An agent-based model of product competition: network structure and coexistence under different information regimes

The paper analyzes how the structure of interaction networks affects the diffusion patterns and market shares of different products in case of local network externalities and imperfect information. The diffusion of the different products/technologies in the market is modelled as the result of two (only partly) interrelated dynamics: i) the interaction between idiosyncratic individual thresholds and local network externalities; ii) the diffusion of the information about the product (via broadcast diffusion and word-of-mouth). The average clustering coefficient affects the overall outcome and the actual possibility that one product corners the market. Moreover, in case of small-world networks, despite the high clustering coefficient which increases the probability of an outcome with coexistence, the increase in the speed of diffusion impinges on the actual realization of such an outcome in case of sequential entry of the different technologies and/or imperfect information.Agent-based model, innovation diusion, network eects,social networks, small-world

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 developers’ 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 winner–take–all 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

Brace treatment in juvenile idiopathic scoliosis: a prospective study in accordance with the SRS criteria for bracing studies - SOSORT award 2013 winner.

BACKGROUND: The Juvenile idiopathic scoliosis by age of onset, severity and evolutivity is source of great doubts concerning the purpose and use of conservative treatment. The different clinical experiences leave unsolved the question that arises in applying a conservative treatment when the patients are effectively forward a long growing period, in scoliosis characterized by inevitable evolutivity. The purpose of the present prospective study was to determine the effectiveness of conservative treatment in Juvenile idiopathic scoliosis. METHODS: From 1238 patients treated for idiopathic scoliosis between 1995 and 2012 fulfill the inclusion criteria 163 patients treated with PASB, Lyon brace and Milwaukee. Of these, 113 patients had a definite outcome, 27 have abandoned treatment e 23 are still in treatment. The minimum follow-up was 24 months. Radiographs were used to estimate the curve magnitude (CM) and the torsion of the apical vertebra (TA) at 5 time points: beginning (t1), 6 months after the beginning (t2), intermediate time between t1 and t4 (t3), end of weaning (t4), 2-years minimum follow-up (t5). Three outcomes were distinguished in agreement with SRS criteria: correction, stabilization and progression. RESULTS: The results from our study showed that of the 113 patients with a definite outcome CM mean value was 29.6 ± 7.5 SD at t1 and 16.9 ± 11.1 SD at t5. TA was 13.5 ± 5.4 SD at t1 and 8.5 ± 5.6 at t5. The variations between CM t5-t1 and TA t5-t1 were statistically significantly different. Curve correction was accomplished in 88 patients (77.8%), stabilization was obtained in 18 patients (15.9%). 7 patients (6.19%) have a progression and 4 of these were recommended for surgery. Of 26 patients who abandoned the treatment, at the time of abandonment (12.5 age) have achieved curve correction in 19 cases (70.0%), stabilization in 5 cases (19%) and progression in 3 cases (11%). Of these patients, reviewed at the end of growing, four have been operated on. CONCLUSIONS: Our study confirmed that conservative treatment with brace is highly effective in treating juvenile idiopathic scoliosis, in particular most patients reaching a complete curve correction and only 4.9% of patients need surgery

Reduced GABA Content in the Motor Thalamus during Effective Deep Brain Stimulation of the Subthalamic Nucleus

Deep brain stimulation (DBS) of the subthalamic nucleus (STN), in Parkinson's disease (PD) patients, is a well established therapeutic option, but its mechanisms of action are only partially known. In our previous study, the clinical transitions from OFF- to ON-state were not correlated with significant changes of GABA content inside GPi or substantia nigra reticulata. Here, biochemical effects of STN-DBS have been assessed in putamen (PUT), internal pallidus (GPi), and inside the antero-ventral thalamus (VA), the key station receiving pallidothalamic fibers. In 10 advanced PD patients undergoing surgery, microdialysis samples were collected before and during STN-DBS. cGMP, an index of glutamatergic transmission, was measured in GPi and PUT by radioimmunoassay, whereas GABA from VA was measured by HPLC. During clinically effective STN-DBS, we found a significant decrease in GABA extracellular concentrations in VA (−30%). Simultaneously, cGMP extracellular concentrations were enhanced in PUT (+200%) and GPi (+481%). These findings support a thalamic dis-inhibition, in turn re-establishing a more physiological corticostriatal transmission, as the source of motor improvement. They indirectly confirm the relevance of patterning (instead of mere changes of excitability) and suggest that a rigid interpretation of the standard model, at least when it indicates the hyperactive indirect pathway as key feature of hypokinetic signs, is unlikely to be correct. Finally, given the demonstration of a key role of VA in inducing clinical relief, locally administration of drugs modulating GABA transmission in thalamic nuclei could become an innovative therapeutic strategy

Diet enrichment with a specific essential free amino acid mixture improves healing of undressed wounds in aged rats

Chronic wounds are a major, often underestimated, health problem for the elderly. Standard wound care products are not usuallymanufactured tomeet the increased demand of nutrients by skin cells in order to regenerate new tissue and accelerate healing. This work was therefore undertaken to establish whether wound healing could be accelerated by nutritional supplementation with a specific mixture tailored to human need of essential amino acids (EAAs) without topical medication. To this end, using a skin full-thickness excisional model in aged rats,we compared the closure dynamics of undressing wounds in animals fed an EAAs-enriched diet or standard diet. We assessed the degree of fibrosis and inflammation, as well as relevant signaling molecules such as COL1A1, iNOS and TGFβ1. The results showed wound healing was accelerated in EAAs-fed rats, which was accompanied by reduced inflammation and changes in TGFβ1 and COL1A1 expression. Collectively, our findings indicate that dietary supplementation with balanced EAAs diet could serve as a strategy to accelerate wound healing without inducing fibrosis and could therefore be a simple but pivotal therapeutic approach in human also

Treatment of primary epiglottis collapse in OSA in adults with glossoepiglottopexy: a 5-year experience

Objective. To review our 5-year experience with a modified version of glossoepiglottopexy for treatment of obstructive sleep apnoea syndrome (OSA) in two hospitals.Methods. A retrospective analysis was carried out on a cohort of adult patients affected by OSA suffering from primary collapse of the epiglottis who underwent a modified glossoepiglottopexy. All patients underwent drug-induced sleep endoscopy, polysomnographic and swallowing evaluation, and assessment with the Epworth Sleepiness Scale (ESS).Results. Forty-nine patients were retrospectively evaluated. Both the apnoea-hypopnoea index (AHI) (median AHI(post)-AHI(pre) = -22.4 events/h; p < 0.001) and oxygen desaturation index (ODI) showed a significant postoperative decrease (median ODIpost-ODIpre = -18 events/h; p < 0.001), as did hypoxaemia index (median T-90% post - T-90% pre = 5%; p < 0.001). The ESS questionnaire revealed a significant decrease in postoperative scores (median ESSpost-ESSpre =- 9; p < 0.001). None of the patients developed postoperative dysphagia.Conclusions. Our 5-year experience demonstrates that modified glossoepiglottopexy is a safe and reliable surgical technique for treatment of primary epiglottic collapse in OSA patients

Protein Intake and Cognitive Function in Older Adults: A Systematic Review and Meta-Analysis

Introduction: The present study investigated the association between protein intake and cognitive function in older adults.Methods: We performed a literature search with no restriction on publication year in MEDLINE, SCOPUS, CINAHL, Age-Line from inception up to October 2020. Observational studies that investigated as a primary or secondary outcome the association of protein intake and cognitive function in older adults aged &gt;= 60 years were included.Results : Nine cross-sectional studies that investigated a total of 4929 older adults were included in the qualitative analysis. Overall cognitive function was examined in 6 studies. Four investigations reported null associations and 2 studies found that older adults with a high protein intake had higher global cognitive function than their counterparts. Results from the meta-analysis suggested that there were no significant associations between protein consumption and global cognitive function in older adults, regardless of gender. Three studies investigated other cognitive domains. Memory and protein intake were significantly and positively correlated in all studies. In addition, visuospatial, verbal fluency, processing speed, and sustained attention were positively associated with protein consumption in 1 study each.Conclusion: No significant associations between protein intake and global cognitive function were observed in neither qualitative nor quantitative analyses. The association between protein consumption with multiple other cognitive domains were also tested. As a whole, 3 studies reported a positive and significant association between high protein intake and memory, while 1 study observed a significant and positive association with visuospatial, verbal fluency, processing speed, and sustained attention

Body Weight Loss and Tissue Wasting in Late Middle-Aged Mice on Slightly Imbalanced Essential/Non-essential Amino Acids Diet

Objective: Inadequate protein intake can impair protein balance thus leading to skeletal muscle atrophy, impaired body growth, and functional decline. Foods provide both non-essential (NEAAs) and essential amino acids (EAAs) that may convey different metabolic stimuli to specific organs and tissues. In this study, we sought to evaluate the impact of six diets, with various EAA/NEAA blends, on body composition and the risk of developing tissue wasting in late middle-aged male mice. Methods: Six groups of late middle-aged male mice were fed for 35 days with iso-nutrients, iso-caloric and iso-nitrogenous special diets containing different EAA/NEAA ratios ranging from 100%/0% to 0%/100%. One group fed with standard laboratory rodent diet (StD) served as control. Preliminarily, we verified the palatability of the diets by recording the mice preference, and by making accessible all diets simultaneously, in comparison to StD. Body weight, food and water consumption were measured every three days. Blood and urine samples, as well as heart, kidneys, liver, spleen, triceps surae, retroperitoneal WAT, and BAT were harvested and weighed. Results: Mice consuming NEAA-based diets, although showing increased food and calorie intake, suffered the most severe weight loss. Interestingly, the diet containing a EAA/NEAA-imbalance, with moderate NEAAs prevalence, was able to induce catabolic stimuli, generalized body wasting and systemic metabolic alterations comparable to those observed with diet containing NEAA alone. In addition, complete depletion of retroperitoneal white adipose tissue and a severe loss (>75%) of brown adipose tissue were observed together with muscle wasting. Conversely, EAA-containing diets induced significant decreases in body weight by reducing primarily fat reserves, but at the same time they improved the clinical parameters. On these basis we can deduce that tissue wasting was caused by altered AA quality, independent of reduced nitrogen or caloric intake. Conclusion: Our results indicate that diets containing an optimized balance of AA composition is necessary for preserving overall body energy status. These findings are particularly relevant in the context of aging and may be exploited for contrasting its negative correlates, including body wasting

Interaction of Skeletal and Left Ventricular Mass in Older Adults with Low Muscle Performance

BACKGROUND: It was recently hypothesized the existence of “cardiac-skeletal muscle axis.” However, the relationship between skeletal muscle mass (SMM) and left ventricular mass (LVM) has never been investigated in the specific group of older individuals with low skeletal mass and physical performance. We tested this hypothesis in the SPRINT-T (Sarcopenia and Physical Frailty IN older people: multicomponenT Treatment strategies Trial) population using LVM as independent variable and SMM as dependent variable. METHODS: SMM was assessed by dual-energy X-ray absorptiometry scan and expressed as appendicular lean mass (ALM), and LVM was estimated through echocardiography. Low ALM was defined according to Foundation for the National Institutes of Health Sarcopenia Project criteria, and Short Physical Performance Battery (SPPB) was used to assess physical performance.RESULTS: The population consisted of 100 persons (33 men and 67 women), aged 70 years or older (mean age = 79 5 years) with low ALM and SPPB ranged between 3 and 9, suggestive of physical frailty. Charlson Comorbidity Index median score was 0. Mean value of LVM was 193 67 g, indexed LVM/body surface area (LVM/BSA) was 112 33 g/m2, and cardiac output (CO) was 65 19 L/min. ALM was strongly and positively correlated with LVM (r = 0.54602; P &lt; .0001), LVM/BSA (r = 0.30761; P &lt; .002), CO (r = 0.49621; P &lt; .0001), body mass index (BMI) (r = 0.52461; P &lt; .0001), sex (r = 0.77; P &lt; .001), fat mass (r = 0.38977; P &lt; .0001), and hemoglobin (Hb) (r = 0.26001; P &lt; .01). In the multivariate analysis, LVM (β = .019 .005; P &lt; .0001), CO (β = .038 .016; P = .019), BMI (β = .286 .051; P &lt; .0001), and Hb (β = .544 .175; P = .0025) remained associated to ALM. CONCLUSIONS: In a sample of older persons with low muscle mass and physical performance, LVM was positively and significantly correlated with ALM, independently from blood pressure, physical activity, and other potential confounders. Future studies are needed to address the effect of interventions targeting LVM and SMM