Environmental factors driving plant trait distributions in coastal zones of Atlantic Forest

Publisher Copyright: © 2021 Instituto de Pesquisas Jardim Botanico do Rio de Janeiro. All rights reserved.Environmental filtering has been defined as the effect of environmental gradients on species in a plant community and can be the dominant driver of community assembly. Here, we evaluate the relationship between plant communities and the environment in the Restinga vegetation. For this, we measured 11 functional traits of plant species present along transects covering a marked edaphic environmental gradient. This gradient was characterized through Principal Component Analysis of soil characteristics. The relationships between the edaphic gradient and functional traits were evaluated using linear models. Finally, we compared the contributions of species turnover and intraspecific variation to among-site variation in functional traits. The gradients associated with soil nutrients (PCA axis 1) and soil acidity and organic matter (PCA axis 2) were then used to test the observed changes in community composition and were significant predictors of the distribution of water potential, leaf dry matter content and K content, height and chlorophyll index. Decomposing the total variation in the distribution of functional traits between species turnover and intraspecific variation revealed that species turnover explains a greater proportion of the observed variation. We conclude that community assembly is strongly limited by environmental filters and mediated by functional traits at the species level.Peer reviewe

DESINFECÇÃO DA ÁGUA UTILIZANDO PROCESSOS ELETROINTENSIVOS

The realization of the photo-electrochemical process consists in percolating the solution to be treated through an electrolytic reactor, in which the anodes coated with metal oxides remains under the effect of ultraviolet radiation (UV). The solution used in this study was contaminated artificially from fecal samples positive for bacteria and intestinal parasites. The evaluation of the process for the disinfection of water was held in photo-electrical-chemical reactor, with a total volume of 10.0 Lper batch system contaminated with human fecal material. It was used as the -1supporting electrolyte solution of sodium perchlorate at 0.1 mol. Land applying a current density -1of 14 mAwith the aid of a source and a flow rate of 250 L.h. The UVradiation was provided by a mercury vapor lamp of 55 Wwithout bulb shield. The center electrode is inserted through a quartz bulb. Samples were analyzed for pH, conductivity, chemical oxygen demand (COD), and turbidity. Aspects of microbiological and parasitological parameters were treated for 0, 5, 10, 20, and 30 min.. After 30 min., 98.9% reduction in parasitic forms (cysts and eggs) was observed and 99.8% of the colony of Escherichia coliwas present. There was a reduction in COD values (65.7%) and turbidity (92.3%) of samples after treatment exposure, as a result of electrochemical oxidation of organic compounds dissolved in the medium.La realización del proceso de foto-electroquímico consiste en filtrar la solución a ser tratada a través de un reactor electrolítico, en el que los ánodos recubiertos con óxidos de metal permanecen bajo el efecto de la radiación ultravioleta (UV). La solución utilizada en este estudio fue contaminada artificialmente a partir de muestras fecales positivas para las bacterias y los parásitos intestinales. El proceso de evaluación para la desinfección de agua se llevó a cabo en el reactor fotoelectroquímico, con un volumen total de 10,0 Len el sistema de lotes contaminados con material fecal humano. Se utilizó como la solución de electrolito de soporte de perclorato de sodio -1en 0,1 mol.Ly aplicando una densidad de corriente de 14 mAcon la ayuda de una fuente y una -1velocidad de flujo de 250 L.h. La radiación UVfue proporcionada por una lámpara de vapor de mercurio de 55 Wsin bulbo protector, el electrodo central insertado a través de un bulbo de cuarzo. Las muestras se analizaron para el pH, la conductividad, la demanda química de oxígeno (DQO) y la turbidez, y los aspectos de microbiológica y parasitológica en 0, 5, 10, 20, y 30 min de tratamiento. Después de 30 min se observó 98,9% de reducción en formas parasitarias (quistes y huevos) y 99,8% de la colonia de Escherichia colipresente. Hubo una reducción en los valores de DQO (65,7%) y de turbidez (92,3%) de las muestras después de la exposición al tratamiento, como resultado de la oxidación electroquímica de compuestos orgánicos disueltos en el medio.A realização do processo foto-eletroquímico consiste na percolação da solução a ser tratada através de um reator eletrolítico, no qual o anodo revestido com óxidos metálicos permanece sob a incidência da radiação ultravioleta (UV). Asolução utilizada neste estudo foi contaminada artificialmente a partir de amostras fecais positivas para bactérias e parasitas intestinais. Aavaliação do processo na desinfecção da água foi realizada no reator fotoeletroquímico, com volume total de 10,0 Lem sistema de batelada contaminada com material fecal humano. Foi -1utilizado como eletrólito suporte solução de perclorato de sódio a 0,1 mol.Le aplicada uma -1densidade de corrente de 14 mAcom auxílio de uma fonte e uma vazão de 250 L.h. Aradiação UVfoi proporcionada por uma lâmpada a vapor de mercúrio de 55 W, sem bulbo protetor, inserida no centro dos eletrodos por meio de um bulbo de quartzo. As amostras foram analisadas quanto ao pH, condutividade, demanda química de oxigênio (DQO) e turbidez, além dos aspectos microbiológicos e parasitológicos aos 0, 5, 10, 20, e 30 min de tratamento. Após 30 min foi observada uma redução de 98,9% nas formas parasitárias (cistos e ovos) e de 99,8% na colônia de Escherichia colipresente. Observou-se redução nos valores da DQO (65,7%) e da turbidez (92,3%) das amostras após exposição ao tratamento, como consequência da oxidação eletroquímica dos compostos orgânicos dissolvidos no meio

Enhanced Leishmania braziliensis Infection Following Pre-Exposure to Sandfly Saliva

Parasites of the genus Leishmania cause a variety of diseases known as leishmaniasis, that are transmitted by bites of female sand flies that, during blood-feeding, inject humans with parasites and saliva. It was shown that, in mice, immunity to sand-fly saliva is able to protect against the development of leishmaniasis. We have investigated, in the present study, whether this finding extends the sand fly species Lutzomyia intermedia, which is responsible for transmission of Leishmania braziliensis, a parasite species able to cause destructive skin lesions that can be fatal if left untreated. We observed that mice injected with sand fly saliva develop a specific immune response against salivary proteins. Most importantly, however, this immune response was unable to protect mice against a challenge infection with L. braziliensis, indicating that exposure to this sand fly saliva is harmful to the host. Indeed, subjects with cutaneous leishmaniasis have a higher immune response against L. intermedia saliva. These findings indicate that the anti-saliva immune response to sand fly saliva plays an important role in the outcome of leishmaniasis caused by L. braziliensis, in both mice and humans, and emphasize possible hurdles in the development of vaccines based on sand fly saliva

Using Recombinant Proteins from Lutzomyia longipalpis Saliva to Estimate Human Vector Exposure in Visceral Leishmaniasis Endemic Areas

During the blood meal, female sand flies (insects that transmit the parasite Leishmania) inject saliva containing a large variety of molecules with different pharmacological activities that facilitate the acquisition of blood. These molecules can induce the production of anti-saliva antibodies, which can then be used as markers for insect (vector) biting or exposure. Epidemiological studies using sand fly salivary gland sonicate as antigens are hampered by the difficulty of obtaining large amounts of salivary glands. In the present study, we have investigated the use of two salivary recombinant proteins from the sand fly Lutzomyia longipalpis, considered the main vector of visceral leishmaniasis, as an alternative method for screening of exposure to the sand fly. We primarily tested the suitability of using the recombinant proteins to estimate positive anti-saliva ELISA test in small sets of serum samples. Further, we validated the assay in a large sample of 1,077 individuals from an epidemiological survey in a second area endemic for visceral leishmaniasis. Our findings indicate that these proteins represent a promising epidemiological tool that can aid in implementing control measures against leishmaniasis

Discovery of Markers of Exposure Specific to Bites of Lutzomyia longipalpis, the Vector of Leishmania infantum chagasi in Latin America

Leishmania parasites are transmitted by the bite of an infected vector sand fly that injects salivary molecules into the host skin during feeding. Certain salivary molecules can produce antibodies and can be used as an indicator of exposure to a vector sand fly and potentially the disease it transmits. Here we identified potential markers of specific exposure to the sand fly Lutzomyia longipalpis, the vector of visceral leishmaniasis in Latin America. Initially, we determined which of the salivary proteins produce antibodies in humans, dogs, and foxes from areas endemic for the disease. To identify potential specific markers of vector exposure, we produced nine different recombinant salivary proteins from Lu. longipalpis and tested for their recognition by individuals exposed to another human-biting sand fly, Lu. intermedia, that transmits cutaneous leishmaniasis and commonly occurs in the same endemic areas as Lu. longipalpis. Two of the nine salivary proteins were recognized only by humans exposed to Lu. longipalpis, suggesting they are immunogenic proteins and may be useful in epidemiological studies. The identification of specific salivary proteins as potential markers of exposure to vector sand flies will increase our understanding of vector–human interaction, bring new insights to vector control, and in some instances act as an indicator for risk of acquiring disease

Efeito de diferentes reguladores de crescimento na regeneração in vitro de pau-rosa (Aniba rosaeodora Ducke)

O objetivo deste trabalho foi estabelecer um protocolo para a regeneração in vitro de pau-rosa (Aniba rosaeodora Ducke), utilizando brotações apicais e segmentos nodais inoculados em meio de cultura com distintas concentrações de diferentes reguladores de crescimento. Explantes esterilizados com soluções de benomyl (4,0 g.L-1) por 24 horas e hipoclorito de sódio a 20% + tween 20 por 20 minutos, foram submetidos a um experimento de indução de broto, raiz e calo em meio MS1 acrescido de 30g.L-1 de sacarose e 9g.L-1 de agar, suplementado com BAP (0,0 e 4,0 mg.L-1), ANA, AIA e 2,4-D (0,0; 3,0 e 6,0 mg.L-1), e suas respectivas combinações. O delineamento utilizado foi o inteiramente casualizado em esquema fatorial 7 X 2, com 14 tratamentos e 15 repetições cada, onde foram analisados o número médio de brotos, raízes e calo. Após 90 dias, os resultados mostraram que a presença de auxinas é fundamental para a formação dos parâmetros induzidos nos explantes de pau-rosa. O meio de cultura contendo 4,0 mg.L-1 de BAP + 6,0 mg.L-1 de AIA apresentou a melhor média para a brotação com 2,13 brotos/explante. Para o enraizamento o meio contendo 3,0 mg.L-1 de ANA foi o mais eficiente, apresentando uma média de 2,53 raízes/explante. Em relação à indução de calo, todos os tratamentos apresentaram calogênese, porém o meio suplementado com 4,0 mg.L-1 de BAP + 6,0 mg.L-1 de 2,4-D, apresentou a melhor média, 1,67 calos/explante