Fitness of antibiotic-resistant bacteria in the environment: a laboratory activity

In this laboratory experiment, we propose an opportunity for students to broaden their understanding of the ecology of antibiotic-resistant and sensitive waterborne bacteria. Antibiotics can be found in rivers or soil as a consequence of agricultural practices or as a result of human use. Concentrations of antibiotics in the environment may range from a few ng to μg L-1. Such concentrations can affect the selection and fitness of resistant bacteria. In this laboratory activity, students learn how to set up a fitness experiment by using an isogenic pair of antibiotic-resistant and sensitive bacteria in the presence or absence of selective pressure. Microcosms were generated by using filtered river water containing populations of resistant and sensitive bacteria. Competition of both populations was measured in the presence or absence of antibiotics. Students appreciated the use of microcosms for in vitro experiments and the extent to which the fitness of resistant and sensitive bacteria changed in the presence and/or absence of a selective pressure in river water. Student learning was measured by using different types of assessments: multiple-choice, true/false, fill in the blanks, laboratory skills observations, and laboratory reports. After the laboratory activity, the percentage of correct answers significantly rose from ~20% to ~85%. Laboratory skills were also evaluated during the exercises, showing no major issues during the experiment. Students showed proficiency in analyzing the complexity of fitness data by reaching a mean of 5.57 (standard error 0.57) over a maximum score of 7 points

Plasmid profile, antibiotic resistance, and phenotypic virulent strains of S. flexneri

Shigellosis is an acute gastroenteritis caused by Shigella species. The purpose of this study was to determine plasmid profile, antibiotic resistance and phenotypic virulent by Congo red between S. flexneri strains. The isolated bacteria were identified by standard bacterial and biochemical methods. Plasmids were isolated by alkaline lysis method. Antibiotic susceptibility test was performed according to "kirby-Bauer" method. Serological reactions were carried by slide agglutination tests with both polyclonal and monoclonal antiserum kits. Virulent strains were isolated on a TSA plate contained Congo red dye concentration. From 350 isolated Shigella species, 142 (40.57) were S. flexneri. Eleven distinct plasmid profile patterns were identified. Of S. flexneri isolates, 95 were resistant to tetracycline, 85.6 to SXT and 75.3 to ampicillin. All the isolates were sensitive to ciprofloxacin. Our results showed that 39 were serotype II. 45.56 of S. flexneri were Congo red positive. Antibiotic resistant determination in each case may prevent drug resistance increase. Since Congo red binding test is cheap and simple it can be used to determine virulence properties of S. flexneri

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

Optimizing entangling quantum gates for physical systems

Optimal control theory is a versatile tool that presents a route to significantly improving figures of merit for quantum information tasks. We combine it here with the geometric theory for local equivalence classes of two-qubit operations to derive an optimization algorithm that determines the best entangling two-qubit gate for a given physical setting. We demonstrate the power of this approach for trapped polar molecules and neutral atoms.Comment: extended version; Phys. Rev. A (2011

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

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

Exact two-qubit universal quantum circuit

We provide an analytic way to implement any arbitrary two-qubit unitary operation, given an entangling two-qubit gate together with local gates. This is shown to provide explicit construction of a universal quantum circuit that exactly simulates arbitrary two-qubit operations in SU(4). Each block in this circuit is given in a closed form solution. We also provide a uniform upper bound of the applications of the given entangling gates, and find that exactly half of all the Controlled-Unitary gates satisfy the same upper bound as the CNOT gate. These results allow for the efficient implementation of operations in SU(4) required for both quantum computation and quantum simulation.Comment: 5 page