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1.
PLoS Biol ; 21(4): e3002068, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37011096

RESUMO

Given the requisite cost associated with observing species interactions, ecologists often reuse species interaction networks created by different sets of researchers to test their hypotheses regarding how ecological processes drive network topology. Yet, topological properties identified across these networks may not be sufficiently attributable to ecological processes alone as often assumed. Instead, much of the totality of topological differences between networks-topological heterogeneity-could be due to variations in research designs and approaches that different researchers use to create each species interaction network. To evaluate the degree to which this topological heterogeneity is present in available ecological networks, we first compared the amount of topological heterogeneity across 723 species interaction networks created by different sets of researchers with the amount quantified from non-ecological networks known to be constructed following more consistent approaches. Then, to further test whether the topological heterogeneity was due to differences in study designs, and not only to inherent variation within ecological networks, we compared the amount of topological heterogeneity between species interaction networks created by the same sets of researchers (i.e., networks from the same publication) with the amount quantified between networks that were each from a unique publication source. We found that species interaction networks are highly topologically heterogeneous: while species interaction networks from the same publication are much more topologically similar to each other than interaction networks that are from a unique publication, they still show at least twice as much heterogeneity as any category of non-ecological networks that we tested. Altogether, our findings suggest that extra care is necessary to effectively analyze species interaction networks created by different researchers, perhaps by controlling for the publication source of each network.

2.
Proc Natl Acad Sci U S A ; 120(20): e2211288120, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37155860

RESUMO

Effective conservation of ecological communities requires accurate and up-to-date information about whether species are persisting or declining to extinction. The persistence of an ecological community is supported by its underlying network of species interactions. While the persistence of the network supporting the whole community is the most relevant scale for conservation, in practice, only small subsets of these networks can be monitored. There is therefore an urgent need to establish links between the small snapshots of data conservationists can collect, and the "big picture" conclusions about ecosystem health demanded by policymakers, scientists, and societies. Here, we show that the persistence of small subnetworks (motifs) in isolation-that is, their persistence when considered separately from the larger network of which they are a part-is a reliable probabilistic indicator of the persistence of the network as a whole. Our methods show that it is easier to detect if an ecological community is not persistent than if it is persistent, allowing for rapid detection of extinction risk in endangered systems. Our results also justify the common practice of predicting ecological persistence from incomplete surveys by simulating the population dynamics of sampled subnetworks. Empirically, we show that our theoretical predictions are supported by data on invaded networks in restored and unrestored areas, even in the presence of environmental variability. Our work suggests that coordinated action to aggregate information from incomplete sampling can provide a means to rapidly assess the persistence of entire ecological networks and the expected success of restoration strategies.


Assuntos
Biota , Ecossistema , Dinâmica Populacional
3.
Clin Transplant ; 38(5): e15338, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38762787

RESUMO

BACKGROUND: Kidney transplantation is the optimal treatment for end-stage renal disease. However, highly sensitized patients (HSPs) have reduced access to transplantation, leading to increased morbidity and mortality on the waiting list. The Canadian Willingness to Cross (WTC) program proposes allowing transplantation across preformed donor specific antibodies (DSA) determined to be at a low risk of rejection under the adaptive design framework. This study collected patients' perspectives on the development of this program. METHODS: Forty-one individual interviews were conducted with kidney transplant candidates from three Canadian transplant centers in 2022. The interviews were digitally recorded and transcribed for subsequent analyses. RESULTS: Despite limited familiarity with the adaptive design, participants demonstrated trust in the researchers. They perceived the WTC program as a pathway for HSPs to access transplantation while mitigating transplant-related risks. HSPs saw the WTC program as a source of hope and an opportunity to leave dialysis, despite acknowledging inherent uncertainties. Some non-HSPs expressed concerns about fairness, anticipating increased waiting times and potential compromise in kidney graft longevity due to higher rejection risks. Participants recommended essential strategies for implementing the WTC program, including organizing informational meetings and highlighting the necessity for psychosocial support. CONCLUSION: The WTC program emerges as a promising strategy to enhance HSPs' access to kidney transplantation. While HSPs perceived this program as a source of hope, non-HSPs voiced concerns about distributive justice issues. These results will help develop a WTC program that is ethically sound for transplant candidates.


Assuntos
Rejeição de Enxerto , Acessibilidade aos Serviços de Saúde , Falência Renal Crônica , Transplante de Rim , Listas de Espera , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Canadá , Falência Renal Crônica/cirurgia , Falência Renal Crônica/psicologia , Adulto , Rejeição de Enxerto/etiologia , Prognóstico , Seguimentos , Sobrevivência de Enxerto , Doadores de Tecidos/provisão & distribuição , Doadores de Tecidos/psicologia , Obtenção de Tecidos e Órgãos , Idoso , Isoanticorpos/imunologia
4.
Med Health Care Philos ; 27(2): 137-154, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38478251

RESUMO

Moral or ethical questions are vital because they affect our daily lives: what is the best choice we can make, the best action to take in a given situation, and ultimately, the best way to live our lives? Health ethics has contributed to moving ethics toward a more experience-based and user-oriented theoretical and methodological stance but remains in our practice an incomplete lever for human development and flourishing. This context led us to envision and develop the stance of a "living ethics", described in this inaugural collective and programmatic paper as an effort to consolidate creative collaboration between a wide array of stakeholders. We engaged in a participatory discussion and collective writing process known as instrumentalist concept analysis. This process included initial local consultations, an exploratory literature review, the constitution of a working group of 21 co-authors, and 8 workshops supporting a collaborative thinking and writing process. First, a living ethics designates a stance attentive to human experience and the role played by morality in human existence. Second, a living ethics represents an ongoing effort to interrogate and scrutinize our moral experiences to facilitate adaptation of people and contexts. It promotes the active and inclusive engagement of both individuals and communities in envisioning and enacting scenarios which correspond to their flourishing as authentic ethical agents. Living ethics encourages meaningful participation of stakeholders because moral questions touch deeply upon who we are and who we want to be. We explain various aspects of a living ethics stance, including its theoretical, methodological, and practical implications as well as some barriers to its enactment based on the reflections resulting from the collaborative thinking and writing process.


Assuntos
Princípios Morais , Humanos , Filosofia Médica
5.
Ecol Lett ; 26(2): 291-301, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36468276

RESUMO

Global ecosystems are facing a deepening biodiversity crisis, necessitating robust approaches to quantifying species extinction risk. The lower limit of the macroecological relationship between species range and body size has long been hypothesized as an estimate of the relationship between the minimum viable range size (MVRS) needed for species persistence and the organismal traits that affect space and resource requirements. Here, we perform the first explicit test of this assumption by confronting the MVRS predicted by the range-body size relationship with an independent estimate based on the scale of synchrony in abundance among spatially separated populations of riverine fish. We provide clear evidence of a positive relationship between the scale of synchrony and species body size, and strong support for the MVRS set by the lower limit of the range-body size macroecological relationship. This MVRS may help prioritize first evaluations for unassessed or data-deficient taxa in global conservation assessments.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Animais , Biodiversidade , Extinção Biológica , Peixes , Espécies em Perigo de Extinção
6.
PLoS Comput Biol ; 18(9): e1010302, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36173959

RESUMO

A ubiquitous pattern in ecological systems is that more abundant species tend to be more generalist; that is, they interact with more species or can occur in wider range of habitats. However, there is no consensus on whether generalism drives abundance (a selection process) or abundance drives generalism (a drift process). As it is difficult to conduct direct experiments to solve this chicken-and-egg dilemma, previous studies have used a causal discovery method based on formal logic and have found that abundance drives generalism. Here, we refine this method by correcting its bias regarding skewed distributions, and employ two other independent causal discovery methods based on nonparametric regression and on information theory, respectively. Contrary to previous work, all three independent methods strongly indicate that generalism drives abundance when applied to datasets on plant-hummingbird communities and reef fishes. Furthermore, we find that selection processes are more important than drift processes in structuring multispecies systems when the environment is variable. Our results showcase the power of the computational causal discovery approach to aid ecological research.


Assuntos
Ecossistema , Teoria da Informação , Causalidade , Consenso
7.
Ecol Lett ; 25(8): 1914-1916, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35610664

RESUMO

Luna et al. (2022) concluded that the environment contributes to explaining specialisation in open plant-pollinator networks. When reproducing their study, we instead found that network size alone largely explained the variation in their specialisation metrics. Thus, we question whether empirical network specialisation is driven by the environment.


Assuntos
Plantas , Polinização , Ecossistema
8.
Proc Biol Sci ; 289(1989): 20222029, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36515114

RESUMO

Habitat destruction and fragmentation are principal causes of species loss. While a local population might go extinct, a metapopulation-populations inhabiting habitat patches connected by dispersal-can persist regionally by recolonizing empty patches. To assess metapopulation persistence, two widely adopted indicators in conservation management are metapopulation capacity and patch importance. However, we face a fundamental limitation in that assessing metapopulation persistence requires that we survey or sample all the patches in a landscape: often these surveys are logistically challenging to conduct and repeat, which raises the question whether we can learn enough about the metapopulation persistence from an incomplete survey. Here, we provide a robust statistical approach to infer metapopulation capacity and patch importance by sampling a portion of all patches. We provided analytic arguments on why the metapopulation capacity and patch importance can be well predicted from sub-samples of habitat patches. Full-factorial simulations with more complex models corroborate our analytic predictions. We applied our model to an empirical metapopulation of mangrove hummingbirds (Amazilia boucardi). On the basis of our statistical framework, we provide some sampling suggestion for monitoring metapopulation persistence. Our approach allows for rapid and effective inference of metapopulation persistence from incomplete patch surveys.


Assuntos
Ecossistema , Modelos Biológicos , Animais , Dinâmica Populacional , Aves
9.
Glob Chang Biol ; 28(14): 4323-4341, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35429213

RESUMO

Natural disturbances exacerbated by novel climate regimes are increasing worldwide, threatening the ability of forest ecosystems to mitigate global warming through carbon sequestration and to provide other key ecosystem services. One way to cope with unknown disturbance events is to promote the ecological resilience of the forest by increasing both functional trait and structural diversity and by fostering functional connectivity of the landscape to ensure a rapid and efficient self-reorganization of the system. We investigated how expected and unexpected variations in climate and biotic disturbances affect ecological resilience and carbon storage in a forested region in southeastern Canada. Using a process-based forest landscape model (LANDIS-II), we simulated ecosystem responses to climate change and insect outbreaks under different forest policy scenarios-including a novel approach based on functional diversification and network analysis-and tested how the potentially most damaging insect pests interact with changes in forest composition and structure due to changing climate and management. We found that climate warming, lengthening the vegetation season, will increase forest productivity and carbon storage, but unexpected impacts of drought and insect outbreaks will drastically reduce such variables. Generalist, non-native insects feeding on hardwood are the most damaging biotic agents for our region, and their monitoring and early detection should be a priority for forest authorities. Higher forest diversity driven by climate-smart management and fostered by climate change that promotes warm-adapted species, might increase disturbance severity. However, alternative forest policy scenarios led to a higher functional and structural diversity as well as functional connectivity-and thus to higher ecological resilience-than conventional management. Our results demonstrate that adopting a landscape-scale perspective by planning interventions strategically in space and adopting a functional trait approach to diversify forests is promising for enhancing ecological resilience under unexpected global change stressors.


Assuntos
Ecossistema , Árvores , Animais , Carbono , Mudança Climática , Florestas , Insetos
10.
Clin Transplant ; 36(5): e14604, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35099833

RESUMO

BACKGROUND: The decision to accept a kidney from a deceased donor can be a difficult one. This study aims to capture the perspectives of transplant candidates (TCs) and kidney transplant recipients (KTRs) on the decision-making process when a deceased kidney is offered. METHODS: We conducted six focus groups with KTRs and TCs. The content of the focus groups was analyzed using the qualitative thematic method. RESULTS: KTRs reported that the experience of being offered a kidney could be difficult because of the circumstances of the offer and unpreparedness to participate in the discussion. Both KTRs and TCs trusted the medical expertise. Age and having experience with dialysis could influence the decision to accept an offer. In order to engage in the discussion, patients wanted to obtain estimates of expected graft survival. Patients did not express interest for a web-based calculator for patient use, but expected transplant physicians to summarize and explain the information that would impact graft survival time. CONCLUSION: TCs and KTRs wanted to be involved in the decision to accept a deceased donor kidney. Tools that can help physicians communicate the risks and benefits of accepting an offer could improve patient participation in the decision-making process.


Assuntos
Transplante de Rim , Obtenção de Tecidos e Órgãos , Sobrevivência de Enxerto , Humanos , Rim , Transplante de Rim/métodos , Doadores de Tecidos , Transplantados , Confiança
11.
Can J Neurol Sci ; 49(2): 203-209, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-33845924

RESUMO

INTRODUCTION: Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarkers are promising tools to help identify the underlying pathology of neurocognitive disorders. In this manuscript, we report our experience with AD CSF biomarkers in 262 consecutive patients in a tertiary care memory clinic. METHODS: We retrospectively reviewed 262 consecutive patients who underwent lumbar puncture (LP) and CSF measurement of AD biomarkers (Aß1-42, total tau or t-tau, and p-tau181). We studied the safety of the procedure and its impact on patient's diagnosis and management. RESULTS: The LP allowed to identify underlying AD pathology in 72 of the 121 patients (59%) with early onset amnestic mild cognitive impairment (aMCI) with a high probability of progression to AD; to distinguish the behavioral/dysexecutive variant of AD from the behavioral variant of frontotemporal dementia (bvFTD) in 25 of the 45 patients (55%) with an atypical neurobehavioral profile; to identify AD as the underlying pathology in 15 of the 27 patients (55%) with atypical or unclassifiable primary progressive aphasia (PPA); and to distinguish AD from other disorders in 9 of the 29 patients (31%) with psychiatric differential diagnoses and 19 of the 40 patients (47%) with lesional differential diagnoses (normal pressure hydrocephalus, encephalitis, prion disease, etc.). No major complications occurred following the LP. INTERPRETATION: Our results suggest that CSF analysis is a safe and effective diagnostic tool in select patients with neurocognitive disorders. We advocate for a wider use of this biomarker in tertiary care memory clinics in Canada.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Doença de Alzheimer/psicologia , Peptídeos beta-Amiloides/líquido cefalorraquidiano , Biomarcadores/líquido cefalorraquidiano , Disfunção Cognitiva/diagnóstico , Humanos , Fragmentos de Peptídeos/líquido cefalorraquidiano , Estudos Retrospectivos , Atenção Terciária à Saúde , Proteínas tau/líquido cefalorraquidiano
12.
Ecol Lett ; 24(4): 791-801, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33619868

RESUMO

Dendritic habitats, such as river ecosystems, promote the persistence of species by favouring spatial asynchronous dynamics among branches. Yet, our understanding of how network topology influences metapopulation synchrony in these ecosystems remains limited. Here, we introduce the concept of fluvial synchrogram to formulate and test expectations regarding the geography of metapopulation synchrony across watersheds. By combining theoretical simulations and an extensive fish population time-series dataset across Europe, we provide evidence that fish metapopulations can be buffered against synchronous dynamics as a direct consequence of network connectivity and branching complexity. Synchrony was higher between populations connected by direct water flow and decayed faster with distance over the Euclidean than the watercourse dimension. Likewise, synchrony decayed faster with distance in headwater than mainstem populations of the same basin. As network topology and flow directionality generate fundamental spatial patterns of synchrony in fish metapopulations, empirical synchrograms can aid knowledge advancement and inform conservation strategies in complex habitats.


Assuntos
Ecossistema , Rios , Animais , Europa (Continente) , Geografia , Dinâmica Populacional
13.
Proc Biol Sci ; 288(1949): 20201889, 2021 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-33906397

RESUMO

Network ecology is an emerging field that allows researchers to conceptualize and analyse ecological networks and their dynamics. Here, we focus on the dynamics of ecological networks in response to environmental changes. Specifically, we formalize how network topologies constrain the dynamics of ecological systems into a unifying framework in network ecology that we refer to as the 'ecological network dynamics framework'. This framework stresses that the interplay between species interaction networks and the spatial layout of habitat patches is key to identifying which network properties (number and weights of nodes and links) and trade-offs among them are needed to maintain species interactions in dynamic landscapes. We conclude that to be functional, ecological networks should be scaled according to species dispersal abilities in response to landscape heterogeneity. Determining how such effective ecological networks change through space and time can help reveal their complex dynamics in a changing world.


Assuntos
Ecologia , Ecossistema
14.
Ecol Appl ; 31(1): e2221, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32866316

RESUMO

Forests are projected to undergo dramatic compositional and structural shifts prompted by global changes, such as climatic changes and intensifying natural disturbance regimes. Future uncertainty makes planning for forest management exceptionally difficult, demanding novel approaches to maintain or improve the ability of forest ecosystems to respond and rapidly reorganize after disturbance events. Adopting a landscape perspective in forest management is particularly important in fragmented forest landscapes where both diversity and connectivity play key roles in determining resilience to global change. In this context, network analysis and functional traits combined with ecological dynamic modeling can help evaluate changes in functional response diversity and connectivity within and among forest stands in fragmented landscapes. Here, we coupled ecological dynamic modeling with functional traits analysis and network theory to analyze forested landscapes as an interconnected network of forest patches. We simulated future forest landscape dynamics in a large landscape in southern Quebec, Canada, under a combination of climate, disturbance, and management scenarios. We depicted the landscape as a functional network, assessed changes in future resilience using indicators at multiple spatial scales, and evaluated if current management practices are suitable for maintaining resilience to simulated changes in regimes. Our results show that climate change would promote forest productivity and favor heat-adapted deciduous species. Changes in natural disturbances will likely have negative impacts on native conifers and will drive changes in forest type composition. Climate change negatively impacted all resilience indicators and triggered losses of functional response diversity and connectivity across the landscape with undesirable consequences on the capacity of these forests to adapt to global change. Also, current management strategies failed to promote resilience at different spatial levels, highlighting the need for a more active and thoughtful approach to forest management under global change. Our study demonstrates the usefulness of combining dynamic landscape-scale simulation modeling with network analyses to evaluate the possible impacts of climate change as well as human and natural disturbances on forest resilience under global change.


Assuntos
Ecossistema , Florestas , Canadá , Mudança Climática , Humanos , Quebeque
15.
Conserv Biol ; 35(3): 909-920, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32785955

RESUMO

The availability of genomic data for an increasing number of species makes it possible to incorporate evolutionary processes into conservation plans. Recent studies show how genetic data can inform spatial conservation prioritization (SCP), but they focus on metrics of diversity and distinctness derived primarily from neutral genetic data sets. Identifying adaptive genetic markers can provide important information regarding the capacity for populations to adapt to environmental change. Yet, the effect of including metrics based on adaptive genomic data into SCP in comparison to more widely used neutral genetic metrics has not been explored. We used existing genomic data on a commercially exploited species, the giant California sea cucumber (Parastichopus californicus), to perform SCP for the coastal region of British Columbia (BC), Canada. Using a RAD-seq data set for 717 P. californicus individuals across 24 sampling locations, we identified putatively adaptive (i.e., candidate) single nucleotide polymorphisms (SNPs) based on genotype-environment associations with seafloor temperature. We calculated various metrics for both neutral and candidate SNPs and compared SCP outcomes with independent metrics and combinations of metrics. Priority areas varied depending on whether neutral or candidate SNPs were used and on the specific metric used. For example, targeting sites with a high frequency of warm-temperature-associated alleles to support persistence under future warming prioritized areas in the southern coastal region. In contrast, targeting sites with high expected heterozygosity at candidate loci to support persistence under future environmental uncertainty prioritized areas in the north. When combining metrics, all scenarios generated intermediate solutions, protecting sites that span latitudinal and thermal gradients. Our results demonstrate that distinguishing between neutral and adaptive markers can affect conservation solutions and emphasize the importance of defining objectives when choosing among various genomic metrics for SCP.


Incorporación de Datos Genómicos Putativamente Neutros y Adaptativos dentro de la Planeación de la Conservación Marina Resumen La disponibilidad de los datos genómicos para un número creciente de especies posibilita la incorporación de los procesos evolutivos dentro de los planes de conservación. Los estudios recientes muestran cómo los datos genéticos pueden informar a la priorización de la conservación espacial (PCE) pero tienden a enfocarse más en las medidas de la diversidad y la distinción derivadas principalmente de los conjuntos de datos genéticos neutrales. La identificación de los marcadores genéticos adaptativos puede proporcionar información importante con respecto a la capacidad de las poblaciones para adaptarse al cambio ambiental. Aun así, no se ha explorado el efecto de la inclusión de las medidas basadas en los datos genéticos adaptativos dentro de la PCE y cómo se comparan con las medidas genéticas neutrales de uso más amplio. Usamos datos genómicos existentes sobre una especie de explotación comercial, el pepino de mar gigante de California (Parastichopus californicus), para realizar la PCE para la región costera de la Columbia Británica (BC) en Canadá. Usamos un conjunto de datos RAD-seq para 717 individuos de la especie P. californicus en 24 localidades de muestreo para identificar los polimorfismos de un solo nucleótido (PSNs) putativamente adaptativos (es decir, candidatos) con base en las asociaciones genotipo-ambiente manifestadas con la temperatura del fondo marino. Calculamos varias medidas para los PSNs neutrales y los PSNs candidatos y comparamos los resultados de la PCE con medidas independientes y con combinaciones de medidas. Las áreas prioritarias variaron dependiendo de si se usaron los SNP neutrales o los candidatos y de la medida específica que se utilizó. Por ejemplo, enfocarse en sitios con una frecuencia alta de alelos asociados con agua cálida para fortalecer la persistencia frente al futuro calentamiento prioriza las áreas en la región del sur de la costa. Al contrario, enfocarse en sitios con una alta heterocigosidad esperada en los loci de los candidatos para fortalecer la persistencia frente a la incertidumbre ambiental prioriza las áreas en la parte norte de la costa. Cuando combinamos las medidas, todos los escenarios generaron soluciones intermedias, protegiendo así los sitios que abarcan gradientes latitudinales y gradientes térmicos. Nuestros resultados demuestran que la distinción entre los marcadores neutrales y los adaptativos puede afectar las soluciones de conservación y también enfatizan la importancia de la definición de los objetivos cuando se elige entre varias medidas genómicas para la PCE.


Assuntos
Conservação dos Recursos Naturais , Genômica , Evolução Biológica , Colúmbia Britânica , Genótipo , Humanos
16.
BMC Med Ethics ; 22(1): 23, 2021 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-33663501

RESUMO

BACKGROUND: Medical assistance in dying (MAID) has been legal in Québec since December 2015 and in the rest of Canada since July 2016. Since then, more than 60 people have donated their organs after MAID. Such donations raise ethical issues about respect of patients' autonomy, potential pressure to choose MAID, the information given to potential donors, the acceptability of directed donations in such a context and the possibility of death by donation. The objective of this study was to explore Québec professionals' perspectives on the ethical issues related to organ donation after MAID. METHODS: We conducted semi-directed interviews with 21 health care professionals involved in organ donation such as intensivists and intensive care nurses, operating room nurses, organ donation nurses and coordinators. RESULTS: The participants were all favourable to organ donation after MAID in order to respect patients' autonomy. They also favoured informing all potential donors of the possibility of donating organs. They highlighted the importance of assessing donors' reasons for requesting MAID during the assessment. They were divided on directed donation, living donation before MAID and death by donation. CONCLUSION: Organ donation after MAID was widely accepted among the participants, based on the principle of respect for the donor's autonomy. The findings of this study only provide the perspectives of Québec health care professionals involved in organ donation. Future studies are needed to gather other stakeholders' perspectives on this issue as well as patients' and families' experiences of organ donation after MAID.


Assuntos
Suicídio Assistido , Obtenção de Tecidos e Órgãos , Canadá , Pessoal de Saúde , Humanos , Assistência Médica
17.
BMC Med Ethics ; 22(1): 142, 2021 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-34674700

RESUMO

BACKGROUND: The COVID-19 pandemic has had a significant impact on the health system worldwide. The organ and tissue donation and transplantation (OTDT) system is no exception and has had to face ethical challenges related to the pandemic, such as risks of infection and resource allocation. In this setting, many Canadian transplant programs halted their activities during the first wave of the pandemic. METHOD: To inform future ethical guidelines related to the COVID-19 pandemic or other public health emergencies of international concern, we conducted a literature review to summarize the ethical issues. RESULTS: This literature review identified three categories of ethical challenges. The first one describes the general ethical issues and challenges reported by OTDT organizations and transplantation programs, such as risks of COVID-19 transmission and infection to transplant recipients and healthcare professionals during the transplant process, risk of patient waitlist mortality or further resource strain where transplant procedures have been delayed or halted, and resource allocation. The second category describes ethical challenges related to informed consent in the context of uncertainty and virtual consent. Finally, the third category describes ethical issues related to organ allocation, such as social considerations in selecting transplant candidates. CONCLUSION: This literature review highlights the salient ethical issues related to OTDT during the current COVID-19 pandemic. As medical and scientific knowledge about COVID-19 increases, the uncertainties related to this disease will decrease and the associated ethical issues will continue to evolve.


Assuntos
COVID-19 , Transplante de Órgãos , Obtenção de Tecidos e Órgãos , Canadá , Humanos , Pandemias , SARS-CoV-2
18.
Ecol Lett ; 23(5): 870-880, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32216007

RESUMO

Demographic compensation arises when vital rates change in opposite directions across populations, buffering the variation in population growth rates, and is a mechanism often invoked to explain the stability of species geographic ranges. However, studies on demographic compensation have disregarded the effects of temporal variation in vital rates and their temporal correlations, despite theoretical evidence that stochastic dynamics can affect population persistence in temporally varying environments. We carried out a seven-year-long demographic study on the perennial plant Arabis alpina (L.) across six populations encompassing most of its elevational range. We discovered demographic compensation in the form of negative correlations between the means of plant vital rates, but also between their temporal coefficients of variation, correlations and elasticities. Even if their contribution to demographic compensation was small, this highlights a previously overlooked, but potentially important, role of stochastic processes in stabilising population dynamics at range margins.


Assuntos
Arabis , Plantas , Demografia , Dinâmica Populacional , Processos Estocásticos
19.
Glob Chang Biol ; 26(8): 4418-4435, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32358990

RESUMO

Several temperate tree species are expected to migrate northward and colonize boreal forests in response to climate change. Tree migrations could lead to transitions in forest types, but these could be influenced by several non-climatic factors, such as disturbances and soil conditions. We analysed over 10,000 forest inventory plots, sampled from 1970 to 2018 in meridional Québec, Canada, to identify what environmental conditions promote or prevent regional-scale forest transitions. We used a continuous-time multi-state Markov model to quantify the probabilities of transitions between forest states (temperate, boreal, mixed, pioneer) as a function of climate (mean temperature and climate moisture index during the growing season), soil conditions (pH and drainage) and disturbances (severity levels of natural disturbances and logging). We further investigate how different disturbance types and severities impact forests' short-term transient dynamics and long-term equilibrium using properties of Markov transition matrices. The most common transitions observed during the study period were from mixed to temperate states, as well as from pioneer to boreal forests. In our study, transitions were mainly driven by natural and anthropogenic disturbances and secondarily by climate, whereas soil characteristics exerted relatively minor constraints. While major disturbances only promoted transitions to the pioneer state, moderate disturbances increased the probability of transition from mixed to temperate states. Long-term projections of our model under the current environmental conditions indicate that moderate disturbances would promote a northward shift of the temperate forest. Moreover, disturbances reduced turnover and convergence time for all transitions, thereby accelerating forest dynamics. Contrary to our expectation, mixed to temperate transitions were not driven by temperate tree recruitment but by mortality and growth. Overall, our results suggest that moderate disturbances could catalyse rapid forest transitions and accelerate broad-scale biome shifts.


Assuntos
Mudança Climática , Florestas , Canadá , Ecossistema , Quebeque
20.
Clin Transplant ; 34(3): e13793, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31989699

RESUMO

BACKGROUND: Kidney transplantation is the best treatment for patients with end-stage renal disease. The decision to accept a kidney from a deceased donor can be a difficult one, especially when organs from high KDPI (>85%) donors are offered. This study aims to capture the perspectives of transplant nephrologists (TNs) on the decision-making process when an organ is offered. METHODS: Fifteen Canadian TNs took part in semi-structured interviews between December 2017 and April 2018. The interviews were digitally recorded, transcribed, and analyzed using the thematic analysis method. RESULTS: The decision to accept a deceased-donor kidney offer is a medical one for the participants. However, transplant candidates could be involved when the offered kidney is from a donor with a KDPI >85% or increased infectious risk donor. The TNs' past experience, comprehensive data on the donor, and education of the transplant candidate could facilitate the decision-making process. A decision aid could also facilitate the decision-making process, but different concerns should be addressed. CONCLUSION: Although accepting a deceased-donor organ offer is often viewed as an opportunity for shared decision-making, participants in this study viewed the decision to accept or refuse an offer as a medical decision with little room for patient participation.


Assuntos
Transplante de Rim , Obtenção de Tecidos e Órgãos , Canadá , Humanos , Rim , Nefrologistas , Doadores de Tecidos
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