Pairing patterns and fitness in a free-ranging population of pinyon jays: What do they reveal about mate choice.

Pairing in 141 pairs of Pinyon Jays (Gymnorhinus cyanocephalus ) was assortative for age, but was random for bill length and body weight. Assortative pairing for age may be favored because similar-aged partners produced slightly more young than dissimilar-aged ones and their young survived longer than young from dissimilar-aged pairs. Large jays appear to have the highest genetic quality because they lived longer and body size was heritable. Genetic quality of a mate, however, may be negated if phenotypic properties of partners are not compatible

Site-selective laser spectroscopy of Nd 3+ ions in 0.8CaSiO 3-0.2Ca 3(PO 4) 2 biocompatible eutectic glass-ceramics

In this work we report the influence of the crystallization stage of the host matrix on the spectroscopic properties of Nd3+ ions in biocompatible glass-ceramic eutectic rods of composition 0.8CaSiO3-0.2Ca3(PO4)2 doped with 1 and 2 wt% of Nd2O3. The samples were obtained by the laser floating zone technique at different growth rates between 50 and 500 mm/h. The microstructural analysis shows that a growth rate increase or a rod diameter decrease leads the system to a structural arrangement from three (two crystalline and one amorphous) to two phases (one crystalline and one amorphous). Electron backscattering diffraction analysis shows the presence of Ca2SiO4 and apatite-like crystalline phases. Site-selective laser spectroscopy in the 4I9/2¿4F3/2/4F5/2 transitions confirms that Nd3+ ions are incorporated in crystalline and amorphous phases in these glass-ceramic samples. In particular, the presence of Ca2SiO4 crystalline phase in the samples grown at low rates, which has an excellent in vitro bioactivity, can be unambiguously identified from the excitation spectra and lifetime measurements of the 4F3/2 state of Nd3+ ions

ARHGEF18/p114RhoGEF Coordinates PKA/CREB Signaling and Actomyosin Remodeling to Promote Trophoblast Cell-Cell Fusion During Placenta Morphogenesis

Coordination of cell-cell adhesion, actomyosin dynamics and gene expression is crucial for morphogenetic processes underlying tissue and organ development. Rho GTPases are main regulators of the cytoskeleton and adhesion. They are activated by guanine nucleotide exchange factors in a spatially and temporally controlled manner. However, the roles of these Rho GTPase activators during complex developmental processes are still poorly understood. ARHGEF18/p114RhoGEF is a tight junction-associated RhoA activator that forms complexes with myosin II, and regulates actomyosin contractility. Here we show that p114RhoGEF/ARHGEF18 is required for mouse syncytiotrophoblast differentiation and placenta development. In vitro and in vivo experiments identify that p114RhoGEF controls expression of AKAP12, a protein regulating protein kinase A (PKA) signaling, and is required for PKA-induced actomyosin remodeling, cAMP-responsive element binding protein (CREB)-driven gene expression of proteins required for trophoblast differentiation, and, hence, trophoblast cell-cell fusion. Our data thus indicate that p114RhoGEF links actomyosin dynamics and cell-cell junctions to PKA/CREB signaling, gene expression and cell-cell fusion

Time-resolved fluorescence line-narrowing of Eu3+ in biocompatible eutectic glass-ceramics

The spectroscopic properties of Eu3+ in biocompatible glass and glass-ceramic eutectic rods of composition 0.8CaSiO3-0.2Ca3(PO4)2 doped with 0.5 wt% of Eu2O3 are investigated to explore their potential applications as optical probes. The samples were obtained by the laser floating zone technique. Depending on the growth rate, they exhibit three (two crystalline and one amorphous) or two (one crystalline and one amorphous) phases. The crystalline phases correspond to Ca2SiO4 and apatite-like structures. At high growth rates the system presents an amorphous arrangement which gives a glass phase. The results of time-resolved fluorescence line narrowing spectroscopy obtained under excitation within the inhomogeneous broadened 7F0¿5D0 absorption band allow to isolate the emission from Eu3+ ions in the crystalline and amorphous environments and to accurately correlate the spectroscopic properties with the microstructure of these eutectics

Spectroscopy of thulium and holmium heavily doped tellurite glasses

In this study, we report spectroscopic properties of Tm3þ and Ho3þ codoped tellurite glasses over a wide dopant concentration range in order to assess their potential laser performance under 790 nm diode laser excitation. The impact of Tm3þ and Ho3þ concentrations is investigated to identify specific candidates for fiber laser operation. The emission cross section is calculated and discussed, as well as the gain coefficient of this type of glasses. Energy transfer microparameters and critical ion distances are determined for 3H4, 3F4 (Tm3þ), and 5I7 (Ho3þ) emission levels in the framework of diffusionlimited regime and dipole-dipole interaction. We also report thermal properties of tested glasse

Chemical kinetics in solar to chemical energy conversion: The photoelectrochemical oxygen transfer reaction

After introducing the basic aspects of the photoelectrochemical processes for the oxygen transfer reaction, we present the simplest kinetics models that have been built to represent the dynamics of light-induced redox reactions. Additionally, we discuss the basic chemical kinetics formalism usedin photocatalysis and photoelectrochemistry, where interplay between the oxidation process and nonequilibrium adsorbed states is considered. We also comment about the experimental developments related to the treatment of wastewater with electricity or H2 generation. Finally, we discuss the need to measure reaction rates to determine and compare the physicochemical parameters describing thechemical interactions during photoelectrochemical processes, in order to understand these reactive systems and apply them to new challenges related to the environment and energy.Fil: Vargas Balda, Ronald Eduardo. Universidad Simon Bolivar.; Venezuela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); ArgentinaFil: Carvajal, David. Universidad Simon Bolivar.; VenezuelaFil: Madriz Ruiz, Lorean Mercedes. Universidad Simon Bolivar.; Venezuela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Scharifker, Benjamín R.. Universidad Simon Bolivar.; Venezuela. Universidad Metropolitana.; Venezuel