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1.
Ecol Lett ; 27(7): e14461, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38953253

RESUMEN

Under the recently adopted Kunming-Montreal Global Biodiversity Framework, 196 Parties committed to reporting the status of genetic diversity for all species. To facilitate reporting, three genetic diversity indicators were developed, two of which focus on processes contributing to genetic diversity conservation: maintaining genetically distinct populations and ensuring populations are large enough to maintain genetic diversity. The major advantage of these indicators is that they can be estimated with or without DNA-based data. However, demonstrating their feasibility requires addressing the methodological challenges of using data gathered from diverse sources, across diverse taxonomic groups, and for countries of varying socio-economic status and biodiversity levels. Here, we assess the genetic indicators for 919 taxa, representing 5271 populations across nine countries, including megadiverse countries and developing economies. Eighty-three percent of the taxa assessed had data available to calculate at least one indicator. Our results show that although the majority of species maintain most populations, 58% of species have populations too small to maintain genetic diversity. Moreover, genetic indicator values suggest that IUCN Red List status and other initiatives fail to assess genetic status, highlighting the critical importance of genetic indicators.


Asunto(s)
Biodiversidad , Conservación de los Recursos Naturales , Variación Genética , Animales
2.
Proc Natl Acad Sci U S A ; 118(27)2021 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-34183409

RESUMEN

Australia has the highest historically recorded rate of mammalian extinction in the world, with 34 terrestrial species declared extinct since European colonization in 1788. Among Australian mammals, rodents have been the most severely affected by these recent extinctions; however, given a sparse historical record, the scale and timing of their decline remain unresolved. Using museum specimens up to 184 y old, we generate genomic-scale data from across the entire assemblage of Australian hydromyine rodents (i.e., eight extinct species and their 42 living relatives). We reconstruct a phylogenomic tree for these species spanning ∼5.2 million years, revealing a cumulative total of 10 million years (>10%) of unique evolutionary history lost to extinction within the past ∼150 y. We find no evidence for reduced genetic diversity in extinct species just prior to or during decline, indicating that their extinction was extremely rapid. This suggests that populations of extinct Australian rodents were large prior to European colonization, and that genetic diversity does not necessarily protect species from catastrophic extinction. In addition, comparative analyses suggest that body size and biome interact to predict extinction and decline, with larger species more likely to go extinct. Finally, we taxonomically resurrect a species from extinction, Gould's mouse (Pseudomys gouldii Waterhouse, 1839), which survives as an island population in Shark Bay, Western Australia (currently classified as Pseudomys fieldi Waite, 1896). With unprecedented sampling across a radiation of extinct and living species, we unlock a previously inaccessible historical perspective on extinction in Australia. Our results highlight the capacity of collections-based research to inform conservation and management of persisting species.


Asunto(s)
Extinción Biológica , Genómica , Museos , Roedores/genética , Animales , Australia , Calibración , Europa (Continente) , Exoma/genética , Variación Genética , Genoma , Heterocigoto , Filogenia , Riesgo , Especificidad de la Especie
3.
Mol Ecol ; 2023 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-37715549

RESUMEN

Translocation programmes are increasingly being informed by genetic data to monitor and enhance conservation outcomes for both natural and established populations. These data provide a window into contemporary patterns of genetic diversity, structure and relatedness that can guide managers in how to best source animals for their translocation programmes. The inclusion of historical samples, where possible, strengthens monitoring by allowing assessment of changes in genetic diversity over time and by providing a benchmark for future improvements in diversity via management practices. Here, we used reduced representation sequencing (ddRADseq) data to report on the current genetic health of three remnant and seven translocated boodie (Bettongia lesueur) populations, now extinct on the Australian mainland. In addition, we used exon capture data from seven historical mainland specimens and a subset of contemporary samples to compare pre-decline and current diversity. Both data sets showed the significant impact of population founder source (whether multiple or single) on the genetic diversity of translocated populations. Populations founded by animals from multiple sources showed significantly higher genetic diversity than the natural remnant and single-source translocation populations, and we show that by mixing the most divergent populations, exon capture heterozygosity was restored to levels close to that observed in pre-decline mainland samples. Relatedness estimates were surprisingly low across all contemporary populations and there was limited evidence of inbreeding. Our results show that a strategy of genetic mixing has led to successful conservation outcomes for the species in terms of increasing genetic diversity and provides strong rationale for mixing as a management strategy.

4.
Conserv Genet ; 24(2): 181-191, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36683963

RESUMEN

Genetic diversity among and within populations of all species is necessary for people and nature to survive and thrive in a changing world. Over the past three years, commitments for conserving genetic diversity have become more ambitious and specific under the Convention on Biological Diversity's (CBD) draft post-2020 global biodiversity framework (GBF). This Perspective article comments on how goals and targets of the GBF have evolved, the improvements that are still needed, lessons learned from this process, and connections between goals and targets and the actions and reporting that will be needed to maintain, protect, manage and monitor genetic diversity. It is possible and necessary that the GBF strives to maintain genetic diversity within and among populations of all species, to restore genetic connectivity, and to develop national genetic conservation strategies, and to report on these using proposed, feasible indicators.

5.
Mol Ecol ; 31(21): 5468-5486, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36056907

RESUMEN

Mammal declines across northern Australia are one of the major biodiversity loss events occurring globally. There has been no regional assessment of the implications of these species declines for genomic diversity. To address this, we conducted a species-wide assessment of genomic diversity in the northern quoll (Dasyurus hallucatus), an Endangered marsupial carnivore. We used next generation sequencing methods to genotype 10,191 single nucleotide polymorphisms (SNPs) in 352 individuals from across a 3220-km length of the continent, investigating patterns of population genomic structure and diversity, and identifying loci showing signals of putative selection. We found strong heterogeneity in the distribution of genomic diversity across the continent, characterized by (i) biogeographical barriers driving hierarchical population structure through long-term isolation, and (ii) severe reductions in diversity resulting from population declines, exacerbated by the spread of introduced toxic cane toads (Rhinella marina). These results warn of a large ongoing loss of genomic diversity and associated adaptive capacity as mammals decline across northern Australia. Encouragingly, populations of the northern quoll established on toad-free islands by translocations appear to have maintained most of the initial genomic diversity after 16 years. By mapping patterns of genomic diversity within and among populations, and investigating these patterns in the context of population declines, we can provide conservation managers with data critical to informed decision-making. This includes the identification of populations that are candidates for genetic management, the importance of remnant island and insurance/translocated populations for the conservation of genetic diversity, and the characterization of putative evolutionarily significant units.


Asunto(s)
Marsupiales , Metagenómica , Animales , Bufo marinus/genética , Conducta Predatoria , Marsupiales/genética , Australia/epidemiología
6.
Bioscience ; 71(9): 964-976, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34475806

RESUMEN

Global conservation policy and action have largely neglected protecting and monitoring genetic diversity-one of the three main pillars of biodiversity. Genetic diversity (diversity within species) underlies species' adaptation and survival, ecosystem resilience, and societal innovation. The low priority given to genetic diversity has largely been due to knowledge gaps in key areas, including the importance of genetic diversity and the trends in genetic diversity change; the perceived high expense and low availability and the scattered nature of genetic data; and complicated concepts and information that are inaccessible to policymakers. However, numerous recent advances in knowledge, technology, databases, practice, and capacity have now set the stage for better integration of genetic diversity in policy instruments and conservation efforts. We review these developments and explore how they can support improved consideration of genetic diversity in global conservation policy commitments and enable countries to monitor, report on, and take action to maintain or restore genetic diversity.

7.
Transfusion ; 61(5): 1383-1388, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33569779

RESUMEN

BACKGROUND: Platelets are the most commonly discarded blood product in Canada, with the most common cause of in-date product loss being improper storage. Transport containers to maintain temperature and extend acceptable return time may represent a method to reduce wastage. The objective of this study was to evaluate the impact of a validated Platelet Transport Bag (PTB) on platelet wastage. STUDY DESIGN AND METHODS: Thirty-six hospitals with the highest platelet discards were invited to participate in a before-after observational study. Hospitals were instructed to utilize a validated 4-h PTB for clinical situations where immediate transfusion was not planned. Five hospitals audited in-date platelet discards from July 2018 to November 2019 to characterize wastage causes. In-date platelet discard data 12 months before and after the start date for each site were analyzed to determine changes in wastage. RESULTS: Of 36 hospital sites, 16 agreed to participate. Pre- and postdiscards were 277 and 301, respectively, for all sites combined. There were no significant before-after change in wastage rate (+0.05%, p = .51). Fifty discards were included in the detailed audit; the most common reasons were return to the blood bank after more than 60 min outside a PTB (n = 17, 34%) and return in a red cell cooler (n = 10, 20%). CONCLUSION: Implementation of PTB did not improve wastage. Common causes of in-date discards were return after 1 h outside of a PTB and placement in a red cell cooler in error. Further research is required to investigate potential strategies to mitigate in-date platelet wastage.


Asunto(s)
Plaquetas , Conservación de la Sangre , Residuos Sanitarios , Bancos de Sangre/organización & administración , Plaquetas/citología , Canadá , Frío , Hospitales , Humanos
8.
J Med Internet Res ; 23(6): e25069, 2021 06 11.
Artículo en Inglés | MEDLINE | ID: mdl-34114957

RESUMEN

BACKGROUND: Many young adult patients do not receive adequate psychosocial services to help them cope with cancer. OBJECTIVE: This study aims to assess the feasibility and acceptability of a smartphone app (iaya) intervention that was designed to create an engaged community of young adult patients and help them learn emotional coping skills. METHODS: For this single-group pilot trial, 25 young adult patients aged 18-39 years who were receiving active cancer treatment were asked to use the iaya app for 12 weeks. To collect app use data, we used Mixpanel, an analytics platform for apps. Feasibility was assessed through rates of app sessions and the number of coping exercises engaged, and intervention acceptability was evaluated by using an app usability questionnaire and through qualitative interviews at study completion. We collected patient-reported outcome data at baseline and at week 12 to explore self-efficacy for coping with cancer, self-efficacy for managing emotions, perceived emotional support, and quality of life. RESULTS: Baseline patient-reported outcome data indicated that participants scored relatively low on perceived emotional support but reasonably high on self-efficacy for coping with cancer and managing emotions as well as quality of life. Participants had a mean of 13 app sessions (SD 14) and 2 coping exercises (SD 3.83) in 12 weeks. Only 9% (2/23) of participants met our combined feasibility definition of ≥10 app sessions and ≥3 coping skills from different categories. The participants' mean usability score was 73.7% (SD 10.84), which exceeded our predefined threshold of ≥70%, and qualitative feedback was generally positive. CONCLUSIONS: Although perceived acceptable by patients, the iaya smartphone app did not meet the a priori feasibility criteria as a stand-alone app intervention. Future studies should screen participants for unmet coping needs and consider integrating the app as part of psychosocial care for young adult patients.


Asunto(s)
Teléfono Celular , Aplicaciones Móviles , Neoplasias , Adaptación Psicológica , Estudios de Factibilidad , Humanos , Neoplasias/terapia , Proyectos Piloto , Calidad de Vida , Adulto Joven
9.
Disasters ; 45 Suppl 1: S195-S215, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34553404

RESUMEN

Discussions on African responses to Covid-19 have focused on the state and its international backers. Far less is known about a wider range of public authorities, including chiefs, humanitarians, criminal gangs, and armed groups. This paper investigates how the pandemic provided opportunities for claims to and contests over power in Uganda, the Democratic Republic of the Congo, and South Sudan. Ethnographic research is used to contend that local forms of public authority can be akin to miniature sovereigns, able to interpret dictates, policies, and advice as required. Alongside coping with existing complex protracted emergencies, many try to advance their own agendas and secure benefits. Those they seek to govern, though, do not passively accept the new normal, instead often challenging those in positions of influence. This paper assesses which of these actions and reactions will have lasting effects on local notions of statehood and argues for a public authorities lens in times of crisis.


Asunto(s)
COVID-19 , República Democrática del Congo , Humanos , SARS-CoV-2 , Sudán del Sur/epidemiología , Uganda
10.
Hum Psychopharmacol ; 30(5): 341-9, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25900350

RESUMEN

OBJECTIVE: While the role of dopamine in modulating executive function, working memory and associative learning has been established; its role in word learning and language processing more generally is not clear. This preliminary study investigated the impact of increased synaptic dopamine levels on new-word learning ability in healthy young adults using an explicit learning paradigm. METHOD: A double-blind, placebo-controlled, between-groups design was used. Participants completed five learning sessions over 1 week with levodopa or placebo administered at each session (five doses, 100 mg). Each session involved a study phase followed by a test phase. Test phases involved recall and recognition tests of the new (non-word) names previously paired with unfamiliar objects (half with semantic descriptions) during the study phase. RESULTS: The levodopa group showed superior recall accuracy for new words over five learning sessions compared with the placebo group and better recognition accuracy at a 1-month follow-up for words learnt with a semantic description. CONCLUSIONS: These findings suggest that dopamine boosts initial lexical acquisition and enhances longer-term consolidation of words learnt with semantic information, consistent with dopaminergic enhancement of semantic salience.


Asunto(s)
Dopaminérgicos/farmacología , Lenguaje , Aprendizaje/efectos de los fármacos , Levodopa/farmacología , Adulto , Dopaminérgicos/administración & dosificación , Método Doble Ciego , Femenino , Estudios de Seguimiento , Voluntarios Sanos , Humanos , Levodopa/administración & dosificación , Masculino , Memoria a Largo Plazo/efectos de los fármacos , Recuerdo Mental/efectos de los fármacos , Proyectos Piloto , Reconocimiento en Psicología/efectos de los fármacos , Adulto Joven
11.
Mol Ecol ; 23(14): 3419-33, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24943509

RESUMEN

Rapid increases in global trade and human movement have created novel mixtures of organisms bringing with them the potential to rapidly accelerate the evolution of new forms. The common brushtail possum (Trichosurus vulpecula), introduced into New Zealand from Australia in the 19th century, is one such species having been sourced from multiple populations in its native range. Here, we combine microsatellite DNA- and GIS-based spatial data to show that T. vulpecula originating from at least two different Australian locations exhibit a population structure that is commensurate with their introduction history and which cannot be explained by landscape features alone. Most importantly, we identify a hybrid zone between the two subspecies which appears to function as a barrier to dispersal. When combined with previous genetic, morphological and captive studies, our data suggest that assortative mating between the two subspecies may operate at a behavioural or species recognition level rather than through fertilization, genetic incompatibility or developmental inhibition. Nevertheless, hybridization between the two subspecies of possum clearly occurs, creating the opportunity for novel genetic combinations that would not occur in their natural ranges and which is especially likely given that multiple contact zones occur in New Zealand. This discovery has implications for wildlife management in New Zealand because multiple contact zones are likely to influence the dispersal patterns of possums and because differential susceptibility to baiting with sodium fluoroacetate between possums of different origins may promote novel genetic forms.


Asunto(s)
Evolución Biológica , Genética de Población , Trichosurus/genética , Distribución Animal , Animales , Australia , Teorema de Bayes , Femenino , Genotipo , Hibridación Genética , Especies Introducidas , Masculino , Repeticiones de Microsatélite , Datos de Secuencia Molecular , Nueva Zelanda , Análisis de Secuencia de ADN
13.
Commun Biol ; 7(1): 636, 2024 May 25.
Artículo en Inglés | MEDLINE | ID: mdl-38796620

RESUMEN

The eastern quoll (Dasyurus viverrinus) is an endangered marsupial native to Australia. Since the extirpation of its mainland populations in the 20th century, wild eastern quolls have been restricted to two islands at the southern end of their historical range. Eastern quolls are the subject of captive breeding programs and attempts have been made to re-establish a population in mainland Australia. However, few resources currently exist to guide the genetic management of this species. Here, we generated a reference genome for the eastern quoll with gene annotations supported by multi-tissue transcriptomes. Our assembly is among the most complete marsupial genomes currently available. Using this assembly, we infer the species' demographic history, identifying potential evidence of a long-term decline beginning in the late Pleistocene. Finally, we identify a deletion at the ASIP locus that likely underpins pelage color differences between the eastern quoll and the closely related Tasmanian devil (Sarcophilus harrisii).


Asunto(s)
Especies en Peligro de Extinción , Genoma , Marsupiales , Animales , Marsupiales/genética , Australia , Pigmentación/genética , Evolución Biológica , Transcriptoma
14.
Lancet Child Adolesc Health ; 8(5): 325-338, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38513681

RESUMEN

BACKGROUND: Sepsis is defined as dysregulated host response to infection that leads to life-threatening organ dysfunction. Biomarkers characterising the dysregulated host response in sepsis are lacking. We aimed to develop host gene expression signatures to predict organ dysfunction in children with bacterial or viral infection. METHODS: This cohort study was done in emergency departments and intensive care units of four hospitals in Queensland, Australia, and recruited children aged 1 month to 17 years who, upon admission, underwent a diagnostic test, including blood cultures, for suspected sepsis. Whole-blood RNA sequencing of blood was performed with Illumina NovaSeq (San Diego, CA, USA). Samples with completed phenotyping, monitoring, and RNA extraction by March 31, 2020, were included in the discovery cohort; samples collected or completed thereafter and by Oct 27, 2021, constituted the Rapid Paediatric Infection Diagnosis in Sepsis (RAPIDS) internal validation cohort. An external validation cohort was assembled from RNA sequencing gene expression count data from the observational European Childhood Life-threatening Infectious Disease Study (EUCLIDS), which recruited children with severe infection in nine European countries between 2012 and 2016. Feature selection approaches were applied to derive novel gene signatures for disease class (bacterial vs viral infection) and disease severity (presence vs absence of organ dysfunction 24 h post-sampling). The primary endpoint was the presence of organ dysfunction 24 h after blood sampling in the presence of confirmed bacterial versus viral infection. Gene signature performance is reported as area under the receiver operating characteristic curves (AUCs) and 95% CI. FINDINGS: Between Sept 25, 2017, and Oct 27, 2021, 907 patients were enrolled. Blood samples from 595 patients were included in the discovery cohort, and samples from 312 children were included in the RAPIDS validation cohort. We derived a ten-gene disease class signature that achieved an AUC of 94·1% (95% CI 90·6-97·7) in distinguishing bacterial from viral infections in the RAPIDS validation cohort. A ten-gene disease severity signature achieved an AUC of 82·2% (95% CI 76·3-88·1) in predicting organ dysfunction within 24 h of sampling in the RAPIDS validation cohort. Used in tandem, the disease class and disease severity signatures predicted organ dysfunction within 24 h of sampling with an AUC of 90·5% (95% CI 83·3-97·6) for patients with predicted bacterial infection and 94·7% (87·8-100·0) for patients with predicted viral infection. In the external EUCLIDS validation dataset (n=362), the disease class and disease severity predicted organ dysfunction at time of sampling with an AUC of 70·1% (95% CI 44·1-96·2) for patients with predicted bacterial infection and 69·6% (53·1-86·0) for patients with predicted viral infection. INTERPRETATION: In children evaluated for sepsis, novel host transcriptomic signatures specific for bacterial and viral infection can identify dysregulated host response leading to organ dysfunction. FUNDING: Australian Government Medical Research Future Fund Genomic Health Futures Mission, Children's Hospital Foundation Queensland, Brisbane Diamantina Health Partners, Emergency Medicine Foundation, Gold Coast Hospital Foundation, Far North Queensland Foundation, Townsville Hospital and Health Services SERTA Grant, and Australian Infectious Diseases Research Centre.


Asunto(s)
Infecciones Bacterianas , Sepsis , Virosis , Humanos , Niño , Estudios de Cohortes , Transcriptoma , Insuficiencia Multiorgánica/diagnóstico , Insuficiencia Multiorgánica/genética , Estudios Prospectivos , Australia , Sepsis/diagnóstico , Sepsis/genética
15.
Open Forum Infect Dis ; 10(1): ofac665, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36726549

RESUMEN

Background: An increase in infections with nontuberculous mycobacteria (NTM) has been noted globally, and their incidence has overtaken that of Mycobacterium tuberculosis complex (MTBc) in many countries. Using data from a national reference laboratory, we aimed to determine if this trend could be observed in Scotland. Methods: We undertook a retrospective review of all NTM isolates received by the Scottish Mycobacteria Reference Laboratory (SMRL) over 9 years from 2011 to 2019 inclusive. Clinical episodes were defined as per 2017 British Thoracic Society and 2020 American Thoracic Society/European Respiratory Society/European Society of Clinical Microbiology and Infectious Diseases/Infectious Diseases Society of America NTM guidelines. These rates were compared with Scottish tuberculosis rates over the same period. Results: Of 8552 NTM isolates from 4586 patients in 2011 to 2019, 7739 (90.5%) were considered clinically relevant. These represented 2409 episodes of NTM infection, with M. avium, M. intracellulare, and M. abscessus complex being most common. A total of 1953 (81.1%) were pulmonary NTM infection episodes from 1470 patients and 456 extrapulmonary episodes from 370 patients. We estimated a rise in incidence from 3.4 to 6.5 per 100 000 person-years (2011-2019 inclusive), with an increase in NTM incidence over MTBc incidence in Scotland by 2017. Conclusions: The incidence of NTM infection in Scotland has overtaken MTBc incidence. NTM infection leads to a costly health care burden, possibly as much as UK£1.47 million (US$ and €1.73 million) annually. We recommend standardization of isolate referral with clinical surveillance and implementation of agreed standards of care delivered through multidisciplinary teams. This would improve diagnosis and patient management as well as assessment of diagnostics and novel treatments through clinical trials.

16.
BMJ Open ; 13(8): e075429, 2023 08 30.
Artículo en Inglés | MEDLINE | ID: mdl-37648380

RESUMEN

INTRODUCTION: Despite growing awareness of neurodevelopmental impairments in children with congenital heart disease (CHD), there is a lack of large, longitudinal, population-based cohorts. Little is known about the contemporary neurodevelopmental profile and the emergence of specific impairments in children with CHD entering school. The performance of standardised screening tools to predict neurodevelopmental outcomes at school age in this high-risk population remains poorly understood. The NITric oxide during cardiopulmonary bypass to improve Recovery in Infants with Congenital heart defects (NITRIC) trial randomised 1371 children <2 years of age, investigating the effect of gaseous nitric oxide applied into the cardiopulmonary bypass oxygenator during heart surgery. The NITRIC follow-up study will follow this cohort annually until 5 years of age to assess outcomes related to cognition and socioemotional behaviour at school entry, identify risk factors for adverse outcomes and evaluate the performance of screening tools. METHODS AND ANALYSIS: Approximately 1150 children from the NITRIC trial across five sites in Australia and New Zealand will be eligible. Follow-up assessments will occur in two stages: (1) annual online screening of global neurodevelopment, socioemotional and executive functioning, health-related quality of life and parenting stress at ages 2-5 years; and (2) face-to-face assessment at age 5 years assessing intellectual ability, attention, memory and processing speed; fine motor skills; language and communication; and socioemotional outcomes. Cognitive and socioemotional outcomes and trajectories of neurodevelopment will be described and demographic, clinical, genetic and environmental predictors of these outcomes will be explored. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Children's Health Queensland (HREC/20/QCHQ/70626) and New Zealand Health and Disability (21/NTA/83) Research Ethics Committees. The findings will inform the development of clinical decision tools and improve preventative and intervention strategies in children with CHD. Dissemination of the outcomes of the study is expected via publications in peer-reviewed journals, presentation at conferences, via social media, podcast presentations and medical education resources, and through CHD family partners. TRIAL REGISTRATION NUMBER: The trial was prospectively registered with the Australian New Zealand Clinical Trials Registry as 'Gene Expression to Predict Long-Term Neurodevelopmental Outcome in Infants from the NITric oxide during cardiopulmonary bypass to improve Recovery in Infants with Congenital heart defects (NITRIC) Study - A Multicentre Prospective Trial'. TRIAL REGISTRATION: ACTRN12621000904875.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Óxido Nítrico , Lactante , Niño , Humanos , Anciano , Preescolar , Estudios de Seguimiento , Estudios Longitudinales , Nueva Zelanda , Estudios Prospectivos , Calidad de Vida , Australia , Estudios de Cohortes
17.
BMC Neurosci ; 13: 21, 2012 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-22364354

RESUMEN

BACKGROUND: Overt repetition of auditorily presented words can facilitate picture naming performance in both unimpaired speakers and individuals with word retrieval difficulties, but the underlying neurocognitive mechanisms and longevity of such effects remain unclear. This study used functional magnetic resonance imaging to examine whether different neurological mechanisms underlie short-term (within minutes) and long-term (within days) facilitation effects from an auditory repetition task in healthy older adults. RESULTS: The behavioral results showed that both short- and long-term facilitated items were named significantly faster than unfacilitated items, with short-term items significantly faster than long-term items. Neuroimaging analyses identified a repetition suppression effect for long-term facilitated items, relative to short-term facilitated and unfacilitated items, in regions known to be associated with both semantic and phonological processing. A repetition suppression effect was also observed for short-term facilitated items when compared to unfacilitated items in a region of the inferior temporal lobe linked to semantic processing and object recognition, and a repetition enhancement effect when compared to long-term facilitated items in a posterior superior temporal region associated with phonological processing. CONCLUSIONS: These findings suggest that different neurocognitive mechanisms underlie short- and long-term facilitation of picture naming by an auditory repetition task, reflecting both phonological and semantic processing. More specifically, the brain areas engaged were consistent with the view that long-term facilitation may be driven by a strengthening of semantic-phonological connections. Short-term facilitation, however, appears to result in more efficient semantic processing and/or object recognition, possibly in conjunction with active recognition of the phonological form.


Asunto(s)
Estimulación Acústica/métodos , Mapeo Encefálico , Encéfalo/fisiología , Nombres , Reconocimiento en Psicología/fisiología , Adulto , Anciano , Encéfalo/irrigación sanguínea , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Fonética , Estimulación Luminosa , Tiempo de Reacción , Semántica , Factores de Tiempo
18.
BMC Neurosci ; 13: 98, 2012 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-22882806

RESUMEN

BACKGROUND: Previous attempts to investigate the effects of semantic tasks on picture naming in both healthy controls and people with aphasia have typically been confounded by inclusion of the phonological word form of the target item. As a result, it is difficult to isolate any facilitatory effects of a semantically-focused task to either lexical-semantic or phonological processing. This functional magnetic resonance imaging (fMRI) study examined the neurological mechanisms underlying short-term (within minutes) and long-term (within days) facilitation of naming from a semantic task that did not include the phonological word form, in both participants with aphasia and age-matched controls. RESULTS: Behavioral results showed that a semantic task that did not include the phonological word form can successfully facilitate subsequent picture naming in both healthy controls and individuals with aphasia. The whole brain neuroimaging results for control participants identified a repetition enhancement effect in the short-term, with modulation of activity found in regions that have not traditionally been associated with semantic processing, such as the right lingual gyrus (extending to the precuneus) and the left inferior occipital gyrus (extending to the fusiform gyrus). In contrast, the participants with aphasia showed significant differences in activation over both the short- and the long-term for facilitated items, predominantly within either left hemisphere regions linked to semantic processing or their right hemisphere homologues. CONCLUSIONS: For control participants in this study, the short-lived facilitation effects of a prior semantic task that did not include the phonological word form were primarily driven by object priming and episodic memory mechanisms. However, facilitation effects appeared to engage a predominantly semantic network in participants with aphasia over both the short- and the long-term. The findings of the present study also suggest that right hemisphere involvement may be supportive rather than maladaptive, and that a large distributed perisylvian network in both cerebral hemispheres supports the facilitation of naming in individuals with aphasia.


Asunto(s)
Afasia/patología , Mapeo Encefálico , Encéfalo/irrigación sanguínea , Nombres , Semántica , Adulto , Anciano , Afasia/fisiopatología , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Oxígeno/sangre , Estimulación Luminosa , Tiempo de Reacción/fisiología , Estadísticas no Paramétricas
19.
Curr Biol ; 32(19): 4215-4224.e3, 2022 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-36057260

RESUMEN

Sahul unites the world's largest and highest tropical island and the oldest and most arid continent on the backdrop of dynamic environmental conditions. Massive geological uplift in New Guinea is predicted to have acted as a species pump from the late Miocene onward, but the impact of this process on biogeography and diversification remains untested across Sahul as a whole. To address this, we reconstruct the assembly of a recent and diverse radiation of rodents (Murinae: Hydromyini) spanning New Guinea, Australia, and oceanic islands. Using phylogenomic data from 270 specimens, including many recently extinct and highly elusive species, we find that the orogeny and expansion of New Guinea opened ecological opportunity and triggered diversification across a continent. After a single over-water colonization from Asia ca. 8.5 Ma, ancestral Hydromyini were restricted to the tropical rainforest of proto-New Guinea for 3.5 million years. Following a shift in diversification coincident with the orogeny of New Guinea ca. 5 Ma and subsequent colonization of Australia, transitions between geographic regions (n = 24) and biomes (n = 34) become frequent. Recurrent over-water colonization between mainland and islands demonstrate how islands can play a substantial role in the assembly of continental fauna. Our results are consistent with a model of increased ecological opportunity across Sahul following major geological uplift in New Guinea ca. 5 Ma, with sustained diversification facilitated by over-water colonization from the Pleistocene to present. We show how geological processes, biome transitions, and over-water colonization collectively drove the diversification of an expansive continental radiation.


Asunto(s)
Ecosistema , Roedores , Animales , Nueva Guinea , Filogenia , Filogeografía , Agua
20.
Biol Rev Camb Philos Soc ; 97(4): 1511-1538, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35415952

RESUMEN

Biodiversity underlies ecosystem resilience, ecosystem function, sustainable economies, and human well-being. Understanding how biodiversity sustains ecosystems under anthropogenic stressors and global environmental change will require new ways of deriving and applying biodiversity data. A major challenge is that biodiversity data and knowledge are scattered, biased, collected with numerous methods, and stored in inconsistent ways. The Group on Earth Observations Biodiversity Observation Network (GEO BON) has developed the Essential Biodiversity Variables (EBVs) as fundamental metrics to help aggregate, harmonize, and interpret biodiversity observation data from diverse sources. Mapping and analyzing EBVs can help to evaluate how aspects of biodiversity are distributed geographically and how they change over time. EBVs are also intended to serve as inputs and validation to forecast the status and trends of biodiversity, and to support policy and decision making. Here, we assess the feasibility of implementing Genetic Composition EBVs (Genetic EBVs), which are metrics of within-species genetic variation. We review and bring together numerous areas of the field of genetics and evaluate how each contributes to global and regional genetic biodiversity monitoring with respect to theory, sampling logistics, metadata, archiving, data aggregation, modeling, and technological advances. We propose four Genetic EBVs: (i) Genetic Diversity; (ii) Genetic Differentiation; (iii) Inbreeding; and (iv) Effective Population Size (Ne ). We rank Genetic EBVs according to their relevance, sensitivity to change, generalizability, scalability, feasibility and data availability. We outline the workflow for generating genetic data underlying the Genetic EBVs, and review advances and needs in archiving genetic composition data and metadata. We discuss how Genetic EBVs can be operationalized by visualizing EBVs in space and time across species and by forecasting Genetic EBVs beyond current observations using various modeling approaches. Our review then explores challenges of aggregation, standardization, and costs of operationalizing the Genetic EBVs, as well as future directions and opportunities to maximize their uptake globally in research and policy. The collection, annotation, and availability of genetic data has made major advances in the past decade, each of which contributes to the practical and standardized framework for large-scale genetic observation reporting. Rapid advances in DNA sequencing technology present new opportunities, but also challenges for operationalizing Genetic EBVs for biodiversity monitoring regionally and globally. With these advances, genetic composition monitoring is starting to be integrated into global conservation policy, which can help support the foundation of all biodiversity and species' long-term persistence in the face of environmental change. We conclude with a summary of concrete steps for researchers and policy makers for advancing operationalization of Genetic EBVs. The technical and analytical foundations of Genetic EBVs are well developed, and conservation practitioners should anticipate their increasing application as efforts emerge to scale up genetic biodiversity monitoring regionally and globally.


Asunto(s)
Biodiversidad , Ecosistema , Conservación de los Recursos Naturales/métodos , Variación Genética , Humanos , Densidad de Población
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