598 research outputs found

    Periodic Neural Activity Induced by Network Complexity

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    We study a model for neural activity on the small-world topology of Watts and Strogatz and on the scale-free topology of Barab\'asi and Albert. We find that the topology of the network connections may spontaneously induce periodic neural activity, contrasting with chaotic neural activities exhibited by regular topologies. Periodic activity exists only for relatively small networks and occurs with higher probability when the rewiring probability is larger. The average length of the periods increases with the square root of the network size.Comment: 4 pages, 5 figure

    Chemical ecology of echinoderms: Impact of environment and diet in metabolomic profile

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    The phylum Echinodermata constitutes a successful and widespread group comprising Asteroidea, Ophiuroidea, Echinoidea, Holothuroidea and Crinodeia. Nowadays, marine organisms are being given a lot of attention in drug discovery pipelines. In these studies, sponges and nudibranchs are frequently addressed, however an increasing number of works focus their attention in echinoderms. Given the fact that many of the bioactive molecules found in echinoderms are diet-derived, different feeding behavior and surrounding environment plays a critical role in the chemical composition of echinoderms. In this work, the most relevant chemical classes of small molecules present in echinoderms, such as fatty acids, carotenoids and sterols will be addressed. When data is available, the influence of the environment on the chemical profile of these organisms will be discussed.(undefined

    Influence of storage conditions on fruit quality of ‘Royal Time’ and ‘Royal Summer’ peach cultivars

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    Peach is a very perishable climacteric fruit whose firmness may decay rapidly depending on the temperature. Refrigeration is usually used to delay ripening and maintain fruit quality. However, often temperature storage conditions are not optimized. This work aims to characterize the storage conditions (temperature and humidity) of three peach producers of Beira Interior region, Portugal. Additionally, correlate those conditions with peach quality evolution comparing two peach cultivars – Royal Summer and Royal Time – with similar harvest dates but very different acidity content. The three refrigeration chambers monitored have very distinct conditions of average air temperature, namely 8.29±3.53 °C (local C), 5.50±0.88 °C (local G) and 0.80±0.83 °C (local L) but similar high humidity, in an average range of 90%-98%. At harvest time, major differences were in fruit firmness and acidity. ‘Royal Summer’ firmness was 6.61 kgf and ‘Royal Time’ was 5.20 kgf. For all storage conditions, fruit firmness decrease faster for ‘Royal Time’ cultivar than for ‘Royal Summer’. The results suggest that in general farmers use inadequate range temperature for long storage period. For short periods of 7 days, conditions like those of local G allow fruit quality maintenance like firmness and loss of weight without problems of chilling injury, and, simultaneously, save energy that is also not only a desirable international goal but also contributes to decrease of production costs.O pêssego é um fruto climatérico, altamente perecível, cuja firmeza diminui rapidamente dependendo da temperatura de conservação. A refrigeração é o processo utilizado para atrasar a maturação e manter a qualidade embora, em muitos casos, a temperatura de refrigeração não seja otimizada. Este trabalho pretende caracterizar as condições de refrigeração (temperatura e humidade) das câmaras de três produtores de pêssego da Beira Interior. Adicionalmente, pretende também relacionar essas condições com a evolução da qualidade dos frutos utilizando duas cultivares – Royal Summer e Royal Time – com data de colheita semelhante, mas teor de acidez distinto. As três câmaras de refrigeração monitorizadas corresponderam a condições bastante diferentes de temperatura, nomeadamente, 8,29±3,53°C (local C), 5,50±0,88°C (local G) e 0,80±0,83°C (local L), mas semelhantes em termos de humidade, que está compreendida entre 90% e 98%. À colheita, as maiores diferenças observadas foram a firmeza e acidez. A firmeza dos pêssegos da ‘Royal Summer’ foi de 6,61 kgf e a da ‘Royal Time’ foi de 5,20 kgf. Para todas as condições de conservação, a firmeza diminuiu mais rapidamente na ‘Royal Time’. Os resultados sugerem que, em geral, os produtores usam intervalos de temperatura inadequados para períodos de conservação longos. Contudo, considerando períodos curtos, entre 7 dias, as condições observadas no local G permitiram manter a qualidade como firmeza e perda de peso, sem se observarem danos por frio. Simultaneamente, permitem economizar energia o que é um objetivo internacional e contribui para a diminuição dos custos de produção.This research work is part of project “PrunusPÓS – Otimização de processos de armazenamento, conservação em frio e embalamento inteligente no pós-colheita de pêssego e cereja”, n.º PDR2020-101-031695 (PDR 020), Portugal 2020. The authors would like to thank the producers who allowed the use of the refrigeration chambers and the respective monitoring of its conditions.info:eu-repo/semantics/publishedVersio

    Comparative assessment of atmospheric correction of Landsat imagery using Modtran and dark object subtraction.

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    Remote sensing by spectral imaging of the Earth's surface can be widely used, but only when the atmospheric influence is nullified and the data are reduced to surface reflectance units. The atmospheric correction referred to here is an atmospheric "compensation" or "characterization" in which algorithms are used in remote sensing applications for hyper and multispectral images to correct atmospheric propagation effects in measurements taken by airborne and orbital systems. The remission of atmospheric effects guarantees the identification of biophysical properties of the targets and their isonomic relationship with spectroradiometric databases, thus enabling the application of sophisticated classification methods such as linear Spectral Mixture Analysis models (SMA) and Spectral Indexes. Based on this premise, the objective of this article is to compare the atmospheric correction used in the MODTRAN model with that used in the Dark Object Subtraction (DOS1) and Improved Dark Object Subtraction (DOS2) models in order to verify which approach shows better correspondence with reference spectral libraries. We used spectral data on tropical soils obtained using the spectroradiometer (FieldSpec Full Resolution). Due to the difficulty in obtaining data on atmospheric conditions, especially for tropical regions, and the difficulty in accessing the most reliable correction procedures, corrections are sometimes disregarded or even based on extremely simple methods which may produce radiance and reflectance estimation errors even greater than tho se of the original images. MODTRAN presented the most consistent results, especially with regard to season variation and the presence of haze (low contrast) in some images due to the high aerosol concentration. This kind of atmospheric phenomenon is common in tropical regions, which shows the importance of considering local atmospheric correction parameters based on an atmosphere simulation model. Methods DO S1 and DOS2, in spite of their good performance in some of the analyzed areas, have not been effective in the suppression of effects related to atmospheric absorption. This work is one of the few that considers different test targets in a tropical environment with season variation

    Cisplatin, fluorouracil in bolus injection, and leucovorin in first-line therapy for advanced gastric cancer as an alternative to protocols with infusional fluorouracil

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    PURPOSE Gastric cancer (GC) is the fourth most common cancer and the second leading cause of cancer death worldwide. Platinum agents and fluoropyrimidines are the main compounds used in the first-line setting for advanced GC. Given the activity of fluorouracil (FU) bolus, the PFL protocol, a chemotherapy regimen combining cisplatin, FU bolus, and leucovorin, was incorporated at the Brazilian National Cancer Institute, because this schedule does not require hospitalization or infusion pumps. This study aims to evaluate the outcomes of PFL in the first-line setting for patients with advanced GC. MATERIALS AND METHODS This was a retrospective cohort study evaluating patients with advanced GC treated in the first-line setting with cisplatin 80 mg/m2 on day 1 and FU bolus 400 mg/m2 plus leucovorin 20 mg/m2 on days 1, 8, 15, and 22 every 4 weeks, from January 2008 to December 2014. RESULTS A total of 109 patients were enrolled. The median number of cycles received per patient was four (one to 11). Complete responses were achieved in 6.4% and partial responses in 14.7%. Median progression-free survival was 6.3 months (95% CI, 5.08 to 7.58 months) and median overall survival was 8.3 months (95% CI, 6. 79 to 9.87 months). Thirty-four (31.2%) patients were alive in 1 year. Grade 3 and 4 adverse events were experienced by 26.6% and 3.7% of patients, respectively, with dose reduction necessary in 9.1%. CONCLUSION PFL is active in advanced GC and could be an alternative for FU continuous infusion protocols in institutions with limited resources and/or low budget, which is the reality in many nations all over the world

    Raiva em herbívoros no estado do Pará, Brasil: estudo descritivo (2004 a 2013)

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    PARC/PROPESP and PAPQ/ PROPESPUniversidade Federal do Pará. Instituto de Medicina Veterinária. Laboratório de Epidemiologia e Geoprocessamento. Castanhal, PA, Brazil.Instituto Federal de Educação do Tocantins. Palmas, TO, Brazil.Universidade Federal do Pará. Instituto de Medicina Veterinária. Laboratório de Epidemiologia e Geoprocessamento. Castanhal, PA, Brazil.Universidade Federal de Mato Grosso. Graduate Program in Health Sciences. Sinop, MT, Brazil.Museu Paraense Emílio Goeldi - Campus de Pesquisa. Programa de Capacitação Institucional. Coordenação Ciências da Terra e Ecologia. Belém, PA, Brazil.Agência de Defesa Agropecuária do Pará. Belém, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Laboratório de Geoprocessamento. Ananindeua, PA, Brasil.Universidade Federal do Pará. Instituto de Medicina Veterinária. Laboratório de Epidemiologia e Geoprocessamento. Castanhal, PA, Brazil.Rabies is an important zoonosis to public health associated with lethal encephalitis and economic losses. Analysis of its spatial distribution is a meaningful tool in understanding its dispersion, which may contribute to the control and prophylaxis of the disease. This study analyzed the spatial-temporal distribution of rabies outbreaks in livestock in Pará state, Brazil, from 2004 to 2013. We used records of neurological syndromes obtained from the state’s livestock authority (Adepará). The analysis recorded 711 neurological syndromes reports in livestock, of which 32.8% were positive for rabies. In 8% of the neurological syndromes (n=57) was not possible to perform the analysis because of bad-packaging conditions of the samples sent. Outbreaks involved at least 1,179 animals and cattle were the most affected animal species (76.8%). The numbers of reported neurological syndromes and of rabies outbreak shad strong positive correlation and exhibited decreasing linear trend. Spatially, most outbreaks occurred in two mesoregions in Pará (Northeast and Southeast). One of the justifications for this spatial distribution may be related with the distribution of the animals in the state, since these mesoregions are the largest cattle producers in Pará and have most of their territory deforested for pasture implementation
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