267 research outputs found

    Taxonomic Partition Suggests a High Degree of Coevolution Between Termites and Their Termitophiles

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    Termites have a tight interaction with their social parasitic Corotocini beetles. This association is thought to be mainly host-specific, despite some host-switch events. By analyzing the taxonomic partition between species and genera of Corotocini, we propose the hypothesis that the main driver of the diversity of these termitophiles is coevolution

    Curva cumulativa de descrição de espécies de Corotocini (Aleocharinae, Staphylinidae) e perspectivas para o futuro

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    This study deals with the global estimation of the species of Corotocini (Aleocharinae) based on taxonomic description rates. We estimate the maximum number of possible extant species by maximum likelihood using the Michaelis-Menten model fitted into a non-linear regression. Although the studies regarding Corotocini are majorly taxonomic descriptions, the results suggest that there are many yet undescribed species, We also highlight that the basic knowledge regarding these organisms ecology is fairly obscure. Since the discovery of the first organism living in association with termites, the taxonomic effort hasn't been constant along the years, and although our results suggest that many species lie undiscovered, the lack of specialized professionals can compromise the actual knowledge regarding their biodiversity. Besides that, we comment on the future of this field and the lack of specimens from various locations.Este estudo trata da estimativa global das espécies de Corotocini (Aleocharinae) com base nas taxas de descrição taxonômica. Estimamos o número máximo possível de espécies existentes por probabilidade máxima usando o modelo de Michaelis-Menten ajustado em a uma regressão não-linear. Apesar dos trabalhos envolvendo Corotocini serem majoritariamente taxonômicos, os resultados sugerem que ainda existem muitas espécies sem descrição, além de que o conhecimento básico a respeito da ecologia destes organismos seja bastante obscuro. Desde a descoberta dos primeiros organismos vivendo em associação com cupins, o esforço taxonômico dedicado a esse grupo não foi constante com o passar dos anos, e apesar de os resultados sugerirem que muitas espécies ainda podem ser descobertas, a falta de profissionais especializados no grupo pode comprometer o conhecimento real acerca de diversidade destes organismos. Além disso, comentamos o futuro desse campo de estudo e a falta de espécimes de outras localidades

    Ação do ácido quetomélico nas alterações hematológicas induzidas pela redução de 5/6 de massa renal em ratos

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    A doença renal crónica está associada com o desenvolvimento de anemia devido principalmente à diminuição da produção de eritropoetina. O ácido quetomélico (AC) é um potente inibidor seletivo da farnesil transferase e, desta forma, inibe as vias de sinalização que levam à progressão da fibrose renal. Assim, o objectivo deste trabalho foi o de estudar os efeitos do tratamento crónico com o AC nas alterações hematológicas induzidas pela redução de 5/6 de massa renal (RMR). Neste estudo foram utilizados 70 ratos machos da estirpe Wistar. Uma semana após a redução cirúrgica de 5/6 de massa renal, os animais foram divididos em quatro grupos experimentais: CO: animais em que se simulou a cirurgia e sem tratamento; CO+AC: animais em que se simulou a cirurgia e tratados com o AC; RMR: animais com RMR e não tratados; RMR+AC: animais com RMR e tratados com o AC. O tratamento foi administrado por via intraperitoneal, durante seis meses. Para o estudo hematológico procedeu-se à contagem manual, em câmara de Neubauer, do número total de eritrócitos e de leucócitos, à determinação do microhematócrio, à contagem diferencial de leucócitos e à estimativa do número total de plaquetas no esfregaço de sangue corado com Diff-Quick. Nos grupos RMR e RMR+AC observou-se um aumento estatisticamente significativo (p<0.01) do número total de eritrócitos, do microhematócrito, do número total de leucócitos e das plaquetas, em relação aos grupos CO e CO+AC. Deste modo, os resultados deste estudo sugerem que em ratos Wistar com doença renal crónica, o tratamento com o AC, durante seis meses, não diminui a gravidade da anemia, da leucocitose e da trombocitose induzidas pela redução de 5/6 de massa renal

    Antimicrobial activity of cream incorporated with silver nanoparticles biosynthesized from Withania somnifera

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    We report on the antimicrobial activity of a cream formulation of silver nanoparticles (AgNPs), biosynthesized using Withania somnifera extract. Aqueous extracts of leaves promoted efficient green synthesis of AgNPs compared to fruits and root extracts of W. somnifera. Biosynthesized AgNPs were characterized for their size and shape by physical-chemical techniques such as UV-visible spectroscopy, laser Doppler anemometry, transmission electron microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, and X-ray energy dispersive spectroscopy. After confirming the antimicrobial potential of AgNPs, they were incorporated into a cream. Cream formulations of AgNPs and AgNO3 were prepared and compared for their antimicrobial activity against human pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, and Candida albicans) and a plant pathogen (Agrobacterium tumefaciens). Our results show that AgNP creams possess significantly higher antimicrobial activity against the tested organisms.This work was supported by Fundacao para a Ciencia e Tecnologia (FCT), projects (PTDC/AGR-ALI/105169/2008 and PTDC/AGR-GPL/119211/2010). Gregory Marslin is supported by a FCT PhD fellowship (SFRH/BD/72809/2010).info:eu-repo/semantics/publishedVersio

    Computational Modeling of the Thermal Behavior of a Greenhouse

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    The need for production of all kinds of crops in high quantities and over the entire year makes the agricultural sector one of the major energy consumers. The optimization of this consumption is essential to guarantee its sustainability. The implementation of greenhouses is a strategy that allows assurance of production needs and possesses large optimization potential for the process. This article studies different greenhouse structures by computational simulation using EnergyPlus and DesignBuilder. First, a comparison was performed between the computational results and the measured values from a greenhouse prototype at different operating conditions. Overall, the comparison shows that the computational tool can provide a reasonable prediction of the greenhouse thermal behavior, depending on the differences between the weather data modeled and observed. An outdoor air temperature difference of 16 â—¦C can cause a difference of about 10 â—¦C between the air temperature predicted and measured inside the greenhouse. Subsequently, a selected set of case studies was developed in order to quantify their influence on the thermal performance of the greenhouse, namely: the greenhouse configuration and orientation; the variation of indoor air renewal; changes to the characteristics of the roof; the effect of the thermal mass of the walls; and location of the greenhouse. The results show that a correct greenhouse orientation, together with a polyethylene double cover with a 13 mm air layer, a granite wall of 40 cm thickness on the north wall, and variable airflow rate, may lead to a reduction of the greenhouse energy consumption by 57%, if the greenhouse is located in Lisbon, or by 43%, if it is located in Ostersund, during the harshest months of the heating season.info:eu-repo/semantics/publishedVersio

    The effects of long-term chaetomellic acid a administration on renal function and oxidative stress in a rat model of renal mass reduction

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    This study aimed to evaluate the effect of chronic treatment with chaetomellic acid A (CAA) on oxidative stress and renal function in amodel of renalmass reduction. Methods.MaleWistar ratswere subjected to 5/6 nephrectomy (RMR) or sham-operated (SO). One week after surgery, rats have been divided into four experimental groups: RMR: RMR rats without treatment (n = 14); RMR + CAA: RMR rats treated with CAA (n = 13); SO: SO rats without treatment (n = 13); and SO + CAA: SO rats treated with CAA (n = 13). CAA was intraperitoneally administered in a dose of 0.23 μg/Kg three times a week for six months. Results. RMR was accompanied by a significant reduction in catalase and glutathione reductase (GR) activity (p < 0.05) and a decrease in reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio. CAAadministration significantly increased catalase andGR activity (p < 0.05) and increased GSH/GSSG ratio, but no significant difference between the treated and nontreated groups was found in this ratio.No significant differences were found between theRMRgroups in any of the parameters of renal function.However, CAA administration slightly improves some parameters of renal function. Conclusions. These data suggest that CAA could attenuate 5/6 RMR-induced oxidative stress.The authors would like to thank Jos´e Miguel Lopez- Novoa for valuable comments and suggestions. This work is supported by European Investment Funds by FEDER/ COMPETE/POCI, Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145- FEDER-006958, and National Funds by FCT, Portuguese Foundation for Science and Technology, under Project UID/AGR/04033/2013, and by European Investment Funds by FEDER/COMPETE/POCI, Operational Competitiveness and Internationalization Programme, under Project POCI- 01-0145-FEDER-016728, and National Funds by FCT, Portuguese Foundation for Science and Technology, under Project PTDC/DTP-DES/6077/2014.info:eu-repo/semantics/publishedVersio

    Run to the nest: A parody on the Iron Maiden song by Corotoca spp. (Coleoptera, Staphylinidae)

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    Rove beetles belonging to the genus Corotoca (Staphylinidae: Aleocharinae) are termitophiles exclusively found in nests of Constrictotermes (Isoptera: Termitidae). We observed the reproductive behavior of Corotoca melantho and C.&nbsp;fontesi during host (C.&nbsp;cyphergaster) foraging events. The reproductive behaviors of both species are similar. The variables collected for analysis were distance traveled, the time of larval deposition, nest return time, and locomotion speed. The fact that the female stops in the middle of the foraging trail to deposit the larva leads to a discussion of how its physiological or voluntary mechanisms function to determine the correct stopping time and the importance of speed when returning to the nest as a strategy to avoid predation. This study provides new information concerning the life cycle of Corotoca&nbsp;spp., although complete understanding of host-termitophile relationships, their evolutionary history, and the significance of viviparity will require additional studies

    Critical Soil Health Parameters to Improve Crop Production

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    Soil health is a critical determinant of plant performance. This manuscript describes how the physical, chemical, and biological components within the soil interact to create good soil health. Soil structure is important to provide support for plants, nutrient and water cycling, decreased compaction, and more efficient carbon storage. Measurements of soil properties are presented that can be done in the field on any soil

    State of knowledge of viviparity in Staphylinidae and the evolutionary significance of this phenomenon in Corotoca Schiødte, 1853

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    Viviparity is characterized by the retention of fertilized eggs in reproductive tract of the female. This condition is very common in vertebrates, but relatively rare in invertebrates, including insects. The present work presents a review on viviparity in Staphylinidae, with special attention on genus Corotoca Schiødte, 1853. The genus is composed by six termitophilous species with neotropical distribution, and together with Spirachtha Schiødte, 1853 are only two genera with species confirmed as viviparous in the family. Some other cases are only supposition. Also, it is presented information and discussion on the life cycle of Corotoca species based on dissection of females in laboratory and field observations. During the dissection of females of four species of Corotoca it was observed that each female carries three eggs at the same time. The embryos present asynchronous development: when one is located at apex of abdomen, the other two are at IV segment, on abdomen curvature. These observations are complementary with those obtained in field observation, when the female deposits a larva outside the nest, on the foraging trail of termite Constrictotermes cyphergaster (Silvestri, 1901). The strategy of Corotoca species focused on the immature as dispersing agent is derived and probably favor the fitnees in relation to a hypothetical condition in which the adult is the dispersive agent

    State of knowledge of viviparity in Staphylinidae and the evolutionary significance of this phenomenon in Corotoca Schiødte, 1853

    Get PDF
    Viviparity is characterized by the retention of fertilized eggs in reproductive tract of the female. This condition is very common in vertebrates, but relatively rare in invertebrates, including insects. The present work presents a review on viviparity in Staphylinidae, with special attention on genus Corotoca Schiødte, 1853. The genus is composed by six termitophilous species with neotropical distribution, and together with Spirachtha Schiødte, 1853 are only two genera with species confirmed as viviparous in the family. Some other cases are only supposition. Also, it is presented information and discussion on the life cycle of Corotoca species based on dissection of females in laboratory and field observations. During the dissection of females of four species of Corotoca it was observed that each female carries three eggs at the same time. The embryos present asynchronous development: when one is located at apex of abdomen, the other two are at IV segment, on abdomen curvature. These observations are complementary with those obtained in field observation, when the female deposits a larva outside the nest, on the foraging trail of termite Constrictotermes cyphergaster (Silvestri, 1901). The strategy of Corotoca species focused on the immature as dispersing agent is derived and probably favor the fitnees in relation to a hypothetical condition in which the adult is the dispersive agent
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