Influence of fertilization on nitrate content in pastures and milk in the west of Santa Catarina over the year

The indiscriminate use without criteria of nitrogen fertilization can lead to an accumulation of nitrate in pastures, animal poisoning and potential increase in residual content of this compound in milk. The objective of this study was to determine the residual levels of nitrate throughout the year in pastures and milk from small farms in western Santa Catarina (SC) that use high levels of nitrogen fertilization. The experiment was carried out from April/2018 to March/2019 on 10 dairy farms in the municipality of Riqueza (SC). Two annual collections of water samples and monthly collections of pastures and milk were carried out, in addition to obtaining information on the property and management of pasture fertilization through a structured questionnaire. Nitrate was also evaluated in pastures using the diphenylamine test. Temperature and rainfall data were obtained daily by a weather station. The average amount of nitrogen fertilizer used in the properties was 654 ± 176 kg/ha/year. The average nitrate content in the drinking water of the animals was 1.5 ± 1.4 mg/L, in the pasture it was 270 ± 76 mg/kg DM, while in milk it was 2.0 ± 0.3 mg/L. There was seasonal variation with an increase in nitrate content in pastures and milk in autumn, a period of the experiment in which low rainfall was observed. It was concluded that despite being dairy properties with high use of nitrogen fertilization, safe milk is produced in terms of nitrate levels, even in times of the year with adverse climatic conditions. The diphenylamine test has a good ability to discriminate the nitrate content in pastures and can be indicated as a quick test to verify the presence of high levels of nitrate in the pasture.O uso indiscriminado da adubação nitrogenada pode levar ao acúmulo de nitrato nas pastagens, intoxicar animais e aumentar os níveis nocivos residuais no leite destinado ao consumo humano. Dessa forma, o objetivo desse estudo foi determinar os teores de nitrato nas pastagens e no leite ao longo de um ano em propriedades que utilizam níveis elevados de adubação nitrogenada no oeste de Santa Catarina (SC). O experimento foi realizado durante o período de abril/2018 a março/2019 em dez propriedades produtoras de leite do município de Riqueza (SC). Foram realizadas duas coletas anuais de amostras de água e coletas mensais de pastagens e leite, além de obtidas informações quanto ao manejo de adubação das pastagens da propriedade. O teste de difenilamina foi realizado nas pastagens. Dados de temperatura e pluviometria foram obtidos diariamente por uma estação meteorológica. A quantidade média de adubo nitrogenado utilizado nas propriedades foi de 654 ± 176 kg/ha/ano. O teor médio de nitrato na água de consumo dos animais foi de 1,5 ± 1,4 mg/L, na pastagem foi de 270 ± 76 mg/kg MS, enquanto no leite foi de 2,0 ± 0,3mg/L. Houve variação sazonal com aumento no teor de nitrato nas pastagens e no leite no outono, período do experimento em que foi observado baixo índice pluviométrico. Concluiu-se que apesar de se tratar de propriedades leiteiras com elevada utilização de adubação nitrogenada, o leite produzido é seguro quanto aos teores de nitrato, mesmo em épocas do ano com condições climáticas adversas. O teste de difenilamina pode ser indicado como teste rápido para verificar teores elevados de nitrato na pastagem

La renovación de la palabra en el bicentenario de la Argentina : los colores de la mirada lingüística

El libro reúne trabajos en los que se exponen resultados de investigaciones presentadas por investigadores de Argentina, Chile, Brasil, España, Italia y Alemania en el XII Congreso de la Sociedad Argentina de Lingüística (SAL), Bicentenario: la renovación de la palabra, realizado en Mendoza, Argentina, entre el 6 y el 9 de abril de 2010. Las temáticas abordadas en los 167 capítulos muestran las grandes líneas de investigación que se desarrollan fundamentalmente en nuestro país, pero también en los otros países mencionados arriba, y señalan además las áreas que recién se inician, con poca tradición en nuestro país y que deberían fomentarse. Los trabajos aquí publicados se enmarcan dentro de las siguientes disciplinas y/o campos de investigación: Fonología, Sintaxis, Semántica y Pragmática, Lingüística Cognitiva, Análisis del Discurso, Psicolingüística, Adquisición de la Lengua, Sociolingüística y Dialectología, Didáctica de la lengua, Lingüística Aplicada, Lingüística Computacional, Historia de la Lengua y la Lingüística, Lenguas Aborígenes, Filosofía del Lenguaje, Lexicología y Terminología

Revistas de arquitetura, urbanismo, paisagismo e design: a divergência de perspetivas

Trata de estabelecer as características atuais de revistas de arquitetura, urbanismo, paisagismo e design publicados no Brasil para um possível enquadramento como periódicos científicos ou técnicos. Comenta uma metodologia corrente de avaliação de publicações científicas de outras áreas de conhecimento e contextualiza sua aplicação diante da natureza diversificada da produção científica da área de arquitetura e urbanismo

Determinação de uma zona de hibridização entre tres formas cromossomicas de ctenomys minutus nehing, 1887 (rodentia - octodontidae)

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Characterization of a hybrid zone between chromosomally divergent populations of ctenomys minutus (rodentia: ctenomyidae)

This paper describes a stable chromosomal polymorphism in a species of tuco-tuco (Ctenomys minutus) and examines the dynamics of a narrow hybrid zone between chromosomal races distributed parapatrically on the coastal plain of southeastern Brazil. A cytogenetic survey studied 132 specimens of C. minutus from 22 trapping sites within the contact zone and surrounding areas. Seven polymorphic sites were identified; at all other sites, 2n was fixed for 2n 5 46 or 48. A single chromosomal rearrangement is involved in the observed variation, which served as a diallelic Mendelian character in a Hardy–Weinberg analysis. Pooling polymorphic populations revealed that the mating system is random among genotypes (i.e., no mating bias is present or there is no purifying selection). Observed frequency of the metacentric chromosome follows a clinal variation. The hybrid zone is located along an ecotone, which could imply that exogenous selection is important in its maintenance. However, applying static-cline methodologies revealed weak exogenous selection, and it is possible that the hybrid zone could be the result of a relatively recent secondary contact with a width determined primarily by neutral diffusion. A historical scenario for the time, place or origin, and spread of the species and its chromosomal races is also presented

Um novo cariotipo para o genero cavia pallas, 1766 de uma população insular (rodentia, caviidae)

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Microsatellite analysis of a hybrid zone between chromosomally divergent populations of ctenomys minutus from southern brazil (rodentia: ctenomyidae)

This paper describes variation at 6 microsatellite loci in 107 specimens of Ctenomys minutus from a chromosomal hybrid zone on the coastal plain of southern Brazil. Of the 56 alleles uncovered in this study, 39.2% are exclusive to alternative cytotypes or the contact populations. Clinal variation is not obvious because there are no microsatellite fixed differences among chromosomally divergent populations, but variation at Hai 2 locus is gradual across the zone. The local populations are highly differentiated and structured. The moderate estimated values of gene flow follow an isolation-by-distance model, which predicts concentration of an allele or a homozygous genotype in patches with generations of individuals with limited dispersal and mating by proximity. Analysis of populations distantly localized from the contact zone probably will provide further insights in the genetic relationship among cytotypes

Caracterização de uma zona de hibridização cromossômica entre duas formas de ctenomys minutus Nehring, 1887 (rodentia-octodontidae)

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