Modelo de arborización dendrítica basado en reconstrucciones de motoneuronas frénicas en ratas adultas

El área superficial de las dendritas en motoneuronas frénicas (PhrMNs) ha sido estimada anteriormente mediante técnicas estereológicas basadas en suposiciones geométricas, y medida en tres dimensiones (3D) utilizando microscopía confocal. Dado que el 97% del área receptora de una motoneurona corresponde a sus dendritas, la ramificación y extensión dendrítica son fisiológicamente importantes para determinar la salida de sus campos receptivos. Sin embargo, limitaciones inherentes a las estimaciones basadas en morfología neuronal y la tinción incompleta de los árboles dendríticos mediante técnicas retrógradas han dificultado los estudios sistemáticos de la morfología dendrítica en PhrMNs. En este estudio, se utilizó una nueva técnica que mejora la tinción dendrítica de las PhrMNs en preparaciones fijadas ligeramente. La reconstrucción dendrítica en 3D se logró con gran precisión utilizando microscopía confocal en PhrMNs de ratas adultas. Luego de una etapa de pre-procesamiento, la segmentación de los árboles dendríticos se realizó semi-automáticamente en 3D y usando mediciones directas del área superficial, se derivó un modelo cuadrático para estimar dicha área partiendo del diámetro de la dendrita primaria (r2 = 0.932; p<0.0001). Este método podría mejorar la evaluación de la plasticidad neuronal en respuesta a trauma u otras enfermedades permitiendo la estimación de la arborización dendrítica en PhrMNs, ya que el diámetro de la dendrita primaria puede obtenerse confiablemente de numerosas técnicas de tinción retrógrada.Stereological techniques that rely on morphological assumptions and direct three-dimensional (3D) confocal measurements have been previously used to estimate the dendritic surface areas of phrenic motoneurons (PhrMNs). Given that 97% of a motoneuron’s receptive area is provided by dendrites, dendritic branching and overall extension are physiologically important in determining the output of their synaptic receptive fields. However, limitations intrinsic to shape-based estimations and incomplete labeling of dendritic trees by retrograde techniques have hindered systematic approaches to examine dendritic morphology of PhrMNs. In this study, a novel method that improves dendritic filling of PhrMNs in lightly-fixed samples was used. Confocal microscopy allowed accurate 3D reconstruction of dendritic arbors from adult rat PhrMNs. Following pre-processing, segmentation was semi-automatically performed in 3D, and direct measurements of dendritic surface area were obtained. A quadratic model for estimating dendritic tree surface area based on measurements of primary dendrite diameter was derived (r2 = 0.932; p<0.0001). This method may enhance interpretation of motoneuron plasticity in response to injury or disease by permitting estimations of dendritic arborization of PhrMNs since measurements of primary dendrite diameter can be reliably obtained from a number of retrograde labeling techniques

PROPUESTA DE ESCISIÓN DE LA DENOMINADA ‘FORMACIÓN SILGARÁ’ (MACIZO DE SANTANDER, COLOMBIA), A PARTIR DE EDADES U-Pb EN CIRCONES DETRÍTICOS

La Formación Silgará (s.l.) aforante en el Macizo de Santander (Cordillera Oriental de Colombia) en la franja&nbsp;Matanza-Cachirí, presenta litologías metamórfcas fundamentalmente metapelíticas y metasemipelitas, las cuales &nbsp;alcanzaron el máximo pico de metamorfsmo en la facies Esquistos Verdes. Circones detríticos con edades U-Pb&nbsp;entre 906,5±10,5 Ma y 1.610,3±9,8 Ma, permiten determinar que la máxima edad de depositación del protolito&nbsp;de ésta unidad es Neo-proterozóico (Toniano). Contrariamente, la franja de rocas metamórfcas Piedecuesta-Aratoca (relacionada en trabajos previos con la denominada Formación Silgará s.l., propuesta desde la década&nbsp;de los 70s), presentan dos grupos de litologías diferentes: una compuesta fundamentalmente de metapsamitas,&nbsp;semipelitas y metabasitas (hacia la base), las cuales alcanzaron el máximo pico de metamorfsmo en la facies&nbsp;anfbolita; y otra de metapsamitas, semipelitas hacia la parte superior (en facies sub-esquistos verdes). Circones&nbsp;detríticos con edades U-Pb entre 506,7±9,3 Ma y 2.586,9±10,2 Ma, en cuarcitas de la facies anfbolita, apuntan&nbsp;a que la máxima edad de depositación del protolito de estas litologías metamórfcas estaría entre el Cámbrico temprano (Terreneuviano) a Cámbrico medio; mientras que en las cuarcitas de la facies sub-esquistos verdes,&nbsp;las edades entre 451,6±7,7 Ma y 1.611,5±13,6 Ma, sugieren que su máxima edad de depositación del protolito&nbsp;es Ordovícico tardío (Katian) y una historia paleogeográfca y sedimentológica muy diferente, en comparación&nbsp;con las litologías previamente referidas.&nbsp; Apoyados en las diferencias antes referidas, se propone escindir la Formación Silgará (s.l.) en tres unidades&nbsp;diferentes: Esquistos del Silgará s.s. (unidad fundamentalmente pelítica y semipelita), Esquistos del&nbsp;Chicamocha (unidad compuesta fundamentalmente de metapsamitas, metapelitas y metabasitas; y posiblemente&nbsp;litologías calco-silicatadas?, presentes en otros franjas metamórfcas del MS) y Filitas de San Pedro (unidad&nbsp;compuesta fundamentalmente de metapsamitas, metapelitas; y localmente muy posiblemente litologías meta-volcanoclásticas?). El pico de metamorfsmo de las unidades Esquistos del Silgará (s.s.) y del Chicamocha, se&nbsp;relacionan con el evento orogénico principal Fammatiniano (localmente referido como Quetame-Caparonensis,&nbsp;de edad Ordovícico temprano); mientras que el pico de metamorfsmo de la unidad Filitas de San Pedro, se&nbsp;relacionaría con el evento orogénico menor Fammatiniano (de edad Silúrico). Aunque los unidades Esquistos&nbsp;del Silgará (s.s.) y del Chicamocha, al parecer alcanzaron el máximo pico de metamorfsmo durante el evento&nbsp;orogénico principal Fammatiniano, aquí se propone su escisión, considerando sus diferencias litológicas (además&nbsp;de las diferencias ya referidas). No obstante, se recomienda un análisis comparativo más detallado entre las&nbsp;diferentes franjas metamórfcas esquistosas presentes en el Macizo de Santander (en términos de sus litologías&nbsp;predominantes y sus máximas edades estratigráfcas, entre otros aspectos), para fnes de soportar o descartar&nbsp;ésta división. En lo referente a la unidad Filitas de San Pedro (aquí propuesta), su escisión (individualización) es&nbsp;muy evidente y necesaria, debido a las diferencias litológicas y edad de metamorfsmo, respecto a las unidades&nbsp;previamente referidas. No se descarta la existencia de eventos tectono-termales más jóvenes en el Macizo de&nbsp;Santander (especialmente de tipo dinamo-térmico), considerando la presencia localizada de rocas sedimentarias,&nbsp;de edad Paleozóico tardío, afectadas por pizarrosidad.&nbsp;The metamorphic lithologies from the Silgará Formation (s.l.) outcropping along the Matanza-Cachirí strip in the Santander Massif (Colombian Eastern Cordillera) are mainly constituted by metapelites and metasemipelites&nbsp;that reached the thermal metamorphic peak in the range of green schist facies. Detrital zircons from these metamorphic lithologies yielded U-Pb ages from 906.5 ± 10.5 to 1610.3 ± 9.8 Ma, suggesting a maximum age of deposition at Neoproterozoic time. On the other hand, the Piedecuesta-Aratoca metamorphic rocks strip (also linked previously to the so-called Silgará Formation) is composed by two groups of lithologies: The lower sequence which is constituted mainly by meta-psamites, semipelites and metabasites with the thermal metamorphic peak at amphibolite facies and; the upper sequence which are basically meta-psamites&nbsp;and semipelites that reached the thermal metamorphic peak at sub-green schist facies. Detrital zircons from the quartzites in amphibolite facies rocks yielded U-Pb ages from 506.7± 9.3 to 2586.9±10.2 Ma, suggesting a maximum age of deposition at Early to Middle Cambrian time; whereas U-Pb zircon ages determinated from the meta-sandstones from the upper sequence yielded ages from 451.6±7.7 to 1611.5±13.6 Ma, suggesting a maximum age of deposition at Late Ordovician (Katina) time. These geochronology data point out that these both sequences have different paleogeographic and sedimentological history. &nbsp; Supported by the aforementioned differences, it is proposed here to split-off the older Silgará Formation (s.l.) in the following three different units: the Silgará schists s.s.(constituted by metapelitic and semipelitic rocks), the Chicamocha schists (mainly constituted by metapsammites, metapelites and metabasites, and possibly&nbsp;metacalcsilicates? rocks outcropping in some others metamorphic strips from the Santander Massif) and the San Pedro phyllites (constituted by metapsamites and metapelites and possibly metavolcanoclastic lithologies?). The thermal metamorphic peak of the Silgara (s.s.) and Chicamocha Schists units must be related to the main Fammatinian orogenic event (locally known as Quetame-Caparonensis, early Ordovician in age), whereas the metamorphic peak for the San Pedro Fillites unit should be related to the minor Fammatinian orogenic event (Silurian in age). Despite both The Silgará Schists (s.s.) and Chicamocha Schists units reached probably the thermal metamorphic peak during the Fammatinian Orogeny, here is proposed to split-off these units, because of these lithological differences (among some others aforementioned characteristics). Anyway, in order to avoid or to support this idea, there is a need to develop new studies, involving more metamorphic strips in order to identify better their lithologies and their maximum deposition ages. The split-off of the San Pedro Phyllites&nbsp;Unit from the Silgara Formation (s.l.) is evident and necessary task, considering their lithologies, metamorphic ages, among others features, compared with the Silgara Schists (s.s.) and Chicamocha Schists Units.Younger&nbsp;tectono-thermal events (mainly dynamo-thermal) are not ruled out, taking into account the local presence of late Paleozoic sedimentary rocks in the Santander Massif, affected by a slaty cleavag

ASPECTOS PETROGRAFICOS Y GEOQUIMICOS DE LAS ROCAS METAMORFICAS DEL SECTOR BARRANCO DE LOBA (SERRANIA DE SAN LUCAS)

&nbsp; The metamorphic rocks that outcrop in the San Lucas foothills (in the area covered by the map indentified as number 64), are grouped in two stratigraphic units: The so-called San Lucas Gneiss Formation and the Pinillos Metamorphic Unit (informal stratigraphic denomination). This latter unit is composed by The Armenia Schists and Tapoa Phyllites. The San Lucas Gneiss Formation, comprise quartz-feldspar gneisses (quartz-feldspar gneisses with biotite, quartz-feldspar gneisses with hornblende) and metamafic rocks (hornblende gneiss, granulites and metagabbros). The Armenia Schists is composed by pelite schists; such as micaceous schists; micáceous schists with andalusite; and calco-silicate schists, quartz rich and with variable amounts of minerals from epidote, hornblende and actinolite groups. The Tapoa Phyllite Rocks are composed by quartz and sericite with altered opaque minerals. The San Lucas Gneiss Formation Metamorphism is regional and reaches the high anfibolite and pyroxene granulites facies. The 1.124Ma ± 22 zircon U-Pb age, indicates a Mesoproterozoic tectonothermal event, related to the Grenville Orogeny, that took place during the Rodinia supercontinent consolidation. The Pinillos Metamorphic Rocks Unit, is Early Paleozoic in age, according to the field relations.&nbsp; Key words: Metamorphism, Serrania de San Lucas, San Lucas Gneiss Formation, Armenia Schist, Geochronology.Las rocas metamórficas aflorantes en la Plancha 64 (estribación NE de la Serranía de San Lucas, Cordillera Central), están agrupadas en dos unidades estratigráficas: una denominada formación Neis de San Lucas y otra unidad de carácter informal, denominada Unidad Metamórfica de Pinillos. Esta ultima, compuesta por los Esquistos de Armenia y las Filitas de Tapoa. El Neis de San Lucas, consiste en neises cuarzo-feldespáticos (neises cuarzo-feldespáticos con biotita, neises cuarzo-feldespáticos con hornblenda) y rocas metamáficas (neis hornblendico, granulitas, metagabros). Los Esquistos de Armenia, se componen de esquistos pelíticos, tales como esquistos micáceos y esquistos micáceos con andalusita, y esquistos calco-silicatados, los cuales son cuarzosos con cantidades variables de minerales del grupo de la epidota, hornblenda y actinolita. Las Filitas de Tapoa son rocas compuestas de cuarzo y sericita con minerales opacos alterados. El metamorfismo del Neis de San Lucas es regional, alcanzando las facies anfibolita alta y granulita piroxénica. Edades U-Pb en circones de esta formación, apunta a un evento tectonotermal del Mesoproterozoico (1124Ma±22 Ma), relacionado con la orogenia Grenviliana, durante la consolidación del supercontinente Rodinia. Las rocas de la Unidad Metamórfica de Pinillos, es considerada por sus relaciones de campo, como de edad Paleozoica Temprano. &nbsp;Palabras claves: Metamorfismo, Serranía de San Lucas, Formación Neis de San Lucas, Esquistos de Armenia, geocronología &nbsp;&nbsp; &nbsp

ASPECTOS PETROGRAFICOS Y GEOQUIMICOS DE LAS ROCAS METAMORFICAS DEL SECTOR BARRANCO DE LOBA (SERRANIA DE SAN LUCAS)

&nbsp; The metamorphic rocks that outcrop in the San Lucas foothills (in the area covered by the map indentified as number 64), are grouped in two stratigraphic units: The so-called San Lucas Gneiss Formation and the Pinillos Metamorphic Unit (informal stratigraphic denomination). This latter unit is composed by The Armenia Schists and Tapoa Phyllites. The San Lucas Gneiss Formation, comprise quartz-feldspar gneisses (quartz-feldspar gneisses with biotite, quartz-feldspar gneisses with hornblende) and metamafic rocks (hornblende gneiss, granulites and metagabbros). The Armenia Schists is composed by pelite schists; such as micaceous schists; micáceous schists with andalusite; and calco-silicate schists, quartz rich and with variable amounts of minerals from epidote, hornblende and actinolite groups. The Tapoa Phyllite Rocks are composed by quartz and sericite with altered opaque minerals. The San Lucas Gneiss Formation Metamorphism is regional and reaches the high anfibolite and pyroxene granulites facies. The 1.124Ma ± 22 zircon U-Pb age, indicates a Mesoproterozoic tectonothermal event, related to the Grenville Orogeny, that took place during the Rodinia supercontinent consolidation. The Pinillos Metamorphic Rocks Unit, is Early Paleozoic in age, according to the field relations.&nbsp; Key words: Metamorphism, Serrania de San Lucas, San Lucas Gneiss Formation, Armenia Schist, Geochronology.Las rocas metamórficas aflorantes en la Plancha 64 (estribación NE de la Serranía de San Lucas, Cordillera Central), están agrupadas en dos unidades estratigráficas: una denominada formación Neis de San Lucas y otra unidad de carácter informal, denominada Unidad Metamórfica de Pinillos. Esta ultima, compuesta por los Esquistos de Armenia y las Filitas de Tapoa. El Neis de San Lucas, consiste en neises cuarzo-feldespáticos (neises cuarzo-feldespáticos con biotita, neises cuarzo-feldespáticos con hornblenda) y rocas metamáficas (neis hornblendico, granulitas, metagabros). Los Esquistos de Armenia, se componen de esquistos pelíticos, tales como esquistos micáceos y esquistos micáceos con andalusita, y esquistos calco-silicatados, los cuales son cuarzosos con cantidades variables de minerales del grupo de la epidota, hornblenda y actinolita. Las Filitas de Tapoa son rocas compuestas de cuarzo y sericita con minerales opacos alterados. El metamorfismo del Neis de San Lucas es regional, alcanzando las facies anfibolita alta y granulita piroxénica. Edades U-Pb en circones de esta formación, apunta a un evento tectonotermal del Mesoproterozoico (1124Ma±22 Ma), relacionado con la orogenia Grenviliana, durante la consolidación del supercontinente Rodinia. Las rocas de la Unidad Metamórfica de Pinillos, es considerada por sus relaciones de campo, como de edad Paleozoica Temprano. &nbsp;Palabras claves: Metamorfismo, Serranía de San Lucas, Formación Neis de San Lucas, Esquistos de Armenia, geocronología &nbsp;&nbsp; &nbsp

Implementation of Malaria Dynamic Models in Municipality Level Early Warning Systems in Colombia. Part I: Description of Study Sites

As part of the Integrated National Adaptation Pilot project and the Integrated Surveillance and Control System, the Colombian National Institute of Health is working on the design and implementation of a Malaria Early Warning System framework, supported by seasonal climate forecasting capabilities, weather and environmental monitoring, and malaria statistical and dynamic models. In this report, we provide an overview of the local ecoepidemiologic settings where four malaria process-based mathematical models are currently being implemented at a municipal level. The description includes general characteristics, malaria situation (predominant type of infection, malaria-positive cases data, malaria incidence, and seasonality), entomologic conditions (primary and secondary vectors, mosquito densities, and feeding frequencies), climatic conditions (climatology and long-term trends), key drivers of epidemic outbreaks, and non-climatic factors (populations at risk, control campaigns, and socioeconomic conditions). Selected pilot sites exhibit different ecoepidemiologic settings that must be taken into account in the development of the integrated surveillance and control system

Legumes as food ingredient: characterization, processing, and applications

Editores: Jiménez-López, José Carlos (CSIC); Clemente, Alfonso (CSIC

Coinfection with Different Trypanosoma cruzi Strains Interferes with the Host Immune Response to Infection

A century after the discovery of Trypanosoma cruzi in a child living in Lassance, Minas Gerais, Brazil in 1909, many uncertainties remain with respect to factors determining the pathogenesis of Chagas disease (CD). Herein, we simultaneously investigate the contribution of both host and parasite factors during acute phase of infection in BALB/c mice infected with the JG and/or CL Brener T. cruzi strains. JG single infected mice presented reduced parasitemia and heart parasitism, no mortality, levels of pro-inflammatory mediators (TNF-α, CCL2, IL-6 and IFN-γ) similar to those found among naïve animals and no clinical manifestations of disease. On the other hand, CL Brener single infected mice presented higher parasitemia and heart parasitism, as well as an increased systemic release of pro-inflammatory mediators and higher mortality probably due to a toxic shock-like systemic inflammatory response. Interestingly, coinfection with JG and CL Brener strains resulted in intermediate parasitemia, heart parasitism and mortality. This was accompanied by an increase in the systemic release of IL-10 with a parallel increase in the number of MAC-3+ and CD4+ T spleen cells expressing IL-10. Therefore, the endogenous production of IL-10 elicited by coinfection seems to be crucial to counterregulate the potentially lethal effects triggered by systemic release of pro-inflammatory mediators induced by CL Brener single infection. In conclusion, our results suggest that the composition of the infecting parasite population plays a role in the host response to T. cruzi in determining the severity of the disease in experimentally infected BALB/c mice. The combination of JG and CL Brener was able to trigger both protective inflammatory immunity and regulatory immune mechanisms that attenuate damage caused by inflammation and disease severity in BALB/c mice

Chagas Cardiomyopathy Manifestations and Trypanosoma cruzi Genotypes Circulating in Chronic Chagasic Patients

Chagas disease caused by Trypanosoma cruzi is a complex disease that is endemic and an important problem in public health in Latin America. The T. cruzi parasite is classified into six discrete taxonomic units (DTUs) based on the recently proposed nomenclature (TcI, TcII, TcIII, TcIV, TcV and TcVI). The discovery of genetic variability within TcI showed the presence of five genotypes (Ia, Ib, Ic, Id and Ie) related to the transmission cycle of Chagas disease. In Colombia, TcI is more prevalent but TcII has also been reported, as has mixed infection by both TcI and TcII in the same Chagasic patient. The objectives of this study were to determine the T. cruzi DTUs that are circulating in Colombian chronic Chagasic patients and to obtain more information about the molecular epidemiology of Chagas disease in Colombia. We also assessed the presence of electrocardiographic, radiologic and echocardiographic abnormalities with the purpose of correlating T. cruzi genetic variability and cardiac disease. Molecular characterization was performed in Colombian adult chronic Chagasic patients based on the intergenic region of the mini-exon gene, the 24Sα and 18S regions of rDNA and the variable region of satellite DNA, whereby the presence of T.cruzi I, II, III and IV was detected. In our population, mixed infections also occurred, with TcI-TcII, TcI-TcIII and TcI-TcIV, as well as the existence of the TcI genotypes showing the presence of genotypes Ia and Id. Patients infected with TcI demonstrated a higher prevalence of cardiac alterations than those infected with TcII. These results corroborate the predominance of TcI in Colombia and show the first report of TcIII and TcIV in Colombian Chagasic patients. Findings also indicate that Chagas cardiomyopathy manifestations are more correlated with TcI than with TcII in Colombia

Anales de Edafología y Agrobiología Tomo 33 Número 9-10

Estudio del equilibrio nutritivo en cultivos de chirimoyo (Annona cherimolia), por César González O., Miguel Fuentes y Soledad Díaz.-- Resistencia a la desecación del tejido foliar y cierre de estomas en alfalfa (M edicago sativa L.) y trébol blanco (Trijolium repens L.) con relación al déficit agua, por M. Sánchez-Díaz y M. Sánchez-Marín.-- Determinación del calor isostérico y consideraciones sobre el mecanismo de la adsorción de fosfato por óxidos de hierro, por L. Madrid, F. Cabrera, P. de Arambarri y E. Díaz.-- Studies on sodium-calcium exchange equilibria. II. In Egyptian soils, by M. H. Nafady.-- Indices nutritivos en manzano (var. R. Delicious), por C. González, O. M. Rodríguez M., J. Solé D. y A. Wylie W.-- Caracteres de los suelos de las zonas citrícolas del valle de Murcia (España), por J. A. Sánchez F., F. Artes y J. López-Tarruella.-- Estudio micromorfológico de suelos desarrollados sobre andesitas en Andalucía oriental, por J. Aguilar y M. Delgado.-- Estudio edafológico de los relieves próximos a la vega de Motril, por J. Aguilar, Ruiz, A. Monge Ureña y C. Sierra Ruiz de la F.-- Consideraciones experimentales sobre el análisis de boro en plantas, por A. León, F.J. López-Andréu, F. Romojaro y C. Alcaraz.-- Efectos de la aplicación conjunta de fertilizantes químicos y microbianos (Azotobaeter Fosjobaeterias) en cultivos enarenados de tomate, por R. Azcón, M. Gómez y J. M. Barea.-- Formas de calcio en suelos del piso tropical de Barbacoas, Colombia, por G. Hugo Eraso, L. Federman Ortiz y O. Hernán Burbano.-- Compuestos íenólicos en Eriea vagans L., por J. Arinés, J. L. G. Mantilla y E. Vieitiz.-- Determinación de glúcidos en plantas por fotocolorimetría. Estudio comparativo de métodos clásicos y automáticos, por C. Cadahía y M. T. Piñeiro.-- Notas. Nombramiento de Consejeros Adjuntos del Patronato Alonso de Herrera.-- Nombramiento y cese de Vocales de la Junta de Gobierno del Patronato Alonso de Herrera.--Fallo de los Premios Alonso de Herrera y Antonio José de Cavanilles.-- Propuesta del Instituto de Alimentación y Productividad Animal sobre nombramiento de Vicedirector del mismo.-- Congresos y Reuniones internacionales.-- Creación de la Comisión Conjunta de Investigación Agraria de los Ministerios de Educación y Ciencia y de Agricultura.-- Restauración y adecuación del Jardín Botánico de Madrid.-- III Reunión Nacional de Centros de Investigación Ganadera Tribunales.-- Clausura del XI Curso Internacional de Edafología y Biología Vegetal.-- 7th International Colloquium on Plant Analysis and Fertilizer Problems.-- X Congreso Internacional de Ciencia del Suelo.-- Clausura del IV Congreso de Ciencia y Tecnología de Alimentos.-- 50th Anniversary Meeting of the British Society for Experimental Biología.-- XXIX Symposium on Symbiosis, Society for Experimental Biología.-- IV Reunión de la Sociedad Español de Microscopía Electrónica.-- Subvención de la Fundación Barrie de la Maza a la Misión Biológica de Galicia.-- Conferencia.-- Los universitarios y la defensa de la naturaleza.-- Seminario, sobre Tipos diferentes de costras calizas y su distribución regional.-- BibliografíaPeer reviewed2019-08.- CopyBook.- Libnova.- Biblioteca ICA

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019