a widely used HIV PI. From a mechanistic stand point it appears that besides reducing the liver expression of genes involved in fatty acid synthesis, FXR activation counter-regulates the expression/activity of CD36 on monocytes. FXR ligands might hold promise in the treatment dyslipidemia induced by ritonavir

Coupling of Integrated Waveguide and Optomechanic Cavity for Microwave Phonon Excitation in Si Nanobeams

The availability of high quality manufacturing for optical micro/nano patterned cavities paves the way to the development of scalable circuits and devices based on optomechanical (OM) interaction of sound and light in extremely small volumes. In this contribution, we propose a new study on OM cavities that can lead to precise control of their coupling with closely integrated waveguides, a necessary condition to enhance mode excitation and wave energy trapping, opening the possibility for many potential applications in wave guiding, filtering, confinement, and sensing. Moreover, in this way the need for bulky experimental setups and/or optical fiber coupling/excitation is avoided. At the same time, quality factors of mechanical and optical modes resonating in the cavity are optimized, together with their OM coupling coefficients: high confinement of both excitations is a prerequisite to enable their acousto-optic (AO) interaction. To this aim, the transversal size of the cavity has been parabolically tapered, with the additional benefit of separating the cavity and the integrated waveguide far from the coupling region. The finite-element method has been used to perform full-wave analysis, and an accurate discussion about the simulation setup needed to properly describe optical scattering and radiation has been provide

Probiotics Modulate Intestinal Expression of Nuclear Receptor and Provide Counter-Regulatory Signals to Inflammation-Driven Adipose Tissue Activation

BACKGROUND: Adipocytes from mesenteric white adipose tissue amplify the inflammatory response and participate in inflammation-driven immune dysfunction in Crohn's disease by releasing proinflammatory mediators. Peroxisome proliferator-activated receptors (PPAR)-α and -γ, pregnane x receptor (PXR), farnesoid x receptor (FXR) and liver x-receptor (LXR) are ligand-activated nuclear receptor that provide counter-regulatory signals to dysregulated immunity and modulates adipose tissue. AIMS: To investigate the expression and function of nuclear receptors in intestinal and adipose tissues in a rodent model of colitis and mesenteric fat from Crohn's patients and to investigate their modulation by probiotics. METHODS: Colitis was induced by TNBS administration. Mice were administered vehicle or VSL#3, daily for 10 days. Abdominal fat explants obtained at surgery from five Crohn's disease patients and five patients with colon cancer were cultured with VSL#3 medium. RESULTS: Probiotic administration attenuated development of signs and symptoms of colitis, reduced colonic expression of TNFα, IL-6 and IFNγ and reserved colonic downregulation of PPARγ, PXR and FXR caused by TNBS. Mesenteric fat depots isolated from TNBS-treated animals had increased expression of inflammatory mediators along with PPARγ, FXR, leptin and adiponectin. These changes were prevented by VSL#3. Creeping fat and mesenteric adipose tissue from Crohn's patients showed a differential expression of PPARγ and FXR with both tissue expressing high levels of leptin. Exposure of these tissues to VSL#3 medium abrogates leptin release. CONCLUSIONS: Mesenteric adipose tissue from rodent colitis and Crohn's disease is metabolically active and shows inflammation-driven regulation of PPARγ, FXR and leptin. Probiotics correct the inflammation-driven metabolic dysfunction