183 research outputs found
You Won the Battle. What about the War? A Model of Competition between Proprietary and Open Source Software
Although open source software has recently attracted a relevant body of economic literature, a formal treatment of the process of com- petition with its proprietary counterpart is still missing. Starting from an epidemic model of innovation di?usion, we try to ?ll this gap. We propose a model where the two competing technologies depend on dif- ferent factors, each one speci?c to its own mode of production (prof- its and developersā motivations respectively), together with network e?ects and switching costs. As the speed of di?usion of these tech- nologies is crucial for the ?nal outcome, we endogenize the parame- ter in?uencing it across the population of adopters. We ?nd that an asymptotically stable equilibrium where both technologies coexist can always be present and, when the propagation coe?cient is endogenous, it coexists with winnerātakeāall solutions. Furthermore, an increase in the level of the switching costs for one technology increases the num- ber of its adopters, while reducing the number of the other one. If the negative network e?ects increase for one of the two technologies, then the equilibrium level of users of that technology decrease.Increasing returns; Open-source software; Technological competition; Technology di?usion
Sociodemographic determinants of knowledge on the figure of radiologist: results of a survey in large university hospital
Introduction
Despite overlaying an irreplaceable role as a key diagnostic tool in modern medicine, the role of radiologist still appears to be unclear to patients.
Methods We conducted a survey in outpatient clinic of Radiological Sciences Department of the University Hospital āA. Gemelliā in Rome, aiming to assess how correct patients identify the figure of the radiologist. The patients were interviewed by the trained physician using structured questionnaire.
Results We included the number of 259 patients. Majority were female 63.3%, most were 60-69 years old (24.3%), have finished second grade secondary school (35.1%) and were subjected to magnetic resonance (28.6%) while the least were subjected to chest X-ray (8.1%). Only 38.7% answered correctly to question No 1 āWho performed your examination?ā, and only 30.9% correctly identified the radiologist as a person interpreting the exam (question No 2 āWho is going to interpret your radiological examination?ā). Overall, 16.8% responded correctly to the both questions. Significantly less patients with primary school (OR: 0.18, CI 95% 0.06-0.49) and first grade secondary school (OR: 0.37, CI 95% 0.18-0.75) correctly addressed the question No 1 in compare to those with second grade secondary school. The first grade secondary education (OR: 0.43, CI 95% 0.20-0.92) was inversely associated with correct answer to question No 2. Patients with primary education were significantly less prone to give both correct answers (OR: 0.12, CI 95% 0.02-0.60).
Conclusion We report insufficient knowledge among patients on radiologistās role in healthcare system. The level of knowledge is associated with level of education
Electronic transport, ionic activation energy and trapping phenomena in a polymer-hybrid halide perovskite composite
Abstract The exploitation of methylammonium lead iodide perovskite-polymer composites is a promising strategy for the preparation of photoactive thin layers for solar cells. The preparation of these composites is a simple fabrication method with improved moisture stability when compared to that of pristine perovskite films. To deepen the understanding of the charge transport properties of these films, we investigated charge carrier mobility, traps, and ion migration. For this purpose, we applied a combinatory measurement approach that proves how such composites can still retain an ambipolar charge transport nature and the same mobility values of the related perovskite. Furthermore, thermally stimulated current measurements revealed that the polymer influenced the creation of additional defects during film formation without affecting charge mobility. Finally, impedance spectroscopy measurements suggested the addition of starch may hinder ion migration, which would require larger activation energies to move ions in composite films. These results pave the way for new strategies of polymer-assisted perovskite film development
Correlation between MYC gene rearrangement and MYC protein expression suggests that MYC regulation is more complex than previously known
Since its discovery in the 1970's, MYC oncoprotein has been continuing to fascinate the scientific world and there is a growing interest in the role of MYC in the genesis and prognosis of cancer.
Initially MYC was identified as the cellular homologue of the MC29 transforming avian retrovirus. Shortly hereafter, additional related sequences were identified, suggesting that MYC might be part of a larger family of genes.
The constellation of MYC effects on genes involved in proliferation has led to the concept of MYC-driven lymphomas, that include Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), and lymphomas that share morphologic features of DLBCL and BL, officially termed B-cell lymphoma, unclassifiable, with features intermediate between DLBCL and BL (BCLU). Other lymphomas showing MYC over-expression comprises Plasmablastic lymphoma and Plasmacytoma, Double hit/triple hit lymphomas and Anaplastic lymphomas Kinase-positive Large B-cell Lymphoma.
MYC aberrations can be detected by standard cytogenetics, interphase fluorescence in situ hybridization (FISH), comparative genomic hybridization and most recently immunohistochemistry. By comparing expression profiles of MYC gene rearrangement and MYC protein expression has came up that MYC gene rearrangements do not necessarily correlate with MYC protein expression. In fact, by applying immunoistochemistry, the frequency of MYC protein expression appears much higher than what is detected by FISH standard method. Therefore, nowadays the key problem in the hematopathology field is to define the clinical impact of the double-expressor lymphoma status. The updated World Health Organization (WHO) of tumours of hematopoietic and lymphoid tissues asses that the status of double or triple lymphoma should rely only on molecular biology findings and not on immunohistochemistry results
Human osteoarthritic chondrocytes exposed to extremely low-frequency electromagnetic fields (ELF) and therapeutic application of musically modulated electromagnetic fields (TAMMEF) systems: a comparative study.
Osteoarthritis (OA) is the most common joint disease, characterized by matrix
degradation and changes in chondrocyte morphology and metabolism. Literature
reported that electromagnetic fields (EMFs) can produce benefits in OA patients,
even if EMFs mechanism of action is debated. Human osteoarthritic chondrocytes
isolated from femoral heads were cultured in vitro in bidimensional (2-D) flasks
and in three-dimensional (3-D) alginate beads to mimic closely cartilage
environment in vivo. Cells were exposed 30 min/day for 2 weeks to extremely
low-frequency electromagnetic field (ELF) with fixed frequency (100 Hz) and to
therapeutic application of musically modulated electromagnetic field (TAMMEF)
with variable frequencies, intensities, and waveforms. Cell viability was
measured at days 7 and 14, while healthy-cell density, heavily vacuolized (hv)
cell density, and cluster density were measured by light microscopy only for 3-D
cultures after treatments. Cell morphology was observed for 2-D and 3-D cultures
by transmission electron microscopy (TEM). Chondrocyte exposure to TAMMEF
enhances cell viability at days 7 and 14 compared to ELF. Light microscopy
analysis showed that TAMMEF enhances healthy-cell density, reduces hv-cell
density and clustering, compared to ELF. Furthermore, TEM analysis showed
different morphology for 2-D (fibroblast-like) and 3-D (rounded shape) cultures,
confirming light microscopy results. In conclusion, EMFs are effective and safe
for OA chondrocytes. TAMMEF can positively interfere with OA chondrocytes
representing an innovative non-pharmacological approach to treat OA
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Metallothioneins as dynamic markers for brain disease in lysosomal disorders
Objective: To facilitate development of novel disease-modifying therapies for lysosomal storage disorder (LSDs) characterized by nervous system involvement such as metachromatic leukodystrophy (MLD), molecular markers for monitoring disease progression and therapeutic response are needed. To this end, we sought to identify blood transcripts associated with the progression of MLD. Methods: Genome-wide expression analysis was performed in primary T lymphocytes of 24 patients with MLD compared to 24 age- and sex-matched healthy controls. Genes associated with MLD were identified, confirmed on a quantitative polymerase chain reaction platform, and replicated in an independent patient cohort. mRNA and protein expression of the prioritized gene family of metallothioneins was evaluated in postmortem patient brains and in mouse models representing 6 other LSDs. Metallothionein expression during disease progression and in response to specific treatment was evaluated in 1 of the tested LSD mouse models. Finally, a set of in vitro studies was planned to dissect the biological functions exerted by this class of molecules. Results: Metallothionein genes were significantly overexpressed in T lymphocytes and brain of patients with MLD and generally marked nervous tissue damage in the LSDs here evaluated. Overexpression of metallothioneins correlated with measures of disease progression in mice and patients, whereas their levels decreased in mice upon therapeutic treatment. In vitro studies indicated that metallothionein expression is regulated in response to oxidative stress and inflammation, which are biochemical hallmarks of lysosomal storage diseases. Interpretation Metallothioneins are potential markers of neurologic disease processes and treatment response in LSDs
Review Article Isoprostanes and 4-Hydroxy-2-nonenal: Markers or Mediators of Disease? Focus on Rett Syndrome as a Model of Autism Spectrum Disorder
Lipid peroxidation, a process known to induce oxidative damage to key cellular components, has been implicated in several diseases. Following three decades of explorations mainly on in vitro models reproducible in the laboratories, lipid peroxidation has become increasingly relevant for the interpretation of a wide range of pathophysiological mechanisms in the clinical setting. This cumulative effort has led to the identification of several lipid peroxidation end-products meeting the needs of the in vivo evaluation. Among these different molecules, isoprostanes and 4-hydroxy-2-nonenal protein adducts appear to be particularly interesting. This review shows how specific oxidation products, deriving from polyunsaturated fatty acids precursors, are strictly related to the clinical manifestations and the natural history of Rett syndrome, a genetically determined neurodevelopmental pathology, currently classified among the autism spectrum disorders. In our experience, Rett syndrome offers a unique setting for physicians, biologists, and chemists to explore the borders of the lipid mediators concept
Defective proteasome biogenesis into skin fibroblasts isolated from Rett syndrome subjects with {MeCP}2 non-sense mutations
Rett Syndrome (RTT) is a rare X-linked neurodevelopmental disorder which affects about 1: 10000 live births. In >95% of subjects RTT is caused by a mutation in Methyl-CpG binding protein-2 (MECP2) gene, which encodes for a transcription regulator with pleiotropic genetic/epigenetic activities. The molecular mechanisms underscoring the phenotypic alteration of RTT are largely unknown and this has impaired the development of therapeutic approaches to alleviate signs and symptoms during disease progression. A defective proteasome biogenesis into two skin primary fibroblasts isolated from RTT subjects harbouring non-sense (early-truncating) MeCP2 mutations (i.e., R190fs and R255X) is herewith reported. Proteasome is the proteolytic machinery of Ubiquitin Proteasome System (UPS), a pathway of overwhelming relevance for post-mitotic cells metabolism. Molecular, transcription and proteomic analyses indicate that MeCP2 mutations down-regulate the expression of one proteasome subunit, Ī±7, and of two chaperones, PAC1 and PAC2, which bind each other in the earliest step of proteasome biogenesis. Furthermore, this molecular alteration recapitulates in neuron-like SH-SY5Y cells upon silencing of MeCP2 expression, envisaging a general significance of this transcription regulator in proteasome biogenesis
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