A new species group and two new species of freyine jumping spiders (Araneae, Salticidae, Aelurillini)

Wedoquella apnnea sp. nov. and W. karadya sp. nov., two new species of the jumping spider subtribe Freyina are described and illustrated from specimens recently collected in Misiones and Chaco provinces, Northeastern Argentina. The new species are placed into a new group of Wedoquella because, although in body morphology they resemble the Phiale gratiosa group, the genital structures of both sexes more closely resemble those of Wedoquella, and a preliminary analysis based on mitochondrial COI sequences places this new group as sister to Wedoquella rather than to Phiale. Both new species are similar, but can be distinguished mainly by differences in the retrolateral tibial apophysis of the male palp. Females have a slight intraspecific color variation.Un grupo nuevo de especies y dos especies nuevas de arañas saltarinas freyinas (Araneae, Salticidae, Aelurillini). Wedoquella apnnea sp. nov. y W. karadya sp. nov., son descriptas e ilustradas a partir de especímenes colectados recientemente en las provincias de Misiones y Chaco, Nordeste de Argentina. Las nuevas especies se asemejan morfológicamente a las del grupo gratiosa de Phiale, sin embargo, son colocadas dentro de un nuevo grupo de Wedoquella debido a que las estructuras reproductoras de ambos sexos se asemejan más estrechamente a las de éste género, y un análisis preliminar basado en secuencias mitocondriales de COI ubica a este nuevo grupo como hermano de Wedoquella en lugar de Phiale. Ambas especies nuevas son similares, pero pueden distinguirse principalmente por diferencias en la apófisis retrolateral tibial del palpo masculino. Las hembras tienen una ligera variación intraespecífica de color.EEA Cerro AzulFil: Rubio, Gonzalo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Cerro Azul; ArgentinaFil: Nadal, María Florencia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas, Naturales y Agrimensura. Laboratorio de Biología de los Artrópodos; ArgentinaFil: Baigorria, Julián Emanuel Martín. Fundación de Historia Natural Félix de Azara; ArgentinaFil: Oklander, Luciana Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología Subtropical. Universidad Nacional de Misiones. Instituto de Biología Subtropical; ArgentinaFil: Edwards, G.B. Florida State Collection of Arthropods. Division of Plant Industry; Estados Unido

Biology, Predation Ecology, and Significance of Spiders in Texas Cotton Ecosystems with a Key to the Species.

124 p

Cluster Spin Glass Distribution Functions in La2−x_{2-x}Srx_xCuO4_4

Signatures of the cluster spin glass have been found in a variety of experiments, with an effective onset temperature $T_{on}$ that is frequency dependent. We reanalyze the experimental results and find that they are characterized by a distribution of activation energies, with a nonzero glass transition temperature $T_g(x)<T_{on}$. While the distribution of activation energies is the same, the distribution of weights depends on the process. Remarkably, the weights are essentially doping independent.Comment: 5 pages, 5 ps figure

Rotation measure variations for 20 millisecond pulsars

We report on variations in the mean position angle of the 20 millisecond pulsars being observed as part of the Parkes Pulsar Timing Array (PPTA) project. It is found that the observed variations are dominated by changes in the Faraday rotation occurring in the Earth's ionosphere. Two ionospheric models are used to correct for the ionospheric contribution and it is found that one based on the International Reference Ionosphere gave the best results. Little or no significant long-term variation in interstellar RM was found with limits typically about 0.1 rad m$^{-2}$ yr$^{-1}$ in absolute value. In a few cases, apparently significant RM variations over timescales of a few 100 days or more were seen. These are unlikely to be due to localised magnetised regions crossing the line of sight since the implied magnetic fields are too high. Most probably they are statistical fluctuations due to random spatial and temporal variations in the interstellar electron density and magnetic field along the line of sight.Comment: Accepted for publication in Astrophysics & Space Scienc

Development of an eight-band theory for quantum-dot heterostructures

We derive a nonsymmetrized 8-band effective-mass Hamiltonian for quantum-dot heterostructures (QDHs) in Burt's envelope-function representation. The 8x8 radial Hamiltonian and the boundary conditions for the Schroedinger equation are obtained for spherical QDHs. Boundary conditions for symmetrized and nonsymmetrized radial Hamiltonians are compared with each other and with connection rules that are commonly used to match the wave functions found from the bulk kp Hamiltonians of two adjacent materials. Electron and hole energy spectra in three spherical QDHs: HgS/CdS, InAs/GaAs, and GaAs/AlAs are calculated as a function of the quantum dot radius within the approximate symmetrized and exact nonsymmetrized 8x8 models. The parameters of dissymmetry are shown to influence the energy levels and the wave functions of an electron and a hole and, consequently, the energies of both intraband and interband transitions.Comment: 36 pages, 10 figures, E-mail addresses: [email protected], [email protected]

Comparative analysis of c-kit gene expression and c-Kit immunoreactivity in horses with and without obstructive intestinal disease

Previous immunohistochemical studies targeting the receptor tyrosine kinase (c-Kit) have demonstrated an apparent reduction in the number of gastrointestinal pacemaker cells--the interstitial cells of Cajal (ICC)--in horses with intestinal motility disorders. This study compared the level of transcription of the c-kit gene encoding this receptor in horses with and without such motility disorders. Transcription levels of this gene were also compared to the density of ICC immunohistochemically positive for the c-Kit antigen. Intestinal samples were collected from 18 horses with intestinal disease and from 15 control animals. Following gene extraction and identification, real-time quantitative analysis of c-kit and a control gene, ACTB (β-actin), was carried out on all samples and the density of the c-Kit-positive ICC compared. There was a significant reduction in c-Kit immunoreactivity in the ICC of horses with large intestinal obstructive disorders relative to controls but no significant difference in the transcription of the c-kit gene between normal and affected animals. Further studies will be required to elucidate the mechanisms regulating c-Kit expression and to assess the pathophysiological significance of these findings

Scale-free static and dynamical correlations in melts of monodisperse and Flory-distributed homopolymers: A review of recent bond-fluctuation model studies

It has been assumed until very recently that all long-range correlations are screened in three-dimensional melts of linear homopolymers on distances beyond the correlation length $\xi$ characterizing the decay of the density fluctuations. Summarizing simulation results obtained by means of a variant of the bond-fluctuation model with finite monomer excluded volume interactions and topology violating local and global Monte Carlo moves, we show that due to an interplay of the chain connectivity and the incompressibility constraint, both static and dynamical correlations arise on distances $r \gg \xi$. These correlations are scale-free and, surprisingly, do not depend explicitly on the compressibility of the solution. Both monodisperse and (essentially) Flory-distributed equilibrium polymers are considered.Comment: 60 pages, 49 figure

Mutation of Ser172 in Yeast β Tubulin Induces Defects in Microtubule Dynamics and Cell Division

Ser172 of β tubulin is an important residue that is mutated in a human brain disease and phosphorylated by the cyclin-dependent kinase Cdk1 in mammalian cells. To examine the role of this residue, we used the yeast S. cerevisiae as a model and produced two different mutations (S172A and S172E) of the conserved Ser172 in the yeast β tubulin Tub2p. The two mutants showed impaired cell growth on benomyl-containing medium and at cold temperatures, altered microtubule (MT) dynamics, and altered nucleus positioning and segregation. When cytoplasmic MT effectors Dyn1p or Kar9p were deleted in S172A and S172E mutants, cells were viable but presented increased ploidy. Furthermore, the two β tubulin mutations exhibited synthetic lethal interactions with Bik1p, Bim1p or Kar3p, which are effectors of cytoplasmic and spindle MTs. In the absence of Mad2p-dependent spindle checkpoint, both mutations are deleterious. These findings show the importance of Ser172 for the correct function of both cytoplasmic and spindle MTs and for normal cell division

Study of CP violation in Dalitz-plot analyses of B0 --> K+K-KS, B+ --> K+K-K+, and B+ --> KSKSK+

We perform amplitude analyses of the decays $B^0 \to K^+K^-K^0_S$, $B^+ \rightarrow K^+K^-K^+$, and $B^+ \to K^0_S K^0_S K^+$, and measure CP-violating parameters and partial branching fractions. The results are based on a data sample of approximately $470\times 10^6$ $B\bar{B}$ decays, collected with the BABAR detector at the PEP-II asymmetric-energy $B$ factory at the SLAC National Accelerator Laboratory. For $B^+ \to K^+K^-K^+$, we find a direct CP asymmetry in $B^+ \to \phi(1020)K^+$ of $A_{CP}= (12.8\pm 4.4 \pm 1.3)$, which differs from zero by $2.8 \sigma$. For $B^0 \to K^+K^-K^0_S$, we measure the CP-violating phase $\beta_{\rm eff} (\phi(1020)K^0_S) = (21\pm 6 \pm 2)^\circ$. For $B^+ \to K^0_S K^0_S K^+$, we measure an overall direct CP asymmetry of $A_{CP} = (4 ^{+4}_{-5} \pm 2)$. We also perform an angular-moment analysis of the three channels, and determine that the $f_X(1500)$ state can be described well by the sum of the resonances $f_0(1500)$, $f_2^{\prime}(1525)$, and $f_0(1710)$.Comment: 35 pages, 68 postscript figures. v3 - minor modifications to agree with published versio