Perfil dos pescadores esportivos do Sul do Pantanal.

Relatam-se e discutem-se os resultados de um levantamento feito atraves de questionario oral a 493 pescadores esportivos durante a alta temporada de pesca de 1994 no sul do Pantanal. O questionario levantou informacoes socio-economicas, custos e historico das viagens, gastos durante as visitas, razoes da visita e outros aspectos da experiencia de lazer no Pantanal. As principais caracteristicas dos gastos dos pescadores esportivos foram analisadas atraves de tres modelos de regressao linear. Os resultados indicam que a pesca esportiva no sul do Pantanal e realizada por grupos de homens de meia-idade, casados e com educacao formal e situacao economica superior em relacao ao que e tipico no Brasil. Em media, os pescadores ja visitaram a regiao quatro vezes. Realizam viagens de 2.700km, permanecendo seis dias, gastando US$970.00 e capturando 25kg de peixes cada um, por viagem, em media. Em geral, quando maior o nivel de escolaridade, de sucesso na pescaria, de renda, meio de transporte aereo e maior a distancia do local de origem ao Pantanal, maiores os gastos preditos por viagem e por dia. O sucesso da pescaria esta mais altamente correlacionado com a idade e o nivel de escolaridade do pescador e, ao contrario do pensamento convencional, nao correlacionado com os gastos, experiencia anterior no local, ou uma paixao por pesca. Independente do sucesso na captura, cerca de 22% dos pescadores compraram peixes antes de retornar a sua regiao de origem. Os gastos diretos totais relacionados as visitas de principal razao para o pescador esportivo visitar o Pantanal sul e o ambiente natural unico e nao a pesca. Esta informacao tem relevancia para o desenvolvimento do turismo regional, para os esforcos de "marketing" e para os objetivos de administracao dos recursos naturais do Pantanal. Alem disso, aqueles motivados para visitar o Pantanal principalmente por turismo contemplativo (observar o ambiente natural e a vida selvagem), gastam significativamente mais nas viagens do que aqueles motivados primariamente pelo sucesso potencial da pescaria ou pelo lazer.bitstream/item/37574/1/CT24.pd

Decidability of the Monadic Shallow Linear First-Order Fragment with Straight Dismatching Constraints

The monadic shallow linear Horn fragment is well-known to be decidable and has many application, e.g., in security protocol analysis, tree automata, or abstraction refinement. It was a long standing open problem how to extend the fragment to the non-Horn case, preserving decidability, that would, e.g., enable to express non-determinism in protocols. We prove decidability of the non-Horn monadic shallow linear fragment via ordered resolution further extended with dismatching constraints and discuss some applications of the new decidable fragment.Comment: 29 pages, long version of CADE-26 pape

Tecnologias apropriadas para o desenvolvimento sustentado da bovinocultura de corte no Pantanal.

O sistema tradicional de producao; A cadeia produtiva da pecuaria de corte no Pantanal; Distribuicao e evolucao dos principais aspectos agropecuarios nas sub-regioes do Pantanal; Introducao de tecnologias na criacao de bovinos de corte no Pantanal.bitstream/item/37741/1/DOC24.pd

Forming and confining of dipolar excitons by quantizing magnetic fields

We show that a magnetic field perpendicular to an AlGaAs/GaAs coupled quantum well efficiently traps dipolar excitons and leads to the stabilization of the excitonic formation and confinement in the illumination area. Hereby, the density of dipolar excitons is remarkably enhanced up to $\sim 10^{11} cm^{-2}$. By means of Landau level spectroscopy we study the density of excess holes in the illuminated region. Depending on the excitation power and the applied electric field, the hole density can be tuned over one order of magnitude up to $\sim 2.5$ $10^{11} cm^{-2}$ - a value comparable with typical carrier densities in modulation-doped structures.Comment: 4.3 Pages, 4 Figure

Long exciton spin memory in coupled quantum wells

Spatially indirect excitons in a coupled quantum well structure were studied by means of polarization and time resolved photoluminescence. A strong degree of circular polarization (> 50%) in emission was achieved when the excitation energy was tuned into resonance with the direct exciton state. The indirect transition remained polarized several tens of nanoseconds after the pumping laser pulse, demonstrating directly a very long relaxation time of exciton spin. The observed spin memory effect exceeds the radiative lifetime of the indirect excitons.Comment: 4 pages, 2 figure

Irradiation of Materials with Short, Intense Ion pulses at NDCX-II

We present an overview of the performance of the Neutralized Drift Compression Experiment-II (NDCX-II) accelerator at Berkeley Lab, and report on recent target experiments on beam driven melting and transmission ion energy loss measurements with nanosecond and millimeter-scale ion beam pulses and thin tin foils. Bunches with around 10^11 ions, 1-mm radius, and 2-30 ns FWHM duration have been created with corresponding fluences in the range of 0.1 to 0.7 J/cm^2. To achieve these short pulse durations and mm-scale focal spot radii, the 1.1 MeV He+ ion beam is neutralized in a drift compression section, which removes the space charge defocusing effect during final compression and focusing. The beam space charge and drift compression techniques resemble necessary beam conditions and manipulations in heavy ion inertial fusion accelerators. Quantitative comparison of detailed particle-in-cell simulations with the experiment play an important role in optimizing accelerator performance.Comment: 15 pages, 7 figures. revised manuscript submitted to Laser and Particle Beam

Absorption and photoluminescence spectroscopy on a single self-assembled charge-tunable quantum dot

We have performed detailed photoluminescence (PL) and absorption spectroscopy on the same single self-assembled quantum dot in a charge-tunable device. The transition from neutral to charged exciton in the PL occurs at a more negative voltage than the corresponding transition in absorption. We have developed a model of the Coulomb blockade to account for this observation. At large negative bias, the absorption broadens as a result of electron and hole tunneling. We observe resonant features in this regime whenever the quantum dot hole level is resonant with two-dimensional hole states located at the capping layer-blocking barrier interface in our structure.Comment: 6 pages, 6 figure

Spin dependent fragmentation functions at Belle

The Belle detector at the KEKB e+e− collider provides large amounts of statistics to study the fragmentation of light quarks into final state hadrons. In addition to unpolarized fragmentation functions also spin dependent fragmentation can be studied. Belle has successfully extracted asymmetries related to the Collins and interference fagmentation functions for charged pions

Variation in hybrid gene expression: Implications for the evolution of genetic incompatibilities in interbreeding species

Interbreeding species often produce low-fitness hybrids due to genetic incompatibilities between parental genomes. Whether these incompatibilities reflect fixed allelic differences between hybridizing species, or, alternatively, standing variants that segregate within them, remains unknown for many natural systems. Yet, evaluating these alternatives is important for understanding the origins and nature of species boundaries. We examined these alternatives using spadefoot toads (genus Spea), which naturally hybridize. Specifically, we contrasted patterns of gene expression in hybrids relative to pure-species types in experimentally produced tadpoles from allopatric parents versus those from sympatric parents. We evaluated the prediction that segregating variation should result in gene expression differences between hybrids derived from sympatric parents versus hybrids derived from allopatric parents, and found that 24% of the transcriptome showed such differences. Our results further suggest that gene expression in hybrids has evolved in sympatry owing to evolutionary pressures associated with ongoing hybridization. Although we did not measure hybrid incompatibilities directly, we discuss the implications of our findings for understanding the nature of hybrid incompatibilities, how they might vary across populations over time, and the resulting effects on the evolutionary maintenance - or breakdown - of reproductive barriers between species