Skills Training in Laboratory and Clerkship: Connections, Similarities, and Differences

Context: During the third semester of a 6 year long curriculum medical students train clinical skills in the skills laboratory (2 hours per week for 9 weeks) as well as in an early, 8 week clinical clerkship at county hospitals. Objectives: to study students’ expectations and attitudes towards skills training in the skills laboratory and clerkship. Subjects: 126 medical students in their 3rd semester. Methods: During the fall of 2001 three consecutive, constructed questionnaires were distributed prior to laboratory training, following laboratory training but prior to clerkships, and following clerkships respectively. Results: Almost all (98%) respondents found that training in skills laboratory improved the outcome of the early clerkship and 70% believed in transferability of skills from the laboratory setting to clerkship. Still, a majority (93%) of students thought that the clerkship provided students with a better opportunity to learn clinical skills when compared to the skills laboratory. Skills training in laboratory as well as in clerkship motivated students for becoming doctors. Teachers in both settings were perceived as being committed to their teaching jobs, to demonstrate skills prior to practice, and to give students feed back with a small but significant more positive rating of the laboratory. Of the 22 skills that students had trained in the laboratory, a majority of students tried out skills associated with physical examination in the clerkship, whereas only a minority of students tried out more intimate skills. Female medical students tried significantly fewer skills during their clerkship compared to male students. Conclusions: Students believe that skills laboratory training prepare them for their subsequent early clerkship but favour the clerkship over the laboratory

Topologica Defects and Corrections to the Nambu Action

The effective action of a (1+2)-dimensional defect is obtained as an expansion in powers of the thickness.Considering non-straight solutions as the zero order term, the corrections to the Nambu action are found to depend on the curvature scalar and on the gaussian curvature .Comment: UNB.FIS.FM-002/92, Marcos@FNAL, 12 pages, Late

Single-mode photonic crystal fiber with an effective area of 600 square-micron and low bending loss

A single-mode all-silica photonic crystal fiber with an effective area of 600 square-micron and low bending loss is demonstrated. The fiber is characterized in terms of attenuation, chromatic dispersion and modal properties.Comment: 10 pages including 3 figures. Accepted for Electronics Letter

An entropic uncertainty principle for positive operator valued measures

Extending a recent result by Frank and Lieb, we show an entropic uncertainty principle for mixed states in a Hilbert space relatively to pairs of positive operator valued measures that are independent in some sense. This yields spatial-spectral uncertainty principles and log-Sobolev inequalities for invariant operators on homogeneous spaces, which are sharp in the compact case.Comment: 14 pages. v2: a technical assumption removed in main resul

Reconstruction of superoperators from incomplete measurements

We present strategies how to reconstruct (estimate) properties of a quantum channel described by the map E based on incomplete measurements. In a particular case of a qubit channel a complete reconstruction of the map E can be performed via complete tomography of four output states E[rho_j ] that originate from a set of four linearly independent test states j (j = 1, 2, 3, 4) at the input of the channel. We study the situation when less than four linearly independent states are transmitted via the channel and measured at the output. We present strategies how to reconstruct the channel when just one, two or three states are transmitted via the channel. In particular, we show that if just one state is transmitted via the channel then the best reconstruction can be achieved when this state is a total mixture described by the density operator rho = I/2. To improve the reconstruction procedure one has to send via the channel more states. The best strategy is to complement the total mixture with pure states that are mutually orthogonal in the sense of the Bloch-sphere representation. We show that unitary transformations (channels) can be uniquely reconstructed (determined) based on the information of how three properly chosen input states are transformed under the action of the channel.Comment: 13 pages, 6 figure

Minimal measurements of the gate fidelity of a qudit map

We obtain a simple formula for the average gate fidelity of a linear map acting on qudits. It is given in terms of minimal sets of pure state preparations alone, which may be interesting from the experimental point of view. These preparations can be seen as the outcomes of certain minimal positive operator valued measures. The connection of our results with these generalized measurements is briefly discussed

Experimental implementation of a NMR entanglement witness

Entanglement witnesses (EW) allow the detection of entanglement in a quantum system, from the measurement of some few observables. They do not require the complete determination of the quantum state, which is regarded as a main advantage. On this paper it is experimentally analyzed an entanglement witness recently proposed in the context of Nuclear Magnetic Resonance (NMR) experiments to test it in some Bell-diagonal states. We also propose some optimal entanglement witness for Bell-diagonal states. The efficiency of the two types of EW's are compared to a measure of entanglement with tomographic cost, the generalized robustness of entanglement. It is used a GRAPE algorithm to produce an entangled state which is out of the detection region of the EW for Bell-diagonal states. Upon relaxation, the results show that there is a region in which both EW fails, whereas the generalized robustness still shows entanglement, but with the entanglement witness proposed here with a better performance

Demonstrating various quantum effects with two entangled laser beams

We report on the preparation of entangled two mode squeezed states of yet unseen quality. Based on a measurement of the covariance matrix we found a violation of the Reid and Drummond EPR-criterion at a value of only 0.36\pm0.03 compared to the threshold of 1. Furthermore, quantum state tomography was used to extract a single photon Fock state solely based on homodyne detection, demonstrating the strong quantum features of this pair of laser-beams. The probability for a single photon in this ensemble measurement exceeded 2/3