Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Health Expect ; 27(2): e14010, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38450803

RESUMEN

OBJECTIVE: Decisional conflict is used increasingly as an outcome measure in advance care planning (ACP) studies. When the Decisional Conflict Scale (DCS) is used in anticipatory decision-making contexts, the scale is typically tethered to hypothetical scenarios. This study reports preliminary validation data for hypothetical scenarios relating to life-sustaining treatments and care utilisation to inform their broader use in ACP studies. METHODS: Three hypothetical scenarios were developed by a panel of multidisciplinary researchers, clinicians and community representatives. A convenience sample of 262 older adults were surveyed. Analyses investigated comprehensibility, missing data properties, sample norms, structural, convergent and discriminant validity. RESULTS: Response characteristics suggested that two of the scenarios had adequate comprehensibility and response spread. Missing response rates were unrelated to demographic characteristics. Predicted associations between DCS scores and anxiety (r's = .31-.37, p < .001), and ACP engagement (r's = -.41 to -.37, p < .001) indicated convergent validity. CONCLUSION: A substantial proportion of older adults reported clinically significant levels of decisional conflict when responding to a range of hypothetical scenarios about care or treatment. Two scenarios showed acceptable comprehensibility and response characteristics. A third scenario may be suitable following further refinement. PATIENT OR PUBLIC CONTRIBUTION: The scenarios tested here were designed in collaboration with a community representative and were further piloted with two groups of community members with relevant lived experiences; four people with life-limiting conditions and five current or former care partners.


Asunto(s)
Planificación Anticipada de Atención , Humanos , Anciano , Ansiedad , Proyectos de Investigación , Investigadores
2.
Mol Biol Evol ; 33(4): 995-1007, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26739881

RESUMEN

Mitochondria are critical for life, yet their underlying evolutionary biology is poorly understood. In particular, little is known about interaction between two levels of evolution: between individuals and within individuals (competition between cells, mitochondria or mitochondrial DNA molecules). Rapid evolution is suspected to occur frequently in mitochondrial DNA, whose maternal inheritance predisposes advantageous mutations to sweep rapidly though populations. Rapid evolution is also predicted in response to changed selection regimes after species invasion or removal of pathogens or competitors. Here, using empirical and simulated data from a model invasive bird species, we provide the first demonstration of rapid selection on the mitochondrial genome within individuals in the wild. Further, we show differences in mitochondrial DNA copy number associated with competing genetic variants, which may provide a mechanism for selection. We provide evidence for three rarely documented phenomena: selection associated with mitochondrial DNA abundance, selection on the mitochondrial control region, and contemporary selection during invasion.


Asunto(s)
ADN Mitocondrial/genética , Evolución Molecular , Genoma Mitocondrial/genética , Selección Genética/genética , Animales , Aves/genética , Variación Genética , Genotipo , Especies Introducidas , Mitocondrias/genética , Mutación
3.
Mol Ecol ; 26(17): 4551-4561, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28667769

RESUMEN

Deciphering the genes involved in disease resistance is essential if we are to understand host-pathogen coevolutionary processes. The rabbit haemorrhagic disease virus (RHDV) was imported into Australia in 1995 as a biocontrol agent to manage one of the most successful and devastating invasive species, the European rabbit (Oryctolagus cuniculus). During the first outbreaks of the disease, RHDV caused mortality rates of up to 97%. Recently, however, increased genetic resistance to RHDV has been reported. Here, we have aimed to identify genomic differences between rabbits that survived a natural infection with RHDV and those that died in the field using a genomewide next-generation sequencing (NGS) approach. We detected 72 SNPs corresponding to 133 genes associated with survival of a RHD infection. Most of the identified genes have known functions in virus infections and replication, immune responses or apoptosis, or have previously been found to be regulated during RHD. Some of the genes identified in experimental studies, however, did not seem to play a role under natural selection regimes, highlighting the importance of field studies to complement the genomic background of wildlife diseases. Our study provides a set of candidate markers as a tool for the future scanning of wild rabbits for their resistance to RHDV. This is important both for wild rabbit populations in southern Europe where RHD is regarded as a serious problem decimating the prey of endangered predator species and for assessing the success of currently planned RHDV variant biocontrol releases in Australia.


Asunto(s)
Infecciones por Caliciviridae/genética , Infecciones por Caliciviridae/veterinaria , Resistencia a la Enfermedad/genética , Conejos/genética , Animales , Animales Salvajes/genética , Animales Salvajes/virología , Australia , Agentes de Control Biológico , Virus de la Enfermedad Hemorrágica del Conejo , Conejos/virología
4.
Mol Ecol ; 23(2): 408-20, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24251353

RESUMEN

Rabbit Haemorrhagic Disease Virus (RHDV) was introduced into Australia in 1995 as a biological control agent against the wild European rabbit (Oryctolagus cuniculus). We evaluated its evolution over a 16-year period (1995-2011) by examining 50 isolates collected throughout Australia, as well as the original inoculum strains. Phylogenetic analysis of capsid protein VP60 sequences of the Australian isolates, compared with those sampled globally, revealed that they form a monophyletic group with the inoculum strains (CAPM V-351 and RHDV351INOC). Strikingly, despite more than 3000 rereleases of RHDV351INOC since 1995, only a single viral lineage has sustained its transmission in the long-term, indicative of a major competitive advantage. In addition, we find evidence for widespread viral gene flow, in which multiple lineages entered individual geographic locations, resulting in a marked turnover of viral lineages with time, as well as a continual increase in viral genetic diversity. The rate of RHDV evolution recorded in Australia -4.0 (3.3-4.7) × 10(-3) nucleotide substitutions per site per year - was higher than previously observed in RHDV, and evidence for adaptive evolution was obtained at two VP60 residues. Finally, more intensive study of a single rabbit population (Turretfield) in South Australia provided no evidence for viral persistence between outbreaks, with genetic diversity instead generated by continual strain importation.


Asunto(s)
Infecciones por Caliciviridae/virología , Evolución Molecular , Virus de la Enfermedad Hemorrágica del Conejo/genética , Proteínas Estructurales Virales/genética , Animales , Australia , Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/veterinaria , Flujo Génico , Marcadores Genéticos , Variación Genética , Epidemiología Molecular , Datos de Secuencia Molecular , Filogenia , ARN Viral/genética , Conejos , Análisis de Secuencia de ADN
5.
BMC Pulm Med ; 13: 43, 2013 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-23837867

RESUMEN

BACKGROUND: Exhaled breath volatile organic compound (VOC) analysis for airway disease monitoring is promising. However, contrary to nitric oxide the method for exhaled breath collection has not yet been standardized and the effects of expiratory flow and breath-hold have not been sufficiently studied. These manoeuvres may also reveal the origin of exhaled compounds. METHODS: 15 healthy volunteers (34 ± 7 years) participated in the study. Subjects inhaled through their nose and exhaled immediately at two different flows (5 L/min and 10 L/min) into methylated polyethylene bags. In addition, the effect of a 20 s breath-hold following inhalation to total lung capacity was studied. The samples were analyzed for ethanol and acetone levels immediately using proton-transfer-reaction mass-spectrometer (PTR-MS, Logan Research, UK). RESULTS: Ethanol levels were negatively affected by expiratory flow rate (232.70 ± 33.50 ppb vs. 202.30 ± 27.28 ppb at 5 L/min and 10 L/min, respectively, p < 0.05), but remained unchanged following the breath hold (242.50 ± 34.53 vs. 237.90 ± 35.86 ppb, without and with breath hold, respectively, p = 0.11). On the contrary, acetone levels were increased following breath hold (1.50 ± 0.18 ppm) compared to the baseline levels (1.38 ± 0.15 ppm), but were not affected by expiratory flow (1.40 ± 0.14 ppm vs. 1.49 ± 0.14 ppm, 5 L/min vs. 10 L/min, respectively, p = 0.14). The diet had no significant effects on the gasses levels which showed good inter and intra session reproducibility. CONCLUSIONS: Exhalation parameters such as expiratory flow and breath-hold may affect VOC levels significantly; therefore standardisation of exhaled VOC measurements is mandatory. Our preliminary results suggest a different origin in the respiratory tract for these two gasses.


Asunto(s)
Pruebas Respiratorias/métodos , Espiración/fisiología , Espectrometría de Masas/métodos , Espectrometría de Masas/normas , Compuestos Orgánicos Volátiles/metabolismo , Acetona/metabolismo , Adulto , Etanol/metabolismo , Femenino , Humanos , Masculino , Ápice del Flujo Espiratorio/fisiología , Reproducibilidad de los Resultados , Sistema Respiratorio/metabolismo , Factores de Tiempo , Capacidad Pulmonar Total/fisiología
6.
J Alzheimers Dis ; 91(3): 933-960, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36530085

RESUMEN

BACKGROUND: Historically, research questions have been posed by the pharmaceutical industry or researchers, with little involvement of consumers and healthcare professionals. OBJECTIVE: To determine what questions about medicine use are important to people living with dementia and their care team and whether they have been previously answered by research. METHODS: The James Lind Alliance Priority Setting Partnership process was followed. A national Australian qualitative survey on medicine use in people living with dementia was conducted with consumers (people living with dementia and their carers including family, and friends) and healthcare professionals. Survey findings were supplemented with key informant interviews and relevant published documents (identified by the research team). Conventional content analysis was used to generate summary questions. Finally, evidence checking was conducted to determine if the summary questions were 'unanswered'. RESULTS: A total of 545 questions were submitted by 228 survey participants (151 consumers and 77 healthcare professionals). Eight interviews were conducted with key informants and four relevant published documents were identified and reviewed. Overall, analysis resulted in 68 research questions, grouped into 13 themes. Themes with the greatest number of questions were related to co-morbidities, adverse drug reactions, treatment of dementia, and polypharmacy. Evidence checking resulted in 67 unanswered questions. CONCLUSION: A wide variety of unanswered research questions were identified. Addressing unanswered research questions identified by consumers and healthcare professionals through this process will ensure that areas of priority are targeted in future research to achieve optimal health outcomes through quality use of medicines.


Asunto(s)
Investigación Biomédica , Demencia , Humanos , Prioridades en Salud , Australia , Personal de Salud , Cuidadores , Demencia/tratamiento farmacológico
7.
Mol Ecol ; 21(5): 1038-41, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22292800

RESUMEN

Rabbit haemorrhagic disease virus (RHDV) is a highly virulent lagovirus endemic in Europe and Australasian populations of the European rabbit, Oryctolagus cuniculus. It has also caused several unexplained disease outbreaks in domestic European rabbits in North America. Non-pathogenic spread of RHDV leading to persistent infection which later reactivated has recently been proposed as the cause of overt disease and death of a pet rabbit in Canada, the first confirmed case of Rabbit haemorrhagic disease in that country. We suggest that there is little evidence to support non-pathogenic spread of virulent RHDV, some evidence that is contradictory, and evidence to support a simpler alternative hypothesis. RHDV can be spread over long distances between sparse rabbit populations by fomites or flying insects. Although highly pathogenic, RHDV can be limited in its spread within rabbit populations, or its presence masked by closely related but non-pathogenic lagoviruses which can provide protection against acute disease. In the absence of any evidence from clinical studies to support reactivation of persistent RHDV infection, the simpler explanation seems more likely to be correct.


Asunto(s)
Infecciones por Caliciviridae/transmisión , Brotes de Enfermedades , Virus de la Enfermedad Hemorrágica del Conejo/patogenicidad , Modelos Biológicos , Animales , Australia/epidemiología , Infecciones por Caliciviridae/epidemiología , Canadá/epidemiología , Europa (Continente)/epidemiología , Virus de la Enfermedad Hemorrágica del Conejo/clasificación , Filogenia , Conejos
8.
Mol Ecol ; 20(11): 2307-17, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21507095

RESUMEN

Mitochondrial DNA (mtDNA) can be a powerful genetic marker for tracing origins and history of invasive populations. Here, we use mtDNA to address questions relevant to the understanding of invasion pathways of common starlings (Sturnus vulgaris) into Western Australia (WA) and discuss the utility of this marker to provide information useful to invasive species management. Mitochondrial sequence data indicate two geographically restricted genetic groups within Australia. Evidence of dispersal from genetically distinct sources outside the sampled range of starlings in Australia suggests increased vigilance by management agencies may be required to prevent further incursions from widely separated localities. Overall, genetic diversity in Australia was lower than in samples from the native range. Within Australia, genetic diversity was lowest in the most recently colonized area in the west, indicating that demographic bottlenecks have occurred in this area. Evidence of restricted dispersal between localities on the edge of the range expansion (ERE) in WA and other Australian sampling localities suggests that localized control within the ERE may be effective in preventing further range expansion. Signatures of spatial and demographic expansion are present in mismatch analyses from sampling localities located at the ERE, but neutrality indices did not support this finding, suggesting that the former may be more sensitive to recent expansion. Additionally, mismatch analyses support the presence of admixture, which is likely to have occurred pre-introduction. We compare our findings with those from a microsatellite study of the same samples and discuss how the mtDNA analyses used here offer valuable and unique insights into the invasion history of introduced species.


Asunto(s)
ADN Mitocondrial/genética , Especies Introducidas , Estorninos/genética , Animales , Secuencia de Bases , Haplotipos/genética , Datos de Secuencia Molecular , Filogenia , Dinámica Poblacional , Australia Occidental
9.
Rev Sci Instrum ; 92(7): 073306, 2021 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-34340440

RESUMEN

A retarding potential energy analyzer was used to obtain temporally resolved ion energy distribution functions (IEDFs) of a flowing laboratory plasma. The plasma of time varying ion energy was generated at 1 and 20 kHz using a commercial gridded ion source and modulated using a wideband power amplifier. Three plasma energy modulation setpoints were tested, and their IEDFs were reconstructed. This method leverages high-speed, low-noise instrumentation to obtain fast collector current measurements at discrete retarding bias levels, recombining them in the time domain using two data fusion techniques. The first method is an empirical transfer function, which determines the linear ratio of complex coefficients in Fourier space. The second method, shadow manifold interpolation, reconstructs the IEDFs point-by-point by comparing input and output datasets in a multi-dimensional phase space. Reconstructed IEDFs from the two methods are presented and compared. The two analysis methods show very good agreement.

10.
Mol Ecol ; 18(8): 1560-73, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19317845

RESUMEN

Invasive species are known to cause environmental and economic damage, requiring management by control agencies worldwide. These species often become well established in new environments long before their detection, resulting in a lack of knowledge regarding their history and dynamics. When new invasions are discovered, information regarding the source and pathway of the invasion, and the degree of connectivity with other populations can greatly benefit management strategies. Here we use invasive common starling (Sturnus vulgaris) populations from Australia to demonstrate that genetic techniques can provide this information to aid management, even when applied to highly vagile species over continental scales. Analysis of data from 11 microsatellites in 662 individuals sampled at 17 localities across their introduced range in Australia revealed four populations. One population consisted of all sampling sites from the expansion front in Western Australia, where control efforts are focused. Despite evidence of genetic exchange over both contemporary and historical timescales, gene flow is low between this population and all three more easterly populations. This suggests that localized control of starlings on the expansion front may be an achievable goal and the long-standing practice of targeting select proximal eastern source populations may be ineffective on its own. However, even with low levels of gene flow, successful control of starlings on the expansion front will require vigilance, and genetic monitoring of this population can provide essential information to managers. The techniques used here are broadly applicable to invasive populations worldwide.


Asunto(s)
Conservación de los Recursos Naturales , Genética de Población , Repeticiones de Microsatélite , Estorninos/genética , Alelos , Animales , Análisis por Conglomerados , Femenino , Flujo Génico , Variación Genética , Modelos Lineales , Masculino , Dinámica Poblacional , Análisis de Secuencia de ADN , Australia Occidental
11.
Vet Rec ; 182(20): 574, 2018 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-29519856

RESUMEN

Lagovirus europaeus GI.2, also commonly known as rabbit haemorrhagic disease virus 2, was first detected at two long-term monitoring sites for European rabbits, Oryctolagus cuniculus, in South Australia, in mid-2016. Numbers of rabbits in the following 12-18 months were reduced to approximately 20 per cent of average numbers in the preceding 10 years. The impact recorded at the two South Australian sites, if widespread in Australia and persistent for several years, is likely to be of enormous economic and environmental benefit.


Asunto(s)
Infecciones por Caliciviridae/veterinaria , Virus de la Enfermedad Hemorrágica del Conejo/aislamiento & purificación , Animales , Australia , Infecciones por Caliciviridae/virología , Virus de la Enfermedad Hemorrágica del Conejo/genética , Dinámica Poblacional , Conejos
12.
J R Soc Interface ; 12(103)2015 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-25566883

RESUMEN

Infectious diseases can exert a strong influence on the dynamics of host populations, but it remains unclear why such disease-mediated control only occurs under particular environmental conditions. We used 16 years of detailed field data on invasive European rabbits (Oryctolagus cuniculus) in Australia, linked to individual-based stochastic models and Bayesian approximations, to test whether (i) mortality associated with rabbit haemorrhagic disease (RHD) is driven primarily by seasonal matches/mismatches between demographic rates and epidemiological dynamics and (ii) delayed infection (arising from insusceptibility and maternal antibodies in juveniles) are important factors in determining disease severity and local population persistence of rabbits. We found that both the timing of reproduction and exposure to viruses drove recurrent seasonal epidemics of RHD. Protection conferred by insusceptibility and maternal antibodies controlled seasonal disease outbreaks by delaying infection; this could have also allowed escape from disease. The persistence of local populations was a stochastic outcome of recovery rates from both RHD and myxomatosis. If susceptibility to RHD is delayed, myxomatosis will have a pronounced effect on population extirpation when the two viruses coexist. This has important implications for wildlife management, because it is likely that such seasonal interplay and disease dynamics has a strong effect on long-term population viability for many species.


Asunto(s)
Infecciones por Caliciviridae/epidemiología , Infecciones por Caliciviridae/inmunología , Virus de la Enfermedad Hemorrágica del Conejo/inmunología , Especies Introducidas , Modelos Inmunológicos , Estaciones del Año , Animales , Australia/epidemiología , Femenino , Masculino , Mixomatosis Infecciosa , Conejos
13.
Evol Appl ; 7(9): 1056-67, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25553067

RESUMEN

In Australia, the rabbit haemorrhagic disease virus (RHDV) has been used since 1996 to reduce numbers of introduced European rabbits (Oryctolagus cuniculus) which have a devastating impact on the native Australian environment. RHDV causes regular, short disease outbreaks, but little is known about how the virus persists and survives between epidemics. We examined the initial spread of RHDV to show that even upon its initial spread, the virus circulated continuously on a regional scale rather than persisting at a local population level and that Australian rabbit populations are highly interconnected by virus-carrying flying vectors. Sequencing data obtained from a single rabbit population showed that the viruses that caused an epidemic each year seldom bore close genetic resemblance to those present in previous years. Together, these data suggest that RHDV survives in the Australian environment through its ability to spread amongst rabbit subpopulations. This is consistent with modelling results that indicated that in a large interconnected rabbit meta-population, RHDV should maintain high virulence, cause short, strong disease outbreaks but show low persistence in any given subpopulation. This new epidemiological framework is important for understanding virus-host co-evolution and future disease management options of pest species to secure Australia's remaining natural biodiversity.

14.
Environ Int ; 51: 141-9, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23220015

RESUMEN

Large-scale international monitoring studies are important to assess emission patterns and environmental distributions of organohalogenated contaminants (OHCs) on a worldwide scale. In this study, the presence of OHCs was investigated on three continents (Europe, North America and Australasia), using eggs of starlings (Sturnus vulgaris and Sturnus unicolor) to assess their suitability for large-scale monitoring studies. To the best of our knowledge, this is the first study using bird eggs of the same species as a biomonitor for OHCs on an intercontinental scale. We found significant differences in OHC concentrations of the eggs among sampling locations, except for hexachlorocyclohexanes (HCHs). Mean concentrations of sum polychlorinated biphenyls (PCBs) in eggs ranged from 78±26 ng/glipid weight (lw) in Australia to 2900±1300 ng/g lw in the United States. The PCB profile was dominated by CB 153 and CB 138 in all locations, except for New Zealand, where the contribution of CB 95, CB 101 and CB 149 was also high. The highest mean sum polybrominated diphenyl ether (PBDE) concentrations were found in Canada (4400±830 ng/g lw), while the lowest mean PBDE concentrations were measured in Spain (3.7±0.1 ng/g lw). The PBDE profile in starling eggs was dominated by BDE 47 and BDE 99 in all countries, but in Belgium, the higher brominated PBDEs had a higher contribution compared to other countries. For the organochlorine pesticides (OCPs), dichlorodiphenyltrichloroethanes (DDTs) ranged from 110±16 ng/g lw in France to 17,000±3400 ng/g lw in New Zealand, while HCHs and hexachlorobenzene were generally in low concentrations in all sampling locations. Chlordanes were remarkably high in eggs from the United States (2500±1300 ng/g lw). The OCP profile in all countries was largely dominated by p,p'-DDE. In general, the worldwide trends we observed in starling eggs were in accordance with the literature on human and environmental OHC data, which suggests that there is potential for using starling eggs as a biomonitoring tool on a large geographical scale.


Asunto(s)
Monitoreo del Ambiente/métodos , Contaminantes Ambientales/metabolismo , Hidrocarburos Clorados/metabolismo , Óvulo/metabolismo , Estorninos , Animales , Contaminación Ambiental/estadística & datos numéricos , Éteres Difenilos Halogenados/metabolismo , Plaguicidas/metabolismo , Bifenilos Policlorados/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA