Fertilización a la siembra con diferentes dosis de azufre en soja

El objetivo de este trabajo es determinar niveles críticos de azufre en el cultivo de soja. El ensayo se realizó durante la campaña 1999-2000 en el campo del productor Pigozzi Raul, ubicado a 10 Km. al noroeste de la localidad de Casilda, provincia de Santa Fe sobre la ruta nacional n° 33, sobre un suelo Hapludol Vértico (Soil Taxonomy, 1978) correspondiente a la serie Peyrano. El cultivar de soja utilizado fue NK JOKETA 4.6 grupo de madurez IV corto. La siembra se realizó el 5 de noviembre de 1999 en bloques completamente aleatorios, con cinco repeticiones en parcelas de seis metros de longitud con seis surcos separados 0.7 m, y una densidad de 35 plantas (20 por metro lineal de surco). La fertilización se realizó en forma manual un día posterior a la siembra. Se realizaron los siguientes tratamientos: Testigo, 50 Kg/ha de superfosfato triple de calcio, 50 Kg/ha SPT y 20 Kg/ha de urea perlada, 50 Kg/ha SPT, 19.5 Kg/ha de tiosulfato de amonio y 15 Kg/ha de urea, 50 Kg/ha de SPT, 39 Kg/ha de TS A y 10 Kg /ha de urea, 50 Kg/ha de SPT, 58.5 Kg/ha de TSA y 5 Kg/ha de urea; 50 Kg/ha de SPT, 78 Kg/ha de TSA. Los resultados obtenidos indicaron que no existi6 respuesta a la fertilización azufrada. Dicha falta de respuesta puede ser atribuida a las bajas precipitaciones ocurridas durante los meses de noviembre, diciembre y enero, coincidiendo este último con el periodo de llenado de granos. Los altos contenidos de S-So4 encontrados en el perfil del suelo a la siembra del cultivo y los niveles moderados de fosforo en suelo y aplicados con el fertilizante deben ser considerados como otras causas de la falta de respuesta a la fertilización

Variabilidad del método Folin-Denis en la determinación de equivalentes de ácido tánico en muestras de sorgo

The purpose of this work is to evaluate the influence of some factor that condition the variability of the Folin-Denis method to determine de equivalents of tannic acid in grain of sorghum. We studied the influence of the centrifugation previous to the spectrophotometric measurement. It was also studied the most convenient refluxed time for the extraction of tannic substances. The application of centrifugation to the aqueous extract after a night rest showed highly significant differences (p< 0,01) with respect to the sample without centrifugation. Considering both procedures, we got "r" 0,997 and the equation of regressi0n responds to y = 0,0627 + 1,033 x. The coefficient of variations fluctuates between 1,94 and 5,77 % for samples without centrifugation and between 0,71 and 3,85 % for samples with centrifugation. Therefore, in order to decrease the variability of the methods it is convenient to apply a ten-minute centrifugation at 5.000 rpm to the aqueous extract. It was determined that for the refluxe time there are no differences of extraction between 2 and 5 hours, though it tends to increase as time increases. For routine determinations a 3 hours refluxe extraction is enough but 5 hours are advisable for greater precision.El propósito del presente trabajo es evaluar la influencia de algunos factores que condicionan la variabilidad del método de Folin-Denis para determinar equivalentes de ácido tánico en grano de sorgo. Se estudió la influencia de la centrifugación previa a la medición espectrofotométrica y el tiempo de reflujo más conveniente para la extracción de sustancias tánicas. La aplicación de centrifugación al extracto acuoso, previo reposo de toda la noche, mostró diferencias altamente significativas (p<0,01) con respecto al testigo sin centrifugar. Entre ambos procedimientos se obtuvo "r" = 0,997 y la ecuación de regresión responde a y = 0,0627 + 1,033 x. Los coeficientes de variación oscilaron entre 1,94 y 5,77 % para muestras sin centrifugar y 0,71 a 3,85 % con centrifugación. Por 10 tanto para disminuir la variabilidad del método conviene aplicar una centrifugación de 10 minutos a 500,0 r.p.m. al extracto acuoso. Para el tiempo de reflujo se determinó que existen diferencias de extracción entre 2 y 5 horas, aunque tiende a aumentar a medida que se incrementa el tiempo. Para determinaciones de rutina es suficiente una extracción de tres horas de reflujo, aunque para mayor precisión se recomiendan 5 horas

Variaciones del contenido de sustancias astringentes en distintos híbridos de sorgo en diferentes estados de madurez

Variation data of tannic acid equivalents in kernels of 38 grain sorghum hybrids at three different stages: solft dough, hard dough and ripening time are presented here. By means cluster annalysis four groups are differentiated. 1) With low tannin values at three stages. II) With high values at soft dough with a decreasing trend. III) Idem II but with higher values IV) High values at soft doug, low at hard dough and highest values at ripening time

Theoretical approach based on Monte-Carlo simulations to predict the cell survival following BNCT

International audienceWe present here a very preliminary work on BNCT Dosimetry. The approach is as follows:A full Monte Carlo calculation is used to separate all dose components and determine the corresponding physical dose fractions with a realistic clinical model.These dose fractions are then used as mixed fields to predict cell-survivals and RBE values for a specific cell-line, thanks to the radiobiological model NanOxTM

A chromosome-level genome assembly enables the identification of the follicule stimulating hormone receptor as the master sex determining gene in the flatfish Solea senegalensis

Sex determination (SD) shows huge variation among fish and a high evolutionary rate, as illustrated by the Pleuronectiformes (flatfishes). This order is characterized by its adaptation to demersal life, compact genomes and diversity of SD mechanisms. Here, we assembled the Solea senegalensis genome, a flatfish of great commercial value, into 82 contigs (614 Mb) combining long- and short-read sequencing, which were next scaffolded using a highly dense genetic map (28,838 markers, 21 linkage groups), representing 98.9% of the assembly. Further, we established the correspondence between the assembly and the 21 chromosomes by using BAC-FISH. Whole genome resequencing of six males and six females enabled the identification of 41 SNP variants in the follicle stimulating hormone receptor (fshr) consistent with an XX / XY SD system. The observed sex association was validated in a broader independent sample, providing a novel molecular sexing tool. Fshr displayed differential gene expression between male and female gonads from 86 days post-fertilization, when the gonad is still an undifferentiated primordium, concomitant with the activation of amh and cyp19a1a, testis and ovary marker genes, respectively, in males and females. The Y-linked fshr allele, which included 24 non-synonymous variants and showed a highly divergent 3D protein structure, was overexpressed in males compared to the X-linked allele at all stages of gonadal differentiation. We hypothesize a mechanism hampering the action of the follicle stimulating hormone driving the undifferentiated gonad toward testis.info:eu-repo/semantics/acceptedVersio

Productive Parvovirus B19 Infection of Primary Human Erythroid Progenitor Cells at Hypoxia Is Regulated by STAT5A and MEK Signaling but not HIFα

Human parvovirus B19 (B19V) causes a variety of human diseases. Disease outcomes of bone marrow failure in patients with high turnover of red blood cells and immunocompromised conditions, and fetal hydrops in pregnant women are resulted from the targeting and destruction of specifically erythroid progenitors of the human bone marrow by B19V. Although the ex vivo expanded erythroid progenitor cells recently used for studies of B19V infection are highly permissive, they produce progeny viruses inefficiently. In the current study, we aimed to identify the mechanism that underlies productive B19V infection of erythroid progenitor cells cultured in a physiologically relevant environment. Here, we demonstrate an effective reverse genetic system of B19V, and that B19V infection of ex vivo expanded erythroid progenitor cells at 1% O2 (hypoxia) produces progeny viruses continuously and efficiently at a level of approximately 10 times higher than that seen in the context of normoxia. With regard to mechanism, we show that hypoxia promotes replication of the B19V genome within the nucleus, and that this is independent of the canonical PHD/HIFα pathway, but dependent on STAT5A and MEK/ERK signaling. We further show that simultaneous upregulation of STAT5A signaling and down-regulation of MEK/ERK signaling boosts the level of B19V infection in erythroid progenitor cells under normoxia to that in cells under hypoxia. We conclude that B19V infection of ex vivo expanded erythroid progenitor cells at hypoxia closely mimics native infection of erythroid progenitors in human bone marrow, maintains erythroid progenitors at a stage conducive to efficient production of progeny viruses, and is regulated by the STAT5A and MEK/ERK pathways

The impact of depuration on mussel hepatopancreas bacteriome composition and predicted metagenome

Due to the rapid elimination of bacteriathrough normal behaviour of filter feeding and excretion,the decontamination of hazardous contaminatingbacteria from shellfish is performed by depuration.This process, under conditions that maximize shellfishfiltering activity, is a useful method to eliminatemicroorganisms from bivalves. The microbiota compositionin bivalves reflects that of the environment ofharvesting waters, so quite different bacteriomeswould be expected in shellfish collected in differentlocations. Bacterial accumulation within molluscanshellfish occurs primarily in the hepatopancreas. Inorder to assess the effect of the depuration process onthese different bacteriomes, in this work we used 16SRNA pyrosequencing and metagenome prediction toassess the impact of 15 h of depuration on the wholehepatopancreas bacteriome of mussels collected inthree different locations.Keywords Mussel depuration 16S RNAsequencing Taxonomic profiling Metagenomepredictio

Multiphysics study of the draining transients in the Molten Salt Fast Reactor

International audienc

On the use of inverse problem methods in nuclear reactors design applications

International audienc