resumo: Este trabalho se fundamenta na teoria dos custos de transação (TCT) para analisar o comportamento oportunístico dos fornecedores em compras públicas de produtos agropecuários fornecidos pelo setor privado. Argumenta-se que dentre as modalidades de compras públicas, o pregão eletrônico, embora utilize os princípios do leilão inglês reverso e seja considerado como uma estrutura de mercado regida pelo preço, apresenta comportamentos oportunísticos no momento do lance pelo vendedor, até o fechamento do contrato com o comprador. Foram analisadas as diferenças de cotações de preços e do preço de fechamento de 20 produtos agropecuários adquiridos em pregão eletrônico de processos de licitação pública em comparação aos preços licitados e de referências entre os anos de 2014 a 2017 no Instituto Federal Sul de Minas – Campus Inconfidentes. Os resultados permitem verificar que ocorreu um desconto nas licitações entre os anos de 2014 e 2017, visto que a repetição de lances em pregões forçou a redução de preços por parte dos fornecedores. Todavia, foi possível constatar oportunismos por parte de alguns agentes, nos itens em que o órgão público em estudo não especificou de forma completa o produto licitado.

abstract: This study is based on the theory of transaction costs (TCT) to analyze the opportunistic behavior of suppliers in public purchases of agricultural products provided by the private sector. We argue that among the public purchasing modalities, the electronic auction, although using the principles of the reverse English auction and considered as a market structure governance driven by price, presents opportunistic behavior at the time of bidding by the seller, until the closing of the contract with the buyer. We analyzed the differences in price quotations and the closing price of 20 agricultural products purchased in electronic auction of public bidding processes in comparison to the bid prices and of references between the years 2014 to 2017 in the Federal Institute Sul de Minas - Campus Inconfidentes. The results show that there was a discount in the biddings between the years 2014 and 2017, since the repetition of bids in electronic auction forced the reduction of prices by the suppliers. However, it was possible to note opportunism by some agents, in the items in which the public agency under study did not fully specify the bidding product.

Abstract In live organisms, there is a balance between the production of reactive oxygen species (ROS) and their neutralization. The increased level of these species leads to a condition called redox imbalance. The aim of this study was to evaluate the protective action of isobenzofuranones in primary cultures of hippocampal neurons subjected to redox imbalance. To accomplish this, MTT and LIVE/DEAD assays were initially performed. In the cultures pretreated with isobenzofuranones 1 and 2, there was a higher number of live cells when compared to that in the untreated ones. Regarding redox imbalance, there was a significant increase in the intracellular levels of ROS. The cultures pretreated with isobenzofuranones showed a reduction in ROS levels. Lipid peroxidation caused by oxidative damage was significantly reduced in the cultures pretreated with isobenzofuranones 1 and 2. Taken together, these data show the ability of isobenzofuranones 1 and 2 to significantly minimize cytotoxicity, cell death, intracellular levels of ROS and lipid peroxidation induced by redox imbalance. These results suggest that isobenzofuranones 1 and 2 represent a possible alternative therapy for the neurodegenerative disturbances that are triggered by ROS production increases.

Resumo Objetivo Há comprovação do importante papel das alterações no sistema imunológico no desencadeamento e manutenção da síndrome nefrótica idiopática (SNI). O objetivo deste estudo foi investigar a expressão das citocinas em populações de linfócitos de pacientes com SNI em comparação a indivíduos saudáveis e de acordo com a proteinúria. Métodos Este estudo transversal incluiu 44 pacientes com SNI e oito crianças saudáveis, pareados por idade e sexo (controles). Os pacientes foram subdivididos de acordo com a proteinúria: proteinúria persistente ou remissão parcial (PP ≥ 300 mg/24 h, n = 17) e proteinúria baixa ou remissão completa (PB < 300 mg/24 h, n = 27). A análise ex vivo de leucócitos no sangue periférico por citometria de fluxo foi feita utilizando marcadores de superfície para linfócitos T, TCD4, TCD8, células natural killer (NK), linfócitos NKT e B. As frequências das citocinas intracelulares foram analisadas nessas células. Resultados A frequência dos linfócitos B, células NK e células NKT foi menor em pacientes com SNI do que nos controles, ao passo que os pacientes com SNI apresentaram maior frequência de células CD4+fator de necrose tumoral (TNF)-α+ do que nos controles. Os linfócitos T citotóxicos que expressam interferon (IFN)-γ foram menores nos pacientes com SNI do que nos controles. Os pacientes com PP mostraram maiores frequências de linfócitos T CD4 que expressam IFN-γ e TNF-α que os controles. Os linfócitos CD8 que expressam TNF-α apresentaram aumento no grupo com PP, em comparação aos com PB e os controles, apesar de as células CD8+IFN-γ+ serem mais baixas nos pacientes com PB e nos controles. Conclusão Com relação ao nível de proteinúria, os pacientes com SNI apresentaram aumento na expressão de TNF-α nos linfócitos CD4 e expressão reduzida de IFN-γ nos linfócitos CD8. A persistência da proteinúria foi associada a maiores níveis de marcadores inflamatórios.

Abstract Objective: There is evidence of an important role of immune system changes in the triggering and maintenance of idiopathic nephrotic syndrome (INS). The aim of this study was to investigate the expression of cytokines in lymphocyte populations of patients with INS in comparison to healthy individuals, according to proteinuria. Methods: This cross-sectional study included 44 patients with INS and eight healthy children, matched for age and sex (controls). Patients were subdivided according to proteinuria: persistent proteinuria or partial remission (PP ≥ 300 mg/24 h, n = 17) and low proteinuria or complete remission (LP < 300 mg/24 h, n = 27). Ex vivo analysis of peripheral blood leukocytes by flow cytometry was performed using surface markers for T-lymphocytes, TCD4, TCD8, natural killer (NK) cells, NKT, and B-lymphocytes. Frequencies of intracellular cytokines were analyzed in these cells. Results: The frequencies of B-lymphocytes, NK cells, and NKT cells were lower in INS than in controls, whereas INS patients had a higher frequency of CD4+tumor necrosis factor (TNF)-α+ cells than controls. Cytotoxic-T-lymphocytes expressing IFN-γ were lower in INS than in controls. Patients with PP showed higher frequencies of CD4-T-lymphocytes expressing IFN-γ and TNF-α than controls. CD8-lymphocytes expressing TNF-α were increased in PP group when compared with LP and controls, while CD8+interferon (IFN)-γ+ cells were lower than in LP and in controls. Conclusion: Regardless the level of proteinuria, INS patients had increased expression of TNF-α in CD4-lymphocytes and reduced expression of IFN-γ in CD8-lymphocytes. Persistence of proteinuria was associated with higher levels of inflammatory markers.

RESUMO Objetivo: Este estudo avalia a relação entre a reflexão ultrassônica e a densidade óssea de 14 amostras cilíndricas de osso cortical bovino (3,0 cm de espessura). Métodos: Foi realizada a aquisição de 20 sinais de reflexão ultrassônica por amostra (passo de 2,0 mm), ao longo da superfície óssea. O Coeficiente de Reflexão Integrado (IRC) de cada sinal foi comparado por Tomografia Computadorizada Quantitativa (QCT). Resultados: Sete curvas de IRC e QCT apresentaram valor de Correlação R de Pearson acima de 0,5. Para curvas de correlação fraca, QCT e IRC apresentaram tendências semelhantes em vários segmentos. Conclusão: O IRC foi sensível à variação da densidade óssea. Nível de evidência: Estudo Experimental, Investigação de Exame Diagnóstico.

ABSTRACT Objective: This work evaluates the relationship between ultrasonic reflection and bone density from fourteen cylindrical bovine cortical bone samples (3.0-cm thick). Methods: Twenty US reflection signals per sample were acquired along the bone surface (2.0-mm step). The Integrated Reflection Coefficient (IRC) from each signal was compared to Quantitative Computed Tomography (QCT). Results: Seven IRC and QCT curves presented Pearson's Correlation R-values above 0.5. For weak correlation curves, QCT and IRC showed similar trends in several segments. Conclusion: IRC was sensitive to bone density variation. Level of Evidence: Experimental Study, Investigating a Diagnostic Test.

AbstractIntroduction: Ultrasound (US) is a nonionizing radiation capable of real time imaging at low cost. Its most attractive application is quantitative tissue characterization with the objective of differentiating normal tissues from diseased tissues. In this study, an automated method using singular spectrum analysis (SSA) to estimate the mean scatterer space (MSS) of US signals is proposed. Methods Entropy was used to determine the optimal number of components for the SSA. Subsequently, this number was compared with the results using a fixed number of components. A method based on the spectrum of the original signal was also used for comparison. The method was evaluated by using 24,000 simulated US signals, i.e., echoes and jitters backscattered from samples with different ratios of regular-to-irregular structure, as well as with 152 signals obtained from a phantom made of nylon wires. Results For the simulated signals, the proposed method for estimating the MSS presented results similar to the other methods that were tested. However, the magnitude-of-the-spectrum method loses the phase information, and hence, does not allow the characterization of irregular structures. For the signals recorded from the phantom, the methods using SSA and entropy achieved better results. Conclusion In this study, the combination of SSA with entropy to estimate the MSS of a periodic or quasi-periodic medium was proposed. The proposed method achieved similar or better results compared with two other methods found in the scientific literature. The novelty of the proposed method is the application of entropy as a quantitative criterion for selecting the SSA periodic components, allowing it to become independent of heuristic criteria.

Abstract Introduction Therapeutic ultrasound (TUS) is a widespread modality in physiotherapy, and the water bag technique is a coupling method employed in the presence of anatomical irregularities in the treatment area. The aim of the present study is to evaluate the acoustic attenuation of the water bag and its effectiveness as a TUS coupling agent. Methods The rated output powers (ROPs) of the TUS equipment were evaluated based on IEC 61689. Then, a radiation force balance was used to measure ROP with and without a water bag (latex and nitrile gloves filled with deionized water) between a TUS transducer and the cone-shaped target of the balance. Each experiment was performed five times for each nominal power (0.5, 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, and 7.0 W) and in the following configurations: without the water bag (A), with nitrile gloves and with (B) and without (C) a height controller, and latex gloves with (D) and without (E) height controller. ROPs obtained in different media were compared. Results The highest relative error of ROP was 16.72% for 0.5 W. Although the power values of the equipment were within the range recommended by IEC, there was a significant difference between the ROP values measured with A and with B, C and D. Conclusion As intensity differences below 0.5 W/cm2 are considered clinically not relevant, conditions A, B, C, D, or E can be used interchangeably.

Leatherback turtles (Dermochelys coriacea) have declined dramatically in the eastern Pacific Ocean (EP) in recent decades. Traditionally, population assessments have relied on the numbers of turtles on the beaches with the highest abundance of turtles (index beaches) and often disregarded the importance of nesting beaches with smaller, but still regular, numbers of nesting turtles (secondary beaches). We characterize leatherback nesting on secondary beaches throughout Pacific Costa Rica. Nesting distribution was significantly reduced since the 1990s and it currently appears to be constricted to the Santa Elena and Nicoya peninsulas. Over the past five years, nesting abundance on secondary beaches was low, ranging between 0.4 ± 0.5 and 5.3 ± 1.5 females and 3.8 ± 5.2 and 22.8 ± 10.8 nests per beach and per year. There was some exchange of turtles between beaches. The exchange rate (percentage of females that nested at least once on a different beach) ranged between 7% and 28%. While Caletas still registers multiple clutches that are laid by 1 -2 females in some years, it may no longer qualify as a secondary beach due to the infrequent nature of nesting events registered recently and the total absence of nests in some of those years. Although nesting abundance is relatively low at secondary beaches, they host at least ~25% of total leatherback nesting abundance in Costa Rica. As the EP leatherback turtle declines, not only do the numbers of nesting turtles decrease but local extirpations are occurring on, previously categorized, secondary beaches. The critically low number of turtles at present may prevent recolonization of sites where they have been extirpated.

Abstract Introduction The use of tools for computer-aided diagnosis (CAD) has been proposed for detection and classification of breast cancer. Concerning breast cancer image diagnosing with ultrasound, some results found in literature show that morphological features perform better than texture features for lesions differentiation, and indicate that a reduced set of features performs better than a larger one. Methods This study evaluated the performance of support vector machines (SVM) with different kernels combinations, and neural networks with different stop criteria, for classifying breast cancer nodules. Twenty-two morphological features from the contour of 100 BUS images were used as input for classifiers and then a scalar feature selection technique with correlation was used to reduce the features dataset. Results The best results obtained for accuracy and area under ROC curve were 96.98% and 0.980, respectively, both with neural networks using the whole set of features. Conclusion The performance obtained with neural networks with the selected stop criterion was better than the ones obtained with SVM. Whilst using neural networks the results were better with all 22 features, SVM classifiers performed better with a reduced set of 6 features.

Abstract Introduction Various signal-processing techniques have been proposed to extract quantitative information about internal structures of tissues from the original radio frequency (RF) signals instead of an ultrasound image. The quantifiable parameter called the mean scatterer spacing (MSS) can be useful to detect changes in the quasi-periodic microstructure of tissues such as the liver or the spleen, using ultrasonic signals. Methods We evaluate and compare the performance of three classic methods of spectral estimation to calculate the MSS without operator intervention: Tufts-Kumaresan, SAC (Spectral Autocorrelation) and MUSIC (MUltiple SIgnal Classification). Initially the evaluations were performed with 10,000 signals simulated from a model in which the variables of interest are controlled, and then, real signals from sponge phantoms were used. Results For the simulated signals, the performance of all three methods decreased with increasing Ad or jitter levels. For the sponges, none of the methods accurately estimated the pore size. Conclusion For the simulated signals, Tufts-Kumaresan had the lowest performance, whereas SAC and MUSIC had similar results. For sponges, only Tufts-Kumaresan was able to detect the increase in the size of the pores of the sponge, although most often, it estimated sizes larger than expected.

ABSTRACT Eriosema campestre var. macrophylum (Grear) Fortunato, Fabaceae, is a native plant of the Brazilian Cerrado and the decoction of its roots has been used by folk medicine for the therapy of inflammatory diseases. In this study we aimed to investigate the effect of the dichloromethane–ethanolic extract of E. campestre roots on the proliferative response of lymphocytes and to examine the profile of IL-2 production. The effect of dichloromethane–ethanolic extract of E. campestre on the proliferation of phytohemagglutinin-stimulated lymphocytes was evaluated by using flow cytometry and the cell supernatants were assayed for IL-2 concentrations by using an enzyme-linked immunosorbent assay. The phytochemical screening of E. campestre roots was performed to determine the main secondary metabolites through chromogenic and precipitation reactions and by using HPLC-PAD. In addition to the presence of subclasses of flavonoids (flavones and flavonols) in dichloromethane–ethanolic extract of E. campestre, we observed that the extract induced a concentration-dependent decrease in IL-2 levels on the supernatant of the cell cultures as well as an antiproliferative effect on T lymphocytes, including CD4+ and CD8+ cells. The anti-inflammatory effects attributed to E. campestre by folk medicine may partly be explained by its antiproliferative action on T lymphocytes.

PURPOSE: To determine the effectiveness of low-intensity therapeutic ultrasound (LITUS) on wound healing in rats with third-degree burns. METHODS: Twenty rats were divided into the Control Group that comprised four rats without third-degree burns that did not undergo LITUS, the Burned Group (BG), comprising eight rats with third-degree burns that did not undergo LITUS, and the Burned with Treatment Group (BTG), comprising eight rats with third-degree burns that were administered LITUS. LITUS began 24 h after injury and involved daily applications for 8 min at 0.1 W/cm2 for 14 days. RESULTS: The BTG lost less weight than the BG (Q=2.75; p<0.05). No visible differences were apparent among the groups' lesions on day 4. By the end of treatment, wound healing was more evident in the BTG. No statistically significant differences were found between the BG and the BTG in relation to the parameters measured using the histological changes in burn wound healing scoring system. CONCLUSION: The LITUS protocol applied to the animals with third-degree burns accelerated the formation of fibrin-leukocyte crusts and significantly reduced weight loss. However, burn wound healing was not accelerated.

Resumen El tiburón ballena (Rhincodon typus), es el condrictio viviente más grande del mundo, con una distribución cosmopolita, encontrándose tanto en mares tropicales como subtropicales. La Unión Mundial para la Conservación (IUCN) lo clasifico como vulnerable y con una tendencia poblacional en disminución, conocido por realizar grandes agregaciones alrededor del mundo, relacionadas a procesos oceanográficos que incrementan la productividad primaria del ambiente marino. Por primera vez, se reporta cuatro eventos de alimentación de tiburón ballena dentro de la cuenca interna de Golfo Dulce, un fiordo tropical ubicado en la costa del Pacífico Sur de Costa Rica. Los avistamientos fueron realizados en enero y agosto del 2009, marzo 2012 y enero del 2013, donde la estructura y tamaño de los grupos se mantuvo constante en el tiempo encontrándose una proporción similar de adultos y juveniles. Estas agregaciones fueron observadas en la costa occidental de Golfo Dulce en un área que abarcaba los 23km, cerca de los ríos Rincón y Tigre, siendo estos los responsables de una alta concentración de nutrientes que favorecen la presencia de comunidades planctónicas. Durante las agregaciones se observó la presencia de zooplancton en la columna de agua, copépodos (Orden: Calanoidea). Dada la vulnerabilidad del tiburón ballena, es de suma importancia la implementación de estrategias de manejo de las actividades antropogénicas que se desarrollan en el Golfo, como son las actividades turísticas, desarrollo costero, aumento del tráfico marítimo, y la pesca comercial y deportiva, que ponen en riesgo a esta especie bandera.

Abstract The zooplanktivorous whale shark (Rhincodon typus), is the largest living chondrichthyan and a cosmopolitan species, living in tropical, warm and temperate waters. It is considered vulnerable by the International Union for Conservation of Nature (IUCN), and is known for big aggregations in many parts of the world. These are associated with particular oceanographic features where primary productivity is thought to be high. For the first time, four whale shark feeding aggregations are documented in Golfo Dulce, Costa Rica, a tropical fjord-like embayment located in the south Pacific region of the country. Observations were made in January and August 2009, March 2012 and in January 2013, Estimated group structure and size remained constant over time with an equal proportion of adults and juveniles in the same area. These aggregations were observed on the north-western coast of Golfo Dulce’s inner basin, close to the Rincón and Tigre rivers. These two rivers are known to provide organic material which area important nutrients for the gulf zooplanktonic communities. During one of the observed feeding aggregations, copepods (Order: Calanoida) were seen in the water close to feeding individuals. Given the vulnerability of whale sharks, management decisions for Golfo Dulce need to include strategies to control tourism, boat circulation, commercial and sports fisheries and coastal development. Rev. Biol. Trop. 63 (Suppl. 1): 299-306. Epub 2015 April 01.

Resumen Golfo Dulce es un estuario en forma de fiordo, localizado en el Pacífico Sur de Costa Rica. Este ecosistema marino-costero contiene una importante biodiversidad marina que incluye cetáceos. Este estudio describe la estructura de la comunidad de cetáceos en Golfo Dulce, sustentado en la diversidad de hábitats. Datos sobre avistamientos colectados en muestreos periódicos sistemáticos, han resultado en 943 registros (2005-2014≈3 490h≈64 533km) de siete especies de la familia Delphinidae, una Balaenopteridae y una especie de la familia Kogiidae. Se observa un gradiente en la diversidad de cetáceos desde la cuenca interna de Golfo Dulce hasta la zona de transición- oceánica en la entrada al Golfo. La dominancia se establece por la forma costera del delfín nariz de botella y el delfín manchado en la cuenca interna, mientras que T. truncatus junto con ballenas jorobadas migrantes ejercen la dominancia en el área del Umbral. El área transicional oceánica sostiene la mayor diversidad, dominada por especies de delfínidos de naturaleza piscívora, incluyendo la forma oceánica del delfín nariz de botella y la subespecie “Centroamericana” del delfín tornillo. Nosotros proponemos la hipótesis de una forma potencial particular del delfín manchado pantropical para Golfo Dulce, en contraste con S. attenuatta graffmani en aguas abiertas costeras del Pacífico Costarricense. El patrón de la estructura comunitaria de cetáceos se establece por la dinámica en uso de área por las especies presentes, lo cual debería ser considerado para el diseño de estrategias de manejo y conservación.

Abstract Golfo Dulce is a fiord-lilke embayment located in the southern Pacific of Costa Rica, this coastal-marine ecosystem harbors an important wealth in marine biodiversity, including cetaceans. In this study we describe the cetacean community of Golfo Dulce, in relation to the diversity of habitats constituting the seascape. Sighting data collected in periodic systematic surveys has yielded 943 records (2005-2014≈3 490h≈64 533km), of 12 species of cetaceans. A gradient of cetacean diversity is observed from the inner basin to the transitional-oceanic area at the entrance of the Gulf, with coastal bottlenose dolphin and spotted dolphin dominating the inner basin, and bottlenose dolphins and migratory humpback whales the sill area. Transitional oceanic habitat holds the greatest species diversity dominated by oceanic species, particularly piscivorous delphinids, including the off-shore form of bottlenose dolphins and the “Central American” spinner dolphin. We hypothesize the potential occurrence of a morphotype of pantropical spotted dolphins within Golfo Dulce, in contrast with S. attenuatta graffmani outside in open Pacific coastal waters. The pattern of cetacean community structure is established by the dynamic of area use by the species, which should be considered for the establishment of management and conservation strategies. Rev. Biol. Trop. 63 (2): 395-406. Epub 2015 June 01.

RESUMO O presente estudo teve como objetivos: (i) determinar, in vitro, o efeito da temperatura sobre o crescimento micelial (10 a 35oC) e a germinação de conídios (10 a 45oC) de Corynespora cassiicola ; (ii) avaliar, in vitro , o efeito do regime de luz (luz contínua, fotoperíodo de 12 h e escuro) sobre o crescimento micelial, a esporulação e a viabilidade dos esporos de C. cassiicola ; e (iii) verificar, in vivo , a influência da temperatura (20 a 30oC) e da duração do período de molhamento foliar (4 a 48 h) no desenvolvimento da mancha-alvo em folhas de acerola. As temperaturas ótimas, estimadas a partir das equações, para o crescimento micelial e a germinação de esporos foram de 30 e 29oC, respectivamente. O regime de luz não afetou o crescimento micelial e a germinação dos esporos, entretanto, luz contínua favoreceu a esporulação, e a ausência de luz durante a produção dos esporos diminuiu sua viabilidade. Houve um incremento na área das lesões da mancha-alvo em folhas de acerola conforme a temperatura aumentou até 30oC. Foram necessárias 12 h de molhamento foliar para que a infecção e as lesões ocorressem.

ABSTRACT The objective of this study were: (i) to assess, in vitro , the effect of temperature on mycelial growth (10-35oC) and spores germination (10-45oC); (ii) to evaluate, in vitro¸the effect of the light regime (continuous light, 12 h photoperiod and continuous darkness) on mycelial growth, sporulation and viability of the spores of C. cassiicola ;and (iii) to assess, in vivo,the effect of temperature (20-30oC) and the duration of leaf wetness (4-48 h) in the development of target spot in leaves of barbados cherry. The estimated maximum temperatures for mycelia growth and spore germination were 30 and 29oC, respectively. The light regime did not affect the mycelial growth and spores germination. However, continuous light regime favored the sporulation, and the absence of light during spore production decreased the spore viability. The target spot lesions area in barbados cherry leaves increased with the increment in the temperature up to 30oC. Twelve hours of leaf wetness were necessary for the infection and lesion development of target spot.