Photonic multipartite entanglement conversion using nonlocal operations

We propose a simple setup for the conversion of multipartite entangled states in a quantum network with restricted access. The scheme uses nonlocal operations to enable the preparation of states that are inequivalent under local operations and classical communication, but most importantly does not require full access to the states. It is based on a flexible linear optical conversion gate that uses photons, which are ideally suited for distributed quantum computation and quantum communication in extended networks. In order to show the basic working principles of the gate, we focus on converting a four-qubit entangled cluster state to other locally inequivalent four-qubit states, such as the GHZ and symmetric Dicke state. We also show how the gate can be incorporated into extended graph state networks, and can be used to generate variable entanglement and quantum correlations without entanglement but nonvanishing quantum discord.Comment: 10 pages, 6 figures, correction of reference list, add Journal ref. and DO

Observation of quantum interference in the plasmonic Hong-Ou-Mandel effect

We report direct evidence of the bosonic nature of surface plasmon polaritons (SPPs) in a scattering-based beamsplitter. A parametric down-conversion source is used to produce two indistinguishable photons, each of which is converted into a SPP on a metal-stripe waveguide and then made to interact through a semi-transparent Bragg mirror. In this plasmonic analog of the Hong-Ou-Mandel experiment, we measure a coincidence dip with a visibility of 72%, a key signature that SPPs are bosons and that quantum interference is clearly involved.Comment: 5 pages, 3 figure

Quantum random number generation using an on-chip nanowire plasmonic waveguide

Quantum random number generators employ the inherent randomness of quantum mechanics to generate truly unpredictable random numbers, which are essential in cryptographic applications. While a great variety of quantum random number generators have been realised using photonics, few exploit the high-field confinement offered by plasmonics, which enables device footprints an order of magnitude smaller in size. Here we integrate an on-chip nanowire plasmonic waveguide into an optical time-of-arrival based quantum random number generation setup. Despite loss, we achieve a random number generation rate of 14.4 Mbits/s using low light intensity, with the generated bits passing industry standard tests without post-processing. By increasing the light intensity, we were then able to increase the generation rate to 41.4 Mbits/s, with the resulting bits only requiring a shuffle to pass all tests. This is an order of magnitude increase in the generation rate and decrease in the device size compared to previous work. Our experiment demonstrates the successful integration of an on-chip nanoscale plasmonic component into a quantum random number generation setup. This may lead to new opportunities in compact and scalable quantum random number generation.Comment: 10 pages, 3 figures, appendi

Subgross and macroscopic investigation of the coeliac artery in the chinchilla (chinchilla lanigera)

The knowledge of branching and variations of the coeliac artery is clinicallyimportant, especially in the surgical operations and non-surgical treatments.Moreover, the chinchillas abdominal region have been used as a model in somesurgical experimental researches. In this frame, we have aimed to explain thebranching of this artery in the chinchillas detailedly. A total of 10 adult, healthy,male chinchillas (chinchilla lanigera) were used to investigate the origin and thecourse of the coeliac artery and its branches. Coloured latex was injected intothe carotid arteries, following conventional anatomical applications. The resultsindicated that the coeliac artery was divided into 4 branches such as left gastricartery, hepatic artery, splenic artery and gastrolienal artery. The left gastric arterywas a continuity of the coeliac artery and the main vessel of the stomach. Thehepatic artery was divided into the left lateral branch, the left medial branch andthe right branch. The splenic artery was covered by the pancreas tissue and sentbranches to the pancreas. The gastrolienal artery was supplying the fundus ofthe stomach and the dorsal extremity of the spleen. We believe that the findingswill be of help to the researchers interested in the anatomical area, surgeons andexperimental researches

The prevalence of asthma and allergy among university freshmen in Eskisehir, Turkey

AbstractThe aim of this study was to determine the current and cumulative prevalence of asthma, allergic rhinitis, atopic dermatitis and reactivities to allergen skin prick tests (SPT) among university freshmen.The data at the first stage were collated through the application of the European Community Respiratory Health Survey (-ECRHS- Stage I) questionnaire on 1603 students registering at various faculties and vocational colleges of Osmangazi University in Eskisehir, Turkey, in the academic year 1997–1998. At the second stage a physical examination as well as allergen SPTs were conducted on 151 students.Of the students within the study group, six (0·4%) had experienced an asthma attack within the previous 12 months, 11 (0·7%) had a past of asthma attacks and 123 (8·1%) reported wheezing attacks within the previous 12 months. The prevalence of asthma-like symptoms, rhinoconjunctivitis and dermatitis were found to be 17·0%, 10·0% and 5·9% respectively. Asthma and asthma-like symptoms were found to be significantly more prevalent among students who smoked. A positive SPT reaction to more than one allergen was found in 14·6% of the students. SPT positivity was 8·3% in asymptomatic students, 27·3% in asthmatic students, 14·5% in those with asthma-like symptoms, 28% in those with non-infectious rhinitis and 7·1% in those with dermatitis. In analysis of logistic regression, a history of atopy, as ascertained in the questionnaire, was seen to have a significant effect on SPT positivity.The rate of self-reported asthma and/or asthma-like symptoms among newly enrolled freshmen at the Osmangazi University was found to be lower than in other countries. Cigarette smoking was seen to increase such symptoms significantly, in comparison to non-smokers

One-way quantum computing in a decoherence-free subspace

We introduce a novel scheme for one-way quantum computing (QC) based on the use of information encoded qubits in an effective cluster state resource. With the correct encoding structure, we show that it is possible to protect the entangled resource from phase damping decoherence, where the effective cluster state can be described as residing in a Decoherence-Free Subspace (DFS) of its supporting quantum system. One-way QC then requires either single or two-qubit adaptive measurements. As an example where this proposal can be realized, we describe an optical lattice setup where the scheme provides robust quantum information processing. We also outline how one can adapt the model to provide protection from other types of decoherence.Comment: 9 pages, 4 figures, RevTeX

An Analysis of the Quantum Penny Flip Game using Geometric Algebra

We analyze the quantum penny flip game using geometric algebra and so determine all possible unitary transformations which enable the player Q to implement a winning strategy. Geometric algebra provides a clear visual picture of the quantum game and its strategies, as well as providing a simple and direct derivation of the winning transformation, which we demonstrate can be parametrized by two angles. For comparison we derive the same general winning strategy by conventional means using density matrices.Comment: 8 Pages, 1 Figure, accepted for publication in the Journal of Physical Society of Japa

A cadaveric histological investigation of the prostate with three-dimensional reconstruction for better results in continence and erectile function after radical prostatectomy

In this study our aim is to increase the understanding of the prostate and related organs anatomy for better continence and erectile function results after urological surgery. Prostate and related organs were dissected from seven cadavers. After dissection, 165 serial sections with 300 μm thickness were derived at a 100 μm interval. The histological images were examined and imported to the computer. Three-dimensional (3D) remodeling had been performed. The findings were evaluated into three categories: macroscopic, microscopic and 3D reconstruction. Striated muscle fibers had been detected at the anterior fibromuscular stroma in histological sections. In 3D remodeling, urethra seemed to be a complete functional unit, beginning from the trigone up to the membranous urethra. The neurovascular bundles run under the pelvic fascia on both sides and go through to the bladder neck at 5 and 7 o'clock. Computer remodeling demonstrated that neurovascular structures had a close association with the bladder neck and the seminal vesicle. Computer program made it possible to rotate all 3D-reconstructed figures by 360° and examine them from all possible angles. All reconstructed structures can be examined together at the same time or one by one. Surgeons must pay special attention to the continence area described as a single unit, beginning from trigone to the membranous urethra, during the surgery. Meticulous dissection of the neurovascular bundles, especially close to the seminal vesicles and bladder neck, during the radical prostatectomy is necessary. These reconstructions can be used for the educational purpose of medical students as well as the urology surgeons

Effect of testosterone propionate on hippocampal pyramidal neuron number in female rats

INTRODUCTION The hippocampus is an important region of the brain that regulates cognitive and emotional functions. In this study, we examined the impact of perinatal administration of testosterone propionate (TP) on the number of pyramidal neurons in the CA1 and CA3 regions of the hippocampi of female rats. METHODS Five groups of rats were used in this study. Three groups of female rats were administered TP in either both the prenatal and the postnatal periods (Group 1), only the prenatal period (Group 2) or only the postnatal period (Group 3). The other two groups of rats included control females (Group 4) and control males (Group 5). The rats were sacrificed on postnatal Day 120 and their brains were analysed for hippocampal pyramidal neuron number using stereological methods. RESULTS Control male rats (Group 5; p = 0.043) and TP-treated female rats in Groups 1 (p = 0.012) and 2 (p = 0.037), but not Group 3 (p > 0.05), had a significantly higher number of pyramidal neurons than control female rats (Group 4). The rats in Group 1 had the highest number of pyramidal neurons among the female rats. CONCLUSION Perinatal TP treatment has an augmenting effect on the number of pyramidal neurons in the hippocampi of female rats. We also found gender-based differences in the hippocampi of male and female rats, with a higher number of pyramidal neurons seen in male rats. Continuous TP administration during the prenatal and postnatal periods is more effective than administration only in the prenatal or postnatal period

Compact Toffoli gate using weighted graph states

We introduce three compact graph states that can be used to perform a measurement-based Toffoli gate. Given a weighted graph of six, seven or eight qubits, we show that success probabilities of 1/4, 1/2 and 1 respectively can be achieved. Our study puts a measurement-based version of this important quantum logic gate within the reach of current experiments. As the graphs are setup-independent, they could be realized in a variety of systems, including linear optics and ion-traps.Comment: 4 pages, 3 figures, RevTeX4; Accepted versio