Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
1.
Nat Ecol Evol ; 7(1): 92-101, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36471120

RESUMEN

There have been recent renewed commitments to increase the extent of protected areas to combat the growing biodiversity crisis but the underpinning evidence for their effectiveness is mixed and causal connections are rarely evaluated. We used data gathered by three large-scale citizen science programmes in the UK to provide the most comprehensive assessment to date of whether national (Sites of Special Scientific Interest) and European (Special Protection Areas/Special Areas of Conservation) designated areas are associated with improved state (occurrence, abundance), change (rates of colonization, persistence and trend in abundance), community structure and, uniquely, demography (productivity) on a national avifauna, while controlling for differences in land cover, elevation and climate. We found positive associations with state that suggest these areas are well targeted and that the greatest benefit accrued to the most conservation-dependent species since positive associations with change were largely restricted to rare and declining species and habitat specialists. We suggest that increased productivity provides a plausible demographic mechanism for positive effects of designation.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Animales , Ecosistema , Aves , Reino Unido
2.
Nat Commun ; 12(1): 6217, 2021 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-34728617

RESUMEN

Natural sounds, and bird song in particular, play a key role in building and maintaining our connection with nature, but widespread declines in bird populations mean that the acoustic properties of natural soundscapes may be changing. Using data-driven reconstructions of soundscapes in lieu of historical recordings, here we quantify changes in soundscape characteristics at more than 200,000 sites across North America and Europe. We integrate citizen science bird monitoring data with recordings of individual species to reveal a pervasive loss of acoustic diversity and intensity of soundscapes across both continents over the past 25 years, driven by changes in species richness and abundance. These results suggest that one of the fundamental pathways through which humans engage with nature is in chronic decline, with potentially widespread implications for human health and well-being.


Asunto(s)
Acústica , Aves/fisiología , Vocalización Animal/fisiología , Animales , Biodiversidad , Aves/clasificación , Conservación de los Recursos Naturales , Europa (Continente) , Humanos , América del Norte , Dinámica Poblacional , Estaciones del Año , Sonido , Vocalización Animal/clasificación
3.
Mult Scler Relat Disord ; 24: 3-10, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29860199

RESUMEN

The UK Multiple Sclerosis Register (UKMSR) is a large cohort study designed to capture 'real world' information about living with multiple sclerosis (MS) in the UK from diverse sources. The primary source of data is directly from people with Multiple Sclerosis (pwMS) captured by longitudinal questionnaires via an internet portal. This population's diagnosis of MS is self-reported and therefore unverified. The second data source is clinical data which is captured from MS Specialist Treatment centres across the UK. This includes a clinically confirmed diagnosis of MS (by Macdonald criteria) for consented patients. A proportion of the internet population have also been consented at their hospital making comparisons possible. This dataset is called the 'linked dataset'. The purpose of this paper is to examine the characteristics of the three datasets: the self-reported portal data, clinical data and linked data, in order to assess the validity of the self-reported portal data. The internet (n = 11,021) and clinical (n = 3,003) populations were studied for key shared characteristics. We found them to be closely matched for mean age at diagnosis (clinical = 37.39, portal = 39.28) and gender ratio (female %, portal = 73.1, clinical = 75.2). The Two Sample Kolmogorov-Smirnov test was for the continuous variables to examine is they were drawn from the same distribution. The null hypothesis was rejected only for age at diagnosis (D = 0.078, p < 0.01). The populations therefore, were drawn from different distributions, as there are more patients with relapsing disease in the clinical cohort. In all other analyses performed, the populations were shown to be drawn from the same distribution. Our analysis has shown that the UKMSR portal population is highly analogous to the entirely clinical (validated) population. This supports the validity of the self-reported diagnosis and therefore that the portal population can be utilised as a viable and valid cohort of people with Multiple Sclerosis for study.


Asunto(s)
Esclerosis Múltiple/epidemiología , Sistema de Registros , Adulto , Femenino , Humanos , Internet , Masculino , Persona de Mediana Edad , Autoinforme , Reino Unido
4.
Ecotoxicology ; 14(8): 895-923, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16328714

RESUMEN

Long term exposure of skylarks to a fictitious insecticide and of wood mice to a fictitious fungicide were modelled probabilistically in a Monte Carlo simulation. Within the same simulation the consequences of exposure to pesticides on reproductive success were modelled using the toxicity-exposure-linking rules developed by R.S. Bennet et al. (2005) and the interspecies extrapolation factors suggested by R. Luttik et al. (2005). We built models to reflect a range of scenarios and as a result were able to show how exposure to pesticide might alter the number of individuals engaged in any given phase of the breeding cycle at any given time and predict the numbers of new adults at the season's end.


Asunto(s)
Contaminantes Ambientales/toxicidad , Modelos Estadísticos , Plaguicidas/toxicidad , Reproducción/efectos de los fármacos , Animales , Aves , Exposición a Riesgos Ambientales , Ratones , Método de Montecarlo , Medición de Riesgo , Tiempo , Triticum
5.
Ecotoxicology ; 14(8): 877-93, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16328715

RESUMEN

In the European Union, first-tier assessment of the long-term risk to birds and mammals from pesticides is based on calculation of a deterministic long-term toxicity/exposure ratio (TER(lt)). The ratio is developed from generic herbivores and insectivores and applied to all species. This paper describes two case studies that implement proposed improvements to the way long-term risk is assessed. These refined methods require calculation of a TER for each of five identified phases of reproduction (phase-specific TERs) and use of adjusted No Observed Effect Levels (NOELs) to incorporate variation in species sensitivity to pesticides. They also involve progressive refinement of the exposure estimate so that it applies to particular species, rather than generic indicators, and relates spraying date to onset of reproduction. The effect of using these new methods on the assessment of risk is described. Each refinement did not necessarily alter the calculated TER value in a way that was either predictable or consistent across both case studies. However, use of adjusted NOELs always reduced TERs, and relating spraying date to onset of reproduction increased most phase-specific TERs. The case studies suggested that the current first-tier TER(lt )assessment may underestimate risk in some circumstances and that phase-specific assessments can help identify appropriate risk-reduction measures. The way in which deterministic phase-specific assessments can currently be implemented to enhance first-tier assessment is outlined.


Asunto(s)
Exposición a Riesgos Ambientales , Contaminantes Ambientales/toxicidad , Plaguicidas/toxicidad , Reproducción/efectos de los fármacos , Animales , Aves , Productos Agrícolas , Grano Comestible , Mamíferos , Nivel sin Efectos Adversos Observados , Poaceae , Medición de Riesgo/métodos , Tiempo
6.
Environ Monit Assess ; 12(1): 67-82, 1989 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24249067

RESUMEN

Eggs were collected from seven seabird species at colonies on the British Columbia coast from 1983 to 1986 and analyzed for organochlorine contaminants. Total PCB levels (wet weight) were highest in double-crested cormorants (Phalacrocorax auritus) from the Fraser estuary (2.91 mg kg(-1)) and the Strait of Georgia (3.79 mg kg(-1)). Highest DDE levels were in fork-tailed storm-petrels (Oceanodroma furcata) from the Queen Charlotte Islands (1.68 mg kg(-1)). Organochlorine levels were generally lower in eggs from the mid 1980s than in those collected in the early 1970s. Organochlorine levels in Pacific alcids and hydrobatids foraging in offshore locations were compared to those in the same or ecologically similar species from the Canadian Atlantic coast. DDT- and HCH-related compounds were higher in Pacific populations while levels of dieldrin, oxychlordane, and HCB were generally lower. With the exception of ß-HCH, levels of all measured organochlorines were lower in cormorants breeding in the Fraser River estuary than in cormorants from the St. Lawrence River estuary on the Atlantic coast.

7.
Arch Environ Contam Toxicol ; 33(4): 430-5, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9419262

RESUMEN

Thick-billed murres (Uria lomvia) originating from breeding colonies in the Canadian Arctic were collected on their wintering grounds off the coast of Newfoundland. Murres had been previously banded such that the age of each bird could be determined upon collection. This allowed us to explore the possible relationships between age and contaminant levels in the thick-billed murre. Samples of breast muscle were analyzed for organochlorines (chlorobenzenes, hexachlorocyclohexanes, DDTs, chlordanes, mirex, dieldrin, and PCBs) and metals (selenium, cadmium, mercury, and lead). Levels of both organochlorine and metal residues were sufficiently low so that toxic effects were unlikely. First-year birds contained lower levels of DDTs, mirex, dieldrin, and PCBs compared with older birds, reflecting lower levels of contamination of these compounds in food chains at breeding colonies located at higher latitudes. Higher levels of chemical residues in older birds may reflect greater direct input of those organochlorines into the wintering grounds via the highly contaminated St. Lawrence River. Levels of chlorobenzenes, hexachlorocyclohexanes, and chlordanes, which reflect atmospheric deposition, were not detected at higher levels in older birds. Of the metals, only cadmium was detected at higher levels in older birds.


Asunto(s)
Envejecimiento/metabolismo , Aves/metabolismo , Hidrocarburos Clorados , Insecticidas/análisis , Metales Pesados/análisis , Músculos/química , Animales , Regiones Árticas , Canadá
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA