Clock-Driven Quantum Thermal Engines

We consider an isolated autonomous quantum machine, where an explicit quantum clock is responsible for performing all transformations on an arbitrary quantum system (the engine), via a time-independent Hamiltonian. In a general context, we show that this model can exactly implement any energy-conserving unitary on the engine, without degrading the clock. Furthermore, we show that when the engine includes a quantum work storage device we can approximately perform completely general unitaries on the remainder of the engine. This framework can be used in quantum thermodynamics to carry out arbitrary transformations of a system, with accuracy and extracted work as close to optimal as desired, whilst obeying the first and second laws of thermodynamics. We thus show that autonomous thermal machines suffer no intrinsic thermodynamic cost compared to externally controlled ones.Comment: 6 pages, 1 Appendix page, 2 figure

Estudo estrutural e funcional do gene VvAGL11 e seu papel na morfogênese de sementes de Vitis vinifera.

O objetivo deste trabalho foi caracterizar estruturalmente a sequência codificadora de VvAGL11 e avaliar sua funcionalidade na morfogênese de sementes, por meio da complementação do mutante 'Seedstick' (stk) de Arabidopsis thaliana

Caracterização do perfil transcricional de genes associados à estenoespermocarpia em videira (Vitis vinifera L.).

O objetivo deste trabalho foi caracterizar o perfil transcricional de dois genes candidatos associados à estenoespermocarpia em cultivares com semente (Chardonnay) e com traços de semente (Sultanina) em diferentes estádios de desenvolvimento do fruto.Resumo

Riverine habitat specificity constrains dispersion in a Neotropical fish (Characidae) along Southern Brazilian drainages

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111903/1/zsc12106.pd

Evidence for GABA-induced systemic GABA accumulation in Arabidopsis upon wounding

The non-proteinogenic amino acid γ-aminobutyric acid (GABA) is present in all plant species analyzed so far. Its synthesis is stimulated by either acidic conditions occurring after tissue disruption or higher cytosolic calcium level. In mammals, GABA acts as inhibitory neurotransmitter but its function in plants is still not well understood. Besides its involvement in abiotic stress resistance, GABA has a role in the jasmonate-independent defense against invertebrate pests. While the biochemical basis for GABA accumulation in wounded leaves is obvious, the underlying mechanisms for wounding-induced GABA accumulation in systemic leaves remained unclear. Here, the Arabidopsis thaliana knock-out mutant lines pop2-5, unable to degrade GABA, and tpc1-2, lacking a wounding-induced systemic cytosolic calcium elevation, were employed for a comprehensive investigation of systemic GABA accumulation. A wounding-induced systemic GABA accumulation was detected in tpc1-2 plants demonstrating that an increased calcium level was not involved. Similarly, after both mechanical wounding and Spodoptera littoralis feeding, GABA accumulation in pop2-5 plants was significantly higher in local and systemic leaves, compared to wild-type plants. Consequently, larvae feeding on these GABA-enriched mutant plants grew significantly less. Upon exogenous application of a D2-labeled GABA to wounded leaves of pop2-5 plants, its uptake but no translocation to unwounded leaves was detected. In contrast, an accumulation of endogenous GABA was observed in vascular connected systemic leaves. These results suggest that the systemic accumulation of GABA upon wounding does not depend on the translocation of GABA or on an increase in cytosolic calcium

Gene expression analysis of VVAG3 in grapevine reproductive tissues by in situ hybridization.

Resumo

Quantum Systems Equilibrate Rapidly for Most Observables

Considering any Hamiltonian, any initial state, and measurements with a small number of possible outcomes compared to the dimension, we show that most measurements are already equilibrated. To investigate non-trivial equilibration we therefore consider a restricted set of measurements. When the initial state is spread over many energy levels, and we consider the set of observables for which this state is an eigenstate, most observables are initially out of equilibrium yet equilibrate rapidly. Moreover, all two-outcome measurements, where one of the projectors is of low rank, equilibrate rapidly.Comment: Main Text: 5 pages, 1 figure. Appendices: 7 pages, 1 figur