91 research outputs found
Metastability of Glauber dynamics with inhomogeneous coupling disorder
We introduce a general class of mean-field-like spin systems with random
couplings that comprises both the Ising model on inhomogeneous dense random
graphs and the randomly diluted Hopfield model. We are interested in
quantitative estimates of metastability in large volumes at fixed temperatures
when these systems evolve according to a Glauber dynamics, i.e. where spins
flip with Metropolis rates at inverse temperature . We identify
conditions ensuring that with high probability the system behaves like the
corresponding system where the random couplings are replaced by their averages.
More precisely, we prove that the metastability of the former system is implied
with high probability by the metastability of the latter. Moreover, we consider
relevant metastable hitting times of the two systems and find the asymptotic
tail behaviour and the moments of their ratio. This work provides an extension
of the results known for the Ising model on the the Erd\H{o}s-R\'enyi random
graph. The proofs use the potential-theoretic approach to metastability in
combination with concentration inequalities.Comment: 30 page
Frequent Itemsets Mining for Big Data: A Comparative Analysis
Itemset mining is a well-known exploratory data mining technique used to discover interesting correlations hidden in a data collection. Since it supports different targeted analyses, it is profitably exploited in a wide range of different domains, ranging from network traffic data to medical records. With the increasing amount of generated data, different scalable algorithms have been developed, exploiting the advantages of distributed computing frameworks, such as Apache Hadoop and Spark.
This paper reviews Hadoop- and Spark-based scalable algorithms addressing the frequent itemset mining problem in the Big Data domain through both theoretical and experimental comparative analyses. Since the itemset mining task is computationally expensive, its distribution and parallelization strategies heavily affect memory usage, load balancing, and communication costs. A detailed discussion of the algorithmic choices of the distributed methods for frequent itemset mining is followed by an experimental analysis comparing the performance of state-of-the-art distributed implementations on both synthetic and real datasets. The strengths and weaknesses of the algorithms are thoroughly discussed with respect to the dataset features (e.g., data distribution, average transaction length, number of records), and specific parameter settings. Finally, based on theoretical and experimental analyses, open research directions for the parallelization of the itemset mining problem are presented
Cluster expansion in the canonical ensemble
We consider a system of particles confined in a box \La\subset\R^d
interacting via a tempered and stable pair potential. We prove the validity of
the cluster expansion for the canonical partition function in the high
temperature - low density regime. The convergence is uniform in the volume and
in the thermodynamic limit it reproduces Mayer's virial expansion providing an
alternative and more direct derivation which avoids the deep combinatorial
issues present in the original proof
在籍生徒の当校選択意識とその実態 : 不適応生徒発生の一条件として
Objective To determine whether the mode of delivery is associated with the risk of celiac disease (CD) in a cohort of children genetically predisposed to CD prospectively followed from birth. Study design By telephone interview, we recorded information on the mode of delivery of children participating in the Risk of Celiac Disease and Age at Gluten Introduction study, a multicenter, prospective intervention trial that compared early and delayed introduction of gluten in infants with at least 1 first-degree relative affected with CD. The human leukocyte antigen genotype was determined at 15 months of age, and serologic screening for CD was performed at 15, 24, and 36 months of age and at 5, 8, and 10 years of age. Patients with positive serologic findings underwent intestinal biopsy. The primary outcome of the current study was the prevalence of CD autoimmunity and overt CD at 5 years of age, according to the mode of delivery. Results The study-group included 553 children at CD risk because of positivity for human leukocyte antigen-DQ2, -DQ8, or both. We obtained data on the mode of delivery from 431 of 553 children; 233 of 431 children were born by vaginal delivery (54%). At 5 years of age, the prevalence of CD autoimmunity or overt CD was not different between children born by cesarean or vaginal delivery (24% and 19%, P=.2; 19% and 14%, P=.2 respectively, by the log-rank test). Conclusions In this cohort of children genetically predisposed to CD, the mode of delivery did not influence the risk of developing CD
"Diagnosis on the Dock" project: A proactive screening program for diagnosing pulmonary tuberculosis in disembarking refugees and new SEI model.
Abstract Objective From 2011 to 2017, the total number of refugees arriving in Europe, particularly in Italy, climbed dramatically. Our aim was to diagnose pulmonary TB in migrants coming from the African coast using a clinical-based port of arrival (PoA) screening program. Methods From 2016 to 2018, migrants coming via the Mediterranean Route were screened for body temperature and the presence of cough directly on the dock: if they were feverish with productive cough, their sputum was examined with NAAT; with a dry cough, they underwent Chest-X-ray (CXR). Those migrants with positive NAAT or CXR suggestive for TB were admitted to our ward. In addition, we plotted an SEI simulation of our project to evaluate the epidemiological impact of our screening. Results Out of 33.676 disembarking migrants, 314 (0.9%) had fever and cough: 80 (25.47%) with productive cough underwent NAAT in sputum, and 16 were positive for TB; 234 (74.52%) with dry cough had a CXR examination, and 39 were suggestive of TB, later confirmed by mycobacterial culture. The SEI-new model analysis demonstrated that our screening program significantly reduced TB spreading all over the country. Conclusions For possible future high migrant flows, PoA screening for TB has to be considered feasible and effective in decreasing TB spreading
Recommended from our members
PLoS One
Advancement of biomedical applications of carbonaceous nanomaterials is hampered by their biopersistence and pro-inflammatory action in vivo. Here, we used myeloperoxidase knockout B6.129X1-MPO (MPO k/o) mice and showed that oxidation and clearance of single walled carbon nanotubes (SWCNT) from the lungs of these animals after pharyngeal aspiration was markedly less effective whereas the inflammatory response was more robust than in wild-type C57Bl/6 mice. Our results provide direct evidence for the participation of MPO - one of the key-orchestrators of inflammatory response - in the in vivo pulmonary oxidative biodegradation of SWCNT and suggest new ways to control the biopersistence of nanomaterials through genetic or pharmacological manipulations.HL094488/HL/NHLBI NIH HHS/United StatesHL70755/HL/NHLBI NIH HHS/United StatesLM007994-05/LM/NLM NIH HHS/United StatesOH008282/OH/NIOSH CDC HHS/United StatesR01 ES019304/ES/NIEHS NIH HHS/United StatesR01ES019304/ES/NIEHS NIH HHS/United StatesU19AI068021/AI/NIAID NIH HHS/United StatesU54 GM103529/GM/NIGMS NIH HHS/United States22479306PMC331652
A Conceptual Framework for Vulnerability and Risk Assessment in the Context of Nature-Based Solutions to Hydro-Meteorological Risks
Various frameworks for vulnerability and risk assessment of social-ecological systems (SES) to natural hazards have been developed addressing different contexts. However, none were specifically developed in the context of implementing nature-based solutions (NBS) to hydro-meteorological risks. Since the basic concepts and principles of NBS are mainly focused on ensuring balance between ecological and social benefits, the entire vulnerability and risk assessment process should focus equally on various social and ecological components of a location where an NBS would be implemented. As a part of the OPEn-air laboRAtories for Nature baseD solUtions to Manage hydro-meteo risks (OPERANDUM) project, this research proposes a conceptual framework for vulnerability and risk assessment in the context of NBS to hydro-meteorological risks. This conceptual framework is developed mainly considering the major components of the existing Delta-SES risk assessment framework (Sebesvari et al. 2016) and other similar frameworks proposed in recent studies, as well as the proposed principles for NBS endorsed by International Union for Conservation of Nature (IUCN). The major components of the framework include: (i) the exposure of SES to multiple hydro-meteorological hazards (e.g., flood, drought); (ii) vulnerability of SES that consists of ecosystem susceptibility, social susceptibility, ecosystem robustness, and coping and adaptive capacity of the social system; (iii) risks in the NBS project site determined by the combination of hazard exposure and vulnerability; and (iv) the impacts of hydro-meteorological hazards on the SES surrounding or within the NBS project site. While the basic space of risk assessment would be the NBS project site (usually at the local level within sub-catchments) with specific SES characteristics, this framework also reflects the interrelationships between ecosystem and social system as well as the effects of multiple hazards and risks at local up to the global scales. The framework also considers the changes over time that would capture the maturation time lag of the ecological components of an NBS, as well as the sustainability of the system with the intervention of NBS and other risk reduction measures. An indicator-based risk assessment approach can be used to operationalize the framework. To facilitate that, an indicator library has been developed comprising of indicators for different exposure and vulnerability components of the framework. The proposed framework can be applicable to any geographical conditions where an NBS project is to be implemented to reduce hydro-meteorological risks. The framework can also be tailored for other natural hazards (e.g. geological hazards like earthquake) and anthropogenic hazards (e.g. pollution). We will explain the conceptualisation process of the framework and of the indicator library and how these will be tested within the OPERANDUM project in the context of NBS implementation
- …