Fenología reproductiva de Stenocereus thurberi (Cactaceae) en una región de transición del norte de Sinaloa, México

Phenological patterns, which are molded by physical and biotic interactions, in marginal habitats could reveal peculiar characteristics for the permanence of a population. Phenology of Stenocereus thurberi, a columnar cactus from the Sonoran Desert, has shown geographic variation that is associated with the weather and pollinators, however, there is no information regarding its behavior in habitats that are more humid than its core distribution area. The aim of this study was to describe the reproductive dynamics and the size structure of three populations along a scrub-tropical dry forest transition 170 km in length. Plants were characterized by height, coverage and number of stems. Phenological stages were based on the Campbell scale and were registered fortnightly on 50 individuals from each population. We found differences in the individual architecture, plant size distribution and reproductive activity. Canopy structure in plants from the coastal population (Plan de Guadalupe, 244 mm) is more branched (23.3 ± 3.0 stems/plant) and wider (4.6 ± 0.7 m2) than the population from the deciduous forest (Las Cruces, 830 mm), on which plants showed higher vertical development (9.3 ± 1.3 stems / plant, 1.2 ± 0.2 m2). Populations exhibited differences in the size structure, with bigger plants on the coast than the other populations. Timing of the breeding season was delayed 15-30 days and was extended four more weeks in the coast than in the other populations. Production of reproductive structures in peak dates showed highly significant differences (F = 31.68, p< 0.001), with a mean of 69.5 ± 8.7 in the coast, 28.3 ± 3.2 in Buenavista and 16.6 ± 5.4 in Las Cruces. Rainfall and temperature are key determinants in the production of reproductive structures and in the size structure of the local populations. It is likely that the low production of pitaya flowers and fruits in the deciduous forest be a consequence of high abortion rates, predation of structures and light competition, while pollination is improved by facilitation from other columnar cactus, Stenocereus montanus.Los patrones fenológicos, moldeados por las interacciones físicas y bióticas en hábitats marginales, pueden revelar características únicas para la permanencia de una población. La fenología de Stenocereus thurberi, una cactácea columnar del Desierto Sonorense, ha mostrado variación geográfica asociada con el clima y los polinizadores, pero no se conoce su comportamiento en ambientes más húmedos de su área de distribución. El objetivo de esta investigación es describir la dinámica reproductiva y la estructura de tamaños de tres poblaciones en una transición matorral-bosque caducifolio de 170 km de longitud. Las plantas se caracterizaron por su talla, cobertura y número de tallos; los estados fenológicos se basaron en la escala de Campbell y se registraron quincenalmente en 50 individuos de cada población. Se encontraron diferencias en la arquitectura de las plantas, la distribución de tamaños y la actividad reproductiva. El dosel individual en plantas de la población costera (Plan de Guadalupe, 244 mm) es más ramificado (23.3 ± 3.0 tallos / planta) y más extendido (4.6 ± 0.7 m2 ; media ± 1 error estándar) que en el bosque caducifolio (Las Cruces, 830 mm), cuyas plantas tuvieron mayor desarrollo vertical (9.3 ± 1.3 tallos / planta, 1.2 ± 0.2 m2). Las poblaciones mostraron diferencias en la estructura de tamaños, con plantas más grandes en la costa que en las otras poblaciones. El calendario del periodo reproductivo se demoró 15-30 días y se prolongó por cuatro semanas más en la costa que en las otras poblaciones. La producción de estructuras reproductivas en fechas pico mostró diferencias altamente significativas (F = 31.68, p< 0.001), con medias de 69.5 ± 8.7 en la costa, 28.3 ± 3.2 en Buenavista y 16.6 ± 5.4 en Las Cruces. La precipitación y la temperatura son determinantes en la producción de estructuras reproductivas y la estructura de tamaños de las poblaciones locales. Es posible que la baja producción de flores y frutos de pitaya en el bosque caducifolio sea consecuencia de altas tasas de aborto, depredación de estructuras y competencia por luz, mientras la polinización es facilitada por coexistencia con otra especie columnar, Stenocereus montanus

CALIFA, the Calar Alto Legacy Integral Field Area survey: I. Survey presentation

We present here the Calar Alto Legacy Integral Field Area (CALIFA) survey, which has been designed to provide a first step in this direction.We summarize the survey goals and design, including sample selection and observational strategy.We also showcase the data taken during the first observing runs (June/July 2010) and outline the reduction pipeline, quality control schemes and general characteristics of the reduced data. This survey is obtaining spatially resolved spectroscopic information of a diameter selected sample of $\sim600$ galaxies in the Local Universe (0.005< z <0.03). CALIFA has been designed to allow the building of two-dimensional maps of the following quantities: (a) stellar populations: ages and metallicities; (b) ionized gas: distribution, excitation mechanism and chemical abundances; and (c) kinematic properties: both from stellar and ionized gas components. CALIFA uses the PPAK Integral Field Unit (IFU), with a hexagonal field-of-view of \sim1.3\sq\arcmin', with a 100% covering factor by adopting a three-pointing dithering scheme. The optical wavelength range is covered from 3700 to 7000 {\AA}, using two overlapping setups (V500 and V1200), with different resolutions: R\sim850 and R\sim1650, respectively. CALIFA is a legacy survey, intended for the community. The reduced data will be released, once the quality has been guaranteed. The analyzed data fulfill the expectations of the original observing proposal, on the basis of a set of quality checks and exploratory analysis. We conclude from this first look at the data that CALIFA will be an important resource for archaeological studies of galaxies in the Local Universe.Comment: 32 pages, 29 figures, Accepted for publishing in Astronomy and Astrophysic

Power TAC 2012: Agent Technologies for the Smart Grid

Intelligent agents are a critical technology in managing the increasingly complex and decentralized energy systems that are evolving. These technologies, often called the smart grid, have the potential to improve the efficiency and reliability of future energy markets. This project focuses on developing a trading agent to compete in the 2012 Power TAC game, a new scenario this year that is part of the annual Trading Agent Competition. Modeling a liberalized retail electrical energy market, Power TAC is a simulation in which competing trading agents or brokers offer energy services to customers via tariff contracts. The brokers must also serve their customers by buying and selling energy in the wholesale and retail markets. Our agent design uses a feedback control mechanism to coordinate the agent’s actions across different markets and maintain the necessary energy balance. The agent predicts future energy supply and demand conditions based on its portfolio, and, if necessary, applies corrective actions. In the retail market, the agent can create and modify tariff offers to customers to increase or decrease demand, while in the wholesale market the agent can negotiate with suppliers to buy additional energy. The results of the competition and the design of agent strategies will help policy makers create institutions that produce the intended incentives for energy customers and consumers, and help to validate intelligent automation technologies for next-generation energy markets

EL DESTETE PRECOZ COMO UNA HERRAMIENTA PARA INCREMENTAR LA RENTABILIDAD EN LOS RANCHOS GANADEROS DE SONORA, MÉXICO

This study was created at Carbó, Sonora, México, during 2006 to determine calf production strategies evaluating: 1) Early weaning (EW), 2) Creep feeding (CF) and 3) Control (C), and to analyze benefice-cost and their profitability. Sixty animals were randomly selected from a 5 year old Charbray cow group that calved among the 15 and 20 of June 2006. For each treatment, 20 animals were grouped, 10 males and 10 females. Evaluated variables were: (1) Calf birth weight, (2) Cow weight and body condition at calving, (3) calf weight at calving, (4) Calf selling weight; (5) Weight and cow condition at calving, (7) Calf production costs and (8) Profitability projection with the three sceneries indicated. Evaluated variables were analyzed by ANOVA (P<0.05). Some financial runs were made on a computer with software for analysis and evaluation of beef inversion projects. Average calf daily gains were 1.32, 1.13 and 0.43 kg/animal/day for EW, CF and the control, treatments, respectively. Cow pregnancy percentage was 95, 85 and 75 and the number of open days was 90, 165 y 240, for treatments EW, CF and (C), respectively. Control treatment yielded negative profits during the 10 projected years. In CF, although gains were low during the first two years, these varied from $54,486 to$69,453 from year there to tenth. With EW the best results were obtained with annual gains starting at the third year and varied from $108,571 a$119,782. Both EW as well as CF shows a viable alternative to increase ranch productivity and ratability. Results from the financial analyses show that the greatest benefit was obtained with EW because it allows for calf production in a continuous way during the 10 years of the project as compared to (CF) and (C); which show out of phase in the production cycles originated by the large number of open days between calving, low pregnancy percentages, and high production costs

Is the N-Back Task a Valid Neuropsychological Measure for Assessing Working Memory?

The n-back is a putative working memory task frequently used in neuroimaging research; however, literature addressing n-back use in clinical neuropsychological evaluation is sparse. We examined convergent validity of the n-back with an established measure of working memory, digit span backward. The relationship between n-back performance and scores on measures of processing speed was also examined, as was the ability of the n-back to detect potential between-groups differences in control and Parkinson's disease (PD) groups. Results revealed no correlation between n-back performance and digit span backward. N-back accuracy significantly correlated with a measure of processing speed (Trail Making Test Part A) at the 2-back load. Relative to controls, PD patients performed less accurately on the n-back and showed a trend toward slower reaction times, but did not differ on any of the neuropsychological measures. Results suggest the n-back is not a pure measure of working memory, but may be able to detect subtle differences in cognitive functioning between PD patients and controls