A maize landscape: ethnicity and agro-biodiversity in Chiapas,

Abstract The ecology of maize (Zea mays L.) in Mexico, its center of domestication and diversity, has been researched for several decades. While the broad outlines of diversity and dynamics of native maize populations are known at the farm and national levels, these topics are less well known at the landscape level. Although environmental factors are the principal forces behind the overall diversity of the species in Mexico, recent research suggests that social origin, for instance community of residence or ethno-linguistic group, influences maize population structure at more local levels. A landscape perspective can help to determine whether these social factors operate in a consistent fashion across different environments. Case study data from Chiapas are presented and used to illustrate the role of ethnicity in understanding the ecology of maize diversity in Mexico. The paper contrasts the maize populations and management practices of Spanish speaking mestizos and Mayan language speaking indigenous people across four altitude zones in Chiapas. Environmental differences are primary in determining the overall pattern of maize diversity across the Chiapan landscape, but social origin has a significant effect on maize populations in all environments.

Dispersal of transgenes through maize seed systems in Mexico.

ObjectivesCurrent models of transgene dispersal focus on gene flow via pollen while neglecting seed, a vital vehicle for gene flow in centers of crop origin and diversity. We analyze the dispersal of maize transgenes via seeds in Mexico, the crop's cradle.MethodsWe use immunoassays (ELISA) to screen for the activity of recombinant proteins in a nationwide sample of farmer seed stocks. We estimate critical parameters of seed population dynamics using household survey data and combine these estimates with analytical results to examine presumed sources and mechanisms of dispersal.ResultsRecombinant proteins Cry1Ab/Ac and CP4/EPSPS were found in 3.1% and 1.8% of samples, respectively. They are most abundant in southeast Mexico but also present in the west-central region. Diffusion of seed and grain imported from the United States might explain the frequency and distribution of transgenes in west-central Mexico but not in the southeast.ConclusionsUnderstanding the potential for transgene survival and dispersal should help design methods to regulate the diffusion of germplasm into local seed stocks. Further research is needed on the interactions between formal and informal seed systems and grain markets in centers of crop origin and diversification

Long-term prognosis for 1-year relapse-free survivors of CD34 cell-selected allogeneic hematopoietic stem cell transplantation : a landmark analysis

Altres ajuts: This research was supported in part by National Institutes of Health award number P01 CA23766 and NIH/NCI Cancer Center Support Grant P30 CA008748. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.CD34 selection significantly improves GVHD-free survival in allogeneic hematopoietic cell transplantation (allo-HSCT). Specific information regarding long-term prognosis and risk factors for late mortality after CD34-selected allo-HSCT is lacking, however. We conducted a single-center landmark analysis in 276 patients alive without relapse 1 year after CD34-selected allo-HSCT for AML (n=164), ALL (n=33), or MDS (n=79). At 5 years' follow-up after the 1-year landmark (range 0.03-13 years), estimated RFS was 73% and OS 76%. The 5-year cumulative incidence of relapse and NRM were 11% and 16%, respectively. In multivariate analysis, HCT-CI score ≥ 3 correlated with marginally worse RFS (HR 1.78, 95% CI 0.97-3.28, p=0.06) and significantly worse OS (HR 2.53, 95% CI 1.26-5.08, p=0.004). Despite only 24% of patients with acute GVHD within 1 year, this also significantly correlated with worse RFS and OS, with increasing grades of acute GVHD associating with increasingly poorer survival on multivariate analysis (p<0.0001). Of 63 deaths after the landmark, GVHD accounted for 27% of deaths and was the most common cause of late mortality, followed by relapse and infection. While prognosis is excellent for patients alive without relapse 1 year after CD34-selected allo-HSCT, risks of late relapse and NRM persist, particularly due to GVHD

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Complement lectin pathway activation is associated with COVID-19 disease severity, independent of MBL2 genotype subgroups

IntroductionWhile complement is a contributor to disease severity in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, all three complement pathways might be activated by the virus. Lectin pathway activation occurs through different pattern recognition molecules, including mannan binding lectin (MBL), a protein shown to interact with SARS-CoV-2 proteins. However, the exact role of lectin pathway activation and its key pattern recognition molecule MBL in COVID-19 is still not fully understood.MethodsWe therefore investigated activation of the lectin pathway in two independent cohorts of SARS-CoV-2 infected patients, while also analysing MBL protein levels and potential effects of the six major single nucleotide polymorphisms (SNPs) found in the MBL2 gene on COVID-19 severity and outcome.ResultsWe show that the lectin pathway is activated in acute COVID-19, indicated by the correlation between complement activation product levels of the MASP-1/C1-INH complex (p=0.0011) and C4d (p&lt;0.0001) and COVID-19 severity. Despite this, genetic variations in MBL2 are not associated with susceptibility to SARS-CoV-2 infection or disease outcomes such as mortality and the development of Long COVID.ConclusionIn conclusion, activation of the MBL-LP only plays a minor role in COVID-19 pathogenesis, since no clinically meaningful, consistent associations with disease outcomes were noted

Áreas voluntarias de conservación y la extracción de leña en núcleos agrarios de Oaxaca

The main fuel in rural areas of various Mexican States is firewood. The aim of this research was to analyze the effect of the certification of Areas Voluntarily Destined for Conservation (AVDC) on firewood extraction from Common Use Areas (CUA) in three agrarian centers of Oaxaca. Semi-structured open interviews and surveys were randomly conducted with ejidatarios and community leaders of San Pedro Huamelula, Unión Zapata and San Marcos Arteaga in Oaxaca, as well as with the regional directors of CONANP. Systematic samplings of the woody species in the AVDC and CUA of the three sites were also carried out, and their relative importance value (RIV) was estimated. The number of species used for firewood was between 14 and 26, corresponding to 15% of the species recorded in the samplings, with gatherers preferring those of secondary vegetation. Although access and use of plant resources is limited in the AVDC, which reduces the area from which firewood is extracted, it did not mean over-exploiting CUA resources.El combustible principal en poblaciones rurales de diversas entidades de México es la leña. El objetivo del trabajo fue analizar el efecto de la certificación de Áreas Destinadas Voluntariamente para la Conservación (ADVC) en la extracción de leña de las Áreas de Uso Común (ADUC) en tres núcleos agrarios de Oaxaca. Se realizaron en trevistas abiertas semiestructuradas y encuestas a ejidatarios y líderes comunitarios de manera aleatoria de San Pedro Huamelula, Unión Zapata y San Marcos Arteaga de Oaxaca, así como a los directores regionales de la CONANP. También se realizaron muéstreos sistemáticos de las especies leñosas en las ADVC y ADUC de los tres sitios, y se estimó su valor de importancia relativa (VIR). El número de especies utilizadas para leña estuvo entre 14 y 26, lo que correspondió al 15% de las especies registradas en los muéstreos; prefiriendo las de vegetación secundaria. Aunque en las ADVC se limita el acceso y uso de los recursos vegetales, lo que reduce la superficie de donde se extrae la leña, no significó sobre explotar los recursos de las ADUC

Seed Exchange Networks of Native Maize, Beans, and Squash in San Juan Ixtenco and San Luis Huamantla, Tlaxcala, Mexico

Seed exchange networks among farmers favor circulation of crop varieties and have been discussed as an effective means of crop diversity conservation. This study aims to document the processes and structure of seed exchange networks of native maize, beans, and squash among farmers and other participating sectors (local market or seed banks), analyzing their influence on agrobiodiversity conservation in the municipalities of Ixtenco and Huamantla, in the Mexican state of Tlaxcala. Through interviews, questionnaires, and social network analysis, nodal farmers were identified. In the maize network, five nodal farmers were detected, the blanco maize being the most commonly exchanged seed. In the bean network, three nodal farmers were identified, with amarillo beans as the most exchanged seed. In the squash network, no nodal farmer was identified. For maize and beans, the greater the number of exchanges, the greater the varieties exchanged. The local market of Huamantla and the Vicente Guerrero seed bank are relevant seed sources. The nodal farmers propitiate circulation of a large number of seed varieties in the exchange networks and contribute to maintenance and conservation of agrobiodiversity

Herbicidas en la milpa: Estrategias de aplicación y su impacto sobre el consumo de arvenses

ABSTRACT Many edible weeds growing spontaneously in agricultural areas form part of peasant diets. Some studies indicate that long-term herbicide use diminishes edible weed availability, and presumably, consumption. The research presented here sought to understand the application strategy between herbicide use and the impact on edible weed consumption in the municipality of Amatenango del Valle, Chiapas. Open interviews and plot visits were performed to explore herbicide and edible weed use. Forty farm households were surveyed regarding knowledge and consumption of edible weeds. All of those surveyed apply herbicide and have done so for an average 24 (± 11) years. However they alternate between herbicide application and manual control with hoes and machetes, apply herbicides selectively, and maintain herbicide-free refuges. These practices seem to permit the persistence of edible weeds. They also obtain weeds from home gardens, irrigated fields, and markets. The interviewees continue to consume a variety of weeds, but perceive that their consumption of Amaranthus hybridus, Galinsoga quadriradiata, Brassica rapa, Crotalaria longirostrata and Physalis philadelphica has diminished over the last 10 years (p 0.05). Despite the incipient industrialization of their diet and technological changes in agricultural production, edible weeds maintain their importance in the gastronomy of Amatenango del Valle.RESUMEN Las arvenses son plantas que crecen de forma espontánea en áreas agrícolas, y algunas forman parte de la alimentación campesina. Los estudios indican que el uso prolongado de herbicidas disminuye la disponibilidad de arvenses y reduce su consumo. El objetivo fue conocer las estrategias de aplicación de los herbicidas y cómo afectan el consumo de arvenses en el municipio de Amatenango del Valle, Chiapas. Se realizaron entrevistas abiertas y se visitaron parcelas para conocer el uso de herbicidas y la disponibilidad de arvenses para consumo. Se aplicaron cuestionarios a 40 hogares para documentar el conocimiento de las arvenses comestibles, su consumo actual y el de hace 10 años. Todos los agricultores usan herbicidas, en promedio tienen 24 (±11) años aplicándolo. Los entrevistados alternan la aplicación de herbicida con azadón y machete, el herbicida lo aplican de forma selectiva y mantienen zonas de refugio. Estas prácticas contribuyen a la persistencia de las arvenses; los solares, la milpa de riego y la compra son sitios alternos de obtención de arvenses. Los entrevistados consumen arvenses pero perciben que el consumo de Amaranthus hybridus, Galinsoga quadriradiata, Brassica rapa, Crotalaria longirostrata y Physalis philadelphica ha disminuido en los últimos diez años (p 0.05). A pesar de los cambios en su dieta por influencia de alimentos industrializados y cambios tecnológicos en el manejo de la milpa, las arvenses continúan siendo un elemento arraigado en la gastronomía de Amatenango del Valle