Heterosis, and expressivity of apospory in tetraploid Bahiagrass hybrids

Breeding procedures developed for apomictic species are based on the idea of fixing superior hybrids by apomixis. However, scarce information is available about the occurrence of heterosis in apomictic hybrids. The objective was to generate a group of apomixis-segregating tetraploid bahiagrass families, evaluate the occurrence of heterosis for a series of agronomic and morphological traits, determine the level of apospory expressivity among hybrids, and estimate the genetic distance among parents and its relationship to heterosis and apospory expressivity. In total, 11 tetraploid families were generated by crossing sexual and apomitic genotypes. The segregation for mode of reproduction was analyzed using a RAPD marker linked to apospory in bahiagrass, and the level of apospory expressivity was determined using embryo sac observations. The genetic distances between parents were determined using ISSR markers. The ratio between sexual and aposporic hybrids varied from 1:1 to 7:1 among families. Discontinuous variation for apospory expressivity was observed in the hybrids, with either low or high levels being exhibited. Mid-parent, high-parent, and standard-heterosis was observed for all evaluated agronomic characteristics. The level of heterosis was dependent on the combination of parents involved, and also on the specific trait. There was a low correlation between genetic distances among parents and initial growth and the level of apospory expressivity. The occurrence of heterosis, and the segregation and expressivity for apospory were highly dependent on the combination of sexual and apomictic parents.Fil: Zilli, Alex Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); ArgentinaFil: Brugnoli, Elsa Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); ArgentinaFil: Marcón, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); ArgentinaFil: Billa, M. B.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); ArgentinaFil: Rios, Esteban Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); ArgentinaFil: Martínez, Eric Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); ArgentinaFil: Acuña, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Nordeste. Instituto de Botánica del Nordeste (i); Argentin

Calculation of αˉQ.E.D.\bar{\alpha}_{\rm Q.E.D.} on the Z

We perform a new, detailed calculation of the hadronic contributions to the running electromagnetic coupling, $\bar{\alpha}$, defined on the Z particle (91 GeV). We find for the hadronic contribution, including radiative corrections, 10^5\times \deltav_{\rm had.}\alpha(M_Z^2)= 2740\pm12, or, excluding the top quark contribution, 10^5\times \deltav_{\rm had.}\alpha^{(5)}(M_Z^2)= 2747\pm12. Adding the pure QED corrections we get a value for the running electromagnetic coupling of $$\bar{\alpha}_{\rm Q.E.D.}(M_Z^2)= {{1}\over{128.965\pm0.017}}.$$Comment: Version to appear in Phys. Rev. D. Plain TeX fil

Modelling urban growth evolution and land-use changes using GIS based cellular automata and SLEUTH models: the case of Sana'a metropolitan city, Yemen.

An effective and efficient planning of an urban growth and land use changes and its impact on the environment requires information about growth trends and patterns amongst other important information. Over the years, many urban growth models have been developed and used in the developed countries for forecasting growth patterns. In the developing countries however, there exist a very few studies showing the application of these models and their performances. In this study two models such as cellular automata (CA) and the SLEUTH models are applied in a geographical information system (GIS) to simulate and predict the urban growth and land use change for the City of Sana’a (Yemen) for the period 2004–2020. GIS based maps were generated for the urban growth pattern of the city which was further analyzed using geo-statistical techniques. During the models calibration process, a total of 35 years of time series dataset such as historical topographical maps, aerial photographs and satellite imageries was used to identify the parameters that influenced the urban growth. The validation result showed an overall accuracy of 99.6 %; with the producer’s accuracy of 83.3 % and the user’s accuracy 83.6 %. The SLEUTH model used the best fit growth rule parameters during the calibration to forecasting future urban growth pattern and generated various probability maps in which the individual grid cells are urbanized assuming unique “urban growth signatures”. The models generated future urban growth pattern and land use changes from the period 2004–2020. Both models proved effective in forecasting growth pattern that will be useful in planning and decision making. In comparison, the CA model growth pattern showed high density development, in which growth edges were filled and clusters were merged together to form a compact built-up area wherein less agricultural lands were included. On the contrary, the SLEUTH model growth pattern showed more urban sprawl and low-density development that included substantial areas of agricultural lands

Electrodes of poly(n-methyl pyrrole)/Au and poly(maminobenzene sulfonic acid)-functionalized multiwalled carbon nanotubes for supercapacitor applications

An assembly of poly(N-methyl pyrrole) (PMP) doped with poly(3-styrene sulfonate) with embedded Au nanoparticles (PMP/Au) was grown by electropolymerization of the monomer (MP) followed by adsorption of a Au colloid. Multiwalled carbon nanotubes were functionalized with poly(m-aminobenzene sulfonic acid) (MWCNT/PABS) and deposited electrophor-etically over conducting substrates. X-ray diffraction (XRD) and Raman studies confirmed the successful functionalization of the MWCNTs by PABS. A new asymmetric supercapacitor design incorporating PMP/Au and MWCNT/PABS as electrodes was implemented for the first time, and the cell delivered a reversible specific capacitance of 967 Fg -1 and a maximum energy density of 174WhKg -1, which was superior to a PMP-MWCNT/PABS cell (167 Fg -1) and higher than many reported capacitances of poly(pyrrole)-based supercapacitors. The PMP/Au electrode outperformed pristine PMP, graphite, and MWCNT/PABS electrodes in a study of different symmetric and asymmetric cells employing these electrodes. Scanning spreading resistance microscopy (SSRM) and conducting atomic force microscopy (C-AFM) showed a lower spreading resistance and a larger nanoscale electronic conductivity for the PMP/Au electrode than for the pristine PMP electrode; these attributes allow unhindered charge transport both in the radial direction and across the cross-section of the PMP/Au electrode. The facile electron propagation in the PMP/Au electrode, enabled by the presence of localized conducting domains of Au nanoparticles implanted in the PMP electrode, effectively translates into an enhanced specific capacitance of PMP/Au-based cells relative to PMP. The results demonstrate that asymmetrically designed cells offer an exciting way to boost the overall performance of supercapacitor