RESUMEN
Plantago lanceolata L. (plantain) increases herbage dry matter (DM) production and quality during warm and dry conditions due to its deep roots and drought tolerance and reduces nitrogen losses in grazing systems compared to traditional pastures. However, plantain density usually declines after the third growing season, mainly due to defoliation management. The effects of defoliation frequency and intensity on water-soluble carbohydrate (WSC) reserves and below-ground plant responses need further research to optimize grazing strategies for improved productivity and sustainability of grazing systems. Our study investigated the effects of defoliation frequencies (15, 25, and 35 cm of extended leaf length, ELL) and intensities (5 and 8 cm of residual heights) on morphological traits and WSC concentrations in plantain biomass under controlled environmental conditions. Defoliation frequency significantly influenced morphological and chemical characteristics and biomass distribution more than residual height. Less frequent defoliations promoted above-ground herbage DM production, reproductive stems, and root biomass. Root architecture showed adaptations in response to defoliation frequency, optimizing resource acquisition efficiency. Frequent defoliation reduced high molecular weight WSC concentrations in leaves, affecting regrowth capacity and DM mass. A defoliation frequency of 25 cm ELL (~15 days) balances herbage production and root development, promoting long-term pasture sustainability.
RESUMEN
Traditional pastures in temperate regions face limitations such as reduced growth and nutritional quality during the summer season. Plantain (P. lanceolata L.) offers advantages like increased yield and decreased nitrogen losses from grazing ruminants. Effective grazing management is essential for pasture health, and defoliation frequency and intensity play a pivotal role. This study aimed to evaluate plantain's regrowth, yield, and morpho-physiological and chemical responses under different defoliation frequencies and intensities, with the goal of enhancing its management in pastures. The study was conducted in pots within a controlled-environment growth chamber, examining the impact of three defoliation frequencies (based on extended leaf length: 15, 25 and 35 cm) and two defoliation intensities (5 and 8 cm of residual heights) with four replicates (24 pots as experimental units). The variables of interest were morphological characteristics, dry matter (DM) accumulation, herbage chemical composition, growth rate traits, and photosynthetic parameters. Defoliation frequency affected plantain's growth and nutritional composition. More frequent cuts (15 cm) resulted in lower DM yield per cut and lower stem content, while less frequent cuts (35 cm) produced higher values. Defoliation intensity influenced the proportion of leaves and stems in the total DM, with 5 cm cuts favoring leaves. Nutrient content was also affected by defoliation frequency, with less frequent cuts (35 cm) showing lower crude protein concentration and metabolizable energy content but higher neutral detergent fiber and water-soluble carbohydrate concentration. Plantain's growth rate variables were mainly influenced by defoliation frequency, with less frequent cuts promoting faster leaf appearance and growth of new leaves. The basal fluorescence variables and chlorophyll content were affected by cutting frequency, being highest when cut less frequently (35 cm), while no differences were found in the actual quantum efficiency among different defoliation frequencies and intensities. The fraction of light dedicated to non-photochemical quenching was highest when cut less frequently and more intensively. Overall, defoliation at 25 cm of extended leaf length balanced plantain forage quality and regrowth capacity.
Asunto(s)
Hojas de la Planta , Plantago , Plantago/crecimiento & desarrollo , Plantago/fisiología , Plantago/metabolismo , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/anatomía & histología , Hojas de la Planta/metabolismo , Fotosíntesis , Estaciones del AñoRESUMEN
En las últimas décadas, la terapia de plasma rico en plaquetas (PRP) ha despertado mucha atención en el área de la medicina regenerativa, siendo aplicada a diferentes patologías sistémicas y localizadas. El PRP proporciona diversos factores de crecimiento y proteínas que pueden estimular al proceso de regeneración celular, representa un factor importante para su uso clínico generalizado, en diferentes tejidos en donde el suministro de sangre es lento o limitado y apoya la recuperación, cicatrización, activación biológica de células de defensa, estabilización en la regeneración celular y tisular, teniendo uso clínico en casi todas las especialidades médicas. Esta revisión tiene como objetivo presentar las bases teóricas para la potencial aplicación del PRP y sus factores de crecimiento en tratamientos que buscan una terapia regenerativa por bioestimulación de la aplicación autóloga, en patologías para las cuales aún no existe tratamiento específico. Se revisaron artículos de los últimos 10 años en los buscadores y bases de datos Google Scholar, PubMed y Scopus y se seleccionaron aquellos que pueden ayudar a entender la aplicación de PRP en diversos procesos de regeneración, con miras a utilizarse como un tratamiento alternativo y complementario a pacientes con COVID-19. Se encontró abundante literatura experimental y clínica en el uso de PRP autóloga, en diversos procesos de regeneración, inclusive en neumología e infectología, por lo que amerita comprobar su efecto con protocolos establecidos, en patologías respiratorias severas como apoyo biológico autólogo para activar la respuesta biológica innata de tipo celular.
Platelet-rich plasma (PRP) therapy has generated much attention in recent decades in regenerative medicine, being applied to different systemic and localized pathologies. PRP provides various growth factors and proteins that can stimulate the cell regeneration process. It is an important factor for its clinical use in different tissues where blood supply is slow or limited, and supports the recovery, healing, activation of defense cells, cellular stabilization, and tissue regeneration, having clinical use in almost all medical specialties. Articles from the last 10 years in Google Scholar, PubMed and Scopus were reviewed and selected those that can help to understand the application of PRP in various regeneration processes, with a view to use as an alternative and complementary treatment for patients with Covid-19. It was found that there is abundant experimental and clinical literature on the use of autologous PRP in various regeneration processes, including pneumology and infectious diseases. It worth evaluating its effect in severe respiratory diseases as an autologous biological support to activate the innate cellular response.
Asunto(s)
Humanos , Terapéutica , Medicina Regenerativa , Plasma Rico en Plaquetas , Neumología , Enfermedades Transmisibles , Infecciones por CoronavirusRESUMEN
BACKGROUND: Successful vaccination strategies against norovirus will require understanding the burden of disease and relevant genotypes in populations. However, few data are available from cohort studies of adults living in low- and middle-income countries (LMIC). MATERIALS AND METHODS: We conducted a nested case-control study within a Peruvian military cohort to characterize the burden of norovirus infection, predominant genotypes, and associated symptoms from 2004 through 2011. Randomly selected case and control stools were tested for norovirus, bacteria, and parasites. The odds ratio of the association between norovirus infection and diarrhea was estimated using multiple logistic regression and co-infection adjusted attributable fractions were calculated. RESULTS: Of the 3,818 cohort study participants, 624 developed diarrhea. Overall and norovirus-associated diarrhea incidence rates were 42.3 and 6.0 per 100 person-years, respectively. The most prevalent norovirus genogroup was GII (72.5%, 29/40), which was associated with diarrhea (AOR 3.4, 95% CI: 1.3-8.7, P = 0.012). The co-infection adjusted GII attributable fraction was 6.4%. DISCUSSION: Norovirus was a frequent cause of diarrhea in an adult population followed longitudinally in an LMIC setting. Vaccine strategies should consider targeting adults in endemic settings and special populations that could serve as community transmission sources.