492 research outputs found

    Visual And Acoustic Communication In The Brazilian Torrent Frog, Hylodes Asper (anura: Leptodactylidae)

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    We studied the signaling, territorial, and courtship behaviors of the diurnal frog Hylodes asper. Visual and acoustic communication were used during intraspecific interactions involving males, females, and subadults. Hylodes asper has a complex visual communication system, of which foot-flagging is the most distinctive display observed in the repertoire of visual signals. The splash zone produced by the waterfalls and torrents creates a high, nearly constant, humidity near the streams, reducing the risk of desiccation which enables the diurnal activity of H. asper. Although the ambient sound pressure levels (SPL), measured at the calling sites, are similar to the SPL of the advertisement calls, the high-pitched calls of H. asper are spectrally different from the noise produced by the water current. Thus, the ambient noise produced by the water current may not interfere significantly with the acoustic communication of this species. The noise and the nearly constant and high humidity produced by the torrents and waterfalls, along with the availability of light, probably favored the evolution of contrasting colors and visual communication in H. asper. Males of H. asper excavate underwater chambers that are probably used to shelter the eggs and to prevent the clutch from being drifted downstream.553324333Cardoso, A.J., Haddad, C.F.B., Variabilidade acústica em diferentes populações e interações agressivas de hyla minuta (amphibia, anura) (1984) Ciência e Cultura, 36, pp. 1393-1399Castanho, L.M., (1994) História Natural de Phyllomedusa Distincta, Na Mata Atlântica Do Município de Sete Barras, Estado de São Paulo (Amphibia, Anura, Hylidae), , M.S. Thesis, Universidade Estadual de Campinas, Campinas, São Paulo, BrasilDavison, G.W.H., Foot-flagging display in Bornean frogs (1984) Sarawak Museum Journal, 33, pp. 177-178Dubois, A., Martens, J., A case of possible vocal convergence between frogs and a bird in Himalayan torrents (1984) Journal für Ornithologie, 125, pp. 455-463Duellman, W.E., Truee, L., (1986) Biology of Amphibians, , McGraw-Hill, New York, New York, U.S.ADurant, P., Dole, J.W., Aggressive behavior in Colostethus (= Prostherapis) collaris (Anura: Dendrobatidae) (1975) Herpetologica, 31, pp. 23-26Faria, D.M., Casais, L.L., Silva, E., Rodrigues, M.T., (1993) Nota Sobre a Reprodução de Hylodes Phyllodes (Anura, Leptodactylidae), p. 150. , Livro de resumos, 3° Congresso Latino-Americano de Herpetologia, Campinas, São Paulo, BrasilFrost, D.R., Amphibian species of the world (1985) A Taxonomic and Geographical Reference, , Allen Press and The Association of Systematics Collections, Lawrence, Kansas, U.S.AGerhardt, H.C., Communication and the environment (1983) Animal Behaviour, Vol. 2: Communication, 2, pp. 82-113. , T. R. Halliday and P. J. B. Slater (Eds.), W. H. Freeman, New York, New York, U.S.AGiaretta, A.A., Bokermann, W.C.A., Haddad, C.F.B., A review of the genus Megaelosia (Anura: Leptodactylidae) with a description of a new species (1993) Journal of Herpetology, 27, pp. 276-285Gouvêa, H., Uma nova espécie de elosiineo da serra do itatiaia (amphibia, anura, leptodactylidae) (1979) Revista Brasileira de Biologia, 39, pp. 855-859Haddad, C.F.B., Pombal J.P., Jr., Bastos, R.P., New species of Hylodes from the Atlantic Forest of Brazil (Amphibia: Leptodactylidae) (1996) Copeia, 1996, pp. 965-969Haddad, C.F.B., Sazima, I., Anfibios anuros da serra do japi (1992) História Natural Da Serra Do Japi: Ecologia e Preservação de Uma Área Florestal No Sudeste Do Brasil, pp. 188-211. , L. P. C. Morellato (Ed.), Editora da UNICAMP/FAPESP, Campinas, São Paulo, BrasilHarding, K.A., Courtship display in a Bornean frog (1982) Proceedings of the Biological Society of Washington, 95, pp. 621-624Heyer, W.R., Two new species of the frog genus Hylodes from Caparaó, Minas Gerais, Brasil (Amphibia: Leptodactylidae) (1982) Proceedings of the Biological Society of Washington, 95, pp. 377-385Heyer, W.R., Cocroft, R.B., Descriptions of two new species of Hylodes from the Atlantic forests of Brazil (Amphibia: Leptodactylidae) (1986) Proceedings of the Biological Society of Washington, 99, pp. 100-109Heyer, W.R., Rand, A.S., Cruz, C.A.G., Peixoto, O.L., Nelson, C.E., Frogs of Boracéia (1990) Arquivos de Zoologia, São Paulo, 31, pp. 231-410Hödl, W., Rodrigues, M.T., Acçaçio, G.M., Lara, P.H., Pavan, D., Schiesari, L.C., Skuk, G., (1997) Foot-flagging Display in the Brazilian Stream-breeding Frog Hylodes Asper (Leptodactylidae), , Austrian Federal Institut of Scientific Film (ÖWF), Vienna, Austria. [Film Ctf 2703]Lehner, P.N., (1979) Handbook of Ethological Methods, , Garland STPM Press, New York, New York, U.S.ALindquist, E.D., Hetherington, T.E., Field studies on visual and acoustic signaling in the "earless" Panamanian golden frog, Atelopus zeteki (1996) Journal of Herpetology, 30, pp. 347-354Martins, M., Biologia reprodutiva de leptodactylus fuscus em boa vista, roraima (amphibia, anura) (1988) Revista Brasileira de Biologia, 48, pp. 969-977Observations on the reproductive behaviour in the Smith frog, Hyla faber (1993) Herpetological Journal, 3, pp. 31-34Martins, M., Pombal J.P., Jr., Haddad, C.F.B., Escalated aggressive behaviour and facultative parental care in the nest building gladiator frog, Hyla faber (1998) Amphibia-Reptilia, 19, pp. 65-73Pombal J.P., Jr., Sazima, I., Haddad, C.F.B., Breeding behavior of the pumpkin toadlet, Brachycephalus ephippium (Brachycephalidae) (1994) Journal of Herpetology, 28, pp. 516-519Richards, S.J., James, C., (1992) Foot-Flagging Displays of Some Australian Frogs Memoirs of the Queensland Museum, 32, p. 302Vielliard, J.M.E., Cardoso, A.J., Adaptações de sinais sonoros de anfibios e aves a ambientes de riachos com corredeiras (1996) Herpetologia Neotropical: Actas del II Congreso Latinoamerieano de Herpetología, 2, pp. 97-119. , J. E. Pefaur (Ed.), Univ. de Los Andes, Consejo de Publ., Consejo de Desarrolo Cientifico, Humanistico y Tecnologico, Merida, VenezuelaWells, K.D., Social behavior and communication of a dendrobatid frog (Colostethus trinitatis) (1980) Herpetologica, 36, pp. 189-199The effect of social interactions on anuran vocal behavior (1988) The Evolution of the Amphibian Auditory System, pp. 433-454. , B. Fritzsch, M. J. Ryan, W. Wilezynsky, T. E. Hetherington, and W. Walkowiak (Eds.), John Wiley & Sons, New York, New York, U.S.AWeygoldt, P., Carvalho E Silva, S.P., Mating and oviposition in the hylodine frog Crossodactylus gaudichaudii (Anura: Leptodactylidae) (1992) Amphibia-Reptilia, 13, pp. 35-45Winter, J., Macdonald, R., Eungella: The land of the cloud (1986) Australian Natural History, 22, pp. 39-43Zar, J.H., (1996) Biostatistical Analysis, 3rd Ed., , Prentice-Hall, Upper Saddle River, New Jersey, U.S.

    PRS11 Assessment of Knowledge About Tuberculosis Among Libyan and Non Libyan Populations in North East Libya

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    Heterogeneous Multi-Robot Collaboration for Coverage Path Planning in Partially Known Dynamic Environments

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    This research presents a cooperation strategy for a heterogeneous group of robots that comprises two Unmanned Aerial Vehicles (UAVs) and one Unmanned Ground Vehicles (UGVs) to perform tasks in dynamic scenarios. This paper defines specific roles for the UAVs and UGV within the framework to address challenges like partially known terrains and dynamic obstacles. The UAVs are focused on aerial inspections and mapping, while UGV conducts ground-level inspections. In addition, the UAVs can return and land at the UGV base, in case of a low battery level, to perform hot swapping so as not to interrupt the inspection process. This research mainly emphasizes developing a robust Coverage Path Planning (CPP) algorithm that dynamically adapts paths to avoid collisions and ensure efficient coverage. The Wavefront algorithm was selected for the two-dimensional offline CPP. All robots must follow a predefined path generated by the offline CPP. The study also integrates advanced technologies like Neural Networks (NN) and Deep Reinforcement Learning (DRL) for adaptive path planning for both robots to enable real-time responses to dynamic obstacles. Extensive simulations using a Robot Operating System (ROS) and Gazebo platforms were conducted to validate the approach considering specific real-world situations, that is, an electrical substation, in order to demonstrate its functionality in addressing challenges in dynamic environments and advancing the field of autonomous robots.The authors also would like to thank their home Institute, CEFET/RJ, the federal Brazilian research agencies CAPES (code 001) and CNPq, and the Rio de Janeiro research agency, FAPERJ, for supporting this work.info:eu-repo/semantics/publishedVersio

    Unmasking the interplay between mTOR and Nox4: novel insights into the mechanism connecting diabetes and cancer

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    Cancer was recently annexed to diabetic complications. Furthermore, recent studies suggest that cancer can increase the risk of diabetes. Consequently, diabetes and cancer share many risk factors, but the cellular and molecular pathways correlating diabetes and colon and rectal cancer (CRC) remain far from understood. In this study, we assess the effect of hyperglycemia on cancer cell aggressiveness in human colon epithelial adenocarcinoma cells in vitro and in an experimental animal model of CRC. Our results show that Nox (NADPH oxidase enzyme) 4-induced reactive oxygen species (ROS) production is deregulated in both diabetes and CRC. This is paralleled by inactivation of the AMPK and activation of the mammalian target of rapamycin (mTOR) C1 signaling pathways, resulting in 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) accumulation, induction of DNA damage, and exacerbation of cancer cell aggressiveness, thus contributing to the genomic instability and predisposition to increased tumorigenesis in the diabetic milieu. Pharmacologic activation of AMPK, inhibition of mTORC1, or blockade of Nox4 reduce ROS production, restore the homeostatic signaling of 8-oxoguanine DNA glycosylase/8-oxodG, and lessen the progression of CRC malignancy in a diabetic milieu. Taken together, our results identify the AMPK/mTORC1/Nox4 signaling axis as a molecular switch correlating diabetes and CRC. Modulating this pathway may be a strategic target of therapeutic potential aimed at reversing or slowing the progression of CRC in patients with or without diabetes.-Mroueh, F. M., Noureldein, M., Zeidan, Y. H., Boutary, S., Irani, S. A. M., Eid, S., Haddad, M., Barakat, R., Harb, F., Costantine, J., Kanj, R., Sauleau, E.-A., Ouhtit, A., Azar, S. T., Eid, A. H., Eid, A. A. Unmasking the interplay between mTOR and Nox4: novel insights into the mechanism connecting diabetes and cancer.Scopu

    Power-law entropy-corrected HDE and NADE in Brans-Dicke cosmology

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    Considering the power-law corrections to the black hole entropy, which appear in dealing with the entanglement of quantum fields inside and outside the horizon, the holographic energy density is modified accordingly. In this paper we study the power-law entropy-corrected holographic dark energy in the framework of Brans-Dicke theory. We investigate the cosmological implications of this model in detail. We also perform the study for the new agegraphic dark energy model and calculate some relevant cosmological parameters and their evolution. {As a result we find that this model can provide the present cosmic acceleration and even the equation of state parameter of this model can cross the phantom line wD=1w_D=-1 provided the model parameters are chosen suitably}.Comment: 14 pages, 2 figure, accepted by IJT

    A Helicity-Based Method to Infer the CME Magnetic Field Magnitude in Sun and Geospace: Generalization and Extension to Sun-Like and M-Dwarf Stars and Implications for Exoplanet Habitability

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    Patsourakos et al. (Astrophys. J. 817, 14, 2016) and Patsourakos and Georgoulis (Astron. Astrophys. 595, A121, 2016) introduced a method to infer the axial magnetic field in flux-rope coronal mass ejections (CMEs) in the solar corona and farther away in the interplanetary medium. The method, based on the conservation principle of magnetic helicity, uses the relative magnetic helicity of the solar source region as input estimates, along with the radius and length of the corresponding CME flux rope. The method was initially applied to cylindrical force-free flux ropes, with encouraging results. We hereby extend our framework along two distinct lines. First, we generalize our formalism to several possible flux-rope configurations (linear and nonlinear force-free, non-force-free, spheromak, and torus) to investigate the dependence of the resulting CME axial magnetic field on input parameters and the employed flux-rope configuration. Second, we generalize our framework to both Sun-like and active M-dwarf stars hosting superflares. In a qualitative sense, we find that Earth may not experience severe atmosphere-eroding magnetospheric compression even for eruptive solar superflares with energies ~ 10^4 times higher than those of the largest Geostationary Operational Environmental Satellite (GOES) X-class flares currently observed. In addition, the two recently discovered exoplanets with the highest Earth-similarity index, Kepler 438b and Proxima b, seem to lie in the prohibitive zone of atmospheric erosion due to interplanetary CMEs (ICMEs), except when they possess planetary magnetic fields that are much higher than that of Earth.Comment: http://adsabs.harvard.edu/abs/2017SoPh..292...89

    The effects of viral load burden on pregnancy loss among HIV-infected women in the United States

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    Background. To evaluate the effects of HIV viral load, measured cross-sectionally and cumulatively, on the risk of miscarriage or stillbirth (pregnancy loss) among HIV-infected women enrolled in the Women's Interagency HIV Study between 1994 and 2013. Methods. We assessed three exposures: most recent viral load measure before the pregnancy ended, log10 copy-years viremia from initiation of antiretroviral therapy (ART) to conception, and log10 copy-years viremia in the two years before conception. Results. The risk of pregnancy loss for those with log10 viral load >4.00 before pregnancy ended was 1.59 (95% confidence interval (CI): 0.99, 2.56) times as high as the risk for women whose log10 viral load was ≤1.60. There was not a meaningful impact of log10 copy-years viremia since ART or log10 copy-years viremia in the two years before conception on pregnancy loss (adjusted risk ratios (aRRs): 0.80 (95% CI: 0.69, 0.92) and 1.00 (95% CI: 0.90, 1.11), resp.). Conclusions. Cumulative viral load burden does not appear to be an informative measure for pregnancy loss risk, but the extent of HIV replication during pregnancy, as represented by plasma HIV RNA viral load, predicted loss versus live birth in this ethnically diverse cohort of HIV-infected US women
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