Characterization of K+ currents and the cAMP-dependent modulation in cultured Drosophila mushroom body neurons identified by lacZ expression

Electrophysiological analysis of cultured neurons provides a potential approach toward understanding the physiological defects that may contribute to abnormal behavior exhibited by mutants of the fruit fly Drosophila. However, its application has been restricted by an inability to identify a particular functional or anatomical subpopulation of neurons from the CNS. To study neurons composing the CNS mushroom body proposed as a center for insect olfactory learning, we utilized a Drosophila enhancer detector line that expresses a lacZ reporter gene in these neurons and identified them in acutely dissociated larval CNS cultures by vital fluorescent staining. The patch-clamp analysis suggests that whole-cell voltage-activated K+ currents can be classified into two types in identified mushroom body neurons. Type 1 current comprises a TEA-sensitive slowly inactivating current and noninactivating component while type 2 current contains a 4-AP-sensitive transient A-current and a noninactivating component. Application of cAMP analogs induced distinct modulation of type 1 and type 2 currents. Our results demonstrate that the expression of the lacZ gene and the subsequent staining do not significantly alter the different types of K+ currents. This initial characterization provides a basis for further analysis of mutations that impair learning and memory resulting from an abnormal cAMP cascade preferentially expressed in the mushroom body

Treatment with convalescent plasma for influenza A (H5N1) infection [9]

published_or_final_versio

QCD evolution of naive-time-reversal-odd fragmentation functions

We study QCD evolution equations of the first transverse-momentum-moment of the naive-time-reversal-odd fragmentation functions - the Collins function and the polarizing fragmentation function. We find for the Collins function case that the evolution kernel has a diagonal piece same as that for the transversity fragmentation function, while for the polarizing fragmentation function case this piece is the same as that for the unpolarized fragmentation function. Our results might have important implications in the current global analysis of spin asymmetries.Comment: 8 pages,4 figure

Time-reversal-symmetry-broken quantum spin Hall effect

Quantum spin Hall (QSH) state of matter is usually considered to be protected by time-reversal (TR) symmetry. We investigate the fate of the QSH effect in the presence of the Rashba spin-orbit coupling and an exchange field, which break both inversion and TR symmetries. It is found that the QSH state characterized by nonzero spin Chern numbers $C_{\pm}=\pm 1$ persists when the TR symmetry is broken. A topological phase transition from the TR symmetry-broken QSH phase to a quantum anomalous Hall phase occurs at a critical exchange field, where the bulk band gap just closes. It is also shown that the transition from the TR symmetry-broken QSH phase to an ordinary insulator state can not happen without closing the band gap.Comment: 5 pages, 5 figure

Optimal queue-size scaling in switched networks

We consider a switched (queuing) network in which there are constraints on which queues may be served simultaneously; such networks have been used to effectively model input-queued switches and wireless networks. The scheduling policy for such a network specifies which queues to serve at any point in time, based on the current state or past history of the system. In the main result of this paper, we provide a new class of online scheduling policies that achieve optimal queue-size scaling for a class of switched networks including input-queued switches. In particular, it establishes the validity of a conjecture (documented in Shah, Tsitsiklis and Zhong [Queueing Syst. 68 (2011) 375-384]) about optimal queue-size scaling for input-queued switches.Comment: Published in at http://dx.doi.org/10.1214/13-AAP970 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

Qualitative properties of α\alpha-fair policies in bandwidth-sharing networks

We consider a flow-level model of a network operating under an $\alpha$-fair bandwidth sharing policy (with $\alpha>0$) proposed by Roberts and Massouli\'{e} [Telecomunication Systems 15 (2000) 185-201]. This is a probabilistic model that captures the long-term aspects of bandwidth sharing between users or flows in a communication network. We study the transient properties as well as the steady-state distribution of the model. In particular, for $\alpha\geq1$, we obtain bounds on the maximum number of flows in the network over a given time horizon, by means of a maximal inequality derived from the standard Lyapunov drift condition. As a corollary, we establish the full state space collapse property for all $\alpha\geq1$. For the steady-state distribution, we obtain explicit exponential tail bounds on the number of flows, for any $\alpha>0$, by relying on a norm-like Lyapunov function. As a corollary, we establish the validity of the diffusion approximation developed by Kang et al. [Ann. Appl. Probab. 19 (2009) 1719-1780], in steady state, for the case where $\alpha=1$ and under a local traffic condition.Comment: Published in at http://dx.doi.org/10.1214/12-AAP915 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org

B(s),D(s)→π,K,η,ρ,K∗,ω,ϕB_{(s)},D_{(s)} \to \pi, K, \eta, \rho, K^*, \omega, \phi Transition Form Factors and Decay Rates with Extraction of the CKM parameters ∣Vub∣|V_{ub}|, ∣Vcs∣|V_{cs}|, ∣Vcd∣|V_{cd}|

A systematic calculation for the transition form factors of heavy to light mesons ($B,B_s,D,D_s \to \pi, K, \eta, \rho, K^*, \omega, \phi$) is carried out by using light-cone sum rules in the framework of heavy quark effective field theory. The heavy quark symmetry at the leading order of $1/m_Q$ expansion enables us to reduce the independent wave functions and establish interesting relations among form factors. Some relations hold for the whole region of momentum transfer. The meson distribution amplitudes up to twist-4 including the contributions from higher conformal spin partial waves and light meson mass corrections are considered. The CKM matrix elements $|V_{ub}|$, $|V_{cs}|$ and $|V_{cd}|$ are extracted from some relatively well-measured decay channels. A detailed prediction for the branching ratios of heavy to light meson decays is then presented. The resulting predictions for the semileptonic and radiative decay rates of heavy to light mesons ($B,B_s,D,D_s \to \pi, K, \eta, \rho, K^*, \omega, \phi$) are found to be compatible with the current experimental data and can be tested by more precise experiments at B-factory, LHCb, BEPCII and CLEOc.Comment: 23 pages, 32 figures, 25 tables,published version, minor corrections and references adde

Generarized Cubic Model for BaTiO3_3-like Ferroelectric Substance

We propose an order-disorder type microscopic model for BaTiO$_3$-like Ferroelectric Substance. Our model has three phase transitions and four phases. The symmetry and directions of the polarizations of the ordered phases agree with the experimental results of BaTiO$_3$. The intermediate phases in our model are known as an incompletely ordered phase, which appears in a generalized clock model.Comment: 6 pages, 4figure