RESUMO
Galls are plant neoformations induced by specialized parasites. Since gall inducers rely on reactive plant sites for gall development, variations in abiotic factors that affect plant phenology are expected to impact the life cycle of gall inducers. To test the hypothesis that different light conditions affect both host plant and gall inducer life cycles, we studied the system Eugenia uniflora (Myrtaceae) - Clinodiplosis profusa (Cecidomyiidae), comparing plants occurring in sunny and shaded environments. We mapped phenological differences among individuals of E. uniflora occurring in the two environments and related them to the influence of luminosity on the life cycle of the gall inducer. Shade plants showed lower intensity of leaf sprouting throughout the year compared to sun-exposed plants, especially during the rainy season. Young and mature galls are synchronized with the peak of leaf sprouting at the beginning of the rainy season, lasting longer in sun-exposed plants - approximately two months longer compared to shade plants. The greater light intensity positively impacts the formation and growth of leaves and galls, with an extended period available for their induction and growth. Thus, light is an important factor for the development of gallers, considering that variations in luminosity influenced not only the phenology of the host plant, but also determined the life cycle of gall inducers. Furthermore, changes in plant-environment interactions are expected to affect the life cycle and richness of other host plant-gall inducer systems.
Assuntos
Eugenia , Luz Solar , Eugenia/fisiologia , Animais , Tumores de Planta/parasitologia , Luz , Folhas de Planta/parasitologia , Folhas de Planta/fisiologia , Estações do Ano , Interações Hospedeiro-Parasita/fisiologia , Estágios do Ciclo de Vida/fisiologiaRESUMO
The risk of fungal pollution in drinking water has been paid attention. Solar/chlorine dioxide (ClO2) combined system is an environment-friendly, economical and efficient disinfection method, especially for countries and regions that are economically backward and still exposed to unsafe drinking water. In this paper, the kinetics, influencing factors, mechanism and regrowth potential of inactivated Aspergillus niger (A. niger) spores by solar/ClO2 were reported for the first time. The inactivation curve can be divided into three stages: instant inactivation within 1-2 min, slow linear inactivation and finally a tail. The synergistic factors produced by solar/ClO2 in terms of log reduction and maximum inactivation rate were 1.194 and 1.112, respectively. The inhibitory effect on the regrowth of A. niger spores inactivated by solar/ClO2 was also stronger than that by ClO2 alone. Strongly oxidizing reactive species produced by solar/ClO2 accelerated the accumulation of endogenic reactive oxygen species (ROS) caused by oxidation stress of A. niger spores, improving the inactivation ability of the system. The inactivation order of A. niger spores was: loss of culturability, accumulation of intracellular ROS, loss of membrane integrity, leakage of intracellular species and change of morphology. The inactivation performance of solar/ClO2 was better than solar/chlor(am)ine according to the comparison of inactivation efficiency and regrowth potential. Results also suggested that solar/ClO2 process was more suitable for the treatment of ground water sources.
Assuntos
Compostos Clorados , Desinfecção , Água Potável , Óxidos , Esporos Fúngicos , Água Potável/microbiologia , Compostos Clorados/farmacologia , Desinfecção/métodos , Desinfetantes/farmacologia , Purificação da Água/métodos , Aspergillus niger , Luz Solar , Microbiologia da ÁguaRESUMO
The variation in light within the environment triggers morphophysiological changes in plants and can lead to distinct responses in sun-exposed or shaded plants to glyphosate. The response of Urochloa genotypes subjected to desiccation with 2160, 1622.4, 1080, 524.4, 273.6, and 0.0 g ha-1 of glyphosate was evaluated in full sun and shade conditions. Cayana grass, mulato II grass, and sabiá grass - hybrids recently launched on the market, in addition to palisade grass and congo grass were evaluated. Under full sun, we achieved control of congo grass using 1080 g ha-1 of glyphosate, while the other grasses required 2160 g ha-1. In the low-light environment, sabiá grass was effectively controlled with 524.4 g ha-1 of glyphosate, but the other grasses needed 273.6 g ha-1. In shading, compared to full sun, the savings with glyphosate were 75 and 76% for the control of congo grass and sabiá grass, respectively, and 87% for palisade grass, mulato II grass and cayana grass. Increasing glyphosate doses leads to a decline in the quantum efficiency of photosystem II and in the electron transport rate, especially in the shade. Urochloa genotypes are more sensitive to glyphosate in the shade, which must be considered when determining the herbicide dose.
Assuntos
Glicina , Glifosato , Herbicidas , Poaceae , Glicina/análogos & derivados , Glicina/farmacologia , Herbicidas/farmacologia , Poaceae/efeitos dos fármacos , Poaceae/efeitos da radiação , Poaceae/genética , Poaceae/metabolismo , Luz , Luz SolarRESUMO
Amazonia contains the most extensive tropical forests on Earth, but Amazon carbon sinks of atmospheric CO2 are declining, as deforestation and climate-change-associated droughts1-4 threaten to push these forests past a tipping point towards collapse5-8. Forests exhibit complex drought responses, indicating both resilience (photosynthetic greening) and vulnerability (browning and tree mortality), that are difficult to explain by climate variation alone9-17. Here we combine remotely sensed photosynthetic indices with ground-measured tree demography to identify mechanisms underlying drought resilience/vulnerability in different intact forest ecotopes18,19 (defined by water-table depth, soil fertility and texture, and vegetation characteristics). In higher-fertility southern Amazonia, drought response was structured by water-table depth, with resilient greening in shallow-water-table forests (where greater water availability heightened response to excess sunlight), contrasting with vulnerability (browning and excess tree mortality) over deeper water tables. Notably, the resilience of shallow-water-table forest weakened as drought lengthened. By contrast, lower-fertility northern Amazonia, with slower-growing but hardier trees (or, alternatively, tall forests, with deep-rooted water access), supported more-drought-resilient forests independent of water-table depth. This functional biogeography of drought response provides a framework for conservation decisions and improved predictions of heterogeneous forest responses to future climate changes, warning that Amazonia's most productive forests are also at greatest risk, and that longer/more frequent droughts are undermining multiple ecohydrological strategies and capacities for Amazon forest resilience.
Assuntos
Resistência à Seca , Secas , Florestas , Água Subterrânea , Fotossíntese , Solo , Luz Solar , Árvores , Brasil , Sequestro de Carbono , Secas/estatística & dados numéricos , Água Subterrânea/análise , Solo/química , Árvores/classificação , Árvores/metabolismo , Árvores/fisiologia , Clima Tropical , Resistência à Seca/fisiologia , Filogeografia , Conservação dos Recursos NaturaisRESUMO
This study explored the photocatalytic hydrogen evolution reaction (HER) using novel biohydrogel composites comprising chitosan, and a photocatalyst consisting in TiO2 P25 decorated with Au and/or Cu mono- and bimetallic nanoparticles (NPs) to boost its optical and catalytic properties. Low loads of Cu and Au (1 mol%) were incorporated onto TiO2 via a green photodeposition methodology. Characterization techniques confirmed the incorporation of decoration metals as well as improvements in the light absorption properties in the visible light interval (λ > 390 nm) and electron transfer capability of the semiconductors. Thereafter, Au and/or Cu NP-supported TiO2 were incorporated into chitosan-based physically crosslinked hydrogels revealing significant interactions between chitosan functional groups (hydroxyls, amines and amides) with the NPs to ensure its encapsulation. These materials were evaluated as photocatalysts for the HER using water and methanol mixtures under simulated sunlight and visible light irradiation. Sample CuAuTiO2/ChTPP exhibited a maximum hydrogen generation of 1790 µmol g-1 h-1 under simulated sunlight irradiation, almost 12-folds higher compared with TiO2/ChTPP. Also, the nanocomposites revealed a similar tendency under visible light with a maximum hydrogen production of 590 µmol g-1 h-1. These results agree with the efficiency of photoinduced charge separation revealed by transient photocurrent and EIS.
Assuntos
Quitosana , Cobre , Hidrogéis , Hidrogênio , Luz Solar , Titânio , Quitosana/química , Titânio/química , Catálise , Hidrogênio/química , Cobre/química , Hidrogéis/química , Ouro/química , Processos Fotoquímicos , Nanocompostos/química , Nanopartículas Metálicas/químicaRESUMO
Skin aging is the result of physiological changes determined by genetically driven processes and intrinsic factors, and exacerbated by a combination of multiple environmental factors, the main one being sun exposure. The effects of photoaging are particularly apparent on the face, where the appearance of aging signs can have a significant impact on the emotions conveyed and well-being. Photoprotection and facial skin care for managing photoaging signs are thus of particular importance for both physical and mental health. Countries, like Australia and Brazil, where the level of sun exposure is high and the populations have predominantly outdoor lifestyles, are particularly aware of the harms of photoaging and have implemented several measures to help reduce the risk of skin cancer in their populations. However, sun-seeking behaviours are difficult to change, and it takes time before interventions provide perceptible results. Australia still has some of the highest skin cancer incidence and mortality rates in the world. Solutions that target individuals can also be used for minimizing the clinical signs of facial aging and for improving skin quality, with the ultimate aim being not only to improve the appearance of the skin but also to mitigate the occurrence of pre-malignant and malignant lesions. This review summarizes the features of facial skin photoaging in photo-exposed populations, based on evidence gained from studies of Australian individuals, and discusses the various available solutions for skin photoaging, in particular those that are most popular in Brazil, which is a country with many years of experience in managing photoaged skin.
Assuntos
Cosmecêuticos , Envelhecimento da Pele , Luz Solar , Protetores Solares , Humanos , Brasil , Austrália , Luz Solar/efeitos adversos , Protetores Solares/uso terapêutico , Cosmecêuticos/uso terapêutico , Neoplasias Cutâneas/prevenção & controle , Neoplasias Cutâneas/etiologia , FaceRESUMO
BACKGROUND: Photoprotection is the first measure in the prevention and treatment of the deleterious effects that sunlight can cause on the skin. It is well known that prolonged exposure to solar radiation leads to acute and chronic complications, such as erythema, accelerated skin aging, proinflammatory and procarcinogenic effects, and eye damage, among others. METHODS: A better understanding of the molecules that can protect against ultraviolet radiation and their effects will lead to improvements in skin health. RESULTS: Most of these effects of the sunlight are modulated by oxidative stress and proinflammatory mechanisms, therefore, the supplementation of substances that can regulate and neutralize reactive oxygen species would be beneficial for skin protection. Current evidence indicates that systemic photoprotection should be used as an adjunctive measure to topical photoprotection. CONCLUSION: Oral photoprotectors are a promising option in improving protection against damage induced by UVR, as they contain active ingredients that increase the antioxidant effects of the body, complementing other photoprotection measures. We present a review of oral photoprotectors and their effects.
Assuntos
Substâncias Protetoras , Raios Ultravioleta , Humanos , Administração Oral , Antioxidantes/administração & dosagem , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Pele/metabolismo , Pele/efeitos da radiação , Pele/efeitos dos fármacos , Luz Solar/efeitos adversos , Raios Ultravioleta/efeitos adversos , Substâncias Protetoras/administração & dosagemRESUMO
Chrysophyllum rufum leaves collected under different light conditions provide information on how this fact can influence the morphology of the species. The anatomy techniques applied to the samples showed that there were discreet differences in the characters considered diagnostic. This indicates that the plant is capable of adapting, despite its prevalence in both dry and humid environments. The pollen grains were acetolyzed, measured, described qualitatively, analyzed quantitatively, and illustrated using light microscopy (LM).
Assuntos
Folhas de Planta , Pólen , Sapotaceae , Folhas de Planta/anatomia & histologia , Folhas de Planta/química , Pólen/anatomia & histologia , Sapotaceae/anatomia & histologia , Sapotaceae/química , Luz Solar , LuzRESUMO
Photoaging is the premature aging of the skin caused by prolonged exposure to solar radiation. The visual alterations manifest as wrinkles, reduced skin elasticity, uneven skin tone, as well as other signs that surpass the expected outcomes of natural aging. Beyond these surface changes, there is a complex interplay of molecular alterations, encompassing shifts in cellular function, DNA damage, and protein composition disruptions. This data descriptor introduces a unique dataset derived from ten individuals, each with a minimum of 18 years of professional experience as a driver, who are asymmetrically and chronically exposed to solar radiation due to their driving orientation. Skin samples were independently collected from each side of the face using a microdermabrasion-like procedure and analyzed on an Exploris 240 mass spectrometer. Our adapted proteomic statistical framework leverages the sample pairing to provide robust insights. This dataset delves into the molecular differences in exposed skin and serves as a foundational resource for interdisciplinary research in photodermatology, targeted skincare treatments, and computational modelling of skin health.
Assuntos
Face , Espectrometria de Massas , Proteômica , Envelhecimento da Pele , Pele , Pele/efeitos da radiação , Pele/metabolismo , Humanos , Luz SolarRESUMO
The global population is at risk of vitamin D deficiency due to low exposure to sunlight and low intake of the vitamin through diet. The aim of this study was to investigate in women the association between vitamin D status and parathyroid hormone (PTH), ultraviolet radiation, lifestyle, ethnicity, social conditions, and residential greenness. A 1-year longitudinal study assessed vitamin D status in 309 women living at latitude 51°14' N. Blood samples were taken four times throughout the year for analysis of 25(OH)D and serum PTH concentration. After each seasonal visit, the individuals completed 4-day diet diaries and used two dosimeter badges for 1 week to estimate weekly UVR exposure. A questionnaire was applied to provide information about lifestyle and their ethnicity. Residential greenness was measured by Normalized Difference Vegetation Index (NDVI), within a 1000 m radius around each participant's home address. Women living in greener spaces were more likely to have improved vitamin D status (RR: 1.51; 95%CI: 1.13-2.02), as well as those who were more exposed to UVR (RR: 2.05; 95%CI: 1.44-2.92). Our results provide an insight into the connection between residential greenness, lifestyle, and vitamin D status comparing two ethnicities in a country with a temperate climate and with a high degree of urbanization.