46 research outputs found

    Crecimiento y rendimiento de plantaciones forestales: Un análisis del estado actual de las tendencias mundiales

    Get PDF
    Tree growth is variable because it depends on the genetic heritage of individuals, their environment, the stage of development and the action of man. The objective of this study is to present an updated and comprehensive review of the state of the art on growth and yield of forest plantations, which identifies the research conducted and aspects that remain unknown. The planted forest area worldwide increased considerably between 1990 and 2015 from 167.5 to 277.9 M ha; in 2012, worldwide, 46.3% of industrial roundwood came from forest plantations. In recent years there has been increased interest in understanding the effects of the environment on wood properties; the productivity of forest plantations is a function of supply, harvest and resource use efficiency; several different traits can be modified through genetic improvement, such as more vigorous growth, resistance to pests or diseases, or product quality. It is essential to know the biology of the species to be established in plantations and the agro-ecological characteristics of the area to be planted, in addition to defining the destination objectives of the production. Research should provide a more complete understanding of the physiological processes, the efficiency of the use of resources that control the development of wood, and the genetic improvement.El crecimiento de los árboles es variable ya que depende del patrimonio genético del individuo, su entorno, de la etapa de desarrollo y la acción del hombre. El objetivo del presente ensayo es presentar una revisión actualizada e integral del estado del arte sobre crecimiento y rendimiento de las plantaciones forestales, con el cual se identifican las investigaciones realizadas y aspectos que faltan por conocer. La superficie forestal plantada a nivel mundial se incrementó considerablemente entre 1990 y 2015 de 167.5 a 277.9 M ha, en el año 2012 a nivel mundial 46.3% de la madera en rollo industrial procedió de plantaciones forestales. En años recientes ha aumentado el interés por conocer los efectos del ambiente sobre las propiedades de la madera; la productividad de las plantaciones forestales está en función del suministro, captura y eficiencia en el uso de los recursos; varios rasgos diferentes pueden modificarse a través del mejoramiento genético, como un crecimiento más vigoroso, resistencia a plagas o enfermedades o la calidad del producto. Resulta indispensable conocer la biología de las especies a establecer en plantaciones y las características agroecológicas del área a plantar, además de definir los objetivos de destino de la producción. Las investigaciones deben proporcionar una comprensión más completa sobre los procesos fisiológicos, la eficiencia del uso de recursos que controlan el desarrollo de la madera y sobre mejoramiento genético

    An environmental dependence of the physical and structural properties in the Hydra cluster galaxies

    Get PDF
    The nearby Hydra cluster (∼50 Mpc) is an ideal laboratory to understand, in detail, the influence of the environment on the morphology and quenching of galaxies in dense environments. We study the Hydra cluster galaxies in the inner regions (1R200) of the cluster using data from the Southern Photometric Local Universe Survey, which uses 12 narrow and broad-band filters in the visible region of the spectrum. We analyse structural (Sérsic index, effective radius) and physical (colours, stellar masses, and star formation rates) properties. Based on this analysis, we find that ∼88 per cent of the Hydra cluster galaxies are quenched. Using the Dressler–Schectman test approach, we also find that the cluster shows possible substructures. Our analysis of the phase-space diagram together with density-based spatial clustering algorithm indicates that Hydra shows an additional substructure that appears to be in front of the cluster centre, which is still falling into it. Our results, thus, suggest that the Hydra cluster might not be relaxed. We analyse the median Sérsic index as a function of wavelength and find that for red [(u − r) ≥2.3] and early-type galaxies it displays a slight increase towards redder filters (13 and 18 per cent, for red and early type, respectively), whereas for blue + green [(u − r)<2.3] galaxies it remains constant. Late-type galaxies show a small decrease of the median Sérsic index towards redder filters. Also, the Sérsic index of galaxies, and thus their structural properties, do not significantly vary as a function of clustercentric distance and density within the cluster; and this is the case regardless of the filter.CL-D acknowledges scholarship from CONICYT-PFCHA/Doctorado Nacional/2019-21191938. CL-D and AM acknowledge support from FONDECYT Regular grant 1181797. CL-D acknowledges also the support given by the ‘Vicerrectoría de Investigacion de la Universidad de La Serena’ program ‘Apoyo al fortalecimiento de grupos de investigacion’. CL-D and AC acknowledges to Steven Bamford and Boris Haeussler with the MegaMorph project. CL-D and DP acknowledge support from fellowship ‘Becas Doctorales Institucionales ULS’, granted by the ‘Vicerrectoría de Investigacion y Postgrado de la Universidad de La Serena’. AM and DP acknowledge funding from the Max Planck Society through a ‘Partner Group’ grant. DP acknowledges support from FONDECYT Regular grant 1181264. This work has used the computing facilities of the Laboratory of Astroinformatics (Instituto de Astronomia, Geofísica e Ciencias Atmosféricas, Departamento de Astronomia/USP, NAT/Unicsul), whose purchase was made possible by FAPESP (grant 2009/54006-4) and the INCT-A. YJ acknowledges financial support from CONICYT PAI (Concurso Nacional de Inserción en la Academia 2017) No. 79170132 and FONDECYT Iniciación 2018 No. 11180558. LS thanks the FAPESP scholarship grant 2016/21664-2. AAC acknowledges support from FAPERJ (grant E26/203.186/2016), CNPq (grants 304971/2016-2 and 401669/2016-5), and the Universidad de Alicante (contract UATALENTO18-02). AMB thanks the FAPESP scholarship grant 2014/11806-9. RA acknowedges support from ANID FONDECYT Regular grant 1202007

    The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data

    Get PDF
    This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys

    Brazilian guidelines for the clinical management of paracoccidioidomycosis

    Full text link

    A ética do silêncio racial no contexto urbano: políticas públicas e desigualdade social no Recife, 1900-1940

    Get PDF
    Mais de meio século após o preconceito racial ter se tornado o principal alvo dos movimentos urbanos pelos direitos civis nos Estados Unidos e na África do Sul, e décadas depois do surgimento dos movimentos negros contemporâneos no Brasil, o conjunto de ferramentas legislativas criado no Brasil para promover o direito à cidade ainda adere à longa tradição brasileira de silêncio acerca da questão racial. Este artigo propõe iniciar uma exploração das raízes históricas desse fenômeno, remontando ao surgimento do silêncio sobre a questão racial na política urbana do Recife, Brasil, durante a primeira metade do século XX. O Recife foi eé um exemplo paradigmático do processo pelo qual uma cidade amplamente marcada por traços negros e africanos chegou a ser definida política e legalmente como um espaço pobre, subdesenvolvido e racialmente neutro, onde as desigualdades sociais originaram na exclusão capitalista, e não na escravidão e nas ideologias do racismo científico. Neste sentido, Recife lança luzes sobre a política urbana que se gerou sob a sombra do silêncio racial.More than half a century after racial prejudice became central to urban civil rights movements in the United States and South Africa, and decades after the emergence of Brazil’s contemporary Black movements, Brazil's internationally recognized body of rights-to-the-city legislation still adheres to the country's long historical tradition of racial silence. This article explores the historical roots of this phenomenon by focusing on the emergence of racial silence in Recife, Brazil during the first half of the 20th Century. Recife was and remains a paradigmatic example of the process through which a city marked by its Black and African roots came to be legally and politically defined as a poor, underdeveloped and racially neutral space, where social inequalities derived from capitalist exclusion rather than from slavery and scientific racism. As such, Recife'sexperience sheds light on the urban policies that were generated in the shadow of racial silence

    Brazilian coffee genome project: an EST-based genomic resource

    Full text link

    Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

    Get PDF
    Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure &lt;= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

    Ajuste y selección de modelos matemáticos para predecir el volumen fustal de Tectona grandis L. f. en Nuevo Urecho, Michoacán, México

    No full text
    Abstract The objective was to adjust and select a mathematical model to predict the stem volume of Tectona grandis L. f. in an 11-year-old plantation in Nuevo Urecho, Michoacan. The sample analyzed was 128 trees, in which it was measured the stump diameter, normal diameter and diameters to different sections, from stump height to total height. Six stem volume models were adjusted using the SAS 9.2® statistical package Model procedure. The selection of the model was made from the total square error (SCE), the root mean square error (REMC) and R2 adj as well as the significance of their parameters. Compliance with the assumptions of normality, homogeneity of variances and independence of waste frequency was verified. A rating criterion was generated that ranked each statistics according to the order of importance, with the best being those with the lowest value in the overall rating. Meyer's model was the best fit with SCE= 0.0399, REMC= 0.0179 and R2 adj= 0.8246. The Shapiro-Wilk test (0.97), White´s Test (13.00), Durbin-Watson (2.0112) do not violate the regression assumptions and guarantee the effectiveness of the model for the estimation of the dependent variable. This model is considered appropriate to predict more accurately the stem volume as a function of the normal diameter (d) and total height (AT) of T. grandis in plantations with physical and biological conditions similar to those of the site of this study.Resumen El objetivo fue ajustar y seleccionar un modelo matemático para predecir el volumen fustal de Tectona grandis L. f. en una plantación de 11 años de edad en Nuevo Urecho, Michoacán. La muestra analizada fue de 128 árboles, a los que se les midió el diámetro de tocón, diámetro normal y el diámetro a distintas secciones, desde la altura de tocón hasta altura total. Se ajustaron seis modelos de volumen fustal mediante el procedimiento Model del paquete estadístico SAS 9.2®. La selección del modelo se hizo a partir de la suma de cuadrados del error (SCE), la raíz del error medio cuadrático (REMC) y R2 adj además de la significancia de sus parámetros. Se verificó el cumplimiento de los supuestos de normalidad, homogeneidad de varianzas e independencia de la frecuencia de residuos. Se generó un criterio de calificación que jerarquizó cada estadístico en función al orden de importancia, siendo mejores aquellos con el valor más bajo en la calificación total. El modelo de Meyer fue el de mejor ajuste con SCE= 0.0399, REMC= 0.0179 y R2 adj= 0.8246. La prueba de Shapiro-Wilk (0.97), White´s Test (13.00) y la de Durbin-Watson (2.0112) no violan los supuestos de la regresión y garantizan la eficacia del modelo para la estimación de la variable dependiente. Este modelo se considera apropiado para predecir con mayor precisión el volumen fustal en función del diámetro normal (d) y la altura total (AT) de T. grandis en plantaciones con condiciones físicas y biológicas similares a las del sitio de este estudio
    corecore