257 research outputs found

    The biomechanical importance of the scaphoid-centrale fusion during simulated knuckle-walking and its implications for human locomotor evolution

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    © 2020, The Author(s). Inferring the locomotor behaviour of the last common ancestor (LCA) of humans and African apes is still a divisive issue. An African great-ape-like ancestor using knuckle-walking is still the most parsimonious hypothesis for the LCA, despite diverse conflicting lines of evidence. Crucial to this hypothesis is the role of the centrale in the hominoid wrist, since the fusion of this bone with the scaphoid is among the clearest morphological synapomorphies of African apes and hominins. However, the exact functional significance of this fusion remains unclear. We address this question by carrying out finite element simulations of the hominoid wrist during knuckle-walking by virtually generating fused and unfused morphologies in a sample of hominoids. Finite element analysis was applied to test the hypothesis that a fused scaphoid-centrale better withstands the loads derived from knuckle-walking. The results show that fused morphologies display lower stress values, hence supporting a biomechanical explanation for the fusion as a functional adaptation for knuckle-walking. This functional interpretation for the fusion contrasts with the current inferred positional behaviour of the earliest hominins, thus suggesting that this morphology was probably retained from an LCA that exhibited knuckle-walking as part of its locomotor repertoire and that was probably later exapted for other functions

    Knee function through finite element analysis and the role of Miocene hominoids in our understanding of the origin of antipronograde behaviours: the Pierolapithecus catalaunicus patella as a case study

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    Although extensive research has been carried out in recent years on the origin and evolution of human bipedalism, a full understanding of this question is far from settled. Miocene hominoids are key to a better understanding of the locomotor types observed in living apes and humans. Pierolapithecus catalaunicus, an extinct stem great ape from the middle Miocene (c. 12.0 Ma) of the Vallès-Penedès Basin (north-eastern Iberian Peninsula), is the first undoubted hominoid with an orthograde (erect) body plan. Its locomotor repertoire included above-branch quadrupedalism and other antipronograde behaviours. Elucidating the adaptive features present in the Pierolapithecus skeleton and its associated biomechanics helps us to better understand the origin of hominoid orthogrady. This work represents a new biomechanical perspective on Pierolapithecus locomotion, by studying its patella and comparing it with those drawn from a large sample of extant anthropoids. This is the first time that the biomechanical patellar performance in living non-human anthropoids and a stem hominid has been studied using finite element analysis (FEA). Differences in stress distribution are found depending on body plan and the presence/absence of a distal apex, probably due to dissimilar biomechanical performances. Pierolapithecus’ biomechanical response mainly resembles that of great apes, suggesting a similar knee joint use in mechanical terms. These results underpin previous studies on Pierolapithecus, favouring the idea that a relevant degree of some antipronograde behaviour may have made up part of its locomotor repertoire. Moreover, our results corroborate the presence of modern great ape-like knee biomechanical performances back in the Miocene

    Effect of N dose, fertilisation duration and application of a nitrification inhibitor on GHG emissions from a peach orchard

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    Despite only occupying 5% of the worldwide arable area, fruit tree crops are of vital economic importance in many regions. Intensive cropping practices can lead to greenhouse gas (GHG) emissions. In order to reduce these emissions, numerous studies have been made on lowering N inputs or applying nitrification inhibitors (NIs) which tend to maintain or even increase yield while reducing N leaching and nitrogenous emissions to the atmosphere. However, very few studies have been conducted on potential GHG emissions from the peach crop. In this work, a three-year study was carried out in a commercial peach orchard with a split-plot design with three replicates, in which the main factor was N dose (25, 50 and 100 kg N ha−1 year−1, and 50 kg N ha−1 year−1 applied during a shorter period of time in 2015 and 2016; and only 70 kg N ha−1 year−1 in 2017). Subplots in the study were used to analyse the effect of the application of a NI (3,4-dimethylpyrazole phosphate; DMPP). The aim was to qualitatively compare the effect of these factors on N2O, N2O + N2, CH4 and CO2 emissions from a peach orchard soil in order to recommend agricultural practices that minimise emissions without concurrent yield reductions. We show that N2O and N2O + N2 emissions were linked to fertilisation and increased with N dose. The N2O emissions were mitigated (up to 49%) by DMPP up to the 50 kg N ha−1 dose (not significantly). It seems that between 70 and 100 kg N ha−1 the application of DMPP loses effectiveness. Methane oxidation increased with N dose and decreased with DMPP application; CO2 emissions increased with DMPP and were unaffected by N dose. The intermediate N dose (50 kg N ha−1) applied during a shorter period of time increased yield (not significantly) and NUE without increasing GHG emissions.info:eu-repo/semantics/acceptedVersio

    Características y funciones para marcas de lugar a partir de un método Delphi

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    [ES] Introducción. La representación de territorios mediante el uso de marcas es una cuestión recurrente en la sociedad contemporánea que vivimos. Este artículo tiene por objetivo principal determinar algunas de las características y funciones que presentan las marcas asociadas a espacios geográficos. Metodología. Se ha optado por una investigación cualitativa vehiculada a partir de un método Delphi conformado por un panel de catorce expertos en marcas de lugar. Resultados. En relación con las marcas comerciales, se constata que las marcas de lugar, por su naturaleza de bien público, requieren de una gestión más compleja, preferentemente a tres niveles: administración pública, organizaciones privadas y ciudadanía. Conclusiones. En función de los resultados obtenidos, se concluye que la gestión de los lugares se encuentra nuevamente ocupada en la proyección de identidades espaciales singulares, en el marco de una creciente competencia entre territorios.Introduction. Representation of territories through brands is a recurring issue in today’s modern society. The aim of this article is to establish certain characteristics and functions pertaining to brands linked to geographical areas. Methodology. The decision was made to conduct qualitative research based on a Delphi method comprising a panel of fourteen place branding experts. Results. In relation to commercial brands, it is found that, since they are publicly owned, place brands call for more complex management, preferably on three levels: public administration, private organisations and citizens. Conclusions. Based on the results obtained, it is concluded that management of places centres on the projection of unique, spatial identities on the context of increasing competition between territories

    Lifeguard assistance at Spanish Mediterranean beaches: Jellyfish prevail and proposals for improving risk management

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    Although beaches can be hazardous environments, few studies have identified injuries in broad coastal areas. We performed a retrospective descriptive study of injuries and other services provided by lifeguards during 2012 along the Spanish Mediterranean beaches. The trend in jellyfish stings was also examined for the period 2008–2012 using a standardised Sting Index. Obtaining data relied on voluntary cooperation of local authorities, resulting in data provided from 183 cities out of 234 present in the study area and 760 beach lifeguard stations (LGS) out of about 1200. Lifeguard stations provided an average of 89 days of service per year, from late June to the beginning of September. A total of 176,021 injuries were reported, of which jellyfish stings were the main need for assistance with 59.7% (n = 116,887) of the injuries and 257.0/LGS, followed by wounds (14.4%, 50.9/LGS), and sunburn (3.3%, 15.8/LGS). Apart from attending injuries, beach lifeguard services provided 21,174 other services such as help to disabled people (57.9/LGS), blood pressure measurements (12.7/LGS), rescues at sea (6.5/LGS), lost children (5.7/LGS), and transfers to the hospital (4.6/LGS). Official reported fatalities for all the beaches in 2012 were 24. We proposed a Sting Index (SI) to allow comparisons of the incidence of stings between years and/or localities by standardising jellyfish stings by the total of all injuries. Historical data were consistent enough to calculate SI between 2010 and 2012 and showed an oscillating pattern without a clear trend (2008: 2.4, 2009: 1.3, 2010: 2.4, 2011: 2.0, 2012: 2.6). Estimation of total number of jellyfish stings for all the beaches present in the area would reach 184,558 for 2012. There were very few fatalities in comparison with other coastal regions, probably due to the combination of a calm sea, a low number of high dangerous situations, and a high percentage of lifeguarded beaches during the bathing season. Nevertheless, although Spanish Mediterranean beaches could be described as low risk, we propose measures to facilitate a precautionary management to prevent injuries based on a real-time beach assistance database of injuries to identify high-incidence assistance categories.This research was carried out under contract LIFE 08 NAT ES 0064 (to CB and VF) co-financed by the European Commission (www.cubomed.eu), the Ministerio de Agricultura, Alimentación y Medio Ambiente (Dirección General de Sostenibilidad de la Costa y el Mar) contract 2013/28-5158, the Dirección General del Agua of the Regional Government of Valencia (grant T7588000/512.10) and the Fundación Biodiversidad (grant LIFE Cubomed 2013/2014)

    Geographies of affect: In search of the emotional dimension of place branding

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    Emotion is becoming one of the most important assets for the development of a strategy of place branding, with the primary aim of projecting competitive spatial identities through the use of brands. Despite this, few studies have focused on defining the role played by emotion in the affective connection that is established between people and places in the context of a place branding initiative. Consequently, the main goal of this article is to define a possible emotional dimension of place branding, by performing a meta-analysis and employing the contributions of emotional geography, environmental psychology and non-representational theory

    A new system for fast and quantitative analysis of heterologous gene expression in plants

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    Large-scale analysis of transcription factor–cis-acting element interactions in plants, or the dissection of complex transcriptional regulatory mechanisms, requires rapid, robust and reliable systems for the quantification of gene expression.Here, we describe a new system for transient expression analysis of transcription factors, which takes advantage of the fast and easy production and transfection of Physcomitrella patens protoplasts, coupled to flow cytometry quantification of a fluorescent protein (green fluorescent protein). Two small-sized and high-copy Gateway® vectors were specifically designed, although standard binary vectors can also be employed. As a proof of concept, the regulation of BANYULS (BAN), a key structural gene involved in proanthocyanidin biosynthesis in Arabidopsis thaliana seeds, was used. In P. patens, BAN expression is activated by a complex composed of three proteins (TT2/AtMYB123, TT8/bHLH042 and TTG1), and is inhibited by MYBL2, a transcriptional repressor, as in Arabidopsis. Using this approach, two new regulatory sequences that are necessary and sufficient for specific BAN expression in proanthocyanidin-accumulating cells were identified. This one hybrid-like plant system was successfully employed to quantitatively assess the transcriptional activity of four regulatory proteins, and to identify their target recognition sites on the BAN promoter

    Multibody dynamics analysis (MDA) as a numerical modelling tool to reconstruct the function and palaeobiology of extinct organisms

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    Recent advances in computer technology have substantially changed the field of palaeontology in the last two decades. Palaeontologists now have a whole new arsenal of powerful digital techniques available to study fossil organisms in unprecedented detail and to test hypotheses regarding function and behaviour. Multibody dynamics analysis (MDA) is one of these techniques and although it originated as a tool used in the engineering and automotive industry, it holds great potential to address palaeontological questions as well. MDA allows the simulation of dynamic movements in complex objects consisting of multiple linked components. As such, this technique is ideally suited to model biological structures and to obtain quantifiable results that can be used to test the function of musculoskeletal systems rigorously. However, despite these advantages, MDA has seen a slow uptake by the palaeontological community. The most likely reason for this lies in the steep learning curve and complexity of the method. This paper provides an overview of the underlying principles of MDA and outlines the main steps involved in conducting analyses. A number of recent studies using MDA to reconstruct the palaeobiology of fossil organisms are presented and the potential for future studies is discussed. Similar to other computational techniques, including finite element analysis and computational fluid dynamics, the non‐invasive and exploratory power of MDA makes it ideally suited to study the form and function in vertebrates for which no modern analogues exist

    MRE11 and RAD50, but not NBS1, are essential for gene targeting in the moss Physcomitrella patens

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    The moss Physcomitrella patens is unique among plant models for the high frequency with which targeted transgene insertion occurs via homologous recombination. Transgene integration is believed to utilize existing machinery for the detection and repair of DNA double-strand breaks (DSBs). We undertook targeted knockout of the Physcomitrella genes encoding components of the principal sensor of DNA DSBs, the MRN complex. Loss of function of PpMRE11 or PpRAD50 strongly and specifically inhibited gene targeting, whilst rates of untargeted transgene integration were relatively unaffected. In contrast, disruption of the PpNBS1 gene retained the wild-type capacity to integrate transforming DNA efficiently at homologous loci. Analysis of the kinetics of DNA-DSB repair in wild-type and mutant plants by single-nucleus agarose gel electrophoresis revealed that bleomycin-induced fragmentation of genomic DNA was repaired at approximately equal rates in each genotype, although both the Ppmre11 and Pprad50 mutants exhibited severely restricted growth and development and enhanced sensitivity to UV-B and bleomycin-induced DNA damage, compared with wild-type and Ppnbs1 plants. This implies that while extensive DNA repair can occur in the absence of a functional MRN complex; this is unsupervised in nature and results in the accumulation of deleterious mutations incompatible with normal growth and developmen
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