2,766 research outputs found
Rhodoliths and rhodolith beds
Rhodolith (maërl) beds, communities dominated by free living coralline algae, are
a common feature of subtidal environments worldwide. Well preserved as fossils, they have long
been recognized as important carbonate producers and paleoenvironmental indicators. Coralline
algae produce growth bands with a morphology and chemistry that record environmental variation.
Rhodoliths are hard but often fragile, and growth rates are only on the order of mm/yr. The
hard, complex structure of living beds provides habitats for numerous associated species not found
on otherwise entirely sedimentary bottoms. Beds are degraded locally by dredging and other anthropogenic
disturbances, and recovery is slow. They will likely suffer severe impacts worldwide
from the increasing acidity of the ocean. Investigations of rhodolith beds with scuba have enabled
precise stratified sampling that has shown the importance of individual rhodoliths as hot spots of
diversity. Observations, collections, and experiments by divers have revolutionized taxonomic studies
by allowing comprehensive, detailed collection and by showing the large effects of the environment
on rhodolith morphology. Facilitated by in situ collection and calibrations, corallines are now
contributing to paleoclimatic reconstructions over a broad range of temporal and spatial scales.
Beds are particularly abundant in the mesophotic zone of the Brazilian shelf where technical diving
has revealed new associations and species. This paper reviews selected past and present research on
rhodoliths and rhodolith beds that has been greatly facilitated by the use of scuba
The static allometry of sexual and non-sexual traits in vervet monkeys
Sexual traits vary tremendously in static allometry. This variation may be explained in part by body size-related differences in the strength of selection. We tested this hypothesis in two populations of vervet monkeys, using estimates of the level of condition dependence for different morphological traits as a proxy for body size-related variation in the strength of selection. In support of the hypothesis, we found that the steepness of allometric slopes increased with the level of condition dependence. One trait of particular interest, the penis, had shallow allometric slopes and low levels of condition dependence, in agreement with one of the most consistent patterns yet detected in the study of allometry, namely that of genitalia exhibiting shallow allometries.This research was supported by NIH grant R01RR0163009
3D high definition video coding on a GPU-based heterogeneous system
H.264/MVC is a standard for supporting the sensation of 3D, based on coding from 2 (stereo) to N views. H.264/MVC adopts many coding options inherited from single view H.264/AVC, and thus its complexity is even higher, mainly because the number of processing views is higher. In this manuscript, we aim at an efficient parallelization of the most computationally intensive video encoding module for stereo sequences. In particular, inter prediction and its collaborative execution on a heterogeneous platform. The proposal is based on an efficient dynamic load balancing algorithm and on breaking encoding dependencies. Experimental results demonstrate the proposed algorithm's ability to reduce the encoding time for different stereo high definition sequences. Speed-up values of up to 90× were obtained when compared with the reference encoder on the same platform. Moreover, the proposed algorithm also provides a more energy-efficient approach and hence requires less energy than the sequential reference algorith
Extreme flood events at higher temperatures exacerbate the loss of soil functionality and trace gas emissions in grassland
Validation of a personal control scale: A specific measure of perceived control expectations in job search
[ES]Los técnicos en orientación profesional necesitan herramientas especializadas para medir la motivación de búsqueda de empleo. Entre los elementos que motivan a una persona a buscar trabajo destacan sus expectativas. Con el objetivo de evaluarlas, se creó la escala de Expectativas de Control Percibido de Búsqueda de Empleo (ECPBE) partiendo del modelo de Expectativas Generalizadas de Control (EGC) de Palenzuela. Se estudia la validez convergente-discriminante, la fiabilidad (consistencia interna y homogeneidad) y la validez factorial. Se obtienen correlaciones con las subescalas próximas teóricamente significativas y se confirma la presencia de cuatro factores para los ítems de autoeficacia, expectativas de éxito, locus de control interno y locus de control externo. Se puede considerar la ECPBE como una escala válida para medir las expectativas propuestas desde el modelo de EGC adaptado a la situación de búsqueda de empleo, presentando un adecuado nivel de homogeneidad y consistencia en la medida. [EN] Experts in career guidance need specialised tools to measure motivation for job search. Among the remarkable elements that motivate a person to search for a job are their own expectations. Aiming at evaluating expectations, the Perceived Control Expectations in Job Search (PCEJS) scale has been created based on Palenzuela's model of Generalized Expectancies of Control (GEC). Convergent-discriminant validity, reliability (internal consistency and homogeneity), and factorial validity are addressed in this study. Correlations are found among theoretically closed sub-scales, and the presence of 4 factors for the items of self-efficacy, expectations of success, internal locus of control and external locus of control is substantiated. The PCEJS can be considered a valid scale to measure expectations as proposed by the GEC model when adapted to a job search situation, showing an appropriate level of homogeneity and consistency in the measurement
Modelling the Inorganic Bromine Partitioning in the Tropical Tropopause over the Pacific Ocean
The stratospheric inorganic bromine burden (Bry) arising from the degradation of brominated very short-lived organic substances (VSL org ), and its partitioning between reactive and reservoir species, is needed for a comprehensive assessment of the ozone depletion potential of brominated trace gases. Here we present modelled inorganic bromine abundances over the Pacific tropical tropopause based on aircraft observations of VSL org of two campaigns of the Airborne Tropical TRopopause EXperiment (ATTREX 2013 carried out over eastern Pacific and ATTREX 2014 carried out over the western Pacific) and chemistry-climate simulations (along ATTREX flight tracks) using the specific meteorology prevailing. Using the Community Atmosphere Model with Chemistry (CAM-Chem), we model that BrO and Br are the daytime dominant species. Integrated across all ATTREX flights BrO represents ~ 43 % and 48 % of daytime Bry abundance at 17 km over the Western and Eastern Pacific, respectively. The results also show zones where Br/BrO >1 depending on the solar zenith angle (SZA), ozone concentration and temperature. On the other hand, BrCl and BrONO 2 were found to be the dominant night-time species with ~ 61% and 56 % of abundance at 17 km over the Western and Eastern Pacific, respectively. The western-to-eastern differences in the partitioning of inorganic bromine are explained by different abundances of ozone (O3), nitrogen dioxide (NO2) , and total inorganic chlorine (Cly).Fil: Navarro, María A.. University of Miami; Estados UnidosFil: Saiz-lopez, Alfonso. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Cuevas, Carlos Alberto. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Fernandez, Rafael Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales; Argentina. Universidad Tecnologica Nacional. Facultad Regional Mendoza. Secretaría de Ciencia, Tecnología y Postgrado; ArgentinaFil: Atlas, Elliot. University of Miami; Estados UnidosFil: Rodriguez Lloeveras, Xavier. Consejo Superior de Investigaciones Científicas. Instituto de Química Física; EspañaFil: Kinnison, Douglas E.. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Lamarque, Jean Francois. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Tilmes, Simone. National Center For Atmospheric Research. Amospheric Chemistry División; Estados UnidosFil: Thornberry, Troy. State University of Colorado at Boulder; Estados Unidos. Earth System Research Laboratory; Estados UnidosFil: Rollins, Andrew. State University of Colorado at Boulder; Estados Unidos. Earth System Research Laboratory; Estados UnidosFil: Elkins, James W.. Earth System Research Laboratory; Estados UnidosFil: Hintsa, Eric J.. State University of Colorado at Boulder; Estados Unidos. Earth System Research Laboratory; Estados UnidosFil: Moore, Fred L.. State University of Colorado at Boulder; Estados Unidos. Earth System Research Laboratory; Estados Unido
Cognitive Phenotypes and the Evolution of Animal Decisions
Despite the clear fitness consequences of animal decisions, the science of animal decision making in evolutionary biology is underdeveloped compared with decision science in human psychology. Specifically, the field lacks a conceptual framework that defines and describes the relevant components of a decision, leading to imprecise language and concepts. The ‘judgment and decision-making’ (JDM) framework in human psychology is a powerful tool for framing and understanding human decisions, and we apply it here to components of animal decisions, which we refer to as ‘cognitive phenotypes’. We distinguish multiple cognitive phenotypes in the context of a JDM framework and highlight empirical approaches to characterize them as evolvable traits
Cognitive Phenotypes and the Evolution of Animal Decisions
Despite the clear fitness consequences of animal decisions, the science of animal decision making in evolutionary biology is underdeveloped compared with decision science in human psychology. Specifically, the field lacks a conceptual framework that defines and describes the relevant components of a decision, leading to imprecise language and concepts. The ‘judgment and decision-making’ (JDM) framework in human psychology is a powerful tool for framing and understanding human decisions, and we apply it here to components of animal decisions, which we refer to as ‘cognitive phenotypes’. We distinguish multiple cognitive phenotypes in the context of a JDM framework and highlight empirical approaches to characterize them as evolvable traits
Use of Aerial Laser Scanning to Assess the Effect on C Sequestration of Oak (Quercus ilex L. subsp. ballota [Desf.]Samp-Q. suber L.) Afforestation on Agricultural Land
Conversion of agricultural lands to forest plantations to mitigate rising atmospheric carbon dioxide (CO2) has been proposed, but it depends on accurate estimation of the on-site carbon (C) stocks distribution. The use of aerial laser scanning (ALS) data is a rapidly evolving technology for the quantification of C stocks. We evaluated the use of allometric models together with high-density ALS data for the quantification of biomass and soil C stocks in a 14-year-old Quercus ilex and Q. suber plantation in Southwestern Spain. In 2010, a field survey was performed and tree dasometric and biomass variables were measured. Forty-five soil profiles (N = 180 soil samples) were taken systematically and the soil organic C content (SOC) was determined. Biomass and soil organic C values were regressed against individual dasometric variables and total tree height was used as a predictor variable. Aerial laser scanning data were acquired with a point density of 12 points m−2. Relationships among ALS metrics and tree height were determined using stepwise regression models and used in the allometric models to estimate biomass and SOC C stocks. Finally, a C stock map of the holm-cork oak cover in the study area was generated. We found a tree total biomass of 27.9 kg tree−1 for holm oak and 41.1 kg tree−1 for cork oak. In the holm oak plantation, the SOC content was 36.90 Mg ha−1 for the layer 0–40 cm (SOC40) under the tree crown and 29.26 Mg ha−1 for the inter-planted area, with significant differences from the reference agricultural land (33.35 Mg ha−1). Linear regression models were developed to predict the biomass and SOC at the tree scale, based on tree height (R2 >0.72 for biomass, and R2 >0.62 for SOC). The overall on-site C stock in the holm-cork oak plantation was 35.11 Mg ha−1, representing a net C stock rise of 0.47 Mg ha−1 yr−1. The ALS data allows a reliable estimation of C stocks in holm and cork oak plantations and high-resolution maps of on-site C stocks are useful for silvicultural planning. The cost of ALS data acquisition has decreased and this method can be generalised to plantations of other Mediterranean species established on agricultural lands at regional scales. However, an increase of filed data and the availability of local biomass and, in particular, SOC will improve accurate quantification of the C stocks from allometric equations, and extrapolation to large planted areas
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