54 research outputs found

    Biased adult sex ratios in Western Europe populations of Little Bustard Tetrax tetrax as a potential warning signal of unbalanced mortalities

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    Adult sex ratios (ASRs) have proved to correlate with population trends, which make them potential useful indicators of a species’ population trajectory and conservation status. We analysed ASRs and proportion of juveniles in flocks of an endangered steppe bird, the Little Bustard Tetrax tetrax, using surveys made during the non-breeding period in seven areas within its Western European range (one in Portugal, four in Spain, and two in France). We found overall male-biased ASRs, as all the seven surveyed areas showed a male-biased ASR mean value. Five areas were below the threshold median value (female sex ratio = 0.4) considered to be consistent with an increased probability of extinction, according to earlier population viability analyses for the species.Wealso found a significant positive correlation between female ratio and the proportion of young individuals in the non-breeding flocks surveyed. Our results (strongly male-biased ASRs) support the hypothesis that the viability of Little Bustard populations in Western Europe is threatened by an excess of female mortality, something that should be quantified in the future, and emphasise the value of monitoring sex ratio as a population viability indicator in species where monitoring survival is difficult to achieve.Comunidad de Madrid S2013/MAE-2719 S2013/MAE2719Ministry of Science and Innovation, Spain (MICINN) Spanish Governmen

    A wintering waterbird community in an artificial wetland: Laguna de Meco

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    [EN]: The progressive loss of natural wetlands throughout Europe has led to the use of human infrastructures such as gravel pits, irrigation ponds and reservoirs by waterbirds as an alternative habitat. In Central Spain, the presence of man-made wetlands is essential for waterfowl conservation. The temporal dynamics of the wintering waterbird community was studied in an artificial wetland located in Madrid, Central Spain (Laguna de Meco). We carried out fortnightly censuses between October 2011 and February 2012 (total of 10) to describe variations in patterns of abundance and of species and taxonomic group richness. A total of 27 aquatic species and 2,901 birds were recorded. Diversity, number of birds and species richness varied between months. The highest numbers of birds occurred in October and February, while the greatest diversity and species richness were recorded during the postnuptial migration in October and November due to the large number of shorebirds occurring in those months. The most abundant species over the study period was the Common Coot Fulica atra, with 38% of the total birds counted, the only exception being the last half of February when the Black-headed Gull Chroicocephalus ridibundus was commonest. Despite only having been created in 2008, this lagoon hosts one of the most important waterfowl communities in Madrid and plays a crucial role in shorebird migration and waterbird conservation in the area. The information provided here could be useful for management strategies in this artificial wetland, which include protecting the lagoon and discarding the idea of moving it to a nearby area.[CA]: La pèrdua progressiva de zones humides naturals fa que les aus aquàtiques facin servir cada cop més, com a hàbitats alternatius, infraestructures humanes, com graveres, basses de reg o embassaments. Al centre d’Espanya, la presència de zones humides d’origen humà és fonamental per a la conservació de les aus aquàtiques. Es va estudiar la dinàmica temporal de la comunitat d’aus aquàtiques hivernants en un aiguamoll artificial de Madrid, la llacuna de Meco. Es van dur a terme deu censos quinzenals entre octubre de 2011 i febrer de 2012 amb l’objectiu de descriure el patró de variació temporal en l’abundància i riquesa de les espècies i grups taxonòmics. Es van detectar un total de 102 espècies, 27 de les quals eren aquàtiques, amb un total de 2.901 aus censades. La diversitat, el nombre d’aus i la riquesa d’espècies va variar entre mesos. Els valors més alts d’abundància d’individus es van obtenir a l’octubre i febrer, mentre que la major diversitat i riquesa d’espècies es van donar durant la migració postnupcial a l’octubre i novembre, a causa del gran nombre de limícoles presents en aquells mesos. L’espècie més abundant durant tot el període d’estudi va ser la Fotja Vulgar Fulica atra, que va suposar el 38% total dels individus censats, exceptuant la segona meitat de febrer durant la qual l’espècie més abundant va ser la Gavina Vulgar Chroicocephalus ridibundus. La llacuna de Meco, en només quatre anys des de la seva creació, ha estat capaç d’albergar una de les comunitats d’aus aquàtiques més importants de Madrid. La presència i estructura d’aquesta llacuna juga un paper clau per a les limícoles en migració i per a la conservació de les aus aquàtiques a la regió. Els resultats d’aquest estudi proporcionen informació útil per a la gestió d’aquesta zona humida artificial, com la seva protecció en lloc de la seva translocació a una zona propera a causa de l’ampliació de les infraestructures que l’envolten.[ES]: La pérdida progresiva de humedales naturales ha hecho que las aves acuáticas usen cada vez más, como hábitats alternativos, infraestructuras humanas, tales como graveras, balsas de riego o embalses. En el centro de España, la presencia de humedales de origen humano es fundamental para la conservación de las aves acuáticas. Se estudió la dinámica temporal de la comunidad de aves acuáticas invernantes en un humedal artificial de Madrid, la laguna de Meco. Se llevaron a cabo diez censos quincenales entre octubre de 2011 y febrero de 2012, con objeto de describir el patrón de variación temporal en la abundancia y riqueza de las especies y grupos taxonómicos. Se registraron un total de 102 especies, 27 de ellas acuáticas, con un total de 2.901 aves censadas. Los valores más altos de abundancia de individuos se obtuvieron en octubre y febrero, mientras que la mayor diversidad y riqueza de especies se dieron durante la migración postnupcial en octubre y noviembre, debido al gran número de limícolas presentes en aquellos meses. La especie más abundante durante todo el periodo de estudio fue la Focha Común Fulica atra, que supuso el 38% total de los individuos censados, exceptuando la segunda mitad de febrero en que la especie más abundante fue la Gaviota Reidora Chroicocephalus ridibundus. La laguna de Meco, en tan solo cuatro años de existencia, ha sido capaz de albergar una de las comunidades de aves acuáticas más importantes de Madrid. La presencia y estructura de esta laguna juega un papel clave para las limícolas en migración y para la conservación de las aves acuáticas en la región. Los resultados de este estudio proporcionan información útil para la gestión de este humedal, como su protección en vez de la translocación a una zona cercana debido a la ampliación de las infraestructuras que la rodean.Peer Reviewe

    El valor de los humedales artificiales: el caso de la laguna de Meco

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    Póster presentado en el XXII Congreso Español de Ornitología, celebrado en Madrid en diciembre de 2014.La pérdida progresiva de humedales naturales ha hecho que las aves acuáticas usen cada vez más hábitats alternativos de origen antrópico, como graveras, balsas de riego o embalses. La laguna de Meco, de origen artificial y situada en el noreste de la Comunidad de Madrid, se ha convertido en uno de los humedales de mayor importancia de la región. Se llevaron a cabo censos quincenales durante la migración e invernada de 2011- 2012 y la reproducción de 2014 para describir el patrón de variación temporal en la abundancia y riqueza de especies y de los principales grupos taxonómicos y la diversidad (índice inverso de Simpson).Peer reviewe

    Habitat fragmentation influences nestling growth in Mediterranean blue and great tits

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    In patchy forest areas, the size of the forest patch where birds breed has a strong influence on their breeding success. However, the proximate effects contributing to lowering the breeding success in small forest patches remain unclear; and a shortage of crucial resources in those forest patches has been suggested to account in some degree for this failure. With the aim to further investigate this issue, we have monitored the breeding cycle of blue and great tits in three ‘large’ forest patches (ranging between 26.5-29.6 ha) and twelve ‘small’ forest patches (ranging between 1.1-2.1 ha) in a Mediterranean area in central Spain, during three years (2011-2013). We also recorded the nestling diet inside the nest-boxes with the aid of handy-cams. Only males significantly differed between forest patch size categories; being on average younger and with better body condition in small patches for great and blue tits respectively. Reproductive traits did not vary between forest patch size categories, but the body condition of blue tit nestlings and the size of great tit nestlings did, being significantly better and larger respectively in large forest patches. The recruitment rate of blue tit nestlings was also higher in large patches. Regarding nestling diet, blue tits did not differ but great tits did, delivering a larger amount of caterpillars in large forest patches. Most variation in the reproductive traits occurred between years, probably due to annual differences in environmental conditions. This study suggests that food supply could be limiting the breeding success of birds above all in small patches, but also in large patches under particular environmental conditions.Funding was provided by Ministerio de Ciencia e Innovación (CGL2010-21933-C02-01) and Junta de Comunidades de Castilla-La Mancha and European Social Fund (POIC10-0269-7632). ESF and JBE are both supported by a doctoral scholarship from Junta de Comunidades de Castilla-La Mancha-European Social Fund. RB benefited from the JCCM-FSE 2007/2013 postdoctoral program and from a “Juan de la Cierva” post-doctoral contract (JCI-2011-10945) and ESD enjoyed a pre-doctoral fellowship from Ministerio de Ciencia e Innovación.Peer reviewe

    Short-term effects of a wildfire on the endangered Dupont’s Lark Chersophilus duponti in an arid shrub-steppe of central Spain

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    In Europe, Dupont’s Lark Chersophilus duponti is a threatened open-habitat bird. Prescribed burning has sometimes been proposed for its conservation, but without evidence of its effectiveness. To evaluate the short-term effects of a summer wildfire on this species, we performed several transect counts in the burnt and unburnt parts of a shrubsteppe in central Spain. The same transects were counted within a three-year interval prior to the fire and were repeated during the first two springs after the fire. We also measured the vegetation during the first two springs after the fire. In the burnt area, we observed a decrease of about 85–100% in Dupont’s Lark abundance, and about 7–15% in the control area. The disappearance of the scrub cover after fire and its slow regeneration, as well as the large increase in grass cover during the second year, may explain the decrease in this habitat-specialist bird species. Fire should be avoided in areas occupied by the Dupont’s Lark, as its negative effects in the short-term may cause local extinctions. However, prescribed burning may be used in neighboring areas to create new open habitats that may be subsequently colonized by this species.Peer Reviewe

    Short-Term Effects of a Wildfire on the Endangered Dupont's Lark Chersophilus duponti in an Arid Shrub-Steppe of Central Spain

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    In Europe, Dupont’s Lark Chersophilus duponti is a threatened open-habitat bird. Prescribed burning has sometimes been proposed for its conservation, but without evidence of its effectiveness. To evaluate the short-term effects of a summer wildfire on this species, we performed several transect counts in the burnt and unburnt parts of a shrubsteppe in central Spain. The same transects were counted within a three-year interval prior to the fire and were repeated during the first two springs after the fire. We also measured the vegetation during the first two springs after the fire. In the burnt area, we observed a decrease of about 85–100% in Dupont’s Lark abundance, and about 7–15% in the control area. The disappearance of the scrub cover after fire and its slow regeneration, as well as the large increase in grass cover during the second year, may explain the decrease in this habitat-specialist bird species. Fire should be avoided in areas occupied by the Dupont’s Lark, as its negative effects in the short-term may cause local extinctions. However, prescribed burning may be used in neighboring areas to create new open habitats that may be subsequently colonized by this species

    Biased sex ratios in Western Europe populations of little bustard (Tetrax tetrax) as a potential warning signal of unbalanced mortalities

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    Adult sex ratios (ASRs) have proved to correlate with population trends, which make them potential useful indicators of a species’ population trajectory and conservation status. We analysed ASRs and proportion of juveniles in flocks of an endangered steppe bird, the Little Bustard Tetrax tetrax, using surveys made during the non-breeding period in seven areas within its Western European range (one in Portugal, four in Spain, and two in France). We found overall male-biased ASRs, as all the seven surveyed areas showed a male-biased ASR mean value. Five areas were below the threshold median value (female sex ratio = 0.4) considered to be consistent with an increased probability of extinction, according to earlier population viability analyses for the species. We also found a significant positive correlation between female ratio and the proportion of young individuals in the non-breeding flocks surveyed. Our results (strongly male-biased ASRs) support the hypothesis that the viability of Little Bustard populations in Western Europe is threatened by an excess of female mortality, something that should be quantified in the future, and emphasise the value of monitoring sex ratio as a population viability indicator in species where monitoring survival is difficult to achieve.This paper is a contribution to the REMEDINAL 3 (S2013/MAE-2719) network which funded a post-doc contract for ESD. It also contributes to the Excellence Network REMEDINAL 3CM (S2013/ MAE2719), supported by Comunidad de Madrid. We thank all the field workers that collaborated in this study. Thanks to Ricardo Montero from Extremadura Birding who provided us with a Little Bustard winter flock video record. We are grateful to Julia Gómez-Catasús for her help with the bootstrapping analysis. This study was carried out with no funds from the Spanish Ministry of Science and Innovation

    Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

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    BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

    Genome-wide association identifies nine common variants associated with fasting proinsulin levels and provides new insights into the pathophysiology of type 2 diabetes.

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    OBJECTIVE: Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired β-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS: We have conducted a meta-analysis of genome-wide association tests of ∼2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS: Nine SNPs at eight loci were associated with proinsulin levels (P < 5 × 10(-8)). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 × 10(-4)), improved β-cell function (P = 1.1 × 10(-5)), and lower risk of T2D (odds ratio 0.88; P = 7.8 × 10(-6)). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS: We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis

    The protocol of the Oslo Study of Clonidine in Elderly Patients with Delirium; LUCID:a randomised placebo-controlled trial

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    Background Delirium affects 15% of hospitalised patients and is linked with poor outcomes, yet few pharmacological treatment options exist. One hypothesis is that delirium may in part result from exaggerated and/or prolonged stress responses. Dexmedetomidine, a parenterally-administered alpha2-adrenergic receptor agonist which attenuates sympathetic nervous system activity, shows promise as treatment in ICU delirium. Clonidine exhibits similar pharmacodynamic properties and can be administered orally. We therefore wish to explore possible effects of clonidine upon the duration and severity of delirium in general medical inpatients. Methods/Design The Oslo Study of Clonidine in Elderly Patients with Delirium (LUCID) is a randomised, placebo-controlled, double-blinded, parallel group study with 4-month prospective follow-up. We will recruit 100 older medical inpatients with delirium or subsyndromal delirium in the acute geriatric ward. Participants will be randomised to oral clonidine or placebo until delirium free for 2 days (Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria), or after a maximum of 7 days treatment. Assessment of haemodynamics (blood pressure, heart rate and electrocardiogram) and delirium will be performed daily until discharge or a maximum of 7 days after end of treatment. The primary endpoint is the trajectory of delirium over time (measured by Memorial Delirium Assessment Scale). Secondary endpoints include the duration of delirium, use of rescue medication for delirium, pharmacokinetics and pharmacodynamics of clonidine, cognitive function after 4 months, length of hospital stay and need for institutionalisation. Discussion LUCID will explore the efficacy and safety of clonidine for delirium in older medical inpatients. Trial registration ClinicalTrials.gov NCT01956604 . EudraCT Number: 2013-000815-2
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