Pseudogap, Superconducting Energy Scale, and Fermi Arcs in Underdoped Cuprate Superconductors

Through the measurements of magnetic field dependence of specific heat in $La_{2-x}Sr_xCuO_4$ in zero temperature limit, we determined the nodal slope $v_\Delta$ of the quasiparticle gap. It is found that $v_\Delta$ has a very similar doping dependence of the pseudogap temperature $T^*$ or value $\Delta_p$. Meanwhile the virtual maximum gap at ($\pi,0$) derived from $v_\Delta$ is found to follow the simple relation $\Delta_q=0.46k_BT^*$ upon changing the doping concentration. This strongly suggests a close relationship between the pseudogap and superconductivity. It is further found that the superconducting transition temperature is determined by both the residual density of states of the pseudogap phase and the nodal gap slope in the zero temperature limit, namely, $T_c \approx \beta v_\Delta \gamma_n(0)$, where $\gamma_n(0)$ is the extracted zero temperature value of the normal state specific heat coefficient which is proportional to the size of the residual Fermi arc $k_{arc}$. This manifests that the superconductivity may be formed by forming a new gap on the Fermi arcs near nodes below $T_c$. These observations mimic the key predictions of the SU(2) slave boson theory based on the general resonating-valence-bond (RVB) picture.Comment: 6 pages, 6 figures, to be published in Phys. Rev.

Neotropical Copestylum Macquart (Diptera: Syrphidae) Breeding in Fruits and Flowers, Including 7 New Species

Ten species of Copestylum (Diptera: Syrphidae) were reared from fruits and flowers in Costa Rica, Ecuador and Trinidad. Seven were new and in this paper, we describe them, their development sites and the third stage larva and/or the puparium of all ten species. One new synonym is proposed, Copestylum pinkusi (Curran) [= Copestylum cinctiventre (Curran)]. Similarities and differences between these new and other Copestylum species, suggest they separate into two groups, referred to as the Vagum and Cinctiventre species groups. Features characterising these groups for both adult and early stages are assessed. Each species was also distinguished using adult and early stage characters. Within the Vagum group, adults were more disparate morphologically than the larval stage; this was reversed in the Cinctiventre group. Adult colour patterns are probably cryptic in function and for disguise. Vagum species have disruptive marks, while the Cinctiventre species have reflective colours. Biologically, the groups are almost distinguished by larval development sites. Vagum species use predominantly fruits and have a larval stage that is relatively generalised in form and habit. Cinctiventre species are confined to developing in flowers and the larva is more specialised. A key to both adult and early stages of all ten species is provided.Fieldwork was funded by the AECID, Agencia Española de Cooperación Internacional para el Desarrollo, Ministerio de Asuntos Exteriores y de Cooperación (A/4426/05, A/6788/06, A/3415/05, A/020305/08 and A/019887/08; www.aecid.es). The taxonomic study was funded by the S.W. Williston Diptera Research Fund of the Smithsonian Institution (http://entomology.si.edu/) and the Pelham-Clinton Fellowship Fund of the National Museums Scotland (E.C. Pelham-Clinton Fellowship, reference NMS10/73; www.nms.ac.uk)

Quark Number Susceptibility and QCD Phase Transition in the Predictive Soft-wall AdS/QCD Model with Finite Temperature

Based on the infrared improved soft-wall AdS/QCD model which can lead to a consistent prediction for the mass spectra of light resonance mesons, we extend it to the finite temperature system and carry out the calculation for the quark number susceptibility with finite quark mass. As a consequence, we show that the quark number susceptibility grows rapidly with a continuous blow-up in a narrow temperature interval as the temperature increases, and there is a peak when the temperature is around $T \simeq 160 \sim 190$ MeV depending slightly on the models, the resulting critical temperature is about 170MeV, which agrees remarkably with the lattice QCD calculation.Comment: 12 pages, 4 figures, typos corrected, references added, published version in PR

Dynamics of iron atoms across the pressure-induced Invar transition in Pd_3Fe

The ^(57)Fe phonon partial density of states (PDOS) in L1_2-ordered Pd_3Fe was studied at high pressures by nuclear resonant inelastic x-ray scattering (NRIXS) measurements and density functional theory (DFT) calculations. The NRIXS spectra showed that the stiffening of the ^(57)Fe PDOS with decreasing volume was slower from 12 to 24 GPa owing to the pressure-induced Invar transition in Pd_3Fe, with a change from a high-moment ferromagnetic (FM) state to a low-moment (LM) state observed by nuclear forward scattering. Force constants obtained from fitting to a Born–von Kármán model showed a relative softening of the first-nearest-neighbor (1NN) Fe-Pd longitudinal force constants at the magnetic transition. For the FM low-pressure state, the DFT calculations gave a PDOS and 1NN longitudinal force constants in good agreement with experiment, but discrepancies for the high-pressure LM state suggest the presence of short-range magnetic order

Intrathecal Delivery of Ketorolac Loaded In Situ Gels for Prolonged Analgesic and Anti-Inflammatory Activity in Vertebral Fracture

Purpose: To develop biodegradable, polymeric in situ gels based on sodium alginate and hydroxypropyl methylcellulose for intrathecal delivery of ketorolac tromethamine (KT) for effective management of pain and inflammation in vertebral fracture.Method: Ion activated in situ gels were used as implants and were prepared from sodium alginate and hydroxypropyl methylcellulose. The fabricated gels were evaluated for visual appearance, clarity, pH, gelling capacity, drug content, viscosity (using Brookfield viscometer), in vitro drug release (using a fabricated KC cell) and in vivo analgesic and anti-inflammatory activity (by intrathecal administration of in situ gel near the fractured vertebra in a rat model).Results: The physicochemical properties (visual appearance, clarity, pH, gelling capacity, drug content and viscosity) of in situ gels were acceptable for therapeutic use. KT-loaded gels demonstrated high drug encapsulation efficiency (98.3 - 103.3 %). Further, KT-loaded gels exhibited viscosity in the range of 1.11 to 6 cps at 50 rpm and shear thinning property (rheology testing). Additionally, the gels demonstrated 84.43 to 96.98 % drug release at the end of 12 h. In particular, in situ gels prepared from 1.2 % alginate/0.4 % HPMC (G7) exhibited excellent analgesic (54.28 %) and anti-inflammatory activity (51.6 % inhibition of rat paw edema) in the animal model of vertebral fracture.Conclusion: The formulated in situ gels can potentially be used as implants for the treatment of patients with vertebral fracture.Keywords: Ketorolac, Orthopaedic implant, Extended release, Analgesic, Anti inflammation, Vertebral fractur

Ancestral roles of the Fam20C family of secreted protein kinases revealed in C. elegans.

Fam20C is a secreted protein kinase mutated in Raine syndrome, a human skeletal disorder. In vertebrates, bone and enamel proteins are major Fam20C substrates. However, Fam20 kinases are conserved in invertebrates lacking bone and enamel, suggesting other ancestral functions. We show that FAMK-1, the Caenorhabditis elegans Fam20C orthologue, contributes to fertility, embryogenesis, and development. These functions are not fulfilled when FAMK-1 is retained in the early secretory pathway. During embryogenesis, FAMK-1 maintains intercellular partitions and prevents multinucleation; notably, temperature elevation or lowering cortical stiffness reduces requirement for FAMK-1 in these contexts. FAMK-1 is expressed in multiple adult tissues that undergo repeated mechanical strain, and selective expression in the spermatheca restores fertility. Informatic, biochemical, and functional analysis implicate lectins as FAMK-1 substrates. These findings suggest that FAMK-1 phosphorylation of substrates, including lectins, in the late secretory pathway is important in embryonic and tissue contexts where cells are subjected to mechanical strain

Exact diagonalization of the generalized supersymmetric t-J model with boundaries

We study the generalized supersymmetric $t-J$ model with boundaries in three different gradings: FFB, BFF and FBF. Starting from the trigonometric R-matrix, and in the framework of the graded quantum inverse scattering method (QISM), we solve the eigenvalue problems for the supersymmetric $t-J$ model. A detailed calculations are presented to obtain the eigenvalues and Bethe ansatz equations of the supersymmetric $t-J$ model with boundaries in three different backgrounds.Comment: Latex file, 32 page