11 resultados para Lorenz`s attractor

em Scielo Saúde Pública - SP


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Chaotic dynamical systems exhibit trajectories in their phase space that converges to a strange attractor. The strangeness of the chaotic attractor is associated with its dimension in which instance it is described by a noninteger dimension. This contribution presents an overview of the main definitions of dimension discussing their evaluation from time series employing the correlation and the generalized dimension. The investigation is applied to the nonlinear pendulum where signals are generated by numerical integration of the mathematical model, selecting a single variable of the system as a time series. In order to simulate experimental data sets, a random noise is introduced in the time series. State space reconstruction and the determination of attractor dimensions are carried out regarding periodic and chaotic signals. Results obtained from time series analyses are compared with a reference value obtained from the analysis of mathematical model, estimating noise sensitivity. This procedure allows one to identify the best techniques to be applied in the analysis of experimental data.

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OBJECTIVE To analyze the patterns and legal requirements of methylphenidate consumption. METHODS We conducted a cross-sectional study of the data from prescription notification forms and balance lists of drugs sales – psychoactive and others – subject to special control in the fifth largest city of Brazil, in 2006. We determined the defined and prescribed daily doses, the average prescription and dispensation periods, and the regional sales distribution in the municipality. In addition, we estimated the costs of drug acquisition and analyzed the individual drug consumption profile using the Lorenz curve. RESULTS The balance lists data covered all notified sales of the drug while data from prescription notification forms covered 50.6% of the pharmacies that sold it, including those with the highest sales volumes. Total methylphenidate consumption was 0.37 DDD/1,000 inhabitants/day. Sales were concentrated in more developed areas, and regular-release tablets were the most commonly prescribed pharmaceutical formulation. In some regions of the city, approximately 20.0% of the prescriptions and dispensation exceeded 30 mg/day and 30 days of treatment. CONCLUSIONS Methylphenidate was widely consumed in the municipality and mainly in the most developed areas. Of note, the consumption of formulations with the higher abuse risk was the most predominant. Both its prescription and dispensation contrasted with current pharmacotherapeutic recommendations and legal requirements. Therefore, the commercialization of methylphenidate should be monitored more closely, and its use in the treatment of behavioral changes of psychological disorders needs to be discussed in detail, in line with the concepts of the quality use of medicines.

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Introduction More than half of the malaria cases reported in the Americas are from the Brazilian Amazon region. While malaria is considered endemic in this region, its geographical distribution is extremely heterogeneous. Therefore, it is important to investigate the distribution of malaria and to determine regions whereby action might be necessary. Methods Changes in malaria indicators in all municipalities of the Brazilian Amazon between 2003-2004 and 2008-2009 were studied. The malaria indicators included the absolute number of malaria cases and deaths, the bi-annual parasite incidence (BPI), BPI ratios and differences, a Lorenz curve and Gini coefficients. Results During the study period, mortality from malaria remained low (0.02% deaths/case), the percent of municipalities that became malaria-free increased from 15.6% to 31.7%, and the Gini coefficient increased from 82% to 87%. In 2003, 10% of the municipalities with the highest BPI accumulated 67% of all malaria cases, compared with 2009, when 10% of the municipalities (with the highest BPI) had 80% of the malaria cases. Conclusions This study described an overall decrease in malaria transmission in the Brazilian Amazon region. As expected, an increased heterogeneity of malaria indicators was found, which reinforces the notion that a single strategy may not bring about uniformly good outcomes. The geographic clustering of municipalities identified as problem areas might help to define better intervention methods.

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Background: Cardiovascular diseases are the current leading causes of death and disability globally. Objective: To assess the effects of a basic educational program for cardiovascular prevention in an unselected outpatient population. Methods: All participants received an educational program to change to a healthy lifestyle. Assessments were conducted at study enrollment and during follow-up. Symptoms, habits, ATP III parameters for metabolic syndrome, and American Heart Association’s 2020 parameters of cardiovascular health were assessed. Results: A total of 15,073 participants aged ≥ 18 years entered the study. Data analysis was conducted in 3,009 patients who completed a second assessment. An improvement in weight (from 76.6 ± 15.3 to 76.4 ± 15.3 kg, p = 0.002), dyspnea on exertion NYHA grade II (from 23.4% to 21.0%) and grade III (from 15.8% to 14.0%) and a decrease in the proportion of current active smokers (from 3.6% to 2.9%, p = 0.002) could be documented. The proportion of patients with levels of triglycerides > 150 mg/dL (from 46.3% to 42.4%, p < 0.001) and LDL cholesterol > 100 mg/dL (from 69.3% to 65.5%, p < 0.001) improved. A ≥ 20% improvement of AHA 2020 metrics at the level graded as poor was found for smoking (-21.1%), diet (-29.8%), and cholesterol level (-23.6%). A large dropout as a surrogate indicator for low patient adherence was documented throughout the first 5 visits, 80% between the first and second assessments, 55.6% between the second and third assessments, 43.6% between the third and fourth assessments, and 38% between the fourth and fifth assessments. Conclusion: A simple, basic educational program may improve symptoms and modifiable cardiovascular risk factors, but shows low patient adherence.

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O objetivo deste trabalho foi avaliar o desempenho zootécnico e as características bromatológicas e hematológicas de pacus alimentados a diferentes frequências de arraçoamento. Três mil e duzentos peixes, com peso inicial médio de 65,9±2,36 g, foram distribuídos em 16 tanques-rede de 5 m³ de volume útil. Durante 65 dias, foram avaliadas quatro frequências de arraçoamento (tratamentos): T1, às 12:00 h; T2, às 8:00 e às 17:00 h; T3, às 8:00, 12:00 e 17:00 h; e T4, às 8:00, 11:00, 14:00 e 17:00 h. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições. Analisaram-se parâmetros de desempenho produtivo, índices de gordura visceral e hepatossomático, composição centesimal da carcaça e parâmetros hematológicos e bioquímicos. Quanto ao ganho de peso, as frequências T3 e T4 proporcionaram melhores resultados do que T1 e T2. Embora a proteína, o colesterol e os eritrócitos tenham apresentado diferenças entre os tratamentos, permaneceram dentro dos valores de referência para pacus cultivados em tanques-rede. A frequência de três arraçoamentos diários resultou em maior ganho de peso, em comparação aos demais tratamentos, sem interferir na saúde e na composição centesimal das carcaças dos animais.

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Este trabalho teve por objetivo avaliar a influência dos porta-enxertos 'IAC 766', 'IAC 572', 'IAC 313' e 'IAC 571-6' na duração dos estádios fenológicos e no acúmulo de graus- dia pela videira 'Niagara Rosada', cultivada em Votuporanga-SP. O delineamento estatístico utilizado foi em blocos inteiramente casualizados, com parcelas subdivididas, cinco repetições, sendo as parcelas representadas pelos porta-enxertos, e as subparcelas, pelos dois ciclos de produção. Após a poda da videira, foram realizadas avaliações dos estádios fenológicos, utilizando-se do critério de Eichhon e Lorenz (1984). Baseado nos estádios fenológicos, calculou-se a duração dos períodos: poda ao início da brotação; poda ao início do florescimento; poda ao início da frutificação; poda ao início da maturação dos cachos; poda ao início da colheita. Tomando-se por base a duração do ciclo da videira e as temperaturas médias diárias, calculou-se o acúmulo de graus-dia. Obteve-se maior duração do ciclo e do acúmulo de graus-dia da cultivar Niagara Rosada com os porta-enxertos 'IAC 572' e 'IAC 571-6', e a menor, com o porta-enxerto 'IAC 766'. Evidenciou-se a influência do clima na duração dos estádios fenológicos da videira.

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Este trabalho teve por objetivo avaliar a ocorrência de pérola-da-terra (Eurhizococcus brasiliensis) (Hemiptera: Margarodidae), bem como o desenvolvimento vegetativo e a fenologia das videiras 'Isabel', 'Bordô (Vitis labrusca L.), 'Cabernet Sauvignon', 'Malbec' e 'Merlot' (Vitis vinifera L.) enxertadas sobre os porta-enxertos 'Paulsen 1103' e 'VR 043-43'. O experimento foi conduzido no pomar experimental do Departamento de Agronomia da Universidade Estadual do Centro-Oeste (Unicentro), localizado em Guarapuava-PR, durante a safra de 2010/2011. O delineamento experimental adotado foi em blocos casualizados, em esquema fatorial 5 x 2 (cultivares x porta-enxerto), com o total de 10 tratamentos, cinco repetições e três plantas por parcela experimental. Cada bloco foi constituído por uma linha de plantio. Foram avaliados: as massas fresca (MFP) e seca (MSP) do material oriundo da poda de produção. Logo após a colheita dos frutos, as plantas foram retiradas do solo e, posteriormente, quantificou-se o número de pérola-da-terra por planta (NP), as massas fresca (MFR) e seca (MSR) de raízes, as massas fresca (MFC) e seca (MSC) do caule. Além disso, também foi avaliada a duração dos estádios fenológicos baseados na metodologia de Eichhorn e Lorenz (1984). Verificou-se que as videiras enxertadas sobre o 'VR 043-43' apresentaram menor quantidade de cistos de pérola-da-terra, no entanto este fator influenciou positivamente apenas no desenvolvimento vegetativo das cultivares americanas, sendo que, para as demais variáveis analisadas, não houve influência do porta-enxerto.

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Avaliaram-se a influência dos porta-enxertos 'IAC 766', 'IAC 572', 'IAC 313', 'IAC 571-6' e 'Ripária do Traviú' e da época de poda na duração dos estádios fenológicos e no acúmulo de graus-dia pela videira 'Niagara Rosada'. O experimento foi realizado em Louveira-SP. Os tratamentos consistiram na combinação de cinco porta-enxertos e três épocas de poda, sendo utilizado o delineamento experimental em blocos inteiramente casualizados, com parcelas subdivididas e cinco repetições, sendo as parcelas representadas pelos porta-enxertos,e as subparcelas, pelas épocas de poda. Após a poda da videira, foram realizadas avaliações dos estádios fenológicos, utilizando-se do critério de Eichhon e Lorenz (1984). Nas três épocas de poda, baseado nos estádios fenológicos, calculou-se a duração dos períodos: poda ao início da brotação; poda ao pleno florescimento; poda ao início da frutificação; poda ao início da maturação dos cachos, e poda à colheita. Tomando-se por base a duração do ciclo da videira e as temperaturas médias diárias, calculou-se o acúmulo de graus-dia. Os dados foram submetidos à análise de variância e teste Tukey, a 5% de significância. Obteve-se, na poda de verão, redução na duração dos estádios fenológicos da videira 'Niagara Rosada' enxertada sobre o porta-enxerto 'Ripária do Traviú. A maior duração do ciclo e do acúmulo de graus-dia da cultivar Niagara Rosada foi obtida com os porta-enxertos 'IAC 572' e 'IAC 313' nas podas de inverno.

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Cp'Mn(CO)3 (Cp'=h5-C5H4-CH 3) reacts with P(C6H5)2H in THF to give Cp'(CO)2MnPPh2H (Ph = Phenyl) (1), by substitution of one CO ligand. The reaction of 1 with CH3COCl and CH3S(O)2Cl in the presence of triethylamine occurs under electrophilic substitution on the diphenylphosphan ligand to yield the acetyl- and sulfonylphosphane complexes of manganese(I) Cp'(CO)2MnPPh2COCH3 (2) and Cp'(CO)2MnPPh2S(O)2 CH3 (3). The complex stabilisation of these molecules, wich are hitherto unknown in the free state, is only accomplished by blocking the free electron pair on phosphorus by coordination. The new complexes 1, 2 and 3 were analysed by IR, ¹H-NMR and 31P-MNR spectroscopy and their similar structures are discusssed.

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O artigo oferece um novo enfoque do conceito de categoria ontológica. O ponto de partida é a afirmação de que as "ontologias da substância" baseiam-se na aceitação do Princípio da Composicionalidade Semântica, o qual se mostra ter implicações ontológicas inaceitáveis. Este artigo delineia uma nova semântica baseada no Princípio de Contextualidade Sentencial (ou Princípio do Contexto) e, em concordância com ele, uma nova ontologia. A partir desse princípio uma nova categoria semântica denominada "estado de coisas primário" ("primestado", de forma abreviada) é derivada, e é mostrado que sobre essa base é possível desenvolver a categoria ontológica fundamental e, em um sentido, única chamada "fato primário" ("primofato", de forma abreviada).

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Uroguanylin and guanylin are newly discovered endogenous heat-stable peptides that bind to and activate a membrane bound guanylyl cyclase signaling receptor (termed guanylyl cyclase C; GC-C). These peptides are not only found in blood but are secreted into the lumen of the intestine and effect a net secretion of electrolytes (Na+, K+, Cl-, HCO3-) and fluid into the intestine via a cyclic guanosine-3',5'-monophosphate (cGMP) mechanism. GC-C is also the receptor for Escherichia coli heat-stable enterotoxin (STa) and activation by STa results in a diarrheal illness. Employing mouse renal in vivo models, we have demonstrated that uroguanylin, guanylin, and STa elicit natriuretic, kaliuretic, and diuretic effects. These biological responses are time- and dose-dependent. Maximum natriuretic and kaliuretic effects are observed within 30-40 min following infusion with pharmacological doses of the peptides in a sealed-urethra mouse model. Our mouse renal clearance model confirms these results and shows significant natriuresis following a constant infusion of uroguanylin for 30 min, while the glomerular filtration rate, plasma creatinine, urine osmolality, heart rate, and blood pressure remain constant. These data suggest the peptides act through tubular transport mechanisms. Consistent with a tubular mechanism, messenger RNA-differential display PCR of kidney RNA extracted from vehicle- and uroguanylin-treated mice show the message for the Na+/K+ ATPase g-subunit is down-regulated. Interestingly, GC-C knockout mice (Gucy2c -/-) also exhibit significant uroguanylin-induced natriuresis and kaliuresis in vivo, suggesting the presence of an alternate receptor signaling mechanism in the kidney. Thus, uroguanylin and guanylin seem to serve as intestinal and renal natriuretic peptide-hormones influencing salt and water transport in the kidney through GC-C dependent and independent pathways. Furthermore, our recent clinical probe study has revealed a 70-fold increase in levels of urinary uroguanylin in patients with congestive heart failure. In conclusion, our studies support the concept that uroguanylin and guanylin are endogenous effector peptides involved in regulating body salt and water homeostasis.