Residue codes of extremal Type II Z_4-codes and the moonshine vertex operator algebra

In this paper, we study the residue codes of extremal Type II Z_4-codes of length 24 and their relations to the famous moonshine vertex operator algebra. The main result is a complete classification of all residue codes of extremal Type II Z_4-codes of length 24. Some corresponding results associated to the moonshine vertex operator algebra are also discussed.Comment: 21 pages, shortened from v

Experimental entanglement distillation of mesoscopic quantum states

The distribution of entangled states between distant parties in an optical network is crucial for the successful implementation of various quantum communication protocols such as quantum cryptography, teleportation and dense coding [1-3]. However, owing to the unavoidable loss in any real optical channel, the distribution of loss-intolerant entangled states is inevitably inflicted by decoherence, which causes a degradation of the transmitted entanglement. To combat the decoherence, entanglement distillation, which is the process of extracting a small set of highly entangled states from a large set of less entangled states, can be used [4-14]. Here we report on the mesoscopic distillation of deterministically prepared entangled light pulses that have undergone non-Gaussian noise. The entangled light pulses [15-17] are sent through a lossy channel, where the transmission is varying in time similarly to light propagation in the atmosphere. By employing linear optical components and global classical communication, the entanglement is probabilistically increased.Comment: 13 pages, 4 figures. It's the first submitted version to the Nature Physics. The final version is already published on Nature Physics vol.4, No.12, 919 - 923 (2008

Mass Transfer, Transiting Stream and Magnetopause in Close-in Exoplanetary Systems with Applications to WASP-12

We study mass transfer by Roche lobe overflow in close-in exoplanetary systems. The planet's atmospheric gas passes through the inner Lagrangian point and flows along a narrow stream, accelerating to 100-200\kms velocity before forming an accretion disk. We show that the cylinder-shaped accretion stream can have an area (projected in the plane of the sky) comparable to that of the planet and a significant optical depth to spectral line absorption. Such a "transiting cylinder" may produce an earlier ingress of the planet transit, as suggested by recent HST observations of the WASP-12 system. The asymmetric disk produced by the accretion stream may also lead to time-dependent obscuration of the star light and apparent earlier ingress. We also consider the interaction of the stellar wind with the planetary magnetosphere. Since the wind speed is subsonic/sub-Alfvenic and comparable to the orbital velocity of the planet, the head of the magnetopause lies eastward relative to the substellar line (the line joining the planet and the star). The gas around the magnetopause may, if sufficiently compressed, give rise to asymmetric ingress/egress during the planet transit, although more works are needed to evaluate this possibility.Comment: 6 pages with 2 figures. Accepted in ApJ. Small changes (add discussion on asymmetric disks

Assessing the Polarization of a Quantum Field from Stokes Fluctuation

We propose an operational degree of polarization in terms of the variance of the projected Stokes vector minimized over all the directions of the Poincar\'e sphere. We examine the properties of this degree and show that some problems associated with the standard definition are avoided. The new degree of polarization is experimentally determined using two examples: a bright squeezed state and a quadrature squeezed vacuum.Comment: 4 pages, 2 figures. Comments welcome

Quantum reconstruction of an intense polarization squeezed optical state

We perform a reconstruction of the polarization sector of the density matrix of an intense polarization squeezed beam starting from a complete set of Stokes measurements. By using an appropriate quasidistribution, we map this onto the Poincare space providing a full quantum mechanical characterization of the measured polarization state.Comment: 4 pages, 4 eps color figure

Effects of Neurotrophin-3 Plasmids on Myocyte Apoptosis and Ca²⁺-ATPase Content in the Muscle After Nerve Injury in Rats

We estimated the influence of plasmids with DNA carrying the neurotrophin-3 (NT-3) gene on apoptosis in the gastrocnemius muscle and content of Ca²⁺-ATPase in the latter after sciatic nerve injury. Sixty adult Wistar rats were randomly divided into the saline (control) and NT-3 groups. The related indices, such as expression of caspase-3 protein, the rate of apoptosis in the muscle evaluated using a TUNEL technique, and the level of Ca²⁺-ATPase estimated using Western blot, were observed. Expression of caspase-3 protein was elevated at different post-operative times after peripheral nerve injury; NT-3 expression and the rate of muscle cell apoptosis decreased, whereas the level of Ca²⁺-ATPase in the sarcoplasmic reticulum increased; significant differences were observed compared with the saline group (P < 0.05). The mitigation mechanism of NT-3 on muscle atrophy after peripheral nerve injury is expressed as inhibition of caspase-3 gene expression, increase in the Ca²⁺-ATPase level, and reduction in the rate of muscle apoptosis.Ми вивчали вплив плазмід із ДНК, що несе ген нейротрофіну-3 (NT-3), на апоптоз міоцитів у m. gastrocnemius та вміст Ca²⁺-ATФази в цьому м’язі після перерізання сідничного нерва. 60 дорослих щурів лінії Вістар були рандомізовано поділені на контрольну (введення фізіологічного розчину) та NT-3-групи. Оцінювали відповідні показники – експресію протеїну каспази-3, рівень апоптозу в м’язі (з використанням TUNEL-методики) та рівень Ca²⁺-ATФази (з використанням Вестерн-блотингу). Експресія білка каспази-3 в різні часові інтервали після пошкодження периферичного нерва була підвищеною; експресія NT-3 та рівень апоптозу м’язових клітин були знижені, а вміст Ca²⁺-ATФази в саркоплазматичному ретикулумі – підвищеним. Відмінності цих показників щодо таких у контрольній групі були вірогідними (P < 0.05). Обмежуючі впливи NT-3 на процес м’язової атрофії після пошкодження периферичного нерва виявлялись як інгібування експресії гена каспази-3, підвищення вмісту Ca²⁺-ATФази та зниження інтенсивності апоптозу в м’язі

Noiseless Linear Amplification and Distillation of Entanglement

The idea of signal amplification is ubiquitous in the control of physical systems, and the ultimate performance limit of amplifiers is set by quantum physics. Increasing the amplitude of an unknown quantum optical field, or more generally any harmonic oscillator state, must introduce noise. This linear amplification noise prevents the perfect copying of the quantum state, enforces quantum limits on communications and metrology, and is the physical mechanism that prevents the increase of entanglement via local operations. It is known that non-deterministic versions of ideal cloning and local entanglement increase (distillation) are allowed, suggesting the possibility of non-deterministic noiseless linear amplification. Here we introduce, and experimentally demonstrate, such a noiseless linear amplifier for continuous-variables states of the optical field, and use it to demonstrate entanglement distillation of field-mode entanglement. This simple but powerful circuit can form the basis of practical devices for enhancing quantum technologies. The idea of noiseless amplification unifies approaches to cloning and distillation, and will find applications in quantum metrology and communications.Comment: Submitted 10 June 200

Imbalanced functional link between executive control network and reward network explain the online-game seeking behaviors in Internet gaming disorder

Literatures have shown that Internet gaming disorder (IGD) subjects show impaired executive control and enhanced reward sensitivities than healthy controls. However, how these two networks jointly affect the valuation process and drive IGD subjects' online-game-seeking behaviors remains unknown. Thirty-five IGD and 36 healthy controls underwent a resting-states scan in the MRI scanner. Functional connectivity (FC) was examined within control and reward network seeds regions, respectively. Nucleus accumbens (NAcc) was selected as the node to find the interactions between these two networks. IGD subjects show decreased FC in the executive control network and increased FC in the reward network when comparing with the healthy controls. When examining the correlations between the NAcc and the executive control/reward networks, the link between the NAcc - executive control network is negatively related with the link between NAcc - reward network. The changes (decrease/increase) in IGD subjects' brain synchrony in control/reward networks suggest the inefficient/overly processing within neural circuitry underlying these processes. The inverse proportion between control network and reward network in IGD suggest that impairments in executive control lead to inefficient inhibition of enhanced cravings to excessive online game playing. This might shed light on the mechanistic understanding of IGD

Rising to the occasion : disaster social work in China

Author name used in this manuscript: Timothy SIM2012-2013 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe