Nucleosynthesis in the early history of the solar system

Nucleosynthesis in early history of solar syste

On a Tree and a Path with no Geometric Simultaneous Embedding

Two graphs $G_1=(V,E_1)$ and $G_2=(V,E_2)$ admit a geometric simultaneous embedding if there exists a set of points P and a bijection M: P -> V that induce planar straight-line embeddings both for $G_1$ and for $G_2$. While it is known that two caterpillars always admit a geometric simultaneous embedding and that two trees not always admit one, the question about a tree and a path is still open and is often regarded as the most prominent open problem in this area. We answer this question in the negative by providing a counterexample. Additionally, since the counterexample uses disjoint edge sets for the two graphs, we also negatively answer another open question, that is, whether it is possible to simultaneously embed two edge-disjoint trees. As a final result, we study the same problem when some constraints on the tree are imposed. Namely, we show that a tree of depth 2 and a path always admit a geometric simultaneous embedding. In fact, such a strong constraint is not so far from closing the gap with the instances not admitting any solution, as the tree used in our counterexample has depth 4.Comment: 42 pages, 33 figure

A scalable, high-speed measurement-based quantum computer using trapped ions

We describe a scalable, high-speed, and robust architecture for measurement-based quantum-computing with trapped ions. Measurement-based architectures offer a way to speed-up operation of a quantum computer significantly by parallelizing the slow entangling operations and transferring the speed requirement to fast measurement of qubits. We show that a 3D cluster state suitable for fault-tolerant measurement-based quantum computing can be implemented on a 2D array of ion traps. We propose the projective measurement of ions via multi-photon photoionization for nanosecond operation and discuss the viability of such a scheme for Ca ions.Comment: 4 pages, 3 figure

Radiosensitizing and cytocidal effects on hypoxic cells of RO-07-0582, and repair of x-ray injury, in an experimental mouse tumour.

The delay in regrowth to 10 mm diameter of a transplanted carcinoma in mice was used to estimate the effect of the hypoxic-cell radiosensitizer Ro-07-0582. When 1 mg/g body wt. was given before a single dose of X-rays, a dose-enhancement ratio of 2-0 was found. When the drug was given immediately after irradiation, a large cytotoxic effect was observed, equivalent to an enhancement ratio of 1-3. These results were confirmed by determining the X-ray doses required for the local control of 50% of the tumours at 80 days after irradiation. The capacity of the tumour for repair of sublethal X-ray injury within 24 h was similar to that for several normal tissues

Architectural/Environmental Handbook for Extraterrestrial Design

Handbook on environmental and space utilization criteria for design of extraterrestrial manned spacecraft and shelter

Trajectory-Based Dynamic Map Labeling

In this paper we introduce trajectory-based labeling, a new variant of dynamic map labeling, where a movement trajectory for the map viewport is given. We define a general labeling model and study the active range maximization problem in this model. The problem is NP-complete and W[1]-hard. In the restricted, yet practically relevant case that no more than k labels can be active at any time, we give polynomial-time algorithms. For the general case we present a practical ILP formulation with an experimental evaluation as well as approximation algorithms.Comment: 19 pages, 7 figures, extended version of a paper to appear at ISAAC 201

The Maxwell-Bloch Theory in Quantum Optics and the Kondo Model

In this letter, the problem of radiation in a fiber geometry interacting with a two level atom is mapped onto the anisotropic Kondo model. Thermodynamical and dynamical properties are then computed exploiting the integrability of this latter system. We compute some correlation functions, decay rates and Lamb shifts. In turn this leads to an analysis of the classical limit of the anisotropic Kondo model.Comment: 4 pages, 1 figure. In Latex. Uses Revte

Efeitos de tratamentos pré-germinativos e germinativos em sementes de Liquidambar styraciflua l. coletadas em Quedas do Iguaçu, PR.

Resumo

Variability Flagging in the Wide-field Infrared Survey Explorer Preliminary Data Release

The Wide-field Infrared Survey Explorer Preliminary Data Release Source Catalog contains over 257 million objects. We describe the method used to flag variable source candidates in the Catalog. Using a method based on the chi-square of single-exposure flux measurements, we generated a variability flag for each object, and have identified almost 460,000 candidate sources that exhibit significant flux variability with greater than ~7σ confidence. We discuss the flagging method in detail and describe its benefits and limitations. We also present results from the flagging method, including example light curves of several types of variable sources including Algol-type eclipsing binaries, RR Lyr, W UMa, and a blazar candidate