1,417 research outputs found
Southern Corn Rootworm (Coleoptera: Chrysomelidae) Adult Emergence and Population Growth Assessment After Selection With Vacuolar ATPase-A double-stranded RNA Over Multiple Generations
The southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae), was exposed over multiple generations to vacuolar (v)ATPase-A double-stranded (ds)RNA, first as adults and later, as neonate larvae. During adult selection, high mortality and lower fecundity were observed in the RNAi-selected cages after beetles were exposed to sublethal dsRNA concentrations that varied between LC40 and LC75. During larval selection, a delay in adult emergence and effects on population growth parameters were observed after neonates were exposed to sublethal dsRNA concentrations that varied between LC50 and LC70. Some of the parameters measured for adult emergence such as time to reach maximum linear adult emergence, time elapsed before attaining linear emergence, termination point of the linear emergence, and total days of linear emergence increase, were significantly different between RNAi-selected and control colonies for at least one generation. Significant differences were also observed in population growth parameters such as growth rate, net reproductive rate, doubling time, and generation time. After seven generations of selection, there was no indication that resistance evolved. The sublethal effects caused by exposures of southern corn rootworm to dsRNAs can affect important life history traits and fitness especially through delays in adult emergence and reduction in population growth. Although changes in susceptibility did not occur, the observation of sublethal effects suggests important responses to potential selection pressure. Assuming resistance involves a recessive trait, random mating between susceptible and resistant individuals is an important factor that allows sustainable use of transgenic plants, and delays in adult emergence observed in our studies could potentially compromise this assumption
Sublethal Effects of \u3ci\u3evATPase-A\u3c/i\u3e and \u3ci\u3eSnf7\u3c/i\u3e dsRNAs on Biology of Southern Corn Rootworm, \u3ci\u3eDiabrotica undecimpunctata howardi\u3c/i\u3e Barber
RNA interference is a powerful tool against corn rootworm. Adults and neonates of southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae), were exposed to the LC50 of vATPase-A and Snf7 double-stranded RNAs (dsRNAs), and the effects on female fecundity, egg viability, male fitness as measured by sperm viability and mating capacity, larval recovery along with dry weight, and instar determination 10 d after exposure to dsRNA, were determined. Significant reductions were observed for a number of parameters in dsRNA-exposed rootworms relative to control treatments. Female fecundity and larval recovery were significantly reduced after exposure to both dsRNAs. In addition, larval dry weight and recovery of 2nd and 3rd instars along with dry weight for 3rd instars were significantly reduced after neonate exposure to vATPase-A dsRNA. Neither dsRNA affected male capacity to mate or sperm viability after exposure to the respective LC50s. After 10 d of feeding on untreated corn roots, neonates that survived exposure for 2 d to the vATPase-A dsRNA LC50 exhibited lower dry weight than the control. There was significant gene knockdown in adult males and females after exposure for 5 d to LC50 of vATPase-A and Snf7 dsRNAs. The parameters are discussed in terms of fitness and possible outcomes after deployment of corn hybrids expressing dsRNAs
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Chimpanzee lip-smacks confirm primate continuity for speech-rhythm evolution
Speech is a human hallmark, but its evolutionary origins continue to defy scientific explanation. Recently, the open-close mouth rhythm of 2-7 Hz (cycles/second) characteristic of all spoken languages has been identified in the orofacial signals of several nonhuman primate genera, including orangutans, but evidence from any of the African apes remained missing. Evolutionary continuity for the emergence of speech is, thus, still inconclusive. To address this empirical gap, we investigated the rhythm of chimpanzee lip-smacks across four populations (two captive and two wild). We found that lip-smacks exhibit a speech-like rhythm at approximately 4 Hz, closing a gap in the evidence for the evolution of speech-rhythm within the primate order. We observed sizeable rhythmic variation within and between chimpanzee populations, with differences of over 2 Hz at each level. This variation did not result, however, in systematic group differences within our sample. To further explore the phylogenetic and evolutionary perspective on this variability, inter-individual and inter-population analyses will be necessary across primate species producing mouth signals at speech-like rhythm. Our findings support the hypothesis that speech recruited ancient primate rhythmic signals and suggest that multi-site studies may still reveal new windows of understanding about these signals' use and production along the evolutionary timeline of speech
Sensibilidade de plantas de eucalipto (Eucalyptus urograndis) à subdoses do herbicida dicamba
In view of the widespread increase in herbicide-resistant weeds, biotechnology companies have developed dicamba-tolerant soybean and cotton cultivars. This technology can, however, increase the risk of the product drifting to adjacent areas. This study was developed with the objective of the to evaluate the phytotoxicity and biometric variables of young eucalyptus plants exposed to subdoses of the herbicide dicamba. The experiment was carried out under field conditions in Rio Verde, state of Goiás, Brazil. The treatments were represented by the application of 0 (control), 7.5, 15, 30, 60, 120 or 240 g ae ha-1 of dicamba 45 days after the seedlings were planted in the field. In terms of phytotoxicity, the dicamba doses of 120 and 240 g ae ha-1 caused greater damage to the eucalyptus plants in all periods of evaluation. The predominant symptoms were epinasty, increased number of shoots and necrosis and senescence of young branches and leaves. The herbicide doses of 120 and 240 g ae ha-1 significantly compromised plant height and diameter, number of branches and dry mass of leaves and roots, interfering with the growth and development of the eucalyptus crop. The results indicate that the effect of subdoses of the herbicide dicamba can interfere with the proper development of young eucalyptus plants, which may cause losses in the initial planting phase and future losses for producers.Em decorrência do aumento generalizado de plantas daninhas com resistência a herbicidas, empresas de biotecnologia desenvolveram cultivares de soja e algodão tolerantes ao herbicida dicamba. Essa tecnologia pode, no entanto, aumentar o risco do produto ser deslocado para áreas adjacentes às aplicadas. Neste trabalho objetivou-se avaliar a fitotoxicidade e variáveis biométricas de plantas jovens de eucalipto tratadas com subdoses do herbicida dicamba. O experimento foi realizado em condições de campo em Rio Verde, Goiás, Brasil. Os tratamentos foram representados pela aplicação de 0 (testemunha), 7,5, 15, 30, 60, 120 ou 240 g ea ha-1 de dicamba aos 45 dias após o plantio das mudas no campo. Em termos de fitotoxicidade, as doses de dicamba de 120 e 240 g ea ha-1 causaram maiores danos às plantas de eucalipto em todos os períodos de avaliação. Os sintomas predominantes foram epinastia, aumento do número de brotações e necrose e senescência de ramos e folhas jovens. As doses de herbicidas de 120 e 240 g ea ha-1 comprometeram significativamente a altura e diâmetro das plantas, número de ramos e massa seca de folhas, caules e raízes, interferindo no crescimento e desenvolvimento da cultura do eucalipto. Os resultados indicam que o efeito de subdoses do herbicida dicamba pode interferir no bom desenvolvimento de plantas jovens de eucalipto, podendo causar prejuízos na fase inicial de plantio e prejuízos futuros para os produtores
MODELAGEM E ANÁLISE TEMPORAL DA DINÂMICA DO USO E OCUPAÇÃO DO SOLO NA BACIA DO RIO CUIÁ-PB
MODELING AND TEMPORAL ANALYSIS OF DYNAMICS OF SOIL USE AND OCCUPATION IN THE CUIÁ-PB RIVER BASINMODELACIÓN Y ANÁLISIS TEMPORAL DE LA DINÁMICA DEL USO Y OCUPACIÓN DEL SUELO EN LA CUENCA DEL RÍO CUIÁ-PBRESUMONas últimas duas décadas o crescimento da população acelerou o processo de ocupação humana nessas áreas ao longo dos rios, criando diversos problemas ambientais. Assim, este trabalho teve por objetivo analisar as mudanças no uso e ocupação do solo na bacia do rio Cuiá e estimar o uso e ocupação do solo para a bacia da Cuiá para o ano de 2030, utilizando algoritmo de Redes Neurais artificiais: Rede Neural Multi-Layer Perceptron. Dessa forma, foi realizado o processamento de imagens de satélites dos anos de 1998, 2001 e 2005, realizada a predição do uso do solo para o ano de 2001 baseado em Redes Neurais para a validação. Em seguida, o resultado da predição do uso do solo foi analisado pelo do índice Kappa e após obtenção do índice Kappa com um resultado de acordo com a classificação prevista por Landis & Koch (1977) foi realizada a predição do uso e ocupação do solo para 2030. Os resultados mostraram um aumento da classe Ocupadas entre os anos analisados. A modelagem dinâmica do uso do solo baseada em Rede Neural mostrou resultados satisfatórios para a bacia do rio Cuiá com acurácia de 98,64%, após 10.000 iterações e índice Kappa igual a 0,94, classificado como excelente. A previsão do uso do solo para 2030 apresentou aumento da área da classe Ocupada e uma diminuição da área com expansão.Palavras-chave: Uso do solo. Redes neurais. Geoprocessamento.ABSTRACTIn the last two decades the population growth accelerated the process of human occupation in these areas along the rivers, creating several environmental problems. Thus this study aimed to analyze the changes in land use and occupation in the Cuiá river basin and to estimate the land use and occupation for the Cuiá basin for the year 2030 using an artificial neural network algorithm: Multi-Layer Perceptron Neural Network. In this way, the satellite image processing of the years of 1998, 2001 and 2005 was carried out, with the prediction of the use of the ground for the year 2001 based on neural networks for the validation, followed by the prediction of the land use was analyzed through the Kappa index and after obtaining the Kappa with a result according to the classification predicted by Landis & Koch (1977) the use and occupation of the soil was predicted by 2030. The results showed an increase of the Occupied class among the analyzed years. The dynamic modeling of soil use based on Neural Network showed satisfactory results for the Cuiá River basin with accuracy of 98.64%, after 10,000 iterations and Kappa equal to 0.94, classified as excellent. Prediction of land use for 2030 showed an increase in the area of the occupied class and a decrease of the area with expansion.Keywords: Soil use. Neural network. Geoprocessing.RESUMENEn las últimas dos décadas el crecimiento de la población aceleró el proceso de ocupación humana en esas áreas a lo largo de los ríos, creando diversos problemas ambientales. Entonces este trabajo tuvo por objetivo analizar los cambios en el uso y ocupación del suelo en la cuenca del Río Cuiá y estimar el uso y ocupación del suelo para la cuenca de Cuiá para el año 2030 utilizando algoritmo de Redes Neurales Artificiales: Red Neural Multi-Layer Perceptron. De esta forma, se realizó el procesamiento de imágenes de satélites de los años 1998, 2001 y 2005, realizada la predicción del uso del suelo para el año 2001 basado en Redes Neurales para la validación, luego el resultado de la predicción del uso del suelo se analizó por el índice Kappa y tras la obtención del índice Kappa con un resultado de acuerdo con la clasificación prevista por Landis & Koch (1977) se realizó la predicción del uso y ocupación del suelo para 2030. Los resultados mostraron un aumento de la clase Ocupados entre los años analizados. El modelado dinámico del uso del suelo basado en Red Neural mostró resultados satisfactorios para la cuenca del Río Cuiá con exactitud del 98,64%, después de 10.000 iteraciones e índice Kappa igual a 0,94, clasificado como excelente. La previsión del uso del suelo para 2030 presentó aumento del área de la clase Ocupada y una disminución del área con expansión.Palabras clave: Uso del suelo. Red neurales; Geoprocesamiento
Evaluation of reference genes for real-time quantitative PCR analysis in southern corn rootworm, \u3ci\u3eDiabrotica undecimpunctata howardi\u3c/i\u3e (Barber)
Quantitative reverse transcription PCR (RT-qPCR) is one of the most efficient, reliable and widely used techniques to quantify gene expression. In this study, we evaluated the performance of six southern corn rootworm, Diabrotica undecimpunctata howardi (Barber), housekeeping genes (HKG), β-actin (Actin), β-tubulin (Tubulin), elongation factor 1 alpha (EF1α), glyceraldehyde-3 phosphate dehydrogenase (GAPDH), 40 S ribosomal protein S9 (RpS9) and ubiquitin-conjugating protein (Ubi), under different experimental conditions such as developmental stage, exposure of neonate and adults to dsRNA, exposure of adults to different temperatures, different 3rd instar larva tissues, and neonate starvation. The HKGs were analyzed with four algorithms, including geNorm, NormFinder, BestKeeper, and delta-CT. Although the six HKGs showed a relatively stable expression pattern among different treatments, some variability was observed. Among the six genes, EF1α exhibited the lowest Ct values for all treatments while Ubi exhibited the highest. Among life stages and across treatments, Ubi exhibited the least stable expression pattern. GAPDH, Actin, and EF1α were among the most stable HKGs in the majority of the treatments. This research provides HKG for accurate normalization of RTqPCR data in the southern corn rootworm. Furthermore, this information can contribute to future genomic and functional genomic research in Diabrotica species
Evaluation of reference genes for real-time quantitative PCR analysis in southern corn rootworm, \u3ci\u3eDiabrotica undecimpunctata howardi\u3c/i\u3e (Barber)
Quantitative reverse transcription PCR (RT-qPCR) is one of the most efficient, reliable and widely used techniques to quantify gene expression. In this study, we evaluated the performance of six southern corn rootworm, Diabrotica undecimpunctata howardi (Barber), housekeeping genes (HKG), β-actin (Actin), β-tubulin (Tubulin), elongation factor 1 alpha (EF1α), glyceraldehyde-3 phosphate dehydrogenase (GAPDH), 40 S ribosomal protein S9 (RpS9) and ubiquitin-conjugating protein (Ubi), under different experimental conditions such as developmental stage, exposure of neonate and adults to dsRNA, exposure of adults to different temperatures, different 3rd instar larva tissues, and neonate starvation. The HKGs were analyzed with four algorithms, including geNorm, NormFinder, BestKeeper, and delta-CT. Although the six HKGs showed a relatively stable expression pattern among different treatments, some variability was observed. Among the six genes, EF1α exhibited the lowest Ct values for all treatments while Ubi exhibited the highest. Among life stages and across treatments, Ubi exhibited the least stable expression pattern. GAPDH, Actin, and EF1α were among the most stable HKGs in the majority of the treatments. This research provides HKG for accurate normalization of RTqPCR data in the southern corn rootworm. Furthermore, this information can contribute to future genomic and functional genomic research in Diabrotica species
Evaluation of reference genes for real-time quantitative PCR analysis in southern corn rootworm, \u3ci\u3eDiabrotica undecimpunctata howardi\u3c/i\u3e (Barber)
Quantitative reverse transcription PCR (RT-qPCR) is one of the most efficient, reliable and widely used techniques to quantify gene expression. In this study, we evaluated the performance of six southern corn rootworm, Diabrotica undecimpunctata howardi (Barber), housekeeping genes (HKG), β-actin (Actin), β-tubulin (Tubulin), elongation factor 1 alpha (EF1α), glyceraldehyde-3 phosphate dehydrogenase (GAPDH), 40 S ribosomal protein S9 (RpS9) and ubiquitin-conjugating protein (Ubi), under different experimental conditions such as developmental stage, exposure of neonate and adults to dsRNA, exposure of adults to different temperatures, different 3rd instar larva tissues, and neonate starvation. The HKGs were analyzed with four algorithms, including geNorm, NormFinder, BestKeeper, and delta-CT. Although the six HKGs showed a relatively stable expression pattern among different treatments, some variability was observed. Among the six genes, EF1α exhibited the lowest Ct values for all treatments while Ubi exhibited the highest. Among life stages and across treatments, Ubi exhibited the least stable expression pattern. GAPDH, Actin, and EF1α were among the most stable HKGs in the majority of the treatments. This research provides HKG for accurate normalization of RTqPCR data in the southern corn rootworm. Furthermore, this information can contribute to future genomic and functional genomic research in Diabrotica species
QUALIDADE DE LEITES FERMENTADOS BRASILEIROS E ATIVIDADE ANTAGONISTA IN VITRO DE SUAS BACTÉRIAS ÁCIDO LÁTICAS
Avaliou-se a qualidade de cinco leites fermentados brasileiros, coletados em pontos de vendas de Viçosa (MG), assim como a atividade antagonista in vitro de suas bactérias ácido láticas para micro-organismos indicadores desejáveis e patogênicos. Todos os lotes avaliados estavam em conformidade com a legislação brasileira quanto ao teor de gordura e contagem de bolores e leveduras. Alguns lotes evidenciaram acidez titulável (20 %) e teor de proteína (52 %) abaixo do limite permitido pela legislação nacional. Quanto à concentração de bactérias ácido láticas, 32 e 96 % dos lotes não apresentaram contagens mínimas em conformidade com os limites estabelecidos pelo MAPA e pela ANVISA, respectivamente, o que implica na necessidade de fiscalização do produto. As bactérias ácido láticas demonstraram maior antagonismo para Salmonella enterica, Escherichia coli e Staphylococcus aureus que para a bactéria ácido lática utilizada como indicadora. Alguns lotes de leites fermentados não estavam em conformidade com a legislação, ainda que as bactérias ácido láticas avaliadas tenham importância para a preservação de produtos e controle de patógenos
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