Climate and CO2 saturation in an alpine lake throughout the Holocene

This study shows that diatom sediment records can be used to investigate the long-term inorganic carbon dynamics in oligotrophic and poorly acid-buffered lakes. Using a training set of 115 high-mountain lakes in the Pyrenees, we found that both alkalinity and potential hydrogen (pH) independently explained some of the variability in diatom assemblages. Transfer functions for both variables were developed and applied to a Holocene record from Lake Redon and CO2 changes calculated. CO2 saturation broadly followed alkalinity, which in turn was related to summer and autumn air-temperature fluctuations. In general, warmer climate during the ice-free period led to higher supersaturation, due to increased alkalinity, which facilitated retention of CO2 from respiration, and decreased primary production (assessed by diatom fluxes). Only during the early Holocene, there were periods of extreme undersaturation, corresponding to cold periods of low alkalinity (<20 microequivalents per liter [meq L21]), and suggesting carbon limitation of primary production. The winter and spring climate, which determines the ice cover duration, appears to be relevant for CO2 saturation only during periods when the organic-matter content of the sediments was low (,22%). Longer periods of ice cover led to lower lake CO2 saturation, suggesting that the ice cover influence on internal nutrient loading may regulate lake productivity fluctuations under low allocthonous nutrient and organic-matter inputs. Alkalinity ,20 meq L21 and sediment organic matter ,22% appear as critical thresholds in the way lake CO2 levels respond to climate fluctuations.Peer ReviewedPostprint (published version

Proposal of a new erythemal UV radiation amplification factor

International audienceThis work is aimed to propose a natural expansion of radiation amplification factor (RAF) for erythemal irradiance to consider all solar zenith angles cases together. In this direction, the article analyzes the relationship between measurements of UV erythemal radiation (UVER) recorded at Badajoz (Spain) and the total ozone column estimated by the instrument TOMS/NASA for that location during the period February 2001?December 2005. The new RAF parameter is formulated by power equation using slant ozone and UVER atmospheric transmissivity values. Thus, reliable values of this parameter have been reported. These values could serve as a new relevant index for comparison with other studies and model's result. The new RAF is calculated with measurements recorded during completely clear cases using clearness index values higher than 0.75. The RAF value was 1.35±0.01, it is to say, when the slant ozone amount decreases 1% at Badajoz, UVER atmospheric transmissivity values and, therefore, UVER surface values approximately increase 1.35%. This result emphasizes the interest of measuring and monitoring simultaneous measurements of UV radiation and stratospheric ozone even for mid-latitudes. The influence of total ozone amount and cloudiness changes on new RAF values is analyzed. Cloud-free conditions allow to study the ozone influences while cloud effects are analyzed with all data by means of monthly average of slant ozone and UVER atmospheric transmissivities values

Defining a methodology to design and implement business process models in BPMN according to the standard ANSI/ISA-95 in a manufacturing enterprise

Nowadays, extended enterprise requires flexible and adaptable platforms which enable technology and internal integration between ERP and MES levels of manufacturing industry. Under the EAI perspective, it is proposed the use of ESB and BPMS technologies to improve integration between business and manufacturing layers. In order to enable this integration, it should be considered standard ANSI/ISA-95 Enterprise/Control System Integration due to it defines an effective model for business integration/manufacturing. In this paper, in order to develop applications that allow the orchestration of information exchanges between ERP/MES, a methodology is defined to design BPMN process models according to the standard ANSI/ISA-95 because it enables B2M integration projects development

Monitoring and management of Pyrenean chamois in Aragon

8 páginasPeer reviewe

Trophic ecology and morphology of Anolis bartschi (Squamata: Dactyloidae) in Viñales National Park, Cuba

Ecología trófca y morfología de Anolis bartschi (Squamata: Dactyloidae) en el Parque Nacional Viñales, Cuba. Se conoce poco sobre la dieta de los anolinos cubanos. La morfología en lagartos está directamente relacionada con funciones ecológicas, como estrategias de forrajeo, competencias interespecífcas, o demanda energética ligada a la reproducción. Anolis bartschi es un endémico regional, restringido a las alturas cársicas del occidente de Cuba. Aquí ofrecemos datos nuevos sobre la ecología trófca de esta especie y su relación con la morfología de su cabeza. Se capturaron 131 individuos adultos, donde los machos poseen mayor tamaño del cuerpo y de la cabeza que las hembras. La mayoría de los individuos tenía presas en el estómago. Los machos consumirán más presas que las hembras, pero de menor tamaño que estas. Se detectó solapamiento trófco en época de seca, pero hubo segregamiento trófco en lluvia. Hymenoptera fue la presa más consumida por ambos sexos. Además, las hembras consumieron más Blattodea y Coleoptera, mientras los machos más Diptera. Esta especie prefere presas sedentarias en lugar de móviles. Sugerimos que esta especie prefere presas sedentarias a presas móviles. De acuerdo a nuestros datos y las observaciones de campo, A. bartschi es un forrajeador bimodal, aunque se recomiendan futuras investigaciones sobre la variación temporal (diaria y anual) en la dieta de esta especie para una apropiada clasifcación sobre su actividad forrajeadoraTrophic ecology and morphology of Anolis bartschi (Squamata: Dactyloidae) in Parque Nacional Viñales, Cuba. Little is known about the trophic ecology of most anoles of Cuba. Morphology is directly related to ecological functions in lizards, such as feeding strategies, interspecifc competition or energetic demands linked to reproduction. Anolis bartschi is a regionally endemic species, restricted to karstic hills of western Cuba. Here, we offer new insights into the trophic ecology of this species, and its relation to head morphology. We captured 131 adults; males were larger than females in size and head width. Most of them had prey in their stomachs. Males consumed more prey than females, but the latter consumed larger prey. Prey overlap within sexes was detected in the dry season, but trophic segregation occurred in the rainy season. Hymenoptera was the most frequently consumed prey in both sexes. In addition, females ate Blattodea and Coleoptera, and males consumed more Diptera. We suggest that this lizard prefers sedentary rather than mobile prey. According to our dataset and feld observations, A. bartschi is a bimodal forager lizard, but research on temporal (daily and annual) variation in diet is recommended for a proper forage classifcation of this lizard

Improving the solar zenith angle dependence of broadband UV radiometers calibration

International audienceThis paper focusses on the proposal of a new method for the calibration of broadband ultraviolet radiometers. The advantage of the method proposed is the accurate modelling of the dependence on the solar zenith angle. The new model is compared with other one-step calibration methods and with the two-step method, which requires the knowledge of the actual response of the broadband radiometer. For this purpose, three broadband radiometers are calibrated against a spectrophotometer of reference. The new method is validated comparing its predictions with the spectrophotometer measurements using an independent data set

Integral field spectroscopy of the central regions of 3C 120: Evidence of a past merging event

Optical integral field spectroscopy (IFS), combined with Hubble Space Telescope (HST ) WFPC imaging, was used to characterize the central regions of the Seyfert 1 radio galaxy 3C 120. We carried out the analysis of the data, deriving intensity maps of different emission lines and the continua at different wavelengths from the observed spectra. Applying a two-dimensional modeling to the HST images, we decoupled the nucleus and the host galaxy and analyzed the host morphology. The host is a highly distorted bulge-dominated galaxy, rich in substructures. We developed a new technique to model the IFS data extending the two-dimensional modeling (hereafter threedimensional modeling). Using this technique, we separated the Seyfert nucleus and the host galaxy spectra and derived a residual data cube with spectral and spatial information of the different structures in 3C 120. Three continuum-dominated structures (named A, B, and C) and three other extended emission-line regions (EELRs, named E1, E2, and E3) are found in 3C 120, which does not follow the general behavior of a bulge-dominated galaxy. We also found shells in the central kiloparsec that may be remnants of a past merging event in this galaxy. The origin of E1 is most probably due to the interaction of the radio jet of 3C 120 with the intergalactic medium (Axon et al. 1989; Sa´nchez et al. 2004a). Structures A, B, and the shell at the southeast of the nucleus seem to correspond to a larger morphological clumpy structure that may be a tidal tail, a consequence of the past merging event. We found a bright EELR (E2) in the innermost part of this tidal tail, nearby the nucleus, which shows a high ionization level. The kinematics of the E2 region and its connection to the tidal tail suggest that the tail has channeled gas from the outer regions to the cente

Analysis of a low ozone episode over Extremadura (Spain) in January 2006 and its influence on UV radiation

The main objectives of this work are to analyze, firstly, the detail of the causes of a low ozone event which occurred in January 2006 and, secondly, the related effects of this anomalous episode on ultraviolet (UV) radiation measured at three locations in Extremadura (South-Western Spain). On 19 January 2006, the OMI total ozone column (TOC) was 16&amp;ndash;20% below the January mean value of TOMS/NASA TOC (period 1996&amp;ndash;2005). The back trajectories analysis with the HYSplit model indicates that the notable decrease of TOC could be attributed to a fast rise of the isentropic trajectories height. Concomitantly, UV erythemal radiation greatly increases (between 23% and 37%) on 19 January 2006 respect to UV erythemal radiation measured on 19 January 2005. This notable increase in winter UV solar radiation may involve harmful effects for organisms adapted to receive less radiation during that season (e.g. early developmental stages of terrestrial plants and phytoplankton)