1,487 research outputs found
Firm Capabilities, Competition and Industrial Policies in a History-Friendly Model of the Computer Industry
In this paper, we explore some problems that industrial policy faces in industries characterized by dynamic increasing returns on the basis of a 'history friendly model' of the evolution of the computer industry. How does policy affect industry structure over the course of industry evolution? Is the timing of the intervention important? Do policy interventions have indirect and perhaps unintended consequences on different markets at different times? We focus on two sets of policies: antitrust and interventions aiming at supporting the entry of new forms in the industry. The results of our simulations show that, if strong dynamic increasing returns are operative, both through technological capabilities and through customer tendency to stick with a brand, there is little that antitrust and entry policy could have done to avert the rise of a dominant firm in mainframes. On the other hand, if the customer lock in effect had been smaller, either by chance or through policies that discouraged efforts of firms to lock in their customers, the situation might have been somewhat different. In the first place, even in the absence of antitrust or entry encouraging policies, market concentration would have been lower, albeit a dominant firm would emerge anyhow. Second, antitrust and entry encouraging policies would have been more effective in assuring that concentration would decrease. The leading firm would continue to dominate the market, but its relative power would be reduced. © Elsevier Science B.V
Towards pocket-sized genomic analyses: cross-platform benchmark of multi-organism genomic data indexing and alignment
The current socio-economic situation as well as international objectives set by the United Nation (2030 Sustainable Agenda) underline the urgency of low-cost and environmental-friendly computational alternatives. Moreover, in recent years the bioinformatic community has shown renewed interest for Raspberry Pi (RPi) application in teaching and research projects. In the context of the BioVRPi project - which aims to develop and offer a low-cost, stable and tested bioinformatic environment - we propose an exploratory cross-platform benchmarking of multi-organism genomic analyses. The benchmark of indexing and alignment processes was carried out on the following devices: RPi 4 (Raspberry Pi OS 04-04-2022) RAM 8GB HDD storage, laptop (MacOS Big Sur v11.2.3) Intel Core i5 2GHz quad-core processor RAM 16GB SSD, and desktop (Ubuntu 20.04.4 LTS) Intel Core i7 3GHz octa-core processor RAM 32GB HDD storage. Performance assessment was evaluated on SARS-CoV-2 virus, Escherichia coli and Caenorhabditis elegans genome sequences (respective RefSeq accessions: GCF_009858895.2, GCF_000005845.2, GCF_000002985.6) since they present different degrees of genomic complexity: virus, bacterium, and nematode. To minimize variability and possible biases due to sequencing technologies used, sample reads were generated in silico from their respective reference genomes using ART Illumina v2.5.8 with the following parameters: read length 150, paired end, coverage 30X, mean fragment length 200, standard deviation 10, HiSeqX v2.5 TruSeq built-in profile. Indexing and alignment were performed with 3 alignment tools: BWA v0.7.17-r1188, Bowtie2 v2.4.5, and Minimap2 v2.17, using default parameters and scaling from 1 up to 4 threads. Benchmarking was evaluated using Hyperfine v1.13.0 with a warmup step of 3 simulations and 10 runs for each process. We performed a cross-platform benchmark of multi-organism genomic indexing and short reads alignment to evaluate RPi as a viable alternative to common bioinformatic devices. To assess its performance, we tested some of the most widely used alignment tools on SARS-CoV-2, E. coli and C. elegans genomic data (respective genome sizes: 29.9Kbp, 4.6Mbp, 100.3Mbp). The computational times for indexing and alignment are reported in Table 1. As regards indexing, we observed comparable runtimes among RPi and other platforms using BWA and Bowtie2 for SARS-CoV-2 and E. coli, whereas Minimap2 indexing showed an increase of one order of magnitude in runtimes for RPi. Nonetheless, Minimap2 showed the fastest runtimes for indexing overall. In addition, we found an increase of one order of magnitude in RPi runtimes for C. elegans for all considered tools, even though differences in runtimes across platforms showed to be stable across organisms. As regards the alignment process, we observed consistency in runtimes differences across all organisms and tools. Overall, Minimap2 performances proved to be the fastest whereas Bowtie2 displayed poor performances across all platforms, exacerbating its inefficiency on RPi. Even though BWA seems to work more efficiently on RPi than on desktop for SARS-COV-2 data, desktop and laptop showed better performances on more complex organisms as expected. Benchmarking analyses considered multi-threading up to 4 threads, the maximum available on RPi. As regards indexing on Bowtie2, multi-threading proved to be effective for C. elegans data, showing no improvement in runtimes for SARS-CoV-2 and E. coli. Conversely, alignment showed the best performances using multi-threading as expected. In conclusion, RPi showed promising results, proved to be a viable low-cost and environmental-friendly alternative to perform genomic data analysis on different organisms and turned out to be particularly efficient for microorganisms. Further advances and tools optimization for RPi ARM architecture will lead to a greater scalability for complex organisms and will be carried out by the BioVRPi project in future exploratory analyses
Obstructive Sleep Apnea Syndrome (OSAS) treated with orthodontic appliances in children : a new feasible approach
Obstructive Sleep Apnea Syndrome (OSAS) affects up to 4% of the paediatric population and, due to the high risk of cardio-vascular and neurological complications and negative outcomes on the developmental process associated, represents the most serious type of Sleep Disordered Breathing (SDB) and the most challenging for public health.Although the most common treatment for OSAS in childhood is Adenotonsillectomy (AT), this approach is limited by its surgical risks and by a high prevalence of recurrence or partial success, with persistence of signs and symptoms of obstructive apnea.The presence of cranio-facial abnormalities and malocclusion is considered an important risk factor for paediatric OSAS and its recurrence after AT. Children affected by OSAS often present specific oro-facial features such asnarrow maxilla, mandibular retrusion, anterior openbite, bilateral/ monolateral cross bite, that are frequently associated with dysfunctions such as oral breathing and atypical swallowing. Those alterations can represent an anatomical base which can contribute to the development of paediatric OSAS, especially in preschool child aged 3-6 years, when the hyperplasia of adenoids and tonsils is reported to be at its peak with a higher risk for obstruction. The purpose of the present research is to evaluate the possibility that an orthodontic treatment, primary aiming to the treatment of malocclusion and the related dysfunctions, can induce improvement or relief of respiratory nighttime distress, as a secondary effect. The sample consisted of 5 children affected by OSAS, 3 female and 2 male, average aged 4.5 years, who have never undergone AT or have had a recurrence of sign and symptoms 1 year after AT.All patients presented narrow maxilla, associated with monolateral/ bilateral crossbite and or anterior openbite. The patients underwent orthodontic treatment performed with an elastodontic appliance, which is a removable oral device made of PVC and widely used in children aged less than 6 years. The following variables were evaluated in each patient at the beginning (T0) and after 1 year (T2) of orthodontic treatment:occlusal parameters; Sleep Clinical Score (SCS); Night time poligraphic parameters: Snoring, Apnea/Hypopnea Index (AHI) andOswestry Disability Index (ODI).Four out of 5 patients showed high compliance to the orthodontic treatment and improved their occlusal relationship. In those patients also AHI and ODI index improved as well as the SCS score, revealing a reduction of sign and symptoms of OSAS. The only patient who did not improve his occlusal and respiratory findings also showed poor compliance to the orthodontic treatment. The study suggest that the treatment of malocclusion might produce improvements in sign and symptoms of OSAS in children aged 3-6 years and that preformed elastodontc appliances are a feasible therapeutic tool for this purpose
Generalized aggressive periodontitis in prepubertal age: description and comparison of two cases.
Aggressive periodontitis is a rare form of periodontal disease and it can involve both the deciduous dentition and the permanent one. It causes a rapid loss of periodontal attachment. The paper aims to describe two cases of severe generalized prepubertal periodontitis: the first child doesn't suffer from neither systemic diseases nor alteration of functionality of polymorphonuclear and periodontal disease involved both his deciduous dentition and the first permanent molars. The second child had a deficiency of functionality of polymorphonuclear but periodontal disease involved only primary dentition thanks to his immediate improvement of home dental hygiene. This comparison shows the importance of early diagnosis and especially of optimal dental oral hygiene. Infant healthcare professionals, as pediatric dentists and pediatricians, should have the necessary knowledge for early and correct diagnosis and clinical management of disease
Mobility and stability of large vacancy and vacancy-copper clusters in iron: An atomistic kinetic Monte Carlo study
The formation of Cu-rich precipitates under irradiation is a major cause for changes in the mechanical response to load of reactor pressure vessel steels. In previous works, it has been shown that the mecha- nism under which precipitation occurs is governed by diffusion of vacancy-copper (VCu) complexes, also in the absence of irradiation. Coarse-grained computer models (such as object kinetic Monte Carlo) aimed at simulating irradiation processes in model alloys or steels should therefore explicitly include the mobil- ity of Cu precipitates, as a consequence of vacancy hops at their surface. For this purpose, in this work we calculate diffusion coefficients and lifetimes for a large variety of VCu complexes. We use an innovative atomistic model, where vacancy migration energies are calculated with little approximations, taking into account all effects of static relaxation and long-range chemical interaction as predicted by an interatomic potential. Our results show that, contrary to what intuition might suggest, saturation in vacancies tend toslow down the transport of Cu atoms.Fil: Castin, N.. Centre d’Etudes de l’énergie NuclĂ©aire; BĂ©lgicaFil: Pascuet, Maria Ines Magdalena. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Malerba, L.. Centre d’Etudes de l’énergie NuclĂ©aire; BĂ©lgic
Public policies and changing boundaries of firms in a “history-friendly” model of the co-evolution of the computer and semiconductor industries
In this paper, we explore the effects of alternative policies, ranging from antitrust to public procurement, open standards, information diffusion and basic research support on the dynamics of two vertically related industries in changing and uncertain technological and market environments. The two industries are a system industry and a component industry, and the evolution of these industries is characterized by periods of technological revolutions punctuating periods of relative technological stability and smooth technical progress. We have been inspired by the co-evolution of the computer and component industries from their inceptions to the 1980s. On the basis of that evolution, we have developed a history friendly-model this co-evolution. In sum, this paper has stressed that various types of policies may sometimes have contrasting effects on the industry, mainly on concentration and technical change and innovation. It has also shown that the consequences of policies may spillover from one industry to another, and from one type of firms to another. Policies that aim at a specific industry may provoke major changes in a related industry through the product market, the changing boundaries of firms or knowledge and technological interdependencies. The policy maker has to be aware of that. Finally, a major point of the paper regards the unintended consequences of policies
Iron chromium potential to model high-chromium ferritic alloys
We present an FeÂCr interatomic potential to model high-Cr ferritic alloys.The potential is fitted to thermodynamic and point-defect propertiesobtained from density functional theory (DFT) calculations and experi-ments. The developed potential is also benchmarked against otherpotentials available in literature. It shows particularly good agreementwith the DFT obtained mixing enthalpy of the random alloy, the formationenergy of intermetallics and experimental excess vibrational entropy andphase diagram. In addition, DFT calculated point-defect properties,both interstitial and substitutional, are well reproduced, as is the screwdislocation core structure. As a first validation of the potential, we studythe precipitation hardening of FeÂCr alloys via static simulations of theinteraction between Cr precipitates and screw dislocations. It is concludedthat the description of the dislocation core modification near a precipitatemight have a significant influence on the interaction mechanisms observedin dynamic simulations.Fil: Bonny, G.. No especifĂca;Fil: Pasianot, Roberto Cesar. Universidad Nacional de San MartĂn. Instituto Sabato; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. ComisiĂłn Nacional de EnergĂa AtĂłmica; ArgentinaFil: Terentyev, D.. No especifĂca;Fil: Malerba, L.. No especifĂca
Vertical integration and disintegration of computer firms: a history-friendly model of the coevolution of the computer and semiconductor industries
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