443 research outputs found

    Accuracy in mineral identification: image spectral and spatial resolutions and mineral spectral properties

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    Problems related to airborne hyperspectral image data are reviewed and the requirements for data analysis applied to mineralogical (rocks and soils) interpretation are discussed. The variability of mineral spectral features, including absorption position, shape and depth is considered and interpreted as due to chemical composition, grain size effects and mineral association. It is also shown how this variability can be related to well defined geologic processes. The influence of sensor noise and diffuse atmospheric radiance in classification accuracy is also analyzed

    Characterization of fine metal particles using hyperspectral imaging in automatic WEEE recycling systems

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    Waste from electric and electronic equipment (WEEE) represents the fastest growing waste stream in EU. The large amount and the high variability of electric and electronic products introduced every year in the market make the WEEE recycling process a complex task, especially considering that mechanical processes currently used by recycling companies are not flexible enough. In this context, hyperspectral imaging systems (HSI) can represent an enabling technology able to improve the recycling rates and the quality of the output products. This study shows the preliminary results achieved using a HSI technology in a WEEE recycling pilot plant, for the characterization of fine metal particles derived from WEEE shredding

    Magma dynamics during the 2007 Stromboli eruption (Aeolian Islands. Italy): mineralogical, geochemical and isotopic data

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    After the 6 month-long effusive event of 2002-2003, a new lava effusion occurred at Stromboli between 27 February and 2 April 2007. Despite the different durations, approximately the same volume of magma was emitted in both eruptions, in the order of 107 m3 . A paroxysmal eruption occurred at the summit craters in both the 2002–2003 and 2007 episodes, during which a significant amount of low porphyritic (LP), volatile- rich magma was erupted. In both cases, the paroxysm did not interrupt the lava emission. Here, we present compositional data, including texture, mineralogy, chemistry and Sr and Nd isotope ratios of bulk-rock, groundmass and separated minerals of lavas erupted in 2007, together with chemistry and Sr and Nd isotope composition of the pumices emitted during the 15 March paroxysm. As a whole, the lavas have the same texture and chemistry that characterize the highly porphyritic (HP) products usually erupted at Stromboli during normal Strombolian activity and effusive events. Compared to the previous HP products, the 2007 lavas show minor but systematic mineralogical and isotopic variations which are consistent with a modest increase of the magma supply rate of the volcano. Compositional variations during the entire duration of the event are very modest. Glass chemistry changes in lavas erupted in the second half of March can be explained by theminormixing between the volatile-rich LPmagma rising through the shallowmagmatic systemduring the 15 March paroxysm and the degassed residing HP magma. A first conclusion of this study is that there is no compositional evidence supporting major changes in the magma dynamics of the volcano accompanying the effusive activity, as also suggested for the 2002–2003 event. The activity of Stromboli is controlled by a steady state feeding system in which refilling, mixing, degassing and crystallization at shallow level continuously operate,withmodest oscillations in themagma supply rate. Switching between normal Strombolian and effusive activity is related to periods of relatively more vigorous refilling of the shallow system, leading to progressive pressure increase in the upper conduits associated with only minor compositional variations in the erupted products

    Young at Heart: Pioneering Approaches to Model Nonischaemic Cardiomyopathy with Induced Pluripotent Stem Cells

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    A mere 9 years have passed since the revolutionary report describing the derivation of induced pluripotent stem cells from human fibroblasts and the first in-patient translational use of cells obtained from these stem cells has already been achieved. From the perspectives of clinicians and researchers alike, the promise of induced pluripotent stem cells is alluring if somewhat beguiling. It is now evident that this technology is nascent and many areas for refinement have been identified and need to be considered before induced pluripotent stem cells can be routinely used to stratify, treat and cure patients, and to faithfully model diseases for drug screening purposes. This review specifically addresses the pioneering approaches to improve induced pluripotent stem cell based models of nonischaemic cardiomyopathy

    Lymph node metastases in malignant tumors of the paranasal sinuses: prognostic value and treatment

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    Objective: To assess the frequency of nodal involvement and its prognostic value in malignant tumors of the paranasal sinuses, particularly in maxillary sinus squamous cell carcinoma. Design: Retrospective review. Setting: Tertiary cancer center. Patients: The medical records of 704 consecutive patients surgically treated for malignant tumors of the paranasal sinuses from January 1968 to March 2003 were reviewed. The tumors were staged according to American Joint Committee on Cancer-International Union Against Cancer 2002 classification. Only patients with clinically positive nodes underwent a neck dissection. Main Outcome Measures: Lymph node metastases (at presentation or during follow-up, occurring alone, or with concurrent local recurrence and/or distant metastasis). Also analyzed were local recurrence (occurring alone or with concurrent distant metastasis), distant metastasis (occurring alone), and overall survival. Results: The tumor site was the ethmoid sinus in 305 cases and maxillary sinus in 399 cases. At baseline, 5 patients (1.6%) in the ethmoid sinus group and 33 (8.3%) in the maxillary sinus group presented with positive nodes (P<.001); during follow-up, nodal recurrences (alone or simultaneous with T and/or M recurrence) occurred in 15 and 51 patients, respectively, and the corresponding 5-year incidence estimates were 4.3% and 12.5% (P=.001). The highest incidence of node metastases was found in maxillary sinus squamous cell carcinoma, particularly in T2 tumors. Five-year overall survival estimates were 45.3% for patients with N0 tumors and 0% for those with N+ (N1, N2, or N3) ethmoid sinus tumors, and 50.6% and 16.8%, respectively, for patients with maxillary sinus tumors. Conclusions: Lymph node metastases are a poor prognostic factor for patients with malignant tumors of the paranasal sinuses. The incidence of these metastases is low, particularly in ethmoid sinus tumors. A prophylactic treatment of the neck in patients with N0 tumors (surgery or radiotherapy) might be considered in T2 squamous cell carcinoma of the maxillary sinus and in undifferentiated carcinoma of the ethmoid sinus. ©2008 American Medical Association. All rights reserved

    Context-dependent preferences in starlings: linking ecology, foraging and choice

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    Foraging animals typically encounter opportunities that they either pursue or skip, but occasionally meet several alternatives simultaneously. Behavioural ecologists predict preferences using absolute properties of each option, while decision theorists focus on relative evaluations at the time of choice. We use European starlings (Sturnus vulgaris) to integrate ecological reasoning with decision models, linking and testing hypotheses for value acquisition and choice mechanism. We hypothesise that options' values depend jointly on absolute attributes, learning context, and subject's state. In simultaneous choices, preference could result either from comparing subjective values using deliberation time, or from processing each alternative independently, without relative comparisons. The combination of the value acquisition hypothesis and independent processing at choice time has been called the Sequential Choice Model. We test this model with options equated in absolute properties to exclude the possibility of preference being built at the time of choice. Starlings learned to obtain food by responding to four stimuli in two contexts. In context [AB], they encountered options A5 or B10 in random alternation; in context [CD], they met C10 or D20. Delay to food is denoted, in seconds, by the suffixes. Observed latency to respond (Li) to each option alone (our measure of value) ranked thus: LA≈LC<LB<<LD, consistently with value being sensitive to both delay and learning context. We then introduced simultaneous presentations of A5 vs. C10 and B10 vs. C10, using latencies in no-choice tests to predict sign and strength of preference in pairings. Starlings preferred A5 over C10 and C10 over B10. There was no detectable evaluation time, and preference magnitude was predictable from latency differentials. This implies that value reflects learning rather than choice context, that preferences are not constructed by relative judgements at the time of choice, and that mechanisms adapted for sequential decisions are effective to predict choice behaviour.This work was supported by Biotechnology and Biological Sciences Research Council (BBSRC) Grant BB/G007144/1 to AK www.bbsrc.ac.uk; TM was supported by a Doctoral Grant from the Portuguese Foundation for Science and Technology (FCT) www.fct.pt/index.phtml.en. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    The anti-microbial peptide (Lin-SB056-1)2-K reduces pro-inflammatory cytokine release through interaction with Pseudomonas aeruginosa lipopolysaccharide

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    The ability of many anti-microbial peptides (AMPs) to modulate the host immune response has highlighted their possible therapeutic use to reduce uncontrolled inflammation during chronic infections. In the present study, we examined the anti-inflammatory potential of the semi-synthetic peptide lin-SB056-1 and its dendrimeric derivative (lin-SB056-1)2-K, which were previously found to have anti-microbial activity against Pseudomonas aeruginosa in in vivo-like models mimicking the challenging environment of chronically infected lungs (i.e., artificial sputum medium and 3-D lung mucosa model). The dendrimeric derivative exerted a stronger anti-inflammatory activity than its monomeric counterpart towards lung epithelial-and macrophage-cell lines stimulated with P. aeruginosa lipopolysaccharide (LPS), based on a marked decrease (up to 80%) in the LPS-induced production of different pro-inflammatory cytokines (i.e., IL-1β, IL-6 and IL-8). Accordingly, (lin-SB056-1)2-K exhibited a stronger LPS-binding affinity than its monomeric counterpart, thereby suggesting a role of peptide/LPS neutralizing interactions in the observed anti-inflammatory effect. Along with the anti-bacterial and anti-biofilm properties, the anti-inflammatory activity of (lin-SB056-1)2-K broadens its therapeutic potential in the context of chronic (biofilm-associated) infections

    miR-34a Promotes Vascular Smooth Muscle Cell Calcification by Downregulating SIRT1 (Sirtuin 1) and Axl (AXL Receptor Tyrosine Kinase).

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    Objective- Vascular calcification (VC) is age dependent and a risk factor for cardiovascular and all-cause mortality. VC involves the senescence-induced transdifferentiation of vascular smooth muscle cells (SMCs) toward an osteochondrogenic lineage resulting in arterial wall mineralization. miR-34a increases with age in aortas and induces vascular SMC senescence through the modulation of its target SIRT1 (sirtuin 1). In this study, we aimed to investigate whether miR-34a regulates VC. Approach and Results- We found that miR-34a and Runx2 (Runt-related transcription factor 2) expression correlates in young and old mice. Mir34a &lt;sup&gt;+/+&lt;/sup&gt; and Mir34a &lt;sup&gt;-/-&lt;/sup&gt; mice were treated with vitamin D, and calcium quantification revealed that Mir34a deficiency reduces soft tissue and aorta medial calcification and the upregulation of the VC Sox9 (SRY [sex-determining region Y]-box 9) and Runx2 and the senescence p16 and p21 markers. In this model, miR-34a upregulation was transient and preceded aorta mineralization. Mir34a &lt;sup&gt;-/-&lt;/sup&gt; SMCs were less prone to undergo senescence and under osteogenic conditions deposited less calcium compared with Mir34a &lt;sup&gt;+/+&lt;/sup&gt; cells. Furthermore, unlike in Mir34a &lt;sup&gt;+/+&lt;/sup&gt; SMC, the known VC inhibitors SIRT1 and Axl (AXL receptor tyrosine kinase) were only partially downregulated in calcifying Mir34a &lt;sup&gt;-/-&lt;/sup&gt; SMC. Strikingly, constitutive miR-34a overexpression to senescence-like levels in human aortic SMCs increased calcium deposition and enhanced Axl and SIRT1 decrease during calcification. Notably, we also showed that miR-34a directly decreased Axl expression in human aortic SMC, and restoration of its levels partially rescued miR-34a-dependent growth arrest. Conclusions- miR-34a promotes VC via vascular SMC mineralization by inhibiting cell proliferation and inducing senescence through direct Axl and SIRT1 downregulation, respectively. This miRNA could be a good therapeutic target for the treatment of VC
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