Non-classical properties and algebraic characteristics of negative binomial states in quantized radiation fields

We study the nonclassical properties and algebraic characteristics of the negative binomial states introduced by Barnett recently. The ladder operator formalism and displacement operator formalism of the negative binomial states are found and the algebra involved turns out to be the SU(1,1) Lie algebra via the generalized Holstein-Primarkoff realization. These states are essentially Peremolov's SU(1,1) coherent states. We reveal their connection with the geometric states and find that they are excited geometric states. As intermediate states, they interpolate between the number states and geometric states. We also point out that they can be recognized as the nonlinear coherent states. Their nonclassical properties, such as sub-Poissonian distribution and squeezing effect are discussed. The quasiprobability distributions in phase space, namely the Q and Wigner functions, are studied in detail. We also propose two methods of generation of the negative binomial states.Comment: 17 pages, 5 figures, Accepted in EPJ

A Review of Chinese Ice Caves

Ice caves are a rare geological phenomenon. Ningwu ice cave, Zibaishan ice cave, and Wudalianchi ice cave are the most famous ice caves in China. We described each one in detail and carried out thermal-elastic modeling and heat conduction modeling to investigate the stability of the cave and the formation of ice deposit. In order to quantitatively study the mechanism of formation and preservation of the ice cave, we applied the FEM to model the heat exchange in the ice cave. The modeling results revealed that there is the seasonal asymmetric energy exchange. Heat energy is conducted inefficiently into the ice cave from outside and wall rock in spring, summer, and autumn. While in winter, heat energy is transferred very efficiently due to the air natural convection, thus cooling it down. We proposed that Ningwu ice cave and Zibaishan ice cave may be a self-regulating system, respectively. At Wudalianchi ice cave, airtight doors have been installed at these ice caves’ entrances. This actually prevents cooling in winter. We expect that no airtight door will be fixed at each ice cave’s entrance, and few people enter the ice cave before comprehensive and detailed studies, avoiding further affecting its natural conditions

Top quark pair production at small transverse momentum in hadronic collisions

We investigate the transverse momentum resummation for top quark pair production at hadron colliders using the soft-collinear effective theory and the heavy-quark effective theory. We derive the factorization formula for $t\bar{t}$ production at small pair transverse momentum, and show in detail the procedure for calculating the key ingredient of the factorization formula: the next-to-leading order soft functions. We compare our numerical results with experimental data and find that they are consistent within theoretical and experimental uncertainties. To verify the correctness of our resummation formula, we expand it to the next-to-leading order and the next-to-next-to-leading order, and compare those expressions with the exact fixed-order results numerically. Finally, using the results of transverse momentum resummation, we discuss the transverse-momentum-dependent forward-backward asymmetry at the Tevatron.Comment: 39 pages, 7 figures, 1 table; final version in PR

Epigenetics involvement in Parkinson’s disease and manganese-induced neurotoxicity

Parkinson's disease (PD) is a progressive neurological disorder of CNS and one of the most common neurodegenerative diseases. The exact mechanisms underlying PD has been unclear but it is believed that multiple factors are involved. Excessive exposure to manganese (Mn) can causes its accumulation in the human brain and subsequent neural damage and even development of PD-like movement disorder, referred to as manganism. Although recent studies indicated the pathologic and clinical distinction between PD and Mn-induced neurotoxicity, genetically they have been shown some common features and associations. In recent years, the role of epigenetic changes has been well studied in brain development as well as different brain diseases including PD. Meanwhile, environmental agents including Mn have been found to damage the developing and mature nervous system through altering epigenetic regulatory pathways such as DNA methylation. The aim of this contribution was to review the epigenetic involvement in the etiology of PD and Mn-induced neurotoxicity. Other aspects of these syndromes were also discussed. Several lines of evidence have indicated that epigenetic modulation of gene plays more important roles in PD processes. On the other hand, Maternal Mn exposure has been found to be able to cause epigenetic changes in genes associated with neurodegeneration. The current data is very limited to show the association of MN-induced epigenetic changes and PD etiology. Although conclusion about the relationship between PD and Mn exposure need more consolidated studies, studying the molecular mechanisms of the effect of Mn, genetically and epigenetically will be helpful to understand the etiology of PD which is essential for therapeutic strategies of this disease

Meta-analysis of clinical randomized controlled trials comparing ReZOOM with ReSTOR multifocal intraocular lenses in cataract surgery

AIM: To systematic review the effectiveness of refractive multifocal intraocular lens(MIOL)ReZOOM <i>vs</i> diffractive MIOL ReSTOR in the treatment of cataract.<p>METHODS: Randomized controlled trials comparing refractive MIOL ReZOOM with diffractive MIOL ReSTOR were identified by searching CENTRAL, MEDLINE, EMbase, WANFANG MED ONLINE, CMJD, SinoMed, and CNKI. Related journals also were hand-searched. Methodological quality of randomized controlled trials(RCTs)was evaluated by simple evaluate method that recommended by the Cochrane Collaboration. Data extracted by two reviewers with designed extraction form. RevMan software(release 5.2)was used for data management and analysis.<p>RESULTS:A total of 7 trials(846 eyes)were included for systematic review. Subgroup analyses were used according to different model comparison of ReSTOR MIOL. The results showed a significant difference in the mean of the best distance corrected intermediate visual acuity(BDCIVA)in the ReZOOM MIOL group with WMD= -0.11, 95% <i>CI</i>(-0.16, -0.06)(<i>P</i><0.0001). It showed a significantly difference in the mean of the uncorrected near visual acuity(UCNVA), complete spectacle independent rate, halo rate and glare rate in the ReSTOR MIOL group with WMD= 0.09, 95% <i>CI</i>(0.05, 0.14)(<i>P</i><0.00001), WMD= 2.62, 95%<i>CI</i>(1.76, 3.91)(<i>P</i><0.00001), WMD=1.35, 95% <i>CI</i>(1.15, 1.60)(<i>P</i>=0.0004)and WMD= 1.29, 95% <i>CI</i>(1.09, 1.53)(<i>P</i>=0.003). There was no significant difference between the two groups in the mean of the uncorrected distance visual acuity(UCDVA), the uncorrected intermediate visual acuity(UCIVA), the best corrected distance visual acuity(BCDVA)and the best distance corrected near visual acuity(BDCNVA)with WMD -0.03, 95% <i>CI</i>(-0.06, 0.01)(<i>P</i>=0.15), WMD= -0.04, 95% <i>CI</i>(-0.09, 0.01)(<i>P</i>=0.10), WMD= -0.01, 95%<i>CI</i>(-0.04, 0.02)(<i>P</i>=0.55)and WMD= 0.06, 95% <i>CI</i>(-0.06, 0.17)(<i>P</i>=0.32). <p>CONCLUSION: Patients implanted with ReZOOM MIOL can provide better BDCIVA; patients implanted with ReSTOR MIOL show better UCNVA, are less likely to appear light halo, glare and other visual adverse reactions; correction in spectacles cases, patients implanted with ReZOOM or ReSTOR MIOL have considerable performances in the far and near visual acuity