48 research outputs found
Predicting the effects of climate change on future freshwater fish diversity at global scale
The aim of the present study was to predict future changes in biodiversity attributes (richness, rarity, heterogeneity, evenness, functional diversity and taxonomic diversity) of freshwater fish species in river basins around the world, under different climate scenarios. To do this, we use a new methodological approach implemented within the ModestR software (NOO3D) which allows estimating simple species distribution predictions for future climatic scenarios. Data from 16,825 freshwater fish species were used, representing a total of 1,464,232 occurrence records. WorldClim 1.4 variables representing average climate variables for the 1960-1990 period, together with elevation measurements, were used as predictors in these distribution models, as well as in the selection of the most important variables that account for species distribution changes in two scenarios (Representative Concentration Pathways 4.5 and 6.0). The predictions produced suggest the extinction of almost half of current freshwater fish species in the coming decades, with a pronounced decline in tropical regions and a greater extinction likelihood for species with smaller body size and/or limited geographical ranges
Global diversity patterns of freshwater fishes - Potential victims of their own success
Aim To examine the pattern and cumulative curve of descriptions of freshwater
fishes world-wide, the geographical biases in the available information on that
fauna, the relationship between species richness and geographical rarity of such
fishes, as well as to assess the relative contributions of different environmental
factors on these variables.
Location Global.
Methods MODESTR was used to summarize the geographical distribution of
freshwater fish species using information available from data-based geographical
records. The first-order jackknife richness estimator was used to estimate the
completeness of such data in all terrestrial 1-degree cells world-wide. An
a-shape procedure was used to build range maps capable of providing relatively
accurate species richness and geographical rarity values for each grid cell. We
also examined the explanatory capacity of a high number of environmental
variables using multiple regressions and Support Vector Machine.
Results Cumulative species description curves show that a high number of species
of freshwater fishes remain to be discovered. Completeness values indicate
that only 199 one-degree grid cells, mainly located in eastern North America
and Europe, could be considered as having relatively accurate inventories.
Range maps provide species richness values that are positively and significantly
related to those resulting from the first-order jackknife richness estimator. The
relationship between species richness and geographical rarity is triangular, so
that these species-rich cells are those with a higher proportion of distributionally
rare species. Species richness is predicted by climatic and/or productivity
variables but geographical rarity is not.
Main conclusions In general, species-rich tropical areas harbour a higher
number of narrowly distributed species although comparatively species-poor
subtropical cells may also contain narrowly distributed species. Historical factors
may help to explain the faunistic composition of these latter areas; a supposition
also supported by the low predictive capacity of climatic and
productivity variables on geographical rarity values
Predicting the effects of climate change on future freshwater fish diversity at global scale
The aim of the present study was to predict future changes in biodiversity attributes (richness, rarity, heterogeneity, evenness, functional diversity and taxonomic diversity) of freshwater fish species in river basins around the world, under different climate scenarios. To do this, we use a new methodological approach implemented within the ModestR software (NOO3D) which allows estimating simple species distribution predictions for future climatic scenarios. Data from 16,825 freshwater fish species were used, representing a total of 1,464,232 occurrence records. WorldClim 1.4 variables representing average climate variables for the 1960Âż1990 period, together with elevation measurements, were used as predictors in these distribution models, as well as in the selection of the most important variables that account for species distribution changes in two scenarios (Representative Concentration Pathways 4.5 and 6.0). The predictions produced suggest the extinction of almost half of current freshwater fish species in the coming decades, with a pronounced decline in tropical regions and a greater extinction likelihood for species with smaller body size and/or limited geographical ranges.We acknowledge institutional support from the Unit of Information Resources for Research at the Unit of Information Resources for Research at the "Consejo Superior de Investigaciones CientĂficas" (CSIC) for the article-processing charges contribution
A procedure to assess the spatial variability in the importance of abiotic factors affecting distributions: the case of world freshwater fishes
Understanding the factors shaping species' distributions is a key longstanding topic in ecology with unresolved issues. The aims were to test whether the relative contribution of abiotic factors that set the geographical range of freshwater fish species may vary spatially and/or may depend on the geographical extent that is being considered. The relative contribution of factors, to discriminate between the conditions prevailing in the area where the species is present and those existing in the considered extent, was estimated with the instability index included in the R package SPEDInstabR. We used 3 different extent sizes: 1) each river basin where the species is present (local); 2) all river basins where the species is present (regional); and 3) the whole Earth (global). We used a data set of 16,543 freshwater fish species with a total of 845,764 geographical records, together with bioclimatic and topographic variables. Factors associated with temperature and altitude show the highest relative contribution to explain the distribution of freshwater fishes at the smaller considered extent. Altitude and a mix of factors associated with temperature and precipitation were more important when using the regional extent. Factors associated with precipitation show the highest contribution when using the global extent. There was also spatial variability in the importance of factors, both between species and within species and from region to region. Factors associated with precipitation show a clear latitudinal trend of decreasing in importance toward the equator
Alterations of perineuronal nets in the dorsolateral prefrontal cortex of neuropsychiatric patients
Background: Alterations in the structure and physiology of interneurons in the prefrontal cortex (PFC) are important factors in the etiopathology of different psychiatric disorders. Among the interneuronal subpopulations, parvalbumin (PV) expressing cells appear to be specially affected. Interestingly, during development and adulthood the connectivity of these interneurons is regulated by the presence of perineuronal nets (PNNs), specialized regions of the extracellular matrix, which are frequently surrounding PV expressing neurons. Previous reports have found anomalies in the density of PNNs in the PFC of schizophrenic patients. However, although some studies have described alterations in PNNs in some extracortical regions of bipolar disorder patients, there are no studies focusing on the prefrontocortical PNNs of bipolar or major depression patients. For this reason, we have analyzed the density of PNNs in post-mortem sections of the dorsolateral PFC (DLPFC) from the Stanley Neuropathology Consortium, which includes controls, schizophrenia, bipolar and major depression patients. Results: We have not observed differences in the distribution of PV+ cells or PNNs, or in the percentage of PV+ interneurons surrounded by PNNs. The density of PV+ interneurons was similar in all the experimental groups, but there was a significantly lower density of PNNs in the DLPFC of bipolar disorder patients and a tendency towards a decrease in schizophrenic patients. No differences were found when evaluating the density of PV+ cells surrounded by PNNs. Interestingly, when assessing the influence of demographic data, we found an inverse correlation between the density of PNNs and the presence of psychosis. Conclusions: The present results point to prefrontocortical PNNs and their role in the regulation of neuronal plasticity as putative players in the etiopathology of bipolar disorder and schizophrenia. Our findings also suggest a link between these specialized regions of the extracellular matrix and the presence of psychosis
Modestr : a software tool for studying of colombian aquatic ecosystems
ABSTRACT: The aim of this manuscript is to show the usefulness of the software package ModestR in studies of distribution of Colombian marine and freshwater species. This software is free available at the Website: . To show and test the potential of ModestR, here an exemplar assessment is presented of a database using all valid species of freshwater shes of the orders Characiformes and Siluriformes, and their geographical records available in the Global Biodiversity Information Facility (GBIF, 2012), and of the order Carcharhiniformes as representatives of marine species. ModestR includes, in its initial phase, two applications: DataManager and MapMaker. The application DataManager is designed for an integrated taxonomic information and maps of the distribution of any species group. The application MapMaker has been designed to generate species distribution maps in four different ways: 1) by importing a CSV le with the name of the species and their geographical coordinates, 2) importing the geographical records automatically from GBIF, 3) importing geographical coordinates generated by distribution models, and 4) making expert maps by selecting distribution areas, according to the types of habitats occupied by the species. The possibility of working with habitats is one of the most important contributions of ModestR and, in particular, that are mapped small lotic ecosystems (creeks, streams, etc.), large lotic ecosystems (rivers) and lentic ecosystems (ponds, lakes, reservoirs, swamps, etc.). Moreover, it is also possible to select marine and terrestrial ecosystems. Therefore, although the manuscript has been focused on species of aquatic ecosystems, ModestR also allows the same type of studies with terrestrial species.RESUMEN: El objetivo de este trabajo es mostrar las utilidades del programa informaÌtico ModestR, en estudios sobre distribucioÌn de especies en ecosistemas marinos y de agua dulce de Colombia. Este programa se encuentra disponible en la Web de manera gratuita: . Para ensenÌar y probar el funcionamiento de ModestR se trabajoÌ con los datos disponibles en el Global Biodiversity Information Facility (GBIF, 2012) de los oÌrdenes Characiformes y Siluriformes, como ejemplo de especies de peces dulciacuiÌcolas, y del orden Carcharhiniformes de especies marinas. ModestR incluye en su fase inicial, dos aplicaciones: DataManager y MapMaker. La aplicacioÌn DataManager estaÌ disenÌada para realizar manejo integrado de informacioÌn taxonoÌmica y mapas de distribucioÌn de cualquier grupo de especies. La aplicacioÌn MapMaker permite generar mapas de distribucioÌn de especies de cuatro formas diferentes: 1) importando un archivo CSV con el nombre de las especies y las coordenadas geograÌ cas, 2) importando los datos automaÌticamente del GBIF, 3) importando las coordenadas geograÌ cas generadas de modelos de distribucioÌn y 4) realizando mapas expertos, lo cual consiste en seleccionar las aÌreas de distribucioÌn, de acuerdo a los tipos de haÌbitats en que ocurre la o las especies en estudio. La posibilidad de trabajar con haÌbitats es una de las contribuciones maÌs importantes de ModestR y, en particular, la de que los haÌbitats loÌticos pequenÌos (quebradas, arroyos, etc.), los loÌticos grandes (riÌos) y los lenticos (lagunas, lagos, embalses, cieÌnagas, etc.) estaÌn cartogra ados con muy alta resolucioÌn. AdemaÌs, tambieÌn se diferencian los ecosistemas marino y terrestre. A pesar de que este estudio se enfocoÌ en especies de ecosistemas acuaÌticos, ModestR permite tambieÌn realizar el mismo tipo de ejercicios con especies terrestres
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Dietary αâLinolenic Acid, Marine Ïâ3 Fatty Acids, and Mortality in a Population With High Fish Consumption: Findings From the PREvenciĂłn con DIeta MEDiterrĂĄnea (PREDIMED) Study
Background: Epidemiological evidence suggests a cardioprotective role of αâlinolenic acid (ALA), a plantâderived Ïâ3 fatty acid. It is unclear whether ALA is beneficial in a background of high marine Ïâ3 fatty acids (longâchain nâ3 polyunsaturated fatty acids) intake. In persons at high cardiovascular risk from Spain, a country in which fish consumption is customarily high, we investigated whether meeting the International Society for the Study of Fatty Acids and Lipids recommendation for dietary ALA (0.7% of total energy) at baseline was related to allâcause and cardiovascular disease mortality. We also examined the effect of meeting the society's recommendation for longâchain nâ3 polyunsaturated fatty acids (â„500 mg/day). Methods and Results: We longitudinally evaluated 7202 participants in the PREvenciĂłn con DIeta MEDiterrĂĄnea (PREDIMED) trial. Multivariableâadjusted Cox regression models were fitted to estimate hazard ratios. ALA intake correlated to walnut consumption (r=0.94). During a 5.9ây followâup, 431 deaths occurred (104 cardiovascular disease, 55 coronary heart disease, 32 sudden cardiac death, 25 stroke). The hazard ratios for meeting ALA recommendation (n=1615, 22.4%) were 0.72 (95% CI 0.56â0.92) for allâcause mortality and 0.95 (95% CI 0.58â1.57) for fatal cardiovascular disease. The hazard ratios for meeting the recommendation for longâchain nâ3 polyunsaturated fatty acids (n=5452, 75.7%) were 0.84 (95% CI 0.67â1.05) for allâcause mortality, 0.61 (95% CI 0.39â0.96) for fatal cardiovascular disease, 0.54 (95% CI 0.29â0.99) for fatal coronary heart disease, and 0.49 (95% CI 0.22â1.01) for sudden cardiac death. The highest reduction in allâcause mortality occurred in participants meeting both recommendations (hazard ratio 0.63 [95% CI 0.45â0.87]). Conclusions: In participants without prior cardiovascular disease and high fish consumption, dietary ALA, supplied mainly by walnuts and olive oil, relates inversely to allâcause mortality, whereas protection from cardiac mortality is limited to fishâderived longâchain nâ3 polyunsaturated fatty acids. Clinical Trial Registration URL: http://www.Controlled-trials.com/. Unique identifier: ISRCTN35739639
Can we derive macroecological patterns from primary Global Biodiversity Information Facility data?
Emilio GarcĂa-RosellĂł [et al.]Aim
To determine whether the method used to build distributional maps from raw data influences the representation of two principal macroecological patterns: the latitudinal gradient in species richness and the latitudinal variation in range sizes (Rapoportâs rule).Location
World-wide.Methods
All available distribution data from the Global Biodiversity Information Facility (GBIF) for those fish species that are members of orders of fishes with only marine representatives in each order were extracted and cleaned so as to compare four different procedures: point-to-grid (GBIF maps), range maps applying an α
-shape [GBIF-extent of occurrence (EOO) maps], the MaxEnt method of species distribution modelling (GBIF-MaxEnt maps) and the MaxEnt method but restricted to the area delimited by the α-shape (GBIF-MaxEnt-restricted maps).Results
The location of hotspots and the latitudinal gradient in species richness or range sizes are relatively similar in the four procedures. GBIF-EOO maps and most GBIF-MaxEnt-maps provide overestimations of species richness when compared with those present in a priori well-surveyed cells. GBIF-EOO maps seem to provide more reasonable world macroecological patterns. MaxEnt can erroneously predict the presence of species in environmentally similar cells of another hemisphere or in other regions that lie outside the range of the species. Limiting this overpredictive capacity, as in the case of GBIF-MaxEnt-restricted maps, seems to mimic the frequency of observations derived from a simple point-to-grid procedure, with the utility of this procedure consequently being limited.Main conclusions
In studies of macroecological patterns at a global scale, the simple α-shape method seems to be a more parsimonious option for extrapolating species distributions from primary data than are distribution models performed indiscriminately and automatically with MaxEnt. GBIF data may be used in macroecological patterns if original data are cleaned, autocorrelation is corrected and species richness figures do not constitute obvious underestimations. Efforts therefore should focus on improving the number and quality of records that can serve as the source of primary data in macroecological studies.Peer reviewe