The role of hydrodynamics in structuring in situ ammonium uptake within a submerged macrophyte community

In low-nutrient, macrophyte-dominated coastal zones, benthic ammonium (NH4+) uptake may be influencedby the structural properties of plant canopies via their effect on near-bed hydrodynamics. Using adual-tracer (uranine and 15NH4+) method that does not require enclosures, we examined how this processaffects nutrient uptake rates within a tidally dominated, patchy Caulerpa prolifera–Cymodocea nodosalandscape. NH4+ uptake was determined by calculating tissue 15N excesses and correcting for 15N enrichmentas derived from uranine concentration. Vertical hydrodynamic profiles were measured in thedownstream flow direction from outside to inside of the C. nodosa bed by using an array of acousticDoppler velocimeters. The transition from a C. prolifera to a C. nodosa bed included a change in bothbenthic canopy properties (short and dense to tall and sparse) and sediment topography (0.2-m increasein water column depth) that resulted in an increase in longitudinal advection and turbulent diffusivitywithin the C. nodosa canopy between 0.5 and 1.5mfrom the leading edge. Vertical differences in canopywater exchange appeared to explain variations in uptake between biotic functional groups; however, noclear differences in longitudinal uptake were found. Using in situ labeling, this study demonstrated for thefirst time the role of hydrodynamics in structuring NH4+ uptake within an undisturbed, patchy macrophytelandscape

First collection of landrace vegetable crops cultivated in Valle Fértil, Argentina

The richness of the cultural values found in the Argentinean Andean communities is integrated by a varied diversity of genetic resources, the development of a sustainable agriculture, and the conservation of the producer’s own seeds. Local agriculture is a family economic activity, in which traditional varieties of vegetable landraces are highly appreciated for their flavour, colour and aromas. However; social, economic and environmental factors have an effect on crop diversity conservation. The main aim of this work was to retrieve and maintain a representative collection of traditional crop genetic resources still cultivated in the District of Valle Fértil, San Juan Province, Argentina, and to document the farmers’ crop experiences and uses. Fifty families were interviewed; 26 of these donated a total of 49 samples belonging to eight species. The landraces collected showed a geometric distribution, typical of communities with low number of species; and a pattern of dominance. A few species are present in almost all farms while rare species are found in specific environments. Local germplasm recovery can prevent genetic erosion, so that both the formal breeding sector and the farmers can make use of the diversity of this collection.La riqueza cultural de las comunidades andinas de la Argentina está integrada por la diversidad de sus recursos genéticos, el desarrollo de un sistema agrícola sostenible y por el mantenimiento de sus semillas. La agricultura local es una actividad económica familiar, donde las variedades tradicionales de hortalizas son muy apreciadas por su sabor, color y aroma. Sin embargo, distintos factores sociales, económicos y ambientales afectan la diversidad de tales cultivos. Los objetivos de este trabajo fueron recuperar y conservar una muestra representativa de los recursos genéticos vegetales tradicionales aún presentes en el departamento de Valle Fértil, provincia de San Juan, Argentina, y documentar las experiencias y usos de ellos por parte de los productores. Se entrevistaron 50 familias de las cuales 26 donaron un total de 49 muestras pertenecientes a ocho especies. Las variedades criollas recolectadas mostraron una distribución geométrica típica en comunidades con pocasespecies, y un patrón de dominancia donde algunas especies están presentes en casi todas las huertas mientras que especies poco representadas se encuentran en ambientes específicos. La recuperación del germoplasma local puede prevenir la erosión genética, de modo que tanto los mejoradores como los productores puedan aprovechar la diversidad de esta colección

Wild tomato endosperm transcriptomes reveal common roles of genomic imprinting in both nuclear and cellular endosperm

Genomic imprinting is a conspicuous feature of the endosperm, a triploid tissue nurturing the embryo and synchronizing angiosperm seed development. An unknown subset of imprinted genes (IGs) is critical for successful seed development and should have highly conserved functions. Recent genome‐wide studies have found limited conservation of IGs among distantly related species, but there is a paucity of data from closely related lineages. Moreover, most studies focused on model plants with nuclear endosperm development, and comparisons with properties of IGs in cellular‐ type endosperm development are lacking. Using laser‐assisted microdissection, we characterized parent‐specific expression in the cellular endosperm of three wild tomato lineages (Solanum section Lycopersicon). We identified 1025 candidate IGs and 167 with putative homologs previously identified as imprinted in distantly related taxa with nuclear‐type endosperm. Forty‐two maternally expressed genes (MEGs) and 17 paternally expressed genes (PEGs) exhibited conserved imprinting status across all three lineages, but differences in power to assess imprinted expression imply that the actual degree of conservation might be higher than that directly estimated (20.7% for PEGs and 10.4% for MEGs). Regardless, the level of shared imprinting status was higher for PEGs than for MEGs, indicating dissimilar evolutionary trajectories. Expression‐level data suggest distinct epigenetic modulation of MEGs and PEGs, and gene ontology analyses revealed MEGs and PEGs to be enriched for different functions. Importantly, our data provide evidence that MEGs and PEGs interact in modulating both gene expression and the endosperm cell cycle, and uncovered conserved cellular functions of IGs uniting taxa with cellular‐ and nuclear‐type endosperm

Caracterización morfológica y de calidad de germoplasma de Capsicum colectado en el noroeste de Argentina

Paprika production is concentrated in Northwestern Argentina, where around 1500 ha are annually grown. Farmers mainly from Andean valleys, maintain their local landraces or "criollas" under different environmental conditions, using their farming traditions and selection criteria. These traditional varieties represent valuable genetic resources for conservation and selection of agronomical and quality traits. Between 2005 and 2007 eight collecting trips were made to Northwestern Argentina in order to recover local germplasm. As a result, five hundred new vegetable seed samples have been incorporated into the Germplasm Bank. Among these accessions 32 belong to Capsicum, the majority for paprika production, that were evaluated in field conditions using a randomized block design with three repetitions of eight plants per accession; 54 morphological and agronomical traits were measured during two production cycles. Multivariate analyses determine three groups, where fruit characters were the most efficient for accession differentiation. Accessions suitable for paprika production were further examined, and variability for fruit pungency and color was found. Promising accessions were selected for ex situ conservation and breeding purposes.La producción de pimiento para pimentón se concentra en el noroeste de la Argentina, donde anualmente se cultivan unas 1500 hectáreas. En los valles andinos los agricultores mantienen sus variedades locales o “criollas” en diferentes condiciones ambientales y siguiendo sus tradiciones agrícolas y criterios de selección. Estas variedades son recursos genéticos valiosos para la conservación y selección de caracteres agronómicos y de calidad. Entre 2005 y 2007 se realizaron ocho viajes a dicha zona, con el fin de recuperar el germoplasma local. Como resultado 500 nuevas muestras de semillas de hortalizas se han incorporado en el Banco de Germoplasma. Entre ellas 32 entradas de Capsicum, la mayoría utilizadas para la producción de pimentón, que se evaluaron a campo mediante un diseño de bloques al azar con tres repeticiones de ocho plantas por entrada, y se midieron 54 caracteres morfológicos y agronómicos durante dos ciclos de producción. El análisis multivariado determinó tres grupos, donde los caracteres del fruto fueron más eficientes para la diferenciación de las entradas. Se estudiaron en particular las entradas para la producción de pimentón, encontrándose variabilidad en el picor y en el color del fruto. Las entradas promisorias fueron seleccionadas para su conservación ex situ y mejoramiento

Caracterización morfo-agronómica de poblaciones de zapallo criollo (cucurbita maxima Duch.) colectadas en los valles andinos de la Argentina

In the Andean valleys of Argentina, families grow vegetables by traditional methods, mainly for self-consumption. Squash (Cucurbita maxima) is an American crop of great importance in Andean regional economies. These squash landraces are being lost by the rural exodus, the replacement of local varieties with commercial seeds and frequent droughts. They are reservoirs of genes of interest for improving the species and for ensuring local food security; their conservation and characterization are thus fundamental to avoiding genetic erosion. During 2005, sixty-one populations were collected from Valle Fértil, San Juan Province, and from the Argentinian northwest. Twentyseven were selected and tested for two years in the EEA INTA La Consulta, Mendoza. Forty-nine characters of plant, flower, fruit and seed were measured under a completely randomized design with three repetitions per population. Commercial cultivars Marino FCA and Veronés INTA were used as controls. The populations were grouped by fruit, seed and growth habit characters; a great morphological diversity was observed among and within populations. The work allowed selection of materials with desirable traits for improving the species.En los valles andinos de la Argentina las familias producen hortalizas en forma tradicional principalmente para el autoconsumo. El zapallo (Cucurbita maxima) es un cultivo americano de gran importancia en las economías regionales andinas. Estas poblaciones criollas de zapallos se están perdiendo por el éxodo rural, la sustitución de semilla criolla por semilla comercial y las sequías frecuentes. Constituyen reservorios de genes de interés para el mejoramiento y para garantizar la seguridad alimentaria local, por lo que su conservación y caracterización son fundamentales para evitar la erosión genética. Durante 2005 se realizaron colectas en Valle Fértil, provincia de San Juan y en el noroeste argentino; se colectaron 61 poblaciones, de las cuales 27 se seleccionaron y evaluaron durante dos años en la EEA La Consulta INTA, Mendoza. Se midieron 49 caracteres de planta, flor, fruto y semilla, bajo un diseño experimental completamente aleatorizado y tres repeticiones por población. Los cultivares comerciales Marino FCA y Veronés INTA se emplearon como testigos. Las poblaciones se agruparon por caracteres de fruto, hábito de crecimiento y semilla, observándose gran diversidad morfológica entre y dentro de cada población. El trabajo permitió seleccionar materiales con caracteres de interés para el mejoramiento de la especie

First collection of landrace vegetable crops cultivated in Valle Fértil, Argentina Primera colección de hortalizas criollas cultivadas en Valle Fértil, Argentina

The richness of the cultural values found in the Argentinean Andean communities is integrated by a varied diversity of genetic resources, the development of a sustainable agriculture, and the conservation of the producer's own seeds. Local agriculture is a family economic activity, in which traditional varieties of vegetable landraces are highly appreciated for their flavour, colour and aromas. However; social, economic and environmental factors have an effect on crop diversity conservation. The main aim of this work was to retrieve and maintain a representative collection of traditional crop genetic resources still cultivated in the District of Valle Fértil, San Juan Province, Argentina, and to document the farmers' crop experiences and uses. Fifty families were interviewed; 26 of these donated a total of 49 samples belonging to eight species. The landraces collected showed a geometric distribution, typical of communities with low number of species; and a pattern of dominance. A few species are present in almost all farms while rare species are found in specific environments. Local germplasm recovery can prevent genetic erosion, so that both the formal breeding sector and the farmers can make use of the diversity of this collection.La riqueza cultural de las comunidades andinas de la Argentina está integrada por la diversidad de sus recursos genéticos, el desarrollo de un sistema agrícola sostenible y por el mantenimiento de sus semillas. La agricultura local es una actividad económica familiar, donde las variedades tradicionales de hortalizas son muy apreciadas por su sabor, color y aroma. Sin embargo, distintos factores sociales, económicos y ambientales afectan la diversidad de tales cultivos. Los objetivos de este trabajo fueron recuperar y conservar una muestra representativa de los recursos genéticos vegetales tradicionales aún presentes en el departamento de Valle Fértil, provincia de San Juan, Argentina, y documentar las experiencias y usos de ellos por parte de los productores. Se entrevistaron 50 familias de las cuales 26 donaron un total de 49 muestras pertenecientes a ocho especies. Las variedades criollas recolectadas mostraron una distribución geométrica típica en comunidades con pocas especies, y un patrón de dominancia donde algunas especies están presentes en casi todas las huertas mientras que especies poco representadas se encuentran en ambientes específicos. La recuperación del germoplasma local puede prevenir la erosión genética, de modo que tanto los mejoradores como los productores puedan aprovechar la diversidad de esta colección

Development of a Novel Low-Cost Exoscope to Expand Access to Microneurosurgical Care in Low- and Middle-Income Countries

Background: Less than a quarter of the world population has access to microneurosurgical care within a range of 2 hours. We introduce a simplified exoscope system to achieve magnification, illumination, and video recording in low-resource settings. Methods: We combined an industrial microscope tube, a heavy-duty support arm, a wide-field c-mount digital microscope camera, and a light-emitting diode ring light. All parts were sterilized with ethylene oxide. We performed 13 spinal and 3 cranial surgeries with the help of the low-budget exoscope. Results: The average preoperative setup time was 12.8 minutes. The exoscope provided similar magnification and illumination like a conventional binocular microscope. It allowed operating in a comfortable posture. The field of vision ranged from 30 mm–60 mm. The surgical field was captured by a 16-megapixel two-dimensional camera and projected to a 55-inch high-definition television screen in real time. Image quality was similar to that of a conventional microscope although our exoscope lacked stereoscopic view. Adjusting camera position and angle was time-consuming. Thus, the benefit of the exoscope was most notable in spine surgeries where the camera remained static for most of the time. The total cost of the exoscope was approximately U.S. $ 750. Conclusions: Our low-budget exoscope offers similar image quality, magnification, and illumination like a conventional binocular microscope. It may thus help expand access to neurosurgical care worldwide. Users may face difficulty adapting to the lack of depth perception in the beginning. Prospective studies are needed to assess its usability and effectiveness compared to the microscope. © 2022 Elsevier Inc