28 research outputs found
INFLUENCIA DE LAS CITOQUINNIAS Y LOS SUBCULTIVOS EN LA CAPACIDAD DE PROLIFERACIÓN DE MICROESQUEJES AXILARES DE VITIS VINIFERA L. CV. NAPOLEÓN
The addition of cytokinins to the culture medium was essential for the sprouting and formation of multiple shoots from axillary-bud microcuttings excised from in vitro-grown plants of Vitis vinifera L. cv. Napoleón. Of three cytokinins assayed, 6-benzyladenine (BA), kinetin (K), 2- isopentenyladenine (2iP), and thidiazuron (TDZ), BA encouraged the best morphogenic response. This is especially true at concentrations of 6.67 and 8.9 M which led to 100% sprouting, an average of 8.7 axillary buds and 2.5 shoots developed per explant, together with maximum multiplication coefficients of buds and shoots. Subculture of microcuttings to fresh media maintained sprouting rates and substantially increased the production of shoots and axillary buds per explant until the third subculture. According to the results obtained it could seem advisable to limit the multiplication cycles for cv. Napoleón to three since further transfers induced vitrification phenomema and degenerations.La adición de citoquininas al medio de cultivo fue esencial para la brotación y formación de numerosos brotes a partir de microesquejes con yemas axilares obtenidos de plántulas crecidas in Vitro de Vitis vinifera L. cv. Napoleón. De las tres citoquininas ensayadas, 6- enciladenina (BA), kinetina (K), 2-isopenteniladenina (2iP), y tidiazuron (TDZ), BA fue la que mejor respuesta mofogénica dió. Las concentraciones de 6,67 y 8,9 M de BA provocaron un 100% de brotación, una media de 8,7 yemas axilares y 2,5 brotes desarrollados por explante inicial, junto con coeficientes de multiplicación de yemas y brotes máximos. El subcultivo de los microesquejes a medio freco mantuvo las tasas de brotación e incrementó sustancialmente la roducción de yemas y brotes axilares por explante hasta el tercer subcultivo. Según los resultados obtenidos, debería limitarse los ciclos de multiplicación para el cultivar Napoleón hasta tres ya que más subcultivos indujeron fenómenos de vitrificación y degeneración de los brotes
ESTABLECIMIENTO Y PROPAGACIÓN CLONAL IN VITRO DEL CULTIVAR AUTÓCTONO ESPAÑOL DE UVA DE MESA NAPOLEÓN: UN SISTEMA MEJORADO DONDE LOS CULTIVOS EN PROLIFERACIÓN ALTERNAN CON LOS DE ENRAIZAMIENTO
MS-1 and C2D media both contained 2 mg/l of 6-benzyladenine (BA) led to the best results of six culture media assayed for in vitro establishment of shoot tips from the table grapevine cultivar Napoleon. The parameters considered were survival, viability, number of axillary buds and shoots developing per explant, main shoot length and percentage of explants with secondary shoots. The viability and production of axillary buds and shoots were seriously affected by the time of the year when the buds were collected. The developmental stage of the axillary buds and the position of the nodal segments on the growing shoots taken from the mother plant signifi cantly infl uenced the in vitro response. The production of axillary buds and shoots, and the length of the main developed stem, significantly increased with distance from the shoot tips. A combined and sequential micropropagation protocol where proliferating cultures of axillary-bud microcuttings from in vitro-grown plants alternate with rooting cultures of the resulting shoots is described, and its commercial exploitation by the nursery industry is discussed.Ambos medios de cultivo, MS-1 y C2D, con 2 mg/l de 6-benciladenina (BA) dieron los mejores resultados de los seis medios ensayados para el establecimiento in vitro de ápices del cultivar de uva de mesa Napoleón. Se consideraron los parámetros de supervivencia, viabilidad, número de yemas axilares, desarrollo de brotes por explante, longitud del tallo principal y porcentaje de explantes con tallos secundarios. La viabilidad y producción de las yemas y brotes axilares se afectaron seriamente por la época del año en la que se recolectaron las yemas. El estado de desarrollo de las yemas axilares y la posición de los segmentos nodalessobre los brotes en crecimiento tomados de la planta madre infl uenciaron significativamente la respuesta in vitro. La producción de yemas axilares y brotes, y la longitud del tallo principal desarrollado, aumentaron significativamente con la distancia desde el ápice del brote. Se describe un protocolo combinado y secuencial de micropropagación donde alternan cultivos en proliferación de explantes axilares de plántulas crecidas in vitro con cultivos de enraizamiento de los brotes resultantes, y se discute su explotación comercial en la industria viverística
Veinte años (para la arquitectura contemporánea) no son nada…¿O sí?
Veinte años no son nada, dice el tango, pero no es cierto. Hace veinte años, en 1999, se derribó de manera incalificable uno de los edificios más paradigmáticos y significativos de la arquitectura española del siglo
XX, los Laboratorios Jorba (Madrid, 1965), del arquitecto Miguel Fisac..
Triku: a feature selection method based on nearest neighbors for single-cell data
Abstract
BACKGROUND: Feature selection is a relevant step in the analysis of single-cell RNA sequencing datasets. Most of the current feature selection methods are based on general univariate descriptors of the data such as the dispersion or the percentage of zeros. Despite the use of correction methods, the generality of these feature selection methods biases the genes selected towards highly expressed genes, instead of the genes defining the cell populations of the dataset.
RESULTS: Triku is a feature selection method that favors genes defining the main cell populations. It does so by selecting genes expressed by groups of cells that are close in the k-nearest neighbor graph. The expression of these genes is higher than the expected expression if the k-cells were chosen at random. Triku efficiently recovers cell populations present in artificial and biological benchmarking datasets, based on adjusted Rand index, normalized mutual information, supervised classification, and silhouette coefficient measurements. Additionally, gene sets selected by triku are more likely to be related to relevant Gene Ontology terms and contain fewer ribosomal and mitochondrial genes.
CONCLUSION: Triku is developed in Python 3 and is available at https://github.com/alexmascension/triku.This work was supported by grants from Instituto de Salud
Carlos III (AC17/00012 and PI19/01621), cofunded by the Euro-
pean Union (European Regional Development Fund/European Sci-
ence Foundation, Investing in your future) and the 4D-HEALING
project (ERA-Net program EracoSysMed, JTC-2 2017); Diputación
Foral de Gipuzkoa, and the Department of Economic Devel-
opment and Infrastructures of the Basque Government (KK-
2019/00006, KK-2019/00093); European Union FET project Cir-
cular Vision (H2020-FETOPEN, Project 899417), Ministry of Sci-
ence and Innovation of Spain; and PID2020-119715GB-I00 funded
by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of
making Europe. A.M.A. was supported by a Basque Govern-
ment Postgraduate Diploma fellowship (PRE_2020_2_0081), and
O.I.S. was supported by a Postgraduate Diploma fellowship from
la Caixa Foundation (identification document 100010434; code
LCF/BQ/IN18/11660065)
Myocardial injury determination improves risk stratification and predicts mortality in COVID-19 patients
Background: Despite being associated with worse prognosis in patients with COVID-19, systematic determination of myocardial injury is not recommended. The aim of the study was to study the effect of myocardial injury assessment on risk stratification of COVID-19 patients.Methods: Seven hundred seven consecutive adult patients admitted to a large tertiary hospital with confirmed COVID-19 were included. Demographic data, comorbidities, laboratory results and clinical outcomes were recorded. Charlson comorbidity index (CCI) was calculated in order to quantify the degree of comorbidities. Independent association of cardiac troponin I (cTnI) increase with outcomes was evaluated by multivariate regression analyses and area under curve. In addition, propensity-score matching was performed to assemble a cohort of patients with similar baseline characteristics.Results: In the matched cohort (mean age 66.76 ± 15.7 years, 37.3% females), cTnI increase above the upper limit was present in 20.9% of the population and was associated with worse clinical outcomes, including all-cause mortality within 30 days (45.1% vs. 23.2%; p = 0.005). The addition of cTnI to a multivariate prediction model showed a significant improvement in the area under the time-dependent receiver operating characteristic curve (0.775 vs. 0.756, DC-statistic = 0.019; 95% confidence interval 0.001–0.037). Use of renin–angiotensin–aldosterone system inhibitors was not associated with mortality after adjusting by baseline risk factors.Conclusions: Myocardial injury is independently associated with adverse outcomes irrespective of baseline comorbidities and its addition to multivariate regression models significantly improves their performance in predicting mortality. The determination of myocardial injury biomarkers on hospital admission and its combination with CCI can classify patients in three risk groups (high, intermediate and low) with a clearly distinct 30-day mortality