41 research outputs found
Efecto de la restricción de agua edáfica en el potencial de agua y acidez diurna y nocturna de Ferocactus histrix y F. pilosus
Las plantas de la familia Cactaceae tienen características morfológicas y fisiológicas, como tallos suculentos, espinas, que les permiten reducir la transpiración y son auxiliares en la economía de agua, y el metabolismo ácido del tipo de las Crasuláceas (MAC), que les han permitido adaptarse a ambientes áridos. Ferocactus histrix es una cactácea globosa y F. pilosus tiene tallo columnar, ambas especies están en la norma NOM-059-SEMARNAT 2010, en la categoría de riesgo “Sujetas a protección especial”. Su fisiología se conoce parcialmente. El objetivo del estudio fue evaluar el efecto del riego y su restricción en el potencial de agua (ΨA) del parénquima y clorénquima y en los cambios de su acidez diurna y nocturna de plantas de Ferocactus pilosus y F. histrix. La hipótesis fue que la planta regula positivamente el ΨA de sus tejidos y mantiene los patrones diurnos y nocturnos de acidez, típicos MAC independientemente de la suspensión de riego. Plantas, de cada especie, se mantuvieron con riego semanal o sin él por un año. El estudio se realizó con un diseño experimental completamente al azar. La unidad experimental fue una planta y cuatro unidades se evaluaron cada 4 h por 24 h, a los 3, 6 y 12 meses. El ΨA se midió en parénquima y clorénquima. La acidez de los tejidos se cuantificó por valoración con NaOH. El ΨA del parénquima fue el más afectado por la ausencia de riego y a los 12 meses alcanzó -3.23 y -9.29 MPa en F. histrix y F. pilosus; el contenido nocturno y diurno de ácido málico del clorénquima y parénquima de F. histrix disminuyó (45 y 28% y 33 y 35%); en F. pilosus disminuyó en ambos tejidos (81% en ambas fases y 68.18 y 90.47% en la nocturna). La suspensión de riego por 3, 6 y 12 meses afectó diferente la acumulación de ácido málico en el ciclo de 24 h de los tejidos de Ferocactus, y disminuyó la producción de ácido málico conforme el aumentó el tiempo sin riego. Ambas especies toleraron 12 en esta condición y reactivaron su crecimiento con el riego posterior
Velvet Bean (Mucuna pruriens var. utilis) a Cover Crop as Bioherbicide to Preserve the Environmental Services of Soil
Velvet Bean (Mucuna pruriens var. utilis) a Cover Crop as Bioherbicide to Preserve the Environmental Services of Soil
CARACTERIZACIÓN ISOENZIMÁTICA DE CULTIVARES DE NOPAL (Opuntia spp.)/Isoenzyme characterization of nopal cultivars (Opuntia spp.)
En nopal (Opuntia spp.) como en muchos géneros, los problemas de clasicación taxonómica son frecuentes,
esto complica la identicación correcta de cultivares. Este estudio se realizó con la nalidad de detectar
polimorsmo en nueve cultivares de nopal de las especies O. amyclaea Ten. (O. albicarpa), O. megacantha, O. crassa
y O. cus-indica (L.) Mill., ubicados en la reserva de germoplasma de la Unidad Regional Universitaria de Zonas Áridas
de la Universidad Autónoma Chapingo. La proteína soluble de las raíces se separó por electroforesis para evaluar la
presencia de nueve sistemas enzimáticos. De estos, fosfoglucomutasa (PGM), 6-fosfogluconato deshidrogenasa (6-
PGD), glutamato oxaloacetato transaminasa (GOT) y malato deshidrogenasa (MDH) expresaron reacción suciente
para una identicación de bandas de actividad enzimática. Las enzimas málicas (ME) y aconitasa (ACO) no presentaron
polimorsmo, por tanto no se recomiendan para la clasicación de cultivares de nopal. En contraste, PGM, 6-PGD,
GOT y MDH presentaron diferencias o polimorsmo indeterminado en su patrón de bandeo, por lo que se consideran
relevantes para la identicación taxonómica y evaluación de la variabilidad genética de nopal
Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants
© The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups
Repositioning of the global epicentre of non-optimal cholesterol
High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe
Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants
Background
Hypertension can be detected at the primary health-care level and low-cost treatments can effectively control hypertension. We aimed to measure the prevalence of hypertension and progress in its detection, treatment, and control from 1990 to 2019 for 200 countries and territories.
Methods
We used data from 1990 to 2019 on people aged 30–79 years from population-representative studies with measurement of blood pressure and data on blood pressure treatment. We defined hypertension as having systolic blood pressure 140 mm Hg or greater, diastolic blood pressure 90 mm Hg or greater, or taking medication for hypertension. We applied a Bayesian hierarchical model to estimate the prevalence of hypertension and the proportion of people with hypertension who had a previous diagnosis (detection), who were taking medication for hypertension (treatment), and whose hypertension was controlled to below 140/90 mm Hg (control). The model allowed for trends over time to be non-linear and to vary by age.
Findings
The number of people aged 30–79 years with hypertension doubled from 1990 to 2019, from 331 (95% credible interval 306–359) million women and 317 (292–344) million men in 1990 to 626 (584–668) million women and 652 (604–698) million men in 2019, despite stable global age-standardised prevalence. In 2019, age-standardised hypertension prevalence was lowest in Canada and Peru for both men and women; in Taiwan, South Korea, Japan, and some countries in western Europe including Switzerland, Spain, and the UK for women; and in several low-income and middle-income countries such as Eritrea, Bangladesh, Ethiopia, and Solomon Islands for men. Hypertension prevalence surpassed 50% for women in two countries and men in nine countries, in central and eastern Europe, central Asia, Oceania, and Latin America. Globally, 59% (55–62) of women and 49% (46–52) of men with hypertension reported a previous diagnosis of hypertension in 2019, and 47% (43–51) of women and 38% (35–41) of men were treated. Control rates among people with hypertension in 2019 were 23% (20–27) for women and 18% (16–21) for men. In 2019, treatment and control rates were highest in South Korea, Canada, and Iceland (treatment >70%; control >50%), followed by the USA, Costa Rica, Germany, Portugal, and Taiwan. Treatment rates were less than 25% for women and less than 20% for men in Nepal, Indonesia, and some countries in sub-Saharan Africa and Oceania. Control rates were below 10% for women and men in these countries and for men in some countries in north Africa, central and south Asia, and eastern Europe. Treatment and control rates have improved in most countries since 1990, but we found little change in most countries in sub-Saharan Africa and Oceania. Improvements were largest in high-income countries, central Europe, and some upper-middle-income and recently high-income countries including Costa Rica, Taiwan, Kazakhstan, South Africa, Brazil, Chile, Turkey, and Iran.
Interpretation
Improvements in the detection, treatment, and control of hypertension have varied substantially across countries, with some middle-income countries now outperforming most high-income nations. The dual approach of reducing hypertension prevalence through primary prevention and enhancing its treatment and control is achievable not only in high-income countries but also in low-income and middle-income settings
Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)
From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions
Symptoms and sensitivity to chilling injury of pitahaya (Hylocereus undatus (HAW.) britton &c Rose) fruits during postharvest
Dragon fruit or pitahaya (Hylocereus undatus (Haw.) Britton & Rose) is an exquisite and exotic fruit with attractive aroma and flavor, and a characteristic red-skinned color. Its production and supply for regional and foreign markets is limited to its storage life. The objective of this study was to evaluate physiological alterations and sensitivity to chilling injuries during postharvest of pitahaya. Fruits harvested at the Tehuacán Valley, Puebla, México, were stored at three postharvest temperatures: 3, 7, and 11±1 °C, for 7, 14, and 21 d and under these conditions plus a 4 d period at 22±1 °C. Evaluated fruits were then contrasted with fresh fruit (control 1), and non-cold stored fruits maintained 4 d at 22 °C (control 2). Variables were epicarp color, fruit firmness, total soluble solids (TSS), titratable acidity, and vitamin C content in the mesocarp; and a maturity index was calculated. The experimental design was completely randomized, with 10 repetitions, where one fruit was the experimental unit. Results were analyzed using ANOVA and treatment means were compared with the Tukey test. In order to recognize symptoms of chilling injury a multivariate data analysis of Principal-Component (PC) was also carried out. Control 1 fruits was red, with relatively low-lightness and bright suitably index of L* 38, hue angle 38 and chroma 39. The color of control 2 fruits significantly changed compared to control 1 (L* 46, hue angle 6, and chroma, 53). Fruit on cold storage maintained color, firmness (5 N), TSS (9.7 °Brix), acidity (0.37 g malic acid g-1), maturity index (42 °Brix g malic acid g-1) and vitamin C content (0.78 mg 100 g-1) partially stable. Changes depending on temperature and time of storage did not follow identifiable trends. Chilling injury in pitahaya fruits does not occur progressively, and is higher under cold and room storage temperature. PC analysis indicated that 7 d of storage partially maintained fruits quality, regardless of the extra 4 d time at room temperature; thus, implying that postharvest handling of pitahaya fruits may extend its shelf life several days.La pitahaya (Hylocereus undatus (Haw.) Britton & Rose) es una fruta exquisita y exótica con aroma y sabor atractivos, y color de piel rojo característico. Su producción y suministro para los mercados regionales y extranjeros son limitados por su vida de anaquel. El objetivo de este estudio fue evaluar las alteraciones fisiológicas y la sensibilidad al daño por frío en la pitahaya durante la postcosecha. Frutos cosechados en el Valle de Tehuacán, Puebla, México, se almacenaron a tres temperaturas postcosecha: 3, 7 y 11±1 °C, por 7, 14 y 21 d, y en estas condiciones más un periodo de 4 d a 22±1 °C.Los frutos evaluados se compararon con frutos frescos (testigo 1), y los frutos almacenados sin frío se conservaron 4 d a 22 °C (testigo 2). Las variables fueron color del epicarpio, firmeza del fruto, sólidos solubles totales (SST), acidez titulable y contenido de vitamina C en el mesocarpio; y se calculó el índice de madurez. El diseño experimental fue completamente aleatorio, con 10 repeticiones, y un fruto fue la unidad experimental. Los resultados se analizaron con ANDEVA y las medias de los tratamientos se compararon con la prueba de Tukey. Para reconocer los síntomas del daño por frío se realizó un análisis multivariado de componentes principales (CP). Los frutos del testigo 1 fueron rojos, con luminosidad relativamente baja y un índice de brillantez adecuada de L* 38, ángulo de tonalidad 38 y croma 39. El color de los frutos del testigo 2 cambió significativamente en relación al testigo 1 (L* 46, ángulo de tonalidad 6 y croma 53). Los frutos en almacenamiento frío conservaron color, firmeza (5 N), SST (9.7 o Brix), acidez (0.37 g ácido málico g-1), índice de madurez (42 o Brix g ácido málico g-1) y contenido de vitamina C (0.78 mg 100 g-1) parcialmente estables. Los cambios que dependieron de la temperatura y el tiempo de almacenamiento no siguieron tendencias identificables. El daño por frío en frutos de pitahaya no ocurre progresivamente, y es mayor con almacenamiento frío y temperatura ambiente. El análisis CP indicó que 7 d de almacenamiento mantienen la calidad de los frutos parcialmente, independiente de los 4 d extra a temperatura ambiente; esto implica que el manejo postcosecha de los frutos de pitahaya puede extender la vida de anaquel por varios días