Federal University of Uberlandia

Uberlandia, Brazil

The Federal University of Uberlândia is an institution in the southwest of Minas Gerais, in Uberlândia, Brazil. It is a public university and does not charge any fees. The students are admitted through yearly exams, the vestibular.As of 2008, UFU offers 33 undergraduate degrees, including a sought-after Medicine degree, Law, Economics, plus Engineering, Science and Art degrees. It offers 10 PhD programs, 22 MSc programs, 34 diplomas and 21 medical residence programs. Wikipedia.

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dos Santos A.P.,Federal University of Uberlandia
Annals of botany | Year: 2012

Apomictic plants are less dependent on pollinator services and able to occupy more diverse habitats than sexual species. However, such assumptions are based on temperate species, and comparable evaluation for species-rich Neotropical taxa is lacking. In this context, the Melastomataceae is a predominantly Neotropical angiosperm family with many apomictic species, which is common in the Campos Rupestres, endemism-rich vegetation on rocky outcrops in central Brazil. In this study, the breeding system of some Campo Rupestre Melastomataceae was evaluated, and breeding system studies for New World species were surveyed to test the hypothesis that apomixis is associated with wide distributions, whilst sexual species have more restricted areas. The breeding systems of 20 Campo Rupestre Melastomataceae were studied using hand pollinations and pollen-tube growth analysis. In addition, breeding system information was compiled for 124 New World species of Melastomataceae with either wide (>1000 km) or restricted distributions. Most (80 %) of the Campo Rupestre species studied were self-compatible. Self-incompatibility in Microlicia viminalis was associated with pollen-tube arrest in the style, as described for other Melastomataceae, but most self-incompatible species analysed showed pollen-tube growth to the ovary irrespective of pollination treatment. Apomictic species showed lower pollen viability and were less frequent among the Campo Rupestre plants. Among the New World species compiled, 43 were apomictic and 77 sexual (24 self-incompatible and 53 self-compatible). Most apomictic (86 %) and self-incompatible species (71 %) presented wide distributions, whilst restricted distributions predominate only among the self-compatible ones (53 %). Self-compatibility and dependence on biotic pollination were characteristic of Campo Rupestre and narrowly distributed New World Melastomataceae species, whilst apomictics are widely distributed. This is, to a certain extent, similar to the geographical parthenogenesis pattern of temperate apomictics.

The two largest Atlantic Forest remnants in the state of Espírito Santo, eastern Brazil, namely 'Reserva Biológica de Sooretama' (REBIO Sooretama) and 'Reserva Natural Vale' (RNV), were surveyed for their orchid-bee faunas. Seventeen scent baits were used to attract orchid-bee males. Three-thousand, two hundred and twenty-five males belonging to 24 species were actively collected with insect nets during 100 hours in March, April and December, 2009. In comparison with a previous study in the same area twelve years before, it is evident that the abundance of all forest-dependent orchid bees analysed declined around 50%, and it was statistically significant (P = 0.022) for Euglossa marianae Nemésio, 2011, the most sensitive to anthropogenic disturbances of all Atlantic Forest orchid bees. On the other hand, the abundance of populations of species tolerant to open or disturbed areas rose. Possible explanations are discussed.

Heisenberg formulated a noise-disturbance principle stating that there is a tradeoff between noise and disturbance when a measurement of position and a measurement of momentum are performed sequentially, and another principle imposing a limitation on the product of the uncertainties in a joint measurement of position and momentum. We prove that the former, the Heisenberg sequential noise-disturbance principle, holds when the detectors are assumed to be initially uncorrelated from each other, but that it can be violated for some properly correlated initial preparations of the detectors. © 2013 American Physical Society.

Di Lorenzo A.,Federal University of Uberlandia
Physical Review Letters | Year: 2013

It is shown how it is possible to reconstruct the initial state of a one-dimensional system by sequentially measuring two conjugate variables. The procedure relies on the quasicharacteristic function, the Fourier transform of the Wigner quasiprobability. The proper characteristic function obtained by Fourier transforming the experimentally accessible joint probability of observing "position" then "momentum" (or vice versa) can be expressed as a product of the quasicharacteristic function of the two detectors and that unknown of the quantum system. This allows state reconstruction through the sequence (1) data collection, (2) Fourier transform, (3) algebraic operation, and (4) inverse Fourier transform. The strength of the measurement should be intermediate for the procedure to work. © 2013 American Physical Society.

Nemesio A.,Federal University of Uberlandia
Zootaxa | Year: 2011

Exaerete salsai sp. n. (Hymenoptera: Apidae: Apini: Euglossina) is described from southern Bahia and northeastern Minas Gerais, eastern Brazil. Its relationships with the other members of the genus are discussed, and it is considered to be a close ally of the Amazonian Exaerete trochanterica (Friese, 1900) and the Central American Exaerete kimseyae Oliveira, 2011. Copyright © 2011, Magnolia Press.

The orchid bee faunas of Floresta Nacional do Rio Preto, Reserva Biológica Córrego Grande, and Reserva Biológica Córrego do Veado, in the northernmost portion of the state of Espírito Santo, southeastern Brazil, were surveyed for orchid bees for the first time. A total of 1,603 males belonging to 24 species were attracted to 16 different scent baits and actively collected with insect nets during 100 hours from December, 2009, to February, 2010. One species of Euglossa, known as strongly dependent on well preserved mature forests, once recorded at the region, was not found in this survey and may indicate the first documented local extinction of an orchid bee species. This species, which Atlantic Forest population has been treated as Euglossa analis Westwood, 1840, is here considered a new species, Euglossa marianae sp. n. © 2011. Magnolia Press.

The orchid bee fauna of Parque Estadual da Serra do Conduru, in the state of Bahia, one of the largest remnants of Atlantic Rain Forest in northeastern Brazil, was surveyed for orchid bees for the first time. Six hundred and twenty-two males belonging to 20 species were actively collected with insect nets during 40 hours from the 26th to the 31st of January, 2010. Euglossa cyanochlora Moure, 1996 - a very rare species previously known only from the type locality - was found, the northernmost record for this species in the Atlantic Forest domain. Euglossa viridis (Perty, 1833) and Euglossa amazonica Dressler, 1982, this latter species recently recorded for the state of Alagoas, are also reported for the first time in the state of Bahia. An identification key for all species recorded in the area is also provided.

Wrasse E.O.,Federal University of Uberlandia | Schmidt T.M.,Federal University of Uberlandia
Nano Letters | Year: 2014

Two-dimensional (2D) topological crystalline insulator, a new class where states are protected by lattice symmetry instead of by time-reversal symmetry, is predicted in PbSe monolayer based on first-principles electronic structure calculations. A combination of strong spin-orbit interaction with quantum confinement effects in PbSe monolayer lead to a topological phase transition with an even number of band inversion momentum space points. We demonstrate that the PbSe nanostructure presents pairs of spin-polarized Dirac cones coming from the monolayer edges, where each Dirac pair presents a unique spin alignment, leading to a quantum spin Hall system. More importantly, due to the quantum confinement this 2D nanostructure presents larger band gap as compared to its parent narrow band gap trivial insulator bulk PbSe, favoring a room-temperature 2D band gap with crystalline-protected Dirac states at the edges, turning this system interesting to combine nontrivial topological states with nanoelectronic and spintronic applications. © 2014 American Chemical Society.

Di Lorenzo A.,Federal University of Uberlandia
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

The results are shown to be incorrect by means of a counterexample, an explicit preparation for the probe is given that yields an arbitrary amplification, and the source of the error is pointed out. © 2013 American Physical Society.

Backes A.R.,Federal University of Uberlandia
Pattern Recognition Letters | Year: 2013

A new approach is proposed based on gliding-box method to estimate the lacunaritys of texture images. The first approach uses a local threshold to enhance local features of the texture pattern, so that, lacunarity is computed in terms of the local binary patterns that exist in the image, a characteristic which is proven to be a very powerful texture feature. The second approach simply expands the concept of gliding a box over the gray level intensity axis of the texture. As this task is a very time consuming one, we present an algorithm to speed up this process. The results have been tested in a natural texture database, a real and complex problem because the high variability intra-class and great similarity between classes, and compared with traditional lacunarity approaches to show that this new method is computationally simple, convenient and accurate. © 2013 Elsevier B.V. All rights reserved.

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