Perfect initialization of a quantum computer of neutral atoms in an optical lattice of large lattice constant

We propose a scheme for the initialization of a quantum computer based on neutral atoms trapped in an optical lattice with large lattice constant. Our focus is the development of a compacting scheme to prepare a perfect optical lattice of simple orthorhombic structure with unit occupancy. Compacting is accomplished by sequential application of two types of operations: a flip operator that changes the internal state of the atoms, and a shift operator that moves them along the lattice principal axis. We propose physical mechanisms for realization of these operations and we study the effects of motional heating of the atoms. We carry out an analysis of the complexity of the compacting scheme and show that it scales linearly with the number of lattice sites per row of the lattice, thus showing good scaling behavior with the size of the quantum computer.Comment: 18 page

Canine mastocytosis

Mastocytosis is a mast cell disorder in which its exaggerated proliferation can occur in two forms: systemic and cutaneous (Davis et al., 1992). Because canine mastocytosis is a rare situation of controversial and difficult diagnosis, the goal of this study consists in a current revision of this subject, in order to sensitize the veterinary staff to its severity, with particular focus on the information the veterinary nurse must hold to better apply a specialized nursing care with the high professionalismFCT/CI&DETS (PEst-OE/CED/UI4016/2011

Thymic Squamous Cell Carcinoma? Do you confirm this diagnosis?

Introduction In dogs thymic carcinoma is considered rare and distinguishes itself from thymoma by its cytologically malignant features, extensive local invasion, and a substantial potential for metastasis. Surgical excision is the treatment of choice for most thymic tumours, with the exception of lymphoma. Medical History A 9 years old cross-breed male dog was presented due to cough and respiratory distress with duration of 4 weeks. The animal presented with inspiratory dyspnea and cyanosis. A mass, dorsal to the pharynx, was diagnosed after clinical and radiographical examination, suspected of thyroid neoplasia. Cytology was performed and revealed cells consistent with malignancy, apparently carcinoma with high parameters of aggressiveness. As a form of treatment and to obtain a definitive diagnosis, was decided to surgical removed the mass which measured 7.8x3.7x3.5cm. Material and Methods The sample was fixed in 10 % buffered formalin solution for histological evaluation and sent to the Anatomic Pathology Laboratory of the Agrarian Superior School of Viseu, in Portugal, for histological evaluation. Results Microscopic examination revealed that we were in presence of a lymphoid organ, with peculiar features, namely a small to intermediate-sized lymphoid cells, "starry-sky" pattern and rounded eosinophilic perivascular arrangements resembling Hassall's corpuscles. Concomitantly, typical features of squamous cell carcinoma were evident. Discussion and Conclusion In conclusion, based on its histological features, the authors suggested the diagnosis of Thymic Squamous Cell Carcinoma with an unusual location. Thymic tumours in dogs are predominantly located in the anterior mediastinum but they may extend from the neck to the posterior mediastinum.This work was supported by Portuguese Foundation for Science and Technology, Center for Studies in Education, Technologies and by Health and by strategic project PEst-OE/CED/UI4016/201

Lombar Tranverse Process Osteosarcoma

Introduction Osteosarcoma (OSA) is the most common primary bone tumor in dogs. Between 20 and 25% of canine OSA arise from bones of the axial skeleton and are also the most common extradural spinal neoplasm (46%). Radiographic appearance is nonspecific and inconsistent. Pain without neurological signs is the predominant initial finding with vertebral OSA. Materials and Methods A 8 years cross-bred male dog was presented for consultation complaining of progressive weight loss, apathy and nonspecific pain. A paralumbar mass on the left side was diagnosed after clinical and radiographical examination. Cytology of the mass was performed and the animal was hospitalized for pain control and nutritional support until definitive diagnosis. During hospitalization, the clinical status of the animal deteriorated emerging neurological abnormalities. The cytology revealed the presence of cells characteristic of a neoplastic process of mesenchymal origin, apparently sarcoma. It was decided to perform a myelogram wich revealed spinal cord compression at L4, caused by the mass. Due to the deterioration of clinical status and the diagnosis owners decided for euthanasia. Results At necropsy was observedthe thickening of the transverse process of L4 vertebra by a mass with 6.3 x 7.0 x 4.5 cm. The histopathological diagnosis revealed an OSA with different histologic aspects. Discussion and Conclusion An unsucessful outcome OSA was diagnosed. Aadequately treatinglocal disease ofvertebral OSA is very difficult. Surgery is an attempt to decompress dogs with neurologic deficits or intractable pain. Present recommendations are to perform surgery for decompression and institute radiation and chemotherapy.This work was supported by Portuguese Foundation for Science and Technology, Center for Studies in Education, Technologies and by Health and by strategic project PEst-OE/CED/UI4016/201

Minimum construction of two-qubit quantum operations

Optimal construction of quantum operations is a fundamental problem in the realization of quantum computation. We here introduce a newly discovered quantum gate, B, that can implement any arbitrary two-qubit quantum operation with minimal number of both two- and single-qubit gates. We show this by giving an analytic circuit that implements a generic nonlocal two-qubit operation from just two applications of the B gate. We also demonstrate that for the highly scalable Josephson junction charge qubits, the B gate is also more easily and quickly generated than the CNOT gate for physically feasible parameters.Comment: 4 page

Inverted papilloma in Russian Hamster

Introduction: Cutaneous papilloma is a benign epithelial neoplasm arising in epidermal keratinocytes. Papillomaviruses belong to papovavirus family, causing single or multiple verrucous projections, variable in size, well circumscribed and keratinized. This type of tumour is common in horses, cattle and humans; less frequent in dogs and goats and rare in sheep, pigs, cats, guinea pigs and hamsters. Medical History: A 1-and a half year old entire Russian hamster was presented with a right lateral axilar subcutaneous ulcerated nodule. No other abnormalities were detected on clinical examination. The approach taken was total surgical excision. Material and Methods: The samples were fixed in 10 % buffered formalin solution for histological evaluation and were sent to the Anatomic Pathology Laboratory of the Agrarian Superior School of Viseu, in Portugal. Results: Macroscopically, the cut section revealed whitish tissues with radiated aspect, converging on the ulcerated area. Microscopic examination revealed a cystic cavity, lined by hiperplasic squamous epithelium, apparently inverted, with ortho and parakeratotic hyperkeratosis, presenting peniforme pattern. The epithelium showed acanthosis, hypergranulosis, with very large keratohyalin granules. Koilocytosis was also observed, as well as sparse eosinophilic intracytoplasmic bodies, in the cells with ballooning degeneration. Discussion and Conclusion: The histopathological features observed were compatible with the diagnosis of papilloma. However, the uncharacteristic inverted image of the epithelium, producing keratin convergent to the cystic cavity, which acquired a peniforme appearance, would fit the descriptions of inverted papilloma, although, apparently, this type of tumor, especially of such large dimensions, never been described in the hamster.This work was supported by Portuguese Foundation for Science and Technology, Center for Studies in Education, Technologies and by Health and by strategic project PEst-OE/CED/UI4016/201

Nonlocality as a Benchmark for Universal Quantum Computation in Ising Anyon Topological Quantum Computers

An obstacle affecting any proposal for a topological quantum computer based on Ising anyons is that quasiparticle braiding can only implement a finite (non-universal) set of quantum operations. The computational power of this restricted set of operations (often called stabilizer operations) has been studied in quantum information theory, and it is known that no quantum-computational advantage can be obtained without the help of an additional non-stabilizer operation. Similarly, a bipartite two-qubit system based on Ising anyons cannot exhibit non-locality (in the sense of violating a Bell inequality) when only topologically protected stabilizer operations are performed. To produce correlations that cannot be described by a local hidden variable model again requires the use of a non-stabilizer operation. Using geometric techniques, we relate the sets of operations that enable universal quantum computing (UQC) with those that enable violation of a Bell inequality. Motivated by the fact that non-stabilizer operations are expected to be highly imperfect, our aim is to provide a benchmark for identifying UQC-enabling operations that is both experimentally practical and conceptually simple. We show that any (noisy) single-qubit non-stabilizer operation that, together with perfect stabilizer operations, enables violation of the simplest two-qubit Bell inequality can also be used to enable UQC. This benchmarking requires finding the expectation values of two distinct Pauli measurements on each qubit of a bipartite system.Comment: 12 pages, 2 figure

A comparison of approaches to the prediction of surface wave amplitude

A controlled experiment is performed to investigate how assumptions and simplifications in the measurement and analysis of surface wave amplitudes affect inferred attenuation variations in the mantle. Synthetic seismograms are generated using a spectral-element method for 42 earthquakes, 134 receiver locations and two earth models, both of which contain 3-D elastic properties and 1-D anelastic properties. Fundamental-mode Rayleigh-wave amplitudes are measured at periods of 50, 75 and 125 s for 4749 paths. The amplitudes are measured with respect to a reference waveform based on 1-D Earth structure, and thus amplitude observations that are not equal to unity can be attributed to differences in the computation of the spectral-element and reference waveforms or to uncertainties in the amplitude measurements themselves. Calculation of earthquake source excitation in the 3-D earth model versus the 1-D earth model has a significant effect on the amplitudes, especially at shorter periods, and variations in the average amplitude for each event are well explained by the effect of Earth structure at the event location on the source excitation. The effect of local Earth structure at the receiver location on the amplitude is, for most paths, much smaller than for the source amplitude. After correcting for source and receiver effects on amplitude, the remaining signal is compared to predictions of elastic focusing effects using the great-circle ray approximation, exact ray theory (ERT) and finite-frequency theory (FFT). We find that, for the earth models we have tested, ERT provides the best fit at 50 s, and FFT is most successful at 75 and 125 s, indicating that the broad zone of surface wave sensitivity cannot be neglected for the longer periods in our experiment. The bias introduced into attenuation models by focusing effects, which is assessed by inverting the measured amplitudes for 2-D attenuation maps, is most important at high spherical-harmonic degrees. Unaccounted-for scattering of seismic energy may slightly (<5 per cent) raise average global attenuation values at short periods but has no detectable effect at longer periods. The findings of this study also provide a set of guidelines for handling source, receiver and focusing effects that can be applied to surface wave amplitudes measured for the real Earth

Mapping European social psychology: co-word analysis of the communications at the 10th General Meeting of the EAESP

This study aims to provide a picture of the present European research topics in Social Psychology, using the 339 papers presented at the 1993 General Meeting of the EAESP. The most frequent themes of research are analysed and the structure of the association of those themes are described in a two-factor structure. The first factor differentiates research in terms of level of analysis and the second factor contrasts types of applied research

Topological Degeneracy and Vortex Manipulation in Kitaev's Honeycomb Model

The classification of loop symmetries in Kitaev's honeycomb lattice model provides a natural framework to study the Abelian topological degeneracy. We derive a perturbative low-energy effective Hamiltonian that is valid to all orders of the expansion and for all possible toroidal configurations. Using this form we demonstrate at what order the system's topological degeneracy is lifted by finite size effects and note that in the thermodynamic limit it is robust to all orders. Further, we demonstrate that the loop symmetries themselves correspond to the creation, propagation, and annihilation of fermions. We note that these fermions, made from pairs of vortices, can be moved with no additional energy cost