Assessing soil N availability indices - is inorganic N enough?

Non-Peer ReviewedAssessing soil N availability is complicated enormously by the complexity of the N-cycle. Over the years, several methods of estimating potentially available N have been suggested. In an ongoing study, we have been assessing the suitability of a number of these methods for predicting potential crop response to fertilizer N. In particular, we correlated amino-sugar N levels to wheat yield across a variable landscape. This relatively new soil N test appears to be sensitive to changes in organic matter quality as related to landscape position and holds some promise for assessing potentially available N. The results presented here are preliminary

Practical Based Learning (PBL) for Academic, Technological and Scientific Education in Engineering Courses - Case Study

The increase in the number of students evaded has alerted different segments of society and the public sector to the need to update the guidelines of engineering courses as well as innovation in teaching engineering. In this sense, the objective is to report on the challenges of engineering education in Brazil and the methodological strategies that have been adopted for the modernization of the curricula of engineering courses and consequent reduction of the indicators of avoidance and withdrawal. In addition, involving the use of the 43 academic academics of the University of Cruz Alta (Unicruz) who studied the discipline of Research Methodology in the second semester of 2017 through the Problem Based Learning (PBL) strategy as an innovative strategy education. Finally, in addition to the production of a technical material produced throughout the course, it was observed that there were only 2 students in 1 failed exam, demonstrating that teaching by PBL has high effectiveness for academic achievement in the discipline of research methodology

Influence of the soil on sensorial characteristics of Petit Verdot tropical wines from the Northeast of Brazil.

The objective of this work was to evaluate Petit Verdot varietal wines elaborate from grapes of vines cultivated in three types of soils, sandy, gravelly and clayey, different on physical and chemical characteristics, being sandy and clayey argisoils and gravelly cambosoil, by enologists

Influence of the soil on sensorial characteristics of Petit Verdot tropical wines from the Northeast of Brazil.

The objective of this work was to evaluate Petit Verdot varietal wines elaborate from grapes of vines cultivated in three types of soils, sandy, gravelly and clayey, different on physical and chemical characteristics, being sandy and clayey argisoils and gravelly cambosoil, by enologists

Influence of soil attributes on ?Petit Verdot? productivity in the São Francisco Valley, Brazil

The São Francisco Valley is a pioneer in the production of fine grapes for wine. The region has excelled on the national economy, being the only region in the world that produces two harvests a year. Studies aiming to characterize the potential grapevine growing regions indicate the potential of several cultivars adapted to local conditions and suitable to contribute for the typicality of the grapevine products of the region, as for example, the Petit Verdot cultivar (Ibravin, 2012). Some soil attributes, important to grape and wine quality, are related to water and nutrient availability (Leewen et al., 2004; Wang et al., 2015). The objective of this work is to relate the physical and chemical properties of soils to the productivity of the vine, Petit Verdot cultivar, in the São Francisco Valley

Predictors of Hepatocellular Carcinoma Early Recurrence in Patients Treated with Surgical Resection or Ablation Treatment: A Single-Center Experience

Introduction: Hepatocellular carcinoma (HCC) is the sixth most diagnosed malignancy and the fourth leading cause of cancer-related death worldwide, with poor overall survival despite available curative treatments. One of the most crucial factors influencing survival in HCC is recurrence. The current study aims to determine factors associated with early recurrence of HCC in patients with BCLC Stage 0 or Stage A treated with surgical resection or local ablation. Materials and Methods: We retrospectively enrolled 58 consecutive patients diagnosed with HCC within BCLC Stage 0 or Stage A and treated either by surgical resection or local ablation with maximum nodule diameter 20 mm (HR 4.5, 95% C.I. 3.9–5.1), platelet count 2 (HR 2.7, 95% C.I. 2.2–3.3). Discussion and Conclusions: Our results are in line with the current literature. Male gender and tumor nodule dimension are the main risk factors associated with early HCC recurrence. Platelet count and other combined scores can be used as predictive tools for early HCC recurrence, although more studies are needed to define cut-offs

DNA markers to disentangle complexes of cryptic taxa in mealybugs (Hemiptera: Pseudococcidae).

Mealybugs (Hemiptera: Pseudococcidae) are major pests of a wide range of crops and ornamental plants worldwide. Their high degree of morphological similarity makes them difficult to identify and limits their study and management. We aimed to identify a set of markers for the genetic characterization and identification of complexes of taxa in the Pseudococcidae. We surveyed and tested the genetic markers used in previous studies and then identified new markers for particularly relevant genomic regions for which no satisfactory markers were available. We tested all markers on a subset of four taxa distributed worldwide. Five markers were retained after this first screening: two regions of the mitochondrial cytochrome oxidase I gene, 28S-D2, the entire internal transcriber space 2 locus and the rpS15-16S region of the primary mealybug endosymbiont Tremblaya princeps. We then assessed the utility of these markers for the characterization and identification of 239 samples from 43 sites in France and Brazil. The five markers studied (i) successfully distinguished all species identified by morphological examination, (ii) disentangled complexes of species by revealing intraspecific genetic variation and identified a set of closely related taxa for which taxonomic status requires clarification through further studies, and (iii) facilitated the inference of phylogenetic relationships between the characterized taxa

Aplicação de sistemas de avaliação da aptidão agrícola das terras em solos do Estado do Acre, Amazônia.

Os métodos de avaliação da aptidão agrícola tem como objetivo orientar o uso adequado das terras, porém seus resultados apresentam elevado grau de subjetividade devido a serem dependentes da experiência do usuário. Neste trabalho objetivou-se avaliar o uso de um algoritmo para interpretação de propriedades do solo e características da paisagem e compará-lo com a interpretação obtida por um grupo controle, constituído por seis especialistas. Foram utilizadas amostras de solo coletadas por tradagem ao lado dos perfis pedológicos da IX Reunião Brasileira de Correlação e Classificação de Solos, de modo a obter os dados de entrada do algoritmo, enquanto os avaliadores utilizaram os dados físicos, químicos e morfológicos dos perfis pedológicos. A avaliação do grupo controle não identificou as potencialidades para o uso dos solos na Amazônia de forma consistente, enquanto, o algoritmo mostrou-se promissor na avaliação da aptidão para Latossolo, Argissolos, Vertissolos e Luvissolo, no entanto, ainda requer revisões em algumas regras de interpretação para uma avaliação mais coerente da aptidão, principalmente, para o Espodossolo

Evidence for an Invasive Aphid “Superclone”: Extremely Low Genetic Diversity in Oleander Aphid (Aphis nerii) Populations in the Southern United States

The importance of genetic diversity in successful biological invasions is unclear. In animals, but not necessarily plants, increased genetic diversity is generally associated with successful colonization and establishment of novel habitats. The Oleander aphid, Aphis nerii, though native to the Mediterranean region, is an invasive pest species throughout much of the world. Feeding primarily on Oleander (Nerium oleander) and Milkweed (Asclepias spp.) under natural conditions, these plants are unlikely to support aphid populations year round in the southern US. The objective of this study was to describe the genetic variation within and among US populations of A. nerii, during extinction/recolonization events, to better understand the population ecology of this invasive species.We used five microsatellite markers to assess genetic diversity over a two year period within and among three aphid populations separated by small (100 km) and large (3,700 km) geographic distances on two host plant species. Here we provide evidence for A. nerii "superclones". Genotypic variation was absent in all populations (i.e., each population consisted of a single multilocus genotype (MLG) or "clone") and the genetic composition of only one population completely changed across years. There was no evidence of sexual reproduction or host races on different plant species.Aphis nerii is a well established invasive species despite having extremely low genetic diversity. As this aphid appears to be obligatorily asexual, it may share more similarities with clonally reproducing invasive plants, than with other animals. Patterns of temporal and geographic genetic variation, viewed in the context of its population dynamics, have important implications for the management of invasive pests and the evolutionary biology of asexual species

Avaliação da aptidão agrícola de solos do Acre por diferentes especialistas.

Os sistemas de avaliação da aptidão ou do potencial agrícola das terras têm sido utilizados nas diversas regiões do Brasil, por várias equipes e com múltiplas aplicações. O objetivo deste trabalho foi avaliar, para solos no Estado do Acre, como diferentes especialistas percebem a importância relativa dos indicadores de um sistema de aptidão agrícola e como eles interpretam esses atributos para a definição das diferentes classes de aptidão. Foram utilizados 10 perfis de solos analisados para a IX Reunião Brasileira de Classificação e Correlação de Solos, localizados entre os municípios de Rio Branco e Cruzeiro do Sul, Amazônia - região caracterizada por sedimentos da Formação Solimões como material de origem dos solos. As interpretações da aptidão agrícola dos solos foram feitas por seis especialistas, os quais avaliaram os indicadores de aptidão agrícola, aplicando cinco graus dos fatores de limitação: deficiência de fertilidade, deficiência de água, deficiência de oxigênio, suscetibilidade à erosão e impedimentos à mecanização. A partir desses fatores, foram estabelecidas as classes e os grupos de aptidão para cada perfil de solo, que foram comparados usando análise discriminante e por similaridade. Os resultados indicaram que as variáveis relacionadas a estoque de nutrientes, tipo de argila, classe textural e de drenagem e relevo local foram as mais relevantes na distinção dos ambientes pelos especialistas. A interpretação da aptidão agrícola por especialistas não foi inteiramente reproduzível para todos os solos, estando sujeita a variações decorrentes da experiência dos avaliadores e de seu conhecimento sobre o ambiente e os diferentes tipos de uso da terra