Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
An Acad Bras Cienc ; 95(1): e20200255, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36820675

RESUMO

The multilinear Hardy-Littlewood inequalities provide estimates for the sum of the coefficients of multilinear forms T ∶ ℓ p 1 n × â‹¯ × â„“ p m n → R ( or  C ) when 1 / p 1 × â‹¯ × 1 / p m < 1 . In this paper we investigate the critical and super-critical cases; i.e., when 1 / p 1 × â‹¯ × 1 / p m ≥ 1.

2.
Data Brief ; 40: 107783, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35005154

RESUMO

Worldwide, COVID-19 coronavirus disease is spreading rapidly in a second and third wave of infections. In this context of increasing infections, it is critical to know the probability of a specific number of cases being reported. We collated data on new daily confirmed cases of COVID-19 breakouts in: Argentina, Brazil, China, Colombia, France, Germany, India, Indonesia, Iran, Italy, Mexico, Poland, Russia, Spain, U.K., and the United States, from the 20th of January, 2020 to 28th of August 2021. A selected sample of almost ten thousand data is used to validate the proposed models. Generalized Extreme-Value Distribution Type 1-Gumbel and Exponential (1, 2 parameters) models were introduced to analyze the probability of new daily confirmed cases. The data presented in this document for each country provide the daily probability of rate incidence. In addition, the frequencies of historical events expressed as a return period in days of the complete data set is provided.

3.
Sci Total Environ ; 698: 134168, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505353

RESUMO

Arsenic and fluoride in drinking water present a significant challenge to public health worldwide. In this study, we analyze the results of one of the largest surveys of drinking water quality in Mexico: 14,058 samples from 3951 sites, collected between January and December 2017. We use these data to identify the distribution and possible origin of arsenic and fluoride in drinking water throughout the country, and to estimate the associated health burden. The highest concentrations appear in alluvial aquifers in arid northern Mexico, where high-silica volcanic rock likely releases both arsenic and fluoride to the groundwater. We find fluoride contamination to be significantly correlated with aridity (Pearson correlation = -0.45, p = 0.0105), and also find a significant difference in fluoride concentrations between arid and humid states (Welch's t-test, p = 0.004). We estimate population exposure by assigning to each town in Mexico the average concentration of any sampling sites within 5 km. Our results show that 56% of the Mexican population lives within 5 km of a sampling site, 3.05 million people are exposed to fluoride above the reference dosage of 0.06 mg/(kg ∗ day), 8.81 million people are exposed to arsenic above the limit of 10 µg/L, and an additional 13,070 lifetime cases of cancer are expected from this arsenic exposure alone. This burden of disease is concentrated in the arid states of north-central Mexico.


Assuntos
Arsênio/análise , Água Potável/química , Monitoramento Ambiental , Fluoretos/análise , Poluentes Químicos da Água/análise , Humanos , México , Medição de Risco
4.
Q J Exp Psychol (Hove) ; 73(5): 645-653, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31658885

RESUMO

Using a human Pavlovian-to-instrumental transfer (PIT) task, Alarcón and Bonardi showed that the selective elevation of instrumental responding produced by excitatory transfer cues was reduced when these cues were presented with a conditioned inhibitor (CI), relative to a control cue that was simply preexposed. However, previous research has shown that preexposed cues might also acquire inhibitor-like properties. This study aimed to contrast the inhibitory properties of CIs and preexposed cues, using novel stimuli as controls, in summation and PIT tests. Participants were trained to perform two actions, each reinforced with a distinct outcome (O1 or O2). Two images were trained as CIs, each signalling the absence of one of the outcomes, by presenting them with a cue that was otherwise followed by that outcome (e.g., A→O1, AI→no O1). In contrast, the preexposed cues were simply presented in the absence of the outcomes. In the summation test, participants rated the likelihood of the outcomes in the presence of two independently trained excitatory cues, each presented with a CI, a preexposed cue, or a novel stimulus. Similarly, in the PIT test, participants performed both actions in the presence and absence of these compounds. In the summation test, the CIs and the preexposed cues reduced participants' expectations of the outcomes more than the novel stimuli. However, in the PIT test, only the CIs reduced the selective elevation of responding produced by the transfer cues. These results might reflect distinct properties of stimuli trained as CIs and those simply preexposed.


Assuntos
Condicionamento Clássico/fisiologia , Condicionamento Operante/fisiologia , Sinais (Psicologia) , Tomada de Decisões/fisiologia , Inibição Psicológica , Motivação/fisiologia , Transferência de Experiência/fisiologia , Adulto , Feminino , Humanos , Masculino , Reconhecimento Visual de Modelos/fisiologia , Adulto Jovem
5.
Sucre; s.n; 2006. 96 p. tab, graf.
Tese em Espanhol | LILACS-Express | LIBOCS, LIBOSP | ID: biblio-1326479
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA