Efecto de seis niveles de sedimento extraido de la Laguna de “Yahuarcocha” en el rendimiento de cultivo de fresa (fragaria spp)

Con la utilización de los fertilizantes químicos, en las últimas décadas, se ha conseguido aumentar la producción agropecuaria; pero, la productividad tiene sus límites, ya que el uso excesivo de estos fertilizantes a dado como resultado la pérdida de las características físicas, químicas y biológicas del suelo y el agotamiento de las reservas de Materia Orgánica del Suelo (MOS), promoviendo el desequilibrio de los ecosistemas (Reina J, 2002). Hasta la aparición de los abonos químicos, los agro ecosistemas de cultivo permanecían estables, dependiendo la producción agrícola de la propia riqueza del suelo y de su regeneración mediante aportes orgánicos producidos dentro del propio agro ecosistema (raíces, pajas, hojas, estiércol, basuras, desperdicios urbanos, etc.); es decir, explotaban las tierras dentro de una “AGRICULTURA SOSTENIBLE” (Reina J, 2002). El mantenimiento de fertilidad de un suelo exige lograr un equilibrio entre la pérdida o salida de nutrientes, producto de la lixiviación, erosión, así como los exportados por los cultivos, y su reposición mediante aportes de fertilizantes químicos y de abonos orgánicos. La Materia Orgánica del suelo, ejerce un papel decisivo en su fertilidad, ya que mejora sus propiedades físicas, químicas y biológicas, de manera que incrementa la productividad del suelo (Vilatuña H, 2001). En los costos de producción de la mayoría de cultivos, la fertilización es uno de los rubros más altos que el agricultor debe afrontar; es por eso, que nos encontramos en una constante búsqueda de nuevas fuentes de nutrientes para las plantas, debiendo estas cumplir con la condición de ser más económica y con la característica no sólo de ser una fuente nutricional, sino también un mejorador de las características físico – químicas y biológicas del suelo (Brazanti E, 1989). En la actualidad como parte del macro proyecto de recuperación de la laguna de Yahuarcocha, que lleva a cabo el Ilustre Municipio de Ibarra a través del Fondo de Salvamento del Patrimonio Cultural del Cantón Ibarra FONSALCI, se esta desarrollando el proceso de dragado de la laguna, extrayéndose alrededor de 1500 toneladas semanales de lodo. Estudios preliminares con la utilización de estos sedimentos, en ensayos realizados en varios sitios por moradores de la zona; así como, por los encargados del proyecto, han demostrado que estos sedimentos proporcionan los nutrientes necesarios para poder establecer cultivos y potreros. Teniendo en cuenta, la gran cantidad de material extraído durante el proceso de dragado, y al no tener una propuesta especifica de uso, la falta de estudios técnicos, con respecto a la aplicación de sedimentos en la agricultura, como una fuente de nutrientes para las plantas se ve la necesidad de desarrollar el presente trabajo, con la finalidad de encontrar una utilidad que represente réditos económicos para la municipalidad, así como el de beneficiar a muchos agricultores a través de la utilización de un producto de alta calidad y de bajo costo, así como la de determinar cantidad optima de sedimento o lodo, proveniente de la laguna, adicionable o incorporable para la producción de fresa. El cultivo de fresa en la provincia de Imbabura, es un rubro importante para la economía de los agricultores, la provincia es una de las principales zonas productoras de fresa, dándose en los últimos tiempos un incremento notable en la superficie destinada al cultivo de esta especie. El objetivo de la presente investigación fue: Evaluar la incidencia del sedimento proveniente de la laguna de Yahuarcocha en el desarrollo fisiológico y productivo de la fresa (Fragaria spp). Específicamente se busco: Determinar la relación óptima de sedimento / suelo para alcanzar los mejores rendimientos en el cultivo de fresa. Evaluar el efecto del sedimento en las características físicas y químicas del suelo en estudio. Realizar un análisis económico de presupuesto parcial para determinar el mejor tratamiento de producción. Las hipótesis que se plantearon fueron: El sedimento proveniente de la laguna de Yahuarcocha no influye en la producción de fresa. El sedimento proveniente de la laguna de Yahuarcocha no altera las características físicas y químicas del suelo

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Neotropical freshwater fisheries : A dataset of occurrence and abundance of freshwater fishes in the Neotropics

The Neotropical region hosts 4225 freshwater fish species, ranking first among the world's most diverse regions for freshwater fishes. Our NEOTROPICAL FRESHWATER FISHES data set is the first to produce a large-scale Neotropical freshwater fish inventory, covering the entire Neotropical region from Mexico and the Caribbean in the north to the southern limits in Argentina, Paraguay, Chile, and Uruguay. We compiled 185,787 distribution records, with unique georeferenced coordinates, for the 4225 species, represented by occurrence and abundance data. The number of species for the most numerous orders are as follows: Characiformes (1289), Siluriformes (1384), Cichliformes (354), Cyprinodontiformes (245), and Gymnotiformes (135). The most recorded species was the characid Astyanax fasciatus (4696 records). We registered 116,802 distribution records for native species, compared to 1802 distribution records for nonnative species. The main aim of the NEOTROPICAL FRESHWATER FISHES data set was to make these occurrence and abundance data accessible for international researchers to develop ecological and macroecological studies, from local to regional scales, with focal fish species, families, or orders. We anticipate that the NEOTROPICAL FRESHWATER FISHES data set will be valuable for studies on a wide range of ecological processes, such as trophic cascades, fishery pressure, the effects of habitat loss and fragmentation, and the impacts of species invasion and climate change. There are no copyright restrictions on the data, and please cite this data paper when using the data in publications

A century of trends in adult human height

International audienc

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

The value of open-source clinical science in pandemic response: lessons from ISARIC

International audienc

ISARIC-COVID-19 dataset: A Prospective, Standardized, Global Dataset of Patients Hospitalized with COVID-19

The International Severe Acute Respiratory and Emerging Infection Consortium (ISARIC) COVID-19 dataset is one of the largest international databases of prospectively collected clinical data on people hospitalized with COVID-19. This dataset was compiled during the COVID-19 pandemic by a network of hospitals that collect data using the ISARIC-World Health Organization Clinical Characterization Protocol and data tools. The database includes data from more than 705,000 patients, collected in more than 60 countries and 1,500 centres worldwide. Patient data are available from acute hospital admissions with COVID-19 and outpatient follow-ups. The data include signs and symptoms, pre-existing comorbidities, vital signs, chronic and acute treatments, complications, dates of hospitalization and discharge, mortality, viral strains, vaccination status, and other data. Here, we present the dataset characteristics, explain its architecture and how to gain access, and provide tools to facilitate its use