Estimation of carbon stocks under different soil uses in the central highlands of Mexico

La pérdida de los almacenes de carbono orgánico en el suelo y su expulsión a la atmósfera por efecto de las actividades antrópicas debe entenderse como un problema que trasciende del contexto ambiental al social y económico, siendo la degradación de los suelos una de sus múltiples manifestaciones. Si bien, la acumulación del carbono en el suelo depende de manera natural de la interacción de una serie de factores bióticos y abióticos, las prácticas de manejo, con frecuencia implican el deterioro de sus propiedades físicas, químicas y biológicas, y con ello el incremento de los niveles de mineralización y reducción de este almacén. Este trabajo se realizó en el municipio de San José del Rincón, Estado de México en suelos volcánicos bajo diferentes condiciones de uso y tiempos de manejo, de los cuales se obtuvieron muestras en 11 sitios de las que se realizaron análisis físicos y químicos y se obtuvo el almacén de carbono orgánico del suelo a una profundidad de 20 cm. Los resultados obtenidos indicaron que para los suelos bajo uso agrícola y pastoreo hubo incrementos significativos en la densidad aparente, mayor acidez y disminución de la concentración de carbono, con respecto a los suelos forestales. Los almacenes de carbono orgánico para los usos de suelo forestal, agrícola y pecuario a 20 cm de profundidad fueron de 131, 53 y 63 Mg C ha-1 respectivamente, estos resultados sugieren que el tiempo e intensidad de manejo son determinantes en la pérdida de los almacenes del carbono orgánico del suelo, así como en la alteración de algunas de sus propiedades físicas y químicas.The loss of organic carbon stocks from the soil and their expulsion into the atmosphere due to the effect of anthropogenic activities must be understood as a problem that goes beyond the environmental to the social and economic context, with the soil degradation being just one of its many impacts. While the accumulation of carbon in the soil depends naturally on the interaction among a series of biotic and abiotic factors, management practices often cause the deterioration of its physical, chemical and biological properties, and, thus, increase the levels of mineralization and a reduction in carbon stocks. This study was undertaken in the municipality of San José del Rincón, State of Mexico, in volcanic soils under different conditions of land use and handling time periods. Samples were obtained at 11 plots, on which physical and chemical analyses were undertaken, obtaining soil organic carbon stocks at 20 cm top soil. The results indicated that, for the soils used for agriculture and induced pasture, there were significant increases in the bulk density, greater acidity and a decrease in carbon concentration compared to forest soils. The organic carbon stocks taken from soils used in forestry, agriculture and induced pasture at a depth of 20 cm were 131, 53 and 63 Mg C ha-1 respectively, results which suggest that the timing and intensity of management are determinants in the loss of soil organic carbon stocks from the soil, as well as the alteration of some of their physical and chemical properties.Proyecto PROMEP DSA/103.5/15/718

Estudios de Caso sobre Ciencias Agropecuarias y Rurales en el siglo XXI.

Libro científico sobre estudios de casos en el medio agropecuario y ruralCon el advenimiento del siglo XXI y el avance de los procesos de globalización, el medio rural presenta diversos cambios económicos, sociales, políticos y culturales. Lo anterior significa que el campo es un objeto de estudio altamente dinámico, complejo e inasible. las ciencias agropecuarias y rurales, en la actualidad, requieren de un abordaje sistémico e interdisciplinario que den cuenta de la heterogeneidad de situaciones y contextos que enfrenta el campo mexicano. La presente obra agrupa 18 estudios de caso, que capturan algunas fotografías de las diversas problemáticas de la ruralidad mexicana, con lo cual se pretende dar cuenta tanto de los objetivos de estudio como de la perspectiva teórico metodológico desde que estos son abordados. lo anterior tiene que ver con el hecho de que las ciencias agropecuarias y rurales manifiestan un alto grado de observación empírica, motivo por el que los estudios de caso se convierten en la perspectiva metodológica idónea que permite ir y venir de la realidad a la teoría y viceversa para la construcción de objetos de estudio. En este volumen se aborda una gran diversidad de casos, que sintetizan la heterogeneidad de enfoques y perspectivas mediante las cuales los fenómenos agropecuarios y rurales han sido abordados en el Instituto de Ciencias Agropecuarias y Rurales de la Universidad Autónoma del Estado de México, en los últimos 30 años

Familial hypercholesterolaemia in children and adolescents from 48 countries: a cross-sectional study

Background: Approximately 450 000 children are born with familial hypercholesterolaemia worldwide every year, yet only 2·1% of adults with familial hypercholesterolaemia were diagnosed before age 18 years via current diagnostic approaches, which are derived from observations in adults. We aimed to characterise children and adolescents with heterozygous familial hypercholesterolaemia (HeFH) and understand current approaches to the identification and management of familial hypercholesterolaemia to inform future public health strategies. Methods: For this cross-sectional study, we assessed children and adolescents younger than 18 years with a clinical or genetic diagnosis of HeFH at the time of entry into the Familial Hypercholesterolaemia Studies Collaboration (FHSC) registry between Oct 1, 2015, and Jan 31, 2021. Data in the registry were collected from 55 regional or national registries in 48 countries. Diagnoses relying on self-reported history of familial hypercholesterolaemia and suspected secondary hypercholesterolaemia were excluded from the registry; people with untreated LDL cholesterol (LDL-C) of at least 13·0 mmol/L were excluded from this study. Data were assessed overall and by WHO region, World Bank country income status, age, diagnostic criteria, and index-case status. The main outcome of this study was to assess current identification and management of children and adolescents with familial hypercholesterolaemia. Findings: Of 63 093 individuals in the FHSC registry, 11 848 (18·8%) were children or adolescents younger than 18 years with HeFH and were included in this study; 5756 (50·2%) of 11 476 included individuals were female and 5720 (49·8%) were male. Sex data were missing for 372 (3·1%) of 11 848 individuals. Median age at registry entry was 9·6 years (IQR 5·8-13·2). 10 099 (89·9%) of 11 235 included individuals had a final genetically confirmed diagnosis of familial hypercholesterolaemia and 1136 (10·1%) had a clinical diagnosis. Genetically confirmed diagnosis data or clinical diagnosis data were missing for 613 (5·2%) of 11 848 individuals. Genetic diagnosis was more common in children and adolescents from high-income countries (9427 [92·4%] of 10 202) than in children and adolescents from non-high-income countries (199 [48·0%] of 415). 3414 (31·6%) of 10 804 children or adolescents were index cases. Familial-hypercholesterolaemia-related physical signs, cardiovascular risk factors, and cardiovascular disease were uncommon, but were more common in non-high-income countries. 7557 (72·4%) of 10 428 included children or adolescents were not taking lipid-lowering medication (LLM) and had a median LDL-C of 5·00 mmol/L (IQR 4·05-6·08). Compared with genetic diagnosis, the use of unadapted clinical criteria intended for use in adults and reliant on more extreme phenotypes could result in 50-75% of children and adolescents with familial hypercholesterolaemia not being identified. Interpretation: Clinical characteristics observed in adults with familial hypercholesterolaemia are uncommon in children and adolescents with familial hypercholesterolaemia, hence detection in this age group relies on measurement of LDL-C and genetic confirmation. Where genetic testing is unavailable, increased availability and use of LDL-C measurements in the first few years of life could help reduce the current gap between prevalence and detection, enabling increased use of combination LLM to reach recommended LDL-C targets early in life