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1.
J Anim Ecol ; 93(4): 393-405, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38100230

RESUMO

Comprehending symbiont abundance among host species is a major ecological endeavour, and the metabolic theory of ecology has been proposed to understand what constrains symbiont populations. We parameterized metabolic theory equations to investigate how bird species' body size and the body size of their feather mites relate to mite abundance according to four potential energy (uropygial gland size) and space constraints (wing area, total length of barbs and number of feather barbs). Predictions were compared with the empirical scaling of feather mite abundance across 106 passerine bird species (26,604 individual birds sampled), using phylogenetic modelling and quantile regression. Feather mite abundance was strongly constrained by host space (number of feather barbs) but not by energy. Moreover, feather mite species' body size was unrelated to the body size of their host species. We discuss the implications of our results for our understanding of the bird-feather mite system and for symbiont abundance in general.


Assuntos
Doenças das Aves , Infestações por Ácaros , Ácaros , Passeriformes , Animais , Filogenia , Tamanho Corporal , Infestações por Ácaros/veterinária
2.
Sci Rep ; 13(1): 2545, 2023 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-36781888

RESUMO

A recurrent behavioral trait model to study adaptation to urban environments is the flight initiation distance (FID), measured as the distance at which animals flee from an approaching threat. It has previously been shown that urban birds display shorter FID than their non-urban (rural) counterparts. However, discerning whether this is the result of habituation to human presence and frequentation, or of ecological factors related to the size of the city (considered as "systemic habituation"), has not yet been addressed. In this study, we analyzed House Sparrow (Passer domesticus) FIDs in a network of 26 small towns and villages within the same region in northeastern Spain. Our aim was to relate FID to human population density and settlement size. If the habituation to human presence hypothesis was supported, we should expect FIDs to decrease with the density of the human population across the human settlements, since this type of habituation is related to the rate of human exposure and this is proportional to human density. However, if the systemic habituation hypothesis was supported, FIDs should instead relate to the size of the human settlements, as the abundance of predators, similarly to other ecological variables, is often proportional to the size of towns. Results showed House Sparrows to be bolder in larger human settlements, but not necessarily the ones with a higher density of human population. This supports the idea that the fact that urban birds display shorter FIDs than their rural counterparts is the result of systemic ecological factors rather than the results of a simple habituation to humans.


Assuntos
Adaptação Fisiológica , Aves , Animais , Humanos , Cidades , Espanha
3.
J Environ Manage ; 299: 113593, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34467866

RESUMO

Soil erosion and sediment transport are controlled by complex factors promoting variable responses in catchment's erosion rates and sediment yields. To mitigate eventual negative effects derived from altered fluxes, integrated catchment management plans should assess the sediment cascade from upstream erosive processes, sediment mobilization through hillslopes and within the channel, up to downstream sediment yields. This study links hydro-sedimentary dynamics with sediment fingerprinting source ascription in a mid-mountainous Mediterranean catchment during five hydrological years (2013-2018). Soil colour parameters and fallout radionuclides were used as tracers to predict dominant suspended sediment sources using (i) a Bayesian mixing model (MixSIAR) and (ii) an End Member Mixing Analysis (EMMA). MixSIAR suggested that crops were the dominant source in most of the collected samples. EMMA showed similar results, clustering all except one sediment samples close to the crop and channel bank signatures. In addition, a quantitative hysteresis index was calculated and floods were clustered in function of their hydro-sedimentary characteristics. Despite different patterns were associated to each of the four identified clusters (e.g. different sediment loads and maximum suspended sediment concentrations), correlation between sediment origin and hydro-sedimentary variables was not significant due to the little seasonal variation in source type ascription.


Assuntos
Sedimentos Geológicos , Solo , Teorema de Bayes , Monitoramento Ambiental , Inundações , Radioisótopos
4.
Talanta ; 206: 120224, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514858

RESUMO

This paper presents a fast and automatic flow-based method to extract 131I from biological samples and hospital waste, previous to liquid scintillation detection. 131I is a radionuclide extensively used in Nuclear Medicine due to their beta and gamma disintegrations, whereby hospitals have to manage the associated waste generation. The automatic developed system is based on Lab-On-Valve (LOV) flow-technique exploiting Cl-resin (135 mg per extraction). This methodology allows performing sample extractions and measurements on the same day, since the extraction frequency takes 1.4-4 h-1, depending on the analysed sample volume, plus up to 2 h of measurement for each vial. 131I is retained as iodine ion and eluted with sodium sulphide 0.2 mol L-1. The maximum sample volume that can be preconcentrated is 20 mL, reaching an extraction efficiency of 85 ±â€¯5%. The minimum detectable activity (MDA) is 0.05 Bq, showing a precision of 7% RSD (n = 5). Both, biological samples (urine and saliva) and hospital waste samples can be satisfactorily analysed by the proposed system, obtaining recoveries between 90 and 110%. The developed method is then suitable to implement in hospitals, improving the surveillance of the 131I environmental release.


Assuntos
Análise de Injeção de Fluxo/métodos , Hospitais/provisão & distribuição , Radioisótopos do Iodo/análise , Resíduos de Serviços de Saúde/análise , Contagem de Cintilação/métodos , Humanos , Radioisótopos do Iodo/urina , Saliva/química
5.
Nat Commun ; 10(1): 3109, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31337752

RESUMO

Biological responses to climate change have been widely documented across taxa and regions, but it remains unclear whether species are maintaining a good match between phenotype and environment, i.e. whether observed trait changes are adaptive. Here we reviewed 10,090 abstracts and extracted data from 71 studies reported in 58 relevant publications, to assess quantitatively whether phenotypic trait changes associated with climate change are adaptive in animals. A meta-analysis focussing on birds, the taxon best represented in our dataset, suggests that global warming has not systematically affected morphological traits, but has advanced phenological traits. We demonstrate that these advances are adaptive for some species, but imperfect as evidenced by the observed consistent selection for earlier timing. Application of a theoretical model indicates that the evolutionary load imposed by incomplete adaptive responses to ongoing climate change may already be threatening the persistence of species.


Assuntos
Aclimatação/fisiologia , Aves/fisiologia , Mudança Climática , Fenótipo , Animais , Seleção Genética/fisiologia , Fatores de Tempo
6.
Anal Chem ; 89(11): 5857-5863, 2017 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-28478682

RESUMO

99Tc is an artificial beta emitter widely used in nuclear medicine for diagnostic tests. A fully automated and rapid system for 99Tc monitoring is introduced with the aim to improve hospital residues management. This system can also be helpful for controlling urban wastewater. Figures of merit similar to those obtained with liquid scintillation counting were achieved by exploiting a simple, economic, and portable system with spectrophotometric detection. The combination of flow analysis techniques, i.e., lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA), with a selective resin ((weak base extraction chromatographic (WBEC) resin) enables the analysis to be performed in a short time, achieving high selectivity and sensitivity levels. After elution with NH4OH (3 mol·L-1), 99Tc is derivatized with 1,5-diphenylcarbohydrazide (DPC) and finally detected by a miniaturized fiber optic CCD spectrophotometer at 520 nm, exploiting a long path-length liquid waveguide capillary cell (LWCC) of 100 cm path length. The proposed method was optimized by experimental design, achieving a limit of detection (LOD) of 4 ng of 99Tc (2.5 Bq), a reproducibility of 6%, and a resin durability of 78 injections. The microcolumn allows one to preconcentrate up to 100 mL of sample without deterioration of the analytical signal. The automated system was successfully applied to hospital residues and urban wastewater, and the attained recoveries were between 90% and 110%.


Assuntos
Monitoramento Ambiental/métodos , Tecnécio/análise , Gerenciamento de Resíduos/métodos , Águas Residuárias/análise , Automação/métodos , Hospitais , Limite de Detecção , Urbanização
7.
Talanta ; 167: 398-403, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28340738

RESUMO

The release of 226Ra from phosphogypsum (PG) was evaluated by developing a novel tool for fully automated 226Ra lixiviation from PG integrating extraction/pre-concentration using a renewable sorbent format. Eight leached fractions (30mL each one) and a residual fraction were analyzed allowing the evaluation of dynamic lixiviation of 226Ra. An automatic system allows this approach coupling a homemade cell with a 226Ra extraction/pre-concentration method, which is carried out combining two procedures: Ra adsorption on MnO2 and its posterior co-precipitation with BaSO4. Detection was carried out with a low-background proportional counter, obtaining a minimum detectable activity of 7Bqkg-1. Method was validated by analysis of a PG reference material (MatControl CSN-CIEMAT 2008), comparing the content found in fractions (sum of leached fractions + residual fraction) to the reference value. PG samples from Huelva (Spain) were studied. 226Ra average activity concentration of the sum of leached fractions with artificial rainwater at pH 5.4±0.2 was 105±3Bqkg-1d.w. representing a 226Ra lixiviation of 37%; while at pH 2.0±0.2, it was 168±3Bqkg-1 d.w., which represents a 50%. Also, static lixiviation, maintaining the same experimental conditions, was carried out indicating that, for both considered pH, the 226Ra release from PG is up to 50% higher in a dynamic leaching that in a static one, may have both environmental and reutilization implications.


Assuntos
Sulfato de Cálcio/química , Fósforo/química , Rádio (Elemento)/isolamento & purificação , Extração em Fase Sólida/métodos , Automação , Rádio (Elemento)/análise , Reprodutibilidade dos Testes
8.
Chemosphere ; 152: 481-9, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27003370

RESUMO

Measurements of airbone radionuclides (7)Be and gross beta (Aß) jointly with atmospheric aerosols, i.e. particulate matter (PM) were routinely carried out for 10 years (2004-2014) at the University of the Balearic Islands, Spain. A total of 728 filter (0.8 µm pore size) samples were collected, and in all of them (7)Be and Aß specific activities were detected. The maximum and minimum specific activities monitored were 0.73 ± 0.41 - 15.8 ± 1.26 mBq m(-3) of (7)Be and 0.14 ± 0.02 - 2.55 ± 0.04 mBq m(-3) of Aß. PM concentrations were also determined, showing seasonal behavior with the highest concentration in summer and the lowest one in winter. Several meteorological parameters have been considered to explain this intra-annual variation. Principal component analysis (PCA) was applied to the dataset indicating that it is well represented by two principal components that explain 76.6% of total variance. Additionally, a second study with preliminary results of the specific activities of two natural radiotracers ((7)Be and (210)Pb) in PM10 samples was carried out. They were monitored for two years (2013-2015) in air of Mallorca Island. (7)Be and (210)Pb were detected in most of the PM10 filters, in 100% and 93% of them, respectively. The relationship between activities of both radionuclides and several relevant meteorological parameters was established at 95% confidence level. As a common result to PM and PM10 samples, a strong positive correlation between the evaluated radionuclides and temperature was found.


Assuntos
Poluentes Atmosféricos/análise , Berílio/análise , Material Particulado/análise , Radioisótopos/análise , Aerossóis/análise , Monitoramento Ambiental , Ilhas , Chumbo/análise , Estações do Ano , Espanha
9.
Anal Chim Acta ; 911: 75-81, 2016 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-26893088

RESUMO

An automatic system based on multisyringe flow injection analysis (MSFIA) and lab-on-valve (LOV) flow techniques for separation and pre-concentration of (226)Ra from drinking and natural water samples has been developed. The analytical protocol combines two different procedures: the Ra adsorption on MnO2 and the BaSO4 co-precipitation, achieving more selectivity especially in water samples with low radium levels. Radium is adsorbed on MnO2 deposited on macroporous of bead cellulose. Then, it is eluted with hydroxylamine to transform insoluble MnO2 to soluble Mn(II) thus freeing Ra, which is then coprecipitated with BaSO4. The (226)Ra can be directly detected in off-line mode using a low background proportional counter (LBPC) or through a liquid scintillation counter (LSC), after performing an on-line coprecipitate dissolution. Thus, the versatility of the proposed system allows the selection of the radiometric detection technique depending on the detector availability or the required response efficiency (sample number vs. response time and limit of detection). The MSFIA-LOV system improves the precision (1.7% RSD), and the extraction frequency (up to 3 h(-1)). Besides, it has been satisfactorily applied to different types of water matrices (tap, mineral, well and sea water). The (226)Ra minimum detectable activities (LSC: 0.004 Bq L(-1); LBPC: 0.02 Bq L(-1)) attained by this system allow to reach the guidance values proposed by the relevant international agencies e.g. WHO, EPA and EC.


Assuntos
Radiometria/métodos , Rádio (Elemento)/isolamento & purificação , Poluentes Radioativos da Água/isolamento & purificação , Rádio (Elemento)/análise , Contagem de Cintilação , Poluentes Radioativos da Água/análise
10.
Anal Bioanal Chem ; 407(19): 5571-8, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26007698

RESUMO

A new approach exploiting in-syringe dispersive liquid-liquid microextraction (DLLME) for (99)Tc extraction and preconcentration from biological samples, i.e., urine and saliva, and liquid residues from treated patients is presented. (99)Tc is a beta emitter with a long half-life (2.111 × 10(5) years) and mobility in the different environmental compartments. One of the sources of this radionuclide is through the use of its father (99m)Tc in medical diagnosis. For the first time a critical comparison between extractants and disperser solvents for (99)Tc DLLME is presented, e.g., tributyl phosphate (TBP), trioctylmethylammonium chloride (Aliquat®336), triisooctylamine (TiOA), as extractants in apolar solvents such as xylene and dodecane, and disperser solvents such as acetone, acetonitrile, ethanol, methanol, 1-propanol, and 2-propanol. The system was optimized by experimental design, and 22.5% of Aliquat®336 in acetone was selected as extractant and disperser, respectively. Off-line detection was performed using a liquid scintillation counter. The present method has a (99)Tc minimum detectable activity (MDA) of 0.075 Bq with a high extraction/preconcentration frequency (8 h(-1)). Urine, saliva, and hospital residues were satisfactorily analyzed with recoveries of 82-119%. Thus, the proposed system is an automatic powerful tool to monitor the entry of (99)Tc into the environment. Graphical Abstract (99m)Tc is widely used in Nuclear Medicine for diagnosis. Its daugther (99)Tc is automatically monitored in biological samples from treated patients by in-syringe dispersive liquid-liquid microextraction.


Assuntos
Automação , Microextração em Fase Líquida/instrumentação , Contagem de Cintilação , Tecnécio/análise , Humanos , Recursos Humanos em Hospital , Tecnécio/sangue , Tecnécio/urina
11.
Ecol Evol ; 5(1): 59-72, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25628864

RESUMO

Climate change is expected to affect natural populations in many ways. One way of getting an understanding of the effects of a changing climate is to analyze time series of natural populations. Therefore, we analyzed time series of 25 and 20 years, respectively, in two populations of the citril finch (Carduelis citrinella) to understand the background of a dramatic increase in wing length in this species over this period, ranging between 1.3 and 2.9 phenotypic standard deviations. We found that the increase in wing length is closely correlated to warmer winters and in one case to rain in relation to temperature in the summer. In order to understand the process of change, we implemented seven simulation models, ranging from two nonadaptive models (drift and sampling), and five adaptive models with selection and/or phenotypic plasticity involved and tested these models against the time series of males and females from the two population separately. The nonadaptive models were rejected in each case, but the results were mixed when it comes to the adaptive models. The difference in fit of the models was sometimes not significant indicating that the models were not different enough. In conclusion, the dramatic change in mean wing length can best be explained as an adaptive response to a changing climate.

12.
PLoS One ; 9(9): e107341, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25216248

RESUMO

Understanding why host species differ so much in symbiont loads and how this depends on ecological host and symbiont traits is a major issue in the ecology of symbiosis. A first step in this inquiry is to know whether observed differences among host species are species-specific traits or more related with host-symbiont environmental conditions. Here we analysed the repeatability (R) of the intensity and the prevalence of feather mites to partition within- and among-host species variance components. We compiled the largest dataset so far available: 119 Paleartic passerine bird species, 75,944 individual birds, ca. 1.8 million mites, seven countries, 23 study years. Several analyses and approaches were made to estimate R and adjusted repeatability (R(adj)) after controlling for potential confounding factors (breeding period, weather, habitat, spatial autocorrelation and researcher identity). The prevalence of feather mites was moderately repeatable (R = 0.26-0.53; R(adj) = 0.32-0.57); smaller values were found for intensity (R = 0.19-0.30; R(adj )= 0.18-0.30). These moderate repeatabilities show that prevalence and intensity of feather mites differ among species, but also that the high variation within species leads to considerable overlap among bird species. Differences in the prevalence and intensity of feather mites within bird species were small among habitats, suggesting that local factors are playing a secondary role. However, effects of local climatic conditions were partially observed for intensity.


Assuntos
Doenças das Aves/epidemiologia , Plumas/parasitologia , Infestações por Ácaros/epidemiologia , Simbiose , Animais , Doenças das Aves/parasitologia , Ecossistema , Interações Hospedeiro-Parasita , Ácaros/patogenicidade , Passeriformes/parasitologia , Especificidade da Espécie
13.
Naturwissenschaften ; 96(7): 797-801, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19357818

RESUMO

Carotenoids may provide numerous health benefits and are also responsible for the integumentary coloration of many bird species. Despite their importance, many aspects of their metabolism are still poorly known, and even basic issues such as the anatomical sites of conversion remain controversial. Recent studies suggest that the transformation of carotenoid pigments takes place directly in the follicles during feather growth, even though the liver has been previously recognised as a storing organ for these pigments with a certain potential for conversion. In this context, we analysed the carotenoid profile of plasma, liver, skin and feathers of male Common Crossbills (Loxia curvirostra). Interestingly, the derivative feather pigment 3-hydroxy-echinenone was detected in the liver and in the bloodstream (i.e. the necessary vehicle to transport metabolites to colorful peripheral tissues). Our results demonstrate for the first time with empirical data that the liver may act as the main site for the synthesis of integumentary carotenoids. This finding contradicts previous assumptions and raises the question of possible inter-specific differences in the site of carotenoid conversion in birds.


Assuntos
Carotenoides/metabolismo , Fígado/metabolismo , Passeriformes/metabolismo , Pigmentação/fisiologia , Pele/metabolismo , Envelhecimento/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Plumas/metabolismo , Masculino , Passeriformes/crescimento & desenvolvimento
14.
Biol Lett ; 2(1): 85-7, 2006 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-17148333

RESUMO

It is well known theoretically that gene flow can impede genetic differentiation between populations. In this study, we show that in a highly mobile bird species, where dispersal is well documented, there is a strong genetic and morphological differentiation over a very short geographical scale (less than 5 km). Allocation tests revealed that birds caught in one area were assigned genetically to the same area with a very high probability, in spite of current gene flow. Populations were also morphologically differentiated. The results suggest that the relationship between gene flow and differentiation can be rather complicated and non-intuitive.


Assuntos
Canários/anatomia & histologia , Canários/genética , Fluxo Gênico , Variação Genética , Migração Animal , Animais
15.
Med. clín (Ed. impr.) ; 114(14): 538-539, abr. 2000.
Artigo em Es | IBECS | ID: ibc-6418

RESUMO

Fundamento: Valorar si el fútbol televisado influye en la utilización del servicio de urgencias. Pacientes y métodos: Se recogieron el número, las características demográficas y la gravedad de los pacientes atendidos durante la retransmisión de partidos del FC Barcelona durante la Liga de Campeones (n = 12), y se compararon con los días sin fútbol televisado (n = 12). Resultados: El fútbol televisado se asoció a un descenso de visitas (-18 por ciento; p = 0,002). Dicho descenso afectó a todas las unidades de urgencias, aunque éste sólo fue significativo para la de traumatología (-28 por ciento; p = 0,006). El menor número de visitas se debió a un descenso de las generadas por problemas menores (-30 por ciento; p = 0,04). Conclusión: Existe una menor utilización de los servicios de urgencias asociada con la retransmisión televisada de partidos de fútbol. (AU)


Assuntos
Adulto , Masculino , Feminino , Humanos , Televisão , Futebol Americano , Espanha , Modelos Teóricos , Interpretação Estatística de Dados , Serviços Médicos de Emergência
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