Has yield plasticity already been exploited by soybean breeding programmes in Argentina?

This study focuses on the impact of genetic improvement of seed yield plasticity in soybean (Glycine max L.) in high-yielding environments (between 4000 kg ha-1 and 7000 kg ha-1) of Central Argentina. The association between seed yield and its plasticity was analysed with (i) a historical collection of 148 genotypes released to the market between 1980 and 2013 and (ii) 165 currently available commercial genotypes. The impact on seed yield of soybean breeding programmes in Argentina reveals higher genetic progress of the lowest (1.7% year-1) rather than the highest yielding genotypes (0.9% year-1). At the same time, seed yield plasticity has been exploited indirectly. Increased seed yield plasticity over time contributed to a reduction in genotypic seed yield variability (P<0.0001). Seed yield plasticity was related to seed yield in high-yielding environments (>5500 kg ha-1). Plastic genotypes showed a positive correlation with the length of the seed-filling period (r=0.5), suggesting that a longer seed-filling period could be required to maximize seed yield plasticity under high-yielding environments. To increase productivity, clarifying the value of plasticity will aid genotype selection for target environments, as well as the development of high-yielding cultivars specifically adapted to high-yielding conditions.

Properties of the density of shear transformations in driven amorphous solids.

The strain load Δγthat triggers consecutive avalanches is a key observable in the slow deformation of amorphous solids. Its temporally averaged value ⟨Δγ⟩ displays a non-trivial system-size dependence that constitutes one of the distinguishing features of the yielding transition. Details of this dependence are not yet fully understood. We address this problem by means of theoretical analysis and simulations of elastoplastic models for amorphous solids. An accurate determination of the size dependence of ⟨Δγ⟩ leads to a precise evaluation of the steady-state distribution of local distances to instabilityx. We find that the usually assumed formP(x) ∼xθ(withθbeing the so-called pseudo-gap exponent) is not accurate at lowxand that in generalP(x) tends to a system-size-dependentfinitelimit asx→ 0. We work out the consequences of this finite-size dependence standing on exact results for random-walks and disclosing an alternative interpretation of the mechanical noise felt by a reference site. We test our predictions in two- and three-dimensional elastoplastic models, showing the crucial influence of the saturation ofP(x) at smallxon the size dependence of ⟨Δγ⟩ and related scalings.

The selective obtaining of amyrins from Amazonian Protium oleoresins / La obtención selectiva de amirinas a partir de oleorresinas de Protium amazónicas

SUMMARY The oleoresin produced by species of genus Protium sp. is rich in alpha and betaamyrins, two triterpenes with many pharmacogical activities. Considering the need to make the improved obtainment of these products feasible, this study sought to optimize techniques for the extraction and isolation of amyrins from resin. Two methods of extraction (maceration and sonication) with different solvents were compared to direct isolation from crude resin. The isolation of triterpenes was performed by chromatographic columns and the yields of extracts and fractions were analyzed by analysis of variance. The best extraction solvent for amyrins was hexane for both maceration and sonication methods (38.16±2.06% and 37.67±8.21%, respectively). There was no statistical difference between these methods and the direct method (32.05±2.40%). Additionally, the direct method is cheaper and more environmentally friendly. Thus, this study showed that it is possible to obtain a large quantity of amyrins by means of cheap, fast and ecological methods.

RESUMEN La oleorresina producida por especies del género Protium sp. es rica en amirinas alfa y beta, dos triterpenos con muchas actividades farmacológicas. Esta investigación buscó optimizar las técnicas de extracción y aislamiento de amirinas de la resina para hacer factible la obtención mejorada de esos productos. Se compararon dos métodos de extracción (maceración y sonicación) con diferentes solventes con aislamiento directo de la resina cruda. El aislamento de los triterpenos se realizó mediante columnas cromatográficas y los rendimientos de extractos y fracciones fueron hechos mediante análisis de varianza. El mejor solvente para la extracción de amirinas fue el hexano para ambos métodos de maceración y sonicación (38,16±2,06% y 37,67±8,21%, respectivamente). No hubo diferencia estadística entre estos métodos y el método directo (32,05±2,40%). Además, el método directo es más barato y ecológico. De este modo, esta investigación demostró que es posible obtener una gran cantidad de amirinas a través de métodos rápidos, baratos y ecológicos.

Parámetros Genéticos y no Genéticos para Caracteres de Crecimiento en un Rebaño Brahman Registrado / Genetic and Non-genetic Parameters for Growth Traits in a Registered Brahman Herd

Se realizó un estudio genético cuantitativo para determinar el peso al nacer (PN), peso al destete corregido a 205 d (P205) y peso a los 18 meses corregido a 548 d (P548) en un rebaño Brahman ubicado en el estado Cojedes, Venezuela, bajo un programa genético y ambiental supervisado. Se analizaron los registros de 5137 animales, nacidos durante los años 1996 a 2007. Se estimaron los componentes de (co)variancias, parámetros genéticos y no genéticos, a través de tres modelos animal univariados usando el paquete de programas MTDFREML. Todos los modelos incluyeron los efectos aleatorios: genético aditivo directo, genético aditivo materno y ambiental permanente de la madre y como efecto fijo: grupo de contemporáneos. Los valores de índices de herencia directos fueron 0,45, 0,20 y 0,34, y los índices de herencia maternos 0,02, 0,13 y 0,04 para PN, P205 y P548, respectivamente. Las correlaciones genéticas aditivas directas - maternas fueron positivas. Los estimados para las tendencias fenotípicas anuales fueron de 0,285 kg para PN, 2,045 kg para P205 y 0,503 kg para P548. Las tendencias genéticas anuales aditivas directas fueron 0,075 kg, 0,523 kg y 1,072 kg y las genéticas maternas fueron 0,0002 kg, 0,230 kg y 0,096 kg para PN, P205 y P548, respectivamente. Los resultados indican que existe suficiente variabilidad genética para crecimiento en la población evaluada, lo que favorece el programa de selección por crecimiento.

A quantitative genetic study for birth weight (BW), weaning weight corrected at 205 days (WW205), and weight at 18 months corrected at 548 days (W548), was conducted in a Brahman herd located in the State of Cojedes, Venezuela, under a supervised genetic and environmental program. The records of 5137 animals born from 1996-2007 were analyzed. Components of covariance, genetic and non-genetic parameters were estimated through three univariate animal models, using the MTDFREML set of programs. All models included random effects, such as direct genetic additive, maternal genetic additive, and permanent environmental of the dam; and as a fixed effect, the contemporary group. The direct heritability indexes were 0.45, 0.20, and 0.34; and the maternal heritability indexes were 0.02, 0.13 and 0.04 for BW, WW205 and W548, respectively. All genetic additive direct-maternal correlations were positive. The estimates for the annual phenotypic trends were 0.285 for BW, 2.045 for WW205, and 0.503 for W548; respectively. The direct additive annual trends were 0.075 kg, 0.523 kg, and 1.072 kg for BW, WW205, and W548, respectively. The results of the investigation indicate the existence of enough genetic variability for growth in the evaluated population, which favors the selection program for growth.

Glucose as the sole metabolic fuel: overcoming a misconception using conceptual change to teach the energy-yielding metabolism to Brazilian high school students.

A misconception regarding the human metabolism has been shown to be widespread among high school students. The students consider glucose as the sole metabolic fuel, disregarding that lipids and amino acids can be oxidized for ATP production by human cells. This misconception seems to be a consequence of formal teaching in grade and high schools. The present study reports the evaluation of a teaching strategy based on the use of a dialogic teaching methodology within a conceptual change approach to remediate that misconception. Students were stimulated to formulate hypotheses, outline experiments, and to discuss their outcomes. The results showed that students were able to reformulate their original concepts immediately after teaching. The majority of the students showed adequate learning of the topic eight months after the application of the teaching strategy, although some level of misconception recurrence was observed. The educational consequences of the teaching unit are discussed in the context of the possible reasons for its success as well as the need for similar initiatives at grade school to avoid the establishment of the misconception.

Relationship among blood indicators of lipomobilization and hepatic function during early lactation in high-yielding dairy cows.

Blood indicators are used as a tool to diagnose metabolic disorders. The present work was conducted to study the relationships among blood indicators of lipomobilization and hepatic function in high-yielding dairy cows. Two groups of Holstein cows were studied: 27 early lactation cows and 14 mid lactation cows from four different herds with similar husbandry characteristics in Galicia, Spain. Blood samples were obtained to measure beta-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA), triglycerides (TG), and the activity of aspartate transaminase (AST) and gamma-glutamyl transferase. Cows in early lactation had higher levels of BHB and NEFA than mid lactation cows. High lipomobilization (NEFA > 400 µmol/L) was detected in 67% and 7% of early lactation and mid lactation cows, respectively, while subclinical ketosis (BHB > 1.2 mmol/L) was detected in 41% and 28% of the early lactation and lactation cows, respectively. TG concentrations were low in all cows suffering subclinical ketosis and in 61% of the cows with high lipomobilization. During early lactation, 30% of cows suffered hepatic lipidosis as detected by levels of AST. Compromised hepatic function was observed in early lactation cows as shown by lower concentrations of glucose, total protein, and urea.

Redução do teor de gordura em hambúrgueres de carne bovina / Reducing the fat content in beef hamburgers

O presente trabalho teve por objetivo analisar diferentes formulações de hambúrgueres de carne bovina com utilização de substitutos de gordura. Foram avaliadas 25 formulações de hambúrgueres onde variou-se o teor de gordura (0, 10 e 15%), farinha de aveia (0 e 5%), proteína de soja (0 e 12%) e azeite de oliva extra virgem (0 e 10%). Foram avaliados o rendimento no cozimento e porcentagem de encolhimento, a retenção de água e atributos sensoriais como sabor, textura e cor. Os maiores rendimentos, menores encolhimentos e maior capacidade de retenção de água foram encontrados nos hambúrgueres com adição de farinha de aveia e/ou proteína texturizada de soja. Na análise sensorial as amostras que apresentam uma maior porcentagem de carne em sua composição tiveram as maiores notas nos atributos cor e sabor. Em relação à textura os painelistas preferiram amostras que continham uma maior número de combinações de ingredientes.(AU)

This work had the aim to analyze different ingredients, in distinct concentrations, as substitutes of fat inbeef hamburger. There were evaluated 25 formulations of hamburger to the clean meat base, added with fat (0,10 and 15%), oatmeal (0 e 5%), textured soy protein ( 0 e 12%) and extra virgin olive oil (O e 10%) as substitutes of fat. There were evaluated the yielding in cooking, percentage of shrinking, water retention, besides the sensorial attributes as taste, texture and color. The hamburgers that contain only beef and oatmeal and/or processed soy protein and/or olive oil in their formulations present a reduced fat tenor. The greatest yielding, smaller shrinks and larger capacity of water retention can be found in the hamburgers with oatmeal and/or textured soy protein added. In the sensorial analyzes the samples that present a great percentage of meat in their composition had the greatest grades in the color and flavor attributes. In relation to the texture the panelists preferred the samples that contained a larger number of combinations of ingredients. (AU)

Efeito do período de jejum pré-abate sobre o rendimento de carcaça de frango de corte / Effect of pre-laughter fasting periods on the carcass yielding of commercial broilers

Avaliaram-se os efeitos de cinco períodos (quatro, oito, 12, 14 e 16 horas) de jejum pré-abate sobre a perda de peso e rendimento de carcaça e cortes de frangos de corte. Foram utilizados 240 frangos (120 machos e 120 fêmeas), linhagem Cobb, criados até 44 dias de idade. No 44º dia, as aves foram separadas de acordo com o período de jejum (tratamentos) e o sexo, cada tratamento com 24 repetições. Nos tratamentos de quatro, oito, 12 e 16 horas, o jejum foi alimentar e no tratamento de 14 horas, o jejum foi alimentar e hídrico. O teste utilizado para as análises das médias foi o SNK (Student-Newman-Keuls). Foram analisadas as seguintes variáveis: perda de peso vivo após o jejum, taxa de absorção de água pela carcaça, rendimentos da carcaça inteira e dos cortes comerciais coxa e sobrecoxa, peito, dorso, asa, pés e cabeça e pescoço, rendimentos da moela e fígado e peso dos intestinos. Os períodos de jejum de oito, 12, 14, e 16 horas apresentaram maior rendimento de carcaça, sendo superiores ao período de quatro horas de jejum (P<0,05). O tratamento de quatro horas de jejum apresentou maior rendimento de fígado e peso de intestino em relação aos demais tratamentos (P<0,05). O período de jejum não influenciou a taxa de absorção de água nem o peso de moela (P>0,05). As fêmeas absorveram mais água do que os machos, e apresentaram rendimentos de carcaça e cortes comerciais superiores aos dos machos (P<0,05).(AU)

This experiment was designed in order to evaluate the effect of five intervals of pre-slaughter fasting (four, eight, 12, 14 and 16 hours) on weight loss, carcass yielding and poultry cuts yielding of broiler chickens. A total of 120 males and 120 females broiler chickens of Cobb lineage were raised during 44 days. On the 44th day, chickens were grouped according to their fasting period (treatments) and gender. Each treatment was composed of 24 repetitions. Animals of the of four, eight, 12 and 16 hours treatments were not fed ration while animals of the 14 hours fasting treatment were not fed ration or water. The statistical test used for mean comparison was SNK (Student-Newman-Keuls). The following variables were analyzed: loss of live weight, rate of water absorbed by carcass; whole carcass and commercial cuts (legs and forelegs, chest, dorsum, wings, feet and head and neck) yielding; gizzard and liver yielding as well as intestinal weight. The fasting periods of eight 12, 14 and 16 hours showed greater carcass yielding (P<0.05) being higher than those from the four hours fasting period. The four hours fasting group showed the highest yielding of liver and intestinal weight in relation to the other groups (P<0.05). The fasting period did not influence the rate of water absorption or the gizzard weight (P>0.05). Females retained more water than males and showed higher carcass and commercial cuts yielding than males (P<0.05).(AU)

Adaptabilidade e estabilidade de cultivares de alfafa em relação a diferentes épocas de corte

An experiment was carried out at the Animal Science Experimental Station of Sertãozinho, São Paulo, Brazil. The experimental design was a randomized block design, with three replications. Plots were constituted of 5 rows, with 5m long, separated by 0.2m. Thirty-five alfalfa cultivars were evaluated for dry matter yield in 29 yielding dates, from October, 1996 to March, 1999. Adaptability and stability study was stimated with Eberhart & Russell and Lin & Binns methods. Significant cultivar x yielding dates interaction was verified, indicating that the relative behavior of the cultivars was not the same in the different yielding dates. Among the 35 evaluated cultivars, 14 presented wide adaptability ( FONT FACE=Symbol>b1i /FONT> = 1) and good predicability ( FONT FACE=Symbol>s²di /FONT> = 0), according to the Eberhart & Russell method. Among 10 cultivars that had high adaptability and predicability (smallest values of Pi), estimated by Lin & Binns method, seven also had high adaptability and good predicability, estimated by Eberhart & Russell method. The cultivars SW 8210, Victoria SP, MH 15, 5888, Araucana, BR 1 and BR 3 had the high test adaptability and predicability, estimations obtained in both employed methods.

O experimento foi conduzido na Estação Experimental de Zootecnia de Sertãozinho-SP. O delineamento experimental foi o de blocos casualizados com 3 repetições, sendo a parcela constituída de 5 fileiras de 5m de comprimento, espaçados 0,2 m. Avaliou-se a produção de matéria seca de 35 cultivares de alfafa em 29 cortes realizados no período de outubro/1996 a março/1999. O estudo da adaptabilidade e estabilidade das cultivares ao longo dos 29 cortes, foi realizado por meio das metodologias de Eberhart e Russell e Lin e Binns. Verificou-se a existência de interação cultivares x cortes, demonstrando que o comportamento relativo das cultivares não era o mesmo nos diferentes cortes. Das 35 cultivares avaliadas, 14 apresentaram adaptabilidade geral ( FONT FACE=Symbol>b1i /FONT > ou = 1) e boa previsibilidade ( FONT FACE=Symbol>s²di /FONT> = 0), segundo a metodologia de Eberhart e Russell. Das 10 cultivares que apresentaram maior adaptabilidade e estabilidade (menores Pi), segundo a metodologia de Lin e Binns sete também apresentaram adaptabilidade geral e boa previsibilidade segundo a metodologia de Eberhart e Russell. As cultivares SW 8210, Victoria SP, MH 15, 5888, Araucana, BR 1 e BR 3 foram as que apresentaram maior adaptabilidade e estabilidade de comportamento, pelos dois métodos utilizados.

Adaptabilidade e estabilidade de cultivares de alfafa em relação a diferentes épocas de corte

An experiment was carried out at the Animal Science Experimental Station of Sertãozinho, São Paulo, Brazil. The experimental design was a randomized block design, with three replications. Plots were constituted of 5 rows, with 5m long, separated by 0.2m. Thirty-five alfalfa cultivars were evaluated for dry matter yield in 29 yielding dates, from October, 1996 to March, 1999. Adaptability and stability study was stimated with Eberhart & Russell and Lin & Binns methods. Significant cultivar x yielding dates interaction was verified, indicating that the relative behavior of the cultivars was not the same in the different yielding dates. Among the 35 evaluated cultivars, 14 presented wide adaptability ( FONT FACE=Symbol>b1i /FONT> = 1) and good predicability ( FONT FACE=Symbol>s²di /FONT> = 0), according to the Eberhart & Russell method. Among 10 cultivars that had high adaptability and predicability (smallest values of Pi), estimated by Lin & Binns method, seven also had high adaptability and good predicability, estimated by Eberhart & Russell method. The cultivars SW 8210, Victoria SP, MH 15, 5888, Araucana, BR 1 and BR 3 had the high test adaptability and predicability, estimations obtained in both employed methods.

O experimento foi conduzido na Estação Experimental de Zootecnia de Sertãozinho-SP. O delineamento experimental foi o de blocos casualizados com 3 repetições, sendo a parcela constituída de 5 fileiras de 5m de comprimento, espaçados 0,2 m. Avaliou-se a produção de matéria seca de 35 cultivares de alfafa em 29 cortes realizados no período de outubro/1996 a março/1999. O estudo da adaptabilidade e estabilidade das cultivares ao longo dos 29 cortes, foi realizado por meio das metodologias de Eberhart e Russell e Lin e Binns. Verificou-se a existência de interação cultivares x cortes, demonstrando que o comportamento relativo das cultivares não era o mesmo nos diferentes cortes. Das 35 cultivares avaliadas, 14 apresentaram adaptabilidade geral ( FONT FACE=Symbol>b1i /FONT > ou = 1) e boa previsibilidade ( FONT FACE=Symbol>s²di /FONT> = 0), segundo a metodologia de Eberhart e Russell. Das 10 cultivares que apresentaram maior adaptabilidade e estabilidade (menores Pi), segundo a metodologia de Lin e Binns sete também apresentaram adaptabilidade geral e boa previsibilidade segundo a metodologia de Eberhart e Russell. As cultivares SW 8210, Victoria SP, MH 15, 5888, Araucana, BR 1 e BR 3 foram as que apresentaram maior adaptabilidade e estabilidade de comportamento, pelos dois métodos utilizados.