Movement between crops and weeds: temporal refuges for aphidophagous insects in Central Chile

Villegas, CM (Villegas, Cinthya M.)[ 1 ] ; Verdugo, JA (Verdugo, Jaime A.)[ 1,3 ] ; Tapia, J (Tapia, Jaime)[ 2 ] ; Lavandero, B (Lavandero, Bias)[ 1 ].1 ] Univ Talca, Inst Biol Vegetal & Biotecnol, Talca, Chile.2 ] Univ Talca, Inst Quim Recursos Nat, Talca, ChileCrop edges have significant effects on populations of natural enemies, acting as source or sink habitats during the growing season. Previous observations have shown that coccinellid species are associated with thistle (Sylibum marianum (L.) Gaertn), a common exotic weed in the central valley of Chile. To determine whether thistles growing at crop edges act as a putative refuge for natural enemies, the seasonal relative abundance of aphidophagous coccinellids was estimated at 0, 10 and 25 m from the edges of three alfalfa fields. Mark-recapture studies were carried out using the trace element rubidium (Rb) to determine whether coccinellids moved between the edges and the alfalfa. The most common aphidophagous coccinellid species were Hippodamia convergens (63%), H. variegata (11%), Rhyzobius lophantae (4%) and Adalia angulifera (4%). In mid-November, the abundance of coccinellids at the edge of (0 m from the edge) the alfalfa plot increased compared to that at the center of the field (25 m from the edge), coinciding with a reduction in the population of aphids at all sampling points. Of the coccinellids captured at the thistle edge, 68% were marked with rubidium, suggesting movement of coccinellids from the alfalfa plot to the thistle growing at its edges. After the thistles were removed, coccinellids returned to the crop, as shown by the presence of marked coccinellids within the alfalfa fields at all three sampling distances. The results of this study suggest that thistles can act as a refuge for coccinellids when aphids are not available in the alfalfa fields

Volcanic sequence in Late Triassic – Jurassicsiliciclastic and evaporitic rocks from Galeana, NE Mexico

In northeastern Mexico, volcanic rocks interbedded with Late Triassic–Jurassic siliciclastic and evaporitic strata have been linked to magmatic arcs developed in the Pangea western margin during its initial phase of fragmentation. This work provides new petrographic and geochemical data for volcanism included in the El Alamar and Minas Viejas formations outcropping in the Galeana region. Andesitic dykes and sills (n= 10) in the El Alamar redbeds show SiO2= 47.5–59.1% and MgO= 1.2–4.2%, as well as a geochemical affinity to island arc magmas. This work represents the first report of this tectonic setting in the region. Geological and petrographic evidence suggest that this arc system likely developed after ~220 and before ~193Ma. Trachy-andesitic and rhyodacitic domes (n= 20) associated with the Minas Viejas gypsum-carbonates sequence show SiO2= 61.8–82.7% and MgO= 0.1–4.0% with a tectonic affinity to continental arc. A rhyodacite sample from this region has been dated by U-Pb in zircon, yielding an age of 149.4 ± 1.2Ma (n= 21), being the youngest age related to this arc. Finally, we propose a threestep model to explain the tectonic evolution from Late Triassic island arc to Jurassic continental arc system in the northeastern Mexico

Characterization of a putative grapevine Zn transporter, VvZIP3, suggests its involvement in early reproductive development in Vitis vinifera L

Gonzalez, E (reprint author), Univ Talca, Inst Biol Vegetal & Biotecnol, Talca, Chile.Background: Zinc (Zn) deficiency is one of the most widespread mineral nutritional problems that affect normal development in plants. Because Zn cannot passively diffuse across cell membranes, it must be transported into intracellular compartments for all biological processes where Zn is required. Several members of the Zinc-regulated transporters, Iron-regulated transporter-like Protein (ZIP) gene family have been characterized in plants, and have shown to be involved in metal uptake and transport. This study describes the first putative Zn transporter in grapevine. Unravelling its function may explain an important symptom of Zn deficiency in grapevines, which is the production of clusters with fewer and usually smaller berries than normal. Results: We identified and characterized a putative Zn transporter from berries of Vitis vinifera L., named VvZIP3. Compared to other members of the ZIP family identified in the Vitis vinifera L. genome, VvZIP3 is mainly expressed in reproductive tissue - specifically in developing flowers - which correlates with the high Zn accumulation in these organs. Contrary to this, the low expression of VvZIP3 in parthenocarpic berries shows a relationship with the lower Zn accumulation in this tissue than in normal seeded berries where its expression is induced by Zn. The predicted protein sequence indicates strong similarity with several members of the ZIP family from Arabidopsis thaliana and other species. Moreover, VvZIP3 complemented the growth defect of a yeast Zn-uptake mutant, ZHY3, and is localized in the plasma membrane of plant cells, suggesting that VvZIP3 has the function of a Zn uptake transporter. Conclusions: Our results suggest that VvZIP3 encodes a putative plasma membrane Zn transporter protein member of the ZIP gene family that might play a role in Zn uptake and distribution during the early reproductive development in Vitis vinifera L., indicating that the availability of this micronutrient may be relevant for reproductive development

Impact of manufacturing tolerances on axial flux permanent magnet machines with ironless rotor core: a statistical approach

Axial Flux Permanent Magnet (AFPM) machines with ironless rotors are an attractive and recently studied solution in low-speed applications, due to their potentially high power/weight ratio, high aspect ratio, and high efficiency. Nevertheless, these machines are prone to be affected by manufacturing tolerance during its fabrication process and consequently, the magnets may move freely inside the rotor structure. This work presents a statistical analysis of manufacturing tolerances of an AFPM machine with an ironless rotor, considering several magnet fault types. A computationally efficient superposition method is developed and implemented to obtain both the cogging torque and rated torque considering several tolerance combinations with acceptable accuracy. The results obtained from a statistical analysis of 10,000 designs of a two-stator one rotor tooth coil winding AFPM (TCW-AFPM) machine allowed us to identify the parameters with the most impact on relevant performance indicators and disclosed a substantial increase in cogging and ripple torque when unavoidable combined tolerances are present

Seguimiento del proceso de forestación del 2005 al 2010 en el Campus UAZ Siglo XXI

La Universidad Autónoma de Zacatecas es la Institución educativa más importante del Estado de Zacatecas, fundada en 1778 como Real Colegio de San Luis Gonzaga, hasta que durante el período gubernamental del ingeniero José Isabel Rodríguez Elías, se permitió que el Instituto de Ciencias Autónomo de Zacatecas, mediante decreto del 6 de septiembre de 1968, el ejecutivo del Estado lo transformara en la Universidad Autónoma de Zacatecas. En los primeros años como universidad, la institución, al lado de un proceso vertiginoso de desarrollo, muestra en su interior una dinámica de discusión y análisis de sus estructuras, organización, funcionamiento, contenidos, metodología y técnicas de la enseñanza, vinculación con los sectores desprotegidos de la sociedad, entre otros. En 1999-2000 se realizó el Foro General de Reforma, con una amplia participación de la Comunidad Universitaria, logrando consensar resolutivos que fueron aprobados por el H. Consejo Universitario, que derivaron en los lineamientosgenerales para el actual modelo académico UAZ Siglo XXI.Universidad Nacional de La Plat

Application of microsatellite markers to the management of farmed stocks of turbot Scophthalmus maximus (L., 1758)

In the present study, eight microsatellite loci were used to estimate genetic relatedness and pedigree determination in turbot Scophthalmus maximus (L., 1758). Through genotypic analysis of broodstocks and their progenies, from two different turbot hatcheries, the capacity of these loci to correctly classify individuals as related or non-related was examined. Relatedness coefficients among related and non-related individuals presented means close to those theoretically expected, and the percentages of related individuals included in all relatedness coefficients found to be below the R = 0 value ranged from 0% (hatchery A) to 29 % (hatchery B). The identification of both parents for each individual was possible in more than 80 % of the cases from hatchery A, but only 41% of those from hatchery B.Se utilizaron ocho loci microsatélites en la estimación de relaciones genéticas y determinación de pedigríes en rodaballo Scophthalmus maximus (L., 1758). Mediante el análisis de los genotipos de reproductores y descendientes de dos piscifactorías se investigó la capacidad de los loci para clasificar correctamente a los individuos como emparentados o no. Las distribuciones de los coeficientes de relación genética (R) entre individuos emparentados y no relacionados exhiben medias cercanas a las esperadas teóricamente y el porcentaje de individuos emparentados que forman el total de coeficientes de relación genética que se encuentran por debajo del valor R = 0 oscilan entre el 0 % (estación A) y el 29 % (estación B). Así mismo, la identificación correcta de ambos parentales para cada descendiente fue posible en más del 80 % de los casos en la estación A y en sólo el 41 % en la estación B.Instituto Español de Oceanografí

Evolution of growth rates in triploid and diploid turbot Scophthalmus maximus (L., 1758)

El crecimiento de los peces triploides de diversas especies ha sido objetivo de múltiples trabajos cuyos resultados no indican una pauta sostenida de comportamiento en cuanto a esta variable, obteniéndose a menudo resultados contradictorios, incluso entre individuos de la misma especie. En este trabajo se analizan las tasas de crecimiento de dos grupos de individuos triploides de rodaballo Scophthalmus maximus (L., 1758) producidos mediante la técnica de choques térmicos fríos en distintos momentos y procedentes de diferentes stocks reproductores. Los datos indican que no hay diferencias entre los diploides y los triploides y, además, que las similitudes son mayores entre cada grupo y su control que entre los grupos del mismo[Abstract] The literature on the growth rates of triploid fish before reaching maturity is inconclusive, often reporting contradictory results, even between individuals of the same species. The present paper analyses the growth rate of two groups of diploid and triploid turbot Scophthalmus maximus (L., 1758). The triploids were produced through the technique of thermal cold shocks. The specimens originated from two different broodstocks. No differencesInstituto Español de Oceanografí

REALISTIC MODELS WITH A LIGHT U(1) GAUGE BOSON COUPLED TO BARYON NUMBER

We recently showed that a new gauge boson $\gamma_B$ coupling only to baryon number is phenomenologically allowed, even if $m_B<m_Z$ and $\alpha_B \approx 0.2$. In our previous work we assumed that kinetic mixing between the baryon number and hypercharge gauge bosons (via an $F^{\mu\nu}_B F_{\mu\nu}^Y$ term) was small enough to evade constraints from precision electroweak measurements. In this paper we propose a class of models in which this term is naturally absent above the electroweak scale. We show that the generation of a mixing term through radiative corrections in the low-energy effective theory does not lead to conflict with precision electroweak measurements and may provide a leptonic signal for models of this type at an upgraded Tevatron.Comment: 21 pages, LaTeX, 4 figures in a uuencoded compressed postscript file

Turn-turn short circuit fault management in permanent magnet machines

This paper presents a systematic study on turn-turn short circuit fault and ways to manage them to provide a basis for comparison of the various options available. The possible methods to reduce the likelihood of the winding SC fault and the fault mitigation techniques related to such faults are discussed. A Finite Element (FE) analysis of a surface-mount Permanent Magnet (PM) machine under application of different mitigation techniques during a turn-turn fault is presented. Both machine and drive structural adaptations for different fault mitigation techniques are addressed. Amongst the investigated fault mitigation techniques, the most promising solution is identified and validated experimentally. It is shown that the shorting terminal method adopting vertical winding arrangement is an effective method in terms of the implementation, reliability and weight