Convergent adaptations: bitter manioc cultivation systems in fertile anthropogenic dark earths and floodplain soils in central Amazonia

Shifting cultivation in the humid tropics is incredibly diverse, yet research tends to focus on one type: long-fallow shifting cultivation. While it is a typical adaptation to the highly-weathered nutrient-poor soils of the Amazonian terra firme, fertile environments in the region offer opportunities for agricultural intensification. We hypothesized that Amazonian people have developed divergent bitter manioc cultivation systems as adaptations to the properties of different soils. We compared bitter manioc cultivation in two nutrient-rich and two nutrient-poor soils, along the middle Madeira River in Central Amazonia. We interviewed 249 farmers in 6 localities, sampled their manioc fields, and carried out genetic analysis of bitter manioc landraces. While cultivation in the two richer soils at different localities was characterized by fast-maturing, low-starch manioc landraces, with shorter cropping periods and shorter fallows, the predominant manioc landraces in these soils were generally not genetically similar. Rather, predominant landraces in each of these two fertile soils have emerged from separate selective trajectories which produced landraces that converged for fast-maturing low-starch traits adapted to intensified swidden systems in fertile soils. This contrasts with the more extensive cultivation systems found in the two poorer soils at different localities, characterized by the prevalence of slow-maturing high-starch landraces, longer cropping periods and longer fallows, typical of previous studies. Farmers plant different assemblages of bitter manioc landraces in different soils and the most popular landraces were shown to exhibit significantly different yields when planted in different soils. Farmers have selected different sets of landraces with different perceived agronomic characteristics, along with different fallow lengths, as adaptations to the specific properties of each agroecological micro-environment. These findings open up new avenues for research and debate concerning the origins, evolution, history and contemporary cultivation of bitter manioc in Amazonia and beyond

Genetic Diversity and Differentiation of Brazilian Bitter and Sweet Manioc Varieties (Manihot esculenta Crantz, Euphorbiaceae) Based on SSR Molecular Markers

Manioc (Manihot esculenta Crantz) originated in Amazonia and is the main staple for more than 800 million people worldwide; it also had a fundamental role as a source of calories for many pre-Columbian peoples, especially in Amazonia, where it was domesticated. There are two major groups of manioc varieties: sweet varieties have low amounts of toxic substances (cyanogenic glycosides) and may be consumed with minimum processing, while bitter varieties have a high degree of toxicity and must be detoxified to be safe before consumption. These groups are outcomes of divergent selective pressures. Natural selection probably maintains large amounts of cyanogenic glycosides to serve as a plant defense when in cultivation. Human selection may reduce the toxicity of the plants when roots are directly consumed, but may be neutral when the roots are consumed after some kind of processing. Although farmers recognize the distinction of the two groups of varieties, the variation of cyanogenic glycosides is continuous among different varieties. Genetic differentiation between sweet and bitter varieties was detected with molecular markers, as well as different patterns of groupings of varieties from different regions of Brazil. The genetic distinctions suggest that the sweet varieties originated during the initial domestication in southwestern Amazonia and bitter varieties arose later during cultivation in Amazonia, as hypothesized by Arroyo-Kalin in a recent paper. They also suggest that these groups of varieties were dispersed independently, even though they are cultivated complementarily today, with sweet varieties in home-gardens and bitter varieties in swiddens

Finding the origin of domestication of cupuaçu requires more than genomics

Colli-Silva et al.1 recently proposed that cupuaçu (Theobroma grandiflorum) was domesticated in northwestern Amazonia as a selection from its sister species, cupuí (T. subincanum). This proposal ignores long-term research in taxonomy, botany, biogeography, and genetics about Theobroma, including cupuaçu. Our review of the research that was ignored and of Colli-Silva et al.’s results demonstrates that cupuaçu is a valid species, as they now agree2, but cupuí may be paraphyletic, the distribution of wild cupuaçu was not included in their samples so the origin of domestication continues unknown, precolonial archaeology lacks remains that can be attributed to either species, historical linguistics indicates that the term cupuaçu references the species’ wild distribution and is a recent introduction in northwestern Amazonia, history suggests that cupuaçu started to be domesticated during the last 100-200 years, and the genomics results are not about the domestication of cupuaçu because it is a valid species and its wild distribution was not sampled

Avaliação de Desempenho da Política EBS para Escalonamento em Aplicações com Restrições de Máximo Tempo Médio de Resposta

Este trabalho apresenta uma avaliação de desempenho do algoritmo EBS como política de escalonamento em aplicações cientes de QoS sob requisitos temporais tipo soft real-time.  O estudo analisa parâmetros que descrevem a carga de trabalho e avalia seu impacto na capacidade de atender à especificação de limites superiores de tempo médio de resposta.  O algoritmo EBS implementa uma política de escalonamento de prioridade dinâmica para aplicações de tempo-real flexível, a qual tem sido investigada em arquiteturas de escalonamento realimentado e escalomaneto dinâmico on-line.  São apresentados experimentos e resultados que analisam a influência dos fatores considerados na métrica de SLA

Relationship between the rs333 Polymorphism in the CC Chemokine Receptor Type Five (CCR5) Gene and Immunological Disorders: Data from a Meta-Analysis

Introduction: Inflammatory Bowel Disease (IBD), periodontitis and Systemic Lupus Erythematous (SLE) are multifactorial diseases, one of the factors in the course of these diseases is the rs333 polymorphism in the CC chemokine receptor type five (CCR5) gene. However, the results remain contradictory. Therefore, we aimed to perform a meta-analysis evaluating the relation between this polymorphism and the aforementioned conditions. Material and Methods: A search in the literature was performed in diverse scientific and medical databases for studies published before June 22, 2020. The data were extracted from the studies and the statistical evaluation was performed by the calculations of statistical heterogeneity (I²), Odds Ratio (OR) with 95% of Confidence Intervals (CI) and publication bias. The values of P<0.05 were considered as significant for all calculations. Results: 19 articles with 21 case/control studies in 4,304 case patients and 3,492 controls were included. The meta-analysis showed a non-significant association among the rs333 polymorphism and IBD (OR = 1.05, 95% CI: 0.91-1.20, P = 0.51), periodontitis (OR = 0.86, 95% CI: 0.64-1.17, P = 0.34) or SLE (OR = 1.00, 95% CI: 0.56-1.80, P = 1.00) under the allelic model or for any other performed calculation. There were no obvious publication bias in the analyses. Conclusion: In conclusion, this current meta-analysis evidenced the non-significant relation among the rs333 polymorphism and the risk of IBD, periodontitis or SLE. Further studies are required to validate our data

Comportamento estomático e componentes do sistema antioxidante em cafeeiros sob estresse hídrico

Para o cafeeiro (Coffea arabica) existe uma comprovada relação positiva entre fechamento estomático e formação e acúmulo de H2O2. Entretanto, tal relação para a cultura sob restrição hídrica ainda não foi estudada. Avaliou-se o movimento estomático e a capacidade antioxidante em mudas de cafeeiro sob diferentes regimes hídricos. Mudas de cafeeiro cv. Catuaí IAC 99, com oito meses de idade, foram submetidas à capacidade de campo, suspensão gradativa e suspensão total da irrigação por um período de 21 dias. Foram realizadas avaliações do potencial hídrico (Ψw) foliar na antemanhã e resistência estomática, taxa transpiratória e déficit de pressão de vapor foram avaliados as 10h00 e 17h00. As determinações bioquímicas e enzimáticas foram realizadas em folhas coletadas às 17h00. Todas as avaliações e coletas foram realizadas em intervalos de três dias. Nas plantas em capacidade de campo não houve variação no Ψw durante o período de avaliação. Para a suspensão gradativa da irrigação, houve queda expressiva a partir dos 12 dias, chegando próximo a -2,5 Mpa, ao final do experimento. Já nas plantas em suspensão total da irrigação observou-se queda no Ψw a partir do sexto dia, chegando a -2,5 MPa aos 15 dias. A queda no Ψw para as plantas em suspensão gradual e total da irrigação refletiu em aumentos na resistência estomática e diminuição da taxa transpiratória, ocasionando aumento na formação de peróxido de hidrogênio e nos períodos finais, aumentos na peroxidação de lipídios. Em conseqüência obervaram-se aumentos na atividade das enzimas antioxidantes, bem como nos teores de ascorbato e dehidroascorbato, atuando na detoxificação dos radicais livres formados em função do estresse.Coffee (Coffea arabica) plants show a positive relationship between stomatal closure and formation and accumulation of H2O2. However, for coffee plants under water restriction such relationship has never been studied. The objective of the present study was evaluate the stomatal movement and the antioxidant capacity of coffee seedlings under different water regimes. Eight months old coffee seedlings of cv. Catuaí IAC 99 were submitted to field capacity, gradual and total suspension of irrigation during a period of 21 days. Evaluations of leaf water potential (Ψw) were performed in the beginning of the morning, and stomatal resistance, transpiration rate and vapor pressure deficit were determined at 10 am and 5 pm. All biochemical and enzymatic determinations were performed in leaves collected at 5 pm. Evaluations and samplings were performed at three days intervals. There was no variation in Ψw during the evaluated period for plants in field capacity. However, an expressive decrease of Ψw following day 12, reaching values near -2.5 MPa at the end of the experiment was observed for plants submitted to gradual suspension of irrigation. For plants submitted to total suspension of irrigation, Ψw decreases after the sixth day, reaching -2.5 MPa at day 15. The decay of Ψw in plants submitted to gradual and total suspension of irrigation reflected in increased stomatal resistance and in a decreased transpiration rate leading to an increase in hydrogen peroxide formation and, on final stages, increase in lipid peroxidation. As a conclusion, an increase in the activity of antioxidant enzymes as well as in the levels of ascorbate and dehydroascorbate was observed, which act in the detoxification of free radicals formed as result of the water stress

Caracterização do sistema de produção em propriedades leiteiras de economia familiar em Presidente Olegário - MG: Fase Cria de Fêmeas

Objetivou-se, com este estudo, caracterizar propriedades produtoras de leite, em economia familiar, no que diz respeito a aspectos relacionados à cria de fêmeas de reposição. Os dados foram provenientes de 12 propriedades, localizadas na região Noroeste de Minas Gerais, no município de Presidente Olegário; no período entre maio e junho de 2016. Os dados foram cadastrados em planilhas do software Sphinx® e as respostas agrupadas por meio de sua categorização e frequência. Os dados evidenciaram que as falhas no manejo da fase de cria se iniciam no cuidado com as vacas no pré-parto e se estendem até a desmama das bezerras; e essa combinação de falhas deverá afetar a eficiência da atividade leiteira. Na maioria das propriedades as instalações são inadequadas ou mal localizadas. A maioria dos produtores faz a cria das bezerras em piquetes coletivos e não usa critérios para o agrupamento, manejando conjuntamente machos e fêmeas de várias idades e, assim, prejudicando o desempenho individual. A alimentação é feita sem critério na maioria das propriedades, o que pode estar contribuindo para o aumento da ocorrência dos problemas sanitários relatados. Não há adoção de protocolo sanitário específico para as bezerras e a falta de cuidados profiláticos básicos expõe os animais a maiores incidências de doenças e desvia o foco do cuidado sanitário para o tratamento de animais doentes ao invés da prevenção das mesmas. As possibilidades de viabilização técnica e econômica da pecuária familiar se tornam menores face às limitações observadas na fase de cria

Caracterização do sistema de produção em propriedades leiteiras de economia familiar em Presidente Olegário - MG: Fase Recria de Fêmeas

Objetivou-se, com este trabalho, caracterizar propriedades produtoras de leite, em regime de economia familiar, no que diz respeito a aspectos relacionados à recria de fêmeas bovinas leiteiras. Os dados utilizados foram provenientes de 12 propriedades produtoras de leite, localizadas na região Noroeste de Minas Gerais, no município de Presidente Olegário, na comunidade de Cachoeirinha/Boa Vista; no período entre maio e junho de 2016. Após a coleta, os dados foram cadastrados em planilhas do software Sphinx® e realizado o agrupamento das respostas por meio de sua categorização e frequência. Os dados das propriedades avaliadas evidenciaram que a baixa escolaridade, predomínio de mão de obra familiar e baixa participação de vacas em lactação nos plantéis são características comuns aos produtores. Foram identificadas diversas deficiências que se iniciam na desmama das bezerras e perpassam todo o período compreendido até a primeira cobertura das novilhas. A maioria dos produtores faz oferta suplementar de alimentos volumosos e concentrados, no entanto, a ausência de critérios técnicos para a divisão de lotes e alimentação das novilhas podem estar contribuindo significativamente para a perda de eficiência técnica e econômica nos plantéis avaliados. O peso e idade à primeira cobertura não são adequados ao padrão racial adotado nas propriedades, o que juntamente com a falta de correto manejo sanitário, pode vir a prejudicar a futura vida produtiva das fêmeas de reposição, assim como o desfrute e o melhoramento genético dos plantéis

Desmoplastic fibroblastoma (collagenous fibroma) of the oral cavity

Desmoplastic fibroblastoma is benign soft tissue tumor, with fibroblastic or myofibroblastic origin, that rarely occurs in oral cavity. We reported the case of a 56-year-old man who presented a tumor in the left mandibular alveolar ridge, with slow and asymptomatic growth, with no osseous involvement. The tumor was sessile with lobulated surface, covered by healthy mucosa with erythematous areas. The lesion was excised and specimens sent to histopathology and immunohistochemistry. Histopathological exam showed a non-encapsulated fibroblastic proliferation, characterized by myofibroblasts, spindle and stellate fibroblasts with large or oval nuclei and bi or tri nucleation, immersed in an abundant hypocellular dense collagen stroma. Tumor cells were positive for vimentin, HHF35, α-smooth muscle actin and factor XIIIa. The diagnosis of desmoplastic fibroblastoma was based in the clinical history of absence of trauma related to the growth in the alveolar ridge, associated with macroscopic, microscopic and immunohistochemical features. The patient is free-diseases by eight month