Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Philos Trans R Soc Lond B Biol Sci ; 379(1902): 20230323, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38583467

RESUMO

Monitoring the extent to which invasive alien species (IAS) negatively impact the environment is crucial for understanding and mitigating biological invasions. Indeed, such information is vital for achieving Target 6 of the Kunming-Montreal Global Biodiversity Framework. However, to-date indicators for tracking the environmental impacts of IAS have been either lacking or insufficient. Capitalizing on advances in data availability and impact assessment protocols, we developed environmental impact indicators to track realized and potential impacts of IAS. We also developed an information status indicator to assess the adequacy of the data underlying the impact indicators. We used data on 75 naturalized amphibians from 82 countries to demonstrate the indicators at a global scale. The information status indicator shows variation in the reliability of the data and highlights areas where absence of impact should be interpreted with caution. Impact indicators show that growth in potential impacts are dominated by predatory species, while potential impacts from both predation and disease transmission are distributed worldwide. Using open access data, the indicators are reproducible and adaptable across scales and taxa and can be used to assess global trends and distributions of IAS, assisting authorities in prioritizing control efforts and identifying areas at risk of future invasions. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.


Assuntos
Biodiversidade , Espécies Introduzidas , Animais , Reprodutibilidade dos Testes , Anfíbios , Ecossistema
2.
Philos Trans R Soc Lond B Biol Sci ; 379(1902): 20230014, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38583473

RESUMO

In 2050, most areas of biodiversity significance will be heavily influenced by multiple drivers of environmental change. This includes overlap with the introduced ranges of many alien species that negatively impact biodiversity. With the decline in biodiversity and increase in all forms of global change, the need to envision the desired qualities of natural systems in the Anthropocene is growing, as is the need to actively maintain their natural values. Here, we draw on community ecology and invasion biology to (i) better understand trajectories of change in communities with a mix of native and alien populations, and (ii) to frame approaches to the stewardship of these mixed-species communities. We provide a set of premises and actions upon which a nature-positive future with biological invasions (NPF-BI) could be based, and a decision framework for dealing with uncertain species movements under climate change. A series of alternative management approaches become apparent when framed by scale-sensitive, spatially explicit, context relevant and risk-consequence considerations. Evidence of the properties of mixed-species communities together with predictive frameworks for the relative importance of the ecological processes at play provide actionable pathways to a NPF in which the reality of mixed-species communities are accommodated and managed. This article is part of the theme issue 'Ecological novelty and planetary stewardship: biodiversity dynamics in a transforming biosphere'.


Assuntos
Biodiversidade , Ecossistema , Espécies Introduzidas , Mudança Climática , Teoria da Decisão
3.
Curr Res Insect Sci ; 4: 100065, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37564301

RESUMO

Invasive alien insects are an important yet understudied component of the general threat that biological invasions pose to biodiversity. We quantified the breadth and level of this threat by performing environmental impact assessments using a modified version of the Environmental Impact Assessment for Alien Taxa (EICAT) framework. This represents the largest effort to date on quantify the environmental impacts of invasive alien insects. Using a relatively large and taxonomically representative set of insect species that have established non-native populations around the globe, we tested hypotheses on: (1) socioeconomic and (2) taxonomic biases, (3) relationship between range size and impact severity and (4) island susceptibility. Socioeconomic pests had marginally more environmental impact information than non-pests and, as expected, impact information was geographically and taxonomically skewed. Species with larger introduced ranges were more likely, on average, to have the most severe local environmental impacts (i.e. a global maximum impact severity of 'Major'). The island susceptibility hypothesis found no support, and both island and mainland systems experience similar numbers of high severity impacts. These results demonstrate the high variability, both within and across species, in the ways and extents to which invasive insects impact biodiversity, even within the highest profile invaders. However, the environmental impact knowledge base requires greater taxonomic and geographic coverage, so that hypotheses about invasion impact can be developed towards identifying generalities in the biogeography of invasion impacts.

4.
Sci Data ; 10(1): 200, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-37041141

RESUMO

Open data on biological invasions are particularly critical in regions that are co-governed and/or where multiple independent parties have responsibility for preventing and controlling invasive alien species. The Antarctic is one such region where, in spite of multiple examples of invasion policy and management success, open, centralised data are not yet available. This dataset provides current and comprehensive information available on the identity, localities, establishment, eradication status, dates of introduction, habitat, and evidence of impact of known introduced and invasive alien species for the terrestrial and freshwater Antarctic and Southern Ocean region. It includes 3066 records for 1204 taxa and 36 individual localities. The evidence indicates that close to half of these species are not having an invasive impact, and that ~ 13% of records are of species considered locally invasive. The data are provided using current biodiversity and invasive alien species data and terminology standards. They provide a baseline for updating and maintaining the foundational knowledge needed to halt the rapidly growing risk of biological invasion in the region.


Assuntos
Biodiversidade , Espécies Introduzidas , Regiões Antárticas , Ecossistema , Oceanos e Mares , Animais
6.
Trends Ecol Evol ; 32(5): 320-323, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28279488

RESUMO

Current evidence suggests that there is a positive relationship between biodiversity and ecosystem functioning, but few studies have addressed tropical ecosystems where the highest levels of biodiversity occur. We develop two hypotheses for the implications of generalizing from temperate studies to tropical ecosystems, and discuss the need for more tropical research.


Assuntos
Biodiversidade , Ecossistema , Clima Tropical
7.
Nature ; 492(7427): 52-3, 2012 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-23222605
8.
Macromol Biosci ; 10(8): 887-97, 2010 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-20376838

RESUMO

We have developed three-dimensional electrospun microfibrous meshes of a novel star branched three-arm poly(ε-caprolactone) (*PCL) as potential scaffolds for tissue engineering applications. The processing conditions required to obtain uniform fibers were optimized by studying their influence on fiber morphology and size. Polymer molecular weight and solution feed rate influenced both the mesh microstructure and the tensile properties of the developed mats. Electrospun samples were also tested for their mechanical properties in wet conditions, showing higher yield strength and strain in comparison to that observed in dry conditions. Cell culture experiments employing MC3T3-E1 osteoblast like cells showed good cell viability adhesion and collagen production on the *PCL scaffolds.


Assuntos
Poliésteres/química , Engenharia Tecidual , Células 3T3 , Animais , Materiais Biocompatíveis , Camundongos , Microscopia Eletrônica de Varredura
9.
J Mater Sci Mater Med ; 21(5): 1761-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20135202

RESUMO

Novel polymeric micro-nanostructure meshes as blood vessels substitute have been developed and investigated as a potential solution to the lack of functional synthetic small diameter vascular prosthesis. A commercial elastomeric polyurethane (Tecoflex EG-80A) and a natural biopolymer (gelatin) were successfully co-electrospun from different spinnerets on a rotating mandrel to obtain composite meshes benefiting from the mechanical characteristics of the polyurethane and the natural biopolymer cytocompatibility. Morphological analysis showed a uniform integration of micrometric (Tecoflex) and nanometric (gelatin) fibers. Exposure of the composite meshes to vapors of aqueous glutaraldehyde solution was carried out, to stabilize the gelatin fibers in an aqueous environment. Uniaxial tensile testing in wet conditions demonstrated that the analyzed Tecoflex-Gelatin specimens possessed higher extensibility and lower elastic modulus than conventional synthetic grafts, providing a closer matching to native vessels. Biological evaluation highlighted that, as compared with meshes spun from Tecoflex alone, the electrospun composite constructs enhanced endothelial cells adhesion and proliferation, both in terms of cell number and morphology. Results suggest that composite Tecoflex-Gelatin meshes could be promising alternatives to conventional vascular grafts, deserving of further studies on both their mechanical behaviour and smooth muscle cell compatibility.


Assuntos
Prótese Vascular , Gelatina/química , Bioprótese , Elasticidade , Células Endoteliais , Humanos , Miócitos de Músculo Liso , Poliuretanos , Próteses e Implantes
10.
Clin Pharmacokinet ; 43(8): 529-38, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15170367

RESUMO

OBJECTIVE: To characterise the pharmacokinetics of a long-acting formulation of fulvestrant following intramuscular administration of single and multiple doses. STUDY DESIGN: Pharmacokinetic investigations of single and multiple doses of fulvestrant were conducted within two global phase III efficacy studies that compared intramuscular fulvestrant with oral anastrozole in postmenopausal women with hormone-sensitive advanced breast cancer (study 0020, conducted in Europe, Australia and South Africa, and study 0021, conducted in North America). METHODS: Patients received once-monthly intramuscular injections of fulvestrant 250 mg (1 x 5 mL for < or =21 months in study 0020; 2 x 2.5 mL for < or =30 months in study 0021). Serial blood samples were collected for the first 28 days after the initial dose and immediately prior to all subsequent monthly doses. Plasma fulvestrant concentrations were determined by high-performance liquid chromatography-tandem mass spectrometry. PATIENTS: Twenty-six (study 0020) and 193 (study 0021) postmenopausal women, comprising the pharmacokinetic subgroups of the phase III efficacy trials, were studied. Patients had shown disease progression or recurrence following previous hormonal therapy for advanced disease or had relapsed after adjuvant endocrine therapy with a nonsteroidal antiestrogen. OUTCOME MEASURES AND RESULTS: For single-dose fulvestrant 250 mg, area under the concentration-time curve from time zero to 28 days (AUC(28)), maximum observed plasma concentration (C(max)), minimum observed plasma concentration at 28 days (C(min)) and time to maximum plasma concentration (t(max)) were determined. For multiple-dose fulvestrant 250 mg once monthly, steady-state trough concentrations (C(trough)) were determined. Plasma fulvestrant concentrations reached a peak at a median of 7 days (range 2-8 days) postdose, and declined biexponentially with a slower phase commencing approximately 2-3 weeks postdose. Intersubject variability in C(max) and AUC(28) was approximately 6-fold and 4-fold, respectively. Mean parameters for single-dose fulvestrant were: AUC(28), 148 microg. day/L; C(max), 8.2 microg/L; C(min), 2.6 microg/L; t(max), 7.0 days. Geometric mean C(trough) increased from 2.57 to 6.15 microg/L (study 0020) and from 2.38 to 6.52 microg/L (study 0021) over the first 6 months, reaching steady-state concentrations of approximately 6-7 microg/L (study 0020) or 9 microg/L (study 0021). Preliminary pharmacokinetic analysis, using a naive pooled data approach, suggests that observed single- and multiple-dose plasma profiles can be adequately described with a two-compartment kinetic model. Model-generated steady-state AUC(28) values were approximately 300 microg. day/L. CONCLUSIONS: The intramuscular formulation of fulvestrant displays predictable kinetics and approximately 2-fold accumulation on administration once monthly. At the proposed therapeutic dosage (250 mg once monthly), plasma fulvestrant concentrations are maintained within a narrow range throughout the administration interval, thus ensuring stable systemic drug exposure during long-term treatment.


Assuntos
Antineoplásicos Hormonais/farmacocinética , Neoplasias da Mama/tratamento farmacológico , Estradiol/análogos & derivados , Estradiol/farmacocinética , Antagonistas de Estrogênios/farmacocinética , Adulto , Idoso , Antineoplásicos Hormonais/sangue , Antineoplásicos Hormonais/uso terapêutico , Área Sob a Curva , Neoplasias da Mama/metabolismo , Neoplasias da Mama/radioterapia , Método Duplo-Cego , Estradiol/sangue , Estradiol/uso terapêutico , Antagonistas de Estrogênios/sangue , Antagonistas de Estrogênios/uso terapêutico , Feminino , Fulvestranto , Meia-Vida , Humanos , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Pós-Menopausa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...