Abstract Citrus bergamia is a citric species known as bergamot. The species is widely used due to its derivatives, such as juices, extracts, and essential oil. Specifically, the bergamot essential oil (BEO) is of great interest, with a chemical composition rich in terpenes and esters. Considering its chemical composition, bioactivity, and great economic potential, the characterization of BEO should be studied. However, this essential oil is almost unexplored in terms of a characterization associated with colloids. Chemical characterization was carried out by gas-chromatography coupled to a mass spectrometer and by gas-chromatography coupled to a flame ionization detector. Antibacterial activity against Staphylococcus aureus and Escherichia coli was carried out to confirm the bioactivity of this important essential oil. Dynamic light scattering analysis was performed to create a pattern of droplet size distribution of BEO. Major compounds of BEO were linalyl acetate, limonene, and linalool. The BEO was active against E. coli and presented a MIC value of 2.000 µg/mL, while values of MIC and MBC higher than 2.000 µg/mL were observed for S. aureus. The dynamic light scattering analysis revealed a mean hydrodynamic diameter of 65.7 ± 2.2 nm. After a 1:10 dilution it was observed reduction of mean diameter and enhancement of the percentagem of low size droplets, resepctively 44.1 ± 1.2 nm and 14.5 ± 0.5 nm (28.8 ± 1.2%). Higher droplets and reduced polydispersity index were observed after 1:100 dilution. In the present study, the chemical characterization was in accordance with the species, as the characteristic chemical markers of the species were found. Moreover, it has presented antibacterial activity as expected for the BEO. The analysis of the colloid showed a pattern of droplet size distribution following the Ostwald ripening mechanism after dilution. derivatives juices extracts Specifically (BEO interest esters potential studied However colloids gaschromatography gas chromatography detector acetate limonene linalool E 2000 2 000 2.00 µgmL µg mL S 657 65 7 65. 22 2. 110 1 10 1:1 441 44 44. 12 1. 145 14 5 14. 05 0 0. 28.8 288 28 8 (28. 1.2%. 1.2% . 1.2%) 1100 100 study found Moreover 200 00 2.0 6 11 1: 4 28. (28 20 (2 (

Resumo Citrus bergamia é uma espécie cítrica conhecida como bergamota amplamente utilizada industrialmente devido aos seus derivados, como sucos, extratos e óleo essencial. Especificamente o óleo essencial de bergamota (OEB) é de grande interesse, com uma composição química rica em terpenos e seus ésteres. Devido a sua composição química, bioatividade e grande interesse econômico, a caracterização do OEB deve ser alvo de estudos. No entanto, esse óleo essencial é praticamente inexplorado em termos de uma caracterização associada a coloides. Sua caracterização foi feita por cromatografia em fase gasosa acoplada à espectrômetro de massas e cromatografia em fase gasosa acoplada a detector de ionização de chamas. Atividade antibacteriana frente a Staphylococcus aureus e Escherchia coli foi realizada para confirmar a bioatividade do óleo essencial. Análise por espalhamento dinâmico da luz foi feita para criar um padrão de distribuição de tamanho de gotícula. Os constituintes majoritários foram o acetato de linalila, limoneno e linalool. O OEB foi ativo frente à E. coli, apresentando um valor de CMI igual à 2.000 µg/mL, enquanto values de CMI e CMB maiores do que 2.000 µg/mL foram observados frente à S. aureus.. A análise por espalhamento dinâmico da luz revelou um diâmetro hidrodinâmico médio de 65.7 ± 2.2 nm. Após diluição de 1:10, houve redução do diâmetro médio acompanhado de aumento do percentual de gotículas de baixo tamanho (14.5 ± 0.5 nm, 28.8 ± 1.2%). Foi observado aumento do tamanho e redução do índice de polidispersividade após uma maior diluição (1:100). Discussão: No presente estudo, a caracterização química está em consonância com a espécie, sendo encontrados os marcadores químicos da mesma. Além disso, o OEB apresentou a atividade antibacteriana esperada. A análise do coloide mostrou um padrão de distribuição de tamanho de gotícula de acordo com o mecanismo de Maturação de Ostwald após diluição. derivados sucos (OEB ésteres econômico estudos entanto coloides chamas linalila linalool E 2000 2 000 2.00 µgmL µg mL S aureus. 657 65 7 65. 22 2. nm 110, 110 1 10, 10 1:10 14.5 145 14 5 (14. 05 0 0. 288 28 8 28. 1.2%. 12 1.2% . 1.2%) 1100. 1100 100 (1:100) Discussão estudo mesma disso esperada 200 00 2.0 6 11 1:1 14. (14 1.2 (1:100 20 1: (1 1. (1:10 ( (1:1 (1:

We examined whether endurance performance and neuromuscular fatigue would be affected by caffeine ingestion during closed- and open-loop exercises. Nine cyclists performed a closed-loop (4,000-m cycling time trial) and an open-loop exercise (work rate fixed at mean power of the closed-loop trial) 60 min after ingesting caffeine (CAF, 5 mg/kg) or placebo (PLA, cellulose). Central and peripheral fatigue was quantified via pre- to post-exercise decrease in quadriceps voluntary activation and potentiated twitch force, respectively. Test sensitivity for detecting caffeine-induced improvements in exercise performance was calculated as the mean change in time divided by the error of measurement. Caffeine ingestion reduced the time of the closed-loop trial (PLA: 375.1±14.5 s vs CAF: 368.2±14.9 s, P=0.024) and increased exercise tolerance during the open-loop trial (PLA: 418.2±99.5 s vs CAF: 552.5±106.5 s, P=0.001), with similar calculated sensitivity indices (1.5, 90%CI: 0.7-2.9 vs 2.8, 90%CI: 1.9-5.1). The reduction in voluntary activation was more pronounced (P=0.019) in open- (-6.8±8.3%) than in closed-loop exercises (-1.9±4.4%), but there was no difference between open- and closed-loop exercises for the potentiated twitch force reduction (-25.6±12.8 vs -26.6±12.0%, P>0.05). Caffeine had no effect on central and peripheral fatigue development in either mode of exercise. In conclusion, caffeine improved endurance performance in both modes of exercise without influence on post-exercise central and peripheral fatigue, with the open-loop exercise imposing a greater challenge to central fatigue tolerance.

Abstract In this work, the electrochemical anodization process was carried out on titanium grade 2, using an electrolytic solution of 3 M and 0.15 M HCl with voltages of 11 V, 12 V and 15 V, as well as time variations in the experimental process and later an annealing process at 750 °C. According to the results obtained, the TiO2 coatings presented different morphologies on their surface, which consisted of nanopores, nanowires and clusters of oxide grains, as well as a combination of anatase and rutile crystalline phases. Band Gap variations were found to be non-significant despite changes in the morphology of the coatings at different anodization conditions, with an average value of 2.91 eV. It was observed that the anodized samples treated by the annealing process at 750 °C, thickness values up to 16 μm were obtained.

Resumen La termorregulación en la montaña tropical Andina impone retos para los reptiles. La interacción entre los requisitos térmicos de los individuos con las condiciones térmicas externas en estos entornos es poco conocida. Examinamos la estrategia de termorregulación de la serpiente nocturna Atractus crassicaudatus (Duméril, Bibron and Duméril, 1854), en el norte de los Andes. Describimos la relación entre la temperatura corporal de las serpientes, en campo y en laboratorio, con las temperaturas operativas durante 2 temporadas climáticas. Comparamos también la temperatura seleccionada (Tsel) durante la fotofase y la escotofase. Atractus crassicaudatus selecciona temperaturas corporales diferentes entre temporada seca (Tsel = 19.53-21.30 °C) y lluviosa (Tsel = 17.27-19.23 °C); termorregula activamente en seca y es termoconformista en lluvias. El uso de refugios rocosos en hábitat abiertos y semiabierto y el ajuste estacional de la temperatura seleccionada, sugiere tigmotermia y plasticidad en su fisiología térmica. Estas serpientes seleccionan un intervalo similar de temperaturas durante la fotofase y la escotofase, por lo que posiblemente termorregula comportamentalmente aún durante la fase de inactividad. En conclusión, esta serpiente nocturna responde a la variación circadiana y estacional en la calidad térmica de su microambiente mediante ajuste comportamental y fisiológico.

Abstract Thermoregulation in highland tropical environments imposes physiological challenges for reptiles. The interaction between individual thermal requirements with external thermal conditions in these environments remains mostly unknown. We examined the thermal strategy of the nocturnal snake Atractus crassicaudatus (Duméril, Bibron, and Duméril, 1854) in the highlands of the northern Andes. We depicted the relationship between the snake´s body temperatures on the field and under experimental conditions, with operative temperatures during 2 climatic seasons. Additionaly, we compared selected temperatures (Tsel) during the day (photophase) and night (scotophase). Individuals selected different body temperatures under dry (Tsel = 19.53-21.30 °C) and rainy (Tsel = 17.27-19.23 °C) seasons, they actively thermoregulate during the dry season, and they are thermoconformers during the rainy season. Their preference for rocky-shelters in open to semi-open habitats, and the seasonal adjustment of Tsel, suggest thigmothermy with plastic thermal physiology. Individuals select a similar range of temperatures during photophase and scotophase, then, thermoregulatory behavior might occur even during the “inactivity phase.” This nocturnal snake copes with the circadian and seasonal variation of environmental thermal quality through behavior and physiological adjustments.

Abstract Soil is a living, dynamic entity and at the same time vulnerable to degradation, if it is not managed with sustainable practices, causing low crop yields. The objective of this research was to determine the effects of plant cover associated with the cultivation of corn on soil properties: bulk density, gravimetric moisture, soil pH and electrical conductivity, organic matter, estimation of nitrogen supply when leaf biomass is incorporated, and finally corn yield. The study was conducted under a randomized complete block experimental design with five treatments: corn without cover crop (control), corn with clover cover crop; corn with vetch cover crop; corn with vetch + oats cover crop and corn with dead cover crop (mulch). The results showed that corn associated with clover, vetch and mulch (dead cover) increased grain yield (kg.ha1) of corn by 44%, 37% and 38%, respectively, compared to planting corn without any type of cover. Likewise, the use of clover, vetch and vetch cover crops associated with oats increased soil organic matter and soil input by 253, 163 and 149 kg ha-1 of nitrogen if the leaf biomass of the cover crops was incorporated into the soil. Therefore, the corn-clover association is the one that presents the best results to increase yields under sustainable soil management and agroecological principles.

Resumen El suelo es un ente vivo, dinámico y a la vez vulnerable a la degradación, siempre y cuando no se maneje de manera sostenible ocasionando bajos rendimientos de los cultivos. El objetivo de la presente investigación fue determinar los efectos de las coberturas vegetales asociado al cultivo de maíz amiláceo en las propiedades del suelo: densidad aparente, humedad gravimétrica, pH y conductividad eléctrica del suelo, materia orgánica, estimación del aporte de nitrógeno cuando se incorpora la biomasa foliar y finalmente el rendimiento de maíz. El estudio se realizó bajo un diseño experimental de bloques completos al azar con cinco tratamientos: maíz sin cobertura (testigo), maíz con cobertura de trébol; maíz con cobertura de vicia; maíz con cobertura de vicia + avena y maíz con cobertura muerta-mulch. Los resultados demostraron que, el maíz asociado con coberturas de trébol, vicia y mulch (cobertura muerta) aumentó en 44%, 37% y 38% respectivamente el rendimiento (kg.ha-1) de grano de maíz amiláceo, comparados a la siembra de maíz sin ningún tipo de cobertura. Asimismo, el uso de coberturas de trébol, vicia y avena + vicia incrementan la materia orgánica del suelo y aporta al suelo 253; 163 y 149 kg.ha-1 de nitrógeno siempre y cuando la biomasa foliar de las coberturas se incorpora al suelo. Por lo tanto, la asociación maíz - trébol es la que presenta mejores resultados para incrementar los rendimientos bajo un manejo sostenible del suelo y bajo los principios de la agroecología.

The present study compared the effects of a footwear designed to enhance energy return (thermoplastic polyurethane, TPU) vs minimalist shoes on running economy (RE) and endurance performance. In this counterbalanced and crossover design study, 11 recreational male runners performed two submaximal constant-speed running tests and two 3-km time-trials with the two shoe models. Oxygen uptake was measured during submaximal constant-speed running tests in order to determine the RE at 12 km/h and oxygen cost of running (CTO2) at individual average speed sustained during the 3-km running time-trials wearing either of the two shoes. Our results revealed that RE was improved (2.4%) with TPU shoes compared with minimalist shoes (P=0.01). However, there was no significant difference for CTO2 (P=0.61) and running performance (P=0.52) comparing the TPU (710±60 s) and the minimalist (718±63 s) shoe models. These novel findings demonstrate that shoes with enhanced mechanical energy return (i.e. TPU) produced a lower energy cost of running at low (i.e., 12 km/h) but not at high speeds (i.e., average speed sustained during the 3-km running time-trial, ∼15 km/h), ultimately resulting in similar running performance compared to the minimalist shoe.

Resumo Este estudo tem como objetivo avaliar a utilização de nanopartículas à base de silício (NS) e funcionalizadas (NF) como tratamento preventivo de superfície (ST) emergente em corpos de prova de concreto armado. As amostras foram fabricadas com uma relação água/cimento (a/c) de 0,65 e submetidas a um período de envelhecimento prévio por exposição ao CO2. Posteriormente, duas variantes diferentes do tratamento foram aplicadas por pulverização (utilizando uma dispersão de 0,1% de nanopartículas em água) e, em seguida, submetidas à carbonatação novamente. Os resultados de profundidade de carbonatação e ângulo de contato indicam que existe uma influência entre o grau de envelhecimento e a eficiência de cada tratamento.

Abstract This study aims to evaluate the use of silicon base (NS) and functionalized (NF) nanoparticles as emerging preventive surface treatment (ST) in reinforced concrete specimens. The specimens were fabricated with a water/cement (w/c) of 0.65 and subjected to a previous aging period through exposure to CO2. Subsequently, two different variants of the treatment were applied by spraying (using a 0.1% dispersion of nanoparticles in water) and then re-applied to carbonation. The carbonation depth and contact angle results indicate that there is an influence between the degree of aging and the efficiency of each treatment.

Resumen Este estudio, tiene como objetivo evaluar el uso de nanopartículas base silicio (NS) y funcionalizadas (NF) como tratamiento superficial (ST) preventivo emergente en especímenes de concreto reforzado. Los especímenes fueron fabricados con una relación agua/cemento (a/c) de 0.65 y sometidos a un periodo de envejecimiento previo mediante la exposición a CO2. Posteriormente, dos diferentes variantes del tratamiento fueron aplicadas mediante aspersión (usando una dispersión de 0.1% de nanopartículas en agua) y después fueron sometidas nuevamente a carbonatación. Los resultados de profundidad de carbonatación y ángulo de contacto indican que existe una influencia entre el grado de envejecimiento y la eficiencia de cada tratamiento.

RESUMO: A erva-cabecinha (Phalaris minor) é a segunda planta daninha mais problemática nos campos de trigo do Irã, pois tem desenvolvido resistência aos herbicidas inibidores da ACCase. Marcadores moleculares de intersequência repetitiva simples (ISSR) foram utilizados para avaliar a variação genética entre e dentro de populações resistentes e suscetíveis aos inibidores de ACCase de P. minor do Irã, a fim de elucidar a origem da resistência e sua dispersão. Dezesseis populações de P. minor de diferentes regiões do Irã foram analisadas usando sete primers ISSR. As relações genéticas obtidas a partir da análise UPGMA revelaram a presença de mais de um genótipo entre as populações resistentes aos herbicidas. Os resultados indicaram que a alta similaridade genética e proximidade física entre as populações resistentes de P. minor nas diferentes regiões foi devido principalmente à polinização cruzada, à dispersão mecânica de sementes e a fatores ecológicos locais. Assim, infere-se que ocorreu uma seleção independente, assim como a movimentação de sementes resistentes, explicando a ocorrência e dispersão da resistência nessas populações.

ABSTRACT: Littleseed canarygrass (Phalaris minor) is the second most serious and problematic grass weed in wheat fields in Iran, and has developed resistance to ACCase inhibiting herbicides. Inter-simple sequence repeat (ISSR) analysis was used to assess genetic variation between and within ACCase inhibitor-resistant and susceptible P. minor populations in Iran and to determine the origin of resistance and its dispersal. Sixteen P. minor populations from different regions in Iran were analysed using seven primers. Genetic relationships generated using UPGMA analysis indicated the presence of more than one genotype among the herbicide resistant populations. The results indicated that the high genetic similarity and physical proximity among the resistant P. minor populations in the different regions is mainly due to cross pollination, mechanical seed dispersion and local ecological factors. These findings suggested that independent selection as well as movement of resistant seeds had occurred, which could explain the presence and dispersion of ACCase inhibitor-resistance in these populations.

RESUMO: A deriva de herbicida, por falhas de aplicação, pode causar intoxicação em plantas de eucalipto, comprometendo o crescimento destas. Entretanto, a adição de produtos protetores como Fertiactyl Pós® à calda tem se mostrado eficiente na redução da intoxicação de plantas de eucalipto expostas à deriva de herbicidas. Em face do exposto, objetivou-se neste trabalho avaliar o efeito protetor do Fertiactyl Pós® sobre a redução de danos causados pela deriva dos herbicidas glyphosate, 2,4-D e a mistura glyphosate + 2,4-D em plantas de eucalipto. O experimento foi conduzido em esquema fatorial 3 x 2 + 1, correspondendo a três herbicidas: glyphosate (1.440 g ha-1), 2,4-D (680 g ha-1) e mistura em tanque de glyphosate + 2,4-D (1.440 g ha-1 + 680 g ha-1); duas doses de Fertiactyl Pós® (0 e 3,0 L ha-1); e uma testemunha sem aplicação. Antes da aplicação, a parte superior da copa do eucalipto foi protegida com sacos de polietileno, de modo a permitir que a calda atingisse apenas o terço inferior do dossel. A adição do Fertiactyl Pós® à calda com os herbicidas glyphosate e 2,4-D reduziu a intoxicação das plantas de eucalipto em 21,9% e 15,2%, respectivamente, aos 40 dias após a aplicação (DAA), em relação à aplicação dos respectivos herbicidas sem adição de Fertiactyl Pós®. A deriva da mistura glyphosate + 2,4-D potencializou a intoxicação das plantas do eucalipto em relação à aplicação isolada dos respectivos herbicidas e não houve resposta da adição do Fertiactyl Pós® na redução da intoxicação das plantas quando se aplicaram os herbicidas em mistura.

ABSTRACT: Herbicide drift, due to application failures, can cause intoxication in eucalyptus plants, compromising their growth. However, the addition of protective products such as Fertiactyl Pós® to the syrup has been shown to be efficient in reducing intoxication of eucalyptus plants exposed to herbicide drift. Given this, the objective of the present study was to evaluate the protective effect of Fertiactyl Pós® on the reduction of damage caused by the herbicides glyphosate, 2,4-D and the glyphosate + 2.4-D mixture in eucalyptus plants. The experiment was conducted in a 3 x 2 + 1 factorial scheme, corresponding to three herbicides: glyphosate (1,440 g ha-1), 2,4-D (680 g ha-1), glyphosate + 2.4- D (1,440 g ha-1 + 680 g ha-1); two doses of Fertiactyl Pós® (0 and 3.0 L ha-1) and one control without application. Prior to application, the top of the eucalyptus was covered with polyethylene bags to ensure the syrup only reached the lower third of the canopy. The addition of Fertiactyl Pós® to the syrup with glyphosate and 2.4 D herbicides reduced the intoxication of eucalyptus plants by 21.9 and 15.2%, respectively, at 40 days after application (DAA) when compared with the application of the respective herbicides without the addition of Fertiactyl Pós®. The glyphosate + 2.4-D mixture drift intensified the intoxication of the eucalyptus plants in comparison with the application of the respective herbicides in isolation. Besides, the addition of Fertiactyl Pós® to the glyphosate + 2,4-D mixture did not prevent plant intoxication.

ABSTRACT The present work was carried out at “Raúl Cepero Bonilla” Meat Company in Camagüey, Cuba, with the objective of evaluating its refrigeration system. Values for the parameters thermodynamic efficiency and COP of 3.849 and 59.86% were obtained for the compressor, respectively, which can be considered acceptable. The daily consumption of frigorific energy was of 4 332 kW, which is reduced by 61.18% with both improvement proposals, thus implying $ 27 114.32 of annual economic savings. The investment cost of installing Armaflex insulation at refrigeration pipes ascended to $ 103 234.24, while the investment cost of installing Polyurethane insulation at refrigeration chambers had a value of $ 506 536.38. The insulation investment in refrigeration pipes is recovered in 4.7 years. Excel spreadsheets were used to carry out calculations.

RESUMEN El presente trabajo se desarrolló en la empresa cárnica “Raúl Cepero Bonilla”, en Camagüey, Cuba con el objetivo evaluar el sistema de refrigeración. Se obtuvieron valores de coeficiente de rendimiento y de eficiencia termodinámica para el compresor de 3,849 y 59,86%, respectivamente, los cuales pueden considerarse aceptables. El consumo diario de energía frigorífica fue de 4 332 kW, el cual se reduce en un 61,18 %, con ambas propuestas de mejora, lo que implica un ahorro económico anual de $ 27 114,32. El costo de inversión de la instalación del aislante Armaflex en las tuberías de refrigeración ascendió a $ 103 234,24, mientras que el costo de inversión de la instalación del aislante Poliuretano en las cámaras frigoríficas tuvo un valor de $ 506 536,38. La inversión del aislante en las redes de tuberías de refrigeración se recupera en 4,76 años. Se emplearon hojas de cálculo Excel para la realización de los cálculos.

The objective of this study was to verify the agreement between pre-programmed and executed pacing during race walking and whether level of the athletes experience and performance influenced this relationship. Twenty-nine national and international race walkers participated in this study (14 males, 24.0±7.1 years old, and 15 females, 23.3±7.3 years old). Pre-programmed pacing for 10- and 20-km official walking races was self-selected via demonstrative pacing charts prior to races, while executed pacing was analyzed by a specialist investigator via an individual plot of current velocity versus distance. There was no agreement between pre-programmed and executed pacing (P=0.674). There was no association between the ability to match the pre-programmed pace with the executed pace and race walking experience or level of performance. Low- and high-performance athletes pre-programmed a similar pacing profile (P=0.635); however, high-performance athletes generally executed an even pacing strategy, while low-performance athletes generally adopted a positive pacing strategy (P=0.013). Race walkers did not faithfully match their pre-programmed with their executed pacing, and this seemed to be independent of previous experience and level of performance. High-performance athletes, however, tended to execute an even pacing strategy, even though this had not been pre-programmed.

Resumo O impacto de surfactantes na extrusão semiúmida de massas argilosas está diretamente relacionado ao desempenho associado à vazão mássica e respectivo consumo energético. Neste trabalho foi elaborada uma formulação baseada em uma massa empregada na fabricação de blocos estruturais aditivada com surfactante obtido de fonte renovável (tanino). O objetivo foi avaliar os impactos da adição do tanino na trabalhabilidade da massa, na redução do consumo de energia, na dureza do extrudado e nas propriedades dos corpos secos e sinterizados, i.e., resistência à flexão, retração linear e absorção de água. Na formulação com 1,0% em massa de tanino os resultados indicaram diminuição de ~37% da dureza da massa úmida, aumento da resistência mecânica após secagem (~29%) e queima (~15%) e redução de ~75% no consumo energético específico. O efeito global da adição sugere que o tanino pode ser utilizado, salvaguardando-se os critérios econômicos, sem comprometer a manutenção do desempenho dos blocos de cerâmica vermelha.

Abstract The impact of surfactants on the semi-solid extrusion of clay masses is directly related to the performance associated with the mass flow and energy consumption. In this work, a formulation based on a ceramic mass used in the manufacture of structural blocks was formulated with the addition of surfactant obtained from a renewable source (tannin). The objective was to evaluate the impacts of tannin addition on the workability of the mass, reduction of energy consumption, the hardness of the extrudate, and properties of the dry and sintered bodies (e.g. flexural strength, linear retraction and water absorption). For the ceramic mass formulation with 1.0 wt% tannin, the results indicated a decrease of ~37% in wet mass hardness, increase in mechanical strength after drying (~29%) and firing (~15%), and ~75% reduction in specific energy consumption. The overall positive effects of surface modifier addition to the ceramic mass suggest that tannin can be used, safeguarding the economic criteria, without compromising the performance of the red ceramic blocks.

Resumen Este artículo tiene como objetivo estudiar la previsión de la demanda intermitente de un tipo específico de pieza de reposición en una industria brasilera de sistemas de refrigeración que comercializa sus productos en el mercado latinoamericano. La demanda es caracterizada en términos de intermitencia y variabilidad. Los resultados son calculados usando métodos clásicos de previsión intermitente fuera de la muestra: Croston, Aproximación Syntetos-Boylan (SBA), Corrección Shale-Boylan-Johnston (SBJ), Algoritmo de Previsión de Agregación Múltiple (MAPA) y modelos basados en Redes Neuronales Artificiales (RNA). El Error Cuadrático Medio (RMSE) y Desvío Medio Absoluto (MAE) son utilizados para efectos de comparación y selección del modelo de previsión. El análisis comparativo de los resultados muestra que las previsiones basadas en modelos RNA simple de tres capas y entrenadas con el algoritmo Resilient Backpropagation presentan mejor desempeño. Los cálculos fueron realizados con el software R, RStudio, bibliotecas “forecast”, “tsintermittent” y “neuralnet”.

Abstract This article aims to study the intermittent demand forecasting for a specific type of spare part of a Brazilian refrigeration industry that commercialize its products in the Latin American market. Demand characterization is performed in terms of their intermittency and variability. Results are obtained with classical intermittent forecasting methods outside the sample: Croston, Syntetos-Boylan Approximation (SBA), Shale-Boylan-Johnston Correction (SBJ), Multiple Aggregation Prediction Algorithm (MAPA) and with Artificial Neural Networks (ANN) based models. Root Mean Square Error (RMSE) and Mean Absolute Error (MAE) are used for comparison and selection of forecast model. The comparative analysis results shows that the predictions based on a simple three-layer ANN model trained with the Resilient Backpropagation algorithm present better performance. The calculations were performed using R software with RStudio, "forecast", "tsintermittent" and "neuralnet" libraries.

Abstract: To determine the effect of oxytocin addition to semen on the performance of sows served, during summer-autumn, 223 multi parturient hybrid sows were utilized, assigned to one of two treatments in a completely randomized design. Treatments were: 1) Control (n = 111), sows inseminated with a reduced semen dosage (1.5 x 109 viable sperms cells in 40 mL of diluent), and 2) Test group (n = 112) Control plus the addition of 4 IU oxytocin to semen before service. Sows were inseminated from June to October 2012, using the technique of post cervical artificial insemination. The total number born piglet (TBP) and total number alive born (TAB) were registered at calving, those who were compared by ANOVA (P < 0.05). The farrowing rate was compared by X2 analyses, using 2 x 2 contingency tables. The addition of oxytocin to semen doses did not change (P > 0.05) litter size (11.03 vs. 10.78 TBP; 9.83 vs. 9.62 TAB). The 4 UI oxytocin addition to semen before service improved (P = 0.03) by 9.07 % the farrowing rate (84.68 vs. 93.75%). It is concluded that the addition of 4 IU of oxytocin to the reduced seminal doses, improves farrowing rate in sows inseminated during the warm season.

Resumen: Para determinar el efecto de la adición de oxitocina al semen en el desempeño reproductivo de las cerdas servidas durante la época de verano-otoño, se utilizaron 223 cerdas multíparas híbridas, asignadas a uno de dos tratamientos en un diseño experimental completamente al azar. Los tratamientos fueron:1) Testigo (n = 111), cerdas inseminadas con dosis seminales reducidas (1.5 x 109 espermatozoides en 40 mL de diluyente), y 2) Grupo de prueba (n = 112), testigo más la adición de 4 UI de oxitocina antes del servicio. Las cerdas fueron inseminadas entre junio y octubre de 2012, usando la técnica de inseminación post-cervical. El número de lechones nacidos totales (LNT) y nacidos vivos (LNV) fueron registrados al parto, a los que se le aplicó un ANDEVA (P < 0.05). La tasa de parto fue comparada por análisis de X2 , utilizando tablas de contingencia 2 x 2. La adición de oxitocina al semen no modificó (P > 0.05) el tamaño de camada (11.03 vs. 10.78 LNT; 9.83 vs. 9.62 LNV). La adición de 4 UI de oxitocina al semen antes de la inseminación mejoró (P = 0.03) en 9.07 % la tasa de parto (84.68 vs. 93.75%). Se concluye que la adición de 4 UI de oxitocina a dosis seminales reducidas mejora la tasa de parto en hembras inseminadas durante la época cálida.

Abstract Polycystic kidney disease associated with congenital hepatic fibrosis is an inherited disease; it is within the spectrum of diseases hepatorenal fibrocystic. Its estimated frequency is 1 in 20,000 live births for the variety of autosomal recessive polycystic kidney disease and rarer for autosomal dominant variety. One case report is presented about a patient whose illness began with a difficult control hypertensive crisis arises due to polycystic kidney disease and congenital hepatic fibrosis, a rare clinical presentation. Include the importance of controlling blood pressure to prevent complications due to high blood pressure as cardiac hypertrophy, heart failure and chronic retinopathy.

Resumen La enfermedad poliquística renal asociada a la fibrosis hepática congénita es una enfermedad hereditaria; se encuentra dentro del espectro de las enfermedades fibroquísticas hepatorrenales. Su frecuencia estimada es de 1 en 20.000 nacidos vivos para la variedad de enfermedad poliquística renal autosómica recesiva y más rara para la variedad autosómica dominante. Se presenta un reporte de caso de un paciente cuyo padecimiento se inició con crisis hipertensiva de difícil control, debido a enfermedad poliquística renal y fibrosis hepática congénita, presentación clínica poco frecuente; cabe mencionar sobre la importancia del control de la tensión arterial para prevenir complicaciones causadas por la hipertensión arterial: hipertrofia cardiaca, falla cardiaca y retinopatía crónica.