Experimental observation of a complex periodic window

The existence of a special periodic window in the two-dimensional parameter space of an experimental Chua's circuit is reported. One of the main reasons that makes such a window special is that the observation of one implies that other similar periodic windows must exist for other parameter values. However, such a window has never been experimentally observed, since its size in parameter space decreases exponentially with the period of the periodic attractor. This property imposes clear limitations for its experimental detection.Comment: 4.2 pages, 4 figure

Fisiologia e composição morfológica de dois híbridos de sorgo submetidos a duas frequências de pastejo com ovinos.

Resumo: A sazonalidade da produção de forragem em regiões semiáridas consiste num dos principais entraves à produção de ruminantes a pasto. A utilização de plantas forrageiras tolerantes à restrição hídrica, que reduza a sazonalidade na produção de forragem, consiste em estratégia factível para viabilizar a pecuária a pasto nessas regiões. Objetivou-se avaliar as trocas gasosas, os índices de crescimento e a composição morfológica e botânica de dois híbridos de sorgo para pastejo submetidos a duas frequências de pastejo com ovinos. Adotou-se um arranjo fatorial 2x2 num delineamento inteiramente casualizado com quatro repetições. Os tratamentos consistiram da combinação entre dois híbridos de sorgo para pastejo (?Sorghum bicolor x S. sudanense?) e duas frequências de pastejo (60 e 80 cm de altura pré-pastejo), com ovinos da raça Morada Nova, manejados sob lotação rotativa. Para o ensaio de trocas gasosas constatou-se interação para os fatores estudados (P0,05) para os fatores estudados. Para o ensaio da análise de crescimento, obteve-se ajuste dos modelos testado para o efeito da idade de crescimento durante o período de descanso. O índice de área foliar, razão de peso foliar, taxa de assimilação líquida e taxa de crescimento relativo apresentaram comportamento linear. A razão de área foliar foi minimizada aos 11,45 dias para o BRx60 e maximizada aos 19,83 dias para o BRx80, não revelando significância para CMx60 (0,0407 ± 0,01) e CMx80 (0,0248 ± 0,09). Para a composição morfológica do dossel, observou-se maior percentual de lâminas foliares na camada superior a 31 cm para a combinação CMx60. Houve aumento no percentual de colmo e material morto, e na ocorrência de plantas daninhas a partir de 31 cm de altura, para as combinações BRx80 e CMx80. A combinação BRx60 apresentou maior eficiência fotossintética e a combinação CMx60 maior eficiência de crescimento. O manejo com 60 cm de altura pré-pastejo proporcionou maior percentual de lâminas foliares verdes ao longo do perfil do dossel. Abstract: The seasonality of forage production in semi-arid regions is one of the main barriers to grass-fed ruminant production. The use of forage plants tolerant to water restriction, that reduces the seasonality in forage production, is a feasible strategy to enable pasture farming in these regions. The objective in this study was to evaluate the gas exchange, growth rates and morphological and botanical composition of two sorghum hybrids submitted to two grazing frequencies using sheep. A 2x2 factorial arrangement was adopted in a completely randomized design with four replicates. The treatments consisted of the combination of two sorghum hybrids (?Sorghum bicolor x S. sudanense?) and two grazing frequencies (60 and 80 cm of height pre-grazing), using Morada Nova sheep, managed under rotational stocking. For the gas exchange trial, interaction was observed between the factors studied (P0.05) for the factors studied. For the growth analysis trial, the adjustment of the tested models was obtained for the effect of growth age during the rest period. Leaf area index, leaf weight ratio, net assimilation rate and relative growth rate showed linear behavior. The leaf area ratio was minimized at 11.45 days for BR60 and maximized at 19.83 days for BR80, showing no statistical significance for CM60 (0.0407 ± 0.01) and CM80 (0.0248 ± 0.09). For the morphological composition of the canopy, a greater percentage of leaf blades was observed in the upper layer at 31 cm for the CM60 combination. There was an increase in the percentage of stem and dead material, and in the occurrence of weeds from 31 cm in height, for the combinations BR80 and CM80. The BRx60 combination showed higher photosynthetic efficiency and the CMx60 combination had higher growth efficiency. The management with 60 cm of pre-grazing height favored a greater proportion of green leaf blades along the canopy profile.Dissertação (Mestrado em Zootecnia. Área de concentração: Nutrição Animal e Forragicultura) - Universidade Federal do Ceará, Fortaleza. Orientador: Magno José Duarte Cândido; Coorientador: Roberto Cláudio Fernandes Franco Pompeu (CNPC)

Nanotechnology for the treatment of deep endometriosis: uptake of lipid core nanoparticles by LDL receptors in endometriotic foci

OBJECTIVE: Rapidly dividing cells in multiple types of cancer and inflammatory diseases undergo high low density lipoprotein (LDL) uptake for membrane synthesis, and coupling an LDL-like nanoemulsion, containing lipid nanoparticles (LDE) to a chemotherapeutic agent efficiently targets these cells without significant systemic effects. This was a prospective exploratory study that evaluated the uptake of a radioactively labeled LDE emulsion by receptors of endometriotic foci and the capacity of the LDE for cellular internalization. METHODS: The lipid profile of each patient was determined before surgery, and labeled LDE were injected into fourteen patients with intestinal or nonintestinal endometriosis. The radioactivity of each tissue sample (intestinal endometriosis, nonintestinal endometriosis, healthy peritoneum, or topical endometrium) was measured. RESULTS: The group with intestinal endometriosis presented higher levels of plasma LDL but lower LDE uptake by foci than the nonintestinal group, suggesting less cell division and more fibrosis. The uptake of LDE was highest in the topical endometrium, followed by the healthy peritoneum, and lowest in the endometriotic lesion. Since the endometriotic foci showed significant LDE uptake, there was likely increased consumption of LDL by these cells, similar to cells in cancers and inflammatory diseases. Plasma cholesterol levels had no influence on LDE uptake, which showed that the direct delivery of the nanoemulsion to target tissues was independent of serum lipoproteins. There were no significant differences in the parameters (p40.01) because of the small sample size, but the findings were similar to those of previous studies. CONCLUSION: Nanotechnology is a promising therapeutic option for surgery and hormonal blockage for deep endometriosis, with a lower complication rate and no systemic side effects

DRIS standards for nutritional evaluation of Phaseolus vulgaris in Cerrado, Goiás State, Brazil.

The knowledge of nutritional requirements of beans, the efficiency of soil acidity correction and the fertilization programs are essential to increase productivity. The Integrated Recommendation and Diagnosis System (DRIS) assists with nutritional diagnosis of cultivated plants based on existing interactions between nutrients and the hierarchizing of limitations. This study aimed at establishing standards using the DRIS method for areas of production of irrigated common beans and at determining the most limiting nutritional factors to production using leaf analyses interpreted by concentration ranges and DRIS. Eighteen different beanproducing areas were selected in a central pivot irrigation system, from which 82 sampling points were established to collect leaves of crop and determine their nutritional contents. The reference population had productivity of over 3,000 kg ha- 1. Using DRIS, we determined that phosphorus is the most limiting nutrient regarding its deficiency, with great sensitivity to diagnose nutritional problems of plants, especially micronutrients. Phosphorus (68.3%), molybdenum (65.9%), iron (64.6 %) and sodium (63.4%) and are nutrients with highest percentage of samples presenting levels below adequate according to sufficiency ranges for plants. Using DRIS, we can evaluate interactions among nutrients and determine of the magnitude of crop nutritional limitation whether due to deficiency or excess. These results may indicate which nutrients are limiting the crop productive capacity, allowing greater efficiency in its correction in soil

Determination of Cd and Pb in fuel ethanol by filter furnace electrothermal atomic absorption spectrometry

A method was developed for quantification of Cd and Pb in ethanol fuel by filter furnace atomic absorption spectrometry. Filter furnace was used to eliminate the need for chemical modification, to stabilize volatile analytes and to allow the application of short pyrolysis step. The determinations in samples were carried out against calibration solutions prepared in ethanol. Recovery tests were made in seven commercial ethanol fuel samples with values between 90 and 120%. Limits of detection were 0.1 µg L-1 for Cd and 0.3 µg L-1 for Pb. Certified water samples (APS 1071, APS 1033, NIST 1643d, NIST 1640) were also used to evaluate accuracy and recoveries from 86.8% to115% were obtained

Índices de crescimento em capim-paraíso sob diferentes idades durante três ciclos de crescimento no litoral cearense.

Resumo: As forrageiras apresentam variação ao longo do seu crescimento, em razão de variação na idade fisiológica e das condições de meio e manejo. Objetivou-se avaliar os índices de crescimento em capim-paraíso em diferentes idades de crescimento (14; 21; 28; 35; 42; 49; 56; 63 e 70 dias) e durante três ciclos (chuvoso, seco 1 e seco 2), num delineamento inteiramente casualizado com medidas repetidas no tempo e duas repetições. Avaliaram-se a taxa de crescimento relativo (TCR), a razão de área foliar (RAF), a razão de peso foliar (RPF) e a área foliar específica (AFE). A interação entre idades de crescimento e ciclos foi significativa para todas as variáveis analisadas, exceto para a AFE. A TCR decresceu com as idades em ambos os ciclos, exceto no ciclo seco 2, com média de 0,0512 g?g-1?dia-1. A RAF e a RPF decresceram com o avanço nas idades. A AFE respondeu positivamente às idades. As idades de crescimento influenciam a dinâmica dos componentes morfofisiológicos do capim-paraíso. [Growth index in paraiso grass under different ages during three growth cycles in coastal Ceara]. Abstract: The forage plants show variation along their growth due to changes in physiological age, environment and management conditions. One aimed to analyze the growth index of paraiso grass, in different growth ages (14; 21; 28; 35; 42; 49; 56; 63 e 70 days) and cycles (rainy, dry 1 and dry 2). A completely randomized design in a split-plot layout with repeated measures and two replicates was adopetd. The relative growth rate (RGR), the leaf area ratio (LAR), the leaf weight ratio (LWR) and the specific leaf area (SLA) were evaluated. An interaction between growth ages and cycles was observed for all variable analyzed, except for SLA. The RGR showed a linear decreased effect in the cycles, except in dry 2 cycles, with an average of 0,0512 g?g-1?day-1. The LAR and LWR decreased along the ages. The SLA presented positive linear effect. The different growth ages influenced the morphofisiological components in paraiso grass

Cactus Forage Productivity Modelling Using PHYGROW Software in a Semiarid Environment

Plant growth modeling has been shown an increasing strategy to cope with the high demand for food supply, mainly in climate vulnerable areas, providing them to be used in agriculture worldwide. Concerning semiarid regions, the PHYGROW software has been promising to model plant growth, as cactus forage (‘Opuntia stricta’ cv. “Mexican elephant ear”) which was used in this study. Production data from 2017 and 2018 in Petrolina, Permambuco state, Brazil, with 12 replicates each year were considered. This region shows a very hot and dry climate and has an erratic and seasonal rainfall, which varies a lot in quantity, frequency and intensity from one year to another. After the PHYGROW software parameterization, we performed the generation of the synthetic series and, afterwards, we add the field data to calibration and validation. The results showed a high prediction capacity of PHYGROW software, even in such an erratic climate as Brazilian Semiarid, considering the model performed as calibrated. In 2017 and 2018, the observed cactus forage biomass were 1745 ± 505.83 and 2016 ± 584.58 kg DM ha-1 and the estimated data were 1795 and 2314 kg DM ha-1, respectively. This relatively high deviation suggests an opportunity to add more data, in order to get the model more accurate. Although there was a high difference in precipitation from 2017 to 2018 (166 and 301 mm, respectively), cactus forage was capable to offset this fluctuation, which makes it a strategic resource to reduces the biomass variation and stockpiling necessity on the farm level. This study also demonstrated the importance of modelling to help the farmer to cope with the weather and feed variation in climate vulnerable areas, allowing them to anticipate and adopt strategies to cope with drought more efficiently