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1.
Br J Dermatol ; 182(5): 1148-1157, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-31520533

RESUMEN

BACKGROUND: Guidelines for follow-up of patients with melanoma are based on limited evidence. OBJECTIVES: To guide skin surveillance, we developed a risk prediction model for subsequent primary melanomas, using demographic, phenotypical, histopathological, sun exposure and genomic risk factors. METHODS: Using Cox regression frailty models, we analysed data for 2613 primary melanomas from 1266 patients recruited to the population-based Genes, Environment and Melanoma study in New South Wales, Australia, with a median of 14 years' follow-up via the cancer registry. Discrimination and calibration were assessed. RESULTS: The median time to diagnosis of a subsequent primary melanoma decreased with each new primary melanoma. The final model included 12 risk factors. Harrell's C-statistic was 0·73 [95% confidence interval (CI) 0·68-0·77], 0·65 (95% CI 0·62-0·68) and 0·65 (95% CI 0·61-0·69) for predicting second, third and fourth primary melanomas, respectively. The risk of a subsequent primary melanoma was 4·75 times higher (95% CI 3·87-5·82) for the highest vs. the lowest quintile of the risk score. The mean absolute risk of a subsequent primary melanoma within 5 years was 8·0 ± SD 4.1% after the first primary melanoma, and 46·8 ± 15·0% after the second, but varied substantially by risk score. CONCLUSIONS: The risk of developing a subsequent primary melanoma varies considerably between individuals and is particularly high for those with two or more primary melanomas. The risk prediction model and its associated nomograms enable estimation of the absolute risk of subsequent primary melanoma, on the basis of on an individual's risk factors, and can be used to tailor surveillance intensity, communicate risk and provide patient education. What's already known about this topic? Current guidelines for the frequency and length of follow-up to detect new primary melanomas in patients with one or more previous primary melanomas are based on limited evidence. People with one or more primary melanomas have, on average, a higher risk of developing another primary invasive melanoma, compared with the general population, but an accurate way of estimating individual risk is needed. What does this study add? We provide a comprehensive risk prediction model for subsequent primary melanomas, using data from 1266 participants with melanoma (2613 primary melanomas), over a median 14 years' follow-up. The model includes 12 risk factors comprising demographic, phenotypical, histopathological and genomic factors, and sun exposure. It enables estimation of the absolute risk of subsequent primary melanomas, and can be used to tailor surveillance intensity, communicate individual risk and provide patient education.


Asunto(s)
Melanoma , Neoplasias Cutáneas , Australia , Estudios de Cohortes , Humanos , Melanoma/epidemiología , Melanoma/etiología , Nueva Gales del Sur/epidemiología , Factores de Riesgo , Neoplasias Cutáneas/epidemiología
2.
Nature ; 512(7513): 171-3, 2014 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-25079321

RESUMEN

The solar neighbourhood is the closest and most easily studied sample of the Galactic interstellar medium, an understanding of which is essential for models of star formation and galaxy evolution. Observations of an unexpectedly intense diffuse flux of easily absorbed 1/4-kiloelectronvolt X-rays, coupled with the discovery that interstellar space within about a hundred parsecs of the Sun is almost completely devoid of cool absorbing gas, led to a picture of a 'local cavity' filled with X-ray-emitting hot gas, dubbed the local hot bubble. This model was recently challenged by suggestions that the emission could instead be readily produced within the Solar System by heavy solar-wind ions exchanging electrons with neutral H and He in interplanetary space, potentially removing the major piece of evidence for the local existence of million-degree gas within the Galactic disk. Here we report observations showing that the total solar-wind charge-exchange contribution is approximately 40 per cent of the 1/4-keV flux in the Galactic plane. The fact that the measured flux is not dominated by charge exchange supports the notion of a million-degree hot bubble extending about a hundred parsecs from the Sun.

3.
Conserv Biol ; 33(3): 697-708, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30615823

RESUMEN

We developed a method to estimate population abundance from simultaneous counts of unmarked individuals over multiple sites. We considered that at each sampling occasion, individuals in a population could be detected at 1 of the survey sites or remain undetected and used either multinomial or binomial simultaneous-count models to estimate abundance, the latter being equivalent to an N-mixture model with one site. We tested model performance with simulations over a range of detection probabilities, population sizes, growth rates, number of years, sampling occasions, and sites. We then applied our method to 3 critically endangered vulture species in Cambodia to demonstrate the real-world applicability of the model and to provide the first abundance estimates for these species in Cambodia. Our new approach works best when existing methods are expected to perform poorly (i.e., few sites and large variation in abundance among sites) and if individuals may move among sites between sampling occasions. The approach performed better when there were >8 sampling occasions and net probability of detection was high (>0.5). We believe our approach will be useful in particular for simultaneous surveys at aggregation sites, such as roosts. The method complements existing approaches for estimating abundance of unmarked individuals and is the first method designed specifically for simultaneous counts.


Modelos de Conteo Simultáneo para Estimar la Abundancia a partir de Conteos de Individuos No Marcados con Detección Imperfecta Resumen Desarrollamos un método para estimar la abundancia poblacional a partir de conteos simultáneos de individuos sin marcaje en múltiples sitios. Consideramos que en cada ocasión de muestreo los individuos de una población podrían ser detectados en uno de los sitios de censos o podrían permanecer sin ser detectados y usamos modelos de conteo simultáneo multinomial o binomial para estimar la abundancia, con el binomial como equivalente a un modelo de mezcla N con un solo sitio. Probamos el desempeño del modelo con simulaciones en un rango de probabilidades de detección, tamaños poblacionales, tasas de crecimiento, número de años, ocasiones de muestreo, y sitios. Después aplicamos nuestro método a tres especies de buitre que se encuentran en peligro crítico en Camboya para demostrar cuán aplicable es el modelo en el mundo real y para proporcionar las primeras estimaciones de abundancia para estas especies en Camboya. Nuestra nueva estrategia trabaja de mejor manera cuando se espera que los modelos existentes tengan un desempeño pobre (es decir, pocos sitios y una gran variación en la abundancia entre sitios) y si los individuos podrían moverse de un sitio a otro entre cada ocasión de muestreo. La estrategia tuvo un mejor desempeñó cuando hubo >8 ocasiones de muestreo y la probabilidad neta de detección fue alta (>0.5). Creemos que nuestra estrategia será especialmente útil para censos simultáneos en sitios de agregación, como los nidos. El método complementa las estrategias existentes para estimar la abundancia de individuos sin marcaje y es el primer método diseñado específicamente para conteos simultáneos.


Asunto(s)
Aves , Conservación de los Recursos Naturales , Animales , Cambodia , Modelos Estadísticos , Densidad de Población , Probabilidad
4.
Br J Dermatol ; 179(3): 590-598, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29570779

RESUMEN

BACKGROUND: The management of histologically dysplastic naevi (HDN) with re-excision vs. observation remains controversial because of lack of evidence about associated melanoma outcomes. OBJECTIVES: To assess published data on the development of biopsy-site primary cutaneous melanoma among biopsy-proven HDN managed with either re-excision or observation. METHODS: A systematic review of all published data: a total of 5293 records were screened, 18 articles were assessed in full text and 12 studies met inclusion criteria. No controlled trials were identified. RESULTS: Most studies (11 of 12, 92%) were retrospective chart reviews, and one was both a cross-sectional and cohort study. Many studies (nine of 12, 75%) had no head-to-head comparison groups and either only reported HDN that were re-excised or observed. A total of 2673 (1535 observed vs. 1138 re-excised) HDN of various grades were included. Follow-up varied between 2 weeks and 30 years. Nine studies reported that no melanomas developed. Eleven biopsy-site melanomas developed across three of the studies, six among observed lesions (0·39%) and five among re-excised lesions (0·44%). CONCLUSIONS: Based upon the available evidence the rates of biopsy-site primary melanoma were similarly low among observed lesions and re-excised lesions. This suggests that HDNs can be observed with minimal adverse melanoma-associated outcomes. However, all included articles were of low quality and further prospective trials could better guide clinical decision making.


Asunto(s)
Procedimientos Quirúrgicos Dermatologicos/métodos , Síndrome del Nevo Displásico/terapia , Melanoma/prevención & control , Neoplasias Cutáneas/terapia , Espera Vigilante , Biopsia , Toma de Decisiones Clínicas , Síndrome del Nevo Displásico/diagnóstico , Síndrome del Nevo Displásico/patología , Humanos , Melanoma/diagnóstico , Melanoma/patología , Retratamiento/métodos , Piel/patología , Neoplasias Cutáneas/diagnóstico , Neoplasias Cutáneas/patología
7.
Space Sci Rev ; 220(4): 37, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38756703

RESUMEN

The Lunar Environment heliospheric X-ray Imager (LEXI) is a wide field-of-view soft X-ray telescope developed to study solar wind-magnetosphere coupling. LEXI is part of the Blue Ghost 1 mission comprised of 10 payloads to be deployed on the lunar surface. LEXI monitors the dayside magnetopause position and shape as a function of time by observing soft X-rays (0.1-2 keV) emitted from solar wind charge-exchange between exospheric neutrals and high charge-state solar wind plasma in the dayside magnetosheath. Measurements of the shape and position of the magnetopause are used to test temporal models of meso- and macro-scale magnetic reconnection. To image the boundary, LEXI employs lobster-eye optics to focus X-rays to a microchannel plate detector with a 9.1×∘9.1∘ field of view.

9.
Scand J Med Sci Sports ; 21(6): e341-50, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21518010

RESUMEN

The purpose of this study was to examine the effects of exercising at different intensities over 7 weeks on components of physical fitness and CVD risk factors. Forty-seven boys and 10 girls, (16.4±0.7 years of age) were divided into a moderate, high intensity, or a control group. All participants had indices of obesity and blood pressure recorded in addition to four physical performance measures pre- and post-intervention. In addition, the intervention groups repeated the physical performance measures at the 4th week phase of the intervention. Following the intervention, significant improvements (P<0.05) in the high-intensity group were found in the 20 MSFT, agility, CMJ and 10 m sprint post-intervention. Participants in the moderate intensity group displayed significant improvements (P<0.05) in both the CMJ and 20 MSFT post-intervention. Body fat % significantly improved (P<0.01) in the moderate group only post-intervention. Interestingly, Systolic blood pressure significantly improved post-intervention (112±10 vs 106±11 mmHg) (P=0.017) in the high intensity group. In conclusion, high-intensity exercise over 7 weeks is a very time efficient means of improving important components of physical fitness in adolescents.


Asunto(s)
Ejercicio Físico/fisiología , Aptitud Física/fisiología , Adolescente , Enfermedades Cardiovasculares/prevención & control , Estudios de Cohortes , Femenino , Humanos , Masculino , Obesidad/prevención & control , Escocia , Encuestas y Cuestionarios
10.
Ann Hum Biol ; 38(1): 22-7, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20450386

RESUMEN

BACKGROUND: This study examines CVD risk factors trends in Welsh adolescents between 2002 and 2007. PARTICIPANTS AND METHODS: CVD risk factor data was examined from two cross-sectional studies. The first study (73 participants; aged 12.9 ± 0.3 years) was completed in 2002. The second study (90 participants; aged 12.9 ± 0.4 years) was conducted in 2007. Measurements included body mass index (BMI), waist circumference (WC), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, fibrinogen (Fg) and high-sensitivity C-reactive protein (hs-CRP). RESULTS: In boys, mean BMI and WC were lower in 2007, although not significantly (p ≥ 0.05). In 2007, there were improvements in mean lipid, Fg and hs-CRP concentrations in both sexes (p < 0.05). In 2002, 42.8% of boys and 34.2% of girls were overweight or obese; in 2007, this was 23.7% and 28.9% for boys and girls, respectively. More adolescents in 2002 exceeded the recommended levels for lipids, Fg and hs-CRP. CONCLUSION: This is the only study to examine CVD risk factor trends in Welsh adolescents. Although overweight continues to be widespread in 12-13 year olds, this study did not identify significant mean changes in overweight and obesity between 2002 and 2007. Overall, the data presented a positive trend in lipid profile and inflammatory factors.


Asunto(s)
Índice de Masa Corporal , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/etiología , Encuestas Epidemiológicas , Circunferencia de la Cintura , Adolescente , Presión Sanguínea , Proteína C-Reactiva/análisis , Enfermedades Cardiovasculares/prevención & control , Niño , Colesterol/sangre , HDL-Colesterol/sangre , LDL-Colesterol/sangre , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Estilo de Vida , Estudios Longitudinales , Masculino , Obesidad , Factores de Riesgo , Triglicéridos/sangre , Gales/epidemiología
11.
Ecol Evol ; 11(9): 4205-4217, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33976804

RESUMEN

Dry deciduous dipterocarp forests (DDF) cover about 15%-20% of Southeast Asia and are the most threatened forest type in the region. The jungle cat (Felis chaus) is a DDF specialist that occurs only in small isolated populations in Southeast Asia. Despite being one of the rarest felids in the region, almost nothing is known about its ecology. We investigated the ecology of jungle cats and their resource partitioning with the more common leopard cats (Prionailurus bengalensis) in a DDF-dominated landscape in Srepok Wildlife Sanctuary, Cambodia. We used camera-trap data collected from 2009 to 2019 and DNA-confirmed scats to determine the temporal, dietary and spatial overlap between jungle cats and leopard cats. The diet of jungle cats was relatively diverse and consisted of murids (56% biomass consumed), sciurids (15%), hares (Lepus peguensis; 12%), birds (8%), and reptiles (8%), whereas leopard cats had a narrower niche breadth and a diet dominated by smaller prey, primarily murids (73%). Nonetheless, dietary overlap was high because both felid species consumed predominantly small rodents. Both species were primarily nocturnal and had high temporal overlap. Two-species occupancy modelling suggested jungle cats were restricted to DDF and had low occupancy, whereas leopard cats had higher occupancy and were habitat generalists. Our study confirmed that jungle cats are DDF specialists that likely persist in low numbers due to the harsh conditions of the dry season in this habitat, including annual fires and substantial decreases in small vertebrate prey. The lower occupancy and more diverse diet of jungle cats, together with the broader habitat use of leopard cats, likely facilitated the coexistence of these species. The low occupancy of jungle cats in DDF suggests that protection of large areas of DDF will be required for the long-term conservation of this rare felid in Southeast Asia.

12.
J Sports Sci ; 28(12): 1361-8, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20853205

RESUMEN

The aim of this study was to examine the effect of supra-maximal exercise on circulating concentrations of salivary testosterone, salivary cortisol, and salivary immunoglobulin A in female adolescents. Nineteen apparently healthy females aged 15-16 years participated in this study. All participants completed 668 s sprints, interspersed with 30 s recovery intervals on a cycle ergometer. Salivary testosterone, cortisol, and immunoglobulin A samples were taken before and 5 min after exercise. Experimental procedures continued over two mornings, at least 3 h after a light breakfast. Participants refrained from performing any strenuous physical activity for at least 24 h prior to the exercise test. None of the participants were engaged in a structured training programme. The group mean (± s) for peak power output was 562 ± 113.0 W. Female adolescents recruited for this study showed no changes in salivary testosterone, cortisol or immunoglobulin A following repeated bouts of supra-maximal cycling (P > 0.05). To date, there has been a paucity of information concerning adolescents' hormonal and mucosal immune function responses to supra-maximal exercise. Our data provide further guidance with regard to physical activities and sports prescription for female adolescents. Further research, on a larger sample of females, is required to elucidate the physiological significance of these findings.


Asunto(s)
Ciclismo/fisiología , Ejercicio Físico/fisiología , Hidrocortisona/análisis , Inmunoglobulina A Secretora/análisis , Saliva/química , Testosterona/análisis , Adolescente , Prueba de Esfuerzo , Femenino , Humanos , Inmunidad Mucosa , Esfuerzo Físico/fisiología
13.
Conserv Biol ; 23(2): 433-9, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19016820

RESUMEN

Predictive models can help clarify the distribution of poorly known species but should display strong transferability when applied to independent data. Nevertheless, model transferability for threatened tropical species is poorly studied. We built models predicting the incidence of the critically endangered Bengal Florican (Houbaropsis bengalensis) within the Tonle Sap (TLS) floodplain, Cambodia. Separate models were constructed with soil, land-use, and landscape data and species incidence sampled over the entire floodplain (12,000 km(2)) and from the Kompong Thom (KT) province (4000 km(2)). In each case, the probability of Bengal Florican presence within randomly selected 1 x 1 km squares was modeled by binary logistic regression with multimodel inference. We assessed the transferability of the KT model by comparing predictions with observed incidence elsewhere in the floodplain. In terms of standard model-validation statistics, the KT model showed good spatial transferability. Nevertheless, it overpredicted florican presence outside the KT calibration region, classifying 491 km(2) as suitable habitat compared with 237 km(2) predicted as suitable by the TLS model. This resulted from higher species incidence within the calibration region, probably owing to a program of conservation education and enforcement that has reduced persecution there. Because both research and conservation activity frequently focus on areas with higher density, such effects could be widespread, reducing transferability of predictive distribution models.


Asunto(s)
Aves/fisiología , Conservación de los Recursos Naturales/métodos , Modelos Biológicos , Animales , Cambodia , Demografía , Ecosistema
14.
Commun Biol ; 2: 396, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31701025

RESUMEN

Habitat degradation and hunting have caused the widespread loss of larger vertebrate species (defaunation) from tropical biodiversity hotspots. However, these defaunation drivers impact vertebrate biodiversity in different ways and, therefore, require different conservation interventions. We conducted landscape-scale camera-trap surveys across six study sites in Southeast Asia to assess how moderate degradation and intensive, indiscriminate hunting differentially impact tropical terrestrial mammals and birds. We found that functional extinction rates were higher in hunted compared to degraded sites. Species found in both sites had lower occupancies in the hunted sites. Canopy closure was the main predictor of occurrence in the degraded sites, while village density primarily influenced occurrence in the hunted sites. Our findings suggest that intensive, indiscriminate hunting may be a more immediate threat than moderate habitat degradation for tropical faunal communities, and that conservation stakeholders should focus as much on overhunting as on habitat conservation to address the defaunation crisis.


Asunto(s)
Biodiversidad , Clima Tropical , Animales , Asia Sudoriental , Teorema de Bayes , Aves , Conservación de los Recursos Naturales/estadística & datos numéricos , Conservación de los Recursos Naturales/tendencias , Ecosistema , Extinción Biológica , Mamíferos , Dinámica Poblacional/estadística & datos numéricos , Dinámica Poblacional/tendencias , Especificidad de la Especie
16.
Scand J Med Sci Sports ; 18(5): 543-56, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18627553

RESUMEN

Cardiovascular disease (CVD) remains one of the leading causes of morbidity and mortality in developed countries. Over the past decade there has been much focus on the role of inflammation in the pathogenesis of atherosclerosis; to this end, there is increasing research on inflammatory factors such as C-reactive protein (CRP), interleukin-6 (IL-6), and fibrinogen (Fg). There is compelling evidence that physical activity (PA) and physical fitness (PF) protect against chronic disease. More recently, research has shown that exercise reduces CRP, IL-6, and Fg concentration in adults, and that this is often independent of adiposity. Although there are some data to suggest that this is similarly true for young people, there is inconsistency in the literature. The following review aims to illustrate what is known about the effects of PA and PF on inflammatory factors in young people aged 5-18 years.


Asunto(s)
Ejercicio Físico/fisiología , Inflamación/fisiopatología , Actividad Motora , Aptitud Física , Adolescente , Índice de Masa Corporal , Proteína C-Reactiva/análisis , Proteína C-Reactiva/fisiología , Enfermedades Cardiovasculares/fisiopatología , Niño , Preescolar , Enfermedad Crónica , Metabolismo Energético , Femenino , Fibrinógeno/análisis , Humanos , Inflamación/metabolismo , Interleucina-6/análisis , Masculino , Actividad Motora/fisiología , Obesidad/metabolismo , Consumo de Oxígeno/fisiología , Aptitud Física/fisiología , Adulto Joven
17.
Br J Sports Med ; 42(5): 357-60, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18178678

RESUMEN

OBJECTIVE: To investigate the relation between C-reactive protein (CRP), adiposity, physical activity, aerobic fitness and habitual diet in a cohort of schoolchildren. METHODS: A cross-sectional study of 164 schoolchildren aged 12-13 years was conducted in two schools. Adiposity was estimated using body mass index and waist circumference. Blood samples were taken after an overnight fast and measured for CRP. Aerobic fitness and habitual physical activity were assessed using the 20 metres multistage fitness test, and a seven-day recall, respectively. A seven-day food diary provided measures of dietary intake. RESULTS: To improve the distribution of this variable, CRP levels were logarithmically transformed in all analyses. There was no significant difference in mean CRP concentration between boys (1.07 (1.33) mg/l) and girls (1.24 (1.87) mg/l) (p> or =0.05). Compared to girls, boys reported significantly higher (i) aerobic fitness 59.2 (20.3) shuttles vs 42.9 (15.3) shuttles, (ii) vigorous activity levels per week 92 (123) minutes vs 11.2 (34.6) minutes and (iii) waist circumference 69.8 (1.1) cm vs 65.2 (0.9) cm (p< or =0.05). Among boys and girls, adiposity was significantly associated with log transformed CRP (p< or =0.05). CRP was not significantly related to any other variable. CONCLUSION: Elevated CRP was evident in this cohort; however, whether high CRP levels during childhood and adolescence leads to an increased risk of CVD in later life has not been determined. Adiposity was related to CRP concentration, suggesting that reducing adiposity may be effective in lowering CRP and preventing future cardiovascular events.


Asunto(s)
Adiposidad/fisiología , Proteína C-Reactiva/metabolismo , Ejercicio Físico/fisiología , Conducta Alimentaria/fisiología , Aptitud Física/fisiología , Adolescente , Composición Corporal/fisiología , Índice de Masa Corporal , Pesos y Medidas Corporales , Enfermedades Cardiovasculares/prevención & control , Niño , Estudios de Cohortes , Estudios Transversales , Femenino , Humanos , Masculino , Factores de Riesgo
18.
Res Sports Med ; 16(4): 233-43, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19089745

RESUMEN

The aim of this unique study was to consider the relationship between folate and vitamin B(12) on homocyst(e)ine (Hcy) concentration in an apparently healthy cohort of Welsh young people. A cohort of 179, 12-13 year olds (88 boys and 91 girls) were measured for Hcy, folate, vitamin B(12), adiposity, and dietary habits. Boys had significantly higher waist circumference and folate concentration than girls. Folate was negatively associated with Hcy in both sexes, whereas vitamin B(12) was negatively associated with Hcy in boys only. Adiposity was not associated with Hcy. Folate was an independent predictor of Hcy in both sexes, whilst vitamin B(12) was an independent determinant of Hcy in boys only. Familial history of cardiovascular disease (CVD) risk factors was identified in 69% of the children with elevated Hcy (> or = 8.5 mumol.L(-1)). Young people might be encouraged to increase their folate intake through diet, particularly by increasing their consumption of leafy vegetables and fruit. Further research is necessary to determine the exact contribution of genetics and diet on Hcy levels in young people, and whether Hcy levels during childhood and adolescence might influence future CVD risk.


Asunto(s)
Ácido Fólico/sangre , Homocisteína/sangre , Vitamina B 12/sangre , Adolescente , Factores de Edad , Índice de Masa Corporal , Niño , Estudios de Cohortes , Dieta , Femenino , Humanos , Masculino , Valores de Referencia , Factores Sexuales , Circunferencia de la Cintura , Gales
19.
Mol Ecol Resour ; 18(6): 1282-1298, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29877042

RESUMEN

The use of environmental DNA (eDNA) has become an applicable noninvasive tool with which to obtain information about biodiversity. A subdiscipline of eDNA is iDNA (invertebrate-derived DNA), where genetic material ingested by invertebrates is used to characterize the biodiversity of the species that served as hosts. While promising, these techniques are still in their infancy, as they have only been explored on limited numbers of samples from only a single or a few different locations. In this study, we investigate the suitability of iDNA extracted from more than 3,000 haematophagous terrestrial leeches as a tool for detecting a wide range of terrestrial vertebrates across five different geographical regions on three different continents. These regions cover almost the full geographical range of haematophagous terrestrial leeches, thus representing all parts of the world where this method might apply. We identify host taxa through metabarcoding coupled with high-throughput sequencing on Illumina and IonTorrent sequencing platforms to decrease economic costs and workload and thereby make the approach attractive for practitioners in conservation management. We identified hosts in four different taxonomic vertebrate classes: mammals, birds, reptiles and amphibians, belonging to at least 42 different taxonomic families. We find that vertebrate blood ingested by haematophagous terrestrial leeches throughout their distribution is a viable source of DNA with which to examine a wide range of vertebrates. Thus, this study provides encouraging support for the potential of haematophagous terrestrial leeches as a tool for detecting and monitoring terrestrial vertebrate biodiversity.


Asunto(s)
Análisis Químico de la Sangre/métodos , Código de Barras del ADN Taxonómico/métodos , Monitoreo del Ambiente/métodos , Sanguijuelas/crecimiento & desarrollo , Metagenómica/métodos , Anfibios/parasitología , Animales , Aves/parasitología , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Mamíferos/parasitología , Reptiles/parasitología
20.
PLoS One ; 13(11): e0207114, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30408090

RESUMEN

With less than 3200 wild tigers in 2010, the heads of 13 tiger-range countries committed to doubling the global population of wild tigers by 2022. This goal represents the highest level of ambition and commitment required to turn the tide for tigers in the wild. Yet, ensuring efficient and targeted implementation of conservation actions alongside systematic monitoring of progress towards this goal requires that we set site-specific recovery targets and timelines that are ecologically realistic. In this study, we assess the recovery potential of 18 sites identified under WWF's Tigers Alive Initiative. We delineated recovery systems comprising a source, recovery site, and support region, which need to be managed synergistically to meet these targets. By using the best available data on tiger and prey numbers, and adapting existing species recovery frameworks, we show that these sites, which currently support 165 (118-277) tigers, have the potential to harbour 585 (454-739) individuals. This would constitute a 15% increase in the global population and represent over a three-fold increase within these specific sites, on an average. However, it may not be realistic to achieve this target by 2022, since tiger recovery in 15 of these 18 sites is contingent on the initial recovery of prey populations, which is a slow process. We conclude that while sustained conservation efforts can yield significant recoveries, it is critical that we commit our resources to achieving the biologically realistic targets for these sites even if the timelines are extended.


Asunto(s)
Especies en Peligro de Extinción , Tigres , Animales , Asia , Objetivos , Densidad de Población , Conducta Predatoria , Factores de Tiempo
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