By feeding on plant tissue, insect herbivores can change several characteristics of their hosts. These changes have the potential to alter the quality of the plant for other herbivore species, ...potentially altering the structure of the community of species attacking the plant at a later point in time. We tested whether herbivory early in the season changes host plant performance, polyphenol chemistry, and the community structure of sessile herbivores later in the season. We experimentally manipulated densities of early-season moth caterpillars on a set of young oak trees and measured tree growth, reproduction, leaf chemistry, and the abundance and community composition of leafmining and galling species later in the season. The experimental manipulations of early-season herbivores did not affect late-season leaf chemistry or tree performance. Early-season herbivores had a weak negative effect on the abundance of gallers and a positive, tree-dependent effect on the overall diversity of late-season sessile herbivores. The chemical composition of leaves covaried with the species composition of the late-season leafmining and galling community. Both the chemical composition of the host tree and the late-season insect community structure were strongly affected by the growth location of the tree. Our results suggest that plant-mediated indirect effects between herbivores might play a limited role in this system, whereas the underlying variation in plant chemistry is an important factor structuring the associated insect community. Our results emphasize that factors other than prior herbivory can be important determinants of plant chemistry and the community composition of herbivores.
Nanomaterials have found an important place in Analytical Chemistry and, in particular, in Separation Science. Among them, metal‐organic frameworks, magnetic and non‐magnetic nanoparticles, carbon ...nanotubes and graphene, as well as their combinations, are the most important nanomaterials that have been used up to now. Concerning capillary electromigration techniques, these nanomaterials have also been used as both pseudostationary phases in electrokinetic chromatography (EKC) and as stationary phases in microchip capillary electrophoresis (CE) and capillary electrochromatography (CEC), as a result of their interesting and particular properties. This review article pretends to provide a general and critical revision of the most recent applications of nanomaterials in this field (period 2010–2017).
Tropical forest disturbance contributes to global climate change from increased carbon emissions, and causes loss of biodiversity. Thus, identifying its direct causes and underlying drivers are ...necessary for effective land use, climate change control and conservation strategies. We integrated remote sensing forest cover data from 2000 to 2018 with georeferenced national socioeconomic and field‐collected household data to determine underlying drivers behind forest cover transitions (e.g., deforestation, degradation, and recovery) in the Selva Maya (‘Mayan Forest’) of southeast Mexico. Spatial and statistical models (multinomial logistic regression, log‐linear regression, and analysis of variance) and social science methods (household surveys and qualitative comparative analysis) were applied to evaluate and identify socioeconomic, institutional, and environmental drivers intervening at landscape and community scales. Forest cover transitions varied geographically, and associated drivers differed by scale of analysis. Using multiple methods improved the understanding of drivers. Population growth, poverty, and roads are major drivers influencing forest cover transitions (e.g., deforestation, degradation, and recovery) in the landscape. Community scale analysis identified more drivers and offered greater detail of causal relationships. Besides population and poverty, less off‐farm employment, agriculture and cattle production, immigrant population, and private property were related to deforestation and degradation. Indigenous populations, forest dependence, off‐farm employment, and common property were associated with forest conservation. Sustainable rural development should include poverty alleviation through diversification of economic activities and increased off‐farm employment opportunities. Conservation measures should pursue the enhancement of forest value for local subsistence and economic benefits by strengthening community forest management and enterprises.
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Sodium alendronate is a nitrogen-containing bisphosphonate, widely used for osteoporosis treatment. However, due to its several oral administration drawbacks, the transdermal route ...represents an interesting option. The aim of this study was to formulate sodium alendronate in two submicron delivery systems, microemulsions, and solid-in-oil nanosuspensions, both systems possessing permeation enhancing properties. The composition of microemulsions was determined through the construction of pseudo-ternary phase diagrams. Solid-in-oil nanosuspensions were prepared by an emulsification-freeze-drying method, evaluating the effect of sonication time and the type of surfactant. According to the results of drug loading capacity, droplet/particle size, and polydispersity index, two microemulsions and two nanosuspensions were selected to perform the subsequent evaluations. The results showed that microemulsions allowed a faster release of alendronate than nanosuspensions. The permeation capacity of alendronate formulations was assessed through the synthetic membrane Strat M®, as well as through pigskin, finding higher fluxes with microemulsions than with nanosuspensions. In order to elucidate the effect of the formulations on the permeability barrier of the stratum corneum, techniques such as ATR-FTIR and TEWL were used. Finally, measurements of erythema intensity showed that neither of the two nanosystems caused skin irritation after 2 h of contact. The results suggest that alendronate formulated in a microemulsion can be a viable transdermal nanocarrier for osteoporosis treatment.
Pesticides are among the most important contaminants worldwide due to their wide use, persistence, and toxicity. Their presence in soils is not only important from an environmental point of view, but ...also for food safety issues, since such residues can migrate from soils to food. However, soils are extremely complex matrices, which present a challenge to any analytical chemist, since the extraction of a wide range of compounds with diverse physicochemical properties, such as pesticides, at trace levels is not an easy task. In this context, the QuEChERS method (standing for quick, easy, cheap, effective, rugged, and safe) has become one of the most green and sustainable alternatives in this field due to its inherent advantages, such as fast sample preparation, the minimal use of hazardous reagents and solvents, simplicity, and low cost. This review is aimed at providing a critical revision of the most relevant modifications of the QuEChERS method (including the extraction and clean-up steps of the method) for pesticide-residue analysis in soils.
Rosmarinus officinalis L. (Lamiaceae) is an aromatic plant widely popular mainly due to its uses in traditional medicine as an anti‐inflammatory, diuretic and antimicrobial, as well as in the ...prevention and treatment of diseases. These biological activities are mainly related to the presence of phenolic and terpenic compounds. This work reports a chemical profile analysis of extracts from leaves and calli of rosemary obtained by both pressurized liquid extraction and maceration. Chemical profiles were determined on calli extracts of 3, 6, 9, and 15 days of culture; chemical characterization and quantification of compounds was carried out using ultrahigh performance liquid chromatography‐mass spectrometry. A total of 53 metabolites were identified in callus and 47 compounds in leaf extracts, of which 25 correspond to phenolic compounds, mainly flavonoids and flavones, 13 terpenes that include phenolic terpenes and one diterpenolactone, two glycosides which correspond to 6‐O‐caffeoyl‐β‐D‐fructofuranosil‐(2→1)‐α‐D‐glucopyranoside and primulaverin, an aromatic compound identified as fenantrenone and a growth regulator 12‐hydroxy jasmonic acid. These results showed that undifferentiated rosemary cells accumulate the same compounds identified mainly in highly specialized tissues such as leaves. The plant cell culture supply the possibility of developing biotechnological processes to obtain compounds of commercial interest.
Sarcopenia is generally an age-related condition that directly impacts the quality of life. It is also related to chronic diseases such as metabolic dysfunction associated with diabetes and obesity. ...This means that everyone will be vulnerable to sarcopenia at some point in their life. Research to find the precise molecular mechanisms implicated in this condition can increase knowledge for the better prevention, diagnosis, and treatment of sarcopenia. Our work gathered the most recent research regarding inflammation in sarcopenia and new therapeutic agents proposed to target its consequences in pyroptosis and cellular senescence. Finally, we compared dual X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and ultrasound (US) as imaging techniques to diagnose and follow up on sarcopenia, indicating their respective advantages and disadvantages. Our goal is for the scientific evidence presented here to help guide future research to understand the molecular mechanisms involved in sarcopenia, new treatment strategies, and their translation into clinical practice.
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