330 research outputs found
Enhancing shopping experiences in smart retailing
The retailing market has undergone a paradigm-shift in the last decades, departing from its traditional form of shopping in brick-and-mortar stores towards online shopping and the establishment of shopping malls. As a result, “small” independent retailers operating in urban environments have suffered a substantial reduction of their turnover. This situation could be presumably reversed if retailers were to establish business “alliances” targeting economies of scale and engage themselves in providing innovative digital services. The SMARTBUY ecosystem realizes the concept of a “distributed shopping mall”, which allows retailers to join forces and unite in a large commercial coalition that generates added value for both retailers and customers. Along this line, the SMARTBUY ecosystem offers several novel features: (i) inventory management of centralized products and services, (ii) geo-located marketing of products and services, (iii) location-based search for products offered by neighboring retailers, and (iv) personalized recommendations for purchasing products derived by an innovative recommendation system. SMARTBUY materializes a blended retailing paradigm which combines the benefits of online shopping with the attractiveness of traditional shopping in brick-and-mortar stores. This article provides an overview of the main architectural components and functional aspects of the SMARTBUY ecosystem. Then, it reports the main findings derived from a 12 months-long pilot execution of SMARTBUY across four European cities and discusses the key technology acceptance factors when deploying alike business alliances
Major axes of variation in tree demography across global forests
The future trajectory of global forests is closely intertwined with tree demography, and a major fundamental goal in ecology is to understand the key mechanisms governing spatio‐temporal patterns in tree population dynamics. While previous research has made substantial progress in identifying the mechanisms individually, their relative importance among forests remains unclear mainly due to practical limitations. One approach to overcome these limitations is to group mechanisms according to their shared effects on the variability of tree vital rates and quantify patterns therein. We developed a conceptual and statistical framework (variance partitioning of Bayesian multilevel models) that attributes the variability in tree growth, mortality, and recruitment to variation in species, space, and time, and their interactions – categories we refer to as organising principles (OPs). We applied the framework to data from 21 forest plots covering more than 2.9 million trees of approximately 6500 species. We found that differences among species, the species OP, proved a major source of variability in tree vital rates, explaining 28–33% of demographic variance alone, and 14–17% in interaction with space, totalling 40–43%. Our results support the hypothesis that the range of vital rates is similar across global forests. However, the average variability among species declined with species richness, indicating that diverse forests featured smaller interspecific differences in vital rates. Moreover, decomposing the variance in vital rates into the proposed OPs showed the importance of unexplained variability, which includes individual variation, in tree demography. A focus on how demographic variance is organized in forests can facilitate the construction of more targeted models with clearer expectations of which covariates might drive a vital rate. This study therefore highlights the most promising avenues for future research, both in terms of understanding the relative contributions of groups of mechanisms to forest demography and diversity, and for improving projections of forest ecosystems
Glial Fibrillary Acidic Protein Autoimmunity: A French Cohort Study
Background and ObjectivesTo report the clinical, biological, and imaging features and clinical course of a French cohort of patients with glial fibrillary acidic protein (GFAP) autoantibodies.MethodsWe retrospectively included all patients who tested positive for GFAP antibodies in the CSF by immunohistochemistry and confirmed by cell-based assay using cells expressing human GFAPα since 2017 from 2 French referral centers.ResultsWe identified 46 patients with GFAP antibodies. Median age at onset was 43 years, and 65% were men. Infectious prodromal symptoms were found in 82%. Other autoimmune diseases were found in 22% of patients, and coexisting neural autoantibodies in 11%. Tumors were present in 24%, and T-cell dysfunction in 23%. The most frequent presentation was subacute meningoencephalitis (85%), with cerebellar dysfunction in 57% of cases. Other clinical presentations included myelitis (30%) and visual (35%) and peripheral nervous system involvement (24%). MRI showed perivascular radial enhancement in 32%, periventricular T2 hyperintensity in 41%, brainstem involvement in 31%, leptomeningeal enhancement in 26%, and reversible splenial lesions in 4 cases. A total of 33 of 40 patients had a monophasic course, associated with a good outcome at last follow-up (Rankin Score ≤2: 89%), despite a severe clinical presentation. Adult and pediatric features are similar. Thirty-two patients were treated with immunotherapy. A total of 11/22 patients showed negative conversion of GFAP antibodies.DiscussionGFAP autoimmunity is mainly associated with acute/subacute meningoencephalomyelitis with prodromal symptoms, for which tumors and T-cell dysfunction are frequent triggers. The majority of patients followed a monophasic course with a good outcome
Modulating the photoluminescence of bridged silsesquioxanes incorporating Eu(3+)-complexed n,n '-diureido-2,2 '-bipyridine isomers: application for luminescent solar concentrators
Two new urea-bipyridine derived bridged organosilanes (P5 and P6) have been synthesized and their hydrolysis-condensation under nucleophilic catalysis in the presence of Eu(3+) salts led to luminescent bridged silsesquioxanes (M5-Eu and M6-Eu). An important loading of Eu(3+) (up to 11%(w)) can be obtained for the material based on the 6,6'-isomer. Indeed the photoluminescence properties of these materials, that have been investigated in depth (photoluminescence (PL), quantum yield, lifetimes), show a significantly different complexation mode of the Eu(3+) ions for M6-Eu, compared with M4-Eu (obtained from the already-reported 4,4'-isomer) and M5-Eu. Moreover, M6-Eu exhibits the highest absolute emission quantum yield value (0.18 +/- 0.02) among these three materials. The modification of the sol composition upon the addition of a malonamide derivative led to similar luminescent features but with an increased quantum yield (026 +/- 0.03). In addition, M6-Eu can be processed as thin films by spin-coating on glass substrates, leading to plates coated by a thin layer (similar to 54 nm) of Eu(3+)-containing hybrid silica exhibiting one of the highest emission quantum yields reported so far for films of Eu(3+)-containing hybrids (0.34 +/- 0.03) and an interesting potential as new luminescent solar concentrators (LSCs) with an optical conversion efficiency of similar to 4%. The ratio between the light guided to the film edges and the one emitted by the surface of the film was quantified through the mapping of the intensity of the red pixels (in the RGB color model) from a film image. This quantification enabled a more accurate estimation of the transport losses due to the scattering of the emitted light in the film (0.40), thereby correcting the initial optical conversion efficiency to a value of 1.7%.FCT - PTDC/CTM/101324/2008COMPETEFEDE
Anisotropic diffusion of water molecules in hydroxyapatite nanopores
Funded by EPSRC Grant EP/K000128/1
Validation of standard and alternative satellite ocean-color chlorophyll products off Western Iberia
Chlorophyll a concentration (Chl) product validation off theWestern Iberian coast is here undertaken by directly
comparing remote sensing data with in situ surface reference values. Both standard and recently developed
alternative algorithms are considered for match-up data analysis. The investigated standard products are those
produced by the MERIS (algal 1 and algal 2) and MODIS (OC3M) algorithms. The alternative data products include
those generatedwithin the CoastColour Project and Ocean Color Climate Change Initiative (OC-CCI) funded
by ESA, as well as a neural net model trained with field measurements collected in the Atlantic off Portugal
(MLPATLP). Statistical analyses showed that satellite Chl estimates tend to be larger than in situ reference values.
The study also revealed that a non-uniform Chl distribution in the water column can be a concurring factor to the
documented overestimation tendency when considering larger optical depth match-up stations. Among standard
remote sensing products, MODIS OC3M and MERIS algal 2 yield the best agreement with in situ data. The
performance of MLPATLP highlights the capability of regional solutions to further improve Chl retrieval by accounting
for environmental specificities. Results also demonstrate the relevance of oceanographic regions such
as the Nazaré area to evaluate how complex hydrodynamic conditions can influence the quality of Chl products.This studywas performed in the framework
of HabSpot FCT Project, PTDC/MAR/100348/2008 and European
Space Agency projects DUE CoastColour (ESRIN/AO/1-6141/09/l-EC)
and Climate Change Iniciative — Ocean Color (AO-1/6207/09/I-LG).
The work has been also partially supported by the European Space
Agency within the framework of the MERIS Validation Activities under
contract n. 12595/09/I-OL, and sampling activities benefited from
European projects HERMES (GOCE-CT-2005-511234) and Hermione
(EC contract 226354) support. We would like to thank NASA OBPG for
the MODIS data and ESA Project AOPT-2423 for providing MERIS full
resolution images. Ana C. Brito was funded
by a Portuguese Post-doc grant from FCT (BPD/63017/2009) and by the
Investigador FCT Program (IF/00331/2013). Davide D'Alimonte was
funded by Investigador FCT Program (IF/00541/2013).info:eu-repo/semantics/publishedVersio
High on-off conductance switching ratio in optically-driven self-assembled conjugated molecular systems
A new azobenzene-thiophene molecular switch is designed, synthesized and used
to form self-assembled monolayers (SAM) on gold. An "on/off" conductance ratio
up to 7x1E3 (with an average value of 1.5x1E3) is reported. The "on"
conductance state is clearly identified to the cis isomer of the azobenzene
moiety. The high "on/off" ratio is explained in terms of photo-induced,
configuration-related, changes in the electrode-molecule interface energetics
(changes in the energy position of the molecular orbitals with respect to the
Fermi energy of electrodes) in addition to changes in the tunnel barrier length
(length of the molecules). First principles DFT calculations demonstrate a
better delocalization of the frontier orbitals, as well as a stronger
electronic coupling between the azobenzene moiety and the electrode for the cis
configuration over the trans one. Measured photoionization cross-sections for
the molecules in the SAM are close to the known values for azobenzene
derivatives in solution.Comment: 1 file with main text, figure and suppementary informatio
Response to Comment on “Plant diversity increases with the strength of negative density dependence at the global scale”
Hülsmann and Hartig suggest that ecological mechanisms other than specialized natural enemies or intraspecific competition contribute to our estimates of conspecific negative density dependence (CNDD). To address their concern, we show that our results are not the result of a methodological artifact and present a null-model analysis that demonstrates that our original findings—(i) stronger CNDD at tropical relative to temperate latitudes and (ii) a latitudinal shift in the relationship between CNDD and species abundance—persist even after controlling for other processes that might influence spatial relationships between adults and recruits
Brief Exposure to Sensory Cues Elicits Stimulus-Nonspecific General Sensitization in an Insect
The effect of repeated exposure to sensory stimuli, with or without reward is well known to induce stimulus-specific modifications of behaviour, described as different forms of learning. In recent studies we showed that a brief single pre-exposure to the female-produced sex pheromone or even a predator sound can increase the behavioural and central nervous responses to this pheromone in males of the noctuid moth Spodoptera littoralis. To investigate if this increase in sensitivity might be restricted to the pheromone system or is a form of general sensitization, we studied here if a brief pre-exposure to stimuli of different modalities can reciprocally change behavioural and physiological responses to olfactory and gustatory stimuli. Olfactory and gustatory pre-exposure and subsequent behavioural tests were carried out to reveal possible intra- and cross-modal effects. Attraction to pheromone, monitored with a locomotion compensator, increased after exposure to olfactory and gustatory stimuli. Behavioural responses to sucrose, investigated using the proboscis extension reflex, increased equally after pre-exposure to olfactory and gustatory cues. Pheromone-specific neurons in the brain and antennal gustatory neurons did, however, not change their sensitivity after sucrose exposure. The observed intra- and reciprocal cross-modal effects of pre-exposure may represent a new form of stimulus-nonspecific general sensitization originating from modifications at higher sensory processing levels
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