Influência da técnica de quebra de dormência, substrato e tamanho da semente na germinação do taperebá procedentes de duas populações nativas da Amazônia Central

Spondias mombin (taperebá) é uma espécie frutífera da Amazônia, com grande potencial de uso agroindustrial e consumo “in natura”. No entanto, alguns problemas fitotécnicos persistem, dentre os quais a germinação irregular e sua má distribuição ao longo do tempo. Neste sentido, avaliamos a influência da técnica de quebra de dormência, substrato e tamanho da semente na germinação do taperebá procedentes de duas populações nativas da Amazônia Central. O estudo foi desenvolvido em casa de vegetação no Instituto de Ciências Exatas e Tecnologia (ICET) – UFAM, no município de Itacoatiara, Amazonas.  A amostragem dos frutos foi realizada em duas localidades distintas de populações nativas. De cada local de amostragem utilizamos 100 frutos, sendo divididos em quatro amostras para realizar a caracterização morfoagronômica, determinando o peso, diâmetro, comprimento do fruto, peso da casca sem polpa, porcentagem de polpa, teor de umidade, diâmetro da semente, comprimento e peso da semente. Foi utilizado o delineamento experimental em blocos casualizados em esquema fatorial 4x2x2, totalizando 16 tratamentos por local de coleta. Os fatores estudados foram, quebra de dormência (corte distal, temperatura à 100oC/5 minutos, temperatura à 50oC/5 minutos, testemunha), substrato (areia e terra da mata + esterco + cinza) e tamanho do endocarpo (grande e pequeno). Os resultados demonstraram que as sementes de taperebá podem ser influenciadas pelos locais de procedências, afetando as variáveis de emergência, velocidade e o tempo médio de emergência

Residuos de desmote de algodón aglomerados: su producción y aplicación en la construcción de viviendas

La factibilidad de producir bloques y placas mediante la aglomeración de residuos de desmote del algodón (cascarilla) con ligantes cálcicos se ha comprobado en trabajos previos. Estos residuos representan un serio inconveniente para las plantas desmotadoras, que anualmente generan gran cantidad de desechos sin destino final identificado en Argentina. La variabilidad de la producción anual de algodón, la dispersión geográfica de las desmotadoras y los costos de transporte, dificultan proponer alternativas de reutilización de alta complejidad. Se propone emplearlo como materia prima para elaborar aglomerados de cascarilla con cemento portland utilizando tecnologías sencillas, fácilmente apropiables y transferibles. Este trabajo analiza las características de los aglomerados obtenidos y la influencia que ejercen diversos parámetros de producción sobre ellas y sobre la productividad del proceso. Los resultados alcanzados muestran la mejora de la productividad del proceso mediante el empleo de aditivos de calidad industrial, así como un mejor comportamiento higrotérmico de envolventes de viviendas por la incorporación de estos aglomerados, reemplazando materiales de elevado costo y tecnologías constructivas complejas

Specific Eco-evolutionary Contexts in the Mouse Gut Reveal Escherichia coli Metabolic Versatility

Members of the gut microbiota are thought to experience strong competition for nutrients. However, how such competition shapes their evolutionary dynamics and depends on intra- and interspecies interactions is poorly understood. Here, we test the hypothesis that Escherichia coli evolution in the mouse gut is more predictable across hosts in the absence of interspecies competition than in the presence of other microbial species. In support, we observed that lrp, a gene encoding a global regulator of amino acid metabolism, was repeatedly selected in germ-free mice 2 weeks after mono-colonization by this bacterium. We established that this specific genetic adaptation increased E. coli's ability to compete for amino acids, and analysis of gut metabolites identified serine and threonine as the metabolites preferentially consumed by E. coli in the mono-colonized mouse gut. Preference for serine consumption was further supported by testing a set of mutants that showed loss of advantage of an lrp mutant impaired in serine metabolism in vitro and in vivo. Remarkably, the presence of a single additional member of the microbiota, Blautia coccoides, was sufficient to alter the gut metabolome and, consequently, the evolutionary path of E. coli. In this environment, the fitness advantage of the lrp mutant bacteria is lost, and mutations in genes involved in anaerobic respiration were selected instead, recapitulating the eco-evolutionary context from mice with a complex microbiota. Together, these results highlight the metabolic plasticity and evolutionary versatility of E. coli, tailored to the specific ecology it experiences in the gut.info:eu-repo/semantics/publishedVersio

Progress and remaining challenges for cancer control in Latin America and the Caribbean :

Cancer is one of the leading causes of mortality worldwide, and an increasing threat in low-income and middle-income countries. Our findings in the 2013 Commission in The Lancet Oncology showed several discrepancies between the cancer landscape in Latin America and more developed countries. We reported that funding for health care was a small percentage of national gross domestic product and the percentage of health-care funds diverted to cancer care was even lower. Funds, insurance coverage, doctors, health-care workers, resources, and equipment were also very inequitably distributed between and within countries. We reported that a scarcity of cancer registries hampered the design of credible cancer plans, including initiatives for primary prevention. When we were commissioned by The Lancet Oncology to write an update to our report, we were sceptical that we would uncover much change. To our surprise and gratification much progress has been made in this short time. We are pleased to highlight structural reforms in health-care systems, new programmes for disenfranchised populations, expansion of cancer registries and cancer plans, and implementation of policies to improve primary cancer prevention

Neotropical ornithology: Reckoning with historical assumptions, removing systemic barriers, and reimagining the future

A major barrier to advancing ornithology is the systemic exclusion of professionals from the Global South. A recent special feature, Advances in Neotropical Ornithology, and a shortfalls analysis therein, unintentionally followed a long-standing pattern of highlighting individuals, knowledge, and views from the Global North, while largely omitting the perspectives of people based within the Neotropics. Here, we review current strengths and opportunities in the practice of Neotropical ornithology. Further, we discuss problems with assessing the state of Neotropical ornithology through a northern lens, including discovery narratives, incomplete (and biased) understanding of history and advances, and the promotion of agendas that, while currently popular in the north, may not fit the needs and realities of Neotropical research. We argue that future advances in Neotropical ornithology will critically depend on identifying and addressing the systemic barriers that hold back ornithologists who live and work in the Neotropics: unreliable and limited funding, exclusion from international research leadership, restricted dissemination of knowledge (e.g., through language hegemony and citation bias), and logistical barriers. Moving forward, we must examine and acknowledge the colonial roots of our discipline, and explicitly promote anti-colonial agendas for research, training, and conservation. We invite our colleagues within and beyond the Neotropics to join us in creating new models of governance that establish research priorities with vigorous participation of ornithologists and communities within the Neotropical region. To include a diversity of perspectives, we must systemically address discrimination and bias rooted in the socioeconomic class system, anti-Blackness, anti-Brownness, anti-Indigeneity, misogyny, homophobia, tokenism, and ableism. Instead of seeking individual excellence and rewarding top-down leadership, institutions in the North and South can promote collective leadership. In adopting these approaches, we, ornithologists, will join a community of researchers across academia building new paradigms that can reconcile our relationships and transform science. Spanish and Portuguese translations are available in the Supplementary Material.• Research conducted by ornithologists living and working in Latin America and the Caribbean has been historically and systemically excluded from global scientific paradigms, ultimately holding back ornithology as a discipline.• To avoid replicating systems of exclusion in ornithology, authors, editors, reviewers, journals, scientific societies, and research institutions need to interrupt long-held assumptions, improve research practices, and change policies around funding and publication.• To advance Neotropical ornithology and conserve birds across the Americas, institutions should invest directly in basic field biology research, reward collective leadership, and strengthen funding and professional development opportunities for people affected by current research policies.Peer reviewe