Distance decay 2.0 – A global synthesis of taxonomic and functional turnover in ecological communities

Trabajo elaborado por más de cincuenta autores.Aim: Understanding the variation in community composition and species abundances (i.e., β-diversity) is at the heart of community ecology. A common approach to examine β-diversity is to evaluate directional variation in community composition by measuring the decay in the similarity among pairs of communities along spatial or nvironmental distance. We provide the first global synthesis of taxonomic and functional distance decay along spatial and environmental distance by analysing 148 datasets comprising different types of organisms and environments. Location: Global.Time period: 1990 to present. Major taxa studied: From diatoms to mammals. Method: We measured the strength of the decay using ranked Mantel tests (Mantel r) and the rate of distance decay as the slope of an exponential fit using generalized linear models. We used null models to test whether functional similarity decays faster or slower than expected given the taxonomic decay along the spatial and environmental distance. We also unveiled the factors driving the rate of decay across the datasets, including latitude, spatial extent, realm and organismal features. Results: Taxonomic distance decay was stronger than functional distance decay along both spatial and environmental distance. Functional distance decay was random given the taxonomic distance decay. The rate of taxonomic and functional spatial distance decay was fastest in the datasets from mid-latitudes. Overall, datasets covering larger spatial extents showed a lower rate of decay along spatial distance but a higher rate of decay along environmental distance. Marine ecosystems had the slowest rate of decay along environmental distances. Main conclusions: In general, taxonomic distance decay is a useful tool for biogeographical research because it reflects dispersal-related factors in addition to species responses to climatic and environmental variables. Moreover, functional distance decay might be a cost-effective option for investigating community changes in heterogeneous environments

PTL: A Model Transformation Language based on Logic Programming

In this paper we present a model transformation language based on logic programming. The language, called PTL (Prolog based Transformation Language), can be considered as a hybrid language in which ATL (Atlas Transformation Language)-style rules are combined with logic rules for defining transformations. ATL-style rules are used to define mappings from source models to target models while logic rules are used as helpers. The implementation of PTL is based on the encoding of the ATL-style rules by Prolog rules. Thus, PTL makes use of Prolog as a transformation engine. We have provided a declarative semantics to PTL and proved the semantics equivalent to the encoded program. We have studied an encoding of OCL (Object Constraint Language) with Prolog goals in order to map ATL to PTL. Thus a subset of PTL can be considered equivalent to a subset of ATL. The proposed language can be also used for model validation, that is, for checking constraints on models and transformations. We have equipped our language with debugging and tracing capabilities which help developers to detect programming errors in PTL rules. Additionally, we have developed an Eclipse plugin for editing PTL programs, as well as for debugging, tracing and validation. Finally, we have evaluated the language with several transformation examples as well as tested the performance with large models

Social preferences in achieving sustainable development goals: an empirical study of the water resources case

This paper focuses on the roots of the responsible behavior, more precisely, about the relationship between social welfare preferences and responsible behavior. This r elationship is complex and interconnected, reflecting the intricate interplay between personal values, societal norms, and ethical considerations

Run-over of mammals in Uruguay’s Eastern Region and its relationship with landscape attributes

Las carreteras constituyen una amenaza para la biodiversidad y causan impactos negativos como fragmentación de hábitats y atropellos. En el año 2015, la ONG ECOBIO Uruguay comenzó a trabajar en la temática con el fin de implementar medidas de mitigación. El objetivo de este trabajo fue describir y analizar los atropellos de medianos y grandes mamíferos en la Región Este de Uruguay y su relación con los atributos del paisaje. Partiendo de que la dinámica de los atropellos está influenciada en su mayoría por factores antrópicos, el tránsito es la variable explicativa más significativa. Se utilizaron algoritmos de aprendizaje automático (Random Forest) para modelar los atropellos de la región, caracterizada por la alta heterogeneidad de ecosistemas, la importante biodiversidad y varias áreas protegidas. Se analizaron 976 casos de atropellos, de 17 especies, que se distribuyeron de manera heterogénea. Los modelos para todas las especies presentaron una capacidad predictiva de más del 60% de acierto, y de un 80% para los modelos por especie. La ruta con mayor probabilidad de atropello fue la 9. Si bien las variables más importantes fueron similares en todos los modelos, las tres que los explicaron mejor fueron: el tránsito promedio diario anual, la distancia a caminos y la distancia a centros urbanos. Este trabajo es de los primeros estudios a nivel nacional que cuantifican formalmente el fenómeno, y sugiere que lo conveniente es analizar las especies por separado para evaluar posibles respuestas diferenciales que imposibiliten hallar patrones generalesRoads constitute a threat to biodiversity, causing negative impacts such as fragmentation of habitats and run overs. In 2015, the NGO ECOBIO Uruguay began working on the subject in order to implement mitigation measures. The purpose of this research is to analyze medium and large-sized mammals’ run over in Uruguay’s Eastern region and its relationship with landscape attributes. Taking off the dynamic of run overs, this is frequently influenced by anthropic cases, traffic is the most prominent variable over this. Machine learning algorithms (Random Forest) and QGIS and R programs were used to model the run overs of the region, that is characterized by having heterogeneous ecosystems, important biodiversity and several protected areas. 976 cases of run overs were analyzed, from 17 species, that were distributed heterogeneously. The models analyzed by species had a predictive ability of 80% success, while when working with all species as a whole 60%. The route with the highest probability run overs was ‘Route 9’. Although the most important variables were similar in all the models, the three that better illustrated the prediction models were: annual average daily traffic, the distance to backroads and distance to populated roads, this three illustrates better the predictions models. This work is one of the first studies at a national level which formally quantifies the phenomenon and suggests analyzing the species separately to evaluate possible differential responses that make it impossible to find general patterns

Bandgap widening in macroporous silicon photonic crystals by multiperiodic structures

Large bandgaps with low transmission in 3D macroporous silicon photonic crystals have been proved as an interesting technology for the development of optical filters and spectroscopic MIR gas sensors. The aim of this study is the investigation of different bandgap widening methods based on multiperiodic structures for 3D macroporous silicon photonic crystals. To do so, chirped modulations and structures with different periodicity groups have been modelled and theoretically analysed by means of 3D FDTD simulations. They have revealed that by using different decreasing periodicity groups, bandgaps with null transmission and widths as high as 1800 nm, 4 times the original single periodicity photonic crystal bandgap, can be obtained. Furthermore, it has been shown that a resonant cavity with a 20% transmission can be placed in a 1 µm wide bandgap. The results open a way to use this type of structures not only for gas sensing but also for other purposes such as wide stop-band filters, selective filters or broadband mirrors.Peer ReviewedPostprint (published version

Incremental SVM of controlled full-bridge rectifiers to allow IEC 61000-3-2 enforcement in power grid connection of modern elevator systems

The purpose of this paper is the study of different power converters and control techniques to allow power grid connection of modern vertical operation systems, verifying IEC 61000-3-2. We focus on the harmonic current analysis produced by the industrial standard AC/DC/3-phase AC machines system. Different AC/DC converters and control techniques have been compared to determine the one that minimizes low frequency harmonic current production. An incremental space vector modulator to regulate power grid current flow in electrical reference frame with a full-bridge controlled rectifier has been proven as the best power grid connection system. A general purpose test rig has been designed to evaluate the different power grid interface policies. Experimental results have been provided to show the effectiveness of the method

Effects of Moringa oleifera and Brosimum alicastrum partial feed substitution in intramuscular fat and adipose tissues and on the expression of lipogenic genes of Mexican hairless pigs

The present study evaluated the effects of the inclusion of ground Moringa oleifera and Brosimum alicastrum leaf meal in the diet of Mexican hairless pigs (MHP) on the amount of intramuscular fat, subcutaneous fat, leg muscle (Biceps femoris) fat, loin muscle (Longissimus dorsi) fat, leg and back fat, and the expression of lipid metabolism genes. Hairless pigs are reared in the Mexican tropics and are characterised by their body and intramuscular fat accumulation. Eighteen male pigs fed for 82 d were randomly allotted to three experimental isoenergetic and isoproteic diets, where M. oleifera or B. alicastrum (six pigs per diet) replaced wheat bran. The diets used were a control diet, a diet with 10% M. oleifera leaf meal, and a diet with 10% ground B. alicastrum leaf meal. The M. oleifera diet decreased (P<0.05) the fat ratio in the Longissimus dorsi muscles, back fat, rib fat, total carcass fat, and the carcass fat: meat ratio. The B. alicastrum diet only decreased fat in the Biceps femoris muscle, back fat, and rib fat. Moringa oleifera and B. alicastrum diets also promoted the overexpression of mRNA from the stearoyl-CoA desaturase (SCD), fatty acid synthase (FASN), acetyl-CoA carboxylase alpha (ACACA), sterol regulatory element-binding protein 1 (SREBP1) and acyl carrier protein (ACP) lipogenic genes in the Biceps femoris muscle and leg fat (P<0.001). In addition, lower ACACA and SREBP1 mRNA expression in the Longissimus dorsi muscle and back fat (P<0.001) were related to the lower amount of fat in pigs fed M. oleifera and B. alicastrum. The inclusion of Moringa oleifera and Brosimum alicastrum meals 10% in the diet of the pig MHP reduces fat, this is an important finding because fat is abundant in this type of pig

Ratones knock-out del receptor lpa1 de ácido lisofosfatídico presentan un acusado déficit de la isoenzima glutaminasa KGA (GLS) y una morfología alterada en las espinas dendríticas de hipocampo y corteza

Objectives: The objective of the present study was to utilize mice with knocked-down lysophosphatidic acid 1 (LPA1) receptor to ascertain changes in glutamatergic transmission that may help to explain part of the cognitive and memory deficits shown by these KO-LPA1 mice. Material & methods: A well characterized KO-LPA1 mouse strain was used as animal model and compared with wild-type (WT) and heterozygous animals. Expression studies were implemented by immunohistochemistry and Western analysis of mouse brain regions, real-time quantitative RT-PCR of GA isoforms, enzymatic analysis of regional GA activity and Golgi staining to assess dendritic spine morphology and density. Results: A strong reduction of KGA immunoreactivity was mostly revealed in cerebral cortex and hippocampus of KO-LPA1 mice versus WT and heterozygous animals. In contrast, neither mRNA levels nor enzyme activity were significantly altered in KO mice suggesting compensatory mechanisms for neurotransmitter Glu synthesis. Interestingly, Golgi staining of hippocampal and cortical neurons revealed a clear morphology change toward a less-mature undifferentiated spine phenotype, without changes in the total number of spines. Conclusions: The molecular mechanisms underlying KGA downregulation in null LPA1 mutant mice are unknown. However, LPA increases neuronal differentiation, arborization and neurite outgrowth of developing neurons, while Gln-derived Glu, through GA reaction, has been also involved in neuronal growth and differentiation. It is tempting to speculate that downregulation of KGA protein in KO-LPA1 mice induce morphological changes in dendritic spines of cortical and hippocampal neurons which, in turn, may account for memory and cognitive deficits shown by KO-LPA1 mice.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Acknowledgements: Red de Trastornos Adictivos, RTA, (RD12/0028/0013/) RETICS, ISCIII, y Consejería Innovación, Ciencia y Empresa, Junta de Andalucía (Proyecto de Excelencia CVI-6656)

Oceanografía biológica de Cabo Polonio: apuntes sobre investigaciones recientes

Los resultados presentados en esta publicación se enmarcan dentro del proyecto financiado por ANII, código: ANII_FCE_2017_136372.Oceanografía biológica de Cabo Polonio: apuntes sobre investigaciones recientes ofrece una muy rápida recorrida por los orígenes de la oceanografía como área del conocimiento científico y las actividades que investigadores de la Facultad de Ciencias y del Centro Universitario Regional Este, ambos de la Universidad de la República, desarrollan en la zona marina costera de Cabo Polonio. Cabo Polonio es interesante desde diversos puntos de vista: histórico, arqueológico, sociológico, paisajístico, ecológico. Durante el siglo XX fue epicentro de la explotación de la mayor población de lobos marinos del Atlántico Sur. Rastros de ese pasado se conservan en la infraestructura de la Base que alojaba a los trabajadores: comedor-cocina, galpones y dormitorios, caldera industrial y un gran bote a remo; implementos para la faena: garrotes, cuchillas, estaqueaderos de cueros... Aún es posible encontrar en ciertos boliches o almacenes del Cabo a veteranos de aquellas lides y - con un poco de suerte - aprender sus historias. El valor paisajístico de Cabo Polonio ha impulsado el crecimiento del centro poblado gracias al influjo del turismo estival y de no pocos que llegaron de visita y decidieron quedarse. Esto plantea enormes desafíos para la conservación de un sitio que no dispone de facilidades como agua potable y saneamiento, electricidad, caminería y cuya biodiversidad - uno de sus grandes atractivos - es muy sensible a cambios en el paisaje. La biodiversidad es uno de los elementos que llevó a incluir a Cabo Polonio en el Sistema Nacional de Areas Protegidas. Sin embargo, el conocimiento de la fauna y flora marinas, así como de los procesos bio-físicos que sustentan esa biodiversidad son muy poco conocidos. El trabajo que aquí se presenta busca contribuir a dicho conocimiento e - indirectamente- al buen uso y manejo del sitio