Mobile geolocation data is a valuable asset in the assessment of movement patterns of a population. Once a highly contagious disease takes place in a location the movement patterns aid in predicting ...the potential spatial spreading of the disease, hence mobile data becomes a crucial tool to epidemic models. In this work, based on millions of anonymized mobile visits data in Brazil, we investigate the most probable spreading patterns of the COVID-19 within states of Brazil. The study is intended to help public administrators in action plans and resources allocation, whilst studying how mobile geolocation data may be employed as a measure of population mobility during an epidemic. This study focuses on the states of São Paulo and Rio de Janeiro during the period of March 2020, when the disease first started to spread in these states. Metapopulation models for the disease spread were simulated in order to evaluate the risk of infection of each city within the states, by ranking them according to the time the disease will take to infect each city. We observed that, although the high-risk regions are those closer to the capital cities, where the outbreak has started, there are also cities in the countryside with great risk. The mathematical framework developed in this paper is quite general and may be applied to locations around the world to evaluate the risk of infection by diseases, in special the COVID-19, when geolocation data is available.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper uses a classical approach to feature selection: minimization of a cost function applied on estimated joint distributions. However, in this new formulation, the optimization search space is ...extended. The original search space is the Boolean lattice of features sets (BLFS), while the extended one is a collection of Boolean lattices of ordered pairs (CBLOP), that is (features, associated value), indexed by the elements of the BLFS. In this approach, we may not only select the features that are most related to a variable Y, but also select the values of the features that most influence the variable or that are most prone to have a specific value of Y. A local formulation of Shannon’s mutual information, which generalizes Shannon’s original definition, is applied on a CBLOP to generate a multiple resolution scale for characterizing variable dependence, the Local Lift Dependence Scale (LLDS). The main contribution of this paper is to define and apply the LLDS to analyse local properties of joint distributions that are neglected by the classical Shannon’s global measure in order to select features. This approach is applied to select features based on the dependence between: i-the performance of students on university entrance exams and on courses of their first semester in the university; ii-the congress representative party and his vote on different matters; iii-the cover type of terrains and several terrain properties.
A resolvent approach to metastability Landim, Claudio; Marcondes, Diego; Seo, Insuk
Journal of the European Mathematical Society,
12/2023
Journal Article
We present a general method to derive the metastable behavior ofweakly mixing Markov chains. This approach is based on properties ofthe resolvent equations and can be applied to metastable ...dynamicswhich do not satisfy the mixing conditions required in \cite{BL1, BL2}or in \cite{LMS2}.As an application, we study the metastable behavior of criticalzero-range processes. Let $r: S\times S\to \bb R_+$ be the jump ratesof an irreducible random walk on a finite set $S$, reversible withrespect to the uniform measure. For $\alpha >0$, let$g: \bb N\to \bb R_+$ be given by $g(0)=0$, $g(1)=1$,$g(k) = k/(k-1)^\alpha$, $k\ge 2$. Consider a zero-range process on$S$ in which a particle jumps from a site $x$, occupied by $k$particles, to a site $y$ at rate $g(k) r(x,y)$. For $\alpha \ge 1$, inthe stationary state, as the total number of particles, represented by$N$, tends to infinity, all particles but a negligible numberaccumulate at one single site. This phenomenon is calledcondensation. Since condensation occurs if and only if $\alpha\ge 1$,we call the case $\alpha =1$ critical. By applying the general methodestablished in the first part of the article to the critical case, weshow that the site which concentrates almost all particles evolves inthe time-scale $N^2 \log N$ as a random walk on $S$ whose transitionrates are proportional to the capacities of the underlying randomwalk.
A Resolvent Approach to Metastability Landim, C; Marcondes, D; Seo, I
HAL (Le Centre pour la Communication Scientifique Directe),
07/2023
Paper, Journal Article
Recenzirano
Odprti dostop
We provide a necessary and sufficient condition for the metastability of a Markov chain, expressed in terms of a property of the solutions of the resolvent equation. As an application of this result, ...we prove the metastability of reversible, critical zero-range processes starting from a configuration.
In order to use psychometric instruments to assess a multidimensional construct, we may decompose it into dimensions and, in order to assess each dimension, develop a set of items, so one may assess ...the construct as a whole, by assessing its dimensions. In this scenario, content analysis of items aims to verify if the developed items are assessing the dimension they are supposed to by requesting the judgement of specialists in the studied construct about the dimension that the developed items assess. This paper aims to develop a nonparametric statistical approach based on the Cochran’s Q test to analyse the content of items in order to present a practical method to assess the consistency of the content analysis process; this is achieved by the development of a statistical test that seeks to determine if all the specialists have the same capability to judge the items. A simulation study is conducted to check the consistency of the test and it is applied to a real validation process.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A compreensão dos mecanismos moleculares controladores do desenvolvimento, função e regressão do CL bovino é necessária para o aprimoramento da manipulação hormonal ovariana. Fortes evidências sugerem o envolvimento de fatores de crescimento fibroblástico (FGFs) na regulação do crescimento e regressão do CL. “Splicing” alternativo de 4 genes formam sete subtipos de FGFRs com afinidade variável por diferentes FGFs. Os membros da subfamília do FGF8 (FGF8, 17 e 18) ativam eficientemente o FGFR3C e 4 e podem atuar em cooperação nos tecidos que expressão estes receptores. O objetivo deste trabalho foi determinar o padrão de expressão dos FGFRs e dos membros da subfamília do FGF8 no CL bovino (CL). Os CLs foram obtidos de ovários de abatedouro e classificados em 4 estádios de desenvolvimento (estádio/1= corpo hemorrágico, estádio/2= CL em desenvolvimento, estádio/3= CL maduro/início da luteólise funcional e estádio/4= luteólise estrutural). O RNAm foi mensurado por PCR semiquantitativo e a proteína localizada por imunohistoquímica. A expressão do RNAm codificante das isoformas ‘B’ e ‘C’ de FGFR1 e FGFR2 foi detectada no CL bovino por PCR associado à eletroforese e foi acompanhada pela localização da proteína nas pequenas e grandes células luteínicas. A expressão do RNAm do FGFR1C e 2C não variou durante o desenvolvimento luteínico, distintamente a expressão do FGFR1B aumentou no estádio 3. Embora os FGFRs 3B, 3C e 4 tenham sido detectados de forma inconsistente por PCR associado à eletroforese, o RNAm do FGFR3C e FGFR4 foram detectados por PCR em tempo real em todos os estádios do desenvolvimento luteínico. O RNAm do FGF18 foi detectado por PCR em tempo real em todos os estádios do desenvolvimento luteínico e sua abundancia do RNAm do FGF18 foi maior no estádio 3 comparado com os estádios 1, 2 e 4. Em contraste, os RNAm do FGF8 e 17...
The molecular mechanisms controlling the development, function and regression of the bovine corpus luteum are necessary for the improvement of reproductive biotechnologies. Strong evidence suggests the involvement of fibroblast growth factors (FGFs) in the regulation of growth, and regression of the corpus luteum (CL). Alternative splicing of 4 genes give rise to seven subtypes of FGFRs with varying affinity for different FGFs. FGF8 subfamily members (FGF8, 17 and 18) efficiently activate FGFR3C and FGFR4 and may act in cooperation in tissues expressing these receptors. The objective of the present study was to determine the pattern of expression of FGF8 subfamily members and FGFRs in the bovine CL. Bovine CLs were obtained from abattoir ovaries and classed into four stages of development (stage 1= corpus hemorragicum, stage 2= developing CL, stage 3= mature/early functional luteolysis CL, and stage 4= structural luteolysis). Expression of mRNA was measured by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) followed by gel analysis (FGFR1-4) and real time RT-PCR (FGF8 subfamily members, FGFR3C and FGFR4) and proteins were localized by immunohistochemistry. Expression of mRNA encoding ‘B’ and ‘C’ spliced forms of FGFR1 and FGFR2 was readily detected in the bovine CL and was accompanied by isoform non-specific protein localization. FGFR1C and FGFR2C mRNA expression did not vary throughout CL lifespan, whereas FGFR1B was upregulated in the mature CL (stage III). FGFR3B, FGFR3C and FGFR4 expression was inconsistent in the bovine CL as assessed by PCR associated with gel analysis. FGF18, FGFR3C and FGFR4 mRNA was detected by real time PCR in all four developmental stages, and FGF18 mRNA abundance was higher in stage 3 (2.89 0.05; mean ± SEM) compared with stages 1 (0.3 0.27), 2 (0.56 1.27) and 4 (0.99 0.32). The m RNA expression ... (Complete abstract click electronic access below)
Abstract
Sortition, i.e. random appointment for public duty, has been employed by societies throughout the years as a firewall designated to prevent illegitimate interference between parties in a ...legal case and agents of the legal system. In judicial systems of modern western countries, random procedures are mainly employed to select the jury, the court and/or the judge in charge of judging a legal case. Therefore, these random procedures play an important role in the course of a case, and should comply with some principles, such as transparency and complete auditability. Nevertheless, these principles are neglected by random procedures in some judicial systems, which are performed in secrecy and are not auditable by the involved parties. The assignment of cases in the Brazilian Supreme Court is an example of such a procedure, for it is performed using procedures unknown to the parties involved in the judicial cases. This article presents a review of how sortition has been historically employed by societies and discusses how Mathematical Statistics may be applied to random procedures of the judicial system, as it has been applied for almost a century on clinical trials, for example. A statistical model for assessing randomness in case assignment is proposed and applied to the Brazilian Supreme Court. As final remarks, guidelines for the development of good randomization procedures are outlined.
BIANCHETTI, Lucídio; SGUISSARDI, Valdemar. Da universidade à Commoditycidade: ou de como e quando, se a educação/formação é sacrificada no altar do Mercado, o futuro da universidade se situaria em ...algum lugar do passado. Campinas, SP: Mercado de Letras, 2017
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