408 research outputs found
The value of traditional rural landscape and nature protected areas in tourism demand: A study on agritourists' preferences
This study focuses on how traditional rural landscape and proximity to a Natura 2000 Site of Community Importance (SCI) might influence consumers\u2019 choice of an agritourism farm for a weekend stay. Data were collected in Umbria region\u2019s (Italy) agritourism farms in 2014 by interviewing 160 tourists. Results from a discrete choice experiment reveal that the most important feature affecting the interviewees\u2019 propensity to pay a premium price to stay in an agritourism farm is the well-preserved traditional landscape (willingness to pay 32.32\u20ac/night for two people), followed by the availability of a swimming pool (willingness to pay 20.95\u20ac/night for two people), the proximity to a historical village (willingness to pay 18.37\u20ac/night for two people) and, the location in a Natura 2000 SCI (willingness to pay 13.57\u20ac/night for two people). Furthermore, the results underline how the preservation of the traditional landscape and protection of the surrounding environment play a strategic role in developing agritourism and provide economic benefits to local communities
Peptide selfâassembled nanostructures: from models to therapeutic peptides
: Self-assembly is the most suitable approach to obtaining peptide-based materials on the nano- and mesoscopic scales. Applications span from peptide drugs for personalized therapy to light harvesting and electron conductive media for solar energy production and bioelectronics, respectively. In this study, we will discuss the self-assembly of selected model and bioactive peptides, in particular reviewing our recent work on the formation of peptide architectures of nano- and mesoscopic size in solution and on solid substrates. The hierarchical and cooperative characters of peptide self-assembly will be highlighted, focusing on the structural and dynamical properties of the peptide building blocks and on the nature of the intermolecular interactions driving the aggregation phenomena in a given environment. These results will pave the way for the understanding of the still-debated mechanism of action of an antimicrobial peptide (trichogin GA IV) and the pharmacokinetic properties of a peptide drug (semaglutide) currently in use for the therapy of type-II diabetes
Fog-Driven Context-Aware Architecture for Node Discovery and Energy Saving Strategy for Internet of Things Environments
The consolidation of the Fog Computing paradigm and the ever-increasing diffusion of Internet of Things (IoT) and smart objects are paving the way toward new integrated solutions to efficiently provide services via short-mid range wireless connectivity. Being the most of the nodes mobile, the node discovery process assumes a crucial role for service seekers and providers, especially in IoT-fog environments where most of the devices run on battery. This paper proposes an original model and a fog-driven architecture for efficient node discovery in IoT environments. Our novel architecture exploits the location awareness provided by the fog paradigm to significantly reduce the power drain of the default baseline IoT discovery process. To this purpose, we propose a deterministic and competitive adaptive strategy to dynamically adjust our energy-saving techniques by deciding when to switch BLE interfaces ON/OFF based on the expected frequency of node approaching. Finally, the paper presents a thorough performance assessment that confirms the applicability of the proposed solution in several different applications scenarios. This evaluation aims also to highlight the impact of the nodes' dynamic arrival on discovery process performance
Liver infection and COVID-19: the electron microscopy proof and revision of the literature
OBJECTIVE: COVID-19, the newly emerging infectious disease, has been associated with acute liver injury, often related to progression to severe pneumonia. The association between moderate-severe liver injury and more severe clinical course of COVID-19 has suggested that liver injury is prevalent in severe than in mild cases of COVID-19, while no difference in liver involvement has been reported between survivors and non-survivors. The spectrum of liver involvement during COVID-19 ranges from an asymptomatic elevation of liver enzymes to severe hepatitis. Only rarely, cases with acute hepatitis have been reported in the absence of respiratory symptoms. Both epithelial and biliary cells possess the angiotensin-converting enzyme-2 receptors that SARS-CoV-2 uses to be internalized. However, to our knowledge, no ultrastructural identification of the virus in liver cells has been reported to date. Here we provide evidence of SARS-CoV-2 in the liver of two patients, a 34-year-old woman and a 60-year-old man with COVID-19.PATIENTS AND METHODS: We investigated two patients with COVID-19 showing several virions within cytoplasmic vacuoles of cholangiocytes and in endothelial cells of hepatic sinusoids. In both patients, we performed histological and ultrastructural examinations by liver biopsy. After two months, both patients were free of symptoms, and the SARS-CoV-2 infection had resolved.RESULTS: Liver biopsy histological and ultrastructural examination showed liver injury and several virions within cytoplasmic vacuoles of cholangiocytes and in endothelial cells of hepatic sinusoids.CONCLUSIONS: Although most studies in COVID-19 have been focused on the lungs, recently, cholestatic liver pathology has been introduced in the spectrum of pathological changes related to COVID-19. To the best of our knowledge, those presented in this paper are the first images of hepatic SARS-CoV-2 infected liver cells. Our findings suggest a role for cholangiocytes and biliary structures in the COVID-19
High-quality CMOS compatible n-type SiGe parabolic quantum wells for intersubband photonics at 2.5-5 THz
A parabolic potential that confines charge carriers along the growth direction of quantum wells semiconductor systems is characterized by a single resonance frequency, associated to intersubband transitions. Motivated by fascinating quantum optics applications leveraging on this property, we use the technologically relevant SiGe material system to design, grow, and characterize n-type doped parabolic quantum wells realized by continuously grading Ge-rich Si1-x Ge x alloys, deposited on silicon wafers. An extensive structural analysis highlights the capability of the ultra-high-vacuum chemical vapor deposition technique here used to precisely control the quadratic confining potential and the target doping profile. The absorption spectrum, measured by means of Fourier transform infrared spectroscopy, revealed a single peak with a full width at half maximum at low and room temperature of about 2 and 5 meV, respectively, associated to degenerate intersubband transitions. The energy of the absorption resonance scales with the inverse of the well width, covering the 2.5-5 THz spectral range, and is almost independent of temperature and doping, as predicted for a parabolic confining potential. On the basis of these results, we discuss the perspective observation of THz strong light-matter coupling in this silicon compatible material system, leveraging on intersubband transitions embedded in all-semiconductor microcavities
A Toolchain Architecture for Condition Monitoring Using the Eclipse Arrowhead Framework
Condition Monitoring is one of the most critical applications of the Internet of Things (IoT) within the context of Industry 4.0. Current deployments typically present interoperability and management issues, requiring human intervention along the engineering process of the systems; in addition, the fragmentation of the IoT landscape, and the adoption of poor architectural solutions often make it difficult to integrate third-party devices in a seamless way. In this paper, we tackle these issues by proposing a tool-driven architecture that supports heterogeneous sensor management through well-established interoperability solutions for the IoT domain, i.e. the Eclipse Arrowhead framework and the recent Web of Things (WoT) standard released by the W3C working group. We deploy the architecture in a real Structural Health Monitoring (SHM) scenario, which validates each developed tool and demonstrates the increased automation derived from their combined usage
A global optimization approach applied to structural dynamic updating
In this paper, the application of stochastic global optimization tech- niques, in particular the GlobalSearch and MultiStart solvers from MatLabÂź, to improve the updating of a structural dynamic model, are presented. For com- parative purposes, the efficiency of these global methods relatively to the local search method previously used in a Finite Element Model Updating program is evaluated. The obtained solutions showed that the GlobalSearch and MultiStart solvers are able to achieve a better solution than the local solver previously used, in the updating of a structural dynamic model. The results show also that the GlobalSearch solver is more efficient than the MultiStart, since requires less computational effort to obtain the global solution.Fundação para a CiĂȘncia e a Tecnologia (FCT
Chromosomal clustering of genes controlled by the aire transcription factor
Autoimmune regulator (aire) is a transcription factor that controls the self-reactivity of the T cell repertoire. Although previous results indicate that it exerts this function in part by promoting ectopic expression of a battery of peripheral-tissue antigens in epithelial cells of the thymic medulla, recent data argue for additional roles in negative selection of thymocytes by medullary cells. As one approach to exploring such roles, we performed computational analyses of microarray data on medullary RNA transcripts from aire-deficient versus wild-type mice, focusing on the genomic localization of aire-controlled genes. Our results highlight this molecule's transcriptional activating and silencing roles and reveal a significant degree of clustering of its target genes. On a local scale, aire-regulated clusters appeared punctate, with aire-controlled and aire-independent genes often being interspersed. This pattern suggests that aire's action may not be a simple reflection of the wide action of a chromatin remodeling enzyme. Analysis of the identity of certain of the clustered genes was evocative of aire's potential roles in antigen presentation and the coordination of intrathymic cell migration: for example, major histocompatibility complex class I and class II gene products and certain chemokine genes are targets of aire-regulated transcription
Novel NPM1 exon 5 mutations and gene fusions leading to aberrant cytoplasmic nucleophosmin in AML
Nucleophosmin (NPM1) mutations in acute myeloid leukemia (AML) affect exon 12, but also sporadically affect exons 9 and 11, causing changes at the protein C-terminal end (tryptophan loss, nuclear export signal [NES] motif creation) that lead to aberrant cytoplasmic NPM1 (NPM1c+), detectable by immunohistochemistry. Combining immunohistochemistry and molecular analyses in 929 patients with AML, we found nonâexon 12 NPM1 mutations in 5 (1.3%) of 387 NPM1c+ cases. Besides mutations in exons 9 (n = 1) and 11 (n = 1), novel exon 5 mutations were discovered (n = 3). Another exon 5 mutation was identified in an additional 141 patients with AML selected for wild-type NPM1 exon 12. Three NPM1 rearrangements (NPM1/RPP30, NPM1/SETBP1, NPM1/CCDC28A) were detected and characterized among 13 979 AML samples screened by cytogenetic/fluorescence in situ hybridization and RNA sequencing. Functional studies demonstrated that in AML cases, new NPM1 proteins harbored an efficient extra NES, either newly created or already present in the fusion partner, ensuring its cytoplasmic accumulation. Our findings support NPM1 cytoplasmic relocation as critical for leukemogenesis and reinforce the role of immunohistochemistry in predicting AML-associated NPM1 genetic lesions. This study highlights the need to develop new assays for molecular diagnosis and monitoring of NPM1-mutated AML
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