Effect of task failure on intermuscular coherence measures in synergistic muscles

The term "task failure" describes the point when a person is not able to maintain the level of force required by a task. As task failure approaches, the corticospinal command to the muscles increases to maintain the required level of force in the face of a decreased mechanical efficacy. Nevertheless, most motor tasks require the synergistic recruitment of several muscles. How this recruitment is affected by approaching task failure is still not clear. The increase in the corticospinal drive could be due to an increase in synergistic recruitment or to overlapping commands sent to the muscles individually. Herein, we investigated these possibilities by combining intermuscular coherence and synergy analysis on signals recorded from three muscles of the quadriceps during dynamic leg extension tasks. We employed muscle synergy analysis to investigate changes in the coactivation of the muscles. Three different measures of coherence were used. Pooled coherence was used to estimate the command synchronous to all three muscles, pairwise coherence the command shared across muscle pairs and residual coherence the command peculiar to each couple of muscles. Our analysis highlights an overall decrease in synergistic command at task failure and an intensification of the contribution of the nonsynergistic shared command

Pfaffian representations of cubic surfaces

Let K be a field of characteristic zero. We describe an algorithm which requires a homogeneous polynomial F of degree three in K[x_0,x_1,x_2,x_3] and a zero A of F in P^3_K and ensures a linear pfaffian representation of V(F) with entries in K[x_0,x_1,x_2,x_3], under mild assumptions on F and A. We use this result to give an explicit construction of (and to prove the existence of) a linear pfaffian representation of V(F), with entries in K'[x_0,x_1,x_2,x_3], being K' an algebraic extension of K of degree at most six. An explicit example of such a construction is given.Comment: 17 pages. Expanded with some remarks. Published with minor corrections in Geom. Dedicat

First Report of Cladode Brown Spot in Cactus Prickly Pear Caused by Neofusicoccum batangarum in Brazil

Cactus prickly pear (Nopalea cochenilifera) cladodes showing brown spot symptoms were collected of 18 fields of the State of Pernambuco, northeastern Brazil, from March to June 2014. The symptoms were prevalent in 100% of fields surveyed. Small pieces (4 to 5 mm) of necrotic tissues were surface sterilized for 1 min in 1.5% NaOCl, washed twice with sterile distilled water, and plated onto potato dextrose agar (PDA) amended with 0.5 g /liter streptomycin sulfate. Colonies morphologically similar to species of Botryosphaeriaceae were transferred to malt extract agar (MEA); five isolates (CMM 1424, CMM 1425, CMM 1426, CMM 1427, and CMM 1428) presented colonies forming concentric rings, and white mycelium becoming gray to gray-olivaceous after 5 days. Conidial characters were observed after growth on 2% water agar bearing sterilized pine needles for 3 weeks at 25°C under near-UV light. Conidiogenous cells holoblastic, hyaline, smooth, and cylindrical. Conidia were nonseptate, hyaline, smooth, fusoid to ovoid, thin-walled, 15.3 ± 1.4 × 5.4 ± 0.6 µm (n = 50), L/W ratio= 2.8, which are morphological and cultural characteristics typical of Neofusicoccum spp. (Phillips et al. 2013). DNA sequencing of part of the elongation factor 1-alpha (EF1-α) gene and the internal transcribed spacer (ITS1-5.8S-ITS2 rDNA) region were conducted to identify the species as described by (Marques et al. 2013). Sequences of the isolates were 99% similar to those of N. batangarum for EF1-α (GenBank Accession Nos. FJ900653 and FJ900654) and ITS (FJ900607 and FJ900608).Instituto de Patología VegetalFil: Conforto, Erica Cinthia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patología Vegetal; ArgentinaFil: Bernardi Lima, Nelson. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Fitopatología y Modelización Agrícola (UFyMA); ArgentinaFil: Bernardi Lima, Nelson. Universidade Federal Rural de Pernambuco. Departamento de Agronomia; BrasilFil: Garcete-Gómez, José María. Universidade Federal Rural de Pernambuco. Departamento de Agronomia; BrasilFil: Câmara, M. P. S. Universidade Federal Rural de Pernambuco. Departamento de Agronomia; BrasilFil: Michereff, S. J. Universidade Federal Rural de Pernambuco. Departamento de Agronomia; Brasi

Mitogenome and Nuclear-encoded Fungicide-target Genes of Thecaphora frezii - Causal Agent of Peanut Smut

Background: Thecaphora frezii Carranza and Lindquist causes smut disease in peanut (Arachis hypogaea L.) resulting in up to 35% yield losses. Fungicides have shown ineffective in controlling the disease; whereas research on the molecular basis of that fungicide resistance has been hindered because of the lack of genetic information about T. frezii. The goal of this work was to provide molecular information about fungicide-target loci in T. frezii, including its mitochondrial genome (mitogenome) and critical nuclear-encoded genes. Results: Here we report the complete annotated mitogenome of T. frezii, a 123,773 bp molecule containing the standard 14 genes that form part of mitochondrial complexes I, III, IV and V, 22 transfer RNAs, small and large subunits of ribosomal RNA, DNA polymerase, ribonuclease P, GII-reverse transcriptase/maturase, nine hypothetical open-reading frames and homing endonucleases (LAGLIDADG, GIY-YIG, HEG). In addition, we report the full-length cDNA sequence of T. frezii cytochrome b (cob) and cytochrome oxidase 1 (cox1) genes; as well as partial sequences of T. frezii succinate dehydrogenase (sdhb), ergosterol biosynthesis (Erg4), cytochrome P450 (cyp51), and beta tubulin (β-tubulin) genes, which are respective targets of strobilurins, quinone oxidation inhibitors, triazoles and beta-tubulin inhibitor fungicides commonly used in the peanut crop. Translation of cob and sdhb genes in this particular T. frezii isolate suggests potential resistance to strobilurin and carboxamide fungicides. Conclusion: The mitogenome and nuclear-encoded gene sequences presented here provide the molecular tools to research T. frezii fungicide-target loci

Rates for the reactions antiproton-proton --> pi phi and gamma phi

We study antiproton-proton annihilation at rest into $\pi\phi$ and $\gamma\phi$. Rescattering by $\overline{K^*}K+K^*\overline{K}$ and $\rho^{+}\rho^{-}$ for $\overline{p}p\rightarrow\pi\phi$ states is sizable, of order $(0.90\, {\rm to}\,2.6)\times 10^{-4}$ in the branching ratio, but smaller than experiment. For $\overline{p}p\rightarrow\gamma\phi$ the rescattering contributions are negligible, but the $\gamma\phi$ channel is well explained by a $\rho\phi$ intermediate state combined with vector meson dominance.Comment: 12 pages, plain latex, 2 postscript figures available upon request, PSI-PR-93-2

Influencia de la fertilización inorgánica sobre la actividad microbiana del suelo

Las mediciones se llevaron a cabo en la campaña 2010/11 en un ensayo en el establecimiento Balducchi, ubicado en la localidad de Teodelina (Santa Fe), que forma parte de la Red de Nutrición CREA Sur de Santa Fe (CREA-IPNI-ASP). En ese ensayo, bajo rotación maíz-trigo/soja, se evalúan, anualmente desde la campaña 2000/01, fertilizaciones con N, P, S y micronutrientes en las siguientes combinaciones: PS, NS, NP, NPS, NPS+Micronutrientes, y Testigo (sin adición de fertilizante) en 3 repeticiones siguiendo un diseño en bloques completos al azar.Según la información obtenida, la actividad microbiana del suelo, medida por la cuantificación del consumo de diversas fuentes de C, fue influenciada por la fertilización inorgánica. De acuerdo al ACP, el tratamiento con nutrición más balanceada (NPS+Micros) registró mayor consumo de sustratos carbonados, que los restantes tratamientos. Según algunos autores, los fertilizantes inorgánicos afectan los parámetros biológicos debido al incremento del contenido de C orgánico del suelo, que determina el crecimiento de los microorganismos, siendo el P un factor clave en el aumento de la diversidad microbiana y fertilidad del suelo. Finalmente, el rendimiento del cultivo también se incrementó en respuesta a la fertilización, en comparación con el Testigo. Existe una compleja interacción entre el nivel óptimo de fertilización, la disponibilidad de nutrientes para el crecimiento de los microorganismos y el buen desarrollo de las plantas. Esto demuestra que son necesarios más estudios para profundizar el conocimiento acerca del efecto de la fertilización inorgánica sobre las funciones metabólicas de la microbiota del suelo.Fil: Conforto, C.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; ArgentinaFil: Correa, Olga Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Rovea, A.. Grupo Crea Santa Fe; ArgentinaFil: Boxler, M.. Grupo Crea Santa Fe; ArgentinaFil: Rodríguez Grastorf, S.. Grupo Crea Santa Fe; ArgentinaFil: Minteguiaga, J.. Grupo Crea Santa Fe; ArgentinaFil: Meriles, Jose Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Vargas Gil, Silvina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigaciones Agropecuarias. Instituto de Patología Vegetal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Equilibrium and stability properties of detonation waves in the hydrodynamic limit of a kinetic model

A shock wave structure problem, like the one which can be formulated for the planar detonation wave, is analyzed here for a binary mixture of ideal gases undergoing the symmetric reaction A1+A1=A2+A2 . The problem is studied at the hydrodynamic Euler limit of a kinetic model of the reactive Boltzmann equation. The chemical rate law is deduced in this frame with a second-order reaction rate, in a hemical regime such that the gas flow is not far away from the chemical equilibrium. The caloric and the thermal equations of state for the specific internal energy and temperature are employed to close the system of balance laws. With respect to other approaches known in the kinetic literature for detonation problems with a reversible reaction, this paper aims to improve some aspects of the wave solution. Within the mathematical analysis of the detonation model, the equation of the equilibrium Hugoniot curve of the final states is explicitly derived for the first time and used to define the correct location of the equilibrium Chapman–Jouguet point in the Hugoniot diagram. The parametric space is widened to investigate the response of the detonation solution to the activation energy of the chemical reaction. Finally, the mathematical formulation of the linear stability problem is given for the wave detonation structure via a normal-mode approach, when bidimensional disturbances perturb the steady solution. The stability equations with their boundary conditions and the radiation condition of the considered model are explicitly derived for small transversal deviations of the shock wave location. The paper shows how a second-order chemical kinetics description, derived at the microscopic level, and an analytic deduction of the equilibrium Hugoniot curve, lead to an accurate picture of the steady detonation with reversible reaction, as well as to a proper bidimensional linear stability analysis.Brazilian Research Council (CNPq), by Italian Research Council GNFM-INdAM, and by the Research Centre of Mathematics of the University of Minho with the Portuguese Funds of FCT, project PEstOE/MAT/UI0013/2014

Neutrino Anomalies without Oscillations

I review explanations for the three neutrino anomalies (solar, atmospheric and LSND) which go beyond the ``conventional'' neutrino oscillations induced by mass-mixing. Several of these require non-zero neutrino masses as well.Comment: 14pages, LATEX format, 3 figure

Energy Independent Solution to the Solar Neutrino Anomaly including the SNO data

The global data on solar neutrino rates and spectrum, including the SNO charged current rate, can be explained by LMA, LOW or the energy independent solution -- corresponding to near-maximal mixing. All the three favour a mild upward renormalisation of the Cl rate. A mild downward shift of the $B$ neutrino flux is favoured by the energy independent and to a lesser extent the LOW solution, but not by LMA. Comparison with the ratio of SK elastic and SNO charged current scattering rates favours the LMA over the other two solutions, but by no more than $1.5\sigma$.Comment: 18 pages, latex, 3 figure