56 research outputs found
Evaluación de los mecanismos de acción biológica de Trichoderma
Este trabajo describe los mecanismos de control biológico que se expresan en Trichoderma, además mediante la aplicación de los marcadores ITS y Tef1α se realiza la caracterización taxonómica de 10 cepas de Trichoderma aisladas en la región hortícola de Tenango y a través de pruebas de confrontación dual se determina su capacidad antagónica contra diferentes patógenos fúngicos de la papaEl presente trabajo demostró que en la Peñuela localidad del Municipio de Zinacantepec, Estado de México, en los últimos años, el cultivo de la papa (Solanum tuberosum) se ha visto afectado por la presencia de agentes patógenos principalmente hongos como P. infestans, F. avenaceum, Alternaria sp y Rhizoctonia sp. causantes de enfermedades que degradan la calidad del tubérculo tales como Tizón temprano, Damping off, Tizón tardío y Rizoctoniasis respectivamente. La caracterización morfológica ayudó a ubicar taxonómicamente a nivel de género a los cuatro hongos patógenos. Pero, para el caso de Fusarium fue necesaria la caracterización molecular lo cual permitió comprobar que F. avenaceum es una especie patógena para el cultivo de papa en esta zona de estudio. Ya que esta especie es reportada como patógena de cultivos de gramíneas como la avena, sin embargo, se encontró que rompió las barreras agroecológicas y ahora daña a este tubérculo. También con herramientas moleculares utilizando los marcadores ITS y Tef1α se ubicaron taxonómicamente a diez cepas nativas de Trichoderma; 6 cepas como T. asperellum (TL2, TL4, TX7, TX8, TT6,TF8) y 4 cepas como Hipocrea lixii (TL5,TL6,TF10 TJ6), el teleomorfo de T. harzianum. Como estrategia ecológica y con la finalidad de conocer el potencial de biocontrol de estas cepas de Trichoderma se realizaron pruebas de antagonismo mediante cultivos duales enfrentando a los patógenos que afectan el cultivo de papa Alternaria sp., Rhizoctonia sp. P. infestans y Fusarium avenaceum. Los resultados registraron diferencias significativas en el porcentaje de biocontrol de las cepas de Trichoderma sobre los patógenos. Donde la cepa TX8 (T. asperellum) registró los porcentajes más altos de inhibición sobre, F. avenaceum, Alternaria sp y P. infestas con 100%, 100% y 98.12%, respectivamente Para el caso de Rhizoctonia sp., H. lixii presentó los porcentajes de inhibición más altos 65% y 51% para las cepas TF10 y TL5 respectivamente. La cepa TL4 (T. asperellum) hacia los cuatro patógenos mostró el valor más bajo de antagonismo. La respuesta antagónica de la cepas nativas de Trichoderma desencadeno mecanismos de acción biológica, donde el más frecuente fue la competencia hacia Alternaria sp. y Rhizoctonia sp. y P. infestans mientras que para F. avenaceum la antibiosis fue el mecanismo que favoreció el antagonismo. Sin embargo, también el micoparasitismo en algunos casos se presentó junto con la competencia hacia P. infestans y Rhizoctonia sp.CONACyT UAEMEX COMECy
Impact of Extensive Grazing on Supporting and Regulating Ecosystem Services of Mountain Soils
Livestock grazing impacts
the ecosystems of high
mountains and adjacent
low-elevation regions as a
result of the physical,
chemical, and hydrological
connectivity of soil. In
particular, grazing may
alter the ecosystem
services provided by soil, such as carbon and organic matter
accumulation, carbon storage, and water infiltration. The
present study evaluated the relative contents of soil organic
matter (SOM) and soil organic carbon (SOC) on soil in a humaninduced
grassland and an frequently grazed Abies religiosa
(Kunth) Schltdl. & Cham. forest in Nevado de Toluca, Mexico. It
assessed carbon stocks in 2 different soil layers (0–5 cm and
5–25 cm), as well as soil compaction and water infiltration in
both land uses. Results showed slightly lower SOM (21.7%) and
SOC (12.6%) in soils on which livestock were grazed than in
forest soils (25.7% for SOM and 14.65%, for SOC) at both
depths and a greater bulk density of livestock soils (0.86 g
cm3
) than of forest soils (0.73 g cm3
), particularly in the 0–5-
cm layer (0.88 g cm3
) of livestock soils. More than 40 years of
livestock grazing has clearly impacted the capacity of soils to
accumulate organic matter and organic carbon. However,
carbon stocks and water infiltration were not significantly
affected, as low carbon accumulation was compensated by
changes in soil bulk density. These results indicate that
extensive livestock ranching and resource conservation are not
necessarily mutually exclusive in the study site. Direct and
indirect mechanisms involved in the provision of the evaluated
regulating services should be further studied, taking into
account the highly variable social and environmental conditions
of Nevado de Toluca. Management policies should also aim to
maintain an equilibrium between livestock rancher needs and
conservation of supporting and regulating ecosystem services
that are highly relevant to the functioning of mountain
ecosystems.Consejo Nacional de Ciencia y Tecnología A.C. a través de proyecto Ciencia Básica 219696. Universidad Autónoma del Estado de Mexico; project 3770/2014/CID
Phenotypic plasticity of growth ring traits in Pinus hartwegii at the ends of its elevational gradient
IntroductionPhenotypic plasticity (PP) could be an important short-term mechanism to modify physiological and morphological traits in response to climate change and global warming, particularly for high-mountain tree species. The objective was to evaluate PP response of growth ring traits to temperature and precipitation in Pinus hartwegii Lindl. populations located at the ends of its elevational gradient on two volcanic mountains in central Mexico (La Malinche and Nevado de Toluca).MethodsIncrement cores collected from 274 P. hartwegii trees were used to estimate their PP through reaction norms (RN), which relate the ring width and density traits with climate variables (temperature and precipitation). We estimated the trees’ sensitivity (significant RN) to climatic variables, as well as the relative proportion of RN with positive and negative slope. We also estimated the relationship between the PP of ring width and density traits using correlation and Principal Component (PC) analyses.ResultsOver 70% of all trees showed significant RN to growing season and winter temperatures for at least one growth ring trait, with a similar proportion of significant RN at both ends of the gradient on both mountains. Ring width traits had mostly negative RN, while ring density traits tended to have positive RN. Frequency of negative RN decreased from lower to higher elevation for most traits. Average PP was higher at the lower end of the gradient, especially on LM, both for ring width and ring density traits, although high intrapopulation variation in PP was found on both mountains.DiscussionResults indicate that P. hartwegii presents spatially differentiated plastic responses in width and density components of radial growth. PP was particularly strong at the lower elevation, which has higher temperature and water stress conditions, putting these populations at risk from the continuing global warming driven by climate change
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele
TRY plant trait database – enhanced coverage and open access
Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes
Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Evaluation of the Maguey products portfolio for rural cooperatives in Mexico
This paper shows a products portfolio from a cooperative society of Maguey pulquero producers analysis, as an instrument of strategic planning and investment. The commercial diagnostic phases, market research and portfolio products design were considered. A productive chain analysis was made, considering their productive links, post-harvest management and commercialization. A market research was made in two important market centers in business influential regions, where we identified the knowledge and frequency of consumption of the maguey products. The Boston Consulting Matrix was used in order to integrate the portfolio’s products and the Ansoff Matrix to determine the product’s positioning. Finally, an investment and economic viability analysis of the portfolio products was made. Six products were gotten, being the pulque and the agave syrup the investment priority products given the profits they generate while the penca, ixtle and paper represent complementary income. The strategies for the pulque and the agave syrup were the market penetration, and the strategies for the rest of the products are the market and product development. The analyzed products were positive to Net Present Value, Investment Return Rate and cost benefit ratio
Estudio de prefactibilidad económica para la implementación del sistema agroindustrial en la cadena productiva de aguacate (Persea americana Mill) en la Región X de Ixtapan de la Sal, Estado de México
Este trabajo se fundamenta en las problemáticas identificadas en los periodos de producción 2005 - 2015 del sistema-producto aguacate, en un contexto regional del DDR X, Ixtapan de la Sal, Estado de MéxicoEl objetivo del presente trabajo fue evaluar la factibilidad económica para la implementación de un sistema agroindustrial en la Región X Ixtapan de la Sal. Con éste fin se diagnóstico el sistema aguacate con una perspectiva orientada a los puntos de creación de valor y su apropiación local en los municipios de Malinalco, Ocuilan y Tenancingo de la Región X Ixtapan de la Sal. El análisis de la cadena productiva de aguacate en los tres municipios de ésta región, se llevó a cabo en el periodo comprendido de 2015 a 2016; el levantamiento de la información fue a través de la aplicación de 82 encuestas a productores, recorridos de campo en huertas de aguacate, reuniones con productores y visitas a los mercados regionales de Tenancingo y Santiago Tianguistenco, Estado de México. Los datos colectados se utilizaron para el análisis de la cadena y de rentabilidad. La Rentabilidad fue determinada utilizando la Matriz de Análisis de Política en su primer renglón.
Se realizó la evaluación financiera de una planta extractora de aguacate, utilizando la herramienta de formulación y evaluación de proyectos. El análisis se determinó en un horizonte de cinco años. Se integró la estrategia comercial, diseño técnico y financiero considerando aportaciones de los socios, subsidio y financiamiento. Finalmente se realizó un análisis de riesgo basado en indicadores VAN, TIR, R B/C, PR, en base a precios de venta del producto. Este análisis reportó baja incertidumbre en contraste con la TREMA de 15%, siendo los indicadores financieros, VAN de 3,979,396; TIR de 25.4% y R B/C 2.26, PR de 2.8 años, por sus parte el análisis de sensibilidad evidenció que el proyecto puede soportar una reducción en el precio de venta de hasta $10.00 pesos mexicanos. En éste contexto no se prevé riesgo y se siguiere su implementaciónCONACy
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