3,337 research outputs found
Symbolic Quantitative Information Flow
acmid: 2382791 issue_date: November 2012 keywords: algorithms, security, verification numpages: 5acmid: 2382791 issue_date: November 2012 keywords: algorithms, security, verification numpages: 5acmid: 2382791 issue_date: November 2012 keywords: algorithms, security, verification numpages: 5acmid: 2382791 issue_date: November 2012 keywords: algorithms, security, verification numpages: 5acmid: 2382791 issue_date: November 2012 keywords: algorithms, security, verification numpages:
Avantage comparatif et performance dans le commerce international des produits différenciés
Ce travail se propose de tester l’hypothèse que les performances nettes réalisées par un pays dans ses échanges extérieurs croisés de produits différenciés sont déterminés 1) par l’avantage comparatif « révélé » défini pour chaque produit, en conformité avec sa base conceptuelle, et 2) par l’effet spécifique propre à l’économie nationale dont l’appropriation au profit de la branche relève des « économies de champs ».Nos résultats empiriques suggèrent que la spécialisation internationale inter-branche tend à se conformer à l’avantage comparatif, malgré une influence certaine exercée par les facteurs spécifiques dans le plus court terme.The paper tests the hypothesis that a country's net performance in its bilateral trade in differentiated products is determined by 1) "revealed" comparative advantage defined for the industry, in accordance with its conceptual basis, and 2) specific factors related to the country, whose benefit to the industry may be viewed as exploitation of economies of scope.Our empirical findings suggest that influence of specific factors could alter somewhat effects of comparative advantage, but the latters still remain dominant in the long run
Vitamin D: a review on its effects on muscle strength, the risk of fall, and frailty.
Vitamin D is the main hormone of bone metabolism. However, the ubiquitary nature of vitamin D receptor (VDR) suggests potential for widespread effects, which has led to new research exploring the effects of vitamin D on a variety of tissues, especially in the skeletal muscle. In vitro studies have shown that the active form of vitamin D, calcitriol, acts in myocytes through genomic effects involving VDR activation in the cell nucleus to drive cellular differentiation and proliferation. A putative transmembrane receptor may be responsible for nongenomic effects leading to rapid influx of calcium within muscle cells. Hypovitaminosis D is consistently associated with decrease in muscle function and performance and increase in disability. On the contrary, vitamin D supplementation has been shown to improve muscle strength and gait in different settings, especially in elderly patients. Despite some controversies in the interpretation of meta-analysis, a reduced risk of falls has been attributed to vitamin D supplementation due to direct effects on muscle cells. Finally, a low vitamin D status is consistently associated with the frail phenotype. This is why many authorities recommend vitamin D supplementation in the frail patient
Cardiac interventions in patients with achondroplasia: a systematic review.
Patients with achondroplasia and other causes of dwarfism suffer from increased rates of cardiovascular disease relative to the remainder of the population. Few studies have examined these patients when undergoing cardiac surgery or percutaneous intervention. This systematic review examines the literature to determine outcomes following cardiac intervention in this unique population. An electronic search was performed in the English literature to identify all reports of achondroplasia, dwarfism, and cardiac intervention. Of the 5,274 articles identified, 14 articles with 14 cases met inclusion criteria. Patient-level data was extracted and analyzed. Median patient age was 55.5 [interquartile ranges (IQR), 43.8, 59.8] years, median height 102.0 [98.8, 112.5] cm, median BMI 32.1 [27.0, 45.9], and 57.1% (8/14) were male. Of these 14 patients, nine had the following documented skeletal abnormalities: 66.7% (6/9) had scoliosis, 66.7% (6/9) had kyphosis, 11.1% (1/9) had lordosis, 11.1% (1/9) pectus carinatum and 11.1% (1/9) spinal stenosis. Coronary artery disease was present in 53.8% (7/13), and 30.8% (4/13) patients previously suffered a myocardial infarction. Of the eight patients who underwent cardiac surgery, 37.5% (3/8) underwent multivessel coronary artery bypass grafting, 37.5% (3/8) underwent aortic valve replacement, 25.0% (2/8) underwent type A aortic dissection repair, and the remaining 12.5% (1/8) underwent pulmonary thromboendarterectomy. Six patients underwent percutaneous intervention. Median cardiopulmonary bypass time was 136.5 [110.0, 178.8] minutes. Median arterial cannula size was 20.0 [20.0, 24.0] Fr. Bicaval cannulation was performed in all cases describing cannulation strategy (5/5). Median superior vena cava cannula size was 28.0 [28.0, 28.0] Fr, and inferior vena cava cannula size was 28.0 [28.0, 28.0] Fr. No mortality was reported with a median follow up time of 6.0 [6.0, 10.5] months. In conclusion, Common cardiac procedures can be performed with reasonable safety in this patient population. Operative adjustments may need to be made with respect to equipment to accommodate patient-specific needs
Preclinical Pharmacokinetics, Pharmacodynamics and Safety of Sucroferric Oxyhydroxide.
Sucroferric oxyhydroxide (VELPHORO(®)) is a polynuclear iron-based phosphate binder recently approved for the treatment of hyperphosphataemia in patients with chronic kidney disease (CKD). As a number of the available phosphate binders do not provide the optimal combination of good efficacy, adequate tolerability and low pill burden, sucroferric oxyhydroxide constitutes a promising alternative. Among the attributes of an ideal phosphate binder is minimal absorption and, hence, low risk of systemic toxicity. Accordingly, the iron-releasing properties and absorption, distribution, metabolism and excretion (ADME) profile of sucroferric oxyhydroxide, as well as the possibility of iron accumulation and toxicity, were investigated in a series of preclinical studies. The effect of sucroferric oxyhydroxide on the progression of vascular calcification was also investigated. Sucroferric oxyhydroxide exhibited a high phosphate-binding capacity and low iron-releasing properties across the physiological pH range found in the gastrointestinal tract. In the ADME studies, uptake of (59)Fe-radiolabelled sucroferric oxyhydroxide was low in rats and dogs (<1% from a 50 mg Fe/kg bodyweight dose), with the majority of absorbed iron located in red blood cells. Long-term (up to 2 years) administration of sucroferric oxyhydroxide in rats and dogs was associated with modest increases in tissue iron levels and no iron toxicity. Moreoever, in uraemic rats, sucroferric oxyhydroxide was associated with reduced progression of vascular calcification compared with calcium carbonate. In conclusion, sucroferric oxyhydroxide offers a new option for the treatment of hyperphosphataemia, with a high phosphate-binding capacity, minimal iron release, and low potential for iron accumulation and toxicity
Antimicrobial and anti-inflammatory activity of chitosan-alginate nanoparticles: a targeted therapy for cutaneous pathogens.
Advances in nanotechnology have demonstrated potential application of nanoparticles (NPs) for effective and targeted drug delivery. Here we investigated the antimicrobial and immunological properties and the feasibility of using NPs to deliver antimicrobial agents to treat a cutaneous pathogen. NPs synthesized with chitosan and alginate demonstrated a direct antimicrobial activity in vitro against Propionibacterium acnes, the bacterium linked to the pathogenesis of acne. By electron microscopy (EM) imaging, chitosan-alginate NPs were found to induce the disruption of the P. acnes cell membrane, providing a mechanism for the bactericidal effect. The chitosan-alginate NPs also exhibited anti-inflammatory properties as they inhibited P. acnes-induced inflammatory cytokine production in human monocytes and keratinocytes. Furthermore, benzoyl peroxide (BP), a commonly used antiacne drug, was effectively encapsulated in the chitosan-alginate NPs and demonstrated superior antimicrobial activity against P. acnes compared with BP alone while demonstrating less toxicity to eukaryotic cells. Together, these data suggest the potential utility of topical delivery of chitosan-alginate NP-encapsulated drug therapy for the treatment of dermatologic conditions with infectious and inflammatory components
Effect of the Synthetic Bile Salt Analog CamSA on the Hamster Model of Clostridium difficile Infection
Clostridium difficile infection (CDI) is the leading cause of antibiotic-associated diarrhea and has gained worldwide notoriety due to emerging hypervirulent strains and the high incidence of recurrence. We previously reported protection of mice from CDI using the antigerminant bile salt analog CamSA. Here we describe the effects of CamSA in the hamster model of CDI. CamSA treatment of hamsters showed no toxicity and did not affect the richness or diversity of gut microbiota; however, minor changes in community composition were observed. Treatment of C. difficile-challenged hamsters with CamSA doubled the mean time to death, compared to control hamsters. However, CamSA alone was insufficient to prevent CDI in hamsters. CamSA in conjunction with suboptimal concentrations of vancomycin led to complete protection from CDI in 70% of animals. Protected animals remained disease-free at least 30 days postchallenge and showed no signs of colonic tissue damage. In a delayed-treatment model of hamster CDI, CamSA was unable to prevent infection signs and death. These data support a putative model in which CamSA reduces the number of germinating C. difficile spores but does not keep all of the spores from germinating. Vancomycin halts division of any vegetative cells that are able to grow from spores that escape CamSA
Resource Provisioning and Allocation in Function-as-a-Service Edge-Clouds
Edge computing has emerged as a new paradigm to bring cloud applications closer to users for increased performance. Unlike back-end cloud systems which consolidate their resources in a centralized data center location with virtually unlimited capacity, edge-clouds comprise distributed resources at various computation spots, each with very limited capacity. In this paper, we consider Function-as-a-Service (FaaS) edge-clouds where application providers deploy their latency-critical functions that process user requests with strict response time deadlines. In this setting, we investigate the problem of resource provisioning and allocation. After formulating the optimal solution, we propose resource allocation and provisioning algorithms across the spectrum of fully-centralized to fully-decentralized. We evaluate the performance of these algorithms in terms of their ability to utilize CPU resources and meet request deadlines under various system parameters. Our results indicate that practical decentralized strategies, which require no coordination among computation spots, achieve performance that is close to the optimal fully-centralized strategy with coordination overheads
Surface Potential of MIBC at Air/Water Interface: a Molecular Dynamics Study
The interfacial behavior of alcohols is significantly different from bulk due to amphiphilic structures. Such behavior can dramatically change the interfacial properties within the nano-scale of interfacial layer and have significant applications in industrial processes such as mineral flotation. In this study, the adsorption of MIBC (methyl isobutyl carbinol), a popular frother, was investigated by molecular dynamics. Surface potential was obtained at different surface concentration and compared to experimental data. The simulations results compared well with theoretical data using a single adjustable parameter. It has been found that the disordered water molecules contribute to surface potential more than MIBC molecules. The study demonstrates the application of MD in investigating the efficiency of frother systems
SleepTransformer: Automatic Sleep Staging with Interpretability and Uncertainty Quantification.
BACKGROUND: Black-box skepticism is one of the main hindrances impeding deep-learning-based automatic sleep scoring from being used in clinical environments. METHODS: Towards interpretability, this work proposes a sequence-to-sequence sleep staging model, namely SleepTransformer. It is based on the transformer backbone and offers interpretability of the models decisions at both the epoch and sequence level. We further propose a simple yet efficient method to quantify uncertainty in the models decisions. The method, which is based on entropy, can serve as a metric for deferring low-confidence epochs to a human expert for further inspection. RESULTS: Making sense of the transformers self-attention scores for interpretability, at the epoch level, the attention scores are encoded as a heat map to highlight sleep-relevant features captured from the input EEG signal. At the sequence level, the attention scores are visualized as the influence of different neighboring epochs in an input sequence (i.e. the context) to recognition of a target epoch, mimicking the way manual scoring is done by human experts. CONCLUSION: Additionally, we demonstrate that SleepTransformer performs on par with existing methods on two databases of different sizes. SIGNIFICANCE: Equipped with interpretability and the ability of uncertainty quantification, SleepTransformer holds promise for being integrated into clinical settings
- …