Potencial pesqueiro de Macrobrachium amazonicum na Amazonia central (Ilha do Careiro) : variaçao da abundancai e do comprimento

Abundance and body size variations of the prawn #Macrobranchium amazonicum$ (Heller, 1862) have been studied in a Central Amazonian floodplain lake, on Careiro Island. The highest number of captures and smallest sizes have been observed beneath floating macrophyte meadows. This suggests that these meadows serve a nursery habitats. The densities registered in the Amazon river were three times lower than in the lake. Maximum densities were recorded during low water periods, while minimum densities were found during high water periods. These results point to a relationship between current force and catchability. In the floodplain lake, prawn abundance seems to be related to macrophyte expansion during the periods of rising water, the lowest captures were registered at high water, which is probably due to the spatial dispersion as the water volume increases. River prawn populations are characterised by larger sizes than the ones in the lake. (D'après résumé d'auteur

Migraçao vertical nictemeral das larvas de Macrobrachium amazonicum num lago de varzea na Amazonia central, Ilha do Careiro, Brasil

Prawn larvae of #Macrobrachium amazonicum$ have been collected during six diel cycles in the epilimnion (surface and 2 m) from three different habitats of the Lagos do Rei, Careiro Island. The larval distribution showed a significant increase in density at 22 hours regardless of season or habitat, which suggests a diel vertical migration pattern. The thermal stratification of the lake (mean differential of 0.5° between the surface and 2 m and 0.6° between 2 m and 4 m) suggests that this phenomena could be only partly related to a metabolic efficiency resulting from prawns residing at cooler depths during the day. In shallow tropical waters, predation by visually dependant planktivores can be a more important factor in the adaptative significance of the diel distribution of the macrozooplankton than a low thermal stratification. The diurnal feeding activity found in the predominant planktivores fish species of the Careiro lake reinforces this hypothesis. (Résumé d'auteur

Quelques caractéristiques physico-chimiques d'un lac de varzéa en Amazonie centrale (Lago do Rei, île de Careiro)

L'Île de Careiro, dans la région de Manaus, a fait l'objet en 1985-88 de recherches multidisciplinaires concernant les conditions écologiques et économiques de la production d'une île de varzéa. Le Lago do Rei, occupant près de 100km2 dans la partie centrale de l'île pendant les crues, dépend d'autant plus du régime de l'Amazone, et de ce fait de la pluviosité du haut bassin amazonien, qu'il est relié toute l'année au cours principal. Les eaux du lac sont caractérisées par une importante isothermie tout le long de l'année. La teneur en oxygène dissous montre des variations saisonnières et nycthémérales en relation avec l'activité photosynthétique du phytoplancton. Des sursaturations sont observées pendant le maximum des basses et des hautes eaux, et les valeurs minimales en mars-avril, quand les eaux du fleuve envahissent la varzéa. La conductivité augmente lors de la rentrée des eaux du fleuve et lors de leur sortie du lac. Le pH présente des valeurs maximales en mars et minimales en juillet-août en relation avec l'intensité de la photosynthèse dans le lac. Ces conditions limnologiques typiques d'un grand lac de varzéa permettent au Lago do Rei d'être un système particulièrement productif. (Résumé d'auteur

Respiratory evaluation through volumetric capnography among grade III obese and eutrophic individuals: a comparative study

sem informaçãoExcess trunk body fat in obese individuals influences respiratory physiological function. The of this study were to compare volumetric capnography findings (VCap) between severely obese patients and normal-weight subjects and to assess whether there is a1372177183sem informaçãosem informaçãosem informaçã

Seminário - Aplicação dos princípios da ecologia da paisagem a estudos de flora e fauna

Contém os resumos das comunicações e pósteres apresentados durante o evento

Optical Tweezers 3d Photonic Force Spectroscopy

Since optical tweezers trapped microspheres can be used as an ultrasensitive force measurements technique, the knowledge of its theoretical description is of utmost importance. However, even the description of the incident electromagnetic fields under very tight focusing, typical of the optical trap, is not yet a closed problem. Therefore it is important to experimentally obtain whole accurate curves of the force as a function of wavelength, polarization and incident beam 3D position with respect to the center of the microsphere. Theoretical models for optical forces such as the Generalized Lorenz-Mie theory, can then be applied to the precisely evaluated experimental results. Using a dual trap in an upright standard optical microscope, one to keep the particle at the equilibrium position and the other to disturb it we have been able to obtain these force curves as a function of x, y and z position, incident beam polarization and also wavelength. Further investigation of optical forces was conducted for wavelengths in and out Mie resonances of the dielectric microspherical cavities for both TM and TE modes.6131Ashkin, A., Dziedzic, J.M., Bjorkholm, J.E., Chu, S., Observation of a single-beam gradient force trap for dielectric particles (1986) Opt. Lett., 11, pp. 288-290Ashkin, A., Dziedzic, J.M., Optical trapping and manipulation of viruses and bacteria (1987) Science, 235, pp. 1517-1520Grier, D.G., A revolution in optical manipulation (2003) Nature, 424, pp. 810-816Neuman, K.C., Block, S., Optical trapping (2004) Rev. Sci. Instrum., 75, pp. 2787-2809Lock, J.A., Calculation of the radiation trapping force for laser tweezers by use of generalized Lorenz-Mie theory. I. Localized model description of an on-axis tightly focused laser beam with spherical aberration (2004) Appl. Opt., 43, pp. 2532-2544Lock, J.A., Calculation of the radiation trapping force for laser tweezers by use of generalized Lorenz-Mie theory. II. On-axis trapping force (2004) Appl. Opt., 43, pp. 2545-2554Mazolli, A., Neto, P.A.M., Nussenzveig, H.M., Theory of trapping forces in optical tweezers (2003) Proc. Royal Soc. London Ser. A Math. Phys. Eng. Sci., 459, pp. 3021-3041Fontes, A., Neves, A.A.R., Moreira, W.L., De Thomaz, A.A., Barbosa, L.C., De Paula, A.M., Cesar, C.L., Double optical tweezers for ultrasensitive force spectroscopy in microsphere Mie scattering (2005) Appl. Phys. Lett., 87. , Art. No. 221109Ren, K.F., Gouesbet, G., Gréhan, G., Integral localized approximation in generalized Lorenz-Mie theory (1998) Appl. Opt., 37, pp. 4218-4225Lock, J.A., Excitation efficiency of a morphology-dependent resonance by a focused Gaussian beam (1998) J. Opt. Soc. Am. A, 15, pp. 2986-2994Davis, L.W., Theory of electromagnetic beams (1979) Phys. Rev. A, 19, pp. 1177-1779Ren, K.F., Gréhan, G., Gouesbet, G., Radiation pressure forces exerted on a particle arbitrarily located in a gaussian beam by using the generalized Lorenz-Mie theory and associated resonance effects (1994) Opt. Commun., 108, pp. 343-354Ren, K.F., Gréhan, G., Gouesbet, G., Symmetry relations in generalized Lorenz-Mie theory (1994) J. Opt. Soc. Am. A, 11, pp. 1812-181

Propostas para o ensino de geografia física no município de Sobral - CE

Propostas para o ensino de geografia físicano município de Sobral - C

Force Spectroscopy And Two Photon Excited Luminescence In An Optical Tweezers System

Up to now optical spectroscopies have analyzed the scattered light or the heat generated by absorption as a function of the wavelength to get information about the samples. Among the light matter interaction phenomena one that has almost never been used for spectroscopy is the direct photon momenta transfer. Probably because the forces involved are very small, varying from hundreds of femto to tens of pico Newtons. However, the nowadays very popular Optical Tweezers can easily accomplish the task to measure the photon momenta transfer and may be the basis for the Optical Force Spectroscopy. We demonstrate its potential as such a tool by observing more than eight Mie resonance peaks of a single polystyrene microsphere, and showed the capability to selective couple the light to either the TE, TM or both microsphere modes depending of the beam size, the light polarization and the beam positioning. The Mie resonances can change the optical force values by 30-50%. Our results also clearly show how the beam polarization breaks the usually assumed azimuthal symmetry by Optical Tweezers theories. We also obtained the spectrum from the two photon excited luminescence using the Optical Tweezers to hold a single bead suspended and a femtosecond Ti:sapphire laser for the non-linear excitation. This spectrum shows the pair of peaks due to both TE and TM spherical cavity modes. We have been able to observe more than 14 Mie resonance peaks in the TPE luminescence. Our results are in good agreement with optical force calculations using Maxwell stress tensor and partial wave decomposition of the incident beam approximated to a 3th order gaussian beam.593017Ashkin, Dziedzic, J.M., Bjorkholm, J.E., Chu, S., Observation of a single-beam gradient force trap for dielectric particles (1986) Opt. Lett., 11, pp. 288-290Ashkin, A., Dziedzic, J.M., Optical trapping and manipulation of viruses and bacteria (1987) Science, 235, pp. 1517-1520Grier, D.G., A revolution in optical manipulation (2003) Nature, 424, pp. 810-816Felgner, H., Frank, R., Schliwa, M., Flexural rigidity of microtubules measured with the use of optical tweezers (1996) J. Cell Sci., 109, pp. 509-516Sakata-Sogawa, K., Kurachi, M., Sogawa, K., Fujii-Kuriyama, Y., Tashiro, H., Direct measurement of DNA molecular length in solution using optical tweezers: Detection of looping due to binding protein interactions (1998) Eur. Biophys. J., 27, pp. 55-61Berg, H.C., Berry, R.M., Absence of a barrier to backwards rotation of the bacterial flagellar motor demonstrated with optical tweezers (1997) Proc. Natl. Acad. Sci. U.S.A., 94, pp. 14433-14437Huruta, R.R., Mechanical properties of stored red blood cells using optical tweezers (1998) Blood, 92, pp. 2975-2977Brandão, M.M., Optical tweezers for measuring red blood cell elasticity: Application to the study of drug response in sickle cell disease (2003) Eur. J. Haematol., 70, pp. 207-211Ashkin, A., Dziedzic, J.M., (1977) Phys. Rev. Lett., 38, pp. 1351-1355Barber, P.W., Chang, R.K., (1988) Optical Effects Associated with Small Particles, , Word Scientific, SingaporeVan De Hulst, H.C., (1981) Light Scattering by Small Particles, , Dover, New YorkAshkin, A., Dziedzic, J.M., Observation of optical of dieletric particles by light-scattering (1981) Appl. Optics, 20, pp. 1803-1814Benner, R.E., Barber, P.W., Owe, J.F., Chang, R.K., Observation of structure resonances in the fluorescence spectra from microspheres (1980) Physical Review Letters, 44, pp. 475-478Leung, C.H., She, T.C., Lee, W.K., Positions of low order morphology dependent resonances determined by elastic light scattering (1995) J. Opt. Soc. Am. B, 12, pp. 1259-1266Schaschek, K., Popp, J., Kiefer, W., Observation of morphology dependent in- And output-resonances in time dependent Raman spectra of optically levitated microdroplets (1993) J. Raman Spectrosc., 24, pp. 69-75Ashkin, A., Dziedzic, J.M., Observation of resonances in radiation pressure on dieletric particles (1977) Phys. Rev. Lett., 38, pp. 1351-1354Bisht, P.B., Fukuda, K., Hirayama, S., Steady-state and time-resolved fluorescence study of some dyes in polymer microspheres showing morphology dependent resonances (1996) J. Chem. Phys., 105, pp. 9349-9361Arnold, S., Shift of whispering gallery modes in microspheres by protein adsorption (2003) Opt. Lett., 28, pp. 272-274Vollmer, F., Multiplexed DNA quantification by spectroscopic shift of two microsphere cavities (2003) Biophys. J., 85, pp. 1974-1979Ren, K.F., Gréhan, G., Gouesbet, G., Radiation pressure forces exerted on a particle arbitrarily located in a gaussian beam by using the generalized Lorenz-Mie theory and associated resonance effects (1994) Opt. Commun., 108, pp. 343-354Ren, K.F., Gréhan, G., Gouesbet, G., Symmetry relations in generalized Lorenz-Mie theory (1994) J. Opt. Soc. Am. A, 11, pp. 1812-1817Bohren, C.F., Huffman, D.R., (1983) Absorption and Scattering of Light by Small Particles, , Wiley, New YorkVan De Hulst, H.C., (1981) Light Scattering by Small Particles, , Dover, New YorkDavis, L.W., Theory of electromagnetic beams (1979) Phys. Rev. A, 19, pp. 1177-1779Richards, B., Wolf, E., Electromagnetic diffraction in optical systems II. Structure of the image field in an aplanatic system (1959) Proc. R. Soc. London A, 253, pp. 358-379Ren, K.F., Gouesbet, G., Gréhan, G., Integral localized approximation in generalized Lorenz-Mie theory (1998) Appl. Opt., 37, pp. 4218-4225Lock, J.A., Excitation efficiency of a morphology-dependent resonance by a focused Gaussian beam (1998) J. Opt. Soc. Am. A, 15, pp. 2986-2994Bateman, J.B., Weneck, E.J., Eshler, D.C., Determination of Particle Size and Concentration from Spectrophotometric Transmission (1959) J. Colloid Sci., 14, pp. 308-32

Primeiro relato e colonização diferencial de espécies de Passiflora pelo biótipo B de Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) no Brasil

This note is the first report of Bemisia tabaci (Gennadius) biotype B colonizing passionvine in Brazil. We examined the colonization of nine Passiflora species by a wild B type population under greenhouse conditions. P. amethystina Mikan was the most preferred species for oviposition and colonization, whereas P. suberosa L., P. coriacea Juss. and two commercially cultivated species, P. alata Curtis and P. edulis Sims f. flavicarpa Degener, were mostly uncolonised. P. morifolia Mast., P. cincinnata Mast., P. foetida L. and P. caerulea L. showed intermediate levels of colonization. Such differential colonization might suggest some degree of resistance by certain Passiflora species or oviposition preference by B. tabaci.Esse trabalho descreve pela primeira vez a ocorrência do aleirodídeo Bemisia tabaci (Gennadius) biótipo B colonizando maracujazeiros no Brasil. Também foi examinada a colonização de nove espécies de Passiflora pelo inseto em condições de telado. P. amethystina Mikan foi a espécie de maior preferência para oviposição e colonização, enquanto P. suberosa L., P. coriacea Juss. e duas espécies cultivadas comercialmente, P. alata Curtis e P. edulis Sims f. flavicarpa Degener, foram pouco colonizadas pelo aleirodídeo. P. morifolia Mast., P. cincinnata Mast., P. foetida L. e P. caerulea L. exibiram níveis intermediários de colonização. Esses resultados sugerem que certas espécies de Passiflora exibem diferentes graus de resistência à colonização ou preferência para oviposição de B. tabaci biótipo B