91,398 research outputs found
A Robust Design for Cellular Vehicles of Gold Nanorods for Multimodal Imaging
No full textAuthors Dr. Marisa Benagiano and Prof. Mario Milco D’Elios were not included when this article was originally published. The corrected list of author of this manuscript is: F. Ratto,* S. Centi, C. Avigo, C. Borri, F. Tatini, L. Cavigli, C. Kusmic, B. Lelli, S. Lai, M. Benagiano, M. M. D’Elios, S. Colagrande, F. Faita, L. Menichetti, and R. Pini The affiliation for Dr. Benagiano and Prof. D’Elios is: Department of Experimental and Clinical Medicine University of Florence, Largo Brambilla 3, 50134 Florence, (FI), Italy Ref. [82] was not included in the originally published version of this article. It should be added to the second paragraph on page 7179, which then reads as follows: “More recently, the notion to exploit the natural tropism of cells, such as tumor-associated macrophages,[35–39] T cells,[40,82] mesenchymal stem cells,[41–43] and neural stem cells,[44,45] has begun to emerge as a radical alternative.” Ref. [82] is: G. Baldi, C. Ravagli, M. Comes Franchini, M. M. D’Elios, M. Benagiano, M. Bitossi (Colorobbia Italia S.p.A.) WO 104664, 2015. The Acknowledgements should be corrected to read as follows: “This work was in part supported by the Projects of Tuscan Region “NANOTREAT” and “SYNERGY” and by the ERANET+ Project of Tuscan Region and European Community “LUS BUBBLE”. The authors wish to thank Dr. Daniele Panetta for his expertise in X-ray micro imaging and Dr. Giovanni Baldi of CERICOL Research Center of Colorobbia Group for his expertise and knowledge on cellular nano-engineering.” The authors apologize for any inconvenience or misunderstanding that these errors may have caused. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinhei
A physically based approach to model LAI from MODIS 250 m data in a tropical region
No full textA time series of leaf area index (LAI) has been developed based on 16-day normalized difference vegetation index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) at 250 m resolution (MOD250_LAI). The MOD250_LAI product uses a physical radiative transfer model which establishes a relationship between LAI, fraction of vegetation cover (FVC) and given patterns of surface reflectance, view-illumination conditions and optical properties of vegetation. In situ measurements of LAI and FVC made at 166 plots using hemispherical photography served for calibration of model parameters and validation of modelling results. Optical properties of vegetation cover, summarized by the light extinction coefficient, were computed at the local (pixel) level based on empirical models between ground-measured tree crown architecture at 85 sampling plots and spectral values in Landsat ETM+ bands. Influence of view-illumination conditions on optical properties of canopy was simulated by a view angle geometry model incorporating the solar zenith angle and the sensor viewing angle. The results revealed high compatibility of the produced MOD250-LAI data set with ground truth information and the 30 m resolution Landsat ETM+ LAI estimated using the similar algorithm. The produced MOD250_LAI was also compared with the global MODIS 1000-m LAI product (MOD15A2 LAI). Results show good consistency of the spatial distribution and temporal dynamics between the two LAI products. However, the results also showed that the annual LAI amplitude by the MODI 5A2 product is significantly higher than by the MOD250_LAI. This higher amplitude is caused by a considerable underestimation of the tropical rainforest LAI by the MOD15A2 during the seasonal phases of low leaf production. (C) 2009 Elsevier B.V. All rights reserved.German Research Foundation (DFG
Optical instruments for measuring leaf area index in low vegetation : application in Arctic ecosystems
Get PDFAuthor Posting. © Ecological Society of America, 2005. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecological Applications 15 (2005): 1462–1470, doi:10.1890/03-5354.Leaf area index (LAI) is a powerful diagnostic of plant productivity. Despite the fact that many methods have been developed to quantify LAI, both directly and indirectly, leaf area index remains difficult to quantify accurately, owing to large spatial and temporal variability. The gap-fraction technique is widely used to estimate the LAI indirectly. However, for low-stature vegetation, the gap-fraction sensor either cannot get totally underneath the plant canopy, thereby missing part of the leaf area present, or is too close to the individual leaves of the canopy, which leads to a large distortion of the LAI estimate. We set out to develop a methodology for easy and accurate nondestructive assessment of the variability of LAI in low-stature vegetation. We developed and tested the methodology in an arctic landscape close to Abisko, Sweden.
The LAI of arctic vegetation could be estimated accurately and rapidly by combining field measurements of canopy reflectance (NDVI) and light penetration through the canopy (gap-fraction analysis using a LI-COR LAI-2000). By combining the two methodologies, the limitations of each could be circumvented, and a significantly increased accuracy of the LAI estimates was obtained. The combination of an NDVI sensor for sparser vegetation and a LAI-2000 for denser vegetation could explain 81% of the variance of LAI measured by destructive harvest. We used the method to quantify the spatial variability and the associated uncertainty of leaf area index in a small catchment area.This research was funded by U.S. National Science Foundation
grant DEB0087046
Experimental and numerical study of vibro-impact systems with two-sided constraints
No full textVibro-impact dynamics has been, and still is, the subject of growing interest for its practical and theoretical significance. Many practical engineering problems involve mechanical components or structures repeatedly colliding with one another or with obstacles during their motion. From a theoretical point of view, impact dynamics is highly interesting for the complex nonlinear behaviors and phenomena exhibited by vibro-impact systems, even the simplest. Despite the vibro-impact dynamics has been the subject of intense study, few works deal with the topic resorting to both experimental and numerical analyses. Furthermore, there are still some aspects that, to date, have been little deepened and deserve more attention.
The aim of this Ph.D. thesis is to characterize, in a systematic and transversal way, the nonlinear non-smooth response of vibro-impact systems with two-sided constraints. The study was inspired by the practical problem of large horizontal seismic-induced displacements in base-isolated structures. These displacements can damage the isolation system itself or can lead to pounding with surrounding moat walls or adjacent structures if the available seismic gap is not sufficient.
The problem was studied considering a single-degree-of-freedom (SDOF) system with two-sided deformable and dissipative constraints (bumpers) under harmonic base excitation and resorting to extensive parametric analyses, of both experimental and numerical nature, continuously interacting and feeding each other throughout the doctoral course. Shaking table tests were carried out on a small-scale physical model, using a rich sensor apparatus, and considering different values of gap amplitude, peak table acceleration and different bumpers. The numerical simulations were performed considering a relatively simple model, in which the impact phenomenon was modeled by a viscoelastic law, and using a Matlab code, specifically created for this purpose. This made it possible to carry out extensive parametric investigations. The adoption of a soft impact model allowed to describe the deformation and the recovery of the bumpers, otherwise not observable by resorting to the coefficient of restitution.
The influence of the fundamental parameters which characterize the problem on the system's response was first investigated. The numerical model, despite its relative simplicity, satisfactorily reproduced the experimental results and allowed to extend the range of investigation, compared to the experimental tests. A wide variety of behaviors and phenomena was observed. Different types of primary resonance (without hysteresis, with right or left hysteresis), secondary resonances (without hysteresis, with right or left hysteresis or of non-regular type), non-symmetric responses, multiple impacts, periodic, quasi-periodic and chaotic motion, were highlighted and investigated resorting to different types of representations. The occurrence of the (primary and secondary) grazing phenomenon, and its relationship with some of the observed scenarios, was also highlighted. The transition from a hardening-like to a softening-like behavior was experimentally observed passing from positive to small negative gaps, through the zero-gap configuration.
The study of the scenarios, besides being interesting from a theoretical point of view, highlighted possible issues associated with the occurrence of impact. This enabled to make interesting considerations on vibration control. By properly selecting the bumpers' parameters (gap and mechanical properties), it is possible to guide the system's response to reach specific objectives, avoiding some undesirable scenarios and encouraging others, and thus exploiting the occurrence of impact with beneficial effects. Some indications of optimal design of the bumpers are provided to reduce both the displacement and the acceleration of the mass, compared to the case without obstacles, without possibly reducing the vibration isolation frequency range
Methanofollis formosanus Wu, Chen & Lai, 2005, sp. nov.
No full textMethanofollis formosanus sp. nov. Description of Methanofollis formosanus sp. nov. Methanofollis formosanus (for.mo.sa'nus. N.L. masc. adj. formosanus from Formosa, the beautiful island of Taiwan). Irregularly coccoid cells, non-motile, 1 5-2 0 mmin diameter. Obligately anaerobic cells. Stains Gram-negative. Cell wall has an SDS-sensitive S-layer protein with an Mr of 138 800. Catabolic substrates used include H2/CO2 and formate, but not acetate, methanol, trimethylamine, dimethylamine, ethanol, 2-propanol, iso-butanol, 2-butanol or dimethylamine. Cells are mesophilic and grow at 20- 42°C, with optimal growth at 37°C. Cells grow at pH 5 6- 7-3, with optimal growth atpH 6-6. Cells grow well in 0-4 % NaCl, with optimal growth at 3 % NaCl. Addition ofacetate reduces the lag time and the trace element tungsten greatly promotes cell growth and extends the growth range. No growth is detected in minimal medium. Growth is completely inhibited by chloramphenicol and partly inhibited by tetracycline, but not by ampicillin, penicillin, kanamycin or spectinomycin. The G+C content of DNA of strain ML15T is 58 4 mol%. The type strain is strain ML15T (= OCM 789T = DSM 15483T), isolated from a marine water aquaculture fish pond near Wang-gong, Taiwan.Published as part of Wu, S. - Y., Chen, S. - C. & Lai, M. - C., 2005, Methanofollis formosanus sp. nov., isolated from a fish pond., pp. 837-842 in International Journal of Systematic and Evolutionary Microbiology 55 on page
Empirical evidence on agricultural land-use change in Sardinia (Italy) from GIS-based analysis and a Tobit model
No full textThis paper analyzes the quantitative change in agricultural land uses in
the Sardinian region in the time period the 2000-2006 EAGGF-based part of the Regional Operational Program (2000-2006 ROP-EAGGF) was implemented, in order to assess if, and to what extent, it was effective in
maintaining agricultural land use compared to other signals concerning local development, such as income and urbanization.
The assessment is based on a geographic information system and a Tobit model. The results are a source of important information to address the on-going policies of the 2007-2013 Rural Development Programme, and the question of geographic concentration of investments
Participation of c-FLIP in NLRP3 and AIM2 inflammasome activation
No full textCellular FLICE-inhibitory protein (c-FLIP) is an inhibitor of caspase-8 and is required for macrophage survival. Recent studies have revealed a selective role of caspase-8 in noncanonical IL-1 beta production that is independent of caspase-1 or inflammasome. Here we demonstrated that c-FLIPL is an unexpected contributor to canonical inflammasome activation for the generation of caspase-1 and active IL-1 beta. Hemizygotic deletion of c-FLIP impaired ATP-and monosodium uric acid (MSU)-induced IL-1 beta production in macrophages primed through Toll-like receptors (TLRs). Decreased IL-1 beta expression was attributed to a reduced activation of caspase-1 in c-FLIP hemizygotic cells. In contrast, the production of TNF-alpha was not affected by downregulation in c-FLIP. c-FLIPL interacted with NLRP3 or procaspase-1. c-FLIP is required for the full NLRP3 inflammasome assembly and NLRP3 mitochondrial localization, and c-FLIP is associated with NLRP3 inflammasome. c-FLIP downregulation also reduced AIM2 inflammasome activation. In contrast, c-FLIP inhibited SMAC mimetic-, FasL-, or Dectin-1-induced IL-1 beta generation that is caspase-8-mediated. Our results demonstrate a prominent role of c-FLIPL in the optimal activation of the NLRP3 and AIM2 inflammasomes, and suggest that c-FLIP could be a valid target for treatment of inflammatory diseases caused by over-activation of inflammasomes
Downscaling rice yield simulation at sub-field scale using remotely sensed LAI data
No full textCrop modeling and remote sensing are key tools to gain deeper understanding on cropping system dynamics and, ultimately, to increase the sustainability of agricultural productions. This study presents a system to estimate rice yields at sub-field scale based on the integration of a biophysical model and remotely sensed products. Leaf area index (LAI) data derived from decametric optical imageries (i.e., Landsat-8, Landsat-7 and Sentinel–2A) were assimilated into the WARM rice model via automatic recalibration of crop parameters at a fine spatial resolution (30 m × 30 m), targeting the lowest error between simulated and remotely sensed LAI. The performance of the system was evaluated by comparing simulated yield using default and recalibrated parameters at sub-field scale with yield maps generated by a GPS-equipped harvester. The training dataset included 40 paddy fields in Northern Italy, which were sampled during three cropping seasons, from 2014 to 2016. The assimilation of remotely sensed LAI into model parameters increased the accuracy of the system: MAE and RRMSE were 0.66 t ha-1 [CI: 0.54 t ha-1–0.78 t ha-1] and 13.8% [CI: 11.7%–15.7%], respectively, whereas they were 0.82 t ha-1 [CI: 0.68 t ha-1–0.96 t ha-1) and 15.7% [CI: 14.1%,–17.4%] without assimilation. Moreover, the system allowed to properly reproduce the within-field yield variability, thus laying the basis for possible applications in precision agriculture advisory services
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