432 research outputs found
Small ponds support high terrestrial bird species richness in a Mediterranean semiarid region
©2021. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/
This document is the Accepted version of a Published Work that appeared in final form in Hydrobiologia. To access the final edited and published work see https://doi.org/10.1007/s10750-021-04552-7Ponds are among the world’s most endan gered freshwater ecosystems. A comprehensive
knowledge of pond biodiversity is urgently required
to inform effective pond management and conserva tion actions. Most studies about pond biodiversity
focus on aquatic taxa, while the terrestrial biodiver sity, especially of birds, has been little studied.
Moreover, the few studies existing on pond biodiver sity do not account for different detection rates of
species, thus yielding biased results. Here, we apply a
hierarchical Bayesian modelling technique to data
obtained from visual censuses to estimate bird species
richness associated with small ponds in a semiarid
region, considering the imperfect detection of species.
The model incorporates specific responses to site
characteristics (pond typology), landscape (environ mental heterogeneity) and at regional scale (mean
annual precipitation). The studied ponds were used by
two thirds of the terrestrial breeding bird community
of the study region. Our modelling approach increased
by an average of 7.5 species the observed site-specific
richness. Drinking troughs supported a greater rich ness than other pond types. Environmental hetero geneity was positively related with species richness,
whereas no clear relation was observed between
richness and precipitation. In addition to ecosystem
services provided by ponds to human welfare, our
results suggest these small isolated habitats may act as
key landscape elements for terrestrial birds in semiarid
regions
Hamiltonian Noether theorem for gauge systems and two time physics
The Noether theorem for Hamiltonian constrained systems is revisited. In
particular, our review presents a novel method to show that the gauge
transformations are generated by the conserved quantities associated with the
first class constraints. We apply our results to the relativistic point
particle, to the Friedberg et al. model and, with special emphasis, to two time
physics.Comment: 20 pages, Latex, references added, the "massless" sense of (87) is
clarifie
¿Se asocia el consumo de refrescos azucarados con la composición corporal? Estudio transversal en adolescentes españoles
Objectives: Published data about the association between
the consumption of sweetened soft-drinks (SSD)
and obesity in childhood are controversial and still inconsistent.
In addition, data are lacking in the Spanish population.
The purpose of this study was therefore, to explore
the cross-sectional association between body composition-
related parameters and SSD consumption in Spanish
adolescents.
Subjects and methods: A representative sample of 1,523
adolescents (768 boys and 755 girls), with complete dietary
data as well as anthropometric measurements, were
included in this study. Weight, height, waist circumferences,
and 6 skinfolds were measured, and BMI and percentage
body fat were calculated. From a 24h dietary recall
the subjects were grouped in 3 groups according to their
SSD consumption: 1) Non-consumers (0 g of SSD consumption);
2) Moderate consumption (< 336 g/day of
SSD, equivalent to the average SSD portion size); and 3)
High consumption (> 336 g/day of SSD).
Results: 67% males and 75% females did not consume
any SSD the day before the dietary recall interview.
Males consumed more SSD than females. Regarding the
association between SSD consumption and measures of
obesity, no difference was observed between the three
groups of SSD consumption in any of the anthropometric
measurement, BMI or body fat.
Conclusion: As no association was present between
SSD consumption and obesity in our cross-sectional study
we suggest that dietary patterns and habits as well as
lifestyle factors such as physical activity should be present when examining cross-sectional or longitudinal relationships
with obesity. Multidisciplinary intervention
studies are crucial when trying to develop solutions
against the increasing obesity epidemic.Objetivos: Los datos publicados sobre la asociación
entre el consumo de refrescos azucarados (SSD) y la obesidad
en la infancia son controvertidos y todavía inconsistentes.
Además, estos datos son muy escasos en la población
española. Por ello, el propósito de este estudio ha sido
estudiar la asociación entre los parámetros relacionados
con la composición corporal y el consumo de SSD en adolescentes
españoles.
Sujetos y métodos: Se ha realizado el estudio en una
muestra de 1.523 adolescentes (768 chicos y 755 chicas)
que tenían cumplimentados los datos dietéticos y los
parámetros antropométricos (peso, altura, circunferencias
de cintura, y 6 pliegues). Se calculó el IMC y el porcentaje
de grasa corporal. La dieta ha sido calculada a
partir de un recordatorio de 24h. Los sujetos fueron divididos
en grupos dependiendo de la cantidad de SSD que
consumían: 1) No consumidores (0 g de consumo SSD); 2)
Consumo moderado (< 336 g/día de SSD, equivalente a
una bebida al día de SSD); y 3) Consumo alto (> 336 g/día
de SSD).
Resultados: El 67% de los varones y el 75% de las
mujeres indican no consumir este tipo de bebidas el día
anterior a la encuesta. Los varones en general consumieron
más SSD que las mujeres. En cuanto a la asociación
entre consumo SSD y medidas antropométricas y de composición
corporal, no se encontraron diferencias significativas
entre los tres grupos de estudio en los parámetros
antropométricos, IMC o grasa corporal.
Conclusión: Dado que no se ha encontrado en este estudio
ninguna asociación entre el consumo de SSD y la obesidad,
sugerimos que los patrones y hábitos dietarios así
como los factores del estilo de vida, y la actividad física,
deberían tenerse en cuenta al examinar las relaciones
transversales o longitudinales con la obesidad, y que los estudios de intervención multidisciplinar son cruciales
cuando se trata de desarrollar soluciones contra el incremento
de una epidemia como la obesidad.The AVENA study was supported by Spanish Ministry
of Health (00/0015) and by grants from the Spanish Higher
Sports Council (05/UPB32/01, 09/UPB31/03 and
13/UPB20/04), the Spanish Ministry of Education
(AP2003-2128 and AP2004-2745), Coca-Cola, Panrico
SA, Madaus SA and Procter & Gamble SA
Physiological effects of toxic elements on a wild nightjar species
Nightjars are considered human-tolerant species due to the population densities reached in strongly managed landscapes. However, no studies have been done evaluating metal-related effects on physiology, condition or fitness in any nightjar species. The main aim of this study was to evaluate how metal exposure affects physiology and condition in red-necked nightjar (Caprimulgus ruficollis) populations inhabiting three different environments in southeastern Spain: agricultural-urban area (n = 15 individuals), mining area (n = 17) and control area (n = 16).Increased plasma mineral levels (magnesium and calcium) and alkaline phosphatase (ALP) activity were observed in breeding females, and ALP was significantly higher in young birds due to bone growth and development. In the mining-impacted environment, nightjars showed decreased retinol (17.3 and 23.6 mu M in the mining area and control area), uric acid (28.8 and 48.6 mg/dl in the mining area and control area) and albumin (16.2 and 19.6 g/l in the mining area and control area), probably impaired by a combination of toxic metal exposure and low prey quantity/quality in that area. Moreover, they showed increased plasma tocopherol levels (53.4 and 38.6 μM in the mining area and control area) which may be a response to cope with metal-induced oxidative stress and lipid peroxidation. Blood concentrations of toxic metals (As, Pb, Cd and Hg) were negatively associated with calcium, phosphorus, magnesium, ALP, total proteins and body condition index. This could lead to metal-related disorders in mineral metabolism and ALP activity that may potentially increase the risk of skeletal pathologies and consequent risk of fractures in the long term, compromising the survival of individuals. Further studies need to be carried out to evaluate potential metal-related effects on the antioxidant status and bone mineralization of nightjars inhabiting mining environments.</p
Predicting Acorn-Grass Weight Gain Index using non-destructive Near Infrared Spectroscopy in order to classify Iberian pig carcasses according to feeding regime
Predicción del Índice de Reposición en Montanera para la clasificación de canales de cerdo Ibérico según régimen alimenticio mediante el análisis no destructivo por Espectroscopía del Infrarrojo Cercano
The classification of Iberian pig carcasses into different commercial categories according to feeding regime was evaluated by means of a non-destructive analysis of the subcutaneous adipose tissue using Near Infrared Spectroscopy (NIRS). A quantitative approach was used to predict the Acorn-Grass Weight Gain Index (AGWGI), and a set of criteria was established for commercial classification purposes. A total of 719 animals belonging to various batches, reflecting a wide range of feeding regimes, production systems and years, were analyzed with a view to developing and evaluating quantitative NIRS models. Results for the external validation of these models indicate that NIRS made clear differentiation of batches as a function of three feeding regimes possible with high accuracy (Acorn, Recebo and Feed), on the basis of the mean representative spectra of each batch. Moreover, individual analysis of the animals showed a broad consensus between field inspection information and the classification based on the AGWGI NIRS prediction, especially for extreme categories (Acorn and Feed).La clasificación en distintas categorías comerciales según régimen alimenticio de canales de cerdo Ibérico fue evaluada mediante el análisis no destructivo de muestras de tejido adiposo subcutáneo por Espectroscopía del Infrarrojo Cercano (NIRS). Partiendo de una aproximación cuantitativa para predecir el Índice de Reposición en Montanera (IRM) se establecieron una serie de criterios para proceder a su clasificación comercial. Se analizaron un total de 719 animales pertenecientes a diversas partidas, que recogen una amplia variabilidad de muestras de distintos regímenes alimenticios, campañas y sistemas productivos, para el desarrollo y evaluación de los modelos NIRS cuantitativos. Los resultados de validación externa de los modelos indicaron que es posible discriminar con una gran exactitud entre partidas de distintos categorías (Bellota, Recebo y Cebo), en base al espectro medio representativo de cada partida. Además, el análisis individualizado de los animales mostró un amplio consenso entre la información recibida de campo y la clasificación en base a la predicción del parámetro IRM por NIRS, sobre todo para categorías con características extremas (Bellota y Cebo)
Toxic elements in blood of red-necked nightjars (Caprimulgus ruficollis) inhabiting differently polluted environments
Toxic metals have been widely reported in avian tissues due to their well-known accumulation capacity and adverse effects. However, rare earth elements (REE) and other minor elements (ME) are becoming a new threat due to their use in modern technology. Presently, exposure data are limited and no studies have been reported in wildlife. The order Caprimulgiformes is among the most understudied groups of birds lacking blood ecotoxicological data. One major constraint is the small blood sample volume that can be collected to ensure animal welfare, which limits analyses. In order to shed light on these collective issues, we sampled 48 red-necked nightjars (Caprimulgus ruficollis) inhabiting three different scenarios of contaminant exposure (agricultural-urban area, n = 15; mining area, n = 17; and control area, n = 16) in southeastern Spain, and report for the first time concentrations of 50 elements (i.e. trace elements, ATSDR’s list toxic elements, REE and ME) using a recently developed technique able to analyze them by ICP-MS in very small volumes of blood (130 μL). Concentrations of As, Cd, Pb and Mn were significantly higher in individuals captured at the mining area compared to the other sites. Lead levels in the mine site were of particular concern since it was in the range of blood concentrations related to subclinical/clinical effects in other species, and in our study were associated with decreased hematocrit values (up to 44% hematocrit depression at blood concentrations >1000 ng/ml w.w.). Moreover, additive effects related to metal cocktail exposure in the mining area could be expected. Age and gender-related differences in blood concentrations were found for some elements. Even though most REE and ME concentrations were close to the LOQ, some of these emerging contaminants may trigger sublethal effects that, together with the ATSDR’s list toxic elements, need to be carefully evaluated in a future study.</p
Strategic Recommendations for the Transnational Management of Invasive Alien Crayfish and Crabs in Iberian Inland Waters
An important goal of LIFE INVASAQUA is to develop tools that will improve management and increase the efficiency of the Early Warning and Rapid Response framework for Invasive Alien Species (IAS) in the Iberian Peninsula. We developed a participative process with experts in order to obtain Strategic Recommendations for the
transnational management of invasive alien crayfish and crabs in inland waters of Spain and Portugal. They promote the coordinated management between Spain and Portugal, in order to facilitate implementation of international commitments and best practices and to support development of policies and targets on IAS management
at Iberian scale. They were designed to serve as a guiding tool seeking to identify a strategic direction for the
Spanish and Portuguese governance that is already being developed. The resulting Strategic Recommendations
are important tools supporting the implementation of the IAS EU Regulation. Ultimately, the information included can be used for achieving the target of the EU Biodiversity Strategy to 2030 for combatting IAS, and also for
implementing of other EU policies with requirements on alien species, such as the Birds and Habitats Directives,
and the Marine Strategy and Water Framework Directives
Guide to the alien and invasive species of rivers, lakes and estuaries in the Iberian Peninsula.
Guide to the alien and invasive species of rivers, lakes and estuaries in the Iberian Peninsula
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
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